Laser driven hydrodynamic instability experiments. Revision 1 (open access)

Laser driven hydrodynamic instability experiments. Revision 1

An extensive series of experiments has been conducted on the Nova laser to measure hydrodynamic instabilities in planar foils accelerated by x-ray ablation. Single mode experiments allow a measurement of the fundamental growth rates from the linear well into the nonlinear regime. Two-mode foils allow a first direct observation of mode coupling. Surface-finish experiments allow a measurement of the evolution of a broad spectrum of random initial modes.
Date: February 17, 1993
Creator: Remington, B. A.; Weber, S. V.; Haan, S. W.; Kilkenny, J. D.; Glendinning, S. G.; Wallace, R. J. et al.
System: The UNT Digital Library
Covariances of evaluated nuclear data based upon uncertainty information of experimental data and nuclear models (open access)

Covariances of evaluated nuclear data based upon uncertainty information of experimental data and nuclear models

A straightforward derivation is presented for the covariance matrix of evaluated cross sections based on the covariance matrix of the experimental data and propagation through nuclear model parameters. 10 refs.
Date: November 17, 1986
Creator: Poenitz, W. P. & Peelle, R. W.
System: The UNT Digital Library
Extensional wave attenuation and velocity in partially-saturated sand in the sonic frequency range (open access)

Extensional wave attenuation and velocity in partially-saturated sand in the sonic frequency range

Extensional wave attenuation and velocity measurements on a high permeability Monterey sand were performed over a range of gas saturations for imbibition and degassing conditions. These measurements were conducted using extensional wave pulse propagation and resonance over a 1 - 9 kHz frequency range for a hydrostatic confining pressure of 8.3 MPa. Analysis of the extensional wave data and the corresponding X-ray CT images of the gas saturation show strong attenuation resulting from the presence of the gas (QE dropped from 300 for the dry sand to 30 for the partially-saturated sand), with larger attenuation at a given saturation resulting from heterogeneous gas distributions. The extensional wave velocities are in agreement with Gassmann theory for the test with near-homogeneous gas saturation and with a patchy saturation model for the test with heterogeneous gas saturation. These results show that partially-saturated sands under moderate confining pressure can produce strong intrinsic attenuation for extensional waves.
Date: June 17, 2002
Creator: Liu, Z.; Rector, J. W.; Nihei, K. T.; Tomutsa, L.; Myer, L. R. & Nakagawa, S.
System: The UNT Digital Library
3-D Numerical Modeling of a Complex Salt Structure (open access)

3-D Numerical Modeling of a Complex Salt Structure

Reliably processing, imaging, and interpreting seismic data from areas with complicated structures, such as sub-salt, requires a thorough understanding of elastic as well as acoustic wave propagation. Elastic numerical modeling is an essential tool to develop that understanding. While 2-D elastic modeling is in common use, 3-D elastic modeling has been too computationally intensive to be used routinely. Recent advances in computing hardware, including commodity-based hardware, have substantially reduced computing costs. These advances are making 3-D elastic numerical modeling more feasible. A series of example 3-D elastic calculations were performed using a complicated structure, the SEG/EAGE salt structure. The synthetic traces show that the effects of shear wave propagation can be important for imaging and interpretation of images, and also for AVO and other applications that rely on trace amplitudes. Additional calculations are needed to better identify and understand the complex wave propagation effects produced in complicated structures, such as the SEG/EAGE salt structure.
Date: February 17, 2000
Creator: House, L.; Larsen, S. & Bednar, J. B.
System: The UNT Digital Library
ESTIMATING IMPURITIES IN SURPLUS PLUTONIUM FOR DISPOSITION (open access)

ESTIMATING IMPURITIES IN SURPLUS PLUTONIUM FOR DISPOSITION

The United States holds at least 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition of the National Nuclear Security Administration and the DOE Office of Environmental Management. Many of the items that require disposition are only partially characterized, and SRNL uses a variety of techniques to predict the isotopic and chemical properties that are important for processing through the Mixed Oxide Fuel Fabrication Facility and alternative disposition paths. Recent advances in laboratory tools, including Prompt Gamma Analysis and Peroxide Fusion treatment, provide data on the existing inventories that will enable disposition without additional, costly sampling and destructive analysis.
Date: July 17, 2013
Creator: Allender, J. & Moore, E.
System: The UNT Digital Library
Electron Anomalous Magnetic Moment in Basis Light-Front Quantization Approach (open access)

Electron Anomalous Magnetic Moment in Basis Light-Front Quantization Approach

We apply the Basis Light-Front Quantization (BLFQ) approach to the Hamiltonian field theory of Quantum Electrodynamics (QED) in free space. We solve for the mass eigenstates corresponding to an electron interacting with a single photon in light-front gauge. Based on the resulting non-perturbative ground state light-front amplitude we evaluate the electron anomalous magnetic moment. The numerical results from extrapolating to the infinite basis limit reproduce the perturbative Schwinger result with relative deviation less than 1.2%. We report significant improvements over previous works including the development of analytic methods for evaluating the vertex matrix elements of QED.
Date: February 17, 2012
Creator: Zhao, Xingbo; Honkanen, Heli; Maris, Pieter; Vary, James P. & Brodsky, Stanley J.
System: The UNT Digital Library
Combined effects of elevated temperature and Deepwater Horizon oil exposure on the cardiac performance of larval mahi-mahi, Coryphaena hippurus (open access)

Combined effects of elevated temperature and Deepwater Horizon oil exposure on the cardiac performance of larval mahi-mahi, Coryphaena hippurus

This article investigates physiological responses of larval fish to interactions between anthropogenic crude oile xposure andn atural factors.
Date: October 17, 2018
Creator: Perrichon, Prescilla; Mager, Edward M.; Pasparakis, Christina; Stieglitz, John D.; Benetti, Daniel D.; Grosell, Martin et al.
System: The UNT Digital Library
MicrobesOnline: an integrated portal for comparative and functional genomics (open access)

MicrobesOnline: an integrated portal for comparative and functional genomics

Since 2003, MicrobesOnline (http://www.microbesonline.org) has been providing a community resource for comparative and functional genome analysis. The portal includes over 1000 complete genomes of bacteria, archaea and fungi and thousands of expression microarrays from diverse organisms ranging from model organisms such as Escherichia coli and Saccharomyces cerevisiae to environmental microbes such as Desulfovibrio vulgaris and Shewanella oneidensis. To assist in annotating genes and in reconstructing their evolutionary history, MicrobesOnline includes a comparative genome browser based on phylogenetic trees for every gene family as well as a species tree. To identify co-regulated genes, MicrobesOnline can search for genes based on their expression profile, and provides tools for identifying regulatory motifs and seeing if they are conserved. MicrobesOnline also includes fast phylogenetic profile searches, comparative views of metabolic pathways, operon predictions, a workbench for sequence analysis and integration with RegTransBase and other microbial genome resources. The next update of MicrobesOnline will contain significant new functionality, including comparative analysis of metagenomic sequence data. Programmatic access to the database, along with source code and documentation, is available at http://microbesonline.org/programmers.html.
Date: September 17, 2009
Creator: Dehal, Paramvir S.; Joachimiak, Marcin P.; Price, Morgan N.; Bates, John T.; Baumohl, Jason K.; Chivian, Dylan et al.
System: The UNT Digital Library
Proceedings of the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration (open access)

Proceedings of the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration

These proceedings contain papers prepared for the 24th Seismic Research Review: Nuclear Explosion Monitoring: Innovation and Integration, held 17-19 September, 2002 in Ponte Vedra Beach, Florida. These papers represent the combined research related to ground-based nuclear explosion monitoring funded by the National Nuclear Security Administration (NNSA), Defense Threat Reduction Agency (DTRA), and other invited sponsors. The scientific objectives of the research are to improve the United States capability to detect, locate, and identify nuclear explosions. The purpose of the meeting is to provide the sponsoring agencies, as well as potential users, an opportunity to review research accomplished during the preceding year and to discuss areas of investigation for the coming year. For the researchers, it provides a forum for the exchange of scientific information toward achieving program goals, and an opportunity to discuss results and future plans. Paper topics include: seismic regionalization and calibration; detection and location of sources; wave propagation from source to receiver; the nature of seismic sources, including mining practices; hydroacoustic, infrasound, and radionuclide methods; on-site inspection; and data processing.
Date: September 17, 2002
Creator: Warren, N. Jill
System: The UNT Digital Library
Buckingham (1907): An appreciation (open access)

Buckingham (1907): An appreciation

Nearly a century ago, Edgar Buckingham (1907) published a seminal work on the movement of soil moisture which is part of the foundation of modern soil physics. It also constitutes a pioneering contribution in the study of multi-phase flow in porous media. A physicist, Buckingham took on an earth science issue of importance to society, and produced superb basic science as a byproduct. Buckingham impresses us with his ability to combine experiment and theory, and his capacity to intuitively explain difficult ideas to a wide audience. Science progresses both by gradual accretion of knowledge, and by sudden influx of ideas. Buckingham's contribution belongs in the latter category. After a brief, four-year rendezvous with soil science, he went on to pursue a long and distinguished career in physics with the National Bureau of Standards. This paper is an appreciation of Buckingham's contribution on soil moisture in the context of contemporary developments in diffusion theory, and the rapid growth of science in America at the turn of the twentieth century.
Date: November 17, 2004
Creator: Narasimhan, T. N.
System: The UNT Digital Library
Heavy Quarkonium Production in Single Transverse Polarized HighEnergy Scattering (open access)

Heavy Quarkonium Production in Single Transverse Polarized HighEnergy Scattering

We formulate the single transverse spin asymmetry in heavyquarkoniumproduction in lepton-nucleon and nucleon-nucleon collisionsinthe non-relativistic limit. We findthat the asymmetry is very sensitiveto the production mechanism. The finalstate interactions with the heavyquark and antiquark cancel out among themselves whenthe pair are producedin a color-single configuration, or cancel out with the initialstateinteraction in pp scattering when they are in color-octet. As aconsequence, the asymmetry is nonzero in ep collisions only in thecolor-octet model, whereas in pp collisions only in the color-singletmodel.
Date: January 17, 2008
Creator: Yuan, Feng
System: The UNT Digital Library
ULTRACLEAN FUELS PRODUCTION AND UTILIZATION FOR THE TWENTY-FIRST CENTURY: ADVANCES TOWARDS SUSTAINABLE TRANSPORTATION FUELS (open access)

ULTRACLEAN FUELS PRODUCTION AND UTILIZATION FOR THE TWENTY-FIRST CENTURY: ADVANCES TOWARDS SUSTAINABLE TRANSPORTATION FUELS

Ultraclean fuels production has become increasingly important as a method to help decrease emissions and allow the introduction of alternative feed stocks for transportation fuels. Established methods, such as Fischer-Tropsch, have seen a resurgence of interest as natural gas prices drop and existing petroleum resources require more intensive clean-up and purification to meet stringent environmental standards. This review covers some of the advances in deep desulfurization, synthesis gas conversion into fuels and feed stocks that were presented at the 245th American Chemical Society Spring Annual Meeting in New Orleans, LA in the Division of Energy and Fuels symposium on "Ultraclean Fuels Production and Utilization".
Date: June 17, 2013
Creator: Fox, E.
System: The UNT Digital Library
Slow Hydrogen Transfer Reactions of Oxo- and Hydroxo-Vanadium Compounds: The Importance of Intrinsic Barriers (open access)

Slow Hydrogen Transfer Reactions of Oxo- and Hydroxo-Vanadium Compounds: The Importance of Intrinsic Barriers

Article on slow hydrogen atom transfer reactions of oxo- and hydroxo-vanadium compounds and the importance of intrinsic barriers.
Date: March 17, 2009
Creator: Waidmann, Christopher; Zhou, Xin; Tsai, Erin A.; Kaminsky, Werner; Hrovat, David A.; Borden, Weston T. et al.
System: The UNT Digital Library
Submicron X-ray diffraction (open access)

Submicron X-ray diffraction

At the Advanced Light Source in Berkeley the authors have instrumented a beam line that is devoted exclusively to x-ray micro diffraction problems. By micro diffraction they mean those classes of problems in Physics and Materials Science that require x-ray beam sizes in the sub-micron range. The instrument is for instance, capable of probing a sub-micron size volume inside micron sized aluminum metal grains buried under a silicon dioxide insulating layer. The resulting Laue pattern is collected on a large area CCD detector and automatically indexed to yield the grain orientation and deviatoric (distortional) strain tensor of this sub-micron volume. A four-crystal monochromator is then inserted into the beam, which allows monochromatic light to illuminate the same part of the sample. Measurement of diffracted photon energy allows for the determination of d spacings. The combination of white and monochromatic beam measurements allow for the determination of the total strain/stress tensor (6 components) inside each sub-micron sized illuminated volume of the sample.
Date: August 17, 2000
Creator: MacDowell, Alastair; Celestre, Richard; Tamura, Nobumichi; Spolenak, Ralph; Valek, Bryan; Brown, Walter et al.
System: The UNT Digital Library
Recent advances in processing negation (open access)

Recent advances in processing negation

This article surveys previous work on negation with an emphasis on computational approaches.
Date: December 17, 2021
Creator: Morante, Roser & Blanco, Eduardo
System: The UNT Digital Library
Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation (open access)

Metabolic analysis of the soil microbe Dechloromonas aromatica str. RCB: indications of a surprisingly complex life-style and cryptic anaerobic pathways for aromatic degradation

Initial interest in Dechloromonas aromatica strain RCB arose from its ability to anaerobically degrade benzene. It is also able to reduce perchlorate and oxidize chlorobenzoate, toluene, and xylene, creating interest in using this organism for bioremediation. Little physiological data has been published for this microbe. It is considered to be a free-living organism. The a priori prediction that the D. aromatica genome would contain previously characterized 'central' enzymes involved in anaerobic aromatic degradation proved to be false, suggesting the presence of novel anaerobic aromatic degradation pathways in this species. These missing pathways include the benzyl succinyl synthase (bssABC) genes (responsible for formate addition to toluene) and the central benzoylCoA pathway for monoaromatics. In depth analyses using existing TIGRfam, COG, and InterPro models, and the creation of de novo HMM models, indicate a highly complex lifestyle with a large number of environmental sensors and signaling pathways, including a relatively large number of GGDEF domain signal receptors and multiple quorum sensors. A number of proteins indicate interactions with an as yet unknown host, as indicated by the presence of predicted cell host remodeling enzymes, effector enzymes, hemolysin-like proteins, adhesins, NO reductase, and both type III and type VI secretory complexes. Evidence of …
Date: November 17, 2008
Creator: Salinero, Kennan Kellaris; Keller, Keith; Feil, William S.; Feil, Helene; Trong, Stephan; Di Bartolo, Genevieve et al.
System: The UNT Digital Library
New insights into potential functions for the protein 4.1superfamily of proteins in kidney epithelium (open access)

New insights into potential functions for the protein 4.1superfamily of proteins in kidney epithelium

Members of the protein 4.1 family of adapter proteins are expressed in a broad panel of tissues including various epithelia where they likely play an important role in maintenance of cell architecture and polarity and in control of cell proliferation. We have recently characterized the structure and distribution of three members of the protein 4.1 family, 4.1B, 4.1R and 4.1N, in mouse kidney. We describe here binding partners for renal 4.1 proteins, identified through the screening of a rat kidney yeast two-hybrid system cDNA library. The identification of putative protein 4.1-based complexes enables us to envision potential functions for 4.1 proteins in kidney: organization of signaling complexes, response to osmotic stress, protein trafficking, and control of cell proliferation. We discuss the relevance of these protein 4.1-based interactions in kidney physio-pathology in the context of their previously identified functions in other cells and tissues. Specifically, we will focus on renal 4.1 protein interactions with beta amyloid precursor protein (beta-APP), 14-3-3 proteins, and the cell swelling-activated chloride channel pICln. We also discuss the functional relevance of another member of the protein 4.1 superfamily, ezrin, in kidney physiopathology.
Date: June 17, 2005
Creator: Calinisan, Venice; Gravem, Dana; Chen, Ray Ping-Hsu; Brittin,Sachi; Mohandas, Narla; Lecomte, Marie-Christine et al.
System: The UNT Digital Library
ARKENSTONE – I. A novel method for robustly capturing high specific energy outflows in cosmological simulations (open access)

ARKENSTONE – I. A novel method for robustly capturing high specific energy outflows in cosmological simulations

Article describes how ARKENSTONE is a new model for multiphase, stellar feedback-driven galactic winds designed for inclusion in coarse resolution cosmological simulations. In this first paper of a series, the authors describe the features that allow ARKENSTONE to properly treat high specific energy wind components and demonstrate them using idealized non-cosmological simulations of a galaxy with a realistic circumgalactic medium (CGM) using the AREPO code.
Date: October 17, 2023
Creator: Smith, Matthew C.; Fielding, Drummond B.; Bryan, Greg L.; Kim, Chang-Goo; Ostriker, Eve C.; Somerville, Rachel S. et al.
System: The UNT Digital Library