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Des catalyseurs à base de carbure de molybdène ont été étudiés pour la réaction de reformage du méthane par le CO2 (RMC) et pour la réaction de synthèse Fischer-Tropch (SFT). Pour la réaction de RMC, différentes teneurs de Ni en tant que promoteur ont été ajoutées aux catalyseurs Mo2C/Al2O3. Les résultats indiquent que le nickel augmente l'activité et la stabilité des catalyseurs Mo2C/Al2O3. L'addition de nickel provoque la re-carburation des espèces Mo oxycarbonées à des espèces carbonées et conduit à l'augmentation rapide de l'activité lors de la réaction. Les différentes méthodes de préparation ont également une influence notable.Pour la réaction de SFT, différents supports, mais aussi différents promoteurs, ont été étudiés. Les résultats suggèrent que l’alumine procure une très haute sélectivité vis-à-vis des oléfines légères. L'augmentation de la teneur en potassium diminue les activités d’hydrogénation de CO et inhibe également les réactions de gaz à l'eau. Cependant, il est évident qu'elle augmente la selectivité des chaînes oléfines et les propriétés de croissance des chaines carbonée. Enfin, la réaction RMC sous pression et la réaction de SFT en présence de CH4 ou de CO2 ont été étudiées. Les résultats montrent que l’augmentation de la pression conduit à un fort dépôt de carbone sur les catalyseurs à base de carbure de NiMo et l'addition de CH4 ou du CO2 dans le gaz de synthèse lors de la SFT, contribue à diminuer l'activité d'hydrogénation du CO et influe sur la distribution des produits. / Molybdenum carbide catalysts have been studied in dry methane reforming (DMR) and in Fischer-Tropsch synthesis (FTS). For the DMR reaction, For the DMR, different contents of Ni promoted Mo2C/Al2O3 catalysts were investigated. The results indicated nickel increased the activity and stability of Mo2C/Al2O3 catalysts. The addition of nickel promoted the re-carburization of Mo species from oxycarbide to carbides species and led to the rapid increase of activity during reaction. The different preparation methods also had a significant influence on the nickel promoted Mo2C/Al2O3 catalysts. For FTS, different supports and different promoters have been investigated for the Mo2C based catalysts. The results suggested that alumina supported catalyst exhibited higher light olefins selectivity. Increasing the potassium contents lead to a decreased in t CO hydrogenation activities and also inhibited the water gas shift reaction. However, it obviously increased the olefins selectivity and carbon chain growth properties. At last, DMR under pressure and FTS in the presence of CH4 or CO2 were investigated. The results showed that an increase in pressure led to high carbon deposition over the catalyst surface and the addition of CH4 and CO2 in the syngas decreased the CO hydrogenation activity and affect the products distribution.

Dans le contexte énergétique actuel, de nouvelles filières de production d’énergies renouvelables sont encouragées. En Europe, la méthanisation est une alternative très utilisée car elle produit du biogaz composé de CH4 et de CO2. Le reformage de ce biogaz pourrait conduire à la consommation des deux plus importants gaz à effet de serre, pour la production de syngaz (H2, CO) utilisé en synthèse Fischer-Tropsch, et édifiant une technologie waste-to-liquids. Un des principaux verrous de cette réaction est la présence de soufre comme impureté dans le biogaz, qui empoisonnent les catalyseurs utilisés.Ainsi, une série de catalyseurs à base de molybdène a été synthétisée et testée en reformage à sec du méthane. L’influence de plusieurs paramètres a été testée, tels que (i) la charge en molybdène (ii) l’influence de promoteurs (Ni, Co, CeO2, MgO) ou (iii) l’utilisation de différents supports (Al2O3, ZrO2, Carbone, SiO2, MgO). Les catalyseurs ont été analysés au moyen de différentes caractérisations physico-chimiques afin de mettre en évidence des relations structure/activité, d’identifier les causes de désactivation possibles et de conclure sur la formulation la plus stable en présence d’H2S lors des tests catalytiques. / In the worldwide current energy situation, new pathways for renewable energy production are developed. In Europe, methanisation is an alternate way widely implemented since it produces biogas that contains CH4 and CO2. The reforming of this biogas could lead to the consumption of the two main greenhouse gases for the production of syngas (H2, CO), which could be industrially attractive for the Fischer-Tropsch process, eventually setting up a promising waste-to-liquids technology. Yet, the main hurdle regarding this reaction is the presence of sulfur in the biogas which poisons the catalysts.Thus, a set of molybdenum-based catalysts has been synthesized and tested for the dry reforming of methane. The influence of several parameters has been evaluated, such as (i) molybdenum loading, (ii) the addition of promoters (Ni, Co, CeO2 and MgO) or (iii) the use of different supports (Al2O3, ZrO2, Carbone, SiO2, MgO). The catalysts have been analyzed via several characterization techniques to establish structure/activity relationships, identify the main deactivation phenomena and conclude on the most stable and active composition in presence of H2S during the catalytic runs.

La société est préoccupée par l’effet de serre et la nécessité de développer des procédés alternatifs et durables pour fabriquer les produits actuellement dérivés du pétrole. La valorisation du CH4 avec CO2 (reformage sec) présente l’avantage de consommer des gaz qui contribuent fortement à l’effet de serre. La réaction produit de l’H2 et du CO qui, séparément ou ensemble, sont à la base de différents procédés de production d’énergie et de molécules plateformes. Des catalyseurs du type Ni-Ce-O et Ni-Mg-Al-O, performants pour la production de gaz de synthèse à partir de méthane et de dioxyde de carbone, ont été développés. L’influence de différents paramètres a été étudiée, comme la teneur en Ni et la température de réaction (600°C-800°C). Les principales difficultés rencontrées sont la formation de coke conduisant à la désactivation rapide des catalyseurs à cause des températures élevées de fonctionnement et la présence simultanée de CO2 et d'hydrogène qui conduit, par la réaction inverse du gaz à l'eau, à une perte en sélectivité. Afin d’éviter ce type de problématique un nouveau procédé a été développé. Il implique d’alimenter de manière alternée chacun des réactifs et fait intervenir un solide agissant en tant que vecteur d’oxygène. Dans un premier temps le solide réagit avec le méthane pour former le monoxyde de carbone et le dihydrogène. Le solide étant régénéré à chaque cycle, la déactivation par cokage est évitée. L’activité et la sélectivité du solide est assurée par la présence d’un oxyde réductible (CeO2) faisant office de vecteur d’oxygène, et d’un métal (Ni, Co), non-oxydable dans les conditions de réalisation du procédé, qui assure l’activation du méthane. / Nowadays the society is concerned about the greenhouse effect, and the necessity to find alternative procedures and more sustainable and durable processes to obtain the products made from petroleum. The valorization of CH4 with CO2 (dry reforming) brings the advantage of consuming gases which contribute strongly to the greenhouse effect. This reaction produces H2 and CO, which jointly or separately, are the raw materials for different processes producing energy and chemicals.Ni-Ce-O and Ni-Mg-Al-O based catalysts were successfully prepared. The influence of different parameters was studied, such as the Ni loading and the reaction temperature (600°C-800°C). The main difficulties are the formation of coke leading to rapid catalyst deactivation due to the high operating temperatures and the simultaneous presence of CO2 (reactant) and hydrogen (product) which leads, by the reverse water gas shift (RWGS), to a loss in selectivity. A process which can avoid this kind of problematics consists in exposing alternately each of the reactants. Initially the solid acts as oxygen carrier reacting with methane to form carbon monoxide (1 mole) and hydrogen (2 moles). As the solid is regenerated at each cycle, the deactivation by carbon deposition is avoided. The activity and selectivity of the solid is provided by the presence of a reducible oxide (CeO2) and a metal (Ni, Co), which cannot be reoxidized under the experimental conditions ensuring the activation of methane. Different physicochemical characterizations were performed on catalysts to find correlations between the catalytic activity and properties of the solids.

The disorders of the lipid metabolism have to be monitored for a number of socially significant diseases. For the diagnosis of these disorders, it turned out in the last 10 years as very beneficial to determine the particle size of the individual lipoprotein classes, in particular the low-density lipoprotein. Among several known methods, we have chosen gel filtration with the light scattering detector. Lipoprotein fractions were separated by ultracentrifugation from the plasma of four donors. Three biochemical parameters - total cholesterol, triacylglycerol, and total protein - were routinely determined for plasma and for each fraction. The silica column BioBasic SEC 300x7,8 mm was calibrated by the proteins thyroglobulin, ovalbumin and angiotensin II with UV detection (280 nm). These proteins are not suitable (due to the size) for the calibration method SEC-LLSD. Therefore, latex beads of various modifications and sizes were tested. The only usable measurement was obtained for the deep-blue latex beads of the size 55 nm, the others remained retained in the column. The lipoprotein fractions of VLDL and LDL were examined by the SEC-LLSD method at different pH (7.3, 7.5, 7.7, 8.0) and ionic strength (0.1M phosphate buffer, 0.1M phosphate buffer and 0.9% NaCl, 0.05M phosphate buffer and 0.9% NaCl)....

Sequential Equivalence checking has been and still is a challenging problem. Verifying two circuits that are structurally different but logically the same is very important and has many applications. Critical to the success of sequential equivalence checking is the determination of a sufficient portion of illegal states such that the two designs are equivalent outside of the illegal states. This work proposes a low-cost method to discover a subset of the illegal state space of a circuit by simulating and grouping some state variables to determine if any missing patterns are present. This thesis discusses the selection of simulated inputs, the grouping of flip-flops and what the missing patterns represent. Then all missing patterns are considered which are illegal state cubes and represent and compact them using BDDs. A BDD implementation was created to compact these illegal states more efficiently. Discussion is then done on the parameters of the BDD implementation design which can be used more efficiently given the situation. These illegal state cubes are considered to be implications which can be used to constrain a SAT solver. Results are then presented which show how effective these constraints are to proving equivalency using the SAT solver. Finally, the future work is discussed of discovering the illegal state space either faster or more completely. / Master of Science

Orientador: Maria de Lourdes Ortiz Gandini Baldan / Banca: Donaldo Schuler / Banca: Marcos Antonio Siscar / Banca: Adalberto Luis Vicente / Banca: Antonio Donizeti Pires / Resumo: Este trabalho tem por objetivo analisar o poema A Máquina do Mundo Repensada de Haroldo de Campos, sob a perspectiva da abordagem sincrônica da literatura. O poema em questão é um espaço dialógico por excelência. Nele, história e utopia, ciência e religião apresentam-se inexoravelmente ligadas pela linguagem (em ação) do poema-palimpsesto: máquina cuja engrenagem procura instituir convergências entre as diversas áreas do conhecimento, rompendo fronteiras por meio da articulação entre o pensamento poético e outras formas de pensamento. A tese está dividida em três partes. Na primeira parte, são feitos comentários sobre a tópica da máquina do mundo e seu caráter alegórico. Em seguida, apresenta-se uma leitura analítica do poema. Esta parte está dividida em três capítulos, cada um correspondendo à análise de um dos três cantos do poema, os quais revelam, segundo a perspectiva de leitura aqui adotada, o caminho do poeta que repensa o mundo, a partir do ritual poéticoantropofágico que realiza com as obras de outros "pensadores do mundo". Na última parte, apresenta-se uma discussão teórica sobre poesia e pensamento, em que são retomados aspectos mencionados ao longo da leitura do poema, vinculando-os ao estado das artes da poesia haroldiana. / Abstract: The aim of this work is to analyze the poem A Máquina do Mundo Repensada de Haroldo de Campos, by synchronic perspective of literature approach. This poem is a dialogical space, by excellence. In it, history and utopia, science and religion are closely related by the language in action that organizes the poem-palimpsest: machine which engines constructs convergences between the different areas, above mentioned, and poetry, broking frontiers by the articulation of poetic thought and other ways of knowledge. The thesis is divided in three parts. At the first part, commentaries of the world machine are presented in relation to its allegorical character. Then, at the second part, there is an analytical reading of the whole poem. This part is divided in three chapters, each one corresponding to one of the three parts of the poem, which reveals, since the perspective here adopted, the way followed by the poet that thinks about the world, using his poetic words and an "anthropophagical ritual" with other poets that has thought about the world. At the last part, there is a theory discussion about the relations between poetry and thought, in which, the aspects that has been analyzed in the poem reading are retaking to show the state of arts of haroldian poetry. / Doutor

Dissertação (Mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão. / Made available in DSpace on 2012-10-18T21:36:59Z (GMT). No. of bitstreams: 0Bitstream added on 2016-01-09T02:04:32Z : No. of bitstreams: 1 143510.pdf: 2312944 bytes, checksum: fb222dc8173aa48315ad6c10f875bb42 (MD5)

On December 11, 2008, the financial world was in a panic as the United States Securities and Exchange Commission (SEC) announced the arrest of Bernard L. Madoff of Bernard L. Madoff Investment Securities, LLC, for orchestrating a $65 billion Ponzi scheme. An investigation took place into Madoff's practices, and as a result, it was revealed the SEC failed to catch Madoff years earlier as a result of its business practices. After this became known, the SEC faced reputational harm. This qualitative analysis seeks to discover through identification and analysis of themes and sub-themes of response strategies, the extent to which the SEC applied Situational Crisis Communication Theory (SCCT) in its crisis response, in order to examine SCCT's merit as a theory in government crisis communication research. This study also offers additional response strategies imposed by the SEC to suggest further expansion of SCCT in a government context. / Master of Arts / On December 11, 2008, Bernard L. Madoff, of Bernard L. Madoff Investment Securities, LLC, was charged by the United States Securities and Exchange Commission (SEC) for his role in a $65 billion fraudulent scheme. During an investigation into Madoff’s business practices, it was revealed that the SEC overlooked many red flags that could have caught Madoff years earlier. As a result, the SEC faced reputational harm. This study examined the SEC’s crisis response to the public following the news of Madoff’s arrest by applying a crisis communication theory to discover “best practices” for government agencies when dealing with a preventable crisis. This study also offers suggestions to further expand crisis communication research and crisis response strategies in a government communication setting.

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