3,453 research outputs found

    A cost comparison of traditional drainage and SUDS in Scotland

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    The Dunfermline Eastern Expansion (DEX) is a 350 ha mixed development which commenced in 1996. Downstream water quality and flooding issues necessitated a holistic approach to drainage planning and the site has become a European showcase for the application of Sustainable Urban Drainage Systems (SUDS). However, there is minimal data available regarding the real costs of operating and maintaining SUDS to ensure they continue to perform as per their design function. This remains one of the primary barriers to the uptake and adoption of SUDS. This paper reports on what is understood to be the only study in the UK where actual costs of constructing and maintaining SUDS have been compared to an equivalent traditional drainage solution. To compare SUDS costs with traditional drainage, capital and maintenance costs of underground storage chambers of analogous storage volumes were estimated. A whole life costing methodology was then applied to data gathered. The main objective was to produce a reliable and robust cost comparison between SUDS and traditional drainage. The cost analysis is supportive of SUDS and indicates that well designed and maintained SUDS are more cost effective to construct, and cost less to maintain than traditional drainage solutions which are unable to meet the environmental requirements of current legislation

    Early Miocene quantitative calcareous nannofossil biostratigraphy from the tropical Atlantic

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    A quantitative analysis of calcareous nannofossils was conducted on lower Miocene sediments from Ocean Drilling Program Hole 959A on the West African margin. Combined with data from previous investigations of the lower Miocene from the tropical Atlantic, this research identifies and tests the viability of markers used in current zonation schemes, identifies alternative markers for age boundaries, and examines statistically the most probable order of events in the lower Miocene with the use of the ranking and scaling method (RASC)

    High-Resolution Calcareous Nannofossil Biostratigraphy for the Coniacian/Santonian Stage Boundary, Western Interior Basin

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    The Ten Mile Creek area (Dallas, Texas) is a proposed Global Stratotype Section and Point (GSSP) candidate for the Coniacian/Santonian Stage boundary. The Santonian Working Group has designated the first appearance of Inoc¬eramus (Cladoceramus) undulatoplicatus as the diagnostic macrofossil bioevent for the base of the Santonian Stage. Cal¬careous nannofossils were examined from sediments of the Bruceville Marl at the proposed GSSP site and from well-preserved sediments of the coeval Smoky Hill Member-type area (northwestern Kansas) of the Niobrara Formation. Nannofossil bioevents were correlated with the lowest stratigraphic occurrence of I. undulatoplicatus to create a high resolution biostratigraphic framework and stratigraphic proxy for the Coniacian/Santonian Stage transition. Six bioevents are useful for recognition of the Coniacian/Santonian transition within the Bruceville Marl and Smoky Hill Member. The first appearance datums (FADs) of Prediscosphaera desiderograndis, n. sp. and Amphizygus megalops, n. sp. as well as the FADs of two rare taxa, Orastrum campanensis and Tortolithus dodekachelyon, n. sp., are in close stratigraphic proximity to the lowest occurrence of I. undulatoplicatus. In addition, two nannofloral acmes occur near the boundary: Watznaueria quadriradiata and Zeugrhabdotus scutula. This study describes eight new species from the Smoky Hill Chalk type area; Amphizygus megalops, Bifidalithus phenax, Pharus evanescens, Gartnerago margaritatus, Helicolithus tectufissus, Tortolithus dodekachelyon, Prediscosphaera de¬siderograndis and Helicolithus varolii. Light microscope images are provided for rare and well-preserved specimens of Reinhardtites clavicaviformis Varol, 1991, Orastrum campanensis (Cepek) Wind & Wise, 1977, Rhombolithus rhombicum (Bukry) Black, 1973, and Gartnerago clarusora Varol, 1991. This study extends the ranges of several species from those documented in previous literature. Western Interior Basin Late Cretaceous Calcareous Nannofossil Data Set is attached below as a Related file

    Late Albian adaptive radiation in the calcareous nannofossil genus Eiffellithus

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    Enhancing space transportation: The NASA program to develop electric propulsion

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    The NASA Office of Aeronautics, Exploration, and Technology (OAET) supports a research and technology (R and T) program in electric propulsion to provide the basis for increased performance and life of electric thruster systems which can have a major impact on space system performance, including orbital transfer, stationkeeping, and planetary exploration. The program is oriented toward providing high-performance options that will be applicable to a broad range of near-term and far-term missions and vehicles. The program, which is being conducted through the Jet Propulsion Laboratory (JPL) and Lewis Research Center (LeRC) includes research on resistojet, arcjets, ion engines, magnetoplasmadynamic (MPD) thrusters, and electrodeless thrusters. Planning is also under way for nuclear electric propulsion (NEP) as part of the Space Exploration Initiative (SEI)

    Experimental Investigation of the NASA Common Research Model with a Natural Laminar Flow Wing in the NASA Langley National Transonic Facility

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    A test of the new NASA Common Research Model with a Natural Laminar Flow (CRMNLF) semispan wing in the NASA Langley National Transonic Facility (NTF) was completed in October 2018. The main focus of this test was the evaluation of the extent of laminar flow on the CRM-NLF wing at various Reynolds numbers and test conditions. During this test, data were acquired at chord Reynolds numbers from 10 to 30 million and at Mach numbers ranging from 0.84 to 0.86. This investigation provided valuable insight into the necessary procedures for laminar flow testing in the NTF. It also significantly advanced the new carbonbased heating layer technique to improve the quality of transition visualization data from temperature sensitive paint (TSP) in a cryogenic wind tunnel

    The role of ECL2 in CGRP receptor activation: a combined modelling and experimental approach

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    The calcitonin gene-related peptide (CGRP) receptor is a complex of a calcitonin receptor-like receptor (CLR), which is a family B G-protein-coupled receptor (GPCR) and receptor activity modifying protein 1. The role of the second extracellular loop (ECL2) of CLR in binding CGRP and coupling to Gs was investigated using a combination of mutagenesis and modelling. An alanine scan of residues 271–294 of CLR showed that the ability of CGRP to produce cAMP was impaired by point mutations at 13 residues; most of these also impaired the response to adrenomedullin (AM). These data were used to select probable ECL2-modelled conformations that are involved in agonist binding, allowing the identification of the likely contacts between the peptide and receptor. The implications of the most likely structures for receptor activation are discussed.</jats:p

    Calcareous nannofossil assemblage changes across the Paleocene–Eocene Thermal Maximum: Evidence from a shelf setting

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    Biotic response of calcareous nannoplankton to abrupt warming across the Paleocene/Eocene boundary reflects a primary response to climatically induced parameters including increased continental runoff of freshwater, global acidification of seawater, high sedimentation rates, and calcareous nannoplankton assemblage turnover. We identify ecophenotypic nannofossil species adapted to low pH conditions (Discoaster anartios, D. araneus, Rhomboaster spp.), excursion taxa adapted to the extremely warm climatic conditions (Bomolithus supremus and Coccolithus bownii), three species of the genus Toweius (T. serotinus, T. callosus, T. occultatus) adapted to warm, rather than cool, water conditions, opportunists adapted to high productivity conditions (Coronocyclus bramlettei, Neochiastozygus junctus), and species adapted to oligotropic and/or cool‐water conditions that went into refugium during the PETM (Zygrablithus bijugatus, Calcidiscus? parvicrucis and Chiasmolithus bidens). Discoaster anartios was adapted to meso- to eutrophic, rather than oligotrophic, conditions. Comparison of these data to previous work on sediments deposited on shelf settings suggests that local conditions such as high precipitation rates and possible increase in major storms such as hurricanes resulted in increased continental runoff and high sedimentation rates that affected assemblage response to the PETM

    Preliminary Results from an Experimental Assessment of a Natural Laminar Flow Design Method

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    A 5.2% scale semispan model of the new Common Research Model with Natural Laminar Flow (CRM-NLF) was tested in the National Transonic Facility (NTF) at the NASA Langley Research Center. The model was tested at transonic cruise flight conditions with Reynolds numbers based on mean aerodynamic chord ranging from 10 to 30 million. The goal of the test was to experimentally validate a new design method, referred to as Crossflow Attenuated NLF (CATNLF), which shapes airfoils to have pressure distributions that delay transition on wings with high sweep and Reynolds numbers. Additionally, the test aimed to characterize the NTF laminar flow testing capabilities, as well as establish best practices for laminar flow wind tunnel testing. Preliminary results regarding the first goal of validating the new design method are presented in this paper. Experimental data analyzed in this assessment include surface pressure data and transition images. The surface pressure data acquired during the test agree well with computational fluid dynamics (CFD) results. Transition images at a variety of Reynolds numbers and angles of attack are presented and compared to computational transition predictions. The experimental data are used to assess transition due to a turbulent attachment line, as well as crossflow and Tollmien-Schlichting modal instabilities. Preliminary results suggest the CATNLF design method is successful at delaying transition on wings with high sweep. Initial analysis of the transition front images showed transition Reynolds numbers that exceed historic experimental values at similar sweep angles. , section lif

    Cytochrome P450 3A4 and P‐glycoprotein mediate the interaction between an oral erythromycin breath test and rifampin

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109878/1/cptclpt2002114.pd
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