20 research outputs found
Magnetic Brane of Cubic Quasi-Topological Gravity in the Presence of Maxwell and Born-Infeld Electromagnetic Field
The main purpose of the present paper is analyzing magnetic brane solutions
of cubic quasi-topological gravity in the presence of a linear electromagnetic
Maxwell field and a nonlinear electromagnetic Born-Infeld field. We show that
the mentioned magnetic solutions have no curvature singularity and also no
horizons, but we observe that there is a conic geometry with a related deficit
angle. We obtain the metric function and deficit angle and consider their
behavior. We show that the attributes of our solution are dependent on cubic
quasi-topological coefficient and the Gauss-Bonnet parameter.Comment: 15 pages and 8 figure
Reissner-Nordstr\"om Black Holes in Quintic Quasi-topological Gravity
This paper presents a study on charged black holes in quintic
quasi-topological gravity, where we construct numerical solutions and
investigate their thermodynamics and conserved quantities. We verify the first
law of thermodynamics and compare our findings with that of Einstein gravity.
We examine the physical properties of the solutions, considering anti-de
Sitter, de Sitter, and flat solutions. Our analysis shows that anti-de Sitter
solutions exhibit thermal stability, whereas de Sitter and flat solutions do
not. Finally, we discuss the implications of our results and possible future
research directions.Comment: 27 pages, 9 Figure
Black Holes in (Quartic) Quasitopological Gravity
We construct quartic quasitopological gravity, a theory of gravity containing
terms quartic in the curvature that yields second order differential equations
in the spherically symmetric case. Up to a term proportional to the quartic
term in Lovelock gravity we find a unique solution for this quartic case, valid
in any dimensionality larger than 4 except 8. This case is the highest degree
of curvature coupling for which explicit black hole solutions can be
constructed, and we obtain and analyze the various black hole solutions that
emerge from the field equations in dimensions. We discuss the
thermodynamics of these black holes and compute their entropy as a function of
the horizon radius. We then make some general remarks about -th order
quasitopological gravity, and point out that the basic structure of the
solutions will be the same in any dimensionality for general apart from
particular cases.Comment: LaTex, 9 figures, 27 pages. A new section on holographic
hydrodynamics is added. Introduction and concluding remarks have been revise
Investigation of the structure via to transitions in QCD
We investigate the structure of the mesons via
analyzing the semileptonic , and
transitions in the framework of the three--point
QCD sum rules. We consider the meson in two ways, the pure
state and then as a mixture of two and states.
Such type rare transitions take place at loop level by electroweak penguin and
weak box diagrams in the standard model via the flavor changing neutral current
transition of . The relevant form factors are calculated taking into
account the gluon condensate contributions. These form factors are numerically
obtained for case and plotted in terms of the unknown mixing angle
, when the meson are considered as mixture of two
and states. The obtained results for the form factors are used to
evaluate the decay rates and branching ratios. Any future experimental
measurement on these form factors as well as decay rates and branching
fractions and their comparison with the obtained results in the present work
can give considerable information about the structure of this meson and the
mixing angle .Comment: 33 Pages, 11 Figures and 5 Table
Supply and protected different population of Litopenaeus vannamei subadult zero foster (F_0) from difference provinces Iran
Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free
Supply and protected different population of Litopenaeus vannamei subadult zero foster (F0) from difference provinces Iran
Nowadays, Litopenaeus vannamei are the most important species of farmed penaeidae shrimp in the world that is rapidly replacing native species in areas aquaculture. Due to demand increase for this species culture, shrimp displacement to different areas may be associated with some potential pathogens transferred to new areas farmed. Therefore, in this study were prepared bi-osecurity conditions for specific disease-free production of L. vannamei. Thereafter, three populations (Molokaei, High health and mix of Molokaei and High health) of the shrimp various reserves were detected base on origin and genetic indexes such as: observed heterozygosity, expected heterozygosity, allele frequency, coefficient inbreeding, genetic differentiation, genetic distance and genetic identity. On the other hand, epidemiological studies indicate non pathogens (viral, bacterial, fungal and parasitic) recognition of different populations selected in the quarantine salon. The bioassay results showed that the average weight and length of the populations of High health and Mix significantly greater than was a population of Molokaei. The shrimp populations were stocked in fiberglass tank (five ton) and were kept separated in the quarantine salon. During maintenance shrimp of populations in the quarantine salon were evaluated living and non-living pathogens with PCR, microbiology and biochemical methods. There is not any pathogens detection from shrimp populations stocking in the quarantine salon, so the shrimps were carried over to pond for broodstock culture of specific pathogenic free