Engineering Commons^™

Motorized Insulated Damper Assembly For Furnace Systems, William Max Kirk, Timothy Wentz

Durham School of Architectural Engineering and Construction: Faculty Publications

A damper unit is provided that is adapted to be positioned in a furnace duct line. The damper unit has a housing which is in communication with a fresh air source and a furnace system. The housing has a damper blade which is moveable between an open position which allows air flow through the housing and a closed position which prevents air flow through the housing. The blade is coupled with a Solenoid so that when the Solenoid is activated the blade is moved to an open position allowing air flow through the housing. Further, a fan is located in …

Mechanism Of Radio-Frequency Current Collapse In Gan-Algan Field-Effect Transistors, A. Tarakji, Grigory Simin, N. Ilinskaya, X. Hu, A. Kumar, A. Koudymov, J. Yang, M. Asif Khan, M. S. Shur, R. Gaska

Faculty Publications

The mechanism of radio-frequency current collapse in GaN–AlGaN heterojunctionfield-effect transistors(HFETs) was investigated using a comparative study of HFET and metal–oxide–semiconductor HFET current–voltage (I–V) and transfer characteristics under dc and short-pulsed voltage biasing. Significant current collapse occurs when the gate voltage is pulsed, whereas under drain pulsing the I–V curves are close to those in steady-state conditions. Contrary to previous reports, we conclude that the transverse electric field across the wide-band-gap barrier layer separating the gate and the channel rather than the gate or surface leakage currents or high-field effects in the gate–drain spacing is responsible for the current collapse. We …

Determination Of An Ethane Intermolecular Potential Model For Use In Molecular Simulations From Ab Initio Calculations, Richard L. Rowley, Tapani A. Pakkanen, Yan Yang

Faculty Publications

Counterpoise-corrected, supermolecule, ab initio energies obtained at the MP2/6-311+G(3df, 2pd) level were computed for 22 different relative orientations of two ethane molecules as a function of the separation distance between the molecular centers. These energies were used to regress the parameters in several simple, analytical, interatomic or site-site models that can be used for implementation in molecular simulations. Sensitivity analysis indicated that the inter molecular potential surface is insensitive to the C-C interactions and that the parameters in the C-C model are coupled and unobtainable from the dimer energies. Representation of the potential surface can be made in terms of …

A Comparative Analysis Of Studies On Heat Transfer And Fluid Flow In Microchannels, Choondal B. Sobhan, Suresh V. Garimella

CTRC Research Publications

The extremely high rates of heat transfer obtained by employing microchannels makes them an attractive alternative to conventional methods of heat dissipation, especially in applications related to the cooling of microelectronics. A compilation and analysis of the results from investigations on fluid flow and heat transfer in micro- and mini-channels and microtubes in the literature is presented in this review, with a special emphasis on quantitative experimental results and theoretical predictions. Anomalies and deviations from the behavior expected for conventional channels, both in terms of the frictional and heat transfer characteristics, are discussed.

Student Space Systems Program At Stanford Univerity: The Aerospace Corporation, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Student Space Systems Program At Stanford Univerity: The Aerospace Corporation" from April 6, 2001.

Trends. The Ghost In The Machine: Is Bill Clinton Running Us Policy On China, Ibpp Editor

International Bulletin of Political Psychology

This article discusses aviation safety and the continuity of use/misuse of words by U.S. administrations, regardless of political affiliation.

Multiple Differential Pair Transitor Architecture Having Transconductance Proportional To Bias Current For Any Transitor Technology, Vladimir I. Prodanov

Electrical Engineering

A multiple differential pair circuit is disclosed having a transconductance, g_m, proportional to the bias current, I₀, for any transistor technology. The transistors utilized to construct each of the differential transistor pairs in a multiple differential pair circuit operate in a non-exponential voltage-current (V-I) region. As multiple differential pair circuits are linearized, the effective transconductance, g_m, becomes (i) linearly dependent on bias current, and (ii) insensitive to the voltage-current (V-I) characteristics of the utilized devices. Methods and apparatus are disclosed that provide a linear transconductance, g_m, with respect to the bias current, …

Polycrystalline Conducting Polymers And Precursors Thereof Having Adjustable Morphology And Properties, Ravi F. Saraf

Department of Chemical and Biomolecular Engineering: Patents

Polycrystalline materials containing crystallites of precursors to electrically conductive polymers and electrically conductive polymers are described which have an adjustable high degree of crystallinity. The intersticial regions between the crystallites contains amorphous material containing precursors to electrically conductive polymers and /or electrically conductive polymers. The 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. This is preferable achieved by including additives, such as plasticizers and diluents, to the solution from which the polycrystalline material is …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 7, April 2001, 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.

Cultivating Graduate Students: Techniques To Inspire Effective Research, David Braun, Linda Vanasupa, Blair London, Kevin Kingsbury, Heather Smith

Electrical Engineering

Each year, U.S. institutions grant well over 10,000 bachelor's degrees in science and engineering. However, only a small fraction of those students pursue graduate study. Many who do often experience great difficulty partly due to a lack of preparation for research: the nature of research is inherently foreign to those who are accustomed to studying course material and demonstrating their mastery of it by passing an exam. Carefully involving undergraduates in research can be an effective means for inspiring students to pursue graduate study. We have found that one can create a positive research experience for the student by implementing …

The Airline Quality Rating 2001, Brent D. Bowen, Dean Headley, Uno Aviation Institute

Faculty Books and Monographs

UNOAI Report 01-2

The Airline Quality Rating (AQR) was developed and first announced in early 1991 as an objective method of comparing airline quality on combined multiple performance criteria. This current report, Airline Quality Rating 2001, reflects monthly Airline Quality Rating scores for 2000. AQR scores for the calendar year 2000 are based on 15 elements that focus on airline performance areas important to air travel consumers.

The Airline Quality Rating 2001 is a summary of month-by-month quality ratings for the ten major U.S. airlines operating during 2000. Using the Airline Quality Rating system of weighted averages and monthly performance …

Ground Movement Associated With Microtunneling, Zhenyang Duan

Doctoral Dissertations

Microtunneling is a trenchless technology for construction of pipelines. Its process is a cyclic pipe jacking operation. Microtunneling has been typically used for gravity sewer systems in urban areas. Despite its good success record overall, several large ground settlement cases caused by microtunneling have been reported. Also, in contrast with large diameter urban tunneling, there are few research projects about the ground settlement caused by microtunneling.

In this dissertation, the ground settlement caused by microtunneling is studied using a theoretical approach, empirical approach, numerical simulation approach, and artificial intelligence approach.

In the theoretical approach, the equivalent ground loss and settlement …

Santa Clara Magazine, Volume 42 Number 4, Spring 2001, Santa Clara University

Santa Clara Magazine

3 - EL SOL SHINED IN 1968 STUDENT ELECTIONS By Adam Breen. During the 1968 campus elections, an electrical engineering student felt the student body was too apathetic, so he ran for dictator to spur interest. He could have been king, but instead had himself "assassinated " for a greater cause.

12 - DOUBLE LIVES By Susan Vogel. An economic boom in Silicon Valley created opportunities, jobs, and wealth-but those who work here often can't afford to live here. What are employees and employers doing about it?

16 - THE GLACIER PRIEST By Jeff Kunkel. Bernard Hubbard, S.J., was more …

Evaluation Of 135- And 150-Degree Sliding Hip Screws, Kelly Blayne Crittenden

Doctoral Dissertations

Sliding hip screws are routinely used to repair Garden III femoral neck factures. This research seeks to better understand the influence of the hip screw angle on the performance of the fixation. The mechanics of fractured femurs repaired with 135- and 150-degree sliding fixation devices are explored using experimental, finite element, and analytical modeling. The experimental study involves testing of both intact and fixated femurs; the finite element work centers on two-dimensional models of intact and fixated femurs; and the analytical modeling explores the forces, moments and stresses in the fixation. The analytical model predicts that the screw will serve …

Which Truth Values In Fuzzy Logics Are Definable?, Hung T. Nguyen, Vladik Kreinovich, Antonio Di Nola

Departmental Technical Reports (CS)

In fuzzy logic, every word or phrase describing uncertainty is represented by a real number from the interval [0,1]. There are only denumerable many words and phrases, and continuum many real numbers; thus, not every real number corresponds to some commonsense degree of uncertainty. In this paper, for several fuzzy logic, we describe which numbers are describing such degrees, i.e., in mathematical terms, which real numbers are definable in the corresponding fuzzy logic.

28th Conference On Senior Engineering Design Projects, Western Michigan University

Senior Engineering Design Conference

The 28th Conference on Senior Engineering Design Projects was held on April 10, 2001 at the College of Engineering and applied Sciences on the Parkview Campus of Western Michigan University. The college sponsors the conference to showcase the work of its graduating seniors, who are required to complete a capstone project that puts into practice what they have learned. Many of the projects are sponsored by business and industry.

Generation Of Oxygen Microbubbles In A Microchannel With Crosscurrent Liquid Flow, Sung Sam Kim

Doctoral Dissertations

An alternative way of blood oxygenation is proposed by introducing small bubbles directly into the blood stream. To be used for blood oxygenation, the bubble should be small enough to pass through the capillary beds. To explore the feasibility of producing small bubbles, bubble formation phenomena in a crosscurrent liquid flow in a silicon microchannel were studied. Small orifices with 4 μm, 4.2 μm, and 6.6 μm hydraulic diameter were machined in a direction perpendicular to a trapezoidal channel that has a hydraulic diameter of 42 micrometers. These orifices were connected to three different chambers of 2.5 × 10−7 cm3, …

Structural Distress Condition Modeling For Sanitary Sewers, Vani Samyuktha Kathula

Doctoral Dissertations

Sewers represent a very substantial and crucial part of our underground infrastructure and a high level of investment is needed to maintain them. Sewers are generally out of sight and, as long as they continued to function reasonably well, they are also out of mind—that is, until any problems such as structural, hydraulic and functional arise. The criticality of any sewer condition is a combination of the risk of failure and the consequences of it. Therefore, a systematic approach is necessary to fully understand and evaluate the conditions of this underground infrastructure. The present state of the art does not …

Computational Complexity Of Planning With Temporal Goals, Chitta Baral, Vladik Kreinovich, Raul A. Trejo

Departmental Technical Reports (CS)

In the last decade, there has been several studies on the computational complexity of planning. These studies normally assume that the goal of planning is to make a certain fluent true after the sequence of actions. In many real-life planning problems, the goal is represented in a much more complicated temporal form: e.g., in addition to having a desired fluent true at the end, we may want to keep certain fluents true at all times. In this paper, we study the complexity of planning for such temporal goals. We show that for goals expressible in Linear Temporal Logic, planning has …

Solving Nonlinear Aeronautical Problems Using The Carleman Linearization Method, Brian William Gaude

Master's Theses - Daytona Beach

Many problems in aeronautics can be described in terms of nonlinear systems of equations. Carleman developed a technique to linearize such equations that could lead to analytical solutions of nonlinear problems. Nonlinear problems are difficult to solve in closed form and therefore the construction of such solutions is usually nontrivial. This thesis will apply the Carleman linearization technique to three model problems: a two-degree of-freedom (2DOF) ballistic trajectory, Blasius' boundary layer, and Van der Pol's equation and evaluate how well the technique can adequately approximate the solutions of these ordinary differential equations.

Optimization Of Flow Quality In The Test Section Of The 30-Inch X 40- Inch Subsonic Tunnel, Ahmed F. Elnenaey

Master's Theses - Daytona Beach

The purpose of this study is to optimize the flow quality inside the 30-inch x 40-inch subsonic wind tunnel. The tunnel is an open circuit with its inlet positioned adjacent to the side door of the lab; forcing the air to make a ninety degrees turn entering the tunnel. The flow suffered from two main deficiencies, high level of turbulence and slightly unsteady flow with a non-uniform velocity distribution across the test section. By utilizing a hot-film anemometer system and a total pressure rake, turbulence and velocity distribution data were obtained. Rounded corners and a turning vane were installed in …

The Role Of Eeg Biofeedback Training Preceding An Automated Monitoring Task, Matthew Bernd Hilscher

Master's Theses - Daytona Beach

Discussions are taking place in aviation circles to revamp and revolutionize air traffic management under the term "free-flight". The plans for a new system would incorporate, to a high degree, automation technologies that may have important human factors implications. One such concern speaks to quality of mental involvement as authority roles change. This modification of cerebral involvement may have an effect on performance during critical system failures. The purpose of this research has been to investigate whether specialized EEG biofeedback training might have an ameliorating effect on reducing the vigilance decrement. Partial support was found that evidences utility to this …

Nebraska Blueprint - Spring 2001

Nebraska Blueprint (Student Publication)

Table of Contents:

From the Editor
Students uncover the secrets of the Magic Kingdom
Student Life on the Sixth Floor
Celebrating National Engineers Week at PKI
NSBE lights its torch at UNL
Undergraduates benefit from conducting research
Postcard from Paris
Out of the starting blocks

Destructive And Non-Destructive Testing Of Bridge J857 Phelps County, Missouri : Strengthening And Testing To Failure Of Bridge Piers, Tarek Alkhrdaji, Antonio Nanni, Genda Chen

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Many of the existing reinforced concrete (RC) bridge piers constructed in the first half of this century were designed as gravity piers with minimal flexural reinforcement and no consideration to seismically induced lateral forces. When considered in earlier designs, the seismic lateral forces were typically low. The potential risk of failure of columns on these piers under a moderate earthquake is becoming a growing concern for the transportation management agencies. In addition, flexural strength deficiency in RC columns may arise from the loss of reinforcement due to corrosion, premature termination of the main reinforcement, or inadequate splicing. One method for …

Maximum Acceptable Oral Reading Speed For Voice Input Systems, Nirari M. Oda

Masters Theses

The objective of this thesis was to study the effect of vocal duration period and background noise on psychophysical oral reading speed. Ten healthy white males (21-28 years old) were used as subjects. Experiment one was designed to determine Maximum Acceptable Oral Reading Speed (MAORS) for an 8-hour period using psychophysical methodology. Results indicate that 114 words/min was an acceptable oral reading rate for an 8-hour day. Furthermore, 2 hours and 20 minutes is an acceptable testing period ( equivalent to the 8-hour day). Acoustical and physiological variables support these findings. Experiment two was designed to study the effect of …

Air Cargo As A Different Business Unit, Juan M. Gomez

Master's Theses - Daytona Beach

By combining cargo and passenger operations under the same business, airlines are facing an operational conflict with respect to the cargo operation, which has always been perceived as a by-product and not as an essential revenue generating activity; This fact leads to poor product quality, weak revenues, and value deterioration. By dedicating time and resources to the cargo operation in a different business unit with a defined strategy, carriers may increase cargo profitability and achieve superior operational results.

The purpose of this study is to identify and explain the benefits for passenger airlines to invest in air-cargo operations by defining …

Acuta Enews April 2001, Vol.30, No. 4

ACUTA Newsletters

International Rates Increasing

Guide to Developing Online Students Services

DC Update

Detariffing International Service

VIPs Visit Carnegie-Mellon

Board Report

Welcome New Members

Positions Available

Hide Glue Applicator, Chris Campo, Benjamin Carrasco, Elias Saliba

Mechanical Engineering

This study investigates the challenges inherent in applying hide glue in the crafting of violin and other stringed instruments. Hide glue, derived from animal collagen and protein, is essential for creating durable bonds that allow for necessary adjustments during fabrication. However, its meticulous heating and maintenance requirements pose logistical obstacles for luthiers lacking viable alternatives. To tackle this issue comprehensively, our project comprises several key components.

Initially, we conducted an in-depth analysis of the hide glue application process, delineating procedural steps and techniques to establish our design criteria and constraints. This foundational understanding formed the basis for further exploration. Additionally, …

Statistical Properties Of Maximum Likelihood Estimates For Accelerated Lifetime Data Under The Weibull Model, Mahmoud A. Yousef

Doctoral Dissertations

Pipe rehabilitation liners are often installed in host pipes that lie below the water table. As such, they are subjected to external hydrostatic pressure. The external pressure leads to early deformation in the liners, which could ultimately lead to its failing or buckling before its expected service lifetime is achieved. Experiments involving long term buckling behavior of liners are typically accelerated lifetime testing procedures. In an accelerated testing procedure a liner is subjected to a constant external hydrostatic pressure and observed until it fails or for a certain time, t whichever occurs first. Liners that do not fail at time …

Mitigation Of Water Vapor Interference For Infrared Polarization-Modulated Gas Filter Correlation Radiometry, David K. Lockwood

Electrical & Computer Engineering Theses & Dissertations

Gas filter correlation radiometry (GFCR) is a high-resolution, high-specificity technique for sensing gaseous species. A variation of absorption spectroscopy, GFCR has a long-proven record on orbital platforms for quantitative measurements of atmospheric constituents, as well as common usage in ground-based sensing applications. PMGFCR (Polarization-modulated GFCR) is a recent refinement of the technique with several advantages over the traditional method, including reducing the number of photodetectors required, increased sensitivity, and elimination of moving parts.

To date, no infrared remote sensors have successfully measured nitric oxide (NO) in vehicle exhaust due to spectral overlap by strong water vapor (H₂O_{v …}