Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Técnicas de limpeza química ou mecânica são comumente empregadas para evitar a formação de biofilmes e problemas associados com a colonização de superfícies por micro-organismos. Neste trabalho, amostras de aço inox 304L foram submetidas a ensaios acelerados de crescimento de biofilme, o qual foi posteriormente removido por tratamentos de limpeza e desinfecção (choque térmico com água a 70C por 1h, limpeza com ácido fosfórico 20 % v/v por 30min e desinfecção com peróxido de hidrogênio 0,17 % v/v por 1h). Com o objetivo de verificar a influência destes tratamentos na remoção do biofilme, este foi caracterizado (por quantificação microbiana e análises de espectroscopia de impedância eletroquímica - EIE), antes e após a aplicação dos tratamentos. Dois casos foram estudados. No primeiro caso, simularam-se condições presentes em tubulações de ambientes hospitalares e sistemas de distribuição de água quente. O micro-organismo utilizado foi a bactéria Serratia marcences. O processo de formação de biofilme e posterior limpeza e desinfecção foi realizado de modo contínuo durante 15 semanas. Os resultados de quantificação microbiana e de EIE mostraram que desde a primeira semana de exposição e ao longo dos ensaios, formou-se um biofilme aderente à superfície do aço e que o emprego dos tratamentos de limpeza e desinfecção não foi eficaz na remoção do biofilme. Em um segundo caso, simularam-se condições presentes em tubulações da indústria de água mineral, empregando-se a bactéria Pseudomonas aeruginosa. Neste caso, as técnicas de limpeza e desinfecção foram aplicadas individualmente e em conjunto. A aplicação de choque térmico, assim como da limpeza ácida, sobre um biofilme com 72 h de formação foi capaz de eliminar as bactérias viáveis, presentes na superfície do aço. Entretanto, a desinfecção com peróxido de hidrogênio não foi capaz de eliminá-las. Nas duas condições, porém, as análises de EIE do sistema aço/biofilme mostraram que o mesmo não foi completamente removido da superfície do metal. Correlacionando os dois casos, pode-se inferir que a superfície do aço inox 304L é rapidamente colonizada pelas duas espécies microbianas e que as técnicas de limpeza e desinfecção são capazes de reduzir e até eliminar as células viáveis, embora não removam completamente o biofilme da superfície. Por outro lado, é importante ressaltar que fatores como a arquitetura, espessura e porosidade do biofilme, e propriedades intrínsecas da superfície, são fatores que afetam os valores de impedância medidos, sendo necessário considerá-los na análise, tanto da formação do biofilme, quanto dos efeitos dos procedimentos de limpeza e desinfecção / Techniques for chemical or mechanical cleaning are usually employed to prevent the formation of biofilm and the problems associated with the colonization of surfaces by micro-organisms. In this work, samples of 304 L stainless steel were submitted to experiments of accelerated growth of biofilm, which was subsequently removed by cleaning and disinfection treatment (heat shock with water at 70 C for 1h, cleaning with phosphoric acid 20% v/v for 30 min and disinfection with hydrogen peroxide 0,17% v/v for 1h). In order to verify the influence of these treatments on biofilm removal, analyses of microbial quantification and electrochemical impedance spectroscopy (EIS), before and after the treatments were employed. Two cases were studied. In the first case, it was simulated the conditions found in piping for hospital environment and systems for the distribution of hot water. The micro-organism used was the bacteria Serratia marcences. The process of biofilm formation and subsequent cleaning and disinfection was performed continuously for 15 weeks. The results of measurement of microbial and EIS showed that since the first week of exposure and during the testing, an adherent biofilm was formed on the steel surface and that the use of cleaning and disinfecting treatments were not effective in removing biofilm. In a second case, it was simulated the conditions present in the pipes of the mineral water industry, using the bacterium Pseudomonas aeruginosa. In this case, the cleaning and disinfection techniques were applied individually and as a whole. The application of heat shock, as well as acid cleaning, to the biofilm formated after 72 h was able to eliminate the viable bacteria present in the steel surface. However, disinfection with hydrogen peroxide was not able to eliminate them. In both conditions, however, the EIS analysis of the steel/biofilm system showed that it was not satisfactorily removed from the metal surface. Comparing the two cases, it can be inferred that the surface of 304L stainless steel is rapidly colonized by the two microbial species studied and that the cleaning and disinfection techniques are able to reduce and even eliminate viable cells, although they could not completely remove the biofilm from the surface. On the other hand, it is important to note that factors such as properties of the electrode surface (roughness, porosity and adsorption), the electrode potential, and the architecture, thickness and porosity of the biofilm, are factors that affect the measured impedance values, it is necessary to consider them in the analysis of biofilm formation and effects of cleaning and disinfection

Os produtos podem causar impactos negativos ao meio ambiente em uma das suas etapas do ciclo de vida, quais sejam: aquisição de matéria-prima, fabricação, distribuição, uso e disposição final. A integração dos aspectos ambientais no projeto e no desenvolvimento de produto busca prevenir e minimizar os possíveis impactos ao longo de seu ciclo de vida. Esses impactos variam quanto à categoria, magnitude, extensão e duração. A principal metodologia para avaliar os impactos ambientais do ciclo de vida do produto é a Avaliação do Ciclo de Vida (ACV). Contudo há diversos métodos e formas de aplicações desta metodologia. O primeiro objetivo é identificar os principais métodos da ACV, por meio de uma revisão sistemática, O segundo é realizar um estudo de caso comparativo da ACV entre dois tipos de cestos (de plástico e de aço inox) utilizados nas lavadoras de roupas automáticas, identificando os potenciais impactos ambientais, baseado no método EDIP. Os principais métodos identificados na revisão sistemática foram: Ecoindicator 99, EPS, CML Ecological Footprint e EDIP. A comparação do ciclo de vida dos dois cestos demonstra que, para as categorias de impactos de potencial de aquecimento global, acidificação, eutrofização, ecotoxidade e toxidade humana, o cesto inox tem uma maior contribuição para os potencias impactos ambientais em relação ao cesto de plástico, principalmente devido à maior distância transportada da matéria-prima do aço até a fabricação do cesto. / The products can cause negative impacts to the environment in one of their stages of the life cycle, which are: raw material acquisition, production, distribution, use and final disposition. The integration of the environmental aspects in the project and in the product development it looks for to prevent and to minimize the possible impacts along his life cycle. Those impacts vary as for the category, magnitude, extension and duration. The main methodology to evaluate the environmental impacts of the life cycle of the product is the Life Cycle Assessment (LCA). However there are several methods and forms of applications of this methodology. The first objective is to identify the main methods of LCA, through a systematic revision, THE second is to accomplish a study of comparative case of LCA among two types of baskets (of plastic and of stainless steel) used in the washers of automatic clothes, identifying the potentials environmental impacts, based on the method EDIP. The main identified methods in the systematic revision were: Echo-indicator 99, EPS, CML Ecological Footprint and EDIP. The comparison of the cycle of life of the two baskets demonstrates that, for the categories of impacts of potential of global warming, acidification, nutrient enrichment, ecotoxicity and human toxicity, the basket stainless steel has a larger contribution for the potencies environmental impacts in relation to the basket of plastic, mainly due to the largest transported distance of the raw material of the steel to the production of the basket.

This work was carried out aiming the study of the corrosion effect by the water produced, which is associate to the production of oil, mainly in wells in mature fields, such as the UN-SEAL. It is noteworthy that this water is known in the petroleum industry as water produced. The sample of produced water used was of the production field of Siririzinho I on-shore in Sergipe, which showed in its physicalchemical analysis, high levels of salinity among other compounds, which makes it an extremely aggressive corrosion for materials used in the petroleum industry. In this research the materials used in this work were the carbon steel ASTM A283 Gr C, the stainless steel ASTM A240 type 316L with and without coating of hard chrome and the duplex stainless steel ASTM A890 Gr 1B. The sample used had chemical compositions issued by manufacturers according to ASTM, in addition, microhardness tests and metallographic tests with the use of optical microscopy were used to characterize these materials. For the study of effect of the water produced attack in the materials, was designed and built a test circuit, which allowed the insertion of samples for monitoring and data collected of mass and thickness parameters , and the monitoring visual corrosion during the test. The samples were machined in two geometric shapes (rectangular plate and disk) to enable and facilitate the testing of weight and thickness measurement by applying the ultrasound technique and of the depth measurement. From the collected data was possible to calculate by established criteria using the standard NACE RP 0775, the rate of uniform corrosion by mass loss and by its development the rate of corrosion by thickness loss, that is the same form used for the calculation of corrosion rate by pit in agreement with the standard Petrobras N- 2364. By comparing the corrosion rates obtained in the study, can better evaluate the possible perspectives of application of the materials in contact with the corrosive fluid. / Este trabalho foi desenvolvido objetivando o estudo do efeito da corrosão por meio da água que está associada à produção do petróleo, principalmente em poços de campos maduros, como é o caso da UN-SEAL. Ressalta-se que esta água é conhecida na indústria do petróleo como água produzida. A amostra da água produzida utilizada foi a do campo de produção de Siririzinho I do ativo de produção de Sergipe Terra que apresentou em sua análise físico-química, altos teores de salinidade dentre outros compostos que a torna um meio extremamente agressivo à corrosão para os materiais utilizados na indústria do petróleo. Nesta pesquisa os materiais estudados foram os aços: carbono ASTM A283 Gr. C, o inox ASTM A240 tipo 316L sem e com revestimento de cromo duro e o inox duplex ASTM A890 Gr. 1B. As amostras utilizadas possuíam suas composições químicas emitidas pelos fabricantes de acordo com a norma ASTM, além disto, ensaios de microdureza e ensaios metalográficos com o uso da microscopia óptica foram utilizados na caracterização destes materiais. Para o estudo do efeito do ataque da água produzida nos materiais, foi projetado e construído um circuito de teste, o qual permitiu a inserção de corpos de prova para monitoramento e coleta de dados dos parâmetros de massa e de espessura, além do acompanhamento visual da corrosão ao longo do teste. Os corpos de prova foram usinados em duas formas geométricas (disco e placa retangular) de modo a permitir e facilitar a realização dos ensaios de medição de massa, medição de espessura através do ultra-som e da medição de profundidade. De posse dos dados coletados foi possível calcular através de critérios estabelecidos pela norma NACE RP 0775, a taxa de corrosão uniforme por perda de massa e por seu desenvolvimento a taxa de corrosão por perda de espessura, que é a mesma forma utilizada para o cálculo da taxa de corrosão por pites segundo a norma Petrobras N-2364. Através das taxas de corrosão obtidas no estudo, pode-se avaliar quais as possíveis perspectivas de aplicação dos materiais em contato com o fluido corrosivo.

Le polissage est un procédé d’usinage par abrasion qui vise à établir une micro-géométrieprécise sur les surfaces de solides. Pour introduire les spécificités de ce procédé, un tourd’horizon sur l’usinage par abrasion est proposé. Il en découle les paramètres pouvantcaractériser une opération de polissage. Les études scientifiques existantes sont synthétisées etanalysés au regard des objectifs poursuivis. De manière à faire émerger une méthodologiepour établir des modèles et des bases de données dédiées au polissage, un banc expérimental aété mis en place et des essais ont été menés sur une tôle en inox 316L avec un abrasifstructuré de forme pyramidale. Une méthode de mesure de l’usure des pyramides abrasives aété mise au point. Les premiers essais ont mis en évidence la nécessité pour les grains abrasifsd’exercer sur la matière une pression supérieure à une valeur minimale. Un modèle deconsommation matière issu de la loi de Preston a été présenté et validé par des essais. L’étudepar des plans d’expériences factoriels complets des efforts induits, de la rugosité au traversdes critères proposés par la norme ISO et de la mouillabilité a permis de mettre en évidencel’influence prépondérante de la taille des grains abrasifs. Par contre, la pression exercée parles grains, leur vitesse de défilement et le taux d’usure des pyramides abrasives n’ont qu’unrôle secondaire sur ces critères. Ces résultats constituent de précieuses indications pour lesbureaux des méthodes devant établir des gammes de polissage. / The polishing is a process of manufacturing by abrasion which aims at establishing a precisemicro-geometry on the surfaces of solids. To introduce the specificities of this process, anoverview on the manufacturing by abrasion is proposed. As a result, the parameters which cancharacterize an operation of polishing are identified. The existing scientific studies aresynthesized and analysed with regard to the pursued objectives. For the testing, an experimenttest bench was developed. The proposed methodology is applied on the polishing process ofthe AISI 316L using pyramidal abrasive belts. A measurement method of the abrasivepyramids wear is finalized. A method of measuring the abrasive pyramids wear is provided. Aremoving material rate model based on the Preston's law is presented and experimentallyvalidated. A study based on the design of experiment is conducted using as output the cuttingforces, the roughness and the wettability criteria. The results point out the dominatinginfluence of the size of the abrasive grains. On the other hand, the study indicates the fact thatthe applied pressure on the abrasive grains, the belt speed and the abrasive level do not playan important role on the previously cited characteristics. On the other hand, the studyhighlights that the applied pressure on the abrasive grains, the belt speed and the abrasivelevel do not have a significant effect on the previously cited characteristics. These resultsconstitute valuable indications for the industrial polishing process optimization.

Le nettoyage des surfaces métalliques est nécessaire dans différents domaines de l'industrie moderne. L'industrie nucléaire cherche de nouvelles méthodes de décontamination des surfaces oxydées, et les installations thermonucléaires nécessitent le nettoyage des composants face au plasma pour enlever la couche déposée contenant tritium. L'ablation laser est proposée comme une méthode efficace et sûre pour le nettoyage des surfaces métalliques et leur décontamination. Le facteur important influençant le chauffage et l'ablation laser est la distribution en profondeur de l’intensité laser. Le modèle de propagation de la lumière dans une couche diffusant sur un substrat métallique est développé et appliqué pour analyser les caractéristiques de distribution de lumière. Pour simuler les surfaces contaminées, l'inox AISI 304L a été oxydé par laser et chauffé dans un four. La contamination radioactive de la couche d'oxyde a été simulée par l'introduction d’europium et / ou de sodium. Un facteur de décontamination de plus de 300 a été démontré avec le régime de nettoyage optimal trouvé. Une diminution de la résistance à la corrosion a aussi été montrée après un nettoyage laser. Les seuils d'ablation des surfaces ITER-like (représentatives d’ITER) ont été mesurés. Une vitesse de nettoyage de 0,07 m2/W∙h a été trouvée. Pour les surfaces miroir, les seuils de dommages étaient déterminés pour éviter les dommages lors du nettoyage au laser. La possibilité de restaurer la réflectivité après le dépôt d’une couche mince de carbone a été démontrée. Les perspectives de développement ultérieur de nettoyage laser sont discutées. / Metal surface cleaning is highly required in different fields of modern industry. Nuclear industry seeks for new methods for oxidized surface decontamination, and thermonuclear installations require the cleaning of plasma facing components from tritium-containing deposited layer. The laser ablation is proposed as an effective and safe method for metal surface cleaning and decontamination. The important factor influencing the laser heating and ablation is the in-depth distribution of laser radiation. The model of light propagation in a scattering layer on a metal substrate is developed and applied to analyse the features of light distribution. To simulate the contaminated surfaces, the stainless steel AISI 304L was oxidized by laser and in a furnace. Radioactive contamination of the oxide layer was simulated by introducing europium and/or sodium. The decontamination factor of more than 300 was demonstrated with found optimal cleaning regime. The decreasing of the corrosion resistance was found after laser cleaning. The ablation thresholds of ITER-like surfaces were measured. The cleaning productivity of 0.07 m2/hour∙W was found. For mirror surfaces, the damage thresholds were determined to avoid damage during laser cleaning. The possibility to restore reflectivity after thin carbon layer deposition was demonstrated. The perspectives of further development of laser cleaning are discussed.

Une des solutions envisagées par les motoristes pour améliorer le rendement des turbomoteurs consiste à réduire le jeu en fonctionnement dans les deux systèmes d’air des turbomachines. Plus particulièrement dans le système d’étanchéité d’air secondaire, la réduction du jeu entre les parties fixes et tournantes améliore le contrôle des étanchéités du moteur et les niveaux de refroidissement entre les différents modules des turbomoteurs, mais entraînent des interactions indésirables entre les différents composants. Les systèmes d’étanchéité dynamiques sont composés de joints labyrinthes couplés à un revêtement abradable sacrificiel en vis-à-vis, qui offre la particularité de s’user préférentiellement en préservant la majeure partie du système d’étanchéité en évitant une usure de la partie tournante. L’objectif de cette thèse est de reproduire et d’étudier, par l’intermédiaire d’un banc technologique haute vitesse spécialement conçu pour l’étude, les interactions labyrinthe-abradable appliquées au couple acier inoxydable/Al-Si 6%, dans des conditions de fonctionnement d’un turbomoteur. Une instrumentation spécifique est développée sur le banc et apporte à l’étude les données expérimentales manquantes visant à la caractérisation des interactions labyrinthe-abradable. Une analyse tribologique, basée sur le concept de troisième corps, est menée afin d’identifier les différents débits de matière puis de décrire les étapes successives des mécanismes d’usure (circuit tribologique) du revêtement Al-Si 6%. L’influence des paramètres de pilotage de l’interaction et de la géométrie du joint a été étudiée. Enfin, une étude statistique basée sur l’iconographie des corrélations, permet de modéliser le comportement global du système labyrinthe-abradable, d’identifier les paramètres influents du système et d’apporter des critères pour une potentielle surveillance des interactions. Ces travaux de thèse ont été réalisés dans le cadre d’une collaboration entre TURBOMECA Bordes (groupe SAFRAN), et le Laboratoire Génie Production (LGP) de Tarbes. / S of turbomachinery. Especially in the secondary air sealing system, the tight clearance between the stationary and rotating parts improves control of engine seals and cooling levels between the different modules of the engines but may cause undesirable interactions between the static and rotating components. Dynamic sealing systems are composed of labyrinth seals coupled to a sacrificial abradable coating, which can accommodate interactions to preserve the global geometrical seal integrity. The objective of this thesis is to study and reproduce, through a technological high speed test rig specifically designed for the study, the labyrinth-abradable interactions applied to stainless steel/Al-Si 6% couple, under similar turbo-engine operating conditions. A suitable instrumentation is developed on the test ring to complete missing experimental data to characterize abradable labyrinth interactions. A tribological study, based on the third body concept, is proposed to identify wear mechanisms process of the Al-Si 6% coating. The influence of interaction control parameters and the seal geometry was investigated. Finally, a statistical study, based on the iconography of the correlation, is proposed to model the overall labyrinth-abradable system behavior and to identify influential parameters of the system and provide suitable criteria to monitor labyrinth seal interactions. This work was achieved within the framework of cooperation between TURBOMECA Bordes (SAFRAN Group), and the Laboratoire Génie de Production (LGP) de Tarbes.