6,459 research outputs found

    Kosovo after the ICJ opinion

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    Modulated spin and charge densities in cuprate superconductors

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    Neutron scattering experiments have played a crucial role in characterizing the spin and charge correlations in copper-oxide superconductors. While the data are often interpreted with respect to specific theories of the cuprates, an attempt is made here to distinguish those facts that can be extracted empirically, and the connections that can be made with minimal assumptions.Comment: 6 pp., LaTeX, 2 col., uses espcrc2.sty + psfig.sty, 2 eps figures; Proc. of the International Conf. on Neutron Scattering, Toronto, Aug. 1997, to be published in Physica

    Cell Model of In-cloud Scavenging of Highly Soluble Gases

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    We investigate mass transfer during absorption of highly soluble gases such as HNO_{3}, H_{2}O_{2} by stagnant cloud droplets in the presence of inert admixtures. Thermophysical properties of the gases and liquids are assumed to be constant. Diffusion interactions between droplets, caused by the overlap of depleted of soluble gas regions around the neighboring droplets, are taken into account in the approximation of a cellular model of a gas-droplet suspension whereby a suspension is viewed as a periodic structure consisting of the identical spherical cells with periodic boundary conditions at the cell boundary. Using this model we determined temporal and spatial dependencies of the concentration of the soluble trace gas in a gaseous phase and in a droplet and calculated the dependence of the scavenging coefficient on time. It is shown that scavenging of highly soluble gases by cloud droplets leads to essential decrease of soluble trace gas concentration in the interstitial air. We found that scavenging coefficient for gas absorption by cloud droplets remains constant and sharply decreases only at the final stage of absorption. In the calculations we employed gamma size distribution of cloud droplets. It was shown that despite of the comparable values of Henry's law constants for the hydrogen peroxide (H2O2) and the nitric acid (HNO3), the nitric acid is scavenged more effectively by cloud than the hydrogen peroxide due to a major affect of the dissociation reaction on HNO3 scavenging.Comment: 28 pages, including 11 Figures, 1 Tabl

    A Two-level Prediction Model for Deep Reactive Ion Etch (DRIE)

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    We contribute a quantitative and systematic model to capture etch non-uniformity in deep reactive ion etch of microelectromechanical systems (MEMS) devices. Deep reactive ion etch is commonly used in MEMS fabrication where high-aspect ratio features are to be produced in silicon. It is typical for many supposedly identical devices, perhaps of diameter 10 mm, to be etched simultaneously into one silicon wafer of diameter 150 mm. Etch non-uniformity depends on uneven distributions of ion and neutral species at the wafer level, and on local consumption of those species at the device, or die, level. An ion–neutral synergism model is constructed from data obtained from etching several layouts of differing pattern opening densities. Such a model is used to predict wafer-level variation with an r.m.s. error below 3%. This model is combined with a die-level model, which we have reported previously, on a MEMS layout. The two-level model is shown to enable prediction of both within-die and wafer-scale etch rate variation for arbitrary wafer loadings.Singapore-MIT Alliance (SMA

    Human security and the rise of the social

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    As the concept of human security has become part of the mainstream discourse of international politics it should be no surprise that both realist and critical approaches to international theory have found the agenda wanting. This article seeks to go beyond both the realist and biopolitical critiques by situating all three – political realism, biopolitics and human security – within the history and theory of the modern rise of the social realm from late eighteenth and nineteenth century Europe. Human security is the further expansion of social forms of governance under capitalism, more specifically a form of socialpolitik than realpolitik or biopolitics. Drawing on the work of historical sociologist Robert Castel and political theorist Hannah Arendt, the article develops an alternative framework with which to question the extent to which ‘life’ has become the subject of global intervention through the human security agenda
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