of a water - ice lattice. they form beneath permafrost and on the ocean floor under conditions of moderately high pressure and at temperatures near the freezing point of water. natural gas lease production : gross withdrawals of natural gas minus gas production injected on the lease into producing reservoirs, vented, flared, used as fuel on the lease, and nonhydrocarbon gases removed in treating or processing operations on the lease. natural gas liquids ( ngl ) : those hydrocarbons in natural gas that are separated from the gas as liquids through the process of absorption, condensation, adsorption, cooling in gas separators, gas processing, or gas cycling plants. generally, natural gas liquids include natural gas plant liquids and lease condensate. natural gas marketed production : gross withdrawals of natural gas from production reservoirs, less gas used for reservoir repressuring, nonhydrocarbon gases removed in treating and processing operations, and quantities vented and flared. natural gas marketer : a company that arranges purchases and sales of natural gas. unlike pipeline companies or local distribution companies, a marketer does not own physical assets commonly used in the supply of natural gas, such as pipelines or storage fields. a marketer may be an affiliate of another company, such as a local distribution company, natural gas pipeline, or producer, but it operates independently of other segments of the company. in states with residential choice programs, marketers serve as alternative suppliers to residential users of natural gas, which is delivered by a local distribution company. natural gas plant liquids : those hydrocarbons in natural gas that are separated as liquids at natural gas processing plants, fractionating and cycling plants, and in some instances, field facilities. lease condensate is excluded. products obtained include liquefied petroleum gases ( ethane, propane, and butanes ), pentanes plus, and isopentane. component products may be fractionated or mixed. natural gas processing plant : facilities designed to recover natural gas liquids from a stream of natural gas that may or may not have passed through lease separators and / or field separation facilities. these facilities control the quality of the natural gas to be marketed. cycling plants are classified as gas processing plants. natural gas production : see dry natural gas production. natural gas used for injection : natural gas used to pressurize crude oil reservoirs in an attempt to increase oil recovery or in instances where there is no market for the natural gas. natural gas used for injection is sometimes referred to as rep


repressuring of oil reservoirs, and conservation operations ; less ( 2 ) shrinkage resulting from the removal of lease condensate ; and less ( 3 ) nonhydrocarbon gases where they occur in sufficient quantity to render the gas unmarketable. note : volumes of gas withdrawn from gas storage reservoirs and native gas that has been transferred to the storage category are not considered part of production. this production concept is not the same as marketed production, which excludes vented and flared gas. proved energy reserves : estimated quantities of energy sources that analysis of geologic and engineering data demonstrates with reasonable certainty are recoverable under existing economic and operating conditions. the location, quantity, and grade of the energy source are usually considered to be well established in such reserves. note : this term is equivalent to " measured reserves " as defined in the resource / reserve classification contained in the u. s. geological survey circular 831, 1980. measured and indicated reserves, when combined, constitute demonstrated reserves. - deliveries of fuel to an electric plant - purchases of fuel - all revenues received by an exporter for the reported quantity exported - also see received. shale gas : natural gas produced from wells that are open to shale formations. shale is a fine - grained, sedimentary rock composed of mud from flakes of clay minerals and tiny fragments ( silt - sized particles ) of other materials. the shale acts as both the source and the reservoir for the natural gas. see natural gas. supplemental gaseous fuels supplies : synthetic natural gas, propane - air, coke oven gas, refinery gas, biomass gas, air injected for btu stabilization, and manufactured gas commingled and distributed with natural gas. synthetic natural gas ( sng ) : ( also referred to as substitute natural gas ) a manufactured product, chemically similar in most respects to natural gas, resulting from the conversion or reforming of hydrocarbons that may easily be substituted for or interchanged with pipeline - quality natural gas. total storage field capacity : the maximum volume of natural gas ( including both base and working gas ) that can be stored in an underground storage facility in accordance with its design specifications, the physical characteristics of the reservoir, installed compression equipment, and operating procedures particular to the site. unaccounted for ( natural gas ) : represents differences between the sum of the components of natural gas supply and the sum of components of natural gas disposition. these differences maybe due to quantities lost or to the effects of data reporting problems. reporting problems include differences due to the net result of conversions of flow data meter


updated 04 : 40 pm est, fri march 9, 2012 findings could lead to 1, 000 - times faster 4g a research team at the university of pittsburgh has come up with a way to increase wireless data transmission speeds by a factor of thousands. headed up by hrvoje petek, a physics and chemistry professor at the university ' s dietrich school of arts and sciences, the team has reportedly created a " frequency comb " that includes over 100thz ( terahertz ) of bandwidth. it does so by " exciting a coherent collective of atomic motions in a semiconductor silicon crystal. " in other words, it divides a single color of light into a series of evenly spaced spectral lines. during their experiments, the team witnessed reflected light oscillating at 15. 6thz. in theory, this finding could one day allow smartphones and computers to transmit data in the terahertz frequency range. that electromagnetic spectrum sits between infrared and microwave light. modern devices are restricted to gigahertz frequency bandwidth signals. the team used silicon for the semiconductors in its experiments. the team believes they can upscale their work to achieve petahertz frequency range oscillations, of 1, 000 times faster again than what it managed to achieve already. [ via pcmag ]


of medical stress, headache, elevated blood pressure, anxiety and worker error rate. light trespass is defined as unwanted light crossing a property boundary ; or in the case of astonomical observation or the greater public good, light trespass may include the emission of sufficient atmopheric uplighting to interfere with celestial observation or to cause unwanted skyglow that interferes with evening scenery. in the case of light crossing a porperty boundary, the issues may include invasion of privacy, sleep interference or simply the uninvited presence of over - illumination. the matter of light intrusion across property lines is subject to local government ordinances that can limit light transmission across property boundaries, and to provide enforcement via the police poweres of cities and counties. numerous municipalities throughout the world have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. massive amounts of energy is wasted from over - illumination aspects of light pollution. in interior environments this excess use arises from : ( a ) illuminating work and living spaces with higher light intensities than required for functionality or aethestics ; ( b ) failure to deploy occupancy sensors or other methods of excluding unoccupied areas from illumination ; ( c ) use of aesthetically undesirable high levels of light, such as over - illumination of hallways and areas already illuminated by natural light ; and ( d ) failure to utilize daylight savings time in certain world regions. in the commercial world excessive energy use often arises when the one paying for energy use is not the same person who makes decisions about lighting. building managers and not building owners typically structure such tasks as janitorial lighting use, setting of timers, and even choice of lighting fixtures. another culprit is the structure of many commercial leases., where the tenant pays none of the electricity costs. architectural design can address many aspects of energy wastage by maximizing use of natural light, and carefully addressing specific light levels needed by work task and function. for example, modern office buildings often have large amounts of perimeter glazing, but usually fail to allow efficient use of this light by providing window tinting, adjustable shades or zonation of interior light banks that allow perimeter offices to have lights separately regulated from interior spaces, which lack abundant natural light. advanced techniques can be employed such as designing windows with optimum angles of exposure to sun azimuth, and overall siting and orientation of a new structure to take advantage of use of natural light for interior occupants. in outdoor venues, considerable light


computers and connected by a nation - wide network of bleeding - edge 1, 300 - baud modems, sage was the pinnacle of the united states ’ cold war radar and missile air defenses. ibm takes a step towards building artificial semiconductor synapses march 27, 2013 at 1 : 40 pm researchers at ibm have discovered a way to change the conductive properties of a metal oxide layer using an ionic fluid rather than a conventional electric charge. building artificial synapses may have just become a little easier. ibm makes watson the size of a pizza box, starts offering cloud access to doctors february 12, 2013 at 7 : 07 am ibm ’ s watson is smaller and sleeker than ever. killing silicon : inside ibm ’ s carbon nanotube computer chip lab february 5, 2013 at 9 : 22 am at ibm ’ s watson research center in upstate new york, some of the world ’ s best physicists, chemists, and nanoengineers are trying to create the first high - density, self - assembling carbon nanotube computer chip process. stanford researchers break million - core supercomputing barrier january 29, 2013 at 7 : 53 am in a world where quad - core computers are currently the norm, and eight - core processors available for purchase are somewhat rare, computers with more cores might a little unimaginable. a team at stanford has dwarfed that rare eight - core processor by using a supercomputer that employs over one million cores to solve a complex problem. ibm develops flexible nanocircuitry 10, 000 times thinner than paper january 15, 2013 at 3 : 30 pm this flexible circuit, roughly one ten - thousandth the thickness of a sheet of paper, is shaved off a wafer of silicon, and stuck onto a piece of plastic. not only is this a huge step forward for small and portable computing, but the incredibly tiny size means big things for increasing the horsepower of existing devices without needing substantially larger power resources. the origin of life and the future of computers january 15, 2013 at 7 : 30 am life ’ s crowning achievement, the human brain, seeks to mold for itself the power and directness of the computing machine, while endowing the machine with its own economy of thought and movement. to predict the form their inevitable convergence eventually might take, we can look back now with greater understanding to the early drivers which shaped the creation of life, and reinvigorate these ideas to guide our constructions today.


michaels, sarah, shouse, andrew w., schweingruber, heidi a.. " 4 organizing science education around core concepts. " ready, set, science! : putting research to work in k - 8 science classrooms. washington, dc : the national academies press, 2007. ingrades 3 - 5, the core concepts in atomic - molecular theory become more sophisticated. some of the core conceptsimportant to develop in these grades include understanding that : objects are made of matter that takes up space and has weight. solids, liquids, and gases are forms of matter and share these general properties. there can be invisible pieces of matter ( that is, too small to see with the naked eye ). matter continues to exist when broken into pieces too tiny to be visible. matter and mass are conserved across a range of transformations, including melting, freezing, and dissolving. although these concise statements summarize key aspects of the science, they do not reflect the ways in whichstudents express understanding of atomic - molecular theory. in fact, the student who simply memorizes or repeatsthese statements verbatim may very well understand little about the actual science behind them. students shouldbe able to describe these concepts in their own words in order to show their understanding, as the goal is for students to understand the core concepts behind the words. students in grades 3 - 5 continue to engage in a wide variety of scientific practices. they pose questions, makepredictions, design and conduct investigations, represent and interpret data, design models, and make argumentsthat support conclusions. furthermore, the scientific practices of older elementary school children become morecomplex in several ways. no longer reliant on mere sensory measures, and having established a theory of measure, they can now engage in more complicated forms of measuring and graphical representation. thus, studentsbuild on their understanding of area to explore the volume of rectangular solids, develop greater precision inmeasurement through more general understanding of fractional units, and construct graphs that show the relationbetween volume and mass instead of displaying each property separately. we ’ ll see several of these practices at work as we look at a third - grade classroom that is investigating theproperties of air. reggie figueroa ’ s third graders were carrying out a scientific investigation that involved weighing air. 7 in the previous weeks, they had weighed and measured different kinds of objects and materials, had predicted which objects would be heavier, and had graphed their results


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science is basically the combination of good logical reasoning with good practical knowledge of actual natural phenomena. all humans do some logical reasoning and have some practical knowledge of some actual natural phenomena, but most have to busy themselves with feeding themselves and their families as best they can. few have been able to devote much of their time to reasoning and / or gaining better knowledge of nature, and only some of these have made small or big contributions to science. in considering science theory, this site concentrates on physics theories from the now entirely untaught ideas of william gilbert, rene descartes and isaac newton to albert einstein and beyond - and we also have good related sections on galileo galilei, on johannes kepler, on gravity phenomena, on light, on string theory and physics now on the standard model, on probability science and on science philosophy. get this website as a zoomable, searchable and printable pdf ebook with helpful bookmarks - about £2 at new science theory pdf ebook our sitemap shows any sections updated since its 1. 1. 2012 ( or for £9 get the nice a4 paperback version at new science theory book ) physics news. the most powerful electromagnetic charged - particle accelerator built to date was switched on in 2008 at cern, and this £5 billion large hadron collider ( lhc ) has been smashing electrically charged protons and charged heavy atom nuclei into each other at energies much greater than any achieved before. the lhc machine housed in an underground 27 kilometre ( 17 mile ) tunnel is for accelerating ' atom - smashing ' experiments that since the 1950 ' s have somehow attracted the majority of modern funding for experimental physics. charged particle beams are being electromagnetically accelerated in opposite directions through the ring - shaped machine, cooled to just 1. 9 degrees above absolute zero ( minus 271c ), to velocities up to maybe 99. 99 % of the speed of light?! the electrically charged particle beams ' collide ' in four detectors, designed like giant microscopes but still not capable of observing any actual collision contact. supporters of a variety of physics theories hope that its experiments may support their theory. initial analyses of lhc experiments to 2012 seem to be ruling out some multi - dimension theories, some sub - quark particles theories, some string theories and some supersymmetry - sparticles theories. ( see http : / / physicsworld. com / cws / article / indepth / 44805 ) and the near - light speeds have maybe not shown expected einsteinian effects. cern


##symmetry - sparticles theories. ( see http : / / physicsworld. com / cws / article / indepth / 44805 ) and the near - light speeds have maybe not shown expected einsteinian effects. cern reported 4 july 2012 that lhc teams ' have discovered a new particle consistent with the standard model predicted higgs boson '. more research is needed to prove if the new 125gev particle actually is the higgs boson, probably not before 2015, but many physicists including peter higgs have rushed to claim it proved. more experiments and analyses are to come, and no doubt more generally useless ' physics theories '. many of these modern physics theories are illdefined and some do not really cover electromagnetism and are varieties of push - physics only though it remains unproved if gravity, electromagnetism or ' collision ' involve any push - contact. the cern lhc has already produced mini - big - bangs and some hope that it may also produce mini - black - holes, and some see its present 7tev as its maximum safe power though by 2015 it will be run at 14tev to prevent it being outdone by newer atom - smashers like the t2k neutrino collider. and you have to wonder if modern physics has been seriously dumbed - down as 2009 saw two physicists claiming that ' the lhc was disabled by a bird from the future ' - discussed in our science history section. november 2012 sees some modern ' mainstream physicists ' now pushing to abolish the teaching of classical experimental physics in schools as ' obsolete '. they want the experiments by newton on light, by galileo on gravity and by gilbert on magnetics / electrics to be deleted from human history. it seems that only modern thought - experiment mathematical physics, or conjectural - physics, should be taught. this is being pushed at the us president through youtube in a video " open letter to the president : physics education ", which seems to be from the ' perimeter institute for theoretical physics ' of canada. the physicist or physicists concerned were obviously taught classical physics at school in the awful way it is always taught now, with no study of the works of newton, galileo and gilbert. this attempt at killing real experimental physics and its associated theories can be seen on youtube at http : / / www. youtube. com / watch? v = bgl22ptioam those who have specialised only in logical reasoning have often been


discovery that the originally supposed elementary particles ' atoms ' seemed basically mini - solar - systems with smaller particles and mini - action - at - a - distance. strong evidence that solids are far from solid supported the conclusion that at least some ' pushes ' may not be contact pushes and so maybe at least partly supports either a field type physics or a signal type physics where signals establish contact but do no pushing? after newton, physics theory seems to have somewhat sidelined experimental study in favour of mathematical study, so that increasingly universities located theoretical physics in their mathematics departments rather than in physics departments. and certainly new physics theory since einstein, such as ' string ' and ' loop ' theory, seems to largely have been on the mathematics and structure of fields and / or of ' elementary ' particles as possibly explaining everything somehow though it perhaps is muddy water - and ' fields ' may yet be shown to not exist and / or the ' elementary particles ' may yet be shown to be mini - mini - solar - systems themselves. in physics the big may be as reasonable a model of the small as vice versa, or not, and a signal physics may yet prove of some use also. many have been involved in the development of science, and many more in supporting or opposing it, covering all countries. but the key science theory ideas around physics can perhaps best be seen by going backwards from einstein. einstein considered that the theory that he chiefly had to face up to was newton ' s, and newton considered that the theories that he chiefly had to face up to were descartes ' and gilbert ' s. few understood newton ' s evaluation of gilbert, but it seems the key physics theories were indeed those of gilbert, descartes, newton and einstein which this site examines further on other pages in an interrelated way rather than entirely separately. on this site you can start with william gilbert and somewhat simpler early physics theories and journey on to rather more complex modern physics theories. while newton considered various possible explanations of gravity and other ' forces ', he ended up supporting none and insisting that physics should support none. he concluded that black - box mathematical behaviour laws were enough for science, and that any explanation must involve untestible unseens and be ' outside science '. this basic conclusion of newton can certainly be challenged, but einstein and others ignoring it and claiming newton ' s theory was a simple billiard ball push theory was one of the worst mistakes in physics theory history. it meant that no physicist has worked from or built on newton ' s actual physics position - only on a


and others ignoring it and claiming newton ' s theory was a simple billiard ball push theory was one of the worst mistakes in physics theory history. it meant that no physicist has worked from or built on newton ' s actual physics position - only on a simplified false ' newton position '? and although gilbert, descartes and newton took science as not allowing contradictions, einstein and others later adopted ' duality physics ' for light and for particles requiring them both to be ' wave ' and be ' not - wave ' and so allowing contradiction in their science. not just allowing contrary interpretations and contrary mathematics, but allowing actual contradiction in experiments and in actual nature. this became possible by rejecting earlier strict definitions of ' wave ' and ' particle ' and basically using no strict definitions. the interest of gilbert and newton in signal physics theory was perhaps before its time and has really been developed by nobody since. and they were less interested in the physical nature of any signal emissions, be they particle emissions or energy emissions or wave emissions, than in how bodies experimentally responded to natural signals. some modern physicists are now talking of a ' quantum - information ' physics, a ' quantum computation ' physics or a ' digital ' physics involving maybe a ' cellular automaton universe ' - including among others pablo arrighi and jonathan grattage affiliated with the university of grenoble and ens de lyon, france ( see http : / / membres - lig. imag. fr / arrighi / ). and the possible relevance in physics still of gilbert - newton ' attraction physics ' is maybe also suggested by a recent quote of google on them letting application developers for their android phones use c or c + + code " as in signal processing, intensive physics simulations, and some kinds of data processing ". it is maybe of some small interest that einstein was the only one of these four major scientists to marry, suggesting that having a family to feed or other major activities can hinder the development of substantial new science!? but more positive is the fact they all seem to have retained their mental capacities well in old age - maybe an old - age iq fall from 100 to 95 gives poor mental functioning but an iq fall from 165 to 160 still leaves excellent mental functioning when older? the ideas presented on this site are based on extensive studies of william gilbert and of much of descartes, newton and einstein and others relating to their theories. currently the internet offers little of these four to read online, and much of their work has still not been translated


may still validly allow of different image - theory explanations. but a one - truth science does not seem to really allow of contradictory explanations such as duality theory in current physics? while we do consider science theory generally, this site is the very best at examining the fundamentals of physics, and at considering the more important new discoveries in physics and physics projects. if you want to really learn physics then this website really helps people with mastering physics online, and can also point you to some of the best physics ebooks online. ps. some might say that the last 50 years has maybe seen no significant new physics theory published, and maybe generally business and government hijack any new science to their own ends anyway, leaving little real value to any new science? but i have been sitting on a new general science theory for the last 40 years developed after the first bsc degree i took. then for a second bsc degree when i took year 1 philosophy, i part ran it past the professor of philosophy who had been a physicist, in a 1985 essay for him on the history of physics. he gave that top marks and promptly made several attempts to get me to switch to majoring in philosophy under him ( which i would have done but at that time i could not see it as a practical career option for feeding my new wife and baby ). but being satisfied that the basics of my new general science theory may possibly be worth at least a temporary publishing rather than just all dying with me, i have now put the basics of it on this website - in the hope that you may find it interesting ( and this website is all interrelated so studying all of it should help you understand it ). additionally, this site simply tries to clarify some of the basics of science theory history to date as i see it - though many do interpret science history differently and often very wrongly. some of the problems involved in the history of science are discussed in our science history, or you can check our site map. you can do a good search of this website, or of the web, below ; or two websites to slightly help inform you on what physicists and astronomers are up to lately are physics world at http : / / physicsworld. com / and universe today at http : / / www. universetoday. com / get our first android science news app - ' new science info ' - in the google play app store for news on science. and now our second android gravity app - ' sun pull ' - is also in the google play app store to help you re


abstract index notation is a mathematical notation for tensors that uses indices to indicate their types, rather than their components in a particular basis. the indices are mere placeholders, not related to any fixed basis, and in particular are non - numerical. the notation was introduced by roger penrose as a way to use the formal aspects of the einstein summation convention in order to compensate for the difficulty in describing contractions and covariant differentiation in modern abstract tensor notation, while preserving the explicit covariance of the expressions involved. let v be a vector space, and v * its dual. consider, for example, a rank 2 covariant tensor h ∈ v * ⊗ v *. then h can be identified with a bilinear form on v. in other words, it is a function of two arguments in v which can be represented as a pair of slots : abstract index notation is merely a labelling of the slots by latin letters, which have no significance apart from their designation as labels of the slots ( i. e., they are non - numerical ) : a contraction between two tensors is represented by the repetition of an index label, where one label is contravariant ( an upper index corresponding to a tensor in v ) and one label is covariant ( a lower index corresponding to a tensor in v * ). thus, for instance, is the trace of a tensor t = tabc over its last two slots. this manner of representing tensor contractions by repeated indices is formally similar to the einstein summation convention. however, as the indices are non - numerical, it does not imply summation : rather it corresponds to the abstract basis - independent trace operation ( or duality pairing ) between tensor factors of type v and those of type v *. abstract indices and tensor spaces a general homogeneous tensor is an element of a tensor product of copies of v, such as label each factor in this tensor product with a latin letter in a raised position for each contravariant v factor, and in a lowered position for each covariant v * position. in this way, write the product as it is important to remember that these last two expressions signify precisely the same object as the first. we shall denote tensors of this type by the same sort of notation, for instance in general, whenever one contravariant and one covariant factor occur in a tensor product of spaces, there is an associated contraction ) map. for instance, is the trace on the first two spaces


cd media, dvd media, tape media cd - rom ( which stands for " compact disc read - only memory " ) is a compact disc ( cd media ) that contains data accessible by a computer. while the compact disc format was originally designed for music storage and playback, the format was later adapted to hold any form of binary data. cd - roms ( including cd r and cd rw ) are popularly used to distribute computer software, games, multimedia content, mp3, and much more, though any data can be stored ( up to the capacity limit of a disc ). some cds hold both computer data and audio with the latter capable of being played on a cd player, while the data ( such as software or digital video ) is only usable on a computer ( with cd - rom or dvd drive ). these are called enhanced cds. prerecorded cd - rom discs are identical in appearance to audio cds, and data is stored and retrieved in a very similar manner ( only differing from audio cds in the standards used to store the data ). discs are made from a 1. 2 mm thick disc of polycarbonate plastic, with a thin layer of aluminum to make a reflective surface. the most common size of cd - rom disc is 120 mm in diameter, though the smaller mini cd standard with an 80 mm diameter, as well as numerous non - standard sizes and shapes ( e. g. business card - sized media ) are also available. recordable formats, such as cd - r and cd - rw allow a computer to record directly on the cd. another variation on the cd is the dvd, and is the most popular optical disc storage media format for movies. its main uses are video and data storage. most dvd media are of the same dimensions as compact discs ( cds ) but store more than 6 times as much data. variations of the term dvd often describe the way data is stored on the discs : dvd - rom has data which can only be read and not written, dvd r ( dvd - r and dvd + r ) can be written once and then functions as a dvd - rom, and dvd rw ( dvd - ram, dvd - rw, or dvd + rw ) holds data that can be erased and thus re - written multiple times. dvd - video and dvd - audio discs respectively refer to properly formatted and structured video and audio content. other types of dvd discs, including those with video content, may be referred to as dvd - data discs. the term " dvd " is commonly misused


very different from one authentication to the next. the one - time password algorithm makes use of the sha - 1 cryptographic hash algorithm. this algorithm produces a digest of 160 bits. by today ’ s internet standards, sha - 1 is considered old. it was developed by ronald l. rivest and published as a standard in 1995. is sha - 1 still adequate to create one - time passwords? let ’ s consider the problem that an attacker must solve to break the one - time password system. assume an attacker knows the sha - 1 digest of frank ’ s last logon attempt. the attacker could now try to find a message that matches the observed digest. indeed, knowing the message implies knowing a value of frank ’ s secret and the counter. such an attack is called a pre - image attack. fortunately, for sha - 1, there are no known ( published ) pre - image attacks that are more efficient than brute force trying all possible messages. it ’ s easy to see that this requires an astronomical number of messages values. for a 160 - bit digest, the attacker can expect to test on the order of 2160 messages. therefore it ’ s reasonable to conclude that sha - 1 is adequate for the one - time password algorithm. note, however, that this does not imply that sha - 1 is adequate for any application. in another attack model, cryptographers worry about collisions, the possibility of an attacker finding a pair of messages that generate the same digest. for such attacks on sha - 1, significant progress has been made in recent years. the one - time password scheme in figure 1 combines two inputs into a single digest : a secret key and a counter value. to combine a static, secret key with a variable message, cryptographers use a keyed hash. the digest of a keyed hash is called a message authentication code ( mac ). it can be used to verify the identity of the message sender. figure 2 shows how sha - 1 is used in a hash - based message authentication code ( hmac ) construction. sha - 1 is applied twice. the first sha - 1 input is a combination of the secret key and the input message. the resulting digest is combined again with the secret key, and sha - 1 is then used to compute the final mac. each time, the secret key is mapped into a block of 512 bits. the first time, it is xored with a constant array of 64 copies of the value 0×36. the second time, it is xored with a


electrodynamics / dipoles and multipoles in the previous sections of the book, charges and charge distributions have been treated in a general fashion. in this section of the book, we will allow for ordered charge configurations of which molecular matter is actually comprised of. for the most part, ordinary matter is electrically neutral, but it is highly saturated with pairs of charges called dipoles. for us, dipoles will be the building blocks of dielectric and magnetic materials. an electric monopole is a single charge, and a dipole is two opposite charges closely spaced to each other, or something which looks like that electrically. dipoles are actually very abundant in nature. for example, a water molecule has a large permanent electric dipole moment. its positive and negative charges are not centered at the same point ; it behaves like like two equal and opposite charges separated by a small distance. another occurrence happens to uncharged pith balls. in presences of a charged object, the uncharged pith ball will be attracted to the charged object because the little dipoles have responded to the electric field of the rod. the electric potential due to a dipole as it turns out, it is better mathematically to not think of dipoles as a collection of positive and negative charges but as a separate object all together. take a moment and imagine two opposite charges with magnitude q and they are separated by a small distance s. the question to ask then is, what is the potential at some distance r away from the configuration? last modified on 26 may 2011, at 20 : 38


hidden field equations | | this article may require cleanup to meet wikipedia ' s quality standards. ( january 2009 ) | hidden fields equations ( hfe ) is a public key cryptosystem which was introduced at eurocrypt in 1996 and proposed by ( french ) jacques patarin following the idea of the matsumoto and imai system. hfe is also known as hfe trapdoor function. it is based on polynomials over finite fields of different size to disguise the relationship between the private key and public key. hfe is in fact a family which consists of basic hfe and combinatorial versions of hfe. the hfe family of cryptosystems is based on the hardness of the problem of finding solutions to a system of multivariate quadratic equations ( the so called mq problem ) since it uses private affine transformations to hide the extension field and the private polynomials. hidden field equations also have been used to construct digital signature schemes, e. g. quartz and sflash. one of the central notions to understand how hidden field equations work is to see that for two extension fields over the same base field one can interpret a system of multivariate polynomials in variables over as a function by using a suitable basis of over. in almost all applications the polynomials are quadratic, i. e. they have degree 2. we start with the simplest kind of polynomials, namely monomials, and show how they lead to quadratic systems of equations. let us consider a finite field, where is a power of 2, and an extension field. let to be a basis of as an vector space. let such that for some and gcd and take a random element. we represent with respect to the basis as. define by the condition gcd is equivalent to requiring that the map on is one to one and its inverse is the map where is the multiplicative inverse of. choose two secret affine transformation, i. e. two invertible matrices and with entries in and two vectors and of length over and define and via : let be the matrix of linear transformation in the basis such that for. write all products of basis elements in terms of the basis, i. e. : for each. the system of equations which is explicit in the and quadratic in the can be obtain by expanding ( 1 ) and equating to zero the coefficients of the. by using the affine relations in ( 2 ) to replace the with, the system of equations is linear in the and of degree 2


quadratic in the can be obtain by expanding ( 1 ) and equating to zero the coefficients of the. by using the affine relations in ( 2 ) to replace the with, the system of equations is linear in the and of degree 2 in the. applying linear algebra it will give explicit equations, one for each as polynomials of degree 2 in the. the basic idea of the hfe family of using this as a multivariate cryptosystem is to build the secret key starting from a polynomial in one unknown over some finite field ( normally value is used ). this polynomial can be easily inverted over, i. e. it is feasible to find any solutions to the equation when such solution exist. the secret transformation either decryption and / or signature is based on this inversion. as explained above can be identified with a system of equations using a fixed basis. to build a cryptosystem the polynomial must be transformed so that the public information hides the original structure and prevents inversion. this is done by viewing the finite fields as a vector space over and by choosing two linear affine transformations and. the triplet constitute the private key. the private polynomial is defined over. the public key is. below is the diagram for mq - trapdoor in hfe the private polynomial with degree over is an element of. if the terms of polynomial have at most quadratic terms over then it will keep the public polynomial small. the case that consists of monomials of the form, i. e. with 2 powers of in the exponent is the basic version of hfe, i. e. is chosen as the degree of the polynomial is also known as security parameter and the bigger its value the better for security since the resulting set of quadratic equations resembles a randomly chosen set of quadratic equations. on the other side large slows down the deciphering. since is a polynomial of degree at most the inverse of, denoted by can be computed in operations. encryption and decryption the public key is given by the multivariate polynomials over. it is thus necessary to transfer the message from in order to encrypt it, i. e. we assume that is a vector. to encrypt message we evaluate each at. the ciphertext is. to understand decryption let us express encryption in terms of. note that these are not available to the sender. by evaluating the at the message we first apply, resulting in. at this point is transferred from so we can apply the private


. to understand decryption let us express encryption in terms of. note that these are not available to the sender. by evaluating the at the message we first apply, resulting in. at this point is transferred from so we can apply the private polynomial which is over and this result is denoted by. once again, is transferred to the vector and the transformation is applied and the final output is produced from. to decrypt, the above steps are done in reverse order. this is possible if the private key is known. the crucial step in the deciphering is not the inversion of and but rather the computations of the solution of. since is not necessary a bijection, one may find more than one solution to this inversion ( there exist at most d different solutions since is a polynomial of degree d ). the redundancy denoted as is added at the first step to the message in order to select the right from the set of solutions. the diagram below shows the basic hfe for encryption. hidden field equations has four basic variations namely +, -, v and f and it is possible to combine them in various way. the basic principle is the following : - 01. the + sign consists of linearity mixing of the public equations with some random equations. - 02. the - sign is due to adi shamir and intends to remove the redundancy ' r ' of the public equations. - 03. the f sign consists of fixing some input variables of the public key. - 04. the v sign is defined as a construction and sometimes quite complex such that the inverse of the function can be found only if some v of the variables called vinegar variables are fixed. this idea is due to jacques patarin. the operations above preserve to some extent the trapdoor solvability of the function. hfe - and hfev are very useful in signature schemes as they prevent from slowing down the signature generation and also enhance the overall security of hfe whereas for encryption both hfe - and hfev will lead to a rather slow decryption process so neither too many equations can be removed ( hfe - ) nor too many variables should be added ( hfev ). both hfe - and hfev were used to obtain quartz. there are two famous recent attacks on hfe : 01. shamir - kipnis : recover the private key. the key point of this attack is to recover the private key as sparse univariate polynomials over the extension field. the attack only works for basic


famous recent attacks on hfe : 01. shamir - kipnis : recover the private key. the key point of this attack is to recover the private key as sparse univariate polynomials over the extension field. the attack only works for basic hfe and fails for all its variations. 02. faugere : fast grobner bases. the idea of faugere ' s attacks is to use fast algorithm to compute a grobner basis of the system of polynomial equations. faugere broke the hfe challenge 1 in 96 hours in 2002 and in 2003 faugere and joux worked together on the security of hfe. - christopher wolf and bart preneel, asymmetric cryptography : hidden field equations - nicolas t. courtois on multivariate signature - only public key cryptosystems - ilia toli hidden polynomial cryptosystems - jean charles faugere and antoine joux, algebraic cryptanalysis of hidden field equations ( hfe ) cryptosystems using grobner bases - nicolas t. courtois, " the security of hidden field equations " - jacques patarin, hidden field equations ( hfe ) and isomorphic polynomial ( ip ) : two new families of asymmetric algorithm read in another language this page is available in 1 language


fluid. if the ion is moved faster, its mechanical resistance rises even faster. the mechanical resistance rises as the square of the speed. this means that if the speed is doubled, the resistance is 2×2 which gives a value of 4. and if the speed rises by a factor of 3 the mechanical resistance rises by 3×3 which is 9. this effect can be felt if one moves the hand slow and fast through water. as a consequence the ions conducting the current in the body experience a higher mechanical resistance if moved at higher frequencies as compared to lower frequencies. if the high frequency signal is asymmetric, meaning that the positive component of the sine wave has a different frequency as the negative component, the ion experiences two different mechanical resistances as well. since the energies of both components of the signal are equal, the ions are moved back and forth by the asymmetric field. but because of the lower mechanical resistance during slow movement they move a bit further in the direction enforced by of the lower frequency component. this is illustrated with a dvd being moved through water in the film 4 strahlenwaffen. such an asymmetric electromagnetic field can be generated with frequencies up to many ghz by fast synthesizers. these asymmetric high frequency fields are causing ionic electric currents which can simulate nerve pulses in the body. this techniques are used for brainwashing as well. if the parts of the brain which are passing the nerve signal from the ear to the brain are irradiated with such a speech modulated signal, the resulting voice is not being heard, as it is not coming from the ear. but it is not being thought either as it is not coming from inside the brain. that can make it difficult to decide whether specific thoughts or opinions are the result of brainwashing. especially if one is not aware of this possibility. brainwashing can be suspected if opinions or thoughts are openly false or even lead to dangerous behavior like taking drugs, drinking and smoking. suitably speech modulated electromagnetic fields are perceived as being heard or thought by certain brain regions involved in hearing. in a similar way the regions of the brain responsible for seeing can be stimulated by electromagnetic fields. the question arises to what extend this can be used. it is known that every point on the surface of the body corresponds to another point on the surface of the brain with regard to feeling, hearing and seeing. the surface of the brain is, so to speak, an image of the surface of the body with regard to data processing. points being close together on


body corresponds to another point on the surface of the brain with regard to feeling, hearing and seeing. the surface of the brain is, so to speak, an image of the surface of the body with regard to data processing. points being close together on the surface of the body or the retina are as well close together in the respective region of the brain. the region responsible for seeing is situated in the backof the skull, right over the neck and named visual cortex. this opens the possibility to stimulate this region of the brain with laser using the techniques described in detail elsewhere in this text. a high resolution low frequency or asymmetric electromagnetic field being produced by heterodyning of two laser beams is used to scan the surface of the visual cortex. on its way over the brain surface it stimulates the nerves to cause the impression of seeing. and thus “ write ” a picture or a film onto the visual cortex. there are two major obstacles to simply “ write ” a picture onto the brain. the first is that the structure and organization of every brain is a little different. the second is that the surface of the visual cortex is quite large and as a consequence is bent to fit into the scull resulting in a three dimensional structure. the laser has to write the picture without the computer exactly knowing which part of the brain surface is matching a given point on the retina. this problem certainly would result in a distorted picture being “ seen ”. with modern computer techniques, matching a picture or a film to the bent surface of the brain, it is possible to write an exact picture onto the brain. the difficulty is to know which point on the brain corresponds to which point on the retina. this demands a possibility to calibrate the laser weapons. but how can the brain, the retina and nerves in general be tapped with a sufficient high resolution at some distance? if a microwave signal is interacting with a low frequency signal such as is occurring in a nerve, both are heterodyning. this heterodyning causes signals with the frequencies microwave + nerve signal and another one microwave - nerve signal. as these resulting signals are microwave signals as well, they are radiating from the nerve and can be received at some distance, allowing direct measurement of the electric activity of the nerves. the voltage of a nerve pulse measures about 50 to 100 millivolts. there are electronic circuits for transmitters operating with 600 millivolt and even less. these of course only have a short range of maybe 10 or 20 meters. however, the alternating voltage


or 12 years certainly knew a little more despite giving a false location for the visual cortex. state of the art according to the techniques published, one would expect a high resolution laser beam being split into two. one of these laser beams would run through a pockels cell where a synthesizer generated microwave signal would be added. this microwave signal would be asymmetric. additionally it would be a spread spectrum signal, meaning that its frequency would change very fast over several ghz. the interaction of these two laser beams produces beats in the microwave range. as a result we have a high resolution and highly directional beam of an asymmetric electromagnetic field in the microwave range which then produces a low frequency current which can imitate the natural currents of the nerves. the target area is then scanned with this high resolution beam. such beats in the microwave range penetrate an obstacle just like any radio frequency signal of the same frequency. with this technique it is quite difficult to directly measure the beam due to the spread spectrum signal. even with the proper measuring equipment it should be possible to shoot right around the sensors due to the very high resolution achievable with a laser. other possibilities are jamming the sensors or using additional laser radiation which causes destructive interference of the electromagnetic waves within the sensor, nulling theeffect of the laser signal on this sensor. promising could be direct measurement of the currents on the surface, or better by electrodes within the body and comparing them with the natural body currents. another possibility could be to use additional radiation of one or several suitable wavelengths which then interact with the radiation of the laser weapon to produce either beats or harmonics in a spectrum visible to the eye or cameras. a little bit of smoke would then reveal the path and origin of such a radiation used as weapon. the generation of beats or harmonics can be used in shielding techniques as well. if additional radiation of a suitable wave length is overlaying or heterodyning the relatively low frequency beats of a laser weapon, harmonics can be generated in a frequency range which can not penetrate a certain barrier. an electromagnetic field causes atoms and molecules to move in time with the field. if the frequency of the electromagnetic field is low this movement of the atoms is slow as well, consuming relatively little of the energy being transmitted by the electromagnetic field. this allows microwave signals as well as electromagnetic beats in the microwave range to if high frequency, for example infrared radiation, is overlaying the low frequency microwave signal, this heterodyning causes harmonics in the infrared region. these high


field. this allows microwave signals as well as electromagnetic beats in the microwave range to if high frequency, for example infrared radiation, is overlaying the low frequency microwave signal, this heterodyning causes harmonics in the infrared region. these high frequency electromagnetic harmonics, like infrared radiation, are moving the atoms and molecules in time with their high frequency. these fast movements of atoms and molecules enforced by the harmonics or electromagnetic radiation are consuming the energy very fast, resulting in the radiation being shielded by converting it into heat. the same physical principles are used for surveillance as well. the resolution achievable with laser radar techniques using infrared and visible light can be evaluated with regard to data storage on cd - rom and dvd. using heterodyning it is possible to penetrate one or several barriers. the use of uv - lasers allows a much higher resolution, making it possible to read cd - roms and dvds at quite some distance, especially if they are positioned in a way exposing the optical layer to the laser. stacks of many may be read without any problem. this makes possible to let organizations being interested in certain information, say voice or film recordings showing victims being tortured, to have a look at it and still being able to plausibly deny any knowledge. however, the material is archived somewhere. and the cia / nsa / fbi certainly does not want this. and consequently may back off from torturing a person. otherwise … film it, burn it and expose it. the application to steering, brainwashing techniques and torture. during steering the contraction of the muscles of the torturer is being measured with radar techniques. the contraction of the muscles of the torture victim is measured with radar techniques as well. then electrical pulses are transmitted by laser or microwave techniques into the muscles of the torture victim till the muscles of both persons are contracted likewise, resulting in synchronous movements including speech. being steered results in exactly following the movements of the person steering and saying what this person says. beating as it is frequently shown in the films requires purposeful movements of the body. these movements can be steered as described by a cia / nsa / fbi official or by a person ’ s own brain. brainwashing of course does not steer the muscles. accordingly target is not beating during brainwashing and mood management as this requires deliberate and purposeful aimed movements of the body, not only enforced “ thoughts ” of any kind. brainwashing is done by converting voice into suitable electrical pulses. with theses pulses laser or microwave radiation is


by als beamlines 18. 104. 22. 168, a resonant soft x - ray scattering ( r - soxs ) facility ; 7. 3. 3, a small - and wide - angle x - ray scattering ( saxs / waxs / ) end - station ; and 5. 3. 2, an end - station for scanning transmission x - ray microscopy ( stxm ). says collins, the first author on the advanced energy materials paper, “ the combination of these three als beamlines enabled us to obtain comprehensive pictures of polymer - based organic photovoltaic film morphology from the nano - to the meso - scales. until now, this information has been unattainable. ” the international team used the trifecta of als beams to study the polymer / fullerence blend ptb7 : pc71bm in thin films made from chlorobenzene solution with and without the addition ( three - percent by volume ) of the solvent diiodooctane. the films were composed of droplet - like dispersions in which the dominant acceptor domain size without the additive was about 177 nanometers. the addition of the solvent shrank the acceptor domain size down to about 34 nanometers while preserving the film ’ s composition and crystallinity. this resulted in an efficiency gain of 42 - percent. “ in showing for the first time just how pure and how large the acceptor domains in organic solar devices actually are, as well as what the interface with the donor domain looks like, we ’ ve demonstrated that the impact of solvents and additives on device performance can be dramatic and can be systematically studied, ” ade says. “ in the future, our technique should help advance the rational design of polymer - based organic photovoltaic films. ” this research was primarily supported by the doe office of science, which also supports the als. lawrence berkeley national laboratory addresses the world ’ s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. founded in 1931, berkeley lab ’ s scientific expertise has been recognized with 13 nobel prizes. the university of california manages berkeley lab for the u. s. department of energy ’ s office of science. for more, visit www. lbl. gov. doe ’ s office of science is the single largest supporter of basic research in the physical sciences in the united states, and is working to address some of the most pressing challenges of our time.


in 1985 klaus von klitzing won the nobel prize for discovery of the quantised hall effect. the previous nobel prize awarded in the area of semiconductor physics was to bardeen, shockley and brattain for invention of the transistor. everyone knows how important transistors are in all walks of life, but why is a quantised hall effect significant? 100 years ago e. h. hall discovered that when a magnetic field is applied perpendicular to the direction of a current flowing through a metal a voltage is developed in the third perpendicular direction. this is well understood and is due to the charge carriers within the current being deflected towards the edge of the sample by the magentic field. equilibrium is achieved when the magnetic force is balanced by the electrostatic force from the build up of charge at the edge. this happens when ey = vxbz. the hall coefficient is defined as rh = and since the current density is jx = vxnq, rh = 1 / nq in the case of a single species of charge carrier. rh can thus be measured to find n the density of carriers in the material. often this transverse voltage is measured at fixed current and the hall resistance recorded. it can easily be seen that this hall resistance increases linearly with magnetic field. in a two - dimensional metal or semiconductor the hall effect is also observed, but at low temperatures a series of steps appear in the hall resistance as a function of magnetic field instead of the monotonic increase. what is more, these steps occur at incredibly precise values of resistance which are the same no matter what sample is investigated. the resistance is quantised in units of h / e2 divided by an integer. this is the quantum hall effect. the figure shows the integer quantum hall effect in a gaas - gaalas heterojunction, recorded at 30mk. the qhe can be seen at liquid helium temperatures, but in the millikelvin regime the plateaux are much wider. also included is the diagonal component of resistivity, which shows regions of zero resistance corresponding to each qhe plateau. in this figure the plateau index is, from top right, 1, 2, 3, 4, 6, 8.... odd integers correspond to the fermi energy being in a spin gap and even integers to an orbital ll gap. as the spin splitting is small compared to ll gaps, the odd integer plateaux are only seen at the highest magnetic fields. important points to note are :


to the fermi energy being in a spin gap and even integers to an orbital ll gap. as the spin splitting is small compared to ll gaps, the odd integer plateaux are only seen at the highest magnetic fields. important points to note are : the zeros and plateaux in the two components of the resistivity tensor are intimately connected and both can be understood in terms of the landau levels ( lls ) formed in a magnetic field. in the absence of magnetic field the density of states in 2d is constant as a function of energy, but in field the available states clump into landau levels separated by the cyclotron energy, with regions of energy between the lls where there are no allowed states. as the magnetic field is swept the lls move relative to the fermi energy. when the fermi energy lies in a gap between lls electrons can not move to new states and so there is no scattering. thus the transport is dissipationless and the resistance falls to zero. the classical hall resistance was just given by b / ne. however, the number of current carrying states in each ll is eb / h, so when there are i lls at energies below the fermi energy completely filled with ieb / h electrons, the hall resistance is h / ie2. at integer filling factor this is exactly the same as the classical case. the difference in the qhe is that the hall resistance can not change from the quantised value for the whole time the fermi energy is in a gap, i. e between the fields ( a ) and ( b ) in the diagram, and so a plateau results. only when case ( c ) is reached, with the fermi energy in the landau level, can the hall voltage change and a finite value of resistance appear. this picture has assumed a fixed fermi energy, i. e fixed carrier density, and a changing magnetic field. the qhe can also be observed by fixing the magnetic field and varying the carrier density, for instance by sweeping a surface gate. although it might be thought that a perfect crystal would give the strongest effect, the qhe actually relies on the presence of dirt in the samples. the effect of dirt and disorder can best be though of as creating a background potential landscape, with hills and valleys, in which the electrons move. at low temperature each electron trajectory can be drawn as a contour in the landscape. most of these contours encircle hills or valleys so do not transfer an electron from one side of


with hills and valleys, in which the electrons move. at low temperature each electron trajectory can be drawn as a contour in the landscape. most of these contours encircle hills or valleys so do not transfer an electron from one side of the sample to another, they are localised states. a few states ( just one at t = 0 ) in the middle of each ll will be extented across the sample and carry the current. at higher temperatures the electrons have more energy so more states become delocalised and the width of extended states increases. the gap in the density of states that gives rise to qhe plateaux is the gap between extended states. thus at lower temperatures and in dirtier samples the plateaus are wider. in the highest mobility semiconductor heterojunctions the plateaux are much narrower. in very high mobility samples extra plateaux appear between the regular quantum hall plateaux, at resistances given by h / e2 divided by a rational fraction p / q instead of an integer. this is the fractional quantum hall effect ( fqhe ). early observations found that q was always an odd number and that certain fractions gave rise to much stronger features than others. the fqhe is much more difficult to explain since it originates from many electron correlations, but for this reason has been of great interst to theoreticians and experimentallists alike. in some materials there are more than one species of charge carrier. these may be elecrons in different conduction band minima, different spatially confined subbands or electrons and holes simultaneously present. the numbers and mobilities of all the species have to be considered to find the transport coefficients. if there are electrons and holes the total filling factor is the difference between the filling factors for electrons and holes. at certain fields this can be zero, at which point the hall resistance itself becomes zero! last updated 05 / 02 / 97 by david r leadley. all rights reserved. text and diagrams from this page may only be used for non - profit making academic excerises and then only when credited to d. r. leadley, warwick university 1997.


depth charge : using atomic force microscopy to study subsurface structures for immediate release : june 23, 2010 contact : michael baum over the past couple of decades, atomic force microscopy ( afm ) has emerged as a powerful tool for imaging surfaces at astonishing resolutions — fractions of a nanometer in some cases. but suppose you ' re more concerned with what lies below the surface? researchers at the national institute of standards and technology ( nist ) have shown that under the right circumstances, surface science instruments such as the afm can deliver valuable data about sub - surface conditions. their recently published * work with colleagues from the national aeronautics and space administration ( nasa ), national institute of aerospace, university of virginia and university of missouri could be particularly useful in the design and manufacture of nanostructured composite materials. engineers are studying advanced materials that mix carbon nanotubes in a polymer base for a wide variety of high - performance applications because of the unique properties, such as superior strength and electrical conductance, added by the nanotubes. the material chosen by the research team as their test case, for example, is being studied by nasa for use in spacecraft actuators because it may outperform the heavier ceramics now used. but, says nist materials scientist minhua zhao, " one of the critical issues to study is how the carbon nanotubes are distributed within the composite without actually breaking the part. there are very few techniques available for this kind of non - destructive study. " zhao and his colleagues decided to try an unusual application of atomic force microscopy. the afm is actually a family of instruments working on the same basic principal : a delicate needle - like point hovers just above the surface to be profiled and responds to weak, atomic - level forces. a typical afm senses so - called " van der waals forces, " very short - range forces exerted by molecules or atoms. this restricts the instrument to the surface of samples. instead, the team used an afm designed to use the stronger, longer - range electrostatic force ( technically an efm ), measuring the interaction between the probe tip and a charged plate beneath the composite sample. what makes it work, says zhao, is that the nanotubes are electrical conductors with high dielectric constant ( a measure of how the material affects an electric field ), but the polymer is a low dielectric constant material. such huge dielectric constant differences between nanotubes and the polymer is the key to the success of this technique, and


( a measure of how the material affects an electric field ), but the polymer is a low dielectric constant material. such huge dielectric constant differences between nanotubes and the polymer is the key to the success of this technique, and with properly chosen voltages the nanotubes show up as finely detailed fibers dispersed below the composite ' s surface. the goal, according to zhao, is to control the process well enough to allow quantitative measurements. at present the group can discriminate different concentrations of carbon nanotubes in the polymer, determine conductive networks of the nanotubes and map electric potential distribution of the nanotubes below the surface. but the measurement is quite tricky, many factors, including probe shape and even humidity affect the electrostatic force. the team used a specially designed probe tip and a patented, nist - designed afm humidity chamber. * * an interesting, not yet fully understood effect, says zhao, is that increasing the voltage between the probe and the sample at some point causes the image contrast to invert, dark regions becoming light and vice versa. the team is studying the mechanism of such contrast inversion. " we are still optimizing this efm technique for subsurface imaging, " says zhao. " if the depth of nanostructures located from the film surface can be determined quantitatively, this technique will be a powerful tool for nondestructive subsurface imaging of high dielectric nanostructures in a low dielectric matrix, with a broad range of applications in nanotechnology. " * m. h. zhao, x. h. gu, s. e. lowther, c. park, y. c. jean and t. nguyen. subsurface characterization of carbon nanotubes in polymer composites via quantitative electric force microscopy. nanotechnology 21 ( 2010 ) 225702 doi : 10. 1088 / 0957 - 4484 / 21 / 22 / 225702. * * j. w. martin, e. embree and m. r. vanlandingham. humidity chamber for stylus atomic force with cantilever. u. s. patent no. 6, 490, 913 b1, dec. 10, 2002.


by gautam naik lithium - ion batteries became crucial to the design of boeing co. ' s new dreamliner jet because they offered a combination of high power and low weight. yet the very chemistry that makes these high - tech batteries so attractive to designers may increase their risk of overheating and catching fire, a situation that has contributed to the global grounding of about 50 dreamliners in use and a halt to new deliveries after two onboard fires. investigators aren ' t just looking at the batteries. safety experts are combing over the jet ' s wiring, circuit boards and other battery - related external components as they probe the incidents. batteries convert stored chemical energy into usable, electrical energy. a lithium ion battery consists of a negative electrode and a positive electrode that are linked by an electrolyte, such as an organic solvent. when the battery is being used, the electrolyte transports ions between the electrodes ; electrons flow along a separate wire circuit and that electrical current is used to start an auxiliary power unit and for emergency power. by mixing and matching different metals and chemistries, scientists have created a range of different battery types that differ in terms of voltage, service life, size and cost. low - power devices such as those in a tv remote are usually powered by inexpensive alkaline batteries. the challenge for battery makers has been to boost the amount of energy that can be stored in a given volume — and that is where lithium - ion technology shines. a lithium - ion power - pack can deliver more energy than a similar - size battery based on another metal, a measure known as energy density. that is why lithium batteries were compelling to the 787 ' s designers. the dreamliner was crafted to allow for big fuel savings and weight reductions, some of which are enabled by the small but powerful lithium - ion batteries boeing is using. lithium is the least dense of all metals and highly electropositive, which means it delivers a high voltage. lithium - ion batteries pack twice as much energy density as nickel - metal - hydride versions, and four to six times as much energy density of the lead - acid battery found in many cars, according to stanley whittingham, a professor of chemistry and expert on lithium - ion batteries at binghamton university in binghamton, n. y. lithium also is the third - smallest element after hydrogen and helium. " because it is small, you can pull it in and out of materials easily " compared with other elements that are bigger and can ' t be moved


this is an entry for the oxford handbook of the philosophy of perception how many senses do humans possess? five external senses, as most cultures have it — sight, hearing, touch, smell, and taste? should proprioception, kinaesthesia, thirst, and pain be included, under the rubric bodily sense? what about the perception of time and the sense of number? such questions reduce to two. 1. how do we distinguish a sense from other sorts of information - receiving faculties? 2. by what principle do (... ) we distinguish the senses? aristotle discussed these questions in the de anima. h. p. grice revived them in 1967. more recently, they have taken on fresh interest as a result of a collection of essays edited by fiona macpherson. this entry reviews some approaches to these questions and advances some new ideas for the reader ’ s consideration. ( shrink ) how should we characterize the nature of perceptual experience? some theorists claim that colour experiences, to take an example of perceptual experiences, have both intentional properties and properties called ' colour qualia ', namely, mental qualitative properties which are what it is like to be conscious of colour. since proponents of colour qualia hold that these mental properties cannot be explained in terms of causal relations, this position is in opposition to a functionalist characterization of colour experience. representationalist theories of sensory experience are often thought to be vulnerable to the existence of apparently non - representational differences between experiences in different sensory modalities. seeing and hearing seem to differ in their qualia, quite apart from what they represent. the origin of this idea is perhaps grice ’ s argument, in “ some remarks on the senses, ” that the senses are distinguished by “ introspectible character. ” in this chapter i take the representationalist side by putting forward an account of sense modalities which (... ) is consistent with that view and yet pays due regard to the intuition behind grice ’ s argument. employing j. j. gibson ’ s distinction between exploratory and performatory behaviour, i point to a proprioceptive element in perceptual experience, and identify this as crucial in any account of what makes a particular way of perceiving a sense modality. ( shrink ) the failure to resolve satisfactorily epistemological issues surrounding the identification of different senses has led to questions being asked of the nature of the senses. this issue has been


way of perceiving a sense modality. ( shrink ) the failure to resolve satisfactorily epistemological issues surrounding the identification of different senses has led to questions being asked of the nature of the senses. this issue has been thrown into sharp focus by two starkly contrasting positions. the first is a realist position that draws on science and is based on the application of criteria. the second is an anti - realist position that adheres to commonsense conceptions and is partly motivated by the apparent failure of criterial approaches. in (... ) this paper i attempt to mediate between the two views. ( shrink ) the distinction we make between five different senses is a universal one. < sup > 1 < / sup > rather than speaking of generically perceiving something, we talk of perceiving in one of five determinate ways : we see, hear, touch, smell, and taste things. in distinguishing determinate ways of perceiving things what are we distinguishing between? what, in other words, is a sense modality? < sup > 2 < / sup > an answer to this question must tell us what constitutes a sense modality and so needs to do more than simply describe differences (... ) in virtue of which we can distinguish the perceptions of different senses. there are many such differences. ( shrink ) in his classic paper, " some remarks about the senses, " h. p. grice argues that our intuitive distinction among perceptual modalities requires that the modalities be characterized in terms of the introspectible character of experience. i first show that grice ' s argument provides support for the claim that perceptual experiences have qualia, namely, mental qualitative properties of experience which are what it ' s like to be conscious of perceived properties such as color. i then defend intentionalism about experience, which rejects qualia, by (... ) showing that we need not appeal to differences in qualia in order to distinguish the senses. rather, i claim that we can appeal to, among other factors, differences in the physical properties of physical objects which experience represents. ( shrink ) i argue that we should reject the sparse view that there are or could be only a small number of rather distinct senses. when one appreciates this then one can see that there is no need to choose between the standard criteria that have been proposed as ways of individuating the senses — representation, phenomenal


counting question ) ; none of the standard accounts is satisfactory. any adequate account of the senses must explain the signi? cance of the senses, that is, why distinguishing different senses matters. i provide such an explanation, and then use it as the basis for providing an account of the senses and answering the counting question. this paper discusses certain problems arising within the treatment of the senses of functions in alonzo church ' s logic of sense and denotation. church understands such senses themselves to be " sense - functions, " functions from sense to sense. however, the conditions he lays out under which a sense - function is to be regarded as a sense presenting another function as denotation allow for certain undesirable results given certain unusual or " deviant " sense - functions. certain absurdities result, e. g., an argument can be found for equating (... ) any two senses of the same type. an alternative treatment of the senses of functions is discussed, and is thought to do better justice to frege ' s original theory. ( shrink ) sensory substitution devices are a type of sensory prosthesis that ( typically ) convert visual stimuli transduced by a camera into tactile or auditory stimulation. they are designed to be used by people with impaired vision so that they can recover some of the functions normally subserved by vision. in this chapter we will consider what philosophers might learn about the nature of the senses from the neuroscience of sensory substitution. we will show how sensory substitution devices work by exploiting the (... ) cross - modal plasticity of sensory cortex : the ability of sensory cortex to pick up some types of information about the external environment irrespective of the nature of the sensory inputs it is processing. we explore the implications of cross - modal plasticity for theories of the senses that attempt to make distinctions between the senses on the basis of neurobiology. ( shrink ) there is a view abroad on which ( a ) perceptual experience has ( a ) representational content in this sense : in it something is represented to the perceiver as so. on the view, a perceptual experience has a face value at which it may be taken, or which may be rejected. this paper argues that that view is mistaken : there is nothing in perceptual experience which makes it so that in it anything is represented as so ( except insofar as the perceiver represents things (... ) to himself as so ). in


that that view is mistaken : there is nothing in perceptual experience which makes it so that in it anything is represented as so ( except insofar as the perceiver represents things (... ) to himself as so ). in that sense, the senses are silent, or, in austin ' s term, dumb. perceptual experience is not as such either veridical or delusive. it may mislead, but it does not take representation to accomplish that. ( shrink ) seeing, hearing and touching are phenomenally different, even if we are detecting the same spatial properties with each sense. this presents a prima facie problem for intentionalism, the theory that phenomenal character supervenes on representational content. the paper reviews some attempts to resolve this problem, and then looks in detail at peter carruthers ' recent proposal that the senses can be individuated by the way in which they represent spatial properties and incorporate time. this proposal is shown to be ineffective (... ) in distinguishing auditory from either visual or tactual perception, and substantial classes of visual and tactual perceptions are found that the posited spatial and temporal features fail to individuate. ( shrink ) in this paper, we see that contrary to most readings of t 1. 4. 2 in the treatise ( “ of skepticism with regard to the senses ” ), hume does not think that objects are sense impressions. this means that hume ’ s position on objects ( whatever that may be ) is not to be conflated with the vulgar perspective. moreover, the vulgar perspective undergoes a marked transition in t 1. 4. 2, evolving from what we may call vulgar perspective i into vulgar perspective ii. this paper presents the (... ) first detailed analysis of this evolution, which includes an explanation of t 1. 4. 2 ’ s four - part system. ( shrink ) the present paper suggests how, from a scientific perspective, the senses establish a link between mind and matter. ongoing research in sensory science and data analysis is related to the ongoing debate about a non - reductive theory of consciousness based on psychophysical principles. sensory science is interdisciplinary and deals with the human perception of objects by the senses of sight, smell, taste, touch, hearing etc. perception as information pro - cessing is here understood in terms of interactions between external physical (... ) stimuli and internal mental states resulting in behavioral responses. to deal with the complex and dynamic transformation between external physical


taste, touch, hearing etc. perception as information pro - cessing is here understood in terms of interactions between external physical (... ) stimuli and internal mental states resulting in behavioral responses. to deal with the complex and dynamic transformation between external physical energies and internal psychological experiences multivariate methods of data analysis are shown to be useful examples will be given from food science where cognition and emotion, activated by sense perception are vital for the survival health and well - being of humans. these approaches may contribute to bridging the explanatory gap between the subjectively experienced and the objectively observed world. future challenges towards deeper interdisciplinary discourses addressing mind - matter research in real - world situations are at stake. ( shrink ) in a treatise of human nature hume wrote a long section titled “ of skepticism with regard to the senses. ” the discussion examines two key features of our beliefs about the objects making up the external world : 1. they continue to exist, even when unperceived. 2. they are distinct from the mind and its perceptions. the upshot of the discussion is a graceful sort of intellectual despair : i cannot conceive how such trivial qualities of the fancy, conducted by such false suppositions, (... ) can ever lead to any solid and rational system... ’ tis a gross illusion to suppose, that our resembling perceptions are numerically the same ; and ’ tis this illusion, which leads us into the opinion, that these perceptions are uninterrupted, and are still existent, even when they are not present to the senses. this is the case with our popular system. and as to our philosophical one, ’ tis liable to the same difficulties ; and is over - and - above loaded with this absurdity, that it at once denies and establishes the vulgar supposition. ( treatise, 217 - 8 ) these notes examine the argument of this section of the treatise in detail. the upshot is that hume ’ s despair is founded on an error. the notes finish by drawing some lessons about the epistemology of our common - sense world view. ( shrink ) one strategy for working out how to individuate the senses is to pursue that task in tandem with that of individuating the sensory imaginings. we can tackle both, at least for the spatial senses of sight and touch, if we appeal to the idea that, while both modes represent their objects perspectivally, different forms of perspective are involved in each. this cannot, however


ofthem, including at least one presenting every entity in existence. i discuss a number ofcantorian paradoxes that seem to result from an overly large metaphysics of senses, and various possible solutions. certain more deflationary and non - traditional understandings of senses, and to what extent they fare better in solving the problems, are (... ) also discussed. in the end, it is concluded that one must divide senses into various ramified - orders in order to avoid antinomy, but that the philosophical justification of such orders is, as yet, still somewhat problematic. ( shrink ) the article deals with the lines along which manifold senses of horizonedness emerge and their reference to potentiality as a starting - point. the first section examines gurwitsch ' s analyses of field - potentialities and margin - potentialities in the light of distinctions drawn by husserl in terms of latency and patency. it is contended that husserl ' s concept of latency encompasses both modes of potentiality. the second section shows how the world - horizon functions as a background - horizon and alternation - horizon conceived of as the two fundamental (... ) modes of non - thematic consciousness. in this respect, an attempt is made to link this theme with gurwitsch ' s description of the acquisition of the character of positional index as a worldly existent. the third section is concerned with how potentiality develops into an all - encompassing domain that can be anticipated as an ideal totality and into a pregiven ground, and outlines an approach to the complementarity of this threefold characterization. this development falls out of gurwitsch ' s framework for the analysis of horizonedness. the article concludes with a characterization of the encasement - of - one - in - another of horizons. reasons are suggested for the application of some ideas of gurwitsch on thematic transformation to this sequence of levels. ( shrink ) contextualists explain certain intuitions regarding knowledge ascriptions by means of the thesis that ' knowledge ' behaves like an indexical. this explanation denies what peter unger has called invariantism, i. e., the idea that knowledge ascriptions have truth value independent of the context in which they are issued. this paper aims to provide an invariantist explanation of the contextualist ' s intuitions, the core of which is that ' knowledge ' has many different senses. with reference to two specific modalities of


the context in which they are issued. this paper aims to provide an invariantist explanation of the contextualist ' s intuitions, the core of which is that ' knowledge ' has many different senses. with reference to two specific modalities of sensation, the taste of saltiness of chloride salts, and the loudness of steady tones, it is shown that the laws of sensation ( logarithmic and power laws ) are expressions of the entropy per mole of the stimulus. that is, the laws of sensation are linear functions of molar entropy. in partial verification of this hypothesis, we are able to derive an approximate value for the gas constant, a fundamental physical constant, directly from psychophysical measurements. (... ) the significance of our observation lies in the linking of the phenomenon of “ sensation ” directly to a physical measure. it suggests that if the laws of physics are universal, the laws of sensation and perception are similarly universal. it also connects the sensation of a simple, steady physical signal with the molecular structure of the signal : the greater the number of microstates or complexions of the stimulus signal, the greater the magnitude of the sensation ( saltiness or loudness ). the hypothesis is currently tested on two sensory modalities. ( shrink ) my aim in this note is to disambiguate various senses of ‘ conventional ’ that in the philosophy of physics have been frequently conflated. as a case study, i will refer to the well - known issue of the conventionality of simultaneity in the special theory of relativity, since it is particularly in this context that the above mentioned confusion is present. carruthers invokes a number of controversial assumptions to support his thesis. most are questionable and unnecessary to investigate the wider relevance of language in cognition. a number of research programs ( e. g., interactionist psycholinguistics and cognitive linguistics ) have for years pursued a similar thesis and provide a more empirically grounded framework for investigating language ’ cognitive functions. in philosophy, it is almost a platitude to argue that fact and value intertwine. however, in empirically oriented educational research, it is not. hence, there is some affinity between logical positivism, which is no longer tenable in philosophy, and empirically based contemporary educational research in terms of assumptions each makes about “ the given. ” in this essay, koichiro misawa casts light on how fact and value intertwine by invoking the notion of “ second nature ” that john


and empirically based contemporary educational research in terms of assumptions each makes about “ the given. ” in this essay, koichiro misawa casts light on how fact and value intertwine by invoking the notion of “ second nature ” that john mcdowell has reanimated. this will in (... ) turn prompt us to see the relation between nature and nurture, as well as between mind and world, quite differently and to discern two senses of “ the given ” : one is illusory ; the other educational. misawa concludes that the philosophy of education should and can take the lead in forming rigorous interdisciplinary studies of the human future with a certain sensitivity to the tight and complex interweaving between the empirical and the conceptual, or between the factual and the normative. ( shrink ) hilary putnam has famously undergone some radical changes of mind with regard to the issue of scientific realism and its wider epistemological bearings. in this paper i defend the arguments put forward by early putnam in his essays on the causal theory of reference as applied to natural - kind terms, despite his own later view that those arguments amounted to a form of ' metaphysical ' realism which could not be sustained against various lines of sceptical attack. i discuss some of the reasons (... ) for putnam ' s retreat, first to the theory of ' internal ( or framework - relative ) realism proposed in his middle - period writings, and then to a commonsensepragmatist stance which claims to resituate this whole discussion on ground that has not been trorldden into ruts by the contending philosophical schools. in particular i examine his protracted engagement with various forms of anti - realist doctrine ( michael dummett ' s most prominent among them ), with wittgenstein ' s thinking about language - games or meaning - as - use, and with a range of sceptical - relativist positions adopted in the wake of quine ' s influential attack on the two last ' dogmas ' of logical empiricism. my paper seeks to show that putnam has been over - impressed by some of the arguments — from these and other sources — which he takes to constitute a knock - down case against the kind of extemalist and causal - realist approach developed in his early essays. it concludes by re - stating that position in summary form and relating it to other, more recent defences of causal realism in epistemology and philosophy of science. ( shrink ) the doctrine of the


water - quality analyses and each analysis includes many different physical and chemical properties, such as water temperature and selenium concentration. geochemical and statistical techniques can be used to extract information from this large multivariate data set. for example, concentration of chemicals such as major ions might be used to predict whether or not a water sample from an irrigated area contains an elevated concentration of selenium. the geochemical computer program snorm ( bodine and jones, 1986 ) was the " geochemical tool " used to calculate concentrations of simple salts from the results of the chemical analyses of surface - water samples from niwqp study sites. the 12 different simple - salt concentrations calculated with the snorm program for each water sample are representative of the minerals ( " salts " ) that would remain after a water sample was completely evaporated. to evaporate the thousands of water samples collected at all the niwqp study areas and determine the amount and type of salt remaining would be quite labor intensive ; instead, the snorm computer program simulates this evaporation almost instantly. the abundance and type of simple salts calculated with the snorm program provides useful geochemical information on what kind of minerals ( selenium or non - selenium bearing ) the water might have contacted and partially dissolved. this is analogous to determining where a person lives on the basis of his or her accent. | after the concentrations of simple salts were calculated for the thousands of niwqp water samples, the next step was to determine if groupings of simple salts could characterize water samples with high or low selenium concentrations. a " statistical tool " called pattern - recognition modeling ( meglen and sistko, 1985 ) was used to evaluate the large simple - salt data base generated with the snorm computer program. pattern - recognition modeling techniques enhance the interpretation of large multivariate data bases such as the one used in the niwqp data synthesis study. pattern - recognition modeling uses statistical and graphical techniques to " chemically fingerprint " the groups of simple salts representing different types of minerals ( selenium or non - selenium bearing ) that might have contacted and partially dissolved in water sampled during the niwqp. the selenium concentration for all the niwqp samples was already known ; thus, calculating the association between the simple - salt group and the selenium concentrations in water samples was explicit. this simple - salt group / selenium association could then be applied to


tensorwedge [ tensor1, tensor2,... ] represents the antisymmetrized tensor product of the. - tensorwedge [ a, b ] can be input as. the character is entered as esct ^ esc or \ [ tensorwedge ]. - in a tensor wedge product of explicit or symbolic arrays, all slots must have the same dimension, though different arrays may have different ranks. tensorwedge generalizes cross, which requires vectors of length. - the tensorwedge product of several arrays is an antisymmetric array, always given in symmetrizedarray form. - if the tensors are not antisymmetric, then they are effectively antisymmetrized before performing the product. vectors are considered antisymmetric tensors of rank 1. scalars are considered antisymmetric tensors of rank 0. - the wedge product tensorwedge [ t1,..., tk ] of the antisymmetric tensors is equivalent to multinomial [ r1,..., rk ] * symmetrize [ tensorproduct [ t1,..., tk ], antisymmetric [ all ] ], where is the tensor rank of. new in 9


editor ' s note : considering the expense and difficulty behind silicon alternatives with superior performance, i hope this approach pans out. this tech promises to create some very fast chips. menlo park, calif. — move over, silicon — it may be time to give the valley a new name. physicists at the department of energy ' s ( doe ) slac national accelerator laboratory and stanford university have confirmed the existence of a type of material that could one day provide dramatically faster, more efficient computer chips. recently - predicted and much - sought, the material allows electrons on its surface to travel with no loss of energy at room temperatures and can be fabricated using existing semiconductor technologies. such material could provide a leap in microchip speeds, and even become the bedrock of an entirely new kind of computing industry based on spintronics, the next evolution of electronics. physicists yulin chen, zhi - xun shen and their colleagues tested the behavior of electrons in the compound bismuth telluride. the results, published online june 11 in science express, show a clear signature of what is called a topological insulator, a material that enables the free flow of electrons across its surface with no loss of energy. the discovery was the result of teamwork between theoretical and experimental physicists at the stanford institute for materials & energy science, a joint slac - stanford institute. in recent months, simes theorist shoucheng zhang and colleagues predicted that several bismuth and antimony compounds would act as topological insulators at room - temperature. the new paper confirms that prediction in bismuth telluride. " the working style of simes is perfect, " chen said. " theorists, experimentalists, and sample growers can collaborate in a broad sense. " the experimenters examined bismuth telluride samples using x - rays from the stanford synchrotron radiation lightsource at slac and the advanced light source at lawrence berkeley national laboratory. when chen and his colleagues investigated the electrons ' behavior, they saw the clear signature of a topological insulator. not only that, the group discovered that the reality of bismuth telluride was even better than theory. " the theorists were very close, " chen said, " but there was a quantitative difference. " the experiments showed that bismuth telluride could tolerate even higher temperatures than theorists had predicted. " this means that the material is closer to application than we thought, " chen said. this magic is possible thanks to surprisingly well - behaved electrons