Margarita Skiba, Viktoria Vorobyova, Alexander Pivovarov and Inna Trus
This paper aims to synthesize silver nanoparticles using atmospheric discharge plasma in contact with liquid at different pressure in reactor and to assess their catalytical…
Abstract
Purpose
This paper aims to synthesize silver nanoparticles using atmospheric discharge plasma in contact with liquid at different pressure in reactor and to assess their catalytical properties for reducing 4-nanoparticles (NP).
Design/methodology/approach
The Ag colloidal NPs was rapidly synthesized as a result of non-equilibrium low-temperature plasma formation between an electrode and the surface of AgNO3 solution for 5 min at different pressure in reactor. Synthesized Ag NPs were characterized with common analytical techniques. Ultraviolet–visible (UV) spectroscopy, dynamic light scattering, scanning microcopy analysis were used to study the formation and characteristics of silver nanoparticles.
Findings
The formation of silver colloidal solutions under plasma discharge at different pressure in reactor is characterized by the presence of surface resonance peak in the spectra. Scanning electron microscope (SEM) images confirmed the formation of spherical particles having a size distribution in the range of 15-26 nm. The AgNPs solution showed excellent rapid catalytic activity for the complete degradation of toxic 4-nitrophenol (4-NPh) into non-toxic 4-aminophenol (4-APh) within 18 min.
Research limitations/implications
Further studies are necessary for confirmation of the practical application, especially of deposition Ag NPs on TiO2.
Practical implications
The method provides a simple and practical solution to improving the synthesis of colloidal solutions of Ag NPs for degradation of organic pollutants (4-NPh) in water and wasters water.
Originality/value
Atmospheric discharge plasma in contact with liquid at different pressure can be used as an effective technique for synthesis of nanomaterials with catalytic properties.
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Liliya Frolova, Alexander Pivovarov and Tatyana Butyrina
The purpose of this work is to study the patterns of pigment colour formation and to develop metal compositions for obtaining spinels using the precipitation and heat treatment…
Abstract
Purpose
The purpose of this work is to study the patterns of pigment colour formation and to develop metal compositions for obtaining spinels using the precipitation and heat treatment methods.
Design/methodology/approach
Precursor materials were prepared using co-precipitation method. Phase composition of pigments were determined by X-ray diffraction. Colour of pigments was determined spectrophotometry. Modelling of colour formation was performed using simplex method. Planning in the future to carry out full synthesis of pigments of blue, red and yellow colours.
Findings
The paper deals with the results of theoretical and experimental research on the synthesis pigments of blue, red and yellow colours based on Fe-Co-Al-O spinel. The influence of the chromophore cation content and the heat treatment temperature on optical and colour characteristics of pigments were studied.
Originality/value
The resulting composition-property diagrams make it possible to evaluate the effect of chromophore cations and heat treatment on the colour formation for Fe2O3-Al2O3-CoO system. Crystal-phase composition of the pigments is installed and its relationship with the optical colour characteristics. That makes it possible carry out targeted synthesis of pigments blue, red and yellow colours in further. The phase composition of pigments and its relationship with optical and colour properties has been established thus enabling the directed synthesis of blue, red and yellow pigments.
Kseniia Puzyreva and Nikita Basov
Owing to the climate change, the number of flood hazards and communities at risk is expected to rise. The increasing flood risk exposure is paralleled with an understanding that…
Abstract
Owing to the climate change, the number of flood hazards and communities at risk is expected to rise. The increasing flood risk exposure is paralleled with an understanding that hard flood defense measures should be complemented with soft sociotechnical approaches to flood management. Among other things, this involves development of a dialogue between professionals and flood-prone communities to ensure that the decisions made correspond to the peculiarities of local socioenvironmental contexts. However, in practice, establishment of such a dialogue proves to be challenging. Flood-prone communities are often treated as mere recipients of professional knowledge and their local knowledge remains underrated. Building on an illustrative case study of one rural settlement in North-West Russia, we examine how at-risk communities develop their local knowledge and put it to use as they struggle with adverse impacts of flooding, when the existing flood protection means are insufficient. Our findings showcase that local knowledge of Russian flood-prone communities is axiomatic and tacit, acquired performatively through daily interaction of local residents with their natural and sociotechnical environments. Even if unacknowledged by both the local residents and flood management professionals as a valuable asset for long-term flood management, it is local knowledge that informs local communities' practices and enables their coexistence with the treacherous waters.
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RUSSIA: Opposition will be dismembered case by case