This directory contains the pdf files of the lectures given in the course. 

File 

poro.pdf 

was used first, only chapters 4, 5 were from that pdf file were
covered (low- and high frequency Biot's equations of motion)

File diffusion_length_biot.pdf 

contains the calculation of the estimate  of the diffusion
length (or  Biot skin  depth) associated with the diffusion equation for slow
Biot waves in the low-frequency range.