186 research outputs found

    A1A_1 theory of weights for rough homogeneous singular integrals and commutators

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    Quantitative A1AA_1-A_\infty estimates for rough homogeneous singular integrals TΩT_{\Omega} and commutators of BMOBMO symbols and TΩT_{\Omega} are obtained. In particular the following estimates are proved: % TΩLp(w)cn,pΩL[w]A11p[w]A1+1pfLp(w) \|T_\Omega \|_{L^p(w)}\le c_{n,p}\|\Omega\|_{L^\infty} [w]_{A_1}^{\frac{1}{p}}\,[w]_{A_{\infty}}^{1+\frac{1}{p'}}\|f\|_{L^p(w)} % and % [b,TΩ]fLp(w)cn,pbBMOΩL[w]A11p[w]A2+1pfLp(w), \| [b,T_{\Omega}]f\|_{L^{p}(w)}\leq c_{n,p}\|b\|_{BMO}\|\Omega\|_{L^{\infty}} [w]_{A_1}^{\frac{1}{p}}[w]_{A_{\infty}}^{2+\frac{1}{p'}}\|f\|_{L^{p}\left(w\right)}, % for 1<p<1<p<\infty and 1/p+1/p=11/p+1/p'=1.Comment: 19 page

    Removal of Cd (II) from aqueous solutions by batch and continuous process using chitosan sulfate dispersed in a calcium alginate hydrogel

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    A novel chitosan sulfate (ChS) which is insoluble at acidic pHs was synthesized and then dispersed in calcium alginate hydrogel beads to be used to remove Cd(II) from aqueous solutions at acidic pHs using a batch process and a continuous process. By batch wise experiments, it was found that the equilibrium adsorption capacity of the Alg-ChS beads increase with the increase in the initial concentration of Cd; however, the percentage of Cd removal decreased.The Freundlich model had the best fit to the experimental adsorption equilibrium data. The adsorption rate of Cd onto Alg-ChS beads followed the kinetic model of pseudo-second order and the time to reach equilibrium increased slightly with increasing initial concentration of Cd(II). The removal of Cd using a fixed bed column (continuous process) packed with the Alg-ChS beads had a much higher efficiencythan the Batch process. An adsorption mechanism of Cd(II) onto the Alg-ChS beads was proposed using the FTIR, and XPS spectra of samples of Cd(II) adsorbed onto ChS and the mechanisms of adsorption of metals by alginate and chitosan proposed by other authors

    Performance of the CMS Cathode Strip Chambers with Cosmic Rays

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    The Cathode Strip Chambers (CSCs) constitute the primary muon tracking device in the CMS endcaps. Their performance has been evaluated using data taken during a cosmic ray run in fall 2008. Measured noise levels are low, with the number of noisy channels well below 1%. Coordinate resolution was measured for all types of chambers, and fall in the range 47 microns to 243 microns. The efficiencies for local charged track triggers, for hit and for segments reconstruction were measured, and are above 99%. The timing resolution per layer is approximately 5 ns

    Performance and Operation of the CMS Electromagnetic Calorimeter