Determination of pesticide levels in natural water bodies requires complex chemical methods not always available in tropical countries where such control programmes are implemented. Apart from chemical methods, effectiveness of treatment can be estimated by mortality of target and non-target species. But the latter criteria do not permit a good appraisal of dispersion and residual activity of p...

The mathematical representation of chemical bonds in molecules is discussed. The molecule is viewed as a system of weakly interacting chemical bonds. The intrabond problems and the averaged electrostatic interbond interactions are handled at the . zeroth order, while the small interbond delocalization and dispersion effects are taken into account on the basis of the perturbation theory. A speci...

We present a theoretical analysis of stacking and destacking wave trains in excitable reaction-diffusion systems with anomalous velocity-wavelength dependence. For linearized dispersion relations, kinematic analysis yields an analytical function that rigorously describes front trajectories. The corresponding accelerations have exactly one extremum that slowly decays with increasing pulse number...

Graphene, a two-dimensional honeycomb lattice of sp 2 hybrid carbon, exhibit combination of unique characteristics such as high thermal and electrical conductivity, excellent mechanical strength and very high specific surface area, which promises their great potential for various applications including nanoelectronics, catalysis, sensors, energy storage devices, polymer composites, lubricants a...

The non-local van der Waals density functional (vdW-DF) of Dion et al (2004 Phys. Rev. Lett. 92 246401) is a very promising scheme for the efficient treatment of dispersion bonded systems. We show here that the accuracy of vdW-DF can be dramatically improved both for dispersion and hydrogen bonded complexes through the judicious selection of its underlying exchange functional. New and published...

By using SMA resins as a polymeric surfactant in an emulsion polymerisation process, alone or in combination with other surfactants, the stability of the dispersion under different kinds of stress (chemical, high shear or freeze/thaw) is significantly improved. The presence of SMA copolymer, adsorbed at the surface of the particles of an acrylic dispersion, enhances the stability of the latex b...

Despite intensive investigations over the past five decades, the microscopic origins of the fascinating dielectric properties of ABO3 relaxor ferroelectrics are currently poorly understood. Here, we show that the frequency dispersion that is the hallmark of relaxor behavior is quantitatively related to the crystal chemical characteristics of the solid solution. Density functional theory is used...

A facile method to synthesize a TiO2/PEDOT:PSS hybrid nanocomposite material in aqueous solution through direct current (DC) plasma processing at atmospheric pressure and room temperature has been demonstrated. The dispersion of the TiO2 nanoparticles is enhanced and TiO2/polymer hybrid nanoparticles with a distinct core shell structure have been obtained. Increased electrical conductivity was ...

Density fingering of exothermic autocatalytic fronts in vertically oriented porous media and Hele-Shaw cells is studied theoretically for chemical reactions where the solutal and thermal contribution to density changes have opposite signs. The competition between these two effects leads to thermal plumes for ascending fronts. The descending fronts behave strikingly differently as they can featu...