States

Three methods to measure RH bond energies (open access)

Three methods to measure RH bond energies

In this paper the authors compare and contrast three powerful methods for experimentally measuring bond energies in polyatomic molecules. The methods are: radical kinetics; gas phase acidity cycles; and photoionization mass spectroscopy. The knowledge of the values of bond energies are a basic piece of information to a chemist. Chemical reactions involve the making and breaking of chemical bonds. It has been shown that comparable bonds in polyatomic molecules, compared to the same bonds in radicals, can be significantly different. These bond energies can be measured in terms of bond dissociation energies.
Date: March 21, 1993
Creator: Berkowitz, J.; Ellison, G. B. & Gutman, D.
Object Type: Report
System: The UNT Digital Library
Survey of Recent Developments in Solvent Extraction With Tributyl Phosphate (open access)

Survey of Recent Developments in Solvent Extraction With Tributyl Phosphate

Tributyl phosphate can be used for extraction in processing all current power reactor fuels. Nitric acid is the only salting agent required. Typical flowsheets are presented. In aluminum nitrate systems which are more than 0.1 M acid deficient, the uranium distribution coefficient is a function of pH and independent of aluminum concentration; the coefficient remains constant at one in fluoride systems when the nitrate to fluoride ratio is approximates 3.5. Many objectionable properties of degraded diluents are ascribed to nitroparaffins. Aliphatic diluents with the least branching are the most stable to nitration. The nitration stability of aromatic diluents varies with structure, e.g., stabilities of diethylbenzenes decrease as meta >> ortho > para. Solvent purification by flash distillation appears superior to other methods. The stability of Amsco 125-82 was permanently improved by treatment with sulfuric acid. The radiation stability of TBP was approximates 2 times higher in an aromatic diluent than in Amsco 125-82. The G decomposition value for 1 M TBP in Amsco alone was approximates 0.9; whereas in 1 to 3 M HNO/sub 3/ it was 1 to 5 and G (--HNO/sub 3/ org phase) was 3 to 20. Variation of uranium--thorium separation factors with structure of some neutral …
Date: March 21, 1963
Creator: Blanco, R. E.; Blake, C. A., Jr.; Davis, W. Jr. & Rainey, R.H.
Object Type: Report
System: The UNT Digital Library
Advanced Binary Geothermal Power Plancts Working Fluid Property Determination and Heat Exchanger Design (open access)

Advanced Binary Geothermal Power Plancts Working Fluid Property Determination and Heat Exchanger Design

The performance of binary geothermal power plants can be improved through the proper choice of a working fluid, and optimization of component designs and operating conditions. This paper reviews the investigations at the Idaho National Engineering Laboratory (INEL) which are examining binary cycle performance improvements: for moderate temperature (350 to 400 F) resources with emphasis on how the improvements may be integrated into design of binary cycles. These investigations are examining performance improvements resulting from the supercritical vaporization of mixed hydrocarbon working fluids and achieving countercurrent integral condensation with these fluids, as well as the modification of the turbine inlet state points to achieve supersaturated turbine vapor expansions. For resources where the brine outlet temperature is restricted, the use of turbine exhaust recuperators is examined. The baseline plant used to determine improvements in plant performance (characterized by the increase in the net brine effectiveness, watt-hours per pound of brine) in these studies operates at conditions similar to the 45 MW Heber binary plant. Through the selection of the optimum working fluids and operating conditions, achieving countercurrent integral condensation, and allowing supersaturated vapor expansions in the turbine, the performance of the binary cycle (the net brine effectiveness) can be improved by …
Date: March 21, 1989
Creator: Bliem, C.J. & Mines, G.L.
Object Type: Article
System: The UNT Digital Library
Partial Acceptance for Beneficial Use (ABU) for the Type 4 In Situ Vapor Sampler (ISVS) Carts (open access)

Partial Acceptance for Beneficial Use (ABU) for the Type 4 In Situ Vapor Sampler (ISVS) Carts

This document provides the ''Partial'' Acceptance for Beneficial Use (ABU), for the Type 4 in-situ vapor sampler system (ISVS). This document is generated to support the completion of equipment modifications and engineering documentation for the ISVS system that is used for sampling gaseous vapors in the Hanford single shell radioactive waste storage tanks. The ABU is used to document the items required for transferring the ISVS system to operations for field use. This document is generated following Characterization Engineering Desk Instruction DI-CE-004-001.
Date: March 21, 2000
Creator: Boger, R. M.
Object Type: Report
System: The UNT Digital Library
Nanosecond Ultrasonics to Study Phase Transitions in Solid and Liquid Systems at High Pressure and Temperature (open access)

Nanosecond Ultrasonics to Study Phase Transitions in Solid and Liquid Systems at High Pressure and Temperature

This report describes the development of a high-frequency ultrasonic measurement capability for application to the study of phase transitions at elevated pressure and temperature. We combined expertise in various aspects of static high-pressure technique with recent advances in wave propagation modeling, ultrasonic transducer development, electronic methods and broadband instrumentation to accomplish the goals of this project. The transduction and electronic systems have a demonstrated bandwidth of 400 MHz, allowing investigations of phenomena with characteristic times as short as 2.5 nS. A compact, pneumatically driven moissanite anvil cell was developed and constructed for this project. This device generates a high-pressure environment for mm dimension samples to pressures of 3 GPa. Ultrasonic measurements were conducted in the moissanite cell, an LLNL multi-anvil device and in a modified piston cylinder device. Measurements for water, and elemental tantalum, tin and cerium demonstrate the success of the methods. The {gamma}-{alpha} phase transition in cerium was clearly detected at {approx}0.7 GPa with 75 MHz longitudinal waves. These results have direct application to important problems in LLNL programs, as well as seismology and planetary science.
Date: March 21, 2007
Creator: Bonner, B P; Berge, P A; Carlson, S C; Farber, D L & Akella, J
Object Type: Report
System: The UNT Digital Library
Health - Physics Monthly Information Report. February 1-28, 1951 (open access)

Health - Physics Monthly Information Report. February 1-28, 1951

None
Date: March 21, 1951
Creator: Boozer, A. H.
Object Type: Report
System: The UNT Digital Library
2006 Sensory Transduction in Microorganisms Gordon Conference - January 22-27 (open access)

2006 Sensory Transduction in Microorganisms Gordon Conference - January 22-27

This Report is Description of Sensory Transduction in Microorganisms at Gordon Conference.
Date: March 21, 2007
Creator: Borkovich, Katherine
Object Type: Article
System: The UNT Digital Library
METHODS FOR THE ANALYSIS OF BERYLLIUM CARBIDE (open access)

METHODS FOR THE ANALYSIS OF BERYLLIUM CARBIDE

Analytical methods are given for determining the composition and impurities of beryllium carbide. A summary of the experimental work leading to these procedures and supporting data are also presented. Analytical procedures for the determination of free and combined carbon, moisture, nitrogen, beryllium oxide, silica, iron, total beryllium, and beryllium metal are outlined. Diagrams of special apparatus used are included. (auth)
Date: March 21, 1949
Creator: Bridges, W.L.; Funston, E.S. & Reed, S.A.
Object Type: Report
System: The UNT Digital Library
Flash Vacuum Pyrolysis of Lignin Model Compounds: Reaction Pathways of Aromatic Methoxy Groups (open access)

Flash Vacuum Pyrolysis of Lignin Model Compounds: Reaction Pathways of Aromatic Methoxy Groups

Currently, there is interest in utilizing lignin, a major constituent of biomass, as a renewable source of chemicals and fuels. High yields of liquid products can be obtained from the flash or fast pyrolysis of biomass, but the reaction pathways that lead to product formation are not understood. To provide insight into the primary reaction pathways under process relevant conditions, we are investigating the flash vacuum pyrolysis (FVP) of lignin model compounds at 500 C. This presentation will focus on the FVP of {beta}-ether linkages containing aromatic methoxy groups and the reaction pathways of methoxy-substituted phenoxy radicals.
Date: March 21, 1999
Creator: Britt, P. F.; Buchanan, A. C., III & Martineau, D. R.
Object Type: Article
System: The UNT Digital Library
Reservoir Modeling for Production Management (open access)

Reservoir Modeling for Production Management

For both petroleum and geothermal resources, many of the reservoirs are fracture dominated--rather than matrix-permeability controlled. For such reservoirs, a knowledge of the pressure-dependent permeability of the interconnected system of natural joints (i.e., pre-existing fractures) is critical to the efficient exploitation of the resource through proper pressure management. Our experience and that reported by others indicates that a reduction in the reservoir pressure sometimes leads to an overall reduction in production rate due to the ''pinching off'' of the joint network, rather than the anticipated increase in production rate. This effect occurs not just in the vicinity of the wellbore, where proppants are sometimes employed, but throughout much of the reservoir region. This follows from the fact that under certain circumstances, the decline in fracture permeability (or conductivity) with decreasing reservoir pressure exceeds the far-field reservoir ''drainage'' flow rate increase due to the increased pressure gradient. Further, a knowledge of the pressure-dependent joint permeability could aid in designing more appropriate secondary recovery strategies in petroleum reservoirs or reinjection procedures for geothermal reservoirs.
Date: March 21, 1989
Creator: Brown, Donald W.
Object Type: Article
System: The UNT Digital Library
LMFBR safety. 4. Review of current issues and bibliography of literature (1974--1975) (open access)

LMFBR safety. 4. Review of current issues and bibliography of literature (1974--1975)

This report discusses the current status of liquid-metal fast breeder reactor (LMFBR) development and one of the principal safety issues, a hypothetical core-disruptive accident (HCDA). Bibliographic information on worldwide LMFBRs relative to the development of the breeder reactor as a safe source of nuclear power is presented for the period 1974 through 1975. The bibliography consists of approximately 1554 abstracts covering early research and development and operating experiences leading up to the present design practices that are necessary for the licensing of breeder reactors. Key-word, author, and permuted-title indexes are included for completeness.
Date: March 21, 1977
Creator: Buchanan, J. R. & Keilholtz, G. W.
Object Type: Report
System: The UNT Digital Library
Final Scientific/Technical Report "Arc Tube Coating System for Color Consistency" (open access)

Final Scientific/Technical Report "Arc Tube Coating System for Color Consistency"

DOE has enabled the use of coating materials using low cost application methods on light sources to positively affect the output of those sources. The coatings and light source combinations have shown increased lumen output of LED fixtures (1.5%-2.0%), LED arrays (1.4%) and LED powered remote phosphor systems – Philips L-Prize lamp (0.9%). We have also demonstrated lifetime enhancements (3000 hrs vs 8000 hrs) and shifting to higher CRI (51 to 65) in metal halide high intensity discharge lamps with metal oxide coatings. The coatings on LEDs and LED products are significant as the market is moving increasingly more towards LED technology. Enhancements in LED performance are demonstrated in this work through the use of available materials and low cost application processes. EFOI used low refractive index fluoropolymers and low cost dipping processes for application of the material to surfaces related to light transmission of LEDs and LED products. Materials included Teflon AF, an amorphous fluorinated polymer and fluorinated acrylic monomers. The DOE SSL Roadmap sets goals for LED performance moving into the future. EFOI’s coating technology is a means to shift the performance curve for LEDs. This is not limited to one type of LED, but is relevant across …
Date: March 21, 2013
Creator: Buelow, Roger; Jenson, Chris & Kazenski, Keith
Object Type: Report
System: The UNT Digital Library
THE YEAR-ONE PHYSICS CAPABILITIES OF STAR. (open access)

THE YEAR-ONE PHYSICS CAPABILITIES OF STAR.

When the Relativistic Heavy Ion Collider (RHIC) at BNL begins operation in the Fall of 1999, heavy ions will be accelerated in collider mode for the first time, and a new energy regime will be entered for Heavy Ion Physics. The Solenoidal Tracker At RHIC (STAR) detector has a near 4{pi} coverage and is dedicated to taking hadronic measurements. A large volume Time Projection Chamber placed in a solenoidal magnet at 0.5T is used to track and identify the many thousands of produced particles. STAR will measure many observables simultaneously on an event-by-event basis to study signatures of a possible QGP phase transition and the space-time evolution of the collision process. The goal is to obtain a fundamental understanding of the microscopic structure of hadronic interactions, at the level of quarks and gluons, at high energy densities. This paper outlines the physics STAR intends to study during the first year of operation.
Date: March 21, 1999
Creator: CAINES,H. FOR THE STAR COLLABORATION
Object Type: Article
System: The UNT Digital Library
The Photosynthetic Cycle (open access)

The Photosynthetic Cycle

None
Date: March 21, 1955
Creator: Calvin, Melvin
Object Type: Report
System: The UNT Digital Library
Portal 6.0 Released!! (open access)

Portal 6.0 Released!!

None
Date: March 21, 2011
Creator: Cantor, Michael & Smirnova, Tatyana
Object Type: Article
System: The UNT Digital Library
CHARACTERIZATION OF UO$sub 2$ POWDERS. Quarterly Report No. 5, October 10, 1961 to January 10, 1962 (open access)

CHARACTERIZATION OF UO$sub 2$ POWDERS. Quarterly Report No. 5, October 10, 1961 to January 10, 1962

The particle size distribution of UO/sub 2/ powders gave good eorrelation with the sintered density of pellets. The method involves gravity sedimentation techniques. The green pressing step of pellet fabrication was found to affect the particle size distribution of the UO/sub 2/ powders. The magnitude of this effect is considered in characterization of the pressed powders. (J.R.D.)
Date: March 21, 1962
Creator: Carpenter, J.F.; Kuhlman, C.W. & Nelson, R.A.
Object Type: Report
System: The UNT Digital Library
Deep Borehole Measurements for Characterizing the Magma/Hydrothermal System at Long Valley Caldera, CA (open access)

Deep Borehole Measurements for Characterizing the Magma/Hydrothermal System at Long Valley Caldera, CA

The Magma Energy Program of the Geothermal Technology Division is scheduled to begin drilling a deep (6 km) exploration well in Long Valley Caldera, California in 1989. The drilling site is near the center of the caldera which is associated with numerous shallow (5-7 km) geophysical anomalies. This deep well will present an unparalleled opportunity to test and validate geophysical techniques for locating magma as well as a test of the theory that magma is still present at drillable depths within the central portion of the caldera. If, indeed, drilling indicates magma, the geothermal community will then be afforded the unique possibility of examining the coupling between magmatic and hydrothermal regimes in a major volcanic system. Goals of planned seismic experiments that involve the well include the investigation of local crustal structure down to depths of 10 km as well as the determination of mechanisms for local seismicity and deformation. Borehole electrical and electromagnetic surveys will increase the volume and depth of rock investigated by the well through consideration of the conductive structure of the hydrothermal and underlying regimes. Currently active processes involving magma injection will be studied through observation of changes in pore pressure and strain. Measurements of in …
Date: March 21, 1989
Creator: Carrrigan, Charles R.
Object Type: Article
System: The UNT Digital Library
BOUT Simulations of Edge Turbulence in the DIII-D Tokamak (open access)

BOUT Simulations of Edge Turbulence in the DIII-D Tokamak

None
Date: March 21, 2012
Creator: Cohen, B. I.; Umansky, M.; Makowski, M.; Nevins, W. M.; Boedo, J.; Rudakov, D. et al.
Object Type: Article
System: The UNT Digital Library
Ion Acceleration in Plasmas Emerging from a Helicon-heated Magnetic-mirror Device (open access)

Ion Acceleration in Plasmas Emerging from a Helicon-heated Magnetic-mirror Device

Using laser-induced fluorescence, measurements have been made of metastable argon-ion, Ar{sup +}*(3d{sup 4} f{sub 7/2}), velocity distributions on the major axis of an axisymmetric magnetic-mirror device whose plasma is sustained by helicon wave absorption. Within the mirror, these ions have sub-eV temperature and, at most, a subthermal axial drift. In the region outside the mirror coils, conditions are found where these ions have a field-parallel velocity above the acoustic speed, to an axial energy of {approx}30 eV, while the field-parallel ion temperature remains low. The supersonic Ar{sup +}*(3d{sup 4} f{sub 7/2}) are accelerated to one-third of their final energy within a short region in the plasma column, {le}1 cm, and continue to accelerate over the next 5 cm. Neutral gas density strongly affects the supersonic Ar{sup +}*(3d{sup 4} f{sub 7/2}) density.
Date: March 21, 2003
Creator: Cohen, S. A.; Siefert, N. S.; Stange, S.; Boivin, R. F.; Scime, E. E. & Levinton, F. M.
Object Type: Report
System: The UNT Digital Library
Final report on the NuTeV Decay Channel (open access)

Final report on the NuTeV Decay Channel

A search for a 33.9 MeV/c weakly interacting neutral particle produced in pion decay is discussed along with other studies.
Date: March 21, 2001
Creator: Conrad, Janet M.
Object Type: Report
System: The UNT Digital Library
Required Be Capsule Strength For Room Temperature Transport (open access)

Required Be Capsule Strength For Room Temperature Transport

The purpose of this memo is to lay out the criteria for the Be capsule strength necessary for room temperature transport. Ultimately we will test full thickness capsules by sealing high pressures inside, but currently we are limited to both thinner capsules and alternative measures of capsule material strength.
Date: March 21, 2005
Creator: Cook, B
Object Type: Report
System: The UNT Digital Library
IR Extinction Coefficient Measurements of CH and CD GDP Shells (open access)

IR Extinction Coefficient Measurements of CH and CD GDP Shells

None
Date: March 21, 2003
Creator: Cook, R C & Nikroo, A
Object Type: Report
System: The UNT Digital Library
Parallelization of an Adaptive Multigrid Algorithm for Fast Solution of Finite Element Structural Problems (open access)

Parallelization of an Adaptive Multigrid Algorithm for Fast Solution of Finite Element Structural Problems

Adaptive mesh refinement selectively subdivides the elements of a coarse user supplied mesh to produce a fine mesh with reduced discretization error. Effective use of adaptive mesh refinement coupled with an a posteriori error estimator can produce a mesh that solves a problem to a given discretization error using far fewer elements than uniform refinement. A geometric multigrid solver uses increasingly finer discretizations of the same geometry to produce a very fast and numerically scalable solution to a set of linear equations. Adaptive mesh refinement is a natural method for creating the different meshes required by the multigrid solver. This paper describes the implementation of a scalable adaptive multigrid method on a distributed memory parallel computer. Results are presented that demonstrate the parallel performance of the methodology by solving a linear elastic rocket fuel deformation problem on an SGI Origin 3000. Two challenges must be met when implementing adaptive multigrid algorithms on massively parallel computing platforms. First, although the fine mesh for which the solution is desired may be large and scaled to the number of processors, the multigrid algorithm must also operate on much smaller fixed-size data sets on the coarse levels. Second, the mesh must be repartitioned as …
Date: March 21, 2002
Creator: Crane, N K; Parsons, I D & Hjelmstad, K D
Object Type: Article
System: The UNT Digital Library
CORSICA: A comprehensive simulation of toroidal magnetic-fusion devices. Final report to the LDRD Program (open access)

CORSICA: A comprehensive simulation of toroidal magnetic-fusion devices. Final report to the LDRD Program

In 1992, our group began exploring the requirements for a comprehensive simulation code for toroidal magnetic fusion experiments. There were several motivations for taking this step. First, the new machines being designed were much larger and more expensive than current experiments. Second, these new designs called for much more sophisticated control of the plasma shape and position, as well as the distributions of energy, mass, and current within the plasma. These factors alone made it clear that a comprehensive simulation capability would be an extremely valuable tool for machine design. The final motivating factor was that the national Numerical Tokamak Project (NTP) had recently received High Performance Computing and Communications (HPCC) Grand Challenge funding to model turbulent transport in tokamaks, raising the possibility that first-principles simulations of this process might be practical in the near future. We felt that the best way to capitalize on this development was to integrate the resulting turbulence simulation codes into a comprehensive simulation. Such simulations must include the effects of many microscopic length- and time-scales. In order to do a comprehensive simulation efficiently, the length- and time- scale disparities must be exploited. We proposed to do this by coupling the average or quasistatic effects …
Date: March 21, 1997
Creator: Crotinger, J. A.; LoDestro, L.; Pearlstein, L. D.; Tarditi, A.; Casper, T. A. & Hooper, E. B.
Object Type: Report
System: The UNT Digital Library