Most free-living bacteria will encounter different environments and it is therefore critical to be able to rapidly adjust to new growth conditions in order to be competitively successful. Responding to changes requires efficient gene regulation in terms of transcription, RNA stability, translation and post-translational modifications. Studies of an extremely slow-growing mutant of Salmonella enterica, with a Glu125Arg mutant version of EF-Tu, revealed it to be trapped in a stringent response. The perceived starvation was demonstrated to be the result of increased mRNA cleavage of aminoacyl-tRNA synthetase genes leading to lower prolyl-tRNA levels. The mutant EF-Tu caused an uncoupling of transcription and translation, leading to increased turnover of mRNA, which trapped the mutant in a futile stringent response. To examine the essentiality of RNase E, we selected and mapped three classes of extragenic suppressors of a ts RNase E phenotype. The ts RNase E mutants were defective in the degradation of mRNA and in the processing of tRNA and rRNA. Only the degradation of mRNA was suppressed by the compensatory mutations. We therefore suggest that degradation of at least a subset of cellular mRNAs is an essential function of RNase E. Bioinformatically, we discovered that the mRNA of tufB, one of the two genes encoding EF-Tu, could form a stable structure masking the ribosomal binding site. This, together with previous studies that suggested that the level of EF-Tu protein could affect the expression of tufB, led us to propose three models for how this could occur. The stability of the tufB RNA structure could be affected by the elongation rate of tufB-translating ribosomes, possibly influenced by the presence of rare codons early in the in tufB mRNA. Using proteomic and genetic assays we concluded that two previously isolated RNAP mutants, each with a growth advantage when present as subpopulations on aging wild-type colonies, were dependent on the utilization of acetate for this phenotype. Increased growth of a subpopulation of wild-type cells on a colony unable to re-assimilate acetate demonstrated that in aging colonies, acetate is available in levels sufficient to sustain the growth of at least a small subpopulation of bacteria.

The aim of this thesis is to determine whether surface electromyography (EMG) can be used as a diagnostic tool in chiropractic practice to identify the functional status of the lumbar paraspinal muscles. There were two main studies to achieve this aim. The reliability and validity of the surface EMG signal to measure the activity of paraspinal muscles during maintenance of simple static postures was evaluated. During maintenance of static postures, the raw surface EMG signal was often contaminated by an electrocardiographic (ECG) signal. Although the ECG artefact was successfully removed using two different ECG removal techniques (manual and semi-automatic), the reliability of the surface EMG signal was not significantly improved (ICC less than 0.75) for both non-normalised and normalised data. Therefore the static postures that were used in this thesis did not provide a protocol that can be used to measure the functional status of the lumbar paraspinal muscles in clinical practice. However, when muscle contraction was at a moderate level, the reliability of EMG signal became better. Walking was considered to be a possible protocol to record a reliable surface EMG signal from paraspinal muscles. Three components of the surface EMG signal were used to characterise the pattern of muscle activity during steady state walking. The narrow window technique was used to characterise the peak activation point of the activity envelope in order to capture a stationary signal from which to calculate amplitude and frequency measures. Walking is a cyclic activity. The back muscles contract rhythmically during a single gait cycle. It is possible to identify the start and end points of the activity envelope associated with the rhythmic contraction of the muscles and define the timing of the muscle activation cycle relative to heel strike. The metronome was found to be useful to control the pace of natural walking in this study. The surface EMG signal of the first recording minute (1 ~ 2 minute) was not associated with a signal that was stable in terms of the parameters that were used in this study. It wa s found that the last recording minute (9 ~ 10 minute) can be used. This suggests that it may be necessary for subjects to walk for a defined period lasting some minutes before the commencement of recording of the surface EMG. Surface EMG may be used as a tool to measure activation patterns of the low back muscles during muscle contraction associated with the support of various static postures or during the execution of dynamic movements such as walking in the real world. The static postures used in this thesis to record the surface EMG signal from the lumbar paraspinal muscles were found not to provide the basis for a reliable and valid tool. However, a walking exercise might be an alternative activity which can be used easily in clinical practice. The components of the surface EMG signal that may be used in future studies might include measures of the amplitude, frequency and timing of the surface EMG signal.

Smoothing is an important part of the pre-processing step in Signal Processing. A signal, which is purified from noise as much as possible, is necessary to achieve our aim. There are many smoothing algorithms which give good result on a stationary data, but these smoothing algorithms don&rsquo / t give expected result in a non-stationary data. Studying Acceleration data is an effective method to see whether the smoothing is successful or not. The small part of the noise that takes place in the Displacement data will affect our Acceleration data, which are obtained by taking the second derivative of the Displacement data, severely. In this thesis, some linear and non-linear smoothing algorithms will be analyzed in a non-stationary data set.

Leakage and blockage of oil and gas pipeline systems, water pipelines, pipe-work of process plants and other pipe networks can cause serious environmental, health and economic problems. There are a number of non-destructive testing (NDT) methods for detecting these defects in pipeline systems such as radiographic, ultrasonic, magnetic particle inspection, pressure transient and acoustic wave methods. In this study, the acoustic wave method and a modal frequency technique, which based on a roving mass method, are used. The aim of the thesis is to employ acoustic wave propagation based methods in conjunction with stationary wavelet transform (SWT) to identify leakage and blockage in pipe systems. Moreover, the research is also aimed at using the difference of modal frequencies of fluid-filled pipes with and without defects and a roving mass, and consequently, to develop a roving mass-based defect detection method for pipelines. In the study, the acoustic finite-element analysis (AFEA) method is employed to simulate acoustic wave propagation in small and large air-filled water-filled straight pipe and pipe networks with leakage and blockage but without flow. Computational fluid dynamics (CFD) analysis was also employed to simulate acoustic wave propagation in air-and water-filled pipes with flow, leakage and blockage. In addition, AFEA was used to predict the modal frequencies of air- and water-filled pipes with leakage and blockage in the presence of a roving mass that was traversed along the axis of the pipes. Experimental testing was conducted to validate some of the numerical results. Two major experiments were performed. The first set of experiments consisted of the measurement of acoustic wave propagation in a straight air-filled pipe with leakage and blockage. The second set of experiments concerned the measurement of acoustic wave propagation in an air-filled pipe network comprising straight pipe, elbows and T-piece and flange. The AFEA and CFD analysis of fluid-filled pipe can be used to simulate the acoustic wave propagation and acoustic wave reflectometry of a fluid-filled pipe with leakage and blockage of different sizes down to a small leakage size of 1mm diameter and a blockage depth of 1.2mm in a pipe. Similarly, the AFEA method of a static fluid-filled pipe can be used to simulate acoustic wave modal frequency analysis of a fluid-filled pipe with leakage and blockage of different sizes down to a leakage of 1mm diameter and a blockage depth of 1.2mm. Moreover, the measured signal of acoustic wave propagation in an air-filled can be successfully decomposed and de-noised using the SWT method to identify and locate leakages of different sizes down to 5mm diameter, and small blockage depth of 1.2mm. Also, the SWT approximation coefficient, detail and de-noised detail coefficient curves of an air-filled pipe with leakage and blockage and a roving mass give leakage and blockage indications that can be used to identify, locate and estimate the size of leakage and blockage in a pipe.

Submitted by Daniella Santos (daniella.santos@fgv.br) on 2010-03-23T12:01:36Z No. of bitstreams: 1 Dissertacao_Jefferson_Donizeti_Bertolai.pdf: 274926 bytes, checksum: a60c8343a27883dd5e7f529f517bc2e8 (MD5) / Approved for entry into archive by Andrea Virginio Machado(andrea.machado@fgv.br) on 2010-03-23T12:31:24Z (GMT) No. of bitstreams: 1 Dissertacao_Jefferson_Donizeti_Bertolai.pdf: 274926 bytes, checksum: a60c8343a27883dd5e7f529f517bc2e8 (MD5) / Made available in DSpace on 2010-03-24T12:48:06Z (GMT). No. of bitstreams: 1 Dissertacao_Jefferson_Donizeti_Bertolai.pdf: 274926 bytes, checksum: a60c8343a27883dd5e7f529f517bc2e8 (MD5) Previous issue date: 2009-12-08 / The dificulty in characterizing non-stationary allocations or equilibria is one of the main explanations for the use of concepts and assumptions that trivialize the dynamics of the economy. This di¢ culty is especially critical in Monetary Theory, in which the dimensionality of the problem is high even for very simple models. In this context, this paper reports the computational strategy for implementing the recursive method proposed by Monteiro and Cavalcanti (2006), which allows you to calculate the optimal sequence (possibly non-stationary) of distributions of money in an extension of the model proposed by Kiyotaki and Wright (1989). Three aspects of this calculation are emphasized: (i) the computational implementation of the plannerís problem involves the choice of continuous and discrete variables that maximize a nonlinear function and satisÖes nonlinear constraints; (ii) the objective function of this problem is not concave and constraints are not convex, and (iii) the set of admissible choices is not known a priori. The goal is to document the di¢ culties involved, the proposed solutions and available methods and resources to implement the numerical characterization of e¢ cient monetary dynamics under the assumption of random matching. / A dificuldade em se caracterizar alocações ou equilíbrios não estacionários é uma das principais explicações para a utilização de conceitos e hipóteses que trivializam a dinâmica da economia. Tal dificuldade é especialmente crítica em Teoria Monetária, em que a dimensionalidade do problema é alta mesmo para modelos muito simples. Neste contexto, o presente trabalho relata a estratégia computacional de implementação do método recursivo proposto por Monteiro e Cavalcanti (2006), o qual permite calcular a sequência ótima (possivelmente não estacionária) de distribuições de moeda em uma extensão do modelo proposto por Kiyotaki e Wright (1989). Três aspectos deste cálculo são enfatizados: (i) a implementação computacional do problema do planejador envolve a escolha de variáveis contínuas e discretas que maximizem uma função não linear e satisfaçam restrições não lineares; (ii) a função objetivo deste problema não é côncava e as restrições não são convexas; e (iii) o conjunto de escolhas admissíveis não é conhecido a priori. O objetivo é documentar as dificuldades envolvidas, as soluções propostas e os métodos e recursos disponíveis para a implementação numérica da caracterização da dinâmica monetária eficiente sob a hipótese de encontros aleatórios.

Submitted by Alice Yang (yanglice@hotmail.com) on 2011-08-31T16:16:13Z No. of bitstreams: 1 Dissertação Versão Final - Alice Yang (Ago11).pdf: 213202 bytes, checksum: aafd91fefc95482e8137d9185fc59857 (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2011-08-31T19:16:56Z (GMT) No. of bitstreams: 1 Dissertação Versão Final - Alice Yang (Ago11).pdf: 213202 bytes, checksum: aafd91fefc95482e8137d9185fc59857 (MD5) / Approved for entry into archive by Gisele Isaura Hannickel (gisele.hannickel@fgv.br) on 2011-08-31T19:17:18Z (GMT) No. of bitstreams: 1 Dissertação Versão Final - Alice Yang (Ago11).pdf: 213202 bytes, checksum: aafd91fefc95482e8137d9185fc59857 (MD5) / Made available in DSpace on 2011-08-31T19:36:01Z (GMT). No. of bitstreams: 1 Dissertação Versão Final - Alice Yang (Ago11).pdf: 213202 bytes, checksum: aafd91fefc95482e8137d9185fc59857 (MD5) Previous issue date: 2011-08-19 / This study seeks to assess the existence of long-run relationships between price series and how Portfolio Managers use pair trading strategy. A quantitative analysis of the Brazilian stocks is done based on Johansen and Cavaliere methodologies, whose null hypothesis assumes the nonexistence of cointegration between pairs. The results showed that there are few pairs that cointegrates among the price series analyzed, which reinforce the need to portray the strategy carefully while constructing a portfolio. / Este trabalho busca avaliar a existência de cointegração das ações do mercado brasileiro e a forma de utilização da estratégia de arbitragem estatística pelos gestores. Para isso, utilizou-se preços de ações brasileiras em diferentes frequências e janelas e aplicou-se a metodologia de Johansen e Cavaliere, cuja hipótese nula refere-se a não cointegração dos pares. Os resultados mostram que há poucas relações de cointegração entre as séries analisadas, o que ratifica a necessidade de cautela na forma de implantação da técnica na construção de carteiras.

Orientador: Isabel Cristina Sales Fontes Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-10T09:05:57Z (GMT). No. of bitstreams: 1 Fioravanti_LiviaMariaAndrekowisk_M.pdf: 984234 bytes, checksum: 0c41c940c79a927bb0f835b15b3739d0 (MD5) Previous issue date: 2007 / Resumo: Em cromatografia líquida de alta eficiência (CLAE), a coluna é um dos principais componentes do sistema cromatográfico, pois é nela que ocorre a separação. Dessa forma, a busca por fases estacionárias (FE) capazes de realizar separações com alta eficiência e bom desempenho tem sido uma constante em muitos laboratórios de pesquisa. Polissiloxanos substituídos com grupos fenil têm sido intensamente utilizados em cromatografia gasosa, mas a sua aplicação em CLAE tem despertado pouca atenção. Este trabalho apresenta a preparação de FE para CLAE a partir da imobilização de poli(metilfenilsiloxano), por radiação microonda, sobre suporte de sílica. As FE foram caracterizadas por testes físico-químicos e cromatográficos. Escolheu-se a radiação microonda por se mostrar promissora e pouco estudada para imobilização de FE. Para a escolha das melhores condições de radiação foi aplicado um planejamento fatorial, sendo que a potência e o tempo de radiação que resultaram em fases com melhor desempenho cromatográfico foram de 720 W por 70 minutos. Nestas condições, as FE apresentaram alta eficiência (78.000 pratos m), picos simétricos (com fator de assimetria entre 0,9 e 1,2) para compostos apolares e básicos e boa resolução entre os compostos analisados. Os parâmetros cromatográficos indicaram que a radiação microonda melhorou o desempenho das FE, proporcionou um aumento da sua estabilidade frente à fase móvel alcalina e forneceu um bom recobrimento da superfície da sílica pelo polímero. A FE preparada mostrou-se promissora na separação de compostos aromáticos neutros e básicos, como fármacos contendo grupos nitrogenados e agrotóxicos / Abstract: In high performance liquid chromatography (HPLC), the column is one of the most important components of the chromatographic system, because it is in the column that the separation occurs. In this way, the search for stationary phases (SP) able to achieve separations with high efficiency has been a constant in many research laboratories. Phenyl substituted polysiloxanes have been used extensively in gas chromatography, but their application in HPLC has received little attention. This work presents the development of stationary phases for use in HPLC by immobilization of poly(methylphenylsiloxane) by microwave radiation on a silica support. The SP were characterized by physiochemical and chromatographic tests. Microwave radiation was chosen because it appears to be promising and has been little studied for SP immobilization. The best conditions of radiation were chosen using an experimental design, with the microwave power and the radiation time that provided phases with the best chromatographic performance, these being 720 W and 70 minutes. In these conditions, the SP showed high efficiency (78000 plates m), symmetrical peaks (asymmetry factor between 0.9 and 1.2) for nonpolar and basic compounds and good separation for the compounds analyzed. The chromatographic parameters show that microwave radiation improved the performance of the SP and provided an increase in stability in alkaline mobile phases. Besides, it provided a good polymer cover on silica surface, being a promising SP for the separation of neutral and basic aromatic compounds, such as pharmaceuticals with nitrogen groups and agrochemicals / Mestrado / Quimica Analitica / Mestre em Química

Orientadores: Carol Hollingworth Collins, Carla Beatriz Grespan Bottoli / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-16T14:14:29Z (GMT). No. of bitstreams: 1 Vigna_CamilaRosaMoraes_D.pdf: 1190348 bytes, checksum: ab228c805aba8ca12b954e0202343664 (MD5) Previous issue date: 2010 / Resumo: Neste trabalho verificou-se a potencialidade de uso de sorventes e fases estacionárias (FE), obtidos a partir da sorção e/ou imobilização do polímero poli(metiloctilsiloxano) (PMOS) sobre suportes de sílica Kromasil utilizando tamento térmico, na separação, quantificação e validação de uma metodologia para análise de agrotóxicos em amostras de água e caldo de cana-de-açúcar (garapa). Os materiais desenvolvidos foram caracterizados com testes químicos e físicos e aplicados nas etapas de concentração das amostras por extração em fase sólida nos modos off-line e on-line, com posterior separação, por Cromatografia Líquida de Alta Eficiência com detecção UV-Vis. Utilizou-se também o método QuEChERS como alternativa na etapa de extração das amostras de garapa. Os sorventes PMOS mostraram desempenho comparável aos sorventes comerciais, além de sua preparação ser simples, rápida e de menor custo. A FE Kromasil/PMOS utilizada propiciou uma boa separação entre os componentes das amostras de diversos agrotóxicos analisados, similar as fases comerciais, com boas eficiências, resolução e seletividade. A metodologia desenvolvida foi validada e mostrou bons resultados de recuperação para todos os agrotóxicos, além de precisão < 15% e coeficiente de correlaçã > 0,99. O limite de quantificação do método permitiu que os limites máximos de resíduos impostos pelas agências reguladoras para todos os compostos estudados fossem atingidos. Os métodos desenvolvidos e validados foram aplicados na análise de amostras de garapa do comércio local. Não foram observados níveis detectáveis dos agrotóxicos estudados nas amostras analisadas / Abstract: This work investigated the potentiality of use of sorbents and stationary phases (SP), obtained from the sorption and/or immobilization of poly(methyloctylsiloxane) (PMOS) onto the surface of a porous silica Kromasil support using heat, in the separation, quantification and validation of a methodology for analysis of agrochemicals in water and sugar cane samples. Physical-chemical characterization of the developed materials were carried out and applied in the concentration step of the samples in solid phase extraction (SPE) in off-line and on-line mode, with posterior separation, for High Performance Liquid Chromatography (HPLC) with UV-Vis detection. The QuEChERS method (Quick, Easy, Cheap, Effective and Safe) was also used as alternative in the extraction of the sugar cane samples. PMOS sorbents showed comparable performance to the commercial sorbents, with simple, fast and cheap preparation. The Kromasil/PMOS SP used demonstrated a good separation to the components of the samples of agrotoxics analyzed, similar to the commercial phases, with good efficiencies, resolution and selectivity. The developed methodology was validated and showed good results of recovery for the agrotoxics, with precision value < 15 % and correlation coefficient > 0,99. The limit of quantification (LQ) of the method allowed that the maximum residues limits (MRL) for the regulating agencies for all the studied compounds were reached. The developed and validated methods were applied in the analysis of sugar cane samples of the local commerce. Detectable levels of the agrochemicals studied in the analyzed samples were not detected / Doutorado / Quimica Analitica / Doutor em Ciências

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: Isabel Cristina Sales Fontes Jardim / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-18T08:52:01Z (GMT). No. of bitstreams: 1 Delmonde_MarceloViniciusFelizatti_M.pdf: 1020250 bytes, checksum: ae1fcb7db9f7dd24bfaaacbbac027ed9 (MD5) Previous issue date: 2011 / Resumo: Este trabalho apresenta o desenvolvimento de fases estacionárias (FE) para utilização em Cromatografia Líquida de Alta Eficiência em Fase Reversa (CLAE-FR) a partir da imobilização térmica de poli (2-fenilpropil) metilsiloxano (PFPMS) sobre suporte de sílica. Diferentes quantidades de copolímero foram avaliadas, alcançando-se um bom desempenho cromatográfico com uma carga polimérica de 50 % (m/m, polissiloxano/sílica). As melhores condições de temperatura e tempo para a imobilização do copolímero sobre o suporte por tratamento térmico foram: 140 ºC e 6 h, respectivamente. A extração do excesso de copolímero não imobilizado também foi otimizada, obtendo-se o melhor resultado com a utilização de clorofórmio por 3 horas, seguido de metanol por 2 horas, ambos a uma vazão de 1 mL min. A caracterização físico-química do suporte de sílica, copolímero e da FE através de análise elementar, espectroscopia de absorção na região do infravermelho e determinação da área superficial específica, volume e diâmetro de poros das partículas indicam a presença do copolímero sobre o suporte e a espectroscopia de ressonância magnética nuclear sugere que o copolímero se encontra sorvido e quimicamente ligado ao suporte de sílica. As FE preparadas com 50 % de PFPMS apresentaram aproximadamente 16,4 % de C, eficiência de 70.000 pratos m-1 e fator de assimetria dentro da faixa aceita na literatura para o pico do naftaleno (0,9-1,6). Os estudos de aplicação demonstram que a FE desenvolvida apresenta potencial na separação de compostos aromáticos / Abstract: This work presents the development of stationary phases (SP) for use in Reversed-Phase High-Performance Liquid Chromatography (RP-HPLC) prepared by thermal immobilization of poly (phenylpropyl) methylsiloxane (PPPMS) onto a silica support. Differents amounts of copolymer were evaluated, achieving a good performance using a polymeric charge of 50% (m/m, polysiloxane/silica). The best conditions of temperature and time for immobilization onto silica support by thermal treatment were: 140 ºC and 6 h, respectively. The non immobilized copolymer extraction was also optimized, where the best results were achieved using chloroform for 3 hours, followed by methanol for 2 hours, both with a flow rate of 1 mL min. The presence of the copolymer on the silica support was demonstrated by physicochemical characterization of the support, the PPPMS and the SP by elemental analysis, infrared absorption spectroscopy and determining the volume and pore diameter of the particles, while nuclear magnetic resonance spectroscopy suggests sorption and chemical bonding between the support and polysiloxane. The SP prepared with 50% PPPMS showed approximately 16.4% of C, efficiencies of 70,000 plates m-1 and asymmetry factors within the range accepted in the literature for the peak of naphthalene (0.9-1.6). The application studies showed that the SP developed presents potential capacity for separation of aromatic compounds / Mestrado / Quimica Analitica / Mestre em Química