Remaining Sites Verification Package for the 1607-F7, 141-M Building Septic Tank, Waste Site Reclassification Form 2006-040 (open access)

Remaining Sites Verification Package for the 1607-F7, 141-M Building Septic Tank, Waste Site Reclassification Form 2006-040

The 1607-F7, 141-M Building Septic Tank waste site was a septic tank and drain field that received sanitary sewage from the former 141-M Building. Remedial action was performed in August and November 2005. The results of verification sampling demonstrate that residual contaminant concentrations support future unrestricted land uses that can be represented by a rural-residential scenario. These results also show that residual concentrations support unrestricted future use of shallow zone soil and that contaminant levels remaining in the soil are protective of groundwater and the Columbia River.
Date: October 19, 2006
Creator: Dittmer, L. M.
Object Type: Report
System: The UNT Digital Library
Orbital HP-Clouds for Solving Schrödinger Equation in Quantum Mechanics (open access)

Orbital HP-Clouds for Solving Schrödinger Equation in Quantum Mechanics

Solving Schroedinger equation in quantum mechanics presents a challenging task in numerical methods due to the high order behavior and high dimension characteristics in the wave functions, in addition to the highly coupled nature between wave functions. This work introduces orbital and polynomial enrichment functions to the partition of unity for solution of Schroedinger equation under the framework of HP-Clouds. An intrinsic enrichment of orbital function and extrinsic enrichment of monomial functions are proposed. Due to the employment of higher order basis functions, a higher order stabilized conforming nodal integration is developed. The proposed methods are implemented using the density functional theory for solution of Schroedinger equation. Analysis of several single and multi-electron/nucleus structures demonstrates the effectiveness of the proposed method.
Date: October 19, 2006
Creator: Chen, J. S.; Hu, W. & Puso, M. A.
Object Type: Article
System: The UNT Digital Library
The Deep2 Galaxy Redshift Survey: Mean Ages and Metallicities ofRed Field Galaxies at Z ~; 0.9 from Stacked Keck/Deimos Spectra (open access)

The Deep2 Galaxy Redshift Survey: Mean Ages and Metallicities ofRed Field Galaxies at Z ~; 0.9 from Stacked Keck/Deimos Spectra

As part of the DEEP2 galaxy redshift survey, we analyze absorption line strengths in stacked Keck/DEIMOS spectra of red field galaxies with weak to no emission lines, at redshifts 0.7 {approx}< z {approx}< 1. Comparison with models of stellar population synthesis shows that red galaxies at z {approx} 0:9 have mean luminosity-weighted ages of the order of only 1 Gyr and at least solar metallicities. These ages cannot be reconciled with a scenario where all stars evolved passively after forming at very high z. Rather, a significant fraction of stars can be no more than 1 Gyr old, which means that some star formation in the stacked populations continued to at least z {approx} 1:2. Furthermore, a comparison of these distant galaxies with a local SDSS sample, using stellar populations synthesis models, shows that the drop in the equivalent width of H{delta} from z {approx} 0:9 to 0.1 is less than predicted by passively evolving models. This admits of two interpretations: either each individual galaxy experiences continuing low-level star formation, or the red-sequence galaxy population from z {approx} 0:9 to 0.1 is continually being added to by new galaxies with younger stars.
Date: October 19, 2006
Creator: Schiavon, Ricardo P.; Faber, S.M.; Konidaris, Nicholas; Graves,Genevieve; Willmer, Christopher N.A.; Weiner, Benjamin J. et al.
Object Type: Article
System: The UNT Digital Library
Obtaining the Bidirectional Transfer Distribution Function ofIsotropically Scattering Materials Using an Integrating Sphere (open access)

Obtaining the Bidirectional Transfer Distribution Function ofIsotropically Scattering Materials Using an Integrating Sphere

This paper demonstrates a method to determine thebidirectional transfer distribution function (BTDF) using an integratingsphere. Information about the sample's angle dependent scattering isobtained by making transmittance measurements with the sample atdifferent distances from the integrating sphere. Knowledge about theilluminated area of the sample and the geometry of the sphere port incombination with the measured data combines to an system of equationsthat includes the angle dependent transmittance. The resulting system ofequations is an ill-posed problem which rarely gives a physical solution.A solvable system is obtained by using Tikhonov regularization on theill-posed problem. The solution to this system can then be used to obtainthe BTDF. Four bulk-scattering samples were characterised using both twogoniophotometers and the described method to verify the validity of thenew method. The agreement shown is great for the more diffuse samples.The solution to the low-scattering samples contains unphysicaloscillations, butstill gives the correct shape of the solution. Theorigin of the oscillations and why they are more prominent inlow-scattering samples are discussed.
Date: October 19, 2006
Creator: Jonsson, Jacob C. & Branden, Henrik
Object Type: Article
System: The UNT Digital Library
First-principles calculation of mechanical properties of Si <001> nanowires and comparison to nanomechanical theory (open access)

First-principles calculation of mechanical properties of Si <001> nanowires and comparison to nanomechanical theory

We report the results of first-principles density functional theory calculations of the Young's modulus and other mechanical properties of hydrogen-passivated Si {l_angle}001{r_angle} nanowires. The nanowires are taken to have predominantly {l_brace}100{r_brace}surfaces, with small {l_brace}110{r_brace} facets according to the Wulff shape. The Young's modulus, the equilibrium length and the constrained residual stress of a series of prismatic beams of differing sizes are found to have size dependences that scale like the surface area to volume ratio for all but the smallest beam. The results are compared with a continuum model and the results of classical atomistic calculations based on an empirical potential. We attribute the size dependence to specific physical structures and interactions. In particular, the hydrogen interactions on the surface and the charge density variations within the beam are quantified and used both to parameterize the continuum model and to account for the discrepancies between the two models and the first-principles results.
Date: October 19, 2006
Creator: Lee, B & Rudd, R E
Object Type: Article
System: The UNT Digital Library
The BlueGene/L Supercomputer and Quantum ChromoDynamics (open access)

The BlueGene/L Supercomputer and Quantum ChromoDynamics

In summary our update contains: (1) Perfect speedup sustaining 19.3% of peak for the Wilson D D-slash Dirac operator. (2) Measurements of the full Conjugate Gradient (CG) inverter that inverts the Dirac operator. The CG inverter contains two global sums over the entire machine. Nevertheless, our measurements retain perfect speedup scaling demonstrating the robustness of our methods. (3) We ran on the largest BG/L system, the LLNL 64 rack BG/L supercomputer, and obtained a sustained speed of 59.1 TFlops. Furthermore, the speedup scaling of the Dirac operator and of the CG inverter are perfect all the way up to the full size of the machine, 131,072 cores (please see Figure II). The local lattice is rather small (4 x 4 x 4 x 16) while the total lattice has been a lattice QCD vision for thermodynamic studies (a total of 128 x 128 x 256 x 32 lattice sites). This speed is about five times larger compared to the speed we quoted in our submission. As we have pointed out in our paper QCD is notoriously sensitive to network and memory latencies, has a relatively high communication to computation ratio which can not be overlapped in BGL in virtual node …
Date: October 19, 2006
Creator: Vranas, P. & Soltz, R.
Object Type: Report
System: The UNT Digital Library
Bioethical Biobanks: Three Concerns in Designing and Using Law Enforcement DNA Identification Databases (open access)

Bioethical Biobanks: Three Concerns in Designing and Using Law Enforcement DNA Identification Databases

Federal and state law enforcement authorities have amassed large collections of DNA samples and the identifying profiles derived from them. These databases help to identify the guilty and to exonerate the innocent, but as the databanks grow, so do fears about civil liberties. The research reported here discusses three legal and social policy issues that have been raised in regard to these biobanks—the choice of loci to type for identifying individuals, the indefinite retention of DNA samples, and the use of the DNA samples or the identifying profiles for research purposes. It also considers the possible value of the databases for research into the genetics of human behavior and the ethics of using them for this purpose. It rejects the broad claim that such research is inherently unethical but proposes procedures for ensuring that the value of the proposed research justifies any psychosocial or other risks to the subjects of the research.
Date: October 19, 2006
Creator: Kaye, D.H.
Object Type: Report
System: The UNT Digital Library
EPICS SCA CLIENTS ON THE .NET X64 PLATFORM (open access)

EPICS SCA CLIENTS ON THE .NET X64 PLATFORM

We have developed a .NET assembly, which we call SCA.NET,which we have been using for building EPICS based control roomapplications at the Advanced Light Source (ALS). In this paper we reporton our experiences building a 64-bit version of SCA.NET and theunderlying channel access libraries for Windows XP x64 (using a dual coreAMD Athlon CPU). We also report on our progress in building newaccelerator control applications for this environment.
Date: October 19, 2006
Creator: Timossi, Chris & Nishimura, Hiroshi
Object Type: Article
System: The UNT Digital Library
Analytical Scanning and Transmission Electron Microscopy of Laboratory Impacts on Stardust Aluminium Foils: Interpreting Impact Crater Morphology and the Composition of Impact Residues. (open access)

Analytical Scanning and Transmission Electron Microscopy of Laboratory Impacts on Stardust Aluminium Foils: Interpreting Impact Crater Morphology and the Composition of Impact Residues.

The known encounter velocity (6.1kms{sup -1}) between the Stardust spacecraft and the dust emanating from the nucleus of comet Wild 2 has allowed realistic simulation of dust collection in laboratory experiments designed to validate analytical methods for the interpretation of dust impacts on the aluminium foil components of the Stardust collector. In this report we present information on crater gross morphology, the pre-existing major and trace element composition of the foil, geometrical issues for energy dispersive X-ray analysis of the impact residues in scanning electron microscopes, and the modification of dust chemical composition during creation of impact craters as revealed by analytical transmission electron microscopy. Together, these observations help to underpin the interpretation of size, density and composition for particles impacted upon the Stardust aluminium foils.
Date: October 19, 2006
Creator: Kearsley, A T; Graham, G A; Burchell, M J; Cole, M J; Dai, Z R; Teslich, N et al.
Object Type: Article
System: The UNT Digital Library
MONO FOR CROSS-PLATFORM CONTROL SYSTEM ENVIRONMENT (open access)

MONO FOR CROSS-PLATFORM CONTROL SYSTEM ENVIRONMENT

Mono is an independent implementation of the .NET Frameworkby Novell that runs on multiple operating systems (including Windows,Linux and Macintosh) and allows any .NET compatible application to rununmodified. For instance Mono can run programs with graphical userinterfaces (GUI) developed with the C# language on Windows with VisualStudio (a full port of WinForm for Mono is in progress). We present theresults of tests we performed to evaluate the portability of our controlssystem .NET applications from MS Windows to Linux.
Date: October 19, 2006
Creator: Nishimura, Hiroshi & Timossi, Chris
Object Type: Article
System: The UNT Digital Library