Engineering Commons^™

Electrochemical Behaviors Of Isoalloxazine Confined In Montomorillonite Olay Modified Electrode, Zhibin Wu, Yuan Lin, Daodao Zhang, Haoqin Wu

Journal of Electrochemistry

A cyclic voltametric investigation of stability and redox properties of isoalloxazne on cetytrimethyammonium bromide (CTAB) modified montomorillonite clay platinium electrode in aqueous solution has been performed. pH dependent film concentrations and apparent diffusion coefficents were measured. The mechanism of the charge transport process with in the clay film were discussed.

Studies On The Cathodic Current Efficiency In The Electrodeposition Ni-Psz Gradient Coating, Jun Li, Dianlong Wang, Li Chen, Xinguo Hu

Journal of Electrochemistry

The cathodic current efficiency and the electrochemical behavior in electrodeposition Ni-PSZ gradient coating were investigated by various electrochemical techniques and scanning electron microscope. The results showed that the Ni-PSZ composite coatings can accelerate evolution of hydrogen with the increase of PSZ content. The overpotential of nickel reduction will be increased and that of hydrogen reaction will be reduced in the presence of PSZ particles in electrolyte. The effect of PSZ particles on nickel electrodeposition was preferentially to catalyze the formation of H ads . These all contributed to the lower current efficiency.

Study On Properties Of Magnesium Alloy Electrode With Anodized Film, Yi Chi, Ping Yang, Xiufeng Lin

Journal of Electrochemistry

The corrosion resistance of Mg alloy electrode with anodized film in atmosphere is bigger than that of the Mg alloy electrode with chromate film. The corrosion resisance and voltage delay of such electrode with anodized film in NaCl solution changed with anodizing comdition. The effects of composition, morphology and thickness of the anodized film on the peoperty of Mg alloy electrode are discussed.

Studies On An Iron Heteropolyacid Redox Flow Battery, Peiju Sun, Wansheng You, Zhorgyin Tan

Journal of Electrochemistry

This paper reports a new Fe-HP redox flow cell. The positive and negative electrodes active materials are phosphomolybdic acid and acidified ferrous sulphate solutions respectively. Two activated porous carbon felt electrodes where the electrochemical reactions take place, are separated by a selective cation exchange membrane. The both couples have a suitable electrochemical reversibility on carbon and graphite electrodes. The active materials of the cell have very high stability. Moreover the cell has no life cycle limiting.

High-Bandwidth Attitude Jitter Determination For Pointing And Tracking Systems, Marcelo C. Algrain

Department of Electrical and Computer Engineering: Faculty Publications

For many reasons smaller spacecraft are becoming more appealing. Because of their lower inertias, these spacecraft are more sensitive to disturbances and likely to have more attitude jitter than the larger units. These jitter levels are unacceptable for some scientific instruments and need to be compensated. In the case of line-of-sight type instruments, the attitude jitter can be mitigated by incorporating a fast steering mirror into the system. To take full advantage of these devices, the spacecraft attitude must be measured at sufficiently high bandwidth, well beyond what is commonly provided by inertial reference units. Various ways to obtain higher …

Dominant Wave Directions And Significant Wave Heights From Synthetic Aperture Radar Imagery Of The Ocean, Lisa M. Zurk, William J. Plant

Electrical and Computer Engineering Faculty Publications and Presentations

We show that quasi-linear theory accounts for dominant wave directions observed in synthetic aperture radar (SAR) imagery of the ocean for range-to-velocity (R/V) ratios up to 70 s. We also show that when used in combination with Alpers and Hasselmann's [1982] model of signal-to-noise ratios in SAR imagery, this theory yields significant wave heights in good agreement with those actually observed. We have found that the apparent dominant wave direction in SAR imagery taken at a 45° incidence angle can differ from the true wave direction by as much as 40° under certain conditions. To understand such differences, we simulated …

Estimation Of Pore Diameter For Intraparticle Fluid Flow In Hidisperse Porous Chromatographic Particles, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A quantitative method is developed and presented for estimating the mean pore diameter, d(pore), that could allow intraparticle fluid flow in the macroporous region of adsorbent particles with a bidisperse porous structure packed in a column. The method is used to estimate the value of d(pore) that is required to obtain specified values of the fraction, F, of the column superficial fluid velocity that is flowing through the macroporous region of the adsorbent particles and the value of d(pore) that is required to obtain specified values of the intraparticle Peclet number, Pe(intra).

A Telescopic Approach To Modeling Leachate Dynamics And Migration At The St. Johns Landfill, Portland, Oregon, Thomas Stephen Lowry

Dissertations and Theses

The St. Johns Landfill is a 225-acre site that lies near the confluence of the Columbia and Willamette Rivers, in the North Portland Industrial District of Portland, Oregon. A slough system surrounds the landfill on three sides with the fourth side adjacent to a shallow lake. The landfill first opened in 1930 when it was operated as an open dump. It operated as an open dump until 1969 when it was converted to a sanitary landfill, employing daily cover and compaction. The landfill was closed in 1991.

The landfill sits directly on top of a thick layer of silty overbank …

Numerical Simulation Of Contaminated Sediment Transport In The Upper Columbia Slough System, Binghong Wu

Dissertations and Theses

An integrated modeling system has been developed to simulate sediment and contaminated sediment transport in the Upper Columbia Slough System during the Flood of 1996. The modeling system consists of a hydrodynamic model, a sediment transport model, and a contaminant transport model. The hydrodynamic model predicts the Slough flow dynamics and sediment transporting power; the sediment transport model predicts flow-induced sediment transport; and the contaminant transport model predicts the migration of contaminated sediments in the Slough system.

The Upper Columbia Slough modeling system is characterized by its recognition of the complex interplay of Slough hydrology, hydrodynamics, sediment transport, contaminant transport. …

A Simplified Approach To Reduce Blocking And Ringing Artifacts In Transform-Coded Images, Jianping Hu

Dissertations and Theses

Presently Block-based Discrete Cosine Transform (BDCT) image coding techniques are widely used in image and video compression applications such as JPEG and MPEG. At a moderate bit rate, BDCT is usually a quite satisfactory solution to most of practical coding applications. However, for high rate compression it produces noticeable blocking and ringing artifacts in the decompressed image. It has been an active research area for a decade for reducing these artifacts. In this thesis, a novel post-processing algorithm is proposed to remove the blocking and ringing artifacts at low bit rate. It is non-iterative and uses both spatial and transform …

Optical Spray Paint Optimization System And Method, Richard J. Klein Ii, Douglas L. Sevey, Alireza Badakhshan, Ricky J. Bauer

Patents (University of Northern Iowa)

An optical spray paint optimization system can be removably mounted to a spray paint gun, thus enhancing the ability of the user to guide the direction of the spray and also locate the nozzle at an optimum spray distance from the surface being painted. The preferred apparatus uses a diode laser, a beam splitter and a reflecting mirror to generate a reference beam and a gauge beam. The reference beam propagates in a fixed forward direction, but the direction of the gauge beam is adjustable by adjusting the attitude of the reflecting mirror. The reference beam and the gauge beam …

Ccfss Technical Bulletin February 1997, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.

Acuta Enews February 1997, Vol.26, No. 2

ACUTA Newsletters

In This Issue

Call for Nominations for 1997-98

ACUTA Board of Directors

Effective Presentations

Board Report

Welcome New Members

Is It a Virus- Or a Hoax?

Vendor Liaison Committee

DC at a Glance

FCC Designates Wireless Spectrum for School

FCC Extends Campus Station License Terms

Coming Soon to Your IXC: 10XXX Changes

Evaluation Of Bridge Abutment Capacity And Stiffness During Earthquakes, Rakesh K. Goel, Anil K. Chopra

Civil and Environmental Engineering

The “actual” capacity and stiffness values of the abutment‐soil systems at the US 101/Painter Street Overpass, determined from its earthquake motions, are used to investigate how abutment stiffness varies during earthquakes and to evaluate current modeling procedures. It is found that the “actual” abutment stiffness may be significantly different during different phases of the shaking and decreases significantly as the abutment deformation increases. The CALTRANS modeling procedure leads to a good estimate of the transverse abutment stiffness and capacity. However, this procedure may overestimate the normal abutment stiffness and capacity by a factor of over two, indicating that the assumed …

Bipolar/Cmos (Weak Inversion) Rail-To-Rail Constant-G M Input Stage, Vladimir I. Prodanov, Michael M. Green

Electrical Engineering

A rail-to-rail constant-g_m input stage suitable for bipolar or weak inversion CMOS implementation is presented. To achwe rail-to rail operation, two complementary differential pairs driven in parallel are used. To guarantee constant net transconductance each differential pair is augmented with a suitable biasing circuit. The biasing circuits are implemented without current mirrors, which results in low sensitivity to process variations and potentially higher bandwidth.

Solar Heating Of Swimming Pools: A Question & Answer Primer, Florida Solar Energy Center, Charles Cromer

FSEC Energy Research Center®

Solar pool heating is one of the most economically attractive solar technologies in Florida today. If you are interested in heating your pool, or can no longer afford heating it with fossil fuel alone, consider installing a solar pool heater.

The following information helps answer the most frequently asked questions concerning solar pool heating in Florida. Keep in mind that much of this information is "rule of thumb"; your individual situation, if analyzed in detail, may differ somewhat from the general application. A more detailed analysis of pool systems is provided by the publications listed in the bibliography.

Streamflow Simulation: A Nonparametric Approach, Ashish Sharma, David G. Tarboton, Upmanu L. Lall

Civil and Environmental Engineering Faculty Publications

In this paper kernel estimates of the joint and conditional probability density functions are used to generate synthetic streamflow sequences. Streamflow is assumed to be a Markov process with time dependence characterized by a multivariate probability density function. Kernel methods are used to estimate this multivariate density function. Simulation proceeds by sequentially resampling from the conditional density function derived from the kernel estimate of the underlying multivariate probability density function. This is a nonparametric method for the synthesis of streamflow that is data-driven and avoids prior assumptions as to the form of dependence (e.g., linear or nonlinear) and the form …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 13, Number 2, February 1997, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A twelve page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Teaching Electromagnetic Field Theory Using Differential Forms, Karl F. Warnick, Richard H. Selfridge, David V. Arnold

Faculty Publications

The calculus of differential forms has significant advantages over traditional methods as a tool for teaching electromagnetic (EM) field theory. First, films clarify the relationship between field intensity and flux density, by providing distinct mathematical and graphical representations for the two types of fields. Second, Ampere's and Faraday's laws obtain graphical representations that are as intuitive as the representation of Gauss's law. Third, the vector Stokes theorem and the divergence theorem become special cases of a single relationship that is easier for the student to remember, apply, and visualize than their vector formulations. Fourth, computational simplifications result from the use …

Solar Hot Water Energy And Cost Savings For Typical Florida Residential Installations, Florida Solar Energy Center, David L. Block

FSEC Energy Research Center®

The following table presents energy and cost savings for four typical Florida solar water heating systems. Exact savings by a consumer may vary as much as plus or minus 25 from these numbers for numerous reasons. These include hot water usage, storage tank type, thermostat settings, solar system size, collector placement and local weather conditions. Computer simulations were used to generate the energy data.

Experiments In Aggregating Air Ordnance Effectiveness Data For The Tacwar Model, James E. Parker

Theses and Dissertations

An interactive MS Access&trademark; based application that aggregates the output of the SABSEL model for input into the TACWAR model is developed. The application was developed following efforts to create a functional approximation of the SABSEL data using neural networks, statistical networks, and traditional statistical techniques. These approximations were compared to a look-up table methodology on the basis of accuracy, (RMSE

Sensitivity Of Availability Estimates To Input Data Characterization, Darren P. Durkee

Theses and Dissertations

Reliability analysts are often faced with the challenge of characterizing the behavior of system components based on limited data. Any insight into which model input data is most significant and how much data is necessary to achieve desired accuracy requirements will improve the efficiency and cost effectiveness of the data collection and data characterization processes. This thesis assesses potential significant factors in the probabilistic characterization of component failure and repair behavior with respect to the effect on system availability estimates. Potential factors were screened for significance utilizing fractional. factorial and Plackett-Burman experimental designs for several system models developed using an …

Determining The Economic Plausibility Of Dual Manifesting Reusable Launch Vehicles And Reusable Orbital Transfer Vehicles For The Replenishment Of Military Satellites, Crystal L. Evans

Theses and Dissertations

Currently, the Air Force launches military satellites on expendable launch vehicles to low earth orbit (LEO), and with the use of a chemical upper stage or an apogee kick motor, moves the satellite to a higher orbit. This launch procedure is extremely costly because it requires additional launch preparations, technology considerations, equipment, and fuel. Also, the additional mass of the chemical upper stage causes a larger, and thus more expensive, launch vehicle to be required. An economical alternative is to utilize reusable launch vehicles (RLVs) and reusable orbital launch vehicles (ROTVs). This concept could possibly achieve even greater savings if …

Applying Tabu Heuristic To Wind Influenced, Minimum Risk And Maximum Expected Coverage Routes, Mark R. Sisson

Theses and Dissertations

The purpose of this thesis is to provide Air Combat Command a method for determining the number of predator unmanned aerial vehicles (UAVs) required to cover a pre-selected target. Extending previous research that employs reactive TABU search methods for deterministic vehicle routing problems, this thesis incorporates wind effects that can significantly alter the travel times for any given scenario. Additionally, it accounts for possible attrition by introducing minimum risk route and expected number of target covered to the objective function. The results of the TABU search and subsequent Monte-Carlo simulation: gives the number of predator's required to cover a target …

Analysis Of Aircraft Sortie Generation With Concurrent Maintenance And General Service Times, Daniel V. Hackman

Theses and Dissertations

The primary objective of this study was to develop an analytical methodology for evaluating an aircraft sortie generation process. The process is modeled as a closed network of general service queues with a fork join node to model concurrent servicing. The model uses the Mean Value Analysis (MVA) algorithm and general queueing network analysis by decomposition to approximate network performance measures including resource utilization and the overall sortie generation rate. The results of the study show that the analytical approximation's accuracy decreases as server utilization increases. However, when server utilization is kept in realistic ranges, the approximation is very accurate. …

A Cost Impact Assessment Tool For Pfs Logistics Consulting, Angela P. Giddings

Theses and Dissertations

Response surface methodology (RSM) is used for optimality analysis of the cost parameters in mixed integer linear programming. This optimality analysis goes beyond traditional sensitivity and parametric analysis in allowing investigation of the optimal objective function value response over pre-specified ranges on multiple problem parameters. Design of experiments and least squares regression are used to indicate which cost parameters have the greatest impact on the optimal objective function value total cost-and to approximate the optimal total cost surface over the specified ranges on the parameters. The mixed integer linear programming problems of interest are the large-scale problems in supply chain …

Optimizing Airborne Area Surveillance Asset Placement, Douglas E. Fuller

Theses and Dissertations

Currently there is no automated planning tool for the optimum positioning of USAF area surveillance assets for a theater level campaign. This research seeks to find the optimum or near optimum placement of the limited USAF airborne surveillance assets against a theater level target set. The problem of finding the optimum orbit points can be modeled as a classic maximal covering location problem (MCLP). Operational constraints on the placement of surveillance aircraft can be handled by preprocessing the potential orbit points to eliminate infeasible orbit points. Heavy emphasis is placed on preprocessing the data to reduce problem size and hence …

Strength Of Flexural Members Using Structural Grade 80 Of A653 Steel (Web Crippling Tests), Shaojie Wu, Wei-Wen Yu, Roger A. Laboube

CCFSS Library (1939 - present)

This Third Progress Report summarizes the web crippling tests of 148 specimens and evaluates the test results along with an additional 114 web crippling tests which were reported in 1986 as part of a project on Design of Automotive Structural Components Using High-Strength Sheet Steels. The 148 web crippling tests conducted in this program are the part of the overall project on Strength of Flexural Members Using the Structural Grade 80 of ASTM A653 Steel (former ASTM A446 Grade E Steel). The objectives of the ongoing project are to study the strength and structural performance of flexural members as affected …

Residual Strength Of Equine Bone Is Not Reduced By Intense Fatigue Loading: Implications For Stress Fracture, R. B. Martin, V. A. Gibson, S. M. Stover, J. C. Gibeling, L. V. Griffin

Biomedical Engineering

Fatigue or stress fractures are an important clinical problem in humans as well as racehorses. An important question in this context is, when a bone experiences. fa!igue damage ~uring e~treme use, how much is it weakened compared to its original state? Since there are very ltmtted data on thts quesuon and stress fractures are common in racehorses, we sought to determine the effect of fatigue loading on the monotonic l:trength of equine cortical bone. Beams were machined from the dorsal, medial and lateral cortices of the third metacarpal bones of six thoroughbred racehorses. Beams from left and right bones were …

Ifn-Gamma, Igif, And Iddm., Nora Sarvetnick

Journal Articles: Regenerative Medicine

No abstract provided.