886 research outputs found
Charged anisotropic strange stars in Finslerian geometry
We investigate a simplified model for the strange stars in the framework of
Finslerian spacetime geometry, composed of charged fluid. It is considered that
the fluid consisting of three flavor quarks including a small amount of
non-interacting electrons to maintain the chemical equilibrium and assumed that
the fluid is compressible by nature. To obtain the simplified form of charged
strange star we considered constant flag curvature. Based on geometry, we have
developed the field equations within the localized charge distribution. We
considered that the strange quarks distributed within the stellar system are
compiled with the MIT bag model type of equation of state (EOS) and the charge
distribution within the system follows a power law. We represent the exterior
spacetime by the Finslerian Ressiner-Nordstr{\"o}m space-time. The maximum
anisotropic stress is obtained at the surface of the system. Whether the system
is in equilibrium or not, has been examined with respect to the
Tolman-Oppenheimer-Volkoff (TOV) equation, Herrera cracking concept, different
energy conditions and adiabatic index. We obtain that the total charge is of
the order of 10 C and the corresponding electric field is of around
10 V/m. The central density and central pressure vary inversely with the
charge. Varying the free parameter (charge constant) of the model, we find the
generalized mass-radius variation of strange stars and determine the maximum
limited mass with the corresponding radius. Furthermore, we also considered the
variation of mass and radius against central density respectively.Comment: 21 pages, 13 figures, 4 table
Anisotropic strange stars in Tolman-Kuchowicz spacetime
We attempt to study a singularity-free model for the spherically symmetric
anisotropic strange stars under Einstein's general theory of relativity by
exploiting the Tolman-Kuchowicz metric. Further, we have assumed that the
cosmological constant is a scalar variable dependent on the spatial
coordinate . To describe the strange star candidates we have considered that
they are made of strange quark matter (SQM) distribution, which is assumed to
be governed by the MIT bag equation of state. To obtain unknown constants of
the stellar system we match the interior Tolman-Kuchowicz metric to the
exterior modified Schwarzschild metric with the cosmological constant, at the
surface of the system. Following Deb et al. we have predicted the exact values
of the radii for different strange star candidates based on the observed values
of the masses of the stellar objects and the chosen parametric values of the
as well as the bag constant . The set of solutions
satisfies all the physical requirements to represent strange stars.
Interestingly, our study reveals that as the values of the and
increase the anisotropic system becomes gradually smaller in size
turning the whole system into a more compact ultra-dense stellar object.Comment: 18 pages, 10 figure
Screening of Volatile Constituents of N. sativa on Calcium Depleted Heart Model
The number of deaths from cardiovascular disorders is rising every year. Nigella sativa, one of the accessible natural plants, has a broad range of pharmacological effects. The Nigella sativa seeds were removed, cleaned, and preserved in order to research the effects of the plant on the cardiovascular system. After being ground into a fine powder, the seeds were used to extract the volatile oil from the seeds using the steam distillation process. The hypodynamic model was used after the rat\u27s heart was removed. Using the standard kreb\u27s hanselet salt solution to mount the isolated heart, a typical graph was produced. As the calcium concentration was reduced, the graph\u27s negative tropic activity became apparent. When N. sativa was administered it has produced additional negative tropic effect on hypodynamic heart. At 0.1 ml produced negative tropic effect and keeps on decreasing as the dose increases by 0.2, 0.4, 0.8ml in dose dependent manner
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