The activation of a series of catalysts with the general formula Ni 0.9 M 0.1 O (M = Co, Ce, Mn, and Zr) synthesized by coprecipitation and the effect of modifying additives on the phase composition and structure of these catalysts were studied. The effect of additives on the initial state of the samples was studied by X-ray diffraction (XRD) analysis, and their role in the process of NiO reduction was studied using in situ XRD analysis and temperature-programmed reduction with hydrogen (TPR-H 2 ). It was found that the modifiers changed the structure and microstructure of the initial samples to increase the specific surface area and decrease the average coherent scattering region (CSR) sizes of NiO. The introduction of Mn and Co led to the formation of substitutional solid solutions with the oxide NiO. For Ce and Zr, the release of the oxide CeO 2 and X-ray amorphous ZrO x was observed. The use of these additives led to an increase in the temperature of NiO reduction to a metallic state compared to that of the massive oxide. In addition, the effect of modifying additives on the particle size of the final metal was revealed. The use of Ce and Mn decreased the average CSR size of Ni by a factor of 2–5 compared to that of massive NiO.

We prepare a series of MnOx–CeO2 catalysts with a molar ratio of Mn : Ce = 3 : 7 by coprecipitation and varying the calcination temperature from 300 to 800°C. The catalysts are characterized by powder X-ray diffraction, low-temperature nitrogen adsorption, and X-ray photoelectron spectroscopy, and the catalytic activity of all samples is tested in the CO oxidation reaction. A (Mn,Ce)O2 solid solution with the fluorite structure forms in all catalysts. Based on the studies performed, a catalyst calcined at 600°C is selected for further studies of the effect of topochemical reduction on the catalytic activity in the CO oxidation reaction by X-ray diffraction in the operando mode. The experiment is carried out sequentially in a stepwise mode: stepwise heating/cooling in a reaction mixture of 1% CO + 2% O2 in the mode 150–175–200–175–150°C (stages 1, 3, and 5); reduction of the sample in a mixture of 10% CO + He at 400°C (stage 2); reduction of the sample in a mixture of 10% H2 + He at 400°С (stage 4). The reductive treatment leads to segregation of the initial (Mn,Ce)O2 solid solution and the appearance of dispersed manganese oxides on the surface, while enrichment of the surface with manganese oxide increases its activity in the CO oxidation reaction.

In this work the activation process and the effect of modifying additives on the phase composition and structure of a series of catalysts with the general composition Ni0.9M0.1O (M = Co, Ce, Mn, Zr) synthesized by co-precipitation were studied. The influence of the additives on the initial state of the samples was investigated by XRD, and their influence on the NiO reduction process was studied by in situ XRD and TPR-H2. It was shown that the introduced modifiers influence on the structure and microstructure of the initial samples, increasing the value of the specific surface and decreasing the average size of NiO CSR. Introduction of Mn, Co leads to formation with NiO oxide of solid solutions of replacement. For Ce and Zr the release of CeO2 oxide and X-Ray-amorphous ZrOx is observed. The use of these additives leads to an increase in the temperature of NiO reduction to the metallic state compared to the massive oxide. In addition, the effect of modifying additives on the particle size of the final metal is observed. The introduction of Ce and Mn decreases the average size of the NiO CSR in 2–5 times compared to the massive NiO.

In this work the activation process and the effect of modifying additives on the phase composition and structure of a series of catalysts with the general composition Ni0.9M0.1O (M = Co, Ce, Mn, Zr) synthesized by co-precipitation were studied. The influence of the additives on the initial state of the samples was investigated by XRD, and their influence on the NiO reduction process was studied by in situ XRD and TPR-H2. It was shown that the introduced modifiers influence on the structure and microstructure of the initial samples, increasing the value of the specific surface and decreasing the average size of NiO CSR. Introduction of Mn, Co leads to formation with NiO oxide of solid solutions of replacement. For Ce and Zr the release of CeO2 oxide and X-Ray-amorphous ZrOx is observed. The use of these additives leads to an increase in the temperature of NiO reduction to the metallic state compared to the massive oxide. In addition, the effect of modifying additives on the particle size of the final metal is observed. The introduction of Ce and Mn decreases the average size of the NiO CSR in 2–5 times compared to the massive NiO.

MnOx-CeO2, MnOx-ZrO2, MnOx-ZrO2-CeO2 oxides with the Mn/(Zr + Ce + Mn) molar ratio of 0.3 were synthesized by coprecipitation method followed by calcination in the temperature range of 400–800 °C and characterized by XRD, N2 adsorption, TPR, TEM, and EPR. The catalytic activity was tested in the CO oxidation reaction. It was found that MnOx-CeO2, MnOx-ZrO2-CeO2, MnOx-ZrO2 catalysts, calcined at 400–500 °C, 650–700 °C and 500–650 °C, respectively, show the highest catalytic activity in the reaction of CO oxidation. According to XRD and TEM results, thermal stability of catalysts is determined by the temperature of decomposition of the solid solution Mnx(Ce,Zr)1−xO2. The TPR-H2 and EPR methods showed that the high activity in CO oxidation correlates with the content of easily reduced fine MnOx particles in the samples and the presence of paramagnetic defects in the form of oxygen vacancies. The maximum activity for each series of catalysts is associated with the start of solid solution decomposition. Formation of active phase shifts to the high-temperature region with the addition of zirconium to the MnOx-CeO2 catalyst.

For the first time, acetylcholinesterase (AChE) biosensors based on mixed carbon nanomaterials (electrochemically reduced graphene oxide (ERGO) and carbon black (CB) particles) were described for the determination of antidementia drugs. Changes in the content of underlying layer allowed varying selectivity and sensitivity of the inhibitor determination. Appropriate limits of detection (LOD) varied in the range from 1 pM to 0.1 nM for donepezil, 5 nM-0.1 mu M for berberine, 0.1-50 nM for huperzine A and 0.1-300 nM for galantamine. Variation in the inhibition measurement parameters can be used for increasing selectivity of the measurements.

For catalysts comprised of mixed manganese-chromium oxides MnxCr3-xO4 (x=0.3-2.7) prepared by Pechini route with Ni and Ru supported by impregnation fundamental factors determining their performance in ethanol steam reforming have been elucidated using combination of structural (XRD, HRTEM), spectroscopic (UV-vis), surface science (XPS, FTIR spectroscopy of adsorbed CO) and kinetic (H-2 and EtOH TPR, oxygen isotope heteroexchange with (CO2)-O-18) methods. The most important feature is strong metal-support interaction stabilizing small clusters of metals/alloys and preventing carbon nucleation. The lattice oxygen mobility and reactivity increased with Mn content. The highest TOF was obtained for (Ni + Ru)-loaded oxide support containing cubic spinel phase of MnCr2O4 composition, which implies a positive effect of Ni-Ru interaction in mixed clusters on catalytic activity. This catalyst has also a high density of active sites, surface enriched by Mn and sufficient oxygen mobility providing coking stability, which makes it attractive for practical application.

Hydrogen generation from tablets of sodium borohydride with chlorides of nickel and cobalt was studied. The nickel catalysts were shown to be less active in the borohydride hydrolysis than the cobalt catalysts. One of the reasons for the lower activity of the nickel catalyst was the presence of hydrogen on its surface, which hampered the adsorption of reactants. The addition of cobalt to the nickel catalyst increases the hydrogen generation rate. This is due to the introduction of active metal with low adsorption capacity for hydrogen and the higher dispersion of the active component.

The work considers the problem of obtaining nanocolloid radiopharmaceuticals (RPs) and studying their functional suitability for diagnosing sentinel lymph nodes (SLN) in cancer patients. Two principal approaches to the formation of technetium-99m-labeled particles based on inorganic and organic matrices were considered when carrying out research to develop methods for the production of nanocolloid RPs. The composition of the reagents and the conditions for obtaining nanocolloid radiopharmaceuticals were determined. The functional suitability of new RPs for scintigraphic diagnostics of sentinel lymph nodes has been studied.

The paper presents the procedure for planning an experiment to create standard sets of reagents for a technetium-99m generator based on glucose derivatives. All stages are presented from researching the required quantities of a substance, a reducing agent, a stabilizer and auxiliary components to developing lyophilized kits and conducting quality control. The radiochemical purity of radiopharmaceuticals prepared on the basis of the developed kits ranged from 90.0 to 99.0%. We also showed the functional suitability of the developed preparations on C57B1/6j mice with an implanted malignant tumor - Lewis lung carcinoma.

One of the challenges of machining process is to improve the quality of machined surface by reducing the vibration of cutting tools. The research aims to suppress vibration using composite boring bars with an enhanced damping capacity. A new design of boring bars with different cross-sections is considered. Static and dynamic behavior of the proposed tools is investigated. A mathematical model for determining the eigenfrequency is proposed, and it is compared with computer simulation and experimental results. The validity of the proposed models is verified by conducting experimental machining tests in order to study the changes in vibro-acoustic signals depending on the cross-sections of the toolholder. The results show that the composite material significantly improves damping of boring bars, which leads to a reduction in the vibration compared to conventional boring bars.