231 research outputs found

    Amides do not always work: observation of guest binding in an amide-functionalised porous host

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    An amide-functionalised metal organic frame-work (MOF) material, MFM-136, shows a high CO2 uptake of 12.6 mmol g-1 at 20 bar and 298 K. MFM-136 is the first example of acylamide pyrimidyl isophthalate MOF without open metal sites, and thus provides a unique platform to study guest bind-ing, particularly the role of free amides. Neutron diffraction reveals that, surprisingly, there is no direct binding between the adsorbed CO2/CH4 molecules and the pendant amide group in the pore. This observation has been confirmed un-ambiguously by inelastic neutron spectroscopy. This suggests that introduction of functional groups solely may not neces-sarily induce specific guest-host binding in porous materials, but it is a combination of pore size, geometry, and functional group that leads to enhanced gas adsorption properties

    Different paths to the modern state in Europe: the interaction between domestic political economy and interstate competition

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    Theoretical work on state formation and capacity has focused mostly on early modern Europe and on the experience of western European states during this period. While a number of European states monopolized domestic tax collection and achieved gains in state capacity during the early modern era, for others revenues stagnated or even declined, and these variations motivated alternative hypotheses for determinants of fiscal and state capacity. In this study we test the basic hypotheses in the existing literature making use of the large date set we have compiled for all of the leading states across the continent. We find strong empirical support for two prevailing threads in the literature, arguing respectively that interstate wars and changes in economic structure towards an urbanized economy had positive fiscal impact. Regarding the main point of contention in the theoretical literature, whether it was representative or authoritarian political regimes that facilitated the gains in fiscal capacity, we do not find conclusive evidence that one performed better than the other. Instead, the empirical evidence we have gathered lends supports to the hypothesis that when under pressure of war, the fiscal performance of representative regimes was better in the more urbanized-commercial economies and the fiscal performance of authoritarian regimes was better in rural-agrarian economie
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