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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
411

Analýza současného stavu, revize a testování nových postupů tvorby skladebných prvků ÚSES vybraných  katastrálních území Novohradska. / Analysis of current condition, revision and testing of new procedures during the formation of structural elements TSES selected cadastral areas Novohradsko.

SÍČOVÁ, Petra January 2010 (has links)
Territorial system of ecological stability is artificial, interlinked set of natural and altered similar to natural ecosystems that sustain the natural balance. In selected area Novohradsko was approved plan TSES already a decade ago. This study revises the area according to the standard method that is based on biological evaluation. During updating natural segment of area are being tested and used the new procedures, which include the functional aspects of the landscape. Specifically, they are based on physico-chemical evaluation. Data from the mapping of the defined area were processed and analyzed using GIS tools. The method of the functional aspects of landscapes can usefully complement the standard methodology with the objective identification of optimal functional and dysfunctional areas, which are an alternative to the segments of the skeleton of ecological stability.
412

Propriedades eletrônicas e magnéticas de moléculas solvatadas / Electronic and magnetic properties of solvated molecules

Rodrigo do Monte Gester 28 September 2012 (has links)
Ressonância magnética nuclear é particularmente útil na caracterização de síntese molecular. Quase todos os compostos moleculares de interesse contêm átomos de nitrogênio e oxigênio em sua estrutura. Como esses elementos químicos costumam desempenhar funções estratégicas em reações e interações intra e intermoleculares, seus espectros NMR têm particular interesse. Com foco na blindagem magnética nuclear e no acoplamento entre spins nucleares, investigamos a dependência dessas constantes magnéticas com relação ao meio. A polarização eletrônica e relaxação geométrica do soluto, devido à presença do solvente, foram sistematicamente consideradas utilizando um tratamento sequencial QM/MM. Nossas observações gerais mostram que efeitos de relaxação de geometria mediados pelo meio têm pouca influência sobre o mecanismo da blindagem magnética nuclear, pelo menos quanto aos sistemas aqui investigados. Em contrapartida, os efeitos da polarização eletrônica são cruciais sobre essa propriedade molecular. Para o nitrogênio em piridina, amônia e formamida, por exemplo, as contribuições isoladas provenientes da relaxação geométrica são da ordem de 1,2 ppm. Note-se que este efeito é muito pequeno se considerarmos que com frequência são observados desvios gás-líquido da ordem de -26 ppm para o nitrogênio. Sobre o oxigênio, esses efeitos podem chegar até 100 ppm. Assim, é crucial entender as origens desses efeitos se desejamos utilizar corretamente espectroscopia RMN em caracterização molecular. Relevantes contribuições para a blindagem magnética têm origens em interações específicas entre soluto e solvente, como ligações de hidrogênio, as quais apenas podem ser isoladas e quantificadas através de modelagem molecular. Sistematicamente constatamos que a blindagem magnética é drasticamente afetada pelo caráter doador ou aceitador do sítio atômico envolvido em ligações de hidrogênio. Com respeito ao nitrogênio, nossos resultados indicam que o comportamento aceitador de hidrogênio de um elemento é responsável por um desvio gás-líquido positivo, enquanto que o caráter doador causa um desvio negativo. Nossas investigações também mostram que a blindagem magnética nuclear é independente com relação à hibridização do nitrogênio e oxigênio, indicando que as contribuições principais têm origens em interações específicas soluto-solvente, as quais devem ser corretamente modeladas. Investigamos sistematicamente os efeitos do solvente sobre o acoplamento indireto entre spins nucleares em amônia líquida. Embora a polarização do soluto seja realmente importante, para essa propriedade há outras contribuições fundamentais. Sem considerar efeitos de geometria, calculamos o acoplamento ANTPOT. 1 J(N-H) como -67,8 Hz. Após incluir esses efeitos, conseguimos uma descrição teórica mais apurada, obtendo um acoplamento de -63,9 Hz. Esses resultados mostram que efeitos de relaxação geométrica mediado pelo meio têm grande influência sobre o acoplamento indireto entre spins nucleares. / Nuclear magnetic resonance is helpful on molecular characterization. Most organic molecular compounds of interest contain nitrogen or oxygen atoms which play strategic functions in chemical reactions and molecular interactions. The NMR technique provides local atomic scale information on molecular properties, thus the study of nuclear magnetic properties of these elements in molecules is of particular interest. Focusing on nuclear magnetic shielding and spin-spin coupling constants we investigated the dependence of these magnetic constants with respect to the medium. Electronic polarization and geometry relaxation effects due to solvent were systematically studied. Our general findings indicate that geometry contributions are negligible in understanding the variation of shielding constants of the investigated systems, but polarization effects are crucial for this molecular property. On nitrogen in pyridine, ammonia and formamide, for instance, isolated contributions from geometry relaxation to shielding constants are around 1,2 ppm. Nitrogen shielding constants are very sensitive to the medium, where solvent effects around -26 ppm are often observed. On oxygen-17 magnetic shielding, the solvent effects can easily reach 100 ppm. It is crucial to understand the origins of these effects if one desires to correctly use NMR spectroscopy for molecular characterization. Our investigations also show that magnetic shielding constants are totally independent of the nitrogen or oxygen hybridization, which indicated that the main contributions arise from solute-solvent interactions. Relevant contributions to shielding constants come from specific solute-solvent interactions like hydrogen-bonds, which can only be quantified by explicit molecular modeling, and we observed that this property has a very strong dependence on the donor or acceptor character of the atomic site involved in hydrogen-bonding interactions. On nitrogen, the acceptor behavior is responsible by the positive gas-liquid shift in shielding constants, while the donor character causes positive shift. We systematically investigated the solvent effects on indirect spin-spin coupling constants of liquid ammonia. Solute polarization is very important, but there are other fundamental contributions to this property. Without including geometry effects we calculated the 1J (N-H) coupling to be -67,8 Hz. After accounting for the solute geometry relaxation we improved the theoretical prediction obtaining the coupling constant value of -63,9 Hz. These results show that geometry relaxation has drastic influence on indirect spin-spin coupling constants.
413

Estabilidade da polpa de caju congelada obtida com o uso de conservantes, pasteurizada e concentrada / Physical and chemical stability of frozen cashew pulp obtained with the use of preservatives, pasteurized and concentrated

Virlane Kelly Lima da Silva 03 January 2013 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / O caju destaca-se dentre as espÃcies frutÃferas nativas do Nordeste, por possuir elevada potencialidade para o consumo in natura e processamento industrial. A polpa e o suco sÃo importantes componentes da dieta humana por serem considerados uma fonte natural de carboidratos, carotenoides, vitaminas e compostos fenÃlicos, substÃncias com alto potencial antioxidante, e tÃm despertado o interesse de diferentes grupos de pesquisa. Este trabalho teve como objetivo estudar a estabilidade da polpa de caju com conservantes, pasteurizada e concentrada congelada durante 12 meses de armazenamento, atravÃs de determinaÃÃes quÃmicas, fÃsico-quÃmicas e microbiolÃgicas e a elaboraÃÃo de nÃctar e suco tropical adoÃado, estudando a estabilidade sensorial dos mesmos durante 360 dias de armazenamento da polpa. As polpas nÃo apresentaram interaÃÃo significativa para pH, sÃlidos solÃveis, acidez titulÃvel e coordenada de cor a. O pH e os sÃlidos solÃveis variaram com o tempo mas mantiveram-se dentro dos padrÃes da legislaÃÃo. A acidez nÃo variou com o armazenamento. A coordenada de cor a* ajustaram ao modelo cÃbico. O Ãcido ascÃrbico variou de 190,65 a 308,45mg/100g na polpa com conservantes, 170,95 a 299,70 mg/100g na polpa pasteurizada e de 514,68 a 865,42mg/100g na polpa concentrada, valores estes bastante expressivos. Pigmentos escuros solÃveis, luminosidade, hue, croma, carotenoides, teor de polpa, aÃÃcares totais apresentaram interaÃÃo significativa e foram avaliados por regressÃo variando com o tempo de armazenamento, exceto a coordenada de cor b*. Os teores de aÃÃcares totais mantiveram-se em torno de 10,01 a 13,25% nas polpas com conservantes e pasteurizadas a 24 a 27% na polpa concentrada, sendo estes em sua maioria representados por aÃÃcares redutores. As anÃlises microbiolÃgicas confirmaram a eficÃcia das etapas de processamento, tratamento tÃrmico e concentraÃÃo na manutenÃÃo da qualidade microbiolÃgica, uma vez que nÃo foi observado crescimento de microrganismos durante o perÃodo de armazenamento. Os nÃctares e os sucos tropicais adoÃados de caju apresentam-se na faixa de aceitaÃÃo sensorial em todos os atributos avaliados. O congelamento das polpas de caju com conservantes, pasteurizada e concentrada à viÃvel uma vez que nÃo ocorrem perdas significativas na qualidade dos produtos. A polpa de caju concentrada apresentou as melhores notas nos atributos sensoriais avaliados. / The cashew (Anacardium occidentale, L.) has a great economic importance to the Northeast region, notably for the great acceptance by consumers, both for their sensory properties (color, aroma, flavor, texture) as for its nutritional and functional values. It stands out among the fruit species native to the Northeast because it has high potential for fresh consumption and industrial processing. The cashew and cashew apple juice are important components of the human diet because they are considered a natural source of carbohydrates, carotenoids, vitamins and phenolic compounds, substances with high antioxidant potential, and have attracted the interest of various research groups. This work aimed to study the stability of cashew apple pulp with preservatives, pasteurized and concentrated frozen storage for 12 months, through to chemical, physical-chemical and microbiological analysis. And production of cashew apple nectar and cashew apple sweetened tropical juice and sensorial stability during 360 days of storage of the pulp. The pulps showed no significant interaction for pH, soluble solids, acidity and color coordinated. The pH and soluble solids varied with time but remained within standards legislation. The acidity no change during the storage. The color coordinate set to the cubic model. The parameters vitamin C ranged from 190.65 to 308.45 in the pulp with preservatives, 170.95 to 299.70 in the pulp pasteurized and from 514.68 to 865.42 mg/100g in concentrated pulp, these values very expressive. Dark pigments soluble, brightness, hue*, chroma*, carotenoids, pulp content, total sugar showed significant interaction were assessed by regression with time varying storage except color coordinate b. The concentration of total sugars remained around 10.01 to 13.25% for pulps with preservatives and pasteurized,and to 24 to 27% in the concentrated pulp, which are mostly represented by sugars. The microbiological analyses confirmed the effectiveness of the processing, thermal treatment and concentration in the maintenance of the microbiological quality, once growth of microorganisms was not observed in the product during the storage period. The cashew apple nectars and juices sweetened have good acceptability in all sensory attributes. The frozen pulps cashew with preservatives, pasteurized and concentrated is viable since no significant losses occur in the quality of products.
414

Morfometria e qualidade da água em microbacias do município de Guaçuí-ES

Gomes, João Batista de Oliveira 28 February 2012 (has links)
Made available in DSpace on 2016-12-23T14:37:28Z (GMT). No. of bitstreams: 1 Joao Batista de Oliveira Gomes.pdf: 1678687 bytes, checksum: 22733271d2132b74b590d748fa1086ac (MD5) Previous issue date: 2012-02-28 / No cenário mundial, a água passou a se tornar progressivamente um recurso disputado, tanto pela sua disponibilidade quantitativa, quanto qualitativa, para os mais diferentes usos. O acesso à água de boa qualidade deve ser garantido a todos os habitantes do planeta como direito básico de todos os seres vivos. O objetivo do estudo foi avaliar a morfometria e a qualidade da água superficial em microbacias no município de Guaçuí, localizado no sul do Estado do Espírito Santo, na Região da Serra do Caparaó. Foram selecionadas 10 microbacias da bacia do Ribeirão de São Tiago. Para o mapeamento e análise morfométrica das microbacias, foram utilizadas Ferramentas de Sistema de Informações Geográficas (SIGs). Para validação dos mapas usou-se a medida Kappa. Avaliaram-se 16 parâmetros físico, químicos e biológicos para determinar a qualidade da água e compará-los com os limites permitidos pela legislação. As coletas aconteceram entre os meses de setembro/2010 a agosto/2011 nos períodos de chuva e estiagem. A análise morfométrica mostrou que a bacia não está sujeita a enchentes e que sua declividade influencia na qualidade da água. As amostras analisadas mostraram que os parâmetros Sólidos Suspensos nas bacias com área agrícola, pastagens, café, frutas e hortaliças (AG), 10% apresentam uso moderado de uso e Turbidez, nas bacias de uso misto, agricultura e vegetação nativa (MC) apresentam 20% com uso inadequado para a agricultura. Nas bacias mistas (MC), período das chuvas, os níveis de potássio ficaram acima do recomendado para agricultura. As análises mostraram que o parâmetro coliforme termotolerante está fora dos limites recomendados pelo Ministério da Saúde para consumo humano / Globally, the water has become an increasingly contested resource, both for its availability quantitative and qualitative, for the most different uses. Access to good water quality must be guaranteed to all inhabitants of the planet as a basic right of all living beings. The aim of this study was to evaluate the morphology and surface water quality in watersheds in the county Guaçuí, located in the southern state of Espírito Santo, in the region of Serra do Caparaó. It Was selected 10 watersheds of the basin of the Ribeirão São Tiago. For mapping and morphometric analysis of micro, tools were used Geographic Information System (GIS). For validation of the maps used to measure Kappa. Sixteen parameters were evaluated physical, chemical and biological agents to determine the water quality and compare them to the extent permitted by law. Sampling took place between the months of the September/2010 to august/2011 during the rainy and dry seasons. The morphometric analysis showed that the basin is not subject to flooding and that its slope influences on water quality. The samples showed that the parameters suspended solids in the basins to cropland, pasture, coffee, fruits and vegetables (AG), 10% has moderate use of use and Turbidity in the basin mixed-use, agriculture and native vegetation (MC) are 20% with inappropriate use for agriculture. Basins mixed (MC), the rainy season, potassium levels were above the recommended level for agriculture. Analyzes showed that thermotolerant coliform parameter is outside the limits recommended by the Ministry of Health for human consumption
415

Caracterização físico-química e sensorial dos vinhos espumantes da serra gaúcha

Meneguzzo, Júlio 20 December 2010 (has links)
A influência da cultivar e da época de colheita na composição físico-química e na qualidade sensorial dos espumantes da Serra Gaúcha, Rio Grande do Sul, elaborados pelo método Champenoise nas safras 2006 e 2007, foi avaliada. As cultivares utilizadas foram Riesling Itálico, Chardonnay e Pinot Noir. As uvas foram colhidas em duas épocas distintas: uma referente ao ponto de colheita definido como ideal (época 1) e outra oito dias após (época 2). Os mostos, os vinhos base e espumantes foram analisados quanto à composição básica conforme a metodologia oficial brasileira. Além disso, nos vinhos base e espumantes foram analisados os elementos minerais e compostos aromáticos, através de absorção atômica e cromatografia gasosa, respectivamente. Os espumantes foram avaliados sensorialmente, por uma equipe de degustadores qualificados. Os resultados das análises clássicas dos mostos e vinhos base diferenciaram cultivares e épocas de colheita, nas duas safras estudadas. O mosto de Chardonnay apresentou maior valor de grau º Brix e de álcool potencial. O Pinot Noir se diferenciou pela acidez mais elevada, enquanto que o Riesling Itálico apresentou menores grau Brix e acidez total. Os mostos das uvas colhidas na segunda época apresentaram maiores teores de açúcar, álcool potencial, pH e relação brix/acidez total, e menor acidez. Nos vinhos base, as cultivares Chardonnay e Riesling Itálico apresentaram, respectivamente, maior e menor teor alcoólico e os vinhos das uvas de colheita mais tardia apresentaram menor acidez total. Entretanto, nos vinhos espumantes as análises clássicas não apresentaram diferenças significativas em relação às cultivares e épocas de colheita. Entre os elementos minerais dos vinhos base e dos espumantes correspondentes, o Zn foi único elemento que apresentou diferença significativa entre as cultivares sendo que os vinhos Chardonnay obtiveram os maiores teores. Os vinhos base provenientes das uvas com maior grau de maturação apresentaram, independente da cultivar, maiores níveis de K, Ca, Mg, Mn, Fe, Rb, Li e P e concentrações mais baixas em Cu e Zn. Quanto aos compostos voláteis, maiores quantidades de 2-fenil etanol e dietil succinato diferenciaram os vinhos da cultivar Chardonnay e maiores concentrações de hexanoato de etila e de acetato de isoamila diferenciaram os vinhos da cultivar Riesling Itálico. Já os vinhos Pinot Noir apresentaram teores de 2-metil-1-propanol e 2-metil-1-butanol significativamente superiores às outras variedades. Os vinhos obtidos de uvas colhidas na segunda época apresentaram menores teores de ácido butírico, diferenciando as duas épocas de colheita. Quanto à avaliação sensorial, a variedade Riesling Itálico apresentou maiores notas florais e a Chardonnay maior nota no frutado, tanto no aspecto olfativo quanto no gustativo. Já a Pinot Noir, maior nota vegetal, levedura e pão tostado. Na avaliação final os degustadores não fizeram distinção entre os espumantes Pinot Noir e os Chardonnay, preferindo estes aos de Riesling Itálico, nas duas safras estudadas. Na safra 2007 os degustadores preferiram os espumantes das uvas da primeira época de colheita, enquanto na safra 2006 não foi observada diferença entre as épocas de colheita. O presente trabalho contribuiu para a identificação dos principais constituintes e descritores que determinam a distinção e a tipicidade dos vinhos espumantes da Serra Gaúcha. / The influence of cultivar and harvest date on physico chemical composition and sensory quality of sparkling wines from Serra Gaúcha, Rio Grande do Sul, produced by the Champenoise method for crop years 2006 and 2007 were evaluated. The cultivars were Riesling Italico, Chardonnay and Pinot Noir. The grapes were harvested at two different times: one related to the harvesting point defined as ideal (season 1) and another eight days after (time 2). Musts, base wines and sparkling wines were analyzed based on the basic composition as the official Brazilian methodology. In addition, the base wines and sparkling wines were analysed the mineral elements were analyzed and aromatic compounds by atomic absorption and gas chromatography, respectively. Sparkling wines have been evaluated by a team of qualified tasters. The results of the classical analysis of musts and base wines differentiated cultivars and harvest times in the two seasons studied. The Chardonnay must showed higher brix value and potential alcohol. The Pinot Noir has distinguished by higher acidity, while the Riesling Italico had lower Brix and total acidity. The musts of grapes harvested in the second season showed higher levels of sugar, potential alcohol, pH and the realation Brix/total acidity and lower acidity. In the base wine, the varieties Chardonnay and Riesling Itálico were respectively higher and lower alcohol content and wine grapes harvested later showed lower acidity. However, in the sparkling wines the classic analysis showed no significant differences in different cultivars and harvest times. Among the mineral elements of the base wines and sparkling wines corresponding Zn was the only element that showed a significant difference among cultivars is that Chardonnay wines had the highest levels. The base wine from grapes with a higher degree of maturity showed, regardless of cultivar, higher levels of K, Ca, Mg, Mn, Fe, Rb, Li and P and lower concentrations of Cu and Zn. As for the volatile compounds, larger amounts of 2-phenyl ethanol and diethyl succinate differentiated the wines of the cultivar Chardonnay, and higher concentrations of ethyl hexanoate and isoamyl acetate differentiated the wines of the cultivar Riesling Italico. Already Pinot Noir wines showed levels of 2-methyl-1-propanol and 2-methyl-1-butanol significantly higher than other varieties. The wines made from grapes harvested in the second period had lower levels of butyric acid, differentiating the two harvest seasons. As for the sensory evaluation, the variety Riesling Itálico showed higher floral notes and the Chardonnay with highest score on fruity in both the olfactory and the gustatory aspect. As for the Pinot Noir, highest notes aromatic for vegetable, yeast and toasted bread. In the final evaluation the panelists made no distinction between the sparkling wines Pinot Noir and Chardonnay, preferring these to Riesling Itálico, in the two harvests studied. In the season 2007 the tasters preferred the sparkling wines from the grapes of the first harvest season, while the harvest in 2006 there was no difference between harvest seasons. This work helped identify the main components and characteristics that determine the distinguish and tipicity of sparkling wines from the Serra Gaúcha.
416

CARACTERÍSTICAS FÍSICAS, QUÍMICAS E ACEITABILIDADE DE SORVETE COM MANGABA E REDUZIDO TEOR ENERGÉTICO / PHYSICAL, CHEMICAL AND ACCEPTABILITY OF ICE CREAM WITH mangaba and REDUCED ENERGY CONTENT

SANTOS, Grazielle Gebrim 20 August 2008 (has links)
Made available in DSpace on 2014-07-29T15:22:57Z (GMT). No. of bitstreams: 1 Grazielle Gebrim Santos.pdf: 3503072 bytes, checksum: 8a2d0eb56712fefaa601f18b89e44ce0 (MD5) Previous issue date: 2008-08-20 / Mangaba (Hancornia speciosa Gomez) is a typical Cerrado biome fruit widely used in regional gastronomy and pharmacology. Its distinguished potentialities brought up increased interest and stimulated sustainable cultivation in the Northeast and Central West Regions of Brazil. The replacement of shortening and sugar on the physical and chemical properties of mangaba ice cream was evaluated, as well as its microbiological quality and acceptability. Four test formulas were elaborated: with partial replacement of sugar and total replacement of shortening for Selecta Light (SL), with total replacement of shortening for Dairy-Lo (DL), with total replacement of shortening for Litesse and sugar for Lactitol and sucralose (LLS), and with total replacement of shortening for Dairy-Lo and sugar for Lactitol and sucralose (DLS). Mangaba pulp and ice cream formulas accepted in the sensory test were subjected to chemical, physical and microbiological analyses. Mangaba pulp had a high moisture content (82.65%) and of titratable acidity (16.40%). All ice cream formulas were accepted by the sensory test and the highest mean (7.58) was obtained with the SL formula in the global acceptance, which significantly differed from the control. Moisture and total solids content differed significantly. SL protein concentration was similar to control, but significantly different from formulas DL and DLS. The largest reduction in the total energetic value (50%) was observed in the formulas prepared with Litesse, Lactitol, and Sucralose. Replacement of shortening, sugar or both resulted in overrun decrease and also affected viscosity. The highest melting rate was observed in formulas containing Dairy-Lo, Lactitol, and Sucralose. All formulas had a good level of appearance and global acceptance. Microbiological standards of mangaba pulp and ice cream formulas are in agreement with Brazilian legislation requirements. Mangaba ice cream with low energetic value, elaborated with Selecta Light or with a combination of Litesse, Lactitol, and Sucralose obtained the best quality characteristics. / A mangaba (Hancornia speciosa Gomez), fruto típico do cerrado amplamente utilizado na farmacologia e gastronomia regionais, tem despertado interesse crescente por causa das suas potencialidades, estimulando assim o seu cultivo de forma sustentável na região nordeste e centro-oeste. O efeito da substituição de gordura não-láctea e de sacarose nas propriedades físicas, químicas e aceitabilidade de sorvete com mangaba foi avaliado. Foram elaboradas quatro formulações teste: com substituição parcial da sacarose e total da gordura não-láctea por Selecta Light (SL), com substituição total da gordura não-láctea por Dairy-Lo (DL), com substituição total da gordura não-láctea por Litesse e da sacarose por Lactitol e sucralose (LLS), substituição total da sacarose por Lactitol, sucralose e da gordura não-láctea por Dairy-Lo (DLS). As análises físicas, químicas e microbiológicas foram realizadas na polpa de mangaba e nas formulações de sorvete aceitas em análise sensorial com 40 provadores. A polpa de mangaba apresentou elevado teor de umidade (82,65%) e acidez titulável (16,40%). Todas as formulações de sorvete foram aceitas na análise sensorial, sendo a maior média (7,58) observada no critério aceitação global para a formulação SL, que diferiu significativamente da formulação controle. O teor de umidade e sólidos totais das formulações diferiu significativamente. A concentração de proteína de SL foi semelhante ao controle, diferindo significativamente das formulações DL e DLS. Verificou-se para a formulação preparada com Litesse, Lactitol e Sucralose a maior redução do valor energético total (50%). A substituição de gordura, sacarose ou ambos promoveu a redução do overrun e afetou a viscosidade. A maior velocidade de derretimento ocorreu na formulação com Dairy-Lo, Lactitol e Sucralose. Todas as formulações tiveram bom nível aceitação global e aparência. A polpa de mangaba e os sorvetes estão de acordo com os padrões microbiológicos da legislação vigente. Sorvetes com mangaba, de reduzido valor energético, elaborados com Selecta Light ou com a combinação de Litesse, Lactitol e sucralose obtiveram as melhores características de qualidade.
417

Otimização do método de floculação orgânica de concentração viral para avaliação do impacto de tratamento por lodo ativado na Estação de Tratamento de Esgoto Barbosa Lage, Juiz de Fora - Minas Gerais

Assis, Andrêssa Silvino Ferreira 19 December 2016 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-13T17:29:42Z No. of bitstreams: 1 andressasilvinoferreiraassis.pdf: 3364177 bytes, checksum: ff9c20080e11e36f28daf805d56ecc7e (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-13T19:33:58Z (GMT) No. of bitstreams: 1 andressasilvinoferreiraassis.pdf: 3364177 bytes, checksum: ff9c20080e11e36f28daf805d56ecc7e (MD5) / Made available in DSpace on 2017-03-13T19:33:58Z (GMT). No. of bitstreams: 1 andressasilvinoferreiraassis.pdf: 3364177 bytes, checksum: ff9c20080e11e36f28daf805d56ecc7e (MD5) Previous issue date: 2016-12-19 / O tratamento de esgoto pode ser insuficiente para a completa eliminação de vírus entéricos, tais como adenovírus humanos (HAdV) e rotavírus do grupo A (RVA). Portanto, o retorno do lodo e do efluente tratado ao ambiente pode representar riscos à saúde pública. Este estudo foi conduzido para otimizar um protocolo de floculação orgânica para recuperação viral a partir de lodo de esgoto e efluente tratado, bem como realizar um monitoramento de HAdV e RVA na estação de tratamento de esgoto (ETE) de Juiz de Fora, MG. Nos estudos de otimização, foram propostas adaptações no protocolo de floculação com leite desnatado para lodo e efluente tratado, com modificações no tempo de agitação da amostra, na concentração final de leite desnatado e/ou na etapa de centrifugação. No estudo de monitoramento, esgoto bruto (P1), esgoto primário (P2), lodo (P3) e efluente tratado (P4) foram coletados bimensalmente em 2014 (durante as épocas seca e chuvosa), totalizando 96 amostras (simples e compostas). As cargas virais foram determinadas por PCR quantitativo e o bacteriófago PP7 foi usado como controle interno. Amostras de HAdV e RVA foram submetidas ao sequenciamento e a viabilidade das partículas de HAdV foi avaliada em amostras de P4. Os parâmetros físico-químicos e a contagem de coliformes termotolerantes (CT) foram determinados em cada ponto. Nos estudos de otimização, foram selecionadas duas condições que apresentaram as maiores taxas de recuperação viral no lodo (menor tempo de agitação e maior concentração de leite desnatado) e no efluente tratado (sem primeira etapa de centrifugação e com maior concentração de leite desnatado). Ambas provaram ser ferramentas úteis para pesquisa viral em amostras de campo, inclusive para a pesquisa de vírus gigantes. No monitoramento, o HAdV foi detectado em 85,4% (82/96) dos concentrados, com cargas virais variando de 3,27 x 102 a 2,42 x 106 cópias do genoma por mililitro (cg/mL), ao longo do ano. A presença de RVA foi observada em 52,1% (50/96) dos concentrados (1,38 x 103 a 3,65 x 105 cg/mL), com maior detecção na época seca. A carga viral não foi influenciada pelo tipo de amostra, sendo detectada tanto em amostras simples, quanto em amostras compostas. Todas as amostras de HAdV sequenciadas pertenciam à espécie F tipo 41 e as amostras de RVA pertenciam ao genótipo I1. O tratamento de esgoto reduziu a quantidade de matéria orgânica e sólidos, bem como a contagem de CT e as cargas virais. No entanto, a presença de HAdV e RVA foi observada mesmo após o tratamento, inclusive em amostras de efluente tratado consideradas adequadas pelas legislações atuais, com detecção de partículas infecciosas de HAdV. Foram observadas correlações positivas entre a carga viral e a demanda bioquímica de oxigênio, os sólidos sedimentáveis e sólidos suspensos totais. Os dois protocolos otimizados neste estudo podem ser facilmente adequados para uso em laboratório de rotina, podendo impulsionar o monitoramento viral nos subprodutos gerados na ETE. A carga viral detectada na ETE salienta a disseminação ambiental de RVA e HAdV e aponta o potencial do HAdV como um marcador viral de contaminação em ambientes aquáticos. / Sewage treatment may be insufficient for the complete elimination of enteric viruses such as human adenoviruses (HAdV) and group A rotaviruses (RVA). Thus, the return of sewage sludge and treated effluent to the environment poses concerns potential for public health. This study was conducted to optimize an organic flocculation procedure for viral recovery from sludge and treated effluent, and carry out a surveillance of HAdV and RVA in a wastewater treatment plant (WWTP) at Juiz de Fora, MG. In optimization studies, conditions were proposed for sludge and treated effluent with changes in the stirring time, in the final concentration of skimmed-milk and/or in the centrifugation step. In surveillance study, raw sewage (P1), primary sewage (P2), sludge (P3) and treated effluent (P4) were collected bimonthly in 2014 (during the dry and the rainy season), totaling 96 samples (simple and composite). Quantitative PCR determined viral loads and PP7 bacteriophage was used as internal control. HAdV and RVA strains were selected for sequencing, and the HAdV viability was evaluated in P4 samples. Physicochemical parameters and thermotolerant coliforms (TC) counting were determined at each point. After the optimization studies, two conditions were selected: the ones that showed the highest viral recovery rates in sludge (lower stirring time and higher concentration of skimmed-milk) and treated effluent (without the first centrifugation step and with a higher concentration of skimmed-milk). These conditions proved to be a useful tool for viral search in the field samples, including for the research of giant virus. In surveillance study, HAdV was detected in 85.4% (82/96) of the concentrated, with viral loads ranging from 3.27 x 102 to 2.42 x 106 genome copies per milliliter (gc/mL), throughout the year. RVA presence was observed in 52.1% (50/96) of the samples (1.38 x 103 to 3.65 x 105 gc/mL) with detection greater in the dry season. Viral load was not influenced by the type of sample being detected both in single samples, as in composite samples. All the sequenced HAdV strains belonged to species F type 41, and RVA strains belonged to genotype I1. Sewage treatment reduced the content of organic matter and solids, as well as the TC counts and the viral loads. However, the presence of HAdV and RVA was observed after treatment, even in samples considered adequate by current laws with detection of infectious HAdV particles. Positive correlations were observed between viral load and biochemical oxygen demand, sedimented solids and total suspended solids. Two optimized protocols in this study are easily suitable for routine laboratory use and can boost viral monitoring in by-products generated in the WWTP. Viral load detected in WWTP stress the environmental dissemination of HAdV and RVA and addressed the potential of HAdV as a virological marker of contamination in aquatic environments.
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Dégradation bio-physico-chimique des élastomères silicones : Influence du catalyseur de polycondensation et impacts environnementaux / Bio-physico-chemical degradation of silicone elastomers : Influence of polycondensation catalyst and environmental impacts

Laubie, Baptiste 24 October 2012 (has links)
Le classement de la famille des dibutylétains par l’Union Européenne comme reprotoxique et mutagène conduit les fabricants d’élastomères silicones à développer des solutions de remplacement de ces composés, largement employés comme catalyseur de réticulation. L’augmentation grandissante de la consommation de ce type d’élastomères amène à s’interroger sur leurs impacts dans les filières de traitement des déchets et sur l’influence du changement de catalyseur sur leur comportement environnemental. Ce domaine de recherche, très peu exploré, demande la mise en place d’une méthodologie spécifique, alliant des expériences de dégradations physico-chimiques et biologiques. Deux types d’élastomères simplifiés, réticulés par trois catalyseurs de polycondensation (un dibutylétain servant de référence et deux nouveaux) sont ciblés comme objet d’étude. Le premier axe, consacré à la matrice silicone, a permis de mettre en évidence une dégradation se déroulant en deux étapes successives, comme lors de la fin de vie de silicones fluides du type PolyDiMéthylSiloxane (PDMS). La première repose sur une hydrolyse chimique des chaînes siloxanes, formant majoritairement des oligosiloxanols (et principalement le monomère diméthylsilanediol) et des méthylsiloxanes cycliques (comme l’octaméthylcyclotétrasiloxane D4). La seconde est une biodégradation des sous-produits d’hydrolyse, aussi bien en aérobiose qu’en anaérobiose. Le second axe, consacré aux catalyseurs de polycondensation, prouve que ces composés prennent une place importante dans les mécanismes de dégradation. Ils impactent principalement les vitesses d’hydrolyse mais peuvent aussi influencer la nature des siloxanes relargués. De plus, ils ont des comportements totalement différents face à la dégradation biologique : ainsi, les catalyseurs organométalliques testés sont assimilables par les micro-organismes comme source primaire de carbone, alors que le catalyseur organique (un dérivé de guanidine) perturbe les métabolismes. Les composés biodégradables, même très peu mobiles en phase aqueuse, sont biodisponibles dans les élastomères et ont un impact sur la diversité des communautés bactériennes. Un champignon du genre Fusarium est d’ailleurs identifié comme capable de métaboliser une des nouvelles molécules développées. Le remplacement des dibutylétains permet de diminuer indiscutablement la toxicité des catalyseurs utilisés dans les élastomères silicones. La méthodologie mise en œuvre apporte de nombreuses informations quant aux impacts environnementaux et pourrait être transposée sans difficulté à l’étude d’autres matériaux. / Dibutyltin compounds are widely used as crosslinking catalysts in silicone elastomer industry. The classification of dibutyltins by the European Union as mutagenic and reprotoxic molecules lead manufacturers of silicone materials to develop alternatives. The increase of silicone elastomers demand requires to study their impacts during waste treatment and to assess the influence of the catalyst change on their environmental behavior. This unexplored area of research requires the establishment of a specific methodology, combining physico-chemical and biological degradation experiments. Two types of simplified elastomers are targeted in this study. They are crosslinked with three polycondensation catalysts: a dibutyltin derivative using as a reference and two new molecules. The first part, devoted to the silicone matrix, demonstrates a two stages degradation pathway in the environment. Silicone elastomers end-of-life is very similar to some silicone fluids, also known as PolyDiMethylSiloxanes (PDMS). The first stage is a chemical hydrolysis of siloxane chains, giving oligosiloxanols (mainly the monomer dimethylsilanediol) and cyclic methylsiloxanes (e.g. octamethylcyclotetrasiloxane D4). The second one is a biodegradation of hydrolysis by-products, in aerobic and anaerobic conditions. The second part, devoted to the polycondensation catalysts, demonstrates that these compounds play an important role in the degradation mechanisms. They mainly impact hydrolysis rates but also affect the nature of released products. In addition, they have a very distinct biological behavior: organometallic catalysts tested are assimilated as a single carbon source by microorganisms, while the organic catalyst (a derivative of guanidine) disrupts bacteria metabolism. Even if they have a limited mobility in the aqueous phase, biodegradable catalysts trapped in the silicone matrix are bioavailable and have an impact on bacterial communities. Moreover, a Fusarium fungus capable of metabolizing one of the new molecules developed is identified. The replacement of dibutyltin compounds undoubtedly reduces the toxicity of catalysts used to synthesized silicone elastomers. The methodology developed provides a lot of information about the environmental impacts of silicone elastomers and could be easily transposed to the study of other materials.
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The study of jatropha curcas oil-based biodegradable insulation materials for power transformer / Etude d'une huile biodégradable à base de Jatropha curcas comme matériau isolant pour transformateurs de puissance

Sitorus, Henry Binsar Hamonangan 30 September 2015 (has links)
Ce travail porte sur la caractérisation physico-chimique de l'huile de Jatropha Curcas et sa capacité à remplacer l'huile minérale dans les transformateurs de puissance. Ce produit présente plusieurs avantages sur les autres huiles végétales comme l'huile de palme ou l'huile de colza, qui recommandent sa production et son utilisation. En effet, la plante de Jatropha Curcas peut être cultivée sur des sols pauvres à faibles précipitations, évitant ainsi d'utiliser des sols plus fertiles pour sa culture permettant ainsi aux petits exploitants de réserver leurs terres aux cultures de base. Cette plante peut pousser facilement dans des zones où les niveaux de précipitations annuelles sont nettement inférieures à celles requises par d'autres espèces telles que le colza, le tournesol, le soja, le maïs, le palmier à huile et d'autres. Elle peut être cultivée sur tous les types de sol en Indonésie, même sur des terres arides, dans de nombreuses régions de l'Indonésie orientale, inexploitées en raison des difficultés à planter d'autres cultures. En outre, l'huile de Jatropha Curcas est un produit non alimentaire. En faisant subir à l’huile de Jatropha Curcas brute une estérification à base alcaline avec de l'hydroxyde de potassium (KOH), on obtient de l’huile de méthylester de Jatropha Curcas (JMEO) dont la viscosité et l’acidité sont acceptables pour les équipements à haute tension en particulier pour les transformateurs de puissance. Les propriétés physico-chimiques et électriques de JMEO ont été mesurées ainsi que celles de l'huile minérale (MO) pour la comparaison. Pour les propriétés physico-chimiques, il s’agit de la densité relative, la teneur en eau, la viscosité, l'acidité, l'indice d'iode, la corrosivité, le point d'éclair, le point d'écoulement, la couleur, l'examen visuel, et la teneur en ester méthylique. Quant aux propriétés électriques, elles concernent la rigidité diélectrique sous différentes formes de tension (alternative, continu et choc de foudre), les phénomènes de pré-claquage et de claquage sous choc de foudre, les décharges glissantes sur les surfaces de carton comprimé, immergé dans JMEO et MO. Les résultats obtenus montrent que les tensions de claquage moyennes en continu et en choc de foudre des huiles JMEO et MO sont très proches ; la tension de claquage moyenne de JMEO est même plus élevée que celle de l'huile minérale (de type naphténique). La mesure des tensions de claquage des mélanges d'huiles «80% JMEO + 20% MO» et «50% JMEO et 50% MO» montrent que la tension de claquage du mélange «80% JMEO + 20% MO» est toujours supérieure à celle de l'huile minérale sous tensions alternative et continue. Cela indique que le mélange d'huile minérale et de JMEO avec un rapport de 20:80 ne dégrade pas ses performances. Le mélange d'huiles peut se produire lors du remplacement de l'huile minérale par JMEO dans les transformateurs installés et en exploitation. L'analyse des caractéristiques des streamers (la forme, le temps d'arrêt, le courant associé et la charge électrique) se développant dans les huiles JMEO et MO sous tension impulsionnelle de foudre, montre une grande similitude. Aussi, la longueur finale (Lf) et la densité des branches des décharges surfaciques se propageant sur le carton comprimé immergé dans l'huile de Jatropha Curcas de méthylester (JMEO) et de l'huile minérale (MO), sous tensions de choc de foudre positif et négatif (1,2/50 μs), pour deux configurations d'électrodes divergentes (électrode pointe haute tension perpendiculaire et tangente au carton, respectivement), sont fortement influencées par l'épaisseur du carton comprimé. Pour une épaisseur donnée, Lf augmente avec la tension et décroît lorsque l'épaisseur augmente. Lf est plus long lorsque la pointe est positive que lorsque la pointe est négative. Pour une tension et une épaisseur du carton comprimé donnée, les valeurs de Lf dans l’huile minérale et l’huile JMEO sont très proches. [...] / This work is aimed at the investigation of the physicochemical characterization of Jatropha Curcas seeds oil and its capacity to be an alternative option to replace mineral oil in power transformers. This product presents several advantages that recommend both its production and usage over those of other vegetable oils as crude palm oil and rapeseeds oil. Indeed, it may be grown on marginal or degraded soils avoiding thus the need to utilize those more fertile soils currently being used by smallholders to grow their staple crops; and it will readily grow in areas where annual rainfall levels are significantly lower than those required by other species such as palm oil, rape-seeds oil, sunflower oil, soybeans oil, corn oil and others. For instance, these plants can grow on all soil types in Indonesia, even on barren soil. The barren soil types can be found in many parts of eastern Indonesia that remain untapped because of the difficulty planted with other crops. Moreover, jatropha curcas oil is nonfood crops. Jatropha Curcas oil was processed by alkali base catalyzed esterification process using potassium hydroxide (KOH) to produce Jatropha Curcas methyl ester oil (JMEO) has a viscosity and a acidity that are acceptable for high voltage equipment especially in power transformer. The physicochemical and electrical properties of JMEO were measured as well as those of mineral oil (MO) for comparison. The physicochemical properties cover relative density, water content, viscosity, acidity, iodine number, corrosivity, flash point, pour point, color, visual examination, and methyl ester content. Meanwhile the electrical properties cover dielectric strength under AC, DC and lightning impulse voltages, pre-breakdown / streamers under lightning impulse voltage, creeping discharge over pressboard immersed in JMEO and MO. The obtained results show that the average DC and lightning impulse breakdown voltages of JMEO and MO are too close, even the average AC breakdown voltage of JMEO are higher than that of mineral oil (napthenic type). The measurement of breakdown voltages of two oil mixtures namely “80% JMEO + 20% MO” and “50% JMEO and 50% MO” shows that the breakdown voltage of the first mixture (i.e., “80%JMEO+20%MO”) is always higher than that of mineral oil under both AC and DC voltages. This indicates that mixing 20:80 mineral oil to JMEO ratio does not degrade its performance. The mixing of oils can occur when replacing mineral oil by JMEO in installed transformers. The analysis of the streamers characteristics (namely; shape, stopping length, associated current and electrical charge) developing in JMEO and MO under lightning impulse voltages, shows that these are too close (similar). It is also shown that the stopping (final) length Lf and the density of branches of creeping discharges propagating over pressboard immersed in Jatropha Curcas methyl ester oil (JMEO) and mineral oil (MO), under positive and negative lightning impulse voltages (1.2/50 μs), using two divergent electrode configurations (electrode point perpendicular and tangential to pressboard), are significantly influenced by the thickness of pressboard. For a given thickness, Lf increases with the voltage and decreases when the thickness increases. Lf is longer when the point is positive than with a negative point. For a given voltage and thickness of pressboard, the values of Lf in mineral oil and JMEO are very close. It appears from this work that JMEO could constitute a potential substitute for mineral oil for electrical insulation and especially in high voltage power transformers.
420

Incorporation de fines issues de granulats recyclés dans la fabrication de nouveaux liants hydrauliques / The incorporation of powders made from recycled aggregates in the manufacture of new hydraulic binders

Nelfia, Lisa Oksri 06 July 2015 (has links)
Ce travail de thèse porte sur la valorisation de granulats recyclés dans la fabrication de nouveaux liants hydrauliques. Il s’inscrit dans une problématique actuelle de gestion des déchets du BTP, de sauvegarde des ressources naturelles et de réduction des gaz à effets de serre liés à la production de matériaux cimentaires. En quelques chiffres, sur les 260 millions de tonnes de déchets inertes produits annuellement par le secteur du BTP en France, 90 millions sont encore déposés en installations de stockage. C’est ce gisement qu’il convient de réduire pour accentuer la fabrication de granulats recyclés estimée aujourd’hui à 15 millions de tonnes/an. Dans cette perspective, ce travail de recherche a pour double objectif de valoriser des granulats recyclés sous forme de fines (Dmax < 80 µm) comme addition minérale en substitution du ciment pour les mortiers et bétons ou bien comme constituant principal de Liants Hydrauliques Routiers (LHR) pour le traitement des sols en place. Deux matériaux source sont utilisés, à savoir : un béton aux propriétés connues et maitrisées et un granulat issu d’une plateforme de recyclage représentatif d’une filière de production. De ces deux matériaux, des fines sont fabriquées par un protocole couplé de concassage et criblage avec ou sans traitement thermique à haute température puis caractérisées (caractérisation physico-chimique, minéralogique et réactivité hydraulique résiduelle) en vue d’établir une cartographie complète de leur potentiel de valorisation en fonction de leur origine. Le premier objectif intitulé « fabrication d’une addition minérale à base de fines » traite de l’effet de cette addition sur le comportement rhéologique, mécanique et sur les propriétés de durabilité de mortiers. Malgré un verrou normatif lié à l’utilisation de matières non référencées dans les normes des matériaux cimentaires, les résultats de ce travail démontrent la faisabilité d’introduire des fines en substitut d’additions classiques tel que le filler calcaire dans des proportions largement supérieures à celles imposées. Le second objectif intitulé « fabrication de liants hydrauliques routiers à base de fines » traite de la conception de LHR à base de fines pour le traitement des sols en place. C’est à partir d’un sol témoin reconstitué en laboratoire que deux familles de LHR à base de fines traitées et non traitées sont conçues, testées et comparées à des liants hydrauliques routiers commercialisés et enfin optimisées. / This thesis work focuses on the valorization of recycled aggregates as main component for hydraulic binders. This is included in a current issue of waste management, protection of natural resources and environment, reduction of greenhouse gases emissions in cement production. In France, on 260 millions tons of inert wastes produced per year, 90 millions tons are still stored in non-hazardous landfill. This waste deposit has to be reduced to increase the production of recycled aggregates currently estimated at 15 million tons per year. In view of this, this research is aimed to enhance the valorization of recycled aggregates into powder form (Dmax < 80 microns) as a mineral addition in substitution of cement for mortar and concrete or as main constituent of Hydraulic Road Binders (HRB). Two sources of materials are used : a five years old concrete and a recycled aggregates come from a recycling plant. Powders are prepared by crushing and sieving with or without high-temperature heat treatment and characterized (physical, chemical and mineralogical characterizations : residual hydraulic reactivity) to evaluate their potential valorization based on their origin.The first objective, entitled “Conception of mineral addition using powder of recycled aggregates”, deals with of the influence of this new materials on rheological, mechanical and durability properties of mortars. The results of this study allow us to evaluate the benefits of incorporating powder obtained by crushing/sieving of recycled aggregates as cement or limestone substitute used in the composition of a mortar. The second objective, entitled "conception of the Hydraulic Road Binders using powders of recycled aggregates", deals with the design of HRB by a comparative approach with HRB manufactured. The characteristics of binders are tested on mortars and on samples of treated soil and the results show that it's possible to produce an HRB rich in powders of recycled aggregates with or without cement which can efficiently stabilize clayey soils.

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