Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-08-07T14:31:04Z No. of bitstreams: 0 / Made available in DSpace on 2015-08-07T14:31:04Z (GMT). No. of bitstreams: 0 / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Neste trabalho foram realizados estudos para avaliaÃÃo e modificaÃÃo de derivados de petrÃleo e de bioderivados. Na primeira parte deste estudo foi avaliada a seletividade de adsorÃÃo de C8 aromÃticos em peneiras moleculares comerciais. A separaÃÃo dos isÃmeros de xilenos à um importante processo na indÃstria petroquÃmica. As tÃcnicas de cromatografia em headspace e pulsos cromatogrÃficos foram utilizadas para obtenÃÃo de dados experimentais de equilÃbrio de adsorÃÃo. Esta abordagem pode ser muito Ãtil para a seleÃÃo de adsorventes, bem como para investigar a variaÃÃo na seletividade em relaÃÃo à composiÃÃo e temperatura do processo. As seletividades de adsorÃÃo de misturas multicomponentes determinadas atravÃs do mÃtodo de pulsos cromatogrÃficos confirmaram os valores obtidos utilizando os experimentos de cromatografia em headspace. Os valores indicaram o carÃter de para-seletividade dos zeolitos Y (αpx/ox ~ 4) e beta (αpx/ox ~ 2) e de orto-seletividade para os zeolitos mordenita (αox/px ~ 1,5). Na segunda parte deste trabalho foi estudado o processo de adsorÃÃo de poliaromÃticos com misturas modelo e com amostras de Ãleos naftÃnicos pesados (ONP). Os experimentos com as misturas modelo serviram para estudar a capacidade de adsorÃÃo de poliaromÃticos dos materiais, avaliar os parÃmetros de processo e selecionar os materiais mais promissores (Norit 830W e Norit 1240 plus) para avaliaÃÃo com amostras de ONP. As amostras de ONP foram caracterizadas e apresentaram altos teores de poliaromÃticos (8,2% m/m). AtravÃs dos experimentos em coluna, foi possÃvel avaliar a capacidade de adsorÃÃo dos carbonos ativados, estimar parÃmetros de transferÃncia de massa e simular o comportamento breakthrough dos sistemas estudados. Foram avaliadas as propriedades fÃsico-quÃmicas e o teor de poliaromÃticos apÃs o tratamento. Os resultados confirmaram a eficiÃncia dos carbonos ativados para utilizaÃÃo em processos de reduÃÃo do teor de compostos poliaromÃticos de ONP. Na terceira e Ãltima parte deste trabalho foram estudadas as propriedades fÃsico-quÃmicas e resistÃncia oxidativa de bioderivados (biodiesel e biolubrificantes) do Ãleo de mamona. O uso de antioxidantes aumentou de 6 a 15 vezes a estabilidade das amostras de biodiesel. Os estudos de estabilidade dos biolubrificantes hidrogenados com os melhores antioxidantes mostraram elevaÃÃo do perÃodo de induÃÃo em 10 vezes. / In this work, the methods for evaluation and modification of petroleum-based and bio-based products were studied. In the first part of this study, the adsorption of C8 aromatics in commercial molecular sieves was evaluated. The separation of xylene isomers is an important issue in the petrochemical industry. Headspace and chromatographic pulse techniques were used to measure experimental equilibrium data. This approach is very useful for the selection of adsorbents, as well as in the investigation of selectivity variation, with respect to composition and process temperature. The adsorption selectivities of multicomponent mixtures determined by the chromatographic pulse method were in agreement with the values obtained using headspace technique. The aforementioned values indicate the character of para-selectivity in zeolites Y (αpx/ox ~ 4) and beta (αpx/ox ~ 2), as well as the ortho-selectivity for the mordenite zeolites (αox/px ~ 1.5). In the second part of this study, we studied the adsorption of polyaromatics using model samples and heavy naphthenic oils (HNO). The experiments with model solutions were used to study the capacity of polycyclic aromatic adsorption to evaluate the process parameters and to select the most promising adsorbents (Norit 830W and Norit 1240 Plus), with samples for the evaluation of the HNO. Therefore, the samples were characterized and the HNO had a high content of polyaromatics hydrocarbons (8.2% m/m). Through column experiments, it was possible to evaluate the adsorption capacity of activated carbons, estimating parameters and mass transfers to simulate the breakthrough behavior of the above systems. We evaluated the physicochemical properties and the content of polyaromatics after treatment. The results confirmed the efficiency of activated carbons as an alternative process to reduce polyaromatics content of a HNO. In the third part of this study, we analyzed the physicochemical properties and the oxidation resistance of bio-based products (biodiesel and biolubricants) of the castor oil. Hence, the use of antioxidants increased from 6 to 15 times the stability of castor oil biodiesel. Stability studies of hydrogenated biolubricants with the best antioxidants showed an elevation of the induction period by 10 times.

Made available in DSpace on 2014-10-09T12:43:41Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:09:56Z (GMT). No. of bitstreams: 1 06654.pdf: 9860874 bytes, checksum: a9212efd0462f2603abb2f237d62a703 (MD5) / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN/CNEN-SP

Submitted by Claudinei Pracidelli (cpracide@ipen.br) on 2015-08-07T14:31:04Z No. of bitstreams: 0 / Made available in DSpace on 2015-08-07T14:31:04Z (GMT). No. of bitstreams: 0 / De modo geral, os materiais termoplásticos são sensíveis à radiação ultravioleta (UV), a qual provoca mudanças em suas estruturas químicas, afetando suas propriedades, principalmente as mecânicas, e características de aparência. A radiação ultravioleta (10-400 nm), em especial na faixa entre 290- 400 nm, é bastante agressiva aos materiais plásticos resultando na quebra de cadeias e/ou reticulação. Para aplicações agrícolas, são fatores críticos para envelhecimento: a radiação solar total, temperatura, umidade relativa do ar, esforço mecânico, presença de agroquímicos, poluição do ar e a combinação desses fatores. Os aditivos estabilizantes de luz são adicionados aos plásticos para aumentar a durabilidade do produto final. Existem diversos sistemas estabilizantes de luz, desenvolvidos de acordo com a resina, aplicação final, tipo de cultivo e outras características. Além dos estabilizantes convencionais, como por exemplo, benzofenona, benzotriazol e as moléculas do tipo aminas estericamente bloqueadas (HALS), existem também aditivos inorgânicos baseados em nanotecnologia. Este estudo avalia diferentes sistemas de aditivos: HALS, nano carbonato de cálcio (nCaCO3 ou NPCC), nano óxido de zinco (nZnO) e nano dióxido de titânio (nTiO2), aplicados a 0,25 % e 0,75 % (em massa) em polietileno de baixa densidade linear (PEBDL) e copoliéster alifático aromático. As amostras foram envelhecidas em QUV-B simulando 6 meses de exposição à intempérie. Foram realizados testes de resistência à tração, termogravimetria (TG), calorimetria exploratória diferencial (DSC), índice de carbonila, espectroscopia na região do infravermelho com transformada de Fourier (FT-IR), microscopia eletrônica de varredura (MEV), microscopia de força atômica (AFM) e espectroscopia de absorção na região de ultravioleta e visível (UV-VIS). As propriedades das amostras não envelhecidas foram comparadas as envelhecidas para avaliar o desempenho dos vários sistemas de aditivos sobre o comportamento da degradação das amostras. Como resultado deste estudo, concluiu-se que há viabilidade da aplicação de nanopartículas como aditivos estabilizantes de luz (anti-UV), em especial o nZnO. Contudo, a aditivação do tipo HALS ainda mostrou-se mais eficaz, considerando os polímeros, sistemas de aditivação e proporções utilizadas. / Tese (Doutorado em Tecnologia Nuclear) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

This thesis deals with a contaminated area in the municipality of Östersund where a gas plant has previously been operating from 1914 to 1951. Operations at the property where the gas plant has been located currently consist of a workshop and commercial premises with associated car parking. In order to be able to build on the gas plant area, the municipality intends to implement post-treatment measures in the area. The substances found in the contaminated area (hotspot area E) are polycyclic aromatic hydrocarbons (PAH), aromatics, arsenic, nickel, lead and benzene. Measurement data indicate that these substances have been found at high levels, above the Swedish Environmental Protection Agency's guideline values for contaminated soil. Many areas today are polluted to the level that they pose great risks to the environment and people, and this thought requires the treatment of contaminated soil. A risk assessment for hotspot area E determined that PAH, aromatics, arsenic, nickel, lead and benzene pose an unacceptable risk, and the area is therefore deemed to need remediation. Based on nearby buildings, in-situ soil remediation is a suitable approach that fits. This study summarizes the progress made in remediation research and shows that soil remediation methods have different advantages and disadvantages, and different strains on human health and the environment. Based on this study, it may be more appropriate to wait for more efficient or cheaper remediation techniques to be developed, but with the idea that these substances are volatile, toxic, and dangerous to us humans and the environment. This means that they pose a potential risk to society and a tendency to spread easily. Conclusions that can be drawn are that all in-situ methods included in this work can be applied in Sweden based on the geological conditions. In order to achieve optimum in-situ soil remediation, site-specific conditions, such as large groundwater flow or heterogeneous soil, control the choice of remediation method.

Les interactions protéines-carbohydrates sont à la base de nombreux processus biologiques physiologiques aussi bien que pathologiques. Ces interactions incluent la synthèse et la dégradation enzymatique des oligosaccharides, la cohésion des tissus, l'immunité, le cancer ou encore l'infection bactérienne et virale. L'inhibition de ce type d'interaction par des molécules multivalentes synthétiques telles les glycopolymères, glycodendrimères, glycoclusters, etc. fait l'objet d'études importantes depuis plusieurs décennies. L'obtention de telles molécules pourrait permettre de développer de nouvelles thérapies qui pourraient palier notamment la multi-résistance aux antibiotiques. De plus, la détection de telles interactions par des méthodes simples et faciles à mettre en oeuvre permettrait une amélioration de la compréhension de ces phénomènes, ainsi que le diagnostic rapide de la présence de microorganismes. C'est dans ce contexte, que nous avons développé une nouvelle classe de composés glycosylés multivalents à coeur triazine. Ces glycoclusters de basse valence, ont la particularité de présenter une double fonctionnalité : l'inhibition d'interactions lectine-sucre par des effets de multivalence ainsi que la détection de ces interactions. Nous présentons dans ce manuscrit, la synthèse d'une nouvelle famille de glycoclusters polysulfurés à coeur triazine portant des épitopes saccharidiques tels que D-glucose, D-galactose, D-mannose, L-fucose, ainsi que leurs évaluations biologiques réalisées sur des lectines de Pseudomonas aeuriginosa. Nous avons ainsi mis en évidence la possibilité de reconnaître et de détecter les interactions lectine-sucre dans un premier temps par association d'un cluster mixte portant un fluorophore, et de façon plus sophistiquée, grâce à un système à géométrie variable incorporant dans le scaffold même un switch photochimique variant l'arrangement des sucres dans l'espace / Protein-carbohydrate interactions mediate a wide range of biochemical processes. Amongst these is the process of bacterial infection, which often proceeds through carbohydrate-binding lectins involved in biofilm formation. Even if the individual associations result from weak interactions, the assembly of multiple carbohydrate-protein interactions, typically more than additive, confers to the system the required specificity and avidity for their biological functions. In order to study this « glycocluster effects », a number of scaffold systems presenting multivalent carbohydrate ligands have been prepared in the literature. Dendrimers, polymers, peptides, calixarenes, to name a few, have been used as core molecules for the synthesis of multivalent glycoconjugates. The purpose of this work is to design new glycoclusters which exhibit dual functionality: the inhibition of carbohydrate-protein interactions via a multivalency effect; and detection of the interactions via fluorescence spectroscopy. A first generation of polysulfurated glycoclusters, organized around a heteroaromatic core, was synthesized using click chemistry reactions, which provided a family of highly soluble and readily accessible clusters. The glycoclusters were evaluated for their ligand-lectin interactions, multivalency effects, thermodynamic parameters, and abilty to modulate biofilm formation by Pseudomonas aeruginosa, a major causative agent of lung infections in cystic fibrosis patients. We describe a new family of ‘switchable glycoclusters’ based on photochromic behavior. They are designed to generate a modulated fluorescence signal as well as a defined change in the three-dimensional arrangement of the sugar epitopes, and may eventually provide significantly improved probes for studying the distribution, dynamics, interactions, and activities of specific lectins

Pine weevils cause major damage to newly planted conifer seedlings in reforestation areas. However, recent findings indicate that small (“mini”) seedlings, planted at the age of 7-10 weeks, are gnawed less by pine weevils than the larger, conventionally planted seedlings. Thus, it has been proposed that planting young conifer seedlings in clear-cut areas may reduce the damage caused by pine weevils. In attempts to determine why mini seedlings appear to be less damaged by pine weevils than “conventional” seedlings, the volatiles released by Norway spruce and Scots pine mini seedlings were investigated, since such chemicals are of great importance in herbivore-plant communication, inter alia acting as repellents, attractants or antifeedants. Volatiles from the seedlings were collected, separated and identified by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry. The results show that there are high levels of chemodiversity among both spruce and pine seedlings. Between-tissue and age-related variations in their emissions were also found. Norway spruce clones infested by mites were also examined to assess genotype- and pest-specific stress reactions of Norway spruce. Finally, the effects of certain spruce defense compounds on the behavior of the large pine weevil Hylobius abietis were examined. / QC 20100818

19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2117" Guodong Du. 12/19/2004. Report is also available in paper and microfiche from NTIS.

19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 1944" Lisa M. Ponton. 12/19/2004. Report is also available in paper and microfiche from NTIS.

19 Dec 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "IS-T 2695" Qinhua Huang. 12/19/2004. Report is also available in paper and microfiche from NTIS.