Avaliação e modelagem da absorção de H2S do gás natural em coluna de leito estagnado

Natural gas, although basically composed by light hydrocarbons, also presents contaminant gases in its composition, such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). The H2S, which commonly occurs in oil and gas exploration and production activities, causes damages in oil and natural gas pipelines. Consequently, the removal of hydrogen sulfide gas will result in an important reduction in operating costs. Also, it is essential to consider the better quality of the oil to be processed in the refinery, thus resulting in benefits in economic, environmental and social areas. All this facts demonstrate the need for the development and improvement in hydrogen sulfide scavengers. Currently, the oil industry uses several processes for hydrogen sulfide removal from natural gas. However, these processes produce amine derivatives which can cause damage in distillation towers, can cause clogging of pipelines by formation of insoluble precipitates, and also produce residues with great environmental impact. Therefore, it is of great importance the obtaining of a stable system, in inorganic or organic reaction media, able to remove hydrogen sulfide without formation of by-products that can affect the quality and cost of natural gas processing, transport, and distribution steps. Seeking the study, evaluation and modeling of mass transfer and kinetics of hydrogen removal, in this study it was used an absorption column packed with Raschig rings, where the natural gas, with H2S as contaminant, passed through an aqueous solution of inorganic compounds as stagnant liquid, being this contaminant gas absorbed by the liquid phase. This absorption column was coupled with a H2S detection system, with interface with a computer. The data and the model equations were solved by the least squares method, modified by Levemberg-Marquardt. In this study, in addition to the water, it were used the following solutions: sodium hydroxide, potassium permanganate, ferric chloride, copper sulfate, zinc chloride, potassium chromate, and manganese sulfate, all at low concentrations (»10 ppm). These solutions were used looking for the evaluation of the interference between absorption physical and chemical parameters, or even to get a better mass transfer coefficient, as in mixing reactors and absorption columns operating in counterflow. In this context, the evaluation of H2S removal arises as a valuable procedure for the treatment of natural gas and destination of process by-products. The study of the obtained absorption curves makes possible to determine the mass transfer predominant stage in the involved processes, the mass transfer volumetric coefficients, and the equilibrium concentrations. It was also performed a kinetic study. The obtained results showed that the H2S removal kinetics is greater for NaOH. Considering that the study was performed at low concentrations of chemical reagents, it was possible to check the effect of secondary reactions in the other chemicals, especially in the case of KMnO4, which shows that your by-product, MnO2, acts in H2S absorption process. In addition, CuSO4 and FeCl3 also demonstrated to have good efficiency in H2S removal

Equilíbrio líquido-líquido de sistemas aquosos com tensoativos polietoxilados: dados experimentais e modelagem

The nonionic surfactants when in aqueous solution, have the property of separating into two phases, one called diluted phase, with low concentration of surfactant, and the other one rich in surfactants called coacervate. The application of this kind of surfactant in extraction processes from aqueous solutions has been increasing over time, which implies the need for knowledge of the thermodynamic properties of these surfactants. In this study were determined the cloud point of polyethoxylated surfactants from nonilphenolpolietoxylated family (9,5 , 10 , 11, 12 and 13), the family from octilphenolpolietoxylated (10 e 11) and polyethoxylated lauryl alcohol (6 , 7, 8 and 9) varying the degree of ethoxylation. The method used to determine the cloud point was the observation of the turbidity of the solution heating to a ramp of 0.1 ° C / minute and for the pressure studies was used a cell high-pressure maximum ( 300 bar). Through the experimental data of the studied surfactants were used to the Flory - Huggins models, UNIQUAC and NRTL to describe the curves of cloud point, and it was studied the influence of NaCl concentration and pressure of the systems in the cloud point. This last parameter is important for the processes of oil recovery in which surfactant in solution are used in high pressures. While the effect of NaCl allows obtaining cloud points for temperatures closer to the room temperature, it is possible to use in processes without temperature control. The numerical method used to adjust the parameters was the Levenberg - Marquardt. For the model Flory- Huggins parameter settings were determined as enthalpy of the mixing, mixing entropy and the number of aggregations. For the UNIQUAC and NRTL models were adjusted interaction parameters aij using a quadratic dependence with temperature. The parameters obtained had good adjust to the experimental data RSMD < 0.3 %. The results showed that both, ethoxylation degree and pressure increase the cloudy points, whereas the NaCl decrease

Variação da qualidade da água do escoamento superficial de duas bacias de drenagem de Natal/RN - Brasil

The urban drainage is one of the powers of environmental sanitation and its scope is the quantitative and qualitative aspects. In decision making of managers and the engineering aspects of design are almost always taken into account only the quantitative aspects. However, the waters of the runoff have the highest concentrations of pollutants at the beginning of precipitation. Thus, if the plot pollution removed, the remaining portion can be used for other purposes. This work has aimed to present the variation of water quality of two drainage basins in the city of Natal / RN-Brazil to support the implementation of drainage to consider the qualitative aspect, and identify potential for the use of water. The basins (M and C) are analyzed closed-type, are in the urban area, are predominantly residential occupation and its waters are used for detention ponds and infiltration. The samples were divided into three phases, the first two direct to final points in a basin and the third in traps distributed over the surface drainage. The parameters had been analyzed were pH, conductivity, dissolved oxygen, Color, Turbidity, COD, Ammonia, nitrite, nitrate, total phosphorus, orthophosphate, Sediments solids, total solids, chloride, sulfate, alkalinity, calcium, magnesium, sodium, potassium, Heavy Metals (Chromium, Cadmium, Lead, Zinc and Copper), Eschichia coli and total coliforms. The parameters studied showed high initial pollution load, events and located in different proportions, except nitrite, heavy metals and biological indicators. The size of the surface drainage and topographic its features influence the quality of water. However, the form of sampling is crucial in the qualitative study in the basin. The samplers developed at work, were generated economic and representative results. The urban rainwater presents organic faecal indicators. The runoff of water from both basins shows no risk of salinity and sodicity for use in irrigation, should be noted the content of chloride in the choice of method of irrigation

Estudo de manejo de águas pluviais urbanas na cidade Natal-Rio Grande do Norte

Urban stormwater can be considered as potential water resources as well as problems for the proper functioning of the manifold activities of the city, resulting from inappropriate use and occupation of the soil, usually due to poor planning of the occupation of the development areas, with little care for the environmental aspects of the drainage of surface runoff. As a basic premise, we must seek mechanisms to preserve the natural flow in all stages of development of an urban area, preserving the soil infiltration capacity in the scale of the urban area, comprising the mechanisms of natural drainage, and noting preserving natural areas of dynamic water courses, both in the main channel and in the secondary. They are challenges for a sustainable urban development in a harmonious coexistence of modern developmental, which are consistent with the authoritative economic environmental and social quality. Integrated studies involving the quantity and quality of rainwater are absolutely necessary to achieve understanding and obtaining appropriate technologies, involving both aspects of the drainage problems and aspects of use of water when subjected to an adequate management of surface runoff , for example, the accumulation of these reservoirs in detention with the possibility of use for other purposes. The purpose of this study aims to develop a computer model, adjusted to prevailing conditions of an experimental urban watershed in order to enable the implementation of management practices for water resources, hydrological simulations of quantity and, in a preliminary way, the quality of stormwater that flow to a pond located at the downstream end of the basin. To this end, we used in parallel with the distributed model SWMM data raised the basin with the highest possible resolution to allow the simulation of diffuse loads, heterogeneous characteristics of the basin both in terms of hydrological and hydraulic parameters on the use and occupation soil. The parallel work should improve the degree of understanding of the phenomena simulated in the basin as well as the activity of the calibration models, and this is supported by monitoring data acquired during the duration of the project MAPLU (Urban Stormwater Management) belonging to the network PROSAB (Research Program in Basic Sanitation) in the years 2006 to 2008

A modelagem matemática como alternativa de ensino e aprendizagem da geometria na educação de jovens e adultos

This is work itself insert in the mathematics education field of the youth and adult education to aim to practitioners of the educational action into the mathematics area performing to with this is teaching kind, adopting to as parameter the Mathematics Molding approach. The motive of the research is to draw up a application proposal of the molding mathematics as teaching and learning geometry alternative in the youth and adult education. The research it develops in three class of the third level (series 5th and 6th) of he youth and adults education in the one school municipal from the Natal outskirts. Its have qualitative nature with participating observation approach, once performing to directly in to research environment as a mathematics teacher of those same classes. We are used questionnaires, lesson notes and analyses of the officials documents as an basis of claim instruments. The results indicates that activity used the mathematic moldings were appreciated the savoir-faire of the student in to knowledge construction process, when search develop to significant learning methods, helping to student build has mathematics connections with other knowledge areas and inside mathematics himself, so much that enlarges your understanding and assist has in your participation in the other socials place, over there propitiate to change in student and teacher posture with relation to mathematic classroom dynamics

A formação inicial do professor de química e o uso das novas tecnologias para o ensino: um olhar através de suas necessidades formativas

La disertación, desarrollada en el Programa de PostGraduación en Enseñanza de las Ciencias Naturales y de la Matemática de la UFRN, estudia las necesidades formativas de licenciandos en Química sobre el uso de las nuevas tecnologías de la información y de las comunicaciones (NTIC), en especial, las relacionadas con la utilización de programas computacionales para la enseñanza de la química. En la actual sociedad del conocimiento, se torna imperativo la eclosión de nuevas formas de aprender y de enseñar, que requieren de nuevas concepciones del trabajo pedagógico. En ese sentido, se exige de los profesores el desarrollo de nuevas habilidades y competencias. El presente trabajo está comprometido con la búsqueda de elementos que puedan nortear los procesos formativos de profesores de química con el objetivo de contribuir con una mejor preparación de la formación inicial, tomando en cuenta sus necesidades de formación. Fue utilizado el cuestionario como instrumento de investigación para diagnosticar y caracterizar las necesidades fomativas, buscando establecer correlaciones entre diferentes variables que cacarterizan el estudio, con el fin de establecer semenazas y discrepancias entre las habilidades docentes en estudio y las necesidades formativas. Los analises de los datos tomo elementos de la estadistica descriptivo e inferencial, con analises multivariados, lo que posibilitó identificar las necesidades formativas. Los resultados muestran ue de forma general los licenciandos evaluan como de bajo, el grado de desarrollo de las habilidades para enseñar usando las NTIC, así como manifiestan sentir necesidades formativas en todas las habilidades referentes a esa esfera del trabajo docente

Dificuldades de aprendizagem em estequiometria: uma proposta de ensino apoiada na modelagem

In order to learn/teach chemistry some themes are relevant, like the stoichiometry, which consists in the study of the weight ratios in the combination of elements and compounds between themselves. This is an underlying subject in the understanding/representation/forethought of chemical reactions. Considering these aspects, our study presents a modeling-based proposal to develop the content of stoichiometry with prospective chemistry teachers. With this aim, we have made a review of literature, which we considered when tried to identify the learning difficulties using both quizzes and pedagogical tests, and then, from those difficulties we could propose a teaching unit for this concept and, consequently the evaluation of our proposal. The participants were chemistry undergraduates at the Universidade Federal do Rio Grande do Norte (UFRN) from assorted levels. As a methodological framework, we rely on the discursive textual analysis to characterize the speech of participants. As main results we observed ideas of appearance or disappearance of matter during chemical transformations, disregard of stoichiometric proportions when using drawings to represent the microscopic level of a reaction and confusion between the magnitude amount of matter and other magnitudes such as mass and volume. The final product is a sequence of instruction, based on the modeling previous research literature , with the goal of improving students ability to articulate the macroscopic and submicroscopic levels of representation of the matter

Citação e modernidade em Álvares de Azevedo: do sublime ao dessublime

El estudio de la citación en Lira de los Veinte Años, de Álvares de Azevedo, desde la óptica de Antoine Compagnon e Gerárd Genette, se muestra relevante a los estudios de la Literatura Comparada, en la perspectiva conteporánea, pués el tema provoca la posibilidad de discutir la elaboración de si del(los) otro(s), sucitando imágenes estéticas y de los pensamientos que se aproximan de una noción de tesitura textual muy presente en la modernidad literaria. Este proceso instaura procedimientos de lectura, traducción, autoria y escritura, aún, por ser utilizados, confirman la potencialidad inegable en que se escribi el trabajo poético del escritor. En la primer parte de la obra, se sugieren experiencias com lo bello y lo sublime, advindos del europeu, pero vuelto para una pesquisa de posibilidad discursivas. En la según parte, esa instancia sublimada es puesta en crise, por el sujeto poético cribado por el deseo de tornarse singular. Se instauran en el campo valorativo de los signos románticos elementos desfavorables de sentido diferentes. Dase, así, la problematización puesta por las citaciones que ora, realizan cambios simbólicos, ora, actuan en las márgenes de los textos primeros, desorganizando el material de autoria, desublimandolo, en la irrupción de nuevos cuerpos discursivos y cuerpúsculos cituacionales. En la tecer parte, ligado a Tánatos, como la dimensión por venir, marcando el presentimiento del poeta de que morirá temprano, como también la despedida de él. En esta tesi, se pretende, así, circunscribir como se figura, elabora esa constituición estética azevediana y su escritura, situando cuestiones recortadas por el actor en su obra, las quales remeten a Hegel, Kant y la otras lecturas filosóficas, ali puestas. Tal procedimiento toma la citación como estrategia poética de inscrición del sujeto y de las alteridades que le atravesan, concebiendo eso proceso autoral en la forma de reconstrución de una ciudadela de libros en este aspecto, considerandose el enfoque de Félix Guatarí, la propósito de los nuevos paradigmas y las espacialidades emergentes de estos -, o la biblioteca subjetiva, que se abre en vias y pasagenes. A través de ellas el discurso captura no solamente los objetos poéticos, pero también trazos autobiográficos rasurados, traduciendo la lucha por la visibilidad del sujeto en la formación de su pensamiento poético y estético

Vozes sociais e dimensão ética da lingüística aplicada: a construção discursiva da área nos CBLAs

This research deals with Applied Linguistics and its structure as a scientific field, in compliance with knowledge produced within the range of the Brazilian Congresses of Applied Linguistics (CBLA). The purpose of this research is to understand the meanings disclosed by the voices that make up the scientific discourse on this field, pointing toward its course of development, the ethical position that is peculiar to it and how this position is represented in its scientific practice. The scientific discourse typical of the production of knowledge of Applied Linguistics is now construed as leading to practices that define the production of this field of learning whose object is to study man and man s relationship to language. Theoretical groundwork is anchored on the work the Social Sciences have developed on the paradigmatic crises of science and the social changes resulting from modern and post-modern times, on Applied Linguistics researches on the identity of the field of study, its courses and ethics, and on the bakhtinian theory that supports a view of language as a social practice built under the aegis of the subject s ethics and responsibility. The corpus of this work comprises qualitative and quantitative data made into articles presented at the CBLA. The research methodology conforms to the interpretive paradigm and has the concept of social voices as its category of analysis. Results point towards the progress of Applied Linguistics that, from its role as a mediator discipline between linguistic theory and practical applications, is assuming a position in a field of study of its own, independent, with transdisciplinary characteristics, pursuing through its quests and redefinitions to get closer to the dimension of life and assuming the ethical position of taking on responsibility for its doings and sayings

Produção em revista : Representação do moderno e do regional na experiência potiguar anos 1920

This work brings some reading about a few Norte-rio-grandenses writers collaborations published in literary papers which circulated during the third decade of the twentieth century in Brazil, in a way of enlarging the understanding of how the cultural debate was carried out in the years of the definition of the Brazilian Modernism, based on the relationships between literature and culture. Under the genres of prose and poetry, the selected textual collaborations for analysis have brought the traces of a small group of articulated authors in the Brazilian cultural scenery from the 1920 s, concerning the issues of the modern (linked to the modernist renovation) and the regional (under the aspects of the tradition). The set of the analyzed collaborations is representative of a modern-regional cultural practice marked by a tendency either local or cosmopolitan, thus, sharing a large dimension of the formation of the modern literary tradition, marked by different kinds of practices which give form to the project of a collective national awareness. The characterization of the existence of an intellectual field with big links, however with its own characteristics and a certain autonomy, which also gets integrated to the cultural debate of the so-called modernist years through the literary vehicles, gives to these intellectual people a co-participation in the renewing movement in the formation context of the brazilian cultural modernity of the early twentieth century

Propagação de danos: importância da atualização dinâmica, efeitos da diluição e propriedades termodinâmicas

Neste trabalho investigamos aspectos da propagação de danos em sistemas cooperativos, descritos por modelos de variáveis discretas (spins), mutuamente interagentes, distribuídas nos sítios de uma rede regular. Os seguintes casos foram examinados: (i) A influência do tipo de atualização (paralela ou sequencial) das configurações microscópicas, durante o processo de simulação computacional de Monte Carlo, no modelo de Ising em uma rede triangular. Observamos que a atualização sequencial produz uma transição de fase dinâmica (Caótica- Congelada) a uma temperatura TD ≈TC (Temperatura de Curie), para acoplamentos ferromagnéticos (TC=3.6409J/Kb) e antiferromagnéticos (TC=0). A atualização paralela, que neste caso é incapaz de diferenciar os dois tipos de acoplamentos, leva a uma transição em TD ≠TC; (ii) Um estudo do modelo de Ising na rede quadrada, com diluição temperada de sítios, mostrou que a técnica de propagação de danos é um eficiente método para o cálculo da fronteira crítica e da dimensão fractal do aglomerado percolante, já que os resultados obtidos (apesar de um esforço computacional relativamente modesto), são comparáveis àqueles resultantes da aplicação de outros métodos analíticos e/ou computacionais de alto empenho; (iii) Finalmente, apresentamos resultados analíticos que mostram como certas combinações especiais de danos podem ser utilizadas para o cálculo de grandezas termodinâmicas (parâmetros de ordem, funções de correlação e susceptibilidades) do modelo Nα x Nβ, o qual contém como casos particulares alguns dos modelos mais estudados em Mecânica Estatística (Ising, Potts, Ashkin Teller e Cúbico)

Pecolação em uma rede multifractal

In this work we present the principal fractals, their caracteristics, properties abd their classification, comparing them to Euclidean Geometry Elements. We show the importance of the Fractal Geometry in the analysis of several elements of our society. We emphasize the importance of an appropriate definition of dimension to these objects, because the definition we presently know doesn t see a satisfactory one. As an instrument to obtain these dimentions we present the Method to count boxes, of Hausdorff- Besicovich and the Scale Method. We also study the Percolation Process in the square lattice, comparing it to percolation in the multifractal subject Qmf, where we observe som differences between these two process. We analize the histogram grafic of the percolating lattices versus the site occupation probability p, and other numerical simulations. And finaly, we show that we can estimate the fractal dimension of the percolation cluster and that the percolatin in a multifractal suport is in the same universality class as standard percolation. We observe that the area of the blocks of Qmf is variable, pc is a function of p which is related to the anisotropy of Qmf

Projetos políticos pedagógicos dos cursos de Odontologia do RN : formação profissional e a perspectiva da atenção à terceira idade

Brazil has been undergoing major demographic change.According to IBGE, the next 20 years the country's elderly population may reach over 30 million people. This tariff provides specifics regarding the process of health / disease. It is essential that higher education institutions are committed to this demand in view of the integrated training of health needs of society. The aim of this study is to analyze the Pedagogical Political Projects (PPP) of courses in dentistry in Rio Grande do Norte (RN), according to the national curriculum guidelines (DCNS) and training from the perspective of health care for the elderly. This is an exploratory study with a qualitative approach: with records and interviews. The study subjects were an Assistant Professor in the development of PPPs for each institution. The scenario in this study were dental training institutions in the newborns. Initially, the analysis of the PPP was by using the Alceste 4.9 software. The interpretation of the contents of interviews with teachers was done through content analysis of Bardin (2010). The PPPs are based on the DCNS, meet the characteristics of regional and seek a generalist, but still strongly directed to technical and scientific aspects of professional practice. Efforts and institutional approaches, involving teachers and students of the courses are being mobilized for training with more articulated network of health services. However, the emphasis on content pertaining to the health care of the elderly, is still limited when compared to those targeted content inherent in children and adolescents in all three curricular structures. It is reasonable to conclude that the historical, political, scientific, cultural and social, present in society, influence the formation of the dental professional RN. The greater participation of society in the process of vocational training in dentistry is needed. This can be done from the involvement of universities with health councils, bodies representing the dental profession and other segments of civil society in order to induce changes that generate ideas and educational practices integrative and interdisciplinary, with emphasis on continuing education for teachers, servants, employees and students. Containing conduct this process inherent flexibility of curriculum, teaching-service integration and coordination abilities and professional skills that are essential to understanding the human being and its complexities

Caracterização e modelagem dos sistemas de produção de caprinos leiteiros

The objectives of this research were characterizing the dairy goat production systems and model it using linear program. On the first step of this research, the model was developed using data from farms that was affiliated in the ACCOMIG/Caprileite, used a similar dairy goat production systems and have a partnership program with Universidade Federal de Minas Gerais . The data of research were from a structured questionnaire applied with farmers and monitoring of production systems during a guided visit on their farms. The results permitted identify that all farms were classified as a small and have a intensive production system. The average herd size had 63.75 dairy goats on lactation; it permits a production of 153, 38 kg of goat milk per day. It was observed that existing more than one channel of commercialization for the goat milk and their derivative products. The data obtained, on the first step of this research, was used to develop a linear program model. It was evaluated in two goat production systems, called P1 and P2. The results showed that the P1 system, with an annual birth and lactation during approximately 300 days was the best alternative for business. These results were compared with a mixed (beef and dairy) goat system in the semiarid region, which indicated merged with both systems. Therefore, to achieve profits and sustainability of the system, in all simulations it was necessary a minimum limit of funding of U.S. $ 10,000.00; this value permit earning of U.S. $ 792.00 per month and pay the investment within 5 years

A dimensão sociocultural da reforma psiquiátrica: articulando redes para a consolidação da estratégia de atenção psicossocial

This thesis aims to discuss on articulations that have been produced on the socio-cultural field in the Psychiatric Reform process and its pertinence to the streghtening of Psychosocial Care Strategy (EAPS) in Fortaleza/CE. Such interest has been justified by the need to promote not only the production of these networks, but also interfaces to enable strategies of support and sociability from the perspective of deinstitutionalization of madness. We were inspired by the cartography perspective of Deleuze e Guattari, and determined as objectives: 1) to discuss the complexity of Psychiatric Reform process and analyze the EAPS as a model for the current Mental Health policy in the country; 2) to map socio-cultural strategies connected to the CAPS network in the city, investigating experiences that already exist or may be constituted as everyday social support networks; 3) from that mapping to start, define and discuss some aspects that converge to the accomplishment for this new mental health paradigm, drawing a cartography of the issues and movements in progress. The mapping was carried out in 2009 and consisted of semi-structured interviews with the coordinators of the 14 existent CAPS and with some people connected to the Coordination of Mental Health. Besides, during the whole development of the study, we have taken part in public events that brought us clues on the connection between mental health and culture. From the survey produced, we defined three vectors for discussion (Art, Labour and Partnership with Social Movements) which have been highlighted as effective possibilities of intervention in the socio-cultural field of Psychiatric Reform in Fortaleza and reveal important paths on the fulfillment process of a new pattern of care. For each of these axes, we chose a field of empirical research (Projeto Arte e Saúde, COOPCAPS e MSMCBJ) in which we could better understand their strengths and difficulties, starting from open interviews with some of their actors and the production of a diary of sensations in 2010. We have seen that they are articulated with the proposal of EAPS, being part of the concerns to the National Mental Health Policy and also the municipal administration. However, we have noticed to be necessary to promote those dimensions further, focusing on its complexity at the macro and micro policies, with the purpose of leading the Psychiatric Reform process