Physical Sciences and Mathematics Commons^™

Satellite-Based Estimates Of Antarctic Surface Meltwater Fluxes, Luke D. Trusel, Karen E. Frey, Sarah B. Das, Peter Kuipers Munneke, Michiel R. Van Den Broeke

Geography

This study generates novel satellite-derived estimates of Antarctic-wide annual (1999-2009) surface meltwater production using an empirical relationship between radar backscatter from the QuikSCAT (QSCAT) satellite and melt calculated from in situ energy balance observations. The resulting QSCAT-derived melt fluxes significantly agree with output from the regional climate model RACMO2.1 and with independent ground-based observations. The high-resolution (4.45 km) QSCAT-based melt fluxes uniquely detect interannually persistent and intense melt (>400 mm water equivalent (w.e.) year-1) on interior Larsen C Ice Shelf that is not simulated by RACMO2.1. This supports a growing understanding of the importance of a föhn effect in …

Summer Co2 Evasion From Streams And Rivers In The Kolyma River Basin, North-East Siberia, Blaize A. Denfeld, Karen E. Frey, William V. Sobczak, Paul J. Mann, Robert M. Holmes

Geography

Inland water systems are generally supersaturated in carbon dioxide (CO2) and are increasingly recognized as playing an important role in the global carbon cycle. The Arctic may be particularly important in this respect, given the abundance of inland waters and carbon contained in Arctic soils; however, a lack of trace gas measurements from small streams in the Arctic currently limits this understanding.We investigated the spatial variability of CO2 evasion during the summer low-flow period from streams and rivers in the northern portion of the Kolyma River basin in north-eastern Siberia. To this end, partial pressure of carbon dioxide (pCO2) and …

Global Land Governance: From Territory To Flow?, Thomas Sikor, Graeme Auld, Anthony J. Bebbington, Tor A. Benjaminsen, Bradford S. Gentry, Carol Hunsberger, Anne Marie Izac, Matias E. Margulis, Tobias Plieninger, Heike Schroeder, Caroline Upton

Geography

This article reviews recent research on contemporary transformations of global land governance. It shows how changes in global governance have facilitated and responded to radical revalorizations of land, together driving the intensified competition and struggles over land observed in many other contributions to this special issue. The rules in place to govern land use are shifting from 'territorial' toward 'flow-centered' arrangements, the latter referring to governance that targets particular flows of resources or goods, such as certification of agricultural or wood products. The intensifying competition over land coupled with shifts toward flow-centered governance has generated land uses involving new forms …

Rare Earth Element Geochemistry Of The Sierra Blanca Laccoliths, Texas, Amed Gomez

Open Access Theses & Dissertations

No abstract provided.

Subset Semirings, Florentin Smarandache, W.B. Vasantha Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

In this book authors study the new notion of the algebraic structure of the subset semirings using the subsets of rings or semirings. This study is innovative and interesting for the authors feel giving algebraic structure to collection of sets is not a new study, for when set theory was introduced such study was in vogue. But a systematic development of constructing algebraic structures using subsets of a set is absent, except for the set topology and in the construction of Boolean algebras. The authors have explored the study of constructing subset algebraic structures like semigroups, groupoids, semirings, non commutative …

Algebraic Structures Using Subsets, Florentin Smarandache, W.B Vasantha Kandasamy

Branch Mathematics and Statistics Faculty and Staff Publications

The study of subsets and giving algebraic structure to these subsets of a set started in the mid 18th century by George Boole. The first systematic presentation of Boolean algebra emerged in 1860s in papers written by William Jevons and Charles Sanders Peirce. Thus we see if P(X) denotes the collection of all subsets of the set X, then P(X) under the op erations of union and intersection is a Boolean algebra. Next the subsets of a set was used in the construction of topological spaces. We in this book consider subsets of a semigroup or a group or a …

Scholars Day Program Of Events 2013, Carl Goodson Honors Program

Scholars Day

No abstract provided.

Creating An Interdisciplinary Research Course In Mathematical Ecology, Glenn Ledder, Brigitte Tenhumberg

School of Biological Sciences: Faculty Publications

An integrated interdisciplinary research course in biology and mathematics is useful for recruiting students to interdisciplinary research careers, but there are difficulties involved in creating and implementing it. We describe the genesis, objectives, design policies, and structure of the Research Skills in Theoretical Ecology course at the University of Nebraska–Lincoln and discuss the difficulties that can arise in designing and implementing interdisciplinary courses.

A Federated Architecture For Managing Health Information In Ethiopia, Russell Gillen Ms

All Student Scholarship

Electronic health systems can be leveraged to aid in the delivery and management of health care for patients in developing countries. The delivery of health information by mobile devices is playing an increasing role in health information management.

Quantifying The Risks Of Soil Lead In Urban Community Gardens: Sampling To Account For Spatial Variability, Lauren Elizabeth-Korgol Bugdalski

Wayne State University Theses

Urban gardening has recently gained popularity as a way to provide fresh produce and income to urban residents; however, finding suitable sites for urban gardens is challenging because of historical soil lead contamination particularly in post- industrial cities like Detroit, Michigan. Soil lead measurements from three Detroit gardens were modeled using geostatistical techniques to assess risk and alternate sampling strategies. General sampling recommendations for urban gardens were developed based on results of Monte Carlo simulations and associated risk assessment. Variograms and kriged concentration maps indicate spatial variability at scales as small as one meter, with site specific variability in spatial …

Performance Evaluation Of Voice Chat In Vechicular Ad-Hoc Networks, Vineeth Rakesh Mohan

Wayne State University Theses

Inter vehicle communication has emerged as an important area of research. With a rapid evolution of social networks, people are constantly looking for social interactions in all types of mobile environment. In this Thesis, we propose a voice chat model for Vehicle-to-Vehicle (V2V) communication that mimics a real-world group talk scenario, and measure its performance using Flood and Scalable broadcast (SBA) protocols. To evaluate the performance of the voice chat, we use different parameters such as group size, network density, transmission range and hop counts to show that our voice chat application is highly feasible in VANET environment. Furthermore, we …

Optimization Of Strategic Planning Processes For Configurable Products: Considerations For Global Supply, Demand, And Sustainability Issues, Edward Lawrence Umpfenbach

Wayne State University Dissertations

The assortment planning problem is to decide on the set of products that a retailer or manufacturer will offer to its customers to maximize profitability. While assortment planning research has been expanding in recent years, the current models are inadequate for the needs of a configurable product manufacturer. In particular, we address assortment planning for an automobile manufacturer. We develop models to integrate assortment planning and supply chain management, designed for use by a large automaker in its strategic planning phase. Our model utilizes a multinomial logit model transformed into a mixed integer linear program through the Charnes-Cooper transformation. It …

Nano-Silicon/Graphene Composite Anodes For Enhanced Performance Lithium Ion Batteries, Rhet Joseph Caballes De Guzman

Wayne State University Dissertations

The ever evolving technological applications such as with portable electronics and electric vehicles have led to increasing energy demands that have proven the existing commercial LIB capacity insufficient. Recently, the most promising anode material to substitute the traditional graphite is Si. As an anode Si has low discharge potential and theoretical the highest known theoretical capacity (>10 fold of graphite). However, due to the increased accommodated Li+ during charge-discharge reactions, silicon's volume varies up to 400%, causing pulverization and loss of electrical contact.

This dissertation focuses on a systematic approach in developing effective means to utilize Si for improved …

Lithogeochemical And Stable Isotope Characteristics Of Bristol And Northern Thorneloe Townships And Its Correlation With Gold Mineralization, Zachary Grant Stevison

Wayne State University Theses

The Porcupine Mining Camp located in the southwestend of the Abitibi Greenstone Belt has been mined extensively for its prolific precious and base metal enrichment. This study targeted Bristol and Northern Thorneloe, fifteen kilometers southwest of Timmins, ON, an area that is of economic interest for its gold mineralization. Rock samples were collected (drill- core and outcrop) throughout both townships and analyzed for their major and trace element composition, These were used to determine hydrothermal alteration signatures as well as specific elemental enrichment that relate to gold mineralization in Bristol-Thorneloe Township. Quartz-carbonate and quartz-carbonate-tourmaline vein samples were also collected near …

Take Pride In America Phase Iii - Further Development Of A Local Litter And Desert Dumping Cleanup Program: Project Compendium, Margaret N. Rees

Anti-littering Programs

The Take Pride in America in Southern Nevada project began as a collaboration of four federal agencies committed to working together to combat the litter and desert dumping problem on the nearly seven million acres of public lands in Southern Nevada. In 2005, with funding from the Southern Nevada Public Land Management Act (SNPLMA), SNAP created an interagency anti-litter and desert dumping team and developed a partnership with the Public Lands Institute (PLI) at the University of Nevada, Las Vegas. SNAP and PLI managed the Take Pride in America in Southern Nevada project and launched the Don’t Trash Nevada messaging …

Mathematical Modeling And Analysis Of Asthma Stability And Severity, Arezoo Hanifi

Electronic Theses and Dissertations

Asthma is one of the most common chronic conditions in the United States. Asthma affects about one in fifteen people. It affects children more than adults and blacks more than whites. People with asthma experience attacks of wheezing, breathlessness, chest tightness, and coughing. Asthma can be fatal and the costs for the disease (direct and indirect) are approximated to be tens of billions of dollars each year.

There is no cure for asthma. However; for most people if asthma is controlled well they can lead normal, active lives. Therefore asthma controllability is a main factor in clinical practice. In order …

A Single-Parameter Model Of The Immune Response To Bacterial Invasion, Lester Caudill

Department of Math & Statistics Faculty Publications

The human immune response to bacterial pathogens is a remarkably complex process, involving many different cell types, chemical signals, and extensive lines of communication. Mathematical models of this system have become increasingly high-dimensional and complicated, as researchers seek to capture many of the major dynamics. In this paper, we argue that, in some important instances, preference should be given to low-dimensional models of immune response, as opposed to their high-dimensional counterparts. One such model is analyzed and shown to reflect many of the key phenomenological properties of the immune response in humans. Notably, this model includes a single parameter values, …

Quantitative Analysis Of Surface Enhanced Raman Spectra, Shuo Li

Computer Science and Engineering Dissertations

Quantitative analysis of Raman spectra using surface-enhanced Raman scattering (SERS) nanoparticles has shown the potential and promising trend of development in vivo molecular imaging. One of the key job is from the intensities of Raman signals to predict the quantities of analytes. Direct classical least squares (DCLS) and multivariate calibration (MC) are commonly used methods. DCLS relies on source Raman signals as the references. But the inherent Instability of Raman signals make the DCLS model not robust enough. MC model relies on a batch of training mixture Raman signals together with the ground truth mixing concentrations to build the multivariate …

Advanced Combinatorial Testing Algorithms And Applications, Linbin Yu

Computer Science and Engineering Dissertations

Combinatorial testing (CT) has been shown to be a very effective testing strategy. Given a system with n parameters, t-way combinatorial testing, where t is typically much smaller than n, requires that all t-way combinations, i.e., all combinations involving any t parameter values, be covered by at least one test. This dissertation focuses on two important problems in combinatorial testing, including constrained test generation and combinatorial sequence testing.For the first problem, we focus on constraint handling during combinatorial test generation. Constraints over input parameters are restrictions that must be satisfied in order for a test to be valid. Constraints can …

Ecology Of Glacial Relict Fishes In South Dakota's Sandhills Region, Eli Felts

Electronic Theses and Dissertations

Native stream fish zoogeography has changed substantially across North America during the last century as habitat degradation, stream fragmentation and introductions of nonnative species have led to numerous extinctions, extirpations and altered distributions. Insufficient information regarding imperiled species often results in reactive, rather than proactive, management, and knowledge of species status and ecology is critical in identifying conservation priorities. South Dakota populations of three dace species (northern redbelly dace Chrosomus eos, finescale dace Chrosomus neogaeus, and pearl dace Margariscus margarita) are relict of Pleistocene Glaciation and are isolated from the northern core of their distribution, but little information exists regarding …

Reverse Carleson Embeddings For Model Spaces, William T. Ross, Alain Blandigneres, Emmanuel Fricain, Frederic Gaunard, Andreas Hartmann

Department of Math & Statistics Faculty Publications

The classical embedding theorem of Carleson deals with finite positive Borel measures μ on the closed unit disk for which there exists a positive constant c such that for all f∈H², the Hardy space of the unit disk. Lefèvre et al. examined measures μ for which there exists a positive constant c such that for all f∈H². The first type of inequality above was explored with H² replaced by one of the model spaces (Θ H²)^⊥ by Aleksandrov, Baranov, Cohn, Treil, and Vol'berg. In this paper, we discuss …

A Superposed Log-Linear Failure Intensity Model For Repairable Artillery Systems, Byeong Min Mun, Suk Joo Bae, Paul Kvam

Department of Math & Statistics Faculty Publications

This article investigates complex repairable artillery systems that include several failure modes. We derive a superposed process based on a mixture of nonhomogeneous Poisson processes in a minimal repair model. This allows for a bathtub-shaped failure intensity that models artillery data better than currently used methods. The method of maximum likelihood is used to estimate model parameters and construct confidence intervals for the cumulative intensity of the superposed process. Finally, we propose an optimal maintenance policy for repairable systems with bathtub-shaped intensity and apply it to the artillery-failure data.

Galaxy Inclination And Surface Brightness, Jordan C. Rozum, Shane L. Larson

Student Showcase

The distribution of spiral and bar galaxy inclination angles is expected to be uniform. However, analysis of several major galaxy catalogs shows this is not the case; galaxies oriented near edge-on are significantly more common in these catalogs. In an attempt to explain this discrepancy, we have developed a galaxy simulation code to compute the appearance of a spiral type galaxy as a function of its morphological parameters. We examine the dependence of observed brightness upon inclination angle by using smooth luminous mass density and interstellar medium (ISM) density distributions. The luminous mass component is integrated along a particular line …

High-Latitude Short-Period Mesospheric Gravity Wave Dynamics And Winter Climatology, Michael Negale, Kim Nielsen, Michael J. Taylor, Dominique Pautet, Margit Dyrland

Physics Student Research

Short-period gravity wave observations over the Arctic region are few and their impact on the Arctic mesosphere lower thermosphere region via momentum deposition is of high interest. The Mesospheric Airglow Imaging and Dynamics project was initiated in January 2011 to investigate the presence and dynamics of these waves over the interior of Alaska. Observations were made from Poker Flat Research Range (PFRR) using an all-sky imager. This site provides an exceptional opportunity to establish a long-term climatology of short-period gravity waves in the Arctic Region. We present summary measurements of prominent gravity waves over two consecutive winters and compare their …

Gravitational Gauge Theory And The Existence Of Time, James Thomas Wheeler

All Physics Faculty Publications

General relativity may be formulated as a gauge theory more than one way using the quotient manifold approach. We contrast the structures that arise in four gravitational gauge theories, three of which give satisfactory gauge theoris of general relativity. Of particular interest is the quotient of the conformal group of a flat space by its Weyl subgroup, which always has natural symplectic and metric structures in addition to the requisite manifold. This quotient space admits canonically conjugate, orthogonal, metric submanifolds distinct from the original space if and only if the original flat space has signature n, -n or 0. In …

Small-Scale Simulation Chamber For Space Environment Survivability Testing, Robert H. Johnson, Lisa D. Montierth, Jr Dennison, James S. Dyer, Ethan R. Lindstrom

Browse All Undergraduate research

A vacuum chamber was designed that simulates the space environment to facilitate tests of material modification due to space environment interactions. Critical environmental elements to be simulated include an ultra high vacuum, a FUV/UV/VIS/NIR solar spectrum, an electron plasma flux, temperature extremes, and long duration exposure. To simulate the solar electromagnetic spectrum (EMS), a solar simulator was used with a range of 200 nm to 2000 nm. A Krypton lamp provides surrogate radiation for the prominent far ultraviolet hydrogen Lyman-α 120 nm emission not produced by the solar simulator. A mono-energetic electron flood gun (20 eV to 15 keV) provides …

Carrier Capture Dynamics Of Single Ingaas/Gaas Quantum-Dot Layers, Kripa N. Chauhaun, D. Mark Riffe, Addison E. Everett, D. J. Kim, H Yang, F. K. Shen

All Physics Faculty Publications

Using 800nm, 25-fs pulses from a mode locked Ti:Al2O3 laser, we have measured the ultrafast optical reflectivity of MBE-grown, single-layer In0.4Ga0.6As/GaAs quantum-dot (QD) samples. The QDs are formed via two-stage Stranski-Krastanov growth: following initial InGaAs deposition at a relatively low temperature, self assembly of the QDs occurs during a subsequent higher temperature anneal. The capture times for free carriers excited in the surrounding GaAs (barrier layer) are as short as 140fs, indicating capture efficiencies for the InGaAs quantum layer approaching 1. The capture rates are positively correlated with initial InGaAs thickness and annealing temperature. With increasing excited carrier density, the …

Carrier Capture Dynamics Of Single Ingaas/Gaas Quantum-Dot Layers, K. N. Chauhan, D. Mark Riffe, E. A. Everett, D. J. Kim, H. Yang, F. K. Shen

All Physics Faculty Publications

Using 800 nm, 25-fs pulses from a mode locked Ti:Al₂O₃ laser, we have measured the ultrafast opticalreflectivity of MBE-grown, single-layer In_0.4Ga_0.6As/GaAs quantum-dot (QD) samples. The QDs are formed via two-stage Stranski-Krastanov growth: following initial InGaAs deposition at a relatively low temperature, self assembly of the QDs occurs during a subsequent higher temperature anneal. The capture times for free carriers excited in the surrounding GaAs (barrier layer) are as short as 140 fs, indicating capture efficiencies for the InGaAs quantum layer approaching 1. The capture rates are positively correlated with initial InGaAs thickness and …

Properties Of Cathodoluminescence For Cryogenic Applications Of Sio2-Based Space Observatory Optics And Coatings, Amberly Evans Jensen, Jr Dennison, Gregory Wilson, Justin Dekany, Charles Bpwers, Robert Meloy, James B. Heaney

Conference Proceedings

Disordered thin film SiO2/SiOx coatings undergoing electron-beam bombardment exhibit cathodoluminescence, which can produce deleterious stray background light in cryogenic space-based astronomical observatories exposed to high- energy electron fluxes from space plasmas. As future observatory missions push the envelope into more extreme environments and more complex and sensitive detection, a fundamental understanding of the dependencies of this cathodoluminescence becomes critical to meet performance objectives of these advanced space-based observatories. Measurements of absolute radiance and emission spectra as functions of incident electron energy, flux, and power typical of space environments are presented for thin (~60-200 nm) SiO2/SiOx optical coatings on reflective metal …

Electron Transport Models And Precision Measurements With The Constant Voltage Conductivity Method, Justin Dekany, Jr Dennison, Alec Sim, Jerilyn Brunson

Graduate Student Publications

Recent advances are described in the techniques, resolution, and sensitivity of the Constant Voltage Conductivity (CVC) method and the understanding of the role of charge injection mechanisms and the evolution of internal charge distributions in associated charge transport theories. These warrant reconsideration of the appropriate range of applicability of this test method to spacecraft charging. We conclude that under many (but not all) common spacecraft charging scenarios, careful CVC tests provide appropriate evaluation of conductivities down to ≈10-22 (Ω-cm)-1, corresponding to decay times of many years.

We describe substantial upgrades to an existing CVC chamber, which improved the precision of …