Engineering Commons^™

Modification And Evaluation Of Continuous Roll Prediction Model For Front Drive Mowers, Xinyan Wang

Doctoral Dissertations

The recently approved ASAE Standard S547 “Tip-Over Protective Structure (TOPS) for Front Wheel Drive Turf and Landscape Equipment” addressed a continuous roll prediction model for Roll-Over Protective Structure (ROPS) design. The existing model described in this Standard did not take into account the influence of the mower deck on the rollover behavior. In order to evaluate the accuracy of the original model, according to the ASAE S547 requirement, a 4.05 meters long and 3.42 meters wide slope of 35 degrees was constructed at the University of Tennessee. Lateral upset tests for Deere F925 front drive mower with regular and inverted …

Differential-Algebraic Approach To Speed And Parameter Estimation Of The Induction Motor, Mengwei Li

Doctoral Dissertations

This thesis considers a differential-algebraic approach to estimating the speed and rotor time constant of an induction motor using only the measured terminal voltages and currents. It is shown that the induction motor speed satisfies both a second-order and a third-order polynomial equation whose coefficients depend the stator voltages, stator currents, and their derivatives. Further, it is shown that as long as the stator electrical frequency is nonzero, the speed is uniquely determined by these polynomials. The speed so determined is then used to stabilize a dynamic (Luenberger type) observer to obtain a smoothed speed estimate. With full knowledge of …

Thermal And X-Ray Analysis On The Origin Of Double Melting Phenomena Of Poly(L-Lactic Acid) Films, Xiaoyun Ling

Doctoral Dissertations

Thermal analysis is one of the most commonly used techniques to characterize the structure and properties of semicrystalline polymers. Unfortunately, the interpretation of thermal events is not always straightforward, but can be quite complicated. However, the complexity involved is often overlooked, leading to erroneous or, at least, questionable results and interpretations. In the present study we carry out an extensive investigation of the thermal behavior of poly(L-lactic acid), PLLA, films prepared under a wide range of crystallization conditions, including isothermal and non-isothermal crystallization from both the glassy state and the melt. The primary techniques used were differential scanning calorimetry (DSC), …

High-Temperature Low-Cycle-Fatigue And Crack-Growth Behaviors Of Three Superalloys: Hastelloy ® X, Haynes ® 230, And Haynes ® 188, Yulin Lu

Doctoral Dissertations

Extensive smooth-bar low-cycle-fatigue (LCF) and fatigue crack growth (FCG) experiments on three solid-solution-strengthened superalloys HASTELLOY X, HAYNES 230, and HAYNES 188 have been conducted at 816 and 927 C. Limited tests were run at 649 C, 871 C, and 982 C to study the temperature effect. The LCF tests were performed under a total-strain-range-control mode at Solar Turbines Inc., Metcut Research Inc., and The University of Tennessee (UT). The FCG tests were done under both the constant-load-range and constant-stress-intensity-factor-range modes at Westmoreland Testing Inc. and UT. Various hold times were imposed at the maximum strain or load in both the …

Isolation And Thermodynamic Characterization Of Aminoglycoside Nucleotidyltransferase (2″)-Ia, Roger Edward Wright

Doctoral Dissertations

Aminoglycoside nucleotidyltransferase(2″)-Ia is one of the most important aminoglycoside-modifying enzymes. Because of the difficulties in isolating this enzyme with a high level of purity, very little work has been reported for this enzyme. A procedure for obtaining this enzyme with a purity level of greater than 95% from inclusion bodies was developed. The optimal conditions for isolating ANT(2″) were solubilizing the inclusion bodies in 8 M urea followed by direct dilution of the enzyme into 0.1 M Tris-HCl pH 8.5, 0.2 M KCl, 0.4 ML-arginine and 5 mM reduced glutathione at 4°C. The determination of an effective method of obtaining …

A Proposed Framework For Simultaneous Optimization Of Evacuation Traffic Distribution And Assignment, Fang Yuan

Doctoral Dissertations

In the conventional evacuation planning process, evacuees are assigned to fixed destinations based mainly on the criterion of geographical proximity. However, such pre-specified destinations (OD table) almost always lead to sub-optimal evacuation efficiencies due to uncertain road conditions such as congestion, road blockage, and other hazards associated with the emergency. By relaxing the constraint of assigning evacuees to pre-specified destinations, a one-destination evacuation (ODE) concept has the potential of greatly improving the evacuation efficiency. A framework for simultaneous optimization of evacuation traffic distribution and assignment is therefore proposed in this study. Based on the concept of ODE, the optimal destination …

Analysis Of Vehicle Use Patterns During Military Field Exercises To Identify Potential Roads, Chunxia Wu

Doctoral Dissertations

Military training is an intensive land use and can cause negative environmental effects. Many studies conducted under Integrated Training Area Management (ITAM) for quantifying the impact resulted from the military training exercise found that off-road vehicular activities during training exercises cause the major impact to the training land. Vehicle land use patterns at a certain location affect the impact severity: concentrated and repeated traffic create more serious damage to the land compared to the dispersed offroad vehicle movements. Those areas heavily disturbed by off-road traffic may require a longer period of time or special treatments for the land to return …

Evaluation Of Heavy-Duty Diesel Vehicle Emissions During Cold-Start And Steady-State Idling Conditions And Reduction Of Emissions From A Truck-Stop Electrification Program, James A. Calcagno

Doctoral Dissertations

Cold-start and extended-idling emissions of carbon monoxide (CO), oxides of nitrogen (NOx) and particulate matter (PM) were measured from 24, class-8B, heavy-duty diesel vehicles (HDDV8B) using portable emission monitoring equipment. The ratio of nitrogen dioxide (NO₂) to NOx and the ratio of PM_2.5 to total PM were reported. Truck model years ranged from 1992 to 2004. All vehicles were tested in the field during summer and fall months under ambient environmental conditions at low (600-800 rpm) and high (1000 rpm) engine idling speeds with the truck cab air-conditioner operating at “on” and “off” modes. Sampling data thus …

Health Risk Assessment Posed By The Mobile Source Air Toxics On An Urban To Regional Area, Luis Alonso Díaz Robles

Doctoral Dissertations

Air toxics are important health concern. The purpose of this research was to develop a protocol to predict exposure concentrations of air toxics and inhalation cancer and noncancer risk that come from different gasoline and diesel-fueled sources. The protocol was developed by linking the U.S. EPA’s Models-3/CMAQ model as the exposure model and toxicological and epidemiological evidence functions. The NEI version 3 for the year 1999 was used in this analysis for point, area, and non-road sources, whereas NMIM was used to create the on-road emissions. The year 2003 was used for meteorological data and as reference to compare the …

Liquid Crystals Confined In Nanoporous Silica, Yang Gao

Doctoral Dissertations

Confinement has a nontrivial effect on a condensed matter system due to the finite size effect, the surface effect and the induced disorder. Different techniques such as calorimetric measurement, dielectric spectroscopy, dynamic light scattering, X-ray scattering and quasi-elastic neutron scattering have been widely used to study this important topic. Confined liquid crystals (LCs) have attracted great attention in particular because they are a soft system and their physical properties are more easily affected by the geometrical confinement (entropic) effect and the surface interaction (energetic) effect. In this paper, we study the phase transitions and dynamic behavior of LCs, 5CB and …

Adaptive Nonlinear Optimization Methodology For Installed Capacity Decisions In Distributed Energy/Cooling Heat And Power Applications., Carl Randolph Hudson

Doctoral Dissertations

Evaluation of potential cooling, heating and power (CHP) applications requires an assessment of the operations and economics of a particular system in meeting the electric and thermal demands of a specific end-use facility. Given the electrical and thermal load behavior of a facility, the tariff structure for grid-supplied electricity, the price of primary fuel (e.g., natural gas), the operating strategy and characteristics of the CHP system, and an assumed set of installed CHP system capacities (e.g., installed capacity of prime mover and absorption chiller), one can determine the cost of such a system as compared to reliance solely on traditional, …

The Rrnat/Rdna Ratio As A Measure Of Nitrite Oxidizing Activity, Shawn A. Hawkins

Doctoral Dissertations

A bench scale nitrification reactor (BSNR) containing nitrite oxidizing bacteria (NOB) of the genus Nitrobacter (» 1 × 10¹⁰/L; 5 - 22% of bacteria) was used to assess the ribosomal RNA transcript (rRNAt) to ribosomal RNA gene (rDNA) ratio as an in-situ nitrite oxidizing activity metric. A quantitative PCR detection system was developed that amplified a 143 base pair sequence within the Nitrobacter spp. 16S - 23S intergenenic spacer region. The resulting real-time PCR (rDNA) and real-time RT-PCR (rRNAt) assays were specific, accurate, and sensitive, requiring three replicate nucleic acid extracts to reliably detect a true 2-fold concentration …

The Effect Of Ultrasonic Vibration On The Solidification Of Light Alloys, Xiaogang Jian

Doctoral Dissertations

This exposition presents the novel thermodynamical and microstructural modification to light alloys, such as aluminum alloys and magnesium alloys, by ultrasonic vibrations during their solidification processes. Ultrasonic vibration has proven to be effective in controlling columnar dendritic structure, reducing the size of equiaxed grains, and under some conditions, producing globular non-dendritic grains. Despite this, the solidification process under the effect of ultrasonic vibration was not clear. Not only was there no such research on how ultrasonic vibration affected its solidification thermodynamically, but also its effects on the as-cast microstructure, including the primary fcc phase, the eutectics, and the secondary phases, …

Experimental, Theoretical, And Device Application Development Of Nanoscale Focused Electron-Beam-Induced Deposition, Steven Jeffrey Randolph

Doctoral Dissertations

To elucidate the effects of beam heating in electron beam-induced deposition (EBID), a Monte-Carlo electron-solid interaction model has been employed to calculate the energy deposition profiles in bulk and nanostructured SiO₂. Using these profiles, a finite element model was used to predict the nanostructure tip temperatures for standard experimental EBID conditions. Depending on the beam energy, beam current, and nanostructure geometry, the heat generated can be substantial. This heat source can subsequently limit the EBID growth by thermally reducing the mean stay time of the precursor gas. Temperature dependent EBID growth experiments qualitatively verified the results of the …

Suppliers Evaluation And Selection: A Comprehensive Model To Minimize The Risk Associated With Quality And Delivery, Ammar Mohamed Aamer

Doctoral Dissertations

This research focuses on one of the main steps in outsourcing, supplier
evaluation and selection. The main contributions of this research were twofold.
First, best practices in the supplier’s value stream were identified that directly or
indirectly impact a supplier’s quality and delivery. Second, a comprehensive
supplier evaluation and selection model was developed based on the value
stream concept to minimize the risk associated with two very critical supplierselection factors, quality and on-time delivery.

A survey was conducted to identify best practices. The outcome of the survey
was used to develop a computer based supplier evaluation model, which could
be …

Manufacturing System And Supply Chain Analyses Related To Product Complexity And Sequenced Parts Delivery, Hui Sun

Doctoral Dissertations

Mixed model assembly has been widely used in many industries. It is applied in order to effectively deal with increasing product complexity. Sequencing and resequencing on a mixed-model assembly line is also complicated by high product complexity. To improve the performance of a mixed-model assembly system and the supply chain, one can develop efficient sequencing rules to address sequencing problems, and manage product complexity to reduce its negative impact on the production system. This research addresses aspects of sequence alteration and restoration on a mixed-model assembly line for the purpose of improving the performance of a manufacturing system and its …

A Methodology For Solving The Equations Arising In Nonlinear Parameter Identification Problems: Application To Induction Machines, Kaiyu Wang

Doctoral Dissertations

This dissertation presents a method that can be used to identify the parameters of a class of systems whose regressor models are nonlinear in the parameters. The technique is based on classical elimination theory, and it guarantees that the solution for the parameters which minimize a least-squares criterion can be found in a finite number of steps. The proposed methodology begins with an input-output linear overparameterized model whose parameters are rationally related. After making appropriate substitutions that account for the overparameterization, the problem is transformed into a nonlinear least-squares problem that is not overparameterized. The extrema equations are computed, and …

Automated Analysis Of Fluorescent Microscopic Images To Identify Protein-Protein Interactions, Sankar Venkataraman

Masters Theses

The identification and confirmation of protein interactions significantly challenges the field of systems biology and related bio-computational efforts. The identification of protein-protein interactions along with their spatial and temporal localization is useful for assigning functional information to proteins. Fluorescence microscopy is an ideal method for assessing protein localization and interactions as a number of techniques and reagents have been described. Historically, data sets obtained from fluorescence microscopy have been analyzed manually, a process that is both time consuming and tedious. The development of an automated system that can measure the location and dynamics of interacting proteins inside a live cell …

Design Of A Novel Reluctance Motor For Industrial Applications, Weston Clute Johnson

Masters Theses

A novel reluctance motor topology, termed the Johnson-Currie Reluctance Motor (JCRM), has been developed and described in this thesis. The JCRM topology and analysis is based upon the traditional switched reluctance motor (SRM) topology although there are significant modifications.

The flux path of the JCRM topology is such that it passes through the rotor and stator in three-dimensions. This topology with three dimensional flux paths allows for the removal of discrete stator windings giving rise to vastly superior maintance to the traditional SRM and arguably to most electric motors. In addition, the usage of three-dimensions for flux paths gives rise …

Bench Scale Evaluation Of Dense Ceramic Membranes For Production Of High Purity Hydrogen From Gasification, Binay Kumar Singh

Masters Theses

Gasification for production of hydrogen and other useful gases, has achieved increasing importance in recent years. The reactions involved in gasification are favored at high temperatures and they are also limited by thermodynamic equilibrium. The development of membranes which can separate these gases under gasifier exit gas condition will significantly improve process efficiency and economics and simultaneously provide for the recovery of valuable gases. The availability of a membrane with adequate hydrogen selectivity and good thermal and mechanical stability is the key for the successful application of membrane technology in hydrogen production and separation. This work introduces a special method …

Managing The Remaining Service Life Of The T-34c Aircraft, John Howard Rousseau

Masters Theses

The T-34C Airplane has been the primary trainer aircraft of the United States Navy for more than twenty-five years and is reaching the end of its service life. The Navy has delayed the procurement of the replacement T-6A Texan II aircraft for five years, yet does not expect the future training requirements to diminish. This delay in T-6A procurement along with recent observed increases in primary trainer aircraft usage have resulted in the need for the Navy to pay considerable attention to the remaining service life of the T-34C aircraft.

This thesis will discuss the methodology used to determine future …

A Dynamic Ampacity Model For The Testing Of Advanced Conductors, Matthew Benjamin Sooter

Masters Theses

Advanced Conductors are an intriguing new technology that promises to help the utility industry increase the transmission capacity available in the United States. Manufacturers of advanced conductors promise double the current carrying capacity of normal Aluminum Clad Steel Reinforced conductor through a combination of increased thermal limits and decreased thermal elongation.

This thesis will outline a control developed for the Power Line Conductor Accelerated Test Facility at Oak Ridge National Laboratory. This custom facility is designed for the testing and rapid aging of advanced overhead conductors as part of a U.S. Department of Energy initiative to assist the development and …

Comparison Of Microscopic Modalities For The 3d Model Reconstruction Of Nanodevices, Christopher Robert Kammerud

Masters Theses

As manufacturing capabilities push nanotechnology to smaller and smaller scales, novel inspection schemes must be developed to ensure product quality. The objective of our research was to implement, refine, and compare 3D reconstruction algorithms that could aid manufacturers in their ability to visualize and inspect nanodevices. Data was collected from three different microscopes: the atomic force microscope (AFM), the scanning electron microscope (SEM), and the laser scanning confocal microscope (LSCM). For each of these microscopes, a specific algorithm was implemented to generate 3D models from the raw microscope data. Scans from the AFM microscope give range information similar to laser …

A Statistical Based Model To Manage Perishable Goods Within A Cold Supply Chain, Amanda Rhiana Hicks

Masters Theses

"Cold chain" management, the management of a temperature sensitive supply chain, has its own particular set of logistical challenges and issues when compared to a non-temperature sensitive supply chain. Current supply chain management techniques and tools that are utilized today in industry do not take this unique set of challenges into account. This thesis will focus on how using a model that has been built upon the theories of statistical process control techniques that does take the challenges into account, when monitoring and evaluating in-transit shipment of perishable goods throughout the cold supply chain, can assist in continuously improving the …

Evaluation Of Engineering Plastic For Rollover Protective Structure Mounting, Robert Stephen Comer

Masters Theses

The agricultural industry has one of the highest fatality rates of any industry in the U. S. This death rate is largely due to deaths caused by roll over accidents while on agricultural vehicles. The addition of a Rollover Protective Structure (ROPS) has aided in lowering these high fatality rates on full-size tractors. Studies have shown that death rates have been reduced by as much as 98% with the addition of rollover protective structures. However, a large number of older tractors still do not utilize a ROPS. This is due to the difficulty of designing and creating a mounting structure. …

A Comparison Of The Sensor Brick Concept As A Modular System Architecture To The Realtime Control System As The Operational Architecture, James Robert Wilson

Masters Theses

This thesis describes the application of modular design into an intelligent mobile robotic system. The Sensor Brick System, a mobile robotic system infused with artificial intelligence, is derived through the concept and application of modular design. Modular design drives the system’s characterization by defining, identifying and selecting the essential composite of sub-systems that form the system architecture. The principles of modular design designate grouping the technologies into modules that facilitate maintenance of the system components and allow the rapid integration of future technological developments. Developing the operational control of the system requires an examination and comprehension of the theories of …

An Experimental Study Of Axisymmetric Cavity Oscillations In Low Speed Incompressible Flow, Jeremy David Brice Smith

Masters Theses

This study is the latest increment of an ongoing research effort at the University of Tennessee Space Institute with the goal of accomplishing a greater understanding of cavity instabilities and or making use of the instabilities to amplify their effects on the flows. An experimental procedure was designed to examine the unsteady pressure pulses that occur when an incompressible fluid (water) flows through an axisymmetric cavity. The length to depth ratios (L/D) examined ranged from about 0.69 to about 6.2, and the average flow Reynolds numbers ranged from 0 to 1.2 million.

Results show that large amplitude oscillations are generated …

Approaches For Autonomous Vehicles In Civil Airspace: Giving Sight To The Blind, Nicholas Scott Hardman

Masters Theses

The growing prevalence of unmanned aerial vehicles (UAVs) brings great potential for public benefit, but in order to fly in civil airspace UAVs must avoid traffic without the benefit of an onboard human. Developing this capability presents many system integration challenges.

This report examines the integration of automated detect, see, and avoid (DSA) systems on aircraft. For context, the need for UAV operations is reviewed. The report then examines how DSA fits into the entire framework for aviation safety. The research, test results, and conclusions that follow provide the necessary information to decide:

• how to test and evaluate new …

Experimental Aerodynamic Analysis Of A Wing-Flap System With Delta Vortex Generators, Charles Roy Mcconnell

Masters Theses

The principle idea upon which the use of vortex generators (VGs) is based has been to control flow separation. The characteristic of VGs has been used to improve lift and alter the stall characteristics of aircraft and has been a relatively common practice for many years. Due to the seemingly limitless range of VG geometries and arrangements, which are largely dependant upon the desired aerodynamic performance, there has been a broad investigation into VG application.

The purpose of this experimental investigation has been to collect data to be used to establish the effects of various delta shaped vortex generators (delta-VGs) …

Optimization Of Dsss Receivers Using Hardware-In-The-Loop Simulations, Balbir Kaur Dhillon

Masters Theses

Over the years, there has been significant interest in defining a hardware abstraction layer to facilitate code reuse in software defined radio (SDR) applications. Designers are looking for a way to enable application software to specify a waveform, configure the platform, and control digital signal processing (DSP) functions in a hardware platform in a way that insulates it from the details of realization.

This thesis presents a tool-based methodolgy for developing and optimizing a Direct Sequence Spread Spectrum (DSSS) transceiver deployed in custom hardware like Field Programmble Gate Arrays (FPGAs). The system model consists of a tranmitter which employs a …