Physical Sciences and Mathematics Commons^™

Use Of International Hydrographic Organization Tidal Data For Improved Tidal Prediction, Songwei Qi

Dissertations and Theses

Tides are the rise and fall of water level caused by gravitational forces exerted by the sun, moon and earth. Understanding sea level variation and its impact currents is very important especially in coastal regions. With knowledge of the tide-generating force and boundary conditions, hydrodynamic models can be used to predict or model tides in coastal regions. However, these models are not sufficiently accurate, and in-situ tide gauge data may be used to improve them in coastal regions. The International Hydrographic Organization (IHO) tidal data bank consists of over 4000 tide gauge stations scattered all around the globe, most of …

Topographic Influences On Trends And Cycles In Nutrient Export From Forested Catchments On The Precambrian Shield, Samson G. Mengistu

Electronic Thesis and Dissertation Repository

This dissertation explored topographic controls on spatial and temporal patterns in water yield and nutrient (carbon, nitrogen and phosphorus) export from forested headwater catchments in the Turkey Lakes Watershed in central Ontario, where other factors contributing to differences in water yield and nutrient export, including climate, geology, forest, and soils, are relatively constant. Topographic characteristics, including (a) hydrological flushing potential (expansion of water table into nitrate-N producing areas); (b) hydrological storage potential (area of wetlands, which can alternatively allow water and nutrients to bypass wetlands when storage capacity is filled with water or to trap them when not filled); and …

Exploring Computational Chemistry On Emerging Architectures, David Dewayne Jenkins

Doctoral Dissertations

Emerging architectures, such as next generation microprocessors, graphics processing units, and Intel MIC cards, are being used with increased popularity in high performance computing. Each of these architectures has advantages over previous generations of architectures including performance, programmability, and power efficiency. With the ever-increasing performance of these architectures, scientific computing applications are able to attack larger, more complicated problems. However, since applications perform differently on each of the architectures, it is difficult to determine the best tool for the job. This dissertation makes the following contributions to computer engineering and computational science. First, this work implements the computational chemistry variational …

Parallel For Loops On Heterogeneous Resources, Frederick Edward Weber

Doctoral Dissertations

In recent years, Graphics Processing Units (GPUs) have piqued the interest of researchers in scientific computing. Their immense floating point throughput and massive parallelism make them ideal for not just graphical applications, but many general algorithms as well. Load balancing applications and taking advantage of all computational resources in a machine is a difficult challenge, especially when the resources are heterogeneous. This dissertation presents the clUtil library, which vastly simplifies developing OpenCL applications for heterogeneous systems. The core focus of this dissertation lies in clUtil's ParallelFor construct and our novel PINA scheduler which can efficiently load balance work onto multiple …

Dynamic Task Execution On Shared And Distributed Memory Architectures, Asim Yarkhan

Doctoral Dissertations

Multicore architectures with high core counts have come to dominate the world of high performance computing, from shared memory machines to the largest distributed memory clusters. The multicore route to increased performance has a simpler design and better power efficiency than the traditional approach of increasing processor frequencies. But, standard programming techniques are not well adapted to this change in computer architecture design.

In this work, we study the use of dynamic runtime environments executing data driven applications as a solution to programming multicore architectures. The goals of our runtime environments are productivity, scalability and performance. We demonstrate productivity by …

Structure And Dynamics Of High Temperature Superconductors, Jennifer Lynn Niedziela

Doctoral Dissertations

High temperature superconductivity in iron based compounds has presented a series of complex problems to condensed matter physics since being discovered in 2008. The stalwart basis of condensed matter physics is the “strength in numbers" aspect of crystalline periodicity. Perfect crystalline periodicity has made possible the reduction of the questions of structural and electronic properties to single dimensions, increasing the tractability of these problems. Nevertheless, modern complex materials stretch these assumptions to their limits, and it is at this point where our work starts. Using neutron and x-ray scattering, we have conducted a series of studies on the structural disorder …

Development Of A Novel Technique For Predicting Tumor Response In Adaptive Radiation Therapy, Rebecca Marie Seibert

Doctoral Dissertations

This dissertation concentrates on the introduction of Predictive Adaptive Radiation Therapy (PART) as a potential method to improve cancer treatment. PART is a novel technique that utilizes volumetric image-guided radiation therapy treatment (IGRT) data to actively predict the tumor response to therapy and estimate clinical outcomes during the course of treatment. To implement PART, a patient database containing IGRT image data for 40 lesions obtained from patients who were imaged and treated with helical tomotherapy was constructed. The data was then modeled using locally weighted regression. This model predicts future tumor volumes and masses and the associated confidence intervals based …

Refractive Index Chemical Sensing With Noble Metal Nanoparticles, Phillip Blake

Graduate Theses and Dissertations

Chemical sensing is a key component in modern society, especially in engineering applications. Because of their widespread impact, improvements to chemical sensors are a significant area of research. One class of sensors, plasmonic sensors, is being heavily researched because of their ability to detect low levels of analyte in near real time without destroying the analyte. This work studies a new class of plasmonic sensor that utilizes diffractive coupling to improve sensor performance. Specifically, this work outlines the first study of diffractive coupling sensors with typical nanoparticle shapes. Sensitivity of this new class of sensor is directly compared to typical …

Hardware-Software Co-Design, Acceleration And Prototyping Of Control Algorithms On Reconfigurable Platforms, Desta Kumsa Edosa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Differential equations play a significant role in many disciplines of science and engineering. Solving and implementing Ordinary Differential Equations (ODEs) and partial Differential Equations (PDEs) effectively are very essential as most complex dynamic systems are modeled based on these equations. High Performance Computing (HPC) methodologies are required to compute and implement complex and data intensive applications modeled by differential equations at higher speed. There are, however, some challenges and limitations in implementing dynamic system, modeled by non-linear ordinary differential equations, on digital hardware. Modeling an integrator involves data approximation which results in accuracy error if data values are not considered …

Design Of A Pretreatment And Enzymatic Saccharification Scheme Of Understory From Managed Pine Forest For A Biochemical-Refinery Platform: The Example Of The Sweetgum Tree, Angele Djioleu

Graduate Theses and Dissertations

The possibility of using sweetgum from southern pine dominated forests as a biobased refinery feedstock was investigated. First, a baseline hydrolysis scheme for sweetgum wood and bark was designed. Sweetgum wood and bark were pretreated with 0.98% (v/v) sulfuric acid at 140°C for 30, 40, 50, 60 or 70 min and at 160°C for 30, 40, 50 or 60 min. The water insoluble solid (WIS) fraction was hydrolyzed with a cellulase enzyme cocktail. Results showed that maximum xylose and glucose yields from the wood were 82 and 86%, respectively. Similarly, the respective maximum yields of xylose and glucose from the …

A Watershed Scale Evaluation Of Selected Second Generation Biofeedstocks On Water Quality, Gurdeep Singh

Graduate Theses and Dissertations

This study compares a novel simulation approach to the conventional Soil and Water Assessment Tool (SWAT) modeler's approach for targeting biofuel crop production on marginal lands. In conventional SWAT modeling approach, non-spatial definition of hydrological response units (HRUs) results in the simulation of biofuel crops on both marginal and non-marginal land. This study provides an alternative approach in which a marginal-land raster was integrated into the land use and land cover (LULC) raster in such a way that the land uses were divided into marginal and non-marginal components. This modified LULC was used for model setup which resulted in marginal …

Plasmonic And Photonic Designs For Light Trapping In Thin Film Solar Cells, Liming Ji

Graduate Theses and Dissertations

Thin film solar cells are promising to realize cheap solar energy. Compared to conventional wafer cells, they can reduce the use of semiconductor material by 90%. The efficiency of thin film solar cells, however, is limited due to insufficient light absorption. Sufficient light absorption at the bandgap of semiconductor requires a light path more than 10x the thickness of the semiconductor. Advanced designs for light trapping are necessary for solar cells to absorb sufficient light within a limited volume of semiconductor. The goal is to convert the incident light into a trapped mode in the semiconductor layer.

In this dissertation, …

Investigation Of Heat Transfer And Flow Using Ribs Within Gas Turbine Blade Cooling Passage: Experimental And Hybrid Les/Rans Modeling, Sourabh Kumar

Theses and Dissertations

Gas turbines are extensively used for aircraft propulsion, land based power generation and various industrial applications. Developments in innovative gas turbine cooling technology enhance the efficiency and power output, with an increase in turbine rotor inlet temperatures. These advancements of turbine cooling have allowed engine design to exceed normal material temperature limits. For internal cooling design, techniques for heat extraction from the surfaces exposed to hot stream are based on the increase of heat transfer areas and on promotion of turbulence of the cooling flow. In this study, it is obtained by casting repeated continuous V and broken V shaped …

Pulse Sharpening Effects Of Thin Film Ferroelectric Transmission Lines, Robert J. Sleezer

Graduate Theses and Dissertations

Advances in material science have resulted in the development of electrically nonlinear high dielectric thin film ferroelectrics, which have led to new opportunities for the creation of novel devices. This dissertation investigated one such device: a low voltage nonlinear transmission line (NLTL). A finite element simulation of ferroelectric transmission lines showed that NLTLs are capable of creating shockwaves. Additionally, if the losses are kept sufficiently low, it was shown that voltage gain should be possible. Furthermore, a method of accounting for material dispersion was developed. Results from simulations including material dispersion showed that temporal solitons might be possible from a …

Synthesis And Characterizations Of Pyridinium Salts Including Poly(Pyridinium Salt)S And Their Applications, Tae Soo Jo

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pyridinium salts, both molecular and polymeric, are an interesting class of multifunctional materials that exhibit liquid-crystalline and light-emitting properties. Moreover, their properties can be easily tuned by introducing new types of anions or by modifying their chemical structures. This dissertation describes synthesis and characterization of poly(pyridinium salt)s containing macrocounterions and fluorene moieties in their backbones, synthesis and characterization of nanocomposites of poly(pyridinium salt)s with single-walled carbon nanotubes via non-covalent interactions, and synthesis and characterizations of pyridinium salts having different aliphatic linkages and their application in organic acid sensing.

First, all of these ionic polymers were prepared by either ring-transmutation or …

Comparison And Simulation Of Salt-Ceramic Composites For Use In High Temperature Concentrated Solar Power, Lauren Michelle Fossile

UNLV Theses, Dissertations, Professional Papers, and Capstones

Due to the inherently intermittent nature of solar energy caused by cloud cover among other sources, thermal storage systems are needed to make solar energy more consistent. This same technology could be used to prolong the daily number of useful hours of solar energy power plants. Salt-ceramic materials are a relatively new prospect for heat storage, but have been researched mostly with magnesium oxide and several different carbonate salts. Salt ceramics are a phase change material where the salt changes phase inside the ceramic structure allowing for the system to use the sensible heat of both materials and the latent …

Validation Of Weak Form Thermal Analysis Algorithms Supporting Thermal Signature Generation, Elton Lewis Freeman

Masters Theses

Extremization of a weak form for the continuum energy conservation principle differential equation naturally implements fluid convection and radiation as flux Robin boundary conditions associated with unsteady heat transfer. Combining a spatial semi-discretization via finite element trial space basis functions with time-accurate integration generates a totally node-based algebraic statement for computing. Closure for gray body radiation is a newly derived node-based radiosity formulation generating piecewise discontinuous solutions, while that for natural-forced-mixed convection heat transfer is extracted from the literature. Algorithm performance, mathematically predicted by asymptotic convergence theory, is subsequently validated with data obtained in 24 hour diurnal field experiments for …

Hybrid Plasmonic Nanoantennas: Fabrication, Characterization, And Application, Shengjie Zhai

UNLV Theses, Dissertations, Professional Papers, and Capstones

As optical counterpart of microwave antennas, plasmonic nanoantennas are important nanoscale devices for converting propagating optical radiation into confined/enhanced electromagnetic fields. Presently, nanoantennas, with a typical size of 200-500 nm, have found their applications in bio-sensing, bio-imaging, energy harvesting, and disease cure and prevention. With the device feature size of next generation IC goes down to 22 nm or smaller, and biological/chemical sensing reaches the Gene’s level, the sizes of the corresponding nanoantennas have to be scaled down to sub-100nm level. In the literature, these sub-100nm nanoantennas are referred as deep subwavelength nanoantennas as size of such miniaturized nanoantennas is …

Investigating The Impacts Of Conventional And Advanced Treatment Technologies On Energy Consumption At Satellite Water Reuse Plants, Jonathan Roy Bailey

UNLV Theses, Dissertations, Professional Papers, and Capstones

With the ever increasing world population and the resulting increase in industrialization and agricultural practices, depletion of two of the world's most important natural resources, water and fossil fuels, is inevitable. Water reclamation and reuse is the key to protecting these natural resources. Water reclamation using smaller decentralized wastewater treatment plants, known as satellite water reuse plants (WRP), have become popular in the last decade. With stricter standards and regulations on effluent quality and requirements for a smaller land footprint (i.e. real estate area), additional treatment processes and advanced technologies are needed. This greatly increases the energy consumption of an …

Novel Production Techniques Of Radioisotopes Using Electron Accelerators, Daniel Robert Lowe

UNLV Theses, Dissertations, Professional Papers, and Capstones

Non-traditional radioisotope production techniques using a compact, high power linear electron accelerator have been demonstrated and characterized for the production of 18F, 47Sc, 147Pm, and 99mTc from a variety of target candidates. These isotopes are used extensively in the medical field as diagnostic and therapy radioisotopes, as well as the space industry as RTG's. Primary focus was placed on 99mTc as it constitutes approximately 80% of all diagnostic procedures in the medical community that use radioactive tracers. It was also the prime focus due to recent events at the Chalk River nuclear reactor, which caused global shortages of this isotope …

Post Processing Of Optically Recognized Text Using First Order Hidden Markov Model, Spandana Malreddy

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, we report on our design and implementation of a post processing system for Optically Recognized text. The system is based on first order Hidden Markov Model (HMM). The Maximum Likelihood algorithm is used to train the system with over 150 thousand characters. The system is also tested on a file containing 5688 characters. The percentage of errors detected and corrected is 11.76% with a recall of 10.16% and precision of 100%

The Impact Of Advanced Wastewater Treatment Technologies And Wastewater Strength On The Energy Consumption Of Large Wastewater Treatment Plants, Timothy Stephen Newell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Wastewater treatment is an energy intensive process often requiring the use of advanced treatment technologies. Stricter effluent standards have resulted in an increase in the number of wastewater treatment plants (WWTPs) with advanced treatment over time. Accordingly, associated energy consumption has also increased. Concerns about lowering operating costs for WWTPs and reducing associated greenhouse gas generation present an incentive to investigate energy use in WWTPs. This research investigated the impact of wastewater strength and the introduction of advanced treatment technologies, to replace traditional technologies on energy use to treat wastewater in WWTPs. Major unit processes were designed for a 100 …

Evaluation Of Tagging Techniques Gamma-Decay Probabilities Using The Surrogate Method, Timothy Lee Reed

Masters Theses

A detailed analysis of the statistical and discrete [gamma]-decay tagging techniques was conducted using the absolute surrogate and surrogate ratio method (SRM) to obtain the 92Mo(n,[gamma]) cross section in an equivalent neutron energy range of 80 to 880 keV. Excited 93Mo and 95Mo nuclei were populated using (d,p) reactions on 92Mo and 94Mo targets, respectively. The absolute surrogate 92Mo(n,[gamma]) cross sections disagreed with evaluated neutron capture cross section data by as much as a factor of 4 using the statistical tagging approach, whereas the discrete [gamma]-decay tag absolute surrogate cross section disagreed with the evaluated neutron capture cross section by …

Optimization Of Chiral Separation Of Nadolol By Simulated Moving Bed Technology, Nesma Nehad Hashem

Electronic Thesis and Dissertation Repository

Simulated Moving Bed (SMB) technology has gained increasing attention as one of the most powerful techniques for chromatographic separations due to its cost-effectiveness and efficiency. Application of SMB technology is especially important in the pharmaceutical industry for production of enantiopure drugs, as required under strict FDA regulations, to avoid possible adverse effects of racemic drugs. In this study, the performance of the SMB process in separation of racemic nadolol on a perphenyl carbamoylated beta cyclodextrin (β-CD) stationary phase was investigated. The equilibrium dispersive model coupled with bi-Langmuir adsorption isotherm and lumped kinetic approximation, constitute the mathematical model used to simulate …

A Gap Analysis Of Meteorological Requirements For Commercial Space Operators, Nicholas Stapleton

Doctoral Dissertations and Master's Theses

Commercial space companies will soon be the primary method of launching people and supplies into orbit. Among the critical aspects of space launches are the meteorological concerns. Laws and regulations pertaining to meteorological considerations have been created to ensure the safety of the space industry and those living around spaceports; but, are they adequate? Perhaps the commercial space industry can turn to the commercial aviation industry to help answer that question. Throughout its history, the aviation industry has dealt with lessons learned from mishaps due to failures in understanding the significance of weather impacts on operations. Using lessons from the …

The Design And Testing Of A Solar Autoclave With Broad Spectrum Sterilization Capabilities, Sarah S. Trabia

Honors College Theses

Energy is difficult to come by in developing countries and this interferes with the ability of doctors to provide good healthcare to their patients. Without decent sterilization, patients can become infected and diseases can spread throughout hospitals. This study involves designing a solar autoclave for developing countries that is as efficient as electrical autoclaves. The design is intended to not require any electrical input and to be affordable to those who cannot afford advanced medical equipment. Once the solar autoclave is designed, it will be tested to determine if it can sterilize equipment against a variety of different bacteria, including …

P3ht:Pcpdtbt:Pcbm Multi- Polymer Single Layer Solar Cells, Ted Andreas

Physics

OPV efficiencies are limited by their narrow absorption; rather than using tandem architecture to overcome this obstacle, our group combined P3HT and PCPDTBT into a single layer BHJ solar cell that achieved 2.0% PCE. This is 33% higher than the pure P3HT control from this group, proving that multi-polymer solar cells have the potential to outperform their single-polymer components.

A Novel Microfluidic Enrichment Technique For Carbonylated Proteins, Bryant C. Hollins

Doctoral Dissertations

Proteins are the building blocks of cells in living organisms, and are composed of amino acids. The expression of proteins is regulated by the processes of transcription and translation. Proteins undergo post-translational modifications in order to dictate their role physiologically within a cell.

Not all post-translational modifications are beneficial for the protein or the cell. One type of post-translational modification, called carbonylation, irreversibly places a carbonyl group onto an amino acid residue, most commonly proline, lysine, arginine, and threonine. This modification can have severe consequences physiologically, including loss of solubility, loss of function, and protein aggregation.

Carbonylated proteins have commonly …

The Factors Behind A Successful Implementation Of Electronic Health Records Systems, Anjee Gorkhali

Engineering Management & Systems Engineering Theses & Dissertations

This research explores the role that budget for Information System (IS) and technical expertise of healthcare service provider staff play on the successful leap from a partial to exhaustive implementation of Electronic Health Records (EHR) Systems. Technical expertise in Information Systems might not be easily measurable directly, but there are a number of indicators that could be used as a proxy, such as: Information System (IS) Department Budget, number of IS staff and the extent of technical trainings provided by the IS department to the clinical staff. This research study hypothesizes that quality technical trainings conducted by an IS department …

Semi-Automatic Simulation Initialization By Mining Structured And Unstructured Data Formats From Local And Web Data Sources, Olcay Sahin

Computational Modeling & Simulation Engineering Theses & Dissertations

Initialization is one of the most important processes for obtaining successful results from a simulation. However, initialization is a challenge when 1) a simulation requires hundreds or even thousands of input parameters or 2) re-initializing the simulation due to different initial conditions or runtime errors. These challenges lead to the modeler spending more time initializing a simulation and may lead to errors due to poor input data.

This thesis proposes two semi-automatic simulation initialization approaches that provide initialization using data mining from structured and unstructured data formats from local and web data sources. First, the System Initialization with Retrieval (SIR) …