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Articles 173401 - 173430 of 198025

Full-Text Articles in Engineering

Introduction To Simulation/Optimization Modeling For Groundwater Containment Remediation And (B) Ramifications Of Applying S/O Modeling To Groundwater Containment Remediation, With Case Study Examples, Richard C. Peralta Jan 1997

Introduction To Simulation/Optimization Modeling For Groundwater Containment Remediation And (B) Ramifications Of Applying S/O Modeling To Groundwater Containment Remediation, With Case Study Examples, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Normal use of a simulation model to develop a groundwater extraction/injection strategy employs the following process: (1) specify management goals, (2) assume a pumping strategy, (3) simulate system response to the pumping strategy, (4) evaluate acceptability of the system responses, (5) repeat steps (2-4) as required. This is a trial and error approach that is unlikely to actually yield the best pumping strategy for complicated problems


Optimal System Design Of In-Situ Bioremediation Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta Jan 1997

Optimal System Design Of In-Situ Bioremediation Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

We present a simulation/optimization model combining optimization with BIOPLUME II simulation for optimizing in-situ bioremediation system design. In-situ bioremediation of contaminated groundwater has become widely accepted because of its cost-effective ability to achieve satisfactory cleanup. We use parallel recombinative simulated annealing to search for an optimal design and apply the BIOPLUME II model to simulate aquifer hydraulics and bioremediation. Parallel recombinative simulated annealing is a general-purpose optimization approach that has the good convergence of simulated annealing and the efficient parallelization of a genetic algorithm. This is the first time that parallel recombinative simulated annealing has been applied to groundwater management. …


Optimal In-Situ Bioremediation System Design Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta Jan 1997

Optimal In-Situ Bioremediation System Design Using Parallel Recombinative Simulated Annealing, Horng-Jer Shieh, Richard C. Peralta

Civil and Environmental Engineering Faculty Publications

Presented is a simulation/optimization (S/0) model combining optimization with BIOPLUME II simulation for optimizing in-situ bioremediation system design. The (S/0) model uses parallel recombinative simulated annealing to search for an optimal design and applies the BIOPLUME II model to simulate aquifer hydraulics and bioremediation. Parallel recombinative simulated annealing is a general-purpose optimization approach that has the good convergence of simulated annealing and the efficient parallelization of a genetic algorithm. We propose a two-stage management approach. The first stage design goal is to minimize total system cost (pumping/treatment, well installation and facility capital costs). The second stage design goal is to …


Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih Jan 1997

Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

We provide efficient parallel algorithms for the minimum separation, offset range, and optimal offset problems for single-layer channel routing. We consider all the variations of these problems that are known to have linear- time sequential solutions rather than limiting attention to the "river-routing" context, where single-sided connections are disallowed. For the minimum separation problem, we obtain O(lgN) time on a CREW PRAM or O(lgN / lglgN) time on a (common) CRCW PRAM, both with optimal work (processor- time product) of O(N), where N is the number of terminals. For the offset range problem, we obtain the same time and processor …


Monotonic Tests Of Cold-Formed Steel Shear Walls With Openings, American Iron And Steel Institute Jan 1997

Monotonic Tests Of Cold-Formed Steel Shear Walls With Openings, American Iron And Steel Institute

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

No abstract provided.


Femtosecond Photoemission Study Of Ultrafast Electron Dynamics On Cu(100), J. Cao, Y. Gao, R. J. D. Miller, Hani E. Elsayed-Ali, D. A. Mantell Jan 1997

Femtosecond Photoemission Study Of Ultrafast Electron Dynamics On Cu(100), J. Cao, Y. Gao, R. J. D. Miller, Hani E. Elsayed-Ali, D. A. Mantell

Electrical & Computer Engineering Faculty Publications

The energy dependence of the relaxation of photoexcited electrons in copper was measured using femtosecond time-resolved photoemission spectroscopy to within 0.3 eV above the Fermi level. By performing lifetime measurements under different surface conditions, several surface dynamical processes were investigated. In particular, an anomalous long lifetime feature, which cannot be explained with Fermi-liquid theory, was observed in the lifetime-energy curve. This feature was found originating from the photoexcitation of the strongly localized Cu 3d electrons. ©1997 American Physical Society


Soot In Coal Combustion Systems, Thomas H. Fletcher, Jinliang Ma, Jim Rigby, Alexander L. Brown, Brent W. Webb Jan 1997

Soot In Coal Combustion Systems, Thomas H. Fletcher, Jinliang Ma, Jim Rigby, Alexander L. Brown, Brent W. Webb

Faculty Publications

Soot is generated from coal when volatile matter, tar in particular, undergoes secondary reactions at high temperatures. A description of soot in coal flames allows better calculations of radiative transfer and temperatures in near-burner regions, which in turn allows more accurate predictions of NOx formation in coal-fired furnaces. Experiments are reviewed that examine the formation, agglomeration and properties of coal-derived soot, including pyrolysis experiments and combustion experiments. This review includes the types of experiments performed, the soot yields obtained, the size of the soot particles and agglomerates, the optical properties of soot, the relationship between coal-derived soot and soot …


Radar Backscatter Measurement Accuracy For A Spaceborne Pencil-Beam Wind Scatterometer With Transmit Modulation, David G. Long, Michael W. Spencer Jan 1997

Radar Backscatter Measurement Accuracy For A Spaceborne Pencil-Beam Wind Scatterometer With Transmit Modulation, David G. Long, Michael W. Spencer

Faculty Publications

Scatterometers are remote sensing radars designed to measure near-surface winds over the ocean. The difficulties of accommodating traditional fan-beam scatterometers on spacecraft has lead to the development of a scanning pencil-beam instrument known as SeaWinds. SeaWinds will be part of the Japanese Advanced Earth Observing Satellite II (ADEOS-II) to be launched in 1999. To analyze the performance of the SeaWinds design, a new expression for the measurement accuracy of a pencil-beam system is required. In this paper the authors derive a general expression for the backscatter measurement accuracy for a pencil-beam scatterometer which includes the effects of transmit signal modulation …


Turbulence Modeling Of The Toroidal Wall Heat Load Due To Shear Flows Over Cavities In The Neutral Gas Blanket Divertor Regime, George Vahala, Linda L. Vahala, Joseph Morrison Jan 1997

Turbulence Modeling Of The Toroidal Wall Heat Load Due To Shear Flows Over Cavities In The Neutral Gas Blanket Divertor Regime, George Vahala, Linda L. Vahala, Joseph Morrison

Electrical & Computer Engineering Faculty Publications

Heat loads to the target plate in reactor tokamaks are estimated to be orders of magnitude higher than those that can be withstood by known materials. In regimes of plasma detachment, there is strong evidence that plasma recombination occurs near the divertor plate, leading to a cold neutral gas blanket. Because of the strong coupling between the plasma and the neutrals within the divertor region, there is significant neutral flows along field lines up to Mach 1.2 and Reynolds numbers over 1000. The effects of three dimensional (3D) neutral turbulence within the gas blanket on heat deposition to the toroidal …


An Exploratory Study: Reading And Spatial Visualization Ability As Predictors Of Success For Technical Drawing, Eldon Bruce Swanson Jan 1997

An Exploratory Study: Reading And Spatial Visualization Ability As Predictors Of Success For Technical Drawing, Eldon Bruce Swanson

Dissertations and Theses @ UNI

If one were to open a technical drawing book, the reader could make the observation that the book was "written" and "read" in two languages--the English language and the universal graphic language. The technical drawing is presented in the context of these two languages: written statements accompanied by their graphical translations. The two seemingly symbiotic languages are synergistically integrated in technical drawing.

The problem of this exploratory study was to determine the strength of the bivariate correlational relationships between students' assessed spatial visualization ability and their reading ability to their assessed achievement in technical drawing. Further, the problem of the …


New Objective Classification System For Nuclear Opacification, Donald D. Duncan, O. B. Shukla, Sheila West, Oliver D. Schein Jan 1997

New Objective Classification System For Nuclear Opacification, Donald D. Duncan, O. B. Shukla, Sheila West, Oliver D. Schein

Electrical and Computer Engineering Faculty Publications and Presentations

We have developed an autonomous objective classification scheme for degree of nuclear opacification. The algorithm was developed by using a series of color 35-mm slides acquired with a Topcon photo slit-lamp microscope and use of standard camera settings. The photographs were digitized, and first, and second-order gray-level statistics were extracted from within circular regions of the nucleus. Classifications of severity were performed by using these features as input to a neural network. Training versus classification performance was tested by using photographs of different eyes, and test/retest classification reproducibility was evaluated by using paired photographs of the same eyes. We demonstrate …


Observation And Investigation Of The Ferrielectric Subphase With High Qt Parameter, Yuri Panarin, O. Kalinovskaya, J.K. Vij, J.W. Goodby Jan 1997

Observation And Investigation Of The Ferrielectric Subphase With High Qt Parameter, Yuri Panarin, O. Kalinovskaya, J.K. Vij, J.W. Goodby

Articles

Dielectric relaxation processes in an antiferroelectric liquid crystal (AFLC) have been investigated over a wide range of frequencies from 1 Hz to 1 GHz. The AFLC under investigation possesses a variety of different ferrielectric, ferroelectric, and antiferroelectric phases. Dielectric and polarization measurements under direct bias voltage have been made with a view to clarifying the origin of the high-temperature ferrielectric phase, which appears between the AF and smectic-C phases. This phase is assigned to an unstable ferrielectric phase with qT parameter greater than 1/2 (according to the Ising model) or a doubly modulated incommensurate phase (according to the expanded Landau …


Investigation Of The Ferrielectric Subphase With Qt>1/2 Under Bias Voltage, Yuri Panarin, O.E. Kalinovskaya, J.K. Vij Jan 1997

Investigation Of The Ferrielectric Subphase With Qt>1/2 Under Bias Voltage, Yuri Panarin, O.E. Kalinovskaya, J.K. Vij

Articles

The properties of Femelectric phase with qT > 112 have been investigated using broadband dielectric spectroscopy and polarization measurements under the bias voltage. The field -induced sequence of phase transitions is found to be different fiom those of the conventional femelectric phases with qTS 112


A Study Of Antiferroelectric Liquid Crystals Using The Pyroelectric Technique, J.W. O'Sullivan, Yuri Panarin, J.K. Vij, A.J. Seed, M. Hird, J.W. Goodby Jan 1997

A Study Of Antiferroelectric Liquid Crystals Using The Pyroelectric Technique, J.W. O'Sullivan, Yuri Panarin, J.K. Vij, A.J. Seed, M. Hird, J.W. Goodby

Articles

Antiferroelectric liquid crystals are studied using the pyroelecmc technique. The effects of temperature and applied voltage on the pyroelectric signal are examined. The pyroelecmc signal can detect phase changes that occur due to temperature and bias voltage. A high temperature femelecmc phase FiLC is found and the stability of this phase under different bias voltages is examined


Observation And Investigation Of The Ferrielectric Subphase With Qt>1/2, Yuri Panarin, O. Kalinovskaya, J. K. Vij Jan 1997

Observation And Investigation Of The Ferrielectric Subphase With Qt>1/2, Yuri Panarin, O. Kalinovskaya, J. K. Vij

Articles

The high-temperature femelectric phase with qT > 1/2 has been found to exist in a antiferroelectric liquid crystal. This phase has been identified using dielectric spectroscopy and conoscopy.


Effect Of Variable-Ph Landfill Leachate On A Carbonate Rock Aggregate, William L. Niemann, Allen W. Hatheway Jan 1997

Effect Of Variable-Ph Landfill Leachate On A Carbonate Rock Aggregate, William L. Niemann, Allen W. Hatheway

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Carbonate rock aggregate is commonly used as drainage stone in leachate collection systems of RCRA Subtitle D landfills. U.S. EPA technical guidance for waste containment facilities states that excessive carbonate in drainage stone may result in dissolution and clogging at sites of reprecipitation (Daniel and Koerner, 1993, p. 197). Unfortunately, this theoretical concern does not appear to be confirmed by any experimental evidence with typical landfill leachate or documented instances of clogging at typical Subtitle D landfills. This paper describes a practical laboratory experiment that measured the effects of landfill leachate - maintained at three distinct pH levels - on …


Constrained Moments Simulation Of Healthcare Capital Acquisitions, A. Narsing, Samuel Frimpong, J. Whiting Jan 1997

Constrained Moments Simulation Of Healthcare Capital Acquisitions, A. Narsing, Samuel Frimpong, J. Whiting

Mining Engineering Faculty Research & Creative Works

Summary form only as given. Two analytical techniques which evaluate capital acquisitions in healthcare are the method of generating system moments and Monte Carlo simulation. Generating system moments enables the user to determine an estimate of the expected cost from a user-supplied function. Furthermore, the user can determine, from a variance component analysis, the sensitivity of the user-supplied function to marginal changes in the random variables by expanding the function about its mean using the Taylor series expansion to the second order. Calculating the magnitude of partial derivatives of each random variable with respect to the user-supplied function indicates the …


Scaling Parallels In The Non-Debye Dielectric Relaxation Of Ionic Glasses And Dipolar Supercooled Liquids, David L. Sidebottom, Peter F. Green, Richard K. Brow Jan 1997

Scaling Parallels In The Non-Debye Dielectric Relaxation Of Ionic Glasses And Dipolar Supercooled Liquids, David L. Sidebottom, Peter F. Green, Richard K. Brow

Materials Science and Engineering Faculty Research & Creative Works

We compare the dielectric response of ionic glasses and dipolar liquids near the glass transition. Our work is divided into two parts. In the first section we examine ionic glasses and the two prominent approaches to analyzing the dielectric response. The conductivity of ion-conducting glasses displays a power law dispersion σ(ω)∞ωn, where n≈0.67, but frequently the dielectric response is analyzed using the electrical modulus M*(ω) = 1/ε*(ω), where ε*(ω) = ε(ω) - iσ(ω)/ω is the complex permittivity. We reexamine two specific examples where the shape of M*(ω) changes in response to changes in (a) temperature and (b) ion concentration, to …


Ferroelectric Films As A Fashion Object For Polycrystalline Film Investigation, V. Petrovsky, Harlan U. Anderson, M. Shumsky Jan 1997

Ferroelectric Films As A Fashion Object For Polycrystalline Film Investigation, V. Petrovsky, Harlan U. Anderson, M. Shumsky

Materials Science and Engineering Faculty Research & Creative Works

BaxSr1-xTiO3 (BST), PbZrxTi1-xO3 (PZT) and two-layer PZT-BST films were prepared on Pt, Si(100) and Si(111) substrates by a sol-gel method. XRD analysis shows that the PZT films on the Si(111) substrates tended to be preferentially oriented in the (110) direction. The nondestructive readout of the state of ferroelectric polarization was investigated by three methods: the pyroelectric effect, the non-linearity of the capacitance and the field effect in MOS structures. It is shown that all three methods provide nondestructive readout, and the choice between them depends on the intended use.


Chemical Durability Of Lead-Oxide-Based, Thick-Film Binder Glasses, Douglas M. Mattox, Joshua H. Robinson Jan 1997

Chemical Durability Of Lead-Oxide-Based, Thick-Film Binder Glasses, Douglas M. Mattox, Joshua H. Robinson

Materials Science and Engineering Faculty Research & Creative Works

Lead-oxide-bearing glasses are incompatible with aluminum nitride metallization's, and federal legislation is recommending their replacement in thick-film electronics and labeling. To evaluate alternatives, the benchmark chemical durability's of the lead borosilicate and lead aluminate thick-film binder glasses have been determined. Aluminum oxide (Al2O3) benefits water durability moderately, acid durability substantially, and basic durability indistinguishably. The rate of attack in water is approximately two orders of magnitude greater than for soda-lime glass. The thermal contractions of the glasses are compatible. An apparent, spontaneous phase separation in the Al2O3-free glass is suppressed by Al2O3 that is included as a batch component.


Lyceum: A Multi-Protocol Digital Library Gateway, Ming-Hokng Maa, Michael L. Nelson, Sandra L. Esler Jan 1997

Lyceum: A Multi-Protocol Digital Library Gateway, Ming-Hokng Maa, Michael L. Nelson, Sandra L. Esler

Computer Science Faculty Publications

Lyceum is a prototype scalable query gateway that provides a logically central interface to multi-protocol and physically distributed, digital libraries of scientific and technical information. Lyceum processes queries to multiple syntactically distinct search engines used by various distributed information servers from a single logically central interface without modification of the remote search engines. A working prototype (http://www.larc.nasa.gov/lyceum/) demonstrates the capabilities, potentials, and advantages of this type of meta-search engine by providing access to over 50 servers covering over 20 disciplines.


Determining The Viability Of The "Rated Axle Load Enhancement System" For Concrete Pavement, Chih-Jen Lee, Charles D. Sutton, Thomas D. White Jan 1997

Determining The Viability Of The "Rated Axle Load Enhancement System" For Concrete Pavement, Chih-Jen Lee, Charles D. Sutton, Thomas D. White

JTRP Technical Reports

Concrete pavements in large part are designed as flat slabs although in the past they have included thickened edges. Thickened edge slabs are used today where positive load transfer for some reason cannot be provided. The Rated Axle Load Enhancement (RALE) system concept involves the use of longitudinal stems to stiffen the concrete slab. A close analogy is that of a wide double or quadruple "T" beam. The stems may be rectangular or trapezoidal.

In this study, RALE systems with two and four rectangular stems as well as plain concrete slabs were analyzed using the finite element method (FEM). The …


Indot Multimedia Applications Prototype Development, Bob G. Mccullouch Jan 1997

Indot Multimedia Applications Prototype Development, Bob G. Mccullouch

JTRP Technical Reports

Multimedia technologies open a new data set for DOT organizations. By adding pictures, sounds, animation, and video, new computer applications can be developed that will bring many benefits. This project investigated the utilization of multimedia into DOT operations. Applications were developed in three different topical areas: Employee Information or Orientation, a Bridge Plan Reading course, and a Construction Equipment utilization prototype. The first two are fully developed implementable tools that will be utilized by INDOT. These developments provide insight into how multimedia can be a useful tool for training and providing performance support to DOT employees. Other tools can be …


An Evaluation Of The Cost Effectiveness Of The Hoosier Helper Program And Framework For The Design Of Its Optimal System Configuration, Phase 1, Steven P. Latoski, Raktim Pal, Kumares C. Sinha Jan 1997

An Evaluation Of The Cost Effectiveness Of The Hoosier Helper Program And Framework For The Design Of Its Optimal System Configuration, Phase 1, Steven P. Latoski, Raktim Pal, Kumares C. Sinha

JTRP Technical Reports

This research provides a benefit-cost analysis for each of two distinct Hoosier Helper operating scenarios: daytime patrol and 24-hour patrol. The computation of agency cost involves an aggregation of equivalent annual investment cost, employee salaries and fringe benefit, overhead cost, and maintenance cost for Hoosier Helper. The following components comprise the estimation of Hoosier Helper benefits: non-recurrent congestion delay savings, secondary crash reduction, and vehicle operating cost savings. The results of an analysis of over two thousand evaluations from motorists assisted by Hoosier Helper are also presented.


Moment-Rotation Relationship For Unified Auto-Stress Design Of Continuous-Span Bridge Beam And Girders, Donald W. White, J. A. Ramirez, Karl E. Barth Jan 1997

Moment-Rotation Relationship For Unified Auto-Stress Design Of Continuous-Span Bridge Beam And Girders, Donald W. White, J. A. Ramirez, Karl E. Barth

JTRP Technical Reports

This report summarizes the development and trial application of simplified moment-rotation relationships for inelastic design of continuous-span beam and girder bridges. The research described within involves the execution of a reasonably comprehensive set of finite element parametric studies to fill in knowledge gaps in the available experimental data pertaining to the hogging moment-plastic rotation behavior of steel and composite steel-concrete bridge girders. Based on these studies, relationships have been developed for the moment-plastic rotation behavior at the pier sections in these types of bridges. The moment-rotation model is validated against available experimental data, several focused new experimental tests, and current …


Design And Implementation Of High-Radix Arithmetic Systems Based On The Sdnr/Rns Data Representation, Paul Whyte Jan 1997

Design And Implementation Of High-Radix Arithmetic Systems Based On The Sdnr/Rns Data Representation, Paul Whyte

Theses : Honours

This project involved the design and implementation of high-radix arithmetic systems based on the hybrid SDNRIRNS data representation. Some real-time applications require a real-time arithmetic system. An SDNR/RNS arithmetic system provides parallel, real-time processing. The advantages and disadvantages of high-radix SDNR/RNS arithmetic, and the feasibility of implementing SDNR/RNS arithmetic systems in CMOS VLSI technology, were investigated in this project. A common methodological model, which included the stages of analysis, design, implementation, testing, and simulation, was followed. The combination of the SDNR and RNS transforms potential complex logic networks into simpler logic blocks. It was found that when constructing a SDNRIRNS …


A Design In Interfacing The Mc68hc11 To The Amd Am29f010 Flash Memory Chips, David H. Hands Jan 1997

A Design In Interfacing The Mc68hc11 To The Amd Am29f010 Flash Memory Chips, David H. Hands

Theses : Honours

In many environments, motion, vibration and contamination to the Secondary Storage Devices such as hard drives can cause data to become unreadable or even lost. Elimination of these types of magnetic drives, incorporating its replacement with a Solid State Memory Storage Device would provide an invaluable solution for these type of environments. If a secondary storage system could replace these electro-mechanical disk drive systems incorporating a Solid State Secondary Storage Device such as the Flash Memory Integrated Chips, an increase in the speed of reading from milli-seconds to nano-seconds would transpire as well as providing a robust Secondary Storage Device. …


Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White Jan 1997

Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White

Faculty Publications

No abstract provided.


Electrowinning Of Nonnoble Metals With Simultaneous Hydrogen Evolution At Flow-Through Porous Electrodes Iii. Time Effects, Mahmoud M. Saleh, John W Weidner, Bahgat E. El-Anadouli, Badr G. Ateya Jan 1997

Electrowinning Of Nonnoble Metals With Simultaneous Hydrogen Evolution At Flow-Through Porous Electrodes Iii. Time Effects, Mahmoud M. Saleh, John W Weidner, Bahgat E. El-Anadouli, Badr G. Ateya

Faculty Publications

The electrowinning of zinc from a recirculating alkaline zincate solution at a flow-through porous electrode was investigated. Experimental results were obtained to test the predictions of a mathematical model. The effects of electrolyte flow rate, cell current, and electrode thickness on the concentration-time relations and coulombic efficiency-time relations were studied. The experimental results show that the highest recovery rate was obtained at both high flow rates and cell currents. There is, however, a practical limit for increasing both the cell current and the electrolyte flow rate. Reasonable agreement between the model predictions and experimental results was obtained. A case study …


Ellipsometric And Raman Spectroscopic Study Of Thermally Formed Films On Titanium, E. Hristova, Lj. Arsov, Branko N. Popov, Ralph E. White Jan 1997

Ellipsometric And Raman Spectroscopic Study Of Thermally Formed Films On Titanium, E. Hristova, Lj. Arsov, Branko N. Popov, Ralph E. White

Faculty Publications

Thermal films on titanium surfaces were formed by heating titanium samples in air at atmospheric pressure. The optical constants, thickness, and structure of the formed films at various temperatures and times of heating were investigated by ellipsometry and Raman spectroscopy. The complex index of refraction and the thickness of generated films were determined by comparing the experimental loci and obtained by ellipsometric measurements with theoretical computed vs. curves. It was found that the thickness in homogeneity and porosity of formed films increase with increasing temperature and the duration of the thermal treatment. Beyond a certain critical temperature, the appearance of …