Obtenção de uma porcelana dielétrica a partir de matérias-primas do Rio Grande do Norte

The dielectric porcelain is usually obtained by mixing various raw materials proportions and is used in the production of electronic equipment for various applications, from capacitors of high and low Power to insulators for low, medium, high and extra high voltage, which are used in distribution lines and transmission of electricity.This work was directed to the s tudy of technological properties of technic porcelain, made from raw materials extracted from pegmatites found in the regions of Seridó and the Alto Oeste of Rio Grande do Norte, which are made of kaolin, quartz and feldspar, abundant and high quality in these regions. The technic ceramics were obtained by mixing in appropriate levels, kaolin, feldspar, quartz and clay, the last item from a pottery in the city of Sao Gonçalo do Amarante, Rio Grande do Norte. During the development the following characterizations correlated to raw materials were made: laser particle sizing, x-ray diffraction, DTA and TG. The compositions studied were formed by uniaxial pressing at a pressure of 50 MPa and sintered at temperatures ranging from 1150 to 1350ºC and levels (times) of sintering between 30, 60, 90 and 120 minutes. The characterization of the samples were taken from the analysis of weight loss, linear shrinkage, porosity, stoneware curve, bulk density, flexural strength of three points, SEM and X-ray diffraction, TMA, Dielectric and cross Resistivity. The studied materials can be employed in producing the objects used in electrical engineering such as: insulators for low, medium and high-voltage electrical systems, command devices, bushing insulation for transformers, power capacitors, spark plugs, receptacles for fluorescent and incandescent light bulbs and others

O PROEJA ensino médio no ifrn, campus Caicó: causas da desistência e motivos da permanência

This dissertation deals about the theme of National Integration Program of the Professional Education to the Basic Education in the form of Youth and Adults Education - PROEJA, which was developed at the Federal Institute of Education Science and Technology of Rio Grande do Norte - IFRN - Campus Caicó. It aims to analyze the causes of the abandonment and the reasons for the permanence of students within the mentioned program. To substantiate this research, we used methodologically, some procedures such as bibliographical research, documentary analysis, semi-structured interviews and focus group. To analyze the data, we discussed the contradiction that involves duality and educational compensation based in the struggles and achievements of rights at the core of public policies for high schools, for vocational education and the education of youth and adults in the 2000s. We analyze the integrated high school under PROEJA, having as reference the conception of the total human formation; the inseparability of the primary education system and vocational education and the integration of knowledge and expertise as a whole, discussing the specificities of the modality EJA, discussing the causes of abandonment and the reasons for the permanence of the students of education for youth and adults (EJA) in the primary education system. As for the results, we found that although the PROEJA be a program that aims to provide a complete human formation to contribute to the full citizenship of their graduate members, what is announced in the document that guides its creation has not been materialized in Caicó Campus. The curriculum of the course was not designed for the students of EJA, nor teachers have had an adequate training to work with these specific individuals, and its specificities of being workers with differentiated learning times have not been considered. In addition, the courses are predominantly of instrumentalist characteristics. This indicates that the material and institutional conditions to achieve the promised total and complete training have not being fully materialized at the researched school. Associated with the difficulties concerning the intra-school and extra-school conditions, personal and socioeconomic conditions which are related to the obligation to work that implies in limitations to balance work, school and family, they influenced in the interruption of the school trajectory of these subjects. Through research, we confirmed that the motives of students who remain have to do also with intraescolares conditions the quality of education (qualification of technical staff and teachers) involved in the educational process, as well as socioeconomic and personal issues represented by the support of colleagues and family.Then it is concluded that the causes of abandonment and the reasons of the permanence are of institutional, socioeconomic and personal origins. Finally, it is observed that capitalist society demands as much as possible high levels of educated workers, and at the same time makes difficult the access to that education for much of the population, and it is not randomly. The objects of that exclusion are the popular worker classes and their children

Sistema de gestão ambiental sob a perspectiva da resource-based view: um estudo de caso no verdegreen Hotel - João Pessoa/PB

The pressure for a new pattern of sustainable development began to require of modern organizations the conciliation between competitiveness and a environmental protection. In this sense, a tool that acts in the implementation of structured strategies is the Environmental Management System (EMS), which focuses on improving environmental performance. This improvement, in turn, can generate to the organizations many benefits , among which, obtaining competitive advantages, susceptible of measurement from different perspectives. One of these is the application of VRIO model, reasoned by the Resource-Based View (RBV), which considers that differences between companies occurs due to differences between its internal resources and capabilities. However, although was been found some studies in the literature that evaluate the competitive potential of certain organizations , such assessments are not performed on specific objects, like the SEM s. Thus, the aim of this study was to evaluate the resources and capabilities (environmental strategies) adopted by the SGA of the Verdegreen Hotel, identifying which of these have the potential to generate competitive advantage. For this, this exploratory-descriptive character study and delineated as field research and case study was used as data collection tools: a literature survey, semi-structured interviews, document research and participant observation. The interpretation of results and consolidation of information were conducted from a qualitative approach, using two techniques of data analysis, namely: content analysis and analysis through VRIO model. The results show that the hotel is quite structured in relation to their EMS, as well as reaching related to improving the management of environmental factors, strengthening the image and gains in competitiveness benefits. On the other hand, the main difficulties for the implementation of the system are related to employees and suppliers. With regard to environmental strategies adopted, of the 25 strategies identified, 10 showed the potential to generate competitive advantage

Caracterização numérica de antenas para aplicações RFID utilizando o método das ondas - WCIP

In recent years, the radio frequency identification technology (RFID) has gained great interest both industrial communities as scientific communities. Its ability to locate and monitor objects, animals and persons with active or passive tags allows easy development, with good cost-benefice and still presents undeniable benefits in applications ranging from logistics to healthcare, robotics, security, among others. Within this aspect what else comes excelling are RFID tags and the antennas used in RFID readers. Most tags have antennas omnidirectional and are usually manufactured as dipoles modified printed. The primary purpose of a project of antenna for tag is to achieve the required input impedance to perform a good marriage impedance with the load impedance of the chip. Already the objective principal in project of antennas for readers is to achieve reduced sizes and structures with good data transmission capacity. This work brings the numerical characterization of antennas for RFID applications, being these divided into tags RFID and antennas for RFID readers. Three tags RFID and two antennas for RFID readers, found in literature, are analyzed. The analysis of these structures is made using the Method of Waves - WCIP. Initial results found in the literature are compared with those obtained through simulations in WCIP with objective to show that the Method of Waves is able to analyze such structures. To illustrate the results obtained in simulations is presented the behavior of electric and magnetic fields. It also performed a literature review on the characteristics and principles of RFID technology. Suggestions for continuity to this work are presented

Desenvolvimento de um Sistema de Visão Global para uma Frota de Mini-Robôs Móveis

Navigation based on visual feedback for robots, working in a closed environment, can be obtained settling a camera in each robot (local vision system). However, this solution requests a camera and capacity of local processing for each robot. When possible, a global vision system is a cheapest solution for this problem. In this case, one or a little amount of cameras, covering all the workspace, can be shared by the entire team of robots, saving the cost of a great amount of cameras and the associated processing hardware needed in a local vision system. This work presents the implementation and experimental results of a global vision system for mobile mini-robots, using robot soccer as test platform. The proposed vision system consists of a camera, a frame grabber and a computer (PC) for image processing. The PC is responsible for the team motion control, based on the visual feedback, sending commands to the robots through a radio link. In order for the system to be able to unequivocally recognize each robot, each one has a label on its top, consisting of two colored circles. Image processing algorithms were developed for the eficient computation, in real time, of all objects position (robot and ball) and orientation (robot). A great problem found was to label the color, in real time, of each colored point of the image, in time-varying illumination conditions. To overcome this problem, an automatic camera calibration, based on clustering K-means algorithm, was implemented. This method guarantees that similar pixels will be clustered around a unique color class. The obtained experimental results shown that the position and orientation of each robot can be obtained with a precision of few millimeters. The updating of the position and orientation was attained in real time, analyzing 30 frames per second

O Uso de operações linguístico-discursivas da crítica genética na reescritura de textos

As a professor in Curso de Licenciatura em Letras, from Campus Avançado Profa Maria Eliza Albuquerque Maia (CAMEAM),do Estado do Estado do Rio Grande do Norte (UERN), in the town of Pau do Ferros, in the state of Rio Grande do Norte, we had the chance to carry out several writing activities , as well as guiding re-writing activities for the texts produced. From this experience, we started looking at the need of reflecting upon the writing process in higher education. Thus, we aim at analyzing, in this research, the methodology used in the moment of carrying out the writing practices activities in higher education, investigating, in particular, the rewriting practices, concerning the operations used for carrying out such activities, as well as the sense effects produced from the alterations which were made in the texts. Our theoretical foundation is grounded on a conception of text as a verbal action , what reveals a socio-interactional view of the language (MARCUSCHI, 2008; SAUTCHUK, 2003). As the production of written texts, our research focus, we assume that, for this activity, we deal with distinct figures (active writer and internal reader), so that we can, apart from writing, reflecting upon our writing and, this way, deciding about operations which are carried out to make the alterations which are necessary to the rewriting of our texts (SAUTCHUK, 2003). Still about the theoretical foundations used in this research, we made use of the theories from the Textual Analysis of Discourse (TAD) which discusses the belief on the evidence on the existence of the texts, which is opposite to the fixist view of textuality which believes that the texts exist by themselves. (ADAM, 2008; [2005]2010). Under this perspective, we have also adopted, the concepts which come from genetics criticism which is concerned about the relation between text and genesis, using as objects documents which bring traits of the text in progress, on the ground that the text is the result of work in progress, and the writing practice, on the other hand, as an activity in a continuous movement (HAY, [1975]2002; DE BIASI, [2000]2010; GRÉSILLON, 1989; [1990]2008; [1992]2002; SALLES, 2008a). The methodology in this research is an ethnography-based one, an approach which focuses on the process, as well as is meaning-based. To understand the objectives proposed in our research, we made use of different procedures of collecting data which include an ethnographic study, such as: observation, note-taking, document analysis. The data which were analyzed were collected during the semester of 2008.2, in a first term classroom of Curso de Letras from CAMEAM, when we were able to collect twenty-one written texts and all of them were rewritten based on rewriting activities, what provides a corpus of forty-two texts which will be analyzed based on the linguistics operations identified by Generative Grammar and adopted by Lebrave and Grésillon (2009). From these analyses, we were able to confirm that writing is a process, and rewriting has become an extremely important activity for this process. Still due to these data, we observed that substitution was the most used operation by text authors. We believe that this result is justified by the fact that the substitution, according to what proposes the Genetic Criticism, constitutes the source of all erasure, from which one can easily make a change in writing. Regarding the operations of addition and deletion, we found that they were used in quantitative terms, almost equivalently, which can be explained when we see that the two operations require, by the author of the text, different strategies from those used for the replacement, what includes , respectively, adding or removing a segment. Finally, we found out that the shift operation was the least used, since it works with a segment that will not be replaced, added or deleted, but transferred to another place of text, which requires a greater ability of the author to perform this operation and not compromising the meaning of his/her writing. As a result, we hope to contribute to the reflection on the teaching of writing, considering, in a particular way, those with a Bachelor in Arts. Our analysis will contribute to the teaching of Portuguese language, specifically for activities that guide the production of texts in order to explore with students the ability to rewrite their own text

Análise textual dos discursos: responsabilidade enunciativa no texto jurídico

This investigation aims at describing, analyzing and interpreting the Commitment in Initial Petitions, which is a genre circumscribed in the judicial domain. For this purpose, we have chosen sections, facts as found and relevant law , sections of the petition, with the understanding that, in this way, respectively, the narration of events, which gives margin to the propositioning to the judicial action, and the exposition of the law that upholds the author s intention. We base our discussion on the field of Linguistics, more precisely, Textual Discourse Analysis (TDA), whose theoretical basis is derived from Textual Linguistics (TL) and Enunciative Linguistics. We foreground, particularly, the way in which the author of texts, objects of analysis, use discursive strategies that evidence ER. The relevance of this study, then, is in the formation of a critique of the judicial text, as it conceives of a dialogical approach to the point of view, raising not only questions about the way in which a linguistic instance conceives an object of discourse, but also considering questions of language inherent to technical writing and, in this aspect, contributing to the work of those operating in Law about the many ways ER is formed in the body of a petition. We selected two categories to analyze that, according to Adam (2011), characterize the degree of ER in the textual material of the propositional enunciations: the different types of representation of speech and the indications of profile of mediators. In this sense, with this task as an objective, we base our study regarding point of view on Rabatel (2003, 2009a, 2010) with relation to the enunciative approach, including the study of PDV in polyphonic and dialogical theoretical framework to study the ER from different types of speech representations that conceive forms of transmission of discourse and the role of the enunciating subject, mainly the responsibility and the prerogative by the propositional contents. In the same way, intending to study the indications of the mediator profiles, we observed the postulations of Guentchéva (1994, 1996), which develop the notion of mediative grammatical categories, of which permit the linguistic marking of distance and engagement of the enunciator with regard to the information expressed. The methodology we adopted was based on qualitative research, of an interpretive and introspective nature, in light of the fact that his study focuses on processes and strategies underlying language use. The corpus of the research is comprised of Initial Petitions, which gave rise to actions originating in the Civil Court of Currais Novos County RN. The data analysis shows that an object of discourse is always perspective oriented and presents the point of view of one or more enunciators. Consequently, the producer of a text, using the PDV of other enunciators, influences and establishes the argumentative orientation of the text. In the same way, it evidences the relevance of the use of mediated constructions in the judicial text, as they function as strategies attenuated to the responsibility of the producer of the text with what is said, and at the same time points to a discourse of authority through the entrance of the sources of law. Moreover, it reveals the documental and international importance of this practice, at the same time that it exposes the compositional and normative difficulties with regard to legal and linguistic aspects

Evolução de Rádio Fontes Duplas Extragalácticas

Double radio sources have been studied since the discovery of extragalactic radio sources in the decade of 1930. Since then, several numerical studies and analytical models have been proposed seeking a better understanding of the physical phenomena that determines the origin and evolution of such objects. In this thesis, we intended to study the evolution problem of the double radio sources in two fronts: in the ¯rst we have developed an analytical self-similar model that represents a generalization of most models found in the literature and solve some existent problems related to the jet head evolution. We deal with this problem using samples of hot spot sizes to ¯nd a power law relation between the jet head dimension and the source length. Using our model, we were able to draw the evolution curves of the double sources in a PD diagram for both compact sources (GPS and CSS) and extended sources of the 3CR catalogue. We have alson developed a computation tool that allows us to generate synthetic radio maps of the double sources. The objective is to determine the principal physical parameters of those objects by comparing synthetic and observed radio maps. In the second front, we used numeric simulations to study the interaction of the extra- galactic jets with the environment. We simulated situations where the jet propagates in a medium with high density contrast gas clouds capable to block the jet forward motion, forming the distorted structures observed in the morphology of real sources. We have also analyzed the situation in which the jet changes its propagation direction due to a change of the source main axis, creating the X-shaped sources. The comparison between our simulations and the real double radio sources, enable us to determine the values of the main physical parameters responsible for the distortions observed in those objects

Geoquímica de sedimentos de fundo dos rios Trairí, Ararí e da Laguna Nísia Floresta (RN)

The metal concentrations (Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn ) and phosforus(P) had been determined analyzed through Plasma Inductively Coupled Plasme Mass Spectrometer for fine fraction, < 0,63 mm in 22 samples. The sample preparation for analysis had been make in the laboratories of geology of the UFRN. This samples procedures consists in register, dry, bolt and send to analysis in external laboratory (LAKEFIELD GEOSOL) in Belo Horizonte (MG, Brazil). The studied area involves the rivers Trairi, Ararí and Nísia Floresta lagoon, that empties in the sea, situated in the Rio Grande do Norte State. The study objects (Rivers Trairí, Ararí and Nísia Floresta lagoon) receive influences from urban dumpies, agrotoxics and fertilizer, shrimps tank, pastoral, with this, the concentrations of metals (Al, Ba, Cd, Cr, Cu, Fe, Mn, Ni, Pb, P, Zn) (except phosforus) in some points of the study area had been above of the value of reference what it leads to classify them as not polluted to moderately polluted, as the calculated Igeo. In front of discussed, can say about the environmental problems found in Trairi, Ararí and Nísia Floresta Lagoon are still in small scale, since when regard the studied área is over human activity effects

Detecção de predadores por dicromatas e tricromatas humanos e a sua implicação na evolução da visão de cores em primatas

Among placental mammals, primates are the only ones to present trichromatic color vision. However, the distribution of trichromacy among primates is not homogeneous: Old World primates shows an uniform trichromacy (with all individuals being trichromats) and New World primates exhibit a color vision polymorphism (with dichromatic males and dichromatic or trichromatic females). Visual ecology studies have investigated which selective pressures may have been responsible for the evolution of trichromacy in primates, diverging from the dichromat standard found in other mammals. Cues associated with foraging and the socio-reproductive status were analyzed, indicating a trichromatic advantage for the rapid detection of visually conspicuous objects against a green background. However, dichromats are characterized by an efficient capture of cryptic and camouflaged stimuli. These advantages regarding phenotype may be responsible for the maintenance of the visual polymorphism in New World primates and for the high incidence of color blindness in humans (standing around 8% in Caucasian men). An important factor that has not yet been experimentally taken into account is the predation risk and its effect on the evolution of trichromacy in primates. To answer this question, we prepared and edited pictures of animals with different coats: oncillas (Leopardus spp.), puma (Puma concolor) and ferret (Galictis cuja). The specimens were taxidermized and the photographs were taken in three different vegetation scenarios (dense forest, cerrado and grassland). The images of the predators were manipulated so that they fit into two categories of stimulus size (small or large). After color calibration and photo editing, these were presented to 40 humans (20 dichromats and 20 trichromats) by a computer program, which presented a set of four photos at a time (one picture containing the taxidermized animal amid the background vegetation and three depicting only the background vegetation) and recorded the response latency and success rate of the subjects. The results show a trichromatic advantage in detecting potential predators. The predator detection was influenced by the background, the predator species, the dimension of the stimulus and the observer s visual phenotype. As humans have a high rate of dyschromatopsias, when compared to wild Catarrhini or human tribal populations, it is possible that the increased rate of dichromats is a result of reduced pressure for rapid predator detection. Since our species came to live in more cohesive groups and resistant to attack by predators, with the advent of agriculture and the formation of villages, it is possible that the lower risk of predation has reduced the selection in favor of trichromats

Desenvolvimento territorial e a política nacional de água em Moçambique: o caso do distrito de Chibuto

The development has been a phenomenon in constant discussion today, whose fundamental importance should be to promote the welfare of humanity. Thus, the development becomes an element that adds political, economic, social and environmental values . In Mozambique the development model adopted by the State prioritizes the economic dimension, in this case favoring the growth of capitalist structure production. Thus , the basic conditions for human survival still leaves much to be desired and the Mozambican population in general and the district of Chibuto , in particular , continue to face several difficulties to have access to such conditions, and the lack of potable water is a that most of the problems afflicting this population . The water was always a factor related to the socio-economic development of the population, where great civilizations and major economic marks were always influenced by water availability, and today this feature is present in all sectors of production. In Mozambique, much effort has been made by the government, national and international organizations to enhance and guarantee the supply of potable and drinking water, and despite all this effort, most of the population does not have access to this precious resource. In this sense, this work presents an analysis of the effects of the National Water Policy in the study area, analyzes the shortage of potable water in the district of Chibuto, discusses the design and development contained in the official discourse of the state and, opposes the idea of human development. For such issues that help to understand the phenomenon under study, such as territory, public policy and criticism of hegemonic conception of development are addressed. To make the desired approach, we performed a characterization of the District of Chibuto, addressing the issue of poverty, with a brief discussion of this concept, from different approaches, and analyze the impact of the PARPA (Action Plan for the Reduction of Absolute Poverty) in fighting poverty in Mozambique, and became a description of the scenario of poverty and vulnerability in Chibuto district with the construction of Territorial Human Development Index. Research also brings up a discussion about territory and technicization which describes the senary of the water supply system in the District and territorial dynamics of Chibuto, from the analysis and description of existing structures and other technical objects that structure the territory under study. Thus, it was found that the development should be summarized in the satisfaction of human needs, and should be the cornerstone of the new type of development that is intended for the purpose of triggering urgently actions to overcome or combat bleak misery suffered by the majority of inhabitants of the District of Chibuto

Experience-dependent upregulation of multiple plasticity factors in the hippocampus during early REM sleep

Sleep is beneficial to learning, but the underlying mechanisms remain controversial. The synaptic homeostasis hypothesis (SHY) proposes that the cognitive function of sleep is related to a generalized rescaling of synaptic weights to intermediate levels, due to a passive downregulation of plasticity mechanisms. A competing hypothesis proposes that the active upscaling and downscaling of synaptic weights during sleep embosses memories in circuits respectively activated or deactivated during prior waking experience, leading to memory changes beyond rescaling. Both theories have empirical support but the experimental designs underlying the conflicting studies are not congruent, therefore a consensus is yet to be reached. To advance this issue, we used real-time PCR and electrophysiological recordings to assess gene expression related to synaptic plasticity in the hippocampus and primary somatosensory cortex of rats exposed to novel objects, then kept awake (WK) for 60 min and finally killed after a 30 min period rich in WK, slow-wave sleep (SWS) or rapid-eye-movement sleep (REM). Animals similarly treated but not exposed to novel objects were used as controls. We found that the mRNA levels of Arc, Egr1, Fos, Ppp2ca and Ppp2r2d were significantly increased in the hippocampus of exposed animals allowed to enter REM, in comparison with control animals. Experience-dependent changes during sleep were not significant in the hippocampus for Bdnf, Camk4, Creb1, and Nr4a1, and no differences were detected between exposed and control SWS groups for any of the genes tested. No significant changes in gene expression were detected in the primary somatosensory cortex during sleep, in contrast with previous studies using longer post-stimulation intervals (>180 min). The experience-dependent induction of multiple plasticity-related genes in the hippocampus during early REM adds experimental support to the synaptic embossing theory.