44 research outputs found

    A plausible method for fatigue life prediction of boats in a data scarce environment

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    Within the marine world many boats are constructed from composite materials, that useclassification society rules to predict their strength. As these vessels age, fatigue and remaining lifetime are of considerable interest to owners and operators. This paper seeks to identify an appropriate S-N curve and produce an example lifetime calculation

    Norms, Networks, Power, and Control: Understanding Informal Payments and Brokerage in Cross-Border Trade in Sierra Leone

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    Recent research has cast light on the variety of informal payments and practices that govern the day-to-day interactions between traders and customs agents at border posts in low-income countries. Building on this literature, this paper draws on survey and qualitative evidence in an effort to explore which groups are most advantaged and disadvantaged by the largely informal processes and norms governing cross-border trade. We find that understanding variation in strategies and outcomes across traders can only be effectively understood with reference to the importance of norms, networks, power, and the logic of control.Department for International DevelopmentBill and Melinda Gates Foundatio

    An accurate nucleon-nucleon potential with charge-independence breaking

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    We present a new high-quality nucleon-nucleon potential with explicit charge dependence and charge asymmetry, which we designate Argonne v18v_{18}. The model has a charge-independent part with fourteen operator components that is an updated version of the Argonne v14v_{14} potential. Three additional charge-dependent and one charge-asymmetric operators are added, along with a complete electromagnetic interaction. The potential has been fit directly to the Nijmegen pppp and npnp scattering data base, low-energy nnnn scattering parameters, and deuteron binding energy. With 40 adjustable parameters it gives a χ2\chi^{2} per datum of 1.09 for 4301 pppp and npnp data in the range 0--350 MeV.Comment: 36 pages, PHY-7742-TH-9

    The origins and development of Zuwīla, Libyan Sahara: an archaeological and historical overview of an ancient oasis town and caravan centre

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    ZuwÄ«la in southwestern Libya (Fazzān) was one of the most important early Islamic centres in the Central Sahara, but the archaeological correlates of the written sources for it have been little explored. This paper brings together for the first time a detailed consideration of the relevant historical and archaeological data, together with new AMS radiocarbon dates from several key monuments. The origins of the settlement at ZuwÄ«la were pre-Islamic, but the town gained greater prominence in the early centuries of Arab rule of the Maghrib, culminating with the establishment of an Ibāឍī state ruled by the dynasty of the BanĆ« Khaáč­áč­Äb, with ZuwÄ«la its capital. The historical sources and the accounts of early European travellers are discussed and archaeological work at ZuwÄ«la is described (including the new radiocarbon dates). A short gazetteer of archaeological monuments is provided as an appendix. Comparisons and contrasts are also drawn between ZuwÄ«la and other oases of the ash-Sharqiyāt region of Fazzān. The final section of the paper presents a series of models based on the available evidence, tracing the evolution and decline of this remarkable site

    Forest exploitation in Cameroon (1884-1994): An oxymoron of top-down and bottom-up forest management policy approaches.

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    Forest exploitation in Cameroon goes back to the pre‐colonial period when early ethnic settlers used the ‘law of status’ system to manage land and forests in the territory. With the arrival of colonial powers, beginning with the Germans in 1884, the law of status system was replaced by top‐down state‐centred management system. This top‐down management system was inherited by post‐colonial authorities and enforced until 1994 when a new forestry law was launched, based on bottom‐up management system. This paper reviews all these three systems. Communities are not benefiting from an actual bottom‐up management system. The author argues that the forests sector in Cameroon needs a new management paradigm
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