Physical Sciences and Mathematics Commons^™

Beyond The Chemistry Web, Bob Buchanan

Sci-Tech News

No abstract provided.

Web Reviews, Lisa R. Johnston

Sci-Tech News

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Materials Research & Manufacturing Section, Nora Stoeker

Sci-Tech News

No abstract provided.

Sci-Tech Book News Reviews, Susan Fingerman

Sci-Tech News

No abstract provided.

Full Issue: Vol. 62, No. 4

Sci-Tech News

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New Science And Technology Journals, Earl Mounts

Sci-Tech News

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Division Officers And Boards

Sci-Tech News

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Decadal-Scale Changes On Coral Reefs In Quintana Roo, Mexico, Thaddeus Allen Nicholls

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In 1988 data on coral reef community composition were collected from two areas, Akumal and Chemuyil, Quintana Roo, Mexico, ranging from 5-35m depth. These areas were revisited in 2005 and data were collected by the same methods and at the same depths as in 1988. Data from 1988 and 2005 were compared to determine if the coral reefs had undergone significant changes, and what specific changes had occurred. Chi-square analysis determined that community composition data collected in 1988 are significantly different from data collected in 2005 at all sites and depths within the categories of corals, gorgonians, sponges, and macroalgae. …

Factors Related To Success And Participants’ Psychological Ownership In Collaborative Wildlife Management: A Survey Of Sage-Grouse Local Working Groups, Lorien R. Belton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Declines of sage-grouse (Centrocercus spp.) across the western United States have prompted the formation of numerous collaborative stakeholder partnerships, known as local working groups. These voluntary groups create and implement local sage-grouse management plans and projects, often in the hopes that their efforts may help avert a federal Endangered Species designation for the bird. Using a mail survey of participants in 54 local working groups, I examined the importance of psychological ownership in working group dynamics. Psychological ownership is conceptualized as a latent, multidimensional variable consisting of responsibility, control, and caring elements. Multiple regression analysis showed early-stage group success, representative …

Development Of A Post-Fire Monitoring Protocol For Evaluating Treatment Effectiveness And Cheatgrass Abundance Using Quickbird Imagery And Ground Observations, Gabriel Bissonette

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Bureau of Land Management (BLM) manages 9.3 million hectares of land in Utah and has implemented an Emergency Stabilization and Rehabilitation (ESR) Program to protect life and property, combat soil erosion, and reduce the invasion of exotic/noxious weeds following wildland fire. In highly vulnerable sites, seeding treatments may be applied to establish an interim landcover to stabilize the soil and competitively exclude weed invasions. Monitoring treatment effectiveness is mandated through ESR guidelines and necessary for the submission of annual Accomplishment Reports for the first three years following fire containment. Ground monitoring has been the traditional approach to fulfilling this …

Impact Analysis Of System And Network Attacks, Anupama Biswas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Systems and networks have been under attack from the time the Internet first came into existence. There is always some uncertainty associated with the impact of the new attacks. Compared to the problem of attack detection, analysis of attack impact has received very little attention. Generalize and forecasting the kind of attack that will hit systems in future is not possible. However, it is possible to predict the behavior of a new attack and, thereby, the impact of the attack. This thesis proposes a method for predicting the impact of a new attack on systems and networks as well as …

A C To Register Transfer Level Algorithm Using Structured Circuit Templates: A Case Study With Simulated Annealing, Jonathan D. Phillips

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A tool flow is presented for deriving simulated annealing accelerator circuits on a field programmable gate array (FPGA) from C source code by exploring architecture solutions that conform to a preset template through scheduling and mapping algorithms. A case study carried out on simulated annealing-based Autonomous Mission Planning and Scheduling (AMPS) software used for autonomous spacecraft systems is explained. The goal of the research is an automated method for the derivation of a hardware design that maximizes performance while minimizing the FPGA footprint. Results obtained are compared with a peer C to register transfer level (RTL) logic tool, a state-of-the-art …

Approximations To Continuous Processes In Hierarchical Models, Amanda Cangelosi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Models for natural nonlinear processes, such as population dynamics, have been given much attention in applied mathematics. For example, species competition has been extensively modeled by differential equations. Often, the scientist has preferred to model the underlying dynamical processes (i.e., theoretical mechanisms) in continuous-time. It is of both scientific and mathematical interest to implement such models in a statistical framework to quantify uncertainty associated with the models in the presence of observations. That is, given discrete observations arising from the underlying continuous process, the unobserved process can be formally described while accounting for multiple sources of uncertainty ( …

Two Highly Diverse Studies In Computing: A Vitruvian Framework For Distribution And A Search Approach To Cancer Therapies, Brian G. Smith

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Solid cancer tumors must recruit new blood vessels for growth and maintenance. Discovering drugs that block this tumor-induced development of new blood vessels (angiogenesis) is an important approach in cancer treatment. However, the complexity of angiogenesis and the difficulty in implementing and evaluating medical changes prevent the discovery of novel and effective new therapies. This paper presents a massively parallel computational search-based approach for the discovery of novel potential cancer treatments, using a high fidelity simulation of angiogenesis. Discovering new therapies is viewed as multi-objective combinatorial optimization over two competing objectives: minimizing the medical cost of the intervention while minimizing …

Sedimentology, Stratigraphy, And Organic Geochemistry Of The Red Pine Shale, Uinta Mountains, Utah: A Prograding Deltaic System In A Mid-Neoproterozoic Interior Seaway, Caroline Amelia Myer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Red Pine Shale (RPS; ~1120m thick), uppermost formation of the Neoproterozoic Uinta Mountain Group, Utah, is an organic-rich sedimentary succession interpreted as a marine deltaic system that delivered immature sediment from the north that mixed with mature sediment from the east. Multiple data sets suggest regional climate and sea-level changes associated with changing organic-carbon burial rates.

Six facies were identified and represent wave-, tidal-, and river-influenced parts of the distal prodelta to delta front in a marine system. These include the shale facies and associated concretion facies (distal prodelta), the shale-sandstone facies (proximal prodelta to delta front), the slump …

Perceived Crowding And Visitor Support For Use Rationing: A Reanalysis Of Existing Data, Jascha M. Zeitlin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents a reanalysis of data collected between 1999 and 2006 by the Institute for Outdoor Recreation and Tourism (IORT) at Utah State University. These data concern a variety of outdoor recreation sites in Utah, Idaho, and South Dakota, and were collected via intercept, mail, and, to a very limited extent, telephone surveys. Survey instruments contained questions related to visitor perceptions of crowding, overall satisfaction, support for use limits/rationing, and estimates of use density, in addition to other conceptually related factors.

Analyses consisted of multiple regression models for both perceived crowding and visitor support for use limits dependent variables …

Hydrological Characterization Of A Riparian Vegetation Zone Using High Resolution Multi-Spectral Airborne Imagery, Osama Zaki Akasheh

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Middle Rio Grande River (MRGR) is the main source of fresh water for the state of New Mexico. Located in an arid area with scarce local water resources, this has led to extensive diversions of river water to supply the high demand from municipalities and irrigated agricultural activities. The extensive water diversions over the last few decades have affected the composition of the native riparian vegetation by decreasing the area of cottonwood and coyote willow and increasing the spread of invasive species such as Tamarisk and Russian Olives, harmful to the river system, due to their high transpiration rates, …

Understanding Unfolding Change And The Value Of Strategic Unification In Recent Usu Information Technology Functional Realignment, Eric S. Hawley

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This is a qualitative case study of the 2005-2008 Utah State University Information Technology reorganization from the perspective of key change advocates. The study identified and documented the unfolding change process involved in the reorganization in terms of dissatisfaction, executive changes, internal executive strategic planning, implementation and initial impacts, and continuous "in situ" strategic planning. The study also answered a set of supporting concluding questions indicating increased value to the institution in areas of customer service and confidence, organization, financial resources, planning and policy, security, and increased/improved services and service functions.

A Novel Authentication And Validation Mechanism For Analyzing Syslogs Forensically, Steena D.S. Monteiro

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research proposes a novel technique for authenticating and validating syslogs for forensic analysis. This technique uses a modification of the Needham Schroeder protocol, which uses nonces (numbers used only once) and public keys. Syslogs, which were developed from an event-logging perspective and not from an evidence-sustaining one, are system treasure maps that chart out and pinpoint attacks and attack attempts. Over the past few years, research on securing syslogs has yielded enhanced syslog protocols that focus on tamper prevention and detection. However, many of these protocols, though efficient from a security perspective, are inadequate when forensics comes into play. …

Darboux Integrability Of Wave Maps Into 2-Dimensional Riemannian Manifolds, Robert Ream

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The harmonic map equations can be represented geometrically as an exterior differential system (EDS), ε. Using this representation we study the harmonic maps from 2D Minkowski space into 2D Riemannian manifolds. These are also known as wave maps. In this case, E is invariant under conformal transformations of Minkowski space. The quotient of ε by these conformal transformations, E/G, is an s=0 hyperbolic system.

The main result of our study is that the prolonged EDS, ε^(k), is Darboux integrable if and only if the prolonged quotient EDS, ε^(k+1), is Darboux integrable. We also find invariants determining …

Optimal Irrigation Management For Sloping, Blocked-End Borders, Jorge Jose Escurra

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A robust mathematical model of one-dimensional flow for sloping, blocked-end border irrigation was developed using the four-point implicit method to solve the Saint-Venant equations, the volume-balance solution method, and the implementation of new algorithms to avoid numerical instability and solution divergence. The model has the capability of successfully simulating all surface irrigation phases in blocked-end borders for a range of inflow rates (0.01 - 0.05 m³/s per m), longitudinal slopes (up to 1.00%), and border lengths (100 - 500 m).

To achieve numerical stability over the specified parameter ranges, the model was divided into three parts: (1) advance-phase …

An Evolutionary Approach To Image Compression In The Discrete Cosine Transform Domain, Benjamin E. Banham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper examines the application of genetic programming to image compression while working in the frequency domain. Several methods utilized by JPEG encoding are applied to the image before utilizing a genetic programming system. Specifically, the discrete cosine transform (DCT) is applied to the original image, followed by the zig-zag scanning of DCT coefficients. The genetic programming system is finally applied to the one-dimensional array resulting from the zig-zag scan. The research takes an existing genetic programming system developed for the spatial domain and develops DCT domain functionality. The results from the DCT domain-based genetic programming system are compared with …

Pulse-Laser Infrared Photothermal Spectrometry Of Condensed-Phase Aerosols Based On Photothermal Deflection Spectroscopy, Oluwatosin Olubunmi Dada

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The research reported in this dissertation is aimed at development of photothermal deflection detector that is consistent with constraints imposed by aerosols sampling and analysis. The main objectives of this project are: 1) the design and evaluation of initial apparatus prototypes and 2) a test of the prototype apparatus with surrogate substances using conventional mid-infrared gas lasers.

Experimental evaluation of reduced size photothermal apparatus is first performed with gaseous samples. Analysis of trichlorofluoromethane (CFC-11) and ethanol vapors is performed with both conventional large apparatus and the prototype small apparatus. Comparison studies in terms of photothermal signal from both apparatuses are …

Solarization Effects On Chemical Properties Of Soils Under Kudu (Pueraria Montana) Invasion, Nicole Gilbert

All Theses

Solarization is an effective method for managing small areas with kudzu (Pueraria montana) invasions that may alter soil chemical properties. Conducted from 2005 to 2007 at the Clemson University Experimental Forest in Clemson, South Carolina on a Cecil clay loam (fine, kaolinitic, thermic Typic Kanhapludult), this study compares soil chemical properties under thermally-treated and non-treated plots at different depths invaded by Kudzu.
The experimental factors of treatment and depth were arranged in a factorial treatment design with 15 treatments arranged in a split plot design. The five thermal treatments were the whole plot factors which were arranged in a randomized …

Insights Into Biogeophysical Signatures Using Polarization Force Microscopy, Elizabeth Bartosik

All Theses

The success of bioremediation strategies is dependent upon effective monitoring of microorganisms in the subsurface. Induced polarization (IP) may represent a cost-effective, complementary technique to existing borehole-based microbe detection schemes. Recent studies show a significant, yet poorly understood IP effect associated with the presence of bacteria in aqueous and porous media. This effect is believed to be rooted in the physicochemical surface interactions between cells and minerals which we probe using polarization force microscopy. Polarization force experiments were conducted on a hydrated mica surface using the gram positive bacterium Bacillus subtilis and the gram negative bacterium Escherichia coli. On all …

Probing Grb Environments Through X-Ray Absorption, Hala Eid

All Theses

Although long-duration GRBs (LGRBs) are highly transient in nature, their early afterglow can in principle be detected to very high redshifts (Lamb & Reichart, 2000). This makes them potent probes of the chemical evolution and content of the high-redshift universe. In this work, we use photoelectric absorption observed in the XRT spectra of LGRBs to investigate the evolution of metallicities and hydrogen column densities of LGRB host galaxies. Using a high-quality sample of LGRBs indicates the presence of a weak anti-correlation between the abundances and redshift. We also find an evolution trend in intrinsic column density. To confirm these correlations, …

Magnetohydrodynamic Effects In Propagating Relativistic Jets: Reverse Shock And Magnetic Acceleration, Yosuke Mizuno, Bing Zhang, Bruno Giacomazzo, Ken-Ichi Nishikawa, Phillip E. Hardee, Shigehiro Nagataki, Dieter H. Hartmann

Publications

We solve the Riemann problem for the deceleration of an arbitrarily magne-tized relativistic flow injected into a static unmagnetized medium in one dimen-sion. We find that for the same initial Lorentz factor, the reverse shock becomes progressively weaker with increasing magnetization σ (the Poynting-to-kinetic energy flux ratio), and the shock becomes a rarefaction wave when σ exceeds a critical value, σc, defined by the balance between the magnetic pressure in the flow and the thermal pressure in the forward shock. In the rarefaction wave regime, we find that the rarefied region is accelerated to a Lorentz factor that is significantly …

Scattering Of An Electromagnetic Plane Wave By A Luneburg Lens. Ii. Wave Theory, James A. Lock

Physics Faculty Publications

The partial wave scattering and interior amplitudes for the interaction of an electromagnetic plane wave with a modified Luneburg lens are derived in terms of the exterior and interior radial functions of the scalar radiation potentials evaluated at the lens surface. A Debye series decomposition of these amplitudes is also performed and discussed. The effective potential inside the lens for the transverse electric polarization is qualitatively examined, and the approximate lens size parameters of morphology-dependent resonances are determined. Finally, the physical optics model is used to calculate wave scattering in the vicinity of the ray theory orbiting condition in order …

Rainbows In The Grass. I. External Reflection Rainbows From Pendant Droplets, James A. Lock, Charles L. Adler, Richard W. Fleet

Physics Faculty Publications

In the mid-morning on a sunny day one can sometimes see glare spots associated with uncolored "rainbow" (i.e., fold) caustics due to the sunlight reflected from the surface of dew or guttation drops. We show that these dewdrop reflection rainbows are due to places on the droplet (i.e., from an "inflection circle") where its Gaussian curvature becomes zero. We work out the theory of such caustics with horizontally incident light and present a comparison of the theory to measurements made in the laboratory. (C) 2008 Optical Society of America

Scattering Of An Electromagnetic Plane Wave By A Luneburg Lens. I. Ray Theory, James A. Lock

Physics Faculty Publications

For a plane wave incident on either a Luneburg lens or a modified Luneburg lens, the magnitude and phase of the transmitted electric field are calculated as a function of the scattering angle in the context of ray theory. It is found that the ray trajectory and the scattered intensity are not uniformly convergent in the vicinity of edge ray incidence on a Luneburg lens, which corresponds to the semiclassical phenomenon of orbiting. In addition, it is found that rays transmitted through a large-focal-length modified Luneburg lens participate in a far-zone rainbow, the details of which are exactly analytically soluble …