Engineering Commons^™

Fabrication, Structure, Properties And Workability Of Al 2024/Sic Particulate Composites, Renee Naim Aziz

Archived Theses and Dissertations

[abstract not provided]

Identifying An Emi Source And Coupling Path In A Computer System With Sub-Module Testing, S. Radu, Yun Ji, Joe Nuebel, James L. Drewniak, Thomas Van Doren, Todd H. Hubing

Electrical and Computer Engineering Faculty Research & Creative Works

EMI in a workstation server resulting from CPU clock harmonics was investigated. Mechanisms by which noise is coupled off the CPU PCB module were diagnosed from studies and measurements on the CPU PCB alone. A model was then developed. Modifications were made and tested in the fully functional system to support the model.

Investigation Of Internal Partitioning In Metallic Enclosures For Emi Control, S. Radu, Min Li, Joe Nuebel, David M. Hockanson, Yun Ji, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

High clock frequencies and short-edge rates in present high-speed digital systems result in EMI problems at increasingly higher frequencies. At these speeds, clock harmonics have sufficient energy in the range above 500 MHz to excite cavity modes of a conducting enclosure, and to drive even small length slots and apertures that are unavoidable in a practical design, and can result in an EMI problem. One approach to mitigate these problems is to partition the enclosure into several smaller internal shielded compartments. To study the factors which affect this partitioning, a special enclosure that can be divided into two internal compartments …

Effects Of Gapped Groundplanes And Guard Traces On Radiated Emi, D. S. Britt, David M. Hockanson, Fei Sha, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Designers sometimes employ gapped reference planes to isolate analog and digital signals, and separate "quiet" and "noisy" ground structures by providing a series impedance. Guard traces are also used to reduce unwanted coupling to adjacent traces, which can lead to signal integrity or EMI problems. This study investigates the impact of gaps and guard traces on radiated EMI. A simple microstrip circuit was constructed to experimentally analyze the effects of groundplane gaps and guard traces.

Numerical And Experimental Corroboration Of An Fdtd Thin-Slot Model For Slots Near Corners Of Shielding Enclosures, Min Li, Kuang-Ping Ma, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Simple design maxims to restrict slot dimensions in enclosure designs below a half-wave length are not always adequate for minimizing electromagnetic interference (EMI). Complex interactions between cavity modes, sources, and slots can result in appreciable radiation through nonresonant length slots. The finite-difference time domain (FDTD) method can be employed to pursue these issues with adequate modeling of thin slots. Subcellular FDTD algorithms for modeling thin slots in conductors have previously been developed. One algorithm based on a quasistatic approximation has been shown to agree well with experimental results for thin slots in planes. This FDTD thin-slot algorithm is compared herein …

Guide To Revenue Calculations: Local Option Highway User Tax 1997, Jon D. Fricker

Indiana Local Technical Assistance Program (LTAP) Publications

This guide is provided to explain the output generated by the computer programs, and to suggest ways in which the results can be adapted to specific LOHUT proposals before a County Council. HERPICC neither endorses nor opposes passage of a LOHUT. The revenue projections it provides are intended to be an aid to well-informed decision-making on the part of a county’s citizens and its County Council.

Flow Due To A Moving Pressure Distribution Over Free-Surface With Finite-Depth Bottom, Noriaki Okita

Masters Theses

Two-dimensional, steady-state and time-dependent analysis of wave making phenomenon due to a moving pressure distribution in sub-critical Froude number was performed. The domain is consisted of undisturbed free-surface at y=0, flat bottom at y=-h, and it is unbounded in horizontal direction. The pressure distribution was treated as an ideal model of an air-cushioned-vehicle (ACV). Ideal flow theory and linearized boundary conditions were used. Numerical integration algorithm was developed to evaluate the analytical solution. The surface elevation, bottom pressure profiles, and wave resistance were analyzed as functions of speed and depth.

The steady-state wave resistance calculated from the surface elevation profile …

Performance Of An Air Conditioning System Using R-134a As A Refrigerant, Abdelrahman I Elsherbini

Archived Theses and Dissertations

No abstract provided.

Fabrication, Structure, Properties And Workability Of Al 2024/Sic Particulate Composites, Renee Naim Aziz

Archived Theses and Dissertations

No abstract provided.

Singular And Plural Non-Deterministic Parameters, Sigurd Meldal, M. A. Walicki

Faculty Publications

The article defines algebraic semantics of singular (call-time-choice) and plural (run-time-choice) nondeterministic parameter passing and presents a specification language in which operations with both kinds of parameters can be defined simultaneously. Sound and complete calculi for both semantics are introduced. We study the relations between the two semantics and point out that axioms for operations with plural arguments may be considered as axiom schemata for operations with singular arguments.

A Guide For Designing With Standing Seam Roof Panels, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

Lumped-Element Sections For Modeling Coupling Between High-Speed Digital And I/O Lines, Wei Cui, Hao Shi, Xiao Luo, Fei Sha, James L. Drewniak, Thomas Van Doren, T. Anderson

Electrical and Computer Engineering Faculty Research & Creative Works

Lumped-element sections are used for modeling coupling between high-speed digital and I/O lines on printed circuit boards (PCBs) in this paper. Radiated electromagnetic interference (EMI) is investigated when the I/O line going off the board is driven as an unintentional, but effective antenna. Simulated results are compared with measurements for coupled lines. A suitable number of lumped-element sections for modeling is chosen based on the line length and the highest frequency of interest.

An Expert System For Predicting Radiated Emi From Pcb's, Navin Kashyap, Todd H. Hubing, James L. Drewniak, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

This paper describes an expert systems approach, based on symbolic reasoning techniques, to the problem of predicting radiated EMI levels from printed circuit boards. The expert system, currently under development at the University of Missouri-Rolla, USA, starts by extracting board geometry information from the board layout files. This information is fed into the classification algorithm, which determines the signal properties and nature of each net, using the knowledge stored in the knowledge base. The evaluation algorithm uses the available in formation to identify and evaluate critical circuit geometries, and then estimates the effect that these geometries have on system radiation …

Investigation Of Split Groundplanes At The Connector For Emi Control, David M. Hockanson, James L. Drewniak, Joe Nuebel, James C. Parker Jr.

Electrical and Computer Engineering Faculty Research & Creative Works

EMI can often be reduced by selectively filtering various parts of a given system. One common method employed by designers is to split the groundplane near the chassis and route I/O lines over the split. The rationale is based on providing a large series impedance to common-mode currents on the I/O lines. In this manner, PCB designers hope to lower the level of noise currents contributing to radiation. This work studies the efficacy of the groundplane split as a deterrent for EMI associated with I/O lines being driven against other extended reference structures. A test-board was developed to analyze the …

Evaluation Of Pavement Edge Drains And Headwalls On I-264 (Watterson Expressway) Jefferson County, L. John Fleckenstein, Brad W. Rister, David L. Allen

Kentucky Transportation Center Research Report

This report documents the findings from the investigation of pavement edge drains and headwall conditions on six Watterson Expressway Projects in Jefferson County. These projects include the Newburg Road Interchange, Bardstown Road Interchange, Taylorsville Road Interchange, Breckinridge Road Interchange, l-64 1nterchange, and Shelbyville Road Interchange. The study was initiated due to an on-site inspection by Federal Highway Administration, Kentucky Transportation Center, and District 5 personnel who indicated several of the outlet pipes were clogged or collapsed. It was suggested by Federal Highway Administration personnel that a mini pipeline inspection camera be used to verify the conditions of the outlet pipes …

Ccfss News August 1997, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Emi From Apertures At Enclosure Cavity Mode Resonances, Min Li, Yun Ji, S. Radu, Joe Nuebel, Wei Cui, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

EMI from slots and apertures resulting from coupling of interior sources through enclosure cavity modes in a Sun S-1000 workstation was investigated. The excitation of a specially designed rectangular enclosure with a slot was also studied experimentally and with finite-difference time-domain (FDTD) simulations. The radiated power results for both the S-1000 and simple rectangular enclosure indicate that radiation at cavity mode resonance frequencies through slots and apertures can be as significant as at aperture or slot resonances. A decrease of the radiation through the slots and apertures can be achieved by employing a lossy material in the enclosure.

An Improved Analytical Model For Wormhole Routed Networks With Application To Butterfly Fat-Trees, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

A performance model for wormhole routed interconnection networks is presented and applied to the butterfly fat-tree network. Experimental results agree very closely over a wide range of load rate. Novel aspects of the model, leading to accurate and simple performance predictions, include (1) use of multiple-server queues, and (2) a general method of correcting queuing results based on Poisson arrivals to apply to wormhole routing. These ideas can also be applied to other networks.

Experimental Investigation Of Nonlinear Dynamics In Single Mode Semiconductor Laser Diodes With Phase Conjugate Feedback, Gordon T. Hengst

Theses and Dissertations

The semiconductor laser diode offers a unique system to investigate nonlinear dynamics when optical feedback is applied. Although there is extensive research of laser diodes with optical feedback from normal dielectric mirrors, very little has been done experimentally to analyze the effects of degenerate phase conjugate feedback from a BaTiO₃ crystal. This research experimentally investigated the dynamics of a single-mode laser diode with weak phase conjugate feedback using both the self-pumped and double phase conjugate geometries. The experimental results validated a mathematical model which numerically evaluates the Lang-Kobayahsi coupled differential equations. The model simulated the nonlinear behavior of a …

Plasticized, Antiplasticized And Crystalline Conducting Polymers, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Funded Proposals

Materials containing precursors to electrically conductive polymers and electrically conductive polymers are described which have a high degree of crystallinity. The high degree of crystallinity is achieved by preparing the materials under conditions which provide a high degree of mobility to the polymer molecules permitting them to associate with one another to form a crystalline state. High levels of electrical conductivity are achieved in in the electrically conductive materials without stretch orienting the material. The enhanced electrical conductivity is isotropic as compared to a stretch oriented film which has isotropic electrical conductivity.

Strip Casting With Fluxing Agent Applied To Casting Roll, Robert S. Williams, Ronald J. O'Malley, Richard C. Sussman

Materials Science and Engineering Faculty Research & Creative Works

A strip caster (10) for producing a continuous strip (24) includes a tundish (12) for containing a melt (14), a pair of horizontally disposed water cooled casting rolls (22) and devices (29) for electrostatically coating the outer peripheral chill surfaces (44) of the casting rolls with a powder flux material (56). The casting rolls are juxtaposed relative to one another for forming a pouting basin (18) for receiving the melt through a teeming tube (16) thereby establishing a meniscus (20) between the rolls for forming the strip. The melt is protected from the outside air by a non-oxidizing gas passed …

Model Discrimination And Estimation Of The Intraparticle Mass Transfer Parameters For The Adsorption Of Bovine Serum Albumin Onto Porous Adsorbent Particles By The Use Of Experimental Frontal Analysis Data, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experimental data from a chromatographic system involving the adsorption of bovine serum albumin (BSA) onto porous anion-exchange adsorbent particles packed in a column are presented. The parameters that characterize the mass transfer mechanisms of intraparticle diffusion and convection are estimated by fitting the predictions of dynamic mathematical models describing adsorption in column systems having spherical perfusive and purely diffusive adsorbent Particles to the experimental breakthrough data obtained from the column adsorption system. Both linear and nonlinear expressions for the equilibrium isotherm are considered. The values of the transport parameters are estimated in the time domain for the nonlinear adsorption models …

Accumulation Of Lead By Anabaena Cylindrica: Mathematical Modeling And An Energy Dispersive X-Ray Study, David T. Swift, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

The ability of microorganisms to selectively adsorb various heavy metal ions has been recognized for over a decade. We have investigated the biosorption of lead by an active culture of the cyanobacterium Anabaena cylindrica. Energy dispersive X-ray microanalysis was used to evaluate the different uptake mechanisms in the various subcellular regions. Three were identified; a very fast adsorption mechanism in the cell envelope; a time- dependent deposition reaction on the cell surface; and an adsorption mechanism, also time dependent, on the polyphosphate body inside the cell. Atomic absorption spectrometry was then used to quantify the changes with time of bulk …

Trends. Political Psychology In Space: Diagnostic Issues, Ibpp Editor

International Bulletin of Political Psychology

The author discusses the nomenclature, standards, and criteria are most optimal to evaluate space station personnel.

Moving Mountains With Good Research - A Case Study, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

Mountains can be moved by good ideas based on good research. A wonderful example comes to us from, of all things, the Naval Facilities Command (NAVFAC), headquartered in Washington, DC. This agency of the Department of Defense is responsible for some $5 billion per year in new and retrofit construction, with naval facilities all over the globe. The federal government alone is responsible for $50 billion per year of construction, which Terry Emmons of NAVFAC claims is half of total U.S. construction. It seems that the Navy has 120,000 buildings around the world, some buildings, or groupings, are the size …

Batteries And Charge Control In Stand-Alone Photovoltaic Systems, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This report presents fundamentals of battery technology and charge control strategies commonly used in stand-alone photovoltaic (PV) systems. This work is a compilation of information from several sources, including PV system design manuals, research reports and data from component manufacturers.

Details are provided about the common types of flooded lead-acid, valve regulated lead-acid, and nickel cadmium cells used in PV systems, including their design and construction, electrochemistry and operational performance characteristics. Comparisons are given for various battery technologies, and considerations for battery subsystem design, auxiliary systems, maintenance and safety are discussed.

Requirements for battery charge control in stand-alone PV systems …

Studying Initiation And Growth Of Shear Cracks In Reinforced Concrete Beams Using Full-Field Digital Imaging, Daniel C. Jansen, Sokhwan Choi, Surendra P. Shah

Civil and Environmental Engineering

The mechanisms which lead to shear failure of longitudinally reinforced concrete beams are complex and often misunderstood. In this paper, a combination of a special closed loop test technique and machine vision are applied to tests on two reinforced concrete beams failing in shear: one made of normal strength concrete and the second of high strength concrete. To control the progression of the shear crack, a closed-loop test technique was devised and employed such that the crack propagation was stable even during the post peak. To locate the crack and to measure the crack displacements, machine vision, a nondestructive measuring …

Needs Assessment For Applying Photovoltaics To Disaster Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

When disaster strikes, such as a hurricane, flood, tornado, or earthquake, it can leave many people without adequate medical services, portable water, electrical service and communications. It can be as destructive as Hurricane Andrew, which left several hundred-thousand people homeless. Those fortunate enough to survive the disaster could be without local utility power and other services for long periods of time as services are restored.

When such disasters occur, emergency management teams, the military, and many public and private organizations respond with massive relief efforts. Dependency on electrical utility power becomes pronounced as emergency services are rendered and rebuilding begins. …

Trends. Supercomputer Sales And Nuclear Proliferation: The Surrealist Top Ten, Ibpp Editor

International Bulletin of Political Psychology

The author discusses supercomputers in conjunction with nuclear weapons.

Detection Of Volcanic Ash Clouds From Nimbus 7/Total Ozone Mapping Spectrometer, C. J. Seftor, N. C. Hsu, J. R. Herman, P. K. Bhartia, O. Torres, William I. Rose, David J. Schneider, N. Krotkov

Department of Geological and Mining Engineering and Sciences Publications

Measured radiances from the Version 7 reprocessing of the Nimbus 7/total ozone mapping spectrometer (TOMS) 340- and 380-nm channels are used to detect absorbing particulates injected into the atmosphere after the El Chichon eruption on April 4, 1982. It is shown that while the single-channel reflectivity determined from the 380-nm channel is able to detect clouds and haze composed of nonabsorbing aerosols, the spectral contrast between the 340- and 380-nm channels is sensitive to absorbing particulates such as volcanic ash, desert dust, or smoke from biomass burning. In this paper the spectral contrast between these two channels is used to …