Engineering Commons^™

Seismic Evaluation Of Clark County Critical Bridges Using Nonlinear Static Procedures, Ahmad Said Saad

UNLV Theses, Dissertations, Professional Papers, and Capstones

Bridges are vital connective elements in community transportation systems. In the past, bridges have been severely damaged by earthquakes. However, with proper mitigation techniques, such as bridge retrofit, severe earthquake damage to bridges can be avoided. Since the 1970’s, design codes underwent major changes with regard to seismic analysis and design provisions of structures and bridges. Meanwhile, one third of the nation’s 600,000 inventoried highway bridges are considered as either structurally deficient or functionally obsolete.

This study is a part of the “Earthquakes in Southern Nevada” project. Earlier in this project, buildings and bridges in southern Nevada were studied in …

Design Of A "Figure-8" Spherical Motion Flapping Wing For Miniature Uav's, Zohaib Parvaiz Rehmat

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hummingbirds and some insects exhibit a Figure-8 motion, which allows them to undergo variety of maneuvers including hovering. It is therefore desirable to have flapping wing miniature air vehicles (FWMAV) that can replicate this unique wing motion. In this research, a design of a flapping wing for FWMAV that can mimic Figure-8 motion using a spherical four bar mechanism is presented. To produce Figure-8 motion, the wing is attached to the coupler point of the spherical four bar mechanism and driven by a DC servo motor. For verification of the design, a prototype of the wing and mechanism is fabricated …

Evaluation Of Low-Temperature Fluoride Routes To Synthesize Actinide Nitrides And Oxide Solid Solutions, Gunanda Waduge Chinthaka Silva

UNLV Theses, Dissertations, Professional Papers, and Capstones

Actinide mononitrides have been considered as a possible nuclear fuel for the Generation-IV nuclear reactor systems. In the process of evaluating these actinide mononitrides as nuclear fuel, it is important to study different chemical and physical characteristics of these compounds. Synthesis of the materials is thus important. Carbothermic reduction is one of the techniques that have been used to synthesize actinide mononitrides. In this method, a mixture of actinide oxide such as UO ₂ and excess carbon is heat treated at temperatures greater than 1700 °C under a nitrogen atmosphere. The technique is however not promising in synthesizing the actinide …

An On-Sun Parametric Study Of Solar Hydrogen Production Using Wo3 Photoanodes, Christopher K. Halford

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solar production of hydrogen using photoactive electrodes is a topic receiving much attention in recent years. The use of thin metal oxide films as photoanodes allows the water splitting reaction to occur at a much lower applied voltage than would be necessary with a straight electrolysis process. Researchers have reported up to 18% solar to hydrogen efficiencies over short periods. The University of Nevada Las Vegas in conjunction with the UK based firm Hydrogen Solar have developed a prototype of this type of cell using a WO3 photoanode. An on-sun test facility has been constructed by the UNLV Center …

Design And Fabrication Of A Small Prototype Airframe Structure, Kimberly Lynn Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

This project called for a first-generation prototype aircraft with hovering capabilities that was lightweight. The focus of this study was to design a small low-cost prototype composite airframe that meets specified requirements, analyze structures using finite element analysis and mechanical testing, and construct a prototype using proven composite manufacturing techniques. One fuselage, one wing, and several engine nacelles were designed and fabricated. Several design and fabrication methods and materials were analyzed, with focus given to the nacelles, and recommendations were provided for the manufacture of the first generation airframe based on time, weight, and cost.

Investigation Of Feasibility And Potential Mechanisms For The Bioregeneration Of Perchlorate Laden Gel-Type Anion Exchange Resin, Arjun Krishna Venkatesan

UNLV Theses, Dissertations, Professional Papers, and Capstones

The feasibility and potential mechanisms for the bioregeneration of perchlorate laden gel-type anion exchange resin were investigated in this study. Bioregeneration is a sustainable process when compared to one time use of resin and disposal by incineration. Batch and bench-scale bioregeneration experiments were performed to evaluate the feasibility of the process and to gain insight into potential mechanisms that control gel-type resin bioregeneration. The results of the bioregeneration tests suggested that the initial phase of the bioregeneration process is controlled by kinetics, while the later phase is controlled by diffusion. Higher perchlorate load in the resin had a positive effect …

Low Power Fft Processor Design Considerations For Ofdm Communications, David Layne Rushforth

UNLV Theses, Dissertations, Professional Papers, and Capstones

Today's emerging communication technologies require fast processing as well as efficient use of resources. This project specifically addresses the power-efficient design of an FFT processor as it relates to OFDM communications such as cognitive radio. The Fast Fourier Transform (FFT) processor is what enables the efficient modulation in OFDM. As the FFT processor is the most computationally intensive component in OFDM communication, the power efficiency improvement of this component can have great impacts on the overall system. These impacts are significant considering the number of mobile and remote communication devices that rely on limited battery-powered operation. This project explores current …

Text Categorization Based On Apriori Algorithm's Frequent Itemsets, Prathima Madadi

UNLV Theses, Dissertations, Professional Papers, and Capstones

Automatic Text categorization is the task of assigning an electronic document to one or more categories, based on its contents. There are many known techniques to efficiently solve categorization problems. Typically these techniques fall into two distinct methodologies which are either logic based or probabilistic. In recent years, many researchers have tried approaches which area hybrid of these two methodologies.

In this thesis, we deal with document categorization using Apriori Algorithm. The Apriori algorithm was initially developed for data mining and basket analysis applications in the relational databases. Although the technique is logic based, it also relies on the statistical …

Experimental Evaluation And Modeling Of Engine Driven Heat Pump, Isaac Y. Mahderekal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Recently, the Gas Engine-Driven Heat Pump (GHP) System has become an economic choice and more attractive climate control system than the conventional air conditioner due to its advantage in reducing fossil fuel consumption and environmental pollution. The GHP is a new type of heat pump in which the compressor (the core part) is driven by a gas engine. The GHP typically uses the work produced by the engine to drive a vapor-compression heat pump. At the same time, the waste heat rejected by the engine is used for heating purposes.

To improve the system performance of the GHP, a numerical …

Investigation Of Magnetic Resonance Imaging And Spectroscopy For The Detection Of Breast Cancer, Robert Thomas Etnire

UNLV Theses, Dissertations, Professional Papers, and Capstones

Magnetic resonance imaging (MRI) of the breast offers an alternative to screening mammography which may benefit those women at high risk for breast cancer, women under the age of 40, and those with dense breast tissue. One concern with MRI is the number of high false positives. Coupling MRI with magnetic resonance spectroscopy(MRS) may lower the number of false positives, and thus improve the diagnostic capabilities of MRI for the clinician. MRS for breast imaging focuses on the total choline containing compounds in the spectra in the suspected breast lesion to analyze areas of concern. The results of the study …

Anti-Islanding Schemes For Machine-Based Distributed Generation, Temesgen Tadegegn

UNLV Theses, Dissertations, Professional Papers, and Capstones

The most common method of detecting the islanding in a machine-based distributed generator (DG) is to establish an under/over frequency and under/over voltage window within which a synchronous DG is allowed to operate. When such a DG is islanded from the utility system, the frequency or voltage will quickly move outside the operating window if there is a sufficient difference between the local load and DG power generation level. However, there is a possibility that the system voltage and frequency will be maintained within the specified limits following loss of the grid in cases where the load and generator are …

Human Identification Using Pyroelectric Infrared Sensors, Aron E. Suppes

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of this thesis is to discuss the viability of using pyroelectric infrared (PIR) sensors as a biometric system for human identification.

The human body emits infrared radiation, the distribution of which varies throughout the body, and depends upon the shape and composition of the particular body part. A PIR sensor utilizing a Fresnel lens will respond to this infrared radiation. When a human walks, the motion of the body's individual components form a characteristic gait that is likely to affect a PIR sensor field in a unique way.

A statistical model, such as a Hidden Markov Model, could …

Modulated Nanopores Using Pulse Anodization On Thin Aluminum, Mahesh Babu Gunukula

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nanoporous anodic aluminum oxide has traditionally been made in one of two ways: "Mild Anodization (MA)" or "Hard Anodization (HA)". The former method produces self-ordered pore structures but it is slow and only works for a narrow range of processing conditions; the latter method, which is widely used in the aluminum industry, is faster but it produces films with disordered pore structures. Here we report a novel approach termed "pulse anodization" that combines the advantages of the MA and HA processes. By designing the pulse sequences it is possible to control both the composition and pore structure of the anodic …

Magnetic Sensors For Biodetection, Pranjali Vineet Sneha Deshpande

UNLV Theses, Dissertations, Professional Papers, and Capstones

The objective of thesis is to design magnetic sensor for detection of nanoparticles. Recently integrating the standard laboratory techniques into integrated system on chip is growing attention. Recent development is to combine magnetic markers and magnetoresistive sensors together in magnetic chip. In this thesis two magnetoresistive sensors were studied and designed.

By applying magnetic fields, magnetic nanoparticles can be manipulated on-chip, which can be utilized to pull the molecules to specific binding sites or to test the binding strength and distinguish between specifically and non-specifically bound molecules

Magnetoresistive sensors are compatible with the semiconductor industry which provides electronic signal directly …

The Influence Of Carbon Source Types And Nitrate On The Performance Of The Enhanced Biological Phosphorus Removal Systems, Shamim Ara Begum

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research focuses on two issues in enhanced biological phosphorus removal (EBPR). The first issue encompasses the effect of the type of carbon sources (i.e. volatile fatty acids and non volatile fatty acids) on the microbiology of EBPR. The second issue deals with the influence of denitrification on EBPR. Few studies have been performed to investigate these two issues. The recent findings on these areas are summarized below to establish the knowledge gaps this dissertation attempted to address. Details on the specific findings can be found in the literature review portion of this proposal.

Biology-Inspired Adaptive And Nonlinear Robust Control Of Bauv Using Pectoral-Like Fins, Subramanian Ramasamy

UNLV Theses, Dissertations, Professional Papers, and Capstones

Aquatic animals have splendid ability to move smoothly through water using variety of oscillating fins. Presently researchers are involved in developing biorobotic autonomous underwater vehicles (BAUVs) which have the ability to swim like marine animals. Multiple oscillating fins (dorsal, caudal, pectoral, pelvic, etc.) can be mounted on BAUVs to generate control forces for propulsion and maneuvering. In this research work, control of the BAUVs using pectoral fins alone is considered. The oscillating pectoral fins produce unsteady periodic forces. The control of motion of an BAUV in yaw and dive planes are considered.

Turn Constrained Path Planning Problems, Victor M. Roman

UNLV Theses, Dissertations, Professional Papers, and Capstones

We consider the problem of constructing multiple disjoint paths connecting a source point s to a target point t in a geometric graph. We require that the paths do not have any sharp turn angles. We present a review of turn constrained path planning algorithms and also algorithms for constructing disjoint paths. We then combine these techniques and present an O(nlogn) time algorithm for constructing a pair of edge disjoint turn constrained paths connecting two nodes in a planar geometric graph. We also consider the development of a turn constrained shortest path map in the presence of …

System Architecture For An Intelligent Implantable Bio-Telemetry Device, Karthik Kumar Nattamai Kumaresan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Biotelemetry has long been used for environmental and life science research to study animal populations and behavior. The use of implantable bio-telemetric techniques makes it possible to record and study physiological variables during long-term experiments with a minimum disturbance to the animal. Fully implantable telemetric techniques greatly reduce the risk of infection associated with leads and catheters protruding from the skin. In this research the design and implementation of a completely programmable bio-implantable digital system which can measure two physiological signals extended over a period of time is considered. The proposed system consists of a standalone implantable transmitter unit and …

Individual Copper Nanowire Decorated By Gold Nanoparticles For Surface Enhanced Raman Scattering, Roshan Guttikonda

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this Thesis, I discuss the theory, implementation and applications of Surface enhanced Raman scattering (SERS). Surface enhanced Raman scattering has been used to detect 4 mercaptopyridine molecules. On a Silicon wafer, Gold nanoparticles are deposited onto Copper nanowires. Hotspots occur at the small gap (less than 10nm) between the nanowire and nanoparticle. The interaction of the electromagnetic field of the incident laser and the surface plasmon resonances of the metal nanoparticles at the hot spots enhances the Raman scattering signal of the adsorbed pyridine molecule (10 -3 M ). The dependence of SERS signal on the polarization angle of …

Two-Tank Indirect Thermal Storage Designs For Solar Parabolic Trough Power Plants, Joseph E. Kopp

UNLV Theses, Dissertations, Professional Papers, and Capstones

The performance of a solar thermal parabolic trough plant with thermal storage is dependent upon the arrangement of the heat exchangers that ultimately transfer energy from the sun into steam. The steam is utilized in a traditional Rankine cycle power plant. The most commercially accepted thermal storage design is an indirect two-tank molten salt storage system where molten salt interacts with the solar field heat transfer fluid (HTF) through a heat exchanger. The molten salt remains in a closed loop with the HTF and the HTF is the heat source for steam generation. An alternate indirect two tank molten salt …

Spectroscopic Investigation Of Palladium-Copper Bimetallic Systems For Pem Fuel Cell Catalysts, Timo Hofmann

UNLV Theses, Dissertations, Professional Papers, and Capstones

One of the main barriers to commercialization of polymer electrolyte membrane fuel cells systems is cost, which is largely due to the need of platinum (Pt)-containing catalysts. In this thesis we investigate bimetallic systems consisting of a base metal (copper) and a noble metal (palladium) that, as an alloy on the nanoscale, mimic the electronic properties that make Pt desirable as a catalyst.

We present a detailed investigation of the electronic structure of carbon-supported Pd/Cu nanoparticle catalysts, model bilayer thin film systems, alloys, and various metal reference samples. We have investigated the valence band structure of the catalysts using a …

Substituent Effect On The Electronic And Assembling Properties Of Asymmetric Phenazine Derivatives, Bin Cao

UNLV Theses, Dissertations, Professional Papers, and Capstones

Currently, one-dimensional (1-D) nanostructures have drawn much interest because of their potential applications for nanoscale optoelectronic devices. Self-assembly (SA) based on π-conjugated systems through various intermolecular interactions has been widely used to produce 1-D nanostructure. Morphology of the assembled structures can be modified by incorporating substituents, which provide additional secondary interactions. Meanwhile, those substituents also influence the electronic properties of the molecules. Previous studies have made little effort to systematically study subsistent effects on both electronic and SA properties.

The primary objective of this research is to generate controllable 1-D structures through SA, and to provide a fundamental understanding of …

Novel Techniques In Iris Recognition, David Walker

UNLV Theses, Dissertations, Professional Papers, and Capstones

Using Daugman's algorithm and comparable alternatives, we find that we are able to identify an iris with as little as less than half of the iris information available, and an equal error rate comparable with that of popular biometrics like the fingerprint and face recognition biometrics. Different experiments were done based on percentage of iris shown, the resolution of the iris, and the position of the iris covered to determine if partial iris recognition is a viable biometric. It was found after over 500,000 different iris comparisons amongst five different experiments that regardless of the model used and the resolution, …

Study Of Corrosion Of Materials In The Sulfur-Iodine Hydrogen Production Cycle, Thao Trung Ho

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen is of great interest since the availability of traditional fossil fuels is in decline. Strictly speaking, hydrogen is not a primary source of energy but is an energy carrier, since energy typically must be used from another source (electricity, natural gas, coal, etc.) to produce it. Of hydrogen production techniques, the Sulfur-Iodine thermochemical water splitting process (S-I cycle), which was proposed by General Atomics (GA), is promising with its simplicity and high efficiency. Most of the chemicals are recycled except water. However, the S-I cycle operates in a harsh, corrosive environment in the presence of a mixture of iodine …

Effect Of Mechanical Vibrations On Light Emitting Diode Luminaires, Jayalakshmi Paladugu

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this work, a LED and two types of Compact fluorescent lamps were investigated for the intensity variation due to mechanical vibrations in the range of 0 to 30 HZ. In general, subjecting the lamps to 24-hour vibration affects the total intensity percentage variations of peak intensities after vibrations is in the range of -25 to +15% compared to those of no vibrations for the light emitting diode luminaires. For the case of compact fluorescent lamps (Nuvue) the variations are in range from +10 to +35%, whereas for the Compact fluorescent lamps (Ecosmart) the intensity peaks range from -10 to …

Fracture Toughness, Crack-Growth-Rate And Creep Studies Of Alloy 276, Joydepp Pal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Austenitic nickel-base Alloy 276 had been proposed to be a candidate structural material within the purview of the nuclear hydrogen initiative program. A mechanistic understanding of high temperature tensile deformation of this alloy has already been presented in an earlier investigation. The current investigation has been focused on the evaluation of crack-growth behavior, fracture toughness, stress-corrosion-cracking and creep deformation of this alloy as functions of different metallurgical and mechanical variables. The results of crack-growth study under cyclic loading indicate that this alloy exhibited greater cracking tendency with increasing temperature at a constant load ratio (R). However, the effect of temperature …

Zirconia-Magnesia Inert Matrix Fuel And Waste Form: Synthesis, Characterization And Chemical Performance In An Advanced Fuel Cycle, Kiel Steven Holliday

UNLV Theses, Dissertations, Professional Papers, and Capstones

There is a significant buildup in plutonium stockpiles throughout the world, because of spent nuclear fuel and the dismantling of weapons. The radiotoxicity of this material and proliferation risk has led to a desire for destroying excess plutonium. To do this effectively, it must be fissioned in a reactor as part of a uranium free fuel to eliminate the generation of more plutonium. This requires an inert matrix to volumetrically dilute the fissile plutonium. Zirconia-magnesia dual phase ceramic has been demonstrated to be a favorable material for this task. It is neutron transparent, zirconia is chemically robust, magnesia has good …

Oxidation Modeling By Means Of Molecular Dynamics, Chaiyod Soontrapa

UNLV Theses, Dissertations, Professional Papers, and Capstones

Oxidation modeling is normally engineered to study systems at macroscopic scales, mostly in analytical forms based on diffusion theories. The associated time scale is usually in months, days, or minutes, and the length scale is in the order of microns. In this dissertation, oxidation modeling is performed at atomistic scale with the time and length scales in picoseconds and angstroms, respectively, using molecular dynamics. Molecular dynamics simulations generate trajectories of each atom or particle in a system according to the laws of physics. Studying oxidations under the atomistic point of view can offer new insights on atomic behaviors and influencing …

Analysis And Design Of Low Power Cmos Ultra Wideband Receiver, Abdul Bhuiyan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research concentrates on the design and analysis of low power ultra wideband receivers for Multiband Orthogonal Frequency Division Multiplexing systems. Low power design entails different performance tradeoffs, which are analyzed. Relationship among power consumption, achievable noise figure and linearity performance including distortion products (cross-modulation, inter-modulation and harmonic distortion) are derived. From these relationships, circuit design proceeds with allocation of gain among different sub circuit blocks for power optimum system.

A power optimum RF receiver front-end for MB-OFDM based UWB systems is designed that covers all the MB-OFDM spectrum between 3.1 GHZ to 9.6 GHZ. The receiver consists of a …

Parametric Study Of Efficiency Measures For Home Energy Conservation In Las Vegas, Nevada, Todd M. France

UNLV Theses, Dissertations, Professional Papers, and Capstones

Pulte Homes, a production home builder and community developer partnering with the U.S. Department of Energy's Building America program, has collaborated with the Center for Energy Research at the University of Nevada, Las Vegas and NV Energy, the local electric utility, on an energy conservation project in the Las Vegas Valley.

This study entails four model homes at a new development in the Summerlin community of Las Vegas, Nevada, named Villa Trieste. The home models, ranging in floor plan area from 1,487 to 1,777 square feet, have been constructed under the Environments for Living program and are LEED (Leadership in …