1,063 research outputs found

    Sustainable Solid Waste Management in Leather and Textile Industry: Leather & Textile Waste Fibre-Polymer Composite and Nanocomposite – Overview and Review

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    Proper disposal methods and solid waste management are necessary for all the processing industries such as leather, textile and chemical industry. In this regard, the present paper reviews in detail about the leather and textile waste fibre-polymer composites and nanocomposites as a viable solid waste management strategy. In the paper, several published papers and patents available in this area are reviewed in detail. This approach adopts confinement of leather or textile waste fibres in a polymer matrix as a composite. Nanocomposites of leather waste fibre and polymer with nano-particle reinforcement have been reported to have enhanced physical and other properties. This would not only solve the problem of the disposal issue regarding leather solid wastes containing leather or textile waste fibres, but also provide versatile composite or nanocomposite materials as “Wealth from Waste Approach”. The unique feature of the present analysis and the review paper is that both leather and textile waste management have been covered in the present approach for the first time

    Optical observations of the bright long duration peculiar GRB 021004 afterglow

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    The CCD magnitudes in Johnson B,VB,V and Cousins RR and II photometric passbands are determined for the bright long duration GRB 021004 afterglow from 2002 October 4 to 16 starting ∌\sim 3 hours after the γ−\gamma-ray burst. Light curves of the afterglow emission in BB,VV,RR and II passbands are obtained by combining these measurements with other published data. The earliest optical emission appears to originate in a revese shock. Flux decay of the afterglow shows a very uncommon variation relative to other well-observed GRBs. Rapid light variations, especially during early times (Δt<2\Delta t < 2 days) is superposed on an underlying broken power law decay typical of a jetted afterglow. The flux decay constants at early and late times derived from least square fits to the light curve are 0.99±0.050.99\pm0.05 and 2.0±0.22.0\pm0.2 respectively, with a jet break at around 7 day. Comparison with a standard fireball model indicates a total extinction of E(B−V)=0.20E(B-V)=0.20 mag in the direction of the burst. Our low-resolution spectra corrected for this extinction provide a spectral slope ÎČ=0.6±0.02\beta = 0.6\pm0.02. This value and the flux decay constants agree well with the electron energy index p∌2.27p\sim 2.27 used in the model. The derived jet opening angle of about 7∘7^{\circ} implies a total emitted gamma-ray energy EÎł=3.5×1050E_{\gamma} = 3.5\times10^{50} erg at a cosmological distance of about 20 Gpc. Multiwavelength observations indicate association of this GRB with a star forming region, supporting the case for collapsar origin of long duration GRBs.Comment: 19 pages, 3 figures, BASI, 31, 1

    Multi-messenger observations of a binary neutron star merger

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    On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

    Observation of the doubly charmed baryon decay Ξcc++→Ξcâ€Č+π+

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    The Ξcc++→Ξcâ€Č+π+ decay is observed using proton-proton collisions collected by the LHCb experiment at a centre-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4 fb−1. The Ξcc++→Ξcâ€Č+π+ decay is reconstructed partially, where the photon from the Ξcâ€Č+→Ξc+Îł decay is not reconstructed and the pK−π+ final state of the Ξc+ baryon is employed. The Ξcc++→Ξcâ€Č+π+branching fraction relative to that of the Ξcc++→Ξc+π+ decay is measured to be 1.41 ± 0.17 ± 0.10, where the first uncertainty is statistical and the second systematic. [Figure not available: see fulltext.

    Test of lepton universality in b→sℓ+ℓ−b \rightarrow s \ell^+ \ell^- decays

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    The first simultaneous test of muon-electron universality using B+→K+ℓ+ℓ−B^{+}\rightarrow K^{+}\ell^{+}\ell^{-} and B0→K∗0ℓ+ℓ−B^{0}\rightarrow K^{*0}\ell^{+}\ell^{-} decays is performed, in two ranges of the dilepton invariant-mass squared, q2q^{2}. The analysis uses beauty mesons produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 fb−1\mathrm{fb}^{-1}. Each of the four lepton universality measurements reported is either the first in the given q2q^{2} interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-046.html (LHCb public pages

    Study of charmonium and charmonium-like contributions in B+ → J/ψηK+ decays

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    A study of B+→ J/ψηK+ decays, followed by J/ψ → ÎŒ+Ό− and η → γγ, is performed using a dataset collected with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV, corresponding to an integrated luminosity of 9 fb−1. The J/ψη mass spectrum is investigated for contributions from charmonia and charmonium-like states. Evidence is found for the B+→ (ψ2(3823) → J/ψη)K+ and B+→ (ψ(4040) → J/ψη)K+ decays with significance of 3.4 and 4.7 standard deviations, respectively. This constitutes the first evidence for the ψ2(3823) → J/ψη decay
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