Analysis of the lightning attractive radius of power transmission lines through the use of a physically-oriented model

Models of different degrees of complexity are found in the literature for the estimation of lightning striking distances and attractive radius of objects and structures. However, besides the oversimplifications of the physical nature of the lightning discharge on which most of them are based, till recently the tridimensional structure configuration could not be considered. This is an important limitation, as edges and other details of the object affect the electric field and, consequently, the upward leader initiation. Within this context, the Self-consistent leader initiation and propagation model (SLIM) proposed by Becerra and Cooray is state-of-the-art leader inception and propagation leader model based on the physics of leader discharges which enables the tridimensional geometry of the structure to be taken into account. In this paper, the model is used for estimating the striking distance and attractive radius of power transmission lines. The results are compared with those obtained from the electrogeometric and Eriksson's models. © 2003-2012 IEEE.

As relações de trabalho nas Organizações Estratégicas no mundo contemporâneo: a ilusão da droga organização

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos de um programa de intervenção metatextual em escolares com dificuldades de aprendizagem

Pós-graduação em Educação - FFC

Nexos e reflexos de uma experiência formativa mediatizada por ambiente virtual de aprendizagem: formação de professores de Ciências e Matemática na Amazônia

Esta é uma pesquisa qualitativa na modalidade narrativa, que se baseia nas experiências de formação de professores de Ciências e Matemática a distância na Amazônia, vividas no contexto de um curso via Ambiente Virtual de Aprendizagem (AVA). Objetivo investigar em que termos essa experiência formativa é catalisadora de reflexões docentes sobre o contexto amazônico de ensino de Ciências e Matemática e que outras aprendizagens resultantes dessa formação repercutem em percepções diferenciadas da prática docente desta área específica no ensino fundamental. Foram nove os sujeitos envolvidos na investigação, os quais foram selecionados segundo os critérios: serem professores-alunos, oriundos do curso de Especialização em Educação em Ciências e Matemática do Programa EDUCIMAT, que ensinam/ensinaram Ciências e Matemática; mantiveram um elevado nível de envolvimento nas interações ocorridas no AVA; expressaram ideias completas de modo reflexivo. Como instrumento investigativo, optei por ouvir depoimentos dos sujeitos por meio de entrevista semi-estruturada, que foram gravadas em áudio e, posteriormente, transcritas. Além das entrevistas, lancei mão de meu diário de campo como fonte de informação, que foi construído ao longo da pesquisa por meio de percepções sobre os sujeitos e seus contextos, além dos registros de ocorrências diversas no âmbito da pesquisa. Buscando produzir novas compreensões das narrativas investigadas, aproprio-me da Análise Textual Discursiva como metodologia de análise do material empírico. Assim, ao sistematizar as manifestações dos sujeitos, levando em consideração as recorrências e as singularidades, tais análises deram forma a três eixos temáticos, que trato nesta investigação, assumindo os seguintes títulos: i) Formar-se no contexto amazônico: obstáculos e enfrentamentos; ii) Tecnologias e AVA: sentido(s) da experiência formativa; e iii) As repercussões da experiência nas percepções da prática e da formação docente. A análise dos resultados revela as dificuldades de acesso à formação, à informação, às tecnologias e aos municípios no interior da Amazônia, além do fator custo, como enfrentamentos para formar-se nesse contexto. Além disso, os sujeitos revelam que, ao trocarem, experimentarem e interagirem no AVA, atribuíram sentidos de autoconhecimento apontando indicativos para a (re)invenção de si, de constituição docente num mundo marcado pelos avanços tecnológicos e de superação no uso das tecnologias que surpreendem e (trans)formam. Ainda como resultado das análises, os sujeitos anunciam conhecimentos elaborados por meio da experiência formativa que incidem em outras/novas percepções de suas práticas educativas: a utilização de tecnologias de informação e comunicação como possíveis ferramentas pedagógicas, além da interatividade, troca de experiências e diálogo em situações de ensino. O AVA, sendo percebido pelos sujeitos como um dos recursos incorporados pela formação docente a distância, apresenta-se como oportunidade de contínua formação tecida pela diversidade de ideias e como forma de aproximar-se das tecnologias educacionais frente às dificuldades na região, expressas pelos próprios sujeitos.

A auto-avaliação em um contexto de ensino-aprendizagem de línguas em tandem via chat

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Transeuntes sobre ruínas: figurações alegóricas da casa familiar, no limiar de um certo exílio

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Analysis of 25 mutual eclipses and occultations between the Galilean satellites observed from Brazil in 2009

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Ethical Care of the Self and the Teacher in the Pedagogical Relationship: Reflections Based on the Latest Foucault

Our conception of education is that it is the responsible action whereby man becomes human, trains and faces the challenges that life and the world present, as man enters a larger, shared cultural tradition and thus joins the world. However such sharing implies that we must not just rely on tradition, but remain open to new ideas. It is essential for schooling to preserve a field where the art of living intersects with the world for which future generations are being prepared. It is in this field of intersection that this essay seeks to discuss Michel Foucault's thought, care of the self and the role played by others in the acquisition of ethical attitudes pertaining to one's conduct in life. Through reconstructing Foucault's ideas, we elaborate on the hypothesis that, before morally shaping students, teaching them values, or aiding in their skill acquisition in the sense prevailing in schooling today, it is important to understand the notion of care of the self (and how the notion implies interaction with others for effective care of the self). Care of the self is vital for thoroughly understanding the relationships between ethics and education in school. We particularly examine how Foucault's ideas and his analysis of the teacher's role in shaping the student's life conduct can help educators rethink pedagogical action in an ethical sense and find within it a certain openness to the formation of attitudes in educators and students

Influence of Nd:YAG Laser on the Bond Strength of Self-etching and Conventional Adhesive Systems to Dental Hard Tissues

Purpose: The aim of this study was to investigate the influence of Nd:YAG laser on the shear bond strength to enamel and dentin of total and self-etch adhesives when the laser was applied over the adhesives, before they were photopolymerized, in an attempt to create a new bonding layer by dentin-adhesive melting.Material and Methods: One-hundred twenty bovine incisors were ground to obtain flat surfaces. Specimens were divided into two substrate groups (n=60): substrate E (enamel) and substrate D (dentin). Each substrate group was subdivided into four groups (n=15), according to the surface treatment accomplished: X (Xeno III self-etching adhesive, control), XL (Xeno III + laser Nd:YAG irradiation at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental), S (acid etching + Single Bond conventional adhesive, Control), and SL (acid etching + Single Bond + laser Nd:YAG at 140 mJ/10 Hz for 60 seconds + photopolymerization, experimental). The bonding area was delimited with 3-mm-diameter adhesive tape for the bonding procedures. Cylinders of composite were fabricated on the bonding area using a Teflon matrix. The teeth were stored in water at 37 degrees C/48 h and submitted to shear testing at a crosshead speed of 0.5 mm/min in a universal testing machine. Results were analyzed with three-way analysis of variance (ANOVA; substrate, adhesive, and treatment) and Tukey tests (alpha=0.05). ANOVA revealed significant differences for the substrate, adhesive system, and type of treatment: lased or unlased (p<0.05). The mean shear bond strength values (MPa) for the enamel groups were X=20.2 +/- 5.61, XL=23.6 +/- 4.92, S=20.8 +/- 4.55, SL=22.1 +/- 5.14 and for the dentin groups were X=14.1 +/- 7.51, XL=22.2 +/- 6.45, S=11.2 +/- 5.77, SL=15.9 +/- 3.61. For dentin, Xeno III self-etch adhesive showed significantly higher shear bond strength compared with Single Bond total-etch adhesive; Nd:YAG laser irradiation showed significantly higher shear bond strength compared with control (unlased).Conclusion: Nd:YAG laser application prior to photopolymerization of adhesive systems significantly increased the bond strength to dentin.

A real-time thermal field theoretical analysis of Kubo-type shear viscosity: Numerical understanding with simple examples

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação do desempenho das propriedades mecânicas de concretos self compacting elaborados com diferentes tipos de cimentos submetidos à cura térmica

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A Comparative Analysis of In-Medium Spectral Functions for N(940) and N (au)(1535) in Real-Time Thermal Field Theory

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Evaluation of the Capillary Blood Glucose Self-monitoringProgram

OBJECTIVE: to evaluate the structure, process and results of the Capillary Blood Glucose Self-monitoring Program in a Brazilian city. METHOD: epidemiological, cross-sectional study. The methodological framework of Donabedian was used to construct indicators of structure, process and outcome. A random sample (n = 288) of users enrolled and 96 health professionals who worked in the program was studied. Two questionnaires were used that were constructed for this study, one for professionals and one for users, both containing data for the evaluation of structure, process and outcome. Anthropometric measures and laboratory results were collected by consulting the patients' health records. The analysis involved descriptive statistics. RESULTS: most of the professionals were not qualified to work in the program and were not knowledgeable about the set of criteria for patient registration. None of the patients received complete and correct orientations about the program and the percentage with skills to perform conducts autonomously was 10%. As regards the result indicators, 86.4% of the patients and 81.3% of the professionals evaluated the program positively. CONCLUSION: the evaluation indicators designed revealed that one of the main objectives of the program, self-care skills, has not been achieved.

Self-perception, complaints and vocal quality among undergraduate students enrolled in a Pedagogy course

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chemical analysis and Vickers hardness of orthodontic mini-implants

Orthodontic mini-implants are used in clinical practice to provide efficient and aesthetically-pleasing anchorage. AIM: To evaluate the hardness Vickers hardness and chemical composition of mini-implant titanium alloys from five commercial brands. METHODS: Thirty self-drilling mini-implants, six each from the following commercial brands, were used: Neodent NEO, Morelli MOR, Sin SIN, Conexão CON, and Rocky Mountain RMO. The hardness and chemical composition of the titanium alloys were performed by the Vickers hardness test and energy dispersive X-ray spectroscopy, respectively. RESULTS: Vickers hardness was significantly higher in SIN implants than in NEO, MOR, and CON implants. Similarly, VH was significantly higher in RMO implants than in MOR and NEO ones. In addition, VH was higher in CON implants than in NEO ones. There were no significant differences in the proportions of titanium and aluminum in the mini-implant alloy of the five commercial brands. Conversely, the proportion of vanadium differed significantly between CON and MOR/NEO implants. CONCLUSIONS: Mini-implants of different brands presented distinct properties of hardness and composition of the alloy.