Engineering Commons^™

Design Of A Split Hopkinson Bar Apparatus For Use With Fiber Reinforced Composite Materials, Shawn Michael Lang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tabulated material properties are the starting block for the design of most structures. Mechanical structures undergo a wide range of loading conditions. Structures can be loaded statically or dynamically with a wide range of strain rates. With impact loading or high strain rates the relationships between stress and strain are not the same as in static loading. It has been observed that material properties are dependent upon the rate at which they are tested. Many investigators have studied the effect of high compressive strain rate loading conditions, in metals. The most common method for determining the dynamic response of materials …

Root Uptake Of Organic Contaminants Into Plants: Species Differences, Naho Orita

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Xenobiotic organic contaminants are widely found in the environment, including soils, sediments, surface waters, wastewater streams, and even in drinking water. Food chain contamination resulting from the uptake of these contaminants by plants is a concern. Although the uptake of a variety of xenobiotic organic contaminants by plants has been reported but the differences between plant species are not fully understood. The emphasis of this thesis research is to further investigate the unique root to shoot transfer ability of “gold rush” zucchini that has been reported repeatedly in recent years.

A pressure chamber technique was used to measure transpiration stream …

Numerical And Experimental Study Of Anisotropic Effective Thermal Conductivity Of Particle Beds Under Uniaxial Compression, Jingwen Mo

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Planetary heat flow is of great interests to planetary scientists, which can be used to determine the history and current status of pianetary bodies. Thermal conductivities of planetary bodies are generally measured using long needle-like probes inserted into planet's surface, which measure the horizontal effective thermal conductivity (parallel to the planetary surface). The vertical effective thermal conductivity (perpendicular to the planetary surface), used for heat flow calculation, is assumed to be the same as the horizontal effective thermal conductivity. However, ETC of particle beds is known to be an anisotropic property under low compressive pressures.

The objective of this study …

Experimental Studies Of Vertical Mixing In An Open Channel Raceway For Algae Biofuel Production, Ram Sudheer Voleti

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The USU BioEnergy Center has been successful in developing algae feedstocks for renewable biofuels and bioproducts. The concept is to utilize and maximize algae feedstocks for liquid transportation fuels, biomass for burning and digestion, and high value co-products. It is theorized that increasing the mixing in open and closed algal production systems improves the productivity of the algae culture. A raceway cultivation system was chosen to examine the phenomena of mixing. Vertical mixing will provide more uniform exposure to sunlight for all of the algae in the raceway. The main focus of this research was to increase vertical mixing. Delta …

Unified Rating Equations For Cutthroat Flumes Derived From A Three-Dimensional Hydraulic Model, Sathaporn Temeepattanapongsa

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A sophisticated mathematical model of three-dimensional hydraulics was used to develop complete calibrations for Cutthroat flumes, which are structures used in canals (or “open channels”) to measure flow rates. Although Cutthroat flumes have been used for many years, and much research has been done on their calibrations and application in the field, never before was there a complete set of calibration parameters for all 24 standard flume sizes. This research was validated by previously published laboratory results on prototype flumes at Utah State University and elsewhere, and it was successful in generating accurate calibration parameters for all 24 flume sizes, …

Value Of Information In Design Of Groundwater Quality Monitoring Network Under Uncertainty, Abdelhaleem I. Khader

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Due to variations in rainfall and limited surface water resources, groundwater is considered the main source for freshwater in many places throughout the word. But this precious resource is being jeopardized by pollution from human activities such as: industry, agriculture, and untreated wastewater, which highlight the need for efficient groundwater resources management. To be efficient, groundwater resources management requires efficient access to reliable information that can be acquired through monitoring. On the other hand, the complicated nature of groundwater aquifers and the uncertainties in the data and the models used to understand the aquifer and its behavior require more powerful …

A Study On Conformal Antenna Solutions For Cube Satellites, Maryam Jamali

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This master's thesis presents a study on two types of conformal antennas for the use on cube satellites (CubeSats). The two antenna solutions are including slot and microstrip patch antennas. CubeSats have been one of the most important vehicles for space exploration due to their small sizes and very low payload. At the same time, a challenge rises when allocating extremely limited surface real estate to space instrument, solar cells, and antennas. The most effective solution for such a challenge is to design antennas such that they do not block solar cells or compete for space with solar cells. Accordingly, …

Effects Of Single Panel Replacement Of A Full-Scale, Full-Depth, Precast Concrete Bridge Deck System, Jason Robert Perry

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The use of precast concrete deck panels is becoming increasingly popular for bridge construction and rehabilitation in the state of Utah and across the country. It allows for the use of full depth concrete deck panels but removes the long construction times of traditional cast-in-place methods. One of the challenges to the use of precast deck panels is the transverse deck panel joints that exist between the panels. These joints are unreinforced using traditional methods and therefore are the weakest section of the bridge. In many situations the joint will fail and water seeps through and can damage the bridge …

Effects Of Moisture Augmentation Of Municipal Solid Waste Through Addition Of Food Waste Or Wastewater Treatment Biosolids On Bio-Gas Formation For Power Generation, Jared Michael Gore

UNLV Theses, Dissertations, Professional Papers, and Capstones

An investigation into the effect of moisture augmentation by manipulation of food waste proportion or wastewater treatment plant biosolids proportion was undertaken to determine the effects on production of methane and other biogases from municipal solid waste (MSW). Laboratory microcosm experiments were performed to determine the effect of various proportions of influent waste streams on the production of biogas. Results indicated that moisture augmentation through the addition of food waste to MSW increases the overall bio-gas and hydrogen gas formed during fermentation. Moisture augmentation through addition of wastewater treatment bio-solids lead to inconclusive results. Addition of food waste to MSW …

Statistical Analysis Of A Vehicle Miles Travled Fee For Nevada, Andrew Nordland

UNLV Theses, Dissertations, Professional Papers, and Capstones

Increases in the number of electric, hybrid-electric, and other alternative fuel vehicles, combined with increasing vehicle fuel efficiency present problems with the ability of the fuel tax to collect sufficient revenue. A Vehicle Miles Traveled (VMT) Fee is being considered as an option to replace the existing fuel tax for the collection of revenue for road maintenance, reconstruction and expansion. This study provides an analysis about costs, preference of a potential billing cycle, level of comfort with a mileage collection device, potential changes in transit use, and the effectiveness of a VMT Fee for Nevada. Multinomial logit models are developed …

Cpu Scheduling For Power/Energy Management On Heterogeneous Multicore Processors, Rajesh Patel

UNLV Theses, Dissertations, Professional Papers, and Capstones

Power and energy have become increasingly important concerns in the design and implementation of today's multicore/manycore chips. Many methods have been proposed to reduce a microprocessor's power usage and associated heat dissipation, including scaling a core's operating frequency. However, these techniques do not consider the dynamic performance characteristics of an executing process at runtime, the execution characteristics of the entire task to which this process belongs, the process's priority, the process's cache miss/cache reference ratio, the number of context switches and CPU migrations generated by the process, nor the system load. Also, many of the techniques that employ dynamic frequency …

Analysis Of The Effect Of Feeding Regimen On Gh/Igf Axis In Channel Catfish (Ictalurus Punctatus), Samantha Puckett

Biological and Agricultural Engineering Undergraduate Honors Theses

Channel catfish (Ictalurus punctatus) are the most widely farmed aquatic animal in the United States. Assessing the effect of feeding regimens on their overall growth requires grow-out trials and a subsequent inefficient use of time and money. The growth hormone (GH)/insulin-like growth factor-1 (IGF-1) axis regulates growth based upon environmental factors such as feed intake in many teleost fish species. In order to increase the efficiency of aquaculture, the components of the GH/IGF-1 axis might be used as endocrine biomarkers to evaluate instantaneous growth rate. The goal of this study was to better understand the effects of feeding regimen on …

Investigations Of Conduction Mechanisms Of Ion-Conducting, Bridging Memory Devices (Cbram/Pmc/Ecm), Kyle Bradley Campbell

Boise State University Theses and Dissertations

Electron storage memory devices are approaching the minimum dimensions that are physically possible due to the onward march of Moore’s law. To continue to enable the increased memory densities needed for today’s applications, especially low power and size constrained mobile devices, new memory solutions are needed. Several candidates are emerging in this space. Metal ion-conducting memory devices are being investigated due to excellent scalability, speed, and low power. These devices are part of a memory class called resistive memory. In the literature, they are referred to as CBRAM (conductive bridge random access memory), PMC (programmable metallization cell), ECM (electrochemical metallization …

Proximity Study Of A Uwb Directional Conformal Antenna On Water Pipe, Domenico Gaetano, Max Ammann, Patrick Mcevoy, Matthias John, Louise Keating, Frances Horgan

Articles

A preliminary study on the conformal properties of an antipodal exponentially tapered antenna placed on the surface of a flow meter system in the UWB range is presented. It was observed that the water effect can be mitigated by shifting the antenna away from the pipe surface.

Cost-Effective Safety Treatments For Low-Volume Roads, Kevin D Schrum, Karla A. Lechtenberg, Cody S. Stolle, Ronald K. Faller, Dean L. Sicking

Nebraska Department of Transportation: Research Reports

No abstract provided.

Probing And Controlling Fluid Rheology At Microscale With Magnetic Nanorods, Alexander Tokarev

All Dissertations

This Dissertation is focused on the development of new methods for characterization and control of fluid rheology using magnetic nanorods. This Dissertation consists of five chapters. In the first chapter, we review current microrheologial methods and develop a Magnetic Rotational Spectroscopy (MRS) model describing nanorod response to a rotating magnetic field. Using numerical modeling, we analyze the effects of materials parameters of nanorods and fluids on the MRS characteristic features. The model is designed for a specific experimental protocol. We introduce and examine physical parameters which can be measured experimentally. The model allows identification of MRS features enabling the calculation …

Improved Microalgal Biomass Harvesting Using Optimized Environmental Conditions And Bacterial Bioflocculants, Derek C. Manheim

Master's Theses

ABSTRACT

IMPROVED MICROALGAL BIOMASS HARVESTING USING OPTIMIZED ENVIRONMENTAL CONDITIONS AND BACTERIAL BIOFLOCCULANTS

DEREK CONTE MANHEIM

The cost and energy balance of microalgae biofuel production is sensitive to the algae harvesting method, among many other factors. Bioflocculation and settling of suspended microalgae cultures is a harvesting method with potentially low cost and energy input. However, bioflocculation (the spontaneous flocculation of algal cells without chemical addition) has not been a reliable process with cultures grown in ponds. To provide insights to help improve algae settling, factors affecting the settling of algae were investigated in the laboratory using pure cultures of two common …

The Influence Of Coating Structure On Sheet-Fed Offset Ink Setting Rates, Ting Chen

Masters Theses

Much attention has been paid to the study of quickset ink setting as a complex ink-coating interaction. Offset ink setting rates are typically measured as ink splitting forces versus time and the slope of the regression line obtained from a plot of these measured values is reported, but scant attention has been paid to the deviations from that straight line. An initial slow ink setting rate is desired to minimize back-trap mottle, carryover picking and piling and enhance ink gloss; then a faster ink setting rate during sheet delivery to the pile is desired to reduce the likelihood of ink …

A Novel Method For Determining Acetabular Orientation, Sean Higgins

Theses and Dissertations

Enhanced knowledge of the acetabulum is of paramount importance in the diagnostic, planning, and execution stages of procedures and treatments targeting the hip joint. The convoluted and highly variable morphology of the structures comprising the bony pelvis make ascertaining measures of the acetabulum challenging. Furthermore, current methods for determining acetabular orientation assume symmetry between the separate halves of the pelvis by utilizing a coordinate system based on bilateral landmarks. The purpose of this study was to determine the three-dimensional orientation of the entire acetabulum. For this research, an improved programmatic method was developed for determining acetabular orientation using three-dimensional data. …

Effects Of Acoustic Environments On Speech Comprehension By Native-English-Speaking Listeners, Zhao Peng, Lily M. Wang, Siu Kit Lau

Durham School of Architectural Engineering and Construction: Faculty Publications

This study investigates the effects of acoustic conditions on speech comprehension, rather than speech intelligibility as often reported in existing literature. Sets of 15-minute-long listening comprehension tests were developed based on the format of the Test of English for International Communication (TOEIC). Each test set includes four types of tasks: matching aural phrases to photographs, selecting appropriate responses to aural questions, and answering questions after listening to conversations (between two talkers) and talks (single talker). Within the Nebraska acoustics test chamber, native-English-speaking participants are asked to perform these tests under 15 acoustic conditions, from combinations of three background noise levels …

A Silicon Carbide Linear Voltage Regulator For High Temperature Applications, Javier Antonio Valle Mayorga

Graduate Theses and Dissertations

Current market demands have pushed the capabilities of silicon to the edge. High temperature and high power applications require a semiconductor device to operate reliably in very harsh environments. This situation has awakened interests in other types of semiconductors, usually with a higher bandgap than silicon's, as the next venue for the fabrication of integrated circuits (IC) and power devices. Silicon Carbide (SiC) has so far proven to be one of the best options in the power devices field.

This dissertation presents the first attempt to fabricate a SiC linear voltage regulator. This circuit would provide a power management option …

Comparison Of Various Pipelined And Non-Pipelined Scl 8051 Alus, Jingyi Zhao

Graduate Theses and Dissertations

This paper describes the development of an 8-bit SCL 8051 ALU with two versions: SCL 8051 ALU with nsleep and sleep signals and SCL 8051 ALU without nsleep. Both versions have combinational logic (C/L), registers, and completion components, which all utilize slept gates. Both three-stage pipelined and non-pipelined designs were examined for both versions. The four designs were compared in terms of area, speed, leakage power, average power and energy per operation. The SCL 8051 ALU without nsleep is smaller and faster, but it has greater leakage power. It also has lower average power, and less energy consumption than …

Spectral Analysis Of Encrypted Chaotic Signals Using Fast Fourier Transforms And Laboratory Spectral Analyzers, Monish Ranjan Chatterjee, Abhinay Kundur

Electrical and Computer Engineering Faculty Publications

The use of acousto-optic chaos, as manifested via first-order feedback in an acousto-optic Bragg cell, in encrypting a message wave and subsequently recovering the message in the receiver using a chaotic heterodyne strategy, has been reported recently [1-3]. In examining the dynamical system analytically using computer simulation, (expected) modulated chaos waveforms are obtained within specified observation windows.

Because of the relatively random nature inherent in chaos waveforms, it is essentially impossible to ascertain from the visual display of the chaotic wave whether a given message signal has in fact modulated the chaotic "carrier". In fact, it has been observed from …

Changes In In Vivo Knee Contact Forces Through Gait Modification, Allison Kinney, Thor F. Besier, Amy Slider, Scott L. Delp, Darryl D. D'Lima, Benjamin J. Fregly

Mechanical and Aerospace Engineering Faculty Publications

Gait modification represents a non-invasive method for reducing knee joint loading in patients with knee osteoarthritis. Previous studies have shown that a variety of gait modifications are effective in reducing the external knee adduction moment. The external knee adduction moment is often used as a surrogate measure of medial compartment force. However, a recent study showed that reductions in the external knee adduction moment do not guarantee reductions in medial compartment loads. Therefore, direct measurement of changes in knee contact force is important for determining the effectiveness of gait modifications. A previous study found that medial thrust gait and walking …

Modeling The Adoption Of Identification Standards Within The Healthcare Supply Chain, Angelica Burbano

Graduate Theses and Dissertations

The adoption of identification standards and its associated technology in the healthcare supply chain has been slow over the past twenty five years, despite the evidence of the benefits that can be achieved. The widespread use of identification standards in the form of barcode labeled medical products can contribute to the reduction of point of care errors and can increase the efficiency of healthcare supply chain related processes. This research is focused on the analysis of the adoption of identification standards in the healthcare supply chain with a particular focus on the healthcare provider adoption challenges. The research is divided …

Two-Dimensional Blood Flow Velocity Estimation Using Ultrasound Speckle Pattern Dependence On Scan Direction And Velocity, Tiantian Xu

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Cardiovascular disease is the leading cause death in the United States. Although emergency surgery and medicine can be used for cardiovascular disease treatment, the survivors will suffer for it afterwards. Ultrasound blood flow measurement provides a noninvasive way for cardiovascular diseases diagnosis. In this dissertation, three algorithms for blood flow velocity measurements were investigated and optimized. Feature tracking has been previously proposed for vector velocity measurement. In Chapter 3, the optimal amplitude and time thresholds for feature extraction were investigated to minimize flow estimate variance while providing sufficient spatial and temporal coverage of flow area. A new method of lateral …

Adsorption Kinetics Of Pb(Ii) And Zn(Ii) Ions Unto Carbonized Groundnut Shells And Maize Cobs, Leke Luter, Aboi Julius, Henry T. Dekaa, B. A. Ikyenge, Ande Sesugh, Monday Uchenna Okoronkwo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Maize cobs and groundnut shell adsorbents from agricultural by-products were carbonized and investigated for adsorption of two selected metals, Lead (Pb II) and Zinc (Zn II) from aqueous solutions of these metals. Kinetic studies of the adsorption processes were investigated employing Elovich and the intraparticle diffussion models. The results showed that, the adsorption capacities of these comparatively cheaper adsorbents and their efficiency for the removal of Pb(II) and Zn(II) ions from aqueous solution present them suitable for use in place of the costly commercial activated carbons.

Conductivity Of Twin-Domain-Wall/Surface Junctions In Ferroelastics: Interplay Of Deformation Potential, Octahedral Rotations, Improper Ferroelectricity, And Flexoelectric Coupling, Eugene A. Eliseev, Anna N. Morozovska, Yijia Gu, Albina Borisevich, Long-Qing Chen, For Full List Of Authors, See Publisher's Website.

Materials Science and Engineering Faculty Research & Creative Works

Electronic and structural phenomena at the twin-domain-wall/surface junctions in the ferroelastic materials are analyzed. Carriers accumulation caused by the strain-induced band structure changes originated via the deformation potential mechanism, structural order parameter gradient, rotostriction, and flexoelectric coupling is explored. Approximate analytical results show that inhomogeneous elastic strains, which exist in the vicinity of the twin-domain-wall/surface junctions due to the rotostriction coupling, decrease the local band gap via the deformation potential and flexoelectric coupling mechanisms. This is the direct mechanism of the twin-wall static conductivity in ferroelastics and, by extension, in multiferroics and ferroelectrics. On the other hand, flexoelectric and rotostriction …

Positive Train Control (Ptc): Overview And Policy Issues, Jeffrey Peters

PPRI Digital Library

No abstract provided.

Does An Eye Tracker Tell The Truth About Visualizations?: Findings While Investigating Visualizations For Decision Making, Sung-Hee Kim, Zhihua Dong, Hanjun Xian, Benjavan Upatising, Ji Soo Yi

Hive Lab Publications Archive

For information visualization researchers, eye tracking has been a useful tool to investigate research participants’ underlying cognitive processes by tracking their eye movements while they interact with visual techniques. We used an eye tracker to better understand why participants with a variant of a tabular visualization called ‘SimulSort’ outperformed ones with a conventional table and typical one-column sorting feature (i.e., Typical Sorting). The collected eye-tracking data certainly shed light on the detailed cognitive processes of the participants; SimulSort helped with decision-making tasks by promoting efficient browsing behavior and compensatory decision-making strategies. However, more interestingly, we also found unexpected eye-tracking patterns …