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61.
Experimental investigation of carbon dioxide trapping due to capillary retention in saline aquifers
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Capillary trapping is a physical mechanism by which carbon dioxide (CO2) is naturally immobilized in the pore spaces of aquifer rocks during geologic carbon sequestration operations, and thus a key aspect of estimating geologic storage potential. Here, we studied capillary trapping of supercritical carbon dioxide (scCO2), and the effect of initial scCO2 saturation and flow rate on the storage/trapping potential of Berea sandstone. We performed two‐phase, scCO2‐brine displacements in two samples, each subject to four sequential drainage–imbibition core‐flooding cycles to quantify end‐point saturations of scCO2 with the aid of micro‐ and macro‐computed tomography imaging. From these experiments, we found that between 51% and 75% of the initial CO2 injected can be left behind after the brine injection. We also observed that the initial scCO2 saturation influenced the residual scCO2 saturation to a greater extent than the rate of brine injection under the experimental conditions examined. In spite of differences in the experimental conditions tested, as well as those reported in the literature, initial and residual saturations were found to follow a consistent relationship. 相似文献
62.
Cheng Lei Meng Hui Zhang Shi Qiang Fang 《International Journal of Architectural Heritage》2015,9(8):942-948
Ancient mortars played a crucial role in the construction of historical architectures due to their physical and chemical compatibility with traditional building materials such as stones and bricks. Therefore, the analysis and optimization of the ancient mortar formula are significant in the restoration and preservation of historical sites. In this work, 20 mortar samples selected from five ancient stone pagodas in Zhejiang Province, China, were analyzed. The results showed that mud, lime-soil mortar, lime-sand mortar, and lime-gypsum mortar were used as binders in these pagodas. The Ca(OH)2/aggregate ratio ranging from 0.3 to 2.7 was usually used to prepare lime mortar. Protein and polysaccharide were also found in some samples. 相似文献
63.
Cristina Costa António Arêde Aníbal Costa Elsa Caetano Álvaro Cunha Filipe Magalhães 《International Journal of Architectural Heritage》2015,9(7):760-774
This article aims at presenting and discussing the strategies for updating the finite element numerical modeling of stone masonry arch bridges using operational modal analysis. The study comprehended three bridges: two old ones, the St. Lázaro and the Lagoncinha bridges, and a recently constructed bridge in Vila Fria, Portugal. Updating of the bridge models is performed by comparing the numerical and experimental modal parameters. Three-dimensional detailed numerical models are used to perform modal analysis of the bridges. Experimental modal identification of the bridges is based on the measurement of their acceleration responses during normal operation. The assigned material properties are also based on available results obtained from in situ and laboratory tests and on the results of visual inspection and historical research carried out for both old bridges. 相似文献
64.
‘They have to abide by our laws … and stuff’: ethnonationalism masquerading as civic nationalism
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The long established distinction between civic nationalism and ethnonationalism is useful heuristically to understand different dimensions of nationalism and perhaps track a movement from ethnic forms to civic allegiances, though some have challenged its empirical veracity and others question the normative implications of such a distinction. This paper demonstrates the ways in which the two are elided in everyday discourses about migrants in Australia. We argue suspicion of cultural difference, identified more than three decades ago as the new racism, has given way to talk of the need for migrants to ‘follow the law’. This serves rhetorically to reinforce the notion that migrants, often implied to overlap with the category ‘Muslims’, are insisting on breaking the law and/or changing it and are therefore culturally incompatible with a modern liberal democracy. We argue that since ethnic nationalism, like racism, is out of favour normatively, ethnic nationalist arguments are now superficially concealed beneath the acceptable language of civic nationalism. The manner in which this occurs is mapped discursively using data from a corpus of twenty seven focus groups conducted around Australia. 相似文献
65.
Reaching across: institutional barriers to cross‐ethnic parties in post‐conflict societies and the case of Northern Ireland
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Cera Murtagh 《Nations & Nationalism》2015,21(3):544-565
This paper investigates the paradox in post‐conflict societies of continued marginality of cross‐ethnic parties despite significant convergence in public attitudes and identities. In so doing, it examines the argument that parties that attempt to reach across the divide are constrained by consocational institutions designed to accommodate rival identities in such environments. The paper explores this puzzle in the context of Northern Ireland, drawing upon qualitative evidence from elite interviews and focus groups collected in 2012 and 2013. It concludes that cross‐community parties operating in the region do encounter formal institutional barriers, but that such barriers only partially explain the phenomenon and an interplay between formal and informal constraints underlies their position of relatively limited electoral success. 相似文献
66.
NOEL CASTREE 《Geographical Research》2015,53(1):1-15
Initiated by geoscientists, the growing debate about the Anthropocene, ‘planetary boundaries’ and global ‘tipping points’ is a significant opportunity for geographers to reconfigure two things: one is the internal relationships among their discipline's many and varied perspectives (topical, philosophical, and methodological) on the real; the other the discipline's actual and perceived contributions to important issues in the wider society. Yet, without concerted effort and struggle, the opportunity is likely to be used in a ‘safe’ and rather predictable way by only a sub‐set of human‐environment geographers. The socio‐environmental challenges of a post‐Holocene world invite old narratives about Geography's holistic intellectual contributions to be reprised in the present. These narratives speak well to many geoscientists, social scientists, and decision‐makers outside Geography. However, they risk perpetuating an emaciated conception of reality wherein Earth systems and social systems are seen as knowable and manageable if the ‘right’ ensemble of expertise is achieved. I argue that we need to get out from under the shadow of these long‐standing narratives. Using suggestive examples, I make the case for forms of inquiry across the human‐physical ‘divide’ that eschew ontological monism and that serve to reveal the many legitimate cognitive, moral, and aesthetic framings of Earth present and future. Geography is unusual in that the potential for these forms of inquiry to become normalised is high compared with other subjects. This potential will only be taken advantage of if certain human‐environment geographers unaccustomed to engaging the world of geoscience and environmental policy change their modus operandi. 相似文献
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