Argilominerais de Coberturas Sedimentares Cenozóicas do Centro-leste do Estado de São Paulo

Clay mineral analysis contributed to the mineralogical characterization and stratigraphic setting of continental Cenozoic deposits of central-eastern portion of São Paulo State, southeastern Brazil. These deposits, often thin and discontinuous, comprise the Itaqueri Formation (Cretaceous-Paleogene), Rio Claro Formation (Pliocene) and associated Neocenozoic deposits. X-ray diffractometry provided mineralogical and semiquantitative constitution of clays, while scanning electron microscopy (SEM) provided details about mineralogical constitution, packing of microscopic grains and nature (detrital or diagenetic) of clays. These results supported interpretations about paleoenvironmental conditions during sedimentation, revealing possible links between changing climates (dry or humid) and correlative Cenozoic deposits in southeastern Brazil. In addition, SEM images showed microstructures which influence on geotechnical behaviour (erosion and collapse phenomena) of sedimentary materials.

Comparación de tres métodos para estimar estabilidad del rendimiento en nueve variedades de algodón

With the purpose of selecting and recommending promissory cultivars of cotton, Gossypium hirsutum (L) with high yield potential and stability, for crop areas in Venezuela, the yield (seed included) of nine cotton varieties was evaluated. The data from the 1995-96 and 1996-97 cycles was used. The experimental design was a randomized completed block design with four repetitions on twelve environments. Parameters of stability offered by the methods of Eberhart and Russell, (1966), Cruz et al. (1989) and the AMMI model were estimated and compared to determine the best method or combination. There was no coincidence between the best yield varieties, Unellez-2 and the commercial variety Delta Pine 16, in relation to stability criteria. According to Eberhart and Russell, these were classified as stable, while according to Cruz et al. they were adaptive to favorable environments and according to AMMI they were unstable with high interaction,.Of the three methods studied, the AMMI model allowed associating the response of high yield varieties to specific environments, gave more information and was easier to interpret.

Informe preliminar del segundo estudio nacional de consumo de drogas en Chile, y comparación de los principales resultados con el primer estudio nacional, años 1994 y 1996

Incluye Bibliografía

Ronda de 2011 del Programa de Comparación Internacional (PCI) en América Latina y Caribe

Incluye Bibliografía

Comparación entre encuestas demográficas prospectivas y retrospectivas para estimar niveles y diferenciales de mortalidad: la experiencia del CELADE

Compara los niveles estimados de mortalidad derivados de las encuestas demograficas prospectivas y retrospectivas realizadas en Honduras, Panama y Peru.

Viabilidade de aplicação das coberturas argilosas da região de Alfenas na indústra cerâmica

The region of Alfenas, in the state of Minas Gerais, Brazil, is predominantly constituted of Pre-Cambrian rocks with well developed alteration profiles in association with colluvial and alluvial sediments. No study to date has examined in detail its potential use in the ceramic industry. The scarce knowledge of its mineralogical and technological properties limits its value and consequently its industrial use. Until now, these clay materials have been used in a rudimental manner, in small scale in the fabrication of red tiles. The present study aimed at analyzing these clays mineralogically (X-ray diffraction), chemically (major and minor elements by X-ray fluorescence and organic carbon analysis) and technologically (pressing granulometric distribution; mechanical resistence; water absorption, apparent porosity; linear firing shrinkage; color of firing and others) in order to better understand the raw material and develop adequate technological applications. The best results of ceramic properties were the samples with higher organic content (more plastic clays) and higher values of Al2O3 (kaolinite and gibbsite) and Fe2O3 as well lower SiO2 content and finer grain size which contribute to a better sinterization.

Metodología para la comparación de los gastos militares

Incluye Bibliografía

Resultados del Programa de Comparación Internacional para América del Sur

Incluye Bibliografía

Papel de la pequeña y mediana empresa (PME) en la estructura industrial de los países de América Latina: una comparación con el caso de Italia

Incluye Bibliografía

Indicadores de los objetivos de desarrollo del milenio en América Latina y el Caribe: una comparación entre datos nacionales e internacionales

Incluye Bibliografía

Comparación del Sistema de Cuentas Nacionales 1993 y el Sistema de Cuentas de Salud

Incluye Bibliografía

Comparación de la dinámica e impactos de los choques financieros y de términos del intercambio en América Latina en el período 1980-2006

Incluye Bibliografía