828 resultados para Ceará-Mirim


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The mesoporous molecular sieves of MCM-41 and AlMCM-41 type are considered as promising support for metal in the refining processes of petroleum-based materials as catalysts and adsorbents for environmental protection. In this work the molecular sieves MCM-41 and AlMCM-41 were synthesized by replacing the source of silica conventionally used, for quartz, an alternative and abundant, and the use of waste from the production of diatomaceous earth, an aluminum-silicate, as a source aluminum, due to abundant reserves of diatomaceous earth in the state of Rio Grande do Norte in the city of Ceará-Mirim, with the objective of producing high-value materials that have similar characteristics to traditional commercial catalysts in the market. These materials were synthesized by the method of hydrothermal synthesis at 100 º C for 7 days and subjected to calcination at 500 º C for 2 hours under flow of nitrogen and air. The molecular sieves were characterized by X-ray diffraction (XRD), differential thermal analysis (DTA) and thermogravimetric analysis (TG), adsorption of N2 (BET and BJH methods), spectroscopy in the infra red (FTIR), microscopy scanning electron (SEM) and transmission electron microscopy (TEM). The analysis indicated that the synthesized materials showed characteristic hexagonal structure of mesopores materials with high specific surface area and sort and narrow distribution of size of pores

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This article is about a study about the training needs for teachers of elementary school in the field of Geography. It is our objective to grasp their conceptions of training needs and reflect about their formative needs to teach geography. We consider the training as reflective process that involves the movement of changes and improvement beyond of formal learning, considering its numerous dimensions. We reflected about formative needs in light of the readings of Rodrigues Esteves (1993), Silva (2000), Roberts (2006), Vieira (2010). The discussions about conceptions were based on Ferreira (2007). The empirical reference constitutes to a private school in the city of Ceará-Mirim/RN, SECAT Centro de Ensino. The social subjects of our research are five teachers who work in the initial years of elementary school. We resorted a survey (auto) biographical, based on the studies of Passeggi (2011), Delory (2008), Bertaux (2010) e Josso (2010), since it is our intention to turn to the historicity of the subject and the learning, recognizing the links between him and the world and the experiences based on for learning and adult training. As technical and methodological procedure we will use the Training Narratives, whose application allows the understanding of memories and stories of schooling teachers, since are reported events occurred during the development of the individual through seminars Biographical. We observed on the narratives constructed by the teachers the absence assignments of meanings to a reworking of the theoretical formative needs and questions of its organizing principles. However, we notice the teachers were able to develop senses and means to conceive the phenomenon in study, in a descriptive way, through articulated enunciations, including aspects and opportunities linked to their teaching practices and future formative prospects. Regarding School Geography, we based our studies in the reflections of Smith Junior (1994, 2000), Tonini (2003), Vesentini (2004) and Vlach (1991), among others. We verified that the needs evidenced by the teachers to teach geography were constructed from the contexts of their teaching practices present in their school and professional trajectories. Therefore, we noticed the need for formal pedagogical qualification so that we can conceive the phenomenon in study beyond its descriptive character, understanding that it is necessary to point out reflections and questions about the dynamics of production of global capital, which conveys its interests in the contexts that often emerge formative needs of the educational system

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La investigación fue realizada con profesores de los años iniciales de la enseñanza básica, alumnos de la carrera de Pedagogía Licenciatura Plena del PROBÁSICA de Ceará-Mirim (RN). Tuvo como objetivo general el estudio de lo proceso de apropiación de esa habilidad, segundo las siguientes perspectivas teóricas: históricocultural, de L.S. Vygotsky, teoría de la actividad, de A.N. Leontiev, y la teoría de la asimilación por etapas mentales, de P. Ya Galperin. La metodología se desarrolló organizándose en tres etapas: el diagnóstico inicial, con el análisis del nivel de desarrollo de la habilidad de los profesores; el proceso formativo, con la orientación del aprendizaje, el control y la evaluación del desarrollo; y el diagnóstico final, con el análisis del nivel alcanzado en la experiencia. Los instrumentos utilizados fueron: un cuestionario, para la caracterización de los sujetos de la investigación, el planeamiento de enseñanza de los profesores y el diario de clase, donde se registraba lo que ocurrió en cada orientación y realización del proceso formativo. Los resultados referentes a los niveles iniciales del desarrollo de la habilidad han revelado un grado de espontaneidad en el planeamiento de enseñanza de los conceptos. Durante el proceso de enseñanza y aprendizaje, los profesores han expresado sus dificultades, pero también las posibilidades de mudanza para que alcanzaran un nuevo nivel de desarrollo. Para el análisis del nivel inicial y del desarrollo de las habilidades de los profesores para planificar situaciones de enseñanza con la definición y con la identificación, fueron utilizados los siguientes elementos: el dominio del concepto, el dominio de esos procedimientos lógicos y las categorías del planeamiento (objetivos, contenidos, estrategias de enseñanza, control y evaluación). En cada etapa surgieron obstáculos, pero también aspectos que han revelado la posibilidad para aprender una nueva forma de planear, con apropiación de nuevos fundamentos teóricos. La práctica docente se constituyó en un elemento que facilitó la comprensión y la apropiación de las habilidades de planear situaciones de enseñanza de conceptos mediante la definición y la identificación

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This work analyses pedagogical practices of Adelle Sobral de Oliveira, from 1900 to 1940, in order to notice how her performance as educator and administrator took place in Externato Angelo Varela in the Rio Grande do Norte city of Ceará-Mirim within a time in which the public teaching started to be considered modern in the State. Adelle was a self learner who developed an important role as a mentality mentor of a generation in the region. As the research corpus we have taken the five Reading Books written by Felisberto de Carvalho used by Adelle in her Externato, interviews with her ex-students and researches in the newspapers of her time, in the Public Archives and in the Historical and Geographic Institute of Rio Grande do Norte, and also in the governors messages, Education Department documents such as laws, and government decrees and acts. It was also taken as a research font the Publich Archives of Ceará-Mirim. The aim of this PhD thesis is understand the primary instruction spreading and modernization in the countryside of Rio Grande do Norte, which began with her teaching pedagogical practices. The research results show Adele Oliveira used practical and experimental modern methodological teaching methods in the subjects she taught. Due to this, in her scholar routine, she avoided physical punishment and mechanical teaching and learning strategies

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The work objectified to apprehend the degree of the teachers' concept concerning the territory concept and to intervene with situations of critical reflections to accompany and to analyze the process of conceptual elaboration. It contemplates on the (new)meaning of knowledge and (new)elaboration of the concept in study done inside a pedagogic intervention. The Municipal School Dr. Julio Senna - Ceará-Mirim/RN and six (6) teacher-collaborators that taught in the 3rd and 4th grades of the fundamental teaching, constitutes the empiric field of the research. Its theoretical-methodological contributions are built in the studies of Vigotski (2000a, 2000b and 2001) on the formation process and development of concepts; in the methodology colaborate (Ibiapina (2004), Bartomé (1986), Kemmis and Mctaggart (1988), Arnal, Del Ricon and Latorre (1992), Pepper and Ghedin (2002), among others) and in the critical-reflexive conception of the Geography (Soares Júnior (2000 and 1994), Silva (1998), Raffestin (1993), Santos (1994), Felipe (1998), among others). The accomplishment of the work presupposed starting from the reflections on the following subjects: which the teachers' understanding in the school space concerning the territory concept? How does happen the process of conceptual construction territory for the teachers? The analysis of the teachers' previous knowledge on the concept in study, evidenced that its apprehensions on the attributes of the referred concept went mentioned the to light of the perceptible dimension of the real-concrete relationships of the reality linked to the degree of the spontaneous concepts and followed by the ideas of the traditional, humanistic and cultural geographical conceptions (positivism and phenomenology), restricting the territory meaning the notion of State-Nation and place of the men's dwelling. In the intervention process, it was verified to real possibility of the acquisition of indispensable scientific concepts to the process of (new)meaning conceptual of geographical knowledge through the continuous practice of the educational formation, when it was evidenced that the teacher-collaborators acquired high degrees of attributions of the significance of the territory concept to the they elaborate generalizations by means of analyses and syntheses of the concept-attribute (essential and multiples) of the reference conceptual in study

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The theory contemporary in the field of early children education, as well the legal discourse and official texts valid in our country point to the need for systematization of proposals pedagogic / curriculum in institutions, built and carried out by subjects that act as factor of assurance care quality. Quest us about what knowledge are required to teachers in developing a proposed curriculum for children education. Defined as an object of study, the knowledge teachers necessary for the development of a proposed curriculum for children education. As goals, assume: investigate teachers knowledge necessary for the development of a proposed curriculum in a Public Institution for children education and contribute to the (new) meaning on the part of teachers, knowledge needed to build a proposed curriculum for children education. Assuming the principles of the paradigm of qualitative research, we have developed a research institution of a children education Network Public Hall of Ceará-Mirim-RN, which serves children of four and five years old (preschool) with the participation of 17 teachers and two supervisory (teachers) that institution - subject of our research. Therefore, we have adopted the principles of action research, according to which the knowledge gained through research should build so shared / dialogue in the relationship between researcher and participants, what is the implementation of an effective action formative. As the search procedures developed observations no-teaching participants in the meetings and activities of the classroom; semi-structured interviews (individual and collective) with teachers and supervisors; analysis of school documents and participant observation in the seminars of studies reflective. The latter is implemented as key moments of speech and thought, and finally to (new) meaning of knowledge, the subject of the research-action. For these knowledge, the systematization of the register built was developed based on the principles of analysis of Content that guided us to the definition of two categories 1) knowledge teachers concerning conceptions of curriculum / proposed curriculum and 2) knowledge teachers concerning specifics of children education. From these were built subs representing thematings more specific and significant, among the many that emerged in the analysis: 1.1) Definitions of curriculum and curriculum proposal; 1.2) The subjects makers / implementing a curriculum / proposed curriculum; 1.3) elements constituting a curriculum / proposed curriculum for children education and 2.1) Functions of children education and conception of child; 2.2) The space of the play in the organization of routine. Under the intervention could significant advances with regard to (new) meaning of such knowledge from the subjects, with major disruptions to their original designs. These are presented and reflected in this work. In front of this movement, transformation, made the need for a permanent work in the context of the institution of in-service training, or mediated by pedagogical coordinator or other to assume this role with teachers, in order to provide the development and effectiveness of proposed curriculum consistent and contextualized in practice effective with the children concrete envisage the service to their specificities and a quality education

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The accomplished researches in the education field focus on the importance of the accomplishment of actions involved in the analysis of the needs to graduate teachers as a way to adequate to socialcultural changing that require more and more a creative activity to prepare teachers in their graduation perspective. The worry with a fail at school linked to public school students lead us to make this thesis which goals are: investigate the needs of the graduation of teachers at public Elementary Schools concerning to the subjacent knowledge to the development of a pedagogic practice of alphabetizing with literacy and (re)create, with some teachers as active participants in the researches, knowledge regarding the process of alphabetization with literacy , based on the graduation of teachers. The study was accomplished in a municipal Elementary School in the Ceará-Mirim city, located in the state of Rio Grande do Norte, which offers both I and II levels of the Elementary School, 7 teachers and the principal of the school were subjects of our researches. The starting point was the needs of the graduation as subject phenomena, socially created and that allow people to be aware of the goals of a graduation. The investigative broach is qualitative, whose fundamental purpose is the understanding of the meanings, symbols, values and intentions of the mankind actions, as regards to other humanbeing and the contexts in which they interact. Within this context, we chose the investigation-action for we consider this kind of research a place for investigation and professional graduation, in which teachers and the researcher herself assume responsibility of problematizing, build the needs of graduation and think about their practices. As proceedings to create and analyze data, we developed participant observations during the activities in classroom; semi-structured interviews (individual and in groups) with teachers and the principal; analysis of documents and meetings at school for reflexive studies that enabled us to gather data in a pyramidal panoramic view and analyze the contents. The research revealed that the analysis of necessities to graduate teachers is a resource able to contribute to the planning of projects of keeping on graduating more properly, and thus create a critical and reflexive identity for teachers. This way, it was possible the graduation necessities could be revealed and also the knowledge of teachers as regards to alphabetization inserted in a perspective of literacy. Nowadays, conceptualized needs upon difficulties of teachers, there is a tendency to translate them into theorization of problems, without application to these knowledge of teachers, as well as their wishes for changing, especially when those needs are built to analyze and consider concrete practices. Therefore, the graduation experiences have enabled the abandon of a mechanical broach for teaching reading and writing. It has also lead teachers to assume a posture of providing their students the understanding about the reading and writing processes and their functions as social instruments. The graduation theme contents allowed the knowledge to conceive reading and writing in new perspectives, according to their social functions, so that they can improve the education with literacy quality. This theoretical construction has enabled us to understand and consider the necessities of the graduation as progressive process, and has given us the possibility of re-think our own learning processes at the university and review the pedagogical practices of public school teachers. Our conclusion is that once teachers consider their own graduation needs, it contributes to change their concepts and practices in education and literacy, even though there used to be many difficulties in their graduation and organization of the pedagogical work

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This article is about a study about the training needs for teachers of elementary school in the field of Geography. It is our objective to grasp their conceptions of training needs and reflect about their formative needs to teach geography. We consider the training as reflective process that involves the movement of changes and improvement beyond of formal learning, considering its numerous dimensions. We reflected about formative needs in light of the readings of Rodrigues Esteves (1993), Silva (2000), Roberts (2006), Vieira (2010). The discussions about conceptions were based on Ferreira (2007). The empirical reference constitutes to a private school in the city of Ceará-Mirim/RN, SECAT Centro de Ensino. The social subjects of our research are five teachers who work in the initial years of elementary school. We resorted a survey (auto) biographical, based on the studies of Passeggi (2011), Delory (2008), Bertaux (2010) e Josso (2010), since it is our intention to turn to the historicity of the subject and the learning, recognizing the links between him and the world and the experiences based on for learning and adult training. As technical and methodological procedure we will use the Training Narratives, whose application allows the understanding of memories and stories of schooling teachers, since are reported events occurred during the development of the individual through seminars Biographical. We observed on the narratives constructed by the teachers the absence assignments of meanings to a reworking of the theoretical formative needs and questions of its organizing principles. However, we notice the teachers were able to develop senses and means to conceive the phenomenon in study, in a descriptive way, through articulated enunciations, including aspects and opportunities linked to their teaching practices and future formative prospects. Regarding School Geography, we based our studies in the reflections of Smith Junior (1994, 2000), Tonini (2003), Vesentini (2004) and Vlach (1991), among others. We verified that the needs evidenced by the teachers to teach geography were constructed from the contexts of their teaching practices present in their school and professional trajectories. Therefore, we noticed the need for formal pedagogical qualification so that we can conceive the phenomenon in study beyond its descriptive character, understanding that it is necessary to point out reflections and questions about the dynamics of production of global capital, which conveys its interests in the contexts that often emerge formative needs of the educational system.

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Descriptive and quantitative study, with the objective of review the positive and negative aspects experienced by professionals working in the Family Health Strategy (ESF) of Ceará-Mirim town, at Rio Grande do Norte state. The population included 190 healthcare professionals that integrate the family healthcare staff and the data-collection occurred in a meeting at their workplace, with the implementation of a questionnaire. Results were organized in Microsoft Excel spreadsheet software, with descriptive statistical analysis in tables, graphs and tables through frequencies, averages values and standard deviations. There is a predominance of females (n = 137) and higher rates in almost all professions, and higher average age (38.9%, SD = 7.8) and income wage (average = 10) in the medical category. Regarding the more developed activities, for physicians and nurses are the healthcare actions in the Unit, the oral hygiene for dentists, the immunization for auxiliary nurses (Aux-N), educational meeting for the dental office assistants (ACD), and home visitations to community-based health workers (ACS). About the easiness of work, 93.2% said to be presence of professionals with a personal profile in public healthcare; about the difficulties, 86.8% of professionals cited the unavailability of material, followed by salary range reported by nurses (80.9% ), dentists (80.0%), physicians (73.3%), ACS (83.1%), and Aux-N (90.5%). In relation to working conditions, the unavailability of materials was the most mentioned, with the exception of dentists who reported improvement in wages. We still identify among these difficulties: the drugs availability regarded as first grade obstacle by ACS and physicians, the type of contracts in second grade cited by the ACD and dentists and, in third grade, the salary range cited by dentists and auxiliary nurses. It is concluded that the difficulties and easiness faced by ESF professionals are divergent among themselves. For physicians and nurses, whose healthcare actions become directed to specific groups, the individual and the family, their difficulties relate to the unavailability of materials. For dentists, whose actions more quoted were topical application of fluoride and supervised toothbrush, their greatest difficulty is the salary range. As to the Aux-N, ACD and ACS, for all of them the unavailability of materials has hindered the implementation of their activities in ESF

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One of the concerns of this century is with the handling and the final destination of urban solid waste (RSU), where depending on the form as they will be made use, they can cause diverse problems, they are of ambient or social order, being able to generate the loss of the quality of life and illnesses to the population, of direct or indirect form. The objective of the present work was to diagnosis the environmental partner situation of the Final Destination of the urban solid residues in the District of Guajiru, city of São Gonçalo do Amarante/RN, standing out the partner-economic situation of the scavengers. The research was carried through in the period of March of 2008 the October of 2009, with a methodology developed through analyzes them of documents made available for the state ambient agency, the Air base of Christmas and managing agencies of the city. For collection of the date, it was used directly application of the questionnaire with 20 existing scavengers in points of destination of residues, evaluation of the old place of final destination through the use of the spread sheet of the IQR (Index of Quality of the Residues), developed for the CETESB, identification of the matter dump and photographic register. For effect of treatment of the data, a descriptive analysis with regard to the answers of the interviewed scavengers was carried through. The acquired date, Scale had been according to tabulated and analyzed in Excel 2003, where they had been generated graphical to observe the behavior of the data. The results show that of the twenty interviewed scavengers, 35% possess age between 20 and 30 years; 75% possess incomplete basic education; 60% inhabit in houses of waal or huts (cardboard or wood); 55% do not make use of system of water supply and system of sanitary exhaustion; with regard to income monthly for scavengers, 35% had presented income between R$ 200,00 and R$300,00 and 20% possess income above of R$ 500,00 for possessing another source of income; 80% of the interviewed ones, use some type of equipment of individual protection; In the year of 2009, confirming what it was informed by the State agency of Environment, during the field visit, we evidence that the city of Is Gonçalo do Amarante, currently, destines its residues in Sanitary landfill of São Region Metropolitan of Natal in the District of Massaranduba in the city of Ceará-Mirim, after some interventions of the State Public prosecution service. However, in the district of Guajiru some diggings still exist that today are used as final destination of RCD' s (Residues of Construction and Demolition) of the cities of Natal and São Gonçalo do Amarante, as well as private dumps that are used by scavengers that deviate the final destination (Sanitary landfill) of the residues of the great generators (supermarkets, shopping Center and hotels), with presence of urubus, generating a new ambient problem for the city and the aeroportuária security. Ahead of this scene, the study it suggests viable alternatives for the elimination of the private dumps and for the social situation of the escavengers, aiming at to improve its quality of life and 10 to minimize the ambient impacts caused by the inadequate destination of the solid waste in the community of Guajiru, São Gonçalo do Amarante/RN, being able to contribute so that the public managers carry through action in the handling and the control of the final destination of the urban solid waste

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This study presents a comparative analysis of methodologies about weighted factors considered in the selection of areas for deployment of Sanitary Landfills, applying the methodologies of classification criteria with scoring bands Gomes, Coelho, Erba & Veronez (2000); Waquil et al, 2000. That means, we have the Scoring System used by Union of Municipalities of Bahia and the Quality Index Landfill Waste (IQR) which are applyed for this study in Massaranduba Sanitary Landfill located in the municipality of Ceará Mirim /RN, northeastern of Brazil. The study was conducted in order to classify the methodologies and to give support for future studies on environmental management segment, with main goal to propose suited methodologies which allow safety and rigor during the selection, deployment and management of sanitary landfill, in the Brazilian municipalities, in order to help them in the process to extinction of their dumps, in according of Brazilian Nacional Plan of Solid Waste. During this investigation we have studied the characteristics of the site as morphological, hydrogeological, environmental and socio-economic to permit the installation. We consider important to mention the need of deployment from Rio Grande do Norte State Secretary of Environment and Water (SEMARH), Institute of Sustainable Development and Environment of RN (IDEMA), as well, from Federal and Municipal Governments a public policies for the integrated management of urban solid waste that address environmental preservation and improvement of health conditions of the population of the Rio Grande do Norte

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A região semiárida sofre escassez hídrica. A fim de regularizar a disponibilidade hídrica nos períodos de estiagem, são construídas barragens. No entanto, a qualidade da água armazenada tem sofrido os efeitos do descarte irregular de resíduos no meio ambiente e das atividades antrópicas exercidas nas bacias hidrográficas. A degradação hídrica pode ser constatada a partir do monitoramento dos parâmetros de qualidade da água. Estes dados podem ser analisados através de métodos estatísticos tais como a Análise de Componentes Principais e a análise de agrupamento, que seleciona indivíduos com características semelhantes. O objetivo deste trabalho é realizar oagrupamento dos reservatórios do Rio Grande do Norte, com base nos parâmetros de qualidade da água, para a identificação de grupos homogêneos de reservatórios em termos de fontes de poluição. Serão objeto desse estudo as bacias Piranhas-Açu, Apodi-Mossoró, Trairí, Potengi e Ceará-Mirim. Os parâmetros mercúrio, chumbo, cromo, fósforo total, nitrogênio total e zinco contribuíram para a formação da primeira componente principal, que pode indicar poluição por metais pesados; sólidos totais, DBO, OD e cobre, para a segunda componente, que pode ser indicativo de poluição por matéria orgânica e atividades antrópicas; e clorofila a , cádmio e níquel, para a terceira componente, que pode indicar eutrofização e poluição por metais pesados. De posse das componentes principais se procedeu o agrupamento dos reservatórios, formando-se quatro grupos distintos. Os grupos 1 e 2 são constituídos por reservatórios da Bacia Piranhas-Açu, que apresentou maiores valores de metais pesados. O grupo 3, constituído por reservatórios das bacias Ceará-Mirim, Potengi e Trairí, apresentou maiores valores de DBO e sólidostotais e o grupo 4 é formado por reservatórios da Bacia Apodi-Mossoró. Nas Bacias do Trarí e Piranhas-Açu deve ser coibido o lançamento desordenado de efluentes e fontes de poluição difusas, e implantado um sistema de coleta de esgoto para minimizar a poluição por matéria orgânica

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This dissertation seeks to reflect on the accessibility of the governmental program Minha Casa Minha Vida, track 1, which comprehends people who made 0 to 3 minimum wages within the metropolitan region of Natal RN between the years of 2009 and 2012. The research covers the municipalities benefited by the program: Ceará-Mirim, Extremoz, Macaíba, Monte Alegre, Natal, Nísia Floresta, Parnamirim and São Gonçalo do Amarante. We have investigated the extensions of PMCMV on the context of the access to the city, debating some concepts attached to the capitalist mode of production such as residential segregation and peripherization. We have aimed to identify the accessibility conditions in the new housing complexes from three primal categories, namely, the localization of the complexes, the disponibility of public equipments, services, leisure and cultural properties on the neighborhood and the offer of public transport. Our theorical references are based on the ideas of the british geographer David Harvey on his work Social Justice and the City , from 1980. Harvey s studies made us debate on the locational choice for the social-matter habitation, and also let us discuss the price to accessibility on these new programs and its implications on the income of those who are benefited by them, specially because this is about a low-income population. To the achievement of these objectives, we made use of case study, including desk research, photographic documentation, records of field observations and informal conversations with locals, composing a qualitative study. In light of what has been researched and considering the guiding research questions, we reflect on aspects of the program that can greatly influence the processes of residential segregation and housing periphery of the lowincome population from the precarious conditions of accessibility to the referred population

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This dissertation deals with the characterization, distribution and provenience of heavy minerals along the Piranhas-Açu River, from the City of Parelhas (Seridó River) to your mouth at the City of Macau-RN. Many heavy minerals species were recorded in this study: clinoamphibole, epidote (including zoisite), garnet, sillimanite, tourmaline, staurolite, andalusite, zircon, rutile, augite, ilmenite, hematite and magnetite. Major transparent minerals, those forming more than 5% of some assemblages, are hornblende, epidote, tourmaline, staurolite and zircon. Predominant opaque mineral is ilmenite. Six assemblages were identified along the river: (i) Garnet-hornblende-tourmaline with sillimanite, when cutting rocks of the Seridó Formation; (ii) Hornblende-garnet-zircon, when crossing rocks of the Caicó gnaisse-migmatitic Complex; (iii) Hornblende-zircon-epidote-staurolite, when draining rocks of the Jucurutu Formation; (iv) Hornblende-zircon-epidote, when cutting rocks of the Açu Formation; (v) Hornblende-zircon-staurolite, on the lowermost Açu River, when crossing limestones of the Jandaíra Formation and (vi) Zircon-tourmaline-staurolite in the Açu River mouth (Cenozoic rocks) where coastal process dominate. Mineral ratios that reflect differences in grain shape, density, and selective chemical decomposition were used in an attempt to isolate the effects of source and process as controls of mineral variability. Reworking of the sediments was regionally effective in selective sorting; the more equant minerals (e.g. epidote) and heavier minerals (e.g. opaques) had a higher probability of being selected for permanent deposition during reworking. The processes of selective decomposition stand out at the river mouth. A priori knowledge of provenance, associated with the assemblage distribution and effects of process were utilized to the interpretations, that points to the follow provenances: hornblende comes from micashists of the Seridó Formation, orthognaisses and amphibolites of the Caico Complex, paragnaisses and paranphibolites of the Jucurutu Formation and granites intrusions; epidote comes from paragnaisses and calciosilicatics of the Jucurutu Formation, granites intrusions (-Npy3al/ca and -Npy3mz, gravels deposits and Açu Formation; Andalusite and staurolite come from the Seridó Formation; Sillimanite, tourmaline and garnet come from micashists of the Seridó Formation, as well as from quartzites of the Equador Formation; Zircon comes from Precambrian rocks (pink and prismatic zircon) and from sediments of several cycles (round zircon); Opaques come from all rocks cutted for the Piranhas-Açu River; Rutile comes from metamorphic rocks, in general; Augite comes from the Ceará-Mirim, Serra do Cuó and Macau volcanisms. The texture of gravels deposits reveals a sediment transport mechanisms by traction-current processes, together with a diagenetic clay matrix suggests a hot-humid environments for deposition. The presence of unstable heavy minerals assemblages, as well as pebbles of different composition and degrees of rounding and esfericity, indicate more than one source. The occurrence of calcio/alkaline granites suites, in areas closed to the gravel deposits, suggests that these intrusions are the main source of sediments. This could explain for instance, the significant amounts of epidote and presence of unstable heavy minerals (e.g. hornblende). The analyses of heavy minerals also show significante variability between the modern (Piranhas-Açu) and ancestral (Açu Formation) river sediments. In general, these variations reflect relatively higher unstable and lower stable heavy minerals contents of the modern Piranhas-Açu sediments. The absence of significant compositional differences probably reflects uniform weathering conditions

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This dissertation deals with sedimentological and structural framework of the siliciclastic rock of the Serra do Martins Formation (FSM) in the Portalegre, Martins and Santana plateau, located to the south of Potiguar Basin, in the southwest and central Rio Grande do Norte state. This formation, regarded as of Oligo-Miocene age based on intrusive relations of the Miocene Macau volcanics, has a still disputable age due to the lack of appropriate bio and/or chronostratigraphic markers. The FSSM deposits crop out along 650 to 750 m high plateau, as a remanescent sedimentary cover directly overlying topographically uplifted pre-cambrian crystalline rocks. During the last decades, these deposits were interpreted according to a Tertiary paleoclimatic evolutionary model, associated to pedogenetic processes. The sedimentological characterization of the FSM was done through a detailed study of its facies, petrography and diagenetic features. The facies study was based on description of field relations, textures and structures, the piling up of the strata and their lateral variations. The FSM was deposited by an anastomosing to coarse-meandering fluvial system, including deposits of lag, cannel-fill, ouver-bank and flood plain. The petrographic composition of the sediments, coupled to their facies and paleocurrent directions, suggest a rather distal sourcearea, to the south of the present plateau. The diagenetic study identified an incipient grain mechanical compaction, pronounced dissolution of the framework, matrix and/or cement components, intense precipitation of kaolinite, silic and, eventually, iron oxides, besides mechanical infiltration of the clays. Most of these events, regarded in the literature as associated to near-surface conditions (eo or telodiagenesis), indicate the FSM sediments were never deeply buried. Topographic relations along longitudinal and transversal sections reaching the Potiguar Basin to the north identified regional dips that allow to discuss stratigraphic correlations between the FSM and the basin formations. The sedimentological features of the different units and the intrusive relations of the Macau volcanics were also considered in these correlations,which support the Oligo-Miocene age previously accepted for the FSM. Concerning the tectonic framework of the FSM, this work investigated the pre-cambrian to cretaceous heritage and the cenozoic deformation, allowing the recognition of pre-, sin and post-FSM structures. The crystalline basement, belonging to the Seridó Belt, displays NE and WNW foliation trends related to the Brasiliano-age ductile shear zones. In this terrain, brittle-ductile and brittle NE- and NW-trending structures, associated with extensional joints filled with pegmatites and quartz veins, are related to an E-W compression by the end of Brasiliano Cycle. The E-W joints and NE-trending fractures were reactivated by N-S to N-S to NW extension during late Jurassic to Cretaceous times, controlling the emplacement of the Rio Ceará-Mirim basic dyke swarm and the opening of the Potiguar rift basin