Engineering Commons^™

A Unifying Approach To Behavioral Coverage, Elena Sherman

School of Computing: Dissertations, Theses, and Student Research

Developing methods for validating that a program works as intended is one of the key research areas in software engineering. Ideally a program P must exhibit its expected be- havior, or property, φ on all of its inputs, i.e., P |= φ. The software engineering community has developed various program analysis approaches to assess whether P |= φ. In general, these approaches can be partitioned into dynamic and static program analysis. The former execute P on a particular input and checks that the execution conforms to φ. The latter in- terprets the code of P and check that on all …

Comparing Risk-Taking And Digit Ratio (2d:4d) In Offenders And Non-Offenders, Taja Anderson

The Plymouth Student Scientist

Offenders differ from non-offenders in their propensity to engage in risk-taking behaviour. The ratio of the index and ring fingers (2D:4D), a proxy of prenatal testosterone exposure, has been linked to risk-taking behaviour. The present study compared risk-taking in 45 male offenders and 66 non-offenders using the Balloon Analogue Risk Task (BART). Furthermore, it sought to determine the relationship between their 2D:4D ratios and risk-taking behaviours. No significant differences were found between the two groups in their risk-taking behaviour and no significant correlations were found between 2D:4D and risk-taking in either group. These findings are discussed in relation to previous …

How Will Ocean Acidification Affect Marine Photosynthetic Organisms? A Review, Michael Jarrold

The Plymouth Student Scientist

Atmospheric carbon dioxide is increasing year on year, mainly as a result of burning fossil fuels. Although carbon dioxide dissolves in the oceans, mitigating atmospheric effects, it does result in a reduction of the alkalinity of sea water; an effect termed Ocean Acidification (OA). The subsequent changes in carbon chemistry will most likely affect marine photosynthetic organisms in a number of ways; including the ability of organisms to build calcium carbonate shells or skeletons (calcification) and primary production. Previous work indicates that both processes respond to OA, but not always in the same way. Consequently the aim of this review …

Investigating Placebo Mechanisms: Could A Pdp System Exist?, Francesca Payne

The Plymouth Student Scientist

Placebo mechanisms are a neglected area of research. Kirsch’s (1985) response expectancy theory described the stimulus-placebo response process as direct and unmediated. However, Hyland (2011) argued that the placebo effect is mediated by a parallel distributed processing (PDP) system, whereby all cognitive input is processed simultaneously, resulting in perseveration of the placebo effect. The present study examined this theory by utilising a TENS device as a placebo ‘effecting’ reaction times to a computer task, with an additional cognitive load task to further test the PDP system’s existence. Although a general placebo effect was found that increased in the cognitive load …

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 …

Adaptive Local And Global Synchronization And Phase Control Of Inferior Olive Neurons (Ions), Srujan Kumar Chalike

UNLV Theses, Dissertations, Professional Papers, and Capstones

Clusters of inferior olive neurons (IONs) in the olive-cerebellar system play an important role in providing synchronized motor control signals for the activation of large number of muscles. However, the dynamics of IONs are highly nonlinear and the system parameters are assumed to be unknowm. The IONs evolving from arbitrary initial conditions are not synchronized. However the application of IONs for control of BAUV's requires that IONs oscillate in unison. The objective is to design control laws such that the controlled ION tracks the trajectories of the reference ION. The two control laws are derived based on tuning functions adaptive …

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 …

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 …

Hardware Implementation Of Processor Allocator For Mesh Connected Chip Multiprocessors, Rana Sangram Reddy Marri

UNLV Theses, Dissertations, Professional Papers, and Capstones

The advancements in the semiconductor process technology and the current demand for highly parallel computing has led to the advent of Chip Multiprocessors (CMPs). CMP is the integration of two or more independent processor cores, which can read and execute program instructions, on to a single integrated circuit die. CMPs are the main computing platforms for research and development in parallel and high performance computing environments. They offer minimum inter-core communication latencies as the processor cores are present on a single chip.

The Operating System (OS) plays a key role in using a CMP effectively. The OS should support a …

Functional Classification Of Skeletal Muscle Networks. I. Normal Physiology, Yu Wang, John Winters, Shankar Subramaniam

Biomedical Engineering Faculty Research and Publications

Extensive measurements of the parts list of human skeletal muscle through transcriptomics and other phenotypic assays offer the opportunity to reconstruct detailed functional models. Through integration of vast amounts of data present in databases and extant knowledge of muscle function combined with robust analyses that include a clustering approach, we present both a protein parts list and network models for skeletal muscle function. The model comprises the four key functional family networks that coexist within a functional space; namely, excitation-activation family (forward pathways that transmit a motoneuronal command signal into the spatial volume of the cell and then use Ca …

The Development And Packaging Of A High-Density, Three-Phase, Silicon Carbide (Sic) Motor Drive, Jared Hornberger

Graduate Theses and Dissertations

Technology advances within the power electronics field are resulting in systems characterized by higher operating efficiencies, reduced footprint, minimal form factor, and decreasing mass. In particular, these attributes and characteristics are being inserted into numerous consumer applications, such as light-emitting diode lighting, compact fluorescent lighting, smart phones, and tablet PCs, to industrial applications that include hybrid, electric, and plug-in electric vehicles and more electric aircraft. To achieve the increase in energy efficiency and significant reduction in size and mass of these systems, power semiconductor device manufacturers are developing silicon carbide (SiC) semiconductor technology.

In this dissertation, the author discusses the …

Video Detection Of Trains, Michael David Forsberg

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

This thesis discusses the use of video detection as a means for train detection. It reviews works done to increase safety at and near Highway-Rail Grade Crossings (HRGCs), discusses existing and past forms of technology and methods used in train detection and arrival time prediction, and provides summaries of investigations of other detection technologies used for vehicle detection. It then goes into depth on the use of radar and video detection with Autoscope Machine Vision Processing for train detection. This thesis provides a methodology of data collection, data analyses, results, and conclusions of video detection for train detection.

Data analyses …

Development And Evaluation Of Beat Management Practices (Bmps) For Highway Runoff Pollution Control, Daniel Edward Jones

Department of Environmental Engineering: Theses and Other Student Research

As non-point source pollution, storm water runoff is one of the main contributors to stream impairment in the United States. The United States Environmental Protection Agency (USEPA) requires Municipal Separate Storm Sewer Systems (MS4s) to obtain a permit under the National Pollution Discharge Elimination System (NPDES) to manage this pollution. Many municipalities and non-traditional MS4s such as the Nebraska Department of Roads are under federal regulations that require new developments or redevelopments of a certain size to capture (and treat) runoff from all new impervious surfaces (roofs, driveways, sidewalks, and so forth) onsite, instead of allowing it to run into …

Implementation Of Magnetic Resonance Elastography For The Investigation Of Traumatic Brain Injuries, Thomas Boulet

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Magnetic resonance elastography (MRE) is a potentially transformative imaging modality allowing local and non-invasive measurement of biological tissue mechanical properties. It uses a specific phase contrast MR pulse sequence to measure induced vibratory motion in soft material, from which material properties can be estimated. Compared to other imaging techniques, MRE is able to detect tissue pathology at early stages by quantifying the changes in tissue stiffness associated with diseases. In an effort to develop the technique and improve its capabilities, two inversion algorithms were written to evaluate viscoelastic properties from the measured displacements fields. The first one was based on …

A Study Of Hdpe In High Pressure Of Hydrogen Gas: Measurement Of Permeation Parameters And Fracture Criteria, Sompong Prachumchon

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

The permeation parameters of hydrogen gas in high density polyethylene (HDPE) system are sought by comparison with a diffusion model. The method of Green’s functions is used to obtain solutions for the diffusion model. Permeation parameters are found from transient experimented data during two processes; pressurization followed by depressurization. The mechanical compression of HDPE during the pressurization process resulted in lower diffusivity coefficient values and higher solubility values. The results show that the diffusivity coefficient value in the pressurization process is 37% of that during the depressurization process. At the start of the depressurization process, a short-duration fast flow rate …

Optimization Of Nonlinear Switch Cells For Switching Converters, Bradley Alan Reese

Graduate Theses and Dissertations

Switch cells consist of an array of power switches and passive components which can replace the main switches alone in many power topologies, allowing reduced switching loss without altering the power topology directly. This thesis discusses the development of a switch cell topology that utilizes a saturable resonant inductor to reduce the size and power loss of the cell. Additionally, the cell transfers energy stored in the inductor into a capacitor for efficient energy storage during the cell's conduction region. This energy is then transferred back to the system when the cell turns off, thus reducing the total switching energy.

Capillary And Microchip Electrophoresis For The Monitoring Of Disease Causing Amyloid Proteins, Elizabeth Nancy Pryor

Graduate Theses and Dissertations

The detection of oligomers and aggregates formed by two amyloid proteins, insulin and amyloid-beta (AB), is of particular importance due to the role which these species play in Diabetes and Alzheimer's disease, respectively. However, existing techniques are limited in the ability to detect insulin and AB; oligomers due to the fact that these early aggregates are transient, present at low concentrations, and difficult to isolate. Improvements must be made to existing techniques or alternative techniques must be explored in order to identify and quantify the size of these oligomeric and aggregate species without disrupting their structure.

Capillary and microchip electrophoresis …

A Silicon Carbide Based Solid-State Fault Current Limiter For Modern Power Distribution Systems, Erik Darnell Johnson

Graduate Theses and Dissertations

The fault current limiter represents a developing technology which will greatly improve the reliability and stability of the power grid. By reducing the magnitude of fault currents in distribution systems, fault current limiters can alleviate much of the damage imposed by these events. Solid-state fault current limiters in particular offer many improved capabilities in comparison to the power system protection equipment which is currently being used for fault current mitigation. The use of silicon carbide power semiconductor devices in solid-state fault current limiters produces a system that would help to advance the infrastructure of the electric grid.

A solid-state fault …

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, …

Analysis Of Irrigation Decision Behavior And Forecasting Future Irrigation Decisions, Sanyogita Andriyas

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Farmers play a pivotal role in food production. To be economically successful, farmers must make many decisions during the course of a growing season about the allocation of inputs to production. For farmers in arid regions, one of these decisions on any given day is whether to irrigate. This research is the first of its kind to investigate the probable reasons that lead a farmer to make irrigation decisions and use those reasons/factors to forecast future irrigation decisions. This study can help water managers and canal operators to estimate short-term irrigation demands, thereby gaining information that might be useful to …

Developing A Framework To Analyze The Effect Of Mobile Technology Within A Department Of Transportation, Devin Squire

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Mobile technology has the potential to have a substantial impact on governmental agencies. In order to understand the effects of mobile technology within an agency, an analysis has to be performed. This thesis presents two mobile applications that were developed to address specific areas of concern within the Utah Department of Transportation. It then, using mobile-technology specific surveys, provides a framework for effect analysis following application implementation. This framework employs both user and developer surveys to obtain data necessary to, through statistical methods, determine either a positive or a negative application induced effect. The analysis process and survey development used …

Biodiesel Production From Mixed Culture Algae Via A Wet Lipid Extraction Procedure, Ashik Sathish

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Development of renewable sources of energy has received significant interest due to the rising costs of energy and the environmental impact of using fossil fuels. Biodiesel production from renewable sources of oil has shown promise of helping to replace or reduce dependence on petroleum based diesel thereby reducing demand for crude oil. Microalgae have been considered as a strong candidate for the production of large quantities of renewable oil for biodiesel production.

Microalgae are single cell photosynthetic organisms that posses the capability to produce renewable oil at rates much faster than land based plants and crops. In addition, microalgae can …

Closed-Loop Thrust And Pressure Profile Throttling Of A Nitrous Oxide/Hydroxyl-Terminated Polybutadiene Hybrid Rocket Motor, Zachary W. Peterson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Hybrid motors that employ non-toxic, non-explosive components with a liquid oxidizer and a solid hydrocarbon fuel grain have inherently safe operating characteristics. The inherent safety of hybrid rocket motors offers the potential to greatly reduce overall operating costs. Another key advantage of hybrid rocket motors is the potential for in-flight shutdown, restart, and throttle by controlling the pressure drop between the oxidizer tank and the injector. This research designed, developed, and ground tested a closed-loop throttle controller for a hybrid rocket motor using nitrous oxide and hydroxyl-terminated polybutadiene as propellants. The research simultaneously developed closed-loop throttle algorithms and lab scale …

Design And Construction Of A Tunable Light Source With Light Emitting Diodes For Photosynthetic Organisms, Nathan Phillipps

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis describes and documents the design and construction of a light source which is tunable and has the ability to mimic the spectral output of the sun in the photosynthetic active radiation range (400 - 700 nm). To adjust the spectral output at different wavelengths different types of LEDs were chosen and combined. This thesis describes the design, construction, testing, and suggestions for further improvements to this light source. The light source is comprised of 900 LEDs with 26 different peak wavelengths within the photosynthetically active radiation range. The light source is made tunable through the use of a …

Study Of Effect Of Temperature On The Synthesis Of Carbon Nanotubes By Floating Catalyst Method, R. Rajarao, B.R. Bhat

Journal of Metals, Materials and Minerals

Carbon nanotubes (CNTs) were grown by floating catalyst method using acetylene as carbon precursor and ferrocene as catalyst precursor. The CNTs were grown in the temperature range of 700 - 1150C. The prepared CNTs were purified by acid treatment and air oxidation methods. The purified CNTs were characterized by scanning electron microscopy, transmission electron microscopy and Raman spectroscopy. The purity of CNTs was determined by thermal analysis and X-ray diffraction method. The yield, diameter and length of grown CNTs were same at all temperatures. The crystalline perfection of CNTs increases as the temperature increases. Our results indicated that the synthesis …

The Effect Of Granule Morphology And Composition On The Compaction Behavior And Mechanical Properties Of 92% Alumina Spray Dried Granules, K. Somton, K. Dateraksa, D. Atong, R. Mccuiston

Journal of Metals, Materials and Minerals

The compaction behavior and flexural strength of green compacts produced from four different types of 92% alumina spray dried granules were studied. Three of the granule types were produced in-house while the fourth is commercially-available. In addition, the decomposition behavior of the granules was studied by TGA in order to help explain the observed results. The morphology of the granules was observed using microscopy. Examination of the three granules produced in-house showed that they have several undesirable features; agglomeration, hollow granules and non-spherical granules. The morphology of the commercial granules showed them to be unagglomerated and spherical. The in-house granules …

Thermal Degradation Of Pet Fabrics Coated With Interpenetrating Polymer Network-Silica Fume Mixtures, B. Kusuktham, S. Harburud, K. Srikulkit

Journal of Metals, Materials and Minerals

Thermal degradation of polyester fabrics coated with interpenetrating polymer network (IPN) and silica fume (SF) was studied. Silica fume was modified with vinyltriethoxysilane (VTES) in order to improve its hydrophobicity and dispersibility in polymer matrix. Interpenetrating polymer network was prepared by sodium alginate (SA) mixed with 2-hydroxyethyl methacrylate (HEMA). Sodium alginate, HEMA, K2S2O8, N,N/ -methylenebisacrylamide, N,N,N/ ,N/ -tetramethylethylenediamine, and modified SF were mixed in aqueous solution with nonionic surfactant. In this condition, modified SF showed high dispersion ability in SA/HEMA solution. Additional, the application of 0.3 M CaCl2 onto PET surface and dried at temperature of 80o C for 1 …

Fabrication And Characterization Of Heterojunction For Cds Thin Films And Cualo2 Ceramic Pill Substrate, T. Gaewdang, N. Wongcharoen, A. Nopparuchikun, T. Wongcharoen, C. Poo-Rakkiat

Journal of Metals, Materials and Minerals

In this research paper, CdS thin films were deposited by thermal evaporation in vacuum on CuAlO2 ceramic pill substrate. From the data of I-V measurements at low temperature (20-300 K) the junction barrier height, ideality factor and series resistance values can be evaluated by using thermionic emission (TE) theory and Cheung's method. The junction barrier height and ideality factor were found to be strong temperature dependence. Evaluation of forward I-V data reveals a decrease in the zero-bias barrier height, but an increase in the ideality factor with decrease in temperature. In part of C-V measurements at room temperature, the obtained …

Electrochemically Enhanced Plasticity Of Steels, Y.B. Unigovski, E.M. Gutman, Z. Koren, B. Borohov

Journal of Metals, Materials and Minerals

It is known that electrochemical surface treatment can decrease the residual stresses and the hardness of the surface layer as a result of the chemomechanical effect (CME), and also to improve the ability to plastic deformation, e.g., deep drawing for high strength alloys. The present research is aimed at using CME in order to improve such technological processes as rolling, deep drawing and other processes requiring an increase in the ductility of the metal surface layer using the hardness test assisted by electrochemical polarization. The hardness measurements were carried out using a microhardness tester equipped with a special three-electrode electrochemical …

Altered Hemodynamics, Endothelial Function, And Protein Expression Occur With Aortic Coarctation And Persist After Repair, Arjun Menon, Thomas J. Eddinger, Hongfeng Wang, David C. Wendell, Jeffrey M. Toth, John F. Ladisa

Biomedical Engineering Faculty Research and Publications

Coarctation of the aorta (CoA) is associated with substantial morbidity despite treatment. Mechanically induced structural and functional vascular changes are implicated; however, their relationship with smooth muscle (SM) phenotypic expression is not fully understood. Using a clinically representative rabbit model of CoA and correction, we quantified mechanical alterations from a 20-mmHg blood pressure (BP) gradient in the thoracic aorta and related the expression of key SM contractile and focal adhesion proteins with remodeling, relaxation, and stiffness. Systolic and mean BP were elevated for CoA rabbits compared with controls leading to remodeling, stiffening, an altered force response, and endothelial dysfunction both …