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The vault of Villaviciosa is one of the oldest existing examples of a true ribbed vault, and is the first of the crossed-arch type. Although its perfection suggests earlier trials, none has been found so far. It predates the oldest Romanesque ribbed vaults by more than a century. Notwithstanding its importance, no construction and structural study has ever been done; neither has an accurate survey been published. The purpose of this article is to fill this gap in the history of vault construction. A detailed survey has been made, providing the first accurate drawings of the vault. A close inspection of the extrados, completed with a visual inspection of interior damages, has allowed ascertaining the main construction features. With the geometry and the material data a structural analysis has been carried out. This analysis explains the fundamental structural behavior of the vault and throws new light into some historical issues; for example, it leads to discarding the widespread belief that the ribs are decorative: they are supporting the weight of the vault. 相似文献
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The debate about the complex issues of human development during the Middle to Upper Palaeolithic transition period (45–35 ka BP) has been hampered by concerns about the reliability of the radiocarbon dating method. Large 14C anomalies were postulated and radiocarbon dating was considered flawed. We show here that these issues are no longer relevant, because the large anomalies are artefacts beyond plausible physical limits for their magnitude. Previous inconsistencies between 14C radiocarbon datasets have been resolved, and a new radiocarbon calibration curve, IntCal09 (Reimer et al., 2009), was created. Improved procedures for bone collagen extraction and charcoal pre-treatment generally result in older ages, consistent with independently dated time markers. 相似文献
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The emotional geography of a mine closure: a study of the Ravensthorpe nickel mine in Western Australia 总被引:1,自引:0,他引:1
This paper engages with the literature on emotional geographies to report on a case study of the emotions surrounding the closure of a nickel mine in the shire of Ravensthorpe in the south-west of Western Australia in January 2009. Two themes from the affect-infused narratives of pre- and post-mine community members are outlined. The first, which challenges constructions of the closure as a purely industrial and economic concern, focuses on the intense feelings the shut-down invoked amongst participants. The second theme explores the way in which the owner of the mine, BHP Billiton, worked to suppress and regulate affective reactions to the closure and thus reveals the highly political nature of emotions. 相似文献
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