SILICON-VALUE AND USE IN A LIVING ORGANISM

Results of clinical practice demonstrate that concerning of silicon the mistake in assessment of the importance of this element in food of animals was made. The silicon concentration in foodstuffs considered being a great deal and its requirements of animals are fully satisfied. Therefore, even in norms (2002) consists no any information about silicon. Accordingly, specialists of cattle breeding also do not control silicon concentration in diets. The last years established its influence on many aspects of metabolism in organism and animal productivity. Established factors of influence on element assimilation that is very important at phone of spreading cattle collogenosis, that promote emergence and spread of various diseases of a noncontagious and infectious etiology, including diseases of fingers and hooves.

Silicon Modulates Molecular and Physiological Activities in Lsi1 Transgenic and Wild Rice Seedlings under Arsenic Stress

Arsenic is one of the most dangerous metalloids, and silicon is a helpful element supporting plants to withstand stress. In this study, three factors were considered, including rice accessions with three different lines, including Lsi1-RNAi line (LE-R), Lsi1 overexpression line (LE-OE), and their wild type (LE-WT), and silicon and arsenic treatments with two different levels. Analysis of variance in dry weight biomass, protein content, arsenic, and silicon concentration has shown a significant interaction between three factors. Further analysis showed that the silicon concentration of all rice seedlings under silicon treatments increased significantly. The LE-OE line has shown a higher ability to absorb silicon in hydroponic conditions than the wild type, and when the seedlings were exposed to arsenic, the concentration of arsenic in all lines increased significantly. Adding silicon to over-expressed rice lines with the Lsi1 gene creates better arsenic resistance than their wild type. These findings confirmed antagonism between silicon and arsenic, and seedlings exposed to arsenic showed a reduction in silicon concentration in all rice lines. RNA-seq analysis showed 106 differentially expressed genes in the LE-OE line, including 75 up-regulated genes and 31 down-regulated genes. DEGs in the LE-R line were 449 genes, including 190 up-regulated and 259 down-regulated genes. Adding treatment has changed the expression of Calcium-binding EGF domain-containing, Os10g0530500, Os05g0240200 in both LE-OE and LE-R roots. They showed that transgenic cultivars were more resistant to arsenic than wild-type, especially when silicon was added to the culture medium.

Effect of Silicon Concentration on the Properties of Al-Cr-Si-N Coatings Deposited Using Cathodic Arc Evaporation

The current market requirements are related to the introduction of new protective coatings for tools and machine parts with much better performance properties. These requirements are met by the AlCrSiN coatings; however, knowledge on the adhesion of these coatings to the substrate, as well as on their corrosion resistance, is deficient. The article presents the results of technological works on the coating deposition from AlCrSi cathodes with a silicon concentration from 0 at% to 10 at% by the cathodic arc evaporation and the results of systematic studies of their structure, mechanical, tribological and electrochemical properties. A correlation between the above-mentioned properties and the silicon concentration in the AlCrSiN coatings has been found and discussed. The coatings formed from cathodes containing less than 5 at% Si crystallize in the cubic structure. The size of the crystallites decreases with the silicon concentration increase. The coatings are characterized by a high hardness with a maximum of about 37 GPa (2 at% Si). The adhesion of the coatings is almost independent of the concentration of silicon. The wear rate is about one order of magnitude higher for coatings deposited from cathodes with a silicon concentration of 5 at% and 10 at% compared to a coating with a lower silicon concentration. This finding is consistent with the results of corrosion resistance studies. The coating deposited from the cathode with 10 at% of silicon exhibits the best anticorrosion properties against the salt solution.

A Study of Nickel and Iron Reduction Silicothermic Process by Thermodynamic Simulation

The results of studying the effect of silicon concentration of ferrosilicon: FeSi5 (5% Si), FeSi20 (20% Si), FeSi35 (35% Si), FeSi50 (50% Si), FeSi65 (65% Si) on the degree of nickel (ηNi) and iron (ηFe) reduction of the CaO-SiO2-MgO-Al2O3-FeO-NiO-P2O5 multicomponent oxide system at a temperature of 1500 °C by thermodynamic simulation are given2. The HSC Chemistry 6.12 software package developed by Outokumpu (Finland) was used for the simulation. The chemical compounds Ni3Si and Ni5Si2 with the corresponding thermodynamic characteristics are entered into the database. The calculations were performed by the “Equilibrium Compositions” subroutine at a gas pressure of 1 atm, containing 2.24 m3 N2, as a neutral additive. The obtained modeling results indicate the thermodynamic possibility of nickel and iron reduction from the CaO-SiO2-MgO-Al2O3-FeO-NiO-P2O5 oxide system by silicon of ferrosilicon. The degree of iron reduction increases from 88.8 to 91.4%, with an increase in the silicon concentration of ferrosilicon [Si]FeSi from 5 to 65%. The degree of nickel reduction with an increase in the silicon concentration of ferrosilicon remains almost unchanged and amounts to 99.8-99.7%. The degree of use of silicon is 92.1–94.5%. The chemical composition of the complex alloy – ferrosiliconickel is determined. The obtained simulation results can be used to develop the technology for producing ferrosiliconickel from nickel ore by silicothermic method.