Batch and column adsorption of cations, oxyanions and dyes on a magnetite modified cellulose-based membrane

An optimized method is presented to make magnetite (MG) modified cellulose membrane (Cell-MG) from 3-aminopropyltriethoxysilane and diethylenetriaminepentaacetic acid dianhydride functionalized waste cell fibers; (Cell-NH(2)and Cell-DTPA), and amino-modified diatomite. Functionalized Cell-NH2, Cell-DTPA fibers, and diatomite were structurally and morphologically characterized using FT-IR, Raman, and FE-SEM analysis. Amino and carboxyl group content was determined via standard volumetric methods. Response surface method was applied to rationalize the number of experiments related to Cell-MG synthesis and heavy metal ions column adsorption experiments. The effects of pH, contact time, temperature, and initial concentration of pollutants on adsorption and kinetics were studied in a batch, while initial concentration and flow rate were studied in a flow system. The calculated capacities of 88.2, 100.7, 95.8 and 78.2 mg g(-1)for Ni2+, Pb2+, Cr(VI) and As(V) ions, respectively, were obtained from Langmuir model fitting. Intra-particle diffusion as a rate-limiting step was evaluated from pseudo-second-order and Weber-Morris model fitting. Thermodynamic parameters indicated spontaneous and low endothermic processes. The results from reusability study, wastewater purification and fixed-bed column study proved the high applicability of Cell-MG. Additionally, high removal capacity of four dyes together with density functional theory and molecular interaction fields, help in the establishment of relation between the adsorption performances and contribution of non-specific and specific interactions at adsorbate/adsorbent interface

Search for CP violation using tt‾ \textrm{t}\overline{\textrm{t}} events in the lepton+jets channel in pp collisions at s \sqrt{s} = 13 TeV

Results are presented on a search for CP violation in the production and decay of top quark-antiquark pairs in the lepton+jets channel. The search is based on data from proton-proton collisions at $\sqrt{s}$ = 13 TeV, collected with the CMS detector, corresponding to an integrated luminosity of 138 fb$^{−1}$. Possible CP violation effects are evaluated by measuring asymmetries in observables constructed from linearly independent four-momentum vectors of the final-state particles. The dimensionless chromoelectric dipole moment of the top quark obtained from the observed asymmetries is measured to be 0.04 ± 0.10 (stat) ± 0.07(syst), and the asymmetries exhibit no evidence for CP-violating effects, consistent with expectations from the standard model.[graphic not available: see fulltext