Classical thermodynamics deals with states of dynamic equilibrium.
Termodinamika klasik meliputi keadaan kesetimbangan dinamis.
One such potential is the Helmholtz free energy (A), for a closed system at constant volume and temperature (controlled by a heat bath): AU − T S Another potential, the Gibbs free energy (G), is minimized at thermodynamic equilibrium in a closed system at constant temperature and pressure, both controlled by the surroundings: GU − T S + P V where T denotes the absolute thermodynamic temperature, P the pressure, S the entropy, V the volume, and U the internal energy of the system.
Untuk lebih spesifik, kesetimbangan termodinamika dikarakteristikkan oleh potensial termodinamika minimum, seperti energi bebas Helmhlotz, yaitu sistem pada suhu dan volume sama: AU - TS; atau energi bebas Gibbs, yaitu sistem dengan tekanan dan suhu tetap: GH - TS.
The various types of equilibriums are achieved as follows: Two systems are in thermal equilibrium when their temperatures are the same.
Jenis lain dari kesetimbangan yang dicapai adalah sebagai berikut: Dua sistem dalam kesetimbangan termal saat suhu sama.
Two systems are in mechanical equilibrium when their pressures are the same.
Dua sistem dalam kesetimbangan mekanik saat tekanan mereka sama.
It can be useful to distinguish between global and local thermodynamic equilibrium.
Adalah penting untuk membedakan antara kesetimbangan termodinamika global dan lokal.
As an example, temperature controls heat exchanges.
Sebagai contoh, suhu mengontrol perubahan panas.
In a radiating gas, the photons being emitted and absorbed by the gas do not need to be in a thermodynamic equilibrium with each other or with the massive particles of the gas for LTE to exist.
Dalam gas yang memancar, foton-foton yang sedang dipancarkan dan diserap oleh gas tidak perlu berada dalam kesetimbangan termodinamika dengan masing-masing atau dengan partikel-partikel besar dari gas agar kesetimbangan termodinamika lokal ada.
If energies of the molecules located near a given point are observed, they will be distributed according to the Maxwell–Boltzmann distribution for a certain temperature.
Jika energi molekul ditempatkan dekat suatu titik yang diberi diobservasi, mereka akan didistribusikan menurut distribusi Maxwell-Boltzmann untuk suhu tertentu.
If the energies of the molecules located near another point are observed, they will be distributed according to the Maxwell–Boltzmann distribution for another temperature.
Jika energi-energi molekul didetempatkan ekat titik yang lain diamati, mereka akan didistribusikan menutur distribusi Maxwell-Boltzman untuk temperatur lainnya.
In other words, each small locality need not have a constant temperature.
Dengan kata lain, masing-masing lokalitas kecil tidak membutuhkan suhu yang tetap.
However, it does require that each small locality change slowly enough to practically sustain its local Maxwell–Boltzmann distribution of molecular velocities.
Tetapi, dia memerlukan masing-masing perubahan lokalitas kecil secara perlahan untuk menopang dengan praktis distribusi Maxwell-Boltzman lokal kecepatan molekul.
Natural transport phenomena may lead a system from local to global thermodynamic equilibrium.
Fenomena transport adalah proses yang mengatur bentuk sistem kesetimbangan termodinamika lokal ke global.
Going back to our example, the diffusion of heat will lead our glass of water toward global thermodynamic equilibrium, a state in which the temperature of the glass is completely homogeneous.
Kembali lagi pada contoh, difusi panas akan mengatur gelas terhadap kesetimbangan termodinamika, suatu keadaan dengan suhu gelas homogen sempurna.
Thermal equilibrium is achieved when two systems in thermal contact with each other cease to have a net exchange of energy.
Kesetimbangan termal dicapai ketika dua sistem dalam termal kontak dengan masing-masing berhenti untuk memperoleh net perubahan energi.
It follows that if two systems are in thermal equilibrium, then their temperatures are the same.
Ini berarti bahwa jika dua sistem dalam kesetimbangan termal, suhu mereka sama.
For example, an ideal gas whose distribution function has stabilised to a specific Maxwell–Boltzmann distribution would be in thermal equilibrium.
Contohnya, suatu gas ideal dengan fungsi distribusi telah stabil pada suatu distribusi Maxwell-Boltzmann dalam kesetimbangan termal.
Most systems found in nature are not in thermodynamic equilibrium because they are changing or can be triggered to change over time, and are continuously and discontinuously subject to flux of matter and energy to and from other systems.
Kebanyakan sistem yang ditemukan di alam tidak dalam kesetimbangan termodinamika karena mereka berubah atau dipicu untuk berubah terhadap waktu, dan secara tetap dan tidak tetap subjek untuk fluks materi dan energi dan dari sistem lainnya.
The thermodynamic study of non-equilibrium systems requires more general concepts than are dealt with by equilibrium thermodynamics.
Studi termodinamika sistem tidak-setimbang memenuhi banyak konsep umum daripda termodinamika kesetimbangan.
Many natural systems still today remain beyond the scope of currently known macroscopic thermodynamic methods.
Banyak sistem alam sampai sekarang tetap berada di luar cakupan metode termodinamika makroskopik sekarang ini.
United States Environmental Protection Agency Office of Research and Development, Washington, D.C.
United States Environmental Protection Agency Office of Research and Development, Washington DC
[1] Cesare Barbieri (2007) Fundamentals of Astronomy.
Cesare Barbieri (2007) Fundamentals of Astronomy.
Breakdown of Local Thermodynamic Equilibrium George W. Collins, The Fundamentals of Stellar Astrophysics, Chapter 15 Local Thermodynamic Equilibrium Non-Local Thermodynamic Equilibrium in Cloudy Planetary Atmospheres Paper by R. E. Samueison quantifying the effects due to non-LTE in an atmosphere Thermodynamic Equilibrium, Local and otherwise lecture by Michael Richmond
[1] F. Mandl (1988) Statistical Physics, Second Edition, John Wiley & Sons Breakdown of Local Thermodynamic Equilibrium George W. Collins, The Fundamentals of Stellar Astrophysics, Chapter 15 Thermodynamic Equilibrium, Local and otherwise lecture by Michael Richmond Non-Local Thermodynamic Equilibrium in Cloudy Planetary Atmospheres Paper by R. E. Samueison quantifying the effects due to non-LTE in a atmosphere Local Thermodynamic Equilibrium Xchanger Inc, webpage Diarsipkan 2012-03-06 di Wayback Machine.