Edgepedia

Thermochemistry

Thermochemistry is the branch of chemical thermodynamics that studies heat and enthalpy changes in reactions, applying the first law of thermodynamics and using calorimetry and Hess's law.

Thermochromism is the ability of a material to change color with temperature, caused by a temperature-driven shift in its light absorption, and used in temperature indicators, smart windows, and anti-counterfeiting printing.

Thermochronology

Thermochronology is a family of geochronologic dating methods that determine when and how fast rocks cooled through temperature-sensitive isotopic and fission-track systems, reconstructing a rock's thermal history.

Thermocline

The thermocline, also called the metalimnion in lakes, is the water layer where temperature drops fastest with depth, separating warm surface water from the deep ocean.

Thermocline storage

Thermocline storage is a single-tank method of thermal energy storage in which hot and cold fluid occupy one insulated vessel, separated by a temperature gradient rather than a barrier.

Thermocline thermal storage

Thermocline thermal storage is a single-tank thermal energy storage design in which hot and cold fluid share one tank, cutting costs in concentrated solar power plants.

Thermococcales

Thermococcales, an order of hyperthermophilic Euryarchaeota including Pyrococcus, Thermococcus, and Palaeococcus; anaerobic heterotrophs from hydrothermal vents that ferment peptides and sugars to H2, CO2, and acetate and reduce sulfur via the Mbh and Mbx complexes.

Thermococci

Thermococci (Thermococcales): a class of hyperthermophilic, anaerobic euryarchaeal Archaea with genera Pyrococcus, Thermococcus, and Palaeococcus; source of Pfu and Vent DNA polymerases; P. furiosus grows optimally at 100°C.

Thermococcus

Thermococcus is a genus of hyperthermophilic, heterotrophic marine archaea in the order Thermococcales, type species T. celer (Zillig 1983), with about 41 validly named species from hydrothermal vents; they ferment peptides and sugars, reduce elemental sulfur, and supply PCR polymerases such as Vent and KOD.

Thermococcus celer

Thermococcus celer (Zillig 1983) is a hyperthermophilic archaeon from Vulcano, Italy, the type species of genus Thermococcus; grows optimally at 88 °C, pH 5.8, 3.8 g/l NaCl, with fast growth.

Thermococcus gammatolerans

Thermococcus gammatolerans is a hyperthermophilic, radiation-resistant archaeon from deep-sea hydrothermal vents, described in 2003. It survives gamma doses of about 7.5 kGy, more than any other archaeon known then.

Thermococcus litoralis

Thermococcus litoralis (Vent, Tli) is a hyperthermophilic marine archaeon from Italian submarine springs, growing up to 98 °C; source of Vent DNA polymerase, the first thermostable proofreading PCR enzyme, type strain DSM 5473.

Thermocompression bonding

Thermocompression bonding is a solid-state welding method that joins chips, wafers, or substrates by applying heat and pressure together, used in wire bonding, flip-chip packaging, and 3D integration.

Thermocouple

A thermocouple, also known as a thermoelectric thermometer, is a temperature sensor of two dissimilar metal wires joined at one end, generating voltage from temperature difference.

Thermodilution

Thermodilution is a hemodynamic monitoring technique that measures cardiac output by injecting cold fluid into the bloodstream and recording the temperature change downstream, used in intensive care.

Thermodynamic activity

Thermodynamic activity, also called chemical activity or effective concentration, is a dimensionless measure of a species' effective concentration used to treat real mixtures like ideal ones.

Thermodynamic cycle

A thermodynamic cycle is a sequence of processes in which a working substance returns to its initial state; it models engines, refrigerators, heat pumps, and power plants.

Thermodynamic equilibrium

Thermodynamic equilibrium is the state of a system in which no net exchange of heat, volume, or particles occurs, requiring simultaneous thermal, mechanical, and chemical equilibrium.

Thermodynamic free energy

Thermodynamic free energy is the portion of a system's internal energy available to do work at constant temperature, taking the form of Helmholtz or Gibbs free energy.

Thermodynamic integration

Thermodynamic integration is a molecular simulation method that estimates free energy differences by slowly transforming a system between two states and integrating the energy derivative.

Thermodynamic length

Thermodynamic length is a metric distance between equilibrium thermodynamic states, first defined by Frank Weinhold in 1975, that bounds the dissipation of finite-time thermodynamic processes.

Thermodynamic potential

A thermodynamic potential is a state function encoding a system's energy in particular variables; the four canonical ones are internal energy, enthalpy, Helmholtz energy, and Gibbs energy.

Thermodynamic potentials

Thermodynamic potentials are state functions of a thermodynamic system, minimized at equilibrium under specified constraints: the internal energy, enthalpy, Helmholtz function, and Gibbs function, each suited to different experimental conditions.

Thermodynamic square

The thermodynamic square, also called the Maxwell square, is a mnemonic diagram in classical thermodynamics that lets students reconstruct the four Maxwell relations without memorizing them.

Thermodynamic system

A thermodynamic system is any quantity of matter whose thermodynamic properties are of interest, set apart from its surroundings by a boundary that heat, work, and sometimes matter cross.

Thermodynamic temperature

Thermodynamic temperature, also called absolute temperature, is the absolute temperature defined by the laws of thermodynamics, measured in kelvins with its zero at absolute zero.

Oct 22, 2026

Thermodynamic uncertainty relation

The thermodynamic uncertainty relation (TUR) is a result of stochastic thermodynamics stating that the precision of currents in nonequilibrium steady states is bounded by entropy production.

Thermodynamics

Thermodynamics is the branch of physical science that deals with relationships between heat, work, and other forms of energy, built on laws numbered zeroth through third.

Thermodynamics of information

The thermodynamics of information, also called information thermodynamics, is the branch of nonequilibrium statistical mechanics that treats information, such as a measurement outcome, as a physical quantity on the same footing as energy and entropy.