364 research outputs found

    Photon sensitivity of superheated drop at room temperature

    Get PDF
    It has been reported so far that superheated drop detector made of R-12 at room temperature are sensitive to neutrons yet insensitive to photons. This property makes its use as one of the most useful neutron dosimeter. The photon sensitivity of R12 at room temperature when exposed to 59.54kev photons obtained from radioactive Am has been noted for the first time in our laboratory. This discovery is important nt only from the point of view of basic science but more important to the users of R12 in neutron dosimetry to take note of this in assessing the neutron dose correctly.Comment: 3pages, 1 fig. Nuclear Instruments and Method A, 2000, (accepted

    Fluctuation Cumulant Behavior for the Field-Pulse Induced Magnetisation-Reversal Transition in Ising Models

    Full text link
    The universality class of the dynamic magnetisation-reversal transition, induced by a competing field pulse, in an Ising model on a square lattice, below its static ordering temperature, is studied here using Monte Carlo simulations. Fourth order cumulant of the order parameter distribution is studied for different system sizes around the phase boundary region. The crossing point of the cumulant (for different system sizes) gives the transition point and the value of the cumulant at the transition point indicates the universality class of the transition. The cumulant value at the crossing point for low temperature and pulse width range is observed to be significantly less than that for the static transition in the same two-dimensional Ising model. The finite size scaling behaviour in this range also indicates a higher correlation length exponent value. For higher temperature and pulse width range, the transition seems to fall in a mean-field like universality class.Comment: 5 pages, 8 eps figures, thoroughly revised manuscript with new figures, accepted in Phys. Rev. E (2003

    Superheated drop as a neutron spectrometer

    Get PDF
    Superheated drops are known to vaporise when exposed to energetic nuclear radiation since the discovery of bubble chamber. As the degree of superheat increases in a given liquid, less and less energetic neutrons are required to cause nucleation. This property of superheated liquids are being utilised to develope the neutron spectromer. A new principle of neutron spectrometry using Superheated liquid are developed and the developed principle has been tested by Am-Be neutron source.Comment: 9 pages, 8 figures. accepted in Nucl.Instru.MethA,200

    Local political consolidation in Bangladesh: power, informality and patronage

    Get PDF
    During the past decade Bangladesh has shifted from a competitively clientelistic two‐party system towards a dominant‐party democracy. This article analyses how the ruling party has consolidated partisan political control at the local level. Using qualitative field data from 2004 and 2016, and drawing on a post‐structural analysis of the state, it shows how this extension of power has been achieved locally through interaction between formal and informal political initiatives. Four main types of informal activity are documented, through which the extent of local political competition has been reduced: circumvention, capture, brokerage and the creation of new organizations. These insights into the changing nature of Bangladesh's long‐standing partisan politics highlight how the state's capacity to deliver local services, allocate resources and maintain stability has been enhanced through the ruling party's control of local government structures, its elimination of political opposition, and its reshaping of local patronage arrangements

    Genetically Determined Height and Risk of Non-hodgkin Lymphoma

    Get PDF
    Although the evidence is not consistent, epidemiologic studies have suggested that taller adult height may be associated with an increased risk of some non-Hodgkin lymphoma (NHL) subtypes. Height is largely determined by genetic factors, but how these genetic factors may contribute to NHL risk is unknown. We investigated the relationship between genetic determinants of height and NHL risk using data from eight genome-wide association studies (GWAS) comprising 10,629 NHL cases, including 3,857 diffuse large B-cell lymphoma (DLBCL), 2,847 follicular lymphoma (FL), 3,100 chronic lymphocytic leukemia (CLL), and 825 marginal zone lymphoma (MZL) cases, and 9,505 controls of European ancestry. We evaluated genetically predicted height by constructing polygenic risk scores using 833 height-associated SNPs. We used logistic regression to estimate odds ratios (OR) and 95% confidence intervals (CI) for association between genetically determined height and the risk of four NHL subtypes in each GWAS and then used fixed-effect meta-analysis to combine subtype results across studies. We found suggestive evidence between taller genetically determined height and increased CLL risk (OR = 1.08, 95% CI = 1.00\u20131.17, p = 0.049), which was slightly stronger among women (OR = 1.15, 95% CI: 1.01\u20131.31, p = 0.036). No significant associations were observed with DLBCL, FL, or MZL. Our findings suggest that there may be some shared genetic factors between CLL and height, but other endogenous or environmental factors may underlie reported epidemiologic height associations with other subtypes

    Spin distribution as a probe to investigate the dynamical effects in fusion reactions

    Full text link
    The spin distributions are measured for the compound nucleus 80Sr populated in the reactions 16O+64Zn and 32S+48Ti. The comparison of the experimental results for both the systems shows that the mean Îł-ray multiplicity values for the system 32S+48Ti are lower than those for 16O+64Zn. The spin distribution of the compound nucleus populated through the symmetric channel is also found to be lower than the asymmetric channel. Present investigation directly shows the effect of entrance channel mass asymmetry on the reaction dynamics

    Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems

    Get PDF
    BackgroundHuman immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico.MethodsWe performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017.ResultsAll countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries-apart from Ecuador-across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups-the median age group among decedents ranged from 30 to 45years of age at the municipality level in Brazil, Colombia, and Mexico in 2017.ConclusionsOur subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths.Peer reviewe

    Measurement of the View the tt production cross-section using eÎŒ events with b-tagged jets in pp collisions at √s = 13 TeV with the ATLAS detector

    Get PDF
    This paper describes a measurement of the inclusive top quark pair production cross-section (σttÂŻ) with a data sample of 3.2 fb−1 of proton–proton collisions at a centre-of-mass energy of √s = 13 TeV, collected in 2015 by the ATLAS detector at the LHC. This measurement uses events with an opposite-charge electron–muon pair in the final state. Jets containing b-quarks are tagged using an algorithm based on track impact parameters and reconstructed secondary vertices. The numbers of events with exactly one and exactly two b-tagged jets are counted and used to determine simultaneously σttÂŻ and the efficiency to reconstruct and b-tag a jet from a top quark decay, thereby minimising the associated systematic uncertainties. The cross-section is measured to be: σttÂŻ = 818 ± 8 (stat) ± 27 (syst) ± 19 (lumi) ± 12 (beam) pb, where the four uncertainties arise from data statistics, experimental and theoretical systematic effects, the integrated luminosity and the LHC beam energy, giving a total relative uncertainty of 4.4%. The result is consistent with theoretical QCD calculations at next-to-next-to-leading order. A fiducial measurement corresponding to the experimental acceptance of the leptons is also presented
    • 

    corecore