Sunscreen application is a common strategy used to prevent the damage induced by UV radiations. In the last 30 years a variety of protective agents against UV exposure have been developed： physical filters, chemical ...Sunscreen application is a common strategy used to prevent the damage induced by UV radiations. In the last 30 years a variety of protective agents against UV exposure have been developed： physical filters, chemical filters and organic filters. Physical filters are the safest： they scatter and reflect UV rays, but are difficult to apply on the skin. Chemical filters are capable of absorbing these rays, they are cosmetically pleasant, but recent studies suggest a toxicological nature for some of these agents. Organic filters are the newest advance in sun products. Since 2003 the COLIPA Index [Europe] has regulated sun product availability on the market. In the USA, the FDA establishes the classification and the safety of sun products, which are considered topical medical drugs. This article summarizes the dermatologist＇s point of view, according to the patient＇s request, professional ethics and increasing offer of sun product.展开更多
For the handling, treatment and utilization of fly ash from biomass combustion its chemical composition and physical properties are important. In this study eight filter fly ashes from different grate-fired biomass co...For the handling, treatment and utilization of fly ash from biomass combustion its chemical composition and physical properties are important. In this study eight filter fly ashes from different grate-fired biomass combustion plants were investigated. In fly ash from straw combustion high concentrations of（K） were found, whereas in the fly ash from wood combustion the concentrations of Ca and Mg were higher. The average concentration of PO3-4was similar in both types of fly ashes. In all wood fly ashes some measured heavy metal concentrations were above the limits for utilization. The straw fly ashes were much less contaminated and can be utilized. For wood fly ash most parameters showed little variation, except from one fly ash where the dust pre-separator is in poor condition. The average values were： mass median diameter 4.3 ± 0.8 μm, spread of particle size distribution19 ± 11, particle density 2620 ± 80 kg/m^3 and angle of repose 50°± 1°. The density of the straw fly ashes is lower（2260 ± 80 kg/m^3） and the spread of the size distribution is higher（72 ± 24）.For one straw combustion fly ash the values of the mass median diameter and the angle of repose were similar to the values of wood combustion fly ash, for the other straw fly ash the values differed considerably. While the particle size of this fly ash was much smaller,surprisingly the angle of repose was also lower. This can be attributed to the formation of small agglomerates in this fly ash, which were not disintegrated without a certain stress.展开更多
文摘Sunscreen application is a common strategy used to prevent the damage induced by UV radiations. In the last 30 years a variety of protective agents against UV exposure have been developed： physical filters, chemical filters and organic filters. Physical filters are the safest： they scatter and reflect UV rays, but are difficult to apply on the skin. Chemical filters are capable of absorbing these rays, they are cosmetically pleasant, but recent studies suggest a toxicological nature for some of these agents. Organic filters are the newest advance in sun products. Since 2003 the COLIPA Index [Europe] has regulated sun product availability on the market. In the USA, the FDA establishes the classification and the safety of sun products, which are considered topical medical drugs. This article summarizes the dermatologist＇s point of view, according to the patient＇s request, professional ethics and increasing offer of sun product.
文摘For the handling, treatment and utilization of fly ash from biomass combustion its chemical composition and physical properties are important. In this study eight filter fly ashes from different grate-fired biomass combustion plants were investigated. In fly ash from straw combustion high concentrations of（K） were found, whereas in the fly ash from wood combustion the concentrations of Ca and Mg were higher. The average concentration of PO3-4was similar in both types of fly ashes. In all wood fly ashes some measured heavy metal concentrations were above the limits for utilization. The straw fly ashes were much less contaminated and can be utilized. For wood fly ash most parameters showed little variation, except from one fly ash where the dust pre-separator is in poor condition. The average values were： mass median diameter 4.3 ± 0.8 μm, spread of particle size distribution19 ± 11, particle density 2620 ± 80 kg/m^3 and angle of repose 50°± 1°. The density of the straw fly ashes is lower（2260 ± 80 kg/m^3） and the spread of the size distribution is higher（72 ± 24）.For one straw combustion fly ash the values of the mass median diameter and the angle of repose were similar to the values of wood combustion fly ash, for the other straw fly ash the values differed considerably. While the particle size of this fly ash was much smaller,surprisingly the angle of repose was also lower. This can be attributed to the formation of small agglomerates in this fly ash, which were not disintegrated without a certain stress.
