Alkylation of Unsaturated Aldehyde and Allylic Bisacetate With Organomanganese Reagents in Presence of Tetrakis Acetonitrile Copper(I) Tetrafluroborate

The conjugate addition of organomanganese reagents to α,β‐unsaturated aldehydes and allylic bisacetate in presence of Me₃Si‐Cl and tetrakis acetonitrile copper(I) tetrafluroborate is described.     

Synthesis of Bioactive Pyrethroid, 3-Phenoxybenzyl 1R-trans-2, 2-Dimethyl-3-(2-chloro-1-propenyl) Cyclopropanecarboxylate

The title compound 1 has been prepared from (+)-3-carene (2) and found to have the same order of activity as its IR-cis isomer 3 reported by us earlier¹ The key intermediate methyl IR-trans-2, 2-dimethyl-3-(2-oxopropyl)cyclopropanecarboxylate (4) has been characterised.     

Plasmon‐Enhanced Photocurrent Generation from Click‐Chemically Modified Graphene

The visible‐light response of Au nanoparticles (AuNPs) assembled on rGO through different molecular bridges was investigated by transient photocurrent generation. We prepared rGO with two self‐assembled monolayers (SAMs), one linear and the other with aromatic triazoles through a click cycloaddition reaction. A fivefold photocurrent enhancement was observed for triazole linkers over the aminopropyltrimethoxysilane (APTMS) linker. Cyclic voltammetry (CV) and impedance measurements also suggest fast electron transfer on account of the low resistance offered by the click‐modified rGO surface whereby introduction of triazoles offers the efficient bridge between the donor AuNPs and acceptor rGO.     

Ultrasound assisted regioselective sulfonation of aromatic compounds with sulfuric acid

A simple and convenient methodology for selective sulfonation of aromatic compounds using sulfuric acid under sonication is described. The present methodology shows a considerable enhancement in the reaction rate along with improved selectivity compared with the reactions performed under silent conditions. The effect of various parameters such as agitation speed, sulfuric acid concentration, and temperature on reaction system have been investigated and are explained on the basis of ultrasonically generated cavitational effects.     

Bending of compressible initially curved blocks

The flexure problem of an initially curved cuboid is solved by obtaining a particular solution of the governing differential equation. The applied tractions required to sustain the deformation are calculated.     

Dielectric relaxation of Tripropylene glycol–water mixture using time domain reflectometry

The complex permittivity spectra of tripropylene glycol and water solutions have been obtained by time domain reflectometry (TDR) technique in the frequency range from 10 MHz to 30 GHz and the temperature range 20°C–05°C. The dielectric relaxation parameters such as static dielectric constant and relaxation time were obtained by using the non-linear least square fit method. The intermolecular hydrogen bonding of tripropylene glycol–water has been discussed using the Kirkwood correlation factor and thermodynamic parameters. The activation energy decreases with increase in water content in the mixture as expected in the Arrhenius behaviour. The dielectric constant for mixtures has been fitted to the Bruggeman mixture formula in the non-linear case.     

Comparison of new and existing algorithms for the analysis of 2D radioxenon beta gamma spectra

The aim of this paper is to compare radioxenon beta–gamma analysis algorithms using simulated spectra with experimentally measured background, where the ground truth of the signal is known. We believe that this is among the largest efforts to date in terms of the number of synthetic spectra generated and number of algorithms compared using identical spectra. We generate an estimate for the minimum detectable counts for each isotope using each algorithm. The paper also points out a conceptual model to put the various algorithms into a continuum. Our results show that existing algorithms can be improved and some newer algorithms can be better than the ones currently used.

     

A note on hypersurfaces in a sphere

We study the influence of a unit Killing vector field on the geometry of a hypersurface in the unit sphere. The combination of the Killing vector field on the hypersurface and the conformal vector field on the ambient sphere triggers the presence of four specific smooth functions on the hypersurface, we use these four functions to derive different sufficient conditions for a hypersurface to be the totally geodesic sphere and for a minimal hypersurface to be the totally geodesic sphere, Clifford minimal hypersurface respectively. In particular we classify compact minimal hypersurfaces with a unit Killing vector field in the unit sphere.     

Almost Contact Lagrangian Submanifolds of Nearly Kaehler 6-Sphere

For a Lagrangian submanifold M of S ⁶ with nearly Kaehler structure, we provide conditions for a canonically induced almost contact metric structure on M by a unit vector field, to be Sasakian. Assuming M contact metric, we show that it is Sasakian if and only if the second fundamental form annihilates the Reeb vector field ξ, furthermore, if the Sasakian submanifold M is parallel along ξ, then it is the totally geodesic 3-sphere. We conclude with a condition that reduces the normal canonical almost contact metric structure on M to Sasakian or cosymplectic structure.     

From beads-to-wires-to-fibers of tungsten oxide: electrochromic response

Suitable host lattice and morphology for easy intercalation and deintercalation process are crucial requirements for electrochromic device. In this investigation, the evolution of structural and morphological changes and their effect on electrochromic (EC) properties of spray-deposited WO₃ thin films are studied. Films of different morphologies were deposited from an ammonium tungstate precursor solution using a novel pulsed spray pyrolysis technique (PSPT) on tin-doped indium oxide (ITO) coated glass substrates by varying quantity of spraying solution. Interesting morphological transition from beads-to-wires-to-fibers as a function of quantity of sprayed solution has been demonstrated. The porosity, crystallinity and “open” structures in the films consisting of beads, wires, and fiber-like morphology enabled us to correlate these aspects to their EC performance. WO₃ films comprising wire-like morphology (20 cc spraying quantity) exhibited better EC properties both in terms of coloration efficiency (42.7 cm²/C) and electrochemical stability (10³ colored/bleached cycles) owing to their adequate open structure, porosity, and amorphicity, compared with the films having bead/fiber-like morphology.