Optical filtering of solar radiation to increase performance of concentrator systems

Solar cell overheating due to high irradiation levels is a significant problem facing concentrator systems. Some form of cooling is needed to maintain the highest possible performance of such systems. Liquid filters may be used to inhibit unwanted solar radiation from reaching the cell and thus limit cell-operating temperatures. The performance of the cooling will depend on the optical properties of the liquid filter applied, as illustrated in this paper on the basis of different filters. An ideal filter is identified and its effects on the systems are described. It is-shown, on the basis of system modeling calculations, that cell performance could be increased by up to 25% using an ideal filter. Such a system can reach an efficiency of 22% in a. realistic working environment compared to a STC value of 16%. The absorbed part of the incident radiation can be used as heat source, so adding to the potential initial value of the system

Dose-dependent effects of mosapride citrate on duodenal and cecal motility in donkeys (Equus asinus)

Prokinetic drugs are used for the management of gastrointestinal motility disorders in horses; however, little is known about their efficacy in donkeys. Therefore, the aim of the present study was to evaluate the effect of different doses of mosapride citrate on duodenal and cecal motility in normal donkeys. Six donkeys (n = 6) were used in a crossover study. Mosapride citrate was administered orally via a nasogastric tube at dose rate of 1, 2 and 3 mg kg−1. Duodenal and cecal motility were evaluated using ultrasonography before administration and at 15, 30, 60, 120 and 180 min post-administration. There was a significant increase of duodenal contractions (p < 0.05) after 30 min of mosapride citrate administration at 3 mg kg−1 with a prolonged (p < 0.05) prokinetic effect at 2 mg kg−1. Cecal contractions were significantly increased (p < 0.05) after 15 min at different doses of mosapride with a prolonged effect at 3 mg kg−1. The results of the present study indicate that mosapride citrate has a dose-dependent prokinetic effect on the duodenal and cecal contractions in healthy donkeys. Further studies need to determine whether mosapride citrate is effective in treatment of intestinal disorders in donkey