Engineering Commons^™

Wthd-Optimal Staircase Modulation Of Single-Phase Multilevel Inverters, B. Diong, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

Glucose Oxidase (God)-Coupled Amperometric Microsensor With Integrated Electrochemical Actuation System, Jongwon Park, Chang-Soo Kim, Minsu Choi, Shanrui Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

Recent developments for biosensors have been mainly focused on miniaturization and exploratory use of new materials. It should be emphasized that the absence of a novel "in-situ self-calibration/diagnosis technique" that is not connected to an external apparatus is a key obstacle to the realization of a biosensor for continuous use with minimum attendance. In order to address this issue, a novel solid-state glucose oxidase-coupled amperometric biosensor with integrated electrochemical actuation system has been designed and validated. There are two key components of the proposed glucose biosensor: solid-state GOD-coupled thin-lm amperometric sensing element and O₂ depleting/saturating built-in electrochemical actuator. The …

Bimetallic Pt-Ag And Pd-Ag Nanoparticles, Frank D. Blum, Akira Tokuhiro, Massimo F. Bertino, Carmen M. Doudna

Chemistry Faculty Research & Creative Works

We report studies of bimetallic nanoparticles with 15%-16% atomic crystal parameters size mismatch. The degree of alloying was probed in a 2-nm Pt core (smallest attainable core size) of Pt-Ag nanoparticles (completely immiscible in bulk) and 20-nm-diameter Pd-Ag nanowires (completely miscible in bulk). Particles were synthesized radiolytically, and depending on the initial parameters, they assume spherical or cylindrical (nanowire) morphologies. In all cases, the metals are seen to follow their bulk alloying characteristics. Pt and Ag segregate in both spherical and wire forms, which indicates that strain due to crystallographic mismatch overcomes the excess surface free energy in the small …

Thermochemistry Of La 1-Sr Xfeo 3-Δ Solid Solutions (0.0 ≤ X ≤ 1.0, 0.0 ≤ Δ ≤ 0.5), Jihong Cheng, Alexandra Navrotsky, Xiao Dong Zhou, Harlan U. Anderson

Materials Science and Engineering Faculty Research & Creative Works

A series of compounds with the general formula La_1-xSr_xFeO_3-δ have been synthesized in the complete solid solution range 0.0 ≤ x ≤ 1.0 and 0.0 ≤ δ ≤ 0.5 with a variety of heat treatments. High temperature drops solution calorimetry in molten 2PbO·B₂O₃ at 702 °C was performed to determine their enthalpies of formation from oxides at room temperature. the enthalpy of oxidation involved in the reaction 2Fe^X_Fe + V _O^•• + 0.5O 2(g) = 2Fe _Fe^• + O _O^X is independent of oxygen nonstoichiometry in each …

An Exafs Investigation Of Rare-Earth Local Environment In Ultraphosphate Glasses, M. Karabulut, E. Metwalli, A. K. Wittenauer, Richard K. Brow, G. K. Marasinghe, C. H. Booth, J. J. Bucher, D. K. Shuh

Materials Science and Engineering Faculty Research & Creative Works

The local structures around rare-earth ions in rare-earth ultra phosphate glasses (nominally 15RE₂O₃-85P₂O₅, mol%, RE = Nd, Sm, Gd, Ho, and Er) and metaphosphate glasses (nominally 25RE₂O₃-75P₂O₅, mol%, RE = Nd, Gd, and Er) have been studied by extended X-ray absorption fine structure spectroscopy (EXAFS) at the respective rare-earth LIII edges. the RE-O distance decreases with increasing atomic number of the rare-earth ion for both ultra and metaphosphate glasses. on average, RE-O distances for metaphosphate glasses are shorter than those for ultra phosphate glasses …

Aisi Standard For Cold-Formed Steel Framing – Header Design, 2004 Edition, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the Commentary. With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. It is …

Standard For Cold-Formed Steel Framing- Lateral Design, 2004 Edition, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specificreferences are included in the Commentary.

With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. It is anticipated …

Standard For Cold-Formed Steel Framing-Header Design, 2004 Edition, American Iron And Steel Institute

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

The material contained herein has been developed by the American Iron and Steel Institute Committee on Framing Standards. The Committee has made a diligent effort to present accurate, reliable, and useful information on cold-formed steel framing design and installation. The Committee acknowledges and is grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included in the Commentary.

With anticipated improvements in understanding of the behavior of cold-formed steel framing and the continuing development of new technology, this material may eventually become dated. It is …

The Coupling Effect Of Interfacial Adhesion And Tensile Residual Stress On A Thin Membrane Adhered To A Flat Punch, Kai Tak Wan, Lior Kogut

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Adhesion and residual stress play a critical role in the performance and reliability of microdevices, in particular, the cross bridge of RF microswitches. to investigate their combinatorial influences on thin films, an elastic model is constructed for a clamped circular membrane in contact with the planar surface of a rigid cylindrical punch. External force applied to the punch leads to thin film delamination and ultimately 'pull-off' at a critical non-zero contact radius. Characteristic trends of the mechanical responses were obtained for fixed load and fixed grips in terms of pull-off force, punch displacement and contact radius. It is shown that …

User-Controlled, Multimedia-Enhanced Communication Using Prior Knowledge And Experience, S. R. Subramanya, Byung K. Yi

Electrical and Computer Engineering Faculty Research & Creative Works

This article focuses on enriching the communication, experience between human beings interacting through different kind of devices, including mobile phones and PDAs. the key point is how to effectively exploit multimedia data to enhance the richness of communication without overloading the communication channel. to this end, the system tries to minimize the quantity of information transmitted over the networks and to maximize the usage of locally stored information. the proposed system sends several kinds of data, including continuous video, video clips, still images, and avatars, over the communication channel. the specific data that are sent are based on the parameters …

Size Evaluation Of Corrosion Precursor Pitting Using Near-Field Millimeter Wave Nondestructive Testing Methods, Mohammad Tayeb Ahmad Ghasr, Brian D. Carroll, Sergey Kharkovsky, R. Zoughi, R. Austin

Electrical and Computer Engineering Faculty Research & Creative Works

Early detection of corrosion precursor pitting and estimation of its overall dimensions directly affects the required effort and cost associated with repair and maintenance of critical aircraft structural components. The magnitude and phase of a reflected signal from a pitting are directly related to its dimensions. This paper presents a millimeter wave probe and a sizing procedure used to detect and evaluate overall pitting dimensions.

Behavior And Fatigue Properties Of Metallic Dampers For Seismic Retrofit Of Highway Bridges, Genda Chen, Stephen Eads

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The objective of this study is to develop an economical solution with metallic dampers for the seismic retrofit of highway bridges in low occurrence seismic zones, such as in the Central and Eastern United States. Select low carbon steel rods were first tested for their ductile behavior and material strength. Large-scale, tapered rods were then tested for their energy dissipation capability and fatigue strength under regular, irregular, and earthquake loads. A full-scale damper made of five tapered rods was designed next for the seismic retrofit of a three-span continuous steel-girder bridge in southeast Missouri; its system performance including joints and …

Flow Pattern Visualization In A Mimic Anaerobic Digester Using Cfd, Mehul S. Vesvikar, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Three-Dimensional Steady-State Computational Fluid Dynamics (CFD) Simulations Were Performed in Mimic Anaerobic Digesters to Visualize their Flow Pattern and Obtain Hydrodynamic Parameters. the Mixing in the Digester Was Provided by Sparging Gas at Three Different Flow Rates. the Gas Phase Was Simulated with Air and the Liquid Phase with Water. the CFD Results Were First Evaluated using Experimental Data Obtained by Computer Automated Radioactive Particle Tracking (CARPT). the Simulation Results in Terms of overall Flow Pattern, Location of Circulation Cells and Stagnant Regions, Trends of Liquid Velocity Profiles, and Volume of Dead Zones Agree Reasonably Well with the Experimental Data. …

Hydrogeophysical Investigation At Luxor, Southern Egypt, Ahmed Ismail, Neil Lennart Anderson, J. David Rogers

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Over the past 35 years, the exposed stone foundations of the ancient Egyptian monuments at Luxor have deteriorated at an alarmingly accelerated rate. Accelerated deterioration is attributable to three principal factors: 1) excavation and exposure of foundation stone; 2) construction of the Aswan High Dam; and 3) changes in the regional groundwater regime. In an effort to better elucidate the hydrostratigraphy in the Luxor study area that extends from the River Nile to the boundaries of the Nile Valley and covers about 70 km², a geophysical/hydrological investigation was conducted. Forty Schlumberger vertical electrical soundings (VES), two approximately 6 …

A Systematic Method For Characterizing The Elastic Properties And Adhesion Of A Thin Polymer Membrane, Bing Feng Ju, Yang Ju, Masumi Saka, Kuo Kang Liu, Kai Tak Wan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The elastic properties and adhesion of a thin silicone rubber membrane have been characterized. an effective instrumentation embodying a video-enhanced microscope, which meets force and displacement resolution of 0.1μN and 10 nm, was developed. It provides the capability of simultaneously measuring both the applied force and the resultant displacement of the thin polymer membrane. a linear theoretical elastic solution was applied to quantitatively interpret the measured central deflection of the membrane under a circular concentrical load. Young's modulus of the membrane can be easily determined once the applied force and the central deflection, together with the essential dimensions, are known. …

Lessons Learned From Failures Of The Building Envelope In Windstorms, Joseph E. Minor

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Lessons learned from failures of the building envelope in windstorms are encapsulated in three principal findings. the building envelope is crucial to the performance of buildings in windstorms. Windborne debris is decisive in shaping the performance of the building envelope. Design attention should be given to postimpact behavior of building-envelope systems. Reviews of damage documentation, insurance records, and computer simulations of building failures establish the importance of the building envelope to satisfactory building performance. These reviews also establish the decisive role of windborne debris in causing damage. the imperative for considering the postimpact behavior of building envelope systems is discussed, …

Analysis And Design Of Switched Capacitor Converters, Jonathan W. Kimball, Philip T. Krein

Electrical and Computer Engineering Faculty Research & Creative Works

Switched capacitor converters have become more common in recent years. Crucial to understanding the maximum power throughput and efficiency is a model of the converter's equivalent resistance. A new form for equivalent resistance is derived and discussed in a design context. Quasi-resonant operation is also explored and compared to non-resonant operation. Several capacitor technologies are evaluated and compared.

Experimental Investigation Of The Hydrodynamics In A Liquid-Solid Riser, Shantanu Roy, Abdenour Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Liquid-Solid Fluid Dynamics Has Been Investigated in a 6-In. (0.15 M) "Cold-Flow" Circulating Fluidized Bed Riser using Non-Invasive Flow Monitoring Methods. Gamma-Ray Computed Tomography (CT) Was Used to Measure the Time-Averaged Cross-Sectional Solids Volume Fraction Distributions at Several Elevations. the Time-Averaged Mean and "Fluctuating" Solids Velocity Fields Were Quantified using the Computer-Automated Radioactive Particle Tracking (CARPT) Technique. the Experimental Equipment, Protocol of Implementation, and Data Analysis Have Been Discussed Briefly, with Particular Emphasis on the Specific Features in the Use of These Techniques for Studying High-Density Turbulent Flows as in a Liquid-Solid Riser. the Experimental Study Examines Nine Operating Conditions, …

Cold-Formed Steel Gable End Wall Design Using The Prescriptive Method For One And Two Family Dwellings, Benjamin W. Downey, Sutton F. Stephens, Roger A. Laboube

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

No abstract provided.

Ccfss Technical Bulletin Spring 2005, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Improving Voltage Stability By Reactive Power Reserve Management, Feng Dong, Badrul H. Chowdhury, Mariesa Crow, Levent Acar

Electrical and Computer Engineering Faculty Research & Creative Works

The amount of reactive reserves at generating stations is a measure of the degree of voltage stability. With this perspective, an optimized reactive reserve management scheme based on the optimal power flow is proposed. Detailed models of generator limiters, such as those for armature and field current limiting must be considered in order to utilize the maximum reactive power capability of generators, so as to meet reactive power demands during voltage emergencies. Participation factors for each generator in the management scheme are predetermined based on the voltage-var (V-Q) curve methodology. The Bender's decomposition methodology is applied to the reactive reserve …

The Matrix Pencil For Power System Modal Extraction, A. Singh, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

This work introduces the matrix pencil modal extraction method through the use of several illustrative examples. This method is used to estimate the eigenvalues of reduced-order models of large nonlinear systems based on their dynamic responses.

Work In Progress - Automated Discourse Interventions And Student Teaming, Ray Luechtefeld, Steve Eugene Watkins, Ralph E. Flori

Engineering Management and Systems Engineering Faculty Research & Creative Works

The ability to successfully work in teams is a crucial part of an engineer's workplace success. Engineering education can be improved through a better understanding of how effective teamwork develops. A (patent pending) software tool that "listens" to team conversations and generates automatic interventions into team discourse can effectively mimic the actions of a skilled facilitator. Automated facilitation tools may help students improve their team skills by providing a simplified model for conversational interventions, which students can readily imitate. This paper describes this tool and presents preliminary findings from student reactions to the tool's use.

Pulse Regulation Control Technique For Integrated High-Quality Rectifier-Regulators, Mehdi Ferdowsi, Ali Emadi

Electrical and Computer Engineering Faculty Research & Creative Works

The pulse regulation control scheme is presented and applied to the boost integrated flyback rectifier/energy storage dc/dc (BIFRED) converter as the most popular member of the integrated high-quality rectifier-regulators (IHQRR). In contrast to the conventional control techniques, the principal idea of pulse regulation is to regulate the output voltage using a series of high- and low-power pulses generated by the current of the input inductor, which is operating in discontinuous conduction mode (DCM). Analysis of the BIFRED converter operating in DCM is presented. Fundamentals of pulse regulation as well as its stability analysis and the estimation of the output voltage …

Reinforcement Learning-Based Output Feedback Control Of Nonlinear Systems With Input Constraints, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel neural network (NN) -based output feedback controller with magnitude constraints is designed to deliver a desired tracking performance for a class of multi-input-multi-output (MIMO) discrete-time strict feedback nonlinear systems. Reinforcement learning in discrete time is proposed for the output feedback controller, which uses three NN: 1) a NN observer to estimate the system states with the input-output data; 2) a critic NN to approximate certain strategic utility function; and 3) an action NN to minimize both the strategic utility function and the unknown dynamics estimation errors. The magnitude constraints are manifested as saturation nonlinearities in the output feedback …

A Graph-Based Model For Component-Based Software Development, Sahra Sedigh, Arif Ghafoor

Electrical and Computer Engineering Faculty Research & Creative Works

Software metrics can be used to objectively quantify the quality of software components and systems, alleviating quality and risk concerns and raising assurance in component-based systems. In this paper, we present a graph-based model for component-based software development. We assume that a number of components have been characterized in terms of non-functional metrics of importance to the software system being developed, and that the interfaces connecting various components have been similarly characterized. The emphasis of this work is on cost and quality of the system under development, and reaching an acceptable compromise between the two.

Catalytic Wet Air Oxidation Of Phenol In Concurrent Downflow And Upflow Packed-Bed Reactors Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Experimental Study is Presented for Comparing the Behavior of a Packed Bed Reactor in the Catalytic Liquid-Phase Oxidation of Aqueous Phenol with Two Modes of Operation, Downflow and Upflow. the Operating Parameters Investigated Included Temperature, Reactor Pressure, Gas Flowrate, Liquid Hourly Space Velocity and Feed Concentration. Because of the Completely Wetted Catalyst, the Upflow Reactor Generally Performs Better for High Pressures and Low Feed Concentrations When the Liquid Reactant Limitation Controls the Rate. the Interaction between the Reactor Hydrodynamics, Mass Transfer, and Reaction Kinetics is Discussed. for Both Operation Modes, Complete Phenol Removal and Significant Total Organic Carbon (TOC) …

Ccfss News Spring 2005, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Newsletters (1999 - 2008)

No abstract provided.

Supplement 2004 To The North American Specification For The Design Of Cold-Formed Steel Structural Members 2001 Edition, American Iron And Steel Institute

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

The material contained herein has been developed by a joint effort of the American Iron and Steel Institute Committee on Specifications, the Canadian Standards Association Technical Committee on Cold Formed Steel Structural Members (S136), and Camara Nacional de la Industria del Hierro y del Acero (CANACERO) in Mexico. The organizations and the Committees have made a diligent effort to present accurate, reliable, and useful information on cold-formed steel design. The Committees acknowledge and are grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included …

Supplement 2004 To The North American Specification For The Design Of Cold-Formed Steel Structural Members, American Iron And Steel Institute

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

The material contained herein has been developed by a joint effort of the American Iron and Steel Institute Committee on Specifications, the Canadian Standards Association Technical Committee on Cold Formed Steel Structural Members (S136), and Camara Nacional de la Industria del Hierro y del Acero (CANACERO) in Mexico. The organizations and the Committees have made a diligent effort to present accurate, reliable, and useful information on cold-formed steel design. The Committees acknowledge and are grateful for the contributions of the numerous researchers, engineers, and others who have contributed to the body of knowledge on the subject. Specific references are included …