Engineering Commons^™

Application Of Shredded-Tire Biofilter And Membrane Bioreactor For Greywater Reclamation, Meng Hu

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

Water scarcity is a pressing global issue. Greywater (GW) reclamation is a viable option to reduce freshwater demand. The objectives of this work were to: a) evaluate the feasibility of the combination of shredded tire biofilter (STB) technology and membrane bioreactor (MBR) technology in GW reclamation; b) study the effects of various parameters on STB performance; and c) understand the fouling mechanisms to lower the energy consumption in MBRs. Bench-scale STBs and MBRs (flat-sheet membranes) were constructed to address the first two objectives, while an independent membrane (hollow-fiber membranes) fouling experiment was designed for the third objective.

It was found …

Six Degree Of Freedom Miniature In Vivo Robot For Laparoendoscopic Single-Site Surgery, Ryan L. Mccormick

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

The shift in surgery from open procedures to minimally invasive surgery (MIS) techniques have provided benefits of decreased recovery time, improved cosmetic results, and reduced costs. As advances in MIS move to minimize the number of external incisions, such as with Laparoendoscopic Single-Site (LESS) surgery, additional complexities are introduced. These complexities, including unintuitive controls, reduced dexterity, and limited workspace, hinder these methods from more widespread implementation in more complicated surgical procedures.

Through the use of a miniature in vivo robotic surgical platform designed for LESS surgery, these complexities can be mitigated, allowing for wider adoption of MIS by placing the …

Influence Of Process Parameters On Health Outcome, Vijaya K. Musunuru

Department of Industrial and Management Systems Engineering: Dissertations, Theses, and Student Research

In the recent years, healthcare organizations have realized that quality in providing service is critical for their survival in this competitive world. This increased attention to service quality has forced many health care providers to reevaluate their systems to stay in business. The main purpose of this study is to test the hypothesis “Process Quality predicts the Product quality (patient satisfaction) in the healthcare domain”. The objective of this study was three- fold. The first objective is to analyze historical data both on patient satisfaction and on provider attributes to yield process parameters for a particular area in a hospital. …

Simulation And Control System Of A Railroad Track Power Harvesting Device, Kyle J. Phillips

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

With the vastness of existing railroad infrastructure, there exist numerous road crossings which are lacking warning light systems and/or crossing gates due to their remoteness from existing electrical infrastructure. Along with lacking warning light systems, these areas also tend to lack distributed sensor networks used for railroad track health monitoring applications. With the power consumption required by these systems being minimal, extending electrical infrastructure into these areas would not be an economical use of resources. This motivated the development of an energy harvesting solution for remote railroad deployment.

This thesis describes a computer simulation created to validate experimental on-track results …

Energy Harvesting Systems Design For Railroad Safety, Abolfazl Pourghodrat

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

Railroad grade crossings are locations of significant interest for prevention of collisions, injuries and fatalities. Another area of concern is derailments resulting from mechanically deficient track structures. Many of these incidents occur in remote areas due to the lack of electrical infrastructure to power automated warning systems and/or track health monitoring sensor networks.

Providing electrical infrastructure to railroad crossings in remote areas is often not economical, and other alternative sources of electricity such as solar and wind energy are not reliable or robust. This motivated development of devices for in situ energy harvesting.

Initially, an improved mechanical energy harvesting device …

Robotic Manipulator With Multiple Instruments For Natural Orifice Translumenal Endoscopic Surgery, Chi Min Seow

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

This thesis presents a novel robotic manipulator with multiple instruments for use in Natural Orifice Translumenal Endoscopic Surgery (NOTES). NOTES is a newly emerging surgical technique that eliminates external incisions on patients’ skin. As a result, better cosmetics, shorter recovery time, and reduced risk of external infection can be achieved.

Research has been ongoing in academia and industry to make this surgical procedure more feasible in human surgeries. Although several robotic platforms have been developed, none of them has the required capability to provide surgeons with the most appropriate tool in a safe and timely matter during surgery. This robotic …

Optimal Investment Under Operational Flexibility, Risk Aversion, And Uncertainty, Michail Chronopoulos, Bert De Reyck, Afzal Siddiqui

Research Collection Lee Kong Chian School Of Business

Traditional real options analysis addresses the problem of investment under uncertainty assuming a risk-neutral decision maker and complete markets. In reality, however, decision makers are often risk averse and markets are incomplete. We confirm that risk aversion lowers the probability of investment and demonstrate how this effect can be mitigated by incorporating operational flexibility in the form of embedded suspension and resumption options. Although such options facilitate investment, we find that the likelihood of investing is still lower compared to the risk-neutral case. Risk aversion also increases the likelihood that the project will be abandoned, although this effect is less …

Evaluating The Capacity Of A Proton Therapy Facility, Ridvan Gedik

Graduate Theses and Dissertations

A relatively new consideration in proton therapy planning is the requirement that the mix of patients treated satisfy desired percentages. Since it is very dicult to satisfy an integer number of patients in light of these requirements, deviations from patient mix preferences and their impacts on operational capabilities are of particular interest to healthcare planners. Therefore, we propose a bicriteria mathematical programming model that determines an outpatient schedule maximizing the number of fractions and minimizing the deviations from the patient mix ratios over the planning horizon. The tradeos between the two objectives are identied through analysis of ecient frontiers. Our …

An Empirical Investigation Of Supply Chain Excellence In Healthcare, Brian Keith Smith

Graduate Theses and Dissertations

This research is motivated by opportunities to improve the cost and quality of healthcare delivery through improved supply chain processes. This research assesses the quality of the healthcare supply chain and identifies factors that are driving supply chain excellence among organizations in the healthcare industry. The first objective of this research is to assess the state of quality measurement in the healthcare supply chain. The achievement of this first objective is presented in Chapter 3 of this dissertation in the form of a manuscript accepted for publication in The Quality Management Journal. The second research objective is to develop …

Characterizing Multi-Walled Carbon Nanotube Synthesis For Field Emission Applications, Benjamin L. Crossley, Nathan Glauvitz, Betty T. Quinton, Ronald A. Coutu Jr., Peter J. Collins

Electrical and Computer Engineering Faculty Research and Publications

No abstract provided.

Reliable Ethernet, Aleksandr Movsesyan

Master's Theses

Networks within data centers, such as connections between servers and disk arrays, need lossless flow control allowing all packets to move quickly through the network to reach their destination. This paper proposes a new algorithm for congestion control to satisfy the needs of such networks and to answer the question: Is it possible to provide circuit-less reliability and flow control in an Ethernet network? TCP uses an end-to-end congestion control algorithm, which is based on end-to-end round trip time (RTT). Therefore its flow control and error detection/correction approach is dependent on end-to-end RTT. Other approaches utilize specialized data link layer …

Benefits Of Near-Term Cloud Location Forecasting For Large Solar Pv, Timothy Robert Rudd

Master's Theses

As the ‘green’ energy movement continues to gain momentum, photovoltaic generation is becoming an increasingly popular source for new power generation. The primary focus of this paper is to demonstrate the benefits of close-to real-time cloud sensing for Photovoltaic generation. In order to benefit from this close-to real-time data, a source of cloud cover information is necessary. This paper looks into the potential of point insolation sensors to determine overhead cloud coverage. A look into design considerations and economic challenges of implementing such a monitoring system is included. The benefits of cloud location sensing are examined using computer simulations to …

Face Detection And Lip Localization, Benafsh Nadir Husain

Master's Theses

Integration of audio and video signals for automatic speech recognition has become an important field of study. The Audio-Visual Speech Recognition (AVSR) system is known to have accuracy higher than audio-only or visual-only system. The research focused on the visual front end and has been centered around lip segmentation. Experiments performed for lip feature extraction were mainly done in constrained environment with controlled background noise. In this thesis we focus our attention to a database collected in the environment of a moving car which hampered the quality of the imagery.

We first introduce the concept of illumination compensation, where we …

Full Custom Vlsi Design Of On-Line Stability Checkers, Chris Y. Lee

Master's Theses

A stability checker is a clocked storage element, much like a flip-flop, which detects unstable and late signals in the pipeline of a digital system. The On-line stability checker operates concurrently with its associated circuit-under-test (CUT). This thesis describes the full custom very-large-scale integration (VLSI) design and testing process of On-Line Stability Checkers. The goals of this thesis are to construct and test Stability Checker designs, and to create a design template for future class projects in the EE 431 Computer-Aided Design (CAD) of VLSI Devices course at Cal Poly.

A method for concurrent fault testing called On-line Stability Checking …

Equivalent Circuit Implementation Of Demyelinated Human Neuron In Spice, Nathan A. Angel

Master's Theses

This work focuses on modeling a demyelinated Hodgkin and Huxley (HH) neuron with Simulated Program with Integrated Circuit Emphasis (SPICE) platform. Demyelinating disorders affect over 350,000 people in the U.S and understanding the demyelination process at the cellular level is necessary to find safe ways to treat the diseases [9]. Utilizing a previous SPICE model of an electrically small cell neuron developed by Szlavik [32], an extended core conductor myelinated neuron was produced in this work. The myelinated neuron developed has seven active Nodes of Ranvier (nodes) separated by a myelin sheath. The myelin sheath can be successfully modeled with …

Global Flow Impacts Time-To-Passage Judgments Based On Local Motion Cues, Scott A. Beardsley, Elif M. Sikoglu, Heiko Hecht, Lucia M. Vaina

Biomedical Engineering Faculty Research and Publications

We assessed the effect of the coherence of optic flow on time-to-passage judgments in order to investigate the strategies that observers use when local expansion information is reduced or lacking. In the standard display, we presented a cloud of dots whose image expanded consistent with constant observer motion. The dots themselves, however, did not expand and were thus devoid of object expansion cues. Only the separations between the dots expanded. Subjects had to judge which of two colored target dots, presented at different simulated depths and lateral displacements would pass them first. Image velocities of the target dots were chosen …

Zeolite‐Based Algae Biofilm Rotating Photobioreactor For Algae And Biomass Production, Ashton M. Young

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Alkaline conditions induced by algae growth in wastewater stabilization ponds create deprotonated ammonium ions that result in ammonia gas (NH₃) volatilization. If algae are utilized to remediate wastewater through uptake of phosphorus, the resulting nitrogen loss will hinder this process because algae generally require a stoichiometric molar ratio of N₁₆P₁. Lower ratios of N/P due to loss of ammonia gas will limit the growth and yield of algae, and therefore will reduce phosphorus removal from the water phase into the algae phase. In order to reduce nitrogen loss through volatilization, an ammonium selective zeolite, …

Cognitive Formation Flight In Multi-Unmanned Aerial Vehicle-Based Personal Remote Sensing Systems, Long Di

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This work introduces a design and implementation of using multiple unmanned aerial vehicles (UAVs) to achieve cooperative formation flight based on the personal remote sensing platforms developed by the author and the colleagues in the Center for Self-Organizing and Intelligent Systems (CSOIS). The main research objective is to simulate the multiple UAV system, design a multi-agent controller to achieve simulated formation flight with formation reconfiguration and real-time controller tuning functions, implement the control system on actual UAV platforms and demonstrate the control strategy and various formation scenarios in practical flight tests. Research combines analysis on flight control stabilities, develop- ment …

Low-Thrust Assisted Angles-Only Navigation, Robert W. Gillis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Tradition spacecraft proximity operations require large and expensive on-board sensors and significant ground support. Relative angle measurements can be obtained from small, simple, and inexpensive on-board sensors, but have not traditionally been used for proximity operation because of difficulty generating rang information. In this thesis it is shown that useful relative range data can be generated provided that the spacecraft is experiencing a small continuous thrust such as would be provided by a low-thrust propulsion system. In previous work range observability was shown with impulsive maneuvers. This thesis will expand this work to low-thrust spacecraft and will show how range …

Discharge Coefficients Of Oblique Weirs, Samuel Egnew Tingey

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Oblique weirs are those weirs placed at an angle with respect to the channel centerline. They can be used in canal applications where more discharge is needed, but there is limited freeboard. The discharge coefficients were determined for 54 different weirs by measuring total head for various flows over each weir. These weirs included sharp, half round and quarter-round-crested weirs. There were 18 weirs for each crest shape with three weir heights for each angle tested. The oblique angles tested were 10°, 15°, 25°, 45°, 60°, and 90° with respect to the channel centerline, with the nominal weir heights being …

Dislocation Density-Based Finite Element Method Modeling Of Ultrasonic Consolidation, Deepankar Pal

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A dislocation density-based constitutive model has been developed and implemented into a crystal plasticity quasi-static finite element framework. This approach captures the statistical evolution of dislocation structures and grain fragmentation at the bonding interface when sufficient boundary conditions pertaining to the Ultrasonic Consolidation (UC) process are prescribed.

The hardening is incorporated using statistically stored and geometrically necessary dislocation densities (SSDs and GNDs), which are dislocation analogs of isotropic and kinematic hardening, respectively. Since the macroscopic global boundary conditions during UC involves cyclic sinosuidal simple shear loading along with constant normal pressure, the cross slip mechanism has been included in the …

A Thermomechanical Analysis Of An Ultrasonic Bonding Mechanism, Chunbo Zhang

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A systematic experimental and numerical combined study of the thermomechanical bonding mechanisms in the ultrasonic welding (UW) process was conducted. A fully coupled thermomechanical finite element model has been built to fully understand the evolution and coupling between the in-process thermomechanical variables. The severe, localized, plastic deformation at the bond region is believed to be the major phenomenon for bond formation in ultrasonic welding. The influences of substrate dimensions on bond formation were studied and explained with an analytical vibration model. The formation of banded and cyclic stress-strain maxima in the substrate was found to be caused by superposition of …

Autonomous Aerial Manipulation Using A Quadrotor, Vaibhav Ghadiok

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This paper presents an implementation of autonomous indoor aerial gripping using a low-cost, custom-built quadrotor. Such research extends the typical functionality of micro air vehicles (MAV) from passive observation and sensing to dynamic interaction with the environment. To achieve this, three major challenges are overcome: precise positioning, sensing and manipulation of the object, and stabilization in the presence of disturbance due to interaction with the object. Navigation in both indoor and outdoor unstructured, Global Positioning System-denied (GPS-denied) environments is achieved using a visual Simultaneous Localization and Mapping (SLAM) algorithm that relies on an onboard monocular camera. A secondary camera, capable …

Estimating Yield Of Irrigated Potatoes Using Aerial And Satellite Remote Sensing, Saravanan Sivarajan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Multispectral aerial and satellite remote sensing plays a major role in crop yield prediction due to its ability to detect crop growth conditions on spatial and temporal scales in a cost effective manner. Many empirical relationships have been established in the past between spectral vegetation indices and leaf area index, fractional ground cover, and crop growth rates for different crops through ground sampling. Remote sensing-based vegetation index (VI) yield models using airborne and satellite data have been developed only for grain crops like barley, corn, wheat, and sorghum. So it becomes important to validate and extend the VI-based model for …

Immersion Cooling Of Photovoltaic Cells In Highly Concentrated Solar Beams, Ahmed Darwish

UNLV Theses, Dissertations, Professional Papers, and Capstones

Concentrated solar radiation can be utilized to generate electrical power from photovoltaic cells, but concentrated solar radiation increases the photovoltaic cell’s temperature. This increase in temperature can lead to degradation of the cell efficiency, and too high of a temperature can damage the cell’s integrity. This is particularly important in dish and tower systems where a maximum uniform flux may be difficult to achieve. While a variety of approaches have been used to the keep the cells cool, most are based upon removal of heat from the back (opposite surface of the incident flux exposed surface) of the cell. This …

Raman Spectroscopic Study Of Solid Solution Spinel Oxides, Brian D. Hosterman

UNLV Theses, Dissertations, Professional Papers, and Capstones

Solid solution spinel oxides of composition MgxNi1−xCr2O4, NiFexCr2−xO4, and FexCr3−xO4 were synthesized and characterized using x-ray diffraction and Raman spectroscopy. Frequencies of the Raman-active modes are tracked as the metal cations within the spinel lattice are exchanged. This gives information about the dependence of the lattice vibrations on the tetrahedral and octahedral cations. The highest-frequency Raman-active mode, A1g, is unaffected by substitution of the divalent tetrahedral cation, whereas the lower frequency vibrations are more strongly affected by substitution of the tetrahedral cation. The change in wavenumber of many phonons is nonlinear upon cation exchange. All detected modes of MgxNi1−xCr2O4 and …

Comparison Of Design-Build And Design-Bid-Build Performance Of Public University Projects, James David Fernane

UNLV Theses, Dissertations, Professional Papers, and Capstones

With an unsure market and scarce work, owners across the United States, especially universities, are finding themselves in situations where they are unable to complete their projects within cost and schedule using the traditional delivery method: Design-Bid-Build (DBB). Under the DBB project delivery method, many competent contractors are electing to send low bids on projects just to keep work on their books, with plans to receive change orders once the project is underway; this practice is leading to cost and schedule overruns. Public universities across the United States are beginning to elect to use Design-Build (DB) as an alternate project …

Groundwater Contamination Potential In Northern Nevada From Mining, Associated Communities, And Agriculture As Forecasted By Two Vulnerability Methods, John L. Swatzell

UNLV Theses, Dissertations, Professional Papers, and Capstones

Two methodologies, DRASTIC and the NDEP method, were used to compare the groundwater vulnerability of mining, associated towns, and agricultural areas in northern Nevada. The DRASTIC and NDEP methods were compared to determine which method produces a more accurate depiction of vulnerability. Vulnerability maps were created using the United States Environmental Protection Agency's (USEPA) DRASTIC and Nevada Department of Environmental Protection (NDEP) methodologies. The DRASTIC map uses seven aspect layers of geologic and hydrologic information with assigned values and weights that are applied to a mathematical equation. The NDEP method uses field data collection for potential contaminant sources and well …

Structural, Electrical And Thermoelectric Properties Of Chromium Silicate Thin Films, Makram Abd El Qader

UNLV Theses, Dissertations, Professional Papers, and Capstones

Thermoelectric devices can generate electrical power as a result of their ability to produce electrical currents in the presence of thermal gradients. They can also produce refrigerative cooling when electrical power is supplied to them. Among the potential semiconducting silicides, CrSi ₂ is attractive because of its high thermal and chemical stability and its potential for thermoelectric application. CrSi₂ /SiO₂ thin-film structures were prepared using RF sputtering. As deposited and annealed (300°C to 600°C) thin films were characterized for their structural, electrical, and thermoelectric transport properties. As-sputtered CrSi ₂ film is amorphous at room temperature and crystallizes around …

Cyber Physical Complex Networks, Modeling, Analysis, And Control, Neveen Shlayan

UNLV Theses, Dissertations, Professional Papers, and Capstones

This research scrutinize various attributes of complex networks; mainly, modeling, sensing, estimation, safety analysis, and control. In this study, formal languages and finite automata are used for modeling incident management processes. Safety properties are checked in order to verify the system. This method introduces a systematic approach to incident management protocols that are governed by mostly unsystematic algorithms. A portion of the used data in this study is collected by means of radar and loop detectors. A weighted t-statistics methodology is developed in order to validate these detectors. The detector data is then used to extract travel time information where …