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 …

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 …

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 …

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 …

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 …

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.

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 …

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 …

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 …

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.

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.

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 …

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 …

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 …

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 …

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 …

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 …

Optimal Design Of Discrete-Time Delta Sigma Modulators, Matthew Edward Jackson

UNLV Theses, Dissertations, Professional Papers, and Capstones

In this thesis, optimal signal transfer functions (STFs) and noise transfer functions (NTFs) for discrete time delta sigma (ΔΣ) modulators are determined. For a given oversampling rate (OSR), these STFs and NTFs are optimized with respect to a weighted combination of the ΔΣ modulator's signal-to-noise ratio (SNR) and dynamic range (DR). This optimization problem is solved using a novel hybrid orthogonal genetic (HOG) algorithm that uses customized genetic operators to improve algorithm performance and accuracy when applied to multimodal, non-differentiable performance surfaces. To generate optimal system functions, the HOG algorithm is implemented as a constrained global optimizer to minimize cost …

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 …

Experimental And Numerical Study Of A Proton Exchange Membrane Electrolyzer For Hydrogen Production, Sachin S. Deshmukh

UNLV Theses, Dissertations, Professional Papers, and Capstones

Hydrogen as a fuel source has received attention from researchers globally due to its potential to replace fossil based fuels for energy production. Research is being performed on hydrogen production, storage and utilization methods to make its use economically feasible relative to current energy sources. The PEM electrolyzer is used to produce hydrogen and oxygen using water and electricity. Focus of our study is to provide a benchmark experiment and numerical model of a single cell electrolyzer that can assist in improving the current state of understanding of this system. Parametric analysis of an experimental cell was performed to understand …

Effects Of Mechanical And Metallurgical Variables On Creep, Fracture Toughness And Crack Growth Behavior Of Alloy 617, Muhammad Hasibul Hasan

UNLV Theses, Dissertations, Professional Papers, and Capstones

Nickel base Alloy 617 has been identified to be a suitable structural material for heat exchanger applications in both hydrogen and electricity generation using nuclear heat. A maximum operating temperature of 950°C has been specified by department of energy (DOE) for both applications to achieve a maximum possible efficiency. Therefore, an extensive investigation has been pursued to evaluate time-dependent-deformation (Creep) of this alloy as functions of temperature and applied load. The results indicate that this alloy exhibited severe creep deformation, characterized by development of an instantaneous tertiary creep region at 850 and 950°C under applied stresses corresponding to its 35% …

Extents And Limits Of Radioscopic Detection Of Nuclear Materials In Cargo Containers With Two Megavoltage Energy Barriers, Vijay Kumar Mandava

UNLV Theses, Dissertations, Professional Papers, and Capstones

The megavoltage X-ray technology is utilized for detecting nuclear materials in cargo containers. Interlaced response is obtained by switching rapidly between 6MeV and 9 MeV beams. It is known that the ratio of penetration levels of cargo contents taken at nominal and dual energies provides the information about atomic numbers of materials, and thus can also indicate the threat group. However, the identification is not straightforward if combinations of materials are present. The latter can lead to misdetections. It is imperative to know what are the extent and the limit of the currently employed technology, and how to carry out …

Design And Characterization Of A Shock And Vibration Mitigation Seat System, George Samaan Ladkany

UNLV Theses, Dissertations, Professional Papers, and Capstones

Extensive research has been conducted into the development of pneumatic seatbladder systems for shock and vibration mitigation for use in current U.S military vehicle envelopes. This research expands on the previous work through an elaborate experimental characterization of four prototype air bladder seat cushion systems. The experimental characterization conducted included shock testing, continuous vibration, and internal dynamic pressure measured during the shock event.

The shock testing was conducted both at the Army Research Lab as well at UNLV. The shock testing conducted at UNLV was performed on a drop tower designed and constructed during the time of this research. The …

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 …

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 …

Update To Ansi/Ans-6.4.3-1991 For Low-Z And Compound Materials And Review Of Particle Transport Theory, Luis Durani

UNLV Theses, Dissertations, Professional Papers, and Capstones

The ANSI/ANS-6.4.3-1991 Gamma-Ray Attenuation Coefficients and Buildup Factors for Engineering Materials Standard (herein known as ANS Standard), contains derived gamma-ray attenuation coefficients and buildup factors for selected engineering materials and elements for use in shielding calculations (ANSI/ANS-6.1.1, 1991). The current status of the ANS Standard is withdrawn due to the lack of any updates since its last publication. Since the last update of the ANS standard, more accurate codes for particle transport and cross sectional data have become available. As a result, this study was carried out to update gamma-ray buildup factors for iron and water as a function of …

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 …

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, …

Performance Evaluation Of Network-On-Chip Interconnect Architectures, Xinan Zhou

UNLV Theses, Dissertations, Professional Papers, and Capstones

With a communication design style, Network-on-Chips (NoCs) have been proposed as a new Multi-Processor System-on-Chip paradigm. Simulation and functional validation are essential to assess the correctness and performance of the NoC design. In this thesis, a cycle-accurate NoC simulation system in Verilog HDL is developed to evaluate the performance of various NoC architectures. First, a library of NoC components is developed based on an existing design. Each NoC architecture to be evaluated is constructed from the library according to the topology description which specifies the network topology, network size, and routing algorithm. The network performance of four NoC architectures under …