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...

Motivated by events in which black holes can lose their environment due to tidal interactions a binary system, we develop waveform model the deformability interpolates between finite value (dressed hole) at relatively low frequency and zero (naked high frequency. We then apply this example case of hole dressed with an ultralight scalar field investigate detectability Love number Einstein Telesc...

This paper inspects possible influence of solar cycles on earthquakes through of statistical analyses. We also discussed the mechanism that would drive the occurrence of increasing of earthquakes during solar maxima. The study was based on worldwide earthquakes events during approximately four hundred years (16002010).The increase of earthquakes events followed the Maxima of Solar cycle, and al...

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 ...

In 1969, Roger Penrose proposed a mechanism to extract rotational energy from Kerr black hole. With this, he inspired two lines of investigation in the years after. On one side, process, as it became known, allowed comparison between black-hole mechanics and thermodynamics. other, opened path quantum description those objects. This paper provides novel take on events that led rise thermodynamic...

The electron density as measured in the transition region of a coronal hole, a ‘quiet’ Sun region at disk center plus an active region shows variations of up to a factor of two at Te ∼ 1.5 105 K, lasting at most only a few minutes. There is remarkable agreement between the number of such variations, their temporal variability and duration in the coronal hole and ‘quiet’ Sun datasets, consistent...

On 14 September 2015, the twin detectors belonging to the Laser Interferometer Gravitational Wave Observatory (LIGO) made a triple discovery: the first direct detection of gravitational waves (GWs), first observation of formation of a black hole and first observation of a binary black hole. Since then LIGO has reported two other events and a marginal candidate. These discoveries have heralded a...