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Calculations Predict a Large Inverse H/D Kinetic Isotope Effect on the Rate of Tunneling in the Ring Opening of Cyclopropylcarbinyl Radical (open access)

Calculations Predict a Large Inverse H/D Kinetic Isotope Effect on the Rate of Tunneling in the Ring Opening of Cyclopropylcarbinyl Radical

Article on calculations predicting a large inverse H/D kinetic isotope effect on the rate of tunneling in the ring opening of cyclopropylcarbinyl radical.
Date: October 15, 2009
Creator: Zhang, Xue; Datta, Ayan; Hrovat, David A. & Borden, Weston T.
System: The UNT Digital Library
Quality Health Information on the Internet: Developing a Diabetes Pathfinder for the Chinese Population (open access)

Quality Health Information on the Internet: Developing a Diabetes Pathfinder for the Chinese Population

A Web-based bilingual diabetes information pathfinder was created to help the Chinese population access quality health information on the Internet as part of a collaborative outreach project in the Dallas-Fort Worth area.
Date: October 1, 2009
Creator: Cleveland, Ana D., 1943-; Philbrick, Jodi; Pan, Xuequn (Della); Yu, Xinyu; Chen, Jiangping; O'Neill, Marty et al.
System: The UNT Digital Library
Activation of Carbon-Hydrogen and Hydrogen-Hydrogen Bonds by Copper-Nitrenes: A Comparison of Density Functionality Theory with Single- and Multireference Correlation Consistent Composite Approaches (open access)

Activation of Carbon-Hydrogen and Hydrogen-Hydrogen Bonds by Copper-Nitrenes: A Comparison of Density Functionality Theory with Single- and Multireference Correlation Consistent Composite Approaches

Article on a comparison of density functional theory with single- and multireference correlation consistent composite approaches (ccCA).
Date: October 19, 2009
Creator: Tekarli, Sammer M.; Williams, T. Gavin & Cundari, Thomas R., 1964-
System: The UNT Digital Library
Comparison of Strategies and Policies for Building Distributed Digital Preservation Infrastructure: Initial Findings from the MetaArchive Cooperative (open access)

Comparison of Strategies and Policies for Building Distributed Digital Preservation Infrastructure: Initial Findings from the MetaArchive Cooperative

This article offers a comparison of strategies and policies for building distributed digital preservation infrastructure.
Date: October 15, 2009
Creator: Halbert, Martin
System: The UNT Digital Library
Solubility of 5-(2-Chlorophenyl)-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one, 7-Chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepin-2-one, and 6-(2,3-Dichlorophenyl)-1,2,4-triazine-3,5-diamine in the Mixtures of Poly(ethylene glycol) 600, Ethanol, and Water at a Temperature of 298.2 K (open access)

Solubility of 5-(2-Chlorophenyl)-7-nitro-1,3-dihydro-1,4-benzodiazepin-2-one, 7-Chloro-1-methyl-5-phenyl-3H-1,4-benzodiazepin-2-one, and 6-(2,3-Dichlorophenyl)-1,2,4-triazine-3,5-diamine in the Mixtures of Poly(ethylene glycol) 600, Ethanol, and Water at a Temperature of 298.2 K

Article on the solubility of 5-(2-chlorophenyl)-7-nitro-1, 3-dihydro-1, 4-benzodiazepin-2-one, 7-chloro-1-methyl-5-phenyl-3H-1, 4-benzodiazepin-2-one, and 6-(2,3-dichlorophenyl)-1, 2, 4,-triazine-3, 5-diamine in the mixtures of poly(ethylene glycol) 600, ethanol, and water at temperature of 298.2 K.
Date: October 23, 2009
Creator: Soltanpour, Shahla; Acree, William E. (William Eugene) & Jouyban, Abolghasem
System: The UNT Digital Library
First-principles investigations of the dielectric properties of polypropylene/metal-oxide interfaces (open access)

First-principles investigations of the dielectric properties of polypropylene/metal-oxide interfaces

Article on first-principles investigations of the dielectric properties of polypropylene/metal-oxide interfaces. Nanoscale-resolved dielectric properties of polypropylene/metal-oxide (alumina, PbTiO₃) interfaces and of the corresponding surfaces are investigated via first-principles calculations.
Date: October 30, 2009
Creator: Yu, Liping; Ranjan, Vivek; Buongiorno Nardelli, Marco & Bernholc, Jerry
System: The UNT Digital Library
The Use of Videophones for Patient and Family Participation in Hospice Interdisciplinary Team Meetings: A Promising Approach (open access)

The Use of Videophones for Patient and Family Participation in Hospice Interdisciplinary Team Meetings: A Promising Approach

Article on the use of videophones for patient and family participation in hospice interdisciplinary team meetings.
Date: October 14, 2009
Creator: Oliver, Debra Parker; Demiris, George; Wittenberg-Lyles, Elaine & Porock, Davina, Ph. D.
System: The UNT Digital Library
Solubility of Pioglitazone Hydrochloride in Aqueous Solutions of Ethanol, Propylene Glycol, and N-Methyl-2-Pyrrolidone at 298.2°K (open access)

Solubility of Pioglitazone Hydrochloride in Aqueous Solutions of Ethanol, Propylene Glycol, and N-Methyl-2-Pyrrolidone at 298.2°K

Article on the solubility of pioglitazone hydrochloride in aqueous solutions of ethanol, propylene glycol, and n-methyl-2-pyrrolidone at 298°K.
Date: October 16, 2009
Creator: Soltanpour, Shahla; Acree, William E. (William Eugene) & Jouyban, Abolghasem
System: The UNT Digital Library
It's not too Late for the Harpy Eagle (Harpia harpyja): High Levels of Genetic Diversity and Differentiation Can Fuel Conservation Programs (open access)

It's not too Late for the Harpy Eagle (Harpia harpyja): High Levels of Genetic Diversity and Differentiation Can Fuel Conservation Programs

Article on the harpy eagle (Harpia harpyja) and how high levels of genetic diversity and differentiation can fuel conservation programs.
Date: October 5, 2009
Creator: Lerner, Heather R. L.; Johnson, Jeff A.; Lindsay, Alec R.; Kiff, Lloyd F. & Mindell, David P.
System: The UNT Digital Library
Analysis of Auditory Measures in Normal Hearing Young Male Adult Cigarette Smokers Using Multiple Variable Selection Methods with Predictive Validation Assessments (open access)

Analysis of Auditory Measures in Normal Hearing Young Male Adult Cigarette Smokers Using Multiple Variable Selection Methods with Predictive Validation Assessments

Article on an analysis of auditory measures in normal hearing young male adult cigarette smokers using multiple variable selection methods with predictive validation assessments.
Date: October 25, 2009
Creator: Gopal, Kamakshi V.; Herrington, Richard & Pearce, Jacquelin
System: The UNT Digital Library
Scaling to 150K cores: recent algorithm and performance engineering developments enabling XGC1 to run at scale (open access)

Scaling to 150K cores: recent algorithm and performance engineering developments enabling XGC1 to run at scale

Particle-in-cell (PIC) methods have proven to be eft#11;ective in discretizing the Vlasov-Maxwell system of equations describing the core of toroidal burning plasmas for many decades. Recent physical understanding of the importance of edge physics for stability and transport in tokamaks has lead to development of the fi#12;rst fully toroidal edge PIC code - XGC1. The edge region poses special problems in meshing for PIC methods due to the lack of closed flux surfaces, which makes fi#12;eld-line following meshes and coordinate systems problematic. We present a solution to this problem with a semi-#12;field line following mesh method in a cylindrical coordinate system. Additionally, modern supercomputers require highly concurrent algorithms and implementations, with all levels of the memory hierarchy being effe#14;ciently utilized to realize optimal code performance. This paper presents a mesh and particle partitioning method, suitable to our meshing strategy, for use on highly concurrent cache-based computing platforms.
Date: October 1, 2009
Creator: Adams, Mark F.; Ku, Seung-Hoe; Worley, Patrick; D'Azevedo, Ed; Cummings, Julian C. & Chang, C. S.
System: The UNT Digital Library
Challenges and opportunities in high-precision Be-10 measurements at CAMS (open access)

Challenges and opportunities in high-precision Be-10 measurements at CAMS

None
Date: October 12, 2009
Creator: Rood, D. H.; Hall, S.; Guilderson, T. P.; Finkel, R. C. & Brown, T. A.
System: The UNT Digital Library
On-demand Overlay Networks for Large Scientific Data Transfers (open access)

On-demand Overlay Networks for Large Scientific Data Transfers

Large scale scientific data transfers are central to scientific processes. Data from large experimental facilities have to be moved to local institutions for analysis or often data needs to be moved between local clusters and large supercomputing centers. In this paper, we propose and evaluate a network overlay architecture to enable highthroughput, on-demand, coordinated data transfers over wide-area networks. Our work leverages Phoebus and On-demand Secure Circuits and AdvanceReservation System (OSCARS) to provide high performance wide-area network connections. OSCARS enables dynamic provisioning of network paths with guaranteed bandwidth and Phoebus enables the coordination and effective utilization of the OSCARS network paths. Our evaluation shows that this approach leads to improved end-to-end data transfer throughput with minimal overheads. The achievedthroughput using our overlay was limited only by the ability of the end hosts to sink the data.
Date: October 12, 2009
Creator: Ramakrishnan, Lavanya; Guok, Chin; Jackson, Keith; Kissel, Ezra; Swany, D. Martin & Agarwal, Deborah
System: The UNT Digital Library
Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions (open access)

Directional Stand-off Detection of Fast Neutrons and Gammas Using Angular Scattering Distributions

We have investigated the response of a DoubleScatter Neutron Spectrometer (DSNS) for sources at long distances (gr than 200 meters). We find that an alternative method for analyzing double scatter data avoids some uncertainties introduced by amplitude measurements in plastic scintillators.Time of flight is used to discriminate between gamma and neutron events, and the kinematic distributions of scattering angles are assumed to apply. Non-relativistic neutrons are most likely to scatter at 45°, while gammas with energies greater than 2 MeV are most likely to be forward scattered. The distribution of scattering angles of fission neutrons arriving from a distant point source generates a 45° cone, which can be back-projected to give the source direction. At the same time, the distribution of Compton-scattered gammas has a maximum in the forward direction, and can be made narrower by selecting events that deposit minimal energy in the first scattering event. We have further determined that the shape of spontaneous fission neutron spectra at ranges gr than 110 m is still significantly different from thecosmic ray background.
Date: October 25, 2009
Creator: Vanier, Peter E.; Dioszegi, Istvan; Salwen, Ccynthia & Forman, Leon
System: The UNT Digital Library
Calculating the Loss factor of the LCLS Beam Line Elements for Ultra-Shrot Bunches (open access)

Calculating the Loss factor of the LCLS Beam Line Elements for Ultra-Shrot Bunches

The Linac Coherent Light Source (LCLS) is a SASE 1.5-15 {angstrom} x-ray Free-Electron Laser (FEL) facility. Since an ultra-short intense bunch is used in the LCLS operation one might suggest that wake fields, generated in the vacuum chamber, may have an effect on the x-ray production because these fields can change the beam particle energies thereby increasing the energy spread in a bunch. At LCLS a feedback system precisely controls the bunch energy before it enters a beam transport line after the linac. However, in the transport line and later in the undulator section the bunch energy and energy spread are not under feedback control and may change due to wake field radiation, which depends upon the bunch current or on a bunch length. The linear part of the energy spread can be compensated in the upstream linac; the energy loss in the undulator section can be compensated by varying the K-parameter of the undulators, however we need a precise knowledge of the wake fields in this part of the machine. Resistive wake fields are known and well calculated. We discuss an additional part of the wake fields, which comes from the different vacuum elements like bellows, BPMs, transitions, vacuum …
Date: October 17, 2009
Creator: Novokhatski, A.
System: The UNT Digital Library
The application of a figure of merit for nuclear explosive utility as metric for material attractiveness in a nuclear material theft scenario (open access)

The application of a figure of merit for nuclear explosive utility as metric for material attractiveness in a nuclear material theft scenario

None
Date: October 6, 2009
Creator: King, Wayne; Bradley, Keith; Jones, Ed; Kramer, Kevin J.; Latkowski, Jeff; Robel, Martin et al.
System: The UNT Digital Library
Recent Test Results of the High Field Nb3Sn Dipole Magnet HD2 (open access)

Recent Test Results of the High Field Nb3Sn Dipole Magnet HD2

The 1 m long Nb{sub 3}Sn dipole magnet HD2, fabricated and tested at Lawrence Berkeley National Laboratory, represents a step towards the development of block-type accelerator quality magnets operating in the range of 13-15 T. The magnet design features two coil modules composed of two layers wound around a titanium-alloy pole. The layer 1 pole includes a round cutout to provide room for a bore tube with a clear aperture of 36 mm. After a first series of tests where HD2 reached a maximum bore field of 13.8 T, corresponding to an estimated peak field on the conductor of 14.5 T, the magnet was disassembled and reloaded without the bore tube and with a clear aperture increased to 43 mm. We describe in this paper the magnet training observed in two consecutive tests after the removal of the bore tube, with a comparison of the quench performance with respect to the previous tests. An analysis of the voltage signals recorded before and after training quenches is then presented and discussed, and the results of coil visual inspections reported.
Date: October 19, 2009
Creator: Ferracin, P.; Bingham, B.; Caspi, S.; Cheng, D. W.; Dietderich, D. R.; Felice, H. et al.
System: The UNT Digital Library
Jefferson Lab IEC 61508/61511 Safety PLC Based Safety System (open access)

Jefferson Lab IEC 61508/61511 Safety PLC Based Safety System

This paper describes the design of the new 12 GeV Upgrade Personnel Safety System (PSS) at the Thomas Jefferson National Accelerator Facility (TJNAF). The new PSS design is based on the implementation of systems designed to meet international standards IEC61508 and IEC 61511 for programmable safety systems. In order to meet the IEC standards, TJNAF engineers evaluated several SIL 3 Safety PLCs before deciding on an optimal architecture. In addition to hardware considerations, software quality standards and practices must also be considered. Finally, we will discuss R&D that may lead to both high safety reliability and high machine availability that may be applicable to future accelerators such as the ILC. Key words: PLC, Safety, TJNAF, SIL, PSS, PPS, Software, ILC Notice: Authored by Jefferson Science Associates, LLC under U.S. DOE Contract No. DE-AC05-06OR23177. The U.S. Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce this manuscript for U.S. Government purposes.
Date: October 1, 2009
Creator: Kelly Mahoney, Henry Robertson
System: The UNT Digital Library
Integrated process modeling for the laser inertial fusion Energy (LIFE) generation system (open access)

Integrated process modeling for the laser inertial fusion Energy (LIFE) generation system

A concept for a new fusion-fission hybrid technology is being developed at Lawrence Livermore National Laboratory. The primary application of this technology is base-load electrical power generation. However, variants of the baseline technology can be used to 'burn' spent nuclear fuel from light water reactors or to perform selective transmutation of problematic fission products. The use of a fusion driver allows very high burn-up of the fission fuel, limited only by the radiation resistance of the fuel form and system structures. As a part of this process, integrated process models have been developed to aid in concept definition. Several models have been developed. A cost scaling model allows quick assessment of design changes or technology improvements on cost of electricity. System design models are being used to better understand system interactions and to do design trade-off and optimization studies. Here we describe the different systems models and present systems analysis results. Different market entry strategies are discussed along with potential benefits to US energy security and nuclear waste disposal. Advanced technology options are evaluated and potential benefits from additional R&D targeted at the different options is quantified.
Date: October 22, 2009
Creator: Meier, W. R.; Anklam, T. M.; Erlandson, A. C.; Miles, R. R.; Simon, A. J.; Sawicki, R. et al.
System: The UNT Digital Library
AAAR 28th Annual Conference Symposia Focusing on Topics of Interest to the U.S. DOE Atmospheric Science Program - October 26-30, 2009 (open access)

AAAR 28th Annual Conference Symposia Focusing on Topics of Interest to the U.S. DOE Atmospheric Science Program - October 26-30, 2009

This report addresses the secondary aerosol is an important component of atmospheric fine particles that generally consists of organics, sulfates, and nitrates.
Date: October 26, 2009
Creator: Ziemann, Paul
System: The UNT Digital Library
Hot Electron Generation and Transport Using K(alpha) Emission (open access)

Hot Electron Generation and Transport Using K(alpha) Emission

We have conducted experiments on both the Vulcan and Titan laser facilities to study hot electron generation and transport in the context of fast ignition. Cu wires attached to Al cones were used to investigate the effect on coupling efficiency of plasma surround and the pre-formed plasma inside the cone. We found that with thin cones 15% of laser energy is coupled to the 40{micro}m diameter wire emulating a 40{micro}m fast ignition spot. Thick cone walls, simulating plasma in fast ignition, reduce coupling by x4. An increase of prepulse level inside the cone by a factor of 50 reduces coupling by a factor of 3.
Date: October 15, 2009
Creator: Akli, K. U.; Stephens, R. B.; Key, M. H.; Bartal, T.; Beg, F. N.; Chawla, S. et al.
System: The UNT Digital Library
Gene Expression in the Third Dimension: The ECM-nucleus Connection (open access)

Gene Expression in the Third Dimension: The ECM-nucleus Connection

Decades ago, we and others proposed that the dynamic interplay between a cell and its surrounding environment dictates cell phenotype and tissue structure. Whereas much has been discovered about the effects of extracellular matrix molecules on cell growth and tissue specific gene expression, the nuclear mechanisms through which these molecules promote these physiological events remain unknown. Using mammary epithelial cells as a model, the purpose of this review is to discuss how the extracellular matrix influences nuclear structure and function in a three-dimensional context to promote epithelial morphogenesis and function in the mammary gland.
Date: October 1, 2009
Creator: Spencer, Virginia A; Xu, Ren & Bissell, Mina
System: The UNT Digital Library
New Beam Loss Monitor for 12 GeV Upgrade (open access)

New Beam Loss Monitor for 12 GeV Upgrade

This paper describes a new VME based machine protection Beam Loss Monitor (BLM) signal processing board designed at Jefferson Lab to replace the current CAMAC based BLM board. The new eight-channel BLM signal processor has linear, logarithmic, and integrating amplifiers that simultaneously provide the optimal signal processing for each application. Amplified signals are digitized and then further processed through a Field Programmable Gate Array (FPGA). Combining both the diagnostic and machine protection functions in each channel allows the operator to tune-up and monitor beam operations while the machine protection is integrating the same signal. Other features include extensive built-in-self-test, fast shutdown interface (FSD), and 16-Mbit buffers for beam loss transient play-back. The new VME BLM board features high sensitivity, high resolution, and low cost per channel.
Date: October 1, 2009
Creator: Jianxun Yan, Kelly Mahoney
System: The UNT Digital Library
Fast Ignition Transport Simulations for NIF (open access)

Fast Ignition Transport Simulations for NIF

This paper shows work at Lawrence Livermore National Lab (LLNL) devoted to modeling the propagation of, and heating by, a relativistic electron beam in a idealized dense fuel assembly for fast ignition. The implicit particle-in-cell (PIC) code LSP is used. Experiments planned on the National Ignition Facility (NIF) in the next few years using the Advanced Radiography Capability (ARC) short-pulse laser motivate this work. We demonstrate significant improvement in the heating of dense fuel due to magnetic forces, increased beam collimation, and insertion of a finite-radius carbon region between the beam excitation and fuel regions.
Date: October 5, 2009
Creator: Strozzi, D J; Grote, D P; Tabak, M; Cohen, B I; Town, R P & Kemp, A J
System: The UNT Digital Library