French-Ukrainian Journal of Chemistry
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Peculiarities Of Triazoloazepinium Bromides Effect On Steel Microbial Corrosion
Get PDFTriazoloazepinium bromides act as biocides against sulfate-reducing bacteria and can produce an effect on mild steel microbial corrosion. It has been established that under the competing adsorption, the compounds with the properties of corrosion inhibitors can form a film, which protects the steel surface, before it is settled by corrosively active microorganisms.The protective film ensures the inhibition efficiency of up to 98.7%. With triazoloazepinium bromides of the 2nd group, corrosively active microorganisms colonize the steel surface before the inhibitor creates the protective layer. In this case, the biocorrosion accelerates by up to 6.25 times. Different effect of triazoloazepinium bromides on steel biocorrosion rate is explained by the molecular structure
Determination of Fenspiride Hydrochloride Residues on Pharmaceutical Manufacturing Equipment Surfaces by HPLC Method
Get PDFThe cleaning procedure must be validated, so special attention must be devoted to the methods used for determination of trace amounts of drugs. A rapid, sensitive, and specific reverse phase high-performance liquid chromatographic (HPLC) method was developed for the quantitative determination of fenspiride hydrochloride residues on pharmaceutical manufacturing equipment surfaces. The calibration curve was linear over a concentration range from 1.0 to 100.0 μg/ml with a correlation coefficient of 0.99994. The detection limit and quantitation limit were 0.41 μg/ml and 1.25 μg/ml, respectively. The developed method was validated with respect to specificity, linearity, limit of detection, accuracy and precision
Electrostatic and solvation-thermodynamic approaches as a tool to study formation of electrical double layer of ionogenic surfactants micelles
Get PDFThe solvation-thermodynamic approach to study formation of electrical double layer of ionogenic surfactants micelles is proposed. The equations to estimate the Galvany potential of micelles formed by ionogenic surfactants are proposed. The apparent dissociation constant thermodynamic interpretation of the electrolyte in micellar solutions is given
The photoelectrochemical cell with hydrogen accumulation at the conditions of natural insolation
Get PDFThe film photoanodes based on CdSe and NT-TiO2/CdSe have been formed by the electrochemical and painting methods. It is shown that the introduction of graphene oxide into the structure of the semiconductor CdSe film promotes absorption of light and leads to improvement in their characteristics by 25-30 %. The compatibility of the cathode based on composite of hydrogen-sorbing intermetallic alloys LaNi4.5Mn0.5 + LaNi3.5Al0.7Mn0.8 with current-conductive additives in pair with the CdSe photoanode is shown. It was found that 95 – 98 % of the total current generated under the influence of sunlight at the anodes was used on the formation and accumulation of hydrogen by cathodes
Study of Chemical Dissolution of Cu98Be Alloy in Solutions Based on FeCl3
Get PDFProcess of chemical dissolution of beryllium bronze in various electrolytes was studied. Taking into account complex formation processes during chemical etching in solutions based on FeCl3 the ionization rate and selectivity of dissolution of Cu98Be alloy components was determined. It was shown that uniform and high rated chemical dissolution of beryllium bronze is possible in acidic medium in presence of Fe3+ ion-oxidizer and chlorine ions. An optimal etching solution composition was proposed. The surface morphology of the beryllium bronze electrode after etching in the investigated solutions was studied. An absence of passivation on the alloy Cu98Be surface was shown and salt and oxide nature of the grains of compounds formed on the electrode surface after chemical etching was proved
Joint Impedance Spectroscopy and Fractography Data Analysis of Ceria Doped Scandia Stabilized Zirconia Solid Electrolyte modified by powder types and sintering temperature
Get PDFParameters of the non-Debye relaxation in the 10Sc1CeSZ solid electrolyte made of various types of ZrO2 powder stabilized with 10-mol.% Sc2O3 and 1-mol.% CeO2 were studied. The influence of powder properties and their sintering temperatures on the impedance spectra is analyzed. In regard to electrical response, the polycrystalline ceramic electrolytes may be considered as a single-phase or a two-phase material consisting of a grain bulk and a boundary. In many cases, the boundary resistance is independent practically on dopants and their distribution across the powders and sintering temperatures. The powder compositions suitable for an electrolyte and electrodes are specified
Peculiarities of the reactions of a,b-unsaturated g-bromoketones with hydrazine derivatives
Get PDFThe reaction result of a,b-unsaturated g-bromoketones with hydrazines depends on the structure of the reagents. Reaction with hydrazine hydrate leads to the mixture of 3,5- di(R)pyridazine, 3,6-di(R)pyridazine and 2,4-di(R)-1H-pyrrol-1-amine derivatives. The formation of three types of products is due to the structure of the unsaturated aliphatic ketone. Two competing reaction schemes of ketones with hydrazines are considered, which include condensation or Michael-type addition in the first stage. The main products of the reactions of halogen-substituted derivatives of g-bromodipnone with arylhydrazines are 1,3,5-triaryl-1,6-dihydropyridazines, which easily form aromatic salts under reaction conditions (when heated in EtOH)
Zirconium Oxide Stabilized By Scandium (III) And Cerium (IV) Complex Oxides As The Basis For Preparation Of Thick Films And Multilayers Structures For Low Temperature (600 °C) Fuel Cell
Get PDFWeakly agglomerated zirconium dioxide nanopowders stabilized by complex oxides of scandium (III) and cerium (IV) were synthesized by precipitation from aqueous solutions. Using weakly agglomerated nanopowders, thick films were prepared by tape casting on a-Al2O3 substrates. These thick films have high oxygen conductivity; and their electron conductivity is lower than oxygen conductivity by 4 orders of magnitude. A multilayer system consisting of films of polycrystalline porous anode and solid electrolyte was prepared. The diffusion of cations in the anode boundary layer and change in the chemical composition of the electrolyte film are not observed at optimum synthesis conditions
Improvement of the Membrane - less Electrolysis Technology for Hydrogen and Oxygen Generation
Get PDFTo provide the most efficient electrolysis process of hydrogen and oxygen generation and the electrode twain design there were studied the following:- The process of high pressure hydrogen and oxygen cyclic generation in the membrane less electrolysis systems.- The permissible ranges of voltage variation on the electrodes were determined depending on the electrochemical reactions taking place on the active electrode.- There was studied the process of hydrolysis and oxidation of the active electrode hypoferrite at the corresponding half-cycles of hydrogen and oxygen release.- There was studied the effect of variation of the distance between the active and passive electrodes onto the electrolysis process efficiency
Photoelectrochemical properties of films based on TiO2 nanotubes modified with BiVO4 and V2O5
Get PDFBy methods of anodizing and ion layering were obtained films TiO2/V2O5 and TiO2 / BiVO4. With help of spectral studies of photoelectrochemical and optical properties, the band gap and quantum yield of photoelectrochemical current were determined depends on the ratio of films thickness and the parameters of their synthesis. It is shown, that at synthesized structures UV component quantum yield photoelectrode decreases and contribution of visible light increases