Glass Waste Form Performance for Disposal of the Cesium and Strontium Concentrate Resulting From the Partitioning of HLW

1997 ◽  
Vol 506 ◽  
Author(s):  
A.S. Aloy ◽  
O.A. Iskhakova ◽  
T.I. Kol‘tsova ◽  
A.V. Trofimenko
Keyword(s):  
Waste Form ◽  
Glass Waste ◽  
Mineralized Water ◽  
Strontium 90 ◽  
Before And After ◽  
Cesium 137 ◽  
Long Term Performance ◽  
Term Performance ◽  
Made In

ABSTRACTThe recent advances in HLW partitioning indicate that cesium–137 and strontium–90 can be separated in the form of a pure concentrate. Based on this concentrate the glass RT2–1 containing 4.7 wt.% Cs2O and 2.7 wt.% SrO was selected for more intensive and wider studies to predict long-term performance of this waste form under repository conditions.Leach tests were made in distilled and mineralized water before and after crystallization at 20, 90 and 130°C.Fully devitrified glass contained only one crystalline phase corresponding to the pollucite structure.

scholarly journals NNWSI Waste Form Performance Test Development

1984 ◽  
Vol 44 ◽  
Author(s):  
John K. Bates ◽  
Thomas J. Gerding
Keyword(s):  
Performance Test ◽  
Test Development ◽  
Test Method ◽  
Waste Form ◽  
Analog Test ◽  
Waste Package ◽  
Long Term Performance ◽  
Term Performance

AbstractA test method has been developed to measure the release of radionuclides from the waste package under simulated NNWSI repository conditions, and to provide information concerning materials interactions that may occur in the repository. Data from 13 weeks of unsaturated testing are discussed and compared to that from a 13 week analog test. The data indicate that the waste form test is capable of producing consistent, reproducible results that will be useful in evaluating the role of the waste package in the long-term performance of the repository.

scholarly journals The Roles of Foreign Ownership and Growth Opportunity amid the Trade War: Evidence from an Emerging Country

2021 ◽  
Author(s):  
鬼谷 子
Keyword(s):  
Foreign Ownership ◽  
Least Square ◽  
Short Term ◽  
Moderator Variable ◽  
Growth Opportunity ◽  
Before And After ◽  
Trade War ◽  
Long Term Performance ◽  
Term Performance

In recent years investors tend to divert their investment to emerging economies in the Association of Southeast Asian Nations (ASEAN), especially during the U.S.-China trade war. The present study adopts the Weighted Least Square (WLS) and PROCESS macro tool to examine the effects of foreign ownership and growth opportunity on financial performance of Vietnamese listed firms over the period 2011-2018. Our findings show that foreign ownership plays as moderator variable in the relationship between short-term and long-term performance of firms. Empirical results also reveal that mediating effects of growth opportunity on short-term and long-term performance are different before and after the trade war. These findings have important implications for investors and managers in the ASEAN countries.

Stone Consolidation by Bacterial Carbonatogenesis: Evaluation of in situ Applications

2015 ◽  
Vol 21 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Carlos Rodriguez-Navarro ◽  
Fadwa Jroundi ◽  
Maria Teresa Gonzalez-Muñoz
Keyword(s):  
Culturable Bacteria ◽  
Conservation Treatment ◽  
Color Changes ◽  
Before And After ◽  
Culture Independent ◽  
Acid Producing Bacteria ◽  
Long Term Performance ◽  
Term Performance

Abstract Precipitation of calcium carbonate minerals by bacteria, the so-called bacterial carbonatogenesis, is a promising method for the consolidation of decayed stone. Despite extensive laboratory testing that has demonstrated the efficacy of this method, little is, however, known regarding the medium- and/or long-term performance of this bacterial conservation treatment once applied in situ, on stone buildings. Here, we report on the evaluation of the performance of bacterial consolidation treatments applied in three different historical buildings placed in an urban environment and built using a highly porous, easily decayed calcarenite stone. Peeling tape tests show a significant long-lasting (up to four years) strength improvement following treatment with either a Myxococcus xanthus bacterial culture or a sterile nutritional solution that selectively activates the carbonatogenic bacteria inhabiting the stone. Total color changes, measured before and after treatment using a spectrophotometer, are systematically below the acceptable value of ΔE ≤ 5. Culture-dependent analysis of the microbiota shows that 100% of the culturable bacteria collected before and after treatment is carbonatogenic, and the total count of fungi spores remains constant or diminishes, while the population of acid-producing bacteria decreases over time after treatment application. Culture-independent microbial analyses show that no deleterious microbiota develops after treatment, being carbonate-producing Proteobacteria, Firmicutes and Actinobacteria the most abundant phyla both before and after treatment. Overall these results show that the in situ application of the bacterial consolidation method shows no detrimental side effects and is highly effective in the medium- and long-term.

HCC Risk Scores: Useful or Not?

2017 ◽  
Vol 37 (04) ◽  
pp. 287-295 ◽  
Author(s):  
Morris Sherman
Keyword(s):  
Hepatocellular Carcinoma ◽  
At Risk ◽  
Hepatitis B ◽  
External Validation ◽  
Risk Scores ◽  
Before And After ◽  
Changes In Risk ◽  
Long Term Performance ◽  
Term Performance

AbstractThe advent and efficacy of surveillance for hepatocellular carcinoma (HCC) has necessitated the refinement of assessing who is at risk for this cancer. Initially, risk was assessed for all individuals with hepatitis B and all those with cirrhosis. However, the majority of these individuals do not develop HCC so that providing surveillance for all is a waste of resources. There are now many different scores that have been developed that allow better identification of who is at risk and who is not. Specific models have been developed for hepatitis B before and on treatment, for hepatitis C before and after treatment, and for cirrhosis in general. There are also models for assessing risk in the general population. Some models can only be applied to patients coming from the population in which the score was developed (e.g., hepatitis B). Others are more generalizable. Many lack external validation. With some exceptions, the models do not attempt to assess the score at which surveillance should start. Overall, the models provide some useful guidance as to who does not need to undergo surveillance, but the long-term performance and how changes in risk score correlate with changes in HCC risk has not been completely assessed.

The Long-Term Performance of Nuclear Waste Forms: Natural Materials - Three Case Studies

1992 ◽  
Vol 294 ◽  
Author(s):  
Rodney C. Ewing
Keyword(s):  
Case Studies ◽  
Nuclear Waste ◽  
Experimental Results ◽  
Waste Form ◽  
Short Term ◽  
Waste Forms ◽  
Long Term Performance ◽  
Term Performance ◽  
Nuclear Waste Forms

ABSTRACTNatural materials may be used to advantage in the evaluation of the long-term performance of nuclear waste forms. Three case studies are presented: (I) radiation effects in ceramic waste forms; (II) corrosion products of U02 under oxic conditions; (III) corrosion rate of nuclear waste glasses. For each case, a natural phase which is structurally and chemically analogous to the waste form is identified and used to evaluate the long-term behavior of a nuclear waste form. Short-term experimental results are compared to the observations made of analogous natural phases. The three case studies illustrate that results may range between providing fundamental data needed for the long-term evaluation of a waste form to only providing qualitative data of limited use. Although in the most rigorous view the long-term behaviour of a phase cannot be predicted, the correspondence between short-term experimental results and observations made of natural phases provides confidence in the “predicted” behavior of the waste form. The strength of this approach rests with the degree to which a mechanistic understanding of the phenomenon is attained.

scholarly journals The Roles of Foreign Ownership and Growth Opportunity amid the Trade War: Evidence from an Emerging Country

2021 ◽  
Author(s):  
AISDL
Keyword(s):  
Foreign Ownership ◽  
Least Square ◽  
Short Term ◽  
Moderator Variable ◽  
Growth Opportunity ◽  
Before And After ◽  
Trade War ◽  
Long Term Performance ◽  
Term Performance

In recent years investors tend to divert their investment to emerging economies in the Association of Southeast Asian Nations (ASEAN), especially during the U.S.-China trade war. The present study adopts the Weighted Least Square (WLS) and PROCESS macro tool to examine the effects of foreign ownership and growth opportunity on financial performance of Vietnamese listed firms over the period 2011-2018. Our findings show that foreign ownership plays as moderator variable in the relationship between short-term and long-term performance of firms. Empirical results also reveal that mediating effects of growth opportunity on short-term and long-term performance are different before and after the trade war. These findings have important implications for investors and managers in the ASEAN countries.

scholarly journals Earnings Quality and Ownership Structure: The Role of Private Equity Sponsors

2009 ◽  
Vol 84 (3) ◽  
pp. 623-658 ◽  
Author(s):  
Sharon P. Katz
Keyword(s):  
Initial Public Offering ◽  
Stock Price ◽  
Private Equity ◽  
Earnings Quality ◽  
Price Performance ◽  
Before And After ◽  
Public Offering ◽  
Long Term Performance ◽  
Term Performance

ABSTRACT: This study explores how firms' ownership structures affect their earnings quality and long-term performance. Focusing on a unique sample of private firms for which there is financial data available in the years before and after their initial public offering (IPO), I differentiate between those that have private equity sponsorship (PE-backed firms) and those that do not (non-PE-backed firms). The findings indicate that PE-backed firms generally have higher earnings quality than those that do not have PE sponsorship, engage less in earnings management, and report more conservatively both before and after the IPO. Further, PE-backed firms that are majority-owned by PE sponsors exhibit superior long-term stock price performance after they go public. These results stem from the professional ownership, tighter monitoring, and reputational considerations exhibited by PE sponsors.

scholarly journals Preparation and characterization of multiphase ceramic designer waste forms

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Braeden M. Clark ◽  
Priyatham Tumurugoti ◽  
Shanmugavelayutham K. Sundaram ◽  
Jake W. Amoroso ◽  
James C. Marra
Keyword(s):  
Fixed Ratio ◽  
Chemical Durability ◽  
Waste Form ◽  
Ceramic Waste ◽  
Waste Forms ◽  
Plasma Sintering ◽  
Long Term Performance ◽  
Term Performance ◽  
Elemental Release

AbstractThe long-term performance, or resistance to elemental release, is the defining characteristic of a nuclear waste form. In the case of multiphase ceramic waste forms, correlating the long-term performance of multiphase ceramic waste forms in the environment to accelerated chemical durability testing in the laboratory is non-trivial owing to their complex microstructures. The fabrication method, which in turn affects the microstructure, is further compounding when comparing multiphase ceramic waste forms. In this work, we propose a “designer waste form” prepared via spark plasma sintering to limit interaction between phases and grain growth during consolidation, leading to monolithic high-density waste forms, which can be used as reference materials for comparing the chemical durability of multiphase waste forms. Designer waste forms containing varying amounts of hollandite in the presence of zirconolite and pyrochlore in a fixed ratio were synthesized. The product consistency test (PCT) and vapor hydration test (VHT) were used to assess the leaching behavior. Samples were unaffected by the VHT after 1500 h. As measured by the PCT, the fractional Cs release decreased as the amount of hollandite increased. Elemental release from the zirconolite and pyrochlore phases did not appear to significantly contribute to the elemental release from the hollandite phase in the designer waste forms.

Fine Particle Mass Monitoring with Low-Cost Sensors: Corrections and Long-Term Performance Evaluation

2019 ◽  
Author(s):  
Carl Malings ◽  
Rebecca Tanzer ◽  
Aliaksei Hauryliuk ◽  
Provat K. Saha ◽  
Allen L. Robinson ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Fine Particle ◽  
Low Cost ◽  
Particle Mass ◽  
Long Term Performance ◽  
Term Performance
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