Chord Distributions of a Spherical Shell (open access)

Chord Distributions of a Spherical Shell

None
Date: June 25, 2004
Creator: Chang, B.
Object Type: Report
System: The UNT Digital Library
The Effects of Oil Shocks on the Economy: A Review of the Empirical Evidence (open access)

The Effects of Oil Shocks on the Economy: A Review of the Empirical Evidence

This report surveys the econemetric literature on oil shocks to provide quantitative estimates of how large an effect oil price changes have on economic activity.
Date: June 25, 2004
Creator: Labonte, Marc
Object Type: Report
System: The UNT Digital Library
Microsecond Microfluidic Mixing for Investigation of Protein Folding Kinetics (open access)

Microsecond Microfluidic Mixing for Investigation of Protein Folding Kinetics

We have developed and characterized a mixer to study the reaction kinetics of protein folding on a microsecond timescale. The mixer uses hydrodynamic focusing of pressure-driven flow in a microfluidic channel to reduce diffusion times as first demonstrated by Knight et al.[1]. Features of the mixer include 1 {micro}s mixing times, sample consumptions of order 1 nl/s, loading sample volumes on the order of microliters, and the ability to manufacture in fused silica for compatibility with most spectroscopic methods.
Date: June 25, 2003
Creator: Hertzog, D E; Santiago, J G & Bakajin, O
Object Type: Article
System: The UNT Digital Library
Space Launch Vehicles: Government Activities, Commercial Competition, and Satellite Exports (open access)

Space Launch Vehicles: Government Activities, Commercial Competition, and Satellite Exports

This report includes information regarding space launch vehicles. Launch vehicle policy, vehicle programs and issues, and the U.S. commercial launch service industry are among topics discussed in this report.
Date: June 25, 2004
Creator: Smith, Marcia S.
Object Type: Report
System: The UNT Digital Library
Child Pornography: Constitutional Principles and Federal Statutes (open access)

Child Pornography: Constitutional Principles and Federal Statutes

This report contains the constitutional principles and federal statutes of child pornography.
Date: June 25, 2003
Creator: Cohen, Henry
Object Type: Report
System: The UNT Digital Library
A Supernodal Approach to Incomplete LU Factorization with Partial Pivoting (open access)

A Supernodal Approach to Incomplete LU Factorization with Partial Pivoting

We present a new supernode-based incomplete LU factorization method to construct a preconditioner for solving sparse linear systems with iterative methods. The new algorithm is primarily based on the ILUTP approach by Saad, and we incorporate a number of techniques to improve the robustness and performance of the traditional ILUTP method. These include the new dropping strategies that accommodate the use of supernodal structures in the factored matrix. We present numerical experiments to demonstrate that our new method is competitive with the other ILU approaches and is well suited for today's high performance architectures.
Date: June 25, 2009
Creator: Li, Xiaoye Sherry & Shao, Meiyue
Object Type: Article
System: The UNT Digital Library
Thorough characterization of a EUV mask (open access)

Thorough characterization of a EUV mask

We reported that we were successful in our 45nm technology node device demonstration in February 2008 and 22nm node technology node device patterning in February 2009 using ASML's Alpha Demo Tool (ADT). In order to insert extreme ultraviolet (EUV) lithography at the 15nm technology node and beyond, we have thoroughly characterized one EUV mask, a so-called NOVACD mask. In this paper, we report on three topics, The first topic is an analysis of line edge roughness (LER) using a mask Scanning Electron Microscope (SEM), an Atomic Force Microscope (AFM) and the Actinic Inspection Tool (AIT) to compare resist images printed with the ASML ADT. The results of the analysis show a good correlation between the mask AFM and the mask SEM measurements, However, the resist printing results for the isolated space patterns are slightly different. The cause ofthis discrepancy may be resist blur, image log slope and SEM image quality and so on. The second topic is an analysis of mask topography using an AFM and relative reflectivity of mirror and absorber surface using the AIT, The AFM data show 6 and 7 angstrom rms roughness for mirror and absorber, respectively. The reflectivity measurements show that the mirror reflects EUV …
Date: June 25, 2009
Creator: Mizuno, H.; McIntyre, G.; Koay, C.-W.; Burkhardt, M.; He, L.; Hartley, J. et al.
Object Type: Article
System: The UNT Digital Library
Jack Rabbit Pretest 2021E PT3 Photonic Doppler Velocimetry Data Volume 3 Section 1 (open access)

Jack Rabbit Pretest 2021E PT3 Photonic Doppler Velocimetry Data Volume 3 Section 1

The Jack Rabbit Pretest (PT) 2021E PT3 was fired on March 12, 2008 at the Contained Firing Facility, Site 300, Lawrence Livermore National Laboratory. This experiment is part of an effort to determine the properties of LX-17 in a regime where corner-turning behavior and dead-zone formation are not well understood. Photonic Doppler Velocimetry (PDV) measured diagnostic plate velocities confirming the presence of a persistent LX-17 dead-zone formation and the resultant impulse gradient applied under the diagnostic plate. The Jack Rabbit Pretest 2021E PT3, 120 millimeter diameter experiment returned data on all eight PDV probes. The probes measured on the central axis and at 10, 20, 25, 30, 35, 40, 50 millimeters from the central axis. The experiment was shot at an ambient room temperature of 65 degrees Fahrenheit. The earliest PDV signal extinction was 41.7 microseconds at 30 millimeters. The latest PDV signal extinction time was 65.0 microseconds at 10 millimeters. The measured velocity ranged from meters per second to thousands of meters per second. First detonation wave induced jump-off was measured at 40 millimeters at 10.9 microseconds. The PDV data provided an unambiguous indication of dead-zone formation and an impulse gradient applied to the diagnostic plate. The central axis …
Date: June 25, 2008
Creator: Hart, M. M.; Strand, O. T.; Bosson, S. T.; Bonner, R. A. & Hester, D. M.
Object Type: Report
System: The UNT Digital Library
The Use of Weighting in Periodicity Searches in All-Sky Monitor Data: Applications to the GLAST LAT (open access)

The Use of Weighting in Periodicity Searches in All-Sky Monitor Data: Applications to the GLAST LAT

The light curves produced by all-sky monitors, such as the Rossi X-ray Timing Explorer All-Sky Monitor and the Swift Burst Alert Telescope (BAT), generally have non-uniform error bars. In searching for periodic modulation in this type of data using power spectra it can be important to use appropriate weighting of data points to achieve the best sensitivity. It was recently demonstrated that for Swift BAT data a simple weighting scheme can actually sometimes reduce the sensitivity of the power spectrum depending on source brightness. Instead, a modified weighting scheme, based on the Cochran semi-weighted mean, gives improved results independent of source brightness. We investigate the benefits of weighting power spectra in period searches using simulated GLAST LAT observations of {gamma}-ray binaries.
Date: June 25, 2009
Creator: Corbet, Robin & Dubois, Richard
Object Type: Article
System: The UNT Digital Library
Composition and Technical Basis for K Basin Settler Sludge Simulant for Inspection, Retrieval, and Pump Testing (open access)

Composition and Technical Basis for K Basin Settler Sludge Simulant for Inspection, Retrieval, and Pump Testing

This report provides the formulation and technical basis for a K Basin Settler Tank Sludge simulant that will be used by the K Basin Closure Project (KBC) to test and develop equipment/approaches for Settler Tank sludge level measurement and retrieval in a mock-up test system of the actual Settler Tanks. The sludge simulant may also be used to demonstrate that the TOYO high pressure positive displacement pump design (reversing valves and hollow balls) is suitable for transfer of Settler Tank sludge from the K West (KW) Basin to the Cold Vacuum Drying Facility (CVDF) (~500 ft). As requested the by the K Basins Sludge Treatment Project (STP) the simulant is comprised of non-radioactive (and non-uranium) constituents.
Date: June 25, 2007
Creator: Schmidt, Andrew J. & Zacher, Alan H.
Object Type: Report
System: The UNT Digital Library
Stochastic Ion Heating in a Field-reversed Configuration Geometry by Rotating Magnetic Fields (open access)

Stochastic Ion Heating in a Field-reversed Configuration Geometry by Rotating Magnetic Fields

Ion heating by application of rotating magnetic fields (RMF) to a prolate field-reversed configuration(FRC) is explored by analytical and numerical techniques. For odd-parity RMF (RMFo), perturbation analysis shows ions in figure-8 orbits gain energy at resonances of the RMFo frequency, ωR, with the figure-8 orbital frequency, ω. Since figure-8 orbits tend to gain the most energy from the RMF and are unlikely to escape in the cusp region (where most losses occur), they are optimal candidates for rapid stochastic heating, as compared to cyclotron and betatron orbits. Comparisons are made between heating caused by even- and odd-parity RMFs and between heating in currently operating and in reactor-scale FRC devices.
Date: June 25, 2007
Creator: S.A. Cohen, A.S. Landsman, and A.H. Glasser
Object Type: Report
System: The UNT Digital Library
Measurement of the angle alpha at BABAR (open access)

Measurement of the angle alpha at BABAR

The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.
Date: June 25, 2009
Creator: Perez, A.
Object Type: Article
System: The UNT Digital Library
Evaluation of Exothermic Reactions from Bulk-Vitrification Melter Feeds Containing Cellulose (open access)

Evaluation of Exothermic Reactions from Bulk-Vitrification Melter Feeds Containing Cellulose

PNNL has demonstrated that cellulose effectively reduces the amount of molten ionic salt during Bulk Vitrification of simulated Hanford Low Level Waste (LLW). To address concerns about the potential reactivity of cellulose-LLW, PNNL used thermogravimetric analysis, differential thermal analysis, and accelerating rate calorimetry to determine in these preliminary studies that these mixtures will support a self-sustaining reaction if heated to 110°C at adiabatic conditions. Additional testing is recommended.
Date: June 25, 2007
Creator: Scheele, Randall D.; McNamara, Bruce K.; Bagaasen, Larry M.; Bos, Stanley J.; Kozelisky, Anne E. & Berry, Pam
Object Type: Report
System: The UNT Digital Library
Structural Analyses of Fuel Casks Subjected to Bolt Preload, Internal Pressure and Sequential Dynamic Impacts (open access)

Structural Analyses of Fuel Casks Subjected to Bolt Preload, Internal Pressure and Sequential Dynamic Impacts

Large fuel casks subjected to the combined loads of closure bolt tightening, internal pressure and sequential dynamic impacts present challenges when evaluating their performance in the Hypothetical Accident Conditions (HAC) specified in the Code of Federal Regulations Title 10 Part 71 (10CFR71). Testing is often limited by cost, difficulty in preparing test units and the limited availability of facilities which can carry out such tests. In the past, many casks were evaluated without testing by using simplified analytical methods. In addition, there are no realistic analyses of closure bolt stresses for HAC conditions reported in the open literature. This paper presents a numerical technique for analyzing the accumulated damages of a large fuel cask caused by the sequential loads of the closure bolt tightening and the internal pressure as well as the drop and crash dynamic loads. The bolt preload and the internal pressure are treated as quasi-static loads so that the finite element method with explicit numerical integration scheme based on the theory of wave propagation can be applied. The dynamic impacts with short durations such as the 30-foot drop and the 40-inch puncture for the hypothetical accident conditions specified in 10CFR71 are also analyzed by using the finite-element …
Date: June 25, 2009
Creator: Wu, T.
Object Type: Article
System: The UNT Digital Library
Factors affecting the indoor concentrations of carbonaceous aerosols of outdoor origin (open access)

Factors affecting the indoor concentrations of carbonaceous aerosols of outdoor origin

A field study was conducted in an unoccupied single story residence in Clovis, California to provide data to address issues important to assess the indoor exposure to particles of outdoor origin. Measurements of black and organic carbonaceous aerosols were performed using a variety of methods, resulting in both near real-time measurements as well as integrated filter based measurements. Comparisons of the different measurement methods show that it is crucial to account for gas phase adsorption artifacts when measuring organic carbon (OC). Measured concentrations affected by the emissions of organic compounds sorbed to indoor surfaces imply a higher degree of infiltration of outdoor organic carbon aerosols into the indoor environment for our unoccupied house. Analysis of the indoor and outdoor data for black carbon (BC) aerosols show that, on average, the indoor concentration of black carbon aerosols behaves in a similar manner to sulfate aerosols. In contrast, organic carbon aerosols are subject to chemical transformations indoors that, for our unoccupied home, resulted in lower indoor OC concentrations than would be expected by physical loss mechanisms alone. These results show that gas to particle partitioning of organic compounds, as well as gas to surface interactions within the residence, are an important process …
Date: June 25, 2007
Creator: Lunden, Melissa M.; Kirchstetter, Thomas W.; Thatcher, Tracy L.; Hering, Susanne V. & Brown, Nancy J.
Object Type: Article
System: The UNT Digital Library
REVERSIBLE AND IRREVERSIBLE PASSIVATION OF A LA-NI-AL ALLOY (open access)

REVERSIBLE AND IRREVERSIBLE PASSIVATION OF A LA-NI-AL ALLOY

This paper seeks to explore some of the effects of passivating a LaNi{sub 4.25}Al{sub 0.75} sample by air oxidation under controlled conditions. Passivation of this metal hydride alloy seems to have two distinct regimes. The first occurs with air oxidation at 80 C and 20 C. It is characterized by complete reversibility upon hydrogen readsorption, although said readsorption is hindered substantially at room temperature, requiring the material to be heated to produce the reactivation. The second regime is illustrated by 130 C air oxidation and is characterized by irreversible loss of hydrogen absorption capacity. This passivation does not hinder hydrogen readsorption into the remaining hydride material.
Date: June 25, 2009
Creator: Shanahan, K. & Klein, J.
Object Type: Article
System: The UNT Digital Library
Corrosive Resistant Diamond Coatings for the Acid Based Thermo-Chemical Hydrogen Cycles (open access)

Corrosive Resistant Diamond Coatings for the Acid Based Thermo-Chemical Hydrogen Cycles

This project was designed to test diamond, diamond-like and related materials in environments that are expected in thermochemical cycles. Our goals were to build a High Temperature Corrosion Resistance (HTCR) test stand and begin testing the corrosive properties of barious materials in a high temperature acidic environment in the first year. Overall, we planned to test 54 samples each of diamond and diamond-like films (of 1 cm x 1 cm area). In addition we use a corrosion acceleration method by treating the samples at a temperature much larger than the expected operating temperature. Half of the samples will be treated with boron using the FEDOA process.
Date: June 25, 2009
Creator: Prelas, Mark A.
Object Type: Report
System: The UNT Digital Library
TANK FARM INTERIM SURFACE BARRIER MATERIALS AND RUNOFF ALTERNATIVES STUDY (open access)

TANK FARM INTERIM SURFACE BARRIER MATERIALS AND RUNOFF ALTERNATIVES STUDY

This report identifies candidate materials and concepts for interim surface barriers in the single-shell tank farms. An analysis of these materials for application to the TY tank farm is also provided.
Date: June 25, 2009
Creator: MJ, HOLM
Object Type: Report
System: The UNT Digital Library
Acceleration of Electrons With the Racetrack Non-Scaling Ffag for E-Rhic (open access)

Acceleration of Electrons With the Racetrack Non-Scaling Ffag for E-Rhic

The future relativistic electron hadron collider: e-RHIC requires acceleration of electrons to 10 GeV. In the case that the super conducting linac is selected for acceleration, an energy recovery scheme is required. We propose to study a possibility of using the non-scaling Fixed-Field Gradient-Accelerator (NS-FFAG) for different energies. The beam will be accelerated by the superconducting linac at the top of the sine function, brought back to the front of the linac by the non-scaling FFAG and repeating this few times until the total energy of 20 GeV is reached. After collisions the beam is brought back by the non-scaling FFAG and decelerated (on the lower RF phase) in the same sequence but in the reverse order. Conventional and non-conventional beam dynamic issues will be discussed, like the transit time matching effect and the time of flight adjustments.
Date: June 25, 2007
Creator: Trbojevic, D.; Blaskiewicz, M.; Litvinenko, V.; Ptitsyn, V. & Roser, T.
Object Type: Article
System: The UNT Digital Library
Design of a Thin Quadrupole to Be Used in the Ags Synchrotron (open access)

Design of a Thin Quadrupole to Be Used in the Ags Synchrotron

The Alternating Gradient Synchrotron (AGS) employs two partial helical snakes[l] to preserve the polarization of the proton beam during acceleration. In order to compensate for the focusing effect of the partial helical snakes on the beam optics in the AGS during acceleration of the beam, we introduced eight quadrupoles in straight sections of the AGS at the proximity of the partial snakes. At injection energies, the strength of each quad is set at a high value, and is ramped down to zero as the effect of the snakes diminishes by the square of beam's rigidity. Four of the eight compensation quadrupoles had to be placed in very short straight sections -30 cm in length, therefore the quadruples had be thin with an overall length of less than 30 cm. In this paper we will discus: (a) the mechanical and magnetic specifications of the ''thin'' quadrupole. (b) the method to minimize the strength of the dodecapole harmonic, (c) the method to optimize the thickness of the laminations that the magnet iron is made, (d) mechanical tolerances of the magnet, (e) comparison of the measured and calculated magnetic multipoles of the quadrupole.
Date: June 25, 2007
Creator: Tsoupas, N.; Ahrens, L.; Alforque, R.; Bai, M.; Brown, K.; Courant, E. et al.
Object Type: Article
System: The UNT Digital Library
The RHIC Hydrogen Jet Luminescence Monitor (open access)

The RHIC Hydrogen Jet Luminescence Monitor

A hydrogen jet polarimeter was developed for the RHIC accelerator to improve the process of measuring polarization. Particle beams intersecting with gas molecules can produce light by the process known as luminescence. This light can then be focused, collected, and processed giving important information such as size, position, emittance, motion, and other parameters. The RHIC hydrogen jet polarimeter was modified in 2005 with specialized optics, vacuum windows, light transport, and a new camera system making it possible to monitor the luminescence produced by polarized protons intersecting the hydrogen beam. This paper describes the configuration and preliminary measurements taken using the RHIC hydrogen jet polarimeter as a luminescence monitor.
Date: June 25, 2007
Creator: Russo, T.; Bellavia, S.; Gassner, D.; Thieberger, P.; Trbojevic, D. & Tsang, T.
Object Type: Article
System: The UNT Digital Library
Emittance Compensation for Magnetized Beams (open access)

Emittance Compensation for Magnetized Beams

Emittance compensation is a well established technique for minimizing the emittance of an electron beam from a RF photo-cathode gun. Longitudinal slices of a bunch have a small emittance, but due to the longitudinal charge distribution of the bunch and time dependent RF fields they are not focused in the same way, so that the direction of their phase ellipses diverges in phase space and the projected emittance is much larger. Emittance compensation reverses the divergence. At the location where the slopes of the phase ellipses coincide the beam is accelerated, so that the space charge forces are reduced. A recipe for emittance compensation is given in. For magnetized beams (where the angular momentum is non-zero) such emittance compensation is not sufficient because variations in the slice radius lead to variations in the angular speed and therefore to an increase of emittance in the rotating game. We describe a method and tools for a compensation that includes the beam magnetization.
Date: June 25, 2007
Creator: Kewisch, J. & Chang, X.
Object Type: Article
System: The UNT Digital Library
Simulations of RHIC Coherent Stabilities Due to Wakefield and Electron Cooling (open access)

Simulations of RHIC Coherent Stabilities Due to Wakefield and Electron Cooling

The Electron cooling beam has both coherent and incoherent effects to the circulating ion beam. The incoherent longitudinal cooling could reduce the ion beam energy spread and hence cause 'over-cooling' of the ion beam. Depending on the beam densities and cooling length, the coherent interaction between the ion and electron beam could either damp or anti-damp the ion coherent motions. Using the tracking codes, TRANFT, the threshold for 'over-cooling' has been found and compared with theoretical estimation. The transverse coherent effect of electron cooling has been implemented into the codes and its effect for the bunched ion beam is shown.
Date: June 25, 2007
Creator: Wang, G. & Blaskiewicz, M.
Object Type: Article
System: The UNT Digital Library
Status of R & D energy recovery LINAC at Brookhaven National Laboratory. (open access)

Status of R & D energy recovery LINAC at Brookhaven National Laboratory.

In this paper we present status and plans for the 20-MeV R&D energy recovery linac (ERL), which is under construction at Collider Accelerator Department at BNL. The facility is based on high current (up to 0.5 A of average current) super-conducting 2.5 MeV RF gun, single-mode super-conducting 5-cell RF linac and about 20-m long return loop with very flexible lattice. The R&D ERL, which is planned for commissioning in early 2009, aims to address many outstanding questions relevant for high current, high brightness energy recovery linacs.
Date: June 25, 2007
Creator: Litvinenko, V.; Ben-Zvi, Ilan; Alduino, J. M.; Barton, D. S.; Beavis, D. & Blaskiewicz, M.
Object Type: Article
System: The UNT Digital Library