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Abstract: The mechanical behavior of erythrocytes is studied experimentally and numerically. In the experiment, prepared silica microbeads are attached to the surface of spherically swollen erythrocytes (red blood cells, RBCs) at room temperature (25°C). The cells are then stretched by single laser beam via the microbeads. The relation of deformation and stretching force is quantitatively assessed by the image processing of digital pictures. Meanwhile, a physical model for an axisymmetric cell is introduced to study its deformation by different level of stretching force. By comparing the experimental and numerical data, stiffness of the cell membrane can be determined and the optimal values are found to agree with other studies by different techniques such as micropipette aspiration or high frequency electric field. [Copyright &y& Elsevier]

Dezincification layer formed during corrosion or stress corrosion cracking (SCC) of brass in the ammonia solution could induce an additive stress. The effect of hydrogen on the dezincification layer-induced stress and the susceptibility to SCC were studied. The dezincification layer-induced stress was measured using the deflection method and the flow stress differential method. The susceptibility to SCC was measured using a slow strain rate test. Results showed that both the dezincification layer-induced stress and the susceptibility to SCC increased with increasing hydrogen concentration, and the hydrogen concentration dependence of the susceptibility to SCC was in a good agreement with that of the dezincification layer-induced stress. Hydrogen in brass facilitates the selective dissolution of Zn in the ammonia solution, and then enhances the dezincification layer-induced stress. [Copyright &y& Elsevier]