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Full-Text Articles in Engineering
Lunar Lava Tube Radiation Safety Analysis, Giovanni De Angelis, J. W. Wilson, M. S. Clowdsley, J. E. Nealy, D. H. Humes, J. M. Clem
Lunar Lava Tube Radiation Safety Analysis, Giovanni De Angelis, J. W. Wilson, M. S. Clowdsley, J. E. Nealy, D. H. Humes, J. M. Clem
Mathematics & Statistics Faculty Publications
For many years it has been suggested that lava tubes on the Moon could provide an ideal location for a manned lunar base, by providing shelter from various natural hazards, such as cosmic radiation, meteorites, micrometeoroids, and impact crater ejecta, and also providing a natural environmental control, with a nearly constant temperature, unlike that of the lunar surface showing extreme variation in its diurnal cycle. An analysis of radiation safety issues on lunar lava tubes has been performed by considering radiation from galactic cosmic rays (GCR) and Solar Particle Events (SPE) interacting with the lunar surface, modeled as a regolith …
Validation Of A Finite-Element Stored Grain Ecosystem Model, Michael D. Montross, Dirk E. Maier, Kamyar Haghighi
Validation Of A Finite-Element Stored Grain Ecosystem Model, Michael D. Montross, Dirk E. Maier, Kamyar Haghighi
Biosystems and Agricultural Engineering Faculty Publications
An axisymmetric finite–element model was validated with respect to predicting the heat, mass, and momentum transfer that occurred in upright corrugated–steel storage bins due to conduction, diffusion, and natural convection using realistic boundary conditions. Hourly weather data that included hourly total solar radiation, wind speed, ambient temperature, and relative humidity were used to model the corn temperature and moisture content during storage with no aeration, and with ambient and chilled aeration. Periods of aeration were simulated assuming a uniform airflow rate through the grain mass. Sixteen bins with a capacity of 11.7 t each and instrumented with temperature cables were …
Models Of Soil Moisture Dynamics In Ecohydrology: A Comparative Study, Andrew J. Guswa, M. A. Celia, I. Rodriguez-Iturbe
Models Of Soil Moisture Dynamics In Ecohydrology: A Comparative Study, Andrew J. Guswa, M. A. Celia, I. Rodriguez-Iturbe
Engineering: Faculty Publications
An accurate description of plant ecology requires an understanding of the interplay between precipitation, infiltration, and evapotranspiration. A simple model for soil moisture dynamics, which does not resolve spatial variations in saturation, facilitates analytical expressions of soil and plant behavior as functions of climate, soil, and vegetation characteristics. Proper application of such a model requires knowledge of the conditions under which the underlying simplifications are appropriate. To address this issue, we compare predictions of evapotranspiration and root zone saturation over a growing season from a simple bucket-filling model to those from a more complex, vertically resolved model. Dimensionless groups of …
Development Of A Finite-Element Stored Grain Ecosystem Model, Michael D. Montross, Dirk E. Maier, Kamyar Haghighi
Development Of A Finite-Element Stored Grain Ecosystem Model, Michael D. Montross, Dirk E. Maier, Kamyar Haghighi
Biosystems and Agricultural Engineering Faculty Publications
An axisymmetric finite–element model was developed that predicts the heat, mass, and momentum transfer that occurred in upright corrugated steel storage structures due to conduction, diffusion, and natural convection using realistic boundary conditions. Weather data that included hourly total solar radiation, wind speed, ambient temperature, and relative humidity were used to model the temperature, moisture content, dry matter loss, and maize weevil development during storage with no aeration, and with ambient and chilled aeration. Periods of aeration were simulated assuming a uniform airflow rate through the grain mass. Heat and mass balances were used to calculate the temperature and absolute …
On Using The Equivalent Conductivity To Characterize Solute Spreading In Environments With Low-Permeability Lenses, Andrew J. Guswa, David L. Freyberg
On Using The Equivalent Conductivity To Characterize Solute Spreading In Environments With Low-Permeability Lenses, Andrew J. Guswa, David L. Freyberg
Engineering: Faculty Publications
Solute transport through highly heterogeneous geologic environments with connected pathways through high-conductivity material and lenses of low permeability often is not described well by a macroscopic advection-dispersion equation. An upscaled advection-dispersion model with a uniform velocity and dispersion coefficient does not predict the significant plume asymmetry and extended tailing often observed over finite distances in such environments. We investigate the hydrogeologic conditions under which an upscaled model must incorporate another mechanism to describe the extended tailing arising from slow advection through and diffusion into and out of low-permeability inclusions. We use high-resolution simulations to determine ground truth transport results for …