Orientadores: Alba Regina Monteiro Souza Brito, Elisangela Farias Silva / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T19:44:23Z (GMT). No. of bitstreams: 1 Penteado_ViniciusCamargo_M.pdf: 676076 bytes, checksum: fbc4308afd6512681ecc223478e57f43 (MD5) Previous issue date: 2009 / Resumo: A alimentação inadequada contribui para muitas das causas de morte. Mais de 70% dos tipos de câncer podem ser a ela atribuídos. Neste contexto, surge a importância dos nutracêuticos e sua utilidade na prevenção e tratamento de algumas doenças e o interesse, tanto das indústrias farmacêuticas quanto alimentícias para esta categoria de produto, é crescente. O grupo de pesquisa em produtos naturais do IB-UNICAMP pretende desenvolver um nutracêutico útil na prevenção e tratamento de colites inflamatórias. Sabe-se que substâncias antioxidantes, entre outras presentes nas fibras alimentares, podem estar envolvidas na prevenção e tratamento de doenças intestinais, porque os produtos de sua fermentação, os ácidos graxos de cadeia curta (AGCC), são substratos para a reparação do tecido inflamado, inibindo fatores próinflamatórios. Quantificar estes ácidos é, portanto, imprescindível dado que quanto maior for sua produção, maior será a eficiência da dieta para a recuperação do tecido. Para tanto, foi realizada uma análise in vitro que demonstrou qual das associações de banana e laranja era a que produzia maiores quantidades de butirato, o dado foi obtido através da leitura por HPLC. Depois, in vivo, através de um grupo controle (salina), grupo não tratado (indução de úlcera na ausência da administração da mistura de fibras) e do grupo tratado (indução de úlcera com administração da mistura de fibras) realizou-se a indução de colite por TNBS e, após a obtenção das amostras cólicas dos diferentes grupos, realizou-se a análise da atividade anti-oxidante ( GSH, GPx, GR, MPO e LPO). O grupo não tratado não apresentou diferenças significativas na comparação com o tratado, o que leva a conclusão de que a mistura de laranja e banana escolhida, nas condições de ulceração por TNBS da metodologia aplicada não é eficiente na prevenção dos danos causados. / Abstract: Não informado. / Mestrado / Fisiologia / Mestre em Biologia Funcional e Molecular

Orientador: Elias Basile Tambourgi / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-09T00:56:54Z (GMT). No. of bitstreams: 1 Navarro_RobertaMariaSalvador_D.pdf: 1375421 bytes, checksum: 102cbd9d53b177b6707f723c84f52a4f (MD5) Previous issue date: 2007 / Resumo: A indústria têxtil possui um elevado grau de importância no contexto brasileiro, a constante mudança da moda leva a pesquisa pela novidade e originalidade, sendo criados tecidos diferenciados com propriedades físicas, acabamento e texturas inovadoras. Hoje em dia existem inúmeras fibras têxteis (naturais, animais e sintéticas), além de uma infinita gama de combinações entre elas; e considerando-se fatores como custo e benefício, rapidez na produção, etc., será estudado a fibra de poliéster (PES), pois além de sua versatilidade é a fibra têxtil mais utilizada no mundo. Um dos mais importantes requisitos é a cor dos tecidos de uso doméstico e suas propriedades de solidez (menor ou maior capacidade de resistência da cor ao uso), e isto depende de três fatores principais: o tipo de corante escolhido em função da fibra que compõe o tecido e do uso que se dará ao mesmo, o emprego do processo de tingimento adequado e o processo de lavagem. O tingimento consiste em fixar o corante sobre a fibra. Portanto, o tingimento depende da qualidade da fibra e da composição química do corante. Para fibras de poliéster os corantes mais adequados são os corantes dispersos, que proporcionam um maior rendimento, fixação e resistência da cor, além de boas propriedades de solidez da fibra. Neste contexto, o presente trabalho visa o estudo das propriedades de solidez à luz e de solidez à lavagem das fibras de poliéster tingidas com corantes dispersos, conforme exigências dos consumidores e, seguindo, portanto as Normas ISO. Os resultados obtidos permitiram concluir que as fibras de poliéster possuem boas propriedades de solidez à lavagem doméstica e comercial com sabão comercial comum, visto que, quase não ocorre desbotamento e transferência de cor quando utilizado em concentração recomendadas. Foi concluído também que o poliéster possui boa solidez à luz, isto é possui boa resistência ao desbotamento quando exposto a luz por até 180 horas / Abstract: The textile industry has a high degree of importance in the Brazilian context, the constant fashion change takes to the research for innovation and originality, being created differentiated fabrics with innovative physical properties, finish and textures. Nowadays exist countless textile fibers (natural, animals and synthetic), besides an infinite range of combinations among them; and, and in consideration factors as benefit and cost, speed in the production, etc. it will be studied the polyester fiber (PES), because, besides its versatility it is the textile fiber that more used in the world. One of the most important requirements is the color of the use domestic fabrics and its fastness properties (smaller or larger capacity of color resistance to the use), and this depends on three main factors: the type of chosen dye in function of the fiber that composes the fabric and of the use that will be lead to the same, the employment of the appropriate dyeing process and wash process. The dyeing consists of fixing the dye on the fiber. Therefore, the dyeing depends on the fiber quality and of the dye chemical composition. For polyester fibers the most appropriate dyes are the disperse dyes, that provide a larger performance, fixation and color resistance, besides good fiber fastness properties. In this context, the present work seeks the study the light fastness properties and the wash fastness properties of the polyester fibers dyeing with disperse dye, according to the consumers demands and, following, therefore the ISO Proceeding. The obtained results allowed to conclude that the polyester fibers have good domestic and commercial wash fastness properties with common commercial soap, because, it hardly happens bleaching and color transfer when it used in indicated concentrations. It was also concluded that the polyester has good light fastness, in other words, it has good bleaching resistance when exposed to the light for even 180 hours / Doutorado / Sistemas de Processos Quimicos e Informatica / Doutor em Engenharia Química

Orientador: Newton de Oliveira Pinto Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil / Made available in DSpace on 2018-08-03T20:38:51Z (GMT). No. of bitstreams: 1 Ramos_MarceloFrancisco_M.pdf: 4157437 bytes, checksum: c4709e78995883db4ccd27990e329973 (MD5) Previous issue date: 2002 / Resumo: Neste trabalho são apresentados os resultados de um programa experimental desenvolvido para avaliar a resistência à compressão diametral de tubos de concreto reforçado com fibras de aço. Foram moldados tubos com diâmetro nominal de 600 mm em concretos de resistências médias à compressão, aos 28 dias de idade, de aproximadamente 50MPa. Os tubos foram divididos em seis séries, sendo 5 em concreto simples, 5 em concreto armado, 10 em concreto reforçado com fibras coladas em pentes (5 com teor de 20 kglm3 e 5 com teor de 30 kgl m3) e 10 em concreto reforçado com fibras soltas (5 com teor de 20 kglm3 e 5 com teor de 30 kgl m3). O objetivo é avaliar o comportamento desses tubos de concreto reforçado com fibras de aço, verificando seu desempenho comparativamente à tubos de concreto simples e de concreto armado, quando submetidos ao ensaio de compressão diametral. Foram também determinadas as resistências à compressão simples, à tração na compressão diametral, bem como a tenacidade à flexão dos concretos empregados na produção. Os ensaios realizados demonstraram um comportamento dúctil dos tubos de concreto reforçado com fibras de aço, demonstrando que a substituição das armaduras convencionais pelas fibras de aço é possível, mantendo a mesma capacidade de suporte, com ganhos significativos de durabilidade / Abstract: In this work will be presented the results of an experimental program developed to evaluate the diametrical compressive strenght of concrete pipes reinforced with fibers of steel. They were moulded pipes with nominal diameter of 600 mm in concretes of medium compressive strenght, to the 28 days of age, of approximately 50MPa. The pipes were divided in six series, being 5 in plain concrete, 5 in reinforced concrete, 10 in concrete reinforced with agglutinated fibers of steel in combs (5 with 20 kg/m3 and 5 with 30kg/m3) and 10 in concrete reinforced with looses fibers (5 with 20kg/m3 and 5 with 30kg/m3). The objective is to evaluate the behavior of those concrete pipes reinforced with fibers of steel, verifying its acting comparatively to pipes of plain concrete and of reinforced concrete, when submitted to the test of diametrical compressive. They were also determined the compressive strenght, to the traction in the compressive diametrical, as well as the flexural toughness to the concretes employees in the production. The accomplished rehearsals demonstrated a ductile behavior of the concrete tubes reinforced with fibers of steel, demonstrating that the substitution of the conventional armors for. the fibers of steel is possible, maintaining the same support capacity, with having won significant of durability / Mestrado / Edificações / Mestre em Engenharia Civil

[pt] Neste trabalho, a propagação de sólitons em fibras óticas é analisada através de simulação numérica da equação não linear de Schrödinger, a qual descreve a propagação de pulsos óticos em fibras monomodo do tipo degrau. Uma vez que soluções analíticas para esta equação só podem ser obtidas em alguns casos específicos, implementaram-se dois métodos numéricos, possibilitando a análise da evolução de diferentes formas de pulsos incidentes ao longo de fibras com propriedades diversas de atenuação, dispersão e não linearidades. O método da propagação de Raios, cujo desempenho mostrou-se superior ao do método da série de Fourier, foi o escolhido para a obtenção dos resultados aqui apresentados. Várias características do sóliton fundamental, dos sólitons de ordens superiores, dos sólitons escuros e do fenômeno da interação entre pulsos adjacentes são apresentadas e discutidas, levando-se em consideração as possíveis implicações no desempenho de sistemas óticos. Contrabalançando os efeitos da dispersão da fibra com os efeitos não lineares da automodulações de fase, o que permite sua propagação sem alteração de forma, os sólitons encontram potencial aplicação na transmissão de altas taxas a longas distâncias. / [en] In this work, soliton propagation in optical fibres is analysed by means of numerical simulation of the nonlinear Schrödinger equation, which governs optical pulse propagation in step-index monomode fibres. Since analytic solutions to this equation are admitted only for some specific cases, two numerical methods have been implemented in order to study the evolution of different kinds of input pulses, under the effects of attenuation, dispersion and nonlinearities. Showing a better performance than the Fourier Series Method in a comparative test, the Beam Propagation Method has been chosen to obtain the results here presented. Many characteristics of the fundamental, higher order and dark solitons, as well as interaction phenomena between adjacent pulses, are investigated, taking into account possible implications on optical systems performance. By properly counteracting the effects of fibre dispersion and nonlinearities, solitons can propagate without changing its shape, finding potential application in high bit-rate long distance optical communication systems.

M.Ing. / This thesis is about the gain equalization of erbium doped fibre amplifiers (EDFA), which is a key technology for enabling wavelength-division multiplexed (WDM) optical communication systems. In order to flatten dynamically the EDFA gain spectrum, a tuneable long-period grating filter was demonstrated. Long-period gratings were fabricated by using a KrF excimer laser combined with the metal amplitude mask technique. The transmission spectrum characteristic of the long- period grating was simulated theoretically by the coupled-mode theory. The coupling between the core and cladding modes of the long-period grating was investigated both experimentally and theoretically. The EDFA was constructed by using the forward pumping configuration consisting of pump laser source, WDM couplers, an optical isolator, and the erbium-doped fibre. The EDFA was characterized theoretically and experimentally for WDM applications. The tuneable long-period grating filter design is based on the tuneable coupler that uses the Mach-Zehnder interferometer configuration. The tuneable filter was demonstrated by equalizing the EDFA gain spectrum and the amplified spontaneous emission (ASE) source. The main advantage of this filter compared to other optical filters is its tuneability of the attenuation over a wide range of pump power.

M.Ing. / Lightwave systems used in the core transport network of telecommunication systems operate in the second transmission window. The 1550 nm wavelength region exhibits the lowest attenuation coefficient, thus expanding the repeater distance in the network. However, the influence of the large dispersion coefficient associated with the second transmission window limits the operating speed of the network to 2.5 Gbit/s or less. In order for the network to operate at higher bit-rate, a dispersion management scheme is needed. In this research, the performance of negative dispersion fibre used as a dispersion compensating module is investigated. The negative dispersion fibre used in this study was the AVANEX PureForm DCM. The dispersion coefficient of the DCM measured at 1525 nm, 1545 nm and 1565 nm were given as -918 , -987 and -1047 respectively. The optimal operating condition of the DCM was obtained by considering various dispersion management configurations i.e. post-compensation, pre-compensation and symmetric compensation. The DCM was tested on a single span, single channel system operating at a speed of 10 Gbit/s with the transmitting wavelength of 1551.2 nm, over 60 km of convention single mode fibre. Furthermore, the performance of the system at 55 km and 65 km were also used to examine the results for the over- and under compensation links respectively. The results obtained for 100% dispersion cancellation for the pre-, post- and symmetric configuration showed an increase in the extinction ratio of 2.09 dB, 2.72 dB and 2.37 dB respectively. Similarly, the Q-factor was estimated to equal 13.67, 11.296 and 13.167 respectively. The results indicate similar performance for all the configurations considered, analysis of the eye-diagrams reveals that the post-compensation configuration would ultimately yield the best results. This is due to the fact that eye diagram recovered from this setup has minimal deformation. The experiments for an extremely over-compensated link, i.e. 40 km, showed an increase from 9.49, obtained with no compensation, to 10.63. However, for the extremely under-compensated link i.e. 80 km, the extinction ratio only manages to improve from 4.88 dB to 8.63 dB.

M.Ing. / Bragg gratings exist due to permanent changes in the refractive index introduced in the fibre through exposure to ultraviolet radiation. Standard telecommunications fibre (SMF-28) is only slightly photosensitive at 248 nm irradiation. A comparative study of different photosensitization techniques is undertaken on the basis of the desired photosensitivity characteristics and efficiency of the technique used. The analytical method is used to determine valuable properties of fibre Bragg gratings. The bandwidth and maximum reflectivity of the fibre Bragg grating is dependant on the change of refractive index and is determined analytically. Obtaining very high reflectivity and bandwidth (~lnm) can only be achieved with highly photosensitive optical fibre where refractive index changes of~ 1 o-3 are possible. The change of the refractive index in the optical fibre is related to the phase change by: A new interferometric measurement technique based on this assumption allows the direct measurement of photosensitivity. This technique is modelled with a modified Layer Peeling algorithm. Standard telecommunications fibre was exposed to high-pressure (26B - 160B) hydrogen for several days. This increased the photosensitivity of the optical fibre significantly. The photosensitivity of the fibre is directly dependent on the hydrogen concentration inside the fibre. Refractive index changes, M ~ 1.3x10-3 were achieved in germanium doped fibre and M ~ 5x10-3 in germanium/boron codoped fibre. The knowledge of the hydrogen concentration inside the fibre is important in studying photosensitivity, transmission losses and the wavelength drift after Bragg grating manufacturing. The diffusion proceeds interstitially with no significant chemical interaction. A hydrogen diffusion model was developed based on the transfer of heat between two objects. Although the photosensitivity phenomenon was discovered in optical fibre more than 20 years ago, no complete physical explanation exist for it at present. We agree that stress relaxation and/or compaction are the main reasons for photosensitivity in optical fibre but also that it is still a complex and multifaceted phenomenon. A study of the thermal decay of fibre Bragg gratings suggests that fibre Bragg gratings written in hydrogen loaded fibre is less thermally stable than gratings written in germanium doped fibre. The analysis of accelerated ageing will predict the thermal stability of the Bragg grating over time.

M.Ing. / Bragg gratings are important components for sensing and for wavelength-division multiplexed optical communication systems. These gratings are manufactured by either side-writing of the fiber with a high intensity UV light through a phase mask, or by exposing the fiber to interference fringes through an interferometer arrangement. With one phase mask, only a small range of grating wavelengths is possible. This is achieved by pre-straining the fiber during the writing process. The limitation arises from the break strength of the fi ber, allowing a maximum range of Bragg wavelengths of only approximately 10 nm. The interferometric technique uses a beam splitter to divide a single input UV beam into two and intersecting them at the fiber. The angle at which the beams intersect will determine the period of the interference fringes and thus the Bragg grating written in the optical fiber. The Argon-ion laser is used with a 1060 nm phase mask (used to split beam) to write Bragg gratings with reflections from 1012 to 1600 nm. Three accurate- translation and rotation stages are used to keep the fiber at the beam intersection. Alignment, mechanical stability and coherence of laser are critical.

M.Phil. / Linearly chirped fibre Bragg gratings can be used to compensate dispersions in a fibre transmission system. Various methods have been developed to chirp fibre gratings. It is proposed that a uniform period grating can be chirped by applying an axially linear strain gradient. In this project, we shall demonstate a novel method for making chirped fibre Bragg gratings, which involves bonding an unchirped fibre Bragg grating of 5cm length to the surface of a tapered stainless steel plate which is strained by bending or dilating. This allows a strain gradient to be formed along the grating length through the transferring of strains from the plate to the fibre. The profiles of tapered stainless steel plates have been determined by means of the finite element method and computer simulations to establish the strain gradient during loading. Ten conventional resistive strain gauges are also bonded on the other surface for strain measurements. Because of the strain gradient, the local Bragg wavelength is a function of the position along the length of the fibre grating so that the grating chirp is an automatic consequence of the strain gradient. This method provides the dynamic control of Bragg wavelength shift, peak reflectivity and spectral bandwidth, and its tunability is also suitable for optimising pulse compression and optical fibre dispersion compensation. Using couple-mode equations, we have also calculated the reflection response of a chirped fibre grating. It is shown that the close agreement between the theoretical and the experimental results suggests that the strain gradient technique provides good control of the Bragg grating chirp and the center wavelength of a chirped fibre Bragg grating.

M.Ing. / Long distance optical communication systems experience a large degree of attenuation due to fibre losses, necessitating signal amplification. Erbium Doped Fibre Amplifiers (EDFAs) have found widespread use as all-fibre optical amplifiers, but exhibit unequal amplification of different wavelengths. Since the gain spectrum is signal-power and pump-power dependent, each EDFA spectrum may differ considerably, and a tuneable gain equalizer is required. A tuneable long-period grating (LPG) can be implemented as a gain equalizer for EDFAs. This dissertation deals with the design of an integrated optic version of the tuneable equalizing filter. The various components of which the device comprises, including optical couplers, Mach-Zehnder interferometers and an LPG, are investigated. The integrated optics designs of these components are then done using the BeamPROP software package. The use and optical properties of germania-doped silica as photosensitive waveguide material is studied. The production of the films for the gain equalizer, using electron-cyclotron resonance plasma-enhanced chemical vapour deposition, is discussed. Characterization of these films was carried out using spectroscopic ellipsometry and infrared spectroscopy. The optical constants, thickness, germania content and hydroxyl absorption was calculated using these measurements.