Physical Sciences and Mathematics Commons^™

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 …

Experimental Determination Of The Weiss Temperature Of Mn12-Ac And Mn12-Ac-Meoh, Christos Lampropoulos, Shiqi Li, Lin Bo, Bo Wen, M P. Sarachik, P Subedi, A D. Kent, Y Yeshurun, A J. Millis, S Mukherjee, G Christou

Chemistry Faculty Research and Scholarship

We report measurements of the susceptibility in the temperature range from 3.5 to 6.0 K of a series of Mn₁₂-ac and Mn₁₂-ac-MeOH samples in the shape of rectangular prisms of length l_c and square cross section of side l_a. The susceptibility obeys a Curie-Weiss law, χ=C/(T−θ), where θ varies systematically with sample aspect ratio. Using published demagnetization factors, we obtain θ for an infinitely long sample corresponding to intrinsic ordering temperatures T_c≈0.85 K and ≈0.74 K for Mn₁₂-ac and Mn₁₂-ac-MeOH, respectively. The difference in T_c for …

Discrete-Time Multi-Scale Systems, Daniel Alpay, Mamadou Mboup

Mathematics, Physics, and Computer Science Faculty Articles and Research

We introduce multi-scale filtering by the way of certain double convolution systems. We prove stability theorems for these systems and make connections with function theory in the poly-disc. Finally, we compare the framework developed here with the white noise space framework, within which a similar class of double convolution systems has been defined earlier.

Matrix Singular Value Decomposition, Petero Kwizera

UNF Graduate Theses and Dissertations

This thesis starts with the fundamentals of matrix theory and ends with applications of the matrix singular value decomposition (SVD). The background matrix theory coverage includes unitary and Hermitian matrices, and matrix norms and how they relate to matrix SVD. The matrix condition number is discussed in relationship to the solution of linear equations. Some inequalities based on the trace of a matrix, polar matrix decomposition, unitaries and partial isometies are discussed. Among the SVD applications discussed are the method of least squares and image compression. Expansion of a matrix as a linear combination of rank one partial isometries is …

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.

Post-Coring Entrapment Of Modern Air In Some Shallow Ice Cores Collected Near The Firn-Ice Transition: Evidence From Cfc-12 Measurements In Antarctic Firn Air And Ice Cores, Murat Aydin, S. A. Montzka, M. O. Battle, M. B. Williams, Warren J. De Bruyn, J. H. Butler, K. R. Verhulst, C. Tatum, B. K. Gun, D. A. Plotkin, B. D. Hall, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In this study, we report measurements of CFC-12 (CCl2F2) in firn air and in air extracted from shallow ice cores from three Antarctic sites. The firn air data are consistent with the known atmospheric history of CFC-12. In contrast, some of the ice core samples collected near the firn-ice transition exhibit anomalously high CFC-12 levels. Together, the ice core and firn air data provide evidence for the presence of modern air entrapped in the shallow ice core samples that likely contained open pores at the time of collection. We propose that this is due to closure of the open pores …

A Multidimensional Strategy To Detect Polypharmacological Targets In The Absence Of Structural And Sequence Homology, Jacob D. Durrant, Rommie E. Amaro, Lei Xie, Michael D. Urbaniak, Michael A. J. Ferguson, Antti Haapalainen, Zhijun Chen, Anne Marie Di Guilmi, Frank Wunder, Philip E. Bourne, J. Andrew Mccammon

Publications and Research

Conventional drug design embraces the ‘‘one gene, one drug, one disease’’ philosophy. Polypharmacology, which focuses on multi-target drugs, has emerged as a new paradigm in drug discovery. The rational design of drugs that act via polypharmacological mechanisms can produce compounds that exhibit increased therapeutic potency and against which resistance is less likely to develop. Additionally, identifying multiple protein targets is also critical for side-effect prediction. One third of potential therapeutic compounds fail in clinical trials or are later removed from the market due to unacceptable side effects often caused by off-target binding. In the current work, we introduce a multidimensional …

Regional Vs. Local Impact Of Wind On Glaciers In The Andes Mountains, Derek Ferris

Undergraduate Review

Northern Peru will face critical water resource issues in the near future as permanent ice in the Andes Mountains continues to rapidly melt. Ironically, the melt-water from these glaciers supports the culture of 100s of thousands of people living at lower elevations, particularly during the dry season, and predictions suggest some glaciers may be gone in less than 100 years. The impact of local warming of “U” shaped valleys running down the dryer western slope of the Andes range is largely disregarded in current climate model predictions because of the complexity of simulating the complex topography. Studies that compare the …

The Investigation Of Hardness And Bonding Behavior In Xb_4, X = {Ce, Th, U, Pa}, Tetraborides By First-Principles, Sezgi̇n Aydin, Aynur Tatar

Turkish Journal of Physics

The mechanical and electronic properties of XB_4, X = {Ce, Th, U, Pa}, tetraborides have been studied by using first-principles based on density functional theory. The results show that these boron-rich solids are mechanically and thermodynamically stable. From the calculated band structure and density of states, we obtained that they have metallic character. When the calculated parameters related to the crystal structure were considered with the bonding characteristics, the microscopic hardnesses of these boron-rich solids can be theoretically calculated. The obtained hardness values indicate that, these materials are hard, but not superhard. Furthermore, from the detailed hardness analysis, we found …

Computations Of Ultrasonic Parameters Of Lanthanide Metals Ti, Zr And Hf, Pramod Kumar Yadawa, Dharmendra Kumar Pandey, Devraj Singh, Raja Ram Yadav, Giridhar Mishra

Turkish Journal of Physics

The ultrasonic properties in the hexagonal structured lanthanide metals Ti, Zr and Hf have been studied at room temperature. The higher order elastic constants have been calculated for these metals using Lennard-Jones Potential for evaluating orientation-dependent ultrasonic properties. An anomalous behaviour in orientation dependent velocity is obtained, which is due to the combined effect of second order elastic constants and density. The achieved ultrasonic properties are compared with known physical parameters to differentiate them from third group nitrides/laves phase compounds.

Extending K-8 Mathematics Concepts In Alternate Bases, Dianna J. Spence

Proceedings of the Annual Meeting of the Georgia Association of Mathematics Teacher Educators

When learning to represent mathematics with manipulatives, many pre-service K-8 teachers rely on memorized rote procedures to perform the associated mathematical tasks; then they arrange the manipulatives to match their result, often with minimal understanding of underlying mathematical connections. In a Number and Operations course for K-8 pre-service teachers, a portion of the class was conducted in alternate bases: Base 6 and Base 8 Blocks were used to model operations with integers to facilitate deeper understanding of the number systems and arithmetic processes being represented. Fractions and decimals were later covered only in Base 10. On midterm and final exams, …

Fluctuation Conductivity Of Single-Crystalline Bafe1.8 Co0.2as2 In The Critical Region, Soo Hyun Kim, Changho Choi, Myung-Hwa Jung, Jung-Bum Yoon, Young-Hun Jo, Xiaolin Wang, X.H Chen, X.F Wang, Sung-Ik Lee, Ki-Young Choi

Australian Institute for Innovative Materials - Papers

The magnetofluctuation conductivity, called excess conductivity, originated from the forming of the superconducting droplet near to the mean-field transition temperature, was measured for the optimally doped BaFe_1.8Co_0.2As₂ single crystals with a critical temperature, T_c, of 24.6 K. This measurement of the excess conductivity for magnetic fields up to 9 T was compared with the thermodynamic scaling theory in the critical region, in which not only the Gaussian fluctuation but also fourth order terms of the order parameter are included. An analysis of the excess conductivity showed that the superconductivity followed three-dimensional scaling rather …

Assessing The Feasibility Of An Aerotropolis Around Cleveland Hopkins International Airport, Appendices, Claudette Robey, Daila Shimek, James Wyles, Brian A. Mikelbank, Jim Robey, Kevin O'Brien, Et.Al.

All Maxine Goodman Levin School of Urban Affairs Publications

This is a companion report to the full technical report entitled, “Assessing the Feasibility of an Aerotropolis Around Cleveland Hopkins International Airport.” This report contains the supporting documents including interview scripts, focus group protocol, a reference list and glossary, cooperative economic development agreements, airport case studies, a map of physical property characteristics, and endnotes for the appendices.

Song Of Wekiva: Florida’S Wild River And Its Democratic Vista, Steve Phelan

Faculty Publications

Today hundreds of thousands enjoy the river every year. We are a different breed. When I take our children or my students to the river or walk along its sandy uplands to show them undiscovered and unmapped springs popping out of the ground, they and I are still abiding in a domesticated world that erects a substantial, almost impervious barrier to the wilderness of the river. Nevertheless, that wildness is built unconsciously into our bodies. We are not like the Timucuans, the first humans to come down the St. Johns River and eventually up the Wekiva to the two main …

Chemical Structure Of Vanadium-Based Contact Formation On N-Ain, S. Pookpanratana, R. France, M. Blum, Sean R. Mulcahy, A. Bell, M. Bär, L. Weinhardt, Y. Zhang, T. Hofmann, O. Fuchs, W. Yang, J. D. Denlinger, T. D. Moustakas, C. Heske

Geology Faculty Publications

We have investigated the chemical interaction between a Au/V/Al/V layer structure and n-type AlN epilayers using soft x-ray photoemission, x-ray emission spectroscopy, and atomic force microscopy. To understand the complex processes involved in this multicomponent system, we have studied the interface before and after a rapid thermal annealing step. We find the formation of a number of chemical phases at the interface, including VN, metallic vanadium, aluminum oxide, and metallic gold. An interaction mechanism for metal contact formation on the entire n-Al,GaN system is proposed. ©

Nmr Investigations Of Biomass-To-Fuel Conversions By Hydrothermal Processes, Wenjia Zhang

Doctoral Dissertations

"Biofuels have gained significant attention as the most promising alternative energy and fuel supply for the near future because of two dominant reasons: first, biofuels are environmentally friendly; and second, they afford a sustainable technology. Biofuels can be synthesized from biomass by several different processes, among which, hydrothermal conversion is considered to be more energy efficient. However, scientific efforts to improve hydrothermal biomass-to-fuel (HT-BTF) conversion efficiencies are severely limited because little is known about the salient reaction mechanisms and intermediates. This study is aimed at a better understanding of the hydrothermal biomass degradation kinetics by advanced NMR spectroscopy and, accordingly, …

Effect Of Structure And Plasticizer On The Glass Transition Of Adsorbed Polymer, Boonta Hetayothin

Doctoral Dissertations

"The effect of molecular mass on adsorbed poly(methyl methacrylate) (PMMA) on silica was determined using temperature-modulated differential scanning calorimetry (TMDSC). A two-component model, based on loosely-bound polymer (glass transition temperature, T_g, similar to that of bulk) and tightly-bound polymer (T_g higher than that of bulk) was used to interpret the thermograms. Similar amounts of tightly-bound polymer were found for 450 and 85 kDa PMMA (0.78 mg/m²), while the 32 kDa sample had a smaller amount (0.48mg/m²). A comparison of adsorbed PMMA, poly(vinyl acetate) (PVAc), and poly(methyl acrylate) (PMA) on silica was made using the same technique. The …