16,557 research outputs found

    Runoff on rooted trees

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    We introduce an idealised model for overland flow generated by rain falling on a hill-slope. Our prime motivation is to show how the coalescence of runoff streams promotes the total generation of runoff. We show that, for our model, as the rate of rainfall increases in relation to the soil infiltration rate, there is a distinct phase-change. For low rainfall (the subcritical case) only the bottom of the hill-slope contributes to the total overland runoff, while for high rainfall (the supercritical case) the whole slope contributes and the total runoff increases dramatically. We identify the critical point at which the phase-change occurs, and show how it depends on the degree of coalescence. When there is no stream coalescence the critical point occurs when the rainfall rate equals the average infiltration rate, but when we allow coalescence the critical point occurs when the rainfall rate is less than the average infiltration rate, and increasing the amount of coalescence increases the total expected runoff

    DTI Economics Paper No. 2: A comparative study of the British and Italian Textile and Clothing Industries.

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    Commissioned by: Association of Suppliers to the British Clothing Industry Conference, Hucknell, Nottingham, February 2004 During the 1990s the Italian clothing and textiles industry grew while the British, French and German textile and clothing industries declined by 40%. In 2001 the Italian textiles & clothing sector was three times larger than the British, accounting for 11.7% of Italian manufacturing output but only 3.3% in Britain. In 2000 Italian fabric exports were 15 times that of the UK. The study was conducted in response to a recommendation by the Textiles and Clothing Strategy Group (TCSG), comprising UK industry, trade unions, Higher Education and the DTI. The purpose of the study was to account for these differences, assess relative merits against value for money and identify best practice in the Italian industry. The methodology comprised comparative analysis and case studies of British and Italian textile mills and tailoring manufacturers, based on my initial recommendations. We visited 5 textile mills in Yorkshire and 15 in Italy plus 3 factories in each country. I conducted a detailed comparative technical analysis of the construction of suit jackets against 13 devised criteria, a number of interviews,compared technologies, equipment and manufacturing methods across all factories, against 8 criteria, drawing on my specialist knowledge and experience as a menswear clothing technologist. The technical reports I compiled formed a section of the final report. Findings were presented to the Clothing Strategy Group and published by the DTI as their Economic Paper No 2 . I made further presentations to industry and academic groups including ASBCI, FCDE, The Textile Society, Savile Row Tailors Association, and LSE. Other outcomes were a publication in the Journal of the Textile Society Text, an article in Selvedge magazine and contributions to the Encyclopaedia of Clothing by Thomson Gale. As a result of this research further consultancy projects have been conducted with the Industry Forum and ASBCI

    Short Sale Constraints and Stock Returns

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    Stocks can be overpriced when short sale constraints bind. We study the costs of short selling equities, 1926-1933, using the publicly observable market for borrowing stock. Some stocks are sometimes expensive to short, and it appears that stocks enter the borrowing market when shorting demand is high. We find that stocks that are expensive to short or which enter the borrowing market have high valuations and low subsequent returns, consistent with the overpricing hypothesis. Size-adjusted returns are one to two percent lower per month for new entrants, and despite high costs it is profitable to short them.

    A qualitative evaluation of home based contraceptive and sexual health care for teenage mothers

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    This paper reports on the findings from a qualitative study exploring the experiences of teenage mothers using a nurse-led, home-based contraceptive service designed to prevent repeat unplanned pregnancies. The aim was to understand if, and how the service was effective in equipping teenage mothers to make informed choices about contraception, thus preventing a second pregnancy. Unplanned teenage pregnancy remains a significant focus of health and social policy in the United Kingdom (UK). Despite the long-term pattern of declining conception rates, the UK continues to report higher rates than comparable countries elsewhere in Europe. Current estimates suggest that approximately one fifth of births amongst under 18’s are repeat pregnancies (Teenage Pregnancy Independent Advisory Group, 2009). Services that are designed to reduce second unplanned pregnancies are an important element in promoting teenage sexual health. However, there has been no UK research that explores this kind of service and the experiences of service users. We conducted a qualitative interview study. From 2013–2014 we interviewed 40 teenage mothers who had engaged with the nurse-led, home-based contraceptive service. The data demonstrates that the service was effective in preventing repeat pregnancies in a number of cases. Among the aspects of the service which were found to contribute to its effectiveness were privacy, convenience, flexibility, appropriately timed access, the non-judgemental attitude of staff and ongoing support

    Growth and Regional Inequality in China During the Reform Era

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    Chinese city-level data indicate that differences in growth rates are far more severe than indicated in previous studies which typically use data at higher levels of aggregation. We estimate growth equations using city-level data and find that the policy of awarding a special economic zone status enhances growth substantially, increasing annual growth rates by 5.5 percentage points. Annual growth rates of open coastal cities are, on average, 3 percentage points higher. Our qualitative results on the role of policy and the effects of FDI are similar to those of earlier studies that have employed provincial-level data; but, quantitatively, our results are substantially different. We also provide evidence of an indirect role of policy in the growth process through its ability to attract growth-enhancing foreign direct investment.http://deepblue.lib.umich.edu/bitstream/2027.42/39946/2/wp561.pd

    The use of ERTS/LANDSAT imagery in relation to airborne remote sensing for terrain analysis in Western Queensland, Australia

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    The author has identified the following significant results. LANDSAT 1 and 2 imagery contrast the geology of the Cloncurry-Dobbyn and the Gregory River-Mt. Isa areas very clearly. Known major structural features and lithological units are clearly displayed while, hitherto unknown lineaments were revealed. Throughout this area, similar rock types produce similar spectral signatures, e.g. quartzites produce light signatures, iron rich rocks produce dark signatures. More geological data are discernible at the 1:50,000 scale than on the 1:250,000 scale. Ore horizons may be identified at the 1:50,000 scale, particularly where they are associated with iron rich rocks. On the level plains north of Cloncurry, distinctive spectral signatures produced by the combined reflectances of plant cover, soils, and geology, distinguish different types of superficial deposits. Existing and former channels of the Cloncurry and Williams Rivers are distinguished at the 1:50,000 scale on both the LANDSAT 1 and 2 imagery. On the Cloncurry Plains, fence lines are discernible on the 1:50,000 LANDSAT 2 imagery
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