Here, we report, for the first time, on the catalytic hydrogenation of CO2 to methane at atmospheric pressure. For the preparation of hydrogenation catalysts based on Ni and Fe metals, a convenient method is developed. According to this method, low-temperature reduction of the co-precipitated Ni and Fe oxides with hydrogen gives the effective and selective bimetallic Ni[Formula: see text]Fe[Formula: see text], Ni[Formula: see text]Fe[Formula: see text] and Ni[Formula: see text]Fe[Formula: see text] catalysts. At the temperature range of 300–400[Formula: see text]C, they exhibit a high efficiency of CH4 production with respect to monometallic Ni and Fe catalysts. The results imply a synergistic effect between Ni and Fe which caused the superior activity of the Ni[Formula: see text]Fe[Formula: see text] catalyst conversing [Formula: see text]% of CO2 into CH4 at 350[Formula: see text]C. To adapt the Ni–Fe catalysts in the industry, the effect of two different carriers on the efficiency of the alumina-supported Ni[Formula: see text]Fe[Formula: see text] catalyst was investigated. It is found that the Ni[Formula: see text]Fe[Formula: see text]/[Formula: see text]-Al2O3 catalyst effectively conversed CO2 giving 100% methane yield already at 275[Formula: see text]C.

Catalytic activity, phase composition, and morphology of binary NiFe metallic systems in CO2 hydrogenation were investigated. High methane yield was detected in the region of high Ni content, except the sample with 75% of Ni which has shown a sharp drop in activity. By means of scanning electron microscopy-energy dispersive X-ray and X-ray diraction methods the dierences in surface structuring of active (Ni80Fe20) and inactive (Ni75Fe25) catalysts were revealed. High methane yield for the former might be explained by defective porous supercial layer of catalyst grains, whereby for the latter the specic surface is diminished due to sintering.

Cardiovascular diseases are the most common human diseases, hence, the production of cardiological (in particular, anti-arrhythmic) medications from the natural sources is an ever-actual task. Rauwolfia serpentina Benth. is a tropical fruticose plant that is able to produce and concentrate indole alkaloids, especially ajmaline and its derivatives, which are the most effective medications against ventricular arrhythmia with low side effects. Aim of the study. Determination of the qualitative and quantitative content of indole alkaloids in cell biomass of Rauwolfia serpentina tissue culture, obtained by the prolonged in vitro growth. Materials and methods. Object: cell biomass of Rauwolfia serpentina tissue culture (K-27 strain), obtained by methods of long-term cell selection in vitro. Alkaloids content determination: TSQ Vantage LC-MS (ThermoFischer Scientific). Results. 20 indole alkaloids are found in cell biomass of Rauwolfia serpentina tissue culture (K-27 strain). The highest content is registered for ajmaline and its derivatives (0.690 % mass. for ajmaline). The contents of reserpine and yohimbine were found to be as low as 0.009 % and 0.020 %, respectively. Conclusions. It is established that the content of indole alkaloids is higher in K-27 strain in comparison to natural plant and is stable over more than 30 years of its growth. Total alkaloids content was found to be 2.8 % of dry cell biomass, and total ajmaline-type alkaloids content (including ajmaline) was found to be 1.6 % of dry cell biomass. In contrast, the total alkaloid contents in the natural plant material is reported to be in the range of 0.8–1.3 %.

The paper presents results of research on the effects of mechanical stresses on the magnetostrictive properties of 13CrMo4-5 steel. Measurements of stress dependence of magnetostriction fill the gap in the state of the art enabling description of relationships between stresses applied to the samples and its magnetoelastic and magnetostrictive properties. Performed studies represent the starting point for development of unified model of both Villari (magnetoelastic) and Joule (magnetostrictive) effects under stresses in steels. The formulated model will be the basis for the development of generalized methods of interpreting the results of non-destructive testing of the state of the internal stresses in steels based on these phenomena.