Prescription Drugs: Price Trends for Frequently Used Brand and Generic Drugs from 2000 through 2004 (open access)

Prescription Drugs: Price Trends for Frequently Used Brand and Generic Drugs from 2000 through 2004

A letter report issued by the Government Accountability Office with an abstract that begins "Prescription drug spending has been the fastest growing segment of national health expenditures. As the federal government assumes greater financial responsibility for prescription drug expenditures with the introduction of Medicare part D, federal policymakers are increasingly concerned about prescription drug prices. GAO was asked to examine the change in retail prices and other pricing benchmarks for drugs frequently used by Medicare beneficiaries and other individuals with health insurance from 2000 through 2004. To examine the change in retail prices from 2000 through 2004, we obtained usual and customary (U&C) prices from two state pharmacy assistance programs for drugs frequently used by Medicare beneficiaries and non-Medicare enrollees in the 2003 Blue Cross and Blue Shield (BCBS) Federal Employee Program (FEP). The U&C price is the price an individual without prescription drug coverage would pay at a retail pharmacy. Additionally, we compared the change in U&C prices for brand drugs from 2000 through 2004 to the change in two pricing benchmarks: average manufacturer price (AMP), which is the average of prices paid to manufacturers by wholesalers for drugs distributed to the retail pharmacy class of trade, and average …
Date: August 15, 2005
Creator: United States. Government Accountability Office.
System: The UNT Digital Library
Data Mining: Agencies Have Taken Key Steps to Protect Privacy in Selected Efforts, but Significant Compliance Issues Remain (open access)

Data Mining: Agencies Have Taken Key Steps to Protect Privacy in Selected Efforts, but Significant Compliance Issues Remain

A letter report issued by the Government Accountability Office with an abstract that begins "Data mining--a technique for extracting knowledge from large volumes of data--is being used increasingly by the government and by the private sector. Many federal data mining efforts involve the use of personal information, which can originate from government sources as well as private sector organizations. The federal government's increased use of data mining since the terrorist attacks of September 11, 2001, has raised public and congressional concerns. As a result, GAO was asked to describe the characteristics of five federal data mining efforts and to determine whether agencies are providing adequate privacy and security protection for the information systems used in the efforts and for individuals potentially affected by these data mining efforts."
Date: August 15, 2005
Creator: United States. Government Accountability Office.
System: The UNT Digital Library
Risk Retention Groups: Common Regulatory Standards and Greater Member Protections Are Needed (open access)

Risk Retention Groups: Common Regulatory Standards and Greater Member Protections Are Needed

A letter report issued by the Government Accountability Office with an abstract that begins "Congress authorized the creation of risk retention groups (RRG) to increase the availability and affordability of commercial liability insurance. An RRG is a group of similar businesses that creates its own insurance company to self-insure its risks. Through the Liability Risk Retention Act (LRRA), Congress partly preempted state insurance law to create a single-state regulatory framework for RRGs, although RRGs are multistate insurers. Recent shortages of affordable liability insurance have increased RRG formations, but recent failures of several large RRGs also raised questions about the adequacy of RRG regulation. This report (1) examines the effect of RRGs on insurance availability and affordability; (2) assesses whether LRRA's preemption has resulted in significant regulatory problems; and (3) evaluates the sufficiency of LRRA's ownership, control, and governance provisions in protecting the best interests of the RRG insureds."
Date: August 15, 2005
Creator: United States. Government Accountability Office.
System: The UNT Digital Library
Federal Employees Health Benefits Program: Competition and Other Factors Linked to Wide Variation in Health Care Prices (open access)

Federal Employees Health Benefits Program: Competition and Other Factors Linked to Wide Variation in Health Care Prices

A letter report issued by the Government Accountability Office with an abstract that begins "Congress is concerned about the health care spending burden facing the Federal Employees Health Benefits Program (FEHBP), the largest private health insurance program in the country. Health care spending per person varies geographically, and the underlying causes for the spending variation have not been fully explored. Understanding market forces and other factors that may influence health care spending may contribute to efforts to moderate health care spending. Health care spending varies across the country due to differences in its components, the utilization and price of health care services. A wide body of research describes extensive geographic variation in utilization. However, less is known about private sector geographic variation in prices. This report examined prices and spending in FEHBP Preferred Provider Organizations (PPOs) to determine (1) the extent to which hospital and physician prices varied geographically, (2) which factors were associated with geographic variation in hospital and physician prices, and (3) the extent to which hospital and physician price variation contributed to geographic variation in spending. We analyzed claims data from several large national PPOs participating in FEHBP. We used 2001 data, the most current data available …
Date: August 15, 2005
Creator: United States. Government Accountability Office.
System: The UNT Digital Library
CH-TRU Waste Content Codes (CH-TRUCON) (open access)

CH-TRU Waste Content Codes (CH-TRUCON)

The CH-TRU Waste Content Codes (CH-TRUCON) document describes the inventory of the U.S. Department of Energy (DOE) CH-TRU waste within the transportation parameters specified by the Contact-Handled Transuranic Waste Authorized Methods for Payload Control (CH-TRAMPAC). The CH-TRAMPAC defines the allowable payload for the Transuranic Package Transporter-II (TRUPACT-II) and HalfPACT packagings. This document is a catalog of TRUPACT-II and HalfPACT authorized contents and a description of the methods utilized to demonstrate compliance with the CH-TRAMPAC. A summary of currently approved content codes by site is presented in Table 1. The CH-TRAMPAC describes "shipping categories" that are assigned to each payload container. Multiple shipping categories may be assigned to a single content code. A summary of approved content codes and corresponding shipping categories is provided in Table 2, which consists of Tables 2A, 2B, and 2C. Table 2A provides a summary of approved content codes and corresponding shipping categories for the "General Case," which reflects the assumption of a 60-day shipping period as described in the CH-TRAMPAC and Appendix 3.4 of the CH-TRU Payload Appendices. For shipments to be completed within an approximately 1,000-mile radius, a shorter shipping period of 20 days is applicable as described in the CH-TRAMPAC and Appendix 3.5 …
Date: August 15, 2005
Creator: Westinghouse TRU Solutions LLC
System: The UNT Digital Library
Social Security Disability Insurance: The FiveMonth Waiting Period for SSDI Benefits (open access)

Social Security Disability Insurance: The FiveMonth Waiting Period for SSDI Benefits

None
Date: August 15, 2005
Creator: unknown
System: The UNT Digital Library
Single-Pass Flow Through (SPFT) Testing of Fluidized-Bed Steam Reforming (FBSR) Waste Forms (open access)

Single-Pass Flow Through (SPFT) Testing of Fluidized-Bed Steam Reforming (FBSR) Waste Forms

Two samples of fluidized-bed steam reforming (FBSR) mineral waste form product were subjected to single-pass flow-through (SPFT) testing. Sample LAW 1123 resulted from pilot-scale FBSR processing with a Hanford Envelope A low-activity waste (LAW) simulant. Sample SBW 1173 resulted from pilot-scale FBSR processing with an Idaho National Laboratory (INL) simulant commonly referred to as sodium-bearing waste (SBW). The pilot-scale waste forms were made at the Science and Technology Applications Research (STAR) facility in Idaho Falls, Idaho. The durability of the two FBSR waste forms was assessed via the SPFT test in this study. Both samples were multiphase mineral waste forms, so the SPFT test results provide an overall release rate from the multiple mineral species in each sample and are dependent on the amount of each phase present and the mineralogy of the phases present. SPFT testing was performed at temperatures of 25, 40, 70, and 90 C on LAW 1123, while SBW 1173 was only tested at 70 and 90 C. The 70 and 90 C data were compared to each other and the LAW-1123 results were compared to previous testing performed by the Pacific Northwest National Laboratory (PNNL) on a LAW Envelope C (high organic content) waste simulant. …
Date: August 15, 2005
Creator: Lorier, T. H.; Pareizs, J. M. & Jantzen, Carol M.
System: The UNT Digital Library
Discovery of New NOx Reduction Catalysts for CIDI Engines Using Combinatorial Techniques (open access)

Discovery of New NOx Reduction Catalysts for CIDI Engines Using Combinatorial Techniques

This project for the discovery of new lean reduction NOx catalysts was initiated on August 16th, 2002 and is now into its fourth year. Several materials have already been identified as NOx reduction catalysts for possible future application. NOx reduction catalysts are a critical need in the North American vehicle market since these catalysts are needed to enable both diesels and lean gasoline engines to meet the 2007-2010 emission standards. Hydrocarbon selective catalytic reduction (SCR) is a preferred technology since it requires no infrastructure changes (as may be expected for urea SCR) and most likely has the simplest engine control strategy of the three proposed NOx reduction approaches. The use of fast throughput techniques and informatics greatly enhances the possibility of discovering new NOx reduction catalysts. Using fast throughput techniques this project has already screened over 3000 new materials and evaluates hundreds of new materials a month. Evaluating such a high number of new materials puts this approach into a very different paradigm than previous discovery approaches for new NOx reduction catalysts. With so much data on materials it is necessary to use statistical techniques to identify the potential catalysts and these statistical techniques are needed to optimize compositions of …
Date: August 15, 2005
Creator: Blint, Richard J
System: The UNT Digital Library
Use of Quantitative Uncertainty Analysis to Support M&VDecisions in Super ESPCs (open access)

Use of Quantitative Uncertainty Analysis to Support M&VDecisions in Super ESPCs

None
Date: August 15, 2005
Creator: Kumar, Satish & Mathew, Paul
System: The UNT Digital Library
Investigation of Sludge Batch 3 (Macrobatch 4) Glass Sample Anomalous Behavior (open access)

Investigation of Sludge Batch 3 (Macrobatch 4) Glass Sample Anomalous Behavior

Two Defense Waste Processing Facility (DWPF) glass samples from Sludge Batch 3 (SB3) (Macrobatch 4) were received by the Savannah River National Laboratory (SRNL) on February 23, 2005. One sample, S02244, was designated for the Product Consistency Test (PCT) and elemental and radionuclide analyses. The second sample, S02247, was designated for archival storage. The samples were pulled from the melter pour stream during the feeding of Melter Feed Tank (MFT) Batch 308 and therefore roughly correspond to feed from Slurry Mix Evaporator (SME) Batches 306-308. During the course of preparing sample S02244 for PCT and other analyses two observations were made which were characterized as ''unusual'' or anomalous behavior relative to historical observations of glasses prepared for the PCT. These observations ultimately led to a series of scoping tests in order to determine more about the nature of the behavior and possible mechanisms. The first observation was the behavior of the ground glass fraction (-100 +200 mesh) for PCT analysis when contacted with deionized water during the washing phase of the PCT procedure. The behavior was analogous to that of an organic compound in the presence of water: clumping, floating on the water surface, and crawling up the beaker walls. …
Date: August 15, 2005
Creator: Bannochie, C. J.; Bibler, N. E. & Peeler, D. K.
System: The UNT Digital Library
Cost Avoidance vs. Utility Bill Accounting - Explaining theDiscrepancy Between Guaranteed Savings in ESPC Projects and UtilityBills (open access)

Cost Avoidance vs. Utility Bill Accounting - Explaining theDiscrepancy Between Guaranteed Savings in ESPC Projects and UtilityBills

Federal agencies often ask if Energy Savings PerformanceContracts (ESPCs) result in the energy and cost savings projected duringthe project development phase. After investing in ESPCs, federal agenciesexpect a reduction in the total energy use and energy cost at the agencylevel. Such questions about the program are common when implementing anESPC project. But is this a fair or accurate perception? Moreimportantly, should the federal agencies evaluate the success or failureof ESPCs by comparing the utility costs before and after projectimplementation?In fact, ESPC contracts employ measurement andverification (M&V) protocols to measure and ensure kilowatt-hour orBTU savings at the project level. In most cases, the translation toenergy cost savings is not based on actual utility rate structure, but acontracted utility rate that takes the existing utility rate at the timethe contract is signed with a clause to escalate the utility rate by afixed percentage for the duration of the contract. Reporting mechanisms,which advertise these savings in dollars, may imply an impact to budgetsat a much higher level depending on actual utility rate structure. FEMPhas prepared the following analysis to explain why the utility billreduction may not materialize, demonstrate its larger implication onagency s energy reduction goals, and advocate setting the rightexpectations at the …
Date: August 15, 2005
Creator: Kumar, S. & Sartor, D.
System: The UNT Digital Library
Task Technical and Quality Assurance Plan for the Characterization of Tank 25F Saltcake Core Samples (open access)

Task Technical and Quality Assurance Plan for the Characterization of Tank 25F Saltcake Core Samples

The Department of Energy (DOE) recognizes the need for the characterization of High-Level Waste (HLW) saltcake in the Savannah River Site (SRS) F- and H-area tank farms to support upcoming salt processing activities. As part of the enhanced characterization efforts, Tank 25F will be sampled and the samples analyzed at the Savannah River National Laboratory (SRNL). This Task Technical and Quality Assurance Plan documents the planned activities for the physical, chemical, and radiological analysis of the Tank 25F saltcake core samples. This plan does not cover other characterization activities that do not involve core sample analysis and it does not address issues regarding sampling or sample transportation. The objectives of this report are: (1) Provide information useful in projecting the composition of dissolved salt batches by quantifying important components (such as actinides, {sup 137}Cs, and {sup 90}Sr) on a per batch basis. This will assist in process selection for the treatment of salt batches and provide data for the validation of dissolution modeling. (2) Determine the properties of the heel resulting from dissolution of the bulk saltcake. Also note tendencies toward post-mixing precipitation. (3) Provide a basis for determining the number of samples needed for the characterization of future saltcake …
Date: August 15, 2005
Creator: Martino, C
System: The UNT Digital Library
Derivation and Implementation of Hybrid Fluid/Kinetic Model for Fusion Plasmas (open access)

Derivation and Implementation of Hybrid Fluid/Kinetic Model for Fusion Plasmas

This is a final report for Dr. Eric Held’s Junior Faculty in Plasmas Physics grant entitled, “Derivation and Implementation of Hybrid Fluid/Kinetic Model for Fusion Plasmas”. Progress over the three years and six months of this project included work on analytical and numerical fronts.
Date: August 15, 2005
Creator: Held, E. D.
System: The UNT Digital Library
Development of Scientific Simulation 3D Full Wave ICRF Code for Stellarators and Heating/CD Scenarios Development (open access)

Development of Scientific Simulation 3D Full Wave ICRF Code for Stellarators and Heating/CD Scenarios Development

In this report we describe theory and 3D full wave code description for the wave excitation, propagation and absorption in 3-dimensional (3D) stellarator equilibrium high beta plasma in ion cyclotron frequency range (ICRF). This theory forms a basis for a 3D code creation, urgently needed for the ICRF heating scenarios development for the operated LHD, constructed W7-X, NCSX and projected CSX3 stellarators, as well for re evaluation of ICRF scenarios in operated tokamaks and in the ITER . The theory solves the 3D Maxwell-Vlasov antenna-plasma-conducting shell boundary value problem in the non-orthogonal flux coordinates ({Psi}, {theta}, {var_phi}), {Psi} being magnetic flux function, {theta} and {var_phi} being the poloidal and toroidal angles, respectively. All basic physics, like wave refraction, reflection and diffraction are self consistently included, along with the fundamental ion and ion minority cyclotron resonances, two ion hybrid resonance, electron Landau and TTMP absorption. Antenna reactive impedance and loading resistance are also calculated and urgently needed for an antenna -generator matching. This is accomplished in a real confining magnetic field being varying in a plasma major radius direction, in toroidal and poloidal directions, through making use of the hot dense plasma wave induced currents with account to the finite Larmor …
Date: August 15, 2005
Creator: V.L., Vdovin
System: The UNT Digital Library
Development of Microorganisms with Improved Transport and Biosurfactant Activity for Enhanced Oil Recovery: Final Report (open access)

Development of Microorganisms with Improved Transport and Biosurfactant Activity for Enhanced Oil Recovery: Final Report

The project had three objectives: (1) to develop microbial strains with improved biosurfactant properties that use cost-effective nutrients, (2) to obtain biosurfactant strains with improved transport properties through sandstones, and (3) to determine the empirical relationship between surfactant concentration and interfacial tension and whether in situ reactions kinetics and biosurfactant concentration meets appropriate engineering design criteria. Here, we show that a lipopeptide biosurfactant produced by Bacillus mojavensis strain JF-2 mobilized substantial amounts of residual hydrocarbon from sand-packed columns and Berea sandstone cores when a viscosifying agent and a low molecular weight alcohol were present. The amount of residual hydrocarbon mobilized depended on the biosurfactant concentration. Tertiary oil recovery experiments showed that 10 to 40 mg/l of JF-2 biosurfactant in the presence of 0.1 mM 2,3-butanediol and 1 g/l of partially hydrolyzed polyacrylamide (PHPA) recovered 10-40% of residual oil from Berea sandstone cores. Even low biosurfactant concentrations (16 mg/l) mobilized substantial amounts of residual hydrocarbon (29%). The bio-surfactant lowered IFT by nearly 2 orders of magnitude compared to typical IFT values of 28-29 mN/m. Increasing the salinity increased the IFT with or without 2,3-butanediol present. The lowest interfacial tension observed was 0.1 mN/m. A mathematical model that relates oil recovery to …
Date: August 15, 2005
Creator: McInerney, M. J.; Duncan, K. E.; Youssef, N.; Fincher, T.; Maudgalya, S. K.; Folmsbee, M. J. et al.
System: The UNT Digital Library
Final Report: Experimental Astrophysics on the Omega Laser (open access)

Final Report: Experimental Astrophysics on the Omega Laser

This report summarized results obtained in work supported by this research grant. In hydrodynamic instability experiments related to supernovae, we showed that initial conditions have a controlling effect on material interpenetration, and demonstrated new diagnostic techniques that will provide improved data. In radiative shock experiments, we demonstrated the ability to produce and detect radiative shocks that have collapsed spatially in consequence of radiative cooling.
Date: August 15, 2005
Creator: Drake, R. Paul
System: The UNT Digital Library
Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site (open access)

Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site

This study has shown that, based upon measurements from industry standard radiation detection instruments, such as the RS model RSS-131 PICs in a controlled configuration, a person may be exposed to gamma radiation above background when in close proximity to some LLW trucks. However, in approximately half (47.7 percent) the population of trucks measured in this study, a person would receive no exposure above background at a distance of 1.0 m (3.3 ft) away from a LLW truck. An additional 206 trucks had net exposures greater than zero, but equal to or less than 1 {micro}R/h. Finally, nearly 80 percent of the population of trucks (802 of 1,012) had net exposures less than or equal to 10 {micro}R/h. Although there are no shipping or exposure standards at 1.0 m (3.3 ft) distance, one relevant point of comparison is the DOT shipping standard of 10 mrem/h at 2.0 m (6.6 ft) distance. Assuming a one-to-one correspondence between Roentgens and Rems, then 903 trucks (89.2 percent of the trucks measured) were no greater than one percent of the DOT standard at 1.0 m (3.3 ft). Had the distance at which the trucks been measured increased to 2.0 m (6.6 ft), the net …
Date: August 15, 2005
Creator: Miller, J.; Shafer, D.; Gray, K.; Church, B.; S.Campbell & Holz, B.
System: The UNT Digital Library
Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas (open access)

Field Demonstration of a Membrane Process to Separate Nitrogen from Natural Gas

None
Date: August 15, 2005
Creator: Lokhandwala, Kaaeid
System: The UNT Digital Library
Genetic Analysis of Chloroplast Translation (open access)

Genetic Analysis of Chloroplast Translation

The assembly of the photosynthetic apparatus requires the concerted action of hundreds of genes distributed between the two physically separate genomes in the nucleus and chloroplast. Nuclear genes coordinate this process by controlling the expression of chloroplast genes in response to developmental and environmental cues. However, few regulatory factors have been identified. We used mutant phenotypes to identify nuclear genes in maize that modulate chloroplast translation, a key control point in chloroplast gene expression. This project focused on the nuclear gene crp1, required for the translation of two chloroplast mRNAs. CRP1 is related to fungal proteins involved in the translation of mitochondrial mRNAs, and is the founding member of a large gene family in plants, with {approx}450 members. Members of the CRP1 family are defined by a repeated 35 amino acid motif called a ''PPR'' motif. The PPR motif is closely related to the TPR motif, which mediates protein-protein interactions. We and others have speculated that PPR tracts adopt a structure similar to that of TPR tracts, but with a substrate binding surface adapted to bind RNA instead of protein. To understand how CRP1 influences the translation of specific chloroplast mRNAs, we sought proteins that interact with CRP1, and identified …
Date: August 15, 2005
Creator: Barkan, Alice
System: The UNT Digital Library
Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site (open access)

Assessing Potential Exposure from Truck Transport of Low-level Radioactive Waste to the Nevada Test Site

Since 1980, over 651,558 m{sup 3} (23,000,000 ft{sup 3}) of low-level radioactive waste (LLW) have been disposed of at the Nevada Test Site (NTS) by shallow land burial. Since 1988, the majority of this waste has been generated at other United States (U.S.) Department of Energy (DOE) and Department of Defense (DoD) sites and facilities in the U.S. Between fiscal year (FY) 2002 and the publication date, the volumes of LLW being shipped by truck to the NTS increased sharply with the accelerated closure of DOE Environmental Management (EM) Program sites (DOE, 2002). The NTS is located 105 km (65 mi) northwest of Las Vegas, Nevada, in the U.S. There continue to be public concerns over the safety of LLW shipments to the NTS. They can be broadly divided into two categories: (1) the risk of accidents involving trucks traveling on public highways; and (2) whether residents along transportation routes receive cumulative exposure from individual LLW shipments that pose a long-term health risk. The DOE and U.S. Department of Transportation (DOT) regulations ensure that radiation exposure from truck shipments to members of the public is negligible. Nevertheless, particularly in rural communities along transportation routes in Utah and Nevada, there is …
Date: August 15, 2005
Creator: Miller, J; Shafer, D; Gray, K; Church, B; Campbell, S & Holtz, B.
System: The UNT Digital Library
Data Analysis of Plutonium Sorption on Colloids in a Minimal Kinetics Model (open access)

Data Analysis of Plutonium Sorption on Colloids in a Minimal Kinetics Model

We considered a sorption model containing the minimal dynamic features of the system to fit plutonium adsorption data similar to that developed by Painter et al. (2002). Global fits to recent data favored nonzero values of reversible sorption, allowing the definition of equilibrium distribution coefficients in all cases except the synthetic form of montmorillonite. In most cases, the two-site model was adequate to fit the data. The model represents a mathematic simplification of the time-dependent sorption process and takes no account for pH-dependent surface charge changes and actinide-mineral surface interfacial chemistry. However, this allows the model to be readily incorporated into existing performance assessment codes when applied to repository environment relevant data sets.
Date: August 15, 2005
Creator: Wittman, Richard S.; Buck, Edgar C. & Hanson, Brady D.
System: The UNT Digital Library
Wakefields in the LCLS Undulator Transitions (open access)

Wakefields in the LCLS Undulator Transitions

We have studied longitudinal wakefields of very short bunches in non-cylindrically symmetric (3D) vacuum chamber transitions using analytical models and the computer program ECHO. The wake (for pairs of well-separated, non-smooth transitions) invariably is resistive, with its shape proportional to the bunch distribution. For the example of an elliptical collimator in a round beam pipe we have demonstrated that--as in the cylindrically symmetric (2D) case--the wake can be obtained from the static primary field of the beam alone. We have obtained the wakes of the LCLS rectangular-to-round transitions using indirect (numerical) field integration combined with a primary beam field calculation. For the LCLS 1 nC bunch charge configuration we find that the total variation in wake-induced energy change is small (0.03% in the core of the beam, 0.15% in the horns of the distribution) compared to that due to the resistive wall wakes of the undulator beam pipe (0.6%).
Date: August 15, 2005
Creator: Bane, Karl L. F. & Zagorodnov, Igor A.
System: The UNT Digital Library
First Order QED Corrections to the Parity-Violating Asymmetry in Moller Scattering (open access)

First Order QED Corrections to the Parity-Violating Asymmetry in Moller Scattering

We compute a full set of the first order QED corrections to the parity-violating observables in polarized Moeller scattering. We employ a covariant method of removing infrared divergences, computing corrections without introducing any unphysical parameters. When applied to the kinematics of the SLAC E158 experiment, the QED corrections reduce the parity violating asymmetry by 4.5%. We combine our results with the previous calculations of the first-order electroweak corrections and obtain the complete {Omicron}({alpha}) prescription for relating the experimental asymmetry A{sub LR} to the low-energy value of the weak mixing angle sin{sup 2} {theta}{sub W}. Our results are applicable to the recent measurement of A{sub LR} by the SLAC E158 collaboration, as well as to the future parity violation experiments.
Date: August 15, 2005
Creator: Zykunov, Vladimir A.; U., /Gomel State Tech.; Suarez, Juan; /Minsk, High Energy Phys. Ctr.; Tweedie, Brock A.; Kolomensky, Yury G. et al.
System: The UNT Digital Library
Nepheline Formation Potential in Sludge Batch 4 (SB4) and Its Impact on Durability: Selecting Glasses for a Phase 2 Study (open access)

Nepheline Formation Potential in Sludge Batch 4 (SB4) and Its Impact on Durability: Selecting Glasses for a Phase 2 Study

The likelihood for the formation of nepheline in Sludge Batch 4 (SB4) glass systems and the potential impact of nepheline on the durability of these systems is part of the frit development efforts for SB4. The effect of crystallization on glass durability is complex and depends on several interrelated factors including the change in residual glass composition, the formation of internal stress or microcracks, and the preferential attack at the glass-crystal interface. Perhaps one of the most significant effects is the type and extent (or fraction) of crystallization and the change to the residual glass composition. A strong increase in glass dissolution (or decrease in durability) has been observed in previous studies in glasses that formed aluminum-containing crystals, such as NaAlSiO{sub 4} (nepheline) and LiAlSi{sub 2}O{sub 6}, and crystalline SiO{sub 2}. Although it is well known that the addition of Al{sub 2}O{sub 3} to borosilicate glasses enhances the durability of the waste form (through creation of network-forming tetrahedral Na{sup +}-[AlO{sub 4/2}]{sup -} pairs), the combination of high Al{sub 2}O{sub 3} and Na{sub 2}O can lead to the formation of nepheline (NaAlSiO{sub 4}). Given the projected high concentration of Al{sub 2}O{sub 3} in SB4 and the potential use of a high …
Date: August 15, 2005
Creator: Peeler, D
System: The UNT Digital Library