Engineering Commons^™

A Study Of Numerical Integration Techniques For Use In The Companion Circult Method Of Transient Circuit Analysis, Charles A. Thompson

Department of Electrical and Computer Engineering Technical Reports

Circuit transient analysis packages such as SPICE and EMTP are very widely used, but detailed information on the internal structure and error characteristics for these software packages is lacking. Both SPICE and EMTP rely on numerical integration to approximate the transient response of circuit elements. The numerical integration methods used in the packages are not necessarily the most accurate approximations to the actual response of a circuit. The study of these numerical integration methods and their error characteristics is the focus of this thesis. Comparisons are made between several methods in terms of accuracy and stability as well as algorithm …

An Investigation Of Cutting Tool Chatter Vibration In Machine Tools, Arneil Olson

Graduate Research Papers

The purpose of this study was to assemble and condense the research and background literature available on cutting tool chatter vibration. Another requirement was to translate the highly technical language of the researcher into a form readily understandable to shop floor personnel.

Support staff called upon to assist in the elimination of chatter problems have not been given the informational resources necessary to effectively deal with the phenomenon. This information should be gathered from university libraries and cutting tool experts and combined into one basic reference work.

If collecting the references were all that was required they could simply be …

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 …

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 …

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.

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, …

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.

Kentucky Rock Asphalt (Kyrock) Road Surfacing Material: Preliminary Investigation, Jerry G. Rose

Kentucky Transportation Center Research Report

This report documents a preliminary investigation of Kentucky Rock Asphalt (Kyrock) - as a road surfacing material. The indigenous bituminous impregnated sandstone was widely used as a premium quality skid resistant surfacing material during the first half of this century. Redevelopment efforts gained momentum during the 1960's, but for the last twenty years interest has waned.

Laboratory tests were conducted on the Kyrock to determine its applicability in bituminous surface mixes by blending Kyrock with virgin materials in a similar manner as adding recycled asphalt pavement. The findings indicated it was feasible to blend Kyrock and a continuation proposal was …

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 …

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 …

Achieving A Given Reflectance For Unpolarized Light By Controlling The Incidence Angle And The Thickness Of A Transparent Thin Film On An Absorbing Substrate: Application To Energy Equipartition In The Four-Detector Photopolarimeter, R. M.A. Azzam, Kurt A. Giardina

Electrical Engineering Faculty Publications

At a given wavelength λ we determine all possible solution pairs (ϕ, ζ) of the incidence angle ϕ and the thickness ζ of a transparent thin film on an absorbing substrate that achieve a given unpolarized light reflectance R_u. The trajectory of the point that represents a solution pair in the ζ, ϕ plane depends on the optical properties of the film and substrate and on whether R_u is greater than or less than the normal-incidence reflectance -R₀ of the bare substrate. When R_u > - R₀, the specified reflectance is achieved over a …

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 …

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 …

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 …

Finding A Maximum-Density Planar Subset Of A Set Of Nets In A Channel, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

We present efficient algorithms to find a maximum-density planar subset of n 2-pin nets in a channel. The simplest approach is to make repeated usage of Supowit's dynamic programming algorithm for finding a maximum-size planar subset, which leads to O(n^3) time to find a maximum-density planar subset. But we also provide an algorithm whose running time is dependent on other problem parameters and is often more efficient. A simple bound on the running time of this algorithm is O(nlgn+n(t+1)w), where t is the number of two-sided nets, and w is the number of nets in the output. Though the worst-case …

Network Analysis Of Intermediary Metabolism Using Linear Optimization. I. Development Of Mathematical Formalism, Joanne M. (Savinell) Belovich, Bernhard O. Palsson

Chemical & Biomedical Engineering Faculty Publications

Analysis of metabolic networks using linear optimization theory allows one to quantify and understand the limitations imposed on the cell by its metabolic stoichiometry, and to understand how the flux through each pathway influences the overall behavior of metabolism. A stoichiometric matrix accounting for the major pathways involved in energy and mass transformations in the cell was used in our analysis. The auxiliary parameters of linear optimization, the so-called shadow prices, identify the intermediates and cofactors that cause the growth to be limited on each nutrient. This formalism was used to examine how well the cell balances its needs for …

Network Analysis Of Intermediary Metabolism Using Linear Optimization. Ii. Interpretation Of Hybridoma Cell Metabolism, Joanne M. Savinell (Belovich), Bernhard O. Palsson

Chemical & Biomedical Engineering Faculty Publications

Analysis of metabolic networks using linear optimization theory allows one to quantify and understand the limitations imposed on the cell by its metabolic stoichiometry, and to understand how the flux through each pathway influences the overall behavior of metabolism. A stoichiometric matrix accounting for the major pathways involved in energy and mass transformations in the cell was used in our analysis. The auxiliary parameters of linear optimization, the so-called shadow prices, identify the intermediates and cofactors that cause the growth to be limited on each nutrient. This formalism was used to examine how well the cell balances its needs for …

Test Methods For Mechanically Fastened Cold-Formed Steel Connections, Committee On Specifications For The Design Of Cold-Formed Steel Structural Members

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

No abstract provided.

Ccfss Technical Bulletin February 1992, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Acuta Enews February 1992, Vol. 21, No. 2

ACUTA Newsletters

In This Issue

Call for RD Nominations

President's column

Workshop announcement

Alabama college takes case to PSC

Party Line

Rating to Tucson seminars

Ccfss News February 1992, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Effect Of Co2 On The Processing Of Y-Ba-Cu-O Superconductors, C. Zhang, Guna S. Selvaduray

Faculty Publications

The superconducting properties of YBa2Cu3O6+x reacted with various known ratios of O2/CO2 gas mixtures during sintering at different temperatures were studied. Jc was found to decrease drastically upon reaction with CO2, becoming zero at certain CO2 activities. The stability region for the 123 superconductor, as a function of CO2 activity and temperature, was empirically formulated as follows: log pCO2 < (−45,000)/T + 33.4. The grain boundaries in sintered samples with Jc = 0 were investigated with HRTEM in conjunction with EDS. Two distinct types of grain boundaries were observed. Approximately 10% of the grain boundaries were wet by a thin layer of a second phase, deduced to be BaCuO2. The remaining boundaries were sharp grain boundaries. The grain structure near the sharp grain boundaries was tetragonal. These two types of grain boundaries are thought to be responsible for Jc being zero.