The effect of internal acoustic excitation on the leading-edge, separated boundary layers and the aerodynamic performance of NACA23015 cross section airfoil are examined as a function of excitation location with ranging frequency range (50-400) Hz of the introduced acoustic. Tests are separately conducted in two sections, open type wind tunnels at the Reynolds number of 3.3x105 for measurement at angle of attack (0, 3, 6, 9 &12) deg. and 3x104 for the visualization at angle of attack (12) deg. based on the airfoil chord. Results indicated that the excitation frequency and the excitation location are the key parameters to alter the flow properties and thus to improve the aerodynamic performance. The most effective excitation frequency is found to be equal to the shear layer instability frequency and on excitation location close to the separation point. Moreover, the lift is increased and drag reduced dramatically. The corresponding boundary layers are visualized to be reattached to the surface.
نتيجة للتطور و انفتاح الاسواق الاقتصادية عالميا ظهرت اهمية الافصاح في القوائم المالية و اعدادهايكونمبني على ( العدالة و الشفافية ) في اظهار البنود الواردة فيها ، و لان هذه القوائم تعد لا كثر من جهة مستفيدة ( اصحاب المصلحة ) سواء كانوا مستثمرين او مقرضين او هيئات حكومية حيث يجب اعدادها بطريقة اكثر شفافية و بدون تحيز لجهة دون اخرى ،هدفت الدراسة الى التعرف على اهم الفروقات الضريبية المؤجلة التي تنشأ في الوحدات الا
... Show MoreCompression for color image is now necessary for transmission and storage in the data bases since the color gives a pleasing nature and natural for any object, so three composite techniques based color image compression is implemented to achieve image with high compression, no loss in original image, better performance and good image quality. These techniques are composite stationary wavelet technique (S), composite wavelet technique (W) and composite multi-wavelet technique (M). For the high energy sub-band of the 3 rd level of each composite transform in each composite technique, the compression parameters are calculated. The best composite transform among the 27 types is the three levels of multi-wavelet transform (MMM) in M technique wh
... Show Moreأدوات الىفي الذاخلة على الجملة التحويلية الاسمي
التكتلات الاقتصادية العالمية وانعكاساتها على الدول النامية
Autonomous motion planning is important area of robotics research. This type of planning relieves human operator from tedious job of motion planning. This reduces the possibility of human error and increase efficiency of whole process.
This research presents a new algorithm to plan path for autonomous mobile robot based on image processing techniques by using wireless camera that provides the desired image for the unknown environment . The proposed algorithm is applied on this image to obtain a optimal path for the robot. It is based on the observation and analysis of the obstacles that lying in the straight path between the start and the goal point by detecting these obstacles, analyzing and studying their shapes, positions and
... Show MoreEpistemological skepticism was present strongly in the Islamic
philosophical heritage. Many texts were received by thinkers and
philosophers calling for
In pre- Islamic poetry, there are a lot of words that indicate
peacefulness of one sort of another, in addition to the inspirations of semantic
modeling in which the poet sets himself in various horizons.
Among these words: brother, comrade, friend, companion, lover,
people, prince, home, land, country, blessing, honesty, contract, company,
justice, thankfulness, forgiveness, pardoning, guest, goodness, faithfulness,
silence, death, peace,….
In addition, there are their derivatives from various aspects that indicate
peacefulness either directly or indirectly.
يهدف البحث إلى دراسة التحفظات على اتفاقية سيداو (الدول العربية أنموذجًا)، حيث يُعد نظام التحفظ على الاتفاقيات الدولية أحد المظاهر القانونية الحديثة في مجال العلاقات الدولية، والذي يقرّ بحق الدول في إبداء التحفظ على بعض أحكام الاتفاقيات الدولية، وفقًا للأحكام العامة التي حددتها المواد (19-23) من اتفاقية فيينا لقانون المعاهدات لعام 1969. وإذا كان حق الدول في التحفظ مكفولًا دوليًا، فإن الإشكالية القانونية تكمن في
... Show MoreIn this research the subject of human ability to change, as it is proven in the Koran , which is proof of the argument against the ability of human change , whether the change in the positive or negative direction .
Here the limits of the research are limited to a study of analysis of human ability to change and this establishes the important of knowing that man has the ability while in the wrong way to change the path to the right path which Gifts and guidance .
The search required three demands and conclusion
- The first required :- is to try the idolaters to take out believers by right .
- The second required :- is to change what is inside the soul as a reason to enter blessings on man .
- The third required :- is good