The extraction technology of total flavonoid from dandelion was optimized by single factor screening and orthogonal test. The method of solvent extraction was used, and ethyl acetate was used as solvent, solid-liquid ratio, extraction temperature and extraction time were invested to study the effects of the extraction. On the basis of single factor, three-factor and three-level orthogonal test were carried out to optimize the extraction process of flavonoid from dandelion. The results showed that the factors of the extraction effect of flavonoid were influenced by the time of extraction, the ratio of material to liquid, and the temperature of extraction in turn, it was found that the time of extraction had the most significant effect on the extraction of flavonoid from dandelion. The results showed that the optimal conditions of extraction were as following: the ratio of solid-liquid was 1:70, the temperature of extraction was at 70 ℃, and the time of extraction was 1.5 h. Flavonoid was extracted from dandelion at the best conditions, flavonoid was obtained, and the content of flavonoid was 7.18%. The process is simple, reproducible, economical and feasible.
ORIGINAL RESEARCH ARTICLE | March 18, 2020
Impact of Insulation and Sheathing PVC Mixture on the Physical Properties
The cable insulation and sheathing industry uses many different types of plastics depending on usage, application. Physical and electrical properties are one of the most important factors that compete and help to choose these materials when compared with other materials. These properties change with the change of the chemical components of the plastics mixture. The use of PVC material in the manufacture of cable wire coating has been used for decades. In this study, the effect of changing the proportions of the used components in the PVC mixture of the physical and electrical properties of cable wiring materials was investigated. Emphasis was placed on three properties: Tensile Strength and Loss of Mass and Insulation Resistance. In this study author discussed how to enhance these properties and improve them by working to raise the proportions of some of the substances in the PVC mixture while preserving other properties. The study aimed to prove the strong relationship between some components of PVC mixture used in cable insulation and sheathing industry and the physical and electrical properties of these products, and then focus on three components in the mixture and three properties. Random samples were taken and the mean percentages of the ingredients in the mixes were taken using various tools and several statistical methods such as correlation coefficient and regression analysis to prove the relationship between the ratios of some materials and the properties. After the analysis, the p-value was less than 0.05, which reinforces the relationship between the ratio and the properties. Finally, the physical and electrical properties of PVC blends can be improved by changing component ratios to reach the optimized mixture for specific use and application, taking into account other competitive issues such as the final price of the product, environmental impact, and others issues.
Scholars Middle East Publishers
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.