Engineering Commons^™

Characterization And Optimization Of A Chromatographic Process Based On Ethylenediamine-N,N,N′,N′-Tetra(Methylphosphonic) Acid-Modified Zirconia Particles, Sabyasachi Sarkar, Peter W. Carr, Clayton V. Mcneff, Anuradha Subramanian

Papers in Biotechnology

The primary objective of work was to characterize, optimize and model a chromatographic process based on ethylenediamine-N,N,N′,N′-tetra(methylphosphonic) acid (EDTPA)-modified zirconia particles. Zirconia particles were produced by spray-drying colloidal zirconia. Zirconia spheres produced were further classified, calcined and modified with EDTPA to yield a solid-phase support for use in bio-chromatography (r_PEZ). Specifically, the ability of r_PEZ to selectively bind and enrich IgG, IgA, and IgM from biological fluids was evaluated and demonstrated. To better understand the force of interaction between the IgG and the r_PEZ, the equilibrium disassociation constant (Kd) was determined by static binding isotherms, as a function of temperature …

Nasa - Jpl: Space Adventures By Stanford Students & Mentors, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "NASA - JPL: Space Adventures by Stanford Students & Mentors" from June 25, 2003.

A Self-Retracting Fully Compliant Bistable Micromechanism, Nathan D. Masters, Larry L. Howell

Faculty Publications

A new class of fully compliant bistable mechanisms with the added benefit of integrated self-retraction has been developed (hereafter identified as Self-Retracting Fully compliant Bistable Mechanism or SRFBM). A technique using tensural pivots to manage compressive loading in compliant mechanisms is introduced and implemented in the SRFBM. The elimination of traditional kinematic joints and their associated clearance allows a total displacement between stable positions of 8.5 m, and the mechanism size is less than 300 m square when using 2.0 m minimum line widths. Maximum actuation force is approximately 500 N. The SRFBM's small linear displacement and reasonable actuation force …

Optical Communications By Frequency Content Of Femtosecond Laser Pulses, Dennis Alexander, Mark L. Rohlfs

Department of Electrical and Computer Engineering: Faculty Publications

A free-space optical communications System is provided capable of transmitting data over long distances through the atmosphere. The communications System according to the present invention comprises an optical transmitter at a first location, the optical transmitter comprising a femtosecond pulsed laser Source for producing a train of femtosecond laser pulses. The optical transmitter further comprises a laser pulse width modulator to provide a pulse width modulated train of femtosecond laser pulses corresponding to the data being transmitted. The communications System further com prises an optical receiver at a Second location for receiving the modulated train of femtosecond laser pulses. The …

The Displacement Of The Thermally Grown Oxide In Thermal Barrier Systems Upon Temperature Cycling, Anette M. Karlsson, J. W. Hutchinson, A. G. Evans

Mechanical Engineering Faculty Publications

Models that characterize the displacement instability of the thermally grown oxide (TGO) found in some thermal barrier systems are reviewed, consolidated and extended. It is demonstrated that the simulations are only consistent with the observations whenever the bond coat and TGO both undergo plastic deformation. The TGO yields at the peak temperature, during growth, while the bond coat yields on thermal cycling. The trends oppose. Namely, the TGO displacement is diminished by increasing the high temperature strength of the bond coat, but is increased upon increasing the TGO strength. The model rationalizes certain experimental trends, particularly the decrease in durability …

Identification Of Macro- And Micro-Compliant Mechanism Configurations Resulting In Bistable Behavior, Brian D. Jensen

Theses and Dissertations

The purpose of this research is to identify the configurations of several mechanism classes which result in bistable behavior. Bistable mechanisms have use in many applications, such as switches, clasps, closures, hinges, and so on. A powerful method for the design of such mechanisms would allow the realization of working designs much more easily than has been possible in the past. A method for the design of bistable mechanisms is especially needed for micro-electro-mechanical systems (MEMS) because fabrication and material constraints often prevent the use of simple, well-known bistable mechanism configurations. In addition, this knowledge allows designers to take advantage …

A Self-Retracting Fully-Compliant Bistable Micromechanism, Nathan D. Masters

Theses and Dissertations

The purpose of this research is to present a class of Self-Retracting Fully-compliant Bistable Micromechanisms (SRFBM). Fully-compliant mechanisms are needed to overcome the inherent limitations of microfabricated pin joints, especially in bistable mechanisms. The elimination of the clearances associated with pin joints will allow more efficient bistable mechanisms with smaller travel. Small travel, in a linear path facilitates integration with efficient on-chip actuators. Tensural pivots are developed and used to deal with the compressive loading to which the mechanism is subject. SRFBM are modeled using the Pseudo-Rigid-Body Model and finite element analysis. Suitable configurations of the SRFBM concept have been …

In Situ Uv-Visible Assessment Of Extent Of Reduction During Oxidation Reactions On Oxide Catalysts, Morris D. Argyle, Kaidong Chen, Carlo Resini, Catherine Krebs, Alexis T. Bell, Enrique Iglesia

Faculty Publications

The extent of reduction of active centers during oxidative alkane dehydrogenation on VOx/Al2O3 was measured from pre-edge UV-visible spectral features and found to increase with increasing VOx domain size and propane/O2 ratio.

Jun 2003, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Rehabilitation of Behlen Building Test Car Location Inside Insulation

Actuator Fault Compensation For A Helicopter Model, Xiao-Hua Yu

Electrical Engineering

A fault-tolerant system is the one that can continue its operation without significant impact on performance in the presence of hardware and/or software errors. In this paper, the design of a fault-tolerant flight controller to control UH-60 helicopter is investigated. A 9th-order state space representation of the helicopter model operating at the forward mode with 80 knots is presented; then a fault-tolerant optimal feedback controller is designed and tested.

A Multiobjective Sdss For Management Of Urbanizing Watersheds: The Case Of The Lower Kaskaskia Basin, Illinois, Kyle O. Allred, John W. Nicklow, Misgana K. Muleta, Leslie A. Duram

Civil and Environmental Engineering

The conversion of natural and agriculturally dominated watersheds to industrial, commercial and residential developments leads to a cascade of adjustments in runoff quantity and stream quality at locations further downstream. The use of sophisticated hydrologic simulation models and Geographic Information Systems (GIS) has become the standard for evaluating these impacts of urban sprawl on water resources systems. Simulation and GIS models alone, however, are incapable of directly revealing optimal land development patterns that meet specified objectives. This paper describes the development of a multi-objective Spatial Decision Support System (SDSS) designed to overcome this limitation. The SDSS is created by integrating …

Engineering The World: Hands-On Experimentation For Civil Engineering K-12 Outreach, James L. Hanson, Donald D. Carpenter, Tarek Rizk

Civil and Environmental Engineering

This paper details the development and application of a community outreach program designed to teach children about math, science, and the world in which they live. The program was titled “Engineering the World” and emphasized civil engineering applications. The program was offered in an inner-city middle school in Detroit, Michigan. The program was developed by civil engineering professors at Lawrence Technological University with the assistance of undergraduate engineering students. The activities were categorized by civil engineering discipline including construction, environmental, geotechnical, hydraulics, structural, surveying, and transportation. The paper describes details of several of the hands-on experiments and provides an assessment …

Niti - Magic Or Phase Transformation?, Katherine C. Chen

Materials Engineering

NiTi alloys possess exciting properties and are staples in materials demonstrations. The shape memory effect and superelasticity property of NiTi fascinate people, but actually require significant materials knowledge to fully understand the phenomena. A laboratory dealing with phase transformations was thus developed to capitalize on the allure of NiTi for a junior/senior level “Thermodynamics and Kinetics of Materials” course. Students examine and characterize the shape memory and superelastic properties of NiTi wire, and then realize the difference is in the transformation temperature (i.e., Af - the austenitic finish temperature). They then use the phase diagram and TTT diagram to develop …

How We Learned To Love The Phase Diagram With A Ti-Cr Alloy Characterization Lab, Katherine C. Chen

Materials Engineering

While many students learn how to read and use a phase diagram in introductory materials courses, greater appreciation for such a tool can be garnered through the laboratory setting. A laboratory module for a “Structures of Materials” class (a “core class” for materials majors) has been developed to demonstrate the usefulness of phase diagrams, as well as, to emphasize the connections among processing, structure, and properties. Competence in determining stable phases, phase compositions, and mass fractions of phases are not the end goal, per se, but transpire since the skills are required to help solve a puzzle. Students are given …

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Annual Progress Report (May 2002 – May 2003), Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

As indicated in the original proposal, the primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate target materials for applications in spallationneutron- target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). The materials selected for evaluation and characterization are martensitic stainless steels including Alloy HT-9, Alloy EP 823 and Type 422 stainless steel. The susceptibility to stress corrosion cracking (SCC) and hydrogen embrittlement (HE) of these materials are being evaluated in aqueous environments of interest using tensile specimens under constant load and slow-strain-rate (SSR) conditions. …

Use Of Positron Annihilation Spectroscopy For Stress-Strain Measurements: Annual Progress Report (May 2002 – May 2003), Ajit K. Roy

Transmutation Sciences Materials (TRP)

The purpose of this collaborative research project involving the University of Nevada Las Vegas (UNLV) and Idaho State University (ISU) to evaluate the feasibility of determining residual stresses of welded, bent (three-point-bend), and cold-worked engineering materials using a new non-destructive technique based on positron annihilation spectroscopy. The proposed technique is the use γ-rays from a small MeV electron Linear accelerator (LINAC) to generate positrons inside the sample via pair production. This method can be used for materials characterization and investigation of defects in thick samples, which could not be accomplished by conventional positron technique or other non-destructive methods. The data …

Apparatus, Method And System For Common-Mode Stabilization In Circuits Having Differential Operation, George Palaskas, Vladimir Prodanov

Electrical Engineering

A system, method and apparatus are disclosed for common-mode voltage feedback. The preferred system includes a plurality of differential circuits, a corresponding plurality of common-mode voltage detectors, a corresponding plurality of buffer circuits, and a common-mode control circuit. Each differential circuit is operative to produce a first differential output voltage and a second differential output voltage. Each corresponding common-mode voltage detector is operative to provide a common-mode voltage from the first differential output voltage and the second differential output voltage. The common-mode control circuit provides a control voltage signal from the common-mode voltage and from a reference voltage. Each buffer …

Development Of In-Plane Compliant Bistable Microrelays, Troy Alan Gomm

Theses and Dissertations

Bistable microrelays have many possible applications and have the potential to reduce the size, weight, power consumption, and cost of products in which they are used. This research outlines the current state of microrelays, presents three new compliant bistable micromechanisms, and characterizes their performance as microrelays. The characterization includes a treatment of a new force-tester, a preliminary contact resistance study, contact-force measurements, switching time measurements, insertion loss, AC isolation, breakdown voltage, and DC isolation. This document also includes recommendations for further research.

The Multi-Application Survivable Tether (Mast) Experiment, Robert J. Twiggs, Robert Hoyt, Jeffrey Slostad

Robert "Bob" Twiggs STEM Education Collection

An article by Bob Twiigs, Robert Hoyt, and Jeffrey Slostad titled "The Multi-Application Survivable Tether (MAST) Experiment" from June 16, 2003.

Aircraft Turbofan Engine Health Estimation Using Constrained Kalman Filtering, Daniel J. Simon, D. L. Simon

Electrical and Computer Engineering Faculty Publications

No abstract provided.

Phase Ii: Design And Analysis Of A Process For Melt Casting Metallic Fuel Pins Incorporating Volatile Actinides, Yitung Chen, Randy Clarksean, Darrell Pepper

Fuels Campaign (TRP)

This research report develops a model to analyze the transport of americium from the melt to the vapor phase above the crucible. The model considers mass transport in the melt, vaporization at the surface, and transport through the vapor phase. The greatest problem with the model is the uncertainty of the thermodynamic properties of the proposed ternary alloy. The details of the model and the specific quantities needed for the physical properties will be discussed.

Comparison Matrix Method And Its Applications To Damage Evaluation For Existing Reinforced Concrete Bridges, Ming-Te Liang, Chin-Ming Lin, Chi-Jang Yeh

Journal of Marine Science and Technology–Taiwan

The main purpose of this paper was adopting the comparison matrix method, which is generated from both the analytic hierarchy process and the principle of moment equilibrium, to assess the repair order of existing reinforced concrete (RC) bridges. Ten existing RC bridges in Keelung, Taiwan, were given as an illustrative example. In order to verify the feasibility and reliability of the proposed method, the D (Degree) E (Extend) R (Relevancy) evaluation method, which is now widely used to evaluate the damage grade for existing RC bridges in Taiwan, was also applied to assessing the same ten existing RC bridges. The …

Design Of Fuzzy Nonlinear Robust Compensator And Its Application On Submarines, Cheng-Neng Hwang, Joe- Ming Yang

Journal of Marine Science and Technology–Taiwan

A robust nonlinear composite controller, which is simple in structure and has the characteristics of good tracking performance and guaranteed system stability, is designed in this study. A pre-compensator is proposed to eliminate uncertainties or disturbances so that the tracking error is bounded in a pre-specified ball. The composite control law proposed in this study guarantees system tracking precision and stability by the aid of a third-order differential equation that has been derived in this research. The control parameters in the proposed controller can be adjusted systematically. For unknown serious variation in system surrounding, a composite control law with fuzzy-type …

Parameter Analysis And Optimization Of Electrolytic In-Process Dressing Grinding On Ceramics, Chang-Pin Lin, Kuei-Miao Hsiao, Chun-Chung Wu

Journal of Marine Science and Technology–Taiwan

Ceramic materials have been studied and used in considerable industrial applications due to their high hardness and strength at high temperature and extreme wear resistance. However, the machining costs of these materials may reach as high as 90% of their total component costs and the grinding of these materials are much more susceptible to surface damage as compared to metals. Electrolytic InProcess Dressing (ELID) grinding can be used to machine hard and brittle materials, such as aluminum oxide (Al2O3), that are difficult to be machined by conventional grinding processes to achieve high surface quality and high material removal rate. The …

Study Of Yuen-Lin Liquefaction During Chi-Chi Earthquake, Shuhgi Chern, Juei-Hsing Tsai, Ching-Yinn Lee

Journal of Marine Science and Technology–Taiwan

Extensive subsurface exploration of Yuen-Lin liquefaction area was conducted by National Science Council after Chi-Chi earthquakes. Data obtained from the subsurface exploration in Yuen-Lin area had been studied and three widely used liquefaction evaluation methods, i.e. Seed method, T-Y method and JRA method, were employed for liquefaction evaluation. The depth of the liquefied soil layer was also identified by comparison of grain size distribution curve of explored sample and field data. Iwasaki's liquefaction potential index was further used to analyze liquefaction induced risk of damage. Finally, Multiple Additive Decision Making method (MADM) was applied to determine the suitability of the …

A Generative Programming Framework For Adaptive Middleware, Venkita Subramonian, Christopher Gill

All Computer Science and Engineering Research

Historically, many distributed real-time and embedded (DRE) systems were developed manually from scratch, leading to stove-piped solutions that while correct in both functional and QoS properties were very expensive to develop and difficult to maintain and extend. First-generation middleware technologies such as CORBA 2.x [1], XML [2], and SOAP [3], served to shield application developers from low-level platform details, thus raising the level of abstraction at which distributed systems are developed and supporting reuse of infrastructure to amortize development costs over the lifetime of a system. However, interdependencies between services and object interfaces resulting from these programming models significantly limited …

Renewable Energy Limits, Florida Solar Energy Center, Ross Mccluney

FSEC Energy Research Center®

"The more we get out of the world the less we leave, and in the long run we shall have to pay our debts at a time that may be very inconvenient for our own survival." - Norbert Wiener

Introduction: The world's energy and environmental crises are inextricably linked. The processes of extracting, processing, and burning fossil fuels generates copious pollution of air, water, and land. Fossil-fuel-derived energy lies at the heart of other environmental problems. Fossil energy powers the bulldozers clearing rainforests. It runs the tractors and other farm equipment of industrial agriculture, compacting and mineralizing soils thus increasing …

Crawl, Walk, Run & Fly: Some Experiments To Try, Robert J. Twiggs

Robert "Bob" Twiggs STEM Education Collection

A PowerPoint Presentation created by Professor Bob Twiggs titled "Crawl, Walk, Run & Fly: Some Experiments to Try" from June 13, 2003.

Cappsii: Caveats On Progress, Ibpp Editor

International Bulletin of Political Psychology

This article identifies potential security shortfalls even in the context of improvements in counterterrorist profiling.

Interfacial Edge Crack Between Two Bonded Dissimilar Orthotropic Strips Under Antiplane Point Loading, Xiangfa Wu, Yuris A. Dzenis, Wen-Sheng Zou

Department of Engineering Mechanics: Faculty Publications

A closed-form solution is obtained for the interfacial edge crack between two bonded dissimilar orthotropic strips loaded by antiplane point loading in form of screw dislocation or line force. Conformal mapping and existing dislocation solutions are utilized for constructing the fundamental solution of the problem. The stress intensity factor (SIF) and the energy release rate(ERR) are obtained explicitly.