College of Science

This study aimed to modify Staphylococcus aureus by using physical and chemical mutagens and subjections the cell wall to the hydrolytic activity of lysozyme. Chemical mutagenesis by N-methyle-N-nitro-N-nitroguanidine, was achieved by incubating the cell suspension of Staphylococcus aureus with 100μg/ml MNNG for different periods of time (5, 10, 15, 20, 25 and 30min).Aliquot of 100μl of the bacterial suspension subjected to the lethal and mutagenic effect of MNNG, then spread on BHI agar and incubated at 37°C over night in dark.

The main objective of this thesis is to study and solve the Volterra integral and integro-differential equation and some scientific models for real life problems.This objective may be divided into three sub objectives, as follows: The first one is to classify and study the subject of the integral equations and to supply the basic definitions related to the Volterra integral and integro-differential equations. In the second sub objective we used the " dafterdar-jafari method " to solve Volterra integral and integro-differential equations.

An Effective and secure protection of sensitive information is the primary concern in communication systems or network storage systems, it is important for any information process to ensure data is not being tampered. To achieve confidentiality and integrity of multimedia information, various Secret Sharing Schemes (SSS) have been developed.This thesis presents a (2,n) threshold Secret Sharing Scheme, which is one of the types of SSS and a special  kind of  (k, n) threshold scheme.