Os eletrocatalisadores PtRh/C foram preparados nas seguintes proporções atômicas: (100,0), (0,100), (90,10), (70,30) e (50,50). Os métodos empregados nas sínteses foram redução via borohidreto de sódio e redução por álcool. Os sais metálicos empregados foram H2PtCl6.6H2O e (RhNO3)3 e o suporte de carbono utilizado foi carbon Vulcan XC72, a composição metálica em massa foi de 20%; e o suporte, 80%. Os eletrocatalisadores foram caracterizados por técnicas físico-químicas, espectroeletroquímica e por experimento em célula a combustível, cujo emprego se deu por uma célula unitária direta a álcool com membrana alcalina. Os eletrodos de trabalho foram preparados pela técnica de camada fina porosa. A técnica de difração de raios X permitiu verificar ligas metálicas, fases segregadas e calcular a porcentagem de ligas metálicas, bem como constatar os tipos de fases cristalinas. A técnica de espectroscopia no infravermelho permitiu verificar que a oxidação eletroquímica do etanol se dá pelo mecanismo indireto de oxidação, ou seja, para todos materiais estudados houve a produção de espécies intermediárias, em que PtRh(70:30)/C sintetizado pelo médodo de redução via borohidreto de sódio produziu grandes quantidades de CO2 e C2H4O. Rh/C mostrou-se ativo eletroquimicamente para ambos os métodos de síntese empregados. A técnica de microscopia eletrônica de transmissão permitiu calcular o tamanho médio e a área superficial média dos eletrocatalisadores. As técnicas eletroquímicas permitiram verificar a estabilidade, potencial onset e pares redox dos sistemas considerados. / PtRh/C were prepared by the following atomic proportions: (100,0), (0,100), (90,10), (70,30) and (50,50). The methods employed in the synthesis of these materials were reduction by sodium borohydride and reduction by alcohol. The metal salts used were H2PtCl6.6H2O and (RhNO3)3, the support used was Carbon black XC72 and the bulk metal composition was 20% and 80% of support. The electrocatalysts were characterized by Energy Dispersive X-ray spectroscopy, X-ray diffraction and Transmission electron microscopy. The ethanol electrochemical oxidation mechanism was investigated by in situ Fourier Transform Infrared Spectroscopy couple to an Attenuated Total Reflection technique. The electrocatalytic activity were evaluated by Cyclic Voltammetry, Linear Sweep Voltammetry and Chronoamperometry techniques. The Fuel Cells tests were made in a single direct alcohol fuel cell with alkaline membrane. The working electrodes were prepared by a thin porous coating technique. X-ray diffraction allowed us to verify metallic alloys, segregate phases and to calculate the percentage of metallic alloys. It was else possible to identify crystallographic phases. Infrared Spectroscopy allowed us to verify that the electrochemical oxidation of ethanol was carried out by an incomplete mechanism. PtRh(70:30)/C prepared by sodium borohydride produced large amounts of carbon dioxide and acetaldehyde. Rh/C showed electrocatalytic activity when compared with other materials studied.

Pour contrôler les systèmes chimiques complexes, les outils de la chimie supramoléculaire s’avèrent puissants et représenteront certainement une des technologies clef du 21e siècle. En effet, la réversibilité intrinsèque des liaisons chimiques impliquées dans la formation d'assemblages supramoléculaires apporte à ces systèmes un caractère "adaptatif", capable de réorganiser leur structure en fonction des conditions environnementales. Ce comportement s’avère totalement inédit malgré le grand nombre d’études effectuées sur cette famille de molécules du fait de ses propriétés photoactives. Au cours des dernières années, notre groupe a synthétisé de nombreux dérivés de triarylamines (TAAs), qui ont été utilisés pour produire des architectures supramoléculaires multifonctionnelles. En fonction des différents groupements qui substituent ce coeur TAA, diverses morphologies ont pu être observées et les propriétés physiques de ces auto-assemblages produits dans des solvants non polaires tels que les solvants chlorés ou le toluène se sont également révélées variées (propriétés cristal-liquide, conductrices, plasmoniques...). A partir de ces travaux, mon projet de thèse consistait en deux objectifs: a) étudier l'auto-assemblage et les propriétés de ces composés TAA dans des solvants polaires comme l'eau ou le méthanol. Pour cela, comme tenu du caractère hydrophobe des TAAs, il s'avérait nécessaire de synthétiser de nouvelles molécules incorporant des groupements latéraux favorisant la solubilité dans de tels solvants; b) stabiliser les auto-assemblages de triarylamine par polymérisation covalente et étudier les propriétés physiques associées à ces nouvelles structures. Pour cela, il convenait de synthétiser de nouvelles molécules incorporant des groupements polymérisables sur les chaines latérales, qui n'influençaient pas les propriétés d'auto-assemblages des TAAs. [...] / Based on the unique directionality and reversibility of non-covalent interactions, supramolecular self-assembly works as an elegant methodology to construct multifunctional hierarchical architectures. Inspired by nature, where water provides a vital environment for biological process such as biomacromolecular folding, water-soluble supramolecular polymers have been prepared and studied so as to mimic related biological systems. On the other hand, owing to the dynamic nature of their non-covalent bonds, supramolecular polymers often lack mechanical robustness. Thus, cross-linking strategies have been developed in order to combine highly ordered molecular arrangement inherent to the sef-assembly and mechanical robustness of the covalent backbone, which might bee promising to reach functional materials for practical applications. In this thesis, we focus on well-designed triarylamine molecules which are known to self-assemble into supramolecular polymers with excellent physical properties, as discovered by our group. In particular, molecules studied in this manuscript are based on tris-amide triarylamine scaffold known to produce self-assemblies with metallic conductivity and self-healing behavior. First, we studied the self-assemblies of three novel tris-amide triarylamine derivatives decorated with either poly(ethylene glycol) (PEG), peptide or cyanine dyes side chains on the three amide positions in polar solvents, i.e. either water or methanol. Characterizations by various physico-chemical techniques (NMR, UV-Vis absorption, fluorescence, infrared spectroscopies, microscopies, scatterings) demonstrated the formation of fibrillar aggregates for all molecules in such polar environments. Overall, this study suggest that the triarylamine core act as the main driving force for the self-assembly into columnar aggregates while side chains ensure solubility in these solvents and/or favor the formation of chiral architectures. In a second study, we investigated the formation of tris-amide triarylamine supramolecular polymers decorated with norbornene and siloxane end side chains, which could be further used to freeze the self-assembled structures by ring opening metathesis polymerization and sol-gel methods, respectively. [...]

Orientador: Carmen Maria Andreazza / Banca: Edson Denis Leonel / Banca: José Williams dos Santos Vilas Boas / Resumo: De acordo com os resultados observacionais de condensações de nuvens moleculares escuras, grandes variações na razão 13CO/C18O são observadas quando se comparam os resultados obtidos nas condensações situadas dentro da mesma nuvem, bem como de nuvem para nuvem. O valor médio dessa razão na condensação principal de Ophiuchus é inferior a 5. Por outro lado, o valor encontrado nas condensações que estão situadas ao norte de Oph é maior que 10. Grandes diferenças também são encontradas quando se comparam os resultados observacionais de diferentes nuvens escuras, tais como Ophiuchus e Taurus, onde são observados também um decréscimo da razão C18O/C17O com o aumento da densidade. Os processos químicos e físicos que governam essas variações ainda não estão claros. Nesse sentido, o objetivo da presente proposta é analisar a influência do colapso gravitacional de condensações de nuvens moleculares escuras na síntese das moléculas CO, C17O, C18O, 13CO, 13C17O e 13C18O. Tal análise é feita com base em comparações entre modelos que consideram diferentes condições entre si, tais como, tamanho da cadeia química, velocidade de colapso, densidade inicial e processos de congelamento de espécies químicas na superfície de grãos de poeira. Os resultados obtidos mostram que o tamanho da cadeia química tem influência nas razões 13CO/C18O e C18O/C17O, mas não tanto quanto a densidade inicial e a velocidade do colapso. Além disso, o congelamento das espécies químicas nos grãos é mais significativo nos estágios mais avançados da evolução da condensação. Os modelos de condensações escuras que sofrem colapso gravitacional lento e em queda livre reproduzem satisfatoriamente as razões 13CO/C18O e C18O/C17O observadas, o que permite concluir que o colapso gravitacional pode ter um importante efeito nas referidas razões. / Abstract: According to the observational results of dark molecular clouds condensations, large variations in the ratio 13CO/C18O are observed when comparing the results obtained in the condensations located within the same cloud and cloud to cloud. The average value of this ratio in the main condensation of Ophiuchus is below 5. On the other hand, the value found in the condensations that are located north of Oph is larger than 10. Large differences are also found when comparing the observational results of different dark clouds such as Ophiuchus and Taurus, in which are also found a decrease of the C18O/C17O ratio with increasing density. The chemical and physical processes that govern these variations are still unclear. In this sense, the objective of this proposal is to analyze the influence of the gravitational collapse of centrally condensed clumps of dense molecular gas in the synthesis of the CO, C17O, C18O, 13CO, 13C17O and 13C18O molecules. This analysis is based on comparisons among models that consider different condition, such as, chemical chain, initial density, speed of collapse and freezing processes of the chemical species on the surface of dust grains. The results show that the size of the chemical chain has influence on the 13CO/C18O and C18O/C17O ratios, but they are not as important as the initial density and the speed of the collapse. Furthermore, the freezing of chemical species on the grains occurs at later times of the collapse. The models of a gravitational free-fall collapsing core and of slowly contracting core with higher initial density are consistent with observations. These results indicate that the gravitational collapse of molecular cores can have an important effect in the 13CO/C18O and C18O/C17O ratios. / Mestre

D. Tech. (Business, Department of Human Resource Management, Faculty of Management Sciences): Vaal University of Technology / Small and medium enterprises (SMEs) are the stronghold of economies and societies worldwide. In Zimbabwe, as in any other country, there is a realisation that SMEs are innovative, flexible and require low startup capital. There is an increased interest in pursuing SMEs as a poverty reduction strategy and as a roadmap to higher living standards. SMEs in Zimbabwe are divided into two sectors, namely the service and the manufacturing sector. SME manufacturers encompass almost every facet of the local economy, such as food processing, toiletry production, the garment, leather and rubber industry, metal fabrication, furniture manufacturing, construction and art. Most research that has been done on the influence of employee perception of equity (EPE), organisational citizenship behaviour (OCB) on organisational commitment (OC) and turnover intention (ITS) has been on large organisations and little attention has been paid to SMEs. Studies on employee perception of equity and organisational citizenship behaviour has not filtered down to SMEs in developing countries. The primary objective of the study is to investigate the influence of OCB, EPE and OC on ITS in Zimbabwe’s SME sector. It also sought to ascertain the kind of relationships between OCB and OC, EPE with OC, OCB with ITS, EPE with ITS and finally OC with ITS. This study sought to determine whether there are any group differences with regard to SMEs employees perceptions on OCB, EPE, OC and ITS according to gender, age and industry type. A quantitative research method was used. Structured questionnaires were distributed to SMEs in five major cities. The data were collected from SME employees. The findings of this study show that there is a significantly positive influence of OCB on OC in the Zimbabwean SMEs. There is a significant strong positive influence of EPE on OC. There is also significant positive relationship between employees’ OCBs and their OC in Zimbabwe’s SME sector. There is a strong positive significant relationship of EPE with ITS and there is a strong positive relationship between employees OCBs and employees’ ITS in Zimbabwean SMEs. Finally, the results reveal that gender, marital status and industry type of the respondent influence OCBs, EPE, OC and their ITS in the Zimbabwean SMEs. Given that today’s business environments for SMEs are characterised by high levels of competition, lack of finance and uncertainty, it is recommended that SME managers should adopt good and proper management styles so that they can make good decisions. Scanning the environment is also necessary for competitive advantage not only for SMEs but also for large firms.

Mezinárodní měnový fond (MMF) je mezinárodní organizace o 185 členech, jejímž hlavním cílem je zajistit stabilitu mezinárodního měnového systému. Cílem této diplomové práce je přiblížit jejímu čtenáři, jaká je role Mezinárodního měnového fondu v současné světové ekonomice, jakým problémům musí čelit a s jakými výzvami se potýká. Práce nejprve představí okolnosti vzniku MMF, jeho cíle, výhody a povinnosti členů, jeho organizační strukturu a finanční zdroje. Následně přiblíží aktivity MMF včetně spolupráce se Světovou bankou a Světovou obchodní organizací. Pozornost je věnována i kritickým hlasům vně i uvnitř MMF, které jej přinutily k reformám v rámci programu Medium Term Strategy, jímž se zabývá poslední kapitola této práce.

The aim of this study is to compare implementation, impact and sustainability of educational projects in small and medium enterprises which are funded by the European Social Fund. The results of the analysis should give us an answer to the question whether the financial support is used effectively and contributes to the fulfilment of its objectives or the potential of these funds remains untapped. The theoretical part deals with the current situation analysis of training and development of employees in SMEs, different methods of measuring the effectiveness of company training as well as the opportunities of training promotion in SMEs with support of the ESF. The practical part is focused on comparing the implementation of educational projects funded by the Operational Programme Prague -- Adaptability and Operational Programme Human Resources and Employment in chosen SMEs. These companies are compared with enterprises that fund their educational programmes with their own resources and with respect to differences resulting from their size measured by number of employees. This comparison enables us to assess the effectiveness of the use of public funds in this area.

Growing competitiveness in energy sector, uncertainty about economic growth and increasing regulation all lead to diminishing growing potential for a energy company. It is a challenge for business management and business planning to search, create and explore company's potential. Therefore planning process in the studied energy company E.ON is analysed as a management tool for implementation of company strategy. The strategy itself is analysed in order to evaluate mid-term planning in E.ON. The subplans, financial indicators and key performance indicators are evaluated. New system of key performance indicators is designed.

Neste trabalho primeiramente estudamos os efeitos na propagação de ondas de Alfvén em plasmas empoeirados encontrados em inúmeros ambientes astrofísicos. A relação de dispersão da onda é modificada apresentando novos mecanismos de amortecimento. Há na literatura dados observacionais que indicam a existência de condições para crescimento de partículas de poeira na base da atmosfera de estrelas gigantes e supergigantes frias. Construímos um modelo de perda de massa para essas estrelas no qual mostramos que um fluxo de ondas de Alfvén, amortecido pela presença de poeira, pode contribuir para a geração de um vento de baixa velocidade e alta taxa de perda de massa, de acordo com as observações. Já no caso de estrelas quentes, mostramos como é possível obter as condições ideais para formação e crescimento destas partículas em um modelo de colisão de ventos em sistemas binários. A partir deste modelo, é possível explicar as altas emissões em raios-X observadas, além do crescimento de grãos no pós-choque. Aplicando a idéia ao sistema binário de eta Carinae, o modelo permite a determinação dos parâmetros orbitais do sistema. A poeira contida nos ventos estelares é então ejetada para o meio interestelar. Através de um cálculo semi-empírico determinamos a importância de cada intervalo de massa estelar, em cada etapa evolutiva, no retorno de material sólido ao MI. Em regiões de formação estelar investigamos como as ondas de Alfvén, amortecidas pela presença de poeira, influenciam a estabilidade de nuvens moleculares. Em oposição às teorias encontradas na literatura, mostramos que uma nuvem molecular anã, suportada apenas por pressão magnética, não pode ser dinamicamente estável. / In this work, we firstly discuss the propagation of Alfvén waves in dusty plasmas found in several astrophysical environments. The wave dispersion relation is modified giving rise to new damping mechanisms. There are in the literature observational data indicating the presence of dust near the surface of cool giant and supergiant stars. We developed a stellar mass loss model where we show that a flux of Alfvén waves, damped by the dust presence,can generate a low velocity and high mass loss rate wind, in agreement with the observations. In the case of hot stars we show how it is possible to obtain the special conditions for dust growth in a wind collision model of massive binary systems. For this model it is possible to explain both, the high X-rays emissions and dust growth at the post-shock phase. Applying the idea to the $eta$ Carinae binary system, the model allows the determination of the system orbital and the stellar wind parameters. The stellar wind´s dust is then ejected to the interstellar medium. In a semi-empirical calculation we showed the importance of each stellar mass, at each evolutionary phase, on the dust feedback of the ISM. For star formation regions, we investigate the role of Alfvén waves, damped by the dust presence, on the stability of the molecular clouds. In spite of the works found in the literature, we showed that a dwarf molecular cloud, magnetically supported only, is unstable.

Os eletrocatalisadores PtRh/C foram preparados nas seguintes proporções atômicas: (100,0), (0,100), (90,10), (70,30) e (50,50). Os métodos empregados nas sínteses foram redução via borohidreto de sódio e redução por álcool. Os sais metálicos empregados foram H2PtCl6.6H2O e (RhNO3)3 e o suporte de carbono utilizado foi carbon Vulcan XC72, a composição metálica em massa foi de 20%; e o suporte, 80%. Os eletrocatalisadores foram caracterizados por técnicas físico-químicas, espectroeletroquímica e por experimento em célula a combustível, cujo emprego se deu por uma célula unitária direta a álcool com membrana alcalina. Os eletrodos de trabalho foram preparados pela técnica de camada fina porosa. A técnica de difração de raios X permitiu verificar ligas metálicas, fases segregadas e calcular a porcentagem de ligas metálicas, bem como constatar os tipos de fases cristalinas. A técnica de espectroscopia no infravermelho permitiu verificar que a oxidação eletroquímica do etanol se dá pelo mecanismo indireto de oxidação, ou seja, para todos materiais estudados houve a produção de espécies intermediárias, em que PtRh(70:30)/C sintetizado pelo médodo de redução via borohidreto de sódio produziu grandes quantidades de CO2 e C2H4O. Rh/C mostrou-se ativo eletroquimicamente para ambos os métodos de síntese empregados. A técnica de microscopia eletrônica de transmissão permitiu calcular o tamanho médio e a área superficial média dos eletrocatalisadores. As técnicas eletroquímicas permitiram verificar a estabilidade, potencial onset e pares redox dos sistemas considerados. / PtRh/C were prepared by the following atomic proportions: (100,0), (0,100), (90,10), (70,30) and (50,50). The methods employed in the synthesis of these materials were reduction by sodium borohydride and reduction by alcohol. The metal salts used were H2PtCl6.6H2O and (RhNO3)3, the support used was Carbon black XC72 and the bulk metal composition was 20% and 80% of support. The electrocatalysts were characterized by Energy Dispersive X-ray spectroscopy, X-ray diffraction and Transmission electron microscopy. The ethanol electrochemical oxidation mechanism was investigated by in situ Fourier Transform Infrared Spectroscopy couple to an Attenuated Total Reflection technique. The electrocatalytic activity were evaluated by Cyclic Voltammetry, Linear Sweep Voltammetry and Chronoamperometry techniques. The Fuel Cells tests were made in a single direct alcohol fuel cell with alkaline membrane. The working electrodes were prepared by a thin porous coating technique. X-ray diffraction allowed us to verify metallic alloys, segregate phases and to calculate the percentage of metallic alloys. It was else possible to identify crystallographic phases. Infrared Spectroscopy allowed us to verify that the electrochemical oxidation of ethanol was carried out by an incomplete mechanism. PtRh(70:30)/C prepared by sodium borohydride produced large amounts of carbon dioxide and acetaldehyde. Rh/C showed electrocatalytic activity when compared with other materials studied.

O objetivo principal dessa dissertação consiste em analisar o processo de estruturação intra-urbana de Passo Fundo, à luz das dinâmicas socioeconômicas que a caracterizam como cidade média que desempenha funções de centro regional e de apoio ao agronegócio. Para tanto, assumindo a sobreposição de escalas analíticas como uma premissa de método, organizamos a pesquisa em duas partes. Na primeira, a partir de referencial teórico pautado em estudos da Rede de Pesquisadores sobre Cidades Médias (RECIME) e nas teorias de Milton Santos, buscamos analisar as relações horizontais que a cidade estabelece com a região, sobretudo através da oferta de comércio, saúde e educação superior; num outro nível de análise abordamos as relações verticais que se estruturam em rede, extrapolam a região e inserem Passo Fundo em circuitos econômicos globalizados relativos à produção de alimentos, como cidade de apoio ao agronegócio. Na segunda parte do trabalho, a partir dos estudos de Flávio Villaça sobre a formação do espaço intra-urbano brasileiro, analisamos a estrutura intra-urbana de Passo Fundo a partir de seus elementos principais (o centro, as áreas industriais e as áreas residenciais segundo as classes sociais) enfatizando suas localizações e a maneira como se articulam, assim como a atuação dos diferentes grupos sociais enquanto agentes produtores-consumidores do espaço intra- urbano. Em linhas gerais, observamos que as dinâmicas socioeconômicas regionais definiram o ritmo da urbanização de Passo Fundo que se intensifica na segunda metade do século XX, em função da reestruturação produtiva da agricultura e da consolidação da cidade como centro regional. Estruturada ao longo de caminhos regionais como local de passagem, a cidade passa a crescer em ritmo mais intenso após 1950, como destino principal das migrações do campo e de outras cidades do entorno. O incremento populacional gera novas demandas urbanas e evidencia a produção de uma periferia carente, em paralelo à concentração de investimentos públicos na área central, consolidada como local de moradia das classes de alta renda e objeto de valorização fundiária e imobiliária. Caracteriza-se assim um típico modelo de segregação centro-periferia, condicionado aos interesses de mercado e legitimado pelo Estado. Atualmente, o dinamismo econômico expresso pelo crescimento do setor terciário e pela industrialização da economia se manifesta na cidade a partir da inserção de novos vetores de expansão urbana, expressos pela implantação de um grande loteamento de uso misto de média e alta renda assim como de condomínios de luxo na periferia. Ressaltamos que embora se manifestem em diferentes intensidades e complexidades, os processos em Passo Fundo têm a mesma natureza daqueles observados em outras cidades médias e também nas metrópoles, uma vez que se inserem na mesma estrutura social e resultam, em última análise, da produção capitalista da cidade, legitimada pelo Estado e comandada pelas classes dominantes. / This dissertation main goal is to analyze the intra-urban structuring process of Passo Fundo, focusing on the socioeconomic dynamics that qualify the city as a medium-size one, owner of functions such as regional center or supportive local for agricultural business. For such an aim, we intend to assume an overlap of analytical scales as a premiss for methodology, which has led the organization of our research to divide itself into two parts. In the first one, based on theoric references that come from the studies of the Medium-Size Cities Researchers Web (Rede de Pesquisadores sobre Cidades Médias - RECIME) and also from Milton Santos ideas, we examined the horizontal relations between the city and its region, mainly the relations that concern to commercial and health services and also university education; in another analytic level, we observed the vertical relations, web structured, which go beyond the regional territory and place Passo Fundo in economic and globalized circuits related to food production (thanks to its already mentioned support to agricultural business). In the second part of this dissertation, taking Flávio Villaça\'s studies about the formation of Brazilian intra-urban space as a ground, we commented the same theme related to Passo Fundo: the main elements of the city were priorized (the center, its industrial and residential areas - and its separation in social classes) in an investigation that emphasized the location and the way these elements articulate themselves in the city; as well as the actions of social groups, in the aspects of production and consumism of goods in the intra-urban space. Briefly, we observed the socioeconomic dinamics (located in a regional sphere) as definers to the urbanization rhythm in Passo Fundo - which has intensified itself in the second part of the XXth century, due to productive restructuration on agriculture and the consolidation of the city as a regional center. Passo Fundo was structured along regional roads and definied as a city for transition, it starts to grow faster after 1950, and it becomes the main destiny for migrants from the country and satellite cities around. Such a growth on population generates new urban demands and produces a notable needy periphery, parallelly to the concentration of public investments in the central area - which has consolidated itself as a residential place for the higher society, and also as a goal for land and housing speculation. By theses means, a typic segregational model (the center-periphery one) is characterized, and it shows itself as conditioned to market interests which are state-legitimated. Currently, the economic dynamism expressed in the third and second sector manifests itself in the city through the insertion of new vectors in the urban expansion, which show themselves in the implantation of a great allotment willing to mix use (for high and middle classes), as well as luxurious condominiums in the periphery. Although these processes manifest with different intensities and complexities, we highlight them in Passo Fundo as sharing the same nature of the ones observed in medium-size and metropolitan cities, as they are inserted in the same social structure and are product, ultimately, of the capitalist development of the city, owned by the high classes and state-legitimated.