Physical Sciences and Mathematics Commons^™

Space Weather & Gps Reliant Industries, Jennifer L. Meehan, W. Murtagh

All Physics Faculty Publications

No abstract provided.

Unified Model Of Charge Transport In Insulating Polymeric Materials, Alec Sim, John R. Dennison

All Physics Faculty Publications

We present a preliminary report on the theoretical and experimental study of transport models in highly insulating materials. The report is developed in four sections; first we give background on the nature of the problems in space craft charging, the contributions and connections made by the Utah State material physics group. Second we discuss the density of states to explore the connections between material composition and the microscopic and macroscopic transport equations. Third from Maxwell’s equations we present an overview of the transport equations. Finally we present preliminary results using experimental data on Kapton^TM, the transport equations and …

Methods To Determine Total Electron-Induced Electron Yields Over Broad Range Ofconductive And Nonconductive Materials, Ryan C. Hoffmann, John R. Dennison

All Physics Faculty Publications

The electron emission properties of a material subject to incident radiation flux are key parameters in determining to what equilibrium charge a spacecraft will established under given environmental conditions. However, there is a complex relation between these emission properties and the charge built up in spacecraft insulators. Complex modeling codes have been developed to predict the potential a spacecraft will adopt as a consequence of its interaction with the space plasma. These require correct models of the electron yields as a function of charge to accurately predict the both the charge build up and the equilibrium potential of spacecraft components. …

Charge Dynamics In Highly Insulating Space Craft Materials, Alec Sim, John R. Dennison

All Physics Faculty Publications

We present a preliminary report on the theoretical and experimental study of transport models in highly insulating materials. The report is developed in four sections; first we give background on the nature of the problems in space craft charging, the contributions and connections made by the Utah State material physics group. Second we discuss the density of states to explore the connections between material composition and the microscopic and macroscopic transport equations. Third from Maxwell’s equations we present an overview of the transport equations. Finally we present preliminary results using experimental data on KaptonTM, the transport equations and relevant expressions …

Space Weather & Gps Reliant Industries, Jennifer L. Meehan, W. Murtagh

All Physics Faculty Publications

No abstract provided.

Measurement Methods Of Electron Emission Over A Full Range Of Sample Charging, R. C. Hoffman, John R. Dennison

All Physics Faculty Publications

The electron emission properties of a material subject to incident radiation flux are key parameters in determining to what equilibrium charge a spacecraft will established under given environmental conditions. However, there is a complex relation between these emission properties and the charge built up in spacecraft insulators. Complex modeling codes have been developed to predict the potential a spacecraft will adopt as a consequence of its interaction with the space plasma. These require correct models of the electron yields as a function of charge to accurately predict the both the charge build up and the equilibrium potential of spacecraft components. …

A Global Climatology Of The Mesospheric Sodium Layerfrom Gomos Data During The 2002-2008 Period, D. F. Fussen, F. Vanhellemont, C. T'Etart, N. Mateshvili, E. Dekemper, N. Loodts, C. Bingen, E. Kyrola, J. Tamminen, V. Sofieva, A. Hauchecorne, F. Dalaudier, J. L. Bertaux, G. Barrot, L. Blanot, O. Fanton D'Andon, T. Fehr, L. Saavedra, Tao Yuan, C. Y. She

All Physics Faculty Publications

This paper presents a climatology of the mesospheric sodium layer built from the processing of 7 years of GOMOS data. With respect to preliminary results already published for the year 2003, a more careful analysis was applied to the averaging of occultations inside the climatological bins (10° in latitude-1 month). Also, the slant path absorption lines of the Na doublet around 589 nm shows evidence of partial saturation that was responsible for an underestimation of the Na concentration in our previous results. The sodium climatology has been validated with respect to the Fort Collins lidar measurements and, to a lesser …

Comparison Of Flight And Ground Tests Of Environmental Degradation Of Misse-6 Suspecs Materials, Jr Dennison, John Prebola, Amberly Evans, Danielle Fullmer, Joshua L. Hodges, Dustin H. Crider, Daniel S. Crews

Conference Proceedings

The effects of prolonged exposure to the LEO space environment and charge-enhanced contamination on optical, thermal, and electron emission and transport properties of common spacecraft materials have been investigated by comparing pre- and post-flight characterization measurements. The State of Utah Space Environment and Contamination Study (SUSpECS) deployed in March 2008 on board the Materials International Space Station Experiment (MISSE-6) payload, was exposed for ~18 months on the exterior of the International Space Station (ISS), and was retrieved in September 2009. A total of 165 samples were mounted on three separate SUSpECS panels on the ram and wake sides on the …

Utah Climate And Water Report, U.S. Natural Resources Conservation Service

Water

Provides a snapshot of current and immediate past climatic conditions and other information useful to agricultural and water user interests in Utah.

The Sagebrush Steppe Treatment Evaluation Project (Sagestep): A Test Of State-And Transition Theory., J. D. Mciver, Mark W. Brunson, S. Buntin, J. Chambers, N. Devoe, P. Doescher, J. Grace, D. Johnson, S. Knick, R. Miller

Environment and Society Faculty Publications

No abstract provided.

Action Research, Knowledge & Impact: Experiences Of The Global Livestock Crsp Pastoral Risk Management Project In The Southern Ethiopian Rangelands, D. Layne Coppock

Environment and Society Faculty Publications

No abstract provided.

Funboe (Follow-Up Nucleate Boiling On-Flight Experiment), Getaway Special Team 2010

Education and Outreach

No abstract provided.

The Gas Team And Nasa (Aka Boil, Boil, Toil And Trouble), Get Away Special Team 2010

Education and Outreach

No abstract provided.

Gravitational Effects On Thin-Wire Subcooled Nucleate Boiling Dynamics, Justin Koeln, Andrew Fassmann, Troy Munro, Rob Barnett

Education and Outreach

No abstract provided.

Gravitational Effects On Thin-Wire Subcooled Nucleate Boiling Dynamics, Justin Koeln, Andrew Fassmann, Troy Munro, Rob Barnett

Presentations

No abstract provided.

Geophysical Properties Within The San Andreas Fault Zone At The San Andreas Fault Observatory At Depth (Safod) And Their Relationships To Rock Properties And Fault Zone Structure, Tamara N. Jeppson, Kelly Keighley Bradbury, James P. Evans

Geosciences Faculty Publications

We examine the relationships between borehole geophysical data and physical properties of fault‐related rocks within the San Andreas Fault as determined from data from the San Andreas Fault Observatory at Depth borehole. Geophysical logs, cuttings data, and drilling data from the region 3‐ to 4‐km measured depth of the borehole encompass the active part of the San Andreas Fault. The fault zone lies in a sequence of deformed sandstones, siltstone, shale, serpentinite‐bearing block‐in‐matrix rocks, and sheared phyllitic siltstone. The borehole geophysical logs reveal the presence of a low‐velocity zone from 3190 to 3410 m measured depth with V_p and …

Composition And Structure Of The San Andreas Fault Observatory At Depth (Safod) Phase Iii Whole-Rock Core: Implications For Fault Zone Deformation And Fluid-Rock Interactions, Kelly Keighley Bradbury, James P. Evans

Geosciences Presentations

We examine the composition and texture of whole-rock core from ~ 3 km depth in the San Andreas Fault Observatory at Depth (SAFOD) borehole, which provides a unique opportunity to characterize in situ rock properties of the near-fault environment, and how these properties vary in an area where deformation is accommodated by aseismic creep and high-rates of microseismicity. Detailed petrography and microstructural analyses coupled with X-Ray Diffraction and X-ray Fluorescence techniques are used to describe composition, alteration, and textures.

All samples record multiple generations of cataclastic deformation in a complexly deformed and altered sequence of fine-grained sheared rocks. Localized shears …

Environmental Assessment: Adobe Town-Salt Wells Creek Herd Management Area Complex Wild Horse Gather, U.S. Bureau Of Land Management

Environmental Assessments (WY)

To analyze the environmental effects of wild horse gather operations and potential population control methods (including fertility control treatment and sex ration adjustment) in order to achieve and maintain the established appropriate management levels for the Adobe Town and Salt Wells Creek Herd Management Areas.

Duskside F-Region Dynamo Currents: Itsrelationship With Prereversal Enhancement Of Vertical Plasma Drift, P. Park, H. Luhr, Bela G. Fejer, K. W. Mim

Bela G. Fejer

From magnetic field observations by CHAMP we estimate F-region dynamo current densities near the sunset terminator during solar maximum years from 2001 to 2002. The dynamo currents are compared with the pre-reversal enhancement (PRE) of vertical plasma drift as observed by ROCSAT-1. The seasonal-longitudinal variation of PRE can be largely related to the F-region dynamo current density, with the correlation coefficient reaching 0.74. The correlation can be further improved if we consider a zonal gradient of the E-region Pedersen conductivity, which also depends on season and longitude. It is widely accepted that the Fregion dynamo drives PRE near sunset. For …

Temperature Trends And Episodic Changes Of The Middle Atmosphere Over Logan Utah With Consideration To Model Specification, Troy A. Wynn, Vincent B. Wickwar

Reports

A summary of the linear trends estimated from the USU Rayleigh Lidar (41.74o N, 118oW) temperature data set. The data set covers a time span from September, 1993 to August, 2003 and an altitude range of 45 to 80 km. The data set includes 584 data points at 45 km to 580 data points at 80 km. Cooling trend profiles are calculated and compared to results from other researchers. Collinearity and bias are also considered as issues that could affect the regression results. Also considered is the possibility that the Mt. Pinatubo eruption has influenced temperature trend estimates. This is …

Landscape Assessment Of A Stable Aspen Community In Southern Utah, Usa, Paul C. Rogers, A. Joshua Leffler, R. Ryel

Wildland Resources Faculty Publications

Recent reports of rapid die-off of aspen (Populus tremuloides), coupled with vigorous debate over longterm reduction of aspen cover in western North America, has prompted considerable research given the importance of this forest type for economic and non-economic interests. Despite this interest, indicators of aspen conditions are poorly understood, and there is a lack of systematic monitoring of stable aspen landscapes. Stable aspen are defined here as being predominantly aspen overstorey (>80% basal area) with little or no conifer regeneration. We examined a putative stable aspen landscape in southern Utah and addressed (1) stand structure and (2) indicators of …

A Comparison Of Soil Moisture And Hillslope-Stream Connectivity Between Aspen And Conifer-Dominated Hillslopes Of A First Order Catchment In Northern Utah, Amy R. Burke

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mountain headwater catchments in the semi-arid Intermountain West are important sources of surface water because these high elevations receive more precipitation than neighboring lowlands. The hydrology of these mountain catchments is especially important as the region faces water shortages and conflicts. Conifer encroachment on aspen stands has been observed across the western US and can result in a decline in water yield. The overall objective of this study was to further our understanding of hillslope-stream connectivity in a headwater catchment of Northern Utah and any observable differences in this connection between aspen and conifer hillslopes. Hillslopes are the fundamental unit …

A Comparison Theorem For The Topological And Algebraic Classification Of Quaternionic Toric 8-Manifolds, Piotr Runge

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In order to discuss topological properties of quaternionic toric 8-manifolds, we introduce the notion of an algebraic morphism in the category of toric spaces. We show that the classification of quaternionic toric 8-manifolds with respect to an algebraic isomorphism is finer than the oriented topological classification. We construct infinite families of quaternionic toric 8-manifolds in the same oriented homeomorphism type but algebraically distinct. To prove that the elements within each family are of the same oriented homeomorphism type, and that we have representatives of all such types of a quaternionic toric 8-manifold, we present and use a method of evaluating …

Geologic Mapping, Alluvial Stratigraphy, And Optically Stimulated Luminescence Dating Of The Kanab Creek Area, Southern Utah, Michelle Carlene Summa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

At the turn of the century, Kanab Creek incised 30-meters into its alluvium, leaving behind fluvial terraces and thick basin fill sediments exposed along arroyo walls. Research objectives were to determine the timing and causes of past valley-filling and arroyo-cutting episodes along a 20 km-long reach of Kanab Creek in southern Utah. Fluvial deposits were mapped at the 1:12,000 scale and sediments were described and dated using Optically Stimulated Luminescence (OSL) and radiocarbon dating.

The Kanab Creek valley can be divided into a narrow, upper terraced reach and a broad lower basin fill reach near Kanab, Utah. The most prominent …

Eleven Years Of Parima Activities In North-Central Kenya: Impacts On Egerton University And Neighboring Communities, D. Layne Coppock, Abdillahi Aboud, Mark Mutinda, Stellamaris Muthoka

Environment and Society Faculty Publications

The PARIMA project was created to improve the well-being of pastoralists and agro-pastoralists in northern Kenya and southern Ethiopia via risk-management research, training, and outreach. The project began to collaborate with Egerton University’s Department of Natural Resources in 1998 and many joint activities were undertaken over the next 11 years. Among them were regional household research on pastoral risks and their management, a training program for Egerton teaching staff to obtain post-graduate degrees, facilitation of Egerton faculty and staff to attend professional meetings, and provision of computer hardware and software that led to the creation of a GIS teaching and …

Costs Of Implementing Collective Action And Capacity Building Among Pastoralists In Southern Ethiopia, D. Layne Coppock, Seyoum Tezera, Solomon Desta

Environment and Society Faculty Publications

Since 2000, the PARIMA project has implemented risk-management activities among semi-settled pastoralists in southern Ethiopia. The goal has been to improve human welfare via collective action and capacity building. Outcomes include progress in income generation, asset conservation, and livelihood diversification. Fifty-nine collective-action groups were created. Dominated by women, they included over 2,000 founding members and groups have recently merged to form 37 cooperatives, consistent with government policy. Creating sustainable impacts via collective action and capacity building requires many inputs. Taking raw, illiterate volunteers and transforming them into sustainable groups took up to three years, on average. Costs of implementing this …

Can Pastoral Linkages To Livestock Markets Be Sustained In Southern Ethiopia?, D. Layne Coppock, Getachew Gebru, Solomon Desta, Seyoum Tezera, Zewdu Edea

Environment and Society Faculty Publications

The PARIMA project has facilitated collective action, empowerment of women, and increased involvement in livestock marketing among pastoralists on the Borana Plateau since 2001. Fifty-nine collective-action groups formed by PARIMA and her partners have been recently merged into market-oriented cooperatives, consistent with government policy. We used focus groups and participatory appraisals to assess the extent that market linkages have been sustained since previously reported in 2006. The markets have been growing, but are volatile. Members report they need access to early warning and livestock market-information systems, as well as more capital, to promote trade. Export firms have imposed added conditions …

Salinity Inventory And Tolerance Screening In Utah Agriculture, Austin Mccoy Hawks

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Soil salinity, a yield-limiting condition, has plagued crop production for centuries by reducing crop productivity. Research has introduced methods for successfully managing soil salinity. This research discusses the adaptation of established management methods to create new soil salinity management techniques.

One adapted technique is an automated crop screening apparatus. A new design was created and successfully used in rapidly screening two strawberry cultivars to determine their tolerance to salinity. Screening crops and determining their tolerance to yield-limiting conditions are essential in managing soil salinity.

Another salinity management tool used in this research was electromagnetic induction (EMI). EMI was used to …

Alternative Sampling And Analysis Methods For Digital Soil Mapping In Southwestern Utah, Colby W. Brungard

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Digital soil mapping (DSM) relies on quantitative relationships between easily measured environmental covariates and field and laboratory data. We applied innovative sampling and inference techniques to predict the distribution of soil properties, soil attributes, taxonomic classes, and dominant vegetation across a 30,000-ha complex Great Basin landscape in southwestern Utah. This arid rangeland was characterized by rugged topography, diverse vegetation, and intricate geology. Environmental covariates calculated from digital elevation models (DEM) and spectral satellite data were used to represent factors controlling soil development and distribution. We investigated optimal sample size and sampled the environmental covariates using conditioned Latin Hypercube Sampling (cLHS). …

Geometry And Electronic Structure Of Doped Clusters Via The Coalescence Kick Method, Boris Averkiev

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Developing chemical bonding models in clusters is one of the most challenging tasks of modern theoretical chemistry. There are two reasons for this. The first one is that clusters are relatively new objects in chemistry and have been extensively studied since the middle of the 20th century. The second reason is that clusters require high-level quantum-chemical calculations; while for many classical molecules their geometry and properties can be reasonably predicted by simpler methods.

The aim of this dissertation was to study doped clusters and explain their chemical bonding. The research was focused on three classes of compounds: aluminum clusters doped …