astrophysics is becoming now an integral part of general physics. considering the black hole theory ,which is a new and exciting branch of relativistic astrophysics, we see many connections between elementary particle physics and astrophysics. in this article we attempt to explain the development of star physics ,in an easy ,understandable manner. previous knowledge of relativistic theory or cl...

The use of blasting cost (BC) prediction to achieve optimal fragmentation is necessary in order to control the adverse consequences of blasting such as fly rock, ground vibration, and air blast in open-pit mines. In this research work, BC is predicted through collecting 146 blasting data from six limestone mines in Iran using the artificial neural networks (ANNs), gene expression programming (G...

The fracture and crack growth of mechanical structures is a usual phenomenon which is due to the application of tensile, cyclic loading or thermal stresses on the structure. So introducing of methods to prevent the crack growth is useful. Afterward, one of the repairing methods of crack growth, consisting to make a hole in the crack tip to elimi-nate the sharp corners, was explained. This metho...

The role played by the mutual information of subsystems on Page curve is explored in this paper. With total system consisting black hole and radiation, together with inclusion island, we observe that vanishing between $B_+$ $B_-$ which turn means disconnected phase entanglement wedge corresponding to $B_+\cup B_-$, yields a time scale order scrambling time. This results independent expression f...

Faults are the most critical tectonic factors in geological structures, which have major economic impacts on mining economics. Thus it is necessary to understand faults in order to identify the actual risks and complications associated with mining. In the preliminary investigation of the Sonda-Jherruck coalfield, 3D geological modeling was not performed. The purpose of this work was to perform ...

a new method for determination of residual stresses in the bottom layers of laminated composites is developed. in this method the residual stresses are determined by performing a consecutive drilling of laminated composites in the center of the rosette and recording the strains after drilling each layer. the depth of the hole in each step is equal to the thickness of each layer and the maximum ...

Chern-Simons gravity rotating Kerr-type black hole solutions are revisited from the point of view their scalarization, namely examining back reaction pseudoscalar axion fields on geometry. To lowest order in an angular momentum expansion, and a long range approximation for both field configuration its onto metric, such had been discussed first time context string theory. In this work, we extend...

A test particle falling into a classical black hole crosses the event horizon and ends up in the singularity within finite eigentime. In the ‘more realistic’ case of a ‘classical’ evaporating black hole, an observer falling onto a black hole observes a sudden evaporation of the hole. This illustrates the fact that the discussion of the classical process commonly found in the literature may beco...