Nd- and Ce-doped ceramic-glass composites: chemical durability under aqueous conditions and Surface alteration in a moist clay medium at 90°C

2000 ◽  
Vol 663 ◽  
Author(s):  
P.J. Mcglinn ◽  
T. Advocat ◽  
E. Loi ◽  
G. Leturcq ◽  
J.P. Mestre
Keyword(s):  
Chemical Durability ◽  
Powdered Sample ◽  
Leaching Behavior ◽  
Glass Composites ◽  
Geological Repository ◽  
Trivalent Actinides ◽  
Surface Alteration ◽  
Ceramic Glass ◽  
Aqueous Conditions

ABSTRACTZirconolite-glass and sphene -glass specimens, doped with REE as simulants for trivalent actinides, were leached under two conditions. The first was a solubility test using a powdered sample in deionized water at an SA/V ratio of 200 cm−1, to examine the long-term leaching behavior of the composite materials. The other test was carried out in the presence of moist clay, to assess the degree of surface alteration of the composites in the presence of potential geological repository materials. Both tests were carried out at 90°C.

scholarly journals An Evaluation of the Long-term Leaching Behavior of Heavy Metals from Granulated Incineration Ash

2020 ◽  
Vol 15 (3) ◽  
pp. 471-478
Author(s):  
Satoshi SHINOHARA ◽  
Tatsushi KAWAI ◽  
Daisuke ISHIGAMI ◽  
Junichi KAWABATA ◽  
Takeshi SATO ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Leaching Behavior

EXPERIMENTAL INVESTIGATION OF THE DURABILITY OF LOAD BEARING TIMBER-GLASS COMPOSITES UNDER THE EFFECTS OF ACCELERATED AGING

2019 ◽  
Vol 14 (2) ◽  
pp. 45-59 ◽  
Author(s):  
Halet Almila Arda Buyuktaskin ◽  
Mehmet Serkan Yatagan ◽  
Gulseren Erol Soyoz ◽  
Leyla Tanacan ◽  
Morvarid Dilmaghani
Keyword(s):  
Raw Materials ◽  
Accelerated Aging ◽  
Structural Elements ◽  
Atmospheric Conditions ◽  
Aging Effects ◽  
Glass Composite ◽  
Load Bearing ◽  
Glass Composites ◽  
Before And After

Although timber was used extensively as a structural material for traditional buildings in Turkey in the past, usage of structural timber decreased significantly over time and timber has been largely replaced by other materials. As timber is a natural, durable and sustainable material, it would be desirable to re-introduce timber structural elements to contemporary construction in a form that is appealing to industry. Timber-glass composite structural elements are potentially a good candidate for this purpose. To that end, a series of tests were conducted on load-bearing timber-glass composites in order to understand the long–term structural performance of the composite material under atmospheric conditions; to decrease the recurring cost of repair and maintenance; and to minimize the exhaustion of raw materials and energy. In this paper, the first part of this experimental work is presented, which focuses on the durability of timber-glass composite under the effects of accelerated aging, carried out on small-sized timber-glass composite specimens. Accelerated aging effects were observed under wetting-drying, freezing-thawing, UV effects, resistance to acids and high temperature. The mechanical strength of the timber-glass composite specimens before and after the effect of accelerated aging was measured by adhesion and shear strength tests and a comparative analysis of the results was carried out. The results of the experiments indicate that timber-glass composite is suitable to be used under protection from environmental conditions.

scholarly journals Assessment of the climate changes evolution for the long-term safety of the radioactive waste repository in the Czech Republic

2019 ◽  
Vol 133 ◽  
pp. 02005
Author(s):  
Markéta Camfrlová
Keyword(s):  
Czech Republic ◽  
Radioactive Waste ◽  
Spent Nuclear Fuel ◽  
Global Climate ◽  
Deep Geological Repository ◽  
Climatic Effects ◽  
The Czech Republic ◽  
Area Of Interest ◽  
Geological Repository

Nuclear energy accounts for a significant part of the total energy production in the Czech Republic, which is currently facing a problem dealing with the high-level radioactive waste (HLW) and the spent nuclear fuel (SNF). Deep repository is the safest option for storage of HLW. Rock environment of the area must guarantee the stability of the deep geological repository for at least 100,000 years. The aim of the research is a long-term evaluation of the climatic changes of the hypothetical area of interest, which corresponds to the candidate sites for deep geological repository in the Czech Republic. The occurrences of endogenous and exogenous phenomena, which could affect site stability, were evaluated. Concerning exogenous processes, research focuses mainly on the assessment of climatic effects. The climate scenarios for the Central Europe were examined – global climate change, glaciation, and the depth of permafrost as well as CO2 increase.

scholarly journals Assessment of the impact of selected changes in the deep geological repository model on its long-term safety

2020 ◽  
Vol 225 ◽  
pp. 06012
Author(s):  
Dorota Flamíková ◽  
Vladimír Nečas
Keyword(s):  
Effective Dose ◽  
Annual Effective Dose ◽  
Monitoring Program ◽  
Distribution Coefficients ◽  
Exposure Group ◽  
Deep Geological Repository ◽  
Adult Individual ◽  
Geological Repository ◽  
The Impact

The deep geological repository system provides long-term protection against the undesirable effects of ionizing radiation on the population and the environment. An important part of the long-term safety strategy is development of a monitoring program that collects information about the behaviour of the deep geological repository throughout its whole lifetime. A simplified model of the disposal system, geosphere, and biosphere was developed using the GoldSim simulation tool to demonstrate the behaviour of the hypothetical deep geological repository located in crystalline rocks. Also an initial model of the reference biosphere was created based on the scenario of an agricultural habitation (normal evolution scenario) and it was developed based on the recommendations provided in the BIOMASS methodology. After a significant period of time, disposal containers will be degraded and evolution changes in the repository system will occur. Several important parameters appear in the annual effective dose calculation for an individual from critical exposure group within the reference biosphere model. One of them are, for example, distribution coefficients and so-called translocation factors that define the transported rate of released radionuclides into the environment. This paper provides a view into the selected part of the deep geological repository through the data obtained by monitoring during the selected period of time. Simulations describing changes in the repository system. The aim of this contribution is to evaluate the impact of selected changes on the annual effective dose for an adult individual from a critical exposure group while it is assumed, that the respondent consumes contaminated crops and animal products. This model includes various biosphere components and multiple exposure pathways such as inhalation, ingestion and external exposure.

scholarly journals Long-Term Leaching Behavior of Marine Sediment by a Large Column Percolation Test

2020 ◽  
Vol 69 (1) ◽  
pp. 53-56
Author(s):  
Toru INUI ◽  
Mutsumi HORI ◽  
Takeshi KATSUMI ◽  
Atsushi TAKAI
Keyword(s):  
Marine Sediment ◽  
Leaching Behavior ◽  
Percolation Test

Ocular Surface Alteration after Long-term Treatment with an Antiglaucomatous Drug

Ophthalmology ◽  
1992 ◽  
Vol 99 (7) ◽  
pp. 1082-1088 ◽  
Author(s):  
José M. Herreras ◽  
J. Carlos Pastor ◽  
Margarita Calonge ◽  
Victor M. Asensio
Keyword(s):  
Ocular Surface ◽  
Term Treatment ◽  
Long Term Treatment ◽  
Surface Alteration

Prediction of the Deterioration Depth of Concrete by Accelerating Calcium Leaching Test

2011 ◽  
Vol 365 ◽  
pp. 3-7 ◽  
Author(s):  
An Cheng ◽  
Sao Jeng Chao ◽  
Wei Ting Lin ◽  
Jia Liang Chang
Keyword(s):  
Nitrate Solution ◽  
Leaching Behavior ◽  
Calcium Leaching ◽  
Ammonium Nitrate Solution ◽  
Binder Ratio ◽  
Two Stages ◽  
Strength And Durability ◽  
Calcium Ion Leaching ◽  
Water Binder Ratio

The concrete is a solid and porous composite materials, when the concrete exposure to moisture environment for a long-term, the pore water will penetrate into concrete cause hydration products leaching. Leaching of calcium ions increase in porosity and resulting in harmful ions ingress into concrete to reduce strength and durability of concrete. The purpose of this study is to evaluate the effect of water-binder ratio on calcium ion leaching behavior of cement-based material. The ammonium nitrate solution was used to accelerate leaching process. Leaching duration was 56 days, 91 days and 140 days, respectively. The leaching depth and compressive strength were measured. The results showed that leaching resistance increased with a decrease in water/binder ratio. The leaching depth showed that leaching behavior of the specimens without minerals admixtures can be divided into two stages, the first stage was leaching of calcium hydroxide and than the C-S-H gel were leaching.

Sign in / Sign up

Export Citation Format

Share Document