Optimization of process of the honeycomb-like structure formation by the regime of reversing current (RC) in the second range

Journal of Solid State Electrochemistry - Formation of the honeycomb-like electrodes of copper by the regime of reversing current (RC) in the second range has been investigated. Morphological and...     

Mean-based iterative methods for finding multiple roots in nonlinear chemistry problems

Journal of Mathematical Chemistry - This research deals with the problem of finding multiple roots of nonlinear equations. Not long ago, Chicharro et al. have derived an efficient class of optimal...     

Basic reverse order law and its equivalencies

In this paper we present new results related to various equivalencies of the reverse order law ${(AB)^{\dag} = B^{\dag} A^{\dag}}$ for the Moore–Penrose inverse for operators on Hilbert spaces. Some finite dimensional results given by Tian (Int J Math Educ Sci Technol 37(3):331–339, 2007) are extended to infinite dimensional settings; also some new more general relations are proved.     

Morphology and internal structure of copper deposits electrodeposited by the pulsating current regime in the hydrogen co-deposition range

The effect of the regime of pulsating current (PC) on copper electrodeposition in the hydrogen co-deposition range was examined by the techniques of scanning electron and optical microscopes. The quantities of evolved hydrogen and morphologies of electrodeposited copper strongly depended on the applied parameters of square waves PC, such as the current density amplitude (or the amplitude of the cathodic current density), deposition pulse, and pause duration. The increase of the current density amplitude led to intensification of hydrogen evolution reaction, and the change of morphology of electrodeposited copper from dendrites and shallow holes to dish-like holes was observed. For the constant pause duration, the prolonging deposition pulses intensify hydrogen evolution reaction leading to the formation of the honeycomb-like structures. The set of modified equations considering the effect of hydrogen generated during metal electrodeposition processes by the pulsating current regime is also presented. The concept of “effective overpotential amplitude” was proposed to explain the change of copper surface morphology with the intensification of hydrogen evolution reaction.     

A Polarographic Study of Chlorogenic Acid and Its Interaction with Some Heavy Metal Ions

The behavior of chlorogenic acid (CGA) and its interaction with Hg(II), Pb(II), Cu(II), Cd(II) and Zn(II) has been studied using direct current (DC) and differential‐pulse polarography (DPP). Adsorptive and kinetic/catalytic anodic waves of CGA have been detected at ?0.02 and ?0.18 V vs. SCE, respectively; Hg(I)‐CGA surface disproportionation has been assumed. Reduction of Hg(II)‐ions, added in the buffered solution of CGA (pH 7.5), occurs rather than complexation, while the complex forming ability of CGA towards Pb(II) and Cu(II) has been observed. Stoichiometry 1 : 1 for Pb(II)‐CGA, and 1 : 1 and 1 : 2 for Cu(II)‐CGA has been established applying Job’s method of continuous variation on DPP data. UV‐vis spectrophotometric measurements additionally confirmed the existence and stoichiometry of Cu(II) complexes.     

Dehydration of rhyolite: activation energy,water speciation and morphological investigation

Journal of Thermal Analysis and Calorimetry - Rhyolite is an extrusive, igneous rock of aluminosilicate composition that upon rapid cooling forms obsidian. Obsidian is amorphous and contains...     

Sucrose ester-based biocompatible microemulsions as vehicles for aceclofenac as a model drug: formulation approach using D-optimal mixture design

We assessed the functionality of sucrose esters (sucrose laurate, myristate, palmitate, and stearate), relatively innocuous nonionic surfactants, in formulation of biocompatible microemulsions. The putative influence of surfactant structure on the extension of microemulsion region was explored through the construction of the pseudo-ternary phase diagrams for the isopropyl myristate/sucrose ester-isopropyl alcohol/water system, using the titration method and mixture experimental approach. Minor changes in surfactant tail length strongly affected the microemulsion area boundaries. D-optimal mixture design proved to be highly applicable in detecting the microemulsion regions. Examination of conductivity, rheology, and thermal behavior of the selected sucrose laurate and sucrose myristate-based microemulsions, upon dilution with water, indicated existence of percolation threshold and suggested the phase inversion from water-in-oil to oil-in-water via a bicontinuous structure. Atomic force micrographs confirmed the suggested type of microemulsions and were valuable in further exploring their inner structure. The solubilization capacity of aceclofenac as a model drug has decreased as the water volume fraction in microemulsion increased. High surfactant concentration and the measured solubility of aceclofenac in microemulsion components suggested that the interfacial film may mostly contribute to aceclofenac solubilization.