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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.
191

\"Avaliação dos resultados analíticos de hidrocarbonetos como instrumento jurídico em caso de derrames de petróleo: mangue de Bertioga\" / Evaluation of analytical results of hydrocarbons as judicial instrument in petroleum spills: Bertioga mangrove

Mauricio Antonio Covre Coimbra 26 February 2007 (has links)
A avaliação da presença de hidrocarbonetos de petróleo em mangue na região entre a Estrada Rio-Santos e o Canal Bertioga ? São Paulo ? Brasil foi realizada através da análise de amostras de sedimento coletadas em testemunhos em épocas distintas (2001 e 2005). O rompimento de um oleoduto em outubro de 1983 derramou 3.000.000 litros de petróleo (também analisado) nesse local. Esse óleo desceu pelo Rio Iriri até atingir o Canal de Bertioga, espalhando-se por cerca de 60 quilômetros. Uma batalha jurídica teve início em 1985 e se encontra atualmente em fase de execução da sentença. Neste trabalho foram descritas algumas questões jurídicas envolvendo o derramamento ocorrido e as análises químicas para serem utilizadas como nexo causal. Os hidrocarbonetos foram analisados através da extração com solvente orgânico em sistema Soxhlet e por cromatografia a gás com detecção de ionização de chama (GC-FID) para n-alcanos e alcanos isoprenóides e com espectrometria de massas (GC-MS) para biomarcadores de petróleo e compostos policíclicos aromáticos (CPAs). Os resultados dos hidrocarbonetos alifáticos somente permitiram avaliar a contribuição de origem petrogênica pela presença de mistura complexa não resolvida (UCM) em algumas amostras de sedimentos. Não foi possível avaliar a contribuição petrogênica nos sedimentos baseado nas concentrações de n-alcanos, de alifáticos totais e as relações pristano/fitano, pristano/n-C17 e fitano/n-C18. A relação entre os homólogos e isômeros dos biomarcadores de petróleo, entretanto, indicou a presença do petróleo derramado no mangue depois de duas décadas. As maiores concentrações dos biomarcadores de petróleo foram encontradas na região mais próxima do derramamento e nos topos dos testemunhos. As análises de CPAs nos sedimentos foram importantes para a identificação de compostos mutagênicos e carcinogênicos provenientes do petróleo derramado no mangue. / The evaluation of the presence of hydrocarbons of oil in mangrove in the region between the Rio-Santos Road and Bertioga Channel - São Paulo - Brazil was carried out through the analysis of sediment samples collected in cores in distinct times (2001 and 2005). The disruption of a pipeline in October of 1983 spilled 3,000,000 of liters of petroleum (also analyzed) in that area. That oil has gone down the Iriri River as far as the Bertioga Channel and has spread for about 60 kilometers. A judicial process has been started in 1985 and nowadays it is in the final phase when the sentence will be given by the law court. In this work some legal issues involving the occurred spilling and the chemical analyses have been described to be used as causal nexus. The hydrocarbons have been analyzed through an organic solvent extraction using Soxhlet apparatus and gas chromatography with flame ionization detection (GC-FID) for n-alkanes and isoprenoids alkanes, and with mass spectrometer (GC-MS) for petroleum biomarkers and polycyclic aromatic compounds (PACs). The analysis of the aliphatic hydrocarbons allowed evaluating only the contribution of petrogenic origin through the presence of unresolved complex mixture (UCM) in some sediment samples. It has not been possible to evaluate the petrogenic contribution in the sediments based on the concentrations of n-alkanes, total aliphatic hydrocarbons and the ratios between pristane/n-C17 and phythane/n-C18. The ratio between petroleum biomarker homologous and isomers has indicated the presence of the oil spilled in the mangrove after two decades. The highest concentrations of the petroleum biomarkers have been found in the region next to the spilling and in the top-core samples. The analyses of CPAs in the sediments have been important to the identification of mutagenic and carcinogenic compounds present in the petroleum spilled in the mangrove.
192

Toward green processes organic synthesis by catalysis with metal-doped solids / Vers des procédés verts : synthèse organique par catalyse avec des solides dopés aux métaux

Borghèse, Sophie 15 February 2013 (has links)
De nos jours, l’industrie chimique est de plus en plus confrontée à la question de son impact environnemental. Dans le même temps, elle doit faire face à la diminution des ressources de matières premières importantes tels que les métaux de transition, tout en respectant des contraintes économiques. Ces travaux de thèse avaient pour but de tenter de répondre à ces exigences, par le développement de méthodologies de synthèse basées sur l’utilisation de catalyseurs hétérogènes recyclables. En combinant les propriétés catalytiques de certains ions métalliques avec les propriétés de catalyseurs solides tels que les polyoxométallates ou les zéolithes, nous avons pu mettre au point de nouveaux outils pour la synthèse organique. Les polyoxométallates dopés à l’argent ont démontré leur efficacité dans le réarrangement d’alcynyloxiranes en furanes. La synthèse de spiroacétals et d’acétals par dihydroalkoxylation d’alcyne diols a été effectuée pour la première fois en catalyse à l’argent, via l’utilisation de zéolithes. En perspective, nous avons mis en évidence les applications potentielles de ces procédés verts dans la synthèse totale de molécules plus complexes. Les premiers résultats suggèrent que de telles synthèses plus respectueuses de l’environnement ont tout intérêt à être davantage utilisées à l’avenir. / Nowadays, the modern chemical industry has to deal with increasing environmental concerns, including the disposal of waste and its economic impact, or the diminution of important worldwide resources such as transition metals. In this Ph.D. thesis, we aimed to bring improvement in this area by the development of green processes, based on the use of recyclable heterogeneous catalysts. By combining the catalytic properties of several metal cations with the properties of solid catalysts such as polyoxometalates or zeolites, we were able to set up new tools for organic synthesis. Silver-doped polyoxometalates proved to be very efficient catalysts in the rearrangement of alkynyloxiranes to furans. Acetals and spiroketals were synthetized by dihydroalkoxylation of alkynediols under catalysis with silver-zeolites. As a perspective, we highlighted the potential applications of such green procedures in the total synthesis of more complex molecules. The first results suggested that these environmental friendly processes should gain increasing interest in the future.
193

Nutrição e ecologia nutricional de cervídeos brasileiros em cativeiro e no Parque Nacional das Emas - Goiás / Nutrition and nutritional ecology of brazilian cervids in captivity and in the Emas National Park - Goias

Alexandre Berndt 26 September 2005 (has links)
Existem poucas informações sobre exigências de energia de cervídeos brasileiros, dificultando o sucesso de manejo e reprodução em cativeiro. O conhecimento das exigências de energia também é importante para determinar os recursos necessários para sua conservação em parques e reservas. O primeiro objetivo deste experimento foi estudar as exigências nutricionais do veado catingueiro (Mazama gouazoubira) em cativeiro. O segundo objetivo foi observar o comportamento alimentar do veado-campeiro (Ozotoceros bezoarticus) no Parque Nacional das Emas (PNE), descrevendo qualitativamente e quantitativamente as principais espécies vegetais utilizadas para o aporte de nutrientes. A determinação das exigências de energia para mantença utilizou 8 veados-catingueiro de ambos os sexos em cativeiro e foi desenvolvida através de dois métodos: a)equilíbrio de peso e b)água duplamente marcada (2H2 18º). Os animais foram dosados com água duplamente marcada (111,8 mg/kgPV para 2H2O e 163,1 mg/kgPV para H2 18O) e amostras de sangue foram coletadas em intervalos de 3 dias, até que 3 ou 4 meias– vidas dos isótopos tenham decorrido (atingindo o limite de detecção em aproximadamente 30 dias após a dosificação). As curvas de desaparecimento dos isótopos em função do tempo foram utilizadas para calcular o “turnover” de CO2 e H2O. Os resultados obtidos pelos dois métodos foram semelhantes (111,4 e 112,0 kcal/kg.75.d) comprovando que a técnica da água duplamente marcada pode ser utilizada em estudos nutricionais de cervídeos. Informações de doses (mg/kgPV) e intervalo máximo entre aplicação e coleta de sangue (30 dias), permitem o uso desta metodologia em estudos futuros em vida livre. No PNE, veados-campeiro já monitorados com radio colares, permitiram a observação de seu comportamento alimentar. O experimento foi realizado em duas épocas distintas (inverno e verão). As espécies foram analisadas quanto à composição nutricional, para estimar valores energéticos assim como consumo de minerais e proteína. As contribuições das diferentes espécies que compõem a dieta dos cervídeos foram estimadas para duas populações em vida livre, uma com acesso apenas a espécies nativas (área central do parque) e outra com acesso às espécies cultivadas na periferia do PNE. Os sinais isotópicos do carbono 13 e os perfis de n-alcanos foram utilizados para quantificar a contribuição das diferentes espécies ingeridas. Os resultados indicaram que os veados-campeiro utilizam uma ampla gama de partes e espécies vegetais. Sua dieta é composta por aproximadamente 78 ítens, divididos em brotos (38,5%), folhas (15,4%), flores (17,9%), botões florais (12,8%), frutos e sementes (15,4%); de 55 diferentes espécies nativas e 7 culturas agrícolas. Há grande diferença no padrão de consumo entre as populações no interior do parque e aquelas que tem possibilidade de selecionar plantas cultivadas pelo homem. As espécies agrícolas podem contribuir com até 46,9% da dieta dos cervídeos da periferia do parque. Este trabalho determinou as exigências de energia de cervídeos brasileiros, validou o uso de uma técnica indireta para futuros estudos em vida livre e descreveu as espécies e partes utilizadas como aporte de nutrientes por cervídeos em vida livre. / There are limited data on energy requirements of brazilian cervids. Thus, it is difficult to succeed in their management and reproduction in captivity. Knowing the energy requirements is also important to determine the necessary nutritional resources for their conservation in parks and reserves. The first objective was to study the nutritional requirements of the grey-brocket deer (Mazama gouazoubira) in captivity. The second objective was to observe the feeding behavior of the pampas-deer (Ozotoceros bezoarticus) in the Emas National Park (ENP), describing qualitatively and quantitatively the main vegetal species used to supply these animals with nutrients. The determination of energy requirements for maintenance used 8 gray-brocket deer of both sexes in captivity and was carried through two methods: a)weight equilibrium and b)double-labeled water (2H2 18O). The animals were dosed with double-labeled water (111.8 mg/kgBW for 2H2O and 163.1 mg/kgBW for H2 18O) and blood samples were collected with 3 days interval, until 3 or 4 half lives of isotopes had occurred (reached limit of detection at approximately 30 days after the dosage). The curves of isotopes disappearance as a function of time were used to calculate the turnover of CO2 and H2O. The results obtained from the two methods were similar (111.4 and 112.0 kcal/kg.75.d) proving the double-labeled water technique may be used in nutritional studies of cervids. Information on doses (mg/kgBW) and maximum interval between injection and blood collection (30days), allow the use of this methodology in future studies with free ranging deer. In the national park, pampas-deer already monitored with radio colars, facilitated the observation of their feeding behavior. The experiment was conducted at two distinct seasons (winter and summer). The species were analyzed for the nutritional composition, to estimate energy values as well as mineral and protein consumption. The contributions of the different species to the diet of the cervids were estimated for two free ranging populations of the national park, one with access only to native species (central area of the park) and another with access to the crop species cultivated in the periphery of the park. The isotopic signals of carbon 13 and profiles of n-alkanes were used to quantify the contribution of different species to supply the energy demands. The results indicated that pampas-deer feeds on a broad spectrum parts and vegetal species. Its diet was composed of approximately 78 different parts, divided in sprouts (38.5%), leaves (15.4%), flowers (17.9%), floral buttons (12.8%), fruits and seeds (15.4%); from 55 different native species and 7 agricultural cultures. There is a great difference in the intake selection patterns between populations in the interior of the park and those that have access to cropland and the opportunity to choose feeding on native or cultivated plants. The agricultural species can contribute with up to 46.9% of deer diet of the park periphery. This work determined the requirements of energy of Brazilian cervids, validated the use of one indirect technique for use in free ranging animals and described the species and parts used to supply nutrients to cervids in the wild.
194

Avaliação do histórico de impactos antrópicos na bacia de drenagem do Lago das Garças (São Paulo-SP), durante o século XX, com base nos estoques de nutrientes, metais pesados e compostos orgânicos em sedimento lacustre / Evaluation of human impact at Garças lake drainage basin (São Paulo, SP) during the 20th Century based in nutrients, heavy metals and organic compounds in lacustrine sediments

Tatiane Araujo de Jesus 07 November 2008 (has links)
O presente estudo visou reconstruir o histórico de impactos antrópicos na bacia de drenagem do Lago das Garças durante o século XX por meio da deposição de contaminantes no compartimento sedimentar. O Lago das Garças está localizado em uma unidade de conservação, Parque Estadual das Fontes do Ipiranga (PEFI), inserida em área altamente povoada e urbanizada da cidade de São Paulo. Dois testemunhos de sedimento (LG05-03 e LG05-04, com 70 cm e 65 cm, respectivamente) foram amostrados mediante auxílio de mergulhadores no ponto mais profundo do reservatório, sendo, posteriormente, fatiados a cada 1 cm. Em LG05-03 foram quantificadas as distribuições verticais de carbono orgânico total (COT), nutrientes totais (NT e PT), hidrocarbonetos policíclicos aromáticos (HPA), hidrocarbonetos alifáticos (n-alcanos), bem como foi feita a classificação granulométrica. Em LG05-04 foi determinada a deposição de metais pesados (Co, Cr, Cu, Fe, Mn, Ni, Pb e Zn) e a geocronologia através do isótopo radioativo \'ANTPOT. 210 Pb\', usando o modelo CIC (Constant Initial Concentration). Os dados foram analisados por meio de análises estatísticas multivariadas (ACP: Análise de Componentes Principais). Com base nas tendências dos dados e na ACP, foi possível estabelecer três fases principais: Fase I: 64-43 cm (~1894-1975): caracterizada por baixas concentrações de nutrientes e contaminantes, sendo possível recuperar níveis préindustriais destes compostos, propostos como valores de referência regionais. Ainda, com base na razão C/N e em razões entre n-alcanos, notou-se, nesta fase o predomínio de aporte de matéria orgânica de origem alóctone; Fase II: 43-26 cm (~1975-1990): aumento abrupto das concentrações de metais pesados e HPA traçadores de veículos automotores, marcando o aumento da poluição atmosférica devido ao grande crescimento econômico do município e maior circulação de veículos na região. Ainda, foi observado aumento gradual das concentrações de NT e PT, atribuídos aos despejos de esgotos não tratados oriundos da Secretaria de Agricultura e Abastecimento e da Fundação Parque Zoológico; Fase III: 26-0 cm (~1990-2005): aumento mais acentuado das concentrações de nutrientes devido aos despejos de esgotos, acarretando em maior eutrofia do sistema, registrada pelo perfil do n-\'C IND.17\'. Pico das concentrações de HPA traçadores do uso de carvão mineral associado às atividades de uma siderúrgica vizinha (Siderúrgica J.L. Alipeti), bem como queda das concentrações destes traçadores coincidindo com mudanças no processo industrial da empresa. Ainda nesta fase notaram-se aumentos expressivos dos teores e fluxos dos HPA traçadores de veículos automotores, corroborando o cenário de aumento vertiginoso da frota de veículos na última década. Desse modo, este estudo contribuiu com o cenário nacional em termos de manejo de bacias hidrográficas urbanas, incluindo registros desde a época pré-revolução industrial no Brasil (~1894) até os dias atuais, demonstrando o potencial do uso de testemunhos lacustres no resgate de informações relativas à contaminação de ecossistemas aquáticos associadas às atividades antropogênicas. / Present study aimed to reconstruct the human impact history on the Garças Lake Drainage Basin during the 20th Century based on contaminants deposition on the lacustrine sediment. Garças Lake is located in a preservation area, the Parque Estadual das Fontes do Ipiranga (PEFI), located in a highly populated urban area within the city of São Paulo. Two sediment cores (LG05-03 and LG05-04, 70 cm and 65 cm long) were sampled by divers at the deepest site of the lake, which were sliced at 1 cm intervals. Information for LG05-03 included total organic carbon (TOC), total nutrients (TN and TP), polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons (n-alkanes) and grain size vertical distributions. Deposition of heavy metals (Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and the geocronology by \'ANTPOT. 210 Pb\', using CIC model (Constant Initial Concentration), were determined in LG05-04. Data were analyzed by multivariate statistic analysis (PCA, principal components analysis). Based on data trends and PCA, it was possible to recognized three main phases: Phase I: 64-43 cm (~1894-1975) characterized by low nutrients and contaminants concentrations, allowing retrieving preindustrial levels of these compounds, which are proposed as regional reference values. Besides, C/N ratio and n-alkanes ratios demonstrated aloctonous organic matter predominance; Phase II: 43-26 cm (~1975-1990) characterized by the abrupt increase of heavy metals and vehicular PAHs concentration, indicating the atmospheric pollution increase, due to the great economic rise experienced by the city of São Paulo over that time and the higher vehicles circulation in the region. Yet, it was observed a gradual increase in nutrient concentration attributed to the untreated sewage inputs from the São Paulo State Department of Agriculture and Provisioning headquarters and the city Zoo; Phase III: 26-0 cm (~1990-2005) characterized by a marked increase in nutrient concentration related to the untreated sewage inputs, leading to the increase of eutrophication, as registered by the n-\'C IND.17\' distribution. A peak of coal PAHs concentration was also noticed, related to a neighbor steel mill (J.L. Aliperti), followed by a subsequent decrease of these compounds, coincident with industrial procedures changes. Besides, there was an expressive increase in vehicular PAHs concentrations, corroborating the scenery of a drastic raise of vehicles in the last decade. The present study contributed to the national scenario towards urban drainage basin management. It included records since preindustrial time (~1894) up to the present, highlighting the potential use of lacustrine sediment on the retrieval of historical environmental changes of aquatic ecosystems and associated anthropogenic impacts.
195

O uso de esteróis, n-alcanos e fenóis da lignina como marcadores de fontes de matéria orgânica sedimentar em lagos de ria e lagos de várzea na bacia amazônica central (Brasil)

D´Angelo, Raffaela Araújo 14 December 2016 (has links)
Submitted by Biblioteca de Pós-Graduação em Geoquímica BGQ (bgq@ndc.uff.br) on 2016-12-14T15:05:41Z No. of bitstreams: 1 Tese Raffaela Araujo Dangelo.pdf: 3601516 bytes, checksum: e3eaa1bf8e5899920aadd3b101771782 (MD5) / Made available in DSpace on 2016-12-14T15:05:41Z (GMT). No. of bitstreams: 1 Tese Raffaela Araujo Dangelo.pdf: 3601516 bytes, checksum: e3eaa1bf8e5899920aadd3b101771782 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Programa de Doutorado Sanduíche no Exterior (PDSE - CAPES) / Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica Ambiental. Niterói, RJ / Neste trabalho, os esteróis, n-alcanos e fenóis da lignina foram aplicados como marcadores de fontes e dos níveis de degradação da matéria orgânica sedimentar presente em lagos com intensa hidrodinâmica. Os Lagos de Ria Manacapuru, Igarapé e Urubu e, os Lagos de Várzea Cabaliana, Janauacá, Mirituba, Canaçari e Curuaí localizados entre os municípios de Manaus e Santarém na Bacia Amazônica Central (AM, PA, Brasil) foram selecionados como área de estudos. Estes lagos possuem diferentes geomorfologia, hidrodinâminca e cobertura vegetal circundante. Amostras de sedimentos superficiais foram coletadas, nestes lagos, em cada uma das quatro estações do ciclo hidrológico amazônico (estiagem, chuvas, cheia e vazante) entre os anos de 2009 e 2011. Nestas amostras, foram identificados e quantificados os esteróis colesterol, colestanol, colestanona, ergosterol, estigmasterol, campesterol, sitosterol e sitostanol; os n-alcanos com cadeias curta C17 e C19 e, os com cadeias longa C21, C23, C25, C27, C29 e C31e, ainda, os fenóis da lignina. As razões entre os fenóis da lignina C:V e S:V e, o índice que identifica o grupo vegetal de origem destes fenóis (LPVI), foram calculados.Os teores de carbono orgânico total, a razão elementar C:N e o δ13C também foram determinados. Para a verificação dos níveis de degradação do material orgânico sedimentar, foram calculadas as razões sitostanol/sitosterol (Sit-nol/Sit-e), colestanona/colesterol (Col-na/Col-e), as quais relacionam o esterol que já sofreu degradação com o seu esterol precursor, ou seja, que ainda não sofreu degradação e, ainda, foi calculada a razão (Ad:Al)V, a partir do fenol aldeído (Al) que é o fenol da lignina mais suscetível a degradação bacteriana. As concentrações dos esteróis identificados variaram entre 1,1 – 518,7 μg gCO-1. Os resultados das cadeias de nalcanos variaram entre 0,3 – 201,6 μg gCO-1. Os fenóis da lignina apresentaram valores entre 10,3 – 222,5 μg gCO-1 e, ainda os resultados de δ13C variaram entre -35,2–-26,3 ‰. Os resultados das razões Sit-nol/Sit-e e Col-na/Col-e variaram entre 0,6 – 6,2 e 1,2 – 9,5, respectivamente. A razão (Ad:Al)V variou entre 0,4 – 2,5.A avaliação, em conjunto, dos resultados dos esteróis, n-alcanos, fenóis da lignina e do δ13C confirmaram que a principal fonte da matéria orgânica sedimentar presente tanto dos lagos de ria como do lagos de várzea são as plantas vasculares. Os resultados do índice LPVI (34.3 – 1662.3)avaliados em conjunto com a hidrodinâmica dos lagos, indicaram a predominância de material orgânico de plantas vasculares lenhosas nos Lagos de Ria Manacapuru, Igarapé e Urubu e, também nos Lagos de Vázea Cabaliana e Curuaí. Entretanto, estes resultados, demonstraram a predominância de plantas vasculares não lenhosas nos Lagos de Várzea Janauacá, Mirituba e Canaçari.Os valores ≥ 1,25das razões Sit-nol/Sit-e e Col-na/Col-e e, os valores > 0,4 da razão (Ad:Al)V, tanto nos lagos de ria como nos lagos de várzea, confirCoordenação de Aperfeiçoamento de Pessoal de Nível Superiormaram a predominância de moléculas de esteróis e de fenóis da lignina degradadas em relação as não degradadas. / In this work, was assessed the efficiency of the use of different organic matter tracers: sterols, n-alkanes, lignin phenols and δ13C. These tracers were used to identification of sources and degradation process undergone by sedimentary organic matter (SOM) of lakes with intense hydrodynamics. Three ria lakes (Manacapuru, Igarapé and Urubu) and five floodplain lakes (Cabaliana, Janauacá, Mirituba, Canaçari and Curuaí), localized between the cities Manaus and Satarém in Central Amazon Basin (AM, Brazil), were studied. These lakes have different geomorphologic, hydrodynamicsand vegetation coverages. Surface sediments samples were collect during the four seasons of the amazonian hydrologic cycle (low water – LW; rising water – RW; high water – HW and falling water (FW)) in 2009 and 2010. In these samples, the sterols (cholesterol, cholestenol, cholestanone, ergosterol, stigmasterol, campesterol, sitosterol and sitostenol), the n-alkanes with shot-chain (C17, C19) and long-chain (C21, C23, C25, C27, C29 e C31)and the lignin phenols were indentified and quantified. The rations C:V and S:V between the lignin phenols and the Lignin phenols vegetation index (LPVI),werecalculated.The total organic carbon, the ratio between the carbon and nitrogen (C:N) and isotopic (δ13C) were also determinatein these samples. With the aim to verify the degradation levels of the sedimentary organic matter of these lakes, the ratios sitostanol/sitosterol (Sit-nol/Sit-e), cholestanone/cholesterol (Col-na/ Cole), which relate the degraded sterolwith its precursor sterol. The ratio (Ad Al)V also calculate, because the aldehyde phenol (Al)is the phenol mostsusceptible to bacterial degradation. The results of the organic matter tracers range: sterols (1.1 – 518.7 μg gCO-1); n-alkanes (0.3 – 201.6 μg gCO-1); lignin (10.3 – 222.5 μg gCO-1) and δ13C (- 35.2–-26.3 ‰). The results of the Sit-nol/Sit-e and Col-na/Col-e rations range between 0.6 – 6.2 and 1.2 – 9.5, respectively. The (Ad:Al)Vratio range between 0.4 – 2.5. These results confirmed that the main origin of the sedimentary organic matter these lakes are vascular plants. The Lignin Phenols Vegetation index (LPVI) results (34.3 – 1662.3)evaluate togheter with the hydridinamic of each lake, indicated a predominance of organic matter from woody vascular plants in Ria Lakes Manacapuru, Igarapé and Urubu and in Floodplain Lakes Cabaliana and Curuaí. However, this index indicated predominance of organic matter from non-woody plants in Floodplain Lakes Janauacá, Mirituba and Canaçari. The values ≥ 1.25of the Sit-nol/Sit-e and Col-na/Col-e ratios and the values > 0.4 of the (Ad: Al)Vratio in both ria lakes as in the floodplain lakes confirmed the predominance of degraded sterols and lignin phenols compared to nondegraded
196

Intérêt de la symbiose mycorhizienne à arbuscules dans la phytoremédiation des sols historiquement contaminés par les hydrocarbures : de la protection à la dissipation / Interest of the arbuscular mycorrhizal symbiosis in the phytoremediation of aged-hydrocarbon contamined soils : from protection to dissipation

Lenoir, Ingrid 09 June 2015 (has links)
La phytoremédiaton assistée par les champignons mycorhiziens à arbuscules (CMA) compte parmi les méthodes émergentes de remédiation des sols pollués en raison de son adéquation avec le développement durable. Cette phytotechnologie présente un intêret à la fois dans la protection des plantes contre la phytotoxicité des polluants organiques tels que les hydrocarbures et dans leur dissipation. Cependant, son efficacité reste à prouver dans les sols historiquement multi-pollués. De plus, les mécanismes de dégradation et de tolérance mis en oeuvre par la symbiose mycorhizienne sont peu connus. Ainsi, ce travail de thèse avait pour premier objectif d'étudier chez les partenaires symbiotiques Medicago truncatula/Rhizophagus irregularis cultivés in vitro, l'expression de gènes potentiellement impliqués dans la tolérance au benzo[a]pyrène (B[a]P), un hydrocarbure aromatique polycyclique (HAP) de haut poids moléculaire fréquemment détecté dans les sols pollués. Pour cela, les expressions de gènes codant pour des enzymes antioxydantes, de détoxification des polluants et de réparation de l'ADN ont été mesurées par PCR quantitative en temps réel. Nos résultats ont montré une corrélation positive entre l'induction des systèmes antioxydants au niveau génique et enzymatique et la production d' H₂O₂ induite par l'accumulation de B[a]P dans les racines non mycorhizées et le CMA. En revanche, lorsque les racines sont colonisés par le CMA, celui-ci agirait comme une barrière physique en limitant l'accumulation de B[a]P et la production d'H₂O₂ dans les racines, et provoquerait la répression des systèmes antioxydants racinaires. Le second objectifs de cette thèse a consisté à évaluer l'apport d'un amendement mycorhizien dans la dégradation de deux types d'hydrocarbures : les HAP et les alcanes, présent dans un sol historiquement multi-pollué (site de l'Union). L'étude a été conduite en microcosmes en présence de blé (Triticul aestivum) inoculé ou non par R. irregularis. Une contribution positive de cette inoculation dans la biodégradation des hydrocarbures après 16 semaines de culture a été démontrée. Cette meilleure dégradation serait liée notamment à la stimulation de la microflore bactérienne du sol mais également aux capacités métaboliques de la plante. / Arbuscular mycorrhizal fungi (AMF)-assisted phytoremediation is one of innovative method for the remediation of polluted soils due to its relevance to sustainable development. This phytotechnology presents benefits both in the protection of plants against the phytotoxicity of organic pollutants such as hydrocarbons and in their dissipation. However, its efficiency remains to be proved in the aged multi-polluted soils and the mechanisms of degradation and tolerance implemented by the mycorrhizal symbiosis are poorly known. Thus, the thesis aims firstly to study in the symbiotic partners Medicago truncatula/Rhizophagus irregularis cultivated in vitro, the expression of genes potentially involved in the tolerance to benzo[a]pyrene (B[a]P), a high molecular weight polycyclic aromatic hydrocarbon (PAH) frequently detected in polluted soils. Expressions of genes encoding for antioxidant, pollutant, detoxification and DNA repairing enzymes were measured by real time PCR. Our results showed a positive correlation between the induction of antioxidant systems (genes and enzymes) and the production of H₂O₂ induced by the accumulation of B[a]P in non-mycorrhizal root and the AMF. In contrast, when the roots are colonized by the AMF, this one would act as a physical barrier limiting the accumulation of B[a]P and H₂O₂ production of in the roots and would cause the repression of root antioxidant systems. The second objective of the thesis consisted of evaluating the contribution of the arbuscular mycorrhizal amendment in the degradation of two types of hydrocarbons : the PAH and the alkanes, present in an aged multi-polluted soils (site of Union). The study was carried out in microcosms in the presence of non-inoculated or inoculated wheat (Triticul aestivum) by R. irregularis. A positive contribution of the mycorrhizal inoculation in the hydrocarbon biodegradation after 16 weeks of culture was demonstrated. This better degradation is related especially to the simulation of the bacterial microflora but also to the plant metabolic abilities.
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Application of Biomarkers and Compound Specific Stable Isotopes for the Assessment of Hydrology as a Driver of Organic Matter Dynamics in the Everglades Ecosystem

He, Ding 25 June 2014 (has links)
The Everglades is a sub-tropical coastal wetland characterized among others by its hydrological features and deposits of peat. Formation and preservation of organic matter in soils and sediments in this wetland ecosystem is critical for its sustainability and hydrological processes are important divers in the origin, transport and fate of organic matter. With this in mind, organic matter dynamics in the greater Florida Everglades was studied though various organic geochemistry techniques, especially biomarkers, bulk and compound specific δ13C and δD isotope analysis. The main objectives were focused on how different hydrological regimes in this ecosystem control organic matter dynamics, such as the mobilization of particulate organic matter (POM) in freshwater marshes and estuaries, and how organic geochemistry techniques can be applied to reconstruct Everglades paleo-hydrology. For this purpose organic matter in typical vegetation, floc, surface soils, soil cores, and estuarine suspended particulates were characterized in samples selected along hydrological gradients in the Water Conservation Area 3, Shark River Slough and Taylor Slough. This research focused on three general themes: (1) Assessment of the environmental dynamics and source-specific particulate organic carbon export in a mangrove-dominated estuary. (2) Assessment of the origin, transport and fate of organic matter in freshwater marsh. (3) Assessment of historical changes in hydrological conditions in the Everglades (paleo-hydrology) though biomarkes and compound specific isotope analyses. This study reports the first estimate of particulate organic carbon loss from mangrove ecosystems in the Everglades, provides evidence for particulate organic matter transport with regards to the formation of ridge and slough landscapes in the Everglades, and demonstrates the applicability of the combined biomarker and compound-specific stable isotope approach as a means to generate paleohydrological data in wetlands. The data suggests that: (1) Carbon loss from mangrove estuaries is roughly split 50/50 between dissolved and particulate carbon; (2) hydrological remobilization of particulate organic matter from slough to ridge environments may play an important role in the maintenance of the Everglades freshwater landscape; and (3) Historical changes in hydrology have resulted in significant vegetation shifts from historical slough type vegetation to present ridge type vegetation.
198

Computational Study Of Long Chain N-alkane Binary Mixture Adsorption In Silicalite Under Conditions Of High Loading

Ganesh, Hari S 12 1900 (has links) (PDF)
The study of adsorption of n-alkanes in zeolite pores represents both a fundamental problem in molecular thermodynamics and also a problem with substantial industrial importance. Until mid 19th century, adsorption was mainly used for purification processes such as removal of H2S and mercaptans from natural gas and organic matter from water. However, with the emergence of molecular sieves, especially zeolites, adsorption processes have become an attractive alter- native to distillation in large scale separation of mixtures that have low relative volatility into streams each enriched in one of the components. The pore di- ameters of molecular sieves are of the order of molecular diameters and hence selective adsorption can be achieved by both a difference in adsorbate-adsorbent interactions of various species and obstruction by the pore walls to some of the species in the mixture. The existing adsorption theories such as Henry’s law, Langmuir adsorption model and BET isotherm are incapable of predicting the adsorption isotherms of n-alkanes in zeolite pores. The reason is that in microporous adsorbents, the sorbate molecular mechanisms are influenced by geometrical constraints also. This limitation in the use of theory can be overcome by developing a molecular model and using computers to mimic the real system. This nature of simulation is called molecular simulations. With the development of advanced algorithms, improved force-field parameters and very high computational power of present day computers, molecular simulations have become an important tool in studying adsorption on micro-porous materials. Adsorption experiments of mixtures of long chain alkanes into silicalite under liquid phase conditions show selectivity inversion and azeotrope formation. These effects are due to the subtle interplay between the size of the adsorbed molecules and pore topology of the adsorbent. The underlying molecular mechanisms responsible for selective uptake of one of the components cannot be obtained from experiments but can be realized through simulations. Therefore, in this study, the selective uptake of lighter component during liquid phase adsorption of C14/C15 and C15/C16 n-alkane binary mixtures in the zeolite silicalite is understood through configurational bias grand canonical Monte Carlo (CB- GCMC) molecular simulation technique and a course-grained siting analysis. The simulations are conducted under conditions of low and high loading. The siting pattern of the adsorbates inside the zeolite pores is used to explain the selectivity as seen in experiments.
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Investigação da introdução da matéria orgânica no sedimento do Rio Paraibuna e o papel dos hidrocarbonetos alifáticos como marcadores biogeoquímicos no monitoramento de contaminações antrópicas

Araujo, Fausto Moreira 20 March 2015 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2015-12-18T17:00:14Z No. of bitstreams: 1 faustomoreiraaraujo.pdf: 3458303 bytes, checksum: 1018968a4d60b355a7d1902eb73fe9b7 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-01-25T15:35:15Z (GMT) No. of bitstreams: 1 faustomoreiraaraujo.pdf: 3458303 bytes, checksum: 1018968a4d60b355a7d1902eb73fe9b7 (MD5) / Made available in DSpace on 2016-01-25T15:35:15Z (GMT). No. of bitstreams: 1 faustomoreiraaraujo.pdf: 3458303 bytes, checksum: 1018968a4d60b355a7d1902eb73fe9b7 (MD5) Previous issue date: 2015-03-20 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho foi realizada a determinação de hidrocarbonetos alifáticos (n-alcanos e isoprenóides) marcadores biogeoquímicos do petróleo e de seus derivados, em amostras de sedimento do rio Paraibuna. A amostragem foi feita para 16 pontos ao longo do rio no município de Juiz de Fora-MG, coletados com draga Petersen. Para a extração dos analitos da matriz, realizou-se otimização da condição de extração por planejamento Box-Bahnken 33 por ultrassom. A condição escolhida para extrair os analitos foi de um tempo de sonicação de 10 minutos, com 10 mL de solvente e composição da mistura de solventes composta por n-hexano e acetona (25:75). Os extratos foram eluidos em coluna de adsorção constituída por sílica, alumina e sulfato de sódio utilizando 16 mL de n-hexano para total eluição dos extratos. A análise do eluato foi realizada pela técnica de cromatografia a gás acoplada à espectrometria de massas. Para complemento dos resultados, foi determinado a granulometria do sedimento e teores de carbono orgânico total (COT) em cada ponto. Obteve-se forte correlação do COT, com os teores de silte + argila. De maneira geral, o sedimento do rio Paraibuna é basicamente constituído por areia. Para pontos que o teor de silte e argila foram baixos, não foi possível a quantificação de vários analitos. A concentração de alifáticos totais encontrada variou de 0,78 a 1318,18 μg g-1 peso seco, e de n-alcanos totais de 0,07 a 5,49 μg g-1 peso seco, sendo observado um aumento da concentração dos compostos ao longo do rio na direção e sentido de seu fluxo. O índice preferencial de carbono obtido abrangeu de 0,94 a 4,75, indicando introdução de n-alcanos no sedimento do rio por fontes antrópicas para algumas amostras. Dos 16 pontos coletados, 12 apresentaram mistura complexa não resolvida, sendo 50% de perfil unimodal, e 50% bimodal, em decorrência de poluição por combustíveis e derivados do petróleo. A razão terrestre/aquática associada com a razão C31/C19 apontaram domínio das contribuições terrígenas por plantas vascularizadas para todos os pontos coletados. / In this work, it was performed the determination of n-alkanes (C10-C40) biomarkers crude oil and its derivatives, in river sediment samples. The sampling was performed with 16 points along Paraibuna river in Juiz de Fora-MG, collected with Petersen dredge. A 33 Box-Behnken experimental design was used to optimize the ultrasound-assisted extraction conditions. The optimized conditions was 10 minutes of sonication with 10 mL solvent mixture and the mixture composition was n-hexane and acetone (25:75). The extracts were eluted in an adsorption column containing silica, alumina and sodium sulfate, using 16 mL of n-hexane for total elution of the extract. The eluated analysis was performed by gas chromatography coupled with mass spectrometry. In addition, it was verified the sediment granulometry and the total organic carbon (TOC) determination for each sampling. We obtained a strong correlation between TOC and the silt + clay. In general, Paraibuna river’s sediment are basically constituted by sand. For points that the concentration of silt + clay were low, it was not possible to detect several analytes. The concentration of total aliphatic ranged from 0.78 to 1318.18 μg g-1 dry weight and the total n-alkanes ranged from 0.07 to 5.49 μg g-1 dry weight, being observed an increase in the concentration of compounds in the direction of river flows. The obtained carbon preference index ranged from 0.94 to 4.75, indicating introduction of n-alkanes by anthropogenic sources for some samples. From the 16 collected points, 12 presented an unresolved complex mixture, being 50% of unimodal profile and 50% bimodal, as result of pollution from fuel oil and other petroleum derivatives. In all points, it was observed the domain of terrigenous sources contributions over the aquatic sources.
200

Charakterizace chemického složení dehtu po zplyňování biomasy / Characterization of the chemical composition of the tar produced in the gasification of biomass

Mahelová, Zora January 2016 (has links)
Biomass is a renewable source of energy and represents an acceptable alternative to fosil fuels. Usable methods of energetic use of biomass are combustion and gasification. Main interest is focused on gasification in last years. Gasification is based on conversion of organic material to usable gaseous product called syngas, which can be used as a fuel for energy production. Large amount of tar is formed as a by-product of incineration and gasification of biomass. Tar is composed by various mixture of organic substances, has a negative effect on operating conditions and is a potential threat to environment. Experimental part of this study was focused on analysis of tar obtained by gasification of various kind of biomass. Selected groups of hydrocarbons and oxygen compounds were identified in analysed samples. Individual biomass samples were compared regarding to determined relative content of selected substances. Analysis was done by complete twodimensional gas chromatography with mass spectrometric detection (GCxGC/TOF-MS).

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