DLC-Coated Ferroelectric Membranes as Vascular Patches: Physico-Chemical Properties and Biocompatibility

In this paper, the results on the fabrication of ferroelectric membranes as vascular patches with modified surfaces are presented. For the modification of a membrane surface contacting blood, DLC coating was deposited using the pulsed vacuum arc deposition technique. The physico-chemical properties and cytotoxicity of the membranes modified under various conditions were studied. It was found that DLC coatings do not affect membrane microstructure, preserving its crystal structure as well as its high strength and elongation. It was revealed that an increase in the capacitor storage voltage results in the rise in sp2- and sp-hybridized carbon concentration, which makes it possible to control the chemical structure and surface energy of the modified surface. The experiments with 3T3L1 fibroblasts showed no toxic effects of the materials extracts.

Power Conversion System for Hybrid Battery-Capacitor Storage

Context: Thanks to the low emissions of CO2 generated by electric systems, those solutions have anincreased attention from industry and academia. However, the electrical storage systems required in alarge amount of applications must to have both high energy and power densities. Method: To meet those requirements, this paper proposes an active hybrid energy storage system(HESS), which is formed by a battery, i.e. the device with high energy density, and a capacitor, i.e. the device with high power capability. The proposed power system also protects the battery by limiting the current derivative. Results: Two sliding-mode controllers (SMC) are designed to regulate both the battery current and the load voltage. The design process guarantees the global stability and safe battery operation. Conclusions: The controller avoids the battery degradation caused by the high-frequency current components since the capacitor assumes those components demanded by the load profile.

Performance Analysis of Three-Phase DVR with Modified Switching Band Controller

This paper deals with the mitigation of voltage related PQ issues by using three phase neutral clamped VSI topology is used to realize the DVR and the design of DVR for the selection of suitable interface inductor, DC capacitor storage series resistance and the capacitance. Here three-phase four wire DVR with modified switching band controller topology is proposed, which overcome the frequent band violation, poor controllability and heavy filter currents, and compared to three-phase four wire DVR with conventional filter topology. The compensation capability of the proposed topology is analyzed based on simulation studies and corresponding results are compared with different switching control strategies. The consequent merits and demerits switching loss in VSI, ripple in compensated load voltages and error between reference injected voltages and actual injected voltages in different switching control strategies are discussed.