Engineering Commons^™

Neural Network Fatigue Life Prediction In 7075-T6 Aluminum From Acoustic Emission Data, Emeka Chigozie Ibekwe

Master's Theses - Daytona Beach

The objective of this research was to classify acoustic emission (AE) -data associated with fatigue cracks in aluminum fatigue specimens and to use early cycle life AE data to predict failure in such members. An AE data acquisition system coupled with a Kohonen self organizing map and a back propagation neural network were used to perform the analysis. AE waveforms were recorded during fatigue cycling of twenty-four notched 7075-T6 aluminum specimens using broad-band piezoelectric transducers. A Kohonen self organizing map was used to classify the AE flaw growth signals. The signals were classified into three categories based on their AE …

A Comparison Between Growth Morphology Of "Eutectic" Cells/Dendrites And Single-Phase Cells/Dendrites, Surendra N. Tewari, S. V. Raj, L. E. Locci

Chemical & Biomedical Engineering Faculty Publications

Directionally solidified (DS) intermetallic and ceramicbased eutectic alloys with an in-situ composite microstructure microstructure containing finely distributed, long aspect ratio, fiber, or plate reinforcements are being seriously examined for several advanced aero-propulsion applications. In designing these alloys, additional solutes need to be added to the base eutectic composition in order to improve their high temperature strength, and provide for adequate toughness and resistance to environmental degradation. Solute addition, however, promotes instability at the planar liquid-solid interface resulting in the formation of two-phase eutectic “colonies.”[1–4] Because morphology of eutectic colonies is very similar to the single-phase cells and dendrites, the stability …

Characterisation Of The Glass Fraction Of A Selection Of European Coal Fly Ashes, J. Henry, Mark R. Towler, K. T. Stanton, X. Querol, N. Moreno

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fly ash largely consists of the inorganic content of coal that remains after combustion. The crystalline phases present in fly ash may form upon cooling of a molten alumino-silicate glass. This view is supported by the spherical shape of many fly ash particles, inferring that they have gone through a viscous fluid state. The amorphous content in fly ash is believed to dominate reactivity behaviour, under both alkaline and acid conditions, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass makes the bond breakage easier. It …

A Sequential Approach To Modeling Catalytic Reactions In Packed-Bed Reactors, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Sequential Modeling Approach is Proposed to Simulate Catalytic Reactions in Packed-Bed Reactors. the Hydrogenation of Alpha-Methylstyrene and Wet Oxidation of Phenol Are Selected as Studied Cases. the Modeling Scheme Combines a Reactor Scale Axial Dispersion Model with a Pellet Scale Model. Without Involving Any Fitting Parameters, Such an Approach Accounts for the Non-Linear Reaction Kinetics Expression and Different Types of Pellet-Liquid Wetting Contact. to Validate the Developed Modeling Scheme and the Parallel Approach Reported in the Literature, the Experimental Observations for Hydrogenation of Alpha-Methylstyrene to Cumene Have Been Employed. the Predicted Results by Both Approaches Agree Reasonably with the …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 7, May 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Deterministic And Probabilistic Test Generation For Binary And Ternary Quantum Circuits, Sowmya Aligala, Sreecharani Ratakonda, Kiran Narayan, Kanagalakshmi Nagarajan, Martin Lukac, Jacob D. Biamonte, Marek Perkowski

Electrical and Computer Engineering Faculty Publications and Presentations

It is believed that quantum computing will begin to have an impact around year 2010. Much work is done on physical realization and synthesis of quantum circuits, but nothing so far on the problem of generating tests and localization of faults for such circuits. Even fault models for quantum circuits have been not formulated yet. We propose an approach to test generation for a wide category of fault models of single and multiple faults. It uses deterministic and probabilistic tests to detect faults. A Fault Table is created that includes probabilistic information. If possible, deterministic tests are first selected, while …

Heat Transfer In A Thin Liquid Film In The Presence Of An Electric Field, Rama Subba Reddy Gorla, Jorge E. Gatica, Bahman Ghorashi, Pijarn Ineure, Larry W. Byrd

Chemical & Biomedical Engineering Faculty Publications

Heat transfer enhancement in an evaporating thin liquid film utilizing a electric field under isothermal interfacial condition is presented. A new mathematical model subjected to van der Waals attractive forces, capillary pressure, and an electric field is developed to describe the heat transfer enhancement in the evaporating thin liquid film. The effect of the electrostatic field on the curvature of the thin film, evaporative flux, pressure gradient distribution, heat flux, and heat transfer coefficient in the thin film is presented. The results show that applying an electric field can enhance heat transfer in a thin liquid film significantly. in addition, …

A Vocalisation-Based Drawing Interface For Disabled Children, Ted Burke

Articles

In our work with disabled children at Ireland’s National Rehabilitation Hospital, a problem we have experienced in the facilitation of art activities is that traditional art materials and standard computer drawing programs sometimes prove inaccessible. In this paper, an original system, called “PaintMyVoice” is presented which facilitates the creation of two or three-dimensional images using a variety of novel input modalities. In particular, vocalisations can be used to create original images of a variety of objects, including trees, flowers and landscape elements. Additional input to the system can optionally be provided via mouse, keyboard, switch interface or digital camera depending …

Fusion And Perspective Correction Of Multiple Networked Video Sensors, Christopher E. Neely, John W. Lookwood

All Computer Science and Engineering Research

A network of adaptive processing elements has been developed that transforms and fuses video captured from multiple sensors. Unlike systems that rely on end-systems to process data, this system distributes the computation throughout the network in order to reduce overall network bandwidth. The network architecture is scalable because it uses a hierarchy of processing engines to perform signal processing. Nodes within the network can be dynamically reprogrammed in order to compose video from multiple sources, digitally transform camera perspectives, and adapt the video format to meet the needs of specific applications. A prototype has been developed using reconfigurable hardware that …

Interim Sediment Management Plan For First Dam, Logan River, Thirumurugan Bose

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

Sediment is a serious problem in the management of dams all over the world. In this project an interim sediment management plan for First Dam, on the Logan River in northern Utah, is discussed. The objective of the plan is to control the sediment budget of the reservoir in such a way that other reservoir maintenance activities (e.g., unusual draw downs for structural repairs) will produce minimal downstream environmental impacts on water quality and aquatic resources.

This report presents a detailed literature review of the various sediment management practices used for reservoir sediment control. It also discusses the downstream effects …

Nebraska Summary S466: Massey Ferguson 6480 Diesel 32-Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Susceptibility Characterization Of A Cavity With An Aperture By Using Slowly Rotating Em Fields: Fdtd Analysis And Measurements, Kimitoshi Murano, Takeshi Sanpei, Fengchao Xiao, Chen Wang, Yoshio Kami, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes the evaluation of the susceptibility of a cavity with an aperture using the finite-difference time-domain (FDTD) method and experimentally. To reduce the computing time, the FDTD method is used for the radiation from the cavity and the susceptibility is obtained by using the reciprocity theorem. The cavity used here is modeled after a full-tower desktop enclosure with a 3.5-in bay. The susceptibility characteristics are evaluated by measuring outputs of a monopole antenna and transmission lines installed in the cavity. The susceptibility characteristics, using a three-dimensional (3-D) map, are studied from the computed and the measured results by …

Control Of Cascaded Multilevel Inverters, Keith Corzine, M. W. Wielebski, Fang Zheng Peng, Jin Wang

Electrical and Computer Engineering Faculty Research & Creative Works

A new type of multilevel inverter is introduced which is created by cascading two three-phase three-level inverters using the load connection, but requires only one dc voltage source. This new inverter can operate as a seven-level inverter and naturally splits the power conversion into a higher-voltage lower-frequency inverter and a lower-voltage higher-frequency inverter. This type of system presents particular advantages to Naval ship propulsion systems which rely on high power quality, survivable drives. New control methods are described involving both joint and separate control of the individual three-level inverters. Simulation results demonstrate the effectiveness of both controls. A laboratory set-up …

Determination Of The Thickness And Dielectric Constant Of A Dielectric Slab Backed By Free-Space Or A Conductor Through Inversion Of The Reflection Coefficient Of A Rectangular Waveguide Probe, Jesse Lai, Dana M. Hughes, Eric Gallaher, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

Evaluation of thickness and material properties of coatings and dielectric slabs is an important practical issue. Microwave nondestructive testing techniques, using open-ended rectangular waveguide and coaxial probes have shown great potential for this purpose. However, to evaluate one parameter requires that the other be known a priori. This paper discusses the use of a relatively efficient method for evaluating both parameters simultaneously from measurements of the reflection coefficient of a test material. Results of two cases as well as a brief discussion of the limitations of the technique are provided in this paper.

High Confidence Testing For Instrumentation System-On-Chip With Unknown-Good-Yield, N. J. Park, Bin Jin, Koshy M. George, Nohpill Park, Minsu Choi

Electrical and Computer Engineering Faculty Research & Creative Works

SoCs are in general built with embedded IP cores, each of which is procured from different IP providers with no prior information on known-good-yield (KGY). In practice, partial testing is a practical choice for assuring the yield of the product under the stringent time-to-market requirements. Therefore, a proper sampling technique is a key to high confidence testing and cost effectiveness. Based on previous research, this paper proposes a novel statistical testing technique for increasingly hybrid integrated systems fabricated on a single silicon die with no a-priori empirical yield data. This problem is referred to as the unknown-good-yield (UKGY) problem. The …

Foot And Ankle Forces During An Automobile Collision: The Influence Of Muscles, Elizabeth C. Hardin, Anne Su, Antonie J. Van Den Bogert

Mechanical Engineering Faculty Publications

Muscles have a potentially important effect on lower extremity injuries during an automobile collision. Computational modeling can be a powerful tool to predict these effects and develop protective interventions. Our purpose was to determine how muscles influence peak foot and ankle forces during an automobile collision. A 2-D bilateral musculoskeletal model was constructed with seven segments. Six muscle groups were included in the right lower extremity, each represented by a Hill muscle model. Vehicle deceleration data were applied as input and the resulting movements were simulated. Three models were evaluated: no muscles (NM), minimal muscle activation at a brake pedal …

Electromagnetic Interference (Emi) Of System-On-Package (Sop), Toshio Sudo, Hideki Sasaki, Norio Masuda, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

Electromagnetic interference (EMI) issues are expected to be crucial for next-generation system-on-package (SOP) integrated high-performance digital LSIs and for radio frequency (RF) and analog circuits. Ordinarily in SOPs, high-performance digital LSIs are sources of EMI, while RF and analog circuits are affected by EMI (victims). This paper describes the following aspects of EMI in SOPs: 1) die/package-level EMI; 2) substrate-level EMI; 3) electromagnetic modeling and simulation; and 4) near electromagnetic field measurement. First, LSI designs are discussed with regard to radiated emission. The signal-return path loop and switching current in the power/ground line are inherent sources of EMI. The EMI …

The Influence Of Environmental Temperature And Substrate Initial Moisture Content On Aspergillus Niger Growth And Phytase Production In Solid−State Cultivation, Seaborn B. Carter, Sue E. Nokes, Czarena L. Crofcheck

Biosystems and Agricultural Engineering Faculty Publications

Aspergillus niger is being used commercially for phytase production utilizing solid-state cultivation; however, no studies have been published that investigated the optimal environmental temperature and initial substrate water content to maximize fungal growth and/or phytase production. Solid-state cultivations of Aspergillus niger on wheat bran and soybean meal were conducted at three temperatures (25°C, 30°C, and 35°C) and three initial moisture contents (50%, 55%, and 60% wet basis) in a split-plot full-factorial experimental design. Fermentations were conducted for 0, 24, 48, 72, and 120 h. The containers were sampled destructively and assayed for phytase activity and glucosamine concentration as an estimate …

Effect Of Stover Fraction On Glucose Production Using Enzymatic Hydrolysis, Czarena L. Crofcheck, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

Corn stover was fractionated into three fractions: cobs, stalks, and leaves and husks. The fractions were dried and ground through a 2 mm screen. Samples of the three fractions and whole corn stover with and without NaOH pretreatment were subjected to enzymatic hydrolysis in order to determine the effect of fractionation on glucose production. The average amounts of glucose released after 60 h of hydrolysis from pretreated cobs, leaves and husks, stalks, and whole stover were 0.50, 0.36, 0.28, and 0.36 g/g dry biomass, respectively. The average amounts of glucose released after 60 h of hydrolysis from nonpretreated cobs, leaves …

Determination Of Dielectric Property Profile In Cement-Based Materials Using Microwave Reflection And Transmission Properties, Bharath Akuthota, R. Zoughi, K. E. Kurtis

Electrical and Computer Engineering Faculty Research & Creative Works

Microwave characterization methods are effective means for evaluating dielectric properties of materials and correlating them to their important physical, chemical and mechanical properties. For characterization purposes most materials are considered homogeneous and the measurement of their dielectric properties is fairly straightforward. However, certain materials may be considered inhomogeneous in such a way that their dielectric properties vary in a preferred direction within the material. To evaluate the dielectric property profile of these materials an electromagnetic model is necessary that can be used along with their measured reflection and transmission properties. This paper presents the development of such a model which …

A Web-Shareable Real-World Imaging Problem For Enhancing An Image-Processing Curriculum, R. Joe Stanley, Steve Eugene Watkins, Anand Gopal, Randy Hays Moss

Electrical and Computer Engineering Faculty Research & Creative Works

A real-world laboratory exercise is presented for image processing and related curricula. The exercise is a traffic-monitoring problem in which a truck must be tracked as it moves across a bridge and its velocity measured. Sequential images are taken from a dedicated Web camera that views the Smart Composite Bridge on the University of Missouri-Rolla campus. The prototype bridge is a field laboratory for several interdisciplinary courses, including a Machine Vision elective. The Machine Vision image-processing elective uses the traffic-monitoring exercise to give students experience with processing complex images, tracking image markers, and applying theoretical orthographic concepts. The laboratory exercise …

Pulse Train Control Technique For Flyback Converter, Mark Telefus, Anatoly Shteynberg, Mehdi Ferdowsi, Ali Emadi

Electrical and Computer Engineering Faculty Research & Creative Works

Pulse Train^TM control technique is introduced and applied to flyback converter operating in discontinuous conduction mode (DCM). In contrast to the conventional pulse width modulation (PWM) control scheme, the principal idea of Pulse Train is to achieve output voltage regulation using high and low power pulses. The proposed technique is applicable to any converter operating in DCM. However, this work mainly focuses on flyback topology. In this paper, the main mathematical concept of the new control algorithm is introduced and simulations as well as experimental results are presented.

Cost-Driven Optimization Of Fault Coverage In Combined Built-In Self-Test/Automated Test Equipment Testing, Shanrui Zhang, Minsu Choi, Nohpill Park, Fabrizio Lombardi

Electrical and Computer Engineering Faculty Research & Creative Works

As the design and fabrication complexities for the instrumentation-on-silicon systems intensify, optimization of combined Built-In Self-Test (BIST) and Automated Test Equipment (ATE) testing becomes more desirable to meet the required fault-coverage while maintaining acceptable cost overhead. The cost associated with combined BIST/ATE testing of such systems mainly consists of the following; (1) the cost induced by the BIST area overhead and (2) the cost induced by the overall testing time. In general, BIST has faster testing speed than ATE, while it can provide only limited fault-coverage and driving higher fault-coverage from BIST means additional area cost overhead. On the other …

Processing And Optimization Of Natural Fiber Reinforced Composites Using Date Palm Fibers, Khalifa Musabbeh Suwaidan Hamad Al-Kaabi

Theses

During the last twenty years, ecological concerns have resulted in a renewed interest in natural materials. Composite materials usually depend on using man-made fibers as the reinforcing element. The possibility of using natural fibers instead of synthetic fibers is gaining acceptance among users. This work aims to investigate the possibility of extracting natural fibers from date palm trees to be used as reinforcement with polymeric materials. The objective was achieved by characterizing fibers through different chemical, physical and mechanical tests and using different treatment methods in order to modify the fiber properties. Date Palm Fibers (DPF) exhibit a cylindrical shape …

Synthesis And Characterization Of Polyaniline And Poly (3-Methylthiophene) As Conducting Polymers, Fatma Khalifa Obaid Dalmouk

Theses

The performance of materials in general depends on their properties. There is a continuous need of new materials to meet the technological revolution that was witnessed by the end of last century. In this work, a new class of materials was synthesized. The host matrix is an Organic Conducting Polymer (OCP) of either poly(3-methylthiophene) (PMT) or poly(aniline) (PAN). The synthesis of OCP is achieved using electrochemical methods of applying constant potential or cyclic voltammetry at a platinum or graphite substrate in an acetonitrile containing tetra-alkyl-ammonium salt. The set up is three-electrode system of a platinum counter electrode and a silver/silver …

Bulk Polymerization And Structure-Property Relationship Of Medical Grade Polyurethane, Mariam Nasser Al-Saedi

Theses

Polyurethanes as biomaterials have been used in the augmentation and repair of the human body with great success. The choice of material for a particular application often hinges on the body's response to the polymer, the mechanical and thermal properties of the polymer and the stoichiometric ratio of active ingredients used in the synthesis.

A large number of polyurethanes used in medical applications are polyester-based and cannot be used in long-term implant applications because they are very susceptible to hydrolysis. Other medical-grade polyurethanes, which are suitable for implants are polyether-based which might to some extent, suffer from environmental stress cracking …

Modeling Switched-Reluctance Machines By Decomposition Of Double Magnetic Saliencies, Farzad R. Salmasi, Babak Fahimi

Electrical and Computer Engineering Faculty Research & Creative Works

This paper presents a novel analytical model for a switched-reluctance machine (SRM) based on decomposition of its inherent double joint magnetic saliencies due to rotor and stator salient poles and saturation of magnetic field at high stator currents. with this method, the magnetic characteristics of the motor, such as flux linkage and incremental inductance, are decomposed to vector functions of rotor position and phase current. Dynamic state and torque equations for the SRM are derived on the basis of this representation. the proposed model is appropriate for online identification and for sensor less position control algorithms. It is easy to …

Statewide Listing Of Bridges With Possible Historical Significance, Indiana Ltap

Indiana Local Technical Assistance Program (LTAP) Publications

This reports documents the efforts of the Indiana LTAP Center to create a statewide inventory of bridges that may be historically significant and was the first step in the development of a management plan for the preservation of the most significant historic bridges and a programmatic agreement in lieu of the standard Section 106 procedure for the less significant bridges.

Included in this report is a description of the work performed by Indiana LTAP, a description of the work to be performed by others as determined by the Historic Bridge Task Force, various summary tables and complete listings of the …

Adaptive Optimal Control Design For Stable Vibration Attenuation Of Active Constrained Layer Damping Beam Structure, Tatyana G. Korotkova-Egan

Theses and Dissertations - UTB/UTPA

Vibration suppression using active constrained layer damping (ACLD) has proven to be an invaluable means for improving the performance of a wide variety of engineering systems. The ACLD creates the hybrid of active and passive damping, attaining favorably high damping characteristics, while at the same time, combines unattractive attributes of both treatments, such as stability sensitivity. Control efforts are needed to achieve an adequate performance of the structures treated with ACLD. The purpose of this research is to investigate theoretically and numerically the adaptive optimal controller of the constrained layer damped beam system, using the classical three-layered distributed-parameter model that …

Control Strategies For Active Power Sharing In A Fuel-Cell-Powered Battery-Charging Station, Zhenhua Jiang, Roger A. Dougal

Faculty Publications

This paper presents an effective system design for a fuel-cell-powered battery-charging station and three control strategies for active power sharing among the batteries. This battery-charging station allows multiple batteries to be simultaneously charged. Three control strategies were investigated to coordinate the active power distribution among the battery-charging branches. The baseline control strategy Was equal rate charging. Two advanced control strategies, proportional rate charging and pulse current charging, were compared to the baseline strategy. These control strategies were realized in MaTLaB/Simulink, and the current and voltage regulations were implemented using the classical proportional-integral control approach. The system simulation was conducted in …