The development of digital models of the soil cover in the western part of Bol’shezemel’skaya tundra

The methods of digital mapping are promising for creating soil maps on difficultly accessible territories. This study was aimed at searching of optimal approaches for digital mapping of the soil cover in poorly studied western part of the Bol’shezemel’skaya tundra on different scales. Medium-scale (1 : 200 000) and small-scale (1 : 1 M) soil maps served as the source of initial information about soils of this region; actual information of the state of the territory was obtained from remote sensing data (Landsat 8 scenes, Aug. 14, 2013) and digital elevation model ASTER GDEM v.2. After extraction of information and the choice of predictors, the analysis of digital soil cover models obtained with the use of different algorithms – Random Forest (RF), Multinomial Logistic Regression (MLR) and Linear Discriminant Analysis (LDA) – was performed. The coefficient of agreement between the newly developed digital models and the initial paper-based soil maps (kappa) was calculated. This test demonstrated that the RF algorithm ensures the best results, so the final digital maps were obtained using it. Averaged kappa values for the compared small- and medium-scale models were as follows: RF – 0.39 and 0.36; MLR – 0.31 and 0.31; and LDA – 0.28 and 0.18, respectively. After the preliminary correction of the initial medium-scale map, the kappa values somewhat increased (RF – 0.39, MLR – 0.35, LDA – 0.30). At the stage of evaluation of digital soil maps obtained with the use of RF algorithm, these maps and the initial soil maps were compared with independent point-size terrain data. The degree of agreement between these data and the new digital soil maps proved to be no less than that for the initial maps. For the initial and digital small-scale maps, it reached 24 and 26 %, respectively; for the initial and digital medium-scale maps, 54 and 43 %, respectively. After the preliminary correction of the initial medium-scale map, the degree of agreement between the digital model and terrain data improved considerably and reached 61 %. This method of digital soil mapping on the basis of analogous data seems to be optimal

Synthesis and Processing of MgB2MgB_2 powders and wires

Sintered powders and wires of superconducting $MgB_2$ have been fabricated under a variety of conditions in order to determine details of the diffusion of the $Mg$ into $B$ and to study the types of defects that arise during growth. For samples prepared by exposure of boron to $Mg$ vapor at $950^{\circ}C$, the conversion of particles of less than $100\mu m$ size particles to $MgB_2$ is complete in about $2 h$. The lattice parameters of the $MgB_2$ phase determined from X-ray are independent of the starting stoichiometry and the time of reaction. Wire segments of $MgB_2$ with very little porosity have been produced by reacting $141 \mu m$ diameter boron fibers in an atmosphere of excess $Mg$ vapor at $950^{\circ}C$. Defects in the reacted fibers are predominantly the voids left as the boron is converted to $MgB_2$

Synthesis and Stoichiometry of MgB2

The system MgxB2 has been investigated to investigate possible nonstoichiometry in MgB2. When synthesized at 850oC, MgB2 is a line compound with a possible Mg vacancy content of about 1%. Small changes in lattice constants as a function of starting composition result from grain interaction stresses, whose character is different in the Mg-rich, near-stoichiometric, and Mg-deficient regimes. A small linear decrease of the superconducting transition temperature, Tc, in the Mg-rich regime results from accidental impurity doping.Comment: Accepted for publication in Physica C. 24 pages, 7 figure

Experience in training nurses in intensive care skills for patients with new coronavirus infection

Almost 80% of the average medical staff of TsGKB No. 6 of Yekaterinburg believe that internship or practical training is necessary to obtain new skills. 56% noted that periodic training is required, which is rare in professional activities. In addition, training in a medical organization is appropriate and allows us to adapt the content and timing of training to the existing needs of the medical institution. The optimal solution for the continuous professional development of employees is the creation of educational and practical rooms or centers on the basis of a medical organization.Почти 80% среднего медицинского персонала ЦГКБ № 6 г. Екатеринбурга считают, что для получения новых умений и навыков необходима стажировка или практические занятия. 56% отметили, что требуется периодическая отработка навыков, которые в профессиональной деятельности встречаются редко. Кроме того, обучение в медицинской организации является целесообразным и позволяет приспособить содержание и сроки обучения к имеющимся потребностям лечебного учреждения. Оптимальным решением для непрерывного профессионального развития сотрудников является создание учебно-практических кабинетов или центров на базе медицинской организаци

Electronic and structural properties of superconducting MgB2_2, CaSi2_2 and related compounds

We report a detailed study of the electronic and structural properties of the 39K superconductor \mgbtwo and of several related systems of the same family, namely \mgalbtwo, \bebtwo, \casitwo and \cabesi. Our calculations, which include zone-center phonon frequencies and transport properties, are performed within the local density approximation to the density functional theory, using the full-potential linearized augmented plane wave (FLAPW) and the norm-conserving pseudopotential methods. Our results indicate essentially three-dimensional properties for these compounds; however, strongly two-dimensional $\sigma$-bonding bands contribute significantly at the Fermi level. Similarities and differences between \mgbtwo and \bebtwo (whose superconducting properties have not been yet investigated) are analyzed in detail. Our calculations for \mgalbtwo show that metal substitution cannot be fully described in a rigid band model. \casitwo is studied as a function of pressure, and Be substitution in the Si planes leads to a stable compound similar in many aspects to diborides.Comment: Revised version, Phys.Rev.B in pres

First-principle solubilities of alkali and alkaline earth metals in Mg-B alloys

By devising a novel framework, we present a comprehensive theoretical study of solubilities of alkali (Li, Na, K, Rb, Cs) and alkaline earth (Be, Ca, Sr, Ba) metals in the he boron-rich Mg-B system. The study is based on first-principle calculations of solutes formation energies in MgB$_2$, MgB$_4$, MgB$_7$ alloys and subsequent statistical-thermodynamical evaluation of solubilities. The advantage of the approach consists in considering all the known phase boundaries in the ternary phase diagram. Substitutional Na, Ca, and Li demonstrate the largest solubilities, and Na has the highest (0.5-1 % in MgB$_7$ at $T=650-1000$ K). All the considered interstitials have negligible solubilities. The solubility of Be in MgB$_7$ can not be determined because the corresponding low-solubility formation energy is negative indicating the existence of an unknown ternary ground state. We have performed a high-throughput search of ground states in binary Mg-B, Mg-$A$, and B-$A$ systems, and we construct the ternary phase diagrams of Mg-B-$A$ alloys based on the stable binary phases. Despite its high temperature observations, we find that Sr$_{9}$Mg$_{38}$ is not a low-temperature equilibrium structure. We also determine two new possible ground states CaB$_{4}$ and RbB$_{4}$, not yet observed experimentally.Comment: 5 figure

Implementation of correlative enhanced scattering diagnostics of small scale plasma turbulence at the FT-2 tokamak

In this paper the first results of implementation of CES diagnostics at the FT-2 tokamak possessing much more developed set of standard tokamak diagnostics are presented

Poloidal inhomogeneity of the particle fluctuation induced fluxes near of the LCFS at lower hybrid heating and improved confinement transition at the FT-2 tokamak

This paper deals with the new spectral and microturbulence experimental data and their analysis, which show, that the radial electric field Er generated at the LH heating (LHH) in the FT-2 is high enough to form the transport barriers. The ETB is formed when LHH is switched off. The radial fluctuation-induced EB drift flux densities near LCFS in SOL are measured at two different poloidal angles. For this purpose two Langmuir probes located at low and high field sides of the torus are used. Registration of the poloidal and radial components of the electric field and density fluctuations at the same time during one discharge permits to measure the poloidal asymmetry of the transport reduction mechanism of the radial and poloidal particle fluxes in the SOL. The absolute E(~) fluctuation levels show dependence on the sign of Er shear. The modification of the microscale turbulence by the poloidal Er x B rotation shear EB at the L - H transition near LCFS is also studied by X-mode fluctuation Reflectometry. The new data were obtained by spatial spectroscopic technique.Comment: 12th International Congress on Plasma Physics, 25-29 October 2004, Nice (France