Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-06-17T14:33:52Z No. of bitstreams: 1 Dissertação - Cristian Rossi.pdf: 662641 bytes, checksum: 1f075c90b91e26f1afdb51e139918633 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-17T20:40:09Z (GMT) No. of bitstreams: 1 Dissertação - Cristian Rossi.pdf: 662641 bytes, checksum: 1f075c90b91e26f1afdb51e139918633 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2015-06-17T20:42:11Z (GMT) No. of bitstreams: 1 Dissertação - Cristian Rossi.pdf: 662641 bytes, checksum: 1f075c90b91e26f1afdb51e139918633 (MD5) / Made available in DSpace on 2015-06-17T20:42:11Z (GMT). No. of bitstreams: 1 Dissertação - Cristian Rossi.pdf: 662641 bytes, checksum: 1f075c90b91e26f1afdb51e139918633 (MD5) Previous issue date: 2013-03-27 / FAPEAM - Fundação de Amparo à Pesquisa do Estado do Amazonas / Search engines are mechanisms to seek relevant information within large data collections. The constant growth of electronic media for storage information, along with the popularization of search engines, brings the constant need for solutions that reduce processing costs queries. We present two new algorithms for query processing searching systems. The processing algorithms use the approach document-to-document and modify the current algorithm state of the art, BMW, for taking advantage of an index architecture divided into two layers. The first layer contains only the highest impact index entries and is used to preprocess consultations before accessing the rest of the index in the second layer. This approach results in significant performance gains. The first algorithm, called BMW-CS, is up to 40 times more fast compared to many compared methods, but causes small changes in the returned response. The second algorithm, called BMW-t, preserves the answer set and is 10% faster than the BMW. / Sistemas de busca são mecanismos capazes de buscar informação relevante dentro de grandes coleções de dados. O constante crescimento de meios eletrônicos para armazenamento de informação, junto com a popularização dos sistemas de busca, traz consigo a necessidade constante por soluções capazes de reduzir os custos de processamento de consultas. Neste trabalho, apresentamos dois novos algoritmos para processamento de consultas em sistemas de busca. Os algoritmos utilizam a abordagem de processamento documento-a-documento e modificam o atual algoritmo estado-da-arte, BMW, para tirar vantagem de uma arquitetura de índice dividido em duas camadas. A primeira camada contém apenas as entradas de maior impacto do índice e é utilizada para preprocessar as consultas antes de acessar o restante do índice na segunda camada. Esta abordagem resulta em consideráveis ganhos de desempenho. O primeiro algoritmo proposto, chamado BMW-CS, chega a ser 40 vezes mais rápido em relação a diversos métodos comparados, porém provoca pequenas modificações no conjunto de resposta retornado. O segundo algoritmo proposto, chamado BMW-t, preserva o conjunto de resposta e é 10% mais rápido que o BMW.

<p>Purpose: In order to curb the prevalence of undeclared work and to improve competi-tion within the building and construction business, reversed charge audit will from July 1, 2007 onwards be applied within the building sector. The new rules entail a consider-able amount of delimiting problems as regards both businesses and services.</p><p>The aim of this essay is to study the rules as well as direct the light upon various consequen-tial delimiting problems. Furthermore, we will investigate what the effects are on the busi-nesses, as well as their view regarding this. Apart from this, we will also investigate who will benefit and who will be disfavourably affected, respectively, by the new law</p><p>Method: The investigation has been conducted with a combination of qualitative and quantitative methods. Firstly, an opinion poll was carried out, directed towards Swedish construction companies, and this was then deepened using three interviews.</p><p>Result & Conclusions: The essay demonstrates that the new rules have entailed more work to a varying degree for the companies. Most of this is a result of the delimiting problems that follow from the rules being regarded as relatively unclear and incom-plete. Several of the companies have furthermore acquired a positive as well as nega-tive liquidity impact. Many businesses have a negative attitude towards the introduction of a reversed charge, even more of them don’t believe that its purpose will be achieved. Summing up, it can be noted that there are both winners and losers as a consequence of these rules.</p><p>Suggestions for future research: To investigate if the purpose with the introduction been met, i. e. about the undeclared work decreased and the competition been im-proved.</p><p>Contribution of the thesis: To notice the new VAT rules within the construction sector and the delimiting problems that follows.</p>

Purpose: In order to curb the prevalence of undeclared work and to improve competi-tion within the building and construction business, reversed charge audit will from July 1, 2007 onwards be applied within the building sector. The new rules entail a consider-able amount of delimiting problems as regards both businesses and services. The aim of this essay is to study the rules as well as direct the light upon various consequen-tial delimiting problems. Furthermore, we will investigate what the effects are on the busi-nesses, as well as their view regarding this. Apart from this, we will also investigate who will benefit and who will be disfavourably affected, respectively, by the new law Method: The investigation has been conducted with a combination of qualitative and quantitative methods. Firstly, an opinion poll was carried out, directed towards Swedish construction companies, and this was then deepened using three interviews. Result &amp; Conclusions: The essay demonstrates that the new rules have entailed more work to a varying degree for the companies. Most of this is a result of the delimiting problems that follow from the rules being regarded as relatively unclear and incom-plete. Several of the companies have furthermore acquired a positive as well as nega-tive liquidity impact. Many businesses have a negative attitude towards the introduction of a reversed charge, even more of them don’t believe that its purpose will be achieved. Summing up, it can be noted that there are both winners and losers as a consequence of these rules. Suggestions for future research: To investigate if the purpose with the introduction been met, i. e. about the undeclared work decreased and the competition been im-proved. Contribution of the thesis: To notice the new VAT rules within the construction sector and the delimiting problems that follows.

Control of MHD instabilities using a conducting wall together with external magnetic fields is an important route to improved performance and reliability in fusion devices. Active control of MHD modes is of interest for both the Advanced Tokamak and the Reversed Field Pinch (RFP) configurations. A wide range of unstable, current driven MHD modes is present in the RFP. An ideally conducting wall facing the plasma can in principle provide stabilization to these modes. However, a real, resistive wall characterized by a wall field diffusion time, cannot stabilize the ideal MHD modes unless they rotate with Alfvénic velocity, which is usually not the case. With a resistive wall, the ideal modes are converted into resistive wall modes (RWM) with growth rates comparable to the inverse wall time. Resistive wall modes have been studied in the EXTRAP T2R thin shell RFP device. Growth rates have been measured and found in agreement with linear MHD stability calculations. An advanced system for active control has been developed and installed on the EXTRAP T2R device. The system includes an array of 128 active saddle coils, fully covering the torus surface. Experiments on EXTRAP T2R have for the first time demonstrated simultaneous active suppression of multiple independent RWMs. In experiments with a partial array, coupling of different modes due to the limited number of feedback coils has been observed, in agreement with theory. Different feedback strategies, such as the intelligent shell, the rotating shell, and mode control have been studied. Further, feedback operation with different types of magnetic field sensors, measuring either the radial or the toroidal field components have been compared / QC 20100929

The benefits of fibre reinforced concrete (FRC) have been thoroughly investigated. Much of this work has focussed on steel FRC subjected to monotonic loads. Data on the structural behaviour of macro-synthetic FRC or FRC under cyclic loads is scarce. A pilot investigation on the shear behaviour of macro-synthetic FRC and on the behaviour of FRC under reversed cyclic in-plane shear loading was carried out. Five in-plane shear panel tests were performed. The parameters under study were the fibre material type (steel or macrosynthetic) and loading protocol. Additionally, a number of compression, direct tension, and flexural tests were performed to determine the material properties of the concretes for comparison. The material response of 2.0% by volume of macro-synthetic FRC matched closely with 1.0% steel FRC. Finally, building upon an existing steel FRC model, a model for macro-synthetic FRC in tension was proposed and a short verification study was undertaken.

The benefits of fibre reinforced concrete (FRC) have been thoroughly investigated. Much of this work has focussed on steel FRC subjected to monotonic loads. Data on the structural behaviour of macro-synthetic FRC or FRC under cyclic loads is scarce. A pilot investigation on the shear behaviour of macro-synthetic FRC and on the behaviour of FRC under reversed cyclic in-plane shear loading was carried out. Five in-plane shear panel tests were performed. The parameters under study were the fibre material type (steel or macrosynthetic) and loading protocol. Additionally, a number of compression, direct tension, and flexural tests were performed to determine the material properties of the concretes for comparison. The material response of 2.0% by volume of macro-synthetic FRC matched closely with 1.0% steel FRC. Finally, building upon an existing steel FRC model, a model for macro-synthetic FRC in tension was proposed and a short verification study was undertaken.

This thesis is the first study using contemporary spatial theory, including cultural geography and its precursors, to examine and compare representations of space in the poetry of three mid-twentieth century American poets: Robert Lowell, Sylvia Plath, and Anne Sexton. Because of the autobiographical content often foregrounded in their work, these poets have been labelled Confessional. Previous criticism has focused primarily on the ways in which they narrate (or draw on) their personal lives, treating accompanying descriptions of their surroundings primarily as backdrops. However, these poets frequently manifest their affective states by using the pathetic fallacy within structures of metaphor that form a textual mapping of the physical space they describe. This mapping can be temporal as well as spatial; the specific spaces mapped in the poem s present are often linked to memories of earlier life or family. These spaces include psychiatric, general, and penal institutions, parks and gardens, nature (especially coastal settings), and the home (almost always a place of tension or conflict). Each poet addresses these broad types of space differently according to their evolving subjective relationship to them. These relationships are in turn strongly influenced by their social class and gender: for the two women, their experience of their own bodies as prescribed space, in relation to the restrictive and objectifying female role that was imposed on them, is critical. Also, critical in shaping the poets experience of space are post-World-War II socio-cultural and demographic changes in the United States, notably suburbanisation, consumerisation and the consolidation of a therapeutic culture . Interwoven with these influences are major political concerns of the period such as the Cold War with its accompanying surveillance and conformism and the threat of nuclear annihilation. In the work of all three poets, awareness of these modern fears fused with traditional Gothic motifs to permeate their descriptions of spaces with anxiety, bitterness, and even dread in a rejection of the synthetic optimism of the American Century and commercial culture. Other criticism has touched on many of these themes in relation to one or another of the poets, but this study, by way of the theme of space, offers comparison and synthesis that aims to shed new light on their work and its relation to the period during which they wrote.

Made available in DSpace on 2015-05-14T13:24:23Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2292715 bytes, checksum: cb27e9ba3f75b8d32163a1ae715a147c (MD5) Previous issue date: 2008-05-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / High Performance Liquid Chromatography (HPLC) allows both qualitative and quantitative chemical analysis, separating and identifying substances in mixtures with speed and efficiency. However, factors governing chromatographic retention are complex and the method development phase consumes a lot of resources. In our work we evaluated a chromatographic simulation software package (HIPAC-G, HIPAC-B e HIPAC-S, Phenomenex, Torrance, USA) for optimizing the chromatographic separation of eight flavonoid standards (3-O-[β-Dglucopyranosyl-( 1→6)-α-L-ramnopyranosyl]-7-O-α-L-ramnopyranosyl kampferol; hesperidine; kampferol; tiliroside; quercetin; 3,4 ,7,8-tetra-O-methyl-gossypetine; 3,3 ,4 ,7,8-penta-O-methylgossypetine and 3,3 ,4 ,7-tetra-O-methyl-quercetin). The HIPAC model of retention is based on the known linear relationship that exists between the retention factor of an analyte and the percentage of organic solvent in the mobile phase, to simulate retention data. Using gradient elution, three trial runs were done (preliminary runs that are used to input retention data to the software). The first trial run used a C18 column (250 x 4,6 mm, 5 m) and as mobile phase a gradient from 5 to 95% of acetonitrile (solvent B) in 0,1% formic acid (solvent A) at a flow rate of 1 mL/min with UV detection at 264 nm. The first trial run was comprised of two gradient runs using the same chromatographic conditions but different gradient duration times (30 and 60 minutes respectively). The second trial run used the same chromatographic conditions as the first one, but methanol instead of acetonitrile as the organic modifier and 10% and 100% as the initial and final %B, respectively. The third trial run was done with the same chromatographic conditions as the second one, but using a column with different stationary phase and dimensions (C8, 150 x 4,6 mm, 5 m). The retention data of the three trial runs were used as input to the simulation software, using the HIPAC-G module. For isocratic mode simulation using the HIPAC-B module, both a C8 (150 x 4,6 mm, 5 m) and a C18 (250 x 4,6 mm 5 m) column was used with binary mixtures of MeOH (solvent B) in 0,1% formic acid (solvent A). Two trial runs with 60% and 70%B were done for each column and the resulting retention data used as input for simulation. The optimized separation conditions as suggested by HIPAC-B were used as input for HIPAC-S to optimize the system chromatographic conditions. The optimization criterion used for all simulations was the average global resolution for all peaks in the chromatogram. Altogether twelve simulations in gradient elution mode and four isocratic simulations were done. The simulated retention data was then confronted with experimentally obtained retention data for the eight flavonoid standards. The correlation coefficient (r2) between simulated and observed retention times for the analytes when eluted in gradient mode varied from 0,9416 to 0,9992 (n=12). The correlation coefficient in isocratic mode varied from 0.9999 to 1 (n=4), indicating an excellent efficiency in predicting retention data for the mixture tested. Taken together our results show that the use of chromatographic simulation software such as HIPAC-G, HIPAC-B e HIPACS can constitute an important tool in the optimization of separation conditions of complex mixtures, such as those found in the field of natural products. / A Cromatografia Líquida de Alta Eficiência (CLAE) permite análises químicas qualitativas e quantitativas, separando e identificando substâncias em misturas com rapidez e eficiência. Entretanto, os fatores que governam a retenção cromatográfica são complexos e a fase de desenvolvimento de métodos consome muitos recursos. Em nosso trabalho nós avaliamos um pacote de softwares de simulação cromatográfica (HIPAC-G, HIPAC-B e HIPAC-S, Phenomenex, Torrance, USA) para otimização da separação cromatográfica de oito padrões de flavonóides: (3-O-[β-D-glicopiranosil-(1→6)-α-L-ramnopiranosil]-7-O-α-Lramnopiranosilkanferol; hesperidina; kanferol; tilirosideo; quercetina; 3,4 ,7,8-tetra-O-metilgossipetina; 3,3 ,4 ,7,8-penta-O-metil-gossipetina; 3,3 ,4 ,7-tetra-O-metil-quercetina). O modelo de retenção do HIPAC se baseia na conhecida relação linear entre o fator de retenção de um analito e a porcentagem de solvente orgânico na fase móvel para simulação de dados de retenção. Utilizando eluição em modo gradiente, três corridas preliminares foram realizadas (corridas preliminares são usadas para inserir dados de retenção para o software). A primeira corrida preliminar usou uma coluna C18 (250 x 4,6 mm, 5 m) e como fase móvel um gradiente de 5 a 95% de acetonitrila (solvente B) e acido fórmico a 0,1% (solvente A) a um fluxo de 1 mL/min com detecção no ultravioleta a 264 nm. A primeira corrida preliminar foi composta de duas corridas em modo gradiente usando as mesmas condições cromatográficas, mas com diferentes durações de tempo de gradiente (30 e 60 minutos respectivamente). A segunda corrida preliminar utilizou as mesmas condições cromatográficas da primeira, mas como modificador orgânico usou metanol ao invés de acetonitrila e %B inicial e final de 10% e 100%, respectivamente. A terceira corrida preliminar foi feita com as mesmas condições cromatográficas da segunda corrida, mas utilizando uma coluna com fase estacionária e dimensões diferentes (C8, 150 x 4,6 mm, 5 m). Os dados de retenção das três corridas preliminares foram usados para alimentar o software de simulação, utilizando o módulo HIPAC-G. Para simulação em modo isocrático usou-se o módulo HIPAC-B, tanto com uma coluna C8 (150 x 4,6 mm, 5 m) quanto C18 (250 x 4,6 mm 5 m) e misturas binárias de MeOH (Solvente B) em 0,1% de ácido fórmico (Solvente A). Duas corridas preliminares com 60% e 70%B foram realizadas para cada coluna e os dados de retenção resultantes foram usados para alimentar a simulação. As condições otimizadas de separação sugeridas pelo HIPAC-B foram usadas como dados para inserção no HIPAC-S para otimizar as condições do sistema cromatográfico. O critério de otimização utilizado para todas as simulações foi a resolução média global para todos os picos no cromatograma. No total, doze simulações em modo gradiente e quatro simulações em modo isocrático foram realizadas. Os dados de retenção simulados foram comparados com os dados experimentalmente obtidos para os oito flavonóides padrões. O coeficiente de correlação (r2) entre os tempos simulados e observados para analitos eluídos em modo gradiente variaram de 0,9416 a 0,9992 (n=12). O coeficiente de correlação em modo isocrático variou de 0.9999 a 1 (n=4), indicando excelente eficiência em predizer dados de retenção para a mistura testada. Tomados em conjunto, nossos resultados mostram que o uso de softwares de simulação cromatográfica tal como HIPAC-G, HIPAC-B e HIPAC-S podem constituir uma importante ferramenta na otimização das condições de separação de misturas complexas, tais como as que são encontradas no campo de produtos naturais.

Orientador: Carol Hollingworth Collins / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-18T09:08:43Z (GMT). No. of bitstreams: 1 Souza_EndlerMarcelBorgesde_D.pdf: 24501631 bytes, checksum: 4fd1866c1e1f40857962b738d98e6eb5 (MD5) Previous issue date: 2011 / Resumo: As propriedades cromatográficas e a estabilidade de fases estacionárias preparadas pela imobilização térmica do poli(metiloctilsiloxano) ou do poli(metiltetradecilsiloxano) sobre a sílica foram avaliadas. Para isso, fora empregados os testes de Engelhardt, Tanaka e SRM 870. O estudo dos mecanismos envolvidos na retenção de solutos básicos nestas fases estacionárias foi feita com um teste desenvolvido em nosso laboratório, que consiste em avaliar os fatores de retenção e a assimetria de solutos hidrofóbicas e hidrofílicas em fases móveis com diferentes valores de pH, preparadas com diferentes tipos e concentrações de tampão. A avaliação das fases estacionárias com os testes SRM 870 e de Tanaka mostram uma alta contribuição dos fenômenos de troca iônica para retenção dos solutos básicos e a comparação dos valores obtidos com o teste de Tanaka, segundo o modelo de Euerby, mostrou que estas fases estacionárias apresentam propriedades cromatográficas distintas da maioria das fases comerciais, embora alguma similaridade tenha sido observada com as fases estacionárias que também apresentam altas contribuições de fenômenos de troca iônica na retenção de solutos básicos. O novo teste desenvolvido mostrou que a retenção de solutos básicos acontece devido a interações sinérgicas dos silanóis residuais com os polisiloxanos imobilizados na forma de gotas sobre a sílica. Devido a estas interações, o pH da fase móvel, o tipo e a concentração de tampão afetam intensamente os fatores de retenção e a assimetria de solutos básicos. Algumas das fases estacionárias apresentaram boa seletividade e picos simétricos para solutos básicos em fases móveis neutras, onde os solutos estam protonados e os silanóis residuais estão desprotonados. Os testes de estabilidade demonstraram que algumas das fases estacionárias são altamente estáveis em fases móveis neutras em temperatura ambiente e em fases móveis ácidas, mesmo a altas temperaturas. No entanto, estas se mostraram instáveis em fases móveis alcalinas mesmo em temperatura ambiente, conforme esperado para fases estacionárias preparadas pela imobilização de polissiloxanos sobre a sílica / Abstract: This work has evaluated the chromatographic properties and the stability of stationary phases prepared by with poly(methyloctylsiloxane) or poly(methyltetradecylsiloxane) thermally immobilized onto a silica surface. The stationary phases were chromatographically evaluated using the Engelhardt, SRM 870 and Tanaka tests. The retention mechanisms involved during the separation of basic solutes with these stationary phases were evaluated using a test developed in our laboratory that evaluates the effect of the mobile phases with different pH, and type and concentration of buffer on the retention factors and asymmetry of several basic solutes (with hydrophobic or hydrophilic characteristics). Evaluations with the SRM 870 and Tanaka tests showed that there is a high contribution of ionexchange interactions at neutral pH. Classifications using the Euerby¿s procedure indicate that the stationary phases developed in this work are different from most commercial ones, although some similarity was found with the phases that have high ion-exchange interactions. Also, the retention of basic solutes occurs due to synergetic interactions between the free silanols with the immobilized polysiloxanes, which are in the form of plugs on the silica surface. Due to these interactions the pH of the mobile phase, and the type and concentration of buffer have a strong effect on the retention factors and asymmetry factors of basic solutes. The stationary phases present good selectivity at near neutral pH, where both the basic solutes and free silanols are protonated, suggesting the use of intermediate pH for basic solute analyses. Stability tests show that the stationary phases have high stability in neutral mobile phases at room temperature and also in acidic mobile phases, even at high temperatures. However, these phases have low stability in alkaline mobile phases, even at room temperature, which was expected for polysiloxanes immobilized onto silica / Doutorado / Quimica Analitica / Doutor em Ciências

Orientador: Elias Basile Tamborgi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-06T23:13:38Z (GMT). No. of bitstreams: 1 Borracini_HeloisaMariaPitaro_M.pdf: 561004 bytes, checksum: e3b9d20443cd5c9315ba77c397ee51dc (MD5) Previous issue date: 2006 / Resumo: Bromelina é o nome dado a um conjunto de enzimas proteolíticas encontradas nos vegetais da família Bromeliaceae, da qual o abacaxi é o mais conhecido. A bromelina tem diversos usos, todos baseados em sua atividade proteolítica. Com a necessidade de desenvolver novos processos de purificação e concentração desses compostos, a extração líquido-líquido por rnicela reversa mostra-se como uma técnica atrativa, pois a micela reversa possui a capacidade de solubilizar biomoléculas específicas de uma solução aquosa, como o extrato bruto do abacaxi. O objetivo desse trabalho foi estudar a recuperação da enzima bromelina através da técnica de extração líquido-líquido por rnicelas reversas. Para tanto, utilizaram-se três sistemas micelares distintos formados a partir de BDBAC (agente tensoativo catiônico), AOT (agente tensoativo aniônico) e CTAB (agente tensoativo catiônico). Foram realizados planejamentos estatísticos com o intuito de realizar uma triagem das variáveis significativas em cada processo. A metodologia de superfície de resposta foi empregada para quantificação dos níveis das variáveis significativas à extração. No presente trabalho são apresentados estudos da influência conjunta que alguns parâmetros exercem sobre a extração líquido-líquido da bromelina com rnicelas reversas, nas etapas de extração e re-extração, para fins de caracterização, modelagem e otirnização / Abstract: Bromelain is a set of proteolitics enzymes found in vegetables of the Bromeliaceae family, from which pineapple is known more. Bromelain has several uses, alI based on its proteolitics activity. There are the necessity to develop new processes for purification and concentration of these composites, the liquid-liquid extraction by reversed micelles reveals as one attractive technique, therefore it has had the specific capacity of getting solub1e biomolecules of an aqueous solution, as the crude extract of the pineapple. This is a study on the recovery of bromelain through liquid-liquid extraction by reversed micelles. Three distinct micelar systems formed from BDBAC (cationic surfactant), AOT (anionic surfactant) and CTAB (cationic surfactant) were employed. Statistical designs were used to select the most significant variables for each process. Surface response methodology was used to quantify the levels of the significant variables. In this work systematic studies are performed on the influence that certain parameters have on the recovery of bromelain through liquid-liquid extraction by reversed micelles, concerning forward and back extration. The goal is the system mathematical characterization and otimization / Mestrado / Sistemas de Processos Quimicos e Informatica / Mestre em Engenharia Química