الاستخبارات في العهد المكي: دراسة تحليلية

Security is most important need of every state and community. Surveillance and keeping eye on the enemy are the core responsibilities of every state. All the absolute qualities of a leader can be found in The Holy Prophet (P.B.U.H). Therefore, the first nucleus of security education was in Makkah and expanded with the expansion of the Da’wah till the declaration of Madina as a Islamic state. There are various studies on the subject of surveillance, but they did not cover all aspects of Sīrah in Makkī era regarding the various steps and methods of surveillance. This article investigates how the Holy Prophet (P.B.U.H) maintained the security measures during Makkī era to ensure the security of all his companions and followers. In the First section of this article definition and history of intelligence was discussed, followed by the various techniques of surveillance used in different occasions by the Prophet (P.B.U.H). The last section of the article focused on the techniques used in Makkī era. The article further elaborates the practical steps taken by Prophet (P.B.U.H) to secure his companions and their families from the opponents to the extent possible, like migration to Habash and finally to Madina which concluded in establishment of a free state for Muslims.

Biomechanics of the Spermatozoa Transport Through the Human Cervical Canal

In this thesis mathematical models of the spermatozoa transport through the Newtonian, Jeffrey and couple stress fluids filled in the cervical canal are developed and investigated theoretically. Modeling of the biomechanical model provides the partial differentials equations and the subsequent equations are solved analytically. Physical quantities like pressure gradient, mucus velocity, propulsive velocity, time mean flow rate, mucus temperature and heat transfer coefficients are examined for the appurtenant parameters. Salientfeaturesofthepumpingcharacteristicsareobserved. Itisnoticedthatthepropulsive velocity of the swimming sheet of the spermatozoa enhances for higher Reynolds number, lower Froude number, and vertical canal. It is intriguing to take note of that, maximal slippage on the upper cervical wall and zero slippage on the lower cervical wall amplify the probability of the spermatozoa to prepare a fertilized ovum. It is found that pressure rise facilitates the motion of spermatozoa to fertilize an ovum in the female reproductive tract whereas pressure drop inverts the direction of spermatozoa to the vagina and controls the probability of pregnancy. It is clear that the inclusion of porous medium lessens the propulsive velocity of the spermatozoa. Minute impact of phase difference on propulsive velocity is evident. The spermatozoa attain their maximum propulsive velocity for nonporous cervical walls. An increment in slip parameter and Reynolds number cause enhancement in the propulsive velocity of the spermatozoa. Effects of constant, linear, sinusoidal, logarithmic and exponential secreting velocities on propulsive velocity are also explored. Furthermore,comparisonofthepropulsivevelocityofnon-Newtonianfluidwith the propulsive velocity of Newtonian fluid is made. Comparison of the current analysis with the existing literature and experimental data is also made.