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Off-nadir optical remote sensing from satellites for vegetation identification

Description: Today's satellite remote sensing systems rely heavily on spectral signatures for scene identification from nadir observations. We propose to use angular signatures as complementary scene identifiers when off-nadir sensing is possible. Specifically, the hot spot (Heiligenschein) of plant canopies is recognized as an atmosphere-invariant angular reflectance signature that carries information about the plant stand architecture which may be useful for instant crop identification from off-nadir sate… more
Date: May 30, 1986
Creator: Gerstl, S.A.W.
Partner: UNT Libraries Government Documents Department
open access

Production and survival of /sup 99/Tc in He-shell recurrent thermal pulses

Description: After a brief introduction to the present state of art of nuclear beta-decay studies in astrophysics, we report our recent work on the long-standing /sup 99/Tc problem. Having combined a detailed study of the recurrent He-shell thermal-pulse, third dredge-up episodes in a 2.25 M/sub solar/ star and an s-process network calculation, we show that a substantial amount of /sup 99/Tc can be produced by the s-process and can survive to be dredged up to the stellar surface. We stress that the factual … more
Date: May 30, 1985
Creator: Takahashi, K.; Mathews, G. J.; Ward, R. A. & Becker, S. A.
Partner: UNT Libraries Government Documents Department
open access

Standard method for economic analyses of inertial confinement fusion power plants

Description: A standard method for calculating the total capital cost and the cost of electricity for a typical inertial confinement fusion electric power plant has been developed. A standard code of accounts at the two-digit level is given for the factors making up the total capital cost of the power plant. Equations are given for calculating the indirect capital costs, the project contingency, and the time-related costs. Expressions for calculating the fixed charge rate, which is necessary to determine th… more
Date: May 30, 1986
Creator: Meier, W. R.
Partner: UNT Libraries Government Documents Department
open access

Transmission electron microscopy of actinide materials

Description: Actinide metallurgy, crystallography, physics, and chemistry are of great interest due to the unique behavior of the 5f states that dominate the electronic structure. The 5f states produce a wide range of fascinating behaviors in the actinide materials. from superconductivity to exotic magnetism. Accordingly, they are of great interest, but are difficult to work with. Transmission electron microscopy (TEM) can overcome many of the problems of working with actinide materials and can be used to i… more
Date: May 30, 2006
Creator: Moore, K
Partner: UNT Libraries Government Documents Department
open access

Seeing the Unseeable

Description: The SciDAC Visualization and Analytics Center for Enabling Technologies (VACET) isa highly productive effort combining the forces of leading visualization researchersfrom five different institutions to solve some of the most challenging dataunderstanding problems in modern science. The VACET technology portfolio isdiverse, spanning all typical visual data analysis use models and effectivelybalancing forward-looking research with focused software architecture andengineering resulting in a produc… more
Date: May 30, 2008
Creator: Bethel, Edward W; Bethel, E. Wes; Johnson, Chris; Hansen, Charles; Silva, Claudio; Parker, Steven et al.
Partner: UNT Libraries Government Documents Department
open access

Radio AGN in 13,240 galaxy clusters from the Sloan Digital Sky Survey

Description: We correlate the positions of 13,240 Brightest Cluster Galaxies (BCGs) with 0.1 {le} z {le} 0.3 from the maxBCG catalog with radio sources from the FIRST survey to study the sizes and distributions of radio AGN in galaxy clusters. We find that 19.7% of our BCGs are radio-loud, and this fraction depends on the stellar mass of the BCG, and to a lesser extent on the richness of the parent cluster (in the sense of increasing radio loudness with increasing mass). The intrinsic size of the radio emis… more
Date: May 30, 2007
Creator: Croft, S.; de Vries, W. & Becker, R.
Partner: UNT Libraries Government Documents Department
open access

Monitoring/Verification using DMS: TATP Example

Description: Field-rugged and field-programmable differential mobility spectrometry (DMS) networks provide highly selective, universal monitoring of vapors and aerosols at detectable levels from persons or areas involved with illicit chemical/biological/explosives (CBE) production. CBE sensor motes used in conjunction with automated fast gas chromatography with DMS detection (GC/DMS) verification instrumentation integrated into situational operations-management systems can be readily deployed and optimized … more
Date: May 30, 2008
Creator: Weeks, Stephan; Kyle, Kevin & Manard, Manuel
Partner: UNT Libraries Government Documents Department
open access

A Novel Class of High-TC Ferromagnetic Semiconductors

Description: We have grown single crystals of novel ruthenates (Sr,Ba)(Fe,Co){sub 2+x}Ru{sub 4-x}O{sub 11} that exhibit long-range ferromagnetic order well above room temperature, accompanied by narrow-gap semiconducting properties that include a large anomalous Hall conductance, low resistivity, high carrier concentration and low coercive field, which are properties well suited to spintronic applications. X-ray diffraction, EDX, neutron diffraction and x-ray absorption measurements on single crystals firml… more
Date: May 30, 2008
Creator: Shlyk, L. V.; Kryukov, S. A.; De Long, L. E.; Schupp-Niewa, B.; Niewa, R.; Lynn, J. W. et al.
Partner: UNT Libraries Government Documents Department
open access

Coupled Model Simulations of Boreal Summer Intraseasonal (30-50 day) Variability, Part 1: Systematic Errors and Caution on Use of Metrics

Description: Boreal summer intraseasonal (30-50 day) variability (BSISV) over the Asian monsoon region is more complex than its boreal winter counterpart, the Madden-Julian oscillation (MJO), since it also exhibits northward and northwestward propagating convective components near India and over the west Pacific. Here we analyze the BSISV in the CMIP3 and two CMIP2+ coupled ocean-atmosphere models. Though most models exhibit eastward propagation of convective anomalies over the Indian Ocean, difficulty rema… more
Date: May 30, 2007
Creator: Sperber, K R & Annamalai, H
Partner: UNT Libraries Government Documents Department
open access

TEMPEST Simulations of Collisionless Damping of Geodesic-Acoustic Mode in Edge Plasma Pedestal

Description: The fully nonlinear (full-f) 4D TEMPEST gyrokinetic continuum code produces frequency, collisionless damping of GAM and zonal flow with fully nonlinear Boltzmann electrons for the inverse aspect ratio {epsilon}-scan and the tokamak safety factor q-scan in homogeneous plasmas. The TEMPEST simulation shows that GAM exists in edge plasma pedestal for steep density and temperature gradients, and an initial GAM relaxes to the standard neoclassical residual, rather than Rosenbluth-Hinton residual due… more
Date: May 30, 2007
Creator: Xu, X. Q.; Xiong, Z.; Nevins, W. M. & McKee, G. R.
Partner: UNT Libraries Government Documents Department
open access

Solvable Examples of Drift and Diffusion of Ions in Non-uniform Electric Fields

Description: The drift and diffusion of a cloud of ions in a fluid are distorted by an inhomogeneous electric field. If the electric field carries the center of the distribution in a straight line and the field configuration is suitably symmetric, the distortion can be calculated analytically. We examine the specific examples of fields with cylindrical and spherical symmetry in detail assuming the ion distributions to be of a generally Gaussian form. The effects of differing diffusion coefficients in the tr… more
Date: May 30, 2008
Creator: Cahn, Robert; Cahn, Robert N. & Jackson, John David
Partner: UNT Libraries Government Documents Department
open access

HIGH RAPIDITY PHYSICS WITH THE BRAHMS EXPERIMENT.

Description: We report the study of the nuclear modification factor R{sub AuAu} as function of p{sub T} and pseudo-rapidity in Au+Au collisions at top RHIC energy. We find this quantity almost independent of pseudo-rapidity. We use the {bar p}/{pi}{sup -} ratio as a probe of the parton density and the degree of thermalization of the medium formed by the collision. The {bar p}/{pi}{sup -} ratio has a clear rapidity dependence. The combination of these two measurements suggests that the pseudo-rapidity depend… more
Date: May 30, 2006
Creator: DEBBE,R.
Partner: UNT Libraries Government Documents Department
open access

Performance Engineering in the Community Atmosphere Model

Description: The Community Atmosphere Model (CAM) is the atmospheric component of the Community Climate System Model (CCSM) and is the primary consumer of computer resources in typical CCSM simulations. Performance engineering has been an important aspect of CAM development throughout its existence. This paper briefly summarizes these efforts and their impacts over the past five years.
Date: May 30, 2006
Creator: Worley, P.; Mirin, A.; Drake, J. & Sawyer, W.
Partner: UNT Libraries Government Documents Department
open access

The Breathing Orbital Valence Bond Method in Diffusion Monte Carlo: C-H Bond Dissociation ofAcetylene

Description: This study explores the use of breathing orbital valence bond (BOVB) trial wave functions for diffusion Monte Carlo (DMC). The approach is applied to the computation of the carbon-hydrogen (C-H) bond dissociation energy (BDE) of acetylene. DMC with BOVB trial wave functions yields a C-H BDE of 132.4 {+-} 0.9 kcal/mol, which is in excellent accord with the recommended experimental value of 132.8 {+-} 0.7 kcal/mol. These values are to be compared with DMC results obtained with single determinant … more
Date: May 30, 2008
Creator: Domin, D.; Braida, Benoit & Lester Jr., William A.
Partner: UNT Libraries Government Documents Department
open access

DEVELOPMENT OF PROTOTYPE TITANATE ION EXCHANGE LOADED MEMBRANES FOR STRONTIUM, CESIUM AND ACTINIDE DECONTAMINATION FROM AQUEOUS MEDIA

Description: We have successfully incorporated high surface area particles of titanate ion exchange materials (monosodium titanate and crystalline silicotitanate) with acceptable particle size distribution into porous and inert support membrane fibrils consisting of polytetrafluoroethylene (Teflon{reg_sign}), polyethylene and cellulose materials. The resulting membrane sheets, under laboratory conditions, were used to evaluate the removal of surrogate radioactive materials for cesium-137 and strontium-90 fr… more
Date: May 30, 2008
Creator: Oji, L; Keisha Martin, K & David Hobbs, D
Partner: UNT Libraries Government Documents Department
open access

Oxidation and aging in U and Pu probed by spin-orbit sum rule analysis: indications for covalent metal-oxide bonds

Description: Actinide physics and chemistry are of great interest due to the unique behavior of the 5f states that dominate the electronic structure. How these states evolve with changes in crystal structure, alloying, oxidation state, and radiation damage is of considerable importance to better understand these materials. Oxidations state: How are the f electrons bonding in actinide oxides? Radiation damage: U and Pu evolve with time due to self-induced radiation damage of the lattice. How does this affect… more
Date: May 30, 2006
Creator: Moore, K.; Schwartz, A.; Wall, M.; Haire, D. & Der Laan, G. V.
Partner: UNT Libraries Government Documents Department
open access

BREN Tower: A Monument to the Material Culture of Radiation Dosimetry Research

Description: With a height of more than 1,500 feet, the BREN (Bare Reactor Experiment, Nevada) Tower dominates the surrounding desert landscape of the Nevada Test Site. Associated with the nuclear research and atmospheric testing programs carried out during the 1950s and 1960s, the tower was a vital component in a series of experiments aimed at characterizing radiation fields from nuclear detonations. Research programs conducted at the tower provided the data for the baseline dosimetry studies crucial to de… more
Date: May 30, 2008
Creator: Edwards, Susan
Partner: UNT Libraries Government Documents Department
open access

The Plowshare Program: Peaceful Applications for Nuclear Detonations

Description: The U.S. Atomic Energy Commission's Plowshare Program focused on developing the capability to use nuclear detonations for civil works projects and industrial applications. The participants envisioned canals and harbors constructed quickly and cheaply and the augmentation of natural gas, oil, and geothermal power production. The Plowshare Program began in the 1950s and ended in the 1970s. The archaeological effort to relocate and record places associated with this project has identified a unique… more
Date: May 30, 2008
Creator: Beck, C.; Edwards, S. & King, M.
Partner: UNT Libraries Government Documents Department
open access

CHARGED PARTICLE PRODUCTION AT HIGH RAPIDITY IN p+p COLLISIONS AT RHIC.

Description: This report describes the recent analysis of identified charged particle production at high rapidity performed on data collected from p+p collisions at RHIC ({radical}s = 200 GeV). The extracted invariant cross-sections compare well to NLO pQCD calculations. However, a puzzling high yield of protons at high rapidity and p{sub T} has been found.
Date: May 30, 2006
Creator: DEBBE,R.
Partner: UNT Libraries Government Documents Department
open access

A Compact Torus Fusion Reactor Utilizing a Continuously Generated Strings of CT's. The CT String Reactor, CTSR.

Description: A fusion reactor is described in which a moving string of mutually repelling compact toruses (alternating helicity, unidirectional Btheta) is generated by repetitive injection using a magnetized coaxial gun driven by continuous gun current with alternating poloidal field. An injected CT relaxes to a minimum magnetic energy equilibrium, moves into a compression cone, and enters a conducting cylinder where the plasma is heated to fusion-producing temperature. The CT then passes into a blanketed r… more
Date: May 30, 2007
Creator: Hartman, C W; Reisman, D B; McLean, H S & Thomas, J
Partner: UNT Libraries Government Documents Department
open access

SORPTION OF URANIUM, PLUTONIUM AND NEPTUNIUM ONTO SOLIDS PRESENT IN HIGH CAUSTIC NUCLEAR WASTE STORAGE TANKS

Description: Solids such as granular activated carbon, hematite and sodium phosphates, if present as sludge components in nuclear waste storage tanks, have been found to be capable of precipitating/sorbing actinides like plutonium, neptunium and uranium from nuclear waste storage tank supernatant liqueur. Thus, the potential may exists for the accumulation of fissile materials in such nuclear waste storage tanks during lengthy nuclear waste storage and processing. To evaluate the nuclear criticality safety … more
Date: May 30, 2008
Creator: Oji, L; Bill Wilmarth, B & David Hobbs, D
Partner: UNT Libraries Government Documents Department
open access

The Use of Trust Regions in Kohn-Sham Total EnergyMinimization

Description: The Self Consistent Field (SCF) iteration, widely used forcomputing the ground state energy and the corresponding single particlewave functions associated with a many-electronatomistic system, is viewedin this paper as an optimization procedure that minimizes the Kohn-Shamtotal energy indirectly by minimizing a sequence of quadratic surrogatefunctions. We point out the similarity and difference between the totalenergy and the surrogate, and show how the SCF iteration can fail whenthe minimizer … more
Date: May 30, 2006
Creator: Yang, Chao; Meza, Juan C. & Wang, Lin-wang
Partner: UNT Libraries Government Documents Department
open access

Scale dependence of the effective matrix diffusion coefficient:some analytical results

Description: Matrix diffusion is an important process affecting solutetransport in fractured rock, and the matrix diffusion coefficient is akey parameter for describing this process. Previous studies haveindicated that the effective matrix-diffusion coefficient values,obtained from a number of field tracer tests, are enhanced in comparisonwith local values and may increase with test scale. In thiscommunication, we develop analytical expressions for the effective matrixdiffusion coefficient for two simple fr… more
Date: May 30, 2005
Creator: Liu, H. H.; Zhang, Y. Q. & Molz, F. J.
Partner: UNT Libraries Government Documents Department
open access

Monte Carlo Simulations of High-Speed, Time-Gated MCP-based X-ray Detectors: Saturation Effects in DC Pulsed Modes and Detector Dynamic Range

Description: We present here results of continued efforts to understand the performance of microchannel plate (MCP)–based, high-speed, gated, x-ray detectors. This work involves the continued improvement of a Monte Carlo simulation code to describe MCP performance coupled with experimental efforts to better characterize such detectors. Our goal is a quantitative description of MCP saturation behavior in both static and pulsed modes. A new model of charge buildup on the walls of the MCP channels is briefly d… more
Date: May 30, 2008
Creator: Craig Kruschwitz, Ming Wu, Ken Moy, Greg Rochau
Partner: UNT Libraries Government Documents Department
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