Car exhaust catalysts were introduced in the early 1980’s, to limit the release of pollutants such as hydrocarbons, carbon monoxide and nitrogen oxides. These catalysts contain noble metals such as palladium (Pd), platinum (Pt) and rhodium (Rh) and are able to simultaneously abate all three of the above-mentioned pollutants, hence the name three-way catalyst (TWC). The exposure to high temperatures (800-1000 °C) during operation and the presence of additives in gasoline and lubricants will, after a certain time, lower the activity of the TWC. High temperatures reduce the active area by causing the noble metals to agglomerate and sinter, whereas the additives alter the activity either by fouling the pores of the support material or by interacting with the metals. The main objective of this work was to develop a method which allows for the removal of contaminants (additives) from the washcoat and enables the redispersion of the active sites (noble metals), in an effort to recover lost catalyst activity. For this purpose, regeneration experiments were carried out on a wide spectrum of different commercial car exhaust catalysts. The influence of a thermal treatment in a controlled gas atmosphere, such as oxygen or hydrogen, and a redispersing agent, e.g. chlorine, on the activity of TWC was investigated by means of laboratory-scale activity measurements. Several complementary characterization methods such as SEM/TEM, XRD, BET, LA, XPS and TPR were employed to verify the effects of the regeneration treatments on the catalyst morphology (Papers I, II). The results show that partial regeneration of catalyst activity and noble metal dispersion was achieved after thermal treatment in an oxygen-chlorine rich atmosphere at temperatures below 500 °C. A wet-chemical regeneration treatment with dilute oxalic and citric acid solutions is evaluated in Paper III. These acidic solutions are able to dissolve and remove contaminants from the washcoat, thus partly restoring the catalyst activity. An investigation of the effects of an oxy-chlorine thermal treatment for regeneration of a ‘full-scale’ commercial automotive three-way catalyst was carried out (Paper IV). Improved catalyst activity for a high mileage catalyst could be observed, with emissions lowered by approximately 30 to 40 vol.% over the EC2000 driving cycle. The properties of fresh, aged and regenerated catalysts were then studied by means of labscale experiments, on a local as well as a global level using a mathematical model (Paper V). The model allows for comparison of the intrinsic properties of the active surface by deriving and tuning parameters of a fresh catalyst and verifying the activity of a regenerated or aged catalyst. / QC 20100812

Στην παρούσα εργασία μελετάται η αντίδραση αναγωγής των οξειδίων του αζώτου με προπυλένιο σε ισχυρά οξειδωτικές συνθήκες με χρήση καταλυτών Rh υποστηριγμένων σε τροποποιημένους φορείς TiO2 με ιόντα διαφορετικού σθένους (W6+ ή Ca2+) από το μητρικό κατιόν (Ti4+). Η τροποποίηση του φορέα επιτεύχθηκε με την διάχυση των ενισχυτικών κατιόντων στο κρυσταλλικό πλέγμα του TiO2 σε υψηλές θερμοκρασίες. Στους φορείς που παρασκευάστηκαν πραγματοποιήθηκαν μετρήσεις ειδικής επιφάνειας (ΒΕΤ), κρυσταλλικής δομής (XRD), ειδικής αγωγιμότητας (AC-Impedance) καθώς και μετρήσεις επιφανειακής οξύτητας (TPD-MS). Σε γενικές γραμμές η ενίσχυση του φορέα TiO2 έχει σαν αποτέλεσμα την διατήρηση της ειδικής επιφάνειας, την αύξηση της επιφανειακής οξύτητας, και την αλλαγή της ειδικής αγωγιμότητας σε σχέση με τον μη ενισχυμένο φορέα. Οι υποστηριγμένοι καταλύτες Rh παρασκευάστηκαν με την μέθοδο του υγρού εμποτισμού από νιτρική πρόδρομη ένωση. Οι καταλύτες που παρασκευάστηκαν χαρακτηρίστηκαν ως προς την διασπορά της ενεργού φάσης καθώς και του μέσου μεγέθους των κρυσταλλιτών του μετάλλου με χημορόφηση H2. Η σύγκριση των καταλυτών με βάση την ενεργότητα τους για την αναγωγή του ΝΟ καθώς και την εκλεκτικότητά τους σε Ν2, έδειξε δύο διαφορετικές δράσεις της ενίσχυσης. Ενίσχυση με ιόντα W6+, οδηγεί σε αύξηση της ενεργότητας με παράλληλη ελαφρά αύξηση της εκλεκτικότητας σε Ν2. Η ενίσχυση του καταλύτη με ιόντα Ca2+ οδηγεί σε αύξηση της ενεργότητας για την αναγωγή του ΝΟ με παράλληλη όμως, σημαντική μείωση της εκλεκτικότητας σε Ν2. Η συμπεριφορά αυτή ερμηνεύτηκε με βάση το θεωρητικό υπόβαθρο που περιγράφει τις τροποποιήσεις των ηλεκτρονιακών ιδιοτήτων του φορέα και είναι γνωστό ως φαινομένου DIMSI. Η βελτίωση των καταλυτικών ιδιοτήτων που παρουσιάζουν οι ενισχυμένοι καταλύτες έδωσε το ερέθισμα για την μελέτη του μηχανισμού της αντίδρασης για την αναγωγή του ΝΟ με προπυλένιο στους καταλύτες αυτούς καθώς και τις διαφορές που παρουσιάζουν σε σχέση με τον μη-ενισχυμένο καταλύτη. Η μελέτη του μηχανισμού πραγματοποιήθηκε με χρήση των τεχνικών υπέρυθρης φασματοσκοπίας (FTΙR) και φασματοσκοπίας μάζας (Mass Spectroscopy). Σε γενικές γραμμές τα αποτελέσματα δείχνουν ότι το ΝΟ ροφάται μοριακά σε κέντρα Rh. Παρουσία ανηγμένων κέντρων το ΝΟ διασπάται προς ατομικά ροφημένα είδη Ν και Ο. Ανα-συνδυασμένη εκρόφηση των ειδών Ν οδηγούν στον σχηματισμό Ν2 στην αέρια φάση, ενώ παραγωγή του Ν2Ο σχετίζεται με την δημιουργία του συμπλόκου είδους Rh(NO)2. Η αναγέννηση των ενεργών κέντρων επιτυγχάνεται με την μερική οξείδωση του προπυλενίου σε οξειδωμένα κέντρα Rh αρχικά προς ακρολεϊνη. Περαιτέρω οξείδωση της ακρολεϊνης οδηγεί στον σχηματισμό θραυσμάτων COO- και CHx με τον ενδιάμεσο σχηματισμό ειδών του τύπου του ακρυλικού οξέος. / In the present study, the catalytic reduction of NO with propylene in the presence of excess oxygen was examined, over Rh catalysts supported on doped TiO2 carriers with tungsten or calcium cations. Doped TiO2 carriers were prepared employing the solid state diffusion technique at elevated temperatures. Characterization of doped carriers consisted of specific surface (BET) area and crystalline mode (XRD) measurements as well as measurements of the specific conductivity (AC-Impedance) and surface acidity (TPD-MS). In general, doping TiO2 results in an increase of the surface acidity, in alterations of specific conductivity and in the preservation of the specific surface in a manner, which depends on dopant concentration and calcinations temperature. Supported Rh catalysts were prepared following the wet impregnation method using Rh(NO3)3 as the precursor metal compound. Characterization of the prepared catalysts consisted of dispersion and mean metal crystalline size measurements, employing hydrogen chemisorption at ambient temperature. Comparison of the doped catalysts, as far as the activity toward NO reduction and the selectivity to N2 is concerned, shows two different behaviors. Doping with W6+ cations results in higher NO reduction activity with a slightly increase of selectivity toward dinitrogen formation. Doping with Ca2+ leads to higher catalytic activity for the reduction of NO, while the selectivity was found to decrease upon increasing calcium content. The above observations are explained by the theory of dopant induced metal support interactions (DIMSI). The mechanistic pathways of the above mentioned reaction over Rh/TiO2 catalysts were studied employing infrared (IR) and mass spectroscopy (MS). The results showed, that NO is molecularly absorbed on the Rh. In the presence of reduced Rh sites NO dissociation occurs, resulting in N and O adspecies. Recombination of N species results in the production of dinitrogen in the gas phase. N2O formation is correlated with the presence of the dinitrosyl complex species on the catalytic surface. Reaction of the latter with NO from the gas phase leads to N2O production. Regeneration of oxidized Rh sites is achieved via oxidation of propylene to acrolein. Further oxidation of the latter leads to the formation of carboxylates.

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Made available in DSpace on 2014-09-09T12:22:45Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) 69594.pdf: 1287197 bytes, checksum: 097f898f1364f075660a2a3257570c38 (MD5) Previous issue date: 2013 / Fundação Oswaldo Cruz. Instituto Nacional de Saúde da Mulher, da Criança e do Adolescente Fernandes Figueira. Departamento de Ensino. Programa de Pós-Graduação em Saúde da Criança e da Mulher. Rio de Janeiro, RJ, Brasil. / Objetivo: Identificar fatores de risco associados à necessidade de exsanguíneotransfusão (EXT) em gestações acometidas por doença hemolítica perinatal (DHPN) e avaliar a influência da terapêutica aplicada. Métodos: Foi realizado estudo de coorte e analisados 124 casos referentes a nascimentos de crianças com DHPN no período de abril de 2006 a junho de 2009, cujo parto ocorreu no Instituto Fernandes Figueira. Dados da história materna, pré-natal, parto e recém-nascido foram avaliados quanto a sua relação com a necessidade de transfusão intrauterina (TIU) e com o desfecho grave da doença, definido por EXT. Resultados: Paridade (RR:1,22; IC:1,00-1,49), história de filhos com doença (RR:3,21; IC:1,27-7,99) e hidropisia fetal (RR:1,86; IC:1,11-3,11) são fatores de risco importantes para a necessidade de TIU. Realização de TIU (RR:1,82; IC:1,12-2,97), parto normal (RR:0,53; IC:0,30-0,93), icterícia (RR:2,31; IC: 1,46-3,68), nível de hematócrito ao nascimento (RR:0,95; IC:0,93-0,98), bilirrubina total máxima durante a internação (RR:1,23; IC:1,16-1,31), tempo de fototerapia (RR:0,90; IC:0,85-0,95) e tempo total de internação (RR:097; IC:0,95-0,99), são variáveis que estabelecem relação independente e estatisticamente significativa com o desfecho de gravidade. A necessidade de EXT após TIU difere entre fetos menos graves (RR: 1,29; IC:0,94-1,77) e mais graves (RR: 1,61; IC:1,11-2,34). Conclusão: A identificação de fatores de risco é possível e importante para o cuidado do recém-nascido no período neonatal precoce acometido por DHPN. O impacto da terapêutica no desfecho neonatal varia de acordo com a gravidade no momento do diagnóstico. / Objective : To identify the major risk factors related to exchange transfusion (EXT) in pregnancies afflicted with hemolytic disease of the fetus and newborn (HDFN) and to evaluate the influence of applied therapy . Methods: A cohort study of 124 infants born with HDFN between A pril 2006 and June 2009 at the Fernandes Figuei ra National Institute . Data on maternal history, prenatal care, delivery and neonatal paramet ers were subjected to analysis to de termine their relationship with the need for i ntrauterine transfusion (IUT) du ring prenatal care and severe disease outcome, represented by EXT. Results: Parity (RR:1,22; C I :1,00 - 1,49) , obstetric history related to HDFN (RR:3,21; C I :1,27 - 7,99) and hydrops fetalis (RR:1,86; C I :1,11 - 3,11) are important risk factors related with the need for IUT. The need for IUT (RR:1,82; C I :1,12 - 2,97), vaginal delivery (RR:0,53; C I :0,30 - 0,93), jaundice (RR:2,31; C I : 1,46 - 3,68), hematocrit level at birth (RR:0,95; C I :0,93 - 0,98), peak serum bilirubin leve ls during hospitalization (RR:1,23; C I :1,16 - 1,31), duration of phototherapy (RR:0,90; CI:0,85 - 0,95) and total duration of hospital stay (RR:097; C I :0,95 - 0,99 ) were the variables found to establish an independent and statistically significant relationship w ith severe outcome. The need for EXT after IUT was different between fetus with less severe disease (RR: 1,29; C I :0,94 - 1,77) and more severe disease (RR: 1,61; C I :1,11 - 2,34). Conclusion: To identify risk factors is possible and important in early neonatal assistance of newborn afflicted with HDFN. The impact of therapy on the neonatal outcome depends on severity of the disease at the moment of diagnosis.

Made available in DSpace on 2016-06-02T19:55:36Z (GMT). No. of bitstreams: 1 5188.pdf: 6910424 bytes, checksum: 50b02c26311d2e058a7ac27b5419e05d (MD5) Previous issue date: 2011-06-08 / Environmental laws and stricter quality specifications have driven the development of technologies for improving the cetane number in diesel fuel. In addition to the saturation of (poly)aromatic compounds, responsible for limited gains, ring opening of at least one ring of (poly)cycloalkane, without loss of yield by cracking, is a promising strategy to maximize this property. Numerous studies have demonstrated the significant performance of Pt, Rh and Ir supported on zeolites for naphthenic ring opening in the hydroconversion of model compounds (naphthalene, tetralin and decalin). This study aimed to systematically assess the role of acid and hydrogenating functions for hydroconversion of decalin. It was also evaluated the effect of activation conditions (calcination and reduction), type of zeolite (Faujasite, FAU, or Beta, BEA), the content and type of metal (Pt, Ir or Rh). The influence of Pt-Ir and Pt-Rh bimetallic systems, as well as the inhibition by H2S, were studied in terms of the performance of these catalysts. For the catalytic precursors prepared, better activity and selectivity to ringopening products were obtained from calcination at 573 K and reduction at 713 K. This performance was consistent with a more homogeneous distribution of metallic particles on the support, and thus greater dispersion of the metallic phase. The reaction steps of ring contraction, ring opening and cracking were consecutive for the hydroconversion of decalin. It is noteworthy that the catalytic systems studied, under the operating conditions employed, yielded up to 45 mol% ring opening products and less than 15 mol% cracking products, at decalin conversions as high as 90 %. The Pt/BEA catalyst presented the best performance, thiotolerance (lower production of cracking products) and thioresistence (selectivity recovery after removal of H2S), followed by the Pt-It/BEA and Ir/BEA catalysts. This study allowed to highlight some peculiarities of the hydroconversion of decalin on noble metal/zeolite catalysts. Although decalin is a saturated molecule, his naphthenic character and probably the presence of a tertiary carbon in its structure, facilitates activation of the molecule directly on the strong acid sites of zeolite, even at relatively moderate temperatures. Thus, it is not necessary to form an olefin on a metal site and undergo subsequent protonation, as in a classical bifunctional mechanism, such as in hydroisomerization and hydrocracking of n-paraffins. However, the hydrogenation component of the catalyst influences the selectivity of the reaction, controlling the process of desorption/adsorption of any intermediate olefins formed. Greater hydrogenation activity implies lower availability of adsorbed carbocations that can be converted to cracking products. This proposition is consistent with the results obtained by varying the type and content of metal, support acidity and poisoning of the hydrogenation sites in the catalysts. / Legislações ambientais e especificações de qualidade mais restritivas têm impulsionado o desenvolvimento de tecnologias visando melhoria de cetano em óleo diesel. Adicionalmente à saturação de (poli)aromáticos, responsável por ganhos limitados, à abertura de pelo menos um anel do (poli)cicloalcano, sem perda de rendimento por craqueamento, consiste em estratégia potencial para maximização desta propriedade. Inúmeros trabalhos vêm demonstrando desempenho significante de catalisadores de Pt, Rh e Ir suportados em zeólitas para abertura de anel naftênico na hidroconversão de compostos-modelo (naftaleno, tetralina e decalina). O presente trabalho teve por objetivo avaliar sistematicamente o papel das funções ácidas e hidrogenantes para a hidroconversão de decalina. Foram abordados os efeitos das condições de ativação (calcinação e redução), do tipo de zeólita (Beta, BEA, ou Faujasita, FAU), do teor e do tipo de metal (Pt, Ir ou Rh). Também foi analisado o efeito de sistemas bimetálicos Pt-Ir e Pt-Rh, bem como a influência da inibição por H2S, no desempenho destes catalisadores. Para os precursores catalíticos preparados, melhores atividade e seletividade aos produtos de abertura de ciclo foram obtidas a partir da calcinação a 573 K e redução em 713 K. Este desempenho foi compatível com uma distribuição mais homogênea de partículas metálicas no suporte e, portanto, maior dispersão da fase metálica. As etapas reacionais de contração, abertura de ciclo e craqueamento são consecutivas para a hidroconversão de decalina. Destacam-se para os sistemas catalíticos estudados e condições operacionais empregadas, rendimentos de produtos de abertura de ciclo de até 45 %mol e craqueamento inferior a 15 %mol, obtidos para conversões de decalina tão elevadas quanto 90 %. O catalisador Pt/BEA apresentou melhores desempenho, tiotolerância (menor seletividade a craqueados na presença de H2S) e recuperação da seletividade após remoção do H2S, seguido pelo bimetálico de Pt-Ir/BEA e monometálico de Ir/BEA. O presente estudo permitiu colocar em evidência algumas peculiaridades da hidroconversão da decalina sobre catalisadores metal nobre/zeólita. Apesar de se tratar de uma molécula saturada, seu caráter naftênico e, provavelmente, a presença de um carbono terciário na sua estrutura, facilita a ativação da molécula diretamente sobre os sítios ácidos fortes da zeólita, mesmo em temperatura relativamente moderadas. Dessa forma, não necessita a formação de uma olefina num sítio metálico para posterior protonação, como num mecanismo bifuncional clássico de hidroisomerização e hidrocraqueamento de n-parafinas. A componente de hidrogenação do catalisador influencia, no entanto, a seletividade da reação, controlando o processo de dessorção/adsorção e hidrogenação das olefinas intermediárias formadas. Quanto maior a atividade hidrogenante, menor a disponibilidade de carbocátions adsorvidos que podem ser convertidos a produtos de craqueamento. Esta proposição é consistente com os resultados obtidos ao se variar o tipo e o teor de metal, a acidez do suporte e pelo envenenamento dos sítios de hidrogenação dos catalisadores.

Orientador: Lilian Maria de Castilho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-16T19:56:37Z (GMT). No. of bitstreams: 1 Amaral_DaphneRenataTavares_M.pdf: 1431812 bytes, checksum: 82f80c8b6c347220a22a8345ee9be187 (MD5) Previous issue date: 2010 / Resumo: A análise de plasma materno para a determinação do genótipo RHD fetal é uma importante ferramenta no acompanhamento de gestantes RhD-negativo, especialmente em pacientes aloimunizadas. Este trabalho verificou a acurácia da genotipagem RHD fetal pela análise do plasma materno em uma população do Brasil. Foram analisadas 88 gestantes RhD-negativo entre 11 e 39 semanas de gestação, com idade mediana de 28 anos. Treze (14,78%) pacientes encontravam-se aloimunizadas com anti-D. Foram utilizados primers e sondas para detecção do gene RHD (exons 4, 5 e 10) por PCR em tempo real. Como controle interno, utilizou-se um conjunto de primers e sondas para identificar o genes SRY e CCR5. Sangue periférico ou sangue de cordão umbilical dos respectivos neonatos foram coletados durante o parto para a realização da fenotipagem RhD. A genotipagem RHD convencional foi realizada em todas as 88 amostras de DNA materno. Oitenta e três (94,32%) gestantes apresentaram a deleção do gene RHD e em 5 (5,68%) amostras foram identificadas variantes do gene RHD (3 RHD e 2 DFR). A genotipagem RHD convencional foi também realizada em 17 amostras de DNA paternas. Quinze amostras (88,24%) foram genotipadas como RHD+ (5 RHD+/RHD+ e 10 RHD+/RHD-) e 2 (11,76%), como RHD-. Cinqüenta e oito (65,91%) fetos foram genotipados como RHD+. Vinte e sete (30,68%) amostras apresentaram ausência completa do gene RHD e três fetos apresentaram amplificação apenas para o exon 10, demonstrando a presença de uma possível variante RHD ou RHD-CE-Ds. Todos os resultados da genotipagem RHD fetal foram concordantes com a fenotipagem neonatal incluindo os 3 fetos com a variante RHD, fenotipados como RhD-. Nossos resultados indicam que a genotipagem RHD fetal através da análise do plasma materno amplificando 3 regiões do gene RHD (exons 4, 5 e 10) é adequada para a aplicação clínica. Este protocolo pode-se tornar prática em um futuro próximo / Abstract: Maternal plasma analysis for determination of the fetal RHD status is an important tool for the management of RhD-negative pregnant, specially alloimunized women. We assessed the accuracy of fetal RHD genotyping by analysis of maternal plasma in a multi-ethnic population. We analyzed plasma samples from 88 RhD-negative pregnant women between 11 and 39 weeks of gestation, median age of 28 years old to determine the fetal RHD genotype. This population was from Southeastern Brazil with high mixed ethnic background. Thirteen patients (14,78%) had anti-D alloantibody. We used TaqMan primers and probes to detect exons 4, 5 and 10 of RHD, by real-time PCR. As internal controls, we used primers/probes sets to SRY and CCR5. Peripheral or umbilical cord bloods from respective neonates were collected during delivery and hemagglutination was performed. Conventional RHD genotyping was realized in all pregnant. Eighty-three patients had a deletion of RHD gene and five samples were identified RHD variants (3 RHD and 2 DFR). The conventional RHD genotyping was also performed on 17 DNA samples from fathers. Fifteen samples were genotyped as RHD+ (5 RHD+/RHD+ and 10 RHD+/RHD-) and 2 RHD-negative. Fifty-eight (65,91%) fetuses were genotyped as RHD+. Twenty-seven (30,68%) samples showed completely absence of RHD and three fetuses showed amplification only for the exon 10, demonstrating the presence of a possible variant (RHD or RHD-CE-Ds). All fetal RHD results agreed with the neonatal typing including the 3 fetuses with RHD variant, phenotyped as RhD-negative. Thus, the accuracy of the fetal RHD genotyping in this population was 100%. The earliest pregnancy in which fetal RHD was detected was 11 weeks. Our findings indicate that the accuracy of fetal RHD genotyping from maternal plasma using 3 regions (exons 4, 5 and 10) can be sufficient for clinical application in a multi-ethnic population. This knowledge helped us on the development of a feasible protocol for fetal RHD genotyping on DNA from maternal plasma in our population and should become practice in the near future / Mestrado / Ciencias Basicas / Mestre em Clinica Medica

O desenvolvimento industrial e urbano tem causado aumento mundial das emissões de poluentes atmosféricos. Nas áreas metropolitanas o problema da deterioração da qualidade do ar tem se constituído numa das mais graves ameaças à qualidade de vida dos seus habitantes e os veículos automotores contribuem diretamente com o aumento do material particulado (MP). Neste trabalho foram descritas as etapas metodológicas para validar a Tibouchina granulosa como biomonitor ambiental. Assim, foram abordados a caracterização das folhas, categorização do MP, protocolo de remoção de MP e determinação dos EGPs (Pd, Pt e Rh) na deposição seca das folhas. Para tanto foram realizadas quatro coletas anuais (2011-2014) de folhas, entre os meses de agosto e setembro, em pontos específicos. Os resultados da caracterização mostraram que as folhas permanecem residentes nos ramos por até 6 meses e ocorre o desenvolvimento duas novas folhas por nó a cada mês, indicando que o biomonitoramento pode ser realizado com distribuição temporal e espacial. Os caracteres anatômicos foliares mais relevantes são os tricomas, sendo caracterizados quatro tipos (glandular, adpresso-escabro, base ramificada e estrigoso) que adsorvem o MP. No protocolo de remoção da deposição seca, o número de MP variou de acordo com os diferentes reagentes analíticos utilizados, sendo os mais significativos o ALCONOX&reg e a água régia, que apresentaram valores de remoção na faixa de 99-98% e de 94-99%. As estimativas das incertezas analíticas dos EGPs apresentam valores de uCPt=5% (Pt), uCPd=12% (Pd) e uCRh=5% (Rh) e as incertezas de amostragem, os valores de 57% para o Pd, 24% para a Pt e 27% para o Rh. Portanto, a incerteza expandida foi da Pt U=48%, Pd U=86% e Rh U=9%, a incerteza do Rh apresentou valor mais baixo por ser o elemento minoritário. A elevada sensibilidade do método para determinação dos EGPs apresentou limite de detecção de 0,1 pg g-1 para o Pd, 1,3 pg g-1 para Pt e 0,3 pg g-1 para o Rh e acompanhada boa reprodutibilidade. As concentrações dos EGPs encontradas na deposição seca nos vários pontos de coletas indicaram a clara diferença de acúmulo destes elementos entre o ponto de referência e os locais impactados, sugerindo que a liberação dos EGPS pelos catalisadores veiculares pode ser considerada alta. A evidência da presença dos EGPs na deposição seca foi confirmada por meio da análise da distribuição, que mostrou claramente a similaridade com o material de referência certificado Used Auto Catalystc-2557. As distribuições espaciais dos EGPs foram semelhantes para a Coleta 2, indicando os hot points da RMSP. As concentrações do EGPs foram ordenadas em Pt>Pd>Rh e foram mais baixas no ponto de coleta para controle das amostragens em comparação com os outros locais amostrados. Pode ser concluído que as folhas de T. granulosa foram validadas como biomonitor passivo dos EGPs constituintes de catalisadores veiculares. / Industrial and urban development has caused worldwide increase in emissions air pollutants. In metropolitan areas, the problem of deterioration air quality has been one the most serious threats to quality life its inhabitants, motor vehicles contribute directly increase pollutants. This work describes the methodological steps to validate Tibouchina granulosa as environmental biomonitor, which involved the characterization the leaves, PM categorization, PM removal protocol and determination PGEs in dry deposition, for which four annual collections (2011-2014) were performed between August and September of each year. The of results leaf characters showed that leaves in the branches remain for up to 6 months and the development two new leaf occurs every month. The most relevant foliar characters anatomical are trichomes, being characterized five types. The highest particle concentrations adsorbed to stray trichomes and star-based trichomes. In dry deposition removal protocol, MP number varied according to different analytical reagents used, the most significant being ALCONOX&reg and aqua regia, which presented range removal values of 99-98% and 94-99%, respectively. The estimates analytical uncertainties PGEs show de uCPt=5% (Pt), uCPd=12% (Pd) e uCRh=5% (Rh) and sampling uncertainties values were 57% (Pd), 24% (Pt) and 27% (Rh). Therefore, the expanded uncertainty was Pt u=48%, Pd u=86% e Rh u=9%, in case Rh the uncertainties should be reevaluated by presenting minority values. The high sensitivity of the method for determination of PGEs showed a detection limit of 0.1 pg g-1 for Pd, 1.3 pg g-1 for Pt and 0.3 pg g-1 for Rh and good reproducibility of the results. The concentrations PGEs found in dry deposition in various collection points indicated the clear difference accumulation these elements between reference point and impacted sites, suggesting that release PGEs by the vehicle catalysts can be considered high. Confirming this evidence, through the ternary graphs, which clearly showed similar distributions in the environmental samples and equality with MRC (Used Auto Catalysts). The spatial distributions of Pt, Pd and Rh are similar for Collection 2. Concentrations of the PGEs were ordered in Pt>Pd>Rh and were lower at the collection points for control samplings compared to other sites sampled. In view of the above, it can be concluded that the leaves of T. granulosa can be used as environmental biomonitor of vehicular emissions of PGEs constituent of vehicular catalysts.

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal. / New economic realities are putting pressure on HR to widen its focus from the administrative role it has traditionally played, to a broader strategic role as a business partner. This transition has been difficult for many HR functions because in order to play a more strategic role, they have to measure their effectiveness. To date very few have met this challenge. There are many schools of thought on measuring the effectiveness of the HR function. Sorne authors propose a quantitative or a qualitative approach, while others propose a global approach. However, they all have limitations. An alternative approach is the Balanced Scorecard concept, which enables organizations to translate their strategy into a balanced set of metrics, combining qualitative and quantitative, and financial and non­financial metrics, helping the organization assess current and predict future performance. Therefore, the objective of this research has been to design a balanced scorecard for the Human Resources function as a potential approach to evaluating its effectiveness. Based on the literature, the research methodology focused on the design of a scorecard for a large international organization. First, the HR strategy for this organization was clarified and articulated into a series of cause and effect relationships, presented as tangible goals. To assess the performance of these strategic goals, measures were then selected and defined for each one, resulting in a feasible scorecard composed of 3 8 metrics. The scorecard is ready to implement as a strategic measurement system, enabling the Function' s effectiveness to be assessed over time. Due to the exploratory nature of this research, this application study will hopefully provide insight on the use of the balanced scorecard as an approach to evaluating the effectiveness of the HR function. In the current context facing HR functions, it is key that they find a way to evaluate their effectiveness that will support their evolution as business partners. / Les réalités économiques étant ce qu'elles sont, une forte pression est exercée sur la fonction ressources humaines (RH) afin d'élargir son horizon du rôle administratif traditionnel, à un rôle stratégique accru en tant que partenaire d'affaires. Cette transition a été difficile pour les fonctions RH car, afin d'assumer un rôle plus stratégique, elles se doivent de mesurer leur efficacité. À ce jour, très peu d'entre elles ont relevé ce défi. Il y a plusieurs écoles de pensées sur le sujet de la mesure de l'efficacité du rôle des RH. Certaines proposent une approche quantitative ou qualitative, alors que d'autres suggèrent une approche globale. Cependant, toutes ces approches accusent certaines limites. Le concept du Tableau de Bord Équilibré est une approche qui permet aux organisations de mettre sur pied leurs stratégies sous forme de mesures équilibrées, combinant mesures qualitatives et quantitatives, financières et non-financières, permettant ainsi à ces organisations d'évaluer les performances actuelles et d'anticiper les performances futures. En résumé, l'objectif de ce travail a été de concevoir un tableau de bord équilibré comme une approche susceptible de mesurer l'efficacité de la Fonction des Ressources Humaines. Basée sur la documentation existante, la méthodologie de recherche se concentre sur la création type d'un tableau de bord pour une organisation de taille internationale. D'abord, la stratégie des RH pour cette organisation a été exprimée et conçue en séries de relations de cause à effet, présentées sous forme d'objectifs tangibles. Pour évaluer la performance de ces objectifs stratégiques, des mesures précises furent sélectionnées et définies donnant comme résultat un tableau de bord réalisable composé de 38 mesures. Le tableau de bord est donc prêt à être mis en œuvre en tant que système de mesure stratégique, permettant ainsi d'évaluer l'efficacité de la Fonction au fil du temps. Ce travail étant de nature exploratoire, il est à prévoir que cette étude d'application fournira un modèle quand à l'utilisation du tableau de bord en tant que méthode d'évaluation de l'efficacité de la fonction RH. Face au contexte actuel, il est essentiel que les fonctions RH trouvent un moyen d'évaluer leur efficacité afin de supporter leur évolution en tant que partenaire d'affaires.

The properties of transition metal clusters differ from those of both atomic and bulk size regimes. Such clusters are incompletely understood and potentially useful, making them attractive targets for further study. The very smallest clusters studied in this thesis (CuO, Cu₂ and Cu₃) have been investigated with velocity map imaging. 1+1' photodissociation of CuO X ²Π_3/2 was observed, via the C, D, E, F and H states of CuO. CuO* was photodissociated to form Cu(²D_3/2) + O(¹D₂). D₀(CuO) was determined to be 3.041±0.030 cm^-1. Non-resonant three-photon Cu₂ photodissociation occurred throughout the energy range studied to produce one ground-state and one highly-excited copper atom,Cu*. Cu* was ionised by a single additional visible photon. Nearly all Cu* atoms with internal energies between 41000 and 53000 cm^-1 were observed. D₀(Cu₂) has been calculated to be 1.992±0.037 eV. Features arising from photodissociation of Cu₃ were observed in the Cu^+ and Cu₂^+ ion yield spectra and images. Their structure was ill-resolved due to uncertainties in the internal energy of both parent Cu₃ and product Cu₂. These features correspond to single-photon dissociation of Cu₃ to produce metastable D-states of the copper atom and vibrationally excited Cu₂. One series of features implies a previously-unobserved state of either Cu₂ or Cu₃. Rh_nN₂O^+ and Rh_nON₂O^+ (n=5, 6) were collisionally activated in collision-induced dissociation (CID) experiments with Ar and ¹³CO. These experiments were carried out in a Fourier Transform Ion Cyclotron Resonance(FT-ICR)spectrometer. Argon collisions induced both N₂O desorption and N₂O reduction. The branching ratios observed reproduced those seen in prior IR-MPD experiments. ¹³CO was observed to chemisorb to the cluster upon collision, activating not only N₂O desorption and reduction but also CO oxidation. Formation of CO2 was noted to be particularly rapid on the n=5 cluster compared to the n=6 cluster. Reactions of Rh_nN₂O^+ (n=4-6) clusters were also activated by black body radiation. This technique is known as BIRD - black-body induced infrared radiative dissociation. These studies revealed that the N₂O desorption barrier exceeds the N₂O reduction barrier on all clusters studied, but that the entropic favourability of desorption increases its rate relative to reduction with increasing cluster internal energy. The BIRD rate was much reduced upon cooling the ICR cell to 100 K. A further test of the BIRD mechanism increased the number of N₂O ligands and hence the absorption rate. An approximately linear increase in the dissociation rate of Rh_n(N₂O)_m^+ was observed with index m. Deviations from linearity were caused by variations in the N₂O desorption rate. In the case of Rh₅(N₂O)_m^+, desorption rates corresponded closely to N₂O binding energies calculated by density functional theory. The system was modelled using a master equation approach.

Orientador: Maria Elisabete Jorge Amaral / Banca: Herminone Elly Melara de Campos Bicudo / Banca: Luciana Correia de Almeida Regitano / Banca: Eliana Morielle Versute / Banca: Artur Luiza da Costa da Silva / Resumo: O cromossomo 1 do genoma bubalino (BBU1), o maior cromossomo do cariótipo do búfalo de rio, é um cromossomo submetacêntrico que possui homologia com os cromossomos 1 e 27 do genoma bovino. Neste trabalho, apresentamos o primeiro mapa RH para este cromossomo, construído por meio da utilização de um painel de células somáticas híbridas irradiadas búfalo-roedor, denominado BBURH5000. O mapa consistiu em 69 marcadores derivados dos cromossomos bovinos BTA1 e BTA27, incluindo 48 genes codificantes, 17 microssatélites e quatro ESTs distribuídos em dois grupos de ligação. A freqüência de retenção observada entre os marcadores variou de 17.8% a 52.2%. A ordem dos marcadores dentro dos grupos de ligação foi, em sua maioria, idêntica a ordem encontrada nos mapas RH e de seqüência do genoma bovino. A análise comparativa do mapa RH obtido para BBU1 com o genoma humano revelou oito blocos homólogos de sintenia entre BBU1 e segmentos correspondentes dos cromossomos humanos 3, 4, 8 e 21, sendo a maioria deles rearranjados quanto à ordem dos genes e orientação dos blocos. Os blocos de sintenia também foram comparados com os genomas de outras espécies de mamíferos, como boi, chimpanzé, cachorro e cavalo. Considerando a inexistência de mapas de ligação para o búfalo de rio, o mapa RH obtido neste estudo fornece dados essenciais para os estudos comparativos deste cromossomo com qualquer outra espécie de mamífero. / Abstract: The largest chromosome in the river buffalo karyotype, BBU1, is a submetacentric chromosome with reported homology between BBU1q and bovine chromosome 1 and between BBU1p and BTA27. We present the first radiation hybrid map of this chromosome containing 69 cattle derived markers including 48 coding genes, 17 microsatellites and four ESTs distributed in two linkage groups. The RH map was constructed based on the analysis of a recently developed river buffalo-hamster whole genome radiation hybrid panel (BBURH5000). The retention frequency of individual markers across the panel ranged from 17.8% to 52.2%. With few exceptions, the order of markers within linkage groups is identical to the order established for corresponding cattle sequence and RH maps. Comparative analysis between BBU1-RH5000 and the human genome revealed eight homologous synteny blocks corresponding to HSA3q, HSA4q, HSA8p and HSA21q. Most of the blocks showed rearrangements in the gene order and in the orientation of the synteny blocks. The synteny blocks were also compared with other mammalian genomes, such as bovine, chimpanzee, dog and horse. Considering that a genetic linkage map does not exist for river buffalo, the radiation hybrid map generated in this study provides valuable data for comparative mapping of BBU1 chromosome. / Doutor