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 Department: Department of Engineering Technology
Design and validation of an automated multiunit composting system.

Design and validation of an automated multiunit composting system.

Date: December 2009
Creator: Pickens, Mark Everett
Description: This thesis covers the design of an automated multiunit composting system (AMUCS) that was constructed to meet the experimental apparatus requirements of the ASTM D5338 standard. The design of the AMUCS is discussed in full detail and validated with two experiments. The first experiment was used to validate the operation of the AMUCS with a 15 day experiment. During this experiment visual observations were made to visually observe degradation. Thermal properties and stability tests were performed to quantify the effects of degradation on the polymer samples, and the carbon metabolized from the degradation of samples was measured. The second experiment used the AMUCS to determine the effect of synthetic clay nanofiller on the aerobic biodegradability behavior of poly (3-hydroxybutyrate-co-3-hydroxyvalerate).
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Design of Power Amplifier Test Signals with a User-Defined Multisine

Design of Power Amplifier Test Signals with a User-Defined Multisine

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Date: May 2004
Creator: Nagarajan, Preeti
Description: Cellular radio communication involves wireless transmission and reception of signals at radio frequencies (RF). Base stations house equipment critical to the transmission and reception of signals. Power amplifier (PA) is a crucial element in base station assembly. PAs are expensive, take up space and dissipate heat. Of all the elements in the base station, it is difficult to design and operate a power amplifier. New designs of power amplifiers are constantly tested. One of the most important components required to perform this test successfully is a circuit simulator model of an entire communication system that generates a standard test signal. Standard test signals 524,288 data points in length require 1080 hours to complete one test of a PA model. In order to reduce the time taken to complete one test, a 'simulated test signal,' was generated. The objective of this study is to develop an algorithm to generate this 'simulated' test signal such that its characteristics match that of the 'standard' test signal.
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Determination of the shelf life of aluminum electrolytic capacitors.

Determination of the shelf life of aluminum electrolytic capacitors.

Date: May 2002
Creator: Wynne, Edward McFaddin
Description: The aluminum electrolytic capacitor is used extensively in the electric utility industry. A factor limiting the storage of spare capacitors is the integrity of the aluminum oxide dielectric, which over time breaks down contributing to a shelf life currently estimated at one nuclear power electric generating station to be approximately five years. This project examined the electrical characteristics of naturally aged capacitors of several different styles to determine if design parameters were still within limits. Additionally, the effectiveness of a technique known as “Reforming” was examined to determine its impact on those characteristics.
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Development of a coaxiality indicator

Development of a coaxiality indicator

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Date: December 1999
Creator: Arendsee, Wayne C.
Description: The geometric dimensioning and tolerancing concept of coaxiality is often required by design engineers for balance of rotating parts and precision mating parts. In current practice, it is difficult for manufacturers to measure coaxiality quickly and inexpensively. This study examines feasibility of a manually-operated, mechanical device combined with formulae to indicate coaxiality of a test specimen. The author designs, fabricates, and tests the system for measuring coaxiality of holes machined in a steel test piece. Gage Repeatability and Reproducibility (gage R&R) and univariate analysis of variance is performed in accordance with Measurement System Analysis published by AIAG. Results indicate significant design flaws exist in the current configuration of the device; observed values vary greatly with operator technique. Suggestions for device improvements conclude the research.
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Development of a Hybrid Molecular Ultraviolet Photodetector based on Guanosine Derivatives

Development of a Hybrid Molecular Ultraviolet Photodetector based on Guanosine Derivatives

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Date: December 2005
Creator: Liddar, Harsheetal
Description: Modern studies on charge transfer reaction and conductivity measurements of DNA have shown that the electrical behavior of DNA ranges from that of an insulator to that of a wide bandgap semiconductor. Based on this property of DNA, a metal-semiconductor-metal photodetector is fabricated using a self-assembled layer of deoxyguanosine derivative (DNA base) deposited between gold electrodes. The electrodes are lithographically designed on a GaN substrate separated by a distance L (50nm < L < 100nm). This work examines the electrical and optical properties of such wide-bandgap semiconductor based biomaterial systems for their potential application as photodetectors in the UV region wherein most of the biological agents emit. The objective of this study was to develop a biomolecular electronic device and design an experimental setup for electrical and optical characterization of a novel hybrid molecular optoelectronic material system. AFM results proved the usage of Ga-Polar substrate in conjugation with DG molecules to be used as a potential electronic based sensor. A two-terminal nanoscale biomolectronic diode has been fabricated showing efficient rectification ratio. A nanoscale integrated ultraviolet photodetector (of dimensions less than 100 nm) has been fabricated with a cut-off wavelength at ~ 320 nm.
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Direct Strength Method for Web Crippling of Cold-formed Steel C-sections

Direct Strength Method for Web Crippling of Cold-formed Steel C-sections

Date: May 2013
Creator: Seelam, Praveen Kumar Reddy
Description: Web crippling is a form of localized buckling that occurs at points of transverse concentrated loading or supports of thin-walled structural members. The theoretical computation of web crippling strength is quite complex as it involves a large number of factors such as initial imperfections, local yielding at load application and instability of web. The existing design provision in North American specification for cold-formed steel C-sections (AISI S100, 2007) to calculate the web-crippling strength is based on the experimental investigation. The objective of this research is to extend the direct strength method to the web crippling strength of cold-formed steel C-sections. ABAQUS is used as a main tool to apply finite element analysis and is used to do the elastic buckling analysis. The work was carried out on C-sections under interior two flange (ITF) loading, end two flange (ETF) loading cases. Total of 128 (58 ITF, 70 ETF) sections were analyzed. Sections with various heights (3.5 in.to 6 in.) and various lengths (21 in. to 36 in.) were considered. Data is collected from the tests conducted in laboratory and the data from the previous researches is used, to extend the direct strength method to cold formed steel sections. Proposing a new ...
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Drive Level Dependence of Advanced Piezoelectric Resonators

Drive Level Dependence of Advanced Piezoelectric Resonators

Date: August 2012
Creator: Xie, Yuan
Description: Resonators are one of the most important parts of electronic products. They provide a stable reference frequency to ensure the operation of these products. Recently, the electronic products have the trend of miniaturization, which rendered the size reduction of the resonators as well [1]. Better design of the resonators relies on a better understanding of the crystals' nonlinear behavior [2]. The nonlinearities affect the quality factor and acoustic behavior of MEMS (Micro-Electro-Mechanical-System) and nano-structured resonators and filters [3]. Among these nonlinear effects, Drivel Level Dependence (DLD), which describes the instability of the resonator frequency due to voltage level and/or power density, is an urgent problem for miniaturized resonators [2]. Langasite and GaPO4 are new promising piezoelectric material. Resonators made from these new materials have superior performance such as good frequency-temperature characteristics, and low acoustic loss [2]. In this thesis, experimental measurements of drive level dependence of langasite resonators with different configurations (plano-plano, single bevel, and double bevel) are reported. The drive level dependence of GaPO4 resonators are reported as well for the purpose of comparison. The results show that the resonator configuration affects the DLD of the langasite resonator. Experiments for DLD at elevated temperature are also performed, and it ...
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Effect of Amines as Corrosion Inhibitors for a Low Carbon Steel in Power Industry

Effect of Amines as Corrosion Inhibitors for a Low Carbon Steel in Power Industry

Date: December 2004
Creator: Díaz, Jorge G.
Description: Commonly used amines in power industry, including morpholine, DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), and DMA (dimethylallylamine) were evaluated for their effect on AISI 1018 steel at 250oF. Samples were exposed to an autoclave containing amine added aqueous solution at pH of 9.5 for 1, 2, 4, 6, 8, and 12 hours. Morphology studies were carried using scanning electron microscope (SEM), phase analysis was done utilizing Fourier transform infrared spectroscopy (FTIR), and weight loss was performed to assess kinetics of oxidation. Control samples showed the highest metal dissolution rate. DBU showed the best performance in metal protection and SEM indicated the presence of a free-crack layer formed by fine particles in that set. FTIR showed that DBU apparently favored the formation of magnetite. It is believed that fine particles impede intrusion of aggressive ions into the metal surface by forming a barrier layer. FTIR demonstrated that DMA formed more oxyhydroxides, whereas morpholine presented magnetite to hematite transformation as early as 2 hours. SEM revealed that control and DMA produced acicular particles characteristic of oxyhydroxides while morpholine and DBU presented more equiaxed particles.
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Effect of engineered surfaces on valve performance.

Effect of engineered surfaces on valve performance.

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Date: December 2000
Creator: Pope, Larry G.
Description: Performance of air operated valves is a major maintenance concern in process industries. Anecdotal information indicates that reliability of some high maintenance valves has been improved by using an ion deposition process to achieve engineered surfaces on selected components. This project compared friction for various surface treatments of selected valve components. Results indicate valve performance may be slightly more consistent when an engineered surface is applied in the valve packing area; however surface treatment in this area does not appear to have a dominant affect on reducing valve friction. Results indicate a linear relation between stem friction and torque applied to packing flange nuts, and even after a valve is in service, controlled packing adjustments can be made without significantly changing valve stroke time.
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Effect of Polyphosphoric Acid on Aging Characteristics of PG 64-22 Asphalt Binder

Effect of Polyphosphoric Acid on Aging Characteristics of PG 64-22 Asphalt Binder

Date: December 2010
Creator: Ramasamy, Naresh Baboo
Description: This research presents the results on an experimental investigation to identify the effect of polyphosphoric acid (PPA) on aging characteristics of an asphalt binder. Addition of PPA to asphalt binders is said to improve performance of flexible pavements. Asphalt binder PG 64-22 in modified and unmodified conditions was subjected to aging in the laboratory using a regular oven and also simulated short term aging using rolling thin film oven (RTFO) test. Aging experiments were conducted to analyze the extent of oxidation in terms of changes in molecular structure of the asphalt binder. These changes were appraised using Fourier transform infrared (FTIR) spectroscopy, dynamic shear rheometer (DSR), and epifluorescence microscopy tests. FTIR was used to determine the changes in major bands with addition of PPA. Stiffness and viscoelastic behaviors of asphalts were determined from the DSR test. The stiffness is measured by calculating the shear modulus, G* and the viscoelastic behavior is measured by calculating the phase angle, sin &#948;. Epifluorescence microscopy is a tool used to study properties of organic or inorganic substances. The morphological characteristics of PPA modified asphalt samples were observed through epifluorescence microscopy. Epifluorescence microscopy reveals the polymer phase distribution in the asphalt binders. Results of this ...
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