Engineering Commons^™

Comparison Of Data Collection And Methods For The Approximation Of Streambed Thermal Properties, Jonathan D. Bingham

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

When approximating heat transfer through a streambed, an understanding of the thermal properties of the sediments is essential (e.g., thermal conductivity, specific heat capacity, and density). Even though considerable research has been completed in this field, little has been done to establish appropriate standard data collection approaches or to compare modeling methods for approximating these properties. Three mixture models were selected for comparison against each other and against a bed conduction model (SEDMOD). Typical data collection approaches were implemented for use in the mixture models while numerous data collection approaches were employed for use within SEDMOD. Sediment samples were taken …

Dynamically Reconfigurable Systolic Array Accelerators: A Case Study With Extended Kalman Filter And Discrete Wavelet Transform Algorithms, Robert C. Barnes

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Field programmable grid arrays (FPGA) are increasingly being adopted as the primary on-board computing system for autonomous deep space vehicles. There is a need to support several complex applications for navigation and image processing in a rapidly responsive on-board FPGA-based computer. This requires exploring and combining several design concepts such as systolic arrays, hardware-software partitioning, and partial dynamic reconfiguration. A microprocessor/co-processor design that can accelerate two single precision oating-point algorithms, extended Kalman lter and a discrete wavelet transform, is presented. This research makes three key contributions. (i) A polymorphic systolic array framework comprising of recofigurable partial region-based sockets to accelerate …

Terrain-Relative And Beacon-Relative Navigation For Lunar Powered Descent And Landing, Daniel Porter Christensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As NASA prepares to return humans to the moon and establish a long-term presence on the surface, technologies must be developed to access previously unvisited terrain regardless of the condition. Among these technologies is a guidance, navigation and control (GNC) system capable of safely and precisely delivering a spacecraft, whether manned or robotic, to a predetermined landing area. This thesis presents detailed research of both terrain-relative navigation using a terrain-scanning instrument and beacon-relative radiometric navigation using beacons in lunar orbit or on the surface of the moon. The models for these sensors are developed along with a baseline sensor suite …

Hydraulics Of Ideal Drip Irrigation Systems, Evan J. Thompson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The hydraulics of IDEal drip irrigation system components were analyzed under controlled laboratory conditions and the results can be applied to the design of IDEal systems. The hydraulic loss coefficient for the lateral-submain connector valves was determined based on laboratory measurements. It was found that the hydraulic loss due to friction in the lay-flat laterals can be accurately estimated with standard friction loss equations using a smaller effective diameter based on the wall thickness and inlet pressure head. The equivalent length barb loss, expressed as an equivalent length of lateral, was calculated for button emitters, as well as for micro-tubes …

Controlling Nonspecific Adsorption Of Proteins At Bio-Interfaces For Biosensor And Biomedical Applications, Harshil D. Dhruv

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Partitioning of poly(ethyleneglycol) (PEG) molecules in 2-D and 3-D systems is presented as a self-assembly approach for controlling non-specific adsorption of proteins at interfaces.

Lateral restructuring of multi-component Langmuir monolayers to accommodate adsorbing proteins was investigated as a model 2-D system. Ferritin adsorption to monolayers containing cationic, nonionic, and PEG bearing phospholipids induced protein sized binding pockets surrounded by PEG rich regions. The number, size, and distribution of protein imprint sites were controlled by the molar ratios, miscibility, and lateral mobility of the lipids.

The influence of PEG chain length on the ternary monolayer restructuring and protein distribution was also …

Brayton Rotating Unit Design And Analysis For Space Reactor Power Systems, Bruno Martin Gallo

Nuclear Engineering ETDs

This work developed designs and analyses models of centrifugal flow compressor and radial-inflow turbine of integrated Brayton Rotating Units (BRUs) for space reactor power systems. These models calculate the polytropic efficiency of the compressor and turbine, and the electric power and thermal efficiency of the BRUs and the power system for shaft rotational speed of 30 - 55 krpm, reactor power of 120 - 471 kW_th, turbine inlet temperatures of 900 - 1149 K, and He-Xe working fluids of 15 and 40 g/mole. The turbine and compressor models are coupled to the developed model of the rotating shaft …

College Of Engineering Senior Design Competition Spring 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Site-Specific Deoxyribonucleic Acid Modifications For Use With Chemical Cages, John P. Casey Jr

Honors Capstones

No abstract provided.

Mechanical Optimization Of Vertical Axis Wind Turbine Blades, Alexander Laurence Combe

Honors Capstones

No abstract provided.

Intelligent-Navigating, Maze-Mapping, And Maze-Solving Robot Equipped With Sensors, Compass, And Gps System, Yunan Yuan

Honors Capstones

No abstract provided.

Design Of A Multi-Echelon Global Supply Chain Network With Microsoftå¨ Excel Premium Solver Plataform, Wilder Ferreira

All Theses

I designed a global supply chain distribution model of one single product, with the objective of minimizing the costs of transportation, handling materials, duties and tariffs, production, and fixed infrastructure. The distribution network has a combination of manufacturing facilities (fixed and to-be-determined), warehouses (to-be-determined), distribution centers (to-be-determined), and customer zones at fixed locations. This network design is similar to the mathematical mixed-integer linear model from Tsiakis, Shah and Pantelides (2001). This model has been implemented in Microsoft Excel, using the Standard Simplex method from Frontline, Inc. This model optimizes the number of facilities worldwide (multi-echelon) along with the flow of …

Taxonomy Of Physical Prototypes: Structure And Validation, Ashwin Michaelraj

All Theses

This thesis introduces a taxonomy of physical prototypes, and validates the proposed taxonomy by five different approaches. The proposed taxonomy is validated by, (i) checking the orthogonality of individual elements of the taxonomy, (ii) benchmarking the taxonomy with existing classifications of prototypes, (iii) demonstrating its utility by applying it to classify different prototypes, (iv) building a prototype database containing 35 different prototypes, and (v) consistency evaluation of the prototype database using a description logic based software called ProtŽgŽ.
The results indicate that the proposed taxonomy is capable of distinguishing prototypes with greater accuracy when compared to existing classifications. The orthogonality …

The Effect Of Hydrostatic Pressure On Bladder Smooth Muscle Cell Function, Margaret Drumm

All Theses

Previous research has demonstrated that bladder smooth muscle cells (BSMC) respond to various forms of mechanical stimuli, including stretch and hydrostatic pressure, by increases of cell proliferation, activation of intracellular signaling pathways, and alteration of contractile and synthetic marker protein expression. These cellular/molecular level changes are all indicative of a BSMC phenotypic shift that can negatively impact the bladder function at the tissue and organ level. The objective of the present study is to test a hypothesis that bladder SMCs shift their phenotype from contractile to synthetic in response to elevated hydrostatic pressure. Rat bladder SMC cultures were exposed to …

Growth And Modeling Of Freshwater Algae As A Function Of Media Inorganic Carbon Content, Mary Watson

All Theses

In response to global climate change, the Department of Energy (DOE) has specified advanced biological processes, such as cultivation of algal biomass in alkaline ponds, as part of a carbon management plan. The goal of this thesis was to investigate use of a mixed freshwater algal culture for biological carbon mitigation. Extensive review of carbonate dynamics, laboratory investigations to characterize algal growth, and development of a dynamic algal growth model were completed.
The presented literature review summarizes carbonate equilibria and kinetics needed for development of carbon mitigation technologies, especially in freshwaters. Reaction mechanisms, equilibrium relationships, kinetic rate constants, and kinetic …

Investigation Of Training Algorithms For Hidden Markov Models Applied To Automatic Speech Recognition, Eric Fang

All Theses

The work presented in this thesis focuses on simulating a speech recognizer which is trained by different people with different speaking styles and investigates how sensitive the training and recognition processes are to the variations in the training data. There are four main parts to this work. The first involves an experiment of weighting methods for training with multiple observation sequences. The second involves the testing of different initial parameters. The third part includes the first experiment involving training with multiple observation sequences. The model's sensitivity to variations in training data was evaluated by comparing the cases of different values …

A Pulsatile Bioreactor For Conditioning Tissue Engineered Heart Valves, Leslie Sierad

All Theses

Tissue engineered constructs with autologous adult stem cells capable of self-repair and growth are highly desired replacements for diseased heart valves. However, the current approaches have inadequate mechanical properties to withstand in vivo implantation. Therefore, our group hypothesized that an in vitro environment of physiological intra-cardiac pressures and flow will stimulate stem cells to differentiate and remodel valvular scaffold constructs before implantation.
The group developed a pneumatic-driven conditioning system (Aim I) consisting of a three-chambered heart valve bioreactor, a pressurized compliance tank, a reservoir tank, one-way valves, pressure-retaining valves, and pressure transducers. The system can be sterilized using conventional autoclaving …

The Effect Of Bond Strength Of Flexible Laminates On Puncture Resistance, Rijosh Cheruvathur

All Theses

This work was aimed at understanding whether the bond strength of laminates will affect the puncture resistance of the laminate. Even though a strongly bonded adhesive layer in between two webs will considerably improve the mechanical properties of the laminate compared to that of the individual materials, there is a general belief in the packaging industry that having a lower bond strength helps to improve the bending or, in other words, the flexibility of the laminate thereby increases the tear and puncture resistance.
Laminations of aluminum foil and polyethylene terephthalate (PET) were used as a model system to determine the …

Wide Operating Range For A Circular Waveguide Probe In Spherical Near-Field Measurements, Xiong Wang

All Theses

This thesis discusses spherical near-field measurements implemented by a circular waveguide probe which has much shorter length and wider operating range than those proposed similar circular probes. A brief introduction of spherical near-field measurement techniques is provided first. We also introduce the well-known conclusion that utilizing first-order probes simplifies the measurements and associated near-field to far-field transformation. Accordingly, a relatively short circular waveguide probe antenna is designed and fabricated. Detailed fields of this probe are analyzed to demonstrate that it is still a first-order probe even though the length is short. Furthermore, it radiates only first-order fields over a wide …

Fast Generation Of Receiver-Based Statistics In Frequency Hop Radios Without Decoder Simulation, Michael Masse

All Theses

Receiver-based statistics can contain useful information about the quality a wireless channel. We examine methods of generating receiver statistics without real-time simulation of the receiver and the decoder, particularly during a network-level simulation. Attention is restricted to a receiver employing binary orthogonal signaling, noncoherent demodulation, and a soft-decision decoder in a frequency-hop network. Data is gathered from off-line simulations of channel, demodulation, and decoding processes, using a family of turbo product codes. Study and analysis of the data are used to characterize the behavior of the receiver statistics and determine on-line methods of generating the statistics in network-level simulations. To …

Development, Parameterization And Validation Of Dynamic Material Models For Soil And Transparent Armor Glass, Bhaskar Pandurangan

All Dissertations

Despite the signing of several mine ban treaties in the 1990's, it is widely recognized that there is a landmine crisis. The following are some of the main aspects of this crisis: (a) Millions of unexploded landmines remain deployed all over the world; (b) Thousands of civilians are killed or maimed every year by unintended detonations of the mines; (c) The cost of medical treatment of landmine injuries runs into the millions; (d) the ability of the international community to provide the humanitarian relief in terms of medical services, safe drinking water and food, etc., is greatly hampered by landmine …

Surface And Bulk Modification Of Poly(Lactic Acid), Rahul Rasal

All Dissertations

The major drawbacks of PLA are its poor toughness and lack of readily reactable groups. Unfortunately, typical methods of PLA toughening are associated with significant modulus and/or ultimate tensile strength (UTS) loss. The main objective of this research was to toughen PLA, with minimal modulus and/or UTS loss, and introduce reactive groups into the PLA matrix in one step. Initially, this objective was divided into two separate parts: PLA surface modification followed by toughening.
PLA film was solvent cast from chloroform solution and was surface modified using a sequential two-step photografting approach. Benzophenone was photografted onto the film surface in …

Adsorption-Induced Changes In Enzyme Bioactivity Correlated With Adsorbed Protein Orientation And Conformation, Kenan Fears

All Dissertations

Systems using immobilized enzymes are attractive for a wide range of industrial and medical applications because they allow for fabrication of stable, reusable substrates with a highly specific functionality. The performance of these systems is greatly influenced by the orientation and conformation of the immobilized enzymes. To investigate these relationships, we have developed and applied methods to quantitatively assess the secondary structure of adsorbed enzyme layers on planar surfaces using circular dichroism (CD) spectropolarimetry and evaluate their bioactivity using colorimetric assays. When combined with knowledge of an enzyme's native structure, these methods provide a means to correlate changes in enzyme …

Development Of The Integrated Censored Robust-Tolerance Engineering Design Systems Via Improved Response Surface Modeling, Abdul-Baasit Shaibu

All Dissertations

In this dissertation, we intend to integrate censoring into robust-tolerance engineering using improved dual response surface modeling. This is perhaps the first attempt in the quality control literature. In the literature, response surface models have largely been restricted to second order (or quadratic) models and robust-tolerance designs have been restricted to situations involving complete observations. We intend to show that higher order response surface models can be more powerful in terms of prediction ability, and are therefore more reliable than the preferred quadratic models in the general context of robust design. We will also consider formulating robust and tolerance designs …

Foundations Of Design Method Development, Sudhakar Teegavarapu

All Dissertations

A systematic procedure for developing design methods, tools, and/or processes, referred to as meta-method, is proposed. It is hypothesized that design methods developed without following a systematic procedure are not effective and thus are not widely accepted by industry and academia likewise. The systematic framework provided by the meta-method will ensure 1) faster development of design methods, 2) enable tracking of requirements throughout the development process, 3) facilitate efficient exploration and selection of alternatives, 4) document the development process for future reuse, 5) help in testing and validation of design methods, and 6) bridge gap between multiple disciplines by forming …

Development Of A Methodology For Evaluating And Anticipating Improvised Explosive Device Threat Activity Using A Fault Tree Based Process, Benjamin Bennett

All Dissertations

This document is a redacted version of the original dissertation titled 'Development of a Methodology for Evaluating and Anticipating Improvised Explosive Device Threat Activity Using a Fault Tree Based Process.' To allow for publication, information was removed which was considered sensitive in nature or which could be used by those who employ the Improvised Explosive Device, to negate any advantage gained by this research. The complete un-redacted dissertation is available (with proper vetting) to those whishing to further develop the concepts outlined in this document. Those interested in obtaining access to the complete document should contact the Joint IED Defeat …

Microcantilever-Based Force Sensing, Control And Imaging, Reza Saeidpourazar

All Dissertations

This dissertation presents a distributed-parameters base modeling framework for microcantilever (MC)-based force sensing and control with applications to nanomanipulation and imaging. Due to the widespread applications of MCs in nanoscale force sensing or atomic force microscopy with nano-Newton to pico-Newton force measurement requirements, precise modeling of the involved MCs is essential. Along this line, a distributed-parameters modeling framework is proposed which is followed by a modified robust controller with perturbation estimation to target the problem of delay in nanoscale imaging and manipulation. It is shown that the proposed nonlinear model-based controller can stabilize such nanomanipulation process in a very short …

Production Of Biobutanol From Biomass Using Novel Membrane Reactor: A P3 Experience, Ellen Draehn

Chemical Engineering Undergraduate Honors Theses

Producing biobutanol from a waste product on a large scale is a novel idea. Because of this, there is very little research available in this area. Previous fermentation research has primarily focused on the production of ethanol or biobutanol using cellulosic or agricultural feed stocks. The Phase I research team, Team R azorbacks E ngineering FU el S olutions for E veryone (Team REFUSE), sought to design a fermentation process that would produce butanol from food waste. Team REFUSE cultivated a partnership with Chartwells, the campus food service provider for the University of Arkansas, for the acquisition of food waste. …

Proximate Characterization And Lycopene Determination In Bitter Melon Seed Aril, Luis Raul Jimenez Interiano

Chemical Engineering Undergraduate Honors Theses

Bitter melon aril is the mucilage covering the fruit's seeds which could contain beneficial dietary ingredients. The bright red color of bitter melon aril suggests that it could contain lycopene. The purpose of this study was to determine the proximate composition of bitter melon aril and to explore this material as a potential rich source of lycopene that has health benefits. Bitter melon aril from Sri Lanka, harvested in Arkansas, USA in 2005, 2006, and 2007 was analyzed. An investigation to develop an extraction method for lycopene from bitter melon was performed using liquid-liquid and a polar liquid extraction. The …

Understanding The Effects Of Hydrophobicity For The Detection Of Methylated Dna By Microchannel Electrophoresis, Micah Fritsche

Chemical Engineering Undergraduate Honors Theses

DNA methylation is an epigenetic mechanism used for long - term silencing of gene expression. This silencing of gene expression can be involved in the down regulation of genes involved in apoptosis, which is a process of regulated cell death, and this inability to break down cells can ultimately lead to tumor formation in cancer. Methylation of DNA follows a certain pattern through developmental stages of an individual, and this pattern is normally maintained throughout that individual's life. However, in the DNA of older individuals, this methylation is commonly seen to be altered. This altered pattern of methylation can be …

Hot Mix Asphalt Longitudinal Joint Evaluation, Annette Porter

Civil Engineering Undergraduate Honors Theses

Longitudinal joints are the portion of the road where two lanes meet and are formed because the lanes are paved at different times. Longitudinal joints tend to be the weakest portion of the roadway, and yet few regulations exist to control their quality. Currently, Arkansas specifications for asphalt pavement do not include any requirements for the measurement of joint quality. The purpose of this research project is to determine the most effective method for evaluating longitudinal joints in hot-mix asphalt (HMA) pavements. Most of the literature concerning longitudinal joints focuses on density as the determining factor of quality because density …