Use of Articulated Transport Systems in the Mining Industry

The work is devoted to the possibility and prospects of the use of all-wheels drive articulated transport systems in the mining complex. A comparative analysis of the traditional methods of exporting minerals in open pit mining and the method of using active trailed elements are given. The trailer has a load factor several times higher than the same rate for mining dump trucks. The use of an active trailer makes it possible to reduce the mass of the tractor and trailer by almost 40 tons and increase the specific power of the road train. © Published under licence by IOP Publishing Ltd

Using the simulation modeling with stochastic estimation of trafficability of forest transport systems

Forecasting trafficability of logging and forest transport systems on the ground, which have a multi-sectional layout solution is considered in the paper. Trafficability problems are evaluated from the point of view of the stochastic character of indicators of traction properties - the forces of resistance to movement and the adhesion force of the driving wheels with the supporting surface. With the stochastic estimation of trafficability the law of Gaussian distribution for random values of the rolling resistance coefficient and the two-parameter Weibull distribution law with a negative asymmetry coefficient or values of the shape parameter greater than 4 for the cohesion coefficient was adopted. A stochastic approach to the evaluation of trafficability allows to ensure a rational distribution of the power flows between propulsors of the transport-technological system, which is shown in this paper. © 2019 Published under licence by IOP Publishing Ltd

Innovative material based on wood waste for application in special purpose vehicles

The article presents innovative composite wood material DS-1 with a powder binding, which is used in special purpose vehicles. Vehicles for transporting radioactive waste for its recycling and disposal, and radiodiagnostics mobile complexes intended for conducting massive X-ray have been considered. The composition of material DS-1 has been revealed, experiments have been listed and a table with physical and mechanical properties has been given. Relying on experimental analysis data it can be concluded that implementation of innovative composite material DS-1 with a powder binder using barium sulphate helps solve the problem of lead replacement with lighter environmentally friendly material and contributes to complex use of wood raw materials Using a low-toxic binder in the material obtained makes its production innocuous and environmentally friendly and and solves a number of economic and energy-saving problems. © 2019 Published under licence by IOP Publishing Ltd

Using the simulation modeling with stochastic estimation of trafficability of forest transport systems

Forecasting trafficability of logging and forest transport systems on the ground, which have a multi-sectional layout solution is considered in the paper. Trafficability problems are evaluated from the point of view of the stochastic character of indicators of traction properties - the forces of resistance to movement and the adhesion force of the driving wheels with the supporting surface. With the stochastic estimation of trafficability the law of Gaussian distribution for random values of the rolling resistance coefficient and the two-parameter Weibull distribution law with a negative asymmetry coefficient or values of the shape parameter greater than 4 for the cohesion coefficient was adopted. A stochastic approach to the evaluation of trafficability allows to ensure a rational distribution of the power flows between propulsors of the transport-technological system, which is shown in this paper. © 2019 Published under licence by IOP Publishing Ltd

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

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

Dynamic Coupling Between Links Of Articulated Transport Systems

The issues of improving the operational properties of transport systems are considered. Various ways to improve productivity, economic and environmental performance, operational reliability, as well as improve and automate the transport system controls are shown. One of the most important issues in the theory of movement, i.e., the effective distribution of the power flow between the drive axles and sections is considered. The coupling between the transport system links is estimated. The coupling between the links of active articulated multi-section machines has been analyzed based on various variants of the kinematic misalignment in the drive. The state graph of a two-section active articulated transport and production machine is considered. The coupling between the links of the articulated transport system is considered and formalized for the pole trailer supported simultaneously by two or more machine sections. The areas of further link coupling analysis based on the state graph of a two-section active articulated transport system are determined. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG

О ДИАГРАММЕ СОСТОЯНИЯ СИСТЕМЫ Cu–Ni–Mn

By means of the theoretical analysis and based on the experimental data, the part of the Cu–Ni–Mn structural diagram from 0 to 20 % Ni and from 30 to 50 % Mn has been specified. The supposition, which is contained in a number of works, of the existence in the ternary Cu–Ni–Mn state diagram of the line, along which the zero crystallization range alloys are arranged, is shown to be incorrect. The alloys in the double Cu–Mn and Ni–Mn systems have the zero crystallization range only. The primary supposition of impossibility to present nonequilibrium crystallization according to Petrov–Scheil with lacking of the minimum line in the Cu–Ni–Mn system has not been confirmed because formerly the investigations were carried out with a model system in which there observed a convex line of the liquidus curve on the polythermal cross-section joining the minima in the double systems. The present work shows this line that is concave towards the temperature decrease.С помощью теоретического анализа и на основании экспериментальных данных уточнена часть диаграммы состояния Cu–Ni–Mn от 0 до 20 % Ni и от 30 до 50 % Mn. Показано, что содержащееся в ряде работ предположение о существовании в тройной системе Cu–Ni–Mn линии, по которой располагаются сплавы с нулевым интервалом кристаллизации, неверно. Нулевой интервал кристаллизации имеют лишь сплавы в двойных системах Cu–Mn и Ni–Mn. Высказанное первоначально предположение о невозможности представить неравновесную кристаллизацию по Петрову–Шейлю при отсутствии линии минимума в системе Cu–Ni–Mn не подтвердилось, так как прежде исследования выполнялись на модельной системе, в которой на политермическом сечении, соединяющем минимумы в двойных системах, имелась выпуклая линия ликвидуса. В настоящей работе показано, что эта линия вогнута в сторону понижения температуры

Direct generation of optical vortices

A detailed scheme is established for the direct generation of optical vortices, signifying light endowed with orbital angular momentum. In contrast to common techniques based on the tailored conversion of the wave front in a conventional beam, this method provides for the direct spontaneous emission of photons with the requisite field structure. This form of optical emission results directly from the electronic relaxation of a delocalized exciton state that is supported by a ringlike array of three or more nanoscale chromophores. An analysis of the conditions leads to a general formulation revealing a requirement for the array structure to adhere to one of a restricted set of permissible symmetry groups. It is shown that the coupling between chromophores within each array leads to an energy level splitting of the exciton structure, thus providing for a specific linking of exciton phase and emission wavelength. For emission, arrays conforming to one of the given point-group families’ doubly degenerate excitons exhibit the specific phase characteristics necessary to support vortex emission. The highest order of exciton symmetry, corresponding to the maximum magnitude of electronic orbital angular momentum supported by the ring, provides for the most favored emission. The phase properties of the emission produced by the relaxation of such excitons are exhibited on plots which reveal the azimuthal phase progression around the ring, consistent with vortex emission. It is proven that emission of this kind produces electromagnetic fields that map with complete fidelity onto the phase structure of a Laguerre-Gaussian optical mode with the corresponding topological charge. The prospect of direct generation paves the way for practicable devices that need no longer rely on the modification of a conventional laser beam by a secondary optical element. Moreover, these principles hold promise for the development of a vortex laser, also based on nanoscale exciton decay, enabling the production of coherent radiation with a tailor-made helical wave front

Permian palaeomagnetism of East Kazakhstan and the amalgamation of Eurasia

Most of Kazakhstan belongs to the Ural–Mongol belt, the tectonic evolution of which is poorly understood as demonstrated by disparate tectonic models suggested thus far. We undertook a palaeomagnetic study of Upper Permian basalts and andesites from two localities in east Kazakhstan in order to evaluate the final stages of the evolution of this belt and Eurasian amalgamation. Thermal demagnetization revealed a single pre-tilting characteristic component of ubiquitously reversed polarity from all samples. The mean declination of this remanence from one locality agrees rather well with the Permian European palaeomeridian, whereas that from the other is clockwise rotated by 28°± 8° . The overall mean inclination of −49°± 4° differs by 9.7°± 4.2° from the reference inclination calculated, for our localities, from the Eurasian mean pole for the 245–260 Ma interval and is in agreement with 260–275 Ma data. We account for the observed pattern by either a slightly erroneous rock age (lithologies are somewhat older than indicated by geological data) or non-dipole (octopole) components of the geomagnetic field. Because significant relative motion of the study area with respect to Eurasia is not demonstrated, we conclude that welding of Kazakhstan, Europe and Siberia was essentially completed by Mid-Permian time.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73262/1/j.1365-246X.2003.01879.x.pd