Multi-analyte HPLC–DAD Method for Concurrent Analysis of Six Antimicrobials and Three Proton Pump Inhibitors Frequently used in Management of Helicobacter pylori Infection: Application to Simulated Intestinal Fluid Samples

Chromatographia - The present work deals with the optimization, validation and application of a versatile HPLC–DAD method for concurrent estimation of nine antimicrobials and proton pump...     

Two- and three-dimensional comparative study of heat transfer and pressure drop characteristics of nanofluids flow through a ventilated cubic cavity (part I: Newtonian nanofluids)

Journal of Thermal Analysis and Calorimetry - Through this paper, three-dimensional fluid flow and heat transfer of Al2O3 nanofluid within ventilated enclosures was taken into consideration....     

Application of differential electrolytic potentiometry for detection in flow injection analysis

The applicability of differential electrolytic potentiometry as a detection system in flow injection analysis is investigated. A computer-controlled injector which delivers precise volumes of sample solutions in a reproducible manner was developed. Conditions such as current density employed, the concentrations of the solutions used and the flow rate were optimized. Chloride in water was determined by means of this system. The relation between chloride concentration and the measured signal was found to be Nernstian for solutions of concentrations above 6 μg ml⁻¹ chloride. For solutions below this concentration, the relation is linear.     

Equivalences of comodule categories for coalgebras over rings

In this article we defined and studied quasi-finite comodules, the cohom functors for coalgebras over rings. Linear functors between categories of comodules are also investigated and it is proved that good enough linear functors are nothing but a cotensor functor. Our main result of this work characterizes equivalences between comodule categories generalizing the Morita-Takeuchi theory to coalgebras over rings. Morita-Takeuchi contexts in our setting is defined and investigated, a correspondence between strict Morita-Takeuchi contexts and equivalences of comodule categories over the involved coalgebras is obtained. Finally, we proved that for coalgebras over QF-rings Takeuchi's representation of the cohom functor is also valid.     

Synthesis,dynamic light scattering,and luminescence properties of copolymers containing iridium(III) bisterpyridine in the side chain

Supramolecular block‐random copolymers containing [Ir(terpy)₂]³⁺ in the side chain were synthesized via postfunctionalization of a P(S‐b‐AC_terpy) block copolymer. Absorbance and emission spectra compared to a model compound show that the polymer backbone has a minor effect on the polymer absorbance but produces a larger shift for the phosphorescence signals to higher wavelength. Dynamic light scattering of the metal complex containing copolymer studied in various solvents showed monomodal aggregation with decreasing aggregate size as the solvent dielectric constant increased. The copolymer precursor P(S‐b‐AC_terpy) shows multimodal aggregation in different solvents with the major population consisting of single chains. This difference in behavior between the two polymers is attributed to the electrolytic nature of the complex and the amphiphilicity induced by the charged metal complex. Supramolecular copolymers like these will continue to have interesting self‐organizational properties and may find applications in multicomponent systems for photoinduced charge separation processes. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1109–1121, 2007     

Eigenvalue Spectrum of a Dirac Particle in Static and Spherical Complex Potential

It has been observed that a quantum theory need not be Hermitian to have a real spectrum. We study the non-Hermitian relativistic quantum theories for many complex potentials, and obtain the real relativistic energy eigenvalues and corresponding eigenfunctions of a Dirac-charged particle in complex statically and spherically symmetric potentials. Complex Dirac–Eckart, complex Dirac–Rosen–Morse II, complex Dirac–Scarf and complex Dirac–Poschl–Teller potential are investigated.     

Heat transfer and flow induced by both natural convection and vibrations inside an open-end vertical channel

The effects of oscillatory motions that may present at a wall during vibrating conditions are studied on flow induced by natural convection and heat transfer inside an open-end vertical channel. The governing equations are non-dimensionalized and reduced to simpler forms. Analytical solutions are obtained for several limiting cases. The reduced governing equations are solved for various values of the controlling parameters. It is found that mean values of average Nusselt numbers are mainly affected by the Grashof number and the amplitude of the horizontal vibrations. Further, amplitudes of Nusselt numbers at the vibrated wall are decreased as the Grashof number increases for horizontal vibrations while they are increased as amplitudes of vibrations increase. It is also found that the squeezing/vibrational Reynolds number, Grashof number and amplitudes of vibrations have a great influence on the trends of stream lines and isotherms especially at low Grashof numbers. Finally, correlations that summarize the effects of the different controlling parameters are determined on the Nusselt numbers and their amplitudes at relatively low frequency of vibrations.     

Spectrophotometric determination of halogenated 8-hydroxyquinoline derivatives

A spectrophotometric method is proposed for the determination of 8-hydroxyquinoline and three of its iodinated derivatives: 5-chloro-7-iodo-8-hydroxyquinoline (clioquinol), 5,7-di-iodo-8-hydroxy-quinoline (iodoquinol) and 8-hydroxy-7-iodo-quinolone-5-sulphonic acid (chinoform). The suggested method depends on the reaction with 4-aminoantipyrine in the presence of an alkaline oxidizing agent. A red antipyrine dye with an absorption peak at 500 nm is produced in all cases. The reacting ratio has been determined and a reaction mechanism is presented. The proposed method can be applied to the analysis of pharmaceutical preparations containing the compounds studied, and the results obtained compare favourably with those obtained with the standard methods.     

Flow injection determination of ergonovine maleate with amperometric detection at the Kel-F-graphite composite electrode

The Kel-F-graphite electrode was used for the electrochemical detection of ergonovine maleate in a flowing stream. It was found useful in the analyte concentration range 0.5-20 mug ml , with a detection limit of 50 ng ml (1.1 x 10(-7)M). A procedure was developed for assay of ergonovine maleate in tablets, and the results obtained agreed with those given by the official U.S. Pharmacopeia method.     

Kinetic Spectrophotometric Determination of Ritodrine Hydrochloride in Dosage Forms

A simple and sensitive kinetic method was developed for the determination of ritodrine hydrochloride in pharmaceutical preparations. The method is based upon a kinetic investigation of the oxidation reaction of the drug with alkaline potassium permenganate at room temperature for a fixed 12.5 min; the absorbance of the colored permenganate ion was measured at 609 nm. The absorbance concentration plots were rectilinear over the range of 1.6–11.2 μg mL^?1 (r = 0.9992) with a minimum detectability of 0.096 μgmL^?1 (2.88 × 10^?7 M). The different experimental parameters affecting the development and stability of color were carefully studied and optimized. The determination of ritodrine hydrochloride by the fixed concentration and rate constant methods is also feasible with the calibration equations obtained, but the fixed time method has been found to be more applicable. The proposed method was applied successfully to the determination of ritodrine hydrochloride in tablets and ampoules with average recoveries of 100.37 ± 0.93% and 100.42 ± 0.87%, respectively. The results obtained were in good agreement with those obtained using a reference method for comparison. A proposal of the reaction pathway is also presented.