Caracterização de escovas de grafite e avaliação do seu desempenho em função da microestrutura

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

Caracterização espacial de reservatórios do semiárido em função da qualidade da água através do uso de componentes principais

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

Investigação histórica na formação de professores de matemática: um estudo centrado no conceito de função

In this study we analyzed the development of a teaching experience, involving students with a bachelor s degree in mathematics from UFRN, based on the history of mathematics and mathematical investigations with the aim of contributing to the improvement of the teaching-learning of mathematics. The historical investigation tasks were planned and applied in the classroom, focusing on functional thought. The results obtained during the experience were described and evaluated based on authors who support the assumption of investigation and history as an alternative to the learning of mathematics. We emphasize that the material of analysis consisted of a work diary, audio recordings, questionnaires with testimony of the students involved, and, in addition, the assessment of the teacher of that subject. With regard to the mathematical content, the study was restricted to the concept of function, forms of representation and notation. It was evident that students showed great improvement with regard to the necessary formalization of the mathematical contents which were focused on, and to the active involvement of the students at different stages of the study. We can affirm that the completed study certainly represents significant contributions to an approach in the teaching-learning of functional thought

Formas e função do discurso do outro no gênero monográfico

The present work investigates related discourse in rewriting discursive practices, at monographic works specifically at the theoretical foundation section. Focalizing some discursive strategies of voice management (direct and indirect discourse and modalization voice) we detach the introduction way and function of cited discourse. To do so, it were analyzed eighteen monographic works: nine of them final graduation works and other nine specialization works seeing that each works belonging to the same student, in two different stages, in the period from 2003 in graduation conclusion to 2005 in the end of specialization course. The data reveal that the monographic writer/student emphasizes the use of direct discourse in graduation works while in specialization works there was an emphasis at indirect speech. The analysis the way they introduce cited discourse pointed out that writer/student in graduation course such as specialization student make meaningless constructions when they do not use discendi verbs, they demonstrate difficulties inarticulate citing discourse with cited discourse. In what is related to functions of cited discourse we verify that the student/writer, in both stages or levels give emphasis to the function maintain an assertion, indicating that other s discourse serve mainly as a resource of authority just because that this function reveals the absence of a dialog between student writing and cited discourse. In a general way, the forms of other s discourse claim a form of writing that is found starting from a sequence of cited discourse in what student/writer voice in graduation and specialization comes to text surface just few times, but most of the times, the student takes other s words as they were themselves, every time there is an overlap of author/source

João Cabral de Melo Neto: a estética do avesso

La pieza-poema Morte e Vida severina Auto de natal pernambucano, de João Cabral de Melo Neto, publicada en 1956, es el principal objeto de este estudio, interaccionando con las obras O Cão sem plumas y O rio por la similitud temática entre ellas: el estudio sobre esas obras busca una lectura desvinculada del posicionamiento constructivista y metalingüístico que por tradición configura la obra cabralina, no por negar a la crítica literaria que da respaldo científico, pero con la pretensión de lanzar una nueva mirada dirigida para el concepto de barroco, materia ésta que implica la creación poética a partir de la segunda mitad del siglo XX. Por lo tanto, este trabajo presenta una propuesta de análisis de la poesía de João Cabral a partir del contexto neobarroco. Considerando, sobre todo, los aspectos similares a la temática del barroco, el enfoque recae sobre la influencia de la literatura ibérica por que pasa el poeta João Cabral, así como la temática sobre el conflicto existencial explorado en el texto Morte e Vida severina, y aún, los extractos de lenguaje con significación múltiple que presentan signos metonímicos y metafóricos.

Cinge a musa o oráculo da tradição: revelações perenes da narrativa em contos de Perrault

Le présent ouvrage comprend des versions comparatives de neuf contes de Perrault, parmi les plus célèbres, publiés dans des éditions intégrales, au Brésil, entre 1934 et 2005. L analyse comparative donne la priorité à l identification des éléments relatifs à l oralité, comme ceux qui appartiennent, selon Ong (1998) et Havelock (1996), à des contextes de cultures antérieures à l épanouissement de l écriture et qui donc élaboraient ses propres structures de pensée et d expression pour interagir dans la vie pratique comme dans la création, dans la transmission et la manutention des coutumes et traditions. Issus des premiers récits, les contes de Perrault, traduits ou adaptés au Brésil, gardent en eux l esprit du langage narratif auquel l auteur français a consagré une attention spéciale, pour transposer dans l écrit quelques récits de la grande expérience humaine née dans le milieu populaire et qui désormais intègrent l espace de l écriture à chaque nouvelle version produite. Les bagages formulaires, comme les épithètes, les interventions du narrateur et la propre relation des signifations de l intrigue avec les structures de l imaginaire toujours présentes dans l humanité, démontrent le rapprochement entre l oralité et écriture. En suivant les discussions théoriques de Zumthor (1993, 1997, 2000) et par l interation du lecteur avec le texte, on constate que ces éléments relatifs à l oralité rendent possibl existence d une performance dans l écrit a partir des impressions cinesthésiques qui chaque lecture provoque chez le lecteur et récepteur d un texte narratif qui revendique, automatiquement, la construction d une ouvrage seulement possible à chaque instant de l interation, par le processus esthétique de la réception. Même au niveau d écrit, ou l intensité de sa présence est diminuée en raison de l absence d un corps physique qui transmet, qui développe, qui opere littéralement le texte par la voix et qui réunit l écoute et la vision de l auditeur, la performance produite s interpose entre le corps du lecteur qui agit sur le texte et en même temps reçoit les sensations lui permettant l expérience esthétique. Ainsi, dans l expérience de la lecture de Contes de Perrault est possible percevoir les éléments qui renvoient à la forme du conte de tradition populaire. Même déjà influencée par l écrit, le lecteur peut identifier, dans cette oeuvre, les possibilités determinantes de la dynamique perpétuel dans la transmission de ses textes: le plaisir de la pratique de l écoute des histoires contées oralement et le plaisir de la pratique de lectures silencieuses et solitaires. Dans ce chemin le lecteur devoit chercher les sens perdus, ici, rencontrés avec l aide des discours littéraires, linguistique, folklorique, anthropologique et psycanalytique sur la surface du texte narratif merveilleux. Outre cela, ces discours collaborent avec le lecteur qui retrouvent les voix emprisonnées par l écrit dans la virtualité et dans émergence d une performance

Iracema: a alegoria da mãe genti(o)l

A abordagem da visão da literatura nacional dentro do contexto cultural brasileiro da segunda metade do século XIX e do posicionamento crítico de José de Alencar fez, de sua produção romanesca, especialmente a indianista, representada aqui por sua obra Iracema, um símbolo do conjunto de intenções nacionalistas que invadiu a alma e o coração de todo o povo, no que diz respeito ao sentimento de brasilidade , condizente com a estética romântica da qual faz parte seu autor. Seu posicionamento, quer seja crítico ou artístico, faz de Alencar o maior polemista em defesa da liberdade cultural e literária do Brasil, enquanto alguém bem consciente de sua função social, e por que não dizer, crítica, identificando a metalinguagem como um diferencial fomentador de uma teorização de poética na defesa de sua ficção, abrindo caminho, assim, para a pesquisa da poética explícita na sua produção artística. A referida análise buscará, a partir de uma análise estrutural das partes formais que o compõem esteticamente, como também de uma compreensão temática dos ditos e interditos utilizados pelo narrador alencariano na composição de seu discurso, identificar Iracema enquanto um romance que disputa o título de obra fundacional do Brasil. Para isso se faz necessário empreender uma abordagem do como e do quanto os elementos da Natureza, num romance romântico que tem a Natureza enquanto uma de suas temáticas mais significativas, podem constituir e interferir na percepção e construção de um personagem, que é todo Natureza, e no meio natural em que ele vive; até mesmo ser, por causa disso, o elemento mais representativo dessa nação que se deseja criar, trazendo para o cenário cultural brasileiro do século XIX uma versão de instituição baseada no revigoramento da memória da cultura selvagem. Faz-se lícito também animar forças da natureza e da terra-paisagem que poderiam ser tidas, apenas, como exóticas, mas que na obra em questão funcionam como protagonistas, mesmo fantasmas, de um pacto social e político que, mesmo quando rompe, recusa-se em deixar romper, mergulhando no espaço romanesco da magnitude das águas ou na frieza tumular da terra. Tomar-se-á, também, como ponto de estudo, a análise da fusão da experiência histórica com a experiência ficcional, observando o imbricamento de um discurso no outro, como também as fronteiras que se estabelecem a partir dessa tentativa; tomando o erotismo e a alegoria como pontos de convergência na obra em questão. Por meio da verificação de uma relação que se constrói a partir da solidão, da memória e do esquecimento em que acabam por mergulhar todos os seus personagens, que são, por vezes, tragados em algum dilúvio bíblico da purificação, dentro de um projeto audacioso de invenção de uma nação, que se quer de identidade cultural, e também política, mas que termina condenado ao silêncio, não gozando de liberdade em relação ao espaço a que pertence e, no entanto representa, só cabendo a eles regressarem para dentro da terra-mãe, ou se submeterem a um ritual de profunda aculturação, verificar-se-á, através desse discurso historicamente construído, o ideário de uma nação que se almejava projetar. O conflito de Iracema, personagem protagonista de sua obra homônima, a negação e a perda de si mesma, de tudo aquilo que poderia representar a sua identidade social e cultural, e, conseqüentemente, a morte e a vida dessa mãe genti(o)l, simbolizam a vida e a arte de um povo que, passando pelos embates da colonização, através de seus artistas rebeldes e românticos da Independência, que ilustraram, em grande síntese, a visão através da qual o homem do Novo Mundo foi vislumbrado, rabiscou a imagem da americanidade pelo discurso da História

A estética transcendental kantiana à luz de Strawson

This work s objective is to make a literal interpretation of Kant s Aesthetic transcendental, the first pilaster of sustentation of the epistemology of Kant and to interpret it at Strawson s light. It contains the doctrine of sensitivity responsible for the intuitions, which rests on the concepts of space and time, and, with this, the tematização of two important questions. For Kant s philosophy in its epistemologic source what s the importance of the concepts of and time? How these concepts of space and time inscribe themselves with such statute as an investigatory task of metaphysics? The specification of the concepts of space and time as ingredients of the theories treated and enrolled in this work are segmented of the Aesthetic transcendental of Kant, and interpreted under Strawson s light. The research is divided in two chapter; first, constituted of two parts, the first part presents an introduction to the Aesthetic transcendental of Kant, to show the doctrine of the sensitivity which is part of with its forms space and time, authentic forms of the intuition. The second chapter, is constituted of four parts, that deal with the interpretation of the austere model of Strawson and related with Kant s transcendental Aesthetic. The conclusion of our work, about the declared objection of Strawson in its austere interpretation that refuses the idea of space and time, even keeping its a priori character, cannot be accepted. The apriority, the intuitivity and the ideality are theories non-separable in a coherent boarding of space and time of Kant s model of epistemology

Formatividade e interpretação: a filosofia estética de Luigi Pareyson

The concept of formativity, coined by Luigi Pareyson, is a key to the development of countless contemporary aesthetic studies. The aim of this dissertation is to present a deep understanding of the notion of Formativity and Interpretation, as evidenciated by the title Formativity and Interpretation: the aesthetical philosophy of Luigi Pareyson. The work Aesthetics - Theory of Formativity, first published in 1954, is considered a mark in the rebirth of aesthetics. In this dissertation, the concept of Formativity is examined as a component applicable to every human action, and not limited to pre-determined practices, nor referred to the application of preexisting. I ve performed an investigation of the triple concept of doing-inventing-interpreting, which simultaneously grounds Formativity. In the first section, Pareyson s Aesthetical Propaedeutic is presented; in the second, the Theory of Formativity: the aesthetical character of the whole human experience is analysed; and in the third chapter, The Aesthetical of Form and the Metaphysics of Figuration is related to the formativity character of the knowledge. Through this analysis, I ve intended to evidence how human operability can be understood as search and trial, figuration and invention, in the search for success. In this sense, this thesis seeks to present an interpretation of the idea of work-form, speculating the inexorability of invention and interpretation in an attempt to establish a new bottom line for the studies Pareyson s Aesthetics in Brazil

A ontologia da cor na fenomenologia estética bachelardiana

La philosophie de Gaston Bachelard se fonde sur une tension ontologique, qui comprend tant la Science que la poétique, et au cours de cette recherche, se développe par la compréhension de la possibilité d envisager une ontologie de la couleur, expression de Bachelard ci tée en «Le Droit de Rêver». Nous suivons, donc, face au dialogue ent re la science et la poésie tout en établissant des paramèt res afin d élucider, d un côté, la couleur conceptuelle de la science qui ne matise pas seulement les objets par le biais de l expérience chimico-physique, mais établit aussi dans la relat ion ent re l observateur et l objet une compréhension de l existence de la couleur invisible, celle qui habite l imagination créatrice et apparaît comme un type d ontologie de la couleur. Dans ce sens, la couleur est une image qui naît dans la conscience de l homme, comme un produit direct de l âme dans son actualité même. Ainsi, la couleur serait dans l imagination créative une image autogène desti tuée de substantialité

Aspectos dinâmicos da água versus álcool e acetona por técnicas de congelamento

Water still represents, on its critical properties and phase transitions, a problem of current scientific interest, as a consequence of the countless open questions and of the inadequacy of the existent theoretical models, mainly related to the different solid and liquid phases that this substance possesses. For example, there are 13 known crystalline forms of water, and also amorphous phases. One of them, the amorphous ice of very high density (VHDA), was just recently observed. Other example is the anomalous behavior in the macroscopic density, which presents a maximum at the temperature of 277 K. In order to experimentally investigate the behavior of one of the liquid-solid phase transitions, the anomaly in its density and also the metastability, we used three different cooling techniques and, as comparison systems, we made use of the solvents: acetone and ethyl alcohol. The first studied cooling system employ a Peltier plate, a device recently developed, which makes use of small cubes made up of semiconductors to change heat among two surfaces; the second system is a commercial refrigerator, similar to the residential ones. Finally, the liquid nitrogen technique, which is used to refrigerate the samples in a container, in two ways: a very fast and other one, almost static. In those three systems, three Beckers of aluminum were used (with a volume of 80 ml, each), containing water, alcohol and acetone. They were closed and maintained at atmospheric pressure. Inside of each Becker were installed three thermocouples, disposed along the vertical axis of the Beckers, one close to the inferior surface, other to the medium level and the last one close the superior surface. A system of data acquisition was built via virtual instrumentation using as a central equipment a Data-Acquisition board. The temperature data were collected by the three thermocouples in the three Beckers, simultaneously, in function of freezing time. We will present the behavior of temperature versus freezing time for the three substances. The results show the characterization of the transitions of the liquid

Função de distribuição generalizada aplicada à velocidade de rotação estelar

In the present work we use a Tsallis maximum entropy distribution law to fit the observations of projected rotational velocity measurements of stars in the Pleiades open cluster. This new distribution funtion which generalizes the Ma.xwel1-Boltzmann one is derived from the non-extensivity of the Boltzmann-Gibbs entropy. We also present a oomparison between results from the generalized distribution and the Ma.xwellia.n law, and show that the generalized distribution fits more closely the observational data. In addition, we present a oomparison between the q values of the generalized distribution determined for the V sin i distribution of the main sequence stars (Pleiades) and ones found for the observed distribution of evolved stars (subgiants). We then observe a correlation between the q values and the star evolution stage for a certain range of stel1ar mass

Correlação entre torque, equlíbrio e função do joelho após reconstrução do LCA

Background: Several studies emphasize the importance of assessing the knee function after anterior cruciate ligament (ACL) reconstruction. The influence of several variables on the function of these patients has been analyzed, but there is no consensus in the science literature. Purpose: To evaluate the correlation between the torque and balance on the knee function after ACL reconstruction. Methods: 23 males patients with ACL reconstruction were tested. The procedures of the study included analysis of concentric peak torque at 60o/s and 180o/s of quadriceps femoris and hamstring muscle with a isokinetic dynamometer. The balance in single-limb stance was measured with stabilometry. The functional performance were performed by two hop tests. To estimate the subjective function of the patients was applied Lysholm Knee Scoring Scale and a Global Rating scale. Results: The analysis of data showed a moderate positive correlation between knee extensor torque and functional performance tests (r= 0,48; p=0,02). A moderate negative correlation was found between the two variables of the stabilometry center of pressure and average speed of centre of pressure and the Global Rating scale (r = -0.4, p = 0,04 and r = -0,49, p = 0 ,02, respectively). No correlation was found between peak torque and balance in single-limb stance. Conclusion: The results of the present study suggest that knee extensor strength and postural balance have some influence on knee function in patients after ACL reconstruction

Avaliação da função pulmonar em obesos mórbidos com sonolência diurna excessiva

Background: Obesity impairment to the pulmonary function related to the magnitude of adiposity and is associated with excessive daytime sleepiness (EDS) and snoring, among others symptoms of respiratory disorders related to sleep. It is possible that obese individuals with excessive daytime sleepiness may make changes in lung function on spirometry monitored during the day as a consequence of fragmented sleep or episodes of nocturnal hypoventilation that cause respiratory and changes that can persist throughout the day. The combination of these findings alone sleepiness observed by subjective scales with pulmonary function in obese patients is unknown. Objective: To assess the influence of EDS and snoring on pulmonary function in morbidly obese and distinguish between different anthropometric markers, the snoring and sleepiness which the best predictors of spirometric function and respiratory muscle strength and endurance of these patients. Methods: We evaluated 40 morbidly obese markers on the anthropometric, spirometric respiratory variables, maximal inspiratory and expiratory pressures (MIP and MEP) and maximal voluntary ventilation (MVV) and the measured excessive daytime sleepiness (the Epworth sleepiness scale) and snoring (snoring scale of Stanford). The data were treated when the differences between the groups of obese patients with and without sleepiness, whereas the anthropometric variables, respiratory and snoring. Pearson's correlation was performed, and multiple regression analysis assessed the predictors of pulmonary function. For this we used the software SPSS 15.0 for windows and p <0.05. Results: 39 obese patients were included (28 women), age 36.92+11.97y, body mass index (BMI) 49.3+5.1kg/m², waist-hip ratio (WHR) 0.96+0.07 and neck circumference (NC) 44.1+4.2 cm. Spirometric values and respiratory pressures were up 80% of predicted values, except for endurance (MVV <80%). Obese with EDS have lower tidal volume. Positive correlation was observed between BMI and EDS, EDS and NC and between snoring and BMI, and negative correlation between EDS and tidal volume (TV), and between snoring and snoring FVC and FEV1. In linear regression the best predictor of pulmonary function was snoring, followed by NC. NC has more obese with higher strength (MEP, p = 0.031) and endurance (MVV p = 0.018) respiratory muscle. Conclusion: Obese with EDS tend to have lower TV. In addition, snoring and NC can better predict pulmonary function in obese when compared with other anthropometric markers or EDS. Obese patients with higher NC tend to have greater capacity for overall strength of respiratory muscles, but may have low muscle endurance

Análise da função dos músculos do quadril em portadores de síndrome da dor patelofemural

The Patellofemoral pain syndrome is defined as a fore or retro patellar pain and it has multifactorial etiology, where the bad patellar alignment is the most acceptable hypothesis. However proximal factors to the knee, as the debility of the muscles of the hip, have been demonstrated as a contributing factor to the appearing of that syndrome. Purpose: To evaluate if exists a relation between the hip muscles performance and the development of the SDPF. Methods: Thirty women took part in this study. They were divided in two groups; a control group (fifteen asymptomatic subjects) and an experimental group (fifteen subjects with the diagnosis of SDPF). The muscle performance was evaluated in an isokinetic dynamometer, where it was verified the peak torque (PT), PT to body weight, PT time and the agonist/antagonist relation. It was also analyzed the electromyographic activity of the middle gluteus. The data was analyzed by the not paired t test at a significance level of 5%. Results:. Didn t have significant difference to the PT of the abductor muscles (p = 0,46) and lateral rotators of the hip (p = 0,17) between groups. Also didn t have significant difference to the PT values by the body weight, to these muscle groups either (p = 0,10 e p = 0,11, respectively). Didn t have significant difference between the amplitude of the signal (p = 0,05) and the onset of medium gluteus (p = 0,25) between the groups. Conclusion: In the experimental conditions realized, the study didn t demonstrate a relation between performance the hip muscles behavior and the development of the SDPF