Non-equilibrium surface heating

Non-Equilibrium Surface Heating and Evaporation Effect In Heterogeneous Plasma-Chemical Processes in Non-Thermal Discharges... 

Non-Equilibrium Surface Heating and Evaporation in Plasma Treatment of Thin Layers of Flat Surfaces Effect of Short Pulses... 

Non-Equilibrium Surface Heating in Plasma Treatment of Thin Layers. Based on (7-16)-(7-18), derive formula (7-19) for the heat flux Qo required to provide a temperature... 

An unusual dependence for adsorption on a uniform surface arises when it is assumed that the rate of change of the surface is considerably slower than the rate of adsorption (see figure). If adsorption and desorption occur rapidly, the state of the surface remains practically unaltered and we then get an adsorption isotherm corresponding to a non-uniform surface with a distribution p(E, 0) of the heat of adsorption (curve 1) [3]. However, when the time interval is considerable, slow adsorption accompanies changes in the properties of the surface, and the amount of gas adsorbed approaches that given by the Langmuir isotherm (curve 2, point B), which describes a state of complete equilibrium (see above). 

The processes of scattering and absorption of radiation in the atmosphere so significantly alter the spectral distribution that any similarity to extra terrestrial radiation is almost coincidental. Experiments with radiation between surfaces have shown that blackbody radiation theory can be extended successfully to many radiation heat transfer situations. In these situations the strict equilibrium requirements of the initial model have so far not proved to be necessary for practical designs. Most importantly the concept of temperature has proved useful in non-equilibrium radiation flux situations(3). 

Hydrogen reduction of oxides as well as gasification reactions, solid-state synthesis, and surface treatment processes can be focused on a thin layer of a flat surface and stimulated by non-thermal plasma (Te > To). Similar to the powder-related cold plasma processes, thin-layer processes in cold gas can also be limited by surface temperature. Again, VT nonequilibrium (Te > Tv > To) in this case can provide surface temperatures (Tg) significantly exceeding the gas temperatme (To), because surface VT relaxation is much faster than that in the gas phase. The non-equilibrium heating of a thin layer can be accomplished by... 

Relations (7-16)-(7-18) demonstrate that heating of a thin layer by short non-thermal discharge pulses provides significant local temperature increase in a thin surface layer without heating up the whole system. The gas temperature also remains low because of the application of strongly non-equilibrium discharges (Te > Tv > To). Based on relations (7-16)-(7-18) the heat flux go (7-13) required to provide a temperature increase AT in a layer with thickness h can be found as... 

In summary, the process occurring in the early-time domain is regarded to be non-equilibrium. When the IR laser illuminates a surface of the liquid beam, C6H4(0H)2(H20), (m 0) is released from it by a compression wave caused by vibrational excitation of solvent molecules before the establishment of thermal equilibrium. As a result, a solute molecule embedded in a cold solvent cluster is isolated in the gas phase at a super thermal velocity of 1300 m s In the late-time domain, only a bare solute molecule having a thermal velocity of 400 m s is present because solute molecules are isolated after the evaporation of solvent by the IR-laser heating. 

A diffuse layer is observed at the surface of a crystal which is growing into the melt. The building up of this layer and the dynamics of entropy fluctuations have been studied by quasi elastic light scattering. Water and salol have been used as test substances. In a stationary non equilibrium steady state the layer is several thousand lattice constants thick. The diffusion constant, which determines the dynamics of the entropy fluctuations in this layer, is Dj 3 10 cm /s. It is isotropic in space. During freezing fluctuations in order can not be separated from fluctuation of heat. Therefore we interpret D as J. Frenkel s constant of "structure diffusion". 

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