To educate or not to educate: is that the question?

Includes bibliography

The role of education in relation to employment problems

Includes bibliography

Development and education in rural areas

Includes bibliography

Pedagogical model and school failure

Includes bibliography

Styles of development and education: a stocktaking of myths, prescriptions and potentialities

Includes bibliography

Education and culture: a political perspective: hypotheses on the importance of education for development

Includes bibliography

Effect of air-particle abrasion protocols on the biaxial flexural strength, surface characteristics and phase transformation of zirconia after cyclic loading

This study evaluated the effect of air-particle abrasion protocols on the biaxial flexural strength, surface characteristics and phase transformation of zirconia after cyclic loading. Disc-shaped zirconia specimens (Ø: 15mm, thickness: 1.2mm) (N=32) were submitted to one of the air-particle abrasion protocols (n=8 per group): (a) 50μm Al2O3 particles, (b) 110μm Al2O3 particles coated with silica (Rocatec Plus), (c) 30μm Al2O3 particles coated with silica (CoJet Sand) for 20s at 2.8bar pressure. Control group received no air-abrasion. All specimens were initially cyclic loaded (×20,000, 50N, 1Hz) in water at 37°C and then subjected to biaxial flexural strength testing where the conditioned surface was under tension. Zirconia surfaces were characterized and roughness was measured with 3D surface profilometer. Phase transformation from tetragonal to monoclinic was determined by Raman spectroscopy. The relative amount of transformed monoclinic zirconia (FM) and transformed zone depth (TZD) were measured using XRD. The data (MPa) were analyzed using ANOVA, Tukey's tests and Weibull modulus (m) were calculated for each group (95% CI). The biaxial flexural strength (MPa) of CoJet treated group (1266.3±158A) was not significantly different than that of Rocatec Plus group (1179±216.4A,B) but was significantly higher than the other groups (Control: 942.3±74.6C; 50μm Al2O3: 915.2±185.7B,C). Weibull modulus was higher for control (m=13.79) than those of other groups (m=4.95, m=5.64, m=9.13 for group a, b and c, respectively). Surface roughness (Ra) was the highest with 50μm Al2O3 (0.261μm) than those of other groups (0.15-0.195μm). After all air-abrasion protocols, FM increased (15.02%-19.25%) compared to control group (11.12%). TZD also showed increase after air-abrasion protocols (0.83-1.07μm) compared to control group (0.59μm). Air-abrasion protocols increased the roughness and monoclinic phase but in turn abrasion with 30μm Al2O3 particles coated with silica has increased the biaxial flexural strength of the tested zirconia. © 2013 Elsevier Ltd.

Micro-raman spectroscopic characterization of a CR-39 detector

Characterization by micro-Raman spectroscopy of polymeric materials used as nuclear track detectors reveals physico-chemical and morphological information on the material's molecular structure. In this work, the nuclear track detector poly(allyl diglycol carbonate), or Columbia Resin 39 (CR-39), was characterized according to the fluence of alpha particles produced by a 226Ra source and chemical etching time. Therefore, damage of the CR-39 chemical structure due to the alpha-particle interaction with the detector was analyzed at the molecular level. It was observed that the ionization and molecular excitation of the CR-39 after the irradiation process entail cleavage of chemical bonds and formation of latent track. In addition, after the chemical etching, there is also loss of polymer structure, leading to the decrease of the group density C-O-C (∼888 cm-1), CH=CH (∼960 cm -1), C-O (∼1110 cm-1), C-O-C (∼1240 cm -1), C-O (∼1290 cm-1), C-O (∼1741 cm -1), -CH2- (∼2910 cm-1), and the main band -CH2- (∼2950 cm-1). The analyses performed after irradiation and chemical etching led to a better understanding of the CR-39 molecular structure and better comprehension of the process of the formation of the track, which is related to chemical etching kinetics. Copyright © 2013 Society for Applied Spectroscopy.

Informe del Noveno Período de Sesiones del Comité de Expertos Gubernamentales de Alto Nivel, dedicado a la ciencia y la tecnología para el desarrollo = Report of the Ninth Session of the Committee of High-Level Government Experts: science and technology for development

Presenta la organizacion de los trabajos y el resumen de los debates de la reunion del CEGAN, realizada en Montevideo entre el 23 y el 24 de enero de 1984 en la cual se trataron la evaluacion de la aplicacion del Programa de Accion de Viena sobre ciencia y tecnologia para el desarrollo en America Latina, las propuestas de medidas y acciones futuras y las recomendaciones a los organos internacionales y regionales.

O revelar da paixão: as relações estabelecidas entre coreógrafo, bailarinos e obra no processo de criação do Pas de Deux de Bachiana n.1

Pós-graduação em Artes - IA

Empresas líderes en desarrollo, aplicación y difusión de tecnologías ambientalmente racionales en América Latina: los casos de desarrollo del biodigestor de flujo ascendente y del sistema de eliminación de fluoruros en aguas de abastecimiento público por la Compañia de Tecnología de Saneamiento Ambiental - CETESB, Sao Paulo, Brasil

Incluye Bibliografía

Los recursos naturales en las estrategias de transformación productiva

Incluye Bibliografía

Entre o porão e sótão: espaços de formação em The wives of Bath, de Susan Swan

Pós-graduação em Letras - FCLAS

Análise do exercício de agachamento utilizando o método de Kane

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)