Effects of MgO on the Short- and Long-Term Stability of R7T7 and M7 Nuclear Waste Glass in Aqueous Media

1992 ◽  
Vol 294 ◽  
Author(s):  
T. Advocat ◽  
J.L. Crovisier ◽  
J.L. Dussossoy ◽  
E. Vernaz
Keyword(s):  
Alkali Metals ◽  
Glass Composition ◽  
Pure Water ◽  
Aqueous Media ◽  
Aqueous Corrosion ◽  
Long Term Stability ◽  
Nuclear Waste Glass ◽  
Experimental Protocols ◽  
Short And Long Term

ABSTRACTExperiments were conducted in initially pure water at 90°C and 100°C with glass specimens enriched in MgO and in alkali metals relative to the standard light water R7T7 reference glass. Three experimental protocols were implemented: Soxhlet testing with leachant renewal, static leaching according to a modified MCC-1 method with an SA/V ratio of 50 m−1, and static leaching with glass powder for an SA/V ratio of 8000 m−1 The results clearly show that the short and, especially, the long term dissolution rates depend on the initial glass composition. Higher MgO, Na2O, Li2O and B2O3 concentrations reduce the glass resistance to aqueous corrosion, as already indicated by the calculated hydration energy values. These experiments illustrate the importance of the glass composition in insuring long-term material integrity.

scholarly journals Short-Term Exuberance and Long-Term Stability: A Simultaneous Optimization of Stock Return Predictions for Short and Long Horizons

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 620
Author(s):  
Ioannis Kyriakou ◽  
Parastoo Mousavi ◽  
Jens Perch Nielsen ◽  
Michael Scholz
Keyword(s):  
Stock Returns ◽  
Simultaneous Optimization ◽  
Investment Risk ◽  
Short Term ◽  
Fundamental Interest ◽  
Long Term Stability ◽  
Risk Appetite ◽  
Short And Long Term ◽  
Excess Stock Returns

The fundamental interest of investors in econometric modeling for excess stock returns usually focuses either on short- or long-term predictions to individually reduce the investment risk. In this paper, we present a new and simple model that contemporaneously accounts for short- and long-term predictions. By combining the different horizons, we exploit the lower long-term variance to further reduce the short-term variance, which is susceptible to speculative exuberance. As a consequence, the long-term pension-saver avoids an over-conservative portfolio with implied potential upside reductions given their optimal risk appetite. Different combinations of short and long horizons as well as definitions of excess returns, for example, concerning the traditional short-term interest rate but also the inflation, are easily accommodated in our model.

Short- and long-term stability of the JILAG-4 Absolute Gravimeter

1993 ◽  
Vol 98 (B3) ◽  
pp. 4619-4626 ◽  
Author(s):  
George Peter ◽  
Fred J. Klopping ◽  
Glenn S. Sasagawa ◽  
James E. Faller ◽  
Timothy M. Niebauer
Keyword(s):  
Absolute Gravimeter ◽  
Term Stability ◽  
Long Term Stability ◽  
Short And Long Term

scholarly journals Development of a Water Matrix Certified Reference Material for Volatile Organic Compounds Analysis in Water

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4370
Author(s):  
Liping Fang ◽  
Linyan Huang ◽  
Gang Yang ◽  
Yang Jiang ◽  
Haiping Liu ◽  
...  
Keyword(s):  
Volatile Organic Compounds ◽  
Reference Material ◽  
Organic Compounds ◽  
Certified Reference Material ◽  
Pure Water ◽  
Term Stability ◽  
Long Term Stability ◽  
Water Matrix ◽  
Volatile Organic

Water matrix certified reference material (MCRM) of volatile organic compounds (VOCs) is used to provide quality assurance and quality control (QA/QC) during the analysis of VOCs in water. In this research, a water MCRM of 28 VOCs was developed using a “reconstitution” approach by adding VOCs spiking, methanol solution into pure water immediately prior to analysis. The VOCs spiking solution was prepared gravimetrically by dividing 28 VOCs into seven groups, then based on ISO Guide 35, using gas chromatography-mass spectrometry (GC-MS) to investigate the homogeneity and long-term stability. The studies of homogeneity and long-term stability indicated that the batch of VOCs spiking solution was homogeneous and stable at room temperature for at least 15 months. Moreover, the water MCRM of 28 VOCs was certified by a network of nine competent laboratories, and the certified values and expanded uncertainties of 28 VOCs ranged from 6.2 to 17 μg/L and 0.5 to 5.3 μg/L, respectively.

scholarly journals Black phosphorus with near-superhydrophobic properties and long-term stability in aqueous media

2018 ◽  
Vol 54 (31) ◽  
pp. 3831-3834 ◽  
Author(s):  
Peter D. Matthews ◽  
Wisit Hirunpinyopas ◽  
Edward A. Lewis ◽  
Jack R. Brent ◽  
Paul D. McNaughter ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Black Phosphorus ◽  
Term Stability ◽  
Long Term Stability ◽  
Polymeric Stabilizer

We present the use of a polymeric stabilizer which stymies the degradation of black phosphorus nanosheets in aqueous media as well as imparting superhydrophobic properties to immobilised nanosheets.

Sintered Glasses for High-Level Wastes

1996 ◽  
Vol 465 ◽  
Author(s):  
D. O. Russo ◽  
N. B. Messi de Bernasconi ◽  
M. E. Sterba ◽  
A. D. Heredia ◽  
M. Sanfilippo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aqueous Media ◽  
Underground Water ◽  
Aqueous Corrosion ◽  
Γ Radiation ◽  
Sintered Glass ◽  
A Value ◽  
Aqueous Corrosion Resistance ◽  
High Level

ABSTRACTThe objective of the work was to evaluate the long-term capacity of sintered glass to retain high-level nuclear wastes (HLW) in near-repository conditions. We have studied the corrosion behavior of waste forms partially devitrified (43 vol.%) in different aqueous media. Devitrified samples were irradiated at doses (γ radiation from a Co 60 source) ranging from 1.4 × 106 Gy to 2.0 × 108 Gy, in order to study their aqueous corrosion resistance in simulated underground water. The results show little or no effect of irradiation on the density, microstructure and corrosion resistance. The global dissolution rate was almost constant around a value of 5×10−5 g. cm−2 d−1. Elemental dissolution rates were also unaffected by radiation.

scholarly journals Les interprètes japonais en Algérie

2002 ◽  
Vol 33 (1) ◽  
pp. 90-93
Author(s):  
Michihiro Nohara
Keyword(s):  
North Africa ◽  
North African ◽  
African Countries ◽  
Heavy Industry ◽  
Long Term Stability ◽  
The Sixties ◽  
Short And Long Term ◽  
Japanese Companies ◽  
North African Countries

Summary Since the end of the sixties, numerous Japanese contractors have been active in heavy industry work in Algeria and other North African countries. This has opened a large market for Japanese-French liaison interpreters. Such interpreters are hired by specialized agencies in Europe and Japan. With one or two exceptions, they are Japanese nationals. Most of them are young and have no previous experience as interpreters. Neither are they properly briefed before they are sent to the site, but they become proficient in their work with experience. Their tasks range from interpreting at various levels to translation and even participation in negotiations and report drafting. Material working conditions are comparatively good, but the duration of contracts is short and long-term stability of employment is uncertain. The precariousness of interpreting jobs and the temporary nature of the Japanese companies' contracting work in North Africa make this activity a provisional and highly volatile one. Japanese liaison interpreters in North Africa do not feel like professional interpreters and do not aspire to become professionals.

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