Abstract:
I am thankful to my beloved parents, my wife, and my siblings for their moral support. They have
always encouraged me to overcome challenge. Utterly indebted to Mr. Faraz Iqbal Memon,
without his guidance and support this work would not have been possible. I am profoundly grateful
to my supervisor Dr. Hasan Tahir for his continued interest in planning, execution, and successful
completion of the project. It is only because of his consistent encouragement, inspiring guidance,
dynamic supervision, and sympathetic attitude that enabled me to prepare this manuscript. He will
remain a great source of inspiration and kindness for me. Heartiest thanks and gratitude are also
extended to respected committee members Dr. Qaiser Riaz and Dr. Zunera Jalil for their scholarly
contribution, valuable suggestions, and constructive criticism toward the successful completion of
this research. I am obliged to all my respectable teachers for sparing their valuable time and sharing
the knowledge. I believe that this work would not have been possible without their cooperation
and support.
I will also express my gratitude to my colleagues, who encouraged and supported me to do MS
alongside a job. Despite all the assistance provided by the supervisor, committee members and
others, I take the responsibility for any errors and omissions which may unwittingly remain.
