10 resultados para genesis of coal
em Universidade Federal do Rio Grande do Norte(UFRN)
Resumo:
The demand for alternative sources of energy drives the technological development so that many fuels and energy conversion processes before judged as inadequate or even non-viable, are now competing fuels and so-called traditional processes. Thus, biomass plays an important role and is considered one of the sources of renewable energy most important of our planet. Biomass accounts for 29.2% of all renewable energy sources. The share of biomass energy from Brazil in the OIE is 13.6%, well above the world average of participation. Various types of pyrolysis processes have been studied in recent years, highlighting the process of fast pyrolysis of biomass to obtain bio-oil. The continuous fast pyrolysis, the most investigated and improved are the fluidized bed and ablative, but is being studied and developed other types in order to obtain Bio-oil a better quality, higher productivity, lower energy consumption, increased stability and process reliability and lower production cost. The stability of the product bio-oil is fundamental to designing consumer devices such as burners, engines and turbines. This study was motivated to produce Bio-oil, through the conversion of plant biomass or the use of its industrial and agricultural waste, presenting an alternative proposal for thermochemical pyrolysis process, taking advantage of particle dynamics in the rotating bed that favors the right gas-solid contact and heat transfer and mass. The pyrolyser designed to operate in a continuous process, a feeder containing two stages, a divisive system of biomass integrated with a tab of coal fines and a system of condensing steam pyrolytic. The prototype has been tested with sawdust, using a complete experimental design on two levels to investigate the sensitivity of factors: the process temperature, gas flow drag and spin speed compared to the mass yield of bio-oil. The best result was obtained in the condition of 570 oC, 25 Hz and 200 cm3/min, temperature being the parameter of greatest significance. The mass balance of the elementary stages presented in the order of 20% and 37% liquid pyrolytic carbon. We determined the properties of liquid and solid products of pyrolysis as density, viscosity, pH, PCI, and the composition characterized by chemical analysis, revealing the composition and properties of a Bio-oil.
Resumo:
In the last three decades, the subject of the teacher's social identity has been discussed under various theoretical focuses, not only in Brazil, but also beyond our borders. In this thesis, the theme is approached starting from the theoretical proposal that has been developed by Domingos Sobrinho (1994), which is strongly based in the epistemological approach between Pierre Bourdieu’s praxiology and the Theory of the Social Representations formulated by Serge Moscovici. It presupposes that this would make it easier to apprehend the process of construction of social identity of the investigated social group. The universe of the research is constituted by teachers of the fundamental teaching of the municipal district of Maracanaú, state of Ceará, that were active in class-room work there during at least three years, and were registered or had concluded the Course of Educational Formation promoted by UECE in that municipal district. Taking into account that the teacher's social identity is a process in permanent construction, resulting of their daily experiences and of the interferences originated from of the social context, the investigative tasks were implemented in two different stages, although they complement each other. Initially, with the objective of putting in evidence the genesis of the formation of that group’s habitus, an analysis of the family and school lives of eleven teachers who participated in the course was made, using as main sources of data: thematic memorials, semi-structured interviews and observations - inside and out of the class-room – during four school semesters. In the second stage a test of free association of words was applied to 426 teachers, seeking to apprehend the structure of the social representations of family and school – a methodological strategy considered necessary to enhance and identify certain outlines of the habitus in study, besides being in agreement with the theoretical model followed. It became evident from the results that the identity of Maracanaú’s teachers is molded and transformed into a multifaceted dynamic unit that shows successes and mistakes, certainties and doubts. For instance, besides an innovative speech seeking to reassure that teaching is a profession and not a simple vocation or mission, some discourse and attitudes are identified that point to the opposite direction, extolling the school as extension of the family, defending a parental relationship with the students, and looking at certain aspects of daily school life as “sacramental”. However, in the light of science such ambiguities and incoherences are inherent to common sense discourse, where the influences of the patterns and cultural references are present in the process of identity construction of the group, which was confirmed by the research of their social representations of family and school
Resumo:
This work was developed in the course of Pedagogy, Universidade Federal do Rio Grande do Norte. Aims to understand the process of identity construction of teachers and educators in initial training. We started from the idea that such process was made by a complex and interdependent movement, once it was an inventive phenomenon wrought by individuals who are authors and actors of the story of their "real life" (KAUFMANN). This identity is rooted in the trajectories and social biographical experiences (FERREIRA), relationships with the constructed and accumulated knowledge in this route (CHARLOT) and in the developing of a sense of cultural belonging institutionally constructed (Luckmann, Berger). Then, the training involves relationships with knowledge in several instances, considering the effects, in one hand, the historic-social production and, in another hand, from the positions of subject and their biographical itinerary, existential and formative. We used the methodology of the Comprehensive Interview (KAUFMANN; SILVA), associated with a network of theoretical references, empirical and very analytical and interpretive activity. She researcher also relied on the "sensitive listening" (BARBIER), empathic attitude of "listening / seeing" the subject, and the notion of "intellectual artisan" (MILLS). The individual interviews were supplemented by the Focus Group. The approach was multi-referential (ARDOINO; MACEDO), with the intertwining of different perspectives, allowing a more complex configuration and less reductionist. In the analysis and interpretation we located the starting point, genesis of identity whose dynamics is not rigidly determined, but localized in space-time that precedes entry into the initial training. It is the time of concerns, questions and reflections about what you want to be in the future professional life. In sequence, we saw the route, multifaceted process whose the direction is the increasing involvement of individuals with their training. This training is engendered by the relations with the curricular, extracurricular and discursive knowledge, as simultaneous dynamics of self training and socio training. The self training of the individuals, understanding the critical, ethic and authority reading of their own experiences, is also seen as an exercise of shared responsibility, it assumes that the relationship with others meanings and professor mediation. The socio training refers to the collective subject and turns to the historical production and diversified knowledge, and comprehension of the various training instances. Self training and socio training are both objects of negotiation, because they are provocative of new designs, and cultural and identity maps, mobilizing the senses towards new meanings of themselves and the professional reality. It is in this interdependence between what is historically produced and the experiences of the subjects, who we located the arrival, considering it as a radically incomplete process of the professional identity and the building itself.
Resumo:
In the last three decades, the subject of the teacher's social identity has been discussed under various theoretical focuses, not only in Brazil, but also beyond our borders. In this thesis, the theme is approached starting from the theoretical proposal that has been developed by Domingos Sobrinho (1994), which is strongly based in the epistemological approach between Pierre Bourdieu s praxiology and the Theory of the Social Representations formulated by Serge Moscovici. It presupposes that this would make it easier to apprehend the process of construction of social identity of the investigated social group. The universe of the research is constituted by teachers of the fundamental teaching of the municipal district of Maracanaú, state of Ceará, that were active in class-room work there during at least three years, and were registered or had concluded the Course of Educational Formation promoted by UECE in that municipal district. Taking into account that the teacher's social identity is a process in permanent construction, resulting of their daily experiences and of the interferences originated from of the social context, the investigative tasks were implemented in two different stages, although they complement each other. Initially, with the objective of putting in evidence the genesis of the formation of that group s habitus, an analysis of the family and school lives of eleven teachers who participated in the course was made, using as main sources of data: thematic memorials, semi-structured interviews and observations - inside and out of the class-room during four school semesters. In the second stage a test of free association of words was applied to 426 teachers, seeking to apprehend the structure of the social representations of family and school a methodological strategy considered necessary to enhance and identify certain outlines of the habitus in study, besides being in agreement with the theoretical model followed. It became evident from the results that the identity of Maracanaú s teachers is molded and transformed into a multifaceted dynamic unit that shows successes and mistakes, certainties and doubts. For instance, besides an innovative speech seeking to reassure that teaching is a profession and not a simple vocation or mission, some discourse and attitudes are identified that point to the opposite direction, extolling the school as extension of the family, defending a parental relationship with the students, and looking at certain aspects of daily school life as sacramental . However, in the light of science such ambiguities and incoherences are inherent to common sense discourse, where the influences of the patterns and cultural references are present in the process of identity construction of the group, which was confirmed by the research of their social representations of family and school
Resumo:
We present here the results of a study whose objectives were to identify the social representation of being a professor of early childhood education in Campina Grande - PB, in the public state and municipal levels, and detect structural diagrams of a possible mental habitus of professorial faculty of education child, which would form the basis for the construction of this representation. As a theoretical base, we adopted the model developed by Domingos Sobrinho (1998, 2000, 2003, 2010, 2011), which articulates the Theory of Social Representations, Serge Moscovici, and the foundations and concepts of Pierre Bourdieu praxiology. It is based also on the Central Nucleus Theory, which focuses on the structural approach of social representations. Thus, puts in evidence the relational dynamics and symbolic, through which individuals come into contact, describe, understand and reproduce the outside world in his image and likeness. 199 teachers participated in the study of child care and pre-schools of Campina Grande - PB and 109 of the state. The methods and techniques used were: a) participant observation of everyday life of teachers of kindergartens and preschools, b) semi-structured interview, c) free associations of words with inducing the expression 'being a professor of early childhood education is ...' and d) semi-structured questionnaire. The data were analyzed in the case of interviews through the categorical content analysis, as proposed by Bauer (2010); free-associations, using the software Ensemble L'Analyse des Programmes Permettant evocations (EVOC), developed by Vergès (2002), which combines frequency and average order of recall (or association) and the questionnaire data, the Statistical Package for the Social Sciences (SPSS). It was verified the existence of a unique social representation shared by the population studied, but its content is structured differently. For local teachers, the centrality of the content is given by the elements commitment, dedication, responsibility, and rewarding teachers for this state revolves around the elements of love, patience, and rewarding responsibility. However, it is constructed mainly based on the related produced by a religious habitus and maternal habitus, which are part of the genesis of the establishment of professorial habitus in focus, among other cultural references of secondary influence. We conclude that a teacher of early childhood education actually researched, is materialized in the practices of educating and caring, in a clear fusion of the role of teacher and mother
Resumo:
The electric can be converted into thermal, luminous, electromagnetic, and also in mechanical energy. In this context the electric engines plays a fundamental role, specially that they work very below of its nominal capacity, with consequent decrease load density. In industrial environment, these characteristics of work of DC engines had also generated an extreme consumption of coal brushs and attack in the commutator reducing the useful life of the engine and increasing maintenance demand and cost. The general objective of the present work is to study the influence of the granulometry of the coal brush used in DC engines with the resistance to the consumption of the same ones, as well as in the performance presented by the commutator of the engine. Additionally, determining the measurable and not measurable profits when the brush used is adjusted to the application. The brushes had been produced by an industry of the sector and tested in industrial environment to evaluate their performance and consumption. Preliminary results evidence a substantial improvement in the performance of these brushes in function of its microstructure and the application in which it is used
Resumo:
The crude glycerine is a raw material that can be used in a wide variety of products. Even with all the impurities inherent in the process of being obtained, the crude glycerin is already in a marketable product. However, the market is much more favorable to the commercialization of purified glycerine. The glycerin is a byproduct gotten from the process of transesterification of waste oils and fats in the production of biodiesel. More recently, the deployment of the new Federal Law of Brazil, related to the implementation of energy resources, forces, from 2008, the increase of 2% biodiesel in diesel common with prospects for 5% (B5). Therefore, it is indispensable that new routes of purification as well as new markets are developed. The objective of this work was to purify, through ion exchange, the crude glycerin, obtained from the reaction of transesterification of cottonseed oil. The cottonseed oil was characterized as the fatty acid composition and physical-chemical properties. The process of ion exchange was conducted in batch. In this process were used strong cation, low anion resins and a mixed resin used to de-ionize water. The purified glycerin was characterized as the content of metals. Tests were performed with activated charcoal adsorption, and for this, it was made tests of time contact with coal as well as quantity of coal used. The time of activation, the amount of the activation solution, the contact time of the glycerol solution in resins, the amount and type of resin applied were evaluated. Considering the analysis made with activated charcoal, when the glycerin solution was treated using the resins individually it was observed that in the conditions for treatment with 10 g of resin, 5 hours of contact with each resin and 50 mL of glycerin solution, its conductivity decreased to a cationic resin, increased to the anionic resin and had a variable value with respect to resin mixed. In the treatment in series, there was a constant decrease in the conductivity of the solution of glycerin. Considering two types of treatment, in series and individually, the content of glycerol in glycerin pre-purified solution with the different resins varied from 12,46 to 29.51% (diluted solution). In analysis performed without the use of activated charcoal, the behavior of the conductivity of the solution of glycerin were similar to results for treatment with activated charcoal, both in series as individually. The solution of glycerin pre-purified had a glycerol content varying from 8.3 to 25.7% (diluted solution). In relation to pH, it had a behavior in accordance with the expected: acid for the glycerin solution treated with cationic resin, basic when the glycerin solution was treated with the anionic resin and neutral when treated with the mixed resin, independent of the kind of procedure used (with or without coal, resins individually or in series). In relation to the color of the glycerin pre-purified solution, the resin that showed the best result was the anionic (colorless), however this does not mean that the solution is more in pure glycerol. The chromatographic analysis of the solutions obtained after the passage through the resins indicated that the treatment was effective by the presence of only one component (glycerol), not considering the solvent of the analysis
Resumo:
This work whose title is "The transcendental arguments: Kant Andy Hume's problem" has as its main objective to interpret Kant's answer to Hume's problem in the light of the conjunction of the causality and induction themes which is equivalent to skeptical- naturalist reading of the latter. In this sense, this initiative complements the previous treatment seen in our dissertation, where the same issue had been discussed from a merely skeptical reading that Kant got from Hume thought and was only examined causality. Among the specific objectives, we list the following: a) critical philosophy fulfills three basic functions, a founding, one negative and one would argue that the practical use of reason, here named as defensive b) the Kantian solution of Hume's problem in the first critisism would fulfill its founding and negative functions of critique of reason; c) the Kantian treatment of the theme of induction in other criticisms would will fulfill the defense function of critique of reason; d) that the evidence of Kant's answer to Hume's problem are more consistent when will be satisfied these three functions or moments of criticism. The basic structure of the work consists of three parts: the first the genesis of Hume's problem - our intention is to reconstruct Hume's problem, analyzing it from the perspective of two definitions of cause, where the dilution of the first definition in the second match the reduction of psychological knowledge to the probability of following the called naturalization of causal relations; whereas in the second - Legality and Causality - it is stated that when considering Hume in the skeptic-naturalist option, Kant is not entitled to respond by transcendental argument AB; A⊢B from the second Analogy, evidence that is rooted in the position of contemporary thinkers, such as Strawson and Allison; in third part - Purpose and Induction - admits that Kant responds to Hume on the level of regulative reason use, although the development of this test exceeds the limits of the founding function of criticism. And this is articulated in both the Introduction and Concluding Remarks by meeting the defensive [and negative] function of criticism. In this context, based on the use of so-called transcendental arguments that project throughout the critical trilogy, we provide solution to a recurring issue that recurs at several points in our submission and concerning to the "existence and / or the necessity of empirical causal laws. In this light, our thesis is that transcendental arguments are only an apodictic solution to the Hume s skeptical-naturalist problem when is at stake a practical project in which the interest of reason is ensured, as will, in short, proved in our final considerations
Resumo:
The aim of this study was to investigate the social representation of technological education teachers at the Federal Technological Education Network. The survey was conducted from 2007 to 2010, and the respondents were 275 teachers, 135 of the Federal Center for Technological Education (CEFET in portuguese) in the state of Amazonas, in Manaus unit headquarters; 140 of the CEFET in the state of Rio Grande do Norte, a unit based in Natal. We adopt the concept of technological education as the top level of professional education, that is to say, the undergraduate programs of short duration called technological courses. The Federal Technological Education Network gathers hundreds of related institutions, coordinated and supervised by the Office of Vocational and Technological Education of the Ministry of Education. Although many of these institutions offer courses in technology education, no research addressing this subject from the perspective of Social Representations Theory (SRT) was found in the literature. We seek to unravel the social representation of technological education of the teachers by adopting the procedural approach of SRT. This is a qualitative approach, focusing on significant aspects of the representative activity and the formation mechanisms of the representation. Therefore, we search the socio-genesis of the representation in the articulations between discourses, social institutions and practices. We initiated the research through applying critical reading and an analytical perspective on the historical and regulatory documents of technological education in Brazil, from the early twentieth century to the present day. We adopt the Procedure for Multiple Classifications (PMC) from the Free Words Association Technique (FWAT) to access the elements of representational content. For the analysis of the data obtained with FWAT and selection of major words / phrases pertinent to the semantic field of education technology, we used Hamlet II software. For the data analysis of PMC and Free Classification (FC) we used the SPSS ® (Statistical Package for the Social Sciences) version 17.0 and used the method of multidimensional scaling - Multidimensional scaling - (MDS). The output from the central MDS takes the form of a set of scatterplots - "perceptual maps" - of which the points are the elements of the representational content. For the FC data analysis we used the Scalogram Multidimensional Analysis (SMA) - which makes use of the original data in its raw form and allows categorical data to be interpreted in the map as measures of (di)similarity. In order to help with the understanding of the settings of the perceptual maps of FC, we used the Content Analysis of the discourse fragments of the teachers interviewed. The results confirm our initial hypothesis regarding the presence of a single plot among the socio-cognitive study subjects, which is the basis for a social representation of technological education in line with the historic assumption of the dichotomy between mental and manual labor. In spite of the three merging representational elements of the representational content, the perceptual maps compiled from the MSA statistics corroborates the dichotomy, with the exception of the map relating to the subgroup of teachers belonging to the humanities
Resumo:
The genesis of the research emerges from reflection about the space dynamics of the capital and to the capital. The expansion and the incorporation of territory for capital reveal, in part, strategies of the capitalism production way, which shows the search for accumulation conditions, expanding the alternatives of territory use that is, nowadays, selective and uneven. The present work verified the mechanisms where the capital imposes its practices through the agrarian structure and the valuation of land market, meaning, in our knowledge, that the reproduction of inequalities is showed, many times, by the wide land speculation and the fast land valuation. For this, the snip space will be the Sibaúma community, belonging to Tibau do Sul district, located in Rio Grande do Norte state. It‟s a rural area that has, gradually, changing through the advent of urban characteristics, given the association of public and private investments, both domestic and international. Through the empirical observations, inside the Sibaúma community, it was found expansion strategies, incorporation and appropriation of territory by capital. As a result of this practice, it‟s occurring the land valuation and the presence of a process of socio-spatial segregation, through the encouraging the opening of new subdivisions, mainly for construction of second homes and tourism enterprises in order to meet the demand of a higher socioeconomic level. The areas still available in Sibaúma, constitute into a reserve of value for the achievement of capitalist rent, being a mechanism of capital reproduction. In this way, to studying the socio-spatial transformations, caused by spatial valuation, we turn to the project of social space designed by Santos(2006), from the perspective of capitalist production of space, by understanding the historical process of formation, the mechanisms and the actions of social actors that produce and consume space