10,081 research outputs found

    The separation test in vacuum of the Ariane 4 payload fairing

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    The separation tests performed during the qualification test program of the Ariane 4 Payload Fairing are described. This is the first fairing structure to be developed using carbon fiber technology. Two separation tests were performed under vacuum conditions. The primary objectives of these tests were to verify compliance with the vehicle imposed requirements and to establish the behavioral characteristics of the fairing structure itself

    Rearing of \u3ci\u3eScolytus Multistraiatus\u3c/i\u3e (Marsham) (Scolytidae: Coleoptera) for Toxicological Experiments

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    (excerpt) In a study of the oral and contact toxicity of methoxychlor residues to the smaller European elm bark beetle, S, multistriatus, it is essential to have beetle material available which is of uniform physiological condition and age (Riedl, 197 3). Several rearing containers for bark beetles have been described in the literature (Clark and Osgood, 1964; Fox, 1958; Germain and Wygant, 1967; Schmitz, 1972). A common problem in such containers appears to be fungus growth on the logs due to insufficient ventilation and high humidity. Although these environmental conditions might not cause high mortality, they can render emerging beetles unsuitable for bioassays. In order to guarantee fresh beetle material of uniform age newly emerged beetles must be extracted immediately. This paper describes emergence drums with a ventilation system that prevents fungus growth. Also described is an efficient extraction device which prevented the insect from moving back into the rearing container once it reached the collecting apparatus

    Aspects of the Feeding Behavior of \u3ci\u3eScolytus Multistriatus\u3c/i\u3e (Marsham) (Scoltytidae: Coleoptera) and Implications for Control

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    (excerpt) Successful protection of elm trees can only be accomplished by means of thorough understanding of the feeding behavior of the smaller European elm bark beetle, Scolytus multistriatus (Marsham). Wolfenbarger and Buchanan (1939) and Whitten (1958) noted that most feeding occurred in the outer portion of the upper crown region, but offered no quantitative data. Therefore, this study was initiated to investigate the regional distribution of feeding injuries along a vertical and horizontal gradient in native American elm, Ulmus americana L

    Whither national citizenship?

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    Constructing mass tourism

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    The term ‘mass tourism’ can simply be an empirical description of tourism enjoyed by many in modern, industrial societies. However, in context, it often refers to more than this. The ‘mass’ involves an aggregation of individuals, and involves assumptions and inferences about those individuals and the society in which they live. Hence mass tourism is, in an important sense, a social construct. It is therefore surprising that there is little consideration of this aspect of ‘mass tourism’ and its corollary, the ‘mass tourist’ in relevant literature. The article develops a provisional periodisation of mass tourism in social thought, linking constructions of the mass to the politics of the day. It has an exploratory character, suggesting themes for contestation and / or further research. It indicates changes in the view of mass tourism, but also important continuities relating to an assumption of a lack of agency on the part of mass tourists

    Citizenship, global citizenship and volunteer tourism: a critical analysis

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    This paper reflects on the association of volunteer tourism with global citizenship and argues that it involves outsourcing citizenship to ‘the globe’ in a manner unlikely to benefit global understanding or development politics. Volunteer tourism is strongly associated with global citizenship. Global citizenship, in turn, is associated with a better world. A key claim made about global citizenship is that it enables people to discharge their responsibilities to others in distant lands in an ethical way, less constrained by national interests. Yet global citizenship involves a reworking of the concept of citizenship not only spatially from nation to globe, but also politically from nation state and polity to non-governmental organisations and consumption (in this case, of tourism). The paper argues that in a number of ways the association of volunteer tourism with this geographically expanded but politically constricted notion of citizenship both reinforces a limited politics, and also limits the capacity of voluntourism to enlighten. By contrast, it is argued that a consideration of republican citizenship both clarifies these limits and suggests a more progressive rationale for volunteer travel

    Simple Phase Bias for Superconducting Circuits

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    A phase-bias tool, based on a trapped fluxoid in a ring, is proposed and demonstrated. It can provide arbitrary phase values and is simple to fabricate. The phase bias has been realized in two superconducting quantum interference devices, where the critical current versus magnetic flux is shown to be shifted by a \pi/2 and \pi.Comment: 5 pages, including 4 figures. Submitted to AP
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