Consistency of the strontium transport parameters in Boom Clay obtained from different types of migration experiments

2009 ◽  
Vol 1193 ◽  
Author(s):  
Marc Aertsens ◽  
Norbert Maesa ◽  
Marc Van Gompel
Keyword(s):  
Water Concentration ◽  
Transport Parameters ◽  
Electrical Field ◽  
Boom Clay ◽  
Linear Sorption ◽  
Different Types ◽  
Apparent Diffusion ◽  
Through Diffusion ◽  
Accessible Porosity

AbstractThe consistency of migration parameters obtained by different methods is examined for strontium in Boom Clay. In addition to a previous in-situ percolation experiment and electromigration experiments (using an electrical field as driving force), a lab percolation test and two through-diffusion tests (on clay cores of different lengths) have been performed.All experiments lead to a robust value for the apparent diffusion coefficient of strontium between 5 ? 10−12m2/s and 1 ? 10−11m2/s.No reliable value is obtained for the product ηR of the diffusion accessible porosity and theretardation factor R. For one of the through-diffusion experiments, the concentration decrease inthe inlet as a function of time was fitted simultaneously with the strontium profile in the clay,leading to a ηR value around 400. Estimating ηR at the inlet/clay interface as the ratio of thebulk concentration and the pore water concentration leads to a similar value. The valuesobtained from the strontium profiles in the percolation and electromigration experiments are inline as well. However, fitting for both through-diffusion tests the outlet concentrations versustime leads to very low and unrealistic values of ηR (0.15 and 0.5).Modeling shows that the transport of strontium in Boom Clay cannot be satisfactorilydescribed with the current assumptions (like e.g. instantaneous linear sorption equilibrium andboundary conditions), meaning that there is a problem to obtain a reliable value for the product ηR for strontium in Boom Clay.

Consistency of the strontium transport parameters in Boom Clay obtained from different types of experiments: accounting for the filter plates

2012 ◽  
Vol 1475 ◽  
Author(s):  
Marc Aertsens ◽  
Joan Govaerts ◽  
Norbert Maes ◽  
Liesbeth Van Laer
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Tritiated Water ◽  
Capacity Factor ◽  
Retardation Factor ◽  
Transport Parameters ◽  
Boom Clay ◽  
Different Types ◽  
Apparent Diffusion ◽  
Through Diffusion

ABSTRACTIn a previous MRS paper, the consistency of migration parameters for strontium (Sr) in Boom Clay, obtained by different types of experiments, was examined. No consistent value could be obtained for the product ηR of the diffusion accessible porosity η and the retardation factor R. Furthermore the nearly flat concentration profile measured in one of the through diffusion experiments could not be explained by the traditional through diffusion model. A reason is that the filter plates confining the clay sample have not been taken into account.Therefore, for Sr and tritiated water (HTO), the apparent diffusion coefficient and the product ηR in the filters are measured in through diffusion experiments on filter plates.Taking into account the filter plates, the outlet fluxes and the Sr profiles in the clay of both Sr through diffusion experiments, are described well with (i) the previously estimated Sr apparent diffusion coefficient in the clay of 7 × 10-12 m2/s, (ii) an apparent filter diffusion coefficient in the range 2 × 10-12 m2/s to 5 × 10-11 m2/s (vs. 1 × 10-11 m2/s measured in the filter through diffusion experiments), (iii) a clay capacity factor ηR in the range between 5000 and 22000, and (iv) a filter capacity factor between 0.3 and 0.6 (in agreement with the filter through diffusion measurements). However, using the above parameters, the evolution at the inlet could not be described. So although inconsistency diminished, some inconsistency remains.

CORALUS: An Integrated In Situ Corrosion Test on α-Active Glass

1997 ◽  
Vol 506 ◽  
Author(s):  
Pierre Van Iseghem ◽  
Elie Valcke ◽  
Nicole Godon ◽  
Norbert Jockwer
Keyword(s):  
Storage Conditions ◽  
Current Status ◽  
Research Facility ◽  
Geologic Repository ◽  
Boom Clay ◽  
Geologic Disposal ◽  
Different Types ◽  
Backfill Materials ◽  
Clay Formation

ABSTRACTAs part of the evaluation of the safety of the geologic disposal of HLW glass, a new in situ test on α-active glass will be started up in the underground research facility HADES (SCK•CEN, Mol, Belgium), situated in the Boom Clay formation, at a depth of 223 m. Besides a demonstration of the safe disposal of HLW glass containers in Boom Clay formation, the overall objective of this CORALUS test (CORrosion of Active gLass in Underground Storage conditions) is to study the performance of active HLW glass specimens in direct contact with different types of backfill materials, under conditions as representative as possible for those expected to prevail in a geologic repository in the Boom Clay formation. In order to meet this objective, the CORALUS test will integrate not only the experience of previous in situ tests performed at SCK•CEN and other research institutes, but also the expertise of the cooperating institutes. The paper presents the motivation for this new in situ test, its objectives, and the current status of its design

Overview of radionuclide migration experiments in the HADES Underground Research Facility at Mol (Belgium)

Clay Minerals ◽  
2013 ◽  
Vol 48 (2) ◽  
pp. 153-166 ◽  
Author(s):  
M. Aertsens ◽  
N. Maes ◽  
L. Van Ravestyn ◽  
S. Brassinnes
Keyword(s):  
Diffusion Coefficients ◽  
Large Scale ◽  
Laboratory Experiments ◽  
Small Scale ◽  
Transport Parameters ◽  
Research Facility ◽  
Apparent Diffusion Coefficients ◽  
Apparent Diffusion ◽  
Clay Formation

AbstractIn situ migration experiments using different radiotracers have been performed in the HADES Underground Research Facility (URF), built at a depth of 225 m in the Boom Clay formation below the SCK–CEN nuclear site at Mol (Belgium). Small-scale experiments, mimicking laboratory experiments, were carried out with strongly retarded tracers (strontium, caesium, europium, americium and technetium). Contrary to europium, americium and technetium which are subjected to colloid mediated transport, the transport of strontium and caesium can be described by the classic diffusion retardation formalism. For these last two tracers, the transport parameters derived from the in situ experiments can be compared with the laboratory-derived values. For both tracers, the apparent diffusion coefficients measured in the in situ experiments agree well with the laboratory-derived values.In the large-scale experiments (of the order of metres) performed in the URF, non-retarded or slightly retarded tracers (HTO, iodide and H14CO3–) were used. The migration behaviour of these tracers was predicted based on models applied in performance assessment calculations (classic diffusion retardation) using migration parameter values measured in laboratory experiments. These blind predictions of large-scale experiments agree well in general with the experimental measurements. Fitting the experimental in situ data leads to apparent diffusion coefficients close to those determined by the laboratory experiments. The iodide and H14CO3– data were fitted with a simple analytical expression, and the HTO data were additionally fitted numerically with COMSOL multiphysics, leading to about the same optimal values.

Pb Electrodeposition in the Presence of Chlorine Ions on Cu(100): An in Situ Optical Reflectivity Difference Study

2003 ◽  
Vol 781 ◽  
Author(s):  
J. Gray ◽  
W. Schwarzacher ◽  
X.D. Zhu
Keyword(s):  
Oblique Incidence ◽  
Opposite Sign ◽  
Bulk Phase ◽  
Phase Layer ◽  
Optical Reflectivity ◽  
Scan Rate ◽  
Different Types ◽  
Chlorine Ions ◽  
High Overpotentials

AbstractWe studied the initial stages of the electrodeposition of Pb in the presence of chlorine ions on Cu(100), using an oblique-incidence optical reflectivity difference (OIRD) technique. The OI-RD results reveal that immediately following the underpotential deposition (UPD) of the first Pb monolayer, two different types of bulk-phase films grow depending upon the magnitude of overpotential and cyclic voltammetry (CV) scan rate. At low overpotentials and/or slow scan rates, we propose that a bulk-phase Pb film grows on top of the UPD monolayer. At high overpotentials and/or fast scan rates, either a PbO, PbCl2, or a rough Pb bulk-phase layer grows on top of the UPD layer such that the reflectivity difference signal from such a film has an opposite sign.

scholarly journals Selected In Situ Hybridization Methods: Principles and Application

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 3874
Author(s):  
Dominika Veselinyová ◽  
Jana Mašlanková ◽  
Katarina Kalinová ◽  
Helena Mičková ◽  
Mária Mareková ◽  
...  
Keyword(s):  
In Situ Hybridization ◽  
Imaging Techniques ◽  
Cell Communication ◽  
Probe Design ◽  
Rapid Progress ◽  
In Situ Techniques ◽  
Different Types ◽  
Laboratory Procedures ◽  
The Individual

We are experiencing rapid progress in all types of imaging techniques used in the detection of various numbers and types of mutation. In situ hybridization (ISH) is the primary technique for the discovery of mutation agents, which are presented in a variety of cells. The ability of DNA to complementary bind is one of the main principles in every method used in ISH. From the first use of in situ techniques, scientists paid attention to the improvement of the probe design and detection, to enhance the fluorescent signal intensity and inhibition of cross-hybrid presence. This article discusses the individual types and modifications, and is focused on explaining the principles and limitations of ISH division on different types of probes. The article describes a design of probes for individual types of in situ hybridization (ISH), as well as the gradual combination of several laboratory procedures to achieve the highest possible sensitivity and to prevent undesirable events accompanying hybridization. The article also informs about applications of the methodology, in practice and in research, to detect cell to cell communication and principles of gene silencing, process of oncogenesis, and many other unknown processes taking place in organisms at the DNA/RNA level.

scholarly journals The Effect of Water Concentration in Ethyl Alcohol on the Environmentally Assisted Embrittlement of Austempered Ductile Irons

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 94
Author(s):  
Petar Janjatovic ◽  
Olivera Eric Cekic ◽  
Leposava Sidjanin ◽  
Sebastian Balos ◽  
Miroslav Dramicanin ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Cast Iron ◽  
Ultimate Tensile Strength ◽  
Ethyl Alcohol ◽  
Water Concentration ◽  
Different Types ◽  
Influence Of Water ◽  
Iron Material ◽  
Proof Strength

Austempered ductile iron (ADI) is an advanced cast iron material that has a broad field of application and, among others, it is used in contact and for conveyance of fluids. However, it is noticed that in contact with some fluids, especially water, ADI material becomes brittle. The most significant decrease is established for the elongation. However, the influence of water and the cause of this phenomenon is still not fully understood. For that reason, in this paper, the influence of different water concentrations in ethyl alcohol on the mechanical properties of ADI materials was studied. The test was performed on two different types of ADI materials in 0.2, 4, 10, and 100 vol.% water concentration environments, and in dry condition. It was found that even the smallest concentration of water (0.2 vol.%) causes formation of the embrittled zone at fracture surface. However, not all mechanical properties were affected equally and not all water concentrations have been critical. The highest deterioration was established in the elongation, followed by the ultimate tensile strength, while the proof strength was affected least.

Low diffusion level within a fibroadenoma as the sole sign of ductal carcinoma in situ: A case report

2021 ◽  
pp. 1-4
Author(s):  
Corrado Tagliati ◽  
Giuseppe Lanni ◽  
Federico Cerimele ◽  
Antonietta Di Martino ◽  
Valentina Calamita ◽  
...  
Keyword(s):  
Diffusion Coefficient ◽  
Apparent Diffusion Coefficient ◽  
Ductal Carcinoma In Situ ◽  
Carcinoma In Situ ◽  
Ductal Carcinoma ◽  
Surgical Excision ◽  
Small Region ◽  
Apparent Diffusion Coefficient Value ◽  
Apparent Diffusion

We present a case of ductal carcinoma in situ within a fibroadenoma. Breast cancer arising within fibroadenoma incidence ranges from 0.125% to 0.02%, and ductal carcinoma in situ is not the most frequent malignancy that can be found within a fibroadenoma. Dynamic contrast-enhanced magnetic resonance imaging showed an oval mass with circumscribed margins and dark internal septations, suspicious for fibroadenoma. According to European Society of Breast Radiology diffusion-weighted imaging consensus, mean apparent diffusion coefficient value obtained by drawing a small region of interest on the lesion apparent diffusion coefficient map showed a low diffusion level. Therefore, ductal carcinoma in situ within a fibroadenoma was diagnosed at final pathology after surgical excision.

Mixing and Comparative Properties of NR Compounds Filled with Different Types of Reinforcing Fillers

2017 ◽  
Vol 266 ◽  
pp. 172-176
Author(s):  
Pattarawadee Maijan ◽  
Nitinart Saetung ◽  
Wisut Kaewsakul
Keyword(s):  
Carbon Black ◽  
Silica Surface ◽  
High Viscosity ◽  
Cure Rate ◽  
Modified Silica ◽  
Reinforcing Fillers ◽  
Silane Coupling ◽  
Different Types ◽  
Cure Time

Mixing behaviors of the compounds filled with different reinforcing fillers were studied in correlation with compound and vulcanizate properties. Four filler systems were used including: 1) silica plus small amount of silane coupling agent; 2) carbon black; 3) pre-modified silica; and 4) silica+silane-carbon black mixed one. The results have shown that silica provides longer optimum cure time and shorter cure rate than carbon black due to accelerator adsorption on silica surface. In addition, owing to highly polar nature on silica surface the silica-based compounds show rather high viscosity, attributed to stronger filler-filler interaction as can be confirmed by Payne effect and reinforcement index. However, the commercial surface treatment or pre-modified form of silica shows superior properties than in-situ modification of silica by silane during mixing, while it gives comparable properties to carbon black-based compound. Tensile properties of vulcanizates show a good correlation with the basic properties of their compounds.

Vertical distribution of HTO and 125I− transport parameters in Boom Clay in the Essen-1 borehole (Mol, Belgium)

2013 ◽  
Vol 65 ◽  
pp. 90-97
Author(s):  
M. Aertsens ◽  
N. Maes ◽  
S. Labat ◽  
M. Van Gompel ◽  
T. Maes
Keyword(s):  
Vertical Distribution ◽  
Transport Parameters ◽  
Boom Clay

The mineralogy and firing behaviour of pottery clays of the Lake Van region, eastern Turkey

Clay Minerals ◽  
2017 ◽  
Vol 52 (4) ◽  
pp. 453-468 ◽  
Author(s):  
A. Aras ◽  
S. Kiliç
Keyword(s):  
East Coast ◽  
Chemical Characterization ◽  
Mineralogical Composition ◽  
Lake Van ◽  
X Ray Diffraction ◽  
Pottery Production ◽  
X Ray ◽  
Different Types ◽  
Firing Shrinkage

AbstractThe present study focused on the mineralogical and chemical characterization and firing behaviour of clays from the Lake Van region and compared them with the same characteristics established for two ancient pot sherds. Four pottery clays collected from Kutki and Kuşluk in the Kesan Valley to the south, from Kavakbaşı to the southwest and from Bardakçı village on the east coast of Lake Van were analysed by X-ray diffraction to identify mineralogical composition (bulk clays and <2 μm fractions after heating at 300–500°C and ethylene glycol solvation). Further analyses were conducted to determine the size distribution, chemical composition and physical properties of test bodies derived from these clays. The in situ weathered schist forming the primary micaceous red clays which are suitable for local pottery production are characterized by large muscovite-sericite-illite and small calcite contents. In contrast, the Bardakçı clays are dominated by large smectite contents and are only used sparingly in mixtures of local pottery production because they undergo firing shrinkage and present drying and firing flaws in the fired bodies. Firing ranges of ~800–900°C were inferred from the mineralogy and colours of the two ancient sherds from Kutki. As a result of mineralogical analysis of fired and unfired test bodies of these pottery clays and pot sherds, two different types of pastes were determined for pottery production in the Lake Van region: metamorphic and volcanic paste, the former characterized by a calcite-poor and mica-sericite-rich matrix and the latter by large smectite and small calcite contents.

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