This study concerns a new type of heat exchangers, which is that of shell-and-double concentric tube heat exchangers. The case studies include both design calculations and performance calculations.

       The new heat exchanger design was conducted according to Kern method. The volumetric flow rates were 3.6 m³/h and 7.63 m³/h for the hot oil and water respectively. The experimental parameters studied were: temperature, flow rate of hot oil, flow rate of cold water and pressure drop.

A comparison was made for the theoretical and experimental results and it was found that the percentage error for the hot oil outlet temperature was (- 1.6%). The percentage

 هدفت هذه الدراسة الى التعرف على مدى فاعلية المعلمين في تطبيق نموذج بنائي في تدريس مادة العلوم للصف الثاني الأساسي . وقد استخدمت استراتيجيات نوعية في جمع البيانات وتحليلها . وأوضحت نتائج الدراسة ان المعلمين تقربوا أكثر إلى السلوك البنائي , وابدوا رغبة في استخدام استراتيجيات بنائية في تدريسهم للعلوم . واختتمت الدراسة بمجموعة من التوصيات .

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يسلط كتابنا الضوء على الآليات التي تم توظيفها في النص الخيالي المتناص بوعي، وكيف قُدِّمَ وشُحنَ بالنص ليجعله فريدًا يتألق بفكرته ويظل مستقلاً بخياله حتى عن الخيال المستدعى في تكوينه، لنستخرج بعض الآليات والوظائف التي قد تشترك بعضها أو جزء منها في تكوين نصوص سردية خيالية أخرى

        The scholars  are differed  about  the beginning of   feudal,some  says that it has been known  already in  the  oldest   Babylonic  period . while others   think   that has been of the Fourth  Century .some   scholars . believe that it has  began in the  time  of  the caliph al-mutwakil   (232-247 A.H) who made  anew social class from  the  military to support  him The orientlists   wrote  about the differences  between  the feudal  in Islamic  period   and The feudal in Europe

The research entitled (Image of the Religious Coup in Spain in the Middle Ages) aims to shed light on the prevailing image of the religious coup in Spain during the Middle Aga

We, at the end of the discussio about Sincere love, are discussing the
idea o platonic spinning i Dr.Ahmad Muhammed AL_Hofi in His book)

The odalisque ( chambermaid) is every  owned woman (possessed ). Her master has owned her either by buying her from the slavers who were travelling around in the lands to buy the odalisques and then selling them or they are captives of war.

  Quran said "the women are under the control of men" this doesn't mean that the men were dictators in the affairs of women . But the men were ready to bear most of their burden or loads .