Engineering Commons^™

Microwave And Millimeter Wave Signal Generation Using Mode-Locked Semiconductor Lasers With Intra-Waveguide Saturable Absorbers, Dennis J. Derickson, R. J. Helkey, A. Mar, J. G. Wasserbauer, Y. G. Wey, J. E. Bowers

Electrical Engineering

Microwave and millimeter wave signals can be generated using mode-locked semiconductor lasers with intra-waveguide saturable absorbers. Monolithic and external cavity devices optimized for electrical and optical signal generation are discussed along with measurements of amplitude noise, phase noise, output power, and repetition rate tunability.

The Calendar - June 1992, Nova University

The Calendar

No abstract provided.

Micro-Sprinkler And Fan Cooling For Dairy Cows: Practical Design Considerations, Larry W. Turner, Richard C. Warner, John P. Chastain

Agricultural Engineering Extension Publications

Research and on-farm demonstrations have shown that micro-sprinklers, spray jets and fan cooling systems can be effective in relieving heat stress in dairy cows under hot, humid conditions. Based on these results, many dairymen are considering installing sprinkler and fan cooling. Several Kentucky dairymen have already installed sprinkler cooling systems, but they could improve their performance by modifying them to take into account the principles involved and the components used in sprinkler and fan cooling.

The 3-Tier Structured Access Protocol To Control Unfairness In Dqdb Mans, Lakshmana N. Kumar, Andreas D. Bovopoulos

All Computer Science and Engineering Research

This paper addresses the unfairness problem appearing in 802.6-based DQDB MANs. Traffic load demand is characterized as low (below 0.4 of the channel capacity), normal (from 0.4 to 0.9 of the channel capacity) or heavy (greater than 0.9 of the channel capacity). At low loads the 802.6 protocol is acceptably fair. At normal loads, however, the protocol performance is markedly unfair. The unfairness is related to the latency in transporting a request. At heavy loads the unfairness is both latency-related and flooding-related. In this paper, both types of unfairness are carefully analyzed. As a control measure, a 3-Tier Structured Access …

Prediction Of Paper Color: A Process Simulation Approach, Mayank Chaturvedi

Masters Theses

A simulation model was developed for a dye mixing process and for the prediction of the optical properties of the paper. The model was integrated with the MAPPS (Modular Analysis of Pulp and Paper Systems) simulation software package. The model was validated using dyed handsheets made in a laboratory and dyed paper made on a pilot papermachine. Validation comprised of prediction of the optical properties of the handsheets and the machine-made paper which contained various combinations of three non-fluorescent dyes. Sheet reflectances were predicted at 20 nanometer intervals for discrete light wavelength range of 400 to 700 nanometers and verified …

Interface Cavitation Damage In Polycrystalline Copper, Brent L. Adams, David P. Field

Faculty Publications

The authors acknowledge the support of the Office of Basic Energy Sciences of the United States Department of Energy. Determination of an interface damage function (IDF) from a stereological procedure similar to that presented by Hilliard is described. The mathematical and experimental simplicity of the method is utilized in measuring an IDF for polycrystalline copper crept at 0.6T sub m under uniaxial tension. Whereas previous work focused on a five parameter description of the local state of a grain boundary, the domain of the IDF is increased to eight degrees of freedom in the present study to include the complete …

Experimental Measurement Of Rov Tether Tension, Tim W. Mclain, S M. Rock

Faculty Publications

In the undersea operation of a tethered ROV system, the pilot's ability to control precisely the ROV is often limited by disturbance forces generated by drag due to currents that act either directly on the ROV or indirectly on the ROV through the tether. The objective of this research, which was conducted at the Monterey Bay Aquarium Research Institute (MBARI), was to characterize the magnitude and dynamics of tether forces by measuring them during operation. To achieve this, a tether tension sensor and data logging system were developed. This system was used to measure the forces in the tether of …

Non-Linear Finite Element Analysis Of Reinforced Concrete Beams, Wael Mohamed El-Dessouki

Archived Theses and Dissertations

No abstract provided.

A Novel Numerical Technique For Dielectric Measurement Of Generally Lossy Dielectrics, Stoyan I. Ganchev, Sasan Bakhtiari, R. Zoughi

Electrical and Computer Engineering Faculty Research & Creative Works

A method for determining the dielectric properties of infinite half-space of generally lossy dielectric materials is described. This method utilizes the measurement of the admittance of a rectangular waveguide radiating into such dielectrics. It is shown that the real part of the admittance is relatively insensitive to the variations of the imaginary part of the dielectric constant. Subsequently, a numerical procedure is initiated which provides a simple and fast-converging approach for calculating the dielectric properties. This numerical procedure lends itself to implementation by personal computers--a major advantage over the existing computational schemes. The theoretical formulation for the expression of the …

Persistence Of Eggs And Hepatic-Fibrosis After Treatment Of Schistosoma Mansoni-Infected Mice, A. W. Cheever , '82, J. G. Macedonia, S. Deb, Erik Allen Cheever , '82, J. E. Mosimann

Engineering Faculty Works

In 1971 we estimated that Schistosoma mansoni eggs in the tissues of mice were destroyed with an approximate half-life of four weeks. Our present results of five experiments suggest that egg destruction is not as rapid, and no significant destruction of eggs was detected for up to 26 weeks after treatment. However, in these experiments, a mean of 60% of the eggs in intestinal tissues were found in the feces at the time of treatment. In previously reported experiments, only 15% of gut eggs were passed in the feces. We now believe that underestimation of the number of eggs passed …

Fsec 3.0: Florida Software For Enervironment Computation: V3.0 Draft User's Manual. 01-92, Florida Solar Energy Center, Alp Kerestecioglu

FSEC Energy Research Center®

FSEC 3.0 was developed to support research. It is a general-purpose software package especially designed to simulate complex building science problems. The program offers several unique features.

The major feature is its ability to solve user-defined systems of governing equations. Up to 250 coupled differential equations and their corresponding boundary conditions may be either selected from libraries or defined by the user. The equations may be linear or nonlinear; spatially-lumped or spatially-distributed; steady-state or transient; ordinary or partial. The structure of the software also allows users to incorporate their own routines or programs. Thus, researchers may define their specific problem …

Accident Analysis Of Ice Control Operations, David Kuemmel, Rashad Hanbali

Transportation Research Center: Accident Analysis of Ice Control Operations

Highway maintenance involves all work necessary to assure that the highway system is kept safe, open to traffic, and in proper working order. During winter, the removal of snow and ice from streets, roads, and highways is a major maintenance operation. With more than 135 million motor vehicles registered in the United States and roughly four million miles of roads and streets, local governments must be prepared to deal with the removal of snow and ice to insure public safety, and to reduce the adverse impact on the affected area’s economy.

Snow and ice covered roads can paralyze the functioning …

Book Review, Allan M. Wheatcraft

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

Review of the following: LEONARD EVANS, TRAFFIC SAFETY AND THE DRIVER. (Van Nostrand Reinhold 1991) [404 pp.] About the author, author index, figures, notes, preface, subject index, tables. LC 90-44233, ISBN 0-4421-00163-0. [Cloth $51.95. P.O.B. 668, Florence KY 41022-0668.]

A Study Of The Effect Of Water-Soluble Polymers On Water Holding And Binder Migration Tendencies Of Coatings, Joginder S. Malik

Masters Theses

Water-soluble polymers are being used in the paper coating industry for a variety of purposes including the development of water holding, viscosity control, structure and binder migration control. This study was designed to evaluate the degree that selected types of water-soluble polymers (carboxymethylcellulose, hydroxyethylcellulose, sodium alginate, polyvinyl alcohol and a polyacrylate) influence these properties. The methodology comprised of recently developed techniques in which water holding, immobilization solids and binder migration could all be measured for similar coatings applied on a paper-like porous substrate. The results illustrated that watersoluble polymers affect both the water-loss rate and binder migration, but reduce the …

Limaçon Of Pascal Locus Of The Complex Refractive Indices Of Interfaces With Maximally Flat Reflectance-Versus-Angle Curves For Incident Unpolarized Light, R. M.A. Azzam

Electrical Engineering Faculty Publications

For an interface between two isotropic media the power reflectance R_v (ø) is an even function, R_v (ø) = R_v (--), of the angle of incidence ø; hence all the odd derivatives, R_v⁽ⁿ⁾ = dⁿ R_v /døⁿ (n odd), are identically 0 at ø = 0, independent of the incident polarization v. When the incident light is unpolarized (v = u), the second derivative, R_u⁽²⁾, is also 0 at ø = 0, so that the flatness of the R_u -versus-ø curve …

Division-Of-Amplitude Photopolarimeter Based On Conical Diffraction From A Metallic Grating, R. M.A. Azzam

Electrical Engineering Faculty Publications

A new photopolarimeter that employs polarization-dependent conical diffraction of light by a metallic grating for the simultaneous measurement of the four Stokes parameters of light is described.

New In Vivo And In Vitro Techniques For Quantification Of Lateral Force Levels That Cause Implants To Fail : A Progress Report On Monkey Research, V. Leroy Leggitt

Loma Linda University Electronic Theses, Dissertations & Projects

Two new techniques for quantification of forces generated by an expansion screw apparatus placed between pairs of cylindrical endosseous titanium implants are described, along with preliminary data gained from their use in Macaca rhesus monkeys. Strain gages were bonded to the expansion apparatus and were calibrated either directly by micro load cell, or indirectly by Instron Machine to reflect the applied force.

Immediate loads of up to 6 kilograms have been applied to the implants with no increase in mobility as verified by a Periotest device. No previous studies on the orthodontic uses of implants have evaluated in vivo forces …

A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part I: Principles, Jim Mcgovern, Francis O'Toole

Conference Papers

A new type of virtual system, named a flow constraint system (FCS), is proposed to facilitate, clarify, and simplify exergy analyses of plant that involve material flow networks. The need for the virtual system is outlined and the concept is demonstrated by applying it to a CHP steam cycle. The FCS concept allows the physical constraints on the exergy interactions associated with flow streams to be taken into account fully. It also simplifies the treatment of bifurcations in material flows and considerably reduces the need for absolute exergy evaluations. The new concept follows from the work already published by the …

A Virtual-System Concept For Exergy Analysis Of Flow Network Plant; Part Ii: Exergetic And Exergonomic Analysis Illustration, Jim Mcgovern, Francis O'Toole

Conference Papers

This paper is a continuation of Part I — Principles, to which it refers extensively. The virtual system concept and the methodology introduced in Part I are illustrated by means of a numerical example. This is an exergetic and exergoeconomic analysis of the CHP steam plant that was described in Part I without operating values and parameters. Matrix methods developed by Valero et al. (1986) are adapted to the new concept. It is shown that these methods are made simpler and less subjective. Bond-graph-type diagrams for exergetic and economic costs are presented.

Development Of An Analog Mimo Quantitative Feedback Theory (Qft) Cad Package, Richard R. Sating

Theses and Dissertations

This thesis describes the development of an analog MIMO Quantitative Feedback Theory (QFT) CAD package for the automation of the multivariable control design process. The CAD package is capable of carrying a design from problem setup through the design process to a frequency domain analysis of the compensated MIMO system. The package automates the selection of the weighting matrix, formation of the square effective plants, the polynomial matrix inverse required to form the equivalent plants, generation of stability, tracking, disturbance, gamma, and composite bounds, loop shaping, design of the prefilter elements, and the frequency domain analysis of the completed design. …

Neutron Fluence And Dose From A Varian Clinic 1800 Accelerator, Richard A. Jackson

Theses and Dissertations

The goals of this study were (1) to verify calibration factors determined by previous experiment for relating counts from activated gold foils to neutron fluences, and (2) to use the method to determine neutron fluences under various operating conditions of the Varian Clinac 1800 (18-MeV) electron accelerator at the WPAFB Medical Center. For comparison similar measurements were made of the CGM Saturne 1 at Kettering Memorial Hospital, Dayton, Ohio. Cadmium-difference pairs in a standard graphite pile were employed to verify the counting efficiency of the Geiger-Mueller beta counting system used to count the foil activity. They were also used to …

A Method For Determining Schedule Delay Information In A Channel Cargo Route Network Schedule, Justin E. Moul

Theses and Dissertations

This research develops a method for measuring schedule effectiveness by determining the amounts of enroute, cargo delay caused by a given aircraft mission schedule. The method is designed to generate information which helps identify flights for which different scheduling might decrease overall cargo delay in the entire network, given that all non-scheduling factors are held constant. The research uses a simplified twelve-airport cargo route network to test the methodology.

A Modal Analysis And Modelling Of A Lightly Damped Large Space Structure, Scott E. George

Theses and Dissertations

This study involves the modification to the PACOSS Dynamic Test Article to create a lightly damped representative large space structure with closely spaced, low frequency modes. An experimental modal analysis is performed to recharacterize the low frequency flexible vibration modes. A finite element model is created using MSC/NASTRAN to predict low frequency behavior using both real eigenvalue analysis and frequency response analysis. Then a reduced order model is created and fine-tuned to represent the dynamics of the structure for the identified low frequency modes.

Multiple Model Adaptive Estimation Applied To The Vista F-16 With Actuator And Sensor Failures, Timothy E. Menke

Theses and Dissertations

A Multiple Model Adaptive Estimation (MMAE) algorithm is applied to the Variable Stability In-flight Simulator Test Aircraft (VISTA) F-16 at a low dynamic pressure flight condition (0.4 Mach at 20000 ft). A complete F-16 flight control system is modeled containing the longitudinal and lateral-directional axes. Single and dual actuator and sensor failures are simulated including: complete actuator failures, partial actuator failures, complete sensor failures, increased sensor noise, sensor biases, dual complete actuator failures, dual complete sensor failures, and combinations of actuator and sensor failures. Failure scenarios are examined in both maneuvering and straight and level flight conditions. The system performance …

Shear Resistance Of Walls With Steel Studs, K. H. Klippstein, Thomas S. Tarpy Jr.

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

No abstract provided.

Reliability Analysis Of Structural Ceramic Components Using A Three-Parameter Weibull Distribution, Stephen F. Duffy, Lynn M. Powers, Alois Starlinger

Civil and Environmental Engineering Faculty Publications

This paper describes nonlinear regression estimators for the three-parameter Weibull distribution. Issues relating to the bias and invariance associated with these estimators are examined numerically using Monte Carlo simulation methods. The estimators were used to extract parameters from sintered silicon nitride failure data. A reliability analysis was performed on a turbopump blade utilizing the three-parameter Weibull distribution and the estimates from the sintered silicon nitride data.

Introduction To Intellisim 1.0, Paul Savory

Department of Industrial and Management Systems Engineering: Faculty Publications

IntelliSIM is a prototype for a new generation of knowledge-based simulation tool that has been developed by the Systems Simulation Laboratory at Arizona State University. This tool is a computer environment that allows non-simulation trained modelers to predict the performance of a manufacturing system for which the necessary data is available. The system provides predictive data on such items as throughput time, queue levels, equipment utilization, reactions to machine failures, etc. With IntelliSIM, the benefits of discrete-event simulation can be exploited without requiring the high level of expertise necessary to successfully conduct a sound simulation study. The approach offered with …

Review Of Highway Cost Allocation Methodologies, John A. Deacon, Jerry G. Pigman, Nikiforos Stamatiadis

Kentucky Transportation Center Research Report

The objectives of the current cost allocation study, the fifth in a series begun in 1982, include the following: 1) to evaluate current cost allocation methodologies and identify possible changes to Kentucky practices; and 2) to determine the 1991 fiscal year levels of cost responsibility and revenue contribution for each of several classes of highway users. Additional objectives include an evaluation of the equity of tax proposals advanced by the Kentucky Motor Transport Association, a preliminary determination of the revenue and cost implications of the Extended-Weight Coal Haul System, and an evaluation of the efficiency with which certain highway user …

Statistcal Analysis Of Some Parameteres Of Sliver Preparation On It`S Quality, Rizk El-Bealy Associ.Prof

Mansoura Engineering Journal

In the present work, the experimental design technique was used to study the influence of some variables at the processing prior to spinning on the variation of card sliver quality. The variables considerd to be affecting the card sliver quality are as follow: blowroom lines/chute feed arrangement, carding machines were used throughout, days of production and cotton fibers. A statistical analysis were made of the sliver parameters, its size, count variations neps per gram and sliver irregularity, using three factor analysis of variance. The results declared that the chosen variables and interactions had a large influence on the sliver quality …

Investigation Of Waterjet-Workpiece Interaction, Hung-Yuan Li

Dissertations

The objective of this research is to develop new knowledge related to the fundamental physical phenomena of waterjet machining of ductile materials, and to use this knowledge to construct a numerical analysis model. The resulting knowledge will enable enhancement of waterjet cutting efficiency.

Experimental study of fundamental mechanisms and the acquisition of the data detailing micro and macro scale phenomena which occur during the machining process is carried out. It is shown that the material damage mechanism associated with waterjet machining is erosion cavitation which initiates ultrasonic stress wave propagation in the workpiece. Fatigue, an important element in producing material …