Effect of Specific Solute-Solvent Interaction and Electron Donor-Acceptor Substituents of Novel Pyrazolo Naphthyridines on Fluorescence

Heterocyclic orthoaminoaldehyde such as 4-amino-3-(4-phenyl)-1-phenyl-1H-Pyrazolo[3,4-b]pyridine-5-carbaldehyde was synthesized by multistep reactions involving reduction of azido derivative 2 with LAH to yield aminoalcohol 3 and oxidation of it with MnO(2) to aminoaldehyde 4.The pyridine ring annulated on to 4 by Friedl?nder condensation using acetophenones in presence of base to obtained pyrazolo[3,4-h][1,6]naphthyridine 5 in excellent yield. Study of photophysical properties of 5 revealed that the absorption and emission of them depends up on the substituents present on benzene ring in newly annulated pyridine ring.     

The Steiner tree problem II: Properties and classes of facets

This is the second part of two papers addressing the study of the facial structure of the Steiner tree polyhedron. In this paper we identify several classes of facet defining inequalities and relate them to special classes of graphs on which the Steiner tree problem is known to be NP-hard.Corresponding author.The author appreciates partial support from National Science Foundation Grants Nos. DSM-8606188 and ECS 8800281.     

Measurement problem in quantum mechanics: Characteristics of an apparatus

The problem of measurement in Quantum Mechanics will be briefly reviewed. Since the measurement process involves a macroscopic apparatus, the attention is focussed on the dynamics of a pointer-like variable of the apparatus when it interacts with a quantum system. It is argued that since the measurement process requires an apparent collapse of the wave function in a certain basis, and collapse is an irreversible process, understanding of irreversibility in a quantum macroscopic system is crucial. The chief characteristics of an apparatus that are important in understanding measurement process are (a) its closely spaced energy levels and (b) its interaction with environment. The coupling with the environment drives the density matrix of the apparatus to diagonal form, but to have persistent correlations between system and apparatus states, it seems necessary to have a pointer variable that has a classical limit     

Dual row modules and polyhedra of blocking group problems

Corresponding to every group problem is a row module. Duality for group problems is developed using the duality or orthogonality of the corresponding row modules. The row module corresponding to a group problem is shown to include Gomory's fractional cuts for the group polyhedron and all the vertices of the polyhedron of the blocking group problem. The polyhedra corresponding to a pair of blocking group problems are shown to have a blocking nature i.e. the vertices of one include some of the facets of the other and mutatis mutandis. The entire development is constructive. The notions of contraction, deletion, expansion and extension are defined constructively and related to homomorphic liftings and suproblems in a dual setting. Roughly speaking a homomorphic lifting is dual to forming a subproblem. A proof of the Gastou-Johnson generalization of Gomory's homomorphic lifting theorem is given, and dual constructions are discussed. A generalization of Gomory's subadditive characterization to subproblems is given. In the binary case, it is closely related to the work of Seymour on cones arising from binary matroids.     

Electro-mechanical instability modelling in elastomeric actuators: A second law of thermodynamics-based approach

ABSTRACT

In the present paper, we report an alternative method to model the electro-mechanical instability (EMI) phenomenon of the dielectric elastomeric (DE) actuators. The proposed method is based on a classical continuum mechanics approach followed by the second law of thermodynamics. We first formulate an electro-elastic deformation of a continua through an amended energy function followed by the theory of electro-elasticity. The amended energy function accounts the electrostriction phenomenon for a class of an incompressible isotropic electro-elastic material. In addition, the proposed energy function also overcomes the hurdle of the physical interpretation of the Maxwell stress tensor in large deformation. We then consider that the DE actuators are subjected to a pre-stretching effect through a simple loading with an applied electrical voltage across the thickness. Further, we develop the analytical EMI models for the DE actuators through a new amended energy function. Finally, the obtained EMI models through the proposed method are compared with an existing energy-based method, and also validated with the experimental data existing in the literature. The comparison and validation indicate that the proposed classical method is more realistic as compared to the existing one.     

Oxidative dehydrogenation of propane over chromium and nickel oxide modified V2O5/ZrO2 catalysts

The effect of addition of chromium and nickel oxides on the physicochemical properties and performance of V₂O₅/ZrO₂ catalysts was studied for the oxidative dehydrogenation of propane. Addition of chromium oxide increased, whereas addition of nickel oxide lowered the activity. Selectivity for propene was lower for the doped catalysts. The selectivity was lowered by higher total acidity as well as the higher concentration of stronger acid sites in doped catalysts.     

Sustainable existence of solid mercury (Hg) nanoparticles at room temperature and their applications

Although liquid mercury (Hg) has been known since antiquity, the formation of stable solid nano forms of Hg at room temperature has not been reported so far. Here, for the first time, we report a simple sonochemical route to obtain solid mercury nanoparticles, stabilized by reduced graphene oxide at ambient conditions. The as-formed solid Hg nanoparticles were found to exhibit remarkable rhombohedral morphology and crystallinity at room temperature. Extensive characterization using various physicochemical techniques revealed the unique properties of the solid nanoparticles of Hg compared to its bulk liquid metal phase. Furthermore, the solid nature of the Hg nanoparticles was studied electrochemically, revealing distinctive properties. We believe that solid Hg nanoparticles have the potential for important applications in the fields of electroanalytical chemistry and electrocatalysis.

Formation of the stable solid mercury nanoparticles by acoustic cavitation and their electrochemical activity compared to its bulk liquid metal.     

On the heat of formation of [C6H4]+˙

The appearance energy of the [C₆H₄]^+˙ ion from benzonitrile has been measured, using an electron monochromator. The value observed at onset, 12.54±0.03 eV, leads to a heat of formation of 1304±3 kJ mol^?1. Possible reasons for widely divergent values reported previously are proposed.     

An attempt for modeling the atmospheric transport of tritium (<Superscript>3</Superscript>H) around the site of Narora atomic power station

Prediction of downwind tritium air concentrations in the environment around Narora Atomic Power Station was studied on the basis of Gaussian plume dispersion model. The tritium air concentrations by field measurement [measured tritium air concentrations in the areas adjacent to NAPS] were compared with the theoretically calculated values (predicted) to validate the model. This approach will be useful in evaluating environmental radiological impacts due to standard pressurised heavy water reactors.