634 research outputs found

    Solar and geothermal energy for low-carbon space heating and energy independence.

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    In developed countries, space heating is highly dependent on fossil fuels consumption. Also, the non-renewable fuels combustion emits CO2 which is claimed to impact the most on greenhouse effect. The utilization of Renewable Energy Sources (RES) for space heating, instead of fossil fuels, has been found to be feasible for systems’ greater energy independence and reduction in CO2 emissions. Solar Assisted Ground Source Heat Pump (SAGSHP) systems are a promising technology which can be used to accomplish the above framed target. A mathematic model of a SAGSHP system was built and a parametric analysis for Birmingham which is a city located in the UK’s West Midlands was conducted. Two scenarios based on two different dwellings were investigated, the one was a house recently erected and the other was a refurbished house. As regards the new house, simulation results showed that the utilized energy for space heating and Domestic Hot Water (DHW) can vary from 33% up to 73% RES dependent and, at the same time, electricity generation can be 2.21 times higher than the system’s demand. As regards the energy renovated dwelling, the RES contribution to the delivered heat was found to be between the 33% and 63%, while the electricity generation did not result in any surplus energy from the consumed. Finally, by making use of SAGSHP system instead of a natural Gas boiler, the reduction of CO2 emissions was found to be between 300kg/year and 2,170kg/year for the new building and from 245kg/year up to 3,221kg/year for the refurbished house, respectively. In both cases, SAGSHP systems proved to be a feasible practice for greater energy independence from non-renewable energy sources with substantial positive impact on the greenhouse gasses emissions

    Investigating the Geometrical Structure of Disordered Sphere Packings

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    Bead packs of up to 150,000 mono-sized spheres with packing densities ranging from 0.58 to 0.64 have been studied by means of X-ray Computed Tomography. These studies represent the largest and the most accurate description of the structure of disordered packings at the grain-scale ever attempted. We investigate the geometrical structure of such packings looking for signatures of disorder. We discuss ways to characterize and classify these systems and the implications that local geometry can have on densification dynamics.Comment: 3 figures, 9 page

    comparison of severity of sepsis, delay of anti-infective therapy and ESBL genotype

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    Infektionen mit extended-spectrum Betalaktamase-produzierenden Enterobacteriaceae (ESBL-E) sind assoziiert mit einer erhöhten Mortalität. Die Unterschiede im klinischen Bild, die den verschiedenen Spezies der ESBL-E oder ESBL-Genotypen geschuldet sind, wurden noch nicht ausreichend untersucht. Wir führten eine Kohortenstudie zur Bewertung der Risikofaktoren für Sterblichkeit in Fällen mit einer ESBL-E-Bakteriämie (K. pneumoniae oder E. coli) und zur Bewertung der Risikofaktoren für Sepsis mit Organversagen durch. Eingeschlossen wurden alle Patienten unserer Institution mit einer ESBL-E-Bakteriämie in der Zeit von 2008 bis 2011. Epidemiologische Basisdaten, zugrundeliegende Komorbiditäten, Ursprung der Bakteriämie, Schweregrad der Sepsis und Daten zur zeitlichen Verzögerung bis zu Beginn der adäquaten antibiotischen Therapie wurden gesammelt. Die Isolate wurden mittels PCR auf das Vorhandensein von ESBL-Genen und plasmidvermittelten AmpC β-Laktamasen untersucht. Wir führten eine Cox Regressionsanalyse zur Mortalität und eine multivariable logische Regression zu den Risikofaktoren für eine Sepsis mit Organversagen durch. Insgesamt wurden 219 Fälle in die Analyse eingeschlossen: 71,3% mit E. coli, 26,9% mit K. pneumoniae. Wir fanden keine signifikanten Unterschiede bei der Krankenhaussterblichkeit (ESBL-E. coli 23.8% vs. ESBL-K. pneumoniae 27.1%, p=0.724). Bakteriämien mit K. pneumoniae (OR 4.5, p<0.001), Lebererkrankungen (OR 3.4, p=0.004) oder Nierenerkrankungen (OR 6.8, p<0.001) waren mit einem erhöhten Risiko einer Sepsis mit Organversagen vergesellschaftet. Wir fanden signifikante Unterschiede im klinischen Bild zwischen ESBL-E Bakteriämien mit K. pneumoniae und Bakteriämien mit E. coli. Bakteriämien mit K. pneumoniae bieten ein weitaus schwerwiegenderes klinisches Bild und sind mit anderen Risikofaktoren vergesellschaftet als Bakteriämien mit E. coli. Behandlungs- und Präventionsstrategien sollten dementsprechend angepasst werden.Infections with extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL-E) are associated with increased mortality. Outcome differences due to various species of ESBL-E or ESBL genotypes are not well investigated. We conducted a cohort study to assess risk factors for mortality in cases of ESBL-E bacteremia (K. pneumoniae or E. coli) and the risk factors for sepsis with organ failure. All consecutive patients of our institution from 2008 to 2011 with bacteremia due to ESBL-E were included. Basic epidemiological data, underlying comorbidities, origin of bacteremia, severity of sepsis and delay of appropriate anti-infective treatment were collected. Isolates were PCR- screened for the presence of ESBL genes and plasmid-mediated AmpC β-lactamases. Cox proportional hazard regression on mortality and multivariable logistic regression on risk factors for sepsis with organ failure was conducted. 219 cases were included in the analysis: 73.1% due to E. coli, 26.9% due to K. pneumoniae. There was no significant difference in hospital mortality (ESBL-E. coli, 23.8% vs. ESBL-K. pneumoniae 27.1%, p=0.724). However, the risk of sepsis with organ failure was associated in cases of K. pneumoniae bacteremia (OR 4.5, p<0.001) and patients with liver disease (OR 3.4, p=0.004) or renal disease (OR 6.8, p<0.001). We found significant differences in clinical presentation of ESBL-E bacteremia due to K. pneumoniae compared to E. coli. As K. pneumoniae cases showed a more serious clinical presentation as E. coli cases and were associated with different risk factors, treatment and prevention strategies should be adjusted accordingly

    Describing the FPGA-Based Hardware Architecture of Systemic Computation (HAoS)

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    his paper presents HAoS, the first hardware architecture of the bio-inspired computational paradigm known as Systemic Computation (SC). SC was designed to support the modelling of biological processes inherently by defining a massively parallel non-conventional computer architecture and a model of natural behaviour. In this work we describe a novel custom digital design, which addresses the SC architecture parallelism requirement by exploiting the inbuilt parallelism of a Field Programmable Gate Array (FPGA) and by using the highly efficient matching capability of a Ternary Content Addressable Memory (TCAM). Basic processing capabilities are embedded in HAoS in order to minimize time-demanding data transfers. Its custom instruction set can be expanded based on user requirements, since the optional use of a CPU provides high-level processing support if required. We demonstrate a functional simulation-verified prototype, which takes into consideration programmability and scalability, and review various communication interfaces between HAoS and the CPU. Analysis shows that the proposed architecture provides an effective solution in terms of efficiency versus flexibility trade-off and can potentially outperform prior implementations

    Local and Global relations between the number of contacts and density in monodisperse sphere packs

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    The topological structure resulting from the network of contacts between grains (\emph{contact network}) is studied for large samples of monosized spheres with densities (fraction of volume occupied by the spheres) ranging from 0.59 to 0.64. We retrieve the coordinates of each bead in the pack and we calculate the average coordination number by using three different methods. We show that, in the range of density investigated, the coordination number is larger than 4 and it increases with the packing fraction. At local level we also observe a positive correlation between local packing fraction and number of neighbors. We discover a dependence between the local densities of configurations with few neighbors in contact and the global sample-denities. This might indicate that local configurations with small number of neighbors are able to deform plastically when the sample is compactifying. PACS: 45.70.-n, Granular Systems; 45.70.Cc, Static sandpiles; Granular Compaction.Comment: 10 pages, 6 figure

    Eddy current effects in plain and hollow cylinders spinning inside homogeneous magnetic fields: Application to magnetic resonance

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    International audienceWe present a thorough analysis of eddy currents that develop in a rectangular cross section toroid rotating in a uniform magnetic field. The slow rotation regime is assumed. Compact expressions for the current density, the total dissipated power, and the braking torque are given. Examination of the topology of current lines reveals that depending upon the relative dimensions of the side and length of the toroid two different regimes exist. The conditions of existence of the two regimes are analytically established. In view of nuclear magnetic resonance (NMR) applications, we derive the angular variation of the magnetic field created by eddy currents and lay down the formalism necessary for calculating the effect of this field on the NMR spectra of the conductor itself or of a sample co-rotating with the conductor, a situation encountered when dealing with rotating detectors. Examples of calculations for cases of practical interest are presented. The theory is confronted with available data, and we give guidelines for the design of optimized rotating micro-coils

    Involvement of Reactive Oxygen Species (ROS) inskeletal muscle function during ageing: Study in amodel of isolated single skeletal muscle fibre

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    [ES] Suplemento de la revista Free Radical Biology and Medicine: Involvement of Reactive Oxygen Species (ROS) inskeletal muscle function during ageing: Study in amodel of isolated single skeletal muscle fibre

    Redox proteomic analysis of the gastrocnemius muscle from adult and old mice.

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    The data provides information in support of the research article, "Differential Cysteine Labeling and Global Label-Free Proteomics Reveals an Altered Metabolic State in Skeletal Muscle Aging", Journal of Proteome Research, 2014, 13 (11), 2008-21 [1]. Raw data is available from ProteomeXchange [2] with identifier PDX001054. The proteome of gastrocnemius muscle from adult and old mice was analyzed by global label-free proteomics and the relative quantification of specific reduced and reversibly oxidized Cysteine (Cys) residues was performed using Skyline [3]. Briefly, reduced Cysteine (Cys) containing peptides was alkylated using N-ethylmalemide (d0-NEM). Samples were desalted and reversibly oxidized Cys residues were reduced using tris(2-carboxyethyl)phosphine (TCEP) and the newly formed reduced Cys residues were labeled with heavy NEM( d5-NEM). Label-free analysis of the global proteome of adult (n=5) and old (n=4) gastrocnemius muscles was performed using Peaks7™ mass spectrometry data analysis software [4]. Relative quantification of Cys containing peptides that were identified as reduced (d(0) NEM labeled) and reversibly oxidized d(5)-NEM labeled was performed using the intensity of their precursor ions in Skyline. Results indicate that muscles from old mice show reduced redox flexibility particularly in proteins involved in the generation of precursor metabolites and energy metabolism, indicating a loss in the flexibility of the redox energy response
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