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Caracterização mecânica e microestrutural de juntas tubulares soldadas em aço API 5L Grau B com base na norma Petrobrás N-2301 / Mechanical and microstructural characterization of tubular welded joints on API 5L grade B steel based on Brazilian National Standard Petrobras N-2301Sgobbi, Alexandre Amaral 22 April 2015 (has links)
Para a certificação de um procedimento de soldagem, quer seja de alta responsabilidade na soldagem de oleodutos e gasodutos em tubulações de aço carbono ou para um uso rotineiro e diário em fábricas e oficinas, deve ser realizada uma análise profunda dos fenômenos ocorridos no material de base (MB), no metal de adição (MA) e na zona afetada pelo calor (ZAC). Por meio desta análise criteriosa na qualificação de um procedimento de soldagem, o procedimento é liberado para ser utilizado, seja qual for o objetivo final da soldagem. Apenas com a Especificação do Procedimento de Soldagem (EPS) qualificada em mãos é possível iniciar os trabalhos de soldagem, e caso esta seja seguida integralmente, o sucesso do processo está a um passo de se concretizar. Para demonstração desta interação existente entre qualificação, análise dos resultados, aprovação dos ensaios e aprovação da especificação, foi desenvolvido este trabalho utilizando o material de base na forma tubular API 5L Gr. B soldado com os processos eletrodo revestido (SMAW) e arame tubular autoprotegido (FCAW-S). Foi utilizada uma junta tubular como exemplo de estudo e qualificação de um procedimento de soldagem baseado na documentação contida na norma da Petrobrás N-2301 e em outros códigos e normas, que regem a qualificação do processo de soldagem utilizado em refinarias e plantas de produção brasileiras. Foram estudados em conjunto os resultados obtidos por meio de ensaios mecânicos, ensaios não destrutivos e microestruturais. Ambas as Especificações dos Procedimentos de Soldagem preliminares (pEPS), estabelecidas antes do início da soldagem dos dois processos de soldagem, foram aprovadas e qualificadas, satisfazendo as características macro e microscópicas, metalúrgicas e mecânicas da junta soldada. / A comprehensive analysis of the phenomena occurring in the base metal (MB), filler metal (FM) and the heat affected zone (HAZ) should be conducted to provide the qualification of the welding procedure, either in high-demand carbon steel oil & gas pipelines or standard factory & workshop daily, usual operation. By means of this thorough welding procedure qualification, the process will be released, whatever the ultimate goal of welding. Only after the welding procedure specification (WPS) is qualified, is possible to start any welding work, and being the norm fully observed, the process is nearly to start successfully. The present work has been elaborated to demonstrate the interaction of qualification, result analysis, tests and specification approval, by applying the following elements: tubular base metal API 5L grade B welded with Shielded Metal Arc Welding process (SMAW) and self-shielded Flux Cored Arc Welding process (FCAW-S). A tubular joint was used as sample for a welding procedure qualification studies based on technical documentation specified on Petrobras N-2301, a Brazilian standard, and any others codes and standards that rule welding qualification on refineries & production plants of this company. The results obtained through mechanical testing, non-destructive testing and microstructure were studied together. Both preliminary welding procedure specifications (pWPS) established before the welding of these two welding processes, have been approved and qualified. The support given by welding qualification record (WQR) allows the joints to be welded in production, and result in reliable weld bead that satisfy the macro & microscopic, metallurgical and mechanical characteristics.
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Caractérisation et modélisation des potentiels induits par les commutations des gradients de champ magnétique sur les signaux électrophysiologiques en IRM / Caracterization and modeling of magnetic field switched gradient-induced voltages on electrophysiological signals in MRIEl Tatar, Aziz 29 March 2013 (has links)
Les développements récents des techniques IRM engendre des sources de potentiels induits qui « polluent » les signaux électrophysiologiques, utilisé simultanément en IRM pour surveiller le patient et synchroniser les images. Le système élaboré dans ce travail est compose de deux modules « émetteur-récepteur » IRM-compatibles. Le premier permet d’introduire dans le tunnel d’IRM des signaux EPS dont on connait les caractéristiques. Les signaux sont injectés dans un tissu conducteur placé dans le tunnel. Le second module permet de recueillir les signaux après leur contamination par les artéfacts générés par les séquences d’imagerie. Il comporte 20 canaux répartis en quatre bandes fréquentielles (40, 80, 160 et 350 Hz). Des mesures du potentiel induit ont été réalisées en environnements 1,5 T et 3 T. Nous pouvons ainsi analyser les modifications des paramètres des signaux selon les séquences, mais aussi à l’intérieur des différentes bandes de fréquences. Dans ce travail, nous présentons une caractérisation et modélisation des potentiels induits par les commutations de gradients de champ magnétique recueilli par notre dispositif expérimental. La caractérisation et la modélisation permettent d’obtenir des informations pertinentes à prendre en compte pour l’élaboration des algorithmes de filtrage efficaces et robustes. / New developments in MRI techniques create sources of induced voltages that “pollute” the simultaneously acquired electrophysiological signals (EPS), used to monitor patients and/or synchronize images. We developed a device to allow a deep study of the contamination mechanism, which would assist in elaborating new tools to obtain higher quality EPS. The system consists of three main modules: (i) a signal transmission system composed of an EPS generator and a transmission box, which transmits the EPS to a MR-compatible receiver inside the tunnel, (ii) an electro-conductive tissue-mimicking phantom in which the EPS is injected, (iii) a signal collection module composed of a MR compatible amplifier-transmitter that emits, via an optical cable, the collected signal to a receiver box placed outside the MRI room. The receiver box comprises 20 channels distributed into four frequency bands (40, 80, 160, and 350 Hz). Measurements of the induced voltages were performed in 1.5 T and 3 T MRI environments. An algorithm to extract and analyze and model the induced voltages was developed. The modeling algorithm is based on a sinusoidal decomposition of the induced voltages. This work aimed to assess the disturbance level of the EPS, when using larger bandwidth amplifiers. The characterization and modeling of the induced voltages, which represent the dominant noise, reveal relevant information which can be used to develop robust and efficient noise reduction algorithms.
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遺傳演算法在財務預測之應用 / The Application of Genetic Algorithms on the Finance Forecasting范饒耀, Farn, Rou-yao Unknown Date (has links)
每股盈餘是公司的重要財務資訊之一,它可以反應公司的經營績效,因此一方面可以提供給投資者作為投資決策之參考,另一方面提供給管理者作為管理評量的參考指標之一。過去在每股盈餘等財務預測往往以統計方法進行,因此在自變數選擇上常受到限制,同時有些預測模式其輸出結果往往只能以常長或衰退等二元式的結果表示。而另一方面,以類神經網路預測方式的預測模式可能因變數增加,使得網路變的較複雜。本研究嘗試以人工智慧中的遺傳演算法來作為預測的工具,發展財務預測模型,來預測每股盈餘,解決過去預測方式的限制或缺點。同時也將對過去的遺傳演算法稍做修正,並嘗試以實際值的編碼方式進行編碼,以符合需求。最後進一步比較遺傳演算法和其他預測方式,瞭解以遺傳演算法做於預測每股盈餘工具的特性及優缺點。 / Earnings per share (EPS) is one of the important financial
indicators to a corporation. It reflects the operating
performance of a corporation. On one hand, EPS provides
information available to investors for decision making; on the other hand, it is an indexfor measurement of management. In the past, financial forecasting was often done by using statistical models. However, the input variables were limited by using these statistical models. Besides, some stastical models only provide dichotomy output ,such as either "grwoth" or"decline". The neural network forecasting model will be more of complexity, when the input variable increases. This research attempts to develop a financial forecasting model to forecast the EPS by using the Genetic Algorithms, which is a new topic of artificial intelligence. This model excludes both the limitations and disadvantages of the models mentioned above. Here, the genetic algorithms will be modified and the real number will be used to code as a gene of achromosome to meet the requirements of the finacial model. Finally,we compare the genetic algorithms
financial forecasting model with the other ones in order to
understand the features, advantages and disadvantages of genetic algorithms as being a financial forecasting tool .
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The Effects Of Seed Sludge Type And Anoxic/aerobic Period Sequence On Aerobic Granulation And Cod, N Treatment PerformanceErsan, Yusuf Cagatay 01 January 2013 (has links) (PDF)
The aim of this master thesis study was improvement of the required operational conditions for aerobic granulation in sequencing batch reactors (SBRs).
In the first part of the study, membrane bioreactor sludge (MBS) and conventional activated sludge (CAS), were used to investigate the effect of suspended seed sludge type on granulation in SBRs. The MBS granules were found to be advantageous in terms of size, resistance to toxic effects, stability and recovery compared to CAS granules. During non-inhibitory conditions, sCOD removal efficiencies were 70± / 13% and 67± / 11% for MBS and CAS, and total nitrogen (TN) removal efficiencies were 38± / 8% and 26± / 8%, respectively.
In the second part of the study, the effects of period sequence (anoxic-aerobic and aerobic-anoxic) on aerobic granulation from MBS, and sCOD, N removal efficiencies were investigated. Granules developed in anoxic-aerobic period sequence were more stable and larger (1.8-3.5 mm) than granules developed in aerobic-anoxic sequence. Under steady conditions, almost 95% sCOD, 90% Total Ammonia Nitrogen (TAN) and around 39-47 % of TN removal was achieved. Almost 100% denitrification in anoxic period was achieved in anoxic-aerobic period sequence and it was observed around 40% in aerobic-anoxic period sequence.
The effects of influent sulfate (from 35.1 mg/L to 70.2 mg/L) on treatment efficiencies of aerobic granules were also investigated. The influent SO42- concentrations of 52.6 mg/L to 70.2 mg/L promoted sulfate reduction. The produced sulfide (0.24 mg/L to 0.62 mg/L) inhibited the ammonia-oxidizing bacteria (AOB) performance by 10 to 50%.
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Statistical Post-Processing Methods And Their Implementation On The Ensemble Prediction Systems For Forecasting Temperature In The Use Of The French Electric ConsumptionGogonel, Adriana Geanina 27 November 2012 (has links) (PDF)
The thesis has for objective to study new statistical methods to correct temperature predictionsthat may be implemented on the ensemble prediction system (EPS) of Meteo France so toimprove its use for the electric system management, at EDF France. The EPS of Meteo Francewe are working on contains 51 members (forecasts by time-step) and gives the temperaturepredictions for 14 days. The thesis contains three parts: in the first one we present the EPSand we implement two statistical methods improving the accuracy or the spread of the EPS andwe introduce criteria for comparing results. In the second part we introduce the extreme valuetheory and the mixture models we use to combine the model we build in the first part withmodels for fitting the distributions tails. In the third part we introduce the quantile regressionas another way of studying the tails of the distribution.
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Reforço de solo laterítico com fibras de sisal de distribuição aleatória, tratadas superficialmente com EPS reciclado / Reinforcement of lateritic soil with randomly sisal fibers distributed treated with recycled EPSLeocádio, Gislene Aparecida Santiago January 2005 (has links)
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Previous issue date: 2005 / Os elevados custos das obras de engenharia civil induzem a necessidade de se desenvolver estudos de processos de estabilização e reforço que possibilitem melhorar determinadas propriedades geotécnicas dos solos, de modo a enquadrá-los dentro das especificações construtivas vigentes. A técnica de reforço de solos através da inclusão de fibras tem sido estudada por vários pesquisadores, e tem se mostrado eficiente, melhorando várias propriedades de engenharia do solo, gerando um compósito bastante atraente para a engenharia geotécnica, que neste trabalho será denominado fibrossolo. A avaliação do efeito da adição de fibras de sisal ao solo laterítico foi feita experimentalmente, em laboratório, determinando-se o comportamento mecânico via ensaios de compactação (na energia do Proctor Normal) e CBR, bem como sua resistência ao cisalhamento, através do ensaio de cisalhamento direto. Adotou-se como ponto de partida para análise, os teores de fibra de 0,25% a 1,0% em função da massa seca do solo e, também, do comprimento das fibras, nos valores 10 a 25mm. O trabalho teve como objetivo complementar o estudo do efeito do tratamento superficial das fibras de sisal com poliestireno expandido (EPS) reciclado, visando sua aplicabilidade como elemento inibidor do processo de absorção de água. Com base nos resultados obtidos neste trabalho, notou-se que a adição de fibras de sisal tratadas de distribuição aleatória apresentou significativas melhorias nas propriedades mecânicas do solo laterítico, transformando-o em um produto de melhor qualificação para aplicação em obras de engenharia civil, e que o polímero utilizado mostrou-se bastante aplicado à análise proposta, promovendo diminuição da higroscopicidade das fibras de sisal. ____________________________________________________________________________________________________ / ABSTRACT: The high costs of the civil engineering construction requires the necessity to develop studies about the process of the stabilization and reinforcement which improves some geotechnical soils properties being part of the constructive specifications. The reinforcement technique of the soils with the inclusion of natural fibers has been studied for many researchers. It has showing efficient by improving many properties of the soil engineering which results in an interesting composite material for the geotechnical engineering. This composite is named fibersoil at this research. Experiments was done at the laboratory to evaluate the effect of the addition sisal fibers in the lateritic soil which will establish the mechanical behavior of the material through compaction tests, at the energy of the Normal Proctor and CBR. The shear strength was done through the direct shear test. Therefore, in the present investigation sisal fiber was randomly included in to the soil at four different percentages of fiber content with 0,25% to 1% by weight of raw soil and also considered different lengths between 10 to 25mm. The objective of this research is to contribute to the study on the effect of the sisal fibers with superficial treatment with recycled expanded polystyrene (EPS) inhibiting the absorption of water. With base in the results obtained in this work, it was noticed that the addition treated sisal fibers randomly distributed presented significant improvements in the mechanical properties of lateritic soil, transforming it in a product of better qualification for application in works of civil engineering, and that the polymer used it was shown quite applied to the proposed analysis, promoting decrease of the water absorption of the sisal fibers.
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Estudo de um novo eletr?lito polim?rico s?lido em forma de filme autossustent?vel: Poli(?xido de etileno)-tungstato de s?dioLima, Gilberto de 05 February 2016 (has links)
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Previous issue date: 2016-02-05 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / Filmes polim?ricos autossustent?veis baseados em um novo eletr?lito polim?rico s?lido (EPS), tendo como matriz hospedeira o poli(?xido de etileno) (POE) e como agente dopante o tungstato de s?dio (Na2WO4), foram obtidos para diferentes composi??es do sal (m = 0,20; 0,26; 0,30; 0,40; 0,50 e 1,31 mg). Os filmes foram caracterizados por DRX, FTIR, MEV/EDS, TG/DTG, DSC e EI. Os difratogramas de raios X confirmaram a natureza semicristalina do pol?mero e sugeriram que a adi??o do sal provoca uma redu??o na cristalinidade dos filmes. Os dados de FTIR permitiram a an?lise da intera??o entre os ?ons do sal e as cadeias polim?ricas. As micrografias obtidas por MEV demonstraram morfologia esferul?tica intercaladas por liga??es interlamelares para todas as composi??es estudadas. O estudo de TG/DTG mostrou que a decomposi??o t?rmica do eletr?lito ocorre em uma ?nica etapa com a adi??o do sal aumentando a estabilidade t?rmica dos filmes. Os dados de TG/DTG permitiram, ainda, o estudo cin?tico da decomposi??o t?rmica do eletr?lito por meio dos m?todos de Briodo (BR), Coats-Redfern (CR) e Horowitz-Metzger (HM) sugerindo uma cin?tica de 1? ordem para a rea??o de decomposi??o t?rmica dos filmes, assim como, a determina??o dos par?metros termodin?micos de ativa??o: E*, ?H*, ?S* e ?G*. O grau de cristalinidade foi determinado atrav?s dos dados de DSC e mostrou uma redu??o ap?s a adi??o do sal ao pol?mero. O eletr?lito POE/Na2WO4 exibiu um m?ximo de condutividade i?nica de 3,24x10-4 S.cm-1, a temperatura ambiente, para o filme com 1,31 mg do sal. Atrav?s dos dados de imped?ncia foi poss?vel o estudo de relaxa??o das cadeias do POE, assim como, a difus?o do sal entre estas cadeias. Os diagramas de imped?ncia, nos formatos Bode e Nyquist, permitiram o ajuste dos dados experimentais ? circuitos el?tricos equivalentes o que facilitou a associa??o dos componentes dos circuitos aos fen?menos f?sicos e qu?micos observados para os filmes e revelaram que, ap?s a adi??o do sal ao pol?mero, os filmes t?m suas propriedades el?tricas melhoradas. / Self-sustainable polymeric films based on new solid polymer electrolyte, having the
poly(ethylene oxide) (PEO) as host matrix and sodium tungstate as doping agent (Na2WO4),
were obtained from different salt compositions (m = 0.20; 0.26; 0.30; 0.40; 0.50 and 1.31
mg). The films were characterized through XRD, FTIR, SEM/EDS, TG/DTG, DSC and IS.
X-ray diffraction showed the semi crystalline nature of the polymer and confirmed that the
addition of salt induces reduction in the crystalinity of the films. FTIR data allowed the
identification of the interaction between salt ions and polymer chains and confirmed that these
interactions are of a physical nature. The micrographs obtained through SEM showed
spherulitic morphology interleaved by interlayered bonds for all of the compositions studied.
The TG/DTG study revealed that the thermal decomposition of the electrolyte almost happens
at a single stage with the addition of salt, increasing the thermal stability of the films.
TG/DTG data also allowed the kinetic study of the thermal decomposition of the electrolyte
through Broido (BR), Coats-Redfern (CR) and Horowitz-Metzger (HM) methods, suggesting
a first-order kinetic for the reaction of the thermal decomposition of the films, as well as the
setting of pre-exponential factor, A, and the thermodynamic activation parameters: E*, ?H*,
?S* and ?G*. The crystallinity degree was determined through DSC data and showed a
reduction after the addition of salt to the polymer. The polymer has its conductivity increased
after addition of the salt with the PEO-Na2WO4 electrolyte exhibiting maximum of ionic
conductivity of 3.24x10-4 S cm-1, to room temperature, for the film with 1.31 mg of salt (F6
film). The impedance data allowed the study on relaxation on PEO chains, even as the
diffusion of salt between these chains. The impedance diagrams, on Bode and Nyquist
formats, enabled the adjustment of the experimental data to equivalent electric circuits, which
facilitated the association of the circuit components to the physical and chemical phenomena
observed for the films and revealed that, after the addition of salt to the polymer, the films
have their electrical properties enhanced.
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Caracterização mecânica e microestrutural de juntas tubulares soldadas em aço API 5L Grau B com base na norma Petrobrás N-2301 / Mechanical and microstructural characterization of tubular welded joints on API 5L grade B steel based on Brazilian National Standard Petrobras N-2301Alexandre Amaral Sgobbi 22 April 2015 (has links)
Para a certificação de um procedimento de soldagem, quer seja de alta responsabilidade na soldagem de oleodutos e gasodutos em tubulações de aço carbono ou para um uso rotineiro e diário em fábricas e oficinas, deve ser realizada uma análise profunda dos fenômenos ocorridos no material de base (MB), no metal de adição (MA) e na zona afetada pelo calor (ZAC). Por meio desta análise criteriosa na qualificação de um procedimento de soldagem, o procedimento é liberado para ser utilizado, seja qual for o objetivo final da soldagem. Apenas com a Especificação do Procedimento de Soldagem (EPS) qualificada em mãos é possível iniciar os trabalhos de soldagem, e caso esta seja seguida integralmente, o sucesso do processo está a um passo de se concretizar. Para demonstração desta interação existente entre qualificação, análise dos resultados, aprovação dos ensaios e aprovação da especificação, foi desenvolvido este trabalho utilizando o material de base na forma tubular API 5L Gr. B soldado com os processos eletrodo revestido (SMAW) e arame tubular autoprotegido (FCAW-S). Foi utilizada uma junta tubular como exemplo de estudo e qualificação de um procedimento de soldagem baseado na documentação contida na norma da Petrobrás N-2301 e em outros códigos e normas, que regem a qualificação do processo de soldagem utilizado em refinarias e plantas de produção brasileiras. Foram estudados em conjunto os resultados obtidos por meio de ensaios mecânicos, ensaios não destrutivos e microestruturais. Ambas as Especificações dos Procedimentos de Soldagem preliminares (pEPS), estabelecidas antes do início da soldagem dos dois processos de soldagem, foram aprovadas e qualificadas, satisfazendo as características macro e microscópicas, metalúrgicas e mecânicas da junta soldada. / A comprehensive analysis of the phenomena occurring in the base metal (MB), filler metal (FM) and the heat affected zone (HAZ) should be conducted to provide the qualification of the welding procedure, either in high-demand carbon steel oil & gas pipelines or standard factory & workshop daily, usual operation. By means of this thorough welding procedure qualification, the process will be released, whatever the ultimate goal of welding. Only after the welding procedure specification (WPS) is qualified, is possible to start any welding work, and being the norm fully observed, the process is nearly to start successfully. The present work has been elaborated to demonstrate the interaction of qualification, result analysis, tests and specification approval, by applying the following elements: tubular base metal API 5L grade B welded with Shielded Metal Arc Welding process (SMAW) and self-shielded Flux Cored Arc Welding process (FCAW-S). A tubular joint was used as sample for a welding procedure qualification studies based on technical documentation specified on Petrobras N-2301, a Brazilian standard, and any others codes and standards that rule welding qualification on refineries & production plants of this company. The results obtained through mechanical testing, non-destructive testing and microstructure were studied together. Both preliminary welding procedure specifications (pWPS) established before the welding of these two welding processes, have been approved and qualified. The support given by welding qualification record (WQR) allows the joints to be welded in production, and result in reliable weld bead that satisfy the macro & microscopic, metallurgical and mechanical characteristics.
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Caractérisation de l'hydrophobie des polymères extracellulaires (PEC) extrait de biofilms : une étude basée sur la technique de la résine DAX-8 / Hydrophobic features of extracellular polymeric substances (EPS) extracted from biofilms : an investigation based on DAX-8 resin techniqueCao, Feishu 28 June 2017 (has links)
Les propriétés hydrophobes des polymères extracellulaires (PEC) exercent l’influence profonde sur les propriétés de la surface cellulaire. Cependant, de nombreux facteurs tels que les méthodes d'extractions, le type de substrat influencent les caractéristiques des PEC et les informations concernant des caractéristiques hydrophobes sont rarement documentées. L'objectif principal de cette étude est de développer une méthode appropriée pour étudier l'hydrophobicité des PEC, puis d'étudier les caractéristiques hydrophobes des PEC.Le fractionnement hydrphobe par la résine Supelite™ DAX-8 a d'abord été appliqué sur les PEC extraits de boues granulaires anaérobies, deux conditions de pH d'élution (pH 2 et 5) ont été testées. L'impact de sept méthodes d'extraction sur les caractéristiques hydrophobes des PEC a été évalué. Les résultats ont montré que les méthodes d'extraction et le pH de la solution extraitante ont influencé la composition des PEC et leur hydrophobicité. En outre, les extraitants des PEC, par exempe le formaldéhyde, l'éthanol, le dodécylsulfate de sodium (SDS) et Tween 20, ont non seulement introduit une teneur supplémentaire en carbone pendant la mesure du carbone organique total (COT), mais ils ont également interagit avec la résine DAX-8. En comparant la répartition du poids moléculaire apparent (aMW) des échantillons des PEC non traités et ajustés au pH détectés par chromatographie d'exclusion stérique (en anglais SEC), l’information plus complète d’aMW a été préservée à pH 5. Ainsi, le fractionnement hydrophobe par la résine DAX-8 à pH 5 et les méthodes physiques d'extraction PEC ont été préférés dans cette étude.Une analyse qualitative détaillée des caractéristiques hydrophobes des EPS a été étudiée par la technique de la matrice de fluorescence d’excitation-emission (EEM). Les résultats ont montré que les substances de type humique (HS-like) représentaient la majorité des composés organiques des PEC extraits de la boue granulaire anaérobie, et constituaient également le principal support moléculaire de l'hydrophobicité des extraits. Ces composés hydrophobes de type HS étaient essenciellement des molécules petites tailles de 8 kDa à <1 kDa. L’hydrophobité contributée par les protéines (PN) et les polysaccharides (PS) présentait un moindre rapport.Afin d’explorer les propriétés hydrophobes de PN et de PS, ainsi évaluer l'impact de l'addition de Ni(II) sur l'hydrophobicité des extraits des champignons, fongi Phanerochaete chrysosporium a été choisi. Les résultats ont montré que la teneur de PN et de PS dans les PEC extrait de ce type de fongi variait en fonction de la concentration de Ni(II). Avec une augmentation de la concentration de Ni de 0 mg/L à 25 mg/L, la teneur en PN a diminué alors que celle de PS a été augmentée. L'hydrophobicité des PEC du fongi, déterminée par le traitement de la résine DAX-8, a diminué lors que la concentration de Ni augmentait. Par ailleurs, l'intensité du pic de SEC correspondant aux molécules PN-like (Ex/Em = 225/345 nm) de 1,9 × 103 à 10 kDa a été augmentée par l'addition Ni; en même temps, la distribution d’aMW des composés organiques totaux (UV/210) dans les PEC restait presque stable. Ces résultats ont indiqué que les composés de type PN-like peuvent avoir déterminé l'hydrophobicité des PEC fongique dans des conditions de stress.Dans l’extrait plus hétérogène des PEC de boues granulaires anaérobies, des composés HS-like représentaient le composant organique majeur, ainsi le principal support moléculaire de l'hydrophobicité des PEC. En étudiant les caractéristiques hydrophobes des PEC extrait du champignon Phanerochaete chrysosporium, le PN et le PS des PEC jouaient un rôle actif dans la protection du champignon sous le Ni. La concentration élevée de Ni a diminué l'hydrophobicité des PEC fongique, mais elle a augmenté l'hydrophobicité de la surface cellulaire du champignon. Il semble que la présence de Ni favorise l'apparition d'un champignon plus hydrophobe / The hydrophobic properties of extracellular polymeric substances (EPS) exert a profound influence on the cell surface properties. However, many factors such as EPS extractions methods, substrate type influence EPS characteristics, and limited information regarding to the hydrophobic features of EPS can be found. The main aim of this study is to develop a proper method to study EPS hydrophobicity, and then investigate the hydrophobic features of EPS.The hydrophobic fractionation by Supelite™ DAX-8 resin was first applied on the EPS extracted from anaerobic granular sludge, two elution pH conditions i.e. pH 2 and 5 were tested. The impact of seven EPS extraction methods on the hydrophobic features of EPS was assessed. The results showed that the extraction methods and bulk solution pH dramatically influenced the EPS composition and their hydrophobicity. Besides, the EPS extracting reagents namely formaldehyde, ethanol, sodium dodecyl sulfate (SDS) and Tween 20 not only introduced extra carbon content during total organic carbon (TOC) measurement, but also interacted with the DAX-8 resin. By comparing the apparent molecular weight (aMW) distribution of the untreated and pH-adjusted EPS samples detected by size exclusion chromatography, more complete EPS aMW information was preserved at pH 5. Thus, the hydrophobic fractionation by DAX-8 resin at pH 5 and physical EPS extraction methods were preferred in this study.After identifying the proper conditions for DAX-8 resin fractionation, detailed qualitative analysis of the EPS hydrophobic features was further investigated. The results showed that the humic-like substances (HS-like) were the major organic constituent of the EPS extracted from the anaerobic granular sludge, and they were also the main molecular support of the EPS hydrophobicity. Those hydrophobic HS-like compounds were mainly small molecules ranging from 8 kDa to <1 kDa. Proteins (PN) and polysaccharides (PS) contributed to the EPS hydrophobicity to a lesser extent.The role of PN and PS in the EPS hydrophobicity was difficult to be shown. It is known that the major organic constituents of the EPS extracted from bacteria, algae and fungi are PN and PS. Therefore, to explore the hydrophobic features of PN and PS, as well as to investigate the impact of Ni(II) addition, on the EPS hydrophobicity, the fungus Phanerochaete chrysosporium was chosen. The results showed that the contents of PN and PS in the extracted fungal EPS varied with the Ni(II) concentration. With an increase in the Ni concentration from 0 mg/L to 25 mg/L, the PN content was decreased whereas the PS content was increased. The fungal EPS hydrophobicity, determined by the DAX-8 resin treatment, was decreased as the Ni concentration increased.Besides, the peak intensity on the size exclusion chromatography (SEC) corresponding to the PN-like molecules (Ex/Em = 225/345 nm) ranging from 1.9×103 to 10 kDa were intensified by the Ni addition, while the aMW distribution of the total organics (UV/210) in the EPS remained almost stable. These results indicated that those PN-like compounds may determine the hydrophobicity of fungal EPS under stress conditions.For the more heterogeneous EPS extracted from anaerobic granular sludge, HS-like compounds were identified as the major organic component, as well as the main molecular support of the EPS hydrophobicity. By studying the hydrophobic features of the EPS extracted from the fungus Phanerochaete chrysosporium, it showed that the PN and PS in the EPS played an active role in protecting the fungus under Ni stress. The increased Ni concentration decreased the hydrophobicity of fungal EPS, but it increased the cell surface hydrophobicity of the fungus. It seems that the presence of Ni promoted the fungus becoming more hydrophobic
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Le corps capacitaire en step : la construction de savoir-faire perceptifs au cours de l’expérience corporelle / The body capacity and step activity : the building of perceptive know-hows in body experiencePaintendre, Aline 28 November 2017 (has links)
Ces travaux de recherche fournissent un regard inédit en EPS sur le processus de développement corporel des lycéens engagés dans une séquence d’apprentissage en step, dans la cadre de la CP5. A partir d’une approche holistique du corps, tout à la fois vivant, vécu et décrit, la porosité entre ces trois dimensions est décryptée pour six lycéens. Les pistes d’exploration de cette thèse s’articulent autour d’un ancrage épistémologique en émersiologie, où la croisée des regards scientifiques offre une opportunité d’appréhender l’expérience corporelle de l’élève, afin de dresser des pistes scolaires et professionnelles nouvelles. Plusieurs voies d’accès, avec l’autoconfrontation sur fond de traces audiovisuelles en première et troisième personne, et la mesure de l’activité cardiaque par le cardiofréquencemètre, contribuent à la définition du corps capacitaire du lycéen. La nature des connaissances construites et actualisées au fil des leçons est en faveur d’une acuité de la perception sensorielle, complémentairement à une intensité d’exercice au service d’une amélioration des capacités aérobies. Les différents résultats traduisent la manière dont le répertoire esthésiologique du lycéen étend sa cartographie intéroceptive, par activation et éveil sensoriel, tout en montrant par voie de conséquence la constitution de savoir-faire perceptifs. En questionnant deux démarches d’enseignement différenciées par la place de la perception de son effort, une hétérogénéité esthésiologique et sensible chez les lycéens est révélée. Tout en offrant la possibilité d’estimer singulièrement les capacités du vivant par la performance aérobie des lycéens en step, ces travaux de recherche incitent les enseignants à la co-construction d’une posture d’écoute attentive à son corps, pour une confiance accrue en son expérience, favorable au développement de sa personne. / This study, rooted in physical and sport education, contemplates the body development process of high school students who have started a learning sequence of step practising, within the framework of the CP5 – own competence n° 5. Starting from a holistic approach of the body, which is simultaneously living, experienced and described, the porosity between those three dimensions is deciphered for six high school students. The exploration paths of this thesis are articulated around an epistemological rooting in emersiology, where crossed scientific observations offer an opportunity at tackling the student’s body experience, so as to set up new educational and professional paths for the student to be aware of his/her own body. Several access paths, with self-confronting over a background of audiovisual traces in the first and third persons, and measuring the heart beatings via a cardio frequency-meter, contribute to defining the high school student’s capacity body. The nature of the knowledge built up and updated in the course of the classes speaks in favor of the sensitive perception’s acuity, as a complement to an intense practicing whose aim is to improve the aerobics capabilities. The different results illustrate the way in which the high school student’s esthesiological repertory increases his/her interoceptive cartography, by activation and sensitive awakening, while displaying as a consequence the building up of perceptive know-hows. By questioning two differentiating teaching paths through how his/her effort is felt, the high school students’ esthesiological and sensitive heterogeneity is revealed. While making it possible to singularly assess the living body’s capabilities through the high school student’s aerobics performance in step, these research works incite teachers to co-build an attentive listening attitude towards their bodies by the students, so that their trust in what they experiment is better and favorable to the development of their persons.
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