A numerical investigation is adopted for two dimensional thermal analysis of rocket thrust chamber wall (RL10), employing finite difference model with iterative scheme (implemented under relaxation factor of 0.9 for convergence) to compute temperature distribution within thrust chamber wall (which is composed of Nickel and Copper layers). The analysis is conducted for different boundary conditions: only convection boundary conditions then combined radiation, convection boundary conditions also for different aspect ratio (AR) of cooling channel. The results show that Utilizing cooling channels of high aspect ratio leads to decrease in temperature variation across thrust chamber wall, while no effects on heat transferred to the coolant is indicated. The radiation has a considerable effect on the computed wall temperature values.
The current research aimed to identify the cognitive-behavioral therapy on people with depression, through the following hypothesis (there are no statistically significant differences in the sample before and after cognitive-behavioral therapy). The importance of research is highlighted through the use of cognitive-behavioral therapy, to be used in treating depression, anxiety and fears by health institutions. It is also considered as a reference for psychological studies related to this topic to be added to our libraries that already suffer from a scarcity of this type of resources. The cognitive-behavioral therapy was used in the treatment of five male subjects.
The study revealed the existence of statistically significant diff
... Show MoreRotating blades are the important parts in gas turbines. Hence, an accurate mathematical estimation (F.E.M) of the stresses and deformations characteristics was required in the design applications to avoid failure. In recent year’s there are researchers interest in the effect of temperature on solid bodies has greatly increased, The main of this study investigated the thermal and rotational effects. So, the thermal stresses due to high pressure and temperature are studies, also determine the steady state stresses and deformations of rotating blades due to mechanical effect. Many parameters such as thickness and centre of rotating are investigated in this paper. The
... Show MoreThe research work covers a study of the possibility of producing porous ceramic bodies
as a thermal insulators by adding fired Dechla kaolinite (grog)to the same non burned
kaolinite.
Different weight percentage ranged between (0,15,25,35and40)from grog and sawdust
passed through mesh 50 to Deuchla-clay kaolinit.Cylindrical shape samples (30mm diameter
and 30mm height) were prepared by the semi-dry methed,moulding pressure was 50 N/mm
2
.
After drying at 110
o
c,the samples were burnet in the furnace at temperatures
900,950,1000,1050,and 1100
o
c. The sawdust burnt out and leaves air spaces which contribute
to the high thermal insulation value.
The fired samples were investigated to de
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أهمية البحث والحاجة اليه :
الحمد لله رب العالمين القائل (( وانك لعلى خلق عظيم )) (سورة القام :4) وصلى الله وسلم وبارك على نبينا محمد القائل " انما بعثت لأتمم مكارم الاخلاق " مسند احم: رقم الحديث 8595.
ان الاهتمام بالمشكلات السلوكية من اهم ركائن التربية والتعليم وتأتي تأتي اهميتها من ان التعيم يعين التغيير في سلوك الفرد نحو الافضل تحت تأثير الظروف والخبرات والمعارف والمهارات ال
... Show MorePraise be to Allah and peace be upon our master and lover of our hearts and our souls doctor Muhammad and divine , especially the rest of God in Aladdin , and a curse on all the enemies to the day of judgment ,
After : The issue of education of man , and brought up within the curriculum properly and comprehensively cannot be completed for the seriousness and accuracy without revelation , the Qur'an inspiring , than when gentle expert , is a factory of man and humanity , in fact ... is the process of modifying behavior, one of the goals of education community at various levels in the family the school and the whole university and other educational institutions and community-based factories humanity that th
... Show Moreالملخص : يعد السلوك التوكيدي من السلوكيات الضرورية للإنسان خصوصاً في مرحلة الطفولة لأنها هي مرحلة تكوين الشخصية وترسيخها لديهم ولأن الطفل الذي يفتقد السلوك التوكيدي، سوف يفشل في التعبير عن مشاعره وآراءه وهذه تشكل مشكلة خصوصاً في السنوات الأخيرة أذ قلت المبادئ والأخلاق الحميدة بسبب التغيرات التي طرأت على شعبنا التي لابد على الوالدين من تلافيها والسيطرة على التلميذ وتزويده بالحب والعاطفة وأشعاره بأنه محبوب
... Show MorePractically, torsion is normally combined with flexure and shear actions. Even though, the behavior of reinforced concrete continuous beams under pure torsion is investigated in this study. It was performed on four RC continuous beams under pure torsion. In order to produce torsional moment on the external supports, an eccentric load was applied at various distances from the longitudinal axis of the RC beams until failure.
Variables considered in this study are absolute vertical displacement of the external supports, torsional moment’s capacity, angle of twist and first cracks occurrences. According to experimental results; when load eccentricity increased from 30cm to 60cm, the absolute vertical displacement i
... Show MoreIndustrial buildings usually are designed to sustain several types of load systems, such as dead, live, and dynamic loads (especially the harmonic load produced by rotary motors). In general, these buildings require high-strength structural elements to carry the applied loads. Moreover, Reactive Powder Concrete (RPC) has been used for this purpose because of its excellent mechanical strength and endurance. Therefore, this study provides an experimental analysis of the structural behaviors of reinforced RPC beams under harmonic loads. The experimental program consisted of testing six simply supported RPC beams with lengths of 1500 mm, widths of 150 mm, and thicknesses of 200 mm under harmonic loading with varied frequencies between 1
... Show More
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