The purpose of the present study is to optimize the cultivation conditions for the productivities of chlorophyll and carotenoid of the microalga chlorellafusca in a flow bioreactor. The effects of CO2 concentration in...The purpose of the present study is to optimize the cultivation conditions for the productivities of chlorophyll and carotenoid of the microalga chlorellafusca in a flow bioreactor. The effects of CO2 concentration in aeration and light intensity as the culture condition were firstly examined. After the cultivation conditions as to CO2 concentration and light intensity were determined, the effects of the concentrations of KNO3, CH3COONa, NaC1 and MgSO4 in the culture medium on the chlorophyll biosynthesis and carotenoid accumulation ofC. fusca were examined. KNO3 and CH3COONa were used as the nitrogen and the organic carbon sources, respectively. They are very important nutrient sources to the microalgae. In fact, when the concentration of the nutrient sources was increased, the syntheses of chlorophyll and the carotenoid accumulation of the microalgae were promoted. Cfusca can take an organic carbon as the nutrient sources for its own growth, so the cell is activated compared to the case only in an inorganic nourishment sources. Mg2＋ is known as a raw material of chlorophyll and it can promote carotenoid accumulation. However, when it exists in excessive quantity, the microalgae receive a stress and it was difficult for microalgae to uptake such nutrient sources. In this study, it was found that there existed the optimum amounts of KNO3, CH3COONa, NaCI and MgSO4 which should be added to the culture medium.展开更多
Convection heat transfer coefficient and air pressure drop in sinter layer are important factors for the design of sinter cooling craft. Due to the lack of necessary data, the two parameters are studied by experimenta...Convection heat transfer coefficient and air pressure drop in sinter layer are important factors for the design of sinter cooling craft. Due to the lack of necessary data, the two parameters are studied by experimental method. The experimental results show that heat conduction of sinter impacts the measurement of convection heat transfer coefficient. Convection heat transfer increases with the increase of air volumetric flow rate. Sinter layer without small particles(sample I) gives higher convection heat transfer coefficient than that with small particles(sample II). Under the considered conditions, volumetric convection heat transfer coefficient is in the range of 400-1800 W/(m3·°C). Air pressure drop in sinter layer increases with the increase of normal superficial velocity, as well as with the rise of air temperature. Additionally, air pressure drop also depends on sinter particle size distribution. In considered experimental conditions, pressure drop in sinter sample II is 2-3 times that in sinter sample I, which resulted from 17% small scale particles in sinter sample II.展开更多
文摘The purpose of the present study is to optimize the cultivation conditions for the productivities of chlorophyll and carotenoid of the microalga chlorellafusca in a flow bioreactor. The effects of CO2 concentration in aeration and light intensity as the culture condition were firstly examined. After the cultivation conditions as to CO2 concentration and light intensity were determined, the effects of the concentrations of KNO3, CH3COONa, NaC1 and MgSO4 in the culture medium on the chlorophyll biosynthesis and carotenoid accumulation ofC. fusca were examined. KNO3 and CH3COONa were used as the nitrogen and the organic carbon sources, respectively. They are very important nutrient sources to the microalgae. In fact, when the concentration of the nutrient sources was increased, the syntheses of chlorophyll and the carotenoid accumulation of the microalgae were promoted. Cfusca can take an organic carbon as the nutrient sources for its own growth, so the cell is activated compared to the case only in an inorganic nourishment sources. Mg2＋ is known as a raw material of chlorophyll and it can promote carotenoid accumulation. However, when it exists in excessive quantity, the microalgae receive a stress and it was difficult for microalgae to uptake such nutrient sources. In this study, it was found that there existed the optimum amounts of KNO3, CH3COONa, NaCI and MgSO4 which should be added to the culture medium.
基金Project(51306198)supported by the National Natural Science Foundation of China
文摘Convection heat transfer coefficient and air pressure drop in sinter layer are important factors for the design of sinter cooling craft. Due to the lack of necessary data, the two parameters are studied by experimental method. The experimental results show that heat conduction of sinter impacts the measurement of convection heat transfer coefficient. Convection heat transfer increases with the increase of air volumetric flow rate. Sinter layer without small particles(sample I) gives higher convection heat transfer coefficient than that with small particles(sample II). Under the considered conditions, volumetric convection heat transfer coefficient is in the range of 400-1800 W/(m3·°C). Air pressure drop in sinter layer increases with the increase of normal superficial velocity, as well as with the rise of air temperature. Additionally, air pressure drop also depends on sinter particle size distribution. In considered experimental conditions, pressure drop in sinter sample II is 2-3 times that in sinter sample I, which resulted from 17% small scale particles in sinter sample II.
