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We consider the transfer to a given orbit of a controlled spacecraft whose dynamics is described by the mathematical model of motion in a gravitational field with one attractive center. We propose a class of engine-thrust positional controls dependent on the problem parameters that solve the controllability problem for a given target orbit. The trajectory of motion of a phase point under such control is determined on an infinite time axis. On the initial time interval, the trajectory reaches a neighborhood of the target set, and thereafter it moves in this neighborhood asymptotically approaching the target. The positional control is derived in analytical form. Calculation results are reported for the positional control and the trajectories of motion using different test parameters and different types of spacecraft target trajectories. [ABSTRACT FROM AUTHOR]

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Production of waxes from spent perlite, which is a waste of sunflower oil winterization, is studied. Winterization is characterized by significant losses of oil with filter powders, and waste utilization is an environmental and economic problem. At the same time, winterization waste contains valuable components – wax and oil, which can be used in different ways. The content of waxes in spent perlite using hexane (18 %), as well as the quality indicators of the obtained wax: melting point 70 °C, saponification number 115 mg KOH/g, acid number 2.6 mg KOH/g, mass fraction of moisture 0,82 % are determined. Spent perlite was treated with a solution of sodium chloride during boiling, settling of the obtained mass, washing and drying of wax. The dependence of the yield and melting point of the extracted waxes on the processing parameters: the concentration of sodium chloride solution, temperature and duration of settling is found. Rational conditions for spent perlite processing are determined: the concentration of sodium chloride solution – 7.5 %, settling temperature – 20 °C, settling duration – 10 hours. The experimentally determined wax yield at this point is 14.3 %. Quality indicators of the wax sample obtained under rational conditions are studied: melting point 68 °С, saponification number 110 mg KOH/g, acid number 2.8 mg KOH/g, mass fraction of moisture 0.85 %. These values correlate with the data for wax extracted using hexane, as well as with reference data on the quality of beeswax and sunflower wax. The data obtained allow recycling spent perlite without organic solvents, which makes the process more environmentally friendly and cost-effective, as well as solves environmental problems associated with the utilization of winterization waste. [ABSTRACT FROM AUTHOR]

This study has established patterns in the plasmochemical activation of technological solutions in the process of malt production. Of importance is the application of innovative technologies to purify water and technological solutions used at malt enterprises that consume large quantities of water resources. A promising technology is the plasmochemical treatment of water and technological solutions in order to purify them and, partially or completely, destroy pathogenic microflora. Due to the use of plasmochemical activation, it has become possible not only to improve the malting process but also to reduce the consumption of water resources for technological purposes by 2‒3 times. This is achieved by improving the technological malting process and by the possibility of reuse of wastewater after its filtering and plasmochemical treatment. The experimental laboratory tests have proven the effectiveness of using plasmochemical activation of technological solutions in order to improve the qualitative indicators of wastewater and the possibility of reuse of such solutions after their plasmochemical activation. Applying the proposed method for treating technological solutions decreased the level of contamination of wastewater from malt production. Sewage contamination after activation decreased. Thus, pollution indicators decreased as follows: per dry residue – by 65‒95 %; the content of suspended substances – by 33‒66 %; residue after roasting – by 58‒79 %; total nitrogen – by 58‒80 %; P2O5 (phosphorus) – by 75‒88 %; K2O (potassium) – by 75‒92 %; CaO (calcium) – by 81‒92 %; Na2O – by 67–83 %; Cl- – not detected; oxidation – by 78‒95 %; BOC5 (biochemical oxygen consumption) ‒ by 92‒97 %; pH became alkaline. In plasmochemical treatment, there is a disinfection of wastewater, namely, during an activation mode of 60 min the phytopathogenic microflora (Aspergillus, Alternaria, Penicillium, Fusarium, Mucor) were destroyed. This indicates the effectiveness of the purification and decontamination of technological solutions. Its application is the key to the environmental safety of malt production when all its stages meet the requirements of "green" technologies [ABSTRACT FROM AUTHOR]

Based on an analysis of forecasting models of the state of surface objects, this paper has proven that it is advisable, when forming a system of operational prediction and evaluation of anthropogenic loads, to apply simpler models that make it possible to promptly conduct calculations. As an approach to the operative forecasting of anthropogenic loading, the application of an approximately necessary level of the reduction of harmful influence on the site of a surface water object in terms of pollutants received has been suggested. Based on a retrospective analysis of data, the mathematical modeling of the indicators of the Dnipro river ecological condition has been performed. It has been determined that the dependence of an increase in the pollutant concentrations on an increase in its mass, within the sections of a watercourse bounded by existing stationary sites, is described by a linear dependence. An analysis of the derived dependences has made it possible to establish that regardless of the type of pollutant, they have IV characteristic points that allow the rapid prediction of an increase in the mass flow rate of the examined contaminating substance and a change in its concentration. It has been established that at equal values of increasing concentrations for non-conservative substances, the increase in the mass flow rate would be less than that under the conditions of “clean dilution”. In other words, at an actual water object, increasing the Sp concentration amplifies the natural processes of self-purification. The adequacy of the proposed approach has been tested at an actual surface water object, which has made it possible to establish the linear dependences for a change in the content of sulfates: ΔCsulfate=0.022∙Δmsulfate–0.001 and chlorides: ΔCchloride=0.0143∙Δmchloride–0.033. In its turn, the dependence of sulfate content on chloride content is as follows: ΔCsulfate= =1.559∙Δmchloride+2.286. It has been found that for a section of the watercourse in the Dnipro river the linear dependence for phosphates takes the following form: ΔCphosphate=0.019∙Δmphosphate–0.020; for sulfates: ΔCsulfate=0.022∙Δmsulfate–0.001; for chlorides: ΔCchloride= =0,0143∙Δmchloride–0,033. The dependence of phosphate content on sulfate content takes the following form: ΔCphosphate= =0,066∙ΔCchloride+0,422ΔCsulfate–0,017. These equations make it possible in the first approximation to calculate an increase in the concentration of a single pollutant under the condition that the gain in the concentration of another one is known, which reduces data volumes and improves the efficiency of forecast calculations. [ABSTRACT FROM AUTHOR]

We construct a mathematical model of quadcopter flight and design a positional control that solves the terminal control problem in the presence of a disturbance parameter. The study relies on the results of [6-9] and provides sufficient existence conditions for a positional control that solves the control problem for a class of boundary conditions. [ABSTRACT FROM AUTHOR]

The Russian language, as the state language, is given an honorable and important role, uniting all nationalities together. For its mission to serve the unity, solidarity, and mutual understanding of all the peoples of Russia, a mandatory national educational program has been approved, operating throughout the territory of the Russian Federation. The present article is dealing with the problem of mastering the Russian language. The goal of the research is to study the etiology and specifics of writing disorders in primary school children studying at general education school and to develop differentiated strategies for teaching pupils with various manifestations of dysgraphia. Methods used during the preparation of the article included theoretical research, such as learning, generalization, analysis, synthesis, axiomatics, as well as empirical techniques, namely, observation and comparison. Results and novelty of the research consist of clarifying information about the state of the problem of writing disorders in contemporary schoolchildren, updating scientific ideas about the contingent of primary school children in need of correctional assistance from specialists; applying an interdisciplinary approach to the study of the etiology, mechanisms, causes, and specifics of various manifestations of dysgraphia in primary general school children; supplementing the scientific data on the impact of didactogenia on the quality of learning writing and the formation of dysgraphia in pupils with difficulties in the assimilation of the program learning material on the Russian language; as well developing high-performance speech technologies for the early detection and elimination of violations of written language and difficulties in learning academic courses of the Russian language.

The article presents the attitude of prisoners of the past centuries in Russia to punishment, their fate, which they represented in the form of song creation and various metaphorical images. These images have passed through time and are associated with the perception of the prison as a special space. Therefore the authors use already described examples how a prison could look at the end of the Middle Ages.

Enzymes generally display strict stereospecificity and regioselectivity for their substrates. Here by using FAD-dependent human acetylpolyamine oxidase (APAO), human spermine (Spm) oxidase (SMOX) and yeast polyamine oxidase (Fms1), we demonstrate that these fundamental properties of the enzymes may be regulated using simple guide molecules, being either covalently attached to polyamines or used as a supplement to the substrate mixtures. APAO, which naturally metabolizes achiral N 1 -acetylated polyamines, displays aldehyde-controllable stereospecificity with chiral 1-methylated polyamines, like (R)- and (S)- 1-methylspermidine (1,8-diamino-5-azanonane) (1-MeSpd). Among the novel N 1 -acyl derivatives of MeSpd, isonicotinic acid (P4) or benzoic acid (Bz) with (R) -MeSpd had K m of 3.6 ± 0.6/1.2 ± 0.7 µM and k cat of 5.2 ± 0.6/4.6 ± 0.7 s -1 respectively, while N 1 -AcSpd had K m 8.2 ± 0.4 µM and k cat 2.7 ± 0.0 s -1 On the contrary, corresponding (S) -MeSpd amides were practically inactive ( k cat < 0.03 s -1 ) but they retained micromole level K m for APAO. SMOX did not metabolize any of the tested compounds ( k cat < 0.05 s -1 ) that acted as non-competitive inhibitors having K i ≥ 155 µM for SMOX. In addition, we tested (R , R) -1,12-bis-methylspermine (2,13-diamino-5,10-diazatetradecane) (R , R)- (Me 2 Spm) and (S,S) -Me 2 Spm as substrates for Fms1. Fms1 preferred (S,S) - to (R,R) -diastereoisomer, but with notably lower k cat in comparison with spermine. Interestingly, Fms1 was prone to aldehyde supplementation in its regioselectivity, i.e. the cleavage site of spermidine. Thus, aldehyde supplementation to generate aldimines or N -terminal substituents in polyamines, i.e. attachment of guide molecule, generates novel ligands with altered charge distribution changing the binding and catalytic properties with polyamine oxidases. This provides means for exploiting hidden capabilities of polyamine oxidases for controlling their regioselectivity and stereospecificity., (© 2018 The Author(s).)