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Extraordinary Light-Trapping Enhancement in Silicon Solar Cell Patterned with Graded Photonic Super-Crystals (open access)

Extraordinary Light-Trapping Enhancement in Silicon Solar Cell Patterned with Graded Photonic Super-Crystals

This article explores light-trapping enhancement in newly discovered graded photonic super-crystals (GPSCs) with dual periodicity and dual basis.
Date: December 7, 2017
Creator: Hassan, Safaa; Lowell, David; Adewole, Murthada; George, David; Zhang, Hualiang & Lin, Yuankun
System: The UNT Digital Library
Preliminary Assessment of Microbiome Changes Following Blood-Feeding and Survivorship in the Amblyomma americanum Nymph-to-Adult Transition using Semiconductor Sequencing (open access)

Preliminary Assessment of Microbiome Changes Following Blood-Feeding and Survivorship in the Amblyomma americanum Nymph-to-Adult Transition using Semiconductor Sequencing

Article on a preliminary assessment of microbiome changes following blood-feeding and survivorship in the Amblyomma americanum nymph-to-adult transition using semiconductor sequencing.
Date: June 20, 2013
Creator: Menchaca, Arturo C.; Visi, David K.; Strey, Otto F.; Teel, Pete D.; Kalinowski, Kevin E.; Allen, Michael S. et al.
System: The UNT Digital Library
The Genome-Wide Early Temporal Response of Saccharomyces cerevisiae to Oxidative Stress Induced by Cumene Hydroperoxide (open access)

The Genome-Wide Early Temporal Response of Saccharomyces cerevisiae to Oxidative Stress Induced by Cumene Hydroperoxide

Article on the genome-wide early temporal response of Saccharomyces cerevisiae to oxidative stress induced by cumene hydroperoxide.
Date: September 20, 2013
Creator: Sha, Wei; Martins, Ana M.; Laubenbacher, Reinhard; Mendes, Pedro & Shulaev, Vladimir
System: The UNT Digital Library
An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW—AAPL Automatic Anharmonic Phonon Library (open access)

An efficient and accurate framework for calculating lattice thermal conductivity of solids: AFLOW—AAPL Automatic Anharmonic Phonon Library

This article presents the Automatic Anharmonic Phonon Library.
Date: November 17, 2016
Creator: Plata, Jose J.; Nath, Pinku; Usanmaz, Demet; Carrete, Jesús; Toher, Cormac; de Jong, Maarten et al.
System: The UNT Digital Library
New Constraints on Isospin-Violating Dark Matter (open access)

New Constraints on Isospin-Violating Dark Matter

None
Date: March 20, 2013
Creator: Kumar, Jason; U., /Hawaii; Sanford, David; /UC, Irvine; Strigari, Louis E. & /KIPAC, Menlo Park /Stanford U., Phys. Dept.
System: The UNT Digital Library
Hadronic Decays Related to Gamma at BaBar (open access)

Hadronic Decays Related to Gamma at BaBar

None
Date: June 20, 2013
Creator: Lopez-March, Neus & /Valencia U., IFIC
System: The UNT Digital Library
Shielding of a hadron in a finite e-beam (open access)

Shielding of a hadron in a finite e-beam

The thorough study of coherent electron cooling, the modern cooling technique capable to deal with accelerators operating in the range of few TeVs, rises many interesting questions. One of them is a shielding dynamics of a hadron in an electron beam. Now this effect is computed analytically in the infinite beam approximation. Many effects are drastically different in finite and infinite plasmas. Here we propose a method to compute the dynamical shielding effect in a finite cylindrical plasma - the realistic model of an electron beam in accelerators.
Date: May 20, 2012
Creator: A., Elizarov; Litvinenko, V. & Wang, G.
System: The UNT Digital Library
Survey of nucleon electromagnetic form factors (open access)

Survey of nucleon electromagnetic form factors

There has been much activity in the measurement of the elastic electromagnetic proton and neutron form factors in the last decade, and the quality of the data has been greatly improved by performing double polarization experiments, in compar- ison with previous unpolarized data. Here we review the experimental data base in view of the new results for the proton, and neutron, obtained at MIT-Bates, MAMI, and JLab. The rapid evolution of phenomenological models triggered by these high-precision experiments will be discussed.
Date: September 20, 2011
Creator: Perdrisat, Charles F. & Punjabi, Vina A.
System: The UNT Digital Library
Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX-II) (open access)

Li+ alumino-silicate ion source development for the Neutralized Drift Compression Experiment (NDCX-II)

To heat targets to electron-volt temperatures for the study of warm dense matter with intense ion beams, low mass ions, such as lithium, have an energy loss peak (dE/dx) at a suitable kinetic energy. The Heavy Ion Fusion Sciences (HIFS) program at Lawrence Berkeley National Laboratory will carry out warm dense matter experiments using Li{sup +} ion beam with energy 1.2-4 MeV in order to achieve uniform heating up to 0.1-1 eV. The accelerator physics design of Neutralized Drift Compression Experiment (NDCX-II) has a pulse length at the ion source of about 0.5 {micro}s. Thus for producing 50 nC of beam charge, the required beam current is about 100 mA. Focusability requires a normalized (edge) emittance {approx}2 {pi}-mm-mrad. Here, lithium aluminosilicate ion sources, of {beta}-eucryptite, are being studied within the scope of NDCX-II construction. Several small (0.64 cm diameter) lithium aluminosilicate ion sources, on 70%-80% porous tungsten substrate, were operated in a pulsed mode. The distance between the source surface and the mid-plane of the extraction electrode (1 cm diameter aperture) was 1.48 cm. The source surface temperature was at 1220 C to 1300 C. A 5-6 {micro}s long beam pulsed was recorded by a Faraday cup (+300 V on …
Date: April 20, 2011
Creator: LBNL; Roy, P. K.; Greenway, W.; Kwan, J. W.; Seidl, P. A. & Waldron, W.
System: The UNT Digital Library
Effects of grids in drift tubes (open access)

Effects of grids in drift tubes

In 2011, we upgraded a 201 MHz buncher in the proton injector for the alternating gradient synchrotron (AGS) - relativistic heavy ion collider (RHIC) complex. In the buncher we installed four grids made of tungsten to improve the transit time factor. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a computerized numerically controlled (CNC) wire cutting electrical discharge machining (EDM). The 3D electric field of the grid was simulated.
Date: May 20, 2012
Creator: M., Okamura & Yamauchi, H.
System: The UNT Digital Library
3D Equilibrium Effects Due to RMP Application on DIII-D (open access)

3D Equilibrium Effects Due to RMP Application on DIII-D

The mitigation and suppression of edge localized modes (ELMs) through application of resonant magnetic perturbations (RMPs) in Tokamak plasmas is a well documented phenomenon [1]. Vacuum calculations suggest the formation of edge islands and stochastic regions when RMPs are applied to the axisymmetric equilibria. Self-consistent calculations of the plasma equilibrium with the VMEC [2] and SPEC [3] codes have been performed for an up-down symmetric shot (142603) in DIII-D. In these codes, a self-consistent calculation of the plasma response due to the RMP coils is calculated. The VMEC code globally enforces the constraints of ideal MHD; consequently, a continuously nested family of flux surfaces is enforced throughout the plasma domain. This approach necessarily precludes the observation of islands or field-line chaos. The SPEC code relaxes the constraints of ideal MHD locally, and allows for islands and field line chaos at or near the rational surfaces. Equilibria with finite pressure gradients are approximated by a set of discrete "ideal-interfaces" at the most irrational flux surfaces and where the strongest pressure gradients are observed. Both the VMEC and SPEC calculations are initialized from EFIT reconstructions of the plasma that are consistent with the experimental pressure and current profiles. A 3D reconstruction using …
Date: June 20, 2012
Creator: Lazerson, S.; Lazarus, E.; Hudson, S.; Pablant, N. & Gates, D.
System: The UNT Digital Library
NDCX-II, an Induction Linac for HEDP and IFE Research (open access)

NDCX-II, an Induction Linac for HEDP and IFE Research

The Heavy Ion Fusion Science Virtual National Laboratory in the USA is constructing a new Neutralized Drift Compression eXperiment (NDCX-II) at LBNL. This facility is being developed for high energy density physics and inertial fusion energy research. The 12 m long induction linac in NDCX-II will produce a Li{sup +} beam pulse, at energies of 1.2-3 MeV, to heat target material to the warm dense matter regime ({approx} 1 eV). By making use of special acceleration voltage waveforms, 2.5T solenoid focusing, and neutralized drift compression, 20 - 50 nC of beam charge from the ion source will be compressed longitudinally and radially to achieve a subnanosecond pulse length and mm-scale target spot size. The original Neutralized Drift Compression Experiment (NDCX-I) has successfully demonstrated simultaneous radial and longitudinal compression by imparting a velocity ramp to the ion beam, which then drifts in a neutralizing plasma to and through the final focussing solenoid and onto the target. At higher kinetic energy and current, NDCX-II will offer more than 100 times the peak energy fluence on target of NDCX-I. NDCX-II makes use of many parts from the decommissioned Advanced Test Accelerator (ATA) at LLNL. It includes 27 lattice periods between the injector and …
Date: April 20, 2011
Creator: Kwan, J. W.; Arbelaez, D.; Bieniosek, F. M.; Faltens, A.; Friedman, A.; Galvin, J. et al.
System: The UNT Digital Library
W+n-Jet Predictions With MC@NLO in Sherpa (open access)

W+n-Jet Predictions With MC@NLO in Sherpa

Results for the production of W-bosons in conjunction with up to three jets including parton shower corrections are presented and compared to recent LHC data. These results consistently incorporate the full next-to leading order QCD corrections through the MC{at}NLO method, as implemented in the SHERPA event generator, with the virtual corrections obtained from the BLACKHAT library.
Date: March 20, 2012
Creator: Hoeche, Stefan; Krauss, Frank; Schonherr, Marek & Siegert, Frank
System: The UNT Digital Library
How Common are the Magellanic Clouds (open access)

How Common are the Magellanic Clouds

We introduce a probabilistic approach to the problem of counting dwarf satellites around host galaxies in databases with limited redshift information. This technique is used to investigate the occurrence of satellites with luminosities similar to the Magellanic Clouds around hosts with properties similar to the Milky Way in the object catalog of the Sloan Digital Sky Survey. Our analysis uses data from SDSS Data Release 7, selecting candidate Milky-Way-like hosts from the spectroscopic catalog and candidate analogs of the Magellanic Clouds from the photometric catalog. Our principal result is the probability for a Milky-Way-like galaxy to host N{sub sat} close satellites with luminosities similar to the Magellanic Clouds. We find that 81 percent of galaxies like the Milky Way have no such satellites within a radius of 150 kpc, 11 percent have one, and only 3.5 percent of hosts have two. The probabilities are robust to changes in host and satellite selection criteria, background-estimation technique, and survey depth. These results demonstrate that the Milky Way has significantly more satellites than a typical galaxy of its luminosity; this fact is useful for understanding the larger cosmological context of our home galaxy.
Date: May 20, 2011
Creator: Liu, Lulu; Gerke, Brian F.; Wechsler, Risa H.; Behroozi, Peter S.; Busha, Michael T. & /KIPAC, Menlo Park /SLAC
System: The UNT Digital Library
Commissioning of a beta* knob for dynamic IR correction at RHIC (open access)

Commissioning of a beta* knob for dynamic IR correction at RHIC

In addition to the recent optics correction technique demonstrated at CERN and applied at RHIC, it is important to have a separate tool to control the value of the beta functions at the collision point ({beta}*). This becomes even more relevant when trying to reach high level of integrated luminosity while dealing with emittance blow-up over the length of a store, or taking advantage of compensation processes like stochastic cooling. Algorithms have been developed to allow modifying independently the beta function in each plane for each beam without significant increase in beam losses. The following reviews the principle of such algorithms and their experimental implementation as a dynamic {beta}-squeeze procedure.
Date: May 20, 2012
Creator: G., Robert-Demolaize; Marusic, A.; Tepikian, S. & White, S.
System: The UNT Digital Library
Bunch compressor design for potential FEL operation at eRHIC (open access)

Bunch compressor design for potential FEL operation at eRHIC

N/A
Date: May 20, 2012
Creator: Y., Jing; Hao, Y. & Litvinenko, V.
System: The UNT Digital Library
Coherent beam-beam effects observation and mitigation at the RHIC collider (open access)

Coherent beam-beam effects observation and mitigation at the RHIC collider

In polarized proton operation in RHIC coherent beam-beam modes are routinely observed with beam transfer function measurements in the vertical plane. With the existence of coherent modes a larger space is required in the tune diagram than without them and stable conditions can be compromised for operation with high intensity beams as foreseen for future luminosity upgrades. We report on experiments and simulations carried out to understand the existence of coherent modes in the vertical plane and their absence in the horizontal plane, and investigate possible mitigation strategies.
Date: May 20, 2012
Creator: S., White; Fischer, W. & Luo, Y.
System: The UNT Digital Library
Comparing new models of transverse instability with simulations (open access)

Comparing new models of transverse instability with simulations

Recently, Balbekov and Burov have produced an ordinary integro-differential equation that approximates the Vlasov equation for beams with wakefields and large space charge tune shift. The present work compares this model with simulations. In particular, the claim that certain types of transverse wakes cannot lead to mode coupling instabilities is explored.
Date: May 20, 2012
Creator: M., Blaskiewicz
System: The UNT Digital Library
Study of CP violation in Dalitz-plot analyses of B0 to K K-KS, B to K K-K , and B to KSKSK (open access)

Study of CP violation in Dalitz-plot analyses of B0 to K K-KS, B to K K-K , and B to KSKSK

We perform amplitude analyses of the decays B{sup 0} {yields} K{sup +}K{sup -}K{sub s}{sup 0}, B{sup +} {yields} K{sup +}K{sup -}K{sup +}, and B{sup +} {yields}, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately 470 x 10{sup 6} B{bar B} decays, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the SLAC National Accelerator Laboratory. For B{sup +} {yields} K{sup +}K{sup -}K{sup +}, we find a direct CP asymmetry in B{sup +} {yields} {phi}(1020)K{sup +} of A{sub CP} = (12.8 {+-} 4.4 {+-} 1.3)%, which differs from zero by 2.8{sigma}. For B{sup 0} {yields} K{sup +}K{sup -}K{sub s}{sup 0}, we measure the CP-violating phase {beta}{sub eff} ({phi}(1020)K{sub s}{sup 0}) = (21 {+-} 6 {+-} 2){sup o}. For B{sup +} {yields} K{sub s}{sup 0}K{sub s}{sup 0}K{sup +}, we measure an overall direct CP asymmetry of A{sub CP} = (4{sub -5}{sup +4} {+-} 2)%. We also perform an angular-moment analysis of the three channels, and determine that the f{sub X}(1500) state can be described well by the sum of the resonances f{sub 0}(1500), f{prime}{sub 2}(1525), and f{sub 0}(1710).
Date: March 20, 2012
Creator: Lees, J.P.
System: The UNT Digital Library
Optics measurements and corrections at RHIC (open access)

Optics measurements and corrections at RHIC

The further improvement of RHIC luminosity performance requires more precise understanding of the RHIC modeling. Hence, it is necessary to minimize the beta-beat, deviation of measured beta function from the calculated beta functions based on an model. The correction of betabeat also opens up the possibility of exploring operating RHIC polarized protons at a working point near integer, a prefered choice for both luminosity as well as beam polarization. The segment-by-segment technique for reducing beta-beat demonstrated in the LHC operation for reducing the beta-beat was first tested in RHIC during its polarized proton operation in 2011. It was then fully implemented during the RHIC polarized proton operation in 2012. This paper reports the commissioning results. Future plan is also presented.
Date: May 20, 2012
Creator: M., Bai; Aronson, J.; Blaskiewicz, M.; Luo, Y.; Robert-Demolaize, G. & White, S.
System: The UNT Digital Library
Utilizing interfaces: One-step forward for rational design of heterogeneous catalysts (open access)

Utilizing interfaces: One-step forward for rational design of heterogeneous catalysts

As far as heterogeneous catalysts are a composite material, physicochemical properties of the interfaces between individual components should be extensively studied for rational design of catalysts with desired properties. Here, I will present recent computational achievements in following three heterogeneous catalysts where the interface between composing materials plays a critical role
Date: June 20, 2013
Creator: Y., Kim H.
System: The UNT Digital Library
Preface to International Workshop on X-ray Mirror Design, Fabrication, and Metrology (open access)

Preface to International Workshop on X-ray Mirror Design, Fabrication, and Metrology

The International Workshop on X-Ray Mirror Design, Fabrication, and Metrology (IWXM), Osaka, Japan, was held as a satellite meeting of the Conference on Synchrotron Radiation Instrumentation (SRI) 2009, Melbourne, Australia, in October, 2009. The workshop was organized by a collaboration of scientists from a number of leading synchrotron institutions and universities around the World, such as Osaka University, SPring-8, KEK (Japan), ALS, APS and NSLS (USA), ELETTRA (Italy), ESRF, Synchrotron SOLEIL (France), BESSY (Germany), Diamond (UK), SSRF (China), NSRRC (Taiwan) and PAL (Korea). The workshop followed a series of parallel workshops focused on metrology (1st, 2nd and 3rd International Workshop on Metrology for X-ray and Neutron Optics) and on active X-ray optics (1st and 2nd X-ray and XUV Active Optics Workshop, ACTOP06 and ACTOP08) and included the 3rd workshop on X-ray and EUV active optics (ACTOP09). The workshop brought together more than 100 participants: manufacturers, optical and mechanical engineers, designers, and users of X-ray optics; allowing for free exchange of ideas, highlighting of existing problems and challenges, and searching for ways to improve existing instrumentation for sub-microradian and sub-nanometer accuracy. A visit to the Osaka University mirror fabrication laboratory, SPring-8, and the X-ray free electron laser (XFEL) facility was included …
Date: April 20, 2010
Creator: Yamauchi, Kazuto; Yashchuk, Valeriy V. & Cocco, Daniele
System: The UNT Digital Library
Hiding a Heavy Higgs Boson at the 7 TeV LHC (open access)

Hiding a Heavy Higgs Boson at the 7 TeV LHC

A heavy Standard Model Higgs boson is not only disfavored by electroweak precision observables but is also excluded by direct searches at the 7 TeV LHC for a wide range of masses. Here, we examine scenarios where a heavy Higgs boson can be made consistent with both the indirect constraints and the direct null searches by adding only one new particle beyond the Standard Model. This new particle should be a weak multiplet in order to have additional contributions to the oblique parameters. If it is a color singlet, we find that a heavy Higgs with an intermediate mass of 200-300 GeV can decay into the new states, suppressing the branching ratios for the standard model modes, and thus hiding a heavy Higgs at the LHC. If the new particle is also charged under QCD, the Higgs production cross section from gluon fusion can be reduced significantly due to the new colored particle one-loop contribution. Current collider constraints on the new particles allow for viable parameter space to exist in order to hide a heavy Higgs boson. We categorize the general signatures of these new particles, identify favored regions of their parameter space and point out that discovering or excluding …
Date: March 20, 2012
Creator: Bai, Yang; Fan, JiJi & Hewett, JoAnne L.
System: The UNT Digital Library
A Search for the Decay Modes B +/- to h +/- tau l (open access)

A Search for the Decay Modes B +/- to h +/- tau l

We present a search for the lepton flavor violating decay modes B{sup {+-}} {yields} h{sup {+-}} {tau}{ell} (h = K, {pi}; {ell} = e, {mu}) using the BABAR data sample, which corresponds to 472 million B{bar B} pairs. The search uses events where one B meson is fully reconstructed in one of several hadronic final states. Using the momenta of the reconstructed B, h, and {ell} candidates, we are able to fully determine the {tau} four-momentum. The resulting {tau} candidate mass is our main discriminant against combinatorial background. We see no evidence for B{sup {+-}} {yields} h{sup {+-}} {tau}{ell} decays and set a 90% confidence level upper limit on each branching fraction at the level of a few times 10{sup -5}.
Date: July 20, 2012
Creator: Lees, J.P.
System: The UNT Digital Library