2,745 research outputs found

    Do Aid Agencies Have an Ethical Duty to Comply with Researchers? A Response to Rennie.

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    Medical AID organisations such as Médecins Sans Frontières receive several requests from individuals and international academic institutions to conduct research at their implementation sites in Africa. Do AID agencies have an ethical duty to comply with research requests? In this paper we respond to the views and constructed theories (albeit unfounded) of one such researcher, whose request to conduct research at one of our sites in the Democratic Republic of Congo was turned down

    Multilingual higher education in European regions

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    Although English is often conceived as the dominant language of international and transnational communication in higher education, it is not the only medium of communication in the academic community. National, regional and local languages remain important, in some European countries more than in others. In Janssens, Mamadouh and Marácz (2011) we have argued that too little attention is paid to languages in the realm between the local and the global domain: what we called languages of regional communication, that can be used in multilingual and in border regions. Here we focus on multilingualism in higher education in regions where global and regional languages are in contact or compete with each other for hegemony. Will the languages - in the 20th century quite often national languages - of higher education be replaced by English or will there be developing a more balanced situation where next to English also national, regional and local languages play a role in higher education. We will conclude in this paper that the rise of English in the higher education in the context of national, regional and local languages is impressive but that the non-global languages have a robust position in higher education that is rooted in history and connected to the identity of its speakers. The case studies presents evidence from regions where multilingualism does not necessary mean Englishization. Flanders with the role of French, Dutch and English, Hungary and the Carpathian Basin with Hungarian as a national and minority language, and universities on the border between Romance and Germanic languages

    Systematics of heavy-ion fusion hindrance at extreme sub-barrier energies

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    The recent discovery of hindrance in heavy-ion induced fusion reactions at extreme sub-barrier energies represents a challenge for theoretical models. Previously, it has been shown that in medium-heavy systems, the onset of fusion hindrance depends strongly on the "stiffness" of the nuclei in the entrance channel. In this work, we explore its dependence on the total mass and the QQ-value of the fusing systems and find that the fusion hindrance depends in a systematic way on the entrance channel properties over a wide range of systems.Comment: Submitted to Phys. Rev. Lett., 5 pages, 3 figure

    Octupole Effects at Super and Normal Deformation

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    This presentation deals with recent results on the onset of octupole collectivity in superdeformed nuclei of the A {approx} 190 and A {approx} 150 regions as well as in actinide nuclei at normal deformation. It is shown that most of the properties of these negative parity sequences can be understood in terms of Random Phase Approximation (RPA) calculations, although the observations in some Pu isotopes continue to be a challenge to interpret

    Lifetime measurements of Triaxial Strongly Deformed bands in 163^{163}Tm

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    With the Doppler Shift Attenuation Method, quadrupole transition moments, QtQ_t, were determined for the two recently proposed Triaxial Strongly Deformed (TSD) bands in 163^{163}Tm. The measured QtQ_t moments indicate that the deformation of these bands is larger than that of the yrast, signature partners. However, the measured values are smaller than those predicted by theory. This observation appears to be valid for TSD bands in several nuclei of the regionComment: 8 pages, 5 figures. Submitted to Physical Review

    Enhanced transmission versus localization of a light pulse by a subwavelength metal slit: Can the pulse have both characteristics?

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    The existence of resonant enhanced transmission and collimation of light waves by subwavelength slits in metal films [for example, see T.W. Ebbesen et al., Nature (London) 391, 667 (1998) and H.J. Lezec et al., Science, 297, 820 (2002)] leads to the basic question: Can a light be enhanced and simultaneously localized in space and time by a subwavelength slit? To address this question, the spatial distribution of the energy flux of an ultrashort (femtosecond) wave-packet diffracted by a subwavelength (nanometer-size) slit was analyzed by using the conventional approach based on the Neerhoff and Mur solution of Maxwell's equations. The results show that a light can be enhanced by orders of magnitude and simultaneously localized in the near-field diffraction zone at the nm- and fs-scales. Possible applications in nanophotonics are discussed.Comment: 5 figure

    Kaehler Manifolds of Quasi-Constant Holomorphic Sectional Curvatures

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    The Kaehler manifolds of quasi-constant holomorphic sectional curvatures are introduced as Kaehler manifolds with complex distribution of codimension two, whose holomorphic sectional curvature only depends on the corresponding point and the geometric angle, associated with the section. A curvature identity characterizing such manifolds is found. The biconformal group of transformations whose elements transform Kaehler metrics into Kaehler ones is introduced and biconformal tensor invariants are obtained. This makes it possible to classify the manifolds under consideration locally. The class of locally biconformal flat Kaehler metrics is shown to be exactly the class of Kaehler metrics whose potential function is only a function of the distance from the origin in complex Euclidean space. Finally we show that any rotational even dimensional hypersurface carries locally a natural Kaehler structure, which is of quasi-constant holomorphic sectional curvatures.Comment: 36 page

    Fusion-Fission of 16O+197Au at Sub-Barrier Energies

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    The recent discovery of heavy-ion fusion hindrance at far sub-barrier energies has focused much attention on both experimental and theoretical studies of this phenomenon. Most of the experimental evidence comes from medium-heavy systems such as Ni+Ni to Zr+Zr, for which the compound system decays primarily by charged-particle evaporation. In order to study heavier systems, it is, however, necessary to measure also the fraction of the decay that goes into fission fragments. In the present work we have, therefore, measured the fission cross section of 16O+197Au down to unprecedented far sub-barrier energies using a large position sensitive PPAC placed at backward angles. The preliminary cross sections will be discussed and compared to earlier studies at near-barrier energies. No conclusive evidence for sub-barrier hindrance was found, probably because the measurements were not extended to sufficiently low energies.Comment: Fusion06 - Intl. Conf. on Reaction Mechanisms and Nuclear Structure at the Coulomb Barrier, San Servolo, Venezia, Italy, March 19-223, 2006 5 pages, 4 figure
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