Bases of inorganic and organic chemistry

Stated fundamental theoretical principles of general, inorganic and organic chemistry and analyzed the reactivity of the most important classes of inorganic and organic substances. A multivariate tasks and exercises for classroom and independent work are proposed. For university students full-time and distance learning areas "Chemical Technology and Engineering" "Oil and gas engineering and technology" and others

Electrochemical processes and systems: application for tutors

The features of redox reactions and the principles of their balancing according to the medium composition are considered. The basic representations about electrochemical processes and systems are outlined. The reactions and principles of chemical sources of electric energy and electrolysis systems functioning are analyzed. A general idea is given about the chemical properties of metals, corrosion resistance in environments of various aggressiveness, and the protection principles are given. Multivariate tasks and exercises for students, and PhD student’s classroom and independent work are offered. For teachers, PhD students and students of universities of specialties "Chemical technologies and engineering", "Biotechnologies and bioengineering", "Oil and gas engineering and technologies".Розглянуто особливості окисно-відновних реакцій і принципи їх балансування залежно від складу середовища. Викладено фундаментальні уявлення про електрохімічні процеси і системи. Проаналізовано перебіг реакцій і принципи функціонування хімічних джерел електричної енергії та систем електролізу. Узагальнено уявлення щодо хімічних властивостей металів, корозійної стійкості у середовищах різної агресивності та наведено принципи організації захисту від руйнування. Запропоновано багатоваріантні завдання та вправи для аудиторної та самостійної роботи студентів і аспірантів. Розраховано на викладачів, аспірантів і студентів вищих навчальних закладів спеціальностей "Хімічні технології та інженерія”, "Біотехнології та біоінженерія", "Нафтогазова інженерія та технології"

Morphology and Properties of Coatings Obtained by Plasma-Electrolytic Oxidation of Titanium Alloys in Pyrophosphate Electrolytes

By means of scanning electron microscopy, atomic-force microscopy, X-ray fluorescence analysis, and X-ray spectral microanalysis it was shown that, under plasma-electrolytic oxidation (PEO) of titanium alloys in pyrophosphate electrolytes, well-adhered oxide coatings with microglobular morphology result. It was demonstrated that the chemical and phase composition of the coatings, as well as the surface topography and grain size, can be controlled by changing the concentration of a pyrophosphate electrolyte and a PEO current density. It was established that the resulting oxide layer is highly resistant to abrasive wear and enhances the titanium corrosion resistance in model media (Ringer’s solution) substantially, which suggests that the coatings are promising for use in biological applications

Study of the influence of oxidizing parameters on the composition and morphology of Al₂O₃·CoOₓ coatings on AL25 alloy

The influence of operating parameters of plasma-electrolytic oxidation in diphosphate cobalt-containing electrolyte on the process of formation of oxide coatings on alumosilicon alloy AL25 (GOST 1583) was studied. It was shown that inclusion of cobalt into the composition of surface oxide layers leads to a change of morphology and topography of the surface. Variation of current density and PEO time allows flexible control of the process of incorporation of the catalytic component into the matrix of oxide of basic metal. It was shown that at an increase in oxidation time, cobalt content in the surface oxide layer increases. The rational mode of plasma-electrolytic treatment of piston alloy in diphosphate electrolyte for obtaining oxide coatings, enriched with cobalt, was substantiated. It is advisable to perform formation of PEO-coatings on AL25 with developed globular-mosaic surface, maximum cobalt content, with minimizing impurities in the range of current densities of 3–5 A/dm² within 20–40 min. The obtained cobalt-containing oxide coatings can be used in the air and water purification systems, specifically, for intracylinder catalysis of gas emissions of internal combustion engines.Досліджено вплив робочих параметрів плазмово-електролітичного оксидування у дифосфатному кобальтвмісному електроліті на процес формування оксидних покривів на сплаві АЛ25. Встановлено, що склад та морфологія поверхні одержаних шарів Al₂O₃·CoOₓ залежать від густини струму обробки та часу оксидування. Варіювання параметрів ПЕО дозволяє гнучко керувати процесом інкорпорації каталітичного компоненту в матрицю оксиду основного металу. Обгрунтовано раціональний режим обробки поршневого силуміну для формування збагачених кобальтом оксидних покривів

Calculation of the Operation Parameters of the Catalytic Converters of the Harmful Gas Impurities

There are theoretically founded principles of catalytic converters designing of harmful gas emissions of various heat devices. Experimental investigations have shown that the smallest aerodynamic losses in the constructions of gas neutralizers are achieved at the using of profiled ceramic blades as working units - carriers of catalysts. To ensure intensive mixing of the flow inside the converter the input edges of the blades grids of the future stages should be located between the output edges of the blades of the grids of the preceding stages

Predicting the extremes of Indian summer monsoon rainfall with coupled ocean-atmosphere models

An analysis of the retrospective predictions by seven coupled ocean-atmosphere models from major forecasting centres of Europe and USA, aimed at assessing their ability in predicting the interannual variation of the Indian summer monsoon rainfall (ISMR), particularly the extremes (i.e. droughts and excess rainfall seasons) is presented in this article. On the whole, the skill in prediction of extremes is not bad since most of the models are able to predict the sign of the ISMR anomaly for a majority of the extremes. There is a remarkable coherence between the models in successes and failures of the predictions, with all the models generating loud false alarms for the normal monsoon season of 1997 and the excess monsoon season of 1983. It is well known that the El Niño and Southern Oscillation (ENSO) and the Equatorial Indian Ocean Oscillation (EQUINOO) play an important role in the interannual variation of ISMR and particularly the extremes. The prediction of the phases of these modes and their link with the monsoon has also been assessed. It is found that models are able to simulate ENSO-monsoon link realistically, whereas the EQUINOO-ISMR link is simulated realistically by only one model-the ECMWF model. Furthermore, it is found that in most models this link is opposite to the observed, with the predicted ISMR being negatively (instead of positively) correlated with the rainfall over the western equatorial Indian Ocean and positively (instead of negatively) correlated with the rainfall over the eastern equatorial Indian Ocean. Analysis of the seasons for which the predictions of almost all the models have large errors has suggested the facets of ENSO and EQUINOO and the links with the monsoon that need to be improved for improving monsoon predictions by these models

Application of oxide-metallic catalysts on valve metals for ecological catalysis

Запропоновано спосіб одержання оксидно-металевих каталізаторів методом одностадійного плазмово-електролітичного оксидування вентильних металів для знешкодження токсидів природного та техногенного походження. Обґрунтовано застосування оксидів мангану та кобальту як легуючих компонентів. Встановлено, що одержані оксидні покриви характеризуються високою каталітичною активністю в модельних реакціях конверсії токсичних компонентів, зокрема відпрацьованих газів двигунів внутрішнього згоряння

Fiber optics based surface plasmon resonance for label-free optical sensing

With the advancement in the laser technology and availability of low cost optical fibers, there is an increasing trend towards adoption of optical fibers as sensing element for development of optical sensors probes especially point-of-care sensing for environmental, biomedical and clinical application. Refractive index measurement through surface plasmon resonance has evolved to be, one of the most sensitive transducer for label-free sensing with high sensitivity. Surface plasmon resonance is a surface sensitive optoelectronic phenomenon, where light incident on a plasmonic metal surface at a given angle can excite a surface-bound electromagnetic wave, a surface plasmon. Associated with the surface plasmon is an evanescent field that probes local changes in the refractive index of the ambient medium that are used for monitoring analyte- supramolecular/ bio-molecular ligand interactions. Present review outlines a concise view on theoretical aspects of fiber optics based surface plasmon resonance phenomenon and comprehensive updated review on research and development for progression in the design of fiber optics based SPR sensors