Existence of positive stationary solutions for a diffusive variable-territory prey–predator model

This paper concerns the existence of positive stationary solutions for a diffusive variable-territory prey–predator model, and completely settles an open problem of Wang and Pang (2009). The main result closes a gap in an earlier result (2011) by the authors.     

A Short,Efficient, Multigram Synthetic Route to 2,3-Dimethylfuran and Some of its 2-Substituted Derivatives

A laboratory, multigram (1000 g in an hour) preparation procedure for 2,3-dimethylfuran, based on the frequently repeated thermal cyclization of (Z) 3-methyl-2-penten-4-yn-1-ol, as well as its subsequent formylation, acetylation and oxidation is described.     

A neutral multi-coated sphere under non-uniform electric field in conductivity

We consider a neutral spherical inclusion for three-dimensional conductivity. Such an inclusion when inserted into a matrix does not disturb an arbitrary non-uniform electric field outside the inclusion. Our design is realized by means of multi-coating which cancels the lower order, generalized polarization tensors. Analytical results for a doubly coated sphere and detailed numerical results for a sphere with three or more coatings are presented to demonstrate the theory.     

Periodicity in the formulae of carbonyls and the electronic basis of the Periodic Table

The basis of the Periodic Table is discussed. Electronic configuration recurs in only 21 out of the 32 groups. A better basis is derived by considering the highest classical valency (v) exhibited by an element and a new measure, the highest valency in carbonyl compounds (v*). This leads to a table based on the number of outer electrons possessed by an atom (N) and the number of electrons required for it to achieve an inert (noble) gas configuration (N*). Periodicity of these is nearly complete. The new basis helps to settle the question of the best form of table and related issues.     

Measurement of the Rates of Diffusion of Halomethanes into Polymer Films Using ATR-FTIR Spectroscopy

Polymer-modified attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy and FEWS (fibre-optic evanescent wave) spectroscopy have been very successful to date for sensitive detection of organic pollutants in water utilising the mid-infrared (MIR) region of the electromagnetic spectrum (4000-400 cm^?1). This sensing approach involves the use of different polymer films for preconcentration with optimisation of the sensor related to the rate of diffusion of solvent molecules into these polymer films. Compounds such as chloroform, bromoform, bromodichloromethane and dibromochloromethane which are collectively referred to as trihalomethanes (THMs) were analysed in this work. A gaseous phase experimental design was used and from experimental data the rate of diffusion of each of the halomethanes was quantified based on a Fickian type diffusion model. Individual diffusion coefficient values were found to be in the range 3.38 E-10 ± 0.01 E-10 to 4.72 E-08 ± 0.42 E-08 cm² s^?1. Multicomponent effects were observed for mixtures of compounds diffusing into polyisobutylene and ethylene-propylene copolymer.     

Ferromagnetic liquid crystals for magnetic field visualisation

In this paper, we demonstrate how to apply recently discovered ferromagnetic nematic liquid crystal for visualisation of magnetic fields. The material exhibits strong optical response to both external electric and magnetic fields, which gives us an opportunity to use it for the detection of an area of magnetic vector field in a way that both, the magnitude and the direction of a given field can be simultaneously measured. We discuss the physical model that describes the behaviour of ferromagnetic liquid crystal placed in a liquid crystal cell and demonstrate the method of extracting the information about an arbitrary magnetic field from the combination of magneto-optic and electro-optic response of the sample placed in that field. We have applied the principle to a special case, where magnetic field was visualised on a 2D area near a cylindrical permanent magnet.     

Determination of Iprodione,Vinclozolin, and Procymidone as the Heptafluorobutyramides of 3,5-Dichloroaniline

Abstract

A method was developed for the determination of three fungicides in foods based on alkaline degradation to 3,5-dichloroaniline, isolation of the latter by steam distillation and measurement of the heptafluorobutyrate by gas chromatography. Recoveries averaged 91% from several commodities spiked at from 10–80ppb. The minimum detectable limit of 2.6ppb was attainable in grape, with similar limits found in strawberry, tomato and beans. The method was capable of determining degradation products formed as a result of cooking.