Geotomography applied at the Stripa Mine in Sweden (open access)

Geotomography applied at the Stripa Mine in Sweden

LLNL made ultrahigh-frequency (450-MHz) electromagnetic borehole-to-borehole transmissions in the Stripa Mine near Guldsmedshyttan, Sweden, in April 1979. Transmission loss measurements were made between four sets of 76-mm boreholes 30 m long, located at the end of a drift. Distances between the boreholes varied from 2 to 22 m. More than 25,000 data points were taken. A geotomograph was constructed to show the variation of attenuation between boreholes. The observed spatial variation of electromagnetic attenuation may be related to the expected stress relief created by the mine. Transmission loss measurements were also made between two converging boreholes drilled from the surface to points near the mine. Data taken at 21 MHz show a nearly uniform attenuation within this sampled region. These experiments demonstrate that geotomographic data collection/interpretation provides high-resolution images of the underground environment and can provide useful input to those charged with providing the detailed site characterizations needed for both short- and long-term monitoring of underground nuclear waste repositories.
Date: April 7, 1980
Creator: Okada, J.T.; Laine, E.F.; Lytle, R.J. & Daily,W.D.
Object Type: Report
System: The UNT Digital Library
Spatial averaging algorithms for ultrasonic inspection of austenitic stainless steel welds (open access)

Spatial averaging algorithms for ultrasonic inspection of austenitic stainless steel welds

Interpretation of ultrasonic inspection data from stainless steel welds is difficult because the signal-to-noise ratio is very low. The three main reasons for this are the granular structure of the weld, the high attenuation of stainless steel, and electronic noise. Averaging in time at the same position in space reduces electronic noise, but does not reduce ultrasonic noise from grain boundary scattering. Averaging wave-forms from different spatial positions helps reduce grain noise, but desired signals can destructively interfere if they shift in time. If the defect geometry is known, the ultrasonic waveforms can be shifted before averaging, ensuring signal reinforcement. The simplest geometry results in a linear time shift. An averaging algorithm has been developed which finds the optimum shift. This algorithm computes the averaged, or composite waveform as a function of the time shift. The optimum occurs when signals from a reflector become aligned in time, producing a large amplitude composite waveform. This algorithm works very well, but requires significant computer time and storage. This paper discusses this linear shift averaging algorithm, and considers an implementation using frequency domain techniques. Also, data from several weld defects are presented and analyzed.
Date: April 7, 1980
Creator: Horn, J. E.; Cooper, C.S. & Michaels, T.E.
Object Type: Article
System: The UNT Digital Library
Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators (open access)

Application of the Argonne Advanced Acceleration Test Facility to development for conventional accelerators

The Argonne Advanced Acceleration Test Facility is designed as a powerful tool to test ideas for very high gradient acceleration schemes based on direct beam excitation of plasmas, metal structures, dielectrics, etc. The characteristic size in these systems is )approximately) 1 cm, corresponding to frequencies )approximately) 10 GHz. The question addressed here is whether the special features of this facility have application as well to the development of components for the more conventional, lower frequency, accelerators now operating or under development. It is suggested that the usefulness of the facility for the development of conventional systems could be enhanced by a provision for longer time delay between driver and witness beam pulses. 9 refs., 2 figs.
Date: April 7, 1988
Creator: MacLachlan, J.A.
Object Type: Report
System: The UNT Digital Library
Suppression of transverse beam breakup modes in an induction accelerator by gas focusing (open access)

Suppression of transverse beam breakup modes in an induction accelerator by gas focusing

The effect of beam-generated positive ions on the beam-breakup instability in linear electron accelerators is calculated using simple models. The strongly nonlinear dependence of the ion focusing force on radius makes a complete suppression of the mode growth possible, in contrast to solenoidal focusing. The predicted gas pressures for significant stabilization of the mode growth in a machine configuration like ATA is relatively low (10/sup -5/ to 10/sup -4/ torr), even for high-Q modes.
Date: April 7, 1980
Creator: Briggs, R. J.
Object Type: Report
System: The UNT Digital Library
Role of human- and animal-sperm studies in the evaluation of male reproductive hazards (open access)

Role of human- and animal-sperm studies in the evaluation of male reproductive hazards

Human sperm tests provide a direct means of assessing chemically induced spermatogenic dysfunction in man. Available tests include sperm count, motility, morphology (seminal cytology), and Y-body analyses. Over 70 different human exposures have been monitored in various groups of exposed men. The majority of exposures studied showed a significant change from control in one or more sperm tests. When carefully controlled, the sperm morphology test is statistically the most sensitive of these human sperm tests. Several sperm tests have been developed in nonhuman mammals for the study of chemical spermatotoxins. The sperm morphology test in mice has been the most widely used. Results with this test seem to be related to germ-cell mutagenicity. In general, animal sperm tests should play an important role in the identification and assessment of potential human reproductive hazards. Exposure to spermatotoxins may lead to infertility, and more importantly, to heritable genetic damage. While there are considerable animal and human data suggesting that sperm tests may be used to detect agents causing infertility, the extent to which these tests detect heritable genetic damage remains unclear. (ERB)
Date: April 7, 1982
Creator: Wyrobek, A.J.; Gordon, L. & Watchmaker, G.
Object Type: Article
System: The UNT Digital Library
Cost effectiveness of long life incandescent lamps and energy buttons (open access)

Cost effectiveness of long life incandescent lamps and energy buttons

Long-life replacement lamps for the incandescent lamp have been evaluated with regard to their cost effectiveness. The replacements include the use of energy buttons that extend lamp life as well as an adaptive fluorescent circline lamp that will fit into existing incandescent lamp sockets. The initial, operating, and replacement costs for one million lumen hours are determined for each lamp system. It is found that the most important component lighting cost is the operating cost. Using lamps that are less efficient or devices that cause lamps to operate less efficiently are not cost-effective. The adaptive fluorescent circline lamp, even at an initial unit cost of $20.00, is the most cost-effective source of illumination compared to the incandescent lamp and lamp systems examined.
Date: April 7, 1980
Creator: Verderber, R. & Morse, O.
Object Type: Report
System: The UNT Digital Library
Liquid chromatographic analysis of coal surface properties (open access)

Liquid chromatographic analysis of coal surface properties

The main objectives of this proposed research work are to refine further the inverse liquid chromatography technique for the study of surface properties of raw coals, treated coals and coal minerals in water, to evaluate relatively surface properties of raw coals, treated coals and coal minerals by inverse liquid chromatography, and to evaluate flotability of various treated coals in conjunction with surface properties of coals. Coals such as Pittsburgh seam coal, Illinois No. 6 coal, Wyodak coal are chosen as representatives of high-rank bituminous coal, high volatile bituminous coal and subbituminous coal, respectively. Coal minerals such as pyrite and dolomite are chosen as representative coal minerals.
Date: April 7, 1992
Creator: Kwon, K.C.
Object Type: Report
System: The UNT Digital Library
Physical Sciences 2007 Science & Technology Highlights (open access)

Physical Sciences 2007 Science & Technology Highlights

The Physical Sciences Directorate applies frontier physics and technology to grand challenges in national security. Our highly integrated and multidisciplinary research program involves collaborations throughout Lawrence Livermore National Laboratory, the National Nuclear Security Administration, the Department of Energy, and with academic and industrial partners. The Directorate has a budget of approximately $150 million, and a staff of approximately 350 employees. Our scientists provide expertise in condensed matter and high-pressure physics, plasma physics, high-energy-density science, fusion energy science and technology, nuclear and particle physics, accelerator physics, radiation detection, optical science, biotechnology, and astrophysics. This document highlights the outstanding research and development activities in the Physical Sciences Directorate that made news in 2007. It also summarizes the awards and recognition received by members of the Directorate in 2007.
Date: April 7, 2008
Creator: Hazi, A U
Object Type: Report
System: The UNT Digital Library
Quantifying uncertainties of a Soil-Foundation Structure-Interaction System under Seismic Excitation (open access)

Quantifying uncertainties of a Soil-Foundation Structure-Interaction System under Seismic Excitation

We applied a spectrum of uncertainty quantification (UQ) techniques to the study of a two-dimensional soil-foundation-structure-interaction (2DSFSI) system (obtained from Professor Conte at UCSD) subjected to earthquake excitation. In the process we varied 19 uncertain parameters describing material properties of the structure and the soil. We present in detail the results for the different stages of our UQ analyses.
Date: April 7, 2008
Creator: Tong, C
Object Type: Report
System: The UNT Digital Library
Radiographic Capabilities of the MERCURY Monte Carlo Code (open access)

Radiographic Capabilities of the MERCURY Monte Carlo Code

MERCURY is a modern, parallel, general-purpose Monte Carlo code being developed at the Lawrence Livermore National Laboratory. Recently, a radiographic capability has been added. MERCURY can create a source of diagnostic, virtual particles that are aimed at pixels in an image tally. This new feature is compared to the radiography code, HADES, for verification and timing. Comparisons for accuracy were made using the French Test Object and for timing were made by tracking through an unstructured mesh. In addition, self consistency tests were run in MERCURY for the British Test Object and scattering test problem. MERCURY and HADES were found to agree to the precision of the input data. HADES appears to run around eight times faster than the MERCURY in the timing study. Profiling the MERCURY code has turned up several differences in the algorithms which account for this. These differences will be addressed in a future release of MERCURY.
Date: April 7, 2008
Creator: McKinley, M. Scott & Schach von Wittenau, Alexis E.
Object Type: Article
System: The UNT Digital Library
Liquid salt - very high temperature reactor : survey of sodium-cooled fast reactor fuel handling systems for relevant design and operating characteristics. (open access)

Liquid salt - very high temperature reactor : survey of sodium-cooled fast reactor fuel handling systems for relevant design and operating characteristics.

None
Date: April 7, 2006
Creator: Cahalan, J. E. & Taiwo, T. A.
Object Type: Report
System: The UNT Digital Library
The dipole picture in DIS: saturation and heavy quarks (open access)

The dipole picture in DIS: saturation and heavy quarks

We discuss the description of the proton structure function within the dipole factorization framework. We parameterize the forward dipole amplitude to account for saturation as predicted by the small-x QCD evolution equations. Contrarily to previous models, the saturation scale does not decrease when taking heavy quarks into account. We show that the same dipole amplitude also allows to reproduce diffractive data and exclusive vector meson production.
Date: April 7, 2008
Creator: Soyez,G.
Object Type: Article
System: The UNT Digital Library
A Method to Increase Current Density in a Mono Element Internal Tin Processed Superconductor Utilizing Zr Oxide to Refine Grain Size (open access)

A Method to Increase Current Density in a Mono Element Internal Tin Processed Superconductor Utilizing Zr Oxide to Refine Grain Size

The effect of Oxygen on (Nb1Zr)3Sn multifilament conductors manufactured by the Mono Element Internal Tin (MEIT) process was explored to improve the current density by refining the grain size. This followed work first done by General Electric on the Nb3Sn tape process. Techniques to fabricate the more difficult Nb1Zr composites are described and allowed fabrication of long lengths of .254 mm diameter wire from an 88.9 mm diameter billet. Oxygen was incorporated through the use of SnO2 mixed with tin powder and incorporated into the core. These were compared to samples with Ti+Sn and Cu+Sn cores. Heat treatments covered the range of 700 C to 1000 C. Current density vs. H, grain size, and reaction percentages are provided for the materials tested. The Oxygen gave superior results in the temperature range of 815-1000 C. It also stabilized the filament geometry of the array in comparison to the other additions at the higher temperatures. At 815 C a peak in layer Jc yielded values of 2537 A/mm2 at 12 T and 1353 A/mm2 at 15T, 8-22% and 30-73% greater respectively than 700 C values. Results with Oxygen at high temperature show the possibility of high speed continuous reaction of the composite …
Date: April 7, 2008
Creator: Bruce A. Zeitlin, Eric Gregory
Object Type: Report
System: The UNT Digital Library
High Spectral Resolution X-ray Observation of Magnetic CVs: EX Hya (open access)

High Spectral Resolution X-ray Observation of Magnetic CVs: EX Hya

In magnetic cataclysmic variables (CVs) the primary is a highly magnetized white dwarf (WD) whose field controls the accretion flow close to the WD, leading to a shock and accretion column that radiate chiefly in X-rays. We present preliminary results from a 500 ks Chandra HETG observation of the brightest magnetic CV EX Hya. From the observational dataset we are able to measure the temperature and density at different points of the cooling accretion column using sensitive line ratios. We also construct line-based light curves to search for rotational modulation of the X-ray emission.
Date: April 7, 2008
Creator: Luna, G; Brickhouse, N S & Mauche, C W
Object Type: Article
System: The UNT Digital Library
Glucose Regulates the Expression of the Apolipoprotein A5 Gene (open access)

Glucose Regulates the Expression of the Apolipoprotein A5 Gene

The apolipoprotein A5 gene (APOA5) is a key player in determining triglyceride concentrations in humans and mice. Since diabetes is often associated with hypertriglyceridemia, this study explores whether APOA5 gene expression is regulated by alteration in glucose homeostasis and the related pathways. D-glucose activates APOA5 gene expression in a time- and dose-dependent manner in hepatocytes, and the glycolytic pathway involved was determined using D-glucose analogs and metabolites. Together, transient transfections, electrophoretic mobility shift assays and chromatin immunoprecipitation assays show that this regulation occurs at the transcriptional level through an increase of USF1/2 binding to an E-box in the APOA5 promoter. We show that this phenomenon is not due to an increase of mRNA or protein expression levels of USF. Using protein phosphatases 1 and 2A inhibitor, we demonstrate that D-glucose regulates APOA5 gene via a dephosphorylation mechanism, thereby resulting in an enhanced USF1/2-promoter binding. Last, subsequent suppressions of USF1/2 and phosphatases mRNA through siRNA gene silencing abolished the regulation. We demonstrate that APOA5 gene is up regulated by D-glucose and USF through phosphatase activation. These findings may provide a new cross talk between glucose and lipid metabolism.
Date: April 7, 2008
Creator: Fruchart, Jamila; Nowak, Maxime; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Moitrot, Emmanuelle; Rommens, Corinne et al.
Object Type: Article
System: The UNT Digital Library
Analysis of Percent On-Cell Reformation of Methane in SOFC Stacks: Thermal, Electrical and Stress Analysis (open access)

Analysis of Percent On-Cell Reformation of Methane in SOFC Stacks: Thermal, Electrical and Stress Analysis

This report summarizes a parametric analysis performed to determine the effect of varying the percent on-cell reformation (OCR) of methane on the thermal and electrical performance for a generic, planar solid oxide fuel cell (SOFC) stack design. OCR of methane can be beneficial to an SOFC stack because the reaction (steam-methane reformation) is endothermic and can remove excess heat generated by the electrochemical reactions directly from the cell. The heat removed is proportional to the amount of methane reformed on the cell. Methane can be partially pre-reformed externally, then supplied to the stack, where rapid reaction kinetics on the anode ensures complete conversion. Thus, the thermal load varies with methane concentration entering the stack, as does the coupled scalar distributions, including the temperature and electrical current density. The endotherm due to the reformation reaction can cause a temperature depression on the anode near the fuel inlet, resulting in large thermal gradients. This effect depends on factors that include methane concentration, local temperature, and stack geometry.
Date: April 7, 2006
Creator: Recknagle, Kurtis P.; Yokuda, Satoru T.; Jarboe, Daniel T. & Khaleel, Mohammad A.
Object Type: Report
System: The UNT Digital Library
Nanoscale Synthesis and Characterization Laboratory Annual Report 2007 (open access)

Nanoscale Synthesis and Characterization Laboratory Annual Report 2007

The Nanoscale Synthesis and Characterization Laboratory's (NSCL) primary mission is to create and advance interdisciplinary research and development opportunities in nanoscience and technology. The NSCL is delivering on its mission providing Laboratory programs with scientific solutions through the use of nanoscale synthesis and characterization. While this annual report summarizes 2007 activities, we have focused on nanoporous materials, advanced high strength, nanostructured metals, novel 3-dimensional lithography and characterization at the nanoscale for the past 3 years. In these three years we have synthesized the first monolithic nanoporous metal foams with less than 10% relative density; we have produced ultrasmooth nanocrystalline diamond inertial confinement fusion capsules; we have synthesized 3-dimensional graded density structures from full density to 5% relative density using nanolithography; and we have established ultrasmall angle x-ray scattering as a non-destructive tool to determine the structure on the sub 300nm scale. The NSCL also has a mission to recruit and to train personnel for Lab programs. The NSCL continues to attract talented scientists to the Laboratory. Andrew Detor from Massachusetts Institute of Technology, Sutapa Ghosal from the University of California, Irvine, Xiang Ying Wang from Shanghai Institute of Technology, and Arne Wittstock from University of Bremen joined the NSCL this …
Date: April 7, 2008
Creator: Hamza, A V
Object Type: Report
System: The UNT Digital Library
Methods for Quantifying Uncertainty in Fast Reactor Analyses. (open access)

Methods for Quantifying Uncertainty in Fast Reactor Analyses.

Liquid-metal-cooled fast reactors in the form of sodium-cooled fast reactors have been successfully built and tested in the U.S. and throughout the world. However, no fast reactor has operated in the U.S. for nearly fourteen years. More importantly, the U.S. has not constructed a fast reactor in nearly 30 years. In addition to reestablishing the necessary industrial infrastructure, the development, testing, and licensing of a new, advanced fast reactor concept will likely require a significant base technology program that will rely more heavily on modeling and simulation than has been done in the past. The ability to quantify uncertainty in modeling and simulations will be an important part of any experimental program and can provide added confidence that established design limits and safety margins are appropriate. In addition, there is an increasing demand from the nuclear industry for best-estimate analysis methods to provide confidence bounds along with their results. The ability to quantify uncertainty will be an important component of modeling that is used to support design, testing, and experimental programs. Three avenues of UQ investigation are proposed. Two relatively new approaches are described which can be directly coupled to simulation codes currently being developed under the Advanced Simulation and …
Date: April 7, 2008
Creator: Fanning, T. H. & Fischer, P. F.
Object Type: Report
System: The UNT Digital Library
The SISCone and anti-k_t jet algorithms (open access)

The SISCone and anti-k_t jet algorithms

We illustrate how the midpoint and iterative cone (with progressive removal) algorithms fail to satisfy the fundamental requirements of infrared and collinear safety, causing divergences in the perturbative expansion. We introduce SISCone and the anti-k{sub t} algorithms as respective replacements that do not have those failures without any cost at the experimental level.
Date: April 7, 2008
Creator: Soyez,G.
Object Type: Article
System: The UNT Digital Library
Plasmas in particle accelerators: the warm-beam equilibria (open access)

Plasmas in particle accelerators: the warm-beam equilibria

For a complete set of equilibrium particle densities and temperature, the corresponding distribution functions including space charge effects are provided through solution of the inverse equilibrium problem. An accompanying orbit theory shows that the projected transverse rosette orbit can be analyzed into a circular rotation (drift) and a betatron-vortex gyration. In the presence of more general beam density profiles, the betatron vortex gyrations assume an elliptical rather than circular shape.
Date: April 7, 1981
Creator: Mark, J.W.K. & Smith, L.
Object Type: Report
System: The UNT Digital Library
Materials at extreme conditions: ICF targets (open access)

Materials at extreme conditions: ICF targets

Currently two simple theories are heavily used in laser-fusion research: the Thomas-Fermi-Dirac statistical model, and an atomic ionization model based on screened hydrogen like energy levels. Recent improvements in these theories are summarized. We show representation calculations of thermodynamic properties, ionization, x-ray emission rates and fast-ion stopping powers, and give a brief sketch of the major unresolved scientific questions.
Date: April 7, 1980
Creator: More, R.M.
Object Type: Article
System: The UNT Digital Library
Computer automation for chemistry instruments. Final report, February 1, 1980-January 31, 1981 (open access)

Computer automation for chemistry instruments. Final report, February 1, 1980-January 31, 1981

The work performed consisted of the following: (1) development of computer aided design software for polynomial filters and Butterworth-Chebychev filter design; (2) development of algorithms for resolving peaks in spectroscopic data; and (3) interaction with LLL personnel to develop a structure for automation of surface chemistry spectroscopy. Each work phase is discussed in detail.
Date: April 7, 1981
Creator: Brubaker, T.A.
Object Type: Report
System: The UNT Digital Library
Fluid dynamics of double diffusive systems (open access)

Fluid dynamics of double diffusive systems

A study of mixing processes in doubly diffusive systems is being conducted. Continuous gradients of two diffusing components (heat and salinity in our case) are being used as initial conditions, and forcing is introduced by lateral heating and surface shear. The goals of the proposed work include: (1) quantification of the effects of finite amplitude disturbances on stable, double diffusive systems, particularly with respect to lateral heating, (2) development of an improved understanding of the physical phenomena present in wind-driven shear flows in double diffusive stratified environments, (3) increasing our knowledge-base on turbulent flow in stratified environments and how to represent it, and (4) formulation of a numerical code for such flows. The work is being carried out in an experimental facility which is located in the Stanford Environmental Fluid Mechanics Laboratory, and on laboratory minicomputers and CRAY computers. In particular we are focusing on the following key issues: (1) the formation and propagation of double diffusive intrusions away from a heated wall and the effects of lateral heating on the double diffusive system; (2) the interaction between the double diffusively influenced fluxes and the turbulence induced fluxes; (3) the measurement of heat and mass fluxes; and (4) the influence …
Date: April 7, 1989
Creator: Koseff, J. R.
Object Type: Report
System: The UNT Digital Library
Isotropy of ultra-high-energy cosmic rays and multiple supernova I galactic source (open access)

Isotropy of ultra-high-energy cosmic rays and multiple supernova I galactic source

Ultra-high-energy cosmic rays are usually associated with an extragalactic origin. Active galactic nuclei are an unlikely source because of photon drag. Here the possibility of supernova events are considered. The time spread of arrival of 10/sup 20/ eV protons is 100 to 400 years at 10 to 20 kpc and the angular spread is +-15 to +-30/sup 0/ depending upon the Galactic field configuration. The time spread is sufficient to include several to a dozen type I SN. This is enough events and angular spread to include the observed data. The concentration of the observed events at the galactic poles is contradictory. The flux is reasonable if the observed flux and slope at 10/sup 12/ to 10/sup 15/ eV is characteristic of the source(s) and confined at this energy for roughly 100 traversals of the Galaxy, or 3 x 10/sup 6/ years.
Date: April 7, 1983
Creator: Colgate, S. A.
Object Type: Article
System: The UNT Digital Library