Capability of the Kd model to predict radionuclides behaviour and transport in unsaturated columns under steady flow conditions

In the frame of the IRSN Chernobyl Pilot Site Project, a waste trench containing hot particles was instrumented to study the fate of radioactive pollutants. Results have shown the formation of a 90Sr plume in the downstream aquifer, mainly present in the Aeolian layer after 15 years. Laboratories experiments were performed to analyse the transport of 90Sr and 137Cs in the Aeolian sand in both saturated and unsaturated conditions. Batch experiments were performed to study the chemical equilibrium state of the soil/solution system under static conditions. Stirred flow-through reactor experiments were performed to study the kinetics and reversibility of sorption reactions at the surface of solid particles under dynamic conditions. Column experiments in the structured porous media were also performed in saturated and unsaturated flow conditions. Experimental data pointed out a non-linear, instantaneous and reversible sorption process of 90Sr. 137Cs exhibits a non-linear behaviour with a partial irreversible sorption process. A suitable cation-exchange model was used to describe the solute/soil reactions. The former model was coupled with transport models to describe behaviour of 90Sr and 137Cs in both saturated and unsaturated steady flow conditions. Main transport parameters were identified and discussed. An effective simple Kd type approach to describe radionuclides transport properties under unsaturated conditions was evaluate

The use of the N, N-diethyldodecanamide for actinide extractionin conjunction with liquid scintillation counting

If simplified, every information retrieval problem can be solved when the information need implied by its expression has been identified. We are interested in the criteria used in realising a good information retrieval problem expression. We have listed these criteria through some principles and maxims which first characterized the communication between two persons are applied. We choose to use the gricean maxims because they are the most favoured for this type of situation. Secondly, we have tried to identify some others principles that can be used to realise a good information retrieval problem expression. The principles by Grice can not resolve all forms of error associated with this particular form of communication. In our work, we defined three other principles namely: adhesion principle, reformulation principle, memorization principle. We give some examples of situations where the principles we have formulated are not applicable and the consequences. We present the possible applications of our new model: MIRABEL, which can help in the description of information retrieval problem from. It also compels its user to use essential good expression principle implicitly

Comportement d'une interface UO2/eau sous irradiation : effets de la radiolyse de l'eau sur l'altération de UO2

Le comportement d'une interface UO2/eau sous irradiation a été étudié en utilisant un faisceau d'ions 4He2+ produit par un cyclotron. Les effets de la radiolyse alpha sur l'altération de UO2 dans de l'eau aérée déionisée ont été examinés en caractérisant parallèlement la chimie des solutions irradiées et la surface de UO2. Un effet du faisceau d'ions 4He2+ sur la chimie de la solution a été observé : la quantité d'uranium relâchée augmente tandis que le pH diminue sous irradiation. De plus, de fortes concentrations de peroxyde d'hydrogène produites par radiolyse ont été mesurées dans les solutions irradiées. La caractérisation de la surface du solide a permis de mettre en évidence la formation d'un produit d'altération, identifié comme étant un peroxyde d'uranium hydraté (UO4.2H2O), lié directement à la présence en solution de fortes concentrations d'uranyl et de peroxyde d'hydrogène au voisinage de l'interface UO2/eau

Affections non-directement attribuables à la sclérodermie systémique (ANDAS) diagnostiquées au cours du suivi dans un centre de compétence: à propos d'une cohorte de 200 patients

National audienceIntroduction - Our work aimed to investigate the illnesses unrelated to systemic sclerosis (IUSS), diagnosed among patients with systemic sclerosis (SSc) throughout their follow-up in a referral tertiary care center. Methods - All the patients with SSc followed in the Internal Medicine Department of the University Hospital between October, 2014 and December, 2015, were included. We specifically reviewed the medical records of the patients who exhibited IUSS, defined as an illness that could not be considered as a typical clinical manifestation or as a usual complication of the disease. Results - Two hundred patients were included, and 38 IUSS were diagnosed among 31 SSc patients, over a 4 years median follow-up period. These diagnoses included vascular diseases (26%), heart diseases (21%), neoplasia (8%), infectious diseases (6%), autoimmune diseases (5%), endocrinopathies (5%), and others (24%). The median follow-up time before IUSS diagnosis was two years. Seventeen (45%) of these diagnoses were considered in patients showing suggestive clinical signs. A specific therapy was delivered in 25 cases (66%). Group comparisons revealed that dyslipidemia was more frequent in patients with IUSS (OR = 2.6 [1.1-1.5]; p = 0.014), while no differences were found for the other characteristics. Especially, no association between auto-antibodies specificity and the occurrence of IUSS was found. Conclusion - This study focused on IUSS in SSc patients and highlights the need for a polyvalent clinical approach all along the follow up of SSc patients

Further Characterization of Clinical and Laboratory Features in VEXAS Syndrome: Large-scale Analysis of a Multicentre Case Series of 116 French Patients

International audienc