5 research outputs found

    Grouting in Soils Vol. 2: Design and Operations Manual

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    This manual provides guidelines for the design and conduct of soil grouting operations, from the selection of the grout and the design of the injection pattern to construction control methods and evaluation of the completed treatment. This report emphasizes grouting applications associated with excavation and tunneling in an urban environment. It describes the three general grouting techniques - permeation, void filling, and compaction - and covers in detail, six applications: (1) groundwater control, (2) sand stabilization, (3) soil strengthening, (4) backpacking tunnel liners, (5) leak repairs, and (6) tieback anchorages. A companion report, Volume 1 (FHWA-RD-76-26) is entitled "A State-of-the-Art Report.

    Intraspecific Variation in Podestemum Ceratophyllum (Postostemacea): Evidence of Refugia and Colonization Since the Last Glacial Maximum

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    Premise of the Study: Intraspecifi c variation among 20 populations of Podostemum ceratophyllum Michx. was investigated to test the hypothesis of range expansion from southern refugia since the last glacial maximum. Methods: Six noncoding regions of chloroplast DNA were sequenced in 60 individuals. Populations were divided into two groups, north and south of the glacial boundary, in addition to isolated populations in Arkansas and Honduras. Variation in populations north of the boundary was compared with variation in populations to the south and in the isolated populations. Key Results: Nucleotide diversity was an order of magnitude lower in populations north of the glacial boundary than in those to the south. The Arkansas and Honduras populations showed no variation. The predominant haplotype in northern populations was also found in a Virginia population. Conclusions: Reduced variation north of the glacial boundary suggests a founder event associated with range expansion since the last glacial maximum. Colonization probably occurred from populations in refugia located several hundred kilometers south of the glacial boundary. The results provide insight into the effects of past and current climate change on patterns of geographic distribution and genetic variation in aquatic plants

    An Analysis of the Effect of Renewable Energy Targets in the Electricity Sector on the New Zealand Gas Industry

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    Prepared for: Petroleum Exploration and Production Association of New Zealan

    The Health Impacts of Ethanol Blend Petrol

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    A measurement program designed to evaluate health impacts or benefits of using ethanol blend petrol examined exhaust and evaporative emissions from 21 vehicles representative of the current Australian light duty petrol (gasoline) vehicle fleet using a composite urban emissions drive cycle. The fuels used were unleaded petrol (ULP), ULP blended with either 5% ethanol (E5) or 10% ethanol (E10). The resulting data were combined with inventory data for Sydney to determine the expected fleet emissions for different uptakes of ethanol blended fuel. Fleet ethanol compatibility was estimated to be 60% for 2006, and for the air quality modelling it was assumed that in 2011 over 95% of the fleet would be ethanol compatible. Secondary organic aerosol (SOA) formation from ULP, E5 and E10 emissions was studied under controlled conditions by the use of a smog chamber. This was combined with meteorological data from Sydney for February 2004 and the emission data (both measured and inventory data) to model pollutant concentrations in Sydney’s airshed for 2006 and 2011. These concentrations were combined with the population distribution to evaluate population exposure to the pollutant. There is a health benefit to the Sydney population arising from a move from ULP to ethanol blends in spark-ignition vehicles. Potential health cost savings for Urban Australia (Sydney, Melbourne, Brisbane and Perth) are estimated to be A39million(in2007dollars)fora5039 million (in 2007 dollars) for a 50% uptake (by ethanol compatible vehicles) of E10 in 2006 and 42 million per annum for a 100% take up of E10 in 2011. Over 97% of the estimated health savings are due to reduced emissions of PM2.5 and consequent reduced impacts on mortality and morbidity (e.g., asthma, cardiovascular disease). Despite more petrol-driven vehicles predicted for 2011, the quantified health impact differential between ULP and ethanol fuelled vehicles drops from 2006 to 2011. This is because modern petrol vehicles, with lower emissions than their older counterparts, will make up a higher proportion of the fleet in the future. Hence the beneficial effects of reductions in particulate matter become less significant as the fleet as a whole produces lower emissions

    Suicide in Nepal: Qualitative Findings from a Modified Case-Series Psychological Autopsy Investigation of Suicide Deaths

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