البعد الأخلاقي في سياسة الرسول صلى الله عليه وسلم

The Arab’s tribes were diverse and were scattered all over Arabia. They were alien to any system, were unfamiliar of any rules and regulations. When the prophet PBUH came to them, He gently handled them, made them lenient, gathered them at the one true platform and eventually he was succeeded in uplifting them into the bondage of brotherhood. He guided them towards the political structure so that they can live under its shadow and follow its rules and regulations. He trained amongst them Preachers, judges, leaders and politicians. He sent his messengers to all the rulers of the worlds. These messengers were able to shake the Persians and Roman thrones which were considered the greatest empires of that time. They all got united against this newly arising force which later brought the greatest revolution in the history of humankind. The solutions presented by the Prophet PBUH while confronting the challenges in spreading his message,  enjoy the political wit, which is considered far better than the wit of political scholars and political tycoons. His ability of prior reading of the incidents, uncovers his huge potential in his prior dealing of the matters and suggesting its solutions and substitutes. His policies played a vital role in establishing the prior relations with Njashi, and later to facilitate the Muslims during their first immigration towards Abyssinia from the cruelty of the idolaters. Moreover, He chose the best time for the Treaty of Hudaybiyyah and Conquest of Mecca. He chose among his companions the one who knew the International languages and sent them as his Ambassadors to the rulers and tribal chiefs along with his written or verbal messages. He addressed the each with the method appropriate to him and suited him the best. He made best use of alliance, as he alienated the Arab tribes, from Jews and the others. In this way he was able to take a huge time to concentrate on those nations and was able to make a lot of allies. In his internal policy matters, he always tried to solve his problems, developing the society and to sabotage the malicious intentions which were planned by hypocrites, who were considered as his most dangerous enemies. His policy towards them was to admit apparently and leaving their unrevealed intentions to ALLAH. He treated them well, because he was anxious on preserving the freedom of all and the unity among his companions. When their malicious intentions started turning to become a threat to the security of Islam and started harming the interests of the society, He had not reply them strongly and dissuasively. He demolished the Mosque through which they were planning to harm the Muslim community. Moreover, he drew a line to their plans of aggression without harming anyone. He was very witty in his policies through which he was able to defeat them in the end. In this way he was able to change the course of the whole history on mankind. In this research we will try to deal with his moral wit which is considered the main characteristic of his policy.

Effects of Cooling Hole Shapes on Film Cooling Effectiveness

The present study is related to the numerical investigation of different hole shapes for film cooling performance, which is widely used for cooling of high temperature gas turbines. The adiabatic film cooling effectiveness values are determined computationally, downstream of 30o inclined cooling holes. Different hole shapes compared are circular holes, two types of triangular holes, and two types of semicircular holes. Semicircular-1 hole, which has straight edge towards windward direction and curved edge towards leeward side, is found to produce best effectiveness results. This type of hole shows much higher values of laterally averaged effectiveness at blowing ratios of 0.67 and 1.0 as compared to a full circular hole. At blowing ratios of 1.33 and 1.67, the effectiveness results from semicircular-1 hole are found similar to the results of full circular hole. The semicircular-2 holes (straight edge towards leeward direction and curved edge towards windward side) show almost similar effectiveness results as the results of a full circular hole. Same effectiveness results from either type of semicircular hole as for a full circular hole, is still highly advantageous because semicircular hole requires half mass flow of coolant as compared to the requirement for a full circular hole, to produce the same blowing ratio. Hence the loss of thermal efficiency, due to the extraction of coolant from the compressor, can be reduced by using semicircular-1 or semicircular-2 hole. Semicircular-2 holes are further investigated by arranging them in two inlined/ staggered rows. Two rows of semicircular holes are equivalent to a single row of full circular holes because in both cases coolant cost or requirement is same. Hence the results of two rows of semicircular-2 holes are compared with a single row of full circular holes. Result of spatially averaged effectiveness from two staggered rows of semicircular-2 holes is 200% or higher than that from a single row of full circular holes at all blowing ratios tested. The lowest coolant jet heights are found for two staggered rows of semicircular holes, also the counter rotating vortex pair for that case is the weakest one. In the study of compound angle orientations of a single row of circular holes, two staggered rows of semicircular-1 holes and two staggered rows of semicircular-2 holes, it is seen that for simple inclination angle (i.e., for β = 0o), the two staggered rows of semicircular-1 holes for blowing ratio of 0.67 show almost 400% higher values of spatially averaged effectiveness as compared to a single row of full circular holes. When compound angles are used, it is seen that semicircular holes (either semicircular-1 or semicircular-2) shows much higher values of spatially averaged effectiveness than single row of circular holes, especially at low orientation angles. Among two types of semicircular holes, the two staggered rows of semicircular-1 holes show higher spatially averaged effectiveness as compared to two staggered rows of semicircular-2 holes but this difference decreases with increasing orientation angle (β). Also, the two staggered rows of semicircular-1 holes without any compound angle show better spatially averaged effectiveness than from the single row of circular holes or two staggered rows of semicircular-2 holes at all orientation angles. Hence using semicircular-1 holes in staggered rows, the need of compound angles may be avoided. Finally it is recommended to use the semicircular-1 holes instead of full circular holes for much better effectiveness or for reduced coolant requirement.