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.
In this study, the effect of construction joints on the performance of reinforced concrete beams was experimentally investigated. Seven beam specimens, with dimensions of 200×100×1000 mm, were fabricated. The variables were considered including; the location and configuration of the joints. One beam was cast without a joint (Reference specimen), two specimens were fabricated with a one horizontal joint located either at tension, or compression zone. The fourth
beam had two horizontal joints placed at tension, and compression area. The remaining specimens were with one or two inclined joints positioned at the shear span or beam’s mid-span. The specimens were subjected to a monotonic central concentrated loading until the failure. T
Abstract
This research aims to measure the effect of Self competency of the Managers in their behavior from the view point of the working individual in the organization since the behavior of managers is considered to be one of the essential variables in the organization which can affect the performance and the commitment of the working individual. the questioners was used to gather the data and the Iraqi Rail Road co. was the field of the study . and a random sample of (36) individual of the subordinates of the managers society of the study and used the (SPSS) statistical program was used in the analysis of the data of the research . the findings refer to the existence of a
... Show Moreأهمية 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 MoreCeramic coating compose from a ceramic mixture (MgO, Al2O3) and metall (Al-Ni) were produced by Thermal Spray Technique. The mixed ratio of used materials Al:Ni (50%) and 40% of Al2O3 and 10% MgO. This mixture was spray on a stainless steel substrate of type (316 L) by using thermal spray with flame method and at spraying distances (8, 12, 16 and 20) cm, then the prepared films were treated by laser and thermal treatment. After that performing a hardness and adhesion tests were eximined. The present study shows that the best value of the thermal treatment is 1000 ℃ for 30 mint; the optimum spray distance is 12 cm and most suitable laser is 500 mJ where the microscopic and mechanical character
... Show MoreAbstract
In the present work the effect of bearing compliance on the performance of high speed misaligned journal bearing lined with a compliant PTFE liner lubricated with bubbly oil at high speeds has been studied. The effect of induced oil film temperature due to shearing effect has been implemented. Hydrodynamic effect of the complaint bearing and the influence of aerated oil have been examined by the classical thermohydrodynamic lubrication theory modified to include the effect of oil film turbulence and oil film temperature with suitable models for bubbly oil viscosity and density. The effect of liner elastic deformation has been implemented by using Winkler model. The effects of variable density and s
... Show MoreThe aim of this work is to produce samples from Iraqi raw materials like Husyniat Bauxite (raw and burnt) and to study the effect of some additives like white Doekhla kaolin clays and alumina on that material properties were using sodium silica as a binding material. Five mixtures were prepared from Bauxite (raw and burnt) and kaolin clays, with an additive of (40) ml from sodium silica and alumina of (2.5, 5, 7.5,10 wt %) percentage as a binding material. the size grading was through sieving. The formation of all specimens was conducted by a measured gradually semi-dry pressing method under a compression force of (10) Tons and humidity ratio ranging from (5-10) % from mixture weight. Drying all specimens was done and then they were burn
... Show MoreThe present research is descriptive and analytical by nature; it practically presents the method of implementing the standard pattern in an unconventional way using the bias-cut line. The study aims at investigating the variables of bias-cut and their suitability for fitting large-shaped Iraqi ladies. It also aims at exploring the artistic and innovative features of the bias-cut. Therefore, one needs to understand the rules and basics of clothing and the nature of the body to reach the maximum degree of control.Consequently, the study is to answer the following questions: What is the effectiveness of tailoring on the bias-cut in fitting a standard template of a large-shaped Iraqi ladies? Is it possible to obtain from the offered possibil
... Show MoreA study of the hadiths of supplication orchestration