Effect of particle size of coal dust on explosion pressure

The effect of the particle size of coal dust on explosion pressure and the rising rate of explosion pressure is studied. Three coal dusts from Lingan Coal Mine in Canada and Datong Coal Mine in China are selected to test. The influence of particle size on the maximum explosion pressure P max and maximum pressure rising rate (d p /d t ) max of each coal dust was tested experimentally. The results indicate that with the decrease of particle size of coal dusts, explosion pressure increases on condition of the same concentration. If the concentration of coal dust is different, the maximum explosion pressure appears at the concentration of 500 g/m^3. The smaller the particle size of coal dusts, the larger the rising rate of explosion pressure of coal dust. When the concentration of coal dust is 500 g/m^3, the rising rate of explosion pressure of each coal dust is the maximum.

Investigation of pressure loading rates on streaming potentials in bone

When load is applied to bone,it deforms and causes fluid pressure to build up in bone.The pressure gradient between different portions of the bone microcnannels drives fluid flow through them.This kind of bone fluid flow can induces the streaming potentials which are considered to play a role for bone remodeling.Aimed to determine the impact of ribbed rough inner surfaces of the microchannels on the streaming potentials,streaming potentials were measured as bone fluid flowed through the mcrospaces of thin cylinder bone samples under different pressure loading rates.The results show that the streaming potentials decrease with the increase of the pressure loading rates.A digital simulation calculation was performed and the results demonstrated that there were turbulent flows near the inner wall surfaces,which making the streaming potentials smaller in bone microchannels.