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Full-Text Articles in Physics
Mechanisms Of Methane Transport Through Populus Trichocarpa, Ellynne Marie Kutschera, M. A. K. Khalil, Andrew Rice, Todd Rosenstiel
Mechanisms Of Methane Transport Through Populus Trichocarpa, Ellynne Marie Kutschera, M. A. K. Khalil, Andrew Rice, Todd Rosenstiel
Physics Faculty Publications and Presentations
Although the dynamics of methane (CH4) emission from croplands and wetlands have been fairly well investigated, the contribution of trees to global CH4 emission and the mechanisms of tree transport are relatively unknown. CH4 emissions from the common wetland tree species Populus trichocarpa (black cottonwood) native to the Pacific Northwest were measured under hydroponic conditions in order to separate plant transport mechanisms from the influence of soil processes. Roots were exposed to CH4 enriched water and canopy emissions of CH4 were measured. The average flux for 34 trials (at temperatures ranging from 17 to 25 °C) was 2.8 ± 2.2 …
Single-Particle Model For A Granular Ratchet, Albert J. Bae, Welles Antonio Martinez Morgado, J. J. P. Veerman, Giovani L. Vasconcelos
Single-Particle Model For A Granular Ratchet, Albert J. Bae, Welles Antonio Martinez Morgado, J. J. P. Veerman, Giovani L. Vasconcelos
Mathematics and Statistics Faculty Publications and Presentations
A simple model for a granular ratchet corresponding to a single grain bouncing off a vertically vibrating sawtooth-shaped base is studied. Depending on the model parameters, horizontal transport is observed in both the preferred and unfavoured directions. A phase diagram is presented indicating the regions in parameter space where the different regimes (no current, normal current, and current reversal) occur.
Partial Chemical Equilibrium In Fluid Dynamics, John D. Ramshaw
Partial Chemical Equilibrium In Fluid Dynamics, John D. Ramshaw
Physics Faculty Publications and Presentations
An analysis is given for the flow of a multicomponent fluid in which an arbitrary number of chemical reactions may occur, some of which are in equilibrium while the others proceed kinetically. The primitive equations describing this situation are inconvenient to use because the progress rates ω [subscript s] for the equilibrium reactions are determined implicitly by the associated equilibrium constraint conditions. Two alternative equivalent equation systems that are more pleasant to deal with are derived. In the first system, the ω [subscript s] are eliminated by replacing the transport equations for the chemical species involved in the equilibrium reactions …
Hot Electron Injection Into Dense Argon, Nitrogen, And Hydrogen, Pavel Smejtek, M. Silver, K. S. Dy, David G. Onn
Hot Electron Injection Into Dense Argon, Nitrogen, And Hydrogen, Pavel Smejtek, M. Silver, K. S. Dy, David G. Onn
Physics Faculty Publications and Presentations
Hot electrons have been injected into very dense argon, nitrogen, and hydrogen gases and liquids. The current‐voltage characteristics are experimentally determined for densities (N) of argon, nitrogen, and hydrogen ranging from about 10²⁰ to 10²² cm⁻³ and applied fields (E) ranging from about 10 to 10⁴ V cm⁻¹. The argon data show a square root E∕N dependence of the current. The nitrogen and hydrogen data show a complicated dependence of the current on E∕N due to the rapid thermalization in the region of the image potential of the injected electrons through inelastic collision processes not present in argon. A hydrodynamic‐two‐fluid …