Azarbaijan Shahid Madani University

About: Azarbaijan Shahid Madani University is a education organization based out in Tabriz, Iran. It is known for research contribution in the topics: Graphene & Nanocomposite. The organization has 1477 authors who have published 3186 publications receiving 30278 citations. The organization is also known as: Azarbaijan University.

Energy conditions in f(R,G)gravity

Abstract: Modified gravity is one of the most favorable candidates for explaining the current accelerating expansion of the Universe. In this regard, we study the viability of an alternative gravitational theory, namely $$f(R,G)$$ , by imposing energy conditions. We consider two forms of $$f(R,G)$$ , commonly discussed in the literature, which account for the stability of cosmological solutions. We construct the inequalities obtained by energy conditions and specifically apply the weak energy condition using the recent estimated values of the Hubble, deceleration, jerk and snap parameters to probe the viability of the above-mentioned forms of $$f(R, G)$$ .

Study on a High Voltage Gain SEPIC-Based DC–DC Converter With Continuous Input Current for Sustainable Energy Applications

Abstract: A high step-up dc–dc converter is proposed in this paper. The presented converter benefits from some advantages such as high voltage gain and continuous input current, which makes it suitable for the renewable energy applications. The presented converter is based on the SEPIC converter. However, the converter voltage gain is improved by employing a coupled inductor and two voltage multipliers. A passive clamp circuit is also added to the proposed converter that increases the voltage gain and reduces the voltage stress on the main switch. Thus, a switch with low $R_{{\text{DS(on)}}}$ will be needed that decreases the conduction loss. Besides, the voltage stress on the output diode in the proposed converter is reduced, which alleviates reverse recovery problem. The steady-state analysis of the proposed converter is discussed in this paper. The analysis is verified with experimental results under the output power of 245 W.

A generalization to the Rastall theory and cosmic eras

Abstract: A generalized version for the Rastall theory is proposed showing the agreement with the cosmic accelerating expansion. In this regard, a coupling between geometry and the pressureless matter fields is derived which may play the role of dark energy, responsible for the current accelerating expansion phase. Moreover, our study also shows that the radiation field may not be coupled to the geometry in a non-minimal way which represents that the ordinary energy-momentum conservation law is respected by the radiation source. It is also shown that the primary inflationary era may be justified by the ability of the geometry to couple to the energy-momentum source in an empty flat FRW universe. In fact, this ability is independent of the existence of the energy-momentum source and may compel the empty flat FRW universe to expand exponentially. Finally, we consider a flat FRW universe field by a spatially homogeneous scalar field evolving in potential $$\mathcal {V}(\phi )$$ , and study the results of applying the slow-roll approximation to the system which may lead to an inflationary phase for the universe expansion.