Dissertations / Theses on the topic 'Chemical traits'
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Fahmi, Romani. "The characterisation and optimisation of modified herbaceous grasses for identifying pyrolisis-oil quality traits." Thesis, Aston University, 2008. http://publications.aston.ac.uk/15303/.
Full textEsquivel, Patricia [Verfasser]. "Characterisation of Morphological and Chemical Traits of Costa Rican Fruits from Purple Pitaya (Hylocereus sp.) Genotypes / Patricia Esquivel." Aachen : Shaker, 2007. http://d-nb.info/1166511154/34.
Full textLi, Nana. "Male sexually selected traits of the barn swallow Hirundo rustica gutturalis in China." Thesis, Queen Mary, University of London, 2017. http://qmro.qmul.ac.uk/xmlui/handle/123456789/30714.
Full textJoffard, Nina. "Diversification des orchidées méditerranéennes : niches de pollinisation, évolution des traits floraux et taxonomie intégrative." Thesis, Paris Sciences et Lettres (ComUE), 2017. http://www.theses.fr/2017PSLEP066.
Full textInteractions with pollinators are part of orchids’ ecological niches and have played a role in their taxonomic and floral diversification. During this thesis, I have analysed the architecture of the orchid-pollinator network in the Euro-Mediterranean region and shown that similarity in pollination niches between orchids primarily depends on their spatio-temporal distribution, suggesting that orchid-pollinator interactions are more opportunistic than previously thought. Then, I have been interested in the role of pollinators in floral trait evolution in two orchid groups. I have shown a differentiation in floral traits of the three taxa of the Anacamptis coriophora group, probably caused and maintained by a process of divergent selection. Then, by mapping interactions with pollinators and floral odours on the phylogeny of the section Pseudophrys, I have shown that floral odour evolution is conditioned by pollinator-mediated selection and by phylogenetic constraints. Finally, I have developed an integrative taxonomic approach based on molecular, morphometric and chemical data in the genus Ophrys. With this approach, I have confirmed the taxonomic rank of the three species of the O. insectifera group and proposed to merge two species pairs among Pseudophrys. A better understanding of the factors that have shaped pollination niches and of the role of pollinators in floral trait evolution and speciation in Euro-Mediterranean orchids should allow us to improve the conservation of these emblematic species
Schweiggert, Ralf Martin [Verfasser]. "Characterisation of morphological and chemical traits of Costa Rican papaya (Carica papaya L.) fruit genotypes with special reference to their carotenoid bioavailability / Ralf Martin Schweiggert." Aachen : Shaker, 2014. http://d-nb.info/1049380339/34.
Full textPlans, Pujolràs Marçal. "Utilització de l'espectroscòpia d'infraroig com a eina per a la selecció i millora de la mongeta seca (Phaseolus vulgaris L.)." Doctoral thesis, Universitat Politècnica de Catalunya, 2014. http://hdl.handle.net/10803/283234.
Full textLa mongeta seca (Phaseolus vulgaris L.) és una de les lleguminoses de gra més consumides i produïdes arreu del món i amb un alt valor nutricional degut al seu elevat contingut proteic. La seva gran diversitat fa que existeixen milers d’entrades conservades en els bancs de llavors i centres de millora vegetal. L’avaluació química i sensorial d’aquestes entrades donaria informació molt valuosa per a programes de millora vegetal, però requereixen processos llargs i laboriosos que els fan poc apropiats quan cal caracteritzar un gran nombre de mostres. L’espectroscòpia d’infraroig pot ser una alternativa ja que, l’espectre de la mostra, que es reagistra en pocs segons i que necessita un mínim pretractament de la mostra, podria donar una estimació dels caràcters químics i sensorials. L’objectiu principal d’aquesta tesi és, doncs, obtenir models que permetin correlacionar l’espectre en l’infraroig amb els atributs sensorial de la mongeta i amb el contingut d'aquells components químics que semblen influir en aquests atributs. La tesi s’articula en tres treballs: l'anàlisi química de la pell de la mongeta (fibra dietètica, àcids urònics, cendres, calci i magnesi), l'anàlisi química del cotiledó (proteïna, midó, amilosa) i els atributs sensorials de la mongeta (aroma, gust, farinositat, percepció, rugositat i brillantor de la pell). Els principals resultats són: i) Per a la correcte predicció de la composició química de la pell, aquesta ha de ser separada de cotiledó i molturada a fi d’obtenir una mostra suficientment homogènia; ii) El contingut en calci, cendres i fibra diatètica de la pell de la mongeta es pot predir utilitzant l’espectre NIR; iii) Es possible obtenir models per a la predicció de proteïna, midó i amilosa utilitzant varies tecnologies IR, essent els millors models el obtinguts amb FT-NIR; iv) Els resultats obtinguts amb equips d'IR portàtils i els seus homòlegs de sobretaula tenen bondats similars ; v) Per a la correcta predicció dels atributs sensorial és necessari coure, deshidratar i molturar la mongeta abans d’obtenir l’espectre; vi) els espectres NIR van permetre estimar el gust, farinositat, brillantor de la pell i rugositat de la pell de la mongeta valorats per un panel de tastador però no l’aroma i la percepció de la pell; vii) Finalment, es possible utilitzar la tecnologia IR, sent una eina molt valuosa per a la caracterització de col·leccions molt nombroses de mostres, per la selecció i la millora.
Oliveira, Ana Paula Pessim de. "Crescimento e composi??o qu?mico-bromatol?gica do capim Tifton 85 (Cynodon spp) sob doses de nitrog?nio." Universidade Federal Rural do Rio de Janeiro, 2008. https://tede.ufrrj.br/jspui/handle/tede/579.
Full textCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
The effects of nitrogen (N) application on several structural and nutritional attributes of the plant canopy were evaluated. The studies were carried out at the Experimental Campus of the Rio de Janeiro Federal Rural University, Serop?dica-RJ, in area of Planosol Haplic occurrence, during the period of October 2006 to July 2007. Treatments consisted of five doses of N (0; 150; 300; 450 and 600 kg N-urea/ha) disposed in experimental units of 4 x 4 m using a entirely randomized block design. After a standardization cut, made 82 days after planting, it proceeded to the application of nitrogen fertilizer levels, half of which at 94 days, and the remaining at 139 days after the planting. Four studies had been carried through, which the results are presented in distinct chapters. In the first chapter the results of nitrogen fertilization were discussed in terms of soil covering, leaf area index (LAI) and solar radiation interception, during the four sequential cuts, between the months of February and July of 2007. Weekly evaluations were accomplished, between 10 and 40 days after cut. The LAI frequency of occurrence, plant height, green cover index and level of photosynthetically active radiation intercepted showed significant responses to N fertilization, according to a logistic pattern and also varied seasonally within each cut, evidencing different sensibility as indicators for structure and growth of the Tifton 85 sward. In the second study were evaluated the effect of N fertilization on biomass production and the efficiency in the use of N absorbed. For statistical analysis purposes, sampling data were clustered in two seasons: rainy season (February to April) and dry season (April to July). It was quantified in each cut date the production of green and dry mass, leaves and stem fraction, as well as the N content in each one of the vegetative fractions. This study showed that N fertilization icreased the dry matter production and stimulated the production of leaves and stems in both the seasons (rainy and dry). However, the nitrogen fertilization, per se, does not modify the partition of the dry mass produced by leaves and stems, and had no influence on efficiency of the pasture to produce dry matter per unit of N absorbed. The third study, of methodological character, aimed the validation of indirect procedures for estimate the functional relation between the green and dry mass and the LAI. The occurrence frequency and the index of green covering were tested as substitutes of IAF using simple correlation procedure. Although in this study has been observed the existence of a significant association among the the canopy attributes estimates associated to the leaf area and the forage production leaf area and forage production, additional studies are necessary to improve the reliability and accuracy of this estimates. Finally, in the last study, the influence of the nitrogen fertilization on nutritional value of the forage was evaluated. The crude protein, neutral detergent fiber, acid detergent fiber, lignin, cellulose and hemicelulose cotents were determined. The results showed that the addition of N improved the forage quality, increasing crude protein contents and decreasing fibrous fraction.
Foram avaliados os efeitos da aplica??o de nitrog?nio (N) sobre uma s?rie de atributos estruturais e nutricionais do dossel. Os estudos foram desenvolvidos no campo experimental da Universidade Federal Rural do Rio de Janeiro, munic?pio de Serop?dica- RJ, em ?rea de ocorr?ncia de Planossolo. O experimento foi conduzido sob regime de cortes, durante o per?odo de outubro de 2006 a julho de 2007. Foram estudadas cinco doses de N (0; 150; 300; 450 e 600 kg/ha) em diferentes ?pocas do ano. O experimento foi conduzido em blocos inteiramente casualizados. Foram feitos quatro estudos, cujos resultados s?o apresentados em cap?tulos distintos. No primeiro cap?tulo, os efeitos da aduba??o nitrogenada s?o discutidos em termos de cobertura do solo, ?ndice de ?rea foliar e intercepta??o da radia??o solar, no curso de quatro cortes seq?enciais, entre os meses de fevereiro e julho. As avalia??es foram realizadas, semanalmente, entre o 10o e o 40o dia ap?s o corte. Em cada corte, o ?ndice de ?rea foliar (IAF), a freq??ncia de ocorr?ncia, altura de planta, ?ndice de cobertura verde e o n?vel de radia??o fotossinteticamente ativa interceptada, responderam ? aduba??o nitrogenada, conforme um padr?o log?stico e variaram sazonalmente, evidenciando uma sensibilidade diversa como indicadores da estrutura e do crescimento da pastagem de Tifton 85. No segundo estudo foram abordadas as respostas relativas ? produ??o de biomassa sob aduba??o nitrogenada e a efici?ncia na utiliza??o do N absorvido. Para efeito de an?lise estat?stica, os dados das coletas foram agrupados em ?poca das chuvas (fevereiro a abril) e ?poca seca (abril a julho). Em cada data de corte foi quantificada a produ??o de massa verde e seca, a sua parti??o entre folhas e colmos + bainhas, assim como o teor de N em cada uma das partes vegetativas. Este estudo evidenciou que a aduba??o nitrogenada aumentou a produ??o de forragem, estimulando a produ??o de folhas e colmos tanto na ?poca chuvosa quanto na seca. Por outro lado, a aduba??o nitrogenada, per se, n?o modificou a parti??o da massa seca produzida por folhas e colmos, nem influenciou a efici?ncia com a qual a pastagem produz massa seca por unidade de nitrog?nio absorvido. O terceiro estudo, de cunho metodol?gico, objetivou a valida??o de procedimentos indiretos para a estimativa da rela??o funcional entre a massa verde e seca e o ?ndice de ?rea foliar da pastagem. Foram estudados a freq??ncia de ocorr?ncia e o ?ndice de cobertura verde como suced?neos do IAF, utilizando-se correla??o simples. Embora tenha sido observada a exist?ncia de um grau de associa??o significativo entre as estimativas de atributos ligados ? ?rea foliar e a produ??o de forragem, s?o necess?rios estudos adicionais para melhorar a confiabilidade e a acur?cia de tais estimativas. No quarto estudo foi estudada a influencia da aduba??o nitrogenada sobre o valor nutricional da forragem, sendo avaliados os teores de prote?na bruta, fibra em detergente neutro, fibra em detergente ?cido, lignina, celulose e hemicelulose. Os resultados obtidos mostraram que a adi??o de N melhorou a qualidade da forragem, aumentando os teores de prote?na bruta e reduzindo a fra??o fibrosa.
De, almeida Tania. "Impact d’une espèce ingénieure de l’écosystème et son utilisation en restauration écologique : Le cas de Messor barbarus (L.) dans les pelouses méditerranéennes Above- and below-ground effects of an ecosystem engineer ant in Mediterranean dry grasslands Harvester ants as ecological engineers for Mediterranean grassland restoration: impacts on soil and vegetation A trait-based approach to promote ants in restoration ecology." Thesis, Avignon, 2020. http://www.theses.fr/2020AVIG0358.
Full textThe main objective of this thesis was double: (i) to assess the impact of an ant species on its ecosystem, in order to (ii) deduce potential applications in the field of ecological restoration.Ants are among the most abundant organisms in terrestrial ecosystems and occupy a wide range of geographical areas. They play key ecological roles in many ecosystems as soil engineers, predators or regulators of plant growth and reproduction. However, the information collected locally is often fragmented and does not provide a complete overview of the impact of a species on its environment.Messor barbarus (L.), known to redistribute seeds and to modify the soil physico-chemical properties, is widespread in South-Western Europe, particularly in Mediterranean grasslands. Therefore, it may play a major role in the composition and structuring of these ecosystems, which are characterised by high biodiversity but whose abundance and surface area have decreased drastically in recent decades.Through a multi-compartment study, we confirmed the hypothesis that M. barbarus is an ecological engineer in Mediterranean grasslands. This species changes this habitat by modifying, as expected, soil physico-chemical properties. These modifications are associated with an increase in both biomass and heterogeneity of plant communities, as well as changes in above- and belowground fauna (abundance, occurrence and structure of communities). Messor barbarus profoundly changes trophic and non-trophic relationships within and between species and their habitat. The heterogeneity created locally by the activity of M. barbarus leads to a diversification of ecological niches within these grasslands.Despite their major role in the functioning of ecosystems, ants are rarely considered in restoration ecology. In our study site, corresponding to a dry grassland rehabilited after an oil leak and a soil transfer, M. barbarus contributed to accelerate the restoration of the soil physico-chemical properties but also of the seed bank in the medium term - seven years after the rehabilitation. These results make this species a good candidate for ecological engineering.In order to generalise the use of ants in restoration ecology, we propose a trait-based methodology for stakeholders. We evaluated the potential of ants in restoration ecology, then listed all the traits known to affect abiotic and biotic compartments and/or relevant to monitor the success of the restoration phase. The proposed methodology provides a first selection of potentially relevant species according to the restoration objectives
Roberts, D. "Physical conclusions? : an exploration of [dis]continuities in Thomas Vaughan's [al]chemical tracts." Thesis, University of Wales Trinity Saint David, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.683187.
Full textZhan, Tianyu. "Mesosphere and lower thermosphere neutral winds observations using rocket-released chemical trails at Poker Flat, Alaska." Connect to this title online, 2007. http://etd.lib.clemson.edu/documents/1202409881/.
Full textJackson, Duncan Edward. "The shortest path is the one you know : a behavioural, chemical and computational investigation of ant pheromone trails." Thesis, University of Sheffield, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.425621.
Full textHubert, Axelle. "Chemical and mineralogical signatures of oxygenic photosynthesis in Archean and Paleoproterozoic sediments." Thesis, Orléans, 2015. http://www.theses.fr/2015ORLE2053/document.
Full textThe evolution of oxygenic photosynthetic bacteria (OPB) is probably the most important biological event of Earth’s history since the emergence of life itself. The release of their by-product O2 in the environment, which was globally anoxic, fundamentally changed the face of the Earth and led to the development of complex life. However, the specific timing of this evolutionary step remains unclear. This study is based on the search for in situ chemical signatures of OPB at the microbial (μm) scale, within fossilized microbial photosynthetic mats in Archean and Paleoproterozoic sediments dated between 3.45 Ga and 1.88 Ga, i.e. spanning the anoxic Earth to the aftermath of the GOE. We used optical microscopy, Raman spectroscopy, SEM/EDS, EPMA, synchrotron radiation μ-XRF, and isotope analytical techniques. The μXRF results were improved by the use of a new sample preparation method and a new quantification method, both developed during this study.Results obtained by EPMA and μXRF show that, under certain depositional contexts, enrichment in lanthanides (such as Sm, La and Gd) in individual OPB cells, as well as a Cu enrichment in diagenetic pyrites formed in association with OPB, may represent chemical signatures of OPB. I propose that OPB evolved sometime between 3.33 Ga and 2.98 Ga. Also, I argue that elemental techniques such as EPMA and μ-XRF are the most suitable techniques to find chemical signatures of OPB and constrain the timing of their emergence
Ferreira, Martins Vânia. "Air quality in subway systems: particulate matter concentrations, chemical composition, sources and personal exposure." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/399787.
Full textDecin, L., A. M. S. Richards, T. J. Millar, A. Baudry, Beck E. De, W. Homan, N. Smith, de Sande M. Van, and C. Walsh. "ALMA-resolved salt emission traces the chemical footprint and inner wind morphology of VY Canis Majoris." EDP SCIENCES S A, 2016. http://hdl.handle.net/10150/621992.
Full textCANTAGALLO, MARIA I. C. "Aplicacao da cronocoulometria a determinacao de tracos de uranio com base na reducao catalitica de nitrato em eletrodo de mercurio." reponame:Repositório Institucional do IPEN, 1988. http://repositorio.ipen.br:8080/xmlui/handle/123456789/9920.
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Tese (Doutoramento)
IPEN/T
Instituto de Quimica, Universidade de Sao Paulo - IQ/USP
Thibert, Valérie. "Développement d'outils miniaturisés pour l'analyse de traces dans les matrices biologiques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://pastel.archives-ouvertes.fr/pastel-00650138.
Full textBohnke, Isabelle. "Étude expérimentale et théorique des traitements thermiques du bois. Caractérisation physico-mécanique des bois traités." Phd thesis, Ecole Nationale Supérieure des Mines de Saint-Etienne, 1993. http://tel.archives-ouvertes.fr/tel-00844044.
Full textDuthie, Carol-Anne. "Individual and epistatic genetic effects of quantitative trait loci affecting growth, feed intake, body composition and meat quality in pigs." Thesis, University of Edinburgh, 2009. http://hdl.handle.net/1842/3875.
Full textKATSUOKA, LIDIA. "Agentes complexantes no controle analitico de tracos de fluoreto por eletrodo ion-seletivo." reponame:Repositório Institucional do IPEN, 1996. http://repositorio.ipen.br:8080/xmlui/handle/123456789/10451.
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Dissertacao (Mestrado)
IPEN/D
Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP
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.
Full textKusumoto, Tamon. "Radial electron fluence around ion tracks as a new physical concept for the detection threshold of PADC detector." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAE046/document.
Full textThe structure and formation process of latent tracks in poly(allyl diglycol carbonate), PADC, have been examined using the combination of FT-IR spectrometry and a Monte Carlo simulation. The generation amount of OH groups is almost equivalent to the loss amount of ether. An important role of the secondary electron that the carbonyl can be broken only when more than two electrons pass through a single repeat unit is clarified by experiments using low LET radiations. Results of high energy protons lead us to the elucidation of the difference between etchable and un-etchable tracks. Based on these results, a new physical concept of Radial Electron Fluence around Ion Tracks, which is defined as the number density of secondary electron that pass through the cylinder surface with a certain radius is proposed for the detection threshold of PADC using Geant4-DNA. Obtained knowledge is helpful to find appropriate molecule arrangements for new etched track detector with desired sensitivities
Shillito, Lisa Marie. "Investigating traces of activities, diet and seasonality in middens at Neolithic catalhoyuk : An integration of microstratigraphic, phytolith and chemical analyses." Thesis, University of Reading, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.529968.
Full textBichon, Emmanuelle. "Challenge de l’analyse de dangers chimiques à l’état d’ultra-traces en matrices biologiques complexes." Thesis, Nantes, Ecole nationale vétérinaire, 2016. http://www.theses.fr/2016ONIR089F/document.
Full textThe study of the link between Human exposure tochemical substances (notably via his food the intake) and Health, is a major concern in our society and poses many challenges. We endeavoured to address one of them by producing reliable analytical data on foodstuffs and human biological fluids contamination. The development of analytical methods based on breakthrough technologies, capable of challenging theemerging (e.g. brominated flame retardants) or historical compounds measurement but through the prism of sensitivity and high throughput (e.g. steroids,organochlorine pesticides, dioxins andpolychlorobiphenyls), was at the heart of our work.Using a GC/APCI/MS with a triple quadripole systememerged as a favorable choice as our evaluations progressed. The association of gas chromatography and atmospheric pressure chemical ionisation brought in a remarkable gain in terms of selectivity, compared to the approaches traditionally selected in this field, andauthorized ultra-trace exploration in complex biologicalmatrices. This geometry allowed us to innovate by performing fast separations on an ultra-short 2.5 mcolumn. Besides, the mass analyser scan speed and high sensitivity gave us access to a reliable and multiparameters quantitative analysis. This work opens up excellent perspectives for the production of expanded external and internal exposure data to meet the future challenges surrounding Human exposome characterisation
Ruch, Claude. "Analyse d'elements traces par fluorescence x : nouveaux developpements." Université Louis Pasteur (Strasbourg) (1971-2008), 1986. http://www.theses.fr/1986STR13107.
Full textGhosn, Micheline. "Chemical contamination in different marine organisms along the Lebanese coast : Environmental implications and health risks." Thesis, Littoral, 2019. http://www.theses.fr/2019DUNK0552.
Full textGlobal food fish consumption has been in continuous increase and fishery products have become some of the most traded items in the world. However, the quality of these products is becoming an issue of concern to human health with the increase of anthropogenic activities threatening marine coastal ecosystems. Therefore, despite the well-known health benefits of fishery products, their consumption may be a route of human exposure to different kinds of chemical contaminants including trace elements. In this context, evaluating the contamination levels in these products and the risks they may engender to human health proves to be a necessity in the absence of local guidelines and monitoring programs. Thus, the thesis has 2 main objectives: i) the evaluation of environmental quality through marine organisms and, ii) the assessment of health risks related to the consumption of a selection of fishery products.The first objective was to study the levels of metallic contaminants (20 trace elements) in six marine species from different trophic levels of a food web (algae, mussel, shrimp and fish), representative of Lebanese coastal waters. The results showed that species accumulated metals differently underlining the importance of a multi-specific approach to reflect the contamination level of a certain site. Inter-site variations have been found mainly during the rainy period of the year while they were less prominent during the dry season, highlighting the effect of land-based sources and riverine effluents on the marine coastal area. Levels of trace elements in the muscles and edible tissues in species from our study, were similar to the ones reported in the Eastern Mediterranean (Levantine Basin) whereas livers showed higher levels compared to other studies suggesting that the Lebanese coast is exposed to strong environmental pressure. The second objective was to evaluate the health risks related to the consumption of different fishery products sampled along the Lebanese coast. In this prospect, five commonly consumed local species belonging to different compartments of the food chain, (1 bivalve, 1 crustacean and 3 fish species) sampled from three sites with different levels of anthropogenic pressures were selected. The samples were all analyzed for their content of trace elements. Metals such as mercury (Hg) are found in several chemical forms, the most toxic form being methylmercury (MeHg). The main route of human exposure to MeHg is the consumption of fishery products. That’s why, a method for the speciation of mercury in fishery products by HPLC-ICP-MS was optimized and validated based on an accuracy profile. The results showed that the levels of trace elements and MeHg in the selected species were all below the allowed maximum levels set by the European commission and so their consumption is not likely to cause any adverse effects to human health
CABANE, Nicolas. "Sols traités à la chaux et aux liants hydrauliques : Contribution à l'identification et à l'analyse des élèments perturbateurs de la stabilisation." Phd thesis, Université Jean Monnet - Saint-Etienne, 2004. http://tel.archives-ouvertes.fr/tel-00010521.
Full textentreprises utilisatrices des sols traités et productrices des agents de traitement se sont associées pour lancer des travaux de recherches destinés à comprendre les causes des défaillances.
Cette étude a tout d'abord établi un modèle de l'enchaînement des mécanismes qui conduisent à une stabilisation des sols :
- la chaux permet la floculation des argiles d'où la formation de grumeaux lors du malaxage. Ce grumeau constitue l'entité caractéristique du sol.
- le ciment forme une coque enrobant les grumeaux. Le compactage permet la coalescence de ces pâtes en formant un réseau continu. Le durcissement du ciment permet l'acquisition des caractéristiques mécaniques.
- l'excès de chaux en milieu basique conduit à la formation d'une seconde génération d'hydrates calciques (C-S-H) par réaction pouzzolanique aux dépens des argiles. Le développement des hydrates permet la rigidification du coeur du grumeau et l'augmentation correspondante des résistances mécaniques sur plusieurs années.
Les perturbations rencontrées lors des chantiers peuvent s'interpréter comme des écarts à ce modèle:
- écarts d'ordre microstructural ; dans les sols micacés, le comportement mécanique de ces matériaux est contrôlé par la présence de paillettes de micas dans la coque et de
fragments aplatis de roche au sein des grumeaux.
- écarts d'ordre physico-chimique ; des composés solubles interfèrent avec les liants :
- le soufre favorise le développement d'ettringite selon des faciès qui dépendent de la spéciation du soufre et de la perméabilité du grumeau.
- les matières organiques ralentissent l'hydratation du ciment et piègent les ions calcium et hydroxyle et sont ainsi responsables des résistances mécaniques insuffisantes
Ayant identifié et analysé les mécanismes des perturbations, nous nous sommes attachés à proposer des essais simples et fiables de caractérisation démontrant rapidement la présence de
ces agents perturbateurs au sein des sols :
- par la caractérisation de la morphologie des particules
- par le retard de début de prise de pâtes pures de ciment gâchées avec des jus extraits de sols pour les matières organiques.
Sarazin, Cédric. "Recherche et identification de traces d'explosifs sur des prélèvements après attentat. Application de l'électrophorèse capillaire à cette problématique." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2011. http://pastel.archives-ouvertes.fr/pastel-00657517.
Full textAnrès, Philippe. "Développement de nouvelles méthodologies de préconcentration électrocinétique in-situ en électrophorèse capillaire pour l'analyse de traces." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2012. http://pastel.archives-ouvertes.fr/pastel-00744659.
Full textNeami, Abdulwahid al. "Analyse quantitative des impuretes presentes a l'etat de traces dans cdte." Strasbourg 1, 1988. http://www.theses.fr/1988STR13206.
Full textLosno, Rémi. "Chimie d'éléments minéraux en traces dans les pluies méditerranéennes." Phd thesis, Université Paris-Diderot - Paris VII, 1989. http://tel.archives-ouvertes.fr/tel-00814327.
Full textRichard, Manuel. "Analyse de la composition élémentaire de Pecten maximus par HR-ICP-MS Element 2 : développements méthodologiques et interprétations écologiques." Phd thesis, Université de Bretagne occidentale - Brest, 2009. http://tel.archives-ouvertes.fr/tel-00458100.
Full textSkrzypczak-Bonduelle, Audrey. "Les premières traces de vie sur Terre : une approche spectroscopique et mimétique du problème." Phd thesis, Paris 6, 2005. http://pastel.archives-ouvertes.fr/pastel-00001717.
Full textHeimburger, Robert. "Determination d'elements traces dans les poudres par fluorescence x a dispersion d'energie." Université Louis Pasteur (Strasbourg) (1971-2008), 1987. http://www.theses.fr/1987STR13052.
Full textTanguy, Virginie. "Spéciation colloïdale des éléments traces métalliques en milieu estuarien." Phd thesis, Université de Bretagne occidentale - Brest, 2011. http://tel.archives-ouvertes.fr/tel-00708258.
Full textBayle, Marie-Laure. "Effet de l'exercice sur les concentrations d'androgènes chez la jeune femmeAnalyse de traces dans les urinesMise au point d'une phase d'extraction à base d'empreinte moléculaire." Phd thesis, Université Claude Bernard - Lyon I, 2008. http://tel.archives-ouvertes.fr/tel-00370944.
Full textUne amélioration de l'extraction a été ensuite proposée par la synthèse d'une phase stationnaire polymérique à impression moléculaire (MIP). Le MIP a été synthétisé dans des conditions favorisant la mise en place d'interactions non covalentes avec l'androstérone, ces mêmes interactions étant ensuite mises à contribution dans la rétention de la norandrostérone et de ses isomères lors de la percolation d'un échantillon sur la phase d'extraction. Conduisant à des résultats prometteurs, la technique semble intéressante en vue de l'analyse de traces de métabolites de la nandrolone grâce à une amélioration de la sélectivité de la méthode globale d'analyse
Бодня, Оксана Юріївна. "Мутаційна мінливість індукована хімічними мутагенами в М2 у редьки сорту Факел." Магістерська робота, ЗНУ, 2020. https://dspace.znu.edu.ua/jspui/handle/12345/1399.
Full textUA : Дипломна робота виконана на 75 сторінки друкованого тексту, містить 2 таблиці та 9 рисунків. Під час написання роботи було використано 50 літературних джерел, одне з них іноземною мовою. Об'єктом дослідження був сорт редьки олійної Факел, оброблений хімічним мутагеном та його вихідна форма. Актуальність проблеми – шляхом індукованого мутагенезу був отриманий цінний генетичний матеріал у багатьох сільськогосподарських культур. Окрім інших були отримані мутації, що проявляються на ранніх стадіях росту та розвитку, у тому числі з різним проявом на сім'ядольних листках. Ці мутації можуть бути використані як маркерні ознаки в селекції культури. Так як тема стосовно редьки олійної мало досліджена, то дослідження у вказаному напрямку являються необхідними і актуальними. Мета даної роботи полягала у спостереженні та виділенні нових груп мутацій під впливом етилметансульфонату під час проходження основних фаз вегетації культури та встановлення частоти виділених мутацій. В результаті дослідів у другому мутантному поколінні були отримані такі мутації: мутації з порушенням синтезу хлорофілу, мутації сім’ядольних та справжніх листків, мутації структури стебла та гілок, мутації квітки, мутації фізіологічних ознак. У 10 сімей контролю мутаційні зміни не виявлені. Загальна частота виділених мутацій склала 28,2 %. Слід зазначити, що ця частота мутацій є попередньою, оскільки остаточну частоту мутацій у другому мутантному поколінні можна встановити лише після перевірки успадкування виділених мутацій у наступному поколінні. Отже, використання хімічного мутагену етилметансульфонату у концентрації 0,01% було ефективним для одержання мутацій різного типу, у тому числі тих, що виявляються на ранніх стадіях росту та розвитку редьки олійної. У сучасному рослинництві редька олійна є відносно новою культурою, але вже активно починає використовуватись в сільському господарстві. Найбільше поширення культура отримала як сидерат. Але також знайшла своє місце застосування в харчовій промисловості, косметології, фармакології, кулінарії, виробництві біопалива. Тому будь-які досліди, пов’язані з отриманням цінного генетичного матеріалу, являються дуже необхідними. Саме в цьому і є значущість і новизна даної роботи.
EN : The Degree work is completed on 75 pages of printed text, contains 2 tables and 9 figures. During the writing were used 50 literary sources, one of them in a foreign language. The object of the research was a sort of oilseed radish Torch treated with a chemical mutagen and its original form. The topicality of the problem - by induced mutagenesis has been obtained valuable genetic material in many agricultural crops. Among others were obtained mutations that appear themselves in the early stages of growth and development, including various manifestations on cotyledons leaves. These mutations can be used as marker features in culture selection. As the topic of oilseed radish is poorly explored, research in this direction is necessary and relevant. The purpose of this work was to observe and selection new groups of mutations under the influence of ethyl methanesulfonate during the main phases of vegetation. In the second mutant generation as a result of experiments were received the following mutations: mutations with impaired chlorophyll synthesis, mutations of cotyledons leaves and true leaves, mutations of the structure of the stem and branches, mutations of the flower, mutations of physiological features. In 10 control families mutational changes were not detected. The overall frequency of isolated mutations was 28.2%. It should be noted that this mutation frequency is preliminary, because the final mutation frequency in the second generation can be established only after checking the inheritance of isolated mutations in the next generation. Therefore, the use of a chemical mutagen of ethyl methanesulfonate at a concentration of 0.01% was effective for obtaining mutations of various types, including those found in the early stages of growth and development of oil radish. In modern plant growing, oilseed radish is a relatively new crop, but it is already actively used in agriculture. Culture was most widely used as a siderate. But it has also found its application in food, cosmetology, pharmacology, cooking and production of biofuel. Therefore, any experiments related to obtaining valuable genetic material are very necessary. That is the significance and novelty of this work.
Dietrich, Elodie. "Synthèse et études physico-chimiques de verres bioactifs denses et poreux.Applications en tant que biomatériaux en sites osseux." Phd thesis, Université Rennes 1, 2008. http://tel.archives-ouvertes.fr/tel-00344630.
Full textMohsen, Yehya. "Conception et caractérisation d'une plate-forme microfluidique pour la détection sélective de traces d'un produit de dégradation du TNT dans l'atmosphère." Phd thesis, Université de Franche-Comté, 2013. http://tel.archives-ouvertes.fr/tel-00943211.
Full textPiazzon, Nelly. "Characterization and detection of traces of energetic materials by Nanocalorimetry." Phd thesis, Université de Haute Alsace - Mulhouse, 2010. http://tel.archives-ouvertes.fr/tel-00702242.
Full textVeschambre, Sophie. "Caractérisation et quantification des Eléments Traces Métalliques dans les dépôts et les particules atmosphériques de la vallée d'Aspe - Mise en place d'indicateurs de la Qualité de l'Air." Phd thesis, Université de Pau et des Pays de l'Adour, 2006. http://tel.archives-ouvertes.fr/tel-00118082.
Full textLa vallée d'Aspe présente un niveau de contamination spécifique des zones éloignées des émissions anthropiques et les contaminants métalliques identifiés sont le Cd, Sb, Zn, Cu, Pb et Sn. Dans sa partie basse, les indicateurs de la qualité de l'air présentent une contribution des contaminants (i) liée aux émissions locales des combustions domestiques, à la pratique saisonnière de l'écobuage et au trafic routier, et (ii) aux sources anthropiques régionales de l'incinération des déchets ménagers, de l'industries métallurgique et des centres urbains. Dans sa partie haute, la vallée est soumise significativement, d'une part, à l'érosion éolienne et, d'autre part, à la contribution des sources du transport à grande échelle de l'hémisphère Nord. La caractérisation des ETM et des rapports isotopiques du plomb dans le tunnel du Somport indique (i) que le trafic routier émet significativement du Cu, Sb, Zn et Ba et (ii) bien que Pb présente de faibles émissions sa composition isotopique montre une source faiblement radiogénique du trafic routier. Toutefois, la faible circulation des véhicules dans la vallée d'Aspe ne permet pas de mettre évidence une contamination significative provenant des émissions du trafic routier.
Benabdallah, Mohammed. "Spéciation de l'étain en traces dans l'environnement aquatique par spectrophotométrie d'absorption atomique électrothermique." Pau, 1987. http://www.theses.fr/1987PAUU3026.
Full textKouzayha, Abir. "Développement des méthodes analytiques pour la détection et la quantification de traces des HAP et de pesticides dans l'eau. Application à l'évaluation de la qualité des eaux libanaises." Phd thesis, Université Sciences et Technologies - Bordeaux I, 2011. http://tel.archives-ouvertes.fr/tel-00786974.
Full textClochard, Marie-Claude. "Des polymérisations classiques en solution aux polymérisations radio-induites contrôlées en milieu confiné." Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00823555.
Full textROGER, BERTRAND. "Repartition et localisation des metaux traces dans les sediments : application a l'estuaire de la loire." Nantes, 1987. http://www.theses.fr/1987NANT2021.
Full textSmee, Delbert Lee. "The Ecology of Yikes! Environmental Forces Alter Prey Perception of Predators." Diss., Connect to this title online, 2006. http://etd.gatech.edu/theses/available/etd-05082006-213823/.
Full textTitle from PDF t.p. (viewed on Oct. 28, 2006). Marc Weissburg, Committee Chair ; Mark Hay, Committee Member ; Lin Jiang, Committee Member ; David Dusenbery, Committee Member ; Don Webster, Committee Member. Includes bibliographical references (p. 115-122).
Menou, Sophie. "Comparaison de méthodes d'analyses de traces de pesticides organiques dans les productions végétales, par chromatographies et immunodosages (ELISA)." Angers, 1995. http://www.theses.fr/1995ANGE0005.
Full textZaharia, Alexandra. "Identification des motifs de voisinage conservés dans des contextes métaboliques et génomiques." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS275/document.
Full textThis thesis fits within the field of systems biology and addresses a problem related to heterogeneous biological networks. It focuses on the relationship between metabolism and genomic context through a graph mining approach.It is well-known that succeeding enzymatic steps involving products of genes in close proximity on the chromosome translate an evolutionary advantage in maintaining this neighborhood relationship at both the metabolic and genomic levels. We therefore choose to focus on the detection of neighboring reactions being catalyzed by products of neighboring genes, where the notion of neighborhood may be modulated by allowing the omission of several reactions and/or genes. More specifically, the sought motifs are trails of reactions (meaning reaction sequences in which reactions may be repeated, but not the links between them). Such neighborhood motifs are referred to as metabolic and genomic patterns.In addition, we are also interested in detecting conserved metabolic and genomic patterns, meaning similar patterns across multiple species. Among the possible variations for a conserved pattern, the presence/absence of reactions and/or genes may be considered, or the different order of reactions and/or genes.A first development proposes algorithms and methods for the identification of conserved metabolic and genomic patterns. These methods are implemented in an open-source pipeline called CoMetGeNe (COnserved METabolic and GEnomic NEighborhoods). By means of this pipeline, we analyze a data set of 50 bacterial species, using data extracted from the KEGG knowledge base.A second development explores the detection of conserved patterns by taking into account the chemical similarity between reactions. This allows for the detection of a class of conserved metabolic modules in which neighboring genes are involved
Hill, Jennifer Marie. "Predator biomass and habitat characteristics affect the magnitude of consumptive and non-consumptive effects (NCEs): experiments between blue crabs, mud crabs, and oyster prey." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/41172.
Full textLouis, Yoann. "Mise au point d'une systématique de caractérisation des interactions Matière Organique Naturelle Dissoute (MOND) – Contaminants métalliques." Phd thesis, Université du Sud Toulon Var, 2008. http://tel.archives-ouvertes.fr/tel-00410142.
Full textBounaix, Fabrice. "Etude et réalisation d'un spectromètre haute sensibilité à diode laser pour la mesure de traces de gaz : application à la détection de la vapeur d'eau." Grenoble 1, 1993. http://www.theses.fr/1993GRE10018.
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