Synthesis and Application of Domestic Glassy Carbon TiO2 Nanocomposite for Electrocatalytic Triclosan Detection

Nanoparticles of TiO2 are suitable for many catalytic and photocatalytic applications due to their extraordinary properties such as superhydrophobicity, semiconductivity, electron-rich, and environmental compatibility. The main crystalline phases of TiO2, anatase, and rutile possess different crystal structures, crystallinity, crystalline sizes, and specific surface areas, and these characteristics directly affect the catalytic performance of TiO2. In the present study, domestic carbon material enhanced with TiO2 nanoparticles was synthesized and used for the construction of a modified carbon paste electrode. The electrocatalytic activity of the modified electrodes was investigated depending on the TiO2 crystalline phases in the electrode material. Furthermore, the obtained working electrode was utilized for triclosan detection. Under optimized experimental conditions, the developed electrode showed a submicromolar triclosan detection limit of 0.07 µM and a wide linear range of 0.1 to 15 µM. The relative standard deviations for repeatability and reproducibility were lower than 4.1%, and with satisfactory selectivity, the proposed system was successfully applied to triclosan monitoring in groundwater. All these results confirm that the sustainable production of new and domestically prepared materials is of great benefit in the field of electrocatalysis and that the morphology of such produced materials is strongly related to their catalytic properties

Assessment of the Macro-and Microelement Composition of Fly Ash from 50-Year-Old Ash Dumps in the Middle Urals (Russia)

The paper considers the macro-and micro-element composition of two ash dumps in the Middle Urals, where meadow and forest communities have been spontaneously forming for 50 years, as well as the effect of the plants on the changing composition of the ash. Higher contents of Cu, Co, Sn, Ga, and Yb were found in the deep ash layers of both dumps, while in the upper 20-cm layer, the trace element composition depended on the influence of different plant communities. Higher contents of Sr, Cr, Ni, Sn, and Co were revealed under meadows, and Ba, Zr, and La were found under the forest. The levels of element accumulation in the aboveground and underground parts of dominant plants were revealed. Increased content of Be, Ce, Ga, La, Sc, Y, and Yb was detected in areas where meadow plants were dominant and Zn and Ba in forest areas. The toxic elements Cd and Pb were highly accumulated in both communities, whereas Co was found only in meadows. The studied materials can serve as a base to assess the feasibility of processing and/or utilizing fly ash from ash dumps in the Middle Urals and similar ash dumps in other regions situated in the southern taiga. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.Funding: This work was supported by the Ministry of Science and Higher Education of the Russian Federation [project number 121031700309-1 in ISSA SB RAS and project number FEUZ-2021-0014 in URFU]

Natural Forest Colonisation and Soil Formation on Ash Dump in Southern Taiga

Ash dumps occupy significant areas around the world and make a negative influence on the environment. This effect is decreased by their natural colonisation determined by the bioclimatic conditions of the area. The purpose of the current study was to identify the structure of the forest communities and the initial stages of soil formation on the ash dump in southern taiga. This study was carried out on three sites in the forest phytocoenosis formed in the process of revegetation of the Verkhniy Tagil Power Station ash dump over 50 years, as well as on two background forest sites in the Middle Urals. Complex geobotanical and soil studies were carried out. The results of the study show that forest phytocoenoses with a predominance of hardwood species (Betula pendula Roth and Populus tremula L.) and a small admixture of coniferous species can form on the non-recultivated ash dump within 50 years in a boreal zone. In total, the studied mixed forest phytocoenoses are similar in composition to zonal secondary forests, but differ by having lower height and diameter of the stand, as well as herb–shrub layer coverage. Their species density and floristic richness are also lesser. The study proved that the process of soil formation is also proceeding according to the zonal type in the ash substrate under forest communities. The results of the study can be applied to justifying the forecasts of ecosystem restoration on the technogenic substrate, as well as for the species selecting for their recultivation in the studied area and similar to it. © 2020 by the Committee on Forestry Sciences and Wood Technology of the Polish Academy of Sciences and the Forest Research Institute in S´kocin Stary

A Multifractal Approach to the Analysis of Size-Frequency Distributions of Craters on Planetary Bodies

We have developed a multifractal approach to the analysis of size-frequency distributions of craters on planetary surfaces. We demonstrate the use of the method and study the relationship between the multifractal spectrum and the size-frequency distribution of craters. We showed that if the multifractal spectrum of a crater size distribution can be approximated by a parabolic function, the size-frequency distribution of craters are lognormal. For demonstration of our approach we analyzed distributions of craters on selected Phobos areas using Mars Express HRSC images. We demonstrated that the distributions of the craters are very well approximated by lognormal curves, as our technique suggests. Using the multifractal approach we show that size-frequency distributions of small craters on the sub-Mars and anti-Mars sides of Phobos' surface appear to be different. We suggested that this approach may be used for analysis of size-frequency distributions of craters on other planetary bodies. This research was funded by the Ministry of Education and Science of the Russian Federation (MEGA-GRANT, Project name: "Geodesy, cartography and the study of planets and satellites", contract No. 11.G34.31.0021)

Is Nuclear Anarchy Sustainable? A Temporal Approach

The article develops a novel temporal approach to the sustainability of nuclear anarchy. The extant literature offers two opposite perspectives on the topic: some scholars argue that nuclear anarchy is unsustainable, since it will inevitably either lead to a catastrophic nuclear war or evolve into a hierarchical world order. Their opponents doubt the inevitability of nuclear war in a system of sovereign states and/or its catastrophic nature. However, the debate, as it stands now, ignores the fact that both technology and social structures are embedded in – and mediated by – cultures and worldviews. In particular, both nuclear weapons and interstate anarchy are embedded in specific temporalities.Taking this fact into account, we identify and compare perceptions of time that are interrelated with nuclear weapons, on one hand, and international anarchy, on the other. The article reveals a temporal contradiction of nuclear anarchy: while nuclear weapons imply a potential finitude of humanity, the system of sovereign states is intrinsically connected with an indefinite temporality. We derive two theoretical implications form the concept of temporal contradiction. First, a realization of finite temporality should subvert the legitimacy of an anarchic world order and encourage limitations on national sovereignty. Second, international anarchy should ‘eternalize’ nuclear weapons, i.e., reinterpret them as compatible with the eternity of human civilization. Familiar events of nuclear history including early attempts to establish international control of nuclear energy, the Strategic Defense Initiative, and the evolution of the anti-nuclear movement are interpreted here as empirical evidence in favor of the theoretical implications described above.Thus, the concept of temporal contradiction provides another argument in favor of the idea that nuclear anarchy is unsustainable in the long run, since the proliferation of the finite temporality leads to international hierarchy, whereas persistent indefinite temporality masks the severity of the nuclear threat, making nuclear war more conceivable and probable

The Phobos information system

We have developed a Geo-information system (GIS) for Phobos, based on data from the Mars Express and Viking Orbiter missions, which includes orthoimages, global maps, terrain- and gravity field models, all referenced to the Phobos coordinate system. The data are conveniently stored in the ArcGIS software system, which provides an environment for mapping and which allows us to carry out joint data analysis and miscellaneous data cross-comparisons. We have compiled catalogs of Phobos craters using manual and automated techniques, which includes about 5500 and 6400 craters correspondingly. While crater numbers are biased by available image data resolution and illumination, we estimate that our catalog of manually detected craters contains all Phobos craters with diameters D>250 m which is a total of 1072 and catalog of automated detected craters are complete for craters D>400 m (360 craters). Statistical analysis of these large craters reveals a surplus of craters on the anti-Mars hemisphere, whereas differences in crater abundance between leading and trailing hemisphere cannot be confirmed. This in contrast to previous papers, where no such asymmetry was found ( Schmedemann et al., 2014). But we cannot rule out remaining biases due to resolution, viewing angles or illumination effects. Using digital terrain model (DTM) derived from photogrammetry image processing we estimate depths of 25 craters larger than 2 km using geometric and dynamic heights (for discussion of Phobos crater morphometry see Kokhanov et al., 2014). We also have compiled catalogs of lineaments, and boulders. In particular, we mapped 546 individual grooves or crater chains, which extend in length from 0.3 km to 16.2 km. We identified and determined the sizes and locations of 1379 boulders near crater Stickney. Cross-comparisons of gravity field models against distribution patterns of grooves and boulders are currently under way and may shed light on their possible origins. Finally, we have developed a Geo-portal, which allows the science community to conveniently search for, analyze, and download data of interest from our system. Additionally we provide access to color electronic maps (e-maps) with support for layers based on Phobos geodatabase and ArcGIS tools