scholarly journals Post-Newtonian Lagrangian of an N -body system with arbitrary mass and spin multipoles

2020 ◽  
Vol 102 (2) ◽  
Author(s):  
Sergei M. Kopeikin
Keyword(s):  
Body System ◽  
Arbitrary Mass

Center of Mass Theorem and the Separation of Variables for Two-Body System on a Three-Dimensional Sphere

2020 ◽  
Vol 23 (3) ◽  
pp. 306-311
Author(s):  
Yu. Kurochkin ◽  
Dz. Shoukavy ◽  
I. Boyarina
Keyword(s):  
Constant Curvature ◽  
Jacobi Equation ◽  
Separation Of Variables ◽  
Center Of Mass ◽  
Three Dimensional ◽  
Relative Distance ◽  
Dimensional Sphere ◽  
Body System ◽  
Spaces Of Constant Curvature ◽  
Hamilton Jacobi Equation

The immobility of the center of mass in spaces of constant curvature is postulated based on its definition obtained in [1]. The system of two particles which interact through a potential depending only on the distance between particles on a three-dimensional sphere is considered. The Hamilton-Jacobi equation is formulated and its solutions and trajectory equations are found. It was established that the reduced mass of the system depends on the relative distance.

OPTIMIZATION OF THE WING SHAPE IN THE WING-BODY SYSTEM AT HYPERSONIC FLOW

2009 ◽  
Vol 40 (2) ◽  
pp. 151-165
Author(s):  
S. D. Zhivotov ◽  
V. S. Nikolaev
Keyword(s):  
Hypersonic Flow ◽  
Wing Shape ◽  
Body System

Dynamic Performance of High-Speed Electric Multiple Unit within Multi-Body System Simulation

2019 ◽  
Vol 12 (4) ◽  
pp. 339-349
Author(s):  
Junguo Wang ◽  
Daoping Gong ◽  
Rui Sun ◽  
Yongxiang Zhao
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Body System ◽  
High Speed Railway ◽  
Evaluation Indexes ◽  
Actual Operation ◽  
Multiple Unit ◽  
The Stability ◽  
Multi Body

Background: With the rapid development of the high-speed railway, the dynamic performance such as running stability and safety of the high-speed train is increasingly important. This paper focuses on the dynamic performance of high-speed Electric Multiple Unit (EMU), especially the dynamic characteristics of the bogie frame and car body. Various patents have been discussed in this article. Objective: To develop the Multi-Body System (MBS) model of EMU, verify whether the dynamic performance meets the actual operation requirements, and provide some useful information for dynamics and structural design of the proposed EMU. Methods: According to the technical characteristics of a typical EMU, a MBS model is established via SIMPACK, and the measured data of China high-speed railway is taken as the excitation of track random irregularity. To test the dynamic performance of the EMU, including the stability and safety, some evaluation indexes such as wheel-axle lateral forces, wheel-axle lateral vertical forces, derailment coefficients and wheel unloading rates are also calculated and analyzed in detail. Results: The MBS model of EMU has better dynamic performance especially curving performance, and some evaluation indexes of the stability and safety have also reached China’s high-speed railway standards. Conclusion: The effectiveness of the proposed MBS model is verified, and the dynamic performance of the MBS model can meet the design requirements of high-speed EMU.

The Institutional Future of the Covenants

2018 ◽  
Author(s):  
Felice D Gaer
Keyword(s):  
Human Rights ◽  
Body System ◽  
International Human Rights ◽  
Human Rights Treaties ◽  
Treaty Monitoring ◽  
Treaty Body ◽  
International Human ◽  
Normative Standards ◽  
Individual Petition

Longstanding proposals to strengthen implementation of the international human rights treaties have often focused on procedural reforms such as harmonizing methods of work or consolidating ten treaty monitoring bodies into one. This article reviews past reform efforts and then considers proposals to create stronger individual petition mechanisms—including a ‘world court’—as a way of strengthening human rights implementation. After discussing these proposals, the author offers additional ways to make the system more effective and efficient. She rejects the oft-suggested proposal to create a ‘world court’ for human rights, noting legal, organizational, logistical, and financial obstacles. Rather than rushing to tear down the current treaty body system, the author offers a proposal for determining how consolidation of petition proceedings might affect normative standards.

scholarly journals Impact of Increased Travel Speed of a Transportation Set on the Dynamic Parameters of a Mine Suspended Monorail

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1528
Author(s):  
Kamil Szewerda ◽  
Jarosław Tokarczyk ◽  
Andrzej Wieczorek
Keyword(s):  
Computational Model ◽  
Travel Speed ◽  
Body System ◽  
Emergency Braking ◽  
System Method ◽  
Underground Coal Mines ◽  
Program Environment ◽  
Underground Transportation ◽  
Multi Body ◽  
Transportation Routes

The method of increasing the efficiency of using one of the most common means of auxiliary transport in underground coal mines—suspended monorails—is presented. Increase of velocity is one of the key parameters to improve the efficiency and economical effect related with the underground auxiliary transport. On the other hand, increasing the velocity results in bigger value of force acting on the suspended monorail route and its suspensions. The most important issue during increasing the velocity is ensuring the required safety for the passengers and not overloading the infrastructure. In order to analyze how increasing velocity influences the level of loads of the route suspension and the steel arch loads, the computational model of suspended monorail was developed. The computational model included both the physical part (embedded in the program environment based on the Multi-Body System method) and the components of the monorail control system. Two independent software environments were cooperating with each other through the so-called co-simulation. This model was validated on the base of results obtained on the test stand. Then, the numerical simulations of emergency braking with different values of velocity were conducted, which was not possible with the use of physical objects. The presented study can be used by the suspended monorail’s producers during the designing process, and leads to increase the safety on underground transportation routes.

scholarly journals Classical gravitational self-energy from double copy

2020 ◽  
Vol 2020 (11) ◽  
Author(s):  
Gabriel Luz Almeida ◽  
Stefano Foffa ◽  
Riccardo Sturani
Keyword(s):  
Gravitational Field ◽  
Binary System ◽  
The Self ◽  
Gravitational Coupling ◽  
Leading Order ◽  
Body System ◽  
Self Energy ◽  
Composite Systems ◽  
Body Dynamics ◽  
Double Copy

Abstract We apply the classical double copy to the calculation of self-energy of composite systems with multipolar coupling to gravitational field, obtaining next-to-leading order results in the gravitational coupling GN by generalizing color to kinematics replacement rules known in literature. When applied to the multipolar description of the two-body system, the self-energy diagrams studied in this work correspond to tail processes, whose physical interpretation is of radiation being emitted by the non-relativistic source, scattered by the curvature generated by the binary system and then re-absorbed by the same source. These processes contribute to the conservative two-body dynamics and the present work represents a decisive step towards the systematic use of double copy within the multipolar post-Minkowskian expansion.

scholarly journals Gravitational polarization of the quantum vacuum caused by two point-like bodies

2021 ◽  
Vol 503 (4) ◽  
pp. 5091-5099
Author(s):  
Dragan Slavkov Hajdukovic ◽  
Sergej Walter
Keyword(s):  
Dark Matter ◽  
Solar System ◽  
Charge Density ◽  
Numerical Method ◽  
Quantum Vacuum ◽  
Body System ◽  
Complex Fluid ◽  
The Impact ◽  
The Universe ◽  
Gravitational Charge

ABSTRACT In a recent paper, quantum vacuum was considered as a source of gravity, and the simplest, phenomenon, the gravitational polarization of the quantum vacuum by an immersed point-like body, was studied. In this paper, we have derived the effective gravitational charge density of the quantum vacuum, caused by two immersed point-like bodies. Among others, the obtained result proves that quantum vacuum can have regions with a negative effective gravitational charge density. Hence, quantum vacuum, the ‘ocean’ in which all matter of the Universe is immersed, acts as a complex fluid with a very variable gravitational charge density that might include both positive and negative densities; a crucial prediction that can be tested within the Solar system. In the general case of ${N \ge {\rm{3}}}$ point-like bodies, immersed in the quantum vacuum, the analytical solutions are not possible, and the use of numerical methods is inevitable. The key point is that an appropriate numerical method, for the calculation of the effective gravitational charge density of the quantum vacuum induced by N immersed bodies, might be crucial in description of galaxies, without the involvement of dark matter or a modification of gravity. The development of such a valuable numerical method, is not possible, without a previous (and in this study achieved) understanding of the impact of a two-body system.

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