Estudo da oxidação superficial de ligas odontológicas de Ni-Cr em plasma pulsado para uso em restaurações metalocerâmicas

Metal ceramic restorations matches aesthetic and strength, and in your making occurs an interface oxide layer, wetting resulting and atomic and ionic interactions resulting between metal, oxide and porcelain. However, frequent clinical fails occurs in this restoration type, because lost homogeneous deposition oxide layer and lost interface bond. Thus, in this study, thought depositate homogeneous oxide films above Ni-Cr samples surfaces polite previously, at plasma oxide environment. Six samples was oxided at 300 and 400ºC at one hour, and two samples was oxided in a comum chamber at 900ºC, and then were characterized: optical microscopic, electronic microscopic, micro hardness, and X ray difratometry. Colors stripes were observed at six samples plasma oxided and a grey surface those comum oxided, thus like: hardness increase, and several oxides from basic metals (Ni-Cr)

Fresamento com ar quente: uma proposta para minimizar a formação de trincas térmicas em ferramentas de metal duro

This work presents the results, analyses and conclusions about a study carried out with objective of minimizing the thermal cracks formation on cemented carbide inserts during face milling. The main focus of investigation was based on the observation that milling process is an interrupted machining process, which imposes cyclic thermal loads to the cutting tool, causing frequent stresses changes in its superficial and sub-superficial layers. These characteristics cause the formation of perpendicular cracks from cutting edge which aid the cutting tool wear, reducing its life. Several works on this subject emphasizing the thermal cyclic behavior imposed by the milling process as the main responsible for thermal cracks formation have been published. In these cases, the phenomenon appears as a consequence of the difference in temperature experienced by the cutting tool with each rotation of the cutter, usually defined as the difference between the temperatures in the cutting tool wedge at the end of the cutting and idle periods (T factor). Thus, a technique to minimize this cyclic behavior with objective of transforming the milling in an almost-continuous process in terms of temperature was proposed. In this case, a hot air stream was applied into the idle period, during the machining process. This procedure aimed to minimize the T factor. This technique was applied using three values of temperature from the hot air stream (100, 350 e 580 oC) with no cutting fluid (dry condition) and with cutting fluid mist (wet condition) using the hot air stream at 580oC. Besides, trials at room temperature were carried out. Afterwards the inserts were analyzed using a scanning electron microscope, where the quantity of thermal cracks generated in each condition, the wear and others damages was analyzed. In a general way, it was found that the heating of the idle period was positive for reducing the number of thermal cracks during face milling with cemented carbide inserts. Further, the cutting fluid mist application was effective in reducing the wear of the cutting tools.

Formação de particulas submicrometricas de pmma por cristalização termica de solução polimérica

Polymer particles in the nanometer range are of fundamental interest today, especially when used as carrier systems in the controlled release of drugs, cosmetics and nutraceuticals, as well as in coating materials with magnetic properties. The main objective of the present study concerns the production of submicron particles of poly (methyl methacrylate) (PMMA) by crystallization of a polymer solution by thermally controlled cooling. In this work, PMMA solutions in ethanol and 1-propanol were prepared at different concentrations (1% to 5% by weight) and crystallized at different cooling rates (0.2 to 0.8 ° C / min) controlled linearly. Analysis of particle size distribution (DLS / CILAS) and scanning electron microscopy (SEM) were performed in order to evaluate the morphological characteristics of the produced particles. The results demonstrated that it is possible to obtain submicron polymer perfectly spherical particles using the technique discussed in this study. It was also observed that, depending on the cooling rate and the concentration of the polymer solution, it is possible to achieve high yield in the formation of submicron particles. In addition, preliminary tests were performed in order to verify the ability of this technique to form particulated carrier material with magnetic properties. The results showed that the developed technique can be an interesting alternative to obtain polymer particles with magnetic properties

Aspectos gerais da formação de professores

Este artigo, ancorado em estudos recentes e antigos, mostra o afastamento dos cursos de formação de professores em relação aos elementos que compõem a prática profissional docente. Favorável a uma aproximação efetiva com o contexto das práticas de sala de aula, o autor defende a idéia de uma formação de professores atrelada aos problemas e necessidades da prática docente no ensino formal de 1º e 2º graus.

O ambiente virtual na formação inicial de professores de alemão como apoio para o ensino e a aprendizagem da língua e a reflexão sobre ações docentes

Estudiosos dos campos da Educação, da Linguística Aplicada e da Formação de Professores de Línguas insistem hoje na grande importância da inclusão de Tecnologias de Informação e Comunicação (TICs) na formação inicial, bem como na necessidade de promover o desenvolvimento do pensamento crítico-reflexivo dos futuros professores. Tomando como pressupostos teóricos estudos acerca das características da sociedade de informação, dos ambientes virtuais e da formação de professores, este trabalho tem como objetivo discutir possibilidades oferecidas pela plataforma Moodle de aprendizagem na formação inicial de professores de alemão. Para tanto, apresentaremos diferentes formas de uso de ambientes virtuais e de ferramentas neles disponíveis, que demonstraram ser de grande valor no processo de formação de licenciandos, tanto em língua alemã, quanto durante suas práticas iniciais. As experiências apontam para um valor inestimável de ambientes virtuais no acompanhamento de licenciandos no processo de aprendizagem da língua e nas primeiras experiências com a docência.

Opiniões sobre estágio curricular e prática de ensino na licenciatura em química: o caso do CEFET-PB

The Brazilian legal documents are directing the reformulation of the courses that prepare students to be teachers. Through out the country many institutions look for to fit themselves in such documents. On the other hand, other IES (Superior Education Institutions), when they are setting up such courses they looked for to be adequate to the new public politics. Based on the National Curricular Norms to form teachers for Basic Education, in tertiary level, in 2004 it was created at the CEFET-PB,the Chemistry Course (Licenciatura) to prepare people to be teachers, whose organization. This work presents the results of a research of phenomenological nature that aimed to comprehend the teachers opinions, in the range of discussions about the current politics of formation, particularly related to the CNE/CP 1 and CNE/CP 2/2002 resolutions. This work based on the curricular proposal for the Chemistry Course (Licenciatura), presents the relationship between the probationary period and the teaching practice at the CEFET-PB, in order to contribute for a reflection about these categories to clarify the teachers of the course. It started from the consideration of all changes operated in contemporary society implies changes on teacher's pedagogical practices. It was used tow instruments for the data collection: a questionnaire with open and closed questions and recordable interviews. Nine teachers form the CEFET-PB took apart and four licensed teachers. It was based in a theoretic frame as a support for discussions about the different models of teachers formation. We concluded that the representations of teachers about probationary period the practice on the activity for the teachers formation was strongly anchored in characteristic elements of the formative tendency of a institution that historically acted on a technician formation, and the results pointed to strong signs of attitudes based on a model of the technical rationality

A Esquizoanálise e a produção da subjetividade: considerações práticas e teóricas

O presente artigo discute algumas questões relativas à produção da subjetividade a partir do referencial esquizoanalítico de Deleuze e Guattari. Optamos por discorrer sobre o assunto procurando não nos prendermos, na medida do possível, em conceitos e jargões técnicos. Iniciamos com uma parte mais teórica, na qual colocamos em tela algumas das idéias centrais da Esquizoanálise e sua perspectiva de formação da subjetividade, que entendemos como sendo a argamassa de constituição do mundo, abrindo caminho para uma parte mais prática, na qual analisamos o conto O Espelho, de Machado de Assis, de acordo com a ética estética de valorização da vida que entendemos ser a Esquizoanálise.

Estudo psicossocial de um seminário teológico: a formação do clero católico em análise

Este artigo apresenta dados preliminares e discussões de uma investigação em psicologia social sobre a produção da subjetividade eclesiástica. Utilizando o instrumental teórico da análise institucional, estudamos o dispositivo pedagógico seminário. Nosso campo de pesquisa é um seminário católico de teologia, onde vivem 50 seminaristas em regime de internato, na etapa final de preparação para o sacerdócio, os quais, uma vez ordenados, passarão a ocupar posições de relevância que consistem na coordenação de comunidades paroquiais amplas. Os dados foram obtidos por meio da observação do cotidiano institucional. Apresentamos algumas conclusões preliminares. Encontramos fortes contradições entre os discursos oficiais e as práticas cotidianas no seminário teológico.

Um estudo de práticas matemáticas históricas e sugestões de uso na matemática escolar

This dissertation aims to contribute on teaching of mathematics for enabling learning connected to the relationship among science, society, culture and cognition. To this end, we propose the involvement of our students with social practices found in history, since. Our intention is to create opportunities for school practices that these mathematical arising from professional practice historical, provide strategies for mathematical thinking and reasoning in the search for solutions to problematizations found today. We believe that the propose of producing Basic Problematization Units, or simply UBPs, in math teacher formation, points to an alternative that allows better utilization of the teaching and learning process of mathematics. The proposal has the aim of primary education to be, really forming the citizen, making it critical and society transformative agent. In this sense, we present some recommendations for exploration and use of these units for teachers to use the material investigated by us, in order to complement their teaching work in mathematics lessons. Our teaching recommendations materialized as a product of exploration on the book, Instrumentos nuevos de geometria muy necessários para medir distancia y alturas sem que interuengan numeros como se demuestra em la practica , written by Andrés de Cespedes, published in Madrid, Spain, in 1606. From these problematizations and the mathematics involved in their solutions, some guidelines for didactic use of the book are presented, so that the teacher can rework such problematizations supported on current issues, and thus use them in the classroom

Inscrição discursiva da subjetividade homoafetiva na G Magazine

This thesis, which is entitled Registration discourse of subjectivity homo affective in G Magazine, is proposed to describe / interpret modes of subjectivity that is set in the discourse of homo affective confessions, recorded in letters addressed to G Magazine. The study is based on the theories of Discourse Analysis French, with a focus in the discussions Foucaultian remarkably discursive practices that produce meanings about the processes of subjectivity and sexuality. Methodologically, the research is of appreciative/qualitative character and falls in the field of Applied Linguistics (LA), at a press that the historical and cultural reality of the subject, establishing dialogues with many other fields of knowledge, which deal of the subject matter of speech and sexuality. Data analysis indicates that the magazine G Magazine works as a discursive space, where individuals on condition that homosexual, take it as the place that it gives security to talk to you, it's worrying, because the nature of the journal it suggests a belonging to the same discursive formation - that of homo affective . Thus, some of which are felt constructed for the investigation of the letters selected for this study showed that the forms of subjectivity of such homo affective are emerging in the game of the bans, the other is that as a subject of sexuality and to materialize in operation the confession. These homo affective, in a gesture of incessant registration of alternatives to be subject to its own truth of their sexuality, to seek his party in the case, the psychologist, a referral, a "light" that can guide them in an attempt to get rid of the forms of to subject. Installs itself in this way, as a point of resistance: the attempt to dissociate itself be of some states of submission, opening itself to other ways of being subject

O leitor universitário e a construção das práticas de ler e escrever textos impressos e digitais

The construction of a mapping of the practices of reading and writing printed and digital texts, declared by graduating students from the Bachelor s degree in Science and Technology (BCT), has provided us the analysis of the course they are making in such a socio-historical moment characterized by the revolution of the post-paper. In this sense, the general objective of this research is to understand how that construction works under the point of view of those graduating students. For this, our reflection has been guided by the search of answers for some questions which have presented to us: what reading and writing conceptions BCT graduating students have; what reading and writing practices those collaborators develop; what collections they declare to have access to; what differences they declare to have between printed and digital reading and writing along the different social roles they develop; what the reader/writer identity relations of those collaborators are. To achieving the plausible answers, we have gathered a corpus composed by texts of three genres of the argument order: academic profiles (or self-portrait), opinion articles and argumentative letters. Besides, we have made semi-structured interviews and questionnaires in the online tool of the Google Docs. The methodology which supports this academic work is the qualitative research (SIGNORINI; CAVALCANTI, 1998)of ethnographic direction (THOMAS, 1993; ANDRÉ, 1995) in Applied Linguistics (CELANI, 2000; MOITA-LOPES, 2006) and the theoretical contribution comes from the bakhtinian perspective of language conception (BAKHTIN [1929] 1981); the socio-historical writing construction (LÉVY, 1996; CHARTIER, R., 1998, 2002, 2007; COSCARELLI, 2006; CHARTIER, A., 2007; ARAÚJO, 2007; COSCARELLI; RIBEIRO, 2007; XAVIER, 2009; MARCUSCHI; XAVIER, 2010); from the studies of the pedagogy of the writing (GIROUX, 1997); from the literacy studies understood as sociocultural practice, plural and situated (TFOUNI, 1988; KLEIMAN, 1995; TINOCO, 2003, 2008; OLIVEIRA; KLEIMAN, 2008), from the studies about identity in postmodernity (HALL, 2003; BAUMAN, 2005). The results of the analysis have pointed at a multiplicity of reading/writing practices of printed and digital texts developed by the BCT graduating students due to the coexistence of the modality printed and that one derived from the new mobile devices. In that multiplicity, the prevalent idea of the collaborators is that there is a continuum between printed texts and digital texts (not a dichotomy), since the option of reading/writing printed texts or digital ones is always linked to specific communication situations, which involve participants, objectives, strategies, values, (dis)advantages, besides (re)creation of discursive genres in function of the mobile devices to which those collaborators have access in the different spheres of activities that they participate. All of that has caused a deep intersection in the identity traces of college students readers/writers in the 21st century which cannot be ignored by academic formation

Eensino de língua portuguesa: da formação do professor à sala de aula

La reflexión crítica sobre la escuela y los quehaceres docentes ha favorecido la producción y la sistematización de nuevos saberes basados en fundamentos científicos, principalmente sobre las prácticas pedagógicas. En la enseñanza de Lengua Portuguesa, las investigaciones buscan comprender lo qué y cómo se enseña y se aprende durante la escolarización. En esa perspectiva, realizamos un estudio sobre la formación del profesor de Lengua Portuguesa y sus implicaciones en la clase, buscando observar la actuación de los alumnos-maestros en el contexto escolar, durante la realización de las Prácticas. Para tanto, elegimos como objetivo general, investigar cómo la carrera de Filología de la UFRN/CERES/Campus de Currais Novos promovía la formación de futuros profesores para atender a las expectativas de las políticas públicas para la enseñanza de Lengua Materna. Como referencial teórico, estudiamos los PCN, el proyecto político pedagógico de la carrera y autores del área de enseñanza de Lengua Portuguesa y de Educación, entre ellos, Geraldi (1996), Travaglia (1996, 2003), Antunes (2003, 2007, 2009 y 2010), Lomas (2003), Figueiredo (2005), Marcuschi (2001, 2008), Oliveira (2010), Riolfi et al. (2008), Possenti (2003), Alarcão (1996, 2001) Imbernón (2011), Pimenta y Lima (2010) y Schön (1993). El estudio está situado en el ámbito de la Lingüística Aplicada y se caracteriza como investigación cualitativa de naturaleza interpretativista, a partir de un abordaje de inspiración etnográfica del ambiente de las Prácticas. En los resultados constatamos que los alumnos-maestros privilegian la enseñanza prescriptiva, fundamentado en una concepción de lengua como sistema, direccionando la enseñanza de la lengua para la dirección contraria al abordaje funcionalista (lengua / uso), distanciándose considerablemente de la propuesta de formar un alumno crítico y agente de transformación. Respecto a la visión de los alumnos-maestros sobre la carrera, fueron listadas algunas cuestiones relevantes, entre ellas, los contenidos que hacen parte de la carrera, la distribución de la carga horaria de los componentes curriculares, la revisión de las ementas, la oferta de asignaturas de inclusión social, la reorganización de las actividades de la práctica en relación al acompañamiento y orientación a los alumnos-maestros y, especialmente, la desarticulación teoría / práctica que fue considerada como responsable por muchas de las dificultades encontradas por los referidos alumnos en la fase de regencia de clase en la enseñanza de Lengua Portuguesa en los niveles de enseñanza fundamental y media. De ese modo, a partir del análisis de estos significados construidos por los alumnos-maestros sobre el proceso de formación en esa carrera de Letras, constatamos la necesidad de una revisión del proyecto de la carrera, pues éste presenta esas fragilidades que necesitan ser analizadas en función de la mejoría de la calidad de la enseñanza de la graduación

As práticas exitosas de leitura no ensino fundamental: vozes sociais de professores e de estudantes

The school is the social place which should provide the formation of critical readers. In this context, the role of the teacher is crucial when it comes to teaching reading. Thus, this doctoral research aims to explicit the reading practices evidenced from social voices of teachers and Fundamental School students from state public schools at RN that have successful results, according to IDEB 2009. Moreover, we seek to explicit, through the positions of teachers, the conceptions of reading underlying their reading activities, as well as elucidate the social voices related to teaching of reading that are present in the National Curriculum Guide for 9 years Fundamental School and in the Political-Pedagogical Projects of the educational institutions investigated. In order to accomplish this goal, we carried out observations in the classroom, applied questionnaires with teachers and students in the 9th grade of Fundamental School, in classes of Portuguese Language, and also performed dialogical meetings with the management and pedagogics schools teams. The theoretical foundation that guides the research comes from bakhtinian thinking (2009, 2010), which addresses the dialogical perspective of language and active responsive comprehension. Furthermore, this work is anchored in theoretical reflections of Antunes (2005, 2009) and Geraldi (2003, 2006, 2010) about the reading and writing in the country, which contribute to the resizing of the teaching and learning process of Portuguese Language. This study belongs to the field of Applied Linguistics, which investigates language as social practice in the context of learning mother language or in contexts where relevant questions about the use of language are evidenced. The parameters of qualitative research in a social-historic perspective are adopted seeking to understand the school context by the subjects involved in research. The research corpus is composed of: (i) information constructed through the use of questionnaires with teachers and students; (ii) information constructed from the observed lesson and dialogue with management and pedagogical teams; (iii) a set of selected information, i.e., empiricism built through documentary analysis of the National Curriculum Guide for 9 years Fundamental School (CONSELHO NACIONAL DE EDUCAÇÃO, 2010) and the Political- Pedagogical Projects of the investigated schools. The analysis of the sayings of teachers and students suggest reading practices from various texts, in particular, from the literary sphere, in activities involving discussions, reading and reading comprehension exercises, interviews, songs, seminars organizations, concerts, dramatizations, literary weeks, among other practices. Furthermore, these analyses reveal that teach Portuguese Language requires commitment, responsibility and satisfaction, as well as more grounded theoretical principles, which make teaching practice more efficient. The research also reveals that the success of the teaching-learning process occurs by virtue of the involvement of school s segments in the educational process, creating therefore a network of responsibilities. In this sense, this research may contribute to the production of knowledge that can guide and enrich the teaching and learning of reading, envisioning a pedagogical practice constructed from the relationship with the other, i.e., from the dialogism which provides formation of young people that exercise their citizenship

Das estantes para a tela: práticas de leitores de livros impressos e digitais do curso de Comunicação Social da Universidade Federal do Rio Grande do Norte

La cultura del libro impreso impregna la vida cotidiana de los lectores durante más de cinco siglos, y de esto, hábitos y significados a cerca del libro como medio de comunicación tienen sus raíces en la comunidad lectora, en una especie de contrato de lectura (VERÓN, 2004). Por lo tanto, creemos que es posible conjeturar que la aparición del libro digital puede cambiar las viejas prácticas en relación con el libro impreso y por eso mismo deben ser investigadas con el fin de entender este tiempo de productos reconfigurados. Consciente de ello, el tema central de nuestra investigación se basa en la comprensión de cómo los lectores de libros digitales realizan sus prácticas. Nuestro objetivo general es investigar las prácticas socioculturales de los lectores de libros digitales, con el fin de mostrar las continuidades y discontinuidades en el uso del libro en su formato impreso y digital. Con este fin, se busca 1) proponer una caracterización de la cultura del libro impreso, que es el apoyo a una asignación posible de las marcas de una cultura del libro digital, y 2) explorar los lugares de producción y oferta de los libros digitales, especialmente en Brasil, fin de delimitar en su primera configuración. Apoyamos, como propuesta metodológica, la sistematización de dimensiones culturales del libro impreso llamadas: ritualidad, simbología, materialidad y forma, lo que ayudará el enfoque del empírico. Nuestra propuesta se basa, en varios puntos, en los investigadores de la historia del libro, insertada en el campo de la Historia Cultural (BURKE, 2008; CHARTIER, 1992, 1994, 2006; DARNTON, 1990, 2006, 2010). Adoptamos como técnica de investigación el análisis de voces, registradas a través de entrevistas en profundidad, de lectores de libros en formato digital. Antes de eso, creemos apropiado emprender un estudio exploratorio basado en la aplicación de un cuestionario online. Nuestra delimitación incluye lectores de libros digitales del curso de Comunicación Social de la Universidad Federal de Rio Grande do Norte. Entre las conclusiones de esta disertación, es posible señalar que el grupo de lectores investigados está sólidamente ligado a las experiencias con los libros impresos y esto afecta en gran medida las prácticas de los libros digitales

Apropriação de novas mídias por estudantes universitárias

It is an investigation that seeks to reveal, record and analyze the process of appropriation and use of digital media by university students, aged between 40 and 60 years. Interested in studying how changes are perceived in the educational sphere for students Whois have gone through liberal/traditional school, ie, effected the first contact with technological devices media as adults, in the university. This investigation sought to contribute to the knowledge on the use of new learning strategies imposed by digital media by recording and analyzing the reports surveyed sample. Allowed to know the cultural universe of these women, revealing the context in which receive mediated messages and uses that maré these learning strategies within their daily academic life. Gathered in this work, reflexions guided by studies of media reception and role played by digital media as builders images and facilitators in knowledging acquisitions, it was chosen to work two main theorical notions: communication media and digital inclusion. As the research methodology, it was used the exploratory descriptive technical together with other appropriate tecniques. In ordem to approach the problem can be observed two phases: a quantitative one, which was used an investigative procedure, a survey data with closed questions; and a qualitative phase, which was used to collect data through a diary from situations encountered in the classroom. The main objective of analyzing how digital media are received, appropriated and used by university women has been fulfilled and it is remarkable that they access with dificulty and can not be considered included digitally. The results show that the problem of these agents is not the access, there are was of appropriation of digital media offered at IES, and it was possible to note that they seek to integrate to the technological world, and they even have devices that can insert them on this world. Insertion in cyberculture sets up the ability to find a favorable way to be aware of reality and production of knowledge and liberating and dignifying practices, in this case refers to an appropriation of citizenship through the field of technological devices offered as a perspective that they can interact