فهرست مطالب a. zangeneh

In this paper, a robust local controller has been designed to balance the power for distributed energy resources (DERs) in an islanded microgrid. Three different DER types are considered in this study; photovoltaic systems, battery energy storage systems, and synchronous generators. Since DER dynamics are nonlinear and uncertain, which may destabilize the power system or decrease the performance, distributed robust nonlinear controllers are designed for the DERs. They are based on the Lyapunov stabilization theory and super-twisting integral sliding mode control which guarantees system stability and optimality simultaneously. The reference signals for each DER are generated by a supervisory controller as a power management system. The controllers proposed in this work are robust, have fast response times, and most importantly, the control signals satisfy physical system constraints. The designed controller stability and effectiveness are also verified using numerical simulations.

Stevia rebaudiana has been used in medicine as anti-inflammatory, antioxidant, antipyretic, anti-fungal, and antibacterial agent. The present study was conducted to investigate the healing effects of S. rebaudiana ethanol extracts on cutaneous wounds in rats.

Full-thickness excisional wounds (2×2 cm) were induced on the back of 32 rats. The rats were divided into four groups as follows; untreated (control) and treated with 1 mL basal cream, 1 mL S. rebaudiana ethanol extract 10%, and 1 mL tetracycline (3%) for 20 days (short term). Animals of each group were euthanized at 20 day post-injury and wounds were assessed through macroscopic and microscopic analyses.

During the experiment, S. rebaudiana indicated a significant reduction in the wound area compared to other groups. Parameters such as arrangement of the healing tissue, re-epithelilization and epithelial formation demonstrated considerable changes when compared to the control. In addition, treatment with S. rebaudiana decreased the total number of cells, fibrocytes/fibroblasts ratio, neutrophils, and lymphocytes and enhanced the number of blood vessels and fibroblasts at 20 day.

The present study demonstrated the wound healing activity of S. rebaudiana, lending credence to the folkloric use in the treatment of cutaneous wounds.