2010 GRC VIBRATIONAL SPECTROSCOPY AUGUST 1 - AUGUST 6, 2010 (open access)

2010 GRC VIBRATIONAL SPECTROSCOPY AUGUST 1 - AUGUST 6, 2010

The Vibrational Spectroscopy conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear and multidimensional spectroscopies. The conference highlights the application of these techniques in chemistry, materials, biology, and medicine. The theory of molecular vibrational motion and its connection to spectroscopic signatures and chemical reaction dynamics is the third major theme of the meeting. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules and nanomaterials.
Date: August 6, 2010
Creator: Pate, Brooks
Object Type: Article
System: The UNT Digital Library
Sources and transport systems for low energy extreme of ion implantation (open access)

Sources and transport systems for low energy extreme of ion implantation

For the past seven years a joint research and development effort focusing on the design of steady state, intense ion sources has been in progress with the ultimate goal being to meet the two, energy extreme range needs of mega-electron-volt and 100's of electron-volt ion implanters. However, since the last Fortier is low energy ion implantation, focus of the endeavor has shifted to low energy ion implantation. For boron cluster source development, we started with molecular ions of decaborane (B{sub 10}H{sub 14}), octadecaborane (B{sub 18}H{sub 22}), and presently our focus is on carborane (C{sub 2}B{sub 10}H{sub 12}) ions developing methods for mitigating graphite deposition. Simultaneously, we are developing a pure boron ion source (without a working gas) that can form the basis for a novel, more efficient, plasma immersion source. Our Calutron-Berna ion source was converted into a universal source capable of switching between generating molecular phosphorous P{sub 4}{sup +}, high charge state ions, as well as other types of ions. Additionally, we have developed transport systems capable of transporting a very large variety of ion species, and simulations of a novel gasless/plasmaless ion beam deceleration method were also performed.
Date: June 6, 2010
Creator: Hershcovitch, A.; Batalin, V. A.; Bugaev, A. S.; Gushenets, V. I.; Alexeyenko, O.; Gurkova, E. et al.
Object Type: Article
System: The UNT Digital Library
Inclusive hadron distributions in p+p collisions from saturation models of HERA DIS data. (open access)

Inclusive hadron distributions in p+p collisions from saturation models of HERA DIS data.

Dipole models based on various saturation scenarios provide reasonable fits to small-x DIS inclusive, diffractive and exclusive data from HERA. Proton un-integrated gluon distributions extracted from such fits are employed in a k{sub {perpendicular}}-factorization framework to calculate inclusive gluon distributions at various energies. The n-particle multiplicity distribution predicted in the Glasma flux tube approach shows good agreement with data over a wide range of energies. Hadron inclusive transverse momentum distributions expressed in terms of the saturation scale demonstrate universal behavior over a wider kinematic range systematically with increasing center of mass energies.
Date: December 6, 2010
Creator: Tribedy, P. & Venugopalan, R.
Object Type: Article
System: The UNT Digital Library
MARS Flight Engineering Status (open access)

MARS Flight Engineering Status

The Multi-sensor Airborne Radiation Survey Flight Engineering project (MARS FE) has designed a high purity germanium (HPGe) crystal array for conducting a wide range of field measurements. In addition to the HPGe detector system, a platform-specific shock and vibration isolation system and environmental housing have been designed to support demonstration activities in a maritime environment on an Unmanned Surface Vehicle (USV). This report describes the status of the equipment as of the end of FY09.
Date: April 6, 2010
Creator: Fast, James E.; Dorow, Kevin E.; Morris, Scott J.; Thompson, Robert C. & Willett, Jesse A.
Object Type: Report
System: The UNT Digital Library
Splitting a C-O bond in dialkylethers with bis(1,2,4-tri-t-butylcyclopentadienyl) cerium-hydride does not occur by a sigma-bond metathesis pathway: a combined experimental and DFT computational study (open access)

Splitting a C-O bond in dialkylethers with bis(1,2,4-tri-t-butylcyclopentadienyl) cerium-hydride does not occur by a sigma-bond metathesis pathway: a combined experimental and DFT computational study

Addition of diethylether to [1,2,4(Me3C)3C5H2]2CeH, abbreviated Cp'2CeH, gives Cp'2CeOEt and ethane. Similarly, di-n-propyl- or di-n-butylether gives Cp'2Ce(O-n-Pr) and propane or Cp'2Ce(O-n-Bu) and butane, respectively. Using Cp'2CeD, the propane and butane contain deuterium predominantly in their methyl groups. Mechanisms, formulated on the basis of DFT computational studies, show that the reactions begin by an alpha or beta-CH activation with comparable activation barriers but only the beta-CH activation intermediate evolves into the alkoxide product and an olefin. The olefin then inserts into the Ce-H bond forming the alkyl derivative, Cp'2CeR, that eliminates alkane. The alpha-CH activation intermediate is in equilibrium with the starting reagents, Cp'2CeH and the ether, which accounts for the deuterium label in the methyl groups of the alkane. The one-step sigma-bond metathesis mechanism has a much higher activation barrier than either of the two-step mechanisms.
Date: April 6, 2010
Creator: Werkema, Evan; Yahia, Ahmed; Maron, Laurent; Eisenstein, Odile & Andersen, Richard
Object Type: Article
System: The UNT Digital Library
2010 ELECTRODEPOSITION GORDON RESEARCH CONFERENCE, AUGUST 1-6, 2010 (open access)

2010 ELECTRODEPOSITION GORDON RESEARCH CONFERENCE, AUGUST 1-6, 2010

The 2010 Gordon Conference on Electrodeposition will present cutting-edge research on electrodeposition with emphasis on (i) advances in basic science, (ii) developments in next-generation technologies, and (iii) new and emerging areas. The Conference will feature a wide range of topics, from atomic scale processes, nucleation and growth, thin film deposition, and electrocrystallization, to applications of electrodeposition in devices including microelectronics, solar energy, and power sources. The Conference will bring together investigators from a wide range of scientific disciplines, including chemical engineering, materials science and engineering, physics, and chemistry. The Conference will feature invited speakers at the forefront of the field, and a late-breaking news session that will provide the opportunity for graduate students, post-docs, and junior faculty to participate. The collegial atmosphere of this Conference, with scientific talks and poster sessions, as well as opportunities for informal gatherings in the afternoons and evenings, provides an avenue for scientists from different disciplines to discuss current issues and promotes cross-disciplinary collaborations in the various research areas represented. The Conference will be held at Colby-Sawyer College, located in the Mt. Kearsarge-Lake Sunapee Region of New Hampshire. The surrounding mountains, forests, and lakes provide a beautiful setting for this conference. The attendance is limited …
Date: August 6, 2010
Creator: Searson, Peter
Object Type: Article
System: The UNT Digital Library
Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel (open access)

Structure of Oxide Nanoparticles in Fe-16Cr MA/ODS Ferritic Steel

Oxide nanoparticles in Fe-16Cr ODS ferritic steel fabricated by mechanical alloying (MA) method have been examined using high-resolution transmission electron microscopy (HRTEM) techniques. A partial crystallization of oxide nanoparticles was frequently observed in as-fabricated ODS steel. The crystal structure of crystalline oxide particles is identified to be mainly Y{sub 4}Al{sub 2}O{sub 9} (YAM) with a monoclinic structure. Large nanoparticles with a diameter larger than 20 nm tend to be incoherent and have a nearly spherical shape, whereas small nanoparticles with a diameter smaller than 10 nm tend to be coherent or semi-coherent and have faceted boundaries. The oxide nanoparticles become fully crystallized after prolonged annealing at 900 C. These results lead us to propose a three-stage formation mechanism of oxide nanoparticles in MA/ODS steels.
Date: April 6, 2010
Creator: Hsiung, L; Fluss, M & Kimura, A
Object Type: Article
System: The UNT Digital Library
NLM Evidence-based Information at Your Fingertips - NBNA (open access)

NLM Evidence-based Information at Your Fingertips - NBNA

The workshop titled, National Library of Medicine: Evidence-based Information At Your Fingertips, is a computer training class designed to meet the needs of nurses who require access to information on specific medical topics and on the adverse health effects of exposure to hazardous substances. The Specialized Information Services Division of the National Library of Medicine (NLM) is sponsoring this workshop for the National Black Nurses Association to increase the awareness of health professionals of the availability and value of the free NLM medical, environmental health, and toxicology databases.
Date: August 6, 2010
Creator: Womble, R.
Object Type: Book
System: The UNT Digital Library
Distinguishing Patterns of Charge Order: Stripes or Checkerboards (open access)

Distinguishing Patterns of Charge Order: Stripes or Checkerboards

In two dimensions, quenched disorder always rounds transitions involving the breaking of spatial symmetries so, in practice, it can often be difficult to infer what form the symmetry breaking would take in the 'ideal,' zero disorder limit. We discuss methods of data analysis which can be useful for making such inferences, and apply them to the problem of determining whether the preferred order in the cuprates is 'stripes' or 'checkerboards.' In many cases we show that the experiments clearly indicate stripe order, while in others (where the observed correlation length is short), the answer is presently uncertain.
Date: April 6, 2010
Creator: Robertson, J.A.
Object Type: Article
System: The UNT Digital Library
Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions (open access)

Self-consistent solution for proximity effect and Josephson current in ballistic graphene SNS Josephson junctions

We use a tight-binding Bogoliubov-de Gennes (BdG) formalism to self-consistently calculate the proximity effect, Josephson current, and local density of states in ballistic graphene SNS Josephson junctions. Both short and long junctions, with respect to the superconducting coherence length, are considered, as well as different doping levels of the graphene. We show that self-consistency does not notably change the current-phase relationship derived earlier for short junctions using the non-selfconsistent Dirac-BdG formalism but predict a significantly increased critical current with a stronger junction length dependence. In addition, we show that in junctions with no Fermi level mismatch between the N and S regions superconductivity persists even in the longest junctions we can investigate, indicating a diverging Ginzburg-Landau superconducting coherence length in the normal region.
Date: April 6, 2010
Creator: Black-Schaffer, Annica M.
Object Type: Article
System: The UNT Digital Library
Myriad phases of the Checkerboard Hubbard Model (open access)

Myriad phases of the Checkerboard Hubbard Model

The zero-temperature phase diagram of the checkerboard Hubbard model is obtained in the solvable limit in which it consists of weakly coupled square plaquettes. As a function of the on-site Coulomb repulsion U and the density of holes per site, x, we demonstrate the existence of at least 16 distinct phases. For instance, at zero doping, the ground state is a novel d-wave Mott insulator (d-Mott), which is not adiabatically continuable to a band insulator; by doping the d-Mott state with holes, depending on the magnitude of U, it gives way to a d-wave superconducting state, a two-flavor spin-1/2 Fermi liquid (FL), or a spin-3/2 FL.
Date: April 6, 2010
Creator: Yao, Hong
Object Type: Article
System: The UNT Digital Library
Dynamical Layer Decoupling in a Stripe-ordered, High T_c Superconductor (open access)

Dynamical Layer Decoupling in a Stripe-ordered, High T_c Superconductor

In the stripe-ordered state of a strongly-correlated two-dimensional electronic system, under a set of special circumstances, the superconducting condensate, like the magnetic order, can occur at a non-zero wave-vector corresponding to a spatial period double that of the charge order. In this case, the Josephson coupling between near neighbor planes, especially in a crystal with the special structure of La{sub 2-x}Ba{sub x}CuO{sub 4}, vanishes identically. We propose that this is the underlying cause of the dynamical decoupling of the layers recently observed in transport measurements at x = 1/8.
Date: April 6, 2010
Creator: Berg, E.
Object Type: Article
System: The UNT Digital Library
Mesoscale Modeling of LX-17 Under Isentropic Compression (open access)

Mesoscale Modeling of LX-17 Under Isentropic Compression

Mesoscale simulations of LX-17 incorporating different equilibrium mixture models were used to investigate the unreacted equation-of-state (UEOS) of TATB. Candidate TATB UEOS were calculated using the equilibrium mixture models and benchmarked with mesoscale simulations of isentropic compression experiments (ICE). X-ray computed tomography (XRCT) data provided the basis for initializing the simulations with realistic microstructural details. Three equilibrium mixture models were used in this study. The single constituent with conservation equations (SCCE) model was based on a mass-fraction weighted specific volume and the conservation of mass, momentum, and energy. The single constituent equation-of-state (SCEOS) model was based on a mass-fraction weighted specific volume and the equation-of-state of the constituents. The kinetic energy averaging (KEA) model was based on a mass-fraction weighted particle velocity mixture rule and the conservation equations. The SCEOS model yielded the stiffest TATB EOS (0.121{micro} + 0.4958{micro}{sup 2} + 2.0473{micro}{sup 3}) and, when incorporated in mesoscale simulations of the ICE, demonstrated the best agreement with VISAR velocity data for both specimen thicknesses. The SCCE model yielded a relatively more compliant EOS (0.1999{micro}-0.6967{micro}{sup 2} + 4.9546{micro}{sup 3}) and the KEA model yielded the most compliant EOS (0.1999{micro}-0.6967{micro}{sup 2}+4.9546{micro}{sup 3}) of all the equilibrium mixture models. Mesoscale simulations with the …
Date: March 6, 2010
Creator: Springer, H K; Willey, T M; Friedman, G; Fried, L E; Vandersall, K S & Baer, M R
Object Type: Article
System: The UNT Digital Library
TANK 40 FINAL SB5 CHEMICAL CHARACTERIZATION RESULTS PRIOR TO NP ADDITION (open access)

TANK 40 FINAL SB5 CHEMICAL CHARACTERIZATION RESULTS PRIOR TO NP ADDITION

A sample of Sludge Batch 5 (SB5) was pulled from Tank 40 in order to obtain radionuclide inventory analyses necessary for compliance with the Waste Acceptance Product Specifications (WAPS). This sample was also analyzed for chemical composition including noble metals. Prior to radionuclide inventory analyses, a final sample of the H-canyon Np stream will be added to bound the Np addition anticipated for Tank 40. These analyses along with the WAPS radionuclide analyses will help define the composition of the sludge in Tank 40 that is currently being fed to DWPF as SB5. At the Savannah River National Laboratory (SRNL) the 3-L Tank 40 SB5 sample was transferred from the shipping container into a 4-L high density polyethylene vessel and solids allowed to settle overnight. Supernate was then siphoned off and circulated through the shipping container to complete the transfer of the sample. Following thorough mixing of the 3-L sample, a 239 g sub-sample was removed. This sub-sample was then utilized for all subsequent analytical samples. Eight separate aliquots of the slurry were digested, four with HNO{sub 3}/HCl (aqua regia) in sealed Teflon{reg_sign} vessels and four in Na{sub 2}O{sub 2} (alkali or peroxide fusion) using Zr crucibles. Due to the …
Date: January 6, 2010
Creator: Bannochie, C. & Click, D.
Object Type: Report
System: The UNT Digital Library
Theory of quantum metal to superconductor transitions in highly conducting systems (open access)

Theory of quantum metal to superconductor transitions in highly conducting systems

We derive the theory of the quantum (zero temperature) superconductor to metal transition in disordered materials when the resistance of the normal metal near criticality is small compared to the quantum of resistivity. This can occur most readily in situations in which 'Anderson's theorem' does not apply. We explicitly study the transition in superconductor-metal composites, in an swave superconducting film in the presence of a magnetic field, and in a low temperature disordered d-wave superconductor. Near the point of the transition, the distribution of the superconducting order parameter is highly inhomogeneous. To describe this situation we employ a procedure which is similar to that introduced by Mott for description of the temperature dependence of the variable range hopping conduction. As the system approaches the point of the transition from the metal to the superconductor, the conductivity of the system diverges, and the Wiedemann-Franz law is violated. In the case of d-wave (or other exotic) superconductors we predict the existence of (at least) two sequential transitions as a function of increasing disorder: a d-wave to s-wave, and then an s-wave to metal transition.
Date: April 6, 2010
Creator: Spivak, B.
Object Type: Article
System: The UNT Digital Library
Experience Report for WOPR (open access)

Experience Report for WOPR

One of the purposes of the SQA effort at LLNL is to attempt to determine the 'goodness' of the research codes used for various scientific applications. Typically these are two and three dimensional multi-physics simulation and modeling codes. These legacy research codes are used for applciations such as atmospheric dispersion modeling and analysis and prediction of the performance of engineered systems. These codes are continually subjected to automated regression test suites consisting of verified and validated expected results. Code is managed in repositories. Experience level of developers is high in the knowledge domain, platforms, and languages used. Code size of the multi-physics code used in this study was 578,242 lines excluding comment and blank lines or 5538.7 function points. Languages were 70% C++, 20% C, and 10% Fortran. The code has 130 users and a development team of 14 and an embedded SQE. The code has achieved 100% prime feature test coverage, 73.6% functional test coverage, and 71.5% statement test coverage. The average cyclomatic complexity of the code was 6.25. The codes have evolved over 10 years. Research codes are challenging because there is a desire to balance agility with discipline as well as compliance with DOE standards. Agility is …
Date: April 6, 2010
Creator: Pope, G
Object Type: Report
System: The UNT Digital Library
Layed Perovskite PRBA0.5SR0.5CO205 as High Performance Cathode for Solid Oxide Fuels Using Photon Conducting Electrolyte (open access)

Layed Perovskite PRBA0.5SR0.5CO205 as High Performance Cathode for Solid Oxide Fuels Using Photon Conducting Electrolyte

This paper discusses solid oxide fuel cells, proton conductors, layered perovskite and Cathodes.
Date: May 6, 2010
Creator: Brinkman, K.
Object Type: Article
System: The UNT Digital Library
The Need for a Strong Science and Technology Program in the Nuclear Weapons Complex for the 21st Century (open access)

The Need for a Strong Science and Technology Program in the Nuclear Weapons Complex for the 21st Century

In this paper I argue for the need for a strong Science and Technology program in the Nuclear Weapons Complex as the basis for maintaining a credible deterrence capability. The current Nuclear Posture Review establishes a New Triad as the basis for the United States deterrence strategy in a changing security environment. A predictive science capability is at the core of a credible National Nuclear Weapons program in the 21st Century. In absence of nuclear testing, the certification of our current Nuclear Weapons relies on predictive simulations and quantification of the associated simulation uncertainties. In addition, a robust nuclear infrastructure needs an active research and development program that considers all the required nuclear scenarios, including new configurations for which there is no nuclear test data. This paper also considers alternative positions to the need for a Science and Technology program in the Nuclear Weapons complex.
Date: January 6, 2010
Creator: Garaizar, X
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Using Quasi-Monoenergetic Photon Sources to Probe Photo-Fission Resonances (open access)

Using Quasi-Monoenergetic Photon Sources to Probe Photo-Fission Resonances

None
Date: August 6, 2010
Creator: Johnson, M. S.; Hall, J. M.; McNabb, D. P.; Tuffley, M.; Ahmed, M.; Stave, S. et al.
Object Type: Article
System: The UNT Digital Library
Superconductivity in Inhomogeneous Hubbard Models (open access)

Superconductivity in Inhomogeneous Hubbard Models

None
Date: April 6, 2010
Creator: Tsai, W-F.
Object Type: Article
System: The UNT Digital Library
LAND AND WATER USE CHARACTERISTICS AND HUMAN HEALTH INPUT PARAMETERS FOR USE IN ENVIRONMENTAL DOSIMETRY AND RISK ASSESSMENTS AT THE SAVANNAH RIVER SITE (open access)

LAND AND WATER USE CHARACTERISTICS AND HUMAN HEALTH INPUT PARAMETERS FOR USE IN ENVIRONMENTAL DOSIMETRY AND RISK ASSESSMENTS AT THE SAVANNAH RIVER SITE

Operations at the Savannah River Site (SRS) result in releases of small amounts of radioactive materials to the atmosphere and to the Savannah River. For regulatory compliance purposes, potential offsite radiological doses are estimated annually using computer models that follow U.S. Nuclear Regulatory Commission (NRC) Regulatory Guides. Within the regulatory guides, default values are provided for many of the dose model parameters but the use of site-specific values by the applicant is encouraged. A detailed survey of land and water use parameters was conducted in 1991 and is being updated here. These parameters include local characteristics of meat, milk and vegetable production; river recreational activities; and meat, milk and vegetable consumption rates as well as other human usage parameters required in the SRS dosimetry models. In addition, the preferred elemental bioaccumulation factors and transfer factors to be used in human health exposure calculations at SRS are documented. Based on comparisons to the 2009 SRS environmental compliance doses, the following effects are expected in future SRS compliance dose calculations: (1) Aquatic all-pathway maximally exposed individual doses may go up about 10 percent due to changes in the aquatic bioaccumulation factors; (2) Aquatic all-pathway collective doses may go up about 5 percent …
Date: August 6, 2010
Creator: Jannik, T.; Karapatakis, D.; Lee, P. & Farfan, E.
Object Type: Report
System: The UNT Digital Library
Benefits and Costs of Aggressive Energy Efficiency Programs and the Impacts of Alternative Sources of Funding: Case Study of Massachusetts (open access)

Benefits and Costs of Aggressive Energy Efficiency Programs and the Impacts of Alternative Sources of Funding: Case Study of Massachusetts

Increased interest by state (and federal) policymakers and regulatory agencies in pursuing aggressive energy efficiency efforts could deliver significant utility bill savings for customers while having long-term implications for ratepayers (e.g. potential rate impacts). Equity and distributional concerns associated with the authorized recovery of energy efficiency program costs may necessitate the pursuit of alternative program funding approaches. In 2008, Massachusetts passed the Green Communities Act which directed its energy efficiency (EE) program administrators to obtain all cost-effective EE resources. This goal has translated into achieving annual electric energy savings equivalent to a 2.4% reduction in retail sales from energy efficiency programs in 2012. Representatives of electricity consumer groups supported the new portfolio of EE programs (and the projected bill savings) but raised concerns about the potential rate impacts associated with achieving such aggressive EE goals, leading policymakers to seek out alternative funding sources which can potentially mitigate these effects. Utility administrators have also raised concerns about under-recovery of fixed costs when aggressive energy efficiency programs are pursued and have proposed ratemaking policies (e.g. decoupling) and business models that better align the utility's financial interests with the state's energy efficiency public policy goals. Quantifying these concerns and identifying ways they can …
Date: August 6, 2010
Creator: Cappers, Peter; Satchwell, Andrew; Goldman, Charles & Schlegel, Jeff
Object Type: Report
System: The UNT Digital Library
Collaborative research on amine borane regeneration and market analysis of hydrogen storage materials. (open access)

Collaborative research on amine borane regeneration and market analysis of hydrogen storage materials.

This report describes Collaborative research on amine borane regeneration and market analysis of hydrogen storage materials.
Date: December 6, 2010
Creator: Schubert, David
Object Type: Report
System: The UNT Digital Library
Development of Characterization Technology for Fault Zone Hydrology (open access)

Development of Characterization Technology for Fault Zone Hydrology

Several deep trenches were cut, and a number of geophysical surveys were conducted across the Wildcat Fault in the hills east of Berkeley, California. The Wildcat Fault is believed to be a strike-slip fault and a member of the Hayward Fault System, with over 10 km of displacement. So far, three boreholes of ~;; 150m deep have been core-drilled and borehole geophysical logs were conducted. The rocks are extensively sheared and fractured; gouges were observed at several depths and a thick cataclasitic zone was also observed. While confirming some earlier, published conclusions from shallow observations about Wildcat, some unexpected findings were encountered. Preliminary analysis indicates that Wildcat near the field site consists of multiple faults. The hydraulic test data suggest the dual properties of the hydrologic structure of the fault zone. A fourth borehole is planned to penetrate the main fault believed to lie in-between the holes. The main philosophy behind our approach for the hydrologic characterization of such a complex fractured system is to let the system take its own average and monitor a long term behavior instead of collecting a multitude of data at small length and time scales, or at a discrete fracture scale and to ?up-scale,? …
Date: August 6, 2010
Creator: Karasaki, Kenzi; Onishi, Tiemi; Gasperikova, Erika; Goto, Junichi; Tsuchi, Hiroyuki; Miwa, Tadashi et al.
Object Type: Article
System: The UNT Digital Library