Strategic analysis of environmental and economic potential of Norilsk metallurgical cluster

Strategic significance of Krasnoyarsk territory as well as Arctic Norilsk metallurgical cluster cannot be in contradiction with social sustainability of the region, what is especially important in the context of serious environmental pollution of the addressed constituent entity of the Russian Federation.Thus, the issue on the building a system of strategic analysis and management of environmental-economic potential of Arctic Norilsk metallurgical cluster (ANMC) remains relevant. In preparation of the article we used the methods of systems analysis and synthesis of available information related to the research. Building on existing economic theories, a model of the conception under consideration was introduced, the term 'system of strategic analysis and management of environmental-economic potential of ANMC' was defined and briefly characterized.The results obtained can be used as a methodological framework for the development of strategic documents on several levels: corporate, regional as well as used by the executive bodies for the purpose of justification of the directions chosen for improving socio-environmental-economic sustainability of Krasnoyarsk territory. © 2020 The Authors, published by EDP Sciences

Electromechanical Imaging of Biological Systems with Sub-10 nm Resolution

Electromechanical imaging of tooth dentin and enamel has been performed with sub-10 nm resolution using piezoresponse force microscopy. Characteristic piezoelectric domain size and local protein fiber ordering in dentin have been determined. The shape of a single collagen fibril in enamel is visualized in real space and local hysteresis loops are measured. Because of the ubiquitous presence of piezoelectricity in biological systems, this approach is expected to find broad application in high-resolution studies of a wide range of biomaterials.Comment: 12 pages, 4 figures, submitted for publication in Appl. Phys. Let

Quantized Rotation of Atoms From Photons with Orbital Angular Momentum

We demonstrate the coherent transfer of the orbital angular momentum of a photon to an atom in quantized units of hbar, using a 2-photon stimulated Raman process with Laguerre-Gaussian beams to generate an atomic vortex state in a Bose-Einstein condensate of sodium atoms. We show that the process is coherent by creating superpositions of different vortex states, where the relative phase between the states is determined by the relative phases of the optical fields. Furthermore, we create vortices of charge 2 by transferring to each atom the orbital angular momentum of two photons.Comment: New version, 4 pages and 3 figures, accepted for publication in Physical Review Letter

Character of jet flows in mass-spectrometric interfaces at various pressures and chamber lengths

Samples-in particular, of bioorganic matter—are usually introduced into a mass spectrometer from atmosphere to high vacuum via a gasdynamic interface that represents a chamber with intermediate pressure or a system of chambers with gradually decreasing pressure. Transformation of the character of an expanding jet flow in a single-chamber interface has been studied as dependent on the chamber length and pressure. Knowledge of this character allows the system parameters to be most effectively used so as to ensure high ion transmission and decrease mass discriminatio

Spin-to-Orbital Angular Momentum Conversion in Semiconductor Microcavities

We experimentally demonstrate a technique for the generation of optical beams carrying orbital angular momentum using a planar semiconductor microcavity. Despite being isotropic systems, the transverse electric - transverse magnetic (TE-TM) polarization splitting featured by semiconductor microcavities allows for the conversion of the circular polarization of an incoming laser beam into the orbital angular momentum of the transmitted light field. The process implies the formation of topological entities, a pair of optical half-vortices, in the intracavity field

Spin-polarized tunneling spectroscopic studies of the intrinsic heterogeneity and pseudogap phenomena in colossal magnetoresistive manganite La_{0.7}Ca_{0.3}MnO_{3}

Spatially resolved tunneling spectroscopic studies of colossal magnetoresistive (CMR) manganite $\rm La_{0.7}Ca_{0.3}MnO_3$ (LCMO) epitaxial films on $\rm (LaAlO_3)_{0.3}(Sr_2AlTaO_6)_{0.7}$ substrate are investigated as functions of temperature, magnetic field and spin polarization by means of scanning tunneling spectroscopy. Systematic surveys of the tunneling spectra taken with Pt/Ir tips reveal spatial variations on the length scale of a few hundred nanometers in the ferromagnetic state, which may be attributed to the intrinsic heterogeneity of the manganites due to their tendency towards phase separation. The electronic heterogeneity is found to decrease either with increasing field at low temperatures or at temperatures above all magnetic ordering temperatures. On the other hand, spectra taken with Cr-coated tips are consistent with convoluted electronic properties of both LCMO and Cr. In particular, for temperatures below the magnetic ordering temperatures of both Cr and LCMO, the magnetic-field dependent tunneling spectra may be quantitatively explained by the scenario of spin-polarized tunneling in a spin-valve configuration. Moreover, a low-energy insulating energy gap $\sim 0.6$ eV commonly found in the tunneling conductance spectra of bulk metallic LCMO at $T \to 0$ may be attributed to a surface ferromagnetic insulating (FI) phase, as evidenced by its spin filtering effect at low temperatures and vanishing gap value above the Curie temperature. Additionally, temperature independent pseudogap (PG) phenomena existing primarily along the boundaries of magnetic domains are observed in the zero-field tunneling spectra. The PG becomes strongly suppressed by applied magnetic fields at low temperatures when the tunneling spectra of LCMO become highly homogeneous. These findings suggest that the occurrence PG is associated with the electronic heterogeneity of the manganites.Comment: 15 pages, 15 figures. Published in Physical Review B. Corresponding author: Nai-Chang Yeh (E-mail: [email protected]

Peculiarities of strained state of the buggy undercarriage under torsional loading

This paper deals with the traits of strained state of buggy undercarriage torsional loading. The buggy undercarriage represents a tubular space frame consisting of round cross-section elements. The strained state of the buggy space frame can be characterized by a number of specific features such as: a centerline distortion and front sub-frame cross-sections twisting about their own pivot points. The possible reasons for it are considered as well as their negative effects. Practical recommendations to minimize the negative effects are proposed. All the represented results are obtained with the help of a computer simulation technique based on the finite element method. © 2019 Published under licence by IOP Publishing Ltd

Discontinuous Bifurcations under 2-DOF Vibroimpact System Moving

Dynamic behaviour of strongly nonlinear non-smooth discontinuous vibroimpact system isstudied. Under variation of system parameters we find the disconti nuousbi furcati onsthat are the dangerousones. It is phenomenon unique to non-smooth systems with discontinuous right-hand side. We investigate the 2-DOF vibroimpact system by numerical parameter continuation method in conjunction with shooting and Newton-Raphson methods, Wife simulate the impact by nonlinear contact interactive force according to Hertz's contact law. We find the discontinuous bifurcations by Floquet multipliers values. At such points set-valued Floquet multipliers cross the unit circle by jump that istheir moduli becoming more than unit by jump. Wealso learn the bifurcation picture change when the impact between system bodi es became the soft one due the change of system parameters, This paper is the continuation of the previous works

Infrared studies of a La_(0.67)Ca_(0.33)MnO_3 single crystal: Optical magnetoconductivity in a half-metallic ferromagnet

The infrared reflectivity of a La_(0.67)Ca_(0.33)MnO_3 single crystal is studied over a broad range of temperatures (78–340 K), magnetic fields (0–16 T), and wave numbers (20–9000cm^(-1)). The optical conductivity gradually changes from a Drude-like behavior to a broad peak feature near 5000cm-1 in the ferromagnetic state below the Curie temperature T_C=307K. Various features of the optical conductivity bear striking resemblance to recent theoretical predictions based on the interplay between the double exchange interaction and the Jahn-Teller electron-phonon coupling. A large optical magnetoconductivity is observed near T_C