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470 Matching Results
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CIRCE, the Coherent Infrared Center at the ALS
CIRCE (Coherent InfraRed CEnter) is a proposal for a new electron storage ring to be built at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL). The ring design is optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. Among others, CIRCE operation includes three interesting CSR modes: ultra stable, femtosecond laser slicing and broadband bursting. CSR allows CIRCE to generate an extremely high flux in the terahertz frequency region. The many orders of magnitude increase in the intensity over that presently achievable by conventional sources, has the potential to enable new science experiments. The characteristics of CIRCE and of the different modes of operation are described in this paper.
Date:
June 29, 2004
Creator:
Byrd, John M.; De Santis, Stefano; Jung, Jin-Young; Li, Derun; Martin, Michael C.; McKinney, W. et al.
Object Type:
Article
System:
The UNT Digital Library
Finite element analysis of unanchored structures subjected to seismic excitation
None
Date:
March 29, 2004
Creator:
Mastilovic, S.
Object Type:
Presentation
System:
The UNT Digital Library
Polyimide and BeO mini port card performance comparison for CDF Run IIb
The new silicon detector design for CDF relies on advanced packaging solutions in order to attain the strict small size and low mass requirements dictated by the experiment's physics program. The silicon strip detector at CDF is composed of overlaying silicon sensors in the form of a barrel around the colliding beam. The electronic instrumentation (sensors, readout and transceiver chips) is assembled into the staves of this barrel. In this paper we describe the development of the mini port card (MPC). The MPC is located at one of the ends of the stave, and it is responsible for signal translation and repetition from the readout chips to and from the data acquisition system (DAQ). The MPC's development has taken two approaches that use different technologies. One of the approaches uses BeO as the board substrate (BeO-MPC), while the other approach uses a hybrid rigid-flexible polyimide substrate (Poly-MPC). We present test results of pre-production parts, each one assembled with a different MPC packaging technology. Complete thermal and electrical characterization of the MPC is shown, and the advantages and disadvantages of both technologies, as well as their influence in the overall system performance, are presented.
Date:
March 29, 2004
Creator:
al., Guilherme Cardoso et
Object Type:
Article
System:
The UNT Digital Library
Oleds for General Lighting
The goal of this program was to reduce the long term technical risks that were keeping the lighting industry from embracing and developing organic light-emitting diode (OLED) technology for general illumination. The specific goal was to develop OLEDs for lighting to the point where it was possible to demonstrate a large area white light panel with brightness and light quality comparable to a fluorescence source and with an efficacy comparable to that of an incandescent source. it was recognized that achieving this would require significant advances in three area: (1) the improvement of white light quality for illumination, (2) the improvement of OLED energy efficiency at high brightness, and (3) the development of cost-effective large area fabrication techniques. The program was organized such that, each year, a ''deliverable'' device would be fabricated which demonstrated progress in one or more of the three critical research areas. In the first year (2001), effort concentrated on developing an OLED capable of generating high illumination-quality white light. Ultimately, a down-conversion method where a blue OLED was coupled with various down-conversion layers was chosen. Various color and scattering models were developed to aid in material development and device optimization. The first year utilized this approach …
Date:
February 29, 2004
Creator:
Duggal, Anil; Foust, Don; Heller, Chris; Nealon, Bill; Turner, Larry; Shiang, Joe et al.
Object Type:
Report
System:
The UNT Digital Library
The Status of Thermophotovoltaic Energy Conversion Technology at Lockheed Martin Corporation
In a thermophotovoltaic (TPV) energy conversion system, a heated surface radiates in the mid-infrared range onto photocells which are sensitive at these energies. Part of the absorbed energy is converted into electric output. Conversion efficiency is maximized by reducing the absorption of non-convertible energy with some form of spectral control. In a TPV system, many technology options exist. Our development efforts have concentrated on flat-plate geometries with greybody radiators, front surface tandem filters and a multi-chip module (MCM) approach that allows selective fabrication processes to match cell performance. Recently, we discontinued development of GaInAsSb quaternary cell semiconductor material in favor of ternary GaInAs material. In our last publication (Ref. 1), the authors reported conversion efficiencies of about 20% (radiator 950 C, cells 22 C) for small modules (1-4 cm{sup 2}) tested in a prototypic cavity test environment. Recently, we have achieved measured conversion efficiencies of about 12.5% in larger ({approx}100 cm{sup 2}) test arrays. The efficiency reduction in the larger arrays was probably due to quality and variation of the cells as well as non-uniform illumination from the hot radiator to the cold plate. Modules in these tests used GaInAsSb cells with 0.52 eV bandgap and front surface filters for …
Date:
July 29, 2004
Creator:
Brown, E. J.; Baldasaro, P. F.; Burger, S. R.; Danielson, L. R.; DePoy, D. M.; Dolatowski, J. M. et al.
Object Type:
Report
System:
The UNT Digital Library
Final Report of the Grant: ''Vertical Transport and Mixing in Complex Terrain Airsheds''
Stable stratification associated with nocturnal thermal circulation in areas of complex terrain leads to interesting and important phenomena that govern local meteorology and contaminant dispersion. Given that most urban areas are in complex topography, understanding and prediction of such phenomena are of immediate practical importance. This project dealt with theoretical, laboratory, numerical and field experimental studies aimed at understanding stratified flow and turbulence phenomena in urban areas, with particular emphasis on flow, turbulence and contaminant transport and diffusion in such flows. A myriad of new results were obtained and some of these results were used to improve the predictive capabilities of the models.
Date:
December 29, 2004
Creator:
Fernando, Harindra Joseph; Anderson, James; Boyer, Don & Berman, Neil
Object Type:
Report
System:
The UNT Digital Library
Hydroacoustic Studies Using HydroCAM - Station Centric Integration of Models and Observations Quarterly Report No. 5 October - December 2003
OAK-B135 Quarterly Technical Report summarizing BBN's support of the DOE/NNSA GNEM program. This report details BBN's efforts to improve the modeling of explosions and other events underwater and their propagation to hydroacoustic sensor networks. OK to release, no restriction on copyright
Date:
March 29, 2004
Creator:
Upton, Zachary M. & Pulli, Jay J.
Object Type:
Report
System:
The UNT Digital Library
An Advanced Fracture Characterization and Well Path Navigation System for Effective Re-Development and Enhancement of Ultimate Recovery From the Complex Monterey Reservoir of South Ellwood Field, Offshore California, Quarterly Report: January - March 2004
Venoco Inc, intends to re-develop the Monterey Formation, a Class III basin reservoir, at South Ellwood Field, Offshore Santa Barbara, California. Well productivity in this field varies significantly. Cumulative Monterey production for individual wells has ranged from 260 STB to 8,700,000 STB. Productivity is primarily affected by how well the well path connects with the local fracture system and the degree of aquifer support. Cumulative oil recovery to date is a small percentage of the original oil in place. To embark upon successful re-development and to optimize reservoir management, Venoco intends to investigate, map and characterize field fracture patterns and the reservoir conduit system. State of the art borehole imaging technologies including FMI, dipole sonic and cross-well seismic, interference tests and production logs will be employed to characterize fractures and micro faults. These data along with the existing database will be used for construction of a novel geologic model of the fracture network. Development of an innovative fracture network reservoir simulator is proposed to monitor and manage the aquifer's role in pressure maintenance and water production. The new fracture simulation model will be used for both planning optimal paths for new wells and improving ultimate recovery. In the second phase …
Date:
April 29, 2004
Creator:
Horner, Steve
Object Type:
Report
System:
The UNT Digital Library
LBNL report of the vetting review of the GRETINA project
GRETINA is a gamma-ray detector array capable of reconstructing the energy and spatial positions of gamma-ray interactions within the germanium crystals. It will be used to study the structure and stability of nuclei under various conditions. The new capabilities provided by gamma-ray tracking will give large gains in sensitivity for a large number of experiments, particularly those aimed at nuclei far from beta stability. A proposal for GRETINA was submitted to DOE in June 2003. It presented the scientific case, the readiness of technical development, the design, the suggested management organizations, and a proposed cost and schedule. The GRETINA proposal received its CD0 approval in August 2003. The CD-1 review will be held on December 3 and 4, 2003, and will be handled by the DOE-N. This report presents the charge to the GRETINA vetting review committee, and the findings, comments and recommendations of this committee. The purpose of this project vetting review was to assure that the GRETINA project is on track to provide DOE and the nuclear physics community with the agreed upon deliverables within the agreed upon budget and schedule. The vetting review committee was asked to cover both technical and management aspects of the GRETINA Project. …
Date:
March 29, 2004
Creator:
Robinson, K. E.; Bercovitz, J. H.; Bieser, F. S.; Jared, R. C.; Karpenko, V. P.; Klein, S. R. et al.
Object Type:
Report
System:
The UNT Digital Library
Use of Electrochemical Noise to Assess Corrosion in Kraft Continuous Digesters
Electrochemical noise (EN) probes were deployed in two continuous kraft digesters at a variety of locations representative of corrosion throughout the vessels. Current and potential noise, the temperature at each probe location, and the value of up to 60 process parameters (flow rates, liquor chemistry, etc.) were monitored continuously during each experiment. The results indicate that changes in furnish composition and process upsets were invariably associated with concurrent substantial changes in EN activity throughout the vessels. Post-test evaluation of the mild steel electrode materials in both vessels confirmed general corrosion of a magnitude consistent with historical trends in the respective vessels as well as values qualitatively (and semi-quantitatively) related to EN current sums for each electrode pair. Stainless steel electrodes representing 309LSi and 312 overlay repairs exhibited zero wastage corrosion--as did the actual overlays--but the EN data indicated periodic redox activity on the stainless steel that varied with time and position within the vessel. Little or no correlation between EN probe activity and other operational variables was observed in either vessel. Additional details for each digester experiment are summarized.
Date:
November 29, 2004
Creator:
Pawel, S.J.
Object Type:
Report
System:
The UNT Digital Library
Commissioning of BL 7.2, the new diagnostic beam line at the ALS
BL 7.2 is a new beamline at the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory (LBNL) dedicated to electron beam diagnostics. The system, which is basically a hard x-ray pinhole camera, was installed in the storage ring in August 2003 and commissioning with the ALS electron beam followed immediately after. In this paper the commissioning results are presented together with the description of the relevant measurements performed for the beamline characterization.
Date:
June 29, 2004
Creator:
Sannibale, Fernando; Baum, Dennis; Biocca, Alan; Kelez, Nicholas; Nishimura, Toshiro; Scarvie, Tom et al.
Object Type:
Article
System:
The UNT Digital Library
Closeout Technical Report
We are conducting a collaborative research program on two tokamaks, HT-7 and EAST (Experimental Advanced Superconducting Tokamak, formerly HT-7U), with the Institute of Plasma Physics of the Chinese Academy of Sciences (CASIPP) located in Hefei, PRC. The work that we planned for this year included conducting transport experiments on HT-7, completing plans for expansion of the HT-7 diagnostic set, and reaching an agreement on how UT-FRC can best participate in experiments on HT-7U. These goals were accomplished as summarized in the next section. Note that the experimental portion of the work is still underway. The experimental campaign for HT-7 began just a few weeks before this report was compiled.
Date:
November 29, 2004
Creator:
Gentle, Kenneth W., Dr.
Object Type:
Report
System:
The UNT Digital Library
MULTI-POLLUTANT CONTROL USING MEMBRANE--BASED UP-FLOW WET ELECTROSTATIC PRECIPITATION
This is the Final Report of the ''Multi-Pollutant Control Using Membrane-Based Up-flow Wet Electrostatic Precipitation'' project funded by the US Department of Energy's National Energy Technology Laboratory under DOE Award No. DE-FC26-02NT41592 to Croll-Reynolds Clean Air Technologies (CRCAT). In this 18 month project, CRCAT and its team members conducted detailed emission tests of metallic and new membrane collection material within a wet electrostatic precipitator (WESP) at First Energy's Penn Power's Bruce Mansfield (BMP) plant in Shippingport, Pa. The Membrane WESP was designed to be as similar as the metallic WESP in terms of collection area, air-flow, and electrical characteristics. Both units are two-field units. The membrane unit was installed during the 2nd and 3rd quarters of 2003. Testing of the metallic unit was performed to create a baseline since the Mansfield plant had installed selective catalytic reduction equipment for NOx control and a sodium bisulfate injection system for SO3 control during the spring of 2003. Tests results on the metallic WESP were consistent with previous testing for PM2.5, SO3 mist and mercury. Testing on the membrane WESP demonstrated no adverse impact and equivalent removal efficiencies as that of the metallic WESP. Testing on both units was performed at 8,000 acfm …
Date:
October 29, 2004
Creator:
Reynolds, James
Object Type:
Report
System:
The UNT Digital Library
Differential Soil Impedance Obstacle Detection Quarterly Report
This project develops a new and unique obstacle detection sensor for horizontal directional drilling (HDD) equipment. The development of this new technology will greatly improve the reliability and safety of natural gas HDD construction practices. This sensor utilizes a differential soil impedance measurement technique that will be sensitive to the presence of plastic and ceramic, as well as metallic obstacles. The use of HDD equipment has risen significantly in the gas industry because HDD provides a much more cost-effective and less disruptive method for gas pipe installation than older, trenching methods. However, there have been isolated strikes of underground utilities by HDD equipment, which may have been avoided if methods were available to detect other underground obstacles when using HDD systems. GTI advisors from the gas industry have ranked the value of solving the obstacle detection problem as the most important research and development project for GTI to pursue using Federal Energy Regulatory Commission (FERC) funds available through its industry partner, GRI. GTI proposes to develop a prototype down-hole sensor system that is simple and compact. The sensor utilizes an impedance measurement technique that is sensitive to the presence of metallic or non-metallic objects in the proximity of the HDD …
Date:
October 29, 2004
Creator:
Kieba, Maximillian J. & Ziolkowski, Christopher J.
Object Type:
Report
System:
The UNT Digital Library
Implementation of Methodology for Final Hazard Categorization of a DOE Nuclear Facility
U.S. Department of Energy (DOE) nuclear facilities are categorized by the level of hazard they pose to workers, the general public, and the environment. This paper applies the methodology outlined in DOE-STD-1027-92 and interpreted in recent DOE guidance to a nuclear material storage facility at the Savannah River Site to reduce the category of the facility to below HC-3.
Date:
March 29, 2004
Creator:
VINCENT, ANDREWN
Object Type:
Article
System:
The UNT Digital Library
Flavor violation in warped extra dimensions and CP Asymmetries in B decays
We show that CP asymmetries in b {yields} s hadronic decays are potentially affected by the presence of massive color-octet particles strongly coupled to the third generation quarks. Theories with warped extra dimensions provide natural candidates in the Kaluza-Klein excitations of gluons in scenarios where flavor-breaking by bulk fermion masses results in the localization of fermion wave-functions. Topcolor models, in which a new gauge interaction leads to top-condensation and a large top mass, also result in the presence of these color-octet states with TeV masses. We find that large effects are possible in modes such as B {yields} {phi}K{sub s}, B {yields} {eta}{prime}K{sub s} and B {yields} {pi}{sup 0}K{sub s} among others.
Date:
April 29, 2004
Creator:
Burdman, Gustavo
Object Type:
Article
System:
The UNT Digital Library
LUX - a recirculating linac-based facility for ultrafast X-ray science
We present recent developments in design concepts for LUX - a source of ultra-short synchrotron radiation pulses based on a recirculating superconducting linac. The source produces high-flux x-ray pulses with duration of 100 fs or less at a 10 kHz repetition rate, optimized for the study of ultra-fast dynamics across many fields of science [1]. Cascaded harmonic generation in free-electron lasers (FEL's) produces coherent radiation in the VUV-soft x-ray regime, and a specialized technique is used to compress spontaneous emission for ultra-short-pulse photon production in the 1-10 keV range. High-brightness electron bunches of 2-3 mm-mrad emittance at 1 nC charge in 30 ps duration are produced in an rf photocathode gun and compressed to 3 ps duration following an injector linac, and recirculated three times through a 1 GeV main linac. In each return path, independently tunable harmonic cascades are inserted to produce seeded FEL radiation in selected photon energy ranges from approximately 20 eV with a single stage of harmonic generation, to 1 keV with a four-stage cascade. The lattice is designed to minimize emittance growth from effects such as coherent synchrotron radiation (CSR), and resistive wall wakefields. Timing jitter between pump lasers and x-ray pulses is minimized by …
Date:
June 29, 2004
Creator:
Corlett, J. N.; Barletta, W. A.; DeSantis, S.; Doolittle, L.; Fawley, W. M.; Heimann, P. et al.
Object Type:
Article
System:
The UNT Digital Library
ADMP Mixing of Tank 18F: History, Modeling, Testing, and Results
Residual radioactive waste was removed from Tank 18F in the F-Area Tank Farm at Savannah River Site (SRS), using the advanced design mixer pump (ADMP). Known as a slurry pump, the ADMP is a 55 foot long pump with an upper motor mounted to a steel super structure, which spans the top of the waste tank. The motor is connected by a long vertical drive shaft to a centrifugal pump, which is submerged in waste near the tank bottom. The pump mixes, or slurries, the waste within the tank so that it may be transferred out of the tank. Tank 18F is a 1.3 million gallon, 85 foot diameter underground waste storage tank, which has no internal components such as cooling coils or structural supports. The tank contained a residual 47,000 gallons of nuclear waste, consisting of a gelatinous radioactive waste known as sludge and particulate zeolite. The prediction of the ADMP success was based on nearly twenty five years of research and the application of that research to slurry pump technology. Many personnel at SRS and Pacific Northwest National Laboratories (PNNL) have significantly contributed to these efforts. This report summarizes that research which is pertinent to the ADMP performance …
Date:
March 29, 2004
Creator:
LEISHEAR, ROBERTA
Object Type:
Article
System:
The UNT Digital Library
Tank 10H Saltcake Core Sample Analysis
In support of Low-Curie Salt (LCS) process validation at the Savannah River Site (SRS), Liquid Waste Disposition (LWD) has undertaken a program of tank characterization, including salt sampling. As part of this initiative, they sampled the surface and subsurface of Tank 10H saltcake using a series of three 12-inch long sample tubes. These tubes each contain 1-foot long segments of the saltcake from one location, representing the top three feet of saltcake. The primary objective of the characterization that will be useful to the selection and processing of the next waste tanks. Most important is the determination of the Cs-137 concentration and liquid retention properties of Tank 10H saltcake to confirm acceptability of processing. Additional chemical analyses are performed to provide information on salt elemental, ionic, and radiological composition to aid in assessment of the suitability of processing drained and dissolved material and in refining the information in the waste characterization system (WCS).
Date:
June 29, 2004
Creator:
Martino, Christopher J.
Object Type:
Report
System:
The UNT Digital Library
The taming of the Grid : virtual application services.
In this report we develop a view of the Grid based on the application service provider (ASP) model. This view enables the user to see the Grid as a collection of application services that can be published, discovered, and accessed in a relatively straightforward manner, hiding much of the complexity involved in using computational Grids and thus making it simpler and more accessible to a wider range of users. However, in order to satisfy the requirements of real-time scientific application clients, we combine the ASP model with representation of quality of service about the execution of services and the results they produce. Specifically, we focus on real-time, deadline-bound execution as the quality of service derived by a client. We describe an architecture implementing these ideas and the role of client and server in the context of the functionality we develop. We also describe preliminary experiments using an equilibrium fitting application for magnetic fusion in our architecture.
Date:
March 29, 2004
Creator:
Keahey, K & Motawi, K.
Object Type:
Report
System:
The UNT Digital Library
Effect of Growth Interruption on Surface Recombination Velocity in GaInAsSb/AlGaAsSb Heterostructures Grown by Organometallic Vapor Phase Epitaxy
The effects of growth interruption on the quality of GaInAsSb/AlGaAsSb heterostructures grown by organometallic vapor phase epitaxy are reported. In-situ reflectance monitoring and ex-situ characterization by high-resolution x-ray diffraction, 4K photoluminescence (PL), and time-resolved PL indicate that GaInAsSb is extremely sensitive to growth interruption time as well as the ambient atmosphere during interruption. By optimizing the interruption sequence, surface recombination velocity as low as 20 cm/s was achieved for GaInAsSb/AlGaAsSb double heterostructures.
Date:
April 29, 2004
Creator:
Wang, C. A.; Shiau, D. A.; Donetsky, D.; Anikeev, S.; Belenky, G. & Luryi, S.
Object Type:
Report
System:
The UNT Digital Library
IMPROVED IRON CATALYSTS FOR SLURRY PHASE FISCHER-TROPSCH SYNTHESIS
None
Date:
January 29, 2004
Creator:
Bukur, Dragomir B.; Carreto-Vazquez, Victor & Ma, Wen-Ping
Object Type:
Report
System:
The UNT Digital Library
Lattice Studies for CIRCE (Coherent InfraRed Center) at the ALS
CIRCE (Coherent InfraRed Center) at the Advanced Light Source, Lawrence Berkeley National Lab (LBNL), is a proposal for a new electron storage ring optimized for the generation of coherent synchrotron radiation (CSR) in the terahertz frequency range. One of the main requirement for this special mode of operation is the capability of the ring of operating at small momentum compaction values. In this regime, the longitudinal dynamics becomes strongly nonlinear and an accurate control of the higher order energy dependent terms of the momentum compaction is necessary. The lattice for CIRCE allows controlling the seterms up to the third order. The paper describes the lattice and presents the calculated performances in terms of momentum acceptance, dynamic aperture , lifetime and momentum compaction tune capabilities.
Date:
June 29, 2004
Creator:
Nishimura, Hiroshi; Robin, David; Sannibale, Fernando & Wan, Weishi
Object Type:
Article
System:
The UNT Digital Library
WAPDEG Analysis of Waste Package and Drip shield Degradation
As directed by ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]), an analysis of the degradation of the engineered barrier system (EBS) drip shields and waste packages at the Yucca Mountain repository is developed. The purpose of this activity is to provide the TSPA with inputs and methodologies used to evaluate waste package and drip shield degradation as a function of exposure time under exposure conditions anticipated in the repository. This analysis provides information useful to satisfy ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]) requirements. Several features, events, and processes (FEPs) are also discussed (Section 6.2, Table 15). The previous revision of this report was prepared as a model report in accordance with AP-SIII.10Q, Models. Due to changes in the role of this report since the site recommendation, it no longer contains model development. This revision is prepared as a scientific analysis in accordance with AP-SIII.9Q, ''Scientific Analyses'' and uses models previously validated in (1) ''Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material'' (BSC 2004 [DIRS 169985]); (2) ''General Corrosion and Localized Corrosion of Waste …
Date:
September 29, 2004
Creator:
Mon, K.
Object Type:
Report
System:
The UNT Digital Library