Elastic modulus and hardness of CaTiO3, CaCu3Ti4O12 and CaTiO3/CaCu3Ti4O12 mixture

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of vanadium on electrical and microstructural properties of CaCu3Ti4O12/CaTiO3

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influence of degradation on the electrical conduction process in ZnO and SnO2-based varistors

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

Hydrothermal Microwave: A New Route to Obtain Photoluminescent Crystalline BaTiO3 Nanoparticles

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Festa na escola e a autopoiese do lazer

This study shows the problem of school party and its relations with the perspective of leisure autopoiesis in the lives of students living in student housing. It has aimed to describe and interpret the most meaningful leisure experiences in daily life of a student housing and the ludopoietic processes for the humanescent self-education. From the theoretical assumptions supporting the development of this research have highlighted: Education by Freire (1996); Embodiment by Pierrakos (1990); Leisure by Dumazedier (1999); Party by Duvignaud (1983), Playful by Schiller (2002), Working by Freinet (1998), Autopoiesis by Maturana and Varela (2001), belonging to each day by Certeau (1994). A qualitative study adopts the principles of existential action research, in an ethnofenomenological perspective. As a methodology, we use the metaphor of sowing covering the planting, flowering, harvest and new planting. The scenario was to sow the Escola Agrícola de Jundiaí - RN. Twenty-five students residing in the school participated in research from 2007 to 2008, which involved more actively in the development of an extension project for the implementation of recreational and leisure experiences in that institution. The main instruments used for the construction of data collection were: participant observation, questionnaire, interview, game sand and photographs. The process of data analysis with the ethnofenomenological principles emphasized the following points: experientiality, indexicality, reflexivity, self-organizability, adoptability, archetypal and humanescenciality. New meanings of ludopoietic flowering of seed "party school" were revealed, and you can see the emergence of autopoietic leisure as a big green tree, able to sprout in soil properly fertilized to produce wonderful fruit of joie de vivre

Tessituras poéticas da corporeidade na formação humana do educador infantil

Cette étude a comme sujet principal la formation humaine de l instituteur. L objectif général est d analyser et décrire les conditions créées par les vécus d un atelier corps biographique pour la resignification de la corporéité de l instituteur, fixant les questions suivantes pour l investigation : Quelles sont les implications du vécu de l atelier corps biographique dans la vie des instituteurs ? La recherche a été exposée sur l approche qualitative, suivant les principes de la recherche-action reliée à la méthode des histoires de vie. Pour révéler la beauté et la complexité du processus poïétique de la formation humaine, nous nous sommes servi de la métaphore du "dessus de lit en patchwork" comme opérateur cognitif en attachant les principes de la corporéité fondés sur la Théorie de la complexité (MORIN, 2005), la Théorie autopoïétique (MATURANA ; VARELA, 2001), la Théorie du flux (CSIKSZENTMIHALYI, 1999), les approches de transdisciplinarité (LA TORRE; MORAES, 2008), et d autobiographie (JOSSO, 2004; PINEAU, 2003; PASSEGGI, 2000;), joignant la conception de l éducation comme pratique d autonomie, de liberté, d espoir et de l enchantement (FREIRE, 1996, 1992; ASSMANN, 1995). Nous avons eu comme scène du développement de la recherche, l Unidade Educacional Infantil (UEI), la garderie qui accueille les enfants des fonctionnaires de l Université Fédérale du Rio Grande do Norte. Treise élèves (enfants), des institutrices titulaires, vacataires, boursières ont participé de l'investigation. En conptant sur eux, nous avons développé un atelier corps biographique, dans lequel nous avons réalisé 10 vécus dans la période qui a couvert le deuxième semestre de 2007 jusqu au deuxième semestre de 2008, en manifestant la réflexivité autobiographique, le ludique, la créativité, la sensibilité et la réflexivité du vécu. Nous avons utilisé comme instruments pour la construction des donnés, l observation participante, les propres vécus, le port folio, la technique du jeu de sable et l'enregistrement photographique. L analyse a montré que le vécu de la formation humaine à partir des principes de la corporéité, implique dans un parcours vers soi-même dans lequel émergent les expériences qui nous ont constitués en tant qu êtres existentiels. Pour finaliser, nous avons aperçu les répercussions dans la vie professionnelle et personnelle de ces institutrices, qui comme moi pensaient avoir besoin d exposer leur luminosité intérieure pour que l on la redécouvre. Lors des vécus des tissages, les institutrices se sont montrées impliquées aux moments de jeux, de création, de réalisation, d afection et d action réflexive, dans lesquelles la teneur humaine cachée, a été révélée, en ouvrant les possibilités pour le sentiment du mouvement de naissance de l humanisation intérieure. Pour conclure, le corps joyeux de savoir et de beauté a été révélé, et dans sa rencontre avec soi-même et avec l autre, a pu être auto- recréé

Materiais cerâmicos de inserção aplicados a baterias de íons lítio

Esta revisão visa ser uma introdução à aplicação de materiais cerâmicos em dispositivos de armazenamento de energia, em especial baterias secundárias de íons lítio, dispositivos nos quais os materiais cerâmicos, especialmente óxidos, são muito importantes em todas as partes do dispositivo. A revisão está focada nos materiais cerâmicos para catodos e anodos, partes chaves destes dispositivos. Ela tem por principal finalidade ser uma fonte de informação para aqueles que desejem trabalhar com o desenvolvimento de materiais cerâmicos para tais tipos de dispositivos. Aspectos relacionados à nanotecnologia e materiais óxidos nanoestruturados para esta área são discutidos ao final do artigo.

(1-x)PMN-xPT ceramics prepared by conventional and modified columbite route: Effect on electrical properties

This study aims to demonstrate how the chemical homogeneity of B cations affects the microstructure and electrical responses of (1-x) PMN-xPT ceramics. Two methodologies were employed to synthesize three different compositions, with x assuming the values 0.10, 0.28, and 0.35. If compared to conventional method, the Ti-modified columbite route, which is characterized by higher B cation homogeneity, leads to PMN-PT powders and ceramics with lower content of PNT pyrochlore phase and, for 0.65PMN-0.35PT composition, minor amount of tetragonal phase is found. Conclusively, PMN-PT ceramics obtained by modified route favors B cations homogeneity, enhancing the dielectric, ferroelectric and piezoelectric properties.

Effect of lithium additive on the microstructure and electrical responses of 0.9PMN-0.1PT ceramics

Structural effects of lithium additive on 0.9PMN-0.1PT powders prepared by Ti-modified columbite route were studied. The substitution of Li+ ions for Mg2+ ions in the B-site sub-lattice of 0.9PMN-0.1PT perovskite structure was explained in terms of lead and oxygen vacancies generation originated as consequence of the ionic compensation of negatively charged Li'(Mg) sites. The rise in mass transport as consequence of the increasing of Pb2+ and O2- vacancies produces more agglomerated particles during the powder synthesis and changes the mechanical characteristics between grain and grain boundary of sintered ceramic. The relation between K-m and T-m values, the difference between ionic radii of B cation and the molar volume were used to explain the changes in the relaxor behavior and diffusiveness of phase transition as function of lithium doping, which are corroborated by the results obtained through the ferroelectric characterization.

Characterization of silica-carbon mesoporous matrix with embedded nickel nanoparticles synthesized by the polymeric precursor method

Nickel nanoparticles into silica-carbon matrix composites were prepared by using the polymeric precursor method. The effects of the polyester type and the time of pyrolysis on the mesoporosity and nickel particle dispersion into non-aqueous amorphous silica-carbon matrix were investigated by thermogravimetric analysis, adsorption/desorption isotherms and TEM. A well-dispersed metallic phase could be only obtained by using ethylene glycol. Weightier polyesters affected the pyrolysis process due to a combination of more amounts of carbonaceous residues and delaying of pyrolysis process. The post-pyrolyzed composites were successfully cleaned at 200 degrees C for I h in oxygen atmosphere leading to an increase in the surface area and without the occurrence of carbon combustion or nickel nanoparticles oxidation. The matrix composites presented predominantly mesoporous with pore size well defined in 38 angstrom, mainly when tetraethylene glycol was used as polymerizing agent. (C) 2007 Elsevier B.V. All rights reserved.

Characterization of the columbite precursor and (1-x)PMN-xPT powders prepared by Ti-modified columbite route

This study proposes to synthesize (1-x)PMN-xPT powders, where 0.10 < x < 0.45, using the T-modified columbite route. This methodology consists in the preparation of the MNT columbite precursor via the polymeric precursor method, followed by the solid state reaction with PbO to get the PMN-PT powders. It was verified that from 15 mol% of Ti, the MNT presents the coexistence of two main phases with different crystal symmetry: Rutile and Columbite. However, the synthesis of (1-x)PMN-xPT powders is not affected by this event. A detailed study of structural effects in MNT and PMN-PT powders as function of Ti content was made using the Rietveld method. It was also demonstrated that powders possess high chemical and microstructural homogeneity.

CMS physics technical design report, volume II: Physics performance

CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider ( LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking - through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start- up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb(-1) or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B-s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb(-1) to 30 fb(-1). The Standard Model processes include QCD, B-physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z(0) boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2-6 describe examples of full analyses, with photons, electrons, muons, jets, missing E-T, B-mesons and tau's, and for quarkonia in heavy ion collisions. Chapters 7-15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model.

Search for narrow resonances in dilepton mass spectra in pp collisions at root s=7 TeV CMS Collaboration

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Search for the standard model Higgs boson decaying to bottom quarks in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

First measurement of hadronic event shapes in pp collisions at root s=7 TeV

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)