Engineering Commons^™

Phase Changes In Plasma‐Sprayed Zinc‐Nickel Ferrite, T. A. Dooling, Desmond C. Cook

Physics Faculty Publications

The magnetic and crystalline properties of a plasma‐sprayed coating of the microwave absorbing zinc‐nickel ferrite, (Zn_0.41Ni_0.59 )Fe₂O₄ have been studied at 300 K using the Mössbauer effect and x‐ray diffraction (XRD). Both techniques indicate that the plasma‐sprayed material separated into two phases. The first is a nickel‐rich phase with magnetic fields of 47.5 and 44.5 T at the tetrahedral and octahedral sites, respectively. The second is a zinc‐rich phase, zinc meta‐ferrite, having a small magnetic field of 4.2 T. The quadrupole splitting of this second phase is ΔE=0.34 mm s⁻¹, …

Thermal Compatibility Analysis Of The Passive Damping Treatment Proposed For The Space Shuttle Remote Manipulator System (Srms), Mahesh Chowdhary

Mechanical & Aerospace Engineering Theses & Dissertations

The NASA Space Shuttle Remote Manipulator System (SRMS), due to its long reach and light weight construction has significant structural flexibility. Thus any routine use of SRMS often results in large amplitude oscillations with long settling time. A passive damping technique utilizing a constrained viscoelastic layer damping treatment has been proposed to augment the active control of these oscillations in order to enhance the system stability and the end effector positional accuracy. This thesis concerns with the thermal compatibility analysis of the proposed damping treatment. The necessity for thermal compatibility analysis arises from the fact that acceptable damping performance of …

Analytical Modeling And Simulation For Investigation Of A Digital Gas Filter Correlation Radiometer, Catherine P. Mcgowan

Electrical & Computer Engineering Theses & Dissertations

This thesis investigates a digital gas filter correlation radiometer called the Tropospheric Radiometer for Atmospheric Chemistry and Environmental Research (TRACER), which will be used to remotely measure carbon monoxide at three levels in the troposphere. The nadir-viewing radiometer measures the differential absorption of radiation through the atmosphere at 4.67@m and 2.33pm wavelengths. This thesis develops an analytical model of the TRACER measurement process to evaluate the effect of varying certain system parameters on the measurement. The independent sampling criterion and the response of linear systems to random signals are explained. A parametric simulation model is also developed to evaluate the …

An Erasable Optical Memory Based On Stimulated Electronic Transition Concept, James D. Satira

Electrical & Computer Engineering Theses & Dissertations

Erasable optical memory systems with a high storage density and a large data transfer rate are required for many real time data acquisition systems such as those placed aboard NASA's space born platforms. A new concept for erasable optical memory involving stimulated electronic transitions (SET) will meet these requirements. The SET concept useful in erasable optical storage systems was demonstrated in MgS and SrS doped with Eu and Sm. The optical properties of these materials were studied. The reading and writing wavelengths for these samples were determined to be 950 and 514 nm respectively. The peaks of the emission spectra …

The Breakdown Mechanism Of Hollow Cathode Discharge, Mai Tuyet Ngo

Electrical & Computer Engineering Theses & Dissertations

In a low pressure discharge, if the cathode incorporates a cylindrical or slit shaped hole, the discharge current can be several orders of magnitude higher than in one with plane parallel electrodes under the same pressure and voltage conditions. In this work hollow cathode discharges in Helium under the influence of variable parameters such as gas pressure, applied voltage, electrode gap spacing, external magnetic field, etc., are investigated by means of electrical and optical diagnostic techniques.

The results indicate that a hollow cathode discharge develops in two stages. The initial breakdown occurs along the longest straight path of the system, …

Magneto-Optical Kerr Effect And Perpendicular Magnetic Anisotropy Of Evaporated And Sputtered Co/Pt Multilayer Structures, Ping He, William A. Mcgahan, John A. Woollam, F. Sequeda, T. Mcdaniel, H. Do

Department of Electrical and Computer Engineering: Faculty Publications

Thin and ultrathin Co/Pt multilayered structures have been prepared on glass substrates by electron-beam evaporation at room temperature and by sputtering at various substrate temperatures and sputtering pressures. Perpendicular magnetic anisotropy was found in samples with Co/Pt bilayer thicknesses near 3 Å/l0 Å and total thicknesses of the layer stack of no greater than 300 Å. X-ray diffraction was performed on the samples to determine layer spacing and integrity, and possible crystallinity of films. Crystalline structures in the interface between the Co and Pt layers were found and identified. The effects of sputtering parameters, such as pressure and substrate temperature, …

Development Of Turning Templates For Various Design Vehicles, Kenneth R. Agent, Jerry G. Pigman

Kentucky Transportation Center Research Report

The objective of this study was to develop the data necessary to produce the turning templates that would represent the minimum turning paths for critical design vehicles. This would include information concerning truck turning radii and offtracking for larger trucks with varying wheelbases operating in Kentucky. In order for the turning templates used for the various design vehicles to be based on the same procedure, data were produced tor design vehicles ranging from a passenger car to a combination truck with a 53 foot trailer. The simulation model used was the Truck Offtracking Model (TOM) and was developed by the …

Finite Element Analysis Of Thermal Post-Buckling And Vibrations Of Thermally Buckled Composite Plates, Charles Clifton Gray

Mechanical & Aerospace Engineering Theses & Dissertations

The development of supersonic and hypersonic flight vehicles such as the High Speed Civil Transport and the National Aero-Space Plane has created an increased need for analysis of structures at very high temperatures. Bisplinghoff and Pian, Yang and Han, and Dokmeci and Boley have conducted experimental and analytical studies to determine the effect of elevated temperatures on the vibration characteristics of isotropic plates, Chen and Chen, and Meyers and Hyer have clone studies on thermal buckling and post-buckling of composite plates, respectively.

The thermal loads which will be imposed on the new high speed aircraft will be too great for …

Development And Characterization Of Monoclonal Antisperm Antibodies: Potential For Contraception, Dilrowshan H. Haque

Theses and Dissertations in Biomedical Sciences

There is an expressed need to develop a greater variety of safe contraceptive methods which would find acceptance worldwide, particularly in developing countries. Immunization against spermatozoa might be such a method as judged by the accumulated evidence from studies on human females and in a number of female animal species.

Two extraction techniques were used for sperm membrane antigen isolation. The first technique involved NP-40 detergent for antigen extraction from human motile sperm and the second technique employed homogenized human testis for antigen extraction. Using these immunogens, sperm membrane-specific monoclonal antibodies (MAbs) were developed. When these antisperm MAbs were subjected …

Large-Amplitude Finite Element Flutter Analysis Of Composite Panels In Hypersonic Flow, Carl E. Gray Jr.

Mechanical & Aerospace Engineering Theses & Dissertations

A finite-element approach is presented for determining the nonlinear flutter characteristics of two-dimensional isotropic and three-dimensional composite laminated thin panels using the third-order-piston, transverse loading, aerodynamic theory. The unsteady, hypersonic, aerodynamic theory and the von Karman large deflection plate theory are used to formulate the aeroelastic problem. Nonlinear flutter analyses are performed to assess the influence of the higher-order aerodynamic theory on the structure's limit-cycle amplitude and the dynamic pressure of the flow velocity. A solution procedure is presented to solve the nonlinear panel flutter and large-amplitude free vibration finite element equations. This procedure is a linearized updated mode with …

Sedimentology Of The Bedford-Berea Sequence (Early Mississippian), Williams Field, Michigan, David Alan Balthazor

Masters Theses

The Berea Sandstone has produced in excess of 1.6 million barrels of oil in the Williams field since discovery in 1980. Seven lithofacies are identified from conventional core in the Bedford-Berea sequence. These facies are interpreted as deltaic deposits comprising prodelta (Bedford Shale), delta front, destructive marine shale, abandoned distributary channel-fill, interdistributary bay-fill, transgressive marine sandstone, and marine shale (Sunbury Shale) facies. Passive channel-fill facies truncate reservoir sandstone bodies and compartmentalize the field NW-SE across the trend of the northwestplunging anticline.

The two reservoir facies in the Williams field are the delta front and transgressive marine sandstones. The sandstone framework …

Two-Dimensional Heat Loss From A Building Slab Including Convective Effects In Saturated Soil, William W. Rust Iii

Mechanical & Aerospace Engineering Theses & Dissertations

The heat loss from a building slab was investigated. The continuity equation, Darcy's Law and the energy equation were formulated to include the temperature dependence of viscosity and density of water. The governing equations and appropriate boundary conditions were transformed into dimensionless variables. A finite difference numerical scheme was constructed based on the Gauss-Seidel method by lines and solved iteratively in alternating directions. A correlation between the geometrical characteristics of the domain, the convective surface heating parameters, and the total nondimensional slab heat loss in two dimensions was discovered. Furthermore, the correlation was extended to three-dimensional slabs and produced good …

Simulator For Concurrent Processing Data Flow Architectures, Mahyar R. Malekpour

Electrical & Computer Engineering Theses & Dissertations

A software simulator capable of simulating execution of an algorithm graph on a given system under the Algorithm To Architecture Mapping Model (ATAMM) rules is presented in this thesis. ATAMM is capable of modeling the execution of large-grained algorithms on distributed data flow architectures. Investigating the behavior and determining the performance of an ATAMM based system requires the aid of software tools. The ATAMM Simulator presented in this thesis is capable of determining the behavior, performance, and reliability of a system without having to build a hardware prototype. Case studies are performed on four algorithms to demonstrate the capabilities of …

An Architecture Level Simulation Methodology, Paul D. Stigall, Ram Huggahalli

Electrical and Computer Engineering Faculty Research & Creative Works

Using the Architecture Design and Assessment System (ADAS), the Processor Level Architecture of an Example Computer System is First Represented as a Directed Graph. Then, a Method of Simulating Instruction Execution as a Sequence of Data Transfers between the Nodes of the Graph is Presented. the Simulation Methodology Provides Flexibility in Observing the Architecture Dynamically at the Processor Level. an Example Application for Functional Verification is Discussed. Development of Techniques to Convert Programs into Node Sequences And, to Assign Appropriate Delays to the Nodes is Necessary to Further Enhance the Applicability of the Methodology. Functional Verification and Performance Estimation through …

Removal Of Chlorine From Chlorine-Nitrogen Mixture In A Film Of Liquid Water, Sarwan S. Sandhu

Chemical and Materials Engineering Faculty Publications

In industry there are many examples of absorption of a gas with or without chemical reaction in the liquid phase. In physical absorption, a particular gaseous component is removed from a gas mixture due to its larger solubility in the liquid phase solvent. The removal of butane and pentane from a refinery gas mixture by a heavy oil in the liquid phase is an example of physical absorption. In absorption with chemical reaction, the gaseous component to be removed transfers across the gas-liquid interface due to a difference in the bulk chemical potentials or concentrations in the two phases. The …

Method For Compression Molding Articles From Lignocellulosic Materials, Robert D. Palardy, Bruce A. Haataja, Andrew D. Williams

Michigan Tech Patents

Flakeboard or particle board panels and other composite articles made from wood flakes or other particulate lignocellulosic materials having a relatively high internal bond and improved resistance to moisture are made from flakes or particles which have a moisture content of at least 15%. A catalyst capable of accelerating the reaction between the flakes or particles, the binder and water is applied to the flakes or particles prior to the addition of a moisture-tolerant particle board binder, such as an organic polyisocyanate. A mat of the resulting furnish is compression shaped under pressure and at a temperature less than 250° …

Afit/Afosr Symposium On Applications Of Wavelets To Signal Processing, Volume Ii, Tutorial Notes, Gregory T. Warhola, Mark E. Oxley, Steven K. Rogers, Matthew Kabrisky, Bruce W. Suter

AFIT Documents

The Air Force Institute of Technology (AFIT) hosted the Symposium on Applications of Wavelets to Signal processing during 20-22 March 1991 at the AFIT Science and Research Center, Wright-Patterson AFB, OH. This was the first major academic meeting of its kind held at AFIT. The symposium was sponsored by the Air Force Office of Scientific Research (AFOSR), Bolling AFB, DC. It focused on applications of wavelets to problems in image and speech processing, communications, and graphics and opened with a one-day short course, 'A Tutorial on Wavelets.' The symposium was attended by more than 220 researchers worldwide. They represented 15 …

Transient Heat Transfer Measurements On A Film Cooled Flat Plate In A Shock Tube, Rakhman Gul

Theses and Dissertations

During this study a simple model of a flat plate was chosen to determine heat flux from a high speed flow behind a shock wave into the film cooled flat plate. An electrical analog was used to convert the output of the heat flux gages into heat flux. Free stream turbulence within the flow behind the shock wave and that generated by a turbulence generator was determined and its effects on the heat transfer data were then studied for comparison with previous experimental work. The thin-film heat flux gages were calibrated and their calibration constants were then used to determine …

Effect Of Local Soil Stratigraphy On Microtremor Measurements, George Bouckovalas, Ioanna Krikeli

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The method of microtremors has been recently applied for the microzonation of the town of alamata, in southern Greece. Results from this study are evaluated in comparison with predictions of seismic ground response obtained by 1-D wave propagation analyses. Predominant periods of microtremor are considerably lower than estimated fundamental ground periods. It is shown that a small part of the observed differences in due to soil non-linearity in connection with the small strain amplitudes induced by microtremors. The largest part appears to be due to geologic factors, namely the existence of rigid soil layers within the soft soil above the …

Seismic Response Of Deep Soil Profiles In The New Madrid Seismic Zone, William E. Manrod Iii, James E. Beavers, M. Joe Hunt

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Geotechnical and geophysical investigations are being performed at a site which is located within 60 km of the epicenter of the 8.7 magnitude New Madrid February 7, 1812 earthquake. The exploration is being performed to determine the seismic response of the soil profile and to evaluate the liquefaction potential of the site. Permanent downhole instrumentation for seismic monitoring will be installed.

General Report Session 8: Soil Amplification During Earthquakes And Microzonation, J. Carl Stepp

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

Dynamic Considerations In The Design Of Paper Machine Foundations, J. P. Lee

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The design of modern paper machine foundation should consider machine frame supporting foundation and underlying soil as an integrated system. For smooth operation of the machine, quality of paper and economic reasons, a dynamic analysis of the machine system should be performed. This paper discusses three most important factors in the dynamic analysis of a paper machine: (1) Soil-structure interaction effect, (2) frequency analysis, and (3) force-response analysis.

Prediction Of Vibrations Of Footings For Highly Sensitive Devices, Werner Palloks, Werner Heidrich, Stephan Achilles

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

When planning foundations for devices sensitive to vibrations the planned location should be investigated for vibrations. These investigations have to include the existing sources in the vicinity as for instance street or rail traffic as well as exciting devices to be installed at the same building site like compressor stations or other machines. The present paper shows a procedure to estimate the vibrations at the planned locations for sensitive devices. The procedure includes investigations of the dynamic soil properties, the decrease of the vibrations with distance, and the transfer functions of rigid footings. It takes into consideration stochastic excitation as …

Flow Failure Of Liquefied Sand In Large-Scale Shaking Tables, Kenji Ishihara, Mikio Takeuchi

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Laboratory studies on flow failure in liquefied sand deposits using large-scale shaking tables are briefly introduced, together with a case study on the lateral deformation in the field. The key parameters influencing the occurrence of flow-type deformation are discussed in an effort to figure out a mechanism or scenario of the flow failure. In one series of the laboratory studies, shaking table tests were performed to examine the effectiveness of a preventive measure against the flow slide. This aspect is also discussed briefly.

Seismic Amplification In The Presence Of Geological And Topographic Irregularities, E. Faccioli

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

Following some introductory remarks on the key aspects of seismic site effects evaluation and on new data of special interest from recent earthquakes, the first part of the paper discusses and compares the performance of numerical 2D and 1D models, as well as of simple exact solutions, in problems of local soil response and of topographic amplification. The second part is devoted to the illustration of a very promising computational tool, i.e. the Fourier (or pseudo spectral) method, for time-domain analyses of seismic wave propagation in heterogeneous elastic media.

Committees, Multiple Members

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

Index, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

Author And Discussion Index, Multiple Authors

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

No abstract provided.

Cyclic Load Resistance Of Vertically Reinforced Sand Subgrades, Vijay K. Puri, James A. Chae, Braja M. Das

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

This paper presents the results of laboratory scale model footing tests which were conducted for determining the cyclic load resistance of sand subgrades reinforced with semi-flexible vertical elements. The tests were conducted in a sandbox having a length of 91.5 cm, width 15.25 cm, and height of 61.0 cm. Steel bars 1. 58 mm in diameter were used as reinforcing elements. Tests were also conducted by using rough reinforcing elements. The test results indicate that the value of coefficient of elastic uniform compression of the footing on sand increases with the provision of vertical reinforcement in the sand subgrade. Rough …

Degradation Behavior Of Normally Consolidated Clay Under Cyclic Loading Condition, Meei-Ling Lin, Jiang-Yuan Chen

International Conferences on Recent Advances in Geotechnical Earthquake Engineering and Soil Dynamics

The degradation behavior of soil may become important when considering the response of soft clay under cyclic loading condition. A nonlinear model was proposed by Idriss, et al. to account for the degradation behavior based on the controlled-strain test. By adopting a numerical procedure, the data obtained in controlled-stress cyclic triaxial test can be used to find the degradation parameter defined in the nonlinear degradation model proposed by Idriss, et al. A series of consolidated-undrained controlled-stress and controlled-strain cyclic triaxial tests were performed on laboratory manufactured normally consolidated soft clay samples. The relationship between degradation parameter and strain was determined …