Littérature scientifique sur le sujet « Composés traces »
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Articles de revues sur le sujet "Composés traces"
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Ahronian, Céline, et Henri Béjoint. « Les noms composés anglais et français du domaine d’Internet : une radiographie bilingue ». Meta 53, no 3 (6 novembre 2008) : 648–66. http://dx.doi.org/10.7202/019245ar.
Texte intégralRésumé :
Résumé Cet article se propose d’étudier le lexique d’un domaine de spécialité, Internet, qui présente la particularité de n’être pas réservé à un groupe d’experts. Les termes apparaissant quasi exclusivement en langue anglaise, la question centrale est de savoir comment se traduit l’influence de l’anglais sur la terminologie du français, langue cible. Pour apporter des éléments de réponse, nous avons examiné les noms composés, qui sont particulièrement nombreux dans ce domaine. Après avoir dressé le profil morphosyntaxique des termes collectés dans notre corpus à travers l’étude de leurs structures compositionnelles, y compris la pseudo-confixation, nous avons tracé leur portrait sémantique avec une analyse de la centricité et des relations sémantiques entre leurs éléments. Notre conclusion est que le lexique français d’Internet conserve des traces de l’origine anglaise de nombreux termes mais que le nombre d’emprunts est faible.
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CHATELET, A., A. FOURNIER, S. JURJANZ, S. LERCH, H. TOUSSAINT, M. DELANNOY, C. FEIDT et G. RYCHEN. « L’épandage de matières fertilisantes d’origine résiduaire sur les prairies comporte-t-il des risques en termes de transfert de polluants organiques et inorganiques vers la chaîne alimentaire ? » INRA Productions Animales 28, no 5 (14 janvier 2020) : 383–98. http://dx.doi.org/10.20870/productions-animales.2015.28.5.3041.
Texte intégralRésumé :
L’objectif de cet article est d’identifier les points de vigilance relatifs aux transferts de polluants inorganiques ou organiques vers les animaux d’élevage via l’ingestion de sol, de plantes, d’eau ou encore de pédofaune, consécutivement à l’épandage de MAtières Fertilisantes d’Origine Résiduaire (MAFOR) sur les prairies. Cette identification consiste à prendre en compte simultanément les quantités de polluants ingérées (quantité de matrice ingérée × concentration du polluant dans cette matrice), la fraction biodisponible et le devenir des polluants au sein de l’organisme. Les études réalisées en conditions de terrain et qui renseignent l’ensemble des données nécessaires pour estimer l’impact des MAFOR épandues sur prairies sont rares et peu conclusives. Elles reposent principalement sur l’application des boues de stations d’épuration sur des prairies et ne permettent pas de comparer l’impact des autres formes de MAFOR. Cependant, en prenant en compte l’ensemble des connaissances sur les transferts de polluants vers les produits animaux, il apparaît que les polluants organiques sont plus fortement absorbés que les Eléments Traces Métalliques (ETM). Seuls les composés peu biotransformés s’accumulent significativement dans les produits animaux. In fine, les polluants organiques se concentrent généralement dans les tissus et produits gras alors que les ETM se retrouvent préférentiellement dans les abats. Cependant, un manque manifeste de connaissances sur le devenir de contaminants organiques émergents (bromés, perfluorés, phtalates et paraffines) ou de certains ETM (vanadium et thallium) doit être signalé. De manière globale, les transferts de polluants organiques et inorganiques vers les produits animaux, suite à l’épandage de MAFOR sur les prairies, ne peuvent être exclus.
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Rolim, Nathiene Patrícia Ferreira Amaral, Ilda Antonieta Salata Toscano, Gil Dutra Furtado, Flávia Oliveira Paulino et Maria Cristina Crispim. « CREVETTICULTURE, SANTÉ PUBLIQUE ET ENVIRONNEMENT : SECURITE ALIMENTAIRE, SECURITE NUTRITIONNELLE ET DURABILITE DE L’ACTIVITE ». ENVIRONMENTAL SMOKE 2, no 1 (7 mai 2019) : 47–66. http://dx.doi.org/10.32435/envsmoke.20192147-66.
Texte intégralRésumé :
La présence humaine à proximité des écosystèmes aquatiques a entraîné la survenue d'impacts environnementaux affectant en particulier les zones de mangroves, d'apiquons et de talus. Parmi les activités humaines dans ces écosystèmes, on peut souligner que l’élevage de crevettes a de graves incidences sur l’environnement et est une préoccupation majeure pour la société, en particulier pour les crevettes cultivées. Le fait de proposer des rations commerciales de faible qualité et d’autres sources de contamination telles que des engrais, des pesticides, des algicides et d’autres substances utilisées dans les réservoirs de culture peut contribuer à la contamination de la crevette, en favorisant la bioaccumulation de métaux traces tels que le fer, cuivre,cobalt, manganèse, zinc et chrome, dont les métaux font souvent partie de leurs composés. L’accès à la santé est l’un des droits de l’homme fondamentaux garantis par la Constitution Fédérale Brésilienne de 1988, qui intègre la notion élargie de la santé dans le contexte de l’accès et de la promotion par l’État. Ladite Constitution fait également de la nourriture adéquate un droit fondamental de l'être humain, où la sécurité alimentaire et nutritionnelle concerne, entre autres, l'accès à la nourriture et sa consommation en quantité et avec des qualités suffisantes pour nourrir l'individu et prévenir la survenue de dommages à la santé de l'individu. De cette manière, la culture de crevettes marines doit également respecter les conditions légales en matière d’environnement et d’hygiène, car ces animaux doivent être exempts de tout contaminant, introduit accidentellement ou intentionnellement pour les nourrir ou les conserver, que la législation brésilienne n’a pas réglementée. Pour assurer la sécurité alimentaire et nutritionnelle, il est nécessaire de comprendre la relation intrinsèque que l’élevage de crevettes avec l’environnement, les changements apportés aux écosystèmes impliqués et la nécessité de prendre des mesures de gestion de l’environnement et de parvenir ainsi à la durabilité socio-environnementale de cette activité.
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Schindler, David W. « Geoscience of Climate and Energy 12. Water Quality Issues in the Oil Sands Region of the Lower Athabasca River, Alberta ». Geoscience Canada 40, no 3 (31 octobre 2013) : 202. http://dx.doi.org/10.12789/geocanj.2013.40.012.
Texte intégralRésumé :
I summarize the controversies about industrial pollutants in freshwaters near the oil sands industrial area of Alberta, the inadequacies in environmental monitoring that have led to widespread misconceptions, and recent attempts to correct the problems. Adequate data are available to show that mercury, other trace metals, and polycyclic aromatic compounds are being added by industry to the Athabasca river system and its watershed, although the relative contributions of industrial development and natural sources remain in question. Recent improvements in water monitoring by Environment Canada show promise of resolving the controversies, although independent governance for Canada’s and Alberta’s water monitoring programs in the lower Athabasca River will be necessary to rebuild public confidence in the data and their interpretation by government and industry. I document one success story in the Athabasca River: the elimination of dioxins from pulp mills in the mid-1990s has caused a consumption advisory for fish in the river to be repealed.SOMMAIREJe présente ci-dessous un résumé des controverses concernant les polluants industriels dans les eaux douces à proximité de la zone industrielle des sables bitumineux de l'Alberta, des lacunes dans la surveillance des milieux de vie à l’origine d’idées fausses répandues, et de récentes tentatives visant à corriger les problèmes. Des données adéquates démontrent que l’industrie ajoute du mercure et d'autres métaux traces ainsi que des composés aromatiques polycycliques dans le système fluvial de la rivière Athabasca et dans son bassin versant, bien que les contributions relatives provenant de ces activités industrielles et de sources naturelles demeurent toujours en litige. De récentes améliorations apportées au contrôle des eaux par Environnement Canada permettent d’espérer une résolution des controverses, mais l’application d’une gouvernance indépendante des programmes de contrôle de l'eau de l'Alberta du Canada dans la partie inférieure du fleuve Athabasca sera nécessaire pour rétablir la confiance de la population à l’égard des données présentées et de leur interprétation par le gouvernement et l'industrie. Je décrie l’histoire d’une intervention réussie dans la rivière Athabasca, soit l'élimination de dioxines provenant des usines de pâte du milieu des années 1990 et qui a abouti à l’abrogation d’un avis de limitation de la consommation de poisson dans la rivière.DOI: http://dx.doi.org/10.12789/geocanj.2013.40.012
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DE VALAIS, SILVINA. « Ichnotaxonomic revision of Ameghinichnus, a mammalian ichnogenus from the Middle Jurassic La Matilde Formation, Santa Cruz province, Argentina ». Zootaxa 2203, no 1 (19 août 2009) : 1–21. http://dx.doi.org/10.11646/zootaxa.2203.1.1.
Texte intégralRésumé :
The ichnological assemblage from the Estancia Laguna Manantiales, from the Middle Jurassic La Matilde Formation, Santa Cruz province, Argentina, is exceptional both in diversity and abundance. It is composed of mammal, dinosaur, invertebrate, and root traces. The most significant and abundant specimens are those assigned to the ichnogenus Ameghinichnus Casamiquela, 1961. This ichnogenus is revised and an emendation of its diagnosis is suggested. The inclusion of all the known specimens to the type ichnospecies, Ameghinichnus patagonicus Casamiquela, 1961, is challenged and some specimens are placed in a new ichnospecies, Ameghinichnus manantialensis isp. nov. Similar tracks from other ichnological localities worldwide were previously referred to Ameghinichnus, but only Eopentapodiscus (Ellenberger, 1970), from South Africa is considered as a junior synonym of Ameghinichnus. The ichnotaxobases used to classify tracks with mammalian affinities at ichnogeneric and ichnospecific levels are evaluated and re-assessed ichnotaxonomic criteria are proposed. Different criteria used to distinguish mammalian imprints from non-mammalian tracks are commented.
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Moore, Thomas R. « Tools of the trade : click-tracks and conductors ». Interdisciplinary Studies in Musicology, no 20 (31 décembre 2020) : 9–20. http://dx.doi.org/10.14746/ism.2020.20.1.
Texte intégralRésumé :
This essay will examine the manner in which composers and artistic directors have used conductors and click-tracks within the context of new music ensembles performing integrative concerts. The analyses and examples provided will rely for the most part on material gathered during in-depth interviews that I conducted with artistic directors, composers, conductors, and musicians, all of whom are professionally active in the new music field in Europe (and beyond). I will examine the application of both click-tracks and conductors and demonstrate that their implementation represents an active choice made by either the composer and/or artistic directors. Both click-tracks and conductors are viewed by the interviewees as potential tools with somewhat overlapping possibilities and capacities and their presence is no secondary phenomenon of the music. They become instead a means for the above actors to meet their objectives, be they artistic, pragmatic, technical, or otherwise.
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De Saussure, Louis. « Remarques sur l'usage futur du passé composé ». Travaux neuchâtelois de linguistique, no 51 (1 janvier 2011) : 45–60. http://dx.doi.org/10.26034/tranel.2011.2770.
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This paper attempts to identify the pragmatic constraints that license the use of the present perfect with a future time adverb in French, such as J'ai bientôt fini (lit. 'I have soon finished') or Dans une heure, le président est sorti de sa réunion (lit. 'In an hour, the president has exited from his meeting'). Previous studies have argued that only aspectual verbs are available in such constructions, and that a pragmatic notion of planification must be accessible to the interlocutors, hence utterances like Demain il a plu ('Tomorrow it has rained') or Demain Pierre a été heureux ('Tomorrow Pierre has been happy') are odd. The paper suggests that some of the concerned utterances are fine, despite their lack of agentivity, so long as that doesn't merely presuppose planification but rather serves to communicate that a particular attitude, or course of actions has to be adopted in the present from the perspective of the/a future state of affairs.
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Ashurov Ma’rufjon Abdumutalibovich. « The study of the life and creativity of yunus rajabi and the rich heritage he left to the uzbek nation. » International Journal on Integrated Education 3, no 12 (3 décembre 2020) : 40–43. http://dx.doi.org/10.31149/ijie.v3i12.909.
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This article looks at the life of Yunus Rajabi, People's Artist of Uzbekistan, laureate of the Republican State Prize, musician, hafiz and composer, multifaceted artist, academician. His life, his entry into the art of music, the lessons he learned from his family, the deep and bright traces in the history of twentieth-century Uzbek music, his contribution to the development of our modern music culture, as well as O He is one of the founders of the Union of Composers of Uzbekistan. given.
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Yap, Steven Y., Barbara Frias, Melissa C. Wren, Michael Schöll, Nick C. Fox, Erik Årstad, Tammaryn Lashley et Kerstin Sander. « Discriminatory ability of next-generation tau PET tracers for Alzheimer’s disease ». Brain 144, no 8 (20 mars 2021) : 2284–90. http://dx.doi.org/10.1093/brain/awab120.
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Abstract A next generation of tau PET tracers for the imaging of Alzheimer’s disease and other dementias has recently been developed. Whilst the new compounds have now entered clinical studies, there is limited information available to assess their suitability for clinical applications. Head-to-head comparisons are urgently needed to understand differences in the radiotracer binding profiles. We characterized the binding of the tau tracers PI2620, RO948, MK6240 and JNJ067 in human post-mortem brain tissue from a cohort of 25 dementia cases and age-matched controls using quantitative phosphorimaging with tritium-labelled radiotracers in conjunction with phospho-tau specific immunohistochemistry. The four radiotracers depicted tau inclusions composed of paired helical filaments with high specificity, both in cases with Alzheimer’s disease and in primary tauopathy cases with concomitant Alzheimer’s disease pathology. In contrast, cortical binding to primary tauopathy in cases without paired helical filament tau was found to be within the range of age-matched controls. Off-target binding to monoamine oxidase B has been overcome, as demonstrated by heterologous blocking studies in basal ganglia tissue. The high variability of cortical tracer binding within the Alzheimer’s disease group followed the same pattern with each tracer, suggesting that all compounds are suited to differentiate Alzheimer’s disease from other dementias.
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Hooper, Michael. « THE START OF PERFORMANCE, OR, DOES COLLABORATION MATTER ? » Tempo 66, no 261 (juillet 2012) : 26–36. http://dx.doi.org/10.1017/s0040298212000241.
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AbstractThis article presents a view of the first meetings between the oboe virtuoso Christopher Redgate and the composers Dorothy Ker and Fabrice Fitch. The article details some aspects of these meetings to highlight the processes that are at play in the earliest stages of collaboration. These processes are both practical (in which information about how the oboe works is uncovered and shared) and philosophical (in which the oboe itself becomes a significant source of new possibilities). The article traces a period during which Redgate was developing a new oboe, working with composers to create new repertoire for the new instrument. Arguing for closer attention to the ‘everyday’ aspects of composers and performers working together, the article explores some of the ways in which Redgate pulls apart his experience of performing to develop new technique and to opening up new possibilities for future composition. I also argue that the oboe, as much as the composer and performer, plays a part in shaping musical outcomes.
Thèses sur le sujet "Composés traces"
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Ménard, Camille. « Biofiltration du méthane avec ou sans composés traces sur un milieu filtrant inorganique ». Thèse, Université de Sherbrooke, 2013. http://hdl.handle.net/11143/6135.
Texte intégralRésumé :
Résumé: L'émission de méthane par les activités anthropiques est un problème majeur en relation caractérisé par le changement climatique. Les sites d'enfouissement sanitaire sont responsables de près d'un quart des émissions de méthane au Canada, deuxième gaz à effet de serre après le dioxyde de carbone. Les solutions de récupération du biogaz, issu de la décomposition des déchets déposés dans des sites d'enfouissement, majoritairement composé de méthane et de dioxyde de carbone, existent. La valorisation énergétique par combustion, le brûlage par torchère, se développent dans plusieurs sites. Cependant, les critères de faisabilité technique et de rentabilité économique de ces procédés ne permettent pas de couvrir l'ensemble des sources et des types d'émissions de biogaz. Dans cette configuration de non respect de ces critères, la biofiltration est un procédé d'élimination du biogaz attractif en particulier pour les sites d'enfouissement de petites tailles et ceux «âgés», ainsi qu'en complément des solutions de valorisation énergétique. Les paramètres essentiels de la biofiltration du méthane sont expliqués dans une revue de littérature. De plus, une présentation de la composition complexe du biogaz est réalisée dans cette revue de littérature, permettant l'introduction d'un nouveau paramètre à prendre en considération lors de l'élimination du méthane : la présence de composés à l'état de traces. Ainsi, après l'étude approfondie de trois paramètres sur la biofiltration du méthane, la température, la quantité de solution nutritive et la concentration de dioxyde de carbone, l'étude s'est portée sur l'analyse de deux mélanges binaires avec l'introduction soit d'un composé aromatique, (mélange méthane/toluène), soit d'un composé aromatique halogéné, (mélange méthane/chlorobenzène). Les effets de la charge d'entrée du méthane et de la variation de la concentration des composés traces ont été étudiés. Enfin, la recherche s'est finalement concentrée sur l'influence du toluène sur l'élimination du méthane en effectuant des expériences micro-cinétique et macro-cinétique sur ce mélange spécifique. La présence de ces deux composés traces s'avère .avoir un impact négatif sur l'élimination du méthane, en particulier aux charges d'entrée de méthane testées les plus élevées||Abstract: Anthropic methane emissions are of major concern since it contributes to climate change. Landfills are responsible for about one quarter of methane emissions in Canada, second most important greenhouse gas after carbon dioxide. Energetic valorization is an adapted solution to capture the biogas, produced from the decomposition of organic matter buried in sanitary landfills, and to convert this mixture of methane and carbon dioxide into heat and electricity. Many sites develop the valorization by combustion or by flaring. However, biogas emissions are not entirely treated, as some technical and economical criterion may be encountered. Biofiltration will be more appropriate for old and small landfills, and will be an efficient complementary treatment to the energetic valorization. The most important parameters of biofiltration had been reviewed. Moreover, the complexity of the biogas mixture is presented, which underline a new parameter to take into account in methane elimination: the presence of trace gas compounds. First, three important parameters, the temperature, the amount of nutrient solution and the concentration of carbon dioxide, were studied to be optimized in the configuration of biofiltration of methane alone. Then, two binary mixtures were analyzed, with the introduction of either an aromatic compound for the mixture methane/toluene, or a halogenated aromatic compound for the mixture of methane/chlorobenzene. The effect of the inlet load of methane was studied, in addition to the concentration of trace gas compounds. Finally, the study focused on the influence of toluene on methane biofiltration in regards to the micro-kinetic or macrokinetic parameters. Both toluene and chlorobenzene, the two trace gas compounds evaluated, had a negative impact on methane biofiltration at high inlet loads of methane, while negligible effects were observed at lower methane inlet load.
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Tuduri, Ludovic. « Analyse de traces de composés organiques volatils dans l'air par microextraction sur phase solide ». Pau, 2002. http://www.theses.fr/2002PAUU3007.
Texte intégralRésumé :
L'objectif de ce travail est le développement d'une méthode d'analyse de composés organiques volatils en traces dans l'air après pré-concentration par MicroExtraction sur Phase Solide. Dans un premier temps, un générateur d'atmosphères étalons basé sur le principe de l'injection continue a été développé et validé. Il est capable de générer des concentrations gazeuses allant jusqu'à 100 ng. M-3. La validité de l'étalonnage externe du CPG par des solutions étalons pour quantifier les composés extraits par MEPS a été examinée et confirmée à travers deux séries d'expériences. La première consiste à extraire successivement un même échantillon avec une fibre MEPS à phase stationnaire absorbante et modéliser les courbes d'épuisement de l'échantillon en utilisant ou non l'étalonnage externe. La seconde est une comparaison de l'extraction par solvant et de la désorption thermique pour la détermination des quantités présentes sur les fibres MEPS. Les cinétiques de sorption d'un mélange de 11 COVs, représentatifs d'un usage industriel et possédant des propriétés et des fonctionnalités physico-chimiques variées, ont ensuite été tracées pour 5 fibres MEPS à phase stationnaire différente. Parmi elles, la fibre PDMS/Carboxen est la plus performante en terme de sensibilité pour les 11 composés. L'affinité des composés pour cette fibre croît avec leur volume moléculaire. En contrepartie, des phénomènes de compétition d'adsorption apparaissent. Pour mieux les comprendre et les éviter par la suite, l'étalonnage est réalisé pour les composés seuls ou en mélange dans l'air, pour plusieurs temps d'exposition, en mode statique et dynamique. Les résultats montrent qu'au deçà d'une certaine quantité adsorbée propre à chaque composé, l'analyse quantitative de traces de COVs est réalisable. Les limites de détection se situent autour du æg. M-3 pour 1 min. D'échantillonnage et autour de 100 ng. M-3 pour 45 min. Deux applications sont ensuite présentées: la comparaison de la technique des tubes remplis d'adsorbants et de la MEPS pour l'analyse qualitative des COVs dans des vitrines de musée montre, qu'à temps d'échantillonnage identique, un plus grand nombre de composé peut être identifié par MEPS. Puis l'analyse quantitative en routine de COVs en traces avec la fibre PDMS/Carboxen dans un type de salle blanche est réalisable.
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Gille, Philippe. « Spectrometrie de masse analytique : developpement de techniques nouvelles pour l'analyse de traces d'organochlores ». Paris 6, 1993. http://www.theses.fr/1993PA066375.
Texte intégralRésumé :
Parmi les nombreuses substances contaminant l'environnement, nous nous sommes interesses aux polychlorodibenzoparadioxines, polychlorodibenzofurannes, polychlorobiphenyles et a certains pesticides chlores. Pour quantifier avec precision ces composes presents a l'etat de faibles traces dans des matrices souvent complexes, il faut disposer de methodes analytiques extremement sensibles et specifiques. Les recents progres du couplage de la chromatographie en phase gazeuse et de la spectrometrie de masse (cpg/sm) ouvrent de nouvelles perspectives de recherches analytiques. La chromatographie en phase gazeuse sur colonne capillaire est une methode de separation tres puissante permettant de doser globalement une famille d'isomeres ou plus specifiquement certains congeneres. Apres optimisation, nous avons montre sur une colonne capillaire de fin diametre que les temps d'analyse pouvaient etre divises par deux dans le cas des polychlorodibenzo-p-dioxines et polychlorodibenzofurannes. La spectrometrie de masse offre des possibilites incomparables pour l'identification et le dosage de composes organiques. A haute resolution, la technique tres sensible d'enregistrement d'ions elimine de nombreuses interferences, avec une bonne sensibilite de detection. En couplage cpg/sm, malgre la haute selectivite chromatographique et le pouvoir de resolution en masse du spectrometre, les possibilites d'interferences restent nombreuses. Nous avons montre, a partir d'echantillons reels, qu'il est possible d'eliminer ces interferences en jouant sur la resolution en masse du spectrometre et le choix des ions enregistres, en utilisant des techniques d'ionisation plus specifiques ou en etudiant des reactions de filiations specifiques entre ions (techniques sm/sm). Pour plusieurs familles de composes, nous avons compare apres optimisation sur un appareil a geometrie ebqq, la resolution des interferences et les limites de sensibilite des techniques sm haute resolution, sm-sm en premiere et troisieme region libre de champ et avons demontre l'interet de la sm-sm pour le dosage de traces. Nous avons ainsi etabli des protocoles operatoires valides conformement aux bonnes pratiques de laboratoire
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Couffin, Nathalie. « Elimination de composes organohalogenes volatils a l'etat de traces dans l'eau par distillation membranaire sous vide ». Toulouse, INSA, 2000. http://www.theses.fr/2000ISAT0007.
Texte intégralRésumé :
L'originalite de cette etude reside dans la perspective d'utilisation d'un contacteur a membrane, la distillation membranaire sous vide (dmv) dans une filiere d'eau potable, en traitement d'affinage. L'objectif est d'eliminer les composes organohalogenes volatils a l'etat de traces dans l'eau et de produire une eau conforme aux valeurs guides europeennes. A l'issue d'une synthese et d'une analyse bibliographique sur les materiaux membranaires poreux puis d'une etude de caracterisation de six membranes planes, les criteres de selection d'une membrane adaptee a la dmv pour l'application concernee sont presentes et discutes. Une modelisation du procede a ete developpee en prenant en compte le couplage du transfert de matiere et de chaleur. Ce modele a ete valide experimentalement. L'influence des principaux parametres operatoires sur les performances du procede a ete caracterisee experimentalement. Puis, une simulation de la dmv a l'echelle industrielle permet de definir les conditions operatoires minimisant la consommation energetique totale de dmv pour un module plan industriel. Les premiers elements de conception d'un module plan industriel sont proposes et compares a ceux d'un module fibres creuses, plus prometteurs. Enfin, cette etude est cloturee par une comparaison technico-economique de la dmv avec des procedes conventionnels et la nanofiltration.
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Nicolle, Jérôme. « Développement d'une méthodologie d'analyse de composés organiques volatils en traces pour la qualification de matériaux de construction ». Phd thesis, Université de Pau et des Pays de l'Adour, 2009. http://tel.archives-ouvertes.fr/tel-00401405.
Texte intégralRésumé :
La qualité de l'air intérieur est maintenant reconnue comme une question de santé publique, notamment avec la proposition de valeurs guides de concentrations pour des polluants tels que les composés organiques volatils (COV). Ainsi, suite aux consignes émises par l'Agence Française pour la Sécurité Sanitaire de l'Environnement et du Travail (AFSSET), des stratégies d'échantillonnage et de mesure des COV émis par les matériaux de construction ont été définies dans un contexte normatif. Ces méthodes, dédies au contrôle en laboratoire, sont peu adaptées aux mesures sur site. L'identification des sources de COV, indispensable au diagnostic de la qualité de l'air intérieur, nécessite donc des outils de prélèvement simples et rapides. Une alternative, basée sur le couplage d'une cellule d'émission (FLEC*) avec un prélèvement passif par SPME (micro-extraction sur phase solide) a donc été envisagée. Le développement de cette méthodologie a été effectué sur des atmosphères étalons de COV modèles (hydrocarbures, terpènes, composés oxygénés, ...), permettant ainsi de déterminer des limites de détection de l'ordre du μg.m-3 (GC-MS) et des concentrations quantifiables (GC-FID) au-delà de 10 mg.m-3. Les performances de cette méthode ont permis son application à différents matériaux (moquette, panneau de bois et PVC), montrant ainsi la possibilité d'effectuer un rapide screening des COV émis, mais aussi de déterminer 96 % des composés d'intérêt définis par le protocole AFSSET. Enfin, l'étude d'un immeuble de bureaux a montré la faisabilité de l'utilisation sur site du couplage FLEC*-SPME pour caractériser les principales sources de COV provenant des matériaux de construction présents.
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Nicolle, Jérôme. « Développement d’une méthodologie d’analyse de composés organiques volatils en traces pour la qualification de matériaux de construction ». Pau, 2009. https://theses.hal.science/index.php?halsid=q0ep6b0frblf1gervo0lpeqb42&view_this_doc=tel-00401405&version=1.
Texte intégralRésumé :
La qualité de l’air intérieur est maintenant reconnue comme une question de santé publique, notamment avec la proposition de valeurs guides de concentrations pour des polluants tels que les composés organiques volatils (COV). Ainsi, suite aux consignes émises par l’Agence Française pour la Sécurité Sanitaire de l’Environnement et du Travail (AFSSET), des stratégies d’échantillonnage et de mesure des COV émis par les matériaux de construction ont été définies dans un contexte normatif. Ces méthodes, dédies au contrôle en laboratoire, sont peu adaptées aux mesures sur site. L’identification des sources de COV, indispensable au diagnostic de la qualité de l’air intérieur, nécessite donc des outils de prélèvement simples et rapides. Une alternative, basée sur le couplage d’une cellule d’émission (FLEC*) avec un prélèvement passif par SPME (micro-extraction sur phase solide) a donc été envisagée. Le développement de cette méthodologie a été effectué sur des atmosphères étalons de COV modèles (hydrocarbures, terpènes, composés oxygénés, …), permettant ainsi de déterminer des limites de détection de l’ordre du μg. M-3 (GC-MS) et des concentrations quantifiables (GC-FID) au-delà de 10 mg. M-3. Les performances de cette méthode ont permis son application à différents matériaux (moquette, panneau de bois et PVC), montrant ainsi la possibilité d’effectuer un rapide screening des COV émis, mais aussi de déterminer 96 % des composés d’intérêt définis par le protocole AFSSET. Enfin, l’étude d’un immeuble de bureaux a montré la faisabilité de l’utilisation sur site du couplage FLEC*-SPME pour caractériser les principales sources de COV provenant des matériaux de construction présentsNowadays, indoor air quality is considered as a public health concern, as demonstrated by the legislation proposal of concentrations guidelines for pollutants such as volatile organic compounds (VOC). Thus, according to the French Agency for Environmental and Occupational Health Safety (AFSSET) recommendations, measurements of VOCs emitted by building materials and sampling strategies were standardized. However, these laboratory-based methods are less suitable to on-site measurements. The VOCs sources identification, necessary to indoor air quality diagnosis, needs rapid and simple sampling tools. An alternative, based on the coupling of an emission cell (FLEC) with a passive sampling strategy using SPME (solid phase microextraction) was considered. This methodology was developed using standard gas of model VOCs (hydrocarbons, terpenese, oxygenated compounds, …) and reached detection limits in the order of μg. M-3 (GC-MS) and quantification limits (GC-FID) around 10 mg. M-3. The analytical performances of this method allowed its application to different building materials (carpet, wood panel and PVC), demonstrating its ability to perform rapid screenings of the emitted VOCs and to determine 96 % of the compounds listed in the AFSSET protocol. Finally, as an example, a whole building was studied, illustrating the feasibility to use the FLEC-SPME system on-site to characterize the major sources of VOCs from building materials
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Andre, Jean-Marc. « Recherche en écotoxicologie marine sur la contamination des Delphinidés par les micropolluants : métaux-traces et composés organochlorés ». Bordeaux 1, 1988. http://www.theses.fr/1988BOR10613.
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HUTEAU, BERTRAND, et M. F. BONNORD. « Identification et dosage de traces d'organohalogenes par des methodes separatives et spectrometrie de masse. Application aux matrices biologiques ». Paris 6, 1991. http://www.theses.fr/1991PA066164.
Texte intégralRésumé :
Produits par l'industrie chimique comme composes derivant de reactions parasites, les proprietes toxiques des polychlorodibenzo-p-dioxines et des polychlorodibenzofurannes (pcdd et pcdf) ont ete etablies chez l'animal. Chez l'homme des atteintes hepatiques et cutanees ont ete observees mais rien ne permet d'etablir avec certitude leurs caracteres mutagenes et cancerigenes. Ces substances sont tres stables et bioaccumulables et il est necessaire de posseder un outil d'analyse qui permet de les identifier et de les doser dans differentes matrices a l'etat de traces (quelques picogrammes par gramme) parmi d'autres composes en quantites plus importantes. Apres avoir evalue les performances de l'outil analytique, le couplage cg/sm, nous avons defini un protocole de preparation d'echantillon adapte a chaque matrice. L'utilisation de la clhp est limitee a l'etape de purification et non de dosage. Le protocole permet d'acceder a la meme purete que celle d'un extrait purifie sur des colonnes d'adsorbants tout en etant plus rapide. Le protocole d'analyse elabore pour les echantillons biologiques a ete applique a l'evaluation de l'exposition aux pcdd et pcdf de deux populations differentes par dosage de ces composes dans le tissu adipeux, et, d'autre part, au dosage de ces polluants dans des laits maternels
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Sablayrolles, Caroline. « Etude fondamentale de transferts des composés traces organiques aux plantes : cas des systèmes amendés par des boues d'épuration ». Toulouse, INPT, 2004. http://www.theses.fr/2004INPT024A.
Texte intégralRésumé :
La première phase de ces travaux a été consacrée à l'étude analytique des composés traces organiques contenus dans le sol, les boues d'épuration et les végétaux. Les hydrocarbures aromatiques polycycliques, polychlorobiphényles, phtalates, nonylphénols éthoxylés et laurylalkylbenzènes sulfonates ont été étudiés. Les protocoles de pré-traitement, d'extraction, de purification et d'analyse des échantillons ont été optimisés pour obtenir, selon le type de matrice ou de composé, le protocole le plus approprié à caractériser de façon fiable les composés traces organiques. L'extraction est réalisée dans un Soxtec, appareil qui permet des extractions rapides, économiques et sécurisées. La purification est menée sur des cartouches spécifiques par la technique d'extraction sur phase solide. L'analyse est réalisée par chromatographie gazeuse couplée à la spectrométrie e masse et/ou par chromatographie liquide haute performance couplée à un détecteur fluorimétrique. Ces deux techniques, sensibles et sélectives, permettent d'atteindre de très faibles limites de détection. La seconde phase des travaux a été consacrée à l'étude du transfert des composés traces organiques en vases de végétation. Une étude en hors-sol, où tous les paramètres étaient maîtrisés, a permis de valider les choix analytiques. Lors de l'étude en sol, les composés traces organiques étudiés ont été apportés par l'intermédiaire de boues résiduaires urbaines. Le suivi de la croissance des plantes (carottes et tomates) a montré que l'apport de boue accroît la production végétale. Les teneurs en composés traces organiques initialement contenus dans les vases de végétation ont été suivies dans les plantes. Les pourcentages de transfert des composés traces organiques sont faibles. Enfin, les résultats obtenus ont été intégrés à une analyse de cycle de vie sur les impacts environnementaux de deux filières d'utilisation agronomique des boues depuis la boue déshydratée jusqu'à la production végétale à l'échelle des vases de végétation de l'étudeThe first part of this work concerns an anlytical study of the trace organic compounds contained in the soil, sewage sludges and plants. These were : auromatic polycyclic hydrocarbons, polychlorobiphenyls, phthalates, nonylphenol ethoxylates and laurylalkylbenzene sulfonates; The pre-treatment, extraction, purification and analysis of samples has been optimized in order to obtain the most appropriate, reliable protocol to characterize the trace organics for the particular type of matrix or compound. The extraction uses a Soxtec apparatus which is fast, economical and safe. Purification is by solid phase cartridges, specific to the extraction technique. Analysis is by gas chromatography coupled to a mass spectrometer and/or by high performance liquid chromatography coupled to a fluorimetric detector. Both these techniques are sensitive and selective and permit very low limits of detection. The second part of the work concerns a study of the uptake of the organics in containers of plants. An aquiculture study where all the parameters are controlled has enabled validation of the analytical choices. For the in-soil studies the trace organics in question have been introduced via residual urban sludges. Plant growth monitoring (carrots and tomatoes), shows that the addition of sludge increases plant production. The initial levels of trace organics in the plant containers have been compared to those found in the plants; the percentage uptake of trace organics is low. Finally, the results obtained have been incorporated into a life cycle analysis on the environmental impact of two agronomic, sludge use sectors, from the dewatered sludge through to plant production, using plants growing in containers
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Donadio, Clara. « Traces d’ADN bactérien et composés volatils comme premiers éléments de traçabilité des sels de terroir de l’océan Atlantique ». Thesis, La Réunion, 2014. http://www.theses.fr/2014LARE0006/document.
Texte intégralRésumé :
Exploité depuis toujours, le sel a connu, au temps de la Gabelle notamment, des heures de gloire certaines, faisant de lui un métal blanc précieux, recherché et coûteux. Cependant, de nos jours, il est considéré comme un minéral essentiel, certes, mais aussi dangereux pour la santé si surconsommé. Ainsi, les paludiers d'aujourd’hui doivent mettre en avant le caractère authentique de leur produit et leur savoir-faire ancestral, symboles de qualité dans l'esprit des contemporains, pour réussir à maintenir leur activité et leur part de marché. L'objectif de cette étude était ainsi de définir des pistes qui garantiraient aux paludiers la protection de leur travail, par exemple dans le cadre d'une démarche d'appellation d'origine contrôlée ou protégée. Pour ce faire, un partenariat avec des sauniers de la Côte Atlantique Française (Ile de Ré, Ile de Noirmoutier, presqu'Ile de Guérande, salines de Saint-Armel) a permis de collecter divers échantillons (eaux des marais, sels). Dans un premier temps, une recherche de microorganismes et une étude sur les traces d'ADNr-16S présent sur les cristaux de sel, ont permis de caractériser une partie du microbiote halophile se développent au niveau des bassins de production du sel de mer, alors que leur teneur en sel peut aller jusqu'à 25 %. Dans un second temps, une recherche de composés volatils a été conduite afin de déterminer si l'environnement pouvait influencer l'empreinte olfactive des eaux des marais et du sel lors de sa formation et / ou de sa récolte. Un protocole d'extraction et d'analyses a été développé et a permis la mise en évidence d'un profil en composés volatils propre à chaque bassin. Parmi les composés volatils détectés, de nombreux norisoprénoïdes, provenant probablement de la dégradation de caroténoïdes produits par les microorganismes halophiles, ont ainsi été identifiés : pour le « bassin » Ile de Ré, 21 composés volatils ont été identifiés dont 8 composés dérivés des caroténoïdes (CDC) ; pour le « bassin » de Noirmoutier, 13 composés dont 7 CDC ; pour le « bassin » de Saint-Armel, 54 composés dont 25 CDC ; pour le « bassin » Guérandais, 19 composés dont 10 CDC.D'une façon générale, les résultats obtenus aussi bien d'un point de vue microbiologique que chimique, ont révélé une forte corrélation entre les marais salants et le sel qu'ils produisent : les microorganismes spécifiques d'un environnement laissent des empreintes sur les eaux et le sel, ce qui permettrait notamment aux paludiers de caractériser leur produit en vue d'une protection basée sur de véritables marqueurs propres à chaque marais (pour des origines distantes de quelques kilomètres, des différences sont déjà notables entre salines tant au niveau « odeur » qu'au niveau microbiote)Salt has always been exploited in living memory. It has known its heyday at several occasions throughout history, particularly during the period of the French Gabelle, and therefore came to be seen as a precious white metal both sought after and expensive. Yet, nowadays, although it has been considered as an essential mineral, it has also turned up to be unhealthy when taken in excessive amounts. Consequently, salt workers of our day and age have to highlight the genuine nature of their product as well as their ancestral skills, for they both stand out as tokens of quality for our contemporaries. Meeting the expectations of the consumer is the only way for them to keep up with their work and maintain their share on the market. Thus, this study aimed to define ways for salt workers to have their work preserved, for instance throughout a Protected Designation of Origin. Therefore, a partnership with Atlantic French salt workers (from Ré Island, Noirmoutier, Guérande and Saint-Armel) has been established, allowing us to collect samples of salt marsh water and salts.First, an overview of microorganism population and 16S-rDNA in each water or salt sample permitted to define what kinds of microorganism populations were to be found in salt marshes. Secondly, a search for volatile components was led so as to determine whether the environment might affect the olfactory footprint of salt marshes and of salt itself during its formation and its harvest. A process of extraction and analysis has been developed, shedding light on a link between the origin and the olfactory footprint of salt. As an example, the halophilous microorganisms which are extremely rich in carotenoid (hence the red-orange colour of some marshes) are partly responsible for the presence of norisoprenoids in the volatile components which have been identified: 21 compounds were identified in Ré Island (including 8 norisoprenoids), 13 in Noirmoutier (including 7 norisoprenoids), 54 in Saint-Armel (including 25 norisoprenoids),19 in Guérande (including 10 norisoprenoids).For each area, DNA traces and volatile profiles were identified. Therefore, a strong link can be established between salt marshes and the salt they produce. It appears that the differences between salt flats regarding either their smell or their microbiota is always noteworthy, even when marshes are only a few miles apart. Thus, the specific pool of the identified microorganisms which leave prints on the salt would allow saltworkers to define their product so as to ensure a form of protection based on specific markers which are proper to each marsh
Livres sur le sujet "Composés traces"
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J, Statham P., dir. Inorganic trace analysis : Philosophy and practice. Chichester : Wiley, 1993.
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Zolotov, A. A. (Andreĭ Andreevich), author, dir. Znaki zhizni : Neizvestnyĭ Sviridov = Traces of a life : the unknown Sviridov. Moskva : T︠S︡entr knigi Rudomino, 2014.
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Belhassine, Naoufel. Hédi Jouini : La trace d'un géant. Nice : Bénévent, 2009.
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Küng, Hans. Mozart : Traces of transcendence. Grand Rapids, Mich : W.B. Eerdmans Pub. Co., 1993.
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Canadian Council of Ministers of the Environment. Compost Guidelines Task Group. Guidelines for compost quality. [Winnipeg] : Canadian Council of Ministers of the Environment, 2005.
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Simsova, Sylva. Traces in the sand : The story of Anthony Kammel in 18th century Britain. Newcastle-under-Lyme : Dvořák Society, 2014.
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Dusapin, Pascal. Flux, trace, temps, inconscient : Entretiens sur la musique et la psychanalyse. Nantes : Defaut, 2012.
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Brahms dopo Brahms : Tracce panoramiche di una discendenza e di un'eredità. Lucca : Libreria musicale italiana, 2009.
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Palák, Milan. Po stopách Gustava Mahlera v Čechách a na Moravě = : Auf den Spuren von Gustav Mahler in Böhmen und Mähren = In Gustav Mahler's footsteps in Bohemia and Moravia = Sur les traces de Gustav Mahler en Bohême et en Moravie = In Gustav Mahler's voetsporen in Bohemen en Moravië. Ostrava : Milan Palák, 2003.
Trouver le texte intégralChapitres de livres sur le sujet "Composés traces"
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Massiani, C., et M. Domeizel. « Quality of Composts : Organic Matter Stabilization and Trace Metal Contamination ». Dans The Science of Composting, 185–94. Dordrecht : Springer Netherlands, 1996. http://dx.doi.org/10.1007/978-94-009-1569-5_19.
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Shimizu, Sota, Taro Suzuki, Masaya Ogawa, Yoshiyuki Fukazawa, Yuzo Shibayama et Takumi Hashizume. « Disaster Back-up Support using GIS Contents Composed of Images from Satellite and UAV ». Dans Springer Tracts in Advanced Robotics, 81–96. Berlin, Heidelberg : Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-40686-7_6.
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Sloan, John J., et Don Cawthon. « Mine Soil Remediation Using Coal Ash and Compost Mixtures ». Dans Chemistry of Trace Elements in Fly Ash, 309–18. Boston, MA : Springer US, 2003. http://dx.doi.org/10.1007/978-1-4757-4757-7_21.
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Pastoors, Andreas, et Tilman Lenssen-Erz. « Introduction ». Dans Reading Prehistoric Human Tracks, 1–11. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-60406-6_1.
Texte intégralRésumé :
AbstractThis book explains that after long periods of prehistoric research in which the importance of the archaeological as well as the natural context of rock art has been constantly underestimated, research has now begun to take this context into focus for documentation, analysis, interpretation and understanding. Human footprints are prominent among the long-time under-researched features of the context in caves with rock art. In order to compensate for this neglect an innovative research program has been established several years ago that focuses on the merging of indigenous knowledge and western archaeological science for the benefit of both sides. The book composes first the methodological diversity in the analysis of human tracks. Here major representatives of anthropological, statistical and traditional approaches feature the multi-layered methods available for the analysis of human tracks. It second compiles case studies from around the globe of prehistoric human. For the first time the most important sites which have been found worldwide are published in a single publication. The third focus of this book is on first hand experiences of researchers with indigenous tracking experts from around the globe, expounding on how archaeological science can benefit from the ancestral knowledge.
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Avanzini, Marco, Isabella Salvador, Elisabetta Starnini, Daniele Arobba, Rosanna Caramiello, Marco Romano, Paolo Citton et al. « Following the Father Steps in the Bowels of the Earth : The Ichnological Record from the Bàsura Cave (Upper Palaeolithic, Italy) ». Dans Reading Prehistoric Human Tracks, 251–76. Cham : Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-60406-6_14.
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AbstractThe chapter summarizes the new results of the Bàsura Revisited Interdisciplinary Research Project. The integrated interpretation of recent archaeological data and palaeosurface laser scans, along with geoarchaeological, sedimentological, geochemical and archaeobotanical analyses, geometric morphometrics and digital photogrammetry, enabled us to reconstruct some activities that an Upper Palaeolithic human group led inside a deep cave in northern Italy within a single exploration event about 14 ka calBP. A complex and diverse track records of humans and other animals shed light on individual- and group-level behaviour, social relationship and mode of exploration of the uneven terrain. Five individuals, composed of two adults, an adolescent and two children, entered the cave barefoot lightening the way with a bunch of wooden sticks (Pinus t. sylvestris/mugo bundles). While proceeding, humans were forced to move on all fours, and the traces they left represent the first report of crawling locomotion in the global human ichnological record. Anatomical details recognizable in the crawling traces show that no clothing was present between limbs and the trampled sediments. Our study demonstrates that very young children (the youngest about 3 years old) were active members of the human groups, even in apparently dangerous and social activities, shedding light on behavioural habits of Upper Palaeolithic populations.
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Dandeniya, Warshi S., et Serena Caucci. « Composting in Sri Lanka : Policies, Practices, Challenges, and Emerging Concerns ». Dans Organic Waste Composting through Nexus Thinking, 61–89. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36283-6_4.
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AbstractCompost is a widely accepted organic fertiliser throughout the world. It is being produced using a wide variety of source materials at household to commercial scale. With the increased population and changes in food consumption pattern tending towards a vegetable- and meat-rich diet, the amount of organic waste generated in urban and peri-urban settings has increased. Many governments promote composting as a process that helps them to reduce the volume of organic waste and recycle nutrients back to croplands. Some examples of organic waste accumulated in large scale include household waste from urban and peri-urban settings, sewage, animal farm waste, agricultural waste from large-scale markets, food debris, and kitchen waste from hotels. The composition of compost varies in a wide range depending on the nature of materials used to produce it. The safety concerns related to compost also vary along the same line. The quality of compost has become a subjective term that means different aspects to different bodies due to a lack of commonly agreed standards to regulate the composting process and the final product itself. Recent research findings indicate that compost can serve as a carrier of potentially toxic trace elements, organic pollutants, and determinants of antimicrobial resistance to the environment and along the food chain. Producing good-quality compost safe to human health and the environment at large has become a challenge that should be addressed at various levels: from production to policymaking. This chapter discusses some of the major challenges faced in Sri Lanka with compost making. To prepare the background for this discussion, information on the policies and current practices of nutrient management in Sri Lanka is also presented. The context may be applicable to many other developing countries in the tropics.
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Galatà, Francesco. « Per la fortuna del Decameron nella letteratura di fine Ottocento : riscritture pascoliane edite e inedite ». Dans Studi e saggi, 155–74. Florence : Firenze University Press, 2022. http://dx.doi.org/10.36253/978-88-5518-668-1.09.
Texte intégralRésumé :
Although Boccaccio’s name is rarely encountered in published works of Giovanni Pascoli (1855-1912), traces of a constant reading and reuse of the Decameron have emerged and continue to emerge from the poet’s manuscripts. The article outlines the history of the already known contacts between the two authors and adds a new document: the unknown verse drama ‘Messer Gentile’, inspired by the novella X 4. This drama, designed as a one-act play with a prologue and three scenes, has been left unfinished: only the prologue and the first scene are preserved, but it is enough to appreciate some dynamics that characterize the rewriting process. A dense network of references to the most ancient Italian poetic tradition emerges from the dramatic lines, and among the manuscripts one discovers an experimental rhythmic prose composed of hendecasyllables arranged in a line that the study reconnects to the reform of modern tragic theater envisaged by Pascoli. Sebbene il nome di Boccaccio si incontri molto raramente nell'opera di Giovanni Pascoli (1855-1912), dai manoscritti del poeta sono emerse e continuano a emergere tracce di una lettura costante del Decameron. Il contributo ripercorre la storia dei contatti già noti tra i due autori e aggiunge un nuovo documento: l'inedito dramma in versi 'Messer Gentile' ispirato alla novella X 4. Il dramma, progettatto come atto unico con prologo e tre scene, rimase incompiuto: ci sono giunti soltanto il prologo e la prima scena, che sono sufficienti per apprezzare alcune delle dinamiche che caratterizzano la riscrittura. Dai versi emerge una fitta rete di riferimente alla tradizione poetica italiana delle origini e tra i manoscritti si ritrova un esperimento di prosa modulata sul ritmo continuato degli endecasillabi riconducibile all'idea di moderno teatro tragico di Pascoli.
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Yirenya-Tawiah, Dzidzo, Ted Annang, Benjamin Dankyira Ofori, Benedicta Yayra Fosu-Mensah, Elaine Tweneboah Lawson, Richard Yeboah, Kwaku Owusu-Afriyie et al. « Urban Waste as a Resource : The Case of the Utilisation of Organic Waste to Improve Agriculture Productivity Project in Accra, Ghana ». Dans Organic Waste Composting through Nexus Thinking, 123–45. Cham : Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-36283-6_6.
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AbstractPoor municipal solid waste management continues to be a daunting issue for municipal authorities in Ghana. Major cities generate 2000 tonnes of mixed municipal waste per day, of which about 80% is collected and disposed of at open dump sites and/or at the limited number of landfills available. About 60% of this waste is organic. The Utilization of Organic Waste to Improve Agricultural Productivity (UOWIAP) project sought to co-create knowledge through a private-public engagement for the development of organic waste value chain opportunities to sustainably manage municipal organic waste and, at the same time, improve urban farm soils and increase food productivity in the Ga-West Municipal Assembly in the Greater Accra Region of Ghana. Through the project, identified key stakeholders in the waste and agricultural sectors, such as market traders, informal waste collectors, unemployed persons, farmers, landscapers, media, agricultural extension officers, Municipal Assembly officers and the general public, were engaged and made aware of sustainable organic waste management processes, including organic waste segregation from source, collection and compost production. Four formal markets were selected for the piloting of organic waste segregation from source. Interested persons were trained in organic waste collection, compost production and entrepreneurship. The lessons learned draw attention to the need for a massive effort to generate demand for compost use as this will invariably drive removal of organic waste from the unsorted waste stream.
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McCarthy, Kerry. « Earliest Traces ». Dans Tallis, 87–98. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190635213.003.0008.
Texte intégralRésumé :
The earliest known document of Tallis’s music is the single voice part that survives from an otherwise lost manuscript collection of early-sixteenth-century devotional music. It contains only one work by Tallis (the large votive antiphon Salve intemerata) and many works by other composers, almost all of them older. Some of this music goes back to the generation that produced the Eton Choirbook at the turn of the sixteenth century. It gives us a rare chance to see where Tallis’s musical style came from. This chapter is a detailed exploration of Salve intemerata and the manuscript where it makes its earliest appearance. Topics include early Tudor voice types, musical rhetoric, and the tradition of large polyphonic works Tallis knew during his first years as a composer.
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Martin, Henry. « Music Background and Compositional Overview ». Dans Charlie Parker, Composer, 35–54. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780190923389.003.0002.
Texte intégralRésumé :
Chapter 1 begins with a discussion of Parker’s life, emphasizing his musical background, his early musical training, and his experiences that bear directly on his future as a jazz saxophonist. This overview tracks Parker’s growing professional stature as well as his role in the development of bebop style. Once Parker achieves significant professional success as a member of the Jay McShann Orchestra (1940–1942), the emphasis in the narrative shifts to his career as a composer. The relationships between Parker and his record companies, which secured his copyrights as publisher, are explored. The chapter ends by discussing his unrecorded compositions, including the possibility that they are not by Parker.
Actes de conférences sur le sujet "Composés traces"
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Almestiri, Saleh M., David H. Myszka, Andrew P. Murray et Charles W. Wampler. « Singularity Traces of Planar Linkages That Include Prismatic and Revolute Joints ». Dans ASME 2015 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/detc2015-47390.
Texte intégralRésumé :
This paper presents a general method to construct a singularity trace for single degree-of-freedom, closed-loop linkages that include prismatic, in addition to, revolute joints. The singularity trace has been introduced in the literature as a plot that reveals the gross motion characteristics of a linkage relative to a designated input joint and design parameter. Previously, singularity traces were restricted to mechanisms composed of only rigid bodies and revolute joints. The motion characteristics identified on the plot include changes in the number of solutions to the forward kinematic position analysis (geometric inversions), singularities, and changes in the number of branches. To illustrate the adaptation of the general method to include prismatic joints, basic slider-crank and inverted slider-crank linkages are explored. Singularity traces are then constructed for more complex Assur IV/3 linkages containing multiple prismatic joints. These Assur linkages are of interest as they form an architecture that is commonly used for mechanisms capable of approximating a shape change defined by a general set of closed curves.
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Reitbauer, Eva, Christoph Schmied et Manfred Wieser. « Autonomous Navigation Module for Tracked Compost Turners ». Dans 2020 European Navigation Conference (ENC). IEEE, 2020. http://dx.doi.org/10.23919/enc48637.2020.9317465.
Texte intégral
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King, Rob. « ‘Music of the People’ : Music From Data as Social Commentary ». Dans ICAD 2019 : The 25th International Conference on Auditory Display. Newcastle upon Tyne, United Kingdom : Department of Computer and Information Sciences, Northumbria University, 2019. http://dx.doi.org/10.21785/icad2019.007.
Texte intégralRésumé :
Data-music reflects the ubiquity of data in modern society. Composers have not engaged widely with the opportunities opened up by this, despite the chance to overcome a gulf between academic art music and social engagement. Their reluctance might be traced to the challenge of reconciling abstract data and concrete sound, in political implications, and in technological barriers in computer music. The present paper argues that socially relevant music composition for the 21st century can adopt a programme of sonification grounded in politically acute data. As examples of such practice, two compositions are discussed founded upon US and UK social data sets, and realised via the SuperCollider programming language. The consequences for the composer of new music are further discussed from political and musicological angles, with the ‘purpose’ of writing such music analysed from the perspective of various commentators.
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Yin, Shi, Shangfei Wang, Guozhu Peng, Xiaoping Chen et Bowen Pan. « Capturing Spatial and Temporal Patterns for Facial Landmark Tracking through Adversarial Learning ». Dans Twenty-Eighth International Joint Conference on Artificial Intelligence {IJCAI-19}. California : International Joint Conferences on Artificial Intelligence Organization, 2019. http://dx.doi.org/10.24963/ijcai.2019/142.
Texte intégralRésumé :
The spatial and temporal patterns inherent in facial feature points are crucial for facial landmark tracking, but have not been thoroughly explored yet. In this paper, we propose a novel deep adversarial framework to explore the shape and temporal dependencies from both appearance level and target label level. The proposed deep adversarial framework consists of a deep landmark tracker and a discriminator. The deep landmark tracker is composed of a stacked Hourglass network as well as a convolutional neural network and a long short-term memory network, and thus implicitly capture spatial and temporal patterns from facial appearance for facial landmark tracking. The discriminator is adopted to distinguish the tracked facial landmarks from ground truth ones. It explicitly models shape and temporal dependencies existing in ground truth facial landmarks through another convolutional neural network and another long short-term memory network. The deep landmark tracker and the discriminator compete with each other. Through adversarial learning, the proposed deep adversarial landmark tracking approach leverages inherent spatial and temporal patterns to facilitate facial landmark tracking from both appearance level and target label level. Experimental results on two benchmark databases demonstrate the superiority of the proposed approach to state-of-the-art work.
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« Adsorption of trace metals and deicing salt in soil amended with compost or biochar ». Dans 2014 ASABE Annual International Meeting. American Society of Agricultural and Biological Engineers, 2014. http://dx.doi.org/10.13031/aim.20141914015.
Texte intégral
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Raykov, Jordan. « Method for Orthogonal Edge Routing of Directed Layered Graphs with Edge Crossings Reduction ». Dans 2nd International Conference on Machine Learning Techniques and Data Science (MLDS 2021). Academy and Industry Research Collaboration Center (AIRCC), 2021. http://dx.doi.org/10.5121/csit.2021.111821.
Texte intégralRésumé :
This paper presents a method for automated orthogonal edge routing of directed layered graphs using the described edge crossings reduction heuristic algorithm. The method assumes the nodes are pre-arranged on a rectangular grid composed of layers across the flow direction and lanes along the flow direction. Both layers and lanes are separated by rectangular areas defined as pipes. Each pipe has associated segment tracks. The edges are represented as orthogonal polylines consisting of line segments and routed along the shortest paths. Each segment is assigned to a pipe and to a segment track in it. The edge crossings reduction uses an iterative algorithm to resolve crossings between segments. Conflicting segments are reassigned to adjacent segment tracks, either by swapping with adjacent segments, or by inserting new tracks and calculating the shortest paths of edges. The algorithm proved to be efficient and was implemented in an interactive graph design tool.
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Leitão, Teresa E., Tiago Martins, Maria José Henriques et J. P. Lobo-Ferreira. « Large Scale Soil-Aquifer-Treatment (SAT-MAR) Physical Model Experiments to Improve Water Quality ». Dans 11th International Conference “Environmental Engineering”. VGTU Technika, 2020. http://dx.doi.org/10.3846/enviro.2020.762.
Texte intégralRésumé :
The effluents from agriculture practices usually contain several contaminants creating an environmental concern to downgradient water bodies. The use of SAT systems to improve the effluents water quality, during the transport of infiltrated water through the unsaturated and saturated zones, can bring a solution for water reclamation, water reuse, and overall as a water resources management tool. The research was carried out under MARSOL project were SAT experiments were executed in a physical (sandbox) model. These experiments aimed to contribute solving the problem of removing rice field contaminants from water, using a soil-aquifer prototype basin to treat water prior to its discharge in Melides lagoon, Portugal. The sandbox model was divided into three sections to test the adsorption and biodegradation capacity of three soil profiles, two of them including soil mixtures of sand with vegetal compost with different layouts. In each section, two tracer experiments were performed with spiked fertilizer and hydrocarbons. To analyse the tracer’s behaviour, monitoring devices were installed in three piezometers for continuous in situ readings of pH, T, EC, ORP and water level, besides water sampling hand-pump for chemical analysis. The results obtained in the experiments gave useful knowledge necessary to build an in situ facility.
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Yang, Li-ling, et Qin Zhan. « Analysis of Trace Components in Neon by Gas Chromatography ». Dans 2022 29th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2022. http://dx.doi.org/10.1115/icone29-92413.
Texte intégralRésumé :
Abstract In order to complete the test of trace concentrations in neon carrier gas of solid tritium breeder system for fusion reactor, it is very necessary to establish a high precision analytical system and develop a method of Gas Chromatography (GC). The GC system was composed of three detectors and five separated columns and other auxiliary systems, meanwhile it has established analysis methods of testing trace He, H2 and impurity components in Ne carrier gas. The results showed that the Relative Standard Deviation (RSD) values of the concentration and peak area of each component were less than 5.0%, and the linear correlation coefficients (R2) were greater than 0.99 with the GC analysis system, which could be used to testing trace concentrations in neon with good repeatability. It could support the requirement of tritium efficiency in the Tritium Analysis and Measurement system (TAMS), besides, it could provide technology data and support for the radiation tritium system.
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Reitbauer, Eva, Christoph Schmied et Michael Schedler. « Integrated Navigation for Tracked Compost Turners Using GNSS, INS, Odometers, Stereo Camera and 3D Map ». Dans 33rd International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS+ 2020). Institute of Navigation, 2020. http://dx.doi.org/10.33012/2020.17700.
Texte intégral
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Ozutsumi, Takenori, Yuichi Niibori et Taiji Chida. « Evaluation of Retardation Effect of Cesium Ions Through Groundwater Unsaturated Zone ». Dans 2016 24th International Conference on Nuclear Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/icone24-60979.
Texte intégralRésumé :
Around near-surface underground, an unsaturated zone is formed in such porous layer composed of mainly silicate and silica sand. In the unsaturated zone in which pores are not completely filled with groundwater but also air, the migration of RNs is influenced by the presence of air phase. So far, though many studies have been reported about the unsaturated zone, little studies on the relation of the unsaturated zone and the migration of RNs have been carried out. In this study, the change of the migration of tracer ions in the unsaturated zone was examined by using a bed column, and analyzed by applying advection dispersion equation to the experimental results. As tracer ions, cesium (Cs) and strontium (Sr) were chosen in this study. These elements are the most important elements for the decontamination of Eastern Japan area caused by Fukushima the Daiichi Nuclear Power Plant accident. The experimental results showed the facilitation of the migration of tracer ions in the unsaturated zone. This causes the decrease in the sorption of tracer ions due to the inhibition of air phase. That is, the increase in the retardation effect by the clogging with air phase in flow paths was not remarkable. In the assessment of RNs migration under the unsaturated condition, these competing effects should be reflected adequately.
Rapports d'organisations sur le sujet "Composés traces"
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Wang, Shenlong, et David Forsyth. Safely Test Autonomous Vehicles with Augmented Reality. Illinois Center for Transportation, août 2022. http://dx.doi.org/10.36501/0197-9191/22-015.
Texte intégralRésumé :
This work exploits augmented reality to safely train and validate autonomous vehicles’ performance in the real world under safety-critical scenarios. Toward this goal, we first develop algorithms that create virtual traffic participants with risky behaviors and seamlessly insert the virtual events into real images perceived from the physical world. The resulting composed images are photorealistic and physically grounded. The manipulated images are fed into the autonomous vehicle during testing, allowing the self-driving vehicle to react to such virtual events within either a photorealistic simulator or a real-world test track and real hardware systems. Our presented technique allows us to develop safe, hardware-in-the-loop, and cost-effective tests for self-driving cars to respond to immersive safety-critical traffic scenarios.
2
Matte, S., M. Constantin et R. Stevenson. Mineralogical and geochemical characterisation of the Kipawa syenite complex, Quebec : implications for rare-earth element deposits. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329212.
Texte intégralRésumé :
The Kipawa rare-earth element (REE) deposit is located in the Parautochton zone of the Grenville Province 55 km south of the boundary with the Superior Province. The deposit is part of the Kipawa syenite complex of peralkaline syenites, gneisses, and amphibolites that are intercalated with calc-silicate rocks and marbles overlain by a peralkaline gneissic granite. The REE deposit is principally composed of eudialyte, mosandrite and britholite, and less abundant minerals such as xenotime, monazite or euxenite. The Kipawa Complex outcrops as a series of thin, folded sheet imbricates located between regional metasediments, suggesting a regional tectonic control. Several hypotheses for the origin of the complex have been suggested: crustal contamination of mantle-derived magmas, crustal melting, fluid alteration, metamorphism, and hydrothermal activity. Our objective is to characterize the mineralogical, geochemical, and isotopic composition of the Kipawa complex in order to improve our understanding of the formation and the post-formation processes, and the age of the complex. The complex has been deformed and metamorphosed with evidence of melting-recrystallization textures among REE and Zr rich magmatic and post magmatic minerals. Major and trace element geochemistry obtained by ICP-MS suggest that syenites, granites and monzonite of the complex have within-plate A2 type anorogenic signatures, and our analyses indicate a strong crustal signature based on TIMS whole rock Nd isotopes. We have analyzed zircon grains by SEM, EPMA, ICP-MS and MC-ICP-MS coupled with laser ablation (Lu-Hf). Initial isotopic results also support a strong crustal signature. Taken together, these results suggest that alkaline magmas of the Kipawa complex/deposit could have formed by partial melting of the mantle followed by strong crustal contamination or by melting of metasomatized continental crust. These processes and origins strongly differ compare to most alkaline complexes in the world. Additional TIMS and LA-MC-ICP-MS analyses are planned to investigate whether all lithologies share the same strong crustal signature.
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Chriscoe, Mackenzie, Rowan Lockwood, Justin Tweet et Vincent Santucci. Colonial National Historical Park : Paleontological resource inventory (public version). National Park Service, février 2022. http://dx.doi.org/10.36967/nrr-2291851.
Texte intégralRésumé :
Colonial National Historical Park (COLO) in eastern Virginia was established for its historical significance, but significant paleontological resources are also found within its boundaries. The bluffs around Yorktown are composed of sedimentary rocks and deposits of the Yorktown Formation, a marine unit deposited approximately 4.9 to 2.8 million years ago. When the Yorktown Formation was being deposited, the shallow seas were populated by many species of invertebrates, vertebrates, and micro-organisms which have left body fossils and trace fossils behind. Corals, bryozoans, bivalves, gastropods, scaphopods, worms, crabs, ostracodes, echinoids, sharks, bony fishes, whales, and others were abundant. People have long known about the fossils of the Yorktown area. Beginning in the British colonial era, fossiliferous deposits were used to make lime and construct roads, while more consolidated intervals furnished building stone. Large shells were used as plates and dippers. Collection of specimens for study began in the late 17th century, before they were even recognized as fossils. The oldest image of a fossil from North America is of a typical Yorktown Formation shell now known as Chesapecten jeffersonius, probably collected from the Yorktown area and very likely from within what is now COLO. Fossil shells were observed by participants of the 1781 siege of Yorktown, and the landmark known as “Cornwallis Cave” is carved into rock made of shell fragments. Scientific description of Yorktown Formation fossils began in the early 19th century. At least 25 fossil species have been named from specimens known to have been discovered within COLO boundaries, and at least another 96 have been named from specimens potentially discovered within COLO, but with insufficient locality information to be certain. At least a dozen external repositories and probably many more have fossils collected from lands now within COLO, but again limited locality information makes it difficult to be sure. This paleontological resource inventory is the first of its kind for Colonial National Historical Park (COLO). Although COLO fossils have been studied as part of the Northeast Coastal Barrier Network (NCBN; Tweet et al. 2014) and, to a lesser extent, as part of a thematic inventory of caves (Santucci et al. 2001), the park had not received a comprehensive paleontological inventory before this report. This inventory allows for a deeper understanding of the park’s paleontological resources and compiles information from historical papers as well as recently completed field work. In summer 2020, researchers went into the field and collected eight bulk samples from three different localities within COLO. These samples will be added to COLO’s museum collections, making their overall collection more robust. In the future, these samples may be used for educational purposes, both for the general public and for employees of the park.
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Shenker, Moshe, Paul R. Bloom, Abraham Shaviv, Adina Paytan, Barbara J. Cade-Menun, Yona Chen et Jorge Tarchitzky. Fate of Phosphorus Originated from Treated Wastewater and Biosolids in Soils : Speciation, Transport, and Accumulation. United States Department of Agriculture, juin 2011. http://dx.doi.org/10.32747/2011.7697103.bard.
Texte intégralRésumé :
Beneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levelsBeneficial use of reclaimed wastewater (RW) and biosolids (BS) in soils is accompanied by large input of sewage-originated P. Prolonged application may result in P accumulation up to levels that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction that impair plant nutrition, increase P loss, and promote eutrophication in downstream waters. This study aims to shed light on the RW- and BS-P forms in soils and to follow the processes that determine P reactivity, solubility, availability, and loss in RW and BS treated soils. The Technion group used sequential P extraction combined with measuring stable oxygen isotopic composition in phosphate (δ18OP) and with 31P-NMR studies to probe P speciation and transformations in soils irrigated with RW or fresh water (FW). The application of the δ18OP method to probe inorganic P (Pi) speciation and transformations in soils was developed through collaboration between the Technion and the UCSC groups. The method was used to trace Pi in water-, NaHCO3-, NaOH-, and HCl- P fractions in a calcareous clay soil (Acre, Israel) irrigated with RW or FW. The δ18OP signature changes during a month of incubation indicated biogeochemical processes. The water soluble Pi (WSPi) was affected by enzymatic activity yielding isotopic equilibrium with the water molecules in the soil solution. Further it interacted rapidly with the NaHCO3-Pi. The more stable Pi pools also exhibited isotopic alterations in the first two weeks after P application, likely related to microbial activity. Isotopic depletion which could result from organic P (PO) mineralization was followed by enrichment which may result from biologic discrimination in the uptake. Similar transformations were observed in both soils although transformations related to biological activity were more pronounced in the soil treated with RW. Specific P compounds were identified by the Technion group, using solution-state 31P-NMR in wastewater and in soil P extracts from Acre soils irrigated by RW and FW. Few identified PO compounds (e.g., D-glucose-6-phosphate) indicated coupled transformations of P and C in the wastewater. The RW soil retained higher P content, mainly in the labile fractions, but lower labile PO, than the FW soil; this and the fact that P species in the various soil extracts of the RW soil appear independent of P species in the RW are attributed to enhanced biological activity and P recycling in the RW soil. Consistent with that, both soils retained very similar P species in the soil pools. The HUJ group tested P stabilization to maximize the environmental safe application rates and the agronomic beneficial use of BS. Sequential P extraction indicated that the most reactive BS-P forms: WSP, membrane-P, and NaHCO3-P, were effectively stabilized by ferrous sulfate (FeSul), calcium oxide (CaO), or aluminum sulfate (alum). After applying the stabilized BS, or fresh BS (FBS), FBS compost (BSC), or P fertilizer (KH2PO4) to an alluvial soil, P availability was probed during 100 days of incubation. A plant-based bioassay indicated that P availability followed the order KH2PO4 >> alum-BS > BSC ≥ FBS > CaO-BS >> FeSul-BS. The WSPi concentration in soil increased following FBS or BSC application, and P mineralization further increased it during incubation. In contrast, the chemically stabilized BS reduced WSPi concentrations relative to the untreated soil. It was concluded that the chemically stabilized BS effectively controlled WSPi in the soil while still supplying P to support plant growth. Using the sequential extraction procedure the persistence of P availability in BS treated soils was shown to be of a long-term nature. 15 years after the last BS application to MN soils that were annually amended for 20 years by heavy rates of BS, about 25% of the added BS-P was found in the labile fractions. The UMN group further probed soil-P speciation in these soils by bulk and micro X-ray absorption near edge structure (XANES). This newly developed method was shown to be a powerful tool for P speciation in soils. In a control soil (no BS added), 54% of the total P was PO and it was mostly identified as phytic acid; 15% was identified as brushite and 26% as strengite. A corn crop BS amended soil included mostly P-Fe-peat complex, variscite and Al-P-peat complex but no Ca-P while in a BS-grass soil octacalcium phosphate was identified and o-phosphorylethanolamine or phytic acid was shown to dominate the PO fraction.
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Fridman, Eyal, et Eran Pichersky. Tomato Natural Insecticides : Elucidation of the Complex Pathway of Methylketone Biosynthesis. United States Department of Agriculture, décembre 2009. http://dx.doi.org/10.32747/2009.7696543.bard.
Texte intégralRésumé :
Plant species synthesize a multitude of specialized compounds 10 help ward off pests. and these in turn may well serve as an alternative to synthetic pesticides to reduce environmental damage and health risks to humans. The general goal of this research was to perform a genetic and biochemical dissection of the natural-insecticides methylketone pathway that is specific to the glandular trichomes of the wild species of tomato, Solanumhabrochaites f. glabratum (accession PI126449). Previous study conducted by us have demonstrated that these compounds are synthesized de novo as a derivate pathway of the fatty acid biosynthesis, and that a key enzyme. designated MethylketoneSynthase 1 (MKS 1). catalyzes conversion of the intermediate B-ketoacyl- ACPs to the corresponding Cn-1 methylketones. The approach taken in this proposed project was to use an interspecific F2 population. derived from the cross between the cultivated lV182 and the wild species PIl26449. for three objectives: (i) Analyze the association between allelic status of candidate genes from the fatty acid biosynthesis pathway with the methylketone content in the leaves (ii) Perform bulk segregant analysis of genetic markers along the tomato genome for identifying genomic regions that harbor QTLs for 2TD content (iii) Apply differential gene expression analysis using the isolated glands of bulk segregant for identifying new genes that are involved in the pathway. The genetic mapping in the interspecific F2 population included app. 60 genetic markers, including the candidate genes from the FAS pathway and SSR markers spread evenly across the genome. This initial; screening identified 5 loci associated with MK content including the candidate genes MKS1, ACC and MaCoA:ACP trans. Interesting observation in this genetic analysis was the connection between shape and content of the glands, i.e. the globularity of the four cells, typical to the wild species. was associated with increased MK in the segregating population. In the next step of the research transcriptomic analysis of trichomes from high- and 10w-MK plants was conducted. This analysis identified a new gene, Methy1ketone synthase 2 (MKS2), whose protein product share sequence similarity to the thioesterase super family of hot-dog enzymes. Genetic analysis in the segregating population confirmed its association with MK content, as well as its overexpression in E. coli that led to formation of MK in the media. There are several conclusions drawn from this research project: (i) the genetic control of MK accumulation in the trichomes is composed of biochemical components in the FAS pathway and its vicinity (MKS 1 and MKS2). as well as genetic factors that mediate the morphology of these specialized cells. (ii) the biochemical pathway is now realized different from what was hypothesized before with MKS2 working upstream to I\1KS 1 and serves as the interface between primary (fatty acids) and secondary (MK) metabolism. We are currently testing the possible physical interactions between these two proteins in vitro after the genetic analysis showed clear epistatic interactions. (iii) the regulation of the pathway that lead to specialized metabolism in the wild species is largely mediated by transcription and one of the achievements of this project is that we were able to isolate and verify the specificity of the MKS1 promoter to the trichomes which allows manipulation of the pathways in these cells (currently in progress). The scientific implications of this research project is the advancement in our knowledge of hitherto unknown biochemical pathway in plants and new leads for studying a new family in plants (hot dog thioesterase). The agricultural and biotechnological implication are : (i) generation of new genetic markers that could assist in importing this pathway to cultivated tomato hence enhancing its natural resistance to insecticides, (ii) the discovery of MKS2 adds a new gene for genetic engineering of plants for making new fatty acid derived compounds. This could be assisted with the use of the isolated and verified MKS1 promoter. The results of this research were summarized to a manuscript that was published in Plant Physiology (cover paper). to a chapter in a proceeding book. and one patent was submitted in the US.