Engineering Commons^™

Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske

Fuels Campaign (TRP)

This project focuses on the chemical bonding and interface formation of metal fission products with the coating materials used in tri-isotropic (TRISO) fuel particles for gas-cooled reactors. By combining surface- and bulk-sensitive spectroscopic and microscopic methods, intermediate chemical phases at the interface, intermixing/diffusion behavior, and the electronic interface structure for different coating materials and metals are examined.

In detail, the project studies the interface formation of Pd, Cs, and Ag with SiC and pyrolytic carbon. Using SiC single crystals and highly-ordered pyrolytic carbon (HOPG) as substrates, interfaces are prepared under controlled conditions in an ultra-high vacuum environment and are studied …

Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer

Fuels Campaign (TRP)

The safe and effective manufacturing of actinide-bearing fuels for any transmutation strategy requires that the entire manufacturing process be contained within a shielded hot cell environment. To ensure that the fabrication process is feasible, the entire process must be designed for remote operation. The equipment must be reliable enough to perform over several decades, and also easy to maintain or repair remotely. The facility must also be designed to facilitate its own decontamination and decommissioning. In addition to these design factors, the potential viability of any fuel fabrication process will also be impacted by a number of variables, such as …

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix, Kenneth Czerwinski

Fuels Campaign (TRP)

This project will examine inert fuels containing ZrO₂ and MgO as the inert matrix. Ceramics with this inert matrix, Ce, U and eventually Pu will be synthesized and examined. While the Advanced Fuel Cycle Initiative focus is on inert fuels with Pu as the fissile component, this task will perform initial laboratory experiments with Ce and U. The initial work with Ce will be performed early in the project with results used as a basis for U studies. Reactor physics calculations will be used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf. …

Impact Of The Synthesis Process On Structure Properties For Afci Fuel Candidates, Kenneth Czerwinski

Fuels Campaign (TRP)

The research objectives are:

• To explore a low-temperature fluoride route to synthesize actinide nitrides. • To characterize actinide nitrides structurally and thermally.

• To use high resolution TEM techniques to explore the microstructure of the radioactive samples.

Solution-Based Synthesis Of Nitride Fuels, Kenneth Czerwinski, Tyler A. Sullens

Fuels Campaign (TRP)

One of the original synthetic routes devised for the synthesis of U (III)N involved the entire reaction taking place in liquid ammonia. Several experimental reactions were conducted in an attempt to synthesize the UI₃(NH₃)_x and U(NH₂)₃(NH₃)_x precursors of U(III) N. Each attempt involved cleaning of the uranium metal to remove the oxide coating of the metal reagent with 3 washes of concentrated nitric acid, each followed by a rinse with liquid ammonia. Success of this cleaning procedure was varied, with a majority of cleaned metal oxidizing rapidly once …

Improved High-Temperature Stability And Sun-Light-Driven Photocatalytic Activity Of Sulfur-Doped Anatase Tio2, Suresh Pillai, Declan Mccormack, Pradeepan Periyat, John Colreavy, Steve Hinder

Articles

No abstract provided.

Low Noise, High Repetition Rate Semiconductor-Based Mode-Locked Lasers For Signal Processing And Coherent Communications, Franklyn Quinlan

Electronic Theses and Dissertations

This dissertation details work on high repetition rate semiconductor mode-locked lasers. The qualities of stable pulse trains and stable optical frequency content are the focus of the work performed. First, applications of such lasers are reviewed with particular attention to applications only realizable with laser performance such as presented in this dissertation. Sources of timing jitter are also reviewed, as are techniques by which the timing jitter of a 10 GHz optical pulse train may be measured. Experimental results begin with an exploration of the consequences on the timing and amplitude jitter of the phase noise of an RF source …

Ultrashort Laser Pulse Interaction With Photo-Thermo-Refractive Glass, Leo Siiman

Electronic Theses and Dissertations

Photo-thermo-refractive (PTR) glass is an ideal photosensitive material for recording phase volume holograms. It is a homogeneous multi-component silicate glass that demonstrates all the advantages of optical glass: thermal stability, high laser damage threshold, and a wide transparency range. Moreover the ability to record phase patterns (i.e. spatial refractive index variations) into PTR glass has resulted in the fabrication of volume holograms with diffraction efficiency greater than 99%. The conventional method of recording a hologram in PTR glass relies on exposure to continuous-wave ultraviolet laser radiation. In this dissertation the interaction between infrared ultrashort laser pulses and PTR glass is …

Cholesteric Liquid Crystal Photonic Crystal Lasers And Photonic Devices, Ying Zhou

Electronic Theses and Dissertations

This dissertation discusses cholesteric liquid crystals (CLCs) and polymers based photonic devices including one-dimensional (1D) photonic crystal lasers and broadband circular polarizers. CLCs showing unique self-organized chiral structures have been widely used in bistable displays, flexible displays, and reflectors. However, the photonic band gap they exhibit opens a new way for generating laser light at the photonic band edge (PBE) or inside the band gap. When doped with an emissive laser dye, cholesteric liquid crystals provide distributed feedback so that mirrorless lasing is hence possible. Due to the limited surface anchoring, the thickness of gain medium and feedback length is …

Integrated Optical Spr (Surface Plasmon Resonance) Sensor Based On Optoelectronic Platform, Hyungseok Bang

Electronic Theses and Dissertations

Current major demands in SPR sensor development are system miniaturization and throughput improvement. Structuring an array of integrated optical SPR sensor heads on a semiconductor based optoelectronic platform could be a promising solution for those issues, since integrated optical waveguides have highly miniaturized dimension and the optoelectronic platform enables on-chip optical-to-electrical signal conversion. Utilizing a semiconductor based platform to achieve optoelectronic functionality poses requirements to the senor head; the sensor head needs to have reasonably small size while it should have reasonable sensitivity and fabrication tolerance. This research proposes a novel type of SPR sensor head and demonstrates a fabricated …

Extended Focus Range High Resolution Endoscopic Optical Coherence Tomography, Kye-Sung Lee

Electronic Theses and Dissertations

Today, medical imaging is playing an important role in medicine as it provides the techniques and processes used to create images of the human body or parts thereof for clinical purposes (medical procedures seeking to reveal, diagnose or examine disease) or medical science (including the study of normal anatomy and function). Modalities are developing over time to achieve the highest possible resolution, speed of image acquisition, sensitivity, and specificity. In the past decade, advances in optics, fiber, as well as laser technology have enabled the development of noninvasive optical biomedical imaging technology that can also be applied to endoscopy to …

Biomedical Circuits And Systems Dedicated For Sensing And Neurostimulation: Case Study On Urinary Bladder Dysfunctions, Mohamad Sawan, Aguibou Ba, Faycal Mounaim, Jacques Corcos, Mostafa Elhilali

Turkish Journal of Electrical Engineering and Computer Sciences

This paper covers circuits and systems techniques for the construction of high reliability biosensing and neurostimulation smart medical devices. Such microsystems are dedicated for interconnections through the peripheral neural systems. Case study related to applications such as bladder control is discussed. Available electrical neurostimulation techniques for the rehabilitation of urinary bladder functions do not allow an adequate voiding due to dyssynergia between the bladder and the sphincter. A new implantable stimulator, built with commercially available electronic components, was designed to overcome these difficulties. The proposed system performs two types of stimulations: Selective Stimulation for bladder voiding and Permanent Stimulation to …

Pattern Synthesis With Uniform Circular Arrays For The Reduction Of Wcdma Intercell Interference, Mohammed Al-Husseini, Elias Yaacoub, Karim Y. Kabalan, Ali El-Hajj

Turkish Journal of Electrical Engineering and Computer Sciences

The deployment of advanced antenna arrays at the base stations of cellular systems is a key technique in reducing intercell interference, and thus increasing the number of served users. Uniform circular arrays (UCAs) provide 360 degrees of coverage, their patterns are steering-invariant and their sidelobe levels are controllable. This paper investigates the use of UCAs having specially synthesized patterns at the base stations of WCDMA cellular systems. The decrease in the ratio of intercell interference to intracell power resulting from the use of these arrays in a beam-steering scheme will be assessed, and the advantages and disadvantages of each pattern …

Distance Relaying Algorithm For Double-Circuit Transmission Line With Compensation For Reactance Effect Under Standard Availability Of Measurements, Jan Izykowski, Marcin Bozek

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with non-pilot distance protection of a double-circuit transmission line. Negative impact of the reactance effect, appearing in measuring a fault loop impedance, on operation of the relay is discussed. An adaptive algorithm allowing one to prevent the relay from mis- or mal-operation caused by the reactance effect is introduced. The algorithm is designed for a standard availability of measurements from one end of the double-circuit line, i.e. when three-phase voltage and current from the faulted line circuit, and additionally zero-sequence current from the healthy line circuit, are provided as the relay input signals. The algorithm is based …

From Engineering Electromagnetics To Electromagnetic Engineering: Using Computational Electromagnetics For Synthesis Problems, Anton G. Tijhuis, Martijn C. Van Beurden, Bastiaan P. De Hon, Hubregt J. Visser

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a two-stage approach is proposed for using computational electromagnetics in antenna engineering. First, stochastic optimization techniques are used in combination with approximate models. Second, line-search techniques are combined with full-wave modeling. For the first stage, we show an illustrative example. The second stage is considered in detail; both the acceleration of the underlying field computations and the implementation of the optimization are discussed.

A Summary Of Recent Developments On Metamaterial-Based And Metamaterial-Inspired Efficient Electrically Small Antennas, Aycan Erentok, Richard W. Ziolkowski

Turkish Journal of Electrical Engineering and Computer Sciences

This paper summarizes our recent research efforts to realize efficient electrically small antenna (EESA) systems based on ideal analytical and numerical metamaterial-based antenna systems, and physically realized metamaterial-inspired antenna designs. Our theoretical and numerical studies of the radiation and resonance behaviors of the proposed metamaterial-based EESA systems, as well as our efforts to conceptualize structures which might be used to build them, have led to the discovery of several realizable metamaterial-inspired EESA systems. The measurement results confirm the numerical performance predictions.

A Study Of The Interaction Of Thioindigo Dye, With Several Inorganic Host Materials, Alejandra Ramirez

Open Access Theses & Dissertations

Maya Blue has been the focus of numerous studies and is believed to be a mixture of palygorskite clay and indigo dye.^1,2 Several derivatives of this pigment have been developed with intriguing properties. For instance, the dye thioindigo reacts with the palygorskite clay to exhibit a broad range of colors from red to blue under UV-Vis excitation. Based on FT-Raman and computer simulation, previous work performed in our group could relate indigo and thioindigo interaction to the aluminum sites in the framework. super>3,4

The work performed with other inorganic host materials such as, layer structures and zeolites have …

A Distributed Reconstruction Of Ekg Signals, Gabriel Cordova

Open Access Theses & Dissertations

In this Thesis the parallel computing methodology is applied to an algorithm used in the reconstruction of electrocardiographic (EKG) measurements. The reconstructions are being performed to obtain a better understanding of the source and behavior of the electrical activity that generates the EKG measurements. The contribution of this Thesis is to identify and eliminate inefficiencies present in the current reconstruction algorithm. Additionally, this Thesis reduces the computation times of the EKG reconstruction by applying distributed computing through the use of Remote Procedure Calls (RPC). Lastly, it provides an analysis of the speed-up and efficiency of the distribution implemented using parallel …

Byzantium Beneath The Black Sea, Bridget Buxton, Robert Ballard, Michael Brennan, Dwight Coleman, Katy Croff, Christopher Roman, Dan Davis, Dennis Piechota, Sergiy Voronov

Graduate School of Oceanography Faculty Publications

This poster reports on the August 2007 Black Sea Expedition of the Institute for Archaeological Oceanography at the University of Rhode Island (IAO) and the Institute for Exploration (IFE), in collaboration with the Department of the Underwater Heritage of Ukraine. This year’s work marks a new phase in a multi-year (2000–2012) archaeological and oceanographic survey of the Black Sea. 2007 fieldwork focuses on two Byzantine shipwrecks. The 10th century C.E. shipwreck Chersonesos A (discovered in 2006) lies at 140 m depth in the suboxic zone off the Crimean peninsula. The ship carried a cargo of one-handled jars of a widely …

Evaluation Of An Image Processing Algorithm For Scene Change Detection, Daniel Flores

Open Access Theses & Dissertations

Despite the efforts to reduce traffic accidents by government entities and automobile manufactures, the numbers of accidents are not considerably reduced. An evaluation of an algorithm based on the fly's eye is done on this research applying its principles to detect scene change on images for printed circuit boards providing initial steps to implement this algorithm on vehicular traffic to keep track of objects moving on the field for collision avoidance purposes. The effectiveness of the algorithm is addressed through a comparison of its performance with that found in experimental data.

Screening The Phytoremediation Potential Of Native Plants Growing On Mine Tailings In Arizona, Usa, Md Nazmul Haque

Open Access Theses & Dissertations

Mining companies have been playing an important role for the utilization of the Earth's natural resources for the prosperity of human society. However, the mining of resources has generated solid wastes called tailings that have become a serious environmental threat worldwide. Technologies such as soil caping have been used to remediate the problem. Nevertheless, the remediation of mine tailings using conventional technologies is costly and environmentally unpleasant. Since the last few decades, a plant based technology known as phytoremediation has appeared as a promising alternative. Several plant species have demonstrated to have phytoremediation capabilities; though, best results have been obtained …

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

Developing A Process Model For The Forensic Extraction Of Information From Desktop Search, Timothy Pavlic, Jill Slay, Benjamin Turnbull

Journal of Digital Forensics, Security and Law

Desktop search applications can contain cached copies of files that were deleted from the file system. Forensic investigators see this as a potential source of evidence, as documents deleted by suspects may still exist in the cache. Whilst there have been attempts at recovering data collected by desktop search applications, there is no methodology governing the process, nor discussion on the most appropriate means to do so. This article seeks to address this issue by developing a process model that can be applied when developing an information extraction application for desktop search applications, discussing preferred methods and the limitations of …

Table Of Contents

Journal of Digital Forensics, Security and Law

No abstract provided.

Book Review: Guide To Computer Forensics And Investigations (3rd Ed.), Keyu Jiang, Ruifeng Xuan

Journal of Digital Forensics, Security and Law

No abstract provided.

An Evaluation Of Windows-Based Computer Forensics Application Software Running On A Macintosh, Gregory H. Carlton

Journal of Digital Forensics, Security and Law

The two most common computer forensics applications perform exclusively on Microsoft Windows Operating Systems, yet contemporary computer forensics examinations frequently encounter one or more of the three most common operating system environments, namely Windows, OS-X, or some form of UNIX or Linux. Additionally, government and private computer forensics laboratories frequently encounter budget constraints that limit their access to computer hardware. Currently, Macintosh computer systems are marketed with the ability to accommodate these three common operating system environments, including Windows XP in native and virtual environments. We performed a series of experiments to measure the functionality and performance of the two …

Data Mining Techniques In Fraud Detection, Rekha Bhowmik

Journal of Digital Forensics, Security and Law

The paper presents application of data mining techniques to fraud analysis. We present some classification and prediction data mining techniques which we consider important to handle fraud detection. There exist a number of data mining algorithms and we present statistics-based algorithm, decision treebased algorithm and rule-based algorithm. We present Bayesian classification model to detect fraud in automobile insurance. Naïve Bayesian visualization is selected to analyze and interpret the classifier predictions. We illustrate how ROC curves can be deployed for model assessment in order to provide a more intuitive analysis of the models.

Book Review: Challenges To Digital Forensic Evidence, Gary C. Kessler

Journal of Digital Forensics, Security and Law

This issue presents the fifth Book Review column for the JDFSL. It is an experiment to broaden the services that the journal provides to readers, so we are anxious to get your reaction. Is the column useful and interesting? Should we include more than one review per issue? Should we also review products? Do you have suggested books/products for review and/or do you want to write a review? All of this type of feedback -- and more -- is appreciated. Please feel free to send comments to Gary Kessler ([email protected]) or Glenn S. Dardick ([email protected]).

Book Review: The Dotcrime Manifesto: How To Stop Internet Crime, Gary C. Kessler

Journal of Digital Forensics, Security and Law

No abstract provided.

The 2007 Analysis Of Information Remaining On Disks Offered For Sale On The Second Hand Market, Andy Jones, Craig Valli, Glenn S. Dardick, Iain Sutherland

Journal of Digital Forensics, Security and Law

All organisations, whether in the public or private sector, increasingly use computers and other devices that contain computer hard disks for the storage and processing of information relating to their business, their employees or their customers. Individual home users also increasingly use computers and other devices containing computer hard disks for the storage and processing of information relating to their private, personal affairs. It continues to be clear that the majority of organisations and individual home users still remain ignorant or misinformed of the volume and type of information that is stored on the hard disks that these devices contain …