Engineering Commons^™

Control Of Low-Speed Turbulent Separated Flow Over A Backward-Facing Ramp, John C. Lin

Mechanical & Aerospace Engineering Theses & Dissertations

The relative performance and flow phenomena associated with several devices for controlling turbulent separated flow were investigated at low speeds. Relative performance of the devices was examined for flow over a curved, backward-facing ramp in a wind tunnel, and the flow phenomena were examined in a water tunnel using dye-flow visualization. Surface static pressure measurements and oil-flow visualization results from the wind tunnel tests indicated that transverse grooves, longitudinal grooves, submerged vortex generators, vortex generator jets (VGJ’s), Viets’ fluidic flappers, elongated arches +a + a (positive angle of attack), and large-eddy breakup devices (LEBU’s) +a + a placed near the …

Bs News

Building Services Engineering

No abstract provided.

Optimization Of Cryopreservation Protocols For Cardiovascular Tissue, Jianfei Hu

Theses and Dissertations in Biomedical Sciences

The purpose of this research was to determine the effects of cryopreservation on the physical, biochemical and cellular aspects of heart valve tissue. The present study demonstrated that radiolabeled proline accumulation provides a quantitative estimate of total cellular metabolic viability. Radiolabeled inulin was demonstrated to be a useful marker for extracellular tissue space. Assessment of metabolic viability of the cellular population of leaflet tissue as a function of procurement and processing revealed that proline accumulation declined with increasing warm and cold ischemic times. Amphotericin B and streptomycin were toxic to the cells. Cefoxitin, lincomycin, polymyxin B, vancomycin and penicillin had …

Shape Sensitivity Analysis And Optimization Of Skeletal Structures And Geometrically Nonlinear Solids, Ching-Hung Chuang

Mechanical & Aerospace Engineering Theses & Dissertations

Formulations and computational schemes for shape design sensitivity analysis and optimization have been developed for both skeletal structures and geometrically nonlinear elastic solids. The continuum approach, which is based on the weak variational form of the governing differential equation and the concept of the material derivative, plays a central role in such a development.

In the first part of this work, the eigenvalue and eigenvector sensitivity equations for skeletal structures are derived with respect to configuration variables of joint and support locations. This derivation is done by the domain method as well as the boundary method. The discrete approach for …

A Computational Aerodynamic Design Optimization Method Using Sensitivity Analysis, Mohamed E. Eleshaky

Mechanical & Aerospace Engineering Theses & Dissertations

A new and efficient procedure for aerodynamic shape optimization is presented. The salient lineaments of this procedure are: (1) using a discrete sensitivity analysis approach to determine analytically the aerodynamic sensitivity coefficients; (2) obtaining the flowfield solution either by a computational fluid dynamics (CFD) analysis or, alternatively, by a flowfield extrapolation method which is based on a truncated Taylor's series; (3) defining the aerodynamic shape in such a way that it is not restricted to any class of surfaces and the optimizer automatically shapes the aerodynamic configuration to any arbitrary geometry; and (4) requiring no expertise other than that needed …

Neural Network Based Vowel Articulation Training Aid For The Deaf, Andrew E. Beck

Electrical & Computer Engineering Theses & Dissertations

Teaching the hearing-impaired to speak is both a challenging and rewarding task. Computer-based training aids are valuable teaching tools and complement the speech therapist in the speech training process. We have developed a computer based vowel articulation training aid designed to provide visual feedback for vowel production to the hearing-impaired user. This system transforms speech spectra from a multi-dimensional acoustic space to a two-dimensional phonetic space which is displayed on a computer monitor. The system signal processing includes feature extraction designed to mimic the properties of the human ear, and a transformation to a two-dimensional display space. The dimensionality transformation …

Fault Coverage Measurement Technique For Analog Circuits, E. Paul Ratazzi

Electrical Engineering and Computer Science - All Scholarship

This report describes an effort to develop a technique for measuring the amount of fault detection coverage that an analog test pattern has for a particular analog device. The technique is based on a software tool which statistically analyzes data from a circuit simulator. One example of a fault simulation experiment is presented, and some of the results are discussed. Finally, some ideas for future work in this area are given.

Optimal Selection Of Metabolic Fluxes For In Vivo Measurement. Ii. Application To Escherichia Coli And Hybridoma Cell Metabolism, Joanne M. (Savinell) Belovich, Berhard O. Palsson

Chemical & Biomedical Engineering Faculty Publications

A method of analysis was presented in part I of this series for determining the fluxes in a biochemical network that are the optimal choices for experimental measurement. This algorithm is applied to two important biological models: Escherichia coli and a hybridoma cell line (167.4G5.3). Our results show that potentially poor choices for in vivo measurement of metabolic fluxes exist for both model systems. For the subset of reactions in E. coli that was studied, the condition number of the augmented stoichiometric matrix reveals that a 60-fold amplification of experimental error during computations is possible. The biochemical network of the …

Optimal Selection Of Metabolic Fluxes For In Vivo Measurement. I. Development Of Mathematical Methods, Joanne M. (Savinell) Belovich, Bernhard O. Palsson

Chemical & Biomedical Engineering Faculty Publications

The measurement of uptake and secretion rates is often not sufficient to allow the calculation of all internal metabolic fluxes. Measurements of internal fluxes are needed and these additional measurements are used in conjunction with mass-balance equations to calculate the complete metabolic flux map. A method is presented that identifies the fluxes that should be selected for experimental measurement, and the fluxes that can be computed using the mass-balance equations. The criterion for selecting internal metabolic fluxes for measurement is that the values of the computed fluxes should have low sensitivity to experimental error in the measured fluxes. A condition …

Mapping Programs To Parallel Architectures In The Real World, Dezheng Tang

Dissertations and Theses

Mapping an application program to a parallel architecture can be described as a multidimensional optimization problem. To simplify the problem, we divide the overall mapping process into three sequential substeps: partitioning, allocating, and scheduling, with each step using a few details of the program and architecture description. Due to the difficulty in accurately describing the program and architecture and the fact that each substep uses incomplete information, inaccuracy is pervasive in the real-world mapping process. We hypothesize that the inaccuracy and the use of suboptimal, heuristic mapping methods may greatly affect the mapping or submapping performance and lead to a …

Froth Flotation, Jiann-Yang Hwang

Michigan Tech Patents

A froth flotation apparatus includes a gas bubble-particle contact unit including a mixing means for breaking a gas into fine bubbles, such as a packed tower packing or mechanical agitation means, and a separate phase separation unit. A conditioned aqueous pulp containing a mixture of hydrophobic and hydrophilic particles and a substantially inert gas, such as air, are introduced into one end of the contact unit and flow concurrently through the mixing means, such that the gas is broken into fine bubbles which intimately contact and become attached to the hydrophobic particles. The resulting gas bubble-particle mixture is introduced into …

Method For Making Reshapable Articles Containing Lignocellulose Utilizing Polyisocyanate Resins, Bernard C. Sun

Michigan Tech Patents

Reshapable composite material and/or articles formed from lignocellulose-containing materials and having improved strength and water resistance characteristics are made by applying about 7 to about 100 weight % of a polyisocyanate resin to fibers and/or fiber bundles of a lignocellulose-containing material. The resulting mixture or furnish is compression molded to form a composite material and/or article of the desired shape and dimensions.

Steady-State Creep Deformation Of Investment Cast Near-Gamma Titanium Aluminide, D. A. Wheeler, B. London, D. E. Larsen Jr.

Materials Engineering

No Abstract.

Note On The Number Dependence Of Nonequilibrium Molecular Dynamics Simulations Of The Viscosity Of Structured Molecules, Richard L. Rowley, James F. Ely

Faculty Publications

Nonequilibrium molecular dynamics simulations have been performed for a system of 512 four-site models representing n-butane molecules. The results are compared to simulations previously reported for 125 molecules to check a recently reported number dependence in such simulations. A small system size dependence was observed at low shear rates, but the rheological behavior is not affected. Considerably greater certainty is obtained using larger systems.

An Investigation Into Manufacturing Quality Planning Concepts For New Manufactured Products With Recommendations For John Deere, Michael A. Henning

Graduate Research Papers

President Bush was quoted in 19 90 saying, "The improvement of quality in products and the improvement in services -these are national priorities as never before." (National, 19 9 0). Leadership through quality was also called the new competitive frontier by David Keams, Chief Executive Officer of Xerox Corporation (DeToro, 198 7) and 198 9 winner of the Malcolm Baldrige National Quality Award. For a manufacturing organization like Xerox a quality product is the result of many factors. Other corporations have come to the same realization of the importance of quality throughout their operations (Crosby, 19 9 1). He pointed …

Experimental Evaluation Of Incorporating Digital And Analog Integrated Circuit Die On A Common Substrate Utilizing Silicon-Hybrid Wafer-Scale Integration Technology, Philip C. Reamy

Theses and Dissertations

The objective of this research effort was to investigate the implementation of analog circuits in a wafer scale integration system. A test circuit composed of analog and digital subsystems was designed and tested through simulation. IC die containing this test circuit were utilized in the WSI system fabrication. Preliminary investigations were conducted to evaluate the potential improvements to the IC die mounting procedure, a key step in fabricating functional WSI systems. These investigations demonstrated a procedure which produced repeatable results in achieving acceptable planarization of IC die and host substrate surfaces. These investigations also demonstrated the successful application of a …

Temperature Oscillations Of Alternating-Current-Heated Thin Filaments In Ceramic Fiber Production, Hendrik J. Viljoen, Vladimir Hlavacek

Papers in Reaction Kinetics

Resistively heated filaments are used to manufacture ceramic fibers. When an ac power source is used for heating, the temperature of the filament oscillates. These oscillations influence the deposition rate on the surface of the filament. An analysis of this problem is presented, and it is also shown that these oscillatory effects diminish as the filament gauge increases. The analysis can help to decide whether an ac or a dc power source should be used.

A Mathematical Model And Simulation Of Natural Circulation Loop Thermalhydraulics, Nihad E. Daidzic

Aviation Department Publications

In this work, a simple, nonlinear, seventh-order mathematical model with lumped parameter analysis of the thermalhydraulic processes in a natural circulation steam boiler loop is presented. Digital simulation has been performed in order to predict open loop transients in severe accidental situations. Parts of the circulation loop such as the steam drum, downcomer, and riser were modelled separately on the basis of the integral balance equations. The two-phase flow in the steam drum and in the riser was modelled with the aid of a homogeneous-equilibrium, two-phase flow model. Special care was taken to ensure the stability of the numerical scheme, …

Energy-Efficient Lighting For Florida Homes, Florida Solar Energy Center, Danny Parker

FSEC Energy Research Center®

Although lighting doesn't constitute a major portion of the average homeowner's electric bill (generally from 3 to 15 percent), you can cut your lighting costs significantly by installing new energy-efficient bulbs. As an added plus for Florida residents, these new bulbs produce less heat, meaning less work for your air conditioner.

Transient Overvoltage Testing Of Environmental Controllers, Richard S. Gates, Larry W. Turner, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

The integrated electronic control system will provide a new method for the day-to-day management of environmental control of animal production systems. No standards are currently accepted for transient overvoltage protection of these controllers. To assess the adequacy of existing designs, a test circuit was designed and used for a transient open circuit over-voltage waveform (ANSI/IEEE C62.41-1980) of 16 environmental control units: a maximum spike of 770 V was applied to the power supplies, and a spike up to 100 V was applied to temperature sensor lines. For these relatively mild tests, no failures were noted due to power supply transients, …

Compact – A Reclamation Soil Compaction Model Part I. Model Development, Ronald L. Bingner, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

A physically based, event oriented soil compaction model, known as COMPACT, was developed as a management or research tool to evaluate the effect of surface mining systems on compaction of soil material during reclamation. Simulation of compaction throughout the soil profile at a surface mining reclamation site requires information describing how equipment moves on the site. The compaction processes that are caused by vehicles throughout the soil profile are described by applying the pressure distribution of the surface contact area of a tire or track to determine stresses in the soil profile. A virgin compression curve is then used to …

The Calendar - March 1992, Nova University

The Calendar

No abstract provided.

Detection, Location, And Quantification Of Structural Damage By Neural-Netprocessed Moire Profilometry, Barry G. Grossman, Frank S. Gonzalez, Joel H. Blatt, Jeffery A. Hooker

Electrical Engineering and Computer Science Faculty Publications

The development of efficient high speed techniques to recognize, locate, and quantify damage is vitally important for successful automated inspection systems such as ones used for the inspection of undersea pipelines. Two critical problems must be solved to achieve these goals: the reduction of nonuseful information present in the video image and automatic recognition and quantification of extent and location of damage. Artificial neural network processed moire profilometry appears to be a promising technique to accomplish this. Real time video moire techniques have been developed which clearly distinguish damaged and undamaged areas on structures, thus reducing the amount of extraneous …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 8, Number 3, March 1992, 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.

Energy Savings From Industrialized Housing Construction Systems And Roofing Tiles, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

Side-by-side tests were conducted in Cape Canaveral, FL to compare the cooling and heating energy use and electric peak demand requirements for two industrialized (Dow and Dome) and one conventional room-sized prototypes. The industrialized prototypes saved 11% to 16% in cooling energy and 45% to 56% in heating energy. The industrialized prototypes peak demand savings was 16% to 23% for cooling and 39% to 42% for heating. The energy performance of the Dome prototype was slightly better than that of the Dow. These results were as expected and are largely due to the higher insulation levels and greater air tightness …

Compact – A Reclamation Soil Compaction Model Part Ii. Sensitivity Analysis And Applications, Ronald L. Bingner, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

COMPACT, a physically based, event-oriented compaction model, was developed as a management or research tool to evaluate the influence of a surface mining system on compaction of soil material during reclamation. Two systems of area mining reclamation operations were simulated by COMPACT. The first system involved scrapers and bulldozers and the second also included trucks. Scrapers or trucks were used to pick up and deposit the soil material. Bulldozers were then used to shape the site for reclamation. The simulated results were compared with measured results and show how equipment patterns and soil parameters can affect overall soil compaction. This …

A Lower-Bound For The Error-Variance Of Maximum-Likelihood Delay Estimates Of Discontinuous Pulse Waveforms, Kurt Louis Kosbar, Andreas D. Polydoros

Electrical and Computer Engineering Faculty Research & Creative Works

A new lower bound is developed for the error variance of maximum-likelihood time-delay estimation when the received signal is a square pulse, corrupted by additive white Gaussian noise. The bound is generated by combining concepts previously developed for a special class of stochastic processes, induced by the signal model. For moderate signal to noise ratios, the new bound is significantly tighter than previously known ones.

The Effect Of Flange Restraint On Web Crippling Strength, Bhavnesh H. Bhakta, Roger A. Laboube, Wei-Wen Yu

CCFSS Library (1939 - present)

PREFACE When considering the web crippling strength of a cold-formed steel member, the current edition of the AISI Specification for the Design of Cold-Formed Steel Structural Members does not distinguish between the behavior of a member having its flanges attached to a support member, and a member not attached to its support. To enhance the industry and design professional's understanding of web crippling, a pilot study was initiated at the University of Missouri-Rolla to explore the influence of flange attachment. The financial assistance for this research was provided by the Metal Building Manufacturers Association (MBMA) and the American Iron and …

The Safety Risks Of Proposed Fuel Economy Legislation, John D. Graham

RISK: Health, Safety & Environment (1990-2002)

Based on, e.g., a comprehensive assessment of what is known of factors influencing automobile safety, previous industry responses to requirements for fuel economy and prior success of regulators in reducing injuries, Professor Graham concludes that pending fuel economy bills are apt to add 1650 fatalities and 8500 serious accidents to the annual highway toll. He also presents several short-term and long-term strategies for simultaneously saving fuel and lives.

Three-Dimensional Insulated Gate Bipolar Transistor (Igbt) Development, P.V. Gilbert, G.W. Neudeck

Department of Electrical and Computer Engineering Technical Reports

A new insulated gate bipolar transistor structure, the 3D-IGBT, is presented. The 3D-IGBT utilizes selective epitaxial silicon to form a top contacted anode and still retain the cellular structure of vemcally oriented devices. The 3D-IGBT , unlike other fully integrable power devices, exploits the merits of cellular structure to increase its packing density and thus reduce its on-resistance per unit area. It also eliminates the parasitic JFET resistance found in vertical IGBT's. To integrate the 3D-IGBT with low power devices, the QDI method of device isolation is also presented. QDI uses a combination of JI and DI to electrically isolate …