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Full-Text Articles in Physics
Dynamically Maintained Steady-State Pressure Gradients, D. P. Sheehan
Dynamically Maintained Steady-State Pressure Gradients, D. P. Sheehan
Physics and Biophysics: Faculty Scholarship
In a sealed blackbody cavity with gas, pressure gradients commonly take three forms: (a) statistical fluctuations, (b) transients associated with the system relaxing toward equilibrium, and (c)equilibrium pressure gradients associated with potential gradients (such as with gravity). In this paper, it is shown that in the low-density (collisionless) regime, a fourth type of pressure gradient may arise, this due to steady-state differential thermal desorption of surface species from chemically active surfaces. This gas phase is inherently nonequilibrium in character. Numerical simulations using realistic physical parameters support the possibility of this gas phase and indicate that these novel pressure gradients might …
Four Paradoxes Involving The Second Law Of Thermodynamics, D. P. Sheehan
Four Paradoxes Involving The Second Law Of Thermodynamics, D. P. Sheehan
Physics and Biophysics: Faculty Scholarship
Recently four independent paradoxes have been proposed which appear to challenge the second law of thermodynamics [1-8]. These paradoxes are briefly reviewed. It is shown that each paradox results from a synergism of two broken symmetries - one geometric, one thermodynamic