Voltage Regulation Utilizing Electric Vehicle Rapid Chargers in a Distribution System

From growing interests in the environment issues, promotion of photovoltaic power generation (PV) is accelerated in the world. Meanwhile, rapid chargers (RCs) for popularized electric vehicles are being installed in urban areas. These two trends in distribution system might cause severer voltage fluctuation problems. On the other hand, a RC can provide the reactive power support, which is capable of voltage regulation. Based on this viewpoint, this paper proposes a new framework of voltage regulation, in which the reactive power compensation by RCs is actively utilized. The proposed voltage regulation method combines two different control functions with consideration for over‐compensation avoidance. This paper ascertains the validity of proposed voltage regulation method through numerical simulations.     

Effects of docosahexaenoic acid or arachidonic acid supplementation on gene expression and contractile force of rat cardiomyocytes in primary culture

While fatty acids play essential roles in the physiology of the myocardium, conventional culture media contain little lipid. We previously revealed that rat neonatal myocardium mainly contains docosahexaenoic (DHA), linoleic (LA), and arachidonic (AA) acids as polyunsaturated fatty acids (PUFAs), and these contents in cultured cardiomyocytes derived from fetal rats were markedly lower than those in the neonatal myocardium. In this study, we first assessed the effects of supplementation of DHA, LA, or AA on the fatty acid contents and the percentage change of contractile area in primarily cultured rat cardiomyocytes. Based on this assessment, we then evaluated the effects of DHA or AA supplementation on mRNA expression and further directly measured the contractile force of cardiomyocytes with the supplementations. This study revealed that percentage change of contractile area was maximized under 20 μM DHA or 50 μM AA supplementation while LA supplementation did not affect this contraction index, and that a widespread upregulation tendency of the mRNA expression related to differentiation, maturity, fatty acid metabolism, and cell adhesion was seen in the cultured cardiomyocytes with supplementation of DHA or AA. In particular, upregulation of the gene expression of cellular adhesion molecules connexin43 and N-cadherin were remarkable, whereas the effects on differentiation and maturation were less pronounced. Correspondingly, the increase of the percentage change of the contractile area of cardiomyocyte clusters in culture dishes with the supplementations was significant, whereas the enhancement of the contractile force was modest. These results suggest that supplementation of DHA or AA to the fetal cardiomyocyte culture may play effective roles in preventing the de-differentiation of the cardiomyocytes in culture and that the enhancement of the contractile performance may be mainly attributed to the improvement of intercellular connection.     

表面波等离子体制备碳膜的膜厚分布及工艺优化

表面波等离子体(surface-wave-sustained plasma,SWP)是近年发展起来的一种新型低压,高密度等离子体.应用这种技术,采用物理气相沉积(PVD)方法,很容易实现镀膜过程中的离子束辅助沉积(IBAD),从而制备出性能优异的无氢碳膜.采用一种新型的SWP源沉积出无氢碳膜,用郎缪尔探针测试了不同工艺条件下的等离子体密度分布.采用正交实验设计方法,研究了沉积薄膜的膜厚分布特性,分析了膜厚分布与等离子体密度分布的关系,并对制备的工艺参数进行了优化.结果表明,这种新型的SWP源,能够产生高达1011～1014cm-3的等离子体密度.薄膜在整个圆周方向都具有良好的均匀性,沿轴向约为75 mm(膜厚差值±5%).研究中同时获得了影响表面波等离子体膜厚均匀性的显著因素和制备薄膜均匀性最好的工艺条件.