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Gaining analytic control of parton showers

Description: Parton showers are widely used to generate fully exclusive final states needed to compare theoretical models to experimental observations. While, in general, parton showers give a good description of the experimental data, the precise functional form of the probability distribution underlying the event generation is generally not known. The reason is that realistic parton showers are required to conserve four-momentum at each vertex. In this paper we investigate in detail how four-momentum cons… more
Date: May 14, 2007
Creator: Tackmann, Frank; Bauer, Christian W. & Tackmann, Frank J.
Partner: UNT Libraries Government Documents Department
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Geometry of non-supersymmetric three-charge bound states

Description: We study the smooth non-supersymmetric three-charge microstatesof Jejjala, Madden, Ross and Titchener using Kaluza-Klein reductions of the solutions to five and four dimensions. Our aim is to improve our understanding of the relation between these non-supersymmetric solutions and the well-studied supersymmetric cases. We find some surprising qualitative differences. In the five-dimensional description, the solution has orbifold fixed points which break supersymmetry locally, so the geometries c… more
Date: May 14, 2007
Creator: Gimon, Eric G.; Levi, Thomas S. & Ross, Simon F.
Partner: UNT Libraries Government Documents Department
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Molecular analysis of the gut microbiota of identical twins with Crohn's disease

Description: Increasing evidence suggests that a combination of host genetics and the composition of the gut microbiota are important for development of Crohn's disease (CD). Our aim was to study identical twins with CD to determine microbial factors independently of host genetics. Fecal samples were studied from 10 monozygotic twin pairs with CD (discordant n=6, concordant n=4) and 8 healthy twin pairs. DNA was extracted, 16S rRNA genes were PCR amplified and T-RFLP fingerprints generated using general bac… more
Date: March 14, 2008
Creator: Jansson, Janet; Dicksved, Johan; Halfvarson, Jonas; Rosenquist, Magnus; Jarnerot, Gunnar; Tysk, Curt et al.
Partner: UNT Libraries Government Documents Department
open access

The Performance Effect of Multi-core on ScientificApplications

Description: The historical trend of increasing single CPU performancehas given way to roadmap of increasing core count. The challenge ofeffectively utilizing these multi-core chips is just starting to beexplored by vendors and application developers alike. In this study, wepresent some performance measurements of several complete scientificapplications on single and dual core Cray XT3 and XT4 systems with a viewto characterizing the effects of switching to multi-core chips. Weconsider effects within a node… more
Date: May 14, 2007
Creator: Carter, Jonathan; He, Yun; Shalf, John; Shan, Hongzhang; Strohmaier, Erich & Wasserman, Harvey
Partner: UNT Libraries Government Documents Department
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A Coupled Model for Natural Convection and Condensation in HeatedSubsurface Enclosures Embedded in Fractured Rock

Description: In heated tunnels such as those designated for emplacementof radioactive waste at Yucca Mountain, axial temperature gradients maycause natural convection processes that can significantly influence themoisture conditions in the tunnels and in the surrounding fractured rock.Large-scale convection cells would provide an effective mechanism foraxial vapor transport, driving moisture out of the formation away fromthe heated tunnel section into cool end sections (where no waste isemplaced). To study … more
Date: April 14, 2006
Creator: Halecky, N.; Birkholzer, J. T.; Webb, S. W.; Peterson, P. F. & Bodvarsson, G. S.
Partner: UNT Libraries Government Documents Department
open access

THE PHOTOCHEMISTRY OF PYRIDINE N-OXIDE

Description: The authors wish to report their results on the photolysis of pyridine N-oxide in alcoholic solution. Both methanol and ethanol solutions of pyridine N-oxide were irradiated. The reaction mixture was analyzed by gas-liquid chromatography (GLC) using a 2.5% FFAP on Chrom G column and a Porapak Q column. In order to collect the products, the volume of the photolysis solution was reduced in vacuo and the resulting mixture was separated by preparative GLC.
Date: September 14, 1967
Creator: Alkaitis, Algis & Calvin, Melvin.
Partner: UNT Libraries Government Documents Department
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Analysis of cause and mechanism for injection-induced seismicityat the Geysers Geothermal Field, California

Description: We analyzed relative contributions to the cause andmechanism of injection-induced seismicity at The Geysers geothermalfield, California, using coupled thermal-hydrological-mechanicalmodeling. Our analysis shows that the most important cause forinjection-induced seismicity is injection-induced cooling and associatedthermal-elastic shrinkage that changes the stress state in such a waythat mechanical failure and seismicity can be induced. Specifically, thecooling shrinkage results in unloading and… more
Date: June 14, 2007
Creator: Rutqvist, Jonny & Oldenburg, Curtis
Partner: UNT Libraries Government Documents Department
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Germanium: From Its Discovery to SiGe Devices

Description: Germanium, element No.32, was discovered in 1886 by Clemens Winkler. Its first broad application was in the form of point contact Schottky diodes for radar reception during WWII. The addition of a closely spaced second contact led to the first all-solid-state electronic amplifier device, the transistor. The relatively low bandgap, the lack of a stable oxide and large surface state densities relegated germanium to the number 2 position behind silicon. The discovery of the lithium drift process, … more
Date: June 14, 2006
Creator: Haller, E.E.
Partner: UNT Libraries Government Documents Department
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Task Group 7B: Cellular and Molecular Mechanisms of Biological Aging: The Roles of Nature, Nurture and Chance in the Maintenance of Human Healthspan

Description: The degree to which an individual organism maintains healthspan and lifespan is a function of complex interactions between genetic inheritance ('nature'), environment, including cultural inheritance (nurture) and stochastic events ('luck' or 'chance'). This task group will focus upon the role of chance because it is so poorly understood and because it appears to be of major importance in the determination of individual variations in healthspan and lifespan within species. The major factor deter… more
Date: November 14, 2007
Creator: Weier, Heinz-Ulrich; Arya, Suresh; Grant, Christine; Miller, Linda; Ono, Santa Jeremy; Patil, Chris et al.
Partner: UNT Libraries Government Documents Department
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A Probabilistic Approach to Classifying Supernovae UsingPhotometric Information

Description: This paper presents a novel method for determining the probability that a supernova candidate belongs to a known supernova type (such as Ia, Ibc, IIL, etc.), using its photometric information alone. It is validated with Monte Carlo, and both space- and ground-based data. We examine the application of the method to well-sampled as well as poorly sampled supernova light curves and investigate to what extent the best currently available supernova models can be used for typing supernova candidates.… more
Date: December 14, 2006
Creator: Kuznetsova, Natalia V. & Connolly, Brian M.
Partner: UNT Libraries Government Documents Department
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Phases of QCD: Summary of the Rutgers Long Range Plan Town Meeting, January 12-14, 2007

Description: This White Paper summarizes the outcome of the Town Meeting on Phases of QCD that took place January 12-14, 2007 at Rutgers University, as part of the NSAC 2007 Long Range Planning process. The meeting was held in conjunction with the Town Meeting on Hadron Structure, including a full day of joint plenary sessions of the two meetings. Appendix A.1 contains the meeting agenda. This Executive Summary presents the prioritized recommendations that were determined at the meeting. Subsequent chapters… more
Date: May 14, 2007
Creator: Jacobs, Peter; Kharzeev, Dmitri; Muller, Berndt; Nagle, Jamie; Rajagopal, Krishna & Vigdor, Steve
Partner: UNT Libraries Government Documents Department
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High-Level Control System in C#*

Description: We have started upgrading the control room programs for the injector at the Advanced Light Source (ALS). We chose to program in C* exclusively on the .NET Framework to create EPICS client programs on Windows Vista PCs. This paper reports the status of this upgrade project.
Date: October 14, 2008
Creator: Nishimura, Hiroshi; Timossi, Chris; Portmann, Greg; Urashka, Michael.; Ikami, Craig & Beaudrow, M.
Partner: UNT Libraries Government Documents Department
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SQUID-Detected Magnetic Resonance Imaging in MicroteslaFields

Description: Magnetic resonance imaging (MRI) has developed into a powerful clinical tool for imaging the human body (1). This technique is based on nuclear magnetic resonance (NMR) of protons (2, 3) in a static magnetic field B{sub 0}. An applied radiofrequency pulse causes the protons to precess about B{sub 0} at their Larmor frequency {nu}{sub 0} = ({gamma}/2{pi})B{sub 0}, where {gamma} is the gyromagnetic ratio; {gamma}/2{pi} = 42.58 MHz/tesla. The precessing protons generate an oscillating magnetic fie… more
Date: August 14, 2006
Creator: Moessle, Michael; Hatridge, Michael & Clarke, John
Partner: UNT Libraries Government Documents Department
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Accelerating Full Configuration Interaction Calculations for Nuclear Structure

Description: One of the emerging computational approaches in nuclear physics is the full configuration interaction (FCI) method for solving the many-body nuclear Hamiltonian in a sufficiently large single-particle basis space to obtain exact answers - either directly or by extrapolation. The lowest eigenvalues and correspondingeigenvectors for very large, sparse and unstructured nuclear Hamiltonian matrices are obtained and used to evaluate additional experimental quantities. These matrices pose a significa… more
Date: April 14, 2008
Creator: Yang, Chao; Sternberg, Philip; Maris, Pieter; Ng, Esmond; Sosonkina, Masha; Le, Hung Viet et al.
Partner: UNT Libraries Government Documents Department
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Holographic optical elements for the extreme-ultravioletregime

Description: As the development of extreme ultraviolet (EUV) lithography progresses, interest grows in the extension of traditional optical components to the EUV regime. The strong absorption of EUV by most materials and its extremely short wavelength, however, makes it very difficult to implement many components that are commonplace in the longer wavelength regimes. One such component is the diffractive optical element used, for example, in illumination systems to efficiently generate modified pupil fills.… more
Date: August 14, 2006
Creator: Naulleau, Patrick P.; Salmassi, Farhad; Gullikson, Eric M. & Anderson, Erik H.
Partner: UNT Libraries Government Documents Department
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Optical Switching in VO2 films by below-gap excitation

Description: We study the photo-induced insulator-metal transition in VO2, correlating threshold and dynamic evolution with excitation wavelength. In high-quality single crystal samples, we find that switching can only be induced with photon energies above the 670-meV gap. This contrasts with the case of polycrystalline films, where formation of the metallic state can also be triggered with photon energies as low as 180 meV, well below the bandgap. Perfection of this process may be conducive to novel scheme… more
Date: March 14, 2008
Creator: Dipartimento di Fisica, Universita?di Brescia, Italy
Partner: UNT Libraries Government Documents Department
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Environmental Energy Technologies Division Newsletter, Fall 2007,Vol.4, No. 4)

Description: This issue's special focus is on advanced lithium ionbatteries for hybrid electric vehicle applications. The four articlesaddressing this area explore the modeling of lithium ion batterychemistries; the use of advanced diagnostic methods to study the physicsand chemistry of battery materials; a laboratory for advanced batterytesting; and approaches for improving battery safety. EETD's research isfunded by the Department of Energy's BATT (Batteries for AdvancedTransportation Technologies) progra… more
Date: December 14, 2007
Creator: Chen, Allan (Editor)
Partner: UNT Libraries Government Documents Department
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Localized Pd Overgrowth on Cubic Pt Nanocrystals for Enhanced Electrocatalytic Oxidation of Formic Acid

Description: Single crystalline surface such as (100), (111), (110) has been studied as an idealized platform for electrocatalytic reactions since the atomic arrangement affects a catalytic property. The secondary metal deposition on these surfaces also alters the catalytic property often showing improvement such as poisoning decrease. On the other hand, electrocatalysts used for practical purpose usually have a size on the order of nanometers. Therefore, linking the knowledge from single crystalline studie… more
Date: December 14, 2007
Creator: Lee, Hyunjoo; Habas, Susan; Somorjai, Gabor & Yang, Peidong
Partner: UNT Libraries Government Documents Department
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Structural Genomics of Minimal Organisms: Pipeline and Results

Description: The initial objective of the Berkeley Structural Genomics Center was to obtain a near complete three-dimensional (3D) structural information of all soluble proteins of two minimal organisms, closely related pathogens Mycoplasma genitalium and M. pneumoniae. The former has fewer than 500 genes and the latter has fewer than 700 genes. A semiautomated structural genomics pipeline was set up from target selection, cloning, expression, purification, and ultimately structural determination. At the ti… more
Date: September 14, 2007
Creator: Kim, Sung-Hou; Shin, Dong-Hae; Kim, Rosalind; Adams, Paul & Chandonia, John-Marc
Partner: UNT Libraries Government Documents Department
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Spontaneous Superlattice Formation in Nanorods through PartialCation Exchange

Description: Lattice mismatch strains are widely known to controlnanoscale pattern formation in heteroepitaxy, but such effects have notbeen exploited in colloidal nanocrystal growth. We demonstrate acolloidal route to synthesizing CdS-Ag2S nanorod superlattices throughpartial cation exchange. Strain induces the spontaneous formation ofperiodic structures. Ab initio calculations of the interfacial energy andmodeling of strain energies show that these forces drive theself-organization. The nanorod superlatti… more
Date: March 14, 2007
Creator: Robinson, Richard D.; Sadtler, Bryce; Demchenko, Denis O.; Erdonmez, Can K.; Wang, Lin-Wang & Alivisatos, A. Paul
Partner: UNT Libraries Government Documents Department
open access

Low-frequency asymptotic analysis of seismic reflection from afluid-saturated medium

Description: Reflection of a seismic wave from a plane interface betweentwo elastic media does not depend on the frequency. If one of the mediais poroelastic and fluid-saturated, then the reflection becomesfrequency-dependent. This paper presents a low-frequency asymptoticformula for the reflection of seismic plane p-wave from a fluid-saturatedporous medium. The obtained asymptotic scaling of the frequency-dependentcomponent of the reflection coefficient shows that it is asymptoticallyproportional to the sq… more
Date: April 14, 2004
Creator: Silin, D.B.; Korneev, V.A.; Goloshubin, G.M. & Patzek, T.W.
Partner: UNT Libraries Government Documents Department
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