Engineering Commons^™

Evaluation Of Broiler Litter Heat Production During Windrowing & Nitrogen Based Gas Emission Mitigation Using Biofilter, Min Lei

Graduate Theses and Dissertations

Ammonia emission from animal feeding operations (AFOs) has negative effects on environment and animals' health. Thus measuring and mitigating ammonia emission from AFOs is important for environmental protection. In chapter I, different ammonia measurements were discussed and a mitigation technology- biofilter was represented.

In-house windrowing of built-up litter has been used by broiler producers to reduce pathogen loads and rejuvenate litter for the next flock. When litter is piled up for an extended period during downtime, heat generated by the litter pile can become a substantial heat source due to the metabolism of microorganisms. In chapter II, heat production rates …

Analysis Of Parameter Tuning On Energy Efficiency In Asynchronous Circuits, Justin Thomas Roark

Graduate Theses and Dissertations

Power and energy consumption are the primary concern of the digital integrated circuit (IC) industry. Asynchronous logic, in the past several years, has increased in popularity due to its low power nature. This thesis analyzes a collection of array multipliers with different parameters to compare two asynchronous design paradigms, NULL Convention Logic (NCL) and Multi-Threshold NULL Convention Logic (MTNCL). Several commercially available pieces of software and custom scripts are used to analyze the asynchronous circuits and their components to provide the energy consumption estimation on various parts of each circuit. The analysis of the software results revealed that MTNCL circuits …

Hybrid Nanostructured Textile Bioelectrode For Unobtrusive Health Monitoring, Pratyush Rai

Graduate Theses and Dissertations

Coronary heart disease, cardiovascular diseases and strokes are the leading causes of mortality in United States of America. Timely point-of-care health diagnostics and therapeutics for person suffering from these diseases can save thousands of lives. However, lack of accessible minimally intrusive health monitoring systems makes timely diagnosis difficult and sometimes impossible. To remedy this problem, a textile based nano-bio-sensor was developed and evaluated in this research. The sensor was made of novel array of vertically standing nanostructures that are conductive nano-fibers projecting from a conductive fabric. These sensor electrodes were tested for the quality of electrical contact that they made …

Design And Fabrication Of Inverter And Rectifier Modules For Indirect Matrix Converter Applications, Saikishore Talakokkula

Graduate Theses and Dissertations

In power converter applications, silicon carbide (SiC) power semiconductor devices are preferred over their silicon counterparts due to many advantages such as wide bandgap, high junction temperatures and low on-state resistance. The SiC devices provide reduced conduction and switching losses. Due to the above mentioned advantages the power conversion efficiency of SiC devices is better compared to that of silicon (Si) devices.

This thesis studies the implementation of 1200V/17A Normally-off SiC JFETs for an indirect matrix converter (IMC) application. A discussion on the parasitic inductance optimization is presented based on the electromagnetic simulation results extracted from the Ansoft Q3D extractor. …

Parameterizing Analytical Models To Support An Empirically Based Warehouse Design Methodology, Lisa Thomas

Graduate Theses and Dissertations

Research in the area of warehouse design is characterized by a myriad of analytical models that address one, typically small and isolated, area of the warehouse. These models, although important in gaining insight into one question of warehouse design, are of limited value when one considers the larger question of overall warehouse design. Thus, research in the area of overall warehouse design typically consists of procedure-driven processes based on qualitative factors and not the quantifiable results of analytical models.

In contrast, practitioners have significant empirical data related to how a design alternative performs in an industry, a company, or a …

Structural Properties Of Ferroelectric Lead (Zirconium0.5,Titanium0.5)Oxygen3 Nanotube Array And Electronic Structure Of Lao Delta-Doped Strontium Titanate, Rajendra Prasad Adhikari

Graduate Theses and Dissertations

In this Dissertation we begin with two introductions on: 1) ferroelectricity and related phenomena, and 2) novel properties of Oxide electronics and the generation of two dimensional electron gas. We then give theoretical background of density functional theory (including LDA+U) and pseudopotentials. The first part of research work is about structural, polarization, and dielectric properties of ferroelectric Lead Zirconate Titanate (PZT) solid solution in the form of a nanotube array, embedded in a matrix medium of different ferroelectric strengths. We use the effective Hamiltonian derived from first-principles and finite-temperature Monte Carlo methods to determine the various properties. We revealed different …

Multiscale Study Of Batio3 Nanostructures And Nanocomposites, Lydie Louis Louis

Graduate Theses and Dissertations

Advancements in integrated nanoelectronics will continue to require the use of unique materials or systems of materials with diverse functionalities in increasingly confined spaces.

Hence, research on finite-dimensional systems strive to unearth and expand the knowledge of fundamental physical properties in certain key materials which exhibit numerous concurrent and exploitable functions.

Correspondingly, ferroelectric nanostructures, which particularly display a plethora of complex phenomena, prevalent in countless fields of research, are noteworthy candidates. Presently, however, the assimilation of zero-(0D) and one-dimensional (1D) ferroelectric into micro- or nano-electronics has been lagging, in part due to a lack of applied and fundamental studies but …

Characterization And Quantification Of Monomers, Oligomers, And By-Products From Switchgrass Hemicelluloses During Biomass Pretreatment, Kris Allan Bunnell

Graduate Theses and Dissertations

Production of fuels and chemicals from biomass is contingent upon economical release of carbohydrates from biomass. Carbohydrates can then be used for production of bio-based products using a biochemical conversion process. Pretreatment, the first step of the biochemical conversion process, has been suggested to be the most costly step of the conversion process. Thus, better understanding the behavior of biomass during pretreatment is imperative for an economically viable production of biofuels and chemicals. Elucidating the physicochemical properties of biomass and developing an understanding the depolymerization patterns of biomass during pretreatment will help progress towards this goal.

In this study, July- …

The Legitimation Of Novel Technologies: The Case Of Nanotechnology, Anastasia E. Thyroff

Graduate Theses and Dissertations

Nanotechnology is the control, manipulation, and application of matter on an atomic and molecular level. The technology is complex and confusing to consumers, and its long-term safety and effect on the human body, as well as the environment, are unknown. However, for the past decade, nanotechnology has been used to develop consumer products and food with novel and attractive attributes.

Since nanotechnology is still not well known, it is not legitimized; that is, it has not been deemed safe and accepted by society. However, the market for nanotechnology is in the legitimation process. It will take an entire network of …

Defining Characteristics Of An Integrated Stem Curriculum In K-12 Education, Vinson Robert Carter

Graduate Theses and Dissertations

The purpose of the study was to obtain consensus concerning the defining characteristics of integrated STEM (Science, Technology, Engineering, and Mathematics) curriculum. This study utilized a three round modified Delphi study to solicit recommendations from experts of STEM education in order to: 1) create a set of categorical and defining curricular components needed to develop and implement appropriate integrated STEM curriculum; 2) identify the characteristics that set integrated STEM education curriculum apart from single-discipline curricula; 3) discuss the components necessary to gauge whether an initiative, project, or curriculum should be referred to as integrated STEM education; and 4) examine whether …

Synthesis Of Platinum And Platinum-Copper Branched Nanoparticles For Electrooxidation Of Methanol, Eric Courtland Taylor

Graduate Theses and Dissertations

Platinum and Pt alloys are among the most important heterogeneous catalysts for many organic reactions and electrochemical reactions associated with the fuel cell technologies. How to reduce Pt usage while maintaining the performance of the catalysts becomes a subject for intensive research in materials chemistry. For heterogeneous catalysis, the catalytic reactivity and selectivity are strongly correlated with different crystallographic facets exposed on the surface. The facets with high-index planes whose Miller indices with at one is larger than unity are generally more active than those with low-index planes (e.g., {100}, {111}, and {110}). Tuning the morphology of the nanoparticles to …

High Voltage Direct Current Energy Transmission Using Modular Multilevel Converters, David Alejandro Guzman Pinzon

Graduate Theses and Dissertations

This thesis focus on high voltage direct current (HVdc) energy transmission using modular multilevel converter (MMC) based terminals. It provides a brief comparison between different HVdc technologies, focusing on voltage source converters (HVdc-VSC) with the MMC-based terminal emerging as the topology of choice for ratings less than 1 GW. The controllers for a two-terminal HVdc-link are analyzed and Matlab/Simulink^TM simulation models are presented. The simplified models and full Matlab/Simulink^TM based model are used to select the gains for the MMC controllers. Simulation results carried out on the full model validated the proposed methodologies. A new control technique that …

System Design And Motion Artifact Removal Algorithm Implementation For Ambulatory Women Ecg Measurement System:E-Bra System, Hyeokjun Kwon

Graduate Theses and Dissertations

Cardio Vascular Disease (CVD) leads to sudden cardiac death due to irregular phenomenon of the cardiac signal by the abnormal case of blood vessel and cardiac structure. For last three decades, there is an enhanced interest in research for cardiac diseases.. As a result, the death rate by cardiac disease in men has been falling gradually compared with relatively increasing the death rate for women due to CVD. The main reason for this phenomenon is due to the lack of seriousness to female CVD and different symptoms of female CVD compared with the symptoms of male CVD. Usually, because the …

Algae To Propellants: Biosynthesis Of 1,2-Propanediol From Algal Derived Sugars, Lauren Rachelle Merriman

Graduate Theses and Dissertations

Propylene glycol dinitrate (PGDN) is an important component used in the formulation of energetic materials. A renewable, environmentally-friendly and effective production technique for the production of 1,2-propanediol, an important precursor to PGDN, is desired. While fermentation of 1,2-propanediol has been achieved, it suffers from major limitations such as expensive feed sugars and relatively low yields. It is hypothesized that algae sugars could serve as a feedstock for the microbial synthesis of 1,2-propanediol, thereby reducing production costs and enhancing sustainability.

Algal biomass produced from an Algal Turf Scrubber® has proven to have significant potential as a source of fermentable materials. However, …

Electrical Design Considerations And Packaging Of Power Electronic Modules, Shijie Wang

Graduate Theses and Dissertations

A modern power electronic module can save significant energy usage in the power electronic systems by improving their switching efficiencies. One way to improve the efficiency of the power electronic module is to reduce its parasitic circuit elements. The purpose of this thesis is to investigate the mitigation of parasitic circuit elements in power electronic modules. General methods of mitigating parasitic inductances were analyzed by the Q3D Extractor and verified by the time-domain reflectometry (TDR) measurements. In most cases, the TDR measurement results closely matched those predicted by the Q3D Extractor. These methods were applied to design and analyze a …

Cad Tool Design For Ncl And Mtncl Asynchronous Circuits, Vijay Mani Pillai

Graduate Theses and Dissertations

This thesis presents an implementation of a method developed to readily convert Boolean designs into an ultra-low power asynchronous design methodology called MTNCL, which combines multi-threshold CMOS (MTCMOS) with NULL Convention Logic (NCL) systems. MTNCL provides the leakage power advantages of an all high-Vt implementation with a reasonable speed penalty compared to the all low-Vt implementation, and has negligible area overhead. The proposed tool utilizes industry-standard CAD tools. This research also presents an Automated Gate-Level Pipelining with Bit-Wise Completion (AGLPBW) method to maximize throughput of delay-insensitive full-word pipelined NCL circuits. These methods have been integrated into the Mentor Graphics and …

The Effect Of Platinum In Nafion For Proton Exchange Membrane Fuel Cells, Elliott Korb

Electrical Engineering Undergraduate Honors Theses

Under the growing pressure to veer from fossil fuel use to more environmentally conscious energy options, fuel cells of all kinds are coming to the forefront as viable options to replace part of fossil fuels’ present role. This effort not only includes automobiles, but fuel cells are also emerging as options for emergency generators, modern war ships and submarines, portable charging devices, and space applications. Proton exchange membrane (PEM) fuel cells are likely to dominate the smaller or more domestic applications of fuel cell technology. For the membrane, DuPont’s polymer Nafion was used in varying sizes. Using small testing platforms …

Spice Netlist Generation For Electrical Parasitic Modeling Of Multi-Chip Power Module Designs, Peter Tucker

Electrical Engineering Undergraduate Honors Theses

Multi-Chip Power Module (MCPM) designs are widely used in the area of power electronics to control multiple power semiconductor devices in a single package. The work described in this thesis is part of a larger ongoing project aimed at designing and implementing a computer aided drafting tool to assist in analysis and optimization of MCPM designs. This thesis work adds to the software tool the ability to export an electrical parasitic model of a power module layout into a SPICE format that can be run through an external SPICE circuit simulator. The code was implemented in python using NetworkX graphs …

Analysis Of Aggregate Distribution In Self-Consolidating Concrete, Brendan Ho

Civil Engineering Undergraduate Honors Theses

Concrete consists of several key ingredients: cement, water, and coarse and fine aggregate. Depending on the proportions of these ingredients, the strength and workability of a concrete mix can be affected adversely. Segregation is the separation of aggregate and cement paste, resulting in a lack of homogeneity. Self-consolidating concrete (SCC) does not require traditional consolidation; however, it can be affected by segregation. This project examines different SCC mixtures and establishes ranges of values for slump flow, T20 , Visual Stability Index (VSI), J-ring flow and J-ring flow spread that ensures proper aggregate distribution and therefore reduces the potential of segregation. …

Automated Behavioral Modeling Of Switching Voltage Regulators, Michael Leonard

Electrical Engineering Undergraduate Honors Theses

This work describes the development of a software tool that implements a novel method for automatically generating simulation ready behavioral models for switching circuits with an emphasis on power regulators. The work begins by examining the theory of operation of both linear and switching regulators. Then, the capability of two behavioral modeling languages (Verilog-A and PSPICE ABM) are examined in detail. Next, the languages previously discussed are used to develop and test a model of a commercial regulator (Texas Instruments TPS40305). Finally, the prospect of automating the process is discussed

Internal Curing Using Lightweight Fine Aggregate, Jonathan Kerby

Civil Engineering Undergraduate Honors Theses

Curing refers to the process of maintaining the hydration of the concrete as it hardens, or sets up. Concrete is cured to prevent things such as cracking and shrinkage. Autogenous shrinkage occurs internally in concrete because there isn’t enough water in the concrete for hydration, so the concrete rapidly draws out water to complete the hydration cycle, causing internal drying of concrete. There are two types of curing: external and internal. External curing utilizes water from external sources such as saturated burlap mats, ponding, or fogging. Internal curing supplies water from an internal source inside the concrete, such as saturated …

Mitigating Shrinkage Cracking Of Concrete In Bridge Decks Through Internal Curing, Daniel Robert Goad

Graduate Theses and Dissertations

As the need for durable, long lasting infrastructure increases, new methods and techniques are being explored to prolong the service life of roads and bridges. One method to reduce shrinkage and early age cracking in concrete is internal curing. Internal curing supplies water to concrete, using pre-wetted lightweight aggregate (LWA), as needed throughout the process of hydration to reduce self desiccation, which leads to cracking. This research project analyzed two types of coarse LWA, expanded clay and expanded shale. The mixtures were developed specifically for use in bridge decks and adhered to specifications of the Arkansas State Highway and Transportation …

Variability In The Hydraulic Conductivity Of A Test Pad Liner System Using Different Testing Techniques, Matthew Jonathan Nanak

Graduate Theses and Dissertations

Historic methods (the time lag approach, the velocity approach, and the Z-t approach), utilized to reduce two stage borehole test data, were evaluated. Two of the historic methods provided viable results and were used for this research project. Additionally, these two methods are recommended for reducing two stage borehole test data in the future.

Flexible wall permeameter and soil index laboratory testing were conducted on the soil used to construct three environmentally controlled compacted clay liners (test pads) to develop a zone of acceptance (placement window). Using the results from the laboratory testing, two acceptance criterions were evaluated, while one …

Creep, Fatigue And Creep-Fatigue Interactions In Modified 9% Cr - 1% Mo (P91) Steels, Valliappa Kalyanasundaram

Graduate Theses and Dissertations

Grade P91 steel, from the class of advanced high-chrome ferritic steels, is one of the preferred materials for many elevated temperature structural components. Creep-fatigue (C-F) interactions, along with oxidation, can accelerate the kinetics of damage accumulation and consequently reduce such components' life. Hence, reliable C-F test data is required for meticulous consideration of C-F interactions and oxidation, which in turn is vital for sound design practices. It is also imperative to develop analytical constitutive models that can simulate and predict material response under various long-term in-service conditions using experimental data from short-term laboratory experiments. Consequently, the major objectives of the …

Return To Traffic Of Full Depth Reclamation Pavements, Robert Benjamin Hill

Graduate Theses and Dissertations

Full-Depth Reclamation (FDR) is a cost-effective rehabilitation treatment for deteriorated pavements. However, when using asphalt emulsion based rehabilitation techniques one of the most challenging aspects of FDR is determining when traffic can be returned to the rehabilitated pavement surface. Since asphalt emulsion mixtures need ample time for curing, they cannot be sealed with a surface layer until the water has evaporated from the rehabilitated layer. It is often not possible to keep the road closed until all of the water has evaporated and the surface layer is placed, therefore, at some point the traffic needs to be returned to the …

In Vivo Efficacy Of Chitosan/Interleukin-12 In Controlling Lung Metastasis In 4t1 Breast Cancer Model, Jimmy Vo

Biomedical Engineering Undergraduate Honors Theses

Cancer immunotherapy has emerged as a leading front in cancer treatment. In contrast to other treatment methods such as radiation and surgery, immunotherapy trains the patient's body to recognize and eliminate tumors, thus preventing reoccurrence of secondary tumors. IL-12 has been shown to display a potent anti-tumor immune response in mice; however, when clinical trials were conducted, it was shown to be toxic and in some cases fatal when administered systemically.1,2 Because of this, local delivery of IL-12 is under investigation. Our lab has shown that when paired with the polymer chitosan, local, intratumoral (i.t.) injections of IL-12 are retained …

Novel Method For Sequential Batch Recovery Of Biomass From A Helical Photobioreactor, Matthew Hurst

Chemical Engineering Undergraduate Honors Theses

This study developed and evaluated a novel method to recover the microalgae species Arthrospira platensis from a closed helical photo bioreactor system. A recovery apparatus was designed and shown to increase recovery by 40% via periodic online recovery runs during exponential growth phase of biomass. Considerations for the apparatus design included the low shear tolerance of the algae and the necessity for a closed system in order to monitor CO2 consumption. The recovery method draws on methods used for large scale recovery as reported in literature by Vonshak and Shimmatsu [1], [2]. This work seeks to improve reactor biomass yield …

Protein Isolation Using Peptoid Based Affinity Chromatography, Megan Dunn

Chemical Engineering Undergraduate Honors Theses

Protein purification is essential for advancements in biotechnology. There are several different methods employed in purifying a particular protein from a complex sample such as a cell lysate. These methods take advantage of differences in the size, charge or binding affinity of the protein. One such method is affinity chromatography which utilizes the binding affinity of a protein toward a certain ligand to purify a protein. This is usually used as a final step to extract the desired protein after the mixture has undergone other purification steps to remove unwanted materials. The goal of this project was to develop a …

Characterization Of An Affitoid Variable Region To Be Used For Mdm-2 Detection In Elisa Microarray, Graham Reinhard

Chemical Engineering Undergraduate Honors Theses

Sandwich enzyme-linked immunosorbent assay (ELISA) microarray using peptoid-based affinity reagents, referred to as affitoids, is potentially a very powerful tool for the early detection of cancer and other complex diseases. Current detection methods for cancer are inadequate because most are imaging techniques and require that the cancer has progressed far enough for growths to be visible, which is often far too late for treatment to be effective. One possible way to overcome this issue is to use a biological detection technique that is able to detect proteins that are secreted specifically by cancerous cells (referred to as biomarkers). These biomarkers …

The Effect Of The Local Refractive Index On The Spectral Properties Of Gold Nanoparticle Arrays, Justin Norman

Chemical Engineering Undergraduate Honors Theses

Gold nanoparticle arrays exhibit extraordinary spectral properties useful to a wide variety of applications including biomolecular sensing, alternative energy, and informatics. The spectral properties of these arrays depend on the array geometry (particle size and spacing) and the surrounding environment (refractive index). In this thesis, a thorough map of the parameter space describing the spectral properties of square, gold nanoparticle arrays is developed in conjunction with a fundamental theoretical description of the phenomena that govern these properties.