Study on negative friction of pile foundation in homogeneous layered soil in collapsible loess area.

The collapsible nature of loess soil can lead to issues such as additional settlement of pile foundations, reduced pile strength, and decreased bearing capacity, posing a significant threat to the safety of structures in loess regions. In this paper, considering the collapsibility of loess and the layered characteristics of foundation soil, a load transfer model for single piles in homogeneous layered soil was established using the load transfer method. Simultaneously, based on the elastoplastic theory, a differential equation controlling the negative skin friction of single piles caused by the collapsibility of loess was derived.

Photocatalyzed surface modification of poly(dimethylsiloxane) with polysaccharides and assay of their protein adsorption and cytocompatibility.

An improved approach for the surface modification of poly(dimethylsiloxane) (PDMS) using carboxymethyl cellulose (CMC), carboxymethyl beta-1,3-dextran (CMD), and alginic acid (AA) was investigated. The PDMS substrates were first oxidized in a H(2)SO(4)/H(2)O(2) solution to transform the Si-CH(3) groups on their surfaces into Si-OH groups. Then methacrylate groups were grafted onto the substrates through a silanization reaction using 3-(trimethoxysilyl)propyl methacrylate.