Phonon Dispersion and Relaxation Time in Uranium Dioxide

Phonon dispersion branches are used to obtain an effective relaxation time to calculate thermal conductivity of Uranium Dioxide (UO2). The method presented closely follows that of Deskins’ phonon-phonon interaction that uses a three-phonon process which satisfies momentum and energy conservation. All phonon branches including longitudinal acoustic, transverse acoustic, longitudinal optical and transverse optical are considered in the calculation of the relaxation time. After one phonon is identified, a scan is initiated to test all phonon combinations that will satisfy the conservation equations. When the scan identifies a valid three-phonon combination a relaxation time is calculated for that combination. All the relaxation times from the possible combinations are summed using Mathias’ rule to obtain a total approximate relaxation time for that phonon. Thermal conductivity at equilibrium can be calculated at a specific temperature using the relaxation time approximation of the Boltzmann equation. This approximation uses specific heat, relaxation time, group velocity and the Bose-Einstein distribution. Eventually, the goal of this work is to apply the routine for calculating relaxation time from this work to a Monte Carlo simulation that will treat systems not in equilibrium

Isotope Investigation of Nitrate in Soils and Agricultural Drain Waters of the Lower Yakima Valley, Washington

Nitrate in the groundwater of the Lower Yakima Valley, Washington has long been known to frequently exceed the EPA maximum contaminant level standard for potable water (10 mg/L), adversely impacting communities with disadvantaged socio-economic status. In this research, nitrogen and oxygen isotopic signatures were determined for nitrate soil leachates and irrigation return flow collected in the Lower Yakima Valley, Washington and compared to previous isotopic studies of nitrate in Central Washington. δ15N, δ18O and Δ17O values are used to constrain sources of to groundwater. Isotope signatures for nitrate from soil leachate largely overlapped with the point cloud of data for nitrate in groundwater in a local EPA study. The groundwater nitrate was largely attributed to a mixture of manure and fertilizer. However, isotope signatures in this study also overlapped with isotopic values attributed to naturally occurring soil nitrate from a study at the nearby Hanford Site, Washington. A mass balance calculation based on Δ17O data suggests that there is a ~9% atmospheric contribution to nitrate in soil accumulations below caliche layers at several locations. This atmospheric input was consistent across multiple sites. We argue that the consistent atmospheric component implies the nitrate in these soil samples at depth appears to have a largely predominately non-anthropogenic origin, because a significant anthropogenic input would dilute and cause variation in this atmospheric signature. We suggest the flushing of naturally occurring soil nitrate to groundwater during land use conversion to irrigated agriculture may represent a previously overlooked, significant, nitrate input to shallow alluvial aquifers in this region

4-H Agricultural Systems Technology

4-H gives youth an opportunity to explore different career paths, learn and practice new skills, and experience what a career in agricultural systems technology might be like

4-H Agricultural Economics

4-H gives youth an opportunity to explore different career paths, learn and practice new skills, and experience what a career in agricultural economics might be like

4-H Agribusiness

4-H gives youth an opportunity to explore different career paths, learn and practice new skills, and experience what a career in agribusiness might be like

Magical Realism and the Space Between Spaces

Magical realism comes from Franz Roh, a german art historian and critic, who first used the term to describe the Post-Expressionism movement in visual art. His seminal writings and definitions on Post-Expressionism, then known as magical realism, were translated into Spanish and made available to Latin America in the mid twentieth century. Authors like Jorge Luis Borges and Gabriel Garcia Marquez adopted Roh\u27s writings and re-appropriated magical realism into literary art, and from there the new genre proliferated through the Latin American Boom and magical realism in literary fiction reached global recognition, inspiring authors across the world to take it up and continue the tradition into the present