Temperature and Emissivity of a Shocked Surface: A First Experiment (open access)

Temperature and Emissivity of a Shocked Surface: A First Experiment

We have conducted an experiment in which the temperature and the wavelength dependent emissivity of a shocked surface has been measured. In the past, only the thermal emission from the shocked surface has been measured. The lack of knowledge of the emissivity as a function of wavelength leads to uncertainty in converting the measured emission spectrum into a surface temperature. We have developed a technique by which we are able to calculate both the emissivity of the shocked surface over a range of relevant wavelengths and the temperature of the surface. We use a multi-channel spectrometer in combination with a pulsed light source having a known spectrum of infrared radiation. Two separate techniques using a pulse of reflected radiation are employed and described. Both give the same result: An initially polished molybdenum surface that is shocked and partially released has a temperature of 1040 degrees Kelvin and a wavelength ({lambda}) dependent emissivity of 0.16 ({lambda} = 1.2 {micro}m), 0.10 ({lambda} = 1.6 {micro}m), and 0.20 ({lambda} = 2.3 {micro}m).
Date: February 4, 2002
Creator: Poulsen, P & Hare, D E
Object Type: Report
System: The UNT Digital Library
Development of an "Isotopic" Pulser (open access)

Development of an "Isotopic" Pulser

We have developed a pulser that is able to generate a simulated signal from a high-purity germanium (HPGe) detector for various plutonium isotopes. In this paper we describe the development of an ''isotopics'' pulser for the simulation of signals that are produced by an HPGe detector. The present pulser generates the waveforms that are produced by an HPGe detector both before and after the preamplifier. These signals have been input into a normal MCA and the result closely simulates a genuine pulse-height distribution.
Date: June 4, 2002
Creator: Luke, S. J.; Schmid, G.; Beckedahl, D.; Pohl, B. & White, G.
Object Type: Article
System: The UNT Digital Library
Acoustic Filtration, Fractionation, and Mixing in Microfluidic Systems (open access)

Acoustic Filtration, Fractionation, and Mixing in Microfluidic Systems

This project is concerned with the research and development of a technique to manipulate small particles using acoustic energy coupled into a fluid filled plastic or glass sample chamber. These resulting miniaturized systems combine high functionality with an inexpensive, disposable sample chamber. Our approach to this problem is based on a combination of sophisticated modeling tools in conjunction with laboratory experiments. The design methodology is summarized in Figure 1. The process begins by investigating a wide range of device parameters using a one-dimensional analytical approximation. The results of these initial parameter studies are incorporated into a sophisticated three-dimensional multi-physics finite element code. From these simulations the optimized designs are prototyped and experimentally tested. The results of the experimental observations are then used to improve analytical approximations and the process is repeated as necessary.
Date: February 4, 2002
Creator: Wang, A & Fisher, K
Object Type: Report
System: The UNT Digital Library
Coexistence of antiferromagnetic order and superconductivity in CeRh[sub 1[minus]x]M[sub x]In[sub 5](M=Ir and Co) (open access)

Coexistence of antiferromagnetic order and superconductivity in CeRh[sub 1[minus]x]M[sub x]In[sub 5](M=Ir and Co)

We report a systematic neutron diffraction study on the coexistence of long-range magnetic order and superconductivity in heavy fermion compounds CeRhl-,M,Ins (M=Ir,Co). In addition to the incommensurate antiferromagnetic component in pure CeRhIn5, new type of antiferromagnetic component is found to concur with appearance of superconductivity in the Ir and Co alloy series. There is no detectable effect of the superconducting transition on magnetic order parameters. We compare those results with similar studies we performed on CeRhIn:, under pressure. We also discuss possible theoretical scenarios.
Date: December 4, 2002
Creator: Llobet-Megias, A. (Anna); Christianson, A. D. (Andrew D.); Bao, W. (Wei); Gardner, J. S.; Pagliuso, P. J. (Pascoal J.); Moreno, N. O. et al.
Object Type: Article
System: The UNT Digital Library
Implications of the KONVERGENCE Model for Difficult Cleanup Decisions (open access)

Implications of the KONVERGENCE Model for Difficult Cleanup Decisions

Abstract—Some cleanup decisions, such as cleanup of intractable contaminated sites or disposal of spent nuclear fuel, have proven difficult to make. Such decisions face high resistance to agreement from stakeholders possibly because they do not trust the decision makers, view the consequences of being wrong as too high, etc. Our project’s goal is to improve sciencebased cleanup decision-making. This includes diagnosing intractable situations, as a step to identifying a path toward sustainable solutions. Companion papers describe the underlying philosophy of the KONVERGENCE Model for Sustainable Decisions,1 and the overall framework and process steps.2 Where knowledge, values, and resources converge (the K, V, and R in KONVERGENCE), you will find a sustainable decision – a decision that works over time. For intractable cases, serious consideration of the adaptable class of alternatives is warranted – if properly implemented and packaged.
Date: August 4, 2002
Creator: Piet, Steven James; Dakins, Maxine Ellen; Gibson, Patrick Lavern; Joe, Jeffrey Clark; Kerr, Thomas A & Nitschke, Robert Leon
Object Type: Article
System: The UNT Digital Library
Reactive Fluid Flow and Applications to Diagenesis, Mineral Deposits, and Crustal Rocks (open access)

Reactive Fluid Flow and Applications to Diagenesis, Mineral Deposits, and Crustal Rocks

The objective is to initiate new: modeling of coupled fluid flow and chemical reactions of geologic environments; experimental and theoretical studies of water-rock reactions; collection and interpretation of stable isotopic and geochemical field data at many spatial scales of systems involving fluid flow and reaction in environments ranging from soils to metamorphic rocks. Theoretical modeling of coupled fluid flow and chemical reactions, involving kinetics, has been employed to understand the differences between equilibrium, steady-state, and non-steady-state behavior of the chemical evolution of open fluid-rock systems. The numerical codes developed in this project treat multi-component, finite-rate reactions combined with advective and dispersive transport in multi-dimensions. The codes incorporate heat, mass, and isotopic transfer in both porous and fractured media. Experimental work has obtained the kinetic rate laws of pertinent silicate-water reactions and the rates of Sr release during chemical weathering. Ab-initio quantum mechanical techniques have been applied to obtain the kinetics and mechanisms of silicate surface reactions and isotopic exchange between water and dissolved species. Geochemical field-based studies were carried out on the Wepawaug metamorphic schist, on the Irish base-metal sediment-hosted ore system, in the Dalradian metamorphic complex in Scotland, and on weathering in the Columbia River flood basalts. The geochemical …
Date: November 4, 2002
Creator: Rye, Danny M. & Bolton, Edward W.
Object Type: Report
System: The UNT Digital Library
Relative permeabilities for strictly hyperbolic models of three-phase flow in porous media (open access)

Relative permeabilities for strictly hyperbolic models of three-phase flow in porous media

None
Date: September 4, 2002
Creator: Juanes, Ruben & Patzek, Tadeusz W.
Object Type: Article
System: The UNT Digital Library
Construction of block-coil high-field model dipoles for future hadron colliders (open access)

Construction of block-coil high-field model dipoles for future hadron colliders

A family of high-field dipoles is being developed at Texas A&M University, as part of the program to improve the cost-effectiveness of superconducting magnet technology for future hadron colliders. The TAMU technology employs stress management, flux-plate control of persistent-current multipoles, conductor optimization using mixed-strand cable, and metal-filled bladders to provide pre-load and surface compliance. Construction details and status of the latest model dipole will be presented.
Date: August 4, 2002
Creator: Blackburn, Raymond; Elliott, Tim; Henchel, William; McInturff, Al; McIntyre, Peter & Sattarov, Akhdior
Object Type: Article
System: The UNT Digital Library
Flow of two-dimensional liquid metal jet in a strong magnetic field. (open access)

Flow of two-dimensional liquid metal jet in a strong magnetic field.

Steady, two-dimensional flow of a liquid metal jet pouring vertically down from a nozzle in the presence of crossed magnetic and electric fields has been investigated. The magnetic field is supposed to have a single component transverse to the flow. An asymptotic, high Hartmann number model has been used to study a combined effect of surface tension, nonuniform magnetic field, gravity and inertia. Relations have been obtained for a jet issuing from a duct, pouring into a draining duct, pouring from one duct into another, and that in a liquid bridge. The results show that the jet becomes thicker if the field increases along the flow and thinner if it decreases. It has also been shown that for gradually varying fields characteristic for the divertor region of both C-MOD and NSTX tokamaks, inertial effects are negligible for N > 10, where N is the interaction parameter. Thus, provided the jet remains stable, the inertialess flow model is expected to give good results even for relatively low magnetic fields and high jet velocity. Surface tension plays a crucial role in shaping the jet profile at the nozzle. Partial flooding of the nozzle walls is predicted. Finally, proposals have been made to …
Date: November 4, 2002
Creator: Reed, C. B. & Molokov, S.
Object Type: Report
System: The UNT Digital Library
A matrix lower bound (open access)

A matrix lower bound

A matrix lower bound is defined that generalizes ideas apparently due to S. Banach and J. von Neumann. The matrix lower bound has a natural interpretation in functional analysis, and it satisfies many of the properties that von Neumann stated for it in a restricted case. Applications for the matrix lower bound are demonstrated in several areas. In linear algebra, the matrix lower bound of a full rank matrix equals the distance to the set of rank-deficient matrices. In numerical analysis, the ratio of the matrix norm to the matrix lower bound is a condition number for all consistent systems of linear equations. In optimization theory, the matrix lower bound suggests an identity for a class of min-max problems. In real analysis, a recursive construction that depends on the matrix lower bound shows that the level sets of continuously differential functions lie asymptotically near those of their tangents.
Date: February 4, 2002
Creator: Grcar, Joseph F.
Object Type: Report
System: The UNT Digital Library
Dike Propagation Near Drifts (open access)

Dike Propagation Near Drifts

The purpose of this Analysis and Model Report (AMR) supporting the Site Recommendation/License Application (SR/LA) for the Yucca Mountain Project is the development of elementary analyses of the interactions of a hypothetical dike with a repository drift (i.e., tunnel) and with the drift contents at the potential Yucca Mountain repository. This effort is intended to support the analysis of disruptive events for Total System Performance Assessment (TSPA). This AMR supports the Process Model Report (PMR) on disruptive events (CRWMS M&O 2000a). This purpose is documented in the development plan (DP) ''Coordinate Modeling of Dike Propagation Near Drifts Consequences for TSPA-SR/LA'' (CRWMS M&O 2000b). Evaluation of that Development Plan and the work to be conducted to prepare Interim Change Notice (ICN) 1 of this report, which now includes the design option of ''Open'' drifts, indicated that no revision to that DP was needed. These analyses are intended to provide reasonable bounds for a number of expected effects: (1) Temperature changes to the waste package from exposure to magma; (2) The gas flow available to degrade waste containers during the intrusion; (3) Movement of the waste package as it is displaced by the gas, pyroclasts and magma from the intruding dike (the …
Date: March 4, 2002
Creator: unknown
Object Type: Report
System: The UNT Digital Library
AN RFQ DESIGNED TO ACCEPT BEAM FROM A WEAK FOCUSING LEBT (open access)

AN RFQ DESIGNED TO ACCEPT BEAM FROM A WEAK FOCUSING LEBT

None
Date: June 4, 2002
Creator: YOUNG, LLOYD M.
Object Type: Article
System: The UNT Digital Library
Special population planner (SPP) emergency planning for people who need special help. (open access)

Special population planner (SPP) emergency planning for people who need special help.

None
Date: June 4, 2002
Creator: Tanzman, E.
Object Type: Article
System: The UNT Digital Library
Atomic Scale Characterization of Oxygen Vacancy Dynamics by in Situ Reduction and Analytical Atomic Resolution Stem. (open access)

Atomic Scale Characterization of Oxygen Vacancy Dynamics by in Situ Reduction and Analytical Atomic Resolution Stem.

In this study, we present nano-scale investigations of point defect dynamics in perovskite oxides by correlated atomic resolution high angle annular dark field imaging (HAADF) and electron energy loss spectroscopy (EELS). The point defect dynamics and interactions during in-situ reduction in the microscope column are analyzed. In particular, oxygen vacancy creation, diffusion and clustering are studied, as oxygen vacancies comprise the majority of the point defects present in these perovskite oxide systems [1]. The results have been acquired using the JEOL2010F, a STEM/TEM, equipped with a 200 keV field emission gun, a high angle annular dark field detector and a post column Gatan imaging filter (GIF). The combination of the Z-contrast and EELS techniques [2] allows us to obtain direct images (spatial resolution of 2 {angstrom}) of the atomic structure and to correlate this information with the atomically resolved EELS information (3s acquisition time, 1.2 eV energy resolution). In-situ heating of the material is performed in a Gatan double tilt holder with a temperature range of 300 K-773 K at an oxygen partial pressure of P{sub O{sub 2}} = 5 * 10{sup -8} Pa.
Date: August 4, 2002
Creator: Klie, R. F.; Browning, N. D. & Zhu, Y.
Object Type: Article
System: The UNT Digital Library
NEXT GENERATION IR MAGNETS FOR HADRON COLLIDERS. (open access)

NEXT GENERATION IR MAGNETS FOR HADRON COLLIDERS.

Brookhaven National Laboratory (BNL) is developing ''React & Wind'' designs and technology for building long high field accelerator magnets. This paper presents the R&D program for interaction region (IR) magnets made with ''Rutherford'' cable for the luminosity upgrade of the Large Hadron Collider (LHC). This paper will introduce a few new end design concepts that make the bend radius of the cable in the end independent of the coil aperture. These designs are suitable for building magnets with ''React & Wind'' technology.
Date: August 4, 2002
Creator: Gupta, R.; Anerella, M.; Cozzolino, J.; Escallier, J.; Ganetis, G.; Harrison, M. et al.
Object Type: Article
System: The UNT Digital Library
Ammonia Emission Projections for DWPF Recycle During Macrobatch 3 Campaign (open access)

Ammonia Emission Projections for DWPF Recycle During Macrobatch 3 Campaign

The expected concentration of ammonia in the DWPF liquid recycle during the Macrobatch 3 campaign was estimated using the CPES model. The generation of hydrogen and ammonia during the SRAT/SME cycles was modeled using the same chemistry bases that have been used in all previous CPES model runs made since 1993. In this study, however, the current model basis for calculating the total ammonia production during a coupled operation was reformulated into a more useful form equally applicable to a sludge-only operation as well.
Date: February 4, 2002
Creator: Choi, A.S.
Object Type: Report
System: The UNT Digital Library
PHASE RETRIEVAL, SYMMETRIZATION RULE AND TRANSPORT OF INTENSITY EQUATION IN APPLICATION TO INDUCTION MAPPING OF MAGNETIC MATERIALS. (open access)

PHASE RETRIEVAL, SYMMETRIZATION RULE AND TRANSPORT OF INTENSITY EQUATION IN APPLICATION TO INDUCTION MAPPING OF MAGNETIC MATERIALS.

Recent progress in the field of noninterferometric phase retrieval brings the ordinary Fresnel microscopy to a new quantitative level, suitable for recovering both the amplitude and phase of the object, based on image intensity measurements of the object. We show that this is sufficient for in-plane component mapping of magnetic induction for small magnetic elements with known geometry ranging from micro- to few nanometers size. In present paper we re-examine some conservation principles used for the transport-of-intensity (TIE) equation derived by Teaque for application to phase retrieval in light and X-ray optics. In particular, we prove that the intensity conservation law should be replaced in general case with the energy-flow conservation law. This law describes the amplitude-phase balance of the partially coherent beam on its propagation along the optical path, valid both for light and electron optics. This substitution has at least two important fundamental consequences.
Date: August 4, 2002
Creator: Volkov, V. V. & Zhu, Y.
Object Type: Article
System: The UNT Digital Library
Simulation of chamber transport for heavy-ion fusion (open access)

Simulation of chamber transport for heavy-ion fusion

Beams for heavy-ion fusion (HIF) are expected to require substantial neutralization in a target chamber. Present targets call for higher beam currents and smaller focal spots than most earlier designs, leading to high space-charge fields. Collisional stripping by the background gas expected in the chamber further increases the beam charge. Simulations with no electron sources other than beam stripping and background-gas ionization show an acceptable focal spot only for high ion energies or for currents far below the values assumed in recent HIF power-plant scenarios. Much recent research has, therefore, focused on beam neutralization by electron sources that were neglected in earlier simulations, including emission from walls and the target, photoionization by radiation from the target, and pre-neutralization by a plasma generated along the beam path. The simulations summarized here indicate that these effects can significantly reduce the beam focal-spot size.
Date: October 4, 2002
Creator: Sharp, W. M.; Callahan, D. A.; Tabak, M. A.; Yu, S. S.; Peterson, P. F.; Rose, D. V. et al.
Object Type: Article
System: The UNT Digital Library
Results of the Comparison Analyses of the Two Tank 40H Sludge Batch 2 Qualification Samples (open access)

Results of the Comparison Analyses of the Two Tank 40H Sludge Batch 2 Qualification Samples

Two sets of six samples each of Sludge Batch 2 material were pulled from Tank 40H after completion of the transfer of the contents of Tank 8F to Tank 40H. At the request of Defense Waste Processing Facility (DWPF) personnel, these two sets of samples were analyzed to verify that there were no significant differences between the two sets due to differences in slurry pump operation time prior to pulling the samples. The results of those analyses indicate that the two samples are within 1.2 percent of each other for weight percent total solids in the slurry and weight percent dissolved solids in the supernate. Elemental analyses of the total slurry by Inductively Coupled Plasma-Mass Spectrometry (ICP-ES) gave differences of less than 2 percent. Analyses of selected fission product isotopes and actinides produced differences of generally less than 4 percent, though a couple of isotopes showed differences of up to 6 percent. With the exception of a few of the elemental analyses, whose differences were less than 1.5 percent, and Cs-137, whose concentration difference between the two samples was found to be about 3 percent, none of these differences was found to be statistically significant. This differences were compared to …
Date: February 4, 2002
Creator: Swingle, R.F.
Object Type: Report
System: The UNT Digital Library
NERSC 'Visualization Greenbook' Future visualization needs of the DOE computational science community hosted at NERSC (open access)

NERSC 'Visualization Greenbook' Future visualization needs of the DOE computational science community hosted at NERSC

This report presents the findings and recommendations that emerged from a one-day workshop held at Lawrence Berkeley National Laboratory (LBNL) on June 5, 2002, in conjunction with the NERSC User Group (NUG) Meeting. The motivation for this workshop was to solicit direct input from the application science community on the subject of visualization. The workshop speakers and participants included computational scientists from a cross-section of disciplines that use the NERSC facility, as well as visualization researchers from across the country. We asked the workshop contributors how they currently visualize their results, and how they would like to do visualization in the future. We were especially interested in each individual's view of how visualization tools and services could be improved in order to better meet the needs of future computational science projects. The outcome of this workshop is a set of findings and recommendations that are presented in more detail later in this report, and briefly summarized here.
Date: November 4, 2002
Creator: Hamann, Bernd; Bethel, E. Wes; Simon, Horst & Meza, Juan
Object Type: Report
System: The UNT Digital Library
The Snowmass points and slopes: Benchmarks for SUSY searches (open access)

The Snowmass points and slopes: Benchmarks for SUSY searches

The ''Snowmass Points and Slopes'' (SPS) are a set of benchmark points and parameter lines in the MSSM parameter space corresponding to different scenarios in the search for Supersymmetry at present and future experiments. This set of benchmarks was agreed upon at the 2001 ''Snowmass Workshop on the Future of Particle Physics'' as a consensus based on different existing proposals.
Date: March 4, 2002
Creator: al., M. Battaglia et
Object Type: Article
System: The UNT Digital Library
What futurecar MPG levels and technology will be necessary? (open access)

What futurecar MPG levels and technology will be necessary?

The potential peaking of world conventional oil production and the possible imperative to reduce carbon emissions will put great pressure on vehicle manufacturers to produce more efficient vehicles, on vehicle buyers to seek them out in the marketplace, and on energy suppliers to develop new fuels and delivery systems. Four cases for stabilizing or reducing light vehicle fuel use, oil use, and/or carbon emissions over the next 50 years are presented. Case 1--Improve mpg so that the fuel use in 2020 is stabilized for the next 30 years. Case 2--Improve mpg so that by 2030 the fuel use is reduced to the 2000 level and is reduced further in subsequent years. Case 3--Case 1 plus 50% ethanol use and 50% low-carbon fuel cell vehicles by 2050. Case 4--Case 2 plus 50% ethanol use and 50% low-carbon fuel cell vehicles by 2050. The mpg targets for new cars and light trucks require that significant advances be made in developing cost-effective and very efficient vehicle technologies. With the use of alternative fuels that are low in carbon, oil use and carbon emissions can be reduced even further.
Date: March 4, 2002
Creator: Patterson, P.; Steiner, E. & Singh, M.
Object Type: Article
System: The UNT Digital Library
ERSM - A systems-based approach to emergency response and preparedness. (open access)

ERSM - A systems-based approach to emergency response and preparedness.

None
Date: June 4, 2002
Creator: Mitrani, J. E. & Hewett, P. H.
Object Type: Article
System: The UNT Digital Library
Magnet Engineering and Test Results of the High Field Magnet R and D Program at Bnl. (open access)

Magnet Engineering and Test Results of the High Field Magnet R and D Program at Bnl.

The Superconducting Magnet Division at Brookhaven National Laboratory (BNL) has been carrying out design, engineering, and technology development of high performance magnets for future accelerators. High Temperature Superconductors (HTS) play a major role in the BNL vision of a few high performance interaction region (IR) magnets that would be placed in a machine about ten years from now. This paper presents the engineering design of a ''react and wind'' Nb{sub 3}Sn magnet that will provide a 12 Tesla background field on HTS coils. In addition, the coil production tooling as well as the most recent 10-turn R&D coil test results will be discussed.
Date: August 4, 2002
Creator: Cozzolino, J.; Anerella, M.; Escallier, J.; Ganetis, G.; Ghosh, A.; Gupta, R. et al.
Object Type: Article
System: The UNT Digital Library