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Sample records for geologie chimie archeologie

  1. Mass spectrometry. Environment, biology, oenology, medicine, geology, chemistry, archaeology, mechanisms; Spectrometrie de masse. Environnement, biologie, oenologie, medecine, geologie, chimie, archeologie, mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This document provides the papers (communications and posters) presented at the 16. French days of mass spectrometry, held September 6-9, 1999 in Nancy, France. 7 papers are interesting for the ETDE database and are analyzed separately. (O.M.)

  2. Mass spectrometry. Environment, biology, oenology, medicine, geology, chemistry, archaeology, mechanisms; Spectrometrie de masse. Environnement, biologie, oenologie, medecine, geologie, chimie, archeologie, mecanismes

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-07-01

    This document provides the papers (communications and posters) presented at the 16. French days of mass spectrometry, held September 6-9, 1999 in Nancy, France. 5 papers are interesting for the INIS database and are analyzed separately. (O.M.)

  3. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2014-01-01

    Cours : Chimie biologique radicalaire : de l’origine de l’ADN au métabolisme d’aujourd’hui Il est généralement admis que les radicaux libres, espèces chimiques très réactives, sont des poisons pour les systèmes vivants qui ont élaboré des mécanismes efficaces pour s’en protéger et s’en débarrasser lorsqu’ils viennent à se former, par accident. Par exemple ce qu’on appelle communément le stress oxydant est une situation caractérisée par une accumulation de radicaux issus de l’oxygène moléculai...

  4. Chimie des interactions moléculaires

    OpenAIRE

    Lehn, Jean-Marie

    2010-01-01

    Le cours de l’année 2008-2009 a porté sur « Autoorganisation et dynamique moléculaires ». Des cours ont été donnés à l’Université de Strasbourg (3 h), à l’Université Charles de Prague (3 h) et à la City University de Hong Kong (3 h). Cours au Collège de France : Autoorganisation et dynamique moléculaires Introduction Le cours a porté sur l’évolution de la chimie supramoléculaire vers la chimie dynamique constitutionnelle (CDC) et la chimie adaptative. Du fait de la labilité des interactions n...

  5. 2011 : Année internationale de la chimie

    OpenAIRE

    2011-01-01

    Lors de la 63e assemblée générale des Nations Unies, 2011 a été proclamée année internationale de la chimie. En France, les acteurs de la chimie sont mobilisés pour promouvoir quatre objectifs : mettre l’accent sur l’importance de la chimie pour un développement durable dans tous les aspects de la vie sur la planète ; accroître chez les jeunes l’intérêt pour la chimie ; susciter l’enthousiasme pour une chimie tournée vers l’avenir ; célébrer les travaux de Marie Curie et la contribution des f...

  6. Arco chimie focuses on PA at FOS

    International Nuclear Information System (INIS)

    Jackson, D.

    1992-01-01

    Arco Chimie France (Fos-sur-Mer), at a recent meeting at its southern France manufacturing site, emphasized that future strategy is strongly focused on its propylene oxide (PO) and derivatives activities. The F2.5 billion ($466 million)-Fe billion/year operation manufactures 200,000 m.t./year of PO, about 70% for captive use and the balance for the merchant market; 550,000 m.t./year of methyl tert butyl ether (MTBE); 97,000 m.t./year of polyols; and 70,000 m.t./year of propylene glycols. There has been talk of Arco modifying its Fos MTBE plant to make it flexible for ethyl tert-butyl ether (ETBE) output; the parent company already operates an MTBE/ETBE pilot unit at Corpus Christi, TX. But Arco Chimie notes there is insufficient bioethanol feedstock availability to convert all production to ETBE. The company would also require investment in new storage capacity for ethanol and ETBE. However, France's biofuels program is not yet clearly defined, and it is politically sensitive because it depends heavily on government subsidies offered to farmers. That, says Arco, makes it impossible to have an accurate idea of how much ethanol will be available

  7. Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts; Reunion de la Societe Geologique de France - Uranium: geologie, geophysique, chimie. Recueil des resumes

    Energy Technology Data Exchange (ETDEWEB)

    Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

    2010-11-15

    This document brings together the abstracts of the 39 presentations given at this meeting days on uranium, organized by the French geological society, and dealing with: 1 - Prospective study of the electronuclear technological transition; 2 - The front-end of the nuclear cycle: from the molecule to the process; 3 - Geophysics: recent changes; 4 - Use of well logging in uranium exploration; 5 - Genetical classification of thorium deposits; 6 - Genetical nomenclature of uranium sources; 7 - Uranium deposits linked to a Proterozoic discordance - retrospective; 8 - The use of spectral analysis techniques in uranium exploration: real-time mapping of clay alteration features; 9 - Development of functionalized silk-screened carbon electrodes for the analysis of uranium trace amounts; 10 - Study of the actinides solvation sphere in organic environment; 11 - Thermodynamic of uraniferous phases of interest for the nuclear cycle; 12 - Heap leaching of marginal minerals at Somair: from lab studies to the production of 700 t of uranium/year; 13 - Agglomeration phenomenology and role of iron in uranium heap leaching; 14 - Chloride uranyl complexes up to 300 deg. C along the saturation vapour curve: Raman spectroscopy analysis and metallogenic consequences; 15 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): vertical variability of argillaceous weathering; 16 - Weathering systems in the Shea Creek deposit (Athabasca, Canada): contribution of irradiation defects in clays to the tracing of past uranium migrations; 17 - Uranium concentrations in mineralizing fluids of the Athabasca basin: analytical and experimental approach; 18 - Paleo-surfaces and metallic rooting: the autochthonous uranium of pre-Athabasca paleo-alterites, Canada; 19 - Distribution of argillaceous parageneses in the Imouraren deposit - Niger; 20 - Heat flux and radioelements concentration (U, Th, K) of precambrian basements: implications in terms of crust growth mechanisms, paleo-temperature, and metallogenic provinces; 21 - Magmatic-hydrothermal transition in the Roessing pegmatite: implications for uranium mineralisation; 22 - Deformation and partial fusion of a Archean-paleo-Proterozoic crust: implication on uraniferous ores mobilization and deposition, Torngats orogenesis, Ungava bay; 23 - Black chert pebbles of the Pongola basin conglomerates ({approx}2, 9 Ga - South Africa): a potential uranium source?; 24 - origin and evolution of detrital pyrites in meso-Archean conglomerates (3.08-2.64 Ga) of South Africa: uranium source or trap?; 25 - Experimental study of U(VI) carbonates with respect to 3 parameters: pH, carbonate concentration, temperature, using vibrational (Raman, FTIR, ATR) and optical (UV-visible) spectroscopy; 26 - Nature and significance of the contact between the Abbabis gneiss complex and the meta-sedimentary sequences of the Damara orogenic belt; 27 - Metallogenic potentialities of Proterozoic orogenic belts accreted to Archean basements: the Damara/Lufilien orogen - Namibia and Zambia; 28 - Contribution of the Geological Exploration to the development of the KATCO ISR mine - Chu-Sarysu basin, Kazakhstan; 29 - Remarks about some remarkable events which occurred during the Francevillien formation; 30 - Geochemical signature of different mineral phases obtained by ICP-MS laser ablation (trace elements and rare earths): Application Uranium deposits; 31 - Role of fluids and irradiation in complex pegmatite euxenite/zircon assemblies from Norway and their U-Pb geochronological consequences; 32 - Mechanical modeling of rupture around metamictic minerals; 33 - Helium diffusion in apatite: Effect alpha recoil-linked damages; 34 - Rare earth spectra in uranium oxides: a marker of the uranium deposit type; 35 - Rare earths: tracers of uranium behaviour during acid sulphated hydrothermal weathering - the Guadeloupe example; 36 - What metallogenic model for the Kiggavik-Andrew Lake trend? Nunavut, Canada; 37 - Uranium mobility in the Southern Armorican system; 38 - Uranium Clusters: Models for Environmentally Relevant Species; 39 - Uranium speciation in Nopal I opals - Sierra Pena Blanca, Mexico

  8. Natural and anthropogenic environmental hazards. Research results of the Department of Applied Geology; Natuerliche und anthropogene Umweltgefaehrdungen. Forschungsergebnisse aus dem Lehrstuhl fuer Angewandte Geologie

    Energy Technology Data Exchange (ETDEWEB)

    Czurda, K.; Eiswirth, M.; Hoetzl, H. [comps.

    1998-12-31

    Applied geology is employed in mining geology, raw materials geology, engineering geology, and hydrogeology, of which the two last-mentioned are the most important for the Department of Applied Geology. This series of publications arose from the need of making research findings, dissertations, theses and conference papers accessible to the public faster and more comprehensively than in national and international journals. [Deutsch] Die Aufgaben der angewandten Geologie sind im weitesten Sinne in der Montangeologie, in der Rohstoffgeologie, in der Ingenieurgeologie und in der Hydrogeologie zu sehen. Der engere Aufgabenbereich der Institute fuer Angewandte Geologie konzentriert sich der heutigen Fragestellung entsprechend meist auf die Ingenieurgeologie und Hydrogeologie. Wenn wir daraus noch die Umweltgeologie ableiten, so ist der Lehr- und Forschungsschwerpunkt auch des Karlsruher Lehrstuhles fuer Angewandte Geologie (AGK=Angewandte Geologie Karlsruhe) umrissen. Die vorliegende Schriftenreihe ist aus der Notwendigkeit entstanden, Forschungsergebnisse, Dissertationen und ausgewaehlte Diplomarbeiten sowie Beitraege einschlaegiger Tagungen in Karlsruhe rascher und u.U. umfangreicher als in internationalen oder nationalen Journalen moeglich zu publizieren. (orig.)

  9. Un siècle de chimie à l'Académie royale des sciences

    OpenAIRE

    Coorebyter, Vincent de; Decaix, Véronique; Franckowiak, Rémi; Francobandiera, Daria; Ierna, Carlo; Jolly, Edouard; Joly, Bernard; Joly, Bernard; Joly, Bernard; Joly, Bernard; Lehman, Christine; Masselot, Nathanaël; Mazet, Edmond; Parmentier, Marc; Parmentier, Marc

    2012-01-01

    Le laboratoire alchimique, lieu privilégié de l’élaboration de la chimie ancienne, symbolisait à la fois le caractère privé, si ce n’est secret, de cette science et sa nécessaire articulation avec une pratique qui lui donnait son sens : il ne s’agissait pas seulement de trouver la pierre philosophale, mais aussi de fabriquer médicaments et substances chimiques répondant à des demandes sociales. L’introduction de la chimie parmi les « classes » de l’Académie royale des sciences va transformer ...

  10. [Précis de chimie organique (1844-1846) and the Traité de chimie organique (1853-1856) from Charles Gerhardt].

    Science.gov (United States)

    Delort, Marie

    2007-07-01

    In 1844 and in 1853 Charles Gerhardt writes two textbooks about organic chemistry: Précis de chimie organique and Traité de chimie organique. In these textbooks Gerhard presents a way to arrange organic compounds in series. The Traité is more accomplished. The classification has improved. His idea is that all organic compounds are based on four main types (i.e., hydrogen, hydrogen chloride, ammonia, and water). Why did Gerhardt chose to develop his theories in a textbook and not in scientific papers? We can think of a few reasons: in a textbook he could articulate ideas and could give constitency to his theories. It is longer than a paper. Textbook authors are less rescricted. The readers are students.

  11. Fontenelle et la chimie : la recherche d’une « loi fondamentale » pour la chimie

    Directory of Open Access Journals (Sweden)

    Luc Peterschmitt

    2012-03-01

    Full Text Available Dans cet article, je propose de reprendre la position de Fontenelle à l’endroit de la chimie. C’est une science qu’il connaît mal avant de devenir Secrétaire de l’Académie Royale des Sciences, et dont il doit, comme Secrétaire de l’institution, chercher une légitimité qu’il a contesté à titre personnel. Or la façon dont il rend compte des mémoires de chimie montre que Fontenelle accompagne l’évolution de cette science à partir de 1699, en se montrant ouvert à ce qu’elle propose de nouveauté. Certes, il rejette ce qu’il identifie comme chimie ancienne, en coupant ainsi la chimie du début du 18e siècle de son histoire. Cette opération rhétorique ne doit pas tromper et ne signifie pas qu’il considère que la chimie qui se fait sous ses yeux n’est pas un savoir. Au contraire, il salue ce qui la met sur la voie de la science. Cela le conduit sans doute à insister sur tous les éléments mécanistes utilisés par certains chimistes. S’en tenir là reviendrait toutefois à manquer son importante réflexion sur les affinités à partir de 1718 : pour Fontenelle, elles donnent la « loi fondamentale » de la chimie. La recherche des affinités, en tant qu’elles sont distinctes de l’attraction newtonienne ou des anciennes sympathies occultes, instituent pour Fontenelle la chimie comme une science de plein droit, même si elle échappe à l’explication mécaniste.In this paper, my aim is to reexamine Fontenelle’s position as to chemistry. Before he became the Secretary of the Académie Royale des Sciences of Paris, Fontenelle knew chemistry quite badly and he ridiculed it in his personal works; but as the Secretary of the institution he has to justify its existence a science. The way in which he accounts for the memoirs of chemistry shows that Fontenelle follows the evolution of this science from 1699, proving that he is aware of its novelties. Of course, Fontenelle keeps rejecting what he identifies

  12. Archeologie středověkých konstrukčních technologií - sbíjená rakev s panty a kruhovými úchyty z pohřebiště při kostele sv. Klimenta ve Staré Boleslavi

    Czech Academy of Sciences Publication Activity Database

    Boháčová, Ivana; Hošek, Jiří

    2014-01-01

    Roč. 39, č. 1 (2014), s. 241-255 ISSN 0231-5823. [Mezinárodní konference archeologie středověku /45./. Kutná Hora, 16.09.2013-19.09.2013] Institutional support: RVO:67985912 Keywords : burials * coffin * construction * Middle Ages * Bohemia Subject RIV: AC - Archeology, Anthropology, Ethnology

  13. La chimie du XVIIe siècle : une question de principes

    Directory of Open Access Journals (Sweden)

    Rémi Franckowiak

    2008-04-01

    Full Text Available Le tournant du XVIIe au XVIIIe siècle est une période décisive pour l’histoire de la chimie qui passe de la reconnaissance institutionnelle à la contestation de son fondement théorique, pour apparaître au final comme la seule partie de la Physique à pouvoir prétendre atteindre la « vérité certaine ». Ce qui se joue alors n’est rien de moins que la redéfinition de ses principes, à savoir son socle de vérités sur lequel s’appuie la science chimique. Cette période est en fait la dernière étape de l’évolution du rapport entre les deux dimensions – théorique et pratique – dans lesquelles se déploie la chimie, qui a vu, par le développement de l’usage des principes dits seconds, l’ensemble des principes chimiques entrainé vers un réalisme empirique, ayant pour effet d’ôter de la chimie toute cohérence théorique. Aussi l’apparition du mécanisme – pas plus celui de Boyle – n’est-il en réalité responsable du bouleversement que connaît la chimie ; elle n’est pas davantage responsable de sa régénération au tout début du XVIIIe siècle. La conscience de la faiblesse théorique de la chimie va devenir pour elle promesse de vigueur théorique sur la base de ce qui représente sa force : l’expérience. À la suite de la perte de ce qui fut certitude, le chimiste devient un être à ré-instruire. Un chimiste tel que Samuel Cottereau Du Clos illustre parfaitement le passage d’une science chimique comme connaissance des principes à une chimie comme science cette fois du vraisemblable.The last decades of 17th century represent a decisive period for the history of Chemistry which switched from institutional recognition to dispute of its theoretical basis, to seem finally, during the very first years of the next century, the only part of Physics being able to claim reaching the “unquestionable truth”. What did happen then is nothing less than the redefinition of principles of Chemistry

  14. Les Nobel juifs de chimie le partage du savoir au XX siècle

    CERN Document Server

    Benguigui, Isaac

    2010-01-01

    L'un des traits marquants et remarquables des Juifs tout au long de leur histoire, plusieurs fois millénaire, a été leur créativité dans tous les domaines, en particulier dans le domaine scientifique. Ils ont participé de façon impressionnante à la remise en cause des valeurs, au démantèlement des dogmes et à l'irruption des forces cachées. On peut d'emblée souligner que la contribution des Juifs à la science a été sans commune mesure avec le pourcentage de la population qu'ils représentent. Cela reste vrai pour la chimie du XXe siècle. A travers la vie et l'oeuvre de 23 prix Nobel de chimie, l'auteur nous livre une histoire passionnante de ces hommes, biens souvent des exilés et d'origine modeste. dont la science fut leur vocation et le partage du savoir leur crédo.

  15. [The "Journal de Pharmacie et de Chimie" and the two world wars].

    Science.gov (United States)

    Bonnemain, Bruno

    2011-02-01

    The "Journal de Pharmacie et de Chimie" was the official publication of the Société de Pharmacie de Paris which became later on the French Academy of pharmacy. It is consequently the organ that presented scientific publications and independent position papers from pharmacists being part of this assembly and coming from universities, drugstores or pharmaceutical industries. We have analyzed the content of this journal during the last two world wars in order to evaluate to what extent the members of the Société de Pharmacie de Paris were part of the war efforts, and encouraged or criticized the on-going events. We can observe that, in both cases, pharmacists used their expert opinions to better react and manage consequences of the conflicts, but also to express their disagreement with enemy's opinions or actions, the Society doing everything possible to maintain its activities. One can observe also that both conflicts were an opportunity to reconsider the organization of pharmacy in France, especially during the Second World War where took place discussions on pharmacy reform (1941 law) and creation of the Pharmacists' Order which will ultimately occur after the war end.

  16. Silver Vanadium Phosphorous Oxide, Ag(2)VO(2)PO(4): Chimie Douce Preparation and Resulting Lithium Cell Electrochemistry.

    Science.gov (United States)

    Kim, Young Jin; Marschilok, Amy C; Takeuchi, Kenneth J; Takeuchi, Esther S

    2011-08-15

    Recently, we have shown silver vanadium phosphorous oxide (Ag(2)VO(2)PO(4), SVPO) to be a promising cathode material for lithium based batteries. Whereas the first reported preparation of SVPO employed an elevated pressure, hydrothermal approach, we report herein a novel ambient pressure synthesis method to prepare SVPO, where our chimie douce preparation is readily scalable and provides material with a smaller, more consistent particle size and higher surface area relative to SVPO prepared via the hydrothermal method. Lithium electrochemical cells utilizing SVPO cathodes made by our new process show improved power capability under constant current and pulse conditions over cells containing cathode from SVPO prepared via the hydrothermal method.

  17. Wilhelm Homberg et la chimie de la lumière

    Directory of Open Access Journals (Sweden)

    Lawrence M. Principe

    2008-03-01

    Full Text Available En 1705, Wilhem Homberg, le principal chimiste de l’Académie royale des sciences, proposa une nouvelle théorie chimique selon laquelle le Soufre principe des corps mixtes était identique à la lumière. Il affirma par la suite que cette lumière corporelle était la seule source d’activité et de changement dans les substances matérielles. Cet article montre comment la théorie de Homberg s’élabora progressivement pendant de nombreuses années sous l’influence de ses observations et des résultats de ses expériences de laboratoire, ce qui nous fournit un exemple de la manière selon laquelle un chimiste du début du XVIIIe siècle a pu développer une théorie raffinée grâce à l’interaction de la réflexion et de la manipulation. L’influence probable de la théorie de Homberg sur les fameuses « questions chimiques » de Newton est également signalée ici pour la première fois. Enfin l’article avance que nous comprendrons plus précisément l’histoire de la chimie si nous reconnaissons le caractère spécifique de la chimie et sa relative autonomie, plutôt que si nous cherchons à lui imposer des développements faciles et convenus tirés d’autres champs du savoir comme la philosophie ou la physique.In 1705, Wilhelm Homberg, the chief chemist of the Académie Royale des Sciences, proposed a new chemical theory that the Sulphur principle of mixed bodies was identical with light. He claimed further that this embodied light was the sole source of activity and change in material substances. This paper traces how Homberg’s theory emerged gradually over many years under the influence of his observations and the results of his laboratory experiments. It thus provides an example of how an early eighteenth-century chemist developed a sophisticated theory through the interplay of mind and hand. The probable influence of Homberg’s theory on Isaac Newton’s famous “chymical queries” is also noted here for the first

  18. La micro-échelle en synthèse organique : un outil commun chimie/génie chimique

    OpenAIRE

    Prat , Laurent E.; Loubiere , Karine; Dechy-Cabaret , Odile

    2014-01-01

    National audience; Cet article est une restitution courte de la présentation réalisée au cours des JIREC 2013 sur l'enseignement de la notion de changement d'échelle et de passage d'un mode batch à un mode continu en synthèse organique. L'enjeu est de faire travailler des étudiants issus des départements chimie et génie chimique autour d'un même outil, le microréacteur. Au cours d'une séance de travaux pratiques, les étudiants mettent en oeuvre une synthèse organique en continu à micro-échell...

  19. [The Journal de chimie médicale (Journal of Medical Chemistry) : a major innovation on French public health during the 19th century ].

    Science.gov (United States)

    Bonnemain, Bruno

    2017-03-01

    JBA Chevallier is first known for his publication in 1850 of his book on falsifications. But he had also a major role for the opening of the pharmacy world to toxicological and Public Health issues, through the founding in 1825, and the management for more than 50 years, of the Journal de chimie médicale, de pharmacie et de toxicologie (Journal of Medical Chemistry, of Pharmacy and of Toxicology). The purpose of the present study has been to look at the evolution of that publication over the years and to compare its content with the reference pharmaceutical journal at that time : the Journal de pharmacie et de chimie (Journal of Pharmacy and Chemistry). One can observe that the editorial lines of both journals will progressively diverge from each other, but Chevallier remained strongly connected with pharmacy, his journal merging finally in 1876 with the Répertoire de pharmacie (Index of Pharmacy).

  20. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France); La geologie de l'uranium dans le massif granitique de Saint-Sylvestre (Limousin - Massif Central Francais)

    Energy Technology Data Exchange (ETDEWEB)

    Marquaire, C.; Moreau, M.; Barbier, J.; Ranchin, G.; Carrat, H.G.; Coppens, R.; Senecal, J.; Koszotolanyi, C.; Dottin, H

    1969-07-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [French] Ce memoire est consacre a la geologie de l'uranium dans le Limousin, plus specialement dans le massif de St-Sylvestre, et aux phenomenes qui s'y rattachent: geologie regionale, phenomenes de zonalite petrographique et geochimique dans certains massifs granitiques, mouvements de l'uranium lies a l'alteration superficielle, geochronologie du minerai d'uranium. L'ouvrage comprend six articles qui recouvrent les differents aspects scientifiques enumeres. Chacun de ces six articles est precede d'un resume. La composition du memoire st la suivante: Marcel ROUBAULT, Preface. 1. Ch. MARQUAIRE, M. MOREAU Esquisse geologique du

  1. The geology of uranium in the Saint-Sylvestre granite district (Limousin, Massif Central, France); La geologie de l'uranium dans le massif granitique de Saint-Sylvestre (Limousin - Massif Central Francais)

    Energy Technology Data Exchange (ETDEWEB)

    Marquaire, C; Moreau, M; Barbier, J; Ranchin, G; Carrat, H G; Coppens, R; Senecal, J; Koszotolanyi, C; Dottin, H

    1969-07-01

    This report concerns the geology of uranium in Limousin, more particularly in the St-Sylvestre massif, and the related phenomena: regional geology, petrographic and geochemical zonal distribution observed in various granite massifs, uranium movement in connection with surface alteration, geochronology of uranium ore. The work is made up of six articles covering the various scientific aspects listed above. Each article is headed with an abstract. The paper comprises the following chapters: Foreword by Marcel ROUBAULT. 1. Ch. MARQUAIRE, M. MOREAU Outline of geological conditions in Northern Limousin and distribution of uraniferous occurrences. 2. J. BARBIER, G. RANCHIN, H. G. CARRAT and R. COPPENS Geology of the St-Sylvestre Massif and uranium geochemistry - Introduction to laboratory studies - Problems of methodology. 3. J. BARBIER and G. RANCHIN Petrographical and geochemical zones in the St-Sylvestre granite massif (Limousin - French 'Massif Central'). 4. J. BARBIER and G. RANCHIN Uranium geochemistry in the St-Sylvestre Massif (Limousin - French 'Massif Central') - Occurrences of primary geochemical uranium and replacement processes. 5. J. SENEGAL Monograph of the Brugeaud orebody. 6. R. COPPENS, Ch. KOSZTOLANYI and H. DOTTIN Geochronological study of the Brugeaud mine. 1969. (authors) [French] Ce memoire est consacre a la geologie de l'uranium dans le Limousin, plus specialement dans le massif de St-Sylvestre, et aux phenomenes qui s'y rattachent: geologie regionale, phenomenes de zonalite petrographique et geochimique dans certains massifs granitiques, mouvements de l'uranium lies a l'alteration superficielle, geochronologie du minerai d'uranium. L'ouvrage comprend six articles qui recouvrent les differents aspects scientifiques enumeres. Chacun de ces six articles est precede d'un resume. La composition du memoire st la suivante: Marcel ROUBAULT, Preface. 1. Ch. MARQUAIRE, M. MOREAU Esquisse geologique du Nord Limousin et repartition des mineralisations

  2. ACDV, Association Chimie du Végétal : une initiative française pour développer la chimie du végétal

    Directory of Open Access Journals (Sweden)

    Friès Aurore

    2013-01-01

    Full Text Available Industry dependence on external fossil fuel resources, fluctuations in energy and raw materials costs, climate change, environmental regulations, changing consumer attitudes etc. In France, where agriculture and the chemical industry are two pillars of the economy, these harsh realities have prompted the chemical and agro-resources sectors to look to biobased chemistry as a means of diversifying outlets for biomass and chemical sourcing, with the aim of balanced use. French players in this international sector have realised the value of joining forces, pooling skills, knowhow and resources into a single structure to drive forward the development of biobased chemistry. This shared vision and determination resulted in the creation in 2008 of the French biobased chemistry association, Association Chimie du V_eg_etal (ACDV. This initiative, still the first of its kind, brings together within a single federation all those directly involved in biobased chemistry. ACDV’s stated aim: to propose and create industrial, economic and political conditions conducive to the development of this industrial reality, within a context of competitive, responsible and sustainable agricultural and chemical sectors. ACDV acts as a source of creative ideas, presenting national and European bodies with the strategic vision and position of French industrialists as regards the international development and competitiveness of biobased chemistry. A commitment by the French chemicals industry to a target of 15% biobased raw materials by 2017 is one of the key factors underpinning the work of the ACDV.

  3. Electrochemical fluorination of La(2)CuO(4): a mild "chimie douce" route to superconducting oxyfluoride materials.

    Science.gov (United States)

    Delville, M H; Barbut, D; Wattiaux, A; Bassat, J M; Ménétrier, M; Labrugère, C; Grenier, J C; Etourneau, J

    2009-08-17

    The fluorination of La(2)CuO(4) was achieved for the first time under normal conditions of pressure and temperature (1 MPa and 298 K) via electrochemical insertion in organic fluorinated electrolytes and led to lanthanum oxyfluorides of general formula La(2)CuO(4)F(x). Analyses showed that, underneath a very thin layer of LaF(3) (a few atomic layers), fluorine is effectively inserted in the material's structure. The fluorination strongly modifies the lanthanum environment, whereas very little modification is observed on copper, suggesting an insertion in the La(2)O(2) blocks of the structure. In all cases, fluorine insertion breaks the translation symmetry and introduces a long-distance disorder, as shown by electron spin resonance. These results highlight the efficiency of electrochemistry as a new "chimie douce" type fluorination technique for solid-state materials. Performed at room temperature, it additionally does not require any specific experimental care. The choice of the electrolytic medium is crucial with regard to the fluorine insertion rate as well as the material deterioration. Successful application of this technique to the well-known La(2)CuO(4) material provides a basis for further syntheses from other oxides.

  4. La fouille de graphes dans les bases de données réactionnelles au service de la synthèse en chimie organique

    OpenAIRE

    Pennerath , Frédéric; Napoli , Amedeo

    2006-01-01

    National audience; La synthèse en chimie organique consiste à concevoir de nouvelles molécules à partir de réactifs et de réactions. Les experts de la synthèse s'appuient sur de très grandes bases de données de réactions qu'ils consultent à travers des procédures d'interrogation standard. Un processus de découverte de nouvelles réactions leur permettrait de mettre au point de nouveaux procédés de synthèse. Cet article présente une modélisation des réactions par des graphes et introduit une mé...

  5. Archeologie Custerovy poslední bitvy

    Czech Academy of Sciences Publication Activity Database

    Květina, Petr

    2013-01-01

    Roč. 35, č. 9 (2013), s. 44-47 ISSN 0418-5129 R&D Projects: GA MK(CZ) DF12P01OVV032 Keywords : archaeology * American Indian * metal detector * historical narratives Subject RIV: AC - Archeology, Anthropology, Ethnology

  6. Un siècle de chimie à l’Académie royale des sciences de sa création (1666) à l’arrivée de Lavoisier (1768)

    OpenAIRE

    Joly, Bernard

    2014-01-01

    Le laboratoire alchimique, qui passe volontiers pour le lieu privilégié de l’élaboration de la chimie ancienne, symbolisait à la fois le caractère privé, si ce n’est secret, de cette science et la nécessaire articulation de ses théories avec une pratique qui lui donnait son sens : il ne s’agissait pas seulement de trouver la pierre philosophale, mais aussi de fabriquer des médicaments et des substances chimiques répondant aux demandes sociales. Lieu privé, réservé à des disciples choisis, il ...

  7. Physico-Chimie des Atomcules d'Hélium antiprotonique: Modélisation de Processus réactifs en présence d'Antimatière

    Science.gov (United States)

    Sauge, Sébastien

    2000-07-01

    Environ 3%des antiprotons (p) stoppés dans l'hélium survivent plusieurs microsecondes, contre quelques picosecondes dans tout autre matériau. Cette métastabilité inhabituelle résulte d'une capture sur des états liés de l'atome exotique pHe+, dénommé atomcule car il s'apparente à la fois à un atome de Rydberg quasi-circulaire quasi-classique de grand moment angulaire l n-1 37et à une molécule diatomique composée d'un noyau chargé négativement et caractérisée par une forte excitation rotationnelle J=l. En dehors de cette structure duale originale accessible par spectroscopie laser, la physico-chimie de leur interaction avec d'autres atomes ou molécules a fait l'objet d'études microscopiques. Alors que les atomcules résistent à des millions de collisions dans l'hélium pur, des contaminants moléculaires comme H2 les détruisent immédiatement, y compris à basse température. Dans le cadre Born-Oppenheimer, nous interprétons l'interaction moléculaire, calculée par des techniques de chimie quantique {ab initio}, en termes de chemins réactifs classiques, qui présentent des barrières d'activation compatibles avec celles mesurées dans He et H2.Nous montrons par une approche Monte Carlo de trajectoires classiques que la thermalisation détruit fortement les populations initiales, portant la fraction estimée des états de capture à 3%. Nous étudions aussi la recombinaison dissociative pHe+ + e+ e -dans une approche de trajectoires classiques pour les noyaux: nous prédisons la synthèse d'antihydrogène avec un rapport de branchement de 10%, ainsi qu'une nouvelle classe d'atomcules métastables ?={p}, e+, 2e-, qui pourrait être confirmée par spectroscopie. Ce travail illustre la transférabilité des concepts de chimie physique à l'étude de processus exotiques en présence d'antimatière, et apporte un éclairage nouveau sur la physico-chimie des radicaux interstellaires froids.

  8. The exhibition"La France au CERN" was inaugurated by Danièle Hulin, Directrice adjointe Secteur Physique, Chimie, Sciences pour l'Ingénieur (PCSI), Ministère délégué à l'Enseignement supérieur et à la recherche.

    CERN Document Server

    Patrice Loïez

    2005-01-01

    The exhibition"La France au CERN" was inaugurated by Danièle Hulin, Directrice adjointe Secteur Physique, Chimie, Sciences pour l'Ingénieur (PCSI), Ministère délégué à l'Enseignement supérieur et à la recherche.

  9. Un siècle de chimie à l’Académie royale des sciences de sa création (1666 à l’arrivée de Lavoisier (1768

    Directory of Open Access Journals (Sweden)

    Bernard Joly

    2012-04-01

    Full Text Available Le laboratoire alchimique, qui passe volontiers pour le lieu privilégié de l’élaboration de la chimie ancienne, symbolisait à la fois le caractère privé, si ce n’est secret, de cette science et la nécessaire articulation de ses théories avec une pratique qui lui donnait son sens : il ne s’agissait pas seulement de trouver la pierre philosophale, mais aussi de fabriquer des médicaments et des substances chimiques répondant aux demandes sociales. Lieu privé, réservé à des disciples choisis, il ...

  10. Green chemistry; La chimie verte

    Energy Technology Data Exchange (ETDEWEB)

    Colonna, P. [Institut National de la Recherche Agronomique, Dept. Caracterisation et Elaboration des Produits, 78 - Versailles (France)

    2006-07-01

    The depletion of world fossil fuel reserves and the involvement of greenhouse gases in the global warming has led to change the industrial and energy policies of most developed countries. The goal is now to reserve petroleum to the uses where it cannot be substituted, to implement renewable raw materials obtained from plants cultivation, and to consider the biodegradability of molecules and of manufactured objects by integrating the lifetime concept in their expected cycle of use. The green chemistry includes the design, development and elaboration of chemical products and processes with the aim of reducing or eliminating the use and generation of harmful compounds for the health and the environment, by adapting the present day operation modes of the chemical industry to the larger framework of the sustainable development. In addition to biofuels, this book reviews the applications of green chemistry in the different industrial processes in concern. Part 1 presents the diversity of the molecules coming from renewable carbon, in particular lignocellulose and the biotechnological processes. Part 2 is devoted to materials and treats of the overall available technological solutions. Part 3 focusses on functional molecules and chemical intermediates, in particular in sugar- and fats-chemistry. Part 4 treats of biofuels under the aspects of their production and use in today's technologies. The last part deals with the global approaches at the environmental and agricultural levels. (J.S.)

  11. Physique, chimie 1re S

    CERN Document Server

    2011-01-01

    • Des activités conçues pour correspondre aux pratiques des enseignants ou au temps d’enseignement attribué à une notion. Avec des « Découverte » courtes basées sur les savoirs que possède l’élève en début de chapitre et des « Documentaires » pour construire le cours avec leur « aide aux activités ». Ainsi que des TP pour pratiquer expérimentalement ou exploiter des données. • Un Cours structuré renvoyant aux activités, illustré, enrichi d’applications du cours avec renvois vers les exercices. Il se termine par l’essentiel. • De nombreux Exercices résolus avec des corrections détaillées et après le test de compétences, des exercices classés en entraînement et approfondissement et un exercice en langue anglaise. • Pour satisfaire la curiosité des élèves : Des pages « Culture et Sciences » en fin de cours. Et au long du manuel : L’histoire des sciences et L’histoire des arts. Un site pour les élèves www.micromega-hatier.com • Simulateurs en ...

  12. Description and principles of use of an automatic control device usable, in particular, in analytical chemistry; Description et principes d'utilisation d'un dispositif de commande automatique utilisable, en particulier, en chimie analytique

    Energy Technology Data Exchange (ETDEWEB)

    Rigaudiere, Roger; Jeanmaire, Lucien [Commissariat a l' Energie Atomique - CEA, Centre d' Etudes Nucleaires de Fontenay-aux-Roses, Direction de la Protection et de la Surete Radiologiques, Departement de la Protection Sanitaire, Section de Controle Sanitaire (France)

    1969-07-01

    This note describes an automatic control device for the programming of about 20 different functions, chronologically and during a given time. Any voltage can be chosen at the output to perform the different functions. Three examples of utilisation taken in analytical chemistry are given to illustrate the possibilities offered by this device, but its domain of use is much more universal and independent of the type of functions [French] Description d'un dispositif de commande automatique destine a programmer une vingtaine de fonctions differentes dans l'ordre et pendant le temps desire. Aux bornes d'utilisation de ce dispositif, on peut choisir a volonte du 24 V continu, du 220 V alternatif ou un contact de court-circuit pour realiser les fonctions elles-memes. Afin d'illustrer concretement les possibilites de cet appareil, il est donne trois exemples d'utilisation empruntes a la chimie analytique pour laquelle il a ete prevu initialement. En realite, son domaine d'utilisation est beaucoup plus universel, car il est relativement independant de la nature des fonctions. (auteurs)

  13. Banking of environmental samples for short-term biochemical and chemical monitoring of organic contamination in coastal marine environments: the GICBEM experience (1986-1990). Groupe Interface Chimie Biologie des Ecosystèmes, Marins.

    Science.gov (United States)

    Garrigues, P; Narbonne, J F; Lafaurie, M; Ribera, D; Lemaire, P; Raoux, C; Michel, X; Salaun, J P; Monod, J L; Romeo, M

    1993-11-01

    The GICBEM (Groupe Interface Chimie Biologie des Ecosystèmes Marins) program consists of an evaluation of the ecosystem health status in the Mediterranean Sea mainly based on chemical and biochemical approaches. Specific chemical contaminants (polycyclic aromatic hydrocarbons (PAH), polychlorobiphenyls (PCB), heavy metals) in waters, sediments, and related biotransformation indicators in target organisms (mussels, fish) have been selected for a complete survey of the coastal waters. In order to provide an appropriate sampling program for standardization for each sampling cruise, various aspects have been studied: (a) parameters for the choice of the sample sites; (b) ways of collection the samples (waters, sediments, marine organisms); and (c) preparation of the samples for a short term storage on board ship and for further analyses in the ground laboratory. Methods of preparation and storage of the samples are described and could be used to initiate an environmental banking program including both possible retrospective analyses of chemical pollutants and biochemical indicators. Moreover, the correlation between chemicals (PAH) and biochemical (mixed function oxygenase activities) parameters has been studied and this demonstrates the capability of the enzyme activities as reliable pollution biomarkers.

  14. Role of Exchange Equilibria in Structural Chemistry; Role des Equilibres d'Echange en Chimie Structurale; Rol' ravnovesiya obmena v strukturnoj khimii; Papel de los Equilibrios de Intercambio en Quimica Estructural

    Energy Technology Data Exchange (ETDEWEB)

    Van Wazer, J. R.; Moedritzer, K. [Monsanto Company, St. Louis, MI (United States)

    1965-10-15

    , 16]. The topics reviewed above were exemplified by specific systems [e.g. 2, 12, 24, 28] selected from our recent work. In addition to the equilibrium studies, some attention was given to the kinetics [26, 27] of the exchange processes involved. Several general theorems useful in the a priori prediction of the kinds and amounts of products [ 6,18] were presented. (author) [French] Une grande partie des etudes faites jusqu'a present sur les echanges a ete consacree a l'introduction de substituants monofonctionnels dans des atomes ou fragments de molecule polyfonctionnels, mais il se peut aussi que des molecules compliquees subissent un echange de parties de maniere a parvenir a une distribution en equilibre de molecules de tailles et de formes diverses. L'emploi de la resonance magnetique nucleaire (RMN) a fort pouvoir de resolution dans les recherches sur ces melanges equilibres de composes a fait l'objet de plusieurs communications du Monsanto Co.Laboratory (voir ref. [1-34] a la fin des resumes), en 1964 et 1965. Les systemes etudies par cette methode comprennent plusieurs nouvelles familles de composes; les genres de produits resultant des echanges ont ete definis et leurs quantites determinees en fonction d'un petit nombre de constantes d'equilibre. L'auteur a applique une nouvelle theorie mathematique [6] en vue d'etablir la forme et le nombre minimal de constantes d'equilibres qui relient entre elles structures acycliques et parties de structures moleculaires. En outre, il a etudie quantitativement les equilibres entre structures cycliques et acycliques. L'importance que l'on donne aux composes du carbone (ce que fait ressortir la division de la chimie descriptive en chimie organique et inorganique) est due au fait que les echanges portant sur des liaisons C-C ou des liaisons entre un atome de carbone et un autre atome qui ne presente pas d'orbites de liaison libres de basse energie (par exemple Si, Ge, N, P, As, O, S, Se, F, Cl, Br) sont extremement lents. En

  15. Rijksmuseum van Geologie en Mineralogie 1878-1978 : a retrospect

    NARCIS (Netherlands)

    Groot, de G.E.

    1978-01-01

    Introduction The birth of the RGM The first period (1878-1922) - The new building - Scientific assistants The second period (1922-1955) - The new wing - The Museum in the post-war years The third period (from 1955 onwards) - Plans for removal - A new director References --- Introduction On reading

  16. Nitrous Oxide from Combustion and Industry: Chemistry, Emissions and Control Protoxyde d'azote provenant de la combustion et de l'industrie : chimie, émissions et techniques de réduction

    Directory of Open Access Journals (Sweden)

    De Soete G.

    2006-11-01

    'industrie chimique, d'autre part il s'interroge sur les technologies possibles de destruction de N2O dans les cas où sa teneur dans les fumées ou autres effluves industriels pose des problèmes. Comme les émissions, aussi bien que les moyens de les abattre, sont fortement tributaires des mécanismes chimiques responsables de la production et de la destruction du N2O, une introduction substantielle sur la cinétique homogène et hétérogène de sa formation/réduction, telle qu'elle apparaît dans un contexte de combustion, est fournie, permettant au lecteur de comprendre le pourquoi de ces émissions et le comment des technologies d'abattement suggérées. Dans une première section de l'introduction, on rappelle brièvement la chimie du N2O en phase gazeuse et ses relations avec la chimie du monoxyde d'azote NO (fig. 1 ; l'effet de la température sur la production nette de N2O est accentué, puisqu'elle expliquera en grande partie les émissions relativement élevées de la combustion à basse température, telle qu'elle est mise en oeuvre dans les lits fluidisés (fig. 2. On mentionne pour finir les réactions du système rédox SO2/NO (fig. 3, responsable de la formation artificiellede N2O dans les échantillons de fumées stockés. La deuxième section de l'introduction traite de la chimie hétérogène du protoxyde d'azote, dont la compréhension est actuellement encore relativement fragmentaire. Parmi les mécanismes hétérogènes non catalytiques, figurent principalement : la réduction de N2O sur le carbone constitutif du charbon et du coke, la formation de N2O à partir de l'azote constitutif de ces derniers et la production de N2O par des réactions entre carbone, NO et sulfates. Les deux premiers mécanismes sont traités en parallèle avec ceux, similaires, qui opèrent sur le NO, auxquels ils sont intimement liés (voir tableau 1 et réactions S1 à S8 dans le texte. La réduction de N20 sur carbone constitutif ne produit que peu de N2O, au moins en absence d

  17. Chemistry and propulsion; Chimie et propulsions

    Energy Technology Data Exchange (ETDEWEB)

    Potier, P [Maison de la Chimie, 75 - Paris (France); Davenas, A [societe Nationale des Poudres et des Explosifs - SNPE (France); Berman, M [Air Force Office of Scientific Research, Arlington, VA (United States); and others

    2002-07-01

    During the colloquium on chemistry and propulsion, held in march 2002, ten papers have been presented. The proceedings are brought in this document: ramjet, scram-jet and Pulse Detonation Engine; researches and applications on energetic materials and propulsion; advances in poly-nitrogen chemistry; evolution of space propulsion; environmental and technological stakes of aeronautic propulsion; ramjet engines and pulse detonation engines, automobiles thermal engines for 2015, high temperature fuel cells for the propulsion domain, the hydrogen and the fuel cells in the future transports. (A.L.B.)

  18. A Physics and Tabulated Chemistry Based Compression Ignition Combustion Model: from Chemistry Limited to Mixing Limited Combustion Modes Un modèle de combustion à allumage par compression basé sur la physique et la chimie tabulée : des modes de combustion contrôlés par la chimie jusqu’aux modes contrôlés par le mélange

    Directory of Open Access Journals (Sweden)

    Bordet N.

    2011-11-01

    experimental measurements carried out on a 2 liter Renault Diesel engine and good agreements are found. Ce papier présente une nouvelle approche 0D phénoménologique pour prédire le déroulement de la combustion dans les moteurs Diesel à injection directe pour toutes les conditions d’utilisation usuelles. Le but de ce travail est de développer une approche physique en vue d’améliorer la prédiction de la pression cylindre et du dégagement d’énergie, avec un nombre minimum d’essais nécessaires à la calibration. Les contributions principales de cette étude sont la modélisation de la phase de pré-mélange de la combustion et une extension du modèle pour les stratégies d’injections multiples. Dans ce modèle, le taux de dégagement d’énergie dû à la combustion pour la phase pré-mélangée est relié à un taux de réaction moyen du carburant. Ce taux de réaction moyen de carburant est évalué à l’aide d’une approche basée sur un taux de réaction local de carburant tabulé et la détermination d’une fonction de densité de probabilité (PDF de la fraction de mélange (Z. Cette PDF permet de prendre en compte la distribution de richesse existante dans la zone pré-mélangée. L’allure de cette PDF présumée est une β-fonction standardisée. Les fluctuations de la fraction de mélange sont décrites avec une équation de transport pour la variance de Z. La définition standard de la fraction de mélange, établie dans le cas de flammes de diffusion, est ici adaptée à une combustion pré-mélangée de type Diesel pour décrire l’inhomogénéité de la richesse dans le volume de contrôle. La chimie détaillée est décrite au travers de la tabulation du taux de réaction relatif à la flamme principale et du délai d’auto-inflammation relatif à la flamme froide, ces tabulations sont fonction de la variable d’avancement c, du taux de gaz brûlé ainsi que des grandeurs thermodynamiques telles que la température et la pression. Le

  19. 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

  20. DOSAGE DES ELEMENTS EN TRACE DES CALCAIRES AU SERVICE DE L'ARCHEOLOGIE

    International Nuclear Information System (INIS)

    BLANC, A.; HOLMES, L.; HARBOTTLE, G.

    1998-01-01

    Numerous quarries in the Lutetian limestone formations of the Paris Basin provided stone for the building and the decoration of monuments from antiquity to the present. To determine the origin of stone used for masonry and sculptures in these monuments, a team of geologists and archaeologists has investigated 300 quarries and collected 2,300 samples. Petrographic and paleontologic examination of thin sections allows geologists to distinguish Lutetian limestones from Jurassic and Cretaceous limestones. Geologists also seek to formulate hypotheses regarding the origin of Lutetian limestones used for building and sculpture in the Paris region. In the search for the sources of building and sculptural stone, the analytical methods of geologists are limited because often several quarries produce the same lithofacies. A new tool is now available, however, to attack questions of provenance raised by art historians. Because limestones from different sources have distinctive patterns of trace-element concentrations, compositional analysis by neutron activation allows them to compare building or sculptural stone from one monument with stone from quarries or other monuments. This analytical method subjects a powdered limestone sample to standard neutron activation analysis procedures at Brookhaven National Laboratory. With the help of computer programs, the compositional fingerprints of Lutetian limestones can be determined and stored in a database. The limestone database contains data for approximately 2,100 samples from monuments, sculptures and quarries. It is particularly rich in samples from the Paris Basin

  1. Archeologie na pražském pracovišti NPÚ

    Czech Academy of Sciences Publication Activity Database

    Sommer, Petr

    2015-01-01

    Roč. 31, č. 2 (2015), s. 115-117 ISSN 0231-6056 Institutional support: RVO:67985912 Keywords : cultural heritage * National Institute * archaeological monuments Subject RIV: AC - Archeology, Anthropology, Ethnology

  2. Archeologie sous-marine de l'ancienne Dwarka dans l'Okhamandal

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.

    ancient settlers since the Harappan times (3000 BC) and the oldest site discovered at Nageshwar on the northern shores of Okhamandal (Figure 1). The late phase of the Harappan civilization is noticed at Bet Dwarka Island about 5 km from Okha port. Dwarka...

  3. Chemistry, sun, energy and environment; Chimie, soleil, energie et environnement

    Energy Technology Data Exchange (ETDEWEB)

    Bouchy, M. [Ecole Nationale Superieure des Industries Chimiques (ENSIC), 54 - Villers-les-Nancy (France); Enea, O. [Poitiers Univ., 86 (France); Flamant, G. [IMP-Odeillo-CNRS (France)] (and others)

    2000-07-01

    This document provides the 35 papers presented at the 'Chemistry, Sun, Energy and Environment' meeting, held February 3-4, 2000 in Saint-Avold, France. The main studied topic was the use of solar radiation for water treatment, volatile organic compounds decomposition and in some thermochemical processes. These research subjects are tackled in a fundamental and practical point of view. (O.M.)

  4. De geologie van den Cimone di Margno en den Monte di Muggio

    NARCIS (Netherlands)

    Buning, W.L.

    1931-01-01

    Le terrain étudié (fig. 1) est formé de roches métamorphiques pour plus de la moitié; le reste est formé de sédiments variant du Permien au Trias Inférieur, et de roches appartenant à la culmination éruptivocristalline du Cimone di Margno. Le relief du paysage présente en général des pentes douces.

  5. De ontwikkelingsgeschiedenis van Rein van Bemmelens (1904-1983 undatietheorie: veertig jaar Nederlandse geologie

    Directory of Open Access Journals (Sweden)

    Willemjan Barzilay

    2009-03-01

    Full Text Available The development of Rein van Bemmelens (1904-1983 undation theory: Forty years of Dutch geology The Dutch geologist Rein van Bemmelen was the greatest opponent of plate tectonics in the Netherlands. He lived and worked during an important period in the history of earth sciences. He had studied geology when Wegeners theory was introduced and enthusiastically received in the Netherlands and he worked as a geologists during the period in which, after Wegeners theory was rejected in the Netherlands, several Dutch geologists came with their own theories to explain the origin of continents and oceans and in which plate tectonics was introduced in the Netherlands. He had proposed his own theory, the undation theory, at the beginning of the 1930s and kept on developing it during the following years. He continued to do so until his death in 1983. The history of the undation theory thus sheds light on the history of geology in the Netherlands. I will trace the history of geology in the Netherlands using Rein van Bemmelen and his undation theory as a lense.

  6. De Geologie van het Val Brembo di Foppolo en de Valle di Carisole

    NARCIS (Netherlands)

    Wennekers, J.H.L.

    1928-01-01

    Le terrain exploré fait partie du prolongement vers l’est de la zone des Alpes bergamasques que Cosijn et Jong ont commencé à mettre en carte en 1926 (fig. 1). Il comprend des parties du cristallin situé au nord de la „ligne orobique”, du paquet d’écaillés (série porphyrique, série Collio,

  7. Dr C. Beets (1916-1995) and the 'Rijksmuseum van Geologie en Mineralogie'

    NARCIS (Netherlands)

    Winkler Prins, C.F.

    1996-01-01

    Dr Cornelis Beets, internationally renowned specialist of Indonesian Cainozoic molluscs, died on the 28th of July 1995. Born April 25, 1916, he read geology at Leiden University and obtained his PhD in 1941 on a geological study of the Turin Hills (Italy). When working on his PhD, he had already

  8. Geology of uranium vein-deposits in France; Geologie des gites uraniferes et filoniens en France

    Energy Technology Data Exchange (ETDEWEB)

    Sarcia, J A; Carrat, J; Poughon, A; Sanselme, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    This paper gives an outline of the characteristics of the main uranium vein deposits in France; it underlines the structural, petrographic and metallogenic similarities of these deposits. (author) [French] La note presente est un expose des caracteres generaux des principaux gites uraniferes filoniens de France; elle insiste sur les similitudes structurales, petrographiques et metallogeniques de ces gisements. (auteur)

  9. Geologie study off gravels of the Agua Fria River, Phoenix, AZ

    Science.gov (United States)

    Langer, W.H.; Dewitt, E.; Adams, D.T.; O'Briens, T.

    2010-01-01

    The annual consumption of sand and gravel aggregate in 2006 in the Phoenix, AZ metropolitan area was about 76 Mt (84 million st) (USGS, 2009), or about 18 t (20 st) per capita. Quaternary alluvial deposits in the modern stream channel of the Agua Fria River west of Phoenix are mined and processed to provide some of this aggregate to the greater Phoenix area. The Agua Fria drainage basin (Fig. 1) is characterized by rugged mountains with high elevations and steep stream gradients in the north, and by broad alluvial filled basins separated by elongated faultblock mountain ranges in the south. The Agua Fria River, the basin’s main drainage, flows south from Prescott, AZ and west of Phoenix to the Gila River. The Waddel Dam impounds Lake Pleasant and greatly limits the flow of the Agua Fria River south of the lake. The southern portion of the watershed, south of Lake Pleasant, opens out into a broad valley where the river flows through urban and agricultural lands to its confluence with the Gila River, a tributary of the Colorado River.

  10. The gem collection of the Rijksmuseum van Geologie en Mineralogie of Leiden The Peridots

    NARCIS (Netherlands)

    Zwaan, P.C.

    1957-01-01

    The peridots in the gem collection of our Museum were acquired a long time ago (part of them were from the collection of King William I of the Netherlands). We should be sceptical about data on the origin of this material. Firstly we do not generally know whether the stones were bought or received

  11. Some unusual gemstones in the collection of the Rijksmuseum van Geologie en Mineralogie of Leiden

    NARCIS (Netherlands)

    Zwaan, P.C.

    1955-01-01

    Our Museum can take pride in a very valuable gem collection for, besides the numerous specimens which were gathered by King William I of the Netherlands a great many of the more unusual stones are to be found in it. Especially since World War II the Museum has acquired many interesting and important

  12. Zur Geologie des Kelkit Çay-Oberlaufs Südwestlich von Şiran (Nordostanatolien

    Directory of Open Access Journals (Sweden)

    Karl NEBERT

    1964-06-01

    Full Text Available The region situated east of Berdiga Dağ is built up by Mesozoic and Tertiary Sediments. The Mesozoic sequence begins with Lias and ends with Upper Cretaceous. During the Laramic orogenetic phase this sequence was folded with E-W striking axes. At the same time, granitic magma intruded in diapir - like fashion into the anticlines. The folding is accompanied by upthrusts and gravitative gliding. An angular disconformity separates Middle Eocene from the underlying Mesozoic strata. The Eocene sequence is mainly represented by clastic sediments and is penetrated by basic volcanics. Tilting of the Eocene strata was caused by Post - Eocene faulting.

  13. Iminoéthers-1 3 cycliques : chimie et applications dans le domaine des additifs pétroliers et des matériaux organiques Cyclic 1,3-Iminoethers: Chemistry and Applications in the Field of Petroleum Additives and Organic Materials

    Directory of Open Access Journals (Sweden)

    Le Perchec P.

    2006-11-01

    Full Text Available Cet article est consacré aux iminoéthers-1,3 cycliques les plus courants : les oxazines-1,3 et oxazolines-1,3. La première partie rappelle les synthèses de ces composés et quelques aspects récents de leur chimie : réactions d'hydrolyse, réactions de déprotonation avec ouverture de cycle, réactions des organométalliques, réactions d'addition des nucléophiles en positions 2 et 5, des sels d'iminoéthers correspondants, propriétés complexantes vis-à-vis des métaux, réactions d'aminolyse et formation de structures tensioactives, enfin polymérisations et copolymérisations cationiques. La seconde partie est consacrée à l'étude des travaux qui traitent des applications. En ce qui concerne le domaine des additifs pétroliers, on s'intéresse à la stabilité du cycle oxazoline et à son caractère polaire. Les dérivés tensioactifs dérivés d'oxazoline portant des chaînes hydrocarbonées ont été revendiqués comme additifs dispersants et multifonctionnels pour les carburants et les lubrifiants. De nombreuses formulations (dispersants, antioxydants antirouilles, antiusures, extrême pressions, réducteurs de frictions. . . ont été proposées. Certains dérivés d'hydroxyméthyl oxazolines présentent des propriétés lubrifiantes et d'autres ont un intérêt dans les formulations de boues de forage. En ce qui concerne le domaine des matériaux, on s'intéresse à la réactivité du cycle oxazoline pour réaliser soit des extensions de chaînes des thermoplastiques, soit des réticulations pour des applications de peintures et revêtements. Les homopolymères d'oxazoline qui ont un caractère polaire très marqué peuvent trouver des applications comme promoteur d'adhésion, ou tensioactifs pour les polymérisations en émulsion. Enfin, l'utilisation d'oxazolines stables a été revendiquée dans des formulations de vernis d'émaillage. This article deals with the most common cyclic 1,3-iminoethers, i. e. 1,3-oxazines and 1

  14. Underwater search of ancient Dwarka in Okhamandal (Archeologie sous-marine de l'ancienne Dwarka dans l'Okhamandal)

    Digital Repository Service at National Institute of Oceanography (India)

    Gaur, A.S.

    , ailleurs rocheux et escarpi, ce qui fait que les ancres se rompent ou dirivent sur les fonds. D De son cat&, Ptolimie mentionne Barake comme une ile dans le golfe de Kanthi, qui a tti identifit comme le golfe de Kachchh. I1 est donc fort pro- bable que...

  15. Archeologie a poznání moravských a slezských měst

    Czech Academy of Sciences Publication Activity Database

    Procházka, Rudolf

    2007-01-01

    Roč. 32, - (2007), s. 37-80 ISSN 0231-5823. [Medzinárodná konferencia archeológie stredoveku s hlavným zameraním archeológia stredovekého mesta /38./. Bardejov-Zlaté, 18.09.2006-22.09.2006] R&D Projects: GA ČR GA404/07/1513 Institutional research plan: CEZ:AV0Z80010507 Keywords : Moravia, Silesia * cities * archaeology * spatial development and structure Subject RIV: AC - Archeology, Anthropology, Ethnology

  16. Důl Jeroným v Čisté, geografie, geologie, historie, současnost

    Czech Academy of Sciences Publication Activity Database

    Kořínek, R.; Žůrek, P.; Kukutsch, Radovan

    2012-01-01

    Roč. 2, č. 2 (2012), s. 20-22 ISSN 1803-7534 R&D Projects: GA ČR GA105/09/0089 Institutional support: RVO:68145535 Keywords : Jeroným Mine in Čistá * stability * geomechanical monitoring * old mine workings Subject RIV: DH - Mining, incl. Coal Mining

  17. Kwartaire Bovidae van Nederland. De schedels en hoornpitten, welke zich bevinden in het Rijksmuseum van Geologie te Leiden

    NARCIS (Netherlands)

    Vlerk, van der I.M.

    1942-01-01

    The plates I—XI contain illustrations of all the skulls and horn-cores of Bovidae from the Quaternary of the Netherlands, brought together in the National Museum of Geology at Leyden, Holland. They were all photographed with the occiputs vertical or what is thought to be vertical. They are described

  18. Vliv lokální geologie na seizmickou odezvu povrchu horninového prostředí

    Czech Academy of Sciences Publication Activity Database

    Hrubešová, E.; Kaláb, Zdeněk

    2009-01-01

    Roč. 9, č. 1 (2009), s. 65-70 ISSN 1213-1962 R&D Projects: GA ČR GA105/07/0878 Institutional research plan: CEZ:AV0Z30860518 Keywords : local geological conditions * seismic response * Plaxis 2D Subject RIV: DC - Siesmology, Volcanology, Earth Structure www.fast.vsb.cz

  19. Výborné divadlo jako hezký film aneb Archeologie filmových Hrátek s čertem

    Czech Academy of Sciences Publication Activity Database

    Merenus, Aleš

    2016-01-01

    Roč. 28, č. 2 (2016), s. 77-103 ISSN 0862-397X Institutional support: RVO:68378068 Keywords : Czech drama * Drda, Jan * Mach, Josef * Brdečka, Jiří * film adaptation * Hrátky s čertem (Playing with the Devil) * fairy tales Subject RIV: AJ - Letters, Mass-media, Audiovision

  20. Archeologie Pobeskydí (K nové polské práci o Těšínsku)

    Czech Academy of Sciences Publication Activity Database

    Janák, V.; Kouřil, Pavel

    2001-01-01

    Roč. 53, č. 2 (2001), s. 372-386 ISSN 0323-1267 Institutional research plan: CEZ:AV0Z8001916 Keywords : the Těšín region * primeval times * the Middle Age s Subject RIV: AC - Archeology, Anthropology, Ethnology

  1. K estetickému myšlení Roberta Kalivody. Kapitola z archeologie českého marxismu

    Czech Academy of Sciences Publication Activity Database

    Kanda, Roman

    2014-01-01

    Roč. 62, č. 4 (2014), s. 527-548 ISSN 0009-0468 Institutional support: RVO:68378068 Keywords : Kalivoda, Robert * aesthetics * Marxism * structuralism * dialectics * ideology Subject RIV: AJ - Letters, Mass-media, Audiovision

  2. Neústupná archeologie. S Evženem Neustupným o jeho životě v archeologii

    Czech Academy of Sciences Publication Activity Database

    Kuna, Martin

    2013-01-01

    Roč. 65, č. 2 (2013), s. 405-422 ISSN 0323-1267 Institutional support: RVO:67985912 Keywords : archaeological paradigms * processual archaeology * 14C-dating * history of archaeology * education in archaeology Subject RIV: AC - Archeology, Anthropology, Ethnology

  3. Study of catalytic phenomena in radiation chemistry; Etude des phenomenes catalytiques en chimie des radiations

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-01-01

    Two phenomena have been studied: the action of {gamma} rays from radio-cobalt on the adsorption and catalytic properties of ZnO and NiO in. relationship with the heterogeneous oxidation of CO, and the homogeneous catalysis by OsO{sub 4} of the oxidation of various aqueous phase solutes by the same radiation. The prior irradiation of ZnO and of NiO does not modify their catalytic activity but generally increases the adsorption energy of -the gases CO and O{sub 2}. The influence of the radiations appears to be connected with the presence of traces of water on ZnO and of an excess of oxygen on NiO. Osmium tetroxide which is not degraded by irradiation in acid solution, accelerates the radiolytic oxidation of certain compounds (Te{sup IV}, Pt{sup 11}, As{sup 111}) in the presence of oxygen, as a result of its sensitizing effect on the oxidation by H{sub 2}O{sub 2}. In the case of phosphites on the other hand, OsO{sub 4} has a protecting action under certain conditions of acidity and may suppress entirely the chain reaction which characterizes the oxidation of this solute by{gamma} rays. A general mechanism is proposed for these phenomena. The rate constant for the OsO{sub 4} + HO{sub 2} reaction is calculated to be 5.7 x 10{sup 5} l.mol{sup -1}. sec{sup -1}. (author) [French] Deux phenomenes ont ete etudies: l'action des rayons {gamma} du radio-cobalt sur les proprietes adsorptives et catalytiques de ZnO et NiO en relation avec l'oxydation heterogene de CO et la catalyse homogene par OsO{sub 4} de l'oxydation de divers solutes en phase aqueuse par ce meme rayonnement. L'irradiation prealable de ZnO et de NiO n'a pas modifie leur activite catalytique, mais a generalement accru l'energie d'adsorption des gaz CO et O{sub 2}. L'influence des radiations semble liee a la presence de traces d'eau sur ZnO et d'un exces d'oxygene sur NiO. Le tetroxyde d'osmium qui n'est pas altere par le rayonnement en solution acide, accelere l'oxydation radiolytique de certains composes. (Te{sup IV}, Pt{sup 11} et As{sup 111}) en la presence d'oxygene, par suite de son effet sensibilisateur sur l'oxydation par H{sub 2}O{sub 2}. Dans le cas des phosphites, par contre, OsO{sub 4} exerce une action protectrice dans certaines conditions d'acidite, en conduisant eventuellement a la suppression, de la reaction en chaine qui caracterisa l'oxydation de ce solute par les rayons {gamma}. Un mecanisme general de ces phenomenes est propose. La constante de vitesse de la reaction OsO{sub 4} + HO{sub 2} est evalue a 5,7.10{sup 5} I.mol{sup -1} s{sup -1}. (auteur)

  4. Combustion chemistry and formation of pollutants; Chimie de la combustion et formation des polluants

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-31

    This book of proceedings reports on 7 papers on combustion chemistry and formation of pollutants presented during the workshop organized by the `Combustion and Flames` section of the French society of thermal engineers. The chemistry of combustion is analyzed in various situations such as: turbojet engines, spark ignition engines, industrial burners, gas turbines etc... Numerical simulation is used to understand the physico-chemical processes involved in combustion, to describe the kinetics of oxidation, combustion and flame propagation, and to predict the formation of pollutants. (J.S.)

  5. Industrial applications of radiation chemistry; Perspectives industrielles de la chimie sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Puig, Jean Rene [Commissariat a l' energie atomique et aux energies alternatives - CEA, Service de chimie-physique, CEN de Saclay (France)

    1959-07-01

    The status of industrial applications of radiation chemistry as it stands 6 months after the second Geneva international conference is described. The main features of the interaction of ionizing radiations with matter are briefly stated and a review is made of the best studied and the more promising systems of radiation chemistry. The fields of organics, plastics, heterogeneous catalysis are emphasized. Economies of radiation production and utilization are discussed. Reprint of a paper published in Industries atomiques - no. 5-6, 1959.

  6. Départetnent dc Chimie, Faculté des Sciences et Techniques,

    African Journals Online (AJOL)

    The electrochemical properties of qninones make them a promising class of compounds to ... in order to investigate the possibility to use it in manufacturing batteries [4]. ... Figures I and 2 show the dependence of the peak current and the peak ...

  7. 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)

  8. Study of catalytic phenomena in radiation chemistry; Etude des phenomenes catalytiques en chimie des radiations

    Energy Technology Data Exchange (ETDEWEB)

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

    1965-01-01

    Two phenomena have been studied: the action of {gamma} rays from radio-cobalt on the adsorption and catalytic properties of ZnO and NiO in. relationship with the heterogeneous oxidation of CO, and the homogeneous catalysis by OsO{sub 4} of the oxidation of various aqueous phase solutes by the same radiation. The prior irradiation of ZnO and of NiO does not modify their catalytic activity but generally increases the adsorption energy of -the gases CO and O{sub 2}. The influence of the radiations appears to be connected with the presence of traces of water on ZnO and of an excess of oxygen on NiO. Osmium tetroxide which is not degraded by irradiation in acid solution, accelerates the radiolytic oxidation of certain compounds (Te{sup IV}, Pt{sup 11}, As{sup 111}) in the presence of oxygen, as a result of its sensitizing effect on the oxidation by H{sub 2}O{sub 2}. In the case of phosphites on the other hand, OsO{sub 4} has a protecting action under certain conditions of acidity and may suppress entirely the chain reaction which characterizes the oxidation of this solute by{gamma} rays. A general mechanism is proposed for these phenomena. The rate constant for the OsO{sub 4} + HO{sub 2} reaction is calculated to be 5.7 x 10{sup 5} l.mol{sup -1}. sec{sup -1}. (author) [French] Deux phenomenes ont ete etudies: l'action des rayons {gamma} du radio-cobalt sur les proprietes adsorptives et catalytiques de ZnO et NiO en relation avec l'oxydation heterogene de CO et la catalyse homogene par OsO{sub 4} de l'oxydation de divers solutes en phase aqueuse par ce meme rayonnement. L'irradiation prealable de ZnO et de NiO n'a pas modifie leur activite catalytique, mais a generalement accru l'energie d'adsorption des gaz CO et O{sub 2}. L'influence des radiations semble liee a la presence de traces d'eau sur ZnO et d'un exces d'oxygene sur NiO. Le tetroxyde d'osmium qui n'est pas altere par le rayonnement en solution acide, accelere l'oxydation radiolytique de certains composes. (Te{sup IV}, Pt{sup 11} et As{sup 111}) en la presence d'oxygene, par suite de son effet sensibilisateur sur l'oxydation par H{sub 2}O{sub 2}. Dans le cas des phosphites, par contre, OsO{sub 4} exerce une action protectrice dans certaines conditions d'acidite, en conduisant eventuellement a la suppression, de la reaction en chaine qui caracterisa l'oxydation de ce solute par les rayons {gamma}. Un mecanisme general de ces phenomenes est propose. La constante de vitesse de la reaction OsO{sub 4} + HO{sub 2} est evalue a 5,7.10{sup 5} I.mol{sup -1} s{sup -1}. (auteur)

  9. Installation for analytic chemistry under irradiation; Installation de chimie analytique sous rayonnement

    Energy Technology Data Exchange (ETDEWEB)

    Fradin, J; Azoeuf, P; Guillon, A [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1966-07-01

    An installation has been set up for carrying out manipulations and chemical analyses on radioactive products. It is completely remote-controlled and is of linear shape, 15 metres long; it is made up of three zones: - an active zone containing the apparatus, - a rear zone giving access to the active zone, - a forward zone independent of the two others and completely protected from which the remote-control of the apparatus is effected. The whole assembly has been designed so that each apparatus corresponding to an analytical technique is set up in a sealed enclosure. The sealed enclosures are interconnected by a conveyor. After three years operation, a critical review is now made of the installation. (authors) [French] L'installation a ete realisee pour effectuer des manipulations et des analyses chimiques sur des produits radioactifs. Elle est totalement telecommandee et se presente sous une forme lineaire de 15 metres de longueur et comporte trois zones: - une zone active d'appareillage, - une zone arriere d'intervention, - une zone avant independante des deux premieres et totalement protegee, ou s'operent les telecommandes de l'appareillage. L'ensemble a ete concu de facon a ce que chaque appareillage correspondant a une technique d'analyse soit implante dans une enceinte etanche. Les enceintes etanches sont reliees entre elles par un convoyeur. Apres trois annees de fonctionnement nous faisons le bilan et les critiques de l'installation. (auteurs)

  10. Laboratoire de Chimie Bactérienne C.N.R.S., Marsielle, France.

    Science.gov (United States)

    Chippaux, M; Giudici, D; Abou-Jaoudé, A; Casse, F; Pascal, M C

    1978-04-06

    Mutants of E. coli, completely devoid of nitrite reductase activity with glucose or formate as donor were studied. Biochemical analysis indicates that they are simultaneously affected in nitrate reductase, nitrite reductase, fumarate reductase and hydrogenase activities as well as in cytochrome C552 biosynthesis. The use of an antiserum specific for nitrate reductase shows that the nitrate reductase protein is probably missing. A single mutation is responsible for this phenotype: the gene affected, nir R, is located close to tyr R i.e. at 29 min on the chromosomal map.

  11. Chemistry 30: Grade 12 Diploma Examination = Chimie 30: Examen en vue du diplome 12 annee.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton. Student Evaluation Branch.

    This document, in both French and English versions, is the Chemistry 30 Grade 12 Diploma Examination from Alberta Education. It is a 2.5 hour closed-book examination consisting of 44 multiple-choice and 12 numerical-response questions of equal value that are worth 70% of the examination, and 2 written-response questions of equal value worth 30% of…

  12. Raw materials for the energy supply of the future. Geology, markets, environmental influences; Rohstoffe fuer die Energieversorgung der Zukunft. Geologie, Maerkte, Umwelteinfluesse

    Energy Technology Data Exchange (ETDEWEB)

    Hagelueken, Christian [Umicore, Hanau-Wolfgang (Germany); Thauer, Rudolf K. [Max-Planck-Institut fuer Terrestrische Mikrobiologie, Marburg (Germany); Buchholz, Peter [Bundesanstalt fuer Geowissenschaften und Rohstoffe, Hannover (Germany). Deutsche Rohstoffagentur; Herzig, Peter [GEOMAR Helmholtz-Zentrum fuer Ozeanforschung Kiel (Germany); Gutzmer, Jens [Technische Univ. Bergakademie Freiberg (Germany); Helmholtz-Institut Freiberg fuer Ressourcentechnologie (Germany); Littke, Ralf [Rheinisch-Westfaelische Technische Hochschule (RWTH), Aachen (Germany); Angerer, Gerhard; Wellmer, Friedrich-Wilhelm

    2015-11-15

    More and more metals are needed to expand modern energy technologies, but we can not completely dispense with fossil raw materials and biomass in the near future either. Are the incidence of the conversion of energy sources sufficient? The analysis of the academy project ''Energy Systems of the Future'' (ESYS) comes to the conclusion that geologically enough raw materials are available. The challenge, however, is to make the supply safe, affordable and environmentally and socially compatible. The analysis explains the mechanisms of action on the global commodity markets and identifies supply risks. These include, for example, sudden demand on the international markets as well as the unequal distribution of the world's raw material reserves. This is followed by the analysis approaches, in order to recognize warning signals for potential raw material bottlenecks in time, to develop evasive strategies and to secure the raw material supply for the energy turnarounds. For example, the expansion of recycling can help to reduce the dependence on metal imports. In mining, on the other hand, innovative technologies have to be developed in order to improve the exploration and utilization of the deposits. By establishing binding environmental and social standards, the extraction of raw materials could also become more sustainable. The analysis also highlights the importance of bioenergy and fossil raw materials, such as oil and natural gas, for energy generation. The authors describe the advantages and disadvantages of these energy carriers and the measures that can be used to reduce environmental pollution such as greenhouse gas emissions. [German] Fuer den Ausbau moderner Energietechnologien werden immer mehr Metalle benoetigt, doch auch auf fossile Rohstoffe und Biomasse koennen wir in naher Zukunft nicht vollstaendig verzichten. Reichen die Vorkommen zur Umsetzung der Energiewende aus? Die Analyse des Akademienprojekts ''Energiesysteme der Zukunft'' (ESYS) kommt zu dem Ergebnis, dass geologisch gesehen genuegend Rohstoffe zur Verfuegung stehen. Die Herausforderung besteht jedoch darin, die Versorgung sicher, bezahlbar sowie umwelt- und sozialvertraeglich zu gestalten. Die Analyse erlaeutert die Wirkmechanismen auf den globalen Rohstoffmaerkten und identifiziert Versorgungsrisiken. Dazu zaehlen zum Beispiel ploetzliche Nachfrageschuebe auf den internationalen Maerkten sowie die ungleiche Verteilung der Rohstoffvorkommen auf der Welt. Daran anschliessend liefert die Analyse Ansaetze, um Warnsignale fuer potenzielle Rohstoffengpaesse rechtzeitig zu erkennen, Ausweichstrategien zu entwickeln und die Rohstoffversorgung fuer die Energiewende zu sichern. So kann zum Beispiel der Ausbau des Recyclings dazu beitragen, die Abhaengigkeit von Metallimporten zu reduzieren. Im Bergbau wiederum gilt es, innovative Technologien zu entwickeln, um die Erkundung und Nutzung der Lagerstaetten zu verbessern. Durch die Festlegung verbindlicher Umwelt- und Sozialstandards koennte die Rohstoffgewinnung darueber hinaus nachhaltiger erfolgen. Die Analyse beleuchtet ausserdem die Bedeutung der Bioenergie und fossiler Rohstoffe wie Erdoel und Erdgas fuer die Energiewende. Die Autoren beschreiben, welche Vor- und Nachteile diese Energietraeger mit sich bringen und durch welche Massnahmen Umweltbelastungen wie Treibhausgasemissionen reduziert werden koennen.

  13. Geologie des Ida ou Zal (Maroc) Stratigraphie,petrographie et tectonique de la partie SW du bloc occidental du massif ancien du Haut Atlas

    NARCIS (Netherlands)

    Koning, de G.

    1957-01-01

    The present publication deals with the geology of the area known as the Ida ou Zal, situated principally in the Palaeozoic of the Western High Atlas mountains in Morocco. The area extends grosso modo between Argana (N), Sidi Idir (E), Menizla (S) and Tirkou (W); its centre lies at 34°10 N—12°65 W.

  14. 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)

  15. Geology and uranium occurrences in the Forez tertiary plain (in the French 'Massif Central'); Geologie et mineralisations uraniferes de la plaine tertiaire du Forez (Massif Central francais)

    Energy Technology Data Exchange (ETDEWEB)

    Duclos, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses - 92 (France). Centre d' Etudes Nucleaires

    1967-01-01

    In the first part, the observations made during the geological survey of the Forez Tertiary plain (in the French 'Massif Central') are recalled. Then, using various methods, the author lists the formations according to chronology. Finally, a reconstitution of the geological history of this subsidence basin is attempted. In the second part, the occurrence of 17 uranium bearing geochemical anomalies is commented upon. Each of these various anomalies is given a place on the stratigraphic scale. This enables the author to put the successive phases of uranium deposition into their proper perspective in the history of the plain. In conclusion, the author points out the usefulness of these uraniferous geochemical anomalies. (author) [French] Dans la premiere partie, l'auteur rappelle les observations faites au cours de l'etude geologique de la plaine tertiaire du Forez (Massif Central francais). Puis se servant de differentes methodes, il etablit une chronologie des formations. Enfin, il termine par un essai de reconstitution de l'histoire geologique de ce bassin de subsidence. Dans la deuxieme partie, il commente la decouverte de 17 anomalies geochimiques uraniferes. Il situe ces differentes anomalies dans la serie stratigraphique. Ceci lui permet de replacer les depots successifs de l'uranium dans l'histoire de la plaine. Enfin, il indique l'interet de ces anomalies geochimiques uraniferes. (auteur)

  16. Landschappen in 3D : 3D-printen van hoge resolutie terreinmodellen met overlays van geologie en orthofoto's met ArcGIS en Blender

    NARCIS (Netherlands)

    Magnússon, R.Í.; de Boer, W.M.; Seijmonsbergen, A.C.

    2016-01-01

    Detection And Ranging), een relatief nieuwe remote sensing-techniek, worden steeds gedetailleerdere digitale hoogtemodellen gemaakt, waardoor het aardoppervlak in zeer hoog detail in 3D kan worden weergegeven. 3D-printen biedt hierop een uitstekende aanvulling, doordat het hiermee niet nodig is 3D

  17. Semiannual Report of the Chemistry Department, June--November 1966; Rapport semestriel du departement de chimie, juin--novembre 1966

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1967-07-01

    This semiannual report of the Chemistry Department of the Cea of Fontenay-aux Roses, presents in its first part researches on the chemical analysis, the treatment of fairly and slightly active effluents, the uranium treatment, studies on electrometallurgy, studies on corrosion and studies on filtration and elimination on sea water of hard compounds. The second part is devoted to the study of aqueous reprocessing of irradiated fuels (laboratory and pilot plant), anhydrous reprocessing, actinides elements isotopes preparation and study, fission products concentrated solution vitrification study and fundamental studies on acid-base properties. (A.L.B.)

  18. The ozone hole and the 1995 Nobel prize in chemistry; Trou d`ozone et Prix Nobel 1995 de chimie

    Energy Technology Data Exchange (ETDEWEB)

    Berger, A. [Universite Catholique de Louvain (UCL), Louvain-la-Neuve (Belgium). Inst. d`Astronomie et de Geophysique G. Lemaitre

    1996-03-01

    To mark to award of the 1995 Nobel Prize in chemistry to three world renowned atmospheric chemists, this paper recalls the history of scientific progress in stratospheric ozone chemistry. Then it summarizes current knowledge of ozone-layer depletion and its impact on climate, vegetation and human health. (author). 21 refs., 12 figs.

  19. Analyse didactique de l'enseignement-apprentissage de la chimie organique jusqu'à bac+2 pour envisager sa restructuration

    OpenAIRE

    Lafarge, David

    2010-01-01

    Organic chemistry is often considered as a difficult subject to teach and to learn. Students tend to see memorisation as a priority, and this is detrimental to developing reasoning in relation to models of chemical reactivity. The aim of our research was to provide knowledge that would be useful to improve the teaching and learning of organic chemistry in the first two years of a higher education course. We focussed our study on 1/ the effects of the way this teaching is currently structured ...

  20. Le dictionnaire de chimie en lingála pour les élèves de Kinshasa

    African Journals Online (AJOL)

    Résumé: Pour réaliser un dictionnaire spécialisé dans une langue bien documentée, le lexico- graphe dépouille les documents disponibles, il en extrait des termes candidats et, éventuellement, leurs définitions et des exemples pertinents. Cette approche n'est pas adaptée pour des langues dont les documents ...

  1. Application de la methode de diffusion de la lumiere a quelques problemes de physico-chimie macromoleculaire

    NARCIS (Netherlands)

    Kunst, Egbert Diederik

    1950-01-01

    De onderzoekingen van Debije, Zimm en anderen hebben aangetoond, dat het mogelijk is met behulp van de lichtverstrooiing de eigenschappen van moleculen in oplossing te bestuderen, en meer in het bijzonder hun molecuulgewicht en afmetingen te bepalen. Het leek dus interessant enige toepassingen van

  2. Grade 12 Diploma Examination: Chemistry 30. June 1988 = Examen en vue du Diplome Douzieme Annee: Chimie 30. Juin 1988.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Chemistry 30 is a 12th-grade chemistry course for students in Alberta, Canada. This document is the final test for the course. Intended for administration during June, 1988, it contains 56 multiple-choice questions and three written-response questions. Two-and-one-half hours are allowed for completing the test. No answer key is included since…

  3. Grade 12 Diploma Examination: Chemistry 30. June 1986. = Examen en vue du Diplome Douzieme Annee: Chimie 30. Juin 1986.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Chemistry 30 is a twelfth-grade chemistry course for students in Alberta, Canada. This document is a final test for the course. Both English and French versions of the test are provided. Intended for administration during June 1986, it contains 56 multiple-choice questions and three written-response problems. Two-and-one-half hours are allowed for…

  4. Grade 12 Diploma Examination: Chemistry 30. January 1989 = Examen en vue du diplome douzieme annee: Chimie 30. Janvier 1989.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Chemistry 30 is a 12th-grade science course for students in Alberta, Canada. This document is the final test for the course. Intended for administration during January 1989, it contains 56 multiple-choice questions and three written-response questions. Two and one-half hours are allowed for completing the test. No answer key is included since…

  5. Grade 12 Diploma Examination: Chemistry 30. June 1989 = Examen en vue du diplome douzieme annee: Chimie 30. Juin 1989.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Chemistry 30 is a 12th-grade science course for students in Alberta, Canada. This document is the final test for the course. Intended for administration during June 1989, it contains 56 multiple-choice questions and 3 written-response questions. Two-and-one-half hours are allowed for completing the test. No answer key is included since scoring is…

  6. Grade 12 Diploma Examination: Chemistry 30. January 1988 = Examen en vue du diplome douzieme annee: Chimie 30. Janvier 1988.

    Science.gov (United States)

    Alberta Dept. of Education, Edmonton.

    Chemistry 30 is a 12th-grade science course for students in Alberta, Canada. This document is the final test for the course. Intended for administration during January 1988, it contains 56 multiple-choice questions and three written-response questions. Two-and-one-half hours are allowed for completing the test. No answer key is included since…

  7. TIC et enseignement de la Chimie : au-delà des discours, quels dispositifs d’enseignement pour quels apprentissages?

    Directory of Open Access Journals (Sweden)

    MARIE-THÉRÈSE SALIBA

    2012-12-01

    Full Text Available In this research we suggest to take advantage of the opportunities offered by the new information and communication technologies (NICT. This new techno-scientific process of investigation will be realized via a laboratory of CAE (Computer assisted experimentations where the computer is the learning tool that seeks in real time concrete observations. Experimental know- how, and the using of abstract representations to solve problems. To do this, we have introduced innovated courses in Didactics based on ICT/CAE in our Masters programs in the Holy Spirit University of Kaslik (USEK. These courses are intended for initial and continuous training of our student-teachers in mathematics and science and technology. Subsequently, our student-teachers will use CAE with their students in high schools for teaching chemistry to test and validate the functional aspect of the environment CAE proposed. The educational validation of this paradigm will be based on the confrontation between a priori analysis and subsequent findings to measure the gap of understanding that students have acquired.

  8. Contribution to the solution chemistry of uranium (6); Contribution a la chimie de l'uranium (6) en solution

    Energy Technology Data Exchange (ETDEWEB)

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

    1969-07-01

    In the first part, a potentiometric study of the complexes formed by the uranyl ion with the hydroxy ligand has been performed. evidence has been presented for the existence of the following complexes with their respective stability constants (determined at 25 deg. C in 0.1 M ClO{sub 4}Na medium): UO{sub 2}OH, logbeta{sub 1,-1}= -4.39; (UO{sub 2}){sub 2}OH, logbeta{sub 2,-1} = -2.22; (UO{sub 2}){sub 2} (OH){sub 2}, logbeta{sub 2,-2} = -6.09; (UO{sub 2}){sub 3}(OH){sub 5}, log{sub 3,-5}) = -15.64; (UO{sub 2}){sub 3} (OH){sub 7}, logbeta{sub 3,-7} = -24.03. In the second part, a similar investigation has been undertaken on the complex formed by the uranyl ion with carbonate and/or hydroxyl ligands; the latter appearing in neutral or acid media. Evidence has been presented for the existence of the following complexes and their respective stability constants, all determined at 25 deg. C in 0.1 M ClO{sub 4}Na medium: UO{sub 2}(CO{sub 3}){sub 3}, logbeta{sub 3,1,0} = 21.57. UO{sub 2}(CO{sub 3}){sub 2}, logbeta{sub 2,1,0} = 16.16; UO{sub 2}CO{sub 3}OH, logbeta{sub 1,1,-1} 4.10. In the third part, the solid phases of the system (NO{sub 3}){sub 2}UO{sub 2} - NaOH - H{sub 2}O have been investigated by the method of the residues. In this system the following compounds have been identified: U{sub 2}O{sub 7}Na{sub 2} and (NO{sub 3}){sub 2} U{sub 6}O{sub 17} in slightly acid medium. Finally, the solid phases of the system (NO{sub 3}){sub 2}UO{sub 2} - CO{sub 3}Na{sub 2} - H{sub 2}O have been investigated as before. The following compounds have been identified: CO{sub 3}UO{sub 2}, in slightly acid medium; an uranyl alkaline carbonate appearing in neutral medium with the formula (UO{sub 2}CO{sub 3}){sub 3} (NaOH){sub 2}, as well as the corresponding uranates. (author) [French] Dans la premiere partie, nous avons etudie par potentiometries les complexes formes par l'ion uranyl et le ligand hydroxyle. nous avons prouve l'existence des complexes suivants et nous avons determine leur constante de stabilite (a 25 deg. C et dans le milieu 0.1 M ClO{sub 4}Na): UO{sub 2}OH, logbeta{sub 1,-1} = -4.39; (UO{sub 2}){sub 2}OH, logbeta{sub 2,-1} = -2.22; (UO{sub 2}){sub 2} (OH){sub 2}, logbeta{sub 2,-2} = -6.09; (UO{sub 2}){sub 3} (OH){sub 5}, log{sub 3,-5}) = -15.64; (UO{sub 2}){sub 3} (OH){sub 7}, logbeta{sub 3,-7} = -24.03. Dans la deuxieme partie, nous avons etudie par potentiometrie les complexes formes par l'ion uranyle avec les ligands carbonate et hydroxyle, ces derniers apparaissant en milieu neutre ou acide. nous avons prouve l'existence des complexes suivants et nous avons determine leur constante de stabilite (a 25 deg. C et dans le mileu 0.1 M ClO{sub 4}Na): UO{sub 2}(CO{sub 3}){sub 3}, logbeta{sub 3,1,0} = 21.57. UO{sub 2}(CO{sub 3}){sub 2}, logbeta{sub 2,1,0} = 16.16; UO{sub 2}CO{sub 3}OH, logbeta{sub 1,1,-1} = 4.10. Dans la troisieme partie, nous avons etudie par la methode des restes de phases solides du sysreme (NO{sub 3}){sub 2} UO{sub 2} - NaOH - H{sub 2}O. Nous avons mis en evidence, les composes suivants: U{sub 2}O{sub 7}Na{sub 2}, en milieu alcalin; U{sub 6}O{sub 19}Na{sub 2}, en milieu neutre; U{sub 12}O{sub 37}Na{sub 2} et(NO{sub 3}){sub 2} U{sub 6}O{sub 17}, en milieu legerement acide. Enfin, dans la quatrieme partie, nous avons etudie par la methode des restes, les phases solides du systeme (NO{sub 3}){sub 2}UO{sub 2} - CO{sub 3}Na{sub 2} - H{sub 2}O. Nous avons mis en evidence, en plus des uranates, les deux composes suivants: CO{sub 3}UO{sub 2}, en milieu legerement acide; et un carbonate d'uranyle alcalin apparaissant en milieu neutre de formule brute (UO{sub 2}CO{sub 3}){sub 3}(NaOH){sub 2}. (auteur)

  9. Sídelní archeologie loveckých populací. K dynamice a populační kinetice mladého paleolitu ve středním Podunají

    Czech Academy of Sciences Publication Activity Database

    Svoboda, Jiří

    2006-01-01

    Roč. 47, - (2006), s. 13-31 ISSN 1211-7250 Institutional research plan: CEZ:AV0Z80010507 Keywords : Danubian region * central Europe * Neandertals * Modern Humans * Settlement archaeology * Population kinetics * Demography Subject RIV: AC - Archeology, Anthropology, Ethnology

  10. Liquid scintillators for radiocarbon dating in archaeology; Scintillateurs liquides pour l'evaluation de Page au moyen du radiocarbone en archeologie; Zhidkie stsintillyatory dlya radiouglerodnogo datirovaniya v arkheologii; Centelladores liquidos para la determinacion de edades con carbono-14 en arqueologia

    Energy Technology Data Exchange (ETDEWEB)

    Starik, I E; Rudenko, S I; Artem' ev, V V; Butomo, S V; Drozhzhin, V M; Romanova, E N

    1962-01-15

    A simple scintillator counter with one photomultiplier and no cooling is used for determining the absolute age of archaeological specimens by means of radiocarbon. Background is reduced by using a steel- and lead-laminated shield and amplitude pulse-height selection, and by making the detector from selected 'clean' materials. Ethyl benzene is synthesized from the carbon contained in the archaeological specimen. From 18 to 72 ml of liquid scintillator was used in the measurements, corresponding to the introduction of 3 - 12 g of carbon from the specimen. With 40 ml of scintillator the background-count speed and the contemporaneous carbon speed (without background) were respectively 23.5 and 37 counts/min and with 70 ml, 28 and 57 counts/ min. The statistical error of 48-h measurements of specimens 5500 yr old is respectively 65 and 35 yr with 40 and 70 ml of the scintillator. Archaeological specimens from various regions of the Soviet Union were measured. (author) [French] Pour determiner l'age absolu de specimens archeologiques au moyen du radiocarbone, on emploie un simple compteur a scintillations avec un seul photomultiplicateur sans refroidissement. On parvient a diminuer le bruit de fond en employant un ecran forme de lames d'acier et de plomb, en selectionnant les impulsions selon leur amplitude et en choisissant des matieres pour la construction du detecteur. A partir du carbone contenu dans le specimen archeologique, on obtient, par synthese, de l'ethylbenzene. Pour effectuer les mesures, on a utilise de 18 a 72 ml de scintillateur liquide, ce qui equivalait a l'introduction de 3 a 12 g de carbone provenant de l'echantillon. Pour une quantite de 40 ml de scintillateur, la vitesse de comptage du bruit de fond et celle de carbone contemporain (sans bruit de fond) etaient de 23,5 et 37 imp/min respectivement, et, pour 70 ml, de 28 et 57 imp/min. L'erreur statistique que comportent les mesures effectuees pendant 48 heures sur des echantillons vieux de 5500 ans represente, pour des quantites de 40 et 70 ml de scintillateur, 65 et 25 ans respectivement. Les auteurs ont effectue des mesures sur des specimens archeologiques provenant de diverses regions de l'URSS. (author) [Spanish] Con el objeto de determinar mediante carbono radiactivo la edad absoluta de muestras arqueologicas, los autores utilizan un contador de centelleo sencillo con un fotomultiplicador, sin refrigeracion. Consiguen reducir la actividad de fondo empleando un blindaje formado por laminas de acero y de plomo, procediendo a una seleccion de los impulsos segun su amplitud y construyendo el detector con materiales seleccionados y ''purificados''. A partir del carbono contenido en la muestra arqueologica, se sintetiza etil benceno. Para efectuar las mediciones, se han utilizado de 18 a 72 ml de centelleador liquido, cantidad que corresponde de 3 a 12 g de carbono en la muestra. Empleando 40 ml de centelleador, la velocidad de recuento de la actividad de fondo y la del carbono contemporaneo (sin fondo) fueron respectivamente de 23,5 y 37 impulsos/min; con 70 ml, estas velocidades fueron de 28 y 57 impulsos/min. El error estadistico correspondiente a mediciones de 48 horas de duracion de muestras de 5500 anos de edad asciende a 65 y 35 anos cuando se emplean 40 ml y 70 ml de centelleador, respectivamente. Se midieron muestras arqueologicas procedentes de diversas regiones de la Union Sovietica. (author) [Russian] Dlya opredeleniya absolyutnogo vozrasta arkheologicheskikh obraztsov po radiouglerodu ispol'zuetsya prostoj stsintillyatsionnyj schetchik s odnim fotoumnozhitelem bez okhlazhdeniya. Snizhenie fona dostigaetsya primeneniem zashchity iz sloev stali i svintsa, amplitudnoj selektsii impul'sov i vyborom ''chistykh'' materialov dlya izgotovleniya detektora. Iz ugleroda, soderzhashchegosya v arkheologicheskom obraztse, sinteziruetsya ehtilbenzol. Pri izmereniyakh ispol'zovalos' ot 18 do 72 ml zhidkogo stsintillyatora, chto sootvetstvovalo vvedeniyu ot 3 do 12 g ugleroda obraztsa. Dlya 40 ml stsintillyatora skorost' scheta fona i sovremennogo ugleroda (bez fona) byla ravna 23,5 i 37 imp/min, a dlya 70 ml - 28 i 57 imp/min, sootvetstvenno. Statisticheskaya oshibka 48 chasovykh izmerenij obraztsov vozrasta 5,5 tysyach let sostavlyaet dlya 40 i 70 ml stsintillyatora 65 i 35 let. Proizvedeny izmereniya arkheologicheskikh obraztsov iz razlichnykh rajonov SSSR. (author)

  11. Geology, geochemistry and {sup 40}K-{sup 40}Ar geochronometry of Miocene magmatism in Algiers area, Northern Algeria; La magmatisme miocene de l`Est Algerois, geologie, geochimie et geochronologie {sup 40}K-{sup 40}Ar

    Energy Technology Data Exchange (ETDEWEB)

    Belanteur, O; Ouabadi, A; Semroud, B; Megartsi, M H [Algiers Univ. (Algeria). Faculte des Sciences; Bellon, H; Maury, R C; Coutelle, A [Brest Univ., 29 (France); Fourcade, S [Rennes-1 Univ., 35 (France)

    1996-12-31

    Miocene magmatic rocks outcrop within a narrow coastal strip east of Algiers. They include basaltic and andesitic lava flows and intrusions (Dellys, Cap Djinet), the Thenia granodioritic plug and the dacitic to rhyolitic lavas and pyroclastic flows from Zemmouri El Bahri and El Kerma. Despite the effects of hydrothermal alteration, {sup 40}K-{sup 40}Ar ages coupled with micropalaeontological data lead to recognition of two emplacement events at 16-15 and 14-12 Ma, respectively. All the studied calc-alkaline to potassic calc-alkaline rocks are enriched in highly incompatible elements and display negative Nb anomalies. Acid magmas have a pronounced crustal imprint ({sup 87}Sr{sup 86}Sr{sub i} =3D 0.7082 to 0.7155; {delta}{sup 18}O =3D +9 to +13 per mill) which together with La/Nb ratios argues for the occurrence of upper crustal contamination processes. However, the Nb-depletion of the associated basalts suggest that the studied magmas derive from a mantle source which underwent subduction-related metasomatic enrichments prior to their Miocene emplacement. (authors). 13 refs., 3 figs., 2 tabs.

  12. Contribution to the geology of the Niari basin: sedimentology and metallogeny of the mining region; Contribution a la geologie du Bassin du Niari sedimentologie et metallogenie de la region miniere

    Energy Technology Data Exchange (ETDEWEB)

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

    1956-01-15

    This thesis is divided in two parts: a detailed petrographical and stratigraphical study of the upper layers of calcareous schist in Congo which lead to some sedimentological considerations, and a metallogenic study of the ores of Niari basin which lead to a theoretical description of the metallogeny in Congo. In the first part, after a brief description of the methods used, a petrographical survey of the rocks of the upper layers of calcareous schist of the Boko-Congo area is given as well as sedimentological conclusions and stratigraphical data. The studies and conclusions related to this limited area are extended to a region scale. A structural study and precised descriptions of this region lead to an attempt of tectonic explanation. In the second part, an inventory and description of known mineralisation points in the Niari basin are given and in particular the detailed descriptions of four deposits: La Grande-Mine, M'Passa, Diangala and Djenguile. The interpretations and conclusions are based on the study of the general characters of the mineralisation in Niari basin and its comparison with the mineralisation in Katanga (now Shaba region) and North Rhodesia (now Zambia). (M.P.)

  13. Geology and uranium occurrences in the Forez tertiary plain (in the French 'Massif Central'); Geologie et mineralisations uraniferes de la plaine tertiaire du Forez (Massif Central francais)

    Energy Technology Data Exchange (ETDEWEB)

    Duclos, P. [Commissariat a l' Energie Atomique, Fontenay-aux-Roses - 92 (France). Centre d' Etudes Nucleaires

    1967-01-01

    In the first part, the observations made during the geological survey of the Forez Tertiary plain (in the French 'Massif Central') are recalled. Then, using various methods, the author lists the formations according to chronology. Finally, a reconstitution of the geological history of this subsidence basin is attempted. In the second part, the occurrence of 17 uranium bearing geochemical anomalies is commented upon. Each of these various anomalies is given a place on the stratigraphic scale. This enables the author to put the successive phases of uranium deposition into their proper perspective in the history of the plain. In conclusion, the author points out the usefulness of these uraniferous geochemical anomalies. (author) [French] Dans la premiere partie, l'auteur rappelle les observations faites au cours de l'etude geologique de la plaine tertiaire du Forez (Massif Central francais). Puis se servant de differentes methodes, il etablit une chronologie des formations. Enfin, il termine par un essai de reconstitution de l'histoire geologique de ce bassin de subsidence. Dans la deuxieme partie, il commente la decouverte de 17 anomalies geochimiques uraniferes. Il situe ces differentes anomalies dans la serie stratigraphique. Ceci lui permet de replacer les depots successifs de l'uranium dans l'histoire de la plaine. Enfin, il indique l'interet de ces anomalies geochimiques uraniferes. (auteur)

  14. Contribution to the geology of the Niari basin: sedimentology and metallogeny of the mining region; Contribution a la geologie du Bassin du Niari sedimentologie et metallogenie de la region miniere

    Energy Technology Data Exchange (ETDEWEB)

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

    1956-01-15

    This thesis is divided in two parts: a detailed petrographical and stratigraphical study of the upper layers of calcareous schist in Congo which lead to some sedimentological considerations, and a metallogenic study of the ores of Niari basin which lead to a theoretical description of the metallogeny in Congo. In the first part, after a brief description of the methods used, a petrographical survey of the rocks of the upper layers of calcareous schist of the Boko-Congo area is given as well as sedimentological conclusions and stratigraphical data. The studies and conclusions related to this limited area are extended to a region scale. A structural study and precised descriptions of this region lead to an attempt of tectonic explanation. In the second part, an inventory and description of known mineralisation points in the Niari basin are given and in particular the detailed descriptions of four deposits: La Grande-Mine, M'Passa, Diangala and Djenguile. The interpretations and conclusions are based on the study of the general characters of the mineralisation in Niari basin and its comparison with the mineralisation in Katanga (now Shaba region) and North Rhodesia (now Zambia). (M.P.)

  15. Geologie et geochimie du fleuve, de l'estuaire et du golfe Saint-Laurent (Canada). [Geology and geochemistry of the river, estuarine, and gulf sections of the St. Lawrence

    Energy Technology Data Exchange (ETDEWEB)

    Couillard, D

    1982-07-01

    This article provides an outline of conditions of particulate material and sediments in the river, estuarine, and gulf sections of the St. Lawrence (Quebec, Canada). The concentration of solids in the river above lac St. Pierre varies between 4 and 10 mg/L, whereas downstream towards Quebec the concentrations rise to 30-50 mg/L. With the exception of the Sorel delta, this section of the river does not constitute a major sink of sedimentary materials, but the surface sediments of the river are enriched with phosphorus, polychlorinated biphenyls, copper, and lead. The portion immediately upstream from Ile d'Orleans is the interface of riverine water and salt water from the Gulf of St. Lawrence and at this point is a region of high concentrations of suspended solids (up to 300 mg/L). The process of sedimentation in the estuary is complicated by the coagulation of fine particles after contact with salt water. As a result, there is a zone of high sedimentation rates of fine particulates enriched in phosphorus, organic matter, and polychlorinated biphenyls in the area of Ile d'Orleans, making constant dredging necessary. Downstream from Ile d'Orleans is a decrease from 40-80 mg/L suspended solids to 1-2 mg/L in the Gulf of St. Lawrence.

  16. Geology, mining and prehistory in the Braunschweig area. Northern Harz margin, Asse, Elm-Lappwald, Peine-Salzgitter, Allertal. Geologie, Bergbau und Urgeschichte im Braunschweiger Land. Noerdliches Harzvorland, Asse, Elm-Lappwald, Peine-Salzgitter, Allertal

    Energy Technology Data Exchange (ETDEWEB)

    Look, E R; Goldberg, G; Kosmahl, W; Meyer, H J; Meyer, K D; Kolbe, H

    1986-01-01

    Even today, numerous rare geological formations are encountered which have been exposed either in a natural way, e.g. by erosion, or by man, e.g. in quarries and mines. This paper describes as comprehensively as possible the geology of this area and the use of its geological resources by man on the basis of an abundance of both recent and old exposures; some of which have been rediscovered and are still accessible. The comprehensive reference list gives the main geoscientific publications for this area.

  17. The largest Swiss diffusion storage system - Geology, petrophysics, hydro-geology and experience gained from the realisation of heat probes; Groesster saisonaler Diffusionsspeicher der Schweiz D4 in Root (LU): Geologie, Petrophysik, Hydrogeologie und Erfahrungen mit der Realisation des Sondenfeldes

    Energy Technology Data Exchange (ETDEWEB)

    Keller, B.

    2007-07-15

    This article takes a look at a large heat-diffusion storage system that is to be implemented in stages at a business and innovation centre in Root, near Lucerne in Switzerland. The aim is to meet 50 percent of energy needs using renewable energy. Apart from conventional oil and gas-fired systems, a combined heat and power (CHP) unit, heat and cold storage, a solar roof and photovoltaics, a seasonal underground diffusion storage system is used. This storage system is 'filled' with heat in summer from the roof and waste heat. It then functions in winter as a heat source. The system features two fields of 49, 160 metre-long heat probes that use a volume of 376,000 cubic metres of rock. The dimensioning of the rock-storage system was simulated using the PILESIM program and the first field was implemented in 2001. A geological overview is presented and the physical properties of the rock structures used are discussed. The temperature profile measured is presented and the precautions taken as a result of the possibility of meeting pockets of natural gas are discussed. Know-how gained from the implementation of the first probe field is discussed.

  18. Présentation de Paul Colonna

    OpenAIRE

    Corvol, Pierre

    2013-01-01

    Cher Collègue, Cher Paul Colonna, Il y a moins de vingt ans est apparue dans le monde une nouvelle chimie, la chimie verte. Cette chimie est une alternative à l’utilisation du carbone fossile et d’autres types d’énergie non renouvelables (gaz, charbon). La chimie traditionnelle à base de pétrole est certes performante, créative, compétitive, et répond bien à nos besoins, mais elle est aussi polluante et épuise les ressources de carbone fossile. La chimie verte se développe à côté de la chimie...

  19. Chimie organométallique des éléments f : vers de nouveaux développements : complexes cyanures des éléments f

    OpenAIRE

    Hervé, Alexandre

    2014-01-01

    The cyanide ligand is one of the most widely used ligands in coordination chemistry of d-transition metals. The low number of cyanide complexes of lanthanides and actinides incited us to develop this field for reactivity and theoretical aspects, and also for their potentially interesting physicochemical properties. In this Ph.D., we investigated the reactivity of [An(Cot)₂] (An = Th, U ; Cot = C₈H₈²⁻) and [Mf(N*)₃]ʲ˖ (j = 0, 1; Mf = Ce, U ; N* = ⁻N(SiMe₃)₂) precursors toward the cyanide ion. ...

  20. Concrete durability: physical chemistry of the water attack; Durabilite du beton: physico-chimie de l`alteration par l`eau

    Energy Technology Data Exchange (ETDEWEB)

    Faucon, P

    1997-01-22

    Cement paste constitutes an basic medium, thermodynamically stable for high pH`s. For this reason, water constitutes an aggressive environment. For hydraulic structures, or nuclear waste disposal, water must be considered as a `chemical loading`. In the short- and medium-term water-degradation of cement paste is principally due to transport of matter between the healthy zone and the aggressive solution through diffusion of ionic species from the interstitial solution of the cement paste. In the long-term, dissolution of the surface may occur. Various cement pastes were prepared and leached with continually demineralized water. After a critical time, which depends on the type of paste, the dissolution of the surface layer in contact with water will control the degradation kinetics. The diffusive and chemical properties of the degraded layer are therefore fundamental for the prediction of the long-term behaviour of concrete in water. {sup 29}Si Magic Angle Spinning Nuclear Magnetic Resonance (MAS NMR) combined with {sup 27}A1 MAS NMR and {sup 57}Fe Moessbauer spectroscopy indicate that the superficial layer is formed by a CSH with a molecular structure near from the tobermorite mineral. Nuclear magnetic resonance techniques allow us to demonstrate the fundamental role of cationic substitutions occurring in the CSH during degradation on the superficial layer solubility. Our experimental results were used to model the cement paste behaviour taking into account the diffusion and the dissolution of the material. (author).

  1. Institute for separation chemistry of Marcoule I.C.S.M; Institut de chimie separative de Marcoule I.C.S.M

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Institute for Separation Chemistry was created in March 2007, and the building including laboratory and offices will be opened to scientists and technicians the middle of 2008. Since resources in Uranium are scarce and wastes related to nuclear energy production are potentially dangerous, the chemistry associated to nuclear energy production always followed the principles of green chemistry: close the life-cycle of material and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in processes. The Institute is devoted to chemistry at the service of the nuclear energy of the future, seen as an actor for sustainable development compatible with limited resources and chemical preservation of the atmosphere. Progresses in fundamental research, based on publication and education of students, engineers and young scientists, will be focused along seven identified directions, devoted to scattering and diffraction, microscopies and mainly mesoscopic modelling. The goals of the teams are described in this booklet, describing activities of the 28 scientists since two years. Separation chemistry, a branch of physical chemistry, is a key actor in 'green chemistry'. Nano-science and physical chemistry, at the roots of modern chemistry considering also non-covalent and long-range interactions, need to be included along the 'tools' involved in new processes. Three axis of research will be privileged: initial steps of separation, via dissolution by sono-chemical means, ion separation via colloids and complex fluids, and maintaining the separation between species involving self-repairing nano-materials, once the evolution of the interface fed from the evolving interface has been modelled. Eleven permanent staff scientists are already active since a few months on average at ICSM at the date of this report (5 CEA, 2 Universities and 4 CNRS). Teaching, scientific animation, summer schools and the common laboratory book of the UMR 5257 ICSM are managed by a team from CEA/INSTN. The activity report regroups goals of teams starting to work, together with previous recent activities of scientists now belonging to ICSM. This report describes the work done before (2003-2007) creation of ICSM by scientists now belonging to ICSM as well as the scientific work done in the first months of existence of ICSM, in the form of scientists integrated in host laboratories. Work done before is described on pages with a frame concern research performed before by scientists now staff permanent scientists at ICSM and related to the goals of ICSM. ICSM will be build by conjunction of the knowledge of scientists joining the group: at the date of writing - ten months before opening of the laboratory - 1/4 of the total number of permanent scientists have already joined the UMR 5257 and convene once every month. The report could have been presented either in administrative order, i.e. by the 'number' of the team, or starting from analysis of needs in nuclear and green chemistry. We have chosen the chronological order, i.e. the order of effective starts of experiments made by permanent ICSM staff.

  2. Couplings in multiphasic geo-materials: temperature and chemistry effects; Couplages dans les geomateriaux multiphasiques: effets de la temperature et de la chimie

    Energy Technology Data Exchange (ETDEWEB)

    Ghasemzadeh, H.

    2006-05-15

    Transport of chemical components in soil through water is the major cause of pollution of the soil. This transport takes place around landfills and nuclear waste storage areas, tailings and mine wastes, and so on. A great number of these sites are unsaturated of water and in some cases heat can change the fate of chemical species, that lead us to a coupled problem. In this dissertation, numerical simulation with an existent thermo-hydro-mechanical model and theoretical modeling and numerical simulation of transport and interactions of one chemical species in multiphase media are presented. Integrated THM model in the Code-Aster is presented. Excavation, engineering barrier and thermal load of waste nuclear storage well are modeled. Verification of model is presented with these simulations. A thermo-hydro-mechanical behaviour coupled with chemical phenomena is presented with a fully coupled method that water, gas, chemical species and soil skeleton were considered as constituents and corresponding unknowns are temperature, water pressure, gas pressure, chemical concentration and displacements. For each constituent, mass balance equation and linear momentum equation are written and solved simultaneously to find related unknowns. The results of this model have been compared with the theoretical and experimental results existing in the literature. Furthermore, results of some applications of this model are included. Some areas where further work is required are identified. In particular, there is a need to perform experiments to obtain necessary soil parameters to permit accurate modelling of the heat and contaminant transport in unsaturated soils. (author)

  3. Uranium chemistry in blood and aqueous media. Techniques of studies; Chimie de l`uranium en milieux aqueux et sanguin. Techniques d`etudes

    Energy Technology Data Exchange (ETDEWEB)

    Scapolan, St

    1996-11-01

    The object of this report in a first step, is to understand the chemistry of uranium in aqueous phase by specifying the behavior of this element in function of several parameters such PH, concentration of present species, temperature, ionic force. In a second step, investigation techniques are reviewed: X rays diffraction, potentiometric titrations, polarography, spectrophotometry, NMR of {sup 13}C, {sup 31}P, {sup 17}O, capillary electrophoresis, laser detection. The third part brings elements to understand the uranium complexation in blood medium.

  4. Applications of electron spin resonance to some problems of radiation chemistry; Applications de la resonance paramagnetique electronique a quelques problemes de chimie sous rayonnements

    Energy Technology Data Exchange (ETDEWEB)

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

    1968-06-01

    The electron spin resonance (E.S.R.) spectra of gamma irradiated polar organic glasses, at 77 K, shows a single line centered at g {approx} 2, attributed to solvated electrons. The radicals produced on scavenging this species by electron acceptors, such as aromatic hydrocarbons, nitro-compounds and azines have been studied by E.S.R. In most cases, the radicals from these solutes, the spectra of which are observed after elimination by warming of the radicals from the matrices, are produced by protonation of the anions formed by scavenging of electrons at 77 K. Thus, in the case of glassy solutions of nitro-compounds, the radicals R NO{sub 2}H are formed. They are characterized by a{sub N} = 15 G (nitrobenzene) or a{sub N} = 28 G (nitro-alkane). These radicals are also generated by U.V, photolysis at room temperature of solutions of nitro-compounds in alcohols and are shown to be the precursors of nitroxide radicals R - N - R (with N - O) observed simultaneously. Gamma irradiation of solutions of pyridine and of the three diazines, in alcohol glasses at 77 K, produces the radical formed by hydrogen addition to these compounds. The value of the coupling constant of the additional proton (7-10 G) indicates that it is bound to a nitrogen in the sp{sup 2} hydridation state. One has shown, taking pyridine as an example, that the addition to a carbon gives a much greater value of the coupling constant, of the order of 50-60 G. (author) [French] Les spectres de resonance paramagnetique electronique (R.P.E.) obtenus apres irradiation gamma, a 77 K, de verres organiques polaires tels que les alcools, comportent une bande unique centree a g {approx} 2, attribuable aux electrons solvates. On etudie par R.P.E. les radicaux provenant de leur capture par des solutes ayant une affinite electronique, en particulier les hydrocarbures aromatiques, les composes nitres et les azines. En general, les radicaux provenant de ces solutes, dont on observe les spectres apres elimination specifique des radicaux de la matrice par rechauffement, resultent de la protonation des anions formes par capture des electrons a 77 K. Ainsi, dans le cas de solutions vitreuses de composes nitres, il se forme les radicaux R NO{sub 2}H caracterises par a{sub N} = 15 G (nitrobenzene) ou a{sub N} = 28 G (nitro-alcanes). On observe transitoirement ces memes radicaux par photolyse U.V. de solutions de composes nitres dans les alcools, a temperature ambiante, dans la cavite du spectrometre et l'on montre qu'ils sont les precurseurs de radicaux nitroxydes R - N - R (avec N - O) observes simultanement. Les solutions de pyridine et des trois diazines dans les alcools, irradiees a 77 K donnent les radicaux produits par addition d'hydrogene sur ces composes. Il semble que le proton supplementaire, dont la constante de couplage est de 7 a 10 G, soit lie a un azote dans l'etat d'hybridation sp{sup 2}. On montre que l'addition sur un carbone donnerait une constante de couplage beaucoup plus elevee, de l'ordre de 50 a 60 G, dans le cas de la pyridine. (auteur)

  5. New 'chimie douce' approach to the synthesis of hybrid nanosheets of MoS2 on CNT and their anti-friction and anti-wear properties.

    Science.gov (United States)

    Altavilla, Claudia; Sarno, Maria; Ciambelli, Paolo; Senatore, Adolfo; Petrone, Vincenzo

    2013-03-29

    Hybrid organic-inorganic oleylamine@MoS2-CNT nanocomposites with different compositions were obtained by thermal decomposition of tetrathiomolybdate in the presence of oleylamine and high quality multiwalled carbon nanotubes (CNTs) previously prepared by the CCVD technique. The nanocomposite samples were characterized by the TEM, SEM TG-MS, Raman and XRD techniques and successfully tested as anti-friction and anti-wear additives for grease lubricants.

  6. Chemical industry, how to adapt and invest facing new regulations; Chimie, comment s`adapter et investir face aux nouvelles regles?

    Energy Technology Data Exchange (ETDEWEB)

    Paules, B. [Elf Atochem, 92 - Puteaux (France). Direction Technique

    1997-12-31

    In order to reduce NOx emission levels from a fuel oil or gas burning boiler for a chemical plant, a system using injection of gaseous ammoniacal compounds in fumes combined to hydrogen injection for controlling reaction kinetics, is presented (Thermal De-NOx process from Exxon Research and Engineering); its implementation in a cogeneration plant (gas and fuel oil) is described. NOx, NH{sub 3} and oxygen are combined to form nitrogen and water. The process equipment and control system are presented. Emission levels are compared to limit values according to the system configuration (boiler or turbine) and to post-combustion operation

  7. Chemistry. How to adapt and invest in front of the new rules?; Chimie. Comment s`adapter et investir face aux nouvelles regles?

    Energy Technology Data Exchange (ETDEWEB)

    Paules, B. [ELF Atochem, 92 - Puteaux (France)

    1997-12-31

    This paper is a series of transparencies about the experience of Elf Atochem company in the reduction of NO{sub x} emissions from petrochemical plants. The St Auban plant (France) is taken as a first example: description, regulations and NO{sub x} reduction goals, NO{sub x} reduction techniques (non-reheating of the combustion air, modifications on burners, injection of ammonia-compounds in smokes), results of the preliminary study on ammonia-compounds injection, application and principle of regulation. The second example concerns the development of a cogeneration system in the Marseille plant (description of existing installations, the cogeneration installation project, the regulatory context, the gas turbine and its post-combustion system, the dual-fuel system and the pollution regulations: chimney height, limit values of NO{sub x} and dust emissions). (J.S.)

  8. Institute for separation chemistry of Marcoule I.C.S.M; Institut de chimie separative de Marcoule I.C.S.M

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    Institute for Separation Chemistry was created in March 2007, and the building including laboratory and offices will be opened to scientists and technicians the middle of 2008. Since resources in Uranium are scarce and wastes related to nuclear energy production are potentially dangerous, the chemistry associated to nuclear energy production always followed the principles of green chemistry: close the life-cycle of material and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in processes. The Institute is devoted to chemistry at the service of the nuclear energy of the future, seen as an actor for sustainable development compatible with limited resources and chemical preservation of the atmosphere. Progresses in fundamental research, based on publication and education of students, engineers and young scientists, will be focused along seven identified directions, devoted to scattering and diffraction, microscopies and mainly mesoscopic modelling. The goals of the teams are described in this booklet, describing activities of the 28 scientists since two years. Separation chemistry, a branch of physical chemistry, is a key actor in 'green chemistry'. Nano-science and physical chemistry, at the roots of modern chemistry considering also non-covalent and long-range interactions, need to be included along the 'tools' involved in new processes. Three axis of research will be privileged: initial steps of separation, via dissolution by sono-chemical means, ion separation via colloids and complex fluids, and maintaining the separation between species involving self-repairing nano-materials, once the evolution of the interface fed from the evolving interface has been modelled. Eleven permanent staff scientists are already active since a few months on average at ICSM at the date of this report (5 CEA, 2 Universities and 4 CNRS). Teaching, scientific animation, summer schools and the common laboratory book of the UMR 5257 ICSM are managed by a team from CEA/INSTN. The activity report regroups goals of teams starting to work, together with previous recent activities of scientists now belonging to ICSM. This report describes the work done before (2003-2007) creation of ICSM by scientists now belonging to ICSM as well as the scientific work done in the first months of existence of ICSM, in the form of scientists integrated in host laboratories. Work done before is described on pages with a frame concern research performed before by scientists now staff permanent scientists at ICSM and related to the goals of ICSM. ICSM will be build by conjunction of the knowledge of scientists joining the group: at the date of writing - ten months before opening of the laboratory - 1/4 of the total number of permanent scientists have already joined the UMR 5257 and convene once every month. The report could have been presented either in administrative order, i.e. by the 'number' of the team, or starting from analysis of needs in nuclear and green chemistry. We have chosen the chronological order, i.e. the order of effective starts of experiments made by permanent ICSM staff.

  9. Dynamic-chemistry-aerosol modelling interaction: the ESCOMPTE 2001 experiment; Modelisation de l'interaction dynamique- chimie - aerosol: campagne ESCOMPTE 2001

    Energy Technology Data Exchange (ETDEWEB)

    Cousin, F

    2004-09-01

    After most pollution studies independently devoted to gases and aerosols, there now appears an urgent need to consider their interactions. In this view, an aerosol module has been implemented in the Meso-NH-C model to simulate two IOPs documented during the ESCOMPTE campaign which took place in the Marseille/Fos-Berre region in June-July 2001. First, modelled dynamic parameters (winds, temperatures, boundary layer thickness) and gaseous chemistry have been validated with measurements issued from the exhaustive ESCOMPTE database. Sensitivity analysis have also been performed using different gaseous emission inventories at various resolution. These simulations have illustrated the deep impact of both synoptic and local dynamics on observed ozone concentrations on June 24 (IOP2b) in the ESCOMPTE domain. Afterwards, the ORISAM aerosol module has been introduced into the Meso-NH-C model. Dynamics, gaseous chemistry and aerosol processes have thus been coupled on-line. The particulate pollution episode on June 24 (IOP2b) has been characterised through a satisfactory comparison, specially from sub-micron particles, between modelling and measurements at different representative stations in the domain. This study, with validation of the particulate emission inventory has also highlighted the need for future improvements, such as further characterisation of organic and inorganic aerosol species and consideration of coarse particles. Aerosol impact on gaseous chemistry has been preliminary approached in view of future development and modification to be given to the Meso-NH-C model. (author)

  10. Industrial applications of membrane processes in chemistry and energy generation; Applications industrielles des procedes membranaires en chimie et production d'energie

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The French membranes club (CFM), with the sustain of the French institute of petroleum (IFP) has organized this meeting which aims to present the most recent industrial realizations in the domain of membrane processes in the chemistry and energy generation sectors. This document gathers the abstracts of the presentations: 1 - hydrogen purification and CO{sub 2} extraction: development of polymer matrix and metal nano-particulate hybrid membranes for selective membrane applications; study of silicone-based mixed matrix membranes for hydrogen purification via inverse selectivity principle; CO{sub 2} capture from gaseous effluents for its sequestration: role and limitations of membrane processes; membranes and processes for the abatement of the acid gas content of smokes; new structural model for Nafion{sup R} membranes, the benchmark polymer for low temperature fuel cells; 2 - molecular screen-based membranes: MFI-alumina nano-composite ceramic membranes: preparation and characterization, gaseous transport and separation; characterization and permeation properties of supported MFI membranes; in-situ measurement of butane isomers diffusion in MFI zeolite membranes through transient permeation tests; 3 - vapors separation: stability of silver particulates in PA12-PTMO/AgBF{sub 4} composite membranes and its effect on the easier ethylene transport inside these membranes; 4 - separation of liquid organic mixtures: isomers separation using cyclo-dextrins bearing membranes: application to the extraction and separation of xylene isomers; electrodialysis in organic environment: application to the electro-synthesis; study of polymer materials permeability; 5 - treatment of industrial waters: use of NanoFlux software in the modeling of nano-filtration membrane processes in the chemical industry: elimination of sulfate impurities from 'Chloralkali' brines; ultra-filtration of a wastewater containing partially emulsified oil; efficiency of a hybrid membrane separation process for the processing of industrial effluents; 6 - membrane reactors: membrane catalytic reactors: extraction, isobutane dehydrogenation and xylenes isomerization; selective oxidation of n-butane, water treatment by gas-liquid processes; selectiveness improvement of the butadiene selective hydrogenation with the use of a membrane reactor; comparison of the efficiency of three catalytic reactors for the destruction of VOCs; 7 - gases and vapors separation: a new generation of particulate filters with catalyst impregnation for DeNox function; use of membranes for uranium enrichment: example of the EURODIF plant; inorganic membranes for integration in power generation cycles and hydrogen production; treatment of natural gas with Air Liquide-MEDAL hollow fiber membranes; 8 - liquids separation: nano-filtration in organic environment: state-of-the-art; recycling of organic compounds by inverse osmosis and seawater sulfate removing by nano-filtration; use of organic and mineral membranes in chemistry; membrane separation in chemicals manufacture; advantages and drawbacks of different membrane systems for the treatment of industrial water; concentration and recovery of organic pigments using ceramic membranes; 9 - membranes, processes and simulation: industrial experience with hybrid distillation - pervaporation or vapor permeation applications; electro-dialysis integration in amines and glycol solutions purification processes; integration of MFI membranes in the light gasoline isomerization process. (J.S.)

  11. Molecular Simulation of the Vapor-Liquid Phase Behavior of Lennard-Jones Mixtures in Porous Solids

    Science.gov (United States)

    2006-09-01

    sur la Catalyse, Centre National de la Recherche Scientifique, Group de Chimie Theorique, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex, France...and Group de Chimie Theorique, Ecole Normale Superieure de Lyon, 46 Allee d’Italie, 69364 Lyon, Cedex 07, France 14. ABSTRACT We present vapor...Scientifique, Group de Chimie Theorique, 2 Avenue Albert Einstein, 69626 Villeurbanne Cedex, France and Group de Chimie Theorique, Ecole Normale

  12. Hodnocení středověké keramiky z Lažan u Chrudimi pomocí analýz XRF, XRD, OM, DSC-TG a RS

    Czech Academy of Sciences Publication Activity Database

    Kloužková, A.; Zemenová, P.; Frolík, Jan; Svobodová, Ljuba

    2014-01-01

    Roč. 39, č. 1 (2014), s. 75-87 ISSN 0231-5823. [Mezinárodní konference archeologie středověku /45./. Kutná Hora, 16.09.2013-19.09.2013] Institutional support: RVO:67985912 Keywords : pottery * Lažany * XRD, XRF, DSC analyses Subject RIV: AC - Archeology, Anthropology, Ethnology

  13. Modelling of Molecular Structures and Properties. Proceedings of the International Meeting of Physical Chemistry on Modeling of Molecular Structures and Properties in Physical Chemistry and Biophysics Organized by the Division de Chimie Physique of the Societe Francaise de Chimie Held in Nancy, France on 11-15 September 1989

    Science.gov (United States)

    1990-01-01

    vibrations for both anomers.Then this set of parameters has been used for others monosaccharides , i.e. both anomers of galactose, methyl- C-D-glucose and N...will be used to perform dynamics simulation of polysaccharides . CONCLUSION The vibrational spectroscopy (frequencies and intensities of vibrational

  14. Odvrácená tvář otce egyptské archeologie William Matthew Flinders Petrie a eugenická věda // The Dark Side of the Father of Egyptian Archaeology William Matthew Flinders Petrie and Eugenic Science

    Directory of Open Access Journals (Sweden)

    Kamila Tomášková

    2016-06-01

    Full Text Available The text aims to bring attention of the Czech readers to Petrie's contributions to the eugenics movement in Great Britain. It describes his close association with Francis Galton and his resulting pronounced views on eugenics and shows how Petrie's racist opinions and involvement in eugenics influenced hi s work as an archaeologist and historian. An attempt is made to understand Petrie's views in the context ofhis times instead of condemning him for hi s appalling conclusions motivated by his racism and eugenics beliefs. The text offers a perspective which enables the readers to consider Petrie's thoughts in relation to the eugenic movement which was not on ly favoured by many ofhis contemporaries, but also had many supporters Jong after Petrie's death. Any consideration of the influence of past ideologies and context on Petrie's thinking and research also brings forward an unanswerable question ofhow much each one of u s is influenced by the ideologies and the context(s prevalent in present times and culture.

  15. Global Catastrophes in Earth History: An Interdisciplinary Conference on Impacts, Volcanism, and Mass Mortality

    Science.gov (United States)

    1988-01-01

    Topics addressed include: Cretaceous-Tertiary mass extinctions; geologial indicators for meteorite collisions; carbon dioxide catastrophes; volcanism; climatic changes; geochemistry; mineralogy; fossil records; biospheric traumas; stratigraphy; mathematical models; and ocean dynamics.

  16. Chemistry of tetravalent actinides phosphates. The thorium phosphate-diphosphate as immobilisation matrix of actinides; Chimie des phosphates d'actinides tetravalents. Le phosphate-diphosphate de thorium en tant que matrice d'imobilisation des actinides

    Energy Technology Data Exchange (ETDEWEB)

    Dacheux, N

    2002-07-01

    The author presents in this document its scientific works from 1992 to 2001, in order to obtain the enabling to manage scientific and chemical researches at the university Paris Sud Orsay. The first part gives an abstract of the thesis on the characterizations, lixiviation and synthesis of uranium and thorium based phosphate matrix in the framework of the search for a ceramic material usable in the radioactive waste storage. The second part presents briefly the researches realized at the CEA, devoted to a reliable, independent and accurate measure of some isotopes activity. The last part presents the abstracts of researches activities from 1996 to 2001 on the tetravalent actinides phosphates chemistry, the sintering of PDT and solid solutions of PDTU and the kinetic and thermodynamical studies of the PDT dissolution. Many references and some publication in full text are provided. (A.L.B.)

  17. Nouveaux développements dans la chimie des sels de diazonium en catalyse organométallique : catalyse hétérogène en milieux aqueux

    OpenAIRE

    Le Callonnec , Francois

    2014-01-01

    Diazonium salts are reactive and versatile when used as electrophiles. Unfortunately, their reputation as instable compounds strongly limited their use in chemical synthesis. This work lead to the discovery of new procedure for a safer and more environmentally friendly use of diazonium salts in organometallic coupling reactions. We studied palladium catalised carbon-carbon coupling reactions and copper catalyzed C-H arylatons. A major part of this work is also focalized in the development of ...

  18. Theoretical study of the electronic structure of f-element complexes by quantum chemical methods; Analyse de la structure electronique des complexes contenant des elements F par des methodes de la chimie quantique

    Energy Technology Data Exchange (ETDEWEB)

    Vetere, V

    2002-09-15

    This thesis is related to comparative studies of the chemical properties of molecular complexes containing lanthanide or actinide trivalent cations, in the context of the nuclear waste disposal. More precisely, our aim was a quantum chemical analysis of the metal-ligand bonding in such species. Various theoretical approaches were compared, for the inclusion of correlation (density functional theory, multiconfigurational methods) and of relativistic effects (relativistic scalar and 2-component Hamiltonians, relativistic pseudopotentials). The performance of these methods were checked by comparing computed structural properties to published experimental data, on small model systems: lanthanide and actinide tri-halides and on X{sub 3}M-L species (X=F, Cl; M=La, Nd, U; L = NH{sub 3}, acetonitrile, CO). We have thus shown the good performance of density functionals combined with a quasi-relativistic method, as well as of gradient-corrected functionals associated with relativistic pseudopotentials. In contrast, functionals including some part of exact exchange are less reliable to reproduce experimental trends, and we have given a possible explanation for this result . Then, a detailed analysis of the bonding has allowed us to interpret the discrepancies observed in the structural properties of uranium and lanthanides complexes, based on a covalent contribution to the bonding, in the case of uranium(III), which does not exist in the lanthanide(III) homologues. Finally, we have examined more sizeable systems, closer to experimental species, to analyse the influence of the coordination number, of the counter-ions and of the oxidation state of uranium, on the metal-ligand bonding. (author)

  19. Research on the chemistry of actinides and fission products for the development of nuclear fuel cycle; Developpement du cycle du combustible nucleaire. Recherche sur la chimie des actinides et des produits de fission

    Energy Technology Data Exchange (ETDEWEB)

    Peretroukhine, V.F. [Institute of Physical Chemistry Russian Academy of Sciences (IPC-Moscow) (Russian Federation); Lecomte, M. [CEA Valrho, Dept. Radiochimie et Procedes, 30 - Marcoule (France); David, F. [Institut de Physique Nucleaire, (IN2P3/CNRS) 91 - Orsay (France)

    2004-07-01

    The present document is prepared for CEA, IPNO and Russian Academy of Sciences administrations in compliance with the decision, accepted by the Director Committee of the three-parties-Convention on its seventh meeting in Moscow 21 May 2002. Being the general frame, determining the strategy of three-party cooperation, the Convention 1993-2003 consists of the number of contracts between organisation-participants. The present document is compiled, using annual proceedings of Director Committee and Technical Committee meetings and using published French-Russian papers and technical reports, produced in the frame of all contracts of the convention. Lists of published papers and personal summary reports of Russian participants of the contracts are presented in Appendix 1. (authors)

  20. {sup 63}Ni and {sup 137}Cs chemistry in the soil-plant system; Chimie de {sup 63}Ni et de {sup 137}Cs dans le systeme sol-plante

    Energy Technology Data Exchange (ETDEWEB)

    Pinel, F

    2002-06-01

    The treatment and storage of radioactive waste are the responsibility of the ANDRA (The french agency for the management of radioactive wastes). The impact to man, via the entry in the human food chain depends on the mobility of each radionuclide in soil, root uptake and the subsequent redistribution in the plant. The distribution coefficient, Kd, is thought to be a good, estimator of bioavailability. We have investigated a large number of plant species (11 for caesium and 7 for nickel) in contact with contrasting soils under controlled conditions. Nickel adsorption has also been measured under controlled conditions. Particular attention has been paid to the consequences of modification of soil properties in the rhizosphere. This study confirms that the value of Kd is a good indicator of bioavailability of both nickel and caesium and that the value of Kd measured in dilute suspension may be extrapolated to that under in situ conditions. The value of Kd depends on soil pH, solution ionic strength, the presence of complexing ligands and redox conditions. The differences observed between species in nickel uptake may often be related to changes in rhizosphere pH and parallel modifications in Kd. The translocation of nickel from roots to shoots for a given species depends on the conditions of growth, due in part to access to different pools of soil nickel. (author)

  1. Modelling of Molecular Structures and Properties in Physical Chemistry and Biophysics, Forty-Fourth International Meeting (Modelisation des Structures et Proprietes Moleculaires en Chimie Physique et en Biophysique, Quarante- Quatrieme Reunion Internationale)

    Science.gov (United States)

    1989-09-01

    apprcc-he novatzice, fondde sur une perception de I’ envixcnnmnt local des atoi-es dolt of frir des resssources inr~rtantes dans le traitement de tous les...Acta, 72, 1-13 (1989). 2586 Etude thdorique de la structure du compiexe Giutathion - Eau oxygdn4e J.Berg~s , JCaillet Dynamique des Interactions Mol...est connu que !a r6action d’oxydati4on du glutathion par 1! eau oxyg~n6e est catalys~e, in vivo, par une enzyme, la glutathion peroxydase. I’l a4t

  2. Les zéolithes comme catalyseurs "verts" pour la synthèse organique : de leur synthèse à façon à leurs applications en chimie organique

    OpenAIRE

    Bernardon , Claire

    2016-01-01

    Zeolites are crystalline porous aluminosilicates and useful heterogeneous catalysts in chemical industries. They represent one of the significant solutions to main environmental concerns. Thanks to their particular properties like shape selectivity and intrinsic acidities of Lewis and Brønsted, zeolites offer unbeatable abilities in organic synthesis. More than 230 structures have already been discovered, which afford thousands discovery and offer a lot of possibilities.This work was focused ...

  3. Rhéologie des bétons fluides à hautes performances : relations entre formulations, propriétés rhéologiques, physico-chimie et propriétés mécaniques

    OpenAIRE

    Yammine , Joumana

    2007-01-01

    The High Performance Concrete, from high to low plastic consistency, develops high long term mechanical resistances. Nevertheless, it presents the disadvantage of a very hard filling in dense steel reinforcements rebars like in the Millau's viaduct piles, which constitute a framework of barriers for the concrete casting by vibration. To guarantee a total filling in the framework, the self compacting concretes are the issue and are adopted respecting mechanical performances and durability main...

  4. Chemistry of complexing molecules and environment. Report of the working group of the Cea ''mission environment''; Chimie des complexants en environnements. Rapport du groupe de travail de la mission environnement

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J.C

    1998-07-01

    The Working group 'Chemistry of Complexing Molecules and Environment' of the Mission Environment (AG/ENV) identified themes for an original positioning of CEA on important issues of environmental research if a sufficiently strong demand appears. The research of CEA on the environment should be complementary to actions undertaken by other partners (official institutions, research organizations and industrial firms). The themes suggested are: the synthesis of new chelating molecules and new materials having specific properties, with the support of theoretical chemistry and modeling, analytical physical chemistry and speciation of species in relation to their eco-toxicity and their biogeochemical mobility in the natural environment. These themes, illustrated by examples of actions in progress at CEA or likely to be launched quickly, draw largely from recognized competences of the teams, generally developed for finalized nuclear applications: experimental, theoretical and instrumental competences. (author)

  5. Révéler la chimie des préparations antiques, à usage cosmétique ou médical, impliquant des sels de métaux lourds

    OpenAIRE

    Aubin , Marlène

    2016-01-01

    In the Antiquity, oculists (eye care specialised physicians) mixed mineral, vegetal and animal substances to prepare elaborate solid medicines termed collyria. In an interdisciplinary work, we investigated the chemical composition, the inorganic phases structure and the manufacturing process of such collyria. The implemented analytical techniques were Raman spectroscopy, X-ray fluorescence (XRF) and X-ray diffraction (XRD). The stability of metallic salts based replicas prepared according to ...

  6. Primary processes in radiation chemistry. LET (Linear Energy Transfer) effect in water radiolysis; Processus primaires en chimie sous rayonnement. Influence du transfert d'energie lineique sur la radiolyse de l'eau

    Energy Technology Data Exchange (ETDEWEB)

    Trupin-Wasselin, V

    2000-07-11

    The effect of ionizing radiations on aqueous solutions leads to water ionization and then to the formation of radical species and molecular products (e{sup -}{sub aq}, H{sup .}, OH{sup .}, H{sub 2}O{sub 2}, H{sub 2}). It has been shown that the stopping power, characterized by the LET value (Linear Energy Transfer) becomes different when the nature of the ionizing radiations is different. Few data are nowadays available for high LET radiations such as protons and high energy heavy ions. These particles have been used to better understand the primary processes in radiation chemistry. The yield of a chemical dosimeter (the Fricke dosimeter) and those of the hydrogen peroxide have been determined for different LET. The effect of the dose rate on the Fricke dosimeter yield and on the H{sub 2}O{sub 2} yield has been studied too. When the dose rate increases, an increase of the molecular products yield is observed. At very high dose rate, this yield decreases on account of the attack of the molecular products by radicals. The H{sub 2}O{sub 2} yield in alkaline medium decreases when the pH reaches 12. This decrease can be explained by a slowing down of the H{sub 2}O{sub 2} formation velocity in alkaline medium. Superoxide radical has also been studied in this work. A new detection method: the time-resolved chemiluminescence has been perfected for this radical. This technique is more sensitive than the absorption spectroscopy. Experiments with heavy ions have allowed to determine the O{sub 2}{sup .-} yield directly in the irradiation cell. The experimental results have been compared with those obtained with a Monte Carlo simulation code. (O.M.)

  7. Modélisation cinétique et hydrodynamique pour la physique, la chimie et la santé, analyse mathématique et numérique

    OpenAIRE

    Boudin , Laurent

    2011-01-01

    Mes travaux de recherche portent sur la mécanique des fluides, et plus précisément sur les systèmes de particules, avec plusieurs domaines d'applications : le poumon (aérosol thérapie, pollution, régimes diffusifs), la formation d'opinion (sociophysique), et le couplage entre un fluide et une phase dispersée. La plupart de mes travaux s'appuient sur la théorie cinétique, où apparaissent des équations aux dérivées partielles cinétiques où l'inconnue est une fonction de distribution ayant pour ...

  8. Développement d'une stratégie d'adressage sur or par chimie "click" électro-catalysée : application à la détection sans marquage de biomolécules

    OpenAIRE

    Ripert , Micaël

    2013-01-01

    This production of microsystem for label-free multi detection of biomolecules is fundamental for the realization of rapid tests dedicated to laboratory diagnosis. A viable method is requires to both address capture probes and to be associates with a sensitive analysis on multiplexed platform. In this study, the method chosen for detection on electrode is cyclic voltammetry, and ferrocene was used to modify stem-loop oligonucleotides. A strategy was developed for the electroadressing of probes...

  9. Chimie et mécanisme dans la nouvelle Académie royale des sciences : les débats entre Louis Lémery et Etienne-François Geoffroy

    Directory of Open Access Journals (Sweden)

    Bernard Joly

    2008-03-01

    Full Text Available Au début du XVIIIe siècle, une querelle éclate entre deux chimistes français à propos de la fabrication artificielle du fer. C’est en fait un conflit entre une interprétation mécaniste des processus chimiques et une approche plus traditionnelle, soupçonnée d’emprunter ses thèses à l’alchimie, mais qui sera pourtant à l’origine de la table des affinités qui sera adoptée par tous les chimistes jusqu’au début du XIXe siècle.In the early eighteenth century a quarrel came out between two French chemists concerning artificial making of iron. It was in fact a conflict between a mechanist interpretation of chemical process and a more traditional approach, which was suspected of having taken his thesis from alchemy. But nevertheless, this approach will lead to affinity table which was accepted by all the chemists until the early nineteenth century.

  10. Chemistry of complexing molecules and environment. Report of the working group of the Cea ''mission environment''; Chimie des complexants en environnements. Rapport du groupe de travail de la mission environnement

    Energy Technology Data Exchange (ETDEWEB)

    Petit, J C

    1998-07-01

    The Working group 'Chemistry of Complexing Molecules and Environment' of the Mission Environment (AG/ENV) identified themes for an original positioning of CEA on important issues of environmental research if a sufficiently strong demand appears. The research of CEA on the environment should be complementary to actions undertaken by other partners (official institutions, research organizations and industrial firms). The themes suggested are: the synthesis of new chelating molecules and new materials having specific properties, with the support of theoretical chemistry and modeling, analytical physical chemistry and speciation of species in relation to their eco-toxicity and their biogeochemical mobility in the natural environment. These themes, illustrated by examples of actions in progress at CEA or likely to be launched quickly, draw largely from recognized competences of the teams, generally developed for finalized nuclear applications: experimental, theoretical and instrumental competences. (author)

  11. La chute de litière et la chimie de la litière changent au fil du temps dans une vieille forêt tempérée du Nord-Est de la Chine

    OpenAIRE

    Li , Xuefeng; Hu , Yanling; Han , Shijie; Liu , Ying; Zhang , Yan

    2010-01-01

    International audience; Litterfall and litter chemistry are key factors for the assessment of forest floor properties. A long-term study on litterfall, litter chemistry and forest basal areas was carried out in an old-growth temperate forest, northeastern China.* The objective of this study was to test whether forest floor properties in the old-growth forest remain relatively constant.* Litterfall increased significantly over the past 27 y but litterfall of various litter components showed di...

  12. Soubor renesančních bot ze studny u kostela Všech svatých na Pražském hradě

    Czech Academy of Sciences Publication Activity Database

    Bravermanová, H.; Březinová, Helena; Hlaváček, P.

    1998-01-01

    Roč. 23, - (1998), s. 471-492 ISSN 0231-5823. [Celostátní konference archeologů středověku České republiky a Slovenské republiky k problematice archeologie středověkých komunikací. Prachatice, 06.10.1997-10.10.1997] Subject RIV: AC - Archeology, Anthropology, Ethnology

  13. Příběhy rekonstrukčních řezů historickým nadložím Pražského hradu

    Czech Academy of Sciences Publication Activity Database

    Boháčová, Ivana

    2017-01-01

    Roč. 10, č. 2 (2017), s. 108-124 ISSN 1803-1749. [Archeologie ve městě. Strategie, metodika, metody výzkumu, prezentace a ochrany archeologických památek. Mělník, 01.06.2016-03.06.2016] R&D Projects: GA MK(CZ) DF13P01OVV014 Keywords : archaeology * methodology * central site * Early Middle Ages Subject RIV: AC - Archeology, Anthropology, Ethnology OBOR OECD: Archaeology

  14. Lipid Oligonucleotide Conjugates as Responsive Material

    Science.gov (United States)

    2012-09-28

    Philippe Barthélémy. . An intrusion into the glycolipids’ world? C. R. Chimie , Comptes RendusChimie , (08 2011): 0. doi: 2011/10/04 08:47:00 22...Philippe Barthelemy. Reprints paper associated with ARO , C. R. Chimie , ( 2008): . doi:2009/03/17 06:53:27 2 TOTAL: 7 Number of Papers published in non...nucléiques avec les lipides : De la chimie moléculaire aux applications biomédicales », Rotary Club, L’Isle sur la Sorgue, Décembre 3, (2011), France

  15. Indoor radon concentration: impact of geology in the 2005 Kashmir earthquake-affected Bagh area, Azad Jammu and Kashmir, Pakistan; Concentration de radon interieur: l'impact de la geologie dans la zone Bagh, Azad Jammu et Cachemire, Pakistan affectee par le tremblement de terre de 2005 au Cachemire

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, A.; Khan, S. [Department of Physics, University of Azad Jammu and Kashmir, Muzaffarabad (Pakistan); Baig, M.S. [Institute of Geology, University of Azad Jammu and Kashmir, Muzaffarabad, (Pakistan); Akram, M. [Physics Research Division, PINSTECH, P.O. Nilore, Islamabad (Pakistan)

    2011-07-15

    The early Miocene Murree Formation, late Miocene Nagri Formation and recent alluvium rock units are exposed in the sub-Himalayas of the Bagh area, State of Azad Jammu and Kashmir, Pakistan. The Bagh area was badly affected by the Kashmir earthquake of October 8, 2005 which, along the Muzaffarabad Fault, deformed both the hanging and footwall blocks. The cracks, joints, fissures and fractures in houses and bed-rocks might have affected the emission of radon to the surface. Indoor radon concentration measurements were carried out in some dwellings of the Bagh area, Azad Kashmir, Pakistan. The measurements were based on passive integrative detection of radon using CN-85 plastic track detectors in box-type dosimeters. The radon concentration in dwellings was between 50 {+-} 11.6 Bq.m{sup -3} and 167.1 {+-} 21.4 Bq.m{sup -3} with an overall average of 95.1 {+-} 15.8 Bq.m{sup -3} (geometric mean = 93.4 Bq.m{sup -3}). The average radon concentrations in pucka, semi-pucka and kucha houses were 97.6 {+-} 15.4 Bq.m{sup -3}, 89.7 {+-} 15.2 Bq.m{sup -3} and 101.9 {+-} 15.9 Bq.m{sup -3}, respectively. The mean values of radon concentrations in the Nagri Formation, Murree Formation and recent alluvium lithology were 99.3 {+-} 15.8, 90.1 and 96.2 {+-} 15.5 Bq.m{sup -3}, respectively. The annual effective dose to the Bagh population was calculated as 2.38 {+-} 0.77 (1.33 {+-} 0.2 to 4.7 {+-} 0.5) mSv. The average radon (95.1 {+-} 15.8 B m{sup -3}) concentration in dwellings for the inhabitants of the Bagh area was safe from radon-related health hazards and was within the recommended action level (ICRP publication 65 (1993) Protection against radon at home and at work, International Commission on Radiological Protection, Ann. ICRP 23(2)).The indoor radon values obtained in the present study are more than the world average of 40 Bq.m{sup -3} (UNSCEAR (2000) United Nations Scientific Committee on the Effects of Atomic radiation, Report to the General Assembly, United Nations, New York). (authors)

  16. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Laboratoire Corrosion-Electrochimie, Faculté des Sciences, BP 1014, Avenue Ibn Battouta, Rabat, Morocco; Laboratoire de Chimie Organique Hétérocyclique, Faculté des Sciences, BP 1014, Avenue Ibn Battouta, Rabat, Morocco; Laboratoire de Chimie Organique et d'Etudes Physico-chimiques, Ecole Normale Supérieure ...

  17. Layout ppp

    African Journals Online (AJOL)

    Nubidga

    Evaluation of mineral contents in Cleome gynandra leaves and stalks from Burkina Faso. Research Article. Igor W. K. Ouédraogo1,2, Carole Tranchant2 and Yvonne L. Bonzi-Coulibaly1*. 1 Laboratoire de Chimie Organique : Structure et Réactivité, Département de Chimie, Université de. Ouagadougou, 03 BP 7021 ...

  18. DEMETER Observations of ELF Waves Injected With the HAARP HF Transmitter

    Science.gov (United States)

    2006-08-17

    de Physique et Chimie de l’Environnement, Centre National de la Recherche Scientifique, Orléans, France. 3Naval Research Laboratory, Washington, D. C...stanford.edu) E. J. Kennedy, Naval Research Laboratory, 4555 Overlook Avenue SW, Washington, DC 20375, USA. M. Parrot, Laboratoire de Physique et Chimie

  19. Non-Self-Maintained Discharge Application for Fuel Activation

    Science.gov (United States)

    2010-09-21

    references have been used: Eliasson B., Kogelschatz U., J. de Chimie Physique. 1986. V.83. P.279. Maetzing H. Chemical Kinetics of Flue Gas Cleaning by...Person J.C., Ham D.O. Radiat. Phys. Chem. 1988. V. 31. N.1-3. P. Eliasson B., Kogelschatz U., J. de Chimie Physique. 1986. V.83. P.279. Mukkavilli

  20. History of Biochemistry at the University of Geneva From the Boulevard des Philosophes to Quai Ernest-Ansermet.

    Science.gov (United States)

    Deshusses, Jacques; Riezman, Howard

    2009-12-01

    A brief account of the developments in biochemistry at the Faculty of Science of the University of Geneva is given from its emergence from organic chemistry at the Ancienne Ecole de chimie to today's Department of Biochemistry at the Section de chimie et biochimie.

  1. Study of lithium glassy solid electrolyte/electrode interface by ...

    Indian Academy of Sciences (India)

    Unknown

    Institut de Chimie de la Matière Condensée de Bordeaux – C.N.R.S. et Ecole Nationale Supérieure de Chimie et de ... chemically very stable with the different types of electrodes studied here. ... tigated to improve the battery performance.

  2. Bericht 2005 über fazielle und biostratigraphishe Untersuchungen in der Gosau der Neualm bei Russbach am Pass Gschütt auf Blatt 95 St. Wolfgang

    Czech Academy of Sciences Publication Activity Database

    Hradecká, L.; Lobitzer, H.; Svobodová, Marcela; Švábenická, L.

    2006-01-01

    Roč. 146, 1-2 (2006), s. 132-133 ISSN 0016-7800 Institutional research plan: CEZ:AV0Z30130516 Keywords : sedimentology * paleontology * Gosau Fm., * Northern Calcareous Alps, * Austria Subject RIV: DB - Geology ; Mineralogy http://www.geologie.ac.at/filestore/download/JB1461_132_A.pdf

  3. Za fosilními dřevy do ománské pouště

    Czech Academy of Sciences Publication Activity Database

    Matysová, Petra

    89 /140/, č. 6 (2010), s. 360-363 ISSN 0042-4544 Institutional research plan: CEZ:AV0Z30460519 Keywords : silicified wood * Permian * moganite Subject RIV: DB - Geology ; Mineralogy www.vesmir.cz/abstrakt/za-fosilnimi-drevy-geologie-do-omanske-pouste

  4. 2088-IJBCS-Article-Abdoulaye Seydi

    African Journals Online (AJOL)

    hp

    1Département de Chimie, Faculté des Sciences et Techniques Université, C. A. ... Keywords: Flame structure, lean flames, ethylene, carbonyl compounds, ... formation and emission in exhaust gas or ...... Validation of a thermal decomposition.

  5. Introduction à la théorie quantique concepts, pratiques et applications

    CERN Document Server

    Desouter, Michèle; Chapuisat, Xavier

    2017-01-01

    Introduction à la théorie quantique avec exercices corrigés pour les niveaux licence et master en physique, physico-chimie et chimie, permet d'atteindre une base solide en Mécanique Quantique et le niveau indispensable pour aborder les sujets multidisciplinaires de la recherche actuelle. En complément optionnel sur un site compagnon, des applications interactives.

  6. Uranium (VI) chemistry at the interface solution/minerals (quartz and aluminium hydroxide): experiments and spectroscopic investigations of the uranyl surface species; Chimie de l'uranium (VI) a l'interface solution/mineraux (quartz et hydroxyde d'aluminium): experiences et caracterisations spectroscopiques

    Energy Technology Data Exchange (ETDEWEB)

    Froideval, A.

    2004-09-15

    This study deals with the understanding of the uranyl chemistry at the 0.1 M NaNO{sub 3} solution/mineral (quartz and aluminium hydroxide) interface. The aims are:(i) to identify and to characterize the different uranyl surface species (mononuclear, polynuclear complexes and/or precipitates...), i.e. the coordination environments of sorbed/precipitated uranyl ions, by using X-ray photoelectron spectroscopy (XPS), extended X-ray absorption fine structure (EXAFS) and time-resolved laser-induced fluorescence spectroscopy (TRLFS), and;(ii) to investigate the influence of pH, initial uranyl aqueous concentration and hydroxyl ligand concentration on the uranyl surface speciation. Our study on the speciation of uranyl ions at the quartz surface (i) confirms the formation of uranyl polynuclear/oligomers on quartz from moderate (1 {mu}mol/m{sup 2}) to high (26 {mu}mol/m{sup 2}) uranyl surface concentrations and (ii) show that theses polynuclear species coexist with uranyl mononuclear surface species over a pH range {approx_equal} 5-8.5 and a wide range of initial uranyl concentration o f the solutions (10-100 {mu}M). The uranyl concentration of these surface species depends on pH and on the initial uranyl aqueous concentration. Hydrate (surface-) precipitates and/or adsorbed polynuclear species and monomeric uranyl surface complexes are formed on aluminium hydroxide. Uranyl mononuclear complexes are predominant at acidic pH, as well as uranyl in solution or on the surface. Besides mononuclear species, precipitates and/or adsorbed polynuclear species are predominantly formed at neutral pH values on aluminium hydroxide. A main contribution of our investigations is that precipitation and/or adsorption of polynuclear species seem to occur at low uranyl surface concentrations (0.01-0.4 {mu}mol/m{sup 2}). The uranyl surface speciation is mainly dependent on the pH and the aluminol ligand concentration. (author)

  7. The chemistry of molten salt mixtures: application to the reductive extraction of lanthanides and actinides by a liquid metal; Chimie des melanges de sels fondus. Application a l'extraction reductrice d'actinides et de lanthanides par un metal liquide

    Energy Technology Data Exchange (ETDEWEB)

    Finne, J

    2005-10-15

    The design of a process of An/Ln separation by liquid - liquid extraction can be used for on-line purification of the molten salt in a molten salt nuclear reactor (Generation IV) as well as reprocessing various spent fuels. In order to establish the chemical properties of An and Ln in molten salt mediums, E - pO{sub 2} - diagrams were established for the relevant chemical elements. With the purpose of checking the possibilities of separating the An from Ln, the real activity coefficients in liquid metals were measured. An experimental protocol was developed and validated on the Gd/Ga system. It was then transferred to radioactive environment to measure the activity coefficient of Pu in Ga. The results made it possible to estimate the effectiveness of the Pu extraction and its separation from Gd and Ce. The selectivity was shown to decrease with the temperature and Al and Ga showed a good selectivity between Pu and the Ce in fluoride medium. (author)

  8. Experimental study of chemical-mechanical coupling during percolation of reactive fluid through rocks under stress, in the context of the CO{sub 2} geological sequestration; Etude experimentale du couplage chimie-mecanique lors de la percolation d'un fluide reactif dans des roches sous contrainte, dans le contexte de la sequestration geologique du CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Le Guen, Y

    2006-10-15

    CO{sub 2} injection into geological repositories will induce chemical and mechanical instabilities. The study of these instabilities is based on experimental deformation of natural rock samples under stress, in the presence of fluids containing, or not, dissolved CO{sub 2}. Triaxial cells used for the experiments permitted an independent control and measurement of stress, temperature, fluid pressure and composition. Vertical strains were measured during several months, with a resolution of 1.10{sup -12} s{sup -1} on the strain rate. Simultaneously, fluids were analysed in order to quantify fluid-rock interactions. For limestone samples, percolation of CO{sub 2}-rich fluids increases strain rate by a factor 1.7 up to 5; on the other hand, sandstone deformation remained almost the same. Increase in strain rate with limestone samples was explained by injected water acidification by the CO{sub 2} which increases rock solubility and reaction kinetics. On the opposite, small effect of CO{sub 2} on quartz explains the absence of deformation. X-ray observations confirmed the importance of rock composition and structure on the porosity evolution. Numerical simulations of rock elastic properties showed increasing shear stress into the sample. Measured deformation showed an evolution of reservoir rocks mechanical properties. It was interpreted as the consequence of pressure solution mechanisms both at grains contacts and on grain free surfaces. (author)

  9. The understanding of the R7T7 glass blocks long term behavior: chemical and transport coupling in fractured media; Comprehension de l'alteration a long terme des colis de verre R7T7: etude du couplage chimie transport dans un milieu fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chomat, L

    2008-04-15

    The long term behavior of nuclear waste glass blocks depends highly on chemical reactions which occur at the surface in contact with water. Studies carried out on inactive fractured glass blocks show that fracture networks play a significant part in reactive surface area. Nevertheless, the complexity of results interpretation, due to a weak knowledge of fracture networks and local lixiviation conditions, does not allow us to comprehend the physical and chemical mechanisms involved. Model cracks are a key step to study chemical and transport coupling in fractured media. Crack lixiviation in aggressive conditions (pH{>=}11) show that the crack's position (horizontal or vertical) determines the dominant transport mechanism (respectively diffusion or convection induced by gravity). This gravity driven flow seems to be negligible in lower pH conditions. The convective velocity is estimated by a 1D model of reactive transport. Two other parameters are studied: the influence of thermal gradient and the influence of interconnected cracks on alteration. A strong retroactive effect of convection, due to thermal gradient, on the alteration kinetic is observed inside the crack. These works lead to a complete alteration experiment of a 163 crack network subject to a thermal gradient. The use of the geochemical software, HYTEC, within the framework of this study shows the potential of the software which is however limited by the kinetics law used. (author)

  10. Uncertainty estimation and global forecasting with a chemistry-transport model - application to the numerical simulation of air quality; Estimation de l'incertitude et prevision d'ensemble avec un modele de chimie transport - Application a la simulation numerique de la qualite de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Mallet, V.

    2005-12-15

    The aim of this work is the evaluation of the quality of a chemistry-transport model, not by a classical comparison with observations, but by the estimation of its uncertainties due to the input data, to the model formulation and to the numerical approximations. The study of these 3 sources of uncertainty is carried out with Monte Carlo simulations, with multi-model simulations and with comparisons between numerical schemes, respectively. A high uncertainty is shown for ozone concentrations. To overcome the uncertainty-related limitations, a strategy consists in using the overall forecasting. By combining several models (up to 48) on the basis of past observations, forecasts can be significantly improved. This work has been also the occasion of developing an innovative modeling system, named Polyphemus. (J.S.)

  11. De l’idée au marché : l’ITERG renforce ses activités dans la chimie verte avec la plateforme CEDOP, Centre européen de développement des oléo-produits

    Directory of Open Access Journals (Sweden)

    Alfos Carine

    2012-01-01

    Full Text Available ITERG, the Industrial Technical Centre (CTI for Fats and Oils, under the supervision of the Ministry of Economy, Finance and Employment, located in Pessac has undertaken the project to build a technology platform (to be operational in early 2012 dedicated to innovation and transfer in the field of oleochemicals from experimental to semi-industrial scales. This platform, CEDOP (European Centre for the Development of Oleo-Products can offer within the same entity, expertise and scalability from laboratory to semi-industrial productions, to industrial manufacturers, processors, distributors and value chain actors of oleo-products. This project unique in its design, perfectly in tune with public policies for innovation and development of green chemistry, not only meets the needs of manufacturers and their markets but also the current socio-economic expectations in terms of environment and sustainable development. The CEDOP project total investment reached 8,700,000 € [buildings (laboratories, industrial and pilot halls, technical offices and equipment]. After the positive results of preliminary studies (competition, market research, risk assessment and the inclusion of CEDOP in the “State-Aquitaine Region Contract of Projects”, public institutions (Regional Council, State, FEDER, local and professional organization (ONIDOL brought together 85% of the project funding. Such a support reflects the confidence of the stakeholders in ITERG’s independent entrepreneurial skills in scientific and technology to meet public and professional policies, but above all in the large scope of corporate customers from different sectors of activity, potential future users of the tool. This project for research and technology transfer is fully integrated in ITERG’s development and diversification strategies and aims to develop an attractive lipochemistry-technology cluster.

  12. Application of colloidal chemistry in aqueous phase to the preparation of supported metallic catalysts: particles size and aggregation control; Application de la chimie colloidale en phase aqueuse a la preparation de catalyseurs metalliques supportes: controle de la taille et de l`etat d`agregation des particules

    Energy Technology Data Exchange (ETDEWEB)

    Pages, T.

    1998-09-16

    This work is an application of colloidal chemistry in aqueous phase on supported metal catalyst preparation. The objective is the control of particle size and aggregation. The preparation of the materials was achieved in two steps: - the synthesis of PdO hydrosols was obtained by two ways: neutralisation of the solution containing metallic salt by adding alkaline solution or by thermo-hydrolysis; the sols were then deposited on carriers (Al{sub 2}O{sub 3}, SIO{sub 2}). The use of partial charge model allowed us to determine the complexes that were able to generate PdO. The preparation of PdO from Pd(H{sub 2}O){sub 4}{sup 2+} was studied and a mechanism of oxide formation was elaborated. The neutralisation of Pd(H{sub 2}O){sub 4}{sup 2+} obtained by adding alkaline solution led to particles with an average size of 1.8 nm and a narrow particle size distribution. Only the thermo-hydrolysis of Pd(H{sub 2}O){sub 4}{sup 2+} led to particles which size is higher than 3.0 nm. In the last case, particle size is controlled by the precursor concentration (Pd(H{sub 2}O){sub 2}(OH){sub 2}) generated in the medium. We have demonstrated that particle aggregation in the sol depends on the Ph and the way of preparation. It can be controlled by adding complexing anions (Cl{sup -}, NO{sub 2}{sup -}). Concerning the deposition of sols on carriers, it led to isolated or aggregated particles according to experimental conditions. Particle size was not modified during the deposition. Moreover, in our experimental conditions, reduction of particles did not modify particle size and aggregation. An application of this original way of preparation on catalysis allowed us to demonstrate the interest of controlling particle size and aggregation. (author) 186 refs.

  13. TEM characterisation of stress corrosion cracks in nickel based alloys: effect of chromium content and chemistry of environment; Caracterisation par MET de fissures de corrosion sous contrainte d'alliages a base de nickel: influence de la teneur en chrome et de la chimie du milieu

    Energy Technology Data Exchange (ETDEWEB)

    Delabrouille, F

    2004-11-15

    Stress corrosion cracking (SCC) is a damaging mode of alloys used in pressurized water reactors, particularly of nickel based alloys constituting the vapour generator tubes. Cracks appear on both primary and secondary sides of the tubes, and more frequently in locations where the environment is not well defined. SCC sensitivity of nickel based alloys depends of their chromium content, which lead to the replacement of alloy 600 (15 % Cr) by alloy 690 (30 % Cr) but this phenomenon is not yet very well understood. The goal of this thesis is two fold: i) observe the effect of chromium content on corrosion and ii) characterize the effect of environment on the damaging process of GV tubes. For this purpose, one industrial tube and several synthetic alloys - with controlled chromium content - have been studied. Various characterisation techniques were used to study the corrosion products on the surface and within the SCC cracks: SIMS; TEM - FEG: thin foil preparation, HAADF, EELS, EDX. The effect of chromium content and surface preparation on the generalised corrosion was evidenced for synthetic alloys. Moreover, we observed the penetration of oxygen along triple junctions of grain boundaries few micrometers under the free surface. SCC tests show the positive effect of chromium for contents varying from 5 to 30 % wt. Plastic deformation induces a modification of the structure, and thus of the protective character, of the internal chromium rich oxide layer. SCC cracks which developed in different chemical environments were characterised by TEM. The oxides which are formed within the cracks are different from what is observed on the free surface, which reveals a modification of medium and electrochemical conditions in the crack. Finally we were able to evidence some structural characteristics of the corrosion products (in the cracks and on the surface) which turn to be a signature of the chemical environment. (author)

  14. Uncertainty estimation and global forecasting with a chemistry-transport model - application to the numerical simulation of air quality; Estimation de l'incertitude et prevision d'ensemble avec un modele de chimie transport - Application a la simulation numerique de la qualite de l'air

    Energy Technology Data Exchange (ETDEWEB)

    Mallet, V

    2005-12-15

    The aim of this work is the evaluation of the quality of a chemistry-transport model, not by a classical comparison with observations, but by the estimation of its uncertainties due to the input data, to the model formulation and to the numerical approximations. The study of these 3 sources of uncertainty is carried out with Monte Carlo simulations, with multi-model simulations and with comparisons between numerical schemes, respectively. A high uncertainty is shown for ozone concentrations. To overcome the uncertainty-related limitations, a strategy consists in using the overall forecasting. By combining several models (up to 48) on the basis of past observations, forecasts can be significantly improved. This work has been also the occasion of developing an innovative modeling system, named Polyphemus. (J.S.)

  15. Chemistry 300. Administration Manual for Supervising Teachers, Provincial Examination, Answer Key--Multiple-Choice and Written-Answer Questions, and Provincial Summary Report = Chimie 300. Guide d'administration a l'intention des surveillants d'examen, Examen provincial, Cle de correction--Questions choix multiple et Questions responses ouvertes, et Rapport sommaire provincial.

    Science.gov (United States)

    Manitoba Dept. of Education and Training, Winnipeg.

    This collection of manuals contains the Manitoba Provincial Chemistry Examination for students seeking credit in Senior 4 Chemistry (Chemistry 300) and instructions for its use and grading. The examination is based on the Core Topics of the Senior 4 Chemistry course and accounts for 30% of the student's final grade in the course. The examination…

  16. Fiche pratique: Anaphores et enchainements; B. d. de Grand Vent; FDM Frequence plus: Une minute sur la mode; Chimie pour non-chimistes (Practical Ideas: Anaphors and Linking; The Comic Strip "Grand Vent"; One Minute on Fashion; Chemistry for Non-Chemists).

    Science.gov (United States)

    Baldovi, Josep Ramon Torres

    1994-01-01

    Ideas for French instruction are offered, including a grammar exercise on pronouns; exploration of a comic strip's language and culture; use of a taped program on fashion; and an activity to help French language teachers cope with unfamiliar discipline-specific texts, whose topics (but not language) are familiar to their students. (MSE)

  17. The understanding of the R7T7 glass blocks long term behavior: chemical and transport coupling in fractured media; Comprehension de l'alteration a long terme des colis de verre R7T7: etude du couplage chimie transport dans un milieu fissure

    Energy Technology Data Exchange (ETDEWEB)

    Chomat, L

    2008-04-15

    The long term behavior of nuclear waste glass blocks depends highly on chemical reactions which occur at the surface in contact with water. Studies carried out on inactive fractured glass blocks show that fracture networks play a significant part in reactive surface area. Nevertheless, the complexity of results interpretation, due to a weak knowledge of fracture networks and local lixiviation conditions, does not allow us to comprehend the physical and chemical mechanisms involved. Model cracks are a key step to study chemical and transport coupling in fractured media. Crack lixiviation in aggressive conditions (pH{>=}11) show that the crack's position (horizontal or vertical) determines the dominant transport mechanism (respectively diffusion or convection induced by gravity). This gravity driven flow seems to be negligible in lower pH conditions. The convective velocity is estimated by a 1D model of reactive transport. Two other parameters are studied: the influence of thermal gradient and the influence of interconnected cracks on alteration. A strong retroactive effect of convection, due to thermal gradient, on the alteration kinetic is observed inside the crack. These works lead to a complete alteration experiment of a 163 crack network subject to a thermal gradient. The use of the geochemical software, HYTEC, within the framework of this study shows the potential of the software which is however limited by the kinetics law used. (author)

  18. Synthesis of nano-particles by soft chemistry: structural, morphological and dimensional control. Studies of the electrochemical properties (towards dyes solar cells); Synthese de nanoparticules par chimie douce: controle structural, morphologique et dimensionnel. Etudes des proprietes electrochimiques (vers les cellules solaires a colorants)

    Energy Technology Data Exchange (ETDEWEB)

    Cassaignon, S.; Koelsch, M.; Jolivet, J.P. [Paris-6 Univ. Pierre et Marie Curie, Chimie de la Matiere Condensee de Paris, CNRS UMR 7574, 75 - Paris (France)

    2006-07-01

    In this work are described the electrochemical behaviour of different TiO{sub 2} films (anatase, brookite and rutile) in aqueous solution and the influence of the parameters as the crystal structure and the morphology on the electrochemical answer. To complete this study, the capacity of the double layer has been measured by impedance spectroscopy. Voltage measurements of TiO{sub 2} sensitized by a dye will allow to discuss the reversibility of the system and the rearrangement mechanisms. At last, the influence of the nature of the TiO{sub 2} particles (anatase, rutile and brookite) on the photovoltage has been studied in order to estimate their interest for photovoltaic devices. (O.M.)

  19. Methodological study of the diffusion of interacting cations through clays. Application: experimental tests and simulation of coupled chemistry-diffusion transport of alkaline ions through a synthetical bentonite; Etude methodologique de la diffusion de cations interagissants dans les argiles. Application: mise en oeuvre experimentale et modelisation du couplage chimie-diffusion d'alcalins dans une bentonite synthetique

    Energy Technology Data Exchange (ETDEWEB)

    Melkior, Th

    2000-07-01

    The subject of this work deals with the project of underground disposal of radioactive wastes in deep geological formations. It concerns the study of the migration of radionuclides through clays. In these materials, the main transport mechanism is assumed to be diffusion under natural conditions. Therefore, some diffusion experiments are conducted. With interacting solutes which present a strong affinity for the material, the duration of these tests will be too long, for the range of concentrations of interest. An alternative is to determine on one hand the geochemical retention properties using batch tests and crushed rock samples and, on the other hand, to deduce the transport parameters from diffusion tests realised with a non-interacting tracer, tritiated water. These data are then used to simulate the migration of the reactive elements with a numerical code which can deal with coupled chemistry-diffusion equations. The validity of this approach is tested by comparing the numerical simulations with the results of diffusion experiments of cations through a clay. The subject is investigated in the case of the diffusion of cesium, lithium and sodium through a compacted sodium bentonite. The diffusion tests are realised with the through-diffusion method. The comparison between the experimental results and the simulations shows that the latter tends to under estimate the propagation of the considered species. The differences could be attributed to surface diffusion and to a decrease of the accessibility to the sites of fixation of the bentonite, from the conditions of clay suspensions in batch tests to the situation of compacted samples. The influence of the experimental apparatus used during the diffusion tests on the results of the measurement has also been tested. It showed that these apparatus have to be taken into consideration when the experimental data are interpreted. A specific model has been therefore developed with the numerical code CASTEM 2000. (author)

  20. Preliminary experiments on the use of radioactive indicators in macromolecular chemistry; Experiences preliminaires sur l'utilisation des indicateurs radioactifs en chimie macromoleculaire; Predvaritel'nye opyty ispol'zovaniya radioaktivnykh indikatorov v makromolekulyarnoj khimii; Ensayos preliminares sobre el empleo de indicadores radiactivos en quimica macromolecular

    Energy Technology Data Exchange (ETDEWEB)

    De Brouckere, L; Van Leemput, R; Stein, R [Laboratoire de Chimie Generale II, Universite Libre de Bruxelles (Belgium)

    1962-03-15

    In studies of osmotic phenomena with high polymers, two causes of error are particularly important: (a) Diffusion of low-molecular-weight polymers across the membrane; (b) Polymer adsorption on the membrane. For investigations on both these phenomena radiotracer methods present decisive advantages over the classical and far less sensitive gravimetric procedures. The polymer used in the authors' experiments was a hetero-disperse sample of (poly) chloro-butyl acrylate which was ionically chlorinated with Cl{sup 36} starting from a sample of (poly)butyl acrylate. This polymer was dissolved in acetone. Diffusion chambers similar to twin-cell osmometers were set up. Cellophane membranes with permeabilities of 6.7 x 10{sup -5} h{sup -1} to 30.6 x 10{sup -5} h{sup -1} separated the solution from the solvent. It was found that: (a) With our apparatus, about two hundred hours were necessary to reach an equilibrium or steady state in diffusion experiments; (b) The fraction of polymer diffusing through the membrane in a given time was independent of the concentration; (c) The amount of polymer diffusing was related to the permeability of the membrane; (d) A practically irreversible adsorption of polymer on the membrane was observed (30 to 40 {mu}g/cm{sup 2}). (author) [French] Dans les etudes sur les phenomenes osmotiques avec de hauts polymeres, deux causes d'erreurs sont particulierement importants : a) La diffusion des polymeres de faible poids moleculaire a travers la membrane; b) L'adsorption des polymeres sur la membrane. Pour les recherches sur ces deux phenomenes, la methode des radiotraceurs presente des avantages decisifs par rapport aux procedes gravi metriques classiques, beaucoup moins sensibles. Le polymere utilise dans les experiences des auteurs etait un echantillon a dispersion heterogene acrylate de (poly) chloro-butyle, obtenu par chlorruation ionique d'un echantillon d'acrylate de (poly)butyle avec du chlore-36. Ce polymere etait dissous dans de l'acetone. On a utilise des chambres de diffusion analogues aux osmometres a cellules jumelles. Des membranes de cellophane de permeabilite 6,7 {center_dot} 10{sup -5} h{sup -1} a 30,6 {center_dot} 10{sup -5} h{sup -1} separaient la solution du solvant. On a constate: a) Qu'avec l'appareil utilise dans les experiences de diffusion, il fallait environ deux cents heures pour atteindre un etat d'equilibre ou un etat stationnaire; b) Que la fraction de polymere se diffusant a travers la membrane dans un temps donne etait independante de la concentration; c) Que la quantite de polymere diffuse variait en fonction de la permeabilite de la membrane; d) Qu'il se produisait une adsorption pratiquement irreversible du polymere sur la membrane (30 a 40 {mu}g/cm{sup 2}). (author) [Spanish] Las dos principales fuentes de error cuando se estudian fenomenos osmoticos con polimeros de elevado peso molecular son: a) la difusion de polimeros de bajo peso molecular a traves de la membrana; b) la adsorcion de polimeros en la membrana. Los metodos que emplean trazadores radiactivos para la investigacion de estos dos fenomenos ofrecen ventajas decisivas sobre los procedimientos gravimetricos clasicos, que son mucho menos sensibles. El polimero empleado por los autores consistio en una muestra heterodispersa de policloroacrilato de butilo obtenido por el oracion ionica del poliacrilato de butilo con {sup 36}Cl. Este polimero se utilizo disuelto en acetona. Los autores emplearon camaras de difusion, semejantes a osmomotros de celulas gemelas. La solucion quedaba separada del disolvente por membranas de celofan de permeabilidades de 6,7 x 10{sup -5} h{sup -1} a 30,6 x 10{sup -5} h{sup -1}. Han llegado a las conclusiones siguientes: a) con el aparato empleado en los experimentos de difusion, se precisan unas 200 horas para alcanzar un estado de equilibrio o un regimen estacionario; b) la fraccion de polimero que difunde a traves de la membrana en un tiempo determinado es independiente de la concentracion; c) la cantidad de polimero que se difunde depende de la permeabilidad de la membrana; d) se observa una adsorcion practicamente irreversible del polimero en la membrana (30 a 40 {mu}g cm{sup 2}). (author) [Russian] Pri izuchenii osmoticheskikh yavlenij s ispol'zovaniem vysokikh polimerov osoboe znachenie predstavlyayut dve prichiny oshibok: a) diffuziya nizkomolekulyarnykh polimerov cherez membranu; b) adsorbtsiya polimera na membrane. Dlya issledovaniya oboikh ehtikh yavlenij metod radioaktivnykh indikatorov predstavlyaet nesomnennye preimushchestva nad obychnymi i gorazdo menee chuvstvitel'nymi vesovymi metodami. V provedennykh avtorami doklada opytakh byl ispol'zovan geterodispersnyj obrazets polimera (poli)-khlorobutilakrilata, kotoryj byl khlorirovan s pomoshch'yu Cl{sup 36} posredstvom ionizatsii, iskhodya iz obraztsa (poli)-butilakrilata. Ehtot polimer rastvo- ryaetsya v atsetone. Byli postroeny diffuzionnye kamery, analogichnye dvuyacheechnym osmometram. Rastvor otdelyalsya ot rastvoritelya tselofanovymi membranami, obrabotannymi tak, chtoby davat' pronitsaemost' ot 6,7 x 10{sup -5} ch{sup -1} do 30,6 x 10{sup -5} ch{sup -1} Bylo najdeno, chto: a) s nashim oborudovaniem ponadobilos' okolo 200 chasov dlya togo, chtoby v opytakh diffuzii dostich' ravnovesiya ili ustojchivogo sostoyaniya; b) dolya polimera, diffundiruyushchaya cherez membranu v opredelennyj promezhutok vremeni, ne zavisit ot kontsentratsii; c) kolichestvo diffundiruyushchego polimera zavisit ot pronitsaemosti membrany; d) nablyudalas' pochti neobratimaya adsorbtsiya polimera na membrane (30-40 {mu}g/cm{sup 2}). (author)

  1. Radioisotopes in the physical chemistry of corrosion processes and their inhibition; Les radioisotopes dans la chimie physique des processus de corrosion et de leur inhibition; Primenenie radioizotopov v fizicheskoj khimii protsessov korrozii i ikh tormozheniya; Los radioisotopos en la quimica fisica de los procesos de corrosion y de inhibicion

    Energy Technology Data Exchange (ETDEWEB)

    Cartledge, G H [Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-03-15

    The fundamental study of the electrochemical processes of corrosion and inhibition involves various factors, including in particular: (a) adsorption phenomena of different types; (b) ion-exchange properties of passive films; and (c) the electrochemical kinetics of both anodic and cathodic processes across the interface between a metal and its corrosive environment. The availability of radioisotopes has made possible certain studies of these phenomena that could not be made previously with conventional techniques. The element technetium, a homologue of manganese in the periodic system, has been found uniquely suited to certain of these studies by reason of its nuclear properties. The chemical properties of technetium compounds are summarized and contrasted with those of corresponding Cr{sup 51} compounds and those of molybdenum and tungsten, so much used in studies of inhibition. Selected experimental studies are given as examples of the uses to which technetium has already been put in this type of work. Among these are empirical studies of its action as a very efficient inhibitor of the corrosion of iron, together with the results of long-term observations of surface activity. Other studies with both Tc{sup 99} and I{sup 131} have demonstrated the significance of competitive adsorption of ions in the determination of the kinetics of the corrosion and inhibitory processes. Finally, the author shows how the unique properties of technetium have permitted a clear discrimination between the relative contributions of oxygen and the oxidizing inhibitor in the maintenance of passivity. (author) [French] Parmi les facteurs qui entrent en jeu dans l'etude fondamentale des processus electrochimiques de corrosion et d'inhibition on releve notamment: a) differents types de phenomenes d'adsorption; b) les proprietes d'echange ioniques des films passifs; c) la cinetique electrochimique des processus tant anodiques que cathodiques qui se produisent dans l'interface entre un metal et le milieu corrosif. Avec les radioisotopes, on peut maintenant entreprendre sur ce sujet certaines recherches impossibles avec les moyens classiques. Le technetium, homologue du manganese dans la classification periodique, s'est revele l'element de choix pour certaines de ces recherches. Ses proprietes nucleaires sont extremement interessantes a cet egard. Le memoire resume les proprietes chimiques des composes du technetium, qu'il oppose a celles des composes correspondants du chrome-51, ainsi qu'a celles du molybdene et du tungstene, d'usage repande dans les recherches sur l'inhibition. L'auteur decrit ensuite quelques etudes experimentales a titre d'exemples des emplois que le technetium a deja trouves dans les travaux de ce genre. Il mentionne notamment certains etudes empiriques sur l'action du technetium en tant qu'inhibiteur tres efficace de la corrosion du fer, ainsi que les resultats d'observations faites pendant une longue periode sur l'activite de surface. D'autres recherches au moyen du technetium-99 et de l'iode-131 ont montre l'importance de l'adsorption competitive d'ions dans l'etude cinetique des processus de corrosion et d'inhibition. Enfin l'auteur mentre comment les proprietes speciales du technetium ont permis de faire une distinction nette entre la part de l'oxygene et celle de l'inhibiteur oxydant dans le maintien de la passivite. (author) [Spanish] Algunos de los factores que intervienen, en los estudios fundamentales de los procesos electroquimicos de corrosion e inhibicion son los siguientes: a) fenomenos de adsorcion de diversos tipos, b) propiedades de intercambio ionico de las peliculas pasivas, y c) la cinetica electroquimica de los procesos anodicos y catodicos que tienen lugar en la fase que separa un metal del medio corrosivo. Los radioisotopos han hecho posible ciertos estudios de estos fenomenos que antes no podian llevarse a cabo con los metodos clasicos. Se ha comprobado que el tecnecio, tm homologo dol manganeso en el sistema periodico, es particularmente adecuado para algunos de estos estudios. Las ventajas do este elemento estriban, en sus propiedades nucleares. La memoria resume las propiedades quimicas de los compuestos de tecnecio y las compara con las de los compuestos correspondientes de {sup 51}Cr, de molibdeno y de wolframio, que con tanta frecuencia se emplean en el estudio de la inhibicion. La memoria describe seguidamente ciertos estudios experimentales como ejemplo de los usos a que se ha destinado el tecnecio en los trabajos de este tipo. Entre ellos menciona estudios empiricos de su accion como eficaz inhibidor de la corrosion del hierro, y observaciones de la actividad de superficie realizadas durante periodos largos de tiempo. Otros estudios efectuados con {sup 99}Tc y con {sup 131}I han demostrado la importancia de la adsorcion competitiva de iones en la determinacion de la cinetica de los procesos de corrosion y de inhibicion. Como tercer ejemplo, describe como las propiedades excepcionales del tecnecio han permitido distinguir claramente las contribuciones relativas del oxigeno de las del inhibidor oxidante en el mantenimiento de la pasividad. (author) [Russian] Sredi faktorov, vkhodyashchikh v fundamental'noe izuchenie ehlektrokhimicheskikh protsessov korrozii i tormozheniya, vydelyayutsya v chastnosti sleduyushchie: a) razlichnye vidy adsorbtsionnykh yavlenij; b) ionoobmennye svojstva passivnykh plenok; c) ehlektrokhimicheskaya kinetika kak anodnykh, tak i katodnykh protsessov, proiskhodyashchikh mezhdu metallom i korrozijnoj sredoj. Teper' pri pomoshchi radioizotopov mozhno provesti nekotorye issledovaniya ehtikh yavlyaenij, kotorye nevozmozhno osushchestvit' obychnymi sredstvami. Tekhnetsij, gomolog margantsa v periodicheskoj sisteme, okazalsya ves'ma podkhodyashchim dlya nekotorykh ehtikh issledovanij. Ego yadernye svojstva krajne interesny u ehtom otnoshenii. V doklade kratko izlagayutsya khimicheskie svojstva soedinenij tekhnetsiya, protivopostavlennye svojstvam sootvetstvuyushchikh soedinenij khroma-51, molibdena i vol'frama, obychno ispol'zuyushchikhsya pri izuchenii protsessov tormozheniya. Dalee avtor opisyvaet nekotorye ehksperimental'nye issledovaniya v kachestve primerov ispol'zovaniya tekhnetsiya v rabotakh podobnogo roda. V chastnosti, on upominaet nekotorye ehmpiricheskie issledovaniya dejstviya tekhnetsiya kak ves'ma ehffektivnogo sredstva tormozheniya korrozii zheleza, a takzhe rezul'taty mnogochislennykh nablyudenij nad aktivnost'yu poverkhnosti. Drugie issledovaniya pri pomoshchi kak tskhnstsiya-99, tak i joda-131 pokazali vazhnost' sravnitel'noj adsorbtsii ionov v kineticheskom izuchenii protsessov korrozii i tormozheniya. Nakonets, avtor pokazyvaet, kak osobye svojstva tekhnetsiya pozvolili provesti chetkoe razgranichenie mezhdu dolej kisloroda i dolej zamedlitelya okisleniya pri sokhranenii passivnosti. (author)

  2. TEM characterisation of stress corrosion cracks in nickel based alloys: effect of chromium content and chemistry of environment; Caracterisation par MET de fissures de corrosion sous contrainte d'alliages a base de nickel: influence de la teneur en chrome et de la chimie du milieu

    Energy Technology Data Exchange (ETDEWEB)

    Delabrouille, F

    2004-11-15

    Stress corrosion cracking (SCC) is a damaging mode of alloys used in pressurized water reactors, particularly of nickel based alloys constituting the vapour generator tubes. Cracks appear on both primary and secondary sides of the tubes, and more frequently in locations where the environment is not well defined. SCC sensitivity of nickel based alloys depends of their chromium content, which lead to the replacement of alloy 600 (15 % Cr) by alloy 690 (30 % Cr) but this phenomenon is not yet very well understood. The goal of this thesis is two fold: i) observe the effect of chromium content on corrosion and ii) characterize the effect of environment on the damaging process of GV tubes. For this purpose, one industrial tube and several synthetic alloys - with controlled chromium content - have been studied. Various characterisation techniques were used to study the corrosion products on the surface and within the SCC cracks: SIMS; TEM - FEG: thin foil preparation, HAADF, EELS, EDX. The effect of chromium content and surface preparation on the generalised corrosion was evidenced for synthetic alloys. Moreover, we observed the penetration of oxygen along triple junctions of grain boundaries few micrometers under the free surface. SCC tests show the positive effect of chromium for contents varying from 5 to 30 % wt. Plastic deformation induces a modification of the structure, and thus of the protective character, of the internal chromium rich oxide layer. SCC cracks which developed in different chemical environments were characterised by TEM. The oxides which are formed within the cracks are different from what is observed on the free surface, which reveals a modification of medium and electrochemical conditions in the crack. Finally we were able to evidence some structural characteristics of the corrosion products (in the cracks and on the surface) which turn to be a signature of the chemical environment. (author)

  3. Late Devonian (Famennian) Glaciation in south America and marine offlap on other continents

    Czech Academy of Sciences Publication Activity Database

    Isaacson, P. E.; Hladil, Jindřich; Jian-Wei, S.; Kalvoda, J.; Grader, G.

    1999-01-01

    Roč. 54, - (1999), s. 239-257 ISSN 0016-7800 R&D Projects: GA ČR GA205/98/1347; GA AV ČR IAA3013809; GA ČR GA205/96/0137 Grant - others:XX(XC) IGCP421 Institutional research plan: CEZ:AV0Z3013912 Subject RIV: DA - Hydrology ; Limnology http://www.geologie.ac.at/filestore/download/AB0054_239_A.pdf

  4. Visuelles in der wissenschaftlichen Kommunikation - z.B. Betrug und Fälschung

    OpenAIRE

    Fröhlich, Gerhard

    2003-01-01

    Visuelle Phänomene sind oft beim Aufdecken wissenschaftlichen Betrugs involviert. Wissenschaftliche und Massenmedien berichten von "vierdimensionalen" (Flusser) Manipulationen in Laboratorien (Moewus, Parapsychologie, Beneviste), "dreidimensionalen" Artefakten in Archäologie bzw. Geologie ("Lügensteine", Piltdown, Fujimura) und Biologie bzw. Medizin (Kammerers getuschte Geburtshelferkröte, Summerlins bemalte Mäuse, Illmensees Bluff-Klone). Inkriminierte zweidimensionale Repräsentationen (Bild...

  5. Geochronology and magnetic fabrics of the Altenberg-Teplice granite porphyry: implications for emplacement style of a caldera ring dike

    Czech Academy of Sciences Publication Activity Database

    Tomek, Filip; Žák, J.; Svojtka, Martin

    2016-01-01

    Roč. 46 (2016), s. 39-40 E-ISSN 1434-7512. [Late Paleozoic magmatism in the Erzgebirge / Krušné hory: Magma genesis, tectonics, geophysics, and mineral deposits : abstracts. 11.11.2016-12.11.2016, Freiberg] Institutional support: RVO:67985831 Keywords : porphyry * magnetic fabrics * geochronology * Altenberg-Teplice Subject RIV: DB - Geology ; Mineralogy http://tu-freiberg.de/sites/default/files/media/institut-fuer-geologie-718/pdf/fog_volume_46.pdf

  6. Experience with remediation implementation at railroad station Freital-Potschappel

    International Nuclear Information System (INIS)

    Streubel, G.; Tottewitz, K.

    1995-01-01

    As a result of the measuring activities for the contaminated sites cadastre, the Saxonian Landesamt fuer Umwelt und Geologie requested the Deutsche Bahn AG as the responsible site owner to clean up the radioactively contaminated surfaces open to the general public. In response, the Deutsche Bahn AG commissioned the TUeV Sachsen GmbH to carry out the remediation work. The lecture reports on aspects of main interest and experience obtained in these activities. (orig./DG) [de

  7. Le problème des hydrates dans le contexte de la production et du transport polyphasiques des pétroles bruts et des gaz naturels. Première partie : physico-chimie de la formation et de la dissociation des hydrates Hydrates Problem Within the Framework of Multiphase Production and Transport of Crude Oils and Natural Gases. Part One: Physical-Chemistry of Hydrates Formation and Dissociation

    Directory of Open Access Journals (Sweden)

    Behar E.

    2006-11-01

    Full Text Available L'exploitation en mer des gisements de combustibles fossiles fluides a amplifié le besoin d'accroître nos connaissances sur les hydrates qui sont susceptibles de boucher les installations de production, de traitement et de transport. Dans cette publication, la structure moléculaire des hydrates I, II et H est rappelée, ensuite l'analyse physico-chimique de leur formation est succinctement décrite tant sur les plans thermodynamique que cinétique. Enfin, les remèdes possibles aux problèmes rencontrés par les compagnies opératrices sont indiqués, essentiellement les inhibiteurs thermodynamiques classiques tels que les alcools ou les sels qui diminuent la température de formation des hydrates, et les additifs dispersants qui évitent la croissance et/ou l'agglomération des cristaux. Pour terminer, une boucle pilote de circulation originale est présentée, ses caractéristiques qui permettent la validation des additifs dispersants dans des conditions hydrodynamiques et physico-chimiques représentatives étant soulignées. Offshore exploitation of fossil fluid fuels has emphasized the need of improving our knowledge on hydrates which can plug production, treatment and transport facilities. In this paper, the molecular structure of I, II and H hydrates is recalled, then the physical-chemistry of their formation is briefly reviewed from both the thermodynamic and the kinetic points of view. Finally, the possible remedies to the problems met by operating companies are described, mainly classical thermodynamic inhibitors such as alcohols or salts which decrease the hydrates formation temperature, and dispersant additives which avoid crystals growth and/or agglomeration. At last an original circulation loop at pilot scale is presented, its characteristics which allow the testing of dispersant additives under representative hydrodynamic and physico-chemical conditions being outlined.

  8. Macromolecules and Enzymes: The Geneva Heritage from Kurt H. Meyer and Edmond H. Fischer.

    Science.gov (United States)

    Fischer, Edmond H; Piguet, Alfred

    2009-12-01

    On the 26th May 2009, Edmond Fischer, winner with Ed Krebs of the Nobel prize in physiology or medicine in 1992, and his colleague at the time of his research activities at the Ecole de chimie of the University of Geneva, Alfred Piguet, met with Andreas Hauser, Claude Piguet and Howard Riezman of the Section de chimie et biochimie of the University of Geneva to talk about how they became scientists under the impetus of Kurt H. Meyer and what became of them thereafter.

  9. Nuclear warfare

    CERN Document Server

    Broda

    1981-01-01

    Le Prof.Broda a étudié à Vienne et Berlin et a travaillé pendant la dernière guerre mondiale en Grande Bretagne pour le conseil de la recherche médicale, notamment sur la chimie de la vision. Il est maintenant Prof. de la chimie, physique et radiochimie à l'Université de Vienne, où il concentre ses travaux sur les méchanisme de transport d'énergie à travers les cellules de membranes.

  10. Interview: Sued-Chemie innovates to maintain its leadership; Interview Sued-Chemie: innover pour conserver son leadership

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2000-01-01

    The Sued-Chemie group, the head office of which is based in Munich, is one of the world's leading producers of catalysts for the 'syngas' gas chemistry, the refining and the petrochemical industry. Questioned by Info Chimie Magazine, Stefan Brejc, the Product Manager for 'syngas' catalysts, reviews the products in the range. (authors)

  11. Hydrogen: Water, Sun and Catalysts

    Indian Academy of Sciences (India)

    MF136409

    Laboratoire de Chimie et Biologie des Métaux, Université Joseph Fourier, CNRS, CEA/DSV/iRTSV ... Limitation of the emission of green-house effect CO. 2 . Limitation ..... CO2. Pc. P680. Qa. P700. PSII cytb6. NADPH. O2 +. 4 H+. 2 H2O. FNR.

  12. 135 Suivi de la qualité physico-chimique et bactériologique des ...

    African Journals Online (AJOL)

    ZIGLA

    1Laboratoire de Chimie des Eaux, des Sols et Environnements, Ecole Nationale ... des caractéristiques physico-chimiques et biologiques du biotope [2-4]. ..... les engrais utilisés pour l'agriculture pratiquée le long des cours d'eau et de.

  13. 1846-IJBCS-Article-Koffi Akpagana

    African Journals Online (AJOL)

    hp

    Diversité des espèces cultivées et contraintes à la production en agriculture maraîchère au ... 2 Laboratoire de Chimie des Eaux, Faculté des Sciences, Université de Lomé, BP 1515, Lomé, Togo. ..... Techniques Biologiques et Alimentaires,.

  14. benzimidazole metal complexes

    Indian Academy of Sciences (India)

    aUnité de Recherche de Chimie de l'Environnement et Moléculaire Structurale, Université des Frères. Mentouri .... determine the quantum chemical parameters for the title ..... retical study of benzazole thioether and its zinc complex.

  15. Évaluation de la cytogénotoxicité des sites de pollution du PONT et ...

    African Journals Online (AJOL)

    SARAH

    31 mars 2015 ... pollution du PONT et d'ACCRON de la lagune de Porto-. Novo. CAKPO R. Arthur1, SAGBO Etienne1, MAMA Daouda2, SOUMANOU M. Mohamed3. 1Laboratoire de Chimie .... que le cancer, athérosclérose, les maladies.

  16. Journal of Chemical Sciences | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    LCAE, Département de Chimie, Faculté des Sciences, Université Mohammed Premier, Oujda 60000, Morocco; Institut de Physique de Rennes, UMR 625, Université de Rennes 1, Campus de Beaulieu Bat. 11 A, 263 av. Général Leclerc, 35042 Rennes Cedex, France; Department of Chemistry, University of Science ...

  17. 15-00115_SI_NP.doc

    Indian Academy of Sciences (India)

    SAID TIGHADOUINI1, SMAAIL RADI*,1, LOIC TOUPET2, MUHAMMAD SIRAJUDDIN*,3, TAIBI BEN HADDA*,4, MEHMET AKKURT5, ISMAIL WARAD6, YAHIA MABKHOT7 and SAQIB ALI8. 1LCAE, Département de Chimie, Faculté des Sciences, Université Mohammed Premier, Oujda 60000, Morocco. 2Institut de Physique ...

  18. Incorporation of fluorophosphate into zinc–aluminium–nitrate ...

    Indian Academy of Sciences (India)

    Laboratoire de Chimie Biomoléculaire, Substances Naturelles et Réactivités, Unité des Matériaux, Faculté des Sciences Semlalia, Université Cadi Ayyad, BP 2390, Marrakech 40000, Morocco; Centre des Classes Préparatoires Ibnou Taimya, Route d'Essaouira, Marrakech 40000, Morocco; School of Science and ...

  19. Untitled

    African Journals Online (AJOL)

    Department of Organic Chemistry, University of Yaounde 1, BP 812 Yaounde, Cameroon. * * * Laboratoire de Chimie URA, 401 CNRS, ... yielded 9 mg of light yellow crystals: 5-hydroxy-4,7-dimethoxyisoflavone (6) crystals, ... Doddrell, D.M.; Pegg, B.T. and Bendall, M.R.,. (1982), "Nuclear Spin Relaxation in Liquids and.

  20. Bulletin of Materials Science | Indian Academy of Sciences

    Indian Academy of Sciences (India)

    Laboratoire d'Etude des Surfaces et Interfaces de la Matière Solide (LESIMS), Université Badji Mokhtar, 23000 Annaba, Algeria; Institut de Chimie (UMR 7177, CNRS-Unistra), Université de Strasbourg, 1 rue Blaise Pascal, CS 90032, 67081 Strasbourg Cedex, France; French EPR Federation of Research (REseau NAtional ...

  1. 2431-IJBCS-Article -Dougna Akpene A

    African Journals Online (AJOL)

    hp

    Physico-chimie et qualité des eaux des forages d'hydraulique villageoise dans la région ... Mots clés : Région centrale, Togo, faciès hydrochimiques, pollution, eaux souterraines, socle. Physical ...... total) ont un pH< 6 et présentent des indices.

  2. [Chemists and chemistry in the Journal of Medicine, Surgery, Pharmacy &c., from 1754 until 1791].

    Science.gov (United States)

    Fournier, Josette

    2006-01-01

    Since its coming out (1754) until the publication of the Annales de chimie (1789), the Journal de Médecine, Chirurgie, Pharmacie, &c. received papers and pieces of news from chemists; many of them cultivated their love for chemistry while they practised health professions.

  3. Ultrasound effects.

    Science.gov (United States)

    Martin, A O

    1985-07-19

    In a listing of the new foreign associates of the National Academy of Sciences (News and Comment, 17 May, p. 826), the name of Pierre Chambon, Biochemistry, Institut de Chimie Biologique, Faculté de Médecine, Strasbourg, France, was inadvertently omitted.

  4. Alumni Profiles.

    Science.gov (United States)

    Nitschke, Jonathan R; Quattropani, Anna; Corminboeuf, Clémence; Velonia, Kelly; Wilkinsoe, Kevin J; Kubel, Frank

    2009-12-01

    Former PhD students, post-docs and junior researchers of the Section de chimie et biochimie now holding positions at different universities and private companies remember the time they spent in Geneva and give an account of how this has set off and influenced their careers.

  5. Évaluation des propriétés antimicrobiennes des javels vendues à ...

    African Journals Online (AJOL)

    SARAH

    31 janv. 2016 ... 2 : Laboratoire de Chimie des Eaux, Facultés des Sciences (FDS) ... Evaluation of the antimicrobial properties of bleaches sold in Lomé on some bacteria ... Materials and Methods: This consisted of microbiological analysis of ...

  6. Chemistry for DUMMIES: how to popularize and introduce chemistry to the general public.

    Science.gov (United States)

    Montangero, Marc

    2012-01-01

    To mark the occasion of the International Year of Chemistry, each week in 2011 I posted a two-minute film demonstrating and explaining a simple and safe experiment to be carried out at home using everyday household products on the site www.chimie.ch/nuls.

  7. Redox ratio and optical absorption of polyvalent ions in industrial ...

    Indian Academy of Sciences (India)

    WINTEC

    Co2+ ions are not affected by their concentration but de- pend directly on glass ... This means that the coordination of these ions, octahedral sites for Mn3+, Cu2+ and .... Duffy J A and Ingram M D 2002 C.R. Chimie 5 797. Jones A R, Winter R, ...

  8. 4. Elmorchid.pmd

    African Journals Online (AJOL)

    chifaou.amzat

    9 août 2011 ... L'interaction entre l'économie solidaire et l'espace public suscite de plus en ..... essentiellement de l'agro-industrie, de la chimie et de la parachimie. .... Nous remarquons également l'absence de coordination entre les ...

  9. 2299-IJBCS-Article-Roger Niebié

    African Journals Online (AJOL)

    hp

    1Département Substances Naturelles/IRSAT/CNRST, 03 BP 7047 Ouagadougou 03, Burkina Faso. 2 Laboratoire de Chimie Organique et de ... 2000) ainsi que les risques de maladies cardio- vasculaires (Riccioni, 2009). La production ... obtenus par séchage naturel à l'ombre au laboratoire pendant sept (07) jours, soit à.

  10. 1090-IJBCS-Article-Fatiha Zidane

    African Journals Online (AJOL)

    DR GATSING

    1Laboratoire Science de l'Eau et d'Environnement, Département de Chimie, Faculté des Sciences Ain Chock,. Université ... élevée en divers types de polluants. ... Mots clés: traitement, hydroxyde, coagulation, demande chimique en oxygène.

  11. new polythiophenes with oligo(oxyethylene) side chains

    African Journals Online (AJOL)

    USER

    aDepartment of Chemistry, Faculty of Science, University of Douala, P.O. Box 24157, Douala,. Cameroon. bLaboratoire de Chimie des Substances Naturelles, USM 0502 MNHN - UMR 5154 CNRS, 63 rue Buffon-75005 Paris, France. cDepartment of Organic Chemistry, Faculty of Science, University of Yaounde I, P.O. Box ...

  12. etude physico-chimique et parasitologique des eaux usees

    African Journals Online (AJOL)

    AISA

    pollution ont été relativement faibles, comparativement à la moyenne des concentrations habituellement rencontrées pour les ... Mots clés : Pollution, eaux usées, physico-chimie, Helminthes, lac Fouarat, Maroc. ...... Paris, 1383 p. SDNAL.

  13. DGMK spring meeting of the 'Exploration and Production' department. Authors' manuscripts; DGMK-Fruehjahrstagung des Fachbereichs 'Aufsuchung und Gewinnung'. Autorenmanuskripte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The spring meeting of the Deutsche Wissenschaftliche Gesellschaft fuer Erdoel, Erdgas und Kohle e.V. focused on exploration and production. Papers were presented on exploration and production in general, geology, deposit development, extraction of petroleum/natural gas, drilling, underground storage, geophysics and geochemistry. [German] Die Fruehjahrstagung der Deutschen Wissenschaftlichen Gesellschaft fuer Erdoel, Erdgas und Kohle e.V. wurde vom Fachbereich ''Aufsuchung und Gewinnung'' bestimmt. Die Vortraege beschaeftigten sich mit den Gebieten Exploration and Production allgemein, Geologie, Lagerstaettentechnik, Foerdertechnik fuer Erdoel/Erdgas, Bohrtechnik, Untertagesspeichertechnik, Geophysik und Geochemie.

  14. Vertical evolution of the Cínovec granite cupola – chemical and mineralogical record

    Czech Academy of Sciences Publication Activity Database

    Breiter, Karel

    2016-01-01

    Roč. 46 (2016), s. 4-6 E-ISSN 1434-7512. [Late Paleozoic magmatism in the Erzgebirge / Krušné hory: Magma genesis, tectonics, geophysics, and mineral deposits : abstracts. 11.11.2016-12.11.2016, Freiberg] R&D Projects: GA ČR GA14-13600S Institutional support: RVO:67985831 Keywords : granite * Cínovec * geology * mineralogy * geochemistry Subject RIV: DB - Geology ; Mineralogy http://tu-freiberg.de/sites/default/files/media/institut-fuer-geologie-718/pdf/fog_volume_46.pdf

  15. DGMK spring meeting of the 'Exploration and Production' department. Authors' manuscripts; DGMK-Fruehjahrstagung des Fachbereichs 'Aufsuchung und Gewinnung'. Autorenmanuskripte

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    The spring meeting of the Deutsche Wissenschaftliche Gesellschaft fuer Erdoel, Erdgas und Kohle e.V. focused on exploration and production. Papers were presented on exploration and production in general, geology, deposit development, extraction of petroleum/natural gas, drilling, underground storage, geophysics and geochemistry. [German] Die Fruehjahrstagung der Deutschen Wissenschaftlichen Gesellschaft fuer Erdoel, Erdgas und Kohle e.V. wurde vom Fachbereich ''Aufsuchung und Gewinnung'' bestimmt. Die Vortraege beschaeftigten sich mit den Gebieten Exploration and Production allgemein, Geologie, Lagerstaettentechnik, Foerdertechnik fuer Erdoel/Erdgas, Bohrtechnik, Untertagesspeichertechnik, Geophysik und Geochemie.

  16. Op het raakvlak van historische disciplines

    Directory of Open Access Journals (Sweden)

    Dick E.H. de Boer

    2015-12-01

    Full Text Available At the Meeting Point of Historical DisciplinesThis contribution introduces the way in which the interaction between history and archaeology is examined, taking the case of the identification of a tomb and remains of Count William II of Holland, King of the Holy Roman Empire (†1256, in the former abbey church of Middelburg. It stresses the necessity of strict source criticism, which should be self-evident, but is at risk of receiving less attention. This is even truer when one of the disciplines is used as an auxiliary argument to support the other instead of a balanced approach. Wishful interpretation in such a case is a clear risk. The contribution gives some examples, before sketching the advance made thanks to the reapprochement of history and archaeology, and the consequent need for a registration system of archaeological data that can facilitate multi-disciplinary analysis. It ends with an introduction to the different stands in the dossier.Deze bijdrage biedt een inleiding op de wijze waarop de interactie tussen geschiedenis en archeologie wordt bekeken aan de hand van een casus betreffende het graf en de overblijfselen van de in 1256 gesneuvelde graaf Willem II van Holland, koning van het Heilige Roomse Rijk, in de voormalige abdijkerk van Middelburg. Hij benadrukt de noodzaak van een nauwgezette bronnenkritiek. Hoewel deze als vanzelfsprekend moet worden beschouwd, is er een zeker risico van verminderde zorgvuldigheid. Dit speelt vooral wanneer één van de disciplines wordt gebruikt als een hulp-argument, dat de uitkomsten van de andere moet ondersteunen, in plaats van een benadering waarbij beide disciplines in evenwicht zijn. Bij een onbalans is het risico van interpreteren in het licht van de gewenste uitkomst duidelijk aanwezig. De bijdrage geeft hiervan enkele voorbeelden, alvorens de vooruitgang te schetsen die is geboekt juist dankzij de toenadering tussen geschiedenis en archeologie, en aan te geven dat er behoefte is aan een

  17. Carbo-cyclohexadienes vs. carbo-benzenes: structure and conjugative properties† †The investigations presented in this report have been performed within the framework of the French-Ukrainian GDRI “Groupement Franco-Ukrainien en Chimie Moléculaire” funded by the CNRS. ‡ ‡Electronic supplementary information (ESI) available: Experimental details, spectroscopic and crystallographic data. CCDC 1003439, 951896 and 951897. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc02742f Click here for additional data file. Click here for additional data file.

    Science.gov (United States)

    Rives, Arnaud; Baglai, Iaroslav; Barthes, Cécile; Saffon-Merceron, Nathalie; Saquet, Alix; Voitenko, Zoia; Volovenko, Yulian

    2015-01-01

    Ideally C s-/C 2v-symmetric chromophores, constituted by two electro-active groups conjugated through the carbo-mer of the cyclohexa-1,3-diene core, are selectively prepared by the SnCl2-mediated reduction of tailored hexaoxy-[6]pericyclynes: in the latter substrates, one of the 1,4-dioxybut-2-yne edges is “chemically locked” by two CF3 substituents preventing complete reduction to the corresponding aromatic carbo-benzenic core, which is expected to be more “π-insulating” between the electro-active ends. The bis-trifluoromethylated carbo-cyclohexadiene products are also shown to be significantly stabilized with respect to their bis-phenylated analogues. Their structural (crystal X-ray diffraction analyses), spectroscopical (NMR and UV-vis spectra), physio-optical (dichromism in solution) and electrochemical (cyclic voltammograms) properties are compared on the basis of the electron-donating/electron-withdrawing nature of the substituents. These properties are also compared with those of their aromatic carbo-benzene and flexible carbo-n-butadiene counterparts. PMID:29560201

  18. Evaluation de l'impact des activités anthropiques sur les organismes aquatiques dulçaquicoles. Méthodes et modèles pour la mesure de l'impact des rejets chimiques

    OpenAIRE

    Garric, J.

    2008-01-01

    / Avant toute chose, je crois nécessaire de replacer le contexte de mes activités de chercheur à la fois au sein de l'organisme où j'ai réalisé ma carrière, mais également dans le cadre du domaine où j'ai travaillé, l'écotoxicologie. Après une formation en Sciences et Techniques de l'Eau à la faculté des Science de Montpellier (USTL) dans laquelle étaient étroitement associées des formations en chimie et en biologie, j'ai obtenu en 1980 un doctorat en Ecotoxicologie et Chimie de l'Environneme...

  19. Berthollet

    OpenAIRE

    Grison, Emmanuel

    2010-01-01

    Portrait de Berthollet Un des deux premiers professeurs de chimie, Sénateur en 1800, il continue son cours gratuitement La mémoire de l’Ecole était décidément bien ingrate, au temps de notre peintre Colin, envers ce pauvre Guyton : le cartouche qu’on plaça sous le portrait de Berthollet ne reconnaît que deux professeurs de chimie, Fourcroy et lui. Nous avons rendu justice au troisième instituteur, tombé dans l’oubli, mais nous verrons que Berthollet a, de fait, laissé dans l’histoire de la c...

  20. A new method for dosing rhodamine B in natural water; Dosage de la rhodamine B dans les eaux naturelles

    Energy Technology Data Exchange (ETDEWEB)

    Marichal, M.; Benoit, R. [Commissariat a l' energie atomique et aux energies alternatives - CEA, Centre de Marcoule, Centre de Production de Plutonium de Marcoule, Service de Protection contre les Radiations (France)

    1961-07-01

    A simple and sensitive method well adapted to hydrological research. The dye is first extracted from the water sample by isoamyl alcohol and then the fluorescence of the alcoholic solution, after excitation by ultraviolet radiation, is measured spectrophotometrically. The sensitivity of the method is about 10{sup -12}, that is, a millionth of a milligram of dye per litre. Reprint of a paper published in 'Chimie Analytique', N. 2, Feb 1962, p. 70-72 [French] Methode simple et sensible convenant bien aux recherches hydrologiques. Le colorant est prealablement extrait de l'echantillon d'eau par l'alcool isoamylique; la fluorescence de la solution alcoolique eclairee en lumiere ultraviolette est ensuite mesuree au spectrophotometre. La sensibilite de la methode est de l'ordre de I0{sup -12}, soit un millionieme de milligramme de colorant par litre. Reproduction d'un article publie dans 'Chimie Analytique', N. 2, Feb 1962, p. 70-72.

  1. Synthèses des propargylamines sur des catalyseurs Au-Co / TiO2

    OpenAIRE

    FEKIR, Amina

    2015-01-01

    La réaction de couplage C-C est une réaction fondamentale de la chimie organique. C’est une transformation qui permet l'association de deux radicaux hydrocarbures. Cette réaction, réalisée à partir d’un dérivé de bore et d’un dérivé électrophile, en présence d’un catalyseur organométallique et d’une base[1]. Actuellement, un des défis de la chimie fondamentale et industrielle est de synthétiser rapidement des collections de molécules (appelées également chimiothèques) pour pouv...

  2. Photochemical conversion and storage of solar energy. In New Journal of Chemistry, February 1987, Volume 11, Number 2

    Energy Technology Data Exchange (ETDEWEB)

    1987-01-01

    This volume is actually a special issue of Nouveau Journal de Chimie, which contains the proceedings of a conference held in Paris in 1986. There are 23 papers in it, all in English. As is to be expected, many of them are concerned with solid-state effects, semiconductors, and membranes. Six of the papers are called Round Table Reports and include such topics as photocatalysis, biomimetric systems, etc. The format is that of a journal, and there is no index.

  3. 2399-IJBCS-Article-Kpan K Kouakou Gains

    African Journals Online (AJOL)

    hp

    Le glyphosate, premier herbicide utilisé au monde est une molécule difficile à quantifier par la chromatographie en phase liquide à haute performance (HPLC), eu égard à l'absence de chromophore dans sa structure. La chimie analytique est donc à la recherche perpétuelle de méthodes de détermination du glyphosate.

  4. Dosage du glyphosate par HPLC après extraction et dérivation à l'O ...

    African Journals Online (AJOL)

    Le glyphosate, premier herbicide utilisé au monde est une molécule difficile à quantifier par la chromatographie en phase liquide à haute performance (HPLC), eu égard à l'absence de chromophore dans sa structure. La chimie analytique est donc à la recherche perpétuelle de méthodes de détermination du glyphosate ...

  5. Recent Advances in Supramolecular Assemblies with Nucleic Acids

    Science.gov (United States)

    2007-08-29

    xavier.moreau@up.univ-mrs.fr 28 Name Contact Information Laurence Navailles Centre de Recherche Paul Pascal, 115, Avenue Albert Schweitzer 33600...Switzerland Email : peter.walde@mat.ethz.ch 29 Name Contact Information Cécile Zakri Centre de Recherche Paul Pascal, 115, Avenue Albert ... Schweitzer 33600 Pessac, France Email : zakri@crpp-bordeaux.cnrs.fr Guy Zuber Laboratoire de Chimie Génétique, CNRS UMR 7175- LC1- Faculté de

  6. Les effets des antibiotiques administrés en bas âge sur la fonction ...

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

    ... jouent un rôle important dans le développement et la fonction normale de nos systèmes immunitaire et nerveux. Ce projet permettra d'obtenir d'importantes indications sur la façon dont les antibiotiques peuvent perturber la flore intestinale et affecter la fonction cérébrale chez les jeunes enfants. La chimie du cerveau et ...

  7. 109 Composition chimique et propriétés antibactériennes des huiles ...

    African Journals Online (AJOL)

    NGOM

    2Laboratoire des Produits Naturels (LPN), Département de chimie, Faculté des sciences et techniques, .... analytique, la technique a été améliorée par la mise en ligne deux colonnes capillaires de polarité différente ... couplage CPG/SM a été réalisé sur colonne capillaire en silice fondue (25 m x 0,23 x 0,25 µm) avec de.

  8. Évaluation de la productivité du maïs ( Zea mays L.) sous ...

    African Journals Online (AJOL)

    Conclusion et principales applications de la recherche: L'application des biomasses T. diversifolia et E. abyssinica en combinaison organo-minérale sur une culture de maïs démontre jouer un rôle multiple sur la physique, la chimie et la biologie du sol avec comme conséquence une augmentation du rendement de l'ordre ...

  9. Fulltext PDF

    Indian Academy of Sciences (India)

    MUSTAPHA BENCHARIFa,∗. aLaboratoire de Chimie des Matйriaux Constantine, Universitй Constantine 1, 25000 Constantine, Algйrie. bFacultй de Technologie, Universitй 20 Aoыt 1955, 21000 Skikda, Algйrie e-mail: m_bencharif@umc.edu.dz. MS received 19 April 2015; revised 8 July 2015; accepted 13 July 2015.

  10. A new method for dosing rhodamine B in natural water

    International Nuclear Information System (INIS)

    Marichal, M.; Benoit, R.

    1961-01-01

    A simple and sensitive method well adapted to hydrological research. The dye is first extracted from the water sample by isoamyl alcohol and then the fluorescence of the alcoholic solution, after excitation by ultraviolet radiation, is measured spectrophotometrically. The sensitivity of the method is about 10 -12 , that is, a millionth of a milligram of dye per litre. Reprint of a paper published in 'Chimie Analytique', N. 2, Feb 1962, p. 70-72 [fr

  11. Eye-Safe Polycrystalline Lasers

    Science.gov (United States)

    2013-03-01

    Goldsmith , Spectrochim. Acta, 20 [5] 781-4 (1964). 15 A. B. Ali, M. O. Awaleh, M. Leblanc, L. S. Smiri, V. Maisonneuve, and S. Houlbert, C.R.Chimie...Chantikul, B. R. Lawn, andD. B. Marshall , J. Am. Ceram. Soc., 64[9] 533- 538 (1981). 21. L. M. Seaverson, S. Q. Luo, P. L. Chien, andJ. F. Mcclelland, J

  12. 1758-IJBCS-Article-Hoekou Yao

    African Journals Online (AJOL)

    hp

    albicans, une levure isolée du prélèvement vaginal chez une malade atteinte de candidose au Laboratoire de Microbiologie du Centre. Hospitalier Universitaire Sylvanus Olympio. (Togo). Extraction. L'extraction a été réalisée dans le. Laboratoire de chimie de l'Ecole Supérieure des Techniques Biologiques et Alimentaires.

  13. 1398-IJBCS-Article-Joseph Kouassi+

    African Journals Online (AJOL)

    hp

    3Université d'Abobo-Adjamé, Laboratoire de Chimie Bio-Organique et de Substances Naturelles,. 02 BP 801 Abidjan 02, Côte d'Ivoire. 4INRA Science du Sol, BP 20619, 45166 Olivet cedex, ...... Mobilité relative des métaux lourds issus de la décharge d'Akouédo et risque de contamination de la nappe du Continental.

  14. Lac dayet Aoua (Maroc)

    African Journals Online (AJOL)

    Saad

    F.S.T. Fès - Sais, Université Sidi Mohammed Abdallah Fès, B.P. 2202, Maroc. 2Laboratoire des ... d'étude en complément de la composition phytoplanctonique et des analyses de la physico-chimie des eaux à l'entrée, au ... L'analyse des paramètres physico-chimiques, au point central du lac, a montré que l'eau du lac.

  15. Untitled

    African Journals Online (AJOL)

    2- Département de Chimie Physique, Académie du Pétrole et du Gaz, -20, av. Lenine, 370601 Bakou, Azerbaïdjan. RÉSUMÉ ... tion d'eau et séchage à 125 °C, le premier produit obtenu est calciné suivant deux méthodes ... infrarouge du catalyseur, la frange d'absorption 860 cm* conditionnée par la vibration des liaisons ...

  16. International Symposium on Organosilicon Chemistry (8th) Held in St. Louis Missouri on 7-12 June 1987.

    Science.gov (United States)

    1988-05-13

    Set Pro- Singlet Potential Energy Surface of cess? Si2 + H G. Cerveau , C. Chuit, R. J. P. Shiro Koseki and Mark S. Gordon Corriu, L. Gerbier and C...Robert West lyl Silicon Bond Genevieve Cerveau , Claude Chuit, Robert J. P. Corriu and Inoranic Chemistry of Silicon Catherine Rey6 Silicon-Transition...Genevieve Cerveau Institut de Chimie Fine Universite des Sciences Julian Chojnowski et Techniques du Languedoc Center of Molecular and Macro- F-34060

  17. French chemists and the international reorganisation of chemistry after World War I.

    Science.gov (United States)

    Fauque, Danielle M E

    2011-07-01

    Founded in 1919, the International Union of Pure and Applied Chemistry (IUPAC) was successor to the International Association of Chemical Societies (IACS), which had been founded eight years earlier at the initiative of Albin Haller. The statutes of the IUPAC (like those of the IACS) were written in French, and it was agreed that the IUPAC's administrative headquarters should be in Paris. With these arrangements in place, the role of French chemists generally, and of Haller and Charles Moureu in particular, assumed crucial importance. In 1927, on the occasion of the centenary of Marcelin Berthelot's birth, plans were laid for an international centre for chemistry in Paris, soon to be known as the Maison de la Chimie. From the start, the Maison de la Chimie project was led by the French, most conspicuously by Jean Gérard, general secretary of the Société de chimie industrielle and of the IUPAC. Gérard's contribution to a number of national and international committees, notably for scientific documentation, left an enduring legacy. The years between 1918 and 1927, especially 1918-1919, were decisive for the rebuilding, on many fronts, of international networks embracing individuals and institutions recently separated by war. This article examines the particular case of chemistry, with reference to this wider context and to the widely shared determination to fashion an organisation that would transcend national boundaries and embrace both the pure and the applied aspects of the discipline.

  18. Canto y plaquitas grabadas del norte de Cáceres (Extremadura, España

    Directory of Open Access Journals (Sweden)

    Soledad CORCHÓN RODRÍGUEZ

    2009-12-01

    Full Text Available RESUMEN: Se presentan cinco documentos mobiliares de gran interés arqueológico, recogidos en superficie en el Valle de Ambroz (Norte de Cáceres. Aunque los trabajos de prospección, en curso, probablemente permitirán precisar su contexto arqueológico inmediato, el estudio preliminar de sus relaciones y paralelismos con otros objetos mobiliares sugiere varias hipótesis interpretativas. Se analiza su vinculación con las tradiciones artísticas del Megalitismo, y también la hipótesis de su relación con contextos de Neolítico pre-megalítico, en el marco de tardías pervivencias de tradiciones enraizadas en el Paleolítico final-Mesolítico.ABSTRACT: Five portable documents of great archeologial interest found on the surface in the Valley of Ambroz (northern Caceres, Spain are presented. Although prospection work now being carried out will probably allow us to know their immediate archeological context more precisely, a preliminary study of their relationships and parallelisms with other portable objects suggests several hypotheses for interpretation. Their link with the artistic traditions of Megalithism is analysed, as well as the hypothesis of their relationship to pre-Megalithic Neolithic settings, within the framework of late remains of traditions rooted in the final Paleolithic-Mesolithic

  19. Zur Geschichte der Geowissenschaften im Museum für Naturkunde zu Berlin. Teil 6: Geschichte des Geologisch-Paläontologischen Instituts und Museums der Universität Berlin 1910–2004

    Directory of Open Access Journals (Sweden)

    W. Gross

    2004-01-01

    Full Text Available Die Entwicklung des Geologisch-Paläontologischen Instituts und Museums der Universität Berlin von einer Institution, die Geologie zusammen mit Paläontologie als eine Einheit vertrat, über eine Institution, die eine geotektonische Ausrichtung hatte, zu einer auf Paläontologie konzentrierten Institution wird nachvollzogen. Die beiden Institutsdirektoren am Anfang des 20sten Jahrhunderts waren Vertreter der allumfassenden Geologie des 19ten Jahrhunderts, während die beiden folgenden Direktoren eine Geologie ohne Paläontologie vertraten. Das führte zu einer Trennung der beiden Richtungen, und nach der III. Hochschulreform der DDR 1968 verblieb allein die sammlungsbezogene Paläontologie am Museum. Nach der Wiedervereinigung wurde ein Institut für Paläontologie mit biologischer Ausrichtung mit zwei Professuren, einer für Paläozoologie und einer für Paläobotanik, eingerichtet. The development of the Geologisch-Paläontologisches Institut und Museum of the Museum für Naturkunde at the Humboldt University (formerly Friedrich-Wilhelm-Universität in Berlin from a geology-paleontology institution to a pure paleontology institution is described. The first two directors of the department in the beginning of the 20th century, Prof, von Branca and Prof. Pompeckj, represented a 19th century concept of a geology, which included paleontology, even vertebrate paleontology as the crown jewel of geology. They fought sometimes vigorously against a separation of paleontology from geology. The next two directors. Prof. Stille and Prof, von Bubnoff, were the leading geologists in Germany; to be a student of Stille was a special trade mark in geology of Germany. They represented a geology centered on tectonics. The separation of paleontology as separate section was prepared. The destructions of the Second World War, the following restaurations and the division of Germany into two States influenced strongly their directorships. The education of geologists

  20. Assessment of the potential of the Mainfranken region, northern Bavaria, for underground storage of geothermal energy; Erkundung des regionalen Potentials fuer die Untergrundspeicherung thermischer Energie in Mainfranken (UTEM)

    Energy Technology Data Exchange (ETDEWEB)

    Barthel, R; Heinrichs, G; Udluft, P [Lehr- und Forschungsbereich Hydrogeologie und Umwelt, Inst. fuer Geologie, Univ. Wuerzburg (Germany); Ebert, H P; Fricke, J [Abt. Waermedaemmung/Waermetransport, Bayerisches Zentrum fuer Angewandte Energieforschung e.V., Wuerzburg (Germany)

    1997-12-01

    The following paper presents a research project that is planned as a cooperation of the Geological Institute, University of Wuerzburg and the Bavarian Center of Applied Energy Research. In this project the potentials for underground thermal energy storage will be investigated in the region of Mainfranken, Northern Bavaria (Main = the river `Main`, Franken = Franconia). All aspects of underground storage will be studied with respect to the specific geographical and geological situation of the area. The study will provide a detailed map of possible storage sites, from which several case studies and at least one demonstration projects will result. (orig.) [Deutsch] Im vorliegenden Beitrag wird ein Forschungsprojekt vorgestellt, das gemeinsam vom Institut fuer Geologie der Universitaet Wuerzburg und dem Zentrum fuer Angewandte Energieforschung in Bayern geplant wird. Ziel des Projekts ist die Erkundung des Potentials fuer die Untergrundspeicherung thermischer Energie in Mainfranken (Nordbayern). Alle Aspekte der Untergrundspeicherung werden regionalspezifisch betrachtet. Neben der Erstellung differenzierter Karten geeigneter Standorte sind Fallstudien und Demonstrationsprojekte in Planung. (orig.)

  1. CPA ups storage at Lavera site

    International Nuclear Information System (INIS)

    Back, R.

    1992-01-01

    Compagnie Parisienne des Asphaltes (CPA; Paris) and its subsidiary Pacsud -owned 65% by CPA and 35% by Shell Chimie (Paris) - have inaugurated their new chemicals storage site at Lavera, France, in the Europort South complex near Marseilles. The facilities, with 60,000-m.t./year capacity, also include a barreling plant that will have output of up to 250 bbl/hour when it comes onstream next spring. Total investment for these facilities amount to F122 million ($22.5 million), including F22 million for the barreling unit. CPA, France's number two storage specialist, after LB Chimie (Paris), is jointly owned by investment company Union Normandie (60%), Elf Aquitaine (Paris; 20%), and Total (Paris; 20%). Adding to its existing French storage sites at Dunkirk and Rouen, CPA says it decided to build on the Pacsud venture because it considered it attractive to invest in the petroleum and petrochemical complex of Fos-Berre-Lavera, particularly since the present trend in the oil and chemical industries is to subcontract all ancillary functions, especially logistics. CPA general manager Rafic Charles Rathle says that customer requirements and the role of the service provider are changing. With that in mid, CPA, in addition to providing storage terminals, converts its depots into distribution and packing centers. At Lavera the company has taken over storage, blending, and barreling operations for Pacsud and its direct customers. For example, Pacsud has a long-term contract with Shell Chimie for the latter's additive production at a 10,000-m.t./year rate. Another long-term contract is being negotiated, but the identity of the customer was not revealed

  2. Bibliografía

    Directory of Open Access Journals (Sweden)

    Martí Mas Cornellá

    1992-01-01

    Full Text Available RESEÑA 1 de : Thoen, Hugo; Burgeois, Jean; Vermeulen, Frank; Crombé, Philippe; Verlaeckt, Koen. Studia Archaeologica, Líber amicorum Jacques A. E. Nenquin. Gante : Universiteit Gent, Seminaria voor Archeologie, 1991. RESEÑA 2 de : Hodder, Ian; Orton, Clive. Análisis Espacial en Arqueología. Barcelona : Editorial Critica, 1990. RESEÑA 3 de : Barriere, Claude. L'Art parietal du Ker de Massat. Toulouse : Presses Universitaires du Mirail, 1990. RESEÑA 4 de : Ramos Muñoz, José; Espejo Herrerías, Mª del Mar y otros. Cueva de Árdales. Su recuperación y estudio. Árdales : Ayuntamiento de la Villa de Árdales, 1992. RESEÑA 5 de : Guilaine, Jean; Gutherz, Xavier. Autour de Jean Arnal. Montpellier : Université des Sciences et Techniques du Languedoc, 1990. RESEÑA 6 de : González Echegaray, Joaquín. El Creciente fértil y la Biblia. Estella (Navarra : Ed. Verbo Divino, 1991. RESEÑA 7 de : de Góngora y Iviartínez, Manuel. Antigüedades prehistóricas de Andalucía. Estudio preliminar por iVIauricio Pastor Muñoz y Juan Antonio Pachón Romero. Granada : Universidad de Granada, 1991. RESEÑA 8 de : Bonnet, Charles. Kerma royaume de Nubie. Ginebra : Mission archéologique de l'Université de Genéve au Soudan, 1990.

  3. Welcome to Crystals: A New Open-Access, Multidisciplinary Forum for Growth, Structures and Properties of Crystals

    Directory of Open Access Journals (Sweden)

    Gerd Meyer

    2010-12-01

    Full Text Available The majority of the earth’s crust is made up of crystalline material. The research areas of mineralogy, petrology, chimie minerále (inorganic chemistry and, of course, crystallography outgrew from the fascination of mankind with the color and symmetry of crystals. Crystals have translational symmetry in two or three dimensions, quasicrystals have translational symmetry in higher spaces. Further symmetries may be observed by the eye, by microscopic techniques or by the diffraction of X-ray, electron, or neutron beams. Diffraction techniques are also used, due to Max von Laue’s eminent discovery a century ago, to determine crystal structures. [...

  4. Fractal-like kinetics, a possible link between preconditioning and sepsis immunodepression. On the chemical basis of innate immunity.

    Science.gov (United States)

    Vasilescu, C; Olteanu, M; Flondor, P

    2012-01-01

    In a recent paper the authors hypothesized that the so called fractal-like enzyme kinetics of intracellular reactions may explain the preconditioning effect in biology (Vasilescu C, Olteanu M, Flondor P, Revue Roumaine de Chimie. 2011; 56(7): 751-7). Inside cells the reaction kinetics is very well described by fractal-like kinetics. In the present work some clinical implications of this model are analyzed. Endotoxin tolerance is a particular case of preconditioning and shows similarities with the immunodepression seen in some sepsis patients. This idea offers a theoretical support for modulation of the enzymatic activity of the cell by changing the fractal dimension of the cytoskeleton.

  5. Nanocrystalline hydroxyapatite ceramics prepared by hydrolysis in polyol medium

    Science.gov (United States)

    Mechay, Abderrahmen; Feki, Hafed E. L.; Schoenstein, Fréderic; Jouini, Noureddine

    2012-07-01

    This Letter describes a new approach for the synthesis of hydroxyapatite nanoparticles, which involves precipitation and hydrolysis reactions conducted in polyol medium. In fact, ammonium-hydrogen phosphate and calcium nitrate were dissolved in polyol, and then heated at the boiling point of the polyol (ethane1, 2diol or propane1, 2diol). Besides, the phase and composition of the polycrystalline were studied by TGA/DTA, FT-IR, TEM and XRD techniques. The nanoparticles thus obtained present interesting morphological characters varying from needle to very thin platelet. Moreover, the hydroxyapatite prepared in ployol shows higher cristallinity in comparison with that obtained by other 'chimie douce' methods.

  6. [The "conclusions of Pharmacy" in Nancy, at the end of the 18th century: between "synthèses" and "thèses"].

    Science.gov (United States)

    Julien, P; Martin, J

    1995-01-01

    A special requirement of the law for apothecaries in Nancy in 1764 imposed on the candidates for a master's degree was the written response to four questions following their practical examinations. Two documents heretofore unpublished show the results of this obligation: the Conclusions de Pharmacie by Joseph Pierson (1765) and the Conclusions de Pharmacie et de Chimie by François Mandel (1771). The authors of the present article comment on these documents and make an attempt to place them in the confused history of "synthèses" and "thèses".

  7. The 52nd International Conference on Medicinal Chemistry (RICT 2016) of the French Medicinal Chemistry Society (SCT) Held in Caen (Normandy).

    Science.gov (United States)

    Sapi, Janos; Van Hijfte, Luc; Dallemagne, Patrick

    2017-06-21

    Outstanding Medchem in France: Guest editors Janos Sapi, Luc Van Hjfte, and Patrick Dallemagne look back at the 52 nd International Conference on Medicinal Chemistry (RICT 2016) held in Caen, France. They discuss the history of the French Medicinal Chemistry Society (Société de Chimie Thérapeutique, SCT) and provide highlights of last year's events, including some key presentations now collected in this Special Issue. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Elimination du cadmium de l'acide phosphorique par électrodialyse

    African Journals Online (AJOL)

    Département de chimie, université Badji Mokhtar Annaba. Revisé le 14/12/2011. Accepté le 09/01/2012. صﺧﻟﻣ. تﺳﻣﻟا روطﺗﻟا لﺟأ نﻣ مھﻷا ﻲﺳﺎﯾﺳﻟاو يدﺎﺻﺗﻗﻻا نﺎھرﻟا تﺣﺑﺻأ دﻘﻟ ...

  9. "Does understanding the brain need proteomics and does understanding proteomics need brains?"--Second HUPO HBPP Workshop hosted in Paris.

    Science.gov (United States)

    Hamacher, Michael; Klose, Joachim; Rossier, Jean; Marcus, Katrin; Meyer, Helmut E

    2004-07-01

    The second Human Brain Proteome Project (HBPP) Workshop of the Human Proteome Organisation (HUPO) took place at the Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI) from April 23-24, 2004. During two days, more than 70 attendees from Europe, Asia and the US came together to decide basic strategic approaches, standards and the beginning of a pilot phase prior to further studies of the human brain proteome. The international consortium presented the technological and scientific portfolio and scheduled the time table for the next year.

  10. ETUDE EXPLORATOIRE DES ACIDES GRAS POLYINSATURÉS DES AIGUILLES DE PIN

    OpenAIRE

    KADARI, Abdelhamid

    2012-01-01

    Depuis les temps les plus anciens, l’utilisation des plantes dans le domaine de la santé est toujours d’actualité (1), dans la mesure où elle représente une alternative sérieuse ou tout au moins un complément appréciable à la pharmacie classique issue de la chimie moderne. En effet, plus de 25 % des médicaments prescrits dans le monde entier dérivent directement ou indirectement des plantes (2). Cependant, en tant que sources de médicaments, les plantes restent encore sous plusieurs études, s...

  11. Les Affinités électives de Goethe : entre science et littérature

    Directory of Open Access Journals (Sweden)

    Bernard Joly

    2011-03-01

    Full Text Available Par leur titre même, Les affinités électives de Goethe renvoient à la doctrine chimique des rapports entre différents corps qui, à partir des travaux d’Etienne-François Geoffroy en 1718, s’impose comme théorie dominante dans la chimie du XVIIIe siècle. Goethe ne se contente pas d’une simple analogie entre les attirances amoureuses qui font et défont les couples et les opérations chimiques qui règlent les liaisons et les précipitations des substances chimiques. Son excellente connaissance de la tradition chimique et alchimique le conduit à considérer l’affinité comme une loi de la nature produisant aussi bien ses effets en chimie que chez les êtres vivants et dans le psychisme.The title of Goethe’s novel Elective Affinities refer to the chemical tenet of rapports between different bodies which, from Etienne-François Geoffroy’s works in 1718, emerge as a prevailing theory in the eighteenth-century chemistry. Goethe does not limit his views to the analogy between love attractions which made and break up couples and chimical processes which determine bonds and precipitations of chemical substances. His excellent knowledge of chemical and alchemical tradition leads him to consider affinity as a law of nature having effects in chemistry as well as in living being and into mind.

  12. Marie Curie, les femmes et la science, d'hier à aujourd'hui - English

    CERN Multimedia

    CERN. Geneva

    2017-01-01

    Marie Curie, les femmes et la science, d'hier à aujourd'hui Conférence par Hélène Langevin-Joliot Avec la participation de l'Echo du Reculet de Thoiry. L'enregistrement et la liste d'attente sont déjà complets... Mais il n'est pas rare que des personnes réservent et ne viennent pas. Nous réassignerons les places libérées selon la règle "premier arrivé, premier inscrit". Nous envisageons la possibilité de faire un webcast de la conférence. Plus d'information bientôt. Hélène Langevin-Joliot, directrice de recherche émérite en physique nucléaire fondamentale au CNRS à Orsay, est aussi la fille de Frédéric et Irène Joliot-Curie (prix Nobel de chimie en 1935) et la petite-fille de Pierre Curie (prix Nobel de physique en 1903) et de Marie Curie (prix Nobel de physique en 1903 et prix Nobel de chimie en 1911). Hélène Langevin-Joliot nous parlera de sa vie scientifique, de l’histoire extraordinaire de sa famille et en particulier du rôle des ...

  13. Marie Curie, les femmes et la science, d'hier à aujourd'hui

    CERN Multimedia

    CERN. Geneva; Mariotti, Chiara; Vicinanza, Domenico

    2017-01-01

    Marie Curie, les femmes et la science, d'hier à aujourd'hui Conférence par Hélène Langevin-Joliot Avec la participation de l'Echo du Reculet de Thoiry. L'enregistrement et la liste d'attente sont déjà complets... Mais il n'est pas rare que des personnes réservent et ne viennent pas. Nous réassignerons les places libérées selon la règle "premier arrivé, premier inscrit". Au vu de la forte demande, la conférence sera également disponible en vidéoconférence : lien d'accès "webcast" disponible en bas de cette page. Hélène Langevin-Joliot, directrice de recherche émérite en physique nucléaire fondamentale au CNRS à Orsay, est aussi la fille de Frédéric et Irène Joliot-Curie (prix Nobel de chimie en 1935) et la petite-fille de Pierre Curie (prix Nobel de physique en 1903) et de Marie Curie (prix Nobel de physique en 1903 et prix Nobel de chimie en 1911). Hélène Langevin-Joliot nous parlera de sa vie scientifique, de l’histoire extraordinai...

  14. Synthesis and characterization of sodium vanadium oxide gels: the effects of water (n) and sodium (x) content on the electrochemistry of Na(x)V2O5·nH2O.

    Science.gov (United States)

    Lee, Chia-Ying; Marschilok, Amy C; Subramanian, Aditya; Takeuchi, Kenneth J; Takeuchi, Esther S

    2011-10-28

    Sodium vanadium oxide gels, Na(x)V(2)O(5)·nH(2)O, of varying sodium content (0.12 n > 0.01) and interlayer spacing were found to be inversely proportional to the sodium level (x), thus control of sodium (x) content provided a direct, chimie douce approach for control of hydration level (n) and interlayer spacing, without the need for high temperature treatment to affect dehydration. Notably, the use of high temperatures to modify hydration levels can result in crystallization and collapse of the interlayer structure, highlighting the distinct advantage of our novel chimie douce synthesis strategy. Subsequent to synthesis and characterization, results from an electrochemical study of a series of Na(x)V(2)O(5)·nH(2)O samples highlight the significant impact of interlayer water on delivered capacity of the layered materials. Specifically, the sodium vanadium oxide gels with higher sodium content and lower water content provided higher capacities in lithium based cells, where capacity delivered to 2.0 V under C/20 discharge ranged from 170 mAh/g for Na(0.12)V(2)O(5)·0.23H(2)O to 300 mAh/g for Na(0.32)V(2)O(5)·0.01H(2)O. The capacity differences were maintained as the cells were cycled. This journal is © the Owner Societies 2011

  15. Chemistry of actinides and fission products in the nuclear-fuel cycle

    International Nuclear Information System (INIS)

    Anon.

    2004-01-01

    This colloquium was held under the auspices of the French and Russian Academies of Sciences, from 21 to 23 May 2003, at the 'Ecole nationale superieure de chimie de Paris' (ENSCP), under the cooperative framework agreed between the two Academies. Fifteen specialists from each country were brought together to present their results concerning research in their respective fields (industrial considerations, fundamental chemistry, the environment, new conditioning systems, hydro- and pyro-chemical separation techniques), situating the results in the general context of the two countries'common strategy for closing the nuclear fuel cycle and for the management of radioactive waste. The colloquium brought together 26 oral presentations, and three round table discussions (theoretical chemistry and modelling, the frontiers of research on the nuclear cycle, elemental characterisation). The speakers chosen represented a large section of the organisations involved in the research on these topics, from each country. This thematic issue of the Comptes Rendus Chimie presents some new insights into these topics and some original results. The colloquium was supported financially par the DRI of the French Academy des sciences, CNRS, IN2P3, CEA, Cogema, EDF, and ENSCP. (authors)

  16. Relationships in the Flipped Classroom

    Directory of Open Access Journals (Sweden)

    Brett M. McCollum

    2017-12-01

    Full Text Available This study examines the effectiveness of flipped classrooms in chemistry, and identifies relationships as a major factor impacting the success of flipped instruction methods. Examination of student interview data reveals factors that affect the development of peer-peer, peer-peer leader, and peer-expert relationships in first-year general chemistry and second-year organic chemistry flipped classrooms. Success was measured in terms of student perceptions of the effectiveness of the instruction, as well as student academic development. Furthermore, analysis of research participant interviews reveals that academic reading circles, open-response multiple-attempt group quizzes, and peer leaders are important elements of a text-centric flipped approach at a small-classroom, commuter-campus university. Student reflections and classroom observations provide further support for these conclusions. Cet étude examine l’efficacité des salles de classe inversées en chimie et identifie la création de liens en tant que facteur important qui affecte la réussite des méthodes d’instruction inversée. L’examen des données provenant d’entrevues avec les étudiants révèle les facteurs qui affectent le développement des rapports d’étudiant à étudiant, d’étudiant à leader et d’étudiant à expert dans un cours inversé de chimie générale de première année et dans un cours de chimie organique de deuxième année. La réussite a été mesurée en termes de perceptions des étudiants de l’efficacité de l’instruction, ainsi que du développement académique des étudiants. De plus, l’analyse des entrevues des participants à la recherche révèle que les cercles de lecture universitaires, les tests de groupes à essais multiples et à réponses ouvertes, ainsi que les leaders de groupes sont des éléments importants d’une approche inversée centrée sur un texte en petite salle de classe, dans une université de banlieusards. Les

  17. Academic Training: Climate change and challenges for the environment

    CERN Multimedia

    Françoise Benz

    2005-01-01

    2005-2006 ACADEMIC TRAINING PROGRAMME LECTURE SERIES 14, 15, 16 November from 11:00 to 12:00 - TH Auditorium, bldg. 4 Climate change and challenges for the environment by C. Schlüchter / Institut für Geologie, Univ. Bern, CH Climate change as seen by a geologist Glaciers are an integrated part of the high altitudes and the high latitudes of our planet. They are sensitive to temperature and moisture changes and adjust their mass balances accordingly. By doing so they interact with their substratum, the geological basement and they produce characteristic imprints of their presence, their variability and their disappearance. In glacial geology and paleoglaciology such imprints of former glaciers are carefully recorded, mapped and, hopefully, dated in order to obtain amplitude and periodicity records of their changes - as forced by changing climate, as we believe. In the upcoming lectures three aspects will be discussed: the last glaciation in the Swiss Alps. A reconstruction is shown based on fieldwor...

  18. Application of paper chromatography to the determination of some elements in minerals and rocks; Application de la chromatographie sur papier a la determination de certains elements dans les mineraux et les roches

    Energy Technology Data Exchange (ETDEWEB)

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

    1964-11-01

    This publication describes our work in applying paper chromatography to the fields of mineralogy and geology. We have studied the separation and determination of the following elements: Nb, Ta, Ti, Co, Cu, Mn, Sn, Ge, As, Sb, Bi, U, Th, Be, Au, Pb, Zn, V and Mo. The development of separation methods for these various elements has led us to solve many interference problems. These methods make it possible to separate and measure mineral components. They also enable us to search for trace elements in ores, rocks soils and carbonaceous materials. Finally let us point out that this technique may equally be used for analysis in very radioactive environment. (author) [French] Dans cette etude, nous etendons le champ d'application de la chromatographie sur papier aux domaines de la mineralogie et de la geologie. Nous avons etudie la separation et la determination des elements suivants: Nb, Ta, Ti, Co, Cu, Mn, Sn, Ge, As, Sb, Bi, U, Th, Be, Au, Pb, Zn, V et Mo. La mise au point des methodes de separation concernant ces differents elements nous a amenes a resoudre de nombreux problemes d'interference. Ces methodes permettent la separation et le dosage des constituants des mineraux, ainsi que la recherche d'elements en traces dans les minerais, les roches, les sols et les materiaux carbonnes. Signalons pour terminer que cette technique peut egalement trouver son utilisation dans le domaine de l'analyse en milieu tres radio-actif. (auteur)

  19. Origin of the use of the word magma in Earth Sciences

    Science.gov (United States)

    Gohau, , G.

    1998-05-01

    The word magma was originally used in pharmacy (1694), and then in chemistry (1773).It took its modern geological significance only during the XIXth century.Although it is generally considered to have been first used in geology in 1879 (Roches eruptives, by Fouque and Michel-Levy), the word was already used by Fournet as early as 1838, and soon by Durocher (1845).Both supported an igneous origin of the granite, and were opposed to the metamorphic origin interpretation which, at that time, was dominant in France.Le mot magma, issu de la pharmacie (1694), et utilise par les chimistes des 1773, ne prend son sens moderne, en geologie, qu'au XIX^e siecle.Quoiqu'on retienne habituellement la date de 1879 (Roches eruptives, par Fouque et Michel-Levy), le terme apparait en fait des 1838, chez Fournet, puis chez Durocher a partir de 1845.Partisans de l'origine ignee du granite, ces deux auteurs s'opposent a la these dominante, en France, de l'origine metamorphique.

  20. Polymer article of manufacture

    Energy Technology Data Exchange (ETDEWEB)

    Newlove, J.C.; McDougall, L.A.

    1987-12-15

    It is an object of this invention to provide an article and its use to enhance the production of hydrocarbons from geologial reservoirs, more particularly from fractured formations. It has been an additional object to devise a composition for providing controlled release of a reagent downhole, in a pipeline, in other oil-containing environments or fluids. It has been discovered that it is possible to provide for the introduction of an additive reagent into a liquid hydrocarbon by providing solid polymeric bodies each comprising a polymeric matrix containing a substantially water insoluble reagent such as a wax crystal modifier, demulsifier, scale inhibitor, corrosion inhibitor, biocide, ashless dispersant, antioxidant and mixtures thereof. These bodies are, in use, positioned at a location where it is desired to release the reagent into the substantially hydrocarbon fluid and, upon contact with fluid in this location, active reagent is released into the fluid. Thus in accordance with this invention there is provided a solid polymeric body comprising a polymer matrix containing a substantially water-insoluble reagent leachable into a substantially hydrocarbon liquid environment. The object of this invention has been realized in specific form by beads comprising a copolymeric matrix of methylmethacrylate and methacrylic acid containing the behenyl half ester of a C/sub 24/-C/sub 28/ alkenyl succinic anhydride polymer and having a diameter ranging from 0.2 to 1 mm. Such beads, when introduced downhole in a hydraulic fracturing operation, were found to inhibit paraffin wax deposition.

  1. CACAO: A project for a laboratory for the production and characterization of thin radioactive layers

    Energy Technology Data Exchange (ETDEWEB)

    Bacri, C.O., E-mail: bacri@ipno.in2p3.f [Institut de Physique Nucleaire d' Orsay, 91406 Orsay Cedex, CNRS (UMR8608-IN2P3), Universite Paris-Sud (Paris XI) (France); Petitbon, V.; Pierre, S. [Institut de Physique Nucleaire d' Orsay, 91406 Orsay Cedex, CNRS (UMR8608-IN2P3), Universite Paris-Sud (Paris XI) (France)

    2010-02-11

    CACAO, Chimie des Actinides et Cibles radioActives a Orsay (actinide chemistry and radioactive targets at Orsay), is a project under construction that consists of the installation of a hot laboratory dedicated to the production and characterization of thin radioactive layers. The project aims to be a joint CNRS-CEA national laboratory to overcome difficulties related mainly to safety issues and to the lack of knowledge and potential manpower. The first goal is to fulfill, at least, the needs of the whole French community, and to be able to coordinate the different activities related to radioactive targets. For this purpose, itis important to be complementary to already existing international installations. Inside this framework, it will of course be possible to produce and/or characterize targets for other users.

  2. CACAO: A project for a laboratory for the production and characterization of thin radioactive layers

    Science.gov (United States)

    Bacri, C. O.; Petitbon, V.; Pierre, S.; Cacao Group

    2010-02-01

    CACAO, Chimie des Actinides et Cibles radioActives à Orsay (actinide chemistry and radioactive targets at Orsay), is a project under construction that consists of the installation of a hot laboratory dedicated to the production and characterization of thin radioactive layers. The project aims to be a joint CNRS-CEA national laboratory to overcome difficulties related mainly to safety issues and to the lack of knowledge and potential manpower. The first goal is to fulfill, at least, the needs of the whole French community, and to be able to coordinate the different activities related to radioactive targets. For this purpose, itis important to be complementary to already existing international installations. Inside this framework, it will of course be possible to produce and/or characterize targets for other users.

  3. CACAO: A project for a laboratory for the production and characterization of thin radioactive layers

    International Nuclear Information System (INIS)

    Bacri, C.O.; Petitbon, V.; Pierre, S.

    2010-01-01

    CACAO, Chimie des Actinides et Cibles radioActives a Orsay (actinide chemistry and radioactive targets at Orsay), is a project under construction that consists of the installation of a hot laboratory dedicated to the production and characterization of thin radioactive layers. The project aims to be a joint CNRS-CEA national laboratory to overcome difficulties related mainly to safety issues and to the lack of knowledge and potential manpower. The first goal is to fulfill, at least, the needs of the whole French community, and to be able to coordinate the different activities related to radioactive targets. For this purpose, itis important to be complementary to already existing international installations. Inside this framework, it will of course be possible to produce and/or characterize targets for other users.

  4. CACAO facility. Radioactive targets at Orsay

    International Nuclear Information System (INIS)

    Bacri, C.O.; Petitbon-Thevenet, V.; Mottier, J.; Lefort, H.; Durnez, A.; Fortuna, F.

    2014-01-01

    CACAO, Chimie des Actinides et Cibles radioActives a Orsay (actinide chemistry and radioactive targets at Orsay), is a new laboratory dedicated to the fabrication and characterization of radioactive targets. It is supported by the radiochemistry group and the stable target service of the IPNO. The recurring needs of physicists working in the nuclear fuel cycle physics and the growing difficulties to obtain radioactive targets elsewhere were the main motivating factors behind the construction of this new laboratory. The first targets of 235,238 U and 232 Th have already been prepared although the full operating licenses still need to be obtained. In this paper, the installation and the equipment of CACAO will be described. An extensive study of a U test target fabricated by the CACAO laboratory has been performed and results are reported here. The different techniques used to characterize the deposit are presented and the outcome is discussed. (author)

  5. Les savants genevois dans l'Europe intellectuelle du XVIIe au milieu du XIXe siècle

    CERN Document Server

    1987-01-01

    Après une introduction sur l'essor de la science genevoise par Jean STAROBINSKI et un chapitre sur l'Europe savante (1700-1850) par Jacques ROGER, sont présentés les travaux et recherches dans les différentes disciplines: l'astronomie par Marcel GOLAY, les mathématiques par Pierre SPEZIALI, la physique par Pierre SPEZIALI, la chimie par Armand BUCHS, la géologie par Albert V. CAROZZI, la zoologie par Marino BUSCAGLIA, la botanique par Jacques NAEF; suivis des biographies des savants genevois par Jean-Michel PICTET, avec petits portraits; notes; index; photos et fac-similés de documents; bibliographies par chapitre. Ouvrage publié par l'Association pour le Musée d'histoire des sciences de Genève, présidé par Jacques TREMBLEY.

  6. Le Feu et ses Usages Militaires

    Directory of Open Access Journals (Sweden)

    Finó, J. F.

    1970-12-01

    Full Text Available LE feu a toujours été une arme puissante. L'homme préhistorique, les Assyriens, les Grecs, les Byzantins, les Arabes, les bombes incendiaires de notre aviation, autant d'exemples de son usage militaire dans des pays et des temps fort divers. De plus, une de ses variantes, le feu grégeois pulvérulent, a été à l'origine de la poudre à canon. Il a donc paru intéressant de rassembler quelques données à ce sujet et de rappeler briévement la production des feux de guerre, leur lancement et la défense contre ses effets. Accessoirement, de dire quelques mots sur une autre branche de la chimie de guerre: les gaz asphyxiants.

  7. Lipochimie et innovations

    OpenAIRE

    Alfos Carine

    2003-01-01

    Peut-on parler d’un nouvel âge d’or pour les produits à base de ressources végétales renouvelables et notamment pour les huiles ? Porteurs de performances spécifiques et de caractéristiques plus écologiquement correctes, leur emploi ouvre à l’industrie un potentiel d’innovations auquel participe le département de chimie et rhéologie de l’Iterg. La prise de conscience collective, associée aux évolutions des réglementations françaises et européennes, devrait conduire les industries à prendre de...

  8. Physique et humanités scientifiques. Autour de la réforme de l'enseignement de 1902. Études et documents

    OpenAIRE

    Tiberghien, Andrée

    2006-01-01

    Cet ouvrage porte sur la réforme de l'enseignement expérimental de la physique et de la chimie pour plus de 60 ans. Une première partie analyse cette réforme et la seconde comporte des documents originaux. Dans l'esprit de cette réforme, les sciences doivent désormais faire partie de la culture, on parle d'« humanités scientifiques ». Les concepteurs introduisent un renouveau pédagogique où l'expérience et la méthode inductive ont une place prépondérante. Ce livre met en évidence de façon trè...

  9. Acrylate intercalation and in situ polymerization in iron-, cobalt-, or manganese-substituted nickel hydroxides.

    Science.gov (United States)

    Vaysse, C; Guerlou-Demourgues, L; Duguet, E; Delmas, C

    2003-07-28

    A chimie douce route based on successive redox and exchange reactions has allowed us to prepare new hybrid organic-inorganic materials, composed of polyacrylate macromolecules intercalated into layered double hydroxides (LDHs), deriving from Ni(OH)(2). Monomer intercalation and in situ polymerization mechanisms have appeared to be strongly dependent upon the nature of the substituting cation in the slabs. In the case of iron-based LDHs, a phase containing acrylate monomeric intercalates has been isolated and identified by X-ray diffraction and infrared spectroscopy. Second, interslab free-radical polymerization of acrylate anions has been successfully initiated using potassium persulfate. In cobalt- or manganese-based LDHs, one-step polymerization has been observed, leading directly to a material containing polyacrylate intercalate.

  10. Imaging the experiments on respiration and transpiration of Lavoisier and Séguin: two unknown drawings by Madame Lavoisier.

    Science.gov (United States)

    Beretta, Marco

    2012-01-01

    This paper presents two hitherto unknown drawings by Marie-Anne-Pierrette Lavoisier dating to the early 1790s that illustrate the experiments on respiration and transpiration of her husband Antoine-Laurent Lavoisier and his assistant Armand Séguin. These works may be associated with the well-known sepia drawings that were published for the first time by Edouard Grimaux in 1888. Details contained in these newly discovered drawings by M.me Lavoisier provide fresh evidence as to the nature and aims of Lavoisier's innovative experiments. As we will show, these drawings were intended to illustrate the collection of papers on respiration being prepared by Lavoisier for his Mémoires de physique et de chimie (1792-1805).

  11. [Fourcroy and pharmaceutical journals].

    Science.gov (United States)

    Bonnemain, Bruno

    2011-04-01

    Cadet de Gassicourt wrote a brief Eloge of Fourcroy in January 1810 as he died in December of 1809. Fourcroy had a major role concerning the new ideas on the place of pharmacy at the beginning of the 19th century. Fourcroy has had a key influence for the start of several pharmaceutical journals that wanted to emphasize the link between the new chemistry and pharmacy. None of these journals created with him will survive and one has to wait for 1909 to see the creation, without Fourcroy, of a new pharmaceutical journal, the "Journal de Pharmacie" that will become "Journal de Pharmacie et des Sciences accessoires", then "Journal de Pharmacie et de Chimie", before taking the name of"Annales Pharmaceutiques Françaises", the present official journal of the French Academy of Pharmacy. In spite of the essential role of Fourcroy at the start of pharmaceutical journals, Cadet did not even mention it in his Eloge of 1810.

  12. [Precarious matters. The radium economy, episteme of risk and the emergence of tracer technique in national socialism].

    Science.gov (United States)

    von Schwerin, Alexander

    2009-01-01

    Following the traces of radioactive material is--as scholars have recently shown--a valuable historical approach in order to evaluate the material 'factor' of science in action. Even though the origins of materials like radium and artificial isotopes are quite different, their circulation is interconnected. A material pathway can be drawn from the radium industry to the scientific rise of artificial isotopes as indicator substances in the 1930s, continuing to the building of networks by German scientists working for the war efforts. Also, this pathway reveals the role of radiation protection in establishing that material culture. Finally, the dynamics of material traces and institutional linkages is shown by the tracer work of biophysicists and radiation biologists working at the Genetic Department of the Kaiser Wilhelm Institute for Brain Research in Berlin and at the Institut de Chimie Nucléaire at Paris, which at that time was occupied by German troops.

  13. [Clarification on publications concerning the synthesis of acetylsalicylic acid].

    Science.gov (United States)

    Lafont, O

    1996-01-01

    Charles Frédéric Gerhardt (1816-1856) mentioned in his Traité de chimie Organique (1854) a publication, in French (realized in 1852 but published in 1853) entitled "Researches on anhydrous organic acids" in which, was reported the reaction of sodium salicylate with acetyl chloride. He thought that the reaction product was an acid anhydride, but obtained really crude acetylsalicylic acid. Later on, but also in 1853, a publication in german, by the same author related the same experiments. Surprisingly only the second publication has been mentioned in most of the historical studies on the subject. Acetyl salicylic acid was identified and synthesised in 1859 by von Gilm by another method and the product obtained by Gerhardt was identified to it in 1869.

  14. [The story of Annales pharmaceutiques françaises. 1809-2009].

    Science.gov (United States)

    Chast, F

    2009-11-01

    The Annales pharmaceutiques françaises is 200 years old. Initially, in 1809, the Bulletin de pharmacie was the organ of the Société de pharmacie de Paris. The journal was one of the dynamic events stimulated by the law of Germinal in year XI of the French revolution (1803). Its readership increased tremendously, rapidly making it the first regular journal in the pharmaceutical world. In 1984 it became the Journal de pharmacie et chimie published for a century. It was in 1943 that the journal took on its current name of the Annales pharmaceutiques françaises. The journal is now the official organ of the French National Academy of Pharmacy. The six annual issues are supplemented by an internet diffusion allowing readers access in all French-speaking countries.

  15. Low-temperature solvothermal approach to the synthesis of La4Ni3O8 by topotactic oxygen deintercalation.

    Science.gov (United States)

    Blakely, Colin K; Bruno, Shaun R; Poltavets, Viktor V

    2011-07-18

    A chimie douce solvothermal reduction method is proposed for topotactic oxygen deintercalation of complex metal oxides. Four different reduction techniques were employed to qualitatively identify the relative reduction activity of each including reduction with H(2) and NaH, solution-based reduction using metal hydrides at ambient pressure, and reduction under solvothermal conditions. The reduction of the Ruddlesden-Popper nickelate La(4)Ni(3)O(10) was used as a test case to prove the validity of the method. The completely reduced phase La(4)Ni(3)O(8) was produced via the solvothermal technique at 150 °C--a lower temperature than by other more conventional solid state oxygen deintercalation methods.

  16. Découvre les sciences avec les petits débrouillards 39 expériences faciles et amusantes

    CERN Document Server

    2006-01-01

    Comment plier des os sans les casser ? Peut-on enlever la rouille d’un vieux clou ? Est-ce facile de multiplier une plante ? Comment fabriquer un mini-geyser ? Un anneau de papier qui n’a qu’une seule face, est-ce possible ? Voilà quelques-unes des 40 énigmes et expériences que ce livre propose aux jeunes lecteurs curieux de comprendre le monde et les phénomènes qui les entourent. Une initiation aux grands principes de la physique, de la chimie et de la biologie, pour s’étonner et aussi épater ses amis ou sa famille.

  17. Que peut-on voir avec des neutrons? Une introduction pour des non spécialistes

    Science.gov (United States)

    Schweizer, J.

    2005-11-01

    Le neutron est une particule élémentaire qui a été découverte en 1932 par James Chadwick. Ses caractéristiques principales sont résumées dans le tableau I. Il a été utilisé pour la première fois par Clifford Shull en 1946 comme outil pour des expériences de diffusion. Cette technique s'est depuis constamment développée pour concerner tous les aspects de la matière condensée: physique, chimie, matériaux, biologie. Il s'agit d'un outil tout à fait exceptionnel car le neutron possède des propriétés uniques et particulièrement adaptées pour ces études.

  18. Nouvelle méthodologie de synthèse de molécules à potentiel diurétique

    OpenAIRE

    Ouellet, Simon

    2007-01-01

    [Synthèse combinatoire ]. Le présent mémoire propose l'élaboration d'une nouvelle méthodologie de synthèse de molécules ayant un potentiel diurétique, et ciblant plus particulièrement les cotransporteurs cations-chlorures, responsables du mouvement couplé des ions sodium et/ou potassium avec celui du chlorure dans plusieurs types de cellules dont celles des néphrons. La première partie est consacrée à une description de la chimie combinatoire, aux travaux antérieurs effectués dans notre la...

  19. De l’intuition à l’audace, l’œuvre de Pierre Potier

    OpenAIRE

    Calvo, Fabien; Roux, Muriel Le

    2007-01-01

    À 71 ans, après plus de quarante années vouées à la recherche de médicaments, à l’Institut de Chimie des substances naturelles du CNRS, Pierre Potier s’est éteint alors qu’il espérait voir aboutir ses travaux pour le traitement du diabète de type 2 (« diabète gras »). Pharmacien et chimiste, ses travaux ont permis la diffusion mondiale de deux agents thérapeutiques majeurs, la Navelbine® et le Taxotère®. Ces médicaments sont des anti-cancéreux parmi les plus actifs et les plus vendus dans le ...

  20. Reconnaissance de formes moléculaires dans les relations structure-activité

    OpenAIRE

    Mathis , Hervé

    1992-01-01

    Non disponible / Not available; Cette thèse présente un logiciel qui a pour but de mieux comprendre les relations entre caractéristiques structurales et propriétés thérapeutiques de molécules envisagées comme médicaments. L'idée majeure est de soumettre une famille de composés, d'une part à des calculs de chimie quantique, d'autre part à des méthodes de reconnaissance de formes, afin d'observer si certaines propriétés moléculaires sont discriminantes vis-à-vis d'une activité pharmacologique m...

  1. ELYSE, a new picosecond electron accelerator at Orsay

    International Nuclear Information System (INIS)

    Belloni, J.D.; Gaillard, M.; Monard, H.; Larbre, J.-P.; Gobert, F.; Mostafavi, M.; Lampre, I.; Marignier, J.-L.

    2003-01-01

    ELYSE is a new instrument allowing to study fast kinetics processes at picosecond range by the complementary techniques of pulse radiolysis and laser photochemistry which was installed by the Laboratoire de Chimie Physique, University Paris-Sud, at Orsay. It was designed and constructed by the Linear Accelerator Laboratory, Orsay. The accelerator is a RF photocathode electron gun type which will deliver electron pulses of less than 5 ps FWHM. The Cs 2 Te cathode was chosen because of its high efficiency and long life time. Photoelectrons are generated by a picosecond synchronized laser system with a normal incidence. The charge per pulse is 1 nC with a dark current less than 1 % and a repetition frequency 1 to 50 Hz. Other detailed specifications of the accelerator, of the laser and of the optical spectroscopy detection set-up are described

  2. Neutron activation analysis: A primary method of measurement

    Energy Technology Data Exchange (ETDEWEB)

    Greenberg, Robert R., E-mail: robert.greenberg@nist.gov [National Institute of Standards and Technology, Gaithersburg, MD 20899-8395 (United States); Bode, Peter, E-mail: p.bode@tudelft.nl [Delft University of Technology, Delft (Netherlands); De Nadai Fernandes, Elisabete A., E-mail: lis@cena.usp.br [Centro de Energia Nuclear na Agricultura, Universidade de Sao Paulo, Piracicaba, SP (Brazil)

    2011-03-15

    Neutron activation analysis (NAA), based on the comparator method, has the potential to fulfill the requirements of a primary ratio method as defined in 1998 by the Comite Consultatif pour la Quantite de Matiere - Metrologie en Chimie (CCQM, Consultative Committee on Amount of Substance - Metrology in Chemistry). This thesis is evidenced in this paper in three chapters by: demonstration that the method is fully physically and chemically understood; that a measurement equation can be written down in which the values of all parameters have dimensions in SI units and thus having the potential for metrological traceability to these units; that all contributions to uncertainty of measurement can be quantitatively evaluated, underpinning the metrological traceability; and that the performance of NAA in CCQM key-comparisons of trace elements in complex matrices between 2000 and 2007 is similar to the performance of Isotope Dilution Mass Spectrometry (IDMS), which had been formerly designated by the CCQM as a primary ratio method.

  3. Biological applications of the Moessbauer effect; Applications de l'effet Mossbauer a la biologie

    Energy Technology Data Exchange (ETDEWEB)

    Boulay, P [CEA Bruyeres-le-Chatel, 91 (France)

    1968-12-01

    The applications of Moessbauer spectrometry in the fields of physics and chemistry have been increasing steadily since its discovery in 1958. Attempts have been made to find applications in biology. Two possibilities of investigation exist in this field: the study of mechanical or vibrational movements in certain animal organs, and the determination of the organic molecular structure in a biological context. An example is given of each of these possibilities. (author) [French] Les applications de la spectrometrie Mossbauer dans le domaine de la physique et de la chimie n'ont cesse de progresser depuis sa decouverte en 1958. Des essais d'application a la biologie ont ete entrepris. Dans ce domaine il existe deux possibilites d'investigation: l'etude des mouvements mecaniques ou vibratoires de certaines organes d'animaux, et la determination de la structure moleculaire organique a destinee biologique. Un exemple est donne de chacune de ces possibilites. (auteur)

  4. Claude Grignon, Claude Kordon, Sciences de l'homme et sciences de la nature. Essais d'épistémologie comparée

    OpenAIRE

    Rogel, Thierry

    2011-01-01

    Cet ouvrage est composé d'un ensemble de contributions faites au cours du séminaire « Sciences de l'homme et sciences de la nature » qui s'est tenu à la Maison des Sciences de l'Homme de 2003 à 2007. Ce séminaire portait sur les questions de l'unité des sciences et de la scientificité des « sciences de l'homme ». Les domaines abordés sont multiples et couvrent un large spectre de sciences - mathématiques, physique, chimie, cosmologie, archéologie, biologie, épidémiologie, économie, sociologie...

  5. Suitability aero-geophysical methods for generating conceptual soil maps and their use in the modeling of process-related susceptibility maps

    Science.gov (United States)

    Tilch, Nils; Römer, Alexander; Jochum, Birgit; Schattauer, Ingrid

    2014-05-01

    . Previous studies show that, especially with radiometric measurements, the two-dimensional spatial variability of the nature of the process-relevant soil, close to the surface can be determined. In addition, the electromagnetic measurements are more important to obtain three-dimensional information of the deeper geological conditions and to improve the area-specific geological knowledge and understanding. The validation of these measurements is done with terrestrial geoelectrical measurements. So both aspects, radiometric and electromagnetic measurements, are important and subsequently, interpretation of the geophysical results can be used as the parameter maps in the modeling of more realistic susceptibility maps with respect to various processes. Within this presentation, results of geophysical measurements, the outcome and the derived parameter maps, as well as first process-oriented susceptibility maps in terms of gravitational soil mass movements will be presented. As an example results which were obtained with a heuristic method in an area in Vorarlberg (Western Austria) will be shown. References: Schwarz, L. & Tilch, N. (2011): Why are good process data so important for the modelling of landslide susceptibility maps?- EGU-Postersession "Landslide hazard and risk assessment, and landslide management" (NH 3.6), Vienna. [http://www.geologie.ac.at/fileadmin/user_upload/dokumente/pdf/poster/poster_2011_egu_schwarz_tilch_1.pdf] Tilch, N. & Schwarz, L. (2011): Spatial and scale-dependent variability in data quality and their influence on susceptibility maps for gravitational mass movements in soil, modelled by heuristic method.- EGU-Postersession "Landslide hazard and risk assessment, and landslide management" (NH 3.6); Vienna. [http://www.geologie.ac.at/fileadmin/user_upload/dokumente/pdf/poster/poster_2011_egu_tilch_schwarz.pdf

  6. Integrative quantification and balancing of contaminant fluxes in urban groundwater, case study Darmstadt; Integrative Quantifizierung und Bilanzierung von Stofffluessen in urbanem Grundwasser am Beispiel Darmstadts

    Energy Technology Data Exchange (ETDEWEB)

    Beier, M.; Ebhardt, G.; Schiedek, T. [Technische Universitaet Darmstadt, Institut fuer Angewandte Geowissenschaften, Darmstadt (Germany)

    2007-09-15

    The qualitative and quantitative impact of a city on groundwater is presented in the case study of Darmstadt. The impact of land use on groundwater quality in Darmstadt is higher than the impact of background geological processes. The occurrence of Cl, B and Fe is only influenced by land use, while EC, HCO{sub 3} and PO{sub 4} are controlled by geology and land use. An integrative, spatially differentiating quantification of mass fluxes shows that e. g. Cl and B are introduced from urban sources such as leaking sewers and road salting. Input is highest under industrial areas (Cl 317 mg/d . m{sup 2}, B 0,6 mg/d . m{sup 2}). For N{sub tot} agricultural input (114 mg/d . m{sup 2}) is more important than urban input with a maximum of 14 mg/d . m{sup 2}. Comparing overall urban input with estimated urban input, it can be concluded that there are additional sources for HCO{sub 3}, Ca, Mg, SO{sub 4}, Na, Cl, B and NO{sub 3}, which are not included in the estimated input (e. g. geogenic sources, fill material, industrial sources and degradation processes). PO{sub 4} and N{sub tot} on the other hand are being degraded and COD is consumed. A decrease of concentrations downstream from the city can be ascribed to diving plumes. (orig.) [German] Die qualitativen und quantitativen Einfluesse einer Stadt auf das Grundwasser werden am Beispiel Darmstadts beschrieben. Die Landnutzung hat in Darmstadt einen staerkeren Einfluss auf die Grundwasserqualitaet als die Geologie. Cl, B und Fe sind nur von der Nutzung abhaengig, waehrend Lf, HCO{sub 3} und PO{sub 4} von Geologie und Nutzung beeinflusst werden. Eine integrative, raeumlich differenzierende Quantifizierung der Massenfluesse zeigt, dass z. B. Cl und B aus urbanen Quellen wie Abwasserexfiltration und Streusalz eingetragen werden. Die groessten Eintraege erfolgen unter Industrieflaechen (Cl 317 mg/d . m{sup 2}, B 0,6 mg/d . m{sup 2}). Fuer N{sub ges} ist der landwirtschaftliche Eintrag mit bis zu 114 mg/d . m{sup 2} von

  7. Integration of seismic reflection and geologically balanced profiles; Integration reflexionsseismischer und geologisch bilanzierter Profile

    Energy Technology Data Exchange (ETDEWEB)

    Lambrecht, A. [Trappe Erdoel Erdgas Consultant, Isernhagen (Germany)

    1998-12-31

    Geophysics and geology employ different kinds of techniques in order to preserve the underground structure. These techniques are based on different sets of data, i.e. seismic or geological data. A sensible combination of the two techniques should produce a better model of the ground structure. This study attempts to integrate geologically balanced profiles and seismic reflection data. A balanced geological profile can than be compared with seismic reflection data measured in the field. The geological model is then changed into a seismic model of the underground by means of seismic modeling. Synthetic modeling is based on the acquisition of available field data. The synthetic stack section or the synthetic migration image are then compared to the field data. Deviations between the two can be attributed to speed errors and the fact that balances will never give an unequivocal solution but always present a group of solutions. (orig. MSK). [Deutsch] In der Geophysik und der Geologie werden verschiedene Techniken verwendet, um die Untergrundstruktur zu erhalten. Diese Techniken basieren auf verschiedenen Datensaetzen, z.B. seismische und geologische Daten. Eine sinnvolle Kombination der Techniken sollte ein besseres Abbild des Untergrundes liefern. In dieser Studie wird ein Versuch unternommen geologisch bilanzierte Profile und reflexionsseismische Daten zu integrieren. Soll ein bilanziertes geologisches Profil mit im Feld gemessenen reflexionsseismischen Daten verglichen werden, dann wird das geologische Modell mit Hilfe der seismischen Modellierung in ein seismisches Abbild des Untergrundes verwandelt. Dabei wird die synthetische Modellierung entsprechend der Aquisition der vorliegenden Felddaten durchgefuehrt. Die synthetische Stapelsektion oder das synthetische Migrationsimage werden anschliessend mit den Felddaten verglichen. Abweichungen zwischen beobachteten und Felddaten haben ihre Ursachen sowohl in Geschwindigkeitsfehlern, als auch in der Tatsache, dass eine

  8. Natural gas qualities in the Southern Permian basin; Die Erdgasqualitaeten im suedlichen Permbecken

    Energy Technology Data Exchange (ETDEWEB)

    Gerling, P.; Kockel, F. [BGR, Hannover (Germany); Lokhorst, A.; Geluk, M.C. [TNO, Haarlem (Netherlands); Nicholson, R.A. [British Geological Survey, Nottingham (United Kingdom); Laier, T. [Danmarks og Groenlands Geologiske Undersoegelse, Kopenhagen (Denmark); Pokorski, J. [Panstwowy Instytut Geologiczny, Warsaw (Poland)

    1998-12-31

    There is a substantial amount of molecular and isotopic gas data in the literature but mostly in the archives of companies and geological services. As the geological services of most European countries traditionally contain (confidential and non-confidential) data on geology and resources these institutions from Great Britain, the Netherlands, Denmark, Poland and Germany decided to compile molecular and isotopic natural gas data from the area of the Southern European Permian basin. The partially EU-subsidised project was carried out between 1994 and 1997 (LOKHORST ed. 1998) The atlas is based on existing data and also on newly determined molecular and isotopic gas parameters. Ring analyses of national and international standard gases ensure the quality and comparability of the data thus obtained. The aim of the ``stocktaking`` of natural gas was to describe the gas qualities from the Southern North Sea in the West to the Eastern borders of Poland, to characterise them genetically and to relate the to the geological environment. (orig.) [Deutsch] Ein substantieller Anteil von molekularen und isotopischen Gasdaten existiert, teilweise in der Literatur, vor allem aber in den Archiven der Firmen und der geologischen Dienste. Da die geologischen Dienste der meisten europaeischen Laender traditionell (oeffentliche und vertrauliche) Daten ueber die Geologie und Rohstoffe vorhalten, haben sich diese Institutionen aus Grossbritanien, den Niederlanden, Daenemark, Polen und Deutschlands entschlossen, molekulare und isotopische Erdgasdaten aus dem Bereich des suedlichen europaeischen Permbeckens zu kompilieren. Das partiell von der EU gefoerderte Projekt wurde in den Jahren 1994 bis 1997 durchgefuehrt (LOKHORST ed. 1998). Ausser auf bereits vorhandenen Daten beruht der Atlas auf etwa 200 Neu-Bestimmungen molekularer und isotopischer Gasparameter. Ringanalysen nationaler und internationeler Standardgase gewaehrleisteten die Qualitaet und die Vergleichbarkeit der gewonnenen

  9. Systematic analysis of geothermal plants. Influence of temperatures in consumer systems on the specific cost of the distributed heat; Systemanalytische Erfassung von Nutzungsanlagen hydrogeothermaler Ressourcen. Einfluss der Temperaturen in den Abnehmersystemen auf den Waermegestehungspreis

    Energy Technology Data Exchange (ETDEWEB)

    Schallenberg, K [GeoForschungsZentrum Potsdam (Germany)

    1997-12-01

    On the basis of a general investigation of the impact of geological situation, thermal water loop and consumer structure on the economy of heating systems, different geothermal plants are analysed in detail. In the study, for example, variations of the temperature conditions in district heating systems were considered while the geologic conditions are maintained. It is shown that the specific costs calculated for the distributed heat are sensitive to the amount of heat extracted from the Earth`s interior. Therefore, it was necessary to make assumptions for the duration curve of the consumer system. An exponential duration curve was verified by comparison with data from an existing district heating system. The calculated specific heat costs for different network layouts are transformed finally into an equivalent investment potential. The results clearly indicate the possibilities for an optimization of the system when investments into the heating network would be made. (orig.) [Deutsch] Hydrogeothermale Nutzungsanlagen wurden auf Basis der Einflussgroessen Geologie, Thermalwasserkreis und Abnehmerstruktur systemanalytisch erfasst. Daraus ergibt sich die Grundlage zum Vergleich verschiedener Anlagen. Nachhaltige Einfluesse auf die Wirtschaftlichkeit von Geothermieanlagen ergeben sich aus der Betriebsweise der Abnehmerstruktur. Die dargestellten Untersuchungen zielen deshalb zunaechst auf die Variation der Temperaturparameter des Netzes und deren Einfluss auf die Waermegestehungskosten ab. Bei diesem Ansatz wurden zunaechst die geologischen Eingangsgroessen konstant gehalten. Grundlage der statischen Kostenrechnung in Anlehnung an VDI 2067 ist eine Kostenzusammenstellung der Einzelkomponenten einer geothermischen Heizzentrale. Um den geothermischen Beitrag zur Waermeversorgung moeglichst genau zu beschreiben, ist die Kenntnis von geordneten Jahresganglinien der Abnehmersysteme erforderlich. Zur mathematischen Beschreibung diente eine Exponentialfunktion, deren

  10. The coal mining industry in the north of Colorado and Arizona; Steinkohlenbergbau im Norden Colorados und Arizonas

    Energy Technology Data Exchange (ETDEWEB)

    Dressel, S.; Tschauder, A. [Kali und Salz AG Werk Werra, Philippsthal (Germany)

    2000-10-12

    A study tour in autumn 1999, which was undertaken following the award of the Helmuth Burkhardt prize of Wirtschaftsvereinigung Bergbau e.V. to the authors, comprised visits to potash, molybdenum, lead, zinc, copper ore and coal mines in the mid-west of the USA. The Black Mesa Mine and Kayenta Mine of Peabody Western Coal Company in the Navajo Reserve in the north of Arizona, the Trapper Mine Inc. near Craig and the Twentymile Coal Company near Steamboat Springs, Colorado are described in this report. In addition to a brief description of the geology the coal winning is considered in greater detail. The Twentymile Coal Company was asked to explain the reasons for the successful operation of the colliery, which produces more than 5 mill. t anthracite per year by long wall working. (orig.) [German] Eine Exkursion im Herbst 1999, die durch die Verleihung des Helmuth-Burkhard-Preises der Wirtschaftsvereinigung Bergbau e.V. an Bergassessor Andreas Tschauder zustande kam, fuehrte zu Kali-, Molybdaen-,Blei-, Zink-, Kupfererz- sowie Steinkohlenbergwerken im Mittleren Westen der USA. In diesem Bericht wird auf die Steinkohlenbergwerke Black Mesa Mine und Kayenta Mine der Peabody Western Coal Company im Navajo Reservat im Norden Arizonas, der Trapper Mine Inc. bei Craig sowie der Twentymile Coal Company, nahe Steamboat Springs, Colorado, eingegangen. Neben einer kurzen Abhandlung ueber die Geologie wird die Gewinnung naeher betrachtet. Bei der Twentymile Coal Company wird die Frage gestellt, welches die Gruende fuer die erfolgreiche Arbeit des Bergwerks sind, die im Langfrontabbau pro Jahr mehr als 5 Mill. t Glanzkohle gewinnt. (orig.)

  11. Study in laboratory of the influence of temperature on clays creep

    International Nuclear Information System (INIS)

    Boisson, J.Y.; Billotte, J.; Norotte, V.

    1993-01-01

    This study is a research programme on safety of radioactive waste disposal. The objective of the research carried out was the study of the long term effects of the temperature variations on the volume and the texture of clayed soils, notably as function of their initial petrophysical and petrographical characteristics and their preconsolidation state. From the experimental point of view, this study is based on the observation of the volumetrical deformation of samples subjected to thermal loading within 20 and 110 deg C temperature range with periodical measurements of their permeability in an oedometric cell. A complete textural study before and after the experiments allows for a continuous appreciation of the evolution of the texture. A preliminary bibliographical review has shown that the clays characteristics evolution and their uniaxial volumic strain under different temperatures loadings may exhibit an expansive or compactive behaviour due to temperature increase. Some of the parameters such as water content, consolidation state, plasticity, mineralogy and time plays a major part and have been criteria for the choice of four clays for the experimental phase. The experimental device, used and conceived at the Centre de Geologie de l'Ingenieur is a classical oedometric cell with specific modifications due to the very long term tests at high temperatures. The main obtained results are: a compressibility increase between 20 and 110 deg C; a creep module evolution with temperature; a noteworthy creep showing the importance of the time in the strain measurement; an analogy between mechanical consolidation and thermal consolidation ; an highly irreversible behaviour during a cooling phase; a modification of the structure material due to the temperature, but different and less important than modifications due mechanical stresses; the intrinsic permeability appears to be practically independent of the imposed thermal variations

  12. Restoration of ecological priority areas in planning of post-mining landscape. Pt. 2. Final report; Schaffung oekologischer Vorrangflaechen bei der Gestaltung der Bergbaufolgelandschaft. T. 2. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, D.; Haubold-Rosar, M.; Katzur, J.; Landeck, I.; Mueller, L.; Ziegler, H.D.

    1995-11-01

    For the development of biotope- and species-rich man-made landscapes formed by the principles of landscape aesthetics and sustained yield a well-balanced relation of useful, protected and compensating ecosystems is required. The research area includes three surface mining-districts (areas of restoration) and their environment in the Southwest of the Niederlausitzer mining region with an area of 540 km{sup 2}. Working mainpoints are: - analysis of site conditions, of flora and fauna, elaboration of digitised maps (geology, soil, ground water, surface waters, land use, landscape patterns ..) - showing and classifying of priority areas and web structures for nature protection - fundamentals of soil management and soil development - practical design concepts for three example areas and a nature reserve. The aims of nature protection are to be realised by an overlap system of areas in form of big priority areas, integrated web and small structures and an environmentally compatible land use in agriculture, forestry and water management. Required area and specific site conditions are available. Part 2 contains chapter 5 to 8. (orig.) [Deutsch] Fuer die Entwicklung biotop- und artenreicher, nachhaltig nutzbarer und aesthetisch gestalteter Kulturlandschaften ist ein ausgewogenes Verhaeltnis von Nutz-, Schutz- und Ausgleichsoekosystemen erforderlich. Untersuchungsgegenstand sind 3 grosse Tagebaukomplexe (Sanierungstagebaue) und ihr Umland im suedwestlichen Bereich des Niederlausitzer Abbauraumes mit einem Flaechenumfang von 540 km{sup 2}. Vier Schwerpunkte werden bearbeitet: - Analyse der Standortgrundlagen, der Flora und Fauna, Erarbeitung digitalisierter Karten (Geologie, Boden, Grundwasser, Oberflaechengewaesser, Flaechennutzung, Landschaftsstruktur ...) - Ausweisung und Einordnung von Vorrangflaechen und Verbundstrukturen fuer den Naturschutz - Grundlagen der Bodenmanipulation und Bodenentwicklung - Praktische Entwurfskonzepte fuer 3 Beispielsgebiete und ein

  13. Restoration of ecological priority areas in planning of post-mining landscape. Pt. 1. Final report; Schaffung oekologischer Vorrangflaechen bei der Gestaltung der Bergbaufolgelandschaft. T. 1. Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Wiedemann, D.; Haubold-Rosar, M.; Katzur, J.; Landeck, I.; Mueller, L.; Ziegler, H.D.

    1995-11-01

    For the development of biotope- and species-rich man-made landscapes formed by the principles of landscape aesthetics and sustained yield a well-balanced relation of useful, protected and compensating ecosystems is required. The research area includes three surface mining-districts (areas of restoration) and their environment in the Southwest of the Niederlausitzer mining region with an area of 540 km{sup 2}. Working mainpoints are: - analysis of site conditions, of flora and fauna, elaboration of digitised maps (geology, soil, ground water, surface waters, land use, landscape patterns ..) - showing and classifying of priority areas and web structures for nature protection - fundamentals of soil management and soil development - practical design concepts for three example areas and a nature reserve. The aims of nature protection are to be realised by an overlap system of areas in form of big priority areas, integrated web and small structures and an environmentally compatible land use in agriculture, forestry and water management. Required area and specific site conditions are available. Part 1 contains chapter 1 to 4. (orig.) [Deutsch] Fuer die Entwicklung biotop- und artenreicher, nachhaltig nutzbarer und aesthetisch gestalteter Kulturlandschaften ist ein ausgewogenes Verhaeltnis von Nutz-, Schutz- und Ausgleichsoekosystemen erforderlich. Untersuchungsgegenstand sind 3 grosse Tagebaukomplexe (Sanierungstagebaue) und ihr Umland, im suedwestlichen Bereich des Niederlausitzer Abbauraumes mit einem Flaechenumfang von 540 km{sup 2}. Vier Schwerpunkte werden bearbeitet: - Analyse der Standortgrundlagen, der Flora und Fauna, Erarbeitung digitalisierter Karten (Geologie, Boden, Grundwasser, Oberflaechengewaesser, Flaechennutzung, Landschaftsstruktur ...) - Ausweisung und Einordnung von Vorrangflaechen und Verbundstrukturen fuer den Naturschutz - Grundlagen der Bodenmanipulation und Bodenentwicklung - Praktische Entwurfskonzepte fuer 3 Beispielsgebiete und ein

  14. Les clusters moléculaires. Applications en catalyse homogène et hétérogène Molecular Clusters. Applications in Homogeneous and Heterogeneous Catalysis

    Directory of Open Access Journals (Sweden)

    Dorbon M.

    2006-11-01

    Full Text Available Le présent article ne prétend pas être une étude bibliographique complète. II ne s'agit que d'une synthèse dont le but est l'introduction à un secteur de la chimie encore jeune et surtout très vaste et plein d'avenir. Les clusters métalliques sont des composés constitués d'atomes métalliques liés entre eux et généralement entourés de ligands ; ils présentent à la fois certaines des caractéristiques des complexes uninucléaires d'une part et des métaux massiques d'autre part. D'un point de vue fondamental, la chimie des clusters représente un domaine encore neuf et particulièrement vaste. D'un point de vue pratique, leur principal intérêt réside dans le fait que bon nombre d'entre eux ont fait preuve de propriétés catalytiques remarquables tant en mode homogène qu'en mode hétérogène. Ils doivent être pris en considération par les industriels de la chimie car certains peuvent être impliqués dans des réactions aussi importantes que la synthèse de Fischer-Tropsch, l'hydrogénation des oléfines, la réaction de gaz à l'eau et la fixation biologique de l'azote atmosphérique. This article does not pretend to be an exhaustive bibliographic survey. It is merely a synthesis intended as an introduction to a sector of chemistry which is still young and especially is very vast and promising. Metal clusters are compounds made up of metal atours bonded together and generally surrounded by ligands. They have various characteristics of both mono-nuclear complexes and bulk metals. From a fundamental point of view, the chemistry of clusters is still a new and particularly vast field. From a practical point of view, the importance of clusters lies in the fact that a good number of them have shown proof of remarkable catalytic properties, both homogeneous and heterogeneous. They must henceforth be taken into consideration by chemical engineers because some of them may be involved in such important reactions as the Fischer

  15. Transparent but not open: glass roof of the courtyard of the Provinciehuis (provincial government building in Groningen

    Directory of Open Access Journals (Sweden)

    Michiel S. Verweij

    2008-04-01

    The late medieval Sint Maartens-school is the oldest building. Later additions are a record office from 1880-1881 (architect J. van Lokhorst, a wing dating from 1915-1917 (architect J.A.W. Vrijman and a caretaker's house also dating from 1915-1917. but executed with a facade from 1559 originating from another part of the city. The complex has two courtyards: one bearing the prosaic name Grote Snor. originally an alley between Singelstraat and Martinikerkhof, and one courtyard in the form of an isosceles triangle. This second courtyard was provided with a transparent roof in 2006. As the buildings on the second courtyard are all on the national monuments and historic buildings register, the Rijksdienst voor Archeologie. Cultuurlandschap en Monumenten (RACM played an advisory role in the planning preceding the execution. The RACM could agree to the principle of roofing. The courtyard had not been designed as such but had come into being because buildings had been erected in various periods and at a certain moment an interjacent plot was left. This residual space looked abandoned and was not part of the activity of the Provinciehuis, whereas in the year 2004 there was a need for extra floor area and a representative space. When the courtyard would be covered, these wishes could be fulfilled. The RACM served the municipality of Groningen, being the licence-issuing authority, with the following range of thought: a roof should not cause any material or constructive damage to the listed buildings; a transparent roof is to be preferred and ought to be subordinate to the historical architecture; as a result of the roof the courtyard will acquire a new and vital role in the official duties of the Provinciehuis; the users would be able to see. appreciate and enjoy the adjoining listed buildings better from the courtyard; roofing undoubtedly contributes to more intensive, improved use. and as a result, to the future value of the listed buildings. In addition, the RACM

  16. Periodificación en arqueología peruana: genealogía y aporía

    Directory of Open Access Journals (Sweden)

    2005-01-01

    Full Text Available Périodisation en archéologie péruvienne : généalogie et aporie Résumé: La périodisation est un point stratégique d’intersection entre la théorie et la recherche empirique. Son histoire au Pérou résume bien les débats expérimentés par l’archéologie péruvienne. La variété des périodisations postulées et pratiquées dans les Andes l’a transformée en un champ d’étude privilégié. Une fois assumée la réciprocit nécessaire entre le développement d’une discipline et la connaissance de son histoire, l’auteur se livre à cette enquête sur les principaux systèmes de periodisation, les affrontements entre les tendances et le panorama actuel. Ce n’est pas un travail théorique, mais plutôt historiographique sur un aspect spécifique de l’archeologie péruvienne. L’objectif est de faire une généalogie critique et fonctionnelle, c’est-à-dire présenter la genèse des schémas conceptuels utilisés aujourd’hui, leurs liens et leurs limites. La periodificación es un estratégico punto de intersección entre la propuesta teórica y la investigación empírica. Su historia resume bien los debates por los que ha atravesado la arqueología peruana. La variedad de periodificaciones postuladas y/o practicadas en el área central andina, las convierte en un privilegiado campo de estudio. Asumida la necesaria reciprocidad entre el avance de toda disciplina y el conocimiento de su historia, se plantea este recorrido por los principales sistemas de periodificación, los enfrentamientos entre tendencias y el panorama actual. No se trata de un enfoque teórico, antes bien historiográfico de un aspecto específico de la arqueología peruana. El objetivo es hacer una genealogía crítica y funcional, es decir presentar la génesis de los esquemas conceptuales actualmente utilizados, sus conexiones y límites. Periodization in Peruvian archaeology: genealogy and apory Abstract: Periodization is a strategic point of intersection

  17. New structure–activity relationships of chalcone inhibitors of breast cancer resistance protein: polyspecificity toward inhibition and critical substitutions against cytotoxicity

    Directory of Open Access Journals (Sweden)

    Rangel LP

    2013-09-01

    Full Text Available Luciana Pereira Rangel,1,2,* Evelyn Winter,1,3,* Charlotte Gauthier,1 Raphaël Terreux,4 Louise D Chiaradia-Delatorre,5 Alessandra Mascarello,5 Ricardo J Nunes,5 Rosendo A Yunes,5 Tania B Creczynski-Pasa,3 Sira Macalou,1 Doriane Lorendeau,1 Hélène Baubichon-Cortay,1 Antonio Ferreira-Pereira,2 Attilio Di Pietro11Equipe Labellisée Ligue 2013, BMSSI UMR 5086 CNRS/Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France; 2Department of General Microbiology, Institute of Microbiology, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil; 3Department of Pharmaceutical Sciences, PPGFAR, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil; 4Equipe BISI, BMSSI UMR 5086 CNRS/Université Lyon 1, Institut de Biologie et Chimie des Protéines, Lyon, France; 5Department of Chemistry, Federal University of Santa Catarina, Florianopolis, Santa Catarina, Brazil*These authors contributed equally to this workAbstract: Adenosine triphosphate-binding cassette subfamily G member 2 (ABCG2 plays a major role in cancer cell multidrug resistance, which contributes to low efficacy of chemotherapy. Chalcones were recently found to be potent and specific inhibitors, but unfortunately display a significant cytotoxicity. A cellular screening against ABCG2-mediated mitoxantrone efflux was performed here by flow cytometry on 54 chalcone derivatives from three different series with a wide panel of substituents. The identified leads, with submicromolar IC50 (half maximal inhibitory concentration values, showed that the previously identified 2'-OH-4',6'-dimethoxyphenyl, as A-ring, could be efficiently replaced by a 2'-naphthyl group, or a 3',4'-methylenedioxyphenyl with lower affinity. Such a structural variability indicates polyspecificity of the multidrug transporter for inhibitors. At least two methoxyl groups were necessary on B-ring for optimal inhibition, but substitution at positions 3, 4, and 5 induced cytotoxicity

  18. How an Anglo-American methodology took root in France.

    Science.gov (United States)

    Laszlo, Pierre

    2011-01-01

    French organic chemistry had a strong nationalistic bent in the immediate aftermath to World War II. It continued to bask in the glow of the pre-World War I Nobel prize awarded jointly in 1912 to Victor Grignard and Paul Sabatier. In addition, the influence of the two mandarins then in power, Charles Prévost at the Sorbonne and Albert Kirrmann, a Dean in Strasbourg who would be called upon as vice-director at the École normale supérieure in Paris, saw to it that the only theory of organic reactions, admissible in the classroom and in the laboratory, was Prévost's. As Mary Jo Nye has shown, a wall was erected against penetration of the ideas of the British school of Ingold and Hughes. Mechanistic chemistry, as was being vigorously studied by the contemporary Anglo-American physical organic chemists, was 'persona non grata' in France. Publication by Bianca Tchoubar, in 1960, of "Les mécanismes réactionnels en chimie organique" opened a breach. The irony was for Dr. Tchoubar, a militant member of the Communist Party and a lady of fierce opinions, to have become a propagandist for the Anglo-American school of mechanistic studies. Truth for her overruled political propaganda. Her little book was revolutionary in the French context of the times. Together with the GECO (Groupe d'étude de chimie organique) summer conferences pioneered by Guy Ourisson after his return from Harvard, it ushered in the new ideas. This historical essay, based on an in-depth study of Tchoubar's book, will include a portrait of this remarkable woman scientist. It will delve at some length into the renewal of French science initiated by De Gaulle's government after his return to power in 1958. The tension in the French scientific establishment of the sixties reflected two opposed versions of nationalism, the one conservative, Malthusian, inner-directed, the other forward-looking, eager for the recovery of national status, seeing a strong French science as a means for asserting national

  19. Combustion Modeling with the G-Equation Modélisation de la combustion avec l'équation de G

    Directory of Open Access Journals (Sweden)

    Peters N.

    2006-12-01

    Full Text Available Numerical investigations concerning the turbulent flame front propagation in Gasoline Direct Injection (GDI engines were made by implementing a flamelet model in the CFD code Fire. The advantage of this combustion model is the decoupling of the chemistry from the turbulent flow. For this purpose the combustion chamber has to be divided into a burned and an unburned area, which is realized by transporting a scalar field (G-Equation. The reference value defines the present averaged flame position. The complete reaction kinetics is calculated interactively with the CFD code in a one dimensional Representative Interactive Flamelet (RIF code. This combustion model was verified by simulating a 2. 0 l-2 V gasoline engine with homogeneous combustion where a parameter study was conducted to check the flamelet model for plausibility. Finally, the potential of this combustion model was investigated by simulating a hypothetical 2. 0 1-4 V GDI engine. Une investigation numérique relative à la propagation des fronts de flammes turbulents dans les moteurs à essence à injection directe (GDI a été menée en implantant un modèle de flameletdans le code 3D Fire. L'avantage de ce modèle de combustion est de découpler la chimie de l'écoulement turbulent en divisant la chambre de combustion en deux zones : brûlée et imbrûlée, à l'aide d'une équation de transport d'un scalaire (équation de G. Une valeur de référence de ce scalaire définit la position moyenne de la flamme. Une chimie complète est calculée interactivement avec le calcul 3D à l'aide d'un code monodimensionnel RIF (Representative Interactive Flamelet. Le modèle de combustion a été validé sur la simulation d'un moteur 2 litres à 2 soupapes en combustion homogène pour vérifier la représentativité de l'approche flamelet . Puis, le potentiel du modèle de combustion a été étudié en simulant un moteur modèle 2 litres 4 soupapes GDI.

  20. Atherosclerosis and atherosensitivity in two southwest Algerian desert rodents, Psammomys obesus and Gerbillus gerbillus, and in Rattus norvegicus

    Directory of Open Access Journals (Sweden)

    El-Aoufi S

    2012-09-01

    Full Text Available Salima El-Aoufi,1 Mohamed-Amine Lazourgui,1 Lakhdar Griene,2 Boubekeur Maouche31Laboratoire de Biologie et de Physiologie des Organismes/MMDED, Faculté des Sciences Biologiques, USTHB, El-Alia, Dar El Beida, Algeria; 2Laboratoire d'Hormonologie, Centre Pierre et Marie Curie, C.H.U Mustapha, Algeria; 3Laboratoire de Physicochimie Théorique et Chimie Informatique, Faculté de Chimie, USTHB, El-Alia, Dar El Beida, AlgeriaAbstract: Cardiovascular disease, including atherosclerosis, is the leading cause of death in patients with diabetes worldwide; thus, it is a major medical concern. The endothelium contributes to the control of many vascular functions, and clinical observations show that it is a primary target for diabetic syndrome. To get better insight into the mechanisms underlying atherosclerosis, we studied the interspecific differences in the arterial metabolisms of two, Psammomys obesus and Gerbillus gerbillus, as well as Rattus norvegicus (Wistar rat, well known for its atheroresistance. Twenty-two enzymatic activities and six macromolecular substances were histochemically compared in the two desert species and in Wistar aortas (abdominal and thoracic and arteries (femoral and caudal embedded in a common block. In the healthy adult rodents, enzyme activities were very intense. They demonstrated that aortic myocytes are capable of various synthesis and catabolism processes. However, considering the frequency of atherosclerosis and its phenotypes, significant differences appeared between the species studied. Our comparative study shows that aortic atherosensitive animals have several common metabolic characteristics, which are found in Psammomys rich in metachromatic glycosaminoglycans (involved in the inhibition of lipolysis and in calcification of the organic matrix, reduced activity in enzymes related to the Krebs cycle (weakening energetic power, and low lipolytic enzyme, adenosine triphosphatase, and adenosine diphosphatase activities

  1. High surface area niobium oxides as catalysts for improved hydrogen sorption properties of ball milled MgH2

    International Nuclear Information System (INIS)

    Bhat, V.V.; Rougier, A.; Aymard, L.; Nazri, G.A.; Tarascon, J.-M.

    2008-01-01

    We report, high surface area (up to 200 m 2 /g) nanocrystalline niobium oxide (so called p-Nb 2 O 5 ) synthesized by 'chimie douce' route and its importance in enhancing the hydrogen sorption properties of MgH 2 . p-Nb 2 O 5 induces faster kinetics than commonly used commercial Nb 2 O 5 (c-Nb 2 O 5 ) when ball milled with MgH 2 (named (MgH 2 ) catalyst ) by reducing the time of desorption from 35 min in (MgH 2 ) c-Nb 2 O 5 to 12 min in (MgH 2 ) p-Nb 2 O 5 at 300 deg. C. The BET surface area of as-prepared Nb 2 O 5 was tuned by heat treatment and its effect on sorption properties was studied. Among them, both p-Nb 2 O 5 and Nb 2 O 5 :350 (p-Nb 2 O 5 heated to 350 deg. C with a BET specific surface area of 46 m 2 /g) desorb 5 wt.% within 12 min, exhibiting the best catalytic activity. Furthermore, thanks to the addition of high surface area Nb 2 O 5 , the desorption temperature was successfully lowered down to 200 deg. C, with a significant amount of desorbed hydrogen (4.5 wt.%). In contrast, the composite (MgH 2 ) c-Nb 2 O 5 shows no desorption at this 'low' temperature

  2. Hybrid materials science: a promised land for the integrative design of multifunctional materials.

    Science.gov (United States)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-06-21

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of "hybrid organic-inorganic" nanocomposites exploded in the second half of the 20th century with the expansion of the so-called "chimie douce" which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  3. La théorie quantique en images

    CERN Document Server

    McEvoy, J P

    2014-01-01

    La théorie quantique nous confronte avec les paradoxes bizarres qui contredisent les fondements de la physique classique. Au niveau subatomique, une particule semble savoir ce que font les autres, mais selon « le principe d'incertitude » de Heisenberg, il y a une limite sur la précision des observations. Pourtant, la théorie quantique est étonnamment précise et largement appliquée en chimie et en physique. Cet ouvrage nous emmène dans un voyage où vous rencontrerez Planck, Einstein, Bohr, Heisenberg et Schrödinger, chacun d'entre eux ayant contribué aux concepts de cette théorie révolutionnaire. La dualité onde-particule, l'interprétation de Copenhague, le chat de Schrödinger, le paradoxe EPR etc... sont autant d'expériences et de concepts qui sont décrits dans cet ouvrage.

  4. Histoire d'une cité scientifique le campus du CNRS à Gif-sur-Yvette (1946-2016)

    CERN Document Server

    2016-01-01

    L'histoire du campus de Gif-sur-Yvette, cité scientifique de renommée internationale, commence en 1946, à l'heure de la reconstruction de la recherche française, ajuste après le deuxième conflit mondial. L'histoire du campus de Gif-sur-Yvette, cité scientifique de renommée internationale, commence en 1946, à l'heure de la reconstruction de la recherche française, ajuste après le deuxième conflit mondial. À cette époque, l'on cherche à favoriser l'émergence d'études nouvelles, à soutenir les travaux fondamentaux sans s'interdire de réfléchir à leurs applications, ou encore à stimuler l'interdisciplinarité. L'acquisition du domaine par le CNRS reflète alors l'ambition de son directeur, Frédéric Joliot-Curie, de refonder la Recherche scientifique et de restaurer son rayonnement. Depuis, le campus de Gif-sur-Yvette a connu une formidable aventure, aussi bien humaine que scientifique. Pionnier dans de nombreux domaines, en biologie, en chimie mais aussi en sciences du climat et de l'env...

  5. Recent advances in membrane materials: introductory remarks

    International Nuclear Information System (INIS)

    Ayral, A.

    2007-01-01

    A lot of separation operations are currently performed using membranes both for production processes and for environmental applications. The main part of the used membranes are organic membranes but for specific conditions of utilization inorganic or organic-inorganic membranes have been also developed. Among the applications for gas separation, some examples are the removal of hydrogen from ammonia synthesis gas, the removal of carbon dioxide from natural gas and air separation. Environmental considerations like massive scale air and water pollution and also the gradual rarefaction of fossil energy resources gave rise to the concept of sustainable growth and to related strategies like process intensification, the reuse of water and solvents at their point of use, hydrogen as energy vector (requiring H 2 production...)..Membranes will have a key part to play in the new technologies associated with these strategies. Intensive efforts of research and development are now engaged everywhere in the world to develop high performance membranes for those emerging applications. Membrane science is a multidisciplinary scientific and technological domain covering mainly materials science, physical chemistry, chemical engineering, modeling. This issue (Annales de chimie - Science des materiaux, 2007 Vol.32 N.2) provides a wide review of recent advances in membrane materials. It is based on the contributions of experts in different fields of membrane materials (organic, organic-inorganic hybrid, composite, carbon, metallic, ceramic; dense, porous, surface modified materials). (O.M.)

  6. Validation of nine years of MOPITT V5 NIR using MOZAIC/IAGOS measurements: biases and long-term stability

    Directory of Open Access Journals (Sweden)

    A. T. J. de Laat

    2014-11-01

    Full Text Available Validation results from a comparison between Measurement Of Pollution In The Troposphere (MOPITT V5 Near InfraRed (NIR carbon monoxide (CO total column measurements and Measurement of Ozone and Water Vapour on Airbus in-service Aircraft (MOZAIC/In-Service Aircraft for a Global Observing System (IAGOS aircraft measurements are presented. A good agreement is found between MOPITT and MOZAIC/IAGOS measurements, consistent with results from earlier studies using different validation data and despite large variability in MOPITT CO total columns along the spatial footprint of the MOZAIC/IAGOS measurements. Validation results improve when taking the large spatial footprint of the MOZAIC/IAGOS data into account. No statistically significant drift was detected in the validation results over the period 2002–2010 at global, continental and local (airport scales. Furthermore, for those situations where MOZAIC/IAGOS measurements differed from the MOPITT a priori, the MOPITT measurements clearly outperformed the MOPITT a priori data, indicating that MOPITT NIR retrievals add value to the MOPITT a priori. Results from a high spatial resolution simulation of the chemistry-transport model MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle showed that the most likely explanation for the large MOPITT variability along the MOZAIC-IAGOS profile flight path is related to spatio-temporal CO variability, which should be kept in mind when using MOZAIC/IAGOS profile measurements for validating satellite nadir observations.

  7. Hybrid materials science: a promised land for the integrative design of multifunctional materials

    Science.gov (United States)

    Nicole, Lionel; Laberty-Robert, Christel; Rozes, Laurence; Sanchez, Clément

    2014-05-01

    For more than 5000 years, organic-inorganic composite materials created by men via skill and serendipity have been part of human culture and customs. The concept of ``hybrid organic-inorganic'' nanocomposites exploded in the second half of the 20th century with the expansion of the so-called ``chimie douce'' which led to many collaborations between a large set of chemists, physicists and biologists. Consequently, the scientific melting pot of these very different scientific communities created a new pluridisciplinary school of thought. Today, the tremendous effort of basic research performed in the last twenty years allows tailor-made multifunctional hybrid materials with perfect control over composition, structure and shape. Some of these hybrid materials have already entered the industrial market. Many tailor-made multiscale hybrids are increasingly impacting numerous fields of applications: optics, catalysis, energy, environment, nanomedicine, etc. In the present feature article, we emphasize several fundamental and applied aspects of the hybrid materials field: bioreplication, mesostructured thin films, Lego-like chemistry designed hybrid nanocomposites, and advanced hybrid materials for energy. Finally, a few commercial applications of hybrid materials will be presented.

  8. Physical chemistry and modelling of the sintering of actinide oxides

    International Nuclear Information System (INIS)

    Lechelle, Jacques

    2013-01-01

    This report gives a synthesis of the work I have carried out or to which I have numerically contributed to from 1996 up to 2012 in the Department of Plutonium Uranium and minor Actinides in Cadarache CEA Center. Their main goal is the study and the modeling of the sintering process of nuclear fuels which is the unifying thread of this document. Both in order to take into account the physical and chemical features of the actinide bearing oxide material and in order to combine the different transport phenomena leading to sintering, a sub-granular scale model is under development. Extension to a varying chemical composition as well as exchanges with the gaseous phase are foreseen. A simulation on a larger scale (pellet scale) is ongoing in the framework of a PhD thesis. Validation means have been tested with (U,Pu)O 2 material on the scale of the pellet (Small Angle Neutron Diffusion), on the scale of powder granules (X-Ray High Resolution Micro-Tomography) and with CeO 2 at the 'Institut de Chimie Separative' in Marcoule on a single crystal scale (Environmental Scanning Electron Microscope). The required microstructure homogeneity for nuclear fuels has led to a campaign of experimental studies about the role of Cr 2 O 3 as a sintering aid. Whole of these studies improve our understanding of fuel sintering and hence leads to an improved mastering of this process. (author) [fr

  9. En route vers la nano stabilisation de CLIC faisceau principale et focalisation finale

    CERN Document Server

    Artoos, K; Guinchard, M; Hauviller, Claude; Lackner, F; CERN. Geneva. TS Department

    2008-01-01

    Pour atteindre la luminosité voulue de CLIC, la taille transversale du faisceau doit être de l?ordre du nanomètre. Ceci nécessite une stabilité vibratoire des quadripôles du faisceau principal de 1 nm et même 0.1 nm pour les doublets de la focalisation finale. La nano technologie et la nano stabilisation sont des activités qui évoluent rapidement dans l?industrie et centres de recherche pour des applications très variées comme l?électronique, l?optique, la chimie voire la médecine. Cette présentation décrit les avancées techniques nécessaires pour atteindre l?objectif de CLIC et les projets et collaborations R&D prévus pour démontrer la faisabilité de la nano stabilisation de CLIC en 2010.

  10. Production ultra propre

    CERN Document Server

    Morvan, Gilles

    2011-01-01

    L'ultra propreté se caractérise par l'absence de particules et la maîtrise de la contamination dans un environnement défini. Largement appliquée dans diverses industries (pharmacie, cosmétiques, dispositifs médicaux, chimie fine, biotechnologies, électronique et secteurs de pointe, agroalimentaire, plasturgie…), la technicité dans ce domaine est élevée, car principalement liée à la maîtrise des différentes sources de contaminations (eau, air ambiant, fluides, etc.). Véritable guide pratique, cet ouvrage détaille les points techniques essentiels pour permettre à l’ingénieur de trouver des solutions adéquates à chaque type de projet. La démarche passe par la rédaction de spécifications rigoureuses pour : - l’eau, essentielle à toutes productions, - les équipements de production ultra propre, - la démarche qualité et environnementale, - la démarche de suivi du projet.

  11. Radiolabeling of biological vectors by poly-aza-macrocyclic complexes

    International Nuclear Information System (INIS)

    Moreau, M.

    2012-01-01

    This work conducted at the 'Institut de Chimie Moleculaire de l'Universite de Bourgogne' carries at first on the synthesis of bifunctional chelating agents suitable for the chelation of trivalent radio-metals, including indium-111. The greater part of this work was then dedicated to the grafting of a DOTA derivative bifunctional chelating agent on different antibodies or fragments of monoclonal antibodies: trastuzumab (anti-HER2 treatment of breast cancer), cetuximab (anti EGFR, treatment of many cancers, including colorectal cancer) and abciximab (antiplatelet). Particular attention was paid to the characterization of various immuno-conjugates. The critical step of this thesis consisted in the indium-111 radiolabeling of two previously prepared immuno-conjugates: trastuzumab and cetuximab. These steps of radiolabelling allowed us to determine the immunoreactive fraction and affinity of each radiotracer. Thus, we were able to study the in vivo biodistribution of the radiotracers in tumour-bearing mice by SPECT-CT. We also developed an original method for the labeling of a Fab antibody fragment in order to monitor the biodistribution of the antiplatelet agent (abciximab). Finally, we also validated the concept of multimodal imaging through grafting and radiolabeling of a bimodal agent for optical and SPECT imaging on bacterial lipopolysaccharide. Thanks to this work, we gained an expertise in antibodies radiolabeling. The results obtained allow to consider the labeling of antibodies or other biomolecules, and the use of other radionuclides for PET imaging and radioimmunotherapy. (author)

  12. Dosimetry techniques of thermal neutrons and {gamma} radiation in reactor cores; Techniques de dosimetrie des neutrons thermiques et du rayonnement {gamma} dans les piles

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, J; Draganic, I; Hering, H [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    Chemical studies under radiation done in the reactor cores require to be followed by dosimetry. When the irradiations are done in the reflector, one can limit to the measure of the {gamma} and the neutron radiation. For the dosimetry of the {gamma} radiation, a dosimeter of ferrous sulfate is convenient until doses of about 10{sup 6} rep. The use of aired oxalic acid solutions permits to reach 10{sup 7} rep. The dosimetry of thermal neutrons has been made with solutions of cobalt sulphate or paper filter impregnated with this salt. The total chemical effect of the {gamma} and of the slow neutrons radiation is obtained with solutions of ferrous sulfate added with lithium sulphate. (M.B.) [French] Les etudes de chimie sous radiation faites dans les piles exigent d'etre suivies par dosimetrie. Lorsque les irradiations sont effectues dans le reflecteur, on peut se limiter a doser le rayonnement {gamma} et les neutrons. Pour la dosimetrie du rayonnement {gamma}, un dosimetre a sulfate ferreux convient jusqu'a des doses d'environ 10{sup 6} rep. L'emploi de solutions aerees d'acide oxalique permet d'atteindre 10{sup 7} rep. La dosimetrie des neutrons thermiques a ete faite avec des solutions de sulfate de cotalt ou du papier filtre impregne de ce sel. L'effet chimique total du rayonnement {gamma} et des neutrons lents est obtenu avec des solutions de sulfate ferreux additionne de sulfate de lithium. (M.B.)

  13. Real-time in-situ monitoring of the topotactic transformation of TlCu3Se2 into TlCu2Se2

    International Nuclear Information System (INIS)

    Ångström, J.; Sahlberg, M.; Berger, R.

    2015-01-01

    Highlights: • Topotactic transition from TlCu 3 Se 2 to TlCu 2 Se 2 followed in situ. • Synchrotron radiation X-ray powder diffraction enabled short scans. • Relative abundance of phases refined from powder data. • Opens up for studying similar systems in the same manner. - Abstract: The solid state transformation of monoclinic TlCu 3 Se 2 into tetragonal TlCu 2 Se 2 by oxidative copper leaching in concentrated ammonia solution has been studied in situ by the use of synchrotron radiation. The diffraction patterns of parent and daughter phase are both sharp, indicating a strong topotactic relationship between them that effectuates a rapid change by “chimie douce” performed at +19 °C. The transformation rate is strongly connected to the access of oxygen from the surrounding air. The transformation was followed in a real-time mode, being almost complete after 2.5 h with 1 h incubation due to low oxygen content, as shown from refining the diffraction patterns by Rietveld profile technique

  14. Real-time in-situ monitoring of the topotactic transformation of TlCu{sub 3}Se{sub 2} into TlCu{sub 2}Se{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Ångström, J.; Sahlberg, M.; Berger, R.

    2015-07-15

    Highlights: • Topotactic transition from TlCu{sub 3}Se{sub 2} to TlCu{sub 2}Se{sub 2} followed in situ. • Synchrotron radiation X-ray powder diffraction enabled short scans. • Relative abundance of phases refined from powder data. • Opens up for studying similar systems in the same manner. - Abstract: The solid state transformation of monoclinic TlCu{sub 3}Se{sub 2} into tetragonal TlCu{sub 2}Se{sub 2} by oxidative copper leaching in concentrated ammonia solution has been studied in situ by the use of synchrotron radiation. The diffraction patterns of parent and daughter phase are both sharp, indicating a strong topotactic relationship between them that effectuates a rapid change by “chimie douce” performed at +19 °C. The transformation rate is strongly connected to the access of oxygen from the surrounding air. The transformation was followed in a real-time mode, being almost complete after 2.5 h with 1 h incubation due to low oxygen content, as shown from refining the diffraction patterns by Rietveld profile technique.

  15. [6-chloro-3-pyridylmethyl-{sup 3}H]neonicotinoids as high-affinity radioligands for the nicotinic acetylcholine receptor: preparation using NaB{sup 3}H{sub 4} and LiB{sup 3}H{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Latli, Bachir; Casida, J.E. [California Univ., Berkeley, CA (United States). Dept. of Environmental Science Policy and Management; Chit Than; Morimoto, Hiromi; Williams, P.G. [Lawrence Berkeley National Lab., CA (United States)

    1996-11-01

    NaB{sup 3}H{sub 4} and LiB{sup 3}H{sub 4} at 78% and 97% isotopic enrichments, respectively, were used in the synthesis of {sup 3}H-labeled 1-(6-chloro-3-pyridyl)-methyl-2-nitromethyleneimidazolidine (CH-IMI) and N`-[(6-chloro-3-pyridyl)methyl]-n``-cyano-n`-methylacetamidine (acetamiprid) (two very potent insecticides) and of 1-(6-chloro-3-pyridyl)methyl-2-iminoimidazolidine (desnitro-IMI) (a metabolite of the commercial insecticides imidacloprid). 6-Chloronicotinoyl chloride was treated with either NaB{sup 3}H{sub 4} in methanol or LiB{sup 3}H{sub 4} in tetrahydrofuran and the resulting alcohol transformed to 2-chloro-5-chloromethylpyridine, which was then coupled to N-cyano-N`-methylacetamidine to give [{sup 3}H] acetamiprid (45 Ci/mmol). 2-Chloro-5-chloro[{sup 3}H]methylpyridine was also reacted with ethylenediamine and the product was either refluxed in absolute ethanol with 1,1-bis(methylthio)-2-nitro-ethylene to provide [{sup 3}H]CH-IMI or reacted in toluene with a solution of cyanogen bromide to produce [{sup 3}H] desnitro-IMI (each 55 Ci/mmol). (author).

  16. [6-chloro-3-pyridylmethyl-3H]neonicotinoids as high-affinity radioligands for the nicotinic acetylcholine receptor: preparation using NaB3H4 and LiB3H4

    International Nuclear Information System (INIS)

    Latli, Bachir; Casida, J.E.

    1996-01-01

    NaB 3 H 4 and LiB 3 H 4 at 78% and 97% isotopic enrichments, respectively, were used in the synthesis of 3 H-labeled 1-(6-chloro-3-pyridyl)-methyl-2-nitromethyleneimidazolidine (CH-IMI) and N'-[(6-chloro-3-pyridyl)methyl]-n''-cyano-n'-methylacetamidine (acetamiprid) (two very potent insecticides) and of 1-(6-chloro-3-pyridyl)methyl-2-iminoimidazolidine (desnitro-IMI) (a metabolite of the commercial insecticides imidacloprid). 6-Chloronicotinoyl chloride was treated with either NaB 3 H 4 in methanol or LiB 3 H 4 in tetrahydrofuran and the resulting alcohol transformed to 2-chloro-5-chloromethylpyridine, which was then coupled to N-cyano-N'-methylacetamidine to give [ 3 H] acetamiprid (45 Ci/mmol). 2-Chloro-5-chloro[ 3 H]methylpyridine was also reacted with ethylenediamine and the product was either refluxed in absolute ethanol with 1,1-bis(methylthio)-2-nitro-ethylene to provide [ 3 H]CH-IMI or reacted in toluene with a solution of cyanogen bromide to produce [ 3 H] desnitro-IMI (each 55 Ci/mmol. (author)

  17. Measurement of radioactive aerosols as an original indicator of atmospheric pollution in urban areas

    International Nuclear Information System (INIS)

    Le Petit, G.; Millies-Lacroix, J. C.

    1998-01-01

    The Service Radioanalyses, Chimie et Environnment (Departement Analyses Surveillance de l'Environnement) of the French Atomic Energy Commission, located in suburban Paris, has for many years been conducting atmospheric radioactivity measurements. Since 1994, the laboratory has been using high volume air samplers equipped with filters for the weekly collection of atmospheric aerosols at a mean rate of about 600 m 3 .h -1 . The polypropylene filters, with a collection efficiency in excess of 93%, are compacted after sampling. The atmospheric radioactivity is measured by HP Ge gamma spectrometry after decay of short-lived natural relationship products. A study conducted in 1996 shows good correlation between the evolution with time of some of the indicators routinely used by AIRPARIF, the organization in charge of monitoring the air quality in the Ile-de-France region, to measure atmospheric pollution in the Paris area (SO 2 , NO) and that related to radioactivity of terrestrial ( 210 Pb, 40 K) and anthropogenic ( 137 Cs) origin, as well as the amount of aerosols collected. Further, the distribution in time of the atmospheric radioactivity of cosmogenic origin ( 7 Be) shows a yearly evolution somewhat similar to that observed with ozone

  18. Qualité chimique et biologique du bassin de la Semois (partie Belge

    Directory of Open Access Journals (Sweden)

    LECLERCQ L.

    1996-04-01

    Full Text Available Les eaux du bassin de la Semois belge ont été étudiées, en 25 stations, sous différents aspects complémentaires : chimie, diatomées et invertébrés benthiques. Les méthodes utilisées sont l'indice de pollution organique (IPO, LECLERCQ et VANDEVENNE, 1987, un indice diatomique (ID, LECLERCQ, non publié et l'indice biologique global normalisé (IBGN, AFNOR, 1992. Grâce aux analyses chimiques et diatomiques, nous décrivons différents types d'eaux naturelles, à minéralisation croissante, et différents niveaux de pollution et d'eutrophication. Nous présentons une carte d e qualité détaillée, à l'usage des gestionnaires. Les diatomées apparaissent comme les bioindicateurs les plus fiables pour ces paramètres. Les invertébrés sont moins intéressants à utiliser. Ils sont pratiquement insensibles au type de minéralisation de l'eau (tout au moins au niveau de la famille, qui est le seul niveau d'identification possible en routine, mais ces organismes peuvent être plus sensibles au facteur substrat qu'à la pollution organique, conduisant alors à des estimations erronées.

  19. Bridging gaps in discovery and development: chemical and biological sciences for affordable health, wellness and sustainability.

    Science.gov (United States)

    Chauhan, Prem Man Singh

    2011-05-01

    To commemorate 2011 as the International Year of Chemistry, the Indian Society of Chemists and Biologists organized its 15th International Conference on 'Bridging Gaps in Discovery and Development: Chemical and Biological Sciences for Affordable Health, Wellness and Sustainability' at Hotel Grand Bhagwati, in association with Saurashtra University, Rajkot, India. Anamik Shah, President of the Indian Society of Chemists and Biologists, was organizing secretary of the conference. Nicole Moreau, President of the International Union of Pure and Applied Chemistry and Secretary General of the Comité National de la Chimie, National Centre for Scientific Research France, was chief guest of the function. The four-day scientific program included 52 plenary lectures, 24 invited lectures by eminent scientists in the field and 12 oral presentations. A total of 317 posters were presented by young scientists and PhD students in three different poster sessions. Approximately 750 delegates from India, the USA, UK, France, Switzerland, Germany, Austria, Belgium, Sweden, Japan and other countries attended the conference. The majority of the speakers gave presentations related to their current projects and areas of interest and many of the talks covered synthesis, structure-activity relationships, current trends in medicinal chemistry and drug research.

  20. [The knowledge of animal respiration as a combustion phenomenon].

    Science.gov (United States)

    de Micheli, Alfredo

    2014-01-01

    The different stages leading to knowledge of the phenomenon of animal breathing are going from some writings in Corpus Hippocraticum to Aristoteles' and Galen's works, who considered the heart as the source of the animal heat. Later, Miguel Servet suggested that the inspired air can achieve other functions besides cooling the blood. After that, different explications of the animal heat were raised. About 1770, due to progress of knowledge in the chemistry field, first Mayow and later Black began to consider the animal respiration as a combustion. The important treatise Méthode de nomenclature chimique, published by Guyton de Morveau et al. in 1787 and soon after the Traité élémentaire de chimie de Lavoisier (1789) provided a solid support to Lavoisier's thought. This way on arrived to consider analogous the respiration and combustion phenomena. Studies on the animal respiration phenomenon continued in xix century and in the following century it was possible to apply thermodynamic principles to biology: "generalized thermodynamics". Copyright © 2013 Instituto Nacional de Cardiología Ignacio Chávez. Published by Masson Doyma México S.A. All rights reserved.

  1. High-performing mesoporous iron oxalate anodes for lithium-ion batteries.

    Science.gov (United States)

    Ang, Wei An; Gupta, Nutan; Prasanth, Raghavan; Madhavi, Srinivasan

    2012-12-01

    Mesoporous iron oxalate (FeC(2)O(4)) with two distinct morphologies, i.e., cocoon and rod, has been synthesized via a simple, scalable chimie douce precipitation method. The solvent plays a key role in determining the morphology and microstructure of iron oxalate, which are studied by field-emission scanning electron microscopy and high-resolution transmission electron microscopy. Crystallographic characterization of the materials has been carried out by X-ray diffraction and confirmed phase-pure FeC(2)O(4)·2H(2)O formation. The critical dehydration process of FeC(2)O(4)·2H(2)O resulted in anhydrous FeC(2)O(4), and its thermal properties are studied by thermogravimetric analysis. The electrochemical properties of anhydrous FeC(2)O(4) in Li/FeC(2)O(4) cells are evaluated by cyclic voltammetry, galvanostatic charge-discharge cycling, and electrochemical impedance spectroscopy. The studies showed that the initial discharge capacities of anhydrous FeC(2)O(4) cocoons and rods are 1288 and 1326 mA h g(-1), respectively, at 1C rate. Anhydrous FeC(2)O(4) cocoons exhibited stable capacity even at high C rates (11C). The electrochemical performance of anhydrous FeC(2)O(4) is found to be greatly influenced by the number of accessible reaction sites, morphology, and size effects.

  2. In Situ Tracking Kinetic Pathways of Li+/Na+ Substitution during Ion-Exchange Synthesis of LixNa1.5-xVOPO4F0.5.

    Science.gov (United States)

    Park, Young-Uk; Bai, Jianming; Wang, Liping; Yoon, Gabin; Zhang, Wei; Kim, Hyungsub; Lee, Seongsu; Kim, Sung-Wook; Looney, J Patrick; Kang, Kisuk; Wang, Feng

    2017-09-13

    Ion exchange is a ubiquitous phenomenon central to wide industrial applications, ranging from traditional (bio)chemical separation to the emerging chimie douce synthesis of materials with metastable structure for batteries and other energy applications. The exchange process is complex, involving substitution and transport of different ions under non-equilibrium conditions, and thus difficult to probe, leaving a gap in mechanistic understanding of kinetic exchange pathways toward final products. Herein, we report in situ tracking kinetic pathways of Li + /Na + substitution during solvothermal ion-exchange synthesis of Li x Na 1.5-x VOPO 4 F 0.5 (0 ≤ x ≤ 1.5), a promising multi-Li polyanionic cathode for batteries. The real-time observation, corroborated by first-principles calculations, reveals a selective replacement of Na + by Li + , leading to peculiar Na + /Li + /vacancy orderings in the intermediates. Contradicting the traditional belief of facile topotactic substitution via solid solution reaction, an abrupt two-phase transformation occurs and predominantly governs the kinetics of ion exchange and transport in the 1D polyanionic framework, consequently leading to significant difference of Li stoichiometry and electrochemical properties in the exchanged products. The findings may help to pave the way for rational design of ion exchange synthesis for making new materials.

  3. Stephen Neidle on cancer therapy and G-quadruplex inhibitors. Interview by Joanna De Souza.

    Science.gov (United States)

    Neidle, Stephen

    2004-09-15

    Stephen Neidle was educated at Imperial College, London, where he graduated in chemistry and then proceeded to do a PhD in crystallography. After a period as an ICI Fellow, he joined the Biophysics Department at King's College, which ignited his interest in nucleic acid structural studies. He was appointed as one of the first Cancer Research Campaign Career Development Awardees, becoming a Life Fellow on moving to the Institute of Cancer Research. He was appointed to the Chair of Biophysics at the Institute of Cancer Research in 1990, and moved to the new Chair of Chemical Biology at the School of Pharmacy in the University of London in 2002, where he also directs the Cancer Research UK Biomolecular Structure Group. He is currently Chairman of the Chemical Biology Forum of the Royal Society of Chemistry, which is involved in developing the interface between chemistry and the life sciences. He will shortly assume the Directorship of the newly-established Centre for Cancer Medicines at the School. Stephen Neidle has received several awards for his work on drug-nucleic acid recognition and drug design, including the 2000 prize of the Biological and Medicinal Chemistry Sector of the Royal Society of Chemistry, and its 2002 Interdisciplinary Award. He was the 2004 Paul Ehrlich Lecturer of the French Societé de Chimie Therapeutique, and was recently awarded the 2004 Aventis Prize in Medicinal Chemistry.

  4. A General and Mild Approach to Controllable Preparation of Manganese-Based Micro- and Nanostructured Bars for High Performance Lithium-Ion Batteries.

    Science.gov (United States)

    Ma, Guo; Li, Sheng; Zhang, Weixin; Yang, Zeheng; Liu, Shulin; Fan, Xiaoming; Chen, Fei; Tian, Yuan; Zhang, Weibo; Yang, Shihe; Li, Mei

    2016-03-07

    One-dimensional (1D) micro- and nanostructured electrode materials with controllable phase and composition are appealing materials for use in lithium-ion batteries with high energy and power densities, but they are challenging to prepare. Herein, a novel ethanol-water mediated co-precipitation method by a chimie douce route (synthesis conducted under mild conditions) has been exploited to selectively prepare an extensive series of manganese-based electrode materials, manifesting the considerable generalizability and efficacy of the method. Moreover, by simply tuning the mixed solvent and reagents, transition metal oxide bars with differing aspect ratios and compositions were prepared with an unprecedented uniformity. Application prospects are demonstrated by Li-rich 0.5 Li2 MnO3 ⋅0.5 LiNi1/3 Co1/3 Mn1/3 O2 bars, which demonstrate excellent reversible capacity and rate capability thanks to the steerable nature of the synthesis and material quality. This work opens a new route to 1D micro- and nanostructured materials by customizing the precipitating solvent to orchestrate the crystallization process. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. High mass and spatial resolution mass spectrometry imaging of Nicolas Poussin painting cross section by cluster TOF-SIMS.

    Science.gov (United States)

    Noun, M; Van Elslande, E; Touboul, D; Glanville, H; Bucklow, S; Walter, P; Brunelle, A

    2016-12-01

    The painting Rebecca and Eliezer at the Well, which hangs in the Fitzwilliam Museum, Cambridge, UK, is possibly one of the last figure painting executed by Nicolas Poussin at the very end of his life and is usually dated to the early 1660s. In this perspective special feature, Philippe Walter, Alain Brunelle and colleagues give new insights on the artist's working methods by a careful stateof-the-art imaging ToF-SIMS study of one sample taken on the edge of the painting. This approach allowed for the identification of the pigments used in the painting, their nature and components and those of the ground and preparatory layers, with the identification of the binder(s) and possible other additions of organic materials such as glue. This study paves the way to a wider use of ToF-SIMS for the analysis of ancient cultural heritage artefacts. Dr. Walter is the Director of the Molecular and Structural Archeology Laboratory (Université Pierre et Marie Curie, Paris, France). Dr. Brunelle is Head of the Mass Spectrometry Laboratory at the Institut de Chimie des Substances Naturelles (CNRS, Gif-sur-Yvette, France). Their long standing collaboration has led to several seminal publications on the analysis of ancient artefacts by mass spectrometry. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Living hybrid materials capable of energy conversion and CO2 assimilation.

    Science.gov (United States)

    Meunier, Christophe F; Rooke, Joanna C; Léonard, Alexandre; Xie, Hao; Su, Bao-Lian

    2010-06-14

    This paper reviews our work on the fabrication of photobiochemical hybrid materials via immobilisation of photosynthetically active entities within silica materials, summarising the viability and productivity of these active entities post encapsulation and evaluating their efficiency as the principal component of a photobioreactor. Immobilisation of thylakoids extracted from spinach leaves as well as whole cells such as A. thaliana, Synechococcus and C. caldarium was carried out in situ using sol-gel methods. In particular, a comprehensive overview is given of the efforts to find the most biocompatible inorganic precursors that can extend the lifetime of the organisms upon encapsulation. The effect of matrix-cell interactions on cell lifetime and the photosynthetic efficiency of the resultant materials are discussed. Precursors based on alkoxides, commonly used in "Chimie Douce" to form porous silica gel, release by-products which are often cytotoxic. However by controlling the formation of gels from aqueous silica precursors and silica nanoparticles acting as "cements" one can significantly enhance the life span of the entrapped organelles and cells. Adapted characteristic techniques have shown survival times of up to 5 months with the photosynthetic production of oxygen recorded as much as 17 weeks post immobilisation. These results constitute a significant advance towards the final goal, long-lasting semi-artificial photobioreactors that can advantageously exploit solar radiation to convert polluting carbon dioxide into useful biofuels, sugars or medical metabolites.

  7. [Charles Gerhardt's life and work].

    Science.gov (United States)

    Blondel-Mégrelis, Marika

    2008-05-01

    Charles Gerhardt's life and work is rather well-known thanks to Grimaux and Tiffeneau. His reform of the equivalents, his classification, his obtention of organic acid anhydrids and his famous Treatise of Organic Chemistry. His active collaboration to the Revue scientifique et industrielle du Docteur Quesneville, the creation of his Comptes-Rendus des Travaux de Chimie. Are not so often quoted. Thanks to his translations and reviews, German chemical advancements became well known in France Gerhardt was Liebig's translator for almost all his life, even through the fluctuations of their personal relation. He was the representative of German chemistry in France. With Auguste Laurent, with whom he is constantly associated, things need to be examined precisely. Laurent and Gerhardt, friends at a moment, cannot be confounded. Though they worked together for some years, they were not engaged in a similar project. Besides an experimentalist, Laurent was essentially a theorician of chemistry, whereas Gerhardt refused to think about atoms and arrangements. Formulas have to describe relations between facts, in no case anything about arrangements. For posterity however, Gerhardt will be, on the same level as Laurent, the creator of modern chemistry doctrines.

  8. CaMn(1-x)Nb(x)O3 (x < or = 0.08) perovskite-type phases as promising new high-temperature n-type thermoelectric materials.

    Science.gov (United States)

    Bocher, L; Aguirre, M H; Logvinovich, D; Shkabko, A; Robert, R; Trottmann, M; Weidenkaff, A

    2008-09-15

    Perovskite-type CaMn(1-x)Nb(x)O(3+/-delta) (x = 0.02, 0.05, and 0.08) compounds were synthesized by applying both a "chimie douce" (SC) synthesis and a classical solid state reaction (SSR) method. The crystallographic parameters of the resulting phases were determined from X-ray, electron, and neutron diffraction data. The manganese oxidations states (Mn(4+)/Mn(3+)) were investigated by X-ray photoemission spectroscopy. The orthorhombic CaMn(1-x)Nb(x)O(3+/-delta) (x = 0.02, 0.05, and 0.08) phases were studied in terms of their high-temperature thermoelectric properties (Seebeck coefficient, electrical resistivity, and thermal conductivity). Differences in electrical transport and thermal properties can be correlated with different microstructures obtained by the two synthesis methods. In the high-temperature range, the electron-doped manganate phases exhibit large absolute Seebeck coefficient and low electrical resistivity values, resulting in a high power factor, PF (e.g., for x = 0.05, S(1000K) = -180 microV K(-1), rho(1000K) = 16.8 mohms cm, and PF > 1.90 x 10(-4) W m(-1) K(-2) for 450 K 0.3) make these phases the best perovskitic candidates as n-type polycrystalline thermoelectric materials operating in air at high temperatures.

  9. [An iatrochemist in Lower Canada: François Blanchet and his Research on medicine, or application of chemistry in medicine].

    Science.gov (United States)

    Castonguay, S

    1996-01-01

    Francois Blanchet holds a central place in the history of medicine in Lower Canada (now Quebec): a prime mover in the professionalization of French-Canadian physicians, Blanchet was also one of the first Canadians to have studied outside of Canada. While he was in New York, where he studied medicine at Columbia College, he published a book entitled Recherches sur la medecine ou application de la chimie a la medicine. The historiography of Canadian medicine frequently cites this book and presents it as one of the first Canadian medical publications but has not always explored its scientific content. This article therefore examines the medico-chemical aspects of Blanchet's work. Influenced by the Lavoisian revolution in chemistry, Blanchet elaborated a system where etiology and therapy rested on two new elements of nomenclature put forward by French chemists--oxygen and caloric. After examining Blanchet's iatrochemical system, this article compared Recherches sur la medecine with contemporaneous American and European publications in medicine which were themselves inspired by the pneumatic theory of French chemists.

  10. Synthesis temperature effect on the structural features and optical absorption of Zn(1-x)Co(x)Al2O4 oxides.

    Science.gov (United States)

    Gaudon, M; Apheceixborde, A; Ménétrier, M; Le Nestour, A; Demourgues, A

    2009-10-05

    Zinc/cobalt aluminates with spinel-type structure were prepared by a polymeric route, leading to a pure phase with controlled grain size. The prepared pigments were characterized by powder X-ray diffraction Rietveld analyses in order to determine structural features, scanning electron microscopy for morphological investigation, helium pycnometry and (27)Al MAS NMR in order to highlight the occurrence of defects inside the structure, and UV-visible-near-IR spectroscopy to identify electronic transitions responsible for the compounds' color. The green-blue coloration of these pigments is known to be dependent on the sample thermal history. Here, for the first time, the Zn(1-x)Co(x)Al(2)O(4) color is newly interpreted. The pigment is green once synthesized at low temperature (i.e., with diminution of the pigment grain size); this variation was attributed to the appearance of a new absorption band located at about 500 nm, linked to a complex network feature involving Co ions in octahedral sites as well as oxygen and cationic vacancies. Hence, this work shows the possibility of easily getting a nonstoichiometric network with an abnormal cationic distribution from "chimie douce" processes with moderate synthesis temperature, and so various colorations for the same composition.

  11. BASE COMPOSITION OF THE DEOXYRIBONUCLEIC ACID OF SULFATE-REDUCING BACTERIA.

    Science.gov (United States)

    SIGAL, N; SENEZ, J C; LEGALL, J; SEBALD, M

    1963-06-01

    Sigal, Nicole (Laboratoire de Chimie Bactérienne du CNRS, Marseille, France), Jacques C. Senez, Jean Le Gall, and Madeleine Sebald. Base composition of the deoxyribonucleic acid of sulfate-reducing bacteria. J. Bacteriol. 85:1315-1318. 1963-The deoxyribonucleic acid constitution of several strains of sulfate-reducing bacteria has been analytically determined. The results of these studies show that this group of microorganisms includes at least four subgroups characterized by significantly different values of the adenine plus thymine to guanine plus cytosine ratio. The nonsporulated forms with polar flagellation, containing both cytochrome c(3) and desulfoviridin, are divided into two subgroups. One includes the fresh-water, nonhalophilic strains with base ratio from 0.54 to 0.59, and the other includes the halophilic or halotolerant strains with base ratio from 0.74 to 0.77. The sporulated, peritrichous strains without cytochrome and desulfoviridin ("nigrificans" and "orientis") are distinct from the above two types and differ from each other, having base ratios of 1.20 and 1.43, respectively.

  12. Evaluation of the MOCAGE Chemistry Transport Model during the ICARTT/ITOP Experiment

    Science.gov (United States)

    Bousserez, N.; Attie, J. L.; Peuch, V. H.; Michou, M.; Pfister, G.; Edwards, D.; Emmons, L.; Arnold, S.; Heckel, A.; Richter, A.; hide

    2007-01-01

    We evaluate the Meteo-France global chemistry transport 3D model MOCAGE (MOdele de Chimie Atmospherique a Grande Echelle) using the important set of aircraft measurements collected during the ICARRT/ITOP experiment. This experiment took place between US and Europe during summer 2004 (July 15-August 15). Four aircraft were involved in this experiment providing a wealth of chemical data in a large area including the North East of US and western Europe. The model outputs are compared to the following species of which concentration is measured by the aircraft: OH, H2O2, CO, NO, NO2, PAN, HNO3, isoprene, ethane, HCHO and O3. Moreover, to complete this evaluation at larger scale, we used also satellite data such as SCIAMACHY NO2 and MOPITT CO. Interestingly, the comprehensive dataset allowed us to evaluate separately the model representation of emissions, transport and chemical processes. Using a daily emission source of biomass burning, we obtain a very good agreement for CO while the evaluation of NO2 points out incertainties resulting from inaccurate ratio of emission factors of NOx/CO. Moreover, the chemical behavior of O3 is satisfactory as discussed in the paper.

  13. A dynamic dilution system-based evaluation of the procedure adopted for determining ozone precursor volatile compounds.

    Science.gov (United States)

    Palluau, Fabienne; Mirabel, Philippe; Millet, Maurice

    2005-02-01

    A dynamic dilution system was created to evaluate the performance and the reliability of ozone precursor volatile organic compound (VOC) sampling ("TO-Can" canisters) and analysis (thermal desorption/gas chromatography/flame ionisation detection) techniques used by the "Laboratoire Interregional de Chimie du Grand Est (LIC)". Different atmospheres of VOCs were generated at concentrations between 0.8 and 25 ppb, with temperatures of 0, 10, 20 and 30 degrees C, and with relative humidities of 0, 30, 50, 70 and 90%. These conditions are generally representative of those commonly observed in ambient air in the eastern France. This dynamic dilution allows the simulation of a wide range of scenarios (concentrations, temperatures and relative humidities). After assessing the capacity and performance of the system, it was applied in order to evaluate the recoveries and stabilities of VOCs from canisters used for the collection and analysis of two mixtures of VOCs. The first mixture contained six alkanes (ethane, propane, butane, pentane, hexane and heptane), and the second contained five alkenes (ethene, propene, butene, 1-pentene and 1-hexene), five aromatics (benzene, toluene, ethylbenzene, m-xylene and o-xylene), acetylene, and 1,3-butadiene. No significant losses of alkanes from the canisters were observed after 21 days of storage, and good recoveries of alkanes from the canisters (>80%) were obtained regardless of the concentration, the temperature and the relative humidity. However, losses of certain aromatics were noted at low relative humidity.

  14. Utilisation du phytoplancton pour estimer la production piscicole potentielle des étangs

    Directory of Open Access Journals (Sweden)

    BARBE J.

    1999-07-01

    Full Text Available Pour faciliter la gestion des étangs de pisciculture, il est nécessaire d'avoir un moyen pour estimer en cours de saison si l'objectif de production sera atteint, et éventuellement, intervenir sur la qualité du milieu. Les méthodes d'estimation et de prévision mentionnées dans la littérature ne sont pas applicables aux étangs de pisciculture, milieux fortement anthropisés. A partir de données (physico-chimie, plancton, production piscicole collectées sur 36 étangs en France, les auteurs proposent une méthode de prévision de la récolte piscicole à partir du phytoplancton (groupe prédominant et teneur en chlorophylle a. A l'usage, cette méthode s'est avérée satisfaisante pour prévoir des productions nettes jusqu'à plus de 500 kg/hectare.

  15. Modèles et méthodes stochastiques une introduction avec applications

    CERN Document Server

    Del Moral, Pierre

    2014-01-01

    La théorie des probabilités et des processus stochastiques est sans aucun doute l'un des plus importants outils mathématiques des sciences modernes. Le théorie des probabilité s'illustre dans de nombreux domaines issus de la biologie, de la physique, et des sciences de l'ingénieur : dynamique des populations, traitement du signal et de l'image, chimie moléculaire, économétrie, sciences actuarielles, mathématiques financières, ainsi qu'en analyse de risque. Le but de cet ouvrage est de parcourir les principaux modèles et méthodes stochastiques de cette théorie en pleine expansion. Ce voyage ne nécessite aucun bagage spécifique sur la théorie des processus stochastiques. Les outils d'analyses nécessaires à une bonne compréhension sont donnés au fur et à mesure de leur construction, révélant ainsi leur nécessité. La théorie des processus stochastiques est une extension naturelle de la théorie de systèmes dynamiques à des phénomènes aléatoires. Elle contient des formalisation d'é...

  16. Les mathématiques de la physique quantique

    CERN Document Server

    Basdevant, Jean-Louis

    2009-01-01

    Ce manuel contient les techniques mathématiques indispensables au maniement de la mécanique quantique : son apprentissage aussi bien que sa pratique. Composé de cinq chapitres, il couvre le programme suivant : les probabilités, la théorie des distributions, l'analyse de Fourier, l'analyse hilbertienne et quelques exemples utiles de fonctions spéciales. Le niveau est celui de la licence et du mastère de physique, le langage, celui des étudiants de physique et chimie d'aujourd'hui. Le but de l'auteur est la clarté et l'efficacité. Il présente les concepts et les résultats dans une langue aussi simple et aussi juste que possible au plan mathématique tout en restant digeste pour les applications. A l'appui de cas concrets, il souligne les points de rigueur mathématique qui ne sont traités que dans les ouvrages spécialisés. Outre sa dimension modeste, ce petit livre présente plusieurs avantages car, récent, simple et concis, il contient aussi quelques exercices.

  17. Piloter la sécurité théorie et pratiques sur les compromis et les arbitrages nécessaires

    CERN Document Server

    Amalberti, René

    2013-01-01

    Cet ouvrage fait suite à La Conduite des systèmes à risques publié par l’auteur en 1996 (réédition 2001). Le premier livre mettait l’accent sur la sécurité au niveau des individus, celui-ci met l’accent sur la gouvernance de la sécurité dans les industries et services. La sécurité des systèmes complexes n’a pas perdu son actualité, bien au contraire ; citons la vingtaine de catastrophes aériennes annuelles, les presque aussi fréquentes catastrophes de la chimie, le spectre des accidents nucléaires, sans oublier les problèmes atteignant les services publics en médecine ou dans la finance. La liste serait trop longue pour prétendre être exhaustif. Plus que les morts, c’est la diversité des milieux concernés qui frappe l’imagination, et la gravité croissante des sinistres, avec leurs immenses répercussions économiques. On voit là réunies toutes les racines d’un système en équilibre précaire à l’échelle planétaire : produire toujours plus, avec des outils plus com...

  18. Enfants, chercheurs et citoyens

    CERN Document Server

    Lederman, Leon

    1998-01-01

    J'ai consacré ma vie à la physique. J'aimerais que tous les enfants aient la chance de satisfaire leur goût pour la recherche et de développer leur intelligence. J'ai découvert à Chicago, chez mon ami Leon Lederman, une méthode d'enseignement des sciences à l'école qui m'a subjugué. J'ai vu, à tous les niveaux, en physique, en chimie, en sciences naturelles et en mathématiques, des enfants qui expérimentaient avec joie, apprenaient les concepts fondamentaux à leur rythme, réfléchissant et discutant. Je voyais en gestation des êtres libres, capables de rechercher une vérité qui ne leur était pas assenée. J'ai voulu confronter des enseignants français du primaire et du secondaire à ces recherches qui ne se limitent pas à l'enseignement primaire. C'est leur regard critique et surtout leurs idées pour notre enseignement que j'ai rassemblés dans ce livre.

  19. Automatic measuring device for atomic oxygen concentrations (1962); Dispositif de mesure automatique de concentrations d'oxygene atomique (1962)

    Energy Technology Data Exchange (ETDEWEB)

    Weill, J; Deiss, M; Mercier, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-07-01

    Within the framework of the activities of the Autonomous Reactor Electronics Section we have developed a device, which renders automatic one type of measurement carried out in the Physical Chemistry Department at the Saclay Research Centre. We define here: - the physico-chemical principle of the apparatus which is adapted to the measurement of atomic oxygen concentrations; - the physical principle of the automatic measurement; - the properties, performance, constitution, use and maintenance of the automatic measurement device. It is concluded that the principle of the automatic device, whose tests have confirmed the estimation of the theoretical performance, could usefully be adapted to other types of measurement. (authors) [French] Dans le cadre des activites de la Section Autonome d'Electronique des Reacteurs, il a ete realise et mis au point un dispositif permettant de rendre automatique un type de mesures effectuees au Departement de Physico-Chimie du C.E.N. SACLAY. On definit ici: - le principe physico-chimique de l'appareillage, adapte a la mesure de concentrations de l'oxygene atomique; - le principe physique de la mesure automatique; - les qualites, performances, constitution, utilisation, et maintenance du dispositif de mesure automatique. Il est porte en conclusion, que le principe du dispositif automatique realise, dont les essais ont sensiblement confirme l'evaluation des performances theoriques, pourrait etre utilement adapte a d'autres types de mesures courantes. (auteurs)

  20. Picosecond pulse radiolysis study of primary reactions in solutions

    International Nuclear Information System (INIS)

    El-Omar, Abdel Karim

    2013-01-01

    Following the discovery of ionizing radiations and their chemical effects, it was important to study and comprehend the formation mechanisms of short lived free radicals and molecular products. In order to perform such studies, researchers and research groups worked on developing tools allowing both formation and detection of those species at short time scales. Nowadays, pulse radiolysis imposed itself as a fundamental and efficient tool allowing scientists to probe chemical effects as well as reaction mechanisms in studied media. The Laboratoire de Chimie Physique d'Orsay 'LCP' is an interdisciplinary laboratory hosting the platform of fast kinetics known as 'ELYSE'. Due to its femtosecond laser and its picosecond electron accelerator, we have the possibility to study chemical effects of ionizing radiations interaction with media at ultrashort times up to ∼5 ps.Knowing that we are interested in primary reactions induced in aqueous media by ionizing radiations, ELYSE represents the essential tool in performing our studies. The obtained results concern:- First direct determination of hydroxyl radical 'HO*' radiolytic yield as function of time at picosecond time scale;- Direct effect of ionizing radiation in highly concentrated aqueous solutions as well as investigation of the ultrafast electron transfer reaction between solute molecules and positive holes 'H 2 O*+' formed upon water radiolysis;- Study at room temperature of electron transfer reaction between solvated electron (electron donor) and organic solutes (electron acceptors) en viscous medium;- Study at room temperature of electron's solvation dynamics in ethylene glycol and 2-propanol. (author)

  1. Outreach in southern France

    International Nuclear Information System (INIS)

    Jackson, D.

    1992-01-01

    France's Europort South community lives cheek by jowl with the chemical industry, with major complexes at For, Berre, and Lavera. Xavier Segond, technical adviser at the regional chemical industry association, Le Syndicat General des Industries Chimiques Provence-Alpes-Cote d'Azur Corse (SGIC), says a good relationship has grown over a period of 20 years. Segond describes Arco Chimie as an effective driving force for the Responsible Care effort in the region - partly because its US parent introduced the program on a worldwide basis in 1989, ahead of national industry association Union des Industries Chimiques (UIC; Paris). Arco's F2-billion ($373 million)/year Fos-sur-Mer site makes it a significant player. But in 1986 the company was a complete newcomer. We came to Fos as a US company, we had no Paris headquarters or French president, explains Dominique Lequeux, director/human resources. The community viewed the company with a mixture of curiosity and enthusiasm as a potential employer - about 330 people now work at the site. The day before the officials propylene oxide plant opening, we invited in local people, says Lequeux. That formed a good basis for its Responsible Care community outreach program. Now, schools, professional groups, and political groups make 20-25 plant visits each year

  2. GEO-TEP. Development of thermoelectric materials for geothermal energy conversion systems. Final report 2008

    Energy Technology Data Exchange (ETDEWEB)

    Bocher, L.; Weidenkaff, A.

    2008-07-01

    Geothermal heat can be directly converted into electricity by using thermoelectric converters. Thermoelectric conversion relies on intrinsic materials properties which have to be optimised. In this work novel environmentally friendly and stable oxide ceramics were developed to fulfil this task. Thus, manganate phases were studied regarding their potential thermoelectric properties for converting geothermal heat into electricity. Perovskite-type phases were synthesized by applying different methods: the ceramic route, and innovative synthesis routes such as the 'chimie douce' method by bulk thermal decomposition of the citrate precursor or using an USC process, and also the polyol-mediated synthesis route. The crystal structures of the manganate phases are evaluated by XRPD, NPD, and ED techniques while specific microstructures such as twinned domains are highlighted by HRTEM imaging. Besides, the thermal stability of the Mn-oxide phases in air atmosphere are controlled over a wide temperature range (T < 1300 K). The thermoelectric figure of merit ZT was enhanced from 0.021 to 0.3 in a broad temperature range for the studied phases which makes these phases the best perovskitic candidates as n-type polycrystalline thermoelectric materials operating in air at high temperatures. (author)

  3. Intrinsic Evaluation of n/γ Discrimination in Organic Plastic Scintillators

    International Nuclear Information System (INIS)

    Blanc, Pauline; Hamel, Matthieu; Rocha, Licinio; Normand, Stephane; Pansu, Robert; Gobert, Fabrice; Lampre, Isabelle

    2013-06-01

    This paper is devoted to characterizing plastic scintillators with neutron/gamma (n/γ) discrimination abilities and understanding experimentally the photophysical processes downstream. This experimental work is divided into two main studies, neutron sources irradiations and optical photoionization on a range of organic scintillators. The commercial liquid and plastic scintillators, respectively BC-501A from Bicron and EJ-200 from Eljen, are used as references in term of respectively extremely high [1] and poor n/γ discrimination efficiency, or more precisely Triplet-Triplet Annihilation rate probabilities after nuclear irradiations. We have characterized a range of organic plastic scintillators including one developed in our laboratory that shows good discrimination efficiency when compared to plastics that discriminate from literature. For that purpose we use the well known charge comparison as a pulse shape discrimination (PSD) method. We have also studied raw wave forms acquired after neutron irradiation before any kind of treatment was applied and managed to separate two light components, prompt and delayed, thus two particle families. We have demonstrated that by exciting with a 70 femto-seconds pulsed Laser at the femtosecond up to 50 μJ at 260 nm, photoionization was achieved for a range of organic scintillators by observing a delayed light emission in the time decay fluorescence when the Laser energy deposited in the materials was increased. This work is ongoing at CEA in collaboration with the nuclear measurement industry Canberra and the Laboratoire de Chimie Physique from Orsay University. (authors)

  4. Bases en technique du vide

    CERN Document Server

    Rommel, Guy

    2017-01-01

    Cette seconde édition, 20 ans après la première, devrait continuer à aider les techniciens pour la réalisation de leur système de vide. La technologie du vide est utilisée, à présent, dans de nombreux domaines très différents les uns des autres et avec des matériels très fiables. Or, elle est souvent bien peu étudiée, de plus, c'est une discipline où le savoir-faire prend tout son sens. Malheureusement la transmission par des ingénieurs et techniciens expérimentés ne se fait plus ou trop rapidement. La technologie du vide fait appel à la physique, à la chimie, à la mécanique, à la métallurgie, au dessin industriel, à l'électronique, à la thermique, etc. Cette discipline demande donc de maîtriser des techniques de domaines très divers, et ce n'est pas chose facile. Chaque installation est en soi un cas particulier avec ses besoins, sa façon de traiter les matériaux et celle d'utiliser les matériels. Les systèmes de vide sont parfois copiés d'un laboratoire à un autre et le...

  5. Étude de l'emploi des peintures thermochromiques dans l'Art contemporain

    Directory of Open Access Journals (Sweden)

    Marjorie Nastro

    2012-06-01

    Full Text Available Cette étude sur l'utilisation des peintures thermochromiques est basée sur un cas concret, l’œuvre Mur - tableau (vert, conçue et réalisée en 2004 par Véronique Joumard. Elle a été menée dans le cadre d'un mémoire de fin d'études à l'École Supérieure d'Art d'Avignon, en collaboration avec le Laboratoire de chimie appliquée à l'art et à l'archéologie de l'Université d'Avignon, l'entreprise GEM'INNOV et la société MINOLTA. Elle a porté sur l’étude de caractéristiques physico-chimiques de ces couleurs dites "thermo-sensibles".This study on the use of thermochromic paintings is based on Véronique Joumard’s artwork Mur – tableau (vert, conceived and made in 2004. This research was led as a graduation project at Avignon’s Superior Art School  in collaboration with the laboratory of Chemistry applied to Art and Archeology (university of Avignon, GEM’INNOV and MINOLTA Ets. It focuses on the  physico-chimical features of “Thermosensitive” colors.

  6. Measurement of radioactive aerosols as an original indicator of atmospheric pollution in urban areas

    International Nuclear Information System (INIS)

    Le Petit, G.; Millies-Lacroix, J.-C.; Simon, F.

    1998-01-01

    The Service Radioanalyses, Chimie et Environnement (Departement Analyses Surveillance de l'Environnement) of the French Atomic Energy Commission, located in suburban Paris, has for many years been conducting atmospheric radioactivity measurements. Since 1994, the laboratory has been using high volume air samplers equipped with filters for the weekly collection of atmospheric aerosols at a mean rate of about 600 m 3 .h -1 . The polypropylene filters, with a collection efficiency in excess of 93%, are compacted after sampling. The atmospheric radioactivity is measured by HP Ge gamma spectrometry after decay of short-lived natural relationship products. A study conducted in 1996 shows good correlation between the evolution with time of some of the indicators routinely used by AIRPARIF, the organization in charge of monitoring of the air quality in the Ile-de-France region, to measure atmospheric pollution in the Paris area (SO 2 , NO) and that related to radioactivity of terrestrial ( 210 Pb, 40 K) and anthropogenic ( 137 Cs) origin, as well as the amount of aerosols collected. Further, the distribution in time of the atmospheric radioactivity of cosmogenic origin ( 7 Be) shows a yearly evolution somewhat similar to that observed with ozone. (author). 16 refs., 21 figs., 1 tab

  7. La fin des certitudes temps, chaos et les lois de la nature

    CERN Document Server

    Prigogine, Ilya

    1996-01-01

    « En cette fin de siècle, la question de l'avenir de la science est souvent posée. Je crois que nous sommes seulement au début de l'aventure. Nous assistons à l'émergence d'une science qui n'est plus limitée à des situations simplifiées, idéalisées, mais nous met en face de la complexité du monde réel, une science qui permet à la créativité humaine de se vivre comme l'expression singulière d'un trait fondamental de tous les niveaux de la nature. J'ai tenté de présenter cette transformation conceptuelle qui implique l'ouverture d'un nouveau chapitre dans l'histoire féconde des relations entre physique et mathématique sous une forme lisible et accessible à tout lecteur intéressé par l'évolution de nos idées sur la nature. Nous ne sommes qu'au début de ce nouveau chapitre de l'histoire de notre dialogue avec la nature. » Ilya PrigogineIlya Progogine, prix Nobel de chimie, est professeur à l'université libre de Bruxelles et à l'université du Texas à Austin.

  8. The future of humanity. How do we want to live tomorrow?; Die Zukunft der Menschheit. Wie wollen wir morgen leben?

    Energy Technology Data Exchange (ETDEWEB)

    Koenneker, Carsten (comp.)

    2017-07-01

    maennliche Unfruchtbarkeit waeren ein ethischer Dammbruch: Die Modifikationen wuerden weitervererbt); 4. Gerontologie: Der Methusalem-Effekt (Forscher untersuchen die Vorgaenge in Zellen, dank derer einzelne Menschen mehr als 100 Jahre leben); 5. Gesellschaft: Reiche Welt - arme Welt (In den Industrienationen stagniert die Einwohnerzahl, waehrend in den Entwicklungslaendern immer mehr Jugendliche nach Arbeit verlangen); 6. Ungleichheit: Gespaltene Gesellschaft (Spannungen, verschaerft durch Flucht und Migration, gefaehrden den sozialen Zusammenhalt); 7. Epidemiologie: Eine Diagnose der Menschheit (Globale Daten geben Aufschluss ueber den Gesundheitszustand der Erdbevoelkerung); 8. Geologie: Eine vielschichtige Angelegenheit; 9. Urbanistik: Die Stadt von morgen; 10. Technik: Energierevolution fuer Afrika (Der Kontinent koennte voll auf sauberen Strom setzen); 11. Transhumanismus: Wollen wir ewig leben? 12. Soziale Kontakte: Lass das, Papa, nicht googeln. (Sherry Turkle warnt vor dem staendigen Vernetztsein.); 13. Anthropozaen: Apokalypse oder Aufbruch? (Wir bestimmen das Schicksal des intelligenten Lebens). Ein Beitrag wurde fuer diese Datenbank separat aufgenommen.

  9. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of the total phosphorus by a Kjeldahl digestion method and an automated colorimetric finish that includes dialysis

    Science.gov (United States)

    Patton, Charles J.; Truitt, Earl P.

    1992-01-01

    A method to determine total phosphorus (TP) in the same digests prepared for total Kjeldahl nitrogen (TKN) determinations is desribed. The batch, high-temperature (block digester), HG(II)-catalyzed digestion step is similar to U.S. Geological Survey methods I-2552-85/I-4552-85 and U.S. Environmental Protection Agency method 365.4 except that sample and reagent volumes are halved. Prepared digests are desolvated at 220 degrees Celsius and digested at 370 degrees Celsius in separate block digesters set at these temperatures, rather than in a single, temperature-programmed block digester. This approach is used in the method escribed here, which permits 40 calibrants, reference waters, and smaples to be digested and resolvated in about an hour. Orthophosphate ions originally present in samples, along with those released during the digestion step, are determined colorimetrically at a rate of 90 tests per hour by an automated version of the phosphoantimonylmolybdenum blue procedure. About 100 microliters of digest are required per determination. The upper concentration limit is 2 milligrams per liter (mg/L) with a method detection limt of 0.01 mg/L. Repeatability for a sample containing approximately 1.6 mg/L of TP in a high suspended-solids matrix is 0.7 percent. Between-day precision for the same sample is 5.0 percent. A dialyzer in the air-segmented continuous flow analyzer provides on-line digest cleanup, eliminated particulates that otherwise would interfere in the colorimetric finish. An single-channel analyzer can process the resolvated digests from two pairs of block digesters each hour. Paired t-test analysis of TP concentrations for approximately 1,600 samples determined by the new method (U.S. Geologial Survey methods I-2610-91 and I-4610-91) and the old method (U.S. Geological Survey methods I-2600-85 and I-4600-85) revealed positive bias in the former of 0.02 to 0.04 mg/L for surface-water samples in agreement with previous studies. Concentrations of total

  10. Deep Structures of The Angola Margin

    Science.gov (United States)

    Moulin, M.; Contrucci, I.; Olivet, J.-L.; Aslanian, D.; Géli, L.; Sibuet, J.-C.

    1 Ifremer Centre de Brest, DRO/Géosciences Marines, B.P. 70, 29280 Plouzané cedex (France) mmoulin@ifremer.fr/Fax : 33 2 98 22 45 49 2 Université de Bretagne Occidentale, Institut Universitaire Europeen de la Mer, Place Nicolas Copernic, 29280 Plouzane (France) 3 Total Fina Elf, DGEP/GSR/PN -GEOLOGIE, 2,place de la Coupole-La Defense 6, 92078 Paris la Defense Cedex Deep reflection and refraction seismic data were collected in April 2000 on the West African margin, offshore Angola, within the framework of the Zaiango Joint Project, conducted by Ifremer and Total Fina Elf Production. Vertical multichannel reflection seismic data generated by a « single-bubble » air gun array array (Avedik et al., 1993) were recorded on a 4.5 km long, digital streamer, while refraction and wide angle reflection seismic data were acquired on OBSs (Ocean Bottom Seismometers). Despite the complexity of the margin (5 s TWT of sediment, salt tectonics), the combination of seismic reflection and refraction methods results in an image and a velocity model of the ground structures below the Aptian salt layer. Three large seismic units appear in the reflection seismic section from the deep part on the margin under the base of salt. The upper seismic unit is layered with reflectors parallel to the base of the salt ; it represents unstructured sediments, filling a basin. The middle unit is seismically transparent. The lower unit is characterized by highly energetic reflectors. According to the OBS refraction data, these two units correspond to the continental crust and the base of the high energetic unit corresponds to the Moho. The margin appears to be divided in 3 domains, from east to west : i) a domain with an unthinned, 30 km thick, continental crust ; ii) a domain located between the hinge line and the foot of the continental slope, where the crust thins sharply, from 30 km to less than 7 km, this domain is underlain by an anormal layer with velocities comprising between 7,2 and 7

  11. Mechanical behavior and localized failure modes in a porous basalt from the Azores

    Science.gov (United States)

    Loaiza, S.; Fortin, J.; Schubnel, A.; Guéguen, Y.; Moreira, M.; Vinciguerra, S.

    2012-04-01

    Basaltic rocks are the main component of the oceanic upper crust. This is of potential interest for water and geothermal resources, or for storage of CO2. The aim of our work is to investigate experimentally the mechanical behavior and the failure modes of porous basalt as well as the permeability evolution during deformation. Cylindrical basalt samples, from the Azores, of 30 mm in diameter and 60 mm in length were deformed the triaxial cell of the Laboratoire de Geologie at the Ecole Normale Supérieure (Paris) at room temperature and at a constant axial strain rate of 10-5 s-1. The initial porosity of the sample was 18%. The Geodesign triaxial cell can reach 300MPa confining pressure; axial load is performed through a piston and can reach 900 MPa (for a 30mm diameter sample); maximum pore pressure is 100MPa (applied using two precision volumetric pumps). In our study, a set of experiments were performed at confining pressure in the range of 25-290 MPa. The samples were deformed under saturated conditions at a constant pore pressure of 5MPa. Two volumetric pumps kept the pore pressure constant, and the pore volume variations were recorded. The evolution of the porosity was calculated from the total volume variation inside the volumetric pumps. Permeability measurements were performed using the steady-state technique. Our result shows that two modes of deformation can be highlighted in this basalt. At low confining pressure (Pc < 50 MPa), the differential stress attains a peak before the sample undergoes strain softening; the failure of sample occurs by shear localization. Yet, the brittle regime is commonly observed in this low Pc range, the experiments performed at confining pressure higher than 50 MPa, show a totally different mode of deformation. In this second mode of deformation, an appreciable inelastic porosity reduction is observed. Comparing to the hydrostatic loading, the rock sample started to compact beyond a critical stress state; and from then

  12. Why does the Size of the Laacher See Magma Chamber and its Caldera Size not go together? - New Findings with regard to Active Tectonics in the East Eifel Volcanic Field

    Science.gov (United States)

    Schreiber, Ulrich; Berberich, Gabriele

    2013-04-01

    catalogue. Department of Earthquake Geology of Cologne University. http://www.seismo.uni-koeln.de/catalog/index.htm Bogaard v.d. P (1983): Die Eruption des Laacher See Vulkans. Ph.D. Thesis, Bochum, Ruhr-Universität, 348 p. Campbell J, Kümpel HJ, Fabian M, Fischer D, Görres B, Keysers Ch & Lehmann K (2002): Recent movement patterns of the Lower Rhine Embayment from tilt, gravity and GPS data, Netherlands Journal of Geosciences / Geologie en Mijnbouw, 81(2): 223--230 Hinzen KG (2003): Stress field in the Northern Rhine area, Central Europe, from earthquake fault plane solutions. Tectonophysics, 377: 325-356. Holland P, Emmerson DE (1987): Determination of the helium-4 content of near surface atmospheric air within the continental United States. Journal of Geophysical Research, 92: 12557-12556. Holohan EP, van Wyk de Vries B & Troll V (2005): Analogue models of caldera collapse in strike-slip tectonic regimes. Bull. Volcanol, 70, 773-796. Loos J, Juch D & Ehrhardt W (1999): Äquidistanzen von Blattverschiebungen - neue Erkenntnisse zur Lagerstättenbearbeitung im Ruhrkarbon.- Zeitschrift für angewandte Geologie, 45: 26 - 36. Meyer W & Stets J (2002): Pleistocene to Recent tectonics in the Rhenish Massif (Germany). Netherlands Journal of Geosciences / Geologie en Mijnbouw, 81 (2): 217-221) Schreiber U & Berberich G (2012): Monitoring geogener Gase in der West-, Ost- und Südeifel sowie im Mittelrhein-/Lahngebiet im Auftrag des Landesamtes für Geologie und Bergbau Rheinland-Pfalz, Mainz, Endbericht (unveröff.), 37 S. v. d. Bogaard P & Schmincke HU (1984): The Eruptive Center of the Late Quarternary Laacher See Tephra. - Geologische Rundschau, 73: 933-980. Viereck LG & v.d. Bogaard P (1986): Magma- und Wärmeinhalt der Magmakammer des Laacher See und des Riedener Vulkans. Forschungsbericht T 86-174. Bundesministerium für Forschung und Technologie (BMFT).

  13. High resolution carbon isotope stratigraphy and glendonite occurrences of the Christopher Formation, Sverdrup Basin (Axel Heiberg Island, Canada): implications for mid Cretaceous high latitude climate change

    Science.gov (United States)

    Herrle, Jens O.; Schröder-Adams, Claudia J.; Galloway, Jennifer M.; Pugh, Adam T.

    2013-04-01

    glendonites are concentrated in regular beds during the late Aptian to early Albian of the Christopher Formation supporting the idea of a cold snap (Kemper, 1987; Herrle & Mutterlose 2003; Mutterlose et al. 2009) within the mid-Cretaceous greenhouse period. References Herrle, J.O., Mutterlose, J., 2003. Calcareous nannofossils from the Aptian - early Albian of SE France: Paleoecological and biostratigraphic implications. Cretaceous Research 24, 1-22. Kemper, E., 1987. Das Klima der Kreide-Zeit. Geologisches Jahrbuch 96, 185 pp. Mutterlose, J., Bornemann, A., Herrle, J.O., 2009. The Aptian - Albian cold snap: Evidence for "mid" Cretaceous icehouse interludes. Neues Jahrbuch für Geologie und Palaeontologie, Abhandlungen 252, 217-225.

  14. Reworked Middle Jurassic sandstones as a marker for Upper Cretaceous basin inversion in Central Europe—a case study for the U-Pb detrital zircon record of the Upper Cretaceous Schmilka section and their implication for the sedimentary cover of the Lausitz Block (Saxony, Germany)

    Science.gov (United States)

    Hofmann, Mandy; Voigt, Thomas; Bittner, Lucas; Gärtner, Andreas; Zieger, Johannes; Linnemann, Ulf

    2018-04-01

    The Saxonian-Bohemian Cretaceous Basin (Elbsandsteingebirge, E Germany and Czech Republic, Elbtal Group) comprises Upper Cretaceous sedimentary rocks from Upper Cenomanian to Santonian age. These sandstones were deposited in a narrow strait of the sea linking the northern Boreal shelf to the southern Tethyan areas. They were situated between the West Sudetic Island in the north and the Mid-European Island in the south. As known by former studies (e.g. Tröger, Geologie 6/7:717-730, 1964; Tröger, Geologie von Sachsen, Schweizerbart, 311-358, 2008; Voigt and Tröger, Proceedings of the 4th International Cretaceous Symposium, 275-290, 1996; Voigt, Dissertation, TU Bergakademie Freiberg, 1-130, 1995; Voigt, Zeitschrift der geologischen Wissenschaften 37(1-2): 15-39, 2009; Wilmsen et al., Freiberger Forschungshefte C540: 27-45, 2011) the main sedimentary input came from the north (Lausitz Block, southern West-Sudetic Island). A section of Turonian to Coniacian sandstones was sampled in the Elbsandsteingebirge near Schmilka (Elbtal Group, Saxony, Germany). The samples were analysed for their U-Pb age record of detrital zircon using LA-ICP-MS techniques. The results show main age clusters typical for the Bohemian Massif (local material) and are interpreted to reflect the erosion of uniform quartz-dominated sediments and basement rocks. Surprisingly, these rocks lack an expected Upper Proterozoic to Lower Palaeozoic age peak, which would be typical for the basement of the adjacent Lausitz Block (c. 540-c. 560 Ma). Therefore, the Lausitz Block basement must have been covered by younger sediments that acted as source rocks during deposition of the Elbtal Group. The sandstones of the Elbe valley (Elbtal Group, Schmilka section) represent the re-deposited sedimentary cover of the Lausitz Block in inverse order. This cover comprised Permian, Triassic, Jurassic and Lower Cretaceous deposits, which are eroded already today and cannot be investigated. Within the samples of the

  15. Petrography and mineral chemistry of metamorphosed mantle peridotites of Nain Ophiolite (Central Iran

    Directory of Open Access Journals (Sweden)

    Nargess Shirdashtzadeh

    2017-07-01

    expense of Ca-free mineral of serpentine. Tremolite were produced after chrysotile, talc, and chlorite, wherever enough Ca2+ ions were released from the associated olivine and/or orthopyroxene by serpentinization. Discussion Petrographical and geochemical studies indicate a greenschist-facies stage (serpentinization and chloritization followed and overprinted by amphibolite-facies metamorphism. The regional metamorphism is verified by the formation of antigorite after lizardite and chrysotile, metamorphic olivine neoblasts after serpentines, chlorite after Cr-spinel, talc after olivine and orthopyroxene, and tremolite after pyroxene, talc, serpentine, and chlorite. The metamorphism imprints on harzburgite and dunite indicate that metamorphism has occurred after melt-rock reactions. Acknowledgment The authors appreciate Prof. Shoji Arai for providing geochemical facilities. References Ghasemi, A. and Talbot, C.J., 2006. A new tectonic scenario for the Sanandaj-Sirjan Zone (Iran. Journal of Asian Earth Science, 26(6: 683-693. Ghazi, J.M., Moazzen, M., Rahgoshay, M. and Shafaii Moghadam, H., 2010. Mineral chemical composition and geodynamic significance of peridotites from Nain ophiolite, Central Iran. Journal of Geodynamics, 49(5: 261-270. Shirdashtzadeh, N., Torabi, G. and Arai, S., 2010. Metamorphism and metasomatism in the Jurassic of Nain ophiolitic mélange, Central Iran. Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen, 255(3: 255–275. Shirdashtzadeh, N., Torabi, G., Meisel, T., Arai, S., Bokhari, S.N.H., Samadi, R. and Gazel, E., 2014a. Origin and evolution of metamorphosed mantle peridotites of Darreh Deh (Nain Ophiolite, Central Iran: Implications for the Eastern Neo-Tethys evolution. Neues Jahrbuch für Geologie und Paläontologie – Abhandlungen, 273(1: 89–120. Shirdashtzadeh, N., Torabi, G. and Samadi, R., 2014b. Geochemistry of pillow lavas and their clinopyroxene: ophiolitic mélanges of Nain and Ashin (Northeast of Isfahan Province

  16. Are They Climbing the Pyramid? Rating Student-Generated Questions in a Game Design Project / Grimpent-ils la pyramide? Évaluation des questions produites par les étudiants dans un projet de conception de jeux

    Directory of Open Access Journals (Sweden)

    Jason Paul Siko

    2013-02-01

    Full Text Available Researchers have examined the use of homemade PowerPoint games as an instructional technique to improve learning outcomes. However, test data have shown no significant difference in performance between high school chemistry students who created games and students who did not (Siko, Barbour, & Toker, 2011. One of the justifications for the use of the games is that students will, with practice, write higher-order questions when constructing the games. Two subject matter experts rated over 2,500 questions from games created by students in an environmental chemistry class through thematic analysis using Bloom’s taxonomy as a coding scheme. The students wrote primarily recall questions, and students who created games on two occasions did not write more questions than students who only created games once. This suggests that changes to the question-writing aspect of the game project may be necessary in order to see improvements in achievement when compared to control groups. Les chercheurs ont étudié l’usage de jeux PowerPoint maison en tant que technique pédagogique visant à améliorer les résultats d'apprentissage. Les données des tests n'ont toutefois révélé aucune différence significative quant au niveau de performance des étudiants du secondaire en chimie ayant créé des jeux et celui des étudiants n’en ayant pas conçus (Siko, Barbour, et Toker, 2011. L’utilisation des jeux est notamment justifiée par l’idée que, pratique aidant, les étudiants écrivent des questions plus complexes lorsqu’ils élaborent des jeux. Au moyen d’une analyse thématique utilisant la taxonomie de Bloom comme système de codification, deux experts chimistes ont évalué plus de 2500 questions provenant de jeux conçus par des étudiants d’une classe de chimie environnementale. Les étudiants ont rédigé principalement des questions faisant appel à la mémoire, et les étudiants ayant créé des jeux à deux reprises n’ont pas produit

  17. Marcoule institute for separation chemistry - ICSM. Scientific report 2007 - 2010

    International Nuclear Information System (INIS)

    2010-01-01

    The mixed research unit 'Institute for Separation Chemistry' was created jointly by CEA, CNRS, University of Montpellier and Ecole Nationale superieure de Chimie de Montpellier has obtained authorisation to start experiments including a few grams of depleted uranium and natural thorium in January 2010. Last takeoff was from our theory group, who started in October 2009. But the unit 'Institut de Chimie separative de Marcoule' existed as a team scattered in several places in France since 2007. At that time, monthly meetings gathered people for full days of open discussion every month, as 'Point ICSM', where colleagues from R/D Departments of the centre of Marcoule composed half of the audience. Scientific activity began in 2007 with progressive joining of ICSM of team leaders, co-workers, technicians and students, today with 38 permanent staff and 29 nonpermanent scientists and students. Most of the staff joined ICSM after or before participating to the European practical summer school in Analytical and separation chemistry, hold yearly for a full week including practical sessions since the first edition 2006 in Montpellier. Resources in Uranium are scarce, if only the 235 isotope is used. Wastes related to nuclear energy production are potentially dangerous. Since fifty years, the chemistry associated to nuclear energy production always followed the principles of green chemistry. Permanent attention in devoted to closing the life-cycle of materials and fuel, minimize wastes and ascertain the acceptability by a society via knowledge of chemistry and physical chemistry involved in the chemistry used for separation. Developing knowledge in order to propose new separation processes is the central aim of the ICSM. Enlarging this central goal to surfaces of materials, sono-chemistry as an example of green chemistry, chemistry and physical chemistry specific to actinides complete this picture. Thus, the ICSM is devoted to chemistry at the service of the nuclear energy of

  18. Application of a Detailed Emission Model for Heavy Duty Diesel Engine Simulations Application d'un modèle détaillé d'émissions pour la simulation de gros moteurs diesel

    Directory of Open Access Journals (Sweden)

    Magnusson I.

    2006-12-01

    Full Text Available A detailed chemical model describing the formation of soot and NO is applied to simulate emission formation in a heavy duty diesel engine. Cylinder flow and spray development is simulated using an engine CFD code - Speedstar. Combustion is described using a simple eddy break-up model. Modeling of the emission-chemistry/turbulent-flow interaction is based on a flamelet approach. Contrary to a typical flamelet concept, transport equations are solved for mass fractions of soot and NO. The reason being that these major emission constituencies are assumed to change slowly in comparison to typical time scales for chemical processes or transport processes important for combustion. Chemical reactions leading to production and destruction of soot and NO are, however, assumed to be fast. Soot and NO source terms are therefore evaluated from a flamelet library using a presumed probability density function and integrating over mixture fraction space. Results from simulations are compared to engine measurements inform of exhaust emission data and cylinder pressure. Un modèle avec chimie détaillée décrivant la formation des suies et du NO est appliqué à la simulation de la formation des polluants dans un gros moteur Diesel. L'écoulement et le spray sont modélisés avec le code de calcul Speedstar. La combustion est représentée par le modèle eddy break-up . La modélisation de l'interaction entre l'écoulement turbulent et la chimie des polluants est basée sur une approche de type flamelet . Cependant, à la différence d'autres travaux, des équations de transport pour les fractions massiques de suies et de NO sont résolues. Cela est justifié par la supposition que les temps caractéristiques de formation de ces composés sont longs comparés à ceux associés aux phénomènes de transport et aux réactions chimiques associées à la combustion. Cependant, les vitesses de réaction se rapportant aux suies et au NO sont supposées rapides. Cela

  19. Preparation, definition and stabilisation of an inorganic sol by an organic macromolecule: case of an aluminium hydroxide colloid; Preparation, definition et stabilisation par une macromolecule organique d'un sol mineral: cas d'un colloide d'hydroxyde d'aluminium

    Energy Technology Data Exchange (ETDEWEB)

    Hurbin-Faucon, A [Commissariat a l' Energie Atomique, Centre d' Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France)

    1966-07-01

    limites de certaines techniques de physico-chimie colloidale. Le colloide d'aluminium est obtenu par peptisation d'un precipite d'hydroxyde d'aluminium. La caracterisation physique de la micelle est fuite a l'aide de la methode de la diffusion lumineuse qui permet de definir le colloide du point de vue taille et forme. Une particularite interessante, due a la faible valeur de l'indice de refraction du colloide en etude, nous a amene a utiliser, non seulement les methodes generales du MIE, mais aussi les methodes habituellement employees en chimie macromoleculaire, qui demandent moins d'hypotheses et permettent ainsi une analyse plus complete du sol. Le colloide d'hydroxyde d'aluminium ne resistant pas a une force ionique elevee, nous avons aborde a ce sujet le probleme de sa stabilisation par une macromolecule: la gelatine. Apres avoir caracterise cette macromolecule par des mesures potentiometriques et de diffusion lumineuse, nous avons mis en evidence l'interaction de nature chimique qui se produit lorsqu'on met en presence l'hydrosol d'aluminium et la gelatine; cette interaction conduit a l'obtention d'une entite organo-minerale resistant a une augmentation de force ionique. Nous avons etabli quelques caracteristiques du complexe ainsi forme, notamment son domaine de formation en fonction du pH de la solution, sa stabilite en presence d'electrolytes, hypotheses sur sa taille et sa forme. Nous avons enfin tente de definir l'influence de la masse moleculaire et des dimensions respectives de chaque constituant sur la formation du complexe et de la sur la stabilisation. (auteur)

  20. Synthetic Or Reformulated Fuels: a Challenge for Catalysis Carburants de synthèse ou reformulés : un défi pour la catalyse

    Directory of Open Access Journals (Sweden)

    Courty P.

    2006-12-01

    Full Text Available Despite comparative figures for wordwide crude oil and natural gas proven reserves, present time contribution of syngas chemistry to motorfuels remains marginal when the refining industry is faced to main constraints: market demand evolution, stringent specifications and environmental issues. Actually natural gas upgrading via syngas chemistry yields key products (e. g. methanol among which clean motorfuels (ethers, FT products should develop despite the huge investments required, mostly for syngas production. Main challenges and corresponding issues for catalysts and related technologies are identified for Fischer-Tropsch synthesis and motorfuels long-term reformulation. Among other, mastering the chain-growth (FT synthesis improving the FCC products: gasoline, and LCO for Diesel pool. All these issues need significant progresses in catalyst and technology to be solved. Lastly, our economical study, focused on Diesel-fuel production, shows up that clean diesel (from SR-LCO mixtures and FT Diesel reach similar production costs when cheap NG is available. In the future, FT middle distillates should amount to a few percent (5-150 Mt of the 1700-2000 Mt of transport middle distillates expected from oil refining. However they should more and more be a compulsory part of diesel pool if the level of investment for an FT process continues to decrease significantly. Malgré des réserves prouvées en pétrole et en gaz du même ordre de grandeur, la contribution de la chimie du gaz de synthèse à la production de carburants reste marginale, alors que l'industrie du raffinage est confrontée à des contraintes majeures : évolution de la demande, durcissement des spécifications des produits et contraintes environnementales. Cependant, la conversion chimique du gaz, via la chimie du gaz de synthèse, fournit des produits stratégiques (e. g. méthanol parmi lesquels les carburants propres (éthers, produits Fischer-Tropsch devraient se développer, bien

  1. Heavy ion irradiation of crystalline water ice. Cosmic ray amorphisation cross-section and sputtering yield

    Science.gov (United States)

    Dartois, E.; Augé, B.; Boduch, P.; Brunetto, R.; Chabot, M.; Domaracka, A.; Ding, J. J.; Kamalou, O.; Lv, X. Y.; Rothard, H.; da Silveira, E. F.; Thomas, J. C.

    2015-04-01

    Context. Under cosmic irradiation, the interstellar water ice mantles evolve towards a compact amorphous state. Crystalline ice amorphisation was previously monitored mainly in the keV to hundreds of keV ion energies. Aims: We experimentally investigate heavy ion irradiation amorphisation of crystalline ice, at high energies closer to true cosmic rays, and explore the water-ice sputtering yield. Methods: We irradiated thin crystalline ice films with MeV to GeV swift ion beams, produced at the GANIL accelerator. The ice infrared spectral evolution as a function of fluence is monitored with in-situ infrared spectroscopy (induced amorphisation of the initial crystalline state into a compact amorphous phase). Results: The crystalline ice amorphisation cross-section is measured in the high electronic stopping-power range for different temperatures. At large fluence, the ice sputtering is measured on the infrared spectra, and the fitted sputtering-yield dependence, combined with previous measurements, is quadratic over three decades of electronic stopping power. Conclusions: The final state of cosmic ray irradiation for porous amorphous and crystalline ice, as monitored by infrared spectroscopy, is the same, but with a large difference in cross-section, hence in time scale in an astrophysical context. The cosmic ray water-ice sputtering rates compete with the UV photodesorption yields reported in the literature. The prevalence of direct cosmic ray sputtering over cosmic-ray induced photons photodesorption may be particularly true for ices strongly bonded to the ice mantles surfaces, such as hydrogen-bonded ice structures or more generally the so-called polar ices. Experiments performed at the Grand Accélérateur National d'Ions Lourds (GANIL) Caen, France. Part of this work has been financed by the French INSU-CNRS programme "Physique et Chimie du Milieu Interstellaire" (PCMI) and the ANR IGLIAS.

  2. Multi-year assimilation of IASI and MLS ozone retrievals: variability of tropospheric ozone over the tropics in response to ENSO

    Science.gov (United States)

    Peiro, Hélène; Emili, Emanuele; Cariolle, Daniel; Barret, Brice; Le Flochmoën, Eric

    2018-05-01

    The Infrared Atmospheric Sounder Instrument (IASI) allows global coverage with very high spatial resolution and its measurements are promising for long-term ozone monitoring. In this study, Microwave Limb Sounder (MLS) O3 profiles and IASI O3 partial columns (1013.25-345 hPa) are assimilated in a chemistry transport model to produce 6-hourly analyses of tropospheric ozone for 6 years (2008-2013). We have compared and evaluated the IASI-MLS analysis and the MLS analysis to assess the added value of IASI measurements. The global chemical transport model MOCAGE (MOdèle de Chimie Atmosphérique à Grande Echelle) has been used with a linear ozone chemistry scheme and meteorological forcing fields from ERA-Interim (ECMWF global reanalysis) with a horizontal resolution of 2° × 2° and 60 vertical levels. The MLS and IASI O3 retrievals have been assimilated with a 4-D variational algorithm to constrain stratospheric and tropospheric ozone respectively. The ozone analyses are validated against ozone soundings and tropospheric column ozone (TCO) from the OMI-MLS residual method. In addition, an Ozone ENSO Index (OEI) is computed from the analysis to validate the TCO variability during the ENSO events. We show that the assimilation of IASI reproduces the variability of tropospheric ozone well during the period under study. The variability deduced from the IASI-MLS analysis and the OMI-MLS measurements are similar for the period of study. The IASI-MLS analysis can reproduce the extreme oscillation of tropospheric ozone caused by ENSO events over the tropical Pacific Ocean, although a correction is required to reduce a constant bias present in the IASI-MLS analysis.

  3. Autour de l’Oedipus chymicus :

    Directory of Open Access Journals (Sweden)

    Anne-Lise Rey

    2008-03-01

    Full Text Available A partir de la comparaison entre l’Oedipus chymicus de Leibniz écrit en 1710 et ce qui nous a semblé un possible référent, le texte homonyme de J.J Becher de 1664, l’article s’efforce de déterminer les raisons de l’attrait que Leibniz éprouve pour la chimie de son temps. Si les pratiques de codage et de décodage de la démarche alchimique ainsi que l’attention portée aux transformations des états de la matière constituent indéniablement des points de convergence avec la philosophie leibnizienne, il ne nous semble néanmoins pas possible de conclure de là à une influence de la philosophie chimique, et en particulier de la notion de semence, sur la constitution de la monade leibnizienne.Comparing the Leibniz’s Oedipus chymicus, written in 1710, with its possible reference, the homonymous text by J.J. Becher in 1664, this paper tries to determine why Leibniz had such an interest for the chemistry of his time. If the alchemical practices of coding and decoding and the attention alchemists paid to the modifications of the matter are indeed points of convergence with leibnizian philosophy, it’s nevertheless impossible to conclude to an influence of chemical philosophy, especially of the notion of seed, on the constitution of leibnizian’s monad.

  4. Pulse polarography - special application; Polarographie a impulsions - applications particulieres

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    The calculation of the current on a plane electrode in particular conditions is presented briefly, the first part of the report then consists of a theoretical and methodological presentation of pulse polarography. The calculation of the current in pulse polarography is given for different modes of measurement and for redox systems of variable reversibility. Various extensions are proposed with a view to extending the field of application of the method. The second part presents two particular applications. One application is to analytical chemistry: organometallic complexes applied to the pulse polarographic analysis; the other application is to electrochemical kinetics using integral pulse polarography. This research has enabled us to determine, in the first case, elements present in minute traces, and in the second case the kinetic parameters of an electrochemical reaction which is too fast to be analyzed by conventional polarography. (author) [French] Apres un rappel sur le calcul du courant sur electrode plane dans des conditions precises, la premiere partie du memoire est consacree a l'expose theorique et methodologique de la polarographie a impulsions. Le calcul du courant en polarographie a impulsions est donne pour divers modes de mesures et pour des systemes redox de reversibilites variees. Diverses extensions sont proposees de facon a elargir le domaine d'application de la methode. La deuxieme partie introduit deux applications particulieres. Une application a la chimie analytique: les complexes organometalliques appliques a l'analyse pulsopolarographique et une application a la cinetique electrochimique par polarographie a impulsions integrale. Ces recherches nous ont permis de determiner dans le premier cas, des elements a l'etat de traces infimes, dans le deuxieme cas, les parametres cinetiques d'une reaction electrochimique trop rapide pour etre analysee par polarographie classique. (auteur)

  5. Romanian Words of Arabic Origin: Scientific and Technical Vocabulary

    Directory of Open Access Journals (Sweden)

    Georgeta Rata

    2016-10-01

    Full Text Available There are 141 Romanian words of Arabic origin acquired either directly from Arabic or else indirectly by passing from Arabic into other languages and then into Romanian. Most entered one or more of the Romance languages before entering Romanian. To qualify for this list, a word must be reported in etymology dictionaries as having descended from Arabic. Words associated with the Islamic religion are omitted. Archaic and rare words are also omitted. Given the nature of the journal in which the paper is to be published, the author selected for analysis only about 126 terms belonging to the scientific and technical vocabulary: Adobe, alambic, albatros, alcalin, alchimie, alcool, alfalfa, algebră, algoritm, alidadă, alizarină, amalgam, ambră, anil, antimoniu, azimuth, azur, benjoin, bezoar, bor, cafea, calibre, camfor, carat, carciofoi, caric, cârmâz, carob, chimie, cifru, coton, curcuma, cuşcuş, erg, falafel, fanfară, felucă, fenec, gazelă, gerbil, girafă, halva, hamada, humus, iasomie, jar, julep, kaliu, lac, lămâie, lazurit, liliac, lime, marcasit, masicot, mizenă, muson, nadir, natriu, papagal, rachetă, realgar, sabkha, safari, şah, sandarac, şaorma, şerbet, sirop, sodium, şofran, sorbet, spanac, sumac, tabac, tahân, taifun, talc, tamarin(d, tangerină, tar, tară, tarhon, tarif, tasă, ţechin, ton, varan, zahăr, zenith, zero, zircon, etc. Some of them are obsolescent, but a large number are in everyday use and have been so well assimilated into Romanian that they have produced other words through derivation and composition, or they have acquired new meanings.

  6. FACULTĂȚILE DE LA UNIVERSITATEA DIN CERNĂUȚI (1875-1919

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    Constantin UNGUREANU

    2017-08-01

    Full Text Available În perioada 1875-1919, Universitatea din Cernăuţi a funcţionat cu trei facultăţi: teologie ortodoxă, drept şi filozofie. Un rol aparte în cadrul Universităţii l-a îndeplinit Facultatea de Teologie Ortodoxă. La această facultate au activat 15 pro­fesori titulari, dintre care 13 români şi doi ucraineni. Facultatea de Drept a fost cea mai bine frecventată. Facultatea de Filozofie din Cernăuţi a cuprins mai multe secţii: filozofie, istorie, filologie şi lingvistică, matematică şi ştiinţe naturale, limbi moderne, fizică, chimie. În ajunul războiului, la această facultate activau 28 de catedre, dintre care 16 în domeniul ştiinţelor filologice şi istorice şi 12 în domeniul ştiinţelor naturale.FACULTIES AT THE UNIVERSITY OF CHERNIVTSI (1875-1919During 1875-1919,ChernivtsiUniversitywas comprised of three faculties: orthodox theology, law and philosophy. The Faculty of Orthodox Theology played a special role within the University. This department was comprised of 15 full professors, of which 13 were Romanian and 2 Ukrainians. Faculty of Law was the best frequented. The Faculty of Philosophy in Chernivtsi was comprised of several departments such as philosophy, history, philology and linguistics, mathematics and natural sciences, modern languages, physics and chemistry. Just before the Great War, this Faculty was comprised of 28 departments of which 16 were specialized in philology and history while 12 were specialized in the natural sciences.

  7. Science et technologie du collage

    CERN Document Server

    Cognard, Jacques

    2003-01-01

    L'Homme a su coller avant de savoir écrire et compter. Le collage est en effet l'une des premières techniques d'assemblage d'une structure que l'homme ait utilisée, technique qui n'est devenue science qu'au début du 20e siècle avec la fabrication des premières colles synthétiques. Cette science de l'adhésion a considérablement progressé ces dix dernières années et ce livre présente l'état actuel des connaissances en décrivant les progrès considérables réalisés dans la compréhension des phénomènes fondamentaux qui font qu'un collage tient bien et durablement. Après l'exposé des bases scientifiques nécessaires et des modèles théoriques récents, l'auteur introduit la distinction entre collages faibles et collages forts puis expose les difficultés rencontrées dans les cas pratiques, difficultés souvent dues à la complexité de la chimie des surfaces et des réactions surface-polymère. L'ouvrage se termine par la présentation de quelques applications récentes, en particulier dans...

  8. Une nouvelle orientation dans l’enseignement supérieur au vietnam: de la mémoire à la résolution de problèmes

    Directory of Open Access Journals (Sweden)

    TRƯƠNG Quang Dũng

    2016-12-01

    Full Text Available L’enseignement supérieur traditionnel est essentiellement basé sur la transmission du savoir et occasionnellement sur celle du savoir-faire. Il se réclame donc des disciplines universitaires (mathématiques, physique, chimie, géologie.... dispensées dans les universités et grandes écoles. Or, la réussite professionnelle et sociale dans le monde moderne exige d’autres acquis plus probants que des connaissances pures. Plusieurs recherches récentes ont ainsi montré que la résolution de bien des problèmes requiert des qualités pragmatiques d’efficacité indispensables pour l’accomplissement d’un travail créatif. Résoudre un problème revient alors à apprendre à maitriser une démarche méthodique composée de plusieurs phases, depuis l’identification du problème jusqu’à sa solution finale en passant par l’analyse judicieuse des causes. Il faut également maîtriser l’utilisation d’outils conceptuels et Méthodologiques tels que, entre autres, la « loi de Pareto », le questionnement systématique et le brainstorming . Au Vietnam on peut espérer la mise en application de ces nouvelles orientations dans un enseignement supérieur qui doit absolument se fixer comme objectif d’améliorer la qualité du travail social pour répondre aux nouvelles exigences de développement du pays.

  9. Preconcentration of uranium ores by radio-metric sorting; Preconcentration des minerais d'uranium par triage radiometrique

    Energy Technology Data Exchange (ETDEWEB)

    Avril, R; Grenier, J [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1964-07-01

    The uranium ore chemical treatment plant at Bessines-sur-Gartempe is supplied entirely by the La Crouzille Mining Division of the French Atomic Energy Commission mainly from mining districts of Fanay, Margnac and Le BRUGEAUD in the Limousin province and also, for the remainder, by a certain amount of private production in the 'Massif Central'. The supply mixture, which is very heterogeneous, is enriched before being treated chemically. The pre-concentration operation is carried out in the divisions ore treatment work-shop. It consists in a stone removal operation using radiometric sorting along a continuous belt; this makes it possible to eliminate 50 pour cent of the only fraction which is thus treated - that from 50 to 120 mm; it represents 15 to 20 per cent of the total tonnage supplied to the plant. (authors) [French] L'usine chimique de traitement des minerais d'uranium de Bessines-sur-Gartempe est entierement alimentee par la Division Miniere de La Crouzille, du Commissariat a l'Energie Atomique, principalement a partir des ensembles miniers limousins de Fanay, Margnac et du Brugenud et, pour le complement, par une certaine production privee en provenance du Massif Central. Le melange d'alimentation, tres heterogene, est enrichi avant d'etre livre a la chimie. L'operation de preconcentration est realisee dans l'atelier de preparation des minerais de la division. Il s'agit d'un epierrage par triage radiometrique sur bande, en continu, qui permet d'eliminer 50 pour cent de la seule fraction granulometrique qui le subit - le 50-120 mm - soit encore 15 a 20 pour cent du tonnage global d'alimentation livre a l'usine. (auteurs)

  10. Validity of satellite measurements used for the monitoring of UV radiation risk on health

    Directory of Open Access Journals (Sweden)

    F. Jégou

    2011-12-01

    Full Text Available In order to test the validity of ultraviolet index (UVI satellite products and UVI model simulations for general public information, intercomparison involving three satellite instruments (SCIAMACHY, OMI and GOME-2, the Chemistry and Transport Model, Modélisation de la Chimie Atmosphérique Grande Echelle (MOCAGE, and ground-based instruments was performed in 2008 and 2009. The intercomparison highlighted a systematic high bias of ~1 UVI in the OMI clear-sky products compared to the SCIAMACHY and TUV model clear-sky products. The OMI and GOME-2 all-sky products are close to the ground-based observations with a low 6 % positive bias, comparable to the results found during the satellite validation campaigns. This result shows that OMI and GOME-2 all-sky products are well appropriate to evaluate the UV-risk on health. The study has pointed out the difficulty to take into account either in the retrieval algorithms or in the models, the large spatial and temporal cloud modification effect on UV radiation. This factor is crucial to provide good quality UV information. OMI and GOME-2 show a realistic UV variability as a function of the cloud cover. Nevertheless these satellite products do not sufficiently take into account the radiation reflected by clouds. MOCAGE numerical forecasts show good results during periods with low cloud covers, but are actually not adequate for overcast conditions; this is why Météo-France currently uses human-expertised cloudiness (rather than direct outputs from Numerical Prediction Models together with MOCAGE clear-sky UV indices for its operational forecasts. From now on, the UV monitoring could be done using free satellite products (OMI, GOME-2 and operational forecast for general public by using modelling, as long as cloud forecasts and the parametrisation of the impact of cloudiness on UV radiation are adequate.

  11. Nucleation of metastable aragonite CaCO3 in seawater.

    Science.gov (United States)

    Sun, Wenhao; Jayaraman, Saivenkataraman; Chen, Wei; Persson, Kristin A; Ceder, Gerbrand

    2015-03-17

    Predicting the conditions in which a compound adopts a metastable structure when it crystallizes out of solution is an unsolved and fundamental problem in materials synthesis, and one which, if understood and harnessed, could enable the rational design of synthesis pathways toward or away from metastable structures. Crystallization of metastable phases is particularly accessible via low-temperature solution-based routes, such as chimie douce and hydrothermal synthesis, but although the chemistry of the solution plays a crucial role in governing which polymorph forms, how it does so is poorly understood. Here, we demonstrate an ab initio technique to quantify thermodynamic parameters of surfaces and bulks in equilibrium with an aqueous environment, enabling the calculation of nucleation barriers of competing polymorphs as a function of solution chemistry, thereby predicting the solution conditions governing polymorph selection. We apply this approach to resolve the long-standing "calcite-aragonite problem"--the observation that calcium carbonate precipitates as the metastable aragonite polymorph in marine environments, rather than the stable phase calcite--which is of tremendous relevance to biomineralization, carbon sequestration, paleogeochemistry, and the vulnerability of marine life to ocean acidification. We identify a direct relationship between the calcite surface energy and solution Mg:Ca [corrected] ion concentrations, showing that the calcite nucleation barrier surpasses that of metastable aragonite in solutions with Mg:Ca ratios consistent with modern seawater, allowing aragonite to dominate the kinetics of nucleation. Our ability to quantify how solution parameters distinguish between polymorphs marks an important step toward the ab initio prediction of materials synthesis pathways in solution.

  12. [From apprenticeship to Nobel Prize: Henri Moissan's fabulous destiny].

    Science.gov (United States)

    Lafont, O

    2008-01-01

    Born in Paris on September 28, 1852, son of an eastern railways' employee and of a dressmaker, Henri Moissan's secondary schooling in Meaux did not allow him to get access to the sesame diploma "baccalauréat" (GCE). In 1869, he did obtain a special certificate of secondary schooling so that he could become an apprentice in watch making. That could have been the end of the story, but dreadful event for France appeared to have beneficial effects for Moissan. Under the threat of the Prussian army, Moissan's family took refuge near Paris. This gave the young Henri the opportunity to register as a student for the second-class pharmacy diploma, which did not need, at the time, the GCE. Moissan became then a trainee in pharmacy in 1871. Meanwhile, he followed the special schooling of "Ecole de chimie" founded by E. Frémy, and then joined the laboratory of Dehérain at the Museum, where he worked in plant physiology. He finally obtained the famous "baccalauréat" (GCE) and could register as a student in first-class pharmacy. He became a pharmacist as well as a doctor in sciences. In 1883, Moissan was named professor at the school of pharmacy in Paris. In 1886, he isolated fluorine by electrolysis of fluorhydric acid, in the presence of potassium fluoride, at a low temperature. He then studied diamond synthesis and gave a start to high temperature chemistry, designing his famous furnace. These findings and many others allowed Moissan to rise to membership in many learned academies around the world. Crowning achievement, Moissan won the Nobel Prize in 1906. A man of culture, collector of autographs and paintings, he died in 1907. Nothing of that would have been possible if there had not been a second-class pharmacist diploma. The history of Henri Moissan is one of a rise from apprenticeship to the Nobel Prize.

  13. Cold pearl surfactant-based blends.

    Science.gov (United States)

    Crombie, R L

    1997-10-01

    Pearlizing agents have been used for many years in cosmetic formulations to add a pearlescent effect. Cold pearl surfactant-based blends are mixtures of glycol stearates and surfactants which can be blended in the cold into a wide range of personal-care formulations to create a pearlescent lustre effect. Under controlled manufacturing conditions constant viscosities and crystalline characteristics can be obtained. The development of these blends has been driven by efforts to improve the economics of adding solid pearlizing agents directly into a hot mix formulation. This paper summarizes the history of pearlizers, describes their advantages and physical chemistry of the manufacturing process. Finally some suggestions for applications are given. Les agents nacrants sont utilises depuis de nombreuses annees dans les formulations cosmetiques pour ajouter un effet nacre. Les melanges a froid a base de tensioactif nacre sont des melanges de stearates de glycol et de tensioactifs qui peuvent etre melanges a froid dans une large gamme de formulations d'hygiene personnelle pour creer un effet de lustre nacre. On peut obtenir des viscosites et des proprietes cristallines constantes avec des conditions de fabrication maitrisees. Le developpement de ces melanges a ete porte par les efforts pour ameliorer les couts de l'ajout d'agents nacrants solides directement dans une formulation melangee de l'ajout d'agents nacrants solides directement dans une formulation melangee a chaud. Cet article resume l'histoire des agents nacrants, decrit leurs avantages et al physico-chimie du procede de fabrication. On emet a la fin cetaines suggestions d'applications.

  14. [Regarding respiration and the so-called "animal heat." An historical sketch].

    Science.gov (United States)

    de Micheli, A

    2001-01-01

    According to Aristotle and Galen, the essential function of the respiration phenomenon was to cool the blood. Towards the middle of the XVI Century, Miguel Servet suggested, in his treatise Christianismi restitutio..., that the inspired air could have other functions besides cooling the blood. Later, Joseph Black thought that respiration was a combustion. In the light of the advances in chemistry achieved in the XVII Century, the English scientist Adair Crawford and the French chemist Antoine-Laurent Lavoisier conceived, in the second half of that century, the first general and quantitative theories on the origin of animal heat. Both these authors had the conviction that the "inflammable element", which will be called oxygen, was not formed in the pulmonary territory, but could be absorbed by the blood. Oxygen, foreseen by Mayow at the end of XVII Century, was discovered by Joseph Priestley in 1774. Lavoisier gave the name of oxygen to this gas and firmly established that the respiration phenomenon consists essentially in a process of combustion. The mathematician Joseph-Louis Lagrange, native of Turin, suggested that animal heat originates in all breathing tissues. This phenomenon was verified and described in detail by the biologist Lazzaro Spallanzani, professor at the University of Pavia. Dissemination, in the scientific world, of the new chemical nomenclature and of the respiratory theory, closely related to it, was based fundamentally on the works "Méthode de nomenclature chimique..." (1787) and "Traité élémentaire de chimie..." (1789). During the XIX Century, studies on the phenomenon of animal respiration continued and fundamental discoveries in this subject were attained, such as conversion of hemoglobin to oxyhemoglobin once oxygen had been fixed. Now it is possible to study the regulating mechanisms of the energetic metabolism of the myocardium in vivo, which allows decisive interventions in certain cardiopathies, such as in acute ischemic

  15. Towards the development of a novel bioinspired functional material: synthesis and characterization of hybrid TiO2/DHICA-melanin nanoparticles.

    Science.gov (United States)

    Pezzella, Alessandro; Capelli, Luigia; Costantini, Aniello; Luciani, Giuseppina; Tescione, Fabiana; Silvestri, Brigida; Vitiello, Giuseppe; Branda, Francesco

    2013-01-01

    A large number of recent literature data focus on modification/modulation of surface chemistry of inorganic materials in order to improve their functional properties. Melanins, a wide class of natural pigments, are recently emerging as a powerful organic component for developing bioinspired active material for a large number of applications from organoelectronics to bioactive compounds. Here we report the use of the approach referred as "chimie douce", involving in situ formation of the hybrids through reactions of precursors under mild conditions, to prepare novel hybrid functional architectures based on eumelanin like 5,6 dihydroxyindole-2-carboxylic acid (DHICA) polymer and TiO2. Two synthesis procedures were carried out to get DHICA-melanin coated TiO2 nanoparticles as well as mixed DHICA/TiO2 hybrid nanostructures. Such systems were characterized through EPR, FT-IR and fluorescence spectroscopy, thermogravimetric analysis (TGA), X-ray diffraction (XRD), and TEM microscopy in order to assess the effect of synthesis path as well as of DHICA content on structural, morphological and optical properties of TiO2 nanostructures. In particular, EPR, FT-IR spectra and TGA analysis confirmed the presence of DHICA-melanin in these samples. TEM measurements indicated the formation of the nanoparticles having relatively narrow size distribution with average particle size of about 10nm. DHICA-melanin does act as a morphological agent affecting morphology of hybrid nanostructures. XRD analysis proved that TiO2 hybrid nanoparticles kept anatase structures for DHICA-melanin contents within the range of investigated compositions, i.e. up to 50% wt/wt. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Aerosol Transport Over Equatorial Africa

    Science.gov (United States)

    Gatebe, C. K.; Tyson, P. D.; Annegarn, H. J.; Kinyua, A. M.; Piketh, S.; King, M.; Helas, G.

    1999-01-01

    Long-range and inter-hemispheric transport of atmospheric aerosols over equatorial Africa has received little attention so far. Most aerosol studies in the region have focussed on emissions from rain forest and savanna (both natural and biomass burning) and were carried out in the framework of programs such as DECAFE (Dynamique et Chimie Atmospherique en Foret Equatoriale) and FOS (Fires of Savanna). Considering the importance of this topic, aerosols samples were measured in different seasons at 4420 meters on Mt Kenya and on the equator. The study is based on continuous aerosol sampling on a two stage (fine and coarse) streaker sampler and elemental analysis by Particle Induced X-ray Emission. Continuous samples were collected for two seasons coinciding with late austral winter and early austral spring of 1997 and austral summer of 1998. Source area identification is by trajectory analysis and sources types by statistical techniques. Major meridional transports of material are observed with fine-fraction silicon (31 to 68 %) in aeolian dust and anthropogenic sulfur (9 to 18 %) being the major constituents of the total aerosol loading for the two seasons. Marine aerosol chlorine (4 to 6 %), potassium (3 to 5 %) and iron (1 to 2 %) make up the important components of the total material transport over Kenya. Minimum sulfur fluxes are associated with recirculation of sulfur-free air over equatorial Africa, while maximum sulfur concentrations are observed following passage over the industrial heartland of South Africa or transport over the Zambian/Congo Copperbelt. Chlorine is advected from the ocean and is accompanied by aeolian dust recirculating back to land from mid-oceanic regions. Biomass burning products are transported from the horn of Africa. Mineral dust from the Sahara is transported towards the Far East and then transported back within equatorial easterlies to Mt Kenya. This was observed during austral summer and coincided with the dying phase of 1997/98 El

  17. Flavonoids targeting of IκB phosphorylation abrogates carcinogen-induced MMP-9 and COX-2 expression in human brain endothelial cells

    Directory of Open Access Journals (Sweden)

    Tahanian E

    2011-05-01

    Full Text Available Elizabeth Tahanian¹, Luis Arguello Sanchez¹, Tze Chieh Shiao², René Roy², Borhane Annabi¹¹Centre de Recherche BioMED, ²Centre de Recherche PharmaQAM, Département de chimie, Université du Québec à Montréal, QC, CanadaAbstract: Brain endothelial cells play an essential role as structural and functional components of the blood–brain barrier (BBB. Increased BBB breakdown and brain injury are associated with neuroinflammation and are thought to trigger mechanisms involving matrix metalloproteinase upregulation. Emerging evidence also indicates that cyclooxygenase (COX inhibition limits BBB disruption, but the mechanisms linking metalloproteinase to COX remain unknown. In this study, we sought to investigate the nuclear factor-kappa B (NF-κB signaling pathway, a common pathway in both the regulation of matrix metalloproteinase-9 (MMP-9 and COX-2 expression, and the inhibitory properties of several chemopreventive flavonoids. Human brain microvascular endothelial cells were treated with a combination of phorbol 12-myristate 13-acetate (PMA, a carcinogen documented to increase MMP-9 and COX-2 through NF-κB, and several naturally occurring flavonoids. Among the molecules tested, we found that fisetin, apigenin, and luteolin specifically and dose-dependently antagonized PMA-induced COX-2 and MMP-9 gene and protein expressions as assessed by qRT-PCR, immunoblotting, and zymography respectively. We further demonstrate that flavonoids impact on IκK-mediated phosphorylation activity as demonstrated by the inhibition of PMA-induced IκB phosphorylation levels. Our results suggest that BBB disruption during neuroinflammation could be pharmacologically reduced by a specific class of flavonoids acting as NF-κB signal transduction inhibitors.Keywords: blood–brain barrier, flavonoids, neuroinflammation, NF-κB signal transduction inhibitors

  18. Thermodynamic studies of the complexation of plutonium(IV) by linear and macrocyclic poly-amino-carboxylate ligands

    International Nuclear Information System (INIS)

    Burgat, Romain

    2007-01-01

    In the framework of a collaboration between the CEA (Commissariat a l Energie Atomique) of Valduc and the ICMUB (Institut de Chimie Moleculaire de l Universite de Bourgogne), a study platform of the structural and physico-chemical properties of the radioelements U, Pu and Am complexes has been implemented. The plutonium(IV) complexation has been studied in a molar nitrate medium. The affinity of three linear poly-amino-carboxylates (EDTA, CDTA and DTPA) towards plutonium(IV) has then been estimated. For the three ligands, the formation constants of the monoleptic complexes Pu(EDTA), Pu(CDTA) and [Pu(DTPA)] - have been determined in a (H,K)NO 3 1 M medium and then extrapolated at a zero ionic force with the specific interactions theory (SIT). For the three complexes, mono-hydroxylated monoleptic species have been observed. With the EDTA and the CDTA, protonated dileptic complexes of a general formula [Pu(L) 2 H h ] (4-h)- have been revealed too. Nevertheless, the steric hindrance around the metallic center is too important to allow to a second molecule of DTPA to coordinate the Pu 4+ cation. The exclusive formation of the species [Pu(DTPA)] - and [Pu(DTPA)(OH)] 2- has been confirmed by capillary electrophoresis (EC-ICP-MS). On account of the preliminary results obtained during the titration of the cyclame tetraacetic product (TETRA) in presence of plutonium(IV), the adding of a competitive ligand such as EDTA has been considered for the study of the complexation of this radioelement by macrocyclic ligands. At last, the affinity of different macrocyclic ligands containing either four amide functions (TETAMMe 2 and TETAMMEt 2 ) or carboxylate groups (TETA, DOTPr and TETPr) towards lanthanides(III) has been estimated too. Although the complexation reaction be fast with the two first ligands, these complexes are less stable than those formed with the carboxylic macrocycles. (O.M.)

  19. Study of uranium(VI) speciation in phosphoric acid solutions and of its recovery by solvent extraction

    International Nuclear Information System (INIS)

    Dartiguelongue, Adrien

    2014-01-01

    Because small amounts of uranium are present in phosphate rocks, wet phosphoric acids may contain up to 300 ppm of uranium(VI). Therefore, such acids are a cost-effective unconventional source of this metal. Its recovery is a challenge for metallurgical firms which must develop reliable and selective solvent extraction processes. Such processes need to know the chemical equilibria involved in the extraction process, the speciation of uranium and its thermodynamics in solution. These two last points have been investigated in this work. Firstly, the most probable species of uranium(VI) in phosphoric acid solutions have been selected thanks to a detailed review of the literature. Then, a thermodynamic model founded on an equation of state for electrolytes has been built according these hypotheses. It has been validated with speciation data coming from original ATR-IR spectroscopy measurements. Finally, the composition of the aqueous phosphoric acid solutions and the activity coefficients obtained have been combined with a chemical model of uranium(VI) extraction into an organic phase containing a synergistic mixture of bis(2-ethylhexyl)phosphoric acid (D2EHPA) and tri-n-octylphosphine oxide (TOPO) in order to represent the variation of the distribution coefficient of uranium(VI) with H 3 PO 4 concentration. This model had been previously developed at Chimie ParisTech at a given concentration of H 3 PO 4 (i.e., 5,3 mol/L), but in the present study we have tested its validity in an extended range of phosphoric acid concentrations (i.e., 1-7 mol/L) and improved it. (author)

  20. La geografía del paisaje y el territorio cultural de Los Millares

    Directory of Open Access Journals (Sweden)

    Gusi i Jener, Francesc

    1991-12-01

    éographique ou se déroule. Malgré les données insuffisants du paleoenvironement qui se possédent sur tous les différents établissements qui appartient a la Culture de Los Millares, à l'avis des les auteurs il y avait une plus grande pluviosité, méme une plus ample coverture forestier dans tout le territoire de l'Andalousie orientale et Murcia, et pourtant une climatologie et un paysage géographique tout différent à l'actucl. D'une autre cóté, l'histoire de la recherche dans la Géugraphie s'avait polarisée depuis ses origines autour de ceux qui dessiraient que cette discipline fut plus proche à l'anthropologie et l'histoire, en face d'autres auteurs qui croyaient que son étude devait aborder des aspects simplement physiographiques, indépendamment de l'action humaine dans le milieu natural. On souligne aussi l'absence d'une coopération entre les archéologues el les géographes, pour étudier ensemble les problemes de la recherche à propos des territoires ocuppés pendant les periodes culturelles correspondant à I'Holocene. D'autre part l'apparition de I'Archéologie Spatial. comme une lendance de la recherche attachée a la géographie du territoirc et les différents positions idéologiques et méthodologiques de l'archeologie préhistorique, fréquemment ressemblables celles qui ont été suscitées pour les géographes, permetent comparer beaucoup d'aspects de cettes disciplines, liées étroitement à les sciences de la Terre et de I'Homme.

  1. Book Reviews

    Directory of Open Access Journals (Sweden)

    Redactie KITLV

    2003-04-01

    . Oxford: Butterworth-Heinemann, 2000, xiv + 293 pp., Stephen Page (eds -John McCarthy, Bernard Sellato, Forest, resources and people in Bulungan; Elements for a history of settlement, trade and social dynamics in Borneo, 1880-2000. Jakarta: Center for international forestry research (CIFOR, 2001, ix + 183 pp. -Naomi M. McPherson, Michael French Smith, Village on the edge; Changing times in Papua New Guinea. Honolulu: University of Hawai'i Press, 2002, xviii + 214 pp. -Gert J. Oostindie, Peter van Wiechen, Vademecum van de Oost- en West-Indische Compagnie Historisch-geografisch overzicht van de Nederlandse aanwezigheid in Afrika, Amerika, Azië en West-Australië vanaf 1602 tot heden. Utrecht: Bestebreurtje, 2002, 381 pp. -Gert J. Oostindie, C.L. Temminck Groll, The Dutch overseas; Architectural Survey; Mutual heritage of four centuries in three continents. (in cooperation with W. van Alphen and with contributions from H.C.A. de Kat, H.C. van Nederveen Meerkerk and L.B. Wevers, Zwolle: Waanders/[Zeist]: Netherlands Department for Conservation, [2002]. 479 pp. -Gert J. Oostindie, M.H. Bartels ,Hollanders uit en thuis; Archeologie, geschiedenis en bouwhistorie gedurende de VOC-tijd in de Oost, de West en thuis; Cultuurhistorie van de Nederlandse expansie. Hilversum: Verloren, 2002, 190 pp. [SCHI-reeks 2.], E.H.P. Cordfunke, H. Sarfatij (eds -Henk Schulte Nordholt, Tony Day, Fluid iron; State formation in Southeast Asia. Honolulu: University of Hawai'i Press, 2002, xii + 339 pp. -Nick Stanley, Nicholas Thomas ,Double vision; Art histories and colonial histories in the Pacific. Cambridge: Cambridge University Press, 1999, xii + 289 pp., Diane Losche, Jennifer Newell (eds -Heather Sutherland, David Henley, Jealousy and justice; The indigenous roots of colonial rule in northern Sulawesi. Amsterdam: VU Uitgeverij, 2002, 106 pp. -Gerard Termorshuizen, Piet Hagen, Journalisten in Nederland; Een persgeschiedenis in portretten 1850-2000. Amsterdam: Arbeiderspers, 2002, 600 pp. -Amy E

  2. Mineralization related to Alvand pluton in the Hamadan, western Iran

    Science.gov (United States)

    Salehi, M. H.; Doosti, E. A.; Ahadnejad, V.

    2009-04-01

    the expanded turmalinization has occurred but it is not seen any mineralization. Unless some small part of Alvand complex (i.e. stibnite in the Faghireh area, Maniijou and Aliani, 2000) and based on the main geochemical index, Alvand granitod pluton is classified as a barren type granite. References: Ghalamghash, J., Mirnejad, H., Rashid, H., Mohammadiha, K., Ghahraei-poor, M., Zakeri, M., 2007. Geochemistry of gabbro, granite and mafic enclaves of Alvand batholithe and their origin. 25th conference of geoscinces, Geological Survey of Iran. Maniijou, M., and Aliani, F., 2000. Stibnite mineralization in the Hamedan, west Iran. Mineral Deposits at the Beginning of the 21st Century: Proceedings of the Joint Sixth Biennial SGA-SEG Meeting, Krakow, Poland, 26-29 August 2001 By Adam Piestrzyński, Society for Geology Applied to Mineral Deposits, Society of Economic Geologists (U.S.) Published by Taylor & Francis. ISBN 9026518463, 9789026518461. 1148 pages. Sepahi, Ali A, 2008. Typology and petrogenesis of granitic rocks in the Sanandaj-Sirjan metamorphic belt, Iran: with emphasis on the Alvand plutonic complex. Neues Jahrbuch für Geologie Und Palaeontologie. Abhandlungen, 2008; 247 (3), 295-312.

  3. Numerical simulation of pore size dependent anhydrite precipitation in geothermal reservoirs

    Science.gov (United States)

    Mürmann, Mario; Kühn, Michael; Pape, Hansgeorg; Clauser, Christoph

    2013-04-01

    cementation in a 2D hypothetical core flooding experiment. With this new approach cementation patterns observed in the Allermöhe core samples can be explained now. The obtained results show that the variation of fluid supersaturation within a pore governs spatially heterogeneous anhydrite cementation. This variation and the fluid velocity determine the precipitation. Our numerical simulation results clearly emphasize the necessity to consider the spatial variation of supersaturation on the pore scale. References Baermann A., Kroeger J., Taugs R., Wuestenhagen K., Zarth M. (2000) Anhydrite cementation in Rhaetian Sandstone in Hamburg - Morphology and Structures, Zeitschrift für Angewandte Geologie, 46(3), 138-143 (in German). Clauser C. (2003) Numerical Simulation of Reactive Flow in Hot Aquifers. SHEMAT and processing SHEMAT, Springer Publishers, Heidelberg. Emmanuel S., Berkowitz B. (2007) Effects of pore size controlled solubility on reactive transport in heterogeneous rock, Geophysical Research Letters, 34, L06404. Putnis A., Mauthe G. (2001) The effect of pore size on cementation in porous rocks, Geofluids, 1, 37-41. Wagner R., Kühn M., Meyn V., Pape H., Vath U., Clauser C. (2005) Numerical simulation of pore space clogging in geothermal reservoirs by precipitation of anhydrite. International Journal of Rock Mechanics and Mining Sciences 42, 1070-1081, doi: 10.1016/ j.ijrmms.2005.05.008.

  4. Sandbox Tectonics As A Teaching Tool

    Science.gov (United States)

    Delaughter, J.

    2005-12-01

    obvious manner. Because the experiments produce tangible results, the students experience them on a more visceral level and may be able to incorporate the concepts better than they would through a description or computer simulation of the effects (Klosko et al., 2000). And, as the equipment used is very inexpensive, the experiment is well within the means of almost any school system. References Carey, S., R. Evans, M. Honda, E. Jay, C. Unger, 1989, ``An experiment is when you try it and see if it works'': A study of grade 7 students' understanding of the construction of knowledge, International Journal of Science Education, 11, 514-529 DeLaughter, J., S. Stein, C. Stein, K. R. Bain, 1998, Preconceptions abound among students in an introductory earth science course, EOS, 79, 429+432 Dominguez, S, J. Malavieille, S. Lallemand, 2000, Deformation of accretionary wedges in response to seamount subduction: Insights from sandbox experiments, Tectonics, 19(1), 182-196 Herbert, B., 2003, The role of scaffolding student metacognition in developing mental models of complex, Earth and environmental systems. DFG-NSF International Workshops on Research and Development in Mathematics and Science Education, November 19-21, 2003, Washington D.C. http://geoexplorer.tamu.edu/dfgnsf/WG1.html Horsfield, W.T., 1977, An experimental approach to basement controlled faulting, Geologie en Mijnbouw, 56, 363-370 Klosko, E., J. DeLaughter, S. Stein, 2000, Technology in introductory geophysics: the high - low mix, Computers & Geosciences, 26(6), 693-698

  5. Water geochemistry to estimate reservoir temperature of Stabio springs, Switzerland

    Science.gov (United States)

    Pera, Sebastian; Soma, Linda

    2017-04-01

    Elettrica Ticinese References Balderer, W., Leuenberger, F., Frei, C., Surbeck, H., & Synal, H. A. (2007). Origin of the Thermal Waters of Stabio (Switzerland) and Sirmione (Italy) based on Isotope and Chemical Investigations. In Symposium on advances in isotope hydrology and its role in sustainable water resources management; Vienna (Austria); 21-25 May 2007 (Vol. 39, pp. 631-641). IAEA. Bernoulli, D. (1964). Zur Geologie des Monte Generoso. Ein Beitrag zur Kenntnis der südalpinen Sedimente. Beiträge zur Geologischen Karte der Schweiz Karte Schweiz. N.F. 118. Greber, E., Leu, W., Schumacher, M. E., & Wyss, R. (1997). Hydrocarbon provinces in the Swiss Southern Alps-a gas geochemistry and basin modelling study Fsl. Marine and Petroleum Geology, 14(1), 3-25 IAEA. (1984). Isotopes Hydrology 1983. In Proc. Vienna Symposium 1984. Vienna: IAEA

  6. Contribution to uranium geochemistry in intrusive granites; Contribution a la geochimie de l'uranium dans les granites intrusifs

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-01-15

    certain nombre de massifs granitiques francais: - 3 massifs hercyniens francais, en Vendee, en Bretagne et dans le Morvan, - 1 massif africain, probablement precambrien, du Hoggar. Dans chaque massif, nous determinons en premier lieu le cadre petrochimique et evaluons le degre d'homogeneite chimique des roches. Dans les familles petrochimiques ainsi determinees, nous etudions le comportement geochimique de l'uranium. Du point de vue de la geochimie des granites etudies, le comparaison des lois de repartition des elements majeurs fait apparaitre dans les 4 massifs une convergence de composition moyenne que ne laissaient pas prevoir la geologie et la petrographie. Nous etablissons les lois de repartition statistiques et geographiques de l'uranium total en fonction des variations petrochimiques. L'etude des formes de l'uranium a l'interieur des roches a attire notre attention sur l'importance qualitative et quantitative de la fraction de cet uranium soluble dans les acides dilues. Nous reprenons donc, d'un cote les lois de repartition de l'uranium insoluble qui represente pratiquement l'uranium inclus dans les structures cristallines (zircon, allanite...) et justifions d'un autre cote l'interet presente par l'uranium soluble qui, malgre un caractere plus complexe, permet par son unite geochimique dans les phenomenes postmagmatiques, de trouver une liaison genetique entre les gisements uraniferes et les massifs intrusifs. Nous presentons enfin, un schema du cycle geochimique de l'uranium dans lequel nous esperons avoir pu apporter quelques precisions sur la phase ignee. (auteur)

  7. Traditional application of slates in Uruguay

    Science.gov (United States)

    Morales Demarco, Manuela; Cardenes Van den Eynde, Víctor

    2017-04-01

    width of these mica layers, being the former determinant for roofing slates, as according to Wagner (2007) slates with a number of mica layers per mm lower than 40 are not suitable as roofing and façade slates. All dolomitic slates have mass values below 40 (Morales Demarco et al, 2013), but this parameter has not been evaluated for the pelitic slates of Uruguay, and thus it remains unknown the potential of these rocks as roofing slates. Bentz A, Martini HJ (1968) Lehrbuch der Angewandten Geologie, Band 2, 1: Methoden zur Erforschung der Lagerstätten von Erzen, Kohle, Erdöl, Salzen, Industrie-Mineralen und Steinen und Erden. Sttutgart (Enke) DIN EN 12326-2 (2000) Schiefer und andere Natursteinprodukte für überlappende Dachdeckungen und Außenwandbekleidungen. Teil 2: Prüfverfahren. DIN Deutsches Institut für Normung e.V., Beuth, Berlin Morales Demarco M, Oyhantçabal P, Stein K-J, Siegesmund S (2013) Dolomitic slates from Uruguay: petrophysical and petromechanical characterization and deposit evaluation. Environ Earth Sci 69: 1361. doi:10.1007/s12665-012-1921-7 Wagner W (2007) Grundlagen für die Prüfung von Dach- und Wandschiefern. Z dt Ges Geowiss 158(4):785-805

  8. Contribution to uranium geochemistry in intrusive granites; Contribution a la geochimie de l'uranium dans les granites intrusifs

    Energy Technology Data Exchange (ETDEWEB)

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

    1959-01-15

    , un certain nombre de massifs granitiques francais: - 3 massifs hercyniens francais, en Vendee, en Bretagne et dans le Morvan, - 1 massif africain, probablement precambrien, du Hoggar. Dans chaque massif, nous determinons en premier lieu le cadre petrochimique et evaluons le degre d'homogeneite chimique des roches. Dans les familles petrochimiques ainsi determinees, nous etudions le comportement geochimique de l'uranium. Du point de vue de la geochimie des granites etudies, le comparaison des lois de repartition des elements majeurs fait apparaitre dans les 4 massifs une convergence de composition moyenne que ne laissaient pas prevoir la geologie et la petrographie. Nous etablissons les lois de repartition statistiques et geographiques de l'uranium total en fonction des variations petrochimiques. L'etude des formes de l'uranium a l'interieur des roches a attire notre attention sur l'importance qualitative et quantitative de la fraction de cet uranium soluble dans les acides dilues. Nous reprenons donc, d'un cote les lois de repartition de l'uranium insoluble qui represente pratiquement l'uranium inclus dans les structures cristallines (zircon, allanite...) et justifions d'un autre cote l'interet presente par l'uranium soluble qui, malgre un caractere plus complexe, permet par son unite geochimique dans les phenomenes postmagmatiques, de trouver une liaison genetique entre les gisements uraniferes et les massifs intrusifs. Nous presentons enfin, un schema du cycle geochimique de l'uranium dans lequel nous esperons avoir pu apporter quelques precisions sur la phase ignee. (auteur)

  9. Pliocene paleoenvironment evolution as interpreted from 3D-seismic data in the southern North Sea, Dutch offshore sector

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlmann, Gesa [Faculty of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht (Netherlands); Wong, Theo E. [Faculty of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht (Netherlands); TNO-NITG, National Geological Survey of the Netherlands, Princetonlaan 6, 3584 CB Utrecht (Netherlands)

    2008-02-15

    A high-resolution 3D-seismic survey from the Dutch offshore sector has been interpreted and subsequently correlated with existing regional seismo-stratigraphic concepts derived from conventional 2D-seismic data sets. The interpreted 13 seismic units have been related to a newly established chrono-stratigraphic framework [Kuhlmann et al., 2006a, b. Chronostratigraphy of Late Neogene sediments in the southern North Sea Basin and paleoenvironmental interpretations. Palaeogeography, Palaeoclimatology, Palaeoecology, 239, 426-455; Integrated chronostratigraphy of the Pliocene-Pleistocene interval and its relation to the regional stratigraphical stages in the southern North Sea region. Netherlands Journal of Geosciences-Geologie en Mijnbouw, 85(1), 19-35] resulting in up-dated age control for the seismic units. The generation of amplitude maps, time slices and isopach maps from the 3D-seismic data enabled detailed spatial and temporal reconstruction regarding the paleoenvironmental and climatological development as depicted by Kuhlmann et al. [2006a. Chronostratigraphy of Late Neogene sediments in the southern North Sea Basin and paleoenvironmental interpretations. Palaeogeography, Palaeoclimatology, Palaeoecology, 239, 426-455]. The lowermost seismic units S1-S4 comprise condensed Middle Miocene to Piacencian sediments, deposited under warm open marine conditions. These sediments show a uniform seismic facies of low-amplitude reflectors. The boundary of seismic unit S4-S5 (around 2.6 Ma) delineates a shift towards generally colder climate conditions that are connected to the onset of Northern Hemisphere Glaciation. Seismic unit S5 includes alternations of warmer and colder periods. During warmer periods, bottom currents generated elongated structures (2.5-4 km long, 300-500 m wide) on the horizon display. These layers show as well shallow gas accumulations with a more regional extent and are related to coarser-grained sediments sealed by clayey sediments of the cold

  10. Impact of river restoration on groundwater - surface water - interactions

    Science.gov (United States)

    Kurth, Anne-Marie; Schirmer, Mario

    2014-05-01

    Sensing (DTS), a fibre optical method for temperature determination over long distances (Selker et al., 2006). Thermal signatures were determined in a small urban stream before and after restoration and compared to streams in natural and near-natural settings. BWG BUNDESAMT FÜR WASSER UND GEOLOGIE, 2003. Die Geschichte des Hochwasserschutzes in der Schweiz. Bericht des BWG, Serie Wasser. Biel. 208 p. EA ENVIRONMENT AGENCY (UK), 2009. The Hyporheic Handbook: A handbook on the groundwater-surface water interface and hyporheic zone for environment managers. Bristol. 280 p. ANDREA, F., GSCHÖPF, C., BLASCHKE, A.P., WEIGELHOFER, G., AND RECKENDORFER, W., 2012. Ecological niche models for the evaluation of management options in urban floodplain - conservation vs. restoration purposes. Environ. Sci. Policy, http://dx.doi.org/10.1016/j.envsci.2012.08.011. PALMER, M.A., BERNHARDT, E.S., ALLAN, J.D., LAKE, P.S., ALEXANDER, G., BROOKS, S., CARR, J., CLAYTON, S., DAHM, C.N., FOLLSTAD SHAH, J., GALAT, D.L., LOSS, S.G., GOODWIN, P., HART, D.D., HASSETT, B., JENKINSON, R., KONDOLF, G.M., LAVE, R., MEYER, J.L., O`DONNELL, T.K., PAGANO, L. AND SUDDUTH, E., 2005. Standards for ecologically successful river restoration. Journal of Applied Ecology, 42, pp. 208 - 217. DOI 10.1111/j.1365-2664.2005.01004.x. WORTLEY, L., HERO, J-M., HOWES, M., 2013. Evaluating Ecological Restoration Success: A Review of the Literature. Restoration Ecology, 21 (5), pp. 537 - 543. DOI 10.1111/rec.12028. SELKER, J.S., THEVENAZ, L., HUWALD, H., MALLET, A., LUXEMBURG, W., VAN DE GIESEN, N., STEJSKAL, M., ZEMAN, J., WESTHOFF, M., AND PARLANGE, M.B., 2006. Distributed fibre-optic temperature sensing for hydrologic systems. Water Resources Research, 42(12), W12202.

  11. Pompes à chaleur dans l'industrie Heat Pumps in Industry

    Directory of Open Access Journals (Sweden)

    Benchecroun N.

    2006-11-01

    Full Text Available Les pompes à chaleur pourraient permettre une réduction de la consommation énergétique de l'industrie française estimée à 3,5 Mtep à l'horizon 1990 (300 000 tep en 1982. Ces installations se situeront dans les domaines du chauffage des locaux industriels, du séchage à basse température, du réchauffage de liquides et de certaines opérations de fractionnement. Pour les utilisations dans des procédés industriels les secteurs concernés sont principalement les industries agroalimentaires et, à plus long terme, celui de la chimie (y compris pétrochimie. On constate que les ventes de machines de forte puissance restent faibles (environ 500 de 1973 à 1982. Le climat général d'investissement, la nécessité d'adapter les procédés à l'utilisation d'une pompe à chaleur, et le faible niveau de température Heat pumps could be used to reduce energy consumption by French industry which may attain 3. 5 million tOE by 1990 (300 000 tOE in 1982. Such installations will be used in the fields of industrial space heating, low-temperature drying, the heating of liquids and various fractionating operations. For uses in industrial processes, the sectors involved are mainly agribusiness and food industries and, in the longer range, the chemical industry (including petrochemicals. Sales of high-powered machinery are still low (about 500 from 1973 to 1982. The general investment climate, the need to adapt processes to the use of heat pumps, and the low temperature level (< 120 °C of the heat delivered are the main factors holding back the penetration of this type of equipment in industry. The use of a nonazeotropic mixture of fluids (particularly hydrocarbons gives compression heat pumps a flexibility of adaptation which should help remove these technicalobstacles and thus make it easier for heat pumps to penetrate, especially in the chemical sector.

  12. L’olivier au Maroc

    Directory of Open Access Journals (Sweden)

    El Mouhtadi Issam

    2014-03-01

    Full Text Available L’olivier est une culture traditionnelle sur le pourtour de la Méditerranée. Il est donc naturel de trouver cet arbre au Maroc où il est présent depuis des siècles. Cultivé surtout traditionnellement jusqu’à ses dernières années, il fait l’objet maintenant d’un plan de valorisation très ambitieux pour non seulement garder le Royaume à son niveau actuel (2e producteur mondial pour l’olive de conserve et 6e pour l’huile d’olive mais pour conquérir de nouveaux marchés au niveau mondial et profiter ainsi de l’engouement que connaît cette huile reconnue pour ses bienfaits. Le plan national « Maroc Vert » permet ainsi, grâce à des subventions conséquentes, non seulement de renouveler les vergers existant avec la variété traditionnelle picholine du Maroc, mais également la plantation de nouvelles variétés en super-intensif dans le but d’industrialiser au maximum de nouveaux vergers. Il en est de même pour la transformation des olives en huile de bonne qualité avec la mise en place d’unités de trituration modernes qui doivent supplanter à terme la multitude de « maâsra » et réduire ainsi l’impact environnemental dû aux margines. L’olive ne sera plus dans l’avenir que représentée par son huile et ses formes comestibles, mais les résidus de son extraction seront valorisés soit sous forme de combustible élaboré pour le grignon, soit sous forme d’une base de chimie verte pour les sous-produits du raffinage. D’autres applications sont actuellement à l’étude, car le Maroc à compris, comme tous les autres grands pays producteurs, que l’olive était un nouveau gisement de richesses.

  13. Thz Spectroscopy of 13C Isotopic Species of a "weed": Acetaldehyde

    Science.gov (United States)

    Margulès, L.; Motiyenko, R. A.; Guillemin, J.-C.

    2011-06-01

    Our studies of the isotopic species of 13C and D isotopologues of methyl formate (HCOOCH_3), have allowed the detection of more than 600 lines in Orion. This confirms that many observed U-lines are coming from isotopic species of one of the most abundant molecules in space. Since its first detection in 1976 in SgrB2 and in Orion A, acetaldehyde (CH_3CHO) was detected in many other numerous objects. If its deuterated species (CD_3CHO and CH_3CDO) have been previously studied in the millimeterwave range, the data concerning the 13C species are limited to few lines measured in 1957 up to 40 GHz. In this context we decided to study the 13C species of acetaldehyde. Acetaldehyde molecule displays a large amplitude motion: the hindered rotation of the methyl group with respect to the rest of the molecule. The analysis is performed with the Rho Axis Method. Recent versions of the codes include high orders term in order to reproduce the observed frequencies for large quantum numbers values as J-values as high as 70a,b,. Measurements and analysis of the rotational spectra of 13C isotopic species are in progress in Lille with a solid-state submillimetre-wave spectrometer (50-950 GHz), the first results will be presented. This work is supported by the contract ANR-08-BLAN-0054 and by the Programme National de Physico-Chimie du Milieu Interstellaire (PCMI-CNRS). Carvajal, M.; Margulès, L.; Tercero, B.; et al.A&A 500, (2009) 1109 Margulès, L.; Huet, T. R.; Demaison J.; et al.,ApJ 714, (2010) 1120. Ikeda, M.; Ohishi, M.; Nummelin, A.; et al., ApJ, 560, (2001) 792 Kleiner, I.; Lopez, J.-C.; Blanco, S.; et al.J. Mol. Spectrosc. 197, (1999) 275 Elkeurti M.; Coudert, L. H.; Medvedev, I. R.; et al.J. Mol. Spectrosc. 263, (2010) 145 Kilb, R.W.; Lin, C.C.; and Wilson, E.B.J. Chem. Phys. 26, (1957) 1695 Kleiner, I. J. Mol. Spectrosc. 260, (2010) 1 Ilyushin, V.V.; Kryvda, A; and Alekseev, E;J. Mol. Spectrosc. 255, (2009) 32

  14. Dome C ultracarbonaceous Antarctic micrometeorites. Infrared and Raman fingerprints

    Science.gov (United States)

    Dartois, E.; Engrand, C.; Duprat, J.; Godard, M.; Charon, E.; Delauche, L.; Sandt, C.; Borondics, F.

    2018-01-01

    financed by the French INSU-CNRS program "Physique et Chimie du Milieu Interstellaire" (PCMI).

  15. Aerosol data assimilation in the chemical transport model MOCAGE during the TRAQA/ChArMEx campaign: aerosol optical depth

    Science.gov (United States)

    Sič, Bojan; El Amraoui, Laaziz; Piacentini, Andrea; Marécal, Virginie; Emili, Emanuele; Cariolle, Daniel; Prather, Michael; Attié, Jean-Luc

    2016-11-01

    In this study, we describe the development of the aerosol optical depth (AOD) assimilation module in the chemistry transport model (CTM) MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle). Our goal is to assimilate the spatially averaged 2-D column AOD data from the National Aeronautics and Space Administration (NASA) Moderate-resolution Imaging Spectroradiometer (MODIS) instrument, and to estimate improvements in a 3-D CTM assimilation run compared to a direct model run. Our assimilation system uses 3-D-FGAT (first guess at appropriate time) as an assimilation method and the total 3-D aerosol concentration as a control variable. In order to have an extensive validation dataset, we carried out our experiment in the northern summer of 2012 when the pre-ChArMEx (CHemistry and AeRosol MEditerranean EXperiment) field campaign TRAQA (TRAnsport à longue distance et Qualité de l'Air dans le bassin méditerranéen) took place in the western Mediterranean basin. The assimilated model run is evaluated independently against a range of aerosol properties (2-D and 3-D) measured by in situ instruments (the TRAQA size-resolved balloon and aircraft measurements), the satellite Spinning Enhanced Visible and InfraRed Imager (SEVIRI) instrument and ground-based instruments from the Aerosol Robotic Network (AERONET) network. The evaluation demonstrates that the AOD assimilation greatly improves aerosol representation in the model. For example, the comparison of the direct and the assimilated model run with AERONET data shows that the assimilation increased the correlation (from 0.74 to 0.88), and reduced the bias (from 0.050 to 0.006) and the root mean square error in the AOD (from 0.12 to 0.07). When compared to the 3-D concentration data obtained by the in situ aircraft and balloon measurements, the assimilation consistently improves the model output. The best results as expected occur when the shape of the vertical profile is correctly simulated by the direct model. We

  16. A linear CO chemistry parameterization in a chemistry-transport model: evaluation and application to data assimilation

    Directory of Open Access Journals (Sweden)

    M. Claeyman

    2010-07-01

    Full Text Available This paper presents an evaluation of a new linear parameterization valid for the troposphere and the stratosphere, based on a first order approximation of the carbon monoxide (CO continuity equation. This linear scheme (hereinafter noted LINCO has been implemented in the 3-D Chemical Transport Model (CTM MOCAGE (MOdèle de Chimie Atmospherique Grande Echelle. First, a one and a half years of LINCO simulation has been compared to output obtained from a detailed chemical scheme output. The mean differences between both schemes are about ±25 ppbv (part per billion by volume or 15% in the troposphere and ±10 ppbv or 100% in the stratosphere. Second, LINCO has been compared to diverse observations from satellite instruments covering the troposphere (Measurements Of Pollution In The Troposphere: MOPITT and the stratosphere (Microwave Limb Sounder: MLS and also from aircraft (Measurements of ozone and water vapour by Airbus in-service aircraft: MOZAIC programme mostly flying in the upper troposphere and lower stratosphere (UTLS. In the troposphere, the LINCO seasonal variations as well as the vertical and horizontal distributions are quite close to MOPITT CO observations. However, a bias of ~−40 ppbv is observed at 700 Pa between LINCO and MOPITT. In the stratosphere, MLS and LINCO present similar large-scale patterns, except over the poles where the CO concentration is underestimated by the model. In the UTLS, LINCO presents small biases less than 2% compared to independent MOZAIC profiles. Third, we assimilated MOPITT CO using a variational 3D-FGAT (First Guess at Appropriate Time method in conjunction with MOCAGE for a long run of one and a half years. The data assimilation greatly improves the vertical CO distribution in the troposphere from 700 to 350 hPa compared to independent MOZAIC profiles. At 146 hPa, the assimilated CO distribution is also improved compared to MLS observations by reducing the bias up to a factor of 2 in the tropics

  17. Radically Different Kinetics at Low Temperatures

    Science.gov (United States)

    Sims, Ian

    2014-06-01

    The use of the CRESU (Cinétique de Réaction en Ecoulement Supersonique Uniforme, or Reaction Kinetics in Uniform Supersonic Flow) technique coupled with pulsed laser photochemical kinetics methods has shown that reactions involving radicals can be very rapid at temperatures down to 10 K or below. The results have had a major impact in astrochemistry and planetology, as well as proving an exacting test for theory. The technique has also been applied to the formation of transient complexes of interest both in atmospheric chemistry and combustion. Until now, all of the chemical reactions studied in this way have taken place on attractive potential energy surfaces with no overall barrier to reaction. The F + H2 {→} HF + H reaction does possess a substantial energetic barrier ({\\cong} 800 K), and might therefore be expected to slow to a negligible rate at very low temperatures. In fact, this H-atom abstraction reaction does take place efficiently at low temperatures due entirely to tunneling. I will report direct experimental measurements of the rate of this reaction down to a temperature of 11 K, in remarkable agreement with state-of-the-art quantum reactive scattering calculations by François Lique (Université du Havre) and Millard Alexander (University of Maryland). It is thought that long chain cyanopolyyne molecules H(C2)nCN may play an important role in the formation of the orange haze layer in Titan's atmosphere. The longest carbon chain molecule observed in interstellar space, HC11N, is also a member of this series. I will present new results, obtained in collaboration with Jean-Claude Guillemin (Ecole de Chimie de Rennes) and Stephen Klippenstein (Argonne National Labs), on reactions of C2H, CN and C3N radicals (using a new LIF scheme by Hoshina and Endo which contribute to the low temperature formation of (cyano)polyynes. H. Sabbah, L. Biennier, I. R. Sims, Y. Georgievskii, S. J. Klippenstein, I. W. M. Smith, Science 317, 102 (2007). S. D. Le Picard, M

  18. Construction of dry-boxes for plutonium metallurgy; Construction des boites a gants pour la metallurgie du plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Grison, E; Pascard, R [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1958-07-01

    The dry-boxes used at Chatillon are of two main types: a) boxes with a metal frame work of welded angle-pieces, panels of plexiglass, bakelite, duralumin, etc... They include a standard panel which enables them to be connected up to the contaminated repairs workshop; b) boxes made entirely of welded plastic. The working face only is of plexiglas held by screw clamps to a pure rubber joint. These boxes, which cannot be connected to the contaminated workshop, are generally reserved for small pieces of chemical apparatus. None has yet been used for working under argon, although their airtightness is excellent. After an interval of several hours, in fact, no decrease in the pressure inside the box can be detected. Several means can be adopted to ensure that the joints between panels and mountings are absolutely air-tight. Up to the present we are using three types of box with metal framework at the same time, without being able to make a definitive choice. (author) [French] Les boites a gants utilisees a Chatillon sont de deux types principaux: a) boites a armature metallique en cornieres soudees, panneaux en plexiglas, bakelite, duralumin, etc... Elles comportent un panneau standard permettant de les raccorder a l'atelier de reparations contamine; b) boites entierement en matiere plastique soudee. Seule la face de travail est en plexiglas appliquee par serre-joints sur un joint de caoutchouc pur. Ces boites, qui ne peuvent etre raccordees a l'atelier contamine, sont en general reservees a du petit materiel de chimie. Aucune, jusqu'a present, n'a ete utilisee pour le travail sous argon bien que leur etancheite soit excellente. On ne detecte en effet sur un intervalle de plusieurs heures aucune diminution de la depression regnant dans la boite. Plusieurs solutions peuvent etre adoptees pour assurer l'etancheite des panneaux sur les montants. Jusqu'a ce jour, nous utilisons concurremment trois types de boites a armature metallique sans qu'il soit possible de faire un

  19. From the coupling between ion beam analysis techniques and physico-chemical characterization methods to the study of irradiation effects on materials behaviour

    International Nuclear Information System (INIS)

    Millard-Pinard, N.

    2003-01-01

    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

  20. 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

  1. Marcoule Institute for Separation Chemistry - 2009-2012 Scientific report

    International Nuclear Information System (INIS)

    Pellet-Rostaing, Stephane; Zemb, Thomas

    2013-01-01

    The mixed research unit 'Institute for Separation Chemistry' was created jointly by CEA, CNRS, University of Montpellier and Ecole Nationale Superieure de Chimie de Montpellier in March 2007. The building has been inaugurated in June 2009, with laboratories opened in the fall 2009 and has obtained authorisation to start experiments including a few grams of depleted uranium and natural thorium in January 2010. Last take-off was the theory group, who started in October 2009. Resources in Uranium are scarce, if only the 235 isotope is used and wastes related to nuclear energy production are potentially dangerous. The use of fast neutrons allows to multiply existing resources in national independence, but will be based on new separation processes, that can be modelled using predictive theory. Understanding and optimizing separation in the nuclear fuel cycle is the central aim of the 'Institute for Separation Chemistry' (ICSM). Enlarging this central goal to the needs for chemistry of recycling, for instance, strategic metals crucial for alternative energy, is the natural extension surfaces of needs and development of science, with a strong link for technology and implementation. This report gives an overview of the work published and submitted by ICSM since January 2009. The nine active research teams still work in the direction of the scientific open questions as defined and published by the French academy in 2007. The report is organized by scientific topics: each of the nine active research groups gathers a community of researchers and engineers from different expertises, who publish in various domains in the corresponding journals, and who participate at different international meetings. The research teams are organized as follows: 1 - Chemistry and Physical-chemistry of the Actinides; 2 - Ions at Active Interfaces; 3 - Ionic Separation from self-assembled Molecular systems; 4 - Sono-chemistry in Complex Fluids; 5 - Nano-materials for Energy and Recycling processes

  2. Formulation and cytotoxicity evaluation of new self-emulsifying multiple W/O/W nanoemulsions

    Directory of Open Access Journals (Sweden)

    Sigward E

    2013-02-01

    Full Text Available Estelle Sigward,1 Nathalie Mignet,1 Patrice Rat,2 Mélody Dutot,2 Saleh Muhamed,1 Jean-Michel Guigner,3 Daniel Scherman,1 Denis Brossard,1 Sylvie Crauste-Manciet11Chemical, Genetic and Imaging Pharmacology Laboratory; INSERM U1022, CNRS UMR8151, Chimie ParisTech, Faculty of Pharmacy, Paris Descartes University, Sorbone Paris Cité, Paris, France; 2Chemistry-Cellular and Analytical Toxicology Laboratory (C-TAC, Faculty of Pharmacy, Paris Descartes University, Sorbone Paris Cité, Paris, France; 3Institut de Minéralogie et de Physique des Milieux Condensés IMPMC -IRD-CNRS UMR 7590, Université Paris Pierre et Marie Curie, Paris, FranceAbstract: Three multiple water-in-oil-in-water (W/O/W nanoemulsions have been designed for potential inclusion of either lipophilic or hydrophilic drugs using a two-step emulsification process exclusively based on low-energy self-emulsification. The W/O primary emulsion was constituted by a blend of oil (medium chain triglyceride, a mixture (7:3 of two surfactants, and a 10% water phase. The surfactants were a mixture of Polysorbate-85/Labrasol®, Polysorbate-85/ Cremophor® EL or glycerol/Polysorbate-85. The final W/O/W nanoemulsions were obtained by the addition of water, with a weight ratio nanoemulsion/water of 1:2. The multiple emulsion stability was found to increase from 24 hours to 2 and 6 months with Labrasol, glycerol, and Cremophor, respectively. Cytotoxicity was found for formulations including Labrasol and Cremophor EL. The concentration of emulsion inhibiting 50% cell viability (IC50 was determined using the alamarBlue® test, giving after 24 hours of incubation, IC50 = 10.2 mg/mL for the Labrasol formulation and IC50 = 11.8 mg/mL for the Cremophor EL formulation. Corresponding calculated IC50 values for surfactants were 0.51 mg/mL for Labrasol and 0.59 mg/mL for Cremophor EL. In both cases, cytotoxicity was due to an apoptotic mechanism, evidenced by chromatin condensation and P2X7 cell death

  3. Atmospheric anthropic impacts tracked by the French atmospheric mobile observatory

    Science.gov (United States)

    Cuesta, J.; Chazette, P.; Flamant, P. H.

    2009-04-01

    A new ATmospheric Mobile ObServatory, so called "ATMOS", has been developed by the LiMAG "Lidar, Meteorology and Geophysics" team of the Institut Pierre Simon Laplace (IPSL) in France, in order to contribute to international field campaigns for studying atmospheric physico-chemistry, air quality and climate (i.e. aerosols, clouds, trace gazes, atmospheric dynamics and energy budget) and the ground-based validation of satellite observations. ATMOS has been deployed in the framework of i) LISAIR, for monitoring air quality in Paris in 2005, ii) AMMA "African Monsoon Multidisciplinary Analysis", in Tamanrasset and in Niamey for observing the aerosols and the atmospheric boundary layer in the Sahara and in the Sahel in 2006, iii) COPS "Convectively and Orographycally driven Precipitation Study" in the Rhin Valley in 2007 and iv) the validation of the spatial mission CALIPSO, launched in April 2006. In the coming years, ATMOS will be deployed i) in the Paris Megacity, in the framework of MEGAPOLI (2009-2010), ii) in southern France (near Marseille) for the Chemistry-Aerosol Mediterranean Experiment CHARMEX (2011-2012) and iii) the validation of ADM-Aeolus in 2010-2011 and Earth-Care in 2012. ATMOS payload is modular, accounting for the different platforms, instruments and measuring techniques. The deployment of ATMOS is an essential contribution to field campaigns, complementing the fixed sites, and a potential alternative of airborne platforms, heavier and more expensive. ATMOS mobile payload comprises both the remote sensing platform MOBILIS ("Moyens mOBIles de téLédetection de l'IPSL") and the in-situ physico-chemical station SAMMO ("Station Aérosols et chiMie MObile"). MOBILIS is an autonomous and high-performance system constituted by a full set of active and passive remote sensing instrumentation (i.e. Lidars and radiometers), whose payload may be adapted for either i) long term fixed monitoring in a maritime container or a shelter, ii) ground-based transect

  4. Beyond the Compositional Threshold of Nanoparticle-Based Materials.

    Science.gov (United States)

    Portehault, David; Delacroix, Simon; Gouget, Guillaume; Grosjean, Rémi; Chan-Chang, Tsou-Hsi-Camille

    2018-04-17

    , great promise. We will span methods of low temperature "chimie douce" aqueous synthesis coupled to microwave heating, sol-gel chemistry and processing coupled to solid state reactions, and then molten salt synthesis. These protocols pave the way to metastable low valence oxyhydroxides, vanadates, perovskite oxides, boron carbon nitrides, and metal borides, all obtained at the nanoscale with structural and morphological features differing from "usual" nanomaterials. These nano-objects show original properties, from sensing, thermoelectricity, charge and spin transports, photoluminescence, and catalysis, which require advanced characterization of surface states. We then identify future trends of synthetic methodologies that will merit further attention in this burgeoning field, by emphasizing the importance of unveiling reaction mechanisms and coupling experiments with modeling.

  5. Metallorganic routes to nanoscale iron and titanium oxide particles encapsulated in mesoporous alumina: formation, physical properties, and chemical reactivity.

    Science.gov (United States)

    Schneider, J J; Czap, N; Hagen, J; Engstler, J; Ensling, J; Gütlich, P; Reinoehl, U; Bertagnolli, H; Luis, F; de Jongh, L J; Wark, M; Grubert, G; Hornyak, G L; Zanoni, R

    2000-12-01

    Iron and titanium oxide nanoparticles have been synthesized in parallel mesopores of alumina by a novel organometallic "chimie douce" approach that uses bis(toluene)iron(0) (1) and bis(toluene)titanium(0) (2) as precursors. These complexes are molecular sources of iron and titanium in a zerovalent atomic state. In the case of 1, core shell iron/iron oxide particles with a strong magnetic coupling between both components, as revealed by magnetic measurements, are formed. Mössbauer data reveal superparamagnetic particle behavior with a distinct particle size distribution that confirms the magnetic measurements. The dependence of the Mössbauer spectra on temperature and particle size is explained by the influence of superparamagnetic relaxation effects. The coexistence of a paramagnetic doublet and a magnetically split component in the spectra is further explained by a distribution in particle size. From Mössbauer parameters the oxide phase can be identified as low-crystallinity ferrihydrite oxide. In agreement with quantum size effects observed in UV-visible studies, TEM measurements determine the size of the particles in the range 5-8 nm. The particles are mainly arranged alongside the pore walls of the alumina template. TiO2 nanoparticles are formed by depositing 2 in mesoporous alumina template. This produces metallic Ti, which is subsequently oxidized to TiO2 (anatase) within the alumina pores. UV-visible studies show a strong quantum confinement effect for these particles. From UV-visible investigations the particle size is determined to be around 2 nm. XPS analysis of the iron- and titania- embedded nanoparticles reveal the presence of Fe2O3 and TiO2 according to experimental binding energies and the experimental line shapes. Ti4+ and Fe3+ are the only oxidation states of the particles which can be determined by this technique. Hydrogen reduction of the iron/iron-oxide nanoparticles at 500 degrees C under flowing H2/N2 produces a catalyst, which is active

  6. The extended family of hexagonal molybdenum oxide

    Energy Technology Data Exchange (ETDEWEB)

    Hartl, Monika [Los Alamos National Laboratory; Daemen, Luke [Los Alamos National Laboratory; Lunk, J H [NON LANL; Hartl, H [NON LANL; Frisk, A T [NON LANL; Shendervich, I [NON LANL; Mauder, D [NON LANL; Feist, M [NON LANL; Eckelt, R [NON LANL

    2009-01-01

    Over the last 40 years, a large number of isostructural compounds in the system MoO{sub 3}-NH{sub 3}-H{sub 2}O have been published. The reported molecular formulae of 'hexagonal molybdenum oxide' (HEMO) varied from MoO{sub 3}, MoO{sub 3} {center_dot} 0.33NH{sub 3}, MoO{sub 3} {center_dot} nH{sub 2}O (0.09 {le} n {le} 0.69) to MoO{sub 3} {center_dot} mNH{sub 3} {center_dot} nH{sub 2}O (0.09 {le} m {le} 0.20; 0.18 {le} n {le} 0.60). Samples, prepared by the acidification route, were investigated using thermal analysis coupled on-line to a mass spectrometer for evolved gas analysis; X-ray powder diffraction; Fourier Transform Infrared, Raman and Magic-Angle-Spinning {sup 1}H-NMR spectroscopy; Incoherent Inelastic Neutron Scattering. The X-ray study of a selected monocrystal confirmed the presence of the well-known framework of edge-sharing MoO{sub 6} octahedra: Space group P6{sub 3}/m, a = 10.527(1), c =3.7245(7) {angstrom}, {gamma} = 120{sup o}. The structure of the synthesized samples can best be described by the structural formula (NH{sub 4})[Mo{sub x}{open_square}{sub 1/2+p/2}(O{sub 3x + 1/2-p/2})(OH){sub p}] {center_dot} yH{sub 2}O (x 5.9-7.1; p {approx} 0.1; y = 1.2-2.6), which is consistent with the existence of one vacancy for 12-15 molybdenum sites. The 'chimie douce' reaction of MoO{sub 3} {center_dot} 0.155NH{sub 3} {center_dot} 0.440H{sub 2}O with a 1:1 mixture of NO/NO{sub 2} at 100 C resulted in the synthesis of MoO{sub 3} {center_dot} 0.539H{sub 2}O. Tailored nano-sized molybdenum powders can be produced using HEMO as precursor.

  7. ICOM2012: 3rd International Conference on the Physics of Optical Materials and Devices (Belgrade, Serbia, 2-6 September 2012)

    Science.gov (United States)

    Dramićanin, Miroslav D.; Antić, Željka; Viana, Bruno

    2013-11-01

    The 3rd International Conference on the Physics of Optical Materials and Devices (ICOM2012) was held in Belgrade (Serbia) from 2 to 6 September 2012 (figure 1). The conference was organized by the Vinča Institute of Nuclear Sciences, University of Belgrade (Serbia) and the Laboratoire de Chimie de la Matière Condensée de Paris (France), and supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia and Optical Society of America. ICOM2012 was a follow-up to the two previous, successful ICOM conferences held in Herceg Novi in 2006 and 2009. The conference aimed at providing a forum for scientists in optical materials to debate on: • Luminescent materials and nanomaterials • Hybrid optical materials (organic/inorganic) • Characterization techniques of optical materials • Luminescence mechanisms and energy transfers • Theory and modeling of optical processes • Ultrafast-laser processing of materials • Optical sensors • Medical imaging • Advanced optical materials in photovoltaics and biophotonics • Photothermal and photoacoustic spectroscopy and phenomena The conference stressed the value of a fundamental scientific understanding of optical materials. A particular accent was put on wide band-gap materials in crystalline, glass and nanocrystalline forms. The applications mainly involved lasers, scintillators and phosphors. Rare earth and transition metal ions introduced as dopants in various hosts were considered, and their impact on the optical properties were detailed in several presentations. This volume contains selected contributions of speakers and participants of the ICOM2012 conference. The conference provided a unique opportunity for about 200 scientists from 32 countries to discuss recent progress in the field of optical materials. During the three and half days, 21 invited talks and 52 contributed lectures were given, with a special event in memory of our dear colleague Professor Dr Tsoltan

  8. The First SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-1)

    Science.gov (United States)

    Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Claustre, Herve; Ras, Josephine; VanHeukelem, Laurie; Berthon, Jean-Francois; Targa, Cristina; vanderLinde, Dirk; Barlow, Ray; Sessions, Heather

    2001-01-01

    Four laboratories, which had contributed to various aspects of SeaWiFS calibration and validation activities, participated in the first SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-1): Horn Point Laboratory (USA), the Joint Research Centre (Italy), the Laboratoire de Physique et Chimie Marines (France), and the Marine and Coastal Management group (South Africa). The analyses of the data are presented in Chapter 1 and the individual methods of the four groups are presented in Chapters 2-5. The average (or overall) conclusions of the round-robin are derived from 12 in situ stations occupied during a cruise in the Mediterranean Sea, although, only 11 stations are used in the analyses. The data set is composed of 12 replicates taken during each sampling opportunity with 3 replicates going to each of the 4 laboratories. The average (or overall) results from the intercomparison of 15 pigments or pigment associations are as follows (in some cases, data subsets that exclude pigments which were not analyzed by all the laboratories, or that had unusually large variances, are used to exclude a variety of problematic pigments): a) the accuracy of the four methods in determining the concentration of total chlorophyll a is 7.9%, (one method did not separate mono- and divinyl chlorophyll a, and if the samples containing significant divinyl chlorophyll a concentrations are ignored, the four methods have an accuracy of 6.7%); b) the accuracy in determining the full set of pigments is 19.1%; c) there is a reduction in accuracy of approximately - 12.2% for every decade (factor of 10) decrease in concentration (based on a data subset); d) the precision of the four methods using a subset data is 8.617( 6.2% for an edited subset); e) the repeatability of the four methods using the subset data is 9.2% (7.2%; for an edited subset, and f) the reproducibility of the four methods using the subset data is 21.31% (15.0% for an edited subset).

  9. Solubility of radionuclides in a bentonite environment for provisional safety analyses for SGT-E2

    International Nuclear Information System (INIS)

    Berner, U.

    2014-08-01

    Within stage 2 of the sectoral plan for deep geological repositories for radioactive waste in Switzerland provisional safety analyses are carried out. In the case of the repository for spent fuel and vitrified high level waste considered, retention mechanisms include the concentration limits of safety relevant elements in the pore water of the buffer material (bentonite). The present work describes the solubility limits of the safety relevant elements Be, C_i_n_o_r_g, Cl, K, Ca, Co, Ni, Se, Sr, Zr, Nb, Mo, Tc, Pd, Ag, Sn, I, Cs, Sm, Eu, Ho, Pb, Po, Ra, Ac, Th, Pa, U, Np, Pu, Am and Cm in the pore water of bentonite after diffusive solution exchange with the host rock Opalinus Clay. The term solubility limit denotes the maximum amount of an element dissolving in the pore solution of the considered chemical reference system. Chemical equilibrium thermodynamics is the classical tool used for quantifying such considerations. For a given solid phase equilibrium thermodynamics predict the amount of substance dissolving in the solution and describe the speciation of the considered element in solution. The principles of chemical equilibrium will also be the primary work hypothesis in the present work. Solubility calculations were performed with the most recent version of GEMS/PSI (GEMS3.2 v.890) using the PSI/Nagra Chemical Thermodynamic Data Base 12/07, which is an update of the former Nagra/PSI Chemical Thermodynamic Data Base 01/01. The database was complemented with datasets from the ThermoChimie v. 7b for elements that were not considered in the mentioned update (Ag, Co, Sm, Ho, Pa, Be), with data from Iupac (Pb) and with data from the literature (Mo). Differing sources for thermodynamic data are noted. Reference values as well as lower and upper guideline values are evaluated. For many formation constants of solids and solutes uncertainties are known and allow conveying lower and upper guideline values. In many cases it is not clear whether the most stable solid is

  10. Observed and modelled “chemical weather” during ESCOMPTE

    Science.gov (United States)

    Dufour, A.; Amodei, M.; Ancellet, G.; Peuch, V.-H.

    2005-03-01

    The new MOdèle de Chimie Atmosphérique à Grande Echelle (MOCAGE) three-dimensional multiscale chemistry and transport model (CTM) has been applied to study heavy pollution episodes observed during the ESCOMPTE experiment. The model considers the troposphere and lower stratosphere, and allows the possibility of zooming from the planetary scale down to the regional scale over limited area subdomains. Like this, it generates its own time-dependent chemical boundary conditions in the vertical and in the horizontal. This paper focuses on the evaluation and quantification of uncertainties related to chemical and transport modelling during two intensive observing periods, IOP2 and IOP4 (June 20-26 and July 10-14, 2001, respectively). Simulations are compared to the database of four-dimensional observations, which includes ground-based sites and aircraft measurements, radiosoundings, and quasi-continuous measurements of ozone by LIDARs. Thereby, the observed and modelled day-to-day variabilities in air composition both at the surface and in the vertical have been assessed. Then, three sensitivity studies are conducted concerning boundary conditions, accuracy of the emission dataset, and representation of chemistry. Firstly, to go further in the analysis of chemical boundary conditions, results from the standard grid nesting set-up and altered configurations, relying on climatologies, are compared. Along with other recent studies, this work advocates the systematic coupling of limited-area models with global CTMs, even for regional air quality studies or forecasts. Next, we evaluate the benefits of using the detailed high-resolution emissions inventory of ESCOMPTE: improvements are noticeable both on ozone reactivity and on the concentrations of various species of the ozone photochemical cycle especially primary ones. Finally, we provide some insights on the comparison of two simulations differing only by the parameterisation of chemistry and using two state

  11. Impact of two chemistry mechanisms fully coupled with mesoscale model on the atmospheric pollutants distribution

    Science.gov (United States)

    Arteta, J.; Cautenet, S.; Taghavi, M.; Audiffren, N.

    Air quality models (AQM) consist of many modules (meteorology, emission, chemistry, deposition), and in some conditions such as: vicinity of clouds or aerosols plumes, complex local circulations (mountains, sea breezes), fully coupled models (online method) are necessary. In order to study the impact of lumped chemical mechanisms in AQM simulations, we examine the ability of both different chemical mechanisms: (i) simplified: Condensed Version of the MOdèle de Chimie Atmosphérique 2.2 (CV-MOCA2.2), and (ii) reference: Regional Atmospheric Chemistry Model (RACM), which are coupled online with the Regional Atmospheric Modeling Systems (RAMS) model, on the distribution of pollutants. During the ESCOMPTE experiment (Expérience sur Site pour COntraindre les Modèles de Pollution et de Transport d'Emissions) conducted over Southern France (including urban and industrial zones), Intensive observation periods (IOP) characterized by various meteorological and mixed chemical conditions are simulated. For both configurations of modeling, numerical results are compared with surface measurements (75 stations) for primary (NO x) and secondary (O 3) species. We point out the impact of the two different chemical mechanisms on the production of species involved in the oxidizing capacity such as ozone and radicals within urban and industrial areas. We highlight that both chemical mechanisms produce very similar results for the main pollutants (NO x and O 3) in three-dimensional (3D) distribution, despite large discrepancies in 0D modeling. For ozone concentration, we found sometimes small differences (5-10 ppb) between the mechanisms under study according to the cases (polluted or not). The relative difference between the two mechanisms over the whole domain is only -7% for ozone from CV-MOCA 2.2 versus RACM. When the order of magnitude is needed rather than an accurate estimate, a reduced mechanism is satisfactory. It has the advantage of running faster (four times less than CPU

  12. Study of air pollution in urban and peri-urban area during the Escompte campaign using meso-scale modeling. Impact of dynamics and emission inventories; Etude de la pollution en zone urbaine et peri-urbaine a l'aide d'une modelisation meso-echelle durant la campagne Escompte. Impact de la dynamique et des inventaires d'emission

    Energy Technology Data Exchange (ETDEWEB)

    Taghavi, S.M.

    2003-11-01

    This work involves the study of the redistribution of photochemical species over urban and peri-urban areas during the ESCOMTE campaign over southern France. This region includes Marseilles, an urban area close to the industrial zone of Fos-Berre, one of the most polluted sites in Europe. The comprehensive R AMS model, version 4.3, coupled on-line with a chemical module including 29 species (MOCA2.2) is used in parallel code. The efficiency of coupling is checked using Amdahl's law (1967). The percentage of parallelization is 96% for the RAMS model and increases to 98% for RAMS-Chimie. A number of sensitivity tests were performed to obtain realistic meteorological fields. In this work, the heterogeneity of the ground humidity depends on the surface texture, and the topography option accurately retrieves the location of mountaintops and valleys. To avoid bias in the chemical results, the meteorological simulation is first validated with surface data, Lidar, Sodar, soundings and airborne measurements for three IOPs (Intensive Observation Periods) which ave contrasting meteorological conditions. Secondly, the redistribution of chemical modeled species (CO, NO{sub x}, SO{sub 2}, O{sub 3}) is validated with surface, aircraft and Lidar data over this region where the circulation is complex (sea breeze associated with northern (Mistral) or southern flow). Use of two way nested grids resolves the problem of lateral boundaries for chemical fields (Taghavi et al, 2004). The location of convective cells and the channelling of Rhone and Durance depend on direction of synoptic flow and play a role in the redistribution of pollutants and their chemical regime. Two emission inventories of varying quality (30% difference in average) are compared (Taghavi et al, 2004), one with a high resolution (I km) and the other with an average resolution. In both cases, ozone plume location and concentration are the same, and thus we conclude a low resolution inventory is satisfactory to

  13. Le recours aux modeles dans l'enseignement de la biologie au secondaire : Conceptions d'enseignantes et d'enseignants et modes d'utilisation

    Science.gov (United States)

    Varlet, Madeleine

    Le recours aux modeles et a la modelisation est mentionne dans la documentation scientifique comme un moyen de favoriser la mise en oeuvre de pratiques d'enseignement-apprentissage constructivistes pour pallier les difficultes d'apprentissage en sciences. L'etude prealable du rapport des enseignantes et des enseignants aux modeles et a la modelisation est alors pertinente pour comprendre leurs pratiques d'enseignement et identifier des elements dont la prise en compte dans les formations initiale et disciplinaire peut contribuer au developpement d'un enseignement constructiviste des sciences. Plusieurs recherches ont porte sur ces conceptions sans faire de distinction selon les matieres enseignees, telles la physique, la chimie ou la biologie, alors que les modeles ne sont pas forcement utilises ou compris de la meme maniere dans ces differentes disciplines. Notre recherche s'est interessee aux conceptions d'enseignantes et d'enseignants de biologie au secondaire au sujet des modeles scientifiques, de quelques formes de representations de ces modeles ainsi que de leurs modes d'utilisation en classe. Les resultats, que nous avons obtenus au moyen d'une serie d'entrevues semi-dirigees, indiquent que globalement leurs conceptions au sujet des modeles sont compatibles avec celle scientifiquement admise, mais varient quant aux formes de representations des modeles. L'examen de ces conceptions temoigne d'une connaissance limitee des modeles et variable selon la matiere enseignee. Le niveau d'etudes, la formation prealable, l'experience en enseignement et un possible cloisonnement des matieres pourraient expliquer les differentes conceptions identifiees. En outre, des difficultes temporelles, conceptuelles et techniques peuvent freiner leurs tentatives de modelisation avec les eleves. Toutefois, nos resultats accreditent l'hypothese que les conceptions des enseignantes et des enseignants eux-memes au sujet des modeles, de leurs formes de representation et de leur approche

  14. Numerical and experimental study of the influence of the operational parameters on the formation mechanisms of oxides of nitrogen during the combustion of mixtures of cellulosic and plastic materials; Etude experimentale et numerique de l'influence des parametres operatoires sur les mecanismes de formation des oxydes d'azote lors de la combustion de melanges de materiaux cellulosiques et plastiques

    Energy Technology Data Exchange (ETDEWEB)

    Andzi Barhe, T.

    2004-10-15

    The current thesis was performed within a collaboration between the Laboratoire de Combustion et de Detonique (LCD of the University of Poitiers) and the Laboratoire de Physique et de Chimie d'Environnement (LPCE) of the University of Ouagadougou. It was financed by Agency for Environment and Energy Management (ADEME). The principle object of this study is the optimisation of the combustion process during the incineration of waste. This optimisation is aimed at the reduction of the polluting emissions, principally CO and NO, during the incineration of cellulosic and plastic materials. It involves the analysis of the influence of the operational parameters on the polluting emissions and the control of reaction mechanisms of formation and reduction of these pollutants during the combustion process. Consequently, the study was performed in two parts: an experimental part and a numerical part. The experimental part was realised using a fixed bed counterflow reactor. This setup simulates the combustion within an industrial waste incinerator. The reactor allows the combustion of a vertical layer of waste mixture (wood, cardboard, PET, polyamide) to be followed. Three model mixtures representative of the makeup of household waste were studied in order to determine the influence of the composition of the waste on the emission of pollutants (CO and NO). The obtained results show that this parameter has a practically negligible influence within the tested parameter range. Consequently the formation of pollutants depends on the operating parameters - the equivalence ratio and the temperature. A numerical study of the influence of these parameters in order to show their impact on the mechanisms of pollutant formation and to determine the chemical mechanisms involved in the formation of oxides of nitrogen. The numerical study was performed with software developed at the LCD. This programme based on a detailed chemical model coupled to a simple physical model. It uses the

  15. 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

  16. Thermodynamic properties of hydrated cement phases: C-S-H, C-A-S-H and M-S-H

    International Nuclear Information System (INIS)

    Roosz, Cedric

    2016-01-01

    Concrete is one of the most widely used building materials in the world. Durability, mechanical and chemical properties have made it a material of choice in storage concepts proposed by the French National Agency for Radioactive Waste Management (Andra), including the achievement of retaining structures, cell plugs, massive supports or conditioning waste. The study of the stability of the constituent phases of cementitious materials is needed in view of the planned quantities and the durability of the structures, and must consider (i) temperature ranges suitable for cement matrices containment in contact with exothermic waste (25-80 deg. C), and (ii) a representative time scale of the lifetime of the storage. The Andra ThermoChimie project therefore aims to develop a consistent thermodynamic database, to model the chemical evolution of cement materials in the environment of radioactive waste. However, in the present state, the database offers only thermodynamic data of cementitious crystalline phases, as well as a limited data set of three different chemical compositions for nano-crystalline C-S-H. This does not allow to reproduce the degradation of cementitious materials, or model the degradation of the new formulations, such as 'Low pH' concretes. The objective is therefore to acquire a thermodynamic complementary data set on phases such as C-S-H (Calcium Silicate Hydrates) C-A-S-H (Calcium Aluminate Silicate Hydrates) and M-S-H (Magnesium Silicate Hydrates), to complete the ThermoChimie database. This study is based on experimental, analytical and digital work, in order to obtain a set of thermodynamic data (Δ f G 0 , Δ f H 0 , Cp(T), S 0 ) sufficiently representative of the chemical variability of these phases. Finally, this set of data allows the development of a thermodynamic predictive model in extended spaces of compositions and temperatures. Development of this predictive model requires (i) The acquisition of thermodynamic properties on

  17. Chemical properties of some elements in a molten lithium chloride, potassium chloride eutectic (1962); Proprietes chimiques de quelques elements dans l'eutectique chlorure de lithium-chlorure de potassium fondu (1962)

    Energy Technology Data Exchange (ETDEWEB)

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

    1961-12-15

    of this type between two elements. We give the diagrams of uranium and sulphur as examples. The chemical properties of sulphur show that the dismutation phenomenon operates also in molten media reactions, thus emphasising the resemblance with aqueous solutions. Finally, we show briefly how it is possible to predict qualitatively the chemical properties of a given element in a molten solvent other than the LiCl-KCl eutectic. (author) [French] Le developpement de l'utilisation des milieux fondus notamment en chimie preparative et pour certaines applications technologiques, a pose le probleme de la connaissance des proprietes chimiques des elements dans ces solvants. Les etudes de structure des solutions fondues font etat de l'existence d'especes connues en solution aqueuse, telles que les ions et les complexes. Ce fait et d'autre part quelques travaux portant sur l'etude de reactions chimiques en milieu fondu, nous ont amene a etablir une comparaison entre ces milieux et les solutions aqueuses. Nous nous sommes proposes de montrer que l'on retrouve dans ces milieux les phenomenes fondamentaux de la chimie des solutions aqueuses, permettant de prevoir et d'interpreter les reactions. Les proprietes chimiques du vanadium, de l'uranium et du soufre dans l'eutectique LiCl-KCl fondu a 480 deg. C, nous ont servi d'exemple. Le premier probleme est l'identification des divers degres d'oxydation de ces elements existant dans le solvant choisi. Nous avons tente de le resoudre par la comparaison des spectres d'absorption obtenus en solution aqueuse et dans l'eutectique fondu. Nous discutons les possibilites de cette methode dans un chapitre consacre a la spectrophotometrie d'absorption dans l'eutectique LiCl-KCl. Au cours de l'etude des proprietes chimiques, nous insistons sur les moyens mis en oeuvre pour deplacer les equilibres: formation de complexes, variation des proprietes oxydo-reductrices avec la formation de complexes L'attention est plus particulierement portee sur les

  18. Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analyses of contaminated soils by XRF

    Science.gov (United States)

    Mucke, D.

    2012-04-01

    Heavy-metal contamination of soils in Saxony/Germany by foundry fumes and low-cost rapid analysis of contaminated soils by XRF Dieter Mucke, Rolf Kumann, Sebastian Baldauf GEOMONTAN Gesellschaft für Geologie und Bergbau mbH&Co.KG, Muldentalstrasse 56, 09603 Rothenfurth, Saxony/Germany For hundreds of years in the Ore Mountains between Bohemia and Saxony silver and other ores are produced and smelted. Sulphide- and sulpharsenide-ores needed to be roasted first. In doing so the sulphide sulphur was oxidised under formation of sulphur dioxide SO2 and arsenide conversed into elemental arsenic and arsenide trioxide As2O3 respectively. Also the metals lead, cadmium and zinc are components of hut smokes, in the field of nickel foundries also nickel. The contents of soils basically reflect the geogenic conditions, which are caused by decomposition- and relocation-effects of the mineralisations, in the area of foundries also with influences by with the hut smokes anthropogenic mobilised elements. The Saxonian Agency for Environment and Geology drafted in 1992 a Soil Investigation Program with the aim of investigation of the contamination of Saxonian soils with arsenic and toxic heavy metals. In order of this Agency GEOMONTAN investigated 1164 measuring points in the grid 4 * 4 km.soil profiles and extracted soil samples for analysis. In the result of the laboratory examinations the Agency edited the "Soil atlas of the Free State of Saxony". 27 elements, pH and PAK are shown in detailed maps and allow in whole Saxony the first assessment of the contamination of soils with arsenic and toxic heavy metals. Each of the investigated soil profiles represent an area of 16 km2. Already by the different use of the districts (agricultural, industrial, urban) restricts representative values. GEOMONTAN in the meantime used at the exploration of a copper deposit in Brandenburg/Germany with approx. 50,000 single tests at drill cores a very fast low-cost method: the X Ray fluorescence

  19. Geothermal prospection in the Greater Geneva Basin (Switzerland and France): Architecture of the new Information System

    Science.gov (United States)

    Favre, Stéphanie; Brentini, Maud; Giuliani, Gregory; Lehmann, Anthony

    2017-04-01

    objectives and needs are similar. Concerning the architecture, the data model was developed according to the following themes: geology, hydrogeology, geophysics and geothermal energy. Each theme contains features that are characterized by a geometric shape (point, line or polygon), attribute tables and relations. The data model was designed to allow crossed requests between features though unique identifier (ID) attributes. PostgreSQL, an open-source database management system, was chosen to ensure a wide range of compatible GIS tools. This solution helps keeping the link between 2D and 3D geological data, especially through the cantonal platform (ge.ch/sitg/geologie3d) that stores and displays 3D models. To ensure the development of a geological IS, these aspects have been considered: 1) having a robust and scalable architecture 2) selecting adapted IT tools and 3) defining coherent data workflows. The future system should be able to answer queries to produce of maps, models and define protection zones, which assist an optimal management of the subsurface resources for the State of Geneva. REFERENCES Blunier, P., Tacher, L. and Parriaux, A. 2007: Systemic Approach of Urban Underground Resources Exploitation. 11th ACUUS Conference: Underground Space: Expanding the Frontiers. Athens , Greece. Brentini, M. and Favre, S. 2014: Développement d'une base de données du sous-sol dans le cadre de GEothermie 2020: intégration des forages et lignes sismiques à Genève. Internship thesis, University of Geneva, 90p. Clerc, N., Rusillon, E., Cardello, L., Moscariello, A. and Renard, P., 2016. Structural Modeling of the Geneva Basin for Geothermal Ressource Assessment. Abstract, 14th Swiss Geoscience Meeting, Geneva, Switzerland. Gabriel, P., Gietzel, J., Le, H., H., and Schaeben, H. 2015: GST: A Network Based Datastore for Geoscience Data and Geomodels and Its Implementation - ProMine's Contribution Towards Interoperability. Springer International Publishing Switzerland, 59

  20. Ausbildung und Erwartungshaltung

    Science.gov (United States)

    Knoke, Holger

    1997-09-01

    werden Geologiestudenten zeitgemäß ausgebildet? Wird in der Angewandten Geologie das gelehrt, was in Wirtschaftsunternehmen an Wissen von einem Geologen erwartet wird? Erfolgt die spezielle Ausbildung zum Hydrogeologen fundiert und umfassend? Eine Antwort auf diese Fragen kann sicherlich nicht allumfassend gegeben werden, da sie von der jeweiligen Sichtweise abhängig ist. Ein Geologieprofessor wird die Ausbildung seiner Studenten im Großen und Ganzen als zeitgemäß einstufen, eventuell hier und da Verbesserungen für möglich halten. Auffällig ist die hohe Anzahl der in den letzten Jahren bereits geänderten oder zur Änderung anstehenden Studienordnungen. Es zeigt, daß die Straffung des Studiums sowie eine zumindest teilweise neue Wichtung der Schwerpunkte notwendig war bzw. ist, wobei im allgemeinen eine höhere Stundenzahl in den Grundlagenfächern Mathematik, Physik und Chemie angesetzt wird. Betrachtet man die Gesamtstundenzahlen der alten und der reformierten Studienordnungen, kann jedoch von einer Kürzung der Pflichtstunden in den meisten Fällen nicht die Rede sein. Eine grundlegende Reform des Geologiestudiums ist zur Zeit nicht zu erkennen, eher eine Verschulung des Studienganges. Die Entwicklung scheint zur Zeit weg von der freien Kurswahl und hin zu Modulangeboten mit vorgegebenen Kursen und Reihenfolgen zu gehen. Für die Hydrogeologie-Professoren ist es sicherlich nicht einfach zu entscheiden und in ihrem Kollegenkreis durchzusetzen, was aus dem generellen geowissenschaftlichen Kursangebot für einen Hydrogeologen notwendig oder aber entbehrlich ist. Genügen die Grundlagen der Paläontologie und der Mineralogie? Kann man ganz darauf verzichten? Was erwarten Behörden und Wirtschaftsunternehmen an allgemeinen und Spezialkenntnissen? Geologische Landesämter z. B. wollen, pauschal betrachtet, Geologen alten Stils. Ist ausdrücklich ein Angewandter Geologe oder speziell ein Hydrogeologe erwünscht, soll dieser die Spezialkenntnisse zus

  1. A Paradigm shift to an Old Scheme for Outgoing Longwave Radiation

    Science.gov (United States)

    McDonald, Alastair B.

    2016-04-01

    nérales Sur Les Températures Du Globe Terrestre Et Des Espaces Planétaires.' Annales de Chimie et de Physique 27: 136-67, translated by Raymond T. Pierrehumbert http://www.nature.com/nature/journal/v432/n7018/extref/432677a-s1.pdf Philipona, Rolf, Bruno Dürr, Atsumu Ohmura, and Christian Ruckstuhl. 2005. 'Anthropogenic Greenhouse Forcing and Strong Water Vapor Feedback Increase Temperature in Europe'. Geophysical Research Letters 32 (19): L19809. doi:10.1029/2005GL023624. Saussure, Horace-Benedict de. 1786. 'Chapter XXXV. Des Causes du Froid qui Regne sur les Montagnes'. In Voyages dans les Alpes, II:347-71. Neuchatel: Fauche-Borel. http://gallica.bnf.fr/ark:/12148/bpt6k1029499.r=.langFR, translated by Alastair B. McDonald, http://www.abmcdonald.freeserve.co.uk/saussure/CHAPTER%2035.pdf. Thorne, Peter W., Philip Brohan, Holly A. Titchner, et al. 2011. 'A Quantification of Uncertainties in Historical Tropical Tropospheric Temperature Trends from Radiosondes'. Journal of Geophysical Research: Atmospheres 116 (D12): n/a - n/a. doi:10.1029/2010JD015487. Wild, Martin, Doris Folini, Christoph Schär, et al. 2013. 'The Global Energy Balance from a Surface Perspective'. Climate Dynamics 40 (11-12): 3107-34. doi:10.1007/s00382-012-1569-8. White, James W.C., Alley, Richard B., Archer, David E., et al. 2013. Abrupt Impacts of Climate Change: Anticipating Surprises. Washington, D.C.: National Academies Press. http://www.nap.edu/catalog/18373.

  2. [Lecturers in chemistry at the Medical Faculty of the University of Nagyszombat].

    Science.gov (United States)

    Szabadváry, F; Vámos, E

    1994-01-01

    After a short introduction on the development of the medieval universities at Pécs, Obuda, and Pozsony, and mentioning those who lectured in medicine in Hungary, the authors emphasise that modern chemistry was born during the 16th and 17th century. They stress the role of Paracelsus who invented iatro-chemistry, and that the first independent chairs, were founded in Germany in the beginning of 17th century at Altdorf, Marburg, Jéna, but were followed suit by Paris, when the Jardin des Plantes were erected. The first chemical textbook, the Cours de Chimie (Paris 1665), was also the work of a Frenchman, namely Nicolas Lémery (1645-1715). From the 18th century chemistry was also included in the curriculum of medical education in Hungary. Among the chairs of the newly founded medical faculty at Nagyszombat we find the chemical-botanical department in 1769. Its first professor was an Austrian physician Jakab Winterl (1773-1809), who had been a head physician at Selmecbánya, in Northern Hungary. Owing to a rash and premature publication Winterl's international reputation was unfortunately undermined in the last century by a leading German science historian, Hermann Kopp. The authors stress, however, that Winterl indeed played an important role in organizing the chemical department, and purchasing all the necessary equipment needed for up to date researches and analyses. And above all, in his Prolusiones ad chemiam saeculi decimi noni, he foresaw many forthcoming paths and discoveries of 19th century chemistry. After Winterl's retirement the department was divided into two parts. Pál Kitaibel (1757-1817) led the botanica department and János schuster (1777-1838) the other one for chemistry. Kitaibel made a name for himself by depicting Hungarian flora, but he also made discoveries in chemistry. He discovered chlore lime, before Tennant in 1795, a material which might have been used for whitening textiles. Schuster, on the other hand, introduced a system of Hungarian

  3. Evaluation d'une approche pedagogique respectant les facons d'apprendre des filles en sciences et en TIC en 9e annee au Nouveau-Brunswick

    Science.gov (United States)

    Lirette-Pitre, Nicole T.

    2009-07-01

    La reussite scolaire des filles les amene de plus en plus a poursuivre une formation postsecondaire et a exercer des professions qui demandent un haut niveau de connaissances et d'expertise scientifique. Toutefois, les filles demeurent toujours tres peu nombreuses a envisager une carriere en sciences (chimie et physique), en ingenierie ou en TIC (technologie d'information et de la communication), soit une carriere reliee a la nouvelle economie. Pour plusieurs filles, les sciences et les TIC ne sont pas des matieres scolaires qu'elles trouvent interessantes meme si elles y reussissent tres bien. Ces filles admettent que leurs experiences d'apprentissage en sciences et en TIC ne leur ont pas permis de developper un interet ni de se sentir confiante en leurs habiletes a reussir dans ces matieres. Par consequent, peu de filles choisissent de poursuivre leurs etudes postsecondaires dans ces disciplines. La theorie sociocognitive du choix carriere a ete choisie comme modele theorique pour mieux comprendre quelles variables entrent en jeu lorsque les filles choisissent leur carriere. Notre etude a pour objet la conception et l'evaluation de l'efficacite d'un materiel pedagogique concu specifiquement pour ameliorer les experiences d'apprentissage en sciences et en TIC des filles de 9e annee au Nouveau-Brunswick. L'approche pedagogique privilegiee dans notre materiel a mis en oeuvre des strategies pedagogiques issues des meilleures pratiques que nous avons identifiees et qui visaient particulierement l'augmentation du sentiment d'auto-efficacite et de l'interet des filles pour ces disciplines. Ce materiel disponible par Internet a l'adresse http://www.umoncton.ca/lirettn/scientic est directement en lien avec le programme d'etudes en sciences de la nature de 9e annee du Nouveau-Brunswick. L'evaluation de l'efficacite de notre materiel pedagogique a ete faite selon deux grandes etapes methodologiques: 1) l'evaluation de l'utilisabilite et de la convivialite du materiel et 2

  4. Recent Developments in the Theory of Mechanisms in Radiation Chemical Processes; Developpements recents dans la theorie des mecanismes des reactions radiochimiques; Poslednie dostizheniya v teorii mekhanizmov radiatsionno-khimicheski kh protsessov; Adelantos recientes en la interpretacion teorica del mecanismo de los procesos radioquimicos

    Energy Technology Data Exchange (ETDEWEB)

    Roberts, R. [U.K.A.E.A., Wantage Research Laboratory, Berks (United Kingdom)

    1963-11-15

    Recent developments in the mechanisms of radiation-initiated chemical reactions are reviewed. The role of ion molecule processes is reviewed, with particular reference to the radiation chemistry of methane. In this system, the existence of reactions of excited molecules, in addition to ionic processes is deduced. It is shown that, in the radiolysis of methane, unsaturated hydrocarbons play a considerable part in the mechanism of reaction. Developments in ionic polymerization and also polymerization under heterogenous conditions are reviewed. The importance of reactant purity, and also cleanliness of reaction vessels is discussed. The effect of an applied external potential in solid state polymerization is briefly reviewed. The importance of free-radical processes to radiation chemists is considered in the light of the Dow process for the production of ethyl bromide. (author) [French] L'auteur examine les resultats recents obtenus dans l'etude des mecanismes des reactions chimiques radio-induites. Il etudie l'importance des reactions ion-molecule, en considerant tout particulierement la radio-chimie due methane. Il en deduit qu'il existe dans ce systeme, outre les phenomenes ioniques, des reactions de molecules excitees. il montre que les hydrocarbures non satures jouent un role considerable dans la radiolyse du methane. Il passe en revue les resultats obtenus dans la polymerisation ionique ainsi que dans la polymerisation dans des conditions heterogenes. Il insiste sur l'importance de la purete des reactifs ainsi que sur la proprete des recipients. En meme temps, il examine brievement l'effet d'un potentiel exterieur sur la polymerisation a l'etat solide. Il signale l'importance radiochimique des reactions fondees sur des radicaux liebre, libres sous l'angle du procede Dow pour la production de bromure d'ethyle. (author) [Spanish] El autor examina los recientes progresos realizados en el estudio de los mecanismos de las reacciones quimicas radioinducidas. Sedala la

  5. Tritium Labelling by Means of Uranium Hydride; Marquage au Tritium au Moyen d'Hydrure d'Uranium; 0414 0435 0447 ; Marcacion con Tritio por Medio de Hidruro de Uranio

    Energy Technology Data Exchange (ETDEWEB)

    Felter, R. E.; Currie, L. A. [Pennsylvania State University, University Park, PA (United States)

    1962-02-15

    A new and efficient method for introducing tritium into organic molecules has been observed. Labelling is accomplished by exposure of the organic vapour to heated uranium tritide. In experiments with n-pentane and with ethylene, the principal labelled products were the tritiated parent molecules. The rates of tritium incorporation varied from about 0.2 to 10.0% (of initial tritium) per hour. The mechanism of the reaction has been demonstrated to be not a result of radiation chemistry, but rather a direct reaction of hydrogen atoms from the surface with the hydrocarbon. In addition to the rapid labelling with a significant fraction of the tritium present, the method has another unique advantage : tritium which has not reacted with the organic vapour may be removed from the gas phase simply by cooling the reaction vessel to room temperature. (author) [French] Les auteurs ont mis au point une methode nouvelle et efficace pour introduire le tritium dans les molecules de substances organiques. Le marquage est realise par exposition de la substance organique sous forme de vapeur au tritide Bullet d'uranium chauffe. Dans des experiences avec le n-pe.ntane et l'ethylene, les principaux produits marques ont ete les molecules meres tritiees. Le taux d'incorporation du tritium a varie d'environ 0,2 a 10% (de la quantite initiale de tritium) par heure. On a demontre que le mecanisme de la reaction n'est pas un effet de la chimie des rayonnements, mais plutot une reaction directe des atomes d'hydrogene de la surface avec l'hydrocarbure. Outre qu'une partie importante du tritium utilise reagit rapidement, la methode presente un avantage exceptionnel : on peut aisement separer le tritium qui n'a pas reagi de la substance organique, Bullet en ramenant simplement a la temperature ambiante le recipient dans lequel la reaction a eu lieu. (author) [Spanish] La memoria describe un nuevo procedimiento muy eficaz para introducir tritio en moleculas organicas. La marcacion se consigue

  6. "Hexagonal molybdenum trioxide"--known for 100 years and still a fount of new discoveries.

    Science.gov (United States)

    Lunk, Hans-Joachim; Hartl, Hans; Hartl, Monika A; Fait, Martin J G; Shenderovich, Ilya G; Feist, Michael; Frisk, Timothy A; Daemen, Luke L; Mauder, Daniel; Eckelt, Reinhard; Gurinov, Andrey A

    2010-10-18

    ]+ cations and H2O. The “chimie douce” reaction of MoO3·0.155NH3·0.440H2O with a 1:1 mixture of NO/NO2 at 100 °C resulted in the synthesis of MoO3·0.539H2O. This material is of great interest as a host of various molecules and cations.

  7. Hybrid Materials Based on Magnetic Layered Double Hydroxides: A Molecular Perspective.

    Science.gov (United States)

    Abellán, Gonzalo; Martí-Gastaldo, Carlos; Ribera, Antonio; Coronado, Eugenio

    2015-06-16

    Design of functional hybrids lies at the very core of synthetic chemistry as it has enabled the development of an unlimited number of solids displaying unprecedented or even improved properties built upon the association at the molecular level of quite disparate components by chemical design. Multifunctional hybrids are a particularly appealing case among hybrid organic/inorganic materials. Here, chemical knowledge is used to deploy molecular components bearing different functionalities within a single solid so that these properties can coexist or event interact leading to unprecedented phenomena. From a molecular perspective, this can be done either by controlled assembly of organic/inorganic molecular tectons into an extended architecture of hybrid nature or by intercalation of organic moieties within the empty channels or interlamellar space offered by inorganic solids with three-dimensional (MOFs, zeolites, and mesoporous hosts) or layered structures (phosphates, silicates, metal dichalcogenides, or anionic clays). This Account specifically illustrates the use of layered double hydroxides (LDHs) in the preparation of magnetic hybrids, in line with the development of soft inorganic chemistry processes (also called "Chimie Douce"), which has significantly contributed to boost the preparation hybrid materials based on solid-state hosts and subsequent development of applications. Several features sustain the importance of LDHs in this context. Their magnetism can be manipulated at a molecular level by adequate choice of constituting metals and interlayer separation for tuning the nature and extent of magnetic interactions across and between planes. They display unparalleled versatility in accommodating a broad range of anionic species in their interlamellar space that encompasses not only simple anions but chemical systems of increasing dimensionality and functionalities. Their swelling characteristics allow for their exfoliation in organic solvents with high

  8. Compositional Tuning, Crystal Growth, and Magnetic Properties of Iron Phosphate Oxide

    Science.gov (United States)

    Tarne, Michael

    as determined from the magnitude of the magnetic propagation vector. This trend can be qualitatively reproduced by increasing the ratio of J2/ J1 in the Heisenberg model. Intriguingly, the domain size extracted from peak broadening of the magnetic reflections is nearly equal to the pitch length for each value of x, which suggests that the two qualities are linked in this unusual antiferromagnet. The last chapter focuses on the oxyfluoride Fe3PO7-x Fx. Through fluorination using low-temperature chimie douce reactions with polytetrafluoroethylene, the magnetic properties show changes in the magnetic susceptibility, isothermal magnetization, and neutron powder diffraction. The magnetic susceptibility shows a peak near T = 13 K and a zero field cooled/field cooled splitting at T = 78 K. The broad, flat-topped magnetic reflections in the powder neutron diffraction exhibit a decrease in width and increase in intensity. The changes in the neutron powder diffraction suggest an increase in correlation length in the ab plane of the fluorinated compound. Iron phosphate oxide is a unique lattice showing a rich magnetic phase diagram in both the gallium-substituted and fluorinated species. While mean-field interactions are sufficient to describe interactions in the solid solution series Fe3-xGaxPO4O3, the additional magnetic transitions in Fe3PO7-xFx suggest a more complicated set of interactions.

  9. Identification and estimation ot carbohydrates using radioisotopic methods; Identification et dosage des hydrates de carbone a l'aide des radioisotopes; Identifikatsiya i opredelenie karbogidratov s pomoshch'yu radioizotopnykh metodov; Identificacion u valoracion de hidratos de carbono con ayuda de radioisotopos

    Energy Technology Data Exchange (ETDEWEB)

    Phillips, G O; Criddle, W J [Department of Chemistry, University College, Cardiff (United Kingdom)

    1962-01-15

    Isotope-dilution methods have been developed to identify and estimate the small amount of products formed when carbohydrates are irradiated in aqueous solution with Co{sup 60} gamma-radiation. Conventional analytical methods proved inadequate. After irradiation of C{sup 14}-sugar solutions, the autoradiographs prepared after paper chromatography indicated extensive degradation. Using a reverse isotope-dilution procedure involving the addition of known carriers, and conversion of the fragments into crystalline derivatives, various constituents were quantitatively determined. It is possible to distinguish between d- and Z-isomers, and estimate each isomer independently. The method is applicable to other analytical problems in carbohydrate chemistry. A new method for scanning and recording the radioactivity along paper-chromatogram strips, which involves an inexpensive modification to conventional counting equipment, is described. (author) [French] On a mis au point des methodes de dilution isotopique destinees a identifier et a doser les menues quantites de produits qui se forment lorsque des hydrates de carbone en solution aqueuse sont irradies par les rayons gamma du cobalt-60. A cet egard, les methodes d'analyse classiques se sont revelees inadequates. Apres irradiation de solutions de sucre marque au carbone-14, les autoradiogrammes etablis a la suite d'une chromatographic sur papier indiquaient une forte degradation. En recourant a une methode de dilution isotopique inverse, avec adjonction d'entraineurs connus, et en operant une conversion des fragments en derives cristallins, on a pu determiner quantitativement plusieurs elements constitutifs. Il est possible de distinguer les isomeres dextrogyres des isomeres levogyres et de doser chaque isomere independamment. La methode peut etre appliquee a d'autres problemes d'analyse dans la chimie des hydrates de carbone. Le memoire decrit une nouvelle methode permettant d'explorer et d'enregistrer la radioactivite de

  10. Savoirs mondains, savoirs savants : les femmes et leurs cabinets de curiosités au siècle des Lumières

    Directory of Open Access Journals (Sweden)

    Adeline Gargam

    2010-01-01

    Full Text Available Dans la France des Lumières, la culture de la curiosité est un phénomène de mode mais surtout un jeu social et intellectuel. La présente étude entend retracer l’histoire d’une trentaine de cabinets féminins de curiosité tenus à cette époque. Des femmes fortunées de l’aristocratie et de la bourgeoisie parisienne et provinciale ont alors constitué sous l’emprise de leur libido sciendi des cabinets d’alchimie, de minéralogie, de physique‑chimie, d’histoire naturelle et d’anatomie naturelle et artificielle. Ces cabinets obéissent à une typologie particulière. Il en existe deux catégories : les cabinets d’amateurs, constitués pour la parade et le spectacle des visiteurs et fonctionnant comme de véritables écoles de plaisirs intellectuels et éducatifs ; les cabinets à finalité scientifique et didactique, formés par des savantes expérimentées qui se livrent dans leurs laboratoires à des recherches personnelles et expérimentales au nom des progrès de la science médicale et de l’instruction publique. La réflexion porte aussi sur le fonctionnement de ces cabinets privés de curiosité, particulièrement sur leur mode de constitution, leur décor intérieur ainsi que sur le contenu des collections qui nécessitaient certaines techniques d’organisation, d’acquisition et de conservation communes à celles de leurs homologues masculins.During the Enlightenment in France, curiosity culture constituted both a fashion and an intellectual and social game.  This article explores thirty cabinets of  curiosities run by women during this period. Wealthy women from the Parisiain and provincial aristocracy and middle classes organized cabinets in alchemy, mineralogy, physics and chemistry, natural history and biology studies. These cabinets can be divided into two distinct categories. The first represented amateur interests; they were developed for show and served as schools for intellectual and

  11. PREFACE: Preface

    Science.gov (United States)

    Audoin, Bertrand; Dehoux, Thomas; Guillet, Yannick

    2011-02-01

    and the gala dinner took place in a wine chateau in the medieval village. We hope this experience will remain in the attendees' memories as a pleasant and convivial time. We would like to express our thanks to the members of the organizing committee, the scientific committee, and all our generous sponsors, either institutions or companies, for their help in making this event possible. We would also like to thank the scientists involved for their confidence in our organization, and for their contributions. As unanimously decided by the attendees, the next symposium will be held in Japan, most likely in 2012. The papers published in this volume of the Journal of Physics: Conference Series provide a collection of state-of-the-art and recent advances in research and applications of laser ultrasonics as presented at this second Symposium. Bertrand Audoin - Conference ChairThomas Dehoux - Conference proceedings co-editorYannick Guillet - Conference proceedings co-editor Conference photograph Scientific committee Bertrand AudoinUniversité Bordeaux 1, France Alain BlouinNRC, Canada Christ GlorieuxKatholieke Universiteit Leuven, Belgium Vitalyi GusevUniversité du Maine, France Peter HessUniversity of Heidelberg, Germany Alexander A KarabutovMoscow State University, Russia Sridhar KrishnaswamyNorthwestern University, USA Humphrey MarisBrown University, USA Jean-Pierre MonchalinNRC, Canada Todd MurrayBoston University, USA Makoto OchiaiToshiba Corp, Japan Menglu QianTongji University, China Daniel RoyerEcole Supérieure de Physique et de Chimie, France Hervé TrétoutDassault Aviation, France Hubert VoillaumeEADS, France Oliver B WrightHokkaido University, Japan Shu-yi ZhangNanjing University, China Organizing committee Bertrand AudoinChair Sandrine GuitLocal administrator Christophe Aristégui Thomas Dehoux Evelyne Dewayse Yannick Guillet Armelle Guilloux

  12. Improvement of A.E.S System, using a 188Re-radiolabeled hapten

    International Nuclear Information System (INIS)

    Morandeau, L.

    2002-01-01

    ENSCR (Ecole Nationale Superieure de Chimie de Rennes). For the dithiocarbamates family, the complexation of rhenium or technetium leads to a nitrido complex . Two molecules of dithiocarbamates are involved in the complexation. Studies of dithiobenzoates at the macroscopic scale show that three molecules of chelating agent ensure the complexation of the rhenium as illustrated. Two methods can be investigated to obtain this new therapeutic tool: the coupling of the hapten with the chelating agent followed by the radiolabelling, and the radiolabelling of the chelating agent followed by the coupling with the hapten. Further, this new Re-188 hapten will be tested in vitro to check its immunoreactivity towards the antibody-679 (anti-HSG) and its stability in serum media. According to these preliminary results, biodistribution studies on rats and on the sheep model, should be then investigated. This project relies on a FAIR programm which involves a collaboration between several partners from France and Australia. The hapten has been synthesised in France, at INSERM (Institut National pour la Sante et la Recherche Medicale, Nantes) and Chelatec (Company supplying Chelating agents and vector technology, Nantes). In Australia, the organic chemistry work (coupling the hapten and the chelating agent) occurs in Murdoch University (Perth). The radionuclides are supplied by ANSTO (Australian Nuclear Science and Technology Organisation, Sydney) and the work of radiochemistry and biodistribution studies takes place in Fremantle hospital

  13. Modelling of primary aerosols in the chemical transport model MOCAGE: development and evaluation of aerosol physical parameterizations

    Directory of Open Access Journals (Sweden)

    B. Sič

    2015-02-01

    Full Text Available This paper deals with recent improvements to the global chemical transport model of Météo-France MOCAGE (Modèle de Chimie Atmosphérique à Grande Echelle that consists of updates to different aerosol parameterizations. MOCAGE only contains primary aerosol species: desert dust, sea salt, black carbon, organic carbon, and also volcanic ash in the case of large volcanic eruptions. We introduced important changes to the aerosol parameterization concerning emissions, wet deposition and sedimentation. For the emissions, size distribution and wind calculations are modified for desert dust aerosols, and a surface sea temperature dependant source function is introduced for sea salt aerosols. Wet deposition is modified toward a more physically realistic representation by introducing re-evaporation of falling rain and snowfall scavenging and by changing the in-cloud scavenging scheme along with calculations of precipitation cloud cover and rain properties. The sedimentation scheme update includes changes regarding the stability and viscosity calculations. Independent data from satellites (MODIS, SEVIRI, the ground (AERONET, EMEP, and a model inter-comparison project (AeroCom are compared with MOCAGE simulations and show that the introduced changes brought a significant improvement on aerosol representation, properties and global distribution. Emitted quantities of desert dust and sea salt, as well their lifetimes, moved closer towards values of AeroCom estimates and the multi-model average. When comparing the model simulations with MODIS aerosol optical depth (AOD observations over the oceans, the updated model configuration shows a decrease in the modified normalized mean bias (MNMB; from 0.42 to 0.10 and a better correlation (from 0.06 to 0.32 in terms of the geographical distribution and the temporal variability. The updates corrected a strong positive MNMB in the sea salt representation at high latitudes (from 0.65 to 0.16, and a negative MNMB in

  14. Effets néfastes sur la stabilité des solutions polyacrylamides utilisées dans la récupération assistée du pétrole Harmful Effects of Formaldehyde on the Stability of Polyacrylamide Solutions Used in Enhanced Oil Recovery

    Directory of Open Access Journals (Sweden)

    Catherin G.

    2006-11-01

    Full Text Available L'étude de la dégradation oxydante des polyacrylamides (PAA et HPAA en solution aqueuse nous a permis de trouver que du formaldéhyde est produit par l'oxydation de l'acrylamide résiduel. Du formaldéhyde est aussi produit par l'oxydation du méthanol résiduel quand ce non-solvant a été utilisé pour purifier les PAA et HPAA par précipitation de leurs solutions aqueuses. Ce formaldéhyde est responsable de la formation de dérivés insolubles nuisibles pour les propriétés rhéologiques utiles des solutions. Ce résultat rejoint ceux d'études antérieures où un effet comparable a été observé après addition de formaldéhyde aux solutions de PAA et HPAA. Mais l'examen de la littérature relative à la chimie du formaldéhyde montre que les réactions d'oxydation et d'addition qui ont été suggérées pour rendre compte de cet effet sont inadéquates dans le milieu considéré. Le schéma que nous proposons explique mieux les phénomènes observés. Nous avons aussi montré que l'oxydo-réduction du formaldéhyde est responsable de la formation de radicaux libres sur les polyacrylamides. II était alors possible de conclure, sans avoir recours à d'autres expériences, que le formaldéhyde ne doit pas être utilisé dans la récupération assistée du pétrole pour protéger les solutions des polyacrylamides contre la biodégradation. In a study of the oxidation of aqueous solutions of the polyacrylamides PAA and HPAA, we have found that formaldehyde is an oxidation product both of acrylamide residual in the commercial polymers and of the methanol residual in polymers purified by methanol precipitation from aqueous solutions. The presence of formaldehyde in turn causes the production of insoluble derivatives which spoil the rheological properties of polymer solutions. This result reinforces those of previous studies where a similar effect was observed after formaldehyde was added to solutions of PAA and HPAA. Examination of the

  15. Technical Note: Validation of Odin/SMR limb observations of ozone, comparisons with OSIRIS, POAM III, ground-based and balloon-borne instruments

    Directory of Open Access Journals (Sweden)

    F. Jégou

    2008-06-01

    Full Text Available The Odin satellite carries two instruments capable of determining stratospheric ozone profiles by limb sounding: the Sub-Millimetre Radiometer (SMR and the UV-visible spectrograph of the OSIRIS (Optical Spectrograph and InfraRed Imager System instrument. A large number of ozone profiles measurements were performed during six years from November 2001 to present. This ozone dataset is here used to make quantitative comparisons with satellite measurements in order to assess the quality of the Odin/SMR ozone measurements. In a first step, we compare Swedish SMR retrievals version 2.1, French SMR ozone retrievals version 222 (both from the 501.8 GHz band, and the OSIRIS retrievals version 3.0, with the operational version 4.0 ozone product from POAM III (Polar Ozone Atmospheric Measurement. In a second step, we refine the Odin/SMR validation by comparisons with ground-based instruments and balloon-borne observations. We use observations carried out within the framework of the Network for Detection of Atmospheric Composition Change (NDACC and balloon flight missions conducted by the Canadian Space Agency (CSA, the Laboratoire de Physique et de Chimie de l'{}Environnement (LPCE, Orléans, France, and the Service d'Aéronomie (SA, Paris, France. Coincidence criteria were 5° in latitude×10° in longitude, and 5 h in time in Odin/POAM III comparisons, 12 h in Odin/NDACC comparisons, and 72 h in Odin/balloons comparisons. An agreement is found with the POAM III experiment (10–60 km within −0.3±0.2 ppmv (bias±standard deviation for SMR (v222, v2.1 and within −0.5±0.2 ppmv for OSIRIS (v3.0. Odin ozone mixing ratio products are systematically slightly lower than the POAM III data and show an ozone maximum lower by 1–5 km in altitude. The comparisons with the NDACC data (10–34 km for ozonesonde, 10–50 km for lidar, 10–60 for microwave instruments yield a good agreement within −0.15±0.3 ppmv for the SMR data and −0.3±0.3 ppmv

  16. The development of the Middle Triassic tectonical controlled Germanic Basin of Central Europe and the palaeoenvironmental related distribution of marine and terrestrial reptiles

    Science.gov (United States)

    Diedrich, Cajus G.

    2010-05-01

    comparison to convergent developed sirenia. Palaeogeography, Palaeoclimatology, Palaeoecology, (in review). Diedrich, 2010b. The vertebrate fauna of the Lower Ladinian (Middle Triassic) from Lamerden (Germany) and contribution to the palaeoecology, anatomy and palaeogeography of the Germanic Basin reptiles. Palaeogeography, Palaeoclimatology, Palaeoecology, (in review). Diedrich, 2010c. The palaeogeographic reconstructions of the Middle Triassic tectonical controlled carbonatic Germanic Basin of Central Europe - a northern Tethys connected cratonic marine Basin - coastal basin margin mappings by the use of reptile footprint rich intertidal and sabkha environments. Abstract, Fifth International Conference on the Geology of the Tethys Realm, Quena-Luxor,Egypt), 3-5. Diedrich, in prep. The shallow marine fish and sauropterygian reptile vertebrate fauna of the Germanic Basin from the atavus/pulcher Bonebeds in the Bad Sulza Fm (Illyrian, Middle Triassic) of Bad Sulza (Central Germany). Diedrich, C. and Trostheide, F. 2007. Auf den Spuren der terresten Muschelkalksaurier und aquatischen Sauropterygier vom obersten Röt bis zum Mittleren Muschelkalk (Unter-/Mitteltrias) von Sachsen-Anhalt. Abhandlungen und Berichte für Naturkunde, 30, 5-56. Föhlisch, K. 2007. Überlieferungen seismischer Aktivität im Unteren Muschelkalk. Beiträge zur Geologie Thüringens, N.F. 14, 55-83. Furrer, H. 1995. The Kalkschieferzone (Upper Meride estone Ladinian) near Meride (Canton Ticino, Southern Switzerland) and the evolution of a Middle Triassic intraplatform basin. Eclogae geolicae Helvetiae, 88(3), 827-852. Hagdorn, H. 1990. Das Muschelkalk/Keuper-Bonebed von Crailsheim. In: Weidert, W. K. (Ed.), Klassische Fundstellen der Paläontologie, Band 2. 78-88. Goldschneck-Verlag, Stuttgart. Hagdorn, H., E. Nitsch, Aigner, T. and Simon, T. 2009. Field guide 6th international Triassic field workshop (Pan-European Correlation of the Triassic) Triassic of Southwest Germany. September 7-11, 2009, www

  17. Editorial

    Directory of Open Access Journals (Sweden)

    José Yvan Pereira Leite

    2010-11-01

    Santa Cruz. C’est une initiative qui veut mettre en valeur la diffusion scientifique liée à l’intériorisation des Instituts Federaux dans tout le Brésil. La publication de la revue au Campus Santa Cruz du IFRN représente le compromis de l’Institution avec le développement centré sur la diffusion scientifique de cet important réseau d’Éducation, Sciences et Technologie. Dans ce context la HOLOS gagne l’intérieur brésilien et le monde, du fait que ses éditions s’elargissent par l’indexation au Directory of Open Access Journals (www.doaj.org, une plateforme d’accès ouvert au monde. La lecture peut être regroupée pour les intéressés aux thèmes concernant l’environnement qui dissertent sur: l’utilisation des décharges sanitaires pour la réduction de l’émission des gas à effet de serre; le SIG comme matériel d’étude pour la prévention des innondations due aux pluies; la sécurité chimique des logements; et les activités liées a l’élevage de crevettes. Ces articles font converger société et academie et présentent des alternatives aux problèmes discutés. Il est possible aussi d’ouvrir des discutions sur les thèmes d’ingénierie comme: l’évaluation des propriétés thermophysiques des liquides pour réfrigération , l’analyse de performance des huiles biodégradable en comparaison avec les huiles minérales; ou encore l’analyse d’un brûleur commercial infrarouge adapté á un éjecteur et la vérification de leurs niveaux d'émission de polluants. Dans le domaine de l’enseignement les articles présentés traitent spécifiquement de l’enseignement de la phisyque et de la chimie pour l’éducation professionnelle. Dans le domaine de la chimie organique, les thèmes socio-scientifiques mettent l’accent sur la Science, la Technologie et la Societé. Dans l’enseignement de la physique, deux travaux sont presentés: l’”experimentothèque” comme alternative à l’enseignement au lycée et l

  18. Conception et calibration d'un sonoreacteur pour l'oxydation de la cellulose par le systeme TEMPO/NaOCl/NaBr

    Science.gov (United States)

    Paquin, Michel

    Avec le contexte economique actuel dans le domaine des pates et papiers au Canada, l'industrie se doit de diversifier ses produits mis en marche. La fermeture de plus de 20 usines depuis 2005, une baisse du PIB de l'industrie de 1,4 milliard CAD entre 1999--2008, une baisse de la demande de 2,4 %, une diminution du prix de la pate de 20,9 % depuis juillet 2009. La delocalisation du secteur vers l'Asie et l'hemisphere sud sont autant de raisons pour laquelle l'industrie se doit d'etre a l'avant plan de nouvelle technologie a base de fibre de bois. Pour augmenter leur rentabilite, l'industrie se doit de diversifier ses produits dans d'autres secteurs que le simple fabricant de papier impression-ecriture. Sa diversification passe par l'elaboration de nouveaux papiers a valeur ajoutee (papier conducteur, papier bioactif, etc.), par l'utilisation de la biomasse forestiere pour la production d'energie, par l'utilisation de la biomasse forestiere pour l'elaboration d'une plateforme de chimie verte, par l'utilisation de la lignine pour le developpement de polymeres et par l'utilisation de la fibre cellulosique pour la fabrication de nanomateriaux. La fabrication de nanofibrille de cellulose peut devenir un des produits qui servira a diversifier la production des usines de pates et papiers. Les nanofibrilles de cellulose possedent des proprietes mecaniques et chimiques exceptionnelles. Les nanofibrilles de cellulose sont fabriquees a partir d'une oxydation selective de la pate kraft de feuillu avec le systeme TEMPO-NaOCl-NaBr. L'oxydation selective de l'alcool primaire en C6 du monomere de glucose sous forme de carboxylates engendre une modification chimique de la cellulose qui accroit l'hydrophilicite des fibrilles. Suite a cette oxydation, nous devons effectuer une desintegration mecanique de la fibre kraft de feuillu oxydee pour separer les fibrilles. Le processus d'oxydation de la fibre par le systeme TEMPO-NaOCl-NaBr et sa defibrillation par la suite engendre une

  19. The Ranero Hydrothermal Dolomites (Albian, Karrantza Valley, Northwest Spain: Implications on Conceptual Dolomite Models Les dolomies hydrothermales de Ranero (Albien, vallée de la Karrantza, nord-ouest de l’Espagne : conséquences sur les modèles génétiques

    Directory of Open Access Journals (Sweden)

    Nader F.H.

    2012-02-01

    gisement, la pétrographie, la géochimie et certaines caractéristiques pétrophysiques des corps dolomitiques associées aux failles dans la zone de Ranero (vallée de la Karrantza, nord-ouest de l’Espagne sont présentées dans cette étude. Les corps dolomitiques sont encaissés dans des carbonates de plateforme déposés durant l’Albien dans le Bassin Basque-Cantabrique. Les dolomies sont formées au cours d’épisodes hydrothermaux successifs par remplacement ou précipitation – dans les vides laissés par une karstification superficielle et hypogène – et sont étroitement associées à un ensemble de failles et de fractures. La formation des dolomies est précédée et suivie par des dépôts de calcite hydrothermale. L’étude minéralogique et géochimique (XRD, ICP-MS/OES, XRF, isotopes stables et Sr radiogénique permet de distinguer plusieurs stades de formation. Les dolomies sont ferreuses (au début ou non-ferreuses (plus tard. Elles sont presque stoechiométriques et présentent une gamme de compositions isotopiques appauvries en δ18O (–18,7 à –10,5 ‰ V-PDB qui témoigne de la multiplicité des stades de dolomitisation et de la température élevée des fluides (150-200 °C. La formation de ces dolomies est précédée et suivie par des stylolithisations conformes à la stratification, ce qui suggère un âge fini-Albien des circulations. La chimie des dolomies, celle des silicates authigènes associés et les relations géométriques de remplacement conduisent à postuler l’action de deux types contrastés de fluides dolomitisants. Chacun d’eux est vraisemblablement dérivé de saumures sulfatées et/ou issues de la compaction, mais ils circulent ensuite dans des environnements lithologiques distincts (silicaté riche en Fe vs carbonaté pauvre en Fe où la réduction thermique des sulfates les fait évoluer vers des propriétés contrastées : soit vers une composition acide et ferreuse (à même de précipiter une dolomie ferreuse

  20. Recharge areas and hydrochemistry of carbonate springs issuing from Semmering Massif, Austria, based on long-term oxygen-18 and hydrochemical data evidence

    Science.gov (United States)

    Yehdegho, Beyene; Reichl, Peter

    2002-10-01

    la chimie des carbonates. La pCO2 et la concentration en HCO3- diminuent respectivement d'environ 0,22 unité log (atm) et 38,6 mg/l pour un accroissement de 100 m de l'altitude de recharge. Resumen. Se ha muestreado exhaustivamente el contenido en oxígeno-18 y la hidroquímica de los manantiales existentes en el macizo de Semmering (Austria) con el fin de caracterizar las áreas de recarga y su evolución hidroquímica. Se ha determinado el efecto altitudinal del δ18O con datos isotópicos e hidrogeológicos obtenidos en pequeños manantiales originados en rocas cristalinas que sirven como nivel de referencia; los resultados han sido de -0,27‰ por cada 100 m en la zona Morte del macizo, y de -0,21‰/100 m hacia el Sur. Aplicando estos valores, se ha calculado la altitud promedio a la que se produce su recarga. Para los manantiales de caudal elevado en materiales carbonatados, la altitud de recarga varía entre 1.100 y 1.410 m, cosa que es compatible con el marco topográfico e hidrogeológico de las rocas calizas y dolomíticas Mesozoicas propias del Austroalpino Bajo que los alimenta. La composición hidroquímica de los manantiales carbonatados está dominada por los iones calcio, magnesio, bicarbonato y sulfato. Los manantiales están casi saturados en calcita, pero subsaturados en dolomita, excepto en algunos que parecen hallarse cerca de la saturación. Como caracteriza a los suelos en regiones montañosas, la presión parcial de equilibrio del dióxido de carbono (PCO2) es baja, con valores comprendidos entre 10-3,0 y 10-2,5 atm. A largo plazo, el pH y los valores calculados de los índices de saturación en calcita (SIc) y en dolomita (SId), junto con la PCO2 en equilibrio, evidencian una fuerte estacionalidad; en cambio, las concentraciones de calcio, magnesio y bicarbonato prácticamente no varían. Integrando los resultados de δ18O y de la hidroquímica, se demuestra la variabilidad de la química de aguas subterráneas carbonatadas con respecto a la

  1. MOLDATA: a thermochemical data base for phenomenological and safety assessment studies for disposal of radioactive waste in Belgium

    International Nuclear Information System (INIS)

    Wang, L.; Salah, S.; De Soete, H.

    2010-01-01

    .CEN. The GDP is a server-client intranet application enabling the conversion and recalculation of thermodynamic data from various sources and different formats. Converting the data into an uniform format allows data to be compared and checked for consistency. Based on the defined acceptance/ consistency criteria, any data can be selected manually or automatically. Finally, the selected data are compiled into a TDB in formats applicable to geochemical computer codes The Geo-chemist's Workbench and PHREEQC, the two mostly used geochemical codes in SCK.CEN. Currently, MOLDATA includes data mainly from OECD-NEA reviews, and compilations from NAGRAPSI database, Lawrence Livermore National Laboratories, and ANDRA (ThermoChimie, v.5, unpublished data). The development and maintenance of MOLDATA continue as new data become available and new features are needed. (authors)

  2. Study of cis- and trans-uranium elements by paper chromatography and electrophoresis; Contribution a l'etude des elements cis- et trans-uraniens par chromatographie sur papier et electrophorese

    Energy Technology Data Exchange (ETDEWEB)

    Clanet, F [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-01-01

    'electrophorese, en chimie minerale, a ete etendu aux elements 90 a 96 en milieux HCl et HNO{sub 3}. Les resultats obtenus portent sur les points suivants: 1) - Caracterisation des etats de valence de Np et de Pu a l'aide de reactions colorees sur les chromatogrammes et les electrophoregrammes. L'alizarine, l'arsenazo-I et le thorin-I permettent de caracteriser la valence IV, tandis que le diphenylcarbazide est specifique de l'etat hexavalent. 2) - Chromatographie sur papier: en utilisant comme eluants des melanges a parts egales de solutions aqueuses de HCl ou de HNO{sub 3} et d'alcools (methanol, ethanol, n-butanol), les R{sub f} des elements 90 a 96 ont ete determines. Certaines conclusions relatives a leur complexation par les ions Cl{sup -} et NO{sub 3}{sup -} ont pu en etre deduites. 3) - Nous avons elabore une technique d'electrophorese sur membrane d'acetate de cellulose afin de separer les especes chargees formees par les elements 90 a 96 dans des solutions HCl et HNO{sub 3} 1 a 12 M. Les courbes de mobilite ont ete tracees. Il decoule de nos resultats que la tendance des elements consideres a former des complexes anioniques s'etablit dans l'ordre des potentiels ioniques, lorsqu'ils sont a l'etat tetravalent; cet ordre est inverse lorsqu'ils sont a la valence III. Les ions Cl{sup -} sont moins complexants que les ions NO{sub 3}{sup -} vis-a-vis de ces elements dans leur etat d'oxydation III et IV, mais on observe le phenomene inverse pour U{sup VI} et Pu{sup VI}. Enfin, la complexation des cations Pu{sup 4+} et PuO{sub 2}{sup 2+} par NO{sub 3}{sup -} suit l'ordre des potentiels ioniques mais a lieu dans l'ordre inverse s'il s'agit d'ions Cl{sup -}. 4) - Diverses applications analytiques sont envisagees: separation les uns des autres des divers elements consideres et separation des etats de valence de Np et de Pu. (auteur)

  3. Chromatographie à contre-courant simulé : développements et perspectives From Batch Elution to Simulated Countercurrent Chromatography

    Directory of Open Access Journals (Sweden)

    Hotier G.

    2006-11-01

    Full Text Available Les applications industrielles et le principe de fonctionnement du procédé de séparation en lit mobile ou en contre-courant simulé sont brièvement rappelés. La réalisation pratique de trois unités pilotes fonctionnant selon ce principe mais employant une technologie innovante est présentée. Cette mise en oeuvre particulière permet de tester par un simple changement de paramètres de contrôle toutes les configurations possibles de l'unité. Cet appareillage particulièrement souple est donc véritablement multitâche, ce qui permet en plus des applications en pétrochimie son emploi dans les domaines de la pharmacie, de la chimie fine et des bioséparations, où existe un grand nombre d'applications potentielles très différentes les unes des autres. Deux exemples de séparations réalisées à l'Institut Français du Pétrole sont succinctement présentés. La conclusion de ces essais est que la modélisation de ces procédés est indispensable pour pouvoir opérer correctement ce type d'unité. Une comparaison entre la chromatographie d'élution et cette technique de séparation ainsi que quelques propositions d'amélioration du procédé permettront au lecteur de se faire une idée sur l'extension potentielle de ce type de séparation. Distillation is and will for quite a long time remain the main separation technique in the refining, petrochemical and chemical industries. Some separations however cannot be performed by distillation when the products to be separated are subject to thermal degradation or when their boiling points are too close. Under these circumstances adsorption or chromatographic processes are interesting alternatives. In the 1960's and in the early 1970's the technology of the simulated moving bed, the UOP rotary valve and the application of these devices to separation processes were introduced by UOP. Nowadays simulated moving bedor countercurrentseparation processes may be found in the petrochemical industry

  4. Electron and Proton Transfer by the Grotthuss Mechanism in Aqueous Solution and in Biological Systems; Transfert d'Electrons et de Protons par le Mecanisme de Grotthuss en Solution Aqueuse et dans les Systemes Biologiques; Perenos ehlektronov i protonov mekhanizmom grotkhusa v vodnom rastvore i v biologicheskikh sistemakh; Transferencia Electronica y Protonica por el Mecanismo de Grotthuss en Soluciones Acuosas y en Sistemas Biologicos

    Energy Technology Data Exchange (ETDEWEB)

    Horne, R. A.; Courant, R. A.; Johnson, D. S. [Arthur D. Little, Inc. Cambridge, MA (United States)

    1965-10-15

    conduction protonique selon la concentration par une equation, fondee sur la racine cubique de la concentration extrapolee, qui contient des termes d'Arrhenius ou les energies d'activation sont celles qui ont trait a la rotation de l'eau du solvant et a la formation de ' trous 'dans cette eau. Ainsi, l'energie chimique et l'energie electrique peuvent etre transmises rapidement par le mecanisme de Grotthuss sur des distances relativement grandes. Ces processus interviennent dans divers phenomenes importants en biologie, notamment dans la contraction musculaire et la chimie des pigments respiratoires. (author) [Spanish] El intercambio electronico Fe{sup II} - Fe{sup III}, asi como ciertas reacciones de oxidorreduccion biologica lenta, implican una transferencia de electrones en virtud de un mecanismo de Grotthuss pasando por puentes agua. A este mecanismo se debe asimismo la conductividad electrica, anormalmente elevada, de las soluciones acuosas de acidos. A presion ordinaria, la etapa que determina la velocidad del mecanismo de Grotthuss es la rotacion de la molecula de H{sub 2}O, posiblemente H{sub 3}O+, y no el propio salto del proton. El mecanismo de Grotthuss se limita al agua monomerica capaz de girar 'libremente' entre los grupos de Frank-Wen en agua liquida y no se verifica en las zonas relativamente ordenadas. La relacion entre la conduccion protonica y la concentracion se puede expresar mediante una ecuacion basada en la rafz ciibica de la concentracion extrapolada y que contiene terminos de Arrhenius en los cuales las energias de activacion son las correspondientes a la rotacion y a la formacion de 'huecos' en el agua disolvente. De este modo, la energia, sea quimica o electrica, puede ser transmitida rapidamente a distancias relativamente grandes por el mecanismo de Grotthuss. Estos procesos intervienen en numerosos fenomenos de importancia biologica, entre otros, la contraccion muscular y la quimica de los pigmentos respiratorios. (author) [Russian] Reakcija

  5. The atomic energy course of the 'Institut National des Sciences et Techniques nucleaires' at the centre d'Etudes Nucleaires at Saclay; L'enseignement de genie atomique de l'Institut national des Sciences et Techniques nucleaires au Centre d'Etudes nucleaires de Saclay

    Energy Technology Data Exchange (ETDEWEB)

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

    1958-07-01

    foreign students. 8- Annexe: list of courses, practical work, pile projects drawn up by the 1957 students. (author)Fren. [French] 1- Les raisons de sa creation. L'electricite de France et l'industrie interessee par le developpement de l'Energie atomique ont demande au Commissariat a l'Energie atomique de former des ingenieurs capables d'etudier des projets de piles et de diriger leur construction. 2- Recrutement et Droits d'inscription. Les demandes d'inscription ont toujours depasse les possibilites. Cette annee, les cours sont suivis par 74 eleves permanents, dont 20 etrangers, et une centaine d'auditeurs libres. Tous les elevont deja ingenieurs ou nantis de grades universitaires eleves. Droit d'inscription: 250 000 F pour les eleves, 125 000 F pour les auditeurs. 3- Organisation de l'Enseignement. II comprend deux options: physique et chimie et dans chaque option: une centaine de conferences, une trentaine de travaux pratiques, des stages dans les services, l'etude d'un projet de reacteur par un groupe de 4 ou 5 eleves. L'ensemble occupe l'annee universitaire du 1 novembre au 14 juillet. 4- Sanction. Un examen final combinant les notes de deux epreuves theoriques, des travaux pratiques, du stage, et du projet conduit a un diplome d'ingenieur en genie atomique. Il n'est pas cree en realite de nouveaux ingenieurs; une mention nouvelle est seulement ajoutee a un diplome deja acquis. Les resultats ont toujours ete excellents. Le pourcentage des echecs est tres faible. 5- Placement des Diplomes. Ils reviennent tous dans leurs industries d'origine qui ont paye leurs salaires et les droits d'inscription en se privant de leurs services pendant les neuf mois de duree des cours. 6- Creations analogues. Un cours analogue a ete cree au Centre d'Etudes Nucleaires de Grenoble. Tandis que celui de SACLAY s'adresse plus specialement aux ingenieurs deja en fonctions, celui de Grenoble est, en principe, destine aux jeunes ingenieurs sortant des ecoles. 7- Conclusion. L

  6. Marine hydrogeology: recent accomplishments and future opportunities

    Science.gov (United States)

    Fisher, A. T.

    2005-03-01

    l'estimation des propriétés à la sub-surface des fonds marins, et des travaux complémentaires ont mis en valeur les mesures de flux, local ou global, de termes « sources » et « pertes », et des liens quantitatifs entre l'hydrogéologie, la chimie, la tectonique, la biologie, et les processus géophysiques. Cet article vise à résumer des résultats sélectionnés parmi un petit nombre d'études, et à décrire plusieurs nouvelles expériences et programmes, qui sont autant d'opportunités pour répondre aux questions fondamentales relatives aux fonds marins, posées ces dernières 20-30 années. La hidrogeología marina es una disciplina científica de amplios alcances que involucra la exploración de interacciones fluido-roca por debajo del fondo del mar. Se han llevado a cabo estudios en centros de expansión del fondo del mar, lugares en medio de una placa, y en ambientes de placa y margen continental. Aunque muchos sitios en el fondo del mar son remotos, existen aspectos de estos sistemas marinos que los hacen particularmente adaptables para análisis hidrológico. Nuevas técnicas y herramientas desarrolladas, y el establecimiento de varios programas multidisciplinarios para exploración oceanográfica, han ayudado a impulsar la hidrogeología marina hacia delante durante las ultimas décadas. La mayor parte del trabajo hidrogeológico marino se ha enfocado en la medición o estimación de propiedades hidrogeológicas dentro del subsuelo superficial, pero trabajo adicionalha enfatizado mediciones de flujos globales y locales, términos de fuente y sumidero de fluidos, y vínculos cuantitativos entre procesos hidrogeológicos, químicos, tectónicos, biológicos y geofísicos. Además de resumir resultados seleccionados de un número pequeño de estudios de caso, este artículo incluye una descripción de varios programas y experimentos nuevos que aportarán oportunidades excepcionales para dirigir preguntas hidrogeológicas fundamentales dentro del

  7. Molecular dynamics simulations of ter-pyridine and bis-triazinyl-pyridine complexes with lanthanide cations; Etude de dynamique moleculaire de complexes de la bis-triazinyl-pyridine (BTP) et de la terpyridine avec des lanthanides(3)

    Energy Technology Data Exchange (ETDEWEB)

    Guilbaud, Ph. [CEA Valrho, (DCC/DRRV/SEMP), 30 - Marcoule (France)

    2000-07-01

    The search for ligands which specifically separate actinides(III) from lanthanides(III) by liquid-liquid extraction has prompted considerable research in the Process Design and Modeling Department ('Service d'Etude et de Modelisation des Procedes'- SEMP). Ligands with soft donor atoms AS) that are able to perform this separation have already been investigated and research is currently under way to improve their performance for high acidic feeds. Theoretical chemistry research is conducted in the Theoretical and Structural Chemistry Laboratory ('Laboratoire de Chimie Theorique et Structurale') to improve our understanding of the complexation and extraction of these cations with such ligands. Theoretical studies were first carried out for the ter-pyridine (TPY) and bis-triazinyl-pyridine (BTP) ligands that display fairly good ability to separate and extract actinide(III) from lanthanide(III) ions. Molecular dynamics simulations were performed on ter-pyridine and bis-triazinyl-pyridine complexes with three lanthanide cations (La{sup 3+}, Eu{sup 3+} and Lu{sup 3+}) for vacuum and for water solutions. These calculations were carried out without counter-ions, with three nitrate (NO{sub 3}{sup -}) ions, and, in the case of ter-pyridine, with three {alpha}-bromo-caprate anions that are likely to be used experimentally as synergistic agents for the separation and extraction of An(III) from Ln(III). Molecular dynamics simulations were first performed for vacuum to evaluate the distances between nitrogen and lanthanide atoms (Ln{sup 3+},N) and intrinsic interaction energies to poly-nitrogenous ligands with or without NO{sub 3} ions, and for both ligands. The (Ln{sup 3+},N) distances decrease and the cation/ligand interaction energies increase along the La{sup 3+}, Eu{sup 3+}, Lu{sup 3+} series, with decreasing Ln(III) ion radii. The introduction of nitrate counter-ions makes the (Ln{sup 3+},N) distances slightly higher, and the TPY/Ln{sup 3+} and BTP

  8. Evaluation rapide du coût d'un investissement: méthode des modules fonctionnels Quick Evaluation of the Cost of an Investment: the Functional Module Method

    Directory of Open Access Journals (Sweden)

    Bergman J.

    2006-11-01

    Full Text Available L'application des méthodes statistiques dites d'analyse de données , à un large échantillonnage d'informations, obtenu soit directement à partir de sources de renseignements privées, soit en ayant recours à un logiciel de dimensionnement et d'estimation détaillés, a permis la mise au point d'une nouvelle méthode d'évaluation rapide du coût d'un investissement, développée sous le nom de Méthode des Modules Fonctionnels . Dans le passé, plusieurs procédures de conception dite modulaire ont déjà été élaborées. Dans le cas présent cependant, il s'agit de la première tentative connue dans le domaine d'utilisation de techniques telles que l'analyse en composantes principales, l'analyse factorielle sur tableau de distances et la régression linéaire multiple, pour développer une structure modulaire d'estimation du coût d'un investissement. Les changements apportés par rapport. à la procédure modulaire, pratiquée notamment jusqu'à présent par le Département Evaluation de l'Institut Français du Pétrole (IFP (Manuel d'évaluation économique des procédés, Editions Technip, Paris, 1976, concernent la définition et l'organisation des modules susceptibles d'être identifiés dans une installation quelconque de chimie. L'approche fonctionnelle consiste dans ce cas à partir du concept d'opération unitaire de génie chimique et non plus d'équipement par exemple, ce qui permet alors la création de modules dit fonctionnels. L'application pratique de la méthode repose sur la seule connaissance des éléments suivants : un schéma de procédé indiquant les équipements principaux; la nature des produits traités; un bilan matière au moins global, et si possible détaillé pour les lignes essentielles; les conditions opératoires moyennes. Les résultats peuvent être obtenus soit au moyen d'équations susceptibles d'être programmées sur calculatrice de poche, soit, ainsi que la présentation en est ici faite, à l

  9. The Scottish Research Reactor Centre and its Facilities for the Production and Exploitation of Short-Lived Radioisotopes; Le Réacteur de Recherche Ecossais et ses Installations pour la Production et l'Exploitation des Radioisotopes a Courte Periode; ШОТЛАНДСКИЙ ИССЛЕДОВАТЕЛЬСКИЙ РЕАКТОРНЫЙ ЦЕНТР И ЕГО ТЕХНИЧЕСКИЕ СРЕДСТВА ДЛЯ ПРОИЗВОДСТВА И ИСПОЛЬЗОВАНИЯ КОРОТКОЯИВУШХ РАДИОИЗОТОПОВ; El Centro del Reactor de Investigacion de Escocia y sus Instalaciones para la Produccion y Empleo de Radioisotopos de Periodo Corto

    Energy Technology Data Exchange (ETDEWEB)

    Ward, A. [The Royal College of Science and Technology, Glasgow, Scotland (United Kingdom)

    1963-03-15

    de cSte, qui penetre jusqu'au centre du coeur. De nombreuses gouttieres horizontales traversent la colonne thermique, la gouttiere centrale penetrant jusqu'a 2,5 cm d'un reservoir de combustible. Le reacteur est dote de toute une serie de petits laboratoires adjacents: installations de manutention et de preparation de sources de haute activite, vestiaires, ateliers d'electricite et de mecanique, chambres noires, laboratoires pour activites de l'order du microcurie, salle pour animaux, laboratoires de biologie et de chimie, salle de comptage a faible bruit de fond'amphitheatre et bibliotheque. On pense que les recherches s'etendront a de nombreuses disciplines scientifiques et technologiques; une grande partie du travail portera sur les radioisotopes a courte periode; l'auteur decrit quelques projects caracteristiques. (author) [Spanish] El centro del reactor de investigacion de Escocia se encuentra en construccion, calculandose que entrara en servicio en el verano de 1963. El reactor de tipo tanque tiene una potencia de 100 kW, es refrigerado por agua y moderado por agua y grafito; el combustible es uranio enriquecido en el isotopo sssu. Las instalaciones experimentales consisten en una gran columna termica, con tanque de agua blindado de grandes dimensiones y una instalacion de produccion de radioisotopos con tuberias de transporte neumatico. El cuerpo central es atravesado por tres tubos, la columna termica, por uno; ademas, existen varios pequenos dispositivos centrales de acceso vertical y otro dispositivo de acceso de seccion cuadrada , de 6 pulgadas, que penetra verticalmente hasta el centro del cuerpo del reactor. Muchos otros dispositivos de acceso horizontal atraviesan la columna termica, y el del centro del cuerpo penetra hasta 1 pulgada de los tanques de combustible. El centro comprendera un gran numero de locales auxiliares en los que se instalaran dispositivos para manejar y preparar fuentes de alta actividad, vestuarios, talleres electricos y mecanicos

  10. Formulation de fluxants pour bitumes à base d’esters méthyliques d’huiles végétales

    Directory of Open Access Journals (Sweden)

    Alfos Carine

    2003-09-01

    formulations, en présence de bitume, ont été testées au laboratoire d’application industrielle de la société APPIA afin de déterminer l’influence de la nature du bitume (composés asphalténiques, paraffiniques, résines sur le séchage final. Ces tests industriels n’ont pas permis de différencier les comportements des liants EMHV observés en l’absence de bitume. Ainsi l’emploi d’huiles végétales siccatives n’affecte pas significativement la remontée de consistance du liant \\; les résultats obtenus (évolution de la température de ramollissement, TBA, au cours du temps sont quasi identiques à ceux obtenus sur la formule de référence (bitume fluxé en présence de liant pétrochimique. Il semble que la siccativation du bitume soit telle, en présence d’agents siccatifs, que ce phénomène ne nous permette pas d’observer les tendances mises en évidence avec les seuls liants EMHV. Des chantiers réalisés en 2001et 2002 en Haute-Savoie, sur des voies à trafic important, ont montré que la remontée en consistance des formulations proposées pouvait convenir. Les liants EMHV pourront donc couvrir la quasi-totalité des applications. Au total, depuis 1999, plus de 15 000 tonnes de liants anhydres de répandages ont été fabriqués et utilisés avec des résultats similaires à ceux des liants classiques. Ces travaux ont été menés dans le cadre d’un programme Agrice11.1 2 AGRIculture pour la Chimie et l’Energie 1 en partenariat avec Diester Industrie et la société Appia.

  11. Biotechnologie : marchés et engagement des sociétés pétrolières Biotechnology: Markets and Commitments of Oil Companies

    Directory of Open Access Journals (Sweden)

    Torck B.

    2006-11-01

    Full Text Available L'intérêt pour les biotechnologies s'est accru à la suite du développement, après 1975, de techniques basées sur le génie génétique (rDNA, fusion. Bien que les prévisions soient difficiles dans ce domaine nouveau et en pleine expansion, le marché mondial des biotechnologies pourrait atteindre en l'an 2000, 150 milliards de dollars, dont 40 à 60 % pour les secteurs de la santé, de l'agriculture et de l'alimentation. D'autres secteurs sont également concernés, tels que l'environnement, l'énergie, la bioingénierie (bioréacteurs, enzymes immobilisées, membranes, chromatographie. . . et la chimie. D'un point de vue économique, les biotechnologies sont mieux adaptées à la production de substances à haute valeur ajoutée qu'à celle de produits de gros tonnage. Les produits qui connaissent un développement important sont les enzymes, les amino-acides, les biopolymères. . . Pour les produits de plus gros tonnage, les voies biotechnologiques se heurtent aux réalités économiques, en particulier aux prix comparatifs du pétrole et des céréales ou du sucre. Des procédés, non rentables pour l'instant, ont récemment été mis au point pour des produits tels que l'acrylamide, l'oxyde de propylène, l'hydroquinone, le nylon, le polyphénylène, les diacides. Les Etats-Unis conservent le leadership. Le Japon est sur le point de les rejoindre, tandis que le modèle européen se caractérise par les difficultés de transfert vers l'industrie. Les grandes firmes chimiques, telles que Rhône Poulenc et Impérial Chemical Industries (ICI ont déjà un long passé dans les biotechnologies mais d'autres telles que Monsanto, Du Pont, Mitsubishi. . . , s'y sont engagées récemment. Une analyse de brevets fait apparaître que les sociétés pétrolières s'y intéressent également, pour l'instant de manière moins importante. Leurs préoccupations restent traditionnelles : les polysaccharides, les enzymes immobilisées pour l

  12. Climate change and employment. A case study of Finland; Changement climatique et emploi. Cas de la Finlande

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-15

    The study has been carried out by a consortium led by the European Trade Union Confederation (ETUC) and the Social Development Agency (SDA), which includes Syndex, the Wuppertal Institute and ISTAS. It was commissioned by the European Commission, DG environment, as a contribution to improve current understanding of the relationship between climate change and employment. The study was also supported financially by seven public bodies: Ministries of Environment of Belgium, Spain, Finland, Italy, United-Kingdom; ADEME and DIAC in France. The first part of the study examines the potential consequences for employment of global warming in Europe - which has already begun and will continue. The main finding is that even moderate climate change will affect economic activity and employment in Europe, with some regions and economic sectors being particularly vulnerable. Increased warming will be likely to have very damaging consequences. The second half of the report considers the challenge for employment of the transition towards a lower CO2 European economy at the horizon 2030, in four key economic sectors: energy production, transport, steel and cement industries, construction/housing. The study considers a number of scenario for a reduction of 40% in CO2 emissions by the year 2030 and what the effects can be on European employment and skills. Case studies of eleven European countries are also analysed. This report is about Finland. [French] La Finlande est le 5e pays europeen en superficie, avec un total de 338.145 km{sup 2}, pour une population de 5,2 millions d'habitants. Le climat finlandais est le plus froid d'Europe, avec des besoins en chauffage pratiquement toute l'annee et des besoins en eclairage tres importants les mois d'hiver, en raison de la duree tres courte du jour. L'industrie est dominee par l'exploitation forestiere et le papier, ainsi que la metallurgie et la chimie, ces industries etant hautement energie-intensives. Ces

  13. Study of cis- and trans-uranium elements by paper chromatography and electrophoresis; Contribution a l'etude des elements cis- et trans-uraniens par chromatographie sur papier et electrophorese

    Energy Technology Data Exchange (ETDEWEB)

    Clanet, F. [Commissariat a l' Energie Atomique, 92 - Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-01-01

    'electrophorese, en chimie minerale, a ete etendu aux elements 90 a 96 en milieux HCl et HNO{sub 3}. Les resultats obtenus portent sur les points suivants: 1) - Caracterisation des etats de valence de Np et de Pu a l'aide de reactions colorees sur les chromatogrammes et les electrophoregrammes. L'alizarine, l'arsenazo-I et le thorin-I permettent de caracteriser la valence IV, tandis que le diphenylcarbazide est specifique de l'etat hexavalent. 2) - Chromatographie sur papier: en utilisant comme eluants des melanges a parts egales de solutions aqueuses de HCl ou de HNO{sub 3} et d'alcools (methanol, ethanol, n-butanol), les R{sub f} des elements 90 a 96 ont ete determines. Certaines conclusions relatives a leur complexation par les ions Cl{sup -} et NO{sub 3}{sup -} ont pu en etre deduites. 3) - Nous avons elabore une technique d'electrophorese sur membrane d'acetate de cellulose afin de separer les especes chargees formees par les elements 90 a 96 dans des solutions HCl et HNO{sub 3} 1 a 12 M. Les courbes de mobilite ont ete tracees. Il decoule de nos resultats que la tendance des elements consideres a former des complexes anioniques s'etablit dans l'ordre des potentiels ioniques, lorsqu'ils sont a l'etat tetravalent; cet ordre est inverse lorsqu'ils sont a la valence III. Les ions Cl{sup -} sont moins complexants que les ions NO{sub 3}{sup -} vis-a-vis de ces elements dans leur etat d'oxydation III et IV, mais on observe le phenomene inverse pour U{sup VI} et Pu{sup VI}. Enfin, la complexation des cations Pu{sup 4+} et PuO{sub 2}{sup 2+} par NO{sub 3}{sup -} suit l'ordre des potentiels ioniques mais a lieu dans l'ordre inverse s'il s'agit d'ions Cl{sup -}. 4) - Diverses applications analytiques sont envisagees: separation les uns des autres des divers elements consideres et separation des etats de valence de Np et de Pu. (auteur)

  14. A 3d Regional Scale Photochemical Air Quality Model. Application to a 3 Day Summertime Episode over Paris Un modèle photochimique 3D de qualité de l'air à l'échelle régionale. Application à un épisode de 3 jours à Paris en été

    Directory of Open Access Journals (Sweden)

    Carissimo B.

    2006-12-01

    the local monitoring network (Airparif. Cet article présente AZUR, un modèle photochimique eulérien 3D de qualité de l'air pour la simulation de la pollution de l'air dans les zones urbaines et semi-urbaines. Ce modèle suit les évolutions des espèces polluantes gazeuses émises dans l'atmosphère par les transports routiers et les sources industrielles, il prend en compte les réactions chimiques auxquelles sont soumises ces espèces pour des conditions météorologiques en évolution (photolyse, pression, température, humidité, leur transport par le vent et leur diffusion turbulente en fonction de la stabilité de l'air. Le logiciel a une structure modulaire avec plusieurs composants dédiés à des processus spécifiques : -MERCURE est un modèle météorologique à moyenne échelle pour déterminer les champs de vents, les coefficients de diffusion turbulente et d'autres paramètres météorologiques. C'est un modèle 3D à l'échelle régionale qui prend en compte les différentes configurations de sols et les zones de densité urbaine. Il comprend un système complet de paramètres physiques associés à des situations de ciel dégagé. -MIEL est un modèle d'inventaire d'émissions décrivant les flux de polluants provenant des transports automobiles et des activités domestiques ou industrielles. Ce modèle comprend un inventaire des sources mobiles basé sur des comptages de véhicules sur routes associés à des informations globales sur les flux de transports déduites de données statistiques sur la population. Il utilise des facteurs d'émission spécifiques correspondant aux flottes de véhicules et à des conditions de conduites réalistes. -MoCA est un modèle photochimique en phase gazeuse décrivant la chimie de l'ozone, des NOx, et des composés hydrocarbonés. Ce modèle, avec 83 espèces et 191 réactions, correspond à un mécanisme réduit bien adapté à des conditions variées de qualité de l'air (allant de conditions en sites urbains

  15. Low-Level {beta} and {gamma} Counting in the Region 0-10 Disintegrations Per Minute; Comptage {beta} et {gamma} d'echantillons de faible activite (0 a 10 desintegrations par minute); Izmerenie {beta}- i {gamma}-izlucheniya maloj moshchnosti (0-10 raspadov v minutu); Recuento {beta} y {gamma} de muestras de baja actividad (0 a 10 desintegraciones por minuto)

    Energy Technology Data Exchange (ETDEWEB)

    Manov, George G [Tracerlab Inc. (United States)

    1960-06-15

    niveaux de radioactivite de l'ordre de 0 a 10 desintegrations par minute devient de plus en plus utile dans la normalisation des radionuclides de meme que dans d'autres domaines scientifiques, tels que la geologie et la medicine. Ainsi le comptage de faible intensites est souvent necessaire en biologie et dans l'emploi des indicateurs, surtout lorsque l'emploi d'un niveau de rayonnement plus eleve modifierait le deroulement du mecanisme ou du processus etudie. Ces mesures portent souvent sur des echantillons ayant une activite de l% seulement de l'activite de fond normale (sans ecran). Dans d'autres cas, il faut tenir compte en outre du fait que le radionuclide a une periode tres courte. Il y a trois manieres generales d'augmenter la precision des mesures de faibles intensites: efficacite plus grand des compteurs, diminution des correc- tions necessitees par l'activite de fond et emploi de circuits electroniques plus stables et plus silencieux. Le memoire decrit des essais compares qui font ressortir les avantages relatifs que presentent trois types differents de compteurs d'anticoincidence s pour la reduction de l'activite de fond: a) compteurs 'champignons'; b) compteurs annulaires; c) domes en matiere plastique a scintillations. Il devient de plus en plus difficile d'obtenir des matieres non actives pour la construction des compteurs. L'auteur donne des indications sur la gamme d'activite des matieres que l'on peut se procurer dans le commerce. Le stockage de ces matieres, qui doivent de preference etre d'avant-guerre, devient de plus en plus necessaire. La stabilite du circuit electronique est indispensable au comptage de faible intensite, afin surtout d'eviter les impulsions parasites. Le memoire decrit un dispositif dans lequel des impulsions lentes sont mesurees, puis introduites dans l'appareillage electronique; elles passent ensuite par l'amplificateur et sont enfin defalquees du chiffre brut indique par le numerateur. D'une maniere generale, les circuits a

  16. Artificial Intelligence in the Petroleum World Une enquête sur les applications de l'Intelligence Artificielle dans le monde pétrolier

    Directory of Open Access Journals (Sweden)

    Braunschweig B. L.

    2006-11-01

    , bien que souvent de faible taille comparés à leurs équivalents dans d'autres branches de l'industrie (électricité, transport, aérospatiale, banque et finance, chimie, informatique. L'ensemble des questionnaires fournit un total de mille hommes-ans investis sur MA par les organisations interrogées. Ayant rencontré environ la moitié des intervenants du domaine géographique présenté plus haut, nous évaluons à 2-300 hommes-ans l'investissement total de l'industrie pétrolière sur des projets IA depuis dix ans, ce qui représente un budget de 2 à 3 milliards de francs 1990. Il est intéressant de mentionner que la deuxième vague de développement de systèmes à base de connaissances (que l'on commence à appeler systèmes experts de seconde génération semble s'accompagner d'une deuxième vague équivalente d'applications dans l'industrie pétrolière, non seulement en raison de ce saut méthodologique, mais aussi en relation avec la crise de la fin des années 80. Cette crise a eu des effets contrastés, ago-antagonistes, sur les équipes et les projets IA au sein des compagnies : certaines équipes furent supprimées ou fortement réduites en raison de la diminution des budgets de recherche, mais des projets démarrèrent en raison d'un nouveau besoin qui était d'exercer les mêmes activités (chercher, produire, raffiner du pétrole avec un personnel moins nombreux et moins expérimenté. Tant que le prix du baril restera proche de ou supérieur à 20 $, il y aura des gens, des machines et de l'argent disponibles pour mener des projets IA dans le monde pétrolier.

  17. Chemical response to groundwater extraction southeast of Mexico City

    Science.gov (United States)

    Huizar-Alvarez, R.; Carrillo-Rivera, J. J.; Ángeles-Serrano, G.; Hergt, T.; Cardona, A.

    procédure a été appliquée pour caractériser le système d'écoulement souterraine et sa source, les conditions hydrauliques de l'aquifère et la réponse hydraulique des puits considéré. L'analyse de cette information suggérer la présence des systèmes d'écoulement suivantes. (i) local avec18 et 19.5 °C de température, RS de 127-600 mg/L, et Na de 24-178 mg/L, (ii) intermédiaire avec une température de 20 á 22 °C, le RS de 203-940 mg/L et Na 30-370 mg/L, (iii) régional avec 300 à 700 mg/L de RS et 80 à 230 mg/L de Na, une température de 23 à 24.8 °C. Dans le premier cas, l'eau traverse des roches basaltiques, dans le deuxième, des sédiments clastiques avec matière organique de l'aquitard, dans le troisième, des roches volcaniques et calcaires. La chimie de l'eau des quelques puits et sa réponse hydraulique met en évidence l'influence de l'eau de L'aquitard, des effluents de surface et écoulement régional. La conception du régime d'écoulement obtenu, a permis reconnaître les conditions hydrauliques des puits plus correspondantes au contexte hydrogéologique, que si uniquement les données rabattement vs temps auraient été analysé La interpretación conjunta de la gráfica de prueba de bombeo, valores de temperatura y sólidos totales disueltos (STD) del agua subterránea extraída, medidos simultáneamente en campo y la composición química del agua extraída como apoyo adicional; se utilizó como un procedimiento alternativo para interpretar los datos de pruebas de bombeo. Toda esa información fue aplicada para caracterizar el sistema de flujo subterráneo y el origen de éste, las condiciones hidráulicas del acuífero y la respuesta hidráulica de los pozos de extracción. El análisis de la información indica la presencia de: (i) flujo local con temperatura de 18-19.5 °C, STD de 127-600, y Na de 24-178 mg/L (ii) flujo intermedio con temperatura de 20-22 °C, los STD y Na son de (203-940 y 30-370 mg/L), respectivamente; (iii

  18. Problems related with the power regulation of reactors by physico-chemical methods, and the behaviour of water and heavy water in nuclear reactors; Comportement de l'eau et de l'eau lourde dans les reacteurs nucleaires et problemes de la regulation de puissance par voie physico-chimique

    Energy Technology Data Exchange (ETDEWEB)

    Dolle, L; Conan, D; Dirian, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    . Comportement de l'eau lourde dans les reacteurs en exploitation. Pollution isotopique de l'eau lourde: Sa vitesse est liee au type de reacteur et a certains incidents caracteristiques. L'utilisation d'une colonne de reconcentration est un moyen efficace pour maintenir le titre de l'eau lourde dans un reacteur dont la pollution isotopique lente ne peut etre exclue. Detection des fuites d'eau lourde: Elle permet de mesurer les taux instantanes de fuites faibles, de localiser la fuite, et de controler la contamination atmospherique dans l'enceinte du reacteur. On procede par analyse isotopique du deuterium ou par dosage du tritium sur des echantillons d'eau de condensation. Pollution chimique et epuration de l'eau lourde: La pollution chimique de l'eau lourde constitue un des problemes les plus complexes de la chimie des reacteurs. La corrosion des materiaux constituant le coeur et le circuit d'eau lourde varie dans de larges limites avec l'etat de purete de l'eau lourde, les performances des circuits d'epuration et des mesures directes permettent d'en apprecier l'importance. Les connaissances acquises permettent de degager des normes de purete dont l'observation est susceptible de garantir un fonctionnement satisfaisant du reacteur. 4) Decomposition radiolytique de l'eau lourde: Une meilleure connaissance de son allure quantitative dans les reacteurs est necessaire pour prevoir les degagements de gaz tonnant dans les reacteurs de puissance. Le taux de radiolyse evolue avec la purete chimique de l'eau et la puissance instantanee du reacteur. L'experience des reacteurs a eau lourde du CE.A. et l'etude systematique de la decomposition radiolytique de l'eau dans le coeur des piles piscines sont exposees Mise en oeuvre du controle de la reactivite par voie physico-chimique. Controle de la reactivite par empoisonnement homogene du moderateur: Une comparaison de l'evolution de l'empoisonnement Xenon avec l'antireactivite residuelle du poison en solution pendant sa consommation

  19. Effects of a fire on runoff and erosion on mediterranean forest soils in SE Spain

    Directory of Open Access Journals (Sweden)

    Mangas, V. J.

    1992-12-01

    el suelo un incremento estadísticamente significativo del contenido en materia orgánica, nitrógeno total, fósforo asimilable y los cationes cambiables: K+, Mg2+ y N+. Por el contrario, hay una disminución de Ca2+ y de la C.I.C. Los valores modificados tras el incendio tienden a recuperar su nivel Inicial en el caso de materia orgánica, fósforo. Na+, Ca2+ y C.I.C. La escorrentía anual tras el incendio es significativamente menor que la del año anterior al incendio, mientras que la escorrentía media es significativamente menor sólo en el caso de no considerar el año más erosivo (Octubre 1987-Septiembre 1988, lo que estaría asociado con una disminución de la precipitación media tras el incendio. Por su parte, la producción de sedimentos del año posterior al incendio no presenta diferencias significativas respecto al año anterior. La disminución en la salida de nutrientes y en el volumen de escorrentía es más acentuada que la disminución en la entrada de nutrientes y en el volumen de la precipitación después del incendio. La salida de nutrientes por escorrentía tras el incendio presenta un rango entre 8 y 35% del año anterior, cuando el volumen sólo representa el 3 %, lo que Implica un aumento en su concentración.
    [fr] On a étudié les flux de ruissellement et de transport du sol, ainsi que sa composition chimique, pendant cinq ans (1985-1990, dans des parcelles d'érosion dans une localité de la Province d'Alicante (SE-Espagne. En septembre 1989, on a brûle la végétation des parcelles, en enregistrant des températures modérées. On a réalisé un suivi de la chimie du sol par trois échantillonnages: avant le feu, le jour suivant et 180 jours plus tard. Le jour après l'incendie, il s'est produit dans le sol une augmentation statistiquement significative de la teneur en matière organique, azote total, phosphore assimilable, et des cations changeables: K

  20. Foreword

    Science.gov (United States)

    Boutron, Claude; Ferrari, Christophe

    2003-05-01

    thank the members of the organising committee and Jerome Nriagu (chairman of the 11th Conference) for helping us to put together the program of this conference. Also, very special thanks are due to Christine Echevet for her continuous and expert efforts to make the Grenoble Conference a success, and to various members of the Laboratoire de Glaciologie et Géophysique de l'Environnement, especially Jocelyne Roquemora. Special thanks are also due to the President of Grenoble Alpes Métropole and the Mayor of the City of Grenoble. Finally, we are very grateful to the various co-sponsors of the conference, especially the Centre National de la Recherche Scientifique (CNRS), the University Joseph Fourier of Grenoble, the Ministère des Affaires Étrangères, the Ministère de l'Écologie et du Développement Durable, the Agence de l'Environnement et de la Maîtrise de l'Énergie (ADEME), Grenoble Alpes Métropole (La Métro), the City of Grenoble, the Region Rhône-Alpes, the Conseil Général de l'Isère, the Association Minéraux, Métaux non ferreux, Santé, Environnement (AMSE), the University of Michigan and the Société Hydrotechnique de France (SHF). Claude BOUTRON and Christophe FERRARI - Conference Co-Chairmen 12th International Conference on Heavy Metals in the Environment, Grenoble, France, 26-30 May 2003 Préface C'est un grand plaisir pour nous d'accueillir la “12e Conférence Internationale sur les Métaux Lourds dans l'Environnement en France Grenoble, au coeur des Alpes. Cette conférence est la 12e du nom, après celles qui ont eu lieu avec beaucoup de succès à Toronto (1975), Londres (1979), Amsterdam (1981), Heidelberg (1983), Athènes (1985), La Nouvelle Orléans (1987), Genève (1989), Edimbourg (1991), Hambourg (1995) et Ann Arbor (2000). Grenoble est l'une des principales ville d'Europe pour la recherche scientifique avec un très grand nombre de chercheurs dans des domaines trés variés, notamment en Physique et Chimie, Mathématiques et

  1. Recoil Processes of Cr{sup 51} in Mixed Inorganic Systems; Processus de Recul de {sup 51}Cr dans des Melanges Inorganique; 041f 0420 041e 0426 0415 0421 0421 042b 0421 042f 0414 0420 0410 041c 0418 041e 0422 0414 0410 0427 0418 0425 0420 041e 041c 0410 -51 0412 0421 041c 0415 III 0410 041d 041d 042b 0425 041d 0415 041e 0420 0413 0410 041d 0418 0427 0415 0421 041a 0418 0425 0421 0418 0421 0422 0415 041c 0410 0425 ; Procesos de Retroceso del {sup 51}Cr en Sistemas Inorganicos Mixtos

    Energy Technology Data Exchange (ETDEWEB)

    Veljkovic, S. R.; Milenkovic, S. M.; Ratkovic, M. R. [Boris Kidric Institute of Nuclear Sciences, Vinca, Yugoslavia (Serbia); Faculty Of Natural Sciences, Belgrade University, Belgrade, Yugoslavia (Serbia)

    1965-04-15

    thermiques dans le reacteur ainsi que ceux du chauffage interne qui peut se produire dans les cibles. Dans le systeme oh des chromates etaient deposes sur MgO, ils ont constate une reduction importante en ions chromiques. Les effets neutroniques depassent ceux des processus thermiques a la temperature d'irradiation, et seul un chauffage a plus de 600 Degree-Sign C a eu tendance a donner les memes resultats. Les ions chromiques n'ont pas subi de modifications au cours de l'irradiation. Un accroissement de la concentration en chromates a produit la retention bien connue de {sup 51}CrO{sub 4}{sup =}. Les chromates adsorbes sur l'alumine ont conserve leur forme d'oxyde, comme dans le systeme comportant SiO{sub 2}. La direction des effets thermiques etait la meme. Les ions chromiques adsorbes sur ces oxydes se sont comportes de facon differente. Dans le systeme comportant de l'alumine, les auteurs ont constate une importante oxydation, beaucoup plus considerable que dans les processus thermiques. En comparant l'irradiation et le chauffage, ils ont trouve une petite difference dans le systeme comportant SiO{sub 2}, mais ils ont observe un appauvrissement important en ions chromiques par diffusion sur la surface. Une tres petite concentration en composes de chrome est la particularite commune a tous les systemes. Il semble que, dans la plupart des cas, aussi bien dans les processus thermiques que dans les processus de recul, la chimie des couches minces differe du comportement normal des chromates. Cela, peut signifier qu'aux points chauds, les processus dependant de tous les composants donneraient des produits sensibles a la nature de la cible. Pour elaborer une theorie generale des processus de recul, il faudrait, semble-t-il, etudier aussi la matiere constituant la matrice. (author) [Spanish] Los autores estudiaron los efectos de la irradiacion neutronica en mezclas de cromatos o sales de cromo y oxidos inorganicos. Utilizaren Al{sub 2}O{sub 3}, SiO{sub 2} y MgO. Controlaron

  2. Industrial Sterilization st the Electron Linear-Accelerator Facility at Risoe; Sterilisation industrielle a l'aide de l'accelerateur lineaire d'electrons de Riso; Promyshlennaya sterilizatsiya oblucheniem na linejnom uskoritele ehlektronov v Rizo; Esterilizacion industrial con ayuda del acelerador lineal de electrones de Riso

    Energy Technology Data Exchange (ETDEWEB)

    Brynjolfsson, A.; Holm, N. W.; Tharup, G.; Sehested, K. [Accelerator Section, Danish Atomic Energy Commission, Research Establishment Risoe (Denmark)

    1963-11-15

    The high dose rates obtainable from high power accelerators are valuable for fundamental chemical and physical research work, and offer besides the possibility of performing pilot-plant operation prior to industrial application. The linear accelerator at Riso has been used for such purposes, including irradiation of disposable medical supplies for industrial firms on a contract base. This linear accelerator yields a stable 10 MeV electron beam with an average power of five kilowatts. The beam can be directed through a straight ahead window or through a beam bending and scanning device. The bent and scanned beam is employed for process irradiation. The packages to be irradiated are moved through the irradiation field by means of a conveyor system, which has available a full range of velocities from 0.2-600 mm/s, thus giving a wide dose range for a fixed accelerator adjustment. The facility has been in operation since the autumn of 1960 for Danish research institutions and from 1961 also for industrial radiation sterilization of disposable medical supplies, e.g. syringes, catheters, transfusion and infusion sets, and lung-heart machines. The processing rate has increased steadily, the number of packages treated during the first 3 months of 1963 being about 3000. Each package may contain, say, 900 off, 2-ml syringes. A large amount of work has gone into the refinement of the irradiation techniques, including application of reflector systems, automatic dose regulation, routine dosimetry and visual colour indicators. A short survey of these technically important details is given, and the actual sterilization processing, including handling, control and dosimetry, is described. Finally some information about the operating cost is given. (author) [French] Les forts debits de dose produits par les accelerateurs a grande puissance, en plus de leur utilisation pour les travaux de recherche fondamentale en physique et en chimie, permettent de proceder a des operations semi

  3. Fixation of Radionuclides in Titanium Dioxide and Titanates via co-Precipitation; Fixation de Radioelements dans le Bioxyde de Titane et dans les Titanates par Coprecipitation; 0424 0418 041a 0421 0410 0426 0418 042f 0420 0410 0414 0418 041e 0418 0417 041e 0422 041e 041f 041e 0412 0412 0414 0412 0423 041e 041a 0418 0421 0418 0422 0418 0422 0410 041d 0410 0418 1 0418 0422 0410 041d 0410 0422 0410 0425 041c 0415 0422 041e 0414 041e 041c 0421 041e 041e 0421 0410 0416 0414 0415 041d 0418 042f ; Fijacion de Radionuclidos en Dioxido de Titanio y Titanatos por Coprecipitacion

    Energy Technology Data Exchange (ETDEWEB)

    Levi, H. W. [Hahn-Meitner Institut fuer Kernforschung, Berlin-Wannsee, Federal Republic of Germany (Germany)

    1963-02-15

    radioactives, mais elles different quant au mode de fixation dans le produit final. La coprecipitation presente deux inconvenients: il est difficile de separer les boues de haute activite de la solution; elle se prete mal a la separation du cesium. Ses avantages sont les suivants: elle permet un traitement sans phase intermediaire; elle permet de traiter des quantites plus considerables que la methode d'adsorption par les mineraux argileux; elle permet d'eviter les operations d'evaporation. Aussi a-t-il paru interessant d'etudier de maniere plus approfondie la chimie de systemes de coprecipitation appropries. Le premier systeme choisi etait constitue par du bioxyde de titane en solution aqueuse, a cause des excellentes proprietes de fixation de TiO{sub 2} et des titanates. On a etudie, dans differentes conditions experimentales, comment cette solution se pretait a la coprecipitation. Pour certains radioelements, le coefficient de distribution etait aussi bon ou meme meilleur qu'avec les autres oxydes en solution aqueuse. Une forte concentration d'ions de radioelement ou d'ions similaires entraine une diminution du coefficient de distribution. On peut y remedier en precipitant simultanement des carbonates ou des oxalates qui absorbent la plus grande partie des ions. L'influence d'une forte teneur en aluminium a egalement ete etudiee. On a entrepris une nouvelle serie d'experiences sur la formation, au cours du traitement a haute temperature, d'anatase et de rutile a partir de precipites de solutions aqueuses de TiO{sub 2} pur et de titanates a partir de precipites de solutions aqueuses de TiO{sub 2} et d'un carbonate ou d*un oxalate. (author) [Spanish] Los metodos de fijacion de radionuclidos mas frecuentemente estudiados son la calcinacion y la adsorcion en minerales arcillosos. Un tercer procedimiento (la fijacion por coprecipitacion) no ha despertado mucho interes hasta el presente. Los tres metodos se caracterizan por el tratamiento a temperatura elevada de un producto

  4. 2002年召开的部分国际地学会议

    Institute of Scientific and Technical Information of China (English)

    黎明

    2002-01-01

    @@时 间 会  议  名  称 地 点 网址(http://)或E-mail 3月4~7日 人为影响渗漏和地下水中的地球化学过程与长期 作用国际会议 不莱梅 (德国) www:geochemie.uni-bremen.del 3月4~8日 第33届月球与行星科学会议 休斯顿 (美国) perry@lpi.usra.edu 3月10~13日 4月7~10日 美国石油地质学家协会年会 休斯顿 (美国) www.aapg.org 3月11~13日 第4届中东地球科学展览会议 伦敦 (英国) pmckean@ montnet.com 3月19~22日 第19届非洲地质学讨论会 杰迪代 (摩洛哥) www.ucd.ac.ma/geologie/cag 19.html 3月20~23日 第6届石油与天然气勘探、生产与加工技术展览会 Pattaya (泰国) pmckean@ montnet.com 3月20~27日 国家地球科学教师协会年会与展览会 圣迭戈 (美国) fireton@kesmos.agu.org 3月23~27日 干旱区水资源管理国际会议 科威特 mrashed@kisr.ed.kw 3月24~27日 古代与现代海岸平原资源环境会议--含水层非均质性与环境含义 查尔斯顿 (美国) mary.harris@srs.gov 3月25~29日 国际地下水讨论会--非均质-介质中的测量与模拟 旧金山 (美国) anfindk@bechtel.com 4月14~16日 经济地质学家学会全球研究2000年会 --发现的综合方法会议 丹佛 (美国) www.seg2002.org 4月14~26日 第15届层理岩地质会议 圣克鲁斯 (阿根廷) www.Cenpat.edu.ary xvcga 4月24~26日 第3届管理信息系统、GIS 和遥感国际会议 南安普敦 www.wessex.ac.uk/conferences/2002/mis02 5月 培雷火山喷发100周年研讨会   www.iavcei.org/ 5月6~8日 第9届计算机技术在环境研究中的发展与应用 皋尔根 (挪威) www.wessex.ac.uu/conferency 2002/env02 5月5~10日 沉积与水文之间相互作用国际研讨会 班夫 (加拿大) iasws@unbc.ca 5月12~17日 平衡地下水预算国际研讨会 达尔文 (澳大利亚) www.1octa4.net.au/iahnt/conference.htm 5月12~17日 短期野外会议:德国中部的第四纪 魏 玛 (德国) www

  5. Present Status of Nitrogen Fixation by Reactor Radiation; Etat Actuel des Recherches sur l'oxydation directe de l'azote sous irradiation dans des reacteurs; Sovremennoe sostoyani opytov po okisleniyu azota izlucheniem iz reaktorov; Estado actual de las investigaciones sobre fijacion del nitrogeno por irradiacion en reactores

    Energy Technology Data Exchange (ETDEWEB)

    Harteck, P; Dondes, S [Rensselaer Polytechnic Institute, Troy, NY (United States)

    1960-07-15

    'oxydation directe de l'azote sous irradiation, entreprises depuis plusieurs annees par le Rensselaer Polytechnic Institute et le Brookhaven National Laboratory, utilisent directement les particules de recul de fission comme rayonnements ionisants, au moyen de la dispersion d'uranium-235 dans des fibres de verre de cinq microns de diametre environ. Les auteurs ont determine les effets de la temperature, de la pression et du rapport azote/oxygene sur la valeur de G pour l'oxydation de l'azote et ont publie le compte rendu de leurs travaux. Ils en donnent un bref apercu. Les recherches en question ont ete effectuees avec des systemes statiques; plus recemment des systemes statiques et des systemes a circulation ont ete utilises a la fois. Avec les systemes statiques, les auteurs se sont surtout attaches a etudier l'effet de l'intensite des rayonnements, notamment sur la cinetique d'equilibre sous irradiation. Ils ont constate que dans des melanges ou le rapport azote/oxygene est de 4 a 1 et de 2 a 1 N0{sub 2} et N{sub 2}0 se forment jusqu'a epuisement de tout l'oxygene present. Un systeme a circulation continue (cycling) fonctionne maintenant dans une boucle a l'interieur du reacteur de Brookhaven. Les auteurs fournissent sur les effets de la temperature, de la pression, du rapport azote/oxygene et de l'intensite des rayonnements des donnees que l'on pourra utiliser pour etablir un projet de reacteur de chimie nucleaire. Le systeme actuel fonctionne sous 10 atmospheres et a 150{sup o}C. La temperature est fonction de l'energie de fission liberee dans les fibres de verre et de la resistance thermique du circuit. Une autre boucle, qui doit fonctionner sous 50 - 75 atmospheres et a 600{sup o} C, est en construction. Il est possible, grace a ces boucles, d'etudier les caracteristiques d'un systeme continu, y compris le comportement des produits de fission liberes dans le courant, gazeux. Les auteurs distinguent trois stades dans la cinetique complexe de l'oxydation de l'azote: reactions

  6. Contribuição para o conhecimento da intoxicação pelo veneno dos "escorpiões"

    Directory of Open Access Journals (Sweden)

    Octavio de Magalhães

    1928-01-01

    Full Text Available Nous avons travaillé à Bello Horizonte, Etat de Minas, avec le venin de 4 espèces de Scorpions: Tityus bahiensis (C. L. KOCK, 1836. Tityus serrulatus (LUTZ-MELLO, 1922. Tityus dorsomaculatus (LUTZ – MELLO, 1922. Bothriurus (espèce em étude, sur un total de 13.640 individus. Nous avons essayé et observe l’action du venin sur 97 espèces differentes d’êtres vivants – depuis les chlamydozoaires jusqu’à l’«Homo sapiens». Nous avons cherché à déterminer une unité toxique «plus précise, plus régulierè». Les étalons dits «unité vésicule», «unité morsure» sont inconstants et sans rigueur. Tout au plus, peuvent ils server à l’étude de l’action générale du venin, et cela meme, dans certains cas seulement. Nous avons employé la pesée pour determiner l’unité toxique. Ce qui est important pour qui étudie ces sujets ce n’est pás lê nombre de vésicules, mais bien la quantité de venin humide ou desséché qu’elles contiennent. La balance, pour notre travail, est um moyen indicateur de bien plus grande précision que la «vésicule» ou la «morsure». Nous sommes parvenus à prouver qu’il existe une relation constante entre le poid brut des vésicules et la quantité de venin humide ou desséché qu’elles contiennent dans leur intérieur. Donc em pesant les vésicules, nous pesons indirectement le venin. Peu nous importe qu’il y ait 10 ou 100 vésicules. Il nous importe seulement de savoir combien elles pèsent, et de déterminer par ce fait, la quantité proportionnelle de vain pur. La technique générale est la suivante: Nous pesons um certain nombre de vésicules. Nous triturons ensuite, dans um mortier stérilisé et nous emulsionnons, par l’addition consécutive d’eau distillée, stérilisée. Nous filtrons l’émulsion sur le papier filtre employé em chimie, préalablement taré et desséché dans une atmosphere de chlorure de calcium. Après le filtrage on sèche à nouveau les

  7. Radiation Polymerization of Acetylene Hydrocarbons. Special Features; Particularites de la polymerisation radiochimique des hydrocarbures acetyleniques; Radiatsionnaya polimerizatsiya atsetilenovykh proizvodnykh; Particularidades de la radiopolimerizacion de los hidrocarburos acetilenicos

    Energy Technology Data Exchange (ETDEWEB)

    Barkalov, I. M.; Gol' danskij, V. I.; Go, Min' -Gao

    1963-11-15

    benzene radical. The pronounced deviations from the additivity rule in the case of radiation polymerization in different solvents indicate a large energy transfer to acetylene hydrocarbons and their polymers. (author) [French] La synthese des polymeres a systeme reticule et l'etude de leurs proprietes constituent une branche nouvelle et tres riche en promesses de la chimie des composes a poids moleculaire eleve. Les polymeres de ce type sont caracterises par un haut degre de deplacement des electrons p dans la macromolecule. La reduction de l'energie d'excitation jusqu'a formation de la triple liaison et la diminution du potentiel d'ionisation en presence de longues chafhes de reticulation sont a l'origine des proprietes semi-conductrices et des particularites magnetiques specifiques de ces composes. En outre, ces systemes reticules se sont reveles tres efficaces comme stabilisateurs contre la destruction des polymeres par thermo-oxydation et photo-oxydation. Une methode pratique pour obtenir des polymeres de ce genre est fournie par la polymerisation radiochimique des derives de l'acetylene. Elle seule permet d'obtenir, a basse temperature, des polymeres libres de toute impurete due aux initiateurs. La cinetique de la polymerisation radiochimique du phenylacetylene et d'autres derives de l'acetylene presente une serie de traits qui sont caracteristiques de la polymerisation ionique mais tout a fait inhabituels pour la polymerisation par radicaux (vitesse de polymerisation preportionnelle a la vitesse d'amorcage; energie d'activation tres faible; absence d'inhibition par l'oxygene). Neanmoins, cette polymerisation semble etre due a l'action des radicaux. Les auteurs sont parvenus a cene conclusion, en etudiant l'amorcage de la polymerisation des hydrocarbures acetyleniques par des initiateurs ayant le caractere typique d'un radical, tel que le peroxyde de benzoide et le dinitryle de l'acide azo-i-butyrique. A ce propos, ils ont examine les particularites de la cinetique

  8. Application of radioisotopes to the investigation of the kinetics and mechanism of reactions of some inorganic complex compounds; Application des radioisotopes a l'etude de la cinetique et du mecanisme des reactions de certains complexes inorganiques; Primenenie radioizotopov k issledovaniyam kinetiki i mekhanizma reaktsij nekotorykh neorganicheskikh slozhnykh soedinenij; Aplicacion de los radioisotopos al estudio de la cinetica y del mecanismo de las reacciones de algunos complejos inorganicos

    Energy Technology Data Exchange (ETDEWEB)

    Harris, Gordon M [Department of Chemistry, University of Buffalo, Buffalo 14, NY (United States)

    1962-03-15

    cyanide is an important end-product. (author) [French] Les radioisotopes sont particulierement precieux dans l'etude de nombreux types de reactions de chimie minerale, notamment de reactions ou interviennent des ions complexes en solution aqueuse. Les recherches sur la vitesse et le mecanisme des echanges isotopiques constituent un aspect important de ces applications. C'est ainsi qu'on a fait une serie d'etudes sur l'echange entre du carbonate ''libre'' marque au carbone-14 et le carbonate qui joue le role de coordinafc dans les ions complexes octaedriques du type CoA{sub 2}CO{sub 3}{sup +}, ou A represente le 2NH{sub 3}, ou l'ethylene-diamine (en), ou la propylene-diamine (pn) ou la trimethylene-diamine (tn). Grace aux etudes ainsi effectuees, on connait assez exactement la nature de ces reactions par substitution de coordinate, ainsi que le role joue par les coordinais amines qui ne participent pas a l'echange. Des etudes analogues sur l'echange entre oxalates dans les complexes tri-oxaliques de forme M (C{sub 2}O{sub 4}){sub 3}{sup 3-}, ou M=Co (III), Cr (III), ou Rh (III), n'ont pas ete moins fecondes en resultats. Une autre technique, applicable seulement lorsqu'on utilise des radioisotopes de faible poids atomique comme le carbone-14, consiste a observer les effets d'equilibre ou les effets cinetiques que les isotopes exercent sur la reaction etudiee. C'est ainsi qu'il a ete possible d'interpreter des differences dans le mecanisme d'echange du coordinat carbonate dans le Coen{sub 2}CO{sub 3}{sup +} et le Cotn{sub 2}CO{sub 3}{sup +}, par mesure de l'effet isotopique a l'etat d'equilibre dans la reaction d'echange des carbonates. De meme, des donnees sur l'effet isotopique cinetique dans l'hydratation avec catalyseur acide de l'ion Co(NH{sub 3}){sub 4}CO{sub 3}{sup +} ont confirme les deductions faites en ce qui concerne l'etape a laquelle se rompt la liaison, etape qui determine la vitesse de ces reactions. Enfin, la determination des positions successives de

  9. Plant Measurement, Sampling and Analysis for Accountancy Purposes with Particular Reference to Separation Plants at Windscale; Mesures, Echantillonnages et Analyses en Usine a des Fins Comptables, Notamment dans les Installations de Separation de Windscale; Izmereniya, vzyatie obraztsov i analizy v tselyakh ucheta na opyte ustanovki razdeleniya radioizotopov v uindskejle; Medicion, Muestreo y Analisis para Fines Contables, Especialmente en las Plantas de Separacion de Windscale

    Energy Technology Data Exchange (ETDEWEB)

    Davidson, A. S.; Elliott, F.; Powell, R.; Swinburn, K. A. [United Kingdom Atomic Energy Authority, Windscale and Calder Works, Cumberland (United Kingdom)

    1966-02-15

    requires to be corrected for. Precisions of all the methods are given and the methods actually used for the New Separation Plant are indicated. (author) [French] Tous les chiffres interessant la comptabiUte des matieres speciales comportent un ou plusieurs des parametres suivants: mesures, echantillonnages et analyses. Pour ce qui est de la mesure en usine, il est preferable de proceder a des pesages toutes les fois que cela est possible; ainsi, le calcul du plutonium entrant dans la nouvelle usine de separation est fonde sur le poids des barres d'uranium entrantes. Les auteurs examinent les diverses methodes de mesure des volumes, a savoir: a) 'pneumercator', et b) methode des radioindicateurs utilisant le radiocesium. Le memoire indique l'exactitude et la precision reconnues a chaque methode. On procede a l'echantillonnage des solutions par lots, en utilisant des pipettes a vide, apres complete homogeneisation. Pour les operations en continu, qui exigent une grande exactitude, on a concu une echantillonneuse a fonctionnement continu qui est utilisee sur le circuit d'entree de la nouvelle usine de separation. La methode habituelle d'echantillonnage pratiquee a Windscale consiste a forer des lingots metalliques; pour d'autres solides, on homogeneise dans toute la mesure du possible (pour l'oxyde de plutonium, par exemple, on utilise un melangeur conique en Y), apres quoi on procede a l'echantillonnage. Quant a l'analyse chimique, la precision requise pour une methode donnee depend du nombre de dosages effectues au cours de chaque periode comptable. Ainsi, une methode exacte mais peu precise exige un grand nombre d'analyses. Il peut etre plus economique de reduire le nombre de dosages et d'augmenter leur precision. Les auteurs examinent en detail les methodes de dosage du plutonium, notamment les suivantes: a) chimie des corps radioactifs, b) colorimetrie utilisant du thoronol, c) separation du plutonium complexe avec EDTA et retitrage de l'EeDTA excedentaire, d

  10. Quantitative Evaluation of Dose-Response Relationships in Human Beings with Skeletal Burdens of Radium-226 and Radium-228; Evaluation Quantitative de la Relation entre Dose et Reponse chez des Sujets Ayant une Charge Squelettique de Radium 226 et Radium 228; 041a 041e 041b 0414 ; Evaluacion Cuantitativa de las Relaciones Dosis-Respuesta en Seres Humanos con Cargas de Radio-226 y Radio-228 en el Esqueleto

    Energy Technology Data Exchange (ETDEWEB)

    Maletskos, C. J.; Braun, A. G.; Shanahan, M. M.; Evans, R. D. [Radioactivity Center, Department of Physics. Massachusetts Institute of Technology, Cambridge, MA (United States)

    1964-11-15

    Utah. Further analysis is indicated. No clinically significant signs or symptoms are observed at MPRE < 0.5 {mu}c. In the region 10{sup -3} to 10{sup -1} {mu}c MPRE the clinical data are in the normal range. (author) [French] Les 361 sujets ayant une charge squelettique de radium 226 et radium 228, qui ont ete examines au laboratoire oue travaillent les auteurs, constituent actuellement un echantillon assez important pour permettre l'evaluation quantitative de la relation entre la reponse biologique et la dose due a la contamination interne. Les auteurs decrivent les methodes utilisees pour une telle analyse et les resultats obtenus. Les reponses biologiques consistent en une variete de resultats cliniques tels que les radiogrammes obtenus, les tumeurs, les fractures, les analyses d'urine, l'hematologie, la chimie du sang et l'electrophorese des proteines. La dose due a la contamination interne est calculee et exprimee par la charge corporelle retenue, en microcuries d'equivalent minimum de radium 226 pur, en rads cumulatifs et en rad-annees cumulatifs. Dans la premiere phase de l'analyse, on determine s'il existe une relation entre un parametre clinique et la dose. On fait cette determination en recourant a un test de-contingence, permettant de comparer les donnees reelles et un modele d'independance entre les deux variables que l'on considere comme possible. Si l'on trouve qu'il n'y a pas d'independance, on fait une hypothese relative a,la relation qui existe et on obtient une description quantitative de la dependance. On fait un ajustement par la methode des moindres carres pour calculer les coefficients et les ecarts types des coefficients d'un developpement en serie. Une telle expression fournit une description quantitative empirique des resultats en meme temps qu'une mesure de leur variabilite, elle est utile pour une comparaison impartiale avec les resultats des autres laboratoires, mais n'implique aucun mecanisme biophysique. Les auteurs ont compare les

  11. Préface

    Science.gov (United States)

    Ouerdane, Youcef; Laporte, Pierre

    2005-06-01

    L'objectif de la série de colloques UVX est de réunir, au rythme d'une fois tous les deux ans, les scientifiques et industriels travaillant dans le domaine du développement des sources de photon de grande énergie (UV, VUV, et X) et de leurs applications. En particulier cette manifestation est l'occasion de faire se rencontrer une communauté très pluridisciplinaire (physique, chimie, biologie, sciences de l'univers) liée à des domaines en forte évolution technologique (lasers et rayonnement synchrotron notamment). Le colloque UVX 2004 s'est tenu au Palais des Congrès de Saint-Étienne (42000) du 7 au 11 juin 2004. La période écoulée depuis l'édition précédente (Oléron 2002) a été particulièrement active dans tous les domaines concernés : grands projets de sources, méthodes de diagnostic au sens large. Une nouvelle fois on constate que le bref et l'ultra-bref ont une place privilégiée, qu'il s'agisse du travail sur les accélérateurs ou sur les lasers qui, bien sûr, dans la course aux temps courts remportent la palme avec la présence de spécialistes du domaine attoseconde. La communauté représentée a la chance d'être en prise directe avec de très grands projets en phase active de réalisation comme le Laser Megajoule (LMJ), la source SOLEIL, et un projet d'ampleur plus modeste mais remarquable dans son domaine : la source LASERIX d'Orsay/Palaiseau. On pourra citer aussi le projet Arc en Ciel qui, lui, est encore au stade de sa définition. - SOLEIL, source de nouvelle génération de rayonnement synchrotron (plateau de Saclay) est dans une phase active de réalisation : achèvement de l'infrastructure en 2005 et injection du 1o faisceau dans l'anneau de stockage prévu également en 2005. Cette source devrait être la meilleure au monde dans le domaine VUV/X mous, tout en restant très polyvalente (brillance, accordabilité, structure temporelle, polarisation) et complémentaire de l'ESRF. Au final on disposera de 21 lignes de lumi

  12. Modélisation thermodynamique et cinétique des réactions diagénétiques dans les bassins sédimentaires. Présentation du modèle géochimique KINDISP Thermodynamic and Kinetic Modelling of Diagenetic Reactions in Sedimentary Basins. Description of the Geochemical Code Kindisp

    Directory of Open Access Journals (Sweden)

    Clement A.

    2006-11-01

    Full Text Available Le programme thermodynamique et cinétique KINDISP (KINetic of DISsolution and Precipitation simule les interactions minéraux/solutions aqueuses en considérant la dissolution irréversible des réactants et la précipitation réversible ou irréversible des phases secondaires. Les lois générales introduites dans le modèle ont pour base théorique la Thermodynamique des Processus Irréversibles. Les interactions eaux/roches à basse température (25-30 °C sont interprétées théoriquement à l'aide de la Théorie de l'Etat de Transition et de la Chimie de Coordination de Surface. Le mécanisme qui limite la vitesse de dissolution ou de précipitation d'un minéral, c'est-à-dire le mécanisme le plus lent pour les réactions irréversibles successives, est soit la diffusion moléculaire aqueuse d'une entité élémentaire (atome, molécule . . . ou bien la réaction de surface (adsorption-désorption d'une entité élémentaire. A chaque étape du calcul, caractérisé par un incrément de temps (dt, le modèle informatique KINDISP calcule les vitesses de réaction pour chaque minéral réactif dans le système eau-roche. A partir de ce calcul, le modèle compare les vitesses contrôlées par la diffusion moléculaire et par la réaction de surface. Ensuite, KINDISP retient la vitesse la plus lente pour représenter la loi de dissolution d'un minéral réactif primaire ou la loi de précipitation d'une phase néoformée secondaire. La croissance des minéraux secondaires est simulée, soit à l'équilibre thermodynamique, soit en domaine de sursaturation (en nonéquilibre, après une étape de nucléation, lorsque le point de sursaturation critique S* est atteint. Le programme géochimique KINDISP est divisé en deux ensembles : un module de calcul d'équilibre initial de la solution aqueuse appelé EQUILT et un module constitué de la procédure de perturbation par incréments de temps rendant compte de l'évolution géochimique du syst

  13. Aspects chimiques de la combustion du charbon pulvérisé. Première partie Chemical Aspects of the Combustion of Pulverized Coal. Part One

    Directory of Open Access Journals (Sweden)

    De Soete G. G.

    2006-11-01

    deux mécanismes totalement différents, par exemple entre le mécanisme d'ignition homogène et le mécanisme d'ignition hétérogène du charbon, avec des conséquences pratiques pour la stabilisation de la flamme industrielle ; autre exemple : la compétition entre les divers mécanismes homogènes de formation d'oxydes d'azote et les mécanismes hétérogènes de leur réduction sur des particules solides de coke, de suie et de cendre. Avec ces idées présentes comme un leitmotiv implicite, on passe en revue les grandes étapes de la flamme industrielle de charbon pulvérisé : la dévolatilisation rapide avec la formation progressive de volatils gazeux, de goudrons et de coke ; la transformation partielle des produits gazeux et liquides de pyrolyse en suies ainsi que leur oxydation en phase gazeuse ; la combustion hétérogène du coke ; l'ignition du charbon et sa dépendance par rapport à des processus critiques homogènes et (ou hétérogènes. Comme exemple typique d'un épiphénomènechimique, on suit la transformation des espèces azotées en NO et en N2, qui se greffe en contrepoint et à chaque pas sur tes différents thèmes successifs de cette symphonie de l'oxydation du charbon. En de nombreux points de cette évolution du charbon à travers la flamme, les connaissances de la chimie de com-bustion en phase gazeuse constituent un instrument utile d'interprétation (par exemple : pour l'oxydation des volatils, pour la discussion des modalités d'ignition. II n'en reste pas moins vrai que la plupart des problèmes chimiques hétérogènes sont bien spécifiques de la flamme de charbon ; leur traitement est rendu ardu à cause de la complexité, évolutive au cours de la combustion, du combustible solide lui-même. It is not easy to obtain a full picture of the multiple chemical phenomena which occur inside a pulverized coal flame. This bibliographie review attempts to give more than just a juxtaposition of data from the recent literature and risks making

  14. The use and evolution of the CEA research reactors; Utilisation et evolution des reacteurs de recherche du C.E.A

    Energy Technology Data Exchange (ETDEWEB)

    Rossillon, F; Chauvez, C [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    reacteurs en montrant ce qu'a ete jusqu'a present leur utilisation, et comment certaines modifications ont permis de les adapter a l'evolution des programmes. Ils precisent egalement les raisons qui ont conduit a l'elaboration du projet de la nouvelle pile OSIRIS, La pile ZOE, la plus ancienne du CEA, est en service au Centre de Fontenay-aux-Roses depuis 1948. Elle est principalement utilisee pour les mesures de section efficace d'absorption du graphite, et pour diverses irradiations de courte duree ne necessitant que des flux peu eleves. La Pile EL2, en service depuis 1952, a permis les premieres etudes liees au refroidissement par gaz. Elle a ete tres utilisee pour la production des radioisotopes et pour de nombreuses experiences de physique, de metallurgie et de physico-chimie - le vieillissement de certaines parties du reacteur a conduit a decider l'arret prochain de cette installation. La Pile EL. 3 a ete tres utilisee pour les experiences de physique et pour l'etude des combustibles. L'adoption d'une nouvelle structure pour le coeur (solution 'Cristal de neige') va permettre d'accroitre considerablement les possibilites de la pile pour les irradiations en neutrons rapides. La pile TRITON-I, piscine de 2 MW, est surtout utilisee pour les irradiations en neutrons rapides et en gamma. Certaines modifications, actuellement en cours, permettront d'accroitre la puissance du reacteur jusqu'a 4 ou 5 MW. Dans un compartiment voisin de TRITON-I est implantee la Pile TRITON-II, de meme structure generale, mais dont la puissance maximum est de 100 kW. TRITON-II est utilisee exclusivement pour les etudes de protections. MELUSINE, pile piscine de 2 MW est en fonctionnement au Centre d'Etudes Nucleaires de Grenoble depuis 1959. Elle a permis l'execution d'un programme important concernant surtout la physique du solide, l'etude fondamentale de combustibles refractaires et de graphites speciaux, et l'etude du comportement des liquides organiques sous radiations. Les installations de

  15. Reactions of Hot Hydrogen Atoms with Ethylene. The Role of Excited Ethyl Radicals as Intermediate Products; Reactions des Atomes Chauds d'Hydrogene avec l'Ethylene. Le Role des Radicaux Ethyle Excites Comme Produits Intermediaires; Reaktsiya goryachikh atomov vodoroda s ehtilenom. Rol' vozbuzhdennykh ehtil'nykh radikalov kak promezhutochnykh produktov; Reacciones de Atomos Calientes de Hidrogeno con Etileno Papel de los Radicales Etilicos Excitados como Productos Intermedios

    Energy Technology Data Exchange (ETDEWEB)

    Dzantiev, B. G.; Shvedchikov, A. P. [Institut Himicheskoj Fiziki AN SSSR, SSSR (Russian Federation)

    1965-04-15

    the target. Lowering the temperature from 50 Degree-Sign C to -78 Degree-Sign C has little effect on the distribution of labelled products; however, in the transition to heavy ethylene (-196 Degree-Sign C) a phase effect is observed; the HT and C{sub 4}H{sub 9}T yield decreases and the activity of the parent compound C{sub 2}H{sub 3}T increases, In the radiolysis of C{sub 2}H{sub 4} and its mixtures with ammonia the ratio C{sub 2}H{sub 6}/C{sub 4}H{sub 10} is equal to 1.0 {+-} 0.3, which does not agree with the standard scheme for disproportionation and recombination reactions of thermal ethylene radicals (C{sub 2}H{sub 6}/C{sub 4}H{sub 10} = 0.2 {+-} 0.1). On the basis of data on the effect of helium addition and temperature on C{sub 2}H{sub 6} and C{sub 4}H{sub 10}, yield in the radiolysis of C{sub 2}H{sub 4}, and in the photolysis of mixtures of C{sub 2}H{sub 4} and HI, we were able to get an idea of the formation of excited ethylene radicals of C2H* These are obtained as a result of the addition of hot hydrogen atoms (generated radiolytically or photolytically) to ethylene: H* + C{sub 2}H{sub 4} = C{sub 2}H*{sub 5}. It is shown that the C{sub 2}H*{sub 5} radical easily enters into the stripping reaction C{sub 2}H*{sub 5} + RH = C{sub 2}H{sub 6} + R, which accounts for the ''excess'' quantity of ethane formed in the radiolysis of ethylene [French] On sait qu'a la suite des reactions nucleaires Li{sup 6}(n, {alpha})T et He{sup 3}(n, p) T se forment des atomes chauds de tritium. La forte reactivite chimique de ces atomes determine a maints egards les particularites chimiques des effets dus aux transformations nucleaires. Or, les atomes chauds de tritium peuvent jouer un role important, non seulement en chimie nucleaire, mais aussi dans d'autres domaines de la chimie des hautes energies, notamment dans la radiolyse, la photolyse, etc. Dans le memoire, on essaie de comparer le comportement des atomes chauds de tritium obtenus par les moyens suivants: reaction Li{sup 6

  16. Geología de la margen activa del Perú entre los 3° y 12° de latitud sur

    Directory of Open Access Journals (Sweden)

    1990-01-01

    Full Text Available GEOLOGIE DE LA MARGE ACTIVE DU PEROU ENTRE 3° ET 12° DE LATITUDE SUD. La structure de la marge de type andin du Pérou est bien connue le long de trois profils sismiques multitraces localisés entre 5° et 12º Sud, au large de Paita (Profil CDP3, de Chimbote (CDP2 et Huacho (CDP1, du Nord vers le Sud. Des données additionnelles existent le long de ces transects il s'agit des levers SeaBEAM et SeaMARC II couvrant de vastes surfaces, de dragages et de carottages. Pendant le Leg. 112 du programme ODP, le Joides Resolution a foré 10 sites essentiellement localisés le long des profils CDP1 (679, 680, 681, 682 et 683 et CDP2 (683, 684 et 685. Les résultats du 'Nazca Plate Project' (1972-1980 ont montré que les roches métamorphiques du socle sud-américain s'étendent au moins jusqu'au bord du plateau continental et que l'accrétion de sédiments existe sur le bas de la pente continentale. Le retraitement postérieur des profils sismiques CDP1, CDP2 et CDP3 et les données bathymétriques SeaBEAM ont montré que la limite entre le socle continental de la marge et le prisme d'accrétion est localisé à la limite entre la pente moyenne et la pente inférieure de la marge. Cette limite marque également un changement dans le régime tectonique de la marge qui passe de l'extension pour le haut de pente à la compression vers le bas de pente. Les profils sismiques CDP1 et CDP2 montrent une discordance majeure de l'Eocène sur le socle identique à celle forée aux puits pétroliers Delphin et Ballena. Cette discordance est attribuée à la phase Incaïque (67 Ma à 57 Ma bien connue à terre. Pendant le Leg. 112, l'Eocène a été foré sur trois sites de la pente moyenne et du bas de pente de la marge. Au site 688, l'Eocène présente des faciès marins de faible profondeur d'eau appartenant au plateau continental et à la pente supérieure comme l'indiquent les foraminifères benthiques. Cet Eocène (57 Ma à 40 Ma est recouvert en discordance

  17. Production of Olefins and Higher Hydrocarbons by Thermal Coupling of Methane Production d'oléfines et d'hydrocarbures supérieurs par couplage thermique du méthane

    Directory of Open Access Journals (Sweden)

    Weill J.

    2006-11-01

    'oxychloration d'éthylène pour un prix de pétrole brut de l'ordre de 23 à 27 $ par baril, alors que les autres procédés de production d'acétylène ne le sont jamais. Si l'hydrogène ne peut être valorisé chimiquement, le seuil de compétitivité passe à 30 $ par baril. En ce qui concerne la production d'éthylène, les figures 12a, 12b montrent que le procédé de pyrolyse du méthane devient compétitif pour un prix de pétrole brut compris entre 30 et 35 $ par baril. On remarque également qu'une unité de capacité plus faible avec une valorisation complète de l'hydrogène est plus intéressante qu'une unité de forte capacité sans utilisation chimique complète de l'hydrogène. Bien que pour un développement technologique de cet ampleur, de nombreux travaux soient encore nécessaires, les excellents résultats déjà obtenus à l'aide d'une technologie totalement innovatrice devraient permettre au couplage thermique du méthane de répondre à certains challenges futurs des pays industrialisés et de la France en particulier comme l'obtention de bases pétrochimiques non pétrolières, la réponse au besoin futur en hydrogène, le redémarrage d'une chimie fondée sur l'acétylène.

  18. EDITORIAL: Announcing the 2009 Measurement Science and Technology Outstanding Paper Awards Announcing the 2009 Measurement Science and Technology Outstanding Paper Awards

    Science.gov (United States)

    Foss, John; Dewhurst, Richard; Fujii, Kenichi; Regtien, Paul

    2010-06-01

    Bretagne, CS 83818, 29238 Brest Cédex 3, France Laboratoire de Métrologie et de Chimie Océanographique, SHOM 13 rue du Châtelier, BP 30316, 29603 Brest Cedex, France The absolute salinity of seawater is an important component in the determination of the ocean's thermodynamic properties. This paper [3] presents a measurement system for very accurate determination of the salinity. The method is based on measuring the refractive index of seawater, a parameter that is related to the salinity. Although the method is essentially simple: using a prism and a PSD for direct measurement of the angle of refraction, the refraction also depends on many more parameters (temperature, pressure, wavelength). Moreover, for obtaining accurate salinity values, a high resolution of the refractive index is required, of the order of 10-7, under all possible conditions. Starting with a list of notations and symbols, the paper follows with an overview of existing methods for salinity measurements and their performances. Next, the principle based on refractometry is introduced, and a theoretical model is presented, comprising a large number of parameters that influence the properties of the refractometer. From this analysis there follows an optimization of the geometry of the device. The sensitivity for salinity and other water parameters are estimated from theory, and verified experimentally. Salinity measurements are compared with those using standard salinometers, and show an uncertainty less than a few 10-3 psu (practical salinity units). The obtained resolution is about 4 × 10-7, which is limited by that of the readout electronics of the PSD. It is demonstrated that this can be further improved to achieve the required resolution lower than 10-7. The authors make clear that their prototype, the length of which is about 12 cm, is an important step to a fully in situ oceanographic salinometer, but further testing is required to confirm reliability. Indeed, the paper does not report on long

  19. Influence of Clays on Borehole Stability : a Literature Survey Part One: Occurence of Drilling Problems. Physico-Chemical Description of Clays and of Their Interaction with Fluids Influence des argiles sur la stabilité des parois de puits : revue bibliographique. Première partie : les problèmes rencontrés lors du forage dans les argiles. Description physico-chimique des argiles et de leur interaction avec les fluides

    Directory of Open Access Journals (Sweden)

    Forsans T.

    2006-11-01

    épandues dans le monde entier, à diverses profondeurs, donc dans des états de compaction et d'évolution diagénétique différents. Leur comportement a conduit à une classification opérationnelle. Des solutions empiriques, destinées à protéger les parois de puits, ont été mises en oeuvre. Toutefois, il apparaît évident que des solutions de caractère général ne peuvent résulter que d'un effort conjoint en mécanique des roches et en physico-chimie : tel est l'objectif du programme STAR. La seconde section est consacrée à la description des réactions physico-chimiques entre les argiles et l'eau. Après avoir décrit les argiles en tant que solides, et plus particulièrement les argiles gonflantesqui ont une charge structurale faible compensée par un cation interfoliaire échangeable, on s'attache au comportement de l'eau qui leur est associée en fonction du degré d'humidité et de la nature et de la concentration des sels dans l'eau. Le gonflement cristallin , limité à une teneur en eau de 50 % environ, et correspondant à des pressions de gonflement de milliers d'atmosphères, est distingué du gonflement osmotique , qui intervient à de plus fortes hydratations, et induit des pressions de l'ordre de la dizaine d'atmosphères au maximum. L'influence spécifique des cations comme le potassium et le calcium est décrite. Des exemples de comportement à la compaction, fonction de la nature des argiles et des cations sont décrits. Il apparaît qu'une description très précise des conditions de départ et du déroulement des phénomènes est indispensable pour l'interprétation, et qu'elle est malheureusement absente dans nombre de publications. La troisième section traite de la description mécanique du comportement des roches argileuses lors du forage. La possibilité de modéliser ce comportement dépend de l'acquisition des paramètres pertinents, et du choix du modèle : le modèle Cam Clay, qui utilise une loi élasto-plastique est donné en exemple

  20. Preface

    Science.gov (United States)

    Gorse, D.; Boutard, J.-L.

    2002-09-01

    The Symposium on “Structural materials for Hybrid systems: A challenge in metallurgy" was held during the “Journées d'Automne 2001" of the “Société Française de Métallurgie et de Matériaux", Paris from October 29 through 31, 2001. The editors of this volume, D. Gorse and J.-L. Boutard, would like to acknowledge GDR GEDEON, CEA - Direction de l'énergie Nucléaire, CNRS - Département des Sciences Chimiques, et Centre d'études de Chimie Métallurgique for sponsoring this symposium. This symposium was divided into three sessions dealing with i) thermodynamics, intergranular penetration and liquid metal embrittlement, ii) irradiation effects in structural materials and iii) compatibility of structural materials with lead alloys in relation with R& D studies for MEGAPIE. The intent of this symposium was to provide a forum for discussing the most recent results obtained in the frame of the materials research program of the “Groupement De Recherche (GDR) GEDEON". Special emphasis was given to all factors susceptible to affect the durability of structural materials for spallation targets, like irradiation effects under proton and neutron mixed spectrum, Liquid Metal Corrosion (LMC) and Embrittlement (LME). The material research program of GEDEON is a joint CEA-CNRS venture. In 1997, the GDR GEDEON gave opportunity to metallurgists and nuclear physicists of both organizations to collaborate for validating the concept of Pb-Bi spallation targets as a key component for Accelerator-Driven Systems (ADS). Historically, since 1995, GDR GEDEON has promoted ADS, also called Hybrid System, as an option for waste management. The starting point of the material program was the 1st GEDEON Workshop on “Materials For Hybrid Systems" held in Paris in 1997, where reference materials of the 9-12 Cr martensitic steels series were selected: EM10 (9Cr-1Mo) and the modified 9Cr-1Mo, T91 (9Cr-1Mo-V-Nb). However, besides their specific concern for ADS, our studies are also of

  1. Multiphase Production. Representation of Thermodynamic Properties of Methanol by Different Equations of State Production polyphasique. Représentation des propriétés thermodynamiques du méthanol à partir de différentes équations d'état

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    Peneloux A.

    2006-11-01

    quation bipolynomiale à cinquante et un paramètres a bien sûr l'avantage de calculer précisément les tensions de vapeur, les grandeurs volumiques à saturation et hors saturation, les capacités calorifiques, les seconds coefficients du viriel, la vitesse du son, les enthalpies dans les conditions de saturation et hors saturation. Conclusion : Ce travail sur le méthanol a été effectué dans le cadre du programme de recherche EvE (Évacuation des Effluents qui associe l'IFP, Elf et Total avec le soutien du CEP&M (Comité d'Études Pétrolières et Marines sur l'ensemble des recherches liées à la Production Polyphasique : modèles hydrauliques, physico-chimie et thermodynamique, instrumentation /débitmétrie triphasique et pompage polyphasique. Après les progrès récents en modélisation hydraulique (modèle transitoire TACITE, il devient urgent d'améliorer, aussi, nos outils de prédiction du comportement thermodynamique et physico-chimique des divers types d'effluents pétroliers, même les plus complexes, et ceci, dans toutes les conditions de transport, même les plus difficiles, en tenant compte, en particulier, des risques de formation d'hydrates et de leur contrôle, . . . d'où l'intérêt de l'étude du méthanol. La sûreté de fonctionnement des installations de production polyphasique ne saurait être garantie sans la poursuite des diverses recherches en cours sur le comportement des effluents en cours de transport, domaine qui ne peut pas être considéré comme totalement maîtrisé et qui, dans certains cas, peut conduire à des situations potentiellement dangereuses.