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Transport in compact tori (open access)

Transport in compact tori

The parameter B/sub e//nr/sub p/ (here, B/sub e/ is applied magnetic field strength, nr/sub p/ is the plasma density-radius product) is proposed as a key parameter for spheromak heating studies. If B/sub e//nr/sub p/ is too large, increased magnetic fluctuations limit heating; low B/sub e//nr/sub p/ value results in excessive radiation losses. An optimum range appears to be B/sub e//nr/sub p/ approx. 1 to 5 x 10/sup -20/ Wb.
Date: February 23, 1983
Creator: Miley, G. H.
Object Type: Article
System: The UNT Digital Library
Determination of the rate and efficiency of nitrogen transfer from phytoplankton to zooplankton using nitrogen-15 as a tracer. Final report (open access)

Determination of the rate and efficiency of nitrogen transfer from phytoplankton to zooplankton using nitrogen-15 as a tracer. Final report

The rate of assimilated nitrogen transfer from phytoplankton to zooplankton was measured under field conditions for natural mixed zooplankton populations using a nitrogen-15 tracer technique. The variability in rates, which ranged from 0.261 to 1.792 gram-atoms of phytoplankton nitrogen/gram-atoms of zooplankton nitrogen/24 hours, are thought to reflect a variability in the age frequency distribution of the zooplankton population. The data were used to calculate assimilation efficiencies which were found to range from 25.4 to 66.1 percent. The efficiency of 66.1 percent was taken to be the most accurate measurement for reasons discussed in the text.
Date: February 23, 1976
Creator: Harris, V M
Object Type: Report
System: The UNT Digital Library
DT fusion neutron irradiation of BPNL graphite irradiation capsule, LLL niobium, and LLL SiC crystals (open access)

DT fusion neutron irradiation of BPNL graphite irradiation capsule, LLL niobium, and LLL SiC crystals

The experimental procedure for irradiation testing of the above specimens is presented. No results are given. (MOW)
Date: February 23, 1976
Creator: MacLean, S. C.
Object Type: Report
System: The UNT Digital Library
Quantitative analysis of thin foils using backscattering measurements. [He implants in Pd; composite Al/parylene] (open access)

Quantitative analysis of thin foils using backscattering measurements. [He implants in Pd; composite Al/parylene]

Backscattering of 1.25-MeV protons and alpha particles from thin foils is used for a nondestructive quantitative elemental analysis of thin foils. The detection of helium that had previously been implanted into a 1350 A palladium foil and the analysis of a composite aluminum and parylene foil are presented as examples of this technique.
Date: February 23, 1971
Creator: Mervine, L. R.; Der, R. C.; Fortner, R. J.; Kavanagh, T. M. & Khan, J. M.
Object Type: Report
System: The UNT Digital Library
Equilibrium water vapor pressure and total moisture content measurements on TATB (open access)

Equilibrium water vapor pressure and total moisture content measurements on TATB

Equilibrium water vapor pressure and total moisture content were measured for samples of TATB-10 percent Kel-F, TATB-6 percent Estane, and TATB-9 percent Viton in a temperature range from 296 to 365/sup 0/K. Heats of vaporization were obtained for temperatures from 296 to 333/sup 0/K. Below 333/sup 0/K the water in the samples behaved as dissolved water and the Clausius-Clapeyron equation was applicable, while above 333/sup 0/K the water dissolved in the samples became very mobile and for practical purposes it was considered to be available in its entirety in the gas phase. The total moisture content of the samples was found to be <0.0021, 0.0102, and 0.0165 wt. percent for TATB-Kel-F, TATB-Estane, and TATB-Viton, respectively. The data indicate that the transport of water in the samples was controlled by the permeation characteristics of the binders. Fair agreement was found between published relative permeation constants for the three binders and those derived from the experimental results.
Date: February 23, 1976
Creator: Colmenares, C. & McDavid, L. C.
Object Type: Report
System: The UNT Digital Library
Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6 (open access)

Index to Nuclear Safety. A technical progress review by chronology, permuted title, and author. Vol. 11, No. 1--Vol. 17, No. 6

This index to Nuclear Safety covers articles in Nuclear Safety Vol. 11, No. 1 (Jan.-Feb. 1970), through Vol. 17, No. 6 (Nov.-Dec. 1976). The index includes a chronological list of articles (including abstract) followed by KWIC and Author Indexes. Nuclear Safety, a bimonthly technical progress review prepared by the Nuclear Safety Information Center, covers all safety aspects of nuclear power reactors and associated facilities. The index lists over 350 technical articles in the last six years of publication.
Date: February 23, 1977
Creator: Cottrell, W. B. & Klein, A.
Object Type: Report
System: The UNT Digital Library
COG validation: SINBAD Benchmark Problems (open access)

COG validation: SINBAD Benchmark Problems

We validated COG, a 3D Monte Carlo radiation transport code, against experimental data and MNCP4C simulations from the Shielding Integral Benchmark Archive Database (SINBAD) compiled by RSICC. We modeled three experiments: the Osaka Nickel and Aluminum sphere experiments conducted at the OKTAVIAN facility, and the liquid oxygen experiment conducted at the FNS facility. COG results are in good agreement with experimental data and generally within a few % of MCNP results. There are several possible sources of discrepancy between MCNP and COG results: (1) the cross-section database versions are different, MCNP uses ENDFB VI 1.1 while COG uses ENDFB VIR7, (2) the code implementations are different, and (3) the models may differ slightly. We also limited the use of variance reduction methods when running the COG version of the problems.
Date: February 23, 2004
Creator: Lent, E M; Sale, K E; Buck, R M & Descalle, M
Object Type: Report
System: The UNT Digital Library
Diagnostic Systems Approach to Watershed Management (open access)

Diagnostic Systems Approach to Watershed Management

The water quality of discharge from the surface water system is ultimately dictated by land use and climate within the watershed. Water quality has vastly improved from point source reduction measures, yet, non-point source pollutants continue to rise. 30 to 40% of rivers still do not meet water quality standards for reasons that include impact from urban storm water runoff, agricultural and livestock runoff, and loss of wetlands. Regulating non-point source pollutants proves to be difficult since specific dischargers are difficult to identify. However, parameters such as dissolved organic carbon (DOC) limit the amounts of chlorination due to simultaneous disinfection by-product formation. The concept of watershed management has gained much ground over the years as a means to resolve non-point source problems. Under this management scheme stakeholders in a watershed collectively agree to the nature and extent of non-point sources, determine water quality causes using sound scientific approaches, and together develop and implement a corrective plan. However, the ''science'' of watershed management currently has several shortcomings according to a recent National Research Council report. The scientific component of watershed management depends on acquiring knowledge that links water quality sources with geographic regions. However, there is an observational gap in this …
Date: February 23, 2001
Creator: Davisson, M L
Object Type: Report
System: The UNT Digital Library
RCRA Assessment Plan for Single-Shell Tank Waste Management Area T at the Hanford Site (open access)

RCRA Assessment Plan for Single-Shell Tank Waste Management Area T at the Hanford Site

A groundwater quality assessment plan was prepared to investigate the rate and extent of aquifer contamination beneath Waste Management Area T at the Hanford Site in Washington State. This plan is an update of a draft plan issued in January 1999, which guided work performed in fiscal year 2000.
Date: February 23, 2001
Creator: Hodges, Floyd N. & Chou, Charissa J.
Object Type: Report
System: The UNT Digital Library
Charge-state distribution and Doppler effect in an expanding photoionized plasma (open access)

Charge-state distribution and Doppler effect in an expanding photoionized plasma

None
Date: February 23, 2004
Creator: Foord, M E; Heeter, R F; Thoe, R S; Chung, H; Liedahl, D A; Goldstein, W H et al.
Object Type: Article
System: The UNT Digital Library
Material transfer system in support of the plutonium immobilization program (open access)

Material transfer system in support of the plutonium immobilization program

The Plutonium Immobilization Project is currently undertaking formulation and process development to demonstrate the immobilization of surplus plutonium in a titanate-based ceramic. These ceramic forms will be encapsulated within canisters containing high level waste glass for geologic disposal. Process development work is being conducted with sub-scale, process prototypic equipment. Final validation of the process will be done using actual plutonium material and functionally prototypic equipment within a glovebox. Due to the radioactive nature of the material, remote material handling is necessary to reduce the radiation exposure to the operators. A remote operated Material Transfer System to interface with process equipment has been developed.
Date: February 23, 2000
Creator: Pak, D
Object Type: Article
System: The UNT Digital Library
The use of magnetron arrays for depositing large-area oxide coatings (open access)

The use of magnetron arrays for depositing large-area oxide coatings

The application of coatings over large areas can be approached through the use of large deposition sources. A versatile alternative, e.g. to long rectangular magnetrons, are linear arrays of circular planar magnetrons to process coatings over wide path lengths. They investigate the feasibility of using a linear array of 76 mm diameter magnetron sources operated in the rf mode to deposit oxide target materials across a path in excess of 0.7 m wide. Specific results are given for the case of a 2 {micro}m thick, alumina coating.
Date: February 23, 2000
Creator: Jankowski, Alan Frederic; McKernan, M. & Chesser, J.
Object Type: Article
System: The UNT Digital Library
Biogeochemical Proxies in Scleractinian Corals used to Reconstruct Ocean Circulation (open access)

Biogeochemical Proxies in Scleractinian Corals used to Reconstruct Ocean Circulation

We utilize monthly {sup 14}C data derived from coral archives in conjunction with ocean circulation models to address two questions: (1) how does the shallow circulation of the tropical Pacific vary on seasonal to decadal time scales and (2) which dynamic processes determine the mean vertical structure of the equatorial Pacific thermocline. Our results directly impact the understanding of global climate events such as the El Nino-Southern Oscillation (ENSO). To study changes in ocean circulation and water mass distribution involved in the genesis and evolution of ENSO and decadal climate variability, it is necessary to have records of climate variables several decades in length. Continuous instrumental records are limited because technology for continuous monitoring of ocean currents has only recently been available, and ships of opportunity archives such as COADS contain large spatial and temporal biases. In addition, temperature and salinity in surface waters are not conservative and thus can not be independently relied upon to trace water masses, reducing the utility of historical observations. Radiocarbon ({sup 14}C) in sea water is a quasi-conservative water mass tracer and is incorporated into coral skeletal material, thus coral {sup 14}C records can be used to reconstruct changes in shallow circulation that would …
Date: February 23, 2001
Creator: Guilderson, T. P.; Kashgarian, M. & Schrag, D. P.
Object Type: Article
System: The UNT Digital Library
New methods in plasma simulation (open access)

New methods in plasma simulation

The development of implicit methods of particle-in-cell (PIC) computer simulation in recent years, and their merger with older hybrid methods have created a new arsenal of simulation techniques for the treatment of complex practical problems in plasma physics. The new implicit hybrid codes are aimed at transitional problems that lie somewhere between the long time scale, high density regime associated with MHD modeling, and the short time scale, low density regime appropriate to PIC particle-in-cell techniques. This transitional regime arises in ICF coronal plasmas, in pulsed power plasma switches, in Z-pinches, and in foil implosions. Here, we outline how such a merger of implicit and hybrid methods has been carried out, specifically in the ANTHEM computer code, and demonstrate the utility of implicit hybrid simulation in applications. 25 refs., 5 figs.
Date: February 23, 1990
Creator: Mason, R. J.
Object Type: Article
System: The UNT Digital Library
HyperFlow Theory Manual (open access)

HyperFlow Theory Manual

This document presents the underlying theory for an unsteady computational model of the transient aerothermodynamics of a deformable vehicle entering an atmosphere at hypersonic speeds. Many unique features of the problem require unusual computational capabilities. The large accelerations associated with the vehicle's flight dynamics results in the body-fixed reference frame being non-inertial, and the governing equations must be modified to include this effect. The vehicle's structural deformations and ablation requires the inclusion of the effects of a moving solid boundary, with a nonuniform mass flux across that boundary. A computational chemistry capability must be included to treat the thermochemical nonequilibrium of the high-temperature gas dynamics, and the reactions between the ablation products and the dissociated air. The theory required to treat these phenomena are described in this report.
Date: February 23, 2004
Creator: Felker, F F
Object Type: Report
System: The UNT Digital Library
Protein Model Database (open access)

Protein Model Database

The phenomenal success of the genome sequencing projects reveals the power of completeness in revolutionizing biological science. Currently it is possible to sequence entire organisms at a time, allowing for a systemic rather than fractional view of their organization and the various genome-encoded functions. There is an international plan to move towards a similar goal in the area of protein structure. This will not be achieved by experiment alone, but rather by a combination of efforts in crystallography, NMR spectroscopy, and computational modeling. Only a small fraction of structures are expected to be identified experimentally, the remainder to be modeled. Presently there is no organized infrastructure to critically evaluate and present these data to the biological community. The goal of the Protein Model Database project is to create such infrastructure, including (1) public database of theoretically derived protein structures; (2) reliable annotation of protein model quality, (3) novel structure analysis tools, and (4) access to the highest quality modeling techniques available.
Date: February 23, 2005
Creator: Fidelis, K; Adzhubej, A; Kryshtafovych, A & Daniluk, P
Object Type: Report
System: The UNT Digital Library
Oxidation Resistance of Ru-Capped EUV Multilayers (open access)

Oxidation Resistance of Ru-Capped EUV Multilayers

Differently prepared Ru-capping layers, deposited on Mo/Si EUV multilayers, have been characterized using a suite of metrologies to establish their baseline structural, optical, and surface properties in as-deposited state. Same capping layer structures were tested for their thermal stability and oxidation resistance. Post-mortem characterization identified changes due to accelerated tests. The best performing Ru-capping layer structure was studied in detail with transmission electron microscopy to identify the grain microstructure and texture. This information is essential for modeling and performance optimization of EUVL multilayers.
Date: February 23, 2005
Creator: Bajt, S.; Dai, Z.; Nelson, E. J.; Wall, M. A.; Alameda, J.; Nguyen, N. et al.
Object Type: Article
System: The UNT Digital Library
Reconstructing Ocean Circulation using Coral (triangle)14C Time Series (open access)

Reconstructing Ocean Circulation using Coral (triangle)14C Time Series

We utilize monthly {sup 14}C data derived from coral archives in conjunction with ocean circulation models to address two questions: (1) how does the shallow circulation of the tropical Pacific vary on seasonal to decadal time scales and (2) which dynamic processes determine the mean vertical structure of the equatorial Pacific thermocline. Our results directly impact the understanding of global climate events such as the El Nino-Southern Oscillation (ENSO). To study changes in ocean circulation and water mass distribution involved in the genesis and evolution of ENSO and decadal climate variability, it is necessary to have records of climate variables several decades in length. Continuous instrumental records are limited because technology for continuous monitoring of ocean currents (e.g. satellites and moored arrays) has only recently been available, and ships of opportunity archives such as COADS contain large spatial and temporal biases. In addition, temperature and salinity in surface waters are not conservative and thus can not be independently relied upon to trace water masses, reducing the utility of historical observations. Radiocarbon in sea water is a quasi-conservative water mass tracer and is incorporated into coral skeletal material, thus coral {sup 14}C records can be used to reconstruct changes in shallow …
Date: February 23, 2001
Creator: Kashgarian, M. & Guilderson, T. P.
Object Type: Report
System: The UNT Digital Library
Computation of Hypersonic Flow about Maneuvering Vehicles with Changing Shapes (open access)

Computation of Hypersonic Flow about Maneuvering Vehicles with Changing Shapes

Vehicles moving at hypersonic speeds have great importance to the National Security. Ballistic missile re-entry vehicles (RV's) travel at hypersonic speeds, as do missile defense intercept vehicles. Despite the importance of the problem, no computational analysis method is available to predict the aerodynamic environment of maneuvering hypersonic vehicles, and no analysis is available to predict the transient effects of their shape changes. The present state-of-the-art for hypersonic flow calculations typically still considers steady flow about fixed shapes. Additionally, with present computational methods, it is not possible to compute the entire transient structural and thermal loads for a re-entry vehicle. The objective of this research is to provide the required theoretical development and a computational analysis tool for calculating the hypersonic flow about maneuvering, deforming RV's. This key enabling technology will allow the development of a complete multi-mechanics simulation of the entire RV flight sequence, including important transient effects such as complex flight dynamics. This will allow the computation of the as-delivered state of the payload in both normal and unusual operational environments. This new analysis capability could also provide the ability to predict the nonlinear, transient behavior of endo-atmospheric missile interceptor vehicles to the input of advanced control systems. Due …
Date: February 23, 2004
Creator: Ferencz, R M; Felker, F F & Castillo, V M
Object Type: Report
System: The UNT Digital Library
NIF Optical Materials and Fabrication Technologies: An Overview (open access)

NIF Optical Materials and Fabrication Technologies: An Overview

The high-energy/high-power section of the NIF laser system contains 7360 meter-scale optics. Advanced optical materials and fabrication technologies needed to manufacture the NIF optics have been developed and put into production at key vendor sites. Production rates are up to 20 times faster and per-optic costs 5 times lower than could be achieved prior to the NIF. In addition, the optics manufactured for NIF are better than specification giving laser performance better than the design. A suite of custom metrology tools have been designed, built and installed at the vendor sites to verify compliance with NIF optical specifications. A brief description of the NIF optical wavefront specifications for the glass and crystal optics is presented. The wavefront specifications span a continuous range of spatial scale-lengths from 10 {micro}m to 0.5 m (full aperture). We have continued our multi-year research effort to improve the lifetime (i.e. damage resistance) of bulk optical materials, finished optical surfaces and multi-layer dielectric coatings. New methods for post-processing the completed optic to improve the damage resistance have been developed and made operational. This includes laser conditioning of coatings, glass surfaces and bulk KDP and DKDP and well as raster and full aperture defect mapping systems. Research …
Date: February 23, 2004
Creator: Campbell, J. H.; Hawley-Fedder, R. A.; Stolz, C. J.; Menapace, J. A.; Borden, M. R.; Whitman, P. K. et al.
Object Type: Article
System: The UNT Digital Library
Diffusion and Precipitation on Inert Gases in Metals. Technical Progress Report for the Period June 31, 1969 Through February 23, 1970 (open access)

Diffusion and Precipitation on Inert Gases in Metals. Technical Progress Report for the Period June 31, 1969 Through February 23, 1970

This report addresses the diffusion and precipitation of inert gases in metals.
Date: February 23, 1970
Creator: Cost, James R.
Object Type: Report
System: The UNT Digital Library
A Discussion of SY-101 Crust Gas Retention and Release Mechanisms (open access)

A Discussion of SY-101 Crust Gas Retention and Release Mechanisms

A Discussion of SY-101 Crust Gas Retention and Release Mechanisms
Date: February 23, 1999
Creator: Rassat, Scot D.; Gauglitz, Phillip A.; Caley, Stacie M.; Mahoney, Lenna A. & Mendoza, Donaldo P.
Object Type: Report
System: The UNT Digital Library
Towards a theory of quark and lepton masses (open access)

Towards a theory of quark and lepton masses

Has any progress been made on understanding and predicting the 13 parameters which describe the observed masses and mixing angles of the quarks and leptons? Arguments are given in favor of pursuing schemes in which grand unified and family symmetries provide many relations among these 13 parameters. A sequence of simple assumptions leads to a supersymmetric SO(10) theory with 8 predictions: tan {beta}, M{sub t}, V{sub cb}, M{sub s},M{sub s}/M{sub d}, M{sub u}/M{sub d}, V{sub ub} and the amount of CP violation J. These predictions are presented, together with experiments which will test them.
Date: February 23, 1993
Creator: Hall, L. J.
Object Type: Article
System: The UNT Digital Library
Industrial pulverized coal low NO{sub x} burner. Phase 1 (open access)

Industrial pulverized coal low NO{sub x} burner. Phase 1

The objective of Phase 1 of this program is to develop a novel low NO{sub x} pulverized coal burner, which offers near-term commercialization potential, uses preheated combustion air of up to 1000{degree}F, and which can be applied to high-temperature industrial heating furnaces, chemical process furnaces, fired heaters, and boilers. In the low NO{sub x} coal burner concept, the flue gas is recycled to the burner by jet pump action provided by the momentum of the primary air flow. The recycled flue gas is used to convey the pulverized coal to the jet pump where mixing with the primary air takes place. Ignition occurs downstream of the jet mixing section. The recycled flue gas is at high temperature. When the pulverized coal is entrained, it is heated by conduction from the flue gas. The coal is pyrolyzed to a large extent before being mixed with the primary air. These pyrolysis products are the source of energy for the downstream flame. In this process, the fuel nitrogen associated with pyrolysis products can be converted to molecular nitrogen in the pyrolysis flame if the oxygen is held to substoichiometric concentrations based upon the burning species (pyrolysis products and some char). Pyrolysis products combustion …
Date: February 23, 1993
Creator: unknown
Object Type: Report
System: The UNT Digital Library