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Current directions in screening-level ecological risk assessments (open access)

Current directions in screening-level ecological risk assessments

Ecological risk assessment (ERA) is a tool used by many regulatory agencies to evaluate the impact to ecological receptors from changes in environmental conditions. Widespread use of ERAs began with the United States Environmental Protection Agency's Superfund program to assess the ecological impact from hazardous chemicals released to the environment. Many state hazardous chemical regulatory agencies have adopted the use of ERAs, and several state regulatory agencies are evaluating the use of ERAs to assess ecological impacts from releases of petroleum and gas-related products. Typical ERAs are toxicologically-based, use conservative assumptions with respect to ecological receptor exposure duration and frequency, often require complex modeling of transport and exposure and are very labor intensive. In an effort to streamline the ERA process, efforts are currently underway to develop default soil screening levels, to identify ecological screening criteria for excluding sites from formal risk assessment, and to create risk-based corrective action worksheets. This should help reduce the time spent on ERAs, at least for some sites. Work is also underway to incorporate bioavailability and spatial considerations into ERAs. By evaluating the spatial nature of contaminant releases with respect to the spatial context of the ecosystem under consideration, more realistic ERAs with respect …
Date: December 11, 2000
Creator: Carlsen, T M & Efroymson, R A
Object Type: Article
System: The UNT Digital Library
Decision Document for the Storm Water Outfalls/Industrial Wastewater Treatment Plant, Pesticide Rinse Area, Old Fire Fighting Training Pit, Illicit PCB Dump Site, and the Battery Acid Pit Fort Lewis, Washington (open access)

Decision Document for the Storm Water Outfalls/Industrial Wastewater Treatment Plant, Pesticide Rinse Area, Old Fire Fighting Training Pit, Illicit PCB Dump Site, and the Battery Acid Pit Fort Lewis, Washington

PNNL conducted independent site evaluations for four sites at Fort Lewis, Washington, to determine their suitability for closure on behalf of the installation. These sites were recommended for "No Further Action" by previous invesitgators and included the Storm Water Outfalls/Industrial Waste Water Treatment Plant (IWTP), the Pesticide Rinse Area, the Old Fire Fighting Training Pit, and the Illicit PCB Dump Site.
Date: December 11, 2000
Creator: Cantrell, Kirk J.; Liikala, Terry L.; Strenge, Dennis L. & Taira, Randal Y.
Object Type: Report
System: The UNT Digital Library
Variations on supersymmetry breaking and neutrino spectra (open access)

Variations on supersymmetry breaking and neutrino spectra

The problem of generating light neutrinos within supersymmetric models is discussed. It is shown that the hierarchy of scales induced by supersymmetry breaking can give rise to suppression factors of the correct order of magnitude to produce experimentally allowed neutrino spectra.
Date: December 11, 2000
Creator: Borzumati, F.; Hamaguchi, K.; Nomura, Y. & Yanagida, T.
Object Type: Article
System: The UNT Digital Library
User guide for modeling of electroconsolidation process with ELEKTRA and MaPS codes. (open access)

User guide for modeling of electroconsolidation process with ELEKTRA and MaPS codes.

Electroconsolidation{reg_sign} is a proprietary process for rapid, pressure-assisted densification of powder preforms. The parts to be consolidated are placed within a bed of free-flowing powder, and pressure is applied by rams that act on the powder medium. Heat for consolidation is generated internally by electrical resistive heating of the medium while it is in direct contact with the preform(s). A mathematical model has been developed to predict the temperature profiles within the Electroconsolidation die during operation. Numerical simulation is performed by coupling a three-dimensional (3-D) finite-element electromagnetic field program (ELEKTRA) and a 3-D finite-difference materials process simulator (MaPS) to incorporate the effects of pressure and electrical fields on heat transfer and temperature variation within the die during heating and cooling. The methods used in developing the model are presented. Use of the model minimizes the experiments needed to design and evaluate commercial applications of Electroconsolidation.
Date: December 11, 2000
Creator: Chang, F. C.; Domanus, H. M. & Valentin, R. A.
Object Type: Report
System: The UNT Digital Library
Plutonium Finishing Plant (PFP) Waste Composition and High Efficiency Particulate Air Filter Loading (open access)

Plutonium Finishing Plant (PFP) Waste Composition and High Efficiency Particulate Air Filter Loading

This analysis evaluates the effect of the Plutonium Finishing Plant (PFP) waste isotopic composition on Tank Farms Final Safety Analysis Report (FSAR) accidents involving high-efficiency particulate air (HEPA) filter failure in Double-Contained Receiver Tanks (DCRTs). The HEPA Filter Failure--Exposure to High Temperature or Pressure, and Steam Intrusion From Interfacing Systems accidents are considered. The analysis concludes that dose consequences based on the PFP waste isotopic composition are bounded by previous FSAR analyses. This supports USQD TF-00-0768.
Date: December 11, 2000
Creator: ZIMMERMAN, B.D.
Object Type: Report
System: The UNT Digital Library
[News Clip: Health Watch] captions transcript

[News Clip: Health Watch]

Video footage from the KXAS-TV/NBC station in Fort Worth, Texas, to accompany a news story.
Date: December 11, 2000, 10:00 p.m.
Creator: KXAS-TV (Television station : Fort Worth, Tex.)
Object Type: Video
System: The UNT Digital Library
Differences in Bulk Damage Probability Distributions Between Tripler and Z-Cuts of KDP and DKDP at 355 nm (open access)

Differences in Bulk Damage Probability Distributions Between Tripler and Z-Cuts of KDP and DKDP at 355 nm

Over the course of testing a substantial number of KDP and DKDP crystals from rapid and conventional growth processes, we have discovered that there is a consistent difference in the value of the damage resistance between z-cut and tripler, x-cut and y-cut crystals for a given test fluence. This increase in damage probability for tripler, x and y-cut crystals is consistent for both conventional and rapid growth KDP as well as DKDP. It also holds for unconditioned (S/1) and conditioned (R/l) tests and has values of 2.1 {+-} 0.6 and 1.5 {+-} 0.3 respectively. Testing has also revealed that there is no sensitivity to incident laser polarization. This is in direct contradiction to models based on simple, non-spherical absorbers. This result plus new information on the size and evolution of bulk damage density (see Runkel et al., this proceedings) has led to a reinterpretation of the growth parameter data for rapid growth NIF boules. It now appears that variations in impurity concentration throughout the boule do not affect the damage probability curve as dramatically as previously thought; although, this is still a topic of intensive investigation.
Date: December 11, 2000
Creator: Runkel, M & Burnham, A K
Object Type: Article
System: The UNT Digital Library
Results of Pulse-Scaling Experiments on Rapid-Growth DKDP Triplers Using the Optical Sciences Laser at 351 nm (open access)

Results of Pulse-Scaling Experiments on Rapid-Growth DKDP Triplers Using the Optical Sciences Laser at 351 nm

Results are reported from recently performed bulk-damage, pulse-scaling experiments on DKDP tripler samples taken from NIF-size, rapid-growth boule BD7. The tests were performed on LLNL's Optical Sciences Laser. A matrix of samples was exposed to single shots at 351 mn (3 {omega}) with average fluences from 4 to 8 J/cm{sup 2} for pulse durations of 1, 3 and 10 ns. The damage sites were scatter-mapped after testing to determine the damage evolution as a function of local beam fluence. The average bulk damage microcavity (pinpoint) density varied nearly linearly with fluence with peak values of approximately 16,000 pp/mm{sup 3} at 1 ns, 10,000 pp/mm{sup 3} at 3 ns and 400 pp/mm{sup 3} at 10 ns for fluences in the 8-10 J/cm{sup 2} range. The average size of a pinpoint was 10(+14,-9) {micro}m at 1 ns, 37 {+-} 20 {micro}m at 3 ns and {approx} 110 {micro}m at 10 ns, although all pulse durations produced pinpoints with a wide distribution of sizes. Analysis of the pinpoint density data yielded pulse-scaling behavior of t{sup 0.35}. Significant planar cracking around the pinpoint as was observed for the 10 ns case but not for the 1 and 3 ns pulses. Crack formation around pinpoints …
Date: December 11, 2000
Creator: Runkel, M; Burnham, A K; Milam, D; Sell, W; Feit, M & Rubenchik, A
Object Type: Article
System: The UNT Digital Library
Laser conditioning characterization and damage threshold prediction of hafnia/silica multilayer mirrors by photothermal microscopy (open access)

Laser conditioning characterization and damage threshold prediction of hafnia/silica multilayer mirrors by photothermal microscopy

Laser conditioning has been shown to improve the laser damage threshold of some optical coatings by greater than 2x. Debate continues within the damage community regarding laser-conditioning mechanisms, but it is clear that nodular ejection is one of the byproducts of the laser conditioning process. To better understand why laser conditioning is so effective, photothermal microscopy was used to measure absorption of coating defects before and after laser exposure. Although a modest absorption reduction was expected due to the lower electric field peaks within a pit and the absence of potentially absorbing nodular seeds, surprisingly, absorption reductions up to 150x were observed. Photothermal microscopy has also been successfully used to correlate laser-induced damage threshold and absorption of defects in hafnia/silica multilayer optical coatings. Defects with high absorption, as indicated by high photothermal signal, have low damage thresholds. Previously a linear correlation of damage threshold and defect photothermal signal was established with films designed and damage tested at 1{omega} (1053 nm) and Brewster's angle (56.4{sup o}), but characterized by photothermal microscopy at 514.5 nm and near-normal angle of incidence (10{sup o}). In this study coatings designed, characterized by photothermal microscopy, and damage tested at the same wavelength, incident angle, and polarization …
Date: December 11, 2000
Creator: Papandrew, A B; Stolz, C J; Wu, Z L; Loomis, G E & Falabella, S
Object Type: Article
System: The UNT Digital Library
IMPACT, a Coupled Tropospheric/Stratospheric Chemistry Model: Analysis and Comparison of Results to Observations (open access)

IMPACT, a Coupled Tropospheric/Stratospheric Chemistry Model: Analysis and Comparison of Results to Observations

We have conducted multi-year simulations describing the distributions of important chemical species in both the troposphere and stratosphere using the LLNL IMPACT atmospheric chemistry model. Simulations have been completed using input meteorological data from both a general circulation model (NCAR MACCM3, Middle Atmospheric Community Climate Model Version 3) and analyzed fields (NASA Data Assimilation Office, STRATF product). IMPACT includes modules describing tropospheric and stratospheric processes and emissions to determine species distributions from the surface to approximately 70 kilometers in altitude. We compare results of these simulations with both long term and short term observational data including surface measurements, vertical profiles and others. We contrast the model's ability to simulate important photochemical cycles (CO/CH4/NMHC/NOx/OH/O3, etc) using both input meteorological datasets. In addition, IMPACT simulations driven with analyzed data are compared to ground based and aircraft campaigns.
Date: December 11, 2000
Creator: Rotman, D.; Atherton, C.; Bergmann, D.; Cameron-Smith, P.; Chuang, C.; Connell, P. et al.
Object Type: Report
System: The UNT Digital Library
Fiji Islands Political Crisis: Background, Analysis, and Chronology (open access)

Fiji Islands Political Crisis: Background, Analysis, and Chronology

None
Date: December 11, 2000
Creator: Lum, Thomas
Object Type: Report
System: The UNT Digital Library
Federal Railroad Safety Program and Reauthorization Issues (open access)

Federal Railroad Safety Program and Reauthorization Issues

This report details the Federal Railroad Safety Program, and includes information such as background, statistics, and legislative issues.
Date: December 11, 2000
Creator: Rothburg, Paul F. & Williamson, John
Object Type: Report
System: The UNT Digital Library
Oral History Interview with John Rodolf, December 11, 2000 transcript

Oral History Interview with John Rodolf, December 11, 2000

The National Museum of the Pacific War presents an oral interview with John Rodolf. Rodolf grew up in Oklahoma and joined the Army Air Force in 1942. He was in photo reconnaissance, called F-5, and was a pilot of P-38 camera vision. After training, he arrived in Guadalcanal in March 1944. He flew missions out of Bougainville covering Rabaul and Kavieng. In October 1944, he moved up to Noemfor, then to Sansapor. He continued flying until November 1945. He was in the 13th Army Air Force, 17th Photo Squadron. He took photographs for invasion purposes or finding targets for the fighters and bombers. He describes accidents in the airplane. He was stranded at sea with seven others, and they landed on an island occupied by the Japanese after the second atomic bomb had been dropped. Two of the men he was with did not survive. The remaining five were given food and water and treated for their wounds by the Japanese. They were rescued by the Australians. He married his wife in Sydney in March 1945. He went back to the United States and his wife followed. He was discharged in 1947. He returned to Oklahoma to begin his career. …
Date: December 11, 2000
Creator: Rodolf, John
Object Type: Sound
System: The Portal to Texas History
Effect of Thermal Annealing and Second Harmonic Generation on Bulk Damage Performance of Rapid-Growth KDP Type I Doublers at 1064 nm (open access)

Effect of Thermal Annealing and Second Harmonic Generation on Bulk Damage Performance of Rapid-Growth KDP Type I Doublers at 1064 nm

This paper discusses the results of thermal annealing and in-situ second harmonic generation (SHG) damage tests performed on six rapid growth KDP type 1 doubler crystals at 1064 nm (1 {omega}) on the Zeus automated damage test facility. Unconditioned (S/1) and conditioned (R/1) damage probability tests were performed before and after thermal annealing, then with and without SHG on six doubler crystals from the NIF-size, rapid growth KDP boule F6. The tests revealed that unannealed, last-grown material from the boule in either prismatic or pyramidal sectors exhibited the highest damage curves. After thermal annealing at 160 C for seven days, the prismatic sector samples increased in performance ranging from 1.6 to 2.4X, while material from the pyramidal sector increased only modestly, ranging from 1.0 to 1.4X. Second harmonic generation decreased the damage fluence by an average of 20 percent for the S/1 tests and 40 percent for R/1 tests. Conversion efficiencies under test conditions were measured to be 20 to 30 percent and compared quite well to predicted behavior, as modeled by LLNL frequency conversion computer codes. The damage probabilities at the 1 {omega} NIF redline fluence (scaled to 10 ns via t{sup 0.5}) for S/1 tests for the unannealed …
Date: December 11, 2000
Creator: Runkel, M.; Maricle, S.; Torres, R.; Auerbach, J.; Floyd, R.; Hawley-Fedder, R. et al.
Object Type: Article
System: The UNT Digital Library
The Baytown Sun (Baytown, Tex.), Vol. 79, No. 15, Ed. 1 Monday, December 11, 2000 (open access)

The Baytown Sun (Baytown, Tex.), Vol. 79, No. 15, Ed. 1 Monday, December 11, 2000

Daily newspaper from Baytown, Texas that includes local, state, and national news along with advertising.
Date: December 11, 2000
Creator: Cash, Wanda Garner
Object Type: Newspaper
System: The Portal to Texas History
Altus Times (Altus, Okla.), Vol. 101, No. 234, Ed. 1 Monday, December 11, 2000 (open access)

Altus Times (Altus, Okla.), Vol. 101, No. 234, Ed. 1 Monday, December 11, 2000

Daily newspaper from Altus, Oklahoma that includes local, state, and national news along with advertising.
Date: December 11, 2000
Creator: Bush, Michael
Object Type: Newspaper
System: The Gateway to Oklahoma History
Oral History Interview with John Rodolf, December 11, 2000 (open access)

Oral History Interview with John Rodolf, December 11, 2000

The National Museum of the Pacific War presents an oral interview with John Rodolf. Rodolf grew up in Oklahoma and joined the Army Air Force in 1942. He was in photo reconnaissance, called F-5, and was a pilot of P-38 camera vision. After training, he arrived in Guadalcanal in March 1944. He flew missions out of Bougainville covering Rabaul and Kavieng. In October 1944, he moved up to Noemfor, then to Sansapor. He continued flying until November 1945. He was in the 13th Army Air Force, 17th Photo Squadron. He took photographs for invasion purposes or finding targets for the fighters and bombers. He describes accidents in the airplane. He was stranded at sea with seven others, and they landed on an island occupied by the Japanese after the second atomic bomb had been dropped. Two of the men he was with did not survive. The remaining five were given food and water and treated for their wounds by the Japanese. They were rescued by the Australians. He married his wife in Sydney in March 1945. He went back to the United States and his wife followed. He was discharged in 1947. He returned to Oklahoma to begin his career. …
Date: December 11, 2000
Creator: Rodolf, John
Object Type: Text
System: The Portal to Texas History
The Alvin Sun (Alvin, Tex.), Vol. 109, No. 100, Ed. 1 Monday, December 11, 2000 (open access)

The Alvin Sun (Alvin, Tex.), Vol. 109, No. 100, Ed. 1 Monday, December 11, 2000

Weekly newspaper from Alvin, Texas that includes local, state, and national news along with advertising.
Date: December 11, 2000
Creator: Schwind, Jim & Holton, Kathleen
Object Type: Newspaper
System: The Portal to Texas History
High Sensitivity Measurement of Implanted as in the Presence of Ge in Ge(x)Si(1-x)/Si Layered Alloys Using Trace Element Accelerator Mass Spectrometry (open access)

High Sensitivity Measurement of Implanted as in the Presence of Ge in Ge(x)Si(1-x)/Si Layered Alloys Using Trace Element Accelerator Mass Spectrometry

This article discusses high sensitivity measurement of implanted As in the presence of Ge in Ge(x)Si(1-x)/Si layered alloys using trace element accelerator mass spectrometry.
Date: December 11, 2000
Creator: Datar, Sameer A.; Wu, Liying; Guo, Baonian N.; Nigam, Mohit; Necsoiu, Daniela; Zhai, Y. J. et al.
Object Type: Article
System: The UNT Digital Library
NATURAL RESOURCES ASSESSMENT (open access)

NATURAL RESOURCES ASSESSMENT

The purpose of this report is to summarize the scientific work that was performed to evaluate and assess the occurrence and economic potential of natural resources within the geologic setting of the Yucca Mountain area. The extent of the regional areas of investigation for each commodity differs and those areas are described in more detail in the major subsections of this report. Natural resource assessments have focused on an area defined as the ''conceptual controlled area'' because of the requirements contained in the U.S. Nuclear Regulatory Commission Regulation, 10 CFR Part 60, to define long-term boundaries for potential radionuclide releases. New requirements (proposed 10 CFR Part 63 [Dyer 1999]) have obviated the need for defining such an area. However, for the purposes of this report, the area being discussed, in most cases, is the previously defined ''conceptual controlled area'', now renamed the ''natural resources site study area'' for this report (shown on Figure 1). Resource potential can be difficult to assess because it is dependent upon many factors, including economics (demand, supply, cost), the potential discovery of new uses for resources, or the potential discovery of synthetics to replace natural resource use. The evaluations summarized are based on present-day use …
Date: December 11, 2000
Creator: Fenster, D.F.
Object Type: Report
System: The UNT Digital Library
Heavy Vehicle Propulsion System Materials Program Semiannual Progress Report for April 2000 Through September 2000 (open access)

Heavy Vehicle Propulsion System Materials Program Semiannual Progress Report for April 2000 Through September 2000

The purpose of the Heavy Vehicle Propulsion System Materials Program is the development of materials: ceramics, intermetallics, metal alloys, and metal and ceramic coatings, to support the dieselization of class 1-3 trucks to realize a 35% fuel-economy improvement over current gasoline-fueled trucks and to support commercialization of fuel-flexible LE-55 low-emissions, high-efficiency diesel engines for class 7-8 trucks. The Office of Transportation Technologies, Office of Heavy Vehicle Technologies (OTT OHVT) has an active program to develop the technology for advantages LE-55 diesel engines with 55% efficiency and low emissions levels of 2.0 g/bhp-h NOx and 0.05 g/bhp-h particulates. The goal is also for the LE-55 engine to run on natural gas with efficiency approaching that of diesel fuel. The LE-55 program is being completed in FY 1997 and, after approximately 10 years of effort, has largely met the program goals of 55% efficiency and low emissions. However, the commercialization of the LE-55 technology requires more durable materials than those that have been used to demonstrate the goals. Heavy Vehicle Propulsion System Materials will, in concert with the heavy duty diesel engine companies, develop the durable materials required to commercialize the LE-55 technologies. OTT OHVT also recognizes a significant opportunity for reduction …
Date: December 11, 2000
Creator: Johnson, D. R.
Object Type: Report
System: The UNT Digital Library
PBX 9501 Outgas Analysis by SPME/GC/MS (open access)

PBX 9501 Outgas Analysis by SPME/GC/MS

The authors used equilibrium headspace gas chromatography/mass spectrometry (GC/MS) to monitor volatile and semivolate species that are expected to migrate through PBX 9501 under environmentally relevant conditions. In this work they screened 11 samples taken from deployed parts. Although a number of chemical permeates were identified, the antioxidant signature provided the most information with regard to decomposition aging. Specifically, they were able to monitor butylated hydroxytoluene (BHT) and other antioxidants, which are apparently added to either the Estane adipate or MDI precursor by the manufacturer. They found that in those parts where diphenylamine (DPA) was used as a stabilizer, BHT response was significantly lower than in those formulations stabilized with Irganox 1010 (Irganox). These results imply that DPA is less efficient as a radical scavenger than Irganox. This lower efficiency might be related to the lack of oxygen in the weapon environment, which is initially < 0.1%. With regard to DPA, it has been reported that radical scavenging activity is proportional to the oxygen pressure. At this time they are uncertain whether the low DPA efficiency is mainly attributed to the oxygen level or if there is another rate limiting step that would lead to the preferential consumption of BHT.
Date: December 11, 2000
Creator: Chambers, D.M.
Object Type: Report
System: The UNT Digital Library
Campaign Finance: Constitutional and Legal Issues of Soft Money (open access)

Campaign Finance: Constitutional and Legal Issues of Soft Money

As in the 105th Congress, many of the 106th Congress bills focus on political party soft money--subjecting contributions, expenditures, or transfers of national political parties to the limitations, prohibitions and reporting requirements of the FECA. Other bills would restrict corporate and labor union soft money. Another major reform proposal would subject certain types of advocacy communications to FECA regulation, either fully or just insofar as disclosure requirements.
Date: December 11, 2000
Creator: Whitaker, L. Paige
Object Type: Report
System: The UNT Digital Library
Environmental Protection: New Approaches (open access)

Environmental Protection: New Approaches

This report summarizes briefly a number of "new approaches," grouped under the following categories: Information: Approaches to improve the quantity and quality of information to enhance the knowledge base underlying environ- mental decisions (e.g., risk assessment, cost-benefit analysis).Public Sector Processes: Approaches to restructure governmental processes for making environmental decisions (e.g., devolution). Incentives: Approaches that emphasize incentives as opposed to regulatory or financial penalties for achieving environmental ends. Approaches that rely on markets and common law for environmental decisions to the extent possible. Approaches to inculcate environmental values in public or private managerial decisions (e.g., sustainability).
Date: December 11, 2000
Creator: Blodgett, John E.
Object Type: Report
System: The UNT Digital Library