Multiobjective fractional programming problems involving (p,r)?ρ?(η,θ)-invex function

In this paper we move forward in the study of multiobjective fractional programming problem and established sufficient optimality conditions under the assumption of (p,r)????(??,??)-invexity. Weak, strong and strict converse duality theorems are also derived for three type of dual models related to multiobjective fractional programming problem involving aforesaid invex function.     

Modelling of guided-wave Bragg gratings and grating sensors using the collocation method

We have used the collocation method to model the characteristics of guided-wave Bragg gratings. The collocation method being a total field method, takes into account all modes, guided as well as radiation. We have first studied the effect of the grating structural parameters such as the grating profile and the duty cycle of periodic variation and have shown that these can have significant effect on the Bragg wavelength and the reflection spectrum. We have then obtained the response characteristics of gratings for their use in strain, temperature and pressure sensing. Our results compare very well with available experimental results. Comparisons with the coupled mode theory have also been included.     

Urea-thiazole/benzothiazole hybrids with a triazole linker: synthesis,antimicrobial potential,pharmacokinetic profile and in silico mechanistic studies

Molecular Diversity - Some urea-thiazole/benzothiazole hybrids with a triazole linker were synthesized via Cu(I)-catalysed click reaction. After successfully analysed by various spectral techniques...     

Ultrasonic and viscometric studies of molecular interactions in binary mixtures of formamide with ethanol, 1-propanol, 1,2-ethanediol and 1,2-propanediol at different temperatures

The ultrasonic speeds, u and viscosities, η of binary mixtures of formamide (FA) with ethanol, 1-propanol, 1,2-ethanediol, and 1,2-propanediol, including those of pure liquids, over the entire composition range were measured at 293.15, 298.15, 303.15, 308.15, 313.15, and 318.15 K. From the experimental values of u and η, the deviations in isentropic compressibility, Δk_s, in ultrasonic speed, Δu, and in viscosity, Δη were calculated. The variation of these parameters with composition and temperature of the mixtures are discussed in terms of molecular interaction in these mixtures. The observed trends in Δk_s values indicate the presence of specific interactions between FA and alkanol molecules. The Δk_s values follow the order: ethanol < 1-propanol < 1,2-propanediol < 1,2-ethanediol. It is observed that the Δk_s values depend upon the number of hydroxyl groups and alkyl chain length in these alkanol molecules. Furthermore, the free energies, ΔG, enthalpies, ΔH and entropies, ΔS of activation of viscous flow have also been obtained by using Eyring viscosity equation and their dependence on composition of the mixtures have been discussed.     

Line broadening studies in low energy plasma focus

Optical emission spectroscopic studies were carried out to characterise the plasma leading to the estimation of two plasma parameters, electron density and temperature. These experiments were conducted on a 2 kJ plasma device which is equipped with squirrel cage electrode configuration enclosed in a glass vacuum chamber filled with hydrogen at a pressure of 5 mbar. Spectral emissions obtained from each flash were photographed in the region of 4000–6000 Å using one metre Czerny-Turner spectrograph cum monochromator. Detailed examination of the observed features showed that theH _β andH _λ lines of hydrogen showed significant broadening of the order of 35 Å FWHM which is due to Stark effect expected in high density plasmas. Further several atomic lines of Cu and Zn from the electrode material (brass) showed broadening which was due to quadratic Stark effect. A comparative study of the broadening of lines obtained in DC arc, hollow cathode and plasma focus was made. Electron density from Stark broadened hydrogen lines and quadratic Stark Coefficient C₄ for the CuI and ZnI lines were evaluated. The excitation temperature was determined from the line intensity ratio method using CuI lines.     

Higher-order duality for nondifferentiable minimax programming problem with generalized convexity

In this paper, we are concerned with a class of nondifferentiable minimax programming problems and its two types of higher-order dual models. We establish weak, strong and strict converse duality theorems in the framework of generalized convexity in order to relate the optimal solutions of primal and dual problems. Our study improves and extends some of the known results in the literature.     

Coupling of two parallel multimode parabolic index waveguides: An exact analysis in the weakly guiding approximation

A model analysis of a guiding structure consisting of two parallel multimode parabolic-index waveguides in the weakly guiding approximation has been presented. Such structures are expected to play an important role as directional couplers in data bus systems, etc. The modes thus obtained have been used to study the power exchange between the two waveguides and a simple analytical expression has been obtained for the coupling length in a case of practical importance.     

Chromatographic and electrophoretic migration parameters in capillary electrochromatography

Chromatographic retention factor, k', as defined in high-performance liquid chromatography (HPLC) in terms of the migration times of the separand and the inert tracer, has limited applicability to capillary electrochromatography (CEC) when both chromatographic and electrophoretic processes determine the magnitude of the overall migration rates of the separands. This situation is unlike that in HPLC, where k' serves as a useful peak locator for the various sample components, as well as, provides thermodynamic insights into the interactions between the components and the stationary phase. Most publications have borrowed the definition of k' from HPLC and applied it on CEC. However, due to the dual separation mechanisms that are in action in CEC, the system is significantly complicated in comparison to that of HPLC. This paper discusses the impossibility of defining with a k' which would have all the attributes that it has in regular chromatography. The interplay of the two separation mechanisms in determining the overall migration process in CEC is discussed and the various definitions of the electrochromatographic retention factor are presented.     

Molecular Interactions in Formamide + Isomeric Butanols: An Ultrasonic and Volumetric Study

Densities, , ultrasonic speeds, u and viscosities, of the binary mixtures of formamide (FA) with 1-butanol, 2-methyl-1-propanol, and 2-methyl-2-propanol, including those of pure liquids, were measured over the whole composition range at 35°C. Using the experimental values of , u and , the deviations in isentropic compressibility, _s , excess volume, V ^E, viscosity, , and excess Gibbs energy of activation of viscous flow, G* ^E , were calculated from the linear dependence of these parameters on composition of mixtures. The apparent molar isentropic compressibility, K _,2 and apparent molar volume, V ^,2 of alcohols in FA were also calculated. The variations of these parameters with composition are discussed from the point of view of intermolecular interactions in these mixtures. The V ^E data have also been analyzed using Prigogine–Flory–Patterson theory. An analysis of each of the three contributions, viz., interactional, free volume, and P* effect to V ^E shows that P*, the internal pressure parameter of the theory, plays a dominant role in deciding the sign and magnitude of V ^E.