Evaluation of the {sup 4}I{sub 11/2} terminal level lifetime for several neodymium-doped laser crystals and glasses (open access)

Evaluation of the {sup 4}I{sub 11/2} terminal level lifetime for several neodymium-doped laser crystals and glasses

All models of lasing action require knowledge of the physical parameters involved, of which many can be measured or estimated. The value of the terminal level lifetime is an important parameter in modeling many high power laser systems since the terminal level lifetime can have a substantial impact on the extraction efficiency of the system. However, the values of the terminal level lifetimes for a number of important laser materials such as ND:YAG and ND:YLF are not well known. The terminal level lifetime, a measure of the time it takes for the population to drain out of the terminal (lower) lasing level, has values that can range from picoseconds to microseconds depending on the host medium, thus making it difficult to construct one definitive experiment for all materials. Until recently, many of the direct measurements of the terminal level lifetime employed complex energy extraction or gain recovery methods coupled with a numerical model which often resulted in large uncertainties in the measured lifetimes. In this report we demonstrate a novel and more accurate approach which employs a pump-probe technique to measure the terminal level lifetime of 16 neodymium-doped materials. An alternative yet indirect method, which is based on the ``Energy …
Date: April 25, 1995
Creator: Bibeau, C.
Object Type: Thesis or Dissertation
System: The UNT Digital Library
Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1995--March 1995 (open access)

Robotic weld overlay coatings for erosion control. Quarterly technical progress report, January 1995--March 1995

Research is presently being conducted to develop a criteria for selecting weld overlay coatings for erosion mitigation in Circulated Fluidized Beds. During the last two quarters tensile tests were performed at 400{degrees}C for the Ultimet, Inconel-625, 316L SS, C-22, and Stellite-6 wrought alloys. Also, the erosion tests for these materials at 400{degrees}C were completed. The results of mechanical and erosion tests are used to correlate mechanical properties of selected wrought alloys such as tensile toughness, ductility, strain hardening coefficient and yield strength to their erosion resistance at 400{degrees}C. Preliminary results of correlations between erosion resistance of wrought alloys at 400{degrees}C and their mechanical properties are presented in this progress report.
Date: April 25, 1995
Creator: Levin, B. F.; Dupont, J. N. & Marder, A. R.
Object Type: Report
System: The UNT Digital Library
Strategy for resolution of the Flammable Gas Safety Issue (open access)

Strategy for resolution of the Flammable Gas Safety Issue

The purpose of this document is to provide the general strategy for resolution of the flammable gas safety issue; it is not a detailed description of program activities. budgets and schedules. Details of the program activities have been issued (Johnson and Sherwood, 1994) and the information pertaining to budgets is provided in the FY 1995-1997 Multi-Year Work Plan for Tank Waste Remediation System (TWRS) (Program Element 1.1.1.2.02.). The key element in this strategy is to provide an understanding of the behavior of each of the Flammable Gas Watch List tanks. While a review of historical information does provide some insight, it is necessary to gather current information about the gases, behavior and nature of the waste,. and about the control systems that maintain and monitor the waste. Analysis of this information will enable TWRS to determine the best approach to place any tank in a safe condition, if it is found to be in an unsafe state.
Date: April 25, 1995
Creator: Johnson, G. D.
Object Type: Report
System: The UNT Digital Library
Annual report Rockwell International Hot Laboratory decommissioning GFY 1993 (open access)

Annual report Rockwell International Hot Laboratory decommissioning GFY 1993

OAK-B135 Annual report Rockwell International Hot Laboratory decommissioning GFY 1993
Date: April 25, 1995
Creator: Felten, L. D.
Object Type: Report
System: The UNT Digital Library
ABCASH plotting program users guide (open access)

ABCASH plotting program users guide

The Automated Bar Coding of Air Samples at Hanford (ABCASH) system provides an integrated data collection, sample tracking, and data reporting system for radioactive particulate air filter samples. The ABCASH plotting program provides a graphical trend report for ABCASH of the performance of air sample results. This document provides an operational guide for using the program. Based on sample location identifier and date range, a trend chart of the available data is generated. The trend chart shows radiological activity versus time. General indications of directional trend of the concentrations in air over time may be discerned. Comparison limit set point values are also shown as derived from the ABCASH data base.
Date: April 25, 1995
Creator: Troyer, G. L.
Object Type: Report
System: The UNT Digital Library
A MEMS-based miniature DNA analysis system (open access)

A MEMS-based miniature DNA analysis system

We detail the design and development of a miniature thermal cycling instrument for performing the polymerase chain reaction (PCR) that uses microfabricated, silicon-based reaction chambers. The MEMS-based, battery-operated instrument shows significant improvements over commercial thermal cycling instrumentation. Several different biological systems have been amplified and verified with the miniature PCR instrument including the Human Immunodeficiency Virus; both cloned and genomic DNA templates of {beta} globin; and the genetic disease, Cystic Fibrosis from human DNA. The miniaturization of a PCR thermal cycler is the initial module of a fully-integrated portable, low-power, rapid, and highly efficient bioanalytical instrument.
Date: April 25, 1995
Creator: Northrup, M.A.; Gonzalez, C. & Hadley, D.
Object Type: Article
System: The UNT Digital Library
Replacemernt of thermally produced calcined clay with chemically structured pigments and methods for the same, quarterly report, January 1, 1995-April 1, 1995 (open access)

Replacemernt of thermally produced calcined clay with chemically structured pigments and methods for the same, quarterly report, January 1, 1995-April 1, 1995

The business objective is to manufacture an economically viable chemically structured clay to replace thermally structured calcined clay. The technology will provide substantial benefit in paper coating. The structured pigment containing 90% clay and 10% TiO2 vs the loose blend of these materials as a filler for paper was evaluated. A plan to improve the permanence of the structured pigment using dual functional dispersed pigments is in place. The cationic dispersant for TiO2 will also be a binder. Spray drying will be use to fix the structure of the internally bound structured pigment.
Date: April 25, 1995
Creator: Whalen-Shaw, M.
Object Type: Report
System: The UNT Digital Library
Dysregulation of temperature and liver cytokine gene expression in immunodeficient wasted mice (open access)

Dysregulation of temperature and liver cytokine gene expression in immunodeficient wasted mice

Wasted mice bear the spontaneous autosomal recessive mutation wst/wst; this genotype is associated with weight loss beginning at 21 days of age, neurologic dysfunction, immunodeficiency at mucosal sites, and increased sensitivity to the killing effects of ionizing radiation. The pathology underlying the disease symptoms is unknown. Experiments reported here were designed to examine thermoregulation and liver expression of specific cytokines in wasted mice and in littermate and parental controls. Our experiments found that wasted mice begin to show a drop in body temperature at 21-23 days following birth, continuing until death at the age of 28 days. Concomitant with that, livers from wasted mice expressed increased amounts of mRNAs specific for cytokines IL,6 and IL-1, the acute phase reactant C-reactive protein, c-jun, and apoptosis-associated Rp-8 when compared to littermate and parental control animals. Levels of {beta}-transforming growth factor (TGF), c-fos, proliferating cell nuclear antigen (PCNA), and ornithine amino transferase (OAT) transcripts were the same in livers from wasted mice and controls. These results suggest a relationship between an acute phase reactant response in wasted mice and temperature dysregulation.
Date: April 25, 1995
Creator: Libertin, C. R.; Ling-Indeck, L.; Weaver, P.; Chang-Liu, Chin-Mei; Strezoska, V.; Heckert, B. et al.
Object Type: Report
System: The UNT Digital Library
Development of beam position monitors for heavy ion recirculators (open access)

Development of beam position monitors for heavy ion recirculators

Work is underway at the Lawrence Livermore National Laboratory to design and build a small-scale, heavy ion recirculating induction accelerator. An essential part of this design work is the development of small nonintercepting diagnostics to measure beam current and position. This paper describes some of this work, with particular emphasis on the development of a small capacitive probe beam position monitor to resolve beam position to the 100 {mu}m level in a 6 cm diameter beam pipe. Initial measured results with an 80 keV potassium ion beam are presented.
Date: April 25, 1995
Creator: Deadrick, F. J.; Barnard, J. J.; Fessenden, T. J.; Meridith, J. W. & Rintamaki, J.
Object Type: Article
System: The UNT Digital Library
Choppertron II (open access)

Choppertron II

We present experimental results of a version of the Choppertron microwave generator designed to work with the high emittance beam of the Advanced Test Accelerator (ATA). Simulations showed that a 800-A, 120 {pi} cm-mrad beam (typical of ATA), could produce 800 MW of rf (11.4 GHz) power using two 12-cell, traveling-wave output structures. Funding contraints prevented final tuning of the modulator system and limited the experiment to 530 MW in narrow pulses. Over 400 MW were extracted from a single output structure through fundamental waveguide. Beam breakup was successfully suppressed with >800 amperes transported through the extraction section.
Date: April 25, 1995
Creator: Houck, T.L.; Westenskow, G.A.; Haimson, J. & Mecklenburg, B.
Object Type: Article
System: The UNT Digital Library
Transport of a Partially-Neutralized Ion Beam in a Heavy-Ion Fusion Reactor Chamber (open access)

Transport of a Partially-Neutralized Ion Beam in a Heavy-Ion Fusion Reactor Chamber

In a heavy-ion driven, inertial confinement fusion power plant, a space-charge dominated beam of heavy ions must be transported through a reactor chamber and focused on a 2-3 mm spot at the target. The spot size at the target is determined by the beam emittance and space charge, plus chromatic aberrations in the focusing lens system and errors in aiming the beam. The gain of the ICF capsule depends on the focal spot size. We are investigating low density, nearly-ballistic transport using an electromagnetic, r-z particle-in-cell code. Even at low density (n {approx} 5 {times} 10{sup 13} cm{sup {minus}3}), beam stripping may be important. To offset the effects of stripping and reduce the space charge, the beam is partially charge neutralized via a pre-formed plasma near the chamber entrance. Additional electrons for charge neutralization come from ionization of the background gas by the beam. Simulations have shown that stripping can greatly increase the spot size; however, partial neutralization can offset most of this increase.
Date: April 25, 1995
Creator: Callahan, D. A. & Langdon, A. B.
Object Type: Article
System: The UNT Digital Library
Texas Register, Volume 20, Number 31, Pages 3067-3110, April 25, 1995 (open access)

Texas Register, Volume 20, Number 31, Pages 3067-3110, April 25, 1995

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 25, 1995
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History