2 resultados para eruption sequestrum
em Aston University Research Archive
Resumo:
The 1950s and 1960s were a key moment in the development of postwar France. The period was one of rapid change, derived from post-World War II economic and social modernization; yet many traditional characteristics were retained. By analyzing the eruption of the new postwar world in the context of a France that was both modern and traditional, we can see how these worlds met and interacted, and how they set the scene for the turbulent 1960s and 70s. The examination of the development of mass culture in post-war France, undertaken in this volume, offers a valuable insight into the shifts that took place. By exploring stardom from the domain of cinema and other fields, represented here by famous figures such as Brigitte Bardot, Johnny Hallyday or Jean-Luc Godard, and less conventionally treated areas of enquiry (politics [de Gaulle], literary [Françoise Sagan], and intellectual culture [Lévi-Strauss]) the reader is provided with a broad understanding of the mechanisms of popularity and success, and their cultural, social, and political roles. The picture that emerges shows that many cultural articulations remained or became identifiably French; in spite of the American mass-culture origins of these social, economic, and cultural transformations.
Resumo:
It is well accepted that the climate impact of large explosive volcanic eruptions results from reduction of solar radiation following atmospheric conversion of magmatic SO emissions into HSO aerosols. Thus, understanding the fate of SO in the eruption plume is crucial for better assessing volcanic forcing of climate. Here we focus on the potential of tephra to interact with and remove SO gas from the eruptive plume. Scavenging of SO by tephra is generally assumed to be driven by in-plume, low-temperature reactions between HSO condensates and tephra particles. However, the importance of SO gas-tephra interaction above the dew point temperature of HSO (190-200°C) has never been constrained. Here we report the results of an experimental study where silicate glasses with representative volcanic compositions were exposed to SO in the temperature range 25-800°C. We show that above 600°C, the uptake of SO on glass exhibits optimal efficiency and emplaces surficial CaSO deposits. This reaction is sustained via Ca diffusion from the bulk to the surface of the glass particles. At 800°C, the diffusion coefficient for Ca in the glasses was in the range 10-10cms. We suggest that high temperature SO scavenging by glass-rich tephra proceeds by the same Ca diffusion-driven mechanism. Using a simple mathematical model, we estimated SO scavenging efficiencies at 800°C varying from