Serial/Series Title
Winter Fuels Report
5
Establishment of an Industry-Driven Consortium Focused on Improving the Production Performance of Domestic Stripper Wells Quarterly Report
3
Fiscal Year 2000
2
Fiscal Year 2001
2
Refinery Integration of By-Products from Coal-Derived Jet Fuels Progress Report
2
Science & Technology Review
2
ARM Facilities Newsletter
1
Active Cathodes for Super-High Power Density Solid Oxide Fuel Cells Through Space Charge Effects Quarterly Report
1
Application of Reservoir Characterization and Advanced Technology to Improve Recovery and Economics in a Lower Quality Shallow Shelf San Andres Reservoir Progress Report
1
Differential Soil Impedance Obstacle Detection Quarterly Report
1
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CP Violation in B Decays at the Tevatron
Between 1992 to 1996, the CDF and D0 detectors each collected data samples exceeding 100 pb{sup {minus}1} of p{bar p} collisions at {radical}s = 1.8 TeV at the Fermilab Tevatron. These data sets led to a large number of precision measurements of the properties of B hadrons including lifetimes, masses, neutral B meson flavor oscillations, and relative branching fractions, and to the discovery of the B{sub 0} meson. Perhaps the most exciting result was the first look at the CP violation parameter sin ({vert_bar}2{beta}){vert_bar} using the world's largest sample of fully reconstructed B{sup 0}/{bar B}{sup 0} {r_arrow} J/{psi}K{sub s}{sup 0} decays. A summary of this result is presented here. In the year 2000, the Tevatron will recommence p{bar p} collisions with an over order of magnitude expected increased in integrated luminosity (1 fb{sup {minus}1} per year). The CDF and D0 detectors will have undergone substantial upgrades, particularly in the tracking detectors and the triggers. With these enhancements, the Tevatron B physics program includes precision measurements of sin(2{beta}) and B{sub s}{sup 0} flavor oscillations, as well as studies of rare B decays that are sensitive to new physics. The studies of B{sub s}{sup 0} mesons will be particularly interesting as this …
Date:
September 17, 1999
Creator:
Kroll, I. Joseph
Object Type:
Article
System:
The UNT Digital Library
Neutron spectroscopy of high-density amorphous ice.
Vibrational spectra of high-density amorphous ice (hda-ice) for H{sub 2}O and D{sub 2}O samples were measured by inelastic neutron scattering. The measured spectra of hda-ice are closer to those for high-pressure phase ice-VI, but not for low-density ice-Ih. This result suggests that similar to ice-VI the structure of hda-ice should consist of two interpenetrating hydrogen-bonded networks having no hydrogen bonds between themselves.
Date:
July 17, 1998
Creator:
Kolesnikov, A. I.
Object Type:
Article
System:
The UNT Digital Library
Validating the role of AFVs in voluntary mobile source emission reduction programs.
Late in 1997, EPA announced new allowances for voluntary emission control programs. As a result, the US Department of Energy's (DOE) Clean Cities and other metro areas that have made an ongoing commitment to increasing participation by alternative fuel vehicles (AFVs) in local fleets have the opportunity to estimate the magnitude and obtain emission reduction credit for following through on that commitment. Unexpectedly large reductions in key ozone precursor emissions in key locations and times of the day can be achieved per vehicle-mile by selecting specific light duty AFV offerings from original equipment manufacturers (OEMs) in lieu of their gasoline-fueled counterparts. Additional benefit accrues from the fact that evaporative emissions of non-methane hydrocarbons (generated in the case of CNG, LNG, and LPG by closed fuel-system AFV technology) can be essentially negligible. Upstream emissions from fuel storage and distribution with the airshed of interest are also reduced. This paper provides a justification and outlines a method for including AFVs in the mix of strategies to achieve local and regional improvements in ozone air quality, and for quantifying emission reduction credits. At the time of submission of this paper, the method was still under review by the US EPA Office of Mobile …
Date:
March 17, 1999
Creator:
Santini, D. J. & Saricks, C. L.
Object Type:
Article
System:
The UNT Digital Library
Sorption of heavy metals and radionuclides on mineral surfaces in the presence of organic co-contaminants. 1997 annual progress report
'This project fits well within the overall objectives established by the Environmental Management and Science Program to promote long-term basic research that will provide the tools for more effective and lower cost remediation efforts at DOE sites where hazardous and radioactive wastes or contamination zones are present. In order to develop the necessary remediation technology it has been recognized that a fundamental understanding of the various chemical and physical factors associated with waste treatment and contaminant transport must be established. Some of the specific topics include waste pretreatment, volume reduction, immobilization, separation methods, the interactions of actinides and heavy metals with surfaces in the presence of organic residues and co-contaminants, contaminant transport in the environment, and long-term storage site assessment. This project has direct and potential application in all these areas. The interaction and partitioning of contaminant metals and radionuclides between solution and solid- surface phases is a fundamental issue for waste treatment and predicting contaminant transport in the environment. Many factors are involved in the functional relationships describing chemical reactivity and physical distribution of chemical species. These include modification of chemical behavior by the suite of chemical co-contaminants in a system. Organic complexing agents are common components of waste …
Date:
October 17, 1997
Creator:
Leckie, J. & Redden, G.
Object Type:
Report
System:
The UNT Digital Library
Barrier/Cu contact resistivity
The specific contact resistivity of Cu with ({alpha} + {beta})-Ta, TiN, {alpha}-W, and amorphous-Ta{sub 36}Si{sub 14}N{sub 50} barrier films is measured using a novel four-point-probe approach. Geometrically, the test structures consist of colinear sets of W-plugs to act as current and voltage probes that contact the bottom of a planar Cu/barrier/Cu stack. Underlying Al interconnects link the plugs to the current source and voltmeter. The center-to-center distance of the probes ranges from 3 to 200 {micro}m. Using a relation developed by Vu et al., a contact resistivity of roughly 7 {times} 10{sup {minus}9} {Omega} cm{sup 2} is obtained for all tested barrier/Cu combinations. By reflective-mode small-angle X-ray scattering, the similarity in contact resistivity among the barrier films may be related to interfacial impurities absorbed from the deposition process.
Date:
October 17, 1995
Creator:
Reid, J.S.; Nicolet, M.A.; Angyal, M.S.; Lilienfeld, D.; Shacham-Diamand, Y. & Smith, P.M.
Object Type:
Report
System:
The UNT Digital Library
Predictive Model and Methodology for Heat Treatment Distortion
The purpose of this project was to develop a modeling methodology and software tool to simulate and predict the results of heat treatment, especially distortion. In order to develop a simulation tool, significant technical, analytical, and experimental resources were needed. This task was too large and complex for just one company or organization to address. To this end, 4 national laboratories (Los Alamos National Laboratory, Lawrence Livermore National Laboratory, the Oak Ridge National Laboratory/Y-12 Plant, and Sandia National Laboratories) and many partners working through NCMS tackled this effort. The participants through NCMS were Ford Motor Company, General Motors Corporation, The Torrington Company, Deformation Control Technologies, The MacNeal-Schwindler Corp. IIT Research Institute, the Gear Research Institute, U.S. Benet Laboratories (Army), and the Colorado School of Mines. For the purpose of this report only those items pertinent to the Oak Ridge National Laboratory/Y-12 Plant participation in this CRADA will be highlighted along with those related items directly related to these specific efforts that were accomplished by the partners.
Date:
February 17, 1998
Creator:
Ludtka, G.M.
Object Type:
Report
System:
The UNT Digital Library
Hanford Contact-Handled Transuranic Drum Retrieval Project Planning Document
The Hanford Site is one of several US Department of Energy (DOE) sites throughout the US that has generated and stored transuranic (TRU) wastes. The wastes were primarily placed in 55-gallon drums, stacked in trenches, and covered with soil. In 1970, the Nuclear Regulatory Commission ordered that TRU wastes be segregated from other radioactive wastes and placed in retrievable storage until such time that the waste could be sent to a geologic repository and permanently disposed. Retrievable storage also defined container storage life by specifying that a container must be retrievable as a contamination-free container for 20 years. Hanford stored approximately 37,400 TRU containers in 20-year retrievable storage from 1970 to 1988. The Hanford TRU wastes placed in 20-year retrievable storage are considered disposed under existing Resource Conservation and Recovery Act (RCRA) regulations since they were placed in storage prior to September 1988. The majority of containers were 55-gallon drums, but 20-year retrievable storage includes several TRU wastes covered with soil in different storage methods.
Date:
November 17, 1998
Creator:
Demiter, J. A.
Object Type:
Report
System:
The UNT Digital Library
Examination of subaerially altered basaltic glass with TEM and EELS
We have examined the weathered surfaces of 720 year old Hawaiian basalt glasses that were recovered from a subaerial environment with high-resolution transmission electron microscopy (TEM) and energy filtered imaging and electron energy loss spectroscopy (EELS) techniques. Whereas the alteration products (palagonite) were physically detached from the underlying glass in most samples, a gel-like amorphous layer was observed adjacent to the glass in a few samples. To our knowledge, this is the first time a gel layer has been observed on weathered basalt. This is significant because analogous gel layers have been observed on nuclear waste glasses reacted in laboratory tests, and this demonstrates an important similarity in the mechanisms of the weathering of basalt and the corrosion of waste glasses.
Date:
June 17, 1998
Creator:
Luo, J. S. & Ebert, W. L.
Object Type:
Article
System:
The UNT Digital Library
The performance of the small-angle diffractometer, SAND at IPNS.
The time-of-flight small-angle diffractometer SAND has been serving the scientific user community since 1996. One notable feature of SAND is its capability to measure the scattered intensity in a wide Q (4{pi}sin{theta}/{lambda}, where 2{theta} is the scattering angle and {lambda} is the wavelength of the neutrons) range of 0.0035 to 0.5 {angstrom}{sup {minus}1} in a single measurement. The optical alignment system makes it easy to set up the instrument and the sample. The cryogenically cooled MgO filter reduces the fast neutrons over two orders of magnitude, while still transmitting over 70% of the cold neutrons. A drum chopper running at 15 Hz suppresses the delayed neutron background. SAND has a variety of ancillary equipment to control the sample environment. In this paper we describe the features of the SAND instrument, compare its data on a few standard samples with those measured at well established centers in the world, and display two scientific examples which take advantage of measuring data in a wide Q-range in a single measurement. With a new set of tight collimators the Q{sub min} can be lowered to 0.002 {angstrom}{sup {minus}1} and the presently installed high-angle bank of detectors will extend the Q{sub max} to 2 {angstrom}{sup …
Date:
July 17, 1998
Creator:
Thiyagarajan, P.
Object Type:
Article
System:
The UNT Digital Library
Thermal management in inertial fusion energy slab amplifiers
As the technology associated with the development of solid-state drivers for inertial fusion energy (IFE) has evolved, increased emphasis has been placed on the development of an efficient approach for managing the waste heat generated in the laser media. This paper addresses the technical issues associated with the gas cooling of large aperture slabs, where the laser beam propagates through the cooling fluid. It is shown that the major consequence of proper thermal management is the introduction of simple wedge, or beam steering, into the system. Achieving proper thermal management requires careful consideration of the geometry, cooling fluid characteristics, cooling flow characteristics, as well as the thermal/mechanical/optical characteristics of the laser media. Particularly important are the effects of cooling rate variation and turbulent scattering on the system optical performance. Helium is shown to have an overwhelming advantage with respect to turbulent scattering losses. To mitigate cooling rate variations, the authors introduce the concept of flow conditioning. Finally, optical path length variations across the aperture are calculated. A comparison of two laser materials (S-FAP and YAG) shows the benefit of a nearly a-thermal material on optical variations in the system.
Date:
July 17, 1995
Creator:
Sutton, S. B. & Albrecht, G. F.
Object Type:
Article
System:
The UNT Digital Library
Stress Voiding in IC Interconnects - Rules of Evidence for Failure Analysts
Mention the words ''stress voiding'', and everyone from technology engineer to manager to customer is likely to cringe. This IC failure mechanism elicits fear because it is insidious, capricious, and difficult to identify and arrest. There are reasons to believe that a damascene-copper future might be void-free. Nevertheless, engineers who continue to produce ICs with Al-alloy interconnects, or who assess the reliability of legacy ICs with long service life, need up-to-date insights and techniques to deal with stress voiding problems. Stress voiding need not be fearful. Not always predictable, neither is it inevitable. On the contrary, stress voids are caused by specific, avoidable processing errors. Analytical work, though often painful, can identify these errors when stress voiding occurs, and vigilance in monitoring the improved process can keep it from recurring. In this article, they show that a methodical, forensics approach to failure analysis can solve suspected cases of stress voiding. This approach uses new techniques, and patiently applies familiar ones, to develop evidence meeting strict standards of proof.
Date:
September 17, 1999
Creator:
FILTER, WILLIAM F.
Object Type:
Article
System:
The UNT Digital Library
Decay heat removal by natural convection - the RVACS system.
In conclusion, this work shows that for sodium coolant the reactor vessel auxiliary cooling system (RVACS) is an effective passive heat removal system if the reactor power does not exceed about 1600 MW(th). Its effectiveness is limited by the effective radiative heat transfer coefficient in the inner gap. In a lead cooled system, economic considerations may impose a lower limit.
Date:
August 17, 1999
Creator:
Tzanos, C. P.
Object Type:
Article
System:
The UNT Digital Library
Terascale spectral element algorithms and implementations.
We describe the development and implementation of an efficient spectral element code for multimillion gridpoint simulations of incompressible flows in general two- and three-dimensional domains. We review basic and recently developed algorithmic underpinnings that have resulted in good parallel and vector performance on a broad range of architectures, including the terascale computing systems now coming online at the DOE labs. Sustained performance of 219 GFLOPS has been recently achieved on 2048 nodes of the Intel ASCI-Red machine at Sandia.
Date:
August 17, 1999
Creator:
Fischer, P. F. & Tufo, H. M.
Object Type:
Article
System:
The UNT Digital Library
Stability of spheromaks compressed by liquid walls
We consider Rayleigh-Taylor instability of the liquid-plasma interface of a spheromak ignited by slow compression discussed previously. We conclude that instability may indeed occur despite the stabilizing influence of magnetic shear in the spheromak. If it occurs, instability would be greatest for modes concentrated toward the midplane. As for the cylindrical LINUS configuration, rotation about the geometric axis would stabilize these modes, but at the price of roughly doubling the input energy and reducing the gain. However, even in the absence of rotation, in a sphere instability occurs only at the end of compression near the stagnation point. Revised estimates of the fusion energy gain taking this brief period of instability into account still give, within the uncertainties, a gain G {approx} 20 for our earlier example with an input energy of 150 MJ and fusion yield of 3 GJ.
Date:
August 17, 1999
Creator:
Fowler, T K
Object Type:
Report
System:
The UNT Digital Library
High performance gamma measurements of equipment retrieved from Hanford high-level nuclear waste tanks
The cleanup of high level defense nuclear waste at the Hanford site presents several progressive challenges. Among these is the removal and disposal of various components from buried active waste tanks to allow new equipment insertion or hazards mitigation. A unique automated retrieval system at the tank provides for retrieval, high pressure washing, inventory measurement, and containment for disposal. Key to the inventory measurement is a three detector HPGe high performance gamma spectroscopy system capable of recovering data at up to 90% saturation (200,000 counts per second). Data recovery is based on a unique embedded electronic pulser and specialized software to report the inventory. Each of the detectors have different shielding specified through Monte Carlo simulation with the MCNP program. This shielding provides performance over a dynamic range of eight orders of magnitude. System description, calibration issues and operational experiences are discussed.
Date:
March 17, 1997
Creator:
Troyer, G. L.
Object Type:
Report
System:
The UNT Digital Library
What's in your bookmark? Green building information on the Web.
In listing web sites that are of special interest to the Affordable Comfort community, we will try to categorize sites in six major areas: Green Building Product Directories, Software Tools on the Web, Good Places for Learning, Health and Indoor Environment Information, Important Discussion Groups and E-mail Lists, and Sites of Sites. Since we can not help but leave out a great deal, we invite the reader to contact us for lists of sites that we could not include.
Date:
February 17, 1999
Creator:
Cavallo, J. D. & Iversen, M. R.
Object Type:
Article
System:
The UNT Digital Library
Lessons learned from applying VIM to fast reactor critical experiments
VIM is a continuous energy Monte Carlo code first developed around 1970 for the analysis of plate-type, fast-neutron, zero-power critical assemblies. In most respects, VIM is functionally equivalent to the MCNP code but it has two features that make uniquely suited to the analysis of fast reactor critical experiments: (1) the plate lattice geometry option, which allows efficient description of and neutron tracking in the assembly geometry, and (2) a statistical treatment of neutron cross section data in the unresolved resonance range. Since its inception, VIM`s capabilities have expanded to include numerous features, such as thermal neutron cross sections, photon cross sections, and combinatorial and other geometry options, that have allowed its use in a wide range of neutral-particle transport problems. The earliest validation work at Argonne National Laboratory (ANL) focused on the validation of VIM itself. This work showed that, in order for VIM to be a ``rigorous`` tool, extreme detail in the pointwise Monte Carlo libraries was needed, and the required detail was added. The emphasis soon shifted to validating models, methods, data and codes against VIM. Most of this work was done in the context of analyzing critical experiments in zero power reactor (ZPR) assemblies. The purpose …
Date:
May 17, 1995
Creator:
Schaefer, R.W.; McKnight, R.D. & Collins, P.J.
Object Type:
Article
System:
The UNT Digital Library
Stability of spheromaks compressed by liquid walls
We consider Rayleigh-Taylor instability of the liquid-plasma interface of a spheromak ignited by slow compression discussed previously. We conclude that instability may indeed occur despite the stabilizing influence of magnetic shear in the spheromak. If it occurs, instability would be greatest for modes concentrated toward the midplane. As for the cylindrical LINUS configuration, rotation about the geometric axis would stabilize these modes, but at the price of roughly doubling the input energy and reducing the gain. However, even in the absence of rotation, in a sphere instability occurs only at the end of compression near the stagnation point. Revised estimates of the fusion energy gain taking this brief period of instability into account still give, within the uncertainties, a gain G {approx} 20 for our earlier example with an input energy of 150 MJ and fusion yield of 3 GJ.
Date:
August 17, 1999
Creator:
Fowler, T K
Object Type:
Report
System:
The UNT Digital Library
Phase stability and grain growth in an Ag/Bi-2223 composite conductor prepared using fine-grained Bi-2223 as a precursor.
We have investigated the stability and microstructural transformability of the Bi-2223 phase in a silver-sheathed monofilament composite tape fabricated using fine-grained Bi{sub 1.7}Pb{sub 0.3}Sr{sub 1.9}Ca{sub 2.0}-Cu{sub 3.0}O{sub y} (Bi-2223) as the precursor powder. The fully formed Bi-2223 precursor was prepared using established procedures. The purpose of this study was to explore the prospects for growing textured, large-grain-size Bi-2223 from the fine-grained precursor by process parameter perturbations. These perturbations included thermal ramp up variations, programmed heat treatment temperature and oxygen pressure fluctuations, and parameter manipulations during cool-down. Our results show that the types of heat treatments used in conventional oxide-powder-in-tube (OPIT) processing do not facilitate Bi-2223 grain growth when the precursor powder is preconcerted Bi-2223. We also observed that the Bi-2223 partially. decomposed during conventional thermal ramp-up in 0.075 atm O{sub 2}, but that this decomposition can be inhibited by ramping up in a reduced oxygen pressure. A pathway was found for back-reacting the fine-grained Bi-2223 (to Bi-2212, Bi-2201 and nonsuperconducting secondary phases), then reforming large-grained Bi-2223 in a colony microstructure having some distinct differences from that produced during conventional OPIT processing.
Date:
September 17, 1998
Creator:
Merchant, N. N.
Object Type:
Article
System:
The UNT Digital Library
Fluoro-Carbonate Solvents for Li-Ion Cells
A number of fluoro-carbonate solvents were evaluated as electrolytes for Li-ion cells. These solvents are fluorine analogs of the conventional electrolyte solvents such as dimethyl carbonate, ethylene carbonate, diethyl carbonate in Li-ion cells. Conductivity of single and mixed fluoro carbonate electrolytes containing 1 M LiPF{sub 6} was measured at different temperatures. These electrolytes did not freeze at -40 C. We are evaluating currently, the irreversible 1st cycle capacity loss in carbon anode in these electrolytes and the capacity loss will be compared to that in the conventional electrolytes. Voltage stability windows of the electrolytes were measured at room temperature and compared with that of the conventional electrolytes. The fluoro-carbon electrolytes appear to be more stable than the conventional electrolytes near Li voltage. Few preliminary electrochemical data of the fluoro-carbonate solvents in full cells are reported in the literature. For example, some of the fluorocarbonate solvents appear to have a wider voltage window than the conventional electrolyte solvents. For example, methyl 2,2,2 trifluoro ethyl carbonate containing 1 M LiPF{sub 6} electrolyte has a decomposition voltage exceeding 6 V vs. Li compared to <5 V for conventional electrolytes. The solvent also appears to be stable in contact with lithium at room temperature.
Date:
September 17, 1999
Creator:
Nagasubramanian, Ganesan
Object Type:
Article
System:
The UNT Digital Library
Vapor Phase Detection Using Chemi-Resistor Sensor Arrays
This paper focuses on two main areas: understanding sensor response times so as to obtain improved time response in the field when needed for vapor tracking and classification, and improved theoretical understanding of the sensor response properties that generate the pattern on the array in response to a given analyte.
Date:
February 17, 1999
Creator:
Lewis, Nathan S.
Object Type:
Report
System:
The UNT Digital Library
Wind Power Today: 1998 Wind Energy Program Highlights
The US Department of Energy's Office of Energy Efficiency and Renewable Energy manages the Federal Wind Energy Program. The mission of the program is to help the US wind industry to complete the research, testing, and field verification needed to fully develop advanced wind technologies that will lead the world in cost-effectiveness and reliability. This publication, printed annually, provides a summary of significant achievements in wind energy made during the previous calendar year. Articles include wind energy in the Midwest, an Alaskan wind energy project, the US certification program, structural testing, and the federal program in review.
Date:
June 17, 1999
Creator:
Tromly, K.
Object Type:
Book
System:
The UNT Digital Library
Noble gas isotope measurements for spent nuclear fuel reprocessing. IAEA Task 90/0A211 interim report
The nuclear fission of actinides in reactor fuel produces large quantities of Kr and Xe as fission products. Because of the high levels of fission Kr and Xe, sample collection and analysis of noble gases for spent fuel diagnostic measurements is a simple, straight-forward technique. In modern reprocessing plants with continuous dissolvers, it will not be possible to use traditional methods for isolating input batches of fuel. This study investigates the feasibility of using noble gas isotope abundance measurements (isotope correlation techniques - ICT) to solve safeguards requirements. Noble gas measurements might be able to provide an independent analysis of Pu contained within dissolves fuel, on an individual fuel assembly basis. The isotopic composition of Kr and Xe in spent fuel reflects both the composition (isotope abundance ratios) of the fission products and the effects of neutron capture on those fission products. We have reviewed the available literature for noble gas analyses of spent reactor fuel. While references are made to noble gas isotope correlations over the last 20 years, we have found little if any detailed analysis of large data sets. The literature search did find several useful reports. Of these papers, one is particularly useful for evaluating noble …
Date:
February 17, 1993
Creator:
Hudson, G. B.
Object Type:
Report
System:
The UNT Digital Library
Measuring explosive non-ideality
The sonic reaction zone length may be measured by four methods: (1) size effect, (2) detonation front curvature, (3) crystal interface velocity and (4) in-situ gauges. The amount of data decreases exponentially from (1) to (4) with there being almost no gauge data for prompt detonation at steady state. The ease and clarity of obtaining the reaction zone length increases from (1) to (4). The method of getting the reaction zone length, <x{sub e}>, is described for the four methods. A measure of non-ideality is proposed: the reaction zone length divided by the cylinder radius. N = <x{sub e}>/R{sub o}. N = 0 for true ideality. It also decreases with increasing radius as it should. For N < 0.10, an equilibrium EOS like the JWL may be used. For N > 0.10, a time-dependent description is essential. The crystal experiment, which measures the particle velocity of an explosive-transparent material interface, is presently rising in importance. We examine the data from three experiments and apply: (1) an impedance correction that transfers the explosive C-J particle velocity to the corresponding value for the interface, and (2) multiplies the interface time by 3/4 to simulate the explosive speed of sound. The result is …
Date:
February 17, 1999
Creator:
Souers, P C
Object Type:
Article
System:
The UNT Digital Library