Engineering Commons^™

Shape Optimization Of Turbomachinery Blades Using An Adjoint Harmonic Balance Method, Huang Huang

Doctoral Dissertations

The high-dimensional harmonic balance (HDHB) method has recently become popular in the field of periodic unsteady flow prediction due to its accuracy and high efficiency. In the present dissertation research, two and three-dimensional parallelized computational fluid dynamic (CFD) codes based on the HDHB method are developed and validated for unsteady turbulent flows. It is found that the stability condition for an explicit solver is highly dependent on the reduced grid frequency, a non-dimensional parameter that depends on the grid size, characteristic wave speed, and the highest frequency retained in the harmonic balance solver. Furthermore, for certain moderately and highly nonlinear …

System Studies Of Fission-Fusion Hybrid Molten Salt Reactors, Robert D. Woolley

Doctoral Dissertations

This work proposes and evaluates a Fission-Fusion Hybrid Molten Salt Reactor (FFHMSR), combining two subsystems, a deuterium + tritium (DT) fusion reactor surrounded by a neutron-absorbing Fusion Blanket (FB) and a critical Molten Salt fission Reactor (MSR). The molten salt, which contains dissolved actinides, circulates at a high rate between them.

As envisioned the MSR exhibits the large Conversion Ratio of graphite moderated reactors having small fissile and large fertile inventories. DT fusion neutrons irradiating actinides in the molten salt release additional neutrons which increase isotope conversion and fission. Actinide fuel is continually added while fission products are continually removed …

Decoding The `Nature Encoded' Messages For Wireless Networked Control Systems, Shuping Gong

Doctoral Dissertations

Because of low installation and reconfiguration cost wireless communication has been widely applied in networked control system (NCS). NCS is a control system which uses multi-purpose shared network as communication medium to connect spatially distributed components of control system including sensors, actuator, and controller. The integration of wireless communication in NCS is challenging due to channel unreliability such as fading, shadowing, interference, mobility and receiver thermal noise leading to packet corruption, packet dropout and packet transmission delay. In this dissertation, the study is focused on the design of wireless receiver in order to exploit the redundancy in the system state, …

Monte Carlo And Depletion Reactor Analysis For High-Performance Computing Applications, Brenden Thomas Mervin

Doctoral Dissertations

This dissertation discusses the research and development for a coupled neutron trans- port/isotopic depletion capability for use in high-preformance computing applications. Accurate neutronics modeling and simulation for \real" reactor problems has been a long sought after goal in the computational community. A complementary \stretch goal" to this is the ability to perform full-core depletion analysis and spent fuel isotopic characterization. This dissertation thus presents the research and development of a coupled Monte Carlo transport/isotopic depletion implementation with the Exnihilo framework geared for high-performance computing architectures to enable neutronics analysis for full-core reactor problems.

An in-depth case study of the current …

Design And Development Of Seed Hydration Analyzing Device And Its Utilization In Studying Cereal And Legume Hydration, Vinay Kumar Mannam

Doctoral Dissertations

Cereals and legumes are important sources of vegetable-based human nutrition. Together they account for 48.6 % of protein and 8.7 % carbohydrate consumption around the world. During preparation, majority of these agricultural staples are re-hydrated to aid in their digestibility, palatability and the bio-availability of the nutrients.

Study of hydration kinetics of cereals and legumes is an important and valuable necessity for industry and academia to understand and gain insights into seed hydration characteristics. An automatic seed hydration analyzing system is developed as a solution for lack of instruments with broad capabilities to study variety of seed properties. The device …

Structure And Energetics Of Nanoparticles And Ionomer Films In Fuel Cell Catalyst Layers, Qianping He

Doctoral Dissertations

Improving the durability and utilization efficiency of the platinum-on-carbon (Pt/C) catalyst is of vital importance to the commercialization of the polymer electrolyte membrane fuel cell (PEMFC). This body of work provides molecular level insights to aid the fulfillment of this goal. Chapter 1 describes the use of molecular dynamics (MD) simulation in an effort to understand the Pt/C degradation issue from the nano-adhesion point of view. The roles of catalyst nanoparticle size, shape, Pt/C surface oxidation and the extent of ionomer film hydration are investigated to study their effects on nano-particle adhesion. It is found that the adhesion force strengthens …

Fundamental Studies Of Single Crystal Alpha Alumina Microstructures Produced By Irradiation With Zirconium Ions, Younes Sina

Doctoral Dissertations

This research has discovered the following new information:

a) The threshold fluence for amorphization of single crystal α-Al₂O₃ [alpha alumina] samples irradiated with 175 keV Zr⁺ [Zr+] ions at room temperature is 1.5×10¹⁶ [1.5E16] Zr/cm² [Zr+/cm2] which is a much lower fluence than the previously thought.

b) A buried amorphous layer sandwiched between two highly-damaged crystalline regions was observed in samples irradiated with 175 keV Zr⁺ to a fluence of 1.5×10¹⁶ Zr⁺/cm² and higher at room temperature.The amorphous region contains short range order similar to γ-Al₂O_{3 …}

Effects Of Data Resolution And Human Behavior On Large Scale Evacuation Simulations, Wei Lu

Doctoral Dissertations

Traffic Analysis Zones (TAZ) based macroscopic simulation studies are mostly applied in evacuation planning and operation areas. The large size in TAZ and aggregated information of macroscopic simulation underestimate the real evacuation performance. To take advantage of the high resolution demographic data LandScan USA (the zone size is much smaller than TAZ) and agent-based microscopic traffic simulation models, many new problems appeared and novel solutions are needed. A series of studies are conducted using LandScan USA Population Cells (LPC) data for evacuation assignments with different network configurations, travel demand models, and travelers’ compliance behavior.

First, a new Multiple-Source-Nearest-Destination Shortest Path …

Bayesian Dictionary Learning For Single And Coupled Feature Spaces, Li He

Doctoral Dissertations

Over-complete bases offer the flexibility to represent much wider range of signals with more elementary basis atoms than signal dimension. The use of over-complete dictionaries for sparse representation has been a new trend recently and has increasingly become recognized as providing high performance for applications such as denoise, image super-resolution, inpaiting, compression, blind source separation and linear unmixing. This dissertation studies the dictionary learning for single or coupled feature spaces and its application in image restoration tasks. A Bayesian strategy using a beta process prior is applied to solve both problems.

Firstly, we illustrate how to generalize the existing beta …

Wide-Area Measurement And Applications In Power System Dynamic Modeling And Control, Yong Liu

Doctoral Dissertations

Synchrophasor has been becoming the foundational element of power grid wide-area measurement system (WAMS) since first developed in 1980s. By utilizing global positioning system (GPS) time synchronization technique, synchrophasors offer highly accurate time-synchronized phasor measurements that can provide system operators with real-time information of operation status.

Frequency disturbance recorders (FDRs) are installed on the distribution level to measure power system dynamics and considered as a type of single-phase synchrophasors. In this dissertation, a detailed procedure for the FDRs’ calibration is summarized and a preliminary test of their dynamic performance is carried out. Moreover, this dissertation investigates the impact of GPS …

All-Sic Three-Phase Converters For High Efficiency Applications, Fan Xu

Doctoral Dissertations

The dissertation aims to improve the efficiency of three-phase converters using SiC power devices.The methodology to design a high efficiency all-SiC three-phase converter is presented. Four aspects are included: SiC power device evaluation, power loop parasitics analysis, high efficiency current source rectifier, and paralleled current source rectifier system.

The SiC JFET and MOSFET are tested based on voltage source and current source structures respectively. The dissertation proposes a device switching test circuit based on current source topology to simulate current commutation processes. The circuit can evaluate the switching performance and calculate switching loss of a power device used in a …

A Tale Of Two Protein Switches: Engineering, Characterizing, And Understanding A Novel And A Natural Switch, James Vincent Price

Doctoral Dissertations

Throughout nature, many proteins provide a specific function in response to some input signal (e.g., phosyphorylation, pH, etc.), a process that is oftentimes described as switching a protein “on” or “off.” The advent of protein engineering has allowed for the creation and understanding of chimeric proteins for uses in a number of applications such as therapeutics, biosensors and energy production. Two proteins, hemagglutinin (HA) of fowl plague influenza virus and a chimeric protein comprising a fusion between the LFA-1 I domain and the EF3 and EF4 hands of calmodulin, have been investigated in this dissertation. Both of these proteins undergo …

Investigation Of Asphalt Pavement Mixture Blending Utilizing Analytical Chemistry Techniques, Benjamin Frank Bowers

Doctoral Dissertations

The use of Reclaimed Asphalt Pavement (RAP) in new pavement mixtures is a topic of interest throughout the transportation industry and academia due its economic and environmental implications. There is concern however about how well the binder from the RAP blends with new, virgin binder when the mixture is created. Insufficient blending of the aged and unaged binders may compromise the long-term pavement performance. In this study, an enhanced staged extraction method is coupled with two chemical testing techniques to develop a novel approach for evaluating blending efficiency from a qualitative and quantitative perspective: Gel Permeation Chromatography (GPC) and Fourier …

Testing Virtual Machines For Cadrc Server Hosting, Robin Verweij

Computer Science and Software Engineering

No abstract provided.

Design And Construction Of A Portable Gantry Hoist, Sam Hutcheson

BioResource and Agricultural Engineering

This report covers the design of a portable gantry hoist with a custom frame design. The design was based off of the materials that were available and practical for this project to save money. The portable gantry hoist will be rated for a 2 ton capacity. The casters, trolley, and hoist were the only parts purchased.

Thermodynamic Efficiency Evaluation For Distillation Of Ethanol, Joe A. Cavaletto

BioResource and Agricultural Engineering

Energy will always be a consideration when distilling any product. Fog’s End Distillery in Gonzales, CA is a small scale micro distillery for ethanol. For Fog’s End, efficiency is key to staying competitive. In this project the efficiency of energy in vs product out will be calculated. While collecting this data the price/bottle for energy will be determined and used for an assembly cost. To determine the efficiency the fuel usage will be recorded for several distillation trials. The mash contents and product contents will all be measured and calculations will be performed to find the theoretical amount of energy …

Exploring Human-Computer Interaction Through Bluetooth Low Energy Enabled Human Interface Devices, Tyler Durkin

Liberal Arts and Engineering Studies

No abstract provided.

The Effects Of Football Helmet Pressure On The Shock Taken During A Controlled Impact, Sullivan Grosz

Industrial Technology and Packaging

College and NFL football teams are focusing their efforts on protecting players more than ever before. With the recent attention on concussions and the troubling long-term effects of head injuries, more research is needed to find ways to ensure players have the adequate protection. The helmets being used have a hard polycarbonate shell with four inner pads that fit tight to the player’s head. These pads are filled with air.

The purpose of the testing and project is to find an ideal air pressure that helmets need to maintain in order to protect the player to the best of its …

Wind Turbine Controls For Farm And Offshore Operation, Zhongzhou Yang

Theses and Dissertations

Development of advanced control techniques is a critical measure for reducing the cost of energy for wind power generation, in terms of both enhancing energy capture and reducing fatigue load. There are two remarkable trends for wind energy. First, more and more large wind farms are developed in order to reduce the unit-power cost in installation, operation, maintenance and transmission. Second, offshore wind energy has received significant attention when the scarcity of land resource has appeared to be a major bottleneck for next level of wind penetration, especially for Europe and Asia. This dissertation study investigates on several wind turbine …

Seasonal Change In Bacteria Levels And Eluent Comparison For The Enumeration Of E. Coli And Enterococci From Recreational Beach Sand, Kyle Hines

Theses and Dissertations

Research into the causes of bacterial contamination of recreational beaches has been increasing. Many researchers are now looking to enumerate bacteria from beach sands in order to find the connections between the water and sand quality. As the number of these studies increase, there is a need to determine a standard procedure for enumerating bacteria from sand. The eluent that a researcher chooses could impact the results that they obtain due to ionic strength. The first part of this paper compares the E. coli and Enterococci counts of identical sand samples using phosphate buffered saline and distilled water as eluents. …

Steady-State Voltage Security Assessment Using Symmetric Eigenvalue Analysis For Weak Area Identification In Large Power Transmission Network, Yagnaramasubramanian Somayajulu

Theses and Dissertations

The central focus of this thesis is on long-term static voltage stability analysis of large power transmission grid. This thesis work is a product of an attempt to comprehend the numerous researches that has been done over the years on voltage security assessment. Voltage stability is one of the essential components influencing the reliability of a power network. There are several Transmission planning and operation compliance standards pertaining to voltage criterion from NERC and Independent System Operators (ISO) directed toward the utilities to operate their grid within tight voltage limits. This requires the utility to perform comprehensive planning studies of …

Tascked: The Sanity Promoting Task Manager, Jake Tobin

Computer Science and Software Engineering

Personal task managers or various forms of to-do lists are abundant in our modern computing age. With the explosion of mobile computing technology, it is easier than ever to take notes digitally and make the data seemingly instantly available anywhere on the Internet. There is a fairly well defined core set of features in personal task managers available for public consumption, but it seems nothing that is publicly available provides feedback to the user or suggestions based on user history. Tascked is a task management solution, which records user history and solicits user feedback on progress. This allows the system …

Extracting The Structure And Conformations Of Biological Entities From Large Datasets, Ali Dashti

Theses and Dissertations

In biology, structure determines function, which often proceeds via changes in conformation. Efficient means for determining structure exist, but mapping conformations continue to present a serious challenge. Single-particles approaches, such as cryogenic electron microscopy (cryo-EM) and emerging "diffract & destroy" X-ray techniques are, in principle, ideally positioned to overcome these challenges. But the algorithmic ability to extract information from large heterogeneous datasets consisting of "unsorted" snapshots - each emanating from an unknown orientation of an object in an unknown conformation - remains elusive.

It is the objective of this thesis to describe and validate a powerful suite of manifold-based algorithms …

Patient-Oriented Evidence-Based Treatment Decision Support System (Treatquest®) For Lung Cancer, Danqing Hu

Theses and Dissertations

Involving patients in healthcare decisions makes a significant and enduring difference to healthcare outcomes. One challenge for patients is the lack of evidence-based information and tools to support their decision making. Although patients have access to significant information through internet and other sources, it is not personalized for their specific situation. This dissertation attempts to help patients acquire evidence-based information relevant to their own situation, so they can make a more informed decision in co-operation with their physicians. Lung cancer has been selected as a focus for this study because lung cancer presents very complex decision making situation and is …

Shape Memory Alloy Reinforced Self-Healing Metal Matrix Composites, Shobhit Krishna Misra

Theses and Dissertations

A metal matrix composite system incorporating Nickel Titanium (NiTi) Shape Memory Alloy (SMA) as smart reinforcement with self-healing potential for crack closure is investigated. Lead free proof of concept solder matrix-alloys of Sn-Bi with off eutectic compositions were designed, synthesized and characterized. This was aimed at enabling partial melting of the matrix at healing temperature - the temperature at which the reinforced SMA reverts to its original shape, whereby welding the cracks shut. In this composite system, NiTi long fibers (wires) have been incorporated as reinforcements. The reinforcements were etched and flux treated to improve wettability with the solder matrix …

A Dea Model To Optimize Insurance Payment Plans Based On Pacs, Gagan Rajpal

Doctoral Dissertations

Healthcare industry has evolved dramatically over the time. From being a “cottage industry” to an “organized industry” has brought lot of changes. The changes have been both good and bad. Among the problems that have surfaced in past couple of decades, rising healthcare cost has been one of the most significant. The rising healthcare cost has been documented to be a symptom of several factors. Since the inception of healthcare as an organized industry several payment models for providers and hospitals have been adopted. Current healthcare reforms have proposed new payments models to curb the rising cost and provide consumer …

Characterization Techniques And Electrolyte Separator Performance Investigation For All Vanadium Redox Flow Battery, Zhijiang Tang

Doctoral Dissertations

The all-vanadium redox flow battery (VRFB) is an excellent prospect for large scale energy storage in an electricity grid level application. High battery performance has lately been achieved by using a novel cell configuration with advanced materials. However, more work is still required to better understand the reaction kinetics and transport behaviors in the battery to guide battery system optimization and new battery material development. The first part of my work is the characterization of the battery systems with flow-through or flow-by cell configurations. The configuration difference between two cell structures exhibit significantly different polarization behavior. The battery output can …

Pyrolysis Of Acrylonitrile-Butadiene-Styrene (Abs) Under High Heat Flux Conditions, James R. Wilson

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Acrylonitrile-butadiene-styrene (ABS) is a common industrial plastic that is widely used for structural and piping applications. Additionally, within the past decade ABS has become the most popular material used in a type of rapid prototyping known as fused- deposition modeling (FDM). Within the past three years, ABS plastic blends have also been investigated as a potential fuel for hybrid- and solid-propelled rocket systems, exhibiting promising results. Because the use of ABS as a rocket propellant is very recent, a pyrolysis database, describing how ABS will burn, at the temperatures and heating rates experienced by rocket systems does not exist. Previous …

Evaluation Of Alternate Mouthpiece Material Types To Minimize Vibrations And Heat Loss - The Research And Execution Of Prototypes, Kristen Bobuk

Theses, Dissertations and Capstones

This paper is based on the idea of current horn mouthpieces being made solely out of brass with a limited market of stainless steel and titanium with plating being silver or gold. This is an opportunity to explore alternate materials; specifically steel, cast iron and aluminum for the base material and chrome, copper and nickel for plating materials. Readers will learn about metal properties such as hardness, thermal conductivity and specific heat and learn why certain materials are more beneficial than others.

Recovering Bioresources From Integrated Photo-Bioelectrochemical System, Li Xiao

Theses and Dissertations

Compared to traditional wastewater treatment technologies, the electricity generation is one of the most important advantages of bioelectrochemical systems (BES). However, due to its high cost and low energy production, BES technologies are still far away from feasible application. The main purpose of this work was to investigate ways to improve the electricity generation and reduce the cost of BES technologies. We focused on microbial fuel cells (MFCs) and microbial electrolysis cells (MECs) as two representative BES technologies. In order to improve the energy performance of MFCs, an accurate evaluation of the energy is necessary. However, the common evaluation methods …