[Effect of three mixing methods on air bubbles and solidification state of alginate impression materials].

Purpose: To evaluate the effect of full-automatic mixing machine method, clockwise manual mixing and combined eight-shaped manual mixing on air bubble content, flowability, temperature, working time and setting time of alginate impression materials.

Methods: With the same condition, alginate impression materials were mixed by three different methods. The number of bubbles, area, flowability, temperature, working time and setting time were evaluated with SPSS 24.

Removing BaP from soil by biochar prepared with medicago and corn straw using batch and solid-phase extraction method.

Low-cost materials with a highly efficient adsorption capability prepared from corn straw and medicago (abbreviated to CB and MB), which can effectively remove benzo()pyrene (BaP) from contaminated soil, were prepared at a temperature of 350 °C under limited-oxygen conditions. The appearance traits, contents of C, H, N and functional group types of CB and MB were obtained by SEM, elemental analysis and FT-IR. Through the batch method, it was found that the adsorption of BaP by CB and MB was in accordance with pseudo-secondary kinetics because the correlation coefficients are 0.