Kinetics and thermodynamics of adsorption of red dye 40 from acidic aqueous solutions onto a novel chitosan sulfate

The kinetic and thermodynamics of adsorption of Red Dye 40 from acidic aqueous solutions onto a partially sulfated chitosan (ChS) was studied. The partially sulfated ChS was water insoluble in the pH range of 2-12. Experiments were carried out batch wise to determine the effect of pH, dye concentration, and temperature on the adsorption capacity of ChStowards Red Dye 40. It was found that the equilibrium dye-binding capacity of ChS (qe) increased with increasing initial dye concentration; however, the percentage of dye removal decreased. Dye adsorption capacity of ChS increased when the solution pH was reduced. The Langmuir model was better fitted the experimental adsorption equilibrium data, and therate of dye adsorption onto ChS follows the pseudosecond order kinetic model. The adsorption capacity of ChS was enhanced by increasing the temperature.The thermodynamic adsorption parameters, enthalpy(ΔH°), entropy (ΔS°), and Gibbs energy (ΔG°) were evaluated. The adsorption process was endothermic, and the Gibbs energy negative indicating that it occurred spontaneously

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

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

Search for the neutral Higgs bosons of the minimal supersymmetric standard model in pp collisions at root s=7 TeV with the ATLAS detector

A search for neutral Higgs bosons of the Minimal Supersymmetric Standard Model (MSSM) is reported. The analysis is based on a sample of proton-proton collisions at a centre-of-mass energy of 7TeV recorded with the ATLAS detector at the Large Hadron Collider. The data were recorded in 2011 and correspond to an integrated luminosity of 4.7 fb-1 to 4.8 fb-1. Higgs boson decays into oppositely-charged muon or τ lepton pairs are considered for final states requiring either the presence or absence of b-jets. No statistically significant excess over the expected background is observed and exclusion limits at the 95% confidence level are derived. The exclusion limits are for the production cross-section of a generic neutral Higgs boson, φ, as a function of the Higgs boson mass and for h/A/H production in the MSSM as a function of the parameters mA and tan β in the mhmax scenario for mA in the range of 90GeV to 500 GeV. Copyright CERN

Observation of associated near-side and away-side long-range correlations in √sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

Search for R-parity-violating supersymmetry in events with four or more leptons in sqrt(s) =7 TeV pp collisions with the ATLAS detector

A search for new phenomena in final states with four or more leptons (electrons or muons) is presented. The analysis is based on 4.7 fb−1 of $\sqrt{s}=7\;\mathrm{TeV}$ proton-proton collisions delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in two signal regions: one that requires moderate values of missing transverse momentum and another that requires large effective mass. The results are interpreted in a simplified model of R-parity-violating supersymmetry in which a 95% CL exclusion region is set for charged wino masses up to 540 GeV. In an R-parity-violating MSUGRA/CMSSM model, values of m 1/2 up to 820 GeV are excluded for 10 < tan β < 40

Search for high-mass resonances decaying to dilepton final states in pp collisions at s√=7 TeV with the ATLAS detector

The ATLAS detector at the Large Hadron Collider is used to search for high-mass resonances decaying to an electron-positron pair or a muon-antimuon pair. The search is sensitive to heavy neutral Z′ gauge bosons, Randall-Sundrum gravitons, Z * bosons, techni-mesons, Kaluza-Klein Z/γ bosons, and bosons predicted by Torsion models. Results are presented based on an analysis of pp collisions at a center-of-mass energy of 7 TeV corresponding to an integrated luminosity of 4.9 fb−1 in the e + e − channel and 5.0 fb−1 in the μ + μ −channel. A Z ′ boson with Standard Model-like couplings is excluded at 95 % confidence level for masses below 2.22 TeV. A Randall-Sundrum graviton with coupling k/MPl=0.1 is excluded at 95 % confidence level for masses below 2.16 TeV. Limits on the other models are also presented, including Technicolor and Minimal Z′ Models

Multiplicity and rapidity dependence of strange hadron production in pp, pPb, and PbPb collisions at the LHC

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Observation of the diphoton decay of the Higgs boson and measurement of its properties

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Precise determination of the mass of the Higgs boson and tests of compatibility of its couplings with the standard model predictions using proton collisions at 7 and 8 TeV

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Search for vector-like T quarks decaying to top quarks and Higgs bosons in the all-hadronic channel using jet substructure

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