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3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration (open access)

3-D Model of Broadband Emission from Supernova Remnants Undergoing Non-linear Diffusive Shock Acceleration

We present a 3-dimensional model of supernova remnants (SNRs) where the hydrodynamical evolution of the remnant is modeled consistently with nonlinear diffusive shock acceleration occurring at the outer blast wave. The model includes particle escape and diffusion outside of the forward shock, and particle interactions with arbitrary distributions of external ambient material, such as molecular clouds. We include synchrotron emission and cooling, bremsstrahlung radiation, neutral pion production, inverse-Compton (IC), and Coulomb energy-loss. Boardband spectra have been calculated for typical parameters including dense regions of gas external to a 1000 year old SNR. In this paper, we describe the details of our model but do not attempt a detailed fit to any specific remnant. We also do not include magnetic field amplification (MFA), even though this effect may be important in some young remnants. In this first presentation of the model we don't attempt a detailed fit to any specific remnant. Our aim is to develop a flexible platform, which can be generalized to include effects such as MFA, and which can be easily adapted to various SNR environments, including Type Ia SNRs, which explode in a constant density medium, and Type II SNRs, which explode in a pre-supernova wind. When …
Date: July 2, 2008
Creator: Lee, Shiu-Hang; Kamae, Tuneyoshi & Ellison, Donald C.
System: The UNT Digital Library
10-kJ Status and 100-kJ Future for NIF PetaWatt Technology (open access)

10-kJ Status and 100-kJ Future for NIF PetaWatt Technology

We discuss the status of the NIF ARC, an 8-beam 10-kJ class high-energy petawatt laser, and the future upgrade path of this and similar systems to 100-kJ-class with coherent phasing of multiple apertures.
Date: July 2, 2007
Creator: Siders, C W; Crane, J K; Rushford, M C; Haefner, L C; Hernandez, J E; Dawson, J W et al.
System: The UNT Digital Library
25-ps neutron detector for measuring ICF-target burn history (open access)

25-ps neutron detector for measuring ICF-target burn history

We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response < 25 ps FWHM. A thin piece of scintillator material acts as a neutron-to-light converter. A zoom lens images scintillator light to a high-speed (15 ps) optical streak camera for recording. A retractable nose cone positions the scintillator between 1 and 50 cm from a target. A simultaneously recorded optical fiducial pulse allows the streak camera time base to be calibrated relative to the incident laser power. Burn histories have been measured for deuterium-tritium filled targets with yields ranging between 10{sup 8} and 2 {times} 10{sup 13} neutrons.
Date: May 2, 1994
Creator: Lerche, R. A.; Phillion, D. W. & Tietbohl, G. L.
System: The UNT Digital Library
The 60-month all-sky BAT Survey of AGN and the Anisotropy of Nearby AGN (open access)

The 60-month all-sky BAT Survey of AGN and the Anisotropy of Nearby AGN

Surveys above 10 keV represent one of the the best resources to provide an unbiased census of the population of Active Galactic Nuclei (AGN). We present the results of 60 months of observation of the hard X-ray sky with Swift/BAT. In this timeframe, BAT detected (in the 15-55 keV band) 720 sources in an all-sky survey of which 428 are associated with AGN, most of which are nearby. Our sample has negligible incompleteness and statistics a factor of {approx}2 larger over similarly complete sets of AGN. Our sample contains (at least) 15 bona-fide Compton-thick AGN and 3 likely candidates. Compton-thick AGN represent a {approx}5% of AGN samples detected above 15 keV. We use the BAT dataset to refine the determination of the LogN-LogS of AGN which is extremely important, now that NuSTAR prepares for launch, towards assessing the AGN contribution to the cosmic X-ray background. We show that the LogN-LogS of AGN selected above 10 keV is now established to a {approx}10% precision. We derive the luminosity function of Compton-thick AGN and measure a space density of 7.9{sub -2.9}{sup +4.1} x 10{sup -5} Mpc{sup -3} for objects with a de-absorbed luminosity larger than 2 x 10{sup 42} erg s{sup -1}. …
Date: April 2, 2012
Creator: Ajello, M.; /KIPAC, Menlo Park; Alexander, D.M.; U., /Durham; Greiner, J.; /Garching, Max Planck Inst., MPE et al.
System: The UNT Digital Library
300 AREA URANIUM CONTAMINATION (open access)

300 AREA URANIUM CONTAMINATION

{sm_bullet} Uranium fuel production {sm_bullet} Test reactor and separations experiments {sm_bullet} Animal and radiobiology experiments conducted at the. 331 Laboratory Complex {sm_bullet} .Deactivation, decontamination, decommissioning,. and demolition of 300 Area facilities
Date: July 2, 2009
Creator: Borghese, J. V.
System: The UNT Digital Library
137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska (open access)

137Cs and 210Po in Pacific Walrus and Bearded Seal from St. Lawrence Island, Alaska

The activity concentration of Cesium-137 ({sup 137}Cs) and naturally-occurring Polonium-210 ({sup 210}Po) were measured in the muscle tissue, kidney and liver of Pacific walrus (Odobenus rosmarus divergens) and bearded seal (Erignathus barbatus) collected by native hunters from the Bering Sea. The mean {sup 137}Cs concentrations in muscle, liver and kidney of Pacific walrus were 0.07, 0.09 and 0.07 Bq kg{sup -1} (N= 5, wet weight), respectively, and 0.17, 0.10, and 0.17 Bq kg{sup -1} (N=2, wet weight), respectively, in bearded seal. In general, {sup 137}Cs tissue concentrations are significantly lower than those previously reported for mammals from other regions. By comparison, {sup 210}Po activity concentrations appear to be higher than those reported elsewhere but a larger variation. The mean {sup 210}Po concentration in the muscle tissue, liver and kidney of Pacific walrus (N=5, wet weight) were 28.7, 189, and 174 Bq kg{sup -1}, respectively. This compares with {sup 210}Po concentration values (N=2, wet weight) of 27, 207, and 68 Bq kg{sup -1} measured in the muscle tissue, liver and kidney, of bearded seal, respectively. Estimated bioaccumulation factors--as defined by the radionuclide concentration ratio between the target tissue to that in sea water--were two to three orders of magnitude higher for …
Date: February 2, 2005
Creator: Hamilton, T F; Seagars, D J; Jokela, T & Layton, D
System: The UNT Digital Library
2002 Gordon Research Conference on Mutagenesis. Final Progress Report (open access)

2002 Gordon Research Conference on Mutagenesis. Final Progress Report

The Gordon Research Conference (GRC) on MUTAGENESIS was held at Bates College from 7/28/02 thru 8/2/02. The Conference was well-attended with 157 participants. The attendees represented the spectrum of endeavor in this field coming from academia, industry, and government laboratories, both U.S. and foreign scientists, senior researchers, young investigators, and students.
Date: August 2, 2002
Creator: unknown
System: The UNT Digital Library
2006 Vibrational Spectroscopy Gordon Conference (open access)

2006 Vibrational Spectroscopy Gordon Conference

This Report is Description of Vibrational Spectroscopy at Gordon Conference
Date: July 2, 2006
Creator: Crim, Forrest Fleming
System: The UNT Digital Library
2010 CATALYSIS GORDON RESEARCH CONFERENCE, JUNE 27 - JULY 2, 2010, NEW LONDON, NEW HAMPSHIRE (open access)

2010 CATALYSIS GORDON RESEARCH CONFERENCE, JUNE 27 - JULY 2, 2010, NEW LONDON, NEW HAMPSHIRE

Catalysis is a key technology for improving the quality of life while simultaneously reducing the adverse impact of human activities on the environment. The discovery of new catalytic processes and the improvement of existing ones are also critically important for securing the nation's energy supply. The GRC on Catalysis is considered one the most prestigious conference for catalysis research, bringing together leading researchers from both academia, industry and national labs to discuss the latest, most exciting research in catalysis and the future directions for the field. The 2010 GRC on Catalysis will follow time-honored traditions and feature invited talks from the world's leading experts in the fundamentals and applications of catalytic science and technology. We plan to have increased participation from industry. The extended discussions in the company of outstanding thinkers will stimulate and foster new science. The conference will include talks in the following areas: Alternative feedstocks for chemicals and fuels, Imaging and spectroscopy, Design of novel catalysts, Catalyst preparation fundamentals, Molecular insights through theory, Surface Science, Catalyst stability and dynamics. In 2010, the Catalysis conference will move to a larger conference room with a new poster session area that will allow 40 posters per session. The dorm rooms …
Date: July 2, 2010
Creator: Datye, Abhaya
System: The UNT Digital Library
2010 POLYMER PHYSICS - JUNE 27 - JULY 2, 2010 (open access)

2010 POLYMER PHYSICS - JUNE 27 - JULY 2, 2010

The 2010 Gordon Research Conference on Polymer Physics will provide outstanding lectures and discussions in this critical field that impacts every industrial sector from electronics to transportation to medicine to textiles to energy generation and storage. Fundamental topics range from mechanical properties of soft gels to new understanding in polymer crystallization to energy conversion and transmission to simulating polymer dynamics at the nanoscale. This international conference will feature 22 invited lectures, wherein the opening 10 minutes are specifically designed for a general polymer physics audience. In addition, poster sessions and informal activities provide ample opportunity to discuss the latest advances in polymer physics. The technical content of the meeting will include new twists on traditional polymer physics topics, recent advances in previously underrepresented topics, and emerging technologies enabled by polymer physics. Here is a partially listing of targeted topics: (1) electrically-active and light-responsive polymers and polymer-based materials used in energy conversion and storage; (2) polymers with hierarchical structures including supramolecular assemblies, ion-containing polymers, and self-assembled block polymers; (3) mechanical and rheological properties of soft materials, such as hydrogels, and of heterogeneous materials, particularly microphase separated polymers and polymer nanocomposites; and (4) crystallization of polymers in dilute solutions, polymer melts, and …
Date: July 2, 2010
Creator: Winey, Karen
System: The UNT Digital Library
2nd International Workshop on Laboratory Astrophysics With Intense Lasers Book of Abstracts (open access)

2nd International Workshop on Laboratory Astrophysics With Intense Lasers Book of Abstracts

None
Date: March 2, 1998
Creator: Remington, B. A.
System: The UNT Digital Library
A 3D Contact Smoothing Method (open access)

A 3D Contact Smoothing Method

Smoothing of contact surfaces can be used to eliminate the chatter typically seen with node on facet contact and give a better representation of the actual contact surface. The latter affect is well demonstrated for problems with interference fits. In this work we present two methods for the smoothing of contact surfaces for 3D finite element contact. In the first method, we employ Gregory patches to smooth the faceted surface in a node on facet implementation. In the second method, we employ a Bezier interpolation of the faceted surface in a mortar method implementation of contact. As is well known, node on facet approaches can exhibit locking due to the failure of the Babuska-Brezzi condition and in some instances fail the patch test. The mortar method implementation is stable and provides optimal convergence in the energy of error. In the this work we demonstrate the superiority of the smoothed versus the non-smoothed node on facet implementations. We also show where the node on facet method fails and some results from the smoothed mortar method implementation.
Date: May 2, 2002
Creator: Puso, M. A. & Laursen, T. A.
System: The UNT Digital Library
3D Simulations of Multipacting in the 56 MHz SRF Cavity (open access)

3D Simulations of Multipacting in the 56 MHz SRF Cavity

This report addresses the 56 MHz SRF Quarter-Wave Resonator (QWR) is designed for RHIC as a storage cavity to improve the collider performance.
Date: October 2, 2013
Creator: Wu, Q.; Belomestnykh, S. A.; Ge, L.; Ko, C.; Li, Z.; Ng, C. K. et al.
System: The UNT Digital Library
4D Emittance Measurements Using Multiple Wire and Waist Scan Methods in the ATF Extraction Line (open access)

4D Emittance Measurements Using Multiple Wire and Waist Scan Methods in the ATF Extraction Line

Emittance measurements performed in the diagnostic section of the Accelerator Test Facility (ATF) extraction line since 1998 led to vertical emittances three times larger than the expected ones, with a strong dependence on intensity. An experimental program is pursued to investigate potential sources of emittance growth and find possible remedies. This requires efficient and reliable emittance measurement techniques. In the past, several phase-space reconstruction methods developed at SLAC and KEK have been used to estimate the vertical emittance, based on multiple location beam size measurements and dedicated quadrupole scans. These methods have been shown to be very sensitive to measurement errors and other fluctuations in the beam conditions. In this context new emittance measurements have been performed revisiting these methods and newly developed ones with a systematic approach to compare and characterise their performance in the ATF extraction line.
Date: November 2, 2011
Creator: Rimbault, C.; Bambade, P.; Brossard, J.; Alabau, M.; Kuroda, S.; Scarfe, A. et al.
System: The UNT Digital Library
7Be(p,(gamma))8B S-factor from Ab Initio No-Core Shell Model Wave Functions (open access)

7Be(p,(gamma))8B S-factor from Ab Initio No-Core Shell Model Wave Functions

Nuclear structure of {sup 7}Be, {sup 8}B and {sup 7,8}Li is studied within the ab initio no-core shell model (NCSM). Starting from high-precision nucleon-nucleon (NN) interactions, wave functions of {sup 7}Be and {sup 8}B bound states are obtained in basis spaces up to 10 h bar{Omega} and used to calculate channel cluster form factors (overlap integrals) of the {sup 8}B ground state with {sup 7}Be+p. Due to the use of the harmonic oscillator (HO) basis, the overlap integrals have incorrect asymptotic properties. We fix this problem in two alternative ways. First, by a Woods-Saxon (WS) potential solution fit to the interior of the NCSM overlap integrals. Second, by a direct matching with the Whittaker function. The corrected overlap integrals are then used for the {sup 7}Be(p,{gamma}){sup 8}B S-factor calculation. We study the convergence of the S-factor with respect to the NCSM HO frequency and the model space size. Our S-factor results are in agreement with recent direct measurement data. We also test the spectroscopic factors and the corrected overlap integrals from the NCSM in describing the momentum distributions in knockout reactions with {sup 8}B projectiles. A good agreement with the available experimental data is also found, attesting the overall consistency …
Date: December 2, 2005
Creator: Navratil, P; Bertulani, C A & Caurier, E
System: The UNT Digital Library
Ab Initio and Ab Exitu No-Core Shell Model (open access)

Ab Initio and Ab Exitu No-Core Shell Model

We outline two complementary approaches based on the no core shell model (NCSM) and present recent results. In the ab initio approach, nuclear properties are evaluated with two-nucleon (NN) and three-nucleon interactions (TNI) derived within effective field theory (EFT) based on chiral perturbation theory (ChPT). Fitting two available parameters of the TNI generates good descriptions of light nuclei. In a second effort, an ab exitu approach, results are obtained with a realistic NN interaction derived by inverse scattering theory with off-shell properties tuned to fit light nuclei. Both approaches produce good results for observables sensitive to spin-orbit properties.
Date: October 2, 2007
Creator: Vary, J. P.; Navratil, P.; Gueorguiev, V. G.; Ormand, W. E.; Nogga, A.; Maris, P. et al.
System: The UNT Digital Library
AB Initio Calculations of Elastic Constants of BCC V-NB System at High Pressures (open access)

AB Initio Calculations of Elastic Constants of BCC V-NB System at High Pressures

First-principles total energy calculation based on the exact muffin-tin orbital and full potential linear muffin-tin orbital methods were used to calculate the equation of state and shear elastic constants of bcc V, Nb, and the V{sub 95}Nb{sub 05} disordered alloy as a function of pressure up to 6 Mbar. We found a mechanical instability in C{sub 44} and a corresponding softening in C at pressures {approx} 2 Mbar for V. Both shear elastic constants show softening at pressures {approx} 0.5 Mbar for Nb. Substitution of 5 at. % of V with Nb removes the instability of V with respect to trigonal distortions in the vicinity of 2 Mbar pressure, but still leaves the softening of C{sub 44} in this pressure region. We argue that the pressure induced shear instability (softening) of V (Nb) originates from the electronic system and can be explained by a combination of the Fermi surface nesting, electronic topological transition, and band Jahn-Teller effect.
Date: May 2, 2005
Creator: Landa, A; Klepeis, J; Soderlind, P; Naumov, I; Velikokhatnyi, O; Vitos, L et al.
System: The UNT Digital Library
Ab-Initio No-Core Shell Model (open access)

Ab-Initio No-Core Shell Model

We discuss the no-core shell model approach, an ab initio method with effective Hamiltonians derived from realistic nucleon-nucleon (NN) potentials as a function of the finite harmonic-oscillator (HO) basis space. We present results for three and four nucleon systems in model spaces that include up to 50{Dirac_h}{Omega} and 18{bar h}{Omega} HO excitations, respectively. For these light systems we are in agreement with results obtained by other exact methods. Also, we calculate the properties of {sup 6}Li and {sup 6}He in model spaces up to 10{Dirac_h}{Omega}, and of {sup 12}C for model spaces up to 6{Dirac_h}{Omega}.
Date: March 2, 2001
Creator: Barrett, B R; Navratil, P; Vary, J P & Ormand, W E
System: The UNT Digital Library
Abscisic acid regulates secondary cell-wall formation and lignin deposition in Arabidopsis thaliana through phosphorylation of NST1 (open access)

Abscisic acid regulates secondary cell-wall formation and lignin deposition in Arabidopsis thaliana through phosphorylation of NST1

Article using a combination of biochemical and genetic approaches to show how ABA can regulate lignin biosynthesis. This work provides a basis for designing trees and other biomass plants that are better adapted to stress and climate change. This article includes a correction on the first page.
Date: February 2, 2021
Creator: Liu, Chang; Yu, Hasi; Rao, Xiaolan; Li, Laigeng & Dixon, R. A.
System: The UNT Digital Library
AC magnetohydrodynamic microfluidic switch (open access)

AC magnetohydrodynamic microfluidic switch

A microfluidic switch has been demonstrated using an AC Magnetohydrodynamic (MHD) pumping mechanism in which the Lorentz force is used to pump an electrolytic solution. By integrating two AC MHD pumps into different arms of a Y-shaped fluidic circuit, flow can be switched between the two arms. This type of switch can be used to produce complex fluidic routing, which may have multiple applications in {micro}TAS.
Date: March 2, 2000
Creator: Lemoff, A V & Lee, A P
System: The UNT Digital Library
Accelerated Aging of Polyimide/Titanium Adhesive Bonds Using the Notched Coating Adhesion Test (open access)

Accelerated Aging of Polyimide/Titanium Adhesive Bonds Using the Notched Coating Adhesion Test

None
Date: October 2, 2000
Creator: Giunta, R. K. & Kander, R. G.
System: The UNT Digital Library
Accelerating and Colliding Polarized Protons in RHIC With Siberian Snakes (open access)

Accelerating and Colliding Polarized Protons in RHIC With Siberian Snakes

We successfully injected polarized protons in both RHIC rings and maintained polarization during acceleration up to 100 GeV per ring using two Siberian snakes in each ring. Each snake consists of four helical superconducting dipoles which rotate the polarization by 180{sup o} about a horizontal axis. This is the first time that polarized protons have been accelerated to 100 GeV. We report on our experiences during commissioning and operation of collider with polarized protons.
Date: June 2, 2002
Creator: Roser, T.; Ahrens, L.; Alessi, J.; Bai, M.; Beebe-Wang, J.; Brennan, J. M. et al.
System: The UNT Digital Library
ACCELERATING POLARIZED PROTONS TO HIGH ENERGY. (open access)

ACCELERATING POLARIZED PROTONS TO HIGH ENERGY.

The Relativistic Heavy Ion Collider (RHIC) is designed to provide collisions of high energy polarized protons for the quest of understanding the proton spin structure. Polarized proton collisions at a beam energy of 100 GeV have been achieved in RHIC since 2001. Recently, polarized proton beam was accelerated to 250 GeV in RHIC for the first time. Unlike accelerating unpolarized protons, the challenge for achieving high energy polarized protons is to fight the various mechanisms in an accelerator that can lead to partial or total polarization loss due to the interaction of the spin vector with the magnetic fields. We report on the progress of the RHIC polarized proton program. We also present the strategies of how to preserve the polarization through the entire acceleration chain, i.e. a 200 MeV linear accelerator, the Booster, the AGS and RHIC.
Date: October 2, 2006
Creator: Bai, M.; Ahrens, L.; Alekseev, I. G.; Alessi, J.; Beebe-Wang, J.; Blaskiewicz, M. et al.
System: The UNT Digital Library
An accelerator controls network designed for reliability and flexibility (open access)

An accelerator controls network designed for reliability and flexibility

The APS accelerator control system is a typical modern system based on the standard control system model, which consists of operator interfaces to a network and computer-controlled interfaces to hardware. The network provides a generalized communication path between the host computers, operator workstations, input/output crates, and other hardware that comprise the control system. The network is an integral part of all modern control systems and network performance will determine many characteristics of a control system. This paper describes the methods used to provide redundancy for various network system components as well as methods used to provide comprehensive monitoring of this network. The effect of archiving tens of thousands of data points on a regular basis and the effect on the controls network will be discussed. Metrics are provided on the performance of the system under various conditions.
Date: December 2, 1997
Creator: McDowell, W. P. & Sidorowicz, K. V.
System: The UNT Digital Library