ABSTRACT
In this work, a Monte Carlo ray-tracing model for the simulation and optimization of a fiber Luminescent Solar Concentrator (LSC) based on stacked layers of fiber arrays is developed and validated. The fiber LSC efficiency improvements are compared against a conventional planar LSC. We developed a new model to analyze the performance of different configurations of bulk-doped fibers and fibers constituted by a doped coating and a passive core. These configurations are analyzed also varying fiber packing geometry diameters, and length. Due to the exceptionally low absorption coefficient of the silica fibers (αwg ≈ 10-4 cm-1), concentration factors of up to 1.9 are predicted when dimensions are scaled over 1 m2, which improve more than twice the maximum concentration factor ever reported. These results serve as a preliminary theoretical study for the future development of a new LSC design based on flexible silica micro-fibers coated with Si-QDs doped poly(lauryl methacrylate) (PLMA) layers.
ABSTRACT
A 41-year-old-man without previous ischemic heart disease, developed a severe anaphylactic reaction. After administration of epinephrine (0.5 mg) the patient complained of chest pain. The electrocardiogram showed an elevation of ST segment in inferior leads. Myocardial necrosis was ruled out. Coronary arteriography disclosed normal coronary arteries. Eight months later, the patient developed severe chest pain during physical activity. ST elevation was again seen in inferior leads. ECG changes disappeared, when sublingual nitroglycerin was administered. A diagnosis of vasospastic angina was made. Exercise test was negative, during treatment with calcium-blocking agents. The patient subsequently remain free of symptoms taking medication. The physiological mechanisms of vasospastic angina and precipitating factors are discussed.