Made available in DSpace on 2014-06-11T19:23:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-02-25Bitstream added on 2014-06-13T19:30:05Z : No. of bitstreams: 1 marao_hf_me_araca.pdf: 3083195 bytes, checksum: 286d537c00737b1b6f019da2785d2ccc (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A clínica tem mostrado que a maioria dos reimplantes dentários é tardia e nessa condição há necrose das células do ligamento periodontal e as reabsorções patológicas podem se instalar e levar à perda do dente. O objetivo do trabalho foi avaliar o MTA e o Ca(OH)2, no interior dos tecidos, após a reabsorção radicular externa em reimplante tardio de dente de rato. Foram utilizados 20 ratos (Rattus norvegicus albinus) machos que tiveram o incisivo direito extraído e mantido em meio seco por 60 minutos. Em seguida, a papila dentária, o órgão do esmalte, a polpa dentária e o ligamento periodontal foram removidos. Os dentes foram imersos em solução de fluoreto de sódio fosfato acidulado a 2% pH 5,5, por 10 minutos. Em seguida os canais foram secos e divididos em 2 grupos: Grupo I - canais radiculares foram preenchidos com pasta de Ca(OH)2 e soro fisiológico e Grupo II - com MTA. Os alvéolos foram irrigados com soro fisiológico e os dentes reimplantados. Após 80 dias foi possível observar extensas áreas de reabsorção por substituição e algumas inflamatória nos dois grupos experimentais. Houve uma reação inflamatória mais intensa em contato com o Ca(OH)2 quando comparado ao MTA. No fundo do alvéolo houve maior neoformação óssea no grupo do MTA, porém não houve diferença estatisticamente significante entre os grupos. È possível concluir que o MTA pode ser uma opção clínica viável para a obturação de dentes tardiamente reimplantados sujeitos à reabsorção radicular externa devido a sua biocompatibilidade com os tecidos / Clinical practice has shown that most of reimplanted teeth are late, this condition produce necrosis of periodontal ligament cells and the pathological resorption may occur and produce dental loss. The aim of this study was to assess the biological behavior of MTA and Ca(OH)2, within the tissues after external root resorption in delayed late reimplanted rat teeth. Twenty male rats (Rattus norvegicus albinus) were used. The upper right incisor was extracted and was kept in a dry environment for 60 minutes. Then, the dental papilla, the enamel organ, the dental pulp and the periodontal ligament were removed. The teeth were immersed in 2% acidulous sodium fluoride solution pH 5.5 for 10 minutes. After that, the canals were dried and divided into 2 groups: Group I - the canals were filled with Ca(OH)2 and saline and Group II - with MTA. Sockets were irrigated with saline solution and the teeth were reimplanted. After 80 days was possible to observe large areas of replacement resorption and some inflammatory root in both groups There was more intense inflammatory reaction in contact with Ca(OH)2 when compared to MTA. At the bottom of the alveolar socket, bone neoformation was greater in the group of MTA, but there was no statistically significant difference between the groups. It’s possible to conclude that MTA may be a viable clinical option for filling of late dental reimplanted subject to external root resorption due to its biocompatibility with the tissues

Made available in DSpace on 2014-06-11T19:23:45Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-11-20Bitstream added on 2014-06-13T19:09:56Z : No. of bitstreams: 1 negri_mr_me_araca.pdf: 1985453 bytes, checksum: df4e54eaae2a021fb0017e21e54aaedb (MD5) / O maior problema da terapêutica de dentes reimplantados está relacionado às reabsorções radiculares, e muitas pesquisas são realizadas no sentido de se prevenir e/ou tratar essas complicações. O objetivo deste trabalho foi avaliar histomorfologicamente a resposta tecidual de dentes anteriores de ratos reimplantados tardiamente, obturados com pasta de hidróxido de cálcio, Sealapex e Endoffil. Para a realização do estudo foram utilizados 30 ratos, divididos em 3 grupos de 10 animais, que tiveram o incisivo superior direito extraído e mantido em meio seco, por 60 minutos. Em seguida, a papila dentária, o órgão do esmalte, a polpa dentária e o ligamento periodontal foram removidos. Após esse procedimento, os dentes foram imersos em solução de fluoreto de sódio fosfato acidulado a 2% pH 5,5, por 10 minutos. Logo depois, os canais foram secos com cone de papel absorvente e divididos em três grupos de acordo com o material obturador. Grupo I - os canais radiculares foram preenchidos com pasta de hidróxido de cálcio e propilenoglicol, Grupo II - com cimento Sealapex e no Grupo III - com cimento Endofill. Os alvéolos foram irrigados com soro fisiológico e os dentes reimplantados. Os resultados revelaram presença de reabsorção por substituição, inflamatória e anquilose nos três grupos experimentais. Embora a reabsorção inflamatória estivesse presente em menor quantidade no grupo I, não houve diferença estatisticamente significante entre os três grupos experimentais. A partir desses resultados, foi possível concluir que a obturação dos canais apenas com cimento obturador Sealapex ou Endofill não apresentou vantagem em relação ao hidróxido de cálcio. / The largest problem of the therapeutic of teeth reimplantation is related to the root resorption and many researches are accomplished with the intention of prevent and or to treat those complications. The objective of this study was to evaluate the tissue reaction to delayed reimplantation of endodontically treated rats teeth with calcium hydroxide, Sealapex and Endoffil. Thirty rats were used in this study, divided in 3 groups of 10 animals, which had their right upper incisor extracted and maintained in dry storage, for 60 minutes. Then, the dental papilla, the enamel organ, the dental pulp and the periodontal ligament were removed. After these procedures, the teeth were immersed in solution of 2% sodium fluoride phosphate acidulated pH 5,5 for 10 minutes. The root canals were dry with cone of absorbent paper and divided in three groups according to the filling material. Group I - the root canals were filled out with Calcium Hydroxide paste and propylene glycol. Group II - Sealapex cement and the Group III - Endofill cement the teeth sockets was irrigated with saline solution was previously realized to the reimplantation. The results showed replacement resorption, inflammatory and ankylosis in the three experimental groups. Although the inflammatory resorption was present in smaller amount in the group I there was not statistically differences among the three experimental groups. It can be concluded that the root canal filling with Sealapex and Endofill cement didn't present advantage in relation to the calcium hydroxide.

Made available in DSpace on 2014-06-11T19:24:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-31Bitstream added on 2014-06-13T18:52:34Z : No. of bitstreams: 1 arruda_dp_me_botfca.pdf: 628799 bytes, checksum: c0a1f52e914545883936131898e973ff (MD5) / Existem vários extratores que avaliam a disponibilidade de silício no solo. Nos Estados Unidos utiliza-se como extrator químico o ácido acético 0,5 mol L-1 , o qual já foi usado no Brasil, mas recentemente foi substituído pelo cloreto de cálcio 0,01 mol L-1, o mesmo utilizado na Austrália. Os extratores, de forma geral, são dependentes das características físicas do solo, principalmente do teor de argila, e podem subestimar ou superestimar os teores de silício no solo. Na literatura não há relatos de extratores de silício que se assemelhem às raízes das plantas, como é o caso da resina trocadora de ânions usada na extração do fosfato do solo. Dessa forma, o objetivo deste trabalho foi avaliar extratores químicos que correlacionem o silício disponível no solo com o silício absorvido por plantas de cana-de-açúcar, cultivada em solos de textura arenosa, média e argilosa. Foram avaliados 8 extratores com o objetivo de selecionar aqueles que melhor avaliam os diferentes tipos de solos encontrados no Brasil. Os extratores utilizados foram CaCl2 0,01 Mol L-1 (Padrão), CaCl2 0,01 Mol L-1 (modificado), ácido acético 0,5 Mol L-1, KCl 0,01 Mol L-1, resina trocadora de íons, água, tampão acetato de sódio pH 4,0 e HCl 0,01 Mol L-1. As amostras foram coletadas entre março e dezembro de 2007 em áreas cultivadas com a cultura da cana-de-açúcar nas Usinas Guairá (Guairá-SP) e Colombo (Ariranha - SP). No momento do corte de cana-de-açúcar, em cada unidade experimental, foram realizadas coletas de solo nas profundidades 0-0,20 m e 0,20-0,40 m, para avaliação de pH, M.O. H+Al, P, K, Ca, Mg, Si, Fe2O3, Al2O3, SiO2 e textura do solo. Na mesma época, coletou-se a parte aérea de 10 plantas inteiras de cana-de-açúcar para determinação da produtividade e do silício acumulado nas plantas. As texturas dos solos... / Many extractants evaluated silicon availability in soil. In the United States, the acetic acid 0.5 mol L-1 is the most used. This Si extractant has already been used in Brazil, but it was recently replaced by the calcium chloride 0.01 mol L-1, the same used in Australia. The extractants generally depend on soil physical characteristics, mainly clay content, and thus may underestimate or overestimate Si levels in soil. There are no references in literature about silicon extractants that simulate the behavior of plant roots, like the anion exchange resin used to extract phosphate in soil. Therefore, the objective of this study was to evaluate chemical extractants that correlate Si available in soil with Si uptaken by sugar cane plants, cropped in sandy, sandy-loam and clayey soils. Eight Si extractants were tested with the aim to select the ones that most accurately evaluate different soil types in Brazil. The extractants were CaCl2 0.01 Mol L-1 (standard), CaCl2 0.01 Mol L-1 (modified), acetic acid 0.5 Mol L-1, KCl 0.01 Mol L-1, ion exchange resin, water, sodium acetate buffer pH 4.0 and HCl 0.01 Mol L-1. Samples were taken in Guaíra-SP, Brazil (Usina Guaíra) and Ariranha-SP, Brazil (Usina Colombo) between March and December of 2007 from areas cropped with sugar cane. At harvest, soil samples were taken from each experimental unit in the depths 0-0.20 m and 0.20-0.40 m to evaluate pH, organic matter (O.M.), H+Al, P, K, Ca, Mg, Si, Fe2O3, Al2O3, SiO2 and soil texture. Also, 10 plant shoots were harvested to determine yield and Si accumulation. Soil texture, iron oxide and aluminum oxide levels significantly influence on Si availability in soil. The acetic acid and buffer pH 4.0 extracted more silicon from soil, mainly in the clayey texture, that showed high levels of iron and aluminum oxides, highly correlating with Si accumulated in plant... (Complete abstract click electronic access below)

Orientadores: Maria Julia Marques, Humberto Santo Neto / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-10T12:44:34Z (GMT). No. of bitstreams: 1 Pertille_Adriana_D.pdf: 3109380 bytes, checksum: b99b5c31b8c138b7d403dd2de4f6629c (MD5) Previous issue date: 2008 / Resumo: A distrofia muscular de Duchenne (DMD) é caracterizada pela falta de distrofina, proteína estrutural do sarcolema que promove a sua estabilização. Em ausência de distrofina, ocorre aumento da permeabilidade ao cálcio e conseqüente mionecrose. Músculos como tibial anterior, sóleo, diafragma e esternomastóide sofrem ciclos de mionecrose e regeneração muscular. Por outro lado, os músculos extra-oculares (EO) não apresentam degeneração, sendo protegidos da falta da distrofina. A atividade das proteínas ligadas ao Ca++ pode ser um dos mecanismos envolvidos para explicar tal proteção. Nossos resultados revelaram aumento significativo do conteúdo da calmodulina (CaM) e quinase da cadeia leve de miosina (MLCK) no músculos EO mdx quando comparado ao controle. A quantidade da calpaína 1 dos músculos EO distróficos foi igual ao controle, confirmando a ausência do processo de degeneração muscular. Também verificamos se alterações no padrão de distribuição dos receptores de acetilcolina (ACh) e dos terminais nervosos, observadas em junções neuromusculares distróficas, são decorrentes da falta da distrofina ou da regeneração da fibra muscular. O padrão de distribuição dos receptores ACh nos músculos retos e oblíquos distróficos, não mostraram alteração quando comparados ao controle. No músculo retrator do bulbo mdx (parcialmente afetado pela distrofia) 56% dos receptores apresentaram padrão de distribuição alterado. Nossos resultados sugerem que a distrofina ou o complexo distrofina-glicoproteínas (CDG), não estão diretamente envolvidos na organização dos receptores nos músculos EO / Abstract: Duchenne muscular dystrophy (DMD) is characterized by the lack of dystrophin, structural protein that provides stability to the sarcolemma. In the absence of dystrophin, causes increased calcium permeability, leading to myonecrosis. Tibialis anterior, soleus, diaphragm and stermomastoid muscles undergoes myonecrosis and regeneration cycles. However, extraocular muscles (EO) do not show degeneration and are spared of the lack of dystrophin. We investigated whether this protection is related to an activated of calcium-binding proteins. Ours results showed significantly increased of calmodulin (CaM) and of the myosin light chain kinase (MLCK) in the mdx EO compared to control muscles. Calpain quantity in the dystrophic EO was equal of the control, confirmed the lack of the degeneration muscular processed. We also investigated whether changes in acetylcholine (Ach) receptor distribution at the neuromuscular junction and the nerve terminal, showed in the dystrophic neuromuscular junction, which could be correlated to the lack of dystrophy or the muscle fiber regeneration. Distribution ACh receptor in the dystrophic rectus and oblique exhibited no changes compared to control. In mdx retractor bulbi (partial affected by the dystrophy) 56% of the receptor exhibited distribution altered. Taken together, the results suggest the dystrophin or the dystrophin-glycoprotein complex does not influence the distribution of acetylcholine receptors at the neuromuscular junction of spared EO / Doutorado / Anatomia / Doutor em Biologia Celular e Estrutural

Orientador: Rafael Nobrega Stipp / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-25T14:55:16Z (GMT). No. of bitstreams: 1 Rodrigues_ItaloSartoCarvalho_D.pdf: 947131 bytes, checksum: 718f334861a919e4b10e20f1d03bdfd3 (MD5) Previous issue date: 2014 / Resumo: O biofilme é uma população biológica com um elevado grau de organização, onde os microrganismos presentes formam uma comunidade estruturada, coordenada e funcional. O estudo do comportamento dos biofilmes é fundamental para melhorar as formas de controle, especialmente durante infecções, tais como as doenças periodontais. No primeiro capítulo, foram avaliados os efeitos da aplicação tópica e frequente do digluconato de clorexidina (CLX) em diferentes concentrações na periodontite induzida por ligadura nos primeiros molares de ratos. As ligaduras receberam 10 µl de soluções de CLX à 0,2%, 2%, 10%, 20% ou diluente, de quatro em quatro dias, em um total de quatro aplicações. Após eutanásia, a quantidade de células bacterianas no biofilme formado sobre a ligadura foi estimada por cultura e por PCR quantitativo. A reabsorção óssea foi mensurada em altura e área por fotografia digital e em volume por microtomógrafo. Depois de quatro dias a partir da última aplicação da CLX, as reduções bacterianas mantidas pelos tratamentos com CLX atingiram até 10-6. O grupo que recebeu CLX a 20% teve, em média, logs bacterianos 3,3× menor (p<0.01, Kruskal-Wallis). Não houve diferença estatística entre os grupos em relação à reabsorção óssea por ambos os métodos testados (p>0.05, Kruskal-Wallis), embora 55% dos sítios apresentaram menor reabsorção óssea. No segundo capítulo, foi avaliada a influência de diversas substâncias na formação de biofilme por Prevotella intermedia. Os biofilmes foram formados em placas de 48 poços contendo tratamento de superfície prévio com DNA purificado, hemina, CaCO3, Ca(OH)2, CaCl2, soro, albumina, dextrana, metionina, glicose, glutamina, KCl, complexo vitamínico, cistina ou mucina. O biofilme formado foi corado e quantificado por espectrofotometria. A arquitetura do biofilme foi visualizada por microscopia confocal de fluorescência por varredura laser. O tratamento da superfície com CaCl2 a 1 mg/cm2 permitiu a formação do biofilme em quantidade de 0,3 OD490nm (p<0.01, ANOVA Dunnet), sendo esse valor 10× superior quando a superfície foi tratada com 2,5 mg/cm2 (p<0.01, ANOVA Dunnet). As demais substâncias tiveram pouco ou nenhum impacto sobre a formação do biofilme. A visualização por microscopia confocal revelou uma comunidade estruturada e com vitalidade em toda sua espessura. Conclusões: os dados indicam que a CLX concentrada diminui a carga bacteriana na região da periodontite induzida, que reflete em menor reabsorção óssea apenas em parte das amostras. O pré-revestimento da superfície de crescimento com cálcio promove a formação de biofilme por P. intermedia / Abstract: Biofilms are biological communities with a high degree of organization, in which micro-organisms form structured, coordinated and functional communities. These biological communities are embedded in a self-created extracellular matrix. Biofilm is also associated with a high level of antimicrobial tolerance of the associated organisms. Understanding biofilm behavior is crucial to develop ways for its control during infections, such as periodontal disease. In the first chapter, topical and frequent application of various concentrations of chlorhexidine digluconate (CLX) where evaluated. Periodontitis were induced by ligature on first molars. Then, ligatures were treated with 10 µl of chlorhexidine solutions at 0.2%, 2%, 10%, 20% or diluent, every four days in a total of four applications periods. After euthanasia, bacterial loads on ligatures were estimated by both culture and qPCR. Bone resorption height and area were measured by digital photography and its volume by microtomography. Treated sites had bacterial reductions up to 10-6 cells. Treatment with 20% CLX showed mean of 3.3× lower bacterial levels (p<0.01, Kruskal-Wallis). There was no statistical difference between groups regarding bone resorption (p>0.05, Kruskal-Wallis), although 55% of the treated sites had some lower bone resorption. In the second chapter, substances that may enhance biofilm formation by Prevotella intermedia were investigated. Wells of 48-well plates were coated with DNA, hemin, CaCO3, Ca(OH)2, CaCl2, serum, albumin, dextran, methionine, glucose, glutamine, KCl, vitamin complex, cystine or mucin. Biofilms were grown for 24 h, washed, stained and quantified by spectrophotometry. Biofilm architecture and its viability were visualized by Confocal Laser Scanning Microscopy. Surfaces treated with 1 mg/cm2 of CaCl2 enhanced biofilm amount by 0.3 OD490nm (p<0.01, ANOVA Dunnet), while 2.5 mg/cm2 yielded 10-fold more biofilm mass (p<0.01, ANOVA Dunnet). Other substances had modest or no impact in biofilm mass. Confocal microscopy images showed structured and alive biofilms with no dead areas. Conclusions: concentrated CLX reduces bacterial load, which reflects in lower bone resorption in few sites. Surfaces pre-coated with calcium chloride enhance P. intermedia biofilm formation / Doutorado / Microbiologia e Imunologia / Doutor em Biologia Buco-Dental

[pt] SO2 é conhecido com um grande contaminante ambiental e muitos países estabeleceram regras para o controle da sua emissão para a atmosfera. Como resultado a maioria das plantas fornecedoras de energia foram equipadas com instalações de dessulfurização de gases de combustão. Embora esta tecnologia seja bem sucedida no abate de SO2, ela gera uma grande quantidade de gesso FGD (flue gas desulfurization) como resíduo. Grandes esforços estão sendo feitos para aproveitar este resíduo (gesso FGD). No presente estudo o gesso FGD foi avaliado como aditivo retardador do tempo de pega substituindo o gesso natural na fabricação do cimento Portland (CP II E-32). Os resultados da caracterização físico-química e morfológica do gesso natural e de gesso FGD identificam um material de alta pureza, sulfato de cálcio di-hidratado para o gesso natural, e presença principalmente de bassanita (CaSO4.0,6H2O) e hannebachite (CaSO3.0,5H2O) com baixas concentrações de impurezas no gesso FGD. Baseado nos resultados, o gesso FGD é uma alternativa adequada para substituir o gesso natural. O tempo de pega mostrou cerca de uma hora de retardo em comparação com gesso natural e seu efeito sobre a resistência à compressão para as amostras de 3, 7 e 28 dias depende da composição das misturas, atingindo um valor máximo para a argamassa com 2,1 porcento de gesso FGD e 1,4 porcentode gesso natural. Também foi estimado o impacto ambiental do gesso FGD, examinando a liberação de seus constituintes inorgânicos seguindo a norma ABNT NBR 10004:2004 e classificando o resíduo como não perigoso e não inerte. / [en] The SO2 is well known as an important environmental contaminant and many countries have established rules to control its emission to the atmosphere and as result most of power supply plants were equipped with flue gas desulfurization systems. Although this technology is successful in the discharge of SO2, its generates a large amount of gypsum FGD (flue gas desulfurization) as a residue. Great efforts are being made to find destinations for this residue. In the present study, the FGD gypsum was evaluated as setting retarder to replace the natural gypsum in the production of Portland cement (CP II E-32). The results of physical-chemistry and morphological characterization of both products, natural and FGD gypsum showed a material of high purity, calcium sulfate dehydrate for natural gypsum, and the presence of bassanite (CaSO4.0,6H2O) and hannebachite (CaSO3.0,5H2O) with low concentrations of impurities for FGD gypsum. Based on the results, the FGD gypsum is a suitable alternative to replace natural gypsum. The setting time with FGD gypsum showed about 1 hour delay compared with natural gypsum and its effect on compressive strength, for samples of 3, 7 e 28 days, depend the composition of the mixtures, reaching the maximum value for the mixture of 1,4 weight percent natural gypsum and 2,1 weight percent FGD gypsum. The FGD gypsum environmental impact was evaluated by determining its potential in releasing inorganic constituents, following the standard ABNT NBR 10004:2004, and it was classified as a non-hazardous and non-inert.

[pt] Esta dissertação apresenta os resultados obtidos no processo de remediação de uma área contaminada por cromo hexavalente por meio da técnica de remediação química in situ (ISCR). A área de estudo localiza-se na cidade do Rio de Janeiro e foi ocupada por uma fábrica de vidros por cerca de quarenta anos e comprada para construção de condomínios residenciais. A área de estudo passou um processo de gerenciamento ambiental que contemplou diversos estudos ambientais para aquisição de dados e delimitar a contaminação, horizontal e verticalmente. O teste de bancada realizado com o reagente químico polissulfeto de cálcio demonstrou ser eficiente para reduzir as concentrações de cromo hexavalente em solo e água subterrânea. Com base nos dados adquiridos neste teste foi possível calcular a dose de injeção do polissulfeto de cálcio. Foram realizados setenta pontos de sondagem, pela técnica direct push, para injetar duzentos e cinquenta e dois mil e trinta litros de solução de polissulfeto de cálcio e água, sendo aproximadamente três mil e quinhentos litros por ponto de injeção. Os resultados após a injeção demonstraram que o polissulfeto de cálcio conseguiu remover o cromo hexavalente que estava adsorvido ao solo e reduziu a concentração de cromo hexavalente na água subterrânea entre quarenta e seis e sessenta e sete e noventa e nove e noventa e cinco por cento , após dezenove meses da injeção. Dessa forma, comprovou a eficiência deste reagente químico para remediação de áreas contaminadas por cromo hexavalente, assim como foi observado nos artigos técnicos de estudos de casos nos Estados Unidos e Europa. / [en] This dissertation presents the results obtained in the remediation process remediation of a contaminated area by hexavalent chromium applying the technology in situ chemical remediation (ISCR). The study area is located in the Rio de Janeiro city and was occupied by a glass factory for forty years and purchased for construction of residential condominiums. This dissertation presents the results obtained in the remediation process remediation of a contaminated area by hexavalent chromium applying the technology in situ chemical remediation (ISCR). The study area is located in the Rio de Janeiro city and was occupied by a glass factory for forty years and purchased for construction of residential condominiums. Chromium is an important metal for the industry and is used in various products and processes, such as electroplating, leather treatment, pulp, wood preservation, and refractory manufacturing. The trivalent chromium is essential from a nutritional point of view, non-toxic and poorly absorbed in the body, acting in the maintenance of some functions. Cr(III) is the most common being found and occurs naturally, since the element Cr(VI) can occur naturally, but in low concentrations, if the groundwater has geochemical conditions the Cr (III) can be oxidize to Cr (VI). The hexavalent chromium is the most dangerous valence state and, according to ATSDR (two thousand and twelve), have greater mobility in the groundwater, being carcinogenic by inhalation of high doses of soluble chromate salts. The mobility of hexavalent chromium is high in soil and groundwater because it is not adsorbed by the soil in that valence state, on the other hand when it is in trivalent form is strongly adsorbed by the soil, forming insoluble precipitates, having low mobility in soil and groundwater. The hexavalent chromium remediation by in situ chemical reduction using calcium polysulfide has been the subject of several field studies documented in the literature, both for soil and groundwater from the Chromite Ore Processing Residue (COPR) (Storch, et al., two thousand and two; Graham, et al., two thousand and six ; Charboneau, et al., two thousand and six ; Wazne, et al., two thousand seven a; Wazne, et al., two thousand seven b; Chrysochoou, et al., two thousand and ten ; Chrysochoou & Ting, two thousand and eleven ; Pakzadeh & Batista, two thousand and eleven ; Chrysochoou, et al., two thousand and twelve ). Calcium polysulfide is a fertilizer to soil and commercially available and has been used in some remediation studies cases for reducing hexavalent chromium in soil and groundwater. Being commercially available and used as fertilizer, it is a relatively cheap chemical reagent in comparison with other chemical compounds exclusively developed for this purpose. The stoichiometric demand and the chemical kinetics of the reduction of Cr (VI) by the calcium polysulfide in aqueous solution was studied by Graham et al. (two thousand and six) from the chromite ore processing residue (COPR). With this study it was reported that a molar ratio of a point sixty-six is required (close to the theoretical value of one point five) and a first-order kinetics with an initial concentration of twenty-six eight point mg/L and pH of the CPS solution around eleven point five, with the presence of oxygen. Thus, the hexavalent chromium is reduced to chromium hydroxide, slightly water soluble compound which is precipitated to the soil. The trivalent chromium has low solubility, toxicity, mobility, reactivity and is considered stable. There are various application techniques of chemical reagents in the underground environment, and choosing the most appropriate method for each area depends on the type of contaminant, geological environment, groundwater and surface interference, depth, thickness and size of the contaminated area. As described by Suthersan (mil novecentos ninety-six), the injection of chemical reagents has to achieve two objectives: (one) creating and maintaining an ideal redox environment and other parameters such as pH, presence or absence of dissolved oxygen, etc.; and (two) the delivery and distribution of the necessary reagents for a homogeneous way throughout the injection area, both horizontally and vertically. Thus, it is essential that the conceptual model of the study area is very detailed, so there is no doubt in the choice of chemical reagent application methodology. Although there are numerous laboratory studies on hexavalent chromium remediation using calcium polysulfide, there are few reports in the literature on the field application, especially case studies in Brazil, therefore, this case study becomes a demonstration applying calcium polysulfide as a remediation technique for hexavalent chrome, with geochemical data, which are important for monitoring chemical reduction. This case study shows the effectiveness, dosage and concentration of the study area, and may apply to other hexavalent chromium remediation projects. Materials and Methods A former glass factory (the Site ) operated in the North Zone of Rio de Janeiro / RJ, Brazil from the mid-thousand nine hundred and fifty s to two thousand and five. A portion of the facility was used to store raw material to produce glass, including arsenic oxide, and another portion of the Site was used to conduct industrial plating using hexavalent chromium (Cr(VI)) in the glass molds. In two thousand and nine, the Site was purchased for mixed use redevelopment, demanding an environmental assessment and subsequent remediation. Between two thousand and nine and two thousand and twelve several phases of site investigation was conducted. The results of the investigation indicated that Cr(VI) was present in soil at concentrations up to approximately twenty one mg/kg and in groundwater at concentrations up to approximately thirty mg/L. These concentrations exceeded regulatory criteria of three hundred mg/Kg for soil and zero point zero five mg/L for groundwater. A phased remedial approach was developed consisting of the following: (a) excavation and off-site disposal of two and four hundred ton of Cr(VI) impacted soil from the source area, performed in the unsaturated and saturated zone soils in the Cr(VI) source area; (b) post-excavation monitoring of the groundwater conditions; and (c) groundwater treatment following the excavation program. Hexavalent chromium concentrations in groundwater decreased significantly following the excavation, however, additional reduction of concentrations of Cr(VI) contaminant in groundwater was required. Then was designed and implemented a set of bench-scale treatability tests in order to evaluate groundwater remediation alternatives. Several proprietary and non-proprietary reductants for co-treatment of Cr(VI) were evaluated. Calcium polysulfide were selected to treat Cr(VI). To reduce residual Cr(VI) concentrations in the groundwater plume located downgradient of the former excavated source area, dois e seven hundred cubic meters were targeted for active treatment. The groundwater remediation approach consisted of the injection of thirty liters of CPS (twenty nine percent) diluted in two hundred and twenty liters of water, yielding a total of two hundred and fifty liters of solution injected using direct push technology into seventy two locations. Groundwater Monitoring As part of chemical reagent injection stage was performed the baseline monitoring with collection of soil and groundwater samples. The soil sampling was performed by direct push technique using PVC liner with two inches in diameter, to analyze the total and hexavalent chromium concentrations. Six months after the injection were installed sixteen monitoring wells, eight shallow wells (five meters) and eight deep wells (nine meters) spread upstream, side, middle and downstream of the injection area. Groundwater geochemical parameters (i.e., temperature, total solids dissolved, specific conductance, pH, oxidation-reduction potential, and temperature) were measured at the time groundwater samples were collected. Groundwater samples were collected and analyzed for total and dissolved chromium, hexavalent chromium, iron, arsenic, manganese, calcium, sulfate, and sulfide. Samples were field-filtered with disposable zero point forty-five μm polyethylene filter capsules prior to collecting samples for dissolved metals. Results and Discussion Dose calculations for the reduction of hexavalent chromium have been performed with the data obtained in the bench-scale treatability test and resulted in a stoichiometric demand of four mlCPS/kg soil to the treatment of the study area. Therefore thirty liters of solution was used containing twenty-nine percent calcium polysulfide and approximately two hundred and twenty two liters to perform their mixture, totaling two hundred and fifty-two thousand and thirty liters of solution. For solution injection were performed seventy two soil borings with eight point five meters deep, and the product was injected range between two point five and eightpoint five meters. The depth of injection was from two point five mbgl covered any change in water level due to seasonal variation. In each soil boring was injected chemical reagent solution comprised four hundred and seventeen liters of calcium polysulfide diluted in tree and eighty-three liters of water for a total volume of tree and a half liters of solution injected per point. The comparative analysis results of the third monitoring campaign ( eighteen months post-injection) with the baseline campaign (september/two thousand and twelve) indicated reduction of hexavalent chromium concentrations between forty-six point sixty-seven and ninety-nine and ninety-five percent. Regarding the second monitoring campaign (twelve months post-injection), the hexavalent chromium concentrations reduced between twenty-three point ninety-nine and ninety nine point seventy-nine percent in five of the fifteen monitoring wells that were sampled. In three of the fifteen monitoring wells the hexavalent chromium concentrations remained below the quantitation limit used by the analytical laboratory method. There was no increase in hexavalent chromium concentration, compared the results of the third and second monitoring campaign. The evaluation of the Eh and pH values measured in the monitoring campaigns showed that the pH value was in the acidic range (about four ) and after removal of contaminated soil with hexavalent chromium pH raised to between five and six, after the chemical reagent injection pH increased to the basic range (above seven point five). In the second and third campaign the pH reduced to acid range (below six point five), which can be regarded as the pH value of the area background. The Eh has inversely proportional behavior, increasing between the first and third campaign, and in the third campaign the measured values are in the ranges considered as moderately reducing (hundred to four hundred mV) and oxidizer (> four hundred mV). The pH variation also showed a relationship between increased concentrations of calcium, iron, manganese and sulfate (in some monitoring wells). There were also reductions in hexavalent chromium concentrations in monitoring wells. Conclusion This case study indicates that the use of different remediation techniques when applied together (excavation and chemical reduction), reducing the time required for remediation of a contaminated site without impacting the final cost of remediation. The chemical reduction of hexavalent chromium using calcium polysulfide was effective to reduce the concentration to less than the quantification limit of the analytical method used. Therefore, as presented it is necessary to carry out several studies to detail the hexavalent chromium concentration in the site, as well as understand the geochemistry of groundwater and performing bench-scale tests to evaluate the effectiveness of the chemical reagent in the site study hydrogeological environment and calculate the required dose. The treatability test with calcium polysulfide demonstrated the feasibility of using this chemical reagent by In Situ Chemical Reduction (ISCR) to reduce the hexavalent chrome concentration in soil and groundwater. The test resulted in a stoichiometric demand of four mlCPS /kg soil to the treatment of the study area. Soil samples collected six months after injection showed that the calcium polysulfide could desorb hexavalent chromium from the soil, since, contaminant concentrations were not detected in the samples. neteen months after the injection of the chemical reagent the groundwater concentrations of hexavalent chromium reduced from forty-six point sixty-seven to ninety-nine and ninety-five percent in relation to baseline campaign. And, of the fifteen monitoring wells in just three wells hexavalent chromium concentrations were detected. This demonstrates the effectiveness of using calcium polysulfide to remediate hexavalent chromium in soil and groundwater, confirming the studies by Storch et al. (two thousand and two), Graham et al (two thousand and six), Charboneau et al. ( two thousand and six), Wazne et al. (two thousand and seven a), Wazne et al. (two thousand and seven b), Chrysochoou et al. (two thousand and ten), Chrysochoou & Ting (two thousand and eleven), Pakzadeh & Batista (two thousand and eleven), Chrysochoou et al (2012) in several areas in United States and Europe.

[pt] Durante a exploração e produção de petróleo, dificuldades operacionais precisam ser superadas na injeção de CO2 para aumento da produção. Na presença de água, o CO2 reage e forma o H2CO3, que pode vir a corroer o aço carbono presente nos dutos flexíveis. Diversos fatores influenciam no processo corrosivo, entre eles a pressão parcial de CO2, a temperatura, pH do meio e a relação volume de solução/área metálica exposta (V/A). Desta forma, o objetivo deste trabalho foi avaliar a composição e propriedades mecânicas dos produtos de corrosão depositados sobre a superfície do aço carbono 1080 imersos em água do mar sintética, a temperatura de 40 graus C, durante 15 e 121 dias. Para avaliar a influência da pressão parcial de CO2, os ensaios foram realizados a 1, 10 e 20 bar de CO2, já para avaliar a influência da relação V/A, os ensaios foram realizados a 1 mL.cm-2 e 20 mL.cm-2 . As taxas de corrosão foram determinadas utilizando o método gravimétrico, as caracterizações dos produtos de corrosão foram realizadas por Microscopia Óptica (MO), Microscopia Eletrônica de Varredura (MEV), Espectroscopia de Energia Dispersiva (EDS) e Dispersão de Raios X (DRX). Adicionalmente, foi utilizada a Nanoindentação para determinar as propriedades mecânicas do filme formado. A partir da MO, foi identificado a formação de dois filmes em quase todas as condições estudadas. Ao avaliar a influência da pressão, não foram observadas variações significativas na taxa de corrosão. Já os resultados obtidos para avaliar o efeito da relação V/A, foi possível concluir que o ambiente confinado reduz significativamente a taxa de corrosão. Ao avaliar as propriedades mecânicas dos filmes, foi possível observar que em todos os casos, a dureza e o módulo de elasticidade são menores no filme interno quando comparados ao filme externo. Isso pode estar relacionado a formação de uma camada externa mais compacta, constituída predominantes por pequenos grãos de FeCO3, conforme os resultados obtidos através do MEV e DRX / [en] During oil exploration and production, operational difficulties need to be overcome in CO2 injection to increase production. In the presence of water, CO2 reacts and forms H2CO3, which can corrode the carbon steel present in flexible pipes. Several factors influence the corrosive process, including the partial pressure of CO2, the temperature, pH of the medium and the volume of solution/exposed metallic area (V/A) ratio. Thus, the objective of this work was to evaluate the composition and mechanical properties of the corrosion products deposited on the surface of carbon steel 1080 immersed in synthetic sea water, at a temperature of 40 C degrees, for 15 and 121 days. To evaluate the influence of the partial pressure of CO2, the tests were carried out at 1, 10 and 20 bar of CO2, and to evaluate the influence of the V/A ratio, the tests were carried out at 1 mL.cm-2 and 20 mL. cm-2 . Corrosion rates were determined using the gravimetric method, characterizations of corrosion products were performed by Optical Microscopy (OM), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDS) and X-Ray Scattering (XRD). Additionally, Nanoindentation was used to determine the mechanical properties of the formed film. From the OM, the formation of two films was identified in almost all conditions studied. When evaluating the influence of pressure, no significant variations in the corrosion rate were observed. As for the results obtained to evaluate the effect of the V/A ratio, it was possible to conclude that the confined environment significantly reduces the corrosion rate. When evaluating the mechanical properties of the films, it was possible to observe that in all cases, the hardness and the elastic modulus are lower in the inner film when compared to the outer film. This may be related to the formation of a more compact outer layer, consisting predominantly of small FeCO3 grains, according to the results obtained through SEM and XRD.

[ES] En el proceso de producción de silicatos de calcio implantando en Promat (Tisselt, Bélgica), la xonotlita y la tobermorita como fases minerales mayoritarias, se obtienen al hacer reaccionar una mezcla de óxido de calcio y sílice cristalina en medio acuoso con una relación CaO/SiO2 cercana a 1, y en condiciones hidrotermales, a una temperatura de 200°C y a una presión de vapor de 17 bar. En este proyecto de doctorado industrial, se pretende alcanzar tres objetivos principales: 1. Desarrollar una nueva tecnología para la obtención de silicatos de calcio hidratados, mediante la síntesis inicial de gel C-S-H para controlar la densidad del producto final. Éste es un proceso que lo emplean algunos competidores de Promat y que denominamos en esta tesis como tecnología 'Gel Tank'. También se pretende llevar a cabo un profundo estudio de los parámetros clave que influyen en el proceso. Además, se pretende investigar la viabilidad de producir silicatos de calcio hidratados con diferentes densidades y comparar las propiedades de éstos con los obtenidos mediante tecnologías existentes. Con el empleo de esta nueva tecnología, la idea es utilizar menor cantidad de agua que en los procesos convencionales, y con ello reducir el gasto energético, minimizando el impacto medioambiental. 2. Ampliar el conocimiento de la tecnología basada en tratamiento hidrotermal mediante agitación e investigar la posibilidad de mejorar el carácter endotérmico de los materiales obtenidos a través de esta tecnología. 3. Desarrollar una nueva generación de productos libres de contenido en cuarzo residual (< 0,1% en peso) mediante el uso de la denominada tecnología "double autoclaving". En la primera parte de esta tesis, el estudio de investigación de la tecnología Gel Tank a escala de laboratorio ha demostrado que se pueden obtener silicatos de calcio hidratados para un rango de densidades que varían desde 280 Kg/m3 hasta 700 Kg/m3, utilizando cantidades óptimas de gel C-S-H sintetizado en condiciones específicas. Y se pueden obtener productos de buena calidad con menor relación agua/sólido (y por lo tanto menor dependencia energética) que en el caso de las tecnologías existentes. En la segunda parte de esta tesis, se han investigado los diferentes mecanismos de reacción entre distintas fuentes de sílice utilizando diferentes técnicas analíticas clásicas para caracterizar los productos intermedios y otras técnicas más avanzadas. Esto permitió explicar parcialmente los mecanismos de reacción hidrotermal para la síntesis de cristales de xonotlita y tobermorita. Por otro lado, Se han probado varios aditivos inorgánicos de carácter endotérmico en la matriz de productos elaborados en Promat a partir de partículas de xonotlita en su mayoría. Y con ello, se han propuesto otras alternativas para la protección al fuego y aislamiento térmico en diferentes aplicaciones (160ºC - temperatura de descomposición de endotermo para emplear en tabiques o compartimentos, 380ºC - temperatura de descomposición de endotermo para proteger estructuras de hormigón y 500ºC - temperatura de descomposición de endotermo en el caso de protección de estructuras metálicas de acero). Y en la última parte, se ha buscado una alternativa al producto de referencia que no contenga cuarzo residual en su matriz empleando la tecnología basada en doble tratamiento hidrotermal. Los productos obtenidos han sido desarrollados tras aplicar variaciones en la formulación estándar, y han dado lugar a propiedades mecánicas y térmicas similares a los productos existentes que contienen cuarzo residual. Estos nuevos productos presentan contenidos en cuarzo residual por debajo del 0,1% en peso. / [CAT] En el procés de producció de silicats de calci implantant a Promat (Tisselt, Bèlgica), la xonotlita i la tobermorita com a fases minerals majoritàries, s'obtenen en fer reaccionar una barreja d'òxid de calci i sílice cristal·lina en medi aquós amb una relació CaO/ SiO2 propera a 1, i en condicions hidrotermals, a una temperatura de 200°C ia una pressió de vapor de 17 bar. En aquest projecte de doctorat industrial, es pretén assolir tres objectius principals: 1. Desenvolupar una nova tecnologia per obtenir silicats de calci hidratats, mitjançant la síntesi inicial de gel C-S-H per controlar la densitat del producte final. Aquest és un procés que el fan servir alguns competidors de Promat i que anomenem en aquesta tesi com a tecnologia 'Gel Tank'. També es pretén dur a terme un estudi profund dels paràmetres clau que influeixen en el procés. A més, es pretén investigar la viabilitat de produir silicats de calci hidratats amb diferents densitats i comparar-ne les propietats amb els obtinguts mitjançant tecnologies existents. Amb l'ús d'aquesta nova tecnologia, la idea és utilitzar menor quantitat d'aigua que en els processos convencionals, i reduir la despesa energètica i minimitzar l'impacte mediambiental. 2. Ampliar el coneixement de la tecnologia basada en tractament hidrotermal mitjançant agitació i investigar la possibilitat de millorar el caràcter endotèrmic dels materials obtinguts mitjançant aquesta tecnologia. 3. Desenvolupar una nova generació de productes lliures de contingut en quars residual (< 0,1% en pes) mitjançant l'ús de l'anomenada tecnologia "double autoclaving". A la primera part d'aquesta tesi, l'estudi de recerca de la tecnologia Gel Tank a escala de laboratori ha demostrat que es poden obtenir silicats de calci hidratats per a un rang de densitats que varien des de 280 kg/m3 fins a 700 kg/m3, utilitzant quantitats òptimes de gel C-S-H sintetitzat en condicions específiques. I es poden obtenir productes de bona qualitat amb menor relació aigua/sòlid (i per tant menor dependència energètica) que en el cas de les tecnologies existents. A la segona part d'aquesta tesi, s'han investigat els diferents mecanismes de reacció entre fonts de sílice diferents utilitzant diferents tècniques analítiques clàssiques per caracteritzar els productes intermedis i altres tècniques més avançades. Això va permetre explicar parcialment els mecanismes de reacció hidrotermal per a la síntesi de vidres de xonotlita i tobermorita. D'altra banda, S'han provat diversos additius inorgànics de caràcter endotèrmic a la matriu de productes elaborats a Promat a partir de partícules de xonotlita majoritàriament. I amb això, s'han proposat altres alternatives per a la protecció al foc i aïllament tèrmic en diferents aplicacions (160ºC - temperatura de descomposició d'endoterm per emprar en envans o compartiments, 380ºC - temperatura de descomposició d'endoterm per protegir estructures de formigó i 500ºC - temperatura de descomposició d'endoterm en cas de protecció d'estructures metàl·liques d'acer). I a l'última part, s'ha buscat una alternativa al producte de referència que no contingui quars residual a la seva matriu emprant la tecnologia basada en doble tractament hidrotermal. Els productes obtinguts han estat desenvolupats després d'aplicar variacions a la formulació estàndard, i han donat lloc a propietats mecàniques i tèrmiques similars als productes existents que contenen quars residual. Aquests nous productes presenten continguts en quars residual per sota del 0,1% en pes. / [EN] In the calcium silicate production process in Promat (Tisselt, Belgium), xonotlite and tobermorite as main mineral phases, are obtained by reacting a mixture of calcium oxide and crystalline silica in an aqueous medium with a CaO/ SiO2 close to 1, and under hydrothermal conditions, at a temperature of 200°C and a vapor pressure of 17 bar. In this industrial doctorate project, it is intended to achieve three main objectives: 1. Develop a new technology to obtain hydrated calcium silicates, through the initial synthesis of C-S-H gel to control the density of the final product. This is a process that is used by some of Promat's competitors and that we refer to in this thesis as 'Gel Tank' technology. It is also intended to carry out an in-depth study of the key parameters that influence the process. In addition, it is intended to investigate the feasibility of producing hydrated calcium silicates with different densities and compare their properties with those obtained by existing technologies. With the use of this new technology, the idea is to use less water than in conventional processes, and thereby reduce energy expenditure, minimizing the environmental impact. 2. Expand the knowledge of the technology based on hydrothermal treatment by means of agitation and investigate the possibility of improving the endothermic character of the materials obtained through this technology. 3. Develop a new generation of products free of residual quartz content (<0.1% by weight) through the use of the so-called "double autoclaving" technology. In the first part of this thesis, the research study of Gel Tank technology at a laboratory scale has shown that hydrated calcium silicates can be obtained for a range of densities that vary from 280 Kg/m3 to 700 Kg/m3, using Optimal amounts of C-S-H gel synthesized under specific conditions. And good quality products can be obtained with a lower water/solid ratio (and therefore less energy dependence) than in the case of existing technologies. In the second part of this thesis, the different reaction mechanisms between different sources of silica have been investigated using different classical analytical techniques to characterize the intermediate products and other more advanced techniques. This allowed to partially explain the hydrothermal reaction mechanisms for the synthesis of xonotlite and tobermorite crystals. On the other hand, several inorganic additives of an endothermic nature have been tested in the matrix of products made in Promat, mostly from xonotlite particles. And with this, other alternatives have been proposed for fire protection and thermal insulation in different applications (160ºC - endotherm decomposition temperature to be used in partitions or compartments, 380ºC - endotherm decomposition temperature to protect concrete structures and 500ºC - endotherm decomposition temperature in the case of protection of metallic steel structures). And in the last part, an alternative to the reference product that does not contain residual quartz in its matrix has been sought, using technology based on double hydrothermal treatment. The products obtained have been developed after applying variations in the standard formulation, and have given rise to mechanical and thermal properties similar to existing products that contain residual quartz. These new products have residual quartz contents below 0.1% by weight. / Martí Montava, F. (2023). Development of Hydrated Calcium Silicates by Hydrothermal Treatments [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/192513

Questa tesi tratta, a partire da una prospettiva antropologica, delle relazioni tra calcio e religione in Brasile. In particolare, si propone come obiettivo quello di comprendere una pratica dei calciatori brasiliani chiamata “fechamento”. Questo termine indica l’insieme di espressioni, corporali e verbali che i calciatori mettono in atto sistematicamente prima delle competizioni, e che si distingue da pratiche simili per la recitazione collettiva della preghiera del Padre Nostro. Da un punto di vista simbolico, l’ermeneutica del “fechamento” ci permette di raggiungere una comprensione che trascende l’oggetto in sé, rivelando una particolare visione del mondo (Geertz, 1989). A partire da una etnografia realizzata con i giocatori del settore giovanile dello Sport Club Internacional de Porto Alegre (RS, Brasile), integrata con il vissuto del ricercatore durante la sua lunga permanenza in Brasile, la tesi cerca di rivelare il significato profondo di questa pratica polimorfica che, per le sue caratteristiche intrinseche, si configura come un “bricolage religioso”, costituita da “pezzi” di vari elementi di credenze differenti, formando un mosaico (Bastide,1953-1970) di cui la matrice cattolico-cristiana costituisce il piano di fondo A partire da questa prospettiva, è possibile relativizzare l’impatto del neopentecostalismo nel calcio brasiliano (Rial, 2012; 2013), tenendo in considerazione la sua caratteristica “religiofaga” (Oro, 2015) o “antropofaga” (Almeida, 2003), ossia la propensione ad appropriarsi, risignificare e risimbolizzare elementi di credenze prese da altre religioni. Il caso del “fechamento”, tra i calciatori brasiliani, sembra essere emblematico di questo processo che, invece di rivelare la sua “faccia” neopentecostale, rafforza ancor di più il suo già alto grado di “bricolage religioso”. Dunque il “fechamento” come prodotto “sincretico” non sarebbe al servizio di una religione (neopentecostalismo) ma di tutte. Questo spiegherebbe il suo successo indipendentemente dalle appartenenze religiose dei giocatori. / Cette thèse traite, à partir d’une perspective anthropologique, des relations entre le football et la religion au Brésil. Plus précisément, celle-ci a pour objectif de comprendre une pratique des footballeurs brésiliens appelée “fechamento”. Ce terme désigne l’ensemble des expressions, corporelles et verbales, que les joueurs actionnent systématiquement avant les compétitions, et qui se distingue d’autres pratiques semblables par la récitation collective de la prière du Notre Père. D’un point de vue symbolique, l’herméneutique du « fechamento » permet d’atteindre une compréhension qui transcende l’objet en soi, révélant une particulière vision du monde (Geertz, 1989). A partir d’une ethnographie réalisée auprès des jeunes footballeurs du Sport Club Internacional de Porto Alegre (RS, Brésil) et complétée par le vécu de l’enquêteur pendant son long séjour au Brésil, la thèse essaie de comprendre le sens profond de cette pratique polymorphe, laquelle, par ses caractéristiques intrinsèques , se configure come un « bricolage religieux » , composé de morceaux de éléments variés provenant de croyances différentes, formant une mosaïque (Bastide, 1953-1970) dont la matrice catholico - chrétienne est la toile de fond A partir de cette perspective, nous pouvons relativiser l’impact du néopentecôtisme dans le football brésilien (Rial, 2012 ; 2013), tenant compte de sa caractéristique « religiophagique » (Oro, 2015) ou « anthropophagique » (Almeida, 2003), c’est-à-dire de sa propension à s’approprier, re-signifier et re-symboliser des éléments d’autres religions. Le cas du « fechamento », chez les footballeurs brésiliens, semble être emblématique de ce procès qui, au lieu de révéler sa « face » néopentecôtiste, renforce encore plus son degré déjà élevé de bricolage religieux. Donc le « fechamento » en tant que produit « syncrétique » ne serait au service d’une religion (néopentecôtisme) mais de toutes. Ceci expliquerait son succès indépendamment des appartenances religieuses des footballeurs. / Esta tese trata, a partir de uma perspectiva antropológica, das relações entre futebol e religião no Brasil. Mais especificamente, tem como objetivo compreender uma prática dos futebolistas brasileiros chamada “fechamento”. Este termo refere-se a um conjunto de expressões, corporais e verbais, que os futebolistas acionam sistematicamente antes as competições e que se distingue de práticas semelhantes pela recitação coletiva da reza do Pai Nosso. De um ponto de vista simbólico, a hermenêutica do “fechamento” permite alcançar uma compreensão que transcende o objeto em si, sendo reveladora de uma determinada visão de mundo (Geertz, 1989). A partir de uma etnografia realizada com os jogadores das categorias de base do Sport Club Internacional de Porto Alegre (RS, Brasil), complementada com o retrospecto do pesquisador durante a sua longa estada no Brasil, a tese procura revelar o significado profundo desta prática polimórfica que, pelas suas características intrínsecas, se configura como uma “bricolagem religiosa”, sendo constituída por pedaços de vários elementos de crenças diferentes, formando um mosaico (Bastide, 1953-70) onde a matriz católica-cristã constitui o pano de fundo A partir desta perspectiva é possível relativizar o impacto do neopentecostalismo no futebol brasileiro (Rial, 2012; 2013), tendo em consideração a sua característica “religiofágica” (Oro, 2015) ou “antropofágica” (Almeida, 2003), isto é, a propensão de se apropriar, ressignificar e ressimbolizar elementos de crenças tomadas de outras religiões. O caso do “fechamento”, entre os futebolistas brasileiros, parece ser emblemático deste processo que, em vez de revelar a sua “face” neopentecostal, reforça ainda mais o seu já alto grau de “bricolagem religiosa”. Portanto o “fechamento”, enquanto produto “sincrético”, não estaria ao serviço de apenas uma religião (neopentecostalismo), mas de todas. Isto explicaria o seu sucesso independentemente dos pertencimentos religiosos dos futebolistas / Starting from an anthropological perspective, this thesis deals with the relationship between football and religion in Brazil. In particular, it aims to understand a practice adopted by Brazilian footballers, which is called ‘fechamento’. This term refers to the set of verbal and bodily expressions that footballers systematically display before competitions, which differs from similar practices used for the collective recitation of the Lord’s Prayer. From a symbolic point of view, hermeneutics of ‘fechamento’ allows us to acquire an understanding that transcends the object per se, thus revealing a particular world view (Geertz, 1989). Starting from an ethnography carried out with the players of the youth team of Sport Club Internacional de Porto Alegre, Brazil and integrated with the experience gained by the researcher during his long stay in Brazil, this thesis aims to reveal the deep meaning of this polymorphic practice which, because of its intrinsic features, appears to be a ‘religious bricolage’, made up of ‘pieces’ of various elements of different beliefs, thus forming a ‘mosaic’ (Bastide, 1953-1970), for which the Catholic-Christian root represents the backdrop Starting from this perspective, it becomes possible to relativise the impact of Neo- Pentecostalism on Brazilian football (Rial, 2012; 2013), by taking into consideration its “religiophagous” (Oro, 2015) or “anthropophagous” (Almeida, 2003) feature, i.e. the tendency to incorporate, redefine and re-symbolise elements of beliefs taken from other religions. The case of ‘fechamento’, among Brazilian footballers, seems to be emblematic of this process which, instead of revealing its Neo-Pentecostal ‘face’, strengthens even more the already high degree of ‘religious bricolage’. Therefore ‘fechamento’ as a ‘syncretic’ product would no longer be based on one religion (Neo-Pentecostalism) but on all. This would explain its success regardless of the religious orientation of players.