52 research outputs found

    A First Search for coincident Gravitational Waves and High Energy Neutrinos using LIGO, Virgo and ANTARES data from 2007

    Get PDF
    We present the results of the first search for gravitational wave bursts associated with high energy neutrinos. Together, these messengers could reveal new, hidden sources that are not observed by conventional photon astronomy, particularly at high energy. Our search uses neutrinos detected by the underwater neutrino telescope ANTARES in its 5 line configuration during the period January - September 2007, which coincided with the fifth and first science runs of LIGO and Virgo, respectively. The LIGO-Virgo data were analysed for candidate gravitational-wave signals coincident in time and direction with the neutrino events. No significant coincident events were observed. We place limits on the density of joint high energy neutrino - gravitational wave emission events in the local universe, and compare them with densities of merger and core-collapse events.Comment: 19 pages, 8 figures, science summary page at http://www.ligo.org/science/Publication-S5LV_ANTARES/index.php. Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p120000

    Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

    Get PDF
    A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

    Ionic liquid-modified multi-walled carbon nanotube paste electrode for cadmium and lead ion determinations

    No full text
    The detection of trace heavy metal ions is important in monitoring water quality, a vital freshwater source. This study presents the preparation of a multi-walled carbon nanotube (MWCNTs) paste electrode using a pasting mixture of 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid ([Bmim][PF6] IL) and paraffin oil for the determination of Cd2+ and Pb2+. Scanning electron microscopy, Fourier-transform infrared spectroscopy, and Raman spectroscopy were applied to characterize the paste composites. The electrochemical behavior of the fabricated electrodes was analyzed by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) techniques. The [Bmim][PF6]-MWCNTs electrode showed enhanced sensitivity for Cd2+ and Pb2+ detections over linear sweep anodic stripping voltammetry (LSASV) performances. Experimental results showed that the MWCNTs-IL-1 electrode using a pasting mixture of 10 μL of [Bmim][PF6] and 190 μL of paraffin oil was the most suitable for Cd2+ and Pb2+ determinations. The LSASV conditions for Cd2+ and Pb2+ analysis at the MWCNTs-IL-1 electrode were optimized, including the deposition potential, deposition time, and pH of the working solution. The stripping peak currents were linearly correlated with the concentration ranges of Cd2+ (1–35 μg/L) and Pb2+ (1–90 μg/L) for both individual and simultaneous determinations. The MWCNTs-IL-1 electrode exhibited high repeatability, reproducibility, and stability over a 30-day storage period. The real applicability of the MWCNTs-IL-1 electrode was demonstrated by successful determinations of Cd2+ and Pb2+ concentrations in tap water and surface water samples, which agreed with the results obtained by inductively coupled plasma mass spectrometry

    Вплив концентрації графенових нанопластинок на теплопровідність силіконової термопасти

    No full text
    Ми повідомляємо про ефективний шлях до підвищення теплопровідності силіконової термопасти без погіршення її сумісності за рахунок використання високої теплопровідності та механічної гнучкості/пластичності графенових матеріалів. Силіконові термопасти, що містять графенові нанопластинки (ГНП), готувалися із застосуванням високоенергетичного помелу в кульовому млині. Зображення СЕМ показали, що ГНП були добре дисперговані у базовій термопасті. Досліджена теплопровідність термопасти. Отримані результати показали, що ГНП ефективні для підвищення теплопровідності термопаст. Найвище підвищення теплопровідності до 59 % було отримано для термопасти, що містить 0,75 об. % ГНП. Таке підвищення можна віднести до високої теплопровідності ГНП, хорошої сумісності та рівномірного диспергування ГНП у термопасті. Теплопровідність термопасти з більш високою концентрацією ГНП 1 об. % зменшувалася за рахунок утворення кластерів ГНП. Використовуючи модель Чу з підбором міжфазної термостійкості (Rk), ми виявили, що підвищення теплопровідності термопасти стосується термостійкості Rk між ГНП та матрицею термопасти. Найкращий спосіб поліпшити теплопровідність термопасти – це зменшити Rk. Отримані результати продемонстрували переваги ГНП в термопастах для розсіювання тепла в електронних пристроях високої потужності.We herein report a facile route to improve the thermal conductivity of silicone thermal grease without deteriorating its conformability via exploitation of outstanding thermal conductivity and mechanical flexibility/ductility of graphene materials. The silicone thermal greases containing GNPs were prepared by using the high-energy ball milling process. The SEM images proved that GNPs were well dispersed in the base grease. The thermal conductivity of the thermal greases was investigated and presented. The obtained results demonstrated that GNPs are efficient for the thermal conductivity enhancement of the thermal grease. The highest thermal conductivity enhancement up to 59 % was obtained with the grease containing 0.75 vol. % GNPs. The enhancement could be attributed to high thermal conductivity of GNPs, the good compatibility and uniform dispersion of GNPs in the thermal grease. The thermal conductivity of the thermal grease with higher GNPs concentration of 1 vol. % was decreased due to the formation of GNPs clusters. By using Chu’s model with the interfacial thermal resistance (Rk) fitting, we found that the thermal conductivity enhancement of the thermal grease concerns to the Rk between GNPs and the grease matrix. The best way to improve the thermal conductivity of the thermal grease is to reduce the Rk. The obtained results demonstrated the advantages of GNP in the thermal greases for the heat dissipation in high power electronic devices
    corecore