Engineering Commons^™

Nuclear Criticality Analyses Of Separations Processes For The Transmutation Fuel Cycle, William Culbreth, Pang Tao, Denis Beller

Separations Campaign (TRP)

The separation and partitioning of used commercial reactor fuel is a vital component of any reprocessing or transmutation strategy. To process the high actinide fuels required for a transmutation effort, the Chemical Technology Division (CMT) at Argonne National Laboratory (ANL) is developing a pyrochemical separations process. Currently, this work is being done via small experiments. While this is more than sufficient to develop the technologies required to process actinide-bearing fuels, it does not allow for the direct investigation of criticality concerns that would be present in larger systems. As the volume of waste to be treated increases, a higher probability …

A Dynamic Simulation Model Of Beach Sand Replenishment: A Case Study Of Santa Barbara, California, David Turbow, Steve Norwick, Sajjad Ahmad

Civil and Environmental Engineering and Construction Faculty Research

Sediment deprivation from dam installments contributes to beach erosion yet the underlying physical and economic factors linking them together have traditionally been isolated during regional planning. In order to gain a better understanding of the behavior of a managed beach system, a dynamic simulation model was developed incorporating physical and monetary factors influencing the amount of available beach sand. The Santa Barbara littoral cell was chosen as a case study to evaluate the feasibility of beach preservation goals under scenarios in which annual sand replenishment funding, sand prices, or sediment recovery from behind dams were limiting factors to available beach …

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

Fuels Campaign (TRP)

The Transmutation Research Program requires the incorporation of non-fertile actinides into the fuel matrix for the transmuter blanket. One of three currently proposed candidate matrices for the transmuter blanket is a metallic alloy fuel matrix. Metallic fuels are an outstanding candidate for a transmutation fuel due to excellent irradiation performance and ease of fabrication. However, including a volatile constituent during fabrication of these fuel pins presents a challenge. High vapor pressure actinides, particularly americium, are susceptible to rapid vaporization and transport using traditional metal fuel casting processes. As a result, only a fraction of the desired charge is incorporated into …

A Personel Note, Leopold B. Felsen

Turkish Journal of Electrical Engineering and Computer Sciences

No abstract provided.

Iterative Solution Of Field Problems With A Varying Physical Parameter, Anton G. Tijhuis, Martijn C. Van Beurden, A. Peter M. Zwamborn

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, linear field problems with a varying physical parameter are solved with the conjugate-gradient FFT method and a dedicated extrapolation procedure for generating the initial estimate. The scheme is formulated and illustrated for two simple example problems. The importance of the choice of the stop criterion and the step size are demonstrated for the case of a straight thin-wire segment. A brief summary is given of the applications that have appeared in the open literature until now, and actual three-dimensional scattering problems for a rectangular conducting plate and an inhomogeneous, dispersive dielectric body are discussed. Finally, the case …

Network--Oriented Modeling Of Radiating Electromagnetic Structures, Peter Russer

Turkish Journal of Electrical Engineering and Computer Sciences

The application of network-oriented modeling for radiating electromagnetic structures is investigated. Network methods are applied to the field problem using the segmentation technique and by specifying canonical Foster representations as compact models of reciprocal linear lossless electromagnetic structures. Connection between different subdomains is obtained via connection circuits exhibiting only ideal transformers. In the case of radiating structures, the complete structure is embedded into a sphere and the field outside the sphere is expanded into orthogonal spherical TM- and TE- waves. For each radiation mode a Cauer canonic circuit representation is given.

Novel Time Domain Radiowave Propagators For Wireless Communication Systems, Funda Akleman, M. O. Özyalçin, Levent Sevgi̇

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, novel time domain wave propagators are used in path loss calculations for macro and micro cell coverage planning in wireless communication systems. Both Transmission Line Matrix (TLM) and Finite-Difference Time-Domain (FDTD) based propagators, which were introduced recently and validated and verified on different canonical propagation scenarios, are used for this purpose. Examples are chosen both in rural and urban areas, where two propagators are compared with each other. Excellent agreement between the results obtained via two propagators is presented. The results presented here are very encouraging and these propagators are shown to be powerful tools for not …

Floquet Wave Diffraction Theory For Tapered Planar Strip Array Green's Function, F. Capolino, F. Mariottini, S. Maci, L. B. Felsen

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with the derivation and physical interpretation of a uniform high frequency representation of the Green's function for a planar phased array of dipoles. The asymptotic representation is based on Floquet wave edge diffraction theory herein extended to accommodate slowly varying tapered amplitude illumination with possible inclusion of dipole amplitudes that tend to zero at the edge. The phased array is assumed to be infinite with uniform amplitude excitation in the z-direction but finite and amplitude-tapered in the x-direction. This geometry permits study of diffraction phenomena occurring at the tapered edge of a rectangular array when the observation …

An Exact Line Integral Representation Of The Po Radiation Integral From A Flat Perfectly Conducting Surfaces Illuminated By Elementary Electric Or Magnetic Dipoles, Matteo Albani, Stefano Maci

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a line integral representation for the PO radiation integral from a flat perfectly conducting surface, illuminated by an arbitrary oriented elementary either electric or magnetic dipole, is presented. No restriction is imposed on the position of the source and of the observation point. The main application of this result is the acceleration of the numerical PO integration for electrically large surfaces. The formulation is based on the application of the equivalence principle to a projecting surface which allows the analytical evaluation in closed form of one of the two-fold surface integral which define the radiated field at …

Modal Predicates And Coequations, Alexander Kurz, Jiří Rosický

Engineering Faculty Articles and Research

We show how coalgebras can be presented by operations and equations. This is a special case of Linton’s approach to algebras over a general base category X, namely where X is taken as the dual of sets. Since the resulting equations generalise coalgebraic coequations to situations without cofree coalgebras, we call them coequations. We prove a general co-Birkhoff theorem describing covarieties of coalgebras by means of coequations. We argue that the resulting coequational logic generalises modal logic.

Object Persistence And Availability In Digital Libraries, Michael L. Nelson, B. Danette Allen

Computer Science Faculty Publications

We have studied object persistence and availability of 1,000 digital library (DL) objects. Twenty World Wide Web accessible DLs were chosen and from each DL, 50 objects were chosen at random. A script checked the availability of each object three times a week for just over 1 year for a total of 161 data samples. During this time span, we found 31 objects (3% of the total) that appear to no longer be available: 24 from PubMed Central, 5 from IDEAS, 1 from CogPrints, and 1 from ETD.

Federated Searching Interface Techniques For Heterogeneous Oai Repositories, Xiaoming Liu, Kurt Maly, Mohammad Zubair, Qiaoling Hong, Michael L. Nelson, Frances Knudson, Irma Holtkamp

Computer Science Faculty Publications

Federating repositories by harvesting heterogeneous collections with varying degrees of metadata richness poses a number of challenging issues: (1) how to address the lack of uniform control for various metadata fields in terms of building a rich unified search interface, and (2) how easily new collections and freshly harvested data in existing repositories can be incorporated into the federation supporting a unified interface? This paper focuses on the approaches taken to address these issues in Arc, an Open Archives Initiative compliant federated digital library. At present Arc contains over 1M metadata records from 75 data providers from various subject domains. …

Atomic Hydrogen Cleaning Of Inp(100): Electron Yield And Surface Morphology Of Negative Electron Affinity Activated Surfaces, M. A. Hafez, H. E. Elsayed-Ali

Electrical & Computer Engineering Faculty Publications

Atomic hydrogen cleaning of the InP(100) surface has been investigated using quantitative reflection high-energy electron diffraction. The quantum efficiency of the surface when activated to negative electron affinity was correlated with surface morphology. The electron diffraction patterns showed that hydrogen cleaning is effective in removing surface contaminants, leaving a clean, ordered, and (2×4)-reconstructed surface. After activation to negative electron affinity, a quantum efficiency of ∼6% was produced in response to photoactivation at 632 nm. Secondary electron emission from the hydrogen-cleaned InP(100)-(2×4) surface was measured and correlated to the quantum efficiency. The morphology of the vicinal InP(100) surface was investigated using …

Analysis Of Plastics In The Tyre Industry Using Fourier Transform Infrared Techniques, Differential Scanning Calorimetry And Softening Point Apparatus, Ching Ching Loh

Student Works (2000-2009)

The plastics in a tyre factory were investigated. The plastics were analysed by FTlR-transmission, FTI.R-ATR, softening point apparatus as well as a Differential Scanning Calorimeter. All the plastics were detected to be polyethene based with melting point range of 107 to 125°C. It was also observed that The FTIR transmission spectrum can be different from the FTIR-ATR spectrum. The FTIR-ATR spectrum gives a higher band intensity at longer wavelengths compared to the FTIR-Transmission spectrum. Interference fringes can be present in the FTlR transmission spectrum. In addition to the above, it was also found that the melting point of plastics obtained …

Adaptive Critic-Based Neural Network Controller For Uncertain Nonlinear Systems With Unknown Deadzones, Pingan He, Jagannathan Sarangapani, S. N. Balakrishnan

Electrical and Computer Engineering Faculty Research & Creative Works

A multilayer neural network (NN) controller in discrete-time is designed to deliver a desired tracking performance for a class of nonlinear systems with input deadzones. This multilayer NN controller has an adaptive critic NN architecture with two NNs for compensating the deadzone nonlinearity and a third NN for approximating the dynamics of the nonlinear system. A reinforcement learning scheme in discrete-time is proposed for the adaptive critic NN deadzone compensator, where the learning is performed based on a certain performance measure, which is supplied from a critic. The adaptive generating NN rejects the errors induced by the deadzone whereas a …

Upper Spokane River Model: Model Calibration, 1991 And 2000, Chris Berger, Robert Leslie Annear, Scott A. Wells

Civil and Environmental Engineering Faculty Publications and Presentations

The Washington Department of Ecology is interested in a water quality model for the Upper Spokane River system for use in developing Total Maximum Daily Loads (TMDLs). The goals of this modeling effort are to:

• Gather data to construct a computer simulation model of the Spokane River system including Long Lake Reservoir and the pools behind Nine Mile dam, Upper Falls dam and Upriver dam. • Ensure that the model accurately represents the system hydrodynamics and water quality (flow, temperature, dissolved oxygen and nutrient dynamics)

This report evaluates the model calibration and discusses issues relative to that calibration effort. …

Strained Quantum Well Heterostructure : Modeling And Simulation Of 980 Nm Laser, Yew Mun Hung

Student Works (2000-2009)

This thesis concerns the study of a strained quantum well laser diode emitting at wavelength of about 980 nm which is suitable for pumping Er³⁺ doped fiber amplifiers. The concept of a strained quantum well in the design of the active medium of the laser diode is discussed. A model is proposed that incorporates features of the physical structural factors and characteristics of the structure. The theoretical background linked directly to the simulation of the model is to provide calculations and derivations of the optical properties of the modeled structure. Theoretical calculations were made taking into account the variation of …

Impact Of Land Use Change On Hydroelectric Power Generation In Cameron Highlands, Fook Kun Choy

Student Works (2000-2009)

This study assesses the impact of land use changes on annual energy production of the hydro stations of Cameron Highlands Hydroelectric Scheme. Land use affects sediment load and streamflow of Sungai Telom and Sungai Bertam, which influences power generation and energy production of the several hydro stations in Cameron Highlands. Data of rainfall, streamflow, suspended sediment load, land use and energy output for the period 1964 to 1998 were collected, processed and analysed. Regression analysis, double mass curve method and double ratio technique were used in the assessment. The suspended sediment load and annual runoff of Sungai Telom and Sungai …

Assessment Of Pollution Load For Approved Eia Projects In The Industrial Sector (1988-1998) In Malaysia, Kok Sia Teng

Student Works (2000-2009)

It is generally recognised that developing countries lacked quantitative decision support tools in the formulation and implementation of pollution control measures necessary to abate environmental impacts associated with industrial development. Reliable and comprehensive simulation models are needed as basic tools for the quantification of industrial pollutant emission load, the assessment of their impacts on the environment as well as the evaluation of pollution control options. As a response to this inadequacy, this research project is conducted as an initial endeavor to use the World Bank's industrial pollution projection program Decision Support System for Integrated Pollution Control (DSS/IPC) for the assessment …

An Exploratory Study Of Internet Data Centres In Malaysia, Huai Peng Loh, Siew Hwa Tan

Student Works (2000-2009)

The explosion of Internet in Malaysia has spurred the growth of Internet Data Centres - a combination of Internet Service Providers, Information Technology Vendor Community and Telecommunication Service Providers providing co­location and managed services. These Internet Data Centres are targeting any organisations which have an internet strategy and which plan to outsource their IT infrastructures. This report aims to shed a light on the Malaysian Internet Data Centres, which are mainly concentrated in the Klang Valley. Readers will be able to gain insight into the target markets, infrastructure owned and services offered by the Internet Data Centres concerned. The report …

An Analytical Hierarchy Process (Ahp) Assessment Of The Iso 14001-Based Environmental Management System In The Oil And Gas Industry In Malaysia, Vijayalakshmi Benjamin Samuel

Student Works (2000-2009)

Today's business world is changing due to the ever-increasing consciousness for environmental protection and sustainable development. Customers are taking into account environmental considerations in their supplier selection, and are increasingly buying products with identifiable environmental attributes. In this study, the critical decision criteria, sub-criteria and benefits of the adoption and implementation of the ISO 14001-based environmental management system (EMS) in the Malaysian oil and gas sector were studied using the analytical hierarchy process (AHP) approach. An empirical study was performed to investigate the relative weights and priorities of these criteria and benefits. An AHP decision model of EMS adoption was …

Formation Of Copper Dots In Copper Decoration Technique, Swee Yong Pung

Student Works (2000-2009)

Copper ions are dissolved from highly pure copper plate into the methanol during copper decoration process. As a result, copper concentration in methanol is increased with time. The copper concentration in methanol measured by ICP-OES is correlated well with the calculated value based on the magnitude of current and time during the process. Consequently, higher magnitude of current can be applied to build up copper concentration in methanol in shorter period. When copper ions are ejected in methanol, they are positively charged. They experience force from electric field and migrate towards oxide surface. Eventually, these copper ions will be discharged …

Node Splitting Algorithms In Tree-Structured High-Dimensional Indexes For Similarity Search, Yongjian Fu, Jui Che Teng, S. R. Subramanya

Computer Science Faculty Research & Creative Works

Content-based searches and retrievals in multimedia and image databases use high-dimensional indexing structures for organizing the features of the objects. Most of those index structures are tree-structured whose nodes have a limit on the number of entries describing the subtrees rooted at those nodes. When index trees are built by repeated insertion of entries, nodes need to be split and the tree balanced accordingly. Node-splitting algorithms eventually determine the final structure of the tree which will have a profound effect on the search performance. This paper presents a comparative study of several node splitting algorithms for a typical high-dimensional indexing …

A Power Scheduling Software Package For Planetary Habitats, Gary W. Huband

College of Graduate Studies: Theses & Dissertations (1964–2006)

Mankind has established a permanent presence in space with the International Space Station. The next step is building habitats on the Moon or Mars. However, these habitats will have to be nearly self-sustaining because replenishment from Earth will be costly. Power for life support and other electrical devices will be limited and must be monitored and allocated. This thesis develops the framework for power scheduling software to perform these tasks.

The software includes a graphical user interface (GUI) to allow the user to interact with the power schedule, a database and server, and a simulation for the effects of device …

Advances In Space Radiation Shielding Codes, John W. Wilson, Ram K. Tripathi, Garry D. Qualls, Francis A. Cucinotta, Richard E. Prael, John W. Norbury, John H. Heinbockel, John Tweed, Giovanni De Angelis

Mathematics & Statistics Faculty Publications

Early space radiation shield code development relied on Monte Carlo methods and made important contributions to the space program. Monte Carlo methods have resorted to restricted one-dimensional problems leading to imperfect representation of appropriate boundary conditions. Even so, intensive computational requirements resulted and shield evaluation was made near the end of the design process. Resolving shielding issues usually had a negative impact on the design. Improved spacecraft shield design requires early entry of radiation constraints into the design process to maximize performance and minimize costs. As a result, we have been investigating high-speed computational procedures to allow shield analysis from …

Effect Of Cr3+ And So42- On The Structure Of Rust Layer Formed On Steels By Atmospheric Corrosion, Masato Yamashita, Hitoshi Uchida,, Desmond C. Cook .

Physics Faculty Publications

The effect of chromium ion (Cr³⁺) and sulfate ion (SO₄^2-) on the structure of the rust layer formed by thin electrolyte-film corrosion of low-alloy steels has been examined. By using X-ray diffraction spectroscopy, it was found that coexistence of Cr³⁺ and SO₄^2- in the electrolyte film covering the steel surface quickly forms the Cr-goethite (α-(Fe _1-X, Cr_X)OOH) layer which has been known as the final protective rust layer. Scanning vibrating electrode measurements showed that the rust layer formed under the electrolyte film containing Cr³⁺ and SO₄^{2- …}

A Scalable Architecture For Harvest-Based Digital Libraries, Xiaoming Liu, Tim Brody, Stevan Harnard, Les Carr, Kurt Maly, Mohammad Zubair, Michael L. Nelson

Computer Science Faculty Publications

This article discusses the requirements of current and emerging applications based on the Open Archives Initiative (OAI) and emphasizes the need for a common infrastructure to support them. Inspired by HTTP proxy, cache, gateway and web service concepts, a design for a scalable and reliable infrastructure that aims at satisfying these requirements is presented. Moreover, it is shown how various applications can exploit the services included in the proposed infrastructure. The article concludes by discussing the current status of several prototype implementations.

Nebraska Summary 382: Agco Rt115 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1804: John Deere 9320t 18 Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.

Test 1810: John Deere 9120 18 Speed, Nebraska Tractor Test Lab

Nebraska Tractor Tests

No abstract provided.