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Sample records for biodegradation des hydrocarbures

  1. Hydrocarbons biodegradation in unsaturated porous medium; Biodegradation des hydrocarbures en milieu poreux insature

    Energy Technology Data Exchange (ETDEWEB)

    Gautier, C

    2007-12-15

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  2. Intrinsic aromatic hydrocarbon biodegradation for groundwater remediation; Biodegradation intrinseque des hydrocarbures aromatiques pour la rehabilitation de nappes aquiferes

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    Tiehm, A.; Schulze, S. [Water Technology Center, Karlsruher (Germany)

    2003-08-01

    Intrinsic biodegradation, representing the key process in natural attenuation, is increasingly considered for the remediation of contaminated sites as an alternative to more active measures. In this paper, intrinsic biodegradation is discussed with respect to BTEX and PAH. In the first part, an overview is given summarizing the current understanding of microbial aromatic hydrocarbon degradation and the methods available for the assessment of intrinsic bio-remediation. In the second part, the concept and selected results of a case study are presented. Both aerobic and anaerobic biodegradation of aromatic hydrocarbons contribute to pollutant elimination at contaminated sites such as former manufactured gas plants and tar-oil polluted disposal sites. Intrinsic biodegradation processes usually result in a sequence of redox zones (methanogenic, sulfate-reducing, Fe(III)-reducing, denitrifying, aerobic) in the groundwater plume down-gradient the source of contamination. Methods to assess redox zonation include hydro- and geochemical analysis, measurement of the redox potential, and determination of hydrogen. Biodegradation of target pollutants can be demonstrated by alterations in the pollutant profiles, isotopic fractionation, specific metabolic products, and by microcosm studies with authentic field samples. Microcosm studies in particular are a useful tool to identify degradation mechanisms and to understand the role of specific electron acceptors and redox conditions. In a case study, intrinsic biodegradation was examined at a tar-oil polluted disposal site. Due to the low sorption capacity of the aquifer, decreasing pollutant concentrations with increasing plume length were attributed predominantly to biodegradation. Sulfate reduction and Fe(III) reduction were the most important redox processes in the anaerobic core of tire groundwater plume. Changing pollutant profiles with increasing plume length indicated active biodegradation processes, e.g. biodegradation of

  3. Caracterisation du coefficient de retrodiffusion radar des surfaces d'hydrocarbure: Modelisation et interpretation

    Science.gov (United States)

    Charbonneau, Francois

    La surveillance maritime est un domaine d'applications ou l'interet politique et scientifique croit constamment au Canada. Un des outils privilegies pour la surveillance maritime est l'acquisition de donnees radars, par des systemes aeroportes ou spatio-portes (ERS-2, RADARSAT et Envisat). Par leur grande couverture spatiale, ainsi que leur sensibilite a la geometrie de surface, les donnees radars permettent, en autres, la detection de cibles ponctuelles (bateaux), estimation des vents, detection des glaces de mer, ainsi que la detection de deversement d'hydrocarbure. Les limites et les avantages de la detection d'hydrocarbure par acquisitions de donnees radars sont bien connus, mais il reste encore des lacunes au niveau de l'extraction des parametres physiques d'une surface d'hydrocarbure. Ce projet a pour objectif de caracteriser le coefficient de retrodiffusion radar associe a une surface d'hydrocarbure en milieu oceanique, par l'introduction d'un modele thermodynamique d'attenuation de la surface, au modele theorique radar IEM. Le modele global permet de simuler le comportement de sigma° en fonction des proprietes visco-elastiques, ainsi que de l'epaisseur de la couche d'hydrocarbure et en fonction des parametres d'acquisition radar. Le modele developpe fut valide a partir des donnees SIR-C acquises lors d'experimentations controlees. A partir des informations environnementales et du type d'hydrocarbure, notre modele a permis d'estime le contraste d'intensite avec une precision de 1 a 1,5 dB, a la bande C. Alors qu'a la bande L, l'erreur sur le contraste est d'environ 1,5 a 2 dB sur l'ensemble des mesures. Ce qui est excellant considerant l'heterogeneite des surfaces analysees. Egalement, nous effectuons des analyses multi-polarisees et polarimetriques avec les donnees SIR-C acquises au-dessus de sites experimentaux. II en ressort que le ratio de polarisation VV/HH, ainsi que le facteur d'anisotropie sont des pistes de recherche prometteuses qu'il faudra

  4. Characterization of arene di-oxygenases involved in polycyclic aromatic hydrocarbons biodegradation in Mycobacterium sp. 6PY1; Caracterisation d'arene dioxygenases impliquees dans la biodegradation des hydrocarbures aromatiques polycycliques chez Mycobacterium sp. 6PY1

    Energy Technology Data Exchange (ETDEWEB)

    Kuony, S.

    2005-06-15

    This thesis deals with the bacterial biodegradation of pollutants called polycyclic aromatic hydrocarbons (PAHs). The bacterium Mycobacterium sp. 6PY1 was isolated from a polluted soil for its ability to use pyrene, a 4-ring PAH, as sole source of carbon and energy. To learn about the pyrene metabolic pathway, the identification of the enzymes involved in this process has been undertaken using a proteomic approach. This approach revealed the occurrence of two ring-hydroxylating di-oxygenases in strain 6PY1, which could catalyze the initial attack of pyrene. The goal of this study was to clone the genes encoding the di-oxygenases identified in Mycobacterium sp. 6PY1, over-express these genes in an heterologous system in order to facilitate the purification of the corresponding enzymes, and determine the biochemical and catalytic properties of these enzymes. The pdoA1B1 genes encoding the terminal component of a di-oxygenase were cloned and over-expressed in Escherichia coli. The catalytic properties of this enzyme, called Pdo1, were determined in vivo by measuring the oxidation products of 2- to 4-ring PAHs by gas chromatography coupled to mass spectrometry (GC-MS). Analysis of the selectivity of the enzyme, as determined using GC-MS, showed that Pdo1 preferentially oxidized 3- or 4-ring PAHs, including phenanthrene and pyrene, but was inactive on di-aromatic compounds such as naphthalene and biphenyl. Pdo1 was unstable and was therefore purified in inactive form. The genes encoding a second di-oxygenase component were found in a locus containing two other catabolic genes. The pdoA2B2 genes encoded an enzyme called Pdo2 showing a narrow specificity towards 2- to 3-ring PAHs, and a high preference for phenanthrene. Pdo2 is an a3{beta}3 hexamer, containing [2Fe-2S] Rieske clusters which confer it a characteristic absorbance spectrum. A third set of genes possibly encoding another di-oxygenase was discovered in the genome of Mycobacterium sp. 6PY1. This set is closely

  5. Biodegradation of gasoline in environment: from total assessment to the case of recalcitrant hydrocarbons; Biodegradabilite de l'essence dans l'environnement: de l'evaluation globale au cas des hydrocarbures recalcitrants

    Energy Technology Data Exchange (ETDEWEB)

    Solano-Serena, F.

    1999-11-26

    Because of their massive utilisation, hydrocarbons are major pollutants of soils and aquifers. Biodegradation is a key aspect of the fate of pollutants in the environment. Such knowledge, concerns in particular the intrinsic biodegradability of the products and the distribution in the environment of competent degradative microflora. In this study, a methodology has been developed to assess the aerobic biodegradability of gasoline. It is based on the direct gas chromatographic analysis of all hydrocarbons, after incubation in optimal conditions, of gasoline fractions and of model mixtures. The results demonstrated first the quasi-total biodegradability of gasoline ({>=} 94%). Concerning the distribution in the environment of degradative capacities, even microflora from non polluted sites exhibited a high performance (total degradation rates at least 85%) but were limited concerning the degradation of trimethyl-alkanes, such as 2,2,4-trimethyl-pentane (iso-octane) and 2,3,4-trimethyl-pentane, and of cyclohexane. Samples of polluted sites exhibited more extensive degradative capacities with total degradation in half of the cases studied. Cyclohexane was always degraded by mutualism and/or co-metabolism. Trimethyl-alkanes with quaternary carbons such as iso-octane and/or alkyl groups on consecutive carbons were degraded by co-metabolism but could also support growth of specialized strains. A strain of Mycobacterium austroafricanum (strain IFP 2173) growing on iso-octane was isolated from a gasoline polluted sample. This strain exhibited the capacity to co-metabolize various hydrocarbons (cyclic and branched alkanes, aromatics) and in particular cyclohexane. M austroafricanum lFP 2173 was also able to use a large spectrum of hydrocarbons (n- and iso-alkanes, aromatics) as sole carbon and energy source. (author)

  6. Importance des phénomènes de migration verticale des hydrocarbures Significance of Vertical Migration Phenomea of Hydrocarbons

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    Chiarelle A.

    2006-11-01

    Full Text Available Cette publication a pour but de démonter les mécanismes de migration verticale des hydrocarbures et d'en analyser les conséquences, à partir d'exemples concrets choisis sur les domaines d'activité de la Société Nationale Elf Aquitaine (Production [SNEA (PJ. Les hydrocarbures, huile et gaz, rassemblés en phase individualisée évoluent dans un milieu poreux, fin, généralement mouillé à l'eau. Dans un tel environnement la migration suppose des pressions capillaires élevées. On démontre que cette condition se realise plus particulièrement sur Ies zones hautes fermées où les élements d'hydrocarbures expulses de la roche mère peuvent se rassembler en amas de taille importante, développant une forte poussee d'Archimède. De même le gaz, du fait de sa masse volumique faible par rapport à celle de l'eau, manifestera une grande aptitude à la migration verticale, ce qui conduira souvent à une redistribution verticale des hydrocarbures non conforme au schéma diagénétique classique : présence d'un gisement de gaz en surface et huile en profondeur. Combinés à l'effet Gussow, phénomène de refoulement de l'huile par le gaz hors de la fermeture critique d'une structure, les processus envisagés ici, où tes accidents tectoniques tiennent une place importante, aboutiront généralement à sil: aerer spatialement l'huile et le gaz. Ces transferts semblent s'accompagner fréquemment de modifications dans la composition chimique des huiles : augmentation des teneurs en soufre, en métaux traces, en hydrocarbures aromatiques, et alourdissement des huiles The purpose of this article is ta described the vertical migration mechanisms of hydrocarbons and to analyze their conséquences, on the basis of concrete examples selected in the fields of activities carried on by Société Nationale Elf Aquitaine (SNEA. When hydrocarbons (ai( and gas are gathered in a distinct phase, they evolve in a fine porous medium that is usually water wet. In

  7. Interprétation du contrôle RNO (1975-1982) des polluants chimiques organiques (Hydrocarbures, détergents, organochlores) dans l'eau

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    Marchand, Michel

    1983-01-01

    Un essai d'interprétation des données acquises dans le cadre du Réseau National d'Observation du Milieu Marin (RNO), concernant la surveillance des polluants chimiques organiques dans l'eau, est présenté. Cette interprétation concerne trois classes de paramêtres chimiques : - organochlorés : PCB et lindane - hydrocarbures totaux - détergents anioniques.

  8. Analyse géochimique des hydrocarbures légers par thermovaporisation Geochemical Analysis of Light Hydrocarbons by Thermovaporization

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    Jonathan D.

    2006-11-01

    Full Text Available Le procédé de thermovaporisation est utilisé pour l'extraction et l'analyse des hydrocarbures à point d'ébullition situé à l'intérieur de l'intervalle correspondant aux alcanes C6 à C15; il s'applique également aux roches et aux huiles. La mise en ceuvre est simple et rapide, ce qui rend cette technique utilisable dans certains laboratoires de chantiers d'exploration. Les chromatogrammes de vapeurs montrent une succession de pics, chaque pic correspondant théoriquement à un composant défini, alcane, cyclane ou aromatique; la portion située entre les alcanes n-C, et n-C8 est très typée, mais le reste du chromatogramme apporte également des informations importantes ; l'ensemble donne une définition chimique très fine des hydrocarbures légers présents dans l'échantillon. L'exploitation de ces informations en interprétation géochimique est multiple (pouvoir pétroligène de sédiments, état de maturation, etc.. La faible masse de la prise d'essai nécessaire constitue un intérêt essentiel de la méthode. The method called thermovaporization is used to extract and analyse low boiling point hydrocarbons in the range corresponding to C6-C15; alcanes. Sediments and oils ore examined in the same way. This method is simple and fast to utilize, and for this reason it can be applied in some field exploration laboratories. Chromatograms show a sertes of peaks, each of them theoretically corresponding to a particular composant : alkane, cyclone, arcmatics. The part of the chromatogram between n-C7 n-C8 is very characteristic, but other parts also provide a great deal of information. The total chromatogram gives a very fine chemical definition of the light hydrocarbons in the sample. This information can be used for many geochemical interpretations (hydrocarbon yield potential, state of maturation, etc.. Moreover, the tiny amount of sample thot is necessary is of major interest.

  9. Perméabilité des matériaux élastomériques aux hydrocarbures Permeability of Elastomer Materials to Hydrocarbons

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    Bergault A. M.

    2006-11-01

    Full Text Available L'utilisation de matériaux organiques dans l'industrie pétrolière impose de bien connaître la résistance de ces matériaux lorsqu'ils se trouvent placés au contact d'hydrocarbures. L'étude présente rend compte de la perméabilité des matériaux souples, les élastomères, vis-à-vis d'hydrocarbures se trouvant à l'état liquide à température ambiante. Un grand nombre d'hydrocarbures purs appartenant à des familles de structure chimique différente ont été examinés ainsi que quelques pétroles bruts et fractions pétrolières, essences et gasoils. En règle générale la perméabilité dépend avant tout du caractère « aromatique » de l'hydrocarbure ou du produit pétrolier. En ce qui concerne les élastomères, plus de quinze d'entre eux parmi les plus courants ont été étudiés. Leur perméabilité est essentiellement liée à leur structure, à leur affinité chimique avec les hydrocarbures et, à un degré moindre, à leur formulation, c'est-à-dire à la nature et à la quantité des additifs qui leur sont associés. La température exerce aussi une influence importante sur la perméabilité des élastomères. Le plus souvent, la vitesse de passage des hydrocarbures à travers les élastomères augmente avec la température selon une loi de forme exponentielle type Arrhénius. The strength of organic materials used in the petroleum industry must be well known, especially when they are in contact with hydrocarbons. This article describes the permeability of flexible materials, i. e. elastomers, with regard ta hydrocarbons in the liquid state at ambient temperature. A great many pure hydrocarbons belonging to familles with different chemical structures are examined along with several crude oils and ail fractions, gasolines and gas ails. As a general rule, permeability depends above all on the « aromatic » nature of the hydrocarbon or petroleum product. With regard to elastomers, more than fifteen of the most widely used

  10. Bio-remediation of hydrocarbons in coastal regions; Bioremediation des hydrocarbures en milieu cotier

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    Guyoneaud, R. [IBEAS, LEM - Lab. d' Ecologie Moleculaire - JE 159, 64 - Pau (France)

    2001-07-01

    Coasts are exposed to chronic or accidental pollutions by hydrocarbons. The aim of this study is to show the importance of the microbial layers (stratified sedimentary systems) in the biodegradation of the hydrocarbons. (A.L.B.)

  11. L'hydrodésazotation des distillats issus de la conversion des hydrocarbures lourds Hydrodenitrogenation of Distillates Issuing from the Conversion of Heavy Hydrocarbons

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    Toulhoat H.

    2006-11-01

    Full Text Available L'hydrodésazotation catalytique (HDN est un des points clés de la valorisation des hydrocarbures lourds par leur conversion en carburants. Les coupes lourdes sont riches en azote, et leur conversion produit des distillats eux-mêmes très riches en azote, qui ne pourront être absorbés par une raffinerie classique sans un sévère prétraitement désazotant. Ce problème se pose quel que soit le procédé de conversion mis en oeuvre. On propose donc une analyse de l'HDN comprenant la description des structures azotées rencontrées dans les coupes à traiter, la mise en évidence des réactions à promouvoir, et les règles de choix de catalyseurs et de conditions opératoires en découlant compte tenu des principales déterminantes thermodynamiques et cinétiques. Cette analyse s'appuie sur des résultats de recherche très récents. Elle conduit à la mise en évidence de solutions actuelles au problème posé, et ouvre des perspectives pour des améliorations futures. Catalytic hydrodenitrogenation (HDN is one of the key steps in the upgrading of heavy hydrocarbons by converting them into fuels. Heavy cuts are rich in nitrogen, and their conversion produces distillates that are also very rich in nitrogen, making them unable to be absorbed by a conventional refinery without a severe denitrogenation pretreatment. This problem occurs no matter what conversion process is implemented. Therefore, an analysis of HDN is proposed, including the description of the nitrogen structures encountered in the cuts to be treated, the description of the reactions to be promoted, and the resulting rules for choosing catalysts and operating conditions, in the light of the principal thermodynamic and kinetic constraints. This analysis is based on very recent research results. It leads to the recommending of solutions to the problem at hand and opens up prospects for future improvements.

  12. Exercice interlaboratoire sur les dosages des hydrocarbures dans l'eau et les sédiments Interlaboratory Exercise on Hydrocarbon Measurement in Water and Sediments

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    Bodennec G.

    2006-11-01

    Full Text Available Cet exercice d'intercalibration organisé au niveau national sous l'égide du Réseau National d'Observation portait sur le dosage des hydrocarbures présents dans J'eau et les sédiments. Les résultats sont comparés et discutés en fonction des techniques analytiques employées. Vingt-cinq ,laboratoires ont participé à l'exercice pour le substrat eau et vingt-deux pour le substrat sédiment en suivant dans la majorité des cas un protocole analytique commun à tous les participants. Pour chaque substrat deux niveaux de concentrations en hydrocarbures ont été proposés pouvant correspondre à des cas réels de pollution. La spectrométrie infrarouge (IR et la spectrofluorimétrie ultraviolette (SFUV ont été les techniques les plus utilisées. Les plus faibles dispersions dans les résultats sont relevées pour le dosage des hydrocarbures dans l'eau par SFUV et pour celui des sédiments par IR. Bien que chacune de ces techniques présente une spécificité vis-à-vis de certaines classes d'hydrocarbures, les résultats montrent dans leur ensemble un bon degré d'homogénéité lorsque l'étalon de référence est une coupe pétrolière. La microgravimétrie est la méthode qui présente les plus faibles variabilités dans les résultats, mais semble limitée dans le dosage de teneurs très faibles en hydrocarbures ( This intercomparison exercice organized among French laboratories, under the aegis of RNO (Réseau National d'Observation, concerned the measurement of hydrocarbons present in water and sediments. The results are compared and discussed according to the analytical techniques used. Twenty-five laboratories took part in the project involving water substrate and twenty-two for the part involving sediment substrate. In most cases, the same analytical procedure was followed by all the participants. For each substrate two levels of hydrocarbon concentrations were proposed that might correspond to possible cases of pollution in

  13. Biosurveillance des retombées atmosphériques à l'aide de bryophytes : suivi des hydrocarbures aromatiques polycycliques (HAP) à diverses échelles spatio-temporelles

    OpenAIRE

    Foan, Louise Marie

    2012-01-01

    Les hydrocarbures aromatiques polycycliques (HAP) sont des polluants organiques persistants (POP) émis par les activités humaines suite à la combustion incomplète de la matière organique (industrie, chauffage, trafic routier...). En raison de leur faible taux de dégradation, de leur toxicité, de leur capacité à être transportés sur de longues distances et de leur bioaccumulation dans la matière organique, les HAP font l'objet d'une surveillance atmosphérique (directive cadre européenne 96/62/...

  14. Les hydrocarbures aromatiques polycycliques dans l'environnement : la réhabilitation des anciens sites industriels The Polycyclic Aromatic Hydrocarbons in the Environment : the Former Industrial Sites Remediation

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    Costes J. M.; Druelle V.

    2006-01-01

    Les hydrocarbures aromatiques polycycliques ou HAP peuvent être d'origine naturelle mais ils proviennent principalement des processus de pyrolyse. On peut les retrouver dans les sols de certains anciens sites industriels. Cela peut être le cas des sites d'anciennes usines à gaz. Même si aucune conséquence sur la santé humaine n'a été signalée et même si les risques paraissent virtuels, le principe de précaution rend nécessaire de s'occuper des risques liés à ces anciens sites industriels. Gaz...

  15. Aperçu des connaissances actuelles sur la gestion de la pollution des mangroves par les hydrocarbures

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    Semboung Lang, F.

    2014-01-01

    Full Text Available Overview of current knowledge on management of hydrocarbon pollution in mangroves. Mangrove forests are vital in terms of biomass production and maintenance of the natural balance in coastal areas in the tropics. However, mangroves are subject to pollution from human activities. Oil pollution is one of the causes leading to the decline of mangroves, which represent only 1% of the area of all the world's tropical forests. Several techniques are available for the remediation of oil contaminated areas. Biodegradation appears to be the best suited to mangrove ecosystems. However this technique remains confined to the laboratory. Field tests in situ need to be conducted in order to evaluate the results obtained in the laboratory.

  16. Quelques aspects de la géochimie organique dans la prospection des hydrocarbures Several Aspects of Organic Geochemistry in Prospection for Hydrocarbons

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    Kubler B.

    2006-10-01

    Full Text Available La classification, d'après la composition des huiles brutes, permet maintenant de reconnaître des origines semblables ou différentes. Dans certains cas, les corrélations non seulement entre indices et accumulations, mais entre roches mères et accumulations sont devenues sûres. L'étude, selon un fil logique du devenir des composés de la matière organique vivante, morte, fossilisée puis diagénisée, a permis de préciser l'origine organique des pétroles mais encore de lier la composition de ceux-ci aux types dominants de matière organique des bassins sédimentaires, donc de fixer les conditions de sédimentation, les environnements les plus favorables à l'accumulation et la préservation de matière organique pétroligène. Cependant, la contribution la plus importante de la géochimie organique à l'exploration est certainement d'avoir pu fixer, dans un premier temps, une fourchette de température, puis de température et de durée : le facteur thermo-temporel de naissance de production maximale puis de conservation des hydrocarbures liquides : la fenêtre à huile potentielle. Plus récemment la géochimie des gaz hydrocarburés a pu montrer que cette fenêtre à huile était encadrée par la génération de gaz légers. Ce développement récent remet en valeur des objectifs de prospection abandonnés ou classés sans intérêt. Cependant par essence même la géochimie organique, comme la majorité. des sciences qui utilisent le laboratoire, donne des résultats ponctuels : ceux-ci ne trouvent toute leur signification que si les échantillons géologiques sont bien situés dans la configuration géologique à laquelle ils appartiennent. Organic geochemistry has made great strides, thanks in particular to the range of analytical tools, often in the forefront of technological progress, which have been developed for medical and biochemical research. Classification according to the composition of crude oils now make it possible to

  17. Détermination de coefficients de partage et de limites de solubilité du méthanol dans des mélanges liquides comportant azote et hydrocarbure(s) aux conditions opératoires des unités de fractionnement du gaz naturel

    OpenAIRE

    Courtial, Xavier

    2008-01-01

    Après le traitement du gaz naturel, le méthanol est présent sous forme de traces. Notre objectif est de déterminer les propriétés thermodynamiques des mélanges “hydrocarbure(s) – méthanol“ aux conditions opératoires rencontrées lors du fractionnement du gaz naturel, à hautes et basses températures. En effet, les industries peuvent être pénalisées financièrement lorsque la teneur finale en méthanol dépasse 50 ppm molaire. Pour cela, nous souhaitons connaître les équilibres entre phases aux con...

  18. Rock-Eval 6 Applications in Hydrocarbon Exploration, Production, and Soil Contamination Studies Les applications de Rock-Eval 6 dans l'exploration et la production des hydrocarbures, et dans les études de contamination des sols

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    Lafargue E.

    2006-12-01

    Full Text Available Successful petroleum exploration relies on detailed analysis of the petroleum system in a given area. Identification of potential source rocks, their maturity and kinetic parameters, and their regional distribution are best accomplished by rapid screening of rock samples (cores and/or cuttings using the Rock-Eval apparatus. The technique has been routinely used for about fifteen years and has become a standard tool for hydrocarbon exploration. This paper describes how the new functions of the latest version of Rock-Eval (Rock-Eval 6 have expanded applications of the method in petroleum geoscience. Examples of new applications are illustrated for source rock characterization, reservoir geochemistry, and environmental studies, including quantification. Le succès d'une exploration pétrolière repose sur l'analyse détaillée du système pétrolier dans une zone donnée. L'identification des roches mères potentielles, la détermination de leur maturité, de leurs paramètres cinétiques et de leur répartition sont réalisées au mieux à partir d'examens rapides d'échantillons de roches (carottes ou déblais au moyen de la pyrolyse Rock-Eval. Cette technique a été utilisée en routine pendant une quinzaine d'années et elle est devenue un outil standard pour l'exploration des hydrocarbures. Cet article décrit comment les nouvelles fonctionnalités de la dernière version de l'appareil Rock-Eval (Rock-Eval 6 ont permis une expansion des applications de la méthode en géosciences pétrolières. Des exemples d'applications nouvelles sont illustrés dans les domaines de la caractérisation des roches mères, de la géochimie de réservoir et des études environnementales incluant la quantification et la description des hydrocarbures dans des sols contaminés.

  19. Contribution au dimensionnement des barrages flottants antipollution marine. Etude expérimentale de l'écoulement, à surface libre, de l'eau et de la couche d'hydrocarbure, autour de maquettes de barrages antipollution marine.

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    Abed-Meraïm, Kamel; Joubert, Patrice

    2006-01-01

    alors que la fréquence des catastrophes dues aux naufrages des pétroliers s'est intensifiée ces dernières années, les technologies de récupération des déchets en mer et les méthodes utilisées lors de la lutte contre les dernières marées noires avec plus ou moins de réussite restent moyennement efficaces face à l'ampleur et à la difficulté de la tâche. Constatant que la corrélation entre la conception d'un barrage et ses performances dans la lutte contre la pollution par hydrocarbure est mal c...

  20. LES HYDROCARBURES EN ARGENTINE : RESEAUX, TERRITOIRES, INTEGRATION.

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    Carrizo, Silvina Cecilia

    2003-01-01

    Les réseaux d'hydrocarbures en Argentine ont vécu une restructuration brutale, lors de la réforme de l'Etat des années 1990. La dérégulation des activités et les privatisations des entreprises YPF et Gas del Estado ont induit la re-concentration du secteur, désormais sous l'empire des entreprises étrangères, dont Repsol YPF est le leader. La fédéralisation des ressources au bénéfice des provinces contribue à l'affaiblissent et à la décapitalisation de l'Etat. Ces changements ont entraîné une ...

  1. Evaluation des bassins par modélisation intégrée en deux dimensions des transferts techniques, de l'écoulement des fluides, de la genèse et de la migration des hydrocarbures Basin Evaluation by Integrated Two-Dimensional Modeling of Heat Transfer, Fluid Flow, Hydrocarbon Generation, and Migration

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    Chenet P. Y.

    2006-11-01

    Full Text Available Le modèle de bassin exposé dans cet article décrit les phénomènes physiques et chimiques qui contrôlent la formation d'accumulations commerciales, dans le cadre évolutif d'un bassin sédimentaire affecté par la subsidence : transfert de chaleur, compaction et écoulement de l'eau, génèse des hydrocarbures, migration diphasique de l'eau et des hydrocarbures. Le modèle tient compte des variations de conductivité et des phénomènes thermiques transitoires pour reconstituer les paléo-températures. Des validations quantitatives de la reconstitution des paléo-températures et du modèle cinétique de formation des hydrocarbures peuvent être obtenues par comparaison avec les températures actuelles et les données géochimiques. Les écoulements et les surpressions induits par la compaction sont décrits en couplant une loi de compaction avec la loi de Darcy, classique pour les écoulements de l'eau, en ajoutant un critère de fracturation hydraulique naturelle. Ceci permet de modéliser les pressions anormales dans des séquences deltaïques récentes (delta de la Mahakam, comme dans des bassins liés à des rifts anciens (mer du Nord. Une adaptation de la loi de Darcy aux écoulements diphasiques permet de reproduire la migration primaire et la migration secondaire. En particulier, le modèle permet d'étudier le rôle des pressions anormales et l'influence des failles sur la migration et le piégeage. Nos résultats confirment que les modèles de bassins peuvent contribuer à synthétiser les données géologiques, géophysiques et géochimiques dans un schéma cohérent. En précisant l'évaluation pétrolière, ces modèles constituent une des principales voies pour améliorer l'efficacité de l'exploration. The basin model discussed in this paper describes the physical and chemical phenomena that control the formation of commercial accumulations of hydrocarbons in the moving framework of a subsiding sedimentary basin : heat

  2. Systèmes de surveillance et de contrôle des rejets d'hydrocarbures. Oléomètres Systems of Monitoring and Controlling Hydrocarbon Spills. Oleometers

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    Guigues F.

    2006-11-01

    Full Text Available Le choix de l'appareil à mettre en ceuvre pour doser la teneur en hydrocarbures des eaux de rejet en mer doit obligatoirement être adapté au but poursuivi. Le cahier de charges d'un tel équipement comprend dix caractéristiques : I Plage de mesure : 0 à 100 ppm d'hydrocarbures (possibilité de passer à 000 pp ; 2 Fréquence des mesures : appareil à prélèvement et analyse continus; 3 Qualité des hydrocarbures: actuellement hydrocarbures lourds et adaptabilité future aux produits raffinés; 4 Respect des normes d'analyses : mesure physique échappant aux normes du fait de l'impératif que constitue la rapidité de mesure; 5 Appareil automatique à prélèvement continu : temps de réponse inférieur à 40 s ; 6 Respect de la condition « sécurité intrinsèque »; 7 Appareil n'utilisant pas de solvant auxiliaire (pour respecter le temps de réponse; 8 Précision de la mesure : 10 % de la totalité de la plage de mesure; 9 Maintenance : réduite à sa plus simple expression; 10 Possibilité de branchement d'une « boîte noire » permettant d'effectuer les contrôles à posteriori. L'exposé brosse un tableau de certains appareils, qui ont une certaine vogue ou qui ont permis de progresser dans l'étude de la détection dés hydrocarbures contenus dans les eaux de déballastage des navires pétroliers. Le détecteur à réponse ultra-rapide (DRUR a fait l'objet d'une attention toute particulière car il satisfait aux dix conditions énoncées ci-dessus. Les résultats obtenus en Laboratoire sur des boucles de contrôle sont actuellement confirmés par ceux obtenus sur des pétroliers en service. La disponibilité d'un tel équipement paraît devoir créer les conditions nécessaires pour la mise en vigueur de la Convention de Londres 1973 et contribuera d'une manière significative à la préservation du milieu marin, tout en permettant l'expansion croissante du commerce maritime. The choice of equipment for titrating the amount of

  3. Approche alternative du lavage de sols pollués par des hydrocarbures aromatiques polycycliques : utilisation des cyclodextrines avec procédés de recyclage

    OpenAIRE

    Viglianti, Christophe

    2007-01-01

    Manufactured Gas Plants sites are mostly contaminated by Polycyclic Aromatic Hydrocarbons (PAHs) under the form of hydrophobic coal tar. Soil washing often uses surfactants or organic solvents, which have a significant environmental impact. This PhD work proposes an alternative way, based on seminatural, non-toxic and easily biodegradable cage-like molecules, β-cyclodextrins. They are able to solubilize hydrophobic molecules, as PAHs, thus extracted them from soil. In order to minimize produc...

  4. Application des fluides supercritiques à la production d'hydrocarbures. Exploitation des gisements par récupération assistée et applications diverses : pétrole, sables, schistes, charbons Application of Supercritical Fluids to Hydrocarbon Production. Enhanced Oi Recovery and Miscellaneous Applications: Oil, Tar Sands, Shales, Coals

    OpenAIRE

    Behar E.; Mikitenko P.

    2006-01-01

    Le taux moyen de récupération par drainage naturel des gisements pétroliers atteint à peine 30 %. La récupération assistée désigne l'ensemble des procédés d'exploitation qui permettent d'accroître très sensiblement ce taux. Parmi ces procédés, l'injection de fluides supercritiques joue un rôle prometteur. Les principaux fluides actuellement utilisés sont : le méthane (ou plus généralement les gaz hydrocarbures dits pauvres ), l'azote et enfin le gaz carbonique. Les domaines d'application et l...

  5. Les hydrocarbures aromatiques polycycliques dans l'environnement : la réhabilitation des anciens sites industriels The Polycyclic Aromatic Hydrocarbons in the Environment : the Former Industrial Sites Remediation

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    Costes J. M.

    2006-12-01

    Full Text Available Les hydrocarbures aromatiques polycycliques ou HAP peuvent être d'origine naturelle mais ils proviennent principalement des processus de pyrolyse. On peut les retrouver dans les sols de certains anciens sites industriels. Cela peut être le cas des sites d'anciennes usines à gaz. Même si aucune conséquence sur la santé humaine n'a été signalée et même si les risques paraissent virtuels, le principe de précaution rend nécessaire de s'occuper des risques liés à ces anciens sites industriels. Gaz de France, propriétaire de 467 sites d'anciennes usines à gaz assume l'héritage industriel dans le cadre d'un protocole signé avec le ministère de l'Environnement. Après une étude des sols, une évaluation des risques est réalisée. En fonction des résultats de cette évaluation des risques et de l'usage du site (actuel et prévu, des solutions de traitement peuvent être mises en Suvre. Parmi les techniques applicables aux sols pollués par des HAP, un intérêt particulier s'est porté sur les traitements biologiques, en pleine évolution, qui offrent une solution économique bien adaptée au traitement de grands volumes de sols souillés par une pollution organique moyennement concentrée. Polycyclic aromatic hydrocarbons (PAHs can be found under natural conditions but they can be produced by pyrolysis processes. They can be found in former industrial sites subsoil, especially on Manufactured Gas Plant sites (MGP sites. Gaz de France has inherited the patrimony of former French gas companies on nationalisation in 1946; consequently, Gaz De France is still the owner of 467 of manufactured gas plants. Even if no impact on human health has been detected and even if the risks seem to be virtual, Gaz de France has to prevent any environmental consequence due to the possible presence of residues in the subsoil of the sites: a protocol has been signed with the French Ministry of Environment. Following the investigations on the site, a

  6. Effets d'un hydrocarbure aromatique polycyclique et d'un PCB sur les activités de métabolisation des xénobiotiques de la truite arc-en-ciel (O. mykiss

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    CRAVEDI J. P.

    1998-07-01

    'activité EROD des truites arc-en-ciel aux hydrocarbures aromatiques polycycliques et aux PCB et souligne les possibilités et les limites d'utilisation de cette activité en tant que biomarqueur d'exposition à ces polluants.

  7. Solubilisation des hydrocarbures dans les solutions micellaires Influence de la structure et de la masse moléculaire Solubilization of Hydrocarbons in Micellar Solutions Influence of Structure and Molecular Weight

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    Baviere M.

    2006-11-01

    Full Text Available La solubilisation des hydrocarbures par les solutions de tensio-actifs utilisés pour la récupération améliorée du pétrole est directement liée à l'efficacité interfaciale de ces solutions. D'autant plus élevée que la tension interfaciale entre la phase micellaire et l'huile est plus basse, elle dépend fortement de la nature de l'hydrocarbure. Dans certains cas, celui-ci est responsable de comportements de phase inhabituels. On examine d'abord dans cet article la méthodologie généralement utilisée pour caractériser les propriétés interfaciales des mélanges eau-huile-tensio-actifs. Elle est fondée, à partir des travaux de Winsor et de quelques auteurs après lui, sur le concept d'énergies de cohésion entre les diverses entités moléculaires présentes et sur le rapport entre ces énergies. Cette approche permet d'orienter le choix des paramètres pour optimiser les formulations du point de vue de la solubilisation et de la tension interfaciale. Les comportements de phase d'hydrocarbures modèles, alcanes et alkylbenzènes, sont ensuite comparés et discutés, ainsi que ceux d'huiles brutes de stockage. Il apparaît notamment que, dans les mélanges d'hydrocarbures, le paramètre d'optimisation (ici la masse moléculaire du tensio-actif varie de façon non linéaire avec les proportions du mélange. Les performances obtenues avec les huiles brutes de masses moléculaires voisines dépendent sensiblement de la composition. Cependant l'influence propre de la structure et de la masse moléculaire des différentes espèces n'a pas encore été établie. A cet égard l'huile de Daqing constitue un cas intéressant : la solubilisation est extrêmement faible, bien que les tensions interfaciales soient relativement basses. D'après des essais préliminaires de fractionnement de ce brut, les résines pourraient être à l'origine de ce comportement. La poursuite des travaux vise à préciser l'effet des fractions lourdes des bruts

  8. A Model of Secondary Hydrocarbon Migration As a Buoyancy-Driven Separate Phase Flow Un modèle de migration secondaire des hydrocarbures considéré comme un écoulement en phases séparées régi par la poussée d'Archimède

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    Lehner F. K.

    2006-11-01

    Full Text Available A mathematical model of secondary migration is described which permits the prediction of hydrocarbon migration and accumulation patterns in a sedimentary basin, if source rock expulsion rates and geometrical and hydraulic properties of major carrier systems are known through geological time. In this model, secondary migration is treated as buoyancy-driven, segregated flow of hydrocarbons in hydrostatic aquifers. Lateral, updip migration is conceived as a Boussinesq-type, free-surface flow, with source and sink terms representing supply from source rocks and leakage through cap rocks and faults. This permits a two-dimensional, map-view mathematical description of a three-dimensional, time-dependent secondary migration system. A nine-point finite difference approximation has been developed to minimize numerical dispersion, and upstream-weighting is used to obtain stable solutions. Example computations for simple, single carrier bed structures are presented. L'article décrit un modèle mathématique de migration secondaire prédisant la migration des hydrocarbures et leur accumulation dans un bassin sédimentaire, lorsque les taux d'expulsion des roches mères et les propriétés géométriques et hydrauliques des principaux systèmes de drainage sont connus à l'échelle du temps géologique. Dans ce modèle, la migration secondaire est traitée comme un écoulement des hydrocarbures en phase séparée, contrôlé par la poussée d'Archimède, dans des aquifères hydrostatiques. La migration latérale est considérée comme un écoulement de type Boussinesq, à surface libre, avec des termes sources et puits représentant les apports venant des roches mères et les fuites à travers les couvertures et les failles. Ceci permet une description mathématique bidimensionnelle cartographiable d'un système de migration secondaire tridimensionnel et dépendant du temps. On utilise une approximation type différences finies à neuf points pour minimiser

  9. Les méthodesthermiques de production des hydrocarbures. Chapitre 1 : transfert de chaleur et de masse Thermal Methods of Hydrocarbon Production. Chapter 1 : Heat and Mass Transfer

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    Bia P.

    2006-11-01

    Full Text Available Après un rappel général sur le transfert de chaleur et de masse ainsi que sur les lois de conservation dans les milieux continus, on traite de l'adaptation de ces lois au cas des milieux poreux. On donne ensuite des informations quantitatives sur les grandeurs physiques mises en jeu par les phénomènes de transfert en milieu poreux. After making a general review of heat and mass transfer a well as of laws of conservation in continua, this chapter describes how these laws con be adopted to the case of porous media. Quantitative data are then given on the physical magnitudes brought into play by transfer phenomena in porous media.

  10. Application des fluides supercritiques à la production d'hydrocarbures. Exploitation des gisements par récupération assistée et applications diverses : pétrole, sables, schistes, charbons Application of Supercritical Fluids to Hydrocarbon Production. Enhanced Oi Recovery and Miscellaneous Applications: Oil, Tar Sands, Shales, Coals

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    Behar E.

    2006-11-01

    Full Text Available Le taux moyen de récupération par drainage naturel des gisements pétroliers atteint à peine 30 %. La récupération assistée désigne l'ensemble des procédés d'exploitation qui permettent d'accroître très sensiblement ce taux. Parmi ces procédés, l'injection de fluides supercritiques joue un rôle prometteur. Les principaux fluides actuellement utilisés sont : le méthane (ou plus généralement les gaz hydrocarbures dits pauvres , l'azote et enfin le gaz carbonique. Les domaines d'application et les mécanismes thermodynamiques mis en jeu sont brièvement exposés, les sources de fluides supercritiques disponibles au voisinage des gisements pétroliers sont rapidement répertoriées et certains problèmes d'exploitation évoqués. Outre leur application en récupération assistée, les fluides supercritiques sont également impliqués dans des procédés de raffinage et d'extraction divers. C'est le procédé de désasphaltage de fractions pétrolières lourdes qui, en 1956, a fait l'objet de la première application industrielle exploitant les fortes variations du pouvoir solvant d'un fluide au voisinage de son point critique. Ce procédé connaît, depuis une dizaine d'années, un regain d'intérêt du fait de l'économie d'énergie qu'il permet de réaliser. D'autre part, les schistes bitumineux, les sables asphaltiques et les charbons, sources d'hydrocarbures considérables pour l'avenir, constituent des domaines d'applications potentielles originales des fluides supercritiques. Les procédés spécifiques, pour la plupart en cours de développement au stade pilote, sont passés en revue. The average recovery by natural drainage from oil fields is barely 30%. Enhanced recovery includes all production processes which appreciably increase this rate. Among such processes, supercritical fluid flooding is quite promising. The main fluids now used are methane (or, more generally, so-called leangaseous hydrocarbons, nitrogen and carbon

  11. Prédiction des propriétés volumétriques des hydrocarbures par une translation de volume améliorée Prediction of the Volumetric Properties of Hydrocarbons with an Improved Volume Translation Method

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    Ungerer P.

    2006-12-01

    Full Text Available Ce résumé contient des formules (*** qui ne peuvent s'afficher à l'écran. À la suite des travaux de Péneloux et al. (1982 , plusieurs auteurs (Soreide, 1989; Magoulas et Tassios, 1990; Coniglio, 1993 ont proposé des méthodes de translation de volume pour mieux calculer les masses volumiques des liquides au moyen des équations d'état. Le présent travail vise à améliorer ces prédictions, en particulier dans les conditions des gisements pétroliers (températures jusqu'à 200°C et pressions atteignant 120 MPa, en utilisant l'équation d'état de Peng-Robinson. Comme les méthodes existantes sont parfois incohérentes dans ces conditions (ex. coefficient d'expansion thermique négatif nous avons dû mettre au point une expression originale pour la translation de volume. Dans ce but, nous avons utilisé des mesures de masse volumique à haute pression, et non les masses volumiques du liquide à saturation. On a ainsi étudié des hydrocarbures de plusieurs familles : n-alcanes de C6 à C40 cyclohexane, monoaromatiques de C6 à C12. La translation de volume c obéit approximativement à une dépendance linéaire en température et en masse moléculaire : c(T = (0,023 - 0,00056 MWT + (-34,5 + 0,4666 MW où c est exprimé en cm³/Mol, T en K et MW en g/mol. Avec cette expression, les écarts résiduels moyens à haute pression sont faibles (inférieurs à 3 % pour les hydrocarbures C6 à C13 étudiés. Pour les hydrocarbures plus lourds, les prévisions sont sensibles au choix des paramètres critiques et l'on recommande l'expression: (*** où v(Tref, Pref désigne le volume molaire liquide calculé par l'équation d'état non translatée dans les conditions où la mesure de masse volumique (Pref est disponible. À l'exception de la région péri-critique, la précision reste bonne à basse pression. La nouvelle méthode de translation de volume permet de supprimer les incohérences des méthodes existantes et, à l'opposé de celles

  12. Récupération des hydrocarbures des pieds de bacs provenant de la démixtion des mélanges méthanol-supercarburant. Application du procédé de séparation par coalescence Recovery of Hydrocarbons from Bottoms of Storage Tanks Coming from the Demixing of Methanol/Premium-Gasoline Blends. Application of the Coalescence-Separation Process

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    Hoornaert P.

    2006-11-01

    Full Text Available Une solution technique et économique a été mise au point pour traiter les pieds de bacsprovenant de la démixtion de mélanges méthanol - supercarburant au contact de traces d'eau. Le procédé consiste à provoquer une deuxième démixtion par addition d'eau à la phase à traiter. Les hydrocarbures ainsi relargués sont séparés parfaitement en utilisant un coalesceur à résines oléophiles. Il est ainsi possible de récupérer et de recycler la quasi-totalité des hydrocarbures contenus dans lespieds de bacs . L'effluent aqueux résiduel chargé en alcool peut, soit être recyclé, soit traité par la station de traitement d'eaux de la raffinerie. A technical and economic solution has been developed for processing bottoms of storage tankscoming from the demixing of methanol/premium-gasoline blends in contact with traces of water. The process consists in producing a second demixing by the addition of water to the phase to be processed. The hydrocarbons thus salted out are effectively separated by an oleophilic-resin coalescer. In this way almost all of the hydrocarbons contained in the bottoms of storage tankscan be recovered and recycled. The residual aqueous effluent containing alcohol can either be recycled or processed by the waste-water treatment station of the refinery.

  13. Coke Formation During Hydrocarbons Pyrolysis. Part One: Steam Cracking Formation de coke pendant la pyrolise des hydrocarbures. Première partie : vapocraquage

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    Weill J.

    2006-11-01

    Full Text Available Thermal cracking is always accompanied by coke formation, which becomes deposited on the wall and limits heat transfers in the reactor while increasing pressure drops and possibly even plugging up the reactor. This review article covers undesirable coking operations in steam craking reactors. These coking reactions may take place in the gas phase and/or on the surface of the reactor, with coke being produced during pyrolysis by a complex mechanism that breaks down into a catalytic sequence and a noncatalytic sequence. After a brief description of different experimental set-ups used to measure the coke deposition, on the basis of research described in the literature, the different factors and their importance for coke formation are listed. In particular, we describe the effects of surface properties of stainless-steel and quartz reactors as well as the influence of the cracked feedstock, of temperature, of dilution, of residence time and of the conversion on coke deposition. Some findings about the morphology of coke are described and linked to formation mechanisms. To illustrate this review, some particularly interesting research is referred to concerning models developed to assess coke formation during propane steam cracking. Le craquage thermique est toujours accompagné de la formation de coke qui, en se déposant à la paroi, limite les transferts de chaleur au réacteur, augmente les pertes de charges et même peut boucher celui-ci. Cet article fait le point sur les réactions indésirables de cokage dans les réacteurs de vapocraquage. Ces réactions de cokage peuvent avoir lieu en phase gazeuse et/ou sur la surface du réacteur, le coke étant produit pendant la pyrolyse par un mécanisme complexe qui se décompose en une séquence catalytique et une séquence non catalytique. Après une brève présentation des différents montages expérimentaux utilisés pour mesurer le dépôt de coke, il est mentionné, à partir de travaux de la

  14. Evolution of the Northeastern Arabian Plate Margin and Shelf: Hydrocarbon Habitat and Conceptual Future Potential L'évolution géologique de la plate-forme arabe et de sa marge : répartition des hydrocarbures et concepts pour son potentiel futur

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    Beydoun Z. R.

    2006-11-01

    Full Text Available About 98% of the huge recoverable hydrocarbon reserves of the Arabian Plate are concentrated in the Northeastern Margin Shelf extending from NW Iraq through the Gulf to Central Oman. The plate tectonic evolution of this region is reviewed as background for its enormous hydrocarbon productivity. This is intimately linked to a near-continuous passive margin history and gentle subsidence of an extraordinarily wide epeiric shelf, which allowed repeated regional development of source rocks in large intra-shelf basins frequently in optimal juxtapositional relationships with good regional reservoirs and seals; these events are discussed. Although currently reported reserve figures relate to Mesozoic and Tertiary reservoirs, it is concluded that several pre-Mesozoic regional sources have generated enormous volumes of hydrocarbons, the bulk of which still await discovery in up-dip Paleozoic reservoirs, and that future ultimate recoverable reserves could conceivably double. Près de 98 % des énormes réserves récupérables d'hydrocarbures de la plaque arabique sont concentrés dans la marge nord-est qui s'étend du nord-ouest de l'Irak au centre d'Oman, à travers le Golfe. L'auteur passe en revue l'évolution tectonique de cette région, origine de son énorme productivité pétrolière. La passivité presque continue de cette marge, combinée à l'affaissement progressif d'un plateau épicontinental particulièrement large, a permis le développement local répété de roches mères, au sein du plateau, dans de vastes bassins bénéficiant souvent d'une juxtaposition optimale avec les roches réservoir et roche-couvertures. L'article étudie ces évènements. Si les réserves actuellement prises en compte sont essentiellement d'origine mésozoïque et tertiaire, l'auteur conclut que de nombreuses sources régionales pré-mésozoïques ont généré d'énormes volumes d'hydrocarbures, dont la majeur partie reste à découvrir dans des réservoirs pal

  15. The Importance of Water-Hydrocarbon Phase Equilibria During Reservoir Production and Drilling Operations Nouveaux défis liés à la présence d'équilibres eau-hydrocarbures lors des opérations de production et de forage

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    Zhou H.

    2006-12-01

    érature crée de nouveaux défis pour l'ingénieur pétrolier. Un bref état de l'art des équilibres eau-hydrocarbures est présenté dans un premier temps. À haute température, de grandes quantités d'eau peuvent se trouver dans la phase hydrocarbonée (jusqu'à 10% moles, et à haute pression, on trouvera des quantités non négligeables de gaz dissous dans l'eau. Des mesures de solubilités mutuelles ont donné lieu à un grand nombre de modèles. Étant donné les limites des données expérimentales, les restrictions des modèles sont soulignées. Des études récentes ont indiqué l'intérêt d'utiliser des constantes de Henry pour la prédiction de la solubilité d'hydrocarbures dans l'eau. Les nouveaux défis sont abordés sur la base de quelques publications récentes. L'eau présente en phase hydrocarbonée peut conduire à des dépôts de sels autour du puits, et peut modifier l'estimation de la quantité de gaz en place. Elle peut également donner lieu à une modification des pressions de saturation. La présence d'eau dans les conduites de transport impose un traitement supplémentaire pour éviter la formation d'hydrates. Les hydrocarbures dissous en phase aqueuse peuvent, de leur côté, modifier la composition du fluide, particulièrement lorsque la pression devient très faible. La toxicité de l'eau contenant du H2S ou des aromatiques peut créer de réels problèmes lorsqu'il s'agit de nappes aquifères ou lorsqu'il est question de rejeter les eaux de production. Lors du forage, la présence de gaz dissous dans le fluide de forage (souvent à base d'eau peut représenter un danger réel en causant des éruptions. Une attention particulière doit être portée aux injections de gaz acides dans des réservoirs, car l'effet de ces fluides injectés peut être difficile à prédire. En conclusion, au vu des besoins industriels présentés, des suggestions sont proposées pour des acquisitions de données supplémentaires ou pour améliorer les mod

  16. Action des copolymères éthylène-acétate de vinyle sur la cinétique de nucléation et de croissance des n-paraffines n milieu hydrocarbure. Effect of Vinyl Ethyleneacetate Copolymers on the Nucleation and Growth Kinetics of N-Paraffins in a Hydrocarbon Medium.

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    Petinelli J. C.

    2006-11-01

    Full Text Available On cherche à mettre en évidence le mode d'action des copolymères éthylène-acétate de vinyle sur la cinétique de cristallisation des n-paraffines en milieu hydro-carbure. On s'attache, notamment, à déterminer si l'efficacité de ces additifs est peu ou prou influencée par le nombre de motifs non paraffiniques contenus dans leur chaîne.On décrit deux montages expérimentaux, l'un permettant d'étudier la cinétique de nucléation, l'autre la cinétique de croissance en solution. On observe, grâce à ces deux dispositifs, que la fréquence de germination tridimensionnelle et la vitesse de croissance des n-paraffines diminuent quand la concentration d'acétate de vinyle dans la solution augmente.On établit une relation entre le taux d'acétate de vinyle de la chaîne des copo-lymères et leur efficacité à retarder la cinétique de nucléation. La cinétique de croissance est discutée. On montre l'adsorption très forte de ces additifs sur les faces des cristaux et que le copolymère le plus riche en groupes acétate de vinyle est celui qui retarde le plus la cinétique de nucléation et de croissance des n- paraffines. An effort is made ta détermine how vinyl ethyleneacetate copolymers effect thé crystallization kinetics of n-paraffins in a hydrocarbon medium. In particular, research was done ta see if thé effectiveness of such additives is in thé least bit influenced by thé number of non-paraffinic patterns contained in their chain.Two expérimental assemblies are described, one for investigating nucléation kinetics, thé other growth kinetics in solution. These two devices are used ta observe thot thé theee-dimensional germination fréquency and growth rate of n-paraffins decrease as thé vinyl-acétate concentration in thé solution increases.A relationship is established between thé vinyl-acétate ratio of thé copolymer chain and thé effectiveness of thé copolymer in delaying thé nucléation kinetics. Growth kinetics

  17. Dislocational Rock Mechanisms As a Basis for Seismic Methods in the Search for Hydrocarbons La géomécanique de dislocation en tant que base des méthodes sismiques de la recherche des hydrocarbures

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    Pissetski V. B.

    2006-11-01

    exploration with the best objectivity. L'analyse des données géologo-géophysiques, en premier lieu, nous conforte dans l'idée de la faiblesse et de l'insuffisance des conceptions classiques du milieu sédimentaire continu stratifié et, en deuxième lieu, permet d'avancer une série d'idées physiques clés. La logique générale de la formulation de la conception proposée dans ce travail peut être présentée de la façon suivante : - le caractère discret nettement exprimé du processus de sédimentation permet d'affirmer qu'au moment des changements de cycles (pauses ou des événements sédimentaires dans le milieu, il se forme des couches fines ou des surfaces qui, plus tard, constituent des structures régulières de défaut de solidité ; - les changements de charge gravitationnels ou tectoniques mettent en action des mécanismes de destruction dont le développement régulier conduit à passer d'un système continu stratifié avec défaut à un système discret ; - le mécanisme de destruction discret est un processus final : chaque élément discret est limité dans l'espace par des surfaces horizontales et verticales de rupture de la continuité (dislocations atteignant un empilement critique final doué de la faculté d'un haut degré de réaction à n'importe quelle modification du bilan des charges mécaniques. Si du point de vue de cette conception, on effectue une analyse des données factuelles (affleurements et puits, on peut voir une concordance objective entre la structure de fissuration réelle et les principales limites temporelles et événementielles du processus de sédimentation. Les principales règles de la mécanique de destruction des milieux à défauts sont bien reconstitués en condition de laboratoire sur des modèles physiques fabriqués selon le principe du remplissage successif de la matière par la méthode couches sur couchesavec des arrêts pour la cristallisation. L'analyse théorique de l'état de contraintes des milieux discrets

  18. Influence de la Bioturbation sur l'Activité Dénitrifiante dans des Sédiments Marins Côtiers. Effet d'un Apport Exogène de Matière Organique: les Hydrocarbures

    OpenAIRE

    Gilbert, Franck

    1994-01-01

    L'objectif principal de ce travail était de mettre en évidence l'influence de la bioturbation induite par le macrobenthos sur la dénitrification dans un sédiment marin soumis à un apport ponctuel massif de matière organique (hydrocarbures). Deux types d'expérimentations complémentaires ont été réalisées: - In vitro, pour étudier les effets d'une population de Polychètes galéricoles Nereis diversicolor, - In situ (golfe de Fos) afin de mettre en évidence l'influence de la macrofaune autochtone...

  19. Enhanced Oil Recovery by a Horizontal Well Located Inside a Polymer Flood Pilot Récupération assistée des hydrocarbures par forage horizontal à l'intérieur d'un pilote d'injection de polymère

    Directory of Open Access Journals (Sweden)

    Foxonet F.

    2006-11-01

    configuration à 7 points inversée comportait un injecteur central entouré de 6 puits producteurs situés à 400 m de distance. On a procédé à l'injection d'une solution de polymère (de 1977 à 1983, puis d'eau. La section horizontale du puits CR 163 H est située à l'extrémité nord du pilote, à 350 m de l'injecteur, et suit à peu près la courbe du banc prévu. Son indice de productivité atteint près de 7 fois la moyenne des puits verticaux voisins. La coupe aqueuse a brusquement diminué en mars 1988, jusqu'en octobre 1988, puis s'est établie au même niveau que dans les puits environnants. Ce fait est manifestement dû au banc d'hydrocarbures créé par l'injection de polymère, qui fait du puits CR 163 H un outil efficace pour ce que l'on pourrait appeler Récupération géométriquement assistée des hydrocarbures .

  20. Effets de pollutions par hydrocarbures sur les capacités de défense d'organismes marins

    OpenAIRE

    Bado Nilles, Anne

    2008-01-01

    Les effets des HAPs, parmi les plus toxiques de la liste de l'Agence de Protection Environnementale Américaine, sont testés in vitro et in vivo sur deux espèces commerciales des Pertuis Charentais (Charente-Maritime, France) : le bar commun, Dicentrarchus labrax, et l'huître creuse, Crassostrea gigas. Cette étude, réalisée dans le cadre du projet européen EROCIPS, recherche de nouveaux descripteurs immunologiques d'une pollution occasionnelle par hydrocarbures. Lors d'expérimentations in vitr...

  1. Bioavailability of Polycyclic Aromatic Hydrocarbons in aquatic ecosystems : influence of natural and anthropic organic matter; Biodisponibilite des hydrocarbures aromatiques polycycliques dans les ecosystemes aquatiques: influence de la matiere organique naturelle et anthropique

    Energy Technology Data Exchange (ETDEWEB)

    Gourlay, C.

    2004-11-01

    Aquatic ecosystems receive micro-pollutants. They also contain organic matter (OM) of natural and anthropogenic origins. The contaminant bioavailability in aquatic media is determined by the interactions between contaminants and OM. This work deals with the influence of organic matter from anthropogenic media on the bioavailability of hydrophobic organic pollutants. Polycyclic Aromatic Hydrocarbons (PAHs) have been used as model contaminants, since they are widely spread in urban media. In anthropogenic media, some OM may be bio-degraded. Up to now, most researches focused on the interactions between contaminants and humic OM that are mostly non-degradable, using physico-chemical characterizations of OM. On the contrary, in this work, the biodegradability of OM was deliberately taken into account. Indeed, we assume that the contaminant affinity for OM evolves during OM biodegradation, so that pollutants may be released in a bio-available form and then may be bond again by biodegradation sub-products. In laboratory evaluation, PAH bioavailability was assessed through the measurements of the bioaccumulation in Daphnia magna. The influence of organic matter on the bioavailability of PAHs and the evolution of this influence along OM bacterial mineralization were proved, as well as the strong binding efficiency of degradation by-products. A model of observed phenomena was elaborated. These observations about urban and natural OM effect were compared to in situ PAH bioavailability measurements in the river Seine basin. In this case, the bioavailability was estimated using Semi-Permeable Membrane Device (SPMD) sampling technique. (author)

  2. Les méthodes thermiques de production des hydrocarbures. Chapitre 5 : Combustion "in situ". Pricipes et études de laboratoire Thermal Methods of Hydrocarbon Production. Chapter 5 : "In Situ" Combustion. Principles and Laboratory Research

    Directory of Open Access Journals (Sweden)

    Burger J.

    2006-11-01

    Full Text Available II existe plusieurs variantes de la combustion in situ, suivant le sens de déplacement du front de combustion, à co-courant ou à contre-courant, et suivant la nature des fluides injectés, air seul ou injection combinée d'air et d'eau. Les réactions de pyrolyse, d'oxydation et de combustion mises en jeu par ces techniques sont discutées, en particulier la cinétique des principaux mécanismes réactionnels, l'importance du dépôt de coke et l'exothermicité des réactions d'oxydation et de combustion. Les résultats d'essais de déplacement unidirectionnel du front de combustion dans des cellules de laboratoire sont présentés et discutés. Enfin on indique les conditions pratiques d'application des méthodes de combustion in situ sur champ. Possible variations of in situ combustion technique ore as follows : forward or reverse combustion depending on the relative directions of the air flow and the combustion front, dry combustion if air is the only fluid injected into the oil-bearing formation, or fixe/woter flooding if water is injected along with air. The chemical reactions of pyrolysis, oxidation and combustion involved in these processes are described. The kinetics of these reactions is discussed as well as fuel availability in forward combustion and the exothermicity of the oxidation and combustion reactions. The results obtained in the laboratory when a combustion front propagates in unidirectional adiabatic tells are described and discussed. This type of experimentation provides extensive information on the characteristics of the processes. Screening criteria for the practical application of in situ combustion techniques are presented.

  3. Les méthodes thermiques de production des hydrocarbures. Chapitre 3 : Injection de fluides chauds. Principes et études de laboratoire Thermal Methods of Hydrocarbon Production. Chapter 3 : Hot Fluid Drive. Principles and Laboratory Research

    OpenAIRE

    Combarnous M.; Sourieau P.

    2006-01-01

    Après avoir indiqué les principes des différents procédés de déplacement ou de stimulation faisant appel à l'injection de fluides chauds, eau liquide ou vapeur d'eau, on détaille les mécanismes physiques mis en jeu par ces procédés en indiquant les facteurs limitant l'application des méthodes étudiées. On donne ensuite les résultats d'une étude comparative de la stabilité de ces déplacements avant d'apporter quelques précisions sur les questions de récupération d'huile et d'efficacité de bala...

  4. Importance économique du transport dans les contraintes énergétiques internationales. Le cas des hydrocarbures Economic Importance of Transportation in International Energy Constraints. the Case of Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Masseron J.

    2006-11-01

    Full Text Available Les nombreuses prévisions publiées pour tenter d'estimer l'offre et la demande d'énergie d'ici la fin du XX' siècle montrent qu'il est nécessaire d'examiner les conditions de transport à grande distance de l'ensemble des ressources énergétiques. Le présent article tente, à partir des scenarios des besoins énergétiques mondiaux, d'analyser à quelles conditions pratiques seront soumis les échanges. L'auteur passe successivement en revue les différents moyens de transport pour chaque type d'énergie et les problèmes qui s'y rattachent. En particulier, il montre l'interdépendance des diverses formes de transport et souligne l'absence d'une véritable coopération dans les échanges internationaux d'énergie. The numerous published forecosts attempting to estimate the supply and demand for energy between now and the end of the 20th century show that an examination must be made of long-distance transportation conditions thot will govern exchanges. The present article is based on scenarios for worldwide energy needs and attempts to onalyze the practical conditions that will govern exchanges. A review is made of different means of transportation for each type of energy and the problems they entail. In porticular, the article shows the interdependence of different forms of transportation and emphasizes the absence of any veritable coopération in international energy exchanges.

  5. Les méthodes thermiques de production des hydrocarbures. Chapitre 3 : Injection de fluides chauds. Principes et études de laboratoire Thermal Methods of Hydrocarbon Production. Chapter 3 : Hot Fluid Drive. Principles and Laboratory Research

    Directory of Open Access Journals (Sweden)

    Combarnous M.

    2006-11-01

    Full Text Available Après avoir indiqué les principes des différents procédés de déplacement ou de stimulation faisant appel à l'injection de fluides chauds, eau liquide ou vapeur d'eau, on détaille les mécanismes physiques mis en jeu par ces procédés en indiquant les facteurs limitant l'application des méthodes étudiées. On donne ensuite les résultats d'une étude comparative de la stabilité de ces déplacements avant d'apporter quelques précisions sur les questions de récupération d'huile et d'efficacité de balayage. Several recovery or stimulation techniques by hot fluid injection (water or steam are described. The mechanisms involved in these techniques are discussed together with the limits in the application of the processes. A study is then detailed of the relative stability of hot fluid displacements. Finally, some information is given on ail recovery and sweep efficiencies.

  6. Coke Formation During Hydrocarbons Pyrolysis. Part Two: Methane Thermal Cracking Formation de coke pendant la pyrolyse des hydrocarbures. Deuxième partie : pyrolyse du méthane

    Directory of Open Access Journals (Sweden)

    Billaud F.

    2006-11-01

    Full Text Available Part one of this article dealt with coking in a steam cracking furnace. In this process, coke deposition is a very complex phenomenon due to the number of parameters involved. Nevertheless, for this process, coke deposition is a secondary reaction which does not affect steam cracking yields. It is completely different for methane thermal cracking. Coke is one of the main products of this reaction. Part two of this article deals with coke deposition on the walls of the reactors used for methane thermal cracking. After a brief description of the different set-ups used to study coke deposition, the main parameters involved are listed. The importance of temperature, conversion, type of diluent, and hydrocarbon partial pressure will be enhanced. To conclude, two approaches to the mechanism are proposed to explain coke formation during methane thermal cracking. La première partie de cet article faisait le point sur les réactions indésirables de cokage dans les réacteurs de vapocraquage : dans le cadre de ce procédé, la formation de coke est un phénomène complexe du fait du nombre important de paramètres mis en jeu. Toutefois, pour ce procédé, la réaction de formation du coke à la paroi des réacteurs est une réaction secondaire qui n'affecte pas les rendements de vapocraquage. Ceci est complètement différent dans le cas de la pyrolyse thermique du méthane, procédé pour lequel le coke est un produit principal et indésirable de la réaction. La seconde partie de cet article est consacrée plus particulièrement à la formation du coke, lors de la pyrolyse du méthane et présente les principaux résultats expérimentaux décrits dans la littérature. Parmi les différents montages expérimentaux utilisés pour mesurer le dépôt de coke, il est mentionné, à partir des travaux de la littérature, les 2 techniques suivantes : - la technique de la paroi chaude, - la technique du fil chaud. Pour la première technique, les montages exp

  7. Contribution à la mise au point de méthodes d'évaluation des sédiments, contaminés par les hydrocarbures aromatiques polycycliques, en fonction de la teneur en matière organique des sédiments (1er Juillet 1998 - 1er Juillet 2001 ). Synthèse des travaux

    OpenAIRE

    Pavillon, J-f; Quiniou, Francoise; Caisey, Xavier; Menasria, R.

    2003-01-01

    Les résultats présentés dans cette synthèse reprennent en partie ceux présentés séparément par les deux laboratoires marins : le laboratoire de Physiologie des êtres marins de l'Institut océanographique de Paris et l'antenne brestoise du Département Chimie des polluants de la Direction de l'Environnement Littoral de l'Ifremer, dans les rapports de juillet 99, juillet 2000 et octobre 2002 complétés par des résultats obtenus de juillet 2000 à juillet 2001. L'objectif principal du programme deva...

  8. Radio-induced oxidation of n-paraffins for obtaining biodegradable detergents; L'oxydation radioinduite des n-paraffines pour l'obtention de detergents biodegradables

    Energy Technology Data Exchange (ETDEWEB)

    Puig, J.R.; Laizier, J.; Blin, M.F.; Marchand, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1968-07-01

    N-paraffins oxidation is a feasible way to obtain biodegradable detergents. This reaction can be radio-initiated and it proceeds by a branched chain mechanism, with an induction pseudo-period. A suitable analysis of the reaction is allowed by the semi-logarithmic plot of its evolution. Influence of the different parameters of the reaction is studied, results show that the use of radiation for initiating the reaction is of no economical interest. (authors) [French] L'oxydation des n-paraffines est une voie possible d'obtention des detergents biodegradables. Cette reaction, qui peut etre radioinitiee, procede d'un mecanisme en chaine branchee et presente une pseudoperiode d'induction. La representation semi-logarithmique de l'avancement de la reaction permet une analyse commode de celle-ci. L'influence des differents parametres est etudiee. Les resultats montrent que l'utilisation du rayonnement pour l'initiation de la reaction est sans interet economique. (auteurs)

  9. Élimination des micropolluants par les stations d’épuration domestiques Removal of micropollutants by wastewater treatment plants

    Directory of Open Access Journals (Sweden)

    CHOUBERT, Jean-Marc ; POMIES, Maxime ; MARTIN-RUEL, Samuel ; BUDZINSKI, Hélène ; MIEGE, Cécile ; WISNIEWSKI, Christelle ; COQUERY, Marina

    2012-12-01

    Full Text Available Produits industriels, détergents, hydrocarbures, pesticides, médicaments : les stations d'épuration domestiques sont-elles efficaces pour éliminer toutes les substances chimiques issues des activités humaines retrouvées dans les milieux aquatiques? Cet article présente les principales connaissances récemment acquises relatives au comportement et au devenir des micropolluants dans les différentes filières de traitement des eaux ainsi que les perspectives d'amélioration des procédés.Domestic wastewater treatment plants were not designed for micropollutants removal. They perform substantial removal of several micropollutants, mainly by sorption process onto biological sludge and by biodegradation from the liquid phase for some substances. This article presents the main recent advances on the fate of micropollutants through primary, secondary and tertiary treatment processes. It also addresses research in progress for the optimization of micropollutants removal.

  10. Etat actuel et avenir de l'industrie pétrolière d'extraction. Exposés présentés lors de la journée d'ouverture et la séance de clôture du Colloque international sur les Techniques d'Exploration et d'Exploitation des Hydrocarbures. Paris, 10-12 décembre 1975 Present State and Future of the Petroleum Extraction Industry. Talk Presented During the Opening Day and the Closing Session of the International Symposium on Hydrocarbon Exploration, Drilling and Production Techniques. Paris, 10-12 December 1975

    Directory of Open Access Journals (Sweden)

    Piketti G.

    2006-11-01

    Full Text Available Ce document reprend les exposés et les discussions qui ont suivi, présentés lors de la journée d'ouverture et la séance de clôture du Colloque International sur les Techniques d'Exploration et d'Exploitation des Hydrocarbures organisé à Paris du 10 au 12 décembre 1975 par l'Association de Recherche sur les Techniques d'Exploitation du Pétrole (ARTEP et le Comité d'Études Pétrolières Marines (CEPM. Les communications techniques de ce colloque ont été publiées dans deux ouvrages(' consacrés respectivement - à l'exploitation des gisements. Méthodes de récupération assistée. Techniques de production ; - et au forage et à la production en mers profondes. This article contains the talks and ensuing discussions presented during the opening day and the closing session of the International Symposium on Hydrocarbon Exploration, Drilling and Production Techniques organized in Paris from 10 ta 12 December 1975 by the Association de Recherche sur les Techniques d'Exploitation du Pétrole (ARTEP and the Comité d'Études Pétrolières Marines (CEPM. The technical papers presented at this symposium have been published in two volumes (2 on the following respective topics - Reservoir Engineering. Enhanced Recovery Methods. Production Techniques; - Drilling and Production in Deep Water.

  11. Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Fayolle-Guichard, F.

    2005-04-01

    Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

  12. Caractérisation et origine des métaux traces, hydrocarbures aromatiques polycycliques et pesticides transportés par les retombées atmosphériques et les eaux de ruissellement dans les bassins versants séparatifs péri-urbains.

    OpenAIRE

    Lamprea, Katerine

    2009-01-01

    Depuis une trentaine d'années, les eaux de ruissellement sont considérées comme une source importante de pollution des milieux naturels en raison de leur concentration élevée en micropolluants. Les dépôts atmosphériques, l'érosion des surfaces imperméables (toitures, chaussées, trottoirs et parkings) et le lessivage des dépôts générés principalement par le transport, les chauffages et les industries sont les principales sources identifiées. L'objectif du travail présenté dans ce mémoire est d...

  13. Histoire diagénétique d'une série gréseuse de mer du Nord. Datation de l'introduction des hydrocarbures Diagenetic History of a Sandstone Series of North Sea. Dating the Implantation of Hydrocarbons

    Directory of Open Access Journals (Sweden)

    Sommer F.

    2006-11-01

    Full Text Available L'étude pétrographique et minéralogique d'un réservoir jurassique de mer du Nord permet de mettre en évidence trois stades diagénétiques successifs qui se manifestent chacun par des évolutions minéralogiques spécifiques. Le dernier stade est contemporain de la mise en place de l'huile et des eaux salées. Celles-ci provoquent la néogenèse d'illite et l'illitisation de la dickite élaborée pendant l'enfouissement du réservoir. Des datations absolues par la méthode K/A effectuées sur ces illites donnent un âge lutétien moyen pour la mise en place de l'huile et des eaux salées. A petrographic and mineralogical study of a Jurassic reservoir in the North Sea reveals three successive diagenetic stages, each having a specific mineralogical evolution. The last stage is contemporary with the implantation of oil and salt water. This water has coused the neogenesis of illite and the illitization of the dickite that formed during the burial of the reservoir. Absolute dating of these illites by the K/A method reveals a Middle Lutetian age for the implantation of oil and salt water.

  14. Development of a test system for the determination of biodegradability in surface waters; Entwicklung eines Testsystems fuer die Pruefung des biologischen Abbaus in Oberflaechengewaessern

    Energy Technology Data Exchange (ETDEWEB)

    Kalsch, W.; Knacker, T.; Robertz, M.; Schallnass, H.J.

    1997-04-01

    The study presented here describes the development of a laboratory test system for the determination of aerobic biodegradability of substances at low concentrations in surface water. It was aimed to prepare a draft guideline for a biodegradation simulation test according to OECD format. The experimental approach was based on a literature study conducted within the frame of this project. Further useful information on the possible test design was derived from the German BBA guideline 5-1. Natural water and sediments were collected. Radiolabelled Lindane or 4-Nitrophenol was added. The test vessels (reactors) were aerated and incubated under controlled conditions for up to 92 days. The results showed biological stability of the sediment/water systems even without addition of nutrients and adherence to non-reducing conditions. Mineralisation of 4-Nitrophenol was influenced by the sediment type, the method of aeration and temperature. Factors affecting the mineralisation of Lindane were the method of application and again, the sediment type and temperature. Considerable amounts of the radioactivity were bound to the sediment and were to a large extent unextractable. The potential of a reactor to mineralise a test substance could not be correlated with the biological parameters measured. (orig.) [Deutsch] Die vorliegende Studie beschreibt die Entwicklung eines Labortestverfahrens zur Pruefung des aeroben Abbaus niedrig konzentrierter Stoffe in Oberflaechengewaessern. Dabei war es ein Ziel, das Verfahren so weit abzusichern, dass ein Entwurf fuer eine Pruefrichtlinie als Simulationstest im Format der OECD-Richtlinien abgefasst werden konnte. Grundlage fuer die Konzeption war eine zuvoerderst durchgefuehrte Literaturstudie. Hinweise auf ein moegliches Testdesign ergaben sich auch aus der BBA-Richtlinie 5-1. Wasser und Sediment wurden der Natur entnommen und nach Zugabe der radioaktiven Pruefsubstanz Lindan oder 4-Nitrophenol in einem beluefteten Gefaess unter

  15. Etude comparative de tubes en matériaux composites en vue de l'application à l'exploitation des hydrocarbures en mer profonde Comparative Study of Composite-Material Tubes with a View to Their Use for Deep Offshore Hydrocarbon Production

    Directory of Open Access Journals (Sweden)

    Bonavent G.

    2006-11-01

    Full Text Available Les prévisions de développement de la production pétrolière en mer profonde font apparaître de nouveaux besoins en tubes légers et à haute résistance pour les liaisons verticales entre les têtes de puits sous-marines et les plates-formes flottantes, et les conduites immergées par grand fond. Certains matériaux composites peuvent répondre à ces besoins et présentent en outre l'avantage d'une excellente résistance à la corrosion dans l'environnement marin. Toutefois, les choix sont imposés essentiellement par des contraintes d'ordre mécanique. On cherche ici à comparer, par rapport à l'acier, les avantages de deux types de matériaux composites - les composites acier-résine - les composites fibres-résine dont on résume les principales caractéristiques et les domaines d'applications possibles en fonction des spécifications pétrolières Development forecosts for deep offshore petroleum production bring out new needs for light tubes for vertlcaf linksbetween subsea wellheads and floating piatforms as well as for subsea pipelines ut great depths. Some composite materials moy meet such requirements while also hoving the advantoge of high résistance ta corrosion in a marine environment. However, the choices are mainly governed by stresses of a mechanical nature. Compared with steel, this article seeks ta describe the advantages of the following two types of composite materials : (il steel-resin composites, and (ii fiber-resin composites. The leading properties and the possible arecs of application are summed up as a function of petroleum specifications.

  16. Strategic environmental assessment of hydrocarbon development in the maritime estuary and the northwestern Gulf of St. Lawrence; Evaluation environnementale strategique de la mise en valeur des hydrocarbures dans le bassin de l'estuaire maritime et du nord-ouest du golfe du Saint-Laurent

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-15

    The St. Lawrence maritime estuary is the subject of a major geological research project to determine the possible presence of natural gas. Exploration work conducted by the Geological Survey of Canada in 2003 and 2004 revealed the possible presence of hydrocarbons in the estuary's Quaternary geological formations. Several pockmarks resembling chimneys were found, through which small quantities of natural gas escape. Development of the resource was considered, given the basin's proximity to potential markets and transportation infrastructures. This first strategic environmental assessment (SEA) of the maritime estuary and the northwestern Gulf of St. Lawrence covered nearly 29,000 km{sup 2} of marine territory located east of the Saguenay-St. Lawrence Marine Park to the western tip of Anticosti Island. The objective was to better understand the biophysical, social, and economic components that characterize this basin and to draft recommendations concerning the conditions for oil and gas exploration and development. The SEA will be the first study of its kind supervised by the Quebec Ministere des ressources naturelles et de la Faune (MRNF). Exploration was carried out using seismic surveys and exploratory drilling. Development was divided into 3 phases, notably startup, production, and restoration of the production site to its original state. The assessment shows that this is a complex and fragile environment and that many communities depend on activities connected with tourism and commercial fishery. The SEA program will help to ensure all the necessary requirements are met for the sustainable development of the oil and gas resources in this marine environments. refs., tabs., figs.

  17. Élimination des micropolluants par les stations d’épuration domestiques Removal of micropollutants by wastewater treatment plants

    OpenAIRE

    CHOUBERT, Jean-Marc ; POMIES, Maxime ; MARTIN-RUEL, Samuel ; BUDZINSKI, Hélène ; MIEGE, Cécile ; WISNIEWSKI, Christelle ; COQUERY, Marina

    2012-01-01

    Produits industriels, détergents, hydrocarbures, pesticides, médicaments : les stations d'épuration domestiques sont-elles efficaces pour éliminer toutes les substances chimiques issues des activités humaines retrouvées dans les milieux aquatiques? Cet article présente les principales connaissances récemment acquises relatives au comportement et au devenir des micropolluants dans les différentes filières de traitement des eaux ainsi que les perspectives d'amélioration des procédés.Domestic wa...

  18. Biodegradable Polymers

    OpenAIRE

    Isabelle Vroman; Lan Tighzert

    2013-01-01

    Biodegradable materials are used in packaging, agriculture, medicine and other areas. In recent years there has been an increase in interest in biodegradable polymers. Two classes of biodegradable polymers can be distinguished: synthetic or natural polymers. There are polymers produced from feedstocks derived either from petroleum resources (non renewable resources) or from biological resources (renewable resources). In general natural polymers offer fewer advantages than synthetic polymers. ...

  19. Environmental biodegradability of diesel oil: composition and performances of degradative micro-floras; Biodegradabilite du gazole dans l'environnement: composition et performances des microflores degradatrices

    Energy Technology Data Exchange (ETDEWEB)

    Penet, S.

    2004-09-01

    The large use of petroleum products makes them a significant source of pollutants in ground water and soils. Biodegradation studies are therefore relevant either to evaluate possibilities of natural attenuation or define bio-remediation strategies. In this study, the possible relationship between the environmental microflora structures and their capabilities for diesel oil biodegradation was investigated. The degradation capacities, i.e. kinetics and extent of biodegradation, were evaluated in closed batch systems by hydrocarbon consumption and CO{sub 2} production, both determined by gas chromatography. The intrinsic biodegradability of different types of diesel oils and the degradation capacities of microflora from ten polluted and ten unpolluted soils samples were determined. The data showed that: i) diesel oil was biodegradable, ii) n-alkanes were totally degraded by each microflora, the final amount of residual hydrocarbons being variable, iii) polluted-soil samples exhibited a slightly higher degradation rate (80%) that polluted-soil samples (67%) or activated sludge (64%). In order to define the contribution of various bacterial groups to diesel oil degradation, enrichment cultures were performed on hydrocarbons representative from the structural classes of diesel oil: hexadecane for n-alkanes, pristane for iso-alkanes, decalin for cyclo-alkanes, phenanthrene for aromatics. By using a 16S rDNA-sequencing method, the bacterial structures of the adapted microflora were determined and compared to that of the native microflora. A marked effect of the selection pressure was observed on the diversity of the microflora, each microflora harboring a major and specific bacterial group. The degradation capacities of the adapted microflora and the occurrence of genes coding for initial hydrocarbon oxidation (alkB, nahAc, cypP450) were also studied. No clear relationship between microflora genes and degradation performances was noted. This seemed to indicate that

  20. Devenir des hydrocarbures aromatiques polycycliques en station d'épuration

    OpenAIRE

    Bressy, A.

    2006-01-01

    The occurrence and the removal of Polycyclic Aromatic Hydrocarbons (PAH) were investigated in the wastewater treatment plant Seine-Aval. The removal process efficiency was determined at five points across the treatment system, measuring the following PAH concentrations: bound to particulate, bound-dissolved and freely dissolved. Removal percentages throughout the whole processes ranged from 98% for the bound to particulate fraction (microwave extracted), to 47% for the bound to dissolved orga...

  1. Preparer une firme-reseau dans le transport routier des hydrocarbures le cas de TOTAL Madagascar

    Science.gov (United States)

    Razakamanifidiny, Patrick Dany

    2009-12-01

    In a dynamic context, a network firm is more and more suggested in scientific writings as a prevalent strategy to develop several firms in subcontracting link in order to satisfy the needs of their customers asking for products which are complex to manufacture. However, due to lack of sufficient preparation, most of network organizations fail. That's why it seems legitimate to explore an avenue of research on the preparation step of a network firm. How a third intermediary can develop and try out a change process in order to stimulate the commitment of films to organize themselves in network? This study is developed inside the framework of an intervention-research applied to the case of the oil distribution company TOTAL Madagascar. 71 weeks of intervention actions carried out with 27 subcontracting firms of hydrocarbon road transport located to Antananarivo are recorded within this framework. One of the critical elements in the oil distribution in Madagascar is the scarcity of the subcontracting firms of hydrocarbon road transport which are able to meet the required quality criterions. A lack of management standards observed in several small and medium enterprises of hydrocarbon road transport, a growth of the number of tankers accidents, and an insufficiency of individual resources to develop competences constitute the main reasons which explain this scarcity. By this way, a preparation step of a network firm was developed in order to increase the management competences of the subcontracting firms of hydrocarbon road transport, and to develop their capacity of collective learning. This step comes from the evolutionary perspective which consists in elaborating and implementing uprooting, movement and rooting activities related to a change implementation model taking reactions of the participating enterprises into consideration, through a change understanding process from objection to exploration until engagement. The realization of theses activities had been allowed: 44 managers of 27 participating firms to be trained, certified and sensitized with the network firm practice, 78% of the participating firms to be enthusiastic to pass to the creation of a network firm, and the enterprise pivot TOTAL Madagascar to record a significant diminution of the number of tankers accidents which is passed from 10 (77% of the total number of the tankers accidents) at the beginning of the process in 2003 to 5 (36%) at the end of this process in 2005 and to 3 (27%) in 2007. These tangible and positive results seem to prove the commitment of firms participating in the preparation step of the network firm. In this way, it is appropriate to put the hypothesis according to the experience done within the framework of this study that could be considered as a learning trajectory type of the preparation step which efficiently stimulates the intention of the participating firms to be organized in network. This present case, through these results, strengthens the consideration according to the success of the network firm which depends in the efficiency of the change process related to its preparation. Thus, a main scientific contribution of this present step rely on its originality which is the integration of two change models (implementation and understanding) inside the same research conceptual framework. In a managerial side, the essential of this step may be transferable to the other contexts which look upon the determinant role of the researcher acting as a change co-leader. That shows the utility of this step within the framework of a doctorate applied in administration. Keywords: Subcontracting -- Change -- Network firm -- Hydrocarbon Road Transport -- Small and Medium Enterprises

  2. Hydrocarbons for the future; Des hydrocarbures pour l'avenir

    Energy Technology Data Exchange (ETDEWEB)

    Jacque, M.

    2003-09-01

    Because hydrocarbons do not belong to renewable resources (at the human scale) and their geographical distribution is extremely unequal, governments and oil companies are more and more attracted by non-conventional resources. Two of these are treated in this dossier: the first one is the deep sea oil deposits, an already proven and developing resource (status of world exploration, main discoveries, geological context, Girassol field (Angola) and its satellites, technical challenges of production, other deposits (Campos basin, Marlim and Albacora fields)); and the second one is the methane hydrates, the exploitation of which remains highly hypothetical. (J.S.)

  3. Surface Modification of Biodegradable Polymers towards Better Biocompatibility and Lower Thrombogenicity

    OpenAIRE

    Rudolph, Andreas; Teske, Michael; Illner, Sabine; Kiefel, Volker; Sternberg, Katrin; Grabow, Niels; Wree, Andreas; Hovakimyan, Marina

    2015-01-01

    Purpose Drug-eluting stents (DES) based on permanent polymeric coating matrices have been introduced to overcome the in stent restenosis associated with bare metal stents (BMS). A further step was the development of DES with biodegradable polymeric coatings to address the risk of thrombosis associated with first-generation DES. In this study we evaluate the biocompatibility of biodegradable polymer materials for their potential use as coating matrices for DES or as materials for fully bioabso...

  4. Impact des communautés microbiennes sur la dynamique de dégradation de micropolluants organiques au sein d’écosystèmes épuratoires et sur l’expression de leur toxicité

    OpenAIRE

    Braun, Florence

    2012-01-01

    Les activités anthropiques génèrent une contamination à de faibles doses des boues de station d’épuration par des micropolluants organiques persistants tels que les hydrocarbures aromatiques polycycliques (HAP), les polychlorobiphényles et le nonylphénol. Cette étude porte sur la détermination de l’influence des microorganismes au cours de la méthanisation sur le devenir de ces trois familles de micropolluants. Un protocole spécifique a été mis au point pour extraire des microorganismes de le...

  5. 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...

  6. L'evolution thermique de la matière organique des sédiments : applications d'une simulation mathématique. Potentiel pétrolier des bassins sédimentaires de reconstitution de l'histoire thermique des sédiments Thermal Evolution of Organic Matter in Sediments : Application of a Mathematical Simulation. Petrleum Potential of Sedimentary Basins and Reconstructing the Thermal History of Sediments

    OpenAIRE

    Tissot B.; Espitalié J.

    2006-01-01

    Au moyen d'un modèle mathématique, on simule la dégradation thermique de la matière organique des sédiments. Les applications possibles de ce modèle concernent la recherche des zones favorables pour la prospection de l'huile ou du gaz, la détermination de l'époque de formation des hydrocarbures pour la comparer avec l'âge des pièges et celui des couvertures, l'évaluation des réserves ultimes d'un bassin, ainsi que la pyrogénation des schistes bitumineux. Le type de matière organique est repré...

  7. RESULTS OF CORONARY STENTING USING THE STENTS WITH BIODEGRADABLE POLYMER AND ANTIPROLIFERATIVE (BIOLIMUS A9) COATING

    OpenAIRE

    Zeynalov, Rufat; Asadov, D.; M Matini; Mazurova, V.; Gromov, D.; Zakharova, O.; Koledinsky, A.; Iosseliani, D.

    2011-01-01

    The study comprised two groups of patients with coronary artery disease. Then patients from Group 1 received DES with biodegradable coating, and the patients from Group 2 DES with permanent polymer coating. Baseline clinical, historic and angiographic characteristics were comparable in both groups. The rate of restenosis in the mid-term follow up was similar in both groups. The rate of thrombosis was reliably lower in the group of DES with biodegradable polymer coating.

  8. Dosages d'hydrocarbures dans l'eau et le sédiment marins par infrarouge et chromatographie gazeuse sur colonne capillaire Hydrocarbon Titration in Water and Marine Sediments by Infrared Analysis and Gas Chromatography in a Capillary Column

    Directory of Open Access Journals (Sweden)

    Morel G.

    2006-11-01

    Full Text Available Nous avons étudié l'évolution des hydrocarbures pétroliers dans un site confiné, celui de l'Aber-Benoît (Finistère, à la suite de l'accident du super-pétrolier Amoco-Cadiz en mars 1978. Pour ce faire, plusieurs méthodes ont été mises en oeuvre, et tout particulièrement la chromato-graphie gazeuse sur colonne capillaire : le protocole analytique est décrit pour l'eau et pour le sédiment, après optimisation des techniques de filtration, de préconcentration et de fractionnement préalables à la mesure. Il est possible de travailler sur des échantillons de deux litres d'eau de mer ou de cinquante grammes de sédiment, avec des seuils de détection du niveau de la partie par trillion (ppt dans l'eau et de la centaine de ppt dans le sédiment. The evolution of petroleum hydrocarbons was analyzed in a confined site, at Aber-Benoît in the Finistère department, following the accident of the supertanker Amoco Cadiz in March 1978. To do this, several methods were developed, including, in particular, capillary coulumn as chromatography. The analytical procedure is described for water and sediment after optimization of filtering, preconcentrating and fractionating techniques prior to measuring. Analyses can be made with two liters of seawater or fifty grams of sediment, with detection thresholds in parts per trillion (ppt in water and the hundredth of a ppt in sediment.

  9. Sources et impacts potentiels des micropolluants chimiques sur un écosystème littoral exploité: l'exemple des côtes des Charente-Maritime

    Science.gov (United States)

    Miramand, P.; Guyot, T.; Pigeot, J.

    2003-06-01

    Le littoral picto-charentais est une zone à fortes activités économiques liées à l'aquaculture, à la pêche et au tourisme. Toutes ces activités demandent une très bonne qualité des eaux et de l'environnement en général. Or, cette zone littorale est soumise à de nombreux apports de micropolluants: métaux lourds, phytosanitaires, hydrocarbures, organochlorés.... Les sources en sont nombreuses: apports fluviatiles et atmosphériques, rejets diffus et rejets directs. Les risques dus à cette pollution sont multiples que ce soit au niveau dcs organismes, au niveau des écosystèmes ou des consommateurs. De ce fait, les contaminants majeurs (métaux lourds, organochlorés. hydrocarbures aromatiques polycycliques) et leurs impacts éventuels sur les écosystèmes font l'objet de veille environnementale (réseaux de surveillance ou d'observatoires de l'environnement) et de mesures de prévention se traduisant par la définition de normes de rejets ou de contamination décidées à l'échelle européenne.

  10. Le transfert des micropolluants organiques dans la chaîne alimentaire Etat et perspectives de recherche

    Directory of Open Access Journals (Sweden)

    Feidt Cyril

    2000-09-01

    Full Text Available Les hydrocarbures aromatiques polycycliques ont récemment défrayé la chronique à plusieurs reprises. Cet article se propose de faire le point sur les propriétés de ces molécules en vue de donner un aperçu des voies pour la recherche d’outils d’évaluation et de gestion des risques liés à ces molécules. De nombreuses molécules peuvent prétendre appartenir à cette famille. Nous traiterons de celles les plus communément impliquées dans les problèmes de sécurité alimentaire, à savoir la famille des dioxines-furanes ou polychloro-dibenzo-paradioxines/furanes (PCDD/F, celle des composés polychlorés biphényles (PCB et enfin celle des hydrocarbures aromatiques polycycliques (HAP que nous réserverons dans ce texte aux composés non chlorés.

  11. Les exportations des produits manufacturés et convergence du niveau de vie : cas d'un pays exportateur de pétrole

    OpenAIRE

    Bensafta, Kamel Malik

    2014-01-01

    Dans ce papier, nous explorons la relation entre les exportations des produits manufacturés et la croissance du niveau de vie. Nous nous intéressons particulièrement à l'Algérie du fait de son appartenance au groupe de pays mono-exportateurs. Il s'agit de voir dans quelle mesure les exportations hors hydrocarbures peuvent améliorer le niveau de vie en Algérie. Nos résultats montrent la présence d'un effet de seuil. Les effets positifs de l'exportation des produits manufacturés se font sentir ...

  12. Synthesis and study of the mechanisms of action of biodegradable additives for corrosion and scale inhibition in industrial cooling water systems; Mise au point et etude des mecanismes d'action d'additifs biodegradables pour l'inhibition du pouvoir entartrant et corrosif des eaux de refroidissement industrielles

    Energy Technology Data Exchange (ETDEWEB)

    Estievenart, C.

    2003-11-01

    Industrial cooling water systems undergo more and more environmental constraints. The recycling of water increases the risks of scale deposition and corrosion. The use of chemical additives to inhibit these phenomena is necessary. Poly-aspartates are proposed as green multi-functional inhibitors. Polymers of different characteristics have been synthesized by different ways. Their efficiency towards scale deposition and corrosion is determined by electrochemical techniques in different test conditions (composition of the test water, temperature, flow rate, concentration of additive...). Their biodegradability is also evaluated. These poly-aspartates inhibit both nucleation and growth of calcium carbonate crystals, but also corrosion. Their efficiency depends on the characteristics of the polymers and their way of synthesis. The morphology of scale and corrosion deposits is modified in the presence of poly-aspartate. The mechanism of action of poly-aspartates combines adsorption, dispersion, complexation with both iron and calcium ions and insertion in the crystal lattice. (author)

  13. Proceedings of biodegradation

    International Nuclear Information System (INIS)

    This book contains the proceedings of Biodegradation. Topics include:biodegradation using the tools of biotechnology, basic science aspects of biodegradation, the physiological characteristics of microorganisms, the use of selective techniques that enhance the process of microbial evolution of biodegradative genes in nature, the genetic characteristics of microorganisms allowing them to biodegrade both natural and synthetic toxic chemicals, the molecular techniques that allow selective assembly of genetic segments form a variety of bacterial strains to a single strain, and methods needed to advance biodegradation research as well as the high-priority chemical problems important to the Department of Defense or to the chemical industry

  14. An approach to rehabilitation objectives. Example of hydrocarbon polluted sites; Approche des objectifs de rehabilitation. Exemple des sites pollues par des hydrocarbures

    Energy Technology Data Exchange (ETDEWEB)

    Chevallier, B. [Union Francaise des Industries Petrolieres (UFIP), 75 - Paris (France)

    1996-12-31

    The UFIP (French Petroleum Industry Association) studies concerning polluted sites and soils and their rehabilitation are presented: characterization of the admissible maximum fuel or gas oil content in the ground, the issue of time effects, and the risks it may induce for public health; study on the various pollutant impacts on the environment (underground waters, biotope...); approach to the development of a dynamical model describing these phenomena and their influence on man, in order to derive consistent and reasonable decontamination objectives

  15. Prospective des ressources face à la consommation The Outlook for Resources in the Face of Consumption

    Directory of Open Access Journals (Sweden)

    Rutman G.

    2006-11-01

    Full Text Available Cette étude prospective tient compte des données politiques et économiques portées à notre connaissance en septembre 1979. Des événements nouveaux, aujourd'hui imprévisibles, survenant d'ici juillet 1980, pourraient en modifier considérablement certaines des conclusions qui sont rappelées brièvement ici : - le problème d'approvisionnement en hydrocarbures n'est pas un problème d'existence physique des ressources ; - l'offre, compte tenu du contexte socio-politique et de la répartition géogra-phique des hydrocarbures, se situera dans les dix prochaines années très près du niveau actuel des 63 millions de bbl/d ; - les hypothèses faites sur la demande sont plus hasardeuses, l'une d'entre elles (W. J. Levy l'estime pour 1990 à 68,8 millions de bbl/d ; - l'équilibre offre/demande n'est pas réalisé à court terme et il faut dès maintenant, envisager un équilibre de légère pénurie à moyen et long terme ; - la contribution du gaz naturel et des autres hydrocarbures au rétablissement de l'équilibre subit divers handicaps de coûts, de difficulté de transport oude délais de mise en oeuvre ; - ceci implique que le prix du brut ne peut que croître en valeur réelle et que l'exploration-production et le développement d'hydrocarbures non conventionnels constituent le challenge majeur de la prochaine décennie ; - la solution à moyen terme passe par le développement des productions des pays de l'OPEP à condition de leur offrir des développements sociaux et industriels compatibles avec leurs besoins réels. This glance into the future takes into considaration political and economic data brought to our attention in September 1979. New and unpredictable events occurring between now and July 1980 could make considerable changes in the conclusions briefly summed up here: - the problem of hydrocarbon supplies is not a problem of the physical existence of resources; - the supply, in the light of the socio-political context and

  16. Action des pots catalytiques sur les polluants non réglementés How Catalytic Mufflers Act on Unregulated Pollutants

    OpenAIRE

    Degobert P.

    2006-01-01

    L'installation de pots catalytiques sur les véhicules, envisagée essentiellement pour réduire le niveau des polluants actuellement réglementés (oxyde de carbone, hydrocarbures imbrûlés, oxydes d'azote), aura-t-elle des effets bénéfiques ou néfastes sur les polluants non réglementés ? Pour éclaircir cette question, cette étude compare sur des véhicules les plus comparables possibles du point de vue conception et équipements, les émissions des voitures non dépolluées et celles de voitures dépol...

  17. Étude multi-échelles des courbes de désaturation capillaire par tomographie RX

    OpenAIRE

    Oughanem, Rezki

    2013-01-01

    L'injection de tensioactifs est une méthode très appliquée dans le domaine de la récupération améliorée des hydrocarbures. Cependant, son efficacité repose sur la capacité de ces agents chimiques à mobiliser l'huile résiduelle en diminuant la tension interfaciale entre l'huile et l'eau. Des modèles à l'échelle du réservoir calculent l'efficacité de la récupération d'huile résiduelle par injection de solutions contenant des tensioactifs. Les mécanismes physiques pris en compte dans les modélis...

  18. Evaluation du risque d'inflammation des fumées riches dans un milieu confiné sous-ventilé à l'aide de la simulation numérique

    OpenAIRE

    Dong, Huy Quang

    2013-01-01

    Un des objectifs a consisté à développer une étude systématique des caractéristiques d'allumage, depropagation et de combustion massique de combustibles liquides. La ré-inflammation des fumées riches estplus spécialement pris en compte. La recherche porte essentiellement sur les propriétés des feux dans uneenceinte avec ventilation contrôlée, sous ventilée. Les facteurs dominants à la ré-inflammation des fuméesriches est la quantité minimale d'hydrocarbures totaux et la température. Grâce à l...

  19. Biodegradability of Plastics

    Directory of Open Access Journals (Sweden)

    Yutaka Tokiwa

    2009-08-01

    Full Text Available Plastic is a broad name given to different polymers with high molecular weight, which can be degraded by various processes. However, considering their abundance in the environment and their specificity in attacking plastics, biodegradation of plastics by microorganisms and enzymes seems to be the most effective process. When plastics are used as substrates for microorganisms, evaluation of their biodegradability should not only be based on their chemical structure, but also on their physical properties (melting point, glass transition temperature, crystallinity, storage modulus etc.. In this review, microbial and enzymatic biodegradation of plastics and some factors that affect their biodegradability are discussed.

  20. Grey water biodegradability.

    Science.gov (United States)

    Ghunmi, Lina Abu; Zeeman, Grietje; Fayyad, Manar; van Lier, Jules B

    2011-02-01

    Knowing the biodegradability characteristics of grey water constituents is imperative for a proper design and operation of a biological treatment system of grey water. This study characterizes the different COD fractions of dormitory grey water and investigates the effect of applying different conditions in the biodegradation test. The maximum aerobic and anaerobic biodegradability and conversion rate for the different COD fractions is determined. The results show that, on average, dormitory grey water COD fractions are 28% suspended, 32% colloidal and 40% dissolved. The studied factors incubation time, inoculum addition and temperature are influencing the determined biodegradability. The maximum biodegradability and biodegradation rate differ between different COD fractions, viz. COD(ss), COD(col) and COD(diss). The dissolved COD fraction is characterised by the lowest degradation rate, both for anaerobic and aerobic conditions. The maximum biodegradability for aerobic and anaerobic conditions is 86 and 70% respectively, whereas the first order conversion rate constant, k₂₀, is 0.119 and 0.005 day⁻¹, respectively. The anaerobic and aerobic conversion rates in relation to temperature can be described by the Arrhenius relation, with temperature coefficients of 1.069 and 1.099, respectively. PMID:20658309

  1. Biodegradable polymers: emerging excipients for the pharmaceutical and medical device industries.

    Directory of Open Access Journals (Sweden)

    Bhavesh Patel

    2013-12-01

    Full Text Available Worldwide many researchers are exploring the potential use of biodegradable polymerics as carriers for a wide range of therapeutic applications. In the past two decades, considerable progress has been made in the development of biodegradable polymeric materials, mainly in the biomedical and pharmaceutical industries due to their versatility, biocompatibility and biodegradability properties. The present review focuses on the use of biodegradable polymers in various therapeutic areas like orthopedic and contraceptive device, surgical sutures, implants, depot parenteral injections, etc. Biodegradable polymers have also contributed significantly to the development of drug-eluting stents (DES used for the treatment of obstructive coronary artery disease, such as angioplasty. Biodegradable synthetic polymers have potential applications in orthopedic device fixation due to properties that impact bone healing, formation, regeneration or substitution in the human body. The present review also emphasizes areas such as the chemistry of polymer synthesis, factors affecting the biodegradation, methods for the production of biodegradable polymer based formulations, the application of biodegradable polymers in dental implants, nasal drug deliveries, contraceptive devices, immunology, gene, transdermal, ophthalmic and veterinary applications, as well as, the sterilization of biodegradable based formulations and regulatory considerations for product filing.

  2. Biodegradable modified Phba systems

    International Nuclear Information System (INIS)

    Compositions as well as production technology of ecologically sound biodegradable multicomponent polymer systems were developed. Our objective was to design some bio plastic based composites with required mechanical properties and biodegradability intended for use as biodegradable packaging. Significant characteristics required for food packaging such as barrier properties (water and oxygen permeability) and influence of γ-radiation on the structure and changes of main characteristics of some modified PHB matrices was evaluated. It was found that barrier properties were plasticizers chemical nature and sterilization with γ-radiation dependent and were comparable with corresponding values of typical polymeric packaging films. Low γ-radiation levels (25 kGy) can be recommended as an effective sterilization method of PHB based packaging materials. Purposely designed bio plastic packaging may provide an alternative to traditional synthetic packaging materials without reducing the comfort of the end-user due to specific qualities of PHB - biodegradability, Biocompatibility and hydrophobic nature

  3. Green and biodegradable electronics

    OpenAIRE

    Mihai Irimia-Vladu; Eric. D. Głowacki; Gundula Voss; Siegfried Bauer; Niyazi Serdar Sariciftci

    2012-01-01

    We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials sugg...

  4. Effets de contaminations d'embryons et d'adultes de poissons zèbres (Danio rerio) par des PCB et des HAP

    OpenAIRE

    Daouk, Tarek

    2011-01-01

    Les milieux aquatiques constituent des réservoirs ultimes pour de nombreux polluants organiques persistants,notamment les polychlorobiphényles (PCB, composés bioaccumulables) et les hydrocarbures aromatiques polycycliques (HAP, composés accumulés dans le sédiment et métabolisés par les vertébrés). Les poissons peuvent être exposés à ces polluants à plusieurs stades de vie, ce qui peut altérer leur intégrité fonctionnelle. Les objectifs de cette thèse étaient d'évaluer les altérations physiolo...

  5. Analyse des besoins des usagers

    OpenAIRE

    KHOUDOUR,L; LANGLAIS,A; Charpentier, C.; MOTTE,C; PIAN,C

    2002-01-01

    Il s'agit d'étendre la surveillance vidéo de l'enceinte du métro vers l'intérieur des rames. Les images captées constituent des prises de vue des événements qui se déroulent à l'intérieur des véhicules afin notamment d'améliorer la sécurité des usagers transportes. Il est possible de mémoriser les images des quelques instants précédant un incident usager, d'analyser ces images en temps différé et de mieux appréhender en temps réel le comportement des usagers face à des événements ou des consi...

  6. Advantages and disadvantages of biodegradable platforms in drug eluting stents

    Directory of Open Access Journals (Sweden)

    Agustina Rodriguez-Granillo, Bibiana Rubilar, Gaston Rodriguez-Granillo, Alfredo E Rodriguez

    2011-03-01

    Full Text Available Coronary angioplasty with drug-eluting stent (DES implantation is currently the most common stent procedure worldwide. Since the introduction of DES, coronary restenosis as well as the incidence of target vessel and target lesion revascularization have been significantly reduced. However, the incidence of very late stent thrombosis beyond the first year after stent deployment has more commonly been linked to DES than to bare-metal stent (BMS implantation. Several factors have been associated with very late stent thrombosis after DES implantation, such as delayed healing, inflammation, stent mal-apposition and endothelial dysfunction. Some of these adverse events were associated with the presence of durable polymers, which were essential to allow the elution of the immunosuppressive drug in the first DES designs. The introduction of erodable polymers in DES technology has provided the potential to complete the degradation of the polymer simultaneously or immediately after the release of the immunosuppressive drug, after which a BMS remains in place. Several DES designs with biodegradable (BIO polymers have been introduced in preclinical and clinical studies, including randomized trials. In this review, we analyze the clinical results from 6 observational and randomized studies with BIO polymers and discuss advantages and disadvantages of this new technology.

  7. Green and biodegradable electronics

    Directory of Open Access Journals (Sweden)

    Mihai Irimia-Vladu

    2012-07-01

    Full Text Available We live in a world where the lifetime of electronics is becoming shorter, now approaching an average of several months. This poses a growing ecological problem. This brief review will present some of the initial steps taken to address the issue of electronic waste with biodegradable organic electronic materials. Many organic materials have been shown to be biodegradable, safe, and nontoxic, including compounds of natural origin. Additionally, the unique features of such organic materials suggest they will be useful in biofunctional electronics; demonstrating functions that would be inaccessible for traditional inorganic compounds. Such materials may lead to fully biodegradable and even biocompatible/biometabolizable electronics for many low-cost applications. This review highlights recent progress in these classes of material, covering substrates and insulators, semiconductors, and finally conductors.

  8. Méthodologie pour la caractérisation des terres de curage de fossés routiers et les filières associées : Application au réseau routier de la Haute-Savoie

    OpenAIRE

    MULLER PERRIAND, Karine; ECOLE NATIONALE DES TRAVAUX PUBLICS DE L'ETAT - ENTPE

    2005-01-01

    Les terres de curage de fossés et de dérasement d'accotements sont considérées comme des déchets potentiellement contaminés par des métaux lourds et des hydrocarbures provenant notamment de la circulation automobile. Les gestionnaires des réseaux routiers, responsables de l'élimination de ces résidus de l'assainissement pluvial routier, ont besoin d'une méthodologie simple et peu coûteuse leur permettant de réaliser un diagnostic rapide de ces matériaux afin de les diriger vers les filières a...

  9. Un aspect du calcul d'erreur sur les réserves en place d'un gisement : L'influence du nombre et de la disposition spatiale des puits One Aspect of Error Computing for Reserves in a Reservoir. Influence of Well Number and Spacing

    OpenAIRE

    Haas A.; Mollier M.

    2006-01-01

    L'erreur sur l'évaluation des réserves en place d'un gisement d'hydrocarbures dépend de trois facteurs : - erreur aux puits sur la détermination des porosités et saturations; - erreur géostatistique d'extension au gisement des mesures effectuées aux puits ; - erreur géométrique d'évaluation de la surface ou du volume du gisement. Dans ce texte nous avons étudié l'influence du nombre et de la distribution des puits sur l'erreur géostatistique dans le cas d'un gisement fictif de forme elliptiqu...

  10. Editorial: Biodegradable Materials

    Directory of Open Access Journals (Sweden)

    Carl Schaschke

    2014-11-01

    Full Text Available This Special Issue “Biodegradable Materials” features research and review papers concerning recent advances on the development, synthesis, testing and characterisation of biomaterials. These biomaterials, derived from natural and renewable sources, offer a potential alternative to existing non-biodegradable materials with application to the food and biomedical industries amongst many others. In this Special Issue, the work is expanded to include the combined use of fillers that can enhance the properties of biomaterials prepared as films. The future application of these biomaterials could have an impact not only at the economic level, but also for the improvement of the environment.

  11. Origine, caractérisation et gestion des boues de l'assainissement pluvial routier et urbain : Point sur les connaissances actuelles et perspectives

    OpenAIRE

    V. Ruban; Clozel, B.; CONIL, P; Durand, C.

    2003-01-01

    Les boues qui s'accumulent dans les bassins de retenue des eaux pluviales doivent être curées pour maintenir ou restituer les fonctions de ces ouvrages. Ces boues sont fréquemment chargées en polluants (métaux traces, hydrocarbures, pesticides) et, de ce fait, elles ne peuvent pas être mises en dépôt sans précautions et leur élimination s'avère souvent problèmatique. Les polluants rencontrés dans les bassins de retenue des eaux pluviales ont pour origine les émissions de gaz, fumées et partic...

  12. Absorbable and biodegradable polymers

    CERN Document Server

    Shalaby, Shalaby W

    2003-01-01

    INTRODUCTION NOTES: Absorbable/Biodegradable Polymers: Technology Evolution. DEVELOPMENT AND APPLICATIONOF NEW SYSTEMS: Segmented Copolyesters with Prolonged Strength Retention Profiles. Polyaxial Crystalline Fiber-Forming Copolyester. Polyethylene Glycol-Based Copolyesters. Cyanoacrylate-Based Systems as Tissue Adhesives. Chitosan-Based Systems. Hyaluronic Acid-Based Systems. DEVELOPMENTS IN PREPARATIVE, PROCESSING, AND EVALUATION METHODS: New Approaches to the Synthesis of Crystalline. Fiber-Forming Aliphatic Copolyesters. Advances in Morphological Development to Tailor the Performance of Me

  13. Life Cycle Assessment of different uses of biogas from anaerobic digestion of separately collected biodegradable waste in France. Final report; Analyse du Cycle de Vie des modes de valorisation energetique du biogaz issu de methanisation de la Fraction Fermentescible des Ordures Menageres collectee selectivement en France. Rapport Final

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-07-01

    In the first part of the study, Gaz de France (GdF) and the French Environment Energy Management Agency (ADEME) wished to identify the best method to use the biogas from anaerobic digestion of separately collected biodegradable waste (bio-waste). Secondly, GdF and ADEME wished to evaluate the strength and weaknesses of the two main different organic recycling: anaerobic digestion (methanization) and composting. The study is based on the life cycle assessment method. The life cycle assessment used for this study consists in quantifying the environmental impacts of all of the activities which are related to the chosen use method. This methodology involves compiling a detailed account of all substances and energy flows removed or emitted from or into the environment at each stage of the life cycle. These flows are then translated into indicators of potential environment impacts. This methodology is based on the international standards ISO14040 and ISO 14044. The life cycle assessment was performed by RDC Environnement. In this study, two questions were treated: - Which is the best valorisation method for biogas produced from the anaerobic digestion of separately collected biodegradable waste: fuel, heat or electricity? ('Biogas' question); - Which is the best treatment for the separately collected biodegradable waste: anaerobic digestion (methanization) or industrial composting? ('Composting' question). The field of the study includes the arrival of the separately collected biodegradable waste at the anaerobic unit as well as the utilisation of the biogas energy and the agricultural use of the digestate from anaerobic digestion. For each biogas utilisation, the environmental impacts of each life cycle stage were considered as well as the impacts that were avoided due to the substitution of the use of non-renewable energy ('conventional' procedures). The modelling of the direct composting of the biodegradable waste was realised taking into

  14. Polymeric Biodegradable Stent Insertion in the Esophagus

    Directory of Open Access Journals (Sweden)

    Kai Yang

    2016-04-01

    Full Text Available Esophageal stent insertion has been used as a well-accepted and effective alternative to manage and improve the quality of life for patients diagnosed with esophageal diseases and disorders. Current stents are either permanent or temporary and are fabricated from either metal or plastic. The partially covered self-expanding metal stent (SEMS has a firm anchoring effect and prevent stent migration, however, the hyperplastic tissue reaction cause stent restenosis and make it difficult to remove. A fully covered SEMS and self-expanding plastic stent (SEPS reduced reactive hyperplasia but has a high migration rate. The main advantage that polymeric biodegradable stents (BDSs have over metal or plastic stents is that removal is not require and reduce the need for repeated stent insertion. But the slightly lower radial force of BDS may be its main shortcoming and a post-implant problem. Thus, strengthening support of BDS is a content of the research in the future. BDSs are often temporarily effective in esophageal stricture to relieve dysphagia. In the future, it can be expect that biodegradable drug-eluting stents (DES will be available to treat benign esophageal stricture, perforations or leaks with additional use as palliative modalities for treating malignant esophageal stricture, as the bridge to surgery or to maintain luminal patency during neoadjuvant chemoradiation.

  15. Quantification des sources de polluants dans un bassin versant séparatif à Nantes : des retombées atmosphériques jusqu'au réseau d'assainissement

    OpenAIRE

    LAMPREA, Diana Katerine; Ruban, Véronique; Deneele, Dimitri

    2009-01-01

    Des polluants tels que les éléments traces métalliques, les hydrocarbures aromatiques polycycliques (HAP) et les pesticides (glyphosate, AMPA et diuron) on été mesurés dans les retombées atmosphériques, les eaux de ruissellement de toiture et les eaux de ruissellement transportées à l'exutoire d'un bassin versant drainé par un réseau d'assainissement séparatif. Les résultats de cette étude ont montré que les matières en suspension, les métaux (zinc, cuivre et plomb) et le glyphosate sont les ...

  16. Comportement des fondations et des ancrages de structures marines sous l'effet de sollicitations cycliques Behavior of Foundations and Anchors for Marine Structures under the Effect of Cyclic Stresses

    Directory of Open Access Journals (Sweden)

    Le Tirant P.

    2006-11-01

    Full Text Available L'exploration et l'exploitation des hydrocarbures en haute mer conduisent à la mise en place d'ouvrages fixes ou flottants de dimensions de plus en plus colos sales, par des profondeurs d'eau sans cesse croissantes, atteignant actuellement 200 à 300 mètres en production, un millier de mètres en exploration. Les fondations des ouvrages pétroliers de production comprennent essentiel-lement- les pieux ou groupes de pieux, battus ou forés; - les fondations superficielles à embase poids. Le comportement des fondations ou ancrages de structures sous l'action des sollicitations cycliques est étudié, en fonction de la nature des terrains, à partir - de mesures et d'observations sur des structures réelles; d'expérimentations sur des modèles en semi-grandeur ou de simulations sur modèles réduits. Les exemples donnés situent la diversité des problèmes rencontrés pour l'instal-lation des ouvrages en haute mer et! l'ampleur des travaux nécessaires pour décrire plus correctement les phénomènes d'intéraction sols-structures mannes sous l'effet des chargements cycliques et transitoires et, par suite, mieux optimiser le dimensionnement des fondations et des ancrages. Exploration and production of hydrocarbons in the high seas lead ta the installation of fixed or floating structures having more and more colossal sizes at constantly increasing water depths which now attain 200 ta 300 meters for production and 1000 meters for exploration. The foundations of ail production structures mainly consist of - pilings or groups of pilings, either driven or drilled; superficial gravity foundations the behovior of foundations or anchors for such structures under the effect of cyclic stresses is examined as a function of the nature of formations, on the basis of - measurements and observations on actual structures, experiments with semi-full-sized models or by simulations with scale models. The examples given illustrate the diversity of the problems

  17. Preparation of a biodegradable oil absorber and its biodegradation.

    Science.gov (United States)

    Yoo, Su-Yong; Daud, Wan Mohd Ashri Wan; Lee, Min-Gyu

    2012-01-01

    The biodegradable oil absorption resin (B-PEHA) was prepared by suspension polymerization, and its preparation was confirmed by Fourier transform infrared analysis. The oil absorption capacities of the prepared B-PEHA were: chloroform 30.88, toluene 19.75, xylene, 18.78, THF 15.96, octane 11.43, hexane 9.5, diesel oil 12.80, and kerosene 13.79 g/g. The biodegradation of the prepared B-PEHA was also investigated by determination of reduced sugar produced after enzymatic hydrolysis, thermogravimetric analysis, and incubation with Aspergillus niger. The biodegradation of B-PEHA was ~18%. PMID:21909668

  18. Impact of biodegradable versus durable polymer drug-eluting stents on clinical outcomes in patients with coronary artery disease: a meta-analysis of 15 randomized trials

    Institute of Scientific and Technical Information of China (English)

    Zhang Yaojun; Tian Nailiang; Dong Shengjie; Ye Fei; Li Minghui; Christos V.Bourantas; Javaid Iqbal

    2014-01-01

    Background Drug eluting stents (DESs) made with biodegradable polymer have been developed in an attempt to improve clinical outcomes.However,the impact of biodegradable polymers on clinical events and stent thrombosis (ST) remains controversial.Methods We searched Medline,the Cochrane Library and other internet sources,without language or date restrictions for articles comparing clinical outcomes between biodegradable polymer DES and durable polymer DES.Safety endpoints were ST (definite,definite/probable),mortality,and myocardial infarction (MI).Efficacy endpoints were major adverse cardiac event (MACE) and target lesion revascularization (TLR).Results We identified 15 randomized controlled trials (n=17 068) with a weighted mean follow-up of 20.6 months.There was no statistical difference in the incidence of definite/probable ST between durable polymer-and biodegradable polymerDES; relative risk (RR) 0.83; 95% confidence interval (CI) 0.62-1.11; P=0.22.Biodegradable polymer DES had similar rates of definite ST (RR 0.94,95% CI 0.66-1.33,P=0.72),mortality (RR 0.94,95% C/0.82-1.09,P=0.43),MI (RR 1.08,95% CI 0.92-1.26.P=0.35),MACE (RR 0.99,95% CI 0.91-1.09,P=0.85),and TLR (RR,0.94,95% CI 0.83-1.06,P=0.30) compared with durable polymer DES.Based on the stratified analysis of the included trials,the treatment effect on definite ST was different at different follow-up times:≤1 year favoring durable polymer DES and >1 year favoring biodegradable polymer DES.Conclusions Biodegradable polymer DES has similar safety and efficacy for treating patients with coronary artery disease compared with durable polymer DES.Further data with longer term follow-up are warranted to confirm the potential benefits of biodegradable polymer DES.

  19. Biodegradation of Polypropylene Nonwovens

    Science.gov (United States)

    Keene, Brandi Nechelle

    The primary aim of the current research is to document the biodegradation of polypropylene nonwovens and filament under composting environments. To accelerate the biodegradat ion, pre-treatments and additives were incorporated into polypropylene filaments and nonwovens. The initial phase (Chapter 2) of the project studied the biodegradation of untreated polypropylene with/without pro-oxidants in two types of composting systems. Normal composting, which involved incubation of samples in food waste, had little effect on the mechanical properties of additive-free spunbond nonwovens in to comparison prooxidant containing spunbond nonwovens which were affected significantly. Modified composting which includes the burial of samples with food and compressed air, the polypropylene spunbond nonwovens with/without pro-oxidants displayed an extreme loss in mechanical properties and cracking on the surface cracking. Because the untreated spunbond nonwovens did not completely decompose, the next phase of the project examined the pre-treatment of gamma-irradiation or thermal aging prior to composting. After exposure to gamma-irradiation and thermal aging, polypropylene is subjected to oxidative degradation in the presence of air and during storage after irradiat ion. Similar to photo-oxidation, the mechanism of gamma radiation and thermal oxidative degradation is fundamentally free radical in nature. In Chapter 3, the compostability of thermal aged spunbond polypropylene nonwovens with/without pro-oxidant additives. The FTIR spectrum confirmed oxidat ion of the polypropylene nonwovens with/without additives. Cracking on both the pro-oxidant and control spunbond nonwovens was showed by SEM imaging. Spunbond polypropylene nonwovens with/without pro-oxidants were also preirradiated by gamma rays followed by composting. Nonwovens with/without pro-oxidants were severely degraded by gamma-irradiation after up to 20 kGy exposure as explained in Chapter 4. Furthermore (Chapter 5), gamma

  20. Dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques Depolluting Exhaust Gases from Diesel Engines by Catalytic Mufflers

    Directory of Open Access Journals (Sweden)

    Goldenberg E.

    2006-11-01

    Full Text Available On présente dans cet article les résultats d'une première série de recherches sur la dépollution des gaz d'échappement des moteurs diesel au moyen de pots catalytiques. L'efficacité des catalyseurs à base de platine pour l'oxydation du monoxyde de carbone et des hydrocarbures imbrûlés a pu être établie par des essais sur banc moteur et sur véhicule. L'emploi de certaines phases actives à base de métaux non nobles permet d'autre part d'abaisser la température de début d'oxydation des particules de suie de 380 à 250 °C environ, avec, entre 250 et 350 °C, élimination de 15 à 20 % des produits piégés. L'essai de divers media filtrants a mis en évidence l'importance des phénomènes d'adsorption des revêtements en alumine et a orienté la recherche vers de nouveaux supports pour filtres catalytiques. This article describes the results of a first series of research on the depollution of exhaust gases from diesel engines by catalytic mufflers. The effectiveness of platinum-base catalysts for the oxidation of carbon monoxide and unburned hydrocarbons was determined by test on an engine test bed and on vehicles on the road. The use of some active non-noble metal phases reduced on the other hand the starting oxidation temperature of soot particulates from 380°C to about 250°C, eliminating 15 to 20% of the trapped products between 250 and 350° C. Tests of different filtering media revealed the importance of adsorption phenomena on alumina coatings and directed research toward new supports for catalytic filters.

  1. Biodegradable micromechanical sensors

    DEFF Research Database (Denmark)

    Keller, Stephan Sylvest; Greve, Anders; Schmid, Silvan;

    The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization of mechani......The development of biopolymers for food packaging, medical engineering or drug delivery is a growing field of research [1]. At the same time, the interest in methods for detailed analysis of biopolymers is increasing. Micromechanical sensors are versatile tools for the characterization...... of biopolymers to microfabrication is challenging, as these polymers are affected by common processes such as photolithography or wet etching. Here, we present two methods for fabrication of biodegradable micromechanical sensors. First, we fabricated bulk biopolymer microcantilevers using nanoimprint lithography...

  2. Biodegradation of biodiesel fuels

    International Nuclear Information System (INIS)

    Biodiesel fuel test substances Rape Ethyl Ester (REE), Rape Methyl Ester (RME), Neat Rape Oil (NR), Say Methyl Ester (SME), Soy Ethyl Ester (SEE), Neat Soy Oil (NS), and proportionate combinations of RME/diesel and REE/diesel were studied to test the biodegradability of the test substances in an aerobic aquatic environment using the EPA 560/6-82-003 Shake Flask Test Method. A concurrent analysis of Phillips D-2 Reference Diesel was also performed for comparison with a conventional fuel. The highest rates of percent CO2 evolution were seen in the esterified fuels, although no significant difference was noted between them. Ranges of percent CO2 evolution for esterified fuels were from 77% to 91%. The neat rape and neat soy oils exhibited 70% to 78% CO2 evolution. These rates were all significantly higher than those of the Phillips D-2 reference fuel which evolved from 7% to 26% of the organic carbon to CO2. The test substances were examined for BOD5 and COD values as a relative measure of biodegradability. Water Accommodated Fraction (WAF) was experimentally derived and BOD5 and COD analyses were carried out with a diluted concentration at or below the WAF. The results of analysis at WAF were then converted to pure substance values. The pure substance BOD5 and COD values for test substances were then compared to a control substance, Phillips D-2 Reference fuel. No significant difference was noted for COD values between test substances and the control fuel. (p > 0.20). The D-2 control substance was significantly lower than all test substances for BCD, values at p 5 value

  3. Les méthodes thermiques de production des hydrocarbures. Injection de fluides chauds. Applications Thermal Methods of Hydrocarbon Production. Injection of Hot Fluids. Applications

    OpenAIRE

    Sourieau P.; Burger J.

    2006-01-01

    Cet article décrit les applications sur champ de l'injection de fluides chauds, et en particulier de l'injection de vapeur. On présente également les aspects technologiques liés à la mise en oeuvre de ces méthodes. This article describes the field applications of hot-fluid injection and in particular steam injection. The technological aspects linked to the implementation of these methods are also described.

  4. Les méthodes thermiques de production des hydrocarbures. Injection de fluides chauds. Applications Thermal Methods of Hydrocarbon Production. Injection of Hot Fluids. Applications

    Directory of Open Access Journals (Sweden)

    Sourieau P.

    2006-11-01

    Full Text Available Cet article décrit les applications sur champ de l'injection de fluides chauds, et en particulier de l'injection de vapeur. On présente également les aspects technologiques liés à la mise en oeuvre de ces méthodes. This article describes the field applications of hot-fluid injection and in particular steam injection. The technological aspects linked to the implementation of these methods are also described.

  5. Caractérisation géostatistique de pollutions industrielles de sols: cas des hydrocarbures aromatiques polycycliques sur d'anciens sites de cokeries

    OpenAIRE

    Jeannée, Nicolas

    2001-01-01

    Estimating polycyclic aromatic hydrocarbons concentrations in soil at former industrial sites poses several practical problems on account of the properties of the contaminants and the history of site : - collection and preparation of samples from highly heterogeneous material, - high short scale variability, particularly in presence of backfill, - highly contrasted grades making the variogram inference complicated. The sampling strategy generally adopted for contamined sites is based on the h...

  6. Diagnostic de sols pollués par des hydrocarbures aromatiques polycycliques (HAP) a l'aide de la spectrophotométrie UV.

    OpenAIRE

    Crone, Magalie

    2001-01-01

    Polycyclic aromatic hydrocarbons (PAHs) were produced by many pyrolitic or combustion processes. They were found in soils, often in high concentrations. Remediation of indu striai sites contaminated by P AHs requires an initial diagnosis of the pollution. In this perspective, an analytical procedure based on UV spectrophotometry was developped and validated with about 80 soil samples. Different exploitation methods of the samples UV spectra enable to develop simple and rapid characterisation ...

  7. Late production of hydrocarbon gases in sedimentary basins: kinetic and isotopic study; Genese tardive des gaz hydrocarbures dans les bassins sedimentaires: etude cinetique et isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Lorant, F.

    1999-06-23

    The thermal decomposition of sedimentary organic matter, or kerogen, within the metagenesis zone (T > 170 deg. C) leads to the formation of large amounts of late gas, mainly composed by methane. The work reported in this dissertation aims at understanding and quantifying the mechanisms of late methane generation and isotopic fractionation. With this purpose, natural samples of Type II and Type III mature kerogens (Ro > 1.3%, H/C < 0.65), were artificially heated in both open (T = 350 to 900 deg. C at 25 deg. C/min) and closed (T = 375 to 550 deg. C with t = 1 to 216 h) systems. For each experiment, mass and atomic (C, H, O) balances were obtained by recovering, fractionating and quantifying the entire pyrolysis effluents. Moreover, the isotopic compositions ({sup 13}C/{sup 12}C ratios) of methane and insoluble residue produced in closed system were measured. These experimental simulations have shown that the amounts of methane generated in an open-pyrolysis system (9 to 40 mg/gC) are systematically inferior to that observed in a closed-pyrolysis system (44 to 68 mg/gC), even after correction of the possible C{sub 2}-C{sub 5} and C{sub 6+} hydrocarbons secondary cracking. This shift, which is larger for Type II kerogens compared to coals and Type II-S kerogens, seems to be correlated with the pyrite content of the samples. Based on the closed-pyrolysis system data, a kinetic scheme, suitable for both Type II and Type III kerogens, was established. It includes three consecutive reactions, whose apparent kinetic parameters do not allow accounting for the corresponding rate constants observed in open system: E{sub 1} = 64.7 kcal/mol and A{sub 1} = 2.58 x 10{sup 15} s{sup -1}, E{sub 2} = 52.8 kcal/mol and A{sub 2} = 5.50 x 10{sup 10} s{sup -1}, E{sub 3} = 55-58 kcal/mol and A{sub 3} = 7.52 x 10{sup 9} s{sup -1}. By extrapolation to geological setting, it was thus predicted that kerogens might generate about 15 mg/gC of late methane between 170 and 200 deg. C. In order to describe more precisely these reactions, additional pyrolysis experiments were performed on an aromatic compound, representative of the chemical structure of mature kerogens: the 1-methyl-pyrene. The data show that the methane is mainly produced during secondary and tertiary mechanisms, following to global succeeding stages: E{sub 1} = 56.7 kcal/mol and A{sub 1} = 8.52 x 10{sup 12} s{sup -1}, E{sub 2} = 49.5 kcal/mol and A{sub 2} 2.48 x 10{sup 9} s{sup -1}. By analogy, it was established that the three reactions of late methane generation, as observed by pyrolyzing mature kerogens, are respectively related to beta-scission, demethylation and cokefaction processes. In other respects, the late methane is characterized by {delta}{sup 13}C values between -36 and -24 0/00{sub PDB} (experimental conditions), and for the Type II kerogen by a reversal of the isotopic fractionation between the gas and its source at the high maturity levels: {delta}{sup 13}C{sub CH4/kerogene} = -10 to +2 0/00{sub PDB}. Such an uncommon {delta}{sup 13}C evolution was not observed during the pyrolysis of the I-methyl-pyrene, the generated methane being, on the contrary, strongly {sup 12}C-enriched compared to its source ({delta}{sup 13}C{sub CH4/1-MPy} = -35 to -19 0/00{sub PDB}). Nevertheless, by coupling a model of isotopic fractionation, based on the assumption of strictly kinetically-controlled effects, to the kinetic scheme previously generated, it was shown that the differences of isotopic signature between the model compound and the kerogens are mainly due to highly contrasted precursor effects (i.e. {delta}{sup 13}C of the functional groups from which the methane originates) specific to demethylation processes. Besides the elaboration of a methodology for the acquisition of kinetic, stoichiometric and isotopic parameters specific to the generation of late methane, this work has allowed the validation of a model of isotopic fractionation, especially by emphasizing the synergy between the mechanisms of cracking and the isotopic processes. Following this concept, a general class-compound model for the production and the degradation of oil and gas, including the calculation of the isotopic compositions, was set up. The kinetic scheme, based on that proposed by Behar et at. (1992), comprises 10 first-order reactions whose pre exponential factors (A) are not all the same. The various kinetic and isotopic parameters were determined on the basis of pyrolysis experiments performed on an immature Type II kerogen. The first simulations at low temperature show that this model can reproduce isotopic trends that are consistent with natural observations. However the current uncertainty on the isotopic parameters does not yet allow a confident utilization of the model to predict the {delta}{sup 13}C of hydrocarbon gases is the geological conditions. (author)

  8. Coke Formation During Hydrocarbons Pyrolysis. Part One: Steam Cracking Formation de coke pendant la pyrolise des hydrocarbures. Première partie : vapocraquage

    OpenAIRE

    Weill J.; Broutin P.; Billaud F.; Gueret C.

    2006-01-01

    Thermal cracking is always accompanied by coke formation, which becomes deposited on the wall and limits heat transfers in the reactor while increasing pressure drops and possibly even plugging up the reactor. This review article covers undesirable coking operations in steam craking reactors. These coking reactions may take place in the gas phase and/or on the surface of the reactor, with coke being produced during pyrolysis by a complex mechanism that breaks down into a catalytic sequence an...

  9. Bureau of hydrocarbons exploration-production (BEPH) - Monthly information bulletin. December 2006; Bureau exploration-production des hydrocarbures. Bulletin mensuel d'information. Decembre 2006

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-12-15

    This newsletter takes stock of the recent highlights in the domain of hydrocarbons exploration and production in the French territory: mining domain (demands and allocations of research permits and concessions; list of demands under instruction), drilling activity (new drillings, advance of existing exploratory and extension-development drillings); production activity (interventions on wells, crude oil, crude gas, commercialized gas, natural gas-derived hydrocarbons, related products, production shares by company in the Paris and Aquitain basins); underground storage facilities (allocation and extension of concessions). (J.S.)

  10. Détermination de la pollution chimique des baies de Jakarta, Banten, Cilacap (Indonésie). Hydrocarbures, organochlores, métaux

    OpenAIRE

    Martin, Jean-Louis; Marchand, Michel; Le Guellec, Anne-marie; Caprais, Jean-Claude

    1983-01-01

    Analyses of pesticides, polychlorobiphenyls (PCB's) and hydrocarbons have been carried out in sediments and water samples from the bays of Jakarta, Banten and Cilacap. Heavy metals (Hg, Cu, Mn, Zn, Fe, Pb, Cd, Ni, Co and Cr) have been analysed in sediment samples fram the same areas. - Organic pollutants : The results show that for pesticides, PCB and hydrocarbons, in water and in sediments, there is no significant pollution for the bays of Banten, Cilacap and Jakarta. The bay of Bante...

  11. Poly-phase flows in the vicinity of wells in hydrocarbon deposits; Les ecoulements polyphasiques aux abords des puits dans les gisements d`hydrocarbures

    Energy Technology Data Exchange (ETDEWEB)

    Betata, S.A.

    1998-02-13

    During the production phase of an oil reservoir, a pressure drawdown occurs in the near wellbore region. This may lower the pressure below the bubble-point pressure, leading to the appearance of a gas phase, thus decreasing the oil relative permeability and the well productivity. The main goal of this study is the development of an appropriate laboratory procedure and its modeling, so as to derive gas-oil relative permeabilities at conditions representative of the near wellbore region, e.g. for a dispersed gas phase. A set of depressurization tests in porous media are performed for various conditions of pressure gradient and supersaturation. They are interpreted using a model relating the gas saturation to the supersaturation, as well as the nucleation rate J. Gas-oil relative permeabilities and average gas saturation versus time are measured. Oil relative permeabilities are found to be a function of both the gas saturation and the supersaturation. In addition to that, above a given threshold pressure drop part of the gas is mobilized. The value of J, obtained from the oil production curve leads to the description of the bubble population, in terms of their number and size. It is shown that oil-phase flow impairment is caused more by a limited number of large bubbles rather than by the presence of regularly distributed small ones. The procedure thus established allows the description of the behavior of oil and gas, not only above the critical gas saturation (defined as the saturation above which the gas phase becomes continuous), but also in the early stage of the nucleation, when the gas, even in a dispersed form, can flow depending on the applied pressure gradient. (author) 39 refs.

  12. Study of saturated hydrocarbons transport through MFI zeolitic membranes; Etude du transport d`hydrocarbures satures dans des membranes zeolithiques de structure MFI

    Energy Technology Data Exchange (ETDEWEB)

    Millot, B.

    1998-12-22

    The main goal of this work was to characterize and model alkanes transport through (MFI) zeolitic membranes. This work was divided in two steps. First, a characterization of alkanes sorption equilibria in MFI type zeolite was necessary. The measurements of sorption isotherms and Temperature Programmed Desorption allowed us to deduce: capacity of absorption, variations of the sorption isosteric enthalpy and entropy. A model using two different types of sorption sites in the zeolite was used to explain the presence of several interaction types between molecules and zeolite. The model showed the importance of entropy on the localization of the molecules in the zeolitic channels. Moreover, we studied the permeation of alkanes in zeolitic membranes. The results showed promising properties for the separation of linear and branched alkanes. Even if the behavior is very intricate, the use of the Generalized Maxwell-Stefan equations gave an access to the diffusivities of the linear and mono-branched alkanes. The preliminary modeling of the permeation mixtures results was also obtained. (author) 280 refs.

  13. Diagnosis of soils polluted by aromatic hydrocarbons; Diagnostic de sols pollues par des hydrocarbures aromatiques polycycliques (HAP) a l'aide de la spectrophotometrie UV

    Energy Technology Data Exchange (ETDEWEB)

    Crone, M.

    2000-01-28

    Polycyclic aromatic hydrocarbons (PAHs) were produced by many pyrolytic or combustion processes. They were found in soils, often in high concentrations. Remediation of industrial sites contaminated by PAHs requires an initial diagnosis of the pollution. In this perspective, an analytical procedure based on UV spectrophotometry was developed and validated with about 80 soil samples. Different exploitation methods of the samples UV spectra enable to develop simple and rapid characterisation tools. A PAH UV index is proposed for the estimation of global PAH concentration. A more accurate exploitation of the spectra gives an indication on the presence or the absence of some individual PAH like benzo[a]pyrene. A maturity index based on a two wavelength approach constitutes an indicator of the potential evolution of soil contamination in natural conditions. Laboratory methodology was adapted to field analyses and a test kit was designed for this purpose. The test duration is 20 minutes. (author)

  14. Filtration d’une huile dopée avec quatre hydrocarbures aromatiques polycycliques (HAP sur des plaques garnies en charbon actif

    Directory of Open Access Journals (Sweden)

    Sidani Marion

    2012-11-01

    Full Text Available Powdered activated carbon is used in oils and fats refining to bleach and purify vegetable oils and fish oils. Actually, this powder makes it possible to detoxify crude fish oils and to eliminate contaminants like PAH, dioxin and PCB. Nevertheless, the powdered activated carbon used is painful because it is pulverulent. Nowadays, producers advise filtration plates filled with this powder. The aim of this study is to check the efficiency of such plates in the PAH elimination and verify the respect of the new 2011 regulation (2 μg/kg for benzo(apyrene, 10 μg/kg for the sum of benzo(apyrene, benzo(bfluoranthene, benzo (aanthracene and chrysene.

  15. Filtration d’une huile dopée avec quatre hydrocarbures aromatiques polycycliques (HAP) sur des plaques garnies en charbon actif

    OpenAIRE

    Sidani Marion; Gaud Marie; Pagès Xavier; Morin Odile; Gouband Morgan; Buchoux Jérôme; Goulet Jérémy; Birot Céline; Galan Virginie

    2012-01-01

    Powdered activated carbon is used in oils and fats refining to bleach and purify vegetable oils and fish oils. Actually, this powder makes it possible to detoxify crude fish oils and to eliminate contaminants like PAH, dioxin and PCB. Nevertheless, the powdered activated carbon used is painful because it is pulverulent. Nowadays, producers advise filtration plates filled with this powder. The aim of this study is to check the efficiency of such plates in the PAH elimination and verify the res...

  16. La Serbie à la croisée des chemins : corridors énergétiques, privatisations et guerre du gaz

    OpenAIRE

    Troude, Alexis

    2011-01-01

    La Serbie, Etat récemment créé, cherche sa place sur un échiquier balkanique en pleine recomposition. Ce territoire de 88 631 km2 et presque 10 000 000 d’habitants, placé sur les confins orientaux de l’Union européenne, connaît à la fois un processus d’intégration européenne et cherche sa place dans l’Europe du sud-est. L’espace balkanique est devenu, depuis la découverte d’importants gisements d’hydrocarbures en mer Caspienne en 1997, une plaque tournante des réseaux de gazoducs et d’oléoduc...

  17. FOSSIL FUEL BIODEGRADATION: LABORATORY STUDIES

    Science.gov (United States)

    Natural processes of biodegradation, that return carbon from its various organic forms to the inorganic state, are increasingly screened for bioremediation applications. ariety of microbial systems capable of degrading synthetic organic chemicals, from pesticides to polychlorinat...

  18. Anaerobic biodegradability of kitchen waste

    OpenAIRE

    Neves, L.; Oliveira, Rosário; M. Mota; Alves, M.M.

    2002-01-01

    Biodegradability of synthetic and real kitchen wastes was assessed in batch assays, under different solid contents between 1,8 and 24% and waste/inoculum ratios between 0,2 and 29 VSwaste/Vsseed sludge. Methanization rate and cumulative methane production from synthetic wastes simulated with different blends of protein, carbohydrates, fat and cellulose were compared. Although the excess of protein, carbohydrates and cellulose enhanced the biodegradability by 16 to 48%, the excess of fat re...

  19. Kinetic Modeling of Complex Catalytic Reactions Modélisation cinétique des réactions catalytiques complexes

    Directory of Open Access Journals (Sweden)

    Froment G. F.

    2006-11-01

    Full Text Available The paper deals with hydrocracking on metal-loaded zeolites. A fundamental approach is presented in which the detailed reaction network of the feed components of a complex feedstock is retained to a maximum extent. The kinetics are developed in terms of the elementary steps and single events involved in the reactions. Plausible assumptions and thermodynamic constraints limit the number of kinetic parameters. These do not depend on the chain length of the hydrocarbons and are not affected by the feed composition. Certainly, chemical analysis still imposes a certain degree of lumping of components and reaction networks, but not to the extent reflected by present day models. L'article traite de l'hydrocraquage sur des zéolites chargés en métaux. Dans l'approche fondamentale qui est présentée, le réseau de réaction des composants d'une charge complexe est retenu au maximum. La cinétique est établie en suivant pas à pas le déroulement et les étapes élémentaires des réactions. Des hypothèses plausibles et des contraintes thermodynamiques limitent le nombre de paramètres cinétiques. Ceux-ci ne dépendent pas de la longueur de la chaîne des hydrocarbures et ne sont pas affectés par la composition de la charge. L'analyse chimique impose bien sûr encore un certain agrégat des composants et des réseaux de réaction, mais moins que ne reflètent les modèles actuels.

  20. Assessing the toxicity and biodegradability of deep eutectic solvents.

    Science.gov (United States)

    Wen, Qing; Chen, Jing-Xin; Tang, Yu-Lin; Wang, Juan; Yang, Zhen

    2015-08-01

    Deep eutectic solvents (DESs) have emerged as a new type of promising ionic solvents with a broad range of potential applications. Although their ecotoxicological profile is still poorly known, DESs are generally regarded as "green" because they are composed of ammonium salts and H-bond donors (HBDs) which are considered to be eco-friendly. In this work, cholinium-based DESs comprised of choline chloride (ChCl) and choline acetate (ChAc) as the salt and urea (U), acetamide (A), glycerol (G) and ethylene glycol (EG) as the HBD were evaluated for their toxic effects on different living organisms such as Escherichia coli (a bacterium), Allium sativum (garlic, a plant) and hydra (an invertebrate), and their biodegradabilities were assessed by means of closed bottle tests. These DESs possessed an anti-bacterial property and exhibited inhibitory effects on the test organisms adopted, depending on the composition and concentration of the DES. The mechanism for the impact of DESs and their components on different living organisms can be associated to their interactions with the cellular membranes. Not all DESs can be considered readily biodegradable. By extending the limited knowledge about the toxicity and biodegradation of this particular solvent family, this investigation on DESs provides insight into our structure-based understanding of their ecotoxicological behavior. PMID:25800513

  1. Progress of biodegradable metals

    Directory of Open Access Journals (Sweden)

    Huafang Li

    2014-10-01

    Full Text Available Biodegradable metals (BMs are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompatibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  2. Biodegradation of polyethoxylated nonylphenols.

    Science.gov (United States)

    Ruiz, Yassellis; Medina, Luis; Borusiak, Margarita; Ramos, Nairalith; Pinto, Gilberto; Valbuena, Oscar

    2013-01-01

    Polyethoxylated nonylphenols, with different ethoxylation degrees (NPEO x ), are incorporated into many commercial and industrial products such as detergents, domestic disinfectants, emulsifiers, cosmetics, and pesticides. However, the toxic effects exerted by their degradation products, which are persistent in natural environments, have been demonstrated in several animal and invertebrate aquatic species. Therefore, it seems appropriate to look for indigenous bacteria capable of degrading native NPEO x and its derivatives. In this paper, the isolation of five bacterial strains, capable of using NPEO 15 , as unique carbon source, is described. The most efficient NPEO 15 degrader bacterial strains were identified as Pseudomonas fluorescens (strain Yas2) and Klebsiella pneumoniae (strain Yas1). Maximal growth rates were reached at pH 8, 27°C in a 5% NPEO 15 medium. The NPEO 15 degradation extension, followed by viscometry assays, reached 65% after 54.5 h and 134 h incubation times, while the COD values decreased by 95% and 85% after 24 h for the Yas1 and Yas2 systems, respectively. The BOD was reduced by 99% and 99.9% levels in 24 h and 48 h incubations. The viscosity data indicated that the NPEO 15 biodegradation by Yas2 follows first-order kinetics. Kinetic rate constant (k) and half life time (τ) for this biotransformation were estimated to be 0.0072 h(-1) and 96.3 h, respectively. PMID:23936727

  3. Progress of biodegradable metals

    Institute of Scientific and Technical Information of China (English)

    Huafang Li; Yufeng Zheng; Ling Qin

    2014-01-01

    Biodegradable metals (BMs) are metals and alloys expected to corrode gradually in vivo, with an appropriate host response elicited by released corrosion products, then dissolve completely upon fulfilling the mission to assist with tissue healing with no implant residues. In the present review article, three classes of BMs have been systematically reviewed, including Mg-based, Fe-based and Zn-based BMs. Among the three BM systems, Mg-based BMs, which now have several systems reported the successful of clinical trial results, are considered the vanguards and main force. Fe-based BMs, with pure iron and Fe–Mn based alloys as the most promising, are still on the animal test stage. Zn-based BMs, supposed to have the degradation rate between the fast Mg-based BMs and the slow Fe-based BMs, are a rising star with only several reports and need much further research. The future research and development direction for the BMs are proposed, based on the clinical requirements on controllable degradation rate, prolonged mechanical stability and excellent biocompat-ibility, by optimization of alloy composition design, regulation on microstructure and mechanical properties, and following surface modification.

  4. Fabrication Methods of Fullerenes. a Critical Review Méthodes de fabrication des fullerènes. Une étude critique

    Directory of Open Access Journals (Sweden)

    Emberson S. C.

    2006-11-01

    Full Text Available The industrial use of fullerenes will require a significant up-scaling of their production. The five actually known techniques are discussed : 1. The electric arc (Krätschmer-Huffman. 2. The vaporization of carbon by pulsed lasers. 3. The direct vaporization of carbon in focused sunlight. 4. The direct inductive heating of carbon. 5. Sooting hydrocarbon flames. The difficulty of up-scaling the electric arc set-up because of the photochemical destruction of fullerenes will be demonstrated. The use of sooting hydrocarbon flames for an industrial production of fullerenes is suggested. L'utilisation industrielle de fullerènes nécessitera une augmentation significative de leur production. Les cinq techniques actuellement connues sont discutées : 1. L'arc électrique (Krätschmer-Huffman. 2. L'évaporation de carbone par laser pulsé. 3. L'évaporation de carbone par lumière solaire focalisée. 4. L'évaporation thermique de carbone. 5. Une flamme d'hydrocarbures formant des suies. On met en évidence la difficulté d'une montée en échelle des installations à base d'arcs électriques à cause de la destruction photochimique des fullerènes. L'utilisation de flammes produisant des suies est proposée pour la production industrielle de fullerènes.

  5. Des guides et des cartes

    OpenAIRE

    Mathieu, Patricia; Maryvonne LE BERRE; Jean-Marc ROCHE

    1987-01-01

    Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  6. Des guides et des cartes

    Directory of Open Access Journals (Sweden)

    Patricia MATHIEU

    1987-12-01

    Full Text Available Consultés pour leurs références régionales ou locales, les guides touristiques donnent aussi une vision globale de la France qui est rarement perçue par l'utilisateur. Différents types de représentations cartographiques ont été choisis pour montrer, à partir d'informations simples, découpage en «régions» touristiques, étoilement des sites et des espaces touristiques, cette image de la France.

  7. Effects of the Biodegradation on Biodegradable Polymer Blends and Polypropylene

    Science.gov (United States)

    Pereira, R. C. T.; Franchetti, S. M. M.; Agnelli, J. A. M.; Mattoso, L. H. C.

    2008-08-01

    The large use of plastics in the world generates a large amount of waste which persists around 200 years in the environment. To minimize this effect is important to search some new polymer materials: the blends of biodegradable polymers with synthetic polymers. It is a large area that needs an intensive research to investigate the blends properties and its behavior face to the different treatments to aim at the biodegradation. The blends used in this work are: some biodegradable polymers such as: poly(hydroxybutyrate) (PHB) and poly(ɛ-polycaprolactone) (PCL) with a synthetic polymer, polypropylene (PP), in lower concentration. These blends were prepared using an internal mixer (Torque Rheometer), and pressed. These films were submitted to fungus biotreatment. The films analyses will be carried out by Fourier Transform Infrared (FTIR), UV-Vis absorption (UV-Vis), Scanning Electronic Microscopy (SEM), DSC and TGA.

  8. Aqueous Solubility of Hydrocarbon Mixtures Solubilité dans l'eau de mélanges d'hydrocarbures

    Directory of Open Access Journals (Sweden)

    De Hemptinne J. C.

    2006-12-01

    Full Text Available The solubility of hydrocarbon components in water is of great importance for the environmental sciences. Its prediction is usually based on using the pure component solubilities and the mole fraction of the components in the mixture. While the pure component solubilities are generally well known, few data exist on the solubility of mixtures. Using a simple relationship leads to an underestimation of the true solubility. This paper presents some new data on the aqueous solubility of binary hydrocarbon mixtures. Using a rigorous thermodynamic analysis, we explain the observed behavior, as well as other data from the literature, including the solubility of jet fuel mixtures in water. The activity coefficient models used for this purpose are NRTL, UNIQUAC and UNIFAC. Considering the small concentration in oil of some very soluble substances, the activity coefficient can become significant and thus explain the fact that solubilities of some component may be as much as twice as large as expected. La solubilité de composés hydrocarbonés dans l'eau est d'une importance cruciale pour les sciences environnementales. Sa prévision est généralement basée sur la solubilité des constituants purs et de leur fraction molaire en mélange. La solubilité des composés purs est généralement bien connue, mais peu de données ont été publiées concernant les mélanges. L'utilisation d'une relation simple conduit à une sous-estimation de la solubilité réelle. Cet article présente quelques données nouvelles de solubilités de mélanges hydrocarbonés simples. Une analyse thermodynamique rigoureuse permet de décrire la solubilité observée, aussi bien pour des mélanges modèles que pour des kérosènes. Les modèles de coefficient d'activité utilisés dans ce but sont NRTL, UNIQUAC et UNIFAC. Étant donné la faible concentration de certains constituants dans l'huile, leurs coefficients d'activité peut devenir important. Ceci explique une

  9. Adhesion of biocompatible and biodegradable micropatterned surfaces

    NARCIS (Netherlands)

    Kaiser, J.S.; Kamperman, M.M.G.; Souza, E.J.; Schick, B.; Arzt, E.

    2011-01-01

    We studied the effects of pillar dimensions and stiffness of biocompatible and biodegradable micropatterned surfaces on adhesion on different compliant substrates. The micropatterned adhesives were based on biocompatible polydimethylsiloxane (PDMS) and biodegradable poly(lactic-co-glycolic) acid (PL

  10. Poly (3-Hydroxyalkanoates: Biodegradable Plastics

    Directory of Open Access Journals (Sweden)

    Surbhi Jain

    2013-03-01

    Full Text Available During the 1920’s, a polyester called poly (3-hydroxybutyrate was discovered in bacterial cells. This compound, otherwise known as PHB, is part of a polyester family called polyhydroxyalkanoates (PHAs. Polyhydroxyalkanoates are used as an energy and carbon sto rage compound within certain bacterial cells. Polyhydroxyalkanoates (PHAs are thermoplastic, biodegradable polyesters synthesized by some bacteria from renewable carbon sources. However, their application is limited by high production cost. Polyhydroxyalkanoates (PHAs have attracted research and commercial interests worldwide because they can be used as biodegradable thermoplastics and also because they can be produced from renewable resources. This review will present an overview on synthesis and degradation of polyhydroxyalkanoates (PHAs, development as biodegradable plastics and its potential production from renewable resources such as palm oil products.

  11. Des tuiles, des toits et des couleurs

    OpenAIRE

    Bonnot, Thierry

    2007-01-01

    La Bourgogne est une des régions françaises dont l’image de marque est le plus imprégnée par la notion de tradition. Elle est présentée comme un terroir où il fait bon vivre, où la gastronomie demeure à travers les siècles une valeur de base, où les paysages sont majestueux et où la gloire passée est sans cesse rappelée par de somptueux monuments. Parmi quelques emblèmes, l’hôtel-Dieu de Beaune et ses toitures de tuiles colorées sont très souvent mobilisés pour représenter ces valeurs « tradi...

  12. Production polyphasique. Modélisation des écoulements à bouchons Multiphase Production Slug-Flow Modeling

    Directory of Open Access Journals (Sweden)

    Drouffe J. M.

    2006-11-01

    Full Text Available L'exploitation des hydrocarbures en mer reste une activité coûteuse et qui peut, même, se révéler, éventuellement dangereuse. Les concepts de production polyphasique tels que Poséidon permettent à la fois : - une réduction importante des coûts de production; - la suppression des risques humains liés à la présence permanente en mer d'équipes importantes. Les programmes de simulation des écoulements diphasiques actuellement disponibles pour la mise en oeuvre de ces concepts, sont tous basés sur une approche déterministeclassique. Cet article présente une nouvelle approche statistiquenon conventionnelle qui devrait nous permettre de mieux préciser les caractéristiques des écoulements à bouchons et donc de pouvoir mieux dimensionner et exploiter nos futures installations de production et transport polyphasique longue distance. Offshore hydrocarbon production remains a costly venture, and even one that might possibly be dangerous. Multiphase production concepts such as Poseidon make for both a considerable reduction in production costs and the elimination of human risks linked to the constant offshore presence of large crews. The two-phase flow simulation programs now available for implementing such concepts are all based on a standard deterministicapproach. This article describes a new and unconventional statisticalapproach that we feel more accurately describes the characteristics of slug flows and hence is more effecting for the sizing and operating of future production and long-distance pipelining installations.

  13. Etude stratigraphique, pétrographique et diagénétique des grès d'âge Crétacé-Paléogène de la région ouest du bassin du lac Turkana, Kenya. Conséquences sur leurs caractéristiques réservoir et l'évaluation du potentiel pétrolier du nord-ouest du Kenya.

    OpenAIRE

    Thuo, Peter

    2009-01-01

    Les segments centre et nord du Rift du Kenya sont aujourd'hui considérés comme parmi les régions du Système de Rift Est-africain les plus prometteuses pour l'exploration pétrolière. Au cours des années 70, de nombreuses compagnies pétrolières se sont intéressées à la région nord-est du Kenya, correspondant au système de rift d'Anza (âge Crétacé-Miocène), sans réaliser de découverte pétrolière. C'est à la suite de la mise en évidence au cours des années 80 d'importantes réserves en hydrocarbur...

  14. Biodegradable congress 2012; Bioschmierstoff-Kongress 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-11-01

    Within the Guelzower expert discussions at 5th and 6th June, 2012 in Oberhausen (Federal Republic of Germany) the following lectures were held: (1) Promotion of biodegradable lubricants by means of research and development as well as public relations (Steffen Daebeler); (2) Biodegradable lubricants - An overview of the advantages and disadvantages of the engaged product groups (Hubertus Murrenhoff); (3) Standardization of biodegradable lubricants - CEN/DIN standard committees - state of the art (Rolf Luther); (4) Market research for the utilization of biodegradable lubricants and means of proof of sustainability (Norbert Schmitz); (5) Fields of application for high performance lubricants and requirements upon the products (Gunther Kraft); (6) Investigations of biodegradable lubricants in rolling bearings and gears (Christoph Hentschke); (7) Biodegradable lubricants in central lubrication systems Development of gears and bearings of offshore wind power installations (Reiner Wagner); (8) Investigations towards environmental compatibility of biodegradable lubricants used in offshore wind power installations (Tolf Schneider); (9) Development of glycerine based lubricants for the industrial metalworking (Harald Draeger); (10) Investigations and utilization of biodegradable oils as electroinsulation oils in transformers (Stefan Tenbohlen); (11) Operational behaviour of lubricant oils in vegetable oil operation and Biodiesel operation (Horst Hamdorf); (12) Lubrication effect of lubricating oil of the third generation (Stefan Heitzig); (13) Actual market development from the view of a producer of biodegradable lubricants (Frank Lewen); (14) Utilization of biodegradable lubricants in forestry harvesters (Guenther Weise); (15) New biodegradable lubricants based on high oleic sunflower oil (Otto Botz); (16) Integrated fluid concept - optimized technology and service package for users of biodegradable lubricants (Juergen Baer); (17) Utilization of a bio oil sensor to control

  15. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the...

  16. Biodegradable Pectin/clay Aerogels

    Science.gov (United States)

    Biodegradable, foamlike materials based on renewable pectin and sodium montmorillonite clay were fabricated through a simple, environmentally friendly freeze-drying process. Addition of multivalent cations (Ca2+ and Al3+) resulted in apparent crosslinking of the polymer, and enhancement of aerogel p...

  17. Studies in Petroleum Composition the Distribution of Nitrogen Species, Metals and Coke Precursors During High Vacuum Distillation of Petroleum Étude de composition du pétrole Répartition des espèces azotées, des métaux et des précurseurs du coke pendant la distillation sous vide poussé du pétrole

    Directory of Open Access Journals (Sweden)

    Long R. B.

    2006-11-01

    tudie cette question et tente de décrire l'influence d'une distillation approfondieà +1289 °F (environ 698 °C sur la composition en produits volatils/non volatils d'un résidu obtenu à + 950 °F (510 °C. A +1289 °F, la distillation concentre dans la fraction obtenue la majorité de l'azote, du nickel, du vanadium et des produits de tête. Cependant, étant donné le niveau élevé de son point de coupe, cette procédure implique virtuellement que certaines molécules contenant des hétéroatomes seront volatiles au point de coupe. Des quantités significatives de ces produits se trouvent dans la fraction 950-1289 °F. Parmi ceux d'entre eux qui contiennent de l'azote, on pourra trouver des benzophénanthrolines et des benzocarbazoles alkylés dont les points d'ébullition se situent dans le domaine 950-1289 °F. Il n'est pas non plus surprenant de trouver dans cette fraction des métaux volatils, puisque les organométalliques se vaporisent vers 1100 °F (environ 593 °C. Les matériaux du domaine A-1289 °F ont donné des rendements élevés en pentane- et heptane- -asphaltènes. Le bilan des poids des asphaltènes sur la base A-950 °F fait apparaître des quantités excessives d'asphaltènes dans le domaine A-1289 °F dépassant la marge d'erreurs permise dans la technique de désalphatage. On a également noté des déséquilibresen asphaltène comparables, lorsque des matières lourdes sont fractionnées par un désalphatage séquentiel utilisant des hydrocarbures différents à chaque étape (13. On peut penser que la technique d'adsorption, comme le désalphatage séquentiel, rompt les forces intermoléculaires qui, autrement, pourraient rendre les constituants de la charge solubles dans les hydrocarbones, du fait de la nature non polaire des participants. Dans le cas présent, on peut penser que les forces intermoléculaires du A-1289 °F sont plus difficiles à rompre par les n-paraffines (ou par le toluène du fait de l'absence relative (par rapport à A-950

  18. Biobased and biodegradable polymer nanocomposites

    Science.gov (United States)

    Qiu, Kaiyan

    In this dissertation, various noncrosslinked and crosslinked biobased and biodegradable polymer nanocomposites were fabricated and characterized. The properties of these polymer nanocomposites, and their relating mechanisms and corresponding applications were studied and discussed in depth. Chapter 1 introduces the research background and objectives of the current research. Chapter 2 presents the development of a novel low cost carbon source for bacterial cellulose (BC) production and fabrication and characterization of biobased polymer nanocomposites using produced BC and soy protein based resins. The carbon source, soy flour extract (SFE), was obtained from defatted soy flour (SF) and BC yield achieved using SFE medium was high. The results of this study showed that SFE consists of five sugars and Acetobacter xylinum metabolized sugars in a specific order. Chapter 3 discusses the fabrication and characterization of biodegradable polymer nanocomposites using BC and polyvinyl alcohol (PVA). These polymer nanocomposites had excellent tensile and thermal properties. Crosslinking of PVA using glutaraldehyde (GA) not only increased the mechanical and thermal properties but the water-resistance. Chapter 4 describes the development and characterization of microfibrillated cellulose (MFC) based biodegradable polymer nanocomposites by blending MFC suspension with PVA. Chemical crosslinking of the polymer nanocomposites was carried out using glyoxal to increase the mechanical and thermal properties as well as to make the PVA partially water-insoluble. Chapter 5 reports the development and characterization of halloysite nanotube (HNT) reinforced biodegradable polymer nanocomposites utilizing HNT dispersion and PVA. Several separation techniques were used to obtain individualized HNT dispersion. The results indicated uniform dispersion of HNTs in both PVA and malonic acid (MA) crosslinked PVA resulted in excellent mechanical and thermal properties of the materials, especially

  19. Géochimie des résines et asphaltènes Geochernistry of Resins and Asphaltenes

    Directory of Open Access Journals (Sweden)

    Tissot B.

    2006-11-01

    Full Text Available Les produits lourds des huiles brutes (résines et asphaltènes jouent un rôle important dans la genèse et l'accumulation du pétrole, ainsi que dans la mise en production par des méthodes conventionnelles ou par récupération assistée. Les asphaltènes et résines sont considérés ici comme des fragments de kérogène, avec une structure d'ensemble comparable : ils peuvent constituer des intermédiaires dans la genèse de l'huile brute par dégradation thermique du kérogène. De plus, la pyrolyse des asphaltènes séparés à partir d'un pétrole biodégradé peut produire de nouveaux hydrocarbures saturés qui reproduisent la fraction saturée primitive, détruite par la dégradation ; on peut ainsi disposer d'un nouvel outil pour corréler ce type d'huiles brutes. Les produits lourds semblent défavorisés par rapport aux hydrocarbures, dans la migration de la roche-mère vers le réservoir, où les résines et asphaltènes sont proportionnellement moins abondants. La structure physique des asphaltènes et résines dans les pétroles, et en particulier l'existence d'une macrostructure du type micelles ou agrégats, est probablement responsable de la viscosité élevée des huiles lourdes. Une meilleure connaissance de cette macrostructure pourrait suggérer de nouvelles méthodes pour diminuer la viscosité et améliorer la récupération des huiles lourdes. The heavy constituents of crude oil (resins and asphaltenes play an important role in generation and accumulation of petroleum, and also in production by conventional and enhanced oil recovery processes. Asphaltenes and resins are considered here as small fragments of kerogen, with a comparable overall structure: they may act as intermediate compounds in oil generation by thermal breakdown of kerogen. Furthermore, pyrolysis of asphaltenes separated from a degraded crude oil is able to generate a new saturated hydrocarbon fraction which duplicates the original one, now degraded

  20. Development and Testing of Xanthan Products for Eor-Applications in the North Sea Développement et essais des produits à base de xanthane pour les applications de RAH en mer du Nord

    Directory of Open Access Journals (Sweden)

    Foss P.

    2006-11-01

    Full Text Available A program for development and evaluation of xanthan for use in enhanced oil recovery projects in the North Sea has been performed. Xanthan was produced using different fermentation conditions. Rheological measurements and filterability tests have been done. Xanthan products, which readily dissolve in sea water and give high viscosity and low aggregation have been produced. The fermentation process used for this type of product was scaled up from 10 litres to 20,000 litres production volume without significant changes in polymer solution properties. Un programme de développement et d'évaluation du xanthane pour utilisation dans les projets de récupération assistée des hydrocarbures en mer du Nord a été réalisé. Le xanthane est obtenu par différents procédés de fermentation. On a effectué des mesures rhéologiques et des essais de filtrabilité. Les produits à base de xanthane se dissolvent facilement dans l'eau de mer, ils donnent une forte viscosité et une faible agrégation. Avec le procédé de fermentation utilisé pour ce type de produit, on a pu faire passer la production de 10 litres à 20000 litres sans modification notable des propriétés de la solution de polymère.

  1. BIODEGRADABLE COATING FROM AGATHIS ALBA

    Directory of Open Access Journals (Sweden)

    NORYAWATI MULYONO

    2012-11-01

    Full Text Available The adhesive property of copal makes it as a potential coating onto aluminum foil to replace polyethylene. This research aimed to develop copal-based coating. The coating was prepared by extracting the copal in ethyl acetate and dipping the aluminium foil in ethyl acetate soluble extract of copal. The characterization of coating included its thickness, weight, thermal and chemical resistance, and biodegradation. The results showed that the coating thickness and weight increased as the copal concentration and dipping frequency increased. Thermal resistance test showed that the coating melted after being heated at 110°C for 30 min. Copal-based coating wasresistant to acidic solution (pH 4.0, water, and coconut oil, but was deteriorated in detergent 1% (w/v and basic solution (pH 10.0. Biodegradability test using Pseudomonas aeruginosa showed weight reduction of 76.82% in 30 days.

  2. Biodegradation of Polycyclic Aromatic Hydrocarbons

    OpenAIRE

    DEMİR, İsmail; DEMİRBAĞ, Zihni

    1999-01-01

    Polycylic aromatic hydrocarbons (PAHs), such as petroleum and petroleum derivatives, are widespread organic pollutants entering the environment, chiefly, through oil spills and incomplete combustion of fossil fuels. Since most PAHs are persist in the environment for a long period of time and bioaccumulate, they cause environmental pollution and effect biological equilibrium dramatically. Biodegradation of some PAHs by microorganisms has been biochemically and genetically investigated. Ge...

  3. Biodegradable lubricants for road vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Schramm, J. [Denmark Technical Univ., Lyngby (Denmark). Dept. of Mechanical Engineering

    2004-07-01

    This presentation outlined the characteristics of biolubricants and their use in vehicles. Experiments with compression ignition (CI) and spark ignition (SI) engines were also presented. Biolubes can be used in 4-stroke and 2-stroke engines, bearing compressors and hydraulic equipment. Studies have shown that biolubes do not cause unusual engine wear. They are produced from biomass, with the base material being vegetable oils and synthetic esters. Conventional lubricants are produced from fossil fuels, with the base material being mineral oils, polyglycol or synthetic ester. This presentation rated the characteristics of various lubricants in terms of viscosity temperature behaviour, low temperature behaviour, liquid range, oxidation stability, thermal stability, volatility, fire resistance, hydrolytic stability, corrosion protection, seal material compatibility, paints compatibility, miscibility with mineral oil, solubility of additives, lubricating properties, toxicity, and biodegradability. The environmental impacts of biolubes regarding emissions of carbon dioxide, nitrous oxide and particulate matter were discussed along with the impact of combining biolubes with alternative fuels. The future beneficial applications include outboard engines, off road vehicle engines and road vehicle engines. Currently, vegetable oil based biolubricants are 2 to 3 times more expensive than mineral based oils, and synthetic lubricants are even more expensive. It was suggested that future studies should examine the biodegradability of used lubricants, the performance of biodegradable lubricants, alternative fuels and fuel economy. tabs., figs.

  4. Engineering Flame Retardant Biodegradable Nanocomposites

    Science.gov (United States)

    He, Shan; Yang, Kai; Guo, Yichen; Zhang, Linxi; Pack, Seongchan; Davis, Rachel; Lewin, Menahem; Ade, Harald; Korach, Chad; Kashiwagi, Takashi; Rafailovich, Miriam

    2013-03-01

    Cellulose-based PLA/PBAT polymer blends can potentially be a promising class of biodegradable nanocomposites. Adding cellulose fiber reinforcement can improve mechanical properties of biodegradable plastics, but homogeneously dispersing hydrophilic cellulose in the hydrophobic polymer matrix poses a significant challenge. We here show that resorcinol diphenyl phosphates (RDP) can be used to modify the surface energy, not only reducing phase separation between two polymer kinds but also allowing the cellulose particles and the Halloysite clay to be easily dispersed within polymer matrices to achieve synergy effect using melt blending. Here in this study we describe the use of cellulose fiber and Halloysite clay, coated with RDP surfactant, in producing the flame retardant polymer blends of PBAT(Ecoflex) and PLA which can pass the stringent UL-94 V0 test. We also utilized FTIR, SEM and AFM nanoindentation to elucidate the role RDP plays in improving the compatibility of biodegradable polymers, and to determine structure property of chars that resulted in composites that could have optimized mechanical and thermal properties. Supported by Garcia Polymer Center and NSF Foundation.

  5. Radiation effects on biodegradable polyesters

    International Nuclear Information System (INIS)

    Poly(3-hydroxybutyrate) [P(3HB)] and its copolymer poly(3-hydroxybutyrate-co-3hydroxyvalerate) [P(3HB-co-3HV)] are microbial biodegradable polyesters produced by many types of bacteria. Poly(butylene succinate) (PBS) and poly(E-caprolactone) (PCL) are also biodegradable synthetic polyesters which have been commercialized. These thermoplastics are expected for wide usage in environmental protection and blocompatible applications. Radiation grafting of hydrophilic monomers onto many polymers, e.g., polyethylene and polypropylene has been studied mainly for biomedical applications. In the present study, radiation-induced graft polymerization of vinyl monomers onto PHB and P(3HB-co-3HV) was carried out and improvement of their properties was studied. Changes in the properties and biodegradability were compared with the degree of grafting. Radiation-induced crosslinking of PBS and PCL which relatively show thermal and irradiation stability was also carried out to improve their thermal stability or processability. Irradiation to PBS and PCL mainly resulted in crosslinking and characterization of these crosslinked polyesters was investigated

  6. Biodegradation of high molecular weight polylactic acid

    OpenAIRE

    Stloukal, Petr; Koutný, Marek; Sedlařík, Vladimír; Kucharczyk, Pavel

    2012-01-01

    Polylactid acid seems to be an appropriate replacement of conventional non-biodegradable synthetic polymer primarily due to comparable mechanical, thermal and processing properties in its high molecular weight form. Biodegradation of high molecular PLA was studied in compost for various forms differing in their specific surface area. The material proved its good biodegradability under composting conditions and all investigated forms showed to be acceptable for industrial composting. Despite e...

  7. Biodegradable materials as foundry moulding sands binders

    OpenAIRE

    K. Major-Gabryś

    2015-01-01

    The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved abilit...

  8. Biodegradable materials as foundry moulding sands binders

    Directory of Open Access Journals (Sweden)

    K. Major - Gabryś

    2015-07-01

    Full Text Available The aim of this article is to show the possibility of using biodegradable materials as part of the composition of foundry moulding and core sand binders. Research shows that moulding sands with biodegradable materials selected as binders are not only less toxic but are also better suited to mechanical reclamation than moulding sands with phenol-furfuryl resin. The use of biodegradable materials as additives to typical synthetic resins can result in their decreased toxicity and improved ability to reclamation as well as in accelerated biodegradation of binding material leftovers of mechanical reclamation.

  9. Séparations par changement de phase. Etude et représentation des équilibres liquide-vapeur Separation by Phase Hange. Study and Computing Liquid-Vapor Equilibria

    Directory of Open Access Journals (Sweden)

    Asselineau L.

    2006-11-01

    Full Text Available Pour concevoir et optimiser les principales opérations de séparation (particulièrement les distillations avec ou sans solvant et l'extraction liquide-liquide on doit disposer de méthodes de corrélation ou, mieux, de prédiction des équilibres entre phases. A basse pression, et pour les mélanges d'hydrocarbures, les résultats présentés permettent la prévision des coefficients d'équilibre, même pour les séparations les plus délicates. En présence de constituants polaires, les données expérimentales d'équilibre liquide-liquide et liquide-vapeur de mélanges binaires et ternaires peuvent être simultanément corrélées dans le but de simuler et d'optimiser les distillations azéotropiques ou extractives. Sous haute pression, et particulièrement aux abords immédiats du point critique, le choix d'une équation d'état conduit à un traitement unitaire des phases en présence et permet, en particulier, la prédiction du lieu des points critiques des mélanges d'hydrocarbures et la corrélation de ce lieu en présence de solvants polaires. To determine and optimize the main separation operations (in particular distillations with or without a solvent, and liquid-liquid extraction correlation methods must be available or, better yet, methods of predicting phase equilibria. At low pressure and for hydrocarbon mixtures, the results described make the prediction of equilibrium coefficients possible, even for the most delicate separation. In the presence of polar constituents, the experimental data for the liquid-liquid and liquid-vapor equilibrium of binary and ternary mixtures can be simultaneously correlaten so as to simulate and optimize azeotropic or extractive distillations. Under high pressure and especially in the immediate vicinityof the critical point, the choice of an equation of state leads ta a unit treatment of the phases present and, in particular, makes it possible to predict the location of critical points in hydrocarbon

  10. Phase behaviour in water/hydrocarbon mixtures involved in gas production systems; etude des equilibres des systemes: eau-hydrocarbures-gaz acides dans le cadre de la production de gaz

    Energy Technology Data Exchange (ETDEWEB)

    Chapoy, A.

    2004-11-15

    Inside wells, natural gases frequently coexist with water. The gases are in equilibrium with the sub-adjacent aquifer. Many problems are associated with the presence of water during the production, transport and processing of natural gases. Accurate knowledge of the thermodynamic properties of the water/hydrocarbon and water-inhibitor/hydrocarbon equilibria near the hydrate forming conditions, at sub-sea pipeline conditions and during the transport is crucial for the petroleum industry. An apparatus based on a static/analytic method combined with a dilutor apparatus to calibrate on the gas chromatograph (GC) detectors with water was used to measure the water content of binary systems (i.e.: water - methane, ethane - water, nitrogen - water...) as well of a synthetic hydrocarbon gas mixture (i.e.: 94% methane, 4% ethane and 2% n-butane) with and without inhibitor. This same apparatus was also used generate data of methane, ethane, propane, n-butane and nitrogen solubility in water and also the solubilities of a synthetic mixture in water. In-house software has been developed in order to fit and model the experimental data. (author)

  11. A new group-contribution method for the estimation of physical properties of hydrocarbons; Nouvelle methode de contribution de groupes pour l'estimation des proprietes physiques des hydrocarbures

    Energy Technology Data Exchange (ETDEWEB)

    Skander, N. [Centre de Recherche et Developpement de Sonatrach, Boumerdes (Algeria); Chitour, C.E. [Ecole Nationale Polytechnique, Lab. de Valorisation des Energies Fossiles, Dept. de Genie Chimique, Alger (Algeria)

    2002-08-01

    In the present work, we propose a new group-contribution method to estimate the boiling point, freezing point and the liquid density at 20 deg C of hydrocarbons. The method was tested with satisfactory accuracy, and when compared with other group-contribution methods, it reveals better results in terms of average standard deviations. (authors)

  12. Prediction of surface tensions, acentric factors and refractive index parameters of pure hydrocarbon's; Prediction des tensions superficielles, facteurs acentriques et indices de correlation des hydrocarbures purs

    Energy Technology Data Exchange (ETDEWEB)

    Adamou, A.; Chitour, C.E. [Ecole Nationale Polytechnique, Lab. de Valorisation des Energies Fossiles, Dept. de Genie Chimique, Alger (Algeria); Skander, N. [Centre de Recherche et Developpement de Sonatrach, Boumerdes (Algeria)

    2004-07-01

    A new group contribution method for the estimation of surface tensions, acentric factors and refractive index parameters of pure hydrocarbons was established. The average absolute deviations (AAD) obtained between tabulated and calculated values are respectively 2.5%, 4.1% and 1.5% for surface tension, acentric factor and refractive index parameter. (authors)

  13. Biodegradable Polymers Influence the Effect of Atorvastatin on Human Coronary Artery Cells

    Directory of Open Access Journals (Sweden)

    Anne Strohbach

    2016-01-01

    Full Text Available Drug-eluting stents (DES have reduced in-stent-restenosis drastically. Yet, the stent surface material directly interacts with cascades of biological processes leading to an activation of cellular defense mechanisms. To prevent adverse clinical implications, to date almost every patient with a coronary artery disease is treated with statins. Besides their clinical benefit, statins exert a number of pleiotropic effects on endothelial cells (ECs. Since maintenance of EC function and reduction of uncontrolled smooth muscle cell (SMC proliferation represents a challenge for new generation DES, we investigated the effect of atorvastatin (ATOR on human coronary artery cells grown on biodegradable polymers. Our results show a cell type-dependent effect of ATOR on ECs and SMCs. We observed polymer-dependent changes in IC50 values and an altered ATOR-uptake leading to an attenuation of statin-mediated effects on SMC growth. We conclude that the selected biodegradable polymers negatively influence the anti-proliferative effect of ATOR on SMCs. Hence, the process of developing new polymers for DES coating should involve the characterization of material-related changes in mechanisms of drug actions.

  14. Biodegradable Polymers Influence the Effect of Atorvastatin on Human Coronary Artery Cells.

    Science.gov (United States)

    Strohbach, Anne; Begunk, Robert; Petersen, Svea; Felix, Stephan B; Sternberg, Katrin; Busch, Raila

    2016-01-01

    Drug-eluting stents (DES) have reduced in-stent-restenosis drastically. Yet, the stent surface material directly interacts with cascades of biological processes leading to an activation of cellular defense mechanisms. To prevent adverse clinical implications, to date almost every patient with a coronary artery disease is treated with statins. Besides their clinical benefit, statins exert a number of pleiotropic effects on endothelial cells (ECs). Since maintenance of EC function and reduction of uncontrolled smooth muscle cell (SMC) proliferation represents a challenge for new generation DES, we investigated the effect of atorvastatin (ATOR) on human coronary artery cells grown on biodegradable polymers. Our results show a cell type-dependent effect of ATOR on ECs and SMCs. We observed polymer-dependent changes in IC50 values and an altered ATOR-uptake leading to an attenuation of statin-mediated effects on SMC growth. We conclude that the selected biodegradable polymers negatively influence the anti-proliferative effect of ATOR on SMCs. Hence, the process of developing new polymers for DES coating should involve the characterization of material-related changes in mechanisms of drug actions. PMID:26805825

  15. Evaluation quantitative des produits formés lors de l'évolution géochimique de la matière organique Quantitative Evaluation of Products Formed During the Geochemical Evolution of Organic Matter

    Directory of Open Access Journals (Sweden)

    Pelet R.

    2006-11-01

    Full Text Available L'évaluation quantitative des produits mobiles formés lors de l'évolution géochimique de la matière organique est nécessaire parce qu'on ne peut jamais retrouver ces produits en place dans. la roche où ils ont pris naissance. Ils ont, en effet, pu migrer durant l'histoire géologique, et de toute manière une fraction, importante et non connue, se perd lors de la prise des échantillons puis de leur conservation avant analyse. La connaissance de l'analyse d'un état E et d'un état plus évolué E' ne suffit pas pour reconstituer les quantités de produits formés. La pyrolyse type Rock-Eval sur kérogènes, avec détermination du carbone résiduel, permet par contre, à partir d'une hypothèse raisonnable, de calculer les hydrocarbures produits. L'analyse élémentaire permet d'y ajouter CO2, H2O, H2S et N2 (considérés comme seuls produits à côté des hydrocarbures. Une analyse chromatographique sommaire supplémentaire permet d'estimer la composition globale des hydrocarbures. Dans le cas des roches, on propose des techniques de correction de l'effet de matrice pratiquement utilisables et qui permettent de retrouver les résultats précédents, au prix d'une incertitude accrue. The mobile products formed during the geochemical evolution of organic matter must be quantitatively evaluated because these products can never be found in place in the rock where they were formed. Indeed, they may have migrated during geological history, and in any case a large and unknown fraction gets lost when samples are taken and then stored before being analysed. Knowing the elemental analysis of a state E and of a more evolved state E' does not suffice for recreating the amounts of products formed. On the other hand Rock-Eval type pyrolysis of kerogens, including the determination of the residual carbon, can be used to compute the hydrocarbons produced, on the basis of a reasonable hypothesis. Elemental analysis then enables the evaluation of CO2, H2O

  16. Biodegradation kinetics at low concentrations (

    DEFF Research Database (Denmark)

    Toräng, Lars; Albrechtsen, Hans-Jørgen; Nyholm, Niels

    2000-01-01

    Aerobic biodegradation of 2,4-dichlorophenoxyacetic acid (2,4-D) was studied in groundwater added sediment fines. At concentrations at or below 1 mu g/L of 2,4-D degradation kinetic was of true first order without significant growth of specific degraders and with half-life for mineralization in the...... order of 200 days. Higher concentrations of 2,4-D resulted in a grossly overestimate of the actual degradation rate for concentrations characteristic for Danish found in groundwater....

  17. Strukturmerkmale des chinesischen Kapitalismus

    OpenAIRE

    Brink, Tobias ten

    2010-01-01

    Für ein Verständnis der chinesischen Wirtschaft ist es hilfreich, das theoretische Instrumentarium der Kapitalismusforschung nutzbar zu machen. Es ermöglicht eine fundierte Charakterisierung des chinesischen Systems als einer eigentümlichen Spielart des Kapitalismus – eines marktliberalen, wettbewerbsgetriebenen Staatskapitalismus. Zu den Eigentümlichkeiten des chinesischen Kapitalismus gehören ein dynamischer Staatsdirigismus, eine besondere Form des Wettbewerbs und der privat-öffentlichen U...

  18. Etude par imagerie radar des pollutions pétrolières

    Directory of Open Access Journals (Sweden)

    G. Rees

    2004-06-01

    Full Text Available En Russie, chaque année, les déversements de pétrole représentent un cinquième de la production totale. Les plus importants se produisent dans le domaine périglaciaire où le milieu naturel est d’une extrême fragilité. Les pipelines sont soumis à de rudes conditions notamment à la corrosion et aux processus cryogéniques. Le risque de rupture augmente en conséquence. La surveillance des déversements d’hydrocarbures, contrainte par l’immensité et la fréquente inaccessibilité du réseau de pipelines, peut être réalisée par le recours à la télédétection. L’objectif de ce travail est de fournir, à travers l’exemple de la catastrophe d’Usinsk (Rép. de Komi survenue en 1994, des outils d’analyse des images radar. Outre leur capacité à s’affranchir du couvert nuageux, les capteurs radar apportent des informations complémentaires à celles fournies par des capteurs optiques. L’exploitation thématique de ces images est rendue difficile par un certain nombre de facteurs perturbateurs tels que les caractéristiques propres du capteur, la direction de visée, la topographie et le phénomène de chatoiement (speckle. Le travail présenté montre le rôle prépondérant joué par ces corrections qui permettent de disposer de données quantitatives comparables d’une date à une autre. La méthode mise au point ici pour le suivi temporel de l’épanchement de pétrole d’Usinsk à partir de trois images radar, est discutée notamment dans ses limites et son aspect opérationnel possible.

  19. Civili, langue des Baloango

    DEFF Research Database (Denmark)

    Mavoungou, Paul Achille; Ndinga-Koumba-Binza, Hugues Steve

    , Congo, Angola, etc.) issus de la décolonisation. Il présente de façon succincte quelques phénomènes historiques, phonologiques, morphosyntaxiques, homonymiques et analogiques de la langue. Des faits sémantiques des emprunts linguistiques y sont également décrits dans le cadre des changements...

  20. Remittances | Transferts des migrants

    OpenAIRE

    2012-01-01

    Major Recipients of Remittances (in Million USD, 2008) Principaux pays bénéficiaires des transferts des migrants (en millions USD, 2008) ­ Migrants’ Remittances per Capita (in USD, 2008) Transferts des migrants par habitant (en USD, 2008) Source: World Bank, migration and remittances data.

  1. Biodegradation and toxicological evaluation of lubricant oils

    Directory of Open Access Journals (Sweden)

    Ivo Shodji Tamada

    2012-12-01

    Full Text Available The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei, arugula seeds (Eruca sativa and lettuce seeds (Lactuca sativa, with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days of biodegradation. The used lubricant oil was proved very toxic in all the tests and even after biodegradation its toxicity was high. The mineral and synthetic oils were biodegraded efficiently in the soil although their toxicity did not disappear completely after 180 days.

  2. L’impact des biocarburants sur l’effet de serre

    Directory of Open Access Journals (Sweden)

    Poitrat Etienne

    2002-09-01

    Full Text Available Selon les statistiques de l’Observatoire de l’Énergie [1], la France a consommé 267 Mtep (tonnes équivalent pétrole d’énergie primaire en 2001, ou 269 Mtep avec correction climatique. Cette consommation comprend 145,6 Mtep sous forme d’énergie fossile (tableau 1. Les émissions corrigées du seul CO2 correspondant à l’énergie primaire consommée ont été entre août 2001 et juillet 2002, de 109 Mt de carbone par an [2]. Les énergies renouvelables (EnR totales utilisées en France sont d’environ 28 Mtep/an, dont 16,1 tep sont produits par les grands barrages hydro-électriques. Les autres EnR sont les bioénergies (11,9 Mtep/an et les énergies restantes, sont la géothermie, le solaire, l’éolien et la petite hydraulique [3]. En Europe, la France occupe la 5e place avec 11,5 % d’énergie renouvelable consommée après la Suède (26,7 %, l’Autriche (23,3 %, la Finlande (20,9 % et le Portugal (16,9 % [4]. D’autre part, la réserve mondiale prouvée des énergies fossiles représente au rythme actuel de consommation, qui est de 77 % de l’énergie totale consommée (tableau 2, environ 45 ans pour le pétrole, 60 ans pour le gaz et 220 à 250 ans pour le charbon. Afin de réduire les émissions de carbone fossile issues de la combustion des 77 % des énergies fossiles utilisées, il est nécessaire de réduire les consommations d’énergie par des économies et l’amélioration des rendements, de développer les énergies renouvelables et les technologies de séquestration du carbone. En France, les transports dépendent à plus de 95 % des hydrocarbures, non renouvelables, dont l’utilisation a une part déterminante (24 % dans l’émission des gaz à effet de serre. Le transport routier représente 81 % de la consommation énergétique du secteur. L’effet de serre se manifeste par un réchauffement de la température de l’air (+ 0,5 °C/100 ans et des océans (+ 0,3 °C/30 ans, avec une augmentation de la

  3. Liste des contributeurs

    OpenAIRE

    2014-01-01

    Abouhani Abdelghani, Inau, Rabat. Blili Leïla, Université de La Manouba, Faculté des lettres, des arts et des humanités, La Manouba. Boubrik Rahal, Ihcc, Aix-en-Provence. Boujarra Hussein, Université de Tunis, Faculté des sciences humaines et sociales, Tunis/Diraset. Études maghrébines. Cattedra Raffaele, Université de Montpellier III. Catusse Myriam, Cnrs-Iremam, Aix-en-Provence. Cheraï Ahmed, École nationale d’administration, Rabat. Ettayeb Mahmoud, Université de Tunis, Faculté des sciences...

  4. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Lihui [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Zhang, Yongming, E-mail: zhym@shnu.edu.cn [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Bai, Qi; Yan, Ning; Xu, Hua [Department of Environmental Science and Engineering, College of Life and Environmental Science, Shanghai Normal University, Shanghai 200234 (China); Rittmann, Bruce E. [Swette Center for Environmental Biotechnology, Biodesign Institute, Arizona State University, Tempe, AZ 85287-5701 (United States)

    2015-04-28

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA.

  5. Intimately coupling of photolysis accelerates nitrobenzene biodegradation, but sequential coupling slows biodegradation

    International Nuclear Information System (INIS)

    Highlights: • Intimately coupled UV photolysis accelerated nitrobenzene biodegradation. • NB biodegradation was slowed by accumulation of nitrophenol. • Oxalic acid was a key product of UV photolysis. • Oxalic acid accelerated biodegradation of nitrobenzene and nitrophenol by a co-substrate effect. • Intimate coupling of UV and biodegradation accentuated the benefits of oxalic acid. - Abstract: Photo(cata)lysis coupled with biodegradation is superior to photo(cata)lysis or biodegradation alone for removal of recalcitrant organic compounds. The two steps can be carried out sequentially or simultaneously via intimate coupling. We studied nitrobenzene (NB) removal and mineralization to evaluate why intimate coupling of photolysis with biodegradation was superior to sequential coupling. Employing an internal circulation baffled biofilm reactor, we compared direct biodegradation (B), biodegradation after photolysis (P + B), simultaneous photolysis and biodegradation (P&B), and biodegradation with nitrophenol (NP) and oxalic acid (OA) added individually and simultaneously (B + NP, B + OA, and B + NP + OA); NP and OA were NB’s main UV-photolysis products. Compared with B, the biodegradation rate P + B was lower by 13–29%, but intimately coupling (P&B) had a removal rate that was 10–13% higher; mineralization showed similar trends. B + OA gave results similar to P&B, B + NP gave results similar to P + B, and B + OA + NP gave results between P + B and P&B, depending on the amount of OA and NP added. The photolysis product OA accelerated NB biodegradation through a co-substrate effect, but NP was inhibitory. Although decreasing the UV photolysis time could minimize the inhibition impact of NP in P + B, P&B gave the fastest removal of NB by accentuating the co-substrate effect of OA

  6. Action des pots catalytiques sur les polluants non réglementés How Catalytic Mufflers Act on Unregulated Pollutants

    Directory of Open Access Journals (Sweden)

    Degobert P.

    2006-11-01

    Full Text Available L'installation de pots catalytiques sur les véhicules, envisagée essentiellement pour réduire le niveau des polluants actuellement réglementés (oxyde de carbone, hydrocarbures imbrûlés, oxydes d'azote, aura-t-elle des effets bénéfiques ou néfastes sur les polluants non réglementés ? Pour éclaircir cette question, cette étude compare sur des véhicules les plus comparables possibles du point de vue conception et équipements, les émissions des voitures non dépolluées et celles de voitures dépolluées , c'est-à-dire équipées de pots catalytiques d'oxydation, de pots catalytiques multifonctionnels ou de systèmes de combustion en mélange pauvre. Les polluants non réglementés pris en considération sont les aldéhydes, les sulfates, l'anhydride sulfureux, l'hydrogène sulfuré, l'oxysulfure de carbone, le cyanogène, l'acide cyanhydrique, l'acide nitrique, les aromatiques légers, les hydrocarbures aromatiques polycycliques, ces derniers en liaison avec leurs propriétés mutagènes. Le catalyseur a été considéré dans différents états : neuf, vieilli, empoisonné : l'influence des déréglages des systèmes de contrôle (avance, sonde à oxygène, allumage, etc. a été prise en compte. Il apparaît que la présence de catalyseur fonctionnant dans des conditions normales se révèle en général bénéfique sur la majorité des polluants ou tout au moins indifférente sur certains polluants. En outre les déréglages éventuels n'entraîneraient pas de concentrations alarmantes de ces polluants non réglementés. Will the equipping of vehicles with catalytic mufflers, planned mainly to reduce the level of currently regulated pollutants (carbon monoxide, unburned hydrocarbons , nitrogen oxides, have a beneficial or harmful effect on unregulated pollutants? To elucidate this question this article considers the vehicles that are the most comparable possible from the standpoint of design and equipment to compare emissions

  7. 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

    Full Text Available Thermal coupling of methane or methane pyrolysis, which is a possible way for the direct chemical conversion of natural gas, can be used to produce ethylene, acetylene and benzene. But the high stability of methane requires a very high pyrolysis temperature (1200°C. To perform this reaction, IFP decided to build and elecric pilot furnace with an overall capacity of 10 m3/h. The design of this furnace is based on shell-and-tube heat exchanger technology with the use of new materials such as ceramics. This furnace has now been operating for more than one year without any noteworthy incident. First we will describe the technological and parametric study that has now been completed. In conclusion, we will make a short economic assessment of the production of ethylene and acetylene in France. Dans le domaine de la conversion du gaz naturel en hydrocarbures supérieurs, il nous a paru intéressant de reconsidérer la pyrolyse du méthane. Contrairement au couplage oxydant [1, 2], il s'agit d'une réaction très ancienne [3] n'ayant fait l'objet que de travaux épisodiques dans le passé [4, 5]. En effet, compte-tenu de sa réactivité très faible, le méthane doit être porté à très haute température, de l'ordre de 1 200°C, pour produire par couplage thermique principalement de l'éthylène de l'acétylène, du benzène, du coke et de l'hydrogène. Ce qui a gouverné notre démarche et la reprise de travaux sur cette réaction, était l'idée que les nouvelles technologies et spécialement les nouveaux matériaux réfractaires tels que les matériaux céramiques devaient permettre de réaliser de nouveaux designs de réacteurs pour mettre en oeuvre cette réaction. Lors d'une étude paramétrique préliminaire [8], réalisée sur un micro-pilote de faible capacité (50 l/h, nous avons pu obtenir des résultats intéressants, parmi lesquels nous avons sélectionné un bilan matière moyen , qui représente un compromis entre les imp

  8. Biodegradable Metals From Concept to Applications

    CERN Document Server

    Hermawan, Hendra

    2012-01-01

    This book in the emerging research field of biomaterials covers biodegradable metals for biomedical applications. The book contains two main parts where each of them consists of three chapters. The first part introduces the readers to the field of metallic biomaterials, exposes the state of the art of biodegradable metals, and reveals its application for cardiovascular implants. It includes some fundamental aspects to give basic understanding on metals for further review on the degradable ones is covered in chapter one. The second chapter introduces the concept of biodegradable metals, it's st

  9. Appropriation des Tic et performance des entreprises

    OpenAIRE

    Lethiais, Virginie; Smati, Wided

    2009-01-01

    L'utilisation des TIC (Technologies de l'information et de la Communication) se développe dans les entreprises pour assurer des tâches de plus en plus nombreuses : la communication, la recherche d'informations, la commercialisation des produits et services, le travail en groupe, la gestion de l'entreprise, la prospection, etc. Les équipements en TIC ainsi que l'usage qui en est fait diffèrent d'une entreprise à une autre selon de nombreux critères. L'objet de ce quatre pages est de déterminer...

  10. Celle des riches et celle des pauvres

    OpenAIRE

    Roussel, Bernard; Woldeyes, Feleke

    2013-01-01

    Les graines de la fausse cardamome kororima, Aframomum corrorima (Braun) Jansen, maniguette endémique d’Éthiopie, constituent une épice indispensable, emblématique du pays tout entier, aux usages multiples et quasi quotidiens. Plante spontanée des sous-bois des forêts humides du Kafa, c’est aussi une plante cultivée dans les jardins de diverses régions de l’Éthiopie méridionale.Cet article, à partir de l’analyse de la production et des filières de commercialisation de la kororima, se propose ...

  11. Biodegradation of surfactant bearing wastes

    International Nuclear Information System (INIS)

    In nuclear industry, during decontamination of protective wears and contaminated materials, detergents are employed to bring down the level of radioactive contamination within safe limits. However, the surfactant present in these wastes interferes in the chemical treatment process, reducing the decontamination factor. Biodegradation is an efficient and ecologically safe method for surfactant removal. A surfactant degrading culture was isolated and inoculated separately into simulated effluents containing 1% yeast extract and 5-100 ppm sodium lauryl sulphate (SLS) and 1% yeast extract and 5-100 ppm of commercial detergent respectively. The growth of the bacterial culture and the degradation characteristics of the surfactant in the above effluents were monitored under both dynamic and static conditions. (author). 6 refs., 6 figs., 1 tab

  12. New perspectives in plastic biodegradation.

    Science.gov (United States)

    Sivan, Alex

    2011-06-01

    During the past 50 years new plastic materials, in various applications, have gradually replaced the traditional metal, wood, leather materials. Ironically, the most preferred property of plastics--durability--exerts also the major environmental threat. Recycling has practically failed to provide a safe solution for disposal of plastic waste (only 5% out of 1 trillion plastic bags, annually produced in the US alone, are being recycled). Since the most utilized plastic is polyethylene (PE; ca. 140 million tons/year), any reduction in the accumulation of PE waste alone would have a major impact on the overall reduction of the plastic waste in the environment. Since PE is considered to be practically inert, efforts were made to isolate unique microorganisms capable of utilizing synthetic polymers. Recent data showed that biodegradation of plastic waste with selected microbial strains became a viable solution. PMID:21356588

  13. Engineered biosynthesis of biodegradable polymers.

    Science.gov (United States)

    Jambunathan, Pooja; Zhang, Kechun

    2016-08-01

    Advances in science and technology have resulted in the rapid development of biobased plastics and the major drivers for this expansion are rising environmental concerns of plastic pollution and the depletion of fossil-fuels. This paper presents a broad view on the recent developments of three promising biobased plastics, polylactic acid (PLA), polyhydroxyalkanoate (PHA) and polybutylene succinate (PBS), well known for their biodegradability. The article discusses the natural and recombinant host organisms used for fermentative production of monomers, alternative carbon feedstocks that have been used to lower production cost, different metabolic engineering strategies used to improve product titers, various fermentation technologies employed to increase productivities and finally, the different downstream processes used for recovery and purification of the monomers and polymers. PMID:27260524

  14. Biodegradation of halogenated organic compounds.

    Science.gov (United States)

    Chaudhry, G R; Chapalamadugu, S

    1991-03-01

    In this review we discuss the degradation of chlorinated hydrocarbons by microorganisms, emphasizing the physiological, biochemical, and genetic basis of the biodegradation of aliphatic, aromatic, and polycyclic compounds. Many environmentally important xenobiotics are halogenated, especially chlorinated. These compounds are manufactured and used as pesticides, plasticizers, paint and printing-ink components, adhesives, flame retardants, hydraulic and heat transfer fluids, refrigerants, solvents, additives for cutting oils, and textile auxiliaries. The hazardous chemicals enter the environment through production, commercial application, and waste. As a result of bioaccumulation in the food chain and groundwater contamination, they pose public health problems because many of them are toxic, mutagenic, or carcinogenic. Although synthetic chemicals are usually recalcitrant to biodegradation, microorganisms have evolved an extensive range of enzymes, pathways, and control mechanisms that are responsible for catabolism of a wide variety of such compounds. Thus, such biological degradation can be exploited to alleviate environmental pollution problems. The pathways by which a given compound is degraded are determined by the physical, chemical, and microbiological aspects of a particular environment. By understanding the genetic basis of catabolism of xenobiotics, it is possible to improve the efficacy of naturally occurring microorganisms or construct new microorganisms capable of degrading pollutants in soil and aquatic environments more efficiently. Recently a number of genes whose enzyme products have a broader substrate specificity for the degradation of aromatic compounds have been cloned and attempts have been made to construct gene cassettes or synthetic operons comprising these degradative genes. Such gene cassettes or operons can be transferred into suitable microbial hosts for extending and custom designing the pathways for rapid degradation of recalcitrant

  15. L'intérêt du forage horizontal pour l'exploitation de gisements d'hydrocarbures Advantages of Horizontal Drilling for Production from Hydrocarbon Fields

    OpenAIRE

    Giger F.; Combe J.; Reiss L. H.

    2006-01-01

    Pour les gisements de faible épaisseur, la longueur productive d'un puits horizontal est considérablement plus forte que celle d'un puits vertical. La productivité du puits horizontal croît avec la longueur de celui-ci, quoique plus lentement qu'elle, puisque intervient une loi pression-distance en logarithme. Les calculs analytiques et les simulations sur modèles numériques montrent que le gain de productivité peut atteindre couramment un facteur de 3 à 5. Dans des gisements comprenant des f...

  16. Preparation and degradation mechanisms of biodegradable polymer: a review

    Science.gov (United States)

    Zeng, S. H.; Duan, P. P.; Shen, M. X.; Xue, Y. J.; Wang, Z. Y.

    2016-07-01

    Polymers are difficult to degrade completely in Nature, and their catabolites may pollute the environment. In recent years, biodegradable polymers have become the hot topic in people's daily life with increasing interest, and a controllable polymer biodegradation is one of the most important directions for future polymer science. This article presents the main preparation methods for biodegradable polymers and discusses their degradation mechanisms, the biodegradable factors, recent researches and their applications. The future researches of biodegradable polymers are also put forward.

  17. Biodegradable polymers: Which, when and why?

    Directory of Open Access Journals (Sweden)

    Kotwal V

    2007-01-01

    Full Text Available The plethora of drug therapies and types of drugs demand different formulations, fabrications conditions and release kinetics. No single polymer can satisfy all the requirements. Therefore there have been tremendous advances in area of biodegradable copolymers over the last 30 years. This article reviews current research on biodegradable polymers, focusing their potential as drug carries. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Other degradable polymers such as polyorthoesters, polyanhydrides and polyphosphazenes are also discussed and their advantages and disadvantages are summarized.

  18. Biodegradable lubricants - ''the solution for future?''

    International Nuclear Information System (INIS)

    The environmental impact of lubricants use concern the direct effects from spills but also the indirect effects such as their lifetime and the emissions from thermal engines. The biodegradable performances and the toxicity are the environmental criteria that must be taken into account in the development and application of lubricants together with their technical performances. This paper recalls first the definition of biodegradable properties of hydrocarbons and the standardized tests, in particular the CEC and AFNOR tests. Then, the biodegradable performances of basic oils (mineral, vegetal, synthetic esters, synthetic hydrocarbons etc..), finite lubricants (hydraulic fluids..) and engine oils is analyzed according to these tests. Finally, the definition of future standards would take into account all the environmental characteristics of the lubricant: biodegradable performances, energy balance (CO2, NOx and Hx emissions and fuel savings), eco-toxicity and technical performances (wearing and cleanliness). (J.S.)

  19. Biodegradation of cresol isomers in anoxic aquifers.

    OpenAIRE

    Smolenski, W J; Suflita, J M

    1987-01-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers were preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradation of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol ...

  20. Biodegradation and toxicological evaluation of lubricant oils

    OpenAIRE

    Ivo Shodji Tamada; Paulo Renato Matos Lopes; Renato Nallin Montagnolli; Ederio Dino Bidoia

    2012-01-01

    The aim of this work was to compare different toxicity levels of lubricant oils. The tests were performed using the earthworm (Eisenia andrei), arugula seeds (Eruca sativa) and lettuce seeds (Lactuca sativa), with three types of contaminants (mineral lubricant oil, synthetic lubricant oil and used lubricant oil) for various biodegradation periods in the soil. The toxicity tests indirectly measured the biodegradation of the contaminants. The samples were analyzed at t0, t60, t120 and t180 days...

  1. Evolution des Geistes

    OpenAIRE

    Roth, Gerhard

    2004-01-01

    Evolution des Geistes Vortrag am 9. Februar 2003 im Rahmen der Reihe "Evolution – Entstehung der Erde bis zur Entfaltung des Geistes" des Zoologischen Museums Nach traditioneller Auffassung besitzt nur der Mensch Geist und Bewusstsein, und hierin besteht seine Einzigartigkeit. Aus Sicht der Hirnforschung und der Verhaltensbiologie haben sich jedoch während der tierischen Evolution Geist und Bewusstsein über viele Stufen entwickelt. Eine Reihe nichtmenschlicher Tiere, vor allem Säugetiere und ...

  2. Biodegradability of Chlorinated Anilines in Waters

    Institute of Scientific and Technical Information of China (English)

    CHAO WANG; GUAN-GHUA LU; YAN-JIE ZHOU

    2007-01-01

    Objective To identify the bacteria tolerating chlorinated anilines and to study the biodegradability of o-chloroaniline and its coexistent compounds. Methods Microbial community of complex bacteria was identified by plate culture observation techniques and Gram stain method. Bacterial growth inhibition test was used to determine the tolerance of complex bacteria to toxicant. Biodegradability of chlorinated anilines was determined using domesticated complex bacteria as an inoculum by shaking-flask test. Results The complex bacteria were identified, consisting of Xanthomonas, Bacillus alcaligenes,Acinetobacter, Pseudomonas, and Actinomycetaceae nocardia. The obtained complex bacteria were more tolerant to o-chloroaniline than mixture bacteria in natural river waters. The effects of exposure concentration and inoculum size on the biodegradability of o-chloroaniline were analyzed, and the biodegradation characteristics of single o-chloroaniline and 2,4-dichloroaniline were compared with the coexistent compounds. Conclusion The biodegradation rates can be improved by decreasing concentration of compounds and increasing inoculum size of complex bacteria. When o-chloroaniline coexists with aniline, the latter is biodegraded prior to the former, and as a consequence the metabolic efficiency of o-chloroaniline is improved with the increase of aniline concentration. Meanwhile, when o-chloroaniline coexists with 2,4-dichloroaniline, the metabolic efficiency of 2,4-dichloroaniline is markedly improved.

  3. Anatomie et identification des bois

    OpenAIRE

    Jourez, Benoît

    2010-01-01

    Anatomie des bois Structure anatomique des résineux et des feuillus Structure de la membrane cellulaire structure submicroscopique Anatomie du bois des essences feuillues tropicales Caractères anatomiques servant à l'identification des essences Reconnaissance microscopique du bois des essences résineuses et feuillues Duramen et duraminisation Formations anormales ( bois de compression et bois de tension) Chimie du bois Composition générale Cellulose, hé...

  4. Groupement des faits

    OpenAIRE

    Langlois, Charles-Victor; Seignobos, Charles

    2014-01-01

    I. La première nécessité qui s’impose à l’historien mis en présence du chaos des faits historiques, c’est de limiter son champ de recherches. Dans l’océan de l’histoire universelle quels faits choisira-t-il pour les recueillir ? – Puis, dans la masse des faits ainsi choisis, il lui faudra distinguer des groupes et faire des sections. – Enfin dans chacune de ces sections il aura à ranger les faits un à un. Ainsi toute construction historique doit commencer par trouver un principe pour trier, e...

  5. Gestion des risques

    CERN Document Server

    Louisot, Jean-Paul

    2009-01-01

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

  6. Are emerging deep eutectic solvents (DES) relevant for lipase-catalyzed lipophilizations?

    OpenAIRE

    Durand Erwann; Lecomte Jérôme; Villeneuve Pierre

    2015-01-01

    With the recent interest on green chemistry, the scientists have focused on developing new and more efficient solvents to carry out enzymatic-catalyzed reactions with emphasis on reduced costs, risks and toxicity while improving biodegradability. Among the new available solvents, the multimolecular-based liquids (such as ionic liquids and eutectic solvents) have been the subject of most recent studies. Currently, and mainly due to its environmental and economic features, DES are arousing much...

  7. Des Chiffres et des Lettres : distraction, variations, habitudes

    OpenAIRE

    Barbara Laborde

    2011-01-01

    Cet article envisage une des émissions les plus anciennes du Paysage Audiovisuel Français : Des Chiffres et des Lettres. La sérialité que l’émission met en œuvre au cours de son histoire est faite de variations qui témoignent à la fois des évolutions des techniques audiovisuelles, des logiques de programmations, des attentes spectatorielles. Ce jeu télévisé, toujours le même et pourtant toujours différent, permet à la fois la reconnaissance immédiate et la perception d'un changement, double a...

  8. Biodegradable compounds: Rheological, mechanical and thermal properties

    Science.gov (United States)

    Nobile, Maria Rossella; Lucia, G.; Santella, M.; Malinconico, M.; Cerruti, P.; Pantani, R.

    2015-12-01

    Recently great attention from industry has been focused on biodegradable polyesters derived from renewable resources. In particular, PLA has attracted great interest due to its high strength and high modulus and a good biocompatibility, however its brittleness and low heat distortion temperature (HDT) restrict its wide application. On the other hand, Poly(butylene succinate) (PBS) is a biodegradable polymer with a low tensile modulus but characterized by a high flexibility, excellent impact strength, good thermal and chemical resistance. In this work the two aliphatic biodegradable polyesters PBS and PLA were selected with the aim to obtain a biodegradable material for the industry of plastic cups and plates. PBS was also blended with a thermoplastic starch. Talc was also added to the compounds because of its low cost and its effectiveness in increasing the modulus and the HDT of polymers. The compounds were obtained by melt compounding in a single screw extruder and the rheological, mechanical and thermal properties were investigated. The properties of the two compounds were compared and it was found that the values of the tensile modulus and elongation at break measured for the PBS/PLA/Talc compound make it interesting for the production of disposable plates and cups. In terms of thermal resistance the compounds have HDTs high enough to contain hot food or beverages. The PLA/PBS/Talc compound can be, then, considered as biodegradable substitute for polystyrene for the production of disposable plates and cups for hot food and beverages.

  9. Bio-Degradable Plastics Impact On Environment

    Directory of Open Access Journals (Sweden)

    T.SUBRAMANI

    2014-06-01

    Full Text Available The potential of biodegradable polymers and more particularly that of polymers obtained from renewable resources such as the polysaccharides (e.g., starch have long been recognized. However, these biodegradable polymers have been largely used in some applications (e.g., food industry and have not found extensive applications in the packaging industries to replace conventional plastic materials, although they could be an interesting way to overcome the limitation of the petrochemical resources in the future. The fossil fuel and gas could be partially replaced by greener agricultural sources, which should participate in the reduction of CO2 emissions. Bio-based and biodegradable plastics can form the basis for environmentally preferable, sustainable alternative to current materials based exclusively on petroleum feed stocks. These bio-based materials offer value in the sustainability/life-cycle equation by being a part of the biological carbon cycle, especially as it relates to carbon-based polymeric materials such as plastics, water soluble polymers and other carbon based products like lubricants, biodiesel, and detergents. Identification and quantification of bio based content uses radioactive C-14 signature. Biopolymers are generally capable of being utilized by living matter (biodegraded, and so can be disposed in safe and ecologically sound ways through disposal processes (waste management like composting, soil application, and biological wastewater treatment. Single use, short-life, disposable products can be engineered to be bio-based and biodegradable.

  10. Des interfaces intelligentes pour les modèles de gisements Intelligent Interfaces for Reservoir Models

    Directory of Open Access Journals (Sweden)

    Zucchini P.

    2006-11-01

    Full Text Available Les codes de simulation numérique nécessitent souvent l'entrée de données nombreuses et variées. Nous présentons un programme interactif d'aide à la constitution d'un jeu de données pour un modèle de simulation de l'évolution des fluides dans un gisement d'hydrocarbures pendant son exploitation. Nous avons utilisé un moteur d'inférences et un générateur d'écrans de saisie pour écrire cette interface. Cette approche comporte de nombreux avantages concernant la qualité du logiciel produit : fiabilité, extensibilité, facilité d'utilisation, etc. L'utilisation combinée de règles d'expertise et d'un langage orienté objet offre de nouvelles perspectives qui sont étudiées. En conclusion, nous proposons l'extension de cette démarche pour développer une interface commune aux logiciels en Exploration - Production. Numerical simulation software often needs many input data having different natures. This article describes an interactive software that is of help in building the input data fill needed by oil reservoir simulators. A professional inference engine has been used to build this interface. This approach offers many advantages concerning the quality of the software produced, i. e. reliability, extensibility, user friendliness, etc. New prospects opened up by the mixed use of expertise rules and object-oriented languages are pointed out. The conclusion emphasizes the extension of this approach to the development of a common interface for exploration-production software.

  11. L'intérêt du forage horizontal pour l'exploitation de gisements d'hydrocarbures Advantages of Horizontal Drilling for Production from Hydrocarbon Fields

    Directory of Open Access Journals (Sweden)

    Giger F.

    2006-11-01

    Full Text Available Pour les gisements de faible épaisseur, la longueur productive d'un puits horizontal est considérablement plus forte que celle d'un puits vertical. La productivité du puits horizontal croît avec la longueur de celui-ci, quoique plus lentement qu'elle, puisque intervient une loi pression-distance en logarithme. Les calculs analytiques et les simulations sur modèles numériques montrent que le gain de productivité peut atteindre couramment un facteur de 3 à 5. Dans des gisements comprenant des fractures verticales parallèles, un puits horizontal disposé perpendiculairement à elles est susceptible d'en recouper un très grand nombre et d'apporter les gains de productivité beaucoup plus importants. Dans le cas des gisements très hétérogènes en perméabilité, tels que les gisements karstiques, le puits horizontal a de grandes chances de rencontrer des zones très productives (cas de Rospo Mare à gain de productivité de 10 et plus constaté par rapport aux puits verticaux voisins. Une étude menée sur la productivité globale à l'échelle du champ confirme que pour obtenir une même production dans des conditions équivalentes, le remplacement de puits verticaux par des puits horizontaux peut permettre d'en diviser le nombre par un facteur de l'ordre de 4. Pour la lutte contre les venues d'eau (ou de gaz en écoulement polyphasique, le puits horizontal présente deux avantages. II est possible de le placer en haut du gisement de façon à obtenir la garde à l'eau la plus importante. De plus, même avec une production totale supérieure, la. production linéique, ou production par unité de longueur, est plus faible, entraînant localement une sollicitation plus modérée de la surface de séparation huile/eau ou huile/gaz. La forme de cette dernière est donc plus molle et les calculs montrent que le balayage vertical est plus efficace, donc la récupération plus élevée. D'une façon générale, en écoulement polyphasique, les

  12. Biodegradable Photonic Melanoidin for Theranostic Applications.

    Science.gov (United States)

    Lee, Min-Young; Lee, Changho; Jung, Ho Sang; Jeon, Mansik; Kim, Ki Su; Yun, Seok Hyun; Kim, Chulhong; Hahn, Sei Kwang

    2016-01-26

    Light-absorbing nanoparticles for localized heat generation in tissues have various biomedical applications in diagnostic imaging, surgery, and therapies. Although numerous plasmonic and carbon-based nanoparticles with strong optical absorption have been developed, their clearance, potential cytotoxicity, and long-term safety issues remain unresolved. Here, we show that "generally regarded as safe (GRAS)" melanoidins prepared from glucose and amino acid offer a high light-to-heat conversion efficiency, biocompatibility, biodegradability, nonmutagenicity, and efficient renal clearance, as well as a low cost for synthesis. We exhibit a wide range of biomedical photonic applications of melanoidins, including in vivo photoacoustic mapping of sentinel lymph nodes, photoacoustic tracking of gastrointestinal tracts, photothermal cancer therapy, and photothermal lipolysis. The biodegradation rate and renal clearance of melanoidins are controllable by design. Our results confirm the feasibility of biodegradable melanoidins for various photonic applications to theranostic nanomedicines. PMID:26623481

  13. Biodegradable nanoparticles for gene therapy technology

    International Nuclear Information System (INIS)

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes

  14. Biodegradable Polymers and Stem Cells for Bioprinting

    Directory of Open Access Journals (Sweden)

    Meijuan Lei

    2016-04-01

    Full Text Available It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism.

  15. Biodegradable Polymers and Stem Cells for Bioprinting.

    Science.gov (United States)

    Lei, Meijuan; Wang, Xiaohong

    2016-01-01

    It is imperative to develop organ manufacturing technologies based on the high organ failure mortality and serious donor shortage problems. As an emerging and promising technology, bioprinting has attracted more and more attention with its super precision, easy reproduction, fast manipulation and advantages in many hot research areas, such as tissue engineering, organ manufacturing, and drug screening. Basically, bioprinting technology consists of inkjet bioprinting, laser-based bioprinting and extrusion-based bioprinting techniques. Biodegradable polymers and stem cells are common printing inks. In the printed constructs, biodegradable polymers are usually used as support scaffolds, while stem cells can be engaged to differentiate into different cell/tissue types. The integration of biodegradable polymers and stem cells with the bioprinting techniques has provided huge opportunities for modern science and technologies, including tissue repair, organ transplantation and energy metabolism. PMID:27136526

  16. Petroleum biodegradation and oil spill bioremediation

    International Nuclear Information System (INIS)

    Hydrocarbon-utilizing microorganisms are ubiquitously distributed in the marine environment following oil spills. These microorganisms naturally biodegrade numerous contaminating petroleum hydrocarbons, thereby cleansing the oceans of oil pullutants. Bioremediation, which is accomplished by adding exogenous microbial populations or stimulating indigenous ones, attempts to raise the rates of degradation found naturally to significantly higher rates. Seeding with oil degraders has not been demonstrated to be effective, but addition of nitrogenous fertilizers has been shown to increase rates of petroleum biodegradation. In the case of the Exxon Valdez spill, the largest and most thoroughly studied application of bioremediation, the application of fertilizer (slow release or oleophilic) increased rates of biodegradation 3-5 times. Because of the patchiness of oil, an internally conserved compound, hopane, was critical for demonstrating the efficacy of bioremediation. Multiple regression models showed that the effectiveness of bioremediation depended upon the amount of nitrogen delivered, the concentration of oil, and time. (author)

  17. Biodegradable nanoparticles for gene therapy technology

    Energy Technology Data Exchange (ETDEWEB)

    Hosseinkhani, Hossein, E-mail: hosseinkhani@mail.ntust.edu.tw; He, Wen-Jie [National Taiwan University of Science and Technology (Taiwan Tech), Graduate Institute of Biomedical Engineering (China); Chiang, Chiao-Hsi [School of Pharmacy, National Defense Medical Center (China); Hong, Po-Da [National Taiwan University of Science and Technology (Taiwan Tech), Graduate Institute of Biomedical Engineering (China); Yu, Dah-Shyong [Nanomedicine Research Center, National Defense Medical Center (China); Domb, Abraham J. [The Hebrew University of Jerusalem, Institute of Drug Research, School of Pharmacy, Faculty of Medicine, Center for Nanoscience and Nanotechnology and The Alex Grass Center for Drug Design and Synthesis (Israel); Ou, Keng-Liang [College of Oral Medicine, Taipei Medical University, Research Center for Biomedical Devices and Prototyping Production (China)

    2013-07-15

    Rapid propagations in materials technology together with biology have initiated great hopes in the possibility of treating many diseases by gene therapy technology. Viral and non-viral gene carriers are currently applied for gene delivery. Non-viral technology is safe and effective for the delivery of genetic materials to cells and tissues. Non-viral systems are based on plasmid expression containing a gene encoding a therapeutic protein and synthetic biodegradable nanoparticles as a safe carrier of gene. Biodegradable nanoparticles have shown great interest in drug and gene delivery systems as they are easy to be synthesized and have no side effect in cells and tissues. This review provides a critical view of applications of biodegradable nanoparticles on gene therapy technology to enhance the localization of in vitro and in vivo and improve the function of administered genes.

  18. Biodegradability Evaluation of Polymers by ISO 14855-2

    OpenAIRE

    Masao Kunioka; Fumi Ninomiya; Masahiro Funabashi

    2009-01-01

    Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradabi...

  19. Geopressure and Trap Integrity Predictions from 3-D Seismic Data: Case Study of the Greater Ughelli Depobelt, Niger Delta Pressions de pores et prévisions de l’intégrité des couvertures à partir de données sismiques 3D : le cas du grand sous-bassin d’Ughelli, Delta du Niger

    Directory of Open Access Journals (Sweden)

    Opara A.I.

    2012-05-01

    sous-sol, de déterminer la hauteur de la colonne d’hydrocarbures, la continuité du réservoir et l’intégrité du piège. Nos résultats montrent que les surpressions sont fréquentes dans les formations sédimentaires profondes abritant les réserves les plus prolifiques d’hydrocarbures du delta du Niger. La profondeur de la zone de surpressions légères (0.60 psi/ft varie de 3 000 m à 10 km. La répartition des surpressions augmente avec la profondeur et vers la partie centrale du bassin. La variation de la profondeur du sommet des surpressions est liée à la présence de failles et de diapirs d’argile. Le sommet des surpressions est ainsi moins profond en présence de diapirs. Les failles postérieures aux dépôts ont contrôlé la configuration de l’enveloppe des surpressions et jouent encore un rôle dans les modifications récentes de la profondeur des surpressions. Dans cette région, les surpressions sont souvent associées à des structures de glissement (roll-overs contrôlées par des failles de croissance, tandis que les pressions hydrostatiques sont observées dans les zones fracturées et au sommet des diapirs.

  20. Droit des organisations internationales

    CERN Document Server

    Sorel, Jean-Marc; Ndior, Valère

    2013-01-01

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

  1. Photonique des Morphos

    CERN Document Server

    Berthier, Serge

    2010-01-01

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

  2. Biodegradable polyesters based on succinic acid

    Directory of Open Access Journals (Sweden)

    Nikolić Marija S.

    2003-01-01

    Full Text Available Two series of aliphatic polyesters based on succinic acid were synthesized by copolymerization with adipic acid for the first series of saturated polyesters, and with fumaric acid for the second series. Polyesters were prepared starting from the corresponding dimethyl esters and 1,4-butanediol by melt transesterification in the presence of a highly effective catalyst tetra-n-butyl-titanate, Ti(0Bu4. The molecular structure and composition of the copolyesters was determined by 1H NMR spectroscopy. The effect of copolymer composition on the physical and thermal properties of these random polyesters were investigated using differential scanning calorimetry. The degree of crystallinity was determined by DSC and wide angle X-ray. The degrees of crystallinity of the saturated and unsaturated copolyesters were generally reduced with respect to poly(butylene succinate, PBS. The melting temperatures of the saturated polyesters were lower, while the melting temperatures of the unsaturated copolyesters were higher than the melting temperature of PBS. The biodegradability of the polyesters was investigated by enzymatic degradation tests. The enzymatic degradation tests were performed in a buffer solution with Candida cylindracea lipase and for the unsaturated polyesters with Rhizopus arrhizus lipase. The extent of biodegradation was quantified as the weight loss of polyester films. Also the surface of the polyester films after degradation was observed using optical microscopy. It could be concluded that the biodegradability depended strongly on the degree of crystallinity, but also on the flexibility of the chain backbone. The highest biodegradation was observed for copolyesters containing 50 mol.% of adipic acid units, and in the series of unsaturated polyesters for copolyesters containing 5 and 10 mol.% of fumarate units. Although the degree of crystallinity of the unsaturated polyesters decreased slightly with increasing unsaturation, the biodegradation

  3. Histological evaluation of different biodegradable and non-biodegradable membranes implanted subcutaneously in rats

    DEFF Research Database (Denmark)

    Zhao, S; Pinholt, E M; Madsen, J E; Donath, K

    2000-01-01

    Different types of biodegradable membranes have become available for guided tissue regeneration. The purpose of this study was to evaluate histologically three different biodegradable membranes (Bio-Gide, Resolut and Vicryl) and one non-biodegradable membrane (expanded polytetrafluoroethylene/e-PTFE...... that e-PTFE was well tolerated and encapsulated by a fibrous connective tissue capsule. There was capsule formation around Resolut and Vicryl and around Bio-Gide in the early phase there was a wide inflammatory zone already. e-PTFE and Vicryl were stable materials while Resolut and Bio-Gide fragmented...

  4. Biodegradable containers from green waste materials

    Science.gov (United States)

    Sartore, Luciana; Schettini, Evelia; Pandini, Stefano; Bignotti, Fabio; Vox, Giuliano; D'Amore, Alberto

    2016-05-01

    Novel biodegradable polymeric materials based on protein hydrolysate (PH), derived from waste products of the leather industry, and poly(ethylene glycol) diglycidyl ether (PEG) or epoxidized soybean oil (ESO) were obtained and their physico-chemical properties and mechanical behaviour were evaluated. Different processing conditions and the introduction of fillers of natural origin, as saw dust and wood flour, were used to tailor the mechanical properties and the environmental durability of the product. The biodegradable products, which are almost completely manufactured from renewable-based raw materials, look promising for several applications, particularly in agriculture for the additional fertilizing action of PH or in packaging.

  5. Biodegradable multifunctional oil production chemicals: Thermal polyaspartates

    International Nuclear Information System (INIS)

    The paper deals with biodegradable oil production chemicals. Control of both mineral scale and corrosion with a single, environmentally acceptable material is an ambitious goal. Polyaspartate polymers represent a significant milestone in the attainment of this goal. Thermal polyaspartates (TPA) are polycarboxylate polymers derived via thermal condensation of the naturally occurring amino acid aspartic acid. These protein-like polymers are highly biodegradable and non-toxic, and are produced by an environmentally benign manufacturing process. TPAs exhibit excellent mineral scale inhibition activity and CO2 corrosion control. Laboratory data on scale inhibition and corrosion control in the North Sea oil field production applications is presented. 8 refs., 2 figs., 6 tabs

  6. Synthetic biodegradable functional polymers for tissue engineering: a brief review

    OpenAIRE

    BaoLin, GUO; Ma, Peter X.

    2014-01-01

    Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glyce...

  7. Soluble Eggshell Mebrane Protein:Antibacterial Property and Biodegradability

    Institute of Scientific and Technical Information of China (English)

    YI Feng; YU Jian; LI Qiang; GUO Zhaoxia

    2007-01-01

    The antibacterial property and biodegradability of soluble eggshell membrane protein (SEP)are reported. Unlike the natural eggshell membrane (ESM), SEP does not possess antibacterial property against E.coli. The biodegradation tests with trypsin show that both ESM and SEP are biodegradable.

  8. Les savoirs des autres

    OpenAIRE

    Bromberger, Christian

    2007-01-01

    En ethnologie, comme dans bien d'autres domaines scientifiques, le renouvellement des problématiques est souvent venu des confins territoriaux, de points marginaux de rencontre entre disciplines voisines. Chacun de ces rendez-vous marque une étape importante dans l'histoire de la démarche ethnologique ; le dialogue qui s'est noué avec la technologie, la linguistique et la sémiologie, les sciences naturelles, la médecine... a permis non seulement une extension du champ et un affinement des mét...

  9. Des femmes au tribunal

    OpenAIRE

    Le Pape, Marc

    2010-01-01

    Les archives judiciaires constituent une source essentielle pour les études des sociabilités africaines en situation coloniale. Cet article prend appui sur l’analyse des procès tenus, entre 1923 et 1939, au tribunal du premier degré d’Abidjan, il vise à décrire les argumentations contradictoires par lesquelles femmes et hommes expliquent leurs différends dans l’espace du prétoire. Les registres issus des « juridictions indigènes » permettent également d’apprécier sur quels repères se fondent ...

  10. Liste des auteurs

    OpenAIRE

    2014-01-01

    Abdoul Razack Adjibi-Oualiou, agronome forestierdirection des Forêts et des Ressources naturellesBP 393, Cotonou, république du Béninmailto: Aristide Cossi Adomou, botanisteuniversité d’Abomey-Calavi, faculté des Sciences et Techniques département de Biologie végétaleHerbier national du Bénin, 01 BP 4521, Cotonou, république du Béninmailto: Pierre Onodjè Agbani, botaniste systématicien, écologuelaboratoire d'Écologie appliquée, Cotonou, république du B...

  11. Comparative study on the biodegradation and biocompatibility of silicate bioceramic coatings on biodegradable magnesium alloy as biodegradable biomaterial

    Science.gov (United States)

    Razavi, M.; Fathi, M. H.; Savabi, O.; Razavi, S. M.; Hashemibeni, B.; Yazdimamaghani, M.; Vashaee, D.; Tayebi, L.

    2014-03-01

    Many clinical cases as well as in vivo and in vitro assessments have demonstrated that magnesium alloys possess good biocompatibility. Unfortunately, magnesium and its alloys degrade too quickly in physiological media. In order to improve the biodegradation resistance and biocompatibility of a biodegradable magnesium alloy, we have prepared three types of coating include diopside (CaMgSi2O6), akermanite (Ca2MgSi2O6) and bredigite (Ca7MgSi4O16) coating on AZ91 magnesium alloy through a micro-arc oxidation (MAO) and electrophoretic deposition (EPD) method. In this research, the biodegradation and biocompatibility behavior of samples were evaluated in vitro and in vivo. The in vitro analysis was performed by cytocompatibility and MTT-assay and the in vivo test was conducted on the implantation of samples in the greater trochanter of adult rabbits. The results showed that diopside coating has the best bone regeneration and bredigite has the best biodegradation resistance compared to others.

  12. Architecture des contemplatifs

    OpenAIRE

    2005-01-01

    Architecture des contemplatifs. — Il serait nécessaire de comprendre un jour, et probablement ce jour est-il proche, ce qui manque avant tout à nos grandes villes : des lieux de silence, spacieux et forts étendus, destinés à la méditation, pourvus de hautes et de longues galeries pour les intempéries ou le trop ardent soleil, où ne pénètre nulle rumeur de voitures ni de crieurs, et où une bienséance plus subtile interdirait même au prêtre l’oraison à voix haute : des édifices et des jardins q...

  13. Dental Encounter System (DES)

    Data.gov (United States)

    Department of Veterans Affairs — Dental Encounter System (DES) is an automated health care application designed to capture critical data about the operations of VA Dental Services. Information on...

  14. Diethylstilbestrol (DES) and Cancer

    Science.gov (United States)

    ... been recommended that DES daughters have a yearly Pap test and pelvic exam to check for abnormal ... thorough examination may include the following: Pelvic examination Pap test and colposcopy —A routine cervical Pap test ...

  15. La descente des certitudes

    Directory of Open Access Journals (Sweden)

    Frédéric Lesemann

    2010-12-01

    Full Text Available Je rédige ce texte de discussion de la thèse de l’ouvrage de Robert Castel, La Montée des incertitudes, à Montréal, en août 2010. Ces précisions initiales ont pour but de situer d’où je parle : un pays nord-américain francophone où les travaux et la personne de Robert Castel sont connus et très appréciés dans le domaine des sciences sociales, et à un moment où la crise économique découlant des crises financières internationales des deux dernières années amène les gouvernements québécois et ca...

  16. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2010-01-01

    La chimie du vivant : enzymes et métalloenzymes, des biocatalyseurs fascinants La catalyse enzymatique, ce pouvoir que possèdent certaines protéines d’accélérer de façon extraordinaire et d’orienter avec une précision fascinante les réactions chimiques de la cellule, reste, encore aujourd’hui, l’un des grands mystères des systèmes vivants. Les réactions dont il est question vont de la simple hydrolyse de liaisons peptidiques à des processus poly-électroniques d’une très grande complexité, com...

  17. Organisation et pilotage des services sur le trajet des urgences

    OpenAIRE

    Wang, Tao

    2008-01-01

    L'exigence des soins à apporter aux patients accueillis aux urgences combinée au contexte économique impose aux établissements hospitaliers, surtout aux SAU, des décisions rapides ainsi que l'optimisation de l'emploi des ressources matérielles et humaines pour maintenir la fluidité des patients sans pour autant compromettre la qualité de soins. Nous proposons à travers ce mémoire de thèse des solutions appropriées aux services d'urgence permettant d'améliorer la prise en charge des urgences d...

  18. Un aspect nouveau de la prospection sismique en appliquant la théorie des sous-ensembles flous Improvement of Seismic Prospecting by Using Fuzzy Subsets Theory

    Directory of Open Access Journals (Sweden)

    Bois P.

    2006-11-01

    Full Text Available Durant les dix dernières années, la théorie des sous-ensembles flous a connu un intérêt croissant grâce aux travaux de Zadeh [1]. Cette théorie a vu son champ d'application s'étendre à différentes branches des mathématiques pures et appliquées en particulier à la topologie, à la théorie des graphes, des automates et à la reconnaissance des formes. Son but est d'analyser l'imprécision qui se glisse partout dans le comportement humain et dans la connaissance humaine. Cet article donne deux applications de la théorie des sous-ensembles flous à la prospection sismique. La première concerne l'interprétation d'une section sismique qui consiste à tracer une carte du sous-sol montrant la position des différents horizons sismiques situés au dessous de la surface du sol. Le problème qui se pose au sismicien est de trouver la structure géologique correspondante dans un plan vertical à la surface du sol. La seconde est la détermination de la nature des réservoirs contenant des hydrocarbures. On utilisera une méthode s'appuyant sur la reconnaissance des formes avec apprentissage préalable. Cette méthode consiste à comparer la nature d'un réservoir qui a été foré à celle d'un réservoir inconnu. Le réservoir connu joue le rôle du moniteur dans le processus d'apprentissage. Pour ce faire, un algorithme est conçu utilisant la méthode de Burg appliquée à des portions de traces sismiques représentatives des deux réservoirs. Enfin, une analyse floue des données représentant ces deux réservoirs sert de critère pour décider s'ils sont de nature identique ou différente. During the past decade, interest in fuzzy subsets theory has led to the development of a well-organized theory developed by Zadeh [1]. This theory has grown up, exploring and developing various branches of pure and applied mathematics, including topology, graph theory, mapping, automata and pattern recognition. Basically, the theory of fuzzy subsets

  19. Die Raumfahrtpolitik des Bundesforschungsministeriums

    OpenAIRE

    Weyer, Johannes

    2005-01-01

    Der vorliegende Beitrag befasst sich mit der Raumfahrtpolitik des Bundesforschungsministeriums. Zunächst wird auf die Raketenforschung der Nachkriegszeit 1945-1955 eingegangen. Im Anschluss wird der Aufbau einer forschungspolitischen Identität des Bundes auf dem Wege über die Weltraumforschung (1955-1969) nachgezeichnet. Im vierten Kapitel werden die Probleme und Herausforderungen der Raumfahrtpolitik (1969-1982) beleuchtet. Danach widmet sich der Autor der bemannten Raumfahrt und dem Aufbruc...

  20. Biodegradable polymers in clinical use and clinical development

    CERN Document Server

    Domb, Abraham J

    2011-01-01

    The definitive guide to biodegradable polymer science-where we are and what's to come The most comprehensive review of biodegradable polymers already utilized or under development for clinical use, Biodegradable Polymers in Clinical Use and Clinical Development looks at the state of biodegradable polymers now and over the next five years. Implantable molecules that break down within the body over a predetermined period of time, biodegradable polymers have been employed as drug carriers, orthopedic fixation devices, and absorbable sutures. Yet while hundreds of such polymers have been deve

  1. Biodegradation of chlorobenzoic acids by ligninolytic fungi

    Czech Academy of Sciences Publication Activity Database

    Muzikář, Milan; Křesinová, Zdena; Svobodová, Kateřina; Filipová, Alena; Čvančarová, Monika; Cajthamlová, Kamila; Cajthaml, Tomáš

    2011-01-01

    Roč. 196, - (2011), s. 386-394. ISSN 0304-3894 R&D Projects: GA MŠk 2B06156; GA ČR GA525/09/1058 Institutional research plan: CEZ:AV0Z50200510 Keywords : Chlorobenzoic acid * Polychlorinated biphenyls * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 4.173, year: 2011

  2. Fabrication of Environmentally Biodegradable Lignin Nanoparticles

    NARCIS (Netherlands)

    Frangville, C.; Rutkevicius, M.; Richter, A.P.; Velev, O.D.; Stoyanov, S.D.; Paunov, V.N.

    2012-01-01

    We developed a method for the fabrication of novel biodegradable nanoparticles (NPs) from lignin which are apparently non-toxic for microalgae and yeast. We compare two alternative methods for the synthesis of lignin NPs which result in particles of very different stability upon change of pH. The fi

  3. Natural Biodegradation of Phenolic Compounds in Groundwater

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A combination of field data and theoretical approaches is used to assess the natural attenuation and status of a complex plume of phenolic compounds (phenol, cresols, xylenols) in a deep, consolidated, UK Permo-Triassic sandstone aquifer. Biodegradation of the phenolic compounds at concentrations up to 12500mg·L-1 is occurring under aerobic, NO-3-reducing, Mn/Fe-reducing, SO2-4-reducing and methanogenic conditions in the aquifer, with the accumulation of inorganic and organic metabolites in the plume. An electron and carbon balance for the plume suggests that only 6% of the source term has been degraded in 50 years. The residual contaminant mass in the plume significantly exceeds estimates of electron acceptor inputs, indicating that the plume will grow. Two detailed vertical profiles through the plume show that contaminant distributions are controlled more by source history than by biodegradation processes. Microbiological and mass balance studies show that biodegradation is greatest at the plume fringe where contaminant concentrations are diluted by transverse mixing. Active bacterial populations exist throughout the plume but biodegradation is inhibited in the plume core by high contaminant concentrations. Stable isotope studies show that SO2-4-reduction is particularly sensitive to contaminant concentration. The aquifer is not oxidant-deficient but natural attenuation of the phenolic compounds in this system is limited by toxicity from the pollutant load and the bioavailability of electron acceptors. Natural attenuation of these contaminants will increase only after increased dilution of the plume.

  4. Biodegradable polymersomes for targeted ultrasound imaging

    NARCIS (Netherlands)

    Zhou, W.; Meng, F.; Engbers, G.H.M.; Feijen, J.

    2006-01-01

    Biodegradable polymersomes with a sub-micron size were prepared by using poly(ethylene glycol)–polylactide (PEG–PDLLA) block-copolymers in aqueous media. Air-encapsulated polymersomes could be obtained by a lyophilization/rehydration procedure. Preliminary results showed that these polymersomes were

  5. Transport of nonlinearly biodegradable contaminants in aquifers

    NARCIS (Netherlands)

    Keijzer, H.

    2001-01-01

    This thesis deals with the transport behavior of nonlinearly biodegradable contaminants in aquifers. Such transport occurs during in situ bioremediation which is based on the injection of an electron acceptor or electron donor. The main interests in this thesis are the mutual influences of underlyin

  6. Polyvinyl alcohol biodegradation under denitrifying conditions

    Czech Academy of Sciences Publication Activity Database

    Marušincová, H.; Husárová, L.; Růžička, J.; Ingr, M.; Navrátil, Václav; Buňková, L.; Koutný, M.

    2013-01-01

    Roč. 84, October (2013), s. 21-28. ISSN 0964-8305 Grant ostatní: GA ČR(CZ) GAP108/10/0200 Institutional support: RVO:61388963 Keywords : polyvinyl alcohol * biodegradation * denitrification * waste-water treatment * anaerobic * Steroidobacter Subject RIV: EI - Biotechnology ; Bionics Impact factor: 2.235, year: 2013

  7. Biodegradability of leathers through anaerobic pathway.

    Science.gov (United States)

    Dhayalan, K; Fathima, N Nishad; Gnanamani, A; Rao, J Raghava; Nair, B Unni; Ramasami, T

    2007-01-01

    Leather processing generates huge amounts of both solid and liquid wastes. The management of solid wastes, especially tanned leather waste, is a challenging problem faced by tanners. Hence, studies on biodegradability of leather become imperative. In this present work, biodegradability of untanned, chrome tanned and vegetable tanned leather under anaerobic conditions has been addressed. Two different sources of anaerobes have been used for this purpose. The effect of detanning as a pretreatment method before subjecting the leather to biodegradation has also been studied. It has been found that vegetable tanned leather leads to more gas production than chrome tanned leather. Mixed anaerobic isolates when employed as an inoculum are able to degrade the soluble organics of vegetable tanned material and thus exhibit an increased level of gas production during the initial days, compared to the results of the treatments that received the anaerobic sludge. With chrome tanned materials, there was not much change in the volume of the gas produced from the two different sources. It has been found that detanning tends to improve the biodegradability of both types of leathers. PMID:16740383

  8. Biodegradable synthetic polymers for tissue engineering

    Directory of Open Access Journals (Sweden)

    Gunatillake P. A.

    2003-05-01

    Full Text Available This paper reviews biodegradable synthetic polymers focusing on their potential in tissue engineering applications. The major classes of polymers are briefly discussed with regard to synthesis, properties and biodegradability, and known degradation modes and products are indicated based on studies reported in the literature. A vast majority of biodegradable polymers studied belongs to the polyester family, which includes polyglycolides and polylactides. Some disadvantages of these polymers in tissue engineering applications are their poor biocompatibility, release of acidic degradation products, poor processability and loss of mechanical properties very early during degradation. Other degradable polymers such as polyorthoesters, polyanhydrides, polyphosphazenes, and polyurethanes are also discussed and their advantages and disadvantages summarised. With advancements in tissue engineering it has become necessary to develop polymers that meet more demanding requirements. Recent work has focused on developing injectable polymer compositions based on poly (propylene fumarate and poly (anhydrides to meet these requirements in orthopaedic tissue engineering. Polyurethanes have received recent attention for development of degradable polymers because of their great potential in tailoring polymer structure to achieve mechanical properties and biodegradability to suit a variety of applications.

  9. Biodegradable Polymeric Microcapsules: Preparation and Properties

    NARCIS (Netherlands)

    Sawalha, H.I.M.; Schroën, C.G.P.H.; Boom, R.M.

    2011-01-01

    Biodegradable polymeric microcapsules can be produced through different methods of which emulsion solvent-evaporation/extraction is frequently used. In this technique, the polymer (often polylactide) is dissolved in a good solvent and is emulsified together with a poor solvent into a nonsolvent phas

  10. ENGINEERING BULLETIN: IN SITU BIODEGRADATION TREATMENT

    Science.gov (United States)

    In situ biodegradation may be used to treat low-to-intermediate concentrations of organic contaminants in place without disturbing or displacing the contaminated media. Although this technology has been used to degrade a limited number of inorganics, specifically cyanide and nitr...

  11. Biodegradable PEG-based drug carriers

    Czech Academy of Sciences Publication Activity Database

    Pechar, Michal; Braunová, Alena; Ulbrich, Karel; Jelínková, Markéta; Říhová, Blanka; Seymour, L. W.

    Glasgow : University of Strathclyde, 2005, s. 7-9. [Conference on New Approaches to Drug Delivery "Nanomedicines of the Future". Glasgow (GB), 18.11.2005] R&D Projects: GA MŠk 1M0505 Institutional research plan: CEZ:AV0Z40500505 Keywords : biodegradable polymers * drug carriers Subject RIV: EI - Biotechnology ; Bionics

  12. Taille des particules et catalyse Particle Size and Catalysis

    Directory of Open Access Journals (Sweden)

    Boitiaux J. P.

    2006-11-01

    Full Text Available Si la catalyse hétérogène et notamment la catalyse par les métaux se préoccupe de la taille des particules et donc de la surface développée, ce n'est pas seulement pour élaborer un produit efficace à moindre coût. L'étude des relations entre les caractéristiques des catalyseurs et leurs propriétés vis-à-vis des réactions a permis d'arriver dans certains cas à une description quasi atomique du site actif spécifique de chaque réaction. Les approches de ce problème qu'ont eu les différents auteurs sont différentes : l'une a consisté à prendre en considération les propriétés cristallographiques des métaux massiques, l'autre à considérer que les petites particules n'ont ni les propriétés, ni la structure du métal massif. L'approche cristallographique a d'abord conduit à prendre en compte les paramètres des cristaux et à distinguer les différents atomes situés en coins, arêtes ou faces. Mais très vite on s'est rendu compte que les particules n'avaient pas les structures attendues. On s'est donc intéressé au calcul de l'énergie des particules considérées pour imaginer comment elles pouvaient se construire à partir d'un petit noyau. Ces calculs ne tenaient compte ni de l'atmosphère en contact avec la particule, ni de la présence d'un support, ni des perturbations apportées par la réaction. En effet selon la réaction étudiée, on a pu définir des réactions facilesou insensibles à la structure et des réactions exigeantesdont la vitesse intrinsèque varie avec la structure de surface. Beaucoup de travaux ont été effectués sur des monocristaux dont les surfaces exposées avaient des indices différents et d'autres ont tenté d'étudier ces relations avec des métaux supportés, avec tous les artefacts que cela pouvait amener. Il a été difficile de trouver une unité dans tous les résultats obtenus et ceci d'autant plus que les phénomènes d'auto empoisonnement par les réactifs (hydrocarbures ou

  13. La revolution des savants

    CERN Document Server

    Chavanne, A

    1989-01-01

    Premiere cassette : - 1666 : impact de la creation de l'Academie des Sciences par Colbert, trente ans apres le proces de Galile, et au moment des disparitions de Pascal, Descartes et Fermat. Elle dirigee par le hollandais Huyggens jusqu'a sa fuite de France au moment de la revocation de l'Edit de Nantes. - 1750 : l'Encyclopedie (ou "Dictionnaire raisonne des Sciences, des Arts et des Metiers") de Diderot et d'Alembert, soutenus par Malherbes, Buffon, Condorcet et Rousseau. - 1789 : Revolution francaise. - 8 aout 1793 : l'Assemblee, par une declaration de Marat, dissout l'Academie des Sciences. Celle-ci continue cependant ses travaux pour les poids et mesures jusqu'en 1795. - la Terreur : la condamnation a mort, pas au nom d'une "Revolution qui n'a pas besoin de savants" mais pour d'autres raisons, de trois grands hommes de science : Lavoisier, Bailly et Condorcet. - 1793-1794 : Au printemps 93, le Comite de Salut Publique s'inquiete du demi-million de soldats etrangers de toutes les pays frontaliers qui essai...

  14. Biodegradation of acetanilide herbicides acetochlor and butachlor in soil.

    Science.gov (United States)

    Ye, Chang-ming; Wang, Xing-jun; Zheng, He-hui

    2002-10-01

    The biodegradation of two acetanilide herbicides, acetochlor and butachlor in soil after other environmental organic matter addition were measured during 35 days laboratory incubations. The herbicides were applied to soil alone, soil-SDBS (sodium dodecylbenzene sulfonate) mixtures and soil-HA (humic acid) mixtures. Herbicide biodegradation kinetics were compared in the different treatment. Biodegradation products of herbicides in soil alone samples were identified by GC/MS at the end of incubation. Addition of SDBS and HA to soil decreased acetochlor biodegradation, but increased butachlor biodegradation. The biodegradation half-life of acetochlor and butachlor in soil alone, soil-SDBS mixtures and soil-HA mixtures were 4.6 d, 6.1 d and 5.4 d and 5.3 d, 4.9 d and 5.3 d respectively. The biodegradation products were hydroxyacetochlor and 2-methyl-6-ethylaniline for acetochlor, and hydroxybutachlor and 2,6-diethylaniline for butachlor. PMID:12491727

  15. Improving the biodegradative capacity of subsurface bacteria

    International Nuclear Information System (INIS)

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates

  16. Biodegradation of natural oils in seawater

    Energy Technology Data Exchange (ETDEWEB)

    Al-Darbi, M.M.; Saeed, N.O.; Islam, M.R. [Dalhousie University, Halifax, NS (Canada). Faculty of Engineering; Lee, K. [Bedford Institute of Oceanography, Dartmouth, NS (Canada)

    2005-01-15

    Spills of non-petroleum hydrocarbons including oils and fish oils are of environmental concern because of their potential to cause serious effects on marine life and coastal environments. Biodegradation by indigenous microorganisms is an important and potentially ubiquitous process affecting both the chemical composition and physical properties of contaminant oils. Data on the environmental persistence of non-petroleum oils is now required for risk assessments and decision making by spill responders. This article investigates the biodegradability of various vegetable and fish oils under the influence of natural bacteria in seawater. The influence of nutrients and microbial environment on changes in bacterial numbers and the extent and rate of degradation for various test oils (olive, mustard, canola and cod liver oils) were studied over time. Time-series visual and microscopic observations were made to characterize physical changes in the residual oils, formation of floating and precipitate particles, oil droplets and dispersion. The biodegradation process was significantly influenced by environmental conditions, with a higher rate and extent of biodegradation observed in seawater amended with nutrients and wastewater that contained elevated numbers of bacteria and nutrients. It was observed that different oils respond in different rates and extents to biodegradation depending on their stability, viscosity and compositions. All results clearly revealed a significant response of the oil-contaminated samples to both the seawater and wastewater environments. Observations on changes in the physical properties of the residual oil may be important in the context of oil spill response strategies. For example, simple physical recovery methods may be used to recover polymeric lumps at the sea surface. (author)

  17. Improving the biodegradative capacity of subsurface bacteria

    Energy Technology Data Exchange (ETDEWEB)

    Romine, M.F.; Brockman, F.J.

    1993-04-01

    The continual release of large volumes of synthetic materials into the environment by agricultural and industrial sources over the last few decades has resulted in pollution of the subsurface environment. Cleanup has been difficult because of the relative inaccessibility of the contaminants caused by their wide dispersal in the deep subsurface, often at low concentrations and in large volumes. As a possible solution for these problems, interest in the introduction of biodegradative bacteria for in situ remediation of these sites has increased greatly in recent years (Timmis et al. 1988). Selection of biodegradative microbes to apply in such cleanup is limited to those strains that can survive among the native bacterial and predator community members at the particular pH, temperature, and moisture status of the site (Alexander, 1984). The use of microorganisms isolated from subsurface environments would be advantageous because the organisms are already adapted to the subsurface conditions. The options are further narrowed to strains that are able to degrade the contaminant rapidly, even in the presence of highly recalcitrant anthropogenic waste mixtures, and in conditions that do not require addition of further toxic compounds for the expression of the biodegradative capacity (Sayler et al. 1990). These obstacles can be overcome by placing the genes of well-characterized biodegradative enzymes under the control of promoters that can be regulated by inexpensive and nontoxic external factors and then moving the new genetic constructs into diverse groups of subsurface microbes. ne objective of this research is to test this hypothesis by comparing expression of two different toluene biodegradative enzymatic pathways from two different regulatable promoters in a variety of subsurface isolates.

  18. Hydrocarbons biodegradation in unsaturated porous medium

    International Nuclear Information System (INIS)

    Biological processes are expected to play an important role in the degradation of petroleum hydrocarbons in contaminated soils. However, factors influencing the kinetics of biodegradation are still not well known, especially in the unsaturated zone. To address these biodegradation questions in the unsaturated zone an innovative experimental set up based on a physical column model was developed. This experimental set up appeared to be an excellent tool for elaboration of a structured porous medium, with well defined porous network and adjusted water/oil saturations. Homogeneous repartition of both liquid phases (i.e., aqueous and non aqueous) in the soil pores, which also contain air, was achieved using ceramic membranes placed at the bottom of the soil column. Reproducible interfaces (and connectivity) are developed between gas, and both non mobile water and NAPL phases, depending on the above-defined characteristics of the porous media and on the partial saturations of these three phases (NAPL, water and gas). A respirometric apparatus was coupled to the column. Such experimental set up have been validated with hexadecane in dilution in an HMN phase. This approach allowed detailed information concerning n-hexadecane biodegradation, in aerobic condition, through the profile of the oxygen consumption rate. We have taken benefit of this technique, varying experimental conditions, to determine the main parameters influencing the biodegradation kinetics and compositional evolution of hydrocarbons, under steady state unsaturated conditions and with respect to aerobic metabolism. Impacts of the nitrogen quantity and of three different grain sizes have been examined. Biodegradation of petroleum cut, as diesel cut and middle distillate without aromatic fraction, were, also studied. (author)

  19. Biodegradation of organic pollutants. Metabolism, risk assessment, bio-remediation and bio-detection; La biodegradation des polluants organiques. Metabolisme, estimation des risques, depollution et biodetection

    Energy Technology Data Exchange (ETDEWEB)

    Ouazzani, J. [Institut de Chimie des Substances Naturelles, UPR CNRS, 91 - Gif-sur-Yvette (France)

    2002-09-01

    The presence of toxic organic pollutants in soils and aquifers contribute to the development of highly resistant microorganisms. This resistance is the consequence of partial or total degradation of the pollutant by enzymes. Elucidation of enzymatic mechanisms and identification of the metabolites help to predict the impact of the pollution on public health and environment, and the urgency of prevention and remediation processes. Based on a representative and accurate example, this paper describes both fundamental and applied benefits in investigating microbial degradation of organic pollutants. (authors)

  20. Agroforesterie, des arbres et des cultures

    OpenAIRE

    dupraz, Christian; Liagre, Fabien

    2008-01-01

    Des arbres dans nos parcelles cultivées ? Pourquoi pas ! Depuis un siècle, ils ont été systématiquement retirés des parcelles agricoles. Pourtant, de plus en plus, on étudie leur valeur ajoutée en matière : de sols et pour les différentes productions végétales, de biodiversité, de protection de l'environnement, de qualité de l'eau (bilan hydrique). Les auteurs, dans une première partie, exposent les données pour comprendre le fonctionnement d'une parcelle agroforestière. Ils donnent, dans une...

  1. Rachid Santaki, Des chiffres et des litres

    OpenAIRE

    Harzoune, Mustapha

    2013-01-01

    Avec Des chiffres et des litres, Rachid Santaki signe un roman qui s’inscrit dans la pure tradition du néo-polar. Nous sommes en 1998, la Coupe du monde de football mobilise l’attention du pays. Hachim, un jeune de Saint-Denis intelligent et sensible, doué pour les études souhaite faire carrière dans le journalisme mais s’embarque dans une galère qui n’est pas faite pour lui : le deal de shit. Il faut savoir pourtant rester à sa place, ne pas jouer les gros durs quand on a une “gueule de prem...

  2. Caractérisation préliminaire à partir de la lagune de Bizerte (Tunisie) des bactéries tolérantes aux hydrocarbures aromatiques polycliques (HAPS)

    OpenAIRE

    Duran, R.; El Bour, M.; Ben Said, O.; Goni, M. S.; Dalleli, M.; Aissa, P

    2007-01-01

    م إنجاز هذه الدراسة لهدف عَزَلَ بَكْتِيريَا قادرة على استعمالتم إنجاز هذه الدراسة لهدف عَزَلَ بَكْتِيريَا قادرة على استعمال الهيدروكربنات و مقاومة للمعادن والمضادات الحيوية و في هذا الإطار تم أخذ عينات من الماء و التربة على مستوى 16محطة موزعة ببحيرة بنزرت. كما تم عزل البكتيريا بطريقة الإثراء باستعمال وسط مائي معدني زائد هيدروكربنات (fluoranthène) وقد توصلنا في عملية أولية من عزل 130 من الأجذال المختلفة من البكتيريا والتي تم تعريفها عبر الخاصيات الشكلية و البيوكيميائية. وأثبتت النتا...

  3. Re-mobilisation des hydrocarbures aromatiques polycycliques de terres industrielles de cokerie et mécanismes impliqués dans le "vieillissement" du fluoranthène

    OpenAIRE

    Vessigaud, Sandrine

    2007-01-01

    PAH are persistent organic pollutants in soils. In the framework of industrial waste lands rehabilitation, one needs to understand the reasons of their strong retention and to assess their potential for water remobilization. For these purposes, the remobilization potential of industrial polluted matrices was assessed during 6 months in closed reactors with a monthly renewal of the solution. Adsorption / desorption experiments with 14C-fluoranthene on the same matrices and an agricultural soil...

  4. Coke Formation During Hydrocarbons Pyrolysis. Part Two: Methane Thermal Cracking Formation de coke pendant la pyrolyse des hydrocarbures. Deuxième partie : pyrolyse du méthane

    OpenAIRE

    Billaud F.; Broutin P.; Busson C.; Gueret C.

    2006-01-01

    Part one of this article dealt with coking in a steam cracking furnace. In this process, coke deposition is a very complex phenomenon due to the number of parameters involved. Nevertheless, for this process, coke deposition is a secondary reaction which does not affect steam cracking yields. It is completely different for methane thermal cracking. Coke is one of the main products of this reaction. Part two of this article deals with coke deposition on the walls of the reactors used for methan...

  5. Geostatistical characterization of soil pollution at industrial sites Case of polycyclic aromatic hydrocarbons at former coking plants; Caracterisation geostatistique de pollutions industrielles de sols cas des hydrocarbures aromatiques polycycliques sur d'anciens sites de cokeries

    Energy Technology Data Exchange (ETDEWEB)

    Jeannee, N.

    2001-05-15

    Estimating polycyclic aromatic hydrocarbons concentrations in soil at former industrial sites poses several practical problems on account of the properties of the contaminants and the history of site: 1)collection and preparation of samples from highly heterogeneous material, 2) high short scale variability, particularly in presence of backfill, 3) highly contrasted grades making the vario-gram inference complicated. The sampling strategy generally adopted for contaminated sites is based on the historical information. Systematic sampling recommended for geostatistical estimation is often considered to be excessive and unnecessary. Two former coking plants are used as test cases for comparing several geostatistical methods for estimating (i) in situ concentrations and (ii) the probability that they are above a pollution threshold. Several practical and methodological questions are considered: 1) the properties of various estimators of the experimental vario-gram and the validity of the results; 2) the use of soft data, such as historical information, organoleptic observations and semi-quantitative methods, with a view to improve the precision of the estimates; 3) the comparison of standard sampling strategies, taking into account vertical repartition of grades and the history of the site. Multiple analyses of the same sample give an approximation of the sampling error. Short scale sampling shows the difficulty of selecting soils in the absence of a spatial structure. Sensitivity studies are carried out to assess how densely sampled soft data can improve estimates. By using mainly existing models, this work aims at giving practical recommendations for the characterization of soil pollution. (author)

  6. Deep catalytic oxidation of heavy hydrocarbons on Pt/Al{sub 2}O{sub 3} catalysts; Oxydation catalytique totale des hydrocarbures lourds sur Pt/Al{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Diehl, F.

    1998-12-09

    Deep oxidation by air on Pt supported on alumina of a large number of heavy hydrocarbons representative of those found in a real Diesel car exhaust has been studied. Light-off temperatures between 140 and 320 deg. C on 1%Pt/alumina (80% metal dispersion) have been found. Results show that not only the physical state around the conversion area but also the chemical nature of the hydrocarbon plays an important role. Heavy hydrocarbons deep oxidation behaviour has been classified as a function of their chemical category (alkane, alkene, aromatics etc..). Oxidation of binary mixtures of hydrocarbons has shown strong inhibition effects on n-alkane or CO oxidation by polycyclic compounds like 1-methyl-naphthalene. In some cases, by-product compounds in the gas effluent (other than CO{sub 2} and H{sub 2}O) have been identified by mass-spectrometry leading to oxidation mechanism proposals for different hydrocarbons. Catalyst nature (metal dispersion, content) influence has also been studied. It is shown that turn-over activity is favoured by the increase of the metal bulk size. Acidity influence of the carrier has shown only very little influence on n-alkane or di-aromatic compound oxidation. (author)

  7. Non au gaz de schiste ! : cadrages et débordements de la controverse sur les hydrocarbures non conventionnels en France et au Québec

    OpenAIRE

    Chailleux, Sébastien

    2015-01-01

    L’analyse de la controverse sur le gaz de schiste en France et au Québec à un niveauintermédiaire (méso) permet de souligner les processus de construction et contestation sociale etpolitique des différents cadrages soutenus par les réseaux d’acteurs en concurrence. Lesdynamiques d’intéressement à l’intérieur et à l’extérieur de l’action publique illustrent lesmultiples scènes et forums dans lesquels se déploie la controverse. L’analyse de la construction dece problème public et ses diverses r...

  8. Surface Modification of Biodegradable Polymers towards Better Biocompatibility and Lower Thrombogenicity.

    Directory of Open Access Journals (Sweden)

    Andreas Rudolph

    Full Text Available Drug-eluting stents (DES based on permanent polymeric coating matrices have been introduced to overcome the in stent restenosis associated with bare metal stents (BMS. A further step was the development of DES with biodegradable polymeric coatings to address the risk of thrombosis associated with first-generation DES. In this study we evaluate the biocompatibility of biodegradable polymer materials for their potential use as coating matrices for DES or as materials for fully bioabsorbable vascular stents.Five different polymers, poly(L-lactide PLLA, poly(D,L-lactide PDLLA, poly(L-lactide-co-glycolide P(LLA-co-GA, poly(D,L-lactide-co-glycolide P(DLLA-co-GA and poly(L-lactide-co-ε-caprolactone, P(LLA-co-CL were examined in vitro without and with surface modification. The surface modification of polymers was performed by means of wet-chemical (NaOH and ethylenediamine (EDA and plasma-chemical (O2 and NH3 processes. The biocompatibility studies were performed on three different cell types: immortalized mouse fibroblasts (cell line L929, human coronary artery endothelial cells (HCAEC and human umbilical vein endothelial cells (HUVEC. The biocompatibility was examined quantitatively using in vitro cytotoxicity assay. Cells were investigated immunocytochemically for expression of specific markers, and morphology was visualized using confocal laser scanning (CLSM and scanning electron (SEM microscopy. Additionally, polymer surfaces were examined for their thrombogenicity using an established hemocompatibility test.Both endothelial cell types exhibited poor viability and adhesion on all five unmodified polymer surfaces. The biocompatibility of the polymers could be influenced positively by surface modifications. In particular, a reproducible effect was observed for NH3-plasma treatment, which enhanced the cell viability, adhesion and morphology on all five polymeric surfaces.Surface modification of polymers can provide a useful approach to enhance their

  9. Histoire intellectuelle des droits humains

    OpenAIRE

    Zuber, Valentine

    2014-01-01

    Sous le titre générique « Histoire intellectuelle des droits humains », le séminaire de l’année 2012-2013 a été tout spécialement consacré aux origines spécifiquement religieuses des grands textes des droits de l’homme contemporains.

  10. Un modèle de production associée des secteurs du raffinage et de la pétrochimie de base An Associated Production Model for the Refining and Basic Petrochemical Sectors

    Directory of Open Access Journals (Sweden)

    Pennegues G.

    2006-11-01

    Full Text Available Cet article présente une application du modèle de production et de transformation de l'énergie de l'Institut Français du Pétrole (lFP. La présente étude de modélisation s'attache plus précisément à l'analyse par programmation linéaire dynamique des conditions optimales de production des secteurs français du raffinage et de la pétrochimie de base. S'armant de scénarios d'approvisionnement et de demandes de produits, cette étude se propose de décrire les investissements optimaux de ces deux secteurs pour les deux décennies à venir. Des hypothèses particulières de diésélisation du parc des véhicules routiers et d'introduction d'hydrocarbures oxygénés dans les carburants automobiles ont été formulées, ainsi que des tendances contrastées de consommation des produits pétrochimiques de base. Une brève étude de paramétrisation clôt cet article, en présentant une approche statique de l'influence que pourrait avoir une substitution propylène-éthylène au niveau de la demande, sur les outils de production des deux secteurs. This article describes an application of the lFP energy production and transformation model. The present mode-ing study specifically aims to use dynamic linear programming to analyze the optimum production conditions for the French refining and basic petrochemical sectors. On the basis of product supply and demand scenarios, this study attempts to describe optimum investments for these two sectors for the next two decades. Special assumptions concerning the dieselization of road vehicles and the inclusion of oxygenated hydrocarbons in automotive fuels have been formulated along with contrasting trends in the consumption of basic petrochemical products. The article concludes with a brief parameterization study giving a static approach to the influence that a propylene/ethylene substitution might have, at the level of the demand, on the production facilities of both sectors.

  11. Le statut vitaminique des individus et des populations…

    Directory of Open Access Journals (Sweden)

    Icart Jean-Claude

    2000-05-01

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

  12. Controlled morphology of biodegradable polymer blends

    Science.gov (United States)

    Buddhiranon, Sasiwimon; Kyu, Thein

    2009-03-01

    Phase diagrams of biodegradable polymer blends containing poly(ɛ-caprolactone) (PCL) and poly(d,l-lactic acid) (PDLLA) having two different molecular weights were established by means of cloud point measurement and differential scanning calorimetry. Subsequently, the theoretical phase diagram was calculated self-consistently based on the combination of Flory-Huggins free energy for liquid-liquid phase separation and phase field free energy for crystal solidification. The phase diagrams thus obtained were LCST type or hour-glass type, which depended on molecular weight of PDLLA utilized. Guided by the phase diagram, the emerged morphology was determined as a function of blend concentration and temperature. It appears that the morphology control is feasible that ultimately affects the end-use property of PCL/PDLLA blends. A wide variety of morphology of biodegradable polymer may be developed with the porous structure and pore size to control scaffold porosity and the rate of drug delivery.

  13. Starch-based completely biodegradable polymer materials

    Directory of Open Access Journals (Sweden)

    2009-06-01

    Full Text Available Starch is a natural polymer which possesses many unique properties and some shortcoming simultaneously. Some synthetic polymers are biodegradable and can be tailor-made easily. Therefore, by combining the individual advantages of starch and synthetic polymers, starch-based completely biodegradable polymers (SCBP are potential for applications in biomedical and environmental fields. Therefore it received great attention and was extensively investigated. In this paper, the structure and characteristics of starch and some synthetic degradable polymers are briefly introduced. Then, the recent progress about the preparation of SCBP via physical blending and chemical modification is reviewed and discussed. At last, some examples have been presented to elucidate that SCBP are promising materials for various applications and their development is a good solution for reducing the consumption of petroleum resources and environmental problem.

  14. Biodegradable Epoxy Networks Cured with Polypeptides

    Science.gov (United States)

    Nakamura, Shigeo; Kramer, Edward J.

    2006-03-01

    Epoxy resins are used widely for adhesives as well as coatings. However, once cured they are usually highly cross-linked and are not biodegradable. To obtain potentially biodegradable polypeptides that can cure with epoxy resins and achieve as good properties as the conventional phenol novolac hardeners, poly(succinimide-co-tyrosine) was synthesized by thermal polycondensation of L-aspartic acid and L-tyrosine with phosphoric acid under reduced pressure. The tyrosine/succinimide ratio in the polypeptide was always lower than the tyrosine/(aspartic acid) feed ratio and was influenced by the synthesis conditions. Poly(succinimide-tyrosine- phenylalanine) was also synthesized from L-aspartic acid, L- tyrosine and L-phenylalanine. The thermal and mechanical properties of epoxy resins cured with these polypeptides are comparable to those of similar resins cured with conventional hardeners. In addition, enzymatic degradability tests showed that Chymotrypsin or Subtilisin A could cleave cured films in an alkaline borate buffer.

  15. Table des documents

    OpenAIRE

    2015-01-01

    Tableaux Sommes octroyées en don par le roi à la ville de Poitiers (1418-1429) 56 Sommes octroyées en don par le roi à la ville de Tours (1421-1422) 56 Sommes octroyées en don par le roi à la ville de Tours (1422-1432) pour le payement des délégations communales 57 Répartition chronologique des ambassades urbaines de Tours et Poitiers vers le roi (1438-1461) 76 Les groupes d'opinions à Bourges le 26 avril 1474 93 Rapport des octrois royaux à la ville de Bourges entre 1487 et 1535 (en moyennes...

  16. Table des figures

    OpenAIRE

    2015-01-01

    Figure n° 1 : Nombre de traités sur la culture des arbres fruitiers publiés en français à l’époque moderne 30 Figure n° 2 : Un exemple de plagiat, la vraie fausse nouvelle instruction pour la culture des figuiers 33 Figure n° 3 : Nombre d’espèces fruitières sélectionnées dans les traités horticoles parisiens (xviie-xviiie siècles) 65 Figure n° 4 : Nombre d’espèces fruitières proposées à la vente dans les catalogues des pépiniéristes parisiens (xviiie-début xixe s.) 65 Figure n° 5 : Les ustens...

  17. Table des illustrations

    OpenAIRE

    2015-01-01

    Intégrer les Tsiganes Hongrie, 1970 (photo DR) 34 Discuter entretient la fraternité. (photo M. Stewart) 35 La veille du mariage (photo M. Stewart) 36 Le « salon » (photo M. Stewart) 37 Les activités économiques des Tsiganes sont conçues comme des jeux. (photo M. Stewart) 39 Lev cheval (photo I. Nemeth) 41 Le cortège d’un mariage (photo M. Stewart) 43 Avant le mariage (photo M. Stewart) 43 C’est par le chant (photo M. Stewart) 45 Des « frères » boivent en harmonie (photo M. Stewart) 46 Les che...

  18. Les lueurs des sables

    CERN Multimedia

    Les lueurs des sables

    2013-01-01

    Two CERN ladies are getting ready for the “Trophée Roses des Sables” rally adventure: Julie and Laetitia are finalizing the last details before setting off on Monday 7th October 2013. Julie from EN-MEF group and Laetitia from DGS-SEE group, met at the CERN Rugby club. This year, they are participating in the 100 % female rally which will take place in Morocco from 10 to 20 October. They will be carrying along 100 kg of humanitarian donation for children such as some clothes, books and medical material. Do not hesitate to show your support at their farewell party to be held on Monday 7 October, from 4 to 6 pm in front of the St Genis-Pouilly Mairie (city Hall). Follow their exciting adventure on the blog leslueursdessables.trophee-roses-des-sables.org and on their association’s Facebook page Les Lueurs des Sables.

  19. La fin des certitudes ?

    OpenAIRE

    Renard, Philippe

    2008-01-01

    2006 fut l’année anniversaire des 150 ans de la naissance de l’hydrogéologie quantitative. La théorie des variables régionalisées, ou géostatistique, est beaucoup plus jeune mais a eu un impact majeur. Aujourd’hui, tout étudiant manie avec brio le krigeage que ce soit pour cartographier une contamination, un champ de transmissivité, ou le toit d’une nappe. Mais la géostatistique n’est pas seulement cela. Son intérêt majeur réside non pas dans l’interpolation des paramètres mais dans la possib...

  20. Geschichte des SIN

    CERN Document Server

    Pritzker, Andreas

    2013-01-01

    Dieses Buch erzählt die Geschichte des Schweizerischen Instituts für Nuklearforschung (SIN). Das Institut wurde 1968 gegründet und ging 1988 ins Paul Scherrer Institut (PSI) über. Die Gründung des SIN erfolgte in einer Zeit, als die Physik weitherum als Schlüsseldisziplin für die technologische und gesellschaftliche Entwicklung galt. Der Schritt war für ein kleines Land wie die Schweiz ungewöhnliche und zeugte von Mut und Weitsicht. Ungewöhnlich waren der Folge die Leistungen des SIN im weltweiten Vergleich sowie sein Einfluss auf die schweizerische, teils auf die internationale Wissenschaftspolitik.

  1. Chimie des processus biologiques

    OpenAIRE

    Fontecave, Marc

    2016-01-01

    Enseignement Cours : Du CO2 aux carburants, un renversement salutaire Le développement des nouvelles technologies de l’énergie pour l’exploitation des énergies renouvelables, comme l’énergie solaire ou l’énergie éolienne diluées et intermittentes, nécessite celui des procédés de stockage de l’énergie. Une façon de stocker ces énergies est de les transformer en énergie chimique. L’exemple le plus classique est l’électrolyse de l’eau en hydrogène, ce dernier pouvant être en effet ensuite utilis...

  2. Des millets aux nations

    OpenAIRE

    Pitsos, Nicolas

    2012-01-01

    L’auteur de ce roman construit son intrigue sur l’histoire de plusieurs familles d’une part au moment de l’effondrement d’un monde, celui des millets de l’Empire ottoman fondé sur le principe de l’identification des individus en fonction de leurs croyances religieuses et, d’autre part, lors de la mise en place d’une nouvelle organisation politique, celle des États-nations obsédés par l’idée de la définition de l’individu sur la base de critères nationaux. L'exemple narratif dominant est celui...

  3. La foi des charbonniers

    OpenAIRE

    Desbois, Evelyne; Jeanneau, Yves; Mattéi, Bruno

    2014-01-01

    Entre 1945 et 1947, deux années lourdes d'effets historiques et sociaux : la corporation minière atteint son apogée et commence son déclin. Trois regards croisés, complémentaires, portés sur un même objet, cette bataille du charbon dont on ne sait plus grand-chose, même du côté des terrils du Nord. Face au trou noir laissé dans les mémoires par cet épisode productiviste - amnésie collective remarquable - cette recherche soulève des questions iconoclastes, convoque des témoins, acteurs ou spe...

  4. Les archives des bagnes

    Directory of Open Access Journals (Sweden)

    Archives Nationales d’Outre-Mer

    2008-01-01

    Full Text Available Les établissements pénitentiaires coloniaux étaient administrés par le ministère de la Marine et des Colonies, puis par le ministère des Colonies (1881, en liaison avec les ministères de la Justice et de l’Intérieur. Les archives ont par conséquent été versées aux Archives nationales d’outre-mer avec le fonds du ministère des Colonies.Le fonds représente environ 760 ml (5358 articles. Il concerne presque exclusivement les bagnes de Guyane et de Nouvelle-Calédonie et couvre la période 1852-1...

  5. Anaerobic Biodegradability of Agricultural Renewable Fibers

    OpenAIRE

    Shi, Bo; Lortscher, Peter; Palfery, Doris

    2013-01-01

    Natural fiber-based paper and paperboard products are likely disposed of in municipal wastewater, composting, or landfill after an intended usage. However, there are few studies reporting anaerobic sludge digestion and biodegradability of agricultural fibers although the soiled sanitary products, containing agricultural fibers, are increasingly disposed of in municipal wastewater or conventional landfill treatment systems, in which one or more unit operations are anaerobic digestion. We condu...

  6. Assessment of polymer-based nanocomposites biodegradability

    OpenAIRE

    Machado, A.V.; Araújo, Andreia Isabel Silva; Oliveira, Manuel

    2015-01-01

    The management of solid waste is a growing concern in many countries. Municipal solid waste is a major component of the total solid waste generated by society, and the composting of municipal solid waste has gained some attention even though a composting treatment for it is not yet widespread. It may not be realistic to replace large portions of these plastics with biodegradable materials, and it may be more important to separate plastics unsuitable for the composting process at the generatin...

  7. Biodegradation of Petroleum Hydrocarbons in Soil

    OpenAIRE

    MR Mehrasbi; B Haghighi; M.Shariat; S Naseri; Naddafi, K

    2003-01-01

    Biodegradation of petroleum hydrocarbons (20 g/kg dw soil) was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil) are 60 %, 36 % and 55 %, respectively. Dehydrogenas...

  8. Nanomembranes and nanofibers from biodegradable conducting polymers

    OpenAIRE

    Jordi Puiggalí; Carlos Alemán; Luís Javier del Valle; Elaine Armelin; María del Mar Pérez-Madrigal; Elena Llorens

    2013-01-01

    This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e. g., aliphatic polyesters such as polylactide or polycaprolactone) and conducting polymers (e. g., polyaniline, polypirrole or polythiophenes). These materials have potential biomedical applications (e. g., tissue engineering or drug delivery systems) and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their correspon...

  9. Biodegradation of tert-butylphenyl diphenyl phosphate

    International Nuclear Information System (INIS)

    The biodegradation of tert-butylphenyl diphenyl phosphate (BPDP) was examined in microcosms containing sediment and water from five different ecosystems as part of studies to elucidate the environmental fate of phosphate ester flame retardants. Biodegradation of [14C]BPDP was monitored in the environmental microcosms by measuring the evolution of 14CO2. Over 37% of BPDP was mineralized after 8 weeks in microcosms from an ecosystem which had chronic exposure to agricultural chemicals. In contrast, only 1.7% of BPDP was degraded to 14CO2 in samples collected from a noncontaminated site. The exposure concentration of BPDP affected the percentage which was degraded to 14CO2 in microcosms from the two most active ecosystems. Mineralization was highest at a concentration of 0.1 mg of BPDP and was inhibited with 10- and 100-fold higher concentrations of BPDP. The authors observed adaptive increases in both microbial populations and phosphoesterase enzymes in some sediments acclimated to BPDP. Chemical analyses of the residues in the microcosms indicated undegraded BPDP and minor amounts of phenol, tert-butylphenol, diphenyl phosphate, and triphenyl phosphate as biodegradation products. These data suggest that the microbial degradation of BPDP results from at least three catabolic processes and is highest when low concentrations of BPDP are exposed to sediment microorganisms of eutrophic ecosystems which have high phosphotri- and diesterase activities and previous exposure to anthropogenic chemicals

  10. Nanomembranes and Nanofibers from Biodegradable Conducting Polymers

    Directory of Open Access Journals (Sweden)

    Jordi Puiggalí

    2013-09-01

    Full Text Available This review provides a current status report of the field concerning preparation of fibrous mats based on biodegradable (e.g., aliphatic polyesters such as polylactide or polycaprolactone and conducting polymers (e.g., polyaniline, polypirrole or polythiophenes. These materials have potential biomedical applications (e.g., tissue engineering or drug delivery systems and can be combined to get free-standing nanomembranes and nanofibers that retain the better properties of their corresponding individual components. Systems based on biodegradable and conducting polymers constitute nowadays one of the most promising solutions to develop advanced materials enable to cover aspects like local stimulation of desired tissue, time controlled drug release and stimulation of either the proliferation or differentiation of various cell types. The first sections of the review are focused on a general overview of conducting and biodegradable polymers most usually employed and the explanation of the most suitable techniques for preparing nanofibers and nanomembranes (i.e., electrospinning and spin coating. Following sections are organized according to the base conducting polymer (e.g., Sections 4–6 describe hybrid systems having aniline, pyrrole and thiophene units, respectively. Each one of these sections includes specific subsections dealing with applications in a nanofiber or nanomembrane form. Finally, miscellaneous systems and concluding remarks are given in the two last sections.

  11. Biodegradation of ion-exchange media

    International Nuclear Information System (INIS)

    Ion-exchange media, both bead resins and powdered filter media, are used in nuclear power plants to remove radioactivity from process water prior to reuse or environmental discharge. Since the ion- exchange media are made from synthetic hydrocarbon-based polymers, they may be susceptible to damage from biological activity. The purpose of this study was to investigate some of the more basic aspects of biodegradation of ion-exchange media, specifically to evaluate the ability of microorganisms to utilize the ion-exchange media or materials sorbed on them as a food source. The ASTM-G22 test, alone and combined with the Bartha Pramer respirometric method, failed to indicate the biodegradability of the ion-exchange media. The limitation of these methods was that they used a single test organism. In later phases of this study, a mixed microbial culture was grown from resin waste samples obtained from the BNL High Flux Beam Reactor. These microorganisms were used to evaluate the susceptibility of different types of ion-exchange media to biological attack. Qualitative assessments of biodegradability were based on visual observations of culture growths. Greater susceptibility was associated with increased turbidity in solution indicative of bacterial growth, and more luxuriant fungal mycelial growth in solution or directly on the ion-exchange resin beads. 21 refs., 9 figs., 18 tabs

  12. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    International Nuclear Information System (INIS)

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications

  13. Macmillan ring-free oil biodegradation project

    International Nuclear Information System (INIS)

    Crude oil processing at the Macmillan Ring-Free Oil Company facility (Macmillan Oil Refinery) began in approximately 1929. Operations produced naphtha, diesel fuel, insulating oil, lubricating oil, and asphalt until approximately 1987. The waste material generated by the process was Resource Conservation and Recovery Act (RCRA) listed waste K048-Dissolved Air Flotation (DAF) float containing volatile and semivolatile organic compounds. On-site unlined surface impoundments used to store DAF and crude oil wastes have periodically overflowed and contaminated two adjacent creeks. A series of extensive site investigation activities in 1992 and 1993 addressed tank and drum, asbestos, lagoon and groundwater contamination at the site. The results of the investigation indicated that the majority of the contamination is contained within 10 lagoons and surrounding soils. Volume calculations indicate that approximately 45,000 cubic yards of contaminated soils and sediments required treatment. A field simulation of biodegradation of these wastes in a land treatment unit was implemented during removal actions. Results of the remedy selection biodegradation assessment provided evidence of a 61 to 96 percent reduction in contaminant concentrations. These concentrations are below land disposal and health risk-based criteria. The technology of biodegradation meets the EPA criteria for inclusion in the potential remedies for the Macmillan Oil Refinery

  14. Biodegradation potential of photocatalyzed surfactant washwater.

    Science.gov (United States)

    Maillacheruvu, K; Buck, L; Lee, E

    2001-01-01

    Enhanced release of hydrophobic compounds from a soil matrix can be achieved by use of soil-washing or soil-flushing using various surfactants. However, the surfactants used in achieving the desorption of organic contaminants may also cause a problem in subsequent removal/disposal of these contaminants. UV radiation in the presence of TiO2 as a pre-treatment step to achieve initial (or partial) breakdown of naphthalene and Sodium Dodecyl Sulfate (SDS) using batch experiments indicated that 56% to 88% naphthalene degradation occurred within 30 minutes to one hour. Preliminary results on the estimate of the batch aerobic biodegradation potential of photocatalyzed washwater containing naphthalene and SDS suggested that SDS was the major carbon and energy source for an activated sludge enrichment culture and an enrichment culture obtained from microorganisms at a contaminated site. Continuous-flow stirred tank reactors (CSTRs) with with a solids retention time (SRT) of 4 days were not effective, but an SRT of 8 days was successful in biodegrading the naphthalene and surfactant. These results indicated that photocatalytic treatment as a pre-treatment step followed by a biodegradation step may offer potential in cleaning up surfactant washwaters containing organic contaminants. PMID:11501312

  15. Titanate nanotube coatings on biodegradable photopolymer scaffolds

    Energy Technology Data Exchange (ETDEWEB)

    Beke, S., E-mail: szabolcs.beke@iit.it [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Kőrösi, L. [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632, Pécs (Hungary); Scarpellini, A. [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Anjum, F.; Brandi, F. [Department of Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy)

    2013-05-01

    Rigid, biodegradable photopolymer scaffolds were coated with titanate nanotubes (TNTs) by using a spin-coating method. TNTs were synthesized by a hydrothermal process at 150 °C under 4.7 bar ambient pressure. The biodegradable photopolymer scaffolds were produced by mask-assisted excimer laser photocuring at 308 nm. For scaffold coating, a stable ethanolic TNT sol was prepared by a simple colloid chemical route without the use of any binding compounds or additives. Scanning electron microscopy along with elemental analysis revealed that the scaffolds were homogenously coated by TNTs. The developed TNT coating can further improve the surface geometry of fabricated scaffolds, and therefore it can further increase the cell adhesion. Highlights: ► Biodegradable scaffolds were produced by mask-assisted UV laser photocuring. ► Titanate nanotube deposition was carried out without binding compounds or additives. ► The titanate nanotube coating can further improve the surface geometry of scaffolds. ► These reproducible platforms will be of high importance for biological applications.

  16. Bildwerke des Meisters HW

    OpenAIRE

    Schellenberger, Simona

    2007-01-01

    Etwa 20 skulpturale Arbeiten des frühen 16. Jahrhunderts werden auf der Basis stilkritischer Untersuchungen dem so genannten Meister HW zugeschrieben. Die Bildwerke gruppieren sich um drei mit den Buchstaben HW monogrammierte und datierte Bildwerke: die Figur der Hl. Helena von der Hl.-Kreuz-Kapelle des Rathauses in Halle/Saale (1501/1502), das Altarretabel in der Bornaer Marienkirche (1511) und die Schöne Tür von der Franziskanerklosterkirche in Annaberg (1512). Neben zwei Arbeiten in Goslar...

  17. Fokale Therapie des Prostatakarzinoms

    Directory of Open Access Journals (Sweden)

    Roosen A

    2013-01-01

    Full Text Available Die EAU bezeichnet die fokale Therapie des Prostatakarzinoms als die therapeutische Option mit dem größten Zukunftspotenzial, auch wenn es sich dabei derzeit nicht um ein Standardverfahren handelt. Sie vermag bei Patienten mit einem niedrigmalignen, fokal begrenzten Prostatakarzinom die Lücke zu schließen zwischen potenzieller Übertherapie durch die radikalen Standardverfahren und der onkologischen Unsicherheit einer ,,Active surveillance“. Dieser Überblick gibt den derzeitigen Kenntnisstand bei der fokalen Therapie des Prostatakarzinoms wieder.

  18. Classification des rongeurs

    OpenAIRE

    Mignon, Jacques; Hardouin, Jacques

    2003-01-01

    Les lecteurs du Bulletin BEDIM semblent parfois avoir des difficultés avec la classification scientifique des animaux connus comme "rongeurs" dans le langage courant. Vu les querelles existant encore aujourd'hui dans la mise en place de cette classification, nous ne nous en étonnerons guère. La brève synthèse qui suit concerne les animaux faisant ou susceptibles de faire partie du mini-élevage. The note aims at providing the main characteristics of the principal families of rodents relevan...

  19. Biodegradability evaluation of polymers by ISO 14855-2.

    Science.gov (United States)

    Funabashi, Masahiro; Ninomiya, Fumi; Kunioka, Masao

    2009-10-01

    Biodegradabilities of polymers and their composites in a controlled compost were described. Polycaprolactone (PCL) and poly(lactic acid) (PLA) were employed as biodegradable polymers. Biodegradabilities of PCL and PLA samples in a controlled compost were measured using a Microbial Oxidative Degradation Analyzer (MODA) according to ISO 14855-2. Sample preparation method for biodegradation test according to ISO/DIS 10210 was also described. Effects of sizes and shapes of samples on biodegradability were studied. Reproducibility of biodegradation test of ISO 14855-2 by MODA was confirmed. Validity of sample preparation method for polymer pellets, polymer film, and polymer products of ISO/DIS 10210 for ISO 14855-2 was confirmed. PMID:20111676

  20. Biodegradable materials as binders for IVth generation moulding sands

    Directory of Open Access Journals (Sweden)

    K. Major-Gabry

    2015-09-01

    Full Text Available This paper focuses on the possibility of using the biodegradable materials as binders (or parts of binders?compositions for foundry moulding and core sands. Results showed that there is a great possibility of using available biodegradable materials as foundry moulding sand binders. Using biodegradable materials as partial content of new binders, or additives to moulding sands may not only decrease the toxicity and increase reclamation ability of tested moulding sands, but also accelerate the biodegradation rate of used binders, and the new biodegradable additive (PCL did not decrease the strength and thermal properties. In addition, using polycaprolactone (PCL as a biodegradable material may improve the flexibility of moulding sands with polymeric binder and reduce toxicity.

  1. Figures mythiques des mondes musulmans

    OpenAIRE

    Aigle, Denise; Arnaud, Jean-Luc; Bacqué-Grammont, Jean-Louis; Balaÿ, Christophe; Bohas, Georges; Claudot-Hawad, Hélène; Copeaux, Etienne; Deheuvels, Luc-Willy; Démians d'Archimbaud, Gabrielle; Denoix, Sylvie; DeWeese, Devin; Farès-Drappeau, Saba; Forbes Manz, Beatrice; Frank, Allen J.; Guichard, Pierre

    2004-01-01

    En rapportant des récits extraordinaires mettant en scène des ancêtres fondateurs, l'historiographie islamique remplit une fonction mythique. Dans la mémoire des peuples, l'histoire est dominée par une longue succession de figures glorieuses comme Iskandar, l'Alexandre le Grand des musulmans, le Prophète et ses Compagnons, Saladin, Baybars, Gengis Khan, Tamerlan qui fondent, défendent et rénovent au fil des siècles une tradition immémoriale. Ces grands ancêtres sont pris pour modèles, se char...

  2. Dans la Trajectoire des Choses

    OpenAIRE

    Coupaye, Ludovic; Douny, Laurence

    2010-01-01

    Dans la trajectoire des choses. Comparaison des approches francophones et anglophones contemporaines en anthropologie des techniques. Dans cette introduction, les auteurs exposent les approches francophones et anglophones de l’étude des techniques et suggèrent que ces deux traditions ont traité d’enjeux comparables. Ils les resituent dans l’histoire des Sciences humaines et analysent leur place dans le champ anthropologique. Ils retracent les débats et les échanges qui les ont enrichies, part...

  3. Degradation of Oxo-Biodegradable Plastic by Pleurotus ostreatus

    OpenAIRE

    José Maria Rodrigues da Luz; Sirlaine Albino Paes; Mateus Dias Nunes; Marliane de Cássia Soares da Silva; Maria Catarina Megumi Kasuya

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ul...

  4. Biodegradation of flax fiber reinforced poly lactic acid

    Directory of Open Access Journals (Sweden)

    2010-07-01

    Full Text Available Woven and nonwoven flax fiber reinforced poly lactic acid (PLA biocomposites were prepared with amphiphilic additives as accelerator for biodegradation. The prepared composites were buried in farmland soil for biodegradability studies. Loss in weight of the biodegraded composite samples was determined at different time intervals. The surface morphology of the biodegraded composites was studied with scanning electron microscope (SEM. Results indicated that in presence of mandelic acid, the composites showed accelerated biodegradation with 20–25% loss in weight after 50–60 days. On the other hand, in presence of dicumyl peroxide (as additive, biodegradation of the composites was relatively slow as confirmed by only 5–10% loss in weight even after 80–90 days. This was further confirmed by surface morphology of the biodegraded composites. We have attempted to show that depending on the end uses, we can add different amphiphilic additives for delayed or accelerated biodegradability. This work gives us the idea of biodegradation of materials from natural fiber reinforced PLA composites when discarded carelessly in the environment instead of proper waste disposal site.

  5. Silicon microneedles array with biodegradable tips for transdermal drug delivery

    CERN Document Server

    Chen, B; Tay, Francis; Wong, Y T; Iliescu, C

    2008-01-01

    This paper presents the fabrication process, characterization results and basic functionality of silicon microneedles array with biodegradable tips. In order to avoid the main problems related to silicon microneedles : broking of the top part of the needles inside the skin, a simple solution can be fabrication of microneedles array with biodegradable tips. The silicon microneedles array was fabricated by using reactive ion etching while the biodegradable tips were performed using and anodization process that generates selectively porous silicon only on the top part of the skin. The paper presents also the results of in vitro release of calcein using microneedles array with biodegradable tips

  6. Critical evaluation of biodegradable polymers used in nanodrugs.

    Science.gov (United States)

    Marin, Edgar; Briceño, Maria Isabel; Caballero-George, Catherina

    2013-01-01

    Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed. PMID:23990720

  7. Strawberry under low-tunnel protected with experimental biodegradable films

    International Nuclear Information System (INIS)

    A research was carried out in order to test innovative biodegradable materials for the protected cultivation of strawberry in Southern Italy. A field test was carried out in order to evaluate the agronomic performances of the biodegradable materials in comparison with non biodegradable LDPE materials. Different kinds of biodegradable black films were used for soil mulching and transparent biodegradable films for the covering of the low tunnels. Climatic data of the site, air temperature and relative humidity inside the low tunnels and soil temperature under the mulching films were gathered during the test. Besides, laboratory radiometric tests were executed on the films in order to evaluate parameters such as the transmissivity in different wavelength ranges. The biodegradable materials showed a high capacity to induce greenhouse effect due to their very low transmissivity in the long wave infrared range. The yield obtained using biodegradable materials was on average 12% higher then the one obtained with traditional films. Concerning the earliness, at the first day of the harvest, the yield obtained with biodegradable materials was 70% higher in comparison with the case of LDPE films. The research showed that the biodegradable materials could be a sustainable alternative to the plastic films based on fossil raw materials

  8. Influence of inorganic salt on aerobic biodegradability of dyestuffs

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    this paper, the influence of inorganic salt on aerobic biodegradability of dyestuffs was studied by means of semicontinuous activated sludge method. It was found that: biodegradability of dyestuffs would decrease with the increase of the concentration of NaCl; however, biodegradability in the condition of NaCl = 30 g/L was better than that in the condition of NaCl =15 g/L; in the three NaCl conditions, biodegradability of tasted dyestuffs followed the following order: NaCl= 0 g/L > NaCl= 30g/L>NaCl= 15 g/L.

  9. REPRISE DES COURS - Yoga

    CERN Document Server

    Club de Yoga

    2015-01-01

    REPRISE DES COURS – Venez nombreux ! Yoga, Sophrologie, Tai Chi La liste des cours pour le semestre allant du 1er septembre 2015 au 31 janvier 2016 est disponible sur notre site web : http://club-yoga.web.cern.ch Lieu Les cours ont lieu dans la salle des clubs, à l’entresol du restaurant No 2, Bât. 504 (dans la salle no 3 pour la Sophrologie). Prix des cours Le prix pour le semestre (environ 18 leçons) est fixé à 220 CHF plus 10 CHF d’adhésion annuelle au Club. Couple : 200 CHF par personne. 2 cours par semaine : 400 CHF. Inscriptions Les inscriptions aux cours seront prises directement auprès du professeur, lors de la 1ère séance. Avant de s’inscrire pour le semestre, il est possible d’essayer une séance gratuitement. Informations : http://club-yoga.web.cern.ch ----------------------------------------- cern.ch/club-yoga/

  10. Vom Ort des Philosophierens

    Directory of Open Access Journals (Sweden)

    Damir Barbaric

    2002-12-01

    Full Text Available Im Aufsatz wird versucht, den ursprünglichen Sinn der Platonischen Bestimmung vom Staunen als Anfang der Philosophie zu ermitteln, und zwar durch eine kritischen Abhebung von ihrer Umdeutung bei Aristoteles, und dann insbesondere in der Stoa wie auch bei Spinoza und Hegel. Dabei wird auf die frühgriechische Erfahrung vom Staunen als _______ aufmerksam gemacht, wo es vor allem die Grundstimmung des Dabeiseins des Göttlichen und der menschlichen Teilnahme am Göttlichen bedeutet. Dem entspricht die bei Platon stark hervorgehobene Rolle des “Pathetischen” am Staunen, das in der nachkommenden Tradition grundsätzlich verlorengegangen ist. Für Platon entspringt das Staunen einem nie zu überwindenden Zustand der wesentlichen philosophischen “Weglosigkeit” (_____, welche schon bei Aristoteles nur noch im Sinne eines unbedingt zu verlassenden Ausgangspunkts der methodisch sicher fortfahrenden philosophischen Wissenschaft verstanden wird. Durch ein Zurückgreifen auf die Diotimas Lehre im Dialog Symposion wird dementgegen die Sokratisch-Platonische “Weglosigkeit” als der einzig angemessene “Ort” des echten Philosophierens bestimmt, welchen es, als das “Zwischen” für das Weltspiel der Unsterblichen und Sterblichen, um jeden Preis zu bewahren und offen zu halten gilt.

  11. La physique des infinis

    CERN Document Server

    Bernardeau, Francis

    2013-01-01

    Écrire l'histoire de l'Univers, tel est l'objectif commun des physiciens des particules et des astrophysiciens. Pour y parvenir, deux approches s'épaulent : la voie de l'infiniment petit, que l'on emprunte via de gigantesques accélérateurs de particules, et celle de l'infiniment grand, dont le laboratoire est l'Univers. Un Univers qui est bien loin d'avoir livré tous ses secrets. On connaît à peine 4,8 % de la matière qui le constitue, le reste étant composé de matière noire (25,8 %) et d'énergie noire (69,4 %), toutes deux de nature inconnue. Et si la récente découverte du boson de Higgs valide le Modèle standard de la physique des particules, celui-ci est toujours incomplet et doit être étendu à ou dépassé. Est-on arrivé au bout du jeu de poupées russes de la matière ? Quelles sont les particules manquantes ? Faut-il revoir les lois fondamentales ? Quels instruments faut-il mettre en œuvre pour accéder à cette « nouvelle physique » ? Comment parler de Super Big Science aux citoye...

  12. CHAINE DES ROTISSEUR @ HILTON

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The annual gala dinner of Chaine des Rotisseurs was hosted by Hilton Beijing. The “Ballet Dinner” - a great creation for both art and fine dining lovers was taken place in varies places within the hotel, including hotel lobby, 3rd floor and lobby lounge.

  13. Etude de la desactivation des catalyseurs d'hydrotraitement par cokage. Synthèse bibliographique Study of the Deactivation of Hydrotreating Catalysts by Coking. Bibliographic Synthesis

    Directory of Open Access Journals (Sweden)

    Gualda G.

    2006-11-01

    Full Text Available Ce travail effectue la synthèse de la littérature disponible en février 1987 sur le phénomène de cokage en hydrotraitement entraînant la désactivation des catalyseurs. Il propose trois angles d'étude apportant chacun un éclairage complémentaire sur le sujet : - un angle physico-chimique qui décrit les méthodes de caractérisation du coke et des catalyseurs usés utilisées par les auteurs, et les informations qu'elles fournissent; - un angle d'observation macroscopique du phénomène de désactivation par cokage, par la confrontation de modèles et de résultats expérimentaux; - un angle plus fondamental faisant état des mécanismes proposés pour la formation du coke dans les conditions d'hydrotraitement des fractions lourdes du pétrole en particulier. Il ressort de cette étude la très grande hétérogénéité des travaux, tant du point de vue des protocoles expérimentaux que des interprétations mécanistiques. Une étude rigoureuse et systématique s'impose donc dans ce domaine. Toutefois, il semble bien établi que l'on puisse faire la différence entre un coke fatal formé par dégradation thermique des hydrocarbures, et un coke dépendant des propriétés des catalyseurs mis en oeuvre. This article makes a synthesis of the literature available in February 1987 on the coking phenomenon in hydrotreating causing catalyst deactivation. It proposes three angles of study, each giving complementary light on the subject:(a a physicochemical angle describing methods of characterizing the coke and catalysts used by the authors, and the information they provide;(b a macroscopic observation angle of the deactivation phenomenon by coking, by comparing models and experimental results;(c a more fundamental angle bearing on the mechanisms proposed for coke formation under hydrotreatment conditions of heavy oil fractions in particular. This study shows the great heterogeneity of research, from the standpoint of both experimental

  14. Thermal Evolution of Crude Oils in Sedimentary Basins: Experimental Simulation in a Confined System and Kinetic Modeling Evolution thermique des huiles dans les bassins sédimentaires : simulation expérimentale par pyrolyse en milieu confiné et modélisation cinétique

    Directory of Open Access Journals (Sweden)

    Behar F.

    2006-11-01

    coefficients alphaij were optimized with reference to a dataset comprising the final compositions resulting from oil pyrolysis experiments. This optimization was carried out successively on each distillate and each residue, on both distillate and residue from the same oil, then on the two distillates and two residues altogether. The model accounts satisfactorily for the specific kinetics of cracking of both each oil and of the two oils together, suggesting that it is now possible to predict the thermal behavior of a given oil provided the proportions of the ten fractions selected for the model are known. The wide temperature range in which the model is valid, supports its extrapolation to the temperature range of sedimentary basins. Une meilleure connaissance des mécanismes du craquage thermique des huiles doit permettre de mieux comprendre leur évolution naturelle dans les bassins sédimentaires et donc d'améliorer les modèles actuels utilisés pour prédire la formation du gaz. Bien que les mécanismes de craquage soient bien connus pour des composés modèles ou des mélanges simples d'hydrocarbures, il n'existe pas à l'heure actuelle, à l'exception des modèles empiriques, de méthode pour rendre compte de la dégradation thermique des mélanges complexes, surtout, lorsque ces derniers sont enrichis en produits lourds. Au cours du craquage thermique, une huile produira à la fois des composés plus légers et des composés plus lourds que la charge initiale. En conséquence, les produits de pyrolyse seront un mélange complexe contenant des produits nouveaux et des composés non encore dégradés. Afin de pouvoir faire la distinction entre réactifs et produits, nous avons choisi de fractionner chaque huile en deux grandes fractions : la première (distillat 300- contenant des hydrocarbures légers de C6 à C16 et la seconde (résidu 300+ contenant des hydrocarbures et des produits polaires. Afin de simuler l'évolution thermique des huiles, nous avons réalisé une

  15. Sociobiology of biodegradation and the role of predatory protozoa in biodegrading communities

    Indian Academy of Sciences (India)

    Tejashree Modak; Shalmali Pradhan; Milind Watve

    2007-06-01

    Predatory protozoa are known to enhance biodegradation by bacteria in a variety of systems including rumen. This is apparently counterintuitive since many protozoa do not themselves produce extracellular degradative enzymes and prey upon bacterial degraders. We propose a mechanism of protozoal enhancement of bacterial biodegradation based on the sociobiology of biodegradation. Since extracellular enzyme production by degraders involves a cost to the bacterial cell, cheaters that do not make the enzyme will have a selective advantage. In the presence of cheaters, degraders that physically attach to water-insoluble substrate will have a selective advantage over free-floating degraders. On the other hand, cheaters will benefit by being free floaters since they consume the solubilized products of extracellular enzymes. Predatory ciliated protozoa are more likely to consume free-floating cheaters. Thus, due to protozoan predation a control is exerted on the cheater population. We illustrate the dynamics of such a system with the help of a computer simulation model. Available data on rumen and other biodegradation systems involving protozoa are compatible with the assumptions and predictions of the model.

  16. Biodegradable and semi-biodegradable composite hydrogels as bone substitutes: morphology and mechanical characterization.

    Science.gov (United States)

    Sanginario, V; Ginebra, M P; Tanner, K E; Planell, J A; Ambrosio, L

    2006-05-01

    Biodegradable and semi-biodegradable composite hydrogels are proposed as bone substitutes. They consist of an hydrophilic biodegradable polymer (HYAFF 11) as matrix and two ceramic powders (alpha-TCP and HA) as reinforcement. Both components of these composites have been of great interest in biomedical applications due to their excellent biocompatibility and tissue interactions, however they have never been investigated as bone substitute composites. Morphological and mechanical analysis have shown that the two fillers behave in a very different way. In the HYAFF 11/alpha-TCP composite, alpha-TCP is able to hydrolyze in contact with water while in the HYAFF 11 matrix. As a result, the composite sets and hardens, and entangled CDHA crystals are formed in the hydrogel phase and increases in the mechanical properties are obtained. In the HYAFF11/HA composite the ceramic reinforcement acts as inert phase leading to lower mechanical properties. Both mechanical properties and microstructure analysis have demonstrated the possibility to design hydrophilic biodegradable composite structures for bone tissue substitution applications. PMID:16688585

  17. Migration of hydrocarbons in the subsoil of an industrial installation; Migration d'hydrocarbures dans le sous-sol d'une installation industrielle

    Energy Technology Data Exchange (ETDEWEB)

    Van Dorpe, F. [CEA Cadarache, Dept. d' Entreposage et de Stockage des Dechets (DCC/DESD/SEP), 13 - Saint-Paul-lez-Durance (France); Centre National de Recherche sur les Sites et Sols Pollues (CNRSSP), 59 - Douai (France)

    2000-07-01

    transport of PAHs under an old coke plant, taking biodegradation and soil sorption into account. The simulation results discussed in this paper were obtained by assuming tar pollution 7 m deep underground to be the only source. This aquifer pollution in a chalky formation mainly consists of PAHs (naphthalene, fluoranthene, etc). A broad field investigation was conducted on the site by monitoring the water (16 piezometers, piezometric measurements, pollutant concentration analysis) to characterize the location and extent of the PAH plume. The numerical modeling was aimed to characterize PAH migration in the unsaturated and saturated zones and to assess the vulnerability of a drinking water well located downstream. The model helped estimate the time for dissolved naphthalene to reach steady state (20 years) and the plume dimensions (1200 m long, 300 m wide and 15 m thick). Simulation were performed of water samplings in piezometers inside and outside the polluted area and the naphthalene concentration in water samples was reproduced, in good agreement with real observations on boreholes of the site. However, for two piezometers located between the two lagoons of coal tars, a large contribution of a second source of PAH, enriched in PAHs with 2 or 3 rings and located at the base of aquifer, was identified in water samples, in the pumped water. This significant share of the pollution is not transported with groundwater flow, but only with water pumping. Thus SIMUSCOPP served to identify the dissolved phase of PAH and to quantify the rest of the pollution, possibly a colloidal phase. As a consequence, a new water sampling strategy could be developed in order to adjust the pump discharge, use specific filters, etc. The major conclusion of the transport simulation is that the PAH plume does not reach the drinking water well located 4 km downstream of the site. However, some remediation measures are necessary and the polluted soils are currently being excavated. (author)

  18. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by pot experiment and It was promising to prevent pepper, Chinese cabbage and radish from anthrax, phytophthora and root rot

  19. Development of biodegradable fungicide by radiation

    International Nuclear Information System (INIS)

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Sixteen antifungal microbes were isolated and 4 antifungal activity enhanced mutants were induced by using radiation. P. lentimorbus WJ5a17 had 41% higher antifungal activity than the wild type. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified

  20. Lipase biocatalysis for useful biodegradable products

    Energy Technology Data Exchange (ETDEWEB)

    Linko, Y.Y.; Wang, Zhuo Lin; Uosukainen, E.; Seppaelae, J. [Helsinki Univ. of Technology, Espoo (Finland); Laemsae, M. [Raisio Group Oil Milling Industry, Raisio (Finland)

    1996-12-31

    It was shown that lipases can be used as biocatalysts in the production of useful biodegradable compounds such as 1-butyl oleate by direct esterification of butanol and oleic acid to decrease viscosity of biodiesel in winter use. By enzymic transesterification, a mixture of 2-ethyl-1-hexyl esters from rapeseed oil fatty acids can be obtained in good yields for use as a solvent, and of trimethylolpropane esters for use as a lubricant. Finally, it was demonstrated that polyesters with a mass average molar mass in excess of 75,000 g mol{sup -}1 can be obtained by esterification or transesterification by using lipase as biocatalyst. (author) (3 refs.)

  1. Development of biodegradable fungicide by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Youngkeun; Kim, Dongsub

    2012-03-15

    To develop the fungicide which is biodegradable and alternative to chemical pesticide that has an side effect of environmental pollution, Mutant induction of the enhanced antifungal activity was studied by using radiation. Characteristics and structure of antifungal biomaterials derived from these mutants were analysed. Two biomaterials related to the antifungal activity from the above mutant were isolated and purified. Microbial pesticide were manufactured in combination of various additives. Antiphytopathogenic effects were proven by field test and it was promising to prevent Chinese cabbage and radish from phytophthora and root rot.

  2. Biodegradation of petroleum hydrocarbons in hypersaline environments

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Martins

    2012-09-01

    Full Text Available Literature on hydrocarbon degradation in extreme hypersaline media presents studies that point to a negative effect of salinity increase on hydrocarbonoclastic activity, while several others report an opposite tendency. Based on information available in the literature, we present a discussion on the reasons that justify these contrary results. Despite the fact that microbial ability to metabolize hydrocarbons is found in extreme hypersaline media, indeed some factors are critical for the occurrence of hydrocarbon degradation in such environments. How these factors affect hydrocarbon degradation and their implications for the assessment of hydrocarbon biodegradation in hypersaline environments are presented in this review.

  3. Compared in vivo toxicity in mice of lung delivered biodegradable and non-biodegradable nanoparticles.

    Science.gov (United States)

    Aragao-Santiago, Letícia; Hillaireau, Hervé; Grabowski, Nadège; Mura, Simona; Nascimento, Thais L; Dufort, Sandrine; Coll, Jean-Luc; Tsapis, Nicolas; Fattal, Elias

    2016-04-01

    To design nanoparticle (NP)-based drug delivery systems for pulmonary administration, biodegradable materials are considered safe, but their potential toxicity is poorly explored. We here explore the lung toxicity in mice of biodegradable nanoparticles (NPs) and compare it to the toxicity of non-biodegradable ones. NP formulations of poly(d,l-lactide-co-glycolide) (PLGA) coated with chitosan (CS), poloxamer 188 (PF68) or poly(vinyl alcohol) (PVA), which renders 200 nm NPs of positive, negative or neutral surface charge respectively, were analyzed for their biodistribution by in vivo fluorescence imaging and their inflammatory potential after single lung nebulization in mice. After exposure, analysis of bronchoalveolar lavage (BAL) cell population, protein secretion and cytokine release as well as lung histology were carried out. The inflammatory response was compared to the one induced by non-biodegradable counterparts, namely, TiO2 of rutile and anatase crystal form and polystyrene (PS). PLGA NPs were mostly present in mice lungs, with little passage to other organs. An increase in neutrophil recruitment was observed in mice exposed to PS NPs 24 h after nebulization, which declined at 48 h. This result was supported by an increase in interleukin (IL)-6 and tumor necrosis factor α (TNFα) in BAL supernatant at 24 h. TiO2 anatase NPs were still present in lung cells 48 h after nebulization and induced the expression of pro-inflammatory cytokines and the recruitment of polymorphonuclear cells to BAL. In contrast, regardless of their surface charge, PLGA NPs did not induce significant changes in the inflammation markers analyzed. In conclusion, these results point out to a safe use of PLGA NPs regardless of their surface coating compared to non-biodegradable ones. PMID:26573338

  4. Des Chiffres et des Lettres : distraction, variations, habitudes

    Directory of Open Access Journals (Sweden)

    Barbara Laborde

    2011-04-01

    Full Text Available Cet article envisage une des émissions les plus anciennes du Paysage Audiovisuel Français : Des Chiffres et des Lettres. La sérialité que l’émission met en œuvre au cours de son histoire est faite de variations qui témoignent à la fois des évolutions des techniques audiovisuelles, des logiques de programmations, des attentes spectatorielles. Ce jeu télévisé, toujours le même et pourtant toujours différent, permet à la fois la reconnaissance immédiate et la perception d'un changement, double adresse qui explique sans doute sa longévité et fait de ce programme un parangon de la sérialité télévisuelle.This article considers one of the oldest programs in the French media landscape: « Des Chiffres et des Lettres ». Seriality that implements the program in its history is made changes that reflect both the evolution of audiovisual techniques, of logic programming and expectations spectatorial. This TV show, always the same and yet still different, allows both the immediate recognition and perception of a change which probably explains its longevity and made this program a paragon of seriality in television.

  5. Biodegradation of clofibric acid and identification of its metabolites

    Energy Technology Data Exchange (ETDEWEB)

    Salgado, R. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); ESTS-IPS, Escola Superior de Tecnologia de Setubal do Instituto Politecnico de Setubal, Rua Vale de Chaves, Campus do IPS, Estefanilha, 2910-761 Setubal (Portugal); Oehmen, A. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Carvalho, G. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Instituto de Biologia Experimental e Tecnologica (IBET), Av. da Republica (EAN), 2784-505 Oeiras (Portugal); Noronha, J.P. [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Reis, M.A.M., E-mail: amr@fct.unl.pt [REQUIMTE/CQFB, Chemistry Department, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal)

    2012-11-30

    Graphical abstract: Metabolites produced during clofibric acid biodegradation. Highlights: Black-Right-Pointing-Pointer Clofibric acid is biodegradable. Black-Right-Pointing-Pointer Mainly heterotrophic bacteria degraded the clofibric acid. Black-Right-Pointing-Pointer Metabolites of clofibric acid biodegradation were identified. Black-Right-Pointing-Pointer The metabolic pathway of clofibric acid biodegradation is proposed. - Abstract: Clofibric acid (CLF) is the pharmaceutically active metabolite of lipid regulators clofibrate, etofibrate and etofyllinclofibrate, and it is considered both environmentally persistent and refractory. This work studied the biotransformation of CLF in aerobic sequencing batch reactors (SBRs) with mixed microbial cultures, monitoring the efficiency of biotransformation of CLF and the production of metabolites. The maximum removal achieved was 51% biodegradation (initial CLF concentration = 2 mg L{sup -1}), where adsorption and abiotic removal mechanisms were shown to be negligible, showing that CLF is indeed biodegradable. Tests showed that the observed CLF biodegradation was mainly carried out by heterotrophic bacteria. Three main metabolites were identified, including {alpha}-hydroxyisobutyric acid, lactic acid and 4-chlorophenol. The latter is known to exhibit higher toxicity than the parent compound, but it did not accumulate in the SBRs. {alpha}-Hydroxyisobutyric acid and lactic acid accumulated for a period, where nitrite accumulation may have been responsible for inhibiting their degradation. A metabolic pathway for the biodegradation of CLF is proposed in this study.

  6. The use of biodegradable mulch films in muskmelon crop production

    Directory of Open Access Journals (Sweden)

    Artur Saraiva

    2012-10-01

    Full Text Available Due to the large amount of mulch films used in agricultural crops and to all the environmental problems related with their disposal, the biodegradable mulch films seems to be the best solution for replacing the conventional polyethylene mulches. The main goal of this work was to evaluate and compare the performance of biodegradable mulch films with the conventional polyethylene ones in muskmelon culture during two years. Beyond fruit productivity and quality, the impact of each plastic in the soil moisture and temperature were also assessed. Taking into account that there are no reported biodegradation studies realized in Portugal, it was also important to verify the biodegradability of this new mulch films under the Portuguese soil conditions. The biodegradable mulch films did not show significant differences in fruit productivity and quality. The biodegradation rate of the mulches tested was not as high as would be expected. From the overall results obtained, biodegradable mulch films appear to be a good solution for the replacement of the conventional polyethylene mulches, however the Research and Development should continue to be done ton improve their biodegradation rate.

  7. Biodegradable elastomers for biomedical applications and regenerative medicine

    NARCIS (Netherlands)

    Bat, Erhan; Zhang, Zheng; Feijen, Jan; Grijpma, Dirk W.; Poot, Andre A.

    2014-01-01

    Synthetic biodegradable polymers are of great value for the preparation of implants that are required to reside only temporarily in the body. The use of biodegradable polymers obviates the need for a second surgery to remove the implant, which is the case when a nondegradable implant is used. After

  8. Biodegradation of Phosphonomycin by Rhizobium huakuii PMY1

    OpenAIRE

    McGrath, John W.; Hammerschmidt, Friedrich; Quinn, John P.

    1998-01-01

    The biodegradation by Rhizobium huakuii PMY1 of up to 10 mM phosphonomycin as a carbon, energy, and phosphorus source with accompanying Pi release is described. This biodegradation represents a further mechanism of resistance to this antibiotic and a novel, phosphate-deregulated route for organophosphonate metabolism by Rhizobium spp.

  9. Evaluation of Artificial Intelligence Based Models for Chemical Biodegradability Prediction

    Directory of Open Access Journals (Sweden)

    Aleksandar Sabljic

    2004-12-01

    Full Text Available This study presents a review of biodegradability modeling efforts including a detailed assessment of two models developed using an artificial intelligence based methodology. Validation results for these models using an independent, quality reviewed database, demonstrate that the models perform well when compared to another commonly used biodegradability model, against the same data. The ability of models induced by an artificial intelligence methodology to accommodate complex interactions in detailed systems, and the demonstrated reliability of the approach evaluated by this study, indicate that the methodology may have application in broadening the scope of biodegradability models. Given adequate data for biodegradability of chemicals under environmental conditions, this may allow for the development of future models that include such things as surface interface impacts on biodegradability for example.

  10. Experimental studies of biodegradation of asphalt by microorganisms

    International Nuclear Information System (INIS)

    On the geological disposal system of the radioactive wastes, the activities of the microorganisms that could degrade the asphalt might be significant for the assessment of the system performance. As the main effects of the biodegradation of the asphalt, the fluctuation of leaching behavior of the nuclides included in asphalt waste has been indicated. In this study, the asphalt biodegradation test was carried out. The microorganism of which asphalt degradation ability was comparatively higher under aerobic condition and anaerobic condition was used. The asphalt biodegradation rate was calculated and it was evaluated whether the asphalt biodegradation in this system could occur. The results show that the asphalt biodegradation rate under anaerobic and high alkali condition will be 300 times lower than under aerobic and neutral pH. (author)

  11. Critical evaluation of biodegradable polymers used in nanodrugs

    Directory of Open Access Journals (Sweden)

    Marin E

    2013-08-01

    Full Text Available Edgar Marin,1–3 Maria Isabel Briceño,2 Catherina Caballero-George11Unit of Pharmacology, Center of Biodiversity and Drug Discovery, Institute of Scientific Research and High Technology Services, 2Nano Dispersions Technology, Panama, Republic of Panama; 3Department of Biotechnology, Archaria Nagarjuna University, Guntur, IndiaAbstract: Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, flexibility, and minimal side effects. Applications of these materials include creation of skin, blood vessels, cartilage scaffolds, and nanosystems for drug delivery. These biodegradable polymeric nanoparticles enhance properties such as bioavailability and stability, and provide controlled release of bioactive compounds. This review evaluates the classification, synthesis, degradation mechanisms, and biological applications of the biodegradable polymers currently being studied as drug delivery carriers. In addition, the use of nanosystems to solve current drug delivery problems are reviewed.Keywords: biodegradable polymers, nanoparticles, drug delivery, cellular uptake, biomedical applications

  12. Le territoire des tarifs

    OpenAIRE

    2014-01-01

    Société pour la défense du commerce et de l’industrie de Marseille, Rapport présenté à la séance de la Chambre syndicale du 15 novembre 1921, par M. Camille Dufay, Marseille, 1922, p. 164-168. … D’une façon générale, commerçants et industriels se plaignent de l’élévation des tarifs, qui, en fait, excède souvent exagérément la majoration légale de 140 %, et de la suppression de certaines facilités qu’ils estiment indispensables à l’essor des affaires. Ils demandent, entre autres réformes, le r...

  13. La barricade des femmes

    OpenAIRE

    Dalotel, Alain

    2016-01-01

    L’histoire de la Commune est riche en eaux-fortes. L’une d’elles nous prend littéralement à la gorge : en pleine agonie du pouvoir révolutionnaire, 120 femmes se retranchent, fusil en main, derrière une barricade, aux pieds de Montmartre, pour s’opposer à l’armée de l’Ordre. Elles sont exterminées. Cet épisode de la guerre civile de 1871 s’est imposé à la mémoire, indiscutablement. Des barricades, lors de cette bataille tragique, on en a compté par centaines. Pourquoi pas une « barricade des ...

  14. Zur Biographie des Thomas Finck

    OpenAIRE

    Graf, Klaus

    2009-01-01

    Aus der Überlieferung der Werke des Mönchs Thomas Finck ergeben sich die Jahre 1489 und 1507 als Eckdaten seiner derzeit bekannten Lebenszeugnisse. Nach Ausweis des Cgm 6940 beendete Thomas Finck, der sich als Bruder des Benediktinerordens bezeichnet, am 8. Juli 1489 im Benediktinerkloster Elchingen die Übertragung der pseudothomasischen Schrift 'De beatitudine'. Der nur in der Karlsruher Handschrift St. Georgen 84 (möglicherweise ein Konzeptautograph) überlieferten Vorrede und Datierung sein...

  15. Des Ogle's old stump

    International Nuclear Information System (INIS)

    On 17 October 1997 Sylvia Bryan of RD4 Kaitaia wrote to 'Dear Somebody-Everybody' at the Anthropology Department, University of Auckland, urging further examination of an adzed stump found by Des Ogle during planting out of the Te Aupouri forest. The authors have since sought out relevant information and present it here for the interests of our readers. (author). 7 refs., 1 fig

  16. Ontologie des Kunstwerks

    OpenAIRE

    Hubig, Christoph

    1984-01-01

    Die Ontologie beansprucht, die Wissenschaft vom Sein der Dinge oder - nimmt man die Zeitkomponente hinzu - der Ereignisse zu sein. Als eine solche philosophische Disziplin grenzt sie sich einerseits ab von den Einzelwissenschaften, die das Dasein der Dinge zu erfassen suchen, also die Dinge in ihrer jeweiligen uns zugänglichen Tatsächlichkeit; andererseits ist die Ontologie jedoch auch nicht eine Wissenschaft vom Wesen der Dinge: Wesensbestimmungen nämlich sind Bestimmungen des Seins als Geda...

  17. Plus que des engrais

    OpenAIRE

    Fuchs, Jacques G.

    2008-01-01

    COMPOSTS ET RÉSIDUS DE MÉTHANISATION Compte tenu de l'augmentation du prix des engrais minéraux, il se manifeste un intérêt croissant pour les composts et les résidus de méthanisation. En plus de leur effet nutritif, ces produits de substitution stimulent l'activité biologique dans le sol et peuvent exercer une action favorable sur le pH.

  18. Biodegradation of cresol isomers in anoxic aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Smolenski, W.J.; Suflita, J.M.

    1987-04-01

    The biodegradation of o-, m-, and p-cresol was examined in material obtained from a shallow anaerobic alluvial sand aquifer. The cresol isomers wer preferentially metabolized, with p-cresol being the most easily degraded. m-Cresol was more persistent than the para-isomer, and o-cresol persisted for over 90 days. Biodegradations of cresol isomers was favored under sulfate-reducing conditions (SRC) compared with that under methanogenic conditions (MC). Slurries that were acclimated to p-cresol metabolism transformed this substrate at 18 and 330 nmol/h per g (dry weight) for MC and SRC, respectively. Inhibition of electron flow to sulfate reduction with 2.0 mM molybdate reduced p-cresol metabolism in incubations containing sulfate. When methanogenesis was blocked with 5 mM bromoethanesulfonic acid in incubations lacking sulfate, p-cresol catabolism was retarded. Under SRC 3.4 mol of sulfate was consumed per mol of p-cresol metabolized. The addition of sulfate to methanogenic incubations stimulated p-cresol degradation. Simultaneous adaptation studies in combination with spectrophotometric and chromatographic analysis of metabolites indicated that p-cresol was oxidized under SRC to p-hydroxybenzoate via the corresponding alcohol and aldehyde. This series of reactions was inhibited under sulfate-limited or aerobic conditions. Therefore, the primary catabolic event for p-cresol decomposition under SRC appears to involve the hydroxylation of the aryl methyl group.

  19. Optimization of low ring polycylic aromatic biodegradation

    Science.gov (United States)

    Othman, N.; Abdul-Talib, S.; Tay, C. C.

    2016-07-01

    Polycyclic aromatic hydrocarbons (PAHs) are recalcitrance and persistence that finally turn into problematic environmental contaminants. Microbial degradation is considered to be the primary mechanism of PAHs removal from the environment due to its organic criteria. This study is carried out to optimize degradation process of low ring PAHs. Bacteria used in this study was isolated from sludge collected from Kolej Mawar, Universiti Teknologi MARA, Shah Alam, Selangor. Working condition namely, substrate concentration, bacteria concentration, pH and temperature were optimized. PAHs in the liquid sample was extracted by using solid phase microextractio equipped with a 7 µm polydimethylsiloxane (PDMS) SPME fibr. Removal of PAHs were assessed by measuring PAHs concentration using GC-FID. Results from the optimization study of biodegradation indicated that maximum rate of PAHs removal occurred at 100 mgL-1 of PAHs, 10% bacteria concentration, pH 7.0 and 30°C. These working condition had proved the effectiveness of using bacteria in biodegradation process of PAHs.

  20. Monitoring Biodegradation of Magnesium Implants with Sensors

    Science.gov (United States)

    Zhao, Daoli; Wang, Tingting; Guo, Xuefei; Kuhlmann, Julia; Doepke, Amos; Dong, Zhongyun; Shanov, Vesselin N.; Heineman, William R.

    2016-04-01

    Magnesium and its alloys exhibit properties such as high strength, light weight, and in vivo corrosion that make them promising candidates for the development of biodegradable metallic implant materials for bone repair, stents and other medical applications. Sensors have been used to monitor the corrosion of magnesium and its alloys by measuring the concentrations of the following corrosion products: magnesium ions, hydroxyl ions and hydrogen gas. The corrosion characterization system with home-made capillary pH and Mg2+ microsensors has been developed for real-time detection of magnesium corrosion in vitro. A hydrogen gas sensor was used to monitor the corrosion of magnesium by measuring the concentration of the hydrogen gas reaction product in vivo. The high permeability of hydrogen through skin allows transdermal monitoring of the biodegradation of a magnesium alloy implanted beneath the skin by detecting hydrogen gas at the skin surface. The sensor was used to map hydrogen concentration in the vicinity of an implanted magnesium alloy.

  1. Immunological Response to Biodegradable Magnesium Implants

    Science.gov (United States)

    Pichler, Karin; Fischerauer, Stefan; Ferlic, Peter; Martinelli, Elisabeth; Brezinsek, Hans-Peter; Uggowitzer, Peter J.; Löffler, Jörg F.; Weinberg, Annelie-Martina

    2014-04-01

    The use of biodegradable magnesium implants in pediatric trauma surgery would render surgical interventions for implant removal after tissue healing unnecessary, thereby preventing stress to the children and reducing therapy costs. In this study, we report on the immunological response to biodegradable magnesium implants—as an important aspect in evaluating biocompatibility—tested in a growing rat model. The focus of this study was to investigate the response of the innate immune system to either fast or slow degrading magnesium pins, which were implanted into the femoral bones of 5-week-old rats. The main alloying element of the fast-degrading alloy (ZX50) was Zn, while it was Y in the slow-degrading implant (WZ21). Our results demonstrate that degrading magnesium implants beneficially influence the immune system, especially in the first postoperative weeks but also during tissue healing and early bone remodeling. However, rodents with WZ21 pins showed a slightly decreased phagocytic ability during bone remodeling when the degradation rate reached its maximum. This may be due to the high release rate of the rare earth-element yttrium, which is potentially toxic. From our results we conclude that magnesium implants have a beneficial effect on the innate immune system but that there are some concerns regarding the use of yttrium-alloyed magnesium implants, especially in pediatric patients.

  2. Modification of Biodegradable Polyesters Using Electron Beam

    International Nuclear Information System (INIS)

    Poly(4-Hydroxybutyrate) P4HB, Poly(butylene succinate-co-adipate) PBSA and Poly(ε-caprolactone) PCL were electron beam (EB)-irradiated. Poly(4-Hydroxybutyrate) was irradiated without any polyfunctional monomers (PFM). While PBSA and PCL were irradiated in the presence of polyfunctional monomers such as Trimethallyl isocyanurate (TMAIC), Polyethyleneglycol dimethacrylate (2G, 4G), Trimethylolpropane trimethacrylate (TMPT) and Tetramethylolmethane tetraacrylate (A-TMMT) at ambient temperature. Aim of the study is to improve the properties of biodegradable polyester. It was pointed out that crosslinking yield of P4HB (6.39% gel) was formed at dose of 90 kGy irradiated in vacuum conditions. Radiation degradation promoted, when P4HB was irradiated in air. The optimum crosslinking yield of PCL and PBSA respectively, were formed in the presence of 1% TMAIC at dose of 50 kGy. The biodegradability of the crosslinked PBSA evaluated by soil burial test is slightly retarded by increasing crosslinking yields. (author)

  3. A REVIEW ON BIODEGRADABLE STARCH BASED FILM

    Directory of Open Access Journals (Sweden)

    Hooman Molavi

    2015-04-01

    Full Text Available In recent years, biodegradable edible films have become very important in research related to food, due to their compatibility with the environment and their use in the food packaging industry. Various sources can be used in the production of biopolymers as biodegradable films that include polysaccharides, proteins and lipids. Among the various polysaccharides, starch due to its low price and its abundance in nature is of significant importance. Several factors affect the properties of starch films; such as the source which starch is obtained from, as well as the ratio of constituents of the starch. Starch films have advantages such as low thickness, flexibility and transparency though; there are some downsides to mention, such as the poor mechanical properties and water vapor permeability. Thus, using starch alone to produce the film will led to restrictions on its use. To improve the mechanical properties of starch films and also increases resistance against humidity, several methods can be used; including the starch modifying techniques such as cross linking of starch and combining starch with other natural polymers. Other methods such as the use of lipid in formulations of films to increase the resistance to moisture are possible, but lipids are susceptible to oxidation. Therefore, new approaches are based on the integration of different biopolymers in food packaging.

  4. A la recherche des hybrides

    OpenAIRE

    DUPONT, Ariane

    2013-01-01

    Mon programme de recherche se développe autour de deux axes : 1/ l’analyse de la demande de transport des voyageurs et de ses impacts environnementaux pour permettre la définition et l’évaluation des politiques de transport durable, et 2/ une analyse des méthodes et des outils économétriques, notamment ceux définis et développés par Ragnar Frisch. Ces deux champs semblent si disjoints que l’on pourrait croire à une schizophrénie développée suite à un basculement de parcou...

  5. Dictionnaire des risques psychosociaux

    CERN Document Server

    Zawieja, Philippe

    2014-01-01

    Stress, suicide, harcèlement, épuisement professionnel, workaholism... Au-delà de la souffrance qu'elles désignent, ces notions souvent récentes constituent une approche inédite, et demandent à mieux être comprises, dans leur ensemble et isolément. C'est tout l'enjeu de ce dictionnaire, pionnier en son genre. Le lecteur y trouvera représentés, avec les 314 entrées (rédigées par 251 contributeurs) qui le composent, tous les champs disciplinaires s'intéressant à la souffrance au travail : psychologie du travail et des organisations, psychologie sociale et psychosociologie, psychanalyse, psychopathologie et psychiatrie, ergonomie, sociologie du travail et des organisations, médecine du travail, droit du travail et de la sécurité sociale, sciences de gestion, philosophie... Y sont détaillés les principaux concepts, notions, approches, méthodes, théories, outils, études, etc., ayant cours dans l'étude des risques psychosociaux, mais aussi certaines professions emblématiques (infirmières,...

  6. Micro-seismicity induced by hydrocarbon production: contribution to localization of events and identification of the source mechanisms through the use of dynamic friction models; Contribution a la localisation des evenements et l'identification des mecanismes au foyer en micro-sismicite induite par l'exploitation d'hydrocarbures. Utilisation des modeles de frottement dynamique

    Energy Technology Data Exchange (ETDEWEB)

    Mohammedi, H.

    2002-11-01

    Oil production or any injection of fluid in a geological medium is likely to impose variations of stresses which might generate micro-seismicity. We examine whether the use of dynamic friction models could allow for a better determination of mechanics on the fault plane from borehole seismometers. We sought to identify the friction law model from seismogram observation. Before dealing with this inverse problem, we examined the direct problem generating synthetic seismograms at virtual stations, on the basis of a postulated friction law using the FD3D earthquake simulation code and the AXITRA radiation computation code. Treatment of two different laws, one of which is an original variation of the Dietrich-Ruina law, leads to similar seismograms. This might indicate that systematic inversion for the friction law only from seismogram observation might reveal difficult. (authors)

  7. Die Klassifizierung des Blutdrucks

    Directory of Open Access Journals (Sweden)

    Skrabal F

    2004-01-01

    Full Text Available Während der systolische Blutdruck in der Bevölkerung mit zunehmendem Lebensalter in jedem Dezennium weiter ansteigt, beginnt der diastolische Blutdruck ab dem 50. Lebensjahr für jede systolische Blutdruckstratifizierung als Ausdruck einer zunehmenden Gefäßschädigung wieder zu sinken. Deswegen muß der Blutdruck ausschließlich nach dem systolischen Blutdruck klassifiziert werden. Die Häufigkeitsverteilung des systolischen und diastolischen Blutdrucks innerhalb der Bevölkerung entspricht einer Gauss'schen Glockenkurve. Jede Unterteilung in normotensiv und hypertensiv entspricht deshalb einer völlig willkürlichen Dichotomisierung. Je niedriger der Blutdruck, desto geringer die mechanische Belastung der Blutgefäße und desto geringer auch die mechanisch induzierten Gefäßschäden. Das war der Grund für die zuletzt vom "7th JNC on Prevention, Detection and Treatment of Hypertension" des NIH, USA, vorgenommene Klassifizierung des Blutdrucks in normal (kleiner als 120 mmHg systolisch, prähypertensiv (120-140 mmHg und Hypertonie-Stadium I (140-160 mmHg systolisch und Hypertonie-Stadium II ( 160 mmHg systolisch. Damit muß leider die nahezu gesamte gesunde österreichische Bevölkerung, die nach bisheriger Klassifikation noch keinen Hochdruck aufweist, als prähypertensiv klassifiziert werden. Ein wirklicher Informationsgewinn (der ja mit der Klassifikation bezweckt wird ist meiner Meinung nach damit nicht mehr gegeben. Die Österreichische Hochdruckliga schlägt eine zusätzliche Klassifikation des Blutdrucks nach dem „Pressure Load“ vor, welches aus einer statistisch aussagekräftigen Zahl von Selbstmessungen leicht zu errechnen ist. Jedes Pressure Load von mehr als 20 % (mehr als 20 % der selbst gemessenen Blutdruckwerte 135/85 mmHg entspricht einer Hypertonie, die je nach Höhe der Blutdruckwerte entweder mit Änderungen des Lebensstils oder mit antihypertensiver Medikation zu bekämpfen ist.

  8. Des insectes et des hommes (Nord du Cameroun)

    OpenAIRE

    Seignobos, Christian

    2015-01-01

    Cet article est le prolongement de celui publié par le JATBA 38 de 1996 : « Les Mofu et leurs insectes », de C. Seignobos, J.-Ph. Deguine et P.H. Aberlenc. Il répond à une interrogation : la focalisation de la société mofu sur son entomofaune se retrouve-t-elle chez ses voisines des monts Mandara ? Et qu’en est-il du regard sur les insectes des populations des plaines ?Le biais des insectes dans l’étude des sociétés est toujours révélateur de leur histoire et de leur organisation sociale et p...

  9. Pyramide des âges et gestion des ressources humaines

    OpenAIRE

    Godelier, Eric

    2007-01-01

    L'utilisation de la pyramide des âges dans les discours des directeurs de ressources humaines s'est développée au cours des années 1980. Elle renvoie au choix d'un critère de sélection de salariés jugés en sureffectif. Derrière l'âge et ses représentations, c'est bien la question de la capacité des salariés à s'adapter au changement de l'entreprise qui est posée. En définitive, il s'agit de savoir s'il existe des conditions démographiques au changement organisationnel.

  10. Biodegradation of hydrocarbon cuts used for diesel oil formulation

    Energy Technology Data Exchange (ETDEWEB)

    Penet, S.; Marchal, R.; Monot, F. [Departement de Biotechnologie et Chimie de la Biomasse, Institut Francais de Petrole, Rueil-Malmaison (France); Sghir, A. [Genoscope, CNRS UMR 8030, Structure et Evolution des Genomes, Evry (France)

    2004-11-01

    The biodegradability of various types of diesel oil (DO), such as straight-run DO, light-cycle DO, hydrocracking DO, Fischer-Tropsch DO and commercial DO, was investigated in biodegradation tests performed in closed-batch systems using two microflorae. The first microflora was an activated sludge from an urban wastewater treatment plant as commonly used in biodegradability tests of commercial products and the second was a microflora from a hydrocarbon-polluted soil with possible specific capacities for hydrocarbon degradation. Kinetics of CO{sub 2} production and extent of DO biodegradation were obtained by chromatographic procedures. Under optimised conditions, the polluted-soil microflora was found to extensively degrade all the DO types tested, the degradation efficiencies being higher than 88%. For all the DOs tested, the biodegradation capacities of the soil microflora were significantly higher than those of the activated sludge. Using both microflora, the extent of biodegradation was highly dependent upon the type of DO used, especially its hydrocarbon composition. Linear alkanes were completely degraded in each test, whereas identifiable branched alkanes such as farnesane, pristane or phytane were degraded to variable extents. Among the aromatics, substituted mono-aromatics were also variably biodegraded. (orig.)

  11. [Biodegradation Coefficients of Typical Pollutants in the Plain Rivers Network].

    Science.gov (United States)

    Feng, Shuai; Li, Xu-yongl; Deng, Jian-cai

    2016-05-15

    Biodegradation is a significant part of pollutant integrated degradation, the process rate of which is represented by the biodegradation coefficient. To investigate the biodegradation law of typical pollutants in the plain rivers network located in the upstream of the Lake Taihu, experiments were conducted in site in September 2015, one order kinetics model was used to measure the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus, and influencing factors of the biodegradation coefficients were also analyzed. The results showed that the biodegradation coefficients for permanganate index, ammonia, total nitrogen and total phosphorus were 0.008 3-0.126 4 d⁻¹, 0.002 1-0.213 8 d⁻¹, 0.002 1-0.090 5 d⁻¹ and 0.011 0- 0.152 8 d⁻¹, respectively. The influencing factors of the biodegradation coefficients for permanganate index were permanganate index and pH; those for ammonia were ammonia concentration and pH; those for total nitrogen were inorganic nitrogen concentration, total dissolved solid concentration and nitrite concentration; and those for total phosphorus were background concentration and pH. The research results were of important guiding significance for pollutants removal and ecological restoration of the plain rivers network located in the unstream of the Lake Taihu. PMID:27506025

  12. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Directory of Open Access Journals (Sweden)

    José Maria Rodrigues da Luz

    Full Text Available Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate.

  13. Degradation of oxo-biodegradable plastic by Pleurotus ostreatus.

    Science.gov (United States)

    da Luz, José Maria Rodrigues; Paes, Sirlaine Albino; Nunes, Mateus Dias; da Silva, Marliane de Cássia Soares; Kasuya, Maria Catarina Megumi

    2013-01-01

    Growing concerns regarding the impact of the accumulation of plastic waste over several decades on the environmental have led to the development of biodegradable plastic. These plastics can be degraded by microorganisms and absorbed by the environment and are therefore gaining public support as a possible alternative to petroleum-derived plastics. Among the developed biodegradable plastics, oxo-biodegradable polymers have been used to produce plastic bags. Exposure of this waste plastic to ultraviolet light (UV) or heat can lead to breakage of the polymer chains in the plastic, and the resulting compounds are easily degraded by microorganisms. However, few studies have characterized the microbial degradation of oxo-biodegradable plastics. In this study, we tested the capability of Pleurotus ostreatus to degrade oxo-biodegradable (D2W) plastic without prior physical treatment, such as exposure to UV or thermal heating. After 45 d of incubation in substrate-containing plastic bags, the oxo-biodegradable plastic, which is commonly used in supermarkets, developed cracks and small holes in the plastic surface as a result of the formation of hydroxyl groups and carbon-oxygen bonds. These alterations may be due to laccase activity. Furthermore, we observed the degradation of the dye found in these bags as well as mushroom formation. Thus, P. ostreatus degrades oxo-biodegradable plastics and produces mushrooms using this plastic as substrate. PMID:23967057

  14. Digitalisierung des Kulturellen Erbes (Europas)

    OpenAIRE

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland. (http://www.slideshare.net/em3rg3/digitalisierung-des-kulturellen-erbes-europa)

  15. Digitalisierung des Kulturellen Erbes (Europas)

    NARCIS (Netherlands)

    Gruber, Marion

    2011-01-01

    Gruber, M. R. (2011, 13 December). Digitalisierung des Kulturellen Erbes (Europas). Guest lecture at the IPMZ - Institute of Mass Communication and Media Research, Devision Media Change & Innovation, University of Zurich, Switzerland. (http://www.slideshare.net/em3rg3/digitalisierung-des-kulturelle

  16. Biodegradability enhancement of textile wastewater by electron beam irradiation

    Science.gov (United States)

    Kim, Tak-Hyun; Lee, Jae-Kwang; Lee, Myun-Joo

    2007-06-01

    Textile wastewater generally contains various pollutants, which can cause problems during biological treatment. Electron beam radiation technology was applied to enhance the biodegradability of textile wastewater for an activated sludge process. The biodegradability (BOD 5/COD) increased at a 1.0 kGy dose. The biorefractory organic compounds were converted into more easily biodegradable compounds such as organic acids having lower molecular weights. In spite of the short hydraulic retention time (HRT) of the activated sludge process, not only high organic removal efficiencies, but also high microbial activities were achieved. In conclusion, textile wastewater was effectively treated by the combined process of electron beam radiation and an activated sludge process.

  17. "Rational" management of dichlorophenols biodegradation by the microalga Scenedesmus obliquus.

    Directory of Open Access Journals (Sweden)

    Aikaterini Papazi

    Full Text Available The microalga Scenedesmus obliquus exhibited the ability to biodegrade dichlorophenols (dcps under specific autotrophic and mixotrophic conditions. According to their biodegradability, the dichlorophenols used can be separated into three distinct groups. Group I (2,4-dcp and 2,6 dcp - no meta-substitution consisted of quite easily degraded dichlorophenols, since both chloride substituents are in less energetically demanding positions. Group II (2,3-dcp, 2,5-dcp and 3,4-dcp - one meta-chloride was less susceptible to biodegradation, since one of the two substituents, the meta one, required higher energy for C-Cl-bond cleavage. Group III (3,5-dcp - two meta-chlorides could not be biodegraded, since both chlorides possessed the most energy demanding positions. In general, when the dcp-toxicity exceeded a certain threshold, the microalga increased the energy offered for biodegradation and decreased the energy invested for biomass production. As a result, the biodegradation per cell volume of group II (higher toxicity was higher, than group I (lower toxicity and the biodegradation of dichlorophenols (higher toxicity was higher than the corresponding monochlorophenols (lower toxicity. The participation of the photosynthetic apparatus and the respiratory mechanism of microalga to biodegrade the group I and the group II, highlighted different bioenergetic strategies for optimal management of the balance between dcp-toxicity, dcp-biodegradability and culture growth. Additionally, we took into consideration the possibility that the intermediates of each dcp-biodegradation pathway could influence differently the whole biodegradation procedures. For this reason, we tested all possible combinations of phenolic intermediates to check cometabolic interactions. The present contribution bring out the possibility of microalgae to operate as "smart" bioenergetic "machines", that have the ability to continuously "calculate" the energy reserves and "use" the most

  18. Biodegradable Polyphosphazene Based Peptide-Polymer Hybrids

    Directory of Open Access Journals (Sweden)

    Anne Linhardt

    2016-04-01

    Full Text Available A novel series of peptide based hybrid polymers designed to undergo enzymatic degradation is presented, via macrosubstitution of a polyphosphazene backbone with the tetrapeptide Gly-Phe-Leu-Gly. Further co-substitution of the hybrid polymers with hydrophilic polyalkylene oxide Jeffamine M-1000 leads to water soluble and biodegradable hybrid polymers. Detailed degradation studies, via 31P NMR spectroscopy, dynamic light scattering and field flow fractionation show the polymers degrade via a combination of enzymatic, as well as hydrolytic pathways. The peptide sequence was chosen due to its known property to undergo lysosomal degradation; hence, these degradable, water soluble polymers could be of significant interest for the use as polymer therapeutics. In this context, we investigated conjugation of the immune response modifier imiquimod to the polymers via the tetrapeptide and report the self-assembly behavior of the conjugate, as well as its enzymatically triggered drug release behavior.

  19. Purified terephthalic acid wastewater biodegradation and toxicity

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xu-xiang; LUO Xiang; GU Ji-dong; WAN Yu-qiu; CHENG Shu-pei; SUN Shi-lei; ZHU Cheng-jun; LI Wei-xin; ZHANG Xiao-chun; WANG Gui-lin; LU Jian-hua

    2005-01-01

    The biodegradation and toxicity of the purified terephthalic acid(PTA) processing wastewater was researched at NJYZ pilot with the fusant strain Fhhh in the carrier activated sludge process(CASP). Sludge loading rate(SLR) for Fhhh to COD of the wastewater was 1.09 d-1 and to PTA in the wastewater was 0.29 d-1. The results of bioassay at the pilot and calculation with software Ebis3 showed that the 48h-LC50 (median lethal concentration) to Daphnia magna for the PTA concentration in the wastewater was only 1/10 of that for the chemical PTA. There were 5 kinds of benzoate pollutants and their toxicities existing in the wastewater at least. The toxicity parameter value of the pure chemical PTA cannot be used to predicate the PTA wastewater toxicity. The toxicity of the NJYZ PTA wastewater will be discussed in detail in this paper.

  20. Biodegradation of lignin by Agaricus Bisporus

    Energy Technology Data Exchange (ETDEWEB)

    Vane, C.H.; Abbott, G.D.; Head, I.M. [Univ. of Newcastle upon Tyne (United Kingdom)

    1996-12-31

    The lignolytic activity of Agaricus bisporus will be addressed in this paper. Sound and fungally degraded lignins were characterized by Pyrolysis-Gas Chromatography-Mass Spectrometry (Py-GC-MS), Fourier Transform Infrared Spectroscopy (FnR) and elemental analysis. Fungally degraded lignins displayed increased wt%N, wt%H and wt%O content and decreased wt%C content The FTIR spectrum of decayed lignin showed an increase in the relative intensity of absorption bands assigned to carbonyl and carboxyl functional groups located on the aliphatic side chain and a decrease in absorption bands assigned to aromatic skeletal vibration modes. Semiquantitative Py-GC-MS revealed an 82% decrease in lignin derived pyrolysis products upon biodegradation. No significant increase in pyrolysis products with an oxygenated aliphatic side chain were detected in the fungally degraded lignin however shortening of the aliphatic side chain via cleavage at the {alpha}, {beta} and {gamma} positions was observed.

  1. Lignin biodegradation with laccase-mediator systems

    Directory of Open Access Journals (Sweden)

    Lew Paul Christopher

    2014-03-01

    Full Text Available Lignin has a significant and largely unrealized potential as a source for the sustainable production of fuels and bulk high-value chemicals. It can replace fossil-based oil as a renewable feedstock that would bring about socio-economic and environmental benefits in our transition to a biobased economy. The efficient utilization of lignin however requires its depolymerization to low molecular weight phenolics and aromatics that can then serve as the building blocks for chemical syntheses of high-value products. The ability of laccase to attack and degrade lignin in conjunction with laccase mediators is currently viewed as one of the potential breakthrough applications for lignin valorization. Here we review the recent progress in lignin biodegradation with laccase-mediator systems, and research needs that need to be addressed in this field.

  2. Biodegradation and flushing of MBT wastes.

    Science.gov (United States)

    Siddiqui, A A; Richards, D J; Powrie, W

    2013-11-01

    Mechanical-biological treatment (MBT) processes are increasingly being adopted as a means of diverting biodegradable municipal waste (BMW) from landfill, for example to comply with the EU Landfill Directive. However, there is considerable uncertainty concerning the residual pollution potential of such wastes. This paper presents the results of laboratory experiments on two different MBT waste residues, carried out to investigate the remaining potential for the generation of greenhouse gases and the flushing of contaminants from these materials when landfilled. The potential for gas generation was found to be between 8% and 20% of that for raw MSW. Pretreatment of the waste reduced the potential for the release of organic carbon, ammoniacal nitrogen, and heavy metal contents into the leachate; and reduced the residual carbon remaining in the waste after final degradation from ∼320g/kg dry matter for raw MSW to between 183 and 195g/kg dry matter for the MBT wastes. PMID:23973052

  3. Biodegradation of Petroleum Hydrocarbons in Soil

    Directory of Open Access Journals (Sweden)

    MR Mehrasbi

    2003-09-01

    Full Text Available Biodegradation of petroleum hydrocarbons (20 g/kg dw soil was investigated in 3 media, differing in the kind of petroleum fractions. In the laboratory experiments, during 5 months, the activities of petroleum hydrocarbon-degrading microorganisms and dehydrogenase activity of soil was determined. Gas chromatographic analysis showed the biological decontaminations for gas oil, kerosene and synthetic mixture (gas oil, kerosene and furnace oil are 60 %, 36 % and 55 %, respectively. Dehydrogenase activity which was assessed by TTC technique, correlated significantly positive with the numbers of microorganisms. The Spearman rank correlation coefficients(r in contaminated soils with gas oil, kerosene and synthetic mixture were 0.79, 0.80 and 0.69, respectively.

  4. Gas foamed open porous biodegradable polymeric microspheres.

    Science.gov (United States)

    Kim, Taek Kyoung; Yoon, Jun Jin; Lee, Doo Sung; Park, Tae Gwan

    2006-01-01

    Highly open porous biodegradable polymeric microspheres were fabricated for use as injectable scaffold microcarriers for cell delivery. A modified water-in-oil-in-water (W1/O/W2) double emulsion solvent evaporation method was employed for producing the microspheres. The incorporation of an effervescent salt, ammonium bicarbonate, in the primary W1 droplets spontaneously produced carbon dioxide and ammonia gas bubbles during the solvent evaporation process, which not only stabilized the primary emulsion, but also created well inter-connected pores in the resultant microspheres. The porous microspheres fabricated under various gas foaming conditions were characterized. The surface pores became as large as 20 microm in diameter with increasing the concentration of ammonium bicarbonate, being sufficient enough for cell infiltration and seeding. These porous scaffold microspheres could be potentially utilized for cultivating cells in a suspension manner and for delivering the seeded cells to the tissue defect site in an injectable manner. PMID:16023197

  5. Biodegradation of polyester. Polyester no bunkai sei

    Energy Technology Data Exchange (ETDEWEB)

    Tokiwa, Y. (Agency of Industrial Science and Technology, Tokyo (Japan). Fermentation Research Inst.)

    1991-09-10

    Penicillium sp. 14-3 and penicillium sp. 26-1 can degrade various kinds of polyester. The results of studies made on hydrolysis of polyester by enzyme, hydrolysis of polyester by various kinds of lipase, and degradation of ester type polyurethane by microbes and lipase are introduced. For the improvement of physical properties of aliphatic polyester, aromatic-aliphatic polyester copolymers (CPE) have been synthesized to study the biodegradability. Copolymer in which a number of polyamide (nylon) are alternately introduced (CPAE) to aliphatic polyester has been developed. The result of studies made on the degradability of a blended body of PCL and natural high polymer, and on the collapsibility by lipase of high polymer materials including aliphatic polyamide are introduced. 26 refs., 5 figs., 1 tab.

  6. Biodegradation of concrete intended for their decontamination

    International Nuclear Information System (INIS)

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  7. Mécanique des fluides

    CERN Document Server

    Cengel, Y A

    2016-01-01

    La mécanique des fluides est un outil performant qui permet d'expliquer les phénomènes qui nous entourent de l'échelle microscopique à l'échelle macroscopique. Elle est aussi à la base du développement de nombreuses technologies. Cet ouvrage à destination des étudiants donne une vision complète de la mécanique des fluides. Bien que la mécanique des fluides puisse souvent paraître rébarbative aux yeux des étudiants, cet ouvrage valorise ce domaine d'enseignement en l'illustrant de nombreux exemples issus de l'ingénierie navale, l'aéronautique, la météorologie, etc.

  8. Antibacterial biodegradable Mg-Ag alloys

    Directory of Open Access Journals (Sweden)

    D Tie

    2013-06-01

    Full Text Available The use of magnesium alloys as degradable metals for biomedical applications is a topic of ongoing research and the demand for multifunctional materials is increasing. Hence, binary Mg-Ag alloys were designed as implant materials to combine the favourable properties of magnesium with the well-known antibacterial property of silver. In this study, three Mg-Ag alloys, Mg2Ag, Mg4Ag and Mg6Ag that contain 1.87 %, 3.82 % and 6.00 % silver by weight, respectively, were cast and processed with solution (T4 and aging (T6 heat treatment.The metallurgical analysis and phase identification showed that all alloys contained Mg4Ag as the dominant β phase. After heat treatment, the mechanical properties of all Mg-Ag alloys were significantly improved and the corrosion rate was also significantly reduced, due to presence of silver. Mg(OH2 and MgO present the main magnesium corrosion products, while AgCl was found as the corresponding primary silver corrosion product. Immersion tests, under cell culture conditions, demonstrated that the silver content did not significantly shift the pH and magnesium ion release. In vitro tests, with both primary osteoblasts and cell lines (MG63, RAW 264.7, revealed that Mg-Ag alloys show negligible cytotoxicity and sound cytocompatibility. Antibacterial assays, performed in a dynamic bioreactor system, proved that the alloys reduce the viability of two common pathogenic bacteria, Staphylococcus aureus (DSMZ 20231 and Staphylococcus epidermidis (DSMZ 3269, and the results showed that the killing rate of the alloys against tested bacteria exceeded 90%. In summary, biodegradable Mg-Ag alloys are cytocompatible materials with adjustable mechanical and corrosion properties and show promising antibacterial activity, which indicates their potential as antibacterial biodegradable implant materials.

  9. Biodegradation of crystal violet by Agrobacterium radiobacter.

    Science.gov (United States)

    Parshetti, G K; Parshetti, S G; Telke, A A; Kalyani, D C; Doong, R A; Govindwar, S P

    2011-01-01

    Agrobacterium radiobacter MTCC 8161 completely decolorized the Crystal Violet with 8 hr (10 mg/L) at static anoxic conditions. The decreased decolorization capability by A. radiobacter was observed, when the Crystal Violet concentration was increased from 10 to 100 mg/L. Semi-synthetic medium containing 1% yeast extract and 0.1% NH4C1 has shown 100% decolorization of Crystal Violet within 5 hr. A complete degradation of Crystal Violet by A. radiobacter was observed up to 7 cycles of repeated addition (10 mg/L). When the effect of increasing inoculum concentration on decolorization of Crystal Violet (100 mg/L) was studied, maximum decolorization was observed with 15% inoculum concentration. A significant increase in the activities of laccase (184%) and aminopyrine N-demethylase (300%) in cells obtained after decolorization indicated the involvement of these enzymes in decolorization process. The intermediates formed during the degradation of Crystal Violet were analyzed by gas chromatography and mass spectroscopy (GC/MS). It was detected the presence of N,N,N',N"-tetramethylpararosaniline, [N, N-dimethylaminophenyl] [N-methylaminophenyl] benzophenone, N, N-dimethylaminobenzaldehyde, 4-methyl amino phenol and phenol. We proposed the hypothetical metabolic pathway of Crystal Violet biodegradation by A. radiobacter. Phytotoxicity and microbial toxicity study showed that Crystal Violet biodegradation metabolites were less toxic to bacteria (A. radiobacter, P. aurugenosa and A. vinelandii) contributing to soil fertility and for four kinds of plants (Sorghum bicolor Vigna radiata, Lens culinaris and Triticum aestivum) which are most sensitive, fast growing and commonly used in Indian agriculture. PMID:22128547

  10. Peptide biomarkers as evidence of perchlorate biodegradation.

    Science.gov (United States)

    Bansal, Reema; Crawford, Ronald L; Paszczynski, Andrzej J

    2011-02-01

    Perchlorate is a known health hazard for humans, fish, and other species. Therefore, it is important to assess the response of an ecosystem exposed to perchlorate contamination. The data reported here show that a liquid chromatography-mass spectrometry-based proteomics approach for the detection of perchlorate-reducing enzymes can be used to measure the ability of microorganisms to degrade perchlorate, including determining the current perchlorate degradation status. Signature peptides derived from chlorite dismutase (CD) and perchlorate reductase can be used as biomarkers of perchlorate presence and biodegradation. Four peptides each derived from CD and perchlorate reductase subunit A (PcrA) and seven peptides derived from perchlorate reductase subunit B (PcrB) were identified as signature biomarkers for perchlorate degradation, as these sequences are conserved in the majority of the pure and mixed perchlorate-degrading microbial cultures examined. However, chlorite dismutase signature biomarker peptides from Dechloromonas agitata CKB were found to be different from those in other cultures used and should also be included with selected CD biomarkers. The combination of these peptides derived from the two enzymes represents a promising perchlorate presence/biodegradation biomarker system. The biomarker peptides were detected at perchlorate concentrations as low as 0.1 mM and at different time points both in pure cultures and within perchlorate-reducing environmental enrichment consortia. The peptide biomarkers were also detected in the simultaneous presence of perchlorate and an alternate electron acceptor, nitrate. We believe that this technique can be useful for monitoring bioremediation processes for other anthropogenic environmental contaminants with known metabolic pathways. PMID:21115710

  11. Liste des auteurs

    OpenAIRE

    2015-01-01

    Yves Tanguy, Université de Nantes, France Jacques Verger, Université Paris Sorbonne, Paris, France Jéremy duQuesnay Adams, Dept of History, SMU, USA Étienne Wolff, Université de Paris X­Nanterre, France Claire Nouvet, Emory University, USA François Lejeune, Université de Nantes, France Wim Verbaal, Université de Gand, Belgique Thomas N. Bisson, Harvard University, USA Jean Jolivet, École Pratique des Hautes Études, Paris, France Guy Lobrichon, Collège de France, France Constant J. Mews, Sc...

  12. Table des tableaux

    OpenAIRE

    2013-01-01

    1. Ordonnances à caractère financier adoptées sous Charles VIII 22 2. Personnel de la Chambre en 1492 85 3. Personnel de la Chambre en 1498 86 4. Personnel de la Chambre en 1514 86 5. Personnel de la Chambre en 1515 87 6. Personnel de la Chambre en 1524 88 7. Personnel de la Chambre en 1540 89 8. Personnel de la Chambre en 1547 90 9. Revenu de la Bretagne 108 10. Prélèvement directs 109 11. Parties ordinaires prélevées sur le revenu de Bretagne en 1535 110 12. Revenants-bons des recettes ordi...

  13. Manifeste des digital humanities

    OpenAIRE

    2012-01-01

    Introduction au manifeste L’utilisation de l’informatique en sciences humaines et sociales est pratiquée depuis maintenant plus de quarante ans. Plusieurs voies ont été explorées au cours de cette déjà assez longue histoire. La plus récente, qui prend le nom de digital humanities, désigne une intégration intense et à plu­sieurs niveaux des technologies numériques dans tous les processus de recherche, depuis la collecte de données jusqu’à la publication. Dans ce nouveau contexte d’un travail n...

  14. Liste des figures

    OpenAIRE

    2013-01-01

    Illustrations dans le texte Villes italiennes 1. Plan de Naples en 1560. Source : Bibliothèque nationale de France, cliché BNF …………………… 8 2. Plan du nouveau tracé des rioni de Rome (1744). Source : Bernardino Bernardini, Descrizione del nuovo ripartimento de’ Rioni di Roma fatto pet ordine di N.S. Papa Benedetto XIV. Con la Notizia di quanto in essi si contiene, Rome, per Generoso Salomone, 1744, p. 225. Bibliothèque nationale de France, cliché BNF ……. 26 3. Détail du plan du quartiere de S. ...

  15. Des ignames au riz

    OpenAIRE

    Ivanoff, Jacques

    2003-01-01

    L'igname a toujours été une nourriture importante pour les populations littorales et nomades du monde insulindien. Cependant, avec l'installation du héros civilisateur Gaman le Malais chez le peuple de la reine Sibian, le riz va devenir la composante essentielle des repas moken. En intégrant Gaman en son sein, la société moken va devoir répondre au double défi posé par la menace de la riziculture et de l'islam. En donnant femme à Gaman, en adoptant le nomadisme pour échapper à l'islam ...

  16. Universos (Des) conocidos

    OpenAIRE

    Gutiérrez Vásquez, Martín Kanek

    2014-01-01

    Universos (Des) conocidos es un proyecto de creación plástica. Tiene como objetivo la construcción de imágenes poéticas sobre el universo, las estrellas y nuestra relación como humanos con ellas. El proceso consintió en conformar durante 2 años un archivo de objetos recolectados de la calle, para después construir esculturas que fueron quemadas en un acto ritual. Al final se presentó los restos quemados de las esculturas, a la par se presentaban videos del registro junto con 4 afiches q...

  17. Der Preis des Reiches

    OpenAIRE

    Wilker, Julia

    2015-01-01

    Wie schon die meisten hellenistischen Könige zeichneten sich auch die römischen Klientelherrscher in der Zeit des frühen Prinzipat durch Stitungen und Spenden an Städte, Gemeinden und Heiligtümer außerhalb ihrer eigenen Herrschatsgebiete aus. Jedoch zeigt eine genauere Analyse der Stitungsempfänger, der Verteilung und Art ihrer Gaben, dass es bei der euergetischen Praxis der Klientelherrscher nicht um eine einfach Imitation oder Fortsetzung überlebter monarchischer Traditionen ging, sond...

  18. Chauffage solaire des gaz

    OpenAIRE

    Genneviève, F.; Olalde, G.; Daguenet, M.

    1980-01-01

    Les auteurs calculent numériquement les répartitions de température d'un gaz circulant en convection forcée à travers une cavité poreuse soumise à un rayonnement solaire concentré. Ils étudient l'influence des divers paramètres du système et comparent ses performances énergétiques à celles obtenues par le dispositif étudié par G. Olalde, M. Daguenet et J. L. Peube.

  19. Bibliographie des expositions

    Directory of Open Access Journals (Sweden)

    Eléonore Fournié

    2009-09-01

    Full Text Available Autun, 1985Le Livre au siècle des Rolin, sous la dir. de Marie-Josette Perrat, Autun, Bibliothèque municipale, 8 juin-28 septembre 1985. Baltimore, 2002The Book of Kings: Art, War and the Morgan Library's Medieval Picture Bible, Baltimore, Walter Art Museum, 27 octobre-29 décembre 2002, Baltimore, Third Millennium Publishing, 2002. Bruxelles, 1937Les manuscrits à miniatures, du viiie siècle à 1350, Bruxelles, Bibliothèque royale de Belgique, 1937. Bruxelles, 1940La Bibliothèque de Marguerite ...

  20. Therapie des abdominellen Aortenaneurysmas

    Directory of Open Access Journals (Sweden)

    Rieß HC

    2014-01-01

    Full Text Available Zur invasiven elektiven und notfallmäßigen Therapie des abdominellen Aortenaneurysmas steht vor allem das offen-chirurgische und das endovaskuläre Verfahren zur Verfügung. Aufgrund einer deutlich erhöhten Mortalitätsrate im rupturierten Stadium sollte dabei stets ein elektives Vorgehen angestrebt werden. Die rechtzeitige Identifizierung erkrankter Patienten im asymptomatischen Stadium, beispielsweise im Rahmen eines Aortenscreenings für Risikogruppen, ist aus diesem Grund von größter Wichtigkeit. Trotz mehrerer randomisierter Studien zu den genannten Therapieoptionen kann bis heute keine vereinfachende Therapieempfehlung für eines der beiden konkurrierenden Verfahren ausgesprochen werden. Die Indikationsstellung erfordert stets eine sehr differenzierte Berücksichtigung aller eingehenden Faktoren. Auch ohne eine klare Empfehlung hat die endovaskuläre Versorgung des Aortenaneurysmas in vielen Ländern, so auch in Deutschland, bereits einen Anteil von über 50 % erlangt. Die kontinuierliche Verbesserung von Verfahren und Material spiegelt sich in einer signifikant kürzeren Krankenhausverweildauer und in einer niedrigeren Letalität der EVAR bei hohen technischen Erfolgsraten wider. Im Hinblick auf Langzeitergebnisse profitieren heute überwiegend ältere Personen von einer endovaskulären Aneurysma-Ausschaltung, für die aufgrund eines hohen OP-Risikos eine offen-chirurgische Versorgung nicht in Frage kommt. Zukünftig werden, bei einem vergleichbaren Outcome beider Verfahren, auch gesundheitsökonomische Aspekte eine Rolle spielen und in die Empfehlungen eingehen.

  1. Vectorization of copper complexes via biocompatible and biodegradable PLGA nanoparticles

    International Nuclear Information System (INIS)

    A double emulsion-solvent diffusion approach with fully biocompatible materials was used to encapsulate copper complexes within biodegradable nanoparticles, for which the release kinetics profiles have highlighted their potential use for a prolonged circulating administration.

  2. Biodegradation of waste PET based copolyesters in thermophilic anaerobic sludge

    Czech Academy of Sciences Publication Activity Database

    Hermanová, S.; Šmejkalová, P.; Merna, J.; Zarevúcka, Marie

    2015-01-01

    Roč. 111, Jan (2015), s. 176-184. ISSN 0141-3910 Institutional support: RVO:61388963 Keywords : poly(ethylene terephthalate) * copolymers * sludge * biodegradation * hydrolysis * waste Subject RIV: EI - Biotechnology ; Bionics Impact factor: 3.163, year: 2014

  3. Biodegradation of cycloalkane carboxylic acids in oil sand tailings

    International Nuclear Information System (INIS)

    The biodegradation of both an n-alkane and several carboxylated cycloalkanes was examined experimentally within tailings produced by the extraction of bitumen from the Athabasca oil sands. The carboxylated cycloalkanes examined were structurally similar to naphthenic acids that have been associated with the acute toxicity of oil sand tailings. The biodegradation potential of naphthenic acids was estimated by determining the biodegradation of both the carboxylated cycloalkanes and hexadecane in oil sand tailings. Carboxylated cycloalkanes were biodegraded within oil sands tailings, although compounds with methyl substitutions on the cycloalkane ring were more resistant to microbial degradation. Microbial activity against hexadecane and certain carboxylated cycloalkanes was found to be nitrogen and phosphorus limited. 21 refs., 3 refs., 1 tab

  4. Fade to Green: A Biodegradable Stack of Microbial Fuel Cells.

    Science.gov (United States)

    Winfield, Jonathan; Chambers, Lily D; Rossiter, Jonathan; Stinchcombe, Andrew; Walter, X Alexis; Greenman, John; Ieropoulos, Ioannis

    2015-08-24

    The focus of this study is the development of biodegradable microbial fuel cells (MFCs) able to produce useful power. Reactors with an 8 mL chamber volume were designed using all biodegradable products: polylactic acid for the frames, natural rubber as the cation-exchange membrane and egg-based, open-to-air cathodes coated with a lanolin gas diffusion layer. Forty MFCs were operated in various configurations. When fed with urine, the biodegradable stack was able to power appliances and was still operational after six months. One useful application for this truly sustainable MFC technology includes onboard power supplies for biodegradable robotic systems. After operation in remote ecological locations, these could degrade harmlessly into the surroundings to leave no trace when the mission is complete. PMID:26212495

  5. State-of-the-art of biodegradable composite materials

    International Nuclear Information System (INIS)

    Nowadays, the market demand for environment friendly materials is in strong growth. The biodegradable composites (biodegradable fibres and polymers) mainly extracted from renewable resources will be a major contributor to the production of new industrial high performance products partially solving the problem of waste management. At the end of the lifetime, a structural bio-composite could be be crushed and recycled through a controlled industrial composting process. This the state-of-the-art report focuses on the biopolymers the vegetable fibres properties, the mechanisms of biodegradation and the examples of biodegradable composites. Eco-design of new products requires these new materials for which a life cycle analysis is nevertheless necessary to validate their environmental benefits. (authors)

  6. Kinetics of Enzyme Biodegradation of New Synthesized Copolymers

    Directory of Open Access Journals (Sweden)

    Rosa Mateva

    2005-04-01

    Full Text Available Block copolymers of the poly-(hexanlactam-co-block-poly-(?-valerolactone from ABA-type were synthesized via anionic polymerization of hexanlactam (HL with the sodium salt of hexanlactam (Na-HL as an initiator and polymeric activator (PAC. PAC, on the base of poly-?-valerolactone (PVL, was used as a soft central block. Synthetic PVL is very attractive biomaterial - nontoxic, biocompatibility and biodegradable polyester[5-8]. Modification of HL with PVL, renders these system biodegradable[1]. Isolated copolymers were characterized by various spectroscopic techniques. The effect of the chemical and physical structure of the synthesized block copolymers on the biodegradation was investigated. Biodegradation of block copolyester amides was studied by means of lipase and involves the enzymatic hydrolysis of ester groups in PVL.

  7. Isomer-Specific Biodegradation and Chemical Oxidation of Nonylphenol

    OpenAIRE

    Lu, Zhijiang

    2014-01-01

    Nonylphenol (NP), a well-known environmental estrogen with numerous isomers, is commonly treated as a single compound in the evaluation of its environmental occurrence, fate and transport, treatment removal and toxicity. Recent studies showed that NP isomers exhibited different estrogenicity and biodegradability. However, at present little systematic information is available on its isomer-specific biodegradation and chemical oxidation under natural and engineered conditions.We comprehensively...

  8. Comparative study on the biodegradability of morpholinium herbicidal ionic liquids

    OpenAIRE

    Ławniczak, Łukasz; Materna, Katarzyna; Framski, Grzegorz; Szulc, Alicja; Syguda, Anna

    2015-01-01

    This study focused on evaluating the toxicity as well as primary and ultimate biodegradability of morpholinium herbicidal ionic liquids (HILs), which incorporated MCPA, MCPP, 2,4-D or Dicamba anions. The studied HILs were also subjected to determination of surface active properties in order to assess their influence on toxicity and biodegradability. The study was carried out with microbiota isolated from different environmental niches: sediments from river channel, garden soil, drainage trenc...

  9. Biodegradable Nanocomposite Films Based on Sodium Alginate and Cellulose Nanofibrils

    OpenAIRE

    B. Deepa; Eldho Abraham; Pothan, Laly A; Nereida Cordeiro; Marisa Faria; Sabu Thomas

    2016-01-01

    Biodegradable nanocomposite films were prepared by incorporation of cellulose nanofibrils (CNF) into alginate biopolymer using the solution casting method. The effects of CNF content (2.5, 5, 7.5, 10 and 15 wt %) on mechanical, biodegradability and swelling behavior of the nanocomposite films were determined. The results showed that the tensile modulus value of the nanocomposite films increased from 308 to 1403 MPa with increasing CNF content from 0% to 10%; however, it decreased with further...

  10. Biodegradation of Para Amino Acetanilide by Halomonas sp. TBZ3

    OpenAIRE

    Hajizadeh, Nader; Sefidi Heris, Youssof; Zununi Vahed, Sepideh; Vallipour, Javad; Hejazi, Mohammad Amin; Golabi, Sayyed Mahdi; Asadpour-Zeynali, Karim; Hejazi, Mohammad Saeid

    2015-01-01

    Background: Aromatic compounds are known as a group of highly persistent environmental pollutants. Halomonas sp. TBZ3 was isolated from the highly salty Urmia Lake of Iran. In this study, characterization of a new Halomonas isolate called Halomonas sp. TBZ3 and its employment for biodegradation of para-amino acetanilide (PAA), as an aromatic environmental pollutant, is described. Objectives: This study aimed to characterize the TBZ3 isolate and to elucidate its ability as a biodegradative age...

  11. Study of the biodegradation in soil of new generation plactics

    OpenAIRE

    Siotto,

    2011-01-01

    The intense use of plastic contributes to increase the amount of municipal waste that are generally disposed in landfill. For some applications and sectors, an important alternative to the conventional plastic materials can be found in the use of the new generation materials: the biodegradable polymers. Their use can be an alternative to landfill disposal and can thus reduce the cost of waste management and the accumulation in the environment. The biodegradable polymers, in fact, are used by ...

  12. Biodegradation of Asphalt Cement-20 by Aerobic Bacteria

    OpenAIRE

    Pendrys, John P.

    1989-01-01

    Seven gram-negative, aerobic bacteria were isolated from a mixed culture enriched for asphalt-degrading bacteria. The predominant genera of these isolates were Pseudomonas, Acinetobacter, Alcaligenes, Flavimonas, and Flavobacterium. The mixed culture preferentially degraded the saturate and naphthene aromatic fractions of asphalt cement-20. A residue remained on the surface which was resistant to biodegradation and protected the underlying asphalt from biodegradation. The most potent asphalt-...

  13. Biodegradability determination of municipal waste: an evaluation of methods

    OpenAIRE

    Godley, Andrew R.; Lewin, Kathy; Graham, Adele; Barker, H.; Smith, Richard

    2004-01-01

    The Environment Agency is required to monitor the diversion of biodegradable municipal waste (BMW) from landfill. Reliable methods are needed to measure the biodegradability of municipal waste, both as mixed municipal waste and as individually separated fractions. An evaluation of several methods was carried out using a variety of organic materials typically found in municipal solid waste. The assessment considered biological and non-biological methods to determine which provid...

  14. Critical evaluation of biodegradable polymers used in nanodrugs

    OpenAIRE

    Marin E; Briceño MI; Caballero-George C

    2013-01-01

    Edgar Marin,1–3 Maria Isabel Briceño,2 Catherina Caballero-George11Unit of Pharmacology, Center of Biodiversity and Drug Discovery, Institute of Scientific Research and High Technology Services, 2Nano Dispersions Technology, Panama, Republic of Panama; 3Department of Biotechnology, Archaria Nagarjuna University, Guntur, IndiaAbstract: Use of biodegradable polymers for biomedical applications has increased in recent decades due to their biocompatibility, biodegradability, ...

  15. Biodegradation and biocompatibility of a degradable chitosan vascular prosthesis

    OpenAIRE

    Kong, Xiaoying; Xu, Wenhua

    2015-01-01

    An instrument made by ourselves was used to fabricate biodegradable chitosan-heparin artificial vascular prosthesis with small internal diameter (2 mm) and different crosslinking degree from biodegradable chitosan, chitosan derivates and heparin. In vivo and in vitro degradation studies, inflammatory analysis and electron microscope scanning of this artificial vascular prosthesis were performed. It was observed that 50% of the prosthesis decomposed in vivo and was replaced by natural tissues....

  16. Factors influencing crude oil biodegradation by Yarrowia lipolytica

    OpenAIRE

    Tatiana Felix Ferreira; Maria Alice Zarur Coelho; Maria Helena Miguez da Rocha-Leão

    2012-01-01

    Yarrowia lipolytica is unique strictly aerobic yeast with the ability to efficiently degrade hydrophobic substrates such as n-alkenes, fatty acids, glycerol and oils. In the present work, a 2(4) full factorial design was used to investigate the influence of the independent variables of temperature, agitation, initial cell concentration and initial petroleum concentration on crude oil biodegradation. The results showed that all variables studied had significant effects on the biodegradation pr...

  17. Removal of Textile Dyestufes From Wastewater by Adsorptive Biodegradation

    OpenAIRE

    KAPDAN, İlgi KARAPINAR; KARGI, Fikret

    2000-01-01

    Removal of dyestuffs from a synthetic wastewater by adsorptive biodegradation was investigated in this study. The dyestuff adsorption capacities of granular, powdered activated carbon (GAC and PAC) and low-cost adsorbents such as zeolite, wood chips and wood ash were evaluated in order to obtain a low-cost adsorbent for use in an activated sludge unit. Then various activated sludge cultures were tested for biodegradation of a selected dyestuff. An activated sludge unit with the selected activ...

  18. Kinetics of Enzyme Biodegradation of New Synthesized Copolymers

    OpenAIRE

    Rosa Mateva; Natalia Toncheva; Lubov Yotova

    2005-01-01

    Block copolymers of the poly-(hexanlactam)-co-block-poly-(?-valerolactone) from ABA-type were synthesized via anionic polymerization of hexanlactam (HL) with the sodium salt of hexanlactam (Na-HL) as an initiator and polymeric activator (PAC). PAC, on the base of poly-?-valerolactone (PVL), was used as a soft central block. Synthetic PVL is very attractive biomaterial - nontoxic, biocompatibility and biodegradable polyester[5-8]. Modification of HL with PVL, renders these system biodegradable...

  19. Base Oils Biodegradability Prediction with Data Mining Techniques

    OpenAIRE

    Malika Trabelsi; Saloua Saidane; Sihem Ben Abdelmelek

    2010-01-01

    In this paper, we apply various data mining techniques including continuous numeric and discrete classification prediction models of base oils biodegradability, with emphasis on improving prediction accuracy. The results show that highly biodegradable oils can be better predicted through numeric models. In contrast, classification models did not uncover a similar dichotomy. With the exception of Memory Based Reasoning and Decision Trees, tested classification techniques achieved high classifi...

  20. BACTERIAL BIODEGRADATION OF PERMETRINA AND CIPERMETRINA PESTICIDES IN CULTURE LOT

    OpenAIRE

    José C. Mendoza; Yazmin S. Perea; Jaime A. Salvador; Janette A. Morales; Gabriela Pérez

    2011-01-01

    The biodegradation of permetrhin and cypermethrin (50 and 100 mg/L) with Pseudomonas putida, Pseudomonas mendocina, Chromobacterium violaceum and Burkholderia cepacia in batch reactors was studied. The strain of Pseudomonas putida and Pseudomonas mendocina showed a greater capability of biodegradation of pesticides, after 5 days, this is of 65% for both pesticides and after the 15 days it practically stays constant, being of until 95% for permetrina to 50 and 100 mg/l and for cipermetrina fr...

  1. Biodegradation of bioaccessible textile azo dyes by Phanerochaete chrysosporium

    OpenAIRE

    Martins, Maria Adosinda; Ferreira, Isabel C.F.R.; Santos, Isabel; Queiroz, Maria João R. P.; Lima, Nelson

    2000-01-01

    Azo dyes are important chemical pollutants of industrial origin. Textile azo dyes with bioaccessible groups for lignin degrading fungi, such as 2-methoxyphenol (guaiacol) and 2,6-dimethoxyphenol (syringol), were synthesised using different aminobenzoic and aminosulphonic acids as diazo components. The inocula of the best biodegradation assays were obtained from a pre-growth medium (PAM), containing one of the synthesised dyes. The results of the dye biodegradation assays were eval...

  2. Development of biodegradable magnesium alloy stents with coating

    OpenAIRE

    Lorenza Petrini; Wei Wu; Dario Gastaldi; Lina Altomare; Silvia Farè; Francesco Migliavacca; Ali Gökhan Demir; Barbara Previtali; Maurizio Vedani

    2014-01-01

    Biodegradable stents are attracting the attention of many researchers in biomedical and materials research fields since they can absolve their specific function for the expected period of time and then gradually disappear. This feature allows avoiding the risk of long-term complications such as restenosis or mechanical instability of the device when the vessel grows in size in pediatric patients. Up to now biodegradable stents made of polymers or magnesium alloys have been propose...

  3. Assessment of the biodegradability of xanthan in offshore injection water

    OpenAIRE

    Hovland, Beate

    2015-01-01

    The application of biopolymers in EOR operations is considered environmental friendly compared to synthetic polymers. However, microbial degradation of the biopolymers may lead to a deterioration of effect in EOR applications. This thesis is part of an industrial project conducted by UNI Research CIPR for Statoil ASA, were the aim is to assess biodegradation of xanthan at specific oil field conditions. Investigation of the biodegradation of xanthan was perform...

  4. Identification of Geological Forms Using Production Data Identification des formes géologiques en utilisant les données de production

    Directory of Open Access Journals (Sweden)

    Masmoudi M.

    2006-12-01

    éologiques de chenaux, de failles ou de limites de réservoirs à partir des données de tests de puits ou d'historiques de production constitue un problème délicat en ingénierie de réservoirs pétroliers. Des modèles analytiques d'interprétation de tests de puits sont utilisés dans des cas simples. Dans les cas multiphasiques ou de géométries complexes, il est nécessaire de recourir à des modèles de simulation d'écoulement de fluides. Dans cet article, nous nous proposons de résoudre un problème d'inversion de forme associé à un modèle d'écoulement diphasique eau-huile et notre objectif est d'identifier la forme et la position de corps géologiques dans un réservoir d'hydrocarbures par calage des données de production. En identification de forme, deux problèmes se posent généralement: le choix de la représentation des formes géométriques et le calcul des sensibilités. Pour calculer les gradients, des techniques de perturbation de maillages existent dans des domaines où les éléments finis sont d'utilisation courante. Dans un contexte de maillages structurés fréquemment utilisés en simulation de réservoirs, ces techniques de perturbation de maillages sont difficilement applicables. La méthode proposée est baséesur le calcul des sensibilités sur le problème continu par rapport à la géométrie des différents corps géologiques. Cette géométrie est définie par une triangulation. Les paramètres de calage sont les noeuds de la triangulation, et les gradients de la fonction objectif sont calculés par rapport aux déplacements de ces noeuds. Un algorithme d'optimisation couplé avec un simulateur d'écoulements polyphasiques a été développé. Il permet la prise en compte de contraintes géométriques sur les paramètres de calage et assure la régularité des formes obtenues. Plusieurs applications de type académique ont été effectuées. Ce qui conduit, à l'aide de calages des données de production, à une meilleure caract

  5. Les effets environnementaux des particules

    OpenAIRE

    Brignon, Jean-Marc

    2003-01-01

    En dehors de leur effet sur la santé humaine, les particules interviennent dans de nombreuses problématiques environnementales, dont le changement climatique, la formation d'ozone troposphérique, la réduction de la visibilité, et les régimes hydrologiques. L'effet des particules en termes de changement climatique est complexe et emprunte plusieurs voies. Il se traduit par des effets opposés de réchauffement ou de refroidissement de l'atmosphère, notamment selon la composition chimique des par...

  6. Médecine des voyages

    Science.gov (United States)

    Aw, Brian; Boraston, Suni; Botten, David; Cherniwchan, Darin; Fazal, Hyder; Kelton, Timothy; Libman, Michael; Saldanha, Colin; Scappatura, Philip; Stowe, Brian

    2014-01-01

    Résumé Objectif Définir la pratique de la médecine des voyages, présenter les éléments fondamentaux d’une consultation complète préalable aux voyages à des voyageurs internationaux et aider à identifier les patients qu’il vaudrait mieux envoyer en consultation auprès de professionnels de la médecine des voyages. Sources des données Les lignes directrices et les recommandations sur la médecine des voyages et les maladies liées aux voyages publiées par les autorités sanitaires nationales et internationales ont fait l’objet d’un examen. Une recension des ouvrages connexes dans MEDLINE et EMBASE a aussi été effectuée. Message principal La médecine des voyages est une spécialité très dynamique qui se concentre sur les soins préventifs avant un voyage. Une évaluation exhaustive du risque pour chaque voyageur est essentielle pour mesurer avec exactitude les risques particuliers au voyageur, à son itinéraire et à sa destination et pour offrir des conseils sur les interventions les plus appropriées en gestion du risque afin de promouvoir la santé et prévenir les problèmes médicaux indésirables durant le voyage. Des vaccins peuvent aussi être nécessaires et doivent être personnalisés en fonction des antécédents d’immunisation du voyageur, de son itinéraire et du temps qu’il reste avant son départ. Conclusion La santé et la sécurité d’un voyageur dépendent du degré d’expertise du médecin qui offre le counseling préalable à son voyage et les vaccins, au besoin. On recommande à ceux qui donnent des conseils aux voyageurs d’être conscients de l’ampleur de cette responsabilité et de demander si possible une consultation auprès de professionnels de la médecine des voyages pour tous les voyageurs à risque élevé.

  7. Tableau des chaires depuis 1800

    OpenAIRE

    2016-01-01

    TABLEAU DES CHAIRES DEPUIS 1800 Chaire ancienne Chaire nouvelle 1800 Physique mathématique Jacques-Antoine Cousin (1769-1800) Physique mathématique Jean-Baptiste Biot (1801-1862) Histoire naturelle Louis Daubenton (1778-1799) Histoire naturelle Georges Cuvier (1800-1832) 1801 Chimie Jean Darcet (1774-1801) Chimie Nicolas Vauquelin (1801-1804) 1804 Droit de la nature et des gens Mathieu-Antoine Bouchaud (1773-1804) Droit de la nature et des gens Pierre de Pastoret (1804-1821) Chimie Nicolas Va...

  8. Synthesis and characterization of polymers based on citric acid and glycerol: Its application in non-biodegradable polymers

    Directory of Open Access Journals (Sweden)

    Jaime Alfredo Mariano-Torres

    2015-01-01

    Full Text Available El notable incremento mundial en el consumo de plásticos y su l argo tiempo de residencia en el ambiente muestran la gran neces idad de productos con caracterís ticas biodegradables. En este proyecto fueron desarrollados polímeros biodegradables a base del ácido cítrico y del glicerol. La síntesis de esto s se lleva a cabo a diferentes condiciones de concentración y a temperatura constante. Se des arrollaron mediante un proceso económicamente viable. Se caracterizaron p or medio de las siguientes técnicas: Numero ácido, espectroscop ia infrarroja FTIR, índice de refracc ión, viscosidad, análisis de impacto, ensayo de tensión, dure za, calorimetría, el % de Humed ad (método de la estufa con recirculación de aire, determinación de densi dad, además de pruebas cualitativas para corroborar su biodegra dabilidad. Los polímeros elaborados fueron mezclados con una formulación de PVC grado médico, obteniendo un polímero hibrido y se pudo observar que modifica sus propiedades mecánicas.

  9. Evaluation of the biodegradation of Alaska North Slope oil in microcosms using the biodegradation model BIOB

    Directory of Open Access Journals (Sweden)

    Jagadish eTorlapati

    2014-05-01

    Full Text Available We present the details of a numerical model, BIOB that is capable of simulating the biodegradation of oil entrapped in the sediment. The model uses Monod kinetics to simulate the growth of bacteria in the presence of nutrients and the subsequent consumption of hydrocarbons. The model was used to simulate experimental results of Exxon Valdez oil biodegradation in laboratory columns (Venosa et al. (2010. In that study, samples were collected from three different islands: Eleanor Island (EL107, Knight Island (KN114A, and Smith Island (SM006B, and placed in laboratory microcosms for a duration of 168 days to investigate oil bioremediation through natural attenuation and nutrient amendment. The kinetic parameters of the BIOB model were estimated by fitting to the experimental data using a parameter estimation tool based on Genetic Algorithms (GA. The parameter values of EL107 and KN114A were similar whereas those of SM006B were different from the two other sites; in particular biomass growth at SM006B was four times slower than at the other two islands. Grain size analysis from each site revealed that the specific surface area per unit mass of sediment was considerably lower at SM006B, which suggest that the surface area of sediments is a key control parameter for microbial growth in sediments. Comparison of the BIOB results with exponential decay curves fitted to the data indicated that BIOB provided better fit for KN114A and SM006B in nutrient amended treatments, and for EL107 and KN114A in natural attenuation. In particular, BIOB was able to capture the initial slow biodegradation due to the lag phase in microbial growth. Sensitivity analyses revealed that oil biodegradation at all three locations were sensitive to nutrient concentration whereas SM006B was sensitive to initial biomass concentration due to its slow growth rate. Analyses were also performed to compare the half-lives of individual compounds with the decay rate of the overall PAH.

  10. Visual Investigation of Retrograde Phenomena and Gas Condensate Flow in Porous Media Étude visuelle des phénomènes rétrogrades et de l'écoulement des gaz de condensat en milieux poreux

    Directory of Open Access Journals (Sweden)

    Danesh A.

    2006-11-01

    és avec des mélanges synthétiques d'hydrocarbures gazeux multicomposants, mais aussi avec un condensat naturel provenant de la mer du Nord. Le comportement en écoulement polyphasique des systèmes soumis à l'essai, observé et enregistré en vidéo, est présenté ici, accompagné des données mesurées. En milieu poreux mouillé à l'eau, on a observé que le condensat se forme en film mince continu sur l'eau connée, site préférentiel de condensation. En abaissant la pression au-dessous de la cricondenbar du système, on a provoqué la croissance du condensat presque exclusivement sur les anneaux d'eau à l'entrée des pores et sur les pores aveugles. On a constaté que le condensat passe à travers les films minces même en cas de saturation faible, sans que cela améliore sa récupération. Le rythme de la baisse de pression influence le cisaillement de l'écoulement de gaz et influence fortement, on l'a constaté, la propagation du condensat. Des instabilités localisées pourraient entraîner des mouvements importants du condensat dans certaines zones poreuses, mais en aval les effets capillaires exerceraient une action retardatrice qui diminuerait la récupération du condensat. On ne doit pas penser que les rapports entre la perméabilité relative et la saturation du gaz de condensat prendront la même forme que la perméabilité relative pétrole-gaz dans le cas de récupération par un gaz en solution ou un gaz injecté.

  11. Biodegradation and surfactant-mediated biodegradation of diesel fuel by 218 microbial consortia are not correlated to cell surface hydrophobicity

    Energy Technology Data Exchange (ETDEWEB)

    Owsianiak, Mikolaj; Szulc, Alicja; Chrzanowski, Lukasz; Bogacki, Mariusz [Poznan Univ. of Technology (Poland). Inst. of Chemical Technology and Engineering; Cyplik, Pawel; Olejnik-Schmidt, Agniezka K. [Poznan Univ. of Life Sciences (Poland). Dept. of Biotechnology and Food Microbiology; Heipieper, Hermann J. [Helmholtz Centre for Environmental Research - UFZ, Leipzig (Germany). Dept. of Environmental Biotechnology

    2009-09-15

    In this study, we elucidated the role of cell surface hydrophobicity (microbial adhesion to hydrocarbons method, MATH) and the effect of anionic rhamnolipids and nonionic Triton X-100 surfactants on biodegradation of diesel fuel employing 218 microbial consortia isolated from petroleum-contaminated soils. Applied enrichment procedure with floating diesel fuel as a sole carbon source in liquid cultures resulted in consortia of varying biodegradation potential and diametrically different cell surface properties, suggesting that cell surface hydrophobicity is a conserved parameter. Surprisingly, no correlations between cell surface hydrophobicity and biodegradation of diesel fuel were found. Nevertheless, both surfactants altered cell surface hydrophobicity of the consortia in similar manner: increased for the hydrophilic and decreased for the hydrophobic cultures. In addition to this, the surfactants exhibited similar influence on diesel fuel biodegradation: Increase was observed for initially slow-degrading cultures and the opposite for fast degraders. This indicates that in the surfactant-mediated biodegradation, effectiveness of surfactants depends on the specification of microorganisms and not on the type of surfactant. In contrary to what was previously reported for pure strains, cell surface hydrophobicity, as determined by MATH, is not a good descriptor of biodegrading potential for mixed cultures. (orig.)

  12. Table des illustrations

    OpenAIRE

    2014-01-01

    COULEURS CICERI. Aladin, n° 2 (couverture) CICERI. Aladin, n° 1 CICERI. Ali-Baba, n° 2 ISABEY. Armide, n° 1 LORMIER. La Gipsy, n° 1 LORMIER. La Reine de Chypre, n° 5 LORMIER. La Tarentule, n° 2 CHASSELAT. Guillaume Tell, n° 6 LORMIER. Le Lac des fées, n° 1 CAMBON. Gustave III, n° 3 CICERI. Gustave III, n° 1 CHAPERON. Les Huguenots, n° 17 PERCIER, THIBAULT, FONTAINE. Paul et Virginie, n° 3 CHAPERON. Pierre de Médicis, n° 1 CHAPERON. Le Prophète, n° 18 CAMBON. La Reine de Chypre, n° 4 MÉNAGEO...

  13. Liste des auteurs

    OpenAIRE

    2016-01-01

    C. Alba Département de science politique et d’administration, Faculté de droit, Université autonome de Madrid, Espagne. D. Čermák Académie tchèque des sciences, Institut de sociologie, République tchèque. M. Charron Groupe de recherche sur l’innovation municipale Villes Régions Monde, INRS-Urbanisation, Culture et Société, Montréal, Canada. J.-P. Collin Groupe de recherche sur l’innovation municipale Villes Régions Monde, INRS-Urbanisation, Culture et Société, Montréal, Canada. A. Hazan Dire...

  14. Pourquoi des monocristaux ?

    OpenAIRE

    Velázquez, Matias

    2010-01-01

    D'une façon générale, les monocristaux permettent d'étudier les caractères intrinsèque et anisotrope (tensoriel) de leurs propriétés physiques, statiques ou dynamiques. Ils constituent, dans l'industrie, le maillon indispensable de la chaîne de valeur allant des matières premières aux systèmes - matières premières->monocristal->composant->systèmes -. Leur perfection à l'échelle atomique et l'anisotropie de leur(s) réponse(s) à un paramètre de contrôle (champ magnétique, champ électrique, cont...

  15. La confusion des langues

    OpenAIRE

    Descombes, Vincent

    1998-01-01

    La notion de “ description épaisse ” demande à être éclaircie. S'agit-il d'une authentique description ? Non, selon ceux qui l'entendent plutôt dans l'acception de Clifford Geertz. Elle serait plutôt une interprétation de matériaux eux-mêmes de nature interprétative, à la manière de l'explication de texte. Oui, pourtant selon le philosophe (Gilbert Ryle) auquel Geertz a emprunté le concept : la description épaisse est seulement une description mince compliquée par des précisions de type adver...

  16. La confusion des langues

    OpenAIRE

    Descombes, Vincent

    2013-01-01

    La notion de « description épaisse » demande à être éclaircie. S’agit-il d’une authentique description ? Non, selon ceux qui l’entendent dans l’acception de C. Geertz. Elle serait plutôt une interprétation de matériaux eux-mêmes de nature interprétative, à la manière de l’explication de texte. Oui, pourtant, selon le philosophe (G. Ryle) auquel Geertz a emprunté le concept : la description épaisse est seulement une description mince compliquée par des précisions de type adverbial. L’usage con...

  17. Charakterisierung des Burkholderia cenocepacia Aquaglyceroporins

    OpenAIRE

    Wree, Dorothea

    2010-01-01

    In der vorliegenden Arbeit wurde ein Aquaglyceroporin des Krankenhausproblemkeims Burkholderia cenocepacia, BccGlpF, charakterisiert. Unter besonderer Beobachtung stand die Struktur-Funktionsbeziehung der eigentlich kochkonservierten NPA-Motive.

  18. Marais Des Cygnes Wildlife Area

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — This brochure is for the Marais des Cygnes Wildlife Area, managed by Kansas Department of Wildlife, Parks and Tourism, and located in the floodplain of the Marais...

  19. Des changements attendus en Libye

    OpenAIRE

    Martinez, Luis

    2004-01-01

    Depuis la suspension de l'embargo en avril 1999, la Libye du colonel Kadhafi cherche à retrouver sa place dans le concert des nations. Mise au ban des nations durant une décennie, en raison des accusations portées contre sa responsabilité dans l'attentat de la PanAm à Lockerbie, la Libye a fait un retour remarqué sur la scène internationale. La Libye d'après l'embargo souhaite résolument mettre un terme à la politique révolutionnaire des années 1970 et 1980. Depuis quatre ans, Kadhafi cher...

  20. La recherche des documents (heuristique)

    OpenAIRE

    Langlois, Charles-Victor; Seignobos, Charles

    2014-01-01

    L’histoire se fait avec des documents. Les documents sont les traces qu’ont laissées les pensées et les actes des hommes d’autrefois. Parmi les pensées et les actes des hommes, il en est très peu qui laissent des traces visibles, et ces traces, lorsqu’il s’en produit, sont rarement durables : il suffit d’un accident pour les effacer. Or, toute pensée et tout acte qui n’a pas laissé de traces, directes ou indirectes, ou dont les traces visibles ont disparu, est perdu pour l’histoire : c’est co...

  1. Forschung des DLR zum Verkehrsmanagement

    OpenAIRE

    Brockfeld, Elmar

    2011-01-01

    Vortrag zu aktuellen Forschungsthemen des DLR-Instituts für Verkehrssystemtechnik. Schwerpunkt Verkerhsdatenerfassung mit FCD, Taxi-FCD-System Berlin und stationäre sowie dynamische Erfassung mit Bluetooth und Wifi.

  2. Biodegradability enhancement of municipal landfill leachate

    Directory of Open Access Journals (Sweden)

    Pi Kewu

    2008-12-01

    Full Text Available The method of enhancing the biodegradability of landfill leachate via air stripping followed by coagulation/ultrafiltration (UF processes is introduced. In this study, the air stripping process obtained a removal efficiency of 88.6% for ammonia nitrogen (NH3-N, at an air-to-liquid ratio (A/L of 3 300 (pH = 11 and after 18 h of stripping. The single coagulation process increased the BOD (biological oxygen demand/COD (chemical oxygen demand ratio by 0.089 with a FeCl3 dosage of 570 mg/L, at pH 7.0, and the single UF process increased the BOD/COD ratio from 0.049 to 0.311. However, the combination of coagulation and UF increased the BOD/COD ratio from 0.049 to 0.423, and the final BOD, COD, NH3-N, and colour of the leachate were 1 023 mg/L, 2 845 mg/L, 145 mg/L, and 2 056, respectively, when a 3 kDa molecular weight cut-off (MWCO membrane was used at an operating pressure of 0.7 MPa. In the ultrafiltration process, the average solution flux (JV, concentration multiple (MC, and retention rate (R for the COD were 107.3 L/(m2·h, 6.3, and 84.2%, respectively.

  3. Microbial ecology of bacterially mediated PCB biodegradation

    International Nuclear Information System (INIS)

    The roles of plasmid mediated and consortia mediated polychlorinated biphenyl (PCB) biodegradation by bacterial populations isolated from PCB contaminated freshwater sediments were investigated. PCB degrading bacteria were isolated by DNA:DNA colony hybridization, batch enrichments, and chemostat enrichment. Analysis of substrate removal and metabolite production were done using chlorinated biphenyl spray plates, reverse phase high pressure liquid chromatography, Cl- detection, and 14C-labeled substrate mineralization methods. A bacterial consortium, designated LPS10, involved in a concerted metabolic attack on chlorinated biphenyls, was shown to mineralize 4-chlorobiphenyl (4CB) and 4,4'-dichlorobiphenyl (4,4' CB). The LPS10 consortium was isolated by both batch and chemostat enrichment using 4CB and biphenyl (BP) as sole carbon source and was found to have tree bacterial isolates that predominated; these included: Pseudomonas, testosteroni LPS10A which mediated the breakdown of 4CB and 4,4' CB to the putative meta-cleavage product and subsequently to 4-chlorobenzoic acid (4CBA), an isolate tentatively identified as an Arthrobacter sp. LPS10B which mediated 4CBA degradation, and Pseudomonas putida by A LPS10C whose role in the consortium has not been determined

  4. Equilibrium gold nanoclusters quenched with biodegradable polymers.

    Science.gov (United States)

    Murthy, Avinash K; Stover, Robert J; Borwankar, Ameya U; Nie, Golay D; Gourisankar, Sai; Truskett, Thomas M; Sokolov, Konstantin V; Johnston, Keith P

    2013-01-22

    Although sub-100 nm nanoclusters of metal nanoparticles are of interest in many fields including biomedical imaging, sensors, and catalysis, it has been challenging to control their morphologies and chemical properties. Herein, a new concept is presented to assemble equilibrium Au nanoclusters of controlled size by tuning the colloidal interactions with a polymeric stabilizer, PLA(1k)-b-PEG(10k)-b-PLA(1k). The nanoclusters form upon mixing a dispersion of ~5 nm Au nanospheres with a polymer solution followed by partial solvent evaporation. A weakly adsorbed polymer quenches the equilibrium nanocluster size and provides steric stabilization. Nanocluster size is tuned from ~20 to ~40 nm by experimentally varying the final Au nanoparticle concentration and the polymer/Au ratio, along with the charge on the initial Au nanoparticle surface. Upon biodegradation of the quencher, the nanoclusters reversibly and fully dissociate to individual ~5 nm primary particles. Equilibrium cluster size is predicted semiquantitatively with a free energy model that balances short-ranged depletion and van der Waals attractions with longer-ranged electrostatic repulsion, as a function of the Au and polymer concentrations. The close spacings of the Au nanoparticles in the clusters produce strong NIR extinction over a broad range of wavelengths from 650 to 900 nm, which is of practical interest in biomedical imaging. PMID:23230905

  5. Microporous biodegradable polyurethane membranes for tissue engineering.

    Science.gov (United States)

    Tsui, Yuen Kee; Gogolewski, Sylwester

    2009-08-01

    Microporous membranes with controlled pore size and structure were produced from biodegradable polyurethane based on aliphatic diisocyanate, poly(epsilon-caprolactone) diol and isosorbide chain extender using the modified phase-inversion technique. The following parameters affecting the process of membrane formation were investigated: the type of solvent, solvent-nonsolvent ratio, polymer concentration in solution, polymer solidification time, and the thickness of the polymer solution layer cast on a substrate. The experimental systems evaluated were polymer-N,N-dimethylformamide-water, polymer-N,N-dimethylacetamide-water and polymer-dimethylsulfoxide-water. From all three systems evaluated the best results were obtained for the system polymer-N,N-dimethylformamide-water. The optimal conditions for the preparation of microporous polyurethane membranes were: polymer concentration in solution 5% (w/v), the amount of nonsolvent 10% (v/v), the cast temperature 23 degrees C, and polymer solidification time in the range of 24-48 h depending on the thickness of the cast polymer solution layer. Membranes obtained under these conditions had interconnected pores, well defined pore size and structure, good water permeability and satisfactory mechanical properties to allow for suturing. Potential applications of these membranes are skin wound cover and, in combination with autogenous chondrocytes, as an "artificial periosteum" in the treatment of articular cartilage defects. PMID:19301104

  6. Kinetics of dimethoate biodegradation in bacterial system

    Directory of Open Access Journals (Sweden)

    Manisha DebMandal

    2011-11-01

    Full Text Available The present study is an investigation on the kinetics of dimethoate biodegradation and an estimation of residual dimethoate in bacterial culture by spectrophotometry. The methylene chloride extract of the culture medium was used for determination of dimethoate through its reaction with 1 chloro-2, 4 dinitrobenzene to produce methylamine whose absorbance at 505 nm gave an estimation of dimethoate content. The dimethoate standard curve follows Beer’s law at 505 nm with a slope of 0.0129 absorbance units per µg/mL. The regression equation relating concentration of dimethoate (x with the absorbance is (y: y = 0.037 + 0.0129x. The amount of residual dimethoate after 7 days were 0, 4, 17, 28 and 29 µg/mL; the rate constants were 0.775, 0.305, 0.225, 0.167 and 0.127 each per day, and the efficiency of dimethoate degradation were 100%, 96%, 83%, 72% and 71%, for Bacillus licheniformis, Pseudomonas aeruginosa, Aeromonas hydrophila, Proteus mirabilis and Bacillus pumilus respectively. Dimethoate remediation could be attained through bacterial metabolism of the pesticide and colorimetric analysis might be useful in the estimation of dimethoate within a detection limit of 5-100 µg/mL.

  7. Biodegradability enhancement of municipal landfill leachate

    Institute of Scientific and Technical Information of China (English)

    Pi Kewu; Gong Wenqi

    2008-01-01

    The method of enhancing the biodegradability of landfill leachate via air stripping followed by coagulation/ultrafiltration (UF) processes is introduced. In this study, the air stripping process obtained a removal efficiency of 88.6% for ammonia nitrogen (NH3-N), at an air-to-liquid ratio (A/L) of 3 300 (pH=11) and after 18 h of stripping. The single coagulation process increased the BOD (biological oxygen demand)/COD (chemical oxygen demand) ratio by 0.089 with a FeCl3 dosage of 570 mg/L, at pH 7.0, and the single UF process increased the BOD/COD ratio from 0.049 to 0.311. However, the combination of coagulation and UF increased the BOD/COD ratio from 0.049 to 0.423, and the final BOD, COD, NH3-N, and colour of the leachate were 1 023 mg/L, 2 845 mg/L, 145 mg/L, and 2 056, respectively, when a 3 kDa molecular weight cut-off (MWCO) membrane was used at an operating pressure of 0.7 MPa. In the ultrafiltration process, the average solution flux (JⅤ), concentration multiple (MC), and retention rate (R) for the COD were 107.3 L/(m2.h), 6.3, and 84.2%, respectively.

  8. Electrospun biodegradable polymers loaded with bactericide agents

    Directory of Open Access Journals (Sweden)

    Ramaz Katsarava

    2016-03-01

    Full Text Available Development of materials with an antimicrobial activity is fundamental for different sectors, including medicine and health care, water and air treatment, and food packaging. Electrospinning is a versatile and economic technique that allows the incorporation of different natural, industrial, and clinical agents into a wide variety of polymers and blends in the form of micro/nanofibers. Furthermore, the technique is versatile since different constructs (e.g. those derived from single electrospinning, co-electrospinning, coaxial electrospinning, and miniemulsion electrospinning can be obtained to influence the ability to load agents with different characteristics and stability and to modify the release behaviour. Furthermore, antimicrobial agents can be loaded during the electrospinning process or by a subsequent coating process. In order to the mitigate burst release effect, it is possible to encapsulate the selected drug into inorganic nanotubes and nanoparticles, as well as in organic cyclodextrine polysaccharides. In the same way, processes that involve covalent linkage of bactericide agents during surface treatment of electrospun samples may also be considered. The present review is focused on more recent works concerning the electrospinning of antimicrobial polymers. These include chitosan and common biodegradable polymers with activity caused by the specific load of agents such as metal and metal oxide particles, quaternary ammonium compounds, hydantoin compounds, antibiotics, common organic bactericides, and bacteriophages.

  9. Pharmacokinetics and biodegradation of chitosan in rats

    Science.gov (United States)

    Li, Hui; Jiang, Zhiwen; Han, Baoqin; Niu, Shuyi; Dong, Wen; Liu, Wanshun

    2015-10-01

    Chitosan, an excellent biomedical material, has received a widespread in vivo application. In contrast, its metabolism and distribution once being implanted were less documented. In this study, the pharmacokinetics and biodegradation of fluorescein isothiocyanate (FITC) labeled and muscle implantation administrated chitosan in rats were investigated with fluorescence spectrophotometry, histological assay and gel chromatography. After implantation, chitosan was degraded gradually during its distribution to diverse organs. Among the tested organs, liver and kidney were found to be the first two highest in chitosan content, which was followed by heart, brain and spleen. Urinary excretion was believed to be the major pathway of chitosan elimination, yet 80% of chitosan administered to rats was not trackable in their urine. This indicated that the majority of chitosan was degraded in tissues. In average, the molecular weight of the degradation products of chitosan in diverse organs and urine was found to be <65 kDa. This further confirmed the in vivo degradation of chitosan. Our findings provided new evidences for the intensive and safe application of chitosan as a biomedical material.

  10. Eine erste Analyse des 'Bildungsgutscheins'

    OpenAIRE

    Bruttel, Oliver

    2003-01-01

    Durch die Einführung des Systems des so genannten „Bildungsgutscheins“ hat sich die Leistungserbringung der budgetmäßig wichtigsten Maßnahme der aktiven Arbeitsmarktpolitik seit dem 1. Januar 2003 grundlegend verändert. Wie ist das neue Instrument der Arbeitsmarktpolitik ausgestaltet und wie aus theoretischer und aus praktischer Sicht zu beurteilen? Welche Probleme ergeben sich und welche Alternativen bestehen?

  11. Parallel pathways of ethoxylated alcohol biodegradation under aerobic conditions.

    Science.gov (United States)

    Zembrzuska, Joanna; Budnik, Irena; Lukaszewski, Zenon

    2016-07-01

    Non-ionic surfactants (NS) are a major component of the surfactant flux discharged into surface water, and alcohol ethoxylates (AE) are the major component of this flux. Therefore, biodegradation pathways of AE deserve more thorough investigation. The aim of this work was to investigate the stages of biodegradation of homogeneous oxyethylated dodecanol C12E9 having 9 oxyethylene subunits, under aerobic conditions. Enterobacter strain Z3 bacteria were chosen as biodegrading organisms under conditions with C12E9 as the sole source of organic carbon. Bacterial consortia of river water were used in a parallel test as an inoculum for comparison. The LC-MS technique was used to identify the products of biodegradation. Liquid-liquid extraction with ethyl acetate was selected for the isolation of C12E9 and metabolites from the biodegradation broth. The LC-MS/MS technique operating in the multiple reaction monitoring (MRM) mode was used for quantitative determination of C12E9, C12E8, C12E7 and C12E6. Apart from the substrate, the homologues C12E8, C12E7 and C12E6, being metabolites of C12E9 biodegradation by shortening of the oxyethylene chain, as well as intermediate metabolites having a carboxyl end group in the oxyethylene chain (C12E8COOH, C12E7COOH, C12E6COOH and C12E5COOH), were identified. Poly(ethylene glycols) (E) having 9, 8 and 7 oxyethylene subunits were also identified, indicating parallel central fission of C12E9 and its metabolites. Similar results were obtained with river water as inoculum. It is concluded that AE, under aerobic conditions, are biodegraded via two parallel pathways: by central fission with the formation of PEG, and by Ω-oxidation of the oxyethylene chain with the formation of carboxylated AE and subsequent shortening of the oxyethylene chain by a single unit. PMID:27037882

  12. Des cartographies de connaissances pour un pilotage des ressources humaines et des processus RH

    OpenAIRE

    Sellin, Kelly; Dudezert, Aurélie

    2010-01-01

    La gestion des ressources humaines s'inscrit dans la stratégie des organisations, désireuses de se démarquer d'une concurrence forte et de développer un avantage concurrentiel durable, au travers des connaissances et compétences dont elles disposent. Or, les fonctions RH sont confrontées à une dichotomie court terme/long terme, répondant à la fois aux exigences de l'opérationnel et à une nécessaire gestion anticipée des hommes et de leurs compétences pour répondre aux besoins présents et futu...

  13. Chronique des Archives 2010-2011

    OpenAIRE

    Eichenlaub, Jean-Luc

    2012-01-01

    La Chronique des Archives rendant compte des activités 2009 est parue dans la Revue d’Alsace no136, 2010, p. 391‑397. Le lecteur a pu avoir un aperçu des activités des Archives départementales (Bas‑Rhin, Haut‑Rhin, Territoire de Belfort) et des archives municipales de Belfort, Colmar, Erstein, Guebwiller, Illkirch, Illzach, Ingersheim, Mulhouse, Munster, Saint-Louis, Turckheim, Strasbourg. Il n’y a pas eu de Chronique des Archives complète dans la Revue d’Alsace no137, 2011, mais une page con...

  14. Application des polymeres a la protection des surfaces metalliques et a la retention des colorants.

    OpenAIRE

    MEDJAHED, Kouider

    2014-01-01

    Après une brevet présentation des travaux envisagés le premier objectif est consacré à la synthèse et la caractérisation des copolymères à bas de poli(4-vinylpyridine) 5P4VP)cette partie de synthèse se compose de trois Étapes

  15. Intrinsic and Stimulated In Situ Biodegradation of Hexachlorocyclohexane (HCH)

    International Nuclear Information System (INIS)

    The feasibility of the biodegradation of HCH and its intermediates has been investigated. A recent characterisation of two sites in The Netherlands has shown intrinsic biodegradation of HCH. At one site, breakdown products (monochlorobenzene, benzene and chlorophenol) were found in the core of the HCH-plume, whereas the HCH-concentration decreased over time and space. Characterisation of a second, industrial site indicated less intrinsic biodegradation and the need to stimulate biodegradation. In the laboratory, enhanced HCH degradation was tested with soil and groundwater material from both sites, and the required conversion to the intermediates benzene and monochlorobenzene was demonstrated. Furthermore, the biodegradation of these intermediates could be initiated by adding low amounts of oxygen (<5%). Adding nitrate enhanced this degradation. We hypothesise that this occurs through anaerobic nitrate reducing conversion of oxidised intermediates.At the non-industrial other site, intrinsic degradation took place, as shown in the laboratory experiments. Interpretation of the field data with computer codes Modflow and RT3D was performed. As a result of the modelling study, it has been proposed to monitor natural attenuation for several years before designing the final approach.At the industrial site, the results of the batch experiments are applied. Anaerobic HCH degradation to monochlorobenzene and benzene is stimulated via the addition of an electron donor.Infiltration facilities have been installed at the site to create an anaerobic infiltration zone in which HCH will be degraded, and these facilities are combined with the redevelopment of the site

  16. Adsorption and biodegradation of antidiabetic pharmaceuticals in soils.

    Science.gov (United States)

    Mrozik, Wojciech; Stefańska, Justyna

    2014-01-01

    Pharmaceuticals are emerging contaminants in the natural environment. Most studies of the environmental fate of these chemicals focus on their behavior in wastewater treatment processes and in sewage sludge. Little is known about their behavior in soils. In this study adsorption and biodegradation of four antidiabetic pharmaceuticals - glimepiride, glibenclamide, gliclazide and metformin - were examined in three natural soils. The sorption of sulfonylurea derivatives was high (higher than sulfonylurea herbicides for example), whereas metformin showed high mobility. Desorption rates were highest for metformin. Sorption isotherms in two of three soils fitted best to the Freundlich model. Despite their high affinity to for soil surfaces, biodegradation studies revealed that transformation of the drugs occurred. Biodegradation results were described by pseudo-first order kinetics with half-life values from 5 to over 120 d (under aerobic conditions) and indicate that none of the tested drugs can be classified as quickly biodegradable. Biodegradation under anoxic conditions was much slower; often degrading by less than 50% during time of the experiment. PMID:24083899

  17. [Biodegradation characteristics of organic pollutants contained in tannery wastewater].

    Science.gov (United States)

    Wang, Yong; Li, Wei-Guang; Yang, Li; Su, Cheng-Yuan

    2013-02-01

    In the batch experiments inoculated with activated sludge from tannery wastewater treatment plant, biodegradation characteristics and kinetics of three tanning agents, naphthalene-2-sulfonic sodium, tannic acid and bayberry tannin, were studied under aerobic and anaerobic conditions. And the aerobic/anaerobic biodegradation laws of real tannery wastewater with respect to COD change were also investigated using the same batch experiments. The results showed aerobic degradation was superior to anaerobic degradation for tanning agent removal and mineralization. The removal rates of naphthalene-2-sulfonic sodium, tannic acid and bayberry tannin by aerobic biodegradation were >90% , >90% and 50% -75% , respectively whereas 10%-40%, >95% and 20% -30%, respectively by anaerobic degradation. In terms of COD removal about tannic acid biodegradation, the removal rates under aerobic and anaerobic conditions were >75% and or= 70 mg.L-1 was toxic to microorganism leading to a significant decline of kinetic constants. Biodegradation of real tannery wastewater under aerobic and anaerobic conditions represented obvious stage characteristics and the COD concentration had a good linear correlation with reaction time in the phases of fast degradation and slow degradation. The aerobic maximum specific degradation rate wqas 11.6 times higher of anaerobic degradation. PMID:23668129

  18. Biodegradable and edible gelatine actuators for use as artificial muscles

    Science.gov (United States)

    Chambers, L. D.; Winfield, J.; Ieropoulos, I.; Rossiter, J.

    2014-03-01

    The expense and use of non-recyclable materials often requires the retrieval and recovery of exploratory robots. Therefore, conventional materials such as plastics and metals in robotics can be limiting. For applications such as environmental monitoring, a fully biodegradable or edible robot may provide the optimum solution. Materials that provide power and actuation as well as biodegradability provide a compelling dimension to future robotic systems. To highlight the potential of novel biodegradable and edible materials as artificial muscles, the actuation of a biodegradable hydrogel was investigated. The fabricated gelatine based polymer gel was inexpensive, easy to handle, biodegradable and edible. The electro-mechanical performance was assessed using two contactless, parallel stainless steel electrodes immersed in 0.1M NaOH solution and fixed 40 mm apart with the strip actuator pinned directly between the electrodes. The actuation displacement in response to a bias voltage was measured over hydration/de-hydration cycles. Long term (11 days) and short term (1 hour) investigations demonstrated the bending behaviour of the swollen material in response to an electric field. Actuation voltage was low (robotics.

  19. Biodegradable and radically polymerized elastomers with enhanced processing capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Ifkovits, Jamie L; Burdick, Jason A [Department of Bioengineering, University of Pennsylvania, Philadelphia, PA 19104 (United States); Padera, Robert F [Department of Pathology, Brigham and Women' s Hospital, Harvard Medical School, Boston, MA 02115 (United States)], E-mail: burdick2@seas.upenn.edu

    2008-09-01

    The development of biodegradable materials with elastomeric properties is beneficial for a variety of applications, including for use in the engineering of soft tissues. Although others have developed biodegradable elastomers, they are restricted by their processing at high temperatures and under vacuum, which limits their fabrication into complex scaffolds. To overcome this, we have modified precursors to a tough biodegradable elastomer, poly(glycerol sebacate) (PGS) with acrylates to impart control over the crosslinking process and allow for more processing options. The acrylated-PGS (Acr-PGS) macromers are capable of crosslinking through free radical initiation mechanisms (e.g., redox and photo-initiated polymerizations). Alterations in the molecular weight and % acrylation of the Acr-PGS led to changes in formed network mechanical properties. In general, Young's modulus increased with % acrylation and the % strain at break increased with molecular weight when the % acrylation was held constant. Based on the mechanical properties, one macromer was further investigated for in vitro and in vivo degradation and biocompatibility. A mild to moderate inflammatory response typical of implantable biodegradable polymers was observed, even when formed as an injectable system with redox initiation. Moreover, fibrous scaffolds of Acr-PGS and a carrier polymer, poly(ethylene oxide), were prepared via an electrospinning and photopolymerization technique and the fiber morphology was dependent on the ratio of these components. This system provides biodegradable polymers with tunable properties and enhanced processing capabilities towards the advancement of approaches in engineering soft tissues.

  20. Intrinsic and Stimulated In Situ Biodegradation of Hexachlorocyclohexane (HCH)

    Energy Technology Data Exchange (ETDEWEB)

    Langenhoff, A. A. M., E-mail: a.a.m.langenhoff@mep.tno.nl; Staps, J. J. M. [TNO Environmental, Energy and Process Innovation, Department of Environmental Biotechnology (Netherlands); Pijls, C.; Alphenaar, A. [Tauw Milieu Consultancy (Netherlands); Zwiep, G. [Akzo Nobel Chemicals (Netherlands); Rijnaarts, H. H. M. [TNO Environmental, Energy and Process Innovation, Department of Environmental Biotechnology (Netherlands)

    2002-05-15

    The feasibility of the biodegradation of HCH and its intermediates has been investigated. A recent characterisation of two sites in The Netherlands has shown intrinsic biodegradation of HCH. At one site, breakdown products (monochlorobenzene, benzene and chlorophenol) were found in the core of the HCH-plume, whereas the HCH-concentration decreased over time and space. Characterisation of a second, industrial site indicated less intrinsic biodegradation and the need to stimulate biodegradation. In the laboratory, enhanced HCH degradation was tested with soil and groundwater material from both sites, and the required conversion to the intermediates benzene and monochlorobenzene was demonstrated. Furthermore, the biodegradation of these intermediates could be initiated by adding low amounts of oxygen (<5%). Adding nitrate enhanced this degradation. We hypothesise that this occurs through anaerobic nitrate reducing conversion of oxidised intermediates.At the non-industrial other site, intrinsic degradation took place, as shown in the laboratory experiments. Interpretation of the field data with computer codes Modflow and RT3D was performed. As a result of the modelling study, it has been proposed to monitor natural attenuation for several years before designing the final approach.At the industrial site, the results of the batch experiments are applied. Anaerobic HCH degradation to monochlorobenzene and benzene is stimulated via the addition of an electron donor.Infiltration facilities have been installed at the site to create an anaerobic infiltration zone in which HCH will be degraded, and these facilities are combined with the redevelopment of the site.

  1. Biodegradable HEMA-based hydrogels with enhanced mechanical properties.

    Science.gov (United States)

    Moghadam, Mohamadreza Nassajian; Pioletti, Dominique P

    2016-08-01

    Hydrogels are widely used in the biomedical field. Their main purposes are either to deliver biological active agents or to temporarily fill a defect until they degrade and are followed by new host tissue formation. However, for this latter application, biodegradable hydrogels are usually not capable to sustain any significant load. The development of biodegradable hydrogels presenting load-bearing capabilities would open new possibilities to utilize this class of material in the biomedical field. In this work, an original formulation of biodegradable photo-crosslinked hydrogels based on hydroxyethyl methacrylate (HEMA) is presented. The hydrogels consist of short-length poly(2-hydroxyethyl methacrylate) (PHEMA) chains in a star shape structure, obtained by introducing a tetra-functional chain transfer agent in the backbone of the hydrogels. They are cross-linked with a biodegradable N,O-dimethacryloyl hydroxylamine (DMHA) molecule sensitive to hydrolytic cleavage. We characterized the degradation properties of these hydrogels submitted to mechanical loadings. We showed that the developed hydrogels undergo long-term degradation and specially meet the two essential requirements of a biodegradable hydrogel suitable for load bearing applications: enhanced mechanical properties and low molecular weight degradation products. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1161-1169, 2016. PMID:26061346

  2. Biodegradable Polymers in Bone Tissue Engineering

    Directory of Open Access Journals (Sweden)

    Leon E. Govaert

    2009-07-01

    Full Text Available The use ofdegradable polymers in medicine largely started around the mid 20th century with their initial use as in vivo resorbing sutures. Thorough knowledge on this topic as been gained since then and the potential applications for these polymers were, and still are, rapidly expanding. After improving the properties of lactic acid-based polymers, these were no longer studied only from a scientific point of view, but also for their use in bone surgery in the 1990s. Unfortunately, after implanting these polymers, different foreign body reactions ranging from the presence of white blood cells to sterile sinuses with resorption of the original tissue were observed. This led to the misconception that degradable polymers would, in all cases, lead to inflammation and/or osteolysis at the implantation site. Nowadays, we have accumulated substantial knowledge on the issue of biocompatibility of biodegradable polymers and are able to tailor these polymers for specific applications and thereby strongly reduce the occurrence of adverse tissue reactions. However, the major issue of biofunctionality, when mechanical adaptation is taken into account, has hitherto been largely unrecognized. A thorough understanding of how to improve the biofunctionality, comprising biomechanical stability, but also visualization and sterilization of the material, together with the avoidance of fibrotic tissue formation and foreign body reactions, may greatly enhance the applicability and safety of degradable polymers in a wide area of tissue engineering applications. This review will address our current understanding of these biofunctionality factors, and will subsequently discuss the pitfalls remaining and potential solutions to solve these problems.

  3. CCC/WPA study : Des Lacs NWR

    Data.gov (United States)

    US Fish and Wildlife Service, Department of the Interior — Summary of the Civilian Conservation Corps (CCC) camp at Des Lacs National Wildlife Refuge from July 1935-May 1942 to carry on restoration and development of Des...

  4. Gestion des connaissances des firmes globales : entre pratiques de codification et pratiques de diffusion

    OpenAIRE

    Paraponaris, Claude; Simoni, Gilda

    2004-01-01

    Le management des connaissances suscite beaucoup d'interrogations au sujet des méthodes mises en œuvre. Cet article propose une étude des pratiques de management des connaissances au sein de firmes multinationales. Deux résultats principaux sont dégagés. Nous montrons d'une part que plusieurs méthodes assez différentes du point de vue des objectifs et des usages peuvent être articulées au sein d'une même entreprise. Nous proposons également une typologie de pratiques de gestion des connaissan...

  5. Utilisation de produits organiques oxygénés comme carburants et combustibles dans les moteurs. Deuxième partie : Les différentes filières d'obtention des carburols. Analyse technico-économique Using Oxygenated Organic Products As Fuels in Engines. Part Two: Different Systems for Producing Alcohol Fuels. Technico-Economic Analysis

    Directory of Open Access Journals (Sweden)

    Chauvel A.

    2006-11-01

    Full Text Available Parmi les produits à même d'être substitués aux hydrocarbures pour la constitution des carburants, les composés organiques oxygénés occupent une place prépondérante à cause de leurs caractéristiques favorables à la combustion dans les moteurs, qu'ils soient employés purs ou mélangés (seuls ou à plusieurs aux hydrocarbures, constituants des carburants classiques. Dans cet article, ces composés oxygénés sont désignés sous le nom de carburols. Alors que l'objet de la première partie de l'étude a été d'examiner les conséquences techniques de l'emploi de ces produits sur les circuits de distribution et le fonctionnement des véhicules, il s'agit dans la présente partie d'analyser les caractéristiques technico-économiques de leur fabrication. En particulier, on y aborde successivement les points suivants : - disponibilités en matières premières : ressources fossiles et végétales ; - analyse technique des divers modes d'obtention - analyse économique ; - programmes nationaux. Among products that can be substituted for hydrocarbons for producing fuels, oxygenated organic compounds occupy a preponderant position because of their favorable characteristics for combustion in engines whether they are used in a pure form or in mixtures (alone or severally with hydrocarbons which are used to make up conventional fuels. In this article these oxygenated compounds are given the name carburols (alcohol fuels. Whereas the aim of Part 1 was to examine the technical consequences of using such products in distribution circuits and for vehicle operating, Part 2 is an analysis of the technico-economic aspects of manufacturing them. In particular, the following points are taken up successively: (a availabilities of raw materials. fossil and vegetebal resources; (b technical analysis of various production methods; (c economic analysis; (d national programs. Depending on the amounts involved, a distinction is made among alternative

  6. Terre des hommes

    CERN Multimedia

    Staff Association

    2012-01-01

    Transformez votre téléphone portable en geste de solidarité ! Collecte du 12 au 23 novembre 2012   Faites un geste simple et utile en déposant vos téléphones portables inutilisés dans les urnes installées dans les trois restaurants du CERN. En Suisse, une personne change tous les 12 à 18 mois de téléphone portable. La plupart de nos vieux appareils sont simplement laissés à l’abandon avec comme seule fonction de parer une éventuelle panne à venir. On  estime ainsi que 8 millions de portables sont inutilisés, alors qu'entre 30 et 50% peuvent être réutilisés. L'action Solidarcomm leur offre une deuxième vie ! Terre des Hommes Suisse, dans le cadre de la campagne Solidarcomm, collecte et valorise vos téléphones inutilis&...

  7. Onlinespieler abseits des Mainstreams

    Directory of Open Access Journals (Sweden)

    Harald Baumgartlinger

    2012-12-01

    Full Text Available MMO(RPGs „Massively Multiplayer Online (Role-Playing Games“ nehmen einen Sonderstatus unter den Onlinespielen ein, welcher durch den wachsenden wirtschaftlichen Erfolg, insbesondere durch den „breakthrough hit“ (Duchenaut et al. 2006: 407 World of Warcraft (WoW, auch an Bedeutung für die Medien- und Kommunikationswissenschaft gewinnt (vgl. Inderst 2009: 15; vgl. Seifert/Jöckel 2008: 297. Der Primus des Genres, WoW, repräsentiert gemeinsam mit einigen nahezu identen Titeln insgesamt 85 Prozent der gespielten MMOGs (vgl. Williams et al. 2008: 999. Daher befasst sich auch die Mehrheit der vorliegenden Studien mit eben diesen Spielen. Neue Formen von MMO(Gs können jedoch zu ebenso neuartigen Spielerfahrungen führen und damit unterschiedliche Nutzungsmotive befriedigen (vgl. Seifert/Jöckel 2008: 309 und folglich zu einem gänzlich anderen Spielerleben führen. Während im Mainstream die kooperativen Spielerbeziehungen überwiegen, dominiert in Darkfall Online der soziale Wettbewerb. Der von Williams et al. 2008 verwendete Fragebogen diente als Rohling für die Kreation eines für die speziellen Anforderungen adaptierten Erhebungstools zur Erforschung der Spielertypologie und der Motive der Darkfall-Online-SpielerInnen. Die in der Onlinebefragung (N = 506 gesammelten Daten belegen, dass sich sowohl die Spielerdemographie, als auch die Motive der Spieler von den Mainstream MMOs unterscheiden. Zudem konnten realweltliche Eigenschaften der Spieler als signifikante Einflussfaktoren für die Spielzuwendung identifiziert werden.

  8. Biodegradation of diesel/biodiesel blends in saturated sand microcosms

    DEFF Research Database (Denmark)

    Lisiecki, Piotr; Chrzanowski, Łukasz; Szulc, Alicja;

    2014-01-01

    The aim of the study was to evaluate the biodegradation extent of both aromatic and aliphatic hydrocarbon fractions in saturated sandy microcosm spiked with diesel/biodiesel blends (D, B10, B20, B30, B40, B50, B60, B70, B80, B90 and B100, where D is commercial petroleum diesel fuel and B is...... commercial biodiesel blend) augmented with a bacterial consortium of petroleum degraders. The biodegradation kinetics for blends were evaluated based on measuring the amount of emitted CO2 after 578 days. Subsequently, the residual aromatic and aliphatic fractions were separated and determined by employing...... GC-FID and GC _ GC–TOF-MS. Additionally, the influence of biodiesel-amendment on the community dynamics was assessed based on the results of real-time PCR analyzes. Our results suggest that the biodegradation extents of both aliphatic and aromatic hydrocarbon were uninfluenced by the addition of...

  9. Disposition and safety of inhaled biodegradable nanomedicines: Opportunities and challenges.

    Science.gov (United States)

    Haque, Shadabul; Whittaker, Michael R; McIntosh, Michelle P; Pouton, Colin W; Kaminskas, Lisa M

    2016-08-01

    The inhaled delivery of nanomedicines can provide a novel, non-invasive therapeutic strategy for the more localised treatment of lung-resident diseases and potentially also enable the systemic delivery of therapeutics that are otherwise administered via injection alone. However, the clinical translation of inhalable nanomedicine is being hampered by our lack of understanding about their disposition and clearance from the lungs. This review provides a comprehensive overview of the biodegradable nanomaterials that are currently being explored as inhalable drug delivery systems and our current understanding of their disposition within, and clearance from the lungs. The safety of biodegradable nanomaterials in the lungs is discussed and latest updates are provided on the impact of inflammation on the pulmonary pharmacokinetics of inhaled nanomaterials. Overall, the review provides an in-depth and critical assessment of the lung clearance mechanisms for inhaled biodegradable nanomedicines and highlights the opportunities and challenges for their translation into the clinic. PMID:27033834

  10. Modeling Biodegradation Kinetics on Benzene and Toluene and Their Mixture

    Directory of Open Access Journals (Sweden)

    Aparecido N. Módenes

    2007-10-01

    Full Text Available The objective of this work was to model the biodegradation kinetics of toxic compounds toluene and benzene as pure substrates and in a mixture. As a control, Monod and Andrews models were used. To predict substrates interactions, more sophisticated models of inhibition and competition, and SKIP (sum kinetics interactions parameters model were applied. The models evaluation was performed based on the experimental data from Pseudomonas putida F1 activities published in the literature. In parameter identification procedure, the global method of particle swarm optimization (PSO was applied. The simulation results show that the better description of the biodegradation process of pure toxic substrate can be achieved by Andrews' model. The biodegradation process of a mixture of toxic substrates is modeled the best when modified competitive inhibition and SKIP models are used. The developed software can be used as a toolbox of a kinetics model catalogue of industrial wastewater treatment for process design and optimization.

  11. QSBR Study on the Anaerobic Biodegradation of Chlorophenols

    Institute of Scientific and Technical Information of China (English)

    YANG Da-Sen; DAI You-Zhi; LI Jian-Hua; ZHU Fei

    2006-01-01

    18 Physicochemical and quantum chemical parameters of 12 kinds of chlorophenols are calculated in this paper. QSBR (quantitative structure-biodegradability relationship) study is performed using simca statistical software by PLS regression analysis method on anaerobic biodegradation data (logKb), and the QSBR model is developed with favorable prediction. The model shows that the size and energy of the molecule are the dominant factors affecting the anaerobic biodegradation of chlorophenols. And the degradation rate constants (logKb) increase with the increase of core-core repulsion (CCR), average molecular polarizability (α), total surface area (TSA), heat of formation (HOF) and total energy (TE), while decrease with the increase of molecular connectivity index (1XV), relative molecular mass (Mw) and electronic energy (EE).

  12. BIODEGRADABILITY AND MECHANICAL BEHAVIOUR OF SUGAR PALM STARCH BASED BIOPOLYMER

    Directory of Open Access Journals (Sweden)

    J. Sahari

    2014-01-01

    Full Text Available A new Sugar Palm Starch (SPS based biopolymer was successfully developed using glycerol as plasticizer. The effect of glycerol concentration (viz., 15, 20, 30 and 40 by weight percent to the mechanical properties of plasticized SPS biopolymer was investigated. From this investigation, it was found that the 30% glycerol concentrated biopolymer showed the highest flexural strength and impact with the value of 0.13 MPa and 6.13 kJ/m2 respectively. Later, the above 30% glycerol biopolymer was undergone through weathering and biodegradation test. The biodegradability test showed 78.09% of tensile strength lost after 72 h of weathering testing period. Meanwhile, the weight loss (% of the same biopolymer was 63.58% after 72 h of biodegradation test.

  13. Molecular Design of Synthetic Biodegradable Polymers as Cell Scaffold Materials

    Institute of Scientific and Technical Information of China (English)

    WANG Shen-guo; WAN Yu-qing; CAI Qing; HE Bin; CHEN Wen-na

    2004-01-01

    Poly(lactic acid) and its copolymers are regarded as the most useful biomaterials. The good biocompatibility, biodegradability and mechanical properties of them make the synthetic biodegradable polymers have primary application to tissue engineering. The advantages and disadvantages of the synthetic biodegradable polymers as cell scaffold materials are evaluated. This article reviews the modification of polylactide-family aliphatic polymers to improve the cell affinity when the polymers are used as cell scaffolds. We have developed four main approaches: to modify polyester cell scaffolds in combination of plasma treating and collagen coating; to introduce hydrophilic segments into aliphatic polyester backbones; to introduce pendant functional groups into polyester chains; to modify polyester with dextran. The results of the cell cultures prove that the approaches mentioned above have improved the cell affinity of the polyesters and have modulated cell function such as adhesion, proliferation and migration.

  14. Preliminary study of biodegradation of AZ31B magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    REN Yibin; HUANG Jingjing; ZHANG Bingchun; YANG Ke

    2007-01-01

    Magnesium alloys are potential to be developed as a new type of biodegradable implant material by use of their active corrosion behavior.Both in vitro and in vivo biodegradation properties of an AZ31B magnesium alloy were investigated in this work.The results showed that AZ31B alloy has a proper degradation rate and much lower hydrogen release in Hank's solution,with a degradation rate of about 0.3 mm/year and hydrogen release below 0.15mL/cm2.The animal implantation test showed that the AZ31B alloy could slowly biodegrade in femur of the rabbit and form calcium phosphate around the alloy sample,with the Ca/P ratio close to the natural bone.

  15. Modeling cutinase enzyme regulation in polyethylene terepthalate plastic biodegradation

    Science.gov (United States)

    Apri, M.; Silmi, M.; Heryanto, T. E.; Moeis, M. R.

    2016-04-01

    PET (Polyethylene terephthalate) is a plastic material that is commonly used in our daily life. The high production of PET and others plastics that can be up to three hundred million tons per year, is not matched by its degradation rate and hence leads to environmental pollution. To overcome this problem, we develop a biodegradation system. This system utilizes LC Cutinase enzyme produced by engineered escherichia coli bacteria to degrade PET. To make the system works efficaciously, it is important to understand the mechanism underlying its enzyme regulation. Therefore, we construct a mathematical model to describe the regulation of LC Cutinase production. The stability of the model is analyzed. We show that the designated biodegradation system can give an oscillatory behavior that is very important to control the amount of inclusion body (the miss-folded proteins that reduce the efficiency of the biodegradation system).

  16. Des plants de merisiers issus des vergers à graines disponibles !

    OpenAIRE

    Dufour, Jean; Santi, Frédérique; Migeot, Jonathan; Rondouin, Michel; Le Bouler, Hervé

    2012-01-01

    Les composants des vergers à graines Cabrerets et Avessac sont de bonne qualité génétique. Cependant, il faut les planter à 300-400 plants/ha en forêt, et 100 plants/ha en agroforesterie, pour faire face aux aléas des recombinaisons génétiques et aux problèmes environnementaux. Un suivi en taille de formation et élagage régulier permettra d’en tirer un bénéfice financier intéressant. La valeur locale des produits issus de ces vergers sera évaluée grâce à la « sélection participative »....

  17. Exploration et gestion des connaissances des ressources en IHM

    OpenAIRE

    André, Fabien; Artignan, Guillaume; Cordeil, Maxime; Hoarau, Raphaël; Vo, Dong-Bach

    2010-01-01

    Nous présentons dans l' article le résultat d'un travail réalisé à l'école de Printemps 2010 de l'AFIHM. L'analyse des activités liées à la réalisation d' un état de l'art nous montre qu'une des tâches les plus compliquées est la familiarisation avec un nouveau domaine. Pour outiller cette activité, nous présentons des pistes de réflexion basées sur une analogie avec la mémoire humaine.

  18. La mousson, pluie des agriculteurs et vent des marins

    OpenAIRE

    Aubaile-Sallenave, Françoise

    2014-01-01

    La mousson, c’est un mot arabe ayant une origine et une histoire propre. Ce sont aussi des vents et des courants marins qui vont de l’océan Indien aux mers de Chine et du Japon. C’est une zone de mouvements intenses mettant en contact des populations très diverses.La mousson a facilité depuis fort longtemps les voyages est - ouest (Chine vers Asie du sud-est et Inde) et ouest-est (Arabie vers Inde, Asie du sud-est et Chine), voyages qui donnent accès aux îles et presqu’îles de l’Asie du sud-e...

  19. Des arbres et des herbes aux marges du Sahara

    OpenAIRE

    Bernus, Edmond

    1992-01-01

    Le Sahara possède une végétation qui est d'autant plus précieuse pour ses habitants qu'elle est rare. Les herbes, prairies d'"éphémères" dans les zones aux pluies les plus aléatoires, ou vivaces et annuelles plus régulières, fournissent un fourrage très recherché. Dans les marges méridionales des herbes permettent des ramassages de graines qui donnent aux nomades des nourritures appréciées. Mil, sorgho et riz poussent à l'état spontané : les deux premiers ont été domestiqués dans cette région...

  20. Evolution des nages et théorie des jeux

    OpenAIRE

    Collard, Luc

    2011-01-01

    Nous nous servons de la Théorie des jeux pour formaliser une situation problématique observée en natation sportive lors de Championnats d’Europe espacés de trente ans. Dans les épreuves de 100 m de Dos, Papillon et Nage libre, les nageurs de haut niveau nagent plus vite en immersion qu’en émersion. En petits bassins (25m), la règle des 15m permet aux nageurs de rester sous l'eau sur des distances supérieures aux distances nagées en surface. Pourtant, les experts n'utilisent pas cette option e...

  1. Current algebra; Algebre des courants

    Energy Technology Data Exchange (ETDEWEB)

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

    1967-07-01

    The first three chapters of these lecture notes are devoted to generalities concerning current algebra. The weak currents are defined, and their main properties given (V-A hypothesis, conserved vector current, selection rules, partially conserved axial current,...). The SU (3) x SU (3) algebra of Gell-Mann is introduced, and the general properties of the non-leptonic weak Hamiltonian are discussed. Chapters 4 to 9 are devoted to some important applications of the algebra. First one proves the Adler- Weisberger formula, in two different ways, by either the infinite momentum frame, or the near-by singularities method. In the others chapters, the latter method is the only one used. The following topics are successively dealt with: semi leptonic decays of K mesons and hyperons, Kroll- Ruderman theorem, non leptonic decays of K mesons and hyperons ( {delta}I = 1/2 rule), low energy theorems concerning processes with emission (or absorption) of a pion or a photon, super-convergence sum rules, and finally, neutrino reactions. (author) [French] La premiere partie de ce cours (trois premiers chapitres), traite des generalites concernant l'algebre de courants. Apres une definition rapide des courants faibles et un rappel de leurs proprietes (hypothese V-A, conservation du courant vecteur, regles de selection, courant axial partiellement conserve,...), l'on introduit l'algebre de Gell-Mann SU (3) x SU (3), et discute les proprietes generales de l'Hamiltonien faible non leptonique. Les chapitres IV a IX sont consacres a des applications importantes de l'algebre des courants. En premier lieu l'on demontre la formule de Adler et Weisberger, par deux methodes differentes, celle dite du repere de moment infini et celle des singularites proches. Cette derniere est seule utilisee dans la suite. Puis, l'on traite successivement les problemes suivants: desintegrations semi-leptoniques des mesons K et des hyperons, theoreme de Kroll

  2. Banque de Brevets : petits exercices avec résultats : théorie des poutres (résistance des matériaux), dynamique des structures, incertitudes, mathématiques, mécanique des solides déformables, modélisation des solides, mécanique des fluides, pédagogie par CRAIES et ceintures

    OpenAIRE

    Génevaux, Jean-Michel

    2015-01-01

    Petits exercices avec résultats : théorie des poutres (résistance des matériaux), dynamique des structures, incertitudes, mathématiques, mécanique des solides déformables, modélisation des solides, mécanique des fluides, pédagogie par CRAIES et ceintures

  3. Biodegradable polymers: emerging excipients for the pharmaceutical and medical device industries.

    OpenAIRE

    Bhavesh Patel; Subhashis Chakraborty

    2013-01-01

    Worldwide many researchers are exploring the potential use of biodegradable polymerics as carriers for a wide range of therapeutic applications. In the past two decades, considerable progress has been made in the development of biodegradable polymeric materials, mainly in the biomedical and pharmaceutical industries due to their versatility, biocompatibility and biodegradability properties. The present review focuses on the use of biodegradable polymers in various therapeutic areas like or...

  4. Biodegradability of poly(lactic-co-glycolic acid) after femtosecond laser irradiation

    OpenAIRE

    Akimichi Shibata; Shuhei Yada; Mitsuhiro Terakawa

    2016-01-01

    Biodegradation is a key property for biodegradable polymer-based tissue scaffolds because it can provide suitable space for cell growth as well as tailored sustainability depending on their role. Ultrashort pulsed lasers have been widely used for the precise processing of optically transparent materials, including biodegradable polymers. Here, we demonstrated the change in the biodegradation of a poly(lactic-co-glycolic acid) (PLGA) following irradiation with femtosecond laser pulses at diffe...

  5. Biotechnologie des archées

    OpenAIRE

    Querellou, Joel

    2010-01-01

    La majorité des enzymes utilisées dans l’industrie provient des bactéries et des levures. Mais les conditions extrêmes dans lesquelles se développent de nombreuses espèces d’archées font que leurs constituants cellulaires possèdent des propriétés et une stabilité propices à leur utilisation en biotechnologie.

  6. Enzymatic oxidative biodegradation of nanoparticles: Mechanisms, significance and applications.

    Science.gov (United States)

    Vlasova, Irina I; Kapralov, Alexandr A; Michael, Zachary P; Burkert, Seth C; Shurin, Michael R; Star, Alexander; Shvedova, Anna A; Kagan, Valerian E

    2016-05-15

    Biopersistence of carbon nanotubes, graphene oxide (GO) and several other types of carbonaceous nanomaterials is an essential determinant of their health effects. Successful biodegradation is one of the major factors defining the life span and biological responses to nanoparticles. Here, we review the role and contribution of different oxidative enzymes of inflammatory cells - myeloperoxidase, eosinophil peroxidase, lactoperoxidase, hemoglobin, and xanthine oxidase - to the reactions of nanoparticle biodegradation. We further focus on interactions of nanomaterials with hemoproteins dependent on the specific features of their physico-chemical and structural characteristics. Mechanistically, we highlight the significance of immobilized peroxidase reactive intermediates vs diffusible small molecule oxidants (hypochlorous and hypobromous acids) for the overall oxidative biodegradation process in neutrophils and eosinophils. We also accentuate the importance of peroxynitrite-driven pathways realized in macrophages via the engagement of NADPH oxidase- and NO synthase-triggered oxidative mechanisms. We consider possible involvement of oxidative machinery of other professional phagocytes such as microglial cells, myeloid-derived suppressor cells, in the context of biodegradation relevant to targeted drug delivery. We evaluate the importance of genetic factors and their manipulations for the enzymatic biodegradation in vivo. Finally, we emphasize a novel type of biodegradation realized via the activation of the "dormant" peroxidase activity of hemoproteins by the nano-surface. This is exemplified by the binding of GO to cyt c causing the unfolding and 'unmasking' of the peroxidase activity of the latter. We conclude with the strategies leading to safe by design carbonaceous nanoparticles with optimized characteristics for mechanism-based targeted delivery and regulatable life-span of drugs in circulation. PMID:26768553

  7. Biodegradation of concrete intended for their decontamination; Biodegradation de matrices cimentaires en vue de leur decontamination

    Energy Technology Data Exchange (ETDEWEB)

    Jestin, A

    2005-05-15

    The decontamination of sub-structural materials represents a stake of high importance because of the high volume generated. It is agreed then to propose efficient and effective processes. The process of bio-decontamination of the hydraulic binders leans on the mechanisms of biodegradation of concretes, phenomenon characterized in the 40's by an indirect attack of the material by acids stem from the microbial metabolism: sulphuric acid (produced by Thiobacillus), nitric acid (produced by Nitrosomonas and Nitrobacter) and organic acids (produced by fungi). The principle of the bio-decontamination process is to apply those microorganisms on the surface of the contaminated material, in order to damage its surface and to retrieve the radionuclides. One of the multiple approaches of the process is the use of a bio-gel that makes possible the micro-organisms application. (author)

  8. Neologismen des Lettischen anhand des schriftstellerischen Werkes von Zigmunds Skujins

    OpenAIRE

    Javojss, Skaidrite

    2010-01-01

    Untersuchung: Aus acht Werken des zeitgenössischen Schriftstellers Zigmunds Skujins wurden 500 lettische Wörter untersucht, die in den drei umfangreichsten lettischen Wörterbüchern nicht verzeichnet und somit möglicherweise Neologismen des Autors sind. Analysiert werden die Wortarten, die Komposita, die Herkunft der assimilierten Lehnwörter, orthographische und andere Varianten bereits lexikalisierter Wörter, die Arten der Diminutivbildung und der Präfigierung. Außerdem werden Aussagen über d...

  9. Liste des abréviations et des sigles

    OpenAIRE

    2015-01-01

    AEF Afrique Équatoriale Française. AJCF Association Catholique de la Jeunesse Française. ALN Armée de Libération Nationale. AMGOT .Allied Military Government for Occupied Territories (administration militaire alliée des territoires occupés). AOF Afrique Occidentale Française. APEL Association des Parents d'élèves de l'École Libre. BBC British Broadcasting Corporation. CDL Comité Départemental de Libération. CDN Comité de Défense Nationale. CED Communauté Européenne de Défense. CEE Communauté ...

  10. Etude des termes diagnostiques des troubles du langage en orthophonie

    OpenAIRE

    Brin-Henry, Frédérique

    2014-01-01

    A travers une étude terminologique de la langue de l’orthophonie nous contribuons à la réflexion sur le lien entre les représentations des troubles du langage chez les orthophonistes et la réalité des dysfonctionnements langagiers observés chez les patients. L’annotation et l’extraction terminologique semi-automatique au sein de 436 comptes rendus de bilan orthophonique a permis d’élaborer une analyse syntactico-sémantique de 558 termes diagnostiques. L’examen de ces variations montre la prés...

  11. Des interactions biologiques à l’écologie des perturbations

    OpenAIRE

    Ganteaume, A.

    2014-01-01

    / Ce mémoire d'HDR présente mes activités de recherche depuis mon doctorat jusqu’à aujourd’hui. Elles couvrent plusieurs thématiques, toutes dans le domaine de l’écologie, tant au niveau terrestre que marin, dans le domaine animal ou végétal. Elles illustrent parfaitement ma capacité d’adaptation à travailler sur des sujets totalement différents, dans des environnements géographiques différents. Mes activités dans ces différents domaines sont présentées successivement...

  12. Effects of Biodegradation on Crude Oils from Karamay Oilfield

    Institute of Scientific and Technical Information of China (English)

    杨斌; 杨坚强; 等

    1989-01-01

    Studies of biological marker compou nds in five oil samples from a profile wherenormal crude oil,low condensate oil and heavy oil are produced in the Karamay Oilfield have been carried out with great empha-sis on the biodegradation-resisting capability of 13,17 secosteranes,8,14 secohopanes,gammacerane and carotenes.Based on these studies,a sequence of biodegradation-resisting intensities has been established for saturated hydrocarbon biomarkers in crude oils from the Karamay Oilfield.

  13. Development of biodegradable packing for agriculture in application

    OpenAIRE

    Mota, Carlos Miguel Costa

    2013-01-01

    Dissertação de mestrado integrado em Engenharia de Polímeros Este projeto nasce com a necessidade da indústria agrícola beneficiar das propriedades e funcionalidades dos polímeros biodegradáveis que se encontram em franca expansão no mercado global. Desta forma foram estudadas diversas formulações com base na matriz termoplástica biodegradável de PLA 3251D, e diversos aditivos orgânicos e inorgânicos como as borras de café, fibras de madeira e o adubo para, desta forma, desenvo...

  14. Biodegradation of mixture of VOC's in a biofilter

    Institute of Scientific and Technical Information of China (English)

    D. Arulneyam; T. Swaminathan

    2004-01-01

    Volatile organic compounds(VOC' s) in air have become major concem in recent years. Biodegradation of a mixture of ethanol and methanol vapor was evaluated in a laboratory biofilter with a bed of compost and polystyrene particles using an acclimated mixed culture. The continuous performance of the biofilter was studied with different proportion of ethanol and methanol at different initial concentration and flow rates. The result showed significant removal for both ethanol and methanol, which were composition dependent.The presence of either compound in the mixture inhibited the biodegradation of the other.

  15. Biodegraded and Polyurethane Drape-formed Urea Fertilizer

    Institute of Scientific and Technical Information of China (English)

    WANG Yong; LI Jian; CHEN Xiaoyao

    2005-01-01

    Natural water absorbent konjac flour participates in synthesizing biodegraded and polyurethane foamed drape, which is used to release urea slowly.The experimental results indicate that the slowly-releasing velocity of urea nitrogen and the degrading velocity of the drape can be controlled by regulating the thicknesses of drapes, the amount of konjac flour and the water content. In addition, the biodegradability of the drape was investigated by burying the specimens in earth afterwards,and results show this drape can be degraded naturally.

  16. Corrosion protection of mesoporous bioactive glass coating on biodegradable magnesium

    Science.gov (United States)

    Wang, Xiaojian; Wen, Cuie

    2014-06-01

    A mesoporous bioactive glass (MBG) coating was synthesized and coated on pure Mg substrate using a sol-gel dip-coating method. The MBG coating uniformly covered the Mg substrate with a thickness of ˜1.5 μm. Electrochemical and immersion tests were performed in order to investigate the biodegradation performance of Mg with and without different surface coatings in simulated body fluids (SBF) at 37 °C. Results revealed that the MBG coated Mg displayed a significantly lower biodegradation rate, in comparison with normal bioactive glass (BG) coated and uncoated Mg samples.

  17. Effects of Biodegradation on the Distribution of Alkylcarbazoles in Crude Oils

    Institute of Scientific and Technical Information of China (English)

    ZHANG CHUNMING(张春明); MEI BOWEN(梅博文); STEVE R.LARTER; MARTIN P.KOOPMANS; XIAO QIANHUA(肖乾华)

    2002-01-01

    We have investigated the distributions of alkylcarbazoles in a series of crude oils with different biodegradation extents, in combination with biomarker parameters, stable carbon isotopic ratios and viscosities. The analyses showed that slight biodegradation has little effect on alkylcarbazoles. The concentrations of C0-, C1-, and C2-carbazoles seem to display a slight decrease with biodegradation through the moderately biodegraded stage, and an abrupt decrease to the heavily biodegraded stage. The relative concentrations of C0-, C1-, and C2-carbazoles do not show any apparent change in the non-heavily biodegraded stages, but through non-heavily biodegraded to heavily biodegraded stages, the percentages of C0- and C1-carbazoles decrease,and those of C2-carbazoles increase significantly, which may indicate that C2-carbazoles are more resistant to biodegradation than lower homologous species. As to C2-carbazole isomers,the relative concentrations of the pyrrolic N-H-shielded, pyrrolic N-H partially shielded and pyrrolic N-H-exposed isomers do not show any obvious variation in the non-heavily biodegraded oil, but there is an abrupt change through the mid-biodegraded stage to the heavily biodegraded stage.

  18. Fenton's reagent as a remediation process in water treatment: application to the degradation of polycyclic aromatic hydrocarbons in waters and sewage sludges; La reaction de fenton comme procede de rehabilitation dans le traitement des eaux: application a la degradation des hydrocarbures aromatiques polycycliques dans les eaux et les boues residuaires

    Energy Technology Data Exchange (ETDEWEB)

    Flotron, V.

    2004-05-15

    This study is related to the application of Fenton's reagent to remedy matrices contaminated by polycyclic aromatic hydrocarbons (PAHs). In aqueous solution, the choice of the reagent implementation is important, in order to generate enough radicals to oxidize pollutants. Degradation of the organic compounds is possible, but a large difference in reactivity is observed between 'alternant' and 'non-alternant' PAHs (with a five carbon atoms cycle). Besides, if a few specific precautions are omitted, the PAHs can sorb onto the flask inside surface, and therefore not undergo oxidation. The results on sewage sludges show that under certain conditions (high reagent concentrations), the pollutants can be oxidised although they are adsorbed. Moreover, it appears that the matrix itself plays an important role, as the iron oxides seem to be able to decompose hydrogen peroxide, and thus initiate Fenton reaction. Its application to contaminated soils and sediments is also possible. (author)

  19. Caractérisation des communautés procaryotiques impliquées dans la bioremédiation d'un sol pollué par des hydrocarbures et développement d'outils d'analyse à haut débit

    OpenAIRE

    Militon, Cécile

    2007-01-01

    Environmental ecosystems are sensitive to damage from human activities and there is an increasing need to develop better methods for removing pollutants from soils. The removal of pollutants or their transformation to less toxic products by bioremediation is a less invasive and expensive process than classical decontamination. However, the use and optimization of bioremediation treatments requires knowledge on the microbial communities directly and indirectly involved in the degradation of th...

  20. Mechanical characterization of commercial biodegradable plastic films

    Science.gov (United States)

    Vanstrom, Joseph R.

    Polylactic acid (PLA) is a biodegradable plastic that is relatively new compared to other plastics in use throughout industry. The material is produced by the polymerization of lactic acid which is produced by the fermentation of starches derived from renewable feedstocks such as corn. Polylactic acid can be manufactured to fit a wide variety of applications. This study details the mechanical and morphological properties of selected commercially available PLA film products. Testing was conducted at Iowa State University and in conjunction with the United States Department of Agriculture (USDA) BioPreferred ProgramRTM. Results acquired by Iowa State were compared to a similar study performed by the Cortec Corporation in 2006. The PLA films tested at Iowa State were acquired in 2009 and 2010. In addition to these two studies at ISU, the films that were acquired in 2009 were aged for a year in a controlled environment and then re-tested to determine effects of time (ageing) on the mechanical properties. All films displayed anisotropic properties which were confirmed by inspection of the films with polarized light. The mechanical testing of the films followed American Society for Testing and Materials (ASTM) standards. Mechanical characteristics included: tensile strength (ASTM D882), elongation of material at failure (ASTM D882), impact resistance (ASTM D1922), and tear resistance (ASTM D4272). The observed values amongst all the films ranged as followed: tensile strength 33.65--8.54 MPa; elongation at failure 1,665.1%--47.2%; tear resistance 3.61--0.46 N; and puncture resistance 2.22--0.28 J. There were significant differences between the observed data for a number of films and the reported data published by the Cortec Corp. In addition, there were significant differences between the newly acquired material from 2009 and 2010, as well as the newly acquired materials in 2009 and the aged 2009 materials, suggesting that ageing and manufacturing date had an effect on

  1. L’Internet des objets

    OpenAIRE

    Benghozi, Pierre-Jean; Bureau, Sylvain; Massit-Folléa, Françoise

    2012-01-01

    L’ « internet des objets » est une dimension majeure de l’internet du futur. Mais tout le monde ne s’accorde pas encore sur sa définition, ni sur la mesure de son importance économique ou des risques qu’il induit. L’étude de nombreux rapports prospectifs et l’observation des innovations d’ores et déjà engagées a permis de mettre en relief les incertitudes techniques, économiques et socio-politiques qui pèsent sur cette véritable mutation programmée de l’internet et de proposer une approche eu...

  2. Le labyrinthe des ayants droit

    OpenAIRE

    Jonassaint, Jean

    2014-01-01

    À partir d’une analyse des difficultés rencontrées ou posées pour consulter, reproduire ou diffuser (totalement ou partiellement) des documents écrits ou audio-visuels d’Aimé Césaire, de Saint-John Perse, Frankétienne et Boisrond-Tonnerre, qui sont archivés ou non, cet article appelle à la simplification et l’harmonisation des règles d’accès aux archives, et la mise en place d’un ensemble de procédures pour traiter avec les titulaires de droit d’auteur qui soit efficace et équitable pour tout...

  3. Sociohistoire des Black Studies Departments

    OpenAIRE

    Rolland-Diamond, Caroline

    2012-01-01

    Cet article examine les conditions historiques d’émergence des départements d’études noires dans les universités américaines à partir de l’année 1968 et les premiers défis que ces nouvelles structures rencontrèrent dans leur processus d’institutionnalisation. Plus précisément, il revient sur le contexte historique de l’arrivée de l’idéologie du black power sur les campus américains à la fin des années 1960 (conjonction des trois facteurs décisifs de la désillusion causée par les limites du mo...

  4. 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

    Directory of Open Access Journals (Sweden)

    Peneloux A.

    2006-11-01

    Full Text Available For oil and gas offshore production, any extension of the Multiphase Production Concept to more complex effluents under more difficult transport conditions, requests a better understanding and control of :(a the thermodynamic behaviour of water-hydrocarbon mixtures,(b the efficiency of various additives (or mixtures of additives, necessary for a safe, reliable and economical operation of the production and transport facilities. One of the main additives used for hydrate control being methanol, this paper deals specifically with its thermodynamic properties and includes:(a first, an exhaustive bibliography of experimental-data with the method used for the selection of a coherent and reliable data base,(b then, a comparison of the results obtained, after adjustement on the data base :- with various cubic and not-cubic equations of state : Peng-Robinson, Cubic-Chain-Of-Rotators (CCOR, Chain-Of-Rotators (COR,- as well as with equations of state including methanol association phenomena (Anderko model, Wenzel and Krop model,(c and finally, an empirical Bipolynomial equation of state which represents the methanol thermodynamic properties with a good accuracy. Pour la production d'hydrocarbures en mer, le concept de transport polyphasique sur longues distances des fluides de réservoir non traités sur le champ est appelé à se développer. Les raisons du succès de ce concept sont évidentes : - sécurité des personnes : strict minimum de personnel travaillant en mer, minimum de trajets par hélicoptères, minimum de trafic maritime ; - protection de l'environnement : aucun rejet d'hydrocarbures ni à l'atmosphère, ni à la mer; - coûts réduits pour le développement comme pour l'exploitation : minimum d'équipement en mer (têtes de puits, vannes multivoies, débitmètres triphasiques,. . . , d'où des coûts réduits de 30 à 50 % pour des champs marginaux qui pourraient rester commercialement inexploitables avec des schémas de d

  5. Sporadische Ataxieerkrankungen des Erwachsenen

    Directory of Open Access Journals (Sweden)

    Bürk K

    2015-01-01

    Full Text Available Krankheitsprozesse in Kleinhirn und/oder Rückenmark können zu einer chronisch progredienten Ataxie führen, die damit von vaskulären und raumfordernden Prozessen abzugrenzen ist. Neben den selteneren hereditären Formen finden sich sporadische Ataxieerkrankungen. Die sorgfältige Anamnese erlaubt häufig bereits die Diagnose einer physikalisch oder toxisch bedingten Ataxie. Weiterführende Labordiagnostik dient der Feststellung eines Vitaminmangels (Vitamin B1, B12 und E. Die Untersuchung des Liquors sollte immer erfolgen und dient dem Ausschluss eines entzündlichen Geschehens. Bei raschem Verlauf muss an die Möglichkeit einer paraneoplastischen Genese gedacht und eine ausführliche Tumorsuche angeschlossen werden. Zudem können verschiedene Infektionskrankheiten eine Ataxie auslösen (HIV, Neuroborreliose, Lues, neurotrope Viren. Nach Ausschluss einer hereditären und symptomatischen Ätiologie wird das Krankheitsbild bislang mangels weiterführender diagnostischer Optionen als idiopathische zerebelläre Ataxie („idiopathic late-onset cerebellar ataxia“ [ILOCA] bezeichnet. Die ILOCA kann im Verlauf in eine Multisystematrophie vom zerebellären Typ (MSA-C übergehen, die sich durch eine wesentlich günstigere Prognose als ihre striatonigrale Verlaufsform (MSA-P auszeichnet. Nur für einige wenige Ataxieerkrankungen existieren ursächliche oder symptomatische Therapieansätze; die Behandlung beschränkt sich daher in den meisten Fällen auf logopädische, physio- und ergotherapeutische Maßnahmen.

  6. Application d'une équation d'état à la simulation du comportement thermodynamique des fluides dans les gisements et dans les installations de surface Application of an Equation of State to Simulating the Thermodynamic Behaviour of Fluids in Reservoirs and Surface Installations

    Directory of Open Access Journals (Sweden)

    Jain C.

    2006-11-01

    Full Text Available La connaissance des propriétés thermodynamiques des fluides pétroliers, en particulier des masses volumiques et des coefficients d'équilibre liquide-vapeur, intervient à divers stades de la production : primaire, secondaire par in-jection de gaz (C02 ou hydrocarbures miscibles, vapeur d'eau, séparation, réseau de collecte et de transport. L'ampleur du domaine de pression et de température à l'intérieur duquel on a besoin de connaître les propriétés des huiles et des gaz à condensat, et le fait que la compo-sition d'ensemble des mélanges diphasiques ne cesse de varier au cours de leur déplacement soit dans les gisements, soit dans les installations d'exploitation, rendent mani-feste l'intérêt de pouvoir calculer ces propriétés, en évi-tant d'avoir recours à des travaux de laboratoire beaucoup trop importants. Pour résoudre ces problèmes, une nouvelle équation d'état appelée Redlich-Kwong Développée (RKD a été mise au point. Au cours de cet exposé, nous verrons que cette équation restitue les enveloppes diphasiques de l'équilibre liquide-vapeur avec une qualité au moins égale à celles des méthodes de Soave et de Peng-Robinson qui jouissent actuellement d'une grande notoriété. L'avantage de ce modèle sur ces dernières méthodes est l'évaluation simultanée des propriétés volumétriques des phases en présence avec une bonne précision, ce qui est d'une grande utilité pour l'application de ce modèle aux problèmes industriels. Knowing the thermodynamic properties of petroleum fluids, and in particular the density and liquid-vapor equilibrium coefficients, is important at different stages of production, i. e. primary production, secondary production by gas flooding (CO2 or miscible hydrocarbons, steam, separation, gathering network and transportation. The pressure and temperature range within which the oil and gas-condensate properties must be known coupled with the fact that the overall composition of

  7. Nachuntersuchungen zur Ausbildung des Wollens

    OpenAIRE

    Krüger, Hans-Peter

    2010-01-01

    Dükers Ergebnisse zur Wirkung von zwangsläufiger Arbeit bei wollensschwachen Vpn konnten wieder eingebracht werden. Die Variation des Versuchsgeräts ergab, daß das Gelingen dieser Untersuchungen wesentlich von der methodisch einzuführenden Unausweichlichkeit der Situation abhängt. Je weniger dies verwirklicht wird, desto geringer ist der Leistungsanstieg, um so mehr tritt die Person des Vls in den Vordergrund, um so schwerer fällt es den Vpn, die Leistungssteigerung der eigenen Person zu attr...

  8. L'Europe des camps

    OpenAIRE

    Belguendouz, Abdelkrim; Bietlot, Mathieu; Bigo, Didier; Fischer, Nicolas; GARCIA CASTRO, Antonia; Intrand, Caroline; migreurop,; Perrouty, Pierre-Arnaud; Ragazzi, Francesco; Rodier, Claire; Teule, Catherine; VALLUY1, Jérôme

    2005-01-01

    Les pays occidentaux développent une culture politique de séparation et d'opposition entre ceux qui peuvent circuler librement dans le monde et ceux pour qui cela est interdit. Elle porte d'ailleurs un nom : le visa Schengen. Cela se traduit par la prolifération de camps d'exilés, où sont enfermés de force des hommes venus en Europe pour y trouver refuge, et par la subordination de pays voisins réduits à la fonction répressive de gardien des frontières... The countries of the European Union, ...

  9. L’entretien des corps

    OpenAIRE

    Gaberel, Pascal; Ossipow, Laurence

    2012-01-01

    Nous analysons ici le rapport à l’alimentation d’une cohorte de 387 personnes en situation de pauvreté reconnue. Ces usagers genevois de l’aide sociale ont été interrogés par questionnaires et entretiens durant une étude à long terme. Après un examen des lois et règlements cadrant la nécessité alimentaire et d’autres sources d’information, nous explorerons la conception du bien manger des usagers. Nous la comparerons ensuite à leurs consommations hebdomadaires et aux activités alimentaires ré...

  10. Populationsdynamik des Cydia pomonella Granulovirus

    OpenAIRE

    Steineke, Susanne Barbara

    2004-01-01

    Das Cydia pomonella Granulovirus (CpGV, Fam. Baculoviridae) ist ein sehr virulentes und hoch spezifisches Pathogen des Apfelwicklers (Cydia pomonella), das seit mehreren Jahren in der Bundesrepublik Deutschland und anderen Ländern der EU als Insektizid zugelassen ist. Wie andere Baculoviren auch befällt es die Larven der Insekten und ist aufgrund seiner Selektivität für Nicht-Zielorganismen unbedenklich. In der Vergangenheit konzentrierte sich die Erforschung des CpGV auf Bereiche, die für di...

  11. Classification of 3 DES Supernovae with OzDES

    Science.gov (United States)

    Moller, A.; Tucker, B. E.; Yuan, F.; Lewis, G.; Lidman, C.; Macaulay, E.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Foley, R. J.; Pan, Y.-C.; Casas, R.; Castander, F. J.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.

    2016-02-01

    We report new spectroscopic classifications by OzDES of supernovae discovered by the Dark Energy Survey (ATEL #4668). The spectra (370-885nm) were obtained with the AAOmega Spectrograph (Saunders et al. 2004, SPIE, 5492, 389) and the 2dF fibre positioner at the Anglo-Australian Telescope (AAT).

  12. Entwicklung des RFID- Einsatzes in der Logistik

    OpenAIRE

    Fruth, A.; Reiser, M; Günthner, W.A.

    2011-01-01

    Die Studie "Entwicklung des RFID-Einsatzes in der Logistik" geht im Vergleich zu umfragebasierten Studien einen anderen Weg. Als Grundlage für empirische Untersuchungen wurden über 300 RFID-Projekte, die in den vergangenen Jahren durchgeführt wurden, anhand öffentlicher Informationen analysiert und auswertbar gemacht. Diese sind in der Wissensdatenbank des RFID-AZM abgelegt. Eine Analyse des so entstandenen Datensatzes erlaubt das Aufzeigen des Status Quo des RFID-Einsatzes unabhängig von der...

  13. Les Sphingidae, probables pollinisateurs des baobabs malgaches

    OpenAIRE

    Ryckewaert, Philippe; Razanamaro, Onja; Rasoamanana, Elysée; Rakotoarimihaja, Tantelinirina; Ramavovololona, Perle; Danthu, Pascal

    2011-01-01

    Des comparaisons phénologiques et morphologiques des f leurs des six espèces de baobabs, Adansonia spp., endémiques de Madagascar et une étude des insectes visiteurs de ces fleurs ont été menées in situ afin d'identifier les pollinisateurs possibles de ces arbres. Les baobabs malgaches sont regroupés en deux sections en fonction de la lon- gueur de l'androcée (tube pollinique plus filet des étamines) : les Longitubae, A. za, A. rubrostipa, A. madagascariensis et A. perrieri, dont l'androcée v...

  14. Molecular design of biodegradable polymers for tissue engineering

    Czech Academy of Sciences Publication Activity Database

    Rypáček, František; Kubies, Dana; Machová, Luďka; Proks, Vladimír; Popelka, Štěpán

    Myconos : Aegean Conferences, 2002. s. 75. [Symposium on Tissue Engineering Science : Critical Elements in the Research Development Continuum. 19.05.2002-23.05.2002, Myconos] R&D Projects: GA AV ČR IAA4050202 Institutional research plan: CEZ:AV0Z4050913 Keywords : biodegradable polymers * tissue engineering Subject RIV: CD - Macromolecular Chemistry

  15. Acute aquatic toxicity and biodegradation potential of biodiesel fuels

    International Nuclear Information System (INIS)

    Recent studies on the biodegradation potential and aquatic toxicity of biodiesel fuels are reviewed. Biodegradation data were obtained using the shaker flask method observing the appearance of CO2 and by observing the disappearance of test substance with gas chromatography. Additional BOD5 and COD data were obtained. The results indicate the ready biodegradability of biodiesel fuels as well as the enhanced co-metabolic biodegradation of biodiesel and petroleum diesel fuel mixtures. The study examined reference diesel, neat soy oil, neat rape oil, and the methyl and ethyl esters of these vegetable oils as well as various fuel blends. Acute toxicity tests on biodiesel fuels and blends were performed using Oncorhynchus mykiss (Rainbow Trout) in a static non-renewal system and in a proportional dilution flow replacement system. The study is intended to develop data on the acute aquatic toxicity of biodiesel fuels and blends under US EPA Good Laboratory Practice Standards. The test procedure is designed from the guidelines outlined in Methods for Measuring the Acute Toxicity of Effluents and Receiving Waters to Freshwater and Marine Organisms and the Fish Acute Aquatic Toxicity Test guideline used to develop aquatic toxicity data for substances subject to environmental effects test regulations under TSCA. The acute aquatic toxicity is estimated by an LC50, a lethal concentration effecting mortality in 50% of the test population

  16. Interspecific interactions in mixed microbial cultures in a biodegradation perspective

    Czech Academy of Sciences Publication Activity Database

    Mikesková, Hana; Novotný, Čeněk; Svobodová, Kateřina

    2012-01-01

    Roč. 95, č. 4 (2012), s. 861-870. ISSN 0175-7598 R&D Projects: GA AV ČR IAAX00200901 Institutional support: RVO:61388971 Keywords : Microbial consortia * Consortium development * Biodegradation Subject RIV: EE - Microbiology, Virology Impact factor: 3.689, year: 2012

  17. Biodegradable copolymers carrying cell-adhesion peptide sequences

    Czech Academy of Sciences Publication Activity Database

    Proks, Vladimír; Machová, Luďka; Popelka, Štěpán; Rypáček, František

    Antalya : Ankara University, Tissue Engineering and Biomaterials Laboratory, 2002. s. P-35. [International Symposium on Biomedical Science and Technology BIOMED /9./. 19.09.2002-22.09.2002, Antalya ] R&D Projects: GA AV ČR IAA4050202; GA MŠk LN00A065 Keywords : amphiphilic block copolymers * cell adhesion * biodegradable Subject RIV: CD - Macromolecular Chemistry

  18. The development and performance testing of a biodegradable scale inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, Julie; Fidoe, Steve; Jones, Chris

    2006-03-15

    The oil industry is currently facing severe restrictions concerning the discharge of oil field chemicals into the environment. Many commonly used materials in both topside and downhole applications are phased for substitution for use in the North Sea, and more will be identified. The development of biodegradable and low toxicity chemicals, which afford equal or improved efficacy, compared to conventional technology, available at a competitive price, is a current industry challenge. A range of biodegradable materials are increasingly available, however their limited performance can result in a restricted range of applications. This paper discusses the development and commercialization of a readily biodegradable scale inhibitor, ideal for use in topside applications. This material offers a broad spectrum of activity, notably efficiency against barium sulphate, calcium sulphate and calcium carbonate scales, in a range of water chemistries. A range of performance testing, compatibility, stability and OCNS dataset will be presented. Comparisons with commonly used chemicals have been made to identify the superior performance of this phosphate ester. This paper will discuss a scale inhibitor suitable for use in a variety of conditions which offers enhanced performance combined with a favourable biodegradation profile. This material is of great benefit to the industry, particularly in North Sea applications. (author) (tk)

  19. Effects of nitrogen source on crude oil biodegradation

    International Nuclear Information System (INIS)

    The effects of NH4Cl and KNO3 on biodegradation of light Arabian crude oil by an oil-degrading enrichment culture were studied in respirometers. In poorly buffered sea salts medium, the pH decreased dramatically in cultures that contained NH4Cl, but not in those supplied with KNO3. The ammonia-associated pH decline was severe enough to completely stop oil biodegradation as measured by oxygen uptake. Regular adjustment of the culture pH allowed oil biodegradation to proceed normally. A small amount of nitrate accumulated in all cultures that contained ammonia, but nitrification accounted for less than 5% of the acid that was observed. The nitrification inhibitor, nitrapyrin, had no effect on the production of nitrate or acid in ammonia-containing cultures. When the culture pH was controlled, either by regular adjustment of the culture pH or by supplying adequate buffering capacity in the growth medium, the rate and extent of oil biodegradation were similar in NH4Cl- and KNO3-containing cultures. The lag time was shorter in pH-controlled cultures supplied with ammonia than in nitrate-containing cultures. (author)

  20. Anaerobic biodegradation of spent sulphite liquor in a UASB reactor

    DEFF Research Database (Denmark)

    Jantsch, T.G.; Angelidaki, Irini; Schmidt, Jens Ejbye;

    2002-01-01

    Anaerobic biodegradation of fermented spent sulphite liquor, SSL, which is produced during the manufacture of sulphite pulp, was investigated. SSL contains a high concentration of lignin products in addition to hemicellulose and has a very high COD load (173 g COD l1). Batch experiments with...

  1. Pharmacokinetics and biodegradation performance of a hydroxypropyl chitosan derivative

    Science.gov (United States)

    Shao, Kai; Han, Baoqin; Dong, Wen; Song, Fulai; Liu, Weizhi; Liu, Wanshun

    2015-10-01

    Hydroxypropyl chitosan (HP-chitosan) has been shown to have promising applications in a wide range of areas due to its biocompatibility, biodegradability and various biological activities, especially in the biomedical and pharmaceutical fields. However, it is not yet known about its pharmacokinetics and biodegradation performance, which are crucial for its clinical applications. In order to lay a foundation for its further applications and exploitations, here we carried out fluorescence intensity and GPC analyses to determine the pharmacokinetics mode of fluorescein isothiocyanate-labeled HP-chitosan (FITC-HP-chitosan) and its biodegradability. The results showed that after intraperitoneal administration at a dose of 10 mg per rat, FITC-HP-chitosan could be absorbed rapidly and distributed to liver, kidney and spleen through blood. It was indicated that FITC-HP-chitosan could be utilized effectively, and 88.47% of the FITC-HP-chitosan could be excreted by urine within 11 days with a molecular weight less than 10 kDa. Moreover, our data indicated that there was an obvious degradation process occurred in liver (chitosan has excellent bioavailability and biodegradability, suggesting the potential applications of hydroxypropyl-modified chitosan as materials in drug delivery, tissue engineering and biomedical area.

  2. Biodegradable composite films from chitosan and chitin nanofibrils

    Czech Academy of Sciences Publication Activity Database

    Tishchenko, Galina; Kelnar, Ivan; Kaprálková, Ludmila; Pavlová, Eva; Kovářová, Jana; Mikešová, Jana; Brožová, Libuše; Strachota, Adam; Špírková, Milena; Kobera, Libor; Netopilík, Miloš; Bastl, Zdeněk; Carezzi, F.; Morganti, P.

    Pisa : University of Pisa, Department of Civil and Industrial Engineering, 2013, s. 58-59. [Workshop Green Chemistry and Nanotechnologies in Polymer Chemistry /4./. Pisa (IT), 04.09.2013-06.09.2013] EU Projects: European Commission(XE) 315233 - N-CHITOPACK Institutional support: RVO:61389013 ; RVO:61388955 Keywords : biodegradable films * chitosan chitin nanofibrils Subject RIV: CD - Macromolecular Chemistry

  3. Influence of saponins on the biodegradation of halogenated phenols.

    Science.gov (United States)

    Kaczorek, Ewa; Smułek, Wojciech; Zdarta, Agata; Sawczuk, Agata; Zgoła-Grześkowiak, Agnieszka

    2016-09-01

    Biotransformation of aromatic compounds is a challenge due to their low aqueous solubility and sorptive losses. The main obstacle in this process is binding of organic pollutants to the microbial cell surface. To overcome these, we applied saponins from plant extract to the microbial culture, to increase pollutants solubility and enhance diffusive massive transfer. This study investigated the efficiency of Quillaja saponaria and Sapindus mukorossi saponins-rich extracts on biodegradation of halogenated phenols by Raoultella planticola WS2 and Pseudomonas sp. OS2, as an effect of cell surface modification of tested strains. Both strains display changes in inner membrane permeability and cell surface hydrophobicity in the presence of saponins during the process of halogenated phenols biotransformation. This allows them to more efficient pollutants removal from the environment. However, only in case of the Pseudomonas sp. OS2 the addition of surfactants to the culture improved effectiveness of bromo-, chloro- and fluorophenols biodegradation. Also introduction of surfactant allowed higher biodegradability of halogenated phenols and can shorten the process. Therefore this suggests that usage of plant saponins can indicate more successful halogenated phenols biodegradation for selected strains. PMID:27232205

  4. Application of a Biodegradable Lubricant in a Diesel Vehicle

    DEFF Research Database (Denmark)

    Schramm, Jesper

    2003-01-01

    , NOx, THC, PM, lubricant-SOF and PAH from one diesel and one gasoline type vehicle using biodegradable lubricants and conventional lubricants. This paper describes the results of the experiments with the diesel type vehicle only. Lubricant consumption and fuel consumption are other important parameters...

  5. Physical, mechanical, and biodegradable properties of meranti wood polymer composites

    International Nuclear Information System (INIS)

    Highlights: • In-situ polymerization and solution casting method used to manufacture WPC. • In-situ WPC exhibited better properties compared to pure wood, 5% WPC and 20% WPC. • Lowest water absorption and least biodegradability shown by In-situ wood. - Abstract: In-situ polymerization and solution casting techniques are two effective methods to manufacture wood polymer composites (WPCs). In this study, wood polymer composites (WPCs) were manufactured from meranti sapwood by solution casting and in-situ polymerization process using methyl methacrylate (MMA) and epoxy matrix respectively. Physical, mechanical, and morphological characterizations of fabricated WPCs were then carried out to analyse their properties. Morphological properties of composites samples were analyzed through scanning electron microscopy (SEM). The result reveals that in-situ wood composite exhibited better properties compared to pure wood, 5% WPC and 20% WPC. Moreover, in-situ WPC had lowest water absorption and least biodegraded. Conversely, pure wood shown moderate mechanical strength, high biodegradation and water absorption rate. In term of biodegradation, earth-medium brought more severe effect than water in deteriorating the properties of the specimens

  6. Biodegradation of oil refinery wastes under OPA and CERCLA

    Energy Technology Data Exchange (ETDEWEB)

    Gamblin, W.W.; Banipal, B.S.; Myers, J.M. [Ecology and Environment, Inc., Dallas, TX (United States)] [and others

    1995-12-31

    Land treatment of oil refinery wastes has been used as a disposal method for decades. More recently, numerous laboratory studies have been performed attempting to quantify degradation rates of more toxic polycyclic aromatic hydrocarbon compounds (PAHs). This paper discusses the results of the fullscale aerobic biodegradation operations using land treatment at the Macmillan Ring-Free Oil refining facility. The tiered feasibility approach of evaluating biodegradation as a treatment method to achieve site-specific cleanup criteria, including pilot biodegradation operations, is discussed in an earlier paper. Analytical results of biodegradation indicate that degradation rates observed in the laboratory can be met and exceeded under field conditions and that site-specific cleanup criteria can be attained within a proposed project time. Also prevented are degradation rates and half-lives for PAHs for which cleanup criteria have been established. PAH degradation rates and half-life values are determined and compared with the laboratory degradation rates and half-life values which used similar oil refinery wastes by other in investigators (API 1987).

  7. MICROORGANISMS’ SURFACE ACTIVE SUBSTANCES ROLE IN HYDROCARBONS BIODEGRADATION

    Directory of Open Access Journals (Sweden)

    Оlga Vasylchenko

    2012-09-01

    Full Text Available  Existing data and publications regarding oil, hydrocarbon biodegradation, metabolism, and bioremediation were analyzed. Search of hydrocarbon degrading bacteria which are producers of biosurfactants was provided, types of microbial surfactants and their physiological role were analyzed and ordered. The study of factors affecting the surface active properties of producers’ cultures was done.

  8. Biodegradable Metals for Cardiovascular Stent Application: Interests and New Opportunities

    Directory of Open Access Journals (Sweden)

    Maryam Moravej

    2011-06-01

    Full Text Available During the last decade, biodegradable metallic stents have been developed and investigated as alternatives for the currently-used permanent cardiovascular stents. Degradable metallic materials could potentially replace corrosion-resistant metals currently used for stent application as it has been shown that the role of stenting is temporary and limited to a period of 6–12 months after implantation during which arterial remodeling and healing occur. Although corrosion is generally considered as a failure in metallurgy, the corrodibility of certain metals can be an advantage for their application as degradable implants. The candidate materials for such application should have mechanical properties ideally close to those of 316L stainless steel which is the gold standard material for stent application in order to provide mechanical support to diseased arteries. Non-toxicity of the metal itself and its degradation products is another requirement as the material is absorbed by blood and cells. Based on the mentioned requirements, iron-based and magnesium-based alloys have been the investigated candidates for biodegradable stents. This article reviews the recent developments in the design and evaluation of metallic materials for biodegradable stents. It also introduces the new metallurgical processes which could be applied for the production of metallic biodegradable stents and their effect on the properties of the produced metals.

  9. Resonant infrared pulsed laser deposition of thin biodegradable polymer films

    DEFF Research Database (Denmark)

    Bubb, D.M.; Toftmann, B.; Haglund Jr., R.F.;

    2002-01-01

    Thin films of the biodegradable polymer poly(DL-lactide-co-glycolide) (PLGA) were deposited using resonant infrared pulsed laser deposition (RIR-PLD). The output of a free-electron laser was focused onto a solid target of the polymer, and the films were deposited using 2.90 (resonant with O...

  10. Biodegradable thermosensitive polymers: synthesis, characterization and drug delivery applications

    NARCIS (Netherlands)

    Soga, Osamu

    2006-01-01

    The aim of the research described in this Thesis is to design polymeric micelles showing controlled instability due to "hydrophobic to hydrophilic" conversion of the core, and to demonstrate its utility as a drug delivery vehicle. For that purpose, a novel class of thermosensitive and biodegradable

  11. Biodegradable xylitol-based elastomers: In vivo behavior and biocompatibility

    NARCIS (Netherlands)

    J.P. Bruggeman (Joost); C.J. Bettinger (Christopher); R.S. Langer (Robert)

    2010-01-01

    textabstractBiodegradable elastomers based on polycondensation reactions of xylitol with sebacic acid, referred to as poly(xylitol sebacate) (PXS) elastomers have recently been developed. We describe the in vivo behavior of PXS elastomers. Four PXS elastomers were synthesized, characterized, and com

  12. Bio-Based Polymers with Potential for Biodegradability

    Directory of Open Access Journals (Sweden)

    Thomas F. Garrison

    2016-07-01

    Full Text Available A variety of renewable starting materials, such as sugars and polysaccharides, vegetable oils, lignin, pine resin derivatives, and proteins, have so far been investigated for the preparation of bio-based polymers. Among the various sources of bio-based feedstock, vegetable oils are one of the most widely used starting materials in the polymer industry due to their easy availability, low toxicity, and relative low cost. Another bio-based plastic of great interest is poly(lactic acid (PLA, widely used in multiple commercial applications nowadays. There is an intrinsic expectation that bio-based polymers are also biodegradable, but in reality there is no guarantee that polymers prepared from biorenewable feedstock exhibit significant or relevant biodegradability. Biodegradability studies are therefore crucial in order to assess the long-term environmental impact of such materials. This review presents a brief overview of the different classes of bio-based polymers, with a strong focus on vegetable oil-derived resins and PLA. An entire section is dedicated to a discussion of the literature addressing the biodegradability of bio-based polymers.

  13. Anaerobic Biodegradation of Pristane by Nitrate Reducing Bacteria

    Science.gov (United States)

    Dawson, K. S.; Freeman, K. H.; Macalady, J. L.

    2007-12-01

    In recent sediments, microbial biodegradation provides a control on the long-term preservation of organic matter, through the preferential loss of certain biomolecules and the alteration and concentration of other more recalcitrant molecules. Biodegradation of hydrocarbons derived from membrane lipids, has been demonstrated by both aerobic and strictly anaerobic culturing experiments. The isoprenoid pristane, once considered stable under anaerobic conditions, is in fact degraded by a denitrifying microcosm (BREGNARD et al., 1997) and a methanogenic, sulphate-reducing enrichment culture (GROSSI, 2000). We recently demonstrated pristane biodegradation and accompanying loss of nitrate by an activated sludge isolate. The measured nitrate consumption accounts for a 7.1 +/- 0.4 mg loss of pristane, 4.74% of the initial substrate, in 181 days, assuming pristane conversion to CO2. We have characterized the microorganisms active in the biodegradation process, through the creation of a 16S rDNA clone library, as well as fluorescence in situ hybridization (FISH). Experiments are in progress to enrich cultures of sulfate reducing bacteria that utilize pristane as a sole carbon source and to characterize reaction mechanisms in pristane-oxidizing pathways.

  14. Study on the Synthesis and Biodegradation of Aliphatic Polyester

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    An aliphatic polyester, poly(hexalene adipate) (PHA) and an aliphatic copolyester, poly (hexalene adipate succinate) (PHAS) were synthesized by direct condensation of corresponding binary acid and binary alcohol in the presence of a catalyst, p-toluene sulfonic acid. The biodegradation of these polyesters were studied in the laboratory by enzyme attack and outdoor soil burial. The results show that these polyesters have good biodegradability and the copolyester PHAS, even displayed a better biodegradability than the polyester PHA. In the presence of Penicillium chrysogenum the weight loss reached 18.3% for the PHAS (film thickness 1.0 mm)and 9.1% for the PHA (film thickness 1.0 mm) after 28 days. Outdoor soil burial tests indicate that these polyesters also have good biodegradability in natural conditions. The weight loss reached 14.2% for PHAS (film thickness 0.1 mm) and 6.7% for PHA (film thickness 0.1mm) after burying in soil for 36 days.

  15. Biodegradable polyurethanes for short-term outdoor usage

    Czech Academy of Sciences Publication Activity Database

    Kredatusová, Jana; Beneš, Hynek; Gawelczyk, Alexandra; Horák, Pavel; Kruliš, Zdeněk; Kobetičová, K.

    Cracow : Fampur A. Przekurat, Cracow University of Technology, Faculty of Chemical Engineering and Technology, 2015, P12. [Polyurethanes 2015 - cooperation for innovation . Kraków (PL), 09.09.2015-11.09.2015] R&D Projects: GA TA ČR(CZ) TA04020853 Institutional support: RVO:61389013 Keywords : polyurethane * biodegradable Subject RIV: CD - Macromolecular Chemistry

  16. Review on Chlorobenzoic Acids Biodegradation and Their Environmental Impacts

    Institute of Scientific and Technical Information of China (English)

    LuWenming; QiYun; ZhaoLin; TanXin

    2005-01-01

    Chlorobenzoic Acids are toxic organic compounds largely distributed in soils and sediments. They can be degraded to various products by microorgans. This paper is a review of the literature on biodegradability of the chlorobenzoic acids. The degradation pathways, degradation genes, role of transposable elements, and construction of strains are discussed. A brief introduction is given on the environmental impacts and the pollution control.

  17. Ecotoxicity and biodegradability of new brominated flame retardants: A review

    Czech Academy of Sciences Publication Activity Database

    Ezechiáš, Martin; Covino, Stefano; Cajthaml, Tomáš

    2014-01-01

    Roč. 110, č. 2 (2014), s. 153-167. ISSN 0147-6513 R&D Projects: GA MŠk(CZ) EE2.3.30.0003; GA TA ČR TE01020218 Institutional support: RVO:61388971 Keywords : Ecotoxicity * brominated flame retardants * biodegradation * review Subject RIV: EE - Microbiology, Virology Impact factor: 2.762, year: 2014

  18. Biodegradation of Lignocelluloses in Sewage Sludge Composting and Vermicomposting

    Directory of Open Access Journals (Sweden)

    Hosein Alidadi

    2012-08-01

    Full Text Available Please cite this article as: Alidadi H, Najafpour AA, Vafaee A, Parvaresh A, Peiravi R. Biodegradation of lignocelluloses in sewage sludge composting and vermicomposting. Arch Hyg Sci 2012;1(1:1-5.   Aims of the Study: The aim of this study was to determine the amount of lignin degradation and biodegradation of organic matter and change of biomass under compost and vermicomposting of sewage sludge. Materials & Methods: Sawdust was added to sewage sludge at 1:3 weight bases to Carbon to Nitrogen ratio of 25:1 for composting or vermicomposting. Lignin and volatile solids were determined at different periods, of 0, 10, 30, 40 and 60 days of composting or vermicomposting period to determine the biodegradation of lignocellulose to lignin. Results were expressed as mean of two replicates and the comparisons among means were made using the least significant difference test calculated (p <0.05. Results: After 60 days of experiment period, the initial lignin increased from 3.46% to 4.48% for compost and 3.46% to 5.27% for vermicompost. Biodegradation of lignocellulose was very slow in compost and vermicompost processes. Vermicomposting is a much faster process than compost to convert lignocellulose to lignin (p <0.05. Conclusions: The organic matter losses in sewage sludge composting and vermicomposting are due to the degradation of the lignin fractions. By increasing compost age, the amount of volatile solids will decrease.

  19. Diesel Pollution Biodegradation: Synergetic Effect of Mycobacterium and Filamentous Fungi

    Institute of Scientific and Technical Information of China (English)

    YOU-QING LI; HONG-FANG LIU; ZHEN-LE TIAN; LI-HUA ZHU; YIN-GHUI WU; HE-QING TANG

    2008-01-01

    Objective To biodegrade the diesel pollution in aqueous solution inoculated with Mycobacterium and filamentous fungi.Methods Bacteria sampled from petroleum hydrocarbons contaminated sites in Karamay Oilfield were isolated and identified as Mycobacterium hyalinum (MH) and cladosporium. Spectrophotometry and gas chromatography (GC) were used to analyze of the residual concentrations of diesel oil and its biodegradation products. Results From the GC data, the values of apparent biodegradation ratio of the bacterial strain MH to diesel oil were close to those obtained in the control experiments. Moreover, the number of MH did not increase with degradation time. However, by using n-octadecane instead of diesel oil, the real biotic degradation ratio increased to 20.9% over 5 days of degradation. Cladosporium strongly biodegraded diesel oil with a real degradation ratio of up to 34% after 5 days treatment. When the two strains were used simultaneously, a significant synergistic effect between them resulted in almost cornplete degradation of diesel off, achieving a total diesel removal of 99% over 5 days of treatment, in which one part of about 80% and another part of about 19% were attributed to biotic and abiotic processes, respectively. Conclusion The observed synergistic effect was closely related to the aromatics-degrading ability of Cladosporium, which favored the growth of MH and promoted the bioavailability of diesel oil.

  20. Artificial biodegradable materials for tissue engineering: synthesis and biomimetic modification

    Czech Academy of Sciences Publication Activity Database

    Kotelnikov, Ilya; Pop-Georgievski, Ognen; Novotná, Katarína; Kučka, Jan; Bačáková, Lucie; Proks, Vladimír; Rypáček, František

    Prague : Institute of Macromolecular Chemistry AS CR, 2013. L22. ISBN 978-80-85009-76-7. [Workshop "Career in Polymers" /5./. 12.07.2013-13.07.2013, Prague] Institutional support: RVO:61389013 ; RVO:67985823 Keywords : tissue engineering * biodegradable materials Subject RIV: CD - Macromolecular Chemistry