Buckling of Tapered Heavy Columns with Constant Volume

This paper studies the buckling of standing columns under self-weight and tip load. An emphasis is placed on linearly tapered columns with regular polygons cross-section whose volume is constant. Five end conditions for columns are considered. The differential equation governing the buckling shapes of the column is derived based on the equilibrium equations of the buckled column elements. The governing equation is numerically integrated using the direct integration method, and the eigenvalue is obtained using the determinant search method. The accuracy of the method is verified against the existing solutions for particular cases. The effects of side number, taper ratio, self-weight, and end condition on the buckling load and mode shape are investigated. The contribution of self-weight acting alone to the buckling response is also explored. For a given column volume, especially, the buckling length and its stress distribution of the columns with different geometries and end conditions are estimated.

Catalytic Ozonation with Activated Carbon for Treatment of Humic Substances in Water

Ozonation of the ubiquitous and poorly biodegradable humic acid in aquatic system was conducted in the presence of activated carbon with the aim of catalyst. The optimum operating parameters deduced from this study was GAC amount of 16.5 v/v% (GAC column volume per reactor volume) in the humic acid solution of initial pH 9. DOC removal rate in Ozone/GAC process was higher than the sum of Ozone alone and GAC adsorption process. Formaldehyde formation in Ozone/GAC process was less than in Ozone alone and GAC adsorption process. The part of molecular size distribution under 10 k Dalton were increased in the Ozone/GAC process.

Study of Extraction of Total Alkaloids from Caulophyllum Robustum

Objective: Optimizing the extraction of total alkaloids from Caulophyllum robustum. Methods: The taspine which is a type of alkaloids of Caulophyllum robustum is selected as the target index. First, developing the HPLC analysis protocol; second, using orthogonal design method to optimize the hydrochloric acid leaching protocol; third, using cation exchange column to isolate the alkaloids and examining the optimal conditions. Results: the optimal conditions of hydrochloric acid leaching protocol is using 7 column volume of 1% hydrochloric acid for 3 times. The materials are loaded onto the LSD001 cation exchange column with optimal pH 4 and flowrate 2ml/mL, the elution buffer is 10 column volume 5% hydrochloric acid. After desalting, the yield of alkaloids is 1.35% which includes 6.83% of taspine.