Propriedades cerâmicas e imobilização do manganês em cerâmica estrutural

In this work is the addition of a metallic ion, of the metal Manganese, in a clay of Rio Grande do Norte state for structural ceramics use, the objective this study was to assess the evolution of ceramic properties. The clay was characterized by Chemical and Thermal analysis and Xray difraction. The metallic ion was added in the clay as aqueous solutions at concentrations of 100, 150 and 200 mg / L. The molded by extrusion and the burned were temperatures at 850, 950, 1050 and 1150 º C. Was made Chemical Analysis and investigated the following parameters environmental and ceramic: Solubility, Colour, Linear Retraction (%), Water Absorption (%), Gresification Curves, Apparent Porosity (%), Apparent Specific Mass (g/cm3) and Flexion Rupture Module (kgf/cm2). The results showed that increasing the concentration of metallic ion, properties such as Apparent Porosity (%), Water Absorption (%) decreases and the Flexion Rupture Module (kgf/cm2) increases with increasing temperature independent of the concentration of the ion. The gresification curves showed that the optimum firing temperatures were in the range between 950 and 1050 ° C. The evaluation of the properties showed that the ceramic material can be studied its use in solid brick and ceramic materials with structural function of filling. The results of solubility showed that the addition of ion offers no risk to the environment

Nano emulsões aplicadas a recuperação avançada de petróleo

A exploração de petróleo está a cada dia em circunstâncias mais adversas, no que diz respeito à profundidade dos poços como também, em relação à fluidez do óleo. Os reservatórios de descobertas recentes não possuem energia própria para produzir ou os métodos convencionais não são eficientes para fazer com que esses reservatórios tenham uma vida útil elevada, devido a alterações das propriedades físico-químicas, como por exemplo a viscosidade, que torna o deslocamento do óleo pelos poros do reservatório até a superfície cada vez mais complexo. O presente trabalho tem como objetivo estudar a preparação, caracterização e a utilização de nanoemulsões obtidas a partir de sistemas microemulsionados, com e sem a presença de polímero. Esses sistemas foram aplicados como método químico de recuperação de petróleo, com o intuito de obter maior eficiência de volume de óleo deslocado. O interesse por esse tipo de sistema existe devido a sua baixa tensão superficial, o pequeno tamanho de gotícula e, principalmente, pelo baixo percentual de matéria ativa presente em sua composição. Os ensaios realizados para caracterizar esses sistemas foram: aspecto físico, medidas de tamanho de gotícula, índice de polidispersão, tensão superficial, pH e condutividade. Ensaios de reologia e de adsorção dos sistemas foram realizados com o objetivo de avaliar sua influencia na recuperação de petróleo. Os ensaios de recuperação foram realizados em um equipamento que simula as condições de um reservatório de petróleo, utilizando plugs de rocha arenito Botucatu. Esses plugs foram saturados com salmoura (KCl 2%) e com petróleo proveniente da Bacia Potiguar do campo de Ubarana. Após essas etapas foi realizada a recuperação convencional utilizando a salmoura e, por último, foi injetada, a nanoemulsão, como método de recuperação avançada. Os sistemas obtidos variaram de 0% à 0,4% de polímero. Os ensaios de tamanhos de partícula obtiveram como resultado uma variação de 9,22 a 14,8 nm, caracterizando que as nanoemulsões estão dentro da faixa de tamanho inerente a esse tipo de sistema. Para ensaios de tensão superficial os valores foram na faixa de 33,6 a 39,7 dynas/cm, valores semelhantes à microemulsões e bem abaixo da tensão superficial da água. Os resultados obtidos para os valores de pH e condutividade se mantiveram estáveis ao longo do tempo de armazenamento, essa avaliação indica estabilidade das nanoemulsões estudadas. O teste de recuperação avançada utilizando nanoemulsão com baixo percentual de matéria ativa obteve como resultado de eficiência de deslocamento 39,4%. Porém esse valor foi crescente, de acordo com o aumento do percentual de polímero na nanomeulsão. Os resultados de eficiência de deslocamento de petróleo estão diretamente relacionados com o aumento da viscosidade das nanoemulsões. A nanoemulsão V (0,4% polímero) é o sistema mais viscoso dentre os analisados, e obteve o maior percentual de óleo deslocado (76,7%), resultando na maior eficiência de deslocamento total (90%). Esse estudo mostrou o potencial de sistemas nanoemulsionados, com e sem polímeros, na recuperação avançada de petróleo. Eles apresentam algumas vantagens com relação a outros métodos de recuperação avançada, como: o baixo percentual de matéria ativa, baixo índice de adsorção do polímero, dissolvido em nanoemulsão, na rocha e alta eficiência de recuperação

Levantamento e avaliação de critérios para a ampliação de escala da produção de biossurfactantes utilizando melaço como substrato

Biosurfactants are amphiphilic molecules synthesized by microorganisms such as bacteria, yeast or filamented fungi cultivated in various carbon sources among sucrose and hydrocarbons. These molecules are composed by a hydrophilic and hydrophobic part. They operate mostly at interfaces of fluids of different polarities. Because of this characteristic, they are potentially employed in numerous industries, such as the textile, medical, cosmetics, food and mainly in the petrochemical ones. Therefore industry has interest in developing new biosurfactant production processes in high scale, in order to become them economically competitive when compared to synthetic biosurfactants. This work aims to evaluate the biosurfactant production applying a non-conventional substrate sugar cane molasses proceeding from the sugar industry thus reducing the production costs. The strain identified as AP029/GLIIA, isolated from oil wells in Rio Grande do Norte state and used in these experiments belongs to the culture collection of Antibiotics Department of UFPE. The fermentation were carried out using different conditions according to a factorial planning 24 with duplicate at center point, in which the studied factors were molasse concentration, nitrate concentration, agitation and aeration ratio. The experiments were performed in a shaker at 38ºC of temperature. Samples were withdrawn in regular periods of time of up to 72 hours of fermentation in order to analyze substrate consumption, cellular concentration, superficial tension, critical micelle dilution (CMD-1 e CMD-2) as well as extracelullar protein production. The results showed a production of 3,480 g/L of biomass, a reduction of 41% on superficial tension, 67% of substrate consumption and 0,2805 g/L of extracellular protein

Estudo de uma coluna de absorção recheada para desidratação do gás natural utilizando microemulsão como absorvente

During natural gas processing, water removal is considered as a fundamental step in that combination of hydrocarbons and water favors the formation of hydrates. The gas produced in the Potiguar Basin (Brazil) presents high water content (approximately 15000 ppm) and its dehydration is achieved via absorption and adsorption operations. This process is carried out at the Gas Treatment Unit (GTU) in Guamaré (GMR), in the State of Rio Grande do Norte. However, it is a costly process, which does not provide satisfactory results when water contents as low as 0.5 ppm are required as the exit of the GTU. In view of this, microemulsions research is regarded as an alternative to natural gas dehydration activities. Microemulsions can be used as desiccant fluids because of their unique proprieties, namely solubilization enhancement, reduction in interfacial tensions and large interfacial area between continuous and dispersed phases. These are actually important parameters to ensure the efficiency of an absorption column. In this work, the formulation of the desiccant fluid was determined via phases diagram construction, employing there nonionic surfactants (RDG 60, UNTL L60 and AMD 60) and a nonpolar fluid provided by Petrobras GMR (Brazil) typically comprising low-molecular weight liquid hydrocarbons ( a solvent commonly know as aguarrás ). From the array of phases diagrams built, four representative formulations have been selected for providing better results: 30% RDG 60-70% aguarrás; 15% RDG 60-15% AMD 60-70% aguarrás, 30% UNTL L60-70% aguarrás, 15% UNTL L60-15% AMD 60-70% aguarrás. Since commercial natural gas is already processed, and therefore dehydrated, it was necessary to moister some sample prior to all assays. It was then allowed to cool down to 13ºC and interacted with wet 8-12 mesh 4A molecular sieve, thus enabling the generation of gas samples with water content (approximately 15000 ppm). The determination of the equilibrium curves was performed based on the dynamic method, which stagnated liquid phase and gas phase at a flow rate of 200 mL min-1. The hydrodynamic study was done with the aim of established the pressure drop and dynamic liquid hold-up. This investigation allowed are to set the working flow rates at 840 mL min-1 for the gas phase and 600 mLmin-1 for the liquid phase. The mass transfer study indicated that the system formed by UNTL L60- turpentine-natural gas the highest value of NUT

Estudo da produção de biossurfactantes sintetizados por Pseudomonas aeruginosa AP029-GVIIA utilizando manipueira como fonte de carbono

This study evaluates the biosurfactants production from cassava wastewater, an agro industrial residue, to be used as carbon source. Using a factorial design 24-1 (half fraction), 10 tests were performed using Pseudomonas aeruginosa AP029/GVII-A in submerged batch cultivation in rotating incubator (shaker). The influence of factors (temperature, agitation, aeration ratio and concentration of cultivation medium) at two different levels for the synthesis of the biosurfactant. Samples were collected throughout the cultivation by 132 hours of fermentation were completed. The best outcome was intended by following production through substrate consumption, dry matter, reduction of surface tension (ring method) and emulsification index. The kinetics of microorganism was assessed for the carbon source used. The results showed that the cassava wastewater is a well assimilable substrate for the production of biotensoactive, reaching 91 % of consumption by the micro-organism under study. The growth temperature was found to be one of the leading factors in the synthesis of the metabolite, followed by aeration and also due to the agitation. The best results showed a 30 % reduction in surface tension (% RTS) for the environment, reaching values of 30 mN/m; 3.0 g /L of biomass and emulsifying index greater than 65 %. The metabolite synthesized still remained stable for different salt concentrations (1, 5 and 10 % w/ v) and alkaline pH (8-10).

Incorporação de resíduo de perfuração em matriz cerâmica: estabilização por solidificação

One of the waste generated during the drilling of oil wells are gravel which are impregnated of drilling fluid. This residue consists of highly toxic chemicals, including toxic metals. This study suggests an alternative process to the treatment of this waste, by incorporating it the form of raw material in the ceramic matrix , and by solidification and stabilize the metals present, Aluminum (Al), Iron (Fe), Manganese (Mn) and Zinc (Zn). The raw materials were characterized by the techniques of X ray fluorescence (FRX), X ray diffraction (DRX), laser granulometry (GL), thermogravimetry (TG) and differential thermal analysis (ADT). To evaluate the percentage of gravel effect the environmental and technological properties were obtained from formulations containing 0, 10 and 20 % by weight of gravel in the ceramic matrix. After sintering at temperatures 1080, 1120 and 1160 °C, the samples were tested for water absorption, the linear shrinkage firing, voltage of rupture and solubility. The results obtained showed that the stabilization by solidification, is a viable alternative to safe disposal of waste drilling. Ceramics products can be used in the manufacture of solid bricks

Síntese e caracterização de tensoativos e estudo de equilíbrio de fase dos sistemas CnH2n+2/H2O/CnH2n+1COONa/But-OH

The growing utilization of surfactants in several different areas of industry has led to an increase on the studies involving solutions containing this type of molecules. Due to its amphiphilic nature, its molecule presents one polar part and one nonpolar end, which easily interacts with other molecules, being able to modify the media properties. When the concentration in which its monomers are saturated, the airliquid system interface is reached, causing a decrease in interfacial tension. The surfactants from pure fatty acids containing C8, C12 and C16 carbonic chains were synthesized in an alcoholic media using sodium hydroxide. They were characterized via thermal analysis (DTA and DTG) and via infrared spectroscopy, with the intention of observing their purity. Physical and chemical properties such as superficial tension, critical micelle concentration (c.m.c), surfactant excess on surface and Gibbs free energy of micellization were determined in order to understand the behaviour of these molecules with an aqueous media. Pseudo-ternary phase diagrams were obtained aiming to limit the Windsor equilibria conditions so it could be possible to understand how the surfactants carbonic chain size contributes to the microemulsion region. Solutions with known concentrations were prepared to study how the surfactants can influence the dynamic light scattering spectroscopy (DLS) and how the diffusion coefficient is influenced when the media concentration is altered. The results showed the variation on the chain size of the studied surfactant lipophilic part allows the conception of surfactants with similar interfacial properties, but dependent on the size of the lipophilic part of the surfactant. This variation causes the surfactant to have less tendency of microemulsionate oil in water. Another observed result is that the n-alcanes molecule size promoted a decrease on the microemulsion region on the obtained phase diagrams

Caracterização do comportamento geotécnico de mistura de resíduo de pneus e solo laterítico

A technological alternative for the correct disposal of tires is the use in the construction of embankment with soil and shredded tires. The use of waste tires in tropical soils requires prior knowledge of the properties and limitations of these materials. In this work, the results of an experimental program was devised to characterize the behavior of mixtures of waste tires and a lateritic soil. The residue used in this study is classified as tire buffings with an average size of 1.4 mm. The laboratory program included testing of particle size analysis, Atterberg limits, compaction, direct shear tests, permeability and confined compression tests with pure soil, pure tire and the mixtures. Proportions of 0% (pure soil), 10%, 20%, 40%, 50 % and 100% (pure tire) by weight were used. For the confining stress levels used in the study, the presence of tire residue provided a considerable increase in shear strength of the mixture. The maximum shear strength was obtained for a residue content of 40% by weight. Permeability tests on samples of waste under a confining stress of 100 kPa showed that the permeability increases significantly with increasing residue content until a residue content of 20%. The increase in permeability after that value showed to be negligible. Confined compression tests showed that the soil mixed with tire residue becomes more compressible than the pure soil. The secant constrained modulus (Msec) for the same vertical stress decreases with increasing percentage of residue.

O trágico em lavoura arcaica

El escritor de São Paulo Raduan Nassar, lanza en 1975, su primera novela intitulado Lavoura arcaica. En su narrativa de estreno, el escritor nos trae la historia de un adolescente, André, que intenta destruir la plantación de su padre, Iohána. A través de sus sermones, el patriarca predicaba la moderación, la disciplina y la obediencia a las leyes impuestas por él, construyendo así, un mundo de ilusiones, donde el amor era una máscara para la hipocresía. En esta tensa relación, padre e hijo, representaciones místicas de Apolo y Dionisio, emprenden una contienda discursiva sobre la negación y la afirmación de la existencia. De ese modo, considerando la relación de lucha e integridad entre el impulso apolíneo y dionisiaco existentes en el romanticismo nassariano, la propuesta de este trabajo es presentar una lectura de lo trágico en Lavoura arcaica a partir de la perspectiva nietzscheana sobre el género trágico. Para eso, recorrimos al concepto desarrollado por Nietzsche en su obra, desde su primer libro O nascimento da tragédia (2007a), A visão dionisíaca do mundo (2005 a) y Ecce homo (2008 b).

A linguagem do blog escolar em um trabalho com multiletramentos: compartilhando sentidos

This research, part of Applied Linguistics field, aims to analyze the language of a school blog, developed with the participation of students, as a work based on the conception of multiliteracies, focusing on the construction of different meanings. The research is carried on from the building and maintenance of a school blog, the Ieceblog, with students of Ensino Fundamental II, since 2008, in a private school in Natal-RN. The investigation of the language produced on a school blog is justified due to the interactive conceptions of writing and reading on the virtual environment. Given the fact that new technologies are a reality in the schools opened to the practices of multiliteracies, it is assumed that text, image, video, audio, non-graphic signs and hypertext intensifies the produced interaction, in which the students become real authors. In this perspective, some voices belonging to the statements that are formed through the posts and comments chosen to the analyses and reflection on the blog space as locus of productions of senses inserted in the school and the world environment, as well as for the identification of the language resources used to intensify the senses that emerge from it. From the view of dialogism conceptualized by Bakhtin Circle, the qualitative interpretive-research deepens the experience of a school blog focusing on digital language in line with the vision of digital literacy. From the blog posts, a corpus that promote the exposure of different manifestations of language in the design of digital multiliteracies is elected. Thereby, the method used was the dialogical analysis of speech based on Bakhtin s studies and the Circle. The corpus was taken from the blog s posts in order to point up the different language manifestations in the following categories: (i) mood reinforced by the mockery, (ii) search for compliance with school sphere, (iii) conflicting social values and consistent complicity between sense and verbal imagery, and finally (iv) social practices that take place from and through the discursive genre. The study points to the tension between the active voices in several directions, revealing the distorted unit of posts which, under the analytical observation raises multiple meanings in a responsive manner. The analysis of the dialogue interaction in which intersperses the digital one becomes more apparent that the multiliteracies events that are mediated by language in addition to structure of the language and makes us rethink the students

O discurso do grotesco na mídia digital

This study presents our research on the discourse of the grotesque in digital media, specifically in two blogs. We rely on the theoretical-conceptual and methodological discourse analysis of the French School. We analyzed a set of posts in the following blogs: Eu Sou Ryca and Cleycianne, and we did it based on some propositions on the discourse of the grotesque by Mikhail Bakhtin (1999a), Muniz Sodré and Raquel Paiva (2002), Wolfgang Kayser (2003) and Mary Russo (2000). The expressions of the grotesque analyzed in the blogs Eu Sou Ryca and Cleycianne result predominantly in humorous effect, obtained by means of irony and parodization, which calls for ridicule and relegation, through a strong tension between the beautiful and the ugly, the socially acceptable and the aberration, the taste for the strange and the aesthetically striking. The grotesque appears initially as a significant feature of ornamental paintings found in Roman caves in the late fifteenth century, and today it can be seen permeating from sculptures, paintings, literary works, talk shows for television, videos hosted in cyberspace, specifically in the collective domain of weblogs. This work seeks to analyze how the discourse of the grotesque constitutes the humorous process in its insertion in cyberspace

Modos de ler, formas de escrever a literatura enquanto objeto da ficção de Enrique Vila-Matas

Este trabajo busca analizar cómo algunos aspectos presentes en la obra de ficción del escritor catalán Enrique Vila-Matas permiten pensar las prácticas de la escritura literaria contemporánea. A partir de una forma híbrida que reconsidera las relaciones tanto entre los géneros como entre los discursos crítico y de ficción, la obra del autor se propone reflexionar sobre sus propias posibilidades en el contexto sociocultural contemporáneo. De este modo, a través de una ficción que muchas veces adquiere los atributos del ensayo, Vila-Matas trae al centro de sus enredos la discusión de cuestiones relacionadas con los impases de una escritura que vuelve su atención para el destino de una tradición literaria desvinculada de los preceptos meramente mercadológicos contemporáneos. Su manera crítica de abordar la literatura y la experimentación en busca de nuevas posibilidades permite asociarlo tanto a Laurence Sterne como al proyecto literario de Jorge Luis Borges. Estos autores tienen propuestas que tratan de superar los límites del texto, ya que ahí está el deseo de acogerse a la ficción para demostrar la inestabilidad de los elementos de una cultura, apropiándose y desestabilizando los discursos y las claras distinciones entre los saberes. En este sentido, las diversas formas en que Vila- Matas se apropia de los textos de otros y construye una obra de carácter fuertemente intertextual denuncian jerarquizaciones y modos de circulación de textos que permiten aproximarse de la tensión existente entre temas como influencia, citación, prácticas de lectura y escritura

Plano Nacional de Saúde e o lugar social em disputa

O presente artigo apresenta uma análise do Plano Nacional de Saúde publicado em 2004. Este documento expressa um importante período de transição na gestão do SUS, uma vez que foi predecessor do Pacto pela Saúde. A partir de um estudo descritivo com base em procedimentos quantitativos e qualitativos, o objetivo foi compreender as ideias centrais do documento, identificando as conexões existentes entre seus princípios, objetivos e prioridades. O principal resultado do estudo foi a identificação da integralidade das ações, da capacitação dos recursos humanos e mudança do marco regulatório com base numa visão intersetorial como núcleo central do documento. Essas ideias, por sua vez, circulam pelo discurso das diretrizes do plano, fortalecendo os laços do eixo central do texto na reorganização da atenção ambulatorial e na qualificação profissional. Por fim, quando comparadas metas e ações previstas nas diretrizes, observa-se uma tensão entre o que foram denominados vetores da verticalidade e da horizontalidade, deixando em aberto o rumo do lugar social em disputa.

Práticas discursivas em blogs políticos: uma observação sobre a participação política e as trasnformações que acompanham o espaço público

This work discuss about the transformation of public space, based on the recent challenges imposed by communication practices that are renewed and recopying of the sociocultural contexts of everyday life. The study presents theoretical and empirical reports of regional political blogs. In this issue, it looks for understand the political participation in the Internet space, examining the reconfigurations that accompany social relations and new forms of interaction that are merged in the media scene. The ambience of the study limits comments of readers in two political blogs in Rio Grande do Norte, Território Livre, and Thaisa Galvão. The observation concerns about the democratic participation of citizens in matters of collective interest, during the 2010 election. The analysis update the debate on democratic discussion and conversation everyday, trying to grasp changes in social practices in virtual platforms. From this perspective, the work restores some conceptual notions that involve the public places, identifying the changes that appear in the virtual and traditional spheres, with the emergence of new places of conversations, from the Internet usage. Are also compared to similarities and differences between the two elements of the analysis. It is possible, therefore, the communication process of the two discursive spaces with ideas from the public sphere, trying to analyze the duality between public, private, and political participation in these virtual places

A ontologia da cor na fenomenologia estética bachelardiana

La philosophie de Gaston Bachelard se fonde sur une tension ontologique, qui comprend tant la Science que la poétique, et au cours de cette recherche, se développe par la compréhension de la possibilité d envisager une ontologie de la couleur, expression de Bachelard ci tée en «Le Droit de Rêver». Nous suivons, donc, face au dialogue ent re la science et la poésie tout en établissant des paramèt res afin d élucider, d un côté, la couleur conceptuelle de la science qui ne matise pas seulement les objets par le biais de l expérience chimico-physique, mais établit aussi dans la relat ion ent re l observateur et l objet une compréhension de l existence de la couleur invisible, celle qui habite l imagination créatrice et apparaît comme un type d ontologie de la couleur. Dans ce sens, la couleur est une image qui naît dans la conscience de l homme, comme un produit direct de l âme dans son actualité même. Ainsi, la couleur serait dans l imagination créative une image autogène desti tuée de substantialité