THERMODYNAMICS (from Gr.
.^ Epµ5s, hot, 81lva.us, force).
^ This tells us that we can use work to force heat to flow from cold to hot and we can convert heat to useful work.- PES 100: Thermodynamics 10 January 2010 17:12 UTC www.uccs.edu [Source type: Original source]
.^ The converse process of the transformation of heat into mechanical work or other forms of energy is subject to limitations.
^ Heat cannot be completely transformed into work.- ECONOMY AND THERMODYNAMICS 10 January 2010 17:12 UTC www.ecen.com [Source type: FILTERED WITH BAYES]
^ I. The name thermodynamics is given to that branch of the general science of Energetics which deals with the relations between thermal and mechanical energy, and the transformations of heat into work, and vice versa.
.^ Other transformations of heat are often included under the same title (see Energetics ).
^ Specific heat under other conditions.
^ Study of the laws governing the transformation of heat energy to and from other forms of energy, thus of the efficient design and working of heat engines (such as the gas engine and the steam engine).
.^ An historical account of the development of thermodynamics is given in the article Heat.
^ Students in this course develop a mathematical and physical understanding of the fundamental concepts and principles of classical thermodynamics including properties, state determination, work and heat transfer.- Texas Tech University :: Mechanical Engineering :: ME 2322 Engineering Thermodynamics I 11 January 2010 21:25 UTC www.me.ttu.edu [Source type: Academic]
^ The relation between heat and energy was important for the development of steam engines, and in 1824 Sadi Carnot had captured some of the ideas of thermodynamics in his discussion of the efficiency of an idealized engine.- Historical Notes: History of thermodynamics 10 January 2010 17:12 UTC www.wolframscience.com [Source type: FILTERED WITH BAYES]
.^ Reversible and irreversible processes, the second law of thermodynamics.- Subject Sylbus: thermodynamics - 084213 10 January 2010 17:12 UTC techmvs.technion.ac.il [Source type: Academic]
^ Second Law of Thermodynamics - second statement .- Laws of Thermodynamics 11 January 2010 21:25 UTC physics.csustan.edu [Source type: FILTERED WITH BAYES]
^ E is a reversible heat engine and R an infinite heat reservoir.- Second law of thermodynamics - encyclopedia article - Citizendium 11 January 2010 21:25 UTC en.citizendium.org [Source type: Academic]
.^ The application will necessarily be confined to simple cases such as are commonly met with in practice, or are required for reference in cognate subjects.
^ A perfectly adequate response to such nonsense is to point out that the earth is not an isolated system, and therefore the condition required by the Second Law is not met.- Creationism and the Laws of Thermodynamics | NCSE 10 January 2010 17:12 UTC ncse.com [Source type: Academic]
^ Modeling of exsolution and related phenomena such as critical points requires a better model for the free energy of phases than the simple one implemented by the demonstration applet.- Phase Equilibria Glossary 11 January 2010 21:25 UTC www.gps.caltech.edu [Source type: Reference]
.^ The first law is the application of conservation of energy to the system, and the second sets limits on the possible efficiency of the machine and determines the direction of energy flow.
^ Preface Introduction Thermodynamic Systems Zeroth Law First Law Second Law Third Law Applications Appendix Further Reading [ edit ] Related books .- Engineering Thermodynamics - Wikibooks, collection of open-content textbooks 10 January 2010 17:12 UTC en.wikibooks.org [Source type: Reference]
^ However, no information about the direction of the process can be obtained by the application of the first law.- Second Law of Thermodynamics - Engineers Edge 11 January 2010 21:25 UTC www.engineersedge.com [Source type: Reference]
-
.^ The converse process of the transformation of heat into mechanical work or other forms of energy is subject to limitations.
^ Mechanical Equivalent of Heat 70.- THERMODYNAMICS 10 January 2010 17:12 UTC www.wesleyan.edu [Source type: Academic]
^ Some of the available energy is always dissipated in nonrecoverable friction or heat energy.- Second Law Of Thermodynamics (SLOT) and its Application to Evolution 11 January 2010 21:25 UTC www.tektonics.org [Source type: FILTERED WITH BAYES]
.^ The converse process of the transformation of heat into mechanical work or other forms of energy is subject to limitations.
^ Heat cannot be completely transformed into work.- ECONOMY AND THERMODYNAMICS 10 January 2010 17:12 UTC www.ecen.com [Source type: FILTERED WITH BAYES]
^ During the conversion process, all the energy that enters a conversion device is turned into other forms of energy.- Energy Rules! Energy Conversion and the Laws of Thermodynamics - Energy Conversion Introduction 10 January 2010 17:12 UTC www.uwsp.edu [Source type: FILTERED WITH BAYES]
.^ The total kinetic energy is an extensive quantity.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ From energy conservation this work would generate heat and lead to an increase of entropy .- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
^ The total energy a body contains as a result of the positions and motions of its molecules is called its internal energy; in general, a body's temperature is a direct measure of its internal energy.- thermodynamics Facts, information, pictures | Encyclopedia.com articles about thermodynamics 10 January 2010 17:12 UTC www.encyclopedia.com [Source type: Academic]
.^ The First Law of Thermodynamics (conservation of energy) .
^ Energy agrees with the first law of thermodynamics?- WikiAnswers - What is the process that satisfies the first law of thermodynamics but violates the second law 11 January 2010 21:25 UTC wiki.answers.com [Source type: General]
^ The First Law is also stated as energy is conserved .- Laws of Thermodynamics - Cryogenic Information Library - Technifab Products, Inc. 10 January 2010 17:12 UTC www.technifab.com [Source type: FILTERED WITH BAYES]
.^ Heat energy is transformed into work energy.- The second law of thermodynamics - Total equilibrium and heat engines. 11 January 2010 21:25 UTC www.flyingturtle.org [Source type: Original source]
^ Energy: The ability to do work or supply heat.- College Chemistry: Thermodynamics 10 January 2010 17:12 UTC www.chemistry24.com [Source type: FILTERED WITH BAYES]
- Teach Chemistry: Thermodynamics 10 January 2010 17:12 UTC www.chemistry24.com [Source type: FILTERED WITH BAYES]
^ And this is true for EVERYTHING in general, the universe all over."- SECOND LAW OF THERMODYNAMICS - Does this basic law of nature prevent Evolution? - ChristianAnswers.Net 10 January 2010 17:12 UTC www.christiananswers.net [Source type: FILTERED WITH BAYES]
.^ Heat cannot be completely transformed into work.- ECONOMY AND THERMODYNAMICS 10 January 2010 17:12 UTC www.ecen.com [Source type: FILTERED WITH BAYES]
^ Heat, work and internal energy: the concept of a function of state.- Stephen Blundell's homepage 10 January 2010 17:12 UTC users.ox.ac.uk [Source type: Academic]
^ That is, no device transfers its heat energy completely into work.- Physics 20: Thermodynamics 10 January 2010 17:12 UTC www.sasked.gov.sk.ca [Source type: FILTERED WITH BAYES]
.^ It is the second law that prohibits such engines.- Demons, Engines and the Second Law 11 January 2010 21:25 UTC www.aeiveos.com [Source type: Original source]
^ Second law of thermodynamics and the Carnot cycle .- AME Undergraduate Courses 10 January 2010 17:12 UTC www.nd.edu [Source type: Reference]
^ Needless to say, such a cycle contradicts the second law of thermodynamics.- BIASED THERMAL MOTION AND THE SECOND LAW OF THERMODYNAMICS 11 January 2010 21:25 UTC wbabin.net [Source type: FILTERED WITH BAYES]
.^ Thermodynamics The effects of work, heat and energy on a system Related Documents .
^ Heat energy is transformed into work energy.- The second law of thermodynamics - Total equilibrium and heat engines. 11 January 2010 21:25 UTC www.flyingturtle.org [Source type: Original source]
^ Energy: The ability to do work or supply heat.- College Chemistry: Thermodynamics 10 January 2010 17:12 UTC www.chemistry24.com [Source type: FILTERED WITH BAYES]
- SAT Chemistry: Thermodynamics 10 January 2010 17:12 UTC www.rapidlearningcenter.com [Source type: Academic]
- Teach Chemistry: Thermodynamics 10 January 2010 17:12 UTC www.chemistry24.com [Source type: FILTERED WITH BAYES]
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.^ Density - Density ( ) is defined as mass per unit volume.
^ P and V are the pressure and volume of the system, respectively.- Thermodynamics - Chemistry Encyclopedia - reaction, gas, number, equation 11 January 2010 21:25 UTC www.chemistryexplained.com [Source type: Academic]
^ The state of a substance may be defined by means of the temperature and entropy as co-ordinates, instead of employing the pressure and volume as in the indicator diagram.
I).
.^ Path - The series of states a system passes through during a process.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ Shape of polytropic-process lines on the h - s diagram.- The Design of Gas Turbine Engines-Thermodynamics and Aerodynamics-2nd Ed: CD ROM & DVD - CD-ROM 11 January 2010 21:25 UTC catalog.asme.org [Source type: Academic]
^ A device such as a refrigerator or air conditioner, designed to remove heat from a cold region and transfer it to a hot region, is essentially a heat engine operating in reverse, as the following energy flow diagram shows: A refrigerator, consisting of a fluid pumped through a closed system, involves a four-step process.- Heat engines and the second law 11 January 2010 21:25 UTC physics.bu.edu [Source type: FILTERED WITH BAYES]
.^ It is tacitly assumed that the motion is relatively so slow that the pressure and temperature of the substance are practically uniform throughout its mass at any stage of the process.
^ Substances describable by temperature and pressure alone .- Thermodynamics - Biocrawler, the free encyclopedia 10 January 2010 17:12 UTC www.biocrawler.com [Source type: Academic]
^ The following graphs show the changes in pressure, velocity and temperature of the gas as it passes through the various stages of a jet engine.- Thermodynamics 10 January 2010 17:12 UTC www.eng.fsu.edu [Source type: Academic]
.^ Otherwise the transformation could not be fully represented on the diagram, and would not be reversible.
^ Molecules could briefly extract energy from their surroundings, combining in ways that would otherwise be impossible in practice.- Law of Thermodynamics Faces Repeal - WSJ.com 11 January 2010 21:25 UTC online.wsj.com [Source type: General]
^ That is, the system would stay at the temperatures of the reservoirs during those heat transfers - necessary for the process to be reversible since the heat flow could not be reversed to go from the lower to the higher temperature.- SECOND LAW 11 January 2010 21:25 UTC www.calpoly.edu [Source type: Original source]
.^ It is given by the area under the PV graph .- First Law of Thermodynamics 10 January 2010 17:12 UTC tutors4you.com [Source type: Reference]
^ In each case, the work done is the area under the curve.- Physics: The Laws of Thermodynamics - CliffsNotes 11 January 2010 21:25 UTC www.cliffsnotes.com [Source type: FILTERED WITH BAYES]
^ The area BCDdb under the path represents the external work done by the substance in expanding from B to D, which is analytically represented by the integral of pdv taken along the given path.
.^ One such variable of state is temperature.- Second Law of Thermodynamics - SkepticWiki 11 January 2010 21:25 UTC www.skepticwiki.org [Source type: Original source]
^ Thus, temperature has this property that energy does not have.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ Any closed path or figure, such as ABCD, represents a complete cycle or series of operations, in the course of which the substance is restored to its original state with respect to temperature, intrinsic energy and other properties.
.^ In each case, the work done is the area under the curve.- Physics: The Laws of Thermodynamics - CliffsNotes 11 January 2010 21:25 UTC www.cliffsnotes.com [Source type: FILTERED WITH BAYES]
^ Recall that the work is the negative of the area under the curve.- Introduction to the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.chem.arizona.edu [Source type: Original source]
^ For this segment, work is done by the piston on the gas , which is represented by the area under the C–D segment of the curve from V 3 to V 4 .- Physics: The Laws of Thermodynamics - CliffsNotes 11 January 2010 21:25 UTC www.cliffsnotes.com [Source type: FILTERED WITH BAYES]
.^ The work is the area of the enclosed region on the graph.- Heat engines and the second law 11 January 2010 21:25 UTC physics.bu.edu [Source type: FILTERED WITH BAYES]
^ One of the cycles is the reversible path, and is so labelled.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ The area of the cycle, viz., that enclosed by the path Bcda , represents the balance of external work done by the substance in one cycle, and is positive if the cycle is described clockwise 0' O as indicated by the arrows.
.^ We can rewrite this expression for a process at constant volume as .
^ Specific Heat at constant Volume .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ Practice Problem 1: Which of the following processes are run at constant volume and which are run at constant pressure?- Energy, Enthalpy, and the First Law ofThermodynamics 10 January 2010 17:12 UTC chemed.chem.purdue.edu [Source type: Academic]
.^ For the isothermal expansion I drew temperature on the y-axis and volume on the x-axis, and drew a line of constant temperature in the increasing x-direction.- Thermodynamics Questions 10 January 2010 17:12 UTC www.physicsforums.com [Source type: FILTERED WITH BAYES]
^ The potential used depends on the constraints of the system, such as constant temperature or pressure.- Thermodynamics - encyclopedia article - Citizendium 10 January 2010 17:12 UTC reid.citizendium.org [Source type: Academic]
- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
- Thermodynamics 10 January 2010 17:12 UTC pustakalaya.olenepal.org [Source type: Reference]
^ Constant pressure expansion/compression work.- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
.^ The isothermals are approximately equilateral hyperbolas ( pv= constant), with the axes of p and v for asymptotes, for a gas or unsaturated vapour, but coincide with the isopiestics for a saturated vapour in presence of its liquid.
^ During this constant-volume reheating, we have PV = nkT , so the amount of pressure regained is a direct indication of how much the gas cooled down when it lost an amount of energy Δ E .
^ Path 1a: isothermal expansion of gas from A = 3 bar, 1 L to B = 1 bar, 3 L against constant P ext of 1 bar.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ The adiabatic curve has a more negative slope than the isothermal curve.
^ (This is analogous to insulated compression or expansion of a heat engine; in general, a compression or expansion of this type, with no transfer of heat, is called adiabatic .
^ Expansion or compression under the condition of heat-insulation, represented by curves called Adiabatics, such as BAZ or CDZ', which are necessarily steeper than the isothermals.
.^ E is a reversible heat engine and R an infinite heat reservoir.- Second law of thermodynamics - encyclopedia article - Citizendium 11 January 2010 21:25 UTC en.citizendium.org [Source type: Academic]
^ Efficiency of a heat engine .- The Second Law of Thermodynamics 11 January 2010 21:25 UTC www.chem1.com [Source type: FILTERED WITH BAYES]
^ Since the two isotherms are joined by two adiabats, it can be shown that .- Chemical thermodynamics 11 January 2010 21:25 UTC guweb2.gonzaga.edu [Source type: Academic]
.^ Heat will flow only from material at higher temperature to material at a lower temperature.- Contractor School Online® - Contractor Glossary of Terms 11 January 2010 21:25 UTC www.contractorreferral.com [Source type: Reference]
^ But if there is a temperature difference, some of the heat will be used to raise the temperature of the heat sink .- The Second Law of Thermodynamics 10 January 2010 17:12 UTC www.bluffton.edu [Source type: FILTERED WITH BAYES]
^ Heat can be turned into mechanical work, but there are limitations.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
.^ Two of the processes are isothermal and two are adiabatic.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ Taking this ideal limit as a theoretical or absolute zero, the value of H may be represented on the diagram by the whole area included between the two adiabatics BAZ, CDZ' down to the points where they intersect the isothermal of absolute zero, or the zero isopiestic OV asymptotically at infinity.
^ If the substance in any state such as B were allowed to expand adiabatically ( dH = o ) down to the absolute zero, at which point it contains no heat and exerts no pressure, the whole of its available heat energy might theoretically be recovered in the form of external work, represented on the diagram by the whole area BAZcb under the adiabatic through the state-point B, bounded by the isometric Bb and the zero isopiestic bV. The change of the intrinsic energy in passing from one state to another, as from B to C is represented by the addition of the heat-area H= Bczz ', and the subtraction of the work-area W = BCcb.
.^ If energy always exists, one can always use it.- HEAT and THE THREE LAWS OF THERMODYNAMICS 11 January 2010 21:25 UTC www.josephnewman.com [Source type: Original source]
^ The converse process of the transformation of heat into mechanical work or other forms of energy is subject to limitations.
^ It is given by the area under the PV graph .- First Law of Thermodynamics 10 January 2010 17:12 UTC tutors4you.com [Source type: Reference]
.^ Michael, the puzzle can be expressed without reference to coarse states.- Overcoming Bias : Scandalous Heat 10 January 2010 17:12 UTC www.overcomingbias.com [Source type: Original source]
^ It is a mathematical requirement that state variables have Exact differentials .- Phase Equilibria Glossary 11 January 2010 21:25 UTC www.gps.caltech.edu [Source type: Reference]
^ Q is the incremental energy state change / increase .- Second Law Of Thermodynamics (SLOT) and its Application to Evolution 11 January 2010 21:25 UTC www.tektonics.org [Source type: FILTERED WITH BAYES]
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.^ Application of Carnot's Principle.
-
.^ Efficiency of a heat engine .- The Second Law of Thermodynamics 11 January 2010 21:25 UTC www.chem1.com [Source type: FILTERED WITH BAYES]
^ F(T 2 ,T 1 ) F is some as yet unknown function (an algebraic expression) of the two temperatures.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ This makes the engine less efficient that a Carnot engine, because heat is being discharged at a temperature that is not as cool as the environment.
.^ He was unable to XXV.I. 26 a apply the principle directly in this form, as it would require an exact knowledge of the properties of substances through a wide range of temperature.
^ We will return to phase transformations later, but let's now see why these phases form in the first place and why each one is stable over such a wide range of temperatures.- Thermodynamics 10 January 2010 17:12 UTC www.tulane.edu [Source type: Reference]
^ "In its most modern forms, the Second Law is considered to have an extremely wide range of validity.- SCIENTISTS SPEAK ABOUT LAWS OF NATURE VS EVOLUTION - 1 11 January 2010 21:25 UTC www.pathlights.com [Source type: Original source]
.^ Net work per unit mass flow in a Brayton cycle 6 .- II THE SECOND LAW OF THERMODYNAMICS 11 January 2010 21:25 UTC web.mit.edu [Source type: Reference]
^ What does work in a cycle correspond to on a P-V diagram?- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
^ It is natural to confuse heat with temperature.
.^ It simply asserts that the efficiency function F'(t), which is known as Carnot's function, is the same for all substances at the same temperature.
^ That is, they will all have the same temperature.
^ The fourth law of thermodynamics says that if two objects are both at the same temperature as a third, then all three are at the same temperature - they are said to be at a thermal equilibrium.
.^ Thermodynamic Temperature Scale - A temperature scale that is independent of the properties of the substances that are used to measure temperature.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ Temperatures measured on this scale are designated as degrees Fahrenheit (° F) .- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
^ It simply asserts that the efficiency function F'(t), which is known as Carnot's function, is the same for all substances at the same temperature.
Applying the above equation to a gas obeying
the law
pv=RT, for which the work done in isothermal
expansion from a volume i to a volume
r is
W=RT
loger, whence
dW=R log e
rdt, he deduced the expression for the heat absorbed by a gas in
isothermal expansion
H=R log
er/F'(t). He also
showed that the difference of the specific heats at constant
pressure and volume,
S - s, must be the same for equal
volumes of all gases at the same temperature and pressure, being
represented by the expression
R/TF'(t). He remarks that ”
the law according to which the motive power of heat varies at
different points of the thermometric scale is intimately connected
with that of the variations of the specific heats of gases at
different temperatures - a law which experiment has not yet made
known to us with sufficient exactness." If he had ventured to
assume the difference of the specific heats constant, it would have
followed that F'(t) must vary inversely as
T. The same
result follows if the work
W =RT log e ?' done by a
gas in isothermal expansion is assumed to be equivalent or
proportional to the heat absorbed,
H=R log e r/F'(t).
.^ In the calculation the following assumptions are made: 1.- Heaven is Hotter than Hell 10 January 2010 17:12 UTC www.lhup.edu [Source type: FILTERED WITH BAYES]
^ Mechanical Equivalent of Heat 70.- THERMODYNAMICS 10 January 2010 17:12 UTC www.wesleyan.edu [Source type: Reference]
^ Mechanical equivalent of heat .- Thermodynamics is the Connection Between Heat and Work - Succeed in Understanding Physics: School for Champions 10 January 2010 17:12 UTC www.school-for-champions.com [Source type: FILTERED WITH BAYES]
.^ See a textbook for more details on G and G°´ - we will see this later on at transition state theory References 1.- Introductory biological thermodynamics 10 January 2010 17:12 UTC www.slideshare.net [Source type: Academic]
^ Langton's conclusion is that the 'Carnot Principle' based on the Caloric theory, allowed for the possibility of perpetual motion machines of the second kind.
^ Clausius, who first stated the principle of Carnot in a manner consistent with the true theory of heat, expresses this law as follows: - It is impossible for a self-acting machine, unaided by any external agency, to convey heat from one body to another at a higher temperature.- The Second Law of Thermodynamics 11 January 2010 21:25 UTC www.tim-thompson.com [Source type: Original source]
.^ Holtzmann (1845) by the same assumption deduced the value J/T for the function F'(t), but obtained erroneous results by combining this assumption with the caloric theory.
^ Carnot's result was remarkably arrived at using the erroneous concept that heat is an indestructible substance, that is, the caloric theory of heat .- Sample Chapter for Haddad, W.M., Chellaboina, V., Nersesov, S.G.: Thermodynamics: A Dynamical Systems Approach. 10 January 2010 17:12 UTC www.pupress.princeton.edu [Source type: Reference]
^ When necessary, results have been adjusted to units of mol dm -3 to obtain the numerical value(s) of K c given in these tables.- Thermodynamics of Enzyme-Catalyzed Reactions 10 January 2010 17:12 UTC xpdb.nist.gov [Source type: Academic]
.^ Laws are expected to apply generally.- Jeff's Lunchbreak: Creation Museum/Creationist Rule of Thumb with the 2nd Law of Thermodynamics 11 January 2010 21:25 UTC www.jefflewis.net [Source type: Original source]
^ If the experiment unequivocally shows that their values differ, the second law is disproved.- BIASED THERMAL MOTION AND THE SECOND LAW OF THERMODYNAMICS 11 January 2010 21:25 UTC wbabin.net [Source type: FILTERED WITH BAYES]
^ What law is the same like the first law of thermodynamics?- WikiAnswers - What is the process that satisfies the first law of thermodynamics but violates the second law 11 January 2010 21:25 UTC wiki.answers.com [Source type: General]
.^ The values of F'(t) calculated previously by Sir W. Thomson (Lord Kelvin) from Regnault's tables of the properties of steam, assuming the gaseous laws, did not vary exactly as J/T. Joule's experiments on the equivalence of W and H were not sufficiently precise to decide the question.
^ First Law; steam tables .
^ Henri-Victor Regnault shows that gas behavior doesn't quite follow Boyle's law at low temperatures and extrapolates a value of -273°C for absolute zero. Joule and Kelvin shows that expanding gases become cooler in the process. .- Sketching the History of Statistical Mechanics and Thermodynamics 11 January 2010 21:25 UTC omega.math.albany.edu:8008 [Source type: Academic]
.^ Thermodynamic Temperature Scale - A temperature scale that is independent of the properties of the substances that are used to measure temperature.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ This most fundamental point was finally settled by a more delicate test, devised by Lord Kelvin, and carried out in conjunction with Joule (1854), which showed that the fundamental assumption W =H in isothermal expansion was very nearly true for permanent gases, and that F'(t) must therefore vary very nearly as J/T. Kelvin had previously proposed to define an absolute scale of temperature independent of the properties of any particular substance in terms of Carnot's function by making F'(t) constant.
^ Therefore, the accumulation term must be zero.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
.^ Kelvin Scale - An absolute thermodynamic temperature scale first proposed by Lord Kelvin.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ Carnot's theorem lays the basis for the absolute temperature scale.- JHT :: The Second Law of Thermodynamics and the Evolution of Living Systems 11 January 2010 21:25 UTC www.humanthermodynamics.com [Source type: Academic]
^ What will happen to the gas at absolute zero temperature (0 K)?- Ask the Experts: Thermodynamics 10 January 2010 17:12 UTC www.physlink.com [Source type: FILTERED WITH BAYES]
.^ The converse process of the transformation of heat into mechanical work or other forms of energy is subject to limitations.
^ In this cycle, a fluid (called a refrigerant) in super-heated vapor form flows through a pipe and into a compressor where it is compressed into a hotter gas with a higher pressure.- Apologetics Press - God and the Laws of Thermodynamics: A Mechanical Engineer�s Perspective 10 January 2010 17:12 UTC www.apologeticspress.org [Source type: Original source]
^ It is a set of theories that correlate macroscopic properties that we can measure (such as temperature, volume, and pressure) to energy and its capability to deliver work.- ENGINEERING.com > Thermodynamics 11 January 2010 21:25 UTC www.engineering.com [Source type: Reference]
(2) 5.
Thermodynamical Relations. -
.^ Thermodynamic Temperature Scale - A temperature scale that is independent of the properties of the substances that are used to measure temperature.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ The most important and most useful of the relations between the thermodynamical properties of a substance may be very simply deduced from a consideration of the indicator diagram by a geometrical method, which is in many respects more instructive than the analytical method generally employed.
^ I. The name thermodynamics is given to that branch of the general science of Energetics which deals with the relations between thermal and mechanical energy, and the transformations of heat into work, and vice versa.
Referring to fig.
.^ This added heat changed the temperature of the band.
^ Q a /T a = Q r /T r where Q a is the heat added at the temperature T a , and Q r is the heat removed at the temperature T r , the difference between Q a and Q r is the work delivered by the ideal cycle.- "Tracing the Second Law", Feature Article, July 2007 11 January 2010 21:25 UTC www.memagazine.org [Source type: FILTERED WITH BAYES]
^ Heat engines - Isothermal and adiabatic processes .- thermodynamics -- Britannica Online Encyclopedia 10 January 2010 17:12 UTC www.britannica.com [Source type: Reference]
If the difference N
Isopies `som
et7„,l8 FIG. I.
of temperature
.^ The latter involve a few degrees of freedom.- http://staff.science.uva.nl/~nieuwenh/QL2L.html 11 January 2010 21:25 UTC staff.science.uva.nl [Source type: Academic]
^ A heat pump may have an efficiency of 300% - for a small temperature gradient.- The Oil Drum | Why We "Waste" Energy: The Second Law of Thermodynamics Explains--UPDATED 8/7 11 January 2010 21:25 UTC www.theoildrum.com [Source type: FILTERED WITH BAYES]
^ Since there was no heat flow from the ball itself, there was no decrease in entropy from that subsystem (ie, the ball) and the overall entropy is equal to heat of impact divided by the absolute temperature of the surroundings (assuming, of course, that the small amount of heat generated did not change the temperature of the surroundings) There is no increase in entropy until the ball strikes the ground.- A Brief Review of Thermodynamics 11 January 2010 21:25 UTC www.fsteiger.com [Source type: Original source]
.^ It is a set of theories that correlate macroscopic properties that we can measure (such as temperature, volume, and pressure) to energy and its capability to deliver work.- ENGINEERING.com > Thermodynamics 11 January 2010 21:25 UTC www.engineering.com [Source type: Reference]
^ The problem with rising temperatures with elevation, and erroneous constant humidity, is a double deviation from the actual observations!- Niche Modeling » Greenhouse Thermodynamics and GCMs 10 January 2010 17:12 UTC landshape.org [Source type: FILTERED WITH BAYES]
^ At 373.14 K (99.99°C), the boiling point of water is reached at atmospheric pressure, and further additions of heat begin to boil off some of the water at this constant temperature.- Entropy - A Basic Understanding : International site for Spirax Sarco 11 January 2010 21:25 UTC www.spiraxsarco.com [Source type: FILTERED WITH BAYES]
.^ EC is the expansion ( v" - v' ) produced by the same rise of temperature if the pressure is kept constant.
^ This constant is independent of the starting concentrations and will always be the same at constant temperature and pressure.
^ It would do away with the well-developed mathematical relationships of physical chemistry, including the effect of temperature and pressure on equilibrium constants and phase changes.- Second Law of Thermodynamics 10 January 2010 17:12 UTC www.fsteiger.com [Source type: FILTERED WITH BAYES]
- Does evolution violate the second law of thermodynamics? 10 January 2010 17:12 UTC www.takeonit.com [Source type: Original source]
- The Second Law of Thermodynamics, Evolution, and Probability 11 January 2010 21:25 UTC www.talkorigins.org [Source type: Reference]
- - Thermodynamics vs. Evolutionism - 11 January 2010 21:25 UTC www.trueorigin.org [Source type: Original source]
- A Brief Review of Thermodynamics 11 January 2010 21:25 UTC www.fsteiger.com [Source type: Original source]
.^ "We hope that these seemingly mysterious relations become clearer by reading through this book."- The Second Law of Thermodynamics. by Brig Klyce 10 January 2010 17:12 UTC www.panspermia.org [Source type: FILTERED WITH BAYES]
^ Substituting these symbols in the expression for the area, the relation becomes H=o(p' - p„)(v„_v')/(o' - o").
.
.^ This relation may be interpreted in two ways, according as we require the heat absorbed in terms of the change of pressure or volume.
^ Similarly with pressure and volume; these cannot be precisely defined for a changing system because not every particle in the system is 'aware' of their current value, and certain areas of the system may behave as though the system has different pressure and volume.- Basic thermodynamics - Wikiversity 10 January 2010 17:12 UTC en.wikiversity.org [Source type: Academic]
^ The most direct example is the work term PdV , where pressure P (force per area) plays the role of generalized force and infinitesimal change of volume dV plays the role of displacement ( dV can, indeed, be effected by the infinitesimal displacement of a wall of a container).- Thermodynamics - encyclopedia article - Citizendium 10 January 2010 17:12 UTC reid.citizendium.org [Source type: Academic]
.^ The change in entropy is equal to the change in the heat along a reversible path divided by the temperature.- The Second Law of Thermodynamics states that the universe tends toward high entropy. If so, what happens when there is nothing left to be disordered? How can matter be constant? 11 January 2010 21:25 UTC www.physlink.com [Source type: Original source]
^ Units (Temperature; Pressure; Denstiy; Energy; Velocity; Viscosity; Surface Tension); Type of Data (Isothermal Properties; Isobaric Properties; Isochoric Properties; Saturation Properties)..."- Martindale's Calculators On-Line Center: Chemistry Center: R-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Animations, etc. 10 January 2010 17:12 UTC www.martindalecenter.com [Source type: Academic]
^ The dimensions of molar entropy are energy per absolute temperature and number of moles [SI unit: joule/(K·mole)].- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.^ The model defines the equations needed to calculate the molar volume , enthalpy and Gibbs free energy , based on the temperature T , pressure p and component properties.
^ Specific Heat at constant Volume .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ Units (Temperature; Pressure; Denstiy; Energy; Velocity; Viscosity; Surface Tension); Type of Data (Isothermal Properties; Isobaric Properties; Isochoric Properties; Saturation Properties)..."- Martindale's Calculators On-Line Center: Chemistry Center: R-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Animations, etc. 10 January 2010 17:12 UTC www.martindalecenter.com [Source type: Academic]
.^ The utility of these relations results from the circumstance that the pressure and expansion co efficients are familiar and easily measured, whereas the latent heat of expansion is difficult to determine.
^ In the notation of the calculus the relations become - dH/dp (0 const) = odv /do ( p const) (4) dH/dv (0 const) =odp/do ( v const) The negative sign is prefixed to dH/dp because absorption of heat +dH corresponds to diminution of pressure - dp.
^ Because the pressure increases during compression, the work of compression must be determined by the calculus integral: compression work = PdV where: P = pressure V = volume dV = the small change in volume taking place at the corresponding pressure P The integral sign indicates the summation of all the individual values of PdV. The equation relating temperature, pressure, and volume of an ideal gas is: PV = RT (2) where: P = pressure V = volume T = absolute temperature R = a constant which depends only on the amount of gas present In the case of a reversible, isothermal compression of an ideal gas we may substitute P from equation (2) into the equation for compression work.- The Second Law of Thermodynamics, Evolution, and Probability 11 January 2010 21:25 UTC www.talkorigins.org [Source type: Reference]
.^ The most instructive example of the application of relations (I) and (2) is afforded by the change of state of a substance at constant temperature and pressure.
^ Substances describable by temperature and pressure alone .- Thermodynamics - Biocrawler, the free encyclopedia 10 January 2010 17:12 UTC www.biocrawler.com [Source type: Academic]
^ Further the change of aggregation state occurs at constant temperature, so that .- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.^ Starting with unit mass of the substance in the first state (e.g.
^ If we take unit mass of the substance at B, fig.
^ If J', J" represent the values of the function for unit mass of the substance of specific volumes v' and v" in the two states at temperature 0 and pressure and if a mass m is in the state v', and 1-m in the.
liquid) possessing volume
.^ This function may be represented, for each state or phase of the system considered, by an area on the indicator diagram similar to that representing the intrinsic energy, E. The product 94, may be represented at any point such as D in Fig.
^ On the familiar indicator diagram the state of the working substance is represented by the position of a point called the " statepoint," defined by the values of the pressure p and volume v of unit mass, as ordinate and abscissa respectively (fig.
.^ This added heat changed the temperature of the band.
^ Specific Heat at constant Pressure .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ Substances describable by temperature and pressure alone .- Thermodynamics - Biocrawler, the free encyclopedia 10 January 2010 17:12 UTC www.biocrawler.com [Source type: Academic]
.^ If now the substance in the state B is entirely converted at constant temperature and pressure into the second state (e.g.
^ Substances describable by temperature and pressure alone .- Thermodynamics - Biocrawler, the free encyclopedia 10 January 2010 17:12 UTC www.biocrawler.com [Source type: Academic]
^ It would do away with the well-developed mathematical relationships of physical chemistry, including the effect of temperature and pressure on equilibrium constants and phase changes.- Second Law of Thermodynamics 10 January 2010 17:12 UTC www.fsteiger.com [Source type: FILTERED WITH BAYES]
- Does evolution violate the second law of thermodynamics? 10 January 2010 17:12 UTC www.takeonit.com [Source type: Original source]
- The Second Law of Thermodynamics, Evolution, and Probability 11 January 2010 21:25 UTC www.talkorigins.org [Source type: Reference]
- - Thermodynamics vs. Evolutionism - 11 January 2010 21:25 UTC www.trueorigin.org [Source type: Original source]
- A Brief Review of Thermodynamics 11 January 2010 21:25 UTC www.fsteiger.com [Source type: Original source]
saturated
vapour), in which it occupies a volume
.^ BC represents the change of volume (v" - v').
^ It is not necessary in this example that AB, CD should be adiabatics, because the change of volume BC is finite.
^ Basically, the “boundary” is simply an imaginary dotted line drawn around the volume of a something in which there is going to be a change in the internal energy of that something.- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
.^ This added heat changed the temperature of the band.
^ The heat absorbed in this change is called the latent heat of change of state, and may be represented by the symbol L'.
^ The substance is then cooled to the lower temperature 0" along the path CD, keeping it in the saturated state.
.^ Equations of state - Heat capacity and specific heat .- thermodynamics -- Britannica Online Encyclopedia 10 January 2010 17:12 UTC www.britannica.com [Source type: Reference]
^ He reasoned that in the chemical process, some of the energy from the system represented the energy free to do work, the rest of the energy was due simply to the heat required or generated.- Fuel Thermodynamics 10 January 2010 17:12 UTC chemcases.com [Source type: FILTERED WITH BAYES]
^ But the assumption is far from obvious for a system more complex than an ideal gas, or for states far from equilibrium, or for processes other than the simple exchange of heat and work.- OfficeRocker! : Fighting the second law of thermodynamics 11 January 2010 21:25 UTC blogs.msdn.com [Source type: General]
.^ Areas on the temperature-entropy or 0, 4, diagram represent quantities of heat in the same way as areas on the indicator diagram represent quantities of work.
^ Heat and Work are not state variables: they depend on path (see the First Law ).- Phase Equilibria Glossary 11 January 2010 21:25 UTC www.gps.caltech.edu [Source type: Reference]
^ In the Carnot cycle this difference in heat appears as useful mechanical work.- thermodynamics Facts, information, pictures | Encyclopedia.com articles about thermodynamics 10 January 2010 17:12 UTC www.encyclopedia.com [Source type: Academic]
.^ Some of the characteristics of coaching development and activity as related to the Second Law are listed below.- The Second Law of Thermodynamics 11 January 2010 21:25 UTC coachsci.sdsu.edu [Source type: Academic]
- The Second Law of Thermodynamics 11 January 2010 21:25 UTC www-rohan.sdsu.edu [Source type: Academic]
^ The Second Law of Thermodynamics states that during any reaction the total useful energy in the universe (the energy that is useful for doing work) will decrease.- Evolution & Entropy - Second Law of Thermodynamics 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
^ Let us see a couple of explanations for the second law of thermodynamics that have been given, which ignore the dispersion theorem and the deeper relation between thermodynamic and configurational entropy.- On the Relation between Thermodynamic and Configurational Entropy, and the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.foundalis.com [Source type: Original source]
.
.^ It would do away with the well-developed mathematical relationships of physical chemistry, including the effect of temperature and pressure on equilibrium constants and phase changes.- Second Law of Thermodynamics 10 January 2010 17:12 UTC www.fsteiger.com [Source type: FILTERED WITH BAYES]
- Does evolution violate the second law of thermodynamics? 10 January 2010 17:12 UTC www.takeonit.com [Source type: Original source]
- The Second Law of Thermodynamics, Evolution, and Probability 11 January 2010 21:25 UTC www.talkorigins.org [Source type: Reference]
- - Thermodynamics vs. Evolutionism - 11 January 2010 21:25 UTC www.trueorigin.org [Source type: Original source]
- A Brief Review of Thermodynamics 11 January 2010 21:25 UTC www.fsteiger.com [Source type: Original source]
^ To compute the system’s change in energy, take it from its first to its second state, divide each infinitesimal amount of heat by the temperature that’s absorbed by the system, and add all the quantities.- Skeptic Friends Network - 2nd Law of Thermodynamics Argument Weak on Both Sides 11 January 2010 21:25 UTC www.skepticfriends.org [Source type: Original source]
^ Most systems near thermodynamic equilibrium can be described pretty well by the normal macroscopic measures such as temperature, volume and pressure.- Ralph Dumain: "The Autodidact Project": Shaun Lovejoy: "Christopher Caudwell and the Second Law of Thermodynamics" 11 January 2010 21:25 UTC www.autodidactproject.org [Source type: FILTERED WITH BAYES]
.^ It is not necessary in this example that AB, CD should be adiabatics, because the change of volume BC is finite.
^ Recall the case of an adiabatic free expansion -- the temperature does not change at all, no work is done, but the volume increases.- UNIFIED ENGINEERING Thermodynamics Chapter 7 11 January 2010 21:25 UTC ocw.mit.edu [Source type: Academic]
^ Liquid gallium is used in the nanothermometer because the gallium volume changes linearly with temperature - rising up and down the tube - at a consistent rate when the tube was exposed to different temperatures.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
.^ Specific Heat at constant Volume .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ The same equations apply to the case of fusion of a solid, if L is the latest heat of fusion, and v', s', v", s" the specific volumes and specific heats of the solid and liquid respectively.
^ For solids and liquids, we see that the difference in the specific heats is small, and γ is about 1.0.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
.^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ He also showed that the difference of the specific heats at constant pressure and volume, S - s, must be the same for equal volumes of all gases at the same temperature and pressure, being represented by the expression R/TF'(t).
^ These results for the difference and the ratio of the specific heats at constant pressure and constant volume are very important and useful.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
-
.^ If we take unit mass of the substance at B, fig.
^ The Specific Heat Capacity is the amount of heat required to change a unit mass of a substance by one degree in temperature .
^ The total entropy of the system is found by multiplying the entropy per unit mass of the substance in each state by the mass existing in that state, and adding the products so obtained.
.^ Specific Heat at constant Volume .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ An adiabatic process occurs without loss or gain of heat.- Thermodynamics - encyclopedia article - Citizendium 10 January 2010 17:12 UTC reid.citizendium.org [Source type: Academic]
- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
^ Pressure is proportional to temperature when volume is held constant.
.^ Black distinguished between the quantity (caloric) and the intensity (temperature) of heat.- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
^ In order to restore the substance to its original temperature 0' at constant pressure, it would be necessary to supply a further quantity of heat, H, represented by the area between the two adiabatics from FC down to the absolute zero.
^ S, Specific heat of gas at constant pressure.
.^ Specific Heat at constant Volume .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ T is the temperature at the surface across which the small quantities of heat flow.- "Tracing the Second Law", Feature Article, July 2007 11 January 2010 21:25 UTC www.memagazine.org [Source type: FILTERED WITH BAYES]
.^ Since the work of compression is equal to q, the heat absorbed by the surroundings, q may be substituted in equation (3) to give: q = RT dV/V (4) From equation (1) the entropy gained by the surroundings during restoration from V2 to V1 is: S = q/T (1) Substituting from equation (4): S = R dV/V Upon integrating (a calculus procedure for summing up the individual values of dV/V) we have: S = Rln(V2/V1) (5) Where ln(V2/V1) is the natural logarithm of the ratio of expanded volume to the initial volume, and S is equal to the entropy increase in the surroundings upon restoration compression from V2 to V1.- Second Law of Thermodynamics 10 January 2010 17:12 UTC www.fsteiger.com [Source type: FILTERED WITH BAYES]
- The Second Law of Thermodynamics, Evolution, and Probability 11 January 2010 21:25 UTC www.talkorigins.org [Source type: Reference]
^ At constant volume for an ideal gas, dU = TdS = C V dT, which defines the specific heat at constant volume, C V .- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ At 373.14 K (99.99°C), the boiling point of water is reached at atmospheric pressure, and further additions of heat begin to boil off some of the water at this constant temperature.- Entropy - A Basic Understanding : International site for Spirax Sarco 11 January 2010 21:25 UTC www.spiraxsarco.com [Source type: FILTERED WITH BAYES]
.
.^ And all the properties of the substance may be expressed in terms of G or J and their partial differential coefficients.
^ Since the two expressions (9) are the partial differential-coefficients of a single function E of the independent variables v and 0, we shall obtain the same result, namely d 2 E/d0dv, if we differentiate the first with respect to v and the second with respect to 0.
^ The values of the partial differential coefficients in terms of n and c are as follows: - Substituting these values in equations already given, we find, from (6) S - s =R(I +nc/V)2 (24) „ (9) dE/dv (o const) =ncp/V .
.^ Specific Heat at constant Volume .- Thermodynamics 10 January 2010 17:12 UTC gphysics.net [Source type: Academic]
^ Since the amounts of heat supplied at constant pressure from E to F and from E to C are in the limit proportional to the expansions EF and EC which they produce, the ratio S/s is equal to the ratio ECÆF. EF is the change of volume corresponding to a change of pressure BE when no heat is allowed to escape and the path is the adiabatic BF, EC is the change of volume for the same change of pressure BE when the path is the isothermal BC. These changes of volume are directly as the compressibilities, or inversely as the elasticities.
^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
.^ If we write K for the adiabatic elasticity , and k for the isothermal elasticity, we obtain S/s = ECÆF = K/k.
^ K, k, Adiabatic and isothermal elasticities.
...
.^ The value of the specific heat S at constant pressure can always be determined by experiment, and in practice is one of the most important thermodynamical properties of a substance.
^ It is generally taken as constant, but its value at moderate pressures is difficult to determine.
^ Specific heat of gas at constant volume.
.^ The value of the specific heat s at constant volume can also be measured in a few cases, but it is generally necessary to deduce it from that at constant pressure, by means of relation (6).
^ It is generally taken as constant, but its value at moderate pressures is difficult to determine.
^ Specific heat of gas at constant volume.
.^ Constant pressure expansion/compression work.- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
^ The coefficient of expansion at constant pressure is equal to the coefficient of increase of pressure at constant volume.
^ Isothermal - Describes a process for which the temperature is constant.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
.^ The amount of heat absorbed in any small change of state, as from E to G in fig.
^ To compute the system’s change in energy, take it from its first to its second state, divide each infinitesimal amount of heat by the temperature that’s absorbed by the system, and add all the quantities.- Skeptic Friends Network - 2nd Law of Thermodynamics Argument Weak on Both Sides 11 January 2010 21:25 UTC www.skepticfriends.org [Source type: Original source]
^ The equation states the following: The change in entropy of a system is equal to the heat flowing into the system divided by the temperature (in degrees Kelvin).- Physics: The Laws of Thermodynamics - CliffsNotes 11 January 2010 21:25 UTC www.cliffsnotes.com [Source type: FILTERED WITH BAYES]
.^ Both the volume and temperature change.- Physics: The Laws of Thermodynamics - CliffsNotes 11 January 2010 21:25 UTC www.cliffsnotes.com [Source type: FILTERED WITH BAYES]
^ This added heat changed the temperature of the band.
^ For systems at constant pressure, the absorption of heat results in both a temperature rise and an expansion in volume .- New Page 1 10 January 2010 17:12 UTC www.eng.uc.edu [Source type: Academic]
.^ We thus obtain the relation ds/dv(o const) =od 2 p/d0 2 (v const),.
^ The equation to these lines in terms of v and 0 is obtained by integrating dE=sd0+(Odp/de - p)dv = o .
^ Differentiating equation (17) at constant pressure to find dv/do, and observing that dcldO= - nc/O, we find by substitution in (is) the following simple expression for the cooling effect do/dp in terms of c and b, Sdo/dp= (n+I)c - b..
.
.^ The first is equivalent to measuring the heat along the path EBG, the second along the path ECG. The two differ by the area BEC, which can be neglected if the change is small.
^ This is the basis of calorimetry, where the work done is equivalent to and is measured as the change in heat of the system.
^ There are two different heat capacities.- New Page 1 10 January 2010 17:12 UTC www.eng.uc.edu [Source type: Academic]
.^ For a finite change it is necessary to represent the path by a series of small steps, which is the graphic equivalent of integration along the path represented by the given relation between v and 0, or p and 0.
^ If we put dH=o in equations (8), we obtain the relations between dv and do, or dp and do, under the condition of no heat-supply, i.e.
^ The TdS equations relate the specific heats to the entropy and to derivatives of the equation of state.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
Missing image
Thermodynamics-3.jpg
6.
Intrinsic Energy. - . change of intrinsic energy
E along any path is found by subtracting the work pdv from
either of the expressions for
dH. Since the change of
energy is independent of the path, the finite change between any
two given states may be found by integration along
any
convenient path.
^ The change of intrinsic energy E along any path is found by subtracting the work pdv from either of the expressions for dH. Since the change of energy is independent of the path, the finite change between any two given states may be found by integration along any convenient path.
^ The expression for the change of entropy between any two states is found by dividing either of the expressions for dH in (8) by 0 and integrating between the given limits, since dH/B is a perfect differential.
^ For a finite change it is necessary to represent the path by a series of small steps, which is the graphic equivalent of integration along the path represented by the given relation between v and 0, or p and 0.
.^ It is generally convenient to divide the path into two steps, isothermal and isometric, or isothermal and isopiestic, and to integrate along each separately.
^ One could just as easily use a statistical argument - divide a reaction vessel into enough separate compartments, and it is virtually certain that some very unlikely reaction path will occur in one of them.- Evolution myths: Evolution violates the second law of thermodynamics - life - 16 April 2008 - New Scientist 11 January 2010 21:25 UTC www.newscientist.com [Source type: FILTERED WITH BAYES]
^ The change of intrinsic energy E along any path is found by subtracting the work pdv from either of the expressions for dH. Since the change of energy is independent of the path, the finite change between any two given states may be found by integration along any convenient path.
.^ Infinitesimal changes at constant temperatures in these energies are expressed as .
^ Both the volume and temperature change.- Physics: The Laws of Thermodynamics - CliffsNotes 11 January 2010 21:25 UTC www.cliffsnotes.com [Source type: FILTERED WITH BAYES]
^ So q is not a state function, w is not a state function but DE and E the internal energy are state functions.- Chemistry: The First Law of Thermodynamics | MindBites.com 11 January 2010 21:25 UTC www.mindbites.com [Source type: FILTERED WITH BAYES]
.^ If u(x,y) is a function of two variables, then it is an exact function and its total derivative is an exact differential if the total differential of u may be written and the second partial derivatives obey the reciprocal relation .- Phase Equilibria Glossary 11 January 2010 21:25 UTC www.gps.caltech.edu [Source type: Reference]
^ Since the two expressions (9) are the partial differential-coefficients of a single function E of the independent variables v and 0, we shall obtain the same result, namely d 2 E/d0dv, if we differentiate the first with respect to v and the second with respect to 0.
^ They were given that name because, in the 19th century, they were first discovered in relation to steam engines.- LAWS OF NATURE VS. EVOLUTION - 1 11 January 2010 21:25 UTC www.pathlights.com [Source type: Original source]
.. (io) FIG. 2.
Missing image
Thermodynamics-4.jpg
FIG. 3.
which is useful for calculating the variation of the specific
heat s with variation of
.^ In the special case when there are no external forces such as gravity or electrostatic interactions, the density and temperature are constant, with v 0 = 0, and by summing over all 3-D space, Eq.
^ If the density (and kinetic energy) of electrons decreases at constant temperature and pressure, the number of charge electrons decreases, thus decreasing the kinetic energy of the orbital electrons .- Westlund Tech Claims Second Law of Thermodynamics is Invalid 11 January 2010 21:25 UTC www.pureenergysystems.com [Source type: FILTERED WITH BAYES]
^ At a constant temperature and pressure, the kinetic energy of electrons is determined by their density.- Westlund Tech Claims Second Law of Thermodynamics is Invalid 11 January 2010 21:25 UTC www.pureenergysystems.com [Source type: FILTERED WITH BAYES]
.^ Specific heat of gas at constant volume.
^ S, Specific heat of gas at constant pressure.
^ (I I) This expression shows that the rate of variation of the total heat with temperature at constant pressure is equal to the specific heat at constant pressure.
7. Total Heat. -
.^ The function F= (E+pv), like E itself, has a value depending only on the state of the body.
^ The value and sign of this dc voltage, like the one of the persistent current, depend in a periodical way on a magnetic field with period corresponded to the flux quantum within the loop.- New Challenges to the Second Law - Quantum Limits to the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.ipmt-hpm.ac.ru [Source type: Academic]
^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
.^ See Terms of Use for details.- Thermodynamics/The Second Law of Thermodynamics - Wikiversity 11 January 2010 21:25 UTC en.wikiversity.org [Source type: Academic]
^ It was called the latent heat L, and the term is still used.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ It may conveniently be called the Total Heat, by a slight extension of the meaning of a term which has been for a long time in use as applied to vapours (see Vaporization ).
.^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ He also showed that the difference of the specific heats at constant pressure and volume, S - s, must be the same for equal volumes of all gases at the same temperature and pressure, being represented by the expression R/TF'(t).
^ Specific heat of gas at constant volume.
.^ For instance, a heat engine has a high-temperature heat reservoir at a single well-defined temperature, T H .
^ Steam engines are a good example of a heat engine.- The second law of thermodynamics - Total equilibrium and heat engines. 11 January 2010 21:25 UTC www.flyingturtle.org [Source type: Original source]
^ Find the change in enthalpy for water that is heated from 125 °C to 225 °C at constant pressure of 1 bar.
.^ Steam engines How Steam engines work .
^ The total heat with which we are actually concerned in the working of a steam engine is the total heat as here defined, and not the total heat as defined by Regnault, which, however, differs from ( E+pv ) only by a quantity which is inappreciable in ordinary practice.
^ This allows to define the main difference between work (w) and heat (q).- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ When temperature and pressure are held constant, the Gibbs function is a minimum at equilibrium.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ One such variable of state is temperature.- Second Law of Thermodynamics - SkepticWiki 11 January 2010 21:25 UTC www.skepticwiki.org [Source type: Original source]
^ Energy required heating up substances .
.^ Constant pressure lines on the T - s diagram.- The Design of Gas Turbine Engines-Thermodynamics and Aerodynamics-2nd Ed: CD ROM & DVD - CD-ROM 11 January 2010 21:25 UTC catalog.asme.org [Source type: Academic]
^ Unfortunately, the constant total heat lines shown in a T - S diagram are curved, which makes it difficult to follow changes in such free and unrestricted expansions as those when steam is allowed to flow through and expand after a control valve.- Entropy - A Basic Understanding : International site for Spirax Sarco 11 January 2010 21:25 UTC www.spiraxsarco.com [Source type: FILTERED WITH BAYES]
^ If we combine the first and second laws as expressed in equations 7-1 and 7-2 and replace the mechanical work term W by P V, where P is pressure and V is volume change, we obtain, [NOTE: Volume expansion ( V> 0) corresponds to the system doing work, and therefore losing energy.- Thermodynamics of Living Systems 10 January 2010 17:12 UTC www.ldolphin.org [Source type: Academic]
.^ The equation to the lines of constant total heat is found in terms of p and 0 by putting dF=o and integrating (it).
^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ When heat is transformed into any other form of energy, or when other forms of energy are transformed into heat, the total amount of energy (heat plus other forms) in the system is constant .- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
8. Ideal Gases
.^ In practice, the temperature is extrapolated to zero pressure, where the gas will be ideal in fact.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ Thermodynamic Temperature Scale - A temperature scale that is independent of the properties of the substances that are used to measure temperature.- Thermodynamics Definitions and Terminology - Engineers Edge 10 January 2010 17:12 UTC www.engineersedge.com [Source type: Reference]
^ A gas will always migrate from an area of high pressure to one of low pressure.- The Second Law of Thermodynamics :: CESE :: Coalition for Excellence in Science and Math Education 11 January 2010 21:25 UTC www.cesame-nm.org [Source type: Original source]
.^ It has the characteristic equation pv=Re, and obeys Boyle's law at all temperatures.
^ If the fluid is a gas also obeying Boyle's law, pv = f (0), then it must be an ideal gas.
^ Thomas Andrew , in a series of experiments with CO 2 through 1869, finds that at low temperatures Boyle's law breaks down, and there are regions on a PV chart where, for a given isotherm, changes in volume produce no change in pressure.- Sketching the History of Statistical Mechanics and Thermodynamics 11 January 2010 21:25 UTC omega.math.albany.edu:8008 [Source type: Academic]
.^ The coefficient of expansion at constant pressure is equal to the coefficient of increase of pressure at constant volume.
^ At constant volume and pressure: .- THERMODYNAMICS FOR CHEMICAL ENGINEERS 10 January 2010 17:12 UTC www.assignmenthelp.net [Source type: Academic]
^ R is the molar gas constant , p the pressure, and V the volume of the gas.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ These results for the difference and the ratio of the specific heats at constant pressure and constant volume are very important and useful.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ Specific heat of gas at constant volume.
.^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ Sdo, the heat absorbed in isothermal expansion as given by relations (4).
^ No work is done and therefore no heat flows in the isothermal free expansion: .- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ Heat is a form of energy.
^ At a constant temperature and pressure, the kinetic energy of electrons is determined by their density.- Westlund Tech Claims Second Law of Thermodynamics is Invalid 11 January 2010 21:25 UTC www.pureenergysystems.com [Source type: FILTERED WITH BAYES]
^ S, Specific heat of gas at constant pressure.
.^ The last partial is just the ratio of dp to dV in this case, when dS = 0.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ Total energy change.- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
.^ Specific heats of different types of gases: .- THERMODYNAMICS FOR CHEMICAL ENGINEERS 10 January 2010 17:12 UTC www.assignmenthelp.net [Source type: Academic]
^ S, Specific heat of gas at constant pressure.
^ A difference in temperature causes heat to flow.
If we assume that
s is a linear
function of
0, s= so(I
+aO), the adiabatic
equation takes the form,
s 0 log e OW
+aso(0 - Oo) +R
loge(v/vo) =o
(14) where (00,v), (e 0, vo) are any two points on the adiabatic.
.^ Recall that the changes in Gibbs free energy with pressure and temperature are given by two of Maxwell's relations = r V and = - r S If we recast these as = r V P and = - r S T and integrate, we get r GdP = r G P - r G P ref = r VdP or r G P = r G P ref + r VdP and r GdT = r G T - r G T ref = - r SdT or r G T = r G T ref - r SdT thus r G PT = r G P ref T ref + r VdP - r SdT Solving the Pressure Integral at Constant Temperature .- Thermodynamics Notes 10 January 2010 17:12 UTC www.geol.ucsb.edu [Source type: Academic]
^ These energy states at the atomic level change in predictable ways when heating up an aqueous solution, for example.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
^ Heat and work are two methods of adding energy to or subtracting energy from a system.
-
.^ Define and explain the First Law of Thermodynamics.
^ Since no gas is ideally perfect, it is most important for practical purposes to discuss the deviations of actual gases from the ideal state, and to consider how their properties may be thermodynamically explained and defined.
^ Define and explain the Second Law of Thermodynamics.
.^ The most natural method of procedure is to observe the deviations from Boyle's law by measuring the changes of pv at various constant temperatures.
^ The development of life may have only violated one law of science, but that was the one Sir Arthur Eddington called the “supreme” law of Nature, and it has violated that in a most spectacular way.- CSI | Does Evolution Have a Thermodynamics Problem? 10 January 2010 17:12 UTC www.csicop.org [Source type: Original source]
^ Trans., 1854, 1862) found that the cooling effect, do, was of the same order of magnitude as the deviations from Boyle's law in each case, and that it was proportional to the difference of pressure, dp, so that d0/dp was nearly constant for each gas over a range of pressure of five or six atmospheres.
.^ In other words, any entropy change is proportional to the logarithm of the ratio of probabilities.- The Second Law of Thermodynamics, Evolution, and Probability 11 January 2010 21:25 UTC www.talkorigins.org [Source type: Reference]
^ It is found by experiment that the change of pv with pressure at moderate pressures is nearly proportional to the change of p, in other words that the coefficient d(pv)/dp is to a first approximation a function of the temperature only.
^ To compute the system’s change in energy, take it from its first to its second state, divide each infinitesimal amount of heat by the temperature that’s absorbed by the system, and add all the quantities.- Skeptic Friends Network - 2nd Law of Thermodynamics Argument Weak on Both Sides 11 January 2010 21:25 UTC www.skepticfriends.org [Source type: Original source]
.^ The most natural method of procedure is to observe the deviations from Boyle's law by measuring the changes of pv at various constant temperatures.
^ Using the gas law, we can express both pressure and temperature in terms of and .- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
^ This coefficient is sometimes called the " angular coefficient," and may be regarded as a measure of the deviations from Boyle's law, 'which may be most simply expressed at moderate pressures by formulating the variation of the angular coefficient with temperature.
.^ In practice, the temperature is extrapolated to zero pressure, where the gas will be ideal in fact.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ In time, the ideal gas law was formulated.- Thermodynamics - encyclopedia article - Citizendium 10 January 2010 17:12 UTC reid.citizendium.org [Source type: Academic]
^ Note that, if it were not an ideal gas, would also depend on p .
.^ A sufficient test, in addition to Boyle's law, is the condition dE/dv=o at constant temperature.
^ From Boyles' Law, we know that the pressure is directly proportional to the temperature, therefore, it was shown that the kinetic energy of the molecules related directly to the temperature of the gas.- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
^ At 373.14 K (99.99°C), the boiling point of water is reached at atmospheric pressure, and further additions of heat begin to boil off some of the water at this constant temperature.- Entropy - A Basic Understanding : International site for Spirax Sarco 11 January 2010 21:25 UTC www.spiraxsarco.com [Source type: FILTERED WITH BAYES]
.^ This test was applied by Joule in the well-known experiment in which he allowed a gas to expand from one vessel to another in a calorimeter without doing external work.
^ Equation (1) gives the sufficient condition that the entropy S is a state function.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
^ Also, the equation applies to non-equilibrium conditions.- Discussion with a Creationist aboutthe Second Law of Thermodynamics 11 January 2010 21:25 UTC www.fred.net [Source type: Original source]
.^ As the temperature increases, the probability of the higher energies increases.- Thermodynamics 10 January 2010 17:12 UTC www.slideshare.net [Source type: FILTERED WITH BAYES]
^ The kinetic energy contributes to an increase in temperature, the potential energy contributes to an increase in heat capacity.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
^ Under this condition the increase of intrinsic energy would be equal to the heat absorbed, and would be indicated by fall of temperature of the calorimeter.
.^ When the gas expands, d x is positive, and the gas does positive work.
^ When heat is transferred to the system, the gas expands, it does work on the surroundings and the temperature and pressure decrease.
^ The change in entropy on expansion is therefore .- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ But owing to the large thermal capacity of his calorimeter, the test, though sufficient for his immediate purpose, was not delicate enough to detect and measure the small deviations which actually exist.
^ (This is an extremely small quantity of heat: roughly one ten-billionth of the heat actually generated by existing electronic circuits.- Demons, Engines and the Second Law 11 January 2010 21:25 UTC www.aeiveos.com [Source type: Original source]
^ The thermal properties of water displaying a large heat capacity can explain regulation of temperature in organisms.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
to.
.^ Method of Joule and Thomson.
-
.^ William Thomson (Baron Kelvin of Largs) : 1852 formulation of the second law of thermodynamics and description of an absolute temperature scale.- Selected Classic Papers from the History of Chemistry 10 January 2010 17:12 UTC webserver.lemoyne.edu [Source type: Academic]
^ The first and second laws of thermodynamics emerged simultaneously in the 1850s, primarily out of the works of William Rankine , Rudolf Clausius , and William Thomson (Lord Kelvin).- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
^ In the “diet wars” the first law of thermodynamics has been thrown around a lot.- Science-Based Medicine » Calories, Thermodynamics, and Weight 10 January 2010 17:12 UTC www.sciencebasedmedicine.org [Source type: FILTERED WITH BAYES]
.^ A continuous stream of gas, supplied at a constant pressure and temperature, is forced through a porous plug, from which it issues at a lower pressure through an orifice carefully surrounded with non-conducting material, where its temperature is measured.
^ S, Specific heat of gas at constant pressure.
^ R is the molar gas constant , p the pressure, and V the volume of the gas.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.^ Class 2D-STREAM-KINETIC-ENERGY .- Ontolingua Theory THERMODYNAMICS 10 January 2010 17:12 UTC www-ksl.stanford.edu [Source type: Reference]
^ If we consider any short length of the stream bounded by two imaginary cross-sections A and B on either side of the plug, unit mass of the fluid in passing A has work, p'v', done on it by the fluid behind and carries its energy, E'+ U', with it into the space AB, where U' is the kinetic energy of flow.
^ Heat energy is transformed into work energy.- The second law of thermodynamics - Total equilibrium and heat engines. 11 January 2010 21:25 UTC www.flyingturtle.org [Source type: Original source]
.^ We can readily see the difficulty in getting polymerization reactions to occur under equilibrium conditions, i.e., in the absence of such an energy flow.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
- Thermodynamics and the Origin of Life 11 January 2010 21:25 UTC www.ldolphin.org [Source type: Academic]
^ The coupling of energy flow to the specific work requirements in the formation of DNA and protein is particularly important since the required configurational entropy work of coding is substantial.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
^ In this case, the S e term represents the negative entropy, or organizing work done on the system as a result of both energy and mass flow through the system.- Thermodynamics of Living Systems 10 January 2010 17:12 UTC www.ldolphin.org [Source type: Academic]
- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ It is easy to arrange the experiment so that U is small and nearly constant.
^ The tires may expand a little, but we assume this effect is small, so the volume is nearly constant.
.^ For our proof of the efficiency of the Carnot engine, we need only the ratio of Q H to Q L , so we neglect constants of proportionality, and simply subsitutde P ∝ T / V , giving The efficiency of a heat engine is .
^ The equation relating temperature, pressure, and volume of an ideal gas is: PV = RT (2) where: P = pressure V = volume T = absolute temperature R = a constant which depends only on the amount of gas present In the case of a reversible, isothermal compression of an ideal gas we may substitute P from equation (2) into the equation for compression work.- Second Law of Thermodynamics 10 January 2010 17:12 UTC www.fsteiger.com [Source type: FILTERED WITH BAYES]
^ The equation to the lines of constant total heat is found in terms of p and 0 by putting dF=o and integrating (it).
...
.^ Such a system is only possible at the temperature and pressure corresponding to the Triple point.
^ In the notation of the calculus the relations become - dH/dp (0 const) = odv /do ( p const) (4) dH/dv (0 const) =odp/do ( v const) The negative sign is prefixed to dH/dp because absorption of heat +dH corresponds to diminution of pressure - dp.
^ This means that at a given temperature, water in the gas phase will evaporate or condense until the corresponding equilibrium water vapor pressure is reached.
.^ If there is no fall of temperature in passing the plug, d0 = o, and we have the condition Odv/d0 =v.
^ My previous point, that there is no temperature defined for a nano-scale system, was wrong .- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ Careful measurements show that this process occurs without a change in temperature, so there is no energy input or released during the mixing.- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
.^ We now impose the second constraint on the form of the function f: the nature of f must be such that S doubles when the amount of material in the system (N) doubles.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ Since S total = S ( W total ) , S 1 = S ( W 1 ) , and W total = ( W 1 , × , W 1 ) , then our new function S must satisfy the equation S ( ( W 1 , × , W 1 ) ) = S ( W 1 ) + S ( W 1 ) The only function S which will satisfy this equation is the logarithm function, which has the property that ln ( ( x , × , y ) ) = ln x + ln y .- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
^ By multiplying the distribution function with the power of the velocity, e.g., v 0 , v 1 , and v 2 , the continuity equation, Navier-Stokes equations, and conservation of energy respectively in fluid dynamics can be derived directly from Eq.
.^ Moles of gas are calculated by the ideal gas law: .- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ If the fluid is a gas also obeying Boyle's law, pv = f (0), then it must be an ideal gas.
^ In time, the ideal gas law was formulated.- Thermodynamics - encyclopedia article - Citizendium 10 January 2010 17:12 UTC reid.citizendium.org [Source type: Academic]
.^ As the result of their experiments on actual gases (air, hydrogen , and C02), Joule and Thomson ( Phil.
^ Thomson, W. (1851) On the dynamical theory of heat; with numerical results deduced from Mr. Joule’s equivalent of a thermal unit and M. Regnault’s observations on steam, Math.- Second Law of Thermodynamics - a knol by Claes Johnson 10 January 2010 17:12 UTC knol.google.com [Source type: FILTERED WITH BAYES]
^ The values of F'(t) calculated previously by Sir W. Thomson (Lord Kelvin) from Regnault's tables of the properties of steam, assuming the gaseous laws, did not vary exactly as J/T. Joule's experiments on the equivalence of W and H were not sufficiently precise to decide the question.
.^ S, Specific heat of gas at constant pressure.
^ R is the molar gas constant , p the pressure, and V the volume of the gas.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
^ Trans., 1854, 1862) found that the cooling effect, do, was of the same order of magnitude as the deviations from Boyle's law in each case, and that it was proportional to the difference of pressure, dp, so that d0/dp was nearly constant for each gas over a range of pressure of five or six atmospheres.
.^ This is the difference between the pressure we want to find and atmospheric pressure at the surface.
^ By experiments at different temperatures between o° and 00° C., they found that the cooling effect per atmosphere of pressure varied inversely as the square of the absolute temperature for air and CO 2 .
^ He remarks that ” the law according to which the motive power of heat varies at different points of the thermometric scale is intimately connected with that of the variations of the specific heats of gases at different temperatures - a law which experiment has not yet made known to us with sufficient exactness."
.^ On a small log line, one can find various types of headrigs, ranging from a chipper-canter to a completely integrated machine centre like a four-sided canter..."- Martindale's Calculators On-Line Center: Mechanical Engineering: S-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Animations, etc. 10 January 2010 17:12 UTC www.martindalecenter.com [Source type: Academic]
^ By experiments at different temperatures between o° and 00° C., they found that the cooling effect per atmosphere of pressure varied inversely as the square of the absolute temperature for air and CO 2 .
^ It was decided that this type of experiment could present problems in some classroom settings.
.^ The ideal gas equation of state is .
^ It has the characteristic equation pv=Re, and obeys Boyle's law at all temperatures.
^ The equation of state of one mole of an ideal gas is .- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.
.^ An equation of a similar form had previously been employed by Rankine ( Trans.
Roy. Soc.
.^ Ed., 1854) to represent Regnault's experiments on the deviations of CO 2 from.
^ The value of the co-aggregation volume, c, at any temperature, assuming equation (17), may be found by observing the deviations from Boyle's law and by experiments on the Joule-Thomson effect.
Boyle's law.
.^ This equation is practically identical for moderate pressures with that devised by Clausius ( Phil.
.^ Mag., 1880) to represent the behaviour of CO 2 up to the critical point.
^ Near the point of crossover from the realm of thermodynamic disorder to the domain of coherence, molecular fluctuations play a critical role in the behaviour of the system.- Ralph Dumain: "The Autodidact Project": Shaun Lovejoy: "Christopher Caudwell and the Second Law of Thermodynamics" 11 January 2010 21:25 UTC www.autodidactproject.org [Source type: FILTERED WITH BAYES]
.^ Experiments by Natanson on CO 2 at 17° C. confirm those of Joule and Thomson, but show a slight increase of the ratio do/dp at higher pressures, which is otherwise rendered probable by the form of the isothermals as determined by Andrews and Amagat.
^ As the temperature increases, the probability of the higher energies increases.- Thermodynamics 10 January 2010 17:12 UTC www.slideshare.net [Source type: FILTERED WITH BAYES]
^ Of greater interest, particularly from a historical point of view, are the original papers of Joule, Thomson and Rankine, some of which have been reprinted in a collected form.
.^ More recent experiments by J. H. Grindley ( Proc.
Roy.
.^ Soc., 1900, 66, p.
79)
and Callendar (Proc. Roy. Soc., 1900) on steam confirm this type of
equation, but give much larger values of the cooling effect than
for C02, and a more rapid rate of variation with
temperature.
.^ I I. Modified Joule-Thomson Equation.
^ The value of the co-aggregation volume, c, at any temperature, assuming equation (17), may be found by observing the deviations from Boyle's law and by experiments on the Joule-Thomson effect.
^ In the modified Joule-Thomson equation (17), both c and n have simple theoretical interpretations, and it is possible to express the thermodynamical properties of the substance in terms of them by means of reasonably simple formulae.
-
.^ G. A. Hirn ( Theorie Mec.
de la Chaleur, ii. p.
.^ Any gas is specified by its temperature , the volume it occupies and its pressure .- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
^ R is the molar gas constant , p the pressure, and V the volume of the gas.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
^ Gas in a container is at a pressure of 1.5 atm and a volume of 4 m 3 .
.^ Suppose the pressure in the two gases is identical.- On the Relation between Thermodynamic and Configurational Entropy, and the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.foundalis.com [Source type: Original source]
^ (See reference 2 for what we mean by “function of state”.- Thermodynamics and Differential Forms 10 January 2010 17:12 UTC www.av8n.com [Source type: Academic]
^ The above equation could have been written .- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
.^ Specific natural processes > > to which can be attributed the entropy decreases necessarily > > associated with the generation of these things have similarly > > not been empirically and unequivocally demonstrated.- Discussion with a Creationist aboutthe Second Law of Thermodynamics 11 January 2010 21:25 UTC www.fred.net [Source type: Original source]
^ (One can’t help but wonder whether this paragraph is meant as an attempt to go beyond the myth of spontaneous generation to suggest the notion of spontaneous resurrection!- - Thermodynamics vs. Evolutionism - 11 January 2010 21:25 UTC www.trueorigin.org [Source type: Original source]
^ For example: water which is in a gaseous state (steam) can release energy in change from gas to liquid while not changing temperature, although the pressure does change.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
.^ For some substances, the magnetic susceptibility varies inversely as the temperature.- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
^ The simplest assumption which suffices to express the small deviations of gases and vapours from the ideal state at moderate pressures is that the coefficient a in the expression for the capillary pressure varies inversely as some power of the absolute temperature.
^ From the ideal gas law, the ratio of the pressures is the same as the ratio of the absolute temperatures, .
.^ In working to a first approximation, the small term nc/V may be omitted in the expression for s.
^ We can re-order the terms in the above equation to calculate the critical size of the nucleus r c r c = -2 / ( V G + ) If, at the critical radius, n G = G*, the activation energy for nucleation is G* = 16 3 / 3( V G + ) 2 Growth .- Thermodynamics Notes 10 January 2010 17:12 UTC www.geol.ucsb.edu [Source type: Academic]
^ If we combine the first and second laws as expressed in equations 7-1 and 7-2 and replace the mechanical work term W by P V, where P is pressure and V is volume change, we obtain, .- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ V =Re/p due to co- aggregation of the molecules) which varies inversely as the nth power of 0, but is independent of p to a first approximation at moderate pressures.
^ If we combine the first and second laws as expressed in equations 7-1 and 7-2 and replace the mechanical work term W by P V, where P is pressure and V is volume change, we obtain, [NOTE: Volume expansion ( V> 0) corresponds to the system doing work, and therefore losing energy.- Thermodynamics of Living Systems 10 January 2010 17:12 UTC www.ldolphin.org [Source type: Academic]
^ The simplest assumption which suffices to express the small deviations of gases and vapours from the ideal state at moderate pressures is that the coefficient a in the expression for the capillary pressure varies inversely as some power of the absolute temperature.
.^ The constant co is the value of c at some standard temperature oo.
^ An example of a heat bath is a swimming pool maintained at some constant temperature.- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
^ Denoting by So, so, these constant limiting values at p=o, we may obtain the values at any pressure by integrating the expressions (27) and (28) from co to v and from o to p respectively.
.^ States of monolayers in p -A isotherms The type of a monolayer formed (with characteristic p -A isotherms) by different lipids will depend on the intermolecular forces between the molecules at the surface.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
^ A bacterium is more complex, more differentiated, possessing a cell wall and different types of molecules and a metabolism.- Evolution Defying Second Law of Thermodynamics [Archive] - TeenSpot.com - Teen Message Boards 11 January 2010 21:25 UTC www.teenspot.com [Source type: Original source]
^ I prefer to avoid this dispersal of molecules in our thought experiment, because I want the thermodynamic case to appear as different as possible from the previous experiment with the gas molecules in a container that disperse in a room.- On the Relation between Thermodynamic and Configurational Entropy, and the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.foundalis.com [Source type: Original source]
.^ For CO 2 at ordinary temperatures n =2, as in the JouleThomson equation.
^ The value of the co-aggregation volume, c, at any temperature, assuming equation (17), may be found by observing the deviations from Boyle's law and by experiments on the Joule-Thomson effect.
.^ It is precariously perched between the molten core of the earth, with more energy than the systems could tolerate, and space, where temperatures approach the absolute zero your refer to.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ The universe moves from its less probable current arrangement (low entropy) toward its most probable arrangement in which the energy of the universe will be more uniformly distributed.- Thermodynamics of Living Systems 10 January 2010 17:12 UTC www.ldolphin.org [Source type: Academic]
^ In other words, an isolated system always goes from a less probable to a more probable configuration.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
.^ However, according to the formula S = Q/T, less heat need be expelled into the low temperature reservoir than is extracted from the high temperature reservoir for equal and opposite changes in entropy.- thermodynamics Facts, information, pictures | Encyclopedia.com articles about thermodynamics 10 January 2010 17:12 UTC www.encyclopedia.com [Source type: Academic]
^ In this equation, Q is a quotient of partial pressures of the gases in the reaction mixture.- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
^ And an example of this is a rock will always fall if you let go of it a great height Or high pressure will always leak into a low pressure.- Can someone please explain the The Second Law of Thermodynamics to me, with examples? | Ask MetaFilter 11 January 2010 21:25 UTC ask.metafilter.com [Source type: Original source]
.^ It is generally taken as constant, but its value at moderate pressures is difficult to determine.
^ The value of the specific heat s at constant volume can also be measured in a few cases, but it is generally necessary to deduce it from that at constant pressure, by means of relation (6).
^ The value of the specific heat S at constant pressure can always be determined by experiment, and in practice is one of the most important thermodynamical properties of a substance.
.^ According to van der Waals, assuming spherical molecules, it should be four times; according to O. E. Meyer, on slightly different assumptions, it should be 41/2 times, the actual volume of the molecules.
^ By taking into accounts the attraction between molecules and their finite size (total volume of the gas is represented by the red square in Figure 06), a more realistic equation for the real gases known as van der Waals equation was derived way back in 1873: .
^ Van der Waals bonds) exhibit sharp, large peaks in the heat capacity curve.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ Gas in a container is at a pressure of 1.5 atm and a volume of 4 m 3 .
^ It appears to be a quantity of the same order as the volume of the liquid, or as the limiting volume of the gas at very high pressures.
^ R is the molar gas constant , p the pressure, and V the volume of the gas.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.^ During the 19th century, the second law was synthesized, essentially, by studying the dynamics of the Carnot heat engine in coordination with James Joule's Mechanical equivalent of heat experiments.- Second law of thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 11 January 2010 21:25 UTC www.chemie.de [Source type: FILTERED WITH BAYES]
^ From Boyles' Law, we know that the pressure is directly proportional to the temperature, therefore, it was shown that the kinetic energy of the molecules related directly to the temperature of the gas.- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
^ We are interested in the variation of S with pressure, and we remember from Boyle's law that, for a fixed temperature, volume is inversely related to pressure.- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
.^ The value of the angular coefficient d(pv)/dp is evidently (b - c), which expresses the defect of the actual volume v from the ideal volume Re/p.
^ From the ideal gas law PV=nRT , the volume of such a sample can be used as an indicator of temperature; in this manner it defines temperature.- Thermodynamics - encyclopedia article - Citizendium 10 January 2010 17:12 UTC reid.citizendium.org [Source type: Academic]
- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
^ These must be expressed as functions of v and 0, which is theoretically possible if the values of s, p, and dp/do are known.
.^ The difference of the specific heats by equation (6) is constant and equal to R. The isothermal elasticity - v(dp/dv) is equal to the pressure p.
^ During this constant-volume reheating, we have PV = nkT , so the amount of pressure regained is a direct indication of how much the gas cooled down when it lost an amount of energy Δ E .
^ It would do away with the well-developed mathematical relationships of physical chemistry, including the effect of temperature and pressure on equilibrium constants and phase changes.- Second Law of Thermodynamics 10 January 2010 17:12 UTC www.fsteiger.com [Source type: FILTERED WITH BAYES]
.
.^ Experiments at two temperatures suffice to determine both c and n if we assume that b is equal to the volume of the liquid.
^ If experiments show that the two partial derivatives are equal, the second law is confirmed.- BIASED THERMAL MOTION AND THE SECOND LAW OF THERMODYNAMICS 11 January 2010 21:25 UTC wbabin.net [Source type: FILTERED WITH BAYES]
^ Moreover entropy cannot be measured directly, there is no such thing as an entropy meter, whereas state parameters like volume and temperature are easily determined.- Entropy (thermodynamics) - encyclopedia article - Citizendium 10 January 2010 17:12 UTC locke.citizendium.org [Source type: Academic]
.^ But it is better to apply the Boyle's law test in addition, provided that errors due to, surface condensation can be avoided.
^ If lifting is due to an additional pressure generated within the bulk, as assumed by Panofsky and Phillips, then water will leak through the hole and the second law will be violated.- BIASED THERMAL MOTION AND THE SECOND LAW OF THERMODYNAMICS 11 January 2010 21:25 UTC wbabin.net [Source type: FILTERED WITH BAYES]
^ The Second Law is simple in principle, but applying it to real systems can be difficult due to the challenge of determining probabilities at the microscopic level.- Evolution & Entropy - Second Law of Thermodynamics 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
.^ The advantage of this type of equation is that c is a function of the temperature only.
^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
^ This equation gives us an opportunity to define a temperature scale, by choosing the function f.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
.^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
^ The standard transformed enthalpy of reaction r H' o can be calculated with the van't Hoff equation from apparent equilibrium constants which have been determined as a function of temperature.- Thermodynamics of Enzyme-Catalyzed Reactions 10 January 2010 17:12 UTC xpdb.nist.gov [Source type: Academic]
^ Van der Waals bonds) exhibit sharp, large peaks in the heat capacity curve.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ These have often been employed as empirical formulae (e.g.
.^ Zeuner's formula for steam), but they cannot be made to represent with sufficient approximation the deviations from the ideal state at moderate pressures and generally lead to erroneous results.
^ V =Re/p due to co- aggregation of the molecules) which varies inversely as the nth power of 0, but is independent of p to a first approximation at moderate pressures.
^ Many practical examples approximate the conditions of uniform state and uniform flow sufficiently well for engineering calculations.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
In the
modified Joule-Thomson equation (17), both c
and n have
simple theoretical interpretations, and it is possible to express
the thermodynamical properties of the substance in terms of them by
means of reasonably simple formulae.
|
dv/dO (p const) = (R/p) (I +nc/V)..
|
(19)
|
|
d 2 v/d0 2 „ _ - n(n+ I)c/e 2. .
|
20)
|
|
dp/do (v const) = (R/V) (I +nc/V).
|
21)
|
|
d 2 p/d0 e „ =Rnc(I - n+2ne/V)/0V 2.
|
(22)
|
|
d(pv)/dp(o const) = b - c
|
. (23)
|
.^ Application of the Modified Equation.
-
.^ We may take equation (17) as a practical example of the thermodynamical principles already given.
^ Consequently, we are talking here non-equlibrium thermodynamics/statistical mechanics, for which there is no minimum principle, just Liouville's equation (classically).- 'Evolution as Described by the Second Law of Thermodynamics' by PhysoOrg - RichardDawkins.net 11 January 2010 21:25 UTC richarddawkins.net [Source type: FILTERED WITH BAYES]
^ Thermodynamic laws are concerned with the relationship between thermal energy properties of a system and are given as mathematical equations or equations of state (literally meaning an equation describing the relationship between properties of a system).- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
^ This gives TdS = C V dT + T(∂p/∂T) V dV. Now dS is given in terms of experimentally measurable quantities only.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ The last partial is just the ratio of dp to dV in this case, when dS = 0.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
..)
.^ Under these assumptions the equation is as follows: .- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ In order to deduce the complete variation of the specific heats from these equations, it is necessary to make some assumption with regard to the variation of the specific heats with temperature.
^ He remarks that ” the law according to which the motive power of heat varies at different points of the thermometric scale is intimately connected with that of the variations of the specific heats of gases at different temperatures - a law which experiment has not yet made known to us with sufficient exactness."
.^ (A more complex molecule could rotate and vibrate as well.
^ The total kinetic energy is an extensive quantity.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ Internal Energy - The internal energy ( U ) of a system is the total energy due to the motion of molecules, plus the rotation, and vibration of atoms within molecules.
.^ At constant volume for an ideal gas, dU = TdS = C V dT, which defines the specific heat at constant volume, C V .- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ In this case, all gases behave like an "Ideal Gas" and have a very simple relation between their pressure, volume, and temperature: pV= (constant)T. This temperature is called the thermodynamic temperature and is now accepted as the fundamental measure of temperature.- About Temperature 10 January 2010 17:12 UTC eo.ucar.edu [Source type: Academic]
^ A crucial observation is that although solids and liquids are nearly incompressible, gases can be compressed, as when we increase the amount of air in a car's tire while hardly increasing its volume at all.
.^ So, there is no reason for amusement.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ The entropy is therefore zero at zero temperature.
^ In practice, the temperature is extrapolated to zero pressure, where the gas will be ideal in fact.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
.^ Although pressure is defined mechanically, a pressure-measuring device, called a barometer may also be constructed from a sample of an ideal gas held at a constant temperature.- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
^ These results for the difference and the ratio of the specific heats at constant pressure and constant volume are very important and useful.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ When necessary, results have been adjusted to units of mol dm -3 to obtain the numerical value(s) of K c given in these tables.- Thermodynamics of Enzyme-Catalyzed Reactions 10 January 2010 17:12 UTC xpdb.nist.gov [Source type: Academic]
.^ Heat and work may be exchanged with the surroundings and thereby induce changes in energy and volume.- Evolution violates the Second Law of Thermodynamics - Page 2 - Science Forums 11 January 2010 21:25 UTC hypography.com [Source type: FILTERED WITH BAYES]
^ The change of intrinsic energy E along any path is found by subtracting the work pdv from either of the expressions for dH. Since the change of energy is independent of the path, the finite change between any two given states may be found by integration along any convenient path.
^ In working to a first approximation, the small term nc/V may be omitted in the expression for s.
.^ The corresponding expressions for the change of energy or total heat are obtained by adding the term 2as 0 (02-002) to those already given, thus: E - Eo = so (0-00) + 2 aso (02-002), F - Fo=S0(0-00) + zaso ( 02-002 ), where So= so+R. 9.
^ The total heat with which we are actually concerned in the working of a steam engine is the total heat as here defined, and not the total heat as defined by Regnault, which, however, differs from ( E+pv ) only by a quantity which is inappreciable in ordinary practice.
^ F= E+pv, Total heat.
).
.^ The energy is less than that of an ideal gas by the term npc.
^ The reaction cycles down a very long potential energy gradient, controlled by kinetics rather than thermodynamics in the short term.- Evolution myths: Evolution violates the second law of thermodynamics - life - 16 April 2008 - New Scientist 11 January 2010 21:25 UTC www.newscientist.com [Source type: FILTERED WITH BAYES]
^ There is a specific physical energy requirement to lift oil (and gas under less pressure) out of the ground.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
.^ If we imagine that the defect of volume c is due to the formation of molecular aggregates consisting of two or more single molecules, and if the kinetic energy of translation of any one of these aggregates is equal to that of one of the single molecules, it is clear that some energy must be lost in co-aggregating, but that the proportion lost will be different for different types of molecules and also for different types of co-aggregation.
^ The energy must be directed in some way.- Jeff's Lunchbreak: Creation Museum/Creationist Rule of Thumb with the 2nd Law of Thermodynamics 11 January 2010 21:25 UTC www.jefflewis.net [Source type: Original source]
^ By symmetry, it must therefore equal 2/3 of the total kinetic energy, so .
.^ I.e., what matters is kinetic energy per degree of freedom, not kinetic energy per molecule?- Less Wrong: The Second Law of Thermodynamics, and Engines of Cognition 11 January 2010 21:25 UTC lesswrong.com [Source type: Original source]
^ You still have two degrees of freedom, but now you have six variables and four equations.
^ Molecules could briefly extract energy from their surroundings, combining in ways that would otherwise be impossible in practice.- Law of Thermodynamics Faces Repeal - WSJ.com 11 January 2010 21:25 UTC online.wsj.com [Source type: General]
be pc/2 for
co-aggregation,
.^ E, Intrinsic energy per unit mass.
^ An intensive property can be derived from every extensive property by considering the extensive property per unit mass or mole of the substance.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ Density - Density ( ) is defined as mass per unit volume.
.^ I.e., what matters is kinetic energy per degree of freedom, not kinetic energy per molecule?- Less Wrong: The Second Law of Thermodynamics, and Engines of Cognition 11 January 2010 21:25 UTC lesswrong.com [Source type: Original source]
^ If two monatomic molecules, having energy of translation only, equivalent to 3 degrees of freedom, combined to form a diatomic molecule with 5 degrees of freedom, the energy lost would.
^ If two diatomic molecules, having each 5 degrees of freedom, combine to form a molecule with 6 degrees of freedom, we should have n = 2, or the energy lost would be 2pc per unit mass.
.^ But if there were no more to the mechanism of molecular evolution than this, we should still be at a loss to understand how more and more complex molecules cam to establish themselves.- Second Law of Thermodynamics - SkepticWiki 11 January 2010 21:25 UTC www.skepticwiki.org [Source type: Original source]
^ Evolution is more than just a theory, it's a fact.- Evolution Defying Second Law of Thermodynamics [Archive] - TeenSpot.com - Teen Message Boards 11 January 2010 21:25 UTC www.teenspot.com [Source type: Original source]
^ I.e., what matters is kinetic energy per degree of freedom, not kinetic energy per molecule?- Less Wrong: The Second Law of Thermodynamics, and Engines of Cognition 11 January 2010 21:25 UTC lesswrong.com [Source type: Original source]
.^ It is not necessary to suppose that the co-aggregated molecules are permanently associated.
^ V =Re/p due to co- aggregation of the molecules) which varies inversely as the nth power of 0, but is independent of p to a first approximation at moderate pressures.
.^ They are continually changing partners, the ratio c/V representing approximately the ratio of the time during which any one molecule is paired to the time during which it is free.
^ Given this tautology, computer scientists are free to choose one of a number of abstract quantities that are conserved over time to use as the "energy" of a system.- ACM Sigplan Notices 29, 4 (Apr 1994), 58-63. 10 January 2010 17:12 UTC www.pipeline.com [Source type: FILTERED WITH BAYES]
^ During dynamic equilibrium , counter-balancing "reactions that are reversible" occur at the microscopic level of molecules, even though (by the definition of equilibrium) no change is occurring at the macroscopic level.- Second Law: Entropy, Complexity, and Evolution 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
.^ At higher densities it is probable that more complex aggregates would be formed, so that as the effect of the collisions became more important c would cease to be a function of the temperature only; experiment, indeed, shows this to be the case.
^ Away from equilibrium, highly ordered stable complex systems can emerge, develop and grow at the expense of more disorder at higher levels in the system's hierarchy.- Schneider and Kay, 1994 11 January 2010 21:25 UTC www.nesh.ca [Source type: Academic]
^ At high temperatures, entropy becomes more important.- Second Law: Entropy, Complexity, and Evolution 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
13.
Entropy. - . follows from the definition of the
absolute scale of temperature, as given in relations (2), that in
passing at constant temperature 0 from one adiabatic 4' (Fig.
^ Your "definition" of temperature has the following roots.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ In the notes, I adopted the following definition of temperature T: .- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ Here is the definition of the absolute temperature T .- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
.^ I) to any other adiabatic 0", the quotient H/o of the heat absorbed by the temperature at which it is absorbed is the same for the same two adiabatics whatever the temperature of the isothermal path.
^ A cycle such as ABCD enclosed by parts of two isothermals, BC, AD, and two adiabatics, AB, CD, is the simplest form of cycle for theoretical purposes, since all the heat absorbed, H', is taken in during the process represented by one isothermal at the temperature o', and all the heat rejected, H", is given out during the process represented by the other at the temperature 0".
^ Thus, we write dS > then > and recalling that C P = then > and S = dT In other words, the vibrational entropy can be found by integrating the heat capacity divided by temperature.- Thermodynamics Notes 10 January 2010 17:12 UTC www.geol.ucsb.edu [Source type: Academic]
.^ The heat absorbed in this change is called the latent heat of change of state, and may be represented by the symbol L'.
^ This quotient is called the change of entropy, and may be denoted by (4,"-0').
^ If two systems are brought into thermal contact, the entropy of one may decrease, and the entropy of the other increase, but the net entropy change will be zero or positive.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
.^ In passing along an adiabatic there is no change of entropy, since no heat is absorbed.
^ Even if the expansion is adiabatic, in the sense that it takes place inside a non-conducting enclosure and no heat is supplied from external sources, it will not be isentropic, since the heat supplied by internal friction must be included in reckoning the change of entropy.
^ Since only changes in entropy are defined, it was thought that there was an additive constant which would always be arbitrary.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
.^ Recall entropy depends only on the the state of the gas.- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
^ An isentropic process (reversible adiabatic process) occurs at a constant entropy.- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
^ So the initial state of the gas is , and the final state of the gas is .- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
.^ The increase in entropy is given by the integral of δ Q / T for any reversible process between these two states.- Second Law of Thermodynamics - SkepticWiki 11 January 2010 21:25 UTC www.skepticwiki.org [Source type: Original source]
^ The change of intrinsic energy E along any path is found by subtracting the work pdv from either of the expressions for dH. Since the change of energy is independent of the path, the finite change between any two given states may be found by integration along any convenient path.
^ The expression for the change of entropy between any two states is found by dividing either of the expressions for dH in (8) by 0 and integrating between the given limits, since dH/B is a perfect differential.
.^ This added heat changed the temperature of the band.
^ When we heat ice, it changes from a solid phase to a liquid phase to a gaseous phase.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ For solids and liquids, we see that the difference in the specific heats is small, and γ is about 1.0.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
In the case of an ideal gas,
dp/d9 at constant volume =R/v, and
dvld6 at
constant pressure =R/p; thus we obtain the expressions for the
change of entropy 0-4)0 from the state poeovo to the state
pev, log e e/eo+R logev/vo =S log e 9/00-R (32) In the
case of an imperfect gas or vapour, the above expressions are
frequently employed, but a more accurate result may be obtained by
employing equation (17) with the value of the specific heat,
S, from (29), which gives the expression 4-¢o = Sologe0/00
- R logep/po-n(cp/B-copo/Bo)
.^ The state of a substance may be defined by means of the temperature and entropy as co-ordinates, instead of employing the pressure and volume as in the indicator diagram.
^ Typically, a system the entropy of which we wish to know has been defined in terms of common macroscopic thermodynamic properties that we have at our disposal and with which the reader may already be familiar such as volume, pressure, temperature, and internal energy for which we have not given formal definitions.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ Realize that when we write dG = VdP - SdT we are implicitly writing dG = dP - dT which means that = V and = -S These relations indicate that the change in Gibbs free energy with respect to pressure is the molar volume V and the change in Gibbs free energy with respect to temperature is minus the entropy S. Gibbs Free Energy of Formation .- Thermodynamics Notes 10 January 2010 17:12 UTC www.geol.ucsb.edu [Source type: Academic]
.^ This method of representation is applicable to certain kinds of problems, and has been developed by Macfarlane Gray and other writers in its application to the steam engine.
^ From here, a semblance of a thermo-science began to develop with the construction of the first successful atmospheric steam engines in England by Thomas Savery in 1697 and Thomas Newcomen in 1712.- Thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 10 January 2010 17:12 UTC www.chemie.de [Source type: Academic]
^ Readers will find clear and concise presentations, sound developments of the fundamentals, and state-of-the-art engineering applications.- Powell's Books - Fundamentals of Engineering Thermodynamics (6TH 08 Edition) by Michael J. Moran 11 January 2010 21:25 UTC www.powells.com [Source type: Academic]
.^ (See Steam Engine .
^ This next toy is an example of the simplest steam engine you will ever see.- Chapter 5: Thermodynamics -- Building simple heat engines 10 January 2010 17:12 UTC sci-toys.com [Source type: FILTERED WITH BAYES]
)
.^ Areas on the temperature-entropy or 0, 4, diagram represent quantities of heat in the same way as areas on the indicator diagram represent quantities of work.
^ In the early 19th century, it slowly became evident that heat was not a conserved quantity, as it should have been if it were material, but that work and heat were interconvertible.- Thermodynamics 11 January 2010 21:25 UTC mysite.du.edu [Source type: Academic]
^ The area of the cycle, viz., that enclosed by the path Bcda , represents the balance of external work done by the substance in one cycle, and is positive if the cycle is described clockwise 0' O as indicated by the arrows.
.^ The "reversibility" restriction on the heat in the definition of entropy is necessary if entropy is to be a state function.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ What does work in a cycle correspond to on a P-V diagram?- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
^ For any system, entropy is a physically measurable quantity.- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
.^ Changes of entropy must be calculated in terms of quantities of heat, and must be interpreted in a similar manner.
^ The second term is the change in the entropy of the system.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
^ Even if the expansion is adiabatic, in the sense that it takes place inside a non-conducting enclosure and no heat is supplied from external sources, it will not be isentropic, since the heat supplied by internal friction must be included in reckoning the change of entropy.
The majority of
thermodynamical problems may be treated without any reference to
entropy, but it affords a convenient method of expression in
abstract thermodynamics, especially in the consideration of
irreversible processes and in reference to the conditions of
equilibrium of heterogeneous systems.
14.
Irreversible Processes. - . order that a process
may be strictly reversible, it is necessary that the state of the
working substance should be one of equilibrium at uniform pressure
and temperature throughout.
^ D S univ > 0 for a spontaneous process D S univ = 0 for a reversible process (a process in equilibrium).- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ In order that a process may be strictly reversible, it is necessary that the state of the working substance should be one of equilibrium at uniform pressure and temperature throughout.
^ A reversible process is one in which the system and surroundings are in equilibrium throughout the process .- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ If heat passes " of itself " from a higher to a lower temperature by conduction, convection or radiation, the transfer cannot be reversed without an expenditure of work.
^ Heat cannot spontaneously flow from a material at lower temperature to a material at higher temperature.- Second law of thermodynamics: Encyclopedia of chemistry, analytics & pharmaceutics with 64,557 entries. 11 January 2010 21:25 UTC www.chemie.de [Source type: FILTERED WITH BAYES]
^ Actually, it can be transferred by three methods: conduction, convection, and radiation.
.^ In essence, it is a device which converts heat energy into mechanical work, like moving pistons, levers and so on.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
^ If mechanical work or kinetic energy is directly converted into heat by friction, reversal of the motion does not restore the energy so converted.
^ This combined kinetic energy then gets converted into gravitational potential energy.
.^ There is never a net increase in potential energy, nor is there a net decrease in entropy.- Evolution violates the Second Law of Thermodynamics - Science Forums 10 January 2010 17:12 UTC hypography.com [Source type: FILTERED WITH BAYES]
^ In all such cases there is necessarily, by Carnot's principle, a loss of efficiency or available energy, accompanied by an increase of entropy, which serves as a convenient measure or criterion of the loss.
^ Entropy is a measure of order and energy in a system.- The Second Law of Thermodynamics 10 January 2010 17:12 UTC www.irfi.org [Source type: FILTERED WITH BAYES]
.^ A common illustration of an irreversible process is the expansion of a gas into a vacuum or against a pressure less than its own.
^ To illustrate how to calculate the change in entropy in an irreversible process, consider the irreversible free expansion of an ideal gas from an initial volume into a vacuum such that its final volume is .- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
^ Similarly, the heat transferred to the system is a maximum in the reversible process, and is less than this maximum for any irreversible process.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ In this case the work of expansion, pdv, is expended in the first instance in producing kinetic energy of motion of parts of the gas.
^ In this case, the S e term represents the negative entropy, or organizing work done on the system as a result of both energy and mass flow through the system.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
^ Thus, the efficiency in terms of the work produced relative to the high-temperature energy absorbed is ( TH - TL )/ TH = ( deltaT )/ TH .- ACM Sigplan Notices 29, 4 (Apr 1994), 58-63. 10 January 2010 17:12 UTC www.pipeline.com [Source type: FILTERED WITH BAYES]
.^ If mechanical work or kinetic energy is directly converted into heat by friction, reversal of the motion does not restore the energy so converted.
^ So the initial state of the gas is , and the final state of the gas is .- Entropy 11 January 2010 21:25 UTC srikant.org [Source type: FILTERED WITH BAYES]
^ Then the heat energy is converted into mechanical energy that can be used to do work.- The Second Law of Thermodynamics 10 January 2010 17:12 UTC www.irfi.org [Source type: FILTERED WITH BAYES]
.^ The entropy change for the universe in this expansion is .- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ Even if the expansion is adiabatic, in the sense that it takes place inside a non-conducting enclosure and no heat is supplied from external sources, it will not be isentropic, since the heat supplied by internal friction must be included in reckoning the change of entropy.
^ The change in entropy on expansion is therefore .- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ Specifically, the first law addresses the interconvertability of work and heat as forms of energy.
^ The first law is the law of conservation of energy.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ Internal energy = heat + work .
.^ The final condition is thermal equilibrium.- Overcoming Bias : Scandalous Heat 10 January 2010 17:12 UTC www.overcomingbias.com [Source type: Original source]
^ The final state of the substance, when equilibrium has been restored, may be deduced from this condition, if the energy can be expressed in terms of the co-ordinates.
^ We can readily see the difficulty in getting polymerization reactions to occur under equilibrium conditions, i.e., in the absence of such an energy flow.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
- Thermodynamics and the Origin of Life 11 January 2010 21:25 UTC www.ldolphin.org [Source type: Academic]
.^ The lines of constant energy on the diagram are called Isenergics.
^ But the line of constant energy on - the diagram does not represent the path of the transformation, unless it be supposed to be effected in a series of infinitesimal steps between each of which the substance is restored to an equilibrium state.
^ In the limiting case of a long fine tube, the bore of which varies in such a manner that U is constant, the state of the substance along a line of flow may be represented by the line of constant total heat, d(E+pv) = o; but in the case of a porous plug or small throttling aperture , the steps of the process cannot be followed, though the final state is the same.
.^ An irreversible process which permits a more complete experimental investigation is the steady flow of a fluid in a tube already referred to in section to.
^ The numerous quantitative relations derived from this law have been subjected to more and more accurate experimental investigation without the detection of the slightest inaccuracy."—* G.N. Lewis and *M. Randall, Thermodynamics (1961), p.
^ Prigogine has developed a more general formulation of the laws of thermodynamics which includes nonlinear, irreversible processes such as autocatalytic activity.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ There is initially no variation.- Discussion with a Creationist aboutthe Second Law of Thermodynamics 11 January 2010 21:25 UTC www.fred.net [Source type: Original source]
^ If the tube is a perfect non-conductor, and if there are no eddies or frictional dissipation, the state of the substance at any point of the tube as to E, p, and v, is represented by the adiabatic or isentropic path, dE= -pdv.
^ U, Kinetic energy of flow of fluid.
.^ But the entropy of a system does not always increase.- Second Law: Entropy, Complexity, and Evolution 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
^ But in this reaction, and in those below, there is always an entropy increase for the universe.- Second Law: Entropy, Complexity, and Evolution 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
^ In practice, however, there is always some frictional dissipation, accompanied by an increase of entropy and by a fall of pressure.
.^ For such a process the change in any state function is 0.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ If we make they contact with a large system, this may destroy the states of the real systems and make them have the same temperature of the large system itself.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ In this case, the S e term represents the negative entropy, or organizing work done on the system as a result of both energy and mass flow through the system.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ One of the processes by which entropy is increased is life.- 'Evolution as Described by the Second Law of Thermodynamics' by PhysoOrg - RichardDawkins.net 11 January 2010 21:25 UTC richarddawkins.net [Source type: FILTERED WITH BAYES]
^ Reversible and irreversible process .- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
^ Similarly, the heat transferred to the system is a maximum in the reversible process, and is less than this maximum for any irreversible process.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ This affords a useful criterion (see Energetics ) between transformations which are impossible and those which are possible but irreversible.
^ Second, it is impossible entirely to convert heat into work—something is always lost in energetic transformation.- IoHT :: 110+ Variations of the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.humanthermodynamics.com [Source type: Academic]
^ We can also see now that the efficiency of heat engines will increase if we make the temperature difference between the heat source and heat sink as large as possible.- The Oil Drum | Why We "Waste" Energy: The Second Law of Thermodynamics Explains--UPDATED 8/7 11 January 2010 21:25 UTC www.theoildrum.com [Source type: FILTERED WITH BAYES]
.^ In any spontaneous irreversible change, if the system is heat-isolated, there must be an increase of entropy.
^ In real processes, the change in total entropy is always positive.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ In any small reversible change in which the substance absorbs heat, dH, from external sources, the increase of entropy, d0, must be equal to dH/9.
.^ The entropy cannot diminish.
.^ Any change involving decrease of entropy is impossible.
^ For the first type of entropy change, a useful principle (but not the only principle) is to think about constraint change because when there is more constraint and thus less freedom of motion , entropy decreases.- Second Law: Entropy, Complexity, and Evolution 11 January 2010 21:25 UTC www.asa3.org [Source type: FILTERED WITH BAYES]
^ The heat involved in this process cannot be used in equation 11-4 to calculate the entropy change of the expansion.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ The entropy tends to a maximum, and the state is one of stable equilibrium when the value of the entropy is the maximum value consistent with the conditions of the problem.
^ Equilibrium is reached when entropy reaches its maximum value, and this means that the system is in its most likely state.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
^ The entropy of the world tends towards a maximum.- IoHT :: 110+ Variations of the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.humanthermodynamics.com [Source type: Academic]
15.
Heterogeneous Equilibrium. - . as
distinguished from a homogeneous substance, consisting of two or
more states or phases, a similar condition of equilibrium applies.
^ In a system, as distinguished from a homogeneous substance, consisting of two or more states or phases, a similar condition of equilibrium applies.
^ Also, the equation applies to non-equilibrium conditions.- Discussion with a Creationist aboutthe Second Law of Thermodynamics 11 January 2010 21:25 UTC www.fred.net [Source type: Original source]
^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
.^ Entropy for an isolated system can never spontaneously decrease.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
^ We have seen that the entropy of an isolated system increases.- Approaching the world’s environmental problems through the Second Law (Entropy Law) of Thermodynamics - Encyclopedia of Earth 11 January 2010 21:25 UTC www.eoearth.org [Source type: FILTERED WITH BAYES]
^ In any spontaneous irreversible change, if the system is heat-isolated, there must be an increase of entropy.
.^ Starting with unit mass of the substance in the first state (e.g.
^ The total entropy of the system is found by multiplying the entropy per unit mass of the substance in each state by the mass existing in that state, and adding the products so obtained.
^ E, Intrinsic energy per unit mass.
.^ This is the point where we have equilibrium between liquid and vapor.- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
^ The simplest case to consider is that of equilibrium between solid and liquid, or liquid and vapour.
^ But let's not bother with that...more importantly it is the case that entropy of the water which forms the snowflafe is reduced with every phase change...when it goes from gas to liquid, and when it goes from liquid to solid.- Does Evolutionary Theory Violate the Laws of Thermodynamics? - Debate Nation 11 January 2010 21:25 UTC www.debatenation.com [Source type: General]
.^ The more general case is discussed in the article Energetics , and in the original memoirs of Willard Gibbs and others.
^ First, consider the configurational case, and Brian Greene’s explanation for why molecules (or other material things in general) disperse in space.- On the Relation between Thermodynamic and Configurational Entropy, and the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.foundalis.com [Source type: Original source]
^ In other words, general advice will usually not be considered legal advice absent more specific facts.- Patent Law Blog (Patently-O): CAFC Rejects Patent on Invention to Overcome the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.patentlyo.com [Source type: FILTERED WITH BAYES]
.^ Since the condition of heat-isolation is impracticable, the condition of maximum entropy cannot, as a rule, be directly applied, and it is necessary to find a more convenient method of expression.
^ It is not necessary to suppose that c varies inversely as the nth power of the temperature, and that b is constant, as assumed in deducing the expressions for cp, E, and F. Although the value of G in any case cannot be found without that of 0, and although the consideration of the properties of the thermodynamic potential cannot in any case lead to results which are not directly deducible from the two fundamental laws, it affords a convenient method of formal expression in abstract thermodynamics for the condition of equilibrium between different phases, or the criterion of the possibility of a transformation.
^ Although we cannot prove it here, the entropy increase of a substance due to heat q at temperature T is given by Δ S = .- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
.^ Heat cannot be completely transformed into work.- ECONOMY AND THERMODYNAMICS 10 January 2010 17:12 UTC www.ecen.com [Source type: FILTERED WITH BAYES]
^ Similarly, the heat transferred to the system is a maximum in the reversible process, and is less than this maximum for any irreversible process.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ Laws are expected to apply generally.- Jeff's Lunchbreak: Creation Museum/Creationist Rule of Thumb with the 2nd Law of Thermodynamics 11 January 2010 21:25 UTC www.jefflewis.net [Source type: Original source]
.^ In the special case, however, in which the transformation is conducted in an isothermal enclosure, a common condition easily realized in practice, the temperature at the end of the transformation is reduced to its initial value throughout the substance.
^ If J', J" represent the values of the function for unit mass of the substance of specific volumes v' and v" in the two states at temperature 0 and pressure and if a mass m is in the state v', and 1-m in the.
^ Under certain conditions, however, heat conduction may occur by a heat-convection current---the coordinated movement of many gas molecules.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ The value of Od4 is then the same as d(64 ), which is a perfect differential, so that the condition may be written d(46-E) =dW. The condition in this form can be readily applied provided that the external work dW can be measured.
^ If dW is the external work done, dH the heat absorbed from external sources, and dE the increase of intrinsic energy, we have in all cases by the first law, dH-dE=dW. Since Od4 cannot be less than dH, the difference ( 61d4-dE ) cannot be less than dW. This inequality holds in all cases, but cannot in general be applied to an irreversible change, because Od4 is not a perfect differential, and cannot be evaluated without a knowledge of the path or process of transformation.
^ This test was applied by Joule in the well-known experiment in which he allowed a gas to expand from one vessel to another in a calorimeter without doing external work.
There
are two. special cases of importance: -
.^ The condition of stable equilibrium of a system at constant temperature and volume is that the total J should be a minimum.
^ The value of the specific heat s at constant volume can also be measured in a few cases, but it is generally necessary to deduce it from that at constant pressure, by means of relation (6).
^ Although we cannot prove it here, the entropy increase of a substance due to heat q at temperature T is given by Δ S = .- Equilibrium and the Second Law of Thermodynamics 11 January 2010 21:25 UTC cnx.org [Source type: Academic]
.^ Stable " describes a system or phase in its lowest energy state.- Thermodynamics Notes 10 January 2010 17:12 UTC www.geol.ucsb.edu [Source type: Academic]
^ The product pv for any state such as D in fig.
^ Metastable " describes a system or phase in any other energy state.- Thermodynamics Notes 10 January 2010 17:12 UTC www.geol.ucsb.edu [Source type: Academic]
.^ I by the whole area B"DZ'VO under the isothermal 9"D and the adiabatic DZ', bounded by the axes of pressure and volume.
^ Topics: Surroundings, boundary, closed system, control volume, property, state, process, thermodynamic cycle, extensive property, intensive property, phase, pure substance, equilibrium, specific volume, pressure, temperature, adiabatic process, isothermal process, temperature scales.- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
^ Since dH = CpdT, the area under the curve is the integral of the differential equation and D H = Cp D T (constant pressure).- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ The intrinsic energy, E, is similarly represented by the area DZ'Vd under the adiabatic to the right of the isometric Dd.
^ If the substance in any state such as B were allowed to expand adiabatically ( dH = o ) down to the absolute zero, at which point it contains no heat and exerts no pressure, the whole of its available heat energy might theoretically be recovered in the form of external work, represented on the diagram by the whole area BAZcb under the adiabatic through the state-point B, bounded by the isometric Bb and the zero isopiestic bV. The change of the intrinsic energy in passing from one state to another, as from B to C is represented by the addition of the heat-area H= Bczz ', and the subtraction of the work-area W = BCcb.
^ The difference 90-E is represented by the area 9"DdO to the left of the isometric Dd under the isothermal B"D. The increment of this area (or the decrement of the negative area E--04 ) at constant temperature represents the external work obtainable from the substance in isothermal expansion, in the same way that the decrement of the intrinsic energy represents the work done in adiabatic expansion.
.^ Areas on the temperature-entropy or 0, 4, diagram represent quantities of heat in the same way as areas on the indicator diagram represent quantities of work.
^ These functions do not, however, represent energy existing in the substance, like the intrinsic energy; but the increment of 90 represents heat supplied to, and the decrement of ( E-04 ) represents work obtainable from, the substance when the temperature is kept constant.
^ Constant pressure expansion/compression work.- Thermodynamics 10 January 2010 17:12 UTC www.mae.wvu.edu [Source type: Academic]
.^ Helmholtz himself suggested that this be divided up (Bailyn 1994) between free energy, which today is more specifically renamed helmholtz energy, and bound energy.- Second law Analysis of Gas Turbines...Ben Wiens...innovation consultant...innovating through synergy...value innovation, simple, combined, heat, exchange, recuperated, fuel, cell, solid, oxide, engine, energy, thermodynamics, formulas, efficiency, combustion, conversion, enthalpy, entropy, exergy, availability, cogeneration, recuperation, chemical, looping, westinghouse, rolls, royce, solar, saturn, siemens, ge, steam, temperature, carnot, computer 11 January 2010 21:25 UTC www.benwiens.com [Source type: Academic]
^ Chemists have established rankings of the free energy content of substances so that the amount of energy available can be determined by calculating the differences in the reference values of the materials that react and the materials that are produced.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ Here G o is the standard free energy of the substance at the standard condition of 1.0 bar; G is the free energy at arbitrary pressure P; and the other terms are familiar.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ The boiler contains some substance which is kept at a high temperature by supplying it with energy obtained by converting other (chemical) forms of energy into heat energy - either by burning wood, or fossil fuels and so on.- Second Law of Thermodynamics 11 January 2010 21:25 UTC srikant.org [Source type: Original source]
^ Thus, the efficiency in terms of the work produced relative to the high-temperature energy absorbed is ( TH - TL )/ TH = ( deltaT )/ TH .- ACM Sigplan Notices 29, 4 (Apr 1994), 58-63. 10 January 2010 17:12 UTC www.pipeline.com [Source type: FILTERED WITH BAYES]
^ Phase transitions like the melting of ice are special kinds of work and indicate the cooperative change in potential energy of a system.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ The condition of stable equilibrium of a system at constant temperature and volume is that the total J should be a minimum.
^ The condition of stable equilibrium is that G should be a minimum, for which reason it has been called the " thermodynamic potential at constant pressure."
^ Such systems, treated typically using microcanonical ensembles, are fully described by physical quantities such as the total (and conserved) energy, the volume, etc., with no specification of the temperature.- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
.^ The condition of stable equilibrium of a system at constant temperature and volume is that the total J should be a minimum.
^ The condition of stable equilibrium is that G should be a minimum, for which reason it has been called the " thermodynamic potential at constant pressure."
^ This function is also called the " thermodynamic potential at constant volume " from the analogy with the condition of minimum potential energy as the criterion of stable equilibrium in statics .
.^ As an example, we may apply this condition to the case of change of state.
^ As the section of the tube varies, the change of kinetic energy of flow, dU, is represented by The flow in this case is reversible, and the state of the fluid is the same at points where the section of the tube is the same.
^ These energy states at the atomic level change in predictable ways when heating up an aqueous solution, for example.- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
.^ The volume of 1 kg of neon gas as a function of temperature (at standard pressure).
^ It is obviously a function of two states, namely state A and state B .- Thermodynamics and Differential Forms 10 January 2010 17:12 UTC www.av8n.com [Source type: Academic]
^ Starting with unit mass of the substance in the first state (e.g.
state
.^ J for unit mass of the mixture is mJ' + (1m ) This must be a minimum in the state of equilibrium at constant temperature.
^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
^ The entropy tends to a maximum, and the state is one of stable equilibrium when the value of the entropy is the maximum value consistent with the conditions of the problem.
.^ This function is also called the " thermodynamic potential at constant volume " from the analogy with the condition of minimum potential energy as the criterion of stable equilibrium in statics .
^ The condition of stable equilibrium of a system at constant temperature and volume is that the total J should be a minimum.
^ Since such splits and merges violate micro-reversibility, the volume must therefore remain constant.- ACM Sigplan Notices 29, 4 (Apr 1994), 58-63. 10 January 2010 17:12 UTC www.pipeline.com [Source type: FILTERED WITH BAYES]
.^ The most instructive example of the application of relations (I) and (2) is afforded by the change of state of a substance at constant temperature and pressure.
^ Heat is being sucked in from the hot reservoir, and since the working gas is always in thermal equilibrium with the hot reservoir, its temperature is constant.
^ Since the thermal energy of an ideal gas depends only on its temperature, there is no change in the thermal energy of the gas during this constant-temperature process.
.^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
^ This may be interpreted as the equation of the border curve giving the relation between p and 0, but is more easily obtained by considering the equilibrium at constant pressure instead of constant volume.
^ Also, the equation applies to non-equilibrium conditions.- Discussion with a Creationist aboutthe Second Law of Thermodynamics 11 January 2010 21:25 UTC www.fred.net [Source type: Original source]
.^ The second case, which is of greater practical utility, is that in which the external pressure, p, is kept constant.
^ The value of the specific heat s at constant volume can also be measured in a few cases, but it is generally necessary to deduce it from that at constant pressure, by means of relation (6).
^ The value of the specific heat S at constant pressure can always be determined by experiment, and in practice is one of the most important thermodynamical properties of a substance.
.^ B is the initial state A is the final state.- Thermodynamics and Differential Forms 10 January 2010 17:12 UTC www.av8n.com [Source type: Academic]
^ Since the initial and final states are the same by both paths, D E rev = D E irrev (E is a state function).- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ Figure 9-5 shows the initial and final states of an adiabatic expansion.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
.^ Of note here is that creationist do NOT state that increasing order is impossible; such statements are straw-man arguments in order to make it less reasonable than it really is.- Evolution Defying Second Law of Thermodynamics [Archive] - TeenSpot.com - Teen Message Boards 11 January 2010 21:25 UTC www.teenspot.com [Source type: Original source]
^ Which is not to say I don't expect to see a fair bit of hardship from dramatically increased energy prices and possible shortages, but I don't see why in the long run it cannot be for the better.- The Oil Drum | Why We "Waste" Energy: The Second Law of Thermodynamics Explains--UPDATED 8/7 11 January 2010 21:25 UTC www.theoildrum.com [Source type: FILTERED WITH BAYES]
^ We have seen that for reversible processes, the increase in entropy is always less than for irreversible processes.- Approaching the world’s environmental problems through the Second Law (Entropy Law) of Thermodynamics - Encyclopedia of Earth 11 January 2010 21:25 UTC www.eoearth.org [Source type: FILTERED WITH BAYES]
.^ The condition of stable equilibrium of a system at constant temperature and volume is that the total J should be a minimum.
^ This function is also called the " thermodynamic potential at constant volume " from the analogy with the condition of minimum potential energy as the criterion of stable equilibrium in statics .
^ The condition of stable equilibrium is that G should be a minimum, for which reason it has been called the " thermodynamic potential at constant pressure."
.^ The product pv for any state such as D in fig.
^ This function may be represented, for each state or phase of the system considered, by an area on the indicator diagram similar to that representing the intrinsic energy, E. The product 94, may be represented at any point such as D in Fig.
r is represented by the rectangle
.^ MDdO, bounded by the isopiestic and the isometric through D. The function G is represented by the negative area D"DM under the isothermal, bounded by the isopiestic DM and the axis of pressure.
^ If the substance in any state such as B were allowed to expand adiabatically ( dH = o ) down to the absolute zero, at which point it contains no heat and exerts no pressure, the whole of its available heat energy might theoretically be recovered in the form of external work, represented on the diagram by the whole area BAZcb under the adiabatic through the state-point B, bounded by the isometric Bb and the zero isopiestic bV. The change of the intrinsic energy in passing from one state to another, as from B to C is represented by the addition of the heat-area H= Bczz ', and the subtraction of the work-area W = BCcb.
^ In this case, the S e term represents the negative entropy, or organizing work done on the system as a result of both energy and mass flow through the system.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ S, Specific heat of gas at constant pressure.
^ In this case the condition of flow is simply that of constant total heat, or in symbols, d(E+pv) =0.
^ (I I) This expression shows that the rate of variation of the total heat with temperature at constant pressure is equal to the specific heat at constant pressure.
.^ This is our first constraint on the form of the function, f.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ This is geometrically obvious from the form of the area representing the function on the indicator diagram, and also follows directly from the first law.
^ The area of the cycle, viz., that enclosed by the path Bcda , represents the balance of external work done by the substance in one cycle, and is positive if the cycle is described clockwise 0' O as indicated by the arrows.
.^ The simplest application of the thermodynamic potential is to questions of change of state.
^ And the question about the application of thermodynamics to the Universe as a whole is more than a bit irrelevant to the human condition on Earth.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ The most instructive example of the application of relations (I) and (2) is afforded by the change of state of a substance at constant temperature and pressure.
.^ This test was applied by Joule in the well-known experiment in which he allowed a gas to expand from one vessel to another in a calorimeter without doing external work.
^ Another statement of the 2nd law is that, for any isolated system, the entropy remains the same during any reversible process and increases during any irreversible process.- The Second Law of Thermodynamics 11 January 2010 21:25 UTC www.tektonics.org [Source type: Original source]
^ The inverse temperature is proportional to the change in entropy which results from the addition of one quantum of energy .- ACM Sigplan Notices 29, 4 (Apr 1994), 58-63. 10 January 2010 17:12 UTC www.pipeline.com [Source type: FILTERED WITH BAYES]
.^ We may take equation (17) as a practical example of the thermodynamical principles already given.
^ As an example of one of the few cases where a complete solution is possible, we may take the comparatively simple case equation (17), already considered, which is approximately true for the majority of vapours at moderate pressures.
^ Lesser inventors, e.g., less dedicated or determined, tend to give up prematurely for one reason or another, and thus a possible solution may be missed, and potential progress impeded for who knows how long.- Patent Law Blog (Patently-O): CAFC Rejects Patent on Invention to Overcome the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.patentlyo.com [Source type: FILTERED WITH BAYES]
.^ In the case of a solid or a liquid, the latent heat of isothermal expansion may often be neglected, and if the specific heat, s, be also taken as constant, we have simply 0-00 =s log e0/00.
^ Entropy is an extensive state function that accounts for the effects of irreversibility in thermodynamic systems.- Jeff's Lunchbreak: Creation Museum/Creationist Rule of Thumb with the 2nd Law of Thermodynamics 11 January 2010 21:25 UTC www.jefflewis.net [Source type: Original source]
^ Evolution as Described by the Second Law of Thermodynamics By viewing evolution as the motion of energy flows toward a stationary state (entropy), evolution can be explained by the second law of thermodynamics, a law which conventionally describes physical systems.- 'Evolution as Described by the Second Law of Thermodynamics' by PhysoOrg - RichardDawkins.net 11 January 2010 21:25 UTC richarddawkins.net [Source type: FILTERED WITH BAYES]
.^ F" =S 0 0 - (n+1)cp+bp+B„ dG"/dO (p const) =0" = dJ"/dB (v const)..
.^ The properties define the state of the substance even though not all of them are independent.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ And all the properties of the substance may be expressed in terms of G or J and their partial differential coefficients.
^ Assuming the function G to be expressed in terms of p and 0, this condition represents the relation between p and 0 corresponding to equilibrium between the two states, which is the solution of the relation ( v" - v')dp/dO=L/D, (5).
.^ Specific heat of gas at constant volume.
^ S, Specific heat of gas at constant pressure.
^ (I I) This expression shows that the rate of variation of the total heat with temperature at constant pressure is equal to the specific heat at constant pressure.
.^ To find the border curve of equilibrium between the two states, giving the saturation pressure as a function of the temperature, we have merely to equate the values of G and G".
^ Units (Temperature; Pressure; Denstiy; Energy; Velocity; Viscosity; Surface Tension); Type of Data (Isothermal Properties; Isobaric Properties; Isochoric Properties; Saturation Properties)..."- Martindale's Calculators On-Line Center: Chemistry Center: R-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Animations, etc. 10 January 2010 17:12 UTC www.martindalecenter.com [Source type: Academic]
^ The advantage is that cycle calculations can be done easily on a computer using simple equations.- Second law Analysis of Gas Turbines...Ben Wiens...innovation consultant...innovating through synergy...value innovation, simple, combined, heat, exchange, recuperated, fuel, cell, solid, oxide, engine, energy, thermodynamics, formulas, efficiency, combustion, conversion, enthalpy, entropy, exergy, availability, cogeneration, recuperation, chemical, looping, westinghouse, rolls, royce, solar, saturn, siemens, ge, steam, temperature, carnot, computer 11 January 2010 21:25 UTC www.benwiens.com [Source type: Academic]
.^ The value of A is determined by observing the value of Do at some known pressure po, e.g.
^ The value of the specific heat S at constant pressure can always be determined by experiment, and in practice is one of the most important thermodynamical properties of a substance.
^ It is generally taken as constant, but its value at moderate pressures is difficult to determine.
at the boiling-point. The value of B
is determined by
observing the latent heat, Lo = F"o - F'0, which gives B =B" -
B' =L0+(s' - So)00+(n+r)copo - bpo+dho
(45) This constant may
be called the absolute latent heat, as it expresses the thermal
value of the change of state in a manner independent of
temperature.
.^ It is of the same order as the probable errors of observation, and may be neglected in.
^ Specific heat of gas at constant volume.
^ S, Specific heat of gas at constant pressure.
practice.
.^ The advantage of this type of equation is that c is a function of the temperature only.
^ A complete set of simple formulas for analyzing a gas turbine are provided.- Second law Analysis of Gas Turbines...Ben Wiens...innovation consultant...innovating through synergy...value innovation, simple, combined, heat, exchange, recuperated, fuel, cell, solid, oxide, engine, energy, thermodynamics, formulas, efficiency, combustion, conversion, enthalpy, entropy, exergy, availability, cogeneration, recuperation, chemical, looping, westinghouse, rolls, royce, solar, saturn, siemens, ge, steam, temperature, carnot, computer 11 January 2010 21:25 UTC www.benwiens.com [Source type: Academic]
^ The expression for R logp for an imperfect gas of this type differs from that for a perfect gas only by the addition of the term ( c - b) p/D. This simple result is generally true, and the corresponding expressions for G" and J" are valid, provided that c - b in formula (17) is a function of the temperature only.
.^ The laws of thermodynamics, by and large, cannot be changed.- FARK.com: (4742207) In this economy, we obey the laws of thermodynamics 11 January 2010 21:25 UTC www.fark.com [Source type: Original source]
^ Thermodynamics is based chiefly on two laws.- The Second Law of Thermodynamics 10 January 2010 17:12 UTC www.irfi.org [Source type: FILTERED WITH BAYES]
^ It is not necessary to suppose that c varies inversely as the nth power of the temperature, and that b is constant, as assumed in deducing the expressions for cp, E, and F. Although the value of G in any case cannot be found without that of 0, and although the consideration of the properties of the thermodynamic potential cannot in any case lead to results which are not directly deducible from the two fundamental laws, it affords a convenient method of formal expression in abstract thermodynamics for the condition of equilibrium between different phases, or the criterion of the possibility of a transformation.
.^ For such purely abstract purposes, the possibility of numerical evaluation of the function is of secondary importance, and it is often possible to make qualitative deductions with regard to the general nature of a transformation without any knowledge of the actual form of the function.
^ That heat can then be put to a useful purpose, such as to power a car, and in doing that we transform (part of ) the heat into work.- Approaching the world’s environmental problems through the Second Law (Entropy Law) of Thermodynamics - Encyclopedia of Earth 11 January 2010 21:25 UTC www.eoearth.org [Source type: FILTERED WITH BAYES]
^ I actually still find it hard to believe that such an 'ignorance' on your part really exists, and wonder whether it is not feigned, for purposes thus far unknown to me.- Discussion with a Creationist aboutthe Second Law of Thermodynamics 11 January 2010 21:25 UTC www.fred.net [Source type: Original source]
.^ A more common method of procedure, however, is to infer the general relations of the thermodynamic potential from a consideration of the phenomena of equilibrium.
^ The most important and most useful of the relations between the thermodynamical properties of a substance may be very simply deduced from a consideration of the indicator diagram by a geometrical method, which is in many respects more instructive than the analytical method generally employed.
^ Prigogine has developed a more general formulation of the laws of thermodynamics which includes nonlinear, irreversible processes such as autocatalytic activity.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ As it would be impossible within the limits of this article to illustrate or explain adequately the applications which have been made of the principles of thermodynamics, it has been necessary to select such illustrations only as are required for other reasons, or could not be found elsewhere.
^ A more complete and more elaborate treatment of the subject will be found in foreign treatises, such as those of Clausius, Zeuner, Duhem, Bertrand, Planck and others.
^ The object of the present article is to illustrate the practical application of the two general principles - (I) Joule's law of the equivalence of heat and work, and (2) Carnot's principle, that the efficiency of a reversible engine depends only on the temperatures between which it works; these principles are commonly known as the first and second laws of thermodynamics.
.^ For fuller details and explanations of the elements of the subject, the reader must be referred to general treatises such as Baynes's Thermodynamics (Oxford), Tait's Thermodynamics (Edinburgh), Maxwell's Theory of Heat (London), Parker's Thermodynamics (Cambridge), Clausius's Mechanical Theory of Heat (translated by Browne, London ), and Preston's Theory of Heat (London).
^ I. The name thermodynamics is given to that branch of the general science of Energetics which deals with the relations between thermal and mechanical energy, and the transformations of heat into work, and vice versa.
^ A more complete and more elaborate treatment of the subject will be found in foreign treatises, such as those of Clausius, Zeuner, Duhem, Bertrand, Planck and others.
.^ One or two chapters on the subject are also generally included in treatises on the steam engine, or other heat engines, such as those of Rankine, Perry or Ewing.
^ For fuller details and explanations of the elements of the subject, the reader must be referred to general treatises such as Baynes's Thermodynamics (Oxford), Tait's Thermodynamics (Edinburgh), Maxwell's Theory of Heat (London), Parker's Thermodynamics (Cambridge), Clausius's Mechanical Theory of Heat (translated by Browne, London ), and Preston's Theory of Heat (London).
^ A more complete and more elaborate treatment of the subject will be found in foreign treatises, such as those of Clausius, Zeuner, Duhem, Bertrand, Planck and others.
.^ Of greater interest, particularly from a historical point of view, are the original papers of Joule, Thomson and Rankine, some of which have been reprinted in a collected form.
^ Dear Alper, thanks for pointing out the interesting paper of Wang et al..- thermodynamics of nanoscale small systems | iMechanica 11 January 2010 21:25 UTC www.imechanica.org [Source type: FILTERED WITH BAYES]
^ Throughout Chapters 7-9 we have analyzed the problems of complexity and the origin of life from a thermodynamic point of view.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
.^ A more complete and more elaborate treatment of the subject will be found in foreign treatises, such as those of Clausius, Zeuner, Duhem, Bertrand, Planck and others.
^ But his point is to argue for nuclear generation of hydrogen, and subjects peripheral to his mission, such as oil depletion, get careless treatment.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ Look at the millions of fossils of other creatures that are extant, with more found every day.- Thermodynamics 10 January 2010 17:12 UTC mwillett.org [Source type: Original source]
.^ Alphabetical Index of Symbols Employed.
.^ Thermodynamic or absolute temperature.
^ The thermodynamic entropy S is defined by the relation Δ S = Δ Q / T, where Δ Q is the amount of heat absorbed in a reversible process, and T is the absolute temperature at which the process is occurring.- On the Relation between Thermodynamic and Configurational Entropy, and the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.foundalis.com [Source type: Original source]
^ The third law of thermodynamics (page 318) The entropy of a system approaches zero as its temperature approaches absolute zero.
0, Entropy. Section 13.
b, Covolume of molecules of gas. Equation (17).
.^ V =RD/p, Ideal volume of gas per unit mass.
^ Co-aggregation volume per unit mass.
^ E, Intrinsic energy per unit mass.
Equation
(17).
.^ Base of Napierian logarithms.
.^ An intensive property can be derived from every extensive property by considering the extensive property per unit mass or mole of the substance.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ Oil has a higher energy content per unit weight and burns at a higher temperature than coal; it is easier to transport, and can be used in internal combustion engines.- Human and natural systems oppose the second law of thermodynamics byimporting inputs for replacement and maintenance 11 January 2010 21:25 UTC www.dieoff.org [Source type: Original source]
^ "The total solar energy absorbed by Earth's atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
Section 2.
.^ The total heat with which we are actually concerned in the working of a steam engine is the total heat as here defined, and not the total heat as defined by Regnault, which, however, differs from ( E+pv ) only by a quantity which is inappreciable in ordinary practice.
^ In this case the condition of flow is simply that of constant total heat, or in symbols, d(E+pv) =0.
^ Since dE=dH - pdv, we have evidently for the variation of the total heat from the second expression (8), dF=d(E + pv) =dH+vdp=Sde - (Odv/de - v)dp .
Section 7.
.^ G, J, Thermodynamic potential functions.
^ This function is also called the " thermodynamic potential at constant volume " from the analogy with the condition of minimum potential energy as the criterion of stable equilibrium in statics .
Section
15.
.^ The entropy transport rate associated with heat transfer at a boundary per unit time t with heat-transfer rate q/t and uniform temperature T is defined by the quantity (q/t)/T, and this quantity has the same sign convention as the heat-transfer.- IoHT :: 110+ Variations of the Second Law of Thermodynamics 11 January 2010 21:25 UTC www.humanthermodynamics.com [Source type: Academic]
^ (I) in which E 0 represents the quantity of energy originally present in the body, and all the quantities are supposed, as usual, to be expressed in mechanical units.
^ The units of heat (energy): [J] = [VC] (electrical work) = [Nm] (mechanical work) J = Joule; V = voltage; C = charge; N = Newton; m = meter .- Thermodynamics and solution behavior of macromolecules 10 January 2010 17:12 UTC www.whatislife.com [Source type: Academic]
Section 2.
.^ If we write K for the adiabatic elasticity , and k for the isothermal elasticity, we obtain S/s = ECÆF = K/k.
^ K, k, Adiabatic and isothermal elasticities.
Equation
(7).
.^ L, Latent heat of fusion or vaporization .
Equation (5).
M, Molecular weight. Section 8.
m,
.^ Mass of substance or molecule.
n, Index in expression for c. Equation (17).
p, Pressure of fluid. po, Initial pressure.
R= S
so, Constant in gas-equation (17).
.^ There is a specific physical energy requirement to lift oil (and gas under less pressure) out of the ground.- The Oil Drum: Canada | In this house, we obey the laws of thermodynamics! 11 January 2010 21:25 UTC canada.theoildrum.com [Source type: FILTERED WITH BAYES]
^ When valve 3 is opened, this gas will expand, pushing back the right piston against the constant external pressure of 1 atm, until the gas pressure is 1.00 atm.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
^ Heat always flows spontaneously from a hotter reservoir to a colder reservoir until there is no longer a temperature difference or gradient; gas will always flow from high pressure to low pressure until there is no longer a pressure difference or gradient.- Schneider and Kay, 1994 11 January 2010 21:25 UTC www.nesh.ca [Source type: Academic]
So, Limiting value of S when p=o. Section
12.
.^ S, Specific heat of gas at constant pressure.
^ Specific heat of gas at constant volume.
^ In the case of a solid or a liquid, the latent heat of isothermal expansion may often be neglected, and if the specific heat, s, be also taken as constant, we have simply 0-00 =s log e0/00.
so, Limiting value of s when p=o. Section
12.
.^ The insulation is important because, under these conditions, the heat out term R e will be multiplied by 1 T o /T o = 0 , which would not be the case if heat leaked out the sides at higher temperatures.- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ Expansion or compression under the condition of heat-insulation, represented by curves called Adiabatics, such as BAZ or CDZ', which are necessarily steeper than the isothermals.
^ Under certain conditions, however, heat conduction may occur by a heat-convection current---the coordinated movement of many gas molecules.- Thermodynamics of Living Systems 11 January 2010 21:25 UTC www.evanwiggs.com [Source type: Academic]
Equation
(5).
.^ U, Kinetic energy of flow of fluid.
^ If we consider any short length of the stream bounded by two imaginary cross-sections A and B on either side of the plug, unit mass of the fluid in passing A has work, p'v', done on it by the fluid behind and carries its energy, E'+ U', with it into the space AB, where U' is the kinetic energy of flow.
^ As the section of the tube varies, the change of kinetic energy of flow, dU, is represented by The flow in this case is reversible, and the state of the fluid is the same at points where the section of the tube is the same.
Section To.
it, Mean velocity of gaseous molecules. Section 8.
.^ Show that under conditions of standard pressure and temperature, the volume of a sample of an ideal gas depends only on the number of molecules in it.
^ For the first time we have an interpretation for the temperature based on a microscopic description of matter: in a monoatomic ideal gas, the temperature is a measure of the average kinetic energy per molecule.
^ The number of moles of gas was obtained by applying the ideal gas law to the initial pressure, volume, and temperature conditions.- Appendix F: Some Additional Aspects of Thermodynamics 11 January 2010 21:25 UTC www.wpi.edu [Source type: Academic]
Equation
(17). v,
.^ In the case of a simple compressible substance, one in which surface effects, electromagnetic effects, etc., are unimportant, h = u + Pv, where P is the total pressure of the system and v is the specific volume (the reciprocal of density).- Appendix I 10 January 2010 17:12 UTC dematerialism.net [Source type: FILTERED WITH BAYES]
^ Properties of Water & Steam Properties Calculator OUTPUT values include: "...Enthalpy; Internal Energy; Entropy; Specific Volume; Density; Isobaric Heat Capacity; etc..."- Martindale's Calculators On-Line Center: Mechanical Engineering: S-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Animations, etc. 10 January 2010 17:12 UTC www.martindalecenter.com [Source type: Academic]
- Martindale's Calculators On-Line Center: Chemistry Center: R-Z - Databases, Courses, Textbooks, Lessons, Manuals, Guides, Publications, Technical Reports, Videos, Movies, Calculators, Spreadsheets, Applets, Animations, etc. 10 January 2010 17:12 UTC www.martindalecenter.com [Source type: Academic]
.^ W, External work done by fluid.
(H. L. C.)