Beach sediments drift study by means of radioactive tracers; L'etude du transport littoral par la methode des traceurs radioactifs

Energy Technology Data Exchange (ETDEWEB)

Hours, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P [Electricite de France (EDF), 78 - Chatou (France). Lab. National d' Hydraulique

1959-07-01

The present state of the sediments drift studies by means of radioactive tracers is exposed. Various processes of labelling, immersion and detection, used in France and other countries, are reviewed. A more extended analysis of some aspects of the problem by the same authors can be found in 'La Houille Blanche', number 3, may-june 1959 (Rapport C.E.A. number 1269). (author) [French] L'etude du transport littoral des sediments et galets par la methode des traceurs radioactifs est en plein developpement. Le present rapport precise l'etat actuel de la question. Les techniques de marquage, d'immersion et de detection utilisees en France et a l'etranger sont decrites; une analyse plus detaillee de certains aspects de la question est presentee par les memes auteurs dans 'La Houille Blanche', numero 3, mai-juin 1959 (Rapport C.E.A. numero 1269). (auteur)

New instruments and methods for measuring the concentration of radioactive products in the atmosphere; Appareils recents et methodes nouvelles pour la mesure de la concentration des produits radioactifs dans l'atmosphere

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Jehanno, C; Blanc, A; Lallemant, C; Roux, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-01

) [French] Differents enregistreurs pour aerosols radioactifs ont ete realises pour mesurer la pollution de l'atmosphere des laboratoires ou l'atmosphere exterieure. EAR 600. - Permet de mesurer en continu instantanement et 3 a 10 heures apres le prelevement des concentrations d'aerosols emetteurs {alpha} ou {beta} allant de quelques 10{sup -11} a quelques 10{sup -8} curies par metre cube d'air. EAR 800. - Permet de mesurer en continu des concentrations d'aerosols emetteurs {alpha} allant de 10{sup -11} a 10{sup -5} curie par metre cube d'air, et des concentrations d'aerosols emetteurs {beta} allant de 10{sup -11} a 10{sup -1} curie par metre cube d'air. EAR PLUTONIUM. - Permet de detecter en quelques minutes 1000 DMP (2.10{sup -9} curie par metre cube) et en 8 heures 1 DMP (2.10{sup -12} curie par metre cube). Deux methodes sont utilisees pour separer l'activite due au plutonium de celle due aux derives du radon et du thoron: a) par discrimination d'amplitude, b) par les coincidences (a,b) RaC' et ThC-ThC'. SP 4. - Monte sur jeep, cet ensemble permet la mesure de l'irradiation produite au sol par le panache des piles. La sensibilite est de 5{mu}R/h. A.D.I.R. - Cet appareil autonome et portatif est destine a la mesure instantanee des teneurs en radon de l'atmosphere des mines. Il permet de mesurer des teneurs de l'air variant entre 0,4 et 400.10{sup -10} curie par litre d'air (0,4 et 400 DPM). La mesure des retombees radioactives est faite apres collection de cette activite par un pluviometre special comportant une surface adhesive et une cartouche de resines echangeuses d'ions. La radioactivite des retombees varie entre quelques 10{sup -9} et quelques 10{sup -7} curie par metre carre et par mois. La mesure des concentrations de l'atmosphere en produits de fission est faite apres collection sur papier filtre. Les concentrations mesurees dans l'air au niveau du sol varient entre 10{sup -13} et 10{sup -12} curie par metre cube. (auteur)

Safety apparatus for serious radioactive accidents (1962); Materiel d'intervention en cas d'accident radioactif grave (1962)

Energy Technology Data Exchange (ETDEWEB)

Estournel, R; Rodier, J [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1962-07-01

In the case of a serious radioactive accident, radioactive dust and gases may be released into the atmosphere. It is therefore necessary to be able to evaluate rapidly the importance of the risk to the surrounding population, and to be able to ensure, even in the event of an evacuation of the Centre, the continuation of the radioactivity analyses and the decontamination of the personnel. For this, the Anti-radiation Protection Service at Marcoule has organised mobile detection teams and designed a mobile laboratory and a mobile shower-unit. After describing the duty of the mobile teams, the report gives a description of the apparatus which would be used at the Marcoule Centre in the case of a serious radioactive accident. The method of using this apparatus is given. (authors) [French] Lors d'un accident radioactif grave, des poussieres et des gaz radioactifs peuvent etre relaches dans l'atmosphere. II est alors indispensable d'evaluer rapidement l'importance du risque couru par les populations environnantes, et de pouvoir assurer, meme dans le cas de l'evacuation du Centre, la poursuite des analyses radioactives et la decontamination du personnel. Pour cela, le Service de Protection contre les Radiations du Centre de Marcoule a mis sur pied des equipes mobiles de detection et realise une semi-remorque laboratoire ainsi qu'une semi-remorque douches. Apres avoir defini la mission des equipes mobiles, le rapport donne la description du materiel d'intervention qui serait mis en oeuvre par le Centre de Marcoule dans le cas d'un accident radioactif grave. Il precis le mode d'utilisation de ce materiel. (auteurs)

Origin, Nature, Disposal and Control of Radioactive Wastes Arising from the Use of Radioisotopes; Origine, Nature, Elimination et Controle des Dechets Radioactifs Decoulant de l'Emploi des Radioisotopes; 041f 0420 041e 0414 ; Origen, Naturaleza, Evacuacion y Control de los Desechos Radiactivos Producidos en la Utilizacion de Radioisotopos

Energy Technology Data Exchange (ETDEWEB)

Kenny, A. W. [Ministry of Housing and Local Government (United Kingdom)

1960-07-01

The paper describes the different types of radioactive waste arising from industrial, medical and scientific uses of radioisotopes. An outline is given of methods used for waste disposal, depending on the content of radioactivity. (author) [French] L'auteur decrit les differents types de dechets radioactifs decoulant de l'utilisation de radioisotopes dans l'industrie, en medecine et dans la science. Il donne un apercu des methodes employees pour l'elimination des dechets selon leur teneur en elements radioactifs. (author) [Spanish] En la memoria se describen los diferentes tipos de desechos radiactivos producidos por la utilizacion industrial, medica y cientifica de los radioisotopos y se hace una exposicion de los metodos empleados para la evacuacion de desechos segun su contenido radiactivo. (author) [Russian] V doklade daetsja opisanie razlichnyh tipov radioaktivnyh othodov, voznikajushhih v rezul'tate promyshlennogo, medicinskogo i nauchnogo ispol'zovanija radioizotopov. Osobo razbirajutsja metody, ispol'zuemye dlja udalenija radioaktivnyh othodov v zavisimosti ot ih radioaktivnosti. (author)

Treatment and final conditioning of solid radioactive wastes; Traitement et conditionnement definitif des dechets radioactifs solides

Energy Technology Data Exchange (ETDEWEB)

Cerre, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The storage of solid radioactive wastes on a site is so cumbersome and dangerous that we have developed a method of treatment and conditioning by means of which the volume of waste is considerably reduced and very long-lasting shielding can be provided. This paper describes the techniques adopted at Saclay, where the wastes are sheared, compressed and enveloped in concrete of variable thickness. The main part of the report is devoted to a description of the corresponding remote handling installation. (author) [French] L'encombrement et le danger que presentent sur un site le stockage de dechets radioactifs solides nous ont amenes a etudier un mode de traitement et de conditionnement permettant une sensible reduction du volume des dechets et une protection de tres longue duree. La presente communication expose les techniques adoptees a Saclay ou les dechets sont cisailles, comprimes et enrobes dans du beton d'epaisseur variable. La description de l'installation telecommandee correspondante fait l'objet principal de cette communication. (auteur)

Elimination of slightly radioactive liquid effluent by dilution. Its consequences (1960); Elimination par dilution d'effluents liquides faiblement radioactifs. Leurs consequences (1960)

Energy Technology Data Exchange (ETDEWEB)

Bovard, P; Candillon, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Nuclear centres often have to solve problems raised by the elimination of large volumes of slightly radioactive liquid effluent. As things stand at present, the method usually adopted consists in expelling this effluent into the main water system in order to dilute it to a maximum, and thus to lower its radioactive isotope concentration to below the norms imposed by the Public Health Service. This technique requires systematic checking of the water system and its dependences, and demands a thorough knowledge of adsorption and fixation processes. (author) [French] Les centres nucleaires ont frequemment a resoudre des problemes poses par l'elimination de volumes importants d'effluents liquides faiblement radioactifs. Dans l'etat actuel des choses, la solution la plus utilisee consiste a rejeter ces effluents dans le reseau hydrographique de maniere a les diluer au maximum et abaisser ainsi leurs teneurs en isotopes radioactifs au-dessous des normes imposees par la Sante Publique. Cette technique necessite un controle systematique du reseau et de ses dependances et demande une connaissance approfondie des processus d'adsorption et de fixation. (auteur)

Tests of the use of cation exchange organic resins for the decontamination of radioactive aqueous effluents; Essais d'emploi des resines organiques echangeuses de cations pour la decontamination des effluents aqueux radioactifs

Energy Technology Data Exchange (ETDEWEB)

Bourdrez, Jean; Girault, Jacques; Wormser, Gerald

1962-12-14

The authors report tests performed in laboratory and results obtained during an investigation of the use of synthetic ion exchangers for the decontamination of radioactive effluents of moderate activity level and with a non neglectable salt loading. Resins are used under sodium form and regenerated after each fixing operation. Once decontaminated and free of its disturbing ions, the regenerating agent (NaCl) is used for several operations. The authors present the used resins, the treated effluents, describe the tests, and discuss the obtained results [French] Dans ce rapport nous faisons le point des essais et resultats obtenus au laboratoire au cours d'une etude concernant l'utilisation des echangeurs d'ions synthetiques pour la decontamination des effluents radioactifs de niveau d'activite moyenne et de charge en sels non negligeable. Les resines sont employees sous forme sodique et regenerees apres chaque operation de fixation. Le regenerant decontamine et debarrasse de ses ions genants est utilise pour plusieurs operations d'elution. Les seuls residus a stocker proviennent d'une part eventuellement d'un pretraitement de l'effluent, d'autre part, dans tous les cas des precipites consecutifs a la purification de l'eluant dont le traitement chimique est plus aise et donne lieu a des boues beaucoup moins volumineuses qu'une coprecipitation effectuee sur la totalite de l'effluent. (auteurs)

Some examples of the use of radioactive tracers in pharmacodynamic; Quelques exemples de l'emploi des traceurs radioactifs en pharmacodynamie

Energy Technology Data Exchange (ETDEWEB)

Cohen, Y [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The study of absorption, of distribution in the organism and of the elimination of a medicament has been greatly facilitated by the development of nuclear applications. In effect, the introduction into the molecule of one or several radioactive atoms makes it possible to follow the path and destination of minute quantities of the drug and to thus carry out analyses on the animal within limits of posology close to those of therapeutics. However the qualitative or quantitative methods used have certain limits and they must be compared amongst themselves and with others. Some examples will show : - the importance of the way of administering the drug on the changes in the distribution; - the quite relative selectivity of this latter; - and lastly, the different process involved in the elimination mechanisms. (author) [French] L'etude de l'absorption, de la repartition dans l'organisme et de l'elimination d'un medicament s'est trouvee grandement facilitee par le developpement des applications nucleaires. En effet, l'introduction dans une molecule d'un ou plusieurs atomes radioactifs permet de suivre le sort de quantites infimes de la drogue et de ce fait d'en effectuer l'analyse chez l'animal dans des limites de posologie se rapprochant de celles de la therapeutique. Cependant les methodes employees, qualitatives ou quantitatives, presentent des limites et doivent etre confrontees entre elles et avec d'autres methodes. Quelques exemples mettront en evidence: - l'importance du mode d'administration sur l'evolution de la repartition, - l'electivite toute relative de cette derniere, - et enfin, les modalites diverses des mecanismes d'elimination. (auteur)

A Study Of The Dilution Of Radio-Active Waste In The Rhone (1961); Etude de la dilution dans le rhone des effluents radioactifs du Centre de Marcoule (1961)

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Scheidhauer, J; Marichal, M; Court, R [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1961-07-01

The discharge into the Rhone of liquid radio-active waste from the Marcoule Centre necessitates a large number of measurements, in particular chemical and radio-chemical analysis of the waste, itself and of the waters of the Rhone both above arid below the point of discharge. The results thus obtained during 1960 made it possible to evaluate the total amount of active waste discharged and its dilution in the receiving medium. A statistical study of the results of the analysis of the Rhone waters shows that a satisfactory dilution of the waste occurs rapidly; the experimental results obtained with an experimental discharge of rhodamine are thus confirmed. (authors) [French] Le rejet au Rhone des effluents radioactifs liquides produits sur le Centre de Marcoule donne lieu a un grand nombre de mesures et en particulier d'analyses chimiques et radio-chimiques des effluents eux-memes ainsi que des eaux du Rhone avant et apres rejet. Au cours de l'annee 1960, l'ensemble des resultats ainsi obtenus a permis de dresser un bilan des activites rejetees et de leur dispersion dans le milieu recepteur. Une etude statistique des resultats d'analyses des eaux du Rhone montre qu'une dilution satisfaisante des effluents s'effectue rapidement confirmant ainsi les resultats obtenus lors d'un rejet experimental de rhodamine. (auteurs)

Treatment and storage of contaminated materials; Traitement et stockage des materiels contamines

Energy Technology Data Exchange (ETDEWEB)

Cerre, P; Pomarola, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

The ultimate disposal of radioactive wastes sets an important problem which has been partly solved. France has temporarily adopted the following method: 1) Volume reduction, 2) Fixation of the activity in non leakable solids standing all temporarily or ultimate kinds of storing. According to those two basic principles the authors have presented: - a decontamination plant allowing maximum recovery of materials, - the plans of an installation devised for carrying out radioactive waste volume reduction and conditioning. Both of them are being built at Saclay. (author) [French] La destination finale des residus radioactifs pose un probleme imparfaitement resolu. La France a adopte, comme solution d'attente, le processus ci-dessous: 1) Reduction des volumes, 2) Confinement de l'activite dans des solides non lechables et pouvant resister a tous modes de stockage provisoire ou definitif. A partir des idees directrices, MM. CERRE et POMAROLA ont presente: - un batiment de decontamination permettant de recuperer le maximum de materiaux, - un projet d'installation visant a la reduction du volume des dechets radioactifs et leur conditionnement. Ces deux installations sont en cours d'execution a Saclay. (auteur)

Usefulness of the decay rate in the management of radioactive waste stocks; De l'interet de la decroissance pour la gestion des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Cohendy, G [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

1969-07-01

It became apparent, during first few years operation of the Marcoule Centre, that it was very useful to exploit the natural decay rate of the radioactive element contaminating the waste. The storage of this waste under the best possible conditions in each case, was first of all favorable for the radiological safety point of view; it led, furthermore, to a marked reduction in the cost price since it made it possible to avoid employing protection means which would have proved to be excessively outsize after a few years. Finally, even when the half-life of the radioelements involved seemed to annul any possible advantages of this method, the temporary storage made it possible to develop treatment processes which were unknown at the time. The overall result of this policy is that at the present time over 98 per cent of the solid waste produced by the Marcoule Centre has been processed in such a way that it can, at any moment, be discharged from the site without difficulty. (authors) [French] Des les premieres annees de fonctionnement du Centre de Marcoule, il est apparu qu'il etait extremement benefique de mettre a profit la decroissance naturelle des elements radioactifs contaminant les dechets. Le stockage de ces dechets dans des conditions appropriees a chaque cas d'espece a tout d'abord ete favorable a la surete radiologique; en outre, il a abouti a une reduction sensible des prix de revient, du fait qu'il a evite de mettre en oeuvre des moyens de protection qui se seraient reveles surdimensionnes au bout de quelques annees. Enfin, meme lorsque la periode des radioelements en cause semblait enlever tout interet a cette methode, le stockage d'attente a permis de mettre au point des procedes de traitement inconnus a l'epoque. Le resultat global de cette politique est que, actuellement, plus de 98 pour cent des dechets solides produits depuis l'origine du Centre de Marcoule ont ete conditionnes de telle sorte qu'ils peuvent, a tout moment, etre evacues hors du Site

Sr{sup 90} determination in calcareous water; Determination du {sup 90}Sr dans des eaux chargees en calcium

Energy Technology Data Exchange (ETDEWEB)

Cohen, P; Pardo, G; Wormser, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The Straub method (ref. 2) for determination of radioactive strontium in water containing calcium is valid within very wide limits, and particularly in the case of residual water from the chemical purification treatment of the radioactive liquid effluent at the C.E.N. Saclay. (author) [French] La methode de Straub (ref. 2) de determination du strontium radioactif dans une eau chargee en calcium est valable dans des limites tres larges et en particulier dans le cas d'eaux residuaires provenant du traitement d'epuration chimique des effluents liquides radioactifs du C.E.N. de Saclay. (auteur)

Ventilation of radioactive enclosures; Ventilation des enceintes radioactives

Energy Technology Data Exchange (ETDEWEB)

Caminade, F; Laurent, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

Mechanical, physical and chemical manipulations on radioactive products must be carried out in properly ventilated enclosed places. The air extracted can only be discharged into the atmosphere after a correct filtration. The power of the ventilation systems is a function of the dimensions and purpose of the enclosure? The choice of types of filter is determined by the physical state and chemical nature of the radioactive materials to be manipulated. This study deals with the individual equipment of small installations: glove boxes, manipulation boxes with outside control and, if necessary, production chambers (maximum useful volume: 5 m{sup 3}). The performances of three types of 'ventilators', and the modifications provided by the addition of filters, are measured and compared. (author) [French] Les manipulations oceaniques, physiques et chimiques sur des produits radioactifs doivent s'effectuer dans des enceintes convenablement ventilees. L'air extrait ne peut etre rejete dans l'atmosphere qu'apres une filtration correcte. La puissance des installations de ventilation est fonction des dimensions de l'enceinte et de son utilisation. Le choix des types de filtres est determine par l'etat physique et la nature ehimique des corps radioactifs manipules. Notre etude porte sur l'equipement individuel d'installations de petites dimensions: boites a gants, boites a pinces et, a la rigueur, enceintes de production (volume maximum utilisable 5 m{sup 3}). Nous mesurons et comparons les performances de trois types de 'ventilateurs' et les modifications apportees par l'adjonction de filtres. (auteur)

A treatment station for solid radio-active waste at the Saclay nuclear research centre (1962); Station de traitement des dechets radioactifs solides au centre d'etudes nucleaires de Saclay (1962)

Energy Technology Data Exchange (ETDEWEB)

Cerre, P; Mestre, E; Lebrun, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

The waste from an atomic centre is very varied in nature, in form, and in activity, going from weakly contaminated laboratory waste to objects actuated in a pile and strongly radioactive. After one year's working of a pilot plant, a factory has been built, in which solide waste is treated and then conditioned in concrete blocks. The present communication describes the treatment and conditioning techniques in this factory which uses to a maximum remotely controlled operation. (authors) [French] Les dechets d'un Centre Atomique sont de natures, de forme et d'activites extremement variees, allant des dechets de laboratoires faiblement contamines, aux dispositifs actives en pile et fortement radioactifs. Apres l'exploitation pendant un an d'une unite pilote, une usine a ete construite dans laquelle les dechets solides sont traites, puis conditionnes en bloc de beton. La presente communication a pour objet la description des techniques de traitement et de conditionnement dans cette usine ou les operations sont au maximum commandees automatiquement et a distance. (auteurs)

The effluent problem in a plutonium production centre; Probleme des effluents d'un centre de production de plutonium

Energy Technology Data Exchange (ETDEWEB)

Galley, R; Cantel, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The first part of the report is devoted to generalities: the geographical situation of the Marcoule Centre, the sources of radio-active effluent, methods of treating this effluent. In the second part the authors gives a detailed description of the various installations in the Radio-active Effluent Treatment Station at the Marcoule Centre, and outline the conditions governing the rejection of treated effluent into the Rhone. A few lines are given to comparisons between the results obtained from the use of these installations up till may 1959 and the expected results published by the same authors at the Brussels Conference (1956). In conclusion the authors lay down some of the essential principles, applicable to the study of new installations. (author) [French] La premiere partie du rapport est consacree a quelques generalites: situation geographique du Centre de Marcoule, provenance des effluents radioactifs, methodes de traitement de ces effluents. Dans la seconde partie, les auteurs presentent une description detaillee des diverses installations de la Station de Traitement des Effluents radioactifs du Centre de Marcoule et precisent les conditions de rejet dans le Rhone des effluents radioactifs traites. Quelques lignes sont consacrees aux comparaisons entre les resultats de l'exploitation des installations jusqu'en mai 1959 et les previsions publiees par les memes auteurs a l'occasion de la Conference de Bruxelles (1956). En conclusion, les auteurs donnent quelques principes essentiels, applicables a l'etude de nouvelles installations. (auteur)

Count rate balance method of measuring sediment transport of sand beds by radioactive tracers; Methode du bilan des taux de comptage d'indicateurs radioactifs pour la determination du debit de charriage des lits sableux

Energy Technology Data Exchange (ETDEWEB)

Sauzay, G [Commissariat a l' Energie Atomique, 91 - Saclay (France). Centre d' Etudes Nucleaires

1967-11-01

Radioactive tracers are applied to the direct measurement of the sediment transport rate of sand beds. The theoretical measurement formula is derived: the variation of the count rate balance is inverse of that of the transport thickness. Simultaneously the representativeness of the tracer is critically studied. The minimum quantity of tracer which has to be injected in order to obtain a correct statistical definition of count rate given by a low number of grains 'seen' by the detector is then studied. A field experiment was made and has let to study the technological conditions for applying this method: only the treatment of results is new, the experiment itself is carried out with conventional techniques applied with great care. (author) [French] Les indicateurs radioactifs sont appliques a la mesure directe du debit de charriage des lits sableux. On etablit la formule theorique de mesure: le bilan des taux de comptage varie en sens inverse de l'epaisseur de charriage. Parallelement on fait une etude critique de la representativite de l'indicateur, puis on determine la quantite minimale de traceur qu'il faut immerger pour que les taux de comptage fournis pour un faible nombre de grains 'vus' par le detecteur aient une definition statistique correcte. Une experience de terrain a permis d'etudier les conditions technologiques de cette methode: seul le depouillement des resultats est nouveau. L'experimentation in-situ se fait suivant les procedes classiques avec un tres grand soin. (auteur)

Determination of radioactive risks connected with the working of a nuclear plant; Evaluation des risques radioactifs lies au fonctionnement d'une installation nucleaire

Energy Technology Data Exchange (ETDEWEB)

Lavie, J M; Doury, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Numerous problems which are posed by the evaluation of the radioactive risks linked to the working of a nuclear plant are new problems which have not yet been satisfactorily solved. In these conditions this study must be considered only as a preliminary approach whose essential aims are the following: - development and synthesis of the existing data; - rapid determination of conservative and usable orders of greatness for the security factors, both for normal working and in the case of an accident. The most probable typical accidents are reviewed together with the nature of the resulting risks and the principal factors on which these risks depend. Among these factors, one of the most important is atmospheric diffusion which is studied in some detail using the analytic model due to Sutton. A logical graphical presentation increasing the flexibility in the use of the results and presents the responsible authorities with a flexible, practical and rapid means of evaluating the risks involved starting from a sufficiently general system of initial and simultaneously valid conditions (types of accident, atmospheric conditions). (author) [French] De nombreux problemes souleves par l'evaluation des risques radioactifs lies au fonctionnement d'une installation nucleaire sont des problemes nouveaux qui n'ont pas encore recu de solution satisfaisante. Dans ces conditions cette etude ne doit etre consideree que comme une premiere approche dont les objectifs essentiels sont les suivants: - mise au point et synthese de donnees existantes; - determination rapide d'ordres de grandeur conservatifs et utilisables de valeurs de securite, tant en fonctionnement normal qu'en cas d'accident. Les accidents types les plus probables sont passes en revue ainsi que la nature des risques qui en decoulent et les principaux facteurs dont dependent ces risques. Parmi ces facteurs, l'un des plus importants est la diffusion atmospherique qui fait l'objet d'une etude particuliere a l'aide du modele

357 Datation des carbonates impurs au Maroc à l'aide de la ...

African Journals Online (AJOL)

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Datation des carbonates impurs au Maroc à l'aide de la méthode de déséquilibre radioactif 230Th/234U. A. Choukri1, S. Semghouli1, O. Hakam1, M. Moheidine3 et M. Laatiris4. 1Laboratoire de Physique de la Matière et Rayonnement, Equipe de. Physique et Techniques Nucléaires, Faculté des Sciences, P.B 133,. 14000 ...

Contribution to the study of aerosol photometers, application to the measurement of filter efficiency; Contribution a l'etude des photometres a aerosols, application a la mesure de l'efficacite des filtres

Energy Technology Data Exchange (ETDEWEB)

Billard, F; Hadelaine, G

1968-01-01

The measurement of the quantity of diffused light by particulates in suspension in a gas allows to determine the concentration and the size of an aerosol. The aim of this work is to check the answer of the usual photometer in the laboratories, the Phoenix-Sinclair and the Royco-230. The minimum diameter of the particulates detected by these photometers is about 0.3 microns. [French] La mesure de la quantite de lumiere diffusee par des particules en suspension dans un gaz permet de determiner la concentration et les dimensions d'un aerosol. Le but de ce travail est de verifier la reponse du photometres d'usage courant dans les laboratoires, le Phoenix-Sinclair et le Royco-230. Le diametre minimum des particules detectees par ces photometres est d'environ 0, 3 microns. (auteurs)

Technical and Economic Problems Associated with the Development of Methods of Processing and Using Radioactive Waste; Problemes techniques et economiques lies au developpement des methodes de traitement et d'utilisation des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

Thiriet, L; Sauteron, J; Oger, C [Commissariat a l' Energie Atomique, Fontenay-Aux-Roses (France). Centre d' Etudes Nucleaires

1968-07-01

The paper briefly reviews the various techniques used in processing the radioactive wastes which unavoidably result from the generation of electric power from nuclear sources. The paper goes on to define the relative importance, in nuclear fuel cycles, of the problem raised by these wastes. Emphasis is placed on the economic influence of management policies on the cost of power generation, and hence on the relative position of nuclear energy. A substantial percentage of these wastes can be economically utilized. Attention is drawn to the major technical and economic features of the industry which will come into being as a result of this utilization. The major uses anticipated are discussed: radiation sources, heat sources, auxiliary power generation. The paper concludes that satisfactory solutions have already been found to these problems, and describes possible improvements. (author) [French] La communication rappelle d'abord succinctement les differentes techniques de traitement des dechets radioactifs resultant necessairement de la production d'electricite d'origine nucleaire. On situe ensuite l'importance du probleme pose par ces residus dans le cycle du combustible nucleaire. On fait ressortir l'influence economique du choix des methodes de gestion sur le cout de production de l'energie, et par consequent sur la place devolue a l'energie nucleaire. Une part importante de ces dechets peut faire l'objet d'une utilisation rentable de l'industrie qui naitra de cette utilisation. Les principales applications envisagees sont evoquees: sources d'irradiation, sources chauffantes, generateurs auxiliaires d'energie. On conclut que d'ores et deja des solutions satisfaisantes ont ete apportees a ces problemes, et l'on decrit les perspectives d'amelioration concevables. (auteur)

Kinetic ion exchange studies in ultramarines by the radioactive tracer method; Etudes cinetiques d'echanges d'ions dans les outremers par la technique des traceurs radioactifs

Energy Technology Data Exchange (ETDEWEB)

May, S; Goenvec, H; Pinte, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The possibility of ion exchanges in various ultramarines has been studied in the aqueous phase. The kinetics of the exchange reactions is followed by studying the behaviour of a radioactive ion, either in the solution of the exchanging salt or in the ultramarine itself. The sodium in the make-up of the ultramarine, is found to exchange with various ions in solution. The reaction speeds appear to be governed by a diffusion process inside the grains of ultramarine. The diffusion coefficients and the activation energies are determined for the exchanges studied. Several exchange studies were carried out in an organic medium. The kinetics of ion exchange is also investigated in ultramarines from which most of the constituent sulphur has been eliminated. The results obtained in these ultramarines are compared with the exchange kinetics of the same ions in ordinary ultramarine. (author) [French] Nous avons etudie la possibilite d'echanges ioniques dans differents outremers, en phase aqueuse. L'etude cinetique des reactions d'echanges est suivie en etudiant le comportement d'ion radioactif, soit dans la solution du sel echangeant, soit dans l'outremer lui-meme. C'est le sodium de constitution de l'outremer qui s'echange avec differents ions en solution. Les vitesses de reactions semblent etre controlees par un processus de diffusion a l'interieur des grains d'outremer. Les coefficients de diffusion et les energies d'activation sont determines pour les echanges etudies. Quelques etudes sont realisees en milieu organique ou quelques echanges ont ete etudies. La cinetique d'echange d'ions est egalement etudie dans des outremers dans lesquels la majorite du soufre de constitution a ete eliminee. On compare les resultats obtenus dans ces outremers avec les cinetiques d'echanges des memes ions dans l'outremer ordinaire. (auteur)

Study of the stopping power of various filters; Etude du pouvoir d'arret de differents filtres

Energy Technology Data Exchange (ETDEWEB)

Madelaine, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The first part is devoted to a study of aerosols obtained from the combustion of various smoke-producing compounds. A trial aerosol of which the size distribution is the closest possible to that of atmospheric dusts has been defined. The efficiency of various filters has been determined for successive increments of the dimensions and not for the whole range of its diameter distribution. The variation in the efficiency of the filtering layers as a function of the filtering speed and particle size has been studied for aerosols having particle diameters of over 0.3 {mu}. The second part describes an original method for measuring the efficiency of filters for ultra-fine particles (under 0.1 {mu}) using the fixation properties of radioactive atoms resulting from the decay of thoron. (author) [French] La premiere partie est consacree a l'etude des aerosols obtenus a partir de la combustion de divers types de fumigenes. Un aerosol d'essai, dont la repartition granulometrique se rapproche le plus possible des poussieres atmospheriques a ete defini. L'efficacite de plusieurs filtres a ete determinee pour des tranches successives de dimension et non pour l'aerosol pris dans sa totalite. La variation de l'efficacite des couches filtrantes en fonction de la taille des particules et de la vitesse de filtration a ete examinee pour des aerosols superieurs a 0,3 {mu}. La seconde partie decrit une methode originale permettant de mesurer l'efficacite des filtres pour des particules ultrafines (inferieures a 0,1 {mu}) en utilisant la propriete de fixation des atomes radioactifs des descendants du thoron. (auteur)

Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

Energy Technology Data Exchange (ETDEWEB)

Dupuis, M C; Charrier, G; Alba, C; Massimino, D [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1970-07-01

The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l'etude du phenomene chromatographique dans les conditions

Adsorption of fission products on mediterranean mud; Adsorption des produits de fission sur des vases de mediterranee

Energy Technology Data Exchange (ETDEWEB)

Cohen, P; Gailledreau, C [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Partition coefficients of some fission products have been measured in sea water on mud taken from the bottom of the Mediterranean sea. A discussion follows on the behaviour of these radioisotopes. (author) [French] On a mesure les coefficients de partage dans l'eau de mer de quelques produits de fission a longue periode sur des echantillons de vase preleves en Mediterranee. Les valeurs trouvees sont elevees. Le comportement de ces isotopes radioactifs est discutee. (auteur)

Possibilities of gas-phase radio-chromatography application to permanent-gas analysis; Possibilites de la radiochromatographie en phase gazeuse applications a l'analyse des gaz permanents

Energy Technology Data Exchange (ETDEWEB)

Dupuis, M.C.; Charrier, G.; Alba, C.; Massimino, D. [Commissariat a l' Energie Atomique, Bruyeres-le-Chatel (France). Centre d' Etudes

1970-07-01

The gas-phase radio-chromatography technique has been applied to the rapid analysis of permanent gases (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) labelled with radioactive indicators ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). After calibration, the components of such a mixture can be identified and their concentrations measured in less than two hours, using a sample volume of from 0.1 to 10 cm{sup 3}. The minimum detectable activity is of the order of 10{sup -4} {mu}C for each radioactive isotope. The measurements are reproducible to about 2 to 3 per cent. This work has been mainly concerned with the influence of parameters affecting the response of the radioactivity detector (ionization chamber or gas flow proportional counter). The method has very numerous applications both theoretically, for the study of chromatographic phenomena under ideal conditions (infinitesimal concentrations made possible by the use of radioactive tracers), and practically, for rapid and accurate radiochemical analysis of radioactive gas mixtures. (authors) [French] La technique de radiochromatographie en phase gazeuse est appliquee a l'analyse rapide de gaz permanents (H{sub 2}, O{sub 2}, N{sub 2}, A, Kr, Xe, CO, CH{sub 4}) marques par des indicateurs radioactifs ({sup 3}H, {sup 37}A, {sup 85}Kr, {sup 133}Xe). Apres etalonnage, l'identification et la mesure des concentrations des constituants d'un tel melange requierent moins de deux heures, sur un volume d'echantillon de 0.1 a 10 cm{sup 3}. L'activite minimum detectable est de l'ordre de 10{sup -4} {mu}C pour chaque isotope radioactif. La reproductibilite des mesures est de l'ordre de 2 a 3 pour cent. L'etude porte principalement sur l'influence des parametres affectant la reponse du detecteur de radioactivite (chambre d'ionisation, ou compteur proportionnel a circulation). La methode est extremement fertile en applications tant sur le plan theorique pour l

Numerical simulations on the effect of aerosols on tropospheric chemistry and range of sight; Numerische Simulationen zur Wirkung des Aerosols auf die troposphaerische Chemie und die Sichtweite

Energy Technology Data Exchange (ETDEWEB)

Riemer, N.

2002-05-01

In this study the mesoscale KAMM/DRAS model system was extended by an MADE aerosol module with a view to studying tropospheric aerosols in terms of composition and size distribution in the greatest possible detail. In particular, the MADE aerosol module was supplemented by a routine for soot. This routine involves the parameterisation of the ageing process of soot through coagulation of soot particles with soluble particles and condensation of sulphuric acid on the soot particles. This transforms the soot from an external into an internal mixture and changes its hygroscopic properties. Thus extended the model system was used to study two aspects of the effects of aerosols on the physical and chemical environment of the troposphere. The first of these two tasks was to quantify the influence of heterogeneous hydrolysis of dinitrogen pentoxide (N{sub 2}O{sub 5}) on tropospheric chemistry under summer smog conditions. The second was to study the optical properties of aerosols. The paper shows a way of deriving extinction coefficients from the calculated aerosol distributions. This is then used as a starting point for developing a method for determining range of sight. [German] Das mesoskalige Modellsystem KAMM/DRAIS wird im Rahmen dieser Arbeit um das Aerosolmodul MADE erweitert, um das troposphaerische Aerosol sowohl bezueglich seiner Zusammensetzung als auch bezueglich seiner Groessenverteilung moeglichst detailliert zu behandeln. Insbesondere wird das Aerosolmodul MADE um die Behandlung der Substanz Russ ergaenzt. Hierbei wird der Alterungsprozess von Russ durch Koagulation der Russteilchen mit loeslichen Partikeln und durch Kondensation von Schwefelsaeure auf den Russpartikeln, wodurch der Russ von einer externen in eine interne Mischung uebergeht und seine hygroskopischen Eigenschaften aendert, parametrisiert. Mit dem so erweiterten Modellsystem wird fuer zwei Themenschwerpunkte die Wirkung des Aerosols auf die physikalischen und chemischen Bedingungen in der

Waste Disposal Research and Development in the United States of America; L'Elimination des Dechets Radioactifs aux Etats-Unis d'Amerique: Travaux de Recherche et Progres Accomplis; 0418 0417 0423 0427 0414 ; Investigaciones y Trabajos Realizados en los Estados Unidos en Materia de Evacuacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Struxness, E. G.; Cowser, K. E.; De Laguna, W.; Jacobs, D. G.; Morton, R. J.; Tamura, T. [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1960-07-01

A review of the waste-disposal research and development carried out in the United States of America is given. The major research effort concerns the conversion of high-level liquid wastes into solids. At Hanford and Oak Ridge low-level wastes are disposed to the ground in pits, cribs and lagoons. Geochemical studies related to waste disposal are conducted at Hanford, Oak Ridge and the University of North Carolina. Experiments with soil columns ate described ; these are more effective for the decontamination of waste streams than either cribs or pits. The most suitable exchange materials for the soil columns are found to be vermiculite supported by rock phosphate and the latter supported by graded gravel. The progress of research work on the possibility of injecting radioactive liquid wastes into porous formations through deep wells and disposing of radioactive wastes in impermeable formations by hydraulic fracturing is outlined. (author) [French] L'auteur passe en revue les recherches effectuees aux Etats-Unis en matiere d'elimination des dechets radioactifs et les progres accomplis dans ce domaine. En matiere de recherche, on s'attache principalement a la conversion en solides des dechets liquides de haute activite. A Hanford et a Oak Ridge, les dechets de faible activite sont elimines par decharge terrestre dans des coffres, puits et depots lagunaires. Des etudes de geochimie se rapportant a l'elimination des dechets sont en cours a Hanford, a Oak Ridge et l'Universite de Caroline du Nord. Le memoire decrit les experiences faites avec des colonnes ; pour decontaminer les dechets liquides, ces dernieres sont plus efficaces que les coffres ou les puits. Les substances echangeuses d'ions les plus appropriees pour les colonnes sont vermiculite-phosphate naturel-gravier trie. L'auteur expose les progres dea travaux de recherche portant sur la possibilite d'injecter des dechets radioactifs liquides dans des formations poreuses, par decharge dans des puits profonds, et

The conditioning of radioactive waste by bitumen; Conditionnement des dechets radioactifs par le bitume

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Scheidhauer, J; Malabre, M [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

1961-07-01

The separation of radioactive sludge and waste by bitumen is studied. Results are given concerning various trials carried out on the lixiviation of the final product by water as a function of the pH, of the time, and of the composition. The conditions for carrying out this process of coating the waste are controlled from a radioactive point of view. (author) [French] L'isolement de boues radioactives et de dechets par le bitume est etudie. Les resultats de divers essais portant sur la lixiviation par l'eau du produit fini en fonction du pH, du temps et de la composition sont exposes. Les conditions de realisation de l'enrobage sont controlees au point de vue du risque radioactif. (auteur)

Measurement of the wear rate of cast grinding balls using radioactive tracers; Evaluation de l'usure des boulets pour concasseurs, au moyen des indicateurs radioactifs; Izmerenie skorosti iznosa litykh drobil'nykh sharov pri pomoshchi mechenykh atomov; Medicion de la velocidad de desgaste de bolas trituradoras de acero colado con ayuda de indicadores radiactivos

Energy Technology Data Exchange (ETDEWEB)

Keys, J D; Eichholz, G G [Department of Mines and Technical Surveys, Ottawa, ON (Canada)

1962-01-15

The wear rate of grinding balls used in ball mills is usually hard to determine under operational conditions and little is known-about the factors determining ball life. Radioactive tracers have been used successfully to mark cast steel balls to obtain information on their life under various operating conditions for comparison with balls of different type or composition. A batch of marked steel balls has been followed through a milling operation over several weeks and statistics on wear and loss of weight have been obtained. In the test runs cobalt-60 was added to the molten metal before casting and the balls were then observed in use at an iron mine. The radioactive batch was added to a ball mill with a normal charge of about 75 tons and the mill charge was sampled at weekly intervals to pick out active balls. These balls were inspected and weighed, and the wear rate has been calculated. This procedure has proved to be a practical way of investigating wear properties under plant operating conditions. (author) [French] Il est en general difficile de determiner le taux d'usure des boulets de broyeurs dans des conditions normales d'utilisation et l'on ne sait pas grand-chose des facteurs qui determinent la longevite des boulets. Les auteurs ont employe avec succes des indicateurs radioactifs pour marquer des boulets d'acier moule, en vue d'obtenir des indications sur leur duree dans diverses conditions de. fonctionnement et de faire une comparaison entre des boulets de type different ou de. composition differente. Ils ont suivi un lot de boulets, d'acier ainsi marques pendant une operation de broyage qui a dirre plusieurs semaines, ce qui a permis de recueillir des donnees statistiques sur leur usure et leur perte de poids. Au cours des essais, du cobalt-60 a ete ajoute au metal fondu avant le moulage des boulets. Ceux-ci ont ete ensuite maintenus en observation pendant leur emploi dans une mine de fer et une mine d'or. Le lot radioactif a ete introduit danfe un

Disposal of the radioactive effluents at the 'Commissariat a l'Energie Atomique'. Treatment leading to evacuation into a river; Probleme du rejet des residus radioactifs liquides au CEA. Traitements aboutissant a des rejets en riviere

Energy Technology Data Exchange (ETDEWEB)

Duhamel,; Menoux,; Candillon, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

loaded water, 10) Impot elements other than Sr{sup 90} are also studied. (author) [French] Le probleme du traitement des residus radioactifs liquides au CEA est envisage sous l'angle du rejet ultime en riviere dans des conditions optima permettant de satisfaire aux Normes de la protection. 2) A Saclay, ou l'on ne dispose que d'un etang ou l'eau ne se renouvelle pas, les liquides epures sont envoyes par camion citerne a Fontenay-aux-Roses, ou ils sont deverses provisoirement - dans les egouts - en attendant qu'un point de rejet en Seine ait ete determine. 3) Au Bouchet, les eaux residuaires de l'Usine de traitement de minerais d'urano-thorianite devront etre traitees en deux temps de facon a separer le radium dans une premiere phase, ce qui facilitera l'epuration au cours de la deuxieme phase. 4) En vue des futurs rejets a Marcoule, une etude a ete conduite a Saclay, sur des effluents synthetiques - type Marcoule - ayant pour but de mettre au point des procedes d'elimination selective du Sr d'une part, du Cs d'autre part, par coprecipitation. 5) Dans le cas general du rejet ultime en riviere, les problemes suivants sont successivement envisages: - predilution entre les bassins de stockage des eaux epurees et le fleuve; - mode d'injection dans le fleuve; - dilution dans le fleuve (etude prealable par traceurs); - evolution de l'activite dans les eaux du fleuve (adsorption par les organismes inertes ou vivants, contamination des berges); - incidence sur le choix d'un site; - dilution isotopique. 6) Ce dernier probleme est specialement detaille. 7) La teneur de l'eau en un element donne conditionne la dilution isotopique de son isotope radioactif. L'analyse decelant une carence, il est possible d'y suppleer par des rejets d'isotope stable. 8) Cette methode conduit en certains cas a des analyses delicates (en particulier dans le cas du {sup 90}Sr), la teneur en isotope stable necessaire a une forte dilution isotopique restant faible (ce qui est d'ailleurs un avantage). 9

A contribution to the study of radioactive waste dilution in the Rhone involving tests with a rhodamine B tracer; Contribution a l'etude de la dilution des effluents radioactifs dans le Rhone par le rejet experimental de rhodamine B

Energy Technology Data Exchange (ETDEWEB)

Rodier, J.; Marichal, M. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre de production de plutonium de Marcoule, Service de protection contre les radiations (France)

1961-07-01

The process whereby waste from the Marcoule plant mixes with the water in the Rhone was followed in tests with rhodamine as a chemical tracer. Satisfactory dispersion was noted less than 4 km downstream from the waste discharge duct outlet, and the degree of homogeneity was considered to be satisfactory at the bridge of Roquemaure, und perfect at Avignon. This investigation not only revealed a complete absence of any preferential flow paths containing high radioactive waste concentrations, but it also enabled the most representative points to be selected at which to take Rhone water samples during future radioactive waste discharges. Reprint of a paper published in 'La Houille Blanche' N. 5 - Aug 196, p. 636-641 [French] L'emploi de la rhodamine comme traceur chimique a permis de suivre l'evolution du melange des effluents du Centre de Marcoule aux eaux du Rhone. La dispersion est deja satisfaisante a moins de 4 km en aval de la conduite des rejets, et l'homogeneite peut etre consideree comme atteinte au pont de Roquemaure et parfaite a Avignon. Cette etude a montre que les veines preferentielles ou se concentrait l'ecoulement des effluents radioactifs n'existent pas. Elle a permis de preciser en outre les emplacements les plus representatifs des points d'echantillonnage des eaux du Rhone au cours des rejets. Reproduction d'un article publie dans 'La houille blanche' N. 5 - Aug 196, p. 636-641.

A new class of medicament: radioactivity isotopes (1962); Une nouvelle classe de medicaments: les isotopes radioactifs (1962)

Energy Technology Data Exchange (ETDEWEB)

Cohen, Y. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

Very many radioelement are used in medicine, either for diagnosis or as therapeutics. The development of medicine has entailed an increase in the number of application of radioactive isotopes. Firstly used in the form of simple inorganic molecules for diagnosis or as anticancer therapeutics, radioelements are now used for labelling organic molecules, allowing functional specific studies of any kind of nature. Their production is made difficult by their radio-active properties. Their pharmaceutical properties, determined by tests and controls, depend either from radiochemistry and from medicine. The author reminds, in this report, the methods for the preparation and analysis, and set out the medical application. (author) [French] De tres nombreux radioelements trouvent une application en medecine humaine, soit dans le diagnostic, soit en therapeutique. L'evolution de la medecine entraine un accroissement du champ d'application des isotopes radioactifs. D'abord utilises sous forme de molecules minerales simples, pour les diagnostics ou des therapeutiques anticancereuses, les radioelements sont maintenant introduits dans des molecules organiques qui permettent des etudes fonctionnelles specifiques de toute nature. Leur fabrication est compliquee par leurs proprietes radioactives. Leurs caracteristiques pharmaceutiques determinees par des essais et controles, sont liees d'une part a la radiochimie, d'autre part a la medecine. L'auteur rappelle, dans cet expose, les methodes de preparation et d'analyse et aborde les applications medicales. (auteur)

A new class of medicament: radioactivity isotopes (1962); Une nouvelle classe de medicaments: les isotopes radioactifs (1962)

Energy Technology Data Exchange (ETDEWEB)

Cohen, Y [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

Very many radioelement are used in medicine, either for diagnosis or as therapeutics. The development of medicine has entailed an increase in the number of application of radioactive isotopes. Firstly used in the form of simple inorganic molecules for diagnosis or as anticancer therapeutics, radioelements are now used for labelling organic molecules, allowing functional specific studies of any kind of nature. Their production is made difficult by their radio-active properties. Their pharmaceutical properties, determined by tests and controls, depend either from radiochemistry and from medicine. The author reminds, in this report, the methods for the preparation and analysis, and set out the medical application. (author) [French] De tres nombreux radioelements trouvent une application en medecine humaine, soit dans le diagnostic, soit en therapeutique. L'evolution de la medecine entraine un accroissement du champ d'application des isotopes radioactifs. D'abord utilises sous forme de molecules minerales simples, pour les diagnostics ou des therapeutiques anticancereuses, les radioelements sont maintenant introduits dans des molecules organiques qui permettent des etudes fonctionnelles specifiques de toute nature. Leur fabrication est compliquee par leurs proprietes radioactives. Leurs caracteristiques pharmaceutiques determinees par des essais et controles, sont liees d'une part a la radiochimie, d'autre part a la medecine. L'auteur rappelle, dans cet expose, les methodes de preparation et d'analyse et aborde les applications medicales. (auteur)

Storage and Disposal of Solid Radioactive Waste; Stockage et Evacuation des Dechets Radioactifs Solides; 0425 0420 0414 ; Almacenamiento y Evacuacion de Desechos Radiactivos Solidos

Energy Technology Data Exchange (ETDEWEB)

Pomarola, J. [Chef du Bureau Technique, Service de Controle des Radiations et de Genie Radioactif, Commissariat a l' Energie Atomique, Saclay (France)

1960-07-01

This paper deals with solutions for the problem of final disposal of solid radioactive waste. I. It is first essential to organize a proper system of temporary storage. II. Final Storage In order to organize final storage, it is necessary to fix, according to the activity and form of the waste, the site and the modes of transport to be used within and outside the nuclear centre. The choice of solutions follows from the foregoing essentials. The paper then considers, in turn, final storage, on the ground, in the sub-soil and in the sea. Economic considerations are an important factor in determining the choice of solution. (author) [French] La presente communication a pour objet les solutions envisagees pour une destination finale des dechets radioactifs solides. I - Il est tout d'abord necessaire de prevoir un stockage provisoire organise. II - Stockage definitif: La realisation d'un stockage definitif rend necessaire, en fonction de l'activite et du conditionnement des dechets, la definition: - du site et des modes de transports envisages a l'interieur et a l'exterieur des Centres Nucleaires. Le choix des solutions decoule des imperatifs ci-dessus et on examine successivement le stockage definitif: - sur le sol, - dans le sous-sol, - en mer. Les considerations d'ordre economique constituent un facteur important dans le choix de la solution. (author) [Spanish] El autor de la memoria estudia las diferentes soluciones previstas para la evacuacion definitiva de los desechos radiactivos solidos. I - Antes que nada hay que preparar un almacenamiento provisional organizado. II - Evacuacion definitiva : Para organizar la evacuacion definitiva es necesario definir antes, en funcion de la actividad y acondicionamiento de los desechos: - el emplazamiento y la forma de transporte que se piensa utilizar en el interior y en el exterior de los centros nucleares. La eleccion de las diversas soluciones depende de las dos condiciones mencionadas; el autor examina sucesivamente la

Radioactive contamination of aquatic media and organisms; La contamination radioactive des milieux et des organismes aquatiques

Energy Technology Data Exchange (ETDEWEB)

Fontaine, Y [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author) [French] Apres une courte etude des dechets radioactifs produits par les utilisations pacifiques ou militaires de l'Industrie Atomique, l'auteur fait etat d'abord des observations effectuees 'sur le terrain' concernant l'extension de la contamination des organismes aquatiques en rapport avec celle du milieu. L'auteur analyse ensuite les etudes experimentales se rapportant aussi bien au metabolisme des radioisotopes qu'aux facteurs et aux modalites de la contamination des organismes aquatiques par les dechets de l'industrie atomique. Un projet de travail experimental precis est presente a la fin de cette revue qui comporte pres de 300 references bibliographiques. (auteur)

Physical metrology of aerosols; Metrologie physique des aerosols

Energy Technology Data Exchange (ETDEWEB)

Boulaud, D.; Vendel, J. [CEA Saclay, 91 - Gif-sur-Yvette (France). Inst. de Protection et de Surete Nucleaire

1996-12-31

The various detection and measuring methods for aerosols are presented, and their selection is related to aerosol characteristics (size range, concentration or mass range), thermo-hydraulic conditions (carrier fluid temperature, pressure and flow rate) and to the measuring system conditions (measuring frequency, data collection speed, cost...). Methods based on aerosol dynamic properties (inertial, diffusional and electrical methods) and aerosol optical properties (localized and integral methods) are described and their performances and applications are compared

Quantitative measurements of small isotopic samples in gaseous mixtures by utilization of some nuclear properties; Etude des possibilites de mesures de faibles quantites de gaz radioactifs dans un melange en utilisant simultanement plusieurs proprietes nucleaires

Energy Technology Data Exchange (ETDEWEB)

Maragnon, J; Delperie, C

1967-12-01

The question is to define the characteristics of a group of measurements allowing the analysis of traces of radioactive rare gases in gas mixtures of different composition. To distinguish the radioactive isotopes from each other and the activity level reaching 10{sup 6} due to their nuclear properties, the method was chosen to use several nuclear properties: gamma radiation energy, beta particle energy, lifetime of excited states. The choice of a plastic scintillator as beta detector allows to answer satisfactorilly to this demand by measurement of nuclear constants because of the short de/excitation time of this detector. Another advantage is that it can be a reservoir for the sample without any destruction nor modification of the sample. The study has been based on the mixture of Kr-85, the analysis of other rare gases follwos immediately from the adopted principle. [French] Les auteurs ont oriente leur recherche vers une solution permettant de distinguer les isotopes radioactifs les uns des autres et dans des rapports d'activite pouvant atteindre 10{sup 6}, grace a plusieurs de leurs proprietes nucleaires, energie de rayonnement gamma, energie de la particule beta, temps de vie des niveaux excites. Le choix d'un scintillateur plastique comme detecteur beta permet de repondre d'une maniere satisfaisante a la mesure des constantes nucleaires en raison du temps de de/excitation rapide de ce scintillateur. Il offre en outre l'avantage de pouvoir servir de reservoir a l'echantillon sans entrainer aucune destruction ni modification de celui-ci. L'etude a ete basee sur la mixture de Kr-85, l'analyse des autre gaz rares decoulant immediatement du principe adopte. (auteur)

Storage of plugs and experimental devices from reactors; Stockage des bouchons et dispositifs experimentaux en provenance des reacteurs (1961)

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Cerre, P; Mestre, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

- Within the general programme of storage and treatment of radioactive waste produced by the various operations carried out in an atomic center, it is useful to consider separately the problem of certain waste from reactors, which, because of its size and physical nature, has to be stored with a view to being later treated and finally evacuated. The solution which we propose for this storage problem is presented in this paper. (authors) [French] - Dans le cadre du stockage et du conditionnement des dechets radioactifs provenant des diverses manipulations effectuees dans un centre atomique, il y a lieu de considerer a part certains dechets des reacteurs qui, par leur dimension et leur nature physique doivent etre stockes en vue de leur reprise ulterieure pour un conditionnement et une evacuation definitifs. La solution que nous avons apportee a ce stockage fait l'objet de l'expose qui suit. (auteurs)

Disposal of the radioactive effluents at the 'Commissariat a l'Energie Atomique'. Treatment leading to evacuation into a river; Probleme du rejet des residus radioactifs liquides au CEA. Traitements aboutissant a des rejets en riviere

Energy Technology Data Exchange (ETDEWEB)

Duhamel; Menoux; Candillon [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

to find out in loaded water, 10) Impot elements other than Sr{sup 90} are also studied. (author) [French] Le probleme du traitement des residus radioactifs liquides au CEA est envisage sous l'angle du rejet ultime en riviere dans des conditions optima permettant de satisfaire aux Normes de la protection. 2) A Saclay, ou l'on ne dispose que d'un etang ou l'eau ne se renouvelle pas, les liquides epures sont envoyes par camion citerne a Fontenay-aux-Roses, ou ils sont deverses provisoirement - dans les egouts - en attendant qu'un point de rejet en Seine ait ete determine. 3) Au Bouchet, les eaux residuaires de l'Usine de traitement de minerais d'urano-thorianite devront etre traitees en deux temps de facon a separer le radium dans une premiere phase, ce qui facilitera l'epuration au cours de la deuxieme phase. 4) En vue des futurs rejets a Marcoule, une etude a ete conduite a Saclay, sur des effluents synthetiques - type Marcoule - ayant pour but de mettre au point des procedes d'elimination selective du Sr d'une part, du Cs d'autre part, par coprecipitation. 5) Dans le cas general du rejet ultime en riviere, les problemes suivants sont successivement envisages: - predilution entre les bassins de stockage des eaux epurees et le fleuve; - mode d'injection dans le fleuve; - dilution dans le fleuve (etude prealable par traceurs); - evolution de l'activite dans les eaux du fleuve (adsorption par les organismes inertes ou vivants, contamination des berges); - incidence sur le choix d'un site; - dilution isotopique. 6) Ce dernier probleme est specialement detaille. 7) La teneur de l'eau en un element donne conditionne la dilution isotopique de son isotope radioactif. L'analyse decelant une carence, il est possible d'y suppleer par des rejets d'isotope stable. 8) Cette methode conduit en certains cas a des analyses delicates (en particulier dans le cas du {sup 90}Sr), la teneur en isotope

Containment of Radioactive Waste for Sea Disposal and Fisheries Off the Canadian Pacific Coast; La Mise en Recipients des Dechets Radioactifs en Vue de leur Elimination dans la Mer et la Protection des Pecheries Operant au Large de la Cote Canadienne de l'Ocean Pacifique; 0423 0414 0414 ; Confinamiento de Desechos Radiactivos para su Evacuacion en el Mar, en Relacion con las Pesquerias de la Costa Canadiense del Pacifico

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Waldichuk, Michael [Fisheries Research Board of Canada Biological Station, Nanaimo, BC (Canada)

1960-07-01

Low-level radioactive waste consists largely of contaminated laboratory trash, larger items of equipment, animal carcasses from biological tracer experiments, active liquids, and some reactor-irradiated materials. A total of 16,288 55-gallon drums of low-level waste has been dumped off the coast of California from 1946 to 1957, inclusive. The major objectives of the criteria for US sea disposal operations have been (1) safety in handling between waste originator and disposal site, and (2) adequate sinking of wastes in the sea. There has been no requirement for integrity of container or contents at depth. Other techniques used or previously suggested for radioactive waste containment, such as canning, adsorption on clay, and integration into glass are described. In order to render a radioactive waste harmless to fish and other aquatic organisms, it must be either (1) isolated from the environment, or (2) dispersed to levels of permissible concentrations. A spherical vault of suitable engineering design, hermetically sealed and able to withstand high pressures, is proposed for low-level and intermediate-level solid waste disposal, as a means of isolating the waste from the environment. Fish may be affected by radioactive waste in their environment through: (1) direct radiation from the disposed radioactive material; (2) ingestion of food organisms containing concentrated radioisotopes; (3) irradiation by water containing radioactive ions or particles; and (4) contamination by bottom materials rich in precipitated radioisotopes. Research necessary before widespread marine disposal of radioactive waste should be permitted is suggested. (author) [French] Les dechets de faible radioactivite sont constitues surtout par des detritus contamines provenant des laboratoires, des accessoires d'assez grande dimension, des carcasses d'animaux ayant servi a des experiences biologiques avec traceurs, des liquides radioactifs et certains materiaux irradies provenant de reacteurs. De

The background aerosol in the lower stratosphere and the tropospheric aerosol in the Alps. Final report; Das Hintergrundaerosol der unteren Stratosphaere und das troposphaerische Aerosol der Alpen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Jaeger, H.; Trickl, T.

2001-06-04

As a contribution to the German Aerosol-Lidar Network lidar backscatter measurements have been carried out at Garmisch-Partenkirchen in a wide range of the atmosphere from next to the ground to altitudes beyond 30 km. The investigations, on one hand, were devoted to establishing a climatology of the aerosol extinction coefficient for the northern Alps and to prolonging the long-term measurement series of the stratospheric aerosol. On the other hand, aerosol was used as a tracer of polluted air masses in atmospheric transport studies (orographically induced vertical transport, advection of Saharan dust, as well as aerosol advection from the North american boundary layer and from large-scale wild fire in the United States and Canada). These transport processes given the seasonal cycle of the aerosol throughout the troposphere. In the free troposphere a pronounced spring-time aerosol maximum was found. The stratospheric aerosol concentration had decayed to a background-type level during the reporting period. As a consequence, the influence of smaller aerosol contributions could be distinguished such as the eruption of the volcano Shishaldin (Alaska) and aircraft emissions. (orig.) [German] Im Rahmen des deutschen Aerosollidarnetzes wurden in Garmisch-Partenkirchen Lidar-Rueckstreumessungen in einem weiten Bereich der Atmosphaere von Bodennaehe bis in ueber 30 km Hoehe durchgefuehrt. Die Arbeiten dienten zum einen der Erstellung einer Klimatologie des Aerosol-Extinktionskoeffizienten fuer die Nordalpen sowie der Verlaengerung der seit 1976 erstellten Langzeitmessreihe des stratosphaerischen Aerosols. Zum anderen fanden atmosphaerische Transportstudien statt, bei denen das Aerosol als 'Tracer' fuer Luftverschmutzung verwendet wurde (orographisch induzierter Vertikaltransport, Advektion von Saharastaub und Aerosoladvektion aus der nordamerikanischen Genzschicht und von grossflaechigen Waldbraenden in den U.S.A. und Kanada). Diese Transportprozesse bestimmen den

Radioactive contamination of aquatic media and organisms; La contamination radioactive des milieux et des organismes aquatiques

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Fontaine, Y. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

After a brief account of the radioactive wastes produced by peaceful or military uses of Atomic Industry, the author first describes a series of observations carried out 'in the field' on the extent of contamination in aquatic organisms with respect to that of the medium. The experimental studies are then analysed, with reference both to the radioisotope metabolism and to the factors and types of contamination of aquatic organisms by wastes from atomic industry. A precise experimental project is presented at the end of the paper, including almost 300 references. (author) [French] Apres une courte etude des dechets radioactifs produits par les utilisations pacifiques ou militaires de l'Industrie Atomique, l'auteur fait etat d'abord des observations effectuees 'sur le terrain' concernant l'extension de la contamination des organismes aquatiques en rapport avec celle du milieu. L'auteur analyse ensuite les etudes experimentales se rapportant aussi bien au metabolisme des radioisotopes qu'aux facteurs et aux modalites de la contamination des organismes aquatiques par les dechets de l'industrie atomique. Un projet de travail experimental precis est presente a la fin de cette revue qui comporte pres de 300 references bibliographiques. (auteur)

Aerosol vertical distribution, new particle formation, and jet aircraft particle emissions in the free troposhere and tropopause region; Vertikalverteilung und Neubildungsprozesse des Aerosols und partikelfoermige Flugzeugemissionen in der freien Troposphaere und Tropopausenregion

Energy Technology Data Exchange (ETDEWEB)

Schroeder, F P

2000-07-01

dokumentiert und kommentiert im Hinblick auf potentielle Klimawirksamkeit anthropogener Aerosoleintraege in die Atmopshaere. Der erste Teil beschreibt innovative Messtechnik zur raeumlich hochaufloesenden Messung von Kleinstaerosolen im Nanometerbereich auf Basis von Kondensationskernzaehlern (CNC), notwendige Voraussetzung zur Beobachtung von atmosphaerischen Nukleationsereignissen und Flugzeugemissionen. Der zweite Teil umfasst die phaenomenologische Dokumentation von Vertikalverteilung und Variabilitaet des Aerosols innerhalb der Troposphaere und Tropopausenregion. Typische mikrophysikalische Zustaende des Aerosols in mittleren und hohen Breiten der Nordhemisphaere werden in systematischen Messungen aus mehr als 60 Flugmissionen eingegrenzt. Einfache mathematische Parameterisierungen von Aerosolvertikal- und Groessenverteilungen werden entwickelt. Wichtige Aerosolquellen innerhalb der freien Troposphaere werden lokalisiert, moegliche Aerosolneubildungsmechanismen diskutiert. Der dritte Teil charakterisiert partikelfoermige Triebwerksemissionen in der oberen freien Troposphaere. Beschrieben wird ein erweitertes Experiment zur Messung extrem hoher Konzentrationen (>10{sup 6} cm{sup -3}) extrem kleiner Aerosole (bis <2 nm) im Abgasstrahl unterschiedlicher Passagierflugzeuge. Groessenverteilungen und Emissionsindizes werden abgeleitet. Von zentralem Interesse ist der Einfluss des Schwefelgehalts im Treibstoff auf Menge, Groesse und stoffliche Zusammensetzung der neugebildeten Aerosole. Verallgemeinerte Resultate aus drei Einzelexperimenten werden parameterisiert. (orig.)

Chemical composition and optical properties of aerosols in the lower mixed layer and the free troposphere. Final report of the AFS project; Chemische Zusammensetzung und optische Eigenschaften des Aerosols in der freien Troposphaere. Abschlussbericht zum AFS-Projekt

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Asseng, H. [Freie Univ. Berlin (Germany). Inst. fuer Weltraumwissenschaften]|[Max-Planck-Institut fuer Chemie, Mainz (Germany). Abt. Biogeochemie; Fischer, J. [Freie Univ. Berlin (Germany). Inst. fuer Weltraumwissenschaften; Helas, G. [Max-Planck-Institut fuer Chemie, Mainz (Germany). Abt. Biogeochemie; Weller, M. [Deutscher Wetterdienst, Potsdam (Germany). Meteorologisches Observatorium

2001-08-02

Aerosol radiative forcing is the largest unknown in current climate models and, as a result, in predicting future climate. Accurate vertically-resolved measurements of aerosol optical properties are an important element of improved climate prediction (IPCC). The present project has contributed to this objective. Jets of directly and remotely determined radiation data have been provided suitable to cut down the uncertainty of column- or layer related optical aerosol parameters. In the present case mean values and profiles of spectral scattering - and absorption coefficients have been retrieved from ground based and airborne sky-radiance/solar irradiance measurements. Available analyses of size and chemical composition of sampled particles (adjoined projects) have been also taken into consideration. The retrieved parameters have served as an input for modelling the radiative transfer exactly for the real time of measurements. Closure procedures yielded finally realistic spectral scattering - and absorption coefficients typically for the lower troposphere in a mostly rural Central European region. (orig.) [German] Die ungenuegende Kenntnis strahlungswirksamer, optischer Aerosolparameter ist laut IPCC die groesste Unbekannte bei der Modellierung des Klimas und seiner Veraenderung. Wissenschaft und Technik bemuehen sich in sog. Schliessungsexperimenten aus der Ueberbestimmung direkt und indirekt gemessener Aerosolparameter genaue(re) Kenntnis (Mittelwert/Variation) ueber deren Klimawirksamkeit zu erlangen. Im vorliegenden Projekt wurden aus verschiedenen passiven, spektralen Messungen von Streulicht und Transmission der Atmosphaere in verschiedenen Hoehen sowie aus der Beruecksichtigung von Partikelanalysen Dritter, Streu- und Absorptionskoeffizienten des Aerosols der gesamten Luftsaeule und in vertikaler Aufloesung abgeleitet. Strahlungstransportmodellierungen mit den gewonnenen Aerosolparametern als input engten ueber den Vergleich mit den Messungen deren Grad an

Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

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Fontaine, A; Berger, D [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1965-07-01

The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

Temperature Distribution in Radioactive Solid Wastes. Part I - Beta-Active Solids; Repartition des Temperatures dans les Dechets Radioactifs Solides. Partie I - Solides Radioactifs Beta; 0420 0410 0421 041f 0420 0415 0414 ; Distribucion de la Temperatura en los Desechos Radiactivos Solidos. Parte I - Desechos Solidos Emisores de Radiaciones Beta

Energy Technology Data Exchange (ETDEWEB)

Kotewale, D. A.; Ganguly, A. K. [Atomic Energy Establishment, Trombay (India)

1960-07-01

The paper deals with the calculations for temperature distribution over time in a radioactive sphere and in a finite radioactive cylinder buried in a medium having the same thermal properties. Formulae are given for such calculations. Numerical results on temperature build-up are presented graphically for the cases where the activity is due to beta-emitters such as P{sup 32}, Sr{sup 89}, Cs{sup 135} and Sr{sup 90} + (Y{sup 90}). General graphs for calculation of temperature build-up for any long-lived beta-emitter at certain points of interest in a sphere and in a cylinder of particular dimensions and diffusivity are presented. (author) [French] Ce memoire a trait aux calculs servant a evaluer la variation des temperatures en fonction du temps dans une sphere radioactive et dans un cylindre radioactif limite enfouis dans un milieue ayant les memes proprietes thermiques. Les formules utilisees dans ces calculs sont indiquees. Les resultats numeriques concernant la formation des temperatures sont representes graphiquement pour les cas ou l'activite est due a des emetteurs beta tels que {sup 32}P, {sup 89}Sr, {sup 135}Cs et {sup 90}Sr + ({sup 90}Y). Le memoire contient des abaques pour le calcul de la formation des temperatures dans les emetteurs gamma de longue periode a certains points interessants des spheres et des cylindres ayant des dimensions et une capacite de diffusion particulieres. (author) [Spanish] En la memoria se estudia el calculo de la distribucion de temperaturas en funcion del tiempo en una esfera radiactiva y en un cilindro radiactivo finito enterrados en un medio de identicas propiedades termicas. Se dan formulas para efectuar dicho calculo. En el caso en que la actividad se deba a emisores beta, tales como {sup 32}P, {sup 89}Sr, {sup 135}Cs y {sup 90}Sr + ({sup 90}Y), se representan graficamente los resultados numericos relativos al incremento de ]a temperatura. Asimismo, se proporcionan graficos generales para calcular el incremento de la

Health problems raised by the elimination of radioactive wastes and nuclear accidents; Problemes sanitaires poses par l'elimination des dechets radioactifs et par les accidents nucleaires

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Jammet, H; Mechali, D; Dousset, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

residus radioactifs produits par les installations nucleaires. L'evaluation du risque encouru par les populations et la fixation des limites admissibles pour les rejets ne peuvent resulter que d'une connaissance exacte du cheminement des radioelements rejetes, depuis leur source d'emission jusqu'a l'homme. L'incorporation des radioelements dans les chaines alimentaires constitue le premier risque a prendre en consideration. Les facteurs de passage doivent etre envisages, dans toutes les etapes de cette transmission, qu'elles interessent les milieux physiques ou les milieux proprement biologiques, du fait de leur continuite et de leur interdependance. Enfin, les donnees de caractere socio-economique et dietetique doivent etre recueillies pour conduire a une evaluation des risques et des niveaux admissibles reposant non sur des donnees theoriques mais sur des bases concretes et experimentales. Le risque d'accidents nucleaires dans l'industrie atomique, bien que de probabilite tres reduite, doit etre pris en consideration du fait de la gravite de leurs consequences. Les problemes sanitaires se posent d'une part dans le domaine de l'hygiene professionnelle, d'autre part dans celui de l'hygiene publique. Le premier domaine implique un risque double: d'irradiation et de contamination. Le domaine public n'est soumis essentiellement qu'au risque de contamination par les substances radioactives liberees accidentellement dans le milieu. Les etudes sanitaires a mener dans ce domaine comprennent, de ce fait, les recherches sur la therapeutique des irradiations ou des contaminations mais aussi celles relatives au transfert des radioelements depuis l'installation accidentee jusqu'a l'homme, principalement a travers les chaines alimentaires, dans leurs composantes physiques comme dans leurs composantes biologiques. De telles etudes sont a la base des decisions d'ordre sanitaire qu'il conviendrait de prendre dans le cas d'un accident. (auteurs)

Application of the chemical properties of ruthenium to decontamination processes; L'application des proprietes chimiques du ruthenium a des procedes de decontamination

Energy Technology Data Exchange (ETDEWEB)

Fontaine, A.; Berger, D. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1965-07-01

The chemical properties of ruthenium in the form of an aqueous solution of the nitrate and of organic tributylphosphate solution are reviewed. From this data, some known examples are given: they demonstrate the processes of separation or of elimination of ruthenium from radioactive waste. (authors) [French] Les proprietes chimiques du ruthenium en solutions aqueuses nitriques et en solutions organiques de tributylphosphate, sont passees en revue. A partir de ces donnees, quelques exemples connus sont cites: ils exposent des procedes de separation ou d'elimination du ruthenium de dechets radioactifs. (auteurs)

Recovery of sludge from the treatment of liquid radioactive effluents by co-precipitation with calcium carbonate: laboratory study; Recuperation des boues de traitement des effluents radioactifs liquides par coprecipitation avec le carbonate de calcium: etude de laboratoire

Energy Technology Data Exchange (ETDEWEB)

Patti, F.; Gailledreau, C.; Cohen, P.

1961-02-24

As during the treatment by co-precipitation with calcium carbonate of liquid radioactive residues, a partial decontamination can be obtained by simply agitating an already formed radioactive sludge with the effluent to be processed, the authors study whether it would be possible to first perform a co-precipitation with a lower dose of calcium carbonate and then to complete decontamination by agitating with an adequate quantity of sludge stored during preceding operations. The authors report the study of the influence of reactant quantity on the chemical treatment efficiency, of the evolution of the activity of a radioactive residual solution in contact with a precipitate, of the cleaner element, of a precipitate reuse, of the technological and economic aspects, and of another possibility of reduction of the precipitate volume [French] Dans le traitement par coprecipitation avec le carbonate de calcium des residus radioactifs liquides, une decontamination partielle peut etre obtenue en agitant simplement une boue radioactive deja formee avec l'effluent a traiter. En consequence, il pourrait etre possible d'effectuer d'abord une coprecipitation avec une dose plus faible de carbonate de calcium et de completer ensuite la decontamination en agitant le liquide avec une quantite convenable de boue stockee a partir d'operations precedentes. (auteurs)

On the Waste Disposal Potentiality of the Atmosphere; Possibilites d'Elimination des Dechets Radioactifs dans l'Atmosphere; 041a 0412 041e 041f 0414 ; Sobre la Posibilidad de Evacuar Desechos en la Atmosfera

Energy Technology Data Exchange (ETDEWEB)

Small, S. H.; Storebo, P. B. [Norwegian Defence Research Establishment (Norway)

1960-07-01

The whole scale of atmospheric mixing, transport and removal processes is reviewed. Certain measurements indicate replacement of stratospheric air within about two years, making high-altitude disposal of radioactive waste materials even less attractive than earlier assumed. Deposition of radioactive materials is to some extent systematically non-uniform, and permissible levels of atmospheric radioactivity should be based upon the probable hazards in the most exposed regions, e.g. regions of considerable orographic precipitation. In connexion with the measurement of atmospheric radioactivity, it is pointed out that sampling techniques should cover the probable effects of gradual changes in particle sizes, and removal of particles by settling, impingement and absorption on vegetation and buildings etc. Meteorological problems in connexion with radiation monitoring and warning systems are discussed in relation to reactor operations. Technical details of relatively simple warning systems are given. (author) [French] Les auteurs examinent l'ensemble des processus suivant lesquels les dechets radioactifs sont brasses, transportes et disperses dans les couches atmospheriques. Certaines mesures indiquent que le renouvellement des masses d'air stratospheriques se fait' en moins de deux ans environ; la possibilite d'eliminer les dechets radioactifs dans les couches superieures de l'atmosphere semble donc encore moins seduisante qu'elle ne le paraissait tout d'abord. On peut dire que, dans une certaine mesure, le depot des substances radioactives s'effectue systematiquement de facon non uniforme; pour determiner le taux de radioactivite atmospherique admissible, il faut donc se baser sur les risques probables encourus dans les regions les plus exposees, par exemple dans les regions a fortes precipitations orographiques. En ce qui concerne la mesure de la radioactivite atmospherique, les techniques d'echantillonnage devraient tenir compte des consequences probables de la

Sorption Regularities in Behaviour of Fission-Product Elements during Filtration of their Solutions through Ground; Lois de l'Absorption des Elements Radioactifs Lors du Filtrage des Solutions a Travers les Terrains; 0417 0410 041a 041e 041d 0414 ; Leyes de la Absorcion de los Elementos Radiactivos Cuando se Filtran Soluciones a Traves de las Formaciones Geologicas

Energy Technology Data Exchange (ETDEWEB)

Spitsyn, V. I.; Balukova, V. D.; Gromov, V. V.; Zakharov, S. I.; Zhagin, B. P.; Spiridonov, F. M.

1960-07-01

Research on the sorption of radioisotopes under natural conditions employing the controlled filtration process was performed. Radioisotopes were introduced into the solution as soon as filtration had become steady and the process continued for four months. Soil samples were then taken by drilling at different depths and analysed to determine their radioisotope content. Diffusion of radioisotopes was observed at depths of up to 10 m; two distinct boundaries of soil-activity decrease were ascertained: at the surface of the site and at the depth of the solution filtration front. In addition, the radiostrontium absorption by natural sorbents, principally pure minerals widely distributed in soils and subsoils, was investigated separately. The presence of calcium ions, even in small quantities, sharply reduces the degree of radiostrontium sorption. However, other conditions being equal, strontium may be absorbed to a greater extent than calcium, according to the composition of the sorbent. The field investigations of radiostrontium sorption and migration showed that when filtering radioactive solutions two possible variants have to be taken into account. In the first case the solutions are discharged into soil unaffected by any flow of ground water. In this situation the radiostrontium is retained by the soil. In the second case, the radioisotopes proceed directly into the water-bearing horizon. The radiostrontium will then migrate with the ground water flow and through the soil and this migration will be further affected by the sorption and desorption processes occurring. The experiments performed demonstrate the ease with which long-lived radioisotopes migrate under natural conditions and call attention to the need for thorough study of ground water problems in connexion with various methods of disposing of radioactive waste into ground. (author) [French] En declenchant un processus de filtration, il a ete possible d'etudier l'absorption des elements radioactifs dans

Health problems raised by the elimination of radioactive wastes and nuclear accidents; Problemes sanitaires poses par l'elimination des dechets radioactifs et par les accidents nucleaires

Energy Technology Data Exchange (ETDEWEB)

Jammet, H.; Mechali, D.; Dousset, M. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

residus radioactifs produits par les installations nucleaires. L'evaluation du risque encouru par les populations et la fixation des limites admissibles pour les rejets ne peuvent resulter que d'une connaissance exacte du cheminement des radioelements rejetes, depuis leur source d'emission jusqu'a l'homme. L'incorporation des radioelements dans les chaines alimentaires constitue le premier risque a prendre en consideration. Les facteurs de passage doivent etre envisages, dans toutes les etapes de cette transmission, qu'elles interessent les milieux physiques ou les milieux proprement biologiques, du fait de leur continuite et de leur interdependance. Enfin, les donnees de caractere socio-economique et dietetique doivent etre recueillies pour conduire a une evaluation des risques et des niveaux admissibles reposant non sur des donnees theoriques mais sur des bases concretes et experimentales. Le risque d'accidents nucleaires dans l'industrie atomique, bien que de probabilite tres reduite, doit etre pris en consideration du fait de la gravite de leurs consequences. Les problemes sanitaires se posent d'une part dans le domaine de l'hygiene professionnelle, d'autre part dans celui de l'hygiene publique. Le premier domaine implique un risque double: d'irradiation et de contamination. Le domaine public n'est soumis essentiellement qu'au risque de contamination par les substances radioactives liberees accidentellement dans le milieu. Les etudes sanitaires a mener dans ce domaine comprennent, de ce fait, les recherches sur la therapeutique des irradiations ou des contaminations mais aussi celles relatives au transfert des radioelements depuis l'installation accidentee jusqu'a l'homme, principalement a travers les chaines alimentaires, dans leurs composantes physiques comme dans leurs composantes biologiques. De telles etudes sont a la base des decisions d'ordre sanitaire qu

Aerosols produced by evaporation of a uranium wire; Aerosols produits par evaporation d'un fil d'uranium

Energy Technology Data Exchange (ETDEWEB)

Morel, C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1968-03-01

This work is devoted to the study of the aerosols formed when an uranium wire is evaporated in a normal or rarefied atmosphere, either with or without a drying agent. The heating of the wire can be either fast or slow. The first part is a study of aerosol production apparatus and of methods of measuring the aerosol. The second part presents the results obtained with various aerosols: the particles produced by the wire are less than one micron; during rapid heating, the granulometric distribution of the aerosol obeys a log-normal law; during slow heating, the distribution has two modes: one near 0.05 micron, the other close to 0.01 micron. (author) [French] Ce travail est consacre a l'etude des aerosols formes lors de l'evaporation d un fil d'uranium en atmosphere normale ou rarefiee en presence ou non de dessechant. Le chauffage du fil peut etre rapide ou lent. La premiere partie est une etude des appareils de production et des methodes de mesures de l'aerosol. La seconde partie consigne les resultats obtenus sur les differents aerosols: les particules emises par le fil sont inferieures au micron; lors d'un chauffage rapide, la repartition granulometrique de l'aerosol suit une loi log-normale; lors d un chauffage lent, la repartition presente deux modes: l'un voisin de 0.05 micron, l'autre voisin de 0.01 micron. (auteur)

Comparison of methods for measuring the ion exchange capacity of a soil. Development of a quick method; Comparaison des methodes de mesure de la capacite d'echange d'ions d'un sol. Mise au point d'une methode rapide

Energy Technology Data Exchange (ETDEWEB)

Amavis, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

In the course of a study on the movement of radioactive ions in soil we had to measure the cationic exchange capacity of various soil samples, this parameter being one of the most important in the appreciation of the extent of fixation of radioactive ions in the ground. The object of this report is to describe the various methods used and to compare the results obtained. A colorimetric method, using Co(NH{sub 3}){sub 6}{sup 3+} as exchangeable ion, was developed. It gives results comparable to those obtained with conventional methods, whilst considerably reducing the time necessary for the operations. (author) [French] A l'occasion de l'etude du mouvement des ions radio-actifs dans un sol, nous avons ete amenes a mesurer la capacite d'echange cationique de differents echantillons de sols; ce parametre etant un des plus importants pour apprecier la valeur de la fixation des ions radioactifs dans un terrain. L'objet de ce rapport est d'exposer les diverses methodes utilisees et de comparer les resultats obtenus. Une methode calorimetrique, utilisant Co(NH{sub 3}){sub 6}{sup 3+} comme ion echangeable, a ete mise au point: elle donne des resultats comparables a ceux obtenus avec les methodes habituelles et permet de reduire considerablement la duree des manipulations. (auteur)

Control panel for radiation around reactors (1963); Tableaux de controle des radiations aupres des piles (1963)

Energy Technology Data Exchange (ETDEWEB)

Candes, P; Barthoux, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

This report outlines the general philosophy of radiation control in French reactors and their annexes. The supervision is carried out continuously from a central control panel on which appear all the measurements made and the alarm signals. The equipment is described; one item makes it possible to measure simultaneously the radioactive dusts and gases. The specifications of the alarm system, which is considered to be the most important are given. Finally a new measuring technique is proposed which makes it possible to reduce considerably the cost of radiation control while at the same time providing the results in a form in which they can be easily treated, in particular in the case of the calculation of total doses. (authors) [French] Ce rapport definit la philosophie generale du controle des radiations dans les piles francaises et dans leurs annexes. La surveillance se fait d'une maniere continue a partir d'un tableau de controle centralise ou sont reportees toutes les mesures et les signalisations d'alarme. On decrit les appareils utilises, dont un permet la mesure simultanee des poussieres et gaz radioactifs, et on definit les specifications de la fonction alarme qui est consideree comme la plus importante. Enfin on propose une nouvelle technique de mesure qui permettrait de reduire considerablement le cout du controle des radiations tout en fournissant des resultats plus facilement exploitables, en particulier pour le calcul des doses integrees. (auteurs)

Analytical chemistry equipment for radioactive products; Installation de chimie analytique pour produits radioactifs

Energy Technology Data Exchange (ETDEWEB)

Douis, M; Guillon, A; Laurent, H; Sauvagnac, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-01

The report deals with a shielded enclosure, hermetic, for analytical examination and handling of radioactive products. Remote handling for the following is provided: pipette absorption - weighing - centrifuging - desiccation - volumetric - pH measurement - potentiometric - colorimetric - polarographic. The above list is not restrictive: the enclosure is designed for the rapid installation of other equipment. Powerfully ventilated and screened to 400 m-curies long life fission product levels by 5 cm of lead, the enclosure is fully safe to the stated level. (author) [French] La presente communication decrit une enceinte etanche et blindee permettant un travail et un controle analytique sur des produits radioactifs. Les techniques suivantes sont adaptees pour une manipulation a distance: pipettage, pesees, centrifugation, dessiccation, volumetrie, mesure de pH, potentiometrie, colorimetrie, polarographie. Cette liste n'est pas limitative. La conception de l'installation permet la mise en place rapide d'autres appareils. Protegee par 5 cm de plomb et fortement ventilee, elle donne toute securite de manipulation jusqu'a un niveau d'activite 400 mcuries en produits de fission a vie longue. (auteur)

Territory of Upper Volta. Interest and Programme of Prospecting for Radioactive Metals; Territoire de la Haute-Volta. Interet et Programme d'une Prospection pour Metaux Radioactifs

Energy Technology Data Exchange (ETDEWEB)

NONE

1958-04-15

The costs of a programme for prospecting for radioactive metals (esp. Uranium) can amount to a total cost of the order of 600 to 700 millions FF over 10 years. Such a programme represents a rather high risk, because in order to succeed, a reserve capable to pay for the programme must be found in the foreseen period. The first part of the report describes the Uranium reserves already known in Africa. [French] Un programme de prospection pour metaux radioactifs (notamment l'Uranium) pourrait etaler des depenses totales de l'ordre de 600 a 700 millions FF sur 10 ans. Un tel programme represente un risque assez grand, puisque pour reussir, il faut trouver dans le delai envisage, et avec les moyens prevus, un gisement capable d'amortir une telle depense. Une premiere partie du rapport expose les caracteres des gisments d'Uranium actuellement connus en Afrique.

Disposal of Radioactive Wastes in Natural Salt; Elimination des Dechets Radioactifs dans le Sel Naturel; 0423 0414 ; Evacuacion de Desechos Radiactivos en Formaciones Salinas Naturales

Energy Technology Data Exchange (ETDEWEB)

Parker, F. L.; Boegly, W. J.; Bradshaw, R. L.; Empson, F. M.; Hemphill, L.; Struxness, E. G.; Tamura, T. [Health Physics Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1960-07-01

The proposed use of cavities in salt formations as a disposal site for radioactive wastes is based upon : 1. Existence of salt for geologic time periods, 2. The impermeability of salt to the passage of water; 3. The widespread geographical distribution of salt; 4. The extremely large quantities of salt available; 5. The structural strength of salt; 6. The relatively high thermal conductivity of salt in comparison with other general geologic formations; 7. The possible recovery of valuable fission products in the wastes injected into the salt; 8. The relative ease of forming cavities in salt by mining, and the even greater ease and low cost of developing solution cavities in salt; and 9. The low seismicity in the areas of major salt deposits. Radioactive liquid wastes can be stored in cavities in natural salt formations if the structural properties of the salt are not adversely affected by chemical interaction, pressure, temperature, and radiation. Analytical studies show that it is possible to-store 2-year-old 10,000 MWD/T, 800 gal/ton waste in a sphere of 10 ft diameter without exceeding a temperature of 200 Degree-Sign F. Laboratory tests show that the structural properties and thermal conductivity of rock salt are not greatly altered by high radiation doses, although high temperatures increase the creep rate for both irradiated and unirradiated samples. Chemical interaction of liquid wastes with salt produces chlorine and other chlorine compound gases, but the volumes are not excessive. The migration of nuclides through the salt and deformation of the cavity and chamber can only be studied in undisturbed salt in situ. One-fifth-scale models have been run in a bedded salt deposit in Hutchinson, Kansas, and full-scale field tests are in progress. (author) [French] L'emploi envisage des cavites des gisements de sel comme lieu d'evacuation des dechets radioactifs se-fonde sur les considerations suivantes: 1. L'existence du sel dans des formations correspondant a

Review of the incineration of 500 tonnes of radio-active residues; Bilan de l'incineration de 500 tonnes de residus radioactifs

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Seyfried, P; Charbonneaux, M [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

1969-07-01

During its first five years operation, the incinerator at the Marcoule Centre has burnt almost 500 tonnes of radio-active residues. Improvements in some of the details of the process have been made during this period; they concern the nature of the materials involved. The technical and radiological results for the installation are very favorable, and have made it possible to maintain a high charge factor.Although the overall economic results are not advantageous in the case of ungraded solid residues this method represents nevertheless the best available for eliminating oils, solvents, wood and dead animals. It can also be of use furthermore each time that a dilution in the atmosphere can advantageously be used as a method of disposing of certain radio elements such as tritium or carbon 14 in the form of gases or vapours. (author) [French] L'incinerateur du Centre de Marcoule a brule, durant les 5 premieres annees de fonctionnement, pres de 500 tonnes de residus radioactifs. Les ameliorations de detail realisees au cours de cette periode ont porte sur la nature des materiaux employes. Les bilans techniques et radiologiques de l'installation sont tres favorables et ont permis de maintenir un facteur de charge eleve. Si le bilan economique n'est pas favorable a l'incineration des residus solides 'tout venant' cette methode constitue cependant la solution ideale pour l'elimination des huiles, des solvants, du bois et des cadavres d'animaux. En outre, elle peut etre interessante chaque fois que la dilution dans l'atmosphere peut etre avantageusement mise a profit pour rejeter certains radioelements tels que le tritium ou le carbone 14 sous forme de gaz ou de vapeurs. (auteur)

Applicability of ICRP principles for safety analysis of radioactive waste geological storage; Etude de l'applicabilite des principes de la CIPR a l'analyse de surete du stockage geologique des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

Lombard, J; Hubert, P; Pages, P

1987-07-01

Since the beginning of the eighties, the international organisations have established new recommendations for radioactive waste management. These recommendations are based on two principles. First is concerned with limitation of risks. It should be shown that the risk is smaller than the limit of acceptance. Practically only on risk criterion is foreseen. The principle demands, if a storage causes an event of individual risk (defined as a product of probability of occurrence and the probability of its causing severe health effects) is higher than 10 {sup -5} per year, this storage is not acceptable. The second principle deals with optimisation, demands that the level of protection related to the storage should be determined by a comparative process choosing the best compromise between the price of protection and the residual risk. These recommendations, especially the second one, differ from the safety analysis principles adopted presently in France and other countries. This study analyzes the advantages and potential inconveniences related to the introduction of the second principle. (author) [French] Depuis le debut des annees quatre vingt, de nouvelles recommandations ont ete formulees par les organismes internationaux (AIEA, OCDE, OIPR) en matiere de gestion des dechets radioactifs. Ces recommandations s'articulent autour de deux principes. Le premier, est celui de limitation des risques. II s'agit de demontrer que le risque est inferieur a un seuil d'acceptabilite. En pratique, un seul critere de risque est envisage. Ainsi le principe stipule, que si un stockage est a I'origine d'evenements conduisant a un risque individuel (defini comme le produit de a probabilite d'occurrence de l'evenement par Ia probabilite que cet evenement cause un effet sanitaire grave) total annuel superieur a 10{sup -5}/an, alors le risque lie a ce stockage est juge inacceptable. Le second, dit d'optimisation, stipule que le niveau de protection associe a un stockage (donc les

Fisheries Radiobiology and the Discharge of Radioactive Wastes; Radiobiologie des Pecheries et Evacuation des Dechets Radioactifs; 041f 0420 0418 014 ; Radiobiologia de las Pesquerias y Evacuacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Morgan, F. [Fisheries Radiobiological Laboratory, Ministry of Agriculture, Fisheries and Food (United Kingdom)

1960-07-01

In the United Kingdom authorizations to discharge radioactive wastes are granted by the Minister of Housing and Local Government, the Minister of Agriculture, Fisheries and Food, and by the Secretary of State for Scotland. The hazards arising from contamination of aquatic animals and plants concern the Department of Fisheries ; before authorizations to discharge liquid wastes have been given, the Department has made independent forecasts of permissible levels of discharge based on extensive studies carried out in its research vessels and radiobiological laboratory: for example, where fish have been affected this has meant studies of fish populations and fish migration: uptake of radioactivity by fish : public consumption of fish : commercial distribution of affected fish: L.D.{sub 50}: effects of radiation on tissue, etc. In the course of such work there has been close consultation with the Atomic Energy Authority, and agreement with the Atomic Energy Authority about the safety factor to be incorporated during the first two years of discharge. During these two years, monitoring data collected by the Atomic Energy Authority and the Ministry of Agriculture, Fisheries and Food enable checks and revisions of the original estimates to be made, and at the end of that time formal authorizations, based on operating experience, are issued. (author) [French] Au Royaume-Uni, les autorisations d'evacuer des dechets radioactifs sont accordees par le Ministre du logement et de l'administration locale, par le Ministre de l'agriculture, des pecheries et de l'alimentation et par le Secretaire d'Etat pour l'Ecosse. Les risques dus a la contamination des animaux et des plantes aquatiques relevent du Departement des pecheries; avant d'accorder des autorisations d'evacuer des dechets liquides, le Departement a evalue lui-meme les quantites dont l'evacuation pourrait etre admise, en se fondant sur des etudes approfondies qui sont faites dans ses bateaux de recherche et son laboratoire

The health physics of installations for decladding irradiated fuels or for handling radio-elements at Marcoule; La radioprotection des installations de degainage des combustibles irradies et des radio-elements a Marcoule

Energy Technology Data Exchange (ETDEWEB)

Chassany, J; Guillermin, P; Mallet, P [Commissariat a l' Energie Atomique, Centre de Production de Plutonium de Marcoule, 30 - Chusclan (France)

1966-07-01

Radiation protection practices for handling reactor fuel elements are described. Elements of considerable specific radioactivity are handled under water. A study was made of water filtration and of ventilation in the building. The installations are divided up into zones depending on the radioactive risks, and the radiation level atmospheric contamination are the object of a systematic control at various points. A description is given of all aspects of health physics which have been encountered during six years: storage, transfer of radioactive material; decladding, rolling, waste disposal, specialized operations, installations in operation and at rest, and transport. In spite of the gradual increase in the activity of these installations, the total doses received by the personnel have hardly altered and the number of cases of physical contamination has diminished. (authors) [French] Dans ces installations, se manipulent sous l'eau des elements a radioactivite specifique considerable. La filtration de l'eau, la ventilation ont ete particulierement etudiees. L'ensemble a ete divise en lieux classes en fonction des risques radioactifs et des appareils controlent en permanence l'irradiation et la contamination atmospherique en certains points. Tous les aspects de la radioprotection resultant de six annees d'experience relatifs: au stockage, au deconteneurage, au degainage, au laminage, a l'evacuation des residus, aux travaux particuliers, installations en marche et a l'arret, et aux transports sont successivement decrits. Malgre l'accroissement progressif de l'activite de cet ensemble, les doses integrees par le personnel n'ont pratiquement pas augmente et le nombre des cas de contamination corporelle a diminue. (auteurs)

The use radioactive tracers in the study of solid transport in water streams; Emploi de traceurs radioactifs pour l'etude du transport solide dans les cours d'eau

Energy Technology Data Exchange (ETDEWEB)

Courtois, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires; Jaffry, P; Heuzel, M [Laboratoire National d' Hydraulique de Chatou, 78 (France)

1960-07-01

The Laboratoire National d'Hydraulique which has been studying, during the last few years in conjunction with the Centre d'Etudes Nucleaires at Saclay, the development of apparatus and of methods of investigation of sediment transport by radioactive tracer techniques, is at the moment trying to perfect a genuinely quantitative method of investigation. Two experiments have recently been carried out in rivers, the first designed to investigate the transport of pebbles in the river Rhone, the other to investigate the movement of sands in the Niger. This second experiment has been supported by parallel experiments carried out on a reduced scale model of the Niger built at the laboratories of Chatou: in this experiment are used the radiation from {sup 56}Mn and {sup 24}Na obtained by direct activation of the crushed apricot store which represents, in the scale model, the natural sediment on the bed of the Niger. The combined efforts of the laboratories of Chatou and of the Centre d'Etudes Nucleaires at Saclay are at the moment directed to the application of radioactive tracers to studies on the scale models with the double aim: a) of having a single investigational method for the actual experiment and for the model making it possible to control the accuracy of the model in the preliminary stage of calibrating this model; b) of making the most of the possibilities of observation and of direct measurement offered by the scale models for studying the possibility of improving the tracer method, in particular with respect to the collecting of quantitative data. (author) [French] La Laboratoire National d'Hydraulique qui, depuis quelques annees a developpe, en collaboration avec le Centre d'Etudes Nucleaires de Saclay, les appareillages et les techniques d'etudes des mouvements de sediments par la methode des traceurs radioactifs, s'efforce actuellement de mettre au point un moyen d'investigation veritablement quantitatif. Deux experiences ont ete effectuees recemment en

Disposal of Radioactive Waste in the Subsurface of the Federal Republic of Germany: Geological and Hydro-Geological Problems; Elimination des Dechets Radioactifs dans le Sous-Sol de la Republique Federale d'Allemagne: Problemes Geologiques et Hydrogeologiques; 041f 041e 0414 ; Evacuacion de Desechos Radiactivos en el Subsuelo de la Republica Federal de Alemania Problemas Geologicos e Hidrogeologicos

Energy Technology Data Exchange (ETDEWEB)

Wagner, R.; Richter, W. [Bundesanstalt fuer Bodenforschung, Hannover (Germany)

1960-07-01

The geological and hydrogeological problems related to the subsurface disposal of radioactive wastes in the Federal Republic of Germany are outlined. Special consideration is given to the possibility of storing solid and liquid wastes in the salt-domes widespread in the north-west, and of injecting liquid waste into deep reservoirs containing briny water and located in favourable geologic structures. (author) [French] Les auteurs decrivent les problemes geologiques et hydrogeologiques que pose, dans la Republique federale d'Allemagne, l'elimination des dechets radioactifs dans le sous-sol. Ils examinent notamment la possibilite d'emmagasiner des dechets solides et liquides dans les salines, qui abondent dans la partie nord-ouest et d'injecter des dechets liquides dans de profonds reservoirs d'eau saline, situes dans des formations geologiques presentant des conditions favorables. (author) [Spanish] Los autores exponen los problemas geologicos e hidrogeologicos que plantea la evacuacion de desechos radiactivos en el subsuelo de la Republica Federal de Alemania. Examinan sobre todo la posibilidad de almacenar desechos solidos y liquidos en los domos de sal, muy abundantes en el noroeste del pais, y de inyectar desechos liquidos en depositos profundos de agua salobre situados en estructuras geologicas que presentan condiciones favorables. (author) [Russian] Privoditsja opisanie geologicheskih i gidrogeologicheskih problem, svjazannyh s podzemnym udaleniem radioaktivnyh othodov v Federal'noj Respublike Germanii. Osoboe vnimanie udeljaetsja vozmozhnosti skladirovanija tverdyh i zhidkih othodov v soljanyh kupolah, imejushhihsja v bol'shom kolichestve v severo- zapadnoj chasti Germanii, i zahoronenija zhidkih othodov v glubokie rezervuary, soderzhashhie solenye vody i raspolozhennye v podhodjashhih geologicheskih strukturah. (author)

Méthodologie d’analyse des signaux et caractérisation hydrogéologique : application aux chroniques de données obtenues aux laboratoires souterrains du Mont Terri, Tournemire et Meuse/Haute-Marne

OpenAIRE

Fatmi, Hassane

2009-01-01

Ce rapport présente des méthodes de prétraitement, d'analyse statistique et d'interprétation de chroniques hydrogéologiques de massifs peu perméables (argilites) dans le cadre d'études sur le stockage profond de déchets radioactifs. Les séries temporelles analysées sont la pression interstitielle et la pression atmosphérique, en relation avec différents phénomènes (marées terrestres, effet barométrique, évolution de l'excavation des galeries). Les pré-traitements permetten...

Half-life distribution table of radioactive nuclei; Table de distribution des periodes des noyaux radioactifs

Energy Technology Data Exchange (ETDEWEB)

Gugenberger, P [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1954-07-01

This table allows to identify an element if its period is known. Data for this table were taken from the half-life values adopted by Hollander, PERLMAN and SEABORG (Rev. mod. Phys., 1953, 22 number 2). Moreover for each nucleus, the mass number, the charge number and the type of decay are given in the table. (author) [French] Cette table permet l'identification d'un element dont la periode est connue. Elle a ete etablie en utilisant les valeurs des periodes donnees par HOLLANDER, PERLMAN et SEABORG dans Rev. mod. Phys., 1953, 25 numero 2. On y trouve en outre, pour chaque nuclide, les caracteristiques suivantes: Z, A, modes de desintegration. (auteur)

Half-life distribution table of radioactive nuclei; Table de distribution des periodes des noyaux radioactifs

Energy Technology Data Exchange (ETDEWEB)

Gugenberger, P. [Commissariat a l' Energie Atomique, Saclay(France). Centre d' Etudes Nucleaires

1954-07-01

This table allows to identify an element if its period is known. Data for this table were taken from the half-life values adopted by Hollander, PERLMAN and SEABORG (Rev. mod. Phys., 1953, 22 number 2). Moreover for each nucleus, the mass number, the charge number and the type of decay are given in the table. (author) [French] Cette table permet l'identification d'un element dont la periode est connue. Elle a ete etablie en utilisant les valeurs des periodes donnees par HOLLANDER, PERLMAN et SEABORG dans Rev. mod. Phys., 1953, 25 numero 2. On y trouve en outre, pour chaque nuclide, les caracteristiques suivantes: Z, A, modes de desintegration. (auteur)

Pharmacological study of radioactive-gold colloid transport by blood and by serous exudate; Contribution a l'etude pharmacologique du transport des colloides d'or radioactif par le sang et les exsudats sereux

Energy Technology Data Exchange (ETDEWEB)

Rousselet, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

transport de l'or colloidal radioactif. Les fractions sanguines qui peuvent participer au transport de l'or colloidal sont les hematies, les leucocytes et elements histiocytaires, et le plasma. La repartition de la radioactivite dans ces elements est precisee en pratiquant des autoradiographies de coupes de culots de sang centrifuge et congele apres incubation avec de l'or colloidal. Cette etude montre l'importance du plasma dans le transport des particules radioactives. Nous avons alors recherche une fixation eventuelle de l'or colloidal 198 sur les diverses proteines seriques en appliquant certaines methodes de separation a savoir une filtration-exclusion sur colonne de gel de Sephadex G-200 et un fractionnement electrophoretique sur papier et sur acetate de cellulose gelatineux (cellogel). Nous avons etudie la liaison ''in vitro'' et ''in vivo'' des particules colloidales d'or 198 d'abord avec les proteines seriques de sujets sains puis avec les proteines des liquides d'epanchement d'origine pathologique, chez l'homme, ou du a une inflammation experimentale a la carragenine chez le rat. Les particules d'or colloidal 198 de 30 m{mu} (S-2) sont liees dans une certaine mesure aux {alpha}2 globulines sanguines ou ascitiques, celles de 5 m{mu} (S-6) sont liees aux {alpha}1 globulines de meme que les grains contenus dans l'or polydisperse. Cette liaison semble intervenir grace a la couche protectrice de macromolecules constituees par la gelatine. Seules les caracteristiques physicochimiques de grains colloidaux peuvent expliquer leur difference de localisation sur l'electrophoregramme. L'or sous forme ionique, par contre, est combine, aux seules albumines si la quantite de metal presente ne depasse pas une certaine limite. (auteur)

Measurements of optical properties for tropospheric aerosols in the Artic; Messung von optischen Eigenschaften troposphaerischer Aerosole in der Arktis

Energy Technology Data Exchange (ETDEWEB)

Schumacher, R.

2001-07-01

Two different methods for the derivation of the altitude resolved aerosol extinction profiles are applied. The Klett method, which needs only the elastical backscattered lidar signal, allows the determination of the extinction coefficient indirectly at day and nighttime. For the Klett method an assumption of the extinction-to-backscatter ratio, often called 'lidar ratio', is necessary. This can be determined iteratively by combining with the airborne photometer measurements. With this method small scale inhomogenities and the high variability of fine structured aerosol layers can be recorded. In contract to this the Raman method allows to calculate the extinction coefficient without an assumption of the lidar ratio. Here only the Raman backscattered light from nitrogen is used. The procedure is limited in temporal and spatial resolution because the Raman backscatter cross section is smaller than the elastic backscatter cross section by three orders of magnitude. A sensitivity study shows the feasibility of this method. (orig.) [German] In dieser Arbeit werden zwei unterschiedliche Methoden zur Ableitung hochaufgeloester Extinktionsprofile des troposphaerischen Aerosols angewendet. Die Klett-Methode, in die ausschliesslich die elastisch rueckgestreuten Lidarsignale eingehen, erlaubt es indirekt auch waehrend des Polartages hochaufgeloeste Extinktionsprofile abzuleiten. Hierzu ist die Annahme ueber das Extinktions-zu-Rueckstreuverhaeltnisses, welches haeufig auch als Lidarverhaeltnis bezeichnet wird, notwendig. Dieses wird durch Kombination mit den flugzeuggetragenen Photometermessungen iteriert. Mit dieser Methode koennen somit auch kleinskalige Inhomogenitaeten aufgeloest und die hohe zeitliche Variabilitaet der Aerosolschichten erfasst werden. Im Gegensatz hierzu bietet die Raman-Methode den Vorteil, die Aerosol-Extinktion direkt ohne Annahme des Lidarverhaeltnisses abzuleiten. Bei der Ableitung der Aerosolextinktion gehen ausschliesslich die an

New Research Required in Support of Radioactive Waste Disposal; Recherches Nouvelles Necessitees par le Probleme de l'Elimination des Dechets Radioactifs; 041d 0415 041e 0411 0425 041e 0414 ; Nuevas Investigaciones Necesarias para la Evacuacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Schaefer, Milner B. [Inter-American Tropical Tuna Commission, Scripps Institution of Oceanography, La Jolla, CA (United States)

1960-07-01

foraines typiques, sur les processus de diffusion et de sedimentation dans les eaux proches du rivage et sur le passage des elements radioactifs tout le long de la chaine alimentaire dans cette partie de la mer. Il faut entreprendre des recherches pour delimiter les zones de peche presentes et eventuelles et les zones ou la peche ne se fait pas, en procedant a des etudes fondamentales sur la productivite biologique ou en recourant a d'autres moyens. Des etudes sont egalement necessaires pour determiner les taux de transfert de matieres radioactives entre les diverses zones par amenee hori-zontale et par diffusion turbulente, les taux de dilution par diffusion, sedimentation et transport vertical, et les taux d'entrainement et de transfert par les organismes. Une recherche s'impose en ce qui concerne les moyens efficaces de controle des zones d'evacuation des dechets. Certains organismes sont capables de concentrer selectivement des elements determines ;1 cette capacite constitue une base economique eventuelle pour le controle des dechets radioactifs existant dans la mer a des concentrations extremement faibles. Des propositions precises de recherche ont ete recemment mises au point par plusieurs groupes d'oceanographes aux Etats-Unis. Ces propositions ont ete resumees en meme temps que les estimations de. depenses y afferentes. (author) [Spanish] Numerosos son los procesos fisicos, quimicos y biologicos que influyen en la forma en que las sustancias radiactivas se distribuyen y vuelven al hombre. Entre ellos figuran la conveccion vertical y horizontal; la difusion turbulenta; la precipitacion y sedimentacion; la captacion, concentracion y transporte de los materiales radiactivos por organismos, y su paso al hombre por ingestion de alimentos de origen marino. Hay que estudiar urgentemente las caracteristicas del flujo y reflujo de las aguas en puertos tipicos, estuarios y aguas costeras abiertas ; los procesos de difusion y sedimentacion en las aguas costeras, y el paso de

Dissolution process of atmospheric aerosol particles into cloud droplets; Processus de dissolution des aerosols atmospheriques au sein des gouttes d'eau nuageuses

Energy Technology Data Exchange (ETDEWEB)

Desboeufs, K

2001-01-15

Clouds affect both climate via the role they play in the Earth's radiation balance and tropospheric chemistry since they are efficient reaction media for chemical transformation of soluble species. Cloud droplets are formed in the atmosphere by condensation of water vapour onto aerosol particles, the cloud condensation nuclei (CCN). The water soluble fraction of these CCN governs the cloud micro-physics, which is the paramount factor playing on the radiative properties of clouds. Moreover, this soluble fraction is the source of species imply in the oxidation/reduction reactions in the aqueous phase. Thus, it is of particular importance to understand the process controlling the solubilization of aerosols in the cloud droplets. The main purpose of this work is to investigate experimentally and theoretically the dissolution of particles incorporated in the aqueous phase. From the studies conducted up to now, we have identify several factors playing on the dissolution reaction of aerosols. However, the quantification of the effects of these factors is difficult since the current means of study are not adapted to the complexity of cloud systems. First, this work consisted to perform a experimental system, compound by an open flow reactor, enabling to follow the kinetic of dissolution in conditions representative of cloud. This experimental device is used to a systematic characterisation of the known factors playing on the dissolution, i.e. pH, aerosol nature, aerosol weathering... and also for the identification and the quantification of the effects of other factors: ionic strength, acid nature, clouds processes. These experiments gave quantitative results, which are used to elaborate a simple model of aerosol dissolution in the aqueous phase. This model considers the main factors playing on the dissolution and results in a general mechanism of aerosol dissolution extrapolated to the cloud droplets. (author)

Decontamination of lead by fusion (1962); Decontamination du plomb par fusion (1962)

Energy Technology Data Exchange (ETDEWEB)

Boutot, P; Giachetto, L; Capitaine, A [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1962-07-01

Various attempts to decontaminate using mechanical and chemical methods having given questionable results, a fusion method has been developed. The apparatus consists of a propane-heated oven fitted with a steel crucible of 1 400 kg capacity, with two ventilation systems, and with a vacuum gauge for preventing the diffusion of toxic gases. There are three operational controls : 1. On the samples taken before during and after the operation, 2. On the plugs taken from the ingots, 3. On the ingot itself. The continuous sanitary control is done by a radioactive aerosol recorder and by periodic sampling. This decontamination process will be improved, especially as far as the productivity and the safety precautions are concerned. (authors) [French] Divers essais de decontamination par voies mecaniques et chimiques ayant donne des resultats discutables, un procede par fusion a ete mis au point. L'appareil se compose d'un four, chauffe au propane, muni d'un creuset en acier d'une capacite de 1 400 kg, de deux systemes de ventilation et d'un deprimometre afin d'eviter la diffusion de vapeurs nocives. Trois controles d'activite sont effectues: 1. sur des echantillons preleves avant, pendant et apres l'operation, 2. sur des carottages realises sur les lingots, 3. sur le lingot lui-meme. Le controle sanitaire permanent est assure par un enregistreur d'aerosols radioactifs et par des prelevements periodiques. Ce procede de decontamination doit encore etre ameliore, principalement en ce qui concerne la productivite et la securite. (auteurs)

Development of a modal model for the description of the chemistry and physics of clouds and aerosols and whose implementation in the EURAD-model-system for the description of modifications of the actinic flux caused by aerosols. Final report; Entwicklung eines modalen Modells zur Beschreibung der Chemie und Physik von Wolken und Aerosolen und dessen Implementierung in das EURAD-Modellsystem zur Beschreibung aerosolbedingter Modifikationen des aktinischen Flusses. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Friese, E.; Memmesheimer, M.; Ebel, A.; Kerschgens, M.

2001-07-01

In cooperation with the Ford Research Center Aachen a trimodal version of the Modal Aerosol Dynamics Model for Europe (MADE) has been developed further and implemented into the EURAD model system. Model components for aerosol cloud interactions and secondary organic aerosols have implemented. Parameterizations of aerosol cloud interactions have verified in cooperation with the Institut fuer Troposphaerenforschung (IFT) and the university of Cottbus (BTU). Model results for episodes in summertime and wintertime 1997 have compared with measurements of PM{sub 10}-concentrations from the department of the environment of Northrine-Westfalia. Inside the area of Northrine-Westfalia the modelled PM{sub 10}-concentrations are largely in agreement with the assessment principles for air quality models recommended by the European Union. Modelled sulphate and TSP-concentrations have compared with measurements at stations from the EMEP network. The developed aerosol dynamics model is useful for the realization and control of air quality directives passed by the European Union. The numerical simulation of modifications of the Actinic flux caused by aerosols have prepared. Technical problems remain concerning the numerical description of the size-composition distribution of cloud droplets. Furthermore the determination of the soot fraction of aerosol particles is very uncertain at the moment. For this reasons an implementation of the numerical simulation of modifications of the Actinic flux caused by aerosol particles have put on the back burner. (orig.) [German] In Kooperation mit dem Ford Forschungszentrum Aachen (FFA) wurde eine trimodale Version des Modalen Aerosol-Dynamik Modells fuer Europa (MADE) in das EURAD-Modellsystem implementiert und weiterentwickelt. Weiterhin wurden Module fuer die Wechselwirkungen von Aerosolen und Wolken sowie zur Bildung von sekundaerem organischen Aerosol implementiert. Die Funktionsfaehigkeit dieser Module wurde mit Modellrechnungen ueberprueft

Treatment and Processing of Radioactive Wastes; Traitement des Dechets Radioactifs; 041e 0411 0420 0414 ; Tratamiento de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Rodger, Walton A. [Chemical Engineering Division, Argonne National Laboratory, Lemont, IL (United States)

1960-07-01

'auteur decrit des installations type. On a envisage la possibilite d'incinerer les dechets combustibles et l'auteur decrit cette methode en precisant les modalites d'application. La mise en paquets peut souvent completer utilement la collecte des dechets. L'auteur etudie un certain nombre de procedes pour les dechets liquides. Il decrit egalement des systemes type en expliquant leur fonctionnement. Dechets de haute radioactivite - Les gaz sont parfois decharges directement dans des cheminees, mais le plus souvent on leur fait subir certains traitements. On peut, soit les epurer par des processus chimiques, retirer l'iode par reaction avec l'argent, extraire les gaz rares ou encore recourir au filtrage. Les solides fortement contamines peuvent necessiter une decontamination sur place avant la collecte. Les dechets liquides fortement radioactifs constituent a l'heure actuelle la plus forte proportion de dechets a eliminer par l'industrie. On a cherche a resoudre le probleme en reduisant le volume des dechets produits en changeant le processus ; on peut aussi concentrer les dechets produits ou bien les reduire sous forme solide - plusieurs methodes sont employees a cet effet, notamment la concentration, l'utilisation de ciment de Portland, l'adsorption sur argile ou autre materiau naturel et la calcination. L'auteur examine les problemes techniques et economiques qui se posent a propos de l'entreposage provisoire. Il peut etre necessaire de ne traiter les dechets qu'en un petit nombre d'endroits soigneusement determines. L'auteur a calcule approximativement les quantites et le materiel necessaire au deplacement. Il etudie egalement les risques afferents et les incidences financieres. (author) [Spanish] El autor examina algunos de los metodos que se han propuesto para tratar los desechos radiactivos de baja y elevada actividad. Desechos de baja actividad - Una vez diluidos, los gases se descargan en la atmosfera mediante chimeneas o se hacen pasar por filtros de elevado poder de

Modelling and numerical simulation of the General Dynamic Equation of aerosols; Modelisation et simulation des aerosols atmospheriques

Energy Technology Data Exchange (ETDEWEB)

Debry, E.

2005-01-15

Chemical-transport models are now able to describe in a realistic way gaseous pollutants behavior in the atmosphere. Nevertheless atmospheric pollution also exists as fine suspended particles, called aerosols, which interact with gaseous phase, solar radiation, and have their own dynamic behavior. The goal of this thesis is the modelling and numerical simulation of the General Dynamic Equation of aerosols (GDE). Part I deals with some theoretical aspects of aerosol modelling. Part II is dedicated to the building of one size resolved aerosol model (SIREAM). In part III we perform the reduction of this model in order to use it in dispersion models as POLAIR3D. Several modelling issues are still opened: organic aerosol matter, externally mixed aerosols, coupling with turbulent mixing, and nano-particles. (author)

Origins of atmospheric aerosols. Basic concepts on aerosol main physical properties; L`aerosol atmospherique: ses origines quelques notions sur les principales proprietes physiques des aerosols

Energy Technology Data Exchange (ETDEWEB)

Renoux, A. [Paris-12 Univ., 94 - Creteil (France). Laboratoire de Physique des aerosols et de transferts des contaminations

1996-12-31

Natural and anthropogenic sources of atmospheric aerosols are reviewed and indications of their concentrations and granulometry are given. Calculation of the lifetime of an atmospheric aerosol of a certain size is presented and the various modes of aerosol granulometry and their relations with photochemical and physico-chemical processes in the atmosphere are discussed. The main physical, electrical and optical properties of aerosols are also presented: diffusion coefficient, dynamic mobility and relaxation time, Stokes number, limit rate of fall, electrical mobility, optical diffraction

Infrared remote sensing of atmospheric aerosols; Apports du sondage infrarouge a l'etude des aerosols atmospheriques

Energy Technology Data Exchange (ETDEWEB)

Pierangelo, C

2005-09-15

The 2001 report from the Intergovernmental Panel on Climate Change emphasized the very low level of understanding of atmospheric aerosol effects on climate. These particles originate either from natural sources (dust, volcanic aerosols...) or from anthropogenic sources (sulfates, soot...). They are one of the main sources of uncertainty on climate change, partly because they show a very high spatio-temporal variability. Observation from space, being global and quasi-continuous, is therefore a first importance tool for aerosol studies. Remote sensing in the visible domain has been widely used to obtain a better characterization of these particles and their effect on solar radiation. On the opposite, remote sensing of aerosols in the infrared domain still remains marginal. Yet, not only the knowledge of the effect of aerosols on terrestrial radiation is needed for the evaluation of their total radiative forcing, but also infrared remote sensing provides a way to retrieve other aerosol characteristics (observations are possible at night and day, over land and sea). In this PhD dissertation, we show that aerosol optical depth, altitude and size can be retrieved from infrared sounder observations. We first study the sensitivity of aerosol optical properties to their micro-physical properties, we then develop a radiative transfer code for scattering medium adapted to the very high spectral resolution of the new generation sounder NASA-Aqua/AIRS, and we finally focus on the inverse problem. The applications shown here deal with Pinatubo stratospheric volcanic aerosol, observed with NOAA/HIRS, and with the building of an 8 year climatology of dust over sea and land from this sounder. Finally, from AIRS observations, we retrieve the optical depth at 10 {mu}m, the average altitude and the coarse mode effective radius of mineral dust over sea. (author)

Dissolution process of atmospheric aerosol particles into cloud droplets; Processus de dissolution des aerosols atmospheriques au sein des gouttes d'eau nuageuses

Energy Technology Data Exchange (ETDEWEB)

Desboeufs, K.

2001-01-15

Clouds affect both climate via the role they play in the Earth's radiation balance and tropospheric chemistry since they are efficient reaction media for chemical transformation of soluble species. Cloud droplets are formed in the atmosphere by condensation of water vapour onto aerosol particles, the cloud condensation nuclei (CCN). The water soluble fraction of these CCN governs the cloud micro-physics, which is the paramount factor playing on the radiative properties of clouds. Moreover, this soluble fraction is the source of species imply in the oxidation/reduction reactions in the aqueous phase. Thus, it is of particular importance to understand the process controlling the solubilization of aerosols in the cloud droplets. The main purpose of this work is to investigate experimentally and theoretically the dissolution of particles incorporated in the aqueous phase. From the studies conducted up to now, we have identify several factors playing on the dissolution reaction of aerosols. However, the quantification of the effects of these factors is difficult since the current means of study are not adapted to the complexity of cloud systems. First, this work consisted to perform a experimental system, compound by an open flow reactor, enabling to follow the kinetic of dissolution in conditions representative of cloud. This experimental device is used to a systematic characterisation of the known factors playing on the dissolution, i.e. pH, aerosol nature, aerosol weathering... and also for the identification and the quantification of the effects of other factors: ionic strength, acid nature, clouds processes. These experiments gave quantitative results, which are used to elaborate a simple model of aerosol dissolution in the aqueous phase. This model considers the main factors playing on the dissolution and results in a general mechanism of aerosol dissolution extrapolated to the cloud droplets. (author)

Solidification of Radioactive Waste Solutions; Solidification des Effluents Radioactifs; 041e 0422 0412 0415 0420 0416 0414 0415 041d 0418 0415 0420 0410 0414 0418 041e 0410 041a 0422 0418 0412 041d 042b 0425 0421 0411 0420 041e 0421 041d 042b 0425 0420 0410 0421 0422 0412 041e 0420 041e 0412 ; Solidificacion de Efluentes Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Brezhneva, N. E.; Golovanov, Ju. N.; Oziraner, S. N.; Eremin, A. A.; Rozanova, V. N.

1963-02-15

This paper sets out the results of experimental development of a method for the solidifaction of radioactive waste solutions, based on the drying and vitrification of precipitates of iron-hydroxide obtained by settling from radioactive solutions. The solidification system is based on the principle of maximum reduction of the waste off-gases after removal of the aerosols and volatile radioactive components. The authors established optimum conditions to obtain a chemically stable glass and succeeded in lowering the temperature for the melting of the glass by modifying the fluxes added. An appreciable drop in the chemical stability of the glass was noted when it was stored for a long time at temperatures above 300 Degree-Sign - 350 Degree-Sign C. The authors studied the leachability of radiocaesium from the glass. They also investigated the volatility of radiocaesium and radio ruthenium in the course of drying and melting and showed that in an atmosphere of carbonic acid gas the volatility of ruthenium completely disappears. Hie volatility of radiocaesium in appreciable quantities becomes noticeable at temperatures above 700 Degree-Sign C and increases as the temperature rises. It is shown that radiocaesium condenses in the drainage tubes at temperatures below 400 Degree-Sign C and is easily washed off by weak solutions of nitric acid and water. Calculations of the heat release from radioactive glass show that the radius of globular glass castings from high-activity materials (10 c/g) must not exceed 25 cm. The paper includes the flowsheet for a process for the drying and vitrification of radioactive sludge by means of a gas- and heat-remover, together with details of the apparatus required. (author) [French] Les auteurs exposent les resultats des recherches qu'ils ont faites, dans leur laboratoire, pour mettre au point une methode de solidification des effluents radioactifs, fondee sur la dessiccation et la vitrification de l'hydroxyde de fer, obtenu par

Assimilation of Polder aerosol optical thickness into LMD2-Inca model in order to study aerosol-climate interactions; Etude des interactions entre aerosols et climat: assimilation des observations spatiales de Polder dans LMDz-Inca

Energy Technology Data Exchange (ETDEWEB)

Generoso, S.

2004-12-15

Aerosols influence the Earth radiative budget both through their direct (scattering and absorption of solar radiation) and indirect (impacts on cloud microphysics) effects. The anthropogenic perturbation due to aerosol emissions is of the same order of magnitude than the one due to greenhouse gases, but less well known. To improve our knowledge, we need to better know aerosol spatial and temporal distributions. Indeed, aerosol modeling still suffers from large uncertainties in sources and transport, while satellite observations are incomplete (no detection in the presence of clouds, no information on the vertical distribution or on the chemical nature). Moreover, field campaigns are localized in space and time. This study aims to reduce uncertainties in aerosol distributions, developing assimilation of satellite data into a chemical transport model. The basic idea is to combine information obtained from spatial observation (optical thickness) and modeling studies (aerosol types, vertical distribution). In this study, we assimilate data from the POLDER space-borne instrument into the LMDz-INCA model. The results show the advantage of merging information from different sources. In many regions, the method reduces uncertainties on aerosol distribution (reduction of RMS error). An application of the method to the study of aerosol impact on cloud microphysics is shown. (author)

Infrared remote sensing of atmospheric aerosols; Apports du sondage infrarouge a l'etude des aerosols atmospheriques

Energy Technology Data Exchange (ETDEWEB)

Pierangelo, C.

2005-09-15

The 2001 report from the Intergovernmental Panel on Climate Change emphasized the very low level of understanding of atmospheric aerosol effects on climate. These particles originate either from natural sources (dust, volcanic aerosols...) or from anthropogenic sources (sulfates, soot...). They are one of the main sources of uncertainty on climate change, partly because they show a very high spatio-temporal variability. Observation from space, being global and quasi-continuous, is therefore a first importance tool for aerosol studies. Remote sensing in the visible domain has been widely used to obtain a better characterization of these particles and their effect on solar radiation. On the opposite, remote sensing of aerosols in the infrared domain still remains marginal. Yet, not only the knowledge of the effect of aerosols on terrestrial radiation is needed for the evaluation of their total radiative forcing, but also infrared remote sensing provides a way to retrieve other aerosol characteristics (observations are possible at night and day, over land and sea). In this PhD dissertation, we show that aerosol optical depth, altitude and size can be retrieved from infrared sounder observations. We first study the sensitivity of aerosol optical properties to their micro-physical properties, we then develop a radiative transfer code for scattering medium adapted to the very high spectral resolution of the new generation sounder NASA-Aqua/AIRS, and we finally focus on the inverse problem. The applications shown here deal with Pinatubo stratospheric volcanic aerosol, observed with NOAA/HIRS, and with the building of an 8 year climatology of dust over sea and land from this sounder. Finally, from AIRS observations, we retrieve the optical depth at 10 {mu}m, the average altitude and the coarse mode effective radius of mineral dust over sea. (author)

The use of 65Zn in the study of Heliothis armigera larva's behavior on tomatoes

International Nuclear Information System (INIS)

Saour, George.

1987-01-01

Short communication. A summary of a DEA report submitted under the title ''Etude au moyen du Zinc Radioactif 65 Zn du comportement des chenilles d'Heliothis armigera hubner (Lepidoptera, Noctuidae) sur Tomate.'' Univ. de Droit d'Economie et des Sciences d'Aix-Marseille-III. Faculte des Sciences et Techniques de Saint-Jerome. INRA-MONTEAVET, Station de Zoologie

A study of some radioprotection apparatuses used in the case of pool reactors; Etude de quelques dispositifs de radioprotection en service aupres des piles piscines

Energy Technology Data Exchange (ETDEWEB)

Robien, E de; Choudens, H de; Delpuech, J [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1965-07-01

necessite de mesurer avec une bonne precision des doses {gamma} a l'aide d'un appareil autonome a conduit a la realisation d'un dosiinetre {gamma} a scintillateur plastique; d) l'obligation de condamner l'ouverture des portes de certains locaux ou il risque d'y avoir une intensite de rayonnement forte a conduit a realiser un asservissement de l'ouverture de ces portes a l'intensite de rayonnement a l'interieur des locaux; e) les degagements d'iode radioactif ont ete mesures a l'aide de cartouches de charbon actif entourant un scintillateur relie a un monocanal; f) enfin, la commande de chute des barres des piles, en cas d'accident radioactif, a ete assuree par une chaine dont le detecteur est une chambre immergee dans la piscine, ce qui offre, dans le cas particulier des reacteurs piscines a couche chaude, le double avantage de pouvoir 'piloter' la couche chaude et de s'affranchir des rayonnements transitoires apparaissant dans le hall du reacteur au moment du defournement des dispositifs experimentaux. (auteurs)

Modeling of pollution aerosols in Ile-de-France; Modelisation des aerosols de pollution en Ile-de-France

Energy Technology Data Exchange (ETDEWEB)

Hodzic, A

2005-10-15

The modeling of aerosols is a major stake in the understanding of the emission processes and evolution of particulates in the atmosphere. However, the parameterizations used in today's aerosol models still comprise many uncertainties. This work has been motivated by the need of better identifying the weaknesses of aerosols modeling tools and by the necessity of having new validation methods for a 3D evaluation of models. The studies have been carried out using the CHIMERE chemistry-transport model, which allows to simulate the concentrations and physico-chemical characteristics of pollution aerosols at the European scale and in Ile-de-France region. The validation approach used is based on the complementarity of the measurements performed on the ground by monitoring networks with those acquired during the ESQUIF campaign (study and simulation of air quality in Ile-de-France), with lidar and photometric measurements and with satellite observations. The comparison between the observations and the simulations has permitted to identify and reduce the modeling errors, and to characterize the aerosol properties in the vicinity of an urban area. (J.S.)

Modeling of pollution aerosols in Ile-de-France; Modelisation des aerosols de pollution en Ile-de-France

Energy Technology Data Exchange (ETDEWEB)

Hodzic, A

2005-10-15

The modeling of aerosols is a major stake in the understanding of the emission processes and evolution of particulates in the atmosphere. However, the parameterizations used in today's aerosol models still comprise many uncertainties. This work has been motivated by the need of better identifying the weaknesses of aerosols modeling tools and by the necessity of having new validation methods for a 3D evaluation of models. The studies have been carried out using the CHIMERE chemistry-transport model, which allows to simulate the concentrations and physico-chemical characteristics of pollution aerosols at the European scale and in Ile-de-France region. The validation approach used is based on the complementarity of the measurements performed on the ground by monitoring networks with those acquired during the ESQUIF campaign (study and simulation of air quality in Ile-de-France), with lidar and photometric measurements and with satellite observations. The comparison between the observations and the simulations has permitted to identify and reduce the modeling errors, and to characterize the aerosol properties in the vicinity of an urban area. (J.S.)

Study of the diffusion of iron, of silver and of carbon in beryllium using radioactive tracers; Etude de la diffusion du fer, de l'argent et du carbone dans le beryllium au moyen des traceurs radioactifs

Energy Technology Data Exchange (ETDEWEB)

Naik, M Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-06-01

A study has been made of the diffusion of radioactive iron and silver tracers in beryllium. The following values have been found. D{sub Fe} = 0.53 exp - [51800 / RT], D{sub Ag} = 62 exp - [46100 / RT]. The values for iron are in good agreement with those found previously for chemical diffusion. A comparison of the diffusion coefficients for iron, silver and nickel shows that the diffusion rate increases with increasing solute atom radius. The existence has been shown of diffusion anisotropy for silver; it has been studied quantitatively on monocrystals. It is found that: D{sub parallel} 0.41 exp - [39100 / RT], D{sub perpendicular} = 1.98 exp - [45700 / RT]. The anisotropy decreases as the temperature increases. The silver diffuses more rapidly along the C axis than in the base plane. This result cannot be explained in terms of the model proposed for the diffusion of foreign atoms in solution in zinc. A greater number of experiments is required before a model can be put forward. An attempt has also been made to determine the diffusion coefficients of carbon in beryllium by treatment in an atmosphere of acetylene marked with C-14. Diffusion coefficients have been obtained but these should not be considered to be very significant since a chemical reaction occurs at the surface of the samples. (author) [French] On a etudie la diffusion dans le beryllium de traceurs radioactifs du fer et de l'argent. On trouve: D{sub Fe} = 0.53 exp - [51800 / RT], D{sub Ag} = 62 exp - [46100 / RT].Les valeurs trouvees pour le fer sont en bon accord avec les valeurs obtenues precedemment pour la diffusion chimique. La comparaison des coefficients de diffusion du fer, de l'argent et du nickel montre que la diffusion est d'autant plus rapide que le rayon atomique du solute est plus grand. On a mis en evidence une anisotropie de diffusion de l'argent qui a ete etudiee quantitativement sur des monocristaux. On trouve: D{sub parallele} = 0.41 exp - [39100 / RT], D{sub perpendiculaire} = 1

Pharmacological study of radioactive-gold colloid transport by blood and by serous exudate; Contribution a l'etude pharmacologique du transport des colloides d'or radioactif par le sang et les exsudats sereux

Energy Technology Data Exchange (ETDEWEB)

Rousselet, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1966-06-01

substances et particulierement dans le transport de l'or colloidal radioactif. Les fractions sanguines qui peuvent participer au transport de l'or colloidal sont les hematies, les leucocytes et elements histiocytaires, et le plasma. La repartition de la radioactivite dans ces elements est precisee en pratiquant des autoradiographies de coupes de culots de sang centrifuge et congele apres incubation avec de l'or colloidal. Cette etude montre l'importance du plasma dans le transport des particules radioactives. Nous avons alors recherche une fixation eventuelle de l'or colloidal 198 sur les diverses proteines seriques en appliquant certaines methodes de separation a savoir une filtration-exclusion sur colonne de gel de Sephadex G-200 et un fractionnement electrophoretique sur papier et sur acetate de cellulose gelatineux (cellogel). Nous avons etudie la liaison ''in vitro'' et ''in vivo'' des particules colloidales d'or 198 d'abord avec les proteines seriques de sujets sains puis avec les proteines des liquides d'epanchement d'origine pathologique, chez l'homme, ou du a une inflammation experimentale a la carragenine chez le rat. Les particules d'or colloidal 198 de 30 m{mu} (S-2) sont liees dans une certaine mesure aux {alpha}2 globulines sanguines ou ascitiques, celles de 5 m{mu} (S-6) sont liees aux {alpha}1 globulines de meme que les grains contenus dans l'or polydisperse. Cette liaison semble intervenir grace a la couche protectrice de macromolecules constituees par la gelatine. Seules les caracteristiques physicochimiques de grains colloidaux peuvent expliquer leur difference de localisation sur l'electrophoregramme. L'or sous forme ionique, par contre, est combine, aux seules albumines si la quantite de metal presente ne depasse pas une certaine limite. (auteur)

Soil contamination. part 1. changes in the humidity of non saturated soils after reject in a limited space. part 2. movements of radioactive ions in non saturated soils after reject in a limited space; Contamination des sols (1. partie). Evolution de l'humidite dans les sols non satures apres rejets sur une surface limitee. (2. partie). Comportement des ions radioactifs dans les sols non satures apres rejets d'eau sur une surface limitee

Energy Technology Data Exchange (ETDEWEB)

Rancon, D [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

1972-07-01

upon the counting rate of radioactivity. This method which have allowed to get various results about {sup 131}I and {sup 85}Sr can be generalized to other radioisotopes and other soils. They are applicable to radiological safety of sites studies : Testing storage plants, estimate of accidents hazards and protection of subterranean waters. (author) [French] II est important, dans les etudes de surete radiologique de sites, de connaitre les mouvements d'eau dans les terrains non satures surmontant la nappe aquifere, cette tranche de terrain aere pouvant servir de protection contre la contamination de la nappe. L'utilisation d'humidimetres a neutrons a permis de construire graphiquement les coupes des etats hydriques du terrain et les evolutions dans le temps du volume du sol mouille a partir d'un rejet affectant une superficie restreinte. On mesure aussi les gradients d'humidite, les cinetiques d'assechement, la capacite de retention du sol et la teneur en eau gravifique suspendue en en equilibre avec la charge d'eau. L'etat hydrique initial influence la vitesse d'infiltration et non la vitesse d'avancement du front d'humectation, on peut donc calculer la quantite d'eau accumulable par le terrain. Apres l'arret du rejet, le volume de sol mouille evolue jusqu'a un etat d'equilibre limite par le front d'humectation, les redistributions d'humidite s'effectuant seulement au sein de ce volume; ainsi, en cas de rejet de liquide radioactif, les ions contaminants resteront confines dans un volume mesurable limite par le front d'humectation. Partie 2. Pour faire suite au rapport sur les mouvements d'eau dans les sols non satures apres rejet sur une surface limitee - CEA R 3635 (1) - on etudie les mouvements des ions radioactifs dans ces sols en utilisant un anion et un cathion caracteristiques: l'iode 131 et le strontium 85. La methode est basee sur la mesure simultanee des fronts d'humidite et d'activite au moyen d'humidimetre a neutrons et d'une sonde d'activite specialement

Treatment of Radioactive Waste at Japan's Atomic Energy Research Institute; Traitement des Dechets Radioactifs a l'Institut Japonais de Recherches sur l'Energie Atomique; 041e 0411 0420 0410 0411 041e 0422 041a 0410 0420 0410 0414 ; Tratamiento de los Desechos Radiactivos en el Instituto de Investigaciones sobre Energia Atomica del Japon

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, Yutaka [University of Toyko (Japan); Japan Atomic Energy Research Institute (Japan); Ito, Masukuni F.; Ishihara, Takehiko; Mitsuishi, Nobuo [Sadahiro Sakata, Japan Atomic Energy Research Institute (Japan)

1960-07-01

The paper describes the origin, nature and treatment of the radioactive wastes. The very low-level liquid waste is diluted and released to the sea, while the low- and medium-level liquid waste is treated by flocculation, evaporation and ion-exchange methods. The solid waste is collected and the combustible waste incinerated. (author) [French] Le present memoire decrit l'origine, la nature et le traitement des dechets radioactifs. Les dechets liquides de tres faible activite sont dilues et evacues dans la mer, tandis que les dechets liquides d'activite faible et moyenne sont traites par des methodes de floculation, d'evaporation et d'echange d'ions. Les dechets solides sont rassembles et les dechets combustibles sont incineres. (author) [Spanish] Los aiutores describen el origen y la naturaleza de los desechos radiactivos, asi como los metodos seguidos para su tratamiento. Los desechos liquidos de muy bajo nivel de actividad se diluyen primero y luego se descargan en el mar, en tanto que los desechos liquidos de bajo y mediano nivel se tratan mediante procedimientos de floculacion, evaporacion e intercambio ionico. Los residuos solidos se acopian y los residuos combustibles se incineran. (author) [Russian] V dokumente opisyvajutsja priroda i harakter radioaktivnyh othodov i metody ih obrabotki. Zhidkie othody ochen' nizkoj aktivnosti razbavljajutsja i otvodjatsja v morja, a zhidkie othody nizkoj i srednej aktivnosti obrabatyvajutsja metodami flokkuljacii, vyparivanija i ionnogo obmena. Tverdye othody sobirajutsja i po vozmozhnosti szhigajutsja. (author)

Treatment of effluent at the Saclay Centre d'Etudes Nucleaires (1960); Le traitement des effluents du Centre d'Etudes Nucleaires de Saclay (1960)

Energy Technology Data Exchange (ETDEWEB)

Wormser, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The Centre d'Etudes Nucleaires at Saclay possesses several installations from which liquid radioactive effluent is rejected, and it has thus been found necessary to construct a station for the purification of radioactive liquids and to settle various chemical, analytical and technological problems. This report describes, in the following order: - the disposal possibilities at the Centre d'Etudes Nucleaires, Saclay, - the effluents produced at the centre, - the set-up for collecting effluent, - treatment of the effluent, - results of these treatments. (author) [French] La presence, au Centre d'Etudes Nucleaires de Saclay, de plusieurs installations susceptibles de rejeter des effluents liquides radioactifs a necessite la construction d'une station d'epuration d'eaux radioactives et la mise au point de differents problemes chimiques, analytiques et technologiques. Dans ce rapport, nous exposerons successivement: - les possibilites de rejet du Centre d'Etudes Nucleaires de Saclay, - les effluents du centre, - le dispositif de collecte des effluents, - le traitement de ces effluents, - les resultats de ces traitements. (auteur)

The pretreatment of uranium ores by physical processing; Les problemes de la preconcentration des minerais d'uranium par voie physique

Energy Technology Data Exchange (ETDEWEB)

Vuchot, L; Ginocchio, A; Hubert, G; Roques, E; Sandier, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

After giving an outline of the classical means of physical processing - granulometry, gravimetry, flotation, magnetism, electrostatics, the authors study the methods peculiar to radioactive ores: pretreatment in batches (counting cylinders) or stone by stone (electronic sorting belt). The three factors to be considered in any treatment operation are studied (cost of the operation, metal recovery, ratio of concentration), as well as their bearing on the cost and the productivity of the following operations. Making use of radioactivity in order to find out instantaneously the approximate grade of the obtained product makes it possible to reduce costs and improve results by setting up total automation. (author) [French] Apres un apercu des procedes classiques de concentration physique des minerais - granulometrie, gravimetrie, flottation, magnetisme et electrostatique, les auteurs s'attachent aux methodes propres aux minerais radioactifs: preconcentration par lots (cylindre de comptage) ou caillou par caillou (bande de triage electronique). Les trois facteurs a considerer lors de toute operation de traitement sont etudies (prix de revient de l'operation, rendement metal et rendement poids), ainsi que leurs repercussions sur les prix de revient et rendements des traitements ulterieurs. L'utilisation de la radioactivite pour determiner instantanement la teneur approximative des produits obtenus permet d'envisager de reduire les prix de revient et d'ameliorer les resultats par une automatisation totale. (auteur)

Contribution to the study of the biological properties of compounds labeled with radio-chromium {sup 51}Cr; Contribution a l'etude des proprietes biologiques des composes marques au radiochrome {sup 51}Cr

Energy Technology Data Exchange (ETDEWEB)

Ingrand, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-15

Among the radioisotopes commonly used in biology and medicine which are controlled Individually in the Radioelement Departement of the Saclay Nuclear Research Centre before being sent to the users, the author has chosen chromium 51 incorporated in inorganic salts or in organic substrates for a study of the biological properties of the compounds. In the first part, he has compared the pathways followed by the radioactive sodium chromate and chromic chloride mixed with blood or given to the whole animal, the object being to determine whether a reduction of hexavalent chromium occurs, both in vitro and in vivo. In the second part, the author has tried to show the validity of using, various substrates labeled with chromium 51, red cells, haemoglobin, plasma proteins and cytochrome c. The results obtained have contributed to underline the interest of using such compounds for biological applications. (author) [French] Parmi les radioisotopes d'utilisation courants en biologie et en medecine qui sont l'objet d'un controle particulier dans le Departement des Radioelements du Centre d'Etudes Nucleaires de Saclay avant leur diffusion aux utilisateurs, l'auteur a choisi le chrome 51 incorpore a des sels mineraux ou a des substrats organiques, afin d'en etudier les proprietes biologiques. Dans la premiere partie, il a compare le sort du chromate de sodium et du chlorure chromique radioactifs melanges a du sang ou administres a l'animal entier en s'efforcant de mettre en evidence une reduction du chrome hexavalent aussi bien in vitro qu'in vivo. Dans la deuxieme partie, il a cherche a etablir la validite de l'emploi de differents substrats marques au chrome 51, l'hematie, l'hemoglobine, les proteines plasmatiques et le cytochrome c. Les resultats obtenus ont permis de souligner le reel interet des applications biologiques des composes marques par le radioisotope. (auteur)

The pretreatment of uranium ores by physical processing; Les problemes de la preconcentration des minerais d'uranium par voie physique

Energy Technology Data Exchange (ETDEWEB)

Vuchot, L.; Ginocchio, A.; Hubert, G.; Roques, E.; Sandier, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

After giving an outline of the classical means of physical processing - granulometry, gravimetry, flotation, magnetism, electrostatics, the authors study the methods peculiar to radioactive ores: pretreatment in batches (counting cylinders) or stone by stone (electronic sorting belt). The three factors to be considered in any treatment operation are studied (cost of the operation, metal recovery, ratio of concentration), as well as their bearing on the cost and the productivity of the following operations. Making use of radioactivity in order to find out instantaneously the approximate grade of the obtained product makes it possible to reduce costs and improve results by setting up total automation. (author) [French] Apres un apercu des procedes classiques de concentration physique des minerais - granulometrie, gravimetrie, flottation, magnetisme et electrostatique, les auteurs s'attachent aux methodes propres aux minerais radioactifs: preconcentration par lots (cylindre de comptage) ou caillou par caillou (bande de triage electronique). Les trois facteurs a considerer lors de toute operation de traitement sont etudies (prix de revient de l'operation, rendement metal et rendement poids), ainsi que leurs repercussions sur les prix de revient et rendements des traitements ulterieurs. L'utilisation de la radioactivite pour determiner instantanement la teneur approximative des produits obtenus permet d'envisager de reduire les prix de revient et d'ameliorer les resultats par une automatisation totale. (auteur)

Use of ion exchange and early treatment of radioactive contamination in the digestive tract; Utilisation des echangeurs d'ions et traitement precoce de la contamination radioactive par voie digestive

Energy Technology Data Exchange (ETDEWEB)

Michon, G; Guilloux, M J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

The efficiency of cation exchange resins for the treatment of digestive contamination with strontium has been studied on rats. The results obtained show that the most efficient resins are those of sulfonic type when administered in the ammonium form. The treatment is still efficient when applied 45 minutes after the ingestion of strontium. In the most favourable cases, the radioactivity of the skeleton was lower by a factor 6 in the treated animals than in controls. This easily applicable, rather safe and non specific treatment deserves to be retained for use. (author) [French] Une etude de l'efficacite des resines echangeuses de cations dans le traitement d'une contamination digestive par le strontium a ete entreprise chez le rat. Les resultats montrent que parmi les resines, les plus efficaces sont celles de type sulfonique, administrees sous forme ammonium. Le traitement est encore efficace 45 minutes apres l'ingestion du strontium. Dans les meilleurs cas, le squelette des rats traites etait six fois moins radioactif que celui des temoins. Ce traitement d'emploi facile, peu dangereux, non specifique, merite d'etre retenu. (auteur)

Note from the radioprotection group's shipping service

CERN Multimedia

2006-01-01

Le service SHIPPING du groupe de radioprotection souhaite vous rappeler qu'avant toute expédition de matériel susceptible d'être radioactif, une demande de transport doit être établie par EDH en cochant la case appropriée (danger radioactif). Merci de bien vouloir prendre note des informations figurant dans le site Web: http://cern.ch/service-rp-shipping Toute demande non conforme ne sera pas prise en compte. Radioactive Shipping Service http://cern.ch/service-rp-shippingTél: 73171Fax: 69200

A Review of Radioactive Waste Disposal to the Ground at Hanford; Etude sur l'Elimination dans le Sol des Dechets Radioactifs a Hanford; 041e 0411 0417 0414 ; Evacuacion de Desechos Radiactivos en el Subsuelo de Hanford

Energy Technology Data Exchange (ETDEWEB)

Pearce, D. W.; Lindbroth, C. E.; Nelson, J. L.; Ames, Jr., L. L. [Hanford Laboratories, Hanford Atomic Products Operation, General Electric Company, Richland WA (United States)

1960-07-01

The disposal of radioactive wastes to the ground from the Hanford separations plants is summarized ; volumes of wastes and contained curies discharged to swamps, trenches, and cribs are presented. Significant literature on ion- exchange studies using Hanford soils is reviewed. A field experiment with a model crib is described; preliminary findings indicate that spreading a waste solution below a disposal facility may be of greater benefit in disposal operations than previously assumed. Further studies with the calcite-phosphate reaction are reported; significant variables which affect Sr{sup +2} removal are calcite surface area, pH of the influent, flow rate, temperature and phosphate ion concentration. Bone-seeking radioisotopes are also removed from F- solutions when contact is made with calcite. The zeolite clinoptilolite shows high selectivity for Cs{sup +} even in the presence of increased Na{sup +} concentration. The effect of the large-scale ground disposal operation at Hanford is described by means of a map and geological cross-sections showing areas and volumes of ground and ground water contamination. (author) [French] Les auteurs donnent un apercu de l'elimination dans le sol des dechets radioactifs des usines de separation des isotopes de Hanford ; ils indiquent les quantites de dechets - et de curies - qui sont evacuees dans des marecages, des tranchees et des coffres. Ils passent en revue des etudes importantes qui ont ete publiees sur les proprietes d'echangeurs d'ions des sols de Hanford. Ils decrivent une experience pratique faite avec un coffre modele; il ressort des resultats preliminaires que le fait de repandre une solution de dechets au-dessous d'une installation d'evacuation pourrait etre beaucoup plus avantageux pour les operations d'evacuation que l'on n'avait cru precedemment. Les auteurs signalent d'autres etudes fondees sur la reaction calcite-phosphate ; parmi les variables importantes qui influent sur l'elimination du Sr{sup ++}, il

The use of radioactive inserts in the study of metal deformation during tube-making processes; Emploi de fils metalliques radioactifs pour l'etude des deformations des metaux pendant la fabrication de tubes; Ispol'zovanie radioaktivnykh vtulok dlya izucheniya deformatsii metallov pri protsesse izgotovleniya trub; Empleo de insertos radiactivos en el estudio de la deformacion de los metales durante la fabricacion de tubos

Energy Technology Data Exchange (ETDEWEB)

Davison, W H.T. [Tube Investments Research Laboratories, Cambridge (United Kingdom)

1962-01-15

This paper reports on the use of radioactive inserts in studying the deformation of steel in hot rotary piercing for tube making. Iron or steel wires are activated in the pile, inserted in tubes drilled in iron or steel billets, which are then processed under normal production conditions. Careful monitoring shows that the radiation exposures and contamination of the plant are quite negligible. On cooling, the billets are scanned in the laboratory, using a collimated scintillationcounter mounted normal to the surface of the pierced billet, and isodose curves show the shape of the deformed insert normal to the tube surface. A similar scan of a section normal to the axis of the tube gives a second plot; from a combination of the two plots, a three-dimensional picture is obtained. Some results are quoted, but the main emphasis of the paper is on the experimental technique, which has quite general applicability to metal deformation studies. The insert must be located within a millimeter or thereabouts, for which a higher resolution is required than is normal in medical scanning techniques. The problems of achieving this are discussed in terms of {gamma}-energy, collimator design and energy discrimination. (author) [French] Le present memoire traite de l'emploi de fils metalliques radioactifs pour l'etude de la deformation de l'acier durant le forage rotatif a chaud en vue de la fabrication des tubes. Des fils de fer ou d'acier sont actives dans un reacteur et places dans des cavites tabulaires menagees a l'interieur de billettes de fer ou d'acier que l'on transforme ensuite dans les conditions de fabrication normales. Un controle radiologique minutieux montre que les dangers d'irradiation et de contamination dans l'usine sont pratiquement negligeables. Apres refroidissement, les billettes sont examinees en laboratoire au moyen d'un compteur a scintillations avec collimateur de faible ouverture, monte de facon que l'axe soit perpendiculaire a la surface de la billette

The electric charge of the aerosols under gamma radiation; La charge electrique des aerosols sous irradiation gamma

Energy Technology Data Exchange (ETDEWEB)

Gensdarmes, F.; Cetier, P.; Boulaud, D. [CEA/Saclay, Inst. de Protection et de Surete Nucleaire, IPSN/DPEA/SERAC, 91 - Gif-sur-Yvette (France); Renoux, A. [Paris-12 Univ., Lab. de Physique des Aerosols et de Transfert des Contaminations, 94 - Creteil (France)

2000-07-01

During a PWR type reactor accident, the gamma radiation may create a high ionized atmosphere. In such a situation the aerosols properties knowledge is useful to simulate the particles transport and deposit in the enclosed. The aim of this study is to determine the aerosol charges distribution in a high ionized medium, in function of the ionic properties of the medium. (A.L.B.)

Decontamination of surfaces (1961); La decontamination des surfaces (1961)

Energy Technology Data Exchange (ETDEWEB)

Mestre, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The continued expansion of atomic Energy has led the S.C.R.G.R. to extend simultaneously the recovery of materials contaminated by use in radio-active media. The importance of this aspect of atomic Energy was not immediately obvious to those concerned but is now fully recognized due to the cost of the materials and installations, and also to the time required for the construction of special equipment for the C.E.A. Another very important reason is the dangers associated with the handling of contaminated material. The S.C.R.G.R. attacked this problem from the point of view of these dangers. It later became apparent to the users, once the decontamination methods had proved their worth, that the process presented advantages from the material and cost-saving point of view. (author) [French] Le developpement toujours croissant de l'Energie atomique a conduit le S.C.R.G.R. a developper parallelement la recuperation des materiels contamines par leur emploi en milieu radioactif. Cet aspect de l'Energie atomique n'est pas apparu des le debut aux utilisateurs mais s'est tres vite impose etant donne, d'une part, le cout des installations et du materiel, d'autre part le temps necessaire a la fabrication d'un materiel special aux travaux du C.E.A., enfin et surtout, les risques associes a la manipulation d'un materiel contamine. Les risques seuls ont ete pris comme point de depart a l'examen de ce probleme par le S.C.R.G.R. puis avec le temps, les methodes de decontamination ayant fait leur preuve, les utilisateurs ont alors apercu les aspects materiels et la rentabilite de la decontamination. (auteur)

Environmental Implications of Radioactive Waste Disposal as Related to Stream Environments; Incidences du Milieu sur l'Elimination des Dechets Radioactifs dans le Voisinage des Cours d'Eau; 0412 041b 0418 042f 0414 ; Efectos de la Evacuacion de Desechos Radiactivos en las Corrientes Fluviales

Energy Technology Data Exchange (ETDEWEB)

Straub, Conrad P.; Goldin, Abraham S.; Friend, Albert G.; Taft, Robert A. [Sanitary Engineering Center, US Department of Health, Education and Welfare, Cincinnati, OH (United States)

1960-07-01

Increasing volumes of radioactive waste materials are being introduced into streams annually. These originate from the many laboratories in which radioactive materials are used for beneficial purposes, as well as from existing atomic energy facilities. To these amounts introduced directly into the river under essentially controlled conditions must be added those radioactive materials originating from fall-out and feeding into the stream through run-off or direct deposition. Since these same streams may serve a multiplicity of purposes, as for example, potable and industrial water, recreation, fishing, irrigation, and navigation, the effect of these discharges on each of these activities must be carefully evaluated. Present criteria do not provide a complete basis for determining permissible levels of discharge unless information is available on the amounts of specific radionuclides already present and the fate of these same nuclides in the downstream environment. Permissible levels of discharge will have to be modified in accordance with the above information and particularly in terms of the uses to which the downstream watercourse is put. Where several sources of discharge are to be permitted on a given water-course, allocation of maximum amounts of specific radionuclides must be established in accordance with downstream exposures of populations from all sources. Several suggested approaches to the handling-of this problem of waste management in relation to downstream uses are outlined and some of the difficulties associated with the application of each approach are considered. (author) [French] Chaque annee, des quantites croissantes de dechets radioactifs sont deversees dans les cours d'eau. Ces dechets proviennent des nombreux laboratoires utilisant des substances radioactives a des fins benefiques, ainsi que des installations d'energie atomique. Aux quantites qu'on deverse directement dans les cours d'eau en se conformant aux conditions qui constituent l

Bitumen coating of the radio-active sludges from the effluent treatment plant at the Marcoule centre. Review of the progress reports 1, 2, 3 and 4 (1963); Enrobage par le bitume des boues radioactives de la station de traitement des effluents du centre de Marcoule. Mise au point des etats d'avancement 1, 2, 3 et 4. (1963)

Energy Technology Data Exchange (ETDEWEB)

Rodier, J.; Lefillatre, G.; Scheidhauer, J. [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1963-07-01

dont la structure sera homogene et dont la matiere sera inerte vis-a-vis des milieux de stockage (sol, mer, etc.). Nous avons propose d'enrober ces produits radioactifs avec du bitume. Ce document a pour but de faire le point des etudes poursuivies sur cette methode. Il constitue plutot un etat d'avancement des recherches qu'une mise au point definitive. (auteurs)

Bitumen coating of the radio-active sludges from the effluent treatment plant at the Marcoule centre. Review of the progress reports 1, 2, 3 and 4 (1963); Enrobage par le bitume des boues radioactives de la station de traitement des effluents du centre de Marcoule. Mise au point des etats d'avancement 1, 2, 3 et 4. (1963)

Energy Technology Data Exchange (ETDEWEB)

Rodier, J; Lefillatre, G; Scheidhauer, J [Commissariat a l' Energie Atomique, Centre de Production de Plutonium, Marcoule (France). Centre d' Etudes Nucleaires

1963-07-01

sera homogene et dont la matiere sera inerte vis-a-vis des milieux de stockage (sol, mer, etc.). Nous avons propose d'enrober ces produits radioactifs avec du bitume. Ce document a pour but de faire le point des etudes poursuivies sur cette methode. Il constitue plutot un etat d'avancement des recherches qu'une mise au point definitive. (auteurs)

Adaptation des fiches HT des Septa électrostatiques du SPS pour les Septa du PS en vue d’utiliser le câble EPR

CERN Document Server

Prost, A

2009-01-01

Suite à de nombreux problèmes de destruction de câbles PB300b d’alimentation des Septa électrostatiques de l’accélérateur PS, il a été choisi de les remplacer par un câble de type EPR. En effet ces câbles haute tension PB300b devenus trop vieux et installés en milieu radioactif ne tiennent plus la tension nominale requise pour les Septa. De plus ceux-ci ne sont plus fabriqués dans l’industrie ce qui empêche tout échange avec un câble similaire. Le câble type EPR est basé sur une technologie plus récente et est aussi plus résistant à la radiation. Il a fait ses preuves dans le passé étant utilisé pour l’alimentation des Septa électrostatiques ZS situés sans le SPS. Étant donné que le câble PB300b 300 kV n’a pas les mêmes dimensions que le câble EPR, il a été nécessaire d’adapter une fiche compatible avec ce nouveau câble et la traversée utilisée sur les Septa électrostatiques du PS. L’ancien câble PB330b est utilisé avec de l’huile comme liquide diélectri...

Radioactive equilibrium of uranium-bearing ores in some problems of applied geology; Les equilibres radioactifs des menerais uraniferes dans quelques problemes de geologie appliquee

Energy Technology Data Exchange (ETDEWEB)

Coulomb, R; Girard, Ph; Goldsztein, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The state of equilibrium between several nuclides in radioactive relationship is determined with accuracy by the fundamental equations of radioactivity. It can be measured physically and expressed in suitable and internationally adopted units; Equilibrium - disequilibrium of uranium-bearing ores is a fairly complex phenomenon but the problem can be much simplified by well-chosen approximations in various practical field cases. The results of radiometric and radiochemical measurements lead to the interpretation of geochemical anomalies and may be used in the qualitative and quantitative estimation of uranium bearing deposits. (authors) [French] L'etat d'equilibre entre plusieurs radioelements en filiation se definit avec precision par les equations fondamentales de la radioactivite et peut etre determine par des mesures physiques dans des systemes d'unites commodes et internationalement adoptes. Le probleme general equilibre-desequilibre des minerais uraniferes est relativement complexe, mais peut se simplifier largement par des approximations judicieuses dans de nombreux cas particuliers rencontres concretement sur le terrain. Les resultats des mesures radiometriques et radiochimiques permettent l'interpretation des anomalies geochimiques et peuvent servir a l'estimation qualitative et quantitative des gisements de minerais uraniferes. (auteurs)

Biological Aspects of Disposal of Radioactive Wastes in Marine Environments; Aspects Biologiques de l'Elimination des Dechets Radioactifs dans le Milieu Marin; 0411 0418 041e 041b 041e 0413 0418 0427 0414 ; Aspectos Biologicos de la Evacuacion de Desechos Radiactivos en Medios Marinos

Energy Technology Data Exchange (ETDEWEB)

Chipman, Walter A. [United States Bureau of Commercial Fisheries (United States)

1960-07-01

Disposal of radioactive wastes in marine waters allows for an accumulation of radioactivity by marine life. Such an accumulation by seafood organisms might affect their utilization or availability. Laboratory studies of accumulation of important radionuclides present in different wastes by marine plankton, benthic invertebrates and various species of marine fish and of the biological effects of accumulated radioactivity on these forms are being conducted at Beaufort, North Carolina, as a co-operative activity of the US Atomic Energy Commission and the US Bureau of Commercial Fisheries. These investigations help provide essential information for the formulation of waste disposal practices and the safe operation of nuclear-powered ships in coastal waters. They are useful also in the development of monitoring programmes designed to detect and evaluate hazards from accidental pollution of inshore waters. (author) [French] L'elimination des dechets radioactifs dans la mer fait la part d'une accumulation d'activite dans les organismes vivant dans ce milieu. Cette accumulation dans les produits comestibles de la mer peut nuire a leur utilisation ou a leur abondance. A Beaufort (Caroline du Nord), les laboratoires du Bureau des pecheries commerciales des Etats-Unis font, en collaboration avec la Commission de l'energie atomique des Etats-Unis, des etudes sur l'accumulation de radionuclides importants provenant de differents dechets, dans le plancton marin, les invertebres benthiques et les differentes especes de poissons, ainsi que sur les effets biologiques de la radioactivite ainsi accumulee. Ces recherches permettent d'obtenir des donnees de base pour l'elaboration de methodes d'elimination des dechets et l'exploitation en toute securite des navires a propulsion nucleaire dans les eaux cotieres. Ces etudes sont egalemeut utiles pour l'etablissement de programmes de controle ayant pour objet la detection et l'evaluation des dangers que presente la pollution accidentelle

Contribution to the study of the electrostatic precipitation of aerosols; Contribution a l'etude de la precipitation electrostatique des aerosols

Energy Technology Data Exchange (ETDEWEB)

Madelaine, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires; Roure, L [Societe Bertin et Cie, 89 - Druyes Les Belles Fontaine (France)

1966-07-01

The first part is devoted to the theory of the electrostatic precipitation of ions in a cylindrical apparatus. Some aerodynamic factors influencing the quality of the flow are deduced. The second part of the report deals with the experimental verification of the hypotheses concerning the laminarity of the gas flow. The presence of a guard tube which ensures a steady state of velocity and which reduces electrical field end-effects should make it possible to obtain a better knowledge of the distribution function of the captured particles. The third part deals with the treatment of the results and with the processing method making it possible to obtain the spectral distribution of the particles captured on the electrode. (authors) [French] La premiere partie est consacree a la theorie de la precipitation electrostatique des ions dans un capteur cylindrique. Des imperatifs d'ordre aerodynamique caracterisant la qualite de l'ecoulement sont degages. La seconde partie traite de la verification experimentale des hypotheses de laminarite du courant gazeux. La presence d'un tube de garde assurant un profil stationnaire de vitesse et attenuant les effets de bouts du champ electrique, doit permettre de mieux connaitre la fonction de repartition des particules captees. La troisieme partie traite de l'exploitation des resultats et de la methode de depouillement permettant l'obtention de la repartition spectrale des particules captees sur l'electrode. (auteurs)

Contribution to the study of the biological properties of compounds labeled with radio-chromium {sup 51}Cr; Contribution a l'etude des proprietes biologiques des composes marques au radiochrome {sup 51}Cr

Energy Technology Data Exchange (ETDEWEB)

Ingrand, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-15

Among the radioisotopes commonly used in biology and medicine which are controlled Individually in the Radioelement Departement of the Saclay Nuclear Research Centre before being sent to the users, the author has chosen chromium 51 incorporated in inorganic salts or in organic substrates for a study of the biological properties of the compounds. In the first part, he has compared the pathways followed by the radioactive sodium chromate and chromic chloride mixed with blood or given to the whole animal, the object being to determine whether a reduction of hexavalent chromium occurs, both in vitro and in vivo. In the second part, the author has tried to show the validity of using, various substrates labeled with chromium 51, red cells, haemoglobin, plasma proteins and cytochrome c. The results obtained have contributed to underline the interest of using such compounds for biological applications. (author) [French] Parmi les radioisotopes d'utilisation courants en biologie et en medecine qui sont l'objet d'un controle particulier dans le Departement des Radioelements du Centre d'Etudes Nucleaires de Saclay avant leur diffusion aux utilisateurs, l'auteur a choisi le chrome 51 incorpore a des sels mineraux ou a des substrats organiques, afin d'en etudier les proprietes biologiques. Dans la premiere partie, il a compare le sort du chromate de sodium et du chlorure chromique radioactifs melanges a du sang ou administres a l'animal entier en s'efforcant de mettre en evidence une reduction du chrome hexavalent aussi bien in vitro qu'in vivo. Dans la deuxieme partie, il a cherche a etablir la validite de l'emploi de differents substrats marques au chrome 51, l'hematie, l'hemoglobine, les proteines plasmatiques et le cytochrome c. Les resultats obtenus ont permis de souligner le reel interet des applications biologiques des composes marques par le radioisotope. (auteur)

Summary of Current Geological Research in the United States of America Pertinent to Radioactive Waste Disposal on Land; Bilan des Recherches Geologiques Actuelles aux Etats-Unis, du Point de Vue de l'Elimination des Dechets Radioactifs dans le Sol; 041a 0420 0414 ; Resena de las Investigaciones Geologicas que Actualmente se Efectuan en los Estados Unidos Sobre la Evacuacion de Desechos Radiactivos en el Subsuelo

Energy Technology Data Exchange (ETDEWEB)

Simpson, E. S. [Geologist, US Geological Survey, Washington, DC (United States)

1960-07-01

'isolement qui doit etre assure aux dechets pour respecter les normes de sante et de securite generalement admises. I. Les structures assurant un isolement maximum doivent retenir pendant des siecles ou des millenaires pratiquement tous les dechets qui y sont deposes. Les recherches portent sur deux types generaux: les depots salins et les formations permeables profondes. Dans les deux cas, on procede a des experiences en laboratoire pour etudier l'interaction des dechets en solution et des matieres constituant le terrain considere; pour les depots salins, une experience sur le terrain est en cours, dans laquelle on utilise des dechets simules de. haute activite, qui, en realite, ne sont pas radioactifs. II. Les structures assurant un isolement moyen doivent ralentir notablement la mobilite des dechets pour que ceux-ci aient le temps de se desintegrer au point de vue radioactif avant de venir en contact avec l'homme ou la chaine alimentaire. Comme exemple d'isolement moyen, on peut citer l'enfouissement a faible profondeur de dechets emballes et le deversement de dechets liquides en vrac dans des couloirs d'infiltration. Des recherches sont en cours pour etudier la maniere dont se combinent le transport des radionuclides par les eaux souterraines et la retention des radionuclides fixes par sorption dans les matieres constituant le terrain. III. Les structures n'assurant aucun isolement sont celles ou les radionuclides viennent directement en contact avec l'homme ou l'un des elements vivants de la chaine alimentaire. Des recherches sont en cours a la fois pour determiner la capacite de differentes structures a recevoir de tels dechets sans que la sante et la securite en soient affectees et pour ameliorer les techniques employees a cette fin. Les recherches actuelles portent sur les points suivants : a) Classification des terrains eu egard aux problemes d'elimination des dechets; b) Etude des caracteristiques de diffusion des courants; c) Action sur la concentration de la

Technical and Administrative Considerations in the Management of Radioactive Wastes; Considerations Techniques et Administratives Relatives au Traitement des Dechets Radioactifs; 0422 0415 0425 041d 0418 0427 0415 0421 041a 0414 ; Aspectos Tecnicos y Administrativos de la Manipulacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Wolman, Abel [Johns Hopkins University, Baltimore, MD (United States); Division of Reactor Development, U.S. Atomic Energy Commission, Washington, DC (United States); Lieberman, Joseph A. [Environmental and Sanitary Engineering Branch, Division of Reactor Development, U.S. Atomic Energy Commission, Washington, DC (United States)

1960-07-01

administratifs du traitement des dechets en rattachant cette analyse aux mesures qu'il pourrait etre necessaire de prendre dans l'avenir pour assurer un traitement et un controle efficaces, sur le plan administratif et juridique, des effluents radioactifs resultant de la production d'energie atomique. Les auteurs repartissent tout d'abord en de larges categories les differentes sortes de dechets pour bien souligner que le probleme de leur traitement presente de multiples aspects et qu'on ne saurait en donner une solution unique. Ils examinent rapidement le role des differents milieux dans le choix des methodes de traitement des dechets et definissent les procedes fondamentaux de controle (dilution et dispersion, concentration et confinement). Les auteurs distinguent entre les normes fondamentales de protection radiologique et les criteres de fonctionnement qui doivent etre fixes pour realiser le controle des effluents de facon a veiller a ce que les normes fondamentales soient respectees. Les auteurs examinent les progres realises en matiere de normes et criteres ainsi que l'application de ceux-ci dans l'etablissement de reglements de sante et de securite et la mise au point de procedures administratives et juridiques. A cet egard, ils signalent les avantages que presente, du point de vue de l'opinion publique et du travail administratif, l'utilisation la plus large des textes legislatifs et des procedures administratives dans les services deja crees aux divers echelons de l'autorite. Malgre l'importance des depenses qu'entrainent le traitement et l'elimination des dechets radioactifs, le cout par unite d'energie electrique produite ne represente qu'une partie relativement restreinte du cout total par unite d'energie. Les auteurs indiquent d'autres facteurs economiques qui jouent un role dans la manipulation et l'elimination des dechets, notamment en fonction de l'emplacement de l'usine et du point d'evacuation. En outre, ils examinent d'autres aspects du traitement des dechets

Radioisotopes in sedimentology; Emploi des radioelements en sedimentologie

Energy Technology Data Exchange (ETDEWEB)

Courtois, G [CEA, Centre d' etudes Nucleaires de Saclay (France)

1967-05-15

infirmation de theses de transport, recherches des phenomenes fondamentaux de transport associees a des experiences en canaux. Apres avoir evoque les possibilites des traceurs naturels, ou dus a des retombees radioactives ou a des rejets d'effluents radioactifs, l'auteur aborde les aspects techniques de l'utilisation des traceurs artificiels: le choix du radioisotope, le marquage superficiel et massique avec mention particuliere du probleme des vases, les appareils d'immersion et de detection, les problemes de navigation et de reperage topographique . Dans la partie concernant l'exploitation des resultats, le probleme de l'obtention de resultats quantitatifs est traite et les methodes proposees decrites; l'auteur fait egalement etat des tentatives actuelles tres louables en vue de relier les tres nombreuses theories de transport de sediments aux parametres mesures sur le terrain au moyen de traceurs radioactifs. Il developpe egalement quelques aspects lies aux problemes de securite. Les methodes decrites peuvent etre egalement appliquees a des problemes voisins et fort interessants: les problemes d'erosion des sols, de stabilisation des terrains, de deplacement des dunes. Quelques indications succinctes sont donnees sur ce sujet. En conclusion, l'auteur indique aussi clairement que possible le potentiel actuel de la methode, ses limitations et les travaux souhaitables pour I'ameliorer. -Mesures en continu de la turbidite. Le transport solide en suspension etant en general beaucoup plus important que le charriage de fond, il importe de pouvoir le mesurer de facon continue; l'auteur donne quelques exemples de l'utilite d'un tel renseignement. Une telle mesure peut etre faite par des jauges decrites dans les ouvrages publies et dont on donne les principes et performances en fonction de la bibliographie connue. L'auteur donne egalement les resultats susceptibles d'etre obtenus en mesurant la turbidite par la radioactivite naturelle d'un sediment en suspension et compare les deux

Testing on air cleaning systems: Testing of the components in-place tests; Controle des installations d'epuration de l'air essais de conformite des elements: Tests in situ

Energy Technology Data Exchange (ETDEWEB)

Billard, F; Brion, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1967-07-01

The reliability of air cleaning systems is dependent on testing they are submitted to. Although in-place tests are the most important as they act as final tests upon achieved plants, component tests are necessary too. They allow detection of defective units before they are installed, partition of unit defects from mounting defects and they are more sensitive. For similar reasons, material teats are most useful. The various tests are described, about aerosol filters for one part, iodine trap for the other. The checked features are: materials nature, units sizes, efficiency, air resistance, flammability, humidity resistance, temperature resistance, adsorbent friability, etc... On iodine trapping systems, small check traps, working by-pass with the main trap are periodically subjected to efficiency test. This control allow to cut down the in-place tests frequency, particularly when poisoning from organic vapours is to be feared. (authors) [French] La surete de fonctionnement des installations d'epuratition de l'air esf fonction des controles auxquels ces installations sont soumises. Si les tests in situ sont les plus importants puisqu'ils constituent le controle final de l'installation terminee, les essais de conformite des elements constitutifs sont egalement necessaires. Ils permettent l'elimination d'elements defectueux avant leur mise en place, la discrimination des defauts du montage de ceux de l'element et sont en outre plus sensibles. De meme, le controle des materiaux constitutifs de l'element s'avere fort utile. On decrit les differents controles, d'une part, pour les fittres a aerosols, d'autre part, pour les pieges a iode. Les caracteristiques verifiees sont: nature des materiaux, dimenesions des elements, efficacite, perte de charge, resistance mecanique, inflammabilite, tenue a l'humidite, tenue a la temperature, resistance au detassement des pieges a iode, friabilite du materiau adsorbant, etc... En ce qui concerne les installations de piegeage d

Les tumeurs oncocytaires de la thyroide : a propos de 25 cas ...

African Journals Online (AJOL)

Conclusion : Les tumeurs oncocytaires de la thyroïde sont reconnues à la lumière des travaux récents comme une entité anatomo-clinique particulière, se différenciant des tumeurs vésiculaires (auxquelles elles ont été longtemps assimilées) par une évolution plus péjorative et par une insensibilité à l'iode radioactif avec ...

Global Observations of Aerosols and Clouds from Combined Lidar and Passive Instruments to Improve Radiation Budget and Climate Studies

Science.gov (United States)

Winker, David M.

1999-01-01

Current uncertainties in the effects of clouds and aerosols on the Earth radiation budget limit our understanding of the climate system and the potential for global climate change. Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations - Climatologie Etendue des Nuages et des Aerosols (PICASSO-CENA) is a recently approved satellite mission within NASA's Earth System Science Pathfinder (ESSP) program which will address these uncertainties with a unique suite of active and passive instruments. The Lidar In-space Technology Experiment (LITE) demonstrated the potential benefits of space lidar for studies of clouds and aerosols. PICASSO-CENA builds on this experience with a payload consisting of a two-wavelength polarization-sensitive lidar, an oxygen A-band spectrometer (ABS), an imaging infrared radiometer (IIR), and a wide field camera (WFC). Data from these instruments will be used to measure the vertical distributions of aerosols and clouds in the atmosphere, as well as optical and physical properties of aerosols and clouds which influence the Earth radiation budget. PICASSO-CENA will be flown in formation with the PM satellite of the NASA Earth Observing System (EOS) to provide a comprehensive suite of coincident measurements of atmospheric state, aerosol and cloud optical properties, and radiative fluxes. The mission will address critical uncertainties iin the direct radiative forcing of aerosols and clouds as well as aerosol influences on cloud radiative properties and cloud-climate radiation feedbacks. PICASSO-CENA is planned for a three year mission, with a launch in early 2003. PICASSO-CENA is being developed within the framework of a collaboration between NASA and CNES.

Case series

African Journals Online (AJOL)

abp

6 mai 2016 ... during the anatomopathological exam, giving us a 3.38% prevalence. The average age of ... basedowifié, et 1 cas de maladie de basedow. L'âge moyen des ... papillaire. Un traitement par l'iode radioactif a été indiqué chez 5.

Management of Waste from the Use of Radioisotopes; Divers Aspects Resultant de l'Utilisation des Isotopes Radioactifs; 0423 0414 0410 041b 0415 041d 0418 0415 041e 0422 0425 041e 0414 ; Diversos Aspectos Relacionados con los Desechos Procedentes del Empleo de Radioisotopos

Energy Technology Data Exchange (ETDEWEB)

Rogers, Lester R. [Radiation Safety Branch, Division of Licensing and Regulation, United States Atomic Energy Commission (United States)

1960-07-01

The author examines the origin and nature of radioactive waste generated in the use of radioisotopes in industry, medicine, agriculture and research and studies the relationship between types, quantities and uses of radioisotopes and disposal of the radioactive waste generated in their use. He also discusses the methods used for the disposal of such waste under the licensing controls of the United States Atomic Energy Commission. These methods include: 1. The controlled discharge of low concentrations of effluents into streams and into the atmosphere; 2. Controlled release of small quantities of soluble or readily dispersible waste products into sanitary sewage systems; 3. Burial, under controlled conditions, of small quantities of waste in the soil ; 4. Return to AEC installations of radioactive waste for storage or land burial ; 5. Treatment by incineration; and 6. Disposal of packaged waste at sea. The paper reviews the criteria and regulatory requirements applicable to cach method of disposal to accomplish the objective of preventing the waste from entering the food chain of man in hazardous quantities, or of adversely affecting the use of the environment by man. It goes on to discuss the limitations on the types, quantities, and methods of disposal for which private concerns can be licensed due to long-term responsibility for maintenance of burial grounds or storage facilities. (author) [French] L'auteur se propose d'examiner l'origine et la nature des dechets radioactifs resultant de l'utflisation des radioisotopes dans l'industrie, la medecine, l'agriculture et dans les laboratoires de recherche, et d'etudier les rapports qui existent entre les types, les quantites et les utilisations des radioisotopes, d'une part, et les dechets de leur production, d'autre part. Il etudie aussi les methodes utilisees pour l'elimination de ces dechets conformement aux mesures de controle appliquees par la Commission de l'energie atomique des Etats-Unis. Les methodes

Contributions of Geology to the Problem of Radioactive Waste Disposal; Contributions de la Geologie au Probleme de l'Elimination des Dechets Radioactifs; 0412 041a 041b 0410 0414 0413 0415 041e 0414 ; Contribucion de la Geologia a la Resolucion de los Problemas que Plantea la Evacuacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Nace, R. L. [Water Resources Division, Geological Survey, Washington 25, DC (United States)

1960-07-01

aimed directly at waste disposal problems. (author) [French] La terre est l'objet des etudes geologiques; or, les dechets radioactifs ne peuvent etre disperses ou entreposes que dans ou sur la terre. En ce sens, les problemes relatifs a l'elimination des dechets radioactifs sont avant tout d'ordre geologique. Les Etats-Unis ont applique largement les connaissances geologiques accumulees et certains principes bien etablis aux problemes de l'elimination; le caractere exceptionnel de ces problemes a necessite des recherches qui ont permis d'approfondir considerablement nos connaissances dans des domaines particuliers de la geologie. De nombreux travaux ont porte sur l'etude d'emplacements pour installations nucleaires. Cette etude comporte l'analyse et l'evaluation de facteurs geologiques, topographiques, hydrologiques, geochimiques et sismiques. On a analyse aussi par region les caracteristiques d'ensemble des grandes divisions naturelles des Etats-Unis et les incidences de ces caracteristiques sur l'entreposage et l'elimination des dechets. Parmi les problemes speciaux, on etudie comment se comportent ou pourraient se comporter des dechets ordinaires dans des milieux geologiques determines. D'autres etudes portent sur l'utilisation eventuelle de cavites syncli- nales, de failles stratigraphiques, de bancs de sel et de domes de sel pour l'entreposage et l'isolement des dechets de haute activite. De nombreuses etudes generales et quelques etudes de detail ont ete entreprises sur la radiometrie du milieu ambiant. L'eau naturelle est le facteur critique dans l'elimination des dechets ; on a donc etudie certains processus naturels par lesquels on peut purifier l'eau ou en modifier la composition chimique. Les etudes consacrees aux problemes suivants ont donne des resultats interessants : processus de dispersion et de diffusion dans les eaux souterraines et dans les eaux de surface ; vitesse de circulation des contaminants dans les cours d'eau ; mecanisme d'ecoulement des eaux

Investigations on the chemical composition of the organic fraction of tropospheric aerosols. Final report; Untersuchungen zur chemischen Zusammensetzung der organischen Komponente des troposphaerischen Aerosols. AFS-Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Hoffmann, T.; Warscheid, B.

2000-07-01

] Obwohl das Wissen um die Bedeutung von luftgetragenen Partikeln fuer die Strahlungsbilanz der Atmosphaere in den letzten Jahren zugenommen hat, sind eine Reihe von wichtigen Aerosolbildungsmechanismen bisher nur unzureichend untersucht worden. Dies gilt insbesondere fuer Aerosole, die aus fluechtigen organischen Vorlaeufern natuerlichen wie auch antrophogenen Ursprungs im Verlauf von troposphaerischen Oxidationsprozessen gebildet werden. Das Vorhaben umfasste daher die Entwicklung massenspektrometrischer Methoden fuer qualitative wie auch fuer quantitative Studien zur chemischen Zusammensetzung von sekundaeren organischen Aerosolen (SOA), insbesondere gebildet aus der Ozonolyse von Monoterpenen (z.B. {alpha}-Pinen, {beta}-Pinen, Sabinen, {delta}{sup 3}-Caren, Limonen). Mit Hilfe eines entwickelten On-line APCI-ITMS-Systems (atmospheric pressure chemical ionisation, APCI) konnte die Bildung von Gas- und Partikelphasenprodukten in Echtzeit (Zeitaufloesung {proportional_to}1 s) als Folge der Monoterpen-Ozonolyse beobachtet werden. Die Nachweisgrenze der Methode liegt bei ca. 100 ppt(v/v) im positiven Ionenmodus. Basierend auf der Entwicklung geeigneter Standardadditionsmethoden erfolgte auch die unmittelbare Quantifizierung ausgewaehlter Oxidationsprodukte in der Gas- und Partikelphase. Mittels isotopenmarkiertem Wasser (H{sub 2}{sup 18}O) wurden darueber hinaus einige zugrundeliegende Reaktionsmechanismen aufgedeckt. Ein weiterer Teil des Projektes konzentrierte sich auf die Charakterisierung insbesondere der schwerfluechtigen Aerosolkomponenten der Monoterpen-Ozonolyse mittels MS/MS-Studien. Diese Studien ergaben, dass eine Reihe von multifunktionellen Carbonsaeureprodukte signifikante Aerosolbestandteile repraesentieren (Dicarbonsaeuren, Oxocarbonsaeuren, Hydroxycarbonsaeuren etc.). Schliesslich ergaben die massenspektrometrischen Untersuchungen deutliche Hinweise auf starke intermolekulare Wechselwirkungen zwischen den einzelnen Produkten (Assoziatbildung). Da ausserdem

Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits; Contribution a la connaissance geochimique des familles uranium-radium et du thorium dans les Vosges meridionales. Application de certains resultats en prospection des gisements d'uranium

Energy Technology Data Exchange (ETDEWEB)

Jurain, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [French] L'etude presentee ici a pour but de conduire a une connaissance plus precise de la geochimie des familles Uranium-Radium et Thorium dans les Vosges meridionales et d'appliquer certains resultats a la prospection des gites uraniferes. Il a ete mis en evidence: une liaison Calcium-Magnesium et Uranium-Thorium dans des granites calco-alcalins. Les mineraux hotes de l'Uranium et du Thorium sont: la hornblende, la biotite, le sphene, l'epidote. une concentration actuelle de l'Uranium en desequilibre seculaire dans une zone thermale ou les mineralisations satellites constituent une paragenese epithermale. un desequilibre de la famille Uranium-Radium dans des mineraux supergenes du plomb (phosphates et vanadates) prouvant les circulations actuelles de l'Uranium. une liaison entre la teneur en Radon des eaux de sources et celle en Uranium-Radium des roches. Une telle liaison permet de realiser une methode de prospection fondee sur le dosage du gaz radioactif des eaux de sources froides d'une region quelconque

Contribution to the geochemical knowledge of the uranium-radium and thorium families in the southern Vosges. Applications of some results in the prospecting of uranium deposits; Contribution a la connaissance geochimique des familles uranium-radium et du thorium dans les Vosges meridionales. Application de certains resultats en prospection des gisements d'uranium

Energy Technology Data Exchange (ETDEWEB)

Jurain, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

This work's aim is to lead to a more accurate knowledge of the geochemistry of the Uranium-Radium and Thorium families in the Southern Vosges and to apply some of the results to the prospecting of uraniferous deposits: It has been showed: a bond between Calcium-Magnesium and Uranium-Thorium in the calco-alkaline granites. The host minerals of Uranium and Thorium are hornblende, biotite, titanite and epidote. a concentration of Uranium, at present time with secular disequilibrium in a thermal zone where the satellite mineralizations form an epithermal paragenesis. a disequilibrium of the Uranium-Radium family in the supergene minerals of the lead (phosphate and vanadate) showing the present circulations of Uranium. a bond between the radon grade of the spring waters and Uranium-Radium of the rocks. Such a relation allow to realize a prospecting method based on the determination of radioactive gases from the cold spring-waters of a common country. (author) [French] L'etude presentee ici a pour but de conduire a une connaissance plus precise de la geochimie des familles Uranium-Radium et Thorium dans les Vosges meridionales et d'appliquer certains resultats a la prospection des gites uraniferes. Il a ete mis en evidence: une liaison Calcium-Magnesium et Uranium-Thorium dans des granites calco-alcalins. Les mineraux hotes de l'Uranium et du Thorium sont: la hornblende, la biotite, le sphene, l'epidote. une concentration actuelle de l'Uranium en desequilibre seculaire dans une zone thermale ou les mineralisations satellites constituent une paragenese epithermale. un desequilibre de la famille Uranium-Radium dans des mineraux supergenes du plomb (phosphates et vanadates) prouvant les circulations actuelles de l'Uranium. une liaison entre la teneur en Radon des eaux de sources et celle en Uranium-Radium des roches. Une telle liaison permet de realiser une methode de prospection fondee sur le dosage du gaz radioactif des eaux de sources

The Hydrographical Features of the Baltic Sea and the Disposal of Radioactive Wastes; L'Hydrographie de la Mer Baltique et l'Evacuation des Dechets Radioactifs; 0413 0418 0414 0420 041e 0413 0420 0414 ; Caracteristicas Hidrograficas del Mar Baltico en Relacion con la Evacuacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Hela, Ilmo [Institute of Marine Research Helsinki (Finland)

1960-07-01

The purpose of the paper is to point out a few hydrographical features of the Baltic Sea, which make this sea, in reference to the disposal of radioactive wastes, different from any oceanic region. The seas can be divided, in reference to the practical problem of the disposal of radionuclides, into the following zones: (1) harbours, (2) fairways leading into harbours, (3) outer continental shelf and (4) the open sea. There, is no open sea, in the above sense, in the Baltic Sea. In addition, the validity of the rules recommended for the above zones, must be carefully checked through further hydrographical studies, since: (1) the whole Baltic is, in a sense, an estuary, with a sill-depth of only 18 metres in the Danish Sounds, (2) the mixing in the Baltic Sea is much more restricted than in the oceans, since the Baltic is rich in islands, brackish, heavily stratified, practically tideless, in winter partly covered with ice, and has a limited fetch of wind and only slowly moving permanent currents. In the paper reference is made to all these factors which diminish the turbulent diffusion, both vertical and horizontal. For the evaluation of the advection and turbulent (eddy) diffusion, both in the upper water layers and at the bottom, synoptic observations of current velocity and salinity at a number of points in several regions of the Baltic Sea and under different weather conditions are needed. (author) [French] Le memoire a pour but d'exposer certains traits de l'hydrographie de la mer Baltique qui, du point de vue de l'evacuation des dechets radioactifs, la distinguent de toute region oceanique. Pour l'etude des problemes pratiques poses par l'evacuation des dechets radioactifs, on peut repartir la mer en quatre zones: 1) les ports, 2) les chenaux d'acces aux ports, 3) le plateau continental, 4) la haute mer. Dans ce sens, il n'y a pas de haute mer dans la Baltique. En outre, la validite des reglements recommandes pour les zones precitees doit faire l'objet d

The Effect of Fission Products on the Radioactivity of some Hydrobionts of the Pacific Ocean; Effet des Produits de Fission sur la Radioactivite de Certains Organismes Marins de l'Ocean Pacifique; 0412 041b 0418 0414 ; Influencia de los Productos de Fision en la Radiactividad de Algunos Organismos Marinos del Oceano Pacifico

Energy Technology Data Exchange (ETDEWEB)

Moiseev, P. A.; Kardashev, A. V. [All-Union Marine Fisheries and Oceanographical Scientific Research Institute, Moscow, USSR (Russian Federation)

1960-07-01

The paper emphasizes the fact that currents in the water masses disperse radioactive elements over large distances, with the result that many marine fauna and flora far removed from the centres of contamination may accumulate dangerous concentrations of such elements. (author) [French] Dans ce memoire, on souligne que les masses d'eau des courants marins transportent les elements radioactifs a de grandes distances; il s'ensuit que de nombreux animaux et vegetaux marins vivant loin des foyers de contamination peuvent accumuler ces elements jusqu'a des concentrations dangereuses. (author) [Spanish] En el informe se pone de manifiesto que las corrientes de agua transportan elementos radiactivos a grandes distancias, por lo cual muchos animales y vegetales marinos, que habiten lejos de los focos de contaminacion, pueden acumular estos elementos en concentraciones peligrosas. (author) [Russian] V doklade podcherkivaetsja, chto vodnye massy raznosjat techenijami radioaktivnye jelementy na bol'shie rasstojanija, v rezul'tate chego mnogie morskie zhivotnye i rastenija, obitajushhie daleko ot ochagov zarazhenija, mogut nakaplivat' ztj jelementy do opasnyh koncentracij. (author)

The Public Health Problems of Nuclear Waste Disposal; L'Elimination des Dechets Radioactifs et la Sante Publique; 041f 0420 041e 0414 ; Problemas que Presenta para la Salud Publica la Evacuacion de Desechos Radiactivos

Energy Technology Data Exchange (ETDEWEB)

Dunster, H. J. [United Kingdom Atomic Energy Authority, Health and Safety Branch (United Kingdom)

1960-07-01

The fundamental bases of the control of public health problems in connexion with the disposal of radioactive wastes are the Recommendations of the International Commission on Radiological Protection. These Recommendations cannot be applied directly to the disposal of waste because the released radioactivity rarely reaches man in a direct manner. The setting of maximum permissible discharge rates, therefore, involves a knowledge not only of man's utilization of his environment but also of the diverse processes which govern the behaviour of radioactive materials in that environment. As an example of the way in which the United Kingdom has dealt with these problems the paper discusses the discharge of low-activity liquid wastes into the sea, and refers briefly to the similar problems of assessing discharges into rivers and disposal into the ground or the deep sea. The paper concludes that it is possible to demonstrate without difficulty the safety of most proposed waste-disposal operations but that meticulous investigation and control are necessary whenever substantial amounts of radioactivity are to be released to man's environment. (author) [French] Les donnees de base relatives aux mesure de sante publique touchant l'elimination des dechets radioactifs sont fournies par les recommandations de la Commission internationale de protection radiologique. Mais ces recommandations ne peuvent pas etre directement appliquees a l'elimination des dechets, car il est rare que l'homme se trouve directement expose aux radiations emises. Pour pouvoir fixer, en matiere d'elimination de dechets, un taux maximum admissible, il faut donc connaitre non seulement le comportement de l'homme dans le milieu considere, mais aussi les processus suivant lesquels les matieres radioactives agissent sur ce milieu. Prenant comme exemple ce qui est fait au Royaume-Uni, l'auteur etudie la question de l'evacuation dans la mer de dechets liquides de faible radioactivite et il donne un apercu des

The processing and management of wastes from atomic reactors; Nouvelles installations industrielles du C.E.A. pour le traitement des dechets radioactifs liquides et solides

Energy Technology Data Exchange (ETDEWEB)

Cerre, P; Mestre, E; Bourdrez, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The policy concerning radioactive wastes studied by all Atomic Centres has led to various procedures which, while apparently numerous, come under a few standard headings. Whether the wastes are in the liquid or solid state their management depends on their physical and chemical nature. The procedure adopted is governed by three general principles: - determination of the most economical means possible of storage and processing by volume reduction; - conversion to a solid compact form; - complete acceptance of the accepted standards at all places and all times. In this communication all the standard solutions adopted and used by the various Centres of the Commissariat a l'Energie Atomique will be examined bearing in mind the preceding remarks. Particular mention will be made of the following: - For liquids, physical, chemical and physico-chemical processing - For solids, decontamination, volume reduction and long-term conditioning techniques. The different procedures for collecting and storing solid wastes before and after processing are also discussed. The paper ends with a brief review of the studies, both technical and economic, being pursued on this subject. (authors) [French] La gestion des dechets etudies par tous les Centres Atomiques a donne lieu a des solutions qui - bien que nombreuses en apparence - se ramenent a quelques solutions types, peu nombreuses. Qu'il s'agisse de dechets solides ou liquides, la nature physique et chimique des dechets conditionne leur mode de gestion. Celle-ci procede de trois principes generaux: - recherche du mode de stockage et de traitement aussi economique que possible par reduction de volume; - mise sous forme compacte solide; - garantie du respect des normes en tous lieux et en tous temps. Dans cette communication, nous examinons toutes les solutions types, compte tenu des remarques precedentes, qui ont ete adoptees et sont utilisees par les differents Centres du Commissariat a l'Energie Atomique. Nous rappelons en

The choice of sites considered with respect to problems of radioactive waste disposal; Le choix des sites considere dans ses rapports avec les problemes de rejets d'effluents radioactifs

Energy Technology Data Exchange (ETDEWEB)

Duhamel, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The author of this article shows clearly that a knowledge of the behaviour of wastes together with an analysis of the risks of accidents makes it possible to define the general characteristics of a site as a function of, on the one hand the geological and meteorological factors, and on the other, the proposed installations. Consideration of the biological environment makes it possible to clarify the sitological study and to make a choice between the several sites possible. The author shows the real necessity for radio-protection specialists to share their knowledge, to establish regulations, and to cooperate with the authors responsible for the installations, from the moment of the choice of the site and of the planning of the apparatus up to the final reject of the waste. (author) [French] L'auteur de ce rapport montre clairement que la connaissance du comportement des effluents jointe a l'analyse des risques d'accident permettent de degager les caracteristiques generales d'un site en fonction d'une part, des donnees geologiques et meteorologiques, d'autre part des installations projetees. La consideration du milieu biologique permet de preciser l'etude sitologique et d'effectuer un choix entre plusieurs sites donnes. L'auteur met en evidence la necessite absolue pour les specialistes de la radioprotection d'echanger leurs connaissances, d'etablir des reglements et de cooperer avec les autorites responsables des installations depuis le choix des sites et le projet des appareillages jusqu'au rejet ultime des residus. (auteur)

From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour; Du couplage des techniques d'analyse par faisceaux d'ions et des methodes de caracterisation physico-chimique a l'etude des effets d'irradiation sur le comportement des materiaux

Energy Technology Data Exchange (ETDEWEB)

Millard-Pinard, N

2003-07-01

The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is dedicated to this study

Detection of radioactive gases in the CO{sub 2} cooling the reactors G 2 - G 3; Detection des gaz radioactifs dans le CO{sub 2} de refroidissement des piles G2 - G3

Energy Technology Data Exchange (ETDEWEB)

Pouthier, J; Rossi, J [Commissariat a l' Energie Atomique, Chusclan (France). Centre de Production de Plutonium de Marcoule

1968-07-01

The carbon dioxide cooling the reactors G2 - G3 contains activation gases and fission gases. It is of interest to know their concentration, for example to be able to deduce rapidly the norms which would have to be applied in the case of an incident in the circuit. Gas-phase chromatography is applied daily for carrying out analyses. The chromatogram has separate peaks due to tritium, argon 41, krypton 85 and the 133 and 135 isotopes of xenon. By integrating each peak it is possible to calculate the specific activity of each product. The construction of an apparatus for carrying out continuous measurements is under consideration. (authors) [French] Le gaz carbonique, refroidissant les reacteurs G2 - G3, contient des gaz d'activation et des gaz de fission. Il est interessant de connaitre leur teneur par exemple pour etre en mesure de deduire rapidement les normes qu'il y aurait lieu d'appliquer en cas d'incidents sur le circuit. La methode de chromatographie en phase gazeuse est employee quotidiennement pour faire des analyses. Le chromatogramme se presente sous forme de pics distincts dus au tritium, a l'argon 41, au krypton 85 et aux isotopes 133 et 135 du xenon. L'integration de chaque pic permet de calculer l'activite specifique de chaque compose. Il est envisage de construire un appareil pour des mesures en continu. (auteurs)

The use of radioactive sources for the study of wear in refractory linings; L'emploi de sources radioactives pour l'etude de l'usure des revetements refractaires

Energy Technology Data Exchange (ETDEWEB)

Courtois, G; Hours, R [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

Following a discussion on the radioactive method for studying wear in refractory linings (description of the method, advantages and disadvantages, choice of radioactive indicator and detection), the article deals in some detail with the problems of safety involved in this technique. The two most important points discussed are: 1- the need to fix an upper limit of activity in the cast iron: the authors propose a figure of 1 mc of cobalt 60 in 500 tons; 2- the precautions necessary to remedy the diffusion of cobalt 60 in the brickwork (development of special pyro-ceramic sources). After a discussion on the international view point regarding the use of the method, a brief outline of some French projects is given, with particular reference to the case of a blast furnace. A note from the Commission interministerielle des Radioelements is given as an appendix; this deals with special conditions laid down for the use of radioelements in the determination of wear in refractory walls. (author) [French] Apres avoir discute de la methode radioactive pour l'etude de l'usure des revetements refractaires (description de la methode, avantages et inconvenients, choix de l'indicateur radioactif et detection), l'article traite plus particulierement des problemes de securite intervenant dans cette application. Les deux points les plus importants discutes dans ce rapport sont: 1- la necessite de fixer l'activite limite de la fonte et les auteurs proposent ici le chiffre de 1 mc de cobalt 60 dans 500 tonnes de fonte; 2- les remedes a apporter a la diffusion du cobalt 60 dans la maconnerie (realisation de sources speciales en pyrocerame). Apres avoir examine le point de vue international sur l'utilisation de la methode, l'article decrit brievement quelques realisations francaises en etudiant plus particulierement le cas d'un haut-fourneau. En annexe, se trouve une note de la Commission interministerielle des Radio-elements traitant des conditions particulieres d'emploi des radio

Determination of the exchange capacity of soils using radio-strontium; Determination de la capacite d'echange des sols au moyen du radio-strontium

Energy Technology Data Exchange (ETDEWEB)

Grauby, A; Saas, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

In order to improve the technique and in particular to reduce the time required for measuring the exchange capacity of soils, the authors have developed a rapid measurement method based on the use of radio-active tracers. The element chosen for showing the occurrence of exchangeable bases is radio-strontium; it can displace the ions Ca{sup ++}, Mg{sup ++}, Na{sup ++}, K{sup +} from the soil. The use of a de-sorbent, barium chloride, makes it possible to recover the strontium fixed. A comparison of the results obtained using the two methods appears to be very satisfactory. The conventional method requires from 1 1/2 to 2 days - the radio-strontium method requires only 3 hours with the possibility also of carrying out large series of measurements. (authors) [French] Pour ameliorer la technique et surtout reduire le temps de manipulation que necessite la mesure de la capacite d'echange des sols, les auteurs ont mis au point une methode de mesure rapide qui fait appel aux traceurs radioactifs. C'est le radio-strontium qui a ete choisi pour la mise en evidence des bases echangeables. Il permet de deplacer les ions Ca{sup ++}, Mg{sup ++}, Na{sup ++}, K{sup +} du sol. Un desorbant, le chlorure de baryum, permet de recuperer la quantite du strontium fixe. La comparaison des resultats obtenus par les deux methodes semble tres satisfaisante. La methode classique necessite 1 jour et demi a 2 jours - la methode radiostrontium exige seulement 3 heures avec la possibilite de grandes series. (auteurs)

From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour; Du couplage des techniques d'analyse par faisceaux d'ions et des methodes de caracterisation physico-chimique a l'etude des effets d'irradiation sur le comportement des materiaux

Energy Technology Data Exchange (ETDEWEB)

Millard-Pinard, N

2003-07-01

The general purpose of my research work is to follow and to interpret the surface evolution of materials, which have received several treatments. During my PhD and my post-doc work, my field of research was tribology. Since I arrived in the 'Aval du Cycle Electronucleaire' group of the Institut de Physique Nucleaire de Lyon, my research activities are in line with the CNRS program 'PACE ' (Programme sur l'Aval du Cycle Electronucleaire) within the ACTINET network. They are coordinated by the PARIS (Physico-chimie des actinides et autres radioelements en solution et aux interfaces) and NOMADE (NOuveaux MAteriaux pour les DEchets) GDR with ANDRA (Agence Nationale pour la gestion des Dechets RAdioactifs), EDF and IRSN (Institut de Radioprotection et de Surete Nucleaire) as partner organisations. My work focused on the study of fission products and actinides migration in barrier materials, which may be capable of assuring the long term safety of deep geological repositories. Until now, it was necessary to use the coupling of ion beam analysis techniques and physico-chemical characterization techniques. During the last few months, I have became interested in understanding radiolytic effects. This new orientation has led us to use ion beams as an irradiating tool. These irradiation experiments are pursued in three major projects. The study of cobalt sulfide inhibition effects of radiolysis gas production during the irradiation of model organic molecules. This is a collaboration with the IRSN, the Institut de Recherche sur la Catalyse and the Ecole Nationale Superieure des Mines de Saint-Etienne. A PhD, co-directed by M. Pijolat from ENSMSE and myself, concerning this study will start in October 2003. Water radiolysis effects on iron corrosion are also studied in the particular case of vitrified nuclear waste containers, which will be stored in deep geological repositories. One ANDRA financed PhD, co-directed by Nathalie Moncoffre and myself, is

The fate of chylomicron cholesterol in the rat. 1. research into the storing of chylomicrons (1961); Destinee du cholesterol des chylomicrons chez le rat. 1. recherches sur le stockage des chylomicrons (1961)

Energy Technology Data Exchange (ETDEWEB)

Chevallier, F; Maurice, J P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

Rats conditioned to take their dally meal between midnight and 2 a.m. are given at midnight, by stomach tubing, 0,5 mg 4-{sup 14}C-cholesterol, and are sacrificed in the following hours. During the most active phase of intestinal absorption, specific radioactivities of free and esterified liver cholesterol and of serum cholesterol are practically equal. Consequently, captation of absorbed cholesterol by the liver is not detectable. The results obtained exclude, on the other hand, the possibility that the lungs might play a similar role. The problem of the fate of chylomicron cholesterol is discussed. In order to avoid any ambiguity in this discussion, we have determined the concentration and specific radioactivity of free and esterified cholesterol in chylomicrons and lymph obtained by continuous drainage of chyle. 5 p. 100 of the radioactive cholesterol of chyle are found in lymph: in chylomicrons, the radioactivity of free cholesterol is higher than that of esterified cholesterol. (authors) [French] Des rats, conditionnes a ingerer leur repas quotidien entre minuit et 2 heures, recoivent a minuit, par tubage gastrique 0,5 mg de cholesterol 4-C{sup 14} et sont sacrifies dans les heures qui suivent. Pendant la phase la plus active de l'absorption intestinale les valeurs des radioactivites specifiques du cholesterol libre et esterifie du foie, et du cholesterol du serum sont pratiquement egales. En consequence, la captation par le foie du cholesterol d'absorption n'est pas decelable. Les resultats obtenus permettent, par contre, d'exclure la possibilite pour les poumons de jouer un role analogue. Le probleme de la destinee du cholesterol des chylomicrons est discute. Pour ecarter toute ambiguite dans cette discussion, on a determine la concentration et la radioactivite specifique du cholesterol libre et esterifie dans les chylomicrons et la lymphe obtenus par le drainage continu du chyle. 5 p. 100 du cholesterol radioactif du chyle se trouve dans la lymphe; dans les

Influence of Aerosol Properties and the Respiratory Pattern upon Hazards Evaluation following Inhalation Exposure; Influence des Caracteristiques des Aerosols et du Regime de la Respiration sur l'Evaluation des Risques, a la Suite d'une Exposition par Inhalation; Vliyanie svojstv aehrozolej i obraztsa respiratora na otsenku opasnosti oblucheniya pri vdykhanii radioaktivnykh veshchestv; Influencia de las Propriedades de los Aerosoles y de su Esquema Repiratorio en la Evaluacion de los Riesgos Consecutivos a una Exposicion por Inhalacion

Energy Technology Data Exchange (ETDEWEB)

Thomas, R. G. [Lovelace Foundation for Medical Education and Research, Albuquerque, NM (United States)

1964-10-15

There are three important biological parameters which are necessary in evaluating the hazards from compounds entering the body by any route. These are (1) the amount deposited in-the body; (2) the distribution and translocation kinetics within the body; and (3) the rate of excretion of the material. Sufficient quantitative data on these points are generally lacking in the case of an accidental exposure. This paper deals with experimental animal studies correlating different physical and chemical characteristics of inhaled particles with the three biological variables mentioned above. Values for the amount and location of deposited material as a function of the particle size inhaled is presented for a tissue soluble compound (caesium chloride) and for a tissue ''insoluble'' compound (thorium chloride). Evidence is also given to substantiate the variations which occur in tissue distribution and excretion of an element, depending upon its physical and chemical state when breathed. Data from experiments with aerosols of many compounds, including those already mentioned, is used to show a unique correlation between body burden and faecal excretion during the first few post-exposure days. The advantages in performing analyses on both urine and faeces for bioassay purposes is demonstrated. The fallacies in current methods of practical hazard assessment from air sampling and bioassay techniques are stressed throughout, using the above data as examples. (author) [French] Pour evaluer les risques dus aux composes qui penetrent dans l'organisme par une voie quelconque, il faut tenir compte de trois parametres biologiques importants: 1. Quantite deposee dans l'organisme; 2. Cinetique de la repartition et de la translocation a l'interieur de l'organisme; 3. Vitesse de l'excretion de la matiere consideree. Dans le cas d'une exposition accidentelle, on manque generalement de donnees quantitatives suffisantes sur ces parametres. Le memoire a trait a des etudes experimentales qui

Effects of DTPA aerosol on lung contamination by lanthanum; Influence du DTPA en aerosol sur les contaminations pulmonaires au lanthane

Energy Technology Data Exchange (ETDEWEB)

Pasquier, C; Voisin, D; Thieblement, P; Perrault, G; Bayard, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

Applying DTPA aerosol for the treatment of lung contamination by lanthanum we were able to determine its effectiveness as a function of time. Provided it was administered early during the two hours after exposure, over 50 per cent could be removed using lower therapeutic doses than those prescribed for other routes of administration. Its association with some enzymes did not enhance the chelator therapeutic effect. We also calculated the constant of passage of lanthanum through the alveolar wall and found a value of 0.016 mn{sup -1}. Finally, as we have discovered a large part cannot be mobilized by DTPA, we shall now study the physico-chemical mechanisms involved in this protection. (authors) [French] L'emploi du DTPA en aerosol dans le traitement des contaminations pulmonaires par le lanthane, nous a permis d'etablir et d'evaluer son efficacite en fonction du temps. A condition d'etre utilise precocement, dans les deux heures qui suivent la contamination, une fraction superieure a 50 pour cent peut etre eliminee et ceci avec des doses therapeutiques inferieures a celles preconisees pour les autres voies d'administration. L'association avec quelques autres enzymes n'a pas permis d'ameliorer l'effet therapeutique de ce chelateur. Nous avons egalement chiffre la constante de passage du lanthane a travers la barriere alveolaire dont la valeur est de l'ordre de 0.016 mn{sup -1} Enfin, la decouverte d'une importante partie non piegeable par le DTPA nous amene maintenant a etudier les mecanismes physico-chimiques de cette protection. (auteurs)

NET.EXCEL - a European thematic network for suggesting and prioritising future joint R and D projects

International Nuclear Information System (INIS)

Svemar, C.; Brewitz, W.

2004-01-01

The NET.EXCEL project concerns the forming of a network of European end users for analysing the present status and future needs in research, technical development and demonstration (RTD) for the disposal of highly radioactive waste in the three classical rock media: salt, clay/clay sediments and crystalline rock. The aim is to generate values additional to that gained by the individual participants: Svensk Kaernbraenslehantering AB (Sweden), Posiva Oy (Finland), Empresa Nacional de Residuos Radioactivos SA (Spain), Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (Germany), Agence nationale pour la gestion des dechets radioactifs (France), Nationale Genossenschaft fuer die Lagerung radioaktiver Abfaelle (Swizerland), Organisme National des Dechets Radioactifs et des Matieres Fissiles Enrichies (Belgium) and United Kingdom Nirex Limited (UK). The practical way to carry out the needed RTD-activities and the principles behind the process to establish priorities for the necessary RTD-work is quite similar among the participants. Common ground has been analysed for the role/responsibilities of the participating organisations, for the establishment of priorities for the RTD work and for the modus operandi of the organisations to carry out the RTD. The issue of prioritising the potential RTD activities and the factors taken into account by the participating organisations have been summarised and analysed with respect to the common denominator in the project. (orig.)

New results concerning the behaviour of fission gases in in-pile UO{sub 2} at high temperatures; Resultats nouveaux sur le comportement des gaz de fission a haute temperature dans l'UO{sub 2} en pile

Energy Technology Data Exchange (ETDEWEB)

Soulhier, R; Schurenkamper, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1964-07-01

The authors consider in the first part the various phenomena giving rise to the production of fission gases towards the exterior of nuclear fuels. The following aspects are dealt with: diffusion, for which is considered the influence of the predecessors of the radioactive gases, the fission recoil, atom expulsion along the fission paths and the evaporation. In the second part the authors present the results obtained on UO{sub 2} samples subjected to irradiation at temperatures of between 150 and 2000 deg C: - At low temperatures the variation of the amount produced as a function of the half-life of the isotopes studied shows that recoil is hot the only cause of gas production. - Above 1800 deg C, a weight loss by evaporation has been observed and the influence of this phenomenon on gas liberation has been studied; thus the fraction of {sup 135}Xe liberated at 2000 deg C by processes other than evaporation is of the order of 10 per cent. - The influence of the various mechanism on the overall effect as a function of temperature is discussed. (authors) [French] Dans une premiere partie, les auteurs etudient les differents phenomenes pouvant donner lieu au degagement des gaz de fission hors d'un combustible. Sont traites successivement: la diffusion, pour laquelle on discute l'influence des predecesseurs des gaz radioactifs, le recul de fission, l'expulsion des atomes le long des trajets de fission et l'evaporation. Dans une deuxieme partie ils exposent les resultats obtenus sur des echantillons d'UO{sub 2} portes sous irradiation a des temperatures comprises entre 150 deg C et 2000 deg C: - A basse temperature la variation de la quantite degagee suivant la periode des isotopes etudies montre que le recul n'est pas la seule cause du degagement des gaz. - Au-dessus de 1800 deg C on a note une perte de poids par evaporation et on a evalue l'influence de ce phenomene sur la liberation des gaz: ainsi la fraction du {sup 135}Xe liberee a 2000 deg C par d'autres processus

Lidar-measurement of the atmospheric aerosols' extinction based on the field study SAMUM-1; Lidar-Messung der Extinktion des atmosphaerischen Aerosols am Beispiel der Feldstudie SAMUM-1

Energy Technology Data Exchange (ETDEWEB)

Esselborn, Michael

2008-07-01

In the frame of this thesis a high-resolution spectral LIDAR (HSRL) was used for the field study SAMUM during May/June 2006 and January/February 2008 on board of the research aircraft Falcon. The intensity of the LIDAR signals are mainly influences by backscattering and extinction of atmospheric particles (aerosols). Using a narrow-band optical filter the HSRL allows the measurement of the molecular backscattering besides the total atmospheric backscattering. During SAMUM-1 the optical properties of the Sahara dust aerosols were measured for the first time, esp. its extinction, the ratio extinction/backscattering and the depolarization close to the source region. The results of the optical density of the aerosols were compared with satellite-based data. South of the Atlas-mountains optical aerosol densities in the range of 0.50 to 0.60 were measured.

Disposal of Waste into the Atmosphere; Elimination des Dechets Radioactifs dans l'Atmosphere; 0423 0414 0410 ; Evacuacion de Desechos Radiactivos en la Atmosfera

Energy Technology Data Exchange (ETDEWEB)

Schulte, H. F. [Health Division, Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

1960-07-01

The atmosphere can be compared to the hydrosphere and the lithosphere as a recipient of wastes, but the presence of airborne wastes is of more immediate concern to human life. There are two very distinct problems presented by atmospheric pollution, (1) that in the immediate vicinity of a plant and (2) the world-wide problem from long-term, widespread air pollution. Short- range problems have existed for many years as a result of non-radioactive wastes such as coal-smoke, sulphur dioxide and hydrogen fluoride. However, only in recent years has this problem received intense scientific study. Meteorological conditions play an important role in this problem. In some cases emission rates have been controlled in keeping with meteorological predictions. However, the basic solution is still that of reducing emission rates to the lowest possible values. (author) [French] L'atmosphere peut etre comparee a l'hydrosphere et a la lithosphere en tant que receptacle eventuel de dechets, mais la presence de dechets en suspension dans l'air est plus preoccupante pour la vie humaine. La pollution atmospherique pose deux problemes nettement distincts: 1) un probleme de portee limitee concernant le voisinage immediat d'une usine, et 2) un probleme de portee mondiale, savoir la pollution largement repandue, a long terme, de l'atmosphere. Des problemes de portee limitee se sont poses depuis de nombreuses annees ; ils sont lies a la presence dans l'atmosphere de dechets non radioactifs, tels que les fumees produites par le charbon, l'anhydride sulfurique et l'anhydride fluorhydrique. Cependant, ce n'est que recemment que ce probleme a ete soumis a une etude scientifique poussee. Les conditions meteorologiques jouent la un role important. Dans certains cas, les intensites d'emission ont ete controlees en tablant sur les previsions meteorologiques. Toutefois, la solution fondamentale est encore de reduire l'intensite d'emission a la plus faible valeur possible. (author) [Spanish] Si bien

Aerosol typing - key information from aerosol studies

Science.gov (United States)

Mona, Lucia; Kahn, Ralph; Papagiannopoulos, Nikolaos; Holzer-Popp, Thomas; Pappalardo, Gelsomina

2016-04-01

Aerosol typing is a key source of aerosol information from ground-based and satellite-borne instruments. Depending on the specific measurement technique, aerosol typing can be used as input for retrievals or represents an output for other applications. Typically aerosol retrievals require some a priori or external aerosol type information. The accuracy of the derived aerosol products strongly depends on the reliability of these assumptions. Different sensors can make use of different aerosol type inputs. A critical review and harmonization of these procedures could significantly reduce related uncertainties. On the other hand, satellite measurements in recent years are providing valuable information about the global distribution of aerosol types, showing for example the main source regions and typical transport paths. Climatological studies of aerosol load at global and regional scales often rely on inferred aerosol type. There is still a high degree of inhomogeneity among satellite aerosol typing schemes, which makes the use different sensor datasets in a consistent way difficult. Knowledge of the 4d aerosol type distribution at these scales is essential for understanding the impact of different aerosol sources on climate, precipitation and air quality. All this information is needed for planning upcoming aerosol emissions policies. The exchange of expertise and the communication among satellite and ground-based measurement communities is fundamental for improving long-term dataset consistency, and for reducing aerosol type distribution uncertainties. Aerosol typing has been recognized as one of its high-priority activities of the AEROSAT (International Satellite Aerosol Science Network, http://aero-sat.org/) initiative. In the AEROSAT framework, a first critical review of aerosol typing procedures has been carried out. The review underlines the high heterogeneity in many aspects: approach, nomenclature, assumed number of components and parameters used for the

Adsorption and Biocirculation in Oceanic Waters; Adsorption et Biocirculation dans les Eaux des Oceans

Energy Technology Data Exchange (ETDEWEB)

Zenkevich, L. A.

1960-07-01

la contamination des oceans par des produits radioactifs. De toute evidence, les hommes de science se preoccupent de plus en plus du role des organismes vivants sur le transport et la diffusion des substances radioactives dans toutes les niasses d'eau. MM. Ketchum et Bowen etudient ce qu'ils appellent le 'transport biologique' et s'efforcent, dans des travaux d'un grand interet, de donner une expression numerique a ce transport et de le comparer au 'transport physique'. Une notion nouvelle est apparue, celle de 'biocirculation'. On ne saurait, de toute evidence, negliger l'importance de ce facteur, tant du point de vue du transport que de celui de 1-adsorption. La masse des substances minerales en suspension dans l'eau (substances ne contenant aucun organisme vivant), qui sont caracterisees par une mobilite relativement faible, ainsi que les bacteries, le phytoplancton et le zooplancton creent une enorme surface d'adsorption (tableaux 1 et 2): Les masses d'eau oceaniques contiennent en effet une grande quantite de ces elements inertes et organismes planctoniques, animaux et vegetaux. La determination quantitative de tous les elements en suspension permet d'apprecier le role qu'ils jouent en tant que surface d'adsorption et moyen de biocirculation (dans le sens vertical et dans le sens horizontal). Les tableaux ci-apres indiquent la surface d'adsorption des differents groupes planctoniques dans les zones de diffusion de densite moyenne et la biocirculation au sein d'une colonne de 1 m{sup 2} dans ces zones.

New applications of radio-isotopes in France; Quelques nouvelles applications des radioelements en France

Energy Technology Data Exchange (ETDEWEB)

Leveque, P; Hours, R; Martinelli, P; May, S; Sandier, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires; Brillant, J [Societe Soletanche (France)

1958-07-01

unite de celui du metal de base. L'ition de ciment dans les forages a pour but la consolidation et l'impermeabilisation des sols dans une certaine zone. L'extention de cette zone est etudiee en marquant le ciment et en envoyant dans les forages voisins non injectes une sonde Geiger-Muller qui decele si le ciment a ou non atteint ces forages. On peut ainsi controler l'extension de la zone injectee. La cinetique des echanges d'ions entre differents outremers et des solutions acqueuses est etudiee en suivant un ion radioactif, soit dans la solution, soit dans l'outremer lui-meme. Differentes valeurs de coefficients de diffusion et d'energies d'activation sont donnees par les echanges etudies. (auteur)

The Radioisotopic Determination of Diffusion Coefficients and Currents in Natural Waters. Surface Collection of Radioactive Fall-Out on a Large Alpine Lake; Determination par detection nucleaire des coefficients de diffusion et des courants dans les eaux naturelles. Evolution de la surface de collection d'un grand lac alpin pour les retombees radioactives; Opredelenie koehffitsienta diffuzii i skorosti techeniya estestvennykh vod pri pomoshchi yadernogo detektirovaniya. Ehvolyutsiya poverkhnosti sbora radioaktivnykh osadkov na bol'shom al'pijskom ozere; Determinacion por deteccion nuclear de los coeficientes de difusion y de las corrientes en las aguas naturales evolucion de la superficie de captacion de un gran lago alpino para las precipitaciones radiactivas

Energy Technology Data Exchange (ETDEWEB)

Chesselet, R.; Nordemann, D. [Service d' Electronique Physique, Centre d' Etudes Nucleaires de Saclay (France); Dussart, B. [Centre de Recherches Hydrobiologiques, CNRS, Gif-sur-Yvette (France)

1963-08-15

In an initial stage, the authors brought about the in situ diffusion of a radioactive emitter (sodium-22, in the form of Na{sup +}) with very low activity, i.e. less than 1 mc. The diffusion laws applied in this case made it easy to predict the rate of diffusing of the {sup r}adioactive cloud{sup .} In this way, plotting the activities, as measured by two suitably placed gamma detectors, against time permits the estimation of a diffusion coefficient for the emitter used and, if appropriate, the measurement of current velocity at the point of measurement (in the case described, the Lake of Geneva). Subsequently, and in conjunction with a geophysical study on the general problem of radioactive fall-out, the authors worked on the increases in radioactive fall-out caused by nuclear tests in the atmosphere (October 1961 - January 1962). Measurements of radioactivity were made every day on samples of Lake Geneva water taken at depths of 0 m, 10 m and 20 m and also on a collector of dry and moist atmospheric fall-out. Despite the complex pattern, over a period, of theincreasesinfall-out , the interpretation of the diagrams obtained can help to explain what happens to radioactive products in the diffusion and current conditions encountered. The use of the diffusion of radioactive products in very small quantities and of the various highly sensitive techniques of nuclear detection now available can lead to a better understanding of in situ diffusion and of the movement of natural water masses. (author) [French] Dans un premiere etape, les auteurs ont provoque la diffusion in situ d'un emetteur radioactif, le sodium 22, sous forme de Na{sup +}, avec des activites tres faibles, inferieures au millicurie. Les lois de la diffusion appliquee a ce cas permettent aisement de prevoir l'allure du 'n'uage radioactif'' en cours de diffusion. Ainsi, l'enregistrement en fonction du temps des activites mesurees par deux detecteurs gamma convenablemen t disposes conduit a l'evaluation d

Lidar-measurement of the atmospheric aerosols' extinction based on the field study SAMUM-1; Lidar-Messung der Extinktion des atmosphaerischen Aerosols am Beispiel der Feldstudie SAMUM-1

Energy Technology Data Exchange (ETDEWEB)

Esselborn, Michael

2008-07-01

In the frame of this thesis a high-resolution spectral LIDAR (HSRL) was used for the field study SAMUM during May/June 2006 and January/February 2008 on board of the research aircraft Falcon. The intensity of the LIDAR signals are mainly influences by backscattering and extinction of atmospheric particles (aerosols). Using a narrow-band optical filter the HSRL allows the measurement of the molecular backscattering besides the total atmospheric backscattering. During SAMUM-1 the optical properties of the Sahara dust aerosols were measured for the first time, esp. its extinction, the ratio extinction/backscattering and the depolarization close to the source region. The results of the optical density of the aerosols were compared with satellite-based data. South of the Atlas-mountains optical aerosol densities in the range of 0.50 to 0.60 were measured.

Radiative modeling and characterization of aerosol plumes hyper-spectral imagery; Modelisation radiative et caracterisation des panaches d'aerosols en imagerie hyperspectrale

Energy Technology Data Exchange (ETDEWEB)

Alakian, A

2008-03-15

This thesis aims at characterizing aerosols from plumes (biomass burning, industrial discharges, etc.) with hyper-spectral imagery. We want to estimate the optical properties of emitted particles and also their micro-physical properties such as number, size distribution and composition. To reach our goal, we have built a forward semi-analytical model, named APOM (Aerosol Plume Optical Model), which allows to simulate the radiative effects of aerosol plumes in the spectral range [0,4-2,5 {mu}m] for nadir viewing sensors. Mathematical formulation and model coefficients are obtained from simulations performed with the radiative transfer code COMANCHE. APOM is assessed on simulated data and proves to be accurate with modeling errors between 1% and 3%. Three retrieval methods using APOM have been developed: L-APOM, M-APOM and A-APOM. These methods take advantage of spectral and spatial dimensions in hyper-spectral images. L-APOM and M-APOM assume a priori knowledge on particles but can estimate their optical and micro-physical properties. Their performances on simulated data are quite promising. A-APOM method does not require any a priori knowledge on particles but only estimates their optical properties. However, it still needs improvements before being usable. On real images, inversion provides satisfactory results for plumes above water but meets some difficulties for plumes above vegetation, which underlines some possibilities of improvement for the retrieval algorithm. (author)

Distribution and removal of transuranic elements and cerium deposited by the inhalation route; Distribution et elimination des transuraniens et du cerium deposes par l'intermediaire des voies respiratoires; Raspredelenie transuranovykh ehlementov i tseriya, otkladyvayushchikhsya v rezul'tate vdykhaniya i ikh udalenie; Distribucion y eliminacion de elementos transuranicos y de cerio depositados por inhalacion

Energy Technology Data Exchange (ETDEWEB)

Bair, W. J.; Tombropoulos, E. G.; Park, J. F. [Hanford Atomic Products Operation, General Electric Company, Richland, WA (United States)

1963-02-15

Tissue distribution and excretion of inhaled radioactive isotopes varied with the chemical form and the particle size of the aerosols. In dogs, 30 d after inhalation of plutonium nitrate, 70% of the body burden was in the lungs, 10% in liver, and 15% in the skeleton. After inhalation of P{sup 239} O{sub 2} aerosols with a Count Median Diameter (CMD) of 0.12{mu}m, 71% of the body burden was in the lungs, 3% in the bronchial lymph nodes, 4.4% in muscle, 1.3% in skeleton, and 20% was uniformly distributed throughout all remaining tissues. After inhalation of P{sup 239} O{sub 2} aerosols with CMD's of 0.3 to 0.6 {mu}m; the lungs contained 98%, the bronchial lymph nodes about 1% and all other tissues the remaining one per cent. These data and the analysis of urine and faeces defined the relative importance of the three routes by which inhaled radioactive isotopes were cleared from the lung, e.g. movement up the trachea by ciliary action followed by excretion in the faeces, transport across the alveolar membrane and redistribution in other tissue with gradual excretion in urine and transport to the bronchial lymph nodes which accumulate inhaled insoluble materials. Therapy agents were tested that would be expected to increase the clearance of radioactive isotopes from the lung by routes which would avoid accumulation in other, perhaps more radiosensitive tissues. These include chelating agents, wetting agents, irritants, sympathomimetic, parasympathomimetic, parasympatholytic and antihistamine drugs. Diethylenetriamine-pentaacetic acid (DTPA), a chelating agent, administered by aerosols or intraperitoneally caused rapid transport of Ce{sup 144} -Pr{sup 144} from the lung and from the body via urinary excretion. One month after exposure to Ce{sup 144} O{sub 2} treated rats and dogs retained less than 10% of the Ce{sup 144} -Pr{sup 144} levels of untreated animals. (author) [French] La distribution dans les tissus et l'excretion des radioisotopes inhales varient selon la

Instruments used to measure or check {alpha}, {beta}, {gamma} activity and neutron emission in the course of processing ore or irradiated fuel; Appareils de mesure ou de controle {alpha}, {beta}, {gamma}, n, des circuits des usines de traitement du minerai ou du combustible irradie

Energy Technology Data Exchange (ETDEWEB)

Blanc, A; Brunet, M; Kermagoret, M; Labeyrie, J; Roux, G; Vasseur, J; Weil, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1959-07-01

One of the methods checking ores in the course of treatment is the rapid quantitative determination of thorium. This measurement is carried out by means of a scintillation instrument which shows the {beta} and {alpha} coincidences of ThC and ThC'. The treatment of irradiated fuel is accompanied by a large number of radioactive checks relative to the performance of the fixation and elution operations of uranium in the ion exchangers, to the concentration of radioactivity of effluent sent from the plant into watercourses. The operations of fixation and elution of the uranium are checked automatically by an instrument which takes a sample of 5 cm{sup 3} of solution, evaporates it and measures its activity every 10 or 20 minutes. Plutonium concentrations are measured: - in the presence of strong {beta} {gamma} activities, by means of rotating cylinder detectors; - in the presence of weak {beta} {gamma} activities, by means of {alpha} detectors scanning a constant level liquid surface; - by means of fission chambers relatively insensitive to {gamma}. Fission product concentrations are measured by chambers, counters or scintillators, according to the amount of {gamma} activity present. Finally, the activity of effluent to be emptied into watercourses is checked by means of a scintillation instrument, which measures the {alpha} activity on the one hand, and on the other hand the {beta} {gamma} activity of residue from a 100 cm{sup 3} sample taken and evaporated in 20 minutes. (author) [French] Parmi les controles relatifs au minerai en cours de traitement, figure le dosage rapide de thorium. Cette mesure est realisee au moyen d'un appareillage a scintillation qui met en evidence la coincidence des emissions {beta} et {alpha} du ThC et du ThC'. Le traitement des combustibles irradies s'accompagne d'un grand nombre de controles radioactifs portant sur le fonctionnement des operations de fixation et d'elution de l'uranium dans les echangeurs d'ions, sur la concentration du

Localizing by autoradiography at -195 deg radioactive areas in rats exposed to a high flux of thermal neutrons, importance of phosphorus 32 in consecutive internal irradiation; Localisation par autoradiographie a -195 deg des zones radioactives chez le rat expose a un haut flux de neutrons thermiques, importance du phosphore 32 dans l'irradiation interne consecutive

Energy Technology Data Exchange (ETDEWEB)

Chanteur, J; Pellerin, P [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1961-07-01

Rats weighing 25 g were exposed for 5 mn to a flux of 6.10{sup 12} thermal neutrons/cm{sup 2}/s. Anatomical autoradiography at -195 deg. C has enabled the radioactive organs to be easily localised, to follow in course of time the decrease of radioactivity, and from it to deduce the probable nature of the numerous emitters in question. In particular, the phosphorus 32 has thus appeared to be one of those responsible for internal irradiation, general, on the one hand, by activating cellular phosphorus, local, on the other, by activating bony phosphates. Owing to this, an accidental irradiation by neutrons might have consequences that are both somatic (elective irradiation of the bone marrow) and genetic (activation of nucleic acids). The gamma spectrometry has confirmed the nature of certain other emitters. (author) [French] Des rats de 25 g ont ete exposes pendant 5 mn a un flux de 6.10{sup 12} neutrons thermiques/cm{sup 2}/s. L'autoradiographie anatomique a -195 deg. C a permis de localiser facilement les organes radioactifs, de suivre dans le temps la decroissance de la radioactivite, et d'en deduire la nature probable des nombreux emetteurs en cause. En particulier, le phosphore 32 est ainsi apparu comme l'un des responsables de l'irradiation interne, d'une part generale par activation du phosphore cellulaire, d'autre part locale par activation des phosphates osseux. Une irradiations accidentelle par neutrons aurait, de ce fait, des consequences a la fois somatiques (irradiation elective de la moelle osseuse) et genetiques (activation des acides nucleiques). La spectrometrie gamma a confirme la nature de certains autres emetteurs. (auteur)

Reservoir patterns of soot, organic particles, total carbon, soluble substances and aerosols (numbers and mass) in the droplet and interstitial phase of clouds; Reservoiraufteilung von Russ, organischen Bestandteilen, Gesamtkohlenstoff, loeslichen Substanzen und Aerosolpartikeln (Anzahl und Masse) in der Tropfen- und Zwischenraumphase von Wolken. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Wieprecht, W.; Acker, K.; Moeller, D.; Auel, R.; Hofmeister, J.; Kalass, D.

2002-07-01

The reservoir patterns of the constitutents of representative clouds over Germany were investigated for a better characterisation of their optical, microphysical and chemical properties. One of the key points of interest was the distribution of carbonaceous aerosol particles in the droplet and interstitial phase, which was to provide information on the role of absorbing (soot or BC) and organic carbon (OC) in cloud formation. Data about the effects of potential CCN on cloud characteristics and about the changes in aerosol particles induced by cloud processes are required as input for models of the chemical and climate effects of atmospheric aerosol. [German] Ziel des Projektes war eine moeglichst umfassende experimentelle Ermittlung der Reservoiraufteilung der Inhaltsstoffe repraesentativer Wolken ueber der Bundesrepublik Deutschland, um ihre optischen, mikrophysikalischen und chemischen Eigenschaften besser zu charakterisieren. Ein besonderer Schwerpunkt des Gesamtprojekts lag auf der Bestimmung der Verteilung kohlenstoffhaltiger Aerosolpartikel auf die Tropfen- und interstitielle Phase, um Aufschluesse ueber die Rolle von absorbierendem (Russ oder BC) und organischem Kohlenstoff (OC) bei der Wolkenbildung zu erhalten. Erkenntnisse sowohl ueber die Beeinflussung potentieller CCN auf Wolkeneigenschaften als auch ueber die Veraenderung der Aerosolpartikel durch Wolkenprozesse sind erforderlich als Eingangsdaten in entsprechende Modelle, um die chemischen und klimatischen Effekte des atmosphaerischen Aerosols zu bestimmen. (orig.)

Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le ...

African Journals Online (AJOL)

Efficacité des néonicotinoïdes et des pyréthrinoïdes utilisés contre le foreur des tiges du cacaoyer ( Eulophonotus myrmeleon Felder : Lepidoptera, Cossidae). Implications dans la stratégie de protection de la cacaoculture en Côte d'Ivoire.

Santé des adolescents et des jeunes au Burkina Faso : état des ...

African Journals Online (AJOL)

Il s'est agi d'une étude évaluative ayant utilisé une revue documentaire associée à une interview des acteurs clés et un atelier de validation et d'identification des interventions pertinentes pour un plan stratégique national. La situation de la santé des adolescents et des jeunes est caractérisée par des grossesses précoces ...

La fabrique des sciences des institutions aux pratiques

CERN Document Server

Benninghoff, Martin; Crettaz von Roten, Fabienne; Merz, Martina

2006-01-01

Aujourd'hui, les façons de produire, d'organiser, d'évaluer et d'utiliser les savoirs sont en profond débat. De plus en plus, l'Etat, la société civile et l'économie tentent d'influencer les activités des universités et des laboratoires de recherche. Ces développements mettent à l'épreuve tout à la fois les fondements des systèmes d'enseignement supérieur et de recherche, l'autonomie des institutions scientifiques, la définition des frontières des savoirs et l'acceptation des sciences. Dans des contextes suisses et européens, cet ouvrage s'intéresse aux manières dont les sciences et les technologies sont fabriquées, en analysant leurs institutions et les pratiques. A partir d'une approche relationnelle, les sciences et les technologies sont conçues comme des phénomènes profondément sociaux, culturels et politiques. Une telle démarche déstabilise les visions parfois idéalisées et stéréotypées de la construction des savoirs. Des études de cas détaillées décrivent des phénomè...

Organic aerosols

International Nuclear Information System (INIS)

Penner, J.E.

1994-01-01

Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN

Research on aerosol formation, aerosol behaviour, aerosol filtration, aerosol measurement techniques and sodium fires at the Laboratory for Aerosol Physics and Filter Technology at the Nuclear Research Center Karlsruhe

Energy Technology Data Exchange (ETDEWEB)

Jordan, S; Schikarski, W; Schoeck, W [Gesellschaft fuer Kernforschung mbH, Karlsruhe (Germany)

1977-01-01

The behaviour of aerosols in LMFBR plant systems is of great importance for a number of problems, both normal operational and accident kind. This paper covers the following: aerosol modelling for LMFBR containment systems; aerosol size spectrometry by laser light scattering; experimental facilities and experimental results concerned with aerosol release under accident conditions; filtration of sodium oxide aerosols by multilayer sand bed filters.

Research on aerosol formation, aerosol behaviour, aerosol filtration, aerosol measurement techniques and sodium fires at the Laboratory for Aerosol Physics and Filter Technology at the Nuclear Research Center Karlsruhe

International Nuclear Information System (INIS)

Jordan, S.; Schikarski, W.; Schoeck, W.

1977-01-01

The behaviour of aerosols in LMFBR plant systems is of great importance for a number of problems, both normal operational and accident kind. This paper covers the following: aerosol modelling for LMFBR containment systems; aerosol size spectrometry by laser light scattering; experimental facilities and experimental results concerned with aerosol release under accident conditions; filtration of sodium oxide aerosols by multilayer sand bed filters

Purification by ion exchange resins of the heavy water of the reactors EL 1 and EL 2. A - the purifying process. Equipment and results; Purification par resines echangeuses d'ions de l'eau lourde des reacteurs EL1 et EL2. A - conduite de la purification. Installations et resultats

Energy Technology Data Exchange (ETDEWEB)

Chenouard, J; Roth, E [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

The heavy water was purified by tapping off part of the moderator over a mixed bed of anion and cation exchangers. The heavy water leaving the columns has a resistivity reaching several-meg-ohms, which allows the resistivity of the moderator to be maintained between 10{sup 5} and 10{sup 6} ohms/cm. Two methods of deuteration of the ion exchangers are described, as well as the heavy water recuperation from resins charged with radioactive products. The influence of the purity of the water on the radiolytic dissociation is investigated. An interpretation of the variations in pH and of the formation of hydrogen peroxide is given. In addition the report contains a general description of the EL1 and EL2 purification installations. (author) [French] L'epuration de l'eau lourde a ete effectuee en derivant une partie du moderateur sur un lit melange d'echangeurs d'anions et de cations. Les colonnes delivrent de l'eau lourde dont la resistivite atteint plusieurs megohms; ceci permet d'entretenir la resistivite du moderateur entre 10{sup 5} et 10{sup 6} ohms/cm. Deux procedes deuteriation des echangeurs d'ions sont decrits de meme que la recuperation de l'eau lourde partir des resines chargees de produits radioactifs. L'influence de la purete de l'eau sur sa dissociation radiolytique est etudiee. Une interpretation est donnee des variations de pH et de la formation d'eau oxygenee. Le rapport comprend en outre une description generale des installations d'epuration de EL1et EL2. (auteur)

The tropospheric aerosol at mid-latitudes - microphysics, optics, and climate forcing illustrated by the LACE 98 field study; Das troposphaerische Aerosol in mittleren Breiten - Mikrophysik, Optik und Klimaantrieb am Beispiel der Feldstudie LACE 98

Energy Technology Data Exchange (ETDEWEB)

Fiebig, M.

2001-07-01

This study investigates the column closure of optical aerosol parameters as part of the Lindenberg Aerosol Characterisation Experiment (LACE 98). The optical aerosol parameters were calculated from microphysical aerosol parameters which were measured height resolved from tropopause to boundary layer and compared with the direct measurement of the respective property (closure). The closure allows the validation of the measured aerosol properties and the inversion of aerosol properties which are not measurable directly. The radiative forcings of the measured aerosol columns are estimated. The measured, quality assured microphysical aerosol properties are parameterized and tabulated as input data for models. The successful closure of the aerosol column's optical depth validates the measured particle size distributions, whereas the successful closure of the backscatter coefficient validates the assumptions made on the aerosol chemical composition and serves to deduce its state of mixture, the latter point exemplified using a 7 day old forest fire aerosol. The local, instantaneous radiative forcing of the measured continental particle columns are estimated to lie between -33 W/m{sup 2} for continental and -6 W/m{sup 2} for marine air masses for a solar zenith angle of 56 . (orig.) [German] Als Teil des Lindenberger Aerosol Charakterisierungsexperimentes (LACE 98) behandelt diese Arbeit die Saeulenschliessung optischer Aerosolparameter. Diese wurden aus den von Tropopause bis Grenzschicht hoehenaufgeloest gemessenen mikrophysikalischen Aerosoleigenschaften berechnet, um sie mit den am gleichen Ort direkt gemessenen optischen Aerosolparametern zu vergleichen (Schliessung). Es wird gezeigt, dass die Schliessung die Qualitaetssicherung der gemessenen Aerosoleigenschaften und die Invertierung direkt nicht messbarer Aerosoleigenschaften ermoeglicht. Die Strahlungsantriebe der vermessenen Aerosolsaeulen werden abgeschaetzt. Die qualitaetsgesicherten gemessenen

Calibration of aerosol radiometers. Special aerosol sources

International Nuclear Information System (INIS)

Belkina, S.K.; Zalmanzon, Yu.E.; Kuznetsov, Yu.V.; Fertman, D.E.

1988-01-01

Problems of calibration of artificial aerosol radiometry and information-measurement systems of radiometer radiation control, in particular, are considered. Special aerosol source is suggested, which permits to perform certification and testing of aerosol channels of the systems in situ without the dismantling

Tombes et cimetières éthiopiens : des rois, des saints, des anonymes1

OpenAIRE

Derat, Marie-Laure

2009-01-01

L’histoire des tombes et cimetières éthiopiens, dans la longue durée, en est encore à ses balbutiements. Si les tombes des saints et des rois nous sont un peu mieux connus grâce à des textes témoignant à la fois des enjeux entourant les sépultures de ces personnages hors du commun et des soins apportés à leur inhumation, en revanche, les cimetières ordinaires échappent encore largement à l’enquête, en grande partie parce que le commun des mortels est inhumé dans l’anonymat et dans un grand dé...

Using the OMI aerosol index and absorption aerosol optical depth to evaluate the NASA MERRA Aerosol Reanalysis

Science.gov (United States)

Buchard, V.; da Silva, A. M.; Colarco, P. R.; Darmenov, A.; Randles, C. A.; Govindaraju, R.; Torres, O.; Campbell, J.; Spurr, R.

2015-05-01

A radiative transfer interface has been developed to simulate the UV aerosol index (AI) from the NASA Goddard Earth Observing System version 5 (GEOS-5) aerosol assimilated fields. The purpose of this work is to use the AI and aerosol absorption optical depth (AAOD) derived from the Ozone Monitoring Instrument (OMI) measurements as independent validation for the Modern Era Retrospective analysis for Research and Applications Aerosol Reanalysis (MERRAero). MERRAero is based on a version of the GEOS-5 model that is radiatively coupled to the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) aerosol module and includes assimilation of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor. Since AI is dependent on aerosol concentration, optical properties and altitude of the aerosol layer, we make use of complementary observations to fully diagnose the model, including AOD from the Multi-angle Imaging SpectroRadiometer (MISR), aerosol retrievals from the AErosol RObotic NETwork (AERONET) and attenuated backscatter coefficients from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) mission to ascertain potential misplacement of plume height by the model. By sampling dust, biomass burning and pollution events in 2007 we have compared model-produced AI and AAOD with the corresponding OMI products, identifying regions where the model representation of absorbing aerosols was deficient. As a result of this study over the Saharan dust region, we have obtained a new set of dust aerosol optical properties that retains consistency with the MODIS AOD data that were assimilated, while resulting in better agreement with aerosol absorption measurements from OMI. The analysis conducted over the southern African and South American biomass burning regions indicates that revising the spectrally dependent aerosol absorption properties in the near-UV region improves the modeled-observed AI comparisons

Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

African Journals Online (AJOL)

Face à ce constat, le défi de la recherche serait la détermination du niveau actuel de contamination des légumes feuilles et des eaux du barrage et celui de l'État serait l'initiation de programmes de sensibilisation des producteurs par rapport à une gestion plus rigoureuse des pesticides. Mots-clés : pratiques paysannes, ...

La convergence des rôles respectifs des relationnistes et des journalistes influence-t-elle la perception qu'ils ont les uns des autres?

DEFF Research Database (Denmark)

Valentini, Chiara

2017-01-01

la convergence des rôles respectifs des praticiens des relations publiques et des journalistes a un effet favorable sur la perception qu’ils ont les uns des autres. L’effet est plus marqué chez les praticiens des relations publiques, car leur vision de la profession en journalisme correspond à celle...

Mécanique des sols et des roches

CERN Document Server

Vullier, Laurent; Zhao, Jian

2016-01-01

La mécanique des sols et la mécanique des roches sont des disciplines généralement traitées séparément dans la littérature. Pour la première fois, un traité réunit ces deux spécialités, en intégrant également les connaissances en lien avec les écoulements souterrains et les transferts thermiques. A la fois théorique et pratique, cet ouvrage propose tout d'abord une description détaillée de la nature et de la composition des sols et des roches, puis s'attache à la modélisation de problèmes aux conditions limites et présente les essais permettant de caractériser les sols et les roches, tant d'un point de vue mécanique qu'hydraulique et thermique. La problématique des sols non saturés et des écoulements multiphasiques est également abordée. Une attention particulière est portée aux lois de comportement mécanique et à la détermination de leurs paramètres par des essais in situ et en laboratoire, et l'ouvrage offre également une présentation détaillée des systèmes de classi...

Évaluation des pratiques agricoles des légumes feuilles : le cas des ...

African Journals Online (AJOL)

SARAH

30 sept. 2017 ... ... de Biochimie et Immunologie Appliquée, Centre de Recherche en Sciences Biologiques, Alimentaires et .... l'intoxication des agriculteurs et des consommateurs, ... source d'alimentation en eau et au pouvoir d'achat des.

Study of the magnetic susceptibilities of some plutonium derivatives; Etude des susceptibilites magnetiques de quelques derives du plutonium

Energy Technology Data Exchange (ETDEWEB)

Raphael, G [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-06-01

We present a detailed description of an automatic recording apparatus for magnetic susceptibility measurement of radioactive samples in the temperature range 4 K - 1200 K. We have measured the magnetic susceptibility of various plutonium compounds: - PuO{sub 2}, Pu{sub 2}O{sub 3}, PuO{sub 2-x}, - PuS, Pu{sub 2}S{sub 3}, Pu{sub 3}S{sub 4}, (U{sub x}Pu{sub 1-x})S - PuN - PuC{sub 1-x}(N,O,H,vacancy), Pu{sub 2}C{sub 3}, (U{sub 0.85}Pu{sub 0.15})C. The curves of susceptibilities versus temperature show many magnetic transitions. The interpretation of these results shows the existence of magnetic moments carried by the 5 f electrons and localized on the metallic sites as well as the great influence of the 'crystal field' in all these compounds. (author) [French] Nous decrivons d'une facon detaillee un appareil permettant de mesurer d'une facon continue et automatique des susceptibilites magnetiques sur des echantillons radioactifs dans un domaine de temperature s'etalant de 4 K a 1200 K. Nous avons mesure les susceptibilites magnetiques de certains composes du plutonium tels que: - PuO{sub 2}, Pu{sub 2}O{sub 3}, PuO{sub 2-x} - PuS, Pu{sub 2}S{sub 3}, Pu{sub 3}S{sub 4}, (U{sub x}Pu{sub 1-x})S - PuN - PuC{sub 1-x}(N,O,H,vacancy), Pu{sub 2}C{sub 3}, (U{sub 0.85}Pu{sub 0.15})C. Les courbes de susceptibilite magnetique en fonction de la temperature mettent en evidence de nombreuses transitions magnetiques. L'interpretation de ces resultats a montre l'existence de moments magnetiques portes par les electrons f et localises sur les sites metalliques ainsi que l'influence tres grande du champ cristallin. (auteur)

Modelisation des effets physico-techniques pour la conception des ...

African Journals Online (AJOL)

automatisation dans les installations industrielles a besoin d'une régulation automatique des commandes des processus technologiques pour lesquelles certaines contraintes sont à relever compte tenu des exigences des innovations scientifiques de ...

Desirable New Geologic Research in Support of Radioactive Waste Disposal as Indicated by Hanford Experience; Nouvelles Recherches Geologiques Souhaitables au Sujet de l'Elimination des Dechets Radioactifs, Selon les Indications Fournies par l'Experience de Hanford; 041f 0420 041e 0412 0415 0414 ; Nuevas Investigaciones Geologicas que Convendria Hacer para Facilitar la Evacuacion de Desechos Radiactivos Siguiendo las Indicaciones Proporcionadas por las Experiencias Efectuadas en Hanford

Energy Technology Data Exchange (ETDEWEB)

Brown, Randall E. [Hanford Laboratories, Hanford Atomic Products Operation, General Electric Company, Richland, WA (United States)

1960-07-01

Hanford consiste a intercaler le plus grand nombre possible de structures geologiques entre les lieux d'elimination et les points les plus proches d'irradiation eventuelle des populations. Selon la decontamination de Simpson, ce procede fait appel aux notions de temporisation et de desintegration. Les problemes qui se posent a Hanford pour l'elimination des dechets portent sur les points suivants : - 1. l'inexactitude des donnees geologiques quantitatives; 2. l'absence de terrains isotropes et homogenes; 3. la necessite de determiner l'importance quantitative de l'ecart des caracteristiques geologiques et hydrologiques, par rapport a la jnpyexmejj ,4. la necessite de determiner et de mesurer les parametres interessants. Le memoire donne des exemples, pris a Hanford, qui illustrent les points ci-dessus. On a fore 557 puits d'une profondeur totale de 33.000 metres, mais les indications obtenues doivent etre utilisees avec prudence. Les etudes courantes des proprietes aquiferes des sols n'ont qu'une valeur limitee, car les donnees relatives a la permeabilite des differentes structures dans toutes les directions sont presentees globalement sous forme de valeurs moyennes. Les etudes fondees sur les echangea d'ions fournissent des donnees quantitatives d'un interet immediat qui peuvent aider a interpreter les caracteristiques geologiques. Les etudes hydrologiques, associees aux recherches geochimiques et aux donnees geologiques, permettent d'expliquer logiquement l'influence des structures geologiques sur les mouvements des eaux souterraines. L'enfouissement des dechets radioactifs n'est ni une panacee ni une pratique a redouter. A Hanford, en combinant les donnees obtenues par les geologues, les-hydrologistes, les geochimistes et les mathematiciens, on a pu parvenir a de bons resultats en matiere d'enfouissement sans danger des dechets. Il reste neanmoins beaucoup a faire. (author) [Spanish] La evacuacion de desechos radiactivos en el subsuelo depende de la estructura

Vecteurs Singuliers des Theories des Champs Conformes Minimales

Science.gov (United States)

Benoit, Louis

En 1984 Belavin, Polyakov et Zamolodchikov revolutionnent la theorie des champs en explicitant une nouvelle gamme de theories, les theories quantiques des champs bidimensionnelles invariantes sous les transformations conformes. L'algebre des transformations conformes de l'espace-temps presente une caracteristique remarquable: en deux dimensions elle possede un nombre infini de generateurs. Cette propriete impose de telles conditions aux fonctions de correlations qu'il est possible de les evaluer sans aucune approximation. Les champs des theories conformes appartiennent a des representations de plus haut poids de l'algebre de Virasoro, une extension centrale de l'algebre conforme du plan. Ces representations sont etiquetees par h, le poids conforme de leur vecteur de plus haut poids, et par la charge centrale c, le facteur de l'extension centrale, commune a toutes les representations d'une meme theorie. Les theories conformes minimales sont constituees d'un nombre fini de representations. Parmi celles-ci se trouvent des theories unitaires dont les representation forment la serie discrete de l'algebre de Virasoro; leur poids h a la forme h_{p,q}(m)=[ (p(m+1) -qm)^2-1] (4m(m+1)), ou p,q et m sont des entiers positifs et p+q= 2. Ces representations possedent un sous-espace invariant engendre par deux sous-representations avec h_1=h_{p,q} + pq et h_2=h_{p,q} + (m-p)(m+1-q) dont chacun des vecteurs de plus haut poids portent le nom de vecteur singulier et sont notes respectivement |Psi _{p,q}> et |Psi_{m-p,m+1-q}>. . Les theories super-conformes sont une version super-symetrique des theories conformes. Leurs champs appartiennent a des representation de plus haut poids de l'algebre de Neveu-Schwarz, une des deux extensions super -symetriques de l'algebre de Virasoro. Les theories super -conformes minimales possedent la meme structure que les theories conformes minimales. Les representations sont elements de la serie h_{p,q}= [ (p(m+2)-qm)^2-4] /(8m(m+2)) ou p,q et m sont

The Effect of Aerosol Hygroscopicity and Volatility on Aerosol Optical Properties During Southern Oxidant and Aerosol Study

Science.gov (United States)

Khlystov, A.; Grieshop, A. P.; Saha, P.; Subramanian, R.

2014-12-01

Secondary organic aerosol (SOA) from biogenic sources can influence optical properties of ambient aerosol by altering its hygroscopicity and contributing to light absorption directly via formation of brown carbon and indirectly by enhancing light absorption by black carbon ("lensing effect"). The magnitude of these effects remains highly uncertain. A set of state-of-the-art instruments was deployed at the SEARCH site near Centerville, AL during the Southern Oxidant and Aerosol Study (SOAS) campaign in summer 2013 to measure the effect of relative humidity and temperature on aerosol size distribution, composition and optical properties. Light scattering and absorption by temperature- and humidity-conditioned aerosols was measured using three photo-acoustic extinctiometers (PAX) at three wavelengths (405 nm, 532 nm, and 870 nm). The sample-conditioning system provided measurements at ambient RH, 10%RH ("dry"), 85%RH ("wet"), and 200 C ("TD"). In parallel to these measurements, a long residence time temperature-stepping thermodenuder (TD) and a variable residence time constant temperature TD in combination with three SMPS systems and an Aerosol Chemical Speciation Monitor (ACSM) were used to assess aerosol volatility and kinetics of aerosol evaporation. We will present results of the on-going analysis of the collected data set. We will show that both temperature and relative humidity have a strong effect on aerosol optical properties. SOA appears to increase aerosol light absorption by about 10%. TD measurements suggest that aerosol equilibrated fairly quickly, within 2 s. Evaporation varied substantially with ambient aerosol loading and composition and meteorology.

Chemical analysis of radioactive liquid wastes. Volumetric dosage of sulfates in the presence of phosphates, 'nitrochromazo' being used as an indicator; Analyse chimique des effluents radioactifs - dosage volumetrique des sulfates en presence de phosphates a l'aide du 'nitrochromazo' comme indicateur

Energy Technology Data Exchange (ETDEWEB)

Testemale, G; Girault, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1969-07-01

A simple titration technique of SO{sub 4} ions in the presence of PO{sub 4} ions has been perfected. The pH of the medium is stated to 1,7-2,0 the colour of the indicator changes from violet to blue. The method is quick, accurate and can be fitted to biological studies or in the industry of fertilizes. The synthesis method of nitrochromazo (acid 2, 7 bis (4 nitro 2 sulfobenzene 1 azo) 1-8 hydroxynaphthalene 3-6 disulfonic) is described. (authors) [French] Une technique simple de titrage des ions SO{sub 4} en presence d'ions PO{sub 4} a ete mise au point. Le pH du milieu est fixe a 1,7-2,0, le virage de l'indicateur s'effectue du violet au bleu. La methode est rapide, precise et peut etre adaptee a des travaux de biologie ou dans l'industrie des engrais. La methode de synthese du 'Nitrochromazo' (acide 2, 7 bis (4 nitro 2 sulfobenzene 1 azo) 1-8 dihydroxynapthtalene 3-6 disulfonique) est decrite. (auteurs)

Radioprotection problems resulting from the presence of experimental devices around an atomic reactor; Problemes de radioprotection poses par l'implantation de dispositifs experimentaux aupres d'une pile atomique

Energy Technology Data Exchange (ETDEWEB)

Fitoussi, L; Lebouleux, Ph; Bricard, Ph; Moreau, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1965-07-01

The setting up of experimental devices around a reactor produces dangers of irradiation and radioactive contamination which can become very great in the case of an accident, especially if the in-pile portion contains fissile matter. This may result in irradiation of personnel, prohibition of access to the experimental zones until the sources of irradiation and contamination have been eliminated, and a prolonged stoppage of the reactor. The plans for an in-pile experiment should take into account radioprotection factors; the aim of these is to reduce to a minimum the radioactive risks normally encountered during the experiment and to eliminate any risks of bad accidents and their consequences. In this report are classified the various types of experiments requiring installations outside the pile itself; for each of these experiments the particular radioprotection factors are given. In order to make possible a study of the radioactive dangers likely to arise during a projected experiment, the authors summarize the physical and technical data required by radioprotection specialists and give the rules and general advice concerning radioprotection which should be useful during the planning of an in-pile experiment and the setting-up of the equipment. (authors) [French] L'implantation de dispositifs experimentaux aupres des reacteurs cree des risques d'irradiation et de contamination radioactive qui peuvent devenir importants en cas d'accident, surtout si la partie en pile comprend des matieres fissiles. Il peut en resulter des irradiations de personne, l'interdiction des aires experimentales jusqu'a elimination des sources d'irradiation et de contamination, un arret prolonge de la pile. L'etude d'un projet d'experience en pile doit donc tenir compte des considerations de radioprotection dont le souci est de reduire aux niveaux tolerables les risques radioactifs inherents au fonctionnement normal de l'experience et d'eliminer les risques d'accidents graves et leurs

Stratospheric aerosols

International Nuclear Information System (INIS)

Rosen, J.; Ivanov, V.A.

1993-01-01

Stratospheric aerosol measurements can provide both spatial and temporal data of sufficient resolution to be of use in climate models. Relatively recent results from a wide range of instrument techniques for measuring stratospheric aerosol parameters are described. Such techniques include impactor sampling, lidar system sensing, filter sampling, photoelectric particle counting, satellite extinction-sensing using the sun as a source, and optical depth probing, at sites mainly removed from tropospheric aerosol sources. Some of these techniques have also had correlative and intercomparison studies. The main methods for determining the vertical profiles of stratospheric aerosols are outlined: lidar extinction measurements from satellites; impactor measurements from balloons and aircraft; and photoelectric particle counter measurements from balloons, aircraft, and rockets. The conversion of the lidar backscatter to stratospheric aerosol mass loading is referred to. Absolute measurements of total solar extinction from satellite orbits can be used to extract the aerosol extinction, and several examples of vertical profiles of extinction obtained with the SAGE satellite are given. Stratospheric mass loading can be inferred from extinction using approximate linear relationships but under restrictive conditions. Impactor sampling is essentially the only method in which the physical nature of the stratospheric aerosol is observed visually. Vertical profiles of stratospheric aerosol number concentration using impactor data are presented. Typical profiles using a dual-size-range photoelectric dustsonde particle counter are given for volcanically disturbed and inactive periods. Some measurements of the global distribution of stratospheric aerosols are also presented. Volatility measurements are described, indicating that stratospheric aerosols are composed primarily of about 75% sulfuric acid and 25% water

Utilisation sans risque des eaux usées, des excréta et des eaux ...

International Development Research Centre (IDRC) Digital Library (Canada)

Les responsables de ce projet piloteront l'application et l'adaptation des principes directeurs relatifs à l'utilisation sans risque des eaux usées, des excreta et des eaux grises en agriculture et en aquaculture (Guidelines for the Safe Use of Wastewater, Excreta and Greywater in Agriculture and Aquaculture), que ...

Efficiency of the collection of aerosol detectors used in EDF nuclear power stations; Efficacite de collecte des balises aerosol utilisees en CNPE EDF

Energy Technology Data Exchange (ETDEWEB)

Fauvel, S.; Gensdarmes, F. [Institut de Radioprotection et de Surete Nucleaire, DSUISERAC, Laboratoire de Physique et de Metrologie des Aerosols, BP 68, 91192 Gif sur Yvette Cedex (France); Valendru, N. [EDF-DPN I UNIE-GPRE, site de CAP Ampere, 93282 Saint Denis Cedex (France)

2009-07-01

The authors report an investigation performed to asses the efficiency of different radioactive aerosol detectors by comparing the mass concentration sampled by the tested detectors with the reference mass concentration. The authors describe the measurement installation and protocol, and discuss the results obtained for different grain sizes and different renewal rates

ANALYSE DES PERCEPTIONS LOCALES ET DES FACTEURS ...

African Journals Online (AJOL)

AISA

1Faculté des Sciences Agronomiques (FSA), Université d'Abomey-Calavi (UAC), 01 BP 526 Cotonou Bénin. Email : cgbemavo@yahoo.fr. 2Institut National des Recherches Agricoles du Bénin, Centre de Recherches Agricoles d'Agonkanmey (CRA-A),. Laboratoire des Sciences du Sol, Eau et Environnement (LSSEE).

variabilite des productions et des revenus des exploitations

African Journals Online (AJOL)

3Centre de coopération internationale en recherche agronomique pour le développement (CIRAD), UMR Innovation,. Montpellier, France. Doubangolo COULIBALY, Email kone_b@yahoo.fr. RESUME. La durabilité des systèmes de production à base de coton dans un contexte de variabilité des prix aux producteurs et de ...

The use of radioactive tracers in lubrication and wear research; Emploi des indicateurs radioactifs dans les recherches sur la lubrification et l'usure; Ispol'zovanie mechenykh atomov pri issledovanii voprosov smazki i iznosa; Utilizacion de los indicadores radiactivos en los estudios sobre la lubricacion y el desgaste

Energy Technology Data Exchange (ETDEWEB)

Campbell, R B; Grunberg, L; Milne, A A; Wright, K H.R. [Lubrication, Wear and Mechanical Engineering Aspects of Corrosion Division, National Engineering Laboratory, Thorntonhall, Glasgow (United Kingdom)

1962-01-15

In many lubrication and wear problems, processes occurring on a very small scale have to be studied and the great sensitivity of radioactive tracer methods has been successfully applied. Several examples of such applications are cited from the work of the Lubrication and Wear Division of the National Engineering Laboratory in the United Kingdom. The quantitative relation between metal transfer and boundary friction is studied as a function of sliding velocity, surface roughness and the presence of lubricants. In order to study the distribution of wear, cast iron plugs containing Ir{sup 192} are inserted in the liners of a Diesel engine and the radioactivity present in oil samples is measured. Radioactive iron and iron oxide particles are used to study then role in the wear process. The reactivity of strained metal surface is studied with the aid of C{sup 14}- labelled stearic acid and of S{sup 35} in solution. The reaction rates of gear oil additive are being studied by passing short electric-current pulses through metal wires immersed in solutions of compounds labelled with S{sup 35} and P{sup 32}. The build-up of anti-wear films on the surface of gear teeth is being studied as a function of lead, speed and running time. A problem encountered in many of these applications is the conversion of the measured activity into absolute quantities of materials present in surface films or in wear debris. Calibration methods have been developed for this purpose. (author) [French] Pour nombre de problemes relatifs a la lubrification et a l'usure, ou l'on doit etudier des processus se produisant a tres petite echelle, la methode des indicateurs radioactifs, qui presente l'avantage d'etre tres sensible, a donne de bons resultats. Le memoire cite plusieurs exemples d'applications de ce genre, tires des travaux de la Division de la lubrification et de l'usure du National Engineering Laboratory (Royaume-Uni). La relation quantitative entre le transfert de metal et la friction de

Le statut vitaminique des individus et des populations…

Directory of Open Access Journals (Sweden)

Icart Jean-Claude

2000-05-01

Full Text Available Comme le souligne un récent rapport du Haut comité de santé publique, le statut vitaminique des individus et des populations demeure une question d’actualité. Si les études ne révèlent plus de signes évocateurs de carence, au plus des problèmes de déficiences pour certains groupes à risque, des interrogations, demeurent malgré le contexte d’abondance, concernant la couverture des besoins, laquelle pourrait s’avérer inférieure aux valeurs considérées comme satisfaisantes.

Application des TIC à l'atténuation des effets des catastrophes dans ...

International Development Research Centre (IDRC) Digital Library (Canada)

L'Amérique centrale est souvent aux prises avec des inondations et des ... (SIG) et de traitement des images, afin de cartographier les dangers et de modéliser les ... de l'Institut d'étude du développement international de l'Université McGill.

Management of radioactive wastes; Gestion des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

NONE

2005-07-01

The law from December 30, 1991, precisely defines 3 axes of researches for the management of high level and long-lived radioactive wastes: separation/transmutation, surface storage and underground disposal. A global evaluation report about these researches is to be supplied in 2006 by the French government to the Parliament. A first synthesis of the knowledge gained after 14 years of research has led the national commission of the public debate (CNDP) to organize a national debate about the general options of management of high-level and long-lived radioactive wastes before the 2006 date line. The debate comprises 4 public hearings (September 2005: Bar-le-Duc, Saint-Dizier, Pont-du-Gard, Cherbourg), 12 round-tables (October and November 2005: Paris, Joinville, Caen, Nancy, Marseille), a synthesis meeting (December 2005, Dunkerque) and a closing meeting (January 2006, Lyon). This document is the synthesis of the round table debates which took place at Joinville, i.e. in the same area as the Bure underground laboratory of Meuse/Haute-Marne. Therefore, the discussion focuses more on the local impacts of the setting up of a waste disposal facility (environmental aspects, employment, economic development). (J.S.)

La gestion des résultats des entreprises innovantes

OpenAIRE

Dumas, Guillaume

2014-01-01

Cette thèse s’intéresse à la gestion des résultats dans le cadre des entreprises innovantes. Elle est constituée de trois articles. Dans le premier, il s’agit d’examiner si les résultats des entreprises innovantes sont gérés et si le stade de développement des innovations influence cette gestion des résultats. Il apparaît que les résultats des entreprises innovantes sont gérés à la hausse. Cette gestion ne semble intervenir qu’au cours de l’activité d’innovation (c’est-à-dire lorsque les entr...

Etude des erreurs d'estimation des populations par la méthode des captures successives (DeLURY, 2 captures et des captures-recaptures (PETERSEN

Directory of Open Access Journals (Sweden)

LAURENT M.

1978-01-01

Full Text Available L'estimation des populations naturelles par capture-recapture et par captures successives est souvent entachée d'erreur car, dans de nombreux cas, l'hypothèse fondamentale d'égalité des probabilités de captures pour tous les individus dans le temps et dans l'espace n'est pas respectée. Dans le cas des populations de poissons envisagés ici, les captures ont lieu par la pêche électrique. On a pu chiffrer l'ordre de grandeur des erreurs systématiques faites sur l'estimation des peuplements, en fonction des conditions particulières, biotiques et abiotiques, des différents milieux inventoriés.

Radioactive Waste Control at the United Kingdom Atomic Energy Research Establishment, Harwell; Traitement des Dechets Radioactifs au Centre de Recherche sur l'Energie Atomique de Harwell; 041a 041e 041d 0422 0420 041e 041b 042c 0417 0410 0423 0414 ; Control de Desechos Radiactivos en el A.E.R.E., Harwell

Energy Technology Data Exchange (ETDEWEB)

Burns, R. H. [United Kingdom Atomic Energy Authority (United Kingdom)

1960-07-01

The paper outlines the present practices in the control and treatment of radioactive wastes at Harwell. The large-volume, low-level active liquid effluent is treated by phosphate coagulation methods and, eventually, discharged to the River Thames. The medium-level wastes are segregated and undergo a two-stage chemical treatment followed by passage through columns of Vermiculite. The latter process has been found to be effective in removing radoicaesium, which is not dealt with efficiently by the precipitation methods used. Liquid wastes with a high- activity content are stored and a new plant, incorporating chemical treatment, ion exchange and evaporation, is being installed. The chemical sludges formed in the treatment processes are dumped at sea after de-watering by filtration. The contaminated solid waste is either stored or disposed of at sea. It is important to reduce the volume as much as possible and the methods employed include pressure baling, melting and incineration of combustible matter. Small quantities of activity are discharged to the atmosphere through exhaust stacks. The cleaning of this discharge air is commonly achieved by the use of high-efficiency filters or liquid scrubbing systems. Regular stack monitoring is carried out and this is backed up by a comprehensive district sampling programme. (author) [French] L'auteur decrit les methodes de controle et de traitement des dechets radioactifs qui sont appliquees au Centre de Harwell. Le volume considerable des effluents liquides de faible activite est traite par des methodes de coagulation au moyen des phosphates, puis evacue dans la Tamise. Apres separation, les dechets d'activite moyenne sont soumis a un traitement chimique en deux temps, avant de traverser des colonnes de Vermiculite. On a constate que ce dernier processus eliminait le radio- cesium, ce que les methodes de precipitation utilisees ne permettent pas de faire de maniere efficace. Les dechets liquides d'activite intense sont

Injectabilite des coulis de ciment dans des milieux fissures

Science.gov (United States)

Mnif, Thameur

Le travail presente ici est un bilan du travaux de recherche effectues sur l'injectabilite des coulis de ciment dans lu milieux fissures. Un certain nombre de coulis a base de ciment Portland et microfin ont ete selectionnes afin de caracteriser leur capacite a penetrer des milieux fissures. Une partie des essais a ete menee en laboratoire. L'etude rheologique des differents melanges a permis de tester l'influence de l'ajout de superplastifiant et/ou de fumee de silice sur la distribution granulometrique des coulis et par consequent sur leur capacite a injecter des colonnes de sable simulant un milieu fissure donne. La classe granulometrique d'un coulis, sa stabilite et sa fluidite sont apparus comme les trois facteurs principaux pour la reussite d'une injection. Un facteur de finesse a ete defini au cours de cette etude: base sur la classe granulometrique du ciment et sa stabilite, il peut entrer dans la formulation theorique du debit d'injection avant application sur chantier. La deuxieme et derniere partie de l'etude presente les resultats de deux projets de recherche sur l'injection realises sur chantier. L'injection de dalles de beton fissurees a permis le suivi de l'evolution des pressions avec la distance au point d'injection. L'injection de murs de maconnerie a caractere historique a montre l'importance de la definition de criteres de performance des coulis a utiliser pour traiter un milieu donne et pour un objectif donne. Plusieurs melanges peuvent ainsi etre predefinis et mis a disposition sur le chantier. La complementarite des ciments traditionnels et des ciments microfins devient alors un atout important. Le choix d'utilisation de ces melanges est fonction du terrain rencontre. En conclusion, cette recherche etablit une methodologie pour la selection des coulis a base de ciment et des pressions d'injection en fonction de l'ouverture des fissures ou joints de construction.

Ecology of Acantharia and Strontium Circulation in the Sea; Ecologie des Acanthaires et Circulation du Strontium en Mer; 0411 0414 ; Ecologia de los Acantarios y Circulacion del Estroncio en el Mar

Energy Technology Data Exchange (ETDEWEB)

Schreiber, Bruno [Department of Zoology, University of Parma (Italy)

1960-07-01

The author first considers the biochemical cycle of strontium in sea-water and then examines the proposed programme and the objectives it is hoped to achieve. The Acantharia group was selected for this study since it is the only one which has a specific and exclusive deposit of strontium. It is, therefore, of particular interest in relation to the problems concerning the circulation of strontium and radioactive isotopes resulting from fall-out. (author) [French] L'auteur procede d'abord a une etude du cycle bio-chimique du strontium dans l'eau de mer, puis il procede a l'etude du programme envisage et des objectifs poursuivis. Les Acanthaires ont ete choisis pour cette etude car ils constituent le seul groupe possedant un depot de strontium specifique et exclusif. Il est donc particulierement interessant een ce qui concerne les problemes relatifs a la circulation du strontium et des isotopes radioactifs provenant des retombees. (author) [Spanish] El autor estudia primero el ciclo bioquimico del estroncio en las aguas del mar, y procede luego al estudio del programa proyectado y de los objetivos perseguidos. Para realizar este estudio se ha escogido a los acantarios porque su esqueleto contiene estroncio. Por ello, este grupo es de especial interes en lo que respecta a los problemas de la circulacion del estroncio y de los radioisotopos procedentes de las precipitaciones radiactivas. (author) [Russian] Prezhde vsego avtor opisyvaet biohimicheskij cikl stroncija v morskoj vode, a zatem perehodit k rassmotreniju planiruemoj programmy i presleduemyh celej. Dlja jetogo issledovanija byla vybrana akantarija (Acantharia), tak kak ona javljaetsja edinstvennoj gruppoj, imejushhej specificheskie i edinstvennye v svoem rode otlozhenija stroncija. Takim obrazom, ona javljaetsja krajne interesnoj v otnoshenii problem, svjazannyh s cirkuljaciej stroncija i radioaktivnyh izotopov, poluchaemyh v rezul'tate vypadenija osadkov. (author)

Purification by ion exchange resins of the heavy water of the reactors EL 1 and EL 2. A - the purifying process. Equipment and results; Purification par resines echangeuses d'ions de l'eau lourde des reacteurs EL1 et EL2. A - conduite de la purification. Installations et resultats

Energy Technology Data Exchange (ETDEWEB)

Chenouard, J.; Roth, E. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1957-07-01

The heavy water was purified by tapping off part of the moderator over a mixed bed of anion and cation exchangers. The heavy water leaving the columns has a resistivity reaching several-meg-ohms, which allows the resistivity of the moderator to be maintained between 10{sup 5} and 10{sup 6} ohms/cm. Two methods of deuteration of the ion exchangers are described, as well as the heavy water recuperation from resins charged with radioactive products. The influence of the purity of the water on the radiolytic dissociation is investigated. An interpretation of the variations in pH and of the formation of hydrogen peroxide is given. In addition the report contains a general description of the EL1 and EL2 purification installations. (author) [French] L'epuration de l'eau lourde a ete effectuee en derivant une partie du moderateur sur un lit melange d'echangeurs d'anions et de cations. Les colonnes delivrent de l'eau lourde dont la resistivite atteint plusieurs megohms; ceci permet d'entretenir la resistivite du moderateur entre 10{sup 5} et 10{sup 6} ohms/cm. Deux procedes deuteriation des echangeurs d'ions sont decrits de meme que la recuperation de l'eau lourde partir des resines chargees de produits radioactifs. L'influence de la purete de l'eau sur sa dissociation radiolytique est etudiee. Une interpretation est donnee des variations de pH et de la formation d'eau oxygenee. Le rapport comprend en outre une description generale des installations d'epuration de EL1et EL2. (auteur)

La gouvernance des risques naturels et la problematique des ...

African Journals Online (AJOL)

Depuis quelques années, la gouvernance des risques naturels dus aux inondations remet en cause les processus de mise en oeuvre des politiques urbaines et la qualité de la structure des aménagements dans les grandes villes du Golfe de Guinée. La perception de la gouvernance et l'application des politiques de ...

Tropospheric Aerosols

Science.gov (United States)

Buseck, P. R.; Schwartz, S. E.

2003-12-01

It is widely believed that "On a clear day you can see forever," as proclaimed in the 1965 Broadway musical of the same name. While an admittedly beautiful thought, we all know that this concept is only figurative. Aside from Earth's curvature and Rayleigh scattering by air molecules, aerosols - colloidal suspensions of solid or liquid particles in a gas - limit our vision. Even on the clearest day, there are billions of aerosol particles per cubic meter of air.Atmospheric aerosols are commonly referred to as smoke, dust, haze, and smog, terms that are loosely reflective of their origin and composition. Aerosol particles have arisen naturally for eons from sea spray, volcanic emissions, wind entrainment of mineral dust, wildfires, and gas-to-particle conversion of hydrocarbons from plants and dimethylsulfide from the oceans. However, over the industrial period, the natural background aerosol has been greatly augmented by anthropogenic contributions, i.e., those produced by human activities. One manifestation of this impact is reduced visibility (Figure 1). Thus, perhaps more than in other realms of geochemistry, when considering the composition of the troposphere one must consider the effects of these activities. The atmosphere has become a reservoir for vast quantities of anthropogenic emissions that exert important perturbations on it and on the planetary ecosystem in general. Consequently, much recent research focuses on the effects of human activities on the atmosphere and, through them, on the environment and Earth's climate. For these reasons consideration of the geochemistry of the atmosphere, and of atmospheric aerosols in particular, must include the effects of human activities. (201K)Figure 1. Impairment of visibility by aerosols. Photographs at Yosemite National Park, California, USA. (a) Low aerosol concentration (particulate matter of aerodynamic diameter less than 2.5 μm, PM2.5=0.3 μg m-3; particulate matter of aerodynamic diameter less than 10 �

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the UK

Science.gov (United States)

McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

2011-05-01

Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the UK. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA observed in

DSMC multicomponent aerosol dynamics: Sampling algorithms and aerosol processes

Science.gov (United States)

Palaniswaamy, Geethpriya

The post-accident nuclear reactor primary and containment environments can be characterized by high temperatures and pressures, and fission products and nuclear aerosols. These aerosols evolve via natural transport processes as well as under the influence of engineered safety features. These aerosols can be hazardous and may pose risk to the public if released into the environment. Computations of their evolution, movement and distribution involve the study of various processes such as coagulation, deposition, condensation, etc., and are influenced by factors such as particle shape, charge, radioactivity and spatial inhomogeneity. These many factors make the numerical study of nuclear aerosol evolution computationally very complicated. The focus of this research is on the use of the Direct Simulation Monte Carlo (DSMC) technique to elucidate the role of various phenomena that influence the nuclear aerosol evolution. In this research, several aerosol processes such as coagulation, deposition, condensation, and source reinforcement are explored for a multi-component, aerosol dynamics problem in a spatially homogeneous medium. Among the various sampling algorithms explored the Metropolis sampling algorithm was found to be effective and fast. Several test problems and test cases are simulated using the DSMC technique. The DSMC results obtained are verified against the analytical and sectional results for appropriate test problems. Results show that the assumption of a single mean density is not appropriate due to the complicated effect of component densities on the aerosol processes. The methods developed and the insights gained will also be helpful in future research on the challenges associated with the description of fission product and aerosol releases.

Estimation of Uncertainty in Aerosol Concentration Measured by Aerosol Sampling System

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Chan; Song, Yong Jae; Jung, Woo Young; Lee, Hyun Chul; Kim, Gyu Tae; Lee, Doo Yong [FNC Technology Co., Yongin (Korea, Republic of)

2016-10-15

FNC Technology Co., Ltd has been developed test facilities for the aerosol generation, mixing, sampling and measurement under high pressure and high temperature conditions. The aerosol generation system is connected to the aerosol mixing system which injects SiO{sub 2}/ethanol mixture. In the sampling system, glass fiber membrane filter has been used to measure average mass concentration. Based on the experimental results using main carrier gas of steam and air mixture, the uncertainty estimation of the sampled aerosol concentration was performed by applying Gaussian error propagation law. FNC Technology Co., Ltd. has been developed the experimental facilities for the aerosol measurement under high pressure and high temperature. The purpose of the tests is to develop commercial test module for aerosol generation, mixing and sampling system applicable to environmental industry and safety related system in nuclear power plant. For the uncertainty calculation of aerosol concentration, the value of the sampled aerosol concentration is not measured directly, but must be calculated from other quantities. The uncertainty of the sampled aerosol concentration is a function of flow rates of air and steam, sampled mass, sampling time, condensed steam mass and its absolute errors. These variables propagate to the combination of variables in the function. Using operating parameters and its single errors from the aerosol test cases performed at FNC, the uncertainty of aerosol concentration evaluated by Gaussian error propagation law is less than 1%. The results of uncertainty estimation in the aerosol sampling system will be utilized for the system performance data.

A Solution for the Storage of Radioactive Sludge in the Ground at Marcoule; Une Solution de Stockage dans le Sol des Boues Radioactives de Marcoule; 0420 0415 0428 0414 ; Solucion para el Almacenamiento de Lodos Radiactivos en el Suelo de Marcoule

Energy Technology Data Exchange (ETDEWEB)

Cohen, P.; Gailledreau, C. [Service de Controle des Radiations et de Genie Radioactif, Commissariat a L' Energie Atomique, Saclay (France)

1960-07-01

This paper deals with radioactive sludge from the radioactive effluents of the plant at Marcoule. The sludge is stored in drums, and the authors have investigated the hazard created at Marcoule by the seepage of this radioactive sludge through the soil with the gradual deterioration of the drums. This economic solution may be applicable in certain cases. (author) [French] Il s'agit de boues radioactives en provenance de la station des effluents radioactifs de Marcoule: ces boues sont stockees dans des futs, et nous avons etudie le danger presente par la percolation a travers le sol de Marcoule de ces boues radioactives apres degradation progressive du fut. Cette solution economique peut etre applicable dans certains cas. (author) [Spanish] Se trata de los lodos radiactivos procedentes de la estacion de efluentes radiactivos de Marcoule: los lodos se depositan en toneles, y el autor ha estudiado el peligro que ofrece la infiltracion de los lodos radiactivos a traves del suelo de Marcoule a causa del deterioro progresivo del tonel. Esta solucion economica se puede aplicar en determinados casos. (author) [Russian] V dannom doklade rassmatrivajutsja radioaktivnye grjazi, ishodjashhie iz stancii radioaktivnyh zhidkih othodov v Markule. Jeti grjazi zahoronjajutsja v cisternah; v svjazi s jetim izuchalas' opasnost', vyzyvaemaja perkoljaciej cherez pochvu Markulja jetih radioaktivnyh grjazej posle postepennoj porchi cistern. Jeto jekonomicheskoe reshenie mozhet primenjat'sja v otdel'nyh sotuchajah. (author)

Security problems arising from the use of radioactive sources in the study of the wear in refractory linings; Les problemes de securite dans l'emploi de sources radioactives pour l'etude de l'usure de revetements refractaires

Energy Technology Data Exchange (ETDEWEB)

Courtois, G; Hours, R; Le Clerc, P; Pons, A [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The determination of the wear in refractories is a problem to which these are at present only a few solutions, and these limited or delicate to use. That is the reason why the use of radioactive tracers contained in the refractory has met with rapid success. Unfortunately, the development of the method has been retarded by the need to limit severely the amounts of radioelement incorporated and also by the observation that diffusion of the radioactive product occurred in the refractory. As a result, the limiting amount of 1 mc/500 metric tons of cast-iron has been adopted in France, with the proviso that no single source exceeds 3 mc. Further, we have made special sources with a view to avoiding diffusion phenomena. The essential feature of these sources is that they use pyro-ceramic a non porous material having a high melting point and being, very inert chemically. In these sources, the radioelement can either be entirely encased in the pyro-ceramic or be an integral part of its composition. A comparative study of the two types of sources is actually under way. (author) [French] La determination de l'usure des refractaires est un probleme dont les solutions sont jusqu'a maintenant peu nombreuses, limitees ou delicates d'emploi. C'est pour cela que l'utilisation de traceurs radioactifs noyes dans le refractaire a connu un vif succes. Malheureusement, le developpement de la methode a ete freine par la necessite de limiter severement la teneur des radioelements incorpores aux produits metallurgiques et egalement par des constatations de diffusion dans le refractaire du produit radioactif. Par suite, la teneur limite de 1 mc/500 tonnes de fonte est maintenant adoptee en France, sans qu'une source individuelle puisse depasser 3 mc. De plus, nous avons realise des sources particulierement etudiees en vue d'eviter des phenomenes de diffusion. Le caractere essentiel de cette realisation est l'utilisation de pyrocerame, materiau non poreux, a haut point de fusion et de

Aerosol and monsoon climate interactions over Asia: AEROSOL AND MONSOON CLIMATE INTERACTIONS

Energy Technology Data Exchange (ETDEWEB)

Li, Zhanqing [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Lau, W. K. -M. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Ramanathan, V. [Department of Atmospheric and Climate Sciences, University of California, San Diego California USA; Wu, G. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Ding, Y. [National Climate Center, China Meteorological Administration, Beijing China; Manoj, M. G. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Liu, J. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Qian, Y. [Pacific Northwest National Laboratory, Richland Washington USA; Li, J. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Zhou, T. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Fan, J. [Pacific Northwest National Laboratory, Richland Washington USA; Rosenfeld, D. [Institute of Earth Sciences, Hebrew University, Jerusalem Israel; Ming, Y. [Geophysical Fluid Dynamic Laboratory, NOAA, Princeton New Jersey USA; Wang, Y. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena California USA; Huang, J. [College of Atmospheric Sciences, Lanzhou University, Lanzhou China; Wang, B. [Department of Atmospheric Sciences, University of Hawaii, Honolulu Hawaii USA; School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing China; Xu, X. [Chinese Academy of Meteorological Sciences, Beijing China; Lee, S. -S. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Cribb, M. [Department of Atmospheric and Oceanic Science and ESSIC, University of Maryland, College Park Maryland USA; Zhang, F. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Yang, X. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Zhao, C. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Takemura, T. [Research Institute for Applied Mechanics, Kyushu University, Fukuoka Japan; Wang, K. [State Key Laboratory of Earth Surface Processes and Resource Ecology and College of Global Change and Earth System Science, Beijing Normal University, Beijing China; Xia, X. [Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing China; Yin, Y. [School of Atmospheric Physics, Nanjing University of Information Science and Technology, Nanjing China; Zhang, H. [National Climate Center, China Meteorological Administration, Beijing China; Guo, J. [Chinese Academy of Meteorological Sciences, Beijing China; Zhai, P. M. [Chinese Academy of Meteorological Sciences, Beijing China; Sugimoto, N. [National Institute for Environmental Studies, Tsukuba Japan; Babu, S. S. [Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram India; Brasseur, G. P. [Max Planck Institute for Meteorology, Hamburg Germany

2016-11-15

Asian monsoons and aerosols have been studied extensively which are intertwined in influencing the climate of Asia. This paper provides a comprehensive review of ample studies on Asian aerosol, monsoon and their interactions. The region is the primary source of aerosol emissions of varies species, influenced by distinct weather and climatic regimes. On continental scale, aerosols reduce surface insolation and weaken the land-ocean thermal contrast, thus inhibiting the development of monsoons. Locally, aerosol radiative effects alter the thermodynamic stability and convective potential of the lower atmosphere leading to reduced temperatures, increased atmospheric stability, and weakened wind and atmospheric circulation. The atmospheric thermodynamic state may also be altered by the aerosol serving as cloud condensation nuclei or ice nuclei. Many mechanisms have been put forth regarding how aerosols modulate the amplitude, frequency, intensity, and phase of numerous monsoon climate variables. A wide range of theoretical, observational, and modeling findings on the Asian monsoon, aerosols, and their interactions are synthesized. A new paradigm is proposed on investigating aerosol-monsoon interactions, in which natural aerosols such as desert dust, black carbon from biomass burning, and biogenic aerosols from vegetation are considered integral components of an intrinsic aerosol-monsoon climate system, subject to external forcings of global warming, anthropogenic aerosols, and land use and change. Future research on aerosol-monsoon interactions calls for an integrated approach and international collaborations based on long-term sustained observations, process measurements, and improved models, as well as using observations to constrain model simulations and projections.

The aerosols and the greenhouse effect; Aerosoler og klimaeffekten

Energy Technology Data Exchange (ETDEWEB)

Iversen, Trond; Kirkevaag, Alf; Seland, Oeyvind; Debernard, Jens Boldingh; Kristjansson, Jon Egill; Storelvmo, Trude

2008-07-01

The article discussed the aerosol effects on the climatic changes and points out that the climate models do not incorporate these components satisfactorily mostly due to insufficient knowledge of the aerosol pollution sources. The direct and indirect effects of aerosols are mentioned as well as the climate response (tk)

EFFET DES TRAITEMENTS THERMIQUES SUR LA REACTION ENTRE DES COUCHES MINCES DE TITANE ET DES SUBSTRATS EN ACIER

Directory of Open Access Journals (Sweden)

D Slimani

2015-06-01

Full Text Available Des couches minces du titane pur ont été déposées avec la méthode de pulvérisation cathodique sur des substrats en acier, type FF80 K-1 contenants ~1% mass. en carbone. La réaction entre les deux parties du système substrat-couche mince est activée avec des traitements thermiques sous vide dans l’intervalle de températures de 400 à900°Cpendant 30 minutes. Les Spectres de diffraction de rayons x confirment l’inter- diffusion des éléments  chimiques du système résultants la formation et la croissance des nouvelles phases en particulier le carbure binaire TiC ayant des caractéristiques thermomécaniques importantes. L’analyse morphologique des échantillons traités  avec le microscope électronique à balayage (MEB montre l’augmentation du flux de diffusion atomique avec la température de recuit, notamment la diffusion du manganèse et du fer vers la surface libre des échantillons aux températures élevées provoquant la dégradation des propriétés mécaniques des revêtements contrairement au premiers stades d’interaction où on a obtenu des bonnes valeurs de la microdureté.

Promouvoir l'entrepreneuriat inclusif des jeunes et des femmes ...

International Development Research Centre (IDRC) Digital Library (Canada)

Le projet vise à analyser la contribution réelle et potentielle de l'entrepreneuriat inclusif au bien-être des jeunes et des femmes en Côte d'Ivoire, au Burkina Faso et au Kenya. Après un état des lieux de la pratique de l'entrepreneuriat inclusif dans chacun des pays ciblés, l'équipe de recherche étudiera son incidence sur ...

Industrial long-term waste management in France

International Nuclear Information System (INIS)

Marque, Y.

1988-01-01

Long-term industrial management of radioactive waste in France is carried out by the Agence Nationale pour la Gestion des Dechets Radioactifs (ANDRA). ANDRA is in charge of design, siting, construction and operation of disposal centers. The French national program of waste management is running on with the construction of a second near-surface disposal which is expected to be in operation in 1991 and a selection of a site for the construction of an underground laboratory for the qualification of this site for deep disposal

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

Science.gov (United States)

McMeeking, G. R.; Morgan, W. T.; Flynn, M.; Highwood, E. J.; Turnbull, K.; Haywood, J.; Coe, H.

2011-09-01

Black carbon (BC) aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2) measurements of refractory BC (rBC) mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA) operated by the Facility for Airborne Atmospheric Measurements (FAAM). We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS) and used positive matrix factorization to separate hydrocarbon-like (HOA) and oxygenated organic aerosols (OOA). We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NOx) ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NOx and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA) did change for different air masses, with lower SSA

Black carbon aerosol mixing state, organic aerosols and aerosol optical properties over the United Kingdom

Directory of Open Access Journals (Sweden)

G. R. McMeeking

2011-09-01

Full Text Available Black carbon (BC aerosols absorb sunlight thereby leading to a positive radiative forcing and a warming of climate and can also impact human health through their impact on the respiratory system. The state of mixing of BC with other aerosol species, particularly the degree of internal/external mixing, has been highlighted as a major uncertainty in assessing its radiative forcing and hence its climate impact, but few in situ observations of mixing state exist. We present airborne single particle soot photometer (SP2 measurements of refractory BC (rBC mass concentrations and mixing state coupled with aerosol composition and optical properties measured in urban plumes and regional pollution over the United Kingdom. All data were obtained using instrumentation flown on the UK's BAe-146-301 large Atmospheric Research Aircraft (ARA operated by the Facility for Airborne Atmospheric Measurements (FAAM. We measured sub-micron aerosol composition using an aerosol mass spectrometer (AMS and used positive matrix factorization to separate hydrocarbon-like (HOA and oxygenated organic aerosols (OOA. We found a higher number fraction of thickly coated rBC particles in air masses with large OOA relative to HOA, higher ozone-to-nitrogen oxides (NO_x ratios and large concentrations of total sub-micron aerosol mass relative to rBC mass concentrations. The more ozone- and OOA-rich air masses were associated with transport from continental Europe, while plumes from UK cities had higher HOA and NO_x and fewer thickly coated rBC particles. We did not observe any significant change in the rBC mass absorption efficiency calculated from rBC mass and light absorption coefficients measured by a particle soot absorption photometer despite observing significant changes in aerosol composition and rBC mixing state. The contributions of light scattering and absorption to total extinction (quantified by the single scattering albedo; SSA did change for

Characterization of urban aerosol in Cork city (Ireland) using aerosol mass spectrometry

Science.gov (United States)

Dall'Osto, M.; Ovadnevaite, J.; Ceburnis, D.; Martin, D.; Healy, R. M.; O'Connor, I. P.; Kourtchev, I.; Sodeau, J. R.; Wenger, J. C.; O'Dowd, C.

2013-05-01

Ambient wintertime background urban aerosol in Cork city, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the ca. 1 350 000 single particles characterized by an Aerosol Time-of-Flight Mass Spectrometer (TSI ATOFMS) were classified into five organic-rich particle types, internally mixed to different proportions with elemental carbon (EC), sulphate and nitrate, while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was characterized using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS) and was also found to comprise organic aerosol as the most abundant species (62%), followed by nitrate (15%), sulphate (9%) and ammonium (9%), and chloride (5%). Positive matrix factorization (PMF) was applied to the HR-ToF-AMS organic matrix, and a five-factor solution was found to describe the variance in the data well. Specifically, "hydrocarbon-like" organic aerosol (HOA) comprised 20% of the mass, "low-volatility" oxygenated organic aerosol (LV-OOA) comprised 18%, "biomass burning" organic aerosol (BBOA) comprised 23%, non-wood solid-fuel combustion "peat and coal" organic aerosol (PCOA) comprised 21%, and finally a species type characterized by primary {m/z} peaks at 41 and 55, similar to previously reported "cooking" organic aerosol (COA), but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Correlations between the different particle types obtained by the two aerosol mass spectrometers are also discussed. Despite wood, coal and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosol mass and non-refractory total PM1, respectively).

Characterization of urban aerosol in Cork city (Ireland using aerosol mass spectrometry

Directory of Open Access Journals (Sweden)

M. Dall'Osto

2013-05-01

Full Text Available Ambient wintertime background urban aerosol in Cork city, Ireland, was characterized using aerosol mass spectrometry. During the three-week measurement study in 2009, 93% of the ca. 1 350 000 single particles characterized by an Aerosol Time-of-Flight Mass Spectrometer (TSI ATOFMS were classified into five organic-rich particle types, internally mixed to different proportions with elemental carbon (EC, sulphate and nitrate, while the remaining 7% was predominantly inorganic in nature. Non-refractory PM1 aerosol was characterized using a High Resolution Time-of-Flight Aerosol Mass Spectrometer (Aerodyne HR-ToF-AMS and was also found to comprise organic aerosol as the most abundant species (62%, followed by nitrate (15%, sulphate (9% and ammonium (9%, and chloride (5%. Positive matrix factorization (PMF was applied to the HR-ToF-AMS organic matrix, and a five-factor solution was found to describe the variance in the data well. Specifically, "hydrocarbon-like" organic aerosol (HOA comprised 20% of the mass, "low-volatility" oxygenated organic aerosol (LV-OOA comprised 18%, "biomass burning" organic aerosol (BBOA comprised 23%, non-wood solid-fuel combustion "peat and coal" organic aerosol (PCOA comprised 21%, and finally a species type characterized by primary extit{m/z}~peaks at 41 and 55, similar to previously reported "cooking" organic aerosol (COA, but possessing different diurnal variations to what would be expected for cooking activities, contributed 18%. Correlations between the different particle types obtained by the two aerosol mass spectrometers are also discussed. Despite wood, coal and peat being minor fuel types used for domestic space heating in urban areas, their relatively low combustion efficiencies result in a significant contribution to PM1 aerosol mass (44% and 28% of the total organic aerosol mass and non-refractory total PM1, respectively.

Estimating marine aerosol particle volume and number from Maritime Aerosol Network data

Directory of Open Access Journals (Sweden)

A. M. Sayer

2012-09-01

Full Text Available As well as spectral aerosol optical depth (AOD, aerosol composition and concentration (number, volume, or mass are of interest for a variety of applications. However, remote sensing of these quantities is more difficult than for AOD, as it is more sensitive to assumptions relating to aerosol composition. This study uses spectral AOD measured on Maritime Aerosol Network (MAN cruises, with the additional constraint of a microphysical model for unpolluted maritime aerosol based on analysis of Aerosol Robotic Network (AERONET inversions, to estimate these quantities over open ocean. When the MAN data are subset to those likely to be comprised of maritime aerosol, number and volume concentrations obtained are physically reasonable. Attempts to estimate surface concentration from columnar abundance, however, are shown to be limited by uncertainties in vertical distribution. Columnar AOD at 550 nm and aerosol number for unpolluted maritime cases are also compared with Moderate Resolution Imaging Spectroradiometer (MODIS data, for both the present Collection 5.1 and forthcoming Collection 6. MODIS provides a best-fitting retrieval solution, as well as the average for several different solutions, with different aerosol microphysical models. The "average solution" MODIS dataset agrees more closely with MAN than the "best solution" dataset. Terra tends to retrieve lower aerosol number than MAN, and Aqua higher, linked with differences in the aerosol models commonly chosen. Collection 6 AOD is likely to agree more closely with MAN over open ocean than Collection 5.1. In situations where spectral AOD is measured accurately, and aerosol microphysical properties are reasonably well-constrained, estimates of aerosol number and volume using MAN or similar data would provide for a greater variety of potential comparisons with aerosol properties derived from satellite or chemistry transport model data. However, without accurate AOD data and prior knowledge of

Measurement of the activity of beta emitting gases using an ionisation chamber; Mesure de l'activite des gaz emetteurs beta au moyen d'une chambre d'ionisation

Energy Technology Data Exchange (ETDEWEB)

Lebouleux, P [Commissariat a l' Energie Atomique. Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

1962-07-01

An ionization chamber was developed for measuring directly the activity of a {beta}-emitting gas whatever the gas may be. The following two parameters are defined and determined: p, the average specific ionization produced by a {beta} disintegration, and i, the average {beta} path in the chamber. It was shown, during the determination of i, that the {beta} particles are reflected on the walls of the ionization chamber when the latter are made of a high atomic number material. It was possible to eliminate this effect by constructing an electrode chamber made of graphite. With this chamber a direct measurement can be made of the activity of a gaseous {beta} emitter with a precision of about {+-}10%. Some applications are given of the graphite electrode chamber (calibration of the chambers built industrially and determination of the activation cross section of a gaseous emitter). It was possible to determine the activation cross section of {sup 134}Xe; a value of 0.18 {+-} 0.03 barn was found. (author) [French] Le but de l'etude est de realiser une chambre d'ionisation permettant d'effectuer une mesure directe de l'activite d'un gaz emetteur {beta} quel que soit l'emetteur considere. On definit et l'on determine les deux parametres suivants: p: ionisation specifique moyenne produite par une desintegration {beta}. La determination est effectuee par une methode graphique, i: moyenne des parcours des {beta} dans la chambre. La determination est effectuee experimentalement par introduction dans la chambre d'un gaz radioactif dont on peut calculer l'activite. On a mis en evidence, au cours de la determination de i, la reflexion des particules {beta} sur les parois des chambres d'ionisation lorsque celles-ci sont constituees d'un materiau de numero atomique eleve. La construction d'une chambre a electrodes de graphite nous a permis d'eliminer ce phenomene. Avec cette chambre, on effectue une mesure directe de l'activite d'un emetteur {beta} gazeux avec une precision de l

Prise en charge des urgences au service d'accueil des urgences ...

African Journals Online (AJOL)

Introduction: La prise en charge des patients dans les services d'accueil des urgences est une des meilleures vitrines d'un système de santé. En Afrique subsaharienne, la gestion des urgences se heurte à des difficultés humaines et matérielles. Le but de ce travail était d'évaluer les difficultés de prise en charge au Service ...

Connaissances, attitudes et pratiques des prestataires de santé des ...

African Journals Online (AJOL)

... des prestataires interrogés avaient respectivement une bonne connaissance des facteurs de risque et des moyens de dépistage. Les signes évocateurs et les examens complémentaires nécessaires au diagnostic du cancer du sein étaient connus par 15,3 % des prestataires. La définition du cancer du sein et les moyens ...

Radioactive aerosols

International Nuclear Information System (INIS)

Chamberlain, A.C.

1991-01-01

Radon. Fission product aerosols. Radioiodine. Tritium. Plutonium. Mass transfer of radioactive vapours and aerosols. Studies with radioactive particles and human subjects. Index. This paper explores the environmental and health aspects of radioactive aerosols. Covers radioactive nuclides of potential concern to public health and applications to the study of boundary layer transport. Contains bibliographic references. Suitable for environmental chemistry collections in academic and research libraries

Usages des TIC et socialisation professionnelle des enseignants-chercheurs

OpenAIRE

Lavielle-Gutnik, Nathalie; Massou, Luc

2013-01-01

En prenant appui sur une nouvelle analyse des données recueillies dans l’enquête Tec-Meus (2008-2011, MSH Lorraine) sur la place accordée par des enseignants-chercheurs en sciences humaines et sociales aux technologies de l’information et de la communication (TIC) dans leur activité d’enseignement, nous souhaitons nous focaliser dans cet article sur la compréhension des processus de socialisation professionnelle en jeu dans leur usage déclaré des TIC. Par socialisation professionnelle, nous e...

Evaluer des études de gestion des entreprises : combiner des éléments principales avec des éléments pratiques

NARCIS (Netherlands)

Pennink, B.J.W.

2002-01-01

Evaluer la recherche de gestion demande une combinaison des critères classiques et des critères pratiques. Par cette combinaison il est possible de trouver une réponse cerrecte concernant la validité et l'effet de la recherche. Dans cet article nous allons décrire comment une combinaison des

Aspects des Onychomycoses chez des patients camerounais de ...

African Journals Online (AJOL)

... biologiques et évolutifs des onychomycoses chez des patients camerounais. Méthode : Il s'agit d'une étude rétrospective et descriptive menée de mars 2011 à mars 2014 dans l'unité de dermatologie de l'hôpital général de Douala (HGD), incluant des patients chez lesquels le diagnostic d'onychomycose avait été posé.

Aerosol studies

International Nuclear Information System (INIS)

Cristy, G.A.; Fish, M.E.

1978-01-01

As part of the continuing studies of the effects of very severe reactor accidents, an effort was made to develop, test, and improve simple, effective, and inexpensive methods by which the average citizen, using only materials readily available, could protect his residence, himself, and his family from injury by toxic aerosols. The methods for protection against radioactive aerosols should be equally effective against a clandestine biological attack by terrorists. The results of the tests to date are limited to showing that spores of the harmless bacterium, bacillus globegii (BG), can be used as a simulant for the radioactive aerosols. An aerosol generator of Lauterbach type was developed which will produce an essentially monodisperse aerosol at the rate of 10 9 spores/min. Analytical techniques have been established which give reproducible results. Preliminary field tests have been conducted to check out the components of the system. Preliminary tests of protective devices, such as ordinary vacuum sweepers, have given protection factors of over 1000

Aerosol Climate Time Series in ESA Aerosol_cci

Science.gov (United States)

Popp, Thomas; de Leeuw, Gerrit; Pinnock, Simon

2016-04-01

Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. Meanwhile, full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer, but also from ATSR instruments and the POLDER sensor), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which were also validated and improved in the reprocessing. For the three ATSR algorithms the use of an ensemble method was tested. The paper will summarize and discuss the status of dataset reprocessing and validation. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension

Contribution to the detection of radioactivity as applied to regular testing and to protection; Contribution a la detection des rayonnements en vue du controle et de la protection

Energy Technology Data Exchange (ETDEWEB)

Fuhrmann,; Joffre,; Savouyaud, [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

1. The equipment which is at the disposal of teams carrying out tests, such as the Radiations Analysis section and the Radtivity Engineers section at the CEA, has been developed from apparatus designed for laboratory research. The result of this is that even when attempts have been made to make this equipment more robust and manageable, no effort has been made to adapt the equipment to exactly what is required for assuring protection against radioactivity. It has therefore been necessary for this section to exactly specify its requirements and to carry out itself a part of the work required for developing the most suitable material. 2. The most important problems concerned the analysis of the radioactivity and the fabrication of electronic equipment, which could be available cheaply on a large scale and be also as far as possible self supporting. 3. In the present paper we briefly describe our contribution to this subject and in particular: - the improvement of methods of {gamma} ray analysis which use photographic films; - the try out of a simple and cheap technique for the analysis and spectrography of {alpha} particles; - the utilisation of new electronic material: ionisation chamber counters, scintillators; - the development of special equipment for measuring the mean flux of particles which are emitted periodically in very short bursts. (author)Fren. [French] 1. Le materiel qui se trouve a la disposition des organismes de controle, tel le Service de Controle des Radiations et de Genie Radioactif au Commissariat a l'Energie Atomique, a ete concu a partir de materiels realises pour des experiences de laboratoire et, meme lorsqu'on a pense a le rendre plus robuste et plus maniable, on a generalement omis de l'adapter exactement aux besoins de la protection contre les radiations. Aussi ce Service a-t-il ete amene a preciser exactement ses besoins et a realiser lui-meme une partie des etudes necessaires a la mise au point d'un materiel mieux adapte. 2. Les

Architecture, des normes et des systèmes d'information libres, phase ...

International Development Research Centre (IDRC) Digital Library (Canada)

Architecture, des normes et des systèmes d'information libres, phase II (OASIS II) - Renforcement des capacités dans l'ensemble de l'Afrique. Sur presque tout le continent africain, la prestation des services de santé est limitée en raison des maigres ressources disponibles et de la charge de morbidité de plus en plus ...

MATRIX-VBS Condensing Organic Aerosols in an Aerosol Microphysics Model

Science.gov (United States)

Gao, Chloe Y.; Tsigaridis, Konstas; Bauer, Susanne E.

2015-01-01

The condensation of organic aerosols is represented in a newly developed box-model scheme, where its effect on the growth and composition of particles are examined. We implemented the volatility-basis set (VBS) framework into the aerosol mixing state resolving microphysical scheme Multiconfiguration Aerosol TRacker of mIXing state (MATRIX). This new scheme is unique and advances the representation of organic aerosols in models in that, contrary to the traditional treatment of organic aerosols as non-volatile in most climate models and in the original version of MATRIX, this new scheme treats them as semi-volatile. Such treatment is important because low-volatility organics contribute significantly to the growth of particles. The new scheme includes several classes of semi-volatile organic compounds from the VBS framework that can partition among aerosol populations in MATRIX, thus representing the growth of particles via condensation of low volatility organic vapors. Results from test cases representing Mexico City and a Finish forrest condistions show good representation of the time evolutions of concentration for VBS species in the gas phase and in the condensed particulate phase. Emitted semi-volatile primary organic aerosols evaporate almost completely in the high volatile range, and they condense more efficiently in the low volatility range.

L'exode des cerveaux et le renforcement des capacités en Afrique ...

International Development Research Centre (IDRC) Digital Library (Canada)

1 févr. 2011 ... Ce phénomène ébranle les assises économiques et politiques de bien des pays africains. ... le défi consiste à recruter ces cerveaux. ... des missions africaines, des organisations non gouvernementales et des groupes de la diaspora réunis pour parler de l'exode des cerveaux en Afrique et des stratégies à ...

Contribution to the study of maximum levels for liquid radioactive waste disposal into continental and sea water. Treatment of some typical samples; Contribution a l'etude des niveaux limites relatifs a des rejets d'effluents radioactifs liquides dans les eaux continentales et oceaniques. Traitement de quelques exemples types

Energy Technology Data Exchange (ETDEWEB)

Bittel, R; Mancel, J [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires, departement de la protection sanitaire

1968-10-01

The most important carriers of radioactive contamination of man are the whole of foodstuffs and not only ingested water or inhaled air. That is the reason why, in accordance with the spirit of the recent recommendations of the ICRP, it is proposed to substitute the idea of maximum levels of contamination of water to the MPC. In the case of aquatic food chains (aquatic organisms and irrigated foodstuffs), the knowledge of the ingested quantities and of the concentration factors food/water permit to determinate these maximum levels, or to find out a linear relation between the maximum levels in the case of two primary carriers of contamination (continental and sea waters). The notion of critical food-consumption, critical radioelements and formula of waste disposal are considered in the same way, taking care to attach the greatest possible importance to local situations. (authors) [French] Les vecteurs essentiels de la contamination radioactive de l'homme sont les aliments dans leur ensemble, et non seulement l'eau ingeree ou l'air inhale. C'est pourquoi, en accord avec l'esprit des recentes recommandations de la C.I.P.R., il est propose de substituer aux CMA la notion de niveaux limites de contamination des eaux. Dans le cas des chaines alimentaires aquatiques (organismes aquatiques et aliments irrigues), la connaissance des quantites ingerees et celle des facteurs de concentration aliments/eau permettent de determiner ces niveaux limites dans le cas de deux vecteurs primaires de contamination (eaux continentales et eaux oceaniques). Les notions de regime alimentaire critique, de radioelement critique et de formule de rejets sont envisagees, dans le meme esprit, avec le souci de tenir compte le plus possible des situations locales. (auteurs)

Aerosol Climate Time Series Evaluation In ESA Aerosol_cci

Science.gov (United States)

Popp, T.; de Leeuw, G.; Pinnock, S.

2015-12-01

Within the ESA Climate Change Initiative (CCI) Aerosol_cci (2010 - 2017) conducts intensive work to improve algorithms for the retrieval of aerosol information from European sensors. By the end of 2015 full mission time series of 2 GCOS-required aerosol parameters are completely validated and released: Aerosol Optical Depth (AOD) from dual view ATSR-2 / AATSR radiometers (3 algorithms, 1995 - 2012), and stratospheric extinction profiles from star occultation GOMOS spectrometer (2002 - 2012). Additionally, a 35-year multi-sensor time series of the qualitative Absorbing Aerosol Index (AAI) together with sensitivity information and an AAI model simulator is available. Complementary aerosol properties requested by GCOS are in a "round robin" phase, where various algorithms are inter-compared: fine mode AOD, mineral dust AOD (from the thermal IASI spectrometer), absorption information and aerosol layer height. As a quasi-reference for validation in few selected regions with sparse ground-based observations the multi-pixel GRASP algorithm for the POLDER instrument is used. Validation of first dataset versions (vs. AERONET, MAN) and inter-comparison to other satellite datasets (MODIS, MISR, SeaWIFS) proved the high quality of the available datasets comparable to other satellite retrievals and revealed needs for algorithm improvement (for example for higher AOD values) which were taken into account for a reprocessing. The datasets contain pixel level uncertainty estimates which are also validated. The paper will summarize and discuss the results of major reprocessing and validation conducted in 2015. The focus will be on the ATSR, GOMOS and IASI datasets. Pixel level uncertainties validation will be summarized and discussed including unknown components and their potential usefulness and limitations. Opportunities for time series extension with successor instruments of the Sentinel family will be described and the complementarity of the different satellite aerosol products

Influence de l'occupation des terres sur la dynamique des ...

African Journals Online (AJOL)

L'objectif de la présente étude est d'évaluer l'impact de mise en culture, des pâturages, des jachères et l'influence des villages sur la dynamique des communautés végétales de la commune de ..... mais il n'y a que peu de recrutement. Au-delà de cinq ans, taille et phytovolume diminuent, témoignant du vieillissement de la ...

Underground storage. Study of radwaste storage in deep geological formations: environmental protection

International Nuclear Information System (INIS)

Hoorelbeke, J.M.

1993-01-01

The purpose of the Agence nationale pour la gestion des dechets radioactifs (Andra) is to monitor the management methods and storage of radioactive waste produced in France. The agency has this undertaken a vast study program for the evaluation of the management conditions of long-life radwaste, which cannot be stored indefinitely in shallow-ground repositories. Underground laboratories are investigating the feasibility of a possible solution which is to store radwaste in a deep geological layer. However, there will be no decision on this type of storage before the year 2006. 7 figs

Caesium absorption by barley - influence of its retention by the soil - competitive action of potassium; Absorption du cesium par l'orge - influence de sa retention dans le sol - action competitive du potassium

Energy Technology Data Exchange (ETDEWEB)

Ferron-Trosseau, F [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-06-01

as rice and cress growing on flooded soils. Radio-active caesium however incorporated without carrier into a soil of medium-exchange capacity (of about 150 milli-equivalents per kilo) presents relatively little danger because of the close interdependence of the radioactive caesium take-up from the soil by the plants and its retention by the soil. Our research has made it possible furthermore to examine the value of various partial decontamination methods for soils proposed by certain atomic scientists: just as isotopic dilution appears totally inadequate for this purpose, so does it seems that the addition of potassium salts in amounts greater than nutritive optimum is incapable of reducing the absorption of radioactive caesium by the plant. (author) [French] Nous avons recherche, dans divers milieux de culture, comment l'absorption du cesium par l'orge varie avec sa concentration et comment cette absorption peut etre concurrencee par un cation alcalin voisin,le potassium. En outre, nous avons considere la distribution du cesium dans le sol - notamment du cesium radioactif - entre terre et solution, en fonction du taux de cesium. De notre etude ressort une nette opposition entre le comportement de l'orge vis a vis du cesium d'une solution nutritive et vis a vis du cesium d'un sol: sur solution nutritive, la fraction du cesium (radioactif et stable) absorbee par l'orge demeure pratiquement constante en presence de proportions croissantes (relativement petites) de cesium stable; sur sol, la fraction du cesium radioactif absorbee par l'orge a augmente en meme temps que le taux (relativement petit) de cesium stable du sol, en relation avec une selectivite rapidement decroissante du sol pour Cs. La difference entre ces resultats est donc expliquee par une tres forte selectivite du sol illitique experimente pour Cs{sup +} tant que la proportion da cesium reste tres petite, de l'ordre de celle de la plupart des sols naturels. Par ailleurs, l'ion K{sup +} n'a concurrence l

Liquid aerosol filtration by fibrous filters in interception and inertial regimes; Filtration des aerosols liquides par les filtres a fibres en regimes d`interception et d`inertie

Energy Technology Data Exchange (ETDEWEB)

Gougeon, R

1994-09-26

In most previous studies of aerosol filtration, attention is focused on the maximum penetrating particle size region where the predominant mechanisms for collection are brownian diffusion and interception. In contrary the inertial regime remains poorly understood. Therefore, the aim of this study was to improve understanding of the behaviour of fibrous filters with liquid aerosols ar high frontal velocities both in the stationary and nonstationary filtration. Stationary filtration is first investigated. Experiments are done with special filters called `formettes` which have well defined structural characteristics. Precise results obtained with those filters allow us to select two relations quoted in the literature in order to describe the diffusion and the interception and to determine an empirical correlation describing the inertial impaction. Then this correlation with an industrial filter. In the second part, the evolution of the performances of fibrous filters loaded with liquid aerosols is studied experimentally and theoretically. We show that, in the inertial regime the filter efficiency first decreases and then increases rapidly with the loading rate. This increase is particularly important at high frontal velocities and with big particles. Macroscopic observations of high loaded filters show that the liquid is located in the fibre`s intersections to form big flat surfaces. A tentative of describing the evolution of the filter efficiency in modifying our stationary filtration model in order to take into account those liquid surfaces in the filter gives encouraging results. (authors). 92 refs., 93 figs., 11 tabs., 4 appends.

GENOMIQUE ET LIPIDES Génomique et métabolisme des lipides des plantes

Directory of Open Access Journals (Sweden)

Delseny Michel

2002-03-01

Full Text Available Il existe dans les bases de données publiques une énorme quantité de séquences d’ADN dérivées de plantes, et notamment la séquence complète du génome d’Arabidopsis thaliana, une plante modèle pour les oléagineux, proche parente du colza. Ces données constituent une ressource importante non seulement pour la compréhension de métabolisme lipidique et de sa régulation, mais aussi pour la sélection et le développement de variétés nouvelles d’oléagineux produisant davantage d’huiles ou des huiles de composition nouvelle. Cette abondance de séquences peut être exploitée, en utilisant les recherches d’homologies, pour identifier les gènes, pour obtenir des informations sur leur fonction, comme pour repérer des gènes candidats codant des fonctions nouvelles. L’analyse de ces bases de données a révélé que la majeure partie des gènes codant des enzymes impliquées dans le métabolisme lipidique appartient à des petites familles multigéniques, reflétant la diversification des fonctions des isoformes. Une analyse du catalogue des ADNc séquencés en aveugle reflète les niveaux d’expression des différents gènes et fournit un aperçu des régulations des flux au travers des voies métaboliques conduisant à la biosynthèse des lipides de réserve. La disponibilité de mutants et de lignées transgéniques d’Arabidopsis et le développement de puces à ADN qui permettent l’analyse simultanée de plusieurs milliers de gènes conduiront à une meilleure compréhension des facteurs qui régulent le métabolisme des huiles dans les graines. Une telle connaissance facilitera la manipulation de la composition des huiles et des quantités produites dans les graines.

Des dispositions responsables à prendre pour la protection des ...

African Journals Online (AJOL)

En considérant l'effet néfaste des maladies, des parasites, du changement climatique et d'autres facteurs environnementaux (les OGM par exemple) sur la survie des abeilles, la baisse de leurs populations dans certaines parties du monde ne saurait être attribuée aux seules pesticides. En plus, l'impact de ces derniers sur ...

Gestion des risques

CERN Document Server

Louisot, Jean-Paul

2009-01-01

Depuis le début du lie siècle, la gestion des risques connaît une véritable révolution culturelle. Jusqu'alors fonction technique, centrée autour de l'achat de couverture d'assurances, elle est devenue une discipline managériale et transversale : une valise d'instruments que chaque manager doit connaître et appliquer quels que soient son domaine de compétence et ses missions au sein de l'organisation. En effet, la gestion des risques est une culture qui doit être assimilée par chacun des acteurs. C'est précisément l'ambition des 101 questions rassemblées dans cet ouvrage : apporter à chaque manager d'entreprise, de collectivité, d'établissement de santé..., des réponses claires au " pourquoi " et au " comment " : Comment identifier les risques ? Comment analyser les risques ? Quels sont les objectifs de la gestion des risques ? Une carte des risques pour quoi faire ? Pourquoi faut-il financer les risques ? Les entreprises ont-elles des responsabilités pénales ? En quoi consiste la gestion...

Comportement des polluants des eaux pluviales urbaines en ...

African Journals Online (AJOL)

développement et la croissance des organismes vivant dans l'eau et particulièrement les micro- organismes. Le suivi des températures enregistrées oscille entre 9 et 16°C dans les trois sites d'observation durant la période ... de la lumière du soleil. Le site C est bien aéré et .... Effets de différents modes de gestion des eaux ...

Caractérisation des plantes médicinales à flavonoïdes des marchés ...

African Journals Online (AJOL)

Les espèces guinéo-congolaises sont les plus abondantes et le mode de dissémination majoritaire des diaspores est la zoochorie. Les plantes à flavonoïdes les plus utilisées sont : Combretum micranthum, Aloe vera, Ageratum conyzoïdes et Cylicodiscus gabonensis. Elles rentrent dans le traitement de 73 maladies parmi ...

Impact de la preparation des anodes crues et des conditions de cuisson sur la fissuration dans des anodes denses

Science.gov (United States)

Amrani, Salah

La fabrication de l'aluminium est realisee dans une cellule d'electrolyse, et cette operation utilise des anodes en carbone. L'evaluation de la qualite de ces anodes reste indispensable avant leur utilisation. La presence des fissures dans les anodes provoque une perturbation du procede l'electrolyse et une diminution de sa performance. Ce projet a ete entrepris pour determiner l'impact des differents parametres de procedes de fabrication des anodes sur la fissuration des anodes denses. Ces parametres incluent ceux de la fabrication des anodes crues, des proprietes des matieres premieres et de la cuisson. Une recherche bibliographique a ete effectuee sur tous les aspects de la fissuration des anodes en carbone pour compiler les travaux anterieurs. Une methodologie detaillee a ete mise au point pour faciliter le deroulement des travaux et atteindre les objectifs vises. La majorite de ce document est reservee pour la discussion des resultats obtenus au laboratoire de l'UQAC et au niveau industriel. Concernant les etudes realisees a l'UQAC, une partie des travaux experimentaux est reservee a la recherche des differents mecanismes de fissuration dans les anodes denses utilisees dans l'industrie d'aluminium. L'approche etait d'abord basee sur la caracterisation qualitative du mecanisme de la fissuration en surface et en profondeur. Puis, une caracterisation quantitative a ete realisee pour la determination de la distribution de la largeur de la fissure sur toute sa longueur, ainsi que le pourcentage de sa surface par rapport a la surface totale de l'echantillon. Cette etude a ete realisee par le biais de la technique d'analyse d'image utilisee pour caracteriser la fissuration d'un echantillon d'anode cuite. L'analyse surfacique et en profondeur de cet echantillon a permis de voir clairement la formation des fissures sur une grande partie de la surface analysee. L'autre partie des travaux est basee sur la caracterisation des defauts dans des echantillons d'anodes crues

Presentation the national Plan of management of radioactive materials and wastes. Friday, the 4. of June 2010

International Nuclear Information System (INIS)

2010-01-01

After a synthesis of the national plan of management of radioactive materials and wastes (PNGMDR for Plan national de gestion des matieres et des dechets radioactifs), this document contains the main conclusions of this plan for the period 2010-2012, a presentation of its elaboration modalities, a presentation of the basic principles regarding radioactive materials and wastes (definitions, origins, waste types and categories, waste management types), a presentation of the main actors of their management (agencies, ministries, authorities, research organizations, institutional bodies, associations). A glossary and other documents are provided, notably a presentation of the ASN (the French Nuclear Safety Authority), a report by the ANDRA agency giving an inventory of radioactive materials and wastes, and a chapter of a report on nuclear safety and radioprotection status in France in 2009

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

Energy Technology Data Exchange (ETDEWEB)

Turner, David, D.; Ferrare, Richard, A.

2011-07-06

The 'Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds' project focused extensively on the analysis and utilization of water vapor and aerosol profiles derived from the ARM Raman lidar at the Southern Great Plains ARM site. A wide range of different tasks were performed during this project, all of which improved quality of the data products derived from the lidar or advanced the understanding of atmospheric processes over the site. These activities included: upgrading the Raman lidar to improve its sensitivity; participating in field experiments to validate the lidar aerosol and water vapor retrievals; using the lidar aerosol profiles to evaluate the accuracy of the vertical distribution of aerosols in global aerosol model simulations; examining the correlation between relative humidity and aerosol extinction, and how these change, due to horizontal distance away from cumulus clouds; inferring boundary layer turbulence structure in convective boundary layers from the high-time-resolution lidar water vapor measurements; retrieving cumulus entrainment rates in boundary layer cumulus clouds; and participating in a field experiment that provided data to help validate both the entrainment rate retrievals and the turbulent profiles derived from lidar observations.

La cire cuticulaire des grains de raisin et des feuilles de la vigne

Directory of Open Access Journals (Sweden)

F. RADLER

1968-06-01

Full Text Available Je voudrais parler ici des recherches que j'ai effectuées dans le cadre d'un programme de recherches de l'Organisation australienne de recherches (C.S.I.R.O.. Ce sont des recherches sur la structure, la composition chimique et le rôle de la cire cuticulaire des grains de raisins et des feuilles. Ces recherches ont été effectuées principalement lors de l'étude des problèmes relatifs au séchage des raisins pour la production des raisins. Cependant, l'importance de la cire cuticulaire ne se limite pas seulement au séchage des raisins, car elle concerne aussi l'œnologie et les problèmes de la conservation des raisins de table. Je pense donc que mon exposé peut présenter pour vous un certain intérêt.

statut de la matiere organique des cambisols et des lixisols sous

African Journals Online (AJOL)

Administrateur

L'étude vise à évaluer la matière organique des Cambisols et des Lixisols sous formations naturelles de longue durée en zone climatique nord-soudanienne et à établir, les relations entre ... sont supérieures à celles des sols des zones sahélienne et sud-soudanienne. ... globale a eu une corrélation positive avec le pH.

Operating Experience with the BR-5 Reactor; Experience acquise aupres du reacteur BR-5; Opyt ehkspluatatsii reaktora BR-5; Experiencia practica con el reactor BR-5

Energy Technology Data Exchange (ETDEWEB)

Lejpunskij, A. I.; Kazachkovskij, O. D.; Pinkhasik, M. S.; Aristarkhov, N. N.; Karpov, A. V.; Larin, E. P.; Efimov, I. A.

1963-10-15

The paper discusses the carrying-out of repair and maintenance work on the radioactive liquid-metal circuit of the BR-5 fast neutron reactor. Attention is also given to problems of reactor operation after achievement of the planned 2% fuel burn-up with some disturbance of leak-tightness in individual fuel elements. An account is given of experience in discharging the active section, examining the condition and leak-tightness of the fuel elements, and decontaminating the equipment and piping of the first radioactive circuit after reaching 5% fuel burn-up. (author) [French] Dans ce memoire les auteurs decrivent l'execution des reparations et des travaux d'entretien dans le circuit radioactif liquide-metal du reacteur a neutrons rapides BR-5. Ils etudient egalement les problemes lies au fonctionnement du reacteur au taux de combustion de 2% prevu avec quelques defauts d'etancheite dans des elements combustibles particuliers. Ils decrivent le dechargementen zone active et examinent les conditions d'etancheite des elements combustibles. Ainsi que la decontamination de l'appareillage et des tuyauteries du premier circuit radioactif apres avoir atteint un taux de combustion de 5%. (author) [Spanish] En la memoria se examinan los problemas planteados por el mantenimiento del circuito radiactivo de metal liquido del reactor de neutrones rapidos BR-5. Se tratan cuestiones relacionadas con la explotacion del reactor una vez alcanzado el grado de combustion de 2%, previsto en el proyecto y luego de producirse ciertas alteraciones de la densidad de determinados elementos combustibles. Se describen la experiencia adquirida durante la descarga del cuerpo del reactor, las investigaciones del estado general y de la hermeticidad de los elementos combustibles y las operaciones de descontaminacion de la instalacion y de las tuberias del circuito radiactivo primario despues de alcanzado un grado de combustion de 5%. (author) [Russian] V doklade rassmatrivayutsya voprosy proizvodstva

Fiabilité des structures mécaniques adaptatives: effet de la panne des actionneurs ou des capteurs sur la stabilité

Science.gov (United States)

Fall, H.; Charon, W.; Kouta, R.

2002-12-01

Ces dernières décennies, des activités significatives dans le monde étaient dirigées autour du contrôle actif. Le but de ces recherches était essentiellement d'améliorer les performances, la fiabilité et la sécurité des systèmes. Notamment dans le cas des structures soumises à des vibrations aléatoires. D'importants travaux ont été consacré à l'utilisation des “matériaux intelligents” comme capteurs et actionneurs. Cette article propose l'analyse de la fiabilité des systèmes mécaniques en étudiant les pannes des actionneurs ou des capteurs. L'effet de ces pannes sur la stabilité et la performance du système y est démontré. Les méthodologies de conception y sont rappelées. Des exemples numériques sont fournis à travers le contrôle d'un panneau sous chargement dynamique pour illustrer la méthode proposée.

Aerosol retrieval experiments in the ESA Aerosol_cci project

Directory of Open Access Journals (Sweden)

T. Holzer-Popp

2013-08-01

Full Text Available Within the ESA Climate Change Initiative (CCI project Aerosol_cci (2010–2013, algorithms for the production of long-term total column aerosol optical depth (AOD datasets from European Earth Observation sensors are developed. Starting with eight existing pre-cursor algorithms three analysis steps are conducted to improve and qualify the algorithms: (1 a series of experiments applied to one month of global data to understand several major sensitivities to assumptions needed due to the ill-posed nature of the underlying inversion problem, (2 a round robin exercise of "best" versions of each of these algorithms (defined using the step 1 outcome applied to four months of global data to identify mature algorithms, and (3 a comprehensive validation exercise applied to one complete year of global data produced by the algorithms selected as mature based on the round robin exercise. The algorithms tested included four using AATSR, three using MERIS and one using PARASOL. This paper summarizes the first step. Three experiments were conducted to assess the potential impact of major assumptions in the various aerosol retrieval algorithms. In the first experiment a common set of four aerosol components was used to provide all algorithms with the same assumptions. The second experiment introduced an aerosol property climatology, derived from a combination of model and sun photometer observations, as a priori information in the retrievals on the occurrence of the common aerosol components. The third experiment assessed the impact of using a common nadir cloud mask for AATSR and MERIS algorithms in order to characterize the sensitivity to remaining cloud contamination in the retrievals against the baseline dataset versions. The impact of the algorithm changes was assessed for one month (September 2008 of data: qualitatively by inspection of monthly mean AOD maps and quantitatively by comparing daily gridded satellite data against daily averaged AERONET sun

Évaluation des émissions de gaz à effet de serre des filières de traitement et de valorisation des boues issues du traitement des eaux usées

OpenAIRE

Reverdy, A.L.; Pradel, M.

2011-01-01

/ Ce rapport présente l'inventaire des différentes consommations énergétiques, en consommables et des GES pour chaque poste de traitement et de valorisation des boues issues du traitement des eaux usées.

The Two-Column Aerosol Project: Phase I - Overview and Impact of Elevated Aerosol Layers on Aerosol Optical Depth

Science.gov (United States)

Berg, Larry K.; Fast, Jerome D.; Barnard, James C.; Burton, Sharon P.; Cairns, Brian; Chand, Duli; Comstock, Jennifer M.; Dunagan, Stephen; Ferrare, Richard A.; Flynn, Connor J.;

The Two-Column Aerosol Project: Phase I - Overview and Impact of Elevated Aerosol Layers on Aerosol Optical Depth

Energy Technology Data Exchange (ETDEWEB)

Berg, Larry K.; Fast, Jerome D.; Barnard, James C.; Burton, Sharon; Cairns, Brian; Chand, Duli; Comstock, Jennifer M.; Dunagan, Stephen; Ferrare, Richard A.; Flynn, Connor J.; Hair, John; Hostetler, Chris A.; Hubbe, John M.; Jefferson, Anne; Johnson, Roy; Kassianov, Evgueni I.; Kluzek, Celine D.; Kollias, Pavlos; Lamer, Katia; Lantz, K.; Mei, Fan; Miller, Mark A.; Michalsky, Joseph; Ortega, Ivan; Pekour, Mikhail S.; Rogers, Ray; Russell, P.; Redemann, Jens; Sedlacek, Art; Segal Rozenhaimer, Michal; Schmid, Beat; Shilling, John E.; Shinozuka, Yohei; Springston, Stephen R.; Tomlinson, Jason M.; Tyrrell, Megan; Wilson, Jacqueline; Volkamer, Rainer M.; Zelenyuk, Alla; Berkowitz, Carl M.

2016-01-08

The Two-Column Aerosol Project (TCAP), which was conducted from June 2012 through June 2013, was a unique field study that was designed to provide a comprehensive data set that can be used to investigate a number of important climate science questions, including those related to aerosol mixing state and aerosol radiative forcing. The study was designed to sample the atmosphere at a number of altitudes, from near the surface to as high as 8 km, within two atmospheric columns; one located near the coast of North America (over Cape Cod, MA) and a second over the Atlantic Ocean several hundred kilometers from the coast. TCAP included the yearlong deployment of the U.S. Department of Energy’s (DOE) Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) that was located at the base of the Cape Cod column, as well as summer and winter aircraft intensive observation periods of the ARM Aerial Facility. One important finding from TCAP is the relatively common occurrence (on four of six nearly cloud-free flights) of elevated aerosol layers in both the Cape Cod and maritime columns that were detected using the nadir pointing second-generation NASA high-spectral resolution lidar (HSRL-2). These layers contributed up to 60% of the total aerosol optical depth (AOD) observed in the column. Many of these layers were also intercepted by the aircraft configured for in situ sampling, and the aerosol in the layers was found to have increased amounts of biomass burning aerosol and nitrate compared to the aerosol found near the surface.

The Two-Column Aerosol Project: Phase I—Overview and impact of elevated aerosol layers on aerosol optical depth

Science.gov (United States)

Berg, Larry K.; Fast, Jerome D.; Barnard, James C.; Burton, Sharon P.; Cairns, Brian; Chand, Duli; Comstock, Jennifer M.; Dunagan, Stephen; Ferrare, Richard A.; Flynn, Connor J.; Hair, Johnathan W.; Hostetler, Chris A.; Hubbe, John; Jefferson, Anne; Johnson, Roy; Kassianov, Evgueni I.; Kluzek, Celine D.; Kollias, Pavlos; Lamer, Katia; Lantz, Kathleen; Mei, Fan; Miller, Mark A.; Michalsky, Joseph; Ortega, Ivan; Pekour, Mikhail; Rogers, Ray R.; Russell, Philip B.; Redemann, Jens; Sedlacek, Arthur J.; Segal-Rosenheimer, Michal; Schmid, Beat; Shilling, John E.; Shinozuka, Yohei; Springston, Stephen R.; Tomlinson, Jason M.; Tyrrell, Megan; Wilson, Jacqueline M.; Volkamer, Rainer; Zelenyuk, Alla; Berkowitz, Carl M.

2016-01-01

The Two-Column Aerosol Project (TCAP), conducted from June 2012 through June 2013, was a unique study designed to provide a comprehensive data set that can be used to investigate a number of important climate science questions, including those related to aerosol mixing state and aerosol radiative forcing. The study was designed to sample the atmosphere between and within two atmospheric columns; one fixed near the coast of North America (over Cape Cod, MA) and a second moveable column over the Atlantic Ocean several hundred kilometers from the coast. The U.S. Department of Energy's (DOE) Atmospheric Radiation Measurement (ARM) Mobile Facility (AMF) was deployed at the base of the Cape Cod column, and the ARM Aerial Facility was utilized for the summer and winter intensive observation periods. One important finding from TCAP is that four of six nearly cloud-free flight days had aerosol layers aloft in both the Cape Cod and maritime columns that were detected using the nadir pointing second-generation NASA high-spectral resolution lidar (HSRL-2). These layers contributed up to 60% of the total observed aerosol optical depth (AOD). Many of these layers were also intercepted by the aircraft configured for in situ sampling, and the aerosol in the layers was found to have increased amounts of biomass burning material and nitrate compared to aerosol found near the surface. In addition, while there was a great deal of spatial and day-to-day variability in the aerosol chemical composition and optical properties, no systematic differences between the two columns were observed.

Special aerosol sources for certification and test of aerosol radiometers

International Nuclear Information System (INIS)

Belkina, S.K.; Zalmanzon, Y.E.; Kuznetsov, Y.V.; Rizin, A.I.; Fertman, D.E.

1991-01-01

The results are presented of the development and practical application of new radionuclide source types (Special Aerosol Sources (SAS)), that meet the international standard recommendations, which are used for certification and test of aerosol radiometers (monitors) using model aerosols of plutonium-239, strontium-yttrium-90 or uranium of natural isotope composition and certified against Union of Soviet Socialist Republics USSR national radioactive aerosol standard or by means of a reference radiometer. The original technology for source production allows the particular features of sampling to be taken into account as well as geometry and conditions of radionuclides radiation registration in the sample for the given type of radiometer. (author)

Special aerosol sources for certification and test of aerosol radiometers

Energy Technology Data Exchange (ETDEWEB)

Belkina, S.K.; Zalmanzon, Y.E.; Kuznetsov, Y.V.; Rizin, A.I.; Fertman, D.E. (Union Research Institute of Instrumentation, Moscow (USSR))

1991-01-01

The results are presented of the development and practical application of new radionuclide source types (Special Aerosol Sources (SAS)), that meet the international standard recommendations, which are used for certification and test of aerosol radiometers (monitors) using model aerosols of plutonium-239, strontium-yttrium-90 or uranium of natural isotope composition and certified against Union of Soviet Socialist Republics USSR national radioactive aerosol standard or by means of a reference radiometer. The original technology for source production allows the particular features of sampling to be taken into account as well as geometry and conditions of radionuclides radiation registration in the sample for the given type of radiometer. (author).

Aerosols and the lungs

International Nuclear Information System (INIS)

1987-01-01

The lectures of the colloquium are discussed in summary form. There were 5 lectures on aerosol deposition, 5 on aerosol elimination, 7 on toxicology, and 7 on the uses of aerosols in medical therapy. In some cases aerosols with radioactive labels were used. Several lectures reviewed the kinetics and toxicology of airborne environmental pollutants. (MG) [de

Renforcement de l'autonomie des collectivités au moyen des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Cette subvention permettra au ministère des Communications et des Technologies de l'information de l'Égypte ainsi qu'au fonds spécial réservé aux TI de consolider le modèle actuel des clubs de TI en Égypte, par l'entremise de services d'assistance sur demande, d'activités de formation à l'intention du personnel des ...

L' approche des options stratégiques des acteurs dans i' etude des relations tu travail

OpenAIRE

López Pino, Carmen Marina

2011-01-01

Faire une analyse de la proposition analytique développée par le MIT (Masachussetts Institute of Tecnology) inspirée du concept des options stratégiques pour I' objet de cet article. En premier lieu, les sujets traités seront la problematique des relations du travail et les découvertes fondamentales des différentes recherches de I' equipe du MIT. Après, I' étude fait une courte présentatión sur I' approche des systémes de Dunlop dont I' èquipe cherche améliorer. Ensuite, sont présentés...

Aerosols and Climate

Indian Academy of Sciences (India)

Large warming by elevated aerosols · AERONET – Global network (NASA) · Slide 25 · Slide 26 · Slide 27 · Slide 28 · Slide 29 · Slide 30 · Slide 31 · Long-term trends - Trivandrum · Enhanced warming over Himalayan-Gangetic region · Aerosol Radiative Forcing Over India _ Regional Aerosol Warming Experiment ...

Impact of cloud-borne aerosol representation on aerosol direct and indirect effects

Directory of Open Access Journals (Sweden)

S. J. Ghan

2006-01-01

Full Text Available Aerosol particles attached to cloud droplets are much more likely to be removed from the atmosphere and are much less efficient at scattering sunlight than if unattached. Models used to estimate direct and indirect effects of aerosols employ a variety of representations of such cloud-borne particles. Here we use a global aerosol model with a relatively complete treatment of cloud-borne particles to estimate the sensitivity of simulated aerosol, cloud and radiation fields to various approximations to the representation of cloud-borne particles. We find that neglecting transport of cloud-borne particles introduces little error, but that diagnosing cloud-borne particles produces global mean biases of 20% and local errors of up to 40% for aerosol, droplet number, and direct and indirect radiative forcing. Aerosol number, aerosol optical depth and droplet number are significantly underestimated in regions and seasons where and when wet removal is primarily by stratiform rather than convective clouds (polar regions during winter, but direct and indirect effects are less biased because of the limited sunlight there and then. A treatment that predicts the total mass concentration of cloud-borne particles for each mode yields smaller errors and runs 20% faster than the complete treatment. The errors are much smaller than current estimates of uncertainty in direct and indirect effects of aerosols, which suggests that the treatment of cloud-borne aerosol is not a significant source of uncertainty in estimates of direct and indirect effects.

Regional and monthly and clear-sky aerosol direct radiative effect (and forcing derived from the GlobAEROSOL-AATSR satellite aerosol product

Directory of Open Access Journals (Sweden)

G. E. Thomas

2013-01-01

Full Text Available Using the GlobAEROSOL-AATSR dataset, estimates of the instantaneous, clear-sky, direct aerosol radiative effect and radiative forcing have been produced for the year 2006. Aerosol Robotic Network sun-photometer measurements have been used to characterise the random and systematic error in the GlobAEROSOL product for 22 regions covering the globe. Representative aerosol properties for each region were derived from the results of a wide range of literature sources and, along with the de-biased GlobAEROSOL AODs, were used to drive an offline version of the Met Office unified model radiation scheme. In addition to the mean AOD, best-estimate run of the radiation scheme, a range of additional calculations were done to propagate uncertainty estimates in the AOD, optical properties, surface albedo and errors due to the temporal and spatial averaging of the AOD fields. This analysis produced monthly, regional estimates of the clear-sky aerosol radiative effect and its uncertainty, which were combined to produce annual, global mean values of (−6.7 ± 3.9 W m⁻² at the top of atmosphere (TOA and (−12 ± 6 W m⁻² at the surface. These results were then used to give estimates of regional, clear-sky aerosol direct radiative forcing, using modelled pre-industrial AOD fields for the year 1750 calculated for the AEROCOM PRE experiment. However, as it was not possible to quantify the uncertainty in the pre-industrial aerosol loading, these figures can only be taken as indicative and their uncertainties as lower bounds on the likely errors. Although the uncertainty on aerosol radiative effect presented here is considerably larger than most previous estimates, the explicit inclusion of the major sources of error in the calculations suggest that they are closer to the true constraint on this figure from similar methodologies, and point to the need for more, improved estimates of both global aerosol loading and aerosol optical properties.

Developpement des betons semi autoplacants a rheologie adaptee pour des infrastructures

Science.gov (United States)

Sotomayor Cruz, Cristian Daniel

Au cours des dernières décennies, les infrastructures canadiennes et québécoises comportent plusieurs structures en béton armé présentant des problèmes de durabilité dus aux conditions climatiques sévères, à la mauvaise conception des structures, à la qualité des matériaux, aux types des bétons choisis, aux systèmes de construction ou à l'existence d'événements incontrôlables. En ce qui concerne le choix du béton pour la construction des infrastructures, une vaste gamme de béton divisée en deux principaux types peut être utilisée: le béton conventionnel vibré (BCV) et le béton autoplaçant (BAP). Dans le cas d'un BCV, la consolidation inadéquate par vibration a été un problème récurrent, occasionnant des dommages structuraux. Ceci a conduit à une réduction de la durabilité et à une augmentation du coût d'entretien et de réparation des infrastructures. Rien que l'utilisation d'un BAP a des avantages tels que l'élimination de la vibration, la réduction des coûts de main d'oeuvre et l'amélioration de la qualité des structures, néanmoins, le coût initial d'un BAP par rapport à un BCV ne permet pas encore de généraliser son utilisation dans l'industrie de la construction. Ce mémoire présente la conception d'une nouvelle gamme de béton semi-autoplaçant pour la construction des infrastructures (BSAP-I) exigeant une vibration minimale. Il s'agit de trouver un équilibre optimal entre la rhéologie et le coût initial du nouveau béton pour conférer une bonne performance structurale et économique aux structures. Le programme expérimental établi a premièrement permis d'évaluer la faisabilité d'utilisation des BSAP-I pour la mise en place des piliers d'une infrastructure de pont à Sherbrooke. En plus, l'utilisation d'un plan d'expériences a permis l'évaluation de trois paramètres de formulation sur les propriétés des mélanges de BSAP-I à l'état frais et durci. Finalement, l'évaluation de la performance des

Libération des acides gras par autolyse enzymatique des triglycérides des graines oléoprotéagineuses

Directory of Open Access Journals (Sweden)

Alibert Gilbert

2001-01-01

Full Text Available Les acides gras produits par hydrolyse chimique des lipides des plantes sont des matériaux de base pour l’industrie des biocarburants, des lubrifiants, des plastiques, des détergents et également des adjuvants de préparations commerciales d’herbicides. Cependant les procédés actuels de production des acides gras sont hautement polluants et coûteux en énergie. Dans ce travail nous développons un nouveau procédé de production des acides gras mettant en œuvre des plantes génétiquement modifiées. Nous avons introduit dans le tabac, retenu comme plante modèle, une construction génétique comprenant un gène de lipase (de la levure Geotrichum candidum sous le contrôle d’un promoteur graine spécifique (promoteur AtEm1 d’Arabidopsis thaliana. Ce promoteur devrait permettre l’expression du gène de lipase au niveau de l’axe embryonnaire tandis que les lipides s’accumulent dans les corps lipidiques des cotylédons. Dans ces conditions, les lipides de la graine devraient être séparés de la lipase par une compartimentation tissulaire et ne pas interférer. Après broyage des graines on peut penser que la mise en contact des lipides et de la lipase conduira à la libération d’acides gras. Plusieurs transformants ont été produits par transfert de gène à l’aide d’Agrobacterium tumefaciens, quelques-uns d’entre eux exprimant, comme attendu, la lipase dans leurs graines. Trois clones (2, 19 et 43 présentent une activité lipase significative et ont été retenus pour des études complémentaires. Cependant l’activité enzymatique observée est faible et certains clones présentent un défaut de compartimentation entre l’enzyme et les lipides se traduisant par la production d’acides gras dans la graine intacte. Lorsque les graines du clone 43 sont broyées dans un tampon, des acides gras sont produits dans le milieu réactionnel, validant le procédé imaginé. De nouvelles constructions réalisées, soit

Application of radioactivity to subterranean hydraulic engineering (1961); Application de la radioactivite a l'hydraulique souterraine (1961)

Energy Technology Data Exchange (ETDEWEB)

Hours, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1961-07-01

The search for radioactive tracers for water capable of percolating through permeable grounds without significant absorption has led to the choosing of two isotopes, bromine 82 (half-life 36 hours) and iodine (half-life 8 days), both {gamma} emitters; various combinations of other {gamma} emitters with longer half-lives have been tried but with only partial success. The recent progress in the dosage of tritium should make it possible to widen the field of application of this tracer which is unique in its kind. Being detectable at concentrations of 10{sup -6} to 10{sup -8} curies per cubic meter, the radioactive tracers are suitable for all the usual applications of conventional tracers; furthermore, some original techniques have been devised for measurements of flow, of reservoir capacity, of porosity and of permeability. Techniques based on the absorption and scattering of {gamma}-rays have also been developed for the measurement of the density, the humidity and the porosity of soils, and also for their analysis. Up to the present, radioactivity has been mainly applied to the study of oil-bearing formations. Furthermore, the study of the distribution of natural of thermonuclear tritium has contributed greatly to the study of the hydrological cycle. (author) [French] La recherche de traceurs radioactifs de l'eau susceptibles de circuler a travers les terrains permeables sans retention notable a abouti a la selection de deux isotopes, le brome 82 (periodes 36 heures) et l'iode (periode 8 jours), tous deux emetteurs {gamma}; diverses combinaisons mettant en jeu des emetteurs {gamma} de periode plus longue ont ete essayees, mais avec un succes partiel. Les progres recemment accomplis dans le dosage du tritium doivent permettre une rapide extension de l'emploi de ce traceur unique en son genre. Decelables a des concentrations de 10{sup -6} a 10{sup -8} curies par metre cube, les traceurs radioactifs se pretent a toutes les applications des traceurs classiques; de plus

TOMS Absorbing Aerosol Index

Data.gov (United States)

Washington University St Louis — TOMS_AI_G is an aerosol related dataset derived from the Total Ozone Monitoring Satellite (TOMS) Sensor. The TOMS aerosol index arises from absorbing aerosols such...

Paternité des articles et intérêts concurrents : une analyse des recommandations aux auteurs des journaux traitant de pratique pharmaceutique

Science.gov (United States)

Courbon, Ève; Tanguay, Cynthia; Lebel, Denis; Bussières, Jean-François

2014-01-01

RÉSUMÉ Contexte : La présence d’auteurs honorifiques et fantômes ainsi que les intérêts concurrents représentent des difficultés bien documentées, liées à la publication d’articles scientifiques. Il existe des lignes directrices encadrant la rédaction et la publication de manuscrits scientifiques, notamment celles de l’International Committee of Medical Journal Editors (ICMJE). Objectifs : L’objectif principal de cette étude descriptive et transversale visait à recenser les instructions portant sur la paternité des articles et les intérêts concurrents provenant des recommandations aux auteurs des journaux traitant de pratique pharmaceutique. L’objectif secondaire visait à déterminer des mesures correctrices pour une paternité des articles plus transparente. Méthode : La recherche a débuté par l’identification des journaux traitant de pratique pharmaceutique. La consultation des instructions aux auteurs des journaux a permis ensuite de recenser les recommandations destinées à éviter les problèmes de paternité des articles et d’intérêts concurrents. Finalement, les membres de l’équipe de recherche se sont consultés afin de définir des mesures correctrices possibles à l’intention des chercheurs. Résultats : Des 232 journaux traitant de pharmacie, 33 ont été définis comme traitant de pratique pharmaceutique. Un total de 24 (73 %) journaux mentionnaient suivre la politique de l’ICMJE, 14 (42 %) demandaient aux auteurs de remplir un formulaire de déclaration d’intérêts concurrents au moment de la soumission de l’article, 17 (52 %) présentaient une définition de la qualité d’auteur et 5 (15 %) demandaient de détailler les contributions de chaque auteur. Une grille de 40 critères a été élaborée pour définir l’attribution du statut d’auteur. Conclusion : Moins de la moitié des journaux demandait aux auteurs de transmettre un formulaire de déclaration des intérêts concurrents au moment de la

Atmospheric aerosol system: An overview

International Nuclear Information System (INIS)

Prospero, J.M.; Charlson, R.J.; Mohnen, V.; Jaenicke, R.; Delany, A.C.; Moyers, J.; Zoller, W.; Rahn, K.

1983-01-01

Aerosols could play a critical role in many processes which impact on our lives either indirectly (e.g., climate) or directly (e.g., health). However, our ability to assess these possible impacts is constrained by our limited knowledge of the physical and chemical properties of aerosols, both anthropogenic and natural. This deficiency is attributable in part to the fact that aerosols are the end product of a vast array of chemical and physical processes. Consequently, the properties of the aerosol can exhibit a great deal of variability in both time and space. Furthermore, most aerosol studies have focused on measurements of a single aerosol characteristic such as composition or size distribution. Such information is generally not useful for the assessment of impacts because the degree of impact may depend on the integral properties of the aerosol, for example, the aerosol composition as a function of particle size. In this overview we discuss recent work on atmospheric aerosols that illustrates the complex nature of the aerosol chemical and physical system, and we suggest strategies for future research. A major conclusion is that man has had a great impact on the global budgets of certain species, especially sulfur and nitrogen, that play a dominant role in the atmospheric aerosol system. These changes could conceivably affect climate. Large-scale impacts are implied because it has recently been demonstrated that natural and pollutant aerosol episodes can be propagated over great distances. However, at present there is no evidence linking anthropogenic activities with a persistent increase in aerosol concentrations on a global scale. A major problem in assessing man's impact on the atmospheric aerosol system and on global budgets is the absence of aerosol measurements in remote marine and continental areas

Contribution des radios communautaires a l'education des ...

African Journals Online (AJOL)

Contribution des radios communautaires a l'education des populations rurales pour un developpement durable au Benin: etude de cas. ... Journal de la Recherche Scientifique de l'Université de Lomé. Journal Home · ABOUT THIS JOURNAL ...

Rôle des germes parasites des bactéries pathogènes dans l'autoépuration des eaux

Directory of Open Access Journals (Sweden)

GUELIN A.

1969-04-01

Full Text Available Existence dans les eaux polluées de germes parasites qui s'attaquent aux bactéries pathogènes. Le pouvoir bactéricide des eaux polluées dû, en grande partie à la présence dans ces eaux de différents représentants des germes parasites. Possibilité d'application pratique des germes parasites pour l'assainissement des eaux polluées.

The reprocessing of irradiated fuels improvement and extension of the solvent extraction process; Le traitement des combustibles irradies amelioration et extension du procede utilisant les solvants

Energy Technology Data Exchange (ETDEWEB)

Faugeras, P; Chesne, A [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

. Le traitement au solvant est egalement utilise pour les combustibles de la pile convertisseuse du plutonium (Rapsodie). On expose et commente le schema du traitement, les premiers resultats experimentaux et le projet d'une installation pilote de 1 kg/jour. L'utilisation de la tn-laurylamine dans le cycle de purification du plutonium est envisagee dans l'usine de traitement de La Hague. On presente le schema adopte et les performances du procede. On envisage la vitrification comme traitement definitif des dechets radioactifs concentres des Centres de Marcoule (uranium-irradie) et La Hague (uranium-molybdene irradie). Trois procedes possibles sont decrits et commentes, ainsi que les resultats d'exploitation des installations correspondantes sur elements traceurs. (auteurs)

Facility of aerosol filtration

Energy Technology Data Exchange (ETDEWEB)

Duverger de Cuy, G; Regnier, J

1975-04-18

Said invention relates to a facility of aerosol filtration, particularly of sodium aerosols. Said facility is of special interest for fast reactors where sodium fires involve the possibility of high concentrations of sodium aerosols which soon clog up conventional filters. The facility intended for continuous operation, includes at the pre-filtering stage, means for increasing the size of the aerosol particles and separating clustered particles (cyclone separator).

Effets des extraits vegetaux sur la dynamique de populations des ...

African Journals Online (AJOL)

La présente étude se propose de trouver une alternative de l'utilisation des pesticides chimiques en testant l'effet insecticide des extraits aqueux des feuilles de Hyptis suaveolens, graines de Ricinus communis et de Azadirachta indica contre les ravageurs du niébé en conditions de champ en utilisant le cyperméthrine ...

Organ Visualization by Photoscanning Using Micro- and Macro-Aggregates of Radioalbumin; Examen d'Organes par Photoscintigraphie (avec des Micro-Agglomerats et des Macroagglomerats de Radioalbumine); Vizualizatsiya organov putem fotoskennirovaniya; Visualizacion de Organos por Fotoexploracion (Empleo de Micro y Macroagregados de Radioalbumina)

Energy Technology Data Exchange (ETDEWEB)

Taplin, G. V.; Johnson, D. E.; Dore, E. K.; Kaplan, H. S. [School of Medicine, University of California, Los Angeles (United States); Los Alamos County Harbor General Hospital, Torrance, CA (United States)

1964-10-15

Micro aggregates (10 - 20 nm) of human serum albumin I{sup 131} are shown to be superior to other agents for liver-spleen photoscanning. Radiation exposure to these organs is minimized and the test agent can be prepared with relative ease and simplicity. Also, the heart, stomach and salivary glands may be clearly visualized with the same material. The techniques and physiological basis for performing and interpreting scans of these organs are described. Their diagnostic value is illustrated. The physiological basis for using macro albumin aggregates (1 - 10 {mu}m) for visualization of the lungs is presented, along with typical scans in dogs. Toxicity studies and related pathophysiological investigations in animals demonstrate a wide margin of safety for using the large-particle test agents in man. Preliminary experiments in dogs indicate the feasibility of performing lung scans following the inhalation of an aerosol of the same material. This technique is simple, painless and entirely safe. Photoscans are presented from patients with a wide variety of pulmonary disorders. (author) [French] On a constate que les micro-agglomerats (10 a 20 nm) d'albumine de serum humain marquee avec {sup 131}I sont superieurs a toutes les autres substances pour la photoscintigraphie de la rate et du foie. Ils permettent de reduire au minimum la radioexposition de ces organes; en outre, leur preparation est relativement facile et simple. La m e m e substance permet d'explorer aussi bien le coeur, l'estomac et les glandes salivaires. Les auteurs exposent les methodes et les bases physiologiques d'execution et d'interpretation des scintigrammes de ces organes. Ils donnent des exemples de leur valeur pour le diagnostic. Les auteurs indiquent ensuite les arguments d'ordre physiologique qui militent en faveur de l'utilisation de macro-agglomerats (1 a 10 {mu}) de radioalbumine pour explorer les poumons et presentent des scintigrammes typiques faits sur des chiens. Les etudes de toxicite et

La participation des femmes à la vie politique se traduit par des ...

International Development Research Centre (IDRC) Digital Library (Canada)

La participation des femmes à la vie politique se traduit par des économies locales plus vigoureuses. 08 juin 2016. Image. Des femmes assistent à une réunion d'un groupe d'entraide près d'. Edgard Rodriguez - IDRC. Des femmes assistent à une réunion d'un groupe d'entraide près d'Hyderabad, en Inde. Keenara ...

Incidence des prix et des taxes sur la consommation de produits du ...

International Development Research Centre (IDRC) Digital Library (Canada)

Incidence des prix et des taxes sur la consommation de produits du tabac en Argentine, en Bolivie et au Chili. Partout en Amérique du Sud, les adultes et les enfants font une grande consommation de tabac. Un nouveau projet de recherche se penchera sur les avantages et les limites des stratégies de fixation des prix et de ...

Antarctic aerosols - A review

Science.gov (United States)

Shaw, Glenn E.

1988-02-01

Tropospheric aerosols with the diameter range of half a micron reside in the atmosphere for tens of days and teleconnect Antarctica with other regions by transport that reaches planetary scales of distances; thus, the aerosol on the Antarctic ice represents 'memory modules' of events that took place at regions separated from Antarctica by tens of thousands of kilometers. In terms of aerosol mass, the aerosol species include insoluble crustal products (less than 5 percent), transported sea-salt residues (highly variable but averaging about 10 percent), Ni-rich meteoric material, and anomalously enriched material with an unknown origin. Most (70-90 percent by mass) of the aerosol over the Antarctic ice shield, however, is the 'natural acid sulfate aerosol', apparently deriving from biological processes taking place in the surrounding oceans.

Characterization of urban aerosol using aerosol mass spectrometry and proton nuclear magnetic resonance spectroscopy

Science.gov (United States)

Cleveland, M. J.; Ziemba, L. D.; Griffin, R. J.; Dibb, J. E.; Anderson, C. H.; Lefer, B.; Rappenglück, B.

2012-07-01

Particulate matter was measured during August and September of 2006 in Houston as part of the Texas Air Quality Study II Radical and Aerosol Measurement Project. Aerosol size and composition were determined using an Aerodyne quadrupole aerosol mass spectrometer. Aerosol was dominated by sulfate (4.1 ± 2.6 μg m-3) and organic material (5.5 ± 4.0 μg m-3), with contributions of organic material from both primary (˜32%) and secondary (˜68%) sources. Secondary organic aerosol appears to be formed locally. In addition, 29 aerosol filter samples were analyzed using proton nuclear magnetic resonance (1H NMR) spectroscopy to determine relative concentrations of organic functional groups. Houston aerosols are less oxidized than those observed elsewhere, with smaller relative contributions of carbon-oxygen double bonds. These particles do not fit 1H NMR source apportionment fingerprints for identification of secondary, marine, and biomass burning organic aerosol, suggesting that a new fingerprint for highly urbanized and industrially influenced locations be established.

Roles et taches des accompagnateurs des patients hospitalises ...

African Journals Online (AJOL)

Roles et taches des accompagnateurs des patients hospitalises dans le service de pneumo-phtysiologie au Centre Hospitalier Universitaire Yalgado Ouedraogo de ... Logistical support represented by material support, drug supply, cleaning of premises, and littering occupied respectively 100%, 91%, 42% and 73%.

Indomethacin inhibits the increased airway responsiveness to histamine following inhalation of C5a des Arg in rabbits.

Science.gov (United States)

Berend, N; Armour, C L; Black, J L

1986-08-01

It has been shown that inhalation of C5a des Arg increases rabbit airway responsiveness to histamine and that this is associated with an influx of neutrophils into the airway walls. This study was undertaken to see if the augmented response to histamine can be blocked by the cyclo-oxygenase inhibitor indomethacin. Spontaneously breathing, anesthetised rabbits were studied in a volume displacement plethysmograph and pulmonary resistance (R1) was measured using the electrical subtraction technique. Histamine does response curves (HDR) were generated by measuring R1 after serial nubulisation of saline and histamine (1, 3, 10, 30 and 100 mg/ml). Aerosols of either saline or C5a des Arg (1.5 ug/ml) were then inhaled by the animals over a time period of 2 min. An HDR was then repeated 4 hours later. In 9 rabbits the inhalation of C5a des Arg resulted in an upward shift of the repeat HDR: the area under the HDR was significantly greater than under the first HDR (p less than 0.05). In 6 rabbits the repeat HDR 4 hours after saline was shifted downwards (N.S.) indicating some degree of tachyphylaxis. When rabbits were pretreated with indomethacin (5 mg/kg i.v.) the repeat HDR following either C5a des Arg (n = 7) or saline (n = 6) were also shifted downwards i.e., the increased airway responsiveness noted after C5a des Arg was abolished. There was no significant difference in baseline saline R1 during the first or second HDR in any group. These results suggest that the increased airway responsiveness following nebulisation of C5a des Arg may be due to release from neutrophils of products of the cyclo-oxygenase pathway.

Utilisation des mousses et des pâtes syntactiques pour combler les lacunes des poteries archéologiques

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Viviane Bechoux

2008-10-01

Full Text Available Filling potteries missing parts with plaster raises now complex problems during the de-restoration treatments. Ceramics restorers have recurrently questions on the use of plaster in the field of archaeological ceramics restoration. Some researches point to the choice of other filling materials. At the present time other methods can be devised by proposing plaster replacement by a lightened composite material: syntactic foams and pastes.Le comblement des lacunes des poteries à partir du plâtre pose actuellement des problèmes complexes lors des traitements de dérestauration. Les restaurateurs de céramiques s'interrogent de manière récurrente sur l'utilisation du plâtre dans le domaine de la restauration des céramiques archéologiques. Des recherches s'orientent vers le choix d'autres matériaux d'obturation. Actuellement, d'autres méthodes peuvent être mises en place en proposant le remplacement du plâtre par un matériau composite allégé, les mousses et les pâtes syntactiques.

Développer le leadership dans des villes de l'Amérique latine et des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Développer le leadership dans des villes de l'Amérique latine et des Caraïbes dans le contexte des changements climatiques. En raison des changements climatiques, de la croissance démographique et de l'urbanisation rapide non planifiée, les villes des pays en développement sont à la fois le principal déclencheur des ...

La Question de L'impunité des Auteurs de Violations des Droits de L'homme

Directory of Open Access Journals (Sweden)

Maria dos Remédios Fontes Silva

2010-10-01

Full Text Available Ce travail pretend faire reflechir à propos de la question de l'impunite des autorites de L'Etat face aux violations des droits de l'homme. On abordera cet egard: a le role de I'amnistie ble complicite des autoritesadministratives c la lenteur des procedures judicieuse.     L'analyse de cette question montre qui L'impunite des responsables des violations des droits de l'homme fait peser une menace sur I'ensemble du systeme de protection universelle des droits de l'homme.          On peut on conduire qu 'aucune societe que aspire à la democratie et ala justice ne peut se construire sur I'amoralite des crimes impunis et I'amnesie officielle.

Membrane fluidization by alcohols inhibits DesK-DesR signalling in Bacillus subtilis.

Science.gov (United States)

Vaňousová, Kateřina; Beranová, Jana; Fišer, Radovan; Jemioła-Rzemińska, Malgorzata; Matyska Lišková, Petra; Cybulski, Larisa; Strzałka, Kazimierz; Konopásek, Ivo

2018-03-01

After cold shock, the Bacillus subtilis desaturase Des introduces double bonds into the fatty acids of existing membrane phospholipids. The synthesis of Des is regulated exclusively by the two-component system DesK/DesR; DesK serves as a sensor of the state of the membrane and triggers Des synthesis after a decrease in membrane fluidity. The aim of our work is to investigate the biophysical changes in the membrane that are able to affect the DesK signalling state. Using linear alcohols (ethanol, propanol, butanol, hexanol, octanol) and benzyl alcohol, we were able to suppress Des synthesis after a temperature downshift. The changes in the biophysical properties of the membrane caused by alcohol addition were followed using membrane fluorescent probes and differential scanning calorimetry. We found that the membrane fluidization induced by alcohols was reflected in an increased hydration at the lipid-water interface. This is associated with a decrease in DesK activity. The addition of alcohol mimics a temperature increase, which can be measured isothermically by fluorescence anisotropy. The effect of alcohols on the membrane periphery is in line with the concept of the mechanism by which two hydrophilic motifs located at opposite ends of the transmembrane region of DesK, which work as a molecular caliper, sense temperature-dependent variations in membrane properties. Copyright © 2017 Elsevier B.V. All rights reserved.

Photonique des Morphos

CERN Document Server

Berthier, Serge

2010-01-01

La photonique est déjà présente dans notre vie quotidienne, et on attend maintenant que la manipulation des photons permette aussi le traitement logique des informations. Cependant, l’élément de base qui permet cette manipulation de la lumière, le cristal photonique, est d’une réalisation complexe et mal contrôlée. Dans la course à la maîtrise de la lumière, les structures photoniques naturelles ont beaucoup à nous apprendre. C’est ce que nous montre Serge Berthier qui étudie dans ce livre la structure des écailles des Morphos. Tenant compte de l’essor récent des approches biomimétiques, il présente de manière détaillée plus de dix-huit techniques expérimentales utilisées pour ses analyses, ainsi que les diverses approches théoriques développées pour la modélisation de structures multi-échelles complexes. Première étude quasi-exhaustive des structures fines d’un genre et des propriétés optiques ainsi que colorimétriques générées, ce livre fournit aux entomologiste...

Screening phytochimique et identification spectroscopique des ...

African Journals Online (AJOL)

Origin

plante, effectuée pour la première fois, a révélé la présence des alcaloïdes, des flavonoïdes, des tanins catéchiques, des terpènes, des coumarines et des composés cyanogénétiques. Quant aux saponines et les quinones libres, ils sont présents chez les fleurs et absents chez les feuilles. La caractérisation des molécules.

Disposal of Low-Activity Liquid Effluents by Dilution; Elimination par Dilution d'Effluents Liquides Faiblement Radioactifs; 0423 0414 0410 041b 0414 ; Eliminacion de Efluentes Liquidos de Baja Radiactividad por Dilucion

Energy Technology Data Exchange (ETDEWEB)

Bovard, P.; Candillon, C. [Service de Controle des Radiations et de Genie Radioactif, Commissariat a l' Energie Atomique, Saclay (France)

1960-07-01

obtenus Nous avons commence en 1957 une etude evolutive de l'incidence des installations nucleaires. Cette etude embrasse la determination des niveaux - de radioactivite naturelle - de contamination artificielle afin d'en degager la part revenant aux Centres Nucleaires. Des exemples sont cites faisant appel a des zones de reference. La plus grande partie de la radioactivite artificielle semble due aux retombees radioactives; ceci n'est pas surprenant si on examine les quantites d'isotopes radioactifs rejetees jusqu'a present en France. Un certain nombre d'essais de laboratoire ont ete effectues. Ils ont contribue a preciser certains mecanismes, ont accru notre connaissance de la pollution des sites et nous ont permis d'ameliorer nos methodes de prelevement. II. Essais de laboratoire Ils ont porte: 1. sur des 'phenomenes d'adsorption analogues a ceux produits dans les rivieres au cours de la dilution des effluents: fixation sur mineraux tres divises: mica, quartz. Des radioisotopes tels que {sup 90}Sr, {sup 137}Cs, {sup 90}Y semblent se comporter fort differemment: dans les conditions moyennes de rejet, le {sup 90}Sr serait le moins adsorbe. : 2. sur la contamination du sol et des vegetaux par l'emploi de colonnes et de cubes de sol en place. Ceci nous a conduit a standardiser nos prelevements, afin de faciliter les analyses ulterieures et de comparer utilement les resultats. III. Choix du site et modalites des rejets De ce faisceau de resultats et d'etudes encore incomplets, nous essayons de degager quelques principes quant au choix des sites. Le site une fois defini, l'experience acquise permet de tirer le meilleur parti des possibilites naturelles. (author) [Spanish] Con los resultados obtenidos en Francia vigilando la radiactividad en las proximidades de las instalaciones nucleares se pueden extraer determinadas conclusiones acerca de la eleccion de los procedimientos de evacuacion. I. Resultados obtenidos Los autores iniciaron en 1957 un estudio evolutivo de las

The prospection of uranium and thorium ores in desert country and in equatorial forest regions of the Union Francaise; La prospection des minerais d'uranium et de thorium dans les pays desertiques et dans les regions de foret equatoriale de l'Union Francaise

Energy Technology Data Exchange (ETDEWEB)

Lecoq, J J; Bigotte, G; Hinault, J; Leconte, J R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Since it was founded, the D.R.E.M. has carried out important prospection work in the overseas territories which now make up the Communaute Francaise. This work, now involving almost a million km{sup 2}, represents an experiment scarcely equalled throughout the world. Research in these territories presents both general and technical difficulties, which are especially severe in countries with extreme climates: deserts or dense equatorial forests. The adaptation of various methods of radioactive ore prospection to these regions is described, and also the results obtained. Three particular examples are given in detail: - general exploration in the Hoggar, and reconnoitring of particular indications; - general exploration in the equatorial forest of French Guyana; - detailed study of a sign of uraniferous occurrences and its surroundings in the equatorial zone (Mounana deposit near Franceville (Gabon)). (author) [French] Depuis sa creation, la D.R.E.M. poursuit un effort important de prospection dans les territoires d'outre-mer qui constituent maintenant la Communaute Fran ise. Ces travaux qui interessent maintenant pres d'un million de km{sup 2} constituent une experience qui a peu d'equivalent dans le monde. Les recherches dans ces territoires presentent des difficultes, sur le plan general et sur le plan technique, particulierement ardues dans les pays a climats excessifs: deserts ou forets equatoriales denses. On decrit l'adaptation des diverses methodes de prospection des minerais radioactifs a ces regions et les resultats qu'elles ont fournis. Trois exemples particuliers sont donnes en detail: - Exploration generale au Hoggar, et reconnaissance d'indices particuliers. - Exploration generale en foret equatoriale en Guyane fran ise. - Etude detaillee d'un indice uranifere et de ses environs en zone equatoriale (gisement de Mounana pres de France-ville (Gabon)). (auteur)

Aerosol Indices Derived from MODIS Data for Indicating Aerosol-Induced Air Pollution

Directory of Open Access Journals (Sweden)

Junliang He

2014-02-01

Full Text Available Aerosol optical depth (AOD is a critical variable in estimating aerosol concentration in the atmosphere, evaluating severity of atmospheric pollution, and studying their impact on climate. With the assistance of the 6S radiative transfer model, we simulated apparent reflectancein relation to AOD in each Moderate Resolution Imaging Spectroradiometer (MODIS waveband in this study. The closeness of the relationship was used to identify the most and least sensitive MODIS wavebands. These two bands were then used to construct three aerosol indices (difference, ratio, and normalized difference for estimating AOD quickly and effectively. The three indices were correlated, respectively, with in situ measured AOD at the Aerosol Robotic NETwork (AERONET Lake Taihu, Beijing, and Xianghe stations. It is found that apparent reflectance of the blue waveband (band 3 is the most sensitive to AOD while the mid-infrared wavelength (band 7 is the least sensitive. The difference aerosol index is the most accurate in indicating aerosol-induced atmospheric pollution with a correlation coefficient of 0.585, 0.860, 0.685, and 0.333 at the Lake Taihu station, 0.721, 0.839, 0.795, and 0.629 at the Beijing station, and 0.778, 0.782, 0.837, and 0.643 at the Xianghe station in spring, summer, autumn and winter, respectively. It is concluded that the newly proposed difference aerosol index can be used effectively to study the level of aerosol-induced air pollution from MODIS satellite imagery with relative ease.

Etude du processus de changement vecu par des familles ayant decide d'adopter volontairement des comportements d'attenuation des changements climatiques

Science.gov (United States)

Leger, Michel T.

Les activites humaines energivores telles l'utilisation intensive de l'automobile, la surconsommation de biens et l'usage excessif d'electricite contribuent aux changements climatiques et autres problemes environnementaux. Bien que plusieurs recherches rapportent que l'etre humain est de plus en plus conscient de ses impacts sur le climat de la planete, ces memes recherches indiquent qu'en general, les gens continuent a se comporter de facon non ecologique. Que ce soit a l'ecole ou dans la communaute, plusieurs chercheurs en education relative a l'environnement estiment qu'une personne bien intentionnee est capable d'adopter des comportements plus respectueux de l'environnement. Le but de cette these etait de comprendre le processus d'integration de comportements d'attenuation des changements climatiques dans des familles. A cette fin, nous nous sommes fixe deux objectifs : 1) decrire les competences et les procedes qui favorisent l'adoption de comportements d'attenuation des changements climatiques dans des familles et 2) decrire les facteurs et les dynamiques familiales qui facilitent et limitent l'adoption de comportements d'attenuation des changements climatiques dans des familles. Des familles ont ete invitees a essayer des comportements personnels et collectifs d'attenuation des changements climatiques de sorte a integrer des modes de vie plus ecologiques. Sur une periode de huit mois, nous avons suivi leur experience de changement afin de mieux comprendre comment se produit le processus de changement dans des familles qui decident volontairement d'adopter des comportements d'attenuation des changements climatiques. Apres leur avoir fourni quelques connaissances de base sur les changements climatiques, nous avons observe le vecu de changement des familles durant huit mois d'essais a l'aide de journaux reflexifs, d'entretiens d'explicitation et du journal du chercheur. La these comporte trois articles scientifiques. Dans le premier article, nous presentons une

Observational evidence for the aerosol impact on ice cloud properties regulated by cloud/aerosol types

Science.gov (United States)

Zhao, B.; Gu, Y.; Liou, K. N.; Jiang, J. H.; Li, Q.; Liu, X.; Huang, L.; Wang, Y.; Su, H.

2017-12-01

The interactions between aerosols and ice clouds (consisting only of ice) represent one of the largest uncertainties in global radiative forcing from pre-industrial time to the present. The observational evidence for the aerosol impact on ice cloud properties has been quite limited and showed conflicting results, partly because previous observational studies did not consider the distinct features of different ice cloud and aerosol types. Using 9-year satellite observations, we find that, for ice clouds generated from deep convection, cloud thickness, cloud optical thickness (COT), and ice cloud fraction increase and decrease with small-to-moderate and high aerosol loadings, respectively. For in-situ formed ice clouds, however, the preceding cloud properties increase monotonically and more sharply with aerosol loadings. The case is more complicated for ice crystal effective radius (Rei). For both convection-generated and in-situ ice clouds, the responses of Rei to aerosol loadings are modulated by water vapor amount in conjunction with several other meteorological parameters, but the sensitivities of Rei to aerosols under the same water vapor amount differ remarkably between the two ice cloud types. As a result, overall Rei slightly increases with aerosol loading for convection-generated ice clouds, but decreases for in-situ ice clouds. When aerosols are decomposed into different types, an increase in the loading of smoke aerosols generally leads to a decrease in COT of convection-generated ice clouds, while the reverse is true for dust and anthropogenic pollution. In contrast, an increase in the loading of any aerosol type can significantly enhance COT of in-situ ice clouds. The modulation of the aerosol impacts by cloud/aerosol types is demonstrated and reproduced by simulations using the Weather Research and Forecasting (WRF) model. Adequate and accurate representations of the impact of different cloud/aerosol types in climate models are crucial for reducing the

How important is organic aerosol hygroscopicity to aerosol indirect forcing?

International Nuclear Information System (INIS)

Liu Xiaohong; Wang Jian

2010-01-01

Organics are among the most abundant aerosol components in the atmosphere. However, there are still large uncertainties with emissions of primary organic aerosol (POA) and volatile organic compounds (VOCs) (precursor gases of secondary organic aerosol, SOA), formation of SOA, and chemical and physical properties (e.g., hygroscopicity) of POA and SOA. All these may have significant impacts on aerosol direct and indirect forcing estimated from global models. In this study a modal aerosol module (MAM) in the NCAR community atmospheric model (CAM) is used to examine sensitivities of aerosol indirect forcing to hygroscopicity (represented by a single parameter 'κ' ) of POA and SOA. Our model simulation indicates that in the present-day (PD) condition changing the 'κ' value of POA from 0 to 0.1 increases the number concentration of cloud condensational nuclei (CCN) at supersaturation S = 0.1% by 40-80% over the POA source regions, while changing the 'κ' value of SOA by ± 50% (from 0.14 to 0.07 and 0.21) changes the CCN concentration within 40%. There are disproportionally larger changes in CCN concentration in the pre-industrial (PI) condition. Due to the stronger impact of organics hygroscopicity on CCN and cloud droplet number concentration at PI condition, global annual mean anthropogenic aerosol indirect forcing (AIF) between PD and PI conditions reduces with the increase of the hygroscopicity of organics. Global annual mean AIF varies by 0.4 W m -2 in the sensitivity runs with the control run of - 1.3 W m -2 , highlighting the need for improved understanding of organics hygroscopicity and its representation in global models.

{beta} {gamma} porch detector; Detecteur portique {beta} {gamma}

Energy Technology Data Exchange (ETDEWEB)

Roulet, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

1963-07-01

This device is to be placed at the outside of reactors, hot laboratories and others where radioactive products are treated; it is intended to give the alarm when someone, passing through the porch is greatly contaminated, or carries, without his knowing, a radioactive substance. Being to be used in places where there might be an important ground noise, this device is provided with an automatic offset of this noise; an adjusting system of sensitivity allows to obtain a 15 {mu}Ci in {gamma} and 10 {mu}Ci in {beta} radioactive source, passing through the porch at the normal speed at which man is walking. A battery, set in buffer, allows working of the device, even when current is off. (author) [French] Cet appareil est destine a etre place a la sortie des reacteurs, laboratoires chauds ou autres laboratoires travaillant sur des produits radioactifs; son but est de donner une alarme lorsque quelqu'un, passant sous le portique, presente une forte contamination, ou surtout transporte par inadvertance un corps radioactif. Cet appareil devant etre utilise dans les lieux ou peut regner un bruit de fond important, possede une compensation automatique de ce bruit de fond; un reglage de la sensibilite permet d'obtenir au mieux un declenchement pour une source. de 15 {mu}Ci en {gamma} et 10 {mu}Ci en {beta} passant sous le portique a la vitesse normale d'un homme qui marche. Une batterie montee en tampon permet a l'appareil de fonctionner meme en cas de coupure de courant. (auteur)

L'accumulation des métaux lourds au niveau des cultures : Cas des ...

African Journals Online (AJOL)

Le Bassin de Sebou présente une importance socio-économique pour le Maroc. En effet, il est sujet de diverses utilisations ; eau potable, eau d'irrigation et eau industrielle. Toutefois, ce bassin subit des pressions multiples, notamment par la pollution métallique. Considérant le risque de bioaccumulation des métaux par ...

Radioactive Waste Facilities at the Australian Atomic Energy Commission Research Establishment; Installations pour le Traitement des Dechets Radioactifs au Centre de Recherche de la Commission Australienne a l'Energie Atomique; 0423 0421 0422 0414 ; Dispositivos para Evacuacion de Desechos Radiactivos en el Centro de Investigaciones de la Australian Atomic Energy Commission

Energy Technology Data Exchange (ETDEWEB)

Berglin, C. L.W.; Keher, L. H.; Miles, G. L.; Wilson, A. R.W. [Australian Atomic Energy Commission Research Establishment, Lucas Heights, Sydney, NSW (Australia)

1960-07-01

This paper describes the facilities,which are being provided for the collection, treatment and disposal of radioactive wastes at Lucas Heights in relation to the estimated arisings. Low-activity effluent is divided into three types: (a) Sewage; (b) Trades waste, arising from reactor cooling tower blow-down and engineering workshops and other inactive areas; and (c) Effluent arising from laboratories and other active areas. The effluent treatment plant for the latter type of effluent consists essentially of mixing and alkali dosing tanks, a sludge-blanket clarifier (using a calcium- iron-phosphate process) and holding tanks. Methods of concentrating the sludge and of secondary treatment are at present being investigated and are discussed. The discharge formula and the expected dilution obtained in the Woronora river are discussed, together with a dilution experiment carried out in the tidal waters. It is proposed to bury all low-activity solid waste after baling where appropriate and the choice and location of the disposal area is discussed. A facility for the storage and disposal of highly active solid waste is discussed. It is proposed to evaporate and store the medium- and high-activity liquid waste. Details are given of the capital and operating costs of the Effluent Treatment Plant and other waste handling facilities. (author) [French] Le memoire decrit les installations que le Centre de Lucas Heights cree a l'heure actuelle, eu egard au developpement envisage'en matiere de rassemblement, de traitement et d'elimination des dechets radioactifs. Les' effluents de faible activite se divisent en trois categories: a) Eaux d'egout; b) Dechets industriels provenant de la tour de refroidissement du reacteur, des ateliers et d'autres zones non-actives; c) Effluents provenant des laboratoires et d'autres zones actives. L'usine affectee au traitement du dernier type d'effluents se compose essentiellement de malaxeurs, de bacs de dosage d'alcalis, d'un clarificateur d

Contrôle des Circuits Auxiliaires des PFW (arrêt machines 2002/2003)

CERN Document Server

Ottaviani, J

2003-01-01

Les PFW sont des nappes polaires installées sur les pôles des aimants du PS. Elles sont au nombre de 4 par unité d aimant et constituées d un circuit principal (dans lequel circule le courant désiré selon le cycle magnétique utilisé) et de circuits auxiliaires. Les circuits auxiliaires sont des enroulements de correction (boucles de tour et pick-up brasés sur les enroulements). Pendant la variation du champ magnétique de l aimant PS, on utilise des tensions induites dans ces circuits auxiliaires pour corriger les erreurs de champ dues aux courants de Foucault dans la chambre à vide. Chaque année, pendant l arrêt machine, on vérifie si les caractéristiques des circuits auxiliaires correspondent aux normes (mesures des résistances des boucles de tours, résistances entre pick-up et isolation des circuits) afin de faire un suivi. Les 404 PFW sont ainsi vérifiées. Dans cette note, on ne relèvera que les PFW ayant des défauts (valeurs hors tolérances, boucles ouvertes ou en court-circuit, déf...

Containment aerosol behaviour simulation studies in the BARC nuclear aerosol test facility

International Nuclear Information System (INIS)

Mayya, Y.S.; Sapra, B.K.; Khan, Arshad; Sunny, Faby; Nair, R.N.; Raghunath, Radha; Tripathi, R.M.; Markandeya, S.G.; Puranik, V.D.; Ghosh, A.K.; Kushwaha, H.S.; Shreekumar, K.P.; Padmanabhan, P.V.A.; Murthy, P.S.S.; Venlataramani, N.

2005-02-01

A Nuclear Aerosol Test Facility (NATF) has been built and commissioned at Bhabha Atomic Research Centre to carry out simulation studies on the behaviour of aerosols released into the reactor containment under accident conditions. This report also discusses some new experimental techniques for estimation of density of metallic aggregates. The experimental studies have shown that the dynamic densities of aerosol aggregates are far lower than their material densities as expected by the well-known fractal theory of aggregates. In the context of codes, this has significant bearing in providing a mechanistic basis for the input density parameter used in estimating the aerosol evolution characteristics. The data generated under the quiescent and turbulent conditions and the information on aggregate densities are now being subjected to the validation of the aerosol behaviour codes. (author)

Comparative study of the ionic exchange of Ca{sup ++}, Sr{sup ++}, and Ba{sup ++} cations on resins and inorganic exchangers; Etude comparative de l'echange ionique des cations Ca{sup ++}, Sr{sup ++} et Ba{sup ++} sur resine et sur echangeurs mineraux

Energy Technology Data Exchange (ETDEWEB)

Sanchez Batanero, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-03-01

With a view to applying the results to certain problems related to chemical separations in activation analysis, a study has been made, of the possibilities of separating the alkaline-earth elements Ca, Sr and Ba on organic resins and inorganic exchangers using the radioactive indicator method. The partition coefficients of the cations Ca{sup 2+}, Sr{sup 2+} and Ba{sup 2+} have been measured on Dowex 50 W (NH{sub 4}{sup +}) x 8 resin in the presence of EDTA - NTA - EGTA and DCTA as complexing agents, and on zirconium phosphate, tungstate and molybdate in the presence of HCl and NH{sub 4}Cl. Methods have been developed for separating mixtures of alkaline-earth elements using DCTA-NH{sub 4}{sup +} followed by elution on Dowex 50 W (NH{sub 4}{sup +}) x 8 resin columns and on zirconium phosphate. Amongst the complexing agents used on the ion-exchange resins the most promising appears to be DCTA which leads to partition coefficients Ca, Sr and Ba which are very different. The results of measurements of partition coefficients on zirconium phosphate (NH{sub 4}{sup +} form) using DCTA-NH{sub 4}{sup +} show the interesting possibilities of separations on columns. The separation of the alkaline-earth elements on zirconium phosphate seems to be less quantitative than on Dowex 50 resin; it is however much faster in the former case and this can be useful for treating short half-life radioisotopes in activation analysis. (author) [French] En vue de l'application a certains problemes de separations chimiques en analyse par activation, on a etudie les possibilites de separation des elements alcalino-terreux Ca-Sr et Ba sur resine organique et sur echangeurs mineraux par la methode des indicateurs radioactifs. Les coefficients de partage des cations Ca{sup +2}, Sr{sup +2} et Ba{sup +2} sur resine Dowex 50 W (NH{sub 4}{sup +}) x 8 en milieux complexants EDTA - NTA - EGTA et DCTA et sur phosphate, tungstate et molybdate de zirconium en milieu HCl et NH{sub 4}Cl ont ete mesures. Des

Development of an aerosol decontamination factor evaluation method using an aerosol spectrometer

International Nuclear Information System (INIS)

Kanai, Taizo; Furuya, Masahiro; Arai, Takahiro; Nishi, Yoshihisa

2016-01-01

Highlights: • Aerosol DF of each diameter is evaluable by using optical scattering method. • Outlet aerosol concentration shows exponential decay by the submergence. • This decay constant depends on the aerosol diameter. • Aerosol DF at water scrubber is described by simple equation. - Abstract: During a severe nuclear power plant accident, the release of fission products into containment and an increase in containment pressure are assumed to be possible. When the containment is damaged by excess pressure or temperature, radioactive materials are released. Pressure suppression pools, containment spray systems and a filtered containment venting system (FCVS) reduce containment pressure and reduce the radioactive release into the environment. These devices remove radioactive materials via various mechanisms. Pressure suppression pools remove radioactive materials by pool scrubbing. Spray systems remove radioactive materials by droplet−aerosol interaction. FCVS, which is installed in the exhaust system, comprises multi-scrubbers (venturi-scrubber, pool scrubbing, static mixer, metal−fiber filter and molecular sieve). For the particulate radioactive materials, its size affects the removal performance and a number of studies have been performed on the removal effect of radioactive materials. This study has developed a new means of evaluating aerosol removal efficiency. The aerosol number density of each effective diameter (light scattering equivalent diameter) is measured using an optical method, while the decontamination factor (DF) of each effective diameter is evaluated by the inlet outlet number density ratio. While the applicable scope is limited to several conditions (geometry of test section: inner diameter 500 mm × height 8.0 m, nozzle shape and air-water ambient pressure conditions), this study has developed a numerical model which defines aerosol DF as a function of aerosol diameter (d) and submergences (x).

Development of an aerosol decontamination factor evaluation method using an aerosol spectrometer

Energy Technology Data Exchange (ETDEWEB)

Kanai, Taizo, E-mail: t-kanai@criepi.denken.or.jp; Furuya, Masahiro, E-mail: furuya@criepi.denken.or.jp; Arai, Takahiro, E-mail: t-arai@criepi.denken.or.jp; Nishi, Yoshihisa, E-mail: y-nishi@criepi.denken.or.jp

2016-07-15

Highlights: • Aerosol DF of each diameter is evaluable by using optical scattering method. • Outlet aerosol concentration shows exponential decay by the submergence. • This decay constant depends on the aerosol diameter. • Aerosol DF at water scrubber is described by simple equation. - Abstract: During a severe nuclear power plant accident, the release of fission products into containment and an increase in containment pressure are assumed to be possible. When the containment is damaged by excess pressure or temperature, radioactive materials are released. Pressure suppression pools, containment spray systems and a filtered containment venting system (FCVS) reduce containment pressure and reduce the radioactive release into the environment. These devices remove radioactive materials via various mechanisms. Pressure suppression pools remove radioactive materials by pool scrubbing. Spray systems remove radioactive materials by droplet−aerosol interaction. FCVS, which is installed in the exhaust system, comprises multi-scrubbers (venturi-scrubber, pool scrubbing, static mixer, metal−fiber filter and molecular sieve). For the particulate radioactive materials, its size affects the removal performance and a number of studies have been performed on the removal effect of radioactive materials. This study has developed a new means of evaluating aerosol removal efficiency. The aerosol number density of each effective diameter (light scattering equivalent diameter) is measured using an optical method, while the decontamination factor (DF) of each effective diameter is evaluated by the inlet outlet number density ratio. While the applicable scope is limited to several conditions (geometry of test section: inner diameter 500 mm × height 8.0 m, nozzle shape and air-water ambient pressure conditions), this study has developed a numerical model which defines aerosol DF as a function of aerosol diameter (d) and submergences (x).

DARE : Dedicated Aerosols Retrieval Experiment

NARCIS (Netherlands)

Smorenburg, K.; Courrèges-Lacoste, G.B.; Decae, R.; Court, A.J.; Leeuw, G. de; Visser, H.

2004-01-01

At present there is an increasing interest in remote sensing of aerosols from space because of the large impact of aerosols on climate, earth observation and health. TNO has performed a study aimed at improving aerosol characterisation using a space based instrument and state-of-the-art aerosol

Filter-based Aerosol Measurement Experiments using Spherical Aerosol Particles under High Temperature and High Pressure

Energy Technology Data Exchange (ETDEWEB)

Lee, Jong Chan; Jung, Woo Young; Lee, Hyun Chul; Lee, Doo Young [FNC TECH., Yongin (Korea, Republic of)

2016-05-15

Optical Particle Counter (OPC) is used to provide real-time measurement of aerosol concentration and size distribution. Glass fiber membrane filter also be used to measure average mass concentration. Three tests (MTA-1, 2 and 3) have been conducted to study thermal-hydraulic effect, a filtering tendency at given SiO{sub 2} particles. Based on the experimental results, the experiment will be carried out further with a main carrier gas of steam and different aerosol size. The test results will provide representative behavior of the aerosols under various conditions. The aim of the tests, MTA 1, 2 and 3, are to be able to 1) establish the test manuals for aerosol generation, mixing, sampling and measurement system, which defines aerosol preparation, calibration, operating and evaluation method under high pressure and high temperature 2) develop commercial aerosol test modules applicable to the thermal power plant, environmental industry, automobile exhaust gas, chemical plant, HVAC system including nuclear power plant. Based on the test results, sampled aerosol particles in the filter indicate that important parameters affecting aerosol behavior aerosols are 1) system temperature to keep above a evaporation temperature of ethanol and 2) aerosol losses due to the settling by ethanol liquid droplet.

HALIPP. Photocatalysis of tropospheric chemistry by sea salt. Final report; HALIPP. Photokatalyse der Luftchemie durch Seesalz-Aerosole. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Zetzsch, C; Scheer, V; Krueger, H U; Behnke, W

1994-12-31

The reactions of gaseous NO{sub 2} and N{sub 2}O{sub 5} with humidified NaCl-aerosol and humidified mixed NaCl/NaNO{sub 3}- and NaCl/Na{sub 2}SO{sub 4} -aerosols and of gaseous O{sub 3} with humidified sea-salt aerosol were investigated. An upper limit of <10{sup 4} was estimated for the uptake coefficient of NO{sub 2} from our measurements, the uptake coefficient of N{sub 2}O{sub 5} was determined to be 0.032{+-}0.003 (stated error: {+-}2{sigma}). Instead of NOCl reported as a product from NaCl in the literature, HONO is formed from the reaction of NO{sub 2} with deliquescent NaCl aerosol. Gaseaous N{sub 2}O{sub 5} is converted to gaseous CINO{sub 2} below relative humidities of 94%. Only at much higher humidities the formation of 2 HNO{sub 3} increases. No precursors of atomic Cl are observed to be formed from gaseous ozone and pure NaCl-aerosol. Only in the presence of seal-salt aerosols a formation of Cl{sub 2} is found (although not yet quantified). (orig.) [Deutsch] Es wurde die Reaktion von gasfoermigem NO{sub 2} und N{sub 2}O{sub 5} mit feuchtem NaCl- und gemischtem NaCl/NaNO{sub 3}- und NaCl/Na{sub 2}SO{sub 4}- Aerosol sowie von gasfoermigem O{sub 3} mit feuchtem Seesalzaerosol untersucht. Der Uptake-Koeffizient von NO{sub 2} wurde mit kleiner 10{sup -4} abgeschaetzt, der von N{sub 2}O{sub 5} mit 0.032{+-}0.003 (2{sigma}-Fehler) bestimmt. In Gegenwart von NO{sub 2} bildet sich anstelle des in der Literatur angegebenen NOCl gasfoermigs HONO und in Gegenwart von N{sub 2}O{sub 5} unterhalb einer relativen Feuchte von 94% hauptsaechlich gasfoermiges ClNO{sub 2}. Erst in Gegenwart wesentlich hoeherer Feuchten nimmt die Bildung von 2HNO{sub 3} zu. In Gegenwart von Ozon und reinem NaCl-Aerosol bilden sich keine Chloratomvorlaeufer. Erst in Gegenwart von Seesalzaerosolen kommt es zur Bildung von Cl{sub 2}. Eine Quantifizierung dieser letzteren Ergebnisse wurde noch nicht durchgefuehrt. (orig.)

Aerosol Chemical Composition and its Effects on Cloud-Aerosol Interactions during the 2007 CHAPS Experiment

Science.gov (United States)

Lee, Y.; Alexander, L.; Newburn, M.; Jayne, J.; Hubbe, J.; Springston, S.; Senum, G.; Andrews, B.; Ogren, J.; Kleinman, L.; Daum, P.; Berg, L.; Berkowitz, C.

2007-12-01

Chemical composition of submicron aerosol particles was determined using an Aerodyne Time-of-Flight Aerosol Mass Spectrometer (AMS) outfitted on the DOE G-1 aircraft during the Cumulus Humilis Aerosol Processing Study (CHAPS) conducted in Oklahoma City area in June 2007. The primary objective of CHAPS was to investigate the effects of urban emissions on cloud aerosol interactions as a function of processing of the emissions. Aerosol composition was typically determined at three different altitudes: below, in, and above cloud, in both upwind and downwind regions of the urban area. Aerosols were sampled from an isokinetic inlet with an upper size cut-off of ~1.5 micrometer. During cloud passages, the AMS also sampled particles that were dried from cloud droplets collected using a counter-flow virtual impactor (CVI) sampler. The aerosol mass concentrations were typically below 10 microgram per cubic meter, and were dominated by organics and sulfate. Ammonium was often less than required for complete neutralization of sulfate. Aerosol nitrate levels were very low. We noted that nitrate levels were significantly enhanced in cloud droplets compared to aerosols, most likely resulting from dissolution of gaseous nitric acid. Organic to sulfate ratios appeared to be lower in cloud droplets than in aerosols, suggesting cloud condensation nuclei properties of aerosol particles might be affected by loading and nature of the organic components in aerosols. In-cloud formation of sulfate was considered unimportant because of the very low SO2 concentration in the region. A detailed examination of the sources of the aerosol organic components (based on hydrocarbons determined using a proton transfer reaction mass spectrometer) and their effects on cloud formation as a function of atmospheric processing (based on the degree of oxidation of the organic components) will be presented.

Water content of aged aerosol

OpenAIRE

G. J. Engelhart; L. Hildebrandt; E. Kostenidou; N. Mihalopoulos; N. M. Donahue; S. N. Pandis

2010-01-01

The composition and physical properties of aged atmospheric aerosol were characterized at a remote sampling site on the northern coast of Crete, Greece during the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-2008). A reduced Dry-Ambient Aerosol Size Spectrometer (DAASS) was deployed to measure the aerosol water content and volumetric growth factor of fine particulate matter. The particles remained wet even at relative humidity (RH) as low as 20%. The aerosol was acidic during mo...

Aerosol effects on UV radiation

International Nuclear Information System (INIS)

Koepke, P.; Reuder, J.; Schwander, H.

2000-01-01

The reduction of erythemally weighted UV-irradiance (given as UV index, UVI) due to aerosols is analyzed by variation of the tropospheric particles in a wide, but realistic range. Varied are amount and composition of the particles and relative humidity and thickness of the mixing layer. The reduction of UVI increases with aerosol optical depth and the UV change is around 10% for a change aerosol optical depth from 0.25 to 0.1 and 0.4 respectively. Since both aerosol absorption and scattering are of relevance, the aerosol effect depends besides total aerosol amount on relative amount of soot and on relative humidity

Aerosol sampler for analysis of fine and ultrafine aerosols

Czech Academy of Sciences Publication Activity Database

Mikuška, Pavel; Čapka, Lukáš; Večeřa, Zbyněk

2018-01-01

Roč. 1020 (2018), s. 123-133 ISSN 0003-2670 R&D Projects: GA ČR(CZ) GA14-25558S Institutional support: RVO:68081715 Keywords : atmospheric aerosols * aerosol collection * chemical composition Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.950, year: 2016

Aerosol retrieval algorithm for the characterization of local aerosol using MODIS L1B data

International Nuclear Information System (INIS)

Wahab, A M; Sarker, M L R

2014-01-01

Atmospheric aerosol plays an important role in radiation budget, climate change, hydrology and visibility. However, it has immense effect on the air quality, especially in densely populated areas where high concentration of aerosol is associated with premature death and the decrease of life expectancy. Therefore, an accurate estimation of aerosol with spatial distribution is essential, and satellite data has increasingly been used to estimate aerosol optical depth (AOD). Aerosol product (AOD) from Moderate Resolution Imaging Spectroradiometer (MODIS) data is available at global scale but problems arise due to low spatial resolution, time-lag availability of AOD product as well as the use of generalized aerosol models in retrieval algorithm instead of local aerosol models. This study focuses on the aerosol retrieval algorithm for the characterization of local aerosol in Hong Kong for a long period of time (2006-2011) using high spatial resolution MODIS level 1B data (500 m resolution) and taking into account the local aerosol models. Two methods (dark dense vegetation and MODIS land surface reflectance product) were used for the estimation of the surface reflectance over land and Santa Barbara DISORT Radiative Transfer (SBDART) code was used to construct LUTs for calculating the aerosol reflectance as a function of AOD. Results indicate that AOD can be estimated at the local scale from high resolution MODIS data, and the obtained accuracy (ca. 87%) is very much comparable with the accuracy obtained from other studies (80%-95%) for AOD estimation

Contribution des TICs à l'abandon des mutilations génitales ...

International Development Research Centre (IDRC) Digital Library (Canada)

Contribution des TIC à l'abandon des MGF en Afrique de l'Ouest francophone : rôle des jeunes citoyennes; rapport technique no. 5 (rapport technique final), 18 octobre 2008 - 31 mars 2009. Download PDF. Related content. New website will help record vital life events to improve access to services for all. A new website ...

utilisation des donnees pour l'evaluation de l'heterogeneite des sols

African Journals Online (AJOL)

AISA

étude a permis de caractériser l'hétérogénéité des sols ferrallitiques, à travers sa couleur. Mots-clés : Couleur ... ainsi qu'à l'application des recommandations des doses de fertilisant. ..... de « système sol » en zone de contact forêt- savane du ...

Comprehensive Measurement of Atmospheric Aerosols with a Wide Range Aerosol Spectrometer

International Nuclear Information System (INIS)

Keck, L; Pesch, M; Grimm, H

2011-01-01

A wide range aerosol spectrometer (WRAS) was used for comprehensive long term measurements of aerosol size distributions. The system combines the results of an optical aerosol spectrometer with the results of a Scanning Mobility Particle Sizer (SMPS) to record essentially the full size range (5 nm - 32 μm) of atmospheric particles in 72 channels. Measurements were carried out over one year (2009) at the Global Atmospheric Watch (GAW)-Station Hohenpeissenberg, Bavaria. Total particle number concentrations obtained from the aerosol size distributions were compared to the total number concentrations measured by a Condensation Particle Counter (CPC). The comparison showed an excellent agreement of the data. The high time resolution of 5 minutes allows the combination of the measured size distributions with meteorological data and correlations to gaseous pollutants (CO, NOx and SO2). A good correlation of particle number and CO concentrations was found for long distance transported small particles, which were probably mainly soot particles. Correlations to NOx were observed for aerosols from local sources such as traffic emissions. The formation of secondary aerosols from gaseous precursors was also observed. Episodes of relatively high concentration of particles in the range of 2-3 μm were probably caused by pollen.

The DRAGON aerosol research facility to study aerosol behaviour for reactor safety applications

International Nuclear Information System (INIS)

Suckow, Detlef; Guentay, Salih

2008-01-01

During a severe accident in a nuclear power plant fission products are expected to be released in form of aerosol particles and droplets. To study the behaviour of safety relevant reactor components under aerosol loads and prototypical severe accident conditions the multi-purpose aerosol generation facility DRAGON is used since 1994 for several projects. DRAGON can generate aerosol particles by the evaporation-condensation technique using a plasma torch system, fluidized bed and atomization of particles suspended in a liquid. Soluble, hygroscopic aerosol (i.e. CsOH) and insoluble aerosol particles (i.e. SnO 2 , TiO 2 ) or mixtures of them can be used. DRAGON uses state-of-the-art thermal-hydraulic, data acquisition and aerosol measurement techniques and is mainly composed of a mixing chamber, the plasma torch system, a steam generator, nitrogen gas and compressed air delivery systems, several aerosol delivery piping, gas heaters and several auxiliary systems to provide vacuum, coolant and off-gas treatment. The facility can be operated at system pressure of 5 bars, temperatures of 300 deg. C, flow rates of non-condensable gas of 900 kg/h and steam of 270 kg/h, respectively. A test section under investigation is attached to DRAGON. The paper summarizes and demonstrates with the help of two project examples the capabilities of DRAGON for reactor safety studies. (authors)

Chronology of fluid paleo-circulations in mesozoic formations on the site of Bure by U/Pb dating of secondary calcites

International Nuclear Information System (INIS)

Pisapia, C.; Deschamps, P.; Hamelin, B.; Pisapia, C.; Buschaert, S.

2009-01-01

The French national agency for the management of radioactive wastes (ANDRA, Agence nationale pour la gestion des dechets radioactifs) has developed an underground research laboratory in mesozoic formations of the eastern Parisian Basin in order to test the design of radioactive waste storage site in sedimentary formations. The authors report an investigation which aims at understanding the site paleo-hydrology. This investigation is based on the disintegration chain of uranium and on U/Th and U/Pb dating methods, and aims at giving a precise chronology of the different phases of precipitation of centimetric and millimetric secondary calcites sampled on this site

Evaluating Global Aerosol Models and Aerosol and Water Vapor Properties Near Clouds

Energy Technology Data Exchange (ETDEWEB)

Richard A. Ferrare; David D. Turner

2011-09-01

Project goals: (1) Use the routine surface and airborne measurements at the ARM SGP site, and the routine surface measurements at the NSA site, to continue our evaluations of model aerosol simulations; (2) Determine the degree to which the Raman lidar measurements of water vapor and aerosol scattering and extinction can be used to remotely characterize the aerosol humidification factor; (3) Use the high temporal resolution CARL data to examine how aerosol properties vary near clouds; and (4) Use the high temporal resolution CARL and Atmospheric Emitted Radiance Interferometer (AERI) data to quantify entrainment in optically thin continental cumulus clouds.

The prospection of uranium and thorium ores in desert country and in equatorial forest regions of the Union Francaise; La prospection des minerais d'uranium et de thorium dans les pays desertiques et dans les regions de foret equatoriale de l'Union Francaise

Energy Technology Data Exchange (ETDEWEB)

Lecoq, J.J.; Bigotte, G.; Hinault, J.; Leconte, J.R. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1958-07-01

Since it was founded, the D.R.E.M. has carried out important prospection work in the overseas territories which now make up the Communaute Francaise. This work, now involving almost a million km{sup 2}, represents an experiment scarcely equalled throughout the world. Research in these territories presents both general and technical difficulties, which are especially severe in countries with extreme climates: deserts or dense equatorial forests. The adaptation of various methods of radioactive ore prospection to these regions is described, and also the results obtained. Three particular examples are given in detail: - general exploration in the Hoggar, and reconnoitring of particular indications; - general exploration in the equatorial forest of French Guyana; - detailed study of a sign of uraniferous occurrences and its surroundings in the equatorial zone (Mounana deposit near Franceville (Gabon)). (author) [French] Depuis sa creation, la D.R.E.M. poursuit un effort important de prospection dans les territoires d'outre-mer qui constituent maintenant la Communaute Fran ise. Ces travaux qui interessent maintenant pres d'un million de km{sup 2} constituent une experience qui a peu d'equivalent dans le monde. Les recherches dans ces territoires presentent des difficultes, sur le plan general et sur le plan technique, particulierement ardues dans les pays a climats excessifs: deserts ou forets equatoriales denses. On decrit l'adaptation des diverses methodes de prospection des minerais radioactifs a ces regions et les resultats qu'elles ont fournis. Trois exemples particuliers sont donnes en detail: - Exploration generale au Hoggar, et reconnaissance d'indices particuliers. - Exploration generale en foret equatoriale en Guyane fran ise. - Etude detaillee d'un indice uranifere et de ses environs en zone equatoriale (gisement de Mounana pres de France-ville (Gabon)). (auteur)

Aerosols CFA 97

International Nuclear Information System (INIS)

Anon.

1998-01-01

During the thirteen congress on aerosols several papers were presented about the behaviour of radioactive aerosols and their impact on environment, or the exposure to radon and to its daughters, the measurement of the size of the particulates of the short-lived radon daughters and two papers about the behaviour of aerosols in containment during a fission products release in the primary circuit and susceptible to be released in atmosphere in the case of containment failure. (N.C.)

Les lexiques des jeunes dans les discours écrits des blogs : pour une approche descriptive

Directory of Open Access Journals (Sweden)

Lorenz Paulina

2014-07-01

Full Text Available S’il ne faut pas confondre ce qui est appelé communément « langage SMS » et « langage des jeunes », nous avancerons toutefois que les pratiques langagières écrites des jeunes sur les supports modernes de communication, et notamment dans les blogs, présentent des particularités encore peu étudiées. Les traits observables les plus saillants sont ceux de la morphologie graphique, mais il n’en reste pas moins que certains jeunes utilisent des lexiques particuliers dans les blogs qui méritent une attention particulière. Nous nous proposons donc d’étudier les différents lexiques utilisés par des jeunes de 12 à 22 ans dans les blogs de la plateforme skyrock.com aux niveaux de sa diversité, de ses usages sémantiques variable d’un scripteur à l’autre pour un même mot, et de ses particularités morphosyntaxiques. En effet, nous observerons des lexiques divers allant des lexiques perçus comme relevant des cités à des lexiques perçus comme étant « branchés-jeunes », ou encore à des lexiques propres aux supports modernes de communication. Ainsi, nous analyserons des lexiques variés dans leurs usages écrits tels que bolos, bédave, gérer, ouf, tigen, ou encore des lexiques empruntés tels que mouv, full, etc., ainsi que des emplois particuliers de séquences autonomes comme lol. Quelques questions périphériques complèteront notre analyse telle que celles qui concerne l’influence des usages lexicaux entre pairs et le savoir partagé, la distinction de différentes communautés en fonction des lexiques utilisés, ou encore la variabilité des représentations graphiques d’un même mot.

Ion exchange in ultramarine blue. Studies using radioactive tracers (1963); Echanges d'ion dans le bleu d'outremer, etudies au moyen des traceurs radioactifs (1963)

Energy Technology Data Exchange (ETDEWEB)

Goenvec, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1963-05-15

A study has been made of the exchange reaction between the constituent sodium in ultramarine blue, and silver in the form of a silver nitrate solution; an attempt hat been made to define the influence of the solvent of the silver nitrate on the kinetics of the exchange reaction. Five solvents have been used: water, methanol, ethanol, n-propanol and acetone. The reaction rates are controlled by a diffusion process inside the ultramarine grains, whatever the solvent used. It seems that the solvated ionic radius of the diffusing ion is one of the factors influencing the rate of reaction. Furthermore, the solvated ionic radius varies with temperature; this variation is different for each solvent and should explain the differences observed in the activation energies. (author) [French] Nous avons etudie la reaction d'echange entre le sodium de constitution du bleu d'outremer et l'argent sous forme de nitrate d'argent en solution; nous avons essaye de definir l'influence du solvant du nitrate d'argent sur la cinetique de la reaction d'echange. Nous avons utilise cinq solvant: l'eau, le methanol, l'ethanol, le n-propanol et l'acetone. Les vitesses de reaction sont controlees par un processus de diffusion a l'interieur des grains d'outremer quel que soit le solvant. Il semble que le rayon ionique solvate de l'ion diffusant est l'un des facteurs qui influencent la vitesse de reaction. D'autre part, le rayon ionique solvate varie avec la temperature, cette variation est differente pour chaque solvant et doit pouvoir expliquer les differences d'energie d'activation constatees. (auteur)

Determination of mineral radioactive strontium-{sup 90} in urines; Recherche du strontium mineral radioactif {sup 90}Sr dans les urines

Energy Technology Data Exchange (ETDEWEB)

Jeanmaire, L; Jammet, H; Bertrand, S [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

An analytical procedure for radioactive strontium in urine is described. As a first step, a precipitation of calcium oxalate performed on the urine, allows to detect the presence of various fission products and particularly of strontium which is carried by the precipitate. Strontium can then be selectively separated on ion exchange resins. By studying the growth curve of {beta} activity, it is possible to determine the activities which may be attributed to {sup 89}Sr and {sup 90}Sr respectively. (author) [French] Cet article decrit une technique de dosage du strontium radioactif dans les urines. Dans un premier stade, une precipitation d'oxalate de calcium effectuee sur l'urine permet de deceler la presence de differents produits de fission et en particulier du strontium qui est entraine sur ce precipite. Il est possible ensuite de separer selectivement le strontium au moyen de resines echangeuses d'ions. L'examen de le courbe de croissance de l'activite {beta} permet de determiner les activites dues respectivement a {sup 89}Sr et {sup 90}Sr. (auteur)

The ion–aerosol interactions from the ion mobility and aerosol ...

Indian Academy of Sciences (India)

2005-02-18

aerosol interactions from the ion mobility and aerosol particle size distribution measurements on January 17 and February 18, 2005 at Maitri, Antarctica – A case study. Devendraa Siingh Vimlesh Pant A K Kamra. Volume 120 Issue 4 August ...

Contrôle des circuits auxiliaires des P.F.W. (arret machine 2004/2006)

CERN Document Server

Ottaviani, J

2005-01-01

Les PFW sont des nappes polaires installées sur les pôles des aimants du PS. Elles sont au nombre de 4 par unité d’aimant et constituées d’un circuit principal (dans lequel circule le courant désiré selon le cycle magnétique utilisé) et de circuits auxiliaires. Les circuits auxiliaires sont des enroulements de correction (boucles de tour et “pick-up” brasés sur les enroulements principaux). Pendant la variation du champ magnétique de l’aimant PS, on utilise des tensions induites dans ces circuits auxiliaires pour corriger les erreurs de champ dues aux pertes par courants de Foucault dans la chambre à vide. Chaque année, pendant l’arrêt machine, on vérifie si les caractéristiques des circuits auxiliaires correspondent aux normes (mesures des résistances des boucles de tours, résistances entre “pick-up” et isolation des circuits) afin de faire un suivi. Les 404 PFW sont ainsi vérifiées. Dans cette note, on ne relèvera que les PFW ayant des défauts (valeurs hors tolérances, ...

The cholesterol space of the rat; L'espace cholesterol du rat

Energy Technology Data Exchange (ETDEWEB)

Chevallier, F [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1959-07-01

The experiments consisted in feeding daily to rats the same mass of radioactive cholesterol, over variable time intervals. From the evolution of the specific radioactivity of cholesterol carbon-14 in the organs as a function of time, information relative to the transport of cholesterol in the organism may be obtained. 1) The cholesterol space, defined as the group of molecules capable of being transferred from the organs into the serum and vice versa, represents at the most 50 per cent of the total cholesterol of the adult rat. 2) The incessant interchange between the tissual and the serum cholesterol renews entirely or for the most part the cholesterol molecules contained in the following organs: spleen, heart, adipose tissue, suprarenal glands, lungs, bone marrow, liver, erythrocytes. For a second group of organs: skin, testicles, kidneys, colon, bones, muscles, only a fraction of their cholesterol is renewable by this process. No transfer can be detected at the level of the brain. 3) The relative speeds of the various means of appearance (absorption, synthesis) and disappearance (excretion, transformation) of the cholesterol from its space are such that a stationary isotopic state is established around the eighth day, when the animal absorbs 5 milligrams of radioactive cholesterol daily. (author) [French] Les experiences ont consiste a faire ingerer quotidiennement une meme masse de cholesterol radioactif a des rats, durant des laps de temps variables. L'evolution de la radioactivite specifique du carbone-14 du cholesterol des organes en fonction du temps permet d'obtenir des renseignements relatifs au transport du cholesterol dans l'organisme. 1) L'espace cholesterol defini comme l'ensemble des molecules susceptibles d'etre transferees des organes dans le serum, et vice-versa, represente au plus 50 pour cent du cholesterol total du rat adulte. 2) Le va et vient incessant entre le cholesterol tissulaire et le cholesterol serique renouvelle en totalite ou en

Aerosol Observing System (AOS) Handbook

Energy Technology Data Exchange (ETDEWEB)

Jefferson, A

2011-01-17

The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

Etat des lieux des soins de premier recours des malades mentaux à Antananarivo : étude rétrospective

Science.gov (United States)

Bakohariliva, Hasina Andrianarivony; Rafehivola, Imisanavalona Hanitrinihaja; Raobelle, Evah Norotiana; Raharivelo, Adeline; Rajaonarison, Bertille Hortense

2018-01-01

Résumé Religion et guérisseurs traditionnels occupent encore une place prépondérante dans la prise en charge des maladies mentales à Madagascar. Ainsi, nous nous sommes fixés comme objectif d'établir un état des lieux sur les soins de premier recours des malades mentaux. Nous avons mené une étude rétrospective descriptive s'étalant sur une période de 16 mois allant de janvier 2014 en avril 2015 au sein du service de psychiatrie du CHU de Befelatanana à Antananarivo. La prévalence des psychoses était de 25%. Le genre féminin (53%), l'ethnie merina (77%), les étudiants (45%), le niveau d'étude secondaire (40%), les célibataires (72%), la religion protestante (45%), ainsi que le niveau socio-économique moyen (57,5%) étaient prédominants. Dans les paramètres cliniques, le mode de début brutal (52%), le premier recours à la religion (40%), la présence d'antécédents des cas similaire (90%), étaient majoritaires. La schizophrénie était la pathologie la plus rencontrée dans la moitié des cas. Le délai d'amélioration en cas de traitement religieux et traditionnels était dans la moitié des cas de plus de 10 jours d'hospitalisation. Les patients ayant reçu une prise en charge psychiatrique en premier recours, étaient améliorés dans 75 % cas en moins de 10jours. Le retard du recours aux soins psychiatriques est une réalité à Madagascar qui aggrave le pronostic des psychoses. PMID:29632623

Accès à l'eau : des solutions techniques et sociales aident des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Grâce à la modélisation par ordinateur faisant appel à des techniques de pointe et à la consultation des collectivités, l'organisme bolivien Agua Sustentable a trouvé des solutions politiques à des conflits qui auraient pu s'avérer désastreux au sujet de l'accès à l'eau. Cet organisme de recherche subventionné par le CRDI a ...

Le Débat des semences

International Development Research Centre (IDRC) Digital Library (Canada)

Solutions pour les lois nationales régissant le contrôle des ressources génétiques et des ...... des pouvoirs) qui reconnaissent, dans une certaine mesure, les droits de gestion collectifs des ...... documentés, les performances physiques, etc.

Aerosol-foam interaction experiments

International Nuclear Information System (INIS)

Ball, M.H.E.; Luscombe, C.DeM.; Mitchell, J.P.

1990-03-01

Foam treatment offers the potential to clean gas streams containing radioactive particles. A large decontamination factor has been claimed for the removal of airborne plutonium dust when spraying a commercially available foam on the walls and horizontal surfaces of an alpha-active room. Experiments have been designed and undertaken to reproduce these conditions with a non-radioactive simulant aerosol. Careful measurements of aerosol concentrations with and without foam treatment failed to provide convincing evidence to support the earlier observation. The foam may not have been as well mixed with the aerosol in the present studies. Further work is required to explore more efficient mixing methods, including systems in which the aerosol steam is passed through the foam, rather than merely spraying foam into the path of the aerosol. (author)

Arctic Aerosols and Sources

DEFF Research Database (Denmark)

Nielsen, Ingeborg Elbæk

2017-01-01

Since the Industrial Revolution, the anthropogenic emission of greenhouse gases has been increasing, leading to a rise in the global temperature. Particularly in the Arctic, climate change is having serious impact where the average temperature has increased almost twice as much as the global during......, ammonium, black carbon, and trace metals. This PhD dissertation studies Arctic aerosols and their sources, with special focus on black carbon, attempting to increase the knowledge about aerosols’ effect on the climate in an Arctic content. The first part of the dissertation examines the diversity...... of aerosol emissions from an important anthropogenic aerosol source: residential wood combustion. The second part, characterizes the chemical and physical composition of aerosols while investigating sources of aerosols in the Arctic. The main instrument used in this research has been the state...

The Impact of Aerosol Particle Mixing State on the Hygroscopicity of Sea Spray Aerosol.

Science.gov (United States)

Schill, Steven R; Collins, Douglas B; Lee, Christopher; Morris, Holly S; Novak, Gordon A; Prather, Kimberly A; Quinn, Patricia K; Sultana, Camille M; Tivanski, Alexei V; Zimmermann, Kathryn; Cappa, Christopher D; Bertram, Timothy H

2015-06-24

Aerosol particles influence global climate by determining cloud droplet number concentrations, brightness, and lifetime. Primary aerosol particles, such as those produced from breaking waves in the ocean, display large particle-particle variability in chemical composition, morphology, and physical phase state, all of which affect the ability of individual particles to accommodate water and grow into cloud droplets. Despite such diversity in molecular composition, there is a paucity of methods available to assess how particle-particle variability in chemistry translates to corresponding differences in aerosol hygroscopicity. Here, an approach has been developed that allows for characterization of the distribution of aerosol hygroscopicity within a chemically complex population of atmospheric particles. This methodology, when applied to the interpretation of nascent sea spray aerosol, provides a quantitative framework for connecting results obtained using molecular mimics generated in the laboratory with chemically complex ambient aerosol. We show that nascent sea spray aerosol, generated in situ in the Atlantic Ocean, displays a broad distribution of particle hygroscopicities, indicative of a correspondingly broad distribution of particle chemical compositions. Molecular mimics of sea spray aerosol organic material were used in the laboratory to assess the volume fractions and molecular functionality required to suppress sea spray aerosol hygroscopicity to the extent indicated by field observations. We show that proper accounting for the distribution and diversity in particle hygroscopicity and composition are important to the assessment of particle impacts on clouds and global climate.

Primary aerosol and secondary inorganic aerosol budget over the Mediterranean Basin during 2012 and 2013

Science.gov (United States)

Guth, Jonathan; Marécal, Virginie; Josse, Béatrice; Arteta, Joaquim; Hamer, Paul

2018-04-01

In the frame of the Chemistry-Aerosol Mediterranean Experiment (ChArMEx), we analyse the budget of primary aerosols and secondary inorganic aerosols over the Mediterranean Basin during the years 2012 and 2013. To do this, we use two year-long numerical simulations with the chemistry-transport model MOCAGE validated against satellite- and ground-based measurements. The budget is presented on an annual and a monthly basis on a domain covering 29 to 47° N latitude and 10° W to 38° E longitude. The years 2012 and 2013 show similar seasonal variations. The desert dust is the main contributor to the annual aerosol burden in the Mediterranean region with a peak in spring, and sea salt being the second most important contributor. The secondary inorganic aerosols, taken as a whole, contribute a similar level to sea salt. The results show that all of the considered aerosol types, except for sea salt aerosols, experience net export out of our Mediterranean Basin model domain, and thus this area should be considered as a source region for aerosols globally. Our study showed that 11 % of the desert dust, 22.8 to 39.5 % of the carbonaceous aerosols, 35 % of the sulfate and 9 % of the ammonium emitted or produced into the study domain are exported. The main sources of variability for aerosols between 2012 and 2013 are weather-related variations, acting on emissions processes, and the episodic import of aerosols from North American fires. In order to assess the importance of the anthropogenic emissions of the marine and the coastal areas which are central for the economy of the Mediterranean Basin, we made a sensitivity test simulation. This simulation is similar to the reference simulation but with the removal of the international shipping emissions and the anthropogenic emissions over a 50 km wide band inland along the coast. We showed that around 30 % of the emissions of carbonaceous aerosols and 35 to 60 % of the exported carbonaceous aerosols originates from the marine and

Stable generator of polydisperse aerosol

Czech Academy of Sciences Publication Activity Database

Mikuška, Pavel

2001-01-01

Roč. 32, Suppl. 1 (2001), s. S823-S824 ISSN 0021-8502. [European Aerosol Conference 2001. Leipzig, 03.09.2001-07.09.2001] R&D Projects: GA AV ČR IAA4031105 Institutional research plan: CEZ:AV0Z4031919 Keywords : aerosol generator * fine aerosol * polydisperse aerosol Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.605, year: 2001

Performances de ponte et qualité des oeufs des poules pondeuses ...

African Journals Online (AJOL)

Les performances de ponte et la qualité des oeufs de 216 poules pondeuses ISA Brown âgées de 21 semaines ont été déterminées en les alimentant avec des rations contenant des feuilles séchées de manioc (Manihot esculenta, Crantz). Pendant douze semaines, trois groupes de 72 poules chacun (réparties en trois ...

Freins et leviers à la diversification des cultures : étude au niveau des exploitations agricoles et des filières

Directory of Open Access Journals (Sweden)

Meynard Jean-Marc

2013-07-01

Full Text Available La diversification des cultures est souvent présentée comme un levier d’action pour accroître la durabilité des systèmes de production agricoles. Bien raisonnée, elle favorise en effet une réduction de l’usage d’intrants extérieurs à l’exploitation – pesticides, engrais, eau – et des nuisances environnementales associées à leur utilisation excessive. À l’inverse, la simplification des systèmes de culture engagée depuis plus de 40 ans s’est accompagnée d’un recours croissant aux intrants. Cependant, malgré son intérêt pour les systèmes de production en termes de durabilité écologique mais aussi économique (répartition des risques, et son inscription dans divers plans et dispositifs incitatifs, la diversification des cultures progresse peu. Les ministères en charge de l’agriculture et de l’environnement ont donc commandé à l’INRA une étude visant à identifier les freins à la diversification des cultures en France et les leviers mobilisables, par les pouvoirs publics notamment, pour la favoriser. L’hypothèse de travail est que ces freins relèvent du fonctionnement global du système agro-industriel, et de la capacité de développement de filières valorisant les cultures de diversification. L’étude a examiné un certain nombre de cas représentatifs de la diversité des filières et notamment de leurs modes d’organisation, qui déterminent la coordination et l’engagement des acteurs économiques impliqués dans le développement d’une culture de diversification.

Impact écotoxicologique de mélanges de pesticides sur des fonctions microbiennes des sols : apport d’une prise en compte écologique dans l’évaluation des risques

OpenAIRE

Devers-Lamrani, Marion; Rouard, Nadine; Cheviron, Nathalie; Grondin, Virginie; Martin-Laurent, Fabrice

2015-01-01

L’utilisation de pesticides permet d’assurer la qualité de la production végétale mais elle contribue à la contamination des sols et des eaux et produit des effets sur des organismes noncibles. L’évaluation des risques requièrent actuellement une meilleure prise en compte des effets des pesticides sur le fonctionnement des écosystèmes. Or, les démarches et indicateurs classiques manquent de représentativité écologique. La fonction microbienne de biodégradation des pesticides est essentielle c...

Mesure de la masse volumique des particules des eaux résiduaires urbaines : protocole et évaluation des incertitudes

OpenAIRE

RUBAN, Gwenaël; LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES - LCPC

2004-01-01

La connaissance de la masse volumique des particules des eaux résiduaires urbaines est intéressante notamment pour l'étude de leur traitement par décantation ainsi que des relations entre concentrations en matières en suspension et paramètres optiques (turbidimétrie).Une étude des différentes méthodes de mesure de la masse volumique appliquées aux eaux résiduaires a été effectuée par G. Chebbo (1992). Il en a conclu que le pycnomètre à gaz type Beckman est le seul appareil donnant satisfactio...

Problèmes entomologiques en replantation des palmeraies et des cocoteraies

Directory of Open Access Journals (Sweden)

Mariau Dominique

2000-03-01

Full Text Available C’est aux alentours de la vingt-cinquième année que l’on envisage de replanter une palmeraie. C’est en effet vers cet âge que commencent à se poser des problèmes de récolte en raison de la taille des palmiers. En un quart de siècle, l’amélioration génétique aura suffisamment fait de progrès pour escompter un gain de production de l’ordre de 20%. Enfin, dans certaines situations, plusieurs maladies ont pu affecter les vieilles palmeraies. Avec de 15 à 25% d’arbres manquants, principalement lorsque ceux-ci se présentent sous la forme de taches, une diminution de la production se fait nettement sentir. Cela peut, par exemple, être le cas avec les maladies de la fusariose en Afrique de l’Ouest, lorsque la palmeraie n’a pas été plantée avec du matériel végétal tolérant, ou du ganoderma en Malaisie. Le renouvellement des cocoteraies se fait avec un espace de temps beaucoup plus long. En effet, la récolte des noix peut se faire au sol et la hauteur des cocotiers n’est donc pas un facteur limitant. Par ailleurs, la majorité des cocoteraies étant sous la forme de petites plantations villageoises, les agriculteurs rechignent toujours à abattre leurs cocotiers, même si des semences potentiellement plus productives leurs sont proposées. Ce sont les raisons pour lesquelles les cocoteraies de 50 ans et plus représentent la règle. L’abattage d’une plantation de palmiers à huile ou de cocotiers constitue naturellement un changement brutal de l’environnement, ce qui a des conséquences importantes notamment sur l’entomofaune, parmi laquelle des ravageurs majeurs ainsi que leurs ennemis naturels.

Aerosol counterflow two-jets unit for continuous measurement of the soluble fraction of atmospheric aerosols.

Science.gov (United States)

Mikuska, Pavel; Vecera, Zbynek

2005-09-01

A new type of aerosol collector employing a liquid at laboratory temperature for continuous sampling of atmospheric particles is described. The collector operates on the principle of a Venturi scrubber. Sampled air flows at high linear velocity through two Venturi nozzles "atomizing" the liquid to form two jets of a polydisperse aerosol of fine droplets situated against each other. Counterflow jets of droplets collide, and within this process, the aerosol particles are captured into dispersed liquid. Under optimum conditions (air flow rate of 5 L/min and water flow rate of 2 mL/min), aerosol particles down to 0.3 microm in diameter are quantitatively collected in the collector into deionized water while the collection efficiency of smaller particles decreases. There is very little loss of fine aerosol within the aerosol counterflow two-jets unit (ACTJU). Coupling of the aerosol collector with an annular diffusion denuder located upstream of the collector ensures an artifact-free sampling of atmospheric aerosols. Operation of the ACTJU in combination with on-line detection devices allows in situ automated analysis of water-soluble aerosol species (e.g., NO2-, NO3-)with high time resolution (as high as 1 s). Under the optimum conditions, the limit of detection for particulate nitrite and nitrate is 28 and 77 ng/m(3), respectively. The instrument is sufficiently rugged for its application at routine monitoring of aerosol composition in the real time.

Innovation pour la santé des mères et des enfants d'Afrique

International Development Research Centre (IDRC) Digital Library (Canada)

Corey Piccioni

... détermineront les interventions devant absolument faire partie de la formation des travailleurs de santé communautaire. Cela pourrait comprendre des régimes de vitamines prénatals et des billets de transport à des établissements de santé pour le dépistage de troubles d'hypertension ou d'infection au VIH, entre autres.

American Association for Aerosol Research (AAAR) `95

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-31

The Fourteenth annual meeting of the American Association for Aerosol Research was held October 9-13, 1995 at Westin William Penn Hotel in Pittsburgh, PA. This volume contains the abstracts of the papers and poster sessions presented at this meeting, grouped by the session in which they were presented as follows: Radiation Effects; Aerosol Deposition; Collision Simulations and Microphysical Behavior; Filtration Theory and Measurements; Materials Synthesis; Radioactive and Nuclear Aerosols; Aerosol Formation, Thermodynamic Properties, and Behavior; Particle Contamination Issues in the Computer Industry; Pharmaceutical Aerosol Technology; Modeling Global/Regional Aerosols; Visibility; Respiratory Deposition; Biomass and Biogenic Aerosols; Aerosol Dynamics; Atmospheric Aerosols.

Isolement et identification des levures.

Directory of Open Access Journals (Sweden)

S. DOMERCQ

1967-06-01

Full Text Available La fermentation du moût de raisin est assurée par les levures qui se trouvent sur la pellicule du raisin, sur les rafles, et aussi, par celles qui envahissent le matériel de vendange et de vinification dès que la récolte est commencée. L'apparition deLa fermentation du moût de raisin est assurée par les levures qui se trouvent sur la pellicule du raisin, sur les rafles, et aussi, par celles qui envahissent le matériel de vendange et de vinification dès que la récolte est commencée. L'apparition des signes de la fermentation est spontanée. La fermentation est rapide dans la majorité des cas, si elle devient trop violente et que la température s'élève dangeureusement, il faut la « canaliser », la calmer. Des accidents peuvent se produire; des arrêts de fermentation laissant des sucres non fermentés pouvant être attaqués par d'autres microorganismes, des développements de levures formant des substances nuisibles à la qualité; par la suite, il s'agit d'obtenir la stabilité du vin, en particulier, éviter les refermentations des vins doux. L'étude de ces problèmes nécessite une étude préliminaire, celle des levures responsables de la fermentation alcoolique du jus de raisin, qui ne peut être faite que sur des cultures pures, isolées au préalable à l'aide de prélèvements soigneusement réalisés.s signes de la fermentation est spontanée. La fermentation est rapide dans la majorité des cas, si elle devient trop violente et que la température s'élève dangeureusement, il faut la « canaliser », la calmer. Des accidents peuvent se produire; des arrêts de fermentation laissant des sucres non fermentés pouvant être attaqués par d'autres microorganismes, des développements de levures formant des substances nuisibles à la qualité; par la suite, il s'agit d'obtenir la stabilité du vin, en particulier, éviter les refermentations des vins doux. L'étude de ces problèmes nécessite une étude pr

Caesium absorption by barley - influence of its retention by the soil - competitive action of potassium; Absorption du cesium par l'orge - influence de sa retention dans le sol - action competitive du potassium

Energy Technology Data Exchange (ETDEWEB)

Ferron-Trosseau, F. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-06-01

plants such as rice and cress growing on flooded soils. Radio-active caesium however incorporated without carrier into a soil of medium-exchange capacity (of about 150 milli-equivalents per kilo) presents relatively little danger because of the close interdependence of the radioactive caesium take-up from the soil by the plants and its retention by the soil. Our research has made it possible furthermore to examine the value of various partial decontamination methods for soils proposed by certain atomic scientists: just as isotopic dilution appears totally inadequate for this purpose, so does it seems that the addition of potassium salts in amounts greater than nutritive optimum is incapable of reducing the absorption of radioactive caesium by the plant. (author) [French] Nous avons recherche, dans divers milieux de culture, comment l'absorption du cesium par l'orge varie avec sa concentration et comment cette absorption peut etre concurrencee par un cation alcalin voisin,le potassium. En outre, nous avons considere la distribution du cesium dans le sol - notamment du cesium radioactif - entre terre et solution, en fonction du taux de cesium. De notre etude ressort une nette opposition entre le comportement de l'orge vis a vis du cesium d'une solution nutritive et vis a vis du cesium d'un sol: sur solution nutritive, la fraction du cesium (radioactif et stable) absorbee par l'orge demeure pratiquement constante en presence de proportions croissantes (relativement petites) de cesium stable; sur sol, la fraction du cesium radioactif absorbee par l'orge a augmente en meme temps que le taux (relativement petit) de cesium stable du sol, en relation avec une selectivite rapidement decroissante du sol pour Cs. La difference entre ces resultats est donc expliquee par une tres forte selectivite du sol illitique experimente pour Cs{sup +} tant que la proportion da cesium reste tres petite, de l'ordre de celle de la plupart des sols naturels

Innovation pour la santé des mères et des enfants d'Afrique | CRDI ...

International Development Research Centre (IDRC) Digital Library (Canada)

L'initiative Innovation pour la santé des mères et des enfants d'Afrique (ISMEA) cherche à améliorer la santé des mères, des nouveau-nés et des enfants en ... Cette initiative de 36 millions de dollars sur sept ans – financée conjointement par les Instituts de recherche en santé du Canada, Affaires mondiales Canada et le ...

Size distributions of aerosols produced from substitute materials by the Laskin cold DOP aerosol generator

International Nuclear Information System (INIS)

Hinds, W.; Macher, J.; First, M.W.

1981-01-01

Test aerosols of di(2-ethylhexyl)phthalate (DOP) produced by Laskin nozzle aerosol generators are widely used for in-place filter testing and respirator fit testing. Concern for the health effects of this material has led to a search for substitute materials for test aerosols. Aerosols were generated with a Laskin generator and diluted 6000-fold with clean air. Size distributions were measured for DOP, di(2-ethylhexyl)sebecate, polyethylene glycol, mineral oil, and corn oil aerosols with a PMS ASAS-X optical particle counter. Distributions were slightly bimodal with count median diameters from 0.22 to 0.30 μm. Size distributions varied little with aerosol material, operating pressure, or liquid level. Mineral oil and corn oil gave the best agreement with the DOP size distribution

Aerosol effects in radiation transfer

International Nuclear Information System (INIS)

Binenko, V.I.; Harshvardhan, H.

1993-01-01

The radiative properties and effects of aerosols are assessed for the following aerosol sources: relatively clean background aerosol, dust storms and dust outbreaks, anthropogenic pollution, and polluted cloud layers. Studies show it is the submicron aerosol fraction that plays a dominant radiative role in the atmosphere. The radiative effect of the aerosol depends not only on its loading but also on the underlying surface albedo and on solar zenith angle. It is only with highly reflecting surfaces such as Arctic ice that aerosols have a warming effect. Radiometric, microphysical, mineral composition, and refractive index measurements are presented for dust and in particular for the Saharan aerosol layer (SAL). Short-wave radiative heating of the atmosphere is caused by the SAL and is due mainly to absorption. However, the SAL does not contribute significantly to the long-wave thermal radiation budget. Field program studies of the radiative effects of aerosols are described. Anthropogenic aerosols deplete the incoming solar radiation. A case field study for a regional Ukrainian center is discussed. The urban aerosol causes a cooling of metropolitan centers, compared with outlying areas, during the day, which is followed by a warming trend at night. In another study, an increase in turbidity by a factor of 3 due to increased industrialization for Mexico City is noted, together with a drop in atmospheric transmission by 10% over a 50-year period. Numerous studies are cited that demonstrate that anthropogenic aerosols affect both the microphysical and radiative properties of clouds, which in turn affect regional climate. Particles acting as cloud nuclei are considered to have the greatest indirect effect on cloud absorptivity of short-wave radiation. Satellite observations show that low-level stratus clouds contaminated by ship exhaust at sea lead to an increase in cloud albedo

Aged organic aerosol in the Eastern Mediterranean: the Finokalia Aerosol Measurement Experiment – 2008

Directory of Open Access Journals (Sweden)

L. Hildebrandt

2010-05-01

Full Text Available Aged organic aerosol (OA was measured at a remote coastal site on the island of Crete, Greece during the Finokalia Aerosol Measurement Experiment-2008 (FAME-2008, which was part of the EUCAARI intensive campaign of May 2008. The site at Finokalia is influenced by air masses from different source regions, including long-range transport of pollution from continental Europe. A quadrupole aerosol mass spectrometer (Q-AMS was employed to measure the size-resolved chemical composition of non-refractory submicron aerosol (NR-PM₁, and to estimate the extent of oxidation of the organic aerosol. Factor analysis was used to gain insights into the processes and sources affecting the OA composition. The particles were internally mixed and liquid. The largest fraction of the dry NR-PM₁ sampled was ammonium sulfate and ammonium bisulfate, followed by organics and a small amount of nitrate. The variability in OA composition could be explained with two factors of oxygenated organic aerosol (OOA with differing extents of oxidation but similar volatility. Hydrocarbon-like organic aerosol (HOA was not detected. There was no statistically significant diurnal variation in the bulk composition of NR-PM₁ such as total sulfate or total organic aerosol concentrations. However, the OA composition exhibited statistically significant diurnal variation with more oxidized OA in the afternoon. The organic aerosol was highly oxidized, regardless of the source region. Total OA concentrations also varied little with source region, suggesting that local sources had only a small effect on OA concentrations measured at Finokalia. The aerosol was transported for about one day before arriving at the site, corresponding to an OH exposure of approximately 4×10¹¹ molecules cm⁻³ s. The constant extent of oxidation suggests that atmospheric aging results in a highly oxidized OA at these OH exposures, regardless of the aerosol source.

Analyse des caractéristiques structurelles et des performances ...

African Journals Online (AJOL)

SARAH

28 févr. 2014 ... performances technico-économiques de la riziculture irriguée en Côte d' .... en nous basant sur les prix des intrants et des produits en vigueur au cours ..... la recherche et de la vulgarisation et le transfert de technologies ; (2) ...

Enquête de satisfaction des restaurants

CERN Multimedia

Staff Association

2016-01-01

Comité de surveillance des restaurants L’Association du personnel est représentée dans plusieurs comités dont le Comité de surveillance des restaurants (CSR) qui a pour mandat : de donner son avis sur toute question relative à la politique générale de l’Organisation en matière de restauration sur le site, y compris en ce qui concerne les termes et l’attribution des contrats d’exploitation des restaurants ; de définir dans le cadre des contrats d’exploitation des restaurants, les prestations correspondant aux besoins et, dans la mesure du possible, aux désirs du personnel ; de surveiller les prestations des restaurants, y compris en ce qui concerne la qualité et la préparation des produits ; de négocier avec les concessionnaires des restaurants au sujet des tarifs et de surveill...

Contraintes d'adoption des technologies de gestion de la fertilite des ...

African Journals Online (AJOL)

La baisse de fertilité des sols, l'une des principales contraintes du secteur agricole au Togo, sévit encore plus dans la riziculture irriguée où les terres sont exploitées chaque année sans jachère. Face à cette situation, diverses solutions comme les technologies de gestion de la fertilité des sols ont été proposées.

contraintes d'adoption des technologies de gestion de la fertilite des ...

African Journals Online (AJOL)

La baisse de fertilité des sols, l'une des principales contraintes du secteur agricole au Togo, sévit encore plus dans la riziculture irriguée où les terres sont exploitées chaque année sans jachère. Face à cette situation, diverses solutions comme les technologies de gestion de la fertilité des sols ont été proposées.

Droit des organisations internationales

CERN Document Server

Sorel, Jean-Marc; Ndior, Valère

2013-01-01

Cet ouvrage collectif offre aux enseignants et chercheurs en droit international, aux praticiens et aux étudiants, une analyse actualisée du droit des organisations internationales. Il dresse en cinq parties un tableau, illustré par des exemples variés, des problématiques que soulève le phénomène polymorphe d institutionnalisation de la société internationale. La première partie est consacrée au phénomène des « organisations internationales », sous l angle à la fois de l institutionnalisation progressive des relations internationales et de la difficulté à cerner une catégorie unifiée. La deuxième partie rend compte de la création, de la disparition et des mutations des organisations internationales, ici envisagées comme systèmes institutionnels et ordres juridiques dérivés. La troisième partie analyse l autonomie que l acquisition de la personnalité juridique et de privilèges et immunités, un organe administratif intégré, un personnel ou un budget propres confèrent aux organi...

DETERMINATION EXPERIMENTALE DU COEFFICIENT DE DISPERSION D’UNE MATRICE DE SOL

Directory of Open Access Journals (Sweden)

R MAOUI

2005-06-01

Full Text Available La caractérisation des interactions entre une espèce chimique et une matrice de sol est généralement considérée dans les études des phénomènes de transport. Ce type de réaction est assujetti à l’estimation du coefficient de dispersion D. Ce coefficient représente le gradient de concentration de l’élément et le flux de transport ; il dépend de la distribution de la vitesse, de la porosité du milieu et des courants du liquide. Le présent travail décrit le procédé expérimental et la technique associée utilisés en vue de quantifier le coefficient D de deux traceurs radioactifs. Les résultats obtenus à l’échelle du laboratoire sont très satisfaisants et restent en conformité avec les résultats publiés

De la problématique des articles synopsis dans la compilation des ...

African Journals Online (AJOL)

Autrement dit, au Gabon l'attention doit porter sur l'utilisation des articles synopsis dans la compilation des dictionnaires, en vue de refléter dans ses ouvrages la diversité linguistique et culturelle de ce pays. Ceci est d'autant plus vrai que l'utilisation des articles synopsis ne dépend aucunement de la typologie du ...

Production of Highly Charged Pharmaceutical Aerosols Using a New Aerosol Induction Charger.

Science.gov (United States)

Golshahi, Laleh; Longest, P Worth; Holbrook, Landon; Snead, Jessica; Hindle, Michael

2015-09-01

Properly charged particles can be used for effective lung targeting of pharmaceutical aerosols. The objective of this study was to characterize the performance of a new induction charger that operates with a mesh nebulizer for the production of highly charged submicrometer aerosols to bypass the mouth-throat and deliver clinically relevant doses of medications to the lungs. Variables of interest included combinations of model drug (albuterol sulfate) and charging excipient (NaCl) as well as strength of the charging field (1-5 kV/cm). Aerosol charge and size were measured using a modified electrical low pressure impactor system combined with high performance liquid chromatography. At the approximate mass median aerodynamic diameter (MMAD) of the aerosol (~0.4 μm), the induction charge on the particles was an order of magnitude above the field and diffusion charge limit. The nebulization rate was 439.3 ± 42.9 μl/min, which with a 0.1% w/v solution delivered 419.5 ± 34.2 μg of medication per minute. A new correlation was developed to predict particle charge produced by the induction charger. The combination of the aerosol induction charger and predictive correlations will allow for the practical generation and control of charged submicrometer aerosols for targeting deposition within the lungs.

Evaluation des pratiques de gestion des adventices en riziculture

African Journals Online (AJOL)

Les résultats ont montré que les méthodes de gestion de l'enherbement ont .... Le contrôle des adventices en riziculture irriguée a principalement .... mesurer la hauteur des plantes et la longueur ..... Performance agronomique du Sys- tème de ...

Retrieving aerosol in a cloudy environment: aerosol product availability as a function of spatial resolution

Directory of Open Access Journals (Sweden)

L. A. Remer

2012-07-01

Full Text Available The challenge of using satellite observations to retrieve aerosol properties in a cloudy environment is to prevent contamination of the aerosol signal from clouds, while maintaining sufficient aerosol product yield to satisfy specific applications. We investigate aerosol retrieval availability at different instrument pixel resolutions using the standard MODIS aerosol cloud mask applied to MODIS data and supplemented with a new GOES-R cloud mask applied to GOES data for a domain covering North America and surrounding oceans. Aerosol product availability is not the same as the cloud free fraction and takes into account the techniques used in the MODIS algorithm to avoid clouds, reduce noise and maintain sufficient numbers of aerosol retrievals. The inherent spatial resolution of each instrument, 0.5×0.5 km for MODIS and 1×1 km for GOES, is systematically degraded to 1×1, 2×2, 1×4, 4×4 and 8×8 km resolutions and then analyzed as to how that degradation would affect the availability of an aerosol retrieval, assuming an aerosol product resolution at 8×8 km. The analysis is repeated, separately, for near-nadir pixels and those at larger view angles to investigate the effect of pixel growth at oblique angles on aerosol retrieval availability. The results show that as nominal pixel size increases, availability decreases until at 8×8 km 70% to 85% of the retrievals available at 0.5 km, nadir, have been lost. The effect at oblique angles is to further decrease availability over land but increase availability over ocean, because sun glint is found at near-nadir view angles. Finer resolution sensors (i.e., 1×1, 2×2 or even 1×4 km will retrieve aerosols in partly cloudy scenes significantly more often than sensors with nadir views of 4×4 km or coarser. Large differences in the results of the two cloud masks designed for MODIS aerosol and GOES cloud products strongly reinforce that cloud masks must be developed with specific purposes in mind and

Radiative Importance of Aerosol-Cloud Interaction

Science.gov (United States)

Tsay, Si-Chee

1999-01-01

Aerosol particles are input into the troposphere by biomass burning, among other sources. These aerosol palls cover large expanses of the earth's surface. Aerosols may directly scatter solar radiation back to space, thus increasing the earth's albedo and act to cool the earth's surface and atmosphere. Aerosols also contribute to the earth's energy balance indirectly. Hygroscopic aerosol act as cloud condensation nuclei (CCN) and thus affects cloud properties. In 1977, Twomey theorized that additional available CCN would create smaller but more numerous cloud droplets in a cloud with a given amount of liquid water. This in turn would increase the cloud albedo which would scatter additional radiation back to space and create a similar cooling pattern as the direct aerosol effect. Estimates of the magnitude of the aerosol indirect effect on a global scale range from 0.0 to -4.8 W/sq m. Thus the indirect effect can be of comparable magnitude and opposite in sign to the estimates of global greenhouse gas forcing Aerosol-cloud interaction is not a one-way process. Just as aerosols have an influence on clouds through the cloud microphysics, clouds have an influence on aerosols. Cloud droplets are solutions of liquid water and CCN, now dissolved. When the cloud droplet evaporates it leaves behind an aerosol particle. This new particle does not have to have the same properties as the original CCN. In fact, studies show that aerosol particles that result from cloud processing are larger in size than the original CCN. Optical properties of aerosol particles are dependent on the size of the particles. Larger particles have a smaller backscattering fraction, and thus less incoming solar radiation will be backscattered to space if the aerosol particles are larger. Therefore, we see that aerosols and clouds modify each other to influence the radiative balance of the earth. Understanding and quantifying the spatial and seasonal patterns of the aerosol indirect forcing may have

Contrôle des Circuits Auxiliaires des P.F.W. (arrêt machine 2003/2004)

CERN Document Server

Ottaviani, J

2004-01-01

Les PFW sont des nappes polaires installées sur les pôles des aimants du PS. Elles sont au nombre de 4 par unité d'aimant et constituées d'un circuit principal (dans lequel circule le courant désiré selon le cycle magnétique utilisé) et des circuits auxiliaires. Les circuits auxiliaires sont des enroulements de correction (boucles de tour et "pick-up" brasés sur les enroulements principaux). Pendant la variation du champ magnétique del'aimant PS, on utilise des tensions induites dans ces circuits auxiliaires pour corriger les erreurs de champ dues aux pertes par courants de Foucault dans la chambre à vide. Chaque année, pendant l'arrêt machine, on vérifie si les caractéristiques des circuits auxiliaires correspondent aux normes (mesures de résistances des boucles de tours, résistances entre "pick-up" et isolation des circuits) afin de faire un suivi. Les 404 PFW sont ainsi vérifiées. Dans cette note, on ne relèvera que les PFW ayant des défauts (valeurs hors tolérances, boucles ouvertes ...

Unveiling aerosol-cloud interactions - Part 1: Cloud contamination in satellite products enhances the aerosol indirect forcing estimate

Science.gov (United States)

Christensen, Matthew W.; Neubauer, David; Poulsen, Caroline A.; Thomas, Gareth E.; McGarragh, Gregory R.; Povey, Adam C.; Proud, Simon R.; Grainger, Roy G.

2017-11-01

Increased concentrations of aerosol can enhance the albedo of warm low-level cloud. Accurately quantifying this relationship from space is challenging due in part to contamination of aerosol statistics near clouds. Aerosol retrievals near clouds can be influenced by stray cloud particles in areas assumed to be cloud-free, particle swelling by humidification, shadows and enhanced scattering into the aerosol field from (3-D radiative transfer) clouds. To screen for this contamination we have developed a new cloud-aerosol pairing algorithm (CAPA) to link cloud observations to the nearest aerosol retrieval within the satellite image. The distance between each aerosol retrieval and nearest cloud is also computed in CAPA. Results from two independent satellite imagers, the Advanced Along-Track Scanning Radiometer (AATSR) and Moderate Resolution Imaging Spectroradiometer (MODIS), show a marked reduction in the strength of the intrinsic aerosol indirect radiative forcing when selecting aerosol pairs that are located farther away from the clouds (-0.28±0.26 W m-2) compared to those including pairs that are within 15 km of the nearest cloud (-0.49±0.18 W m-2). The larger aerosol optical depths in closer proximity to cloud artificially enhance the relationship between aerosol-loading, cloud albedo, and cloud fraction. These results suggest that previous satellite-based radiative forcing estimates represented in key climate reports may be exaggerated due to the inclusion of retrieval artefacts in the aerosol located near clouds.

Devices and methods for generating an aerosol

KAUST Repository

Bisetti, Fabrizio

2016-03-03

Aerosol generators and methods of generating aerosols are provided. The aerosol can be generated at a stagnation interface between a hot, wet stream and a cold, dry stream. The aerosol has the benefit that the properties of the aerosol can be precisely controlled. The stagnation interface can be generated, for example, by the opposed flow of the hot stream and the cold stream. The aerosol generator and the aerosol generation methods are capable of producing aerosols with precise particle sizes and a narrow size distribution. The properties of the aerosol can be controlled by controlling one or more of the stream temperatures, the saturation level of the hot stream, and the flow times of the streams.

Performances des équipements utilisés en liaison froide en liaison froide en restauration hospitalière - Suivi des températures des entrées froides

OpenAIRE

Rosset , Philippe; Morelli , Elisabeth; Noël , Véronique; Poumeyrol , Gérard

2007-01-01

La restauration hospitalière présente un système de distribution des repas qui lui est spécifique : assemblage des denrées préparées et constitution des plateaux-repas dans un local dédié (dit d'allotissement) ; transport des plateaux-repas vers les unités de soins dans des enceintes mobiles permettant le maintien au froid des denrées consommées froides et la remise en température des aliments à consommer chauds. La présente étude concerne le suivi des températures de hors-d'œuvre dans trois ...

The GRAPE aerosol retrieval algorithm

Directory of Open Access Journals (Sweden)

G. E. Thomas

2009-11-01

Full Text Available The aerosol component of the Oxford-Rutherford Aerosol and Cloud (ORAC combined cloud and aerosol retrieval scheme is described and the theoretical performance of the algorithm is analysed. ORAC is an optimal estimation retrieval scheme for deriving cloud and aerosol properties from measurements made by imaging satellite radiometers and, when applied to cloud free radiances, provides estimates of aerosol optical depth at a wavelength of 550 nm, aerosol effective radius and surface reflectance at 550 nm. The aerosol retrieval component of ORAC has several incarnations – this paper addresses the version which operates in conjunction with the cloud retrieval component of ORAC (described by Watts et al., 1998, as applied in producing the Global Retrieval of ATSR Cloud Parameters and Evaluation (GRAPE data-set.

The algorithm is described in detail and its performance examined. This includes a discussion of errors resulting from the formulation of the forward model, sensitivity of the retrieval to the measurements and a priori constraints, and errors resulting from assumptions made about the atmospheric/surface state.

Aerosol in the containment

International Nuclear Information System (INIS)

Lanza, S.; Mariotti, P.

1986-01-01

The US program LACE (LWR Aerosol Containment Experiments), in which Italy participates together with several European countries, Canada and Japan, aims at evaluating by means of a large scale experimental activity at HEDL the retention in the pipings and primary container of the radioactive aerosol released following severe accidents in light water reactors. At the same time these experiences will make available data through which the codes used to analyse the behaviour of the aerosol in the containment and to verify whether by means of the codes of thermohydraulic computation it is possible to evaluate with sufficient accuracy variable influencing the aerosol behaviour, can be validated. This report shows and compares the results obtained by the participants in the LACE program with the aerosol containment codes NAVA 5 and CONTAIN for the pre-test computations of the test LA 1, in which an accident called containment by pass is simulated

CATS Aerosol Typing and Future Directions

Science.gov (United States)

McGill, Matt; Yorks, John; Scott, Stan; Palm, Stephen; Hlavka, Dennis; Hart, William; Nowottnick, Ed; Selmer, Patrick; Kupchock, Andrew; Midzak, Natalie;

Stratospheric Aerosol Measurements

Science.gov (United States)

Pueschel, Rudolf, F.; Gore, Warren J. (Technical Monitor)

1998-01-01

Stratospheric aerosols affect the atmospheric energy balance by scattering and absorbing solar and terrestrial radiation. They also can alter stratospheric chemical cycles by catalyzing heterogeneous reactions which markedly perturb odd nitrogen, chlorine and ozone levels. Aerosol measurements by satellites began in NASA in 1975 with the Stratospheric Aerosol Measurement (SAM) program, to be followed by the Stratospheric Aerosol and Gas Experiment (SAGE) starting in 1979. Both programs employ the solar occultation, or Earth limb extinction, techniques. Major results of these activities include the discovery of polar stratospheric clouds (PSCs) in both hemispheres in winter, illustrations of the impacts of major (El Chichon 1982 and Pinatubo 1991) eruptions, and detection of a negative global trend in lower stratospheric/upper tropospheric aerosol extinction. This latter result can be considered a triumph of successful worldwide sulfur emission controls. The SAGE record will be continued and improved by SAGE III, currently scheduled for multiple launches beginning in 2000 as part of the Earth Observing System (EOS). The satellite program has been supplemented by in situ measurements aboard the ER-2 (20 km ceiling) since 1974, and from the DC-8 (13 km ceiling) aircraft beginning in 1989. Collection by wire impactors and subsequent electron microscopic and X-ray energy-dispersive analyses, and optical particle spectrometry have been the principle techniques. Major findings are: (1) The stratospheric background aerosol consists of dilute sulfuric acid droplets of around 0.1 micrometer modal diameter at concentration of tens to hundreds of monograms per cubic meter; (2) Soot from aircraft amounts to a fraction of one percent of the background total aerosol; (3) Volcanic eruptions perturb the sulfuric acid, but not the soot, aerosol abundance by several orders of magnitude; (4) PSCs contain nitric acid at temperatures below 195K, supporting chemical hypotheses

Radioactive aerosols. [In Russian

Energy Technology Data Exchange (ETDEWEB)

Natanson, G L

1956-01-01

Tabulations are given presenting various published data on safe atmospheric concentrations of various radioactive and non-radioactive aerosols. Methods of determination of active aerosol concentrations and dispersion as well as the technical applications of labeled aerosols are discussed. The effect of atomic explosions are analyzed considering the nominal atomic bomb based on /sup 235/U and /sup 232/Pu equivalent to 20,000 tons of TNT.

Vers une meilleure comprehension des savoirs disciplinaires et curriculaires des enseignants ou Ie paradigme retrouve

Directory of Open Access Journals (Sweden)

Stephane Martineau

1999-01-01

Full Text Available eet article se veut essentieUement un travail de synthese sous la forme d 'une breve revue de litterature au sujet des savoirs disciplinaires et curriculaires en enseignement. Plus specifiquement, il vise a determiner queUes sont les principales conclusions qui se degagent de la lecture des recherches empiriques sur les savoirs disciplinaires et curriculaires des enseignants des ordres d'enseignement primaire et secondaire. Il propose donc une classification des differentes dimensions constitutives du rapport entre les savoirs disciplinaires et curriculaires et la pratique enseignante. Les resultats mis au jour permettent d 'une part, d'identifier les facteurs qui entrainent des differences dans les connaissances disciplinaires et curriculaires des enseignants et d'autre part, de mieux saisir comment ces connaissances de l'enseignant peuvent influencer en retour sa pratique.

Contrôle hormonal des caractéristiques des fibres musculaires après la naissance

OpenAIRE

Cassar-Malek, Isabelle; Listrat, Anne; Picard, Brigitte

1998-01-01

Après la naissance, la croissance et les propriétés contractiles et métaboliques des fibres musculaires sont soumises à une régulation endocrinienne complexe. A l’exception des glucocorticoïdes, la plupart des hormones présente une action anabolique sur le tissu musculaire. Leur influence sur les caractéristiques des fibres est cependant très différente. Ainsi, les hormones somatotropes affectent peu la composition en fibres des muscles. La GH, comme l’IGF-1, régulerait cependant l’expression...

Devices and methods for generating an aerosol

KAUST Repository

Bisetti, Fabrizio; Scribano, Gianfranco

2016-01-01

Aerosol generators and methods of generating aerosols are provided. The aerosol can be generated at a stagnation interface between a hot, wet stream and a cold, dry stream. The aerosol has the benefit that the properties of the aerosol can

Modélisation des propriétés diélectriques des nanocomposites ...

African Journals Online (AJOL)

Dans ce travail, nous nous intéressons aux propriétés diélectriques dans le domaine des micro-ondes (2.45, 9.50 et 35 GHz) des composites constitués des inclusions de noir de carbone dans une matrice résine époxyde. Nous avons utilisé deux types de carbone : le monarch 700 et le sterling, dont les diamètres des ...

Civili, langue des Baloango

DEFF Research Database (Denmark)

Mavoungou, Paul Achille; Ndinga-Koumba-Binza, Hugues Steve

, Congo, Angola, etc.) issus de la décolonisation. Il présente de façon succincte quelques phénomènes historiques, phonologiques, morphosyntaxiques, homonymiques et analogiques de la langue. Des faits sémantiques des emprunts linguistiques y sont également décrits dans le cadre des changements...

An aerosole generator for production of radioactive aerosoles by evaporating uranium dioxide

International Nuclear Information System (INIS)

Pusch, W.M.

1975-01-01

In the Institut for Biology of the Austrian Research Center at Seibersdorf an experiment is running to study the behaviour of radioactive aerosoles in the organism of miniature swines after inhalation. In the work under discussion the aerosole generator of the equipment used for this inhalation experiments is described by means of which the aerosole-air mixtures are produced. The main part of this generator is a gas burner for evaporating irradiated UO 2 -pellets. (orig.) [de

A study of the attachment of thoron decay products to aerosols using an aerosol centrifuge

International Nuclear Information System (INIS)

Menon, V.B.; Kotrappa, P.; Bhanti, D.P.

1980-01-01

An aerosol centrifuge is used for the study of the attachment of thoron decay products to aerosol particles under dynamic flow conditions. The number concentration of aerosols was kept high (10 5 to 10 6 particles cm -3 ) as compared to the number of decay product atoms (10 2 to 10 3 cm -3 ) as is usually the case in a mine atmosphere. The polydispersed aerosols flow in and out of a chamber containing a steady source of thoron and the aerosols tagged with the decay products were separated into different size groups by an aerosol centrifuge (Lovelace Aerosol Particle Separator). The average activity per particle was fitted as a power function of the radius in the form of Asub(p) = aRsup(b). The average value of b was found to be 1.08 +- 0.054 for particles in the radii range 0.25 to 1.35 μm and 1.34 +- 0.12 for particles in the radii range 0.1 to 0.33 μm. (author)

Modification of Local Urban Aerosol Properties by Long-Range Transport of Biomass Burning Aerosol

Directory of Open Access Journals (Sweden)

Iwona S. Stachlewska

2018-03-01

Full Text Available During August 2016, a quasi-stationary high-pressure system spreading over Central and North-Eastern Europe, caused weather conditions that allowed for 24/7 observations of aerosol optical properties by using a complex multi-wavelength PollyXT lidar system with Raman, polarization and water vapour capabilities, based at the European Aerosol Research Lidar Network (EARLINET network urban site in Warsaw, Poland. During 24–30 August 2016, the lidar-derived products (boundary layer height, aerosol optical depth, Ångström exponent, lidar ratio, depolarization ratio were analysed in terms of air mass transport (HYSPLIT model, aerosol load (CAMS data and type (NAAPS model and confronted with active and passive remote sensing at the ground level (PolandAOD, AERONET, WIOS-AQ networks and aboard satellites (SEVIRI, MODIS, CATS sensors. Optical properties for less than a day-old fresh biomass burning aerosol, advected into Warsaw’s boundary layer from over Ukraine, were compared with the properties of long-range transported 3–5 day-old aged biomass burning aerosol detected in the free troposphere over Warsaw. Analyses of temporal changes of aerosol properties within the boundary layer, revealed an increase of aerosol optical depth and Ångström exponent accompanied by an increase of surface PM10 and PM2.5. Intrusions of advected biomass burning particles into the urban boundary layer seem to affect not only the optical properties observed but also the top height of the boundary layer, by moderating its increase.

Comment constituer et traiter des corpus issus des médias sociaux à l’aide des CAQDAS? NVivo : un instrument pour l’analyse des discours numériques

Directory of Open Access Journals (Sweden)

Ferrari Giovannipaolo

2015-01-01

Full Text Available Avec l’apparition des médias sociaux, le chercheur en Sciences Humaines et Sociales a vu s’ouvrir des possibilités de création de corpus à partir des données disponibles en ligne. Le risque dans ces modalités de création de corpus est de créer de grandes bases de données difficilement gérables avec les outils traditionnels et surtout dans le cadre d’une recherche qualitative. Pour cette raison, il semble important de mobiliser des outils numériques pour l’aide à la recherche. Ces logiciels sont appelés CAQDAS. Cette contribution montre comment les utiliser pour une enquête de terrain en ligne ou numérique afin d’organiser et d’analyser un corpus. Ce corpus est constitué en vue d’une analyse des discours produits dans le contexte professionnel de la radio utilisant les nouveaux médias.

Study of the Fixation and Migration of Radioactive Cations in a Natural Ion Exchanger; Etude de la Fixation et de la Migration de Cations Radioactifs dans un Echangeur d'Ions Naturel; 0418 0417 0423 0427 0415 0414 ; Estudio de la Fijacion y de la Migracion de Cationes Radiactivos en un Cambiador Natural de Iones

Energy Technology Data Exchange (ETDEWEB)

Baetsle, L. [Centre d' Etudes de l' Energie Nucleaire, Mol (Belgium)

1960-07-01

With a view to utilizing lignite as a natural ion exchanger in the treatment of radioactive waste, a study was made of its physical and physico-chemical properties with reference to ion exchange. The distribution of Sr{sup 90} and Cs{sup 137} ions in the presence of Ca, Na and H was first examined and the equilibrium constants calculated. The kinetics and fixation of ions were then studied, and various parameters required for the calculation of ion-exchange beds were established. Study of the complex phenomenon of radioactive ion migration in the soil was started by the separate investigation of each component ionic equilibrium. (author) [French] Afin d'utiliser le lignite comme echangeur d'ions naturel dans le traitement d'eaux residuaires radioactives, uene etude a ete faite de ses proprietes physiques et physiochimiques, ayant trait a l'echange d'ions. En premier lieu on a etudie la distribution des ions {sup 90}Sr et {sup 137}Cs en presence de Ca, Na et H, et calcule les constantes d'equilibre. En second heu on a traite la cinetique de la fixation des ions, et etabli quelques parametres necessaires au calcul de hts d'echangeurs d'ions. L'etude du phenomene complexe de la migration des ions radioactifs dans le sol a ete abordee par l 'investigation separee de chacun des equilibres ioniques composants. (author) [Spanish] Con objeto de utilizar el lignito como cambiador natural de iones en el tratamiento de aguas residuales radiactivas, se han estudiado sus propiedades fisicas y fisicoquimicas en relacion con el intercambio de iones. En primer lugar, el autor ha estudiado la distribucion de los iones {sup 90}Sr y {sup 137}Cs en presencia de Ca, Na y H, y ha calculado las constantes de equilibrio. En segundo lugar ha estudiado la cinetica de la fijacion de iones y ha establecido algunos parametros necesarios para calcular los lechos de cambiadores de iones. El autor ha abordado el estudio del complejo fenomeno de la migracion de iones radiactivos en el suelo

Ethnobotanique des plantes médicinales anti hémorroïdaires des ...

African Journals Online (AJOL)

SARAH

2015-12-31

Dec 31, 2015 ... but est de valoriser la médecine à base des plantes dans le traitement des pathologies ... médicinales anti hémorroïdaires et le coût réduit des recettes serait pour les populations démunies, ...... l'Afrique, Unesco/Aetfat/Unso.

Aerosol characterization during project POLINAT

Energy Technology Data Exchange (ETDEWEB)

Hagen, D.E.; Hopkins, A.R.; Paladino, J.D.; Whitefield, P.D. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Aerospace-East, St. Louis, MO (United States)

1997-12-31

The objectives of the aerosol/particulate characterization measurements of project POLINAT (POLlution from aircraft emissions In the North ATlantic flight corridor) are: to search for aerosol/particulate signatures of air traffic emissions in the region of the North Atlantic Flight Corridor; to search for the aerosol/particulate component of large scale enhancement (`corridor effects`) of air traffic related species in the North Atlantic region; to determine the effective emission indices for the aerosol/particulate component of engine exhaust in both the near and far field of aircraft exhaust plumes; to measure the dispersion and transformation of the aerosol/particulate component of aircraft emissions as a function of ambient condition; to characterize background levels of aerosol/particulate concentrations in the North Atlantic Region; and to determine effective emission indices for engine exhaust particulates for regimes beyond the jet phase of plume expansion. (author) 10 refs.

Aerosol characterization during project POLINAT

Energy Technology Data Exchange (ETDEWEB)

Hagen, D E; Hopkins, A R; Paladino, J D; Whitefield, P D [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H V [McDonnell Douglas Aerospace-East, St. Louis, MO (United States)

1998-12-31

The objectives of the aerosol/particulate characterization measurements of project POLINAT (POLlution from aircraft emissions In the North ATlantic flight corridor) are: to search for aerosol/particulate signatures of air traffic emissions in the region of the North Atlantic Flight Corridor; to search for the aerosol/particulate component of large scale enhancement (`corridor effects`) of air traffic related species in the North Atlantic region; to determine the effective emission indices for the aerosol/particulate component of engine exhaust in both the near and far field of aircraft exhaust plumes; to measure the dispersion and transformation of the aerosol/particulate component of aircraft emissions as a function of ambient condition; to characterize background levels of aerosol/particulate concentrations in the North Atlantic Region; and to determine effective emission indices for engine exhaust particulates for regimes beyond the jet phase of plume expansion. (author) 10 refs.

The effects of aerosols on climate

International Nuclear Information System (INIS)

Boucher, O.

1997-01-01

Atmospheric aerosols (fine particles suspended in the atmosphere) can play two roles in the Earth’s radiation budget. In cloud-free air, aerosols scatter sunlight, some of which is reflected back to space (direct effect). Aerosols also determine the microphysical and optical properties of clouds (indirect effect). Whereas changes in natural aerosols are probably small during the last 100 years, there has been a large increase in the concentration of anthropogenic aerosols. The magnitude of their radiative effects is still very uncertain but seems to be sufficient to mask part of the global warming expected to stem from anthropogenic greenhouse gases. This paper presents the physical mechanisms of aerosol influence on climate. We then estimate the anthropogenic aerosol radiative effects and assess the climate response to these perturbations. (author) [fr

Table des illustrations

OpenAIRE

2016-01-01

Tableaux Dates d’inauguration des grands hôtels japonais entre 1860 et 1945… 19 Histoire, tourisme et hôtellerie en Corée depuis les années 1870… 59-60 Dates d’inauguration des grands hôtels chinois depuis 1863… 84 Les hôtels de luxe et leurs capacités d’hébergement en Corée en 2000… 103 Les flux de personnes suscités par les hôtels « super luxe » de Séoul en 2000… 105 L’activité des grands hôtels à Séoul en 1999 (en wons)… 106 Propriété et gestion des grands hôtels à Séoul en 1999…. 110 La c...

La recherche en action : des solutions locales, des effets durables ...

International Development Research Centre (IDRC) Digital Library (Canada)

15 déc. 2010 ... Le Centre de recherches pour le développement international (CRDI) appuie la production et l'application de connaissances qui améliorent de façon notable la situation des habitants des pays en développement.

Water content of aged aerosol

Directory of Open Access Journals (Sweden)

G. J. Engelhart

2011-02-01

Full Text Available The composition and physical properties of aged atmospheric aerosol were characterized at a remote sampling site on the northern coast of Crete, Greece during the Finokalia Aerosol Measurement Experiment in May 2008 (FAME-2008. A reduced Dry-Ambient Aerosol Size Spectrometer (DAASS was deployed to measure the aerosol water content and volumetric growth factor of fine particulate matter. The particles remained wet even at relative humidity (RH as low as 20%. The aerosol was acidic during most of the measurement campaign, which likely contributed to the water uptake at low RH. The water content observations were compared to the thermodynamic model E-AIM, neglecting any contribution of the organics to aerosol water content. There was good agreement between the water measurements and the model predictions. Adding the small amount of water associated with the organic aerosol based on monoterpene water absorption did not change the quality of the agreement. These results strongly suggest that the water uptake by aged organic aerosol is relatively small (a few percent of the total water for the conditions during FAME-08 and generally consistent with what has been observed in laboratory experiments. The water concentration measured by a Q-AMS was well correlated with the DAASS measurements and in good agreement with the predicted values for the RH of the Q-AMS inlet. This suggests that, at least for the conditions of the study, the Q-AMS can provide valuable information about the aerosol water concentrations if the sample is not dried.

La revolution des savants

CERN Document Server

Chavanne, A

1989-01-01

Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

Diversification des moyens de subsistance des petits producteurs de ...

International Development Research Centre (IDRC) Digital Library (Canada)

L'économie du Malawi repose essentiellement sur la culture du tabac, qui représente plus de 70 % des revenus d'exportation. Pour 60 % des 100 000 membres de la National Smallholder Farmers' Association of Malawi (NASFAM), le tabac est la seule et unique source de revenus. Les cultivateurs de tabac, au Malawi ...

À l’aube des dieux

Directory of Open Access Journals (Sweden)

Pascal Semonsut

2011-03-01

Full Text Available De l’avis même des préhistoriens, la Préhistoire assiste à la naissance du sentiment religieux. Cette religion des origines, quelle image en ont les Français ? Telle est la question que cet article aborde à partir de l’étude des manuels scolaires et des œuvres de fiction (littérature, cinéma et bande dessinée de la seconde moitié du XXe siècle. Si l’enseignement et la fiction n’accordent pas la même place à ce thème, en revanche tous deux font des préhistoriques des polythéistes adorant le soleil, construisant des mégalithes et prenant le plus grand soin de leurs morts. Ce mélange d’obscurantisme et de vraie spiritualité n’a qu’un but : montrer que notre espèce ne pouvait être que victorieuse dans ce combat qu’est l’humanisation.

AEROSOL VARIABILITY OBSERVED WITH RPAS

Directory of Open Access Journals (Sweden)

B. Altstädter

2013-08-01

Full Text Available To observe the origin, vertical and horizontal distribution and variability of aerosol particles, and especially ultrafine particles recently formed, we plan to employ the remotely piloted aircraft system (RPAS Carolo-P360 "ALADINA" of TU Braunschweig. The goal of the presented project is to investigate the vertical and horizontal distribution, transport and small-scale variability of aerosol particles in the atmospheric boundary layer using RPAS. Two additional RPAS of type MASC of Tübingen University equipped with turbulence instrumentation add the opportunity to study the interaction of the aerosol concentration with turbulent transport and exchange processes of the surface and the atmosphere. The combination of different flight patterns of the three RPAS allows new insights in atmospheric boundary layer processes. Currently, the different aerosol sensors are miniaturized at the Leibniz Institute for Tropospheric Research, Leipzig and together with the TU Braunschweig adapted to fit into the RPAS. Moreover, an additional meteorological payload for measuring temperature, humidity and turbulence properties is constructed by Tübingen University. Two condensation particle counters determine the total aerosol number with a different lower detection threshold in order to investigate the horizontal and vertical aerosol variability and new particle formation (aerosol particles of some nm diameter. Further the aerosol size distribution in the range from about 0.300 to ~5 μm is given by an optical particle counter.

Aerosols from biomass combustion

Energy Technology Data Exchange (ETDEWEB)

Nussbaumer, T

2001-07-01

This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

Sodium aerosol recovering device

International Nuclear Information System (INIS)

Fujimori, Koji; Ueda, Mitsuo; Tanaka, Kazuhisa.

1997-01-01

A main body of a recovering device is disposed in a sodium cooled reactor or a sodium cooled test device. Air containing sodium aerosol is sucked into the main body of the recovering device by a recycling fan and introduced to a multi-staged metal mesh filter portion. The air about against each of the metal mesh filters, and the sodium aerosol in the air is collected. The air having a reduced sodium aerosol concentration circulates passing through a recycling fan and pipelines to form a circulation air streams. Sodium aerosol deposited on each of the metal mesh filters is scraped off periodically by a scraper driving device to prevent clogging of each of the metal filters. (I.N.)

Aerosols from biomass combustion

Energy Technology Data Exchange (ETDEWEB)

Nussbaumer, T.

2001-07-01

This report is the proceedings of a seminar on biomass combustion and aerosol production organised jointly by the International Energy Agency's (IEA) Task 32 on bio energy and the Swiss Federal Office of Energy (SFOE). This collection of 16 papers discusses the production of aerosols and fine particles by the burning of biomass and their effects. Expert knowledge on the environmental impact of aerosols, formation mechanisms, measurement technologies, methods of analysis and measures to be taken to reduce such emissions is presented. The seminar, visited by 50 participants from 11 countries, shows, according to the authors, that the reduction of aerosol emissions resulting from biomass combustion will remain a challenge for the future.

La maison des mathématiques

CERN Document Server

Villani, Cédric; Moncorgé, Vincent

2014-01-01

Comment travaillent les mathématiciens ? C'est peut-être en se promenant dans les couloirs de la première des " maisons des mathématiques " de France, l'institut Henri Poincaré, que l'on trouvera quelques réponses. Le mathématicien Cédric Villani et le physicien Jean-Philippe Uzan nous invitent à découvrir cette discipline et ses acteurs. Au fil des pages on suit, à travers de superbes images signées du photographe Vincent Moncorgé, la façon dont se fabrique cette science qui reste souvent mystérieuse. Toutes les dimensions, scientifique, esthétique et poétique, des mathématiques sont convoquées grâce à des regards croisés : la diversité des inspirations des chercheurs, la source de leur créativité, l'imaginaire littéraire et artistique des mathématiques, la drôle de tribu des mathématiciens. Un voyage au cœur de cette " auberge espagnole " des mathématiques, campus " à la française " accueillant des centaines de chercheurs du monde entier, devenu un lieu d'émulation et d'éc...

Global simulations of aerosol processing in clouds

Directory of Open Access Journals (Sweden)

C. Hoose

2008-12-01

Full Text Available An explicit and detailed representation of in-droplet and in-crystal aerosol particles in stratiform clouds has been introduced in the global aerosol-climate model ECHAM5-HAM. The new scheme allows an evaluation of the cloud cycling of aerosols and an estimation of the relative contributions of nucleation and collision scavenging, as opposed to evaporation of hydrometeors in the global aerosol processing by clouds. On average an aerosol particle is cycled through stratiform clouds 0.5 times. The new scheme leads to important changes in the simulated fraction of aerosol scavenged in clouds, and consequently in the aerosol wet deposition. In general, less aerosol is scavenged into clouds with the new prognostic treatment than what is prescribed in standard ECHAM5-HAM. Aerosol concentrations, size distributions, scavenged fractions and cloud droplet concentrations are evaluated and compared to different observations. While the scavenged fraction and the aerosol number concentrations in the marine boundary layer are well represented in the new model, aerosol optical thickness, cloud droplet number concentrations in the marine boundary layer and the aerosol volume in the accumulation and coarse modes over the oceans are overestimated. Sensitivity studies suggest that a better representation of below-cloud scavenging, higher in-cloud collision coefficients, or a reduced water uptake by seasalt aerosols could reduce these biases.

Treatment of Radioactive Effluents at the Saclay Nuclear Research Centre; Traitement des Effluents Radioactifs au Centre d'Etudes Nucleaires de Saclay; 041e 0414 ; Tratamiento de los Efluentes Radiactivos en el Centro de Energia Nuclear de Saclay

Energy Technology Data Exchange (ETDEWEB)

Wormser, G. [Service de Controle des Radiations et de Genie Radioactif, Commissariat a l' Energie Atomique, Saclay (France)

1960-07-01

The Report Gives The Account Of Four Years' Experience In Operating The Treatment Plant For Effluents From The Saclay Nuclear Research Centre. It Contains Data Relating To The Origin, Volume And Treatment Of Waste. (author) [French] Ce rapport presente un bilan d'exploitation de l'installation de traitement des effluents du Centre d'etudes nucleaires de Saclay depuis quatre ans. On donne des chiffres concernant l'origine des residus, leur volume, leur traitement. (author) [Spanish] El autor hace un balance de explotacion de la instalacion de tratamiento de efluentes del centro de Saclay desde hace cuatro anos, dando las cifras correspondientes al origen de los residuos, a su volumen y a su tratamiento. (author) [Russian] V jetom dokumente podvoditsja itog chetyrehletnej jekspluatacii ustanovki po obrabotke zhidkih othotov v Centre jadernyh issledovanij v Sakle. V doklade privodjatsja dannye o proishozhdenii othodov, jh ob'eme i obrabotke. (author)

Modernisation des marchés agroalimentaires - inclusion des petits ...

International Development Research Centre (IDRC) Digital Library (Canada)

Les marchés agroalimentaires connaissent de rapides changements dans les pays en développement et les pays en transition. Sous l'influence de la libéralisation du commerce et des nouvelles technologies de transformation des aliments et de commerce de détail, les marchés agroalimentaires évoluent vers une plus ...

Culture du bambou : diversification des moyens de subsistance des ...

International Development Research Centre (IDRC) Digital Library (Canada)

Culture du bambou : diversification des moyens de subsistance des petits producteurs de tabac du sud de la province de Nyanza, au Kenya - phase II. Au cours de la première phase du projet (projet no 103765), les chercheurs ont effectué une analyse de marché pour le bambou et les produits du bambou, comparé les ...

Structurations formelle et conceptuelle des articles de dictionnaires : le premier modèle de codification des articles dans l’histoire des dictionnaires Larousse

Directory of Open Access Journals (Sweden)

Corbin Pierre

2014-07-01

Nous nous proposons d’examiner, dans l’histoire des dictionnaires généraux monolingues Larousse des origines à nos jours, une sélection de jalons de l’articulation entre structure conceptuelle et structure formelle des articles. Au regard de l’ampleur des données à couvrir, il ne pourra bien entendu s’agir que d’un survol, mais celui-ci permettra (1 de présenter le premier des trois modèles majeurs de codification des articles dans l’histoire des dictionnaires Larousse, celui qui trouve son origine dans le Nouveau dictionnaire de la langue française de 1856 ou ses éditions révisées, (2 de prendre en compte les dictionnaires proposés par cet éditeur en un siècle et demi qui ont repris le modèle de 1856 ou sa forme révisée, et (3 de présenter contrastivement au premier les deux autres modèles majeurs, qui trouvent leur ancrage chronologique respectivement dans le Grand dictionnaire universel du XIXe siècle de 1866-1876 et le Dictionnaire du français contemporain de 1966.

Radioisotopes as tracers for reactions in molten fluoride media; Les radioisotopes comme indicateurs des reactions se produisant dans des milieux de fluorures fondus; Ispol'zovanie radioizotopov v kachestve indikatorov dlya reaktsij v rasplavlennoj ftoristoj srede; Los radioisotopos como indicadores de las reacciones que tienen lugar en un medio de fluoruros fundidos

Energy Technology Data Exchange (ETDEWEB)

Grimes, W R; Shaffer, J H; Strehlow, R A; Ward, W T; Watson, G M [Oak Ridge National Laboratory, Oak Ridge, TN (United States)

1962-03-15

ne produit un echange rapide entre l'indicateur radioactif LaF{sub 3} et le La{sub 2}O{sub 3} non actif. Dans le meme solvant, il se produit aussi un echange rapide entre l'indicateur radioactif CeF{sub 3} et le CeO{sub 2} non actif; le transfert d'electrons necessaire dans ce dernier cas ne fait apparemment pas obstacle a la reaction. L'addition de CeF{sub 3} non actif a chacun de ces systemes augmente la concentration de radioisotopes dans la solution, conformement a la loi d'action des masses. Lorsque l'on refroidit certains melanges fondus de LiF et BeF{sub 2} contenant du CeF{sub 3} et des fluorures de terres rares, la phase primaire est une solution solide des trifluorures. Des equilibres entre la solution fondue et la solution solide ont ete evalues pour diverses paires de fluorures. On n'a observe aucune derogation significative a la loi d'action de masse. Les auteurs du memoire ont reussi a separer diverses especes par precipitation selective des oxydos a partir de solutions de fluorures fondus. (author) [Spanish] Los autores han estudiado las reacciones quimicas que pueden contribuir a la eliminacion, de ciertos constituyentes disueltos en fluoruros fundidos. Para ello han empleado radioisotopos adecuados y tecnicas corrientes de recuento. Las reacciones estudiadas incluyen: 1) el intercambio isotopico entre indicadores disueltos y compuestos insolubles, 2) la particion del soluto entre la fase fundida y una solucion solida de un compuesto similar y 3) la precipitacion del radioisotopo como compuesto insoluble. Algunos experimentos tipicos revelan que en las muestras de LiF-NaF el LaF{sub 3} utilizado como indicador radiactivo se intercambia rapidamente con el La{sub 2}O3 inactivo. En el mismo disolvente se observa tambien intercambio rapido entre el CeF{sub 3} radiotrazador y CeO{sub 2} inactivo; aparentemente, la transferencia de electrones necesaria en este ultimo caso no impide la reaccion. La adicion de CeF{sub 3} inactivo a cada uno de los sistemas

The physico-chemical evolution of atmospheric aerosols and the gas-particle partitioning of inorganic aerosol during KORUS-AQ

Science.gov (United States)

Lee, T.; Park, T.; Lee, J. B.; Lim, Y. J.; Ahn, J.; Park, J. S.; Soo, C. J.; Desyaterik, Y.; Collett, J. L., Jr.

2017-12-01

Aerosols influence climate change directly by scattering and absorption and indirectly by acting as cloud condensation nuclei and some of the effects of aerosols are reduction in visibility, deterioration of human health, and deposition of pollutants to ecosystems. Urban area is large source of aerosols and aerosol precursors. Aerosol sources are both local and from long-range transport. Long-range transport processed aerosol are often dominant sources of aerosol pollution in Korea. To improve our knowledge of aerosol chemistry, Korea and U.S-Air Quality (KORUS-AQ) of Aircraft-based aerosol measurement took place in and around Seoul, Korea during May and June 2016. KORUS-AQ campaigns were conducted to study the chemical characterization and processes of pollutants in the Seoul Metropolitan area to regional scales of Korean peninsula. Aerodyne High Resolution Time of Flight Aerosol Mass Spectrometer (HR-ToF-AMS) was deployed on aircraft platforms on-board DC-8 (NASA) aircraft. We characterized aerosol chemical properties and mass concentrations of sulfate, nitrate, ammonium and organics in polluted air plumes and investigate the spatial and vertical distribution of the species. The results of studies show that organics is predominant in Aerosol and a significant fraction of the organics is oxygenated organic aerosol (OOA) at the high altitude. Both Nitrate and sulfate can partition between the gas and particle phases. The ratios for HNO3/(N(V) (=gaseous HNO3 + particulate Nitrate) and SO2/(SO2+Sulfate) were found to exhibit quite different distributions between the particles and gas phase for the locations during KORUS-AQ campaign, representing potential for formation of additional particulate nitrate and sulfate. The results of those studies can provide highly resolved temporal and spatial air pollutant, which are valuable for air quality model input parameters for aerosol behaviour.

MATRIX (Multiconfiguration Aerosol TRacker of mIXing state: an aerosol microphysical module for global atmospheric models

Directory of Open Access Journals (Sweden)

S. E. Bauer

2008-10-01

Full Text Available A new aerosol microphysical module MATRIX, the Multiconfiguration Aerosol TRacker of mIXing state, and its application in the Goddard Institute for Space Studies (GISS climate model (ModelE are described. This module, which is based on the quadrature method of moments (QMOM, represents nucleation, condensation, coagulation, internal and external mixing, and cloud-drop activation and provides aerosol particle mass and number concentration and particle size information for up to 16 mixed-mode aerosol populations. Internal and external mixing among aerosol components sulfate, nitrate, ammonium, carbonaceous aerosols, dust and sea-salt particles are represented. The solubility of each aerosol population, which is explicitly calculated based on its soluble and insoluble components, enables calculation of the dependence of cloud drop activation on the microphysical characterization of multiple soluble aerosol populations.

A detailed model description and results of box-model simulations of various aerosol population configurations are presented. The box model experiments demonstrate the dependence of cloud activating aerosol number concentration on the aerosol population configuration; comparisons to sectional models are quite favorable. MATRIX is incorporated into the GISS climate model and simulations are carried out primarily to assess its performance/efficiency for global-scale atmospheric model application. Simulation results were compared with aircraft and station measurements of aerosol mass and number concentration and particle size to assess the ability of the new method to yield data suitable for such comparison. The model accurately captures the observed size distributions in the Aitken and accumulation modes up to particle diameter 1 μm, in which sulfate, nitrate, black and organic carbon are predominantly located; however the model underestimates coarse-mode number concentration and size, especially in the marine environment

Cloud-Resolving Model Simulations of Aerosol-Cloud Interactions Triggered by Strong Aerosol Emissions in the Arctic

Science.gov (United States)

Wang, H.; Kravitz, B.; Rasch, P. J.; Morrison, H.; Solomon, A.

2014-12-01

Previous process-oriented modeling studies have highlighted the dependence of effectiveness of cloud brightening by aerosols on cloud regimes in warm marine boundary layer. Cloud microphysical processes in clouds that contain ice, and hence the mechanisms that drive aerosol-cloud interactions, are more complicated than in warm clouds. Interactions between ice particles and liquid drops add additional levels of complexity to aerosol effects. A cloud-resolving model is used to study aerosol-cloud interactions in the Arctic triggered by strong aerosol emissions, through either geoengineering injection or concentrated sources such as shipping and fires. An updated cloud microphysical scheme with prognostic aerosol and cloud particle numbers is employed. Model simulations are performed in pure super-cooled liquid and mixed-phase clouds, separately, with or without an injection of aerosols into either a clean or a more polluted Arctic boundary layer. Vertical mixing and cloud scavenging of particles injected from the surface is still quite efficient in the less turbulent cold environment. Overall, the injection of aerosols into the Arctic boundary layer can delay the collapse of the boundary layer and increase low-cloud albedo. The pure liquid clouds are more susceptible to the increase in aerosol number concentration than the mixed-phase clouds. Rain production processes are more effectively suppressed by aerosol injection, whereas ice precipitation (snow) is affected less; thus the effectiveness of brightening mixed-phase clouds is lower than for liquid-only clouds. Aerosol injection into a clean boundary layer results in a greater cloud albedo increase than injection into a polluted one, consistent with current knowledge about aerosol-cloud interactions. Unlike previous studies investigating warm clouds, the impact of dynamical feedback due to precipitation changes is small. According to these results, which are dependent upon the representation of ice nucleation

Etat des lieux de la gestion des insecticides au Togo, Afrique de l ...

African Journals Online (AJOL)

Pour parvenir à une gestion optimale des maladies à transmission vectorielle ou tout au moins la nuisance culicidienne, une surveillance permanente des facteurs de risque devient nécessaire. Le principal facteur de risque est le vecteur qui transmet la maladie, et le contrôle du vecteur passe par des stratégies de lutte qui ...

Development and first application of an Aerosol Collection Module (ACM) for quasi online compound specific aerosol measurements

Science.gov (United States)

Hohaus, Thorsten; Kiendler-Scharr, Astrid; Trimborn, Dagmar; Jayne, John; Wahner, Andreas; Worsnop, Doug

2010-05-01

Atmospheric aerosols influence climate and human health on regional and global scales (IPCC, 2007). In many environments organics are a major fraction of the aerosol influencing its properties. Due to the huge variety of organic compounds present in atmospheric aerosol current measurement techniques are far from providing a full speciation of organic aerosol (Hallquist et al., 2009). The development of new techniques for compound specific measurements with high time resolution is a timely issue in organic aerosol research. Here we present first laboratory characterisations of an aerosol collection module (ACM) which was developed to allow for the sampling and transfer of atmospheric PM1 aerosol. The system consists of an aerodynamic lens system focussing particles on a beam. This beam is directed to a 3.4 mm in diameter surface which is cooled to -30 °C with liquid nitrogen. After collection the aerosol sample can be evaporated from the surface by heating it to up to 270 °C. The sample is transferred through a 60cm long line with a carrier gas. In order to test the ACM for linearity and sensitivity we combined it with a GC-MS system. The tests were performed with octadecane aerosol. The octadecane mass as measured with the ACM-GC-MS was compared versus the mass as calculated from SMPS derived total volume. The data correlate well (R2 0.99, slope of linear fit 1.1) indicating 100 % collection efficiency. From 150 °C to 270 °C no effect of desorption temperature on transfer efficiency could be observed. The ACM-GC-MS system was proven to be linear over the mass range 2-100 ng and has a detection limit of ~ 2 ng. First experiments applying the ACM-GC-MS system were conducted at the Jülich Aerosol Chamber. Secondary organic aerosol (SOA) was formed from ozonolysis of 600 ppbv of b-pinene. The major oxidation product nopinone was detected in the aerosol and could be shown to decrease from 2 % of the total aerosol to 0.5 % of the aerosol over the 48 hours of

Des Connaissances Aux Politiques

International Development Research Centre (IDRC) Digital Library (Canada)

Les synergies ont été mises en commun au fur et à mesure des progrès de la recherche. .... Recherche normative (sur le rôle et la performance des institutions .... Système national d'information sur la gestion environnementale connecté à 19 ...... Un fort contrôle centralisé sur l'élaboration des politiques nationales peut ...

Rôle et limites des tiers-lieux dans la fabrique des villes contemporaines

OpenAIRE

Besson, Raphaël

2017-01-01

La notion de tiers-lieux se développe de manière essentiellement empirique. Elle recouvre des réalités multiples, comme des projets de coworking spaces, de living labs et de fab labs. Certains tiers-lieux s’intéressent tout particulièrement à la ville et aux nouvelles conditions de la fabrique urbaine. En s’appuyant sur des méthodes d’innovation ouverte et le potentiel des outils numériques, ces tiers-lieux défendent l’idée d’un urbanisme qui ne soit plus le patrimoine exclusif d’experts, mai...

Aerosol science: theory and practice

International Nuclear Information System (INIS)

Williams, M.M.R.; Loyalka, S.K.

1991-01-01

The purpose of this book is twofold. First, it is intended to give a thorough treatment of the fundamentals of aerosol behavior with rigorous proofs and detailed derivations of the basic equations and removal mechanisms. Second, it is intended to provide practical examples with special attention to radioactive particles and their distribution in size following a radioactive release arising from an accident with a nuclear system. We start with a brief introduction to the applications of aerosol science and the characteristics of aerosols in Chapter 1. In Chapter 2, we devote considerable attention to single and two particle motion with respect to both translation and rotation. Chapter 3 contains extensive discussion of the aerosol general dynamical equation and the dependences of aerosol distributions on size, shape, space, composition, radioactivity, and charge. Important particle rate processes of coagulation, condensation, and deposition/resuspension are discussed in the chapters 4, 6 and 7, respectively. In Chapter 5, we provide a thorough treatment of the analytical and numerical methods used in solving the various forms of the aerosol dynamical equation. We discuss the importance and applications of aerosol science to nuclear technology and, in particular, the nuclear source term in Chapter 8. Our focus in this chapter is on discussions of nuclear accidents that can potentially release large amount of radioactivity to environment. We also discuss the progress that has been made in understanding the natural and engineered aerosol processes that limit or affect such releases. (author)

L'incidence du prix et des stratégies d'emballage des produits du ...

International Development Research Centre (IDRC) Digital Library (Canada)

Des données internationales, en provenance surtout des pays à revenu élevé, ... pour s'attaquer aux stratégies de marketing ciblant des groupes vulnérables dans ... Les conclusions d'un programme financé par le CRDI au premier plan de la ...

National inventory of radioactive wastes; Inventaire national des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

NONE

1997-12-31

There are in France 1064 sites corresponding to radioactive waste holders that appear in this radioactive waste inventory. We find the eighteen sites of E.D.F. nuclear power plants, The Cogema mine sites, the Cogema reprocessing plants, The Cea storages, the different factories and enterprises of nuclear industry, the sites of non nuclear industry, the Andra centers, decommissioned installations, disposals with low level radioactive wastes, sealed sources distributors, national defence. (N.C.). 16 refs.

National inventory of radioactive wastes; Inventaire national des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-12-31

There are in France 1064 sites corresponding to radioactive waste holders that appear in this radioactive waste inventory. We find the eighteen sites of E.D.F. nuclear power plants, The Cogema mine sites, the Cogema reprocessing plants, The Cea storages, the different factories and enterprises of nuclear industry, the sites of non nuclear industry, the Andra centers, decommissioned installations, disposals with low level radioactive wastes, sealed sources distributors, national defence. (N.C.). 16 refs.

The management of radioactive wastes; La gestion des dechets radioactifs

Energy Technology Data Exchange (ETDEWEB)

NONE