Indian Institute of Technology Bombay

About: Indian Institute of Technology Bombay is a education organization based out in Mumbai, India. It is known for research contribution in the topics: Population & Thin film. The organization has 16756 authors who have published 33588 publications receiving 570559 citations.

Adsorption, photodegradation and antibacterial study of graphene???Fe3O4 nanocomposite for multipurpose water purification application

Abstract: Graphene–Fe3O4 (G–Fe3O4) composite was prepared from graphene oxide (GO) and FeCl3·6H2O by a one-step solvothermal route. The as-prepared composite was characterized by field-emission scanning electron microscopy, transmission electron microscopy, dynamic light scattering and X-ray powder diffraction. SEM analysis shows the presence of Fe3O4 spheres with size ranging between 200 and 250 nm, which are distributed and firmly anchored onto the wrinkled graphene layers with a high density. The resulting G–Fe3O4 composite shows extraordinary adsorption capacity and fast adsorption rates for the removal of Pb metal ions and organic dyes from aqueous solution. The adsorption isotherm and thermodynamics were investigated in detail, and the results show that the adsorption data was best fitted with the Langmuir adsorption isotherm model. From the thermodynamics investigation, it was found that the adsorption process is spontaneous and endothermic in nature. Thus, the as-prepared composite can be effectively utilized for the removal of various heavy metal ions and organic dyes. Simultaneously, the photodegradation of methylene blue was studied, and the recycling degradation capacity of dye by G–Fe3O4 was analyzed up to 5 cycles, which remained consistent up to ∼97% degradation of the methylene blue dye. Although iron oxide has an affinity towards bacterial cells, its composite with graphene still show antibacterial property. Almost 99.56% cells were viable when treated with Fe3O4 nanoparticle, whereas with the composite barely 3% cells survived. Later, the release of ROS was also investigated by membrane and oxidative stress assay. Total protein degradation was analyzed to confirm the effect of the G–Fe3O4 composite on E. coli cells.

A predictably selective nitration of olefin with Fe(NO3)3 and TEMPO.

Abstract: Ferric nitrate with catalytic TEMPO has been identified as a useful reagent for regio- and stereoselective nitration of a wide variety of aromatic, aliphatic, and heteroaromatic olefins. This reaction provided nitroolefins in preparatively useful yields with excellent E-selectivity. Due to its mild nature and operational simplicity, the present protocol is expected to find application in synthetic setup.

Fluctuations of charge separation perpendicular to the event plane and local parity violation in s NN = 200 GeV Au + Au collisions at the BNL Relativistic Heavy Ion Collider

Abstract: Previous experimental results based on data (∼15×106 events) collected by the STAR detector at the BNL Relativistic Heavy Ion Collider suggest event-by-event charge-separation fluctuations perpendicular to the event plane in noncentral heavy-ion collisions. Here we present the correlator previously used split into its two component parts to reveal correlations parallel and perpendicular to the event plane. The results are from a high-statistics 200-GeV Au + Au collisions data set (57×106 events) collected by the STAR experiment. We explicitly count units of charge separation from which we find clear evidence for more charge-separation fluctuations perpendicular than parallel to the event plane. We also employ a modified correlator to study the possible P-even background in same- and opposite-charge correlations, and find that the P-even background may largely be explained by momentum conservation and collective motion. © 2013 American Physical Society.

D* polarization as a probe to discriminate new physics in B --> D* tau nubar

Abstract: The confirmation of excess in ${R}_{{D}^{*}}$ at the LHCb is an indication of lepton flavor nonuniversality. Various different new physics operators and their coupling strengths, which provide a good fit to ${R}_{D}$, ${R}_{{D}^{*}}$, and ${q}^{2}$ spectra, were identified previously. In this work, we try to find angular observables in $\overline{B}\ensuremath{\rightarrow}{D}^{*}\ensuremath{\tau}\overline{\ensuremath{ u}}$ which enable us to distinguish between these new physics operators. We find that the ${D}^{*}$ polarization fraction ${f}_{L}({q}^{2})$ is a good discriminant of scalar and tensor new physics operators. The change in $⟨{f}_{L}({q}^{2})⟩$, induced by scalar and tensor operators, is about 3 times larger than the expected uncertainty in the upcoming Belle measurement.