Experiments were carried out to investigate filtration characteristics of an electrostatic precipitator (ESP) with alternating and direct electric field corona charger. Potassium Sodium Tartrate Tetrahydrate as the material was used to generate polydisperse submicron aerosols by using Constant Output Atomizer. The results indicated that the aerosol penetration through the ESP decreased as applied voltage increased. The maximum collection efficiency of either alternating or direct electric field was more than 98%, though the applied voltage of alternating electric field was higher than that of direct electric field. However, from the viewpoint of power consumption, the direct electric field had higher power consumption rate than alternating electric field at similar collection efficiency. For example, when the 0.2 µm particle penetration was about 4%, the power consumptions of alternating and direct electric field were 16 watt and 18 watt, respectively. Hence the separation quality of alternating electric field was better than that of direct electric field. Moreover, considerably lower ozone concentration was found in alternating electric field ESP, compared to direct electric field.

This paper demonstrates that risk is unlikely to be the only factor explaining the excess return difference between macroeconomic announcement days and other trading days. We argue that investor sentiment may affect the return on the prescheduled macroeconomic news release. We find that the return on macroeconomic announcement days is much higher than the return on other days, especially when changes in investor sentiment are higher. The impact of investor sentiment on the macroeconomic announcement effect is greater when investor sentiment is higher. Our results remain valid using different investor sentiment measures and testing for heteroscedasticity in stock returns.