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- partial fractions [ 01 / 29 / 1998 ] how do i express 3 / 1 - ( x ^ 3 ) in partial fractions? - pascal ' s triangle pattern [ 04 / 22 / 1999 ] what pattern does multiplying each entry by 1, 2, 3, 4, 5... in order, and adding the products yield? - perfect square : solving two equations [ 6 / 14 / 1996 ] x ^ 2 + 5 is a perfect square, and x ^ 2 - 5 is a perfect square. - perimeter equals area in a triangle [ 4 / 2 / 1996 ] when will the area and perimeter of a right triangle be numerically - picture frame, triangle measurements [ 5 / 20 / 1996 ] my teacher gave us ten questions to answer and i could do all except two : 1 ) a framed rectangular picture is 35cm long and 25cm wide... 2 ) the base of a triangle is 9cm more than the perpendicular height... - plus or minus sign [ 03 / 08 / 2002 ] what does this equation mean : y = + - k? the - sign is directly under the - point equidistant from 3 other points [ 04 / 11 / 1999 ] how do you find a point that is equidistant from three other points? - point on a line [ 03 / 23 / 2001 ] can you please tell me a formula to find if a point exists on a line? both are in x, y form. - polynomial brain - twisters [ 12 / 4 / 1995 ] i ' m stumped on some similar polynomial problems... - polynomial degrees and definition of a field [ 03 / 02 / 1998 ] the degree of polynomials added together, and definition of a field. - polynomial factoring rules [ 04 / 02 / 1997 ] how do i apply the polynomial factoring rules to t ^ 21 + 1 and 25y ^ 2 - 144 = - polynomial problem [ 3 / 11 / 1995 ] a remainder of 9 results when the polynomial p ( x ) is divided by x - 2, a remainder of - 3 when p ( x ) is divided by x + 2, and a remainder of 3 when divided by x - 1. find the remainder when p ( x ) is divided by ( x - 2 ) ( x + 2 ) ( x - - population and percentage [ 03 / 07 / 1999 ] given population data, find the number of women in two different years. - positive unit fractions [ 10 / 02 / 2002 ] find five
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- 2 ) ( x + 2 ) ( x - - population and percentage [ 03 / 07 / 1999 ] given population data, find the number of women in two different years. - positive unit fractions [ 10 / 02 / 2002 ] find five different positive unit fractions whose sum is 1. ( a unit fraction is a fraction whose numerator is 1. all denominators must also be natural numbers. ) - precedence of unary operators [ 09 / 01 / 99 ] the pemdas rule for order of operations ignores unary operators. can you explain the proper precedence for them, and give an example showing how not knowing the rule can cause an incorrect result? - preparing for an algebra test [ 11 / 1 / 1995 ] a 9th grade math student asks for help preparing for final exams. what is the difference between the terms : solve and simplify? how do you find the gradient in a graph? - prize money [ 09 / 04 / 1997 ] if first prize wins $ 1, 000 out of $ 6, 000 and twentieth prize wins $ 100, how much money do second through nineteenth place win? is this a - probability of a function having complex roots [ 05 / 11 / 2000 ] what is the probability that the function f ( x ) = x ^ 2 + px + q = 0 will have complex roots when p and q lie between 0 and 1?... when p and q lie between 0 and 5?... when p and q are greater than 0?
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hydrocele operation : aka hydroceles, hydrocele sac, swollen testicle, hydrocelectomy what is it? hydrocele operations or hydrocele surgery is to release fluid that forms in a sac within the scrotum. typically hydroceles develop when the testicle passes into the scrotum but the passage through which this occur fails to close properly. fluid can accumulate in this passage from the abdomen, and then enters the scrotum causing it to swell. this can cause one or both sides of the scrotum to swell and the testicle itself to swell or become damage and inflamed. fluid can also block the tube where sperm typically flow from. hydroceles are more common in newborn boys but are not exclusive to newborn boys. to diagnose a hydrocele typically a doctor will look for swelling in the scrotum caused primarily by fluid build up or will look for something solid like a fluid - filled sac in the scrotum. typically fluid is removed from the hydrocele sac during a procedure called a hydrocelectomy. for the most part this is a straightforward and uncomplicated procedure that may produce a moderate amount of soreness for a few days following the procedure. the long - term benefits far outweigh any short - term soreness. many times the patient is a young patient under the age of 10 or in many cases a newborn baby that is born with a hydrocele defect. usually a surgery takes placed under general anesthesia. a surgeon will make a small incision in the scrotum that will allow fluid to be drained from the scrotum and then seal the passage from the scrotum to the abdomen. usually the incision is then closed with stitches that will dissolve on their own so they do not have to be removed later. alternatives to surgery there are no known alternatives to this surgery currently. before the operation prior to the operation the doctor will confirm a fluid filled sac exists by placing a light to the scrotum which will light up the testicles, veins in the scrotum and the fluid filled sac which will appear clear to the light. a doctor will also perform a comprehensive medical history and check any medications the patient is currently taking. patients are advised not to eat or drink anything up to 12 hours before the procedure because it is performed under general anesthesia. after the operation - at home once the operation is complete the patient will recover usually for a few hours in a day bed. the procedure is usually
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to eat or drink anything up to 12 hours before the procedure because it is performed under general anesthesia. after the operation - at home once the operation is complete the patient will recover usually for a few hours in a day bed. the procedure is usually performed on an outpatient basis meaning the patient can usually go home on the same day. most of the time it is best to wear looser fitting close that will prevent irritation and discomfort on leaving. there are some risks associated with this procedure as there are with any procedure including a small risk of infection. other risks including the risk of bleeding during or after the procedure, and a risk of a blood clot forming in the area of the procedure. the doctor may accidentally damage the scrotum or the tissues surrounding this area too. anytime a patient undergoes general anesthesia there are risks associated with this too including a risk of pneumonia following surgery. the nurse or doctor will encourage the patient to take deep breaths to clear the lungs following surgery. many people especially younger children undergoing this operation may report feeling nauseous or dizzy following the procedure, a side effect largely associated with the general anesthesia. these complications are usually temporary however and resolve within a couple of days of treatment. a hydrocele procedure is generally performed to relieve fluid build up around the testicle or within the scrotum. this procedure is relatively simple with few complications. the primary risks include a risk of infection and risk of rupture or nicks to nearby tissues or structures. if you work with a competent health professional you reduce your odds of complications. because these surgeries are often performed on younger individuals it pays to ask someone if they have experience working on youths or pediatric patients. you may need to pay a small amount extra to work with someone that specializes in pediatrics or even geriatrics if you are over 50 or 60 and have a fluid - filled sac in the scrotum that you require surgery for. regardless of where you go or who you see make sure they practice safe hygiene practices to ensure your safety and wellness. estimated costs for hydrocele operation the cost of surgery varies widely and may depend partly on the patient ’ s age and overall health and wellness. patients that do not require extensive health accommodations or hospital stays are likely to have to pay the least in adjunctive healthcare therapy. that said you should always be prepared to foot the bill for extra expenses including any complications that may rise from treatment. health insurance may offset some of these costs. keep in mind there may be separate fees associated with anesthesia.
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welcome to medlibrary. org. for best results, we recommend beginning with the navigation links at the top of the page, which can guide you through our collection of over 14, 000 medication labels and package inserts. for additional information on other topics which are not covered by our database of medications, just enter your topic in the search box below : chromatography [ | krəʊmə | tɒgrəfi ] ( from greek χρωμα chroma " color " and γραφειν graphein " to write " ) is the collective term for a set of laboratory techniques for the separation of mixtures. the mixture is dissolved in a fluid called the mobile phase, which carries it through a structure holding another material called the stationary phase. the various constituents of the mixture travel at different speeds, causing them to separate. the separation is based on differential partitioning between the mobile and stationary phases. subtle differences in a compound ' s partition coefficient result in differential retention on the stationary phase and thus changing the separation. chromatography may be preparative or analytical. the purpose of preparative chromatography is to separate the components of a mixture for more advanced use ( and is thus a form of purification ). analytical chromatography is done normally with smaller amounts of material and is for measuring the relative proportions of analytes in a mixture. the two are not mutually exclusive. chromatography, literally " color writing ", was first employed by russian - italian scientist mikhail tsvet in 1900. he continued to work with chromatography in the first decade of the 20th century, primarily for the separation of plant pigments such as chlorophyll, carotenes, and xanthophylls. since these components have different colors ( green, orange, and yellow, respectively ) they gave the technique its name. new types of chromatography developed during the 1930s and 1940s made the technique useful for many separation processes. chromatography technique developed substantially as a result of the work of archer john porter martin and richard laurence millington synge during the 1940s and 1950s. they established the principles and basic techniques of partition chromatography, and their work encouraged the rapid development of several chromatographic methods : paper chromatography, gas chromatography, and what would become known as high performance liquid chromatography. since then, the technology has advanced rapidly. researchers found that the main principles
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development of several chromatographic methods : paper chromatography, gas chromatography, and what would become known as high performance liquid chromatography. since then, the technology has advanced rapidly. researchers found that the main principles of tsvet ' s chromatography could be applied in many different ways, resulting in the different varieties of chromatography described below. advances are continually improving the technical performance of chromatography, allowing the separation of increasingly similar molecules. chromatography terms - the analyte is the substance to be separated during chromatography. - analytical chromatography is used to determine the existence and possibly also the concentration of analyte ( s ) in a sample. - a bonded phase is a stationary phase that is covalently bonded to the support particles or to the inside wall of the column tubing. - a chromatogram is the visual output of the chromatograph. in the case of an optimal separation, different peaks or patterns on the chromatogram correspond to different components of the separated mixture. - plotted on the x - axis is the retention time and plotted on the y - axis a signal ( for example obtained by a spectrophotometer, mass spectrometer or a variety of other detectors ) corresponding to the response created by the analytes exiting the system. in the case of an optimal system the signal is proportional to the concentration of the specific analyte separated. - a chromatograph is equipment that enables a sophisticated separation e. g. gas chromatographic or liquid chromatographic separation. - chromatography is a physical method of separation that distributes components to separate between two phases, one stationary ( stationary phase ), while the other ( the mobile phase ) moves in a definite direction. - the eluate is the mobile phase leaving the column. - the eluent is the solvent that carries the analyte. - an eluotropic series is a list of solvents ranked according to their eluting power. - an immobilized phase is a stationary phase that is immobilized on the support particles, or on the inner wall of the column tubing. - the mobile phase is the phase that moves in a definite direction. it may be a liquid ( lc and capillary electrochromatography ( cec ) ), a gas ( gc ), or a supercritical fluid ( supercritical - fluid chromatography,
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a definite direction. it may be a liquid ( lc and capillary electrochromatography ( cec ) ), a gas ( gc ), or a supercritical fluid ( supercritical - fluid chromatography, sfc ). the mobile phase consists of the sample being separated / analyzed and the solvent that moves the sample through the column. in the case of hplc the mobile phase consists of a non - polar solvent ( s ) such as hexane in normal phase or polar solvents in reverse phase chromotagraphy and the sample being separated. the mobile phase moves through the chromatography column ( the stationary phase ) where the sample interacts with the stationary phase and is separated. - preparative chromatography is used to purify sufficient quantities of a substance for further use, rather than analysis. - the retention time is the characteristic time it takes for a particular analyte to pass through the system ( from the column inlet to the detector ) under set conditions. see also : kovats ' retention index - the sample is the matter analyzed in chromatography. it may consist of a single component or it may be a mixture of components. when the sample is treated in the course of an analysis, the phase or the phases containing the analytes of interest is / are referred to as the sample whereas everything out of interest separated from the sample before or in the course of the analysis is referred to as waste. - the solute refers to the sample components in partition chromatography. - the solvent refers to any substance capable of solubilizing another substance, and especially the liquid mobile phase in liquid chromatography. - the stationary phase is the substance fixed in place for the chromatography procedure. examples include the silica layer in thin layer chromatography chromatography is based on the concept of partition coefficient. any solute partitions between two immiscible solvents. when we make one solvent immobile ( by adsorption on a solid support matrix ) and another mobile it results in most common applications of chromatography. if matrix support is polar ( e. g. paper, silica etc. ) it is forward phase chromatography, and if it is non polar ( c - 18 ) it is reverse phase. techniques by chromatographic bed shape column chromatography column chromatography is a separation technique in which the stationary bed is within a tube.
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mixture travel different distances according to how strongly they interact with the stationary phase as compared to the mobile phase. the specific retention factor ( rf ) of each chemical can be used to aid in the identification of an unknown substance. paper chromatography paper chromatography is a technique that involves placing a small dot or line of sample solution onto a strip of chromatography paper. the paper is placed in a jar containing a shallow layer of solvent and sealed. as the solvent rises through the paper, it meets the sample mixture, which starts to travel up the paper with the solvent. this paper is made of cellulose, a polar substance, and the compounds within the mixture travel farther if they are non - polar. more polar substances bond with the cellulose paper more quickly, and therefore do not travel as far. thin layer chromatography thin layer chromatography ( tlc ) is a widely employed laboratory technique and is similar to paper chromatography. however, instead of using a stationary phase of paper, it involves a stationary phase of a thin layer of adsorbent like silica gel, alumina, or cellulose on a flat, inert substrate. compared to paper, it has the advantage of faster runs, better separations, and the choice between different adsorbents. for even better resolution and to allow for quantification, high - performance tlc can be used. displacement chromatography the basic principle of displacement chromatography is : a molecule with a high affinity for the chromatography matrix ( the displacer ) competes effectively for binding sites, and thus displace all molecules with lesser affinities. there are distinct differences between displacement and elution chromatography. in elution mode, substances typically emerge from a column in narrow, gaussian peaks. wide separation of peaks, preferably to baseline, is desired for maximum purification. the speed at which any component of a mixture travels down the column in elution mode depends on many factors. but for two substances to travel at different speeds, and thereby be resolved, there must be substantial differences in some interaction between the biomolecules and the chromatography matrix. operating parameters are adjusted to maximize the effect of this difference. in many cases, baseline separation of the peaks can be achieved only with gradient elution and low column loadings. thus, two drawbacks to elution mode chromatography, especially at the preparative
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maximize the effect of this difference. in many cases, baseline separation of the peaks can be achieved only with gradient elution and low column loadings. thus, two drawbacks to elution mode chromatography, especially at the preparative scale, are operational complexity, due to gradient solvent pumping, and low throughput, due to low column loadings. displacement chromatography has advantages over elution chromatography in that components are resolved into consecutive zones of pure substances rather than “ peaks ”. because the process takes advantage of the nonlinearity of the isotherms, a larger column feed can be separated on a given column with the purified components recovered at significantly higher concentrations. techniques by physical state of mobile phase gas chromatography gas chromatography ( gc ), also sometimes known as gas - liquid chromatography, ( glc ), is a separation technique in which the mobile phase is a gas. gas chromatography is always carried out in a column, which is typically " packed " or " capillary " ( see below ). gas chromatography is based on a partition equilibrium of analyte between a solid stationary phase ( often a liquid silicone - based material ) and a mobile gas ( most often helium ). the stationary phase is adhered to the inside of a small - diameter glass tube ( a capillary column ) or a solid matrix inside a larger metal tube ( a packed column ). it is widely used in analytical chemistry ; though the high temperatures used in gc make it unsuitable for high molecular weight biopolymers or proteins ( heat denatures them ), frequently encountered in biochemistry, it is well suited for use in the petrochemical, environmental monitoring and remediation, and industrial chemical fields. it is also used extensively in chemistry research. liquid chromatography liquid chromatography ( lc ) is a separation technique in which the mobile phase is a liquid. liquid chromatography can be carried out either in a column or a plane. present day liquid chromatography that generally utilizes very small packing particles and a relatively high pressure is referred to as high performance liquid chromatography ( hplc ). in hplc the sample is forced by a liquid at high pressure ( the mobile phase ) through a column that is packed with a stationary phase composed of irregularly or spherically shaped particles, a porous monolithic layer, or a porous membrane. hplc is historically divided into two
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a liquid at high pressure ( the mobile phase ) through a column that is packed with a stationary phase composed of irregularly or spherically shaped particles, a porous monolithic layer, or a porous membrane. hplc is historically divided into two different sub - classes based on the polarity of the mobile and stationary phases. methods in which the stationary phase is more polar than the mobile phase ( e. g., toluene as the mobile phase, silica as the stationary phase ) are termed normal phase liquid chromatography ( nplc ) and the opposite ( e. g., water - methanol mixture as the mobile phase and c18 = octadecylsilyl as the stationary phase ) is termed reversed phase liquid chromatography ( rplc ). ironically the " normal phase " has fewer applications and rplc is therefore used considerably more. specific techniques under this broad heading are listed below. affinity chromatography affinity chromatography is based on selective non - covalent interaction between an analyte and specific molecules. it is very specific, but not very robust. it is often used in biochemistry in the purification of proteins bound to tags. these fusion proteins are labeled with compounds such as his - tags, biotin or antigens, which bind to the stationary phase specifically. after purification, some of these tags are usually removed and the pure protein is obtained. affinity chromatography often utilizes a biomolecule ' s affinity for a metal ( zn, cu, fe, etc. ). columns are often manually prepared. traditional affinity columns are used as a preparative step to flush out unwanted biomolecules. however, hplc techniques exist that do utilize affinity chromatogaphy properties. immobilized metal affinity chromatography ( imac ) is useful to separate aforementioned molecules based on the relative affinity for the metal ( i. e. dionex imac ). often these columns can be loaded with different metals to create a column with a targeted affinity. supercritical fluid chromatography supercritical fluid chromatography is a separation technique in which the mobile phase is a fluid above and relatively close to its critical temperature and pressure. techniques by separation mechanism ion exchange chromatography ion exchange chromatography ( usually referred to as ion chromatography ) uses an ion exchange mechanism to separate analytes based on their respective charges. it is usually performed in columns but can also be useful in
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exchange chromatography ion exchange chromatography ( usually referred to as ion chromatography ) uses an ion exchange mechanism to separate analytes based on their respective charges. it is usually performed in columns but can also be useful in planar mode. ion exchange chromatography uses a charged stationary phase to separate charged compounds including anions, cations, amino acids, peptides, and proteins. in conventional methods the stationary phase is an ion exchange resin that carries charged functional groups that interact with oppositely charged groups of the compound to retain. ion exchange chromatography is commonly used to purify proteins using fplc. size - exclusion chromatography size - exclusion chromatography ( sec ) is also known as gel permeation chromatography ( gpc ) or gel filtration chromatography and separates molecules according to their size ( or more accurately according to their hydrodynamic diameter or hydrodynamic volume ). smaller molecules are able to enter the pores of the media and, therefore, molecules are trapped and removed from the flow of the mobile phase. the average residence time in the pores depends upon the effective size of the analyte molecules. however, molecules that are larger than the average pore size of the packing are excluded and thus suffer essentially no retention ; such species are the first to be eluted. it is generally a low - resolution chromatography technique and thus it is often reserved for the final, " polishing " step of a purification. it is also useful for determining the tertiary structure and quaternary structure of purified proteins, especially since it can be carried out under native solution conditions. expanded bed adsorption ( eba ) chromatographic separation expanded bed adsorption ( eba ) chromatographic separation captures a target protein from a crude feed stream when it passes through a chromatography column system containing adsorbent beads. with this technique the crude feedstock can be treated directly in the chromatographic column, avoiding the traditional clarification and pre - treatment steps. eba chromatographic separation is highly scalable, from laboratory - based 1 cm diameter columns to large production columns up to 2 meter in diameter. these columns can typically handle feed stock throughput of more than 1, 000, 000 liter per day with a production capacity of 1000 mt protein per year. special techniques reversed - phase chromatography reversed - phase chromatography ( r
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. these columns can typically handle feed stock throughput of more than 1, 000, 000 liter per day with a production capacity of 1000 mt protein per year. special techniques reversed - phase chromatography reversed - phase chromatography ( rpc ) is any liquid chromatography procedure in which the mobile phase is significantly more polar than the stationary phase. it is so named because in normal - phase liquid chromatography, the mobile phase is significantly less polar than the stationary phase. hydrophobic molecules in the mobile phase tend to adsorb to the relatively hydrophobic stationary phase. hydrophilic molecules in the mobile phase will tend to elute first. two - dimensional chromatography in some cases, the chemistry within a given column can be insufficient to separate some analytes. it is possible to direct a series of unresolved peaks onto a second column with different physico - chemical ( chemical classification ) properties. since the mechanism of retention on this new solid support is different from the first dimensional separation, it can be possible to separate compounds that are indistinguishable by one - dimensional chromatography. the sample is spotted at one corner of a square plate, developed, air - dried, then rotated by 90° and usually redeveloped in a second solvent system. simulated moving - bed chromatography pyrolysis gas chromatography pyrolysis gas chromatography mass spectrometry is a method of chemical analysis in which the sample is heated to decomposition to produce smaller molecules that are separated by gas chromatography and detected using mass spectrometry. pyrolysis is the thermal decomposition of materials in an inert atmosphere or a vacuum. the sample is put into direct contact with a platinum wire, or placed in a quartz sample tube, and rapidly heated to 600 – 1000 °c. depending on the application even higher temperatures are used. three different heating techniques are used in actual pyrolyzers : isothermal furnace, inductive heating ( curie point filament ), and resistive heating using platinum filaments. large molecules cleave at their weakest points and produce smaller, more volatile fragments. these fragments can be separated by gas chromatography. pyrolysis gc chromatograms are typically complex because a wide range of different decomposition products is formed. the data can either be used as fingerprint to prove material identity or the gc / ms data is used to identify individual
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pyrolysis gc chromatograms are typically complex because a wide range of different decomposition products is formed. the data can either be used as fingerprint to prove material identity or the gc / ms data is used to identify individual fragments to obtain structural information. to increase the volatility of polar fragments, various methylating reagents can be added to a sample before pyrolysis. besides the usage of dedicated pyrolyzers, pyrolysis gc of solid and liquid samples can be performed directly inside programmable temperature vaporizer ( ptv ) injectors that provide quick heating ( up to 30 °c / s ) and high maximum temperatures of 600 – 650 °c. this is sufficient for some pyrolysis applications. the main advantage is that no dedicated instrument has to be purchased and pyrolysis can be performed as part of routine gc analysis. in this case quartz gc inlet liners have to be used. quantitative data can be acquired, and good results of derivatization inside the ptv injector are published as well. fast protein liquid chromatography fast protein liquid chromatography ( fplc ) is a term applied to several chromatography techniques which are used to purify proteins. many of these techniques are identical to those carried out under high performance liquid chromatography, however use of fplc techniques are typically for preparing large scale batches of a purified product. countercurrent chromatography countercurrent chromatography ( ccc ) is a type of liquid - liquid chromatography, where both the stationary and mobile phases are liquids. the operating principle of ccc equipment requires a column consisting of an open tube coiled around a bobbin. the bobbin is rotated in a double - axis gyratory motion ( a cardioid ), which causes a variable gravity ( g ) field to act on the column during each rotation. this motion causes the column to see one partitioning step per revolution and components of the sample separate in the column due to their partitioning coefficient between the two immiscible liquid phases used. there are many types of ccc available today. these include hsccc ( high speed ccc ) and hpccc ( high performance ccc ). hpccc is the latest and best performing version of the instrumentation available currently. chiral chromatography chiral chromatography involves the separation of stereoisomers.
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ccc ) and hpccc ( high performance ccc ). hpccc is the latest and best performing version of the instrumentation available currently. chiral chromatography chiral chromatography involves the separation of stereoisomers. in the case of enantiomers, these have no chemical or physical differences apart from being three - dimensional mirror images. conventional chromatography or other separation processes are incapable of separating them. to enable chiral separations to take place, either the mobile phase or the stationary phase must themselves be made chiral, giving differing affinities between the analytes. chiral chromatography hplc columns ( with a chiral stationary phase ) in both normal and reversed phase are commercially available. see also - iupac nomenclature for chromatography iupac recommendations 1993, pure & appl. chem., vol. 65, no. 4, pp. 819 – 872, 1993. - still, w. c. ; kahn, m. ; mitra, a. j. org. chem. 1978, 43 ( 14 ), 2923 – 2925. doi : 10. 1021 / jo00408a041 - laurence m. harwood, christopher j. moody ( 13 june 1989 ). experimental organic chemistry : principles and practice ( illustrated ed. ). wileyblackwell. pp. 180 – 185. isbn 978 - 0 - 632 - 02017 - 1 [ amazon - us | amazon - uk ]. - christian b. anfinsen, john tileston edsall, frederic middlebrook richards advances in protein chemistry. science 1976, 6 - 7. - displacement chromatography 101. sachem, inc. austin, tx 78737 - pascal bailon, george k. ehrlich, wen - jian fung and wolfgang berthold, an overview of affinity chromatography, humana press, 2000. isbn 978 - 0 - 89603 - 694 - 9 [ amazon - us | amazon - uk ], isbn 978 - 1 - 60327 - 261 - 2 [ amazon - us | amazon - uk ]. - iupac nomenclature for chromatography - chromedia on line database and community for chromatography practitioners ( paid subscription required ) - library 4 science : chrom - ed series - overlapping peaks program – learning by simulations - chromatography videos – mit ocw – digital lab techniques manual - chromato
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other proposed treatments it is one of the cardinal principles of natural medicine that treatment should aim not only to treat illness but also to enhance wellness. according to this ideal, a proper course of treatment should improve your sense of general well - being, enhance your immunity to illness, raise your physical stamina, and increase mental alertness, as well as resolve the specific condition you took it for. unfortunately, while there can be little doubt that this is a laudable goal, it is easier to laud it than to achieve it. conventional medicine tends to focus on treating diseases rather than increasing wellness, not as a matter of philosophical principle, but because it is easier to accomplish. probably the strongest force affecting wellness is genetics. beyond that, common sense steps endorsed by all physicians include increasing exercise, reducing stress, improving diet, getting enough sleep, and living a life of moderation without bad habits, such as smoking or overeating. beyond this, however, it is difficult to make strong affirmations, and the optimum forms of diet and exercise and other aspects of lifestyle remain unclear. in fact, they may always remain unclear, as it is impossible to perform double - blind, placebo - controlled studies on most lifestyle habits. ( for information on why such studies are irreplaceable see " why does this database depend on double - blind studies? " ) principal proposed natural treatments in order to function at our best, we need good nutrition. however, the modern diet often fails to provide people with sufficient amounts of all the necessary nutrients. for this reason, use of a multivitamin / multimineral supplement might be expected to enhance overall health and well - being, and preliminary double - blind trials generally support this view. for more information, see the article on general nutritional support. the herb panax ginseng has an ancient reputation as a healthful “ tonic. ” according to a more modern concept developed in the former ussr, ginseng functions as an “ adaptogen. ” this term is defined as follows : an adaptogen helps the body adapt to stresses of various kinds, whether heat, cold, exertion, trauma, sleep deprivation, toxic exposure, radiation, infection, or psychologic stress. in addition, an adaptogen causes no side effects, is effective in treating a wide variety of illnesses, and helps return an organism toward balance no matter what may have gone wrong. from a modern scientific perspective, it is not truly clear that such things as adaptogens actually exist. however, there is some
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subdomain_quantum_optics
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HuggingFaceFW/fineweb-edu
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<urn:uuid:39bb84af-9a63-43d7-b933-3bee4727c361>
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2025-12-17T20:53:59.412818
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binge eating disorder " signs and symptoms " to date, there has been some degree of confusion as to what exactly the term " binge eating " really means. although the professional community still has yet to define [ or quantify ] what constitutes a binge - eating episode, it ' s reasonable to assume the signs and symptoms listed below are a good barometer of what is characteristic binge eating. in many respects, binge eating disorder [ bed ] is similar to bulimia without the compensatory behaviors. in addition, the term compulsive overeating may be " interchangeable " with bed - although some compulsive overeaters have a pattern of eating constantly [ " grazing " ] rather than experiencing episodes of binge eating per se. signs and symptoms binge eating / compulsive overeating [ coe ] - preoccupation with food. - rapid consumption of food in significant excess of nutritional need - sneaking or hoarding food - even immediately after meals. - feeling ashamed or fearful when confronted about the problem. - excessive concern about weight and body shape. - sense of " losing control " during binge episode. - feeling lonely, depressed, worried, self preoccupied - spending a great deal of time alone / social isolation - alternating between binge eating and " dieting " treating bed at milestones as with many other eating disorders, the characteristics of a binge eating disorder appear to mimic [ inherent among ] other dependencies or addictions - whether to a substance or set of behaviors. in fact, the most recent committee of the american psychiatric association " officially " included bed as a bona fide disorder [ disease ]. the link below lists the criteria for " dependency " and requires only three of the several criteria " fit " for a diagnosis of dependency [ aka addiction ] to be considered. the program offered at milestones is comprised of two primary components, making the treatment experience unique in comparison to other programs. the first is the setting - utilizing apartment - style residences affording residential participants an opportunity to experience treatment in a " real world " environment. participants grocery shop with our dietitian within the community, learn to prepare their own meals per the prescribed [ meal ] food / meal plan they have formulated with the dietitian, attend a full schedule of groups and individual therapies at our clinical campus [ near the residential complex ], attend local community support groups in the evenings, and visit with our physicians and clinical staff regularly throughout their stay. in effect, the experience
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subdomain_quantum_optics
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HuggingFaceFW/fineweb-edu
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<urn:uuid:26e14fdc-9941-4f09-a1d7-7e7a78349e4e>
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2025-12-17T20:53:59.417783
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, attend a full schedule of groups and individual therapies at our clinical campus [ near the residential complex ], attend local community support groups in the evenings, and visit with our physicians and clinical staff regularly throughout their stay. in effect, the experience is one of providing a supportive and structured setting without the restrictive elements of a " hospital " or institutional facility. a key element in providing the support necessary to begin recovery is remaining in the company of other participants during the initial phase of the treatment. this provides both a form of supervision and a deterrent from the behavior often associated with binge eating : namely eating in isolation or alone. secondly, milestones approaches treatment from a more " holistic " perspective. doing so is best described by the acronym " serf " - spirituality, exercise, rest, and food plan. spirituality need not equate with any religious or spiritual beliefs imposed on or by anyone. in fact, spirituality at milestones simply is left up to the individual to cultivate with his or her own working definition. for most, it is a belief in a " higher power " and still for others it may be a return to some of their original religious beliefs. for everyone, it is an individual journey. exercise is individualized and represents collaboration between the resident and clinical team. it is meant to be in the service of restoring and maintaining a healthy body rather than an " intensive " means of controlling body weight. rest is simply about finding the correct balance in recovery between work and play and narrowing the gap between an " all or none ", " feast or famine " approach to daily living. the food plan suggested by milestones is a blend of structured eating and a combination of healthy, whole foods that are bought and prepared by participants with the guidance and supervision of our dietitian and ancillary staff. in brief participants select their own preferences within the guidelines of their individual food plans. the guidelines require participants to abstain from " junk foods " and eliminate most highly processed [ sugar and flour laden ] food products as well as weigh and measure portions per their food plan while in residence. it is important to mention most participants who seek treatment for most eating disorders may have a tendency to focus on " trading in the binging and / or " purging " to become better at restricting or " losing weight " and as such, it is important to understand the predisposition to replace one form of an eating disorder for another. acknowledging this is helpful to maintaining the prescribed treatment plan both during and after the residential treatment experience.
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subdomain_quantum_field_theory
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HuggingFaceFW/fineweb-edu
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2025-12-17T20:53:59.418697
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a reference resource life before the presidency herbert clark hoover was born on august 10, 1874. for the first nine years of his life, he lived in the small town of west branch, iowa, the place of his birth. his quaker father, jessie clark hoover, a blacksmith and farm equipment salesman, suffered a heart attack and died when herbert was six years old. three years later, the boy ' s mother, huldah minthorn hoover, developed pneumonia and also passed away, orphaning herbert, his older brother theodore, and little sister mary. passed around among relatives for a few years, hoover ended up with his uncle, dr. john minthorn, who lived in oregon. the young hoover was shy, sensitive, introverted, and somewhat suspicious, characteristics that developed, at least in part, in reaction to the loss of his parents at such a young age. he attended friends pacific academy in newberg, oregon, earning average to failing grades in all subjects except math. determined, nevertheless, to go to the newly established stanford university in palo alto, california, hoover studied hard and barely passed the university ' s entrance exam. he went on to major in geology and participated in a host of extracurricular activities, serving as class treasurer of the junior and senior student bodies and managing the school baseball and football teams. to pay his tuition, hoover worked as a clerk in the registration office and showed considerable entrepreneurial skill by starting a student laundry service. career and monetary success during the summers, hoover worked as a student assistant on geological survey teams in arkansas, california, and nevada. after his graduation in 1895, he looked hard to find work as a surveyor but ended up laboring seventy hours a week at a gold mine near nevada city, california, pushing ore carts. luck came his way with an office job in san francisco, putting him in touch with a firm in need of an engineer to inspect and evaluate mines for potential purchase. hoover then moved to australia in 1897 and china in 1899, where he worked as a mining engineer until 1902. a string of similar jobs took him all over the world and helped hoover become a giant in his field. he opened his own mining consulting business in 1908 ; by 1914, hoover was financially secure, earning his wealth from high - salaried positions, his ownership of profitable burmese silver mines, and royalties from writing the leading textbook on mining engineering. his wife, lou henry hoover, traveled with him everywhere he went. herbert and lou met in college, where she was the sole female geology major at
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subdomain_quantum_mechanics
| 0.417389
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HuggingFaceFW/fineweb-edu
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<urn:uuid:494a31b6-e8c3-42b2-bcba-79889bce2dfd>
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2025-12-17T20:53:59.426212
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, his ownership of profitable burmese silver mines, and royalties from writing the leading textbook on mining engineering. his wife, lou henry hoover, traveled with him everywhere he went. herbert and lou met in college, where she was the sole female geology major at stanford. he proposed to her by cable from australia as he prepared to move to china ; she accepted by return wire and they married in 1899. the couple was in china during the boxer rebellion of 1900, a time when lou helped nurse wounded western diplomats and soldiers while herbert assisted in the fighting to defend tianjin, a city near the uprising. by the time the couple returned home to america in 1917, lou had learned to shoot a gun and had mastered eight languages. over the course of his career as a mining engineer and businessman, hoover ' s intellect and understanding of the world matured considerably. hoover was raised a quaker and although he rarely went to meeting as an adult, he internalized that faith ' s belief in the power of the individual, the importance of freedom, and the value of " conscientious work " and charity. hoover also applied the ethos of engineering to the world in general, believing that scientific expertise, when employed thoughtfully and properly, led to human progress. hoover worked comfortably in a capitalist economy but believed in labor ' s right to organize and hoped that cooperation ( between labor and management and among competitors ) might come to characterize economic relations. during these years, hoover repeatedly made known to friends his desire for public service. politically, hoover identified with the progressive wing of the republican party, supporting theodore roosevelt ' s third - party bid in 1912. world war i brought hoover to prominence in american politics and thrust him into the international spotlight. in london when the war broke out, he was asked by the u. s. consul to organize the evacuation of 120, 000 americans trapped in europe. germany ' s devastating invasion of belgium led hoover to pool his money with several wealthy friends to organize the committee for the relief of belgium. working without direct government support, hoover raised millions of dollars for food and medicine to help desperate belgians. in 1917, after the united states entered the war, president woodrow wilson asked hoover to run the u. s. food administration. hoover performed quite admirably, guiding the effort to conserve resources and supplies needed for the war and to feed america ' s european allies. hoover even became a household name during the war ; nearly all americans knew that the verb " to hooverize " meant the rationing of household materials. after the armistice treaty
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subdomain_quantum_entanglement
| 0.493032
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:494a31b6-e8c3-42b2-bcba-79889bce2dfd>
| 1
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2025-12-17T20:53:59.428355
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resources and supplies needed for the war and to feed america ' s european allies. hoover even became a household name during the war ; nearly all americans knew that the verb " to hooverize " meant the rationing of household materials. after the armistice treaty was signed in november 1918, officially ending world war i, wilson appointed hoover to head the european relief and rehabilitation administration. in this capacity, hoover channeled 34 million tons of american food, clothing, and supplies to war - torn europe, aiding people in twenty nations. his service during world war i made hoover one of the few republicans trusted by wilson. because of hoover ' s knowledge of world affairs, wilson relied him at the versailles peace conference and as director of the president ' s supreme economic council in 1918. the following year, hoover founded the hoover library on war, revolution, and peace at stanford university as an archive for the records of world war i. this privately endowed organization later became the hoover institution, devoted to the study of peace and war. no isolationist, hoover supported american participation in the league of nations. he believed, though, that wilson ' s stubborn idealism led congress to reject american participation in the league. secretary of commerce in 1920, hoover emerged as a contender for the republican presidential nomination. his run was blocked, however, by fellow a californian, senator hiram johnson, who objected to hoover ' s support for the league. republican warren harding won the white house in 1920 and appointed hoover as his secretary of commerce, a position that hoover retained under harding ' s successor, president calvin coolidge. under hoover ' s leadership, the department of commerce became as influential and important a government agency as the departments of state and treasury. hoover encouraged research into measures designed to counteract harmful business cycles. he supported government regulation of new industries like aviation and radio. he brought together more than one hundred different industries and convinced them to adopt standardized tools, hardware, building materials, and automobile parts. finally, he aggressively pursued international trade opportunities for american business. to win these reforms, hoover strengthened existing agencies in the commerce department, like the bureau of foreign and domestic commerce, or simply established new ones, like the bureau of standards, for the standardization project. he also formed commissions that brought together government officials, experts, and leaders of the relevant economic sectors to work towards reform. the initiatives hoover supported as commerce secretary — and the ways in which he pursued them — reveal his thinking about contemporary life in the united states and about the federal government ' s role in american society. hoover hoped to
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subdomain_quantum_mechanics
| 0.45381
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HuggingFaceFW/fineweb-edu
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<urn:uuid:494a31b6-e8c3-42b2-bcba-79889bce2dfd>
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2025-12-17T20:53:59.429356
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relevant economic sectors to work towards reform. the initiatives hoover supported as commerce secretary — and the ways in which he pursued them — reveal his thinking about contemporary life in the united states and about the federal government ' s role in american society. hoover hoped to create a more organized economy that would regularize the business cycle, eliminating damaging ebbs and flows and generating higher rates of economic growth. he believed that eradicating waste and improving efficiency would achieve some of these results — thus, his support for standardization and for statistical research into the workings of the economy. he also believed that the american economy would be healthier if business leaders worked together, and with government officials and experts from the social sciences, in a form of private - sector economic planning. this stance led him to support trade associations — industry - wide cooperative groups wherein information on prices, markets, and products could be exchanged among competitors — which hoover saw as a middle way between competition and monopoly. he insisted, though, that participation in these associations remain voluntary and that the government merely promote and encourage, rather than require, their establishment. hoover hoped that these innovations would strengthen what he saw as the central component of the american experience : individualism. in 1922, hoover published a small book, entitled american individualism, that examined the western intellectual tradition ' s major social philosophies, including individualism, socialism, communism, capitalism, and autocracy. hoover concluded that individualism was the superior principle around which to organize society. he rejected the laissez - faire capitalism of the right and the socialism and communism of the left because he believed that these ideologies hindered rather than helped the individual. instead, hoover sought a " balance of perspective " between right and left that theoretically would create and maintain opportunities for americans to succeed. through enterprises like those he championed as commerce secretary, hoover believed the federal government could facilitate the creation of political, social, and economic conditions in which individual americans could flourish. hoover ' s positions and thinking placed him solidly in the progressive camp of the republican party. as secretary of commerce, hoover emerged as a potential running - mate for coolidge in the 1924 presidential election, though that effort fell short. hoover ' s reputation with the american people reached its peak in 1927, when he took charge of relief efforts following disastrous floods along the mississippi river. the episode displayed hoover at his best : as a humanitarian and leader with the ability to solve problems. when coolidge announced in 1927 that he would not seek reelection, hoover became the leading candidate for the
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subdomain_quantum_field_theory
| 0.488265
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:494a31b6-e8c3-42b2-bcba-79889bce2dfd>
| 3
| 0.35
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2025-12-17T20:53:59.430328
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december 4 is a very special day for the mining industry. this is the feast day of barbara, patron saint for miners and blasters, and globally for all the professions that relate to fire ( firemen, fireworks specialists, etc. ) from her tragic story, which appeared later to be a legend, " the belief became widespread that barbara could control lightning and other manifestations of flame and fire. (... ) miners later developed the use of gunpowder for disintegrating rock, involving manifestations similar to thunder claps and lightning flashes. this led to their need for special protection against accidents from the use of explosives (... ) " ( source : the legend of saint barbara, patron saint of mines in infomine. com ) saint barbara remains a vivid part of mining traditions and heritage. in europe, a statue of saint barbara always stands at the entrance of a tunnel construction site. a lot of mining countries still honor saint barbara, from latin america to asia. many extraction sites have been named after saint barbara ( compania minera santa barbara s. a. in chile, complejo minero santa barbara in mexico, barbara experimental coal mine in poland, st barbara ' s southern cross in australia, etc. ), thereby keeping alive the reputation of saint barbara as our patron saint.
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subdomain_quantum_optics
| 0.465164
| 265
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HuggingFaceFW/fineweb-edu
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<urn:uuid:a000566e-4a70-4760-87f7-1d99f604d6ae>
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2025-12-17T20:53:59.431581
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if it wasn ’ t for earthquakes, humans wouldn ’ t have innovated architecture they wouldn ’ t have looked into new ways of building homes, but the problem is that we got good at it – good to the points our homes won ’ t be destroyed frequently enough aka they won ’ t evolute frequently. if you look around you, there is very few free space - and in those spots you find big centers being eradicated everyday – safe and resistant enough – specially to earthquakes – what on earth will take down those inefficient dumb primitive beton monsters and make room for better buildings in the future? so the problem behind this is the ever expanding gap between technology and architecture : our homes will always be behind technology / progress – they will be always less optimal. i can only imagine how better the earth will be if our houses were “ smart ” or modern enough – it is not science fiction – the way we build stuff is very retarded to say the least when it comes to the material used, energy saving, what a home can “ do ” and it is just not possible “ business wise ” to say : ok, let us destroy and rebuild. before, nature took care of this, slowly and “ less painfully ” as little earthquakes happened, our primitive cities got “ devastated ”, we rebuilt them in a better way but the costs were small. we kept gradually improving till our cities became resistant to medium / high earthquakes. we reached this point of the graph where things slow down, become stable – it is cool not to have the tragedy and misery of earthquakes, but on the other hand there is the hidden and expensive cost of stability and non - progress. it is invisible and super slow but as devastating in its effect as that 2 minutes tragedy called earthquake our homes are costing the earth dearly and suffocating it – we need earthquakes to give engineers another better large - scale chance / try. before i start sounding too embarrassingly enthusiastic about earthquakes and destruction, here is a link on list of earthquakes – it has - main lists of earthquakes - historical earthquakes ( before 1901 ) - list of 20th century earthquakes ( 1901 – 2000 ) - list of 21st century earthquakes ( 2001 – present ) - lists of earthquakes by country - largest earthquakes by magnitude - deadliest earthquakes on record enjoy the read! read more
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subdomain_quantum_mechanics
| 0.434263
| 469
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HuggingFaceFW/fineweb-edu
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<urn:uuid:232a566f-fd11-4f6c-a2c2-97a9dce2484f>
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2025-12-17T20:53:59.433766
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deep - space communication improved with electromagnetic radiation antenna - robert c. dye - technology transfer - ( 505 ) 667 - 3404 electromagnetic radiation antenna has potential for deep - space communication - directed energy - long - range communications - medicine ( oncology ) - radar imaging applications are countermeasure - resistant - communications can be spatially - encrypted - 4 - dimensional volumes of energy can be aimed at a single space - time point for directed energy applications - nonspherical decay of the cusp enables low - power communications and propagation over great distances los alamos national laboratory ( lanl ) researchers have developed the lightslinger, a completely new type of antenna that produces tightly - focused packets of electromagnetic radiation fundamentally different from the emissions of conventional transmitters. the device has potential applications in radar, directed - energy ( non - kinetic kill ), secure communications, ultra - long - range communications ( e. g., deep - space ), medicine ( oncology ) and astrophysics. the lightslinger functions by producing a moving polarization pattern in a ring of alumina. by careful timing of voltages applied to electrodes that surround the alumina, the polarization pattern can be made to move superluminally, i. e., faster than the speed of light in a vacuum. nobel laureate vitaly ginzberg showed both that such superluminal polarization patterns do not violate the principles of special relativity and that they emit electromagnetic radiation. once a source travels faster than the waves that it emits, it can make contributions at multiple retarded times to a signal received instantaneously at a distance. this effect is already well known in acoustics ; when a supersonic airplane accelerates through the speed of sound, a violent “ sonic boom ” is heard many miles away, even if the airplane itself is rather quiet. the lightslinger enables the same thing to be done with electromagnetic radiation ; i. e., a relatively low - power source can make an “ electromagnetic boom ”, an intense concentration of radiowaves at a great distance. the “ electromagnetic boom ” is due to temporal focusing, that is, focusing in the time domain. because of this effect, part of the emitted radiation possesses an intensity that decays with distance r as 1 / r rather than as the conventional inverse square law, 1 / r2. these nonspherically - decaying wavepackets represent a game - changing technology in the applications of electromagnetic radiation. development stage : working prototype patent status : patent pending
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subdomain_quantum_optics
| 0.598924
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:79bc5d65-38cf-489f-b8c5-6800ff88c6f7>
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2025-12-17T20:53:59.436015
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this insightful research by respected israeli scholar nurit peled - elhanan will confirm what palestinian researchers have always known : israel ' s prevailing culture of racism, fundamentalism, support for war crimes, and apartheid against palestinians is mainly a product of an educational system that indoctrinates jewish - israeli students with militant colonial values and extreme racism that turn them into " monsters " once in uniform. guardian : academic claims israeli school textbooks contain bias " nurit peled - elhanan of hebrew university says textbooks depict palestinians as ' terrorists, refugees and primitive farmers " " peled - elhanan, a professor of language and education at the hebrew university of jerusalem, has studied the content of israeli school books for the past five years, and her account, palestine in israeli school books : ideology and propaganda in education, is to be published in the uk this month. she describes what she found as racism – but, more than that, a racism that prepares young israelis for their compulsory military service. " people don ' t really know what their children are reading in textbooks, " she said. " one question that bothers many people is how do you explain the cruel behaviour of israeli soldiers towards palestinians, an indifference to human suffering, the inflicting of suffering. people ask how can these nice jewish boys and girls become monsters once they put on a uniform. i think the major reason for that is education. so i wanted to see how school books represent palestinians. " in " hundreds and hundreds " of books, she claims she did not find one photograph that depicted an arab as a " normal person ". the most important finding in the books she studied – all authorised by the ministry of education – concerned the historical narrative of events in 1948, the year in which israel fought a war to establish itself as an independent state, and hundreds of thousands of palestinians fled the ensuing conflict. the killing of palestinians is depicted as something that was necessary for the survival of the nascent jewish state, she claims. " those who see this as an aberration of zionism seem to lack sufficient understanding of what zionism really is and the central role it plays as a patently racist ideology in justifying ethnic cleansing and racist domination over palestinians. one should not wonder then why, at the height of the israeli massacre in gaza 2008 - 09, a tel aviv university poll ( reported in the jerusalem post, jan. ' 09 ) of jewish - israeli opinion showed a shocking 94 % support for the assault, despite full knowledge of the enormous suffering this israeli aggression had
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subdomain_quantum_field_theory
| 0.470903
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:678fe9bf-3c2f-442f-8e14-46356c50951b>
| 0
| 0.35
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2025-12-17T20:53:59.439147
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massacre in gaza 2008 - 09, a tel aviv university poll ( reported in the jerusalem post, jan. ' 09 ) of jewish - israeli opinion showed a shocking 94 % support for the assault, despite full knowledge of the enormous suffering this israeli aggression had inflicted upon the 1. 5 million palestinians incarcerated in the gaza " prison camp " and of the massive destruction of their civilian infrastructure. as in every other colonial system, only sustained and effective pressure from within as well as from without can put an end to this downward spiral of criminality, impunity and unspoken racism. more bds is needed to end israeli occupation, colonialism and apartheid. other than the obvious benefits to indigenous palestinians, suffering more than six decades of this three - tiered system of israeli oppression, an end to this system of oppression may well transform most israelis from colonial " monsters " into normal humans. ( ed note : nurit peled - elhanan is author of palestine in israeli school books : ideology and propaganda in education. international publisher i. b. tauris description : " she analyzes the presentation of images, maps, layouts and use of language in history, geography and civic studies textbooks, and reveals how the books might be seen to marginalize palestinians, legitimize israeli military action and reinforce jewish - israeli territorial identity. this book provides a fresh scholarly contribution to the israeli - palestinian debate, and will be relevant to the fields of middle east studies and politics more widely. " )
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subdomain_quantum_gravity
| 0.457169
| 298
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HuggingFaceFW/fineweb-edu
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<urn:uuid:678fe9bf-3c2f-442f-8e14-46356c50951b>
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2025-12-17T20:53:59.439688
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historical aerial photographs prior to the trial, jan schlichtmann, the plaintiffs attorney, hired a consulting firm to acquire and analyze historic aerial photographs of the riley 15 - acre property to estimate the times when the various drums, barrels, and debris piles first appeared. the consultants took this analysis and compared it to the 1985 field mapping of the debris piles, drums, and tanks on the 15 - acre property by john drobinski, a geologist hired by schlichtmann. drobinski ' s field map can be downloaded from the trial documents collection and excerpts of his deposition can be downloaded from the trial testimony collection. what are aerial photographs and how are they used? aerial photographs like the ones shown below routinely are taken by the u. s. department of agriculture and u. s. geological survey to make topographic maps, record temporal changes in crop patterns, map geology and mineral resources, and evaluate floodplains. a specialized aircraft with sophisticated cameras is used to take photographs using black & white or color infrared film. the aircraft flies along flight lines that overlap slightly while the camera takes photographs at time intervals that allow the images to overlap. because of the overlap is from two different positions in the sky, the overlapping portions of adjacent images can be viewed in 3 - d. a stereoscope is needed to see the images in 3 - d, which produces a static visual image that is similar to looking at a 3 - d movie using red and blue glasses. thus, tree tops and buildings appear to be higher than surrounding ground, whereas stream channels and wetlands appear to be lower. aerial photographs of the woburn wells g and h area the collection below is a subset of those compiled by maura metheny for her dissertation research at ohio state university. four sets of photographs ( may 1954, may 1969, april 1981, and march 1986 ) are suitable for 3 - d viewing. to do this, print the images on high - quality paper or photographic paper and view them under a stereoscope. an inexpensive plastic ' pocket ' stereoscope works well. the sequence of images below document changes in land use, construction of municipal wells g and h and other structures, changes in the wetland, and the appearance of drums and underground storage tanks along the access road between salem street and olympia avenue on the west side of the river. detailed information about the dates, resolution, scales, and ordering numbers of the sets of aerial photographs shown below is available in this excel file ( excel 19kb jan22 07 ). - may 13, 1954 photographs : 2414
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subdomain_quantum_gravity
| 0.464722
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HuggingFaceFW/fineweb-edu
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<urn:uuid:a34828e1-9706-4e67-be65-8fb8a94ec846>
| 0
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2025-12-17T20:53:59.443384
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of the river. detailed information about the dates, resolution, scales, and ordering numbers of the sets of aerial photographs shown below is available in this excel file ( excel 19kb jan22 07 ). - may 13, 1954 photographs : 2414, 2415, 2416, 2417 northern image full resolution ( 28. 5mb mar14 07 ) north - central image full resolution ( 29. 3mb mar14 07 ) south - central image full resolution ( 28. 3mb mar14 07 ) southern image full resolution ( 28. 5mb mar14 07 ) - april 29, 1963 photographs : 278, 279 western image full resolution ( 288kb mar15 07 ) eastern image full resolution ( 208kb mar15 07 ) - april 6, 1965 photograph : 233 full resolution ( 269kb mar15 07 ) - may 1, 1969 photographs : 1684, 1685, 1686, 1687 south image full resolution ( 288kb mar15 07 ) south - central image full resolution ( 284kb mar15 07 ) north - central image full resolution ( 281kb mar15 07 ) north image full resolution ( 273kb mar15 07 ) - july 3, 1971 photograph : 126 full resolution ( 377kb mar15 07 ) - april 23, 1978 photographs : 104 north and south north images full resolution ( 73kb mar15 07 ) south image full resolution ( 77kb mar15 07 ) - april 13, 1981 photographs : 19 - 5, 19 - 6, 19 - 7 south image full resolution ( 205kb mar15 07 ) middle image full resolution ( 196kb mar15 07 ) north image full resolution ( 196kb mar15 07 )
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subdomain_quantum_gravity
| 0.436101
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HuggingFaceFW/fineweb-edu
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<urn:uuid:a34828e1-9706-4e67-be65-8fb8a94ec846>
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2025-12-17T20:53:59.443996
|
two teachers at norview high school in norfolk, va were recently put on administrative leave by the school after a parent complained about a video that she saw in government class. the video informed its audience on how to assert their constitutional rights during various encounters with police, such as during a car or house search. it was accompanied by a one page handout about a person ’ s rights when stopped and arrested by the police. when the girl came home after school that day, she told her mother “ you won ’ t believe what we are learning in government. they are teaching us how to hide our drugs. ” the woman promptly called the school to complain about what was taught to her daughter, and the teachers were subsequently suspended. there are two things that are rather irksome about these series of events. first, why are parents are so ready to jump to conclusions and act on those assumptions? it ’ s a little hard to believe that teachers would be lecturing their students on the best way to hide drugs from the police. if the girl ’ s mother had just inquired as to what was actually taught that day, it would have been clear that this was government class as usual, just an exercise in educating youth on the constitution. second, and more importantly, why are schools eager to appease parents at the drop of a hat? these are institutions filled with education professionals : teachers know what their students should learn and what the appropriate materials for teaching them are. a school ’ s administration should trust that the teacher is making reasonable choices as to how a child is taught and with what. in response to a parent ’ s complaint, they should first research the allegations. the administration at norview high school, for instance, could have a gotten a copy of the leaflet given to students. they also could have watched the video to see if anything inappropriate was shown. instead, the school acquiesced to the demands of one uninformed parent. sometimes, mother doesn ’ t know what ’ s best. that ’ s why we have schools and teachers. unfortunately, this is not a new problem. schools all over the country have bowed down to raging parents over something they don ’ t think is appropriate for their child. it ’ s a distressing thought that a parent ’ s misunderstanding about a certain book or a particular lesson in school can translate into a child ’ s incomplete education. learning about an individual ’ s constitutional rights enhances one ’ s education and can even make for a better citizen. school administrators need to have more confidence in themselves
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subdomain_quantum_cryptography
| 0.467298
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HuggingFaceFW/fineweb-edu
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<urn:uuid:a4dee370-849c-4c50-bca2-fa569742a920>
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2025-12-17T20:53:59.446433
|
jim lake and maria rivera, at the university of california - los angeles ( ucla ), report their finding in the sept. 9 issue of the journal nature. scientists refer to both bacteria and archaea as " prokaryotes " - - a cell type that has no distinct nucleus to contain the genetic material, dna, and few other specialized components. more - complex cells, known as " eukaryotes, " contain a well - defined nucleus as well as compartmentalized " organelles " that carry out metabolism and transport molecules throughout the cell. yeast cells are some of the most - primitive eukaryotes, whereas the highly specialized cells of human beings and other mammals are among the most complex. " a major unsolved question in biology has been where eukaryotes came from, where we came from, " lake said. " the answer is that we have two parents, and we now know who those parents were. " further, he added, the results provide a new picture of evolutionary pathways. " at least 2 billion years ago, ancestors of these two diverse prokaryotic groups fused their genomes to form the first eukaryote, and in the processes two different branches of the tree of life were fused to form the ring of life, " lake said. the work is part of an effort supported by the national science foundation - - the federal agency that supports research and education across all disciplines of science and engineering - - to re - examine historical schemes for classifying earth ' s living creatures, a process that was once based on easily observable traits. microbes, plants or animals wer contact : leslie fink national science foundation
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subdomain_quantum_gravity
| 0.527776
| 338
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HuggingFaceFW/fineweb-edu
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<urn:uuid:baf824b2-7e06-471a-8510-efd5abab1567>
| 0
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2025-12-17T20:53:59.450039
|
sudden death syndrome - - an umbrella term for a range of heart conditions that can lead to cardiac arrest - - is notorious for striking those who seem most fit. that is because the condition, thought to be largely hereditary, is often triggered by overexertion. tragically for some, the first symptom can be cardiac arrest. it ' s possible, though costly, to screen for sds. in fact, after soccer prodigy john marshall died of a sudden heart attack at age 16 in 1994, the day before he was set to join everton, testing became compulsory for professional athletes in several countries. good thing, especially for those who don ' t have the means that professional athletes do, that a doctor at tel aviv university may have just made testing for the condition far simpler and more affordable. " there is such a significant overlap between what ' s normal and abnormal on an ecg [ electrocardiogram ] that we need additional screening parameters, " dr. sami viskin, a cardiologist at the sackler faculty of medicine, said yesterday in a university press release. " this test, when done on people with strong symptoms, can really give... doctors a yardstick to compare those at risk for sudden death syndrome to those who would otherwise go on to live a healthy life. " named after the doctor, the viskin test is easy on the patient, who simply undergoes a baseline ecg while resting in the supine position, and is then asked to stand quickly and remain still during continuous ecg recording. … read more
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subdomain_quantum_mechanics
| 0.47224
| 313
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HuggingFaceFW/fineweb-edu
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<urn:uuid:8fedc1ae-d9da-4da5-9da7-31e4b337c8fc>
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2025-12-17T20:53:59.451591
|
the test team views the use of a pulley as an intermediate step only, and has planned to shift to a reliance on windlasses like those that apparently were used to hoist sails on egyptian ships. " the whole approach has been to downgrade the technology, " gharib said. " we first wanted to show that a kite could raise a huge weight at all. now that we ' re raising larger and larger stones, we ' re also preparing to replace the steel scaffolding with wooden poles and the steel pulleys with wooden pulleys like the ones they may have used on egyptian ships. " for gharib, the idea of accomplishing heavy tasks with limited manpower is appealing from an engineer ' s standpoint because it makes more logistical sense. " you can imagine how hard it is to coordinate the activities of hundreds if not thousands of laborers to accomplish an intricate task, " said gharib. " it ' s one thing to send thousands of soldiers to attack another army on a battlefield. but an engineering project requires everything to be put precisely into place. " i prefer to think of the technology as simple, with relatively few people involved, " he explained. gharib and graff came up with a way of building a simple structure around the obelisk, with a pulley system mounted in front of the stone. that way, the base of the obelisk would drag on the ground for a few feet as the kite lifted the stone, and the stone would be quite stable once it was pulled upright into a vertical position. if the obelisk were raised with the base as a pivot, the stone would tend to swing past the vertical position and fall the other way. the top of the obelisk is tied with ropes threaded through the pulleys and attached to the kite. the operation is guided by a couple of workers using ropes attached to the pulleys. no one has found any evidence that the ancient egyptians moved stones or any other objects with kites and pulleys. but clemmons has found some tantalizing hints that the project is on the right track. on a building frieze in a cairo museum, there is a wing pattern in bas - relief that does not resemble any living bird. directly below are several men standing near vertical objects that could be ropes. gharib ' s interest in the project is mainly to demonstrate that the technique may be viable. " we ' re not egyptologists, " he said. " we ' re
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subdomain_quantum_thermodynamics
| 0.466277
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:7989d2d3-3e6d-4a4d-ad8e-e7b19882a89a>
| 0
| 0.35
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2025-12-17T20:53:59.455027
|
facilitator ' s guide for the beloved community a film by pamela calvert / plain speech at the fenceline of canada ' s " chemical valley, " girls are being born at twice the rate of boys. how do you stay in the home you love when the price you pay may be your children ' s future? planning a screening topics and issues relevant to the beloved community as you plan your screening, you might consider speakers, panelists, or discussion leaders who have expertise in one or more of the following - children ' s health - community organizing - corporate social responsibility - endocrine disruptors - environmental justice - green chemistry - human rights - native culture, history & land rights - precautionary principle - reproductive health - toxic exposure & health impacts - workplace health and safety as you plan your event a screening of the beloved community can be used to spark interest in any of the topics listed above, as well as to inspire individual and community action. using the checklist below will help ensure a high quality and high impact event. set realistic goals. will you host a single screening or use the film to spur ongoing efforts? will you steer a panel or discussion toward a specific topic or let the participants pursue whatever issues they choose? be sure to include your event partners in the decision making process. being clear about your goals will make it much easier to structure the event, target publicity, and evaluate results. structure your event to match your goals. do you need an outside facilitator? if your goal is to share information beyond what is included in the film, are there local experts on the topic who should be present? how many participants do you want? ( large groups are appropriate for information exchange. small groups allow for more intensive dialogue and action plans. ) arrange to involve all stakeholders. it is especially important that people be allowed to speak for themselves. we encourage you to seek out ' unlikely alliances ' and push your own comfort zone, going out of your way to invite representatives of all the constituencies with a potential stake in building a healthy and sustainable community. once the group is assembled, make sure that all participants have a chance to be heard and are treated with respect. choose an accessible venue. if you are bringing together different constituencies, is your venue ' neutral territory '? is it in a part of town that is reachable by various kinds of transportation? does the physical configuration of the room allow for the kind of discussion you hope to have? can everyone easily see the screen and hear the film? is the room comfortable?
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subdomain_quantum_field_theory
| 0.472486
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:e3b68342-7f9a-4821-8e28-91910e265a4c>
| 0
| 0.35
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2025-12-17T20:53:59.459086
|
it in a part of town that is reachable by various kinds of transportation? does the physical configuration of the room allow for the kind of discussion you hope to have? can everyone easily see the screen and hear the film? is the room comfortable? leave time for feelings. when the lights come up, people may have a strong emotional response to the film. this is where people make the empathetic connections that make all the following work possible, so it ' s important to encourage that personal response before moving on to questions of strategy. the conversation will naturally flow into " what do we do now? " leave time to plan for action. if you want your screening to have lasting impact, it is important to leave time to plan action. people will be looking for something that is immediate, concrete, and local. planning next steps can help people leave the room feeling energized and optimistic, even when the discussion has been difficult. it ' s also important to be prepared to facilitate networking. provide a sign - in sheet at the door so people can share contact information like email addresses. let participants know exactly how that information will ( and won ' t ) be shared. let participants know whether or not press will be present. facilitating a discussion of the beloved community people who feel safe, encouraged, respected and challenged are likely to share openly and thoughtfully. as a facilitator you can encourage that kind of participation. here ' s how : view the film before your event. this will both give yourself time to reflect so you aren ' t dealing with raw emotions at the same time that you are trying to facilitate a discussion, as well as letting you check the dvd and equipment to make sure there are no technical glitches. you may want to refer to the discussion guide to get you started. you don ' t need to be an expert on globalization or environmental justice to lead an event, but knowing the basics can help you keep a discussion on track and gently correct misstatements of fact. prior to your event, take time to check the background information and suggested resources in the film guide handout. be clear about your role. being a facilitator is not the same as being a teacher. a teacher ' s job is to convey specific information. in contrast, a facilitator remains neutral, helping move the discussion along without imposing her or his views on the dialogue. know who might be present. it isn ' t always possible to know exactly who might attend a screening, but if you know what kinds of
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subdomain_quantum_optics
| 0.466973
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:e3b68342-7f9a-4821-8e28-91910e265a4c>
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2025-12-17T20:53:59.460121
|
refraction and acceleration name : christopher s. why is it that when light travels from a more dense to a less dense medium, its speed is higher? i ' ve read answers to this question in your archives but, sadly, still don ' t get it. one answer ( jasjeet s bagla ) says that we must not ask the question because light is massless, hence questions of acceleration don ' t make sense. it does, however, seem to be ok to talk about different speeds of light. if you start at one speed and end at a higher one, why is one not allowed to talk about acceleration? bagla goes on to say that it depends on how the em fields behave in a given medium. it begs the question : what is it about, say, perspex and air that makes light accelerate, oops, travel at different speeds? if you ' re dealing with the same ray of light, one is forced to speak of acceleration, no? what other explanation is there for final velocity > initial velocity? arthur smith mentioned a very small " evanescent " component that travels ahead at c. where can i learn more about this? sorry for the long question. i understand that f = ma and if there is no m, you cannot talk about a, but, again, you have one velocity higher than another for the same thing. i need to know more than " that ' s just the way em fields are! " an explanation that satisfies me relates to travel through an interactive medium. when light interacts with an atom, the photon of light is absorbed and then emitted. for a moment, the energy of the light is within the atom. this causes a slight delay. light travels at the standard speed of light until interacting with another atom. it is absorbed and emitted, causing another slight delay. the average effect is taking more time to travel a meter through glass than through air. this works like a slower speed. an individual photon does not actually slow down. it gets delayed repeatedly by the atoms of the medium. a more dense medium has more atoms per meter to dr. ken mellendorf illinois central college congratulations! on not being willing to accept " that is just the way em fields are! " the answer to your inquiry is not all that simple ( my opinion ), but i won ' t try to do so in the limited space allowed here, not to say my own limitations of knowledge. like so many " simple " physics questions, i find the most lucid
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subdomain_quantum_optics
| 0.599143
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:d2b35c16-35c7-477e-80c7-8dded3739ec4>
| 0
| 0.35
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2025-12-17T20:53:59.464761
|
is not all that simple ( my opinion ), but i won ' t try to do so in the limited space allowed here, not to say my own limitations of knowledge. like so many " simple " physics questions, i find the most lucid, but accurate, explanation in richard feynman ' s, " lectures on physics " which most libraries will have. volume i, chapter 31 - 1 through 31 - 6, which describes refraction, dispersion, diffraction. the " answer " has to do with how matter alters the electric field of incident radiation, but i won ' t pretend to be able to do a better job than feynman. the answer is that you are not dealing with the same ray of light. in vacuum a photon just keeps going at the speed of light. in a medium, however, it interacts with the atoms, often being absorbed while bumping an atomic or molecular motion into a higher energy state. the excited atom / molecule then can jump to a lower energy state, emitting a photon while doing so. this can obviously make light appear to travel slower in a in detail, it is a very complicated question, requiring at least a graduate course in electromagnetism to begin to understand. why, for example do the emitted photons tend to travel in the same direction? best, richard j. plano click here to return to the physics archives update : june 2012
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subdomain_quantum_optics
| 0.626201
| 290
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HuggingFaceFW/fineweb-edu
|
<urn:uuid:d2b35c16-35c7-477e-80c7-8dded3739ec4>
| 1
| 0.35
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2025-12-17T20:53:59.465301
|
attempts to relay mail by issuing a predefined combination of smtp commands. the goal of this script is to tell if a smtp server is vulnerable to mail relaying. an smtp server that works as an open relay, is a email server that does not verify if the user is authorised to send email from the specified email address. therefore, users would be able to send email originating from any third - party email address that they want. the checks are done based in combinations of mail from and rcpt to commands. the list is hardcoded in the source file. the script will output all the working combinations that the server allows if nmap is in verbose mode otherwise the script will print the number of successful tests. the script will not output if the server requires authentication. if debug is enabled and an error occurrs while testing the target host, the error will be printed with the list of any combinations that were found prior to the error. use this to change the ip address to be used ( default is the target ip address ) define the destination email address to be used ( without the domain, default is relaytest ) or smtp - open - relay. domain define the domain to be used in the anti - spam tests and ehlo command ( default is nmap. scanme. org ) define the source email address to be used ( without the domain, default is antispam ) smbdomain, smbhash, smbnoguest, smbpassword, smbtype, smbusernamesee the documentation for the smbauth library. nmap - - script smtp - open - relay. nse [ - - script - args smtp - open - relay. domain = < domain >, smtp - open - relay. ip = < address >,... ] - p 25, 465, 587 < host > host script results : | smtp - open - relay : server is an open relay ( 1 / 16 tests ) | _ mail from : < email @ example. com > - > rcpt to : < firstname. lastname @ example. org > author : arturo ' buanzo ' busleiman license : same as nmap - - see http : / / nmap. org / book / man - legal. html
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subdomain_quantum_cryptography
| 0.516141
| 477
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HuggingFaceFW/fineweb-edu
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<urn:uuid:2fc62870-a21f-42bb-90f1-0b5d5c8d75a5>
| 0
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2025-12-17T20:53:59.467275
|
how much fun is it to be a child in your home? do you ever stop to think about how the house looks from their point of view? my task for this week is to conduct a child ’ s eye audit of our living space, to try and make the rooms more child - and play - friendly. the audit need only take a few minutes and might suggest simple changes to make to improve the play space. to conduct a child ’ s eye audit, sit or kneel down so you ’ re at your child ’ s eye - level and consider the following things. 1. safety first. most importantly, the room needs to be safe and it ’ s useful t0 review this aspect of your home from time to time as children grow taller, become more mobile or more adventurous. think about what your child can reach, what you don ’ t want them to reach and make any necessary adjustments. 2. child ’ s eye view. sit back for a minute on the floor and scan the room. what ’ s visible to your child at their height, and what ’ s not? you might display all their lovely paintings on the wall and fridge door – but are they too high for your child to actually see? is their view just of empty walls? hang some art work at a lower level or set up a low shelf or table with a display of things they can enjoy. 3. within reach. consider how accessible your toys are. do you have an enabling environment where your child can independently help themselves to toys and resources to use in their play or is everything out of reach? try to find a balance so you can keep the space tidy whilst still allowing free access. open shelving and low baskets work well for us with some materials such as paint stored higher up. 4. ring the changes. do you always have they same toys out? sometimes putting away familiar toys and bringing out some forgotten ones can spark new creativity and fun. don ’ t have a complete change of resources though, as children do like to know where favourite toys are. with christmas on the way now is a good time to have a toy audit, donating ones your child has grown out of to the charity shop and getting ideas for their christmas list. 5. invitation to play. do you have any toys that never get played with, or activities that you child rarely takes part in? what can you change to make things more inviting? if you ’ d like to encourage some more reading, perhaps you could set up a cosy reading corner or story tent –
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subdomain_quantum_metrology
| 0.439662
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:f1607610-8673-4722-9f25-b0d9f0cf0ce3>
| 0
| 0.35
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2025-12-17T20:53:59.474326
|
never get played with, or activities that you child rarely takes part in? what can you change to make things more inviting? if you ’ d like to encourage some more reading, perhaps you could set up a cosy reading corner or story tent – with comfy cushions, a basket of tempting books and a favourite teddy to share with? if your toy kitchen has been ignored for a while, add some new resources to catch your child ’ s eye : a muffin tin and paper cake cases, some jars of real dried pasta, a recipe book from your shelf or lay the table for a birthday tea and surprise your child with a new play possibility. do you sometimes review things from your child ’ s point of view? what changes have you made to make your space more child - and play - friendly? leave a comment and share an idea with us. i ’ m writing this at one o ’ clock in the afternoon and the sky is grey and the rain is tumbling down. it ’ s making me think about how the weather affects our play, and particularly i ’ m thinking about how much time we spend outdoors in autumn and winter. i don ’ t think there ’ s any question that playing outside is wonderful for children : the fresh air, the feeling of space, the sensory benefits of being in nature. i certainly know with my own two girls, and all the children i ’ ve looked after, that if we ’ re having a grumpy sort of day, getting outside – in the garden, park or just for a walk – most often is all that ’ s needed to lighten everyone ’ s mood. but it ’ s getting colder now, and windy and rainy and dark. if you ’ re the type who is happy to be outside all the time in all weathers, i really do salute you. i however am naturally inclined to prefer a hot cup of coffee and a warm blanket inside! we do play outside everyday, whatever the weather, but there ’ s no denying we play outdoors less in winter – which i ’ m guessing is the same for lots of you? so, i ’ m resolving to put more thought into getting out there and planning on bringing you some posts over the next few months that inspire us to venture out. i ’ d also like to invite you to share your ideas too. the play academy carnival on friday is open to any of your posts and i ’ d also love to hear from you if you ’ d like to write a guest post here. ( on any play subject in fact,
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subdomain_quantum_gravity
| 0.462411
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:f1607610-8673-4722-9f25-b0d9f0cf0ce3>
| 1
| 0.35
|
2025-12-17T20:53:59.475250
|
you to share your ideas too. the play academy carnival on friday is open to any of your posts and i ’ d also love to hear from you if you ’ d like to write a guest post here. ( on any play subject in fact, not just on playing outside. you can e - mail me cathy ( at ) nurturestore ( dot ) co ( dot ) uk if you have an idea you ’ d like to write about ). to start us off, my top three tips for getting outside, whatever the weather are … - keep yourself warm. if you ’ re wearing the right clothes, you ’ re much more likely to enjoy your time outside. pretty much all the children i know don ’ t care if it ’ s cold, windy or raining – they are active kids and just love being outside. so, to help everyone enjoy themselves outside, and to stop you cutting short the children ’ s outdoor fun because you ’ ve had enough, my first tip is to make sure you are wearing the right clothes. layer up, don ’ t forget your hat and gloves and make sure you are cosy. - get active. we ’ re going to shift our outdoor play away from fairy gardens and dinosaur world ’ s and include lots more active games. hopscotch, skipping, what ’ s the time mr. wolf are great fun and will keep everyone on the move. - audit your outdoor space. now is a good time to review your garden and get it ready for the colder months. think about what you play outside and re - locate things or make changes to suit the weather. we ’ ll move the sandpit and den to under our covered area and make sure there are lots of props outside ready to spark active play ( bikes, balls, kites, hula hoops ). we ’ re not likely to do as much water play outside, so i ’ ll be thinking of ways to bring this inside. what about you – are you an all weather family? how do you promote lots of outdoor play, whatever the weather? back in january i resolved to make 2010 our year of play. i ’ ve been thinking about this again this month as l has started at school. in last week ’ s play academy link - up i talked about wanting to make sure the girls still have lots of opportunity for playing, as well as schooling. so this weeks twitter tips are dedicated to having a playful return to school. the twitter tips get tweeted on a friday at 8. 30pm and in previous weeks
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subdomain_quantum_gravity
| 0.429567
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:f1607610-8673-4722-9f25-b0d9f0cf0ce3>
| 2
| 0.35
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2025-12-17T20:53:59.476255
|
sure the girls still have lots of opportunity for playing, as well as schooling. so this weeks twitter tips are dedicated to having a playful return to school. the twitter tips get tweeted on a friday at 8. 30pm and in previous weeks they ’ ve started great twitter conversations, with people swapping ideas. the main thing i love about blogging is it being a forum to get inspiration and encouragement from others, so please feel free to add your own ideas in the comments or on our facebook page. join in, swap ideas, go play! how to have a playful back to school # goplay twitter tip # 1if you ’ re using after school clubs check how playful they are : do they offer free play after a structured school day # goplay twitter tip # 2make the school run fun : cycle, scoot or play i - spy. leave a little earlier to let the kids play a bit before class # goplay twitter tip # 3 set up a play invitation in the morning to entice the kids to play before they switch on the tv # goplay twitter tip # 4 rediscover some old school favourites such as conkers or fortune tellers # goplay twitter tip # 5 consider how many clubs to join so after school play time isn ’ t lost in a busy schedule. # goplay twitter tip # 6 encourage playground fun by packing a skipping rope in the book bag. ready for ten has a great skipping tutuorial # goplay twitter tip # 7 plan family time for the weekend : it doesn ’ t have to be expensive or extravagant but do make sure it happens. # goplay twitter tip # 8 consider screen time. could your kids live without tv for an hour, a day, a week? what could they play instead? # goplay twitter tip # 9 locate the park nearest your school and stop off any day day you can on the way home. enjoy some # playoutdoors # goplay twitter tip # 10 instead of only setting up a homework area set up a play area too. add untoys & let them # goplay how do you feel about the balance between school and play time? how do you manage homework at the weekend? do your kids attend a playful school? happily shared with top ten tuesday. use the linky below to add your post to the play academy our summer holidays are drawing to a close and my little is starting school on monday ( oh my! ). i feel very strongly that our play should keep going. b is moving
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subdomain_quantum_gravity
| 0.424091
| 512
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HuggingFaceFW/fineweb-edu
|
<urn:uuid:f1607610-8673-4722-9f25-b0d9f0cf0ce3>
| 3
| 0.35
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2025-12-17T20:53:59.478228
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. use the linky below to add your post to the play academy our summer holidays are drawing to a close and my little is starting school on monday ( oh my! ). i feel very strongly that our play should keep going. b is moving up to the juniors and although her school offers are great curriculum including play, art, music, drama and experiments i think it ’ s inevitable that her lessons will become more and more about schooling. september always feels like the start of the year to me, so i ’ m keeping in mind my resolution to make 2010 our year of play, and we ’ ll certainly be limiting our after school clubs and weekend commitments to allow plenty of time for playing. how do you feel about finding a balance between schooling ( or home educating ) and play? i ’ m looking forward to getting even more inspiration from your play academy ideas this week – hope you ’ ll add a link. 1. add your post to the linky below. remember to link to the individual post rather than your homepage. if you are not a blogger please visit the nurturestore facebook page and share your photo there. 2. go and visit some of the other blogs on the linky. leave a comment and say hi. get ideas. tell them you ’ re visiting from the play academy. 3. add a link back from your own post to this play academy – your readers can then come and get ideas too. you can use the play academy badge if you like. ( grab the code from the column on the left. ) 4. come back next friday and swap some more play ideas. the next play academy linky will be friday 10th september.
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subdomain_quantum_gravity
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2025-12-17T20:53:59.478981
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this collection consists of digital images of the correspondence of john muir from 1856 - 1914. the vast majority of the letters were sent and received by muir, although the collection also includes some correspondence of selected family members and colleagues. muir ’ s correspondence offers a unique first - hand perspective on his thoughts and experiences, as well as those of his correspondents, which include many notable figures in scientific, literary, and political circles of the 19th and early 20th centuries. the correspondence forms part of the john muir papers microfilm set that filmed letters located at over 35 institutions. a scottish - born journalist and naturalist, john muir ( 1838 - 1914 ) studied botany and geology at the university of wisconsin ( 1861 - 1863 ). he worked for awhile as a mill hand at the trout broom factory in meaford, canada ( 1864 - 1866 ), then at an indianapolis carriage factory ( 1866 - 1867 ), until an accident temporarily blinded him and directed his thoughts toward full - time nature study. striking out on foot for south america, muir walked to the gulf of mexico ( september 1867 - january 1868 ), but a long illness in florida led him to change his plans and turn his interests westward. muir arrived by ship at san francisco ( march 1868 ), walked to the sierra nevada mountains and began a five year wilderness sojourn ( 1868 - 1873 ) during which he made his year - round home in the yosemite valley. working as a sheepherder and lumberman when he needed money for supplies, muir investigated the length and breadth of the sierra range, focusing most of his attention on glaciation and its impact on mountain topography. he began to publish newspaper articles about what he saw in the california mountains and these articles brought him to the attention of such intellectuals as asa gray and ralph waldo emerson, both of whom sought him out during their visits to california. encouraged by jeanne carr, wife of his one - time botany professor, ezra s. carr, muir took up nature writing as a profession ( 1872 ). he set up winter headquarters in oakland and began a pattern of spring and summer mountaineering followed by winter writing based upon his travel journals that he held to until 1880. his treks took him to mount shasta ( 1874, 1875 & 1877 ), the great basin ( 1876, 1877, 1878 ), southern california and the coast range ( 1877 ), and southern alaska ( 1879 ). muir found that he could finance his modest bachelor lifestyle with revenue from contributions published in various san francisco newspapers and magazines. during this period he launched the first
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subdomain_quantum_gravity
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HuggingFaceFW/fineweb-edu
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<urn:uuid:6f2a750f-0c38-4b95-86ad-7af20a393eac>
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2025-12-17T20:53:59.482706
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topics covered : ideal solutions instructor / speaker : moungi bawendi, keith nelson the following content is provided under a creative commons license. your support will help mit opencourseware continue to offer high quality educational resources for free. to make a donation or view additional materials from hundreds of mit courses, visit mit opencourseware at ocw. mit. edu. professor : so. in the meantime, you ' ve started looking at two phase equilibrium. so now we ' re starting to look at mixtures. and so now we have more than one constituent. and we have more than one phase present. right? so you ' ve started to look at things that look like this, where you ' ve got, let ' s say, two components. both in the gas phase. and now to try to figure out what the phase equilibria look like. of course it ' s now a little bit more complicated than what you went through before, where you can get pressure temperature phase diagrams with just a single component. now we want to worry about what ' s the composition. of each of the components. in each of the phases. and what ' s the temperature and the pressure. total and partial pressures and all of that. so you can really figure out everything about both phases. and there are all sorts of important reasons to do that, obviously lots of chemistry happens in liquid mixtures. some in gas mixtures. some where they ' re in equilibrium. all sorts of chemical processes. distillation, for example, takes advantage of the properties of liquid and gas mixtures. where one of them might be richer, will be richer, and the more volatile of the components. that can be used as a basis for purification. you mix ethanol and water together so you ' ve got a liquid with a certain composition of each. the gas is going to be richer and the more volatile of the two, the ethanol. so in a distillation, where you put things up in the gas, more of the ethanol comes up. you could then collect that gas, right? and re - condense it, and make a new liquid. which is much richer in ethanol than the original liquid was. then you could make, then you could put some of them up into the gas phase. where it will be still richer in ethanol. and then you could collect that and repeat the process. so the point is that properties of liquid gas, two - component or multi - component mixtures like this can
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subdomain_quantum_thermodynamics
| 0.605124
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.507264
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of them up into the gas phase. where it will be still richer in ethanol. and then you could collect that and repeat the process. so the point is that properties of liquid gas, two - component or multi - component mixtures like this can be exploited. basically, the different volatilities of the different components can be exploited for things like purification. also if you want to calculate chemical equilibria in the liquid and gas phase, of course, now you ' ve seen chemical equilibrium, so the amount of reaction depends on the composition. so of course if you want reactions to go, then this also can be exploited by looking at which phase might be richer in one reactant or another. and thereby pushing the equilibrium toward one direction or the other. ok. so. we ' ve got some total temperature and pressure. and we have compositions. so in the gas phase, we ' ve got mole fractions ya and yb. in the liquid phase we ' ve got mole fractions xa and xb. so that ' s our system. one of the things that you established last time is that, so there are the total number of variables including the temperature and the pressure. and let ' s say the mole fraction of a in each of the liquid and gas phases, right? but then there are constraints. because the chemical potentials have to be equal, right? chemical potential of a has to be equal in the liquid and gas. same with b. those two constraints reduce the number of independent variables. so there ' ll be two in this case rather than four independent variables. if you control those, then everything else will follow. what that means is if you ' ve got a, if you control, if you fix the temperature and the total pressure, everything else should be determinable. no more free variables. and then, what you saw is that in simple or ideal liquid mixtures, a result called raoult ' s law would hold. which just says that the partial pressure of a is equal to the mole fraction of a in the liquid times the pressure of pure a over the liquid. and so what this gives you is a diagram that looks like this. if we plot this versus xb, this is mole fraction of b in the liquid going from zero to one. then we could construct a diagram of this sort. so this is the total pressure of a and b. the partial pressures are given by these lines. so this is our pa star and pb star. the pressures over
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subdomain_quantum_thermodynamics
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.508159
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going from zero to one. then we could construct a diagram of this sort. so this is the total pressure of a and b. the partial pressures are given by these lines. so this is our pa star and pb star. the pressures over the pure liquid a and b at the limits of mole fraction of b being zero and one. so in this situation, for example, a is the more volatile of the components. so it ' s partial pressure over its pure liquid. at this temperature. is higher than the partial pressure of b over its pure liquid. a would be the ethanol, for example and b the water in that mixture. ok. then you started looking at both the gas and the liquid phase in the same diagram. so this is the mole fraction of the liquid. if you look and see, well, ok now we should be able to determine the mole fraction in the gas as well. again, if we note total temperature and pressure, everything else must follow. and so, you saw this worked out. relation between p and ya, for example. the result was p is pa star times pb star over pa star plus pb star minus pa star times ya. and the point here is that unlike this case, where you have a linear relationship, the relationship between the pressure and the liquid mole fraction isn ' t linear. we can still plot it, of course. so if we do that, then we end up with a diagram that looks like the following. now i ' m going to keep both mole fractions, xb and yb, i ' ve got some total pressure. i still have my linear relationship. and then i have a non - linear relationship between the pressure and the mole fraction in the gas phase. so let ' s just fill this in. here is pa star still. here ' s pb star. of course, at the limits they ' re still, both mole fractions they ' re zero and one. ok. i believe this is this is where you ended up at the end of the last lecture. but it ' s probably not so clear exactly how you read something like this. and use it. it ' s extremely useful. you just have to kind of learn how to follow what happens in a diagram like this. and that ' s what i want to spend some of today doing. is just, walking through what ' s happening physically, with a container with a mixture of the two. and how does that correspond to what gets read off the diagram under different
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subdomain_quantum_optics
| 0.581275
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
| 2
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2025-12-17T20:53:59.508995
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. and that ' s what i want to spend some of today doing. is just, walking through what ' s happening physically, with a container with a mixture of the two. and how does that correspond to what gets read off the diagram under different conditions. so. let ' s just start somewhere on a phase diagram like this. let ' s start up here at some point one, so we ' re in the pure - well, not pure, you ' re in the all liquid phase. it ' s still a mixture. it ' s not a pure substance. pa star, pb star. there ' s the gas phase. so, if we start at one, and now there ' s some total pressure. and now we ' re going to reduce it. what happens? we start with a pure - with an all - liquid mixture. no gas. and now we ' re going to bring down the pressure. allowing some of the liquid to go up into the gas phase. so, we can do that. and once we reach point two, then we find a coexistence curve. now the liquid and gas are going to coexist. so this is the liquid phase. and that means that this must be xb. and it ' s xb at one, but it ' s also xb at two, and i want to emphasize that. so let ' s put our pressure for two. and if we go over here, this is telling us about the mole fraction in the gas phase. that ' s what these curves are, remember. so this is the one that ' s showing us the mole fraction in the liquid phase. this nonlinear one in the gas phase. so that means just reading off it, this is xb, that ' s the liquid mole fraction. here ' s yb. the gas mole fraction. they ' re not the same, right, because of course the components have different volatility. a ' s more volatile. so that means that the mole fraction of b in the liquid phase is higher than the mole fraction of b in the gas phase. because a is the more volatile component. so more, relatively more, of a, the mole fraction of a is going to be higher up in the gas phase. which means the mole fraction of b is lower in the gas phase. so, yb less than xb if a is more volatile. ok, so now what ' s happening physically? well, we started at a point where we only had the
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subdomain_quantum_field_theory
| 0.596711
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.510498
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which means the mole fraction of b is lower in the gas phase. so, yb less than xb if a is more volatile. ok, so now what ' s happening physically? well, we started at a point where we only had the liquid present. so at our initial pressure, we just have all liquid. there ' s some xb at one. that ' s all there is, there isn ' t any gas yet. now, what happened here? well, now we lowered the pressure. so you could imagine, well, we made the box bigger. now, if the liquid was under pressure, being squeezed by the box, right then you could make the box a little bit bigger. and there ' s still no gas. that ' s moving down like this. but then you get to a point where there ' s just barely any pressure on top of the liquid. and then you keep expanding the box. now some gas is going to form. so now we ' re going to go to our case two. we ' ve got a bigger box. and now, right around where this was, this is going to be liquid. and there ' s gas up here. so up here is yb at pressure two. here ' s xb at pressure two. liquid and gas. so that ' s where we are at point two here. now, what happens if we keep going? let ' s lower the pressure some more. well, we can lower it and do this. but really if we want to see what ' s happening in each of the phases, we have to stay on the coexistence curves. those are what tell us what the pressures are. what the partial pressure are going to be in each of the phases. in each of the two, in the liquid and the gas phases. so let ' s say we lower the pressure a little more. what ' s going to happen is, then we ' ll end up somewhere over here. in the liquid, and that ' ll correspond to something over here in the gas. so here ' s three. so now we ' re going to have, that ' s going to be xb at pressure three. and over here is going to be yb at pressure three. and all we ' ve done, of course, is we ' ve just expanded this further. so now we ' ve got a still taller box. and the liquid is going to be a little lower because some of it has evaporated, formed the gas phase
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subdomain_quantum_field_theory
| 0.572187
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
| 4
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2025-12-17T20:53:59.511876
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' ve done, of course, is we ' ve just expanded this further. so now we ' ve got a still taller box. and the liquid is going to be a little lower because some of it has evaporated, formed the gas phase. so here ' s xb at three. here ' s yb at three, here ' s our gas phase. now we could decrease even further. and this is the sort of thing that you maybe can ' t do in real life. but i can do on a blackboard. i ' m going to give myself more room on this curve, to finish this illustration. there. beautiful. so now we can lower a little bit further, and what i want to illustrate is, if we keep going down, eventually we get to a pressure where now if we look over in the gas phase, we ' re at the same pressure, mole fraction that we had originally in the liquid phase. so let ' s make four even lower pressure. what does that mean? what it means is, we ' re running out of liquid. so what ' s supposed to happen is a is the more volatile component. so as we start opening up some room for gas to form, you get more of a in the gas phase. but of course, and the liquid is richer in b. but of course, eventually you run out of liquid. you make the box pretty big, and you run out, or you have the very last drop of liquid. so what ' s the mole fraction of b in the gas phase? it has to be the same as what it started in in the liquid phase. because after all the total number of moles of a and b hasn ' t changed any. so if you take them all from the liquid and put them all up into the gas phase, it must be the same. so yb of four. once you just have the last drop. so then yb of four is basically equal to xb of one. because everything ' s now up in the gas phase. so in principle, there ' s still a tiny, tiny bit of xb at pressure four. well, we could keep lowering the pressure. we could make the box a little bigger. then the very last of the liquid is going to be gone. and what ' ll happen then is, we ' re all here. there ' s no more liquid. we ' re not going down on the coexistence curve any more. we don ' t have a liquid gas
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subdomain_quantum_field_theory
| 0.585363
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.512770
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going to be gone. and what ' ll happen then is, we ' re all here. there ' s no more liquid. we ' re not going down on the coexistence curve any more. we don ' t have a liquid gas coexistence any more. we just have a gas phase. of course, we can continue to lower the pressure. and then what we ' re doing is just going down here. so there ' s five. and five is the same as this only bigger. and so forth. ok, any questions about how this works? it ' s really important to just gain facility in reading these things and seeing, ok, what is it that this is telling you. and you can see it ' s not complicated to do it, but it takes a little bit of practice. ok. now, of course, we could do exactly the same thing starting from the gas phase. and raising the pressure. and although you may anticipate that it ' s kind of pedantic, i really do want to illustrate something by it. so let me just imagine that we ' re going to do that. let ' s start all in the gas phase. up here ' s the liquid. pa star, pb star. and now let ' s start somewhere here. so we ' re down somewhere in the gas phase with some composition. so it ' s the same story, except now we ' re starting here. it ' s all gas. and we ' re going to start squeezing. we ' re increasing the pressure. and eventually here ' s one, will reach two, so of course here ' s our yb. we started with all gas, no liquid. so this is yb of one. it ' s the same as yb of two, i ' m just raising the pressure enough to just reach the coexistence curve. and of course, out here tells us xb of two, right? so what is it saying? we ' ve squeezed and started to form some liquid. and the liquid is richer in component b. maybe it ' s ethanol water again. and we squeeze, and now we ' ve got more water in the liquid phase than in the gas phase. because water ' s the less volatile component. it ' s what ' s going to condense first. so the liquid is rich in the less volatile of the components. now, obviously, we can continue in doing exactly the reverse of what i showed you. but all i want to
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subdomain_quantum_gravity
| 0.592963
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.513597
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component. it ' s what ' s going to condense first. so the liquid is rich in the less volatile of the components. now, obviously, we can continue in doing exactly the reverse of what i showed you. but all i want to really illustrate is, this is a strategy for purification of the less volatile component. once you ' ve done this, well now you ' ve got some liquid. now you could collect that liquid in a separate vessel. so let ' s collect the liquid mixture with xb of two. so it ' s got some mole fraction of b. so we ' ve purified that. but now we ' re going to start, we ' ve got pure liquid. now let ' s make the vessel big. so it all goes into the gas phase. then lower p. all gas. so we start with yb of three, which equals xb of two. in other words, it ' s the same mole fraction. so let ' s reconstruct that. so here ' s p of two. and now we ' re going to go to some new pressure. and the point is, now we ' re going to start, since the mole fraction in the gas phase that we ' re starting from is the same number as this was. so it ' s around here somewhere. that ' s yb of three equals xb of two. and we ' re down here. in other words, all we ' ve done is make the container big enough so the pressure ' s low and it ' s all in the gas phase. that ' s all we have, is the gas. but the composition is whatever the composition is that we extracted here from the liquid. so this xb, which is the liquid mole fraction, is now yb, the gas mole fraction. of course, the pressure is different. lower than it was before. great. now let ' s increase. so here ' s three. and now let ' s increase the pressure to four. and of course what happens, now we ' ve got coexistence. so here ' s liquid. here ' s gas. so, now we ' re over here again. there ' s xb at pressure four. pure still in component b. we can repeat the same procedure. collect it. all liquid, put it in a new vessel. expand it, lower the pressure, all goes back into the gas phase. do it all again. and the point is, what you ' re doing is walking along
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subdomain_quantum_thermodynamics
| 0.585909
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
| 7
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2025-12-17T20:53:59.514448
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the same procedure. collect it. all liquid, put it in a new vessel. expand it, lower the pressure, all goes back into the gas phase. do it all again. and the point is, what you ' re doing is walking along here. here to here. then you start down here, and go from here to here. from here to here. and you can purify. now, of course, the optimal procedure, you have to think a little bit. because if you really do precisely what i said, you ' re going to have a mighty little bit of material each time you do that. so yes it ' ll be the little bit you ' ve gotten at the end is going to be really pure, but there ' s not a whole lot of it. because, remember, what we said is let ' s raise the pressure until we just start being on the coexistence curve. so we ' ve still got mostly gas. little bit of liquid. now, i could raise the pressure a bit higher. so that in the interest of having more of the liquid, when i do that, though, the liquid that i have at this higher pressure won ' t be as enriched as it was down here. now, i could still do this procedure. i could just do more of them. so it takes a little bit of judiciousness to figure out how to optimize that. in the end, though, you can continue to walk your way down through these coexistence curves and purify repeatedly the component b, the less volatile of them, and end up with some amount of it. and there ' ll be some balance between the amount that you feel like you need to end up with and how pure you need it to be. any questions about how this works? so purification of less volatile components. now, how much of each of these quantities in each of these phases? so, pertinent to this discussion, of course we need to know that. if you want to try to optimize a procedure like that, of course it ' s going to be crucial to be able to understand and calculate for any pressure that you decide to raise to, just how many moles do you have in each of the phases? so at the end of the day, you can figure out, ok, now when i reach a certain degree of purification, here ' s how much of the stuff i end up with. well, that turns out to be reasonably straightforward to
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subdomain_quantum_thermodynamics
| 0.551395
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.515282
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phases? so at the end of the day, you can figure out, ok, now when i reach a certain degree of purification, here ' s how much of the stuff i end up with. well, that turns out to be reasonably straightforward to do. and so what i ' ll go through is a simple mathematical derivation. and it turns out that it allows you to just read right off the diagram how much of each material you ' re going to end up with. so, here ' s what happens. this is something called the lever rule. how much of each component is there in each phase? so let ' s consider a case like this. let me draw yet once again, just to get the numbering consistent. with how we ' ll treat this. so we ' re going to start here. and i want to draw it right in the middle, so i ' ve got plenty of room. and we ' re going to go up to some pressure. and somewhere out there, now i can go to my coexistence curves. liquid. and gas. and i can read off my values. so this is the liquid xb. so i ' m going to go up to some point two, here ' s xb of two. here ' s yb of two. great. now let ' s get these written in. so let ' s just define terms a little bit. na, nb. or just our total number of moles. ng and n liquid, of course, total number of moles. in the gas and liquid phases. so let ' s just do the calculation for each of these two cases. we ' ll start with one. that ' s the easier case. because then we have only the gas. so at one, all gas. it says pure gas in the notes, but of course that isn ' t the pure gas. it ' s the mixture of the two components. so. how many moles of a? well it ' s the mole fraction of a in the gas. times the total number of moles in the gas. let me put one in here. just to be clear. and since we have all gas, the number of moles in the gas is just the total number of moles. so this is just ya at one times n total. let ' s just write that in. and of course n total is equal to na plus nb. so now let ' s look at condition two. now we have to look a little more carefully
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subdomain_quantum_optics
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
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2025-12-17T20:53:59.516109
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this is just ya at one times n total. let ' s just write that in. and of course n total is equal to na plus nb. so now let ' s look at condition two. now we have to look a little more carefully. because we have a liquid gas mixture. so na is equal to ya at pressure two. times the number of moles of gas at pressure two. plus xa, at pressure two, times the number of moles of liquid at pressure two. now, of course, these things have to be equal. the total number of moles of a didn ' t change, right? so those are equal. then ya of two times ng of two. plus xa of two times n liquid of two, that ' s equal to ya of one times n total. which is of course equal to ya of one times n gas at two plus n liquid at two. i suppose i could be, add that equality. of course, it ' s an obvious one. but let me do it anyway. the total number of moles is equal to na plus nb. but it ' s also equal to n liquid plus n gas. and that ' s all i ' m taking advantage of here. and now i ' m just going to rearrange the terms. so i ' m going to write ya at one minus ya at two, times ng at two, is equal to, and i ' m going to take the other terms, the xa term. xa of two minus ya of one times n liquid at two. so i ' ve just rearranged the terms. and i ' ve done that because now, i think i omitted something here. ya of one times ng. no, i forgot a bracket, is what i did. ya of one there. and i did this because now i want to do is look at the ratio of liquid to gas at pressure two. so, ratio of i ' ll put it gas to liquid, that ' s ng of two over n liquid at two. and that ' s just equal to xa of two minus ya at one minus ya at one minus ya at two. so what does it mean? it ' s the ratio of these lever arms. that ' s what it ' s telling me. i can look, so i raise the pressure up to two. and so here ' s xb at two, here ' s yb at two. and i ' m here somewhere. and this little amount and this
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subdomain_quantum_optics
| 0.549888
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HuggingFaceFW/fineweb-edu
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<urn:uuid:246f9a12-fd35-40fa-8257-b07bf8d92857>
| 10
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2025-12-17T20:53:59.516918
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it ' s telling me. i can look, so i raise the pressure up to two. and so here ' s xb at two, here ' s yb at two. and i ' m here somewhere. and this little amount and this little amount, that ' s that difference. and it ' s just telling me that ratio of those arms is the ratio of the total number of moles of gas to liquid. and that ' s great. because now when i go back to the problem that we were just looking at, where i say, well i ' m going to purify the less volatile component by raising the pressure until i ' m at coexistence starting in the gas phase. raise the pressure, i ' ve got some liquid. but i also want some finite amount of liquid. but i don ' t want to just, when i get the very, very first drop of liquid now collected, of course it ' s enriched in the less volatile component. but there may be a minuscule amount, right? so i ' ll raise the pressure a bit more. i ' ll go up in pressure. and now, of course, when i do that the amount of enrichment of the liquid isn ' t as big as it was if i just raised it up enough to barely have any liquid. then i ' d be out here. but i ' ve got more material in the liquid phase to collect. and that ' s what this allows me to calculate. is how much do i get in the end. so it ' s very handy. you can also see, if i go all the way to the limit where the mole fraction in the liquid at the end is equal to what it was in the gas when i started, what that says is that there ' s no more gas left any more. in other words, these two things are equal. if i go all the way to the point where i ' ve got all the, this is the amount i started with, in the pure gas phase, now i keep raising it all the way. until i ' ve got the same mole fraction in the liquid. of course, we know what that really means. that means that i ' ve gone all the way from pure gas to pure liquid. and the mole fraction in that case has to be the same. and what this is just telling us mathematically is, when that happens this is zero. that means i don ' t have any gas left. yeah. professor : no. because, so it
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mole fraction in that case has to be the same. and what this is just telling us mathematically is, when that happens this is zero. that means i don ' t have any gas left. yeah. professor : no. because, so it ' s the mole fraction in the gas phase. but you ' ve started with some amount that it ' s only going to go down from there. professor : yeah. yeah. any other questions? ok. well, now what i want to do is just put up a slightly different kind of diagram, but different in an important way. namely, instead of showing the mole fractions as a function of the pressure. and i haven ' t written it in, but all of these are at constant temperature, right? i ' ve assumed the temperature is constant in all these things. now let ' s consider the other possibility, the other simple possibility, which is, let ' s hold the pressure constant and vary the temperature. of course, you know in the lab, that ' s usually what ' s easiest to do. now, unfortunately, the arithmetic gets more complicated. it ' s not monumentally complicated, but here in this case, where you have one linear relationship, which is very convenient. from raoult ' s law. and then you have one non - linear relationship there for the mole fraction of the gas. in the case of temperature, they ' re both, neither one is linear. nevertheless, we can just sketch what the diagram looks like. and of course it ' s very useful to do that, and see how to read off it. and i should say the derivation of the curves isn ' t particularly complicated. it ' s not particularly more complicated than what i think you saw last time to derive this. there ' s no complicated math involved. but the point is, the derivation doesn ' t yield a linear relationship for either the gas or the liquid part of the coexistence curve. ok, so we ' re going to look at temperature and mole fraction phase diagrams. again, a little more complicated mathematically but more practical in real use. and this is t. and here is the, sort of, form that these things take. so again, neither one is linear. up here, now, of course if you raise the temperatures, that ' s where you end up with gas. if you lower the temperature, you condense and get the liquid. so, this is ta star. tb star. so now i want to stick with a as
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course if you raise the temperatures, that ' s where you end up with gas. if you lower the temperature, you condense and get the liquid. so, this is ta star. tb star. so now i want to stick with a as the more volatile component. at constant temperature, that meant that pa star is bigger than pb star. in other words, the vapor pressure over pure liquid a is higher than the vapor pressure over pure liquid b. similarly, now i ' ve got constant pressure and really what i ' m looking at, let ' s say i ' m at the limit where i ' ve got the pure liquid. or the pure a. and now i ' m going to, let ' s say, raise the temperature until i ' m at the liquid - gas equilibrium. that ' s just the boiling point. so if a is the more volatile component, it has the lower boiling point. and that ' s what this reflects. so higher pb star a corresponds to lower ta star a. which is just the boiling point of pure a. so, this is called the bubble line. that ' s called the dew line. all that means is, let ' s say i ' m at high temperature. i ' ve got all gas. right no coexistence, no liquid yet. and i start to cool things off. just to where i just barely start to get liquid. what you see that as is, dew starts forming. a little bit of condensation. if you ' re outside, it means on the grass a little bit of dew is forming. similarly, if i start at low temperature, all liquid now i start raising the temperature until i just start to boil. i just start to see the first bubbles forming. and so that ' s why these things have those names. so now let ' s just follow along what happens when i do the same sort of thing that i illustrated there. i want to start at one point in this phase diagram. and then start changing the conditions. so let ' s start here. so i ' m going to start all in the liquid phase. that is, the temperature is low. here ' s xb. and my original temperature. now i ' m going to raise it. so if i raise it a little bit, i reach a point at which i first start to boil. start to find some gas above the liquid. and if i look right here, that ' ll be my composition. let me raise it a little farther
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if i raise it a little bit, i reach a point at which i first start to boil. start to find some gas above the liquid. and if i look right here, that ' ll be my composition. let me raise it a little farther, now that we ' ve already seen the lever rule and so forth. i ' ll raise it up to here. and that means that out here, i suppose i should do here. so, here is the liquid mole fraction at temperature two. xb at temperature two. this is yb at temperature two. the gas mole fraction. so as you should expect, what ' s going to happen here is that the gas, this is going to be lower in b. a, that means that the mole fraction of a must be higher in the gas phase. that ' s one minus yb. so xa is one minus - - ya, which is one minus yb higher in gas phase. than xa, which is one minus xb. in other words, the less volatile component is enriched up in the gas phase. now, what does that mean? that means i could follow the same sort of procedure that i indicated before when we looked at the pressure mole fraction phase diagram. namely, i could do this and now i could take the gas phase. which has less of b. it has more of a. and i can collect it. and then i can reduce the temperature. so it liquefies. so i can condense it, in other words. so now i ' m going to start with, let ' s say i lower the temperature enough so i ' ve got basically pure liquid. but its composition is the same as the gas here. because of course that ' s what that liquid is formed from. i collected the gas and separated it. so now i could start all over again. except instead of being here, i ' ll be down here. and then i can raise the temperature again. to some place where i choose. i could choose here, and go all the way to hear. a great amount of enrichment. but i know from the lever rule that if i do that, i ' m going to have precious little material over here. so i might prefer to raise the temperature a little more. still get a substantial amount of enrichment. and now i ' ve got, in the gas phase, i ' ll further enriched in component a. and again i can collect the gas. condense it. now i ' m out here somewhere
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more. still get a substantial amount of enrichment. and now i ' ve got, in the gas phase, i ' ll further enriched in component a. and again i can collect the gas. condense it. now i ' m out here somewhere, i ' ve got all liquid and i ' ll raise the temperature again. and i can again keep walking my way over. and that ' s what happens during an ordinary distillation. each step of the distillation walks along in the phase diagram at some selected point. and of course what you ' re doing is, you ' re always condensing the gas. and starting with fresh liquid that now is enriched in more volatile of the components. so of course if you ' re really purifying, say, ethanol from an ethanol water mixture, that ' s how you do it. ethanol is the more volatile component. so a still is set up. it will boil the stuff and collect the gas and and condense it. and boil it again, and so forth. and the whole thing can be set up in a very efficient way. so you have essentially continuous distillation. where you have a whole sequence of collection and condensation and reheating and so forth events. so then, in a practical way, it ' s possible to walk quite far along the distillation, the coexistence curve, and distill to really a high degree of purification. any questions about how that works? ok. i ' ll leave till next time the discussion of the chemical potentials. but what we ' ll do, just to foreshadow a little bit, what i ' ll do at the beginning of the next lecture is what ' s at the end of your notes here. which is just to say ok, now if we look at raoult ' s law, it ' s straightforward to say what is the chemical potential for each of the substances in the liquid and the gas phase. of course, it has to be equal. given that, that ' s for an ideal solution. we can gain some insight from that. and then look at real solutions, non - ideal solutions, and understand a lot of their behavior as well. just from starting from our understanding of what the chemical potential does even in a simple ideal mixture. so we ' ll look at the chemical potentials. and then we ' ll look at non - ideal solution mixtures next time. see you then.
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topics covered : encapsulation, inheritance, shadowing instructor : prof. eric grimson, prof. john guttag operator : the following content is provided under a creative commons license. your support will help mit opencourseware continue to offer high quality educational resources for free. to make a donation or view additional materials from hundreds of mit courses, visit mit opencourseware at ocw. mit. edu. professor : last lecture we were talking about classes, and object - oriented programming, and we ' re going to come back to it today. i ' m going to remind you, we were talking about it because we suggested it is a really powerful way of structuring systems, and that ' s really why we want to use it, it ' s a very common way of structuring systems. so today i ' m going to pick up on a bunch of more nuanced, or more complex if you like, ways of leveraging the power of classes. but we ' re going to see a bunch of examples that are going to give us a sense. i ' m going to talk about inheritance, we ' re going to talk about shadowing, we ' re going to talk about iterators. but before get to it, i want to start by just highlighting, sort of, what was the point of classes? so i ' ll remind you. a class, i said, was basically a template for an abstract data type. and this was really to drive home this idea of modularity. i want the ability to say, i ' ve got a set of things that naturally belong together, i ' m going to cluster them together, i want to treat it like it ' s a primitive, i want to treat it like it ' s a float or an int or a string. is this going to be a point or a segment or something different like that. so it ' s really a way, as i said, of just trying to cluster data together. and this is a notion of modularity slash abstraction where i ' m treating them as primitives. but the second thing we talked about is that we also have a set of methods, using the special name method because we ' re talking classes. but basically functions that are designed to deal with this data structure. we ' re trying to group those together as well. so we cluster data and methods. second key thing we said was, in the ideal case, which unfortunately python isn ' t, but we ' ll come back
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to deal with this data structure. we ' re trying to group those together as well. so we cluster data and methods. second key thing we said was, in the ideal case, which unfortunately python isn ' t, but we ' ll come back to that, in the ideal case, we would have data hiding, and by data hiding, which is sort of a version of encapsulation, what we meant was that you could only get to the internal pieces of that data structure through a proscribed method. proscribed meaning it ' s something i set up. so data hiding saying, you would only access the parts through a method. and as we said, unfortunately python does not enforce this. meaning that i could create one of these data structures, ideally i ' d have a method, that i ' m going to see some examples of that i used to get the parts out, unfortunately in python you could take the name the instance dot some internal variable you ' ll get it back. it is exposed. and this is actually just not a good idea. so i suggested in my very bad humor, that you practice computational hygiene and you only use appropriate methods to get the parts out. ok didn ' t laugh the joke last time, you ' re not going to laugh at it this time, i don ' t blame you. all right, and then the last piece of this is that we said the class is a template. when we call that class, it makes an instance. so class is used to make instances, meaning particular versions, of that structure, and we said inside the instances we have a set of attributes. internal variables, methods, that are going to belong to that structure. ok, so with that in mind, here ' s what i want to do. i ' m going to show you a set of examples, and i want to warn you ahead of time, the code handout today is a little longer than normal because we want to build essentially an extended example of a sequence of examples of classes. we ' re going to see the idea, of which we ' re gonna talk about, of inheritance or hierarchy, in which we can have classes that are specializations of other classes. we ' re gonna see how we can inherit methods, how we can shadow methods, how we can use methods in a variety of ways. so this is a way of suggesting you may find it more convenient to put notes on the code handout rather than in your own notes. do whatever you like, but
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we can shadow methods, how we can use methods in a variety of ways. so this is a way of suggesting you may find it more convenient to put notes on the code handout rather than in your own notes. do whatever you like, but i just wanted to alert you, we ' re going to go through a little more code than normal. so, the little environment i ' m going to build is an environment of people. i ' ll build a simple little simulation of people. so i ' m going to start off with the first class, which i ' ve got up on the screen, and it ' s on your handout as well, which is i ' m going to build an instance, or a class rather, of persons. i ' m going to draw a diagram, which i ' m gonna try and see if i can do well, over here, of the different objects we ' re going to have. so i ' ve got, a class, and by the way a class is an object. instances are also objects, but classes are objects. we ' re gonna see why we want that in a second. because i ' m gonna build an object, sorry a class, called a person. now, let ' s walk through some of the pieces here. the first one is, there ' s something a little different. remember last time we had that keyword class and then a name, that name, in this case, person says this is the name for the class, and then we would have just had the semicolon and a bunch of internal things. here i ' ve got something in parens, and i want to stress this is not a variable. all right, this is not a def, this is a class. i ' m going to come back to it, but what this is basically saying is that the person class is going to inherit from another class, which in this case is just the built - in python object class. hold on to that thought, it ' s going to make more sense when we look at a little more interesting example, but i want to highlight that. all right now, if we do this, as i said before, we can create a version of a person, let me just call it per, person. ok? and what we said last time is, when we wanted to create an instance inside of this class definition, we ' ve got one of those built - in things called init. i ' m gonna again remind you, some of
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person. ok? and what we said last time is, when we wanted to create an instance inside of this class definition, we ' ve got one of those built - in things called init. i ' m gonna again remind you, some of the methods we have, underbar underbar init is going to be the thing that creates the instance. actually slightly misspeaking, actually python creates the instance, but it ' s one thing that fills it in. so in this case, i ' m going to give it 2 arguments : frank foobar now, you might have said, wait a minute, init here has 3 arguments : self, family name, and first name. so again, just to remind you, what we said happens here is that when i call this class, person, i ' m creating an instance. we ' ll draw a little instance diagram down here. i ' m going to give it the name per. and i should have said inside of person, we ' ve got a set of things. we ' ve got our underbar underbar init, we ' ve got, what else do i have up there? family name. and a bunch of other methods, down to say. what happens inside of python is, when we called the class definition, person, it creates an instance, there it is. think of it as a pointer to a spot in memory, and then what we do is, we call, or find, that init method, up here, and we apply it. and the first argument self, points to the instance. so this object here is what self looks at. now you can see what init ' s going to do. it says, oh, inside of self, which is pointing to here, let me bind a variable, which was, can read that very carefully, it ' s family underbar name, to the value i passed in, which was 4. same thing with first name. ok, so the reason i ' m stressing this is, self we do not supply explicitly, it is supplied as pointing to the instance, it ' s giving us that piece of memory. and that is what then gets created. so here ' s, now, the instance for per. ok, and i put a little label on there, i ' m going to call that an isalink, because it is an instance of that class. god bless you. all right, so once we got this, let ' s look at what we can
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and i put a little label on there, i ' m going to call that an isalink, because it is an instance of that class. god bless you. all right, so once we got this, let ' s look at what we can do with person. that ' s why i built person here. and as i said, i ' ve already bound basically, those two pieces. if i want to get a value out, i can give person, or per, rather, this instance, a messaging. in this case i want to get family, what did i say, family name out, now, again i want to stress, what is happening here? per is an instance, it ' s this thing here. when i say per dot family name, i ' m sending it a message, in essence what that does is, it says, from here it ' s going to go up the chain to this class object and find the appropriate method, which was family name. it is then going to apply that to self, which points to this instance. and that allows it, therefore, is you can see on the code, to look up under self, what ' s the binding for family name, and print it back up. so self is always going to point to the instance i want and i can use it. ok what else do we have in here? we can get the first name, that ' s not particularly interesting. we ' ve got 2 other special methods : that ' s cmp and str. all right, cmp is our comparison method. and since i, i was about to say i blew it last time, i misspoke last time, a wonderful phrase that politicians like to use, i misspoke last time. let me clarify again what cmp will do. underbar underbar cmp is going to be the method you ' re going to use to compare two instances of an object. now, let ' s back up for second. if i wanted to test equality, in fact i could use underbar underbar eq, under under. it ' s natural to think about an equality tester as returning a boolean, it ' s either gonna be true or false, because something ' s either equal to or not. in many languages, comparisons also return booleans, which is why i went down this slippery slope. for many languages, either it ' s greater than or it ' s not. but python is different. python use cmp, in fact
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. in many languages, comparisons also return booleans, which is why i went down this slippery slope. for many languages, either it ' s greater than or it ' s not. but python is different. python use cmp, in fact it has a built in cmp, which is what we ' re relying on here. where am i, right there. and what cmp returns is 1 of 3 values. given 2 objects, it says if the first one is less than the second one, it returns - 1, if it ' s equal it returns 0, if it ' s greater than, it returns 1. so it allows you this broader range of comparisons. and if you think about it, cmp, you could apply on integers, you could apply it on floats, apply it on strings. so it ' s overloaded, it has the ability to do all of those. and in this case what we ' re saying is, given 2 objects, let ' s create a tuple of the first, sorry, family and first name of ourselves, and other is another object, family and first name of that, and then just use cmp to compare them. all right, so it ' s going to use the base pieces. ok, so it gives me a way of doing comparisons. and str we saw last time as well, this is cmp does comparison, and str is our printed representation. ok. so what we ' ve got now, is a simple little class. we ' ve also got two methods there. i want to look at them, we ' re gonna come back to them, but they start to highlight things we can do with our classes. so i ' ve built one simple version of it here, which is per. and notice i ' ve got another method, right up here, called say. and say takes two arguments, for the moment the second argument, or the first argument ' s, not going to make a lot of sense, but say takes two arguments besides itself. it ' s going to take another object to which it ' s saying something and the thing to say. since i only have one object here, i ' m going to have person talk to himself. you may have met a few other undergraduates who have this behavior. i ' ll have him talk to himself and say, just some random message the faculty members occasionally worry about. ok, what does this thing do? now you ' re going to see some of the power of this
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undergraduates who have this behavior. i ' ll have him talk to himself and say, just some random message the faculty members occasionally worry about. ok, what does this thing do? now you ' re going to see some of the power of this. again, remember, i ' m down here, i ' m sending this the message say, it ' s going to go up the chain to find the say message in person. and what does say do, it says given another object and some string, it ' s going to return, oh, and interesting things, part of which you can ' t see on the screen. first what it does, is it gets first name of self. remember self is pointing to this instance, so it ' s simply looks up that binding, which is frank. it ' s going to create a string in which it adds to that the family name of self, and then another thing that says to, and then ah, i ' m now going to send a message to the other object, saying give me your first name. going to add that to the second piece, and you can see in this case it happens to be the same first and family name. and then at the end of it, which you can ' t see here but you can see in your handout, i just append the whole string, so it spits it out. what ' s the point of this, other than i can get it to say things? notice, i can now reference values of the instance. but i can also get values of other instances, by sending in a message. and that ' s why we have that form right there. and then it glued all together. if you think about this for a second, you might say, wait a minute, actually you might have said wait a minute a while ago, why am i just using the variable name there in the function over here? well in fact, i could ' ve used the function here, first name open close, right? it would have done the same thing. but because i know i ' m inside the instance, it ' s perfectly reasonable to just look up the value. ok, i could have, although i don ' t want you to do it, have done the same thing there and used underbar, sorry, first name underbar, sorry, first underbar name, but that ' s really breaking this contract that i want to happen. i should send the message to get the method back out. so again the standard
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there and used underbar, sorry, first name underbar, sorry, first underbar name, but that ' s really breaking this contract that i want to happen. i should send the message to get the method back out. so again the standard practices is if you know you ' re inside the object, you can just access the values. if you ' re doing it with any other objects, send it a message to get it out. ok, now, that gives you an ability to say, let ' s look at one more example here, and then we ' re going to start building our hierarchy, which is, that this person can also sing. and we ' ve got a little sing method here. and notice what it does, it ' s going to sing to somebody, i guess you ' re part of the chorallaries. you ' re going to sing something, and notice what it does, it ' s simply going to use its say method, but add at the end of whatever ' s being said, just tra la la at the end. so this is now an example of a method using another method. why would you want that? it ' s nice modularly. i have one method that ' s doing saying, i have another method that ' s just building on it. so if i have is person sing to themselves, not a highly recommended activity, it would help if i had it sing to itself, not sing to sing, sorry about that. notice what it does. looks like exactly like a say method, except it ' s got tra la la at the end. don ' t worry i ' m not going to sing to you. i ' ll simply say the words. power of this, other than the silly examples. you see how i can access variables of the instance, how i can access variables of other instances, going to come back to that, and how i can use versions of my own methods to implement other methods. in this case sing is using say as part of what it wants to get out. ok, so we got a simple little example. now, let ' s start adding some other pieces to this. ok, and what do i want to add. find my spot here. ok, we ' re going to add an mit person. sorry, machine is - - do this, let ' s go down. ok so i ' m going to add an mit person. look at the code for second. aha! notice what this says. mit person
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2025-12-17T20:53:59.558453
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to add an mit person. sorry, machine is - - do this, let ' s go down. ok so i ' m going to add an mit person. look at the code for second. aha! notice what this says. mit person says it inherits from person. that is, that ' s the first thing in parens up there. it says, you know, class of mit person is person. what that is saying is, that this is a specialization of the person class. or another way of saying it is, we have a super class, in this case it ' s person. and we have a subclass, in this case its mit person. and we ' re going to walk through some examples, but what it says is that that subclass of mit person can inherit the attributes of the person class. can inherit the methods, it can inherit variables. ok, what does mit person do? well, here ' s 1 of the new things it does. it has a local variable called next id num, which is initially set to 0. see that up there. and then it ' s got some methods, it ' s got an init method, a get id method, a few other things. ok, let ' s run this. in particular, i go back down to this one. let me just uncomment this and do it here. assuming my machine will do what i want it to do, which it really doesn ' t seem to want to do today. try one more time. thank you, yep. still not doing it for me, john. ok, we type it. no idea what python doesn ' t like me today, but it doesn ' t. so we ' re gonna define p 1, i ' ve lost my keyboard, indeed i have. try one more time. p 1 mit person, see how fast i can type here - - ok, now, let ' s look at what the code does, because again it ' s going to highlight some things. i called mit person, push this up slightly, it ' s going to create an instance down here, i called p 1. and when i would do that, i ' m gonna initialize it. so i ' ve got, right up here, an initializer, init for mit person, takes in the family name and the first name. notice what it does. huh. it says, if i ' m sitting here at mit person, i ' m going to go up and
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subdomain_quantum_field_theory
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2025-12-17T20:53:59.559261
|
here, an initializer, init for mit person, takes in the family name and the first name. notice what it does. huh. it says, if i ' m sitting here at mit person, i ' m going to go up and inherit from person its init function and call it. and what am i calling it on? i ' m calling it on self, which is pointing to this object, so i ' ve still got it, and then i ' m then going to apply the base initialization. and that does exactly what you ' d expect, which is just going to create a binding for family name down here. as well as some other things. so this is an example of inheritance. mit person inherits the init method from person, can get access to by simply referring to it, and i refer to it right there. and it ' s take the person class, get its init and apply it to my instance plus those things. so i ' m just using the same piece of code notice the second thing it does. it says inside of self, i ' m going to bind the local variable id name to the value of next id name in mit person. self is down here, id num, sorry, not id name. i ' m going to bind that to the value that i find my going up to here, which is 0, and having done that, i simply increment that value. ok? so what has this done? it says i now have captured in the class, a local variable that i can keep track of. and when i use it, every time i generate an example, let me build another one. i make p 2 another mit person. ok, i can do things like saying, what is the id number for each of these. first one is 0, second one is 1, which makes sense, right? i ' m just incrementing a global variable. now, things i want you to see about this. now that i ' ve got a beginning of a hierarchy, i have this notion of inheritance. i can ask a function inside one class to use a function from a class that it can reach by going up the chain. i just did it there. i can ask it to go get values of variables, right, so that looks good. what else do we have in person or mit person? well, we can get the id number, we just did. we have a thing to do with this string. notice it ' s
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subdomain_quantum_field_theory
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2025-12-17T20:53:59.560742
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get values of variables, right, so that looks good. what else do we have in person or mit person? well, we can get the id number, we just did. we have a thing to do with this string. notice it ' s going to print out something a little different. in fact, there ' s a kind of funky form there. which just says, if i want to print it out, i ' m gonna create, what this says to do is, i ' m gonna create an output template that has that structure to it, but where i see that percent s i ' m going to substitute this value for the first one, that value for the second. so if i say, what is p 1? it says ok, mit person fred smith. on the other hand, if i said, what is per, which is that thing i build earlier, it had a different string method, which is just print out person, those pieces. all right, one last piece to this and we ' re going to add to it. suppose i want fred to say something. say something to jane. ok, he said it. where ' s the say method? ok, fred is an instance of an mit person. where ' s the say method? well, there isn ' t one there, but again, that ' s where the hierarchy comes in. fred is this object here, i ' m sending it the message say. that turns into going up the chain to this object, which is the class object, and saying find a say method and apply it to that instance. fudge - knuckle, it ain ' t here. don ' t worry about it, because it says if i can ' t find one there, i ' m going to go up the chain to this method, sorry to this class, and look for a method there. which there was one, i have a say method. it ' s going to use that say method. apply to it. well, you might say, ok, what happens if it isn ' t there? well, that ' s where, remember i defined person to be an instance of an object, it will go up the chain one last time to the base object in python to see is there a method there or not. probably isn ' t a say method for an object, so at that point it ' s going to raise an exception or throw an error. but now you again see this idea that the inheritance lets you capture methods. now you might
|
subdomain_quantum_gravity
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2025-12-17T20:53:59.561703
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there or not. probably isn ' t a say method for an object, so at that point it ' s going to raise an exception or throw an error. but now you again see this idea that the inheritance lets you capture methods. now you might say, why not just put a say method inside of mit person? well, if you wanted it to do something different, that would be the right thing to do. but the whole notion here ' s that i ' m capturing modularity, i ' ve got base methods up in my base class. if i just want to use them i ' m just going to inherit them by following that chain, if you like, basically up the track. ok, so we ' ve got an mit person, we can use that. let ' s add a little bit more to our hierarchy here. i ' m going to create, if i can do this right, a specialization of an mit person, which is an undergraduate. a special kind of mit person. all right, so if i go back up here, even though my thing is not going to let me do it, let ' s build an undergraduate. ok, there ' s the class definition for an undergrad. we ' re just starting to see some of the pieces, right, so in an undergraduate, where am i here, an undergraduate. ok, it ' s also got an initialization function. so if i call undergrad, i ' m gonna make an undergrad here, again let me go back down here, line ug 2 it ' s making undergrad, jane doe. now, what happens when i do the initialization here? notice what goes on. it simply calls the person initialization method. all right, so i ' m down here. i ' m going to call the person initialization method, what did do? sorry, the mit person method, it calls the person method. just walking up the chain, that ' s going to do exactly what i did with all the other ones, so i now have a family name and a first name. so i can, for example, say family name and get it back out. all right? and then, other things that i can do, well i can set what year the person ' s in, i can figure out what year they ' re in, there ' s this unfortunate overflow error if you ' ve hung around too long, but that ' s not going to happen to you. and i ' ve now got a say method
|
subdomain_quantum_field_theory
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.562585
|
in, i can figure out what year they ' re in, there ' s this unfortunate overflow error if you ' ve hung around too long, but that ' s not going to happen to you. and i ' ve now got a say method here, so let ' s look what happens if i ask the undergraduate to say something. ok, it ' s not a realistic dialogue i know, but, what did this method do? i asked this object to do a say. and notice what it does. it simply passes it back up to mit person. there ' s that inheritance again. it ' s saying, i ' m going to have my base say method say something. i ' m going to say it to a person, but all i ' m going to do because undergraduates in my experience, at least, are always very polite, i ' m going to put " excuse me but " at the front of it. ok, what am i trying to show you here? i know the jokes are awful, but what am i trying to show you here? that i can simply pass up the chain to get it. in fact, what method does the final say here? what class does it come from? person class, yes, thank you. it goes all the way up to person, right, because mit person didn ' t have a say. so i can simply walk up the chain until i find the method i want to have. now this is an example of shadowing. not a great example, but it ' s a beginning example of shadowing, in that this same method for an undergraduate, shadows the base say method, it happens to call it, but it changes it. it puts " excuse me but " at the front, before it goes on to do something. now again, i could have decided here to actually copy what the original say method did, stitch all the other things together. but again, that loses my modularity. i ' d really to only have to change it in one place. so by putting my say method up in person, i can add these nuances to it, and it lets me have something that has that variation. if i decide i want to change what say does, i only have to change it in one place. it is in the person class definition, and everything else will follow through for free. ok, so now i ' ve got an undergrad, right? let ' s look at a couple of variations of what happens here. so first of all
|
subdomain_quantum_computing
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.563458
|
. it is in the person class definition, and everything else will follow through for free. ok, so now i ' ve got an undergrad, right? let ' s look at a couple of variations of what happens here. so first of all, i can - - yes? professor 2 : shadowing here is often sometimes called overriding. professor : yes, thank you, because i ' m going to do a pure example of shadowing in a second, john right. also called overriding. part of the reason i like the phrase shadow is, if you think about it as looking at it from this direction, you see this version of init before you see the other ones, or you see that version of say, but it is overriding the base say example. ok, so i can say, what does p 1, sorry, yes, what does undergrad look like? and i said wait a minute, mit person, not undergrad, is that right? well, where ' s the str method? i didn ' t define one in undergrad, so it again tracks up the chain and finds the str method here, so it ' s ok undergrads are mit people most the time, so it ' s perfectly fine. ok, now, i have built into this also these cmp methods. so i ' ve got two examples. i ' ve got undergrad, or ug. and then i ' ve got poor old frank foobar back there, per person. so suppose i want to compare them? what do you think happens here? compare sounds weird, right, i compare an undergraduate to a person. i don ' t know what that ' s doing, some kind of weird psychological thing, but what do you think happens in terms of the code here if i run this. i know it ' s a little hard because you got a lot of code to look at. do i have a cmp method defined somewhere? yeah. so, it ' s hard to know what it ' s going to do, but let ' s look at it. hmm. now sometimes i type things and i got errors i don ' t expect, this one i did expect. so what happened here? well let ' s talk about what happens if i do that comparison i was doing, what was i doing? ug greater than per? what unwinds into is, i ' m going to send to ug, that instance, a cmp method. this is really going to
|
subdomain_quantum_field_theory
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.564293
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if i do that comparison i was doing, what was i doing? ug greater than per? what unwinds into is, i ' m going to send to ug, that instance, a cmp method. this is really going to become something like ug dot under under cmp under under applied to per. i think that ' s close. what does that do? it says starting in ug, i ' m going to look for the first cmp method i could find, which is actually sitting here. i had a cmp method in mit person. if you look at your code, what does it do? it looks up the id numbers to compare them. well the, ug has an id number because it was created along this chamber. remember per over here was just created as a person. it doesn ' t have an id number, so that ' s why it complaints. ok, happens if i do that? compare per to ug. how many people think i get an error? wow. how many people think i ' m going to get either true or false out of this? a few brave hands. why? can i ask you, please? why do you think i ' m going to get a, doesn ' t matter whether it ' s true or false, why am i going to have something work this time that didn ' t work last time? professor : yeah, exactly. and in case you didn ' t hear it, thank you, great answer, sorry, terrible throw. in this case i ' m using per, that ' s the first part, so it ' s not symmetric. it ' s gonna use per to do the look up. and as it was said there, per over here goes up and finds a cmp method here which it can apply. in that case, it simply looked at, remember, it took the tuples of first and last name which are both defined here, and did some comparison on that. so this is a way of again pointing out to you that the things are not always symmetric, and i have to be careful about where do i find the methods as i want to use them. ok? all right. let ' s add, i ' m gonna do two more classes here. let ' s add one more class, some people debate whether these are really people or not, but we ' re going to add a class called a professor. ok. now what am i doing? i ' m creating another version of class down here
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subdomain_quantum_cryptography
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.565087
|
let ' s add one more class, some people debate whether these are really people or not, but we ' re going to add a class called a professor. ok. now what am i doing? i ' m creating another version of class down here. which again is an instance, or a subclass, sorry, not an instance, a subclass of an mit person. i see that because i built it to be there. again i ' ve got an initialization that ' s going to call the person initialization, which we know is going to go up - - i keep saying that - - going to call the mit person initialization, which is going to go up and call this one. so again i ' m going to be able to find names. and i do a couple of other different things here. i ' m gonna pass in a rank, full professor, associate professor, assistant professor, which i ' m just going to bind locally. but i ' m gonna add one other piece here, which is i ' m gonna add a little dictionary on teaching. so when i create a professor, i ' m gonna associate with it a dictionary that says, what have you been teaching? and then notice the methods i create. i ' ve got a method here called add teaching, takes, obviously a pointer to the instance. a term, which will just be a string, and a subject. and let ' s look at what it does right here. ok. in fact the call i ' m going to make, i ' m not certain i ' m going to be able to get away with it, my machine is still wonderfully broken, all right, it is, let me just show you what the calls would look like. as you can see here i ' m not going to be able to do them. but i ' m going to add teaching, as a method call with this with a string for term, and a subject number. what is this going to do? yeah, i know i ' m just worried if i restart python, i may not be able to pull the thing back in, so i ' m going to try and wing it, john, and see if i can make it happen. right, what does that teaching do? it ' s got one of those try except methods. so what does it say it ' s going to do? it ' s going to go into the dictionary associated with teaching, under the value of term, and get out a list. and it ' s
|
subdomain_quantum_gravity
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.566033
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s got one of those try except methods. so what does it say it ' s going to do? it ' s going to go into the dictionary associated with teaching, under the value of term, and get out a list. and it ' s going to append to the end of the list the new subject. so it ' s going to be stored in there, is then going to be term, and a list of what i taught, in case i teach more than one thing each term. it ' s going to do that, but notice it ' s a try. if in fact there is no term currently in the dictionary, started out empty, it ' s going to throw an error, sorry, not throw an error, it ' s going to raise an exception. which is a key error, in which case notice what i ' m going to do, i ' m not going to treat it as an error. i ' m simply going to say, in that case, just start off with an empty, with an initial list with just that subject in and put it in the dictionary. as i add more things in, i ' ll just keep adding things to this dictionary under that term. and if i want to find out what i ' m doing, well i can use get teaching, which says given the term, find the thing in the dictionary under that term and return it. if i get an error, i ' m going to raise it, which says there is nothing for that term, and in that case i guess i ' m just going to return none. ok? and then the other two pieces we ' re going to have here, and we want to look at a little more carefully, i just wanted to show you that example, is a professor can lecture, and a professor can say something. look at the say method, because this now add one more nuance to what we want to do here. and i think in interest of making this go, let me actually, since i ' m not going to get my machine to do this right, let me create a couple of professors. if i look at what that is, it ' s an mit person because i didn ' t have any separate string thing there, and we will create a more important professor. what rank do you want, john? do you want to stay full? professor 2 : undergraduate. professor : undergraduate, right, a lot more fun i agree. sorry about that, and we can again just see what that looks like.
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subdomain_quantum_computing
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.566863
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professor. what rank do you want, john? do you want to stay full? professor 2 : undergraduate. professor : undergraduate, right, a lot more fun i agree. sorry about that, and we can again just see what that looks like. and that of course, we ' ll print out, he ' s also an mit person. but now here ' s what i want to do. i want to say something to my good colleague professor guttag. actually i ' m going to start a separate - - i ' m going to say something to a smart undergraduate. so if i say, remember we have ug defined as an undergraduate, let me do something a little different here. well let, me do it that way. it says, i don ' t understand why you say you were enjoying 6. 00. not a good thing to say, right, but if i say to my good colleague professor guttag. i have to spell say right, i know, i need help with this, what can i say? we flatter each other all the time. it ' s part of what makes us feel good about ourselves. why is the sky blue? i enjoyed your paper, but why is the sky blue? ok, terrible examples, but what ' s going on here? one more piece that i want to add. here ' s my say method for professor, and now i ' m actually taking advantage of to whom i am saying something. notice again, what does it do? there ' s the self argument, that ' s just pointing to the instance of me. i ' m passing in another argument, going to call it to who, in one case it was ug, in one case it was guttag. and then the thing i want to say, ah, look what it does, it says, check the type. and the type is going to take that instance, i had an instance, for example, of a professor down here, and it ' s going to pick up what type of object it is. so if the type of the person i ' m speaking to is undergrad, let ' s pause for second. remember i started away back saying we ' re building abstract data types. well, here ' s a great example of how i ' m using exactly that, right? i ' ve got int, i ' ve got float, i now have ug, it ' s a type. so it ' s says if the object to whom i ' m speaking is an under
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subdomain_quantum_gravity
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.567692
|
i ' m using exactly that, right? i ' ve got int, i ' ve got float, i now have ug, it ' s a type. so it ' s says if the object to whom i ' m speaking is an undergrad, then use the same method from person where i ' m going to put this on the front. on the other hand, if the object to whom i ' m speaking is a professor, then i ' m going to tag this on the front and use the underlying say method. on the other hand, if i ' m speaking to somebody else, i ' m just going to go lecture. all right, and when a professor lectures, they just put it ' s obvious on the end of things, as you may have noticed. what ' s the point i want you to see here? i ' m now using the instances to help me to find what the code should do. i ' m looking at the type. if the type is this, do that. if the type is this, do something different, ok? and i can now sort of build those pieces up. ok, i said one more class. notice what we ' re doing. i know they ' re silly examples, but, sorry, they are cleverly designed examples to highlight key points. what i ' m trying to do is show you how we have methods inherit methods, how have message shadow methods, how we have methods override methods, how we can use instances as types to define what the method should do. let me show you one last class, because i ' m gonna have one more piece that we want to use. and the last class is, sort of, once you ' ve got a set of professors, you can have an aggregate of them. and i don ' t know, if a group of geese are gaggle, i don ' t know what a set of professors are, john. flamers? i, you know, we ' ve got to figure out what the right collective noun here is. we ' re going to call them a faculty for lack of a better term, right? now the reason i want to show you this example is, this class, notice, it only is going to inherit from object. it actually makes sense. this is going to be a collection of things, but it ' s not a subclass of a particular kind of person. and what i want the faculty to do, is to be able to gather together a set of faculty. so if
|
subdomain_quantum_gravity
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.568537
|
sense. this is going to be a collection of things, but it ' s not a subclass of a particular kind of person. and what i want the faculty to do, is to be able to gather together a set of faculty. so if i go down here, grab this for second, and pull it down so you can see it. it looks like i ' m not going to be able to run this because my machine is broken, but basically i ' m gonna define a set of professors, and then i ' m gonna create a new class called faculty. there ' s the definition of it. it ' s got an init. you can kind of see what it does. it ' s going to set up an internal variable called names, which is initially an empty list, internal variable called ids, which is empty, an internal variable called members, which is empty, and another special variable called place, which we ' re going to come back to in a second, initially bound to none. ok, i ' ve got a method called add which i ' m going to use down here to add professors to the course 6 faculty. here ' s what i want to add to do. first of all, notice i ' m going to check the type. if this is not a professor, i ' m gonna raise an error, a type error, it ' s the wrong type of object to pass in. the second thing i ' m gonna do is say, if that ' s okay, then let me go off and get the id number. now remember, that ' s right up here, so i ' m asking the instance of the professor to go up and get the id number. and i want to make sure i only have one instance of each professor in my faculty, so if the id number is in the list of ids already, i ' m going to raise an error, sorry, raise an exception as well, saying i ' ve got a duplicate id. ok? and the reason that ' s going to come up is, notice what i do now. inside of the instant self, i take the variable names and i add to it the family name of the person i just added. ok, notice the form. i ' m using the method, there ' s the parens to get the family name of the person. i ' m just adding it to the list. i ' ve got the id number, i ' ve added the ids, and i add the object itself into members
|
subdomain_quantum_field_theory
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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|
2025-12-17T20:53:59.569377
|
, there ' s the parens to get the family name of the person. i ' m just adding it to the list. i ' ve got the id number, i ' ve added the ids, and i add the object itself into members. so as i do this, what am i doing? i ' m creating a list, actually several lists : a list of ids, a list of the actual instances, and a list of the family names. and as a cost i want to add, that ' s why i can check and see, is this in here already or not? now, the last reason i want to do this is, i want to be able to support things like that. this is now different, right, this instance is a collection. i want to be able to do things like, for all the things in that collection, do something, like print out the family names. and to do that, i need two special forms : iter and next. ok, now let me see if i can say this cleanly. whenever i use a for, in structure, even if it was on just a normal list you built, what python is doing is returning an, what is called an iterator. which is something that we talked earlier. it ' s keeping track of where are you in the list, and how do i get to the next thing in the list? i ' m going to do the same thing here, and i ' m going to create it for this particular structure. so this little thing iter, when i call a for something in, one of these instances, it calls iter, and notice what it does. it initializes place to 0. that was that variable i had up there. that ' s basically saying i ' m at the beginning of the list. it ' s a pointer to the beginning of the list, and it returns self. just gives me back a pointer to the instance. that now allows me at each step in that loop to call next. and what does next do? next says, check to see if that value is too long, if it ' s longer than, for example, the list of names, raise an exception called stop iteration, which the for loop will use to say ok, i ' m done. i ' m going to break out of the for loop. otherwise, what am i going to do? i ' ll increment place by 1, that ' s going to move me to the next place in
|
subdomain_quantum_gravity
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
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2025-12-17T20:53:59.570373
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ok, i ' m done. i ' m going to break out of the for loop. otherwise, what am i going to do? i ' ll increment place by 1, that ' s going to move me to the next place in the list, and then in this case i ' ll just return the instance itself, right? members is a list of instances, place i ' ve incremented by 1, i take 1 off of it, i get to it. so iter and next work together. iter creates this method, that ' s going to give you a pointer to the place in the structure, and then next literally walks along the structure giving you the next element and returning elements in turn so you can do something with it. right, so now what that says is, i can have classes that just have local variables. i can have classes that get methods from other variables, and i can also have classes that are collections. and i ' ve supported that by adding in this last piece. ok once you have all of that, in principle we could start doing some fun things. so let ' s see what happens if we try and make all of this go. and let me, since i ' m not going to be able to run it, let me simply do it this way. if i have my undergraduate, ug. i can - - sorry, let ' s not do it that way - - i can have undergraduate say things like - - all right, what did i just do wrong here? do i not have undergrad defined? i do. oh, i didn ' t have grimson, sorry, it ' s me, isn ' t it? thank you. the undergraduate very politely asks why he didn ' t understand, you can have the professor respond. again, it simply puts a different thing into there. on the other hand, if professor guttag asks me something about understanding, i say i really like this paper on, you do not understand, it ' s a deep paper on programming languages 5, i think, john, isn ' t it? what else can you do with this thing, right? you can have an undergraduate talk to an undergraduate, in which case they ' re still polite. or you could have - - sorry, let me do that the other way - - you could also have an undergraduate simply talk to a normal person. all right, but the good news is you know eventually you get it done, and when you ' re really done you
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subdomain_quantum_field_theory
| 0.569347
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
| 21
| 0.35
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2025-12-17T20:53:59.571183
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- - sorry, let me do that the other way - - you could also have an undergraduate simply talk to a normal person. all right, but the good news is you know eventually you get it done, and when you ' re really done you can have the undergraduate be really happy about this, and so she sings to herself. ok it ' s a little silly, but notice what we ' ve just illustrated. and this is where i want to pull it together. with a simple set of classes, and the following abilities, an ability to inherit methods from subclasses, sorry from superclasses, that is having this hierarchy of things. i can create a fairly complex kind of interaction. i can take advantage of the types of the objects to help me decide what to do. and if you think about that, i know it sounds very straightforward, but you would do exactly that if you were writing earlier code to deal with some numerical problem. all right, if the thing is an integer, do this, if it ' s a float, do that, if it ' s a string, do something else. i ' m now giving you exactly the same ability, but the types now can be things that you could create. and what i ' ve also got is now the ability to inherit those methods as they go up the chain. so another way of saying it is, things that you want to come away from here, are, in terms of these classes. we now have this idea of encapsulation. i ' m gathering together data that naturally belongs as a unit, and i ' m gathering together with it methods that apply to that unit. just like we would have done with float or int. ideally, we data hide, we don ' t happen to do it here, which is too bad. basically we ' ve got the idea of encapsulation. the second thing we ' ve got is this idea of inheritance. inheritance both meaning i can inherit attributes or field values. i can inherit methods by moving up the chain. i can also the shadow or override methods, so that i can specialise. and i do all of that with this nice hierarchy of classes. so what hopefully you ' ve seen, between these two lectures, and we ' re going to come back to it in some subsequent lectures, is that this is now a different way of just structuring a computational system. now, you ' ll also get arguments, polite arguments from faculty members or other experts about which is a better
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subdomain_quantum_cryptography
| 0.578506
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:356021a3-01be-42dc-ae50-e22e74e8edfd>
| 22
| 0.35
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2025-12-17T20:53:59.571993
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on monday the american library association will announce the winner of its highest award for a picture book, named for the great english illustrator randolph caldecott ( 1846 – 1886 ). why was caldecott so important? here ’ s an answer from maurice sendak, who won the caldecott medal for where the wild things are : “ caldecott ’ s work heralds the beginning of the modern picture book. he devised an ingenious juxtaposition of picture and word, a counterpoint that had never happened before. words are left out – but the picture says it. pictures are left out – but the word says it. in short, it is the invention of the picture book. ” * * * “ my favorite example of caldecott ’ s fearless honesty is the final page of hey diddle diddle. after we read, ‘ and the dish ran away with the spoon, ’ accompanied by a drawing of the happy couple, there is the shock of turning the page and finding a picture of the dish broken into ten pieces – obviously dead – and the spoon being hustled away by her angry parents. there are no words that suggest such an end to the adventure ; it is purely a caldecottian invention. apparently, he could not resist enlarging the dimensions of this jaunty nursery rhyme by adding a last sorrowful touch. ” maurice sendak in caldecott & co. : notes on books & pictures ( farrar, straus and giroux, 1988 ), a collection of sendak ’ s reviews and other writing for adults. the first quote comes from his essay “ randolph caldecott ” and the second from his acceptance speech for the 1964 caldecott medal. sendak is one of the few great picture - book artists who is also a great critic. caldecott & co. has only a dozen pages of pictures but doesn ’ t need more, because sendak makes you see books without them. ( c ) 2008 janice harayda. all rights reserved.
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subdomain_quantum_field_theory
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| 412
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HuggingFaceFW/fineweb-edu
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<urn:uuid:58173a97-2e2e-475a-a66c-15b07e6cedae>
| 0
| 0.35
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2025-12-17T20:53:59.576429
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a main character ’ s name often gives you the first clue to what a novel is “ about, ” especially when it ’ s also the title of the book. a good example turns up in olive kitteridge, the collection of linked short stories that won the 2009 pulitzer prize for fiction. a just - picked olive is as bitter — and the color olive is as drab — as the title character of the book appears at first to be. the salt added during curing removes the bitterness just as love, the salt in this book, removes some of olive ’ s. in ireland a kitter is a left - handed person. and olive is at least metaphorically left - handed : she ’ s out of sync with others in her coastal town in maine. a surname database says of kitter : “ this is an olde english or anglo - saxon pre 10th century name which derives from the word ‘ cyta ’ and is a nickname of the medieval period generally given to one of fairly violent attitudes. ” olive ’ s views of life are “ fairly violent, ” especially in the first story, when they are so angry they verge on caricature. may 29, 2009 what ’ s in a character ’ s name? ‘ olive kitteridge ’ leave a comment » no comments yet.
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subdomain_quantum_gravity
| 0.496802
| 262
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HuggingFaceFW/fineweb-edu
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<urn:uuid:13555330-9462-4be5-bb21-d21bfedac74b>
| 0
| 0.35
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2025-12-17T20:53:59.578299
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talk : 20. 109 ( f12 ) pre - proposal : engineering viral magnetic nanoparticles for magnetic hyperthermic cancer therapy - this is a brainstorming page. you are very welcome to write any crazy / non - crazy / inventive / conventional / knowledgeable ideas or information you may have about our project. some key words : magnetic nanoparticles ( mnp ), viruses, magnetic hyperthermia, bioengineering what is magnetic hyperthermia? how it works? under an alternating magnetic field, mnp releases heat due to relaxation of magnetic moments ( hysteresis ). this can cause an increase in temperature to the range of 41c to 47c. since tumor cells are more heat sensitive than normal cells, they will be killed by this thermal dissipation. here is an interesting tidbit from a paper i was reading : " in addition to the expected tumor cell death, hyperthermia treatment has also induced unexpected biological responses, such as tumor - specific immune responses as a result of heat - shock protein expression. these results suggest that hyperthermia is able to kill not only local tumors exposed to heat treatment, but also tumors at distant sites, including metastatic cancer cells. " ( kobayashi ) - clinical trials in prostate cancer - shows promising results when coupled with irradiation on breast cancer ( mouse ) current limitations ( this information will help us shape and define the problem. ) ( 1 ) to achieve the necessary rise in temperature with minimal dose of mnp. - in other words, this means : - high specific loss power / specific absorption rate ( slp ) of the mnp. - why is higher applied dosage bad? > leads to unnecessary heat dissipation ( 2 ) lack of knowledge about the metabolism, clearance, and toxicity of mnp. biomedical potentials of mnp - could be used as early detection for the following using mri : - drug delivery - cellular labeling and tissue targeting - purifying and separating cells and dnas - transfection by magnetic nanoparticles - tissue repair - magnetic resonance imaging ( mri ) types of relevant viruses 1. tobacco mosaic virus ( tmv ) - 18nmx300nm, helical - can withstand high temperatures up to 50c for 30mins ( conventional hyperthermia involves heating up to 50c from an external source - safe for human consumption - mann group has active research on it - 2130 molecules of coat protein 2. m13 bacteriophage -
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subdomain_quantum_thermodynamics
| 0.579185
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:02670295-3a47-4d18-b098-38a53e1f91ab>
| 0
| 0.35
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2025-12-17T20:53:59.585179
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50c for 30mins ( conventional hyperthermia involves heating up to 50c from an external source - safe for human consumption - mann group has active research on it - 2130 molecules of coat protein 2. m13 bacteriophage - 6. 6nmx880nm, helical ( length is too long - pose an issue in targeting cells ) - lots of research done by the belcher group, including attaching mnps to m13 for imaging purposes - we are familiar with the system 3. cowpea chlorotic mottle virus ( ccmv ) - 26nm, icosahedral 4. cowpea mosaic virus ( cpmv ) - 27nm, icosahedral 5. brome mosaic virus ( bmv ) - 28nm, icosahedral 6. turnip yellow mosaic virus ( tymv ) - 30nm, icosahedral current work in viral mnp attachment attachment of mnps to m13 phage for in vivo imaging of prostate cancer what we propose to do see flowchart sketch. - identifying / screening for appropriate virus vehicles and tumor - specific anchoring sequencse - developing / engineering viral mnps - in vivo testing for efficacy of engineered vmnps in mouse tumor cells. we will start with using ferritin ( fe3o4 ) as the mnp. stage 1 : virus hunt - we need to investigate how the selected virus ( likely one of the following : tmv, m13, ccmv, cpmv, bmv or tpmv ) interacts with mammalian cells in vivo. stage 2 : screening for mnp binding site on virus - we will start by using fe3o4 as our mnp of interest. with this, a protein coat screen of the selected virus for a protein coat that can bind with our mnp is necessary. stage 3 : screening for tumor - specific sequence binding site on virus - we need to do a protein coat or rna screen of the virus for a region that can bind with a tumor - specific peptide sequence. if necessary, we might need to screen tumors for unique short sequences on their cell surfaces. stage 4 : virus engineering - we can now engineer wild - type viruses using specific protein coats or rna regions isolated in stage 2 and 3 to produce the viral mnp of interest. stage 5 : in vivo testing - perform an in vivo experiment by injecting the engineered viral mnps into the circulatory system of
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subdomain_quantum_metrology
| 0.533574
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:02670295-3a47-4d18-b098-38a53e1f91ab>
| 1
| 0.35
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2025-12-17T20:53:59.586080
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specific protein coats or rna regions isolated in stage 2 and 3 to produce the viral mnp of interest. stage 5 : in vivo testing - perform an in vivo experiment by injecting the engineered viral mnps into the circulatory system of mice that have developed tumors. by subjecting these mice to an alternating magnetic field under standard hyperthermia conditions and measuring the change in tumor size, we will be able to quantify the efficacy of using viral mnps in magnetic hyperthermia. - experimenting with double layer mnp to increase response - target other cancerous cells - experiment with other types of viruses quantitative goals ( we can quantify with ic50 value ) - currently, with the aid of 10gy radiation, the hyperthermia treatment successfully accumulated less than 0. 3mg fe / g tissue. dosage : 0. 2mg fe per gram of mouse. say mouse is 25g, so 5mg total dosage injected. so 1 % efficiency with the aid of radiation. ( mnp sizes used : 70nm and 120nm ; murine flank breast tumors were 150mm3 ) from http : / / manalis - lab. mit. edu / publications / grover % 20pnas % 202011. pdf, we estimated that a typical cell has an average density of 1. 1g / ml. since the murine flank breast tumors were 150mm3, and 0. 25mg fe / g of tumor was detected in the tumors, we can calculate that only a total of 0. 0495mg of fe is accumulated in the tumors. this gives a % efficacy of 1 %. - south korean experiment : 75ug of mnps were injected. - from belcher lab ' s paper, what is the % efficacy of using m13? - " the actual rotations of the nanoparticles are disordered because the microviscosity of the local environment in cancer cells is not constant, and effective elasticity depends on the binding conditions between nanoparticles and membranes. " - but this is actually present because when treatment is done with individual mnps, one side of the mnp is always bound to the targeted cell, so direction is never constant! - gupta ak, naregalkar rr, vaidya vd, and gupta m. recent advances on surface engineering of magnetic iron oxide nanoparticles and their biomedical applications. future medicine. 2007. 2 ( 1 ), 23 - 39. - bakoglidis kd, simeonidis k
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subdomain_quantum_optics
| 0.552648
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:02670295-3a47-4d18-b098-38a53e1f91ab>
| 2
| 0.35
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2025-12-17T20:53:59.586953
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##d, and gupta m. recent advances on surface engineering of magnetic iron oxide nanoparticles and their biomedical applications. future medicine. 2007. 2 ( 1 ), 23 - 39. - bakoglidis kd, simeonidis k, sakellari d, g. stefanou, and angelakeris m. size - dependent mechanisms in ac magnetic hyperthermia response of iron - oxide nanoparticles. ieee transactions on magnetics. 2012. 48 : 1320 - 1323. - great layman ' s way of explaining magnetic hyperthermia http : / / trialx. com / curetalk / 2012 / 11 / cancer - treatment - multifunctional - magnetic - nanoparticles - for - molecular - imaging - and - hyperthermia / - a. j. giustini, a. a. petryk, s. m. cassim, j. a. tate, i. baker, p. j. hoopes. magnetic nanoparticle hyperthermia in cancer treatment. nano life 2010 ; 01 : 17. - d. ghosh, y. lee, s. thomas, a. g. kohli, d. s. yun, a. m. belcher, k. a. kelly. m13 - templated magnetic nanoparticles for targeted in vivo imaging of prostate cancer. nat. nanotechnol. 2012 ; 7 ( 10 ) : 677 – 82. - add more references as deem appropriate 11 / 29 from professor angela belcher : - look at nature nano belcher lab paper - need to do very good characterization of materials using tem, elemental analysis, etc.
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subdomain_quantum_thermodynamics
| 0.535159
| 345
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HuggingFaceFW/fineweb-edu
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<urn:uuid:02670295-3a47-4d18-b098-38a53e1f91ab>
| 3
| 0.35
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2025-12-17T20:53:59.587483
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sleep apnea is a condition in which breathing is repeatedly interrupted during sleep. the time period for which the breathing stops or decreases is usually between 10 and 30 seconds. when these episodes occur repeatedly, sleep apnea can seriously disrupt the quality of sleep. there are three types of respiratory events : - obstructive apnea — caused by a temporary, partial, or complete blockage of the airway - central apnea — caused by a temporary failure to make an effort to breathe - mixed apnea — combination of the first two types these factors increase your chance of developing sleep apnea. tell your doctor if you have any of these risk factors : - sex : male - large neck circumference - age : middle to older age - family history of apnea structural abnormalities of the nose, throat, or other part of the respiratory tract. examples include : - severely enlarged tonsils - deviated nasal septum - medicines : sedatives and sleeping aids - alcohol consumption - fatigue and sleepiness during waking hours - loud snoring - breathing that stops during the night ( noticed by the partner ) - repeated waking at night - unrefreshing sleep - morning headaches - poor concentration or problems with memory - irritability or short temper people with chronic untreated sleep apnea may be at risk for : an overnight sleep study is used to help diagnose sleep apnea. overnight sleep study ( polysomnography ) this test helps detect the presence and severity of sleep apnea. during sleep, it measures your : - eye and muscle movements - brain activity ( electroencephalogram ) - heart rate - breathing ( pattern and depth ) - percent saturation of your red blood cells with oxygen there are a number of treatment options for sleep apnea, including : - lose weight if you are overweight. - avoid using sedatives, sleeping pills, alcohol, and nicotine, which tend to make the condition worse. - try sleeping on your side instead of your back. - place pillows strategically so you are as comfortable as possible. - for daytime sleepiness, practice safety measures, such as avoiding driving or operating potentially hazardous equipment. continuous positive airway pressure ( cpap ) entails wearing a mask over your nose and / or mouth during sleep. an air blower forces enough constant and continuous air through your air passages to prevent the tissues from collapsing and blocking the airway. in some cases, dental appliances that help keep the tongue or jaw in a more forward position may help. in some
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subdomain_quantum_optics
| 0.521951
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:da610566-65f7-4f92-a0b9-cbf818d8ece0>
| 0
| 0.35
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2025-12-17T20:53:59.590606
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. an air blower forces enough constant and continuous air through your air passages to prevent the tissues from collapsing and blocking the airway. in some cases, dental appliances that help keep the tongue or jaw in a more forward position may help. in some cases, surgery may be recommended. it is most often beneficial in pediatric patients. types of surgery that may be done to treat severe cases of sleep apnea include : - uvulopalatopharyngoplasty — the doctor removes excess soft tissue from the nose and / or throat. - maxillomandibular advancement — the jawbone is repositioned forward. - tracheotomy — for life - threatening cases of sleep apnea, an opening is made in the windpipe to allow for normal breathing. bariatric surgery may help with weight loss in some people who are obese. this surgery may reduce many of the complications that are related to obesity, including sleep apnea. only used in central apnea, acetazolamide ( diamox ) may help improve the ability to regulate breathing. overall, there is not a lot of evidence to support the use of medicines to treat sleep apnea. supplemental oxygen may be given if blood levels of oxygen fall too low during sleep, even after opening the airway. you may be able to prevent the onset of sleep apnea by maintaining a healthy weight. avoid alcohol, nicotine, and sedatives, which may contribute to airway obstruction. - reviewer : rimas lukas, md - review date : 09 / 2012 - - update date : 00 / 93 / 2012 -
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subdomain_quantum_metrology
| 0.409064
| 326
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HuggingFaceFW/fineweb-edu
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<urn:uuid:da610566-65f7-4f92-a0b9-cbf818d8ece0>
| 1
| 0.35
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2025-12-17T20:53:59.591196
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kristensen, hanne l. and thorup - kristensen, kristian ( 2006 ) roots below one meters depth are important for nitrate uptake by annual crops. [ rødder under 1 meters dybde er vigtige for et - arige afgrøders optagelse af nitrat. ] in : cd - rom " the american society of agronomy - crop science society of america - soil science society of america international annual meetings, november 12 - 16, 2006, indianapolis, usa. no. 205 - 9., cd - rom " the american society of agronomy - crop science society of america - soil science society of america international annual meetings, november 12 - 16, 2006, indianapolis, usa., no. abstract no. 205 - 9.. the root depths of annual crops vary from 0. 2 m to more than 2 m depending on root growth rate and length of growing season. however, studies of root growth and n uptake are often restricted to a depth of 1 m or less, as root biomass is assumed to be negligible below this depth. we have studied the importance of root growth and n uptake to a depth of 2. 5 m in fully grown field vegetables and cover crops by use of minirhizotrons and deep point placement of 15n. deep rooted crucifereous crops were found to have high root densities to a depth of 1. 5 - 2 m and high 15n uptake to this depth. the work shows that knowledge of the interactions between root growth and soil n below a depth of 1 m are important to understand crop n uptake and nitrate leaching from agro - ecosystems. | eprint type : | | conference paper, poster, etc. | | type of presentation : | | paper | | subjects : | | soil > nutrient turnover | crop husbandry > crop combinations and interactions crop husbandry > production systems > vegetables | research affiliation : | | denmark > darcof iii ( 2005 - 2010 ) > vegqure - organic cropping systems for vegetable production | denmark > au - aarhus university > au, djf - faculty of agricultural sciences | deposited by : | | kristensen, ph. d. hanne l. | | deposited on : | | 28 nov 2007 | | last modified : | | 12 apr 2010 07 : 35 | | refereed : | | peer - reviewed and accepted | repository staff only : item control page
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subdomain_quantum_optics
| 0.485862
| 503
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HuggingFaceFW/fineweb-edu
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<urn:uuid:d2b3502d-1c86-4ed7-9c72-a55bc162b976>
| 0
| 0.35
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2025-12-17T20:53:59.595061
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we had a running joke in science ed that kids get so overexposed to discrepant events involving density and air pressure that they tend to try to explain anything and everything they don ' t understand with respect to science in terms of those two concepts. why do we have seasons? ummm... air pressure? why did dr. smith use that particular research design? ummm... density? i think we need another catch - all explanation. i suggest index of refraction. to simplify greatly, index of refraction describes the amount of bending a light ray will undergo as it passes from one medium to another ( it ' s also related to the velocity of light in both media, but i do want to keep this simple ). if the two media have significantly different indices, light passing from one to the other at an angle ( not perpendicularly, in which case there is no bending ) will be bent more than if indices of the two are similar. the first four data points are from hyperphysics, the final one from wikipedia... glass has a wide range of compositions and thus indices of refraction. water at 20 c : 1. 33 typical soda - lime glass : close to 1. 5 since glycerine and glass have similar ior, light passing from one to the other isn ' t bent ; as long as both are transparent and similarly colored, each will be effectively " invisible " against the other. so, why does it rain? umm... index of refraction? a bright moon impact 12 hours ago
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subdomain_quantum_optics
| 0.604974
| 317
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HuggingFaceFW/fineweb-edu
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<urn:uuid:7eeb7ef3-3122-42f0-86c8-01da8f3d7396>
| 0
| 0.35
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2025-12-17T20:53:59.596474
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by justin moyer the washington post — defense secretary leon panetta signed an order thursday allowing women the same opportunities as men to serve in combat, including formerly off - limits assignments on attack submarines and in the navy seals. just two weeks before the announcement, researchers from san diego ' s naval health research center published a study suggesting that some recent mothers deployed on the battlefield may be more prone to depression after seeing action. " women who deploy and report combat - associated exposures after childbirth are significantly more likely to screen positive for maternal depression than are women who did not deploy after childbirth, " concluded the study, titled " is military deployment a risk factor for maternal depression? " and appearing in the journal of women ' s health. " it is also possible, " the report noted, " that giving birth and leaving a young child, in addition to the experience of combat, contribute to postdeployment depression. " the study included eight co - authors, five of them associated with the naval health research center, a research and development laboratory within the department of defense. it was based on surveys of more than 1, 600 women who " gave birth during active duty service. " not all branches of the armed forces showed the same results. " participants who served in the army had an increased risk of maternal depression ; army service members tend to be deployed longer and more frequently than personnel serving in the navy and air force, " the study found. of course, you don ' t have to be a mom to experience depression on the front line. the report points out that " the increased rate of depression is primarily attributed to experiencing combat while deployed, " not just to whether a solider is also a parent.
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subdomain_quantum_optics
| 0.439943
| 342
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HuggingFaceFW/fineweb-edu
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<urn:uuid:5a5aeb9f-2d6c-45df-aca0-8ea28cde7f62>
| 0
| 0.35
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2025-12-17T20:53:59.598061
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an introduction to 127. 0. 0. 1 127. 0. 0. 1 is an ip address utilized for a looplock network connection. what does this mean? if a user tries to connect to this ip address, they will be sent back to their computer. the address is also known as a localhost. the localhost is the computer. how the localhost works if the command is relayed to the localhost, you would be hooked up to the system where the commands were sent out. for instance, suppose the computer is called " joker ". if you telnet from the joker computer to the localhost, a message will appear. it will attempt to hook up to the localhost is employed in lieu of the computer hostname to be linked to. this ip address is the most wisely used localhost address. however, you can actually use any ip address provided it starts with 127. this means 127. *. *. * can be used as a localhost. establishing a connection with the loopback address is similar to creating a connection with remote network computers. the only difference is you don ' t have to deal with network for this reason it is widely utilized by software developers. it is also used by system administrators. it is often used for testing programs and apps. if the connection is ipv4, the computer ' s loopback address will be the 127. *. *. *. the subnet mask is typically 255. 0. 0. 0. this ip addresses 127. *. *. *. are defined in rfc 330 as special - use ipv4 addresses. the 127. 0. 0. 0 / 8 block is defined as the net host loopback address. if a higher level protocol sends a datagram anywhere in the block, it will be looped in the host. this is typically implemented with the 127. 0. 0. 1 / 32 for looplock. however, addresses in the block must not be visible anywhere else in the network. there is also a localhost ipv6 version. in rfc 3513, it is defined as internet protocol version 6 ( ipv6 ) addressing architecture : : 1 / 128. more information about the localhost in simple terms, the localhost means the computer. it is the hostname allocated loopback network interface address. the name is likewise a domain name. this will help prevent confusion with the hostname definition. in ipv6, the loopback ip address
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subdomain_quantum_cryptography
| 0.536148
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:0cfb12fb-ebfd-4e6a-8720-c551d7e97801>
| 0
| 0.35
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2025-12-17T20:53:59.601386
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municipal incorporation occurs when such municipalities become self - governing entities under the laws of the state or province in which they are located. often, this event is marked by the award or declaration of a municipal charter. with the notable exception of the city of london corporation, the term has fallen out of favour in the united kingdom, but the concept remains central to local government in the united kingdom, as well as former british colonies such as india and canada. municipal charters a city charter or town charter ( generically, municipal charter ) is a legal document establishing a municipality such as a city or town. the concept developed in europe during the middle ages and is considered to be a municipal version of a constitution. traditionally the granting of a charter gave a settlement and its inhabitants the right to town privileges under the feudal system. townspeople who lived in chartered towns were burghers, as opposed to serfs who lived in villages. towns were often " free ", in the sense that they were directly protected by the king or emperor, and were not part of a feudal fief. today the process for granting charters is determined by the type of government of the state in question. in monarchies, charters are still often a royal charter given by the crown or the state authorities acting on behalf of the crown. in federations, the granting of charters may be within the jurisdiction of the lower level of government such as a state or province. by country in brazil, municipal corporations are called municipios and are created by means of local legislation at state level, or after passing a referendum vote of the affected population. all municipal corporations must also abide by an organic municipal law which is passed and amended ( when needed ) at municipal level. in canada charters are granted by provincial authorities. in germany, municipal corporations existed since antiquity and through medieval times, until they became out of favour during the absolutism. in order to strengthen the public spirit the city law of prussia dated 19 november 1808 picked up this concept. it is the basis of today ' s municipal law. in india a municipal corporation is a local government body that administers a city of population 10, 00, 000 or more. under the panchayati raj system, it interacts directly with the state government, though it is administratively part of the district it is located in. the largest municipal corporations in india currently are mumbai, followed by delhi, kolkata, bangalore, chennai, hyderabad, ahmedabad, surat and pune. the corporation of chennai is the oldest municipal corporation in the world outside uk. the municipal
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subdomain_quantum_field_theory
| 0.492633
| 512
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HuggingFaceFW/fineweb-edu
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<urn:uuid:ff2d2b6b-aa78-4bda-ba69-e90f18d28bfb>
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| 0.35
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2025-12-17T20:53:59.605340
|
is located in. the largest municipal corporations in india currently are mumbai, followed by delhi, kolkata, bangalore, chennai, hyderabad, ahmedabad, surat and pune. the corporation of chennai is the oldest municipal corporation in the world outside uk. the municipal corporation consists of members elected from the wards of the city. the mayor and deputy mayor are elected by the public. a municipal commissioner, who is from the indian administrative service is appointed to head the administrative staff of the municipal corporation, implement the decisions of the corporation and prepare its annual budget. the municipal corporation is responsible for roads, public transportation, water supply, records of births and deaths ( delegated from central government births and deaths registration act ), sanitation that includes waste management, sewage, drainage and flood control, public safety services like fire and ambulance services, gardens and maintenance of buildings. the sources of income of the corporation are property tax, entertainment tax, octroi ( now abolished from many cities ) and usage fees for utilities. republic of ireland in ireland, municipal corporations existed in boroughs since medieval times. the corporation of dublin, officially styled the right honourable the lord mayor, aldermen, and burgesses of the city of dublin had existed since the 13th century. corporations were established under the royal charter establishing the city or borough. the municipal corporations ( ireland ) act 1840 abolished all but ten of the boroughs and their corporations. the local government ( ireland ) act 1898 created two different types of borough, county boroughs had essentially equal status to counties - these comprised dublin, cork, limerick, and waterford ( as well as belfast and derry, which are now in northern ireland ). the other boroughs were non - county boroughs. the local government act 2001 abolished the title of municipal corporation. corporations of county boroughs ( renamed cities ) were renamed city councils. non county boroughs were abolished, but those towns which were previously non - county boroughs were allowed to use the title of borough council. royal charters remain in force for ceremonial and civic purposes only. south africa from the beginning of american colonial rule, philippines cities were formally established through laws enacted by the various national legislatures in the country. the philippine commission gave the city of manila its charter in 1901, while the city of baguio was established by the philippine assembly which was composed by elected members instead of appointed ones. during the commonwealth era, the national assembly established an additional ten cities. since achieving independence from the united states in 1946 the philippine congress has established 124 more cities ( as of september 2007 ), the majority of which required the holding of a pleb
|
subdomain_quantum_optics
| 0.40689
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:ff2d2b6b-aa78-4bda-ba69-e90f18d28bfb>
| 1
| 0.35
|
2025-12-17T20:53:59.606334
|
| gallium metal is silver - white and melts at approximately body temperature ( wikipedia image ). | | atomic number : | | 31 | | atomic radius : | | 187 pm ( van der waals ) | | atomic symbol : | | ga | | melting point : | | 29. 76 °c | | atomic weight : | | 69. 72 | | boiling point : | | 2204 °c | | electron configuration : | | [ ar ] 4s23d104p1 | | oxidation states : | | 3 | from the latin word gallia, france ; also from latin, gallus, a translation of " lecoq, " a cock. predicted and described by mendeleev as ekaaluminum, and discovered spectroscopically by lecoq de boisbaudran in 1875, who in the same year obtained the free metal by electrolysis of a solution of the hydroxide in koh. gallium is often found as a trace element in diaspore, sphalerite, germanite, bauxite, and coal. some flue dusts from burning coal have been shown to contain as much 1. 5 percent gallium. it is one of four metals - - mercury, cesium, and rubidium - - which can be liquid near room temperature and, thus, can be used in high - temperature thermometers. it has one of the longest liquid ranges of any metal and has a low vapor pressure even at high temperatures. there is a strong tendency for gallium to supercool below its freezing point. therefore, seeding may be necessary to initiate solidification. ultra - pure gallium has a beautiful, silvery appearance, and the solid metal exhibits a conchoidal fracture similar to glass. the metal expands 3. 1 percent on solidifying ; therefore, it should not be stored in glass or metal containers, because they may break as the metal solidifies. high - purity gallium is attacked only slowly by mineral acids. gallium wets glass or porcelain and forms a brilliant mirror when it is painted on glass. it is widely used in doping semiconductors and producing solid - state devices such as transistors. magnesium gallate containing divalent impurities, such as mn + 2, is finding use in commercial ultraviolet - activated powder phosphors. gallium arsenide is capable of converting electricity directly into coherent light. gallium readily alloys with most metals, and has been used as a component in low - melting alloys.
|
subdomain_quantum_thermodynamics
| 0.518091
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:317a0fc8-b8f1-4147-a9ac-f69a1f176048>
| 0
| 0.35
|
2025-12-17T20:53:59.608628
|
from oxford university press : there is a broad consensus among scholars that the idea of human rights was a product of the enlightenment but that a self - conscious and broad - based human rights movement focused on international law only began after world war ii. in this narrative, the nineteenth century ' s absence is conspicuous - - few have considered that era seriously, much less written books on it. but as jenny martinez shows in this novel interpretation of the roots of human rights law, the foundation of the movement that we know today was a product of one of the nineteenth century ' s central moral causes : the movement to ban the international slave trade. originating in england in the late eighteenth century, abolitionism achieved remarkable success over the course of the nineteenth century. martinez focuses in particular on the international admiralty courts, which tried the crews of captured slave ships. the courts, which were based in the caribbean, west africa, cape town, and brazil, helped free at least 80, 000 africans from captured slavers between 1807 and 1871. here then, buried in the dusty archives of admiralty courts, ships ' logs, and the british foreign office, are the foundations of contemporary human rights law : international courts targeting states and non - state transnational actors while working on behalf the world ' s most persecuted peoples - - captured west africans bound for the slave plantations of the americas. fueled by a powerful thesis and novel evidence, martinez ' s work will reshape the fields of human rights history and international human rights law. - forces us to fundamentally rethink the origins of human rights activism - filled with fascinating stories of captured slave ship crews brought to trial across the atlantic world in the nineteenth century - shows how the prosecution of the international slave trade was crucial to the development of modern international law
|
subdomain_quantum_cryptography
| 0.503523
| 353
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:ec191471-6e59-4d54-afce-3997eab364e0>
| 0
| 0.35
|
2025-12-17T20:53:59.611030
|
phantom phone calls ospri. net - alleged contact with the dead has occurred universally throughout history, taking various forms ; as dreams, waking visions and auditory hallucinations, either spontaneous or induced through trance. in many cultures, the spirits of the dead have been sought for their wisdom, advice and knowledge of the future. the dead also seem to initiate their own communication, using whatever means seem to be most effective. with the advent of electromagnetic technology, mysterious messages have been communicated by telegraph, wireless, phonographs and radio. a curious phenomenon of modern times is the communication via the telephone. phone calls from the dead seem to be random and occasional occurrences that happen without explanation. the great majority are exchanges between persons who shared a close emotional tie while both were living : spouses, parents and children, siblings, and occasionally friends and other relatives. most communications are " intention " calls, initiated by the deceased to impart a message, such as farewell upon death, a warning of impending danger, or information the living needs to carry out a task. for example, actress ida lupino ' s father, stanley, who died intestate in london during world war ii, called lupino six months after his death to relate information concerning his estate, the location of some unknown but important papers. some calls appear to have no other purpose than to make contact with the living ; many of these occur on emotionally charged " anniversary " days, such as mothers day or fathers day, a birthday or holiday. in a typical ” anniversary ” call, the dead may do nothing more than repeat a phrase over and over, such as " hello, mom, is that you? " persons who have received phone calls from the dead report that the voices are exactly the same as when the deceased was living, furthermore, the voice often uses pet names and words. the telephone usually rings normally, although some recipients say that the ring sounded flat and abnormal. in many cases, the connection is bad, with a great deal of static and line noise, and occasionally the faint voices of the other persons are heard, as though lines have been crossed. in many cases, the voice of the dead one is difficult to hear and grows fainter as the call goes on. sometimes, the voice just fades away but the line remains open, and the recipient hangs up after giving up on further communication. sometimes the call is terminated by the dead and the recipient hers the click of disengagement, other times, the line simply goes dead. the phantom phone calls typically
|
subdomain_quantum_entanglement
| 0.525561
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:c6d4bada-2535-41ff-b2c6-f0357a52e392>
| 0
| 0.35
|
2025-12-17T20:53:59.616031
|
line remains open, and the recipient hangs up after giving up on further communication. sometimes the call is terminated by the dead and the recipient hers the click of disengagement, other times, the line simply goes dead. the phantom phone calls typically occur when the recipient is in a passive state of mind. if the recipient knows the caller is dead, the shock is great and the phone call very brief, invariably, the caller terminates the call after a few seconds or minutes, or the line goes dead. if the recipient does not know the caller is dead, a lengthy conversation of up to 30 minutes or so may take place, during which the recipient is not aware of anything amiss. in a minority of cases, the call is placed person - to - person, long - distance with the assistance of a mysterious operator. checks with the telephone company later turn up no evidence of a call being places. similar phone calls from the dead are " intention " phone calls occurring between two living persons. such calls are much rarer than calls from the dead. in a typical " intention " call, the caller thinks about making the call but never does, the recipient nevertheless receives a call. in some cases, emergencies precipitate phantom calls, a surgeon is summoned by a nurse to the hospital to perform an emergency operation, a priest is called by a " relative " to give last rites to a dying man and so forth. some persons who claim to have had ufo encounters report receiving harassing phantom phone calls. the calls are received soon after the witness returns home, or within a day or two of the encounter, in many cases, the calls come before the witness has shared the experience with anyone, stranger still, they are often placed to unlisted phone numbers. the unidentified caller warns the witness not to talk and to " forget " what he or she saw. phone calls allegedly may be placed to the dead as well. the caller does not find out until sometime after the call that the person on the other end has been dead. in one such case, a woman dreamed of a female friend she had not seen for several years. in the disturbing dream, she witnessed the friend sliding down into a pool of blood. upon awakening, she worried that the dream was a portent of trouble, and called the friend. she was relieved when the friend answered. the friend explained that she had been in the hospital, had been released and was due to be readmitted in a few days. she demurred when the woman offered to visit
|
subdomain_quantum_entanglement
| 0.512879
| 512
|
HuggingFaceFW/fineweb-edu
|
<urn:uuid:c6d4bada-2535-41ff-b2c6-f0357a52e392>
| 1
| 0.35
|
2025-12-17T20:53:59.616957
|
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