3,217 research outputs found

    Stellar matter in the Quark-Meson-Coupling Model with neutrino trapping

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    The properties of hybrid stars formed by hadronic and quark matter in β\beta-equilibrium are described by appropriate equations of state (EoS) in the framework of the quark meson coupling (QMC) model. In the present work we include the possibility of trapped neutrinos in the equation of state and obtain the properties of the related hybrid stars. We use the quark meson coupling model for the hadron matter and two possibilities for the quark matter phase, namely, the unpaired quark phase and the color-flavor locked phase. The differences are discussed and a comparison with other relativistic EoS is done.Comment: Reference added, accepted in PR

    Kaon condensation in the quark-meson coupling model and compact stars

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    The properties of neutron stars constituted of a crust of hadrons and an internal part of hadrons and kaon condensate are calculated within the quark-meson-coupling model. We have considered stars with nucleons only in the hadron phase and also stars with hyperons as well. The results are compared with the ones obtained from the non-linear Walecka model for the hadronic phase.Comment: 10 pages, 6 figure

    Warm and dense stellar matter under strong magnetic fields

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    We investigate the effects of strong magnetic fields on the equation of state of warm stellar matter as it may occur in a protoneutron star. Both neutrino free and neutrino trapped matter at a fixed entropy per baryon are analyzed. A relativistic mean field nuclear model, including the possibility of hyperon formation, is considered. A density dependent magnetic field with the magnitude 101510^{15} G at the surface and not more than 3×10183\times 10^{18} G at the center is considered. The magnetic field gives rise to a neutrino suppression, mainly at low densities, in matter with trapped neutrinos. It is shown that an hybrid protoneutron star will not evolve to a low mass blackhole if the magnetic field is strong enough and the magnetic field does not decay. However, the decay of the magnetic field after cooling may give rise to the formation of a low mass blackhole.Comment: 17 pages, 10 figures, 3 tables, submitted to Phys. Rev.

    Probing the superconducting ground state of ZrIrSi: A μ\muSR study

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    The superconducting ground state of newly reported ZrIrSi is probed by means of μ\muSR technique along with resistivity measurement. The occurrence of superconductivity at TCT_\mathrm{C} = 1.7 K is confirmed by resistivity measurement. ZF-μ\muSR study revealed that below TCT_\mathrm{C}, there is no spontaneous magnetic field in the superconducting state, indicates TRS is preserved in case of ZrIrSi. From TF-μ\muSR measurement, we have estimated the superfluid density as a function of temperature, which is described by an isotropic ss-wave model with a superconducting gap 2Δ(0)/kBTC2\Delta(0)/k_\mathrm{B}T_\mathrm{C} = 5.1, indicates the presence of strong spin-orbit coupling. {\it Ab-initio} electronic structure calculation indicates that there are four bands passing through the Fermi level, forming four Fermi surface pockets. We find that the low-energy bands are dominated by the 4d4d-orbitals of transition metal Zr, with substantially lesser weight from the 5d5d-orbitals of the Ir-atoms.Comment: 6 pages, 4 figure

    Investigation of Superconducting Gap Structure in HfIrSi using muon spin relaxation/rotation

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    Appearance of strong spin-orbit coupling (SOC) is apparent in ternary equiatomic compounds with 5dd-electrons due to the large atomic radii of transition metals. SOC plays a significant role in the emergence of unconventional superconductivity. Here we examined the superconducting state of HfIrSi using magnetization, specific heat, zero and transverse-field (ZF/TF) muon spin relaxation/rotation (μ\muSR) measurements. Superconductivity is observed at TCT_\mathrm{C} = 3.6 K as revealed by specific heat and magnetization measurements. From the TFμ-\muSR analysis it is clear that superfluid density well described by an isotropic BCS type ss-wave gap structure. Furthermore, from TFμ-\muSR data we have also estimated the superconducting carrier density nsn_\mathrm{s} = 6.6 ×\times1026^{26}m3^{-3}, London penetration depth λL(0)\lambda_{L}(0) = 259.59 nm and effective mass mm^{*} = 1.57 mem_{e}. Our zero-field muon spin relaxation data indicate no clear sign of spontaneous internal field below TCT_\mathrm{C}, which implies that the time-reversal symmetry is preserved in HfIrSi. Theoretical investigation suggests Hf and Ir atoms hybridize strongly along the cc-axis of the lattice, which is responsible for the strong three-dimensionality of this system which screens the Coulomb interaction. As a result despite the presence of correlated dd-electrons in this system, the correlation effect is weakened, promoting electron-phonon coupling to gain importance.Comment: 8 pages, 4 figure

    Mineral Beneficiation Potentialities Archaean Limestone for Cement Manufacture

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    The highly contaminated and deformed coarse crystalline Archaean limestone along with cement grade limestone is being utilized by nearly 14 major cement plants with an installed capacity of 17.36 million tonnes per annum in India, distributed mainly in the states of Rajasthan, Orissa, Jharkhand, Andhra pradesh, Tamilnadu, Karnataka, Kerala etc. National Council for Cement and Builing Materials (NCB). India has undertaken studies on the mineral beneficiation potentialities for upgradation of the above limestone exclusively on dry basis, based on the physico-mechanical properties of limestone sample collected from a working mine of an existing cement plant, is subjected to crushing, grinding with variable time period and its classification through sieving and air classifier. The results are highly encouraging in enhancing CaO content and reducting SiO2 content in limestone and thus to make it suitable for cement manufacture. The ultimate impact of such studies is that extended life of cement raw material resources, better environment and viability of old cement plant

    Yoga for treating urinary incontinence in women

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    Background Urinary incontinence in women is associated with poor quality of life and difficulties in social, psychological and sexual functioning. The condition may affect up to 15% of middle-aged or older women in the general population. Conservative treatments such as lifestyle interventions, bladder training and pelvic floor muscle training (used either alone or in combination with other interventions) are the initial approaches to the management of urinary incontinence. Many women are interested in additional treatments such as yoga, a system of philosophy, lifestyle and physical practice that originated in ancient India. Objectives To assess the effects of yoga for treating urinary incontinence in women. Search methods We searched the Cochrane Incontinence and Cochrane Complementary Medicine Specialised Registers. We searched the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP) and ClinicalTrials.gov to identify any ongoing or unpublished studies. We handsearched Proceedings of the International Congress on Complementary Medicine Research and the European Congress for Integrative Medicine. We searched the NHS Economic Evaluation Database for economic studies, and supplemented this search with searches for economics studies in MEDLINE and Embase from 2015 onwards. Database searches are up-to-date as of 21 June 2018. Selection criteria Randomised controlled trials in women diagnosed with urinary incontinence in which one group was allocated to treatment with yoga. Data collection and analysis Two review authors independently screened titles and abstracts of all retrieved articles, selected studies for inclusion, extracted data, assessed risk of bias and evaluated the certainty of the evidence for each reported outcome. Any disagreements were resolved by consensus. We planned to combine clinically comparable studies in Review Manager 5 using random-effects meta-analysis and to carry out sensitivity and subgroup analyses. We planned to create a table listing economic studies on yoga for incontinence but not carry out any analyses on these studies. Main results We included two studies (involving a total of 49 women). Each study compared yoga to a different comparator, therefore we were unable to combine the data in a meta-analysis. A third study that has been completed but not yet fully reported is awaiting assessment. One included study was a six-week study comparing yoga to a waiting list in 19 women with either urgency urinary incontinence or stress urinary incontinence. We judged the certainty of the evidence for all reported outcomes as very low due to performance bias, detection bias, and imprecision. The number of women reporting cure was not reported. We are uncertain whether yoga results in satisfaction with cure or improvement of incontinence (risk ratio (RR) 6.33, 95% confidence interval (CI) 1.44 to 27.88; an increase of 592 from 111 per 1000, 95% CI 160 to 1000). We are uncertain whether there is a difference between yoga and waiting list in condition-specific quality of life as measured on the Incontinence Impact Questionnaire Short Form (mean difference (MD) 1.74, 95% CI -33.02 to 36.50); the number of micturitions (MD -0.77, 95% CI -2.13 to 0.59); the number of incontinence episodes (MD -1.57, 95% CI -2.83 to -0.31); or the bothersomeness of incontinence as measured on the Urogenital Distress Inventory 6 (MD -0.90, 95% CI -1.46 to -0.34). There was no evidence of a difference in the number of women who experienced at least one adverse event (risk difference 0%, 95% CI -38% to 38%; no difference from 222 per 1000, 95% CI 380 fewer to 380 more). The second included study was an eight-week study in 30 women with urgency urinary incontinence that compared mindfulness-based stress reduction (MBSR) to an active control intervention of yoga classes. The study was unblinded, and there was high attrition from both study arms for all outcome assessments. We judged the certainty of the evidence for all reported outcomes as very low due to performance bias, attrition bias, imprecision and indirectness. The number of women reporting cure was not reported. We are uncertain whether women in the yoga group were less likely to report improvement in incontinence at eight weeks compared to women in the MBSR group (RR 0.09, 95% CI 0.01 to 1.43; a decrease of 419 from 461 per 1000, 95% CI 5 to 660). We are uncertain about the effect of MBSR compared to yoga on reports of cure or improvement in incontinence, improvement in condition-specific quality of life measured on the Overactive Bladder Health-Related Quality of Life Scale, reduction in incontinence episodes or reduction in bothersomeness of incontinence as measured on the Overactive Bladder Symptom and Quality of Life-Short Form at eight weeks. The study did not report on adverse effects. Authors' conclusions We identified few trials on yoga for incontinence, and the existing trials were small and at high risk of bias. In addition, we did not find any studies of economic outcomes related to yoga for urinary incontinence. Due to the lack of evidence to answer the review question, we are uncertain whether yoga is useful for women with urinary incontinence. Additional, well-conducted trials with larger sample sizes are needed
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