Engineering Commons^™

Membrane Compatibility With Switchable Polarity Draw Solutions For Use In Forward Osmosis Applications, Benjamin Joseph Coscia

Honors Scholar Theses

Water scarcity is problem being faced worldwide and present in every continent. Close to one-fifth of the world’s population has difficulty acquiring safe water, and the problem is worsening as populations continue to grow in poorer countries. As the availability of unimpaired freshwater sources dwindle, water sources, such as the oceans and saline ground waters, must be tapped. However, desalination technologies are very expensive due to a high energy requirement. Forward osmosis (FO) is a process which may be able to replace or become integrated with existing desalination technologies like reverse osmosis. FO relies on an osmotic agent, or draw …

Time-Driven Activity-Based Costing For Healthcare Provider Supply Chain Processes, Martha Isaura Gonzalez

Graduate Theses and Dissertations

In a time when healthcare costs continue to rise, nearly a third of hospital operating expenses are related to supplies, and the healthcare supply chain is complex, it is pertinent for healthcare providers to have a clear understanding of their healthcare supply chain process costs. Having a clear picture into how these costs are driven and where opportunities for cost reductions exist can support supply chain efficiencies. In this research, we develop a Time-Driven Activity-Based Costing (TDABC) supply chain cost management tool for healthcare providers. A TDABC management system can provide healthcare providers with valuable product and process supply chain …

Poisson Distributed Individuals Control Charts With Optimal Limits, Negin Enayaty Ahangar

Graduate Theses and Dissertations

The conventional method used in attribute control charts is the Shewhart three sigma limits. The implicit assumption of the Normal distribution in this approach is not appropriate for skewed distributions such as Poisson, Geometric and Negative Binomial. Normal approximations perform poorly in the tail area of the these distributions. In this research, a type of attribute control chart is introduced to monitor the processes that provide count data. The economic objective of this chart is to minimize the cost of its errors which is determined by the designer. This objective is a linear function of type I and II errors. …

A Review Of The Pinned Photodiode For Ccd And Cmos Image Sensors, Eric R. Fossum, Donald B. Hondongwa

Dartmouth Scholarship

The pinned photodiode is the primary photodetector structure used in most CCD and CMOS image sensors. This paper reviews the development, physics, and technology of the pinned photodiode.

Damage Stability Of Inland Towboats, Kyle Stephen Tyson

Senior Honors Theses

The focus of this report is to investigate whether a towboat would be able meet damaged stability requirements. In order to evaluate what type of damage stability requirements could be considered, two damage stability criteria were selected for this investigation: Offshore Supply Vessel and Passenger Vessel Damage Criteria. Two vessels are then evaluated using General Hydrostatic Software (GHS) to find the maximum allowable vertical center of gravity allowed by each set of criteria. These values are then compared to the vessels’ operating conditions to show if the vessels would currently be able to operate. Ultimately it is found that the …

Starch-Pectin Matrices For Encapsulation Of Ascorbic Acid, Yiwei Liu

Department of Food Science and Technology: Dissertations, Theses, and Student Research

Starch and pectin are two food-grade carbohydrates widely utilized in the food industry. Starch and pectin polymers have been investigated in encapsulating functional food ingredients and in pharmaceutical applications. Resistance to enzyme hydrolysis, differential solubilities, depending on the pH, and the ability to ‘protect’ unstable molecules are considered some of the beneficial properties of starch and pectin polymers, for encapsulation applications. Food ingredients could be delivered in a controlled manner to a specific target by encapsulating in micro-scale particles, i. e., microencapsulation. Two studies were conducted to investigate the ability of selected starch-pectin blends in microencapsulating ascorbic acid (vitamin C) …

Response Of Large River Fishes To A Prolonged High Water Event In The Missouri River, Nebraska, Nicholas Paul Hogberg

School of Natural Resources: Dissertations, Theses, and Student Research

Regulation and modification of large rivers to accommodate human uses have been a root cause of freshwater biodiversity declines. The Missouri River is among the most drastically-altered large river systems in North America, with a series of mainstem impoundments in the upper watershed altering flow characteristics downstream, and channelization throughout the lower river homogenizing instream habitat and reducing off-channel habitat. Precipitation events during the winter and spring 2010-2011 caused flooding of the greatest magnitude and duration since reservoir completion. The large magnitude and long duration of this flood made it unlike any flood in recent history and provided a unique …

Scalable Nano Particle Production Of Low Bioavailability Pharmaceuticals For Augmented Aqueous Solubility, Aaron Madden

HIM 1990-2015

The billion dollar pharmaceutical research and development pipeline suffers greatly from high attrition rates of novel therapeutic compounds within pre-clinical and clinical trials. Poor bioavailability in many new drugs, originating in the various methodologies of high throughput screening, may explain part of these growing failure rates. One interpretation of this phenomenon relies on bioavailability's correlation with aqueous solubility; much modern processing allows chemicals to fully develop without touching water, yielding upwards of 90% of new chemical entities practically insoluble in aqueous media. Thus, one approach to alleviating bioavailability and potentially clinical attrition rates necessitates augmented aqueous solubility. The amorphous nanoparticle …

Multi-Muscle Fes Force Control Of The Human Arm For Arbitrary Goals, Eric M. Schearer, Yu-Wei Liao, Eric J. Perreault, Matthew C. Tresch, William D. Memberg, Robert F. Kirsch, Kevin M. Lynch

Mechanical Engineering Faculty Publications

We present a method for controlling a neuroprosthesis for a paralyzed human arm using functional electrical stimulation (FES) and characterize the errors of the controller. The subject has surgically implanted electrodes for stimulating muscles in her shoulder and arm. Using input/output data, a model mapping muscle stimulations to isometric endpoint forces measured at the subject’s hand was identified. We inverted the model of this redundant and coupled multiple-input multiple-output system by minimizing muscle activations and used this inverse for feedforward control. The magnitude of the total root mean square error over a grid in the volume of achievable isometric endpoint …

A Swat Model For A Cocoa Growing Region In Ghana, Russell Thomas Bair

Biological and Agricultural Engineering Undergraduate Honors Theses

For agricultural outputs to rise with population, more sustainable and productive methods must be identified. Watershed modeling is a way to relatively quickly compare possible impacts of large scale agricultural practice changes. The goal of this project was to develop a watershed model for the Pra River basin in southern Ghana, a cocoa growing region, that could be used for future impact studies of land management practice options. The model was developed using the Soil Water Assessment Tool (SWAT) and calibrated using the best daily stream flow data that could be readily located. With an R2 value of 0.57 and …

Bellevue-Santa Fe Charter School Solar Panel Project, Dulce Arroyo Martinez, Henrik Lee, Moises Quiroz, Timothy Iafrate

Mechanical Engineering

This project covers the design, manufacture, and installation of solar panel frames on a charter school in Avila Beach, CA. Through preliminary research regarding important factors (such as solar movement, ideal panel angle, and site-specific factors), a frame that meets the standards set forth in the California Building Codes was designed. After approval by presiding authorities, parts specified in the design were ordered, inspected upon arrival, and manufactured to the design as necessary. Much of the challenge was related to the installation aspect of the project—coordination with the proper authorities and correct submission of applications was integral to the success …

Experimental And Numerical Investigations Of Microdroplet Evaporation With A Forced Pinned Contact Line, Kevin Gleason

HIM 1990-2015

Experimental and numerical investigations of water microdroplet evaporation on heated, laser patterned polymer substrates are reported. The study is focused on both (1) validating numerical models with experimental data, (2) identifying how changes in the contact line infuences evaporative heat transfer and (3) determining methods of controlling contact line dynamics during evaporation. Droplets are formed using a bottom-up methodology, where a computer-controlled syringe pump supplies water to a ~200[micro]m in diameter fluid channel within the heated substrate. This methodology facilitates precise control of the droplets growth rate, size, and inlet temperature. In addition to this microchannel supply line, the substrate …

The Thermodynamics Of Planetary Engineering On The Planet Mars, Christopher Barsoum

HIM 1990-2015

Mars is a potentially habitable planet given the appropriate planetary engineering efforts. In order to create a habitable environment, the planet must be terraformed, creating quasi-Earth conditions. Benchmarks for minimum acceptable survivable human conditions were set by observing atmospheric pressures and temperatures here on Earth that humans are known to exist in. By observing a positive feedback reaction, it is shown how the sublimation of the volatile southern polar ice cap on Mars can increase global temperatures and pressures to the benchmarks set for minimum acceptable survivable human conditions. Given the degree of uncertainty, utilization of pressure scale heights and …

The Tlc Method For Modeling Creep Deformation And Rupture, David May

HIM 1990-2015

This thesis describes a novel new method, termed the Tangent-Line-Chord (TLC) method, that can be used to more efficiently model creep deformation dominated by the tertiary regime. Creep deformation is a widespread mechanical mode of failure found in high-stress and temperature mechanical systems. To accurately simulate creep and its effect on structures, researchers utilize finite element analysis (FEA). General purpose FEA packages require extensive amounts of time and computer resources to simulate creep softening in components because of the large deformation rates that continuously evolve. The goal of this research is to employ multi-regime creep models, such as the Kachanov-Rabotnov …

Organizational Accountability In The W.A.S.H. Sector: Integrating Sustainability Factors Into The Definition Of Success, Kaitlyn Jeanis

HIM 1990-2015

The world's poorest people, most of whom reside in under-developed nations, lack access to clean water and sanitation facilities, nutritious food, and education (UMP, 2005). These conditions are linked to malnutrition, disease, and low life expectancies (WHO). In an effort to reduce global poverty, the United Nations (UN) adopted the Millennium Development Goals (MDGs). Under Goal 7c the UN denotes that by 2015 the population without sustainable access to safe drinking water and basic sanitation as compared to the proportion who do should be halved. As a response to this objective the international development (ID) sector has implemented projects aimed …

Coal Fires: An Environmental Disaster, Edward K. Jenner

Chemical Engineering Undergraduate Honors Theses

Coal Fires are an environmental disaster.

Coal Fires: An Environmental Disaster, Carolyn Schardt

Chemical Engineering Undergraduate Honors Theses

Coal Fires are part of an environmental disaster.

Time Correlated Measurements Using Plastic Scintillators With Neutron-Photon Pulse Shape Discrimination, Norman Edison Richardson

UNLV Theses, Dissertations, Professional Papers, and Capstones

Since the beginning of the nuclear age, there has been a strong demand for the development of efficient technologies for the detection of ionizing radiation. According to the United States' Department of Energy, the accurate assessment of fissile materials is essential in achieving the nonproliferation goals of enhancing safety and security of nuclear fuel cycle and nuclear energy facilities [1]. Nuclear materials can be characterized by the measurement of prompt and delayed neutrons and gamma rays emitted in spontaneous or induced fission reactions [2] and neutrons emitted in fission reactions are the distinctive signatures of nuclear materials. Today, the most …

Study Of Water Transport Phenomena On Cathode Of Pemfcs Using Monte Carlo Simulation, Karn Soontrapa

UNLV Theses, Dissertations, Professional Papers, and Capstones

This dissertation deals with the development of a three-dimensional computational model of water transport phenomena in the cathode catalyst layer (CCL) of PEMFCs. The catalyst layer in the numerical simulation was developed using the optimized sphere packing algorithm. The optimization technique named the adaptive random search technique (ARSET) was employed in this packing algorithm. The ARSET algorithm will generate the initial location of spheres and allow them to move in the random direction with the variable moving distance, randomly selected from the sampling range, based on the Lennard-jones potential of the current and new configuration. The solid fraction values obtained …

Co-Emulation Of Scan-Chain Based Designs Utilizing Sce-Mi Infrastructure, Bill Jason Pidlaoan Tomas

UNLV Theses, Dissertations, Professional Papers, and Capstones

Simulation times of complex System-on-Chips (SoC) have grown exponentially as designs reach the multi-million ASIC gate range. Verification teams have adopted emulation as a prominent methodology, incorporating high-level testbenches and FPGA/ASIC hardware for system-level testing (SLT). In addition to SLT, emulation enables software teams to incorporate software applications with cycle-accurate hardware early on in the design cycle. The Standard for Co-Emulation Modeling Interface (SCE-MI) developed by the Accelera Initiative, is a widely used communication protocol for emulation which has been accepted by major electronic design automation (EDA) companies.

Scan-chain is a design-for-test (DFT) methodology used for testing digital circuits. To …

Simulations Of Interfacial Electrokinetics With Applications To Microfluidic Systems, Sebastian Uppapalli

UNLV Theses, Dissertations, Professional Papers, and Capstones

Electrokinetics plays an important role in facilitating fluid transport and particle manipulation in microfluidic systems. This dissertation studies the mechanics of electrokinetic phenomena for microscale particles and drops. The work aims to increase the understanding of complex electrokinetic phenomena for applications in Lab-on-Chip technology, assembly of colloidal particles and two-phase flow sensing. The standard model consisting of the Poisson-Nernst-Planck equations is used to study the electric double layer polarization of charged dielectric particles and channel wall which plays a major role in control and manipulation of colloidal particles and understanding of electrohydrodynamic flow field.

The cases of polarization of "soft" …

Post-Occupancy Energy Efficiency Evaluation Of A Leed Platinum Federal Government Facility, Theresa Tincher

UNLV Theses, Dissertations, Professional Papers, and Capstones

The purpose of this study was to gain a comprehensive understanding of the Leadership in Energy and Environmental Design (LEED®) certification system and its relevance to Federal policies, building codes, and building standards, develop experience with whole building energy modeling, and determine the actual post-occupancy energy usage as compared with developed model and design projections. This thesis hypothesized the U.S. Green Building Council's LEED rating system compared favorably to other policies, codes, and standards in use at the time, and the U.S. Bureau of Reclamations' LEED Platinum Lower Colorado Regional Office Green Building (LCROGB), located in Boulder City, Nevada, operated …

Influence Of Limestone Powder Content And Size On Transport Properties Of Self-Consolidating Concrete, Rebecca Kendal Spitek

UNLV Theses, Dissertations, Professional Papers, and Capstones

Self-consolidating concrete (SCC) requires higher cementitious materials content than conventional vibratory-placed concrete. This requirement leads to higher time-dependent properties (i.e., shrinkage (drying and autogeneous) and creep), increases formwork pressure, and results in a higher production cost. One alternative to alleviate excess creep and shrinkage, and to reduce cost, is to replace a portion of cementitious materials with mineral additives. The objective of this study was to examine the role of limestone powder, as a partial replacement of cementitious materials, on transport properties of self-consolidating concrete (SCC). A total of 10 different SCCs, including a control concrete, was prepared and test …

Analysis Of Bolted Joints Under Medium And High Impact Loading, Deepak Somasundaram

UNLV Theses, Dissertations, Professional Papers, and Capstones

Understanding the transient behavior of structures with bolted joints when subjected to medium and high shock or impact loads can be challenging due to their nonlinear response, which is induced by the complex interactions between the bolts and the structure. While few researchers have considered shock transmission through bolted joints at low impact loading, there are little literature on shock transmission through bolted joints under high loading conditions. Low impact loading condition generally excites the lower order frequencies but under high impact loading higher order frequencies are excited. Typical factors that affect the response of a bolted joint include, preload …

Real-Time Scheduling Algorithm Design On Stochastic Processors, Anushka Pakrashi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Recent studies have shown that significant power savings are possible with the use of in-exact processors, which may contain a small percentage of errors in computation. However, use of such processors in time-sensitive systems is challenging as these processors significantly hamper the system performance. In this thesis, a design framework is developed for real-time applications running on stochastic processors. To identify hardware error pat- terns, two methods are proposed to predict the occurrence of hardware errors. In addition, an algorithm is designed that uses knowledge of the hardware error patterns to judiciously schedule real-time jobs in order to maximize real-time …

Mechanical And Physical Properties Of Spider Silk Films Made From Organic And Water-Based Dopes, Chauncey Lewis Tucker

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Spider silk has become a popular material due to its exceptional mechanical and biocompatibility properties. The project team has developed methods of producing and improving the properties of synthetic spider silk films. Other groups have been able to produce similar films having less than impressive mechanical properties using a toxic solvent. The spider silk team here at Utah State University has developed a new way of processing these films to more than triple their mechanical properties and has created a novel form of spider silk films produced from a water-based liquid, making it less expensive, more environmentally friendly, and more …

Salinity Management In The Upper Colorado River Basin: Modeling, Monitoring, And Cost-Equity Challenges, Jongho Keum

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Salinity issues in the Upper Colorado River Basin have been a serious concern to the western United States and northern Mexico. The Colorado River salinity is mainly come from geologic materials located in the Upper Colorado River Basin. Natural weathering and human activities, such as irrigation, accelerate the dissolution of saline materials. Economic damages due to salinity in the Colorado River Basin are estimated at $295 million in 2010, for example, reduced crop yield, plugging of water pipes and fixtures, and ecological health of rivers. In order to manage salinity in the Upper Colorado River Basin, SPARROW model has been …

Lifecycle Assessment Of Microalgae To Biofuel: Thermochemical Processing Through Hydrothermal Liquefaction Or Pyrolysis, Edward P. Bennion

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Microalgae have many desirable attributes as a renewable energy recourse. These include use of poor quality land, high yields, and it is not a food recourse. This research focusses on the energetic and environmental impact of processing microalgae into a renewable diesel. Two thermochemical bio-oil recovery processes are analyzed, pyrolysis and hydrothermal liquefaction (HTL). System boundaries include microalgae growth, dewatering, thermochemical bio-oil recovery, bio-oil stabilization, conversion to renewable diesel, and transportation to the pump. Two system models were developed, a small-scale experimental and an industrial-scale. The small-scale system model is based on experimental data and literature. The industrial-scale system model …

Precision Current Control For Quantum Cascade Lasers As Flight Calibration Sources, Stewart M. Hansen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The design of a precision current controller for quantum cascade lasers (QCLs) enables QCLs to be used for calibrating instruments in space-borne applications. This current controller design will enable constant wave (CW) or pulsed mode operation of QCL devices as calibration sources in a space environment. Any differences in the temperature between components of the current controller can result in an erroneous current through the QCL. This design will use previously demonstrated techniques from Pacific Northwest National Laboratory (PNNL) to minimize the effects of temperature changes on the desired current levels. A mathematical model is used to calculate what performance …

Automatic Registration Of Multiple Texel Images To Form A 3-Dimensional Texel Image, Neeraj S. Badamikar

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Three-dimensional (3D) imaging has found a lot of use in modern era, owing to the fast ongoing advancement in electronics, processors, and sensors, all available at affordable prices. Three-dimensional television, games, and 3D projectors are some of the commonly found utilities which use 3D imaging. 3D images used for surveillance, exploration, target acquisition equipment, etc., are few of the military applications of 3D imaging. As the need increases, more techniques are being introduced to create 3D images which improve upon previously stated techniques. This thesis proposes an algorithm which uses “texel” images, which are images that have digital imagery fused …