886 resultados para Explosion de Coulomb
Resumo:
An inexpensive device which is easily operated to accurately measure the Coulomb parameters of the soil. The Coulomb parameters are used in Coulomb's equation to calculate the shearing stresses along a failure surface of the soil. The device includes an instrument to test soil shear strength to which several weights have been added. To obtain the Coulomb parameters, the instrument is placed on the soil to be tested and weights are incrementally added to it. The instrument is rotated at each weight increment and the shearing stresses are read from its calibrated dial. The stresses are plotted on a graph from which the Coulomb parameters are determined. The shearing stress of the soil with any known force applied to it can then be determined.
Resumo:
Las diversas manifestaciones de la cultura (entre ellas los fenómenos llamados «comunicacionales») avanzan, nacen, se transforman y perduran a través de dos dinámicas entre contradictorias y complementarias: la transformación y la permanencia. Dichas dinámicas atraviesan las vanadas características de los fenómenos culturales; la autonomía relativa con respecto a la estructura económica, el cambio gradual, la explosión, la memoria, las vanguardias, las rupturas, la tradición, los géneros, etc. Autores de la escuela semiótica de Tartu, como luri Lotman, han estudiado cómo funcionan estos procesos propios de la esfera semiocultural, y han investigado los mecanismos específicos de los textos culturales que los hacen, a la misma vez, textos de la memoria y de la renovación. Este artículo busca describir sintéticamente dichos procesos (por momentos contradictorios) y mostrar su «funcionamiento» en la murga, un género musical-teatral carnavalero de la cultura popular uruguaya.
Resumo:
El ritmo de crecimiento de la población mundial es observado en general desde una perspectiva negativa, basada en argumentaciones económicas o ecológicas. El temor a la sobrepoblación, que comenzó a difundirse cuando la humanidad alcanzó los mil millones, con frecuencia fue potenciado hasta la categoría de alarmismo, especialmente en ocasión de la incorporación de mil millones más, y desde entonces se traduce en el propósito de frenar el crecimiento, generalmente con medidas antinatalistas. A principios del siglo XXI, ante el fenómeno de la reducción planetaria de las tasas de crecimiento, se perfila un nuevo alarmismo por infrapoblación, que coexiste sin embargo con un alarmismo por sobrepoblación.
Resumo:
yResults of 13 field investigations between 1966 and 1990 of the southwestern to eastern margin of Kötlujökull and its proglacial area are summarized with respect to sandar and their formation. Generally, the results are based on sedimentological examinations in the field and laboratory, on analyses of aerial photographs, and investigations of the glacier slope. The methods permitted a more detailed reconstruction of sandar evolution in the proglacial area of Kötlujökull since 1945, of tendencies in development and of single data going back until the last decades of the 19th century. Accordingly, there existed special periods of "flachsander"-formations with raised coarsegrained "sanderwurzels" resultant from the outbreak of subglacial meltwater tunneloutlets and other periods with "hochsander-"formations by supraglacial drainage. At present the belts of hochsanders in front of the glacier come up to more than 4 m in thickness and 1000 m in width, therefore containing perhaps more sediment direct in front of Kötlujökull than the old belts of flachsanderwurzels. In one case the explosion-like subglacial meltwater outburst combined with the genesis of a sanderwurzel could be observed for a time and is thoroughly discussed. The event is referred to the outburst of a sub- to inglacial meltwater body being under extreme hydrostatic press ures which is combined with the genesis of a new subglacial tunneloutlet as a new flachsander. Often these outbursts led to the destruction of a morainic belt more than 1000 m in width. Presumably the whole event was finished in not more than a few days. In addition to a characteristic pear-shaped form and water-moved stones up to diameters of 1 m the wurzels possess a single "main-channel" with rectangular cross-sections as far as 4 m deep and 50 m wide just as small flat channels resembling fish bones in connection with the main channel. Presumably, they have been active only in the last stage of wurzel formation. With regard to the subglacial tunnel gates long-living L-meltwater outlets are distinguished from short-living K-meltwater outlets. These are always combined with a raised coarse-grained sanderwurzel, but its meltwater discharge is generally decreasing and ceases after some years, whereas the discharge of L-meltwater outlets continues unchanged for long times (except seasonal differences). The material of flachsanders is preponderantly composed of mugearitic and andesitic cobble extending at least for some kilometres from the glacier margin, whereas the hochsanders correspond to medium to coarse sands without clay and without alternations into the direction of flow. The hochsander fans are covered with small braidet channels. Their sedimentary structures are determined by the short time changing of supraglacial meltwater discharge and the upper flow regime combined with the development of antidunes, which rule the channel-flows during the main activity periods in summer. Unlike the subglacial drainage the supraglacial drainage led to only weak effects of erosion on the glacier foreland. So the hochsanders refilled depressions of morainic areas or grew up on older flachsanderwurzels. Whereas all large flachsanders developed in front of approximate stationary glacier margins, the evolution of coherent belts of hochsanders were combined with progressive glacier fronts. On the other hand, there was obviously no evolution at all of large sandar in front of back-melting margins of Kötlujökull. Based on examinations of the glacier surface and on analyses of aerial photographs the different types of sandar are referred to different structures of the glacier snout. Finally chances of surviving of sandar in the proglacial area of Kötlujökull are shortly discussed just as the possibility of an application of the Islandic research results on Pleistocene sandar in northern Germany.
Resumo:
Entre 1956 y 1961 Severo Sarduy publicó una importante cantidad de textos sobre literatura, plástica y teatro cubano en el Diario Libre, Lunes de Revolución, Nueva Revista Cubana, Mañana libre y Combate 13 de Marzo. Participó de la explosión que caracterizó a la prensa literaria cubana a partir de la Revolución y se inscribió en las filas de los intelectuales que trabajaron en favor de ella. Entregado a sus labores de periodista plástico, un muy joven Sarduy entrevista al famoso pintor Mariano Rodríguez (1912-1990), co-fundador junto al escultor Alfredo Lozano (1913-1997) y a los escritores José Lezama Lima (1910-1976) y José Rodríguez Feo (1920-1993) de la revista Orígenes. Esta entrevista fue publicada en La Habana el 12 de octubre de 1959 y en ella se exponen juicios estéticos y políticos sobre el régimen de visibilidad cultural del arte cubano en el nuevo orden social. Cabe destacar que, a pesar de la ruptura que se produjo entre los editores de Orígenes, Mariano Rodríguez se convirtió en el creador del "Eolo" que sirvió de ícono a la postrera revista Ciclón (1955). Por lo tanto, presentamos un recorrido por dicha entrevista profundizando el breve pero significativo vínculo-desencuentro sucedido entre ambos
Resumo:
El presente artículo analiza las particularidades del proceso de trasferencia genérica de la novela gótica inglesa a la literatura española en el período de entresiglos (1788-1833), que quedan fijadas en una fase de traducción-adaptación especialmente intensa que tuvo lugar en las primeras décadas del siglo XIX, previa a la explosión que coincidirá con los albores del movimiento romántico y que supondrá el ocaso definitivo del género dentro de nuestras fronteras
Resumo:
Entre 1956 y 1961 Severo Sarduy publicó una importante cantidad de textos sobre literatura, plástica y teatro cubano en el Diario Libre, Lunes de Revolución, Nueva Revista Cubana, Mañana libre y Combate 13 de Marzo. Participó de la explosión que caracterizó a la prensa literaria cubana a partir de la Revolución y se inscribió en las filas de los intelectuales que trabajaron en favor de ella. Entregado a sus labores de periodista plástico, un muy joven Sarduy entrevista al famoso pintor Mariano Rodríguez (1912-1990), co-fundador junto al escultor Alfredo Lozano (1913-1997) y a los escritores José Lezama Lima (1910-1976) y José Rodríguez Feo (1920-1993) de la revista Orígenes. Esta entrevista fue publicada en La Habana el 12 de octubre de 1959 y en ella se exponen juicios estéticos y políticos sobre el régimen de visibilidad cultural del arte cubano en el nuevo orden social. Cabe destacar que, a pesar de la ruptura que se produjo entre los editores de Orígenes, Mariano Rodríguez se convirtió en el creador del "Eolo" que sirvió de ícono a la postrera revista Ciclón (1955). Por lo tanto, presentamos un recorrido por dicha entrevista profundizando el breve pero significativo vínculo-desencuentro sucedido entre ambos
Resumo:
El presente artículo analiza las particularidades del proceso de trasferencia genérica de la novela gótica inglesa a la literatura española en el período de entresiglos (1788-1833), que quedan fijadas en una fase de traducción-adaptación especialmente intensa que tuvo lugar en las primeras décadas del siglo XIX, previa a la explosión que coincidirá con los albores del movimiento romántico y que supondrá el ocaso definitivo del género dentro de nuestras fronteras
Resumo:
The study was inspired by information on Paleozoic andesites, dacites, and diabases on the Belkovsky Island in the 1974 geological survey reports used to reconstruct tectonic evolution of the continental block comprising the New Siberian Islands and the bordering shelf. We did not find felsic volcanics or Middle Paleozoic intrusions in the studied area of the island. Igneous rocks are mafic subvolcanic intrusions including dikes, randomly shaped bodies, explosion breccias, and peperites. They belong to the tholeiitic series and are similar to Siberian traps in petrography and trace-element compositions, with high LREE and LILE and prominent Nb negative anomalies. The island arc affinity is due to continental crust contamination of mantle magma and its long evolution in chambers at different depths. K-Ar biotite age (252+/-5 Ma) of magmatism indicates that it was coeval to the main stage of trap magmatism in the Siberian craton at the Permian-Triassic boundary. The terrane including the New Siberian Islands occurred on the periphery of the Siberian trap province where magmatism acted in rifting environment. Magma intruded into semiliquid wet sediments at shallow depths shortly after their deposition. Therefore, the exposed Paleozoic section in Belkovsky Island may include Permian or possibly Lower Triassic sediments of younger ages than it was believed earlier.
Resumo:
Entre 1956 y 1961 Severo Sarduy publicó una importante cantidad de textos sobre literatura, plástica y teatro cubano en el Diario Libre, Lunes de Revolución, Nueva Revista Cubana, Mañana libre y Combate 13 de Marzo. Participó de la explosión que caracterizó a la prensa literaria cubana a partir de la Revolución y se inscribió en las filas de los intelectuales que trabajaron en favor de ella. Entregado a sus labores de periodista plástico, un muy joven Sarduy entrevista al famoso pintor Mariano Rodríguez (1912-1990), co-fundador junto al escultor Alfredo Lozano (1913-1997) y a los escritores José Lezama Lima (1910-1976) y José Rodríguez Feo (1920-1993) de la revista Orígenes. Esta entrevista fue publicada en La Habana el 12 de octubre de 1959 y en ella se exponen juicios estéticos y políticos sobre el régimen de visibilidad cultural del arte cubano en el nuevo orden social. Cabe destacar que, a pesar de la ruptura que se produjo entre los editores de Orígenes, Mariano Rodríguez se convirtió en el creador del "Eolo" que sirvió de ícono a la postrera revista Ciclón (1955). Por lo tanto, presentamos un recorrido por dicha entrevista profundizando el breve pero significativo vínculo-desencuentro sucedido entre ambos
Resumo:
El presente artículo analiza las particularidades del proceso de trasferencia genérica de la novela gótica inglesa a la literatura española en el período de entresiglos (1788-1833), que quedan fijadas en una fase de traducción-adaptación especialmente intensa que tuvo lugar en las primeras décadas del siglo XIX, previa a la explosión que coincidirá con los albores del movimiento romántico y que supondrá el ocaso definitivo del género dentro de nuestras fronteras
Resumo:
Two silicate-rich dust layers were found in the Dome Fuji ice core in East Antarctica, at Marine Isotope Stages 12 and 13. Morphologies, textures, and chemical compositions of constituent particles reveal that they are high-temperature melting products and are of extraterrestrial origin. Because similar layers were found ~2000 km east of Dome Fuji, at EPICA (European Project for Ice Coring in Antarctica)-Dome C, particles must have rained down over a wide area 434 and 481 ka. The strewn fields occurred over an area of at least 3 × 10**6 km**2. Chemical compositions of constituent phases and oxygen isotopic composition of olivines suggest that the upper dust layer was produced by a high-temperature interaction between silicate-rich melt and water vapor due to an impact explosion or an aerial burst of a chondritic meteoroid on the inland East Antarctic ice sheet. An estimated total mass of the impactor, on the basis of particle flux and distribution area, is at least 3 × 10**9 kg. A possible parent material of the lower dust layer is a fragment of friable primitive asteroid or comet. A hypervelocity impact of asteroidal/cometary material on the upper atmosphere and an explosion might have produced aggregates of sub-µm to µm-sized spherules. Total mass of the parent material of the lower layer must exceed 1 × 10**9 kg. The two extraterrestrial horizons, each a few millimeters in thickness, represent regional or global meteoritic events not identified previously in the Southern Hemisphere.
Resumo:
Long-term evolution is thought to take opportunities that arise as a consequence of mass extinction (as argued, for example, by Gould, 2002) and the following biotic recovery, but there is absolutely no evidence for this being the case. However, our study shows that eutrophication by oceanic mixing also played a part in the enhancement of several evolutionary events amongst marine organisms, and these results could indicate that the rates of oceanic biodiversification may be slowed if upwelling becomes weakened by future global warming. This paper defines three distinct evolutionary events of resting spores of the marine diatom genus Chaetoceros, to reconstruct past upwelling through the analysis of several DSDP, ODP and land-based successions from the North, South and equatorial Pacific as well as the Atlantic Ocean during the past 40 million years. The Atlantic Chaetoceros Explosion (ACE) event occurred across the E/O boundary in the North Atlantic, and is characterized by resting spore diversification that occurred as a consequence of the onset of upwelling following changes in thermohaline circulation through global cooling in the early Oligocene. Pacific Chaetoceros Explosion events-1 and -2 (PACE-1 and PACE-2) are characterized by relatively higher occurrences of iron input following the Himalayan uplift and aridification at 8.5 Ma and ca. 2.5 Ma in the North Pacific region. These events not only enhanced the diversification and increased abundance of primary producers, including that of Chaetoceros, other diatoms and seaweeds, but also stimulated the evolution of zooplankton and larger predators, such as copepods and marine mammals, which ate these phytoplankton and plants. Current thinking suggests new evolutionary niches open up after a mass extinction, but our study finds that eutrophication can also stimulate evolutionary diversification. Moreover, in the opposite fashion, our results show that as thermohaline circulation abates, global warming progresses and the ocean surface becomes warmer, many marine organisms will be affected by the environmental degradation.