In a previous report, we proposed a group test procedure that would minimize exposure to personnel leak-testing sealed radium sources by reducing the required number of tests. The procedure was based on two assumptions: (a) there will be at most a single leaking source in any given test group, and (b) the resulting exposure is directly proportional to the number of leak tests performed. Whereas the validity of the first assumption finds its basis in leak test data available in the literature, the requirement of the second assumption may not be readily satisfied.In the present work, this requirement is lifted and consideration is given to the more realistic situation where the exposure is directly proportional to the activity of the group being tested. This leads to a group leak-testing procedure which in many instances results in a considerable reduction in exposure.Consideration is also given to storage arrangements and it is shown that, given an inventory of sealed radium sources, minimum exposure during leak-testing results when the distribution of sources among drawers is as alike as possible with respect to the number, arrangement, and activity of the sources per drawer-assuming use of our recommended leak-testing procedure

During the 7th European Conference on Protection Against Radon at Home and at Work held in the autumn of 2013 in Prague, the second intercomparison of measuring instruments for radon and its short-lived decay products and the first intercomparison of radon/thoron gas discriminative passive detectors in mix field of radon/thoron were organised by and held at the Natural Radiation Division of the National Radiation Protection Institute (NRPI) in Prague. In total, 14 laboratories from 11 different countries took part in the 2013 NRPI intercomparison. They submitted both continuous monitors for the measurement of radon gas and equivalent equilibrium radon concentration in a big NRPI chamber (48 m3) and sets of passive detectors including radon/thoron discriminative for the measurement of radon gas in the big chamber and thoron gas in a small thoron chamber (150 dm3).

The cost-effectiveness of remedial and preventive countermeasures against indoor radon in the frame of the Czech Radon Programme is preliminarily estimated, resulting in 72 700 CZK and 194 000 CZK per y of life gained by remediation and prevention, respectively, (exchange rate approximately 28 CZK/EUR).

2014 Pour interpréter les résultats expérimentaux obtenus par R. P. E. [1] sur le complexe de transfert de charge chloranile-para-phénylène diamine, nous proposons un modèle susceptible de rendre compte de l'existence de l'état singulet et de l'état triplet thermiquement accessible, ainsi que de la très forte anisotropie du facteur g. L'existence pour le complexe de deux sous-réseaux mutuellement imbriqués nous a suggéré l'emploi d'un système de fonctions d'onde particulières : les orbitales alternantes. L'accord de la théorie proposée avec l'expérience est bon, sauf pour g, ce qui peut d'ailleurs s'expliquer par le caractère très grossier des approximations faites. Abstract. 2014 In order to explain the results of the E. P. R. experiments made on the chargetransfer chloranil-para-phenylene diamine complex, we give a theoretical scheme able to take into account the existence of a singlet and a thermically reachable triplet state, as well as the strong anisotropy of g factor. The existence of two alternant sublattices has suggested us to use particular wave functions, namely alternant orbitals. The theory we présent is in good agreement with experiments, except for g, which, moreover, can be explained from the very rough character of the approximations we have made.

AbstractsWe report an attempt of ab initio computation for the ground-state wave-function of a few organic semiconductors (namely T C N Q salts and the PDC charge transfer complex) for which we show that electrical conduction appears to look strongly like that of a band-gap semiconductor.Nous prtsentons un essai de calcul ab initio de la fonction d'onde de ]'&tat fondamental de quelques semiconducteurs organiques (complexe de transfert de charge CPPD ou sels du T C N Q pour lesquels nous montrons que la conduction tlectrique parait itre trks semblable a celle des semiconducteurs de bandes classiques.Wir beschreiben eine ab znitio Berechnung der Wellenfunktion des Grundzustandes einiger organischen Halbleiter (Komplexe mit T C N Q oder Ladungsubertragungskomplexe). Fur die elektrische Leitung ist die Ahnlichkeit zwischen diesen Komplexen und Halbleitern des Bandermodells ganz besonders gross.