Chemical potential thermal radiation

Thermal radiation may be characterized as a photon gas, consisting of zero-mass bosons with zero chemical potential. Without proof, the photon number density may be written [6, Sect. 2.3],... 

Energy Capacity to do work can be chemical, electrical, heat, kinetic, nuclear, potential, radiant, radiation, or thermal in nature. 

A hazard is a potential source of bodify damage. Hazards m be classified in terms of the type of energy that they deliver - i.e. mechanical, thermal, electrical, chemical or ionizing radiation - or in terms of the energy exchange which they interrupt i.e. thermal balance or oxygen utilization. 

The above expression for entropy and the equations of state (11.2.6) and (11.2.7) are basic all other thermodynamic quantities for thermal radiation can be obtained from them. Unlike other thermodynamic systems we have studied so far, the temperature T is sufficient to specify all the thermodynamic quantities for thermal radiation the energy density u T), the entropy density s T) = S T)/V and all other thermodynamic quantities are entirely determined by T. There is no term involving a chemical potential in the expressions for S or U. If we consider the particle nature of thermal radiation, i.e. a gas of photons, the chemical potential must be assumed to equal zero — as we shall see in section 11.5. 

With the above observations that the chemical potential of thermal radiation is zero, the interaction of a two-level atom with blackbody radiation (which Einstein used to obtain the ratio of the rates of spontaneous and stimulated radiation) can be analyzed in a somewhat different light. If A and A are the two states of the atom, and y is a thermal photon, then the spontaneous and stimulated emission of radiation can be written as... 

When we consider interconversion of particles and radiation, as in the case of particle-antiparticle pair creation and annihilation, the chemical potential of thermal photons becomes more significant (Fig. 11.4). Consider thermal photons in equilibrium with electron-positron pairs ... 

The technique can be applied to all systems, which contain, make use of, or which store energy in any form or forms, (e.g. potential, kinetic mechanical energy, electrical energy, ionising or non-ionising radiation, chemical, and thermal) (Tarrents, 1980). 

At present, thermal catalysis induced by solar radiation is more ready for potential practical use in the energy production industry of the future, than photocatalysis [7,9,29,30], Fig.7 illustrates the scheme of the pilot plant for thermocatalytic solar-to-chemical energy... 

Most radiation-chemical reactions are thermal in nature those considered in the diffusion-kinetic scheme are essentially thermal reactions (see Chapter 7). In polar media, electron thermalization is presumed to occur before solvation (Mozumder, 1988). However, ionization processes usually involve transfer of energy in excess of the ionization potential (see Chapter 4). Therefore, mechanisms of thermalization are important for radiation-chemical effects. 

ESEC s hybrid photo/thermo-chemical water splitting cycle employs the quantum portion of the solar spectrum for the production of H2 and the thermal portion i.e., IR) portion of solar radiation for O2 evolution [5,20]. Utilization of the fuU solar spectrum ahows the cycle to reach potentially a higher overall... 

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