Spin and center of mass comparison between the post-Newtonian approach and the asymptotic formulation

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.

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TO THE STABILITY OF TANK VEHICLES IN THE BRAKE MODE

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2019-1-257-27-32 ◽

2019 ◽

pp. 27-32

Author(s):

Denys Popelysh ◽

Yurii Seluk ◽

Sergyi Tomchuk

Keyword(s):

Mathematical Model ◽

Control Systems ◽

Distribution Systems ◽

Traffic Accidents ◽

Road Traffic ◽

Center Of Mass ◽

Dynamic Processes ◽

Course Stability ◽

The Stability ◽

Tank Vehicles

This article discusses the question of the possibility of improving the roll stability of partially filled tank vehicles while braking. We consider the dangers associated with partially filled tank vehicles. We give examples of the severe consequences of road traffic accidents that have occurred with tank vehicles carrying dangerous goods. We conducted an analysis of the dynamic processes of fluid flow in the tank and their influence on the basic parameters of the stability of vehicle. When transporting a partially filled tank due to the comparability of the mass of the empty tank with the mass of the fluid being transported, the dynamic qualities of the vehicle change so that they differ significantly from the dynamic characteristics of other vehicles. Due to large displacements of the center of mass of cargo in the tank there are additional loads that act vehicle and significantly reduce the course stability and the drivability. We consider the dynamics of liquid sloshing in moving containers, and give examples of building a mechanical model of an oscillating fluid in a tank and a mathematical model of a vehicle with a tank. We also considered the method of improving the vehicle’s stability, which is based on the prediction of the moment of action and the nature of the dynamic processes of liquid cargo and the implementation of preventive actions by executive mechanisms. Modern automated control systems (anti-lock brake system, anti-slip control systems, stabilization systems, braking forces distribution systems, floor level systems, etc.) use a certain list of elements for collecting necessary parameters and actuators for their work. This gives the ability to influence the course stability properties without interfering with the design of the vehicle only by making changes to the software of these systems. Keywords: tank vehicle, roll stability, mathematical model, vehicle control systems.

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Exploring Baryon Rich Matter with Heavy-Ion Collisions

Ukrainian Journal of Physics ◽

10.15407/ujpe64.7.583 ◽

2019 ◽

Vol 64 (7) ◽

pp. 583 ◽

Cited By ~ 1

Author(s):

S. Harabasz

Keyword(s):

Center Of Mass ◽

Heavy Ion ◽

State Density ◽

Heavy Nuclei ◽

First Order ◽

Center Of Mass Energy ◽

Ion Collisions ◽

Deconfinement Phase Transition ◽

Ground State Density

Collisions of heavy nuclei at (ultra-)relativistic energies provide a fascinating opportunity to re-create various forms of matter in the laboratory. For a short extent of time (10-22 s), matter under extreme conditions of temperature and density can exist. In dedicated experiments, one explores the microscopic structure of strongly interacting matter and its phase diagram. In heavy-ion reactions at SIS18 collision energies, matter is substantially compressed (2–3 times ground-state density), while moderate temperatures are reached (T < 70 MeV). The conditions closely resemble those that prevail, e.g., in neutron star mergers. Matter under such conditions is currently being studied at the High Acceptance DiElecton Spectrometer (HADES). Important topics of the research program are the mechanisms of strangeness production, the emissivity of matter, and the role of baryonic resonances herein. In this contribution, we will focus on the important experimental results obtained by HADES in Au+Au collisions at 2.4 GeV center-of-mass energy. We will also present perspectives for future experiments with HADES and CBM at SIS100, where higher beam energies and intensities will allow for the studies of the first-order deconfinement phase transition and its critical endpoint.

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