Intersection graphs of ideals of rings

In this paper, we consider the intersection graph G(R) of nontrivial left ideals of a ring R. We characterize the rings R for which the graph G(R) is connected and obtain several necessary and sufficient conditions on a ring R such that G(R) is complete. For a commutative ring R with identity, we show that G(R) is complete if and only if G(R[x]) is also so. In particular, we determine the values of n for which is connected, complete, bipartite, planar or has a cycle. Next, we characterize finite graphs which arise as the intersection graphs of and determine the set of all non-isomorphic graphs of for a given number of vertices. We also determine the values of n for which the graph of is Eulerian and Hamiltonian.     

Aggregation-Induced Emission-Based Sensing Platform for Selective Detection of Zn2+: Experimental and Theoretical Investigations

Fluorescent chemosensors with aggregation induced emission enhancement (AIEE) emerge as promising tools in the field of sensing materials. Herein, we report the design, synthesis and applicability of a Schiff base chemosensor 1-(benzo[1,3]dioxol-4-ylmethylene-hydrazonomethyl)-naphthalen-2-ol ( Hbdhn ) of AIE characteristics that exhibits highly effective and selective response towards Zn²⁺. The sensing effect of Hbdhn was evaluated by means of absorption/emission spectra and corresponding underlying photophysical mechanisms were proposed based on extensive quantum-chemical (TD)DFT calculations. The aggregated states in different DMSO/H₂O ratios and in a presence of Zn²⁺ were examined by fluorescence lifetime measurements, dynamic light scattering and scanning electron microscopy studies. The bioimaging abilities of Hbdhn were evaluated for Zn²⁺ in HepG2 cancer cells. The results demonstrate instant, stable in time and reproducible, colorimetric turn-on response with superb selectivity and sensitivity of Hbdhn towards Zn²⁺, based on chelation enhanced fluorescence mechanism. AIEE improves further Hbdhn properties, leading to strong, long-lived fluorescence, with appearance of rod-like particles, in 90 % of water in DMSO and only 10 % of water in DMSO in the presence of Zn²⁺. All these features combined with successful biomaging studies make Hbdhn one of the most promising candidate for practical applications among recently proposed related systems.     

Mechanical response in a composite free piezoelectric transducer with a time-decaying polarization gradient

This article aims at finding the mechanical response of a composite free piezoelectric transducer with a time decaying polarization gradient when it is subjected to an electric voltage input.The author is grateful to Dr. D. K. Sinha for his immense help and active guidance.     

Carbon monoxide oxidation on cobaltites of the lanthanides: Effect of A-site substitution

Catalytic oxidation of CO has been studied on Nd_1–xBa_xCoO₃ and LnCoO₃ (Ln=La, Sm, Nd, Dy). Catalytic activity was compared with changing x, oxygen defects and structural changes. It has been found that compounds with cubic structure show maximum activity, which decreases with deviation from cubic structure. This has been explained as due to better delocalization of the d-electrons of cobalt in the cubic compounds.

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CO Nd_1–xBa_xCoO₃ LnCoO₃ (Ln=La, Sm, Nd, Dy). , . , , . d- .

     

Reaction-based sensing of fluoride ions using desilylation method for triggering excited-state intramolecular proton transfer

Naphthalene based benzothiazole (NBT) has been investigated as new colorimetric and ratiometric fluorescent chemosensor for fluoride. The selectivity of NBT has been explored based on combination of desilylation reaction and modulation of the excited-state intramolecular proton transfer (ESIPT) from the desilylation product to F^?. The method exhibited a high selectivity and a great sensitivity toward fluoride anions through ‘turn-on’ chromogenic activity and sensitivity. The structure of HNBT has been established by single-crystal XRD. Density functional theory and TDDFT calculations were performed in order to demonstrate the electronic properties of HNBT, NBT and their anion. Upon treatment with fluoride in aqueous CH₃CN solution, the TBS protective group of probe NBT was removed readily and ESIPT of the probe was switched on, which resulted in a decrease of the emission band at 415 nm and an increase in a new fluorescence peak around 586 nm. An easy-to-prepare test paper, obtained by dipping the paper into the solution of NBT, was able to detect fluoride ions in practical samples. The detection limit of the probe in the determination of fluoride ions was 10.18 μM.     

A Keggin heteropoly acid as an efficient catalyst for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles

The Keggin heteropoly acid, silicotungstic acid, H₄SiW₁₂O₄₀, has been demonstrated to be highly efficient for an expeditious, one-pot synthesis of 1-methyl-2-(hetero)arylbenzimidazoles from N-methyl-1,2-phenylenediamine and (hetero)aryl aldehydes in ethyl acetate at room temperature. The catalyst works equally well for N-phenyl-1,2-phenylenediamine.     

Mass spectra of higher states of quarkonia and decays for scalar-vector confining interaction

Recently, we have studied a flavour-independent potential for quark-antiquark systems of equal and unequal masses in which the confining interaction is scalar-vector admixture with dominant scalar interaction and the spin-dependent part of the potential has been obtained from the non-relativistic reduction of the Bethe-Salpeter kernel. This potential was found to explain the heavy-quark data well. In the present work we have obtained further affirmative tests of the model by calculating the mass spectra of higher levels as well as the confining contribution of the spin-orbit forces forL1 states of quarkonia. We have considered the annihilation processes and radiative transitions too. The former include leptonic decay, two-photon decay, two-gluon annihilation, three-photon decay and three-gluon annihilations.