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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
581

Etude et développement d'une méthode de recherche pour les sources de contamination chimique des pompes à vide entre les équipements de EUV / Study and development of a research method of a chemical contamination source of vacuum pumps on EUV equipments

Vinci, Andréa 11 July 2013 (has links)
Ce travail présente l’étude d'une méthode de recherche utilisable en milieu industriel dessources de contamination chimique des pompes à vide équipant les lithographes EUV. Cetravail porte sur la problématique d’une éventuelle contamination carbonée introduite par lesystème de pompage et, notamment, par la turbine et le stator.A partir d’une caractérisation détaillée par chromatographie et spectroscopie dephotoémission de la contamination résiduelle issue du procédé de production, une procédured’analyse par spectrométrie de masse en phase gazeuse (RGA) utilisable en milieu industriel aété mise en oeuvre. En particulier, la possibilité de varier la température de l’échantillonpendant la mesure permet de caractériser la contamination carbonée résiduelle en étudiant lesprocédés physico-chimiques qui en sont à l’origine.Après avoir démontré l’efficacité du nettoyage final à éliminer les résidus des huiles de coupet avoir identifié la contamination organique résiduelle comme résidu du seul procédé denettoyage industriel, une copie « in vitro » de ce nettoyage a été développée : cela a permis demieux le caractériser en étudiant l’impact de plusieurs paramètres.L’influence de la concentration de lessive et de la procédure de séchage sur la contaminationcarbonée résiduelle a ainsi été étudiée. Une analyse de la contamination en phase gazeuse(RGA et TD-GCMS) ainsi qu’une caractérisation XPS de la surface des échantillons ont étéfaites. L’analyse de l’ensemble de ces résultats a permis d’établir un lien direct entre laconcentration de lessive utilisée et la contamination organique résiduelle. De plus,l’importance d’un séchage à haute température a été démontrée en mettant en évidence laprésence de plusieurs facteurs qui contribuent à la contamination résiduelle. / This work presents the study of a research method of the contamination sources of EUVLturbo molecular pumps, suitable for the industrial environment. This study deals with theproblem of a possible carbon contamination due to the pumping system and in particular tothe rotor and the stator.After a detailed characterisation of the production process residual contamination by TDGCMS/FID and XPS, a RGA procedure suitable for industrial environment has beendeveloped. The possibility to change the sample temperature during the measure lets tocharacterise the residual carbon contamination by investigating its primal physic-chemicalphenomena.The identification of the whole production process residual contamination demonstrates theefficacy of the industrial cleaning step to clean lubricants residuals. In order to bettercharacterise the cleaning step residual contamination, we developed an “in vitro” copy of theindustrial cleaning step.Thanks to the temperature variable RGA analysis of the residual contamination, we couldpoint out several contributions to carbon contamination and we could connect thesecontributions to different cleaning parameters.Detergent concentration as well as different drying procedure impact on residual carboncontamination has been studied. RGA and TD-GCMS/FID analysis as well as XPS surfacecharacterization have been performed. These analyses show a direct connection between thedetergent concentration used in the cleaning step and the residual carbon contamination.Furthermore, the importance of a high temperature drying step has been demonstrated.
582

Qualidade microbiológica de águas minerais em garrafas individuais comercializadas em Araraquara /

Dias, Maria Fernanda Falcone. January 2008 (has links)
Orientador: Adalberto Farache Filho / Banca: Maria da Penha Longo Mortatti Catanozi / Banca: Wellington Cyro de Almeida Leite / Resumo: Com a dúvida sobre a qualidade da água de abastecimento público, o cidadão passou a utilizar a água mineral com maior intensidade. Para atender a esta demanda as indústrias aumentaram a produção, novas empresas surgiram e também os falsários. Assim, é necessário conhecer-se a qualidade esperada e paga pelo consumidor nesse produto, realmente existe. O objetivo desta pesquisa foi avaliar aspectos de qualidade microbiológica em amostras de água mineral natural, não carbonatada, em garrafas individuais de 330mL a 600mL, das diversas marcas comercializadas em supermercados na cidade de Araraquara-SP. Foram utilizadas sessenta e nove amostras provenientes de dezessete marcas. As amostras foram adquiridas aleatoriamente, em épocas e estabelecimentos diferentes para que fossem originadas de lotes diversos. Para análise de coliformes totais e coliformes fecais/E. coli utilizou-se a técnica de substratos cromogênicos; para enterococos e Pseudomonas aeruginosa foram utilizadas as técnicas de tubos múltiplos específicas; para contagem de bactérias heterotróficas, foi utilizada a técnica de cultivo em profundidade. Todas as amostras de todas as marcas (100%) apresentaram ausência de coliformes fecais/E.coli, duas amostras (2,9%) de uma marca (5,9%) apresentaram contaminação por coliformes totais, duas amostras (2,9%), de duas marcas (11,8%) apresentaram contaminação por enterococos, três amostras (4,3%) de duas marcas (11,8%) apresentaram Pseudomonas aeruginosa e quarenta amostras (58%) de doze marcas (70,6%) apresentaram contagens acima de 500 UFC/mL para bactérias heterotróficas. Verificou-se que, das sessenta e nove amostras analisadas (100%) apenas seis (8,7%) apresentaram-se contaminadas com um ou mais dos indicadores especificados pela legislação brasileira para águas minerais. Entretanto, considerando os padrões para água mineral e o padrão...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: With the doubt on the water quality in public supplying, the citizen started to use the mineral water with larger intensity. For attend this demand the factory had increased the production, new companies had appeared and also the falsifiers. Thus, it's necessary to know if the quality waited and paid for the consumer in this product, really exists. The objective of the research was to evaluate aspects of microbiological quality in natural mineral water samples, not carbonated, in individual bottles of 330mL to 600mL, of the diverse marks commercialized in supermarkets in the city of Araraquara-SP. Sixty nine samples proceeding from seventeen marks had been used. The samples had been acquired aleatory, at different times and establishments for that they were originated from diverse lots. For analysis of fecal coliform/E. coli and total used it cromogenic substrate technique; for enterococcus and for Pseudomonas aeruginosa was used the technique of multiple tube specific; for counting of heterotrophic bacteria, was used the technique of culture in depth. All the samples of all the marks (100%) had presented absence for fecal coliform/E.coli., two samples (2.9%) of one mark (5.9%) had presented contamination for total coliform, two samples (2.9%), of two marks (11.8%) had presented contamination for enterococcus, three samples (4.3%) of two marks (11.8%) had presented Pseudomonas aeruginosa, and forty samples (58%) of twelve marks (70.6%) had presented counting above of 500 CFU/mL for heterotrophic bacteria. It was verified that, of the sixty nine analyzed samples (100%), only six (8.7%) had been presented contaminated with one or more than the pointers specified for the Brazilian legislation for mineral waters used in this research. However, considering the standards for mineral water and the standard for heterotrophic bacteria established by the legislation for water of human consumption...(Complete abstract click electronic access below) / Mestre
583

Avaliação do impacto ambiental e caracterização geoquímica de contaminantes em solo e água subterrânea na área do aterro de resíduos industriais da UTRESA na região do Vale dos Sinos, em Estância Velha, RS

Augustin Junior, Pedro Valter January 2011 (has links)
A contaminação de resíduos industriais é um grande problema ambiental relacionado ao desenvolvimento industrial e urbano atual. A região do Vale dos Sinos, RS tem um histórico preocupante no gerenciamento e na destinação final de resíduos industriais ali gerados. Este estudo foi realizado na Central de resíduos da UTRESA, no município de Estância Velha, e teve como objetivo o diagnóstico ambiental e a caracterização do comportamento geoquímico de contaminantes em solo e águas subterrâneas. A metodologia do estudo consistiu no mapeamento e caracterização geológica e hidrogeológica, instalação de poços de monitoramento e sondagens, amostragens de chorume, solo e águas subterrâneas e superficiais, análises físico-químicas de chorume, água e solo, ensaios de lixiviação e difratometria de raios-X em solo, ensaios de slug, diagnóstico ambiental, avaliação de risco e proposta de remediação da área de estudo. Foram instalados 25 poços de monitoramento, coletadas e analisadas 73 amostras (chorume, solo e águas). Os resultados obtidos mostram ampla contaminação do solo e da água subterrânea na área de influência do aterro de resíduos industriais da UTRESA, com intensidade variada nos diferentes contaminantes. Cromo, cloreto e nitrogênio amoniacal apresentam os níveis mais elevados de contaminação, o que reflete o maior conteúdo registrado nas amostras de chorume analisadas. Hidrocarbonetos de petróleo, cianetos e mercúrio exibem contaminações de baixa intensidade com ampla distribuição. Chumbo, cobre e bário, por outro lado, registram contaminação fraca e restrita a poucos locais. A contaminação do solo é registrada principalmente na zona subsaturada do aquífero, nos locais de convergência das águas pluviais situadas a nordeste e sul das células de deposição de resíduos, o que reflete a disseminação preferencial dos contaminantes pelo fluxo superficial seguido de infiltração no solo. Este processo de transporte de contaminação implica, também, em alto risco de contaminação das águas superficiais dos corpos receptores adjacentes. Os resultados dos ensaios de lixiviação indicam fraco potencial de contaminação das águas subterrâneas. A degradação ambiental registrada no local decorre das condições inadequadas de disposição e confinamento dos resíduos em células construídas a margem das normas técnicas, não atendendo as especificações de impermeabilização de base e topo e no dimensionamento dos taludes. / Contamination of industrial wastes represent a great environmental problem related to industrial and urban development. Historically the Vale dos Sinos region has adopted inadequate procedures in the management and final disposal of its industrial waste. This study was realized in the UTRESA landfill area to do an environmental diagnostic and to characterize the geochemical behavior of contaminants in soils and groundwater.The study was performed by geological and hydrogeological mapping, installation of monitoring wells and borings, sampling of landfill leachate, soil, groundwater and surface water, physical-chemical analysis of landfill leachate, water and soil, leaching tests and X-ray diffraction on the soil, slug tests, environmental diagnostic, risk evaluation and proposed remediation for the studied area. Twenty five monitoring wells were installed and were collected and analyzed 73 samples (landfill leachate, soil and waters). The results show widespread contamination of soil and groundwater in the influence area of UTRESA industrial waste landfill, with varying intensity in different contaminants. Chromium, chloride and ammonium have higher levels of contamination, which reflects the highest content recorded in the manure samples analyzed. Petroleum hydrocarbons, cyanide and mercury contamination exhibit low intensity with a wide distribution. Lead, copper and barium, on the other hand, show low contamination restricted to a few locations. Soil contamination is recorded mainly in the vadose zone of the aquifer, at the convergence locals of stormwater situated to the northwest and south of the waste disposal cells, showing the preferential spread of contaminants by surface flow followed by soil infiltration. This transport process of contaminants also results in high risk of contamination of adjacent streams. The results of leaching tests indicate low potential for groundwater contamination by dessortion of metals from the soil. Environmental degradation registered on the site results from the inadequate conditions of disposal and confinement of waste in the cells constructed without complying the technical standards.
584

Estudo da ocorrência de compostos arseniais, mercuriais e selênio em cações comercializados na cidade de São Paulo / Ocurrence study for arsenic, mercuric and selenium compounds in shark sample commercialized on São Paulo city

Michela Denobile 03 August 2007 (has links)
Os metais de relevância toxicológica provenientes de fontes naturais e antropogênicas continuamente entram no ecossistema aquático causando sérios problemas à saúde humana e ambientais devido a sua toxicidade, longa persistência, bioacumulação e biomagnificação na cadeia alimentar. A contaminação de peixe e produtos da pesca por metais é de interesse da saúde pública. No Brasil, o Ministério da Saúde estabelece o limite máximo de tolerância (LMT) de 1,0 mg/kg para o arsênio em peixe e produtos da pesca e 0,5 mg/kg para o mercúrio, e 1,0 mg/kg em peixe predadores. O LMT não foi estabelecido para arsênio inorgânico, metilmercúrio e selênio. Este trabalho tem por objetivo avaliar a presença de arsênio total, arsênio inorgânico, mercúrio total, metilmercúrio e selênio em amostras de peixe cação comercializadas na cidade de São Paulo e analisar os resultados em relação à avaliação do risco. O arsênio total e o selênio foram determinados através de mineralização por via seca das amostras e quantificação utilizando absorção atômica com gerador de hidretos (FI-HG-AAS). O arsênio inorgânico foi determinado através de digestão ácida das amostras e posterior mineralização por via seca e quantificação utilizando FI-HG-AAS. O mercúrio total foi determinado através de digestão assistida por microondas em meio ácido e posterior quantificação do mercúrio total por espectrometria de fluorescência atômica com geração de vapor frio em fluxo contínuo (CV-AFS). O metilmercúrio foi determinado através de extração ácida das amostras e quantificação utilizando HPLC-termo-oxidação-CV-AFS. Os valores de As total nas amostras de cação analisadas variaram de 8,4 a 134,1 mg/kg (peso seco) e 2,1 a 33,5 mg/kg (peso úmido) e os valores de As inorgânico variaram de 0,013 a 0, 738 mg/kg (peso seco) e 0,0033 a 0,1845 mg/kg (peso úmido). Os valores de Hg total variaram de 0,7 a 14,6 mg/kg (peso seco) e 0,18 a 3,65 mg/kg (peso úmido). Os valores de metilmercúrio variaram de 0,46 a 8,67 mg/kg (peso seco) e 0,12 a 2,17 m/kg (peso úmido). Os valores de selênio variaram de 0,5 a 2,6 mg/kg (peso seco) e 0,13 a 0,65 mg/kg (peso úmido). Os valores de razão molar entre Hg e Se variaram de 0,28 a 5,39 (Hg:Se), e a média foi igual a 1,69. O PTWI para o arsênio inorgânico é 15 µg/kg de peso corpóreo (WHO, 1989), e assumindo uma média de peso corpóreo de 65kg, a ingestão de arsênio inorgânico proveniente do consumo de cação representa apenas 0,0007% do valor de referência TDI (Ingestão diária tolerável) para média brasileira. O PTWI para o Hg total é 5 µg/kg de peso corpóreo (WHO, 2003) e, a ingestão de Hg total por pessoa por dia proveniente apenas do consumo de cação para a média brasileira representa 0,17% do valor de referência TDI. / Metals of toxicological relevance from natural and anthropogenic sources continuously enter the aquatic ecosystem and cause serious environmental problems to human health and environment due to their toxicity, persistance, bioaccumulation and biomagnification in the food chain. Seafood metal contamination of is a public health interest. In Brasil, the Minister of Health establishes the maximum residue level (MRL) 1.0 mg/kg for arsenic in seafood and 0.5 for mercury and 1.0 for mercury in predator fish. The MRL was not stablished for inorganic arsenic, methylmercury and selenium. The purpose of this study is to evaluate the presence of total arsenic, inorganic arsenic, total mercury, methylmercury and selenium in shark samples commercialized in São Paulo city, and to evaluate their risk. The total arsenic and selenium were determined through sample dry ash and quantification by flow Injection -hydride generation-atomic absorption spectrometer (FI-HG-AAS). The inorganic arsenic was determined through sample acid digestion, ulterior dry ash and quantification by FI-HG-AAS. The total mercury was determined through sample acid digestion in microwave and quantification by atomic f1uorescence spectrophotometer with a cold vapor generator (CV-AFS). Methylmercury was determined by sample acid extraction and quantification by HPLC-termo-oxidation-CV-AFS. The levels of total arsenic vary between 8.4 and 134.1 mg/kg (dry weight) and 2.1 and 33.5 mg/kg (fresh weight) and levels of total inorganic arsenic vary between 0.013 and 0.738 mg/kg (dry weight) and 0.0033 and 0.1845 mg/kg (fresh weight). The levels of total mercury vary between 0.7 and 14.6 mg/kg (dry weight) and 0.18 and 3.65 mg/kg (fresh weight). The levels of methylmercury vary between 0.46 and 8.67 mg/kg (dry weight) and 0.12 and 2.17 m/kg (fresh weight). The levels of selenium vary between 0.5 and 2.6 mg/kg (dry weight) and 0.13 and 0.65 mg/kg (fresh weight). The values of molar reason between Hg and Se vary 0.28 and 5.39 (Hg:Se), and the media was 1.69. The PTWI for inorganic arsenic is 15 µg/kg body weight (WHO, 1989), and assuming an average body weight of 65 Kg, the ingestion of inorganic arsenic from shark ingestion represents only 0,0007% of the reference value TDI (Tolerable daily ingestion) for Brazilian media. The PTWI for total mercury is 5 µg/kg body weight (WHO, 2003) and the ingestion of total mercury per person per day from shark ingestion for Brazilian media represents 0.17% of the reference value TDI.
585

Évaluation de l'état de contamination des bassins versants par les résidus de médicaments : utilisation des biofilms épilithiques comme marqueur d'imprégnation du milieu / Study of contamination level of watersheds by pharmaceuticals : epilithic biofilms as impregnation marker

Laurent, Elodie 10 December 2013 (has links)
L'état des milieux aquatiques est un point essentiel de l'évaluation demandée par la Directive Cadre Européenne (DCE 2000/60/CE) visant à préserver ou à restaurer les masses d'eau superficielles et souterraines d'ici à 2015. A cet égard, les médicaments font désormais partis des contaminants organiques largement recherchés dans les eaux continentales de surface mais leur écodynamique sur tout un bassin versant est encore méconnue. Ce travail a ainsi apporté une évaluation de l'état de contamination de bassins versants par les médicaments à l'aide des biofilms épilithiques comme marqueur de l'imprégnation du milieu.La cartographie de l'imprégnation du bassin versant de la Vienne a permis de mettre en évidence une plus forte concentration en médicaments dans la partie amont du bassin que dans la partie aval (associée à la transition entre le socle granitique et les bassins sédimentaires). Les teneurs en médicaments mesurées dans les biofilms ont montré un facteur de concentration de 1000 par rapport aux teneurs rencontrées dans l'eau – traduisant ainsi un phénomène de bioaccumulation dans ce compartiment.L'hétérogénéité de l'habitat benthique (diversité des roches, différence d'exposition) influence le niveau d'imprégnation des biofilms sous certaines conditions d'exposition à un rejet.La majeure partie des biofilms situés en aval de l'ensemble des stations d'épuration est plus fortement contaminée. En revanche les mesures d'imprégnation effectuées sur le bassin de l'Arve n'ont montré aucun effet significatif de l'apport d'une station d'épuration recevant les effluents du Centre hospitalier Alpes Léman. / The European Water Framework Directive (DCE 2000/60/CE) aims to restore and protect aquatic ecosystems with the preservation of chemical and ecological status by 2015. In this sense, pharmaceuticals are part of organic contaminants currently investigated in surface waters but their fate along a watershed is still poorly known. This study has made an assessment of the contamination level of watersheds by pharmaceuticals using epilithic biofilms as a marker of the impregnation of the habitat.The impregnation mapping of the Vienne River watershed has highlighted a higher pharmaceutical concentration in the upper part of the river than in the lower part (associated with the transition from the granitic bedrock to the sedimentary basin). Pharmaceutical concentrations measured in the biofilms were 1000-fold higher than concentrations found in water – reflecting a phenomenon of bioaccumulation in this compartment.The habitat heterogeneity (rock diversity, exposure level) influences the impregnation degree of biofilms, depending on the exposure to point source pollution.Most biofilms located downstream from a wastewater treatment plant discharge were heavily contaminated with pharmaceuticals. On the other hand, the biofilms collected from the Arve River watershed have shown no significant effect of a wastewater treatment plant discharge receiving effluents from the hospital "Centre hospitalier Alpes Léman" on the impregnation of biofilms.
586

Interference mitigation in 5G mobile networks : Uplink pilot contamination in TDD massive MIMO scheme / Atténuation des interférences dans les réseaux mobiles 5G : Contamination pilote des liaisons montantes dans le schéma massif MIMO TDD

Abboud, Ahmad 22 September 2017 (has links)
Par la révolution du Cloud Computing et des Smartphones, une quantité énorme de données devrait traverser le réseau chaque seconde où la plupart de ces données sont fournies par des mobiles utilisant des services Internet. La croissance rapide de la bande passante et des demandes de QoS rend les réseaux mobiles du 4ème G insuffisants. Le système de prochaine génération doit avoir un taux de sommation de 100Mbps à 1Gbps par terminal utilisateur (UT), avec une densité de connexion supérieure à 1M connexion / Km2, la mobilité des véhicules à grande vitesse jusqu'à 500 km / h et une fin à la fin (E2E) retardent moins de 10 ms. Un candidat prometteur qui peut répondre à ces demandes est le système sans fil à multiples sorties multiples (MIMO) Multi-Cell Multi-Cell. Cependant, la capacité Massive MIMO est délimitée par l'Inter-cell Interference (ICI) en raison de la réutilisation du pilote et, par conséquent, de la contamination du pilote. Dans cette thèse, nous étudions la contamination du pilote de liaison montante dans le système de formation à la division temporelle (TDD) des réseaux sans fil MIMO massifs. En supposant un canal de décoloration, l'intervalle de cohérence sera temporairement limité, où l'estimation du canal, la réception des symboles et le précodage des symboles doivent être effectués dans le même intervalle. Cela dit, la longueur du pilote de formation est limitée. De même, le nombre de terminaux de l'utilisateur (UT) par zone d'interférence est également limité. Inspiré par la variation de la taille de l'intervalle de cohérence parmi les UT, cette recherche présente deux nouvelles contributions indépendantes pour faire face à la contamination pilote de liaison montante dans le MIMO massif. La première contribution répertorie la région de couverture de la cellule de base (BS) dans une carte d'information d'état de chaîne (CSI). Cette carte est créée et mise à jour à l'aide d'un algorithme spécial d'apprentissage machine, et elle est exploitée pour prédire UT CSI au lieu d'estimer ses canaux. Compte tenu de cela, la formation des pilotes aériens et de liaison montante est considérablement réduite. La deuxième contribution classe les UT en fonction de la taille de leur intervalle de cohérence de canal. En outre, nous appliquons une technique de changement de pilote pour déplacer des pilotes similaires vers différentes positions temporelles (qui sont considérées comme vides en raison de trames TDD pilotes vides). Les résultats de la simulation montrent une augmentation à l'échelle de la performance du MIMO massif, en particulier dans la performance de l'efficacité énergétique et spectrale, UT par cellule et taux d'addition. En particulier, la troisième contribution évolue le MIMO massif multi-cellulaire à une performance de cellule unique et même surmonté un simple énorme conventionnel dans l'efficacité énergétique et UT par cellule. / By the revolution of Cloud Computing and Smartphones, an enormous amount of data should traverse the network every second where most of this data are delivered by mobiles using internet services. The fast growth in bandwidth and QoS demands makes the 4th G mobile networks insufficient. The next generation system must afford a sum rate from 100Mbps up to 1Gbps per User Terminal (UT), with a connection density that exceeds 1M connection/Km2, the mobility of high-speed vehicles up to 500 km/hr and an End to End (E2E) delay less than 10ms. A promising candidate that can offer those demands is the Multi-User Multi-Cell Massive Multiple-Input Multiple-Output (MIMO) wireless system. However, Massive MIMO capacity is upper bounded by the Inter-cell Interference (ICI) due to pilot reuse and thus, pilot contamination. In this thesis, we investigate the uplink pilot contamination in Time Division Duplexing (TDD) training scheme of massive MIMO wireless networks. Assuming block-fading channel, the coherence interval will lag for a limited duration, where channel estimation, symbol reception, and symbol precoding must be done within the same interval. Having said that, the training pilot length is limited. Likewise, the number of User Terminal’s (UT’s) per interference region is also limited. Inspired by the variation of coherence interval size among UT’s, this research introduces two independent novel contributions to deal with uplink pilot contamination in massive MIMO. The first contribution maps the Base Station (BS) cell coverage region into a Channel State Information (CSI) Map. This map is created and updated using a special machine-learning algorithm, and it is exploited to predict UT CSI instead of estimating their channels. In view of this, training overhead and uplink pilots are reduced significantly. The second contribution classifies UT’s based on the size of their channel coherence interval. Furthermore, we apply a pilot shifting technique to shift similar pilots to different time position (that considered empty due to empty pilot TDD frames). Simulation results show a scaled increase in the performance of massive MIMO especially in the performance of energy and spectral efficiency, UT per cell and sum-rate. In particular, the third contribution evolves multi-cell massive MIMO to a single cell performance and even overcome single conventional huge in the energy efficiency and UT per cell.
587

Infections nosocomiales, comportement soignants et technologies innovantes / Nosocomial infections, healthcare workers behaviors and new technologies

Boudjema, Sophia 09 December 2016 (has links)
Les infections nosocomiales sont responsables de milliers de décès chaque année. Les soignants, les patients et l'environnement à l'hôpital peuvent être source de contamination. Les objets tels que les téléphones cellulaires, les stéthoscopes, les tensiomètres, les cravates, les blouses et les bagues sont utilisés par les soignants et peuvent être contaminés. Ils deviennent alors des vecteurs potentiels pouvant être responsables d'infections nosocomiales. Les mains des soignants peuvent aussi être un vecteur de la transmission d'agents pathogènes. Respecter l'ensemble des règles d'hygiènes au quotidien est indispensable mais peut être contraignant pour les soignants. Afin d'avoir une mesure plus précise de la désinfection des mains, un outil automatique de mesure appelé MédiHandTrace® (MHT) a été développé, et breveté. Il permet de tracer les soignants grâce à leurs sabots pucés. MHT montre des taux d'observance inférieurs à 50% et aussi que l'hygiène des mains est individuelle. Aussi, Nous avons voulu comprendre le raisonnement des soignants au regard de leurs pratiques d'hygiène. Grâce à la vidéo, nous avons mis en lumière des comportements singuliers. L'amélioration de l'hygiène des mains reste une priorité. En conséquence, nous avons introduit des outils couplés à MHT, envoyé des sms sur les téléphones des soignants donnant leurs performances individuelles. L'hygiène des mains est un geste simple, mais sa réalisation se fait dans des situations de soins souvent complexes. L'adhérence à l'hygiène reste multifactorielle nécessitant l'apport de nouveaux outils d'apprentissage et de communication afin de délivrer des messages simples et efficaces auprès des soignants. / Nosocomial infections are responsible for thousands of deaths each year. Healthcare workers (HCW), patients and the hospital environment can be a source of contamination. Fomites such as cell phones, stethoscopes, tensiometers, ties, gowns and rings are used by HCW and may be contaminated. They become potential vectors that can be responsible for nosocomial infections. The HCWs hands' can also be a vector for the transmission of pathogens. Respecting all the rules of hand hygiene in everyday life is essential but can be binding for the HCW. In order to have a more accurate measurement of hand disinfection, an automatic measuring tool called MédiHandTrace® (MHT) was developed and patented. It makes it possible to trace the HCWs with tags into their shoe hoofs. MHT shows compliance rates below 50% and also that hand hygiene is individual. Also, we wanted to understand the reasoning of HCW with regard to their hygiene practices. Through the video, we have highlighted some singular behaviors of HCWs. Improving hand hygiene remains a priority. As a result, we introduced tools coupled with MHT, sent sms to the phones of HCWs showing their individual performance. Hand hygiene is a simple gesture, but its realization takes place in often complex care situations. Adherence to hand hygiene remains multifactorial, requiring new learning and communication tools to deliver simple and effective messages to HCWs.
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Etude des mécanismes histologiques et physiologiques du transfert de la chlordécone (insecticide organochlore) dans les vegetaux / Study of physiological and histochemical mechanisms of chlordecone transfer, an organochlorinated insecticide, in plant

Létondor, Clarisse 14 February 2014 (has links)
La chlordécone (CLD) est un insecticide organochloré qui a été utilisé principalement aux Antilles pour lutter contre le charançon du bananier (Cosmopolites sordidus). Sa faible dégradabilité dans le sol et sa dispersion dans les bassins versants entraînent une contamination durable des sols agricoles et des écosystèmes environnants. Cela pose un problème d’exposition pour l’Homme par la consommation de végétaux contaminés et pour l’environnement par le transfert de la molécule dans les chaînes alimentaires (bioamplification). Pour l’Homme, les principaux végétaux à risque sont les légumes-racines, en contact direct avec la CLD dans le sol, mais aussi les autres légumes car des résidus de CLD sont retrouvés dans les parties aériennes, tiges ou feuilles. Ce travail de thèse a porté sur le transfert sol-plante de la CLD, d’une part dans les tubercules des légumes-racines pour appréhender le risque sanitaire et d’autre part dans les graminées pour le risque environnemental. La lipophilie de la CLD joue un rôle majeur dans son transfert dans les plantes. La CLD a une affinité particulière pour les tissus lipophiles, notamment le périderme subérifié des tubercules et les parois cellulaires incrustées de lignine des vaisseaux du xylème. En outre, le transfert est dépendant de l’architecture de la plante, de sa physiologie et de l’histologie de ses organes. Nous avons mis en évidence deux voies de contamination des plantes par la CLD : l’absorption racinaire et l’adsorption sur le périderme des tubercules. Ces phénomènes sont suivis de la translocation de la molécule vers les tissus internes du tubercule par diffusion et vers la partie aérienne de la plante par évapotranspiration via les faisceaux vasculaires du xylème. Dans le cas des tubercules, nous avons distingué la part de contamination apportée par l’absorption racinaire de celle due à l’adsorption péridermique. Chez le radis, il a été montré que le phénomène prépondérant était la diffusion trans-péridermique. Une analyse du risque de contamination de tubercules couramment consommés aux Antilles (patate douce, dachine, igname) a été réalisée en se basant notamment sur l’architecture de la plante et l’histologie des tissus mis en place lors de la tubérisation. Concernant les graminées, la capacité de transfert de la CLD dans la partie aérienne de la plante a été étudiée chez plusieurs graminées usuelles. Le potentiel de contamination de la plante dépend de ses caractéristiques physiologiques (métabolisme) et de son cycle de vie (pérennité). Ces caractéristiques pourraient permettre d’orienter le choix de certaines graminées pour la phytoremédiation de la CLD. / Chlordecone (CLD) is an organochlorine insecticide mainly used in French West Indies to struggle against banana weevil (Cosmopolites sordidus). Its low degradability into soils and its spreading in catchment basins cause a sustainable contamination of agricultural soils and surrounding ecosystems. This leads to a human exposure risk, by food consumption of contaminated vegetables, and to an environmental risk by transfer of CLD in food chains. Main hazardous vegetables for human health are root-vegetables that are directly in contact of soil but also other vegetables because CLD residues are found in aerial parts of plant, leaves and shoots. The environmental risk seems to be the biomagnification of contamination in trophic chains due partly by consumption of contaminated plants. This work focused on the CLD soil-plant transfer, on the one hand in tubers of edible-roots for knowing the health risk and on the other hand in grasses for environmental risk. The CLD lipophilicity plays a major role in its transfer to plants. CLD exhibits a certain affinity for lipophilic tissues particularly for the suberised periderm of tubers and the xylem cell walls that are thickened by lignin. In addition, transfer depends on plant architecture, physiology and organ histology. Two ways of CLD plant contamination were highlighted: roots absorption and adsorption onto tuber periderm. These mechanisms are followed by CLD translocation towards internal tissues of tuber by diffusion and to above-ground parts of the plant within the transpiration stream occurring in vascular xylem vessels. For tubers, we distinguished between the contamination brought by roots absorption and the one brought by peridermic adsorption. In radish, the trans-peridermic diffusion was showed as the major way of contamination. A risk analysis mainly based on plant morphology and tissue histology set up during tuberization process was realized. For grasses, CLD transfer ability to aerial part of plant was studied in several usual gramineae (yam, sweet popato, dasheen). Plant contamination potential is mainly determined by its physiological traits (metabolism) and its life cycle (perenniality). These features could drive the choice of some gramineae to perform CLD phytoremediation.
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Complémentarité fonctionnelle en phytoremédiation dans un sol à contamination mixte

Lachapelle, Anne 05 1900 (has links)
No description available.
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Analyses des risques de pathologies cancéreuses et non cancéreuses au sein de cohortes de travailleurs de l'uranium / Risk Analysis of Cancerous and Non-Cancerous Diseases in Cohorts of Uranium Workers

Bouet, Ségolène 21 September 2018 (has links)
A ce jour, l’évaluation des risques associés à l’incorporation de radionucléides et l’élaboration des normes de radioprotection en résultant sont principalement basées sur les résultats du suivi épidémiologique de populations exposées aux rayonnements ionisants par voie externe. Les analogies et extrapolations employées dans cette démarche sont entourées d’incertitudes. Afin de pouvoir évaluer la validité des hypothèses retenues dans ce cadre par la Commission Internationale de Protection Radiologique, il est nécessaire de réaliser de nouvelles études épidémiologiques au sein de populations exposées à des émetteurs internes. C’est notamment le cas pour ce qui concerne les expositions à l’uranium, dont les effets sanitaires potentiels demeurent mal caractérisés. Par ailleurs, alors que les effets cancérigènes des radiations ionisantes sont établis et de mieux en mieux caractérisés, l’hypothèse d’un effet de faibles doses de rayonnements ionisants sur le développement de maladies de l’appareil circulatoire a été émise récemment, et demande à être évaluée de manière approfondie.L’objectif de cette thèse est de contribuer à améliorer la connaissance des effets sanitaires des expositions chroniques à de faibles doses de rayonnements ionisants, en particulier du fait de contamination internes par l’uranium, en support à l’évaluation et si nécessaire à la consolidation des normes internationales de radioprotection.La thèse s’articule autour de trois axes:- L’analyse de la mortalité dans une cohorte de 1300 travailleurs d’usines de traitement du minerai d’uranium (F-MILLERS), par comparaison avec la mortalité de la population générale française par calcul de rapports de mortalité standardisés.- L’analyse de l’association entre la dose (interne et externe) et la mortalité par cancers et maladies cardiovasculaires dans une cohorte de 4000 travailleurs de l’uranium: Analyse statistique classique (fréquentiste) incluant une exploration détaillée de l’impact de potentiels facteurs confondants individuels rarement disponibles dans d’autres cohortes de travailleurs du nucléaire (ex: obésité, tabagisme, tension artérielle).- Le développement d’une approche hiérarchique bayésienne permettant de tenir compte des incertitudes engendrées par l’estimation de la dose interne à partir de mesures radiotoxicologiques fortement censurées à gauche (i.e., inférieures à un seuil) dans l’estimation de risques sanitaires radio-induits, basée sur cette dose. / Nowadays, the assessment of the risks associated with the incorporation of radionuclides and the resulting development of radiological protection standards are mainly based on the results of the epidemiological monitoring of populations exposed to external ionizing radiation. The analogies and extrapolations used in this process are surrounded by uncertainties. In order to be able to evaluate the validity of the assumptions adopted in this context by the International Commission on Radiological Protection (ICRP), it is necessary to conduct new epidemiological studies in populations exposed to internal emitters. This is particularly the case for uranium exposures, whose potential health effects remain poorly characterized. Moreover, while the carcinogenic effects of ionizing radiation are established and increasingly well characterized, the hypothesis of an effect of low doses of ionizing radiation on the development of diseases of the circulatory system has been suggested recently, and requires to be evaluated thoroughly.The aim of this PhD thesis project is to improve the knowledge of the health effects of chronic internal exposure to low doses of ionizing radiation, particularly due to internal contamination by uranium, in support of the evaluation and if necessary to the consolidation of international radiation protection standards.The PhD thesis project includes three axes:- Analysis of mortality in a new cohort of 1,300 workers employed by uranium-milling companies, by comparison with the mortality of general French population by computing standardized mortality ratios.- Analysis of the association between dose (internal and external) and mortality from cancer and cardiovascular diseases in a cohort of 4,000 uranium workers: classical statistical analysis (frequentist) included detailed exploration of the impact of potential confounding factors rarely available in other cohorts of nuclear workers (e.g.: obesity, smoking, blood pressure)- Development of a Bayesian hierarchical approach allowing to account for uncertainties induced by the estimation of internal dose from radiotoxicological measurement that are strongly left-censored (i.e., lower than a threshold) in radiation-induced risk estimates, based on this dose.

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