Engineering Commons^™

The Perceived Benefits Of Automotive Service Excellence (Ase) Certifications For Graduates Of Four-Year Automotive Technology Programs, John Thompson

Graduate Theses and Dissertations

The roots of certification in America date back to guild-like associations similar to those in Europe, but did not gain industry recognition until after World War II. It is recognized as a way for an industry to elevate itself and be recognized as a stand-alone, autonomous profession, as long as there is validity in the process and impartial oversight by an accredited governing body. It is also a way for individuals to distinguish themselves from their peers by proving a technical aptitude or competence. It allows a prospective job candidate to signal to a potential employer that they have attained …

Designing Magnetically Responsive Ultrafiltration Membranes, Robert William Dong

Graduate Theses and Dissertations

Ultrafiltration (UF) membranes developed out of a need for protein separation processes. Currently, they are used in a variety of industries ranging from food manufacturing to pharmaceuticals for two main purposes: concentration, separation, and buffer exchange. UF membrane processes in product streams undergo frequent use and like all membrane processes experience a gradual decline in performance due to fouling phenomena both irreversible and reversible. Ultimately, performance declines to a point where the UF membrane needs to be replaced. Frequent replacement of UF membranes is detrimental to major industries that require high product throughput using UF processes. Thus, it is important …

Technology Mapping, Design For Testability, And Circuit Optimizations For Null Convention Logic Based Architectures, Farhad Alibeygi Parsan

Graduate Theses and Dissertations

Delay-insensitive asynchronous circuits have been the target of a renewed research effort because of the advantages they offer over traditional synchronous circuits. Minimal timing analysis, inherent robustness against power-supply, temperature, and process variations, reduced energy consumption, less noise and EMI emission, and easy design reuse are some of the benefits of these circuits. NULL Convention Logic (NCL) is one of the mainstream asynchronous logic design paradigms that has been shown to be a promising method for designing delay-insensitive asynchronous circuits.

This dissertation investigates new areas in NCL design and test and is made of three sections. The first section discusses …

A Strategic Approach To Effectively Manage Supplier Quality Within The Construction Industry, Rufaidah Almaian

Graduate Theses and Dissertations

The aim of the research is to determine the best practices for supplier quality management (SQM) in the construction industry that ensure that the supplied materials and equipment for construction projects are within the quality requirements. The research is based on three main objectives. The first objective is to describe and assess the process of assuring supplier quality inside and outside the construction industry. The second objective is to develop a framework for the supplier quality process based on the collection of SQM practices from multiple data sources. The third objective is to assess the SQM practices within the developed …

Study Of Parallel Programming Models On Computer Clusters With Accelerators, Chenggang Lai

Graduate Theses and Dissertations

In order to reach exascale computing capability, accelerators have become a crucial part in developing supercomputers. This work examines the potential of two latest acceleration technologies, Intel Many Integrated Core (MIC) Architecture and Graphics Processing Units (GPUs). This thesis applies three benchmarks under 3 different configurations, MPI+CPU, MPI+GPU, and MPI+MIC. The benchmarks include intensely communicating application, loosely communicating application, and embarrassingly parallel application. This thesis also carries out a detailed study on the scalability and performance of MIC processors under two programming models, i.e., offload model and native model, on the Beacon computer cluster.

According to different benchmarks, the results …

Design Of A High Performance Silicon Carbide Cmos Operational Amplifier, Shaila Amin Bhuyan

Graduate Theses and Dissertations

This thesis presents the design, simulation, layout and test results of a silicon carbide (SiC) CMOS two-stage operational amplifier (op amp) with NMOS input stage. The circuit has been designed to provide a stable open-loop voltage gain (60 dB), unity-gain bandwidth (around 5 MHz) and maintain a high CMRR and PSRR within a useful input common mode range over process corners and a wide temperature range (25 °C - 300 °C). Between the two stages a Miller compensation topology is placed to improve the phase margin (around 45°). Due to the comparatively high threshold voltage values of transistors in SiC, …

Development And Characterization Of An Autologous Whole Cell Breast Cancer Vaccine, Samantha Leigh Kurtz

Graduate Theses and Dissertations

Approximately 40,000 women will die from breast cancer in the United States in 2014. About 90% of these deaths will be due to metastases, rather than the primary tumor and majority of metastases are due to the recurrence and progression of non-metastatic disease. Current adjuvant treatments, such as chemotherapy and radiation, have severe side effects and may result in overtreatment and drug resistance.

Since greater than 90% of patients are diagnosed between stages I-III and have minimal residual disease after treatment, there is an opportunity to treat patients with an autologous breast cancer vaccine. Autologous vaccines under development have a …

A Phase-Locked Loop In High-Temperature Silicon Carbide And General Design Methods For Silicon Carbide Integrated Circuits, Paul Shepherd

Graduate Theses and Dissertations

Silicon carbide (SiC) has long been considered for integrated circuits (ICs). It offers several advantages, including wider temperature range, larger critical electric field, and greater radiation immunity with respect to Silicon (Si). At the same time, it suffers from challenges in fabrication consistency and lower transconductance which the designer must overcome. One of the recent SiC IC processes developed is the Raytheon High-Temperature Silicon Carbide (HTSiC) complementary MOSFET process. This process is one of the first to offer P channel MOSFETs and, as a result, a greater variety of circuits can be built in it.

The behavior of SiC MOSFETs …

Design Of System Level Control For A Residential Power Router, Fahad Hossain

Graduate Theses and Dissertations

This thesis presents the overall power flow and load management system for a 2 kW residential power router. The objective is to satisfy the residential load demand with cost savings by managing the energy sources including PV, battery, generator, and grid. The power flow management system algorithm is developed both for grid-connected mode and island mode. This algorithm involves the battery state of charge estimation, available PV power, load demand and electricity grid pricing. The residential load management algorithm is also developed using PV power prediction and load power prediction acquired for a day.¬ A Labview GUI is also developed …

Development Of A Novel Device For The Perfusion Driven Decellularization Of Skeletal Muscle, Benjamin Kasukonis

Graduate Theses and Dissertations

Decellularization of skeletal muscle is a process that removes cellular components of skeletal muscle tissue while leaving behind the intact extracellular matrix (ECM). Skeletal muscle ECM is currently being studied as a biologic scaffold for repairing volumetric muscle loss (VML) because the removal of cells greatly reduces the antigenicity of the donor tissue. Decellularization usually relies on passive diffusion of detergents, surfactants and/or osmotic solutions to strip cells from the ECM. However, passive diffusion alone is usually not sufficient for complete removal of cells from the interior of large pieces of skeletal muscle using detergents, such as sodium dodecyl sulfate …

Design, Simulation And Implementation Of Three-Phase Bidirectional Dc-Dc Dual Active Bridge Converter Using Sic Mosfets, Tariq Aldawsari

Graduate Theses and Dissertations

The use of SiC-based martials in fabricating power semiconductor devices has shown more interest than conventional silicon-based. Its promising abilities to improve the performance of power electronic systems made it a valuable choice in building high power DC-DC converters. This thesis presents the design and implementation of a three-phase bidirectional DC-DC Dual Active Bridge using SiC MOSFETs. The proposed circuit is first built in Matlab for simulation analysis. Then a phase shift modulation controller is designed in Simulink to test the simulation circuit. The controls are then integrated through an FPGA to test the prototype. Simulations and experimental results are …

Integration Of Energy Storage Into A Future Energy System With A High Penetration Of Distributed Photovoltaic Generation, Arthur K. Barnes

Graduate Theses and Dissertations

Energy storage units (ESU) are increasingly used in electrical distribution systems because they can perform many functions compared with traditional equipment. These include peak shaving, voltage regulation, frequency regulation, provision of spinning reserve, and aiding integration of renewable generation by mitigating the effects of intermittency.

As is the case with other equipment on electric distribution systems, it is necessary to follow appropriate methodologies in order to ensure that ESU are installed in a cost-effective manner and their benefits are realized. However, the necessary methodologies for integration of ESU have not kept pace with developments in both ESU and distribution systems. …

Potential For Optical Sensor-Based Nitrogen Fertilization In Grain Sorghum (Sorghum Bicolor L. Moench) In Arkansas, Kamil H. Rosales Rodriguez

Graduate Theses and Dissertations

Ground-based active-optical (GBAO) crop sensors have become an effective tool to improve nitrogen (N) use efficiency and to predict yield early in the growing season, particularly for grass crops. Commercially available canopy sensors calculate the normalized difference vegetative index (NDVI) by emitting light in the red and near infrared range of the electromagnetic spectrum. The NDVI is used to evaluate vigor status and to estimate yield potential. However, few studies have been conducted to compare the performance of commercially available sensors. Therefore, a study was conducted using the most common crop canopy sensors: i) N-Tech's GreenSeeker^TM (GS), ii) Holland …

Truckload Shipment Planning And Procurement, Neo Nguyen

Graduate Theses and Dissertations

This dissertation presents three issues encountered by a shipper in the context of truckload transportation. In all of the studies, we utilize optimization techniques to model and solve the problems. Each study is inspired from the real world and much of the data used in the experiments is real data or representative of real data.

The first topic is about the freight consolidation in truckload transportation. We integrate it with a purchase incentive program to increase truckload utilization and maximize profit. The second topic is about supporting decision making collaboration among departments of a manufacturer. It is a bi-objective optimization …

Designing And Implementing A Micro-Controller Based Primary-Side Sensing Flyback Converter For Leds Driver, Nam Nhat Tran

Graduate Theses and Dissertations

The fast development of LED and its applications has enabled a new generation of lighting device with higher efficiency and long lifespan. By employing a primary-side sensing flyback converter and the PIC18F micro-controller series, an LED driver could achieve two important features: (1) the compatibility with the available lighting fixtures, and (2) reducing unit price. The flyback converter was chosen for its simplicity, competitive low cost, and its ability to provide a constant output current, a necessarily important factor to an LED driver. Meanwhile, the PIC18F micro-controller series offer numerous advanced features which include but not limited to pulse-width modulation …

Atomistic Simulation And Virtual Diffraction Characterization Of Alumina Interfaces: Evaluating Structure And Stability For Predictive Physical Vapor Deposition Models, Shawn Patrick Coleman

Graduate Theses and Dissertations

The objectives of this work are to investigate the structure and energetic stability of different alumina (Al₂O₃) phases using atomistic simulation and virtual diffraction characterization. To meet these objectives, this research performs molecular statics and molecular dynamics simulations employing the reactive force-field (ReaxFF) potential to model bulk, interface, and surface structures in the θ-, γ-, κ-, and α-Al₂O₃ system. Simulations throughout this study are characterized using a new virtual diffraction algorithm, developed and implemented for this work, that creates both selected area electron diffraction (SAED) and x-ray diffraction (XRD) line profiles without assuming …

Mitigation Of Alkali-Silica Reaction (Asr) In An Interstate Median Barrier, Richard Albert Deschenes

Graduate Theses and Dissertations

In 2012 it was discovered that roughly 4 miles of interstate median barrier along Interstate 540 had rapidly deteriorated. After the initial inspection, a sample was submitted for analysis, and found to contain evidence of alkali-silica reaction (ASR). A research program was implemented with the goal of determining the cause of ASR and developing a program for mitigating the ongoing deterioration. The median barrier had not deteriorated equally throughout the 4 miles, and the level of damage varied considerable throughout the length. A visual inspection of the median barrier was conducted and the median barrier was divided into sections based …

Durability Of Silane Sealer In A Highly Alkaline Environment, Cameron David Murray

Graduate Theses and Dissertations

Alkali-silica reaction (ASR) is a chemical reaction between siliceous minerals present in certain aggregates and alkalis in the concrete pore solution. The reaction can lead to expansion and severe damage in concrete members. One method to mitigate ASR expansion is to use a penetrating sealer such as silane. A set of columns located in a food preparation facility was treated with silane and a complimentary laboratory study was performed. A cleaning regimen involving application of an alkaline cleaner is employed at the facility, followed by rinsing with hot, pressurized water. The purpose of this research is to evaluate the effectiveness …

Dynamic Testing Of An Elevated Water Tank, Alexander Michael Font

Graduate Theses and Dissertations

The objective of this thesis was to identify the modal properties of a pedesphere type, elevated water tank under different operating conditions relating to the water level in the tank. The research that was conducted included both numerical and experimental components. The numerical components consisted of a simple hand calculation to identify the fundamental frequency as well as numerical computer models to identify the natural frequencies and mode shapes for the first three bending modes. The experimental components consisted of characterizing the vibration of the elevated water tank in its current environment through ambient vibration testing.

Multiple Reference Impact Testing Of Bridges Using A Network Of Low-Cost Dynamic Exciters, James David Lindsey

Graduate Theses and Dissertations

Multiple Reference Impact Testing (MRIT) is a form of Experimental Modal Analysis (EMA) that can be used to identify the dynamic properties of full-scale bridges. These dynamic properties include natural frequencies, mode shapes, damping ratios, modal scaling and modal flexibility. Since these system properties that are directly related to the mass and stiffness characteristics of a structure, impact test measurements can be used to quantitatively characterize condition of a structure. Over time, changes in the properties can be monitored and evaluated as indicators of damage or deterioration. Instrumented hammers and drop masses are typically used to perform MRIT by providing …

Field-Obtained Soil Water Characteristic Curves And Hydraulic Conductivity Functions, Elvis Ishimwe

Graduate Theses and Dissertations

A compacted clay liner (test pad) was constructed and instrumented with volumetric water content and soil matric potential sensors to determine soil water characteristic curves (SWCC) and hydraulic conductivity (k) functions. Specifically, the compacted clay liner was subjected to an infiltration cycle during a sealed double ring infiltrometer (SDRI) test followed by a drying cycle. After the drying cycle, Shelby tube samples were collected from the compacted clay liner and flexible wall permeability (FWP) tests were conducted on sub-samples to determine the saturated hydraulic conductivity. Moreover, two computer programs (RETC and UNSAT-H) were utilized to model the SWCCs and k-functions …

Software Porting Of A 3d Reconstruction Algorithm To Razorcam Embedded System On Chip, Kevin Curtis Gunn

Graduate Theses and Dissertations

A method is presented to calculate depth information for a UAV navigation system from Keypoints in two consecutive image frames using a monocular camera sensor as input and the OpenCV library. This method was first implemented in software and run on a general-purpose Intel CPU, then ported to the RazorCam Embedded Smart-Camera System and run on an ARM CPU onboard the Xilinx Zynq-7000. The results of performance and accuracy testing of the software implementation are then shown and analyzed, demonstrating a successful port of the software to the RazorCam embedded system on chip that could potentially be used onboard a …

Self-Assembly Of Gold Nanosphere Dimers By Inertial Force, George Andrew Christopher Sakhel

Graduate Theses and Dissertations

The morphology and composition of a nanoparticle (NP) play a critical role in determining the NP's properties and function. To date, researchers have created a myriad of NPs of different shapes, sizes, and compositions with interesting attributes and applications ushering a revolution in medicine, electronics, microscopy, and microfluidics.

In this study, gold (Au) nanosphere dimers (NSDs) have been synthesized through a novel self-assembly method. These particles were created from Au NPs mono-dispersed in aqueous solution via a process of centrifugation and capping agent replacement. Au NSDs consist of two Au NPs combined together with minimal gaps between them. Optical spectral …

Disruption Response Support For Inland Waterway Transportation, Jingjing Tong

Graduate Theses and Dissertations

Motivated by the critical role of the inland waterways in the United States' transportation system, this dissertation research focuses on pre- and post- disruption response support when the inland waterway navigation system is disrupted by a natural or manmade event. Following a comprehensive literature review, four research contributions are achieved. The first research contribution formulates and solves a cargo prioritization and terminal allocation problem (CPTAP) that minimizes total value loss of the disrupted barge cargoes on the inland waterway transportation system. It is tailored for maritime transportation stakeholders whose disaster response plans seek to mitigate negative economic and societal impacts. …

A Novel Cell Based Assay For Mmp Inhibitor Screening, Pantrika Krisanarungson

Graduate Theses and Dissertations

Up to date, a plethora of protein based materials are used as implants to stimulate tissue regeneration or fillers to alleviate tissue or organ impairment. This includes glottal insufficiency, urinary bladder incontinence and especially in cosmetic industrial to improve facial contour. Once in vivo, protein-based materials are decomposed by cell secreted matrix metalloproteinases (MMP) and lose their volume within months. By introducing MMP inhibitor (MMPI), the extent of material degradation over time may be reduced. In this dissertation, the development of cell-based assay capable of identifying MMPI candidates for protein-based implant lifetime prolongation is described. To visualize the degradation, DQ-gelatin, …

Large-Scale Solution Approaches For Healthcare And Supply Chain Scheduling, Ridvan Gedik

Graduate Theses and Dissertations

This research proposes novel solution techniques for two real world problems. We first consider a patient scheduling problem in a proton therapy facility with deterministic patient arrivals. In order to assess the impacts of several operational constraints, we propose single and multi-criteria linear programming models. In addition, we ensure that the strategic patient mix restrictions predetermined by the decision makers are also enforced within the planning horizon. We study the mathematical structures of the single criteria model with strict patient mix restrictions and derive analytical equations for the optimal solutions under several operational restrictions. These efforts lead to a set …

Nanofabrication Of Metallic Nanostructures And Integration With Light Detection Devices, Liang Huang

Graduate Theses and Dissertations

Metallic nanostructures have been investigated with various applications especially for integration with light detection devices. The incident light can be manipulated by those nanostructures to enhance light absorption therefor improve device performance. However, previous studies focused on optical design. The electrical properties of these integrated light detection devices have not been fully considered. The photon generated carriers transport and collection are critical for light detection devices as well. An optimized device platform considering from both the optical and electrical aspects to fully utilize these nanostructures is highly desired for future light detection devices.

This dissertation targeted on three objectives, beginning …

Nanoscale Manipulation Of Pristine And Functionalized Freestanding Graphene Using Scanning Tunneling Microscopy, Matthew Ackerman

Graduate Theses and Dissertations

Over the past ten years the 2D material graphene has attracted an enourmous amount of attention from researchers from across diciplines and all over the world. Many of its outstanding electronic properties are present only when it is not interacting with a substrate but is instead freestanding. In this work I demonstrate that pristine and functionalized freestanding graphene can be imaged using a scanning tunneling microscope (STM) and that imaging a flexible 2D surface is fundamentally different from imaging a bulk material due to the attraction between the STM tip and the sample. This attraction can be used to manipulate …

Optimization Of Plasmon Decay Through Scattering And Hot Electron Transfer, Drew Dejarnette

Graduate Theses and Dissertations

Light incident on metal nanoparticles induce localized surface oscillations of conductive electrons, called plasmons, which is a means to control and manipulate light. Excited plasmons decay as either thermal energy as absorbed phonons or electromagnetic energy as scattered photons. An additional decay pathway for plasmons can exist for gold nanoparticles situated on graphene. Excited plasmons can decay directly to the graphene as through hot electron transfer. This dissertation begins by computational analysis of plasmon resonance energy and bandwidth as a function of particle size, shape, and dielectric environment in addition to diffractive coupled in lattices creating a Fano resonance. With …

Electroencephalography(Eeg) Data Collection And Processing Through Machine Learning, Jayshree Desai

Graduate Theses and Dissertations

Machine learning methods are an excellent way for understanding the neural basis of human decision making. Some machine learning systems try to eradicate the need for human intuition in data analysis whereas others embrace a collective approach between humans and machines. The objective of this project is to collect Electroencephalography (EEG) signals through wireless sensors, and the process the collected signals through machine learning methods. The EEG data is collected using three EEG electrodes, each being the positive, negative and ground terminals respectively. Since the signal measures in the unit of micro-volts it needs to be amplified using amplifier circuit. …