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2006

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Articles 3211 - 3240 of 3391

Full-Text Articles in Engineering

Combined Radiation Detection Methods For Assay Of Higher Actinides In Separation Processes (Afci), Denis Beller, Warnick Kernan Jan 2006

Combined Radiation Detection Methods For Assay Of Higher Actinides In Separation Processes (Afci), Denis Beller, Warnick Kernan

Safeguards Campaign (TRP)

The ultimate objective of this project is to develop technology to detect and accurately measure quantities of higher actinides in processing systems without taking frequent samples. These systems include used fuel receipt, separations batches, and pipelines. A variety of measurements may be combined to calculate flow rates of actinide elements with a to-be-determined precision. Nuclear and decay characteristics of materials during processing will be acquired, conceptual designs of monitoring systems will be developed, radiation transport studies will be conducted to develop an understanding of operational regimes, and experiments will be performed to confirm performance. Radiation transport and scoping studies will …


Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic, Yingtao Jiang, Bingmei Fu Jan 2006

Developing A Sensing System For The Measurement Of Oxygen Concentration In Liquid Pb-Bi Eutectic, Yingtao Jiang, Bingmei Fu

Transmutation Sciences Materials (TRP)

The research objectives of this project were as follows:

  • To generate calibration curves of voltage versus oxygen concentration for the YSZ oxygen sensor system under various temperatures in liquid LBE.
  • To determine the sensor characteristics of the YSZ sensor system.
  • To determine oxygen dissolving rates in LBE under different temperatures in vitro.
  • To study the effects of unwanted electrical conductivity, contributed by the mobility of the electrons at high temperatures, for more accurate oxygen measurement.
  • To study alternative and promising oxygen measuring methods.


Corrosion Mechanisms And Kinetics Of Steels In Lead-Bismuth Eutectic: Quaterly Report, Allen L. Johnson, John Farley Jan 2006

Corrosion Mechanisms And Kinetics Of Steels In Lead-Bismuth Eutectic: Quaterly Report, Allen L. Johnson, John Farley

Transmutation Sciences Materials (TRP)

A large number of studies of corroded samples were conducted using SEM, XPS, probe, and the TEM. Samples from the DELTA loop at LANL and from other sources were examined. Also, the investigation of 316 class stainless steel in LBE is continuing.

Corroded samples of D-9 steel have been in the process of being studies, which is a variant of 316 stainless steel that is optimized for resistance to swelling. The D-9 samples are notable for the process in which a localized failure of the protective oxide layer becomes widespread corrosion. The research group is examining the D-9 samples using …


Effect Of Silicon Content On The Corrosion Resistance And Radiation- Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems, Ajit K. Roy Jan 2006

Effect Of Silicon Content On The Corrosion Resistance And Radiation- Induced Embrittlement Of Materials For Advanced Heavy Liquid Metal Nuclear Systems, Ajit K. Roy

Transmutation Sciences Materials (TRP)

This task is primarily focused on the evaluation of the effect of Si content on the susceptibility of modified 9Cr-1Mo-0.24V steel to stress corrosion cracking (SCC) and localized cracking in both molten lead-bismuth eutectic (LBE) and an aqueous solution of acidic pH.

Further, significant efforts are in progress to characterize the deformation mechanism of modified T91 grade steel as a function of temperature and strain rate. Simultaneously, surface analyses of the tested materials are ongoing using state-of-the-art techniques including scanning electron microscopy (SEM) and transmission electron microscopy (TEM).


Corrosion Barrier Development For Lbe Corrosion Resistance: Quarterly Report (April 2006), Biswajit Das Jan 2006

Corrosion Barrier Development For Lbe Corrosion Resistance: Quarterly Report (April 2006), Biswajit Das

Transmutation Sciences Materials (TRP)

As reported in the last quarterly report, synthesis of Cr nanowires was found to be problematic in terms of uniform coverage. Hence Ni was identified as the alternative metal to form the nanowires. The purpose of the metal nanowires is to provide structural integrity to the nanoporous alumina, as well as a second defense mechanism against corrosion by oxidizing in case the top alumina layer is compromised. Nickel was selected due to its established electrochemical synthesis procedure. While Ni can provide very good structural integrity to the porous alumina, one potential problem is its higher dissolution rate in LBE. However, …


Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das Jan 2006

Development Of Nanostructure Based Corrosion-Barrier Coatings On Steel For Transmutation Applications, Biswajit Das

Transmutation Sciences Materials (TRP)

Advanced transmutation systems require structural materials that are able to withstand high neutron fluxes, high thermal cycling, and high resistance to chemical corrosion. The current candidate materials for such structures are ferritic and ferritic-martensitic steels due to their strong resistance to swelling, good microstructural stability under irradiation, and the retention of adequate ductility at typical reactor operating temperatures.

In parallel, lead bismuth eutectic (LBE) has emerged as a potential spallation target material for efficient production of neutrons, as well as a coolant in the accelerator system. While LBE has excellent properties as a nuclear coolant, it is also highly corrosive …


Neutron Multiplicity Measurements Of Target/Blanket Materials, Denis Beller Jan 2006

Neutron Multiplicity Measurements Of Target/Blanket Materials, Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is accelerator-driven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause nuclear reactions in subcritical systems.

To design these systems, complex reactor physics computer codes and highly detailed data libraries are used to compute the reactivity of systems, reaction rates, destruction rates, …


Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments (Race) Project, Denis Beller Jan 2006

Reactor Physics Studies For The Afci Reactor-Accelerator Coupling Experiments (Race) Project, Denis Beller

Transmutation Sciences Physics (TRP)

The specific research objective of this three-year project is to design and conduct an accelerator driven experiment. This experiment will help demonstrate in the U.S. the ability to design, compute, and conduct ADSS experiments; and to predict and measure source importance, coupling efficiency, sub-critical reactor kinetics and source-driven transients. In addition, databases will be created for both steady state and transient ADSS experiments for the nuclear community to develop and test new computational codes and methods, and the importance of a driving neutron source in various regions of different subcritical assemblies will be mapped. Experiments will be conducted and compared …


Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh Jan 2006

Development Of Integrated Process Simulation System Model For Spent Fuel Treatment Facility (Sftf) Design, Yitung Chen, Sean Hsieh

Separations Campaign (TRP)

The overall goal of this project is the creation of a framework that combines all the strengths of AMUSE’s complicated calculations, well-established commercial system process packages, and TRPSEMPro’s flexible parameter optimization modules. Development of the process simulation code can be done using the solvent extraction process at Argonne National Laboratory in collaboration with the UNLV Nevada Center for Advanced Computational Methods.

The major objectives are the following:

  • Develop a framework for simulating the Spent Fuel Treatment Facility (SFTF) process using AMUSE code, commercial process package, such as ASPEN-PLUS, and system engineering model.
  • Develop a middleware package that can communicate between …


Second Generation Waste Package Design Study, Sam Armijo, Mano Misra Jan 2006

Second Generation Waste Package Design Study, Sam Armijo, Mano Misra

Publications (YM)

The design of waste packages currently proposed for YMP is highly conservative. The candidate materials of construction of the waste packages and drip shields while highly corrosion resistant are extremely expensive and components made from these materials will require complex and expensive fabrication methods to assure their integrity. A proposed, second generation operating concept and waste package design, is intended to permit more efficient and less costly operation of the repository while maintaining waste package integrity. Major reductions in waste package costs can be realized by increasing the number of fuel assemblies stored in each waste package, eliminating the reference …


Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 1st Quarterly Report, 2006, Clemens Heske Jan 2006

Interaction Between Metal Fission Products And Triso Coating Materials: A Study Of Chemical Bonding And Interdiffusion: 1st Quarterly Report, 2006, Clemens Heske

Fuels Campaign (TRP)

This project is devoted to an in-depth study of the chemical and electronic impact of metal fission products on the coating layers in TRISO nuclear fuel. In particular, there is a focus on the investigation of Pd, Cs, and Ag and their interface formation with SiC and carbon-based substrates. A variety of surface and near-surface bulk sensitive probes that investigate the occupied and unoccupied electronic states of the substrate and the metal overlayer have been utilized. By a controlled and stepwise deposition of the metal overlayer, it is possible to gain substantial insight into the formation of interfaces and their …


Interaction Between Metal Fission Products And Triso Coating Materials, Clemens Heske Jan 2006

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

Fuels Campaign (TRP)

In this project the chemical bonding and interface formation of metal fission products with the coating materials used in TRISO fuel particles is investigated. The interface formation of Pd, Cs, and Ag with SiC and pyrolytic carbon is studied in detail. Using the SiC single crystals and TRISO coating materials as substrates, interfaces are prepared under controlled conditions in an ultra-high vacuum environment and are studied with a photoelectron spectroscopy, Auger electron spectroscopy, Inverse Photoemission, X-ray emission spectroscopy, and X-ray absorption spectroscopy. Recent additions to the experimental approach include microscopic techniques (Transmission Electron Microscopy, Scanning Tunneling Microscopy, Atomic Force Microscopy) …


Design Concepts And Process Analysis For Transmuter Fuel Manufacturing, Georg F. Mauer Jan 2006

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 Jan 2006

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

Fuels Campaign (TRP)

This project examines inert fuels containing ZrO2 and MgO as the inert matrix, with the relative amount of MgO varied from 30% to 70% in ZrO2. Reactor physics calculations are used to examine suitable quantities of burnable poisons from the candidate elements Gd, Er, or Hf with reactor grade Pu providing the fissile component, with up to 10% of 239Pu. Ceramics are synthesized and characterized based on the reactor physics results. The solubility of the fuel ceramics, in reactor conditions, reprocessing conditions, and repository conditions, are investigated in a manner to provide thermodynamic data necessary for …


Impact Of The Synthesis Process On Structure Properties For Afci Fuel Candidates, Thomas Hartmann Jan 2006

Impact Of The Synthesis Process On Structure Properties For Afci Fuel Candidates, Thomas Hartmann

Fuels Campaign (TRP)

Advanced Fuel Cycle Initiative research on transmutation fuels includes mono-nitride ceramic fuel forms, and consists of closely coordinated “hot” actinide and “cold” inert and surrogate fuels work. Matrix and surrogate materials work involves three major components: (1) fuel matrix synthesis and fabrication, (2) fuel performance, and (3) fuel materials modeling. The synthesis and fabrication component supports basic material studies, as well as actinide fuel fabrication work through fuel fabrication process development. Fuel performance studies are examining the tolerance of nitride-type fuel to heavy irradiation damage. The fuel materials simulation work involves both atomistic and continuum scale modeling employing first principles, …


Solution-Based Synthesis Of Nitride Fuels, Kenneth Czerwinski, Thomas Hartmann Jan 2006

Solution-Based Synthesis Of Nitride Fuels, Kenneth Czerwinski, Thomas Hartmann

Fuels Campaign (TRP)

A wide variety of fuel concepts are considered for advanced reactor technology including metals, metal oxides or metal nitrides as solid solutions or composite materials. Nitride fuels have appropriate properties for advanced fuels including high thermal conductivity, thermal stability, solid-state solubility of actinides, fissile metal density, and suitable neutronic properties. A drawback of nitride fuels involves their synthesis. A key parameter for preparing oxide fuels is the precipitation step in the sol-gel process. For nitride fuels, the current synthetic route is carbothermic reduction from the oxide to the nitride. This process step is based on solid phase reactions and for …


Database Anonymization Services, Chad B. Meador Jan 2006

Database Anonymization Services, Chad B. Meador

Graduate Theses, Dissertations, and Problem Reports (ETD)

The progress of technology and the development of powerful databases have made it possible to store and easily access continually increasing amounts of sensitive data about people. Since personal information is becoming common in many different databases, it is vital that this data be hidden to ensure privacy of the individuals whose records are stored in these repositories. Database anonymization is the key to securing these databases by ensuring that database users will be unable to reveal sensitive personal information by intelligently structuring their queries.

We analyzed the structure of the BiomData database which contains images and sound recordings of …


Effect Of Time-Based Parameters On The Agility Of A Dynamic Mpc System, A. M. Deif, W. H. Elmaraghy Jan 2006

Effect Of Time-Based Parameters On The Agility Of A Dynamic Mpc System, A. M. Deif, W. H. Elmaraghy

Industrial Technology and Packaging

This paper presents a dynamic manufacturing planning and control (MPC) system that can maintain agility through the ability to dynamically switch between different policies due to varying market strategies. The dynamic behavior of the developed system is investigated by studying the effect of the time based parameters on responsiveness and cost effectiveness of the system reflected in the natural frequency and the damping of its different configurations. Results showed that the agility requirements are directly affected by the time based parameters of the MPC system: production lead time, capacity scalability delay, and shipment time. This resulted in a better understanding …


A Control Approach To Explore The Dynamics Of Capacity Scalability In Reconfigurable Manufacturing Systems, Ahmed M. Deif, Waguih H. Elmaraghy Jan 2006

A Control Approach To Explore The Dynamics Of Capacity Scalability In Reconfigurable Manufacturing Systems, Ahmed M. Deif, Waguih H. Elmaraghy

Industrial Technology and Packaging

This paper presents a dynamic model and analysis for one of the major characteristics of reconfigurable manufacturing systems (RMSs) capacity scalability. The dynamic model is analyzed using its transfer function. Dynamic characteristics associated with the delay in capacity scalability and how to minimize this delay are discussed using control approaches. The problem of how to supply exact capacity in response to market changes is also examined by solving the dynamic problem of the production offset phenomenon in RMSs. The effect of work in process as a damping factor for production disturbances during capacity scalability is addressed. Finally, a general capacity …


A Comparison Of Time-Domain Time-Scale Modification Algorithms, David Dorran, Robert Lawlor, Eugene Coyle Jan 2006

A Comparison Of Time-Domain Time-Scale Modification Algorithms, David Dorran, Robert Lawlor, Eugene Coyle

Conference papers

Time-domain appraoches to time-scale modification are popular due to their ability to produce high quality results at a relatively low computational cost. Within the category of time-domain implementations quite a number of alternatives exist, each with their own computational requirements and associated output quality. This paper provides a computational and objective output quality assessment of a number of popular time-domain time-scaling implmentations; thus providing a means for developers to identify a suitable algorithm for their application of interest. In addition, the issues that should be considered in developing time-domain algorithms are outlines, purely in the context of a waveform editing …


Design And Optimization Of Nano-Optical Elements By Coupling Fabrication To Optical Behavior, Raymond Rumpf Jan 2006

Design And Optimization Of Nano-Optical Elements By Coupling Fabrication To Optical Behavior, Raymond Rumpf

Electronic Theses and Dissertations

Photonic crystals and nanophotonics have received a great deal of attention over the last decade, largely due to improved numerical modeling and advances in fabrication technologies. To this day, fabrication and optical behavior remain decoupled during the design phase and numerous assumptions are made about "perfect" geometry. As research moves from theory to real devices, predicting device behavior based on realistic geometry becomes critical. In this dissertation, a set of numerical tools was developed to model micro and nano fabrication processes. They were combined with equally capable tools to model optical performance of the simulated structures. Using these tools, it …


Predicting Surface Scatter Using A Linear Systems Formulation Of Non-Paraxial Scalar Diffraction, Andrey Krywonos Jan 2006

Predicting Surface Scatter Using A Linear Systems Formulation Of Non-Paraxial Scalar Diffraction, Andrey Krywonos

Electronic Theses and Dissertations

Scattering effects from rough surfaces are non-paraxial diffraction phenomena resulting from random phase variations in the reflected wavefront. The ability to predict these effects is important in a variety of applications including x-ray and EUV imaging, the design of stray light rejection systems, and reflection modeling for rendering realistic scenes and animations of physical objects in computer graphics. Rayleigh-Rice (small perturbation method) and Beckmann-Kirchoff (Kirchhoff approximation) theories are commonly used to predict surface scatter effects. In addition, Harvey and Shack developed a linear systems formulation of surface scatter phenomena in which the scattering behavior is characterized by a surface transfer …


Probing Random Media With Singular Waves, Chaim Schwartz Jan 2006

Probing Random Media With Singular Waves, Chaim Schwartz

Electronic Theses and Dissertations

In recent years a resurgence of interest in wave singularities (of which optical vortices are a prominent example), light angular momentum and the relations between them has occurred. Many applications in various areas of linear and non-linear optics have been based on studying effects related to angular momentum and optical vortices. This dissertation examines the use of such wave singularities for studying the light propagation in highly inhomogeneous media and the relationship to angular momentum transfer. Angular momentum carried by light can be, in many cases, divided in two terms. The first one relates to the polarization of light and …


Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng Jan 2006

Efficient Scheduling For Sdmg Cioq Switches, Mei Yang, S. Q. Zheng

Electrical & Computer Engineering Faculty Research

Combined input and output queuing (CIOQ) switches are being considered as high-performance switch architectures due to their ability to achieve 100% throughput and perfectly emulate output queuing (OQ) switch performance with a small speedup factor S. To realize a speedup factor S, a conventional CIOQ switch requires the switching fabric and memories to operate S times faster than the line rate. In this paper, we propose to use a CIOQ switch with space-division multiplexing expansion and grouped input/output ports (SDMG CIOQ switch for short) to realize speedup while only requiring the switching fabric and memories to operate at the line …


Development And Modeling Of Thermally Conductive Resins For Fuel Cell Bipolar Plate Applications, Michael G. Miller Jan 2006

Development And Modeling Of Thermally Conductive Resins For Fuel Cell Bipolar Plate Applications, Michael G. Miller

Dissertations, Master's Theses and Master's Reports - Open

Thermally conductive resins are a class of material that show promise in many different applications. One growing field for their use is in the area of bipolar plate technology for fuel cell applications. In this work, a LCP was mixed with different types of carbon fillers to determine the effects of the individual carbon fillers on the thermal conductivity of the composite resin. In addition, mathematical modeling was performed on the thermal conductivity data with the goal of developing predictive models for the thermal conductivity of highly filled composite resins.


Reducing Main Memory Access Latency Through Sdram Address Mapping Techniques And Access Reordering Mechanisms, Jun Shao Jan 2006

Reducing Main Memory Access Latency Through Sdram Address Mapping Techniques And Access Reordering Mechanisms, Jun Shao

Dissertations, Master's Theses and Master's Reports - Open

As the performance gap between microprocessors and memory continues to increase, main memory accesses result in long latencies which become a factor limiting system performance. Previous studies show that main memory access streams contain significant localities and SDRAM devices provide parallelism through multiple banks and channels. These locality and parallelism have not been exploited thoroughly by conventional memory controllers. In this thesis, SDRAM address mapping techniques and memory access reordering mechanisms are studied and applied to memory controller design with the goal of reducing observed main memory access latency.

The proposed bit-reversal address mapping attempts to distribute main memory accesses …


Porous Silicon Technology For Integrated Microsystems, Jin Zheng Wallner Jan 2006

Porous Silicon Technology For Integrated Microsystems, Jin Zheng Wallner

Dissertations, Master's Theses and Master's Reports - Open

With the development of micro systems, there is an increasing demand for integrable porous materials. In addition to those conventional applications, such as filtration, wicking, and insulating, many new micro devices, including micro reactors, sensors, actuators, and optical components, can benefit from porous materials. Conventional porous materials, such as ceramics and polymers, however, cannot meet the challenges posed by micro systems, due to their incompatibility with standard micro-fabrication processes. In an effort to produce porous materials that can be used in micro systems, porous silicon (PS) generated by anodization of single crystalline silicon has been investigated.

In this work, the …


Flow Simulation For Optimized Performance Of Displacement Pumps Manufactured By Engineered Machined Products, Jordan D. Bilyeu Jan 2006

Flow Simulation For Optimized Performance Of Displacement Pumps Manufactured By Engineered Machined Products, Jordan D. Bilyeu

Dissertations, Master's Theses and Master's Reports - Open

No abstract provided.


Fluidic Oscillator Design For Water Removal Enhancement In A Pem Fuel Cell, Sheng Han Tseng Jan 2006

Fluidic Oscillator Design For Water Removal Enhancement In A Pem Fuel Cell, Sheng Han Tseng

Dissertations, Master's Theses and Master's Reports - Open

This research initiative was triggered by the problems of water management of Polymer Electrolyte Membrane Fuel Cell (PEMFC). In low temperature fuel cells such as PEMFC, some of the water produced after the chemical reaction remains in its liquid state. Excess water produced by the fuel cell must be removed from the system to avoid flooding of the gas diffusion layers (GDL). The GDL is responsible for the transport of reactant gas to the active sites and remove the water produced from the sites. If the GDL is flooded, the supply gas will not be able to reach the reactive …


Treating Soil Pentachlorophenol (Pcp) At Optimal Conditions Using Heme And Peroxide, Shyi Tien Chen, David King Stevens, Guyoung Kang, M. J. Hsieh Jan 2006

Treating Soil Pentachlorophenol (Pcp) At Optimal Conditions Using Heme And Peroxide, Shyi Tien Chen, David King Stevens, Guyoung Kang, M. J. Hsieh

Civil and Environmental Engineering Faculty Publications

The environmental impact of pentachlorophenol (PCP) has been the subject of extensive research in recent years. Investigations of PCP degradation using both biotic and abiotic methods are extensively reported in literature. Based on some preliminary tests (not shown), an abiotic method was found for oxidative PCP degradation in soil under unsaturated conditions and a neutral pH. Reagents used were heme (a catalyst) and peroxide (an oxidant). From two screening tests (not shown), the heme and peroxide were identified as the most important factors on PCP degradation in highly PCP-contaminated soil. The objective of this study was to determine the optimum …