**Acknowledgements**

At the beginning we would like to thank our project supervisor, Dr. Alnazeir Osman Hamza for the valuable guidance and advices, also the ministry of science and technology Renewable Energy Institute (the Photovoltaic Encapsulation & Manufacturing Unit (Khartoum-south)) for providing us with a good environment and facilities to complete this project.

Also we will take this opportunity to thank Dr. Mohamed Altaib Alfadni the Executive Manager of Sharg alneel specialized hospital & Dr. Alfatih Abdelgader Alfadni who support us with a microscope device for testing.
