13,517 research outputs found

    Composition of primary cosmic rays near the knee

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    The size dependence of high energy muons and the size spectrum obtained in the air shower experiment suggest that the mean mass of cosmic rays remains nearly constant at approx 15 up to 5 x 1000,000 GeV and becomes one beyond. The composition model in which nuclei are removed spectrum steepens at 6.7 x 10 power GeV due to leakage from the galaxy, which explains the data which are consistent with data from other experiments

    Measurement of the iron spectrum from 60 to 200 GeV per nucleon

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    The high energy gas Cerenkov Spectrometer (HEGCS) was flown by balloon from Palestine, Texas on September 30, 1983. The instrument maintained an altitude of 118,000 ft (4.7 g/sq cms) for 6 hours. Details of the ongoing data analysis and preliminary results on the Fe spectrum to 10 to the 13th power eV/nucleus are given

    Broadband study of blazar 1ES 1959+650 during flaring state in 2016

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    Aim : The nearby TeV blazar 1ES 1959+650 (z=0.047) was reported to be in flaring state during June - July 2016 by Fermi-LAT, FACT, MAGIC and VERITAS collaborations. We studied the spectral energy distributions (SEDs) in different states of the flare during MJD 57530 - 57589 using simultaneous multiwaveband data to understand the possible broadband emission scenario during the flare. Methods : The UV/optical and X-ray data from UVOT and XRT respectively on board Swift and high energy γ\gamma-ray data from Fermi-LAT are used to generate multiwaveband lightcurves as well as to obtain high flux states and quiescent state SEDs. The correlation and lag between different energy bands is quantified using discrete correlation function. The synchrotron self Compton (SSC) model was used to reproduce the observed SEDs during flaring and quiescent states of the source. Results : A decent correlation is seen between X-ray and high energy γ\gamma-ray fluxes. The spectral hardening with increase in the flux is seen in X-ray band. The powerlaw index vs flux plot in γ\gamma-ray band indicates the different emission regions for 0.1 - 3 GeV and 3-300 GeV energy photons. Two zone SSC model satisfactorily fits the observed broadband SEDs. The inner zone is mainly responsible for producing synchrotron peak and high energy γ\gamma-ray part of the SED in all states. The second zone is mainly required to produce less variable optical/UV and low energy γ\gamma-ray emission. Conclusions : Conventional single zone SSC model does not satisfactorily explain broadband emission during observation period considered. There is an indication of two emission zones in the jet which are responsible for producing broadband emission from optical to high energy γ\gamma-rays.Comment: 11 pages, 12 figures, Accepted in A&

    Measuring gender norms about relationships in early adolescence : results from the global early adolescent study

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    Introduction: Gender norms are increasingly recognized as drivers of health and wellbeing. While early adolescence constitutes a critical window of development, there is limited understanding about how adolescents perceive gender relations across different cultural settings. This study used a mixed-method approach, grounded in the voices of young people around the world, to construct and test a cross-cultural scale assessing the perceptions of gender norms regulating romantic relationships between boys and girls in early adolescence. Methods: The study draws on the Global Early Adolescent study (GEAS), a study focusing on gender norms and health related outcomes over the course of adolescence in urban poor settings worldwide. In-depth interviews were first conducted among approximately 200 adolescents between 10-14 years in seven sites across 4 continents to identify common scripts guiding romantic relations in early adolescence. These scripts were then transformed into a multidimensional scale. The scale was tested among 120 adolescents in each of 14 GEAS sites, followed by a second pilot among 75 adolescents in six sites. We evaluated the psychometric criteria of each subscale using principal component analysis, and parallel analysis, followed by exploratory factor analysis to guide the selection of a more parsimonious set of items. Results: Results suggested a two-factor structure, consisting of an "adolescent romantic expectations" subscale and a "Sexual Double Standard" subscale. Both subscales yielded high internal validity in each site, with polychoric Cronbach alpha values above 0.70 with the exception of Kinshasa for the adolescent romantic expectations scale (0.64) and Hanoi for the sexual double standard scale (0.61). Conclusion: This study reveals common perceptions of gendered norms about romantic engagement in early adolescence, normative for both sexes, but socially valued for boys while devaluated for girls. The findings illustrate that social hierarchies of power in romantic relationships form early in adolescence, regardless of cultural setting

    Phase transition and hybrid star in a SU(2) chiral sigma model

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    We use a modified SU(2) chiral sigma model to study nuclear matter at high density using mean field approach. We also study the phase transition of nuclear matter to quark matter in the interior of highly dense neutron stars. Stable solutions of Tolman-Oppenheimer-Volkoff equations representing hybrid stars are obtained with a maximum mass of 1.69 MM_{\odot}, radii around 9.3 kms and a quark matter core constituting nearly 55-85 % of the star radii.Comment: 19 pages, 9 figures, accepted for Mod. Phys. Letts.

    Hepatitis C virus infection is the major cause of severe liver disease in India

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    The present study describes the status of hepatitis C virus infection in 167 patients with severe forms of liver diseases in India. The anti-HCV positivity rate was recorded as 43%, 47% and 42% in patients with FHF, SAHF and CAH respectively. HBV and HCV coinfection was recorded in 28% of FHF, 43% of SAHF and 75% of the CAH cases. Superinfection of HCV in HBsAg carriers was recorded in 54% cases of FHF, 60% of SAHF and 42% of the CAH. None of these 167 patients was positive of HAV-IgM. Further, 27.7% of FHF, 26.4% of SAHF and 15.2% of CAH cases were neither HBV nor HCV markers positive. These can be labelled as non-A, non-B and nonC infections

    Significance of anti-pre-S antibodies in patients with fulminant hepatic failure

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    Anti-pre-S antibody was tested in 38 sera from patients with fulminant hepatitis (positive for HBsAg and/or IgM anti-HBc) using a specific solid phase enzyme linked immunosorbent assay (ELISA). Anti-pre-S activity was detected in 50 percent sera samples positive for HBsAg but negative for IgM antiHBc. There were 12.5% sera positive for both HBsAg as well as IgM anti-HBc and 75% sera negative for HBsAg but positive for IgM anti-HBc. The prevalence of HBV-specific DNA-polymerase activity was high in all the three groups whereas anti-HBs positivity was low. Anti-pre-S activity was observed both in the presence as well as in the absence of DNA-polymerase activity. High-anti-pre-S level in fulminant hepatitis B patients was assumed to be implicated in the fast clearance of HBsAg from circulation

    Role of Mineralogy, Mineral Chemistry and Geochemistry in Mineral Processing : A case study for High Phosphorous manganese ores of Nishikhal, South Orissa, India

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    Conformable manganese ore bands are present in the khond-alite suite of rocks belonging to the Eastern Ghats Complex of South Orissa,India. The ores cart be classified as high-grade, siliceous and ferruginous. Cryptomelane, romanechite, pyrolusite, jacobsite, hausmannite, braunite, lithiophorite, birnessite and pyrophanite represent the manganese minerals. Goethite, limonite, graphite, hematite, magnetite are the associated opaque gangue minerals while quartz,orthoclase, hyalophane, garnet, kaolinite, apatite, collophane,. fibrolite,zircon, biotite and muscovite are the silicate gangue minerals recorded in these ores. Optical microscopic and Electron Probe Microanalysis studies revealed that the phosphorous, in these ores, present in the form of (i) apatite inclusions within qua-rtz, orthoclase and garnet, (ii) amorphous calcium phos-phate (collophane) within the voids of garnet, (iii) ads-orbed component within the manganese oxide and silicate phases as well as in the iron oxide phase (goethite) Geochemical studies indicated that high amount of phos-phorous is linked with ferruginous manganese ores. Regression analysis of the geochemical data suggests a strong positive correlation between P-Fe and P-Mn. Magnetic separation studies on low- and off- grade bulk manganese samples, indicated that the phosphorous contributed by apatite is relatively low (4.44 to 17.76%) compared to the phosphorous held in adsorption(82.24 to 95.56%), while the contribution of phosphorous by collophane is insignificant.The above studies confirm that the association of phosphorous in Nishikhal ores is very complex. Since most of the phosphorous is in adsorption, these low and off grade ores are expected to respond well to dephosphorisation by reduction roasting followed by magnetic separation or roast alkali leaching method
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