1,423 research outputs found

    On the possibility of calibrating urban storm-water drainage models using gauge-based adjusted radar rainfall estimates

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    Traditionally, urban storm water drainage models have been calibrated using only raingauge data, which may result in overly conservative models due to the lack of spatial description of rainfall. With the advent of weather radars, radar rainfall estimates with higher temporal and spatial resolution have become increasingly available and have started to be used operationally for urban storm water model calibration and real time operation. Nonetheless, the insufficient accuracy of radar rainfall estimates has proven problematic and has hindered its widespread practical use. This work explores the possibility of improving the applicability of radar rainfall estimates to the calibration of urban storm-water drainage models by employing gauge-based radar rainfall adjustment techniques. Four different types of rainfall estimates were used as input to the recently verified urban storm water drainage models of the Beddington catchment in South London; these included: raingauge, block-kriged raingauge, radar (UK Met Office Nimrod) and the adjusted (or merged) radar rainfall estimates. The performance of the simulated flow and water depths was assessed using measurements from 78 gauges. Results suggest that a better calibration could be achieved by using the block-kriged raingauge and the adjusted radar estimates as input, as compared to using only radar or raingauge estimates

    Stochastic evaluation of sewer inlet capacity on urban pluvial flooding

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    In this paper we present an innovative methodology to stochastically assess the impact of sewer inlet conditions on urban pluvial flooding. The results showed that sewer inlet capacity can have a large impact on the occurrence of urban pluvial flooding. The methodology is a useful tool for dealing with uncertainties in sewer inlet operational conditions and contribute to comprehensive assessment of urban pluvial risk assessment

    A rapide method for separation of adults in a mixed population of Steinernema carpocapsae (Nematoda : Steinernematidae)

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    La sélection d'un grand nombre de nématodes viables est une condition impérative pour les études sur la physiologie de #Steinernema carpocapsae$. Est décrite ici une méthode rapide et pratique permettant la séparation des mâles et des femelles de ce nématode à partir d'une suspension contenant une population brute. Pour l'utilisation de cette méthode, la densité des mâles et des femelles est déterminée par application de la loi de Stokes modifiée. Les adultes sont séparés dans un gradient discontinu de saccharose s'étageant de 10 et 20%. Quatre-vingt quinze pour cent des mâles et des femelles isolés grâce à cette méthode restent viables. (Résumé d'auteur

    Observations of Reconnection Flows in a Flare on the Solar Disk

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    Magnetic reconnection is a well-accepted part of the theory of solar eruptive events, though the evidence is still circumstantial. Intrinsic to the reconnection picture of a solar eruptive event, particularly in the standard model for two-ribbon flares ("CSHKP" model), are an advective flow of magnetized plasma into the reconnection region, expansion of field above the reconnection region as a flux rope erupts, retraction of heated post-reconnection loops, and downflows of cooling plasma along those loops. We report on a unique set of SDO/AIA imaging and Hinode/EIS spectroscopic observations of the disk flare SOL2016-03-23T03:54 in which all four flows are present simultaneously. This includes spectroscopic evidence for a plasma upflow in association with large-scale expanding closed inflow field. The reconnection inflows are symmetric, and consistent with fast reconnection, and the post-reconnection loops show a clear cooling and deceleration as they retract. Observations of coronal reconnection flows are still rare, and most events are observed at the solar limb, obscured by complex foregrounds, making their relationship to the flare ribbons, cusp field and arcades formed in the lower atmosphere difficult to interpret. The disk location and favorable perspective of this event have removed these ambiguities giving a clear picture of the reconnection dynamics.Comment: 9 pages, 5 figures, and 1 table. Accepted for publication in ApJ

    A Simplified Method to Select Combined Energy Systems

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    The European Union aims to ensure that investment in energy efficiency measures is cost- effective. Thus, the minimum energy performance requirements of buildings must follow the so-called cost-optimal levels. It is known that the impact of a specific measure on the energy performance is affected by others measures when implemented simultaneously, influencing its profitability. For this reason, the profitability of a given package of measures cannot result from the simple sum of potential benefits of each measure. Consequently, to define a cost-optimal solution it is needed to run a great amount of combinations, implying an expensive computational effort. In order to help with the selection of the energy systems, this work proposes a simplified method for selecting heating and domestic hot water systems as a function of the following variables: initial investment, maintenance cost, energy needs and cost, and efficiency of energy systems. The proposed method is user-friendly and can assist various stakeholders: policy makers, energy experts, suppliers of products and services and building owners.Sérgio Tadeu is grateful for the financial support provided by the Fundação de Amparo à Pesquisa do Estado de São Paulo – FAPESP, through grant PIPE - 2016/00880-9 (Brazil). Márcio Gonçalves is grateful for the support by the doctoral FCT grant PD/BD/135194/2017. This work was framed within the project Expert A+ (POCI-01-0246-FEDER-026751) funded by Portugal 2020 through the COMPETE 2020 programme

    Blood lactate, pH, base excess and pCO(2) as prognostic indicators in caesarean-born kids from goats with pregnancy toxaemia

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    Research Areas: Veterinary SciencesArticle in International JournalsABSTRACT - The objective of this study was to identify the prognostic value for survival of blood parameters in the immediate post-caesarean surgery period in kids born from pregnancy toxaemia (PT) goats. This study involved 10 PT goats, in which a caesarean surgery was performed. Twenty-five kids were born after caesarean surgery of which 16 survived. A blood sample was collected from the jugular vein of the 10 goats and from the kids immediately after caesarean surgery (within 15 min). There were differences between the kids that survived and the kids that did not survive concerning the blood levels of pH (7.22 vs 7.00), base excess (- 9 vs - 18 mmol/L), pCO(2) (46 vs 62 mmHg) and L-lactate (5.6 vs 16 mmol/L). Maternal ketoacidosis due to PT has a negative impact on the survival rate of the offspring. This appears to be associated to a metabolic acidosis of the offspring. However, the only blood parameter in which there was a strong association between the maternal and newborn kids was blood urea nitrogen (r = 0.97).Barao & Barao and Faculdade de Medicina Veterinaria -Universidade de Lisboainfo:eu-repo/semantics/publishedVersio

    Quantifying the impact of small scale unmeasured rainfall variability on urban runoff through multifractal downscaling: A case study

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    International audienceThis paper aims at quantifying the uncertainty on urban runoff associated with the unmeasured small scale rainfall variability, i.e. at a resolution finer than 1. km. ×. 1. km. ×. 5. min which is usually available with C-band radar networks. A case study is done on the 900. ha urban catchment of Cranbrook (London). A frontal and a convective rainfall event are analysed. An ensemble prediction approach is implemented, that is to say an ensemble of realistic downscaled rainfall fields is generated with the help of universal multifractals, and the corresponding ensemble of hydrographs is simulated. It appears that the uncertainty on the simulated peak flow is significant, reaching for some conduits 25% and 40% respectively for the frontal and the convective events. The flow corresponding the 90% quantile, the one simulated with radar distributed rainfall, and the spatial resolution are power law related. © 2012 Elsevier B.V

    Enhancement of urban pluvial flood risk management and resilience through collaborative modelling: a UK case study

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    This paper presents the main findings and lessons learned from the development and implementation of a new methodology for collaborative modelling, social learning and social acceptance of flood risk management technologies. The proposed methodology entails three main phases: (1) stakeholder analysis and engagement; (2) improvement of urban pluvial flood modelling and forecasting tools; and (3) development and implementation of web-based tools for collaborative modelling in flood risk management and knowledge sharing. The developed methodology and tools were tested in the Cranbrook catchment (London Borough of Redbridge, UK), an area that has experienced severe pluvial (surface) flooding in the past. The developed methodologies proved to be useful for promoting interaction between stakeholders, developing collaborative modelling and achieving social acceptance of new technologies for flood risk management. Some limitations for stakeholder engagement were identified and are discussed in the present paper
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