College of Education for Women, University of Kufa discussed a Ph.D. thesis on using of integral transformation to solve partial differential equations and its applications by the postgraduate student, Ms. Rehab Ali Khudair.

The thesis aimed at finding new double transformations, which are called double ZZ transformations, which are complex and a useful tool characterized by speed and accuracy to obtain solutions for hydrodynamic pressure, load bearing and the thermal equation that describes the movement of molecules in synovial fluid.

The thesis concluded with using the double ZZ transform as a powerful tool to solve the equations of motion and continuity in hydrodynamic and compressive lubrication and to solve the thermal equation that describes the movement of molecules in synovial fluid and using the complex double ZZ transform to estimate stress peaks in the knee joint for daily activities.

The thesis recommended that it is possible to develop the double ZZ transform and the double complex ZZ transform to solve a system of ordinary differential equations and solve partial differential equations with variable coefficients.