THERMODYNAMICS

In science, thermodynamics (from the Greek θέρμη therme, meaning "heat" and δύναμις, dynamis, meaning force) is the study of energy conversion between heat and mechanical work, and subsequently the macroscopic variables such as temperature, volume and pressure. The first to give a concise definition of the subject was Scottish physicist William Thomson who in 1854 stated that:

“Thermo-dynamics is the subject of the relation of heat to forces acting between contiguous parts of bodies, and the relation of heat to electrical agency.”

Two derivatives of thermodynamics to emerge in the decades to follow include: statistical thermodynamics (or statistical mechanics) (1860), a subject concerned with statistical predictions of the collective motion of particles from their microscopic behavior, and chemical thermodynamics (1873), a subject concerned with the nature of the role of entropy in the process of chemical reaction. Historically, thermodynamics developed out of a need to increase the efficiency of early steam engines, particularly through the work of French physicist Nicolas Léonard Sadi Carnot (1824) who believed that engine efficiency was the key that could help France win the Napoleonic Wars.

History of thermodynamics
Laws of thermodynamics

Thermodynamic:

• Boundary
  Boundary (thermodynamic)
  In thermodynamics, a boundary is a real or imaginary volumetric demarcation region drawn around a thermodynamic system across which quantities such as heat, mass, or work can flow. In short, a thermodynamic boundary is a division between a system and its surroundings. A boundary may be adiabatic,...
  
  
• Component
  Component (thermodynamics)
  In thermodynamics, a component is a chemically distinct constituent ofa system. Calculating the number of components in a system is necessary, for example, when applying Gibbs phase rule in determination of the number of degrees of freedom of a system....
  
  
• Conjugate variables
  Conjugate variables (thermodynamics)
  In thermodynamics, the internal energy of a system is expressed in terms of pairs of conjugate variables such as temperature/entropy or pressure/volume. In fact all thermodynamic potentials are expressed in terms of conjugate pairs....
  
  
  • Temperature
    Temperature
    

    In physics, temperature is a physical property of a system that underlies the common notions of hot and cold; something that feels hotter generally has the higher temperature. Temperature is one of the principal parameters of thermodynamics...
    
     / Entropy
    Entropy
    Entropy is a concept of information maintaining great importance in physics, chemistry, and information theory...
    
    
  • Pressure
    Pressure
    

    Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
    
     / Volume
    Volume
    The volume of any solid, liquid, gas, plasma, theoretical object, or vacuum is how much three-dimensional space it occupies, often quantified numerically. One-dimensional figures and two-dimensional shapes are assigned zero volume in the three-dimensional space...
    
    
  • (Stress / Strain)
  • Chemical potential
    Chemical potential
    

    Chemical potential, symbolized by μ, is a quantity first described by the American engineer, chemist and mathematical physicist Josiah Williard Gibbs...
    
     / Particle number
    Particle number
    The particle number, N, is the number of constituent particles in a thermodynamical system. The particle number is a fundamental parameter in thermodynamics and it is conjugate to the chemical potential....
    
    
• Constant:
  • Avogadro's N_A
  • Boltzmann
    Boltzmann constant
    

    The Boltzmann constant is the physical constant relating energy at the particle level with temperature observed at the bulk level. It is the gas constant R divided by the Avogadro constant N_A:...
    
     k
  • Ideal gas
    Gas constant
    The gas constant is a physical constant which is featured in a large number of fundamental equations in the physical sciences, such as the ideal gas law and the Nernst equation...
    
     R
  • Stefan-Boltzmann σ
• Critical line
  Critical line (thermodynamics)
  In thermodynamics, a critical line is the higher-dimensional equivalent of a critical point . It is thelocus of contiguous critical points in a phase diagram. These lines cannot occur for...
  
  
• Cycle
  Thermodynamic cycle
  A thermodynamic cycle is a series of thermodynamic processes transferring heat and work, while varying pressure, temperature, and other state variables, eventually returning a system to its initial state. State Properties depend only on the thermodynamic state and cumulative variation of such...
  
  
  • External combustion engine
    External combustion engine
    An external combustion engine is a heat engine where an working fluid is heated by combustion of an external source, through the engine wall or a heat exchanger. The fluid then, by expanding and acting on the mechanism of the engine produces motion and usable work...
    
    
  • Internal combustion engine
    Internal combustion engine
    The internal combustion engine is an engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber. In an internal combustion engine the expansion of the high temperature and pressure gases, which are produced by the combustion, directly applies force to a movable...
    
    
  • Atkinson
    Atkinson cycle
    The Atkinson-cycle engine is a type of internal combustion engine invented by James Atkinson in 1882. The Atkinson cycle is designed to provide efficiency at the expense of power density and is beginning to see use in modern hybrid electric applications....
    
    
  • Bell Coleman
  • Brayton
    Brayton cycle
    The Brayton cycle is a thermodynamic cycle that describes the workings of the gas turbine engine, basis of the jet engine and others. It is named after George Brayton , the American engineer who developed it, although it was originally proposed and patented by Englishman John Barber in 1791. It is...
    
    
  • Carnot
    Carnot cycle
    Every thermodynamic system exists in a particular state. When a system is taken through a series of different states and finally returned to its initial state, a thermodynamic cycle is said to have occurred. In the process of going through this cycle, the system may perform work on its...
    
    
  • Combined
    Combined cycle
    A combined cycle is characteristic of a power producing engine or plant that employs more than one thermodynamic cycle. Heat engines are only able to use a portion of the energy their fuel generates . The remaining heat from combustion is generally wasted...
    
    
  • Diesel
    Diesel cycle
    The Diesel cycle is the thermodynamic cycle which approximates the pressure and volume of the combustion chamber of the Diesel engine, invented by Rudolph Diesel in 1897. It is assumed to have constant pressure during the first part of the "combustion" phase , v2 to v3 in the diagram...
    
    
  • Ericsson
    Ericsson cycle
    The Ericsson cycle is named after inventor John Ericsson, who designed and built many unique heat engines based on various thermodynamic cycles. He is credited with inventing two unique heat engine cycles and developing practical engines based on these cycles...
    
    
  • Hampson-Linde
    Hampson-Linde cycle
    The Hampson-Linde cycle is based on the Joule-Thomson effectand is used in the liquefaction of gases. W. Hampson and Carl von Linde independently filed for patent of the cycle in 1895.-External links:*...
    
    
  • Heat engine
    Heat engine
    A heat engine is a physical or theoretical device that converts thermal energy to mechanical output. The mechanical output is called work, and the thermal energy input is called heat. Heat engines typically run on a specific thermodynamic cycle...
    
    
    • Carnot
      Carnot heat engine
      A Carnot heat engine is a hypothetical engine that operates on the reversible Carnot cycle. The basic model for this engine was developed by Nicolas Léonard Sadi Carnot in 1824...
      
      
  • HEHC
    High-Efficiency Hybrid Cycle
    The High-Efficiency Hybrid Cycle is a new 4-stroke thermodynamic cycle combining elements of the Otto cycle, Diesel cycle, Atkinson cycle and Rankine cycle.-High-Efficiency Hybrid Cycle Engines:...
    
    
  • Hot air engine
    Hot air engine
    Hot air engine is a catch-all term for any heat engine which uses the expansion and contraction of air under the influence of a temperature change to convert thermal energy into mechanical work...
    
    
  • Heat pump & refrigeration
    Heat pump and refrigeration cycle
    Thermodynamic heat pump and refrigeration cycles are the models for heat pumps and refrigerators. The difference between a heat pump and a normal air conditioner is that a heat pump can be used to heat a home as well as cool it. Even though the heat pump can heat, it still uses the same basic...
    
    
  • Kalina
    Kalina cycle
    The Kalina cycle is a thermodynamic cycle for converting thermal energy to mechanical power, optimized for use with thermal sources which are at a relatively low temperature compared to the heat sink temperature...
    
    
  • Kleemenko
    Kleemenko cycle
    The Kleemenko cycle or one-flow cascade cycle is a single-stream mixed-refrigerant technique used to cool or liquify gases. The term Kleemenko Cycle is used in refrigeration if multi-component refrigerants are used in a cycle....
    
    
  • Lenoir
    Lenoir cycle
    The Lenoir cycle is an idealized thermodynamic cycle often used to model a pulse jet engine. It is based on the operation of an engine patented by Jean Joseph Etienne Lenoir in 1860. This engine is often thought of as the first commercially produced internal combustion engine...
    
    
  • Miller
    Miller cycle
    In engineering, the Miller cycle is a combustion process used in a type of four-stroke internal combustion engine. The Miller cycle was patented by Ralph Miller , an American engineer, in the 1940s.- Overview :...
    
    
  • Mixed/Dual
    Mixed/Dual Cycle
    Dual Combustion Cycle is a thermal cycle that is a combination of the Otto cycle and the Diesel cycle. Heat is added partly at constant volume and partly at constant pressure, the advantage of which is that more time is available for the fuel to completely combust...
    
    
  • Otto
  • Rankine
    Rankine cycle
    The Rankine cycle is a thermodynamic cycle which converts heat into work. The heat is supplied externally to a closed loop, which usually uses water as the working fluid. This cycle generates about 80% of all electric power used throughout the world, including virtually all solar thermal, biomass,...
    
    
  • Regenerative
    Regenerative cooling
    Regenerative cooling in rockets is where some or all of the propellant is passed through tubes, channels or otherwise in a jacket around the combustion chamber or nozzle to cool the engine because the fuel in particular and sometimes the oxidizer are good coolants...
    
    
  • Siemens
    Siemens cycle
    The Siemens cycle is a technique used to cool or liquefy gases.. A gas is compressed, leading to an increase in its temperature . The compressed gas is then cooled by a heat exchanger, then the cool, compressed gas is allowed to decompress, further cooling it...
    
    
  • Stirling
    Stirling cycle
    The Stirling cycle is a thermodynamic cycle that describes the general class of Stirling devices. This includes the original Stirling engine that was invented, developed and patented in 1816 by Reverend Dr...
    
    
  • Stoddard
    Stoddard engine
    Elliott J. Stoddard invented and patented two versions of the Stoddard engine, the first in 1919 and the second in 1933. The general engine classification is an external combustion engine with valves and single-phase gaseous working fluid...
    
    
• Ensemble
  Statistical ensemble (mathematical physics)
  In mathematical physics, especially as introduced into statistical mechanics and thermodynamics by J. Willard Gibbs in 1878, an ensemble is an idealization consisting of a large number of mental copies of a system, considered all at once, each of which represents a possible state that the real...
  
  
  • Canonical
    Canonical ensemble
    A canonical ensemble in statistical mechanics is a statistical ensemble representing a probability distribution of microscopic states of the system...
    
    
  • Grand canonical
    Grand canonical ensemble
    In statistical mechanics, a grand canonical ensemble is an imaginary collection of model systems put together to mirror the calculated probability distribution of microscopic states of a given physical system which is being maintained in a given macroscopic state...
    
    
  • Isoenthalpic-isobaric
    Isoenthalpic–isobaric ensemble
    The isoenthalpic-isobaric ensemble is a statistical mechanical ensemble that maintains constant enthalpy and constant pressure applied. It is also called the -ensemble, where the number of particles is also kept as a constant. It was developed by physicist H. C. Andersen in 1980...
    
    
  • Isothermal-isobaric
  • Microcanonical
    Microcanonical ensemble
    In statistical physics, the microcanonical ensemble is a theoretical tool used to describe the thermodynamic properties of an isolated system. In such a system, the possible states of the system all have the same energy and the probability for the system to be in any given state is the same.-...
    
    
• Equations
  Thermodynamic equations
  In thermodynamics, there are a large number of equations relating the variousthermodynamic quantities. In chemical thermodynamics, which is a sub-branch of thermodynamics, for example, there are millions of useful equations. In particular, the structure of chemical thermodynamics is based on the...
  
  
  • Boltzmann
    Boltzmann equation
    The Boltzmann equation, also often known as the Boltzmann transport equation, devised by Ludwig Boltzmann, describes the statistical distribution of one particle in a fluid...
    
    
  • Bridgman
    Bridgman's thermodynamic equations
    In thermodynamics, Bridgman's thermodynamic equations are a basic set of thermodynamic equations, derived using a method of generating a large number of thermodynamic identities involving a number of thermodynamic quantities. The equations are named after the American physicist Percy Williams...
    
    
  • Churchill-Bernstein
    Churchill-Bernstein Equation
    In convective heat transfer, the Churchill–Bernstein equation is used to estimate the surface averaged Nusselt number for a cylinder in cross flow at various velocities. The need for the equation arises from the inability to solve the Navier-Stokes equations in the turbulent flow regime, even for...
    
    
  • Clausius-Clapeyron relation
    Clausius-Clapeyron relation
    

    The Clausius–Clapeyron relation, named after Rudolf Clausius and Émile Clapeyron, who defined it sometime after 1834, is a way of characterizing a discontinuous phase transition between two phases of matter. On a pressure–temperature diagram, the line separating the two phases is known as the...
    
    
  • Debye-Hückel
  • Equation of state
    Equation of state
    In physics and thermodynamics, an equation of state is a relation between state variables. More specifically, an equation of state is a thermodynamic equation describing the state of matter under a given set of physical conditions...
    
    
  • Exact differential
    Exact differential
    A mathematical differential dQ is said to be exact, as contrasted with an inexact differential, if the differentiable function Q exists. However, if dQ is chosen arbitrarily, a corresponding Q might not exist.-Overview:...
    
    
  • Gibbs-Duhem
    Gibbs-Duhem equation
    The Gibbs-Duhem equation in thermodynamics describes the relationship between changes in chemical potential for components in a thermodynamical system :...
    
    
  • Gibbs-Helmholtz
    Gibbs-Helmholtz equation
    The Gibbs–Helmholtz equation is a thermodynamic equation useful for calculating changes in the Gibbs energy of a system as a function of temperature. It is named after Josiah Willard Gibbs and Hermann von Helmholtz:With:...
    
    
  • Green-Kubo relations
    Green-Kubo relations
    Green–Kubo relations give exact mathematical expression for transport coefficients in terms of integrals of time correlation functions.-Thermal and mechanical transport processes:...
    
    
  • Maxwell relations
    Maxwell relations
    Maxwell's relations are a set of equations in thermodynamics which are derivable from the definitions of the thermodynamic potentials. The Maxwell relations are statements of equality among the second derivatives of the thermodynamic potentials. They follow directly from the fact that the order of...
    
    
  • Onsager reciprocal relations
    Onsager reciprocal relations
    In thermodynamics, the Onsager reciprocal relations express the equality of certain relations between flows and forces in thermodynamic systems out of equilibrium, but where a notion of local equilibrium exists....
    
    

• Equilibrium
  Thermodynamic equilibrium
  In thermodynamics, a thermodynamic system is said to be in thermodynamic equilibrium when it is in thermal equilibrium, mechanical equilibrium, radiative equilibrium, and chemical equilibrium. Classical thermodynamics deals with dynamic equilibrium states...
  
  
  • Chemical
    Chemical equilibrium
    In a chemical process, chemical equilibrium is the state in which the chemical activities or concentrations of the reactants and products have no net change over time. Usually, this would be the state that results when the forward chemical process proceeds at the same rate as their reverse reaction...
    
    
  • Dynamic
    Dynamic equilibrium
    A system in dynamic equilibrium is a particular example of a system in a steady state. In a steady state the rate of inputs is equal to the rate of outputs so that the composition of the system is unchanging in time...
    
    
  • Local
  • Phase
    Gibbs' phase rule
    Gibbs' phase rule, was proposed by Josiah Willard Gibbs in the 1870s as the equalitywhere P is the number of phases in thermodynamic equilibrium with each other and C is the number of components. Typical phases are solids, liquids and gases. A system involving one pure chemical is an example of a...
    
    
• History
  History of thermodynamics
  The history of thermodynamics is a fundamental strand in the history of physics, the history of chemistry, and the history of science in general...
  
  
• Instruments
  Thermodynamic instruments
  A thermodynamic instrument is any device which facilitates the quantitative measurement of thermodynamic systems. In order for a thermodynamic parameter to be truly defined, a technique for its measurement must be specified. For example, the ultimate definition of temperature is "what a thermometer...
  
  
  • Barometer
    Barometer
    A barometer is an instrument used to measure atmospheric pressure. It can measure the pressure exerted by the atmosphere by using water, air, or mercury. Pressure tendency can forecast short term changes in the weather...
    
    
  • Calorimeter
    Calorimeter
    A calorimeter is a device used for calorimetry, the science of measuring the heat of chemical reactions or physical changes as well as heat capacity. The word calorimeter is derived from the Latin word calor, meaning heat. Differential scanning calorimeters, isothermal microcalorimeters, titration...
    
    
  • Dynamometer
    Dynamometer
    A dynamometer or "dyno" for short, is a device for measuring force or power. For example, the power produced by an engine, motor or other rotating prime mover can be calculated by simultaneously measuring torque and rotational speed ....
    
    
  • Thermometer
    Thermometer
    A thermometer is a device that measures temperature or temperature gradient using a variety of different principles. A thermometer has two important elements: the temperature sensor A thermometer (from the Greek θερμός (thermo) meaning "warm" and meter, "to measure") is a device that measures...
    
    
• Laws
  Laws of thermodynamics
  The laws of thermodynamics, in principle, describe the specifics for the transport of heat and work in thermodynamic processes. Since their inception, however, these laws have become some of the most important in all of physics and other types of science associated with thermodynamics.It is wise to...
  
  :
  • Zeroth
    Zeroth law of thermodynamics
    The zeroth law of thermodynamics is a generalization about the thermal equilibrium among bodies, or thermodynamic systems, in contact. It results from the definition and properties of temperature.It can be stated as:...
    
    
  • First
    First law of thermodynamics
    The first law of thermodynamics, an expression of the principle of conservation of energy, states that energy can be transformed , but cannot be created or destroyed. Alternatively:-Description:...
    
    
  • Second
    Second law of thermodynamics
    The second law of thermodynamics is an expression of the universal principle of entropy, stating that the entropy of an isolated system which is not in equilibrium will tend to increase over time, approaching a maximum value at equilibrium, and that the entropy change dS of a system undergoing any...
    
    
  • Third
    Third law of thermodynamics
    The third law of thermodynamics is a statistical law of nature regarding entropy and the impossibility of reaching absolute zero of temperature...
    
    
  • Charles's
    Charles's law
    Charles's law is an experimental gas law which describes how gases tend to expand when heated. It was first published by French natural philosopher Joseph Louis Gay-Lussac in 1802, although he credits the discovery to unpublished work from the 1780s by Jacques Charles...
    
    
  • Dulong-Petit
  • Fundamental relation
  • Gas laws
    Gas laws
    This article outlines the historical development of the laws describing ideal gases. For a detailed description of the ideal gas laws and their further development, see Ideal gas, Ideal gas law and Gas...
    
    
    • Ideal gas
      Ideal gas law
      The Ideal gas law is the equation of state of a hypothetical ideal gas. It is a good approximation to the behaviour of many gases under many conditions, although it has several limitations. It was first stated by Émile Clapeyron in 1834 as a combination of Boyle's law and Charles's law...
      
      
  • Joule's
  • Onsager reciprocal relations
    Onsager reciprocal relations
    In thermodynamics, the Onsager reciprocal relations express the equality of certain relations between flows and forces in thermodynamic systems out of equilibrium, but where a notion of local equilibrium exists....
    
    
  • Stefan-Boltzmann
    Stefan-Boltzmann law
    The Stefan–Boltzmann law, also known as Stefan's law, states that the total energy radiated per unit surface area of a black body in unit time , j^*, is directly proportional to the fourth power of the black body's thermodynamic temperature...
    
    
• Limit
  Thermodynamic limit
  In physics and physical chemistry, the thermodynamic limit is reached as the number of particles in a system, N, approaches infinity — or in practical terms, one mole or Avogadro's number ≈ 6 x 10²³...
  
  
• Material properties
  Material properties (thermodynamics)
  The thermodynamic properties of materials are intensive thermodynamic parameters which are specific to a given material. Each is directly related to a second order differential of a thermodynamic potential...
  
  
  • Bulk modulus
    Bulk modulus
    The bulk modulus of a substance measures the substance's resistance to uniform compression. It is defined as the pressure increase needed to cause a given relative decrease in volume. Its base unit is Pascal....
    
     K
  • Compressibility
    Compressibility
    In thermodynamics and fluid mechanics, compressibility is a measure of the relative volume change of a fluid or solid as a response to a pressure change.where V is volume and p is pressure...
    
     β
  • Specific heat capacity
    Specific heat capacity
    Specific heat capacity, often shortened to specific heat, is the measure of the heat energy required to increase the temperature of a of a substance by unit degree. The term originated primarily through the work of 18th-century physicist Joseph Black who conducted various heat measurements and...
    
     c
  • Thermal expansion
    Thermal expansion
    Thermal expansion is the tendency of a matter to change in volume in response to a change in temperature. When a substance is heated, its particles begin moving and become active thus maintaining a greater average separation. Materials which contract with increasing temperature are rare; this...
    
     α
• Potential
  • Internal energy
    Internal energy
    In thermodynamics, the internal energy of a thermodynamic system, or a body with well-defined boundaries, denoted by U, or sometimes E, is the total of the kinetic energy due to the motion of molecules and the potential energy associated with the vibrational and electric energy of atoms...
    
    
  • Entropy
    Entropy
    Entropy is a concept of information maintaining great importance in physics, chemistry, and information theory...
    
    
  • Gibbs free energy
    Gibbs free energy
    In thermodynamics, the Gibbs free energy is a thermodynamic potential that measures the "useful" or process-initiating work obtainable from an isothermal, isobaric thermodynamic system...
    
    
  • Grand
    Grand potential
    The grand potential is a quantity used in statistical mechanics, especially for irreversible processes in open systems.Grand potential is defined by...
    
    
  • Helmholtz free energy
    Helmholtz free energy
    In thermodynamics, the Helmholtz free energy is a thermodynamic potential which measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume...
    
    
• Process
  • Adiabatic
    Adiabatic process
    In thermodynamics, an adiabatic process or an isocaloric process is a thermodynamic process in which no heat is transferred to or from the working fluid. The term "adiabatic" literally means impassable, coming from the Greek roots ἀ- , διὰ- , and βαῖνειν ; this etymology corresponds here to an...
    
    
  • Isenthalpic
    Isenthalpic process
    An isenthalpic process or isoenthalpic process is a process that proceeds without any change in enthalpy, H; or specific enthalpy, h....
    
    
  • Isentropic
    Isentropic process
    In thermodynamics, an isentropic process or isoentropic process is one during which the entropy of the system remains constant...
    
    
  • Isobaric
    Isobaric process
    An isobaric process is a thermodynamic process in which the pressure stays constant: The term derives from the Greek isos, meaning "equal," and barus, "heavy." The heat transferred to the system does work but also changes the internal energy of the system:According to the first law of...
    
    
  • Isochoric
    Isochoric process
    An isochoric process, also called a constant-volume process, an isovolumetric process, or an isometric process, is a thermodynamic process during which the volume of the closed system undergoing such process remains constant...
    
    
  • Isothermal
    Isothermal process
    An isothermal process is a change in which the temperature of the system stays constant: ΔT = 0. This typically occurs when a system is in contact with an outside thermal reservoir , and the change occurs slowly enough to allow the system to continually adjust to the temperature of the...
    
    
  • Quasistatic
    Quasistatic process
    In thermodynamics, a quasistatic process is a thermodynamic process that happens infinitely slowly. In practice, such processes can be approximated by performing them "very slowly"....
    
    
  • Spontaneous
    Spontaneous process
    A spontaneous process is the time-evolution of a system in which it releases free energy and moves to a lower, more thermodynamically stable, energy state...
    
    
  • Steady state
    Steady state
    A system in a steady state has numerous properties that are unchanging in time. The concept of steady state has relevance in many fields, in particular thermodynamics. Steady state is a more general situation than dynamic equilibrium. If a system is in steady state, then the recently observed...
    
    
• State
  Thermodynamic state
  A thermodynamic state is a set of values of properties of a thermodynamic system that must be specified to reproduce the system. The individual parameters are known as state variables, state parameters or thermodynamic variables. Once a sufficient set of thermodynamic variables have been...
  
  
  • Excited
    Excited state
    Excitation is an elevation in energy level above an arbitrary baseline energy state. In physics there is a specific technical definition for energy level which is often associated with an atom being excited to an excited state....
    
    
  • Function
    State function
    In thermodynamics, a state function, state quantity, or a function of state, is a property of a system that depends only on the current state of the system, not on the way in which the system acquired that state. A state function describes the equilibrium state of a system...
    
    
  • Ground
    Stationary state
    In quantum mechanics, a stationary state is an eigenstate of a Hamiltonian, or in other words, a state of definite energy. It is called stationary because the corresponding probability density has no time dependence....
    
    
  • Standard
    Standard state
    In chemistry, the standard state of a material is a reference point used to calculate its properties under different conditions. In principle, the choice of standard state is arbitrary, although the International Union of Pure and Applied Chemistry recommends a conventional set of standard states...
    
    
  • Stationary
    Stationary state
    In quantum mechanics, a stationary state is an eigenstate of a Hamiltonian, or in other words, a state of definite energy. It is called stationary because the corresponding probability density has no time dependence....
    
    
  • Steady
    Steady state
    A system in a steady state has numerous properties that are unchanging in time. The concept of steady state has relevance in many fields, in particular thermodynamics. Steady state is a more general situation than dynamic equilibrium. If a system is in steady state, then the recently observed...
    
    
• System
  Thermodynamic system
  In thermodynamics, a thermodynamic system, originally called a working substance, is defined as that part of the universe that is under consideration. A hypothetical boundary separates the system from the rest of the universe, which is referred to as the environment, surroundings, or reservoir...
  
  
  • Closed
    Closed system
    A closed system is a system in the "state of being isolated from its surrounding environment." The term often refers to an idealized system in which closure is perfect. In reality no system can be completely closed; there are only varying degrees of closure....
    
    
  • Dissipative
    Dissipative system
    A dissipative system is a thermodynamically open system which is operating far from thermodynamic equilibrium in an environment with which it exchanges energy and matter.- Overview :...
    
    
  • Isolated
    Isolated system
    In the natural sciences an isolated system, as contrasted with a open system, is a physical system that does not interact with its surroundings. It obeys a number of conservation laws: its total energy and mass stay constant. They cannot enter or exit, but can only move around inside...
    
    
• Temperature
  Thermodynamic temperature
  Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is an “absolute” scale because it is the measure of the fundamental property underlying temperature: its null or zero point, absolute zero, is the...
  
  
  • Negative
    Negative temperature
    In physics, certain systems can achieve negative temperatures; that is, their thermodynamic temperature can be of a negative quantity. Negative temperatures can be expressed as negative numbers on the kelvin scale....
    
    
  • Range
    Temperature range
    Temperature range is the numerical difference between the minimum and maximum values of temperature observed in a system, such as atmospheric temperature in a given location.-Atmospheric temperature range:...
    
    

• Chemical potential
  Chemical potential
  Chemical potential, symbolized by μ, is a quantity first described by the American engineer, chemist and mathematical physicist Josiah Williard Gibbs...
  
   μ
• Density
  Density
  The density of a material is defined as its mass per unit volume. The symbol of density is ρ .- Formula :Mathematically:where: is the density, is the mass, is the volume....
  
  
• Energy
  Energy
  In physics, energy is a scalar physical quantity that describes the amount of work that can be performed by a force, an attribute of objects and systems that is subject to a conservation law...
  
  
  • Conservation of
    Conservation of energy
    The law of conservation of energy states that the total amount of energy in a closed system remains constant. A consequence of this law is that energy cannot be created nor destroyed...
    
    
  • Conversion efficiency
    Energy conversion efficiency
    Energy conversion efficiency is the ratio between the useful output of an energy conversion machine and the input, in energy terms. The useful output may be electric power, mechanical work, or heat. Energy conversion efficiency is not defined uniquely, but instead depends on the usefulness of the...
    
    
  • Electrical
  • Free
    Thermodynamic free energy
    In thermodynamics, the term thermodynamic free energy refers to the amount of work that can be extracted from a system, and is helpful in engineering applications...
    
    
  • Gibbs free
    Gibbs free energy
    In thermodynamics, the Gibbs free energy is a thermodynamic potential that measures the "useful" or process-initiating work obtainable from an isothermal, isobaric thermodynamic system...
    
     G
  • Helmholtz free
    Helmholtz free energy
    In thermodynamics, the Helmholtz free energy is a thermodynamic potential which measures the “useful” work obtainable from a closed thermodynamic system at a constant temperature and volume...
    
     A
  • Internal
    Internal energy
    In thermodynamics, the internal energy of a thermodynamic system, or a body with well-defined boundaries, denoted by U, or sometimes E, is the total of the kinetic energy due to the motion of molecules and the potential energy associated with the vibrational and electric energy of atoms...
    
     U
  • Kinetic
    Kinetic energy
    The kinetic energy of an object is the extra energy which it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its current velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its...
    
    
  • Potential
    Potential energy
    Potential energy is energy stored within a physical system as a result of the position or configuration of the different parts of that system. It is called potential energy because it has the potential to be converted into other forms of energy, such as kinetic energy, and to do work in the process...
    
    
  • Specific
    Specific energy
    Specific energy is defined as the energy per unit mass. Common metric units are J/kg or, in basic SI units: m²/s². It is an intensive property. Contrast this with energy, which is an extensive property. There are two main types of specific energy: field strength and strength...
    
    
• Enthalpy
  Enthalpy
  In thermodynamics and molecular chemistry, the enthalpy is a thermodynamic property of a thermodynamic system. It can be used to calculate the heat transfer during a quasistatic process taking place in a closed thermodynamic system under constant pressure...
  
   H
• Entropy
  Entropy
  Entropy is a concept of information maintaining great importance in physics, chemistry, and information theory...
  
   S
  • & information theory
    Entropy in thermodynamics and information theory
    There are close parallels between the mathematical expressions for the thermodynamic entropy, usually denoted by S, of a physical system in the statistical thermodynamics established by Ludwig Boltzmann and J. Willard Gibbs in the 1870s; and the information-theoretic entropy, usually expressed as...
    
    
  • As energy dispersal
    Entropy (energy dispersal)
    The description of entropy as energy dispersal provides an introductory method of teaching the thermodynamic concept of entropy. In physics and physical chemistry, entropy has commonly been defined as a scalar measure of the disorder of a thermodynamic system...
    
    
  • Introduction to
    Introduction to entropy
    In thermodynamics, entropy is a measure of certain aspects of energy in relation to absolute temperature. In thermodynamics, entropy is one of the three basic thermodynamic potentials: U , S and A...
    
    
  • Residual
    Residual entropy
    Residual entropy is physically significant entropy, which is present even after a substance is cooled arbitrarily close to absolute zero. That is, if a material is reduced to its ground state, residual entropy occurs if the material can exist in multiple different ground states that have the same...
    
    
  • Shannon
  • Statistical
• Exergy
  Exergy
  In thermodynamics, the exergy of a system is the maximum work possible during a process that brings the system into equilibrium with a heat reservoir. When the surroundings are the reservoir, exergy is the potential of a system to cause a change as it achieves equilibrium with its environment. ...
  
  
  • Efficiency
    Exergy efficiency
    Exergy efficiency computes the efficiency of a process taking the second law of thermodynamics into account.-Motivation:...
    
    
• Mass
  Mass
  In physics, mass commonly refers to any of three properties of matter, which have been shown experimentally to be equivalent: inertial mass, active gravitational mass and passive gravitational mass...
  
  
• Mole (unit)
  Mole (unit)
  The mole is a unit of amount of substance: it is an SI base unit, and one of the few units used to measure this physical quantity. The name "mole" was coined in German by Wilhelm Ostwald in 1893, although the related concept of equivalent mass had been in use at least a century earlier...
  
  
• Particle number
  Particle number
  The particle number, N, is the number of constituent particles in a thermodynamical system. The particle number is a fundamental parameter in thermodynamics and it is conjugate to the chemical potential....
  
   N
• Pressure
  Pressure
  Pressure is the force per unit area applied in a direction perpendicular to the surface of an object. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure.- Definition :...
  
   P
• Temperature
  Thermodynamic temperature
  Thermodynamic temperature is the absolute measure of temperature and is one of the principal parameters of thermodynamics. Thermodynamic temperature is an “absolute” scale because it is the measure of the fundamental property underlying temperature: its null or zero point, absolute zero, is the...
  
   T
• Volume
  Volume
  The volume of any solid, liquid, gas, plasma, theoretical object, or vacuum is how much three-dimensional space it occupies, often quantified numerically. One-dimensional figures and two-dimensional shapes are assigned zero volume in the three-dimensional space...
  
   V
• Work
  Work (thermodynamics)
  In thermodynamics, work performed by a system is the quantity of energy transferred by the system to another due to changes in the external parameters of the system. If these changes happen in a reversible way, then the performed work does not lead to a change of the entropy. It is a...
  
   W
  • Mechanical
    Mechanical work
    In physics, mechanical work is the amount of energy transferred by a force acting through a distance. Like energy, it is a scalar quantity, with SI units of joules...
    
    

• Carnot's
• Clausius
  Clausius theorem
  The Clausius theorem states that in a cyclic processThe equality holds in the reversible case and the '<' is in the irreversible case. The reversible case is used to introduce the function state entropy...
  
  
• Equipartition
  Equipartition theorem
  In classical statistical mechanics, the equipartition theorem is a general formula that relates the temperature of a system with its average energies. The equipartition theorem is also known as the law of equipartition, equipartition of energy, or simply equipartition...
  
  
• Bolzmann's H
  H-theorem
  In thermodynamics, the H-theorem, introduced by Ludwig Boltzmann in 1872, describes the increase in the entropy of an ideal gas in an irreversible process, by considering the Boltzmann equation....
  
  
• Nernst heat
  Nernst heat theorem
  The Nernst heat theorem was formulated by Walther Nernst early in the twentieth century and was used in the development of the third law of thermodynamics.- The theorem :...
  
  
• Virial
  Virial theorem
  In mechanics, the virial theorem provides a general equation relating the average over time of the total kinetic energy, , of a stable system, bound by potential forces, with that of the total potential energy, , where angle brackets represent the average over time of the enclosed quantity...
  
  

• Critical heat flux
  Critical heat flux
  Critical heat flux describes the thermal limit of a phenomenon where a phase change occurs during heating , which suddenly decreases the efficiency of heat transfer, thus causing localised overheating of the heating surface.The Critical heat flux for ignition is the lowest thermal load per unit...
  
  
• Heat of combustion
  Heat of combustion
  The heat of combustion is the energy released as heat when one mole of a compound undergoes complete combustion with oxygen. The chemical reaction is typically a hydrocarbon reacting with oxygen to form carbon dioxide, water and heat...
  
  
• Heat transfer
  Heat transfer
  Heat transfer is the transition of thermal energy from a hotter object to a cooler object...
  
  
  • Convective
• Latent heat
  Latent heat
  The expression latent heat refers to the amount of energy released or absorbed by a chemical substance during a change of state that occurs without changing its temperature, meaning a phase transition such as the melting of ice or the boiling of water...
  
  
• Mechanical equivalent
  Mechanical equivalent of heat
  In the history of science, the mechanical equivalent of heat was a concept that had an important part in the development and acceptance of the conservation of energy and the establishment of the science of thermodynamics in the 19th century....
  
  
• Theory of heat
  Theory of heat
  In the history of science, the theory of heat or mechanical theory of heat was a theory, introduced predominantly in 1824 by the French physicist Sadi Carnot, that heat and mechanical work are equivalent. It is related to the mechanical equivalent of heat...
  
  
• Volumetric heat capacity
  Volumetric heat capacity
  Volumetric heat capacity describes the ability of a given volume of a substance to store internal energy while undergoing a given temperature change, but without undergoing a phase change. It is different from specific heat capacity in that the VHC depends on the volume of the material, while the...
  
  

• Analysis
  Thermal analysis
  Thermal analysis is a branch of materials science where the properties of materials are studied as they change with temperature. Several methods are commonly used - these are distinguished from one another by the property which is measured:...
  
  
• Conductivity
  Thermal conductivity
  In physics, thermal conductivity, , is the property of a material that indicates its ability to conduct heat. It appears primarily in Fourier's Law for heat conduction.-Measurement:...
  
  
• Contact
  Thermal contact
  In heat transfer and thermodynamics, a thermodynamic system is said to be in thermal contact with another system if it can exchange energy with it through the process of heat. Perfect thermal isolation is an idealization as real systems are always in thermal contact with their environment to some...
  
  
• Efficiency
  Thermal efficiency
  In thermodynamics, the thermal efficiency is a dimensionless performance measure of a thermal device such as an internal combustion engine, a boiler, or a furnace, for example. The input, , to the device is heat, or the heat-content of a fuel that is consumed. The desired output is mechanical...
  
  
• Energy
• Equilibrium
• Expansion
  Thermal expansion
  Thermal expansion is the tendency of a matter to change in volume in response to a change in temperature. When a substance is heated, its particles begin moving and become active thus maintaining a greater average separation. Materials which contract with increasing temperature are rare; this...
  
  
  • Negative
    Negative thermal expansion
    Negative Thermal Expansion is a physicochemical process in which some materials contract upon heating rather than expanding as most materials do. Materials which undergo this unusual process have a range of potential engineering, photonic, electronic, and structural applications...
    
    
• Mass
  Thermal mass
  Thermal mass is the capacity of a body to store heat. It is typically measured in units of J/°C or J/K . If the body consists of a homogeneous material with sufficiently known physical properties, the thermal mass is simply the amount of material present times the specific heat capacity of that...
  
  
• Motion
• Radiation
  Thermal radiation
  Thermal radiation is electromagnetic radiation emitted from the surface of an object which is due to the object's temperature. An example of thermal radiation is the infrared radiation emitted by a common household radiator or electric heater. A person near a raging bonfire will feel the radiated...
  
  
• Science
  Thermal science
  Thermal science is the combined study of thermodynamics, fluid mechanics, heat transfer, and combustion. This umbrella-subject is typically designed for non-engineering students and functions to provide a general introduction to each of three core heat-related subjects.-Overview:Introductory...
  
  

• Autocatalytic reactions and order creation
• Boiling point
  Boiling point
  The boiling point of an element or a substance is the temperature at which the vapor pressure of the liquid equals the environmental pressure surrounding the liquid....
  
  
• Calorimetry
  Calorimetry
  Calorimetry is the science of measuring the heat of chemical...
  
  
• Chemical energetics
• Chemical kinetics
  Chemical kinetics
  Chemical kinetics, also known as reaction kinetics, is the study of rates of chemical processes. Chemical kinetics includes investigations of how different experimental conditions can influence the speed of a chemical reaction and yield information about the reaction's mechanism and transition...
  
  
• Endergonic reaction
  Endergonic reaction
  In chemical thermodynamics, an endergonic reaction is a chemical reaction in which the standard change in free energy is positive, and energy is absorbed...
  
  
• Endothermic
  Endothermic
  In thermodynamics, the word endothermic "within-heating" describes a process or reaction that absorbs energy in the form of heat. Its etymology stems from the Greek prefix endo-, meaning “inside” and the Greek suffix –thermic, meaning “to heat”. The opposite of an endothermic process is an...
  
  
• Exothermic
  Exothermic
  In thermodynamics, the term exothermic describes a process or reaction that releases energy usually in the form of heat, but also in the form of light , electricity , or sound. Its etymology stems from the Greek prefix ex- and the Greek word thermein...
  
  
• Gibbs phase rule
• Melting point
  Melting point
  The melting point of a solid is the temperature range at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. When considered as the temperature of the reverse change from liquid to solid, it is referred to as the freezing point...
  
  
• Phase diagram
  Phase diagram
  A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically-distinct phases can occur at equilibrium...
  
  
  • Calphad
• Phase transition
  Phase transition
  A phase transition is a natural physical process. It has the characteristic of taking a given medium with given properties and transforming some or all of that medium, into a new medium with new properties. Phase transitions occur frequently and are found everywhere in the natural world...
  
  
• Thermodynamic databases for pure substances
  Thermodynamic databases for pure substances
  Thermodynamic databases contain information about thermodynamic properties for substances, the most important being enthalpy, entropy, and Gibbs free energy. Numerical values of these thermodynamic properties are collected as tables or are calculated from thermodynamic datafiles...
  
  
• Triple point
  Triple point
  In thermodynamics, the triple point of a substance is the temperature and pressure at which three phases of that substance coexist in thermodynamic equilibrium...
  
  
• Vapor-liquid equilibrium
  Vapor-liquid equilibrium
  Vapor-liquid equilibrium, abbreviated as VLE by some, is a condition where a liquid and its vapor are in equilibrium with each other, a condition or state where the rate of evaporation equals the rate of condensation on a molecular level such that there is no net vapor-liquid interconversion...
  
  

• Boltzmann distribution
  Boltzmann distribution
  In physics and mathematics, the Boltzmann distribution is a certain distribution function or probability measure for the distribution of the states of a system. It underpins the concept of the canonical ensemble, providing its underlying distribution...
  
  
• Boltzmann distribution law
• Boltzmann factor
  Boltzmann factor
  In physics, the Boltzmann factor is a weighting factor that determines the relative probability of a state in a multi-state system in thermodynamic equilibrium at temperature .Where is Boltzmann's constant, and is the energy of state...
  
  
• Bose-Einstein condensate
• Bose-Einstein statistics
• Brownian motion
  Brownian motion
  Brownian motion is the seemingly random movement of particles suspended in a fluid or the mathematical model used to describe such random movements, often called a particle theory....
  
  
• Configuration integral
  Configuration integral
  The classical configuration integral, more commonly called the partition function, andsometimes referred to asthe configurational partition function,for a system withparticlesis defined as follows:whereisthe volume enclosing theparticles,...
  
  
• Degeneracy
  Degeneracy
  Degeneracy , from the Latin de-generare "to depart from its kind or genus, to fall from its proper or ancestral quality" can refer to:*In science and mathematics:...
  
  
• Degrees of freedom
  Degrees of freedom
  Degrees of freedom can mean:* Degrees of freedom * Degrees of freedom * Degrees of freedom...
  
  
• Fermi-Dirac statistics
  Fermi-Dirac statistics
  Fermi-Dirac statistics is a part of the science of physics that describes the energies of single particles in a system comprising many identical particles that obey the Pauli Exclusion Principle...
  
  
• Fluctuations
• Gibbs paradox
  Gibbs paradox
  Originally considered by Josiah Willard Gibbs in his paper On the Equilibrium of Heterogeneous Substances, the Gibbs paradox applies to thermodynamics. It involves the discontinuous nature of the entropy of mixing...
  
  
• Ideal gas
  Ideal gas
  An ideal gas is a theoretical gas composed of a set of randomly-moving point particles that interact only through elastic collisions. The ideal gas concept is useful because it obeys the ideal gas law, a simplified equation of state, and is amenable to analysis under statistical mechanics.At...
  
  
• Irreversibility
  Irreversibility
  In science, a process that is not reversible is called irreversible. This concept arises most frequently in thermodynamics, as applied to processes...
  
  
• Kinetic theory
  Kinetic theory
  Kinetic theory is the theory that gases are made up of a large number of small particles , all of which are in constant, random motion. The rapidly moving particles constantly collide with each other and with the walls of the container...
  
  
• Macrostate
• Maxwell-Boltzmann statistics
• Microstate
  Microstate (statistical mechanics)
  In statistical mechanics, a microstate describes a specific detailed microscopic configuration of a thermodynamic system that the system visits in the course of its thermal fluctuations....
  
  
• Molecular chaos
  Molecular chaos
  In kinetic theory in physics, molecular chaos is the assumption that the velocities of colliding particles are uncorrelated, and independent of position...
  
  
• Partition function
  Partition function (statistical mechanics)
  In statistical mechanics, the partition function Z is an important quantity that encodes the statistical properties of a system in thermodynamic equilibrium. It is a function of temperature and other parameters, such as the volume enclosing a gas...
  
  

• Nernst effect
  Nernst effect
  In physics and chemistry, the Nernst Effect is a thermoelectric phenomenon observed when a sample allowing electrical conduction is subjected to a magnetic field and a temperature gradient normal to each other...
  
  
• Peltier effect
• Seebeck effect
• Thermionic emission
  Thermionic emission
  Thermionic emission is the heat-induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the forces restraining it. The charge carriers can be electrons or ions, and in older literature are sometimes...
  
  
• Thermoelectric effect
  Thermoelectric effect
  The thermoelectric effect is the direct conversion of temperature differences to electric voltage and vice versa. A thermoelectric device creates a voltage when there is a different temperature on each side. Conversely when a voltage is applied to it, it creates a temperature difference...
  
  
• Thermoelectricity
  Thermoelectricity
  Thermoelectricity refers to a class of phenomena in which a temperature difference creates an electric potential or an electric potential creates a temperature difference. In modern technical usage, the term almost always refers collectively to the Seebeck effect, Peltier effect, and the Thomson...
  
  
• Thermogenerator
  Thermogenerator
  Thermogenerators are devices which convert heat directly into electrical energy. For the most part, this term is synonymous with "thermoelectric generator" and rarely used in English. Essentially they work on the principle of the Seebeck effect, with typical efficiencies of around 5-10%...
  
  
• Thermophotovoltaic
  Thermophotovoltaic
  Thermophotovoltaic energy conversion is a direct conversion process from heat differentials to electricity via photons. A basic thermophotovoltaic system consists of a thermal emitter and a photovoltaic diode cell....
  
  
• Thermopower
  Thermopower
  The thermopower, or thermoelectric power of a material is a measure of the magnitude of an induced thermoelectric voltage in response to a temperature difference across that material...
  
  
• Thomson effect

• Absolute zero
  Absolute zero
  Absolute zero is a temperature marked by a 0 entropy configuration. It is the coldest temperature theoretically possible and cannot be reached by artificial or natural means, because it is impossible to decouple a system fully from the rest of the universe...
  
  
• Arrow of time
  Arrow of time
  In the natural sciences, arrow of time, or time’s arrow, is a term coined in 1927 by British astronomer Arthur Eddington used to distinguish a direction of time on a four-dimensional relativistic map of the world, which, according to Eddington, can be determined by a study of organizations of...
  
  
• Black body
  Black body
  In physics, a black body is an idealized object that absorbs all electromagnetic radiation that falls on it. No electromagnetic radiation passes through it and none is reflected. Because no light is reflected or transmitted, the object appears black when it is cold. However, a black body emits a...
  
  
• Dissipation
  Dissipation
  In physics, dissipation embodies the concept of a dynamical system where important mechanical modes, such as waves or oscillations, lose energy over time, typically due to the action of friction or turbulence. The lost energy is converted into heat, raising the temperature of the system...
  
  
• Ettingshausen effect
• Extensive quantity
• Intensive quantity
• Legendre transformation
  Legendre transformation
  In mathematics, the Legendre transformation or Legendre transform, named after Adrien-Marie Legendre, is an operation that transforms one real-valued function of a real variable into another...
  
  
• Loschmidt's paradox
  Loschmidt's paradox
  Loschmidt's paradox, also known as the reversibility paradox, is the objection that it should not be possible to deduce an irreversible process from time-symmetric dynamics...
  
  
• Mass-energy equivalence
  Mass-energy equivalence
  In physics, mass–energy equivalence is the concept that the mass of a body is a measure of its energy content. The mass of a body as measured on a scale is always equal to the total energy inside, multiplied by a constant c² that changes the units appropriately:where E is energy, m is...
  
  
• Physical information
  Physical information
  In physics, physical information refers generally to the information that is contained in a physical system. Its usage in quantum mechanics is important, for example in the concept of quantum entanglement to describe effectively direct or causal relationships between apparently distinct or...
  
  
• Piezoelectric effect
• Pressure volume diagram
  Pressure volume diagram
  A pressure volume diagram ) is used to describe a thermal cycle involving the following two variables:* Volume * Pressure...
  
  
• Pyroelectric effect
• Quality of a fluid
  Quality (physics)
  In physics, quality has several different meanings.- Thermodynamics :The quality of a fluid is the percentage of mass that is vapor; i.e. saturated vapor has a "quality" of 100%, and saturated liquid has a "quality" of 0%...
  
  
• Refrigeration
  Refrigeration
  Refrigeration is the process of removing heat from an enclosed space, or from a substance, and moving it to a place where it is unobjectionable. The primary purpose of refrigeration is lowering the temperature of the enclosed space or substance and then maintaining that lower temperature.The term...
  
  
  • Gas asbsorption
  • Cycle
    Heat pump and refrigeration cycle
    Thermodynamic heat pump and refrigeration cycles are the models for heat pumps and refrigerators. The difference between a heat pump and a normal air conditioner is that a heat pump can be used to heat a home as well as cool it. Even though the heat pump can heat, it still uses the same basic...
    
    
  • Thermoelectric cooling
    Thermoelectric cooling
    Thermoelectric cooling uses the Peltier effect to create a heat flux between the junction of two different types of materials. A Peltier cooler, heater, or thermoelectric heat pump is a solid-state active heat pump which transfers heat from one side of the device to the other side against the...
    
    
  • Vapor compression
• Standard conditions for temperature and pressure
  Standard conditions for temperature and pressure
  In physical sciences, standard conditions for temperature and pressure are standard sets of conditions for experimental measurements, to allow comparisons to be made between different sets of data...
  
  
• Thermodynamic paradox
  Thermodynamic paradox
  The thermodynamic paradox is an argument attempting to use thermodynamics to make deductions about the nature of the universe, specifically it attempts to argue against the steady state model of the universe using reductio ad absurdum....
  
  
• T-symmetry
  T-symmetry
  T Symmetry is the symmetry of physical laws under a time reversal transformation —Although in restricted contexts one may find this symmetry, the observable universe itself does not show symmetry under time reversal, due to the second law of thermodynamics.Hence time asymmetries are generally...
  
  
• Two dimensional gas