$4\mathrm{.}7[$SECTION $4\mathrm{.}3]$ A material is subjected to a distributed moment field such that every infinitesimal element $($with volume $dV=d{x}_{1}d{x}_{2}d{x}_3)$ is subjected to a moment $dV($where $$ is the moment per unit volume$)$ about an axis parallel to the $e_1-$direction. How will this affect the symmetry of the stress tensor $?$ Find an explicit expression for the relation between the shear components of $$ in a Cartesian coordinate system.