Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) for Elemental Analysis (open access)

Prompt Gamma-Ray Neutron Activation Analysis (PGNAA) for Elemental Analysis

This research project was to improve the prompt gamma-ray neutron activation analysis (PGNAA) measurement approach for bulk analysis, oil well logging, and small sample thermal enutron bean applications.
Date: April 11, 2006
Creator: Gardner, Robin P.
Object Type: Report
System: The UNT Digital Library
Observations on an aileron-flutter instability encountered on a 45 degree swept-back wing in transonic and supersonic flight (open access)

Observations on an aileron-flutter instability encountered on a 45 degree swept-back wing in transonic and supersonic flight

Report presenting a flight test of a supersonic research pilotless aircraft in which large-amplitude aileron oscillations, most likely aileron compressibility flutter, were encountered in the transonic and supersonic speed ranges. Results regarding power-on flight and coasting flight are provided.
Date: April 11, 1947
Creator: Pitkin, Marvin; Gardner, William N. & Curfman, Howard J., Jr.
Object Type: Report
System: The UNT Digital Library
An adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium (open access)

An adaptive optics package designed for astronomical use with a laser guide star tuned to an absorption line of atomic sodium

We present the design and implementation of a very compact adaptive optic system that senses the return light from a sodium guide-star and controls a deformable mirror and a pointing mirror to compensate atmospheric perturbations in the wavefront. The deformable mirror has 19 electrostrictive actuators and triangular subapertures. The wavefront sensor is a Hartmann sensor with lenslets on triangular centers. The high-bandwidth steering mirror assembly incorporates an analog controller that samples the tilt with an avalanche photodiode quad cell. An {line_integral}/25 imaging leg focuses the light into a science camera that can either obtain long-exposure images or speckle data. In laboratory tests overall Strehl ratios were improved by a factor of 3 when a mylar sheet was used as an aberrator. The crossover frequency at unity gain is 30 Hz.
Date: April 11, 1994
Creator: Salmon, J. T.; Avicola, K. & Brase, J. M.
Object Type: Article
System: The UNT Digital Library
Revised Thermal Analysis of LANL Ion Exchange Column (open access)

Revised Thermal Analysis of LANL Ion Exchange Column

This document updates a previous calculation of the temperature distributions in a Los Alamos National Laboratory (LANL) ion exchange column.1 LANL operates two laboratory-scale anion exchange columns, in series, to extract Pu-238 from nitric acid solutions. The Defense Nuclear Facilities Safety Board has requested an updated analysis to calculate maximum temperatures for higher resin loading capacities obtained with a new formulation of the Reillex HPQ anion exchange resin. The increased resin loading capacity will not exceed 118 g plutonium per L of resin bed. Calculations were requested for normal operation of the resin bed at the minimum allowable solution feed rate of 30 mL/min and after an interruption of flow at the end of the feed stage, when one of the columns is fully loaded. The object of the analysis is to demonstrate that the decay heat from the Pu-238 will not cause resin bed temperatures to increase to a level where the resin significantly degrades. At low temperatures, resin bed temperatures increase primarily due to decay heat. At {approx}70 C a Low Temperature Exotherm (LTE) resulting from the reaction between 8-12 M HNO{sub 3} and the resin has been observed. The LTE has been attributed to an irreversible oxidation …
Date: April 11, 2006
Creator: Laurinat, J
Object Type: Report
System: The UNT Digital Library
Amplitude Analysis and Measurement of the Time-dependent CP Asymmetry of B0 to KsKsKs Decays (open access)

Amplitude Analysis and Measurement of the Time-dependent CP Asymmetry of B0 to KsKsKs Decays

We present the first results on the Dalitz-plot structure and improved measurements of the time-dependent CP-violation parameters of the process B{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0} obtained using 468 x 10{sup 6} B{bar B} decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The Dalitz-plot structure is probed by a time-integrated amplitude analysis that does not distinguish between B{sup 0} and {bar B}{sup 0} decays. We measure the total inclusive branching fraction {Beta}(B{sup 0} {yields} K{sub S}{sup 0}K{sub S}{sup 0}K{sub S}{sup 0}) = (6.19 {+-} 0.48 {+-} 0.15 {+-} 0.12) x 10{sup -6}, where the first uncertainty is statistical, the second is systematic, and the third represents the Dalitz-plot signal model dependence. We also observe evidence for the intermediate resonant states f{sub 0}(980), f{sub 0}(1710), and f{sub 2}(2010). Their respective product branching fractions are measured to be (2.70{sub -1.19}{sup +1.25} {+-} 0.36 {+-} 1.17) x 10{sup -6}, (0.50{sub -0.24}{sup +0.46} {+-} 0.04 {+-} 0.10) x 10{sup -6}, and (0.54{sub -0.20}{sup +0.21} {+-} 0.03 {+-} 0.52) x 10{sup -6}. Additionally, we determine the mixing-induced CP-violation parameters to be S = -0.94{sub -0.21}{sup +0.24} {+-} 0.06 and C = -0.17 {+-} 0.18 {+-} …
Date: April 11, 2012
Creator: Lees, J. P.
Object Type: Article
System: The UNT Digital Library
Hanford Site Groundwater Monitoring: Setting, Sources, and Methods (open access)

Hanford Site Groundwater Monitoring: Setting, Sources, and Methods

Hanford Site Groundwater Monitoring: Setting, Sources, and Methods
Date: April 11, 2000
Creator: Hartman, Mary J.
Object Type: Report
System: The UNT Digital Library
Hanford Site groundwater monitoring: Setting, sources and methods (open access)

Hanford Site groundwater monitoring: Setting, sources and methods

Groundwater monitoring is conducted on the Hanford Site to meet the requirements of the Resource Conservation and Recovery Act of 1976 (RCRA); Comprehensive Environmental Response, Compensation, and Liability Act of 1980 (CERCLA); U.S. Department of Energy (DOE) orders; and the Washington Administrative Code. Results of monitoring are published annually (e.g., PNNL-11989). To reduce the redundancy of these annual reports, background information that does not change significantly from year to year has been extracted from the annual report and published in this companion volume. This report includes a description of groundwater monitoring requirements, site hydrogeology, and waste sites that have affected groundwater quality or that require groundwater monitoring. Monitoring networks and methods for sampling, analysis, and interpretation are summarized. Vadose zone monitoring methods and statistical methods also are described. Whenever necessary, updates to information contained in this document will be published in future groundwater annual reports.
Date: April 11, 2000
Creator: Hartman, M.J.
Object Type: Report
System: The UNT Digital Library
Extragalactic Background Light from Hierarchical Galaxy Formation: Gamma-ray Attenuation up to the Epoch of Cosmic Reionization and the First Stars (open access)

Extragalactic Background Light from Hierarchical Galaxy Formation: Gamma-ray Attenuation up to the Epoch of Cosmic Reionization and the First Stars

None
Date: April 11, 2013
Creator: Inoue, Yoshiyuki; /KIPAC, Menlo Park /SLAC; Inoue, Susumu; /Heidelberg, Max Planck Inst. /Tokyo U., ICRR; Kobayashi, Masakazu A.R.; U., /Ehime et al.
Object Type: Article
System: The UNT Digital Library
Delta f Monte Carlo Calculation Of Neoclassical Transport In Perturbed Tokamaks (open access)

Delta f Monte Carlo Calculation Of Neoclassical Transport In Perturbed Tokamaks

Non-axisymmetric magnetic perturbations can fundamentally change neoclassical transport in tokamaks by distorting particle orbits on deformed or broken flux surfaces. This so-called non-ambipolar transport is highly complex, and eventually a numerical simulation is required to achieve its precise description and understanding. A new delta#14;f particle code (POCA) has been developed for this purpose using a modi ed pitch angle collision operator preserving momentum conservation. POCA was successfully benchmarked for neoclassical transport and momentum conservation in axisymmetric con guration. Non-ambipolar particle flux is calculated in the non-axisymmetric case, and results show a clear resonant nature of non-ambipolar transport and magnetic braking. Neoclassical toroidal viscosity (NTV) torque is calculated using anisotropic pressures and magnetic fi eld spectrum, and compared with the generalized NTV theory. Calculations indicate a clear #14;B2 dependence of NTV, and good agreements with theory on NTV torque pro les and amplitudes depending on collisionality.
Date: April 11, 2012
Creator: Kimin Kim, Jong-Kyu Park, Gerrit Kramer and Allen H. Boozer
Object Type: Report
System: The UNT Digital Library
Dark Matter and Baryons in the Most X-ray Luminous and Merging Galaxy Cluster RX (open access)

Dark Matter and Baryons in the Most X-ray Luminous and Merging Galaxy Cluster RX

None
Date: April 11, 2008
Creator: Bradac, Marusa; Schrabback, Tim; Erben, Thomas; McCourt, Michael; Million, Evan; Mantz, Adam et al.
Object Type: Article
System: The UNT Digital Library
Texas Register, Volume 11, Number 28, Pages 1597-1631, April 11, 1986 (open access)

Texas Register, Volume 11, Number 28, Pages 1597-1631, April 11, 1986

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: April 11, 1986
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History