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Le travail présenté dans ce mémoire concerne le cadre global de la connaissance de notre atmosphère. L'exploitation des spectres atmosphériques requiert une bonne connaissance des paramètres de raies des molécules qui la composent. En particulier de la vapeur qui en est l'absorbant principal. Des spectres ont été enregistrés avec le spectromètre par transformation de Fourier construit au laboratoire et ceux ci ont été traités en ajustement multi-spectres avec le logiciel MultiFiT. Ce travail se focalise sur la mesure précise des intensités de raie dans deux régions spectrales. A 10 µm, région d'intérêt atmosphérique pour l'instrument IASI, deux études sur les intensités sont présentées. Pour l'isotopologue principal de 1200 à 1400 cm-1, 300 transitions ont pu être mesurées et comparées aux données de la littérature. Le but de ce travail était de déterminer la meilleure base de données pour l'exploitation des spectres IASI. De 1000 à 2300 cm-1, les isotopologues H218O et HD18O ont été étudié à partir de spectres enrichis en 18O. Ce travail a permis de mesurer et d'attribuer un ensemble de 2500 transitions. Enfin ce mémoire propose une révision complète des intensités de la région 1.25µm, qui présentent un important problème dans les bases de données. 39 spectres ont été enregistrés pour cette région avec des échantillons d'eau naturelle. Plus de 11000 transitions ont pu être mesurées et sont comparées aux données de la littérature. Une partie de ces intensités, publiées en 2010, a été exploité par L. Tallis de l'université de Reading. Enfin ce mémoire présente le début d'une exploitation des coefficients d'élargissement obtenus dans la région de 1.25µm. / The work presented in this manuscript concern the knowledge of our atmosphere. In fact, the analysis of atmospheric spectra needs a good understanding of atmospheric molecular species. In particular the water vapor plays a special role as the first absorbent of earth's atmosphere. Spectra were recorded by Fourier transform spectrometer designed in the laboratory and lines parameters fitted with multi-spectra procedure named MultiFiT. The spectroscopic studies focus on lines intensity measurements for two different spectral ranges. The first presented is 10 µm, were two studies have been done. For the H216O isotopologue in the 1200 – 1400 cm-1 range, 300 transitions were measured and compared with literature data. The aim of this work was to determine the best spectroscopic database for IASI recording analysis. In 1000 to 2300 cm-1, H218O and HD18O isotopologue were measured with enriched 18O spectra. Over 2500 transitions were measured and assigned. Also this manuscript presents a huge work done in the 1.25µm region. This range appears in database with an important discrepancy for line intensities. 39 spectra were recorded with water vapor sample in natural abundance. Over 11000 transitions were measured and assigned, comparison to literature data are also presented. A part of this work were published in 2010 and used by L.Tallis, form University of Reading, for atmospheric application. At the end of this manuscript is presented the first comparisons with calculated data done for self broadening coefficients in the 1.25µm region.

Made available in DSpace on 2017-07-21T18:53:08Z (GMT). No. of bitstreams: 1 Tais Cardoso.pdf: 3212818 bytes, checksum: 69a285afd6131ea626c9cafa08881236 (MD5) Previous issue date: 2017-02-21 / Biodegradable films are alternative packaging, from renewable sources, with reduced environmental impact and can act in food preservation. The aim of this study was to produce edible films with mixes of gelatin (bovine origin), cassava bagasse and Spirulina platensis, using as a basis a cassava starch solution and glycerol. By means of a Simplex-Centroid design for mixtures of three components and three central points were obtained 10 formulations for the experiment. The properties evaluated were: moisture, thickness, density, grammage, opacity, color, permeability to water vapor, water solubility, swelling, tensile properties. The responses were modeled on mathematical model to obtain the response surfaces. The results showed no significant difference between the formulations for water activity parameters, density, weight, thickness, tensile strength, solubility and permeability. The results showed no significant difference between the formulations for parameters, water activity, density, weight, thickness, tensile strength, solubility and permeability. For the color parameter the formulation containing cassava starch and S. platensis, presented a* value higher due to the presence in greater concentration of the component S. platensis. The swelling was increased during the 60 min. None of the film formulations showed inhibition of microbial growth by disc diffusion technique. The content of S. platensis in the filmogenic compositions was not sufficient for microbial inhibition. The formulation for the ternary mixture in equal proportions was applied in Cambuci pepper (Capsicum sp.) and by monitoring the storage at room temperature and refrigeration it was observed an extension of shelf life of this raw material in 5 and 6 days, respectively. Thus, the use of the developed coating proved to be feasible. / Os filmes biodegradáveis são embalagens alternativas, de fontes renováveis, com reduzido impacto ambiental e podem atuar na conservação de alimentos. O objetivo deste trabalho foi produzir filmes com misturas de gelatina (origem bovina), bagaço de mandioca e Spirulina platensis, utilizando como base uma solução de amido de mandioca e glicerol. Por meio de delineamento Simplex-Centroide para misturas de três componentes e três pontos centrais, foram obtidas 10 formulações para a realização do estudo. As propriedades avaliadas foram: umidade, espessura, densidade, gramatura, opacidade, cor, permeabilidade ao vapor d'água, solubilidade em água, intumescimento e propriedades de tração. As respostas obtidas foram modeladas para obtenção das superfícies de contorno. Os resultados mostraram que não houve diferença significativa entre as formulações para os parâmetros Aw, densidade, gramatura, espessura, resistência à tração, solubilidade e permeabilidade. Para o parâmetro cor a formulação contendo amido de mandioca e S. platensis, apresentou valor a* inferior devido à presença em maior concentração do componente S. platensis. O intumescimento foi crescente no decorrer do período de 60 min. Nenhuma das formulações de filmes apresentou inibição do crescimento microbiano pela técnica de disco difusão. O teor de S. platensis nas composições filmogênicas não foi suficiente para inibição microbiana. A formulação referente à mistura ternária em proporções iguais foi aplicada em pimenta Cambuci (Capsicum sp.) e por meio do acompanhamento do armazenamento em temperatura ambiente e refrigeração observou-se extensão da vida útil desta matéria-prima em 5 e 6 dias, respectivamente. Assim sendo, a utilização do revestimento desenvolvido mostrou-se viável.

Le projet Cigéo, mené par l’ANDRA, vise à permettre à l’horizon 2030 le stockage géologique des déchets les plus radioactifs du parc nucléaire français. Ces déchets, qui seraient placés dans des alvéoles souterraines de plusieurs centaines de mètres, sont susceptibles de relâcher de l’hydrogène gazeux (H2), un gaz inflammable dans l’air lorsque sa concentration dépasse 4%. Pour la sécurité des installations, il est indispensable de s’assurer que la concentration de H2 dans les alvéoles de stockage reste inférieure à sa limite de dangerosité. L’objectif de cette thèse, menée à l’ONERA, est de concevoir et réaliser un Lidar permettant de profiler à distance la concentration de H2 (0-4%), sur plusieurs centaines de mètres, avec une forte résolution spatiale (< 3 m), et de proposer ainsi un moyen non intrusif de détection et de prévention du risque lié à l’hydrogène. Le principe retenu est celui d’un Lidar Raman vibrationnel dans le domaine ultra-violet (355 – 420 nm). Pour sa conception, nous avons pris en compte les conditions particulières prévues dans les alvéoles de stockage. Une chaine de détection très sensible à comptage de photons a été choisie et mise en oeuvre, basée sur des détecteurs SiPM (Silicium Photomultiplier). La nécessité d’employer une voie de mesure de la vapeur d’eau, simultanément à l’hydrogène, a été mise en évidence et est liée au recouvrement partiel des spectres de diffusion Raman de H2 et H2O. Un analyseur spectral à trois voies de mesure (H2, H2O, et N2 utilisé comme référence) a été conçu et mis en place. Une méthode de traitement de signal en temps réel a enfin été réalisée pour visualiser les profils de concentrations de H2 et H2O. L’ensemble du système lidar a pu être testé dans une scène de portée réduite (100 m) permettant des relâchements d’hydrogène. Des mesures simultanées de profils de vapeur d’eau naturelle et de dihydrogène (0-2%) ont pu être démontrées avec succès à 85 m, avec une résolution spatiale et temporelle de 1 mètre et 1 minute respectivement, pour une détectivité de 600 ppm. / The CIGEO project, led by the ANDRA agency, aims at enabling future deep geological disposal of french nuclear waste packages. Those packages could be stored in hundred-meters long underground galleries, and may release hydrogen gas (H2), which is explosive at concentrations above 4% in the air. For safety concerns, it is important to ensure that H2 concentration remains well below the lower explosive limit. The objective of this thesis work, conducted at the ONERA agency, is to design and build a lidar which enable high-resolution (3 m) remote profiling of H2 concentration (0-4%) over hundreds of meters. Such a lidar could perform nonintrusive H2 detection and then prevent H2-related explosion risks. This lidar measures vibrational Raman scattering in the UV domain (355 – 420 nm). Its design takes into account the specific conditions expected in storage galleries. A highspeed and sensitive detection stage has been chosen, based on SiPM (Silicium Photomultiplier) technology in photon counting mode. Due to a spectral overlap between molecular hydrogen and water vapor Raman spectra, the need of a H2O measurement channel has been demonstrated. A three-channel spectral analyzer (H2, H2O and N2 used as reference) has been designed and implemented. Signal processing in real time has been developed to display H2 and H2O concentration profiles. This lidar has been tested in a reduced range scene (100 m) enabling hydrogen gas releases. Simultaneous measurements of concentration profiles of natural water vapor and hydrogen gas (0-2%) have been performed at 85 m with 1-meter and 1-minute resolution and a 600 ppm detectivity.

La vapeur d'eau atmosphérique joue un rôle clé dans le budget radiatif en Arctique, le cycle hydrologique et donc le climat. Mais sa mesure avec une précision reste un défi. La vapeur d'eau en Arctique se caractérise par une variabilité spatiale et temporelle qui n'est pas complètement comprise. Sa colonne atmosphérique total intégrée (TCWV) est étudiée dans cette thèse. Trois méthodes de mesures de la TCWV à distance sont testées et validées pour la région polaire. Cela inclut les mesures de TCWV aux bandes NIR/VIS/IR par les capteurs MODIS, SCIAMACHY, et AIRS embarqués sur satellites. Le cycle saisonnier de la TCWV à 19 stations polaires de référence est examiné suite à l'effet de la latitude, de la longitude en plus de l'effet continental/océanique. Les mesures utilisées ont été validées aux trois stations polaires via la comparaison à une base de données référentielle de TCWV convertis de retards de signaux GPS basés au sol. Les incertitudes et limites de mesures satellitaires sont évaluées par saison et par mois. Particulièrement, nous avons étudié l’effet de la présence de nuages sur les mesures des TCWV par satellites. Dans le NIR et dans le VIS, les mesures subissent une sensibilité accrues à la présence de nuages aux latitudes hautes en été. En plus, l’estimation de l’albédo est toujours un défi aux modèles d’inversion de la TCWV, surtout en présence de neige en régions cultivées. Suite aux résultats de la validation, la distribution et les tendances saisonnières de la TCWV au-dessus de toute l'Arctique ont été évalués via MODIS. Les tendances et anomalies accrues sont discutées principalement en réponse aux changements observés en Arctique au cours des 2001-2015 années, celles qui concernent la végétation, la couverture de neige, et la glace de mer. Les tendances accrues de la TCWV peuvent être liées à l’augmentation locale de surfaces vertes relative à la neige pendant les saisons transitoires. Des tendances augmentées de la TCWV étaient observables par MODIS, forcé par le réchauffement estival local pendant les vagues de chaleurs au temps de ciels clairs. Un déclin dramatique de la glace de mer près des côtes Sibériennes et de la cote du Beaufort a entraîné une augmentation locale observée de la TCWV en début d’automne. Une phase de réchauffement au niveau de l’archipel du Svalbard, persistant en toutes saisons sauf l’été, a entrainé également des quantités supplémentaires de la TCWV. La détection et justification de tendances est une tache toujours loin d’être accomplie. Les mesures en Arctique sont toujours en question, les mesures de la TCWV au-dessus de surfaces vertes en hiver, ou à travers du ciel nuageux en été sont des défis majeurs. / Atmospheric water vapour plays a key role in the Arctic radiation budget, hydrological cycle and hence climate, but its measurement with high accuracy remains an important challenge. Arctic water vapor is characterized by a spatial and temporal variability which is not completely understood yet. Its mass integrated in the atmospheric column (TCWV) is studied in this thesis. TCWV seasonal cycle at 18 polar stations is examined following the effect of latitude, longitude in addition to the continental effect. The measurements used in this thesis were validated at three polar stations, the satellites measurements of TCWV in the NIR/VIS/IR bands by MODIS/ SCIAMACHY/ AIRS sensors are compared to those obtained from ground based GPS signals delay. Their uncertainties and limitations are evaluated in season and month scales especially their sensitivities to the clouds presence. In NIR and VIS, the measurements undergo increased sensitivity to the presence of clouds at high latitudes in summer. In addition, albedo estimation is still a challenge to their TCWV inversion models, especially where canopies are snow-covered. Following the validation results, the distribution and seasonal trends of the TCWV over the entire Arctic was assessed via MODIS. Trends and anomalies are discussed mainly in response to changes in the Arctic vegetation, snow cover, and sea ice during 2001-2015. Increased trends in TCWV may be related to local increase of vegetated areas coincidently to snow cover decrease during transient seasons. Increased trends in TCWV were observed by MODIS, forced by local summer warming from many warm waves. A dramatic decline in sea ice near the Siberian and Beaufort coasts led to an observed local increase in TCWV in early fall. A warm-up phase in the Svalbard archipelago, persisting in all seasons except summer, also resulted in additional quantities of TCWV. The detection and justification of trends is a task still far from being accomplished. Arctic TCWV measurements are in question, TCWV measurements over green areas in winter, or through cloudy skies in summer are the major challenges.

Depuis 2012, les gaz d’échappement diesel sont considérés comme cancérigènes, ce qui représente un risque pour les travailleurs quotidiennement exposés à ces fumées. Cette étude s’intéresse plus particulièrement aux oxydes d’azotes (NOx) et au monoxyde de carbone (CO) présents dans l’échappement diesel. Actuellement, des solutions catalytiques permettent de réduire la concentration de sortie de ces composés mais elles ne sont pas viables pour les véhicules non routiers fonctionnant de façon discontinue et pour solutionner la problématique du « cold start ». La thèse s’est alors orientée vers l’adsorption sur des zéolithes. Dans un premier temps, sept zéolithes ont été choisies et l’étude de l’adsorption des corps purs en dynamique a montré qu’elles étaient peu efficaces dans la capture de NO et de CO mais qu’elles avaient de bonnes capacités d’adsorption vis à vis de NO2. L’étude plus poussée sur trois d’entre elles, Na Y, NH4 Y et H Y, a montré qu’en présence d’O2 et/ou de vapeur d’eau dans le flux gazeux, des réactions chimiques se produisent, conduisant notamment à la formation de NO2 et/ou de NO qui doivent alors être également adsorbé. Le rôle de la température d’adsorption a également été étudié sur la zéolithe Na Y. Son influence est importante à la fois sur la capacité d’adsorption et sur les cinétiques des réactions chimiques. Les capacités de rétention maximales des NOx sur la zéolithe Na Y sont obtenues à 30°C en présence d’O2 dans le flux gazeux et en absence totale d’eau. Afin d’améliorer la capture de NO et CO, il est possible d’estimer les capacités d’adsorption d’autres zéolithes en utilisant la modélisation moléculaire par Density Functional Theory (DFT) afin de calculer les chaleurs isostériques d’adsorption / Since 2012, diesel exhaust gases are considered to be carcinogenic, which is a risk to workers who are exposed to these fumes on a daily basis. This study focuses on nitrogen oxides (NOx) and carbon monoxide (CO) present in the diesel exhaust. Currently, catalytic solutions can reduce the outlet concentration of these compounds, but they are not viable for non road vehicles operating intermittently and to solve the problem of “cold start”. The thesis was then focuses on adsorption on zeolites. As a first step, seven zeolites were selected and the study of the adsorption of pure components in dynamics showed that they were ineffective in the uptake of NO and CO but they had good adsorption capacities for NO2. The further study on three of them, Na Y, NH4 Y and H Y, showed that in the presence of O2 and/or water vapor in the gaseous stream, chemical reactions occur, leading in particular to the formation of NO2 and/or NO which must then also be adsorbed. The role of adsorption temperature has also been studied on zeolite Na Y. Its influence is important on the adsorption capacity and on the kinetics of the chemical reactions. The maximum retention capacities of NOx on zeolite Na Y are obtained in presence of O2 in the gaseous mixture and in absence of water. In order to improve the uptake of NO and CO, it is possible to estimate the adsorption capacities of other zeolites by using molecular modeling by Density Functional Theory (DFT) to calculate the isosteric heats of adsorption

Made available in DSpace on 2014-06-11T19:31:04Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-07Bitstream added on 2014-06-13T20:01:31Z : No. of bitstreams: 1 sapucci_lf_dr_prud.pdf: 3782471 bytes, checksum: af4cccfc2f5cb3b6dd4ba86dfb21c180 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A quantificação do vapor d'água integrado na atmosfera (IWV - Integrated Water Vapor), ao contrário de outras variáveis meteorológicas, é algo que ainda se apresenta como um grande desafio para as Ciências Atmosféricas. Diversos mecanismos, envolvendo diferentes técnicas, têm sido empregados e testados para esse fim em diferentes regiões do globo por pesquisa dores das mais variadas áreas da ciência. Essa tese apresenta uma contribuição a esse tema ao empregar receptores GPS (Global Positioning System) em bases terrestres, localizados no Brasil, envolvendo instituições de pesquisa na área de Geodésia e de Meteorologia. Os objetivos principais desse trabalho são validar os valores do IWV obtidos a partir das observações GPS e contribuir com a viabilização da utilização de redes ativas de receptores GPS, existentes atualmente e futuras, no monitoramento do IWV como suporte às atividades da Meteorologia e Climatologia no Brasil. Os resultados obtidos mostram que, com a efetivação desse processo, poderá ser obtida uma fonte adicional de informações da umidade para Previsão Numérica de Tempo (PNT). Além disso, é mostrado também que a alta resolução temporal dos valores do IWV obtidos a partir das observações GPS pode contribuir para a melhoria dos resultados gerados por outras técnicas empregadas na mesma tarefa. Em contrapartida, um modelo de PNT é utilizado para gerar previsões da influência da troposfera nos sinais GPS, visando beneficiar aplicações GPS em tempo real. Os resultados gerados nesse trabalho são frutos da sinergia entre as duas áreas envolvidas e mostram que, atualmente, há boas perspectivas para essa parceria no Brasil. / Quantification of Integrated Water Vapor (IWV), unlike other meteorological variables, still represents a significant challenge to the Atmospheric Sciences. In this task several techniques using different mechanisms have been employed and tested in different regions of the planet. Many researchers from several areas of science have been involved in this process. This thesis presents a contribution to this theme, employing ground-based GPS receivers installed on Brazilian territory, involving Geodesy and Meteorology research institutes. The main aim of this work is to contribute in order to make enable the use of the existing networks of continuously operating GPS receivers, and those that will be installed in the future, in IWV monitoring to support meteorological and climatological activities in Brazil. The results generated show that in this process it is possible to obtain an additional source of humidity information for Numerical Weather Prediction (NWP). Furthermore, the prospect of using the ground-based GPS receivers to monitor atmospheric water vapor is promising because thehigh temporal resolution of IWV values from GPS observations can improve the results generated from other techniques employed in the same task. At the same time, a NWP model is applied to generate predictions of the atmosphere's influence over radiofrequency signals, to improve real time GPS applications. The results of this work stem from the synergy between the two areas of science involved. They show that the current outlook for this partnership in Brazil is good, and that both Meteorology and Geodesy will benefit.

No description available.

Paper and cellulosic materials hold a good promise of being candidates for flexible packaging materials provided suitable barrier properties such as water repellence and grease resistance are imparted to them. One of the methods to achieve these objectives is to surface modify paper/cellulose by applying thin fluorocarbon coatings on the surface. Fluorocarbon thin films produced by plasma enhanced chemical vapor deposition (PECVD) offer several advantages over the films produced by conventional polymerization means. Plasma deposited films are pinhole-free, chemically inert, insoluble, mechanically tough, thermally stable and highly coherent and adherent to variety of substrates. In this work, we investigate the use of PECVD technique to produce barrier films on paper and cellulosic materials. These films, with composition and properties not much different from PTFE, repel water and act as a good barrier to lipophilic materials. Two different monomers, pentafluoroethane (PFE; CF3CHF2) and octafluorocyclobutane (OFCB; C4F8), were investigated and compared in terms of deposition rates and final film properties. Various analytical techniques (XPS, FT-IR, SEM, Ellipsometry, Contact Angle Goniometry, etc.) were used to characterize the fluorocarbon films. The fluorocarbon coated paper exhibited hydrophobic character as evidenced by high water contact angles. Although the films allow water vapor diffusion, the films are hydrophobic and are not wetted when liquid water contacts these layers. Based on various thickness of these films deposited on surface of cellulose, there was a minimum PFE film thickness required to achieve a stable hydrophobic behavior. The fluorocarbon films investigated in this work also exhibited good resistance to lipophilic materials (e.g. oils, fatty acids, etc.). While techniques such as oleic acid penetration and TAPPI "oil-kit" test are commonly used in paper industry to qualitatively test the grease barrier properties of paper/cellulose, this work attempts to quantify the grease barrier properties of fluorocarbon coated paper using techniques such as magnetic resonance imaging (MRI) and quartz crystal microbalance (QCM). Finally, the feasibility of deposition of dual layer films by PECVD was investigated using PFE and n-isopropylacrylamide (NIPAAM) as precursors for applications in barrier packaging and printing.