Pt-CeO2-based composites in environmental catalysis: A review

The Pt–CeO2-based composites have brought about a vivid research interest due to their use in advanced combustion engines, proton-exchange membrane fuel cells, etc. Complementing features of Pt and ceria particles cause numerous applications of such composites in environmental catalysis science and technology. The present review summarizes recent advances in Pt–CeO2 chemistry and discusses the following key aspects: (1) catalyst preparation, including Pt and Ce-MOF-derived precursors, and treatment methods, (2) Pt-related factors: size, including single-atom formulations, and state, (3) CeO2-related factors: morphology, surface defects, and derived features, (4) modification of catalyst composition, including the formation of bimetallic particles, (5) nature and structure of active sites, (6) features of metal–support interaction. The range of covered environmental catalytic applications includes oxidation processes (CO oxidation, VOCs abatement, soot oxidation, combustion of vehicle exhausts, etc.), reduction of nitroaromatics, CO2 utilization (dry reforming of alkanes, CO2 reduction, etc.), and photocatalytic reactions

Research of luminophores afterglow under influence of pulsed X-ray radiation of nanosecond duration

The work describes an investigation of afterglow of various luminophores under influence of pulsed X-ray radiation of nanosecond duration. As a source of radiation a pulsed X-ray "Yasen 01" apparatus is applied. Maximum impulse current of an X-ray tube is 300 A. Maximum electron energy is 120 keV. Half-height pulse duration of an X-ray burst is about 30 ns. A pulse repetition rate is up to 4 kHz. Two types of X-ray luminophores based on gadolinium oxysulfide Gd 2 O 2 S:Tb and cesium iodide CsI:Tl have been investigated. The novelty of the work is use of a fast-acting solid-state semiconductor photomultiplier. It allows recording changes of luminophores luminosity in the nanosecond time range. The photomultiplier is characterized by having two discreet outputs for measuring quickly and slowly time-changing light flows. Presence of two signal outputs allows recording changes of luminophores luminosity both during fast nanosecond excitation and during long-time afterglow. Obtained data about the nature of afterglow of investigated luminophores makes it possible to select the best one for use in conjunction with a pulsed X-ray apparatus with a high pulse repetition rate. © Published under licence by IOP Publishing Ltd

The Image of a Hero in Western and Russian Social Advertising

The article is devoted to a comparative study of the image of a hero / superhero in Russian and Western social advertising. The relevance of the study is determined by the contrast of globalization processes, on the one hand, and the desire to preserve nationally oriented values, on the other. The novelty of the study lies in comparing the ideological and linguocultural representations of the image of the hero / superhero, reflected in the socio-advertising text. The results of the study are based on a contextual analysis of the geroy and hero tokens, supergeroy and superhero , as well as non-verbal symbols associated with these concepts presented in the structure of creolized advertising text. In the structure of the image of the hero / superhero, both semantic components (for example, a military metaphor) and specific representations that are determined by the cultural code and ideological identifications, are revealed that are common for Russian and Western social advertising. It is proved that those components of the hero’s image that are connected with the axiology of culture (“peaceful heroism” interpreted as socially approved behavior in general) are more likely to have positive connotations than those that are due to ideological ideas. It is concluded that the image of a superhero in Russian linguistic culture, on the one hand, is understandable and even already familiar, on the other hand, it is rejected as a representative of an alien culture and ideology

Cr2O3/Al-Al2O3 composite catalysts for hydrocarbons dehydrogenation prepared from aluminum nanopowder

Aluminum nanopowder (10–150 nm) was treated hydrothermally in mild conditions (60–95 °C, at atmospheric pressure), and an aluminum-alumina composite with high porosity and specific surface area was obtained. Cr2O3/Al-Al2O3 catalysts were prepared using the aluminum-alumina composite by impregnation techniques and tested in dehydrogenation of C4-hydrocarbons. It was shown that aluminum-alumina composites had high chemical and phase purity, specific surface area of 150–350 m2/g and the average pore size of 8–13 nm, that is favorable for application as support for catalysts. Cr2O3/Al-Al2O3 catalysts had high activity and selectivity in dehydrogenation of n- and i-butane (conversion of 44–80 mol.% and selectivity >85% at temperatures of 540–610 °C), that is comparable ones for commercial catalysts for CATOFIN, STAR processes

Atmospheric Pressure Plasma Generation System Based on Pulsed Volume Discharge for the Biological Decontamination of a Surface

The research introduces a system for pulsed volume discharges ignition at atmospheric pressure within gaps reaching 125 mm. The corona discharge is used for the volume discharge initiation. A damping oscillations pulse generator is used as a high-voltage power supply. The pulse repetition rate reaches 1 kHz, while the rate of damping high-frequency harmonic oscillations can reach megahertz units. The volume discharge electric and spectral characteristics were analyzed. The study revealed that O2+ emission spectrum dominates in the UV region. The potential of using pulsed volume discharge for cleaning biological surfaces was demonstrated in the research. The survival rate for E. coli under the influence of 15 seconds long pulsed volume discharge has decreased by 30 times