Cette thèse de doctorat est consacrée à l’étude sur le risque d’inflammation de gaz imbrûlés au niveau du système de ventilation suite à un incendie dans un milieu confiné sous-ventilé. La caractérisation de l’état de stratification des fumées et du désenfumage apparaît aussi comme un objectif. Lors d’un incendie en milieu clos, la quantité d’oxygène présente dans le local peut devenir insuffisante, engendrant une combustion incomplète. Des gaz chauds imbrûlés résiduels peuvent alors s’accumuler dans le local et être évacués par la ventilation d’extraction. Lorsque ces derniers sont mis en présence d’air apporté par un autre conduit de ventilation, ils peuvent s’enflammer spontanément et générer une déflagration pouvant rompre le confinement dynamique des matières dangereuses, situation inacceptable pour la sûreté des installations nucléaires. Cette inflammation dépend de la quantité des imbrûlés, de la température dans la gaine d’extraction et de la concentration minimale en oxygène. L’objectif de cette étude est de quantifier et d’analyser ce risque par l’étude aérodynamique de la flamme et par le niveau de confinement dynamique afin de choisir le type de ventilation présentant le moins de risque. Cette étude, à la fois numérique et expérimentale, permet d’améliorer la compréhension de l’influence de la richesse globale liée au niveau de confinement de l’enceinte sur la production d’imbrûlés comme CO, H2 et fuel. Elle permet par la suite de mettre en évidence l’influence de celle-ci sur le risque d’inflammation de gaz imbrûlés au niveau du système de ventilation. / This doctoral thesis is devoted to the study of the risk of ignition of unburnt gases in the ventilation system after a fire in an under-ventilated confined enclosure. The characterization of the state of lamination of smoke and smoke extraction also appears as an objective. In a closed fire, the amount of oxygen present in the room may become insufficient leading to incomplete combustion. Residual unburnt hot gases can then accumulate in the room and be evacuated by extraction ventilation. When the latter are placed in the presence of air supplied by another ventilation duct, they can ignite spontaneously and generate a deflagration capable of breaking the dynamic containment of hazardous materials, an unacceptable situation for the safety of nuclear installations. This ignition depends on the quantity of the unburned gases, the temperature in the extraction sheath and the minimum concentration of oxygen. The objective of this study is to quantify and analyze this risk through the aerodynamic study of the flame and the level of dynamic confinement in order to choose the ventilation posing the least possible risk. This study, both numerical and experimental, makes possible to improve the understanding of the influence of the equivalence ratio linked to the level of confinement of the enclosure on the production of unburned like CO, H2 and fuel. Then, it makes possible to highlight the influence of the latter on the risk of ignition of unburnt gases in the ventilation network.

The current state of earth building in Czeh Republic is described in this work. The results are based on a research made in several villages. Reconstruction of traditional countryside building made from unburned earth should be made very sensitive with respect to architectural and technical solution and in accordance with environmental requirements and wishes of investor.

Submitted by Milena Rubi (milenarubi@ufscar.br) on 2017-08-08T18:02:30Z No. of bitstreams: 1 CACURO_Thiago_2016.pdf: 32188052 bytes, checksum: 4ea1d6b1518db8bbf23e24ea2e2a94d7 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-08T18:03:10Z (GMT) No. of bitstreams: 1 CACURO_Thiago_2016.pdf: 32188052 bytes, checksum: 4ea1d6b1518db8bbf23e24ea2e2a94d7 (MD5) / Approved for entry into archive by Milena Rubi (milenarubi@ufscar.br) on 2017-08-08T18:03:16Z (GMT) No. of bitstreams: 1 CACURO_Thiago_2016.pdf: 32188052 bytes, checksum: 4ea1d6b1518db8bbf23e24ea2e2a94d7 (MD5) / Made available in DSpace on 2017-08-08T18:03:21Z (GMT). No. of bitstreams: 1 CACURO_Thiago_2016.pdf: 32188052 bytes, checksum: 4ea1d6b1518db8bbf23e24ea2e2a94d7 (MD5) Previous issue date: 2016-03-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / The ashes resulting from the burning of sugarcane bagasse is a heterogeneous material and has various applications as an adsorbent. To enhance and assist in prospecting new applications is critical to better understand the properties of the material. In this work, its morphological, spectroscopic and elemental characterization of the ashes of sugarcane bagasse from three different plants and two different harvests and the prospect of its use as an adsorbent. The particles of the ash were separated according to their density and in order to characterize, FTIR was used in the investigation of chemical groups present in the samples, additionally to the SEM and EDS elemental and morphological characterization of the particles present in the samples. Cenospheres, spherical particles present in ash, were identified as coreshell structure, where the core is a mixed metal oxide and the shell is a layer of silicon dioxide. The correlation between the ratio of the relative abundance between the carbonyl and hydroxyl groups and the mass distribution of the granulometric extracts were used as indirect measure of the level of oxidation of the samples. The ashes’ adsorption capacity showed affinity for the methylene blue dye with an adsorption capacity of 39 mg of dye per gram of ash used, in contrast to the low adsorption of potassium chromate solution, 1.2 mg per gram of ash. / As cinzas oriundas do processo de queima do bagaço de cana-de-açúcar são um material heterogêneo e com diversas aplicações, como a adsorção. Para potencializar e auxiliar na prospecção de novas aplicações é fundamental conhecer melhor as propriedades do material. Neste trabalho foi feita esta caracterização morfológica, espectroscópica e elementar das cinzas do bagaço da cana-de-açúcar provenientes de três diferentes usinas e duas diferentes safras e a prospecção de seu uso como adsorvente. As partículas das cinzas foram separadas de acordo com sua densidade e para a caracterização foi utilizada a técnica de FTIR na investigação dos grupos químicos presentes nas amostras e MEV juntamente com o EDS para a caracterização morfológica e elementar. As cenosferas, partículas esféricas presentes nas cinzas, foram identificadas como estruturas coreshell onde o core é composto por um misto de óxidos metálicos e o shell composto por dióxido de silício. A correlação entre a razão da abundância relativa entre os grupos de carbonila e hidroxila e a distribuição mássica dos extratos granulométricos, foi usada como medida indireta do nível de oxidação das diferentes amostras. Quanto à sua capacidade de adsorção, as cinzas mostraram afinidade na adsorção do corante azul de metileno com uma capacidade de adsorção de 39mg de corante por grama de cinza usada em contraste com a baixa adsorção apresentada para a solução de cromato de potássio com 1,2 mg por grama de cinza.

The theme of this thesis are surfaces made of unburned earth and used in architecture. The thesis focuses mainly on detailed mapping and analysis of the present state. However, it does not omit the historical roots of earthen surfaces in the area of today`s Czech Republic. In these roots it looks for connections with contemporary practice. The thesis deduces conclusions from thorough evaluation of the present situation – it shows perspectives and possible drift of the future development of earthen surfaces. Both in the field of architecture and in areas broadening this field.