Quantity

Symbol

Unit

Absorptivity (absorption coefficient)

alpha

–

Capacitance (entropy capacitance)

Kapa

Ct/K

Capacitance (molar)

kapa_m

Ct/(K·mole)

Capacitance (specific)

kapa

Ct/(K·kg)

Change of energy

∆W

J

Change of entropy

∆S

Ct = J/K

Conductance (entropy conductance)

G_S

Ct/(s·K)

Conductance (thermal conductance)

G_W = T·G_S

W/K

Conductivity (entropy conductivity)

k_S

Ct/(s·K·m)

Conductivity (thermal)

k = T·k_S

W/(K·m)

Emissivity (emission coefficient)

epsilon

–

Energy

W

J

Enthalpy

H

J

Enthalpy of fusion or evaporation (specific)

lambda

J/kg

Entropy

S

Ct (Carnot)
= J/K

Entropy capacitance at constant pressure

Kapa_p

Ct/K

Entropy capacitance at constant volume

Kapa_V

Ct/K

Energy current

I_W

J/s = W

Entropy current

I_S

Ct/s

Entropy current density

j_S

Ct/(s·m^2)

Entropy exchanged (entropy transferred)

S_e

Ct = J/K

Entropy of fusion or evaporation (molar)

lambda_Sm

Ct/mole

Entropy of fusion or evaporation (specific)

lambda_S

Ct/kg

Entropy transfer coefficient

h_S (U_S)

Ct/(s·K·m^2)

Heat current (current of thermal energy)

I_W_th = T·I_S

W

Heat transfer coefficienct

h = T·h_S

W/(K·m^2)

Peltier coefficient

alpha

Ct/C

Rate of change of energy

dW/dt

J/s = W

Rate of change of entropy

dS/dt

Ct/s

Reflectivity (reflection coefficient)

rho

–

Resistance (energy transfer resistance)

R_W

K/W

Resistance (entropy transfer resistance)

R_S

K·s/Ct

Seebeck coefficient

epsilon

V/K

Temperature

T

K (Kelvin)

Temperature coefficient of energy (specific)

   = specific heat at constant volume

c_V = T·kapa_V

J/(K·kg)

Temperature coefficient of enthalpy (specific)

   = specific heat at constant pressure

c_p = T·kapa_p

J/(K·kg)

Temperature difference

∆T

K

Temperature gradient

dT/dx

K/m

Time constant

tau

s

Transmissivity (transmission coefficient)

tau

–