1,313 research outputs found

    Novel extractant impregnated resin for preconcentration and determination of uranium from environmental samples

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    A novel method based on impregnation of Amberlite XAD-4 with extractant isonitroso-4-methyl-2-pentanone (IMP) has been developed for U6 + extraction and determination in various samples. The prepared extractant im- pregnated resin (EIR) sorbent was characterized by the field emission scanning electron microscope. The sorbent was packed in a glass column and investigated for various parameters such as pH, eluent, sample and eluent flow rates to optimize sorption desorption conditions for U6+. U6+ is quantitatively determined at pH 4 with flow rate 2 mL/min which showed recovery of 98.9%. The sorption behaviour of U6 + by EIR was also studied using different equilibrium isotherms and kinetic models and the experimental data confirmed that it follows Freundlich iso- therm and Weber-Morris pore diffusion kinetic model. The investigation of foreign ions influence on U6+ sorp- tion showed least interference and thus, facilitated its extraction and determination in Uranmicrolite (leachate) ore tailing, synthetic mixtures and spiked water samples. The detection limit was 0.41 μg/L while the limit of quantification as 1.35 μg/L made the method quite accurate

    Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

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    The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum
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