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$D^0 \bar{D}^0$ Mixing at BaBar (open access)

$D^0 \bar{D}^0$ Mixing at BaBar

This article reviews the recent measurement of D{sup 0}-{bar D}{sup 0} mixing with the D{sup 0} {yields} K{pi} decay channel from the BABAR experiment at the PEP-II B-Factory. Averages from the Heavy Flavor Averaging Group between this result and a previous result from BELLE are also presented.
Date: October 26, 2011
Creator: Coleman, Jonathon
System: The UNT Digital Library
A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs (open access)

A 3-D hydrodynamic dispersion model for modeling tracer transport in Geothermal Reservoirs

A 3-D hydrodynamic dispersion model for tracer transport is developed and implemented into the TOUGH2 EOS3 (T2R3D) module. The model formulation incorporates a full dispersion tensor, based on a 3-D velocity field with a 3-D, irregular grid in a heterogeneous geological system. Two different weighting schemes are proposed for spatial average of 3-D velocity fields and concentration gradients to evaluate the mass flux by dispersion and diffusion of a tracer or a radionuclide. This new module of the TOUGH2 code is designed to simulate processes of tracer/radionuclide transport using an irregular, 3-D integral finite difference grid in non-isothermal, three-dimensional, multiphase, porous/fractured subsurface systems. The numerical method for this transport module is based on the integral finite difference scheme, as in the TOUGH2 code. The major assumptions of the tracer transport module are: (a) a tracer or a radionuclide is present and transported only within the liquid phase, (b) transport mechanisms include molecular diffusion and hydrodynamic dispersion in the liquid phase in addition to advection, and (c) first order decay and linear adsorption on rock grains are taken into account. The tracer or radionuclide is introduced as an additional mass component into the standard TOUGH2 formulation, time is discretized fully implicitly, …
Date: January 26, 1998
Creator: Wu, Yu-Shu & Pruess, Karsten
System: The UNT Digital Library
[5,10,15,20-Tetrakis(4-tolyl)porphyrin]-zinc(II) dichloromethane solvate (open access)

[5,10,15,20-Tetrakis(4-tolyl)porphyrin]-zinc(II) dichloromethane solvate

In the title complex, [Zn(C₄₈H₃₆N₄)]·CH₂Cl₂, the Znᴵᴵ atom lies on an inversion center and the dichloromethane solvent molecule is disordered around an inversion center.
Date: May 26, 2010
Creator: McGill, Sean; Nesterov, Vladimir N. & Gould, Stephanie L.
System: The UNT Digital Library
11.424 Ghz Stripline Transversal Filter for Sub-Picosecond Bunch Timing Measurements (open access)

11.424 Ghz Stripline Transversal Filter for Sub-Picosecond Bunch Timing Measurements

Measurement of time-of-arrival or instantaneous longitudinal position is a fundamental beam diagnostic. We present results from a stripline transversal periodic coupler structure which forms the heart of a sub-ps beam timing detector. This filter structure approximates a sinx/x response in the frequency domain which corresponds to a limited pulse length response in the time domain. These techniques have been used extensively in beam feedback systems at 3 GHz center frequencies with operational single-shot resolutions of 200 fs [1]. We present a new design, based on a 11.424 GHz center frequency, which is intended to offer a factor of four improvement in time resolution. Two-dimensional electromagnetic simulation results are shown, and the design optimization approach leading to the final circuit implementation is illustrated. The prototype circuit has been fabricated on 64mil Rogers 4003 and lab frequency domain and time domain data are compared to the 2-D simulation results. Performance of the prototype circuit is shown with applicability to sub-ps beam measurements in LINAC and FEL applications.
Date: August 26, 2010
Creator: Van Winkle, D.; Young, A. & Fox, J. D.
System: The UNT Digital Library
A 15-T Pulsed Solenoid for a High-Power Target Experiment (open access)

A 15-T Pulsed Solenoid for a High-Power Target Experiment

The MERIT experiment, to be run at CERN in 2007, is a proof-of-principle test for a target system that converts a 4-MW proton beam into a high-intensity muon beam for either a neutrino factory complex or a muon collider. The target system is based on a free mercury jet that intercepts an intense proton beam inside a 15-T solenoidal magnetic field. Here, we describe the design and initial performance of the 15-T, liquid-nitrogen-precooled, copper solenoid magnet.
Date: June 26, 2006
Creator: Kirk, H. G.; Efthymiopoulos, I.; Fabich, A.; Haug, R.; Titus, P.; McDonald, K. T. et al.
System: The UNT Digital Library
1963 revisited: should we set a precedent of recalculating old exposures (open access)

1963 revisited: should we set a precedent of recalculating old exposures

This paper describes recent experience in re-evaluating the dose to an employee. This employee was plagued with skin disorders for years, but he questioned his recorded beta dose only after a recent LLNL cancer study began collecting data. He was concerned that his radiation dose recorded during the time he worked on a fission burst reactor experiment in 1963 did not represent the actual dose he received. About six months were spent gathering information, putting the information together, making necessary calculations, and reaching a reasonable result (a reasonable result being one for which the known information fits the calculated results with a minimum of inconsistencies). This paper presents the beta and gamma whole-body and hand radiation dose calculations, and compares these calculated dose rates with the meter, film, and pocket dosimeter information recorded in the health and safety log, operation log, and dosimetry record.
Date: October 26, 1981
Creator: Hoots, S.S.
System: The UNT Digital Library
1st-Principles Step- and Kink-Formation Energies on Cu(111) (open access)

1st-Principles Step- and Kink-Formation Energies on Cu(111)

In rough agreement with experimental values derived from Cu island shapes vs. temperature, ab-initio calculations yield formation energies of 0.27 and 0.26 eV/ step-edge-atom for (100)- and (111)-micro facet steps on Cu(lll), and 0.09 and 0.12 eV per kink in those steps. Comparison to ab-initio results for Al and Pt shows that as a rule, the average formation energy of straight steps on a close-packed metal surface equals -7% of the metal's cohesive energy.
Date: May 26, 1999
Creator: Feibelman, Peter J.
System: The UNT Digital Library
2001 Gordon Research Conference on Mammalian DNA Repair. Final progress report (open access)

2001 Gordon Research Conference on Mammalian DNA Repair. Final progress report

None
Date: January 26, 2001
Creator: unknown
System: The UNT Digital Library
The 2005 National Conference of Black Physics Students (open access)

The 2005 National Conference of Black Physics Students

This proposal funded the 19th Annual National Conference of Black Physics Students. This conference provided physics students with the opportunity to interact with world-class researchers and the facilities at which they work. The conference supports the well established need for the US to foster a larger and stronger scientific workforce through the recruitment and retention of science and engineering students.
Date: September 26, 2006
Creator: Reid, David D.
System: The UNT Digital Library
2009 CLEO Plenary Session - OPN Article Questions (open access)

2009 CLEO Plenary Session - OPN Article Questions

None
Date: February 26, 2009
Creator: Moses, Edward
System: The UNT Digital Library
21nm X-Ray Laser Thomson Scattering of Laser-Heated Exploding Foil Plasmas (open access)

21nm X-Ray Laser Thomson Scattering of Laser-Heated Exploding Foil Plasmas

Recent experiments were carried out on the Prague Asterix Laser System (PALS) towards the demonstration of a soft x-ray laser Thomson scattering diagnostic for a laser-produced exploding foil. The Thomson probe utilized the Ne-like zinc x-ray laser which was double-passed to deliver {approx}1 mJ of focused energy at 21.2 nm wavelength and lasting {approx}100 ps. The plasma under study was heated single-sided using a Gaussian 300-ps pulse of 438-nm light (3{omega} of the PALS iodine laser) at laser irradiances of 10{sup 13}-10{sup 14} W cm{sup -2}. Electron densities of 10{sup 20}-10{sup 22} cm{sup -3} and electron temperatures from 200 to 500 eV were probed at 0.5 or 1 ns after the peak of the heating pulse during the foil plasma expansion. A flat-field 1200 line mm{sup -1} variable-spaced grating spectrometer with a cooled charge-coupled device readout viewed the plasma in the forward direction at 30{sup o} with respect to the x-ray laser probe. We show results from plasmas generated from {approx}1 {micro}m thick targets of Al and polypropylene (C{sub 3}H{sub 6}). Numerical simulations of the Thomson scattering cross-sections will be presented. These simulations show electron peaks in addition to a narrow ion feature due to collective (incoherent) Thomson scattering. The …
Date: September 26, 2007
Creator: Dunn, J.; Rus, B.; Mocek, T.; Nelson, A. J.; Foord, M. E.; Rozmus, W. et al.
System: The UNT Digital Library
27Al and 1H Solid State NMR Studies Show Evidence of TiAl3 and TiH2 in Ti-doped NaAlH4 (open access)

27Al and 1H Solid State NMR Studies Show Evidence of TiAl3 and TiH2 in Ti-doped NaAlH4

Previous X-ray Diffraction (XRD) and Nuclear Magnetic Resonance (NMR) studies on Ti-doped NaAlH{sub 4} revealed the reaction products of two heavily doped (33.3 at.%) samples that were solvent-mixed and mechanically-milled. This investigation revealed that nano-crystalline or amorphous Al{sub 2}O{sub 3} forms from the possible coordination of aluminum with oxygen atom of the furan ring system from added tetrahydrofuran (THF) in the solvent-mixed sample, and that TiAl{sub 3} forms in mechanically-milled samples. The present paper provides a more sophisticated NMR investigation of the these materials. On heavily doped (33.3 at.%) solvent-mixed samples, {sup 27}Al Magic Angle Spinning (MAS) NMR {sup 27}Al multiple quantum MAS (MQMAS) indicates the presence of an oxide layer of Al{sub 2}O{sub 3} on the surfaces of potentially bulk nanocrystalline Ti, nanocrystalline TiAl{sub 3}, and/or metallic aluminum. The {sup 1}H MAS NMR data also indicate the possible coordination of aluminum with the oxygen atom in the THF. On heavily doped samples that were mechanically milled, {sup 27}Al MAS NMR and static NMR confirms the presence of TiAl{sub 3}. In addition, the {sup 1}H MAS NMR and {sup 1}H spin-lattice relaxation (T{sub 1}) measurements are consistent with the presence of TiH{sub 2}. These results are in agreement with recent …
Date: May 26, 2005
Creator: Herberg, J; Maxwell, R & Majzoub, E
System: The UNT Digital Library
3D-printed and injection molded polymer matrix composites with 2D layered materials (open access)

3D-printed and injection molded polymer matrix composites with 2D layered materials

This article reports on a study where 2D TMDs (MoS₂ and WS₂) and the 3D allotrope of carbon and graphite were incorporated into acrylonitrile butadiene styrene (ABS) and polyethylene terephthalate glycol (PETG) matrices in order to form polymer matrix composites (PMCs). The multipronged analysis described in this study was motivated by the purpose to fuse together topics of low-cost, additive manufacturing with 2D layered materials, and studying their ensuing mechanical and tribological properties.
Date: June 26, 2020
Creator: Gamboa, Gerardo; Mazumder, Sangram; Hnatchuk, Nathalie; Catalan Gonzalez, Jorge Alfredo; Cortes, Damaris; Chen, Ikang et al.
System: The UNT Digital Library
3D WAVE PROPAGATION AND SITE EFFECTS IN THE HUMBOLDT BAY AREA USING STRONG GROUND MOTION RECORDS FROM THE M6.5 2010 FERNDALE EARTHQUAKE. (open access)

3D WAVE PROPAGATION AND SITE EFFECTS IN THE HUMBOLDT BAY AREA USING STRONG GROUND MOTION RECORDS FROM THE M6.5 2010 FERNDALE EARTHQUAKE.

None
Date: September 26, 2012
Creator: Pitarka, Arben; Thio, Hong Kie & Somerville, Paul G.
System: The UNT Digital Library
800MHz Crab Cavity Conceptual Design For the LHC Upgrade (open access)

800MHz Crab Cavity Conceptual Design For the LHC Upgrade

In this paper, we present an 800 MHz crab cavity conceptual design for the LHC upgrade. The cell shape is optimized for lower maximum peak surface fields as well as higher transverse R/Q. A compact coax-to-coax coupler scheme is proposed to damp the LOM/SOM modes. A two-stub antenna with a notch filter is used as the HOM coupler to damp the HOM modes in the horizontal plane and rejects the operating mode at 800MHz. Multipacting (MP) simulations show that there are strong MP particles at the disks. Adding grooves along the short axis without changing the operating mode's RF characteristics can suppress the MP activities. Possible input coupler configurations are discussed.
Date: May 26, 2009
Creator: Xiao, Liling; Li, Zenghai; Ng, Cho-Kuen; Seryi, Andrei & /SLAC
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
Ab Initio Many-Body Calculations Of n-3H, n-4He, p-3,4He, And n-10Be Scattering (open access)

Ab Initio Many-Body Calculations Of n-3H, n-4He, p-3,4He, And n-10Be Scattering

We develop a new ab initio many-body approach capable of describing simultaneously both bound and scattering states in light nuclei, by combining the resonating-group method with the use of realistic interactions, and a microscopic and consistent description of the nucleon clusters. This approach preserves translational symmetry and Pauli principle. We present phase shifts for neutron scattering on {sup 3}H, {sup 4}He and {sup 10}Be and proton scattering on {sup 3,4}He, using realistic nucleon-nucleon potentials. Our A = 4 scattering results are compared to earlier ab initio calculations. We demonstrate that a proper treatment of the coupling to the n-{sup 10}Be continuum is essential to explain the parity-inverted ground state in {sup 11}Be.
Date: March 26, 2008
Creator: Quaglioni, S & Navratil, P
System: The UNT Digital Library
Ab initio study of low-energy electron collisions withtertafluoroethene, C2F4 (open access)

Ab initio study of low-energy electron collisions withtertafluoroethene, C2F4

We report the results of variational calculations of elastic electron scattering by tetrafluoroethene, C{sub 2}F{sub 4}, with incident electron energies ranging from 0.5 to 20 eV, using the complex Kohn method and effective core potentials. These are the first fully calculations to reproduce experimental angular differential cross sections at energies below 10 eV. Low-energy electron scattering by C{sub 2}F{sub 4} is sensitive to the inclusion of electronic correlation and target-distortion effects. We therefore present results that describe the dynamic polarization of the target by the incident electron. The calculated cross sections are compared with recent experimental measurements.
Date: April 26, 2004
Creator: Trevisan, C. S.; Orel, A. E. & Rescigno, Thomas N.
System: The UNT Digital Library
Aberrant Salience Inventory: A meta-analysis to investigate its psychometric properties and identify screening cutoff scores (open access)

Aberrant Salience Inventory: A meta-analysis to investigate its psychometric properties and identify screening cutoff scores

Article describes how the Aberrant Salience Inventory (ASI) is a useful tool to measure salience abnormalities among the general population. The authors claim that there is strong clinical and scientific evidence that salience alteration is linked to psychosis.
Date: May 26, 2023
Creator: Merola, Giuseppe Pierpaolo; Boy, Ottone Baccaredda; Fascina, Isotta; Pecoraro, Vincenzo; Falone, Andrea; Patti, Andrea et al.
System: The UNT Digital Library
Abrupt onset of a second energy gap at the superconducting transition of underdoped Bi2212 (open access)

Abrupt onset of a second energy gap at the superconducting transition of underdoped Bi2212

he superconducting gap--an energy scale tied to the superconducting phenomena--opens on the Fermi surface at the superconducting transition temperature (Tc) in conventional BCS superconductors. In underdoped high-Tc superconducting copper oxides, a pseudogap (whose relation to the superconducting gap remains a mystery) develops well above Tc (refs 1, 2). Whether the pseudogap is a distinct phenomenon or the incoherent continuation of the superconducting gap above Tc is one of the central questions in high-Tc research3, 4, 5, 6, 7, 8. Although some experimental evidence suggests that the two gaps are distinct9, 10, 11, 12, 13, 14, 15, 16, 17, 18, this issue is still under intense debate. A crucial piece of evidence to firmly establish this two-gap picture is still missing: a direct and unambiguous observation of a single-particle gap tied to the superconducting transition as function of temperature. Here we report the discovery of such an energy gap in underdoped Bi2Sr2CaCu2O8+delta in the momentum space region overlooked in previous measurements. Near the diagonal of Cu?O bond direction (nodal direction), we found a gap that opens at Tc and has a canonical (BCS-like) temperature dependence accompanied by the appearance of the so-called Bogoliubov quasi-particles, a classical signature of superconductivity. This is …
Date: May 26, 2007
Creator: Hussain, Zahid; Lee, W. S.; Vishik, I. M.; Tanaka, K.; Lu, D. H.; Sasagawa, T. et al.
System: The UNT Digital Library
Absolute and Comparison Techniques for Calibrating Shock Pickups; Frequency Limitations for Shock Motion Measurements - Extracted from Minutes (open access)

Absolute and Comparison Techniques for Calibrating Shock Pickups; Frequency Limitations for Shock Motion Measurements - Extracted from Minutes

This report addresses the absolute calibration, a technique used for calibrating shock pickups. This technique can be used for an applied motion regardless of its shape.
Date: August 26, 1963
Creator: Bouche, R. R.
System: The UNT Digital Library
Absorptance Measurements of Optical Coatings - A Round Robin (open access)

Absorptance Measurements of Optical Coatings - A Round Robin

An international round robin study was conducted on the absorption measurement of laser-quality coatings. Sets of optically coated samples were made by a ''reactive DC magnetron'' sputtering and an ion beam sputtering deposition process. The sample set included a high reflector at 514 nm and a high reflector for the near infrared (1030 to 1318 nm), single layers of silicon dioxide, tantalum pentoxide, and hafnium dioxide. For calibration purposes, a sample metalized with hafnium and an uncoated, superpolished fused silica substrate were also included. The set was sent to laboratory groups for absorptance measurement of these coatings. Whenever possible, each group was to measure a common, central area and another area specifically assigned to the respective group. Specific test protocols were also suggested in regards to the laser exposure time, power density, and surface preparation.
Date: October 26, 2000
Creator: Chow, R; Taylor, J R; Wu, Z L; Boccara, C A; Broulik, U; Commandre, M et al.
System: The UNT Digital Library
Accelerated reliability testing of Cu-Al bimetallic contact by a micropattern corrosion testing platform for wire bond device application (open access)

Accelerated reliability testing of Cu-Al bimetallic contact by a micropattern corrosion testing platform for wire bond device application

This article presents a novel method of in-situ investigation of the device corrosion process to capture the real time mechanistic information not obtained in standard reliability testing.
Date: March 26, 2021
Creator: Ashok Kumar, Goutham Isaac; Alptekin, John; Caperton, Joshua; Salunke, Ashish & Chyan, Oliver Ming-Ren
System: The UNT Digital Library
Acceleration of compact toroid plasma rings for fusion applications (open access)

Acceleration of compact toroid plasma rings for fusion applications

We describe experimental results for a new type of collective accelerator based on magnetically confined compact torus (CT) plasma rings and discuss applications to both inertial and magnetic fusion. We have demonstrated the principle of CT acceleration in the RACE device with acceleration of 0.5 mg ring masses to 400 km/s and 0.02 mg ring masses to 1400 km/s at greater than or equal to30% efficiency. Scaling the CT accelerator to the multi-megajoule level could provide an efficient, economical driver for inertial fusion (ICF) or magnetically insulated inertial fusion. Efficient conversion to x-rays for driving hohlraum-type ICF targets has been modeled using a radiation-hydrodynamics code. At less demanding conditions than required for ICF, a CT accelerator can be applied to fueling and current drive in tokamaks. Fueling is accomplished by injecting CTs at the required rate to sustain the particle inventory and at a velocity sufficient to penetrate to the magnetic axis before CT dissolution. Current drive is a consequence of the magnetic helicity content of the CT, which is approximately conserved during reconnection of the CT fields with the tokamak. Major areas of uncertainty in CT fueling and current drive concern the mechanism by which CTs will stop in …
Date: August 26, 1988
Creator: Hartman, C. W.; Barr, W. L.; Eddleman, J. L.; Gee, M.; Hammer, J. H.; Ho, S. K. et al.
System: The UNT Digital Library