19,929 research outputs found

    Trade booms, trade busts and trade costs

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    What has driven trade booms and trade busts in the past and present? We derive a micro-founded measure of trade frictions from leading trade theories and use it to gauge the importance of bilateral trade costs in determining international trade flows. We construct a new balanced sample of bilateral trade flows for 130 country pairs across the Americas, Asia, Europe, and Oceania for the period from 1870 to 2000 and demonstrate an overriding role for declining trade costs in the pre-World War I trade boom. In contrast, for the post-World War II trade boom we identify changes in output as the dominant force. Finally, the entirety of the interwar trade bust is explained by increases in trade costs

    Completely bounded kernels

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    We introduce completely bounded kernels taking values in L(A,B) where A and B are C*-algebras. We show that if B is injective such kernels have a Kolmogorov decomposition precisely when they can be scaled to be completely contractive, and that this is automatic when the index set is countable.Comment: 22 pages. Fixed oversight in previous version. To appear in Acta Scientiarum Mathematicarum (Szeged) for the 100th anniversary of the birth of Bela Sz.-Nag

    Redefining Roles, Responsibilities, and Authority of School Leaders

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    Addresses the core challenges faced by principals and other school leaders faced with high expectations and accountability and inconsistent or limited support, based on current research literature in the field

    Trade costs in the first wave of Globalization

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    What drives globalization today and in the past? We employ a new micro-founded measure of bilateral trade costs based on a standard model of trade in differentiated goods to address this question. These trade costs gauge the difference between observed bilateral trade and frictionless trade. They comprise tariffs, transportation costs and all other factors that impede international trade but which are inherently difficult to observe. Trade costs fell on average by ten to Ăžfteen percent between 1870 and 1913. We also use this measure to decompose the growth of global trade over that period and Ăžnd that roughly 44 percent of the global trade boom can be explained by reductions in trade costs; the remaining 56 percent is attributable to economic expansion

    Tribological and mechanical comparison of sintered and hipped PM212: High temperature self-lubricating composites

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    Selected tribological, mechanical and thermophysical properties of two versions of PM212 (sintered and hot isostatically pressed, HIPped) are compared. PM212, a high temperature self-lubricating composite, contains 70 wt percent metal bonded chromium carbide, 15 wt percent CaF2/BaF2 eutectic and 15 wt percent silver. PM212 in the sintered form is about 80 percent dense and has previously been shown to have good tribological properties from room temperature to 850 C. Tribological results of a fully densified, HIPped version of PM212 are given. They are compared to sintered PM212. In addition, selected mechanical and thermophysical properties of both types of PM212 are discussed and related to the tribological similarities and differences between the two PM212 composites. In general, both composites display similar friction and wear properties. However, the fully dense PM212 HIPped composite exhibits slight lower friction and wear than sintered PM212. This may be attributed to its generally higher strength properties. The sintered version displays stable wear properties over a wide load range indicating its promise for use in a variety of applications. Based upon their properties, both the sintered and HIPped PM212 have potential as bearing and seal materials for advanced high temperature applications

    The effect of processing and compositional changes on the tribology of PM212 in air

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    The effects of processing and compositional variations on the tribological performance of PM212 were studied. PM212 is a self lubricating powder metallurgy composite, comprised of a wear resistant metal bonded chromium carbide matrix, containing the solid lubricants barium fluoride/calcium fluoride eutectic and silver. Several composites were formulated which had lubricant, matrix, and processing variations. Processing variations included sintering and hot isostatic pressing. Pins fabricated from the composites were slid against superalloys disks in a pin-on-disk tribometer to study the tribological properties. Several composites exhibited low friction and wear in sliding against a nickel based superalloy. The tribological performance by several different composites showed that the composition of PM212 can be altered without dramatically affecting performance

    Condorcet and I - A Fictional Conversation between Condorcet and Me: on the Outlines of an Historical View of the Progress of the Human Mind

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    The thesis’ main question is: Has the reality of Condorcet’s Outlines of an Historical View of the Progress of the Human Mind been realized with humanity becoming perfect, as Condorcet indicates? In answering that question, my thesis contention will present the fictional encounter between Condorcet and me in which we debate Condorcet’s essay. The two of us will embark upon our world views of humanism and theism in a dramatic debate, presenting our perspectives and try to get to a resolution
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