Degree Level

Review of the US Department of Energy Classified Visits Program (open access)

Review of the US Department of Energy Classified Visits Program

This review examines the US Department of Energy (DOE) Classified Visits Program, which is administered by the Office of Safeguards and Security. The overall purpose of this analysis is to (1) ensure that DOE policy and implementing procedures are appropriate to maintain US national security intentions; (2) evaluate the effectiveness of the process used across the DOE complex; and (3) recommend changes which will enhance the overall efficiency of the process while maintaining the program's integrity.
Date: July 1, 1992
Creator: Martin, S. W.; Killinger, M. H. & Segura, M. A.
Object Type: Report
System: The UNT Digital Library
Influence of surface defects and local structure on oxygenate reaction pathways over metal oxide surfaces (open access)

Influence of surface defects and local structure on oxygenate reaction pathways over metal oxide surfaces

Work during the last year (August 1991 to July 1992) has concentrated on completing the previously initiated studies of the surface chemistry of C{sub 1} oxygenates on particularly methanol SnO{sub 2}(110) and beginning studies of C{sub 2}oxygenate surface chemistry. During the remaining six months of the second budget period, the C{sub 2} studies will be continued.
Date: July 1992
Creator: Cox, David F.
Object Type: Report
System: The UNT Digital Library
Ion-channeling observation of correlated atomic displacements below Tc in YBa sub 2 Cu sub 3 O sub 7-x and Pb-doped Bi sub 2 Sr sub 2 CaCu sub 2 O sub x (open access)

Ion-channeling observation of correlated atomic displacements below Tc in YBa sub 2 Cu sub 3 O sub 7-x and Pb-doped Bi sub 2 Sr sub 2 CaCu sub 2 O sub x

Temperature dependent studies of ion channeling in high-quality, high-Tc single-crystals are summarized. The measurements revealed an abrupt change across Tc in displacements in the a-b plane of the Cu(I and 2) and 0(4) atoms; normal Debye-like'' vibrations were found for the Y and Ba atoms. The anomalous atomic displacements were found for both proton and He channeling, and manifested themselves as an abrupt increase in the critical angle and a simultaneous decrease in the minimum yield. The anomalous change in Cu-0 displacements shifted directly with stoichiometry-induced changes in Tc, implying a causal fink between the observed phonon anomaly and the superconducting state. An apparently identical anomaly was found in (Bi{sub 1.7}Pb{sub 0.3})Sr{sub 2}CaCu{sub 2}O{sub x}, indicating that it is a general feature of high-T, superconductivity. A comparison with other experimental measurements in YBa{sub 2}Cu{sub 3}O{sub 7-x}, including a detailed neutron diffraction study, indicates that the anomaly is not due to an overall reduction in average vibrational amplitude, but arises instead from a strongly correlated sequence of Cu(1 and 2) and 04 displacements that appears with the onset of superconductivity. These strongly correlated displacements are either dynamic, or they are static distortions that fail to preserve the overall crystal symmetry.
Date: July 1, 1992
Creator: Rehn, L. E.; Sharma, R. P. & Baldo, P. M.
Object Type: Article
System: The UNT Digital Library
Fusion programs in Applied Plasma Physics (open access)

Fusion programs in Applied Plasma Physics

The Applied Plasma Physics (APP) program at General Atomics (GA) described here includes four major elements: (a) Applied Plasma Physics Theory Program, (b) Alpha Particle Diagnostic, (c) Edge and Current Density Diagnostic, and (d) Fusion User Service Center (USC). The objective of the APP theoretical plasma physics research at GA is to support the DIII-D and other tokamak experiments and to significantly advance our ability to design a commercially-attractive fusion reactor. We categorize our efforts in three areas: magnetohydrodynamic (MHD) equilibria and stability; plasma transport with emphasis on H-mode, divertor, and boundary physics; and radio frequency (rf). The objective of the APP alpha particle diagnostic is to develop diagnostics of fast confined alpha particles using the interactions with the ablation cloud surrounding injected pellets and to develop diagnostic systems for reacting and ignited plasmas. The objective of the APP edge and current density diagnostic is to first develop a lithium beam diagnostic system for edge fluctuation studies on the Texas Experimental Tokamak (TEXT). The objective of the Fusion USC is to continue to provide maintenance and programming support to computer users in the GA fusion community. The detailed progress of each separate program covered in this report period is described …
Date: July 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Present state-of-the-art of two-phase flow model calculations (open access)

Present state-of-the-art of two-phase flow model calculations

Argonne National Laboratory (ANL) has developed two- and three-dimensional computer programs to predict hydrodynamics in complex fluid/solids systems including atmospheric and pressurized bubbling and circulating fluidized-bed combustors and gasifiers, concentrated suspension (slurry) piping systems and advanced particle-bed reactors for space-based applications, for example. The computer programs are based upon phenomenological mechanistic models and can predict frequency of bubble formation, bubble size and growth, bubble frequency and rise-velocity, solids volume fraction, gas and solids velocities and low dimension chaotic attracters. The results of these hydrodynamic calculations are used as inputs to mechanistic models to predict heat transfer and erosion and have been used to produce simplified models and guidelines to assist in design and scaling. An extensive coordinated effort involving industry, government, and university laboratory data has served to validate the various models. Babcock Wilcox (B W), in close collaboration with ANL, has developed the three dimensional FORCE2 computer program which is both transient as well as steady-state.
Date: July 1, 1992
Creator: Lyczkowski, R. W.; Ding, Jianmin & Bouillard, J. X.
Object Type: Article
System: The UNT Digital Library
600 kV modulator design for the SLAC Next Linear Collider Test Accelerator (open access)

600 kV modulator design for the SLAC Next Linear Collider Test Accelerator

Preliminary design for the SLAC Next Linear Collider Test Accelerator (NLCTA) requires a pulse power source to produce a 600 kV, 600 A, 1.4 {mu}s, 0.1% flat top pulse with rise and fall times of approximately 100 ns to power an X-Band klystron with a microperveance of 1.25 at {approx} 100 MW peak RF power. The design goals for the modulator, including those previously listed, are peak modulator pulse power of 340 MW operating at 120 Hz. A three-stage darlington pulse-forming network, which produces a >100 kV, 1.4 {mu}s pulse, is coupled to the klystron load through a 6:1 pulse transformer. Careful consideration of the transformer leakage inductance, klystron capacitance, system layout, and component choice is necessary to produce the very fast rise and fall times at 600 kV operating continuously at 120 Hz.
Date: July 1, 1992
Creator: Harris, K.; de Lamare, J.; Nesterov, V. & Cassel, R.
Object Type: Article
System: The UNT Digital Library
Progress report on modeling studies: Natural state conditions and exploitation of the Dachny geothermal reservoir, Mutnovsky hydrothermal system, Kamchatka, Russia (open access)

Progress report on modeling studies: Natural state conditions and exploitation of the Dachny geothermal reservoir, Mutnovsky hydrothermal system, Kamchatka, Russia

The spatial distribution of pre-exploitation conditions (e.g. temperature and pressure distributions, liquid and vapor saturations, circulation characteristics of high-temperature fluids) in the Dachny site of the Mutnovsky hydrothermal system, obtained earlier using a 3-D mapping method (Kiryukhin et al, 1991), are revised on the basis of natural state simulations performed with the computer code TOUGH2 (Pruess, 1991). A 3-D model of the natural state conditions at the Dachny site was developed. The fine-tuning of the model has been achieved by comparing model results to the observations made in geothermal wells 1, 24, 01, 016 and 26 during flow tests conducted during 1983--1988. The behavior of these five wells in response to two exploitation scenarios, one with no reinjection, the other with 100 kg/s of liquid injection into well 027, was also computed.
Date: July 1, 1992
Creator: Kiryukhin, A. V.
Object Type: Report
System: The UNT Digital Library
Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres (open access)

Study of the atmospheric chemistry of radon progeny in laboratory and real indoor atmospheres

This report covers the second year of the 28 month grant current grant to Clarkson University to study the chemical and physical behavior of the polonium 218 atom immediately following its formation by the alpha decay of radon. Because small changes in size for activity result in large changes in the delivered dose per unit exposure, this behavior must be understood if the exposure to radon progeny and it dose to the cells in the respiratory tract are to be fully assessed. Two areas of radon progeny behavior are being pursued; laboratory studies under controlled conditions to better understand the fundamental physical and chemical process that affect the progeny's atmospheric behavior and studies in actual indoor environments to develop a better assessment of the exposure of the occupants of that space to the size and concentration of the indoor radioactive aerosol. This report describes the progress toward achieving these objectives.
Date: July 1, 1992
Creator: Hopke, P. K.
Object Type: Report
System: The UNT Digital Library
Studies of Plasma Transport (open access)

Studies of Plasma Transport

None
Date: July 17, 1991
Creator: Malmberg, J. H.; O'Neil, T. M. & Driscoll, C. F.
Object Type: Report
System: The UNT Digital Library
Magneto-optic characterizations of superlattices and wedged sandwiches with oscillatory interlayer magnetic coupling (open access)

Magneto-optic characterizations of superlattices and wedged sandwiches with oscillatory interlayer magnetic coupling

Three examples of magnetic coupling across metallic spacer layers are considered. Fe/Nb sputtered superlattices are observed to have as many as five antiferromagnetic oscillations, but a weak magnetoresistive anomaly. Epitaxial trilayers of Fe/Mo/Fe grown on Mo(100) and Co/Cu/Co grown on Cu(100) are observed to have short- and long-period oscillations, respectively. The trilayers are grown with wedged spacer layers and characterized in-situ by means of the magneto-optic Kerr effect.
Date: July 1, 1992
Creator: Bader, S. D.
Object Type: Article
System: The UNT Digital Library
A look at scalable dense linear algebra libraries (open access)

A look at scalable dense linear algebra libraries

We discuss the essential design features of a library of scalable software for performing dense linear algebra computations on distributed memory concurrent computers. The square block scattered decomposition is proposed as a flexible and general-purpose way of decomposing most, if not all, dense matrix problems. An object- oriented interface to the library permits more portable applications to be written, and is easy to learn and use, since details of the parallel implementation are hidden from the user. Experiments on the Intel Touchstone Delta system with a prototype code that uses the square block scattered decomposition to perform LU factorization are presented and analyzed. It was found that the code was both scalable and efficient, performing at about 14 Gflop/s (double precision) for the largest problem considered.
Date: July 1, 1992
Creator: Dongarra, J. J.; van de Geijn, R. & Walker, D. W.
Object Type: Report
System: The UNT Digital Library
A model for analytical performance prediction of hypervapotron (open access)

A model for analytical performance prediction of hypervapotron

A hypervapotron is a water-cooled device which combines the advantages of finned surfaces with the large heat transfer rates possible during boiling heat transfer. Hypervapotrons have been used as beam dumps in the past and plans are under way to use them for divertor cooling in the Joint European Torus (JET). Experiments at JET have shows that a surface heat flux of 25 MW/m{sup 2} can be achieved in hypervapotrons. This performance makes such a device very attractive for cooling of divertor of the International Thermonuclear Experimental Reactor (ITER). This paper presents an analytical method to predict the thermal performance of the hypervapotrons. Preliminary results show an excellent agreement between experimental results and analytical prediction over a wide range of flow velocities, pressures, subcooling temperatures and heat fluxes. This paper also presents the predicted performance of hypervapotron made of materials other than copper. After further development and verification, the analytical method could be used for optimizing designs and performance prediction.
Date: July 1, 1992
Creator: Baxi, C. B. (General Atomics, San Diego, CA (United States)) & Falter, H. (JET Joint Undertaking, Abingdon (United Kingdom))
Object Type: Article
System: The UNT Digital Library
An overview of spin physics (open access)

An overview of spin physics

Spin physics is playing an increasingly important role in high energy experiments and theory. This review looks at selected topics in high energy spin physics that were discussed at the 9th International Symposium on High Energy Spin Physics at Bonn in September 1990.
Date: July 1, 1991
Creator: Prescott, C. Y.
Object Type: Article
System: The UNT Digital Library
Radiological survey results at 5 Porter Street, Beverly, Massachusetts (VB019) (open access)

Radiological survey results at 5 Porter Street, Beverly, Massachusetts (VB019)

At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory conducted a radiological survey at 5 Porter Street, Beverly, Massachusetts. The survey was performed in May 1991. The purpose of the survey was to determine if uranium from work performed under government contract at the former Ventron facility had migrated off-site to neighboring areas. The survey included a surface gamma scan and the collection of soil samples for radionuclide analyses. Results of the survey demonstrated no radionuclide concentrations or radiation measurements in excess of the DOE Formerly Utilized Site Remedial Action Program guidelines.
Date: July 1, 1992
Creator: Foley, R. D. & Johnson, C. A.
Object Type: Report
System: The UNT Digital Library
The California Institute for Energy Efficiency multiyear research plan, 1992--1996 (open access)

The California Institute for Energy Efficiency multiyear research plan, 1992--1996

The mission of the California Institute for Energy Efficiency (CIEE) is to coordinate, plan, and implement a statewide program of medium- to long-term (five to fifteen years) applied research aimed at advancing the energy efficiency and productivity of all end-use sectors in California. The focus of CIEE's multiyear research and development (R D) program is to benefit California's ratepayers within the context of the state's energy, environmental, and economic needs and priorities. This context includes the current research efforts of CIEE's sponsors, of significant national R D organizations, and of industry. CIEE's 1992--1996 Multiyear Research Plan guides the Institute's research development, research management, and technology transfer efforts. The Plan briefly describes CIEE's current R D program and introduces potential R D initiatives that are responsive to California's unmet energy efficiency needs. In 1992, CIEE is planning, funding, and managing $5 million in multiyear research, exploratory research, Director's discretionary research, and technology transfer activities. The Institute's 1992 effort includes $3.6 million in multiyear research conducted in the Building Energy Efficiency, Air Quality Impacts of Energy Efficiency, and End-Use Resource Planning programs and $1 million in exploratory and Director's discretionary research. During the period 1992 to 1996, CIEE will continue to conduct …
Date: July 1, 1992
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Factors affecting transport of bacterial cells in porous media (open access)

Factors affecting transport of bacterial cells in porous media

This study focused on identification of factors associated with the biology, chemistry, and hydrology of the subsurface environment that control bacterial transport through that habitat. We determined that control is a complex interaction of biological factors such as cell size and hydrophobicity, geochemical factors such as ionic strength of the ground water, and hydrological factors including the presence of preferred flow paths in the porous medium.
Date: July 1, 1992
Creator: Mills, A. L.; Herman, J. S. & Hornberger, G. M.
Object Type: Report
System: The UNT Digital Library
Preliminary investigation of the potential for transient vapor release events during in situ vitrification based on thermal- hydraulic modeling (open access)

Preliminary investigation of the potential for transient vapor release events during in situ vitrification based on thermal- hydraulic modeling

This study investigates a possible cause of molten glass displacements that occurred during two recent in situ vitrification (ISV) tests. The study was conducted for the US Department of Energy by Pacific Northwest Laboratory. It is hypothesized that these glass displacements are caused by large gas bubbles rising up through the ISV melt and bursting at its surface. These bubbles cause the molten surface to upwell and possibly overflow. When the bubbles burst, molten glass is thrown from the melt surface and the volume of gas contained in the bubble is released into the hood. Both of these phenomena are undesirable because the molten soil ejected from the melt is dangerous to operating personnel and can damage equipment. The sudden gas release can cause a temporary pressurization of the hood, allowing potentially contaminated gas to escape to the atmosphere. This study attempts to explain the conditions necessary for formation of large gas bubbles in the melt so that future glass displacements can be avoided.
Date: July 1, 1992
Creator: Roberts, J. S.; Woosley, S. L.; Lessor, D. L. & Strachan, C.
Object Type: Report
System: The UNT Digital Library
The effects of moisture on the microstructure of cement-based materials (open access)

The effects of moisture on the microstructure of cement-based materials

New experimental techniques that allow the precise measurement of drying shrinkage of cement-based materials within the Environmental Scanning Electron Microscope have been developed. Accuracies of approximately 1% can be obtained on images as small as 20 {times} 20 pixels. Preliminary results on the shrinking of these materials has been obtained and quantitatively analyzed to produce maps'' of the deformation process. Samples have been dried from saturation in environments which a approximately 25% relative humidity, and deformation has been evaluated for the model materials C3S, C3A, and C4AF. The bulk of the effort during this initial period has been to establish the sophisticated experimental techniques which are necessary to pursue the proposed research. In this respect, the initial stage has been extremely successful and we have begun the process of detailed, methodical, documentation of the deformation of both the model materials and ordinary portland cement paste. The possibility of measuring the constraining effects of other phases such as aggregate is now being investigated. These initial results have resulted in four publications. Two publications are of a review nature and two are the reporting our new experimental technique, and initial results. The latter two are being submitted to peer reviewed journals.
Date: July 15, 1992
Creator: Jennings, H. M.
Object Type: Report
System: The UNT Digital Library
Selected case studies of technology transfer from mission-oriented applied research (open access)

Selected case studies of technology transfer from mission-oriented applied research

The US Department of Energy (DOE) Advanced Industrial Concepts Division (AICD) under the Office of Industrial Technologies (OIT) supports interdisciplinary applied research and exploratory development that will expand the knowledge base to enable industry to improve its energy efficiency and its capability to use alternative energy resources. AICD capitalizes on scientific and technical advances from the United States and abroad, applying them to address critical technical needs of American industry. As a result, AICD research and development products are many and varied, and the effective transfer of these products to diverse targeted users requires different strategies as well. This paper describes the products of AICD research, how they are transferred to potential users, and how actual transfer is determined.
Date: July 1, 1992
Creator: Daellenbach, K. K.; Watts, R. L.; Young, J. K. (Pacific Northwest Lab., Richland, WA (United States)) & Abarcar, R. B. (Energetics, Inc., Columbia, MD (United States))
Object Type: Report
System: The UNT Digital Library
Adsorption of water vapor on reservoir rocks (open access)

Adsorption of water vapor on reservoir rocks

Progress is reported on: adsorption of water vapor on reservoir rocks; theoretical investigation of adsorption; estimation of adsorption parameters from transient experiments; transient adsorption experiment -- salinity and noncondensible gas effects; the physics of injection of water into, transport and storage of fluids within, and production of vapor from geothermal reservoirs; injection optimization at the Geysers Geothermal Field; a model to test multiwell data interpretation for heterogeneous reservoirs; earth tide effects on downhole pressure measurements; and a finite-difference model for free surface gravity drainage well test analysis.
Date: July 1, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Design of a compact permanent magnet Cyclotron Mass Spectrometer for the detection and measurement of trace isotopes (open access)

Design of a compact permanent magnet Cyclotron Mass Spectrometer for the detection and measurement of trace isotopes

A technique for the detection of trace amounts of rare isotopes, Cyclotron mass Spectrometry (CMS), is described. This technique uses the relationships between particle mass, charge, magnetic field strength and cyclotron orbital frequency to provide high mass resolution. The instrument also has high sensitivity and is capable of measuring isotopes with abundances of < 10{sub {minus} 12}. Improvements now being implemented will lead to further increases in the sensitivity and enhance operating parameters such as cost, portability, and sample throughput.
Date: July 1, 1992
Creator: Young, A. T.; Bertsche, K. J.; Clark, D. J.; Halbach, K.; Kunkel, W. B.; Leung, K. N. et al.
Object Type: Article
System: The UNT Digital Library
DUPLEX: A molecular mechanics program in torsion angle space for computing structures of DNA and RNA (open access)

DUPLEX: A molecular mechanics program in torsion angle space for computing structures of DNA and RNA

DUPLEX produces energy minimized structures of DNA and RNA of any base sequence for single and double strands. The smallest subunits are deoxydinucleoside monophosphates, and up to 12 residues, single or double stranded can be treated. In addition, it can incorporate NMR derived interproton distances an constraints in the minimizations. Both upper and lower bounds for these distances can be specified. The program has been designed to run on a UNICOS Cray supercomputer, but should run, albeit slowly, on a laboratory computer such as a VAX or a workstation.
Date: July 1, 1992
Creator: Hingerty, B. E.
Object Type: Report
System: The UNT Digital Library
Enhancing low severity coal liquefaction reactivity using mild chemical pretreatment (open access)

Enhancing low severity coal liquefaction reactivity using mild chemical pretreatment

In this paper, we describe results from a study in which mild chemical pretreatment of coal has been used to enhance low severity liquefaction reactivity. We have found that ambient pretreatment of eight Argonne coals using methanol and a trace amount of hydrochloric acid improves THF-soluble conversions 24.5 wt% (maf basis) for Wyodak subbituminous coal and 28.4 wt% for Beulah-Zap lignite with an average increase of 14.9 wt% for liquefaction of the eight coals at 623 K (350{degree}C) reaction temperature and 30 min. reaction time. Similar enhancement results occurred using, hexane or acetone in place of methanol. Pretreatment with methanol and HCI separately indicated that both reagents were necessary to achieve maximum liquefaction improvement. Acid concentration was the most important pretreatment variable studied; liquefaction reactivity increased with increasing acid concentration up to 2 vol%. No appreciable effect on reactivity was observed at higher acid concentrations. Although vapor phase alcohol/HCI mixtures have been shown to partially alkylate bituminous coals, analysis of Wyodak and Illinois {number sign}6 coal samples indicated that no organic phase alteration occurred during pretreatment; however, over 90 wt% of the calcium was removed from each coal. Calcium is thought to catalyze retrogressive reactions during coal pyrolysis, and thus …
Date: July 13, 1992
Creator: Shams, K. G.; Miller, R. L. & Baldwin, R. M.
Object Type: Report
System: The UNT Digital Library
Hanford Environmental Dose Reconstruction Project (open access)

Hanford Environmental Dose Reconstruction Project

The objective of the Hanford Environmental Dose Reconstruction (HEDR) Project is to estimate the radiation doses that individuals and populations could have received from nuclear operations at Hanford since 1944. The TSP consists of experts in environmental pathways, epidemiology, surface-water transport, ground-water transport, statistics, demography, agriculture, meteorology, nuclear engineering, radiation dosimetry, and cultural anthropology. Included are appointed technical members representing the states of Oregon, Washington, and Idaho, a representative of Native American tribes, and an individual representing the public. The project is divided into the following technical tasks. These tasks correspond to the path radionuclides followed from release to impact on humans (dose estimates): Source terms, environmental transport, environmental monitoring data, demography, food consumption, and agriculture, and environmental pathways and dose estimates. Progress is discussed.
Date: July 1, 1992
Creator: McMakin, A. H.; Cannon, S. D. & Finch, S. M. (comps.)
Object Type: Report
System: The UNT Digital Library