This update includes the literature related to the inert anodes which were published in the past decade. The metallic anodes are widely regarded as promising candidates to replace the carbon anodes due to its attractive properties like good electrical conductivity, easy to manufacture and high resistance to high thermal shocks. The metals have been tested in pure state and alloy (binary, ternary) form. The oxide scale formed on the anode surface acts as a barrier between the electrolyte and the anode, which protects the anode from being dissolved. The layer of molten fluorides is formed between the scale and the metal anode after a certain time of polarization, and the oxide scale acts as a bipolar electrode. Metal like Cu is reduced at the internal side of the scale. This paper elaborates the effects of various parameters on the performance of the anode. Cu-based alloys (Cu – Ni – Fe and Cu – Al) have shown promising results and could perform well in low-temperature electrolytes. It has been well established that the Cu content in Cu – Ni – Fe and Cu – Al alloys plays a major role in the metal dissolution as the CuO/Cu2O scales formed on the outer layer act as a sacrificial one. The corrosion rate of an anode can be reduced by decreasing the operating temperature, which is possible by using the KF – AlF3 melts. The use of suspensions can increase the purity of the produced metal by stopping the anode products to come in contact with cathode metal. Many industries including RUSAL and ELYSIS are still conducting a considerable amount of research to develop an inert anode and are expecting to have a carbon-free cell in the nearest future. The work is performed as a part of the state assignment for the science of Siberian Federal University, project number FSRZ-2020-0013. Use of equipment of Krasnoyarsk Regional Center of Research Equipment of Federal Research Center “Krasnoyarsk Science Center SB RAS” is acknowledged.
An expression is obtained for the reflection coefficient of circularly polarized light normally incident on the film of a cholesteric liquid crystal with a variable helix pitch. It is shown that, in the case of a single defect (local change in the helix pitch), the spectrum of light reflection from a cholesteric acquires a dip corresponding to the defect mode. New qualitative features appear in the reflection spectrum of a cholesteric with two defects as the distance between them varies.
The features of light propagation in plant leaves depend on the long-period ordering in chloroplasts and the spectral characteristics of pigments. This work demonstrates a method of determining the hidden ordered structure. Transmission spectra have been determined using transfer matrix method. A band gap was found in the visible spectral range. The effective refractive index and dispersion in the absorption spectrum area of chlorophyll were taken into account to show that the density of photon states increases, while the spectrum shifts towards the wavelength range of effective photosynthesis.
The temperature dependence of the optical transmission spectrum of a one-dimensional multilayer photonic crystal structure with a central defect layer has been studied. The defect was represented by a nematic liquid crystal (5CB) layer with a homeotropic orientation. It is shows that the defect modes exhibit a 10-nm spectral shift due to a change in the refractive index of the liquid crystal in the course of heating-induced transition to the isotropic phase. A comparison of the experimental data to the results of heating-induced transition to the isotropic phase. A comparison of the experimental data to the results of numerical analysis shows the importance of allowance for the decay of defect modes.
Our current study aimed to adapt a bioluminescent bacteria-based bioassay to monitor the bioeffects of gold nanoparticles (AuNPs). Luminous marine bacteria Photobacterium phosphoreum and AuNPs modified with polyvinylpyrrolidone were employed; low-concentration (≤10−3 g/L) bioeffects of AuNPs were studied. Bioluminescence intensity was used as an indicator of physiological activity in bacteria. Two additional methods were used: reactive oxygen species (ROS) content was estimated with a chemiluminescent luminol method, and bacterial size was monitored using electron microscopy. The bacterial bioluminescent response to AuNPs corresponded to the “hormesis” model and involved time-dependent bioluminescence activation, as well as a pronounced increase in the number of enlarged bacteria. We found negative correlations between the time courses of bioluminescence and the ROS content in bacterial suspensions, demonstrating the relationship between bioluminescence activation and bacterial ROS consumption. The combined effects of AuNPs and a beta-emitting radionuclide, tritium, revealed suppression of bacterial bioluminescent activity (as compared to their individual effects) and a reduced percentage of enlarged bacteria. Therefore, we demonstrated that our bacteria-based bioluminescence assay is an appropriate tool to study the bioeffects of AuNPs; the bioeffects can be further classified within a unified framework for rapid bioassessment.
The effect of surface relief profiles of alkanoate-based bionanofilms to the monocyte-macrophages (MN-MPhs) from peripheral blood of patients with atherosclerosis was studied in vitro. Patients were subjected to coronary stenting. Cell morphology and phenotype (expression of CD antigens, levels of production of marker cytokines) in vitro were analyzed before and after the installation of stents. It was shown, that the mean square roughness (Rq) of the bionanofilms determined the variability of cell morphology, CD antigens spectraand activity of production interleukins-6 and -10. Also, it was revealed, that the “activity” of the surface topography of biopolymer substrates depends on the functional state of MNs, isolated in different time points: Before and after stenting the ratios of cell morphotypes and production of cytokines in MN-MPhs differed significantly.