CIDADANIA DIGITAL: Um estudo do programa brasileiro para a sociedade da informação

A pesquisa analisa o Livro Verde, publicado em 2000 pelo Ministério da Ciência e Tecnologia, buscando compreender as ações do Estado na introdução do país na sociedade da informação . O estudo enfoca as iniciativas de inclusão digital estatais e não-governamentais e sua relação com a ampliação da cidadania. A pesquisa faz uso do método documental e da abordagem histórico-crítica para interpretar a ação dos atores públicos e privados na formulação das políticas públicas que definem os objetivos estratégicos e as metas do Brasil para a área das tecnologias da informação e comunicação (TIC).

A CIÊNCIA NO PICADEIRO: UMA ANÁLISE DAS REPORTAGENS SOBRE CIÊNCIA NO PROGRAMA FANTÁSTICO

Esse trabalho visa elaborar uma análise crítica do discurso sobre ciência presente no programa Fantástico de televisão. Dentro da perspectiva da análise crítica do discurso, busca-se encontrar marcas que indiquem a intencionalidade do discurso, tanto de cientistas como de comunicadores, bem como discrepâncias entre a intenção e a comunicação efetivamente realizada, na medida em que todo ato comunicativo é permeado também pelas condições em que foram gerados e recebidos. Dentro desse marco, o trabalho identifica o programa como enunciador de um discurso que se tece a partir das múltiplas vozes que contribuem para sua a realização. A partir da identificação desse papel, a análise se volta para as características da informação científica nele presente.

A INFLUÊNCIA DAS PRÁTICAS PEDAGÓGICAS DOCENTES E DAS BARREIRAS DISCENTES SOBRE O DESENVOLVIMENTO DA CRIATIVIDADE DO FUTURO ADMINISTRADOR

As empresas que almejam garantir e melhorar sua posição dentro de em um mercado cada vez mais competitivo precisam estar sempre atualizadas e em constante evolução. Na busca contínua por essa evolução, investem em projetos de Pesquisa & Desenvolvimento (P&D) e em seu capital humano para promover a criatividade e a inovação organizacional. As pessoas têm papel fundamental no desenvolvimento da inovação, mas para que isso possa florescer de forma constante é preciso comprometimento e criatividade para a geração de ideias. Criatividade é pensar o novo; inovação é fazer acontecer. Porém, encontrar pessoas com essas qualidades nem sempre é tarefa fácil e muitas vezes é preciso estimular essas habilidades e características para que se tornem efetivamente criativas. Os cursos de graduação podem ser uma importante ferramenta para trabalhar esses aspectos, características e habilidades, usando métodos e práticas de ensino que auxiliem no desenvolvimento da criatividade, pois o ambiente ensino-aprendizagem pesa significativamente na formação das pessoas. O objetivo deste estudo é de identificar quais fatores têm maior influência sobre o desenvolvimento da criatividade em um curso de graduação em administração, analisando a influência das práticas pedagógicas dos docentes e as barreiras internas dos discentes. O referencial teórico se baseia principalmente nos trabalhos de Alencar, Fleith, Torrance e Wechsler. A pesquisa transversal de abordagem quantitativa teve como público-alvo os alunos do curso de Administração de uma universidade confessional da Grande São Paulo, que responderam 465 questionários compostos de três escalas. Para as práticas docentes foi adaptada a escala de Práticas Docentes em relação à Criatividade. Para as barreiras internas foi adaptada a escala de Barreiras da Criatividade Pessoal. Para a análise da percepção do desenvolvimento da criatividade foi construída e validada uma escala baseada no referencial de características de uma pessoa criativa. As análises estatísticas descritivas e fatoriais exploratórias foram realizadas no software Statistical Package for the Social Sciences (SPSS), enquanto as análises fatoriais confirmatórias e a mensuração da influência das práticas pedagógicas e das barreiras internas sobre a percepção do desenvolvimento da criatividade foram realizadas por modelagem de equação estrutural utilizando o algoritmo Partial Least Squares (PLS), no software Smart PLS 2.0. Os resultados apontaram que as práticas pedagógicas e as barreiras internas dos discentes explicam 40% da percepção de desenvolvimento da criatividade, sendo as práticas pedagógicas que exercem maior influencia. A pesquisa também apontou que o tipo de temática e o período em que o aluno está cursando não têm influência sobre nenhum dos três construtos, somente o professor influencia as práticas pedagógicas.

ANALISANDO A RELAÇÃO DOS VOLUMES DE EXPORTAÇÃO E DE IMPORTAÇÃO, PIB, TAXAS DE CÂMBIO E INFLAÇÃO NO PERÍODO DE 2004 A 2014. SÃO BERNARDO DO CAMPO 2015

As empresas que almejam garantir e melhorar sua posição dentro de em um mercado cada vez mais competitivo precisam estar sempre atualizadas e em constante evolução. Na busca contínua por essa evolução, investem em projetos de Pesquisa & Desenvolvimento (P&D) e em seu capital humano para promover a criatividade e a inovação organizacional. As pessoas têm papel fundamental no desenvolvimento da inovação, mas para que isso possa florescer de forma constante é preciso comprometimento e criatividade para a geração de ideias. Criatividade é pensar o novo; inovação é fazer acontecer. Porém, encontrar pessoas com essas qualidades nem sempre é tarefa fácil e muitas vezes é preciso estimular essas habilidades e características para que se tornem efetivamente criativas. Os cursos de graduação podem ser uma importante ferramenta para trabalhar esses aspectos, características e habilidades, usando métodos e práticas de ensino que auxiliem no desenvolvimento da criatividade, pois o ambiente ensino-aprendizagem pesa significativamente na formação das pessoas. O objetivo deste estudo é de identificar quais fatores têm maior influência sobre o desenvolvimento da criatividade em um curso de graduação em administração, analisando a influência das práticas pedagógicas dos docentes e as barreiras internas dos discentes. O referencial teórico se baseia principalmente nos trabalhos de Alencar, Fleith, Torrance e Wechsler. A pesquisa transversal de abordagem quantitativa teve como público-alvo os alunos do curso de Administração de uma universidade confessional da Grande São Paulo, que responderam 465 questionários compostos de três escalas. Para as práticas docentes foi adaptada a escala de Práticas Docentes em relação à Criatividade. Para as barreiras internas foi adaptada a escala de Barreiras da Criatividade Pessoal. Para a análise da percepção do desenvolvimento da criatividade foi construída e validada uma escala baseada no referencial de características de uma pessoa criativa. As análises estatísticas descritivas e fatoriais exploratórias foram realizadas no software Statistical Package for the Social Sciences (SPSS), enquanto as análises fatoriais confirmatórias e a mensuração da influência das práticas pedagógicas e das barreiras internas sobre a percepção do desenvolvimento da criatividade foram realizadas por modelagem de equação estrutural utilizando o algoritmo Partial Least Squares (PLS), no software Smart PLS 2.0. Os resultados apontaram que as práticas pedagógicas e as barreiras internas dos discentes explicam 40% da percepção de desenvolvimento da criatividade, sendo as práticas pedagógicas que exercem maior influencia. A pesquisa também apontou que o tipo de temática e o período em que o aluno está cursando não têm influência sobre nenhum dos três construtos, somente o professor influencia as práticas pedagógicas.

Proposta arquitetônica para o Centro de Treinamento dos Servidores do IFRN com base nos fatores de desempenho energético.

In recent years, as part of the expansion process of its activities, the Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte – IFRN (Federal Institute for Education, Science and Technology of the State of Rio Grande do Norte – IFRN) detected the need to hire more employees for the institution. This expansion process, a policy of the Federal Government, together with the increase of human resources, required the construction of an adequate facility in the municipality of São Gonçalo do Amarante-RN, for training and qualification and as a means of better enabling its personnel. Along with this policy, the Federal Government is also deeply concerned that its buildings be environmentally friendly. This study deals with this subject matter, as it develops an architectural design of a public building with an emphasis upon the reduction of energy consumption, through the study of energy performance factors such as defined by Carneiro (1988) and adapted by the author of the present study. It is known that residential, commercial and public buildings represent about 45 % of energy consumption in Brazil. That is why it is necessary to consider the reduction of such consumption in buildings, as well as the role that professionals, especially architects, play in this issue. The most effective participation in this regard in the field of architecture occurs in the design phase. However, the architectural solution proposed here goes beyond the energy performance factors, since it also involves other aspects, such as the definition of the concept, the parti and the spatial solution itself. In this sense, the architectural project of the Centro de Treinamento dos Servidores do IFRN - CTSIFRN (Training Center for IFRN Personnel – CTSFIRN) is particularly fitting as a subject for research at the Professional Master Program at PPGAU/UFRN, which is devoted to research on architecture, design and the environment.

Uma abordagem crítica do conteúdo esporte nas aulas de educação física no ensino médio integrado

Researchers have analyzed how sport is being taught in the classroom as a regular subject and how it is accepted as a pedagogical action at school. This study aims to suggest some pedagogic proposal on the Physical Education subject to High School System which would be planned, formulated, and applied based on some critical approach on teaching, as well as analyzing and thinking over its impact on the students' learning, taking in consideration some conceptual, procedural and attitudinal dimensions to make possible for the students to become more critical so that they will understand how this subject works in contemporary time. .We had three specific blocs to develop our research: Historic, conceptual and cultural elements about sport; Public policies to sport; Individual, group and environmental characteristics. The method of this work was based on qualitative research through some research action. The study was made actually at IFRN (Federal Institute of Education, Science and Technology of Rio Grande do Norte state), in the city of Pau dos Ferros. Students from the second year of the computing course in high school were the participants in the research, there were 37 students from eleven different cities near Pau dos Ferros. They answered some questionares and a Research Diary. From the pedagogical intervention we could prove the students have improved their knowledge about the concept on sport itself, leaving the old idea about sport only as a physical practice such as an activity with rules or as competition, we could prove they have sport as a social-cultural event, involving policies, ideologies as well as historical interferences. Another aspect they mentioned was that sport is the citizens' right and as such there must be public policies pro sports. Understanding that sport transpires on peoples' habits as well as their behavior allowed us to identify its influence on our students' quality of life back in their home towns. Therewith, it is clear the necessity of a pedagogical focus on the content of Physical Education at school to make this subject more meaningful, so that the students will become more critical and reflexive about life and will be able be real citizens

Concepções de formação profissional técnica de nível médio adotadas pelo IFRN: especificidades e (des)continuidades

The thesis deals with the concepts of technical tra ining of middle level adopted by the Federal Institute of Education, Science and Technology of R io Grande do Norte (IFRN). Discusses these concepts from the four political-pedagogical projects built in the period 1970 to 2010, spanning three institutionalities: Federal Technica l School of Rio Grande do Norte (1970- 1998), Federal Center of Technological Education of Rio Grande do Norte (1999-2008) and IFRN (from 2008) as well as three important politic al contexts of the country: Civil-Military Dictatorship, New Republic and Period of neoliberal ideas in Brazil. The goal is to analyze the configuration of the conceptions of training adopte d in the political-pedagogical projects IFRN, with emphasis on the specificities and (dis) contin uities, placing them in the context of political, economic and educational change in development in t he country. Addresses the relationship work, education and human development in capitalist society, in order to grasp the concept of employee training engendered by that company as wel l as the possibility of a counter- hegemonic formation. We analyze the formation of mi d-level concepts outlined in the educational reforms implemented in the country. We investigate the concepts of training outlined in the political-pedagogical projects IFRN . Makes use of the historical-dialectical materialism, the literature review, the documentary research and interviews were conducted with subjects who participated in the working group coordinator of the drafting of the political- institutional educational projects. The results sho w that the training of workers in capitalist society has a unilateral character; that the traini ng required by the working class is the omnilateral training; that the formative ideas that permeated the educational reforms in the country between 1970 and 2010 were all envisaged by unilateral training; that, in certain contexts, conceptions of technical training medium level outlined in the political-pedagogical projects IFRN reflect the formative perspectives th at guide educational reforms in the country (unilateral training) and, at other times, the inst itution adopts concepts (training omnilateral) that are not consistent with such prospects; and th at between the political-pedagogical projects built from 1970 to 2010 there are more continuities than breaks in relation to the concepts of training adopted. We conclude that the challenge is to institutionalize the IFRN their educational actions omnilateral designing training undertaken in the political-pedagogical project 2009.

Uma análise da formação de professores de física do IFRN a partir da epistemologia de Ludwik Fleck

This study arises in the context of physics teacher training and aims, from the speech of the teacher trainer, identify possible pedagogical models and characterize thinking styles present in the course of licentiate in physics of IFRN using the epistemology of Ludwik Fleck. We classify our research as qualitative with an empirical nature, and for the analysis we chose the discursive textual analysis - DTA (MORAES, 2003). The locus of our research will be the licentiate in physics at the Federal Institute of Education, Science and Technology of Rio Grande do Norte - IFRN, Natal-Central Campus and the research subjects, a group of teacher trainers of this course. We interviewed ten teachers, being six from the group dedicated to physics and four from the group dedicated to didactics and pedagogy. From this design, we performed data acquisition consisted of: 1) semi-structured interview, 2) document analysis. On the data analysis, with the support of pedagogical trends that were observed in our study based on the perception of the similarities and differences between the ideas presented by teachers about: education and teaching; ideal teaching practice, teacher's role, learning conceptions, and according to the student and on the ideological thinking of these former teachers on the professional profile of graduates, we noted subsidies to identify evidences of the presence of three distinct thinking styles that interrelate with each other in a considerably intense way. The relevance of the study is presented in the understanding of thinking styles that participate in the dynamics of the course of teacher training in physics, and by consequence, elucidation of a problem pointed out a priori as motivating the research: the difficulty of communicative interaction on educational practices among teacher trainers. We bring Fleck's epistemology as a motivating possibility of dialogue and negotiation, setting thus an instrument of real change, towards the significance of teacher training in physics.

Mediação biográfica: propostas para a formação docente

This work aims at studying the biographical mediation taken as the progress of people in formation process who develop a biographical work on their own experiences with the help of a former (PASSEGGI, 2006, 2011). The research was carried out on a curricular component from Curso de Formação Inicial e Continuada (initial and continuous process of formation of teachers) with teachers from public schools developed by Instituto Federal de Educação do Rio Grande do Norte (IFRN/ Ipanguaçu). The target audience featured diversity of professionals and experiences of formation. The general objective studied the potentials of procedures and devices used to mediate the reflection about the necessary knowledge to teaching practice based on their own experiences (auto-biographical) and the experience from the others (hetero-biographical). The study tried to respond to the following questions: how do teachers in formation relate themselves to the knowledge from experience? What procedures and devices contribute on the teachers‟ formation on the three different dimensions of biographical mediation (initiatory, maieutic, hermeneutics)? How to provide the auto-formation and hetero-formation? The theories and methods of this work are based on studies and researches that place the person in formation in the center of investigation and formation and analyze their reflective, re-inventive and self-re-inventive capacity. (FREIRE, 1987, 1996, 2001, 2011; JOSSO, 2008, 2010, 2012; DELORY-MONBERGER, 2006, 2008, 2012; CHARLLOT, 2000; CATANI, 2001; PASSEGGI, 2008; 2010; 2011; 2012). We selected six teachers who participate entirely on the meetings of the program. They discussed on the study topics, shared narrations that integrate their formation and the themes related to the course. The empirical material is composed by the narrations of the six participants and hearing boards done by themselves at the moment of the narration sharing process. The analysis followed three steps: a) the path of the program and the procedures of biographical mediation; b) the relations former/teacher on the three dimensions of biographical mediation; c) the hearing board as a device of biographical mediation. We concluded that the procedures and devices used for biographical mediation made possible specific learnings that are sources for the practice of initial and continuous teachers‟ formation, as well as for the formation of the former-researcher about the work with autobiographical narrations. Thus, it allow the co-investment of participants into the process of auto-formation and hetero-formation.

Inclusão de estudantes com deficiência no Instituto Federal da Paraíba a partir da ação TEC NEP

The current research developed in the Federal Institute of Paraíba – IFPB, João Pessoa Câmpus, aimed at analyzing the inclusion of students with disabilities in undergraduate courses based on the TEC NEP Action. It departs from the discussion about professional and special education in an inclusive perspective, focusing on people with disabilities, in the social context of these two modalities of education, considering the world scenario and the current Brazilian educational policy. It discusses the TEC NEP Action within the national and local context through the analysis of the official documents with the objective of getting familiarized and evaluating the process of educational inclusion in the IFPB João Pessoa Câmpus. The theoretical reference used contributed to the analysis of the policy which focused on inclusion in federal undergraduate institutions for professional education. The methodology used presents a qualitative analysis, having as subject of the research students with disabilities from undergraduate courses in the IFPB João Pessoa Câmpus who are supported by NAPNE. The results based on the analyzed data show that volunteer students from this research evaluate their process of inclusion in the appointed institution as positive, in spite of challenges specially the ones related to architectural barriers. It is concluded that the foundation of the House for Supporting People with Special Education Needs – (NAPNE) through the TEC NEP Action had crucial importance in the basis for the discussion about inclusion in the institution, widening the vision towards the demands of students with disabilities in order to facilitate access, permanence and academic success of these students.

A construção identitária em um fórum de discussão: um estudo com alunos da EAD

The aim of this study is to highlight the cultural identities of Spanish undergraduate students from Instituto Federal de Educação, Ciência e Tecnologia – IFRN, in integration with Universidade Aberta do Brasil – UAB, in the distance modality, built from utterances produced by them in a forum discussion online. For this, we chose to analyze the thematic forum “Using fragments of the internet is an ethical act?” generated in the first semester of 2011, linked to the Reading and Writing course. The interest of this researcher to highlight the cultural identities of these subjects, in the Virtual Learning Environment, emerged from the contact with this reality, in which it was found that the statements constructed by students were rich in positions, meanings and interactions. By producing their speeches, such subjects nurture a reflection on how we can establish meaning in the interaction created in online teaching as well as on the construction of cultural identities of the subject within that virtual space. The way students participate in the discussion forum represents learning experiences that lead to the construction of cultural identities, which determine the trajectory of the subjects, which makes the identity an ongoing process. Our theoretical reference follows the interdisciplinary approach of Applied Linguistics and is based on the socio-historical model of language, with language construed as a social practice. This study also established an interface with cultural studies, as it uses the concept of cultural identity in postmodernity. Analysis of the utterances lead to plurality, with a multiplicity of identities, as evidenced from the positioning of the subjects, some focused on the agreement, others on the disagreement, or even on the boldness. It was found also in the investigative path that these identities can be constructed and reconstructed if they are immersed in another set of historically determined social practices.

Desenvolvimento de um material têxtil termosenssível com micro/nanocápsulas imobilizadas em fibras regeneradas

Intelligent and functional Textile Materials have been widely developed and researched with the purpose of being used in several areas of science and technology. These fibrous materials require different chemical and physical properties to obtain a multifunctional material. With the advent of nanotechnology, the techniques developed, being used as essential tools to characterize these new materials qualitatively. Lately the application of micro and nanomaterials in textile substrates has been the objective of many studies, but many of these nanomaterials have not been optimized for their application, which has resulted in increased costs and environmental pollution, because there is still no satisfactory effluent treatment available for these nanomaterials. Soybean fiber has low adsorption for thermosensitive micro and nanocapsules due to their incompatibility of their surface charges. For this reason, in this work initially chitosan was synthesized to functionalise soybean fibres. Chitosan is a natural polyelectrolyte with a high density of positive charges, these fibres have negative charges as well as the micro/nanocápsules, for this reason the chitosan acts as auxiliary agent to cationize in order to fix the thermosensitive microcapsules in the textile substrate. Polyelectrolyte was characterized using particle size analyses and the measurement of zeta potential. For the morphological analysis scanning Electron Microscopy (SEM) and x-Ray Diffraction (XRD) and to study the thermal properties, thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), Near Infrared Spectroscopy analysis in the Region of the Fourier Transform Infrared (FTIR), colourimetry using UV-VIS spectrum were simultaneously performed on the substrate. From the measurement of zeta potential and in the determination of the particle size, stability of electrostatic chitosan was observed around 31.55mV and 291.0 nm respectively. The result obtained with (GD) for chitosan extracted from shrimp was 70 %, which according to the literature survey can be considered as chitosan. To optimize the dyeing process a statistical software, Design expert was used. The surface functionalisation of textile substrate with 2% chitosan showed the best result of K/S, being the parameter used for the experimental design, in which this showed the best response of dyeing absorbance in the range of 2.624. It was noted that soy knitting dyed with the thermosensitive micro andnanocapsules property showed excellent washing solidity, which was observed after 25 home washes, and significant K/S values.

Estrutura crustal e mantélica da província Borborema através de funções do receptor e dispersão de ondas superficiais

The Borborema Province, located in northeastern Brazil, has a basement of Precambrian age and a tectonic framework structured at the Neoproterozoic (740-560 Ma). After separation between South America and Africa during the Mesozoic, a rift system was formed, giving rise to a number of marginal and inland basins in the Province. After continental breakup, episodes of volcanism and uplift characterized the evolution of the Province. Plateau uplift was initially related to magmatic underplating of mafic material at the base of the crust, perhaps related to the generation of young continental plugs (45-7 Ma) along the Macau-Queimadas Alignment (MQA), due to a small-scale convection at the continental edge. The goal of this study is to investigate the causes of intra-plate uplift and its relationship to MQA volcanism, by using broadband seismology and integrating our results with independent geophysical and geological studies in the Borborema Province. The investigation of the deep structure of the Province with broadband seismic data includes receiver functions and surface-wave dispersion tomography. Both the receiver functions and surface-wave dispersion tomography are methods that use teleseismic events and allow to develop estimates of crustal parameters such as crustal thickness, Vp/Vs ratio, and S-velocity structure. The seismograms used for the receiver function work were obtained from 52 stations in Northeast Brazil: 16 broadband stations from the RSISNE network (Rede Sismográfica do Nordeste do Brasil), and 21 short-period and 6 broadband stations from the INCT-ET network (Instituto Nacional de Ciência e Tecnologia – Estudos Tectônicos). These results add signifi- cantly to previous datasets collected at individual stations in the Province, which include station RCBR (GSN - Global Seismic Network), stations CAUB and AGBL (Brazilian Lithosphere Seismic Project IAG/USP), and 6 other broadband stations that were part of the Projeto Milênio - Estudos geofísicos e tectônicos na Província Borborema/CNPq. For the surface-wave vii tomography, seismograms recorde at 22 broadband stations were utilized: 16 broadband stations from the RSISNE network and 6 broadband stations from the Milênio project. The new constraints developed in this work include: (i) estimates of crustal thickness and bulk Vp/Vs ratio for each station using receiver functions; (ii) new measurements of surfassewave group velocity, which were integrated to existing measurementes from a continental-scale tomography for South America, and (iii) S-wave velocity models (1D) at various locations in the Borborema Province, developed through the simultaneous inversion of receiver functions and surface-wave dispersion velocities. The results display S-wave velocity structure down to the base of the crust that are consistent with the presence of a 5-7.5 km thick mafic layer. The mafic layer was observed only in the southern portion of the Plateau and absent in its northern portion. Another important observation is that our models divide the plateau into a region of thin crust (northern Plateau) and a region of thick crust (southern Plateau), confirming results from independent refraction surveys and receiver function analyses. Existing models of plateau uplift, nonetheless, cannot explain all the new observations. It is proposed that during the Brazilian orogeny a layer of preexisting mafic material was delaminated, as a whole or in part, from the original Brasiliano crust. Partial delamination would have happened in the southern portion of the plateau, where independent studies found evidence of a more resistant rheology. During Mesozoic rifting, thinning of the crust around the southern Plateau would have formed the marginal basins and the Sertaneja depression, which would have included the northern part of the Plateau. In the Cenozoic, uplift of the northern Plateau would have occurred, resulting in a northern Plateau without mafic material at the base of the crust and a southern Plateau with partially delaminated mafic layer.

A atuação dos núcleos de apoio às pessoas com necessidades educacionais especiais no IFRN

The aim of this study was to evaluate the reality of the Service Centers for People with Special Educational Needs (NAPNEs) implanted at Instituto Federal de Educação, Ciência e Tecnologia do Rio Grande do Norte (IFRN) through a Professional Education Program in Technology for People with Special Educational Needs (TEC NEP Program). To reach the proposal we opted for an exploratory research with a qualitative approach characterized as a field of study. Data were obtained from questionnaires answered by thirteen (13) NAPNEs coordinators of different IFRN campuses and examined using content analysis. The survey results show that the creation of the TEC NEP program was an important step for inclusion policies in IFRN. However, difficulties were also identified by participants as coordinators: lack of physical infrastructure, human and material resources and financial matters, among others, as barriers to implementation and performance of NAPNEs. Keywords: TEC NEP Program, Professional Education, Inclusion, People with disabilities.

Síntese e caracterização de nanopartículas magnéticas de Co e Ni com aplicação em magneto hipertermia

Nanoparticles are importante for the study of new phenomena and for the development of new applications. Metallic magnetic nanoparticles like Cobalt and Nickel are important for their applications in nanoscience and nanotechnology. In this work, we report on the synthesis and characterization of Ni and Co nanoparticles. The nanoparticles were prepared by the modi- ed sol-gel method and were formed in the pore-network of the biopolymer quitosan. The reduction occurred in absence of H2 ux. The metallic particles and their monoxides have a face-centered- cubic structure. The metallic particles sizes ranged from 59 to 77 nm and from 19 to 50 nm for Ni and Co, respectively. Their monoxides chemically passivated the metallic cores, and after several weeks we have not observed further increase in oxidation. The synthesis method was tuned to obtain mainly the ferromagnetic phase. The system behaves like a core/shell structure with a ferromagnetic core and an antiferromagnetic shell. Exchange bias e ect was observed at temperatures below the Néel temperature. Both systems were submitted to an alternated magnetic eld and the heat released by the particles increased the temperature to 140°C in an interval of 5 min. Similar studies in samples dispersed in water increased the temperatures to 40-59°C, these results suggest that these materials are candidates for magnetic hyperthermia.