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The results of experimental investigations of the features of diffusion combustion during the interaction of a round supersonic microjet of air in the center and a coaxial (coflowing ring) jet of hydrogen. Such combustion is accompanied by a number of new phenomena: the formation of a cone-shaped flame near the nozzle сutoff, the locking of the combustion region in this cone, the presence of small-scale supersonic cells in the resulting flow, and the formation of laminar sections and their turbulization.

The link of the chemical composition of the plant with the active volcanism of Kamchatka, is determined by the stable occurrence into the composition of the priority chemical elements for plants, volcanic ashes and soils: Ca, Mg, Mn, P, Cu, Zn and Sr. An elevated geochemical background of Kamchatka plants relative to the bulk chemical composition of the peninsula’s soils was established. The contents of Br, Hg, Hf, Sb, Ga, W, K relative to the clarks for living matter in the plants of the region are exceeded by 3–5 times. Against the background of small variations in the contents of chemical elements in plants of different regions, the relatively rich biogeochemical background of the Western region of the southern province (the western coast of Kamchatka) is determined, where most ancient near-surface volcanic ashes for Kamchatka are transformed into humus-accumulative horizons. On the territory of young volcanic ash fallout in the immediate vicinity of volcanoes, the relative richness of vegetation with chemical elements and the poverty of soils by mobile forms of elements have been established. On the contrary, at a distance from the volcanoes in the zone of far transfer fallout ashes, there is a marked relative poverty of plants and soil richness of available chemical elements.

In this paper, we presented the results of experimental studies of the diffusion combustion of a plain hydrogen microjet flowing from a slit micronozzle at subsonic and supersonic speeds. For the first time, four scenarios of diffusion combustion of a plain hydrogen microjet including supersonic combustion in the presence of supersonic cells in both air and hydrogen are presented. The stabilization of the subsonic combustion of a hydrogen microjet was established to be due to the presence of a «bottleneck flame region» while the stabilization of the supersonic combustion of a microjet was found to be associated with the presence of supersonic cells. The observed hyster­esis of diffusion combustion of a plain hydrogen microjet depends on both the method of igniting the microjet (near or far from the nozzle exit) and the direction of change in the rate of its outflow (growth or reduction).

Volcanic soils of Kamchatka have the low contents of most the chemical elements in relation to their overall prevalence in the soils of continents and volcanic soils of Europe. Relatively increased gross contents of elements typical for volcanic rocks of medium and basic composition: Na, Ca, Mg, Cd, Mn, Co, Cu, and steadily low contents of elements characteristic of acid volcanics: La, Ce, Pr, Nd, Nb, Hf, Tl, Rb and Th, is most characteristic of the soils of different areas of the peninsula. The existing in the past and currently observed different conditions of volcanism in the previously allocated soil areas of Kamchatka determine the diversity of the chemical composition of the soils in these territories.

Common geochemical features of volcanic near-surface ashes of Kamchatka (ashes located under the surface organogenic soil horizons) are their depletion by most chemical elements in comparison with average indicators for volcanic rocks of corresponding composition and relative enrichment of a limited range of elements, mainly typomorphic for main rocks (P, Mg V, Cr, Cu, Zn, Zr, Sb). Against the background of small variations in the contents of chemical elements in the ashes of different areas of the peninsula, the range of their priority elements is determined by their petrochemical composition. The active activity of the Northern group of volcanoes of Kamchatka causes a relatively high content of mobile forms of elements in the near-surface ashes of the Northern province in comparison with the ashes of the southern part of the peninsula.

The possibility of state estimation for a dynamic system with nonlinearities in the equations of dynamics and measurements using the Singular Transformations Method is discussed. The features of the proposed approach application are considered. For a methodological example, the equations for the required estimates are specified and the estimation accuracy analysis is carried out.

The effect addition of inert (He, N2, Ar, CO2) and reacting (СН4, O2, CF3Br, (CH3O)PO) gases in a hydrogen or in coflowing air stream on lift-off diffusion flame conditions of hydrogen micro jet effluxed from the round micro nozzle was experimentally studied. Using the schlieren technique a critical hydrogen flow rate was established at which the flame of the hydrogen microjet detaches from the nozzle when introducing additives of the studied gases into both air and hydrogen. It has been established that the addition of all the studied gases to the hydrogen leads to a decrease in the velocity range of its microjet at which flame stabilization is possible, regardless of whether the gases introduced into hydrogen are inert or reactive. It is shown that in the case of the addition of various gases to the hydrogen, the main factor determining the critical flow rate at flame lift-off from the micro nozzle is the average molecular weight of the H2 gas mixture with additives. At addition of the studied gases into the coflowing air, the critical flow rate of H2 is determined by their affect on the chemical reactions of hydrogen oxidation (inhibition effectiveness), as well as by a decrease in oxygen concentration due to dilution of air by additives. The data obtained are of interest to hydrogen energy in terms of determining the limits of sustainable combustion of the hydrogen microjet, as well as determining the minimum phlegmatizing concentrations of additives of inhibitors and fire suppressant in the air, preventing the ignition and explosion of hydrogen in case of emergency at its leak.

Results of experimental studies of the round hydrogen microjet interaction with a coaxial air for supersonic speed jets efflux are presented in this work. It is shown that interaction of round and coaxial air jets at their supersonic efflux leads to appearance of a train small/large-scale and, on the contrary, large/small-scale supersonic cells on a resultant jet with growth and reduction of speed of its efflux, respectively. It is found that the result of the round and coaxial air jets interaction at their supersonic efflux does not depend on geometrical parameters of a round and coaxial exit nozzle.

Results of experimental studies of features of the round hydrogen microjet combustion in a coaxial air jet are presented in this work. It is shown that the combustion scenario is connected with existence of the «bottleneck flame region». This fact correlates with the similar scenarios of the diffusion hydrogen microjet combustion at subsonic efflux velocity investigated by us earlier. It is revealed that the spherical shape of the “bottleneck flame region” is transformed to a cylindrical shape. It is found that the round hydrogen microjet combustion in a coaxial air jet at supersonic efflux velocity is accompanied by existence of supersonic cells both in a hydrogen microjet and in a wake of coaxial air jet. Round hydrogen microjet supersonic combustion in a coaxial air jet is connected with a flame separation from a nozzle exit.

Results of experimental studies of the round air microjet interaction with a coaxial hydrogen jet at its combustion for supersonic speed jets efflux are presented in this work. It is revealed that combustion of the coaxial hydrogen jet with growth of its speed efflux is accompanied by all scenarios, observed at study of the round and plane hydrogen microjets diffusion combustion. However, “bottleneck flame region” undergoes considerable geometrical deformations because of specifics of a flame of a coaxial jet. It is shown that “bottleneck flame region” is transformed from Y-shaped to spherical shape in the activity of growth of a coaxial jet speed efflux. It is found that a round air microjet interaction with a coaxial hydrogen jet at its combustion is accompanied by several new phenomena: existence of cone-shaped area a coaxial jet combustion near a nozzle exit; existence of small-scale supersonic cells on a resultant flame; absence of the hydrogen combustion efflux from combustion region of a coaxial jet near nozzle exit; flame-out from combustion region of a coaxial jet near nozzle exit that leads to hydrogen ignition downstream, its intensive combustion and sharp acoustic noise occurrence; existence of a turbulent flame, to its separation from a nozzle exit and transition to supersonic combustion of a resultant jet.

Results of the experimental studies of a round hydrogen microjet combustion in a coaxinal jet of air and SiO2 nanopouder mixture efflux from a slot-hole (multinozzle) coaxial nozzle at subsonic and supersonic efflux velocity are presented. It is shown that scenarios of a hydrogen microjet combustion in a coaxinal jet of air and nanopouder mixture are similar to scenarios of diffusion combustion of a hydrogen microjet at subsonic and supersonic efflux velocity. Existence of “bottleneck flame region” is revealed at subsonic and a flame separation from a nozzle exit at supersonic efflux velocity. It is found that with efflux velocity growth of jets it is possible to observe intensification of the luminescence of the flame at the boundary between the jet of hydrogen and air / nanopowder mixture and existence of «bottleneck flame region» as in a laminar coaxial jet and in a flame of a hydrogen microjet combustion. On the other hand, it is possible to observe actually disappearance of the «bottleneck flame region» at approach to transonic efflux velocity.

The article presents qualitative data on the study of the process of diffusion combustion during the outflow of a gas jet from a nozzle apparatus with a certain arrangement of nozzles. The nozzle apparatus is a round nozzle with a straight channel and a coaxially located annular slot. In the experiments, hydrogen or methane was supplied through an annular slot, and the air was supplied through a central circular micro nozzle. The main features of the diffusion combustion of hydrogen and methane during the outflow from the nozzle apparatus are revealed and a qualitative comparison of the processes is carried out. In both cases, at the initial stage, laminar combustion is observed near the nozzle exit and a breakthrough of the flame front occurs with the release of an incombustible mixture of combustible gas and air. At a high flow rate, the flame separates from the nozzle exit. The fundamental difference is that hydrogen exhibits significantly better combustion stabilization characteristics at the nozzle exit.

The geochemical features of volcanic soils (Andosols) in the northern soil province of Kamchatka are identified. The background regional concentrations (Cbr) of most of chemical elements in the studied soils are lower than their average concentrations in soils of the world and in the European volcanic soils. Only Na, Ca, and Mg are present in elevated concentrations in all the studied soils in the north of Kamchatka. Regional background concentrations of elements are exceeded by 1.6 times in the area of active ashfalls of the Tolbachik volcano and by 1.3 times in the area of active ashfalls of the Shiveluch volcano. The concentrations of mobile forms of elements in these areas exceed their regional background concentrations by 2.1 and 2.6 times, respectively.

The paper gives an overview of federated filtering methods used in navigation data processing. The principles of designing federated filters are considered and their man properties are discussed.

The article is in honor of the 80th birthday of Leonid P. Nesenyuk (1940–2009), Doctor of Technical Sciences, Professor, the Winner of the Russian Government Prize, Laureate of the N.N. Ostryakov Prize, the scientist who has made a significant contribution to the development of modern gyroscopy.

Automated measuring complex (AMC-2) for the spatial – temporal hot – wire anemometric visualization of jet flow field is designed and fabricated. Coordinate device and unit of the measurement, collecting, storage and processing of hot – wire anemometric information were integrated in the AMC-2. Coordinate device is intended for precision movement of the hot – wire probe in jet flow field according to the computer program. At the same time accuracy of the hot – wire probe movement is 5 microns on all three coordinates (x, y, z). Unit of measurement, collecting, storage and processing of hot –wire anemometric information is intended for the hot – wire anemometric measurement of the jet flow field parameters (registration of the mean - U and fluctuation – u’ characteristics of jet flow velocity), their accumulation and preservation in the computer memory. In general, after processing of the measurement results according to certain programs, AMC-2 allows to present both qualitative, and quantitative results of the jet low field study in the form of spatial patterns and video clips of the space-time hot – wire anemometric visualization.

Experimental data on the diffusion combustion of round hydrogen microjet in concurrent coaxial flows are presented. The effects on combustion of the concurrent flow of air and that of air premixed with nanopowder of TiO2 are of interest. The hydrogen microjet is emanated from a round micronozzle which is surrounded by a coaxial slit to produce the concurrent flow. Combustion events found in the present conditions are similar to those observed in the previous studies on diffusion combustion of hydrogen microjets at subsonic and supersonic velocities. In a subsonic range, the so-called “bottleneck-flame region” is generated close to the nozzle exit, while in high-speed conditions the flame separates from the nozzle. At increasing velocity of both the hydrogen microjet and the concurrent flow, the “bottleneck-flame region” is still found and the combustion becomes more intense. The “bottleneck-flame region” is suppressed at the microjet velocity approaching transonic values.

Experimental data on combustion of a round hydrogen microjet in a cocurrent coaxial air jet are presented. As is found, the combustion of microjet is dominated by the generation of “bottleneck-flame region” that is in agreement with our previous observations on the diffusion combustion of subsonic hydrogen microjets. Transformation of the spherical “bottleneck-flame region” to a cylindrical one is observed. At supersonic combustion of the round hydrogen microjet, supersonic cells are generated both in the microjet and in the cocurrent coaxial air flow. A feature of the combustion process is the flame lift-off from the nozzle exit.

In the present paper we show our recent experimental data on diffusion combustion of a round hydrogen microjet in a cocurrent flow of air mixed with nanoparticles of TiO2. The hydrogen microjet is emanated from a round micronozzle which is surrounded by a coaxial slit to produce the cocurrent flow. Combustion events found in the present conditions are similar to those observed in the previous studies on diffusion combustion of hydrogen microjets at subsonic and supersonic velocities. In a subsonic range, the so-called “bottleneck-flame region” is generated close to the nozzle exit, while in high-speed conditions the flame separates from the nozzle. At increasing velocity of both the hydrogen microjet and the cocurrent flow, the “bottleneck-flame region” is still found and the combustion becomes more intense. The “bottleneck-flame region” is suppressed at the microjet velocity approaching transonic values.

Under conditions of active volcanism, the soils on different geomorphic positions (from high-mountain landscapes to river valleys) are formed under the impact of periodic ashfalls. The exogenous processes affect the redistribution of volcanic ashes by the elements of the relief, so that the soils of different altitudinal zones have their own morphological specificity. It is suggested that two additional types of volcanic soils should be included in the new Russian soil classification: the type of alluvial volcanic soils in the order of volcanic soils and the type of volcanic lithozems in the order of lithozems. These soils can be considered intergrades between volcanic and alluvial soils and between volcanic soils and lithozems, respectively.

The microelemental composition of volcanic soils of Kamchatka is specified by the composition of the volcanic ashes from which these soils are developed. It is found that the soils developing from acid and intermediate ashes are characterized by low contents of most of the studied microelements as compared with their clarke values in soils of the world. The background concentrations of microelements in the soils developed from intermediate ashes of Kamchatka are higher than those in the soils developed from acid pyroclastic deposits. Differences in the microelemental composition of the soils developed from different ashes are seen against the regional background specificity of the volcanic soils of Kamchatka. These soils are enriched in the elements typical of mafic magnetic rocks. In particular, this concerns Cu, Mn, Sc, V, and Ag; the concentrations of these elements in the soils of Kamchatka are higher than their average concentrations in soils of the world. This is related to the common geochemical properties of volcanic ashes in Kamchatka, whose composition reflects the geochemical specificity of the multistage volcanism on this peninsula.

On the basis of the Yohkoh data on the site and mechanism of magnetic energy transformation into thermal and kinetic energies of superhot plasmas and accelerated particles, a model is developed that explains observed properties of collisionless 3D reconnection in active regions. The model makes intelligible the observed relation between the S-like morphology and eruptive activity.

Experimental data concerning the in§uence of initial conditions at the nozzle exit on the structure and development characteristics of round jets are reported. Features in the development of laminar and turbu- lent round jets emanating from variously elongated nozzles at identical Reynolds numbers are revealed. Smoke visualization pictures obtained for jets formed under dierent initial conditions (with dierent distri- butions of mean and §uctuating §ow velocities at the nozzle exit) are discussed. It is shown possible to make the zone of laminar §ow in the jet stream more extended and to delay the jet turbulization process in space by making the §ow-velocity pro|le more parabolic at the exit of elongatednozzle. Featuresinthedevelopmentofvorticalstructuresina jet under anacousticactionareidenti|ed. It isshownthat, fora turbu- lent round jet to be produced right at the nozzle exit, the nozzle length must be increasedin excessofa certainvalue so thatto providefor spa- tial growth of turbulent boundary layer thickness, |nally ending in the formation of a fully turbulent §ow velocity pro|le across the channel.

The effect of humid atmosphere (59 and 86%) on phase composition and properties of YBa2Cu3O7−y powder and ceramics prepared by hot pressing has been studied. It has been found that with increase of water content in the powder to 1·6 mass.% the superconducting properties of the corresponding ceramics gradually improve; on further increase of the water content the ceramics degrade resulting in a complete loss of superconductivity. The observed phenomenon can be explained by a plastifying effect of water on the powder by hot pressing on the one hand and by a solid-phase reaction of the products of decomposition (1-2-3) at a high temperature annealing, on the other.

Effect of water vapour on the YBa2Cu3O7−x ceramics of different density has been studied using Auger electron and X-ray photoelectron spectroscopy. The initial period of decomposition of this compound when exposed to H2O is accompanied by Ba(OH)2 deposition on the ceramic grain surface and partial reduction of copper to Cu2O in the oxide. With this barium diffuses to free surfaces of ceramic grains. Degradation of HTSC ceramics proceeds by increase of thickness of the changed layer on free surfaces of grains. Violation of the initial composition may at first lead to some improvement of transitional characteristicsT c and ΔT c and with their subsequent degradation, the transition width ΔT c is in particular broadened. Dense ceramics possess higher resistance to a humid atmosphere.

An improved method for hot pressing of high temperature superconducting (HTSC) powders prepared by conventional solid phase synthesis of the initial BaCO3, CuO and Ln2O3 allows one to obtain HTSC targets and magnetic shields possessing a high degree of homogeneity. By sputtering such targets HTSC films with critical current density of 3.3·106 A/cm2 have been deposited. Shields, prepared according to this method, show a shielding coefficient of 105 andHc of 79 Oe in the constant magnetic field and in the alternating magnetic field the amplitude is 90 Oe in the frequency range of 70–3000 Hz.

A complex study of magnetization change, optical Faraday effect, and light absorption spectrum has been carried out on uniaxial antiferromagnetic crystals of MnF 2 of FeCO 3 under the phase transitions induced by strong external magnetic field. The measurements were made at 4.2 and 20.4 K, which is lower than Neel temperature (T n =68 and 38 K for MnF 2 and FeCO 3 , respectively). The field used was pulsed up to 400 kOe. MnF 2 : The magnetic properties have been studied in detail employing a pickup coil method in a narrow range of magnetic fields near the spin-flopping field (H c =92 kOe) with a strict field orientation along the tetragonal axis of the crystal symmetry. The angular field deviation ψ from the c 4 axis is controlled to within 1.5'. In the narrow range of angles ψ c depends on the sample form and the magnetization process is of a jump-like character. The measurements of the longitudinal (along the magnetic field) and transversal susceptibility components made using three pickup coils of mutually perpendicular axes and three coaxial coils shifted along the sample axis show that at ψ c ± 200 Oe the sample magnetically cleaves into interchanging layers of 10-5cm 3 volume which stretch along the symmetry axis of the sample and differ from each other by a longitudinal component of the magnetization vector.