This work studies the determination of stiffness factors , and in ferromagnetic crystal which enter into the calculations of anisotrophic constants of ferromagnetic crystal .
However , Value intervals of C3 which coresponds to the existence of
parallel states , and antiparallel states between the magnetic crystal vector and applied magnetic field vector . In addition , the suitable intervals for the magnetic jumps between two states have been found
Kinetic studies were carried out on the reaction between ′4,4-Methylenebis
(2-methylcyclohexylamine) and dimeric fatty acid C36 in molten state by using
a catalyst of sulpheric acid compared with the same kinetic of reaction without
catalyst.
The
reaction was performed at 150, and 160 ˚C and followed by determining
the acid value of the product.The polyamidation reaction was found to be of
overall a second order until equilibrium state. Moreover, the catalyst increases
speed of the reaction. Polyamidation reaction was automatic whereas the value
of free energy was negative and the reaction was endothermic, and this is
shown in change of positive enthalpy values.
