## 5 Conclusions  
In this paper, we have developed a mathematical model to investigate the unsteady two-dimensional magnetohydrodynamic (MHD) flow and heat transfer of an incompressible electrically conducted fluid. This study was conducted to analyze the multiple slip effects on magneto-hydrodynamic unsteady Casson nano-fluid flow over a non-linear porous shrinking/stretching sheet in the presence of a heat source with Soret effect. Appropriate similarities have been used for transformations and the governing partial differential equations (PDEs) are rendered into a system of ordinary differential equations (ODEs). The resulting system of ordinary differential equations was solved numerically with an efficient and validated finite element method (FEM). We also use a special case of the present model to compare our results with previous studies. A parametric study has been performed to explore the mass and heat transfer characteristics, and also the impact of different parameters, of the flow. The following are the results that can be concluded from the present study.  
* The cause of reducing the fluid velocity near the region of the boundary layer is the increment in values of slip, suction, magnetic field, and unsteady parameters.
* The increment in thermal buoyancy parameters \(\lambda_{1},\lambda_{2},\lambda_{3}\) and slip parameters cause decreasing the skin-friction coefficient while increasing the local Nusselt number and Sherwood number.
* Decreasing the value of the Sherwood number causes an increasing value of the solutal slip parameter, Schmidt number, and Soret number, but the effect is the opposite with increasing values of the unsteadiness, magnetic, and suction parameters.
* With the increasing value of the magnetic parameter \(M\), the slip velocity parameter and suction parameter are found to be reduced in the velocity profile.
* The skin-friction coefficient decreases with the increasing value of slip, magnetic, and unsteadiness parameters, but the effect is the opposite for increasing values of thermal buoyancy, suction parameter, and solutal buoyancy.
* The increment of the values of buoyancy parameter, injection parameter, and heat source parameter cause an increase in the velocity profile.  
[PERSON] modeled the problem and wrote the manuscript. [PERSON] thoroughly checked the mathematical modeling and English corrections. B.A. helped in MATLAB coding. S.M., and S.A. writing--review and editing. [PERSON] contributed to the results and discussions. All authors finalized the manuscript after its internal evaluation.  
This work was supported by the National Natural Science Foundation of China (No. 51676152), Equipment Advance Research Field Foundation (No. 61402070302), and Fundamental Research Funds for the Central Universities (No. zrzd2017012).  
The first author acknowledge with thanks the [PERSON] for his continuous guidance throughout the work at Xian Jiaotong University China, National Natural Science Foundation of China, Equipment Advance Research Field Foundation, Fundamental Research Funds for the Central Universities for technical and financial support for this research project. Authors would also like to ac- knowledge and express their gratitude to the Chinese Government Scholarship Council (CSC) for the scholarship award.  
The authors declare no conflict of interest.