9 resultados para LET

em Universidade Federal do Rio Grande do Norte(UFRN)


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Actually in the oil industry biotechnological approaches represent a challenge. In that, attention to metal structures affected by electrochemical corrosive processes, as well as by the interference of microorganisms (biocorrosion) which affect the kinetics of the environment / metal interface. Regarding to economical and environmental impacts reduction let to the use of natural products as an alternative to toxic synthetic inhibitors. This study aims the employment of green chemistry by evaluating the stem bark extracts (EHC, hydroalcoholic extract) and leaves (ECF, chloroform extract) of plant species Croton cajucara Benth as a corrosion inhibitor. In addition the effectiveness of corrosion inhibition of bioactive trans-clerodane dehydrocrotonin (DCTN) isolated from the stem bark of this Croton was also evaluated. For this purpose, carbon steel AISI 1020 was immersed in saline media (3,5 % NaCl) in the presence and absence of a microorganism recovered from a pipeline oil sample. Corrosion inhibition efficiency and its mechanisms were investigated by linear sweep voltammetry and electrochemical impedance. Culture-dependent and molecular biology techniques were used to characterize and identify bacterial species present in oil samples. The tested natural products EHC, ECF and DCTN (DMSO as solvent) in abiotic environment presented respectively, corrosion inhibition efficiencies of 57.6% (500 ppm), 86.1% (500 ppm) and 54.5% (62.5 ppm). Adsorption phenomena showed that EHC best fit Frumkin isotherm and ECF to Temkin isotherm. EHC extract (250 ppm) dissolved in a polar microemulsion system (MES-EHC) showed significant maximum inhibition efficiency (93.8%) fitting Langmuir isotherm. In the presence of the isolated Pseudomonas sp, EHC and ECF were able to form eco-compatible organic films with anti-corrosive properties

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This doctoral thesis presents an analysis of the production of bicarbonates and related regional development in Brazil. It is widely believed that one of Brazil s vocations lies in the agro-energy sector. However, current national agro-energy policies, together with the experience of Petrobras (the national oil company) in rural settlements in the state of Rio Grande do Norte, show that Brazil has fallen short of effectively including the North and Northeast regions of the country, let alone small-scale rural producers (residing in rural settlements or not), in the development process and related benefits from the country s participation in the current world energy grid. The methodology entails secondary research related to the theme, such as books, official documents, websites and statistical databases from diverse sources, in addition to an analysis of statements from interviews of Petrobras representatives and other important scientific, institutional and labor union authorities, in relation to agro-energy issues and the socio-economic participation of family-based agriculture in this process. Principal findings show a correlation between agro-energy and regional development, creating the potential for numerous opportunities and challenges. Findings demonstrate the possibility of reversing/reducing historically rooted indices of hunger and poverty that continue to devastate the North and Northeast regions. At the same time, the thesis points to a potentially catastrophic increase in regional disparities, should the present historic moment not be seized upon so as to include these regions. Classic examples of non-policy at the federal level are presented as evidence of the absence of a regionally focused agroenergy policy in the current government, reinforced by the experiences of Petrobras in the Rio Grande do Norte rural settlements. Finally, the thesis concludes that there is an urgent need to create a government-sponsored enterprise (with a structure similar to Petrobras) with the purpose of implementing a truly broad and inclusive development process for the bicarbonates production sector, while remaining attentive to Brazil s opportune and critical role in the world s current agro-energy scenario.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The literature about the Geography teaching has shown that most male and female teachers of this subject go on guiding their teaching practice based on the traditional Geography fundamentals, whose main characteristic consist in the description of places. The incorporation of scientific standards that change the old principles and concepts have not been happening, unless in a punctual way. The overcoming of the traditional Geography, related to the aspects accepted by the scientific field have not happened in Brazil yet, not only because of certain obvious obstacles, as the literature has been pointed out but also by symbolic obstacles, which block the incorporation of the new, of the non habitual action. One of those obstacles that motivated the accomplishment of this study was the social representations that are theoretically studied here under the perspective developed by Serge Moscovici. Then, the focus of this doctorate study is concentrated in the apprehension of the content and structure of the social representation of teaching of Geography and its relation with the habitus that gives form and social visibility to the ones who are teachers of that subject in Teresina. The consecution of this work was especially based on the Pierre Bourdieu´s praxiology, mainly on the concepts of social field, habitus and capital, as well as the theory of social representations, specifically on the approach of central nucleus developed by Jean-Claude Abric and Jean-Claude Flament. The initial hypothesis pointed out the existence of a Geographer´s primary habitus built through the development process of the geographic science field in Brazil, as a basis of production of a social representation of teaching geography . That representation, however, would act as a symbolic obstacle to the incorporation of the new scientific contents and pedagogical practice, which require from the teacher investigative and questionable attitude in the presence of the reality and contents approached in the classroom. That initial hypothesis laid on the theoretical purpose that it has been developed by Domingos Sobrinho (1997), which states that there is a narrow relationship between the habitus and social representation. The study was developed with male and female teachers of Geography from public schools of Teresina. The methodology involved the use of a questionnaire, the free-word association technique and deep interviews. The achieved results showed the presence of a complex process of representational construction and its articulation with a habitus produced by the synthesis of several situational and cultural referents, from among of them we can point out an insertion in a social field of practice exclusively related to the teaching and the reproduction of a professoral teaching (SILVA, 2003), built through the school development process, which those male and female teachers were exposed. The initial hypothesis that considered the local reproduction of a primary habitus of the Geography was denied, therefore, it was verified that there is not in Teresina the production/reproduction of the structures, rules and practice of the national scientific field, in which this subject is inserted. Hence, the incorporation of the new patterns of the geographic scientific knowledge is difficult because of the inexistence of a scientific habitus, that is, mental schema systems that would let the teachers mentioned above connect themselves appropriately to the science and its practices. So, it has gotten a social representation of teaching geography based on contents strictly related to the reproduction of structures, mental schema from the educational field which attach themselves to the hegemonic pedagogical practices in the national scope

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper deals with sport as a possibility of disclosing the sensible, and defends the idea that being a sportsperson equals living an aesthetic and educative experience in which one can interacts with the sensible by the athletic body s reverberation of sensations in the dimension of the experienced. We try to answer, in our work, basically three questions: what moves the athlete when practicing a sport? Which are the meanings and motivations for the practice of sports? At what measure the athlete s experience gains an educational character? Sport is debated in this work as an extension of the living, as long as it tries to understand the meanings inherent to sport itself as well as to the sportive experience as a kind of education. In support of our argument, we give a theoretic and philosophical approach to our thesis, based on thinkers like Maurice Merleau-Ponty, Walter Benjamin, Marcel Mauss and Friedrich Schiller. For this purpose, we get support on the phenomenology of the French philosopher Maurice Merleau-Ponty. Our reference is the living world of the athlete and his experience as a field of the sensible. Our point of departure is the analysis of the narratives of sport experiences, including five aesthetic elements; time and space of the body in the sports courts; the look on the sportive context; the contact with the adversary; victory and defeat; the technical gesture. Besides it, we worked out an aesthetic evaluation of the movies Olympia and Invictus , what let us discuss three thematic categories: sensibility, emotions and the play paradox. Subsequently, we point sport as an optimizer of the sensible education, present on the body s processes, like the body in movement. It was also made clear along this paper that we tried to accomplish an analysis on sports centered in the athlete s body as an outfit of the senses to things related to the sensible, whose aesthetic experience overpasses any deterministic conception that should sum up the sportive world to mercantilization, discipline practices and mechanicism. This approach franchises gateways to a Physical Education which, containing sports as one of its support, let pupils enjoy the pleasure of constructing common objectives, incorporating the capacity of replicating, re-making and playing as a field of possibilities offered by an education characterized as being moving, sensible and fitful to a body in movement

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The subject of Classic Gravitation is part of the actual curriculum for High School in Brazil, and it is taught in the first year of that education level. This master thesis presents a research regarding the subject Classic Gravitation in High School. This research was based in two complementary guidelines of research and action. The first guideline was the analysis of 21 didactic books of physics which are the more frequently used in High School, in the city of Natal/RN. The second guideline, worked after being verified the most common deficiencies presents in the didactic books, was the elaboration, followed by a practical application, of a course suggesting how to approach that subject in the classroom. The Parâmetros Curriculares Nacionais para o Ensino Médio (National Curricular Parameters for High School PCNEM) defend that Classic Gravitation is very important in the student s formation and that its study helps the comprehension of many nature s phenomena. Because of this vision of that subject by the PCNEM, the 21 analyzed books were separated in two groups: the first one, containing 10 books, was edited before the spreading of PCNEM, and the second, with 11 books, after that spreading. Whatever the group to which the didactic books belonged, the great majority of them let that subject in a second plan; two of them even suggesting, in the teacher s orientations, that the subject Gravitation can be suppressed in case of insufficient time . These analyses points that the PCNEM had produced no changes in the conception of the authors that wrote books regarding that subject. To analyze the didactic books, we elaborated a script which was used as an analysis tool, in which we put in evidence the relative importance of the historic and philosophic contextualization of the subject, the quotidian experience of the students and the interdisciplinary approach, among other aspects. It became evident that the didactic books give very little emphasis to historic aspects of the knowledge construction, to the relations with the day-by-day questions and to the interdisciplinary character of the subject Gravitation. It calls attention the non concordance among the authors opinions regarding the necessary previous knowledge or prerequisites the students should fulfill in order to begin to study Gravitation. The course we elaborated was given to a group of teachers as well as to students. In those courses we treated theoretical and practical aspects and emphasized historical questions and the ones which are related to people s daily life. The course for teachers was realized as an extra-mural activity of the UFRN and was given by the author of this thesis at the Escola Estadual Francisco Ivo Cavalcanti (a state public school in Natal/RN). There were 23 teachers present, from several public schools and several fields of knowledge. The thesis supervisor and the master degree s colleagues of the author acted as collaborators , reporting the participants opinions and speeches. The course to the students, on the other hand, had the participation of 300 regular students who belonged to 6 different 1st year classes of the High School Escola Marista de Natal (RN), in which the author acts as a physics teacher. The student s course was realized as part of the regular curriculum activities, in which three classes stood under the responsibility of the author and other three classes in charge of another Marista s teacher, who participated as a collaborator . The teacher s course as well as the students one were given in two stages, with five hours each. The first stage was divided in two moments, the first one focused on the survey of the spontaneous conceptions about gravitation, in which we worked basically with experiments of free throwing and pendulum, and the second one focused in theoretical presentations and quarrels about universe s models. In the second stage of the course we improved the study of Kepler s laws and the Newton s Universal Gravitation law, and we used as motivating tools some practices involving the construction of the solar system in scale. As instruments for evaluating both courses we used questionnaires and reported the speeches with participants opinions, beyond usual written evaluations in the course for the students. The teachers who participated in the course showed very good wills in realizing interdisciplinary practices; nevertheless, according their own speeches, they frequently came across the difficulty of how to do . From the experience we had in both courses, we conclude that the approach we propose hear to the teaching of the subject Classic Gravitation , supported on the tripod theory, practice and historical and philosophical aspects, is viable and effective. One hopes that this research may contribute in the formation of a opinion, among the teachers, concerning how to approach the subject of Classic Gravitation, and may offer suggestions in order those who want to apply that approach may develop classroom practices aiming to improve the teaching of that subject, which has a singular importance in the formation of High School students

Relevância:

10.00% 10.00%

Publicador:

Resumo:

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

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The fissures aquifer northeast semi-arid Brazilian, present high text frequently of leave, with of low a hídric availability. The research has as objective main to analyze the components that inside influence in the salinity of the waterbearing fissures of an evaluation physicist-chemistry of the water, leading in consideration the physical interventions of the environment. One used techniques of interpretation of image of Landsat satellite -1999 and delimitation of the micro basin through the topographical map SUDENE. One identified waters of the NaCl type with Ca++ and Mg++ in secondary concentrations. The analyzed wells (15), had presented an average salinity of 5.147 mg/L of STD and a well only supplies drinking waters with 319 mg/L of STD. The recharge of the aquifer one if carries through for infiltration in the open fracture of ortognaisse it migmatization. The type and directions of the fracture do not control the STD. Relations between salinity and out let do not exist. The quality of the well of low salinity is identical the superficial waters (aquifer dam and alluvial). The studies of the meteoric erosion processes had evidenced that in the transformations of the rock in ground, the Ca++ and Na+ are taken for superficial waters. The treatment of the data chemical showed that the grade of Na+, Ca++, Mg++ and Cl-are controlled for the evaporation process, from only water that would have the qualities of superficial waters or the well of low salinity. Already the HCO3-grade is controlled for the precipitation of the dolomite. The STD of this aquifer one would be consequence of the high tax of evaporation of dams constructed in regions of plain topography. You leave them precipitated in deep argillaceous ones dry dams are led for the aquifer in first rains. The research suggests some recommendations for the use and exploitation of the water salinity in piscicultura, carcinicultura, culture of the grass-salt (Atriplex sp), among others

Relevância:

10.00% 10.00%

Publicador:

Resumo:

ON reflecting the traditional teaching approach, characterized by non-dynamic and descriptive methods that still persists in schools at the present time, associated to social living enrichment has motivated the search for new techniques to stimulate students in the process of teaching, such as roleplaying games, known as RPG, already being used in various school disciplines. Considering the amount of themes in general sciences and in biology, in particular that could be explored through RPG our purpose was to develop a game to be used as a learning complementary tool. PANGÉIA, the game we developed, was based on the GURPS system and to be placed at the geological Eras of the earth. The objective of the game was playing a character that represented an animal belonging to a Class of Vertebrates, and making it surviving and reproducing during risky situations presented in the game. These situations were narratives by the Master about challenges that the character would face, which should be solved using the dices. Along the narrative, the Master introduced concepts and informations about the subject being studied. To evaluating how the game worked out, we solicited 11 volunteers, from two different schools in Natal, to play PANGÉIA. Before starting the game, and without knowing the final objectives of our project, the volunteers answered a general questionnaire to let us know their level of knowledge, which was also answered after playing the game. The comparison of the volunteers answers before and after playing the game suggests that this activity influenced them. Also, based on this test, we identified critical aspects to be modified in PANGÉIA, specially a stronger relation between both the questionnaire and the game placement with the narrative of the master. In order to have PANGÉIA used as a complementary learning tool, a teachers handbook has to be written, including rules concerning the format of game application. Nonetheless, based on this pilot study, we conclude that topics on sciences and biology can be easily adjusted to RPG format, and its flexibility provides multiple combinations that can be used to help learning the more difficult topics to be taught in a class

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The World Wide Web has been consolidated over the last years as a standard platform to provide software systems in the Internet. Nowadays, a great variety of user applications are available on the Web, varying from corporate applications to the banking domain, or from electronic commerce to the governmental domain. Given the quantity of information available and the quantity of users dealing with their services, many Web systems have sought to present recommendations of use as part of their functionalities, in order to let the users to have a better usage of the services available, based on their profile, history navigation and system use. In this context, this dissertation proposes the development of an agent-based framework that offers recommendations for users of Web systems. It involves the conception, design and implementation of an object-oriented framework. The framework agents can be plugged or unplugged in a non-invasive way in existing Web applications using aspect-oriented techniques. The framework is evaluated through its instantiation to three different Web systems