Physical Sciences and Mathematics Commons^™

Measurement Of Conductivity And Charge Storage In Insulators Related To Spacecraft Charging, A. R. Frederickson, Jr Dennison

Conference Proceedings

Several methods have been combined to measure conductivity and charge storage in insulating spacecraft materials. In order to avoid insulator problems, the motions of conducting electrons and holes must prevent the development of large electric fields exceeding 1E5 V/cm, where problems occur in spacecraft insulators. Approximate knowledge of the electric fields is important. One must consider generation of mobile electrons and holes, their trapping, thermal de-trapping, mobility and recombination.

Classical methods to measure thin film insulator conductivity apply a constant voltage to two electrodes on the sample and measure the resulting current for tens of minutes. Under constant voltage, a …

Materials Characterization At Utah State University: Facilities And Knowledgebase Of Electronic Properties Of Materials Applicable To Spacecraft Charging, John R. Dennison, C. D. Thomson, J. T. Kite, V. V. Zavyalov, Jodie Corbridge

All Physics Faculty Publications

In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function …

Utilising Riometry To Observe Gravity Waves In The Sunlit Mesosphere, M. J. Jarvis, R. E. Hibbins, Michael J. Taylor, T. J. Rosenberg

All Physics Faculty Publications

The novel use of imaging riometers to observe mesospheric gravity waves is described. Imaging riometers respond to changes in the absorption of cosmic radio noise in the ionospheric D-region which enables them to detect the compression and rarefaction of the atmosphere at 90 km altitude generated by the passage of gravity waves. A considerable advantage of this method is that, unlike conventional techniques which rely on imaging faint optical emissions from the airglow layer at 87 km altitude, riometers remain operative under daylit, moonlit or cloudy conditions. This is particularly important for research into gravity wave forcing of mesospheric temperature …

National Environmental Compliance Handbook, United States Department Of Agriculture, Natural Resources Conservation Service

All U.S. Government Documents (Utah Regional Depository)

The National Environmental Compliance Handbook (NECH) provides guidance to Natural Resource Conservation Service (NRCS) officials about how to comply with Federal environmental requirements when delivering technical and financial assistance. The objectives of this Handbook are to: • Improve the quality of plans and decisions by integrating environmental considerations into the planning process; • Promote efficiency in preparing environmental documentation; • Provide a systematic framework for integrating the NRCS planning process and environmental requirements; and • Serve as a reference for NRCS environmental compliance procedures.

Long-Range Transportation Planning In Utah: Executive Summary, Dale Blahna, Joanna Endter-Wada, Steve Burr, Michael Butkus, Douglas Gibbons, Christina Klien, Judith Kurtzman, Douglas Reiter

Environment and Society Faculty Publications

This is the Executive Summary of the 2003 Utah Department of Transportation (UDOT) Benchmark Study. The study involved two phases and the USU research team produced two final reports, one for each phase of the research project, and an overarching Executive Summary. The purposes of the 2003 UDOT Benchmark Study conducted by Utah State University (USU) were to provide the Utah Department of Transportation (UDOT) with information for use in its statewide, long-range transportation plan and to provide benchmark data for tracking trends over time. The study was conducted jointly by the Institute for Outdoor Recreation and Tourism and the …

Long-Range Transportation Planning In Utah: Summary Of Research Results From Interviews And Focus Groups, Joanna Endter-Wada, Judith Kurtzman, Michael Butkus, Dale Blahna, Christina Klien, Steve Burr, Douglas Gibbons, Douglas Reiter

Environment and Society Faculty Publications

This is the final Report from Phase II of the 2003 Utah Department of Transportation (UDOT) Benchmark Study. The study involved two phases and the USU research team produced two final reports, one for each phase of the research project, and an overarching Executive Summary. The purposes of the 2003 UDOT Benchmark Study conducted by Utah State University (USU) were to provide the Utah Department of Transportation (UDOT) with information for use in its statewide, long-range transportation plan and to provide benchmark data for tracking trends over time. The study was conducted jointly by the Institute for Outdoor Recreation and …

Great Plains Workshop Held To Prepare For Usarray Deployment, Mary S. Hubbard, S. S. Gao, K. H. Liu, K. E. Nicolaysen, C. G. Oviatt

Geosciences Faculty Publications

Relative to most parts of North America, the Great Plains region, which is bordered by the Rocky Mountain Front on the west and the Mississippi River on the east, has been understudied in terms of the structure, formation, and evolution of the underlying crust, mantle, and core. The anticipated arrival of the USArray portable seismic stations, which will cover the entire United States regardless of surface geology and tectonic activities, and the deployment of the accompanying flexible array stations and the permanent seismic stations in this area, will fill this gap and address numerous problems related to the structure and …

Three-Dimensional Nonlinear Evolution Ofequatorial Ionospheric Spread-F Bubbles, M. J. Keskinen, S. L. Ossakow, Bela G. Fejer

Bela G. Fejer

[1] Using numerical simulation techniques, we present the first study of the three-dimensional nonlinear evolution of an equatorial spread-F bubble. The background ionosphere used to initialize the bubble evolution is computed using a time-dependent first-principles equatorial plasma fountain model together with a prereversal enhancement vertical drift model. We find that finite parallel conductivity effects slow down both the linear and nonlinear bubble evolution compared to the two-dimensional evolution. In addition we find that bubble-like structures with extremely sharp density gradients can be generated off the equator at equatorial anomaly latitudes in agreement with recent observations.

An Investigation Of Gravity Wave Activity In The Low-Latitude Mesosphere: Propagation Direction And Wind Filtering, A. F. Medeiros, Michael J. Taylor, H. Takahashi, P. P. Batista, D. Gobbi

All Physics Faculty Publications

An all-sky charge-coupled device imager capable of measuring wave structure in the OH, O2, and O I (557.7 nm) airglow emissions was operated at Cachoeira Paulista, Brazil (23S, 45W), for 2 years in collaboration with Utah State University, Logan. The dominant quasi-monochromatic gravity wave components investigated over a 1 year period (September 1998 to October 1999) have been extracted, and their seasonal variations have been measured. A total of 283 wave events were measured, exhibiting horizontal wavelengths from 5 to 60 km, observed periods from 5 to 35 min, and horizontal phase speeds of up to 80 m s1. The …

Validation Of Imaging Doppler Interferometer Winds Using Meteor Radar, G. O.L. Jones, C. S. Fish, W. K. Hocking, Michael J. Taylor

All Physics Faculty Publications

There has been some debate over the years concerning the accuracy of mesospheric wind observations made using the imaging Doppler interferometer (IDI) technique. The high potential and increasing use of IDI wind data in joint studies with spaced-antenna MF and meteor radar systems make it important to quantify the IDI results. This paper presents a novel comparison of wind measurements between a dynasonde implementation of IDI and winds derived from an all-sky meteor radar system, a widely-accepted standard for such measurements. Both radars were located at the USU Bear Lake Observatory and operated almost continuously for a four-month period. The …

Flow Recommendations To Benefit Endangered Fishes In The Colorado And Gunnison Rivers, Charles W. Mcada

All U.S. Government Documents (Utah Regional Depository)

No abstract provided.

Wildlife-Human Interactions In National Parks In Canada And The Usa, Dr. Alistair J. Bath, Jody W. Enck, National Park Service, U.S. Department Of The Interior

All U.S. Government Documents (Utah Regional Depository)

The chance to view wildlife draws millions of visitors each year to the national parks of North America. The combination of a large number of people and abundant wildlife leads to a variety of wildlife-human interactions. In this paper we explore the nature of those wildlife-human interactions, theoretical frameworks social scientists are using to understand those interactions, and approaches used by national parks across North America to manage those interactions.

Spacecraft Charging Research, Eric Crapo

Senior Theses and Projects

No abstract provided.

Finite Element Studies In Metal Cutting, Suhail Ahmed

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

AdvantEdge is a finite element software package that integrates advanced dynamics, thermo-mechanically coupled finite element numerics and material modelling appropriate for machining processes. AdvantEdge allows users to specify the workpiece material, tool geometry and cutting conditions. It then provides accurate estimates of thermo-mechanical properties of machining processes such as cutting forces, chip morphology, machined surface residual stresses and temperature behavior of the tool and the workpiece. We will use AdvantEclge to investigate two areas of interest in metal cutting: process clamping via crushing of workpiece material and drilling of metal stacks.

Test Suite For Multiobjective Optimization And Results Using Normal Boundary Intersection (Nbi) In Design Explorer, Siva Kumar Natarajan

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Several methods have been developed to solve multiobjective optimization problems (MOP's). One of these, Normal Boundary Intersection (NBI), is a method developed by John Dennis and Indraneel Das. NBI is used at The Boeing Company as a tool to solve MOP's. This report presents a test suite of MOP's that I developed for Boeing during me internship in summer 2003.

The problems in the test suite were chosen to represent the different types of multiobjective optimization problems that could arise in practice and the complexities involved in solving them. These problems range from those that have nice convex Pareto surfaces …

Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The ability to ensure uniformity of temperature within a given finite physical region is an essential element in the success of many scientific processes, especially those that involve extreme fluctuation in temperature. Such a process is performed in an instrument called the LightTyper developed by Idaho Technology, Inc. of Salt Lake City Utah. This paper details the development and results of a scheme intended to obtain a heating design that ensures a high degree of temperature uniformity within the Idaho Technology instrument. Due to the experiments performed during this project, we were able to answer many questions that concerned finding …

Predicting Mountain Pine Beetle Development With The Extended Von Foerster Model, Jeffrey Tullis Leek

Undergraduate Honors Capstone Projects

The mountain pine beetle (Dendroctonus ponderosae Hopkins) represents a significant threat to ponderosa pine and lodgepole pine stands in the western United States, and has the potential to threaten commercially valuable jack pine in both the United States and Canada. The success of the mountain pine beetle is based on synchronization of developmental events to time cold-hardened life stages for extreme winter temperatures and to facilitate mass attack and overwhelm the defenses of the host. This paper presents a solution methodology for an extended McKendrick - von Foerster model for the development of the mountain pine beetle in varying …

Field Testing Of Abrasion Resistant Carbides, Kevin C. Orme

Undergraduate Honors Capstone Projects

Chromium, tungsten, titanium, and vanadium carbides were investigated to determine relative cost of operation for each in an agricultural environment. For use on a ripper plow, these carbides were field tested in two different soil types; one soil having a matrix of gravel and cobblestones, and the other consisting of hard dirt and large underground rocks. Each alloy was applied to a high carbon plow point using an arc welding process. Along with the welded points, cast chromium carbide was tested. The results are given in price per acre and not solely longevity of the point. It was concluded that …

Modeling Habitat Quality For American Martens In Western Newfoundland, Canada, William A. Adair

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The "Den Mother" marten habitat quality models were created to provide insight into American marten habitat selection behavior and to promote the recovery of the Newfoundland marten (Martes americana atrata) population. Although these objectives are typical of most wildlife habitat modeling projects, the marten's idiosyncratic habitat ecology and apparently intractable conflicts associated with timber harvesting motivated a unique, process-oriented approach to appraising landscapes. The Den Mother models used optimal decision-making principles to synthesize critical resources (den sites and foraging opportunities) and constraints (adverse thermal situations and exposure to predations) into a single hierarchical framework. The resulting spatially explicit, …

From The Rim To The River: The Geomorphology Of Debris Flows In The Green River Canyons Of Dinosaur National Monument, Colorado And Utah, Isaac J. Larsen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Green River canyons of the eastern Uinta Mountains have experienced a 5-year period of high debris flow activity. Catchment factors were studied in watersheds and on debris fans with recent debris flows, leading to the development of a conceptual framework of the hillslope and debris flow processes that deliver sediment to the Green River. Two recent fan deposits were monitored to determine the magnitude and processes of reworking that occur during mainstem floods of varying magnitude.

The dominant debris flow initiation mechanism, termed the firehose effect, occurs when overland flow generated on bedrock slopes cascades down steep cliffs and …

Characteristics, Evolution, And Lateral Variation Of Lower Cretaceous Supradetachment Basins In The Daqing Shan, Inner Mongolia, China, Adrian K. Berry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Lower Cretaceous basins associated with the Hohhot detachment in the Daqing Shan of Inner Mongolia, China, allow us to better understand the tectonic evolution of extensional basins formed in association with detachment faulting and metamorphic core complex formation. The six basins, informally named N1, N2, S1, S2, S3, and S4, are located in different structural settings, or depozones, throughout the detachment-metamorphic core complex setting, and although all basins are consistent with previously proposed models for supradetachment basin sedimentation, second-order variability in sedimentary style is exerted by these distinct structural settings. The basins are composed of coarse, predominantly footwall derived, conglomerate …

Geology Of The Deseret Peak East 7.5' Quadrangle, Tooele County, Utah, And Impacts For Hydrology Of The Region, Torrey J. Copfer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detailed geologic mapping of the Deseret Peak East 7.5' Quadrangle yields new interpretations regarding the stratigraphy of the Oquirrh Basin, fault and fold geometry, and structural evolution of the region. The Stansbury Range consists of the north-south-trending Deseret anticline. Basal Mississippian units rest unconformably on Cambrian beds in the central part of the range. Paleozoic uplift, Mesozoic contraction, and Cenozoic extension have created a series of broad folds, large thrust faults, and several normal faults.

The area is dominated by bedrock springs, with the presence of abundant and thick Quaternary deposits unrelated to Pleistocene glaciation, burying drainages, and mantling hillslopes. …

Quaternary Geology And Landscape Evolution Of Eastern Grand Canyon, Arizona, Matt D. Anders

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tectonics and drainage evolution are controlling overall landscape incision in eastern Grand Canyon. Superimposed on downcutting are dynamic responses of hillslopes, tributary streams, and the Colorado River to glacial-interglacial climate cycles. Five tributary stream fill terraces have been identified, and luminescence dating indicates aggradation was occurring 50- 34 ka {S3), 12-7 ka (S2), and 5-3.5 ka (S1). Seven Colorado River fill terraces have been identified, and luminescence and U-series dating indicate deposition was occurring 343-322 ka (M5), 151-118 ka (M4), and 71-64 ka (M3).

Aggradation by the Colorado River in eastern Grand Canyon begins during glacial advances and continues into …

Validation Of A Radiometric Normalization Procedure For Satellite-Derived Imagery Within A Change Detection Framework, Karin E. Callahan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detecting changes in land cover through time using remotely sensed imagery is a powerful application that has seen increased use as imagery has become more widely available and inexpensive. Before a time series of remotely sensed imagery can be used for change detection, images must first be standardized for effects outside of real surface change. This thesis established a validation protocol to evaluate the effectiveness of an automated technique for normalizing temporally separate but spatially coincident imagery. Using the concept of pseudo-invariant features between master-slave image pairs, spatially coincident dark and bright points are identified from images and a regression …

Determining The Factors That Control Respiration And Carbon Use Efficiency In Crop Plants, Jonathan M. Frantz

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In the literature on plant respiration, there are two viewpoints concerning the source of respiratory control: supply (photosynthate availability) or demand (temperature dependent) limitations. While different studies indicate the primary dependency for respiration is either the supply or demand side, the two paradigms cannot both be true. The relative importance of each paradigm may depend on a number of factors including period of time during which respiration is measured, phase of plant development, environmental conditions, and species.

Studies were performed using continuous CO₂ gas-exchange instrumentation to monitor short- and long-term changes in whole canopies of lettuce, tomato, soybean, and …

Breeding Bird Communities Of Major Mainland Rivers Of Southeastern Alaska, Jim A. Johnson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Because of the scarcity of information for bird communities at the major mainland rivers of southeastern Alaska, the main objective of this study was to provide baseline information including distribution, status, and habitat associations of breeding birds.

I conducted a meta-analysis of all known reports (including the current study) conducted at major mainland rivers during the breeding season. I described bird species composition, distribution, abundance estimates, status, habitat associations, and guild membership for all birds recorded at 11 major mainland rivers. Based on incidental observations, 170 species were recorded by all studies. Of these, 134 species were known or suspected …

The Middle Cambrian Wheeler Formation: Sequence Stratigraphy And Geochemistry Across A Ramp-To-Basin Transition, Elizabeth S. Langenburg

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Cambrian Wheeler Formation is interpreted as having been deposited in the shallow ramp and deeper basin environments of the House Range embayment (HRE), presumably, during a single third-order sequence. In the Drum Mountains, the Wheeler Formation (295 m thick) is dominated by proximal and distal ramp deposits; at Marjum Pass, the Wheeler Formation (190m thick) is dominated by basinal shale deposits. The Wheeler Formation contains only one biozone marker; the first appearance of Ptyhagnostus atavus. Lack of other chronostratigraphic markers and distinctive stratal patterns in the basinal facies makes correlation along this ramp-to-basin transect difficult. Therefore, carbon-isotope …

Continuing Studies Of Water Quality In Farmington Bay And The Great Salt Lake, Utah, Amy M. Marcarelli, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

For the past three years, an Aquatic Ecology Practicum class at Utah State University has conducted research examining the limnology of Farmington Bay. In 2000, our class discovered that Farmington Bay could be classified as hypereutrophic, and had significantly higher levels of chlorophyll and phytoplankton than the Great Salt Lake proper (Marcarelli et al. 2001). In 2001, individual student projects identified high phosphorus loading into Farmington Bay from surrounding sewage treatment plants, brine shrimp biomass five times lower than in the Great Salt Lake, and that the water in the bay lost all oxygen on a windy night in October …

Secondary Electron Emission Study Of Annealed Graphitic Amorphous Carbon, Jodie Corbridge

Senior Theses and Projects

In the 1880s a curious phenomena was observed: when a ray of light, no matter how weak, hit certain metals; electrons were emitted from the surface. Called the “photoelectric effect”, this puzzle was never explained until much later. In 1905, Albert Einstein put forth one possible explanation, which is currently accepted as correct. Einstein proposed that light propagated in discrete energy packets rather than as a continuous wave. While most scientists disbelieved Einstein theory, it was later proved in detail by Robert Milikan.1 Rays of light traveling in discrete packets hit metal surfaces, depositing energy. If the energy is high …

Pastoralism Under Pressure: Tracking System Change In Southern Ethiopia, D. Layne Coppock, Solomon Desta

Environment and Society Faculty Publications

While economic development has proven elusive in African pastoral systems, change is pervasive. The Kajiado Maasai, for example, have endured declines in terms of per capita livestock holdings and other aspects of human welfare over the past 50 years. Activity diversification has occurred in Maasailand as the population copes with pressure from human population growth. We surveyed up to 317 Borana households during the late 1990s to see if similar patterns occurred in southern Ethiopia. Once viewed as an example of sustainable pastoralism, the Borana system now confronts numerous challenges. Decline in per capita cattle holdings has spurred household-level diversification …