Synthesis of polycalciumphenylsiloxane and composites based on the skeleton of a sea urchin with the resulting polymer

In this work, we obtained polycalciumphenylsiloxane (PCPS) by the interaction of calcium bis (acetylacetonate) with polyphenylsiloxane. The first method consisted in boiling the starting reagents in toluene for several hours; the second was as follows: the mixture of the starting reagents was preliminarily treated mechanically in a ball mill, followed by boiling in toluene for several hours. Two fractions, soluble and insoluble, were isolated in both syntheses. They were investigated using IR, NMR spectroscopy, thermogravimetric analysis, and gel permeation chromatography. It was shown that the insoluble fraction is a mixture of calcium acetylacetonate and polyphenylsiloxane with a small calcium ion content. The soluble fraction is polycalciumphenylsiloxane. The yield of the soluble fraction is higher in the second synthesis method. The polymers obtained in the first and second synthesis methods are similar in composition and structure, which was confirmed by physicochemical methods. Next, the skeleton of the sea urchin Strongylocentrotus intermedius was treated with a soluble fraction in toluene. In this case, a composite was obtained, which was treated with 2–3% hydrochloric acid and then calcined at a temperature of 600 °C. At each stage, the composition of the composites was investigated using elemental analysis and IR spectroscopy. The morphology was investigated using scanning electron microscopy

Oscillatory Signatures in the Raindrop Motion Relative to the Air Medium with Terminal Velocity

This paper aims to study the path oscillations of single, spherical water droplets levitated in a wind tunnel to better comprehend the mechanical motion of small raindrops. The observations were carried out in the Mainz vertical wind tunnel. The discrete, fast Fourier transform was used to determine the oscillatory frequencies of the droplet paths, and the Hilbert transform was applied to analyze their instantaneous frequency stability. Both transversal and streamwise components of the path oscillations are described with typical frequencies of several tens of Hertz. The studied oscillations elongate the paths, reduce the terminal velocity of the smallest droplets, and make the rain droplet fall in a non-uniform motion even after reaching terminal velocity. The terminal velocity can be considered as physically having been reached if our proposed practical criterion is satisfied. From a fluid mechanics perspective, the paper fills an experimental gap in the studies of the paths oscillations of single, liquid spheres of microscopic sizes at low Bond numbers <1 and relatively low Reynolds numbers ~102

Electrochemical Properties of Bismuth Oxide Films on Titanium Formed by Plasma Electrolytic Oxidation

На поверхности титана методом плазменно-электролитического оксидирования (ПЭО) сформированы висмутосодержашие оксидные покрытия из электролитов, содержащих комплексные ионы ЭДТА-Bi3+. Определены электрохимические характеристики – токи обмена, коэффициенты переноса α и β, коэффициенты a и b в уравнении Тафеля. Для полученных систем установлено возникновение аналитического сигнала при комплексонометрическом титровании солей железа (III). Рядом физических методов (сканирующая электронная микроскопия с энергодисперсным анализом и рентгеновская фотоэлектронная спектроскопия) изучены морфология и состав поверхности оксидных покрытий. Найдена корреляция между морфологией, составом поверхности и электрохимическими свойствами образцовBismuth oxide layers on a titanium are formed by a plasma electrolytic oxidation (PEO) method from electrolytes containing complex ions EDTA-Bi3+. Electrochemical characteristics – exchange currents, transport coefficients α and β, a and b coefficients in Tafel’s equation are defined. For the obtained systems occurrence of an analytical signal at complexometric titration of salts of Fe (III) is established. The structural features of surface electrodes have been investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. Correlation between morphology, structure of a surface and electrochemical properties of samples is foun

Electrochemical Properties of Bismuth Oxide Films on Titanium Formed by Plasma Electrolytic Oxidation

На поверхности титана методом плазменно-электролитического оксидирования (ПЭО) сформированы висмутосодержашие оксидные покрытия из электролитов, содержащих комплексные ионы ЭДТА-Bi3+. Определены электрохимические характеристики – токи обмена, коэффициенты переноса α и β, коэффициенты a и b в уравнении Тафеля. Для полученных систем установлено возникновение аналитического сигнала при комплексонометрическом титровании солей железа (III). Рядом физических методов (сканирующая электронная микроскопия с энергодисперсным анализом и рентгеновская фотоэлектронная спектроскопия) изучены морфология и состав поверхности оксидных покрытий. Найдена корреляция между морфологией, составом поверхности и электрохимическими свойствами образцовBismuth oxide layers on a titanium are formed by a plasma electrolytic oxidation (PEO) method from electrolytes containing complex ions EDTA-Bi3+. Electrochemical characteristics – exchange currents, transport coefficients α and β, a and b coefficients in Tafel’s equation are defined. For the obtained systems occurrence of an analytical signal at complexometric titration of salts of Fe (III) is established. The structural features of surface electrodes have been investigated by scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) techniques. Correlation between morphology, structure of a surface and electrochemical properties of samples is foun

Hyperon signatures in the PANDA experiment at FAIR

We present a detailed simulation study of the signatures from the sequential decays of the triple-strange pbar p -> Ω+Ω- -> K+ΛbarK- Λ -> K+pbarπ+K-pπ- process in the PANDA central tracking system with focus on hit patterns and precise time measurement. We present a systematic approach for studying physics channels at the detector level and develop input criteria for tracking algorithms and trigger lines. Finally, we study the beam momentum dependence on the reconstruction efficiency for the PANDA detector