Do mestre aos discípulos: o legado educacional de Nestor dos Santos Lima (1910-1930)

Cette étude analyse La pratique pédagogique de l éducateur norte-rio-grandense Nestor dos Santos Lima, de 1910 a 1930, période ou se concentre son plus grand nombre de publications sur lês questions scolaires. Nous désirons comprendre de quelle forme cet intelectuel a contribué au développement du systeème d enseignement primaire à travers sés écrits sur lês principes et méthodes de l enseignement de la lecture et à l écriture, appliqués dans lês Groupes Scolaires de l État. Nestor Lima a joué um grand role dans la sociaété, à la tetê de fonctoins comme celle de La présidence de l Institut Historique e Geographique du Rio Grande do Norte (IHGRN), directeur de lÉcole Normale de Natal et du Dápartament d Education de État. Il a pulié de diverses oeuvres de caractere scolaire, comme lês Régiments Internes pour lês Groupes Scolaires, Écoles Isolées, Écoles Rudimentaires et Conseil d Education. Dans cette étude, nous mettons em évidence lês leçons de métodologique pour l enseignement de la lecture ET de évidence lês leçons de metodologie pour l enseignement de la lecture et de l ecriture, adresses aus eleves de lÉcole Normale de Natal, publiées dans la colonne Pádagogie du journal A República. Dans ces matièrs, nous observons que lês aspects qui composaient la pratique développe par Nestor Lima impliquaient lês questions Morales et civiques, la preocupation de la formation enseignante à l École Normale de Natal et le Célibat Pédagogique Féminin. Nous observons que la preocupations dês pratiques de lecture et lécriture sont presentes dans l oeuvre de cet éducateur comme legs important aux générations qui se succédent. Il est évident qu Il a cherché das sés productions une meilleure qualification dês enseignants pour que le niveau de l enseignement primaire puísse ainsi évoluer

No caminho das artes marciais: a relação mestre e discípulo como educação sensível

This research reflects the relationship between Master and Disciple original from the Martial Arts, and anchors their focus on sensitive education that emerges from this relationship. The interest here is knowing how the tradition of millenarian teachings is passed through the years, and how it gives from the relationship of Master and Disciple. To that end, I lean me in that context and also reflect on my experience as a Disciple of the Martial Arts, to that end, I lean me in that context and also reflect on my experience as a Disciple of the Martial Arts, and is from the immemorial fund that can give voice to that experience, through my body attached in the world of significations in which the experience lived is narrated by the story. Anchored from the phenomenological attitude from the philosopher french Maurice Merleau-Ponty, I think this research on three central pillars to guide our study categories, namely: the lived experience, body and liberty. Still, as a form of highlighting this sensitive work, beyond the texts of the philosopher Merleau-Ponty, we bring our dialogue of the cinema, literature and the writings of some the Masters of Martial Arts. For that, I think this research as a journey, where it, Master and Disciple march together in the ways of Martial Arts, baptizing and celebrating this sensitive education from that relationship affective and empathic

Estudo do efeito do óxido de bário no comportamento de massas para porcelanato

In this work, it is proposed the study of the effect of barium oxide acting as synthetic flow in the behavior of masses for stoneware from the use of raw materials found in the deposits of minerals of the Rio Grande do Norte that it makes use of a great natural potential for the industrialization of the product. The porcelanato is a sophisticated product with excellent final properties being applied as ceramic coating in buildings of high standard of engineering. The raw materials selected for the development of the study had been two types of argilas, two types of feldspatos, dolomita, talco, barium carbonate and silica, being characterized by X-ray fluorescence, X-ray diffraction, granulometric analysis, dilatometric analysis and thermal analysis. Thus, it is intended to define four formulations using the cited raw materials that will be processed, conformed and sintered in the temperatures of 1150 °C, 1175 °C, 1200 °C, 1225 °C e 1250 °C. From the physical characterizations, chemical and morphologic of the formed formulations, the effect of barium oxide is determined in the physical and mechanical properties of the studied system carrying water absorption tests, linear retraction, apparent porosity, apparent specific mass, compacting curve, flexural strength and microstructural analysis by XRD and SEM. After analyzing the results, indicated that barium oxide acts as a flux of high temperature and as the ordering of structure, where the embedded glass phase has the nucleating effect phase potassium silico-aluminum reacting with free silica which together with the high content of potassium concentrated form a new crystalline phase called microcline. The masses studied with the addition of barium oxide present physical-mechanical properties highly satisfactory in reduced firing temperatures, which implies a saving in energy given off in the production and increased productivity

Influência do teor e granulometria da calcita e da temperatura de sinterização no desenvolvimento de massas cerâmicas para revestimento poroso(BIII)

This work aims at studying the influence of the concentration of calcite, its grain size and sintering temperature to obtain porous coating formulations that meet the design specifications. The experiments involved the physical-chemical and mineralogical caracterization of the raw materials, and mechanical tests on specimens dried and sintered, performing a planning mixture and factorial experiment, using the response surface methodology. The ceramic bodies studied were prepared by dry process, characterized, placed in conformity by uniaxial pressing and sintered at temperatures of 940 º C, 1000ºC, 1060ºC, 1120°C and 1180°C using a fast-firing cycle. The crystalline phases formed during sintering at temperatures under study, revealed the presence of anorthite and wolastonite, and quartz-phase remaining. These phases were mainly responsible for the physical and mechanical properties of the sintered especimens. The results shown that as increases the participation of carbonate in the composition of ceramic bodies there is an increase of water absorption and a slight reduction in linear shrinkage for all sintering temperatures. As for the mechanical strength it was observed that it tended to decrease for sintering at temperatures between 940 ° C and 1060 ° C and to increase for sintering at temperatures above 1060 ° C occurring with greater intensity for compositions with higher content of calcite. The resistence decreased with increasing participation of quartz in all sintering temperatures. The decrease in grain size of calcite caused a slight increase in water absorption for formulation with the same concentration of carbonate, remaining virtually unchanged the results of linear shrinkage and mechanical strength. In conclusion, porous ceramic coating (BIII) can be obtained using high concentrations of calcite and keeping the properties required in technical standards and that the particle size of calcite can be used as tuning parameter for the properties of ceramic products.

Vida sem-porquê em Mestre Eckhart : desprendimento e cotidiano

Diese Masterthese beschäftigt sich mit der Erforschung der Frage nach dem Begriff Leben ohne Warum basierend auf den Werken des Meisters Eckhart, genauer gesagt, auf den Deutschen Predigten , auf Das Buch der göttlichen Tröstung , Von dem edlen Menschen , Die Reden der Unterweisung und Von Abgeschiedenheit . Bei der Theorie der Abgeschiedenheit versucht man die Idee des Lebens ohne warum zu verstehen und zu zeigen, die Gott und der Mensch ent-decken kann. So wird erstmals eine Reflexion darüber beschrieben, was Abgeschiedenheit ist, und zwar mittels dreier Dimensionen: Ontik, Ontologisch und Mystik. Die Ontik der absoluten Armut fordert eine Analyse der Ontologie aller Ontik und das bedeutet nach Eckhart das Gotteswesen in seiner Gottheit, die unbegreifbar für den Menschen ist. Unterdessen bringt die Analyse des Wesens Gottes des Menschenlebens wieder die Einheit zwischen dem Ontischen und dem Ontologischen in der Welt. Die mystische Dimension begründet diese Einheit als Absolutum ohne Warum . Aber die Möglichkeit des Sprechens und des Denkens über die Abgeschiedenheit führt zum erfüllten Leben. Es gibt keine endgültige Predigt, keine wundersame Methode, keinen bekannten Weg oder keine leistungsfähige Strategie dafür nur in der Vollendung des Lebens ist es möglich, die subtile Äusserung von Gott, die uns entgeht, zu empfinden. Um diese Erfüllung zu erklären und die Lebensbedeutung als ohne Warum zu verstehen, untersucht diese Masterthese unter vier Perspektiven: arché und telos des Lebens, die Zeit unter dem Begriff des nun, das verbum und das ego sum qui sum, was das Leben als ohne Warum beweist und die Beharrlichkeit in der täglich von der Welt verstandenen Transzendenz. Es ist schwierig die Tiefe des Leben-ohne-Warum-Begriffs von Meister Eckhart auszudrücken, weil seine ganze Bemühung darin besteht, die Kräfte dieser Ent-deckung vor einer begrenzten Bestimmung zu schützen. Und in dieser Hinsicht öffnet er einen neuen Horizont für den Grund des Lebens. Es gibt keine Routine und Determination bei Meister Eckhart. Alles, was ist, spiegelt das Außerordentliche, seine dringende Absicht ist die Widerherstellung der Einheit mit dem Gegenwärtigen, mit dem Wesentlichen, mit dem Leben im Alltag ohne Warum

Estudos de sinterização da mistura de pós cerâmicos diatomita-titânia

This work is part of an effort of consolidation of a daily search for powder technology at the Department of Physics of the Universidade Federal do Rio Grande do Norte. This work objective the study and development of new ceramic materials from raw materials abundant at the region. For this, were studied ceramic mixtures of powders from diatomite-titania to aiming at a new ceramic material from powder technology. The experimental work involved a characterization of ceramic powders from a diatomite-titania mixture. The powders obtained were pressed and then parameters like variation of mass, linear shrinkage, activation energy and the mechanism of sintering are studied in function of the time and temperature of sintering, beyond microstructural analysis. The obtained results allow us estimate the optimizing of sintering conditions of this material

Síntese, sinterização e caracterização de ferritas à base de Ni-Zn

Were synthesized different ferrites NixZn1-xFe2O4 (0,4 ≤ x ≤ 0,6) compositions by using citrate precursor method. Initially, the precursors citrates of iron, nickel and zinc were mixed and homogenized. The stoichiometric compositions were calcined at 350°C without atmosphere control and the calcined powders were pressed in pellets and toroids. The pressed material was sintered from 1100º up to 1200ºC in argon atmosphere. The calcined powders were characterized by XRD, TGA/DTG, FTIR, SEM and vibrating sample magnetometer (VSM). All sintered samples were characterized using XRD, SEM, VSM and measurements of magnetic permeability and loss factor were obtained. It was formed pure ferromagnetic phase at all used temperatures. The Rietveld analyses allowed to calculate the cations level occupation and the crystallite size. The analyses obtained nanometric crystals (12-20 nm) to the calcined powder. By SEM, the sintered samples shows grains sizes from 1 to 10 μm. Sintered densities (ρ) were measured by the Archimedes method and with increasing Zn content, the bulk density decrease. The better magnetization results (105-110 emu/g) were obtained for x=0,6 at all sintering temperatures. The hysteresis shows characteristics of soft magnetic material. Two magnetization processes were considered, superparamagnetism at low temperature and the magnetic domains formation at high temperatures. The sintered toroids presents relative magnetic permeability (μr) from 7 to 32 and loss factor (tanδ) of about 1. The frequency response of toroids range from 0,3 kHz to 0,2 GHz. The composition x=0,5 presents both greater μr and tanδ values and x=0,6 the most broad range of frequency response. Various microstructural factors show influence on the behavior of μr and tanδ, such as: grain size, porosity across grain boundary and inside the grain, grain boundary content and domain walls movement during the process of magnetization at high frequency studies (0,3kKz 0,2 GHz)

Mestre em Sistemas e Computação

In this work will applied the technique of Differential Cryptanalysis, introduced in 1990 by Biham and Shamir, on Papílio s cryptosystem, developed by Karla Ramos, to test and most importantly, to prove its relevance to other block ciphers such as DES, Blowfish and FEAL-N (X). This technique is based on the analysis of differences between plaintext and theirs respective ciphertext, in search of patterns that will assist in the discovery of the subkeys and consequently in the discovery of master key. These differences are obtained by XOR operations. Through this analysis, in addition to obtaining patterns of Pap´ılio, it search to obtain also the main characteristics and behavior of Papilio throughout theirs 16 rounds, identifying and replacing when necessary factors that can be improved in accordance with pre-established definitions of the same, thus providing greater security in the use of his algoritm

Produção de estrutura com gradiente de porosidade a partir da sinterização por plasma da mistura de pós Ti-Nb-Sn

Porous structures are being widely investigated for use in biomedical implants, aiming to mechanically integrate and functionally the implant inside the bone tissue. Moreover, this structure is also important for drugs that can be stored and can induce and accelerate the process of osseointegration. With the purpose to investigate this effect, Ti, Nb and Sn metal powders, were sintered by plasma using a hollow cathode discharge. Sintering was performed in argon plasma set at 4 mbar pressure and temperatures of 500 ° C, 600 ° C and 700 ° C. Samples were also sintered in the electrical resistance furnace at 1200 ° C in order to compare plasma sintering with the conventional method. It was observed that plasma samples sintered with the hollow cathode configuration showed a gradient in porosity, while the samples sintered in the resistive furnace did not. Furthermore, differences in the microstructure of the samples were found, were a surface with higher porosity and ales porous core were obtained at different temperatures. The percolation profile of distilled water and the chemical compositions of the porous layers of the plasma treated samples were the main results obtained. Based on these results, we can conclude that this structure is particularly important for application in the biomedical field such as scaffolds for drug delivery and implants

Redução in situ de NIO durante a sinterização de misturas NI/NIO produzidas por metalurgia do pó

The nickel alloys are widely used in the production of various materials, especially those that require mechanical strength characteristics associated with resistance to corrosion, for example, the stainless steel. Another use is the production of nickel alloy sintered from powder of metallic nickel. A promising alternative for the production of sintered components of nickel with an important reduction in costs of starting material is the use of mixtures of powders of Ni-NiO. This work aimed to study in situ reduction of NiO during sintering mixtures of Ni / NiO produced by powder metallurgy. The nickel mixtures have been processed by the technique of powder metallurgy and were pre-sintered in an oven under plasma reducing atmosphere of hydrogen. Mixtures Ni +15%NiO, Ni +25%NiO and Ni +35%NiO were studied and compared with samples consisting only of metallic Ni. Dilatometric tests were performed to study the sintering conditions of the mixtures. The consolidated material was analyzed for their microstructure and microhardness. Dilatometry graphs showed that the addition of nickel oxide in all compositions the active sintering the mixtures studied. In tests of microhardness indentations were made at different points of the sample surface. All compositions showed microhardness values close to the consolidated material from metallic nickel. However, sample containing Ni+35% NiO, showed a large dispersion of the values of microhardness tests performed at different points of the sample surface. Microstructural analysis of the material showed a higher concentration of voids and the presence of oxides in the waste composition of the mixtures Ni 35% NiO. The samples containing Ni+15%NiO showed microstructural characteristics and mechanical properties similar to metallic nickel consolidated under the same conditions of the compositions studied in this work and therefore had great potential for production of sintered nickel alloys

Estudo do comportamento da sinterização de compactos de cavacos de um aço SAE 1050 obtidos sob alta pressão

From an economic standpoint, the powder metallurgy (P/M) is a technique widely used for the production of small parts. It is possible, through the P/M and prior comminution of solid waste such as ferrous chips, produce highly dense sintered parts and of interest to the automotive, electronics and aerospace industries. However, without prior comminution the chip, the production of bodies with a density equal to theoretical density by conventional sintering techniques require the use of additives or significantly higher temperatures than 1250ºC. An alternative route to the production of sintered bodies with high density compaction from ferrous chips (≤ 850 microns) and solid phase sintering is a compression technique under high pressure (HP). In this work, different compaction pressures to produce a sintered chip of SAE 1050 carbon steel were used. Specifically, the objective was to investigate them, the effect of high pressure compression in the behavior of densification of the sintered samples. Therefore, samples of the chips from the SAE 1050 carbon steel were uniaxially cold compacted at 500 and 2000 MPa, respectively. The green compacts obtained were sintered under carbon atmosphere at 1100 and 1200°C for 90 minutes. The heating rate used was 20°C/min. The starting materials and the sintered bodies were characterized by optical microscopy, SEM, XRD, density measurements (geometric: mass/volume, and pycnometry) and microhardness measurements Vickers and Rockwell hardness. The results showed that the compact produced under 2000 MPa presented relative density values between 93% and 100% of theoretical density and microhardness between 150 HV and 180 HV, respectively. In contrast, compressed under 500 MPa showed a very heterogeneous microstructure, density value below 80% of theoretical density and structural conditions of inadequate specimens for carrying out the hardness and microhardness measurements. The results indicate that use of the high pressure of ferrous chips compression is a promising route to improve the sinterability conditions of this type of material, because in addition to promoting greater compression of the starting material, the external tension acts together with surface tension, functioning as the motive power for sintering process. Additionally, extremely high pressures allow plastic deformation of the material, providing an intimate and extended contact of the particles and eliminating cracks and pores. This tends to reduce the time and / or temperature required for good sintering, avoiding excessive grain growth without the use of additives. Moreover, higher pressures lead to fracture the grains in fragile or ductile materials highly hardened, which provides a starting powder for sintering, thinner, without the risk of contamination present when previous methods are used comminution of the powder.

Um olhar crítico sobre a individualização da curva de compensação em prótese total

Objetivo: Buscar na literatura evidências científicas que suportem os benefícios da individualização da curva de compensação em prótese total, pela técnica do desgaste de Paterson, em relação à curva de compensação não individualizada. Metodologia: Realizou-se, em Dezembro de 2009, uma revisão sistemática da literatura nas bases de dados MEDLINE, LILACS e BBO com os termos “prótese total” e “oclusão”. Para abranger uma maior quantidade de dados, realizou-se uma busca manual através das referências dos artigos inicialmente selecionados. Resultados: Obteve-se 1273 referências na base dados MEDLINE, 64 na LILACS e 103 na BBO, num total de 1440 referências. Dessas, apenas 24 tratavam do assunto “curva de compensação”, as quais somaram-se mais 13 artigos selecionados manualmente. Conclusão: A partir dos resultados obtidos, conclui-se que não existem dados suficientes que comprovem clinicamente os benefícios da individualização da curva de compensação em relação às próteses totais com curva de compensação não individualizada. Ensaios clínicos controlados e randomizados são necessários para que se possa determinar qual o procedimento mais adequado.

Um olhar crítico sobre a individualização da curva de compensação em prótese total

Objetivo: Buscar na literatura evidências científicas que suportem os benefícios da individualização da curva de compensação em prótese total, pela técnica do desgaste de Paterson, em relação à curva de compensação não individualizada. Metodologia: Realizou-se, em Dezembro de 2009, uma revisão sistemática da literatura nas bases de dados MEDLINE, LILACS e BBO com os termos “prótese total” e “oclusão”. Para abranger uma maior quantidade de dados, realizou-se uma busca manual através das referências dos artigos inicialmente selecionados. Resultados: Obteve-se 1273 referências na base dados MEDLINE, 64 na LILACS e 103 na BBO, num total de 1440 referências. Dessas, apenas 24 tratavam do assunto “curva de compensação”, as quais somaram-se mais 13 artigos selecionados manualmente. Conclusão: A partir dos resultados obtidos, conclui-se que não existem dados suficientes que comprovem clinicamente os benefícios da individualização da curva de compensação em relação às próteses totais com curva de compensação não individualizada. Ensaios clínicos controlados e randomizados são necessários para que se possa determinar qual o procedimento mais adequado.

Efeito da adição de WC e Co na sinterização e propriedades mecânicas da alumina

Composites based on alumina (Al2O3), tungsten carbide (WC) and cobalt (Co) exhibit specific properties such as low density, high oxidation resistance, high melting point and high chemical inertia. That composite shows to be a promising material for application in various fields of engineering. In this work, the mechanical properties of the composite (Al2O3 – WC – Co), particularly density and hardness, were evaluated according to the effects of the variables of powder processing parameters, green compact and sintered. Powder composites with the composition of 80 wt% Al2O3, 18 wt% WC and 2 wt% Co were processed by high energy ball milling in a planetary mill for 50 hours as well as mixed by manual mixing in a glass vessel with the same proportion. Samples were collected (2, 10, 20, 30, 40 and 50 hours) during the milling process. Then, the powders were compacted in a cylindrical die with 5 mm in diameter in a uniaxial press with pressures of 200 and 400 MPa. The sintering was in two stages: first, the solid phase sintering was performed at 1126 and 1300 °C for 1 hour with a heating rate of 10 °C/min in a resistive furnace under argon atmosphere for green samples compacted in 200 and 400 MPa; the second sintering was performed on dilatometer in solid phase at 1300 °C for green sample compacted in 200 MPa, another sintering also was performed on dilatometer, this time in liquid phase at 1550 °C for green samples compacted in 200 and 400 MPa, with the same parameters used in resistive furnace. The raw materials were characterized by X – ray diffraction (XRD), X – ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and laser particlemeter. The sintered samples were subjected to microhardness testing. The results showed that high energy milling achieved to the objectives regarding the particle size and the dispersion of composite phases. However, the hardness did not achieve to significant results, this is an indication that the composite has low fracture toughness.

Efeito da adição de WC e Co na sinterização e propriedades mecânicas da alumina

Composites based on alumina (Al2O3), tungsten carbide (WC) and cobalt (Co) exhibit specific properties such as low density, high oxidation resistance, high melting point and high chemical inertia. That composite shows to be a promising material for application in various fields of engineering. In this work, the mechanical properties of the composite (Al2O3 – WC – Co), particularly density and hardness, were evaluated according to the effects of the variables of powder processing parameters, green compact and sintered. Powder composites with the composition of 80 wt% Al2O3, 18 wt% WC and 2 wt% Co were processed by high energy ball milling in a planetary mill for 50 hours as well as mixed by manual mixing in a glass vessel with the same proportion. Samples were collected (2, 10, 20, 30, 40 and 50 hours) during the milling process. Then, the powders were compacted in a cylindrical die with 5 mm in diameter in a uniaxial press with pressures of 200 and 400 MPa. The sintering was in two stages: first, the solid phase sintering was performed at 1126 and 1300 °C for 1 hour with a heating rate of 10 °C/min in a resistive furnace under argon atmosphere for green samples compacted in 200 and 400 MPa; the second sintering was performed on dilatometer in solid phase at 1300 °C for green sample compacted in 200 MPa, another sintering also was performed on dilatometer, this time in liquid phase at 1550 °C for green samples compacted in 200 and 400 MPa, with the same parameters used in resistive furnace. The raw materials were characterized by X – ray diffraction (XRD), X – ray fluorescence (XRF), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and laser particlemeter. The sintered samples were subjected to microhardness testing. The results showed that high energy milling achieved to the objectives regarding the particle size and the dispersion of composite phases. However, the hardness did not achieve to significant results, this is an indication that the composite has low fracture toughness.