The problems of reliability of the process control system are considered. The probability characteristics of various failures are analyzed. A mathematical model of the service system (SO) is described. The offered mathematical apparatus will allow us to work out the valid requirements on reliability, to determine the best operation regime, to choose the control system of SO serviceability, etc.

Keywords: service system, process control systems, reliability, queueing, failure, recovery.

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The time-probability characterization of job processing by a service organ is presented. Several models are considered and the method of their analysis is presented. The obtained results will allow us to work out the valid requirements on reliability and to estimate them in accordance with the specified regime of the equipment operation and maintenance.

Keywords: service organ, technical systems, probability, reliability, failure.

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A stressed-strained state of a transtropic elastic body in the cylindrical coordinate system is considered. The body is characterized by absence of volume strain. Unlike the pure shift, the components of the considered state depend on all three coordinates r, a , z, and only the s _z component of the stress tensor is equal to zero.

Keywords: sressed-strained state, transtropic elastic body, volume stress, pure shift, stress tensor.

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A strict solution of the problem of diffraction of the plane electromagnetic wave by the antenna array consisting of coaxial waveguide elements with finite length has been obtained. The dependence of passage and reflection coefficients on different parameters of the antenna array are investigated.

Keywords: waveguide, properties, screen, antenna array.

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Here is discussed the model of reliability of a large-scale weak nitric acid production plant subjected to two types of failures: 1) drift (wear-out) failures distributed by the n-order special Erlang law, and detected only in the process of a periodical check or renewal (repair); 2) ramdom failures detected by continuous control at the moment of their occurence. The plant technical utilization factor has been determined.

Keywords: nitric acid production plant, reliability, control, renewal, technical utilization factor.

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The reliability and efficiency characteristics of large-scale plants for production of non-concentrated nitric acid, employed in the former Soviet Union, are analyzed. The comparative estimation of the basic and modified plants is presented. Basing on the statistic data, some causes of the relatively low reliability of some plants are revealed.

Keywords: chemical-engineering system, reliability, efficiency, failures, non-failure operating time.

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The qualitative analysis of aircraft dynamics equations allows us to identify the variety of stationary states with an elementary catastrophe. Deformation of the characteristic polynomial and, using the qualitative characteristics, abrupt changes in the system are investigated within the scope of the catastrophe theory. Catastrophe lines directly affect the flight safety and cause the aircraft stability disturbance and occurence of an unexpected situation during the flight. The aircraft qualitative dynamics will be determined as soon as a catastrophe is identified.

Keywords: flight safety, aircraft, stability, catastrophe theory, controllability.

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Mathematical simulation of cavitation wear, one of the urgent but insufficiently studied problems, is considered. In particular, the cavitation wear of precision parts of agricultural hydraulic machines is investigated. The main factors which significantly affect the cavitation value and the functional relation between them have been established. Basing on the similarity and dimensional theory, the functional relation between the process main factors was converted into the relation of nondimensional complex values, i.e. of similarity criteria. A general criterion equation was derived. That equation represents a scientific base for investigating the cavitation wear of the agricultural hydraulic machines precision parts.

Keywords: precision parts, agricultural hydraulic machines, cavitation wear, mathematical simulation.

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It is shown that the existence of double standards of the International Electrotechnical Commission for marking like terminals of transformer windings leads to a double reference system of electromagnetic phenomena, inadequate mathematical models and vector diagrams. Adequate mathematical models have been developed in the unified space-time reference system as unambiguous relations between current, voltage, e.m.f., resistance, inductance and mutual inductance values on the basis of the theory of linear electric circuits. Unambiguous logic definitions of the essence of the sign of the mutual inductance and the like terminals are proposed with consideration of the Lenz law of electromagnetic inertia. Adequate transformer diagrams, where time and topographical voltage, current and e.m.f.diagrams are combined, have been constructed. The work is meant for submission to the International Electrotechnical Commission as a technically orienting document.

Keywords: transformer, vector diagram, like terminals, mutual inductance, mathematical model.

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It is shown that in literature, including the National and International Standards, while analyzing the inductively coupled circuits, the energy conservation law is not depicted unambiguously. The mathematical models of transformer have no physical meaning and it is impossible to solve them precisely as unambiguous ones. Arbitrary selection of the direction of induced currents equals to negation of the Lenz inertia law and is not allowed. The unambiguous mathematical model of a three-phase transformer has been drawn up and the method of its construction has been developed on the basis of the Ampere’s (corkscrew) rule and the Lenz energy conservation law in the integral reference system of circuits and their surface orientations. The geometry of an electromagnetic field determined by the model at any moment of time was fixed as unambiguous in Ampere orientations towards one-poled clamps. The calculation formulae of mutual inductances were derived. The work is meant for submission to the International Electrotechnical Comission (IEC) for consideration as a document of technical orientation.

Keywords: three-phase transformer, mathematical model, inductance.

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A new method of interval-marker access to computer control networks, that will allow to eliminate some drawbacks inherent in the known methods of connection to the common channel, is offered. It is proposed to employ the method of time intervals distribution for transmission of control signals. Analytical relations between the average time of message package delay and the coefficient of transmission medium loading are presented.

Keywords: control networks, enterprise, access method, modification.

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The transition probability of the symbols due to the jitter effect in digital communication systems is determined. The minimum jitter level for different single pulses have been calculated. The distribution law of the minimum jitter level in the case when the additive noise effect takes place in the system has been determined.

Keywords: communication systems, jitter effect, decoding, error.

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The problem of increasing the capacity of the air lift, that conveys the three-component mixture by pulsatory feeding of the gas component, is considered. The empiric dependences for determining the Strouhal number and the hydraulic resistance at pulsatory feeding of the gas component are presented.

Keywords: air lifting, pulsatory flow, shell regime.

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An attempt is made to describe the so-called “medical knowledge” basing on the theory of inexplicit estimations . In particular, description of risk factors and symptoms by the function of accessories is offered. Using this function, it has become possible to present qualitative estimations of the mentioned factors in linguistic terms. The procedure of application of this approach is offered.

Keywords: medical knowledge, theory of inexplicit multiciplities, function of accessories, risk factors, estimation.

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The automated system LEUKOS is designed for diagnosis in the field of myelic and lymphatic nosology as a “doctor’s adviser”. It is envisaged that, in the process of system designing, methodological aspects and peculiarities of mutually agreed activities of a doctor (an expert) and a cognitologist (a system designer) will be taken into consideration. In this process, the significant role of the expert and the cognitologist is emphasized. In the LEUKOS system, mathematical apparatus of the theory of inexplicit estimations by L.Zadeh is employed. Derivation of the results is based on the generalized rule “modus ponens” which is procedurally described in the present work. Some diagnostic problems were formulated and were solved, and clinical tests have begun with the aim to correct the general ideology and the tasks of designing the LEUKOS system.

Keywords: medical diagnostic system LEUKOS, expert, cognitologist, inexplicit estimation method.

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A multi-channel copmuter system for measuring the forces developing in human joints while free motion has been developed. The system is controlled by a specially composed program. The analysis of the lower extremity joints motion consists in matching up the averaged diagrams with the joint motion dynamics. Joint motion delay, maximium speed values at different phases, motion phase shifts between the extremities and various sections of the joints, dispersion and variation coefficients step by step are determined differentially. By these parameters, the influence of motion speed, load and tiredness, the degree of locomotive system distrubances and the treatment effectiveness are estimated.

Keywords: human locomotion, joints, program monitoring, estimation.

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Device for measuring the pain sensitivity threshold (PST) has been developed. The apparatus registers the "TAIL-FLICK" reaction of rats and is used for studying the mechanisms of action of a nociceptive system. The PST consists of the following main units: the unit for indication and control and the unit for information collection. The experimental data obtained by this apparatus are characterized by high accuracy and reproducibility. Data transfer to the computer during the experiment and their location in the electronic sheet Excel considerably reduce the measurement data processing time.

Keywords: pain sansitivity of animals, threshold, measuring device.

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A method of automated on-line analysis of flight information is proposed. The method (unlike the rapid analysis method) is designed for output of the information on a normally running flight in order to report about approaching a fault and to prevent it. The results of the on-line analysis are presented in the flight path control form (the table is given) where the physical values of flight parameters, the flight optimum values and the optimum range of parameter chainging are written down.

Keywords: flight information, on-line analysis, fault prevention.

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The problem of periodic analysis of flight information for revealing the changes in piloting and the automated procedure of its solution are described. The analysis is based on comparing the statistic characteristics of dimensionless deviations from the rational flight path. Accumulation of the information on separate flights and its periodic analysis allow us to reveal the tendencies in the crew's work and to predict the functional efficiency.

Keywords: aircraft, flight information, periodic analysis.

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It is stated that DNA creeping out of the phage head can be considered as a relatively simple physical process, conducted by the difference in medium conditions inside and outside the phage and not by some highly specific “device” and not accompanied by thermal effects associated with destruction of the capsid or other structure elements. Considering the process of DNA reptation from the phage particle from the above point of view, we will obtain: the phage destruction under the temperature effect is a similar phase transition of the 2nd type. This conclusion follows from our pycnometric, calorimetric, and viscosimetric experiments. The partial thermal capacity increment at DNA creeping out of the Un phage (a new phage, morphologically similar to T-even phages) head was calculated and was equal to 1.3J/gЧ K.

Keywords: phage, thermodynamics, phage transition, phage destruction.

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The results of investigation of changes in the Un phage (a new phage, morphologically similar to the T-even phages) partial volume under thermal destruction are presented. It was established that, in this case, the significant, abrupt increase (3 times) in the partial volume of the phage takes place.

Keywords: phage, temperature, partial volume, density.

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High-purity C-phycocyanin (C-PC) preparations have been extracted from the cells of blue-green alga Spirulina platensis. For estimation of the purity degree, the spectrophotometric and electrophoretic methods were used. There was studied the influence of different ion metals on spectral characteristics of C-PC. It is shown that Hg²⁺ ions shift the absorbtion and fluorescence peaks.

Keywords: C-phycocyanin (C-PC), Spirulina platensis, ion metals, Hg², Cu²⁺ , absorbtion and fluorescence spectra.

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The energetical and electronic characteristics of the Claisen rearrangement of phenol-O-allylether were calculated by the semiempirical quantum-chemical method AM1. It is shown that this process consists of two stages: heterolytic breaking of the ether bond and formation of the products of ortho- and para-rearrangements.

Keywords: Claisen rearrangement, phenol-O-allylether, quantum-chemical method.

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By semiempirical quantum-chemical method AM1, the values of the enthalpy (D H), the ionization potential (I), the dipole moment (m ) and the atomic charge (q_i) were calculated. It is shown that, between these electronic indexes and the Hammet’s constants of the substitute (s ), the satisfactory correlation and, between the charge of the nitrogen atom (q_N) and the experimental data of basicity (рКa ), the fime correlation take place.

Keywords: pyridine derivatives, quantum-chemical method, Hammet’s constants, basicity.

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A new bis-indole system – bis(5-indolyl)sulphide was synthesized from ethylpyruvate 4,4ў -diphenylthiodihydrazone. By quantum-chemical calculations of bis(5 indolyl)sulphide, it is shown that the position at a pyrrole ring is preferable for starting the electrofilic attack. The Vilsmeier and Mannich reactions for 2,2ў -diethoxycarbonyl- bis(5-indolyl)sulphide are sudied.

Keywords: indole, sulphide, cyclization, Japp-Kligeman reaction, Mannich reaction, Vilsmeier reaction.

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The halogen-containing aminophenylindoles were synthesized. Their acetylaminoderivatives, compounds of potential antitumor activity, were separated and identified.

Keywords: phenylindole, hydrazone, cyclization.

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Under the action of lead hydroxide 2,6-di-O-p-toluenesulphonyl and 2,6-di-O-methanesulphonyl-D-glucopyranoses have been converted into 2-deoxy-D-gluconic acid. The corresponding derivatives of this acid have also been obtained.

Keywords: acid conversion, 2-deoxy-D-gluconic acid.

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Ammoniate complexes of d-metals tetrathioantimoniates with the general formula [M(NH₃)n]₃(SbS₄)₂ were synthesized. The composition and the structure of the synthesized compounds were studied by chemical and X-ray-phase analyses, and IR spectroscopy.

Keywords: tetrathioantimoniate, ammoniate complexes.

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The synthesis of 3,7-dimethyl-2,7-octadiene-1-yl propionate, the pheromone of Diaspidiotus perniciosus Comst., was carried out in two steps on the base of geraniol, the plant component of essential oil. Ethyl chrysantheate was synthesized by standard methods and then underwent reesterification with geraniol. The produced chrysantheate possesses potential pyrethroidic properties.

Keywords: biologically active compounds, geraniol, pheromone, pyrethroidic compounds, synthesis.

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A possibility of application of natural zeolites of a sedimentation origin, namely, clinoptilolite-, mordenite- and diatomite-containing rocks of industrial deposits of Georgia for production of a silicon-containing material to be further used as a solid support is considered. The rocks, after their alkali-acid treatment, were calcined at 1000⁰C for 8 hours. The obtained solid mass, enriched with silica and practically free of oxides of R₂O₃ type, was used as a solid support for preparation of surface-layer adsorbents with zeolite of NaX-type as an active agent. Chromatographic investigations were carried out on two model mixtures: 1) ethane-propane-butane and 2)pentane-hexane-heptane. It was established that the mordenite-based and diatomite-based solid supports and the solid support Chromatoh N-AW are close to each other in their chromatographic properties.

Keywords: solid support, surface-layer sorbent, natural zeolites.

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The process of gas-chromatographic separation of methylpyridine isomers on the new mesoporous adsorbent type M41S and its form modified by tallium salts is studied. The modification of the mesoporous adsorbent with the tallium cation, unlike the unmodified form of this adsorbent, provides for the separation of all methylpyridine isomers.

Keywords: mesoporous adsorbent, chromatography, picoline, application.

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To simplify the process of granulation and capsulification of grain, for producing the multicomponent granular and capsular polymer compositions, the thiocarbamide-formaldehyde oligomer was used as a matrix. Presence of sulfur in the matrix determines fungicidal properties of the matrix. Simultaneously, the hydrofobic properties and the stability in soil of the oligomer improve.

Keywords: polymer composition, thiocarbamide oligomer, grain granulation, grain capsulification.

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Trimethylsilylation of natural silicates was carried out at a comparatively high temperature (~ 100⁰C) in the autoclave. It was established that, under these conditions, the silicates undergo vigorous conversions, i.e. their decationization and partial decomposition of the skeleton of the silicate anion take place. Trimethylsilylation of the surface of the initial silicate particles also occurs. By silylation of ascangel, the insolube siliconorganic polymer, containing small amounts of metal cations (0,003-1,5%), was obtained. On its basis, the hybrid composition material SiO₂-SiC was produced. Soluble polyorganosiloxanes can be obtained by trimethylsilylation of natural rocks, containing the phases of the lomontite, atrolite and phyllipsite type.

Keywords: trimethylsilylation, natural silicates, natural rocks, silicon-organic polymer.

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Adsorptive desulfurization of a naphthalene fraction of the high-temperature coal coking resin is investigated. It is shown that, when natural clinoptilolite and its decationized form are used as adsorbents, the naphthalene fraction desulfurization proceeds rather efficiently (up to 95-96%). The isolated product satisfies the available standards.

Keywords: naphthalene fraction, high-temperature coking resin, adsorbtive desulfurization.

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The bis-analogue of 2-methyleneindoline base - bis-(1,3,3-trimethyl-2-methyleneindolin-5-yl)sulphone has been synthesized by conversion of bis-(2,3,3-trimethylindolenin-5-yl)sulphone. The fused system incorporating methyleneindoline and indolenine fragments was obtained as a co-product.

Keywords: Fischer base, methyleneindoline, indolenine.

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The reaction of hydrolysis of 1,1-dichloro-1-sila-2-oxadihydrophenanthrene in a neutral medium in the presence of aniline has been investigated and the corresponding dihydroxy-containing product has been recovered. The reaction of catalytic dehydrocondensation of synthesized 1,1-dihydroxy-1-sila-2-oxadihydrophenanthrene with 1,4-bis-(dimethylsilyl)benzene in the presence of powder-like potassium has been investigated and the corresponding well soluble copolymers have been produced. It is shown that, during dehydrocondensation, ring opening processes do not take place. The reaction order, the dehydrocondensation rate constants and the activation energy have been determined.

Keywords: hydrolysis reaction, dehydrocondensation.

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The reaction of heterofunctional condensation of 1,1-dichloro-1-sila-2-oxa-dihydrophenanthrene with dihydroxydiphenylsilane at various ratio of initial compounds in the presence of pyridine has been investigated and a , w - dihydroxysilaoxadihydrophenanthrene-diphenylsiloxane oligomers with various degree of condensation have been obtained. By the reaction of heterofunctional condensation of a , w -dihydroxysilaoxadihydrophenanthrene-diphenylsiloxanes with a , w -dichlorodimethylsiloxanes in the presence of anhydrous amines, organosiloxane block-copolymers with the regular arrangement of silaoxadihydrophenanthrene-diphenylsiloxanes fragments in the main linear dimethylsiloxane chain were obtained. Thermogravimetric, differential scanning calorimetric (DSC), gel-permeation chromatographic (GPC) and wide angle X-ray analyses of the synthesized block-copolymers were carried out. By DSC and X-ray investigation at definite values of the flexible dimethylsiloxane chain length the microgeterogeneous structure of the block-copolymers was observed.

Keywords: organosiloxane block-copolymers, silaoxadihydrophenanthrene fragments, heterofunctional condensation.

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It is shown that, by treating the products of interaction between d-metal salts and 2,2’-dipyridil with a sodium arsenate (V) aqueous solution (without their recovery in an individual state), the corresponding coordination compounds are precipitated. Basing on the IR spectroscopic investigation data, the arsenate ions are presumed to be in the external sphere of the complexes.

Keywords: coordination compounds, synthesis, arsenates, d-metals, 2,2’-dipyridil.

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Coordination compounds of some d-elements (III) tetraoxoarsenates (V) with b -acetylphenylhydrazine were synthesized and investigated. The obtained results allow the conclusion that b -acetylphenylhy-drazine molecules form, with the central atom, common metal-hydrazine five member cycles: the ligand molecule has the function of bidentate ligands bound to the metal central atom via the atom of amine group nitrogen, and via the atom of carbonyl group oxygen.

Keywords: tetraoxoarsenates, coordination compounds, b -acetylphenylhydrazine, complexes.

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The melanoidin formation reaction between o-, m- and p-aminobenzoic acids and sugars (glucose, galactose, arabinose and xylose) is studied. Formation of the melanoidin pigment intensively occurs at low pH and, by increasing of pH, the reaction rate of melanoidin formation decreases: according to their activity, the aminobenzoic acids can be arranged as follows: m>o>p. N-, o-, m-, p- carboxyphenyl D-glucosyl amines have been synthesized.

Keywords: aminobenzoic acids, sugars, melanoidin, N-carboxyphenyl D-glucosyl amines

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The results of investigation of the reaction between trialkylarsenites and butanediol are presented.It is shown that the exchange reaction with formation of arsenous acid cyclic ethers takes place in this case.

Keywords: 1,3-butanediol, symmetric trialkylarsenites, reesterification.

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From the rocket fuel component (samine), a mixture of xylidines was extracted and, on its base, acetylxylidines were synthesized. The dependence of their solubility on the temperature, the pH value and the H₂O₂ concentration is studied. It was established that stabilizing capabilities of the mixture of acetylxylidines and of acetanilide are practically similar. The experiment lasted for 6 months, using the 3.3 – 35.5% H₂O₂ solutions.

Keywords: hydrogen peroxide stabilizer, acetylxylidines, rocket fuel.

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The possibilities of increasing the sodium dithioarsenate (V) yield and its application as an initial material for producing the corresponding d-metal (III) salts are considered. It is shown that the sodium dithioarsenate (V) yield can be grown by 20% by increasing the molar fraction of sodium hydroxide in the reactive mass. It was established that the product of the hydrochemical reaction between some d-metal (III) salts with sodium dithioarsenate (V) is the component of dithioarsenic acid salt.

Keywords: sodium dithioarsenate, d-metal salts, synthesis, cation exchange.

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It is shown that potassium chromate oxidizes arsenic (III) sulfide in an acid medium (HCl, H₂SO₄) with formation of diarsenic pentasulfide and arsenic acid. Main oxidizers of auripigment are chromate ions. The reaction is exotermic: 15As₂S₃+20K₂CrO₄+100HCl® 9As₂S_5Ї +20CrCl₃+40KCl+12H₃AsO₄ +32H₂O.

Keywords: auripigment, potassium chromate, oxidation.

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Arsenic is almost quantitatively educed from realgar(As₄S₄)-auripigment(As₄S₆) ores of Racha, Georgia, by an alkaline solution (NaOH, KOH). The process significantly accelerates if water solutions of the corresponding sulfides (Na₂S, K₂S) instead of alkali are used.

Keywords: realgar-auripigment ores, eduction, arsenic (III) sulfide.

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The possibility of producing arsenic (III) sulfide from the industrial residuals of pyrometallurgical processing of nonferrous and precious metals ores is considered. For this purpose, the samples of industrial residuals of processing the nonferrous and precious ores were treated with amyl, izoamyl and hexyl alcohols. It was established that maximum arsenic is extracted by azeotropic drying. It is shown that the filtrate obtained from the mentioned samples can be used as an initial material for production of arsenic (III) sulfide. The procedure of producing arsenic (III) sulfide is described.

Keywords: arsenic (III) sulfide, nonferrous and precious metals ores, industrial residuals, production.

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Basing on the daily model of the Earth magnetosphere, latitude ozone distribution both by maximums and by latitude values for North and South hemispheres is explained. For the Aurora, the maximum frequencies difference in March and September was established using the mentioned daily model. It is stated that the night magnitosphere near the Earth is determined by the day magnitosphere and the solar wind.

Keywords: atmospheric ozone, magnetosphere of the Earth, daily model, Aurorae.

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It is stated that the Darwin’s law of natural selection and global regular cycling in the evolution of forming all structural levels of the matter, described by the author, coincide in operation at the macromolecular level of living systems just as coincide in operation dynamic and quantum-wave laws at boundary macro-and microlevels of physical and chemical systems.

Keywords: law of natural selection, physical and chemical systems, global regular cycling.

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The favourable and unfavourable zones in Georgian domed churches from the point of veiw of acoustics are determined on the basis of application of geometrical acoustics methods.

Keywords: geometrical acoustics, domed churches, sound-absorbing materials.

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The problems associated with special sound reflectors used in concert halls, theatres, etc. are considered.

Keywords: directed reflection of sound, sound source, reflectors.

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