scholarly journals INFLUENCE OF FRICTION IN THE ARMORED FACE CONVEYOR CHAIN ON DYNAMICS AND ENERGY EFFICIENCY

2021 ◽  
pp. 15-20
Author(s):  
Alexander Osichev ◽  
Andrii Tkachenko
Keyword(s):  
Energy Efficiency ◽  
Electric Drive ◽  
Dimensional Space ◽  
Moving Load ◽  
Three Dimensional ◽  
Viscous Friction ◽  
Spatial Form ◽  
Time Dynamic ◽  
Resonance Frequencies ◽  
Dimensional Space Time

The range of values ​​of the coefficient of resistance to movement of the chain of typical longwall armored face conveyors and the coefficient of inner viscous friction in the chain, both immersed in the moving load and during the idle run of the conveyor, is estimated. The computer model of the conveyor is built as a multi-mass elastic-viscous stretched closed chain without sag with the number of masses n = 200 and one induction drive motor located in the head of the conveyor. Using the constructed model, three-dimensional space-time dynamic characteristics of speeds and forces in the chain of the CP72 longwall armored face conveyor are obtained. Start up to rated speed v≈1 m / s and the working process is simulated with an unloaded conveyor. The spatial form of frictional self-oscillations in the model with distributed parameters is shown. The resonance frequencies and amplitudes of oscillations of the efforts in the circuit and the length of the corresponding spatial waves have been determined. It was found that at the first and second resonance frequencies, self-oscillations are not excited, since the damping effect of the electric drive is quite pronounced in this frequency band. The direct connection of vibration amplitudes with the energy efficiency of the conveyor electric drive is indicated.

Dynamics of a composite system in a point source-induced space–time

2021 ◽  
pp. 2150144
Author(s):  
Abdullah Guvendi
Keyword(s):  
Point Source ◽  
Composite System ◽  
Dimensional Space ◽  
Energy Levels ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Space Time ◽  
Spin Coupling ◽  
Quantum Oscillator ◽  
Dimensional Space Time

We investigate the dynamics of a composite system ([Formula: see text]) consisting of an interacting fermion–antifermion pair in the three-dimensional space–time background generated by a static point source. By considering the interaction between the particles as Dirac oscillator coupling, we analyze the effects of space–time topology on the energy of such a [Formula: see text]. To achieve this, we solve the corresponding form of a two-body Dirac equation (fully-covariant) by assuming the center-of-mass of the particles is at rest and locates at the origin of the spatial geometry. Under this assumption, we arrive at a nonperturbative energy spectrum for the system in question. This spectrum includes spin coupling and depends on the angular deficit parameter [Formula: see text] of the geometric background. This provides a suitable basis to determine the effects of the geometric background on the energy of the [Formula: see text] under consideration. Our results show that such a [Formula: see text] behaves like a single quantum oscillator. Then, we analyze the alterations in the energy levels and discuss the limits of the obtained results. We show that the effects of the geometric background on each energy level are not same and there can be degeneracy in the energy levels for small values of the [Formula: see text].

QUANTUM COMPUTING WITH NON-ABELIAN QUASIPARTICLES

2007 ◽  
Vol 21 (08n09) ◽  
pp. 1372-1378 ◽  
Author(s):  
N. E. BONESTEEL ◽  
L. HORMOZI ◽  
G. ZIKOS ◽  
S. H. SIMON
Keyword(s):  
Dimensional Space ◽  
Quantum Hall ◽  
Three Dimensional ◽  
Fractional Quantum ◽  
Fractional Quantum Hall ◽  
Quantum Operations ◽  
Topological Quantum ◽  
Dimensional Space Time ◽  
Two Space Dimensions ◽  
Topological Quantum Computation

In topological quantum computation quantum information is stored in exotic states of matter which are intrinsically protected from decoherence, and quantum operations are carried out by dragging particle-like excitations (quasiparticles) around one another in two space dimensions. The resulting quasiparticle trajectories define world-lines in three dimensional space-time, and the corresponding quantum operations depend only on the topology of the braids formed by these world-lines. We describe recent work showing how to find braids which can be used to perform arbitrary quantum computations using a specific kind of quasiparticle (those described by the so-called Fibonacci anyon model) which are thought to exist in the experimentally observed ν = 12/5 fractional quantum Hall state.

scholarly journals Concept of the time in language and text (contextual time markers)

2021 ◽  
Vol 14 (1(14)/2020) ◽  
pp. 143-149
Author(s):  
Natalia Grushina
Keyword(s):  
Foreign Language ◽  
Cognitive Linguistics ◽  
Dimensional Space ◽  
Human Life ◽  
Three Dimensional ◽  
Cognitive Approach ◽  
The Social ◽  
Russian Literary ◽  
Dimensional Space Time ◽  
Perception Of Time

The aim of this paper is to study different time representations in language and text. Time is an abstract category firmly connected to human life, it can be considered to be the fourth dimension of reality, used to describe events in three-dimensional space. Time has been studied from different points of view and in different aspects. The perception of time can vary depending on the social and cultural environment. That is why it is so important to pay special attention to a variety of time representations when studying a foreign language. In this article I consider different time markers represented in language (English and Russian) and contextual time markers we can find in texts for reading comprehension activities at advanced levels when studying Russian as a foreign language. I compare language and contextual time markers using a cognitive approach to text units. As an example, I take time markers from the texts published in a popular Russian literary magazine Novy mir at the turn of the 21 century. Novy mir is a very famous in Russia for its liberal position and history within the dissident movement during Soviet epoch Keywords: concept of time, time markers, text and discourse, cognitive linguistics

scholarly journals Lorentz-violating effects in three-dimensional QED

2014 ◽  
Vol 29 (22) ◽  
pp. 1450112 ◽  
Author(s):  
R. Bufalo
Keyword(s):  
Quantum Electrodynamics ◽  
Lagrangian Density ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Space Time ◽  
Nonminimal Coupling ◽  
Coupling Term ◽  
Interaction Terms ◽  
Higher Derivative ◽  
Dimensional Space Time

Inspired in discussions presented lately regarding Lorentz-violating interaction terms in B. Charneski, M. Gomes, R. V. Maluf and A. J. da Silva, Phys. Rev. D86, 045003 (2012); R. Casana, M. M. Ferreira Jr., R. V. Maluf and F. E. P. dos Santos, Phys. Lett. B726, 815 (2013); R. Casana, M. M. Ferreira Jr., E. Passos, F. E. P. dos Santos and E. O. Silva, Phys. Rev. D87, 047701 (2013), we propose here a slightly different version for the coupling term. We will consider a modified quantum electrodynamics with violation of Lorentz symmetry defined in a (2+1)-dimensional space–time. We define the Lagrangian density with a Lorentz-violating interaction, where the space–time dimensionality is explicitly taken into account in its definition. The work encompasses an analysis of this model at both zero and finite-temperature, where very interesting features are known to occur due to the space–time dimensionality. With that in mind, we expect that the space–time dimensionality may provide new insights about the radiative generation of higher-derivative terms into the action, implying in a new Lorentz-violating electrodynamics, as well the nonminimal coupling may provide interesting implications on the thermodynamical quantities.

CANDU Reactor Space-Time Kinetic Model for Load Following Studies

2010 ◽  
Vol 133 (5) ◽  
Author(s):  
Lingzhi Xia ◽  
Jin Jiang
Keyword(s):  
Kinetic Model ◽  
Neutron Flux ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Space Time ◽  
Reactor Model ◽  
Load Following ◽  
Dimensional Space Time ◽  
Reactor Kinetic ◽  
Reactor Space

This paper presents the development of a three-dimensional space-time neutronic kinetic model of a Canadian deuterium uranium (CANDU) reactor using a modal method. In this method, the reactor space-time neutron flux is synthesized by a time-weighted series of precalculated neutron flux modes. The modes are eigenfunctions of the governing neutron diffusion equation during reference steady-state operation. The xenon effect has also been considered. The reactor model is then implemented within a simulation platform of a CANDU6 reactor regulating system in MATLAB/SIMULINK. A nondimensionalized SIMULINK representation of the reactor kinetic model is established. The behavior of the reactor during load following transients has been simulated using the developed reactor-modeling module. The simulation results prove the efficiency of the model. A three-dimensional neutron flux distribution during transients is represented.

The Fast Three-Dimensional Space-Time Neutron Kinetic Model for Cartesian Geometry and Cylindrical Geometry

2016 ◽  
Author(s):  
Zhifeng Li ◽  
Hongchun Wu ◽  
Chenghui Wan ◽  
Tianliang Hu
Keyword(s):  
Dimensional Space ◽  
Three Dimensional ◽  
Space Time ◽  
Cylindrical Geometry ◽  
Neutron Diffusion ◽  
Diffusion Kinetics ◽  
Dimensional Space Time ◽  
Cartesian Geometry ◽  
Predictor Corrector ◽  
Three Dimensional Space

In order to raise computation speed on the premise of enough numerical accuracy, the Predictor-Corrector Improved Quasi-Static (PC-IQS) method and Nodal Green’s Function Method (NGFM) were combined to solve the three-dimensional space-time neutron diffusion kinetics problems for Cartesian geometry. In addition, the improved quasi-static method and the Krylov algorithm were applied to solve the three-dimensional space-time neutron diffusion kinetics problems for cylindrical geometry. Based on the proposed model, the program of three-dimensional neutron space-time kinetic code has been tested by the two-dimensional and three-dimensional transient numerical benchmarks. The numerical results obtained by this work were in good agreement with the reference solutions.

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