989 resultados para 552 Petrología
Resumo:
Gran parte de la República de El Salvador está cubierta por productos de explosiones volcánicas, originarias de los diferentes volcanes activos y apagados, estos depósitos volcánicos no son solamente testigos importantes de la actividad volcánica, sino también representan un factor determinativo del paisaje Salvadoreño y son como rocas madres de la cual se origina el suelo de importancia básica para la agricultura. En la Carretera del Norte entre Villa Delgado y Apopa, hay depósitos de cenizas volcánicas en buena exposición por la construcción de la carretera, en los paredones de los cortes se observa la sucesión de 4 a 5 capas distintas de materiales diferentes, unas encimas de las otras. Estos estratos están separados por horizontes de descomposición, es decir de tierras negras. Fue objeto de este estudio reconocer la composición de dichas capas y aquella de las resultantes tierras descompuestas. Para tal fin se tomo 10 muestras de un perfil situado a unos 400 metros al norte del tercer cruce ferroviario al norte de Villa Delgado, en la propia carretera.
Resumo:
En los alrededores de la ciudad de San Salvador abundan cenizas blancas de pómez, la llamada “Tierra blanca”, resultantes de erupciones del volcán El Boquerón. Los horizontes de descomposición permiten estudiar la estratificación de las cenizas de pómez tal como se detalladamente en vista de 3 perfiles. El contenido mineral y el análisis químico indican un magma acido, rico en cal. Una investigación de las distintas capaz de ceniza, respecto a la distribución de granos y minerales, da a conocer diferencias cuantitativas apropiadas para la comprobación de los perfiles. En la descomposición de las cenizas el vidrio se transforma de preferencia en metahaloisa los demás minerales se muestran bastante estables, a excepción de los piroxenes. Por consiguiente la descomposición se efectúa solamente con pocas transformaciones químicas, la descomposición de depósitos de edad conocida, parece realizarse muy lentamente bajo las condiciones climáticas actuales en El Salvador. De eso resultan algunos datos para la historia de las expulsiones del volcán El Boquerón que muestra una actividad muy larga con largos tiempos de calma y periodos breves de erupciones violentas.
Resumo:
Dia de movimentação intensa na Constituinte. No começo da tarde, trabalhadores rurais ocuparam o corredor que dá acesso ao Plenário da Constituinte e saudaram cada constituinte com músicas e palmas em favor da Reforma Agrária. Nos gabinetes, a preocupação era mobilizar os constituintes para a votação. O PFL, que não apresentou emenda, decidiu pedir destaque e votar em separado o parágrafo que permite a desapropriação de terras produtivas, que não cumprirem a sua função social. O PMDB colocou em dúvida se o regimento permite apresentação de destaque, quando há um novo texto para votação. Ao chegar ao Plenário, para presidir a votação da Reforma Agrária, Ulysses Guimarães, afirmou que o Regimento permite o destaque. O texto do relator Bernardo Cabral foi colocado em votação. O texto foi aprovado em votação. A seguir foi votado o destaque em separado que suprime a questão da desapropriação da propriedade produtiva que não cumpre a função social.
Resumo:
GD 552 is a high proper motion star with the strong, double-peaked emission lines characteristic of the dwarf nova class of cataclysmic variable (CV) star, and yet no outburst has been detected during the past 12yr of monitoring. We present spectroscopy taken with the aim of detecting emission from the mass donor in this system. We fail to do so at a level which allows us to rule out the presence of a near-main-sequence star donor. Given GD 552's orbital period of 103 min, this suggests that it is either a system that has evolved through the ~80-minute orbital period minimum of CV stars and now has a brown dwarf mass donor, or that has formed with a brown dwarf donor in the first place. This model explains the low observed orbital velocity of the white dwarf and GD 552's low luminosity. It is also consistent with the absence of outbursts from the system.
Resumo:
GD 552 is a cataclysmic binary which was previously believed to be composed of an M-star and a white dwarf, the latter having an extreme mass of 1.4 solar masses. In a recent paper we showed that this is not compatible with new observational evidence and presented an alternative model in which the white dwarf has a typical mass and the companion is a brown dwarf, making the system a likely member of the elusive group of CVs which have already evolved through minimum orbital period. Here we present additional spectroscopical evidence supporting this conclusion by means of skew mapping.
Resumo:
In a scenario of increasing life expectancy worldwide, it is mandatory to identify the characteristics of a healthy aging phenotype, including survival predictors, and to disentangle those related to environment/lifestyle versus those related to familiarity/genetics. To this aim we comprehensively characterised a cohort of 1,160 Italian subjects of 90 years and over (90+, mean age 93 years; age range 90-106 years) followed for 6 years survival, belonging to 552 sib-ships (familiar longevity) recruited (2005-2008) within the EU-funded GEHA project in three Italian geographic areas (Northern, Central and Southern Italy) different for urban/rural and socio-economical characteristics. On the whole, the following factors emerged as significant predictors of survival after 90 years of age: absence of cognitive impairment and physical disability, high hand grip strength scores and body mass index (BMI) values, "excellent/good" self-reported health, high haemoglobin and total cholesterol levels and low creatinine levels. These parameters, excluding BMI values, were also significantly associated within sib-ships, suggesting a strong familial/genetic component. Geographical micro-heterogeneity of survival predictors emerged, such as functional and physical status being more important in Southern than in Central and Northern Italy. In conclusion, we identified modifiable survival predictors related to specific domains, whose role and importance vary according to the geographic area considered and which can help in interpreting the genetic results obtained by the GEHA project, whose major aim is the comprehensive evaluation of phenotypic and genetic data.
Resumo:
The health status of the oldest old, the fastest increasing population segment worldwide, progressively becomes more heterogeneous, and this peculiarity represents a major obstacle to their classification. We compared the effectiveness of four previously proposed criteria (Franceschi et al., 2000; Evert et al., 2003; Gondo et al., 2006; Andersen-Ranberg et al., 2001) in 1160 phenotypically fully characterized Italian siblings of 90 years of age and older (90+, mean age: 93 years; age range: 90–106 years) belonging to 552 sib-ships, recruited in Northern, Central and Southern Italy within the EU-funded project GEHA, followed for a six-year-survival. Main findings were: (i) ‘‘healthy’’ subjects varied within a large range, i.e. 5.2% (Gondo), 8.7% (Evert), 17.7% (Franceschi), and 28.5% (Andersen-Ranberg); (ii) Central Italy subjects showed better health than those from Northern and Southern Italy; (iii) mortality risk was correlated with health status independently of geographical areas; and (iv) 90+ males, although fewer in number, were healthier than females, but with no survival advantage. In conclusion, we identified a modified version of Andersen-Ranberg criteria, based on the concomitant assessment of two basic domains (cognitive, SMMSE; physical, ADL), called ‘‘Simple Model of Functional Status’’ (SMFS), as the most effective proxy to distinguish healthy from not-healthy subjects. This model showed that health status was correlated within sib-ships, suggesting a familial/genetic component.
Resumo:
Se analiza la relación entre Geografía y Petrología y la importancia de la iniciación en esta materia no solo desde el punto de vista geográfico, sino por el interés que las rocas despiertan en los niños. Su enseñanza debe acostumbrar al niño a observar, diferenciar lo fundamental de lo secundario, a expresar ideas claras y con orden , es decir, la Petrología puede ir formando el espíritu científico del niño a partir de su curiosidad natural. Recomienda el método de enseñanza que parte de los datos obtenidos por la observación o la experimentación para, por inducción, llegar a las leyes de la Naturaleza. Considera la Petrología parte de las Ciencias de la Naturaleza, y confecciona un plan de trabajo para segundo curso de Perfeccionamiento y el curso de Iniciación profesional.