The aerodynamic and elastic forces may cause an oscillation of the structure such as the high frequency of the airfoil surfaces and the dynamic instability occurring in an aircraft in flight and failure may occur at a speed called flutter speed. In this work, analytical and numerical investigations of flutter limits of thin plates have been carried out. The flutter speed of rectangular plates were obtained and compared with some published results. Different design parameters were investigated such as aspect ratio, thickness and their effects on flutter velocity. It was found that the structural mode shape plays an important role in the determination of the flutter speed and the coupling between the bending and torsional mode is the main cause of flutter.
يهدف البحث الحالي إلى دراسة تأثير المناخ التنظيمي لشعب الرياضة المدرسية في اقسام الانشطة الرياضية على مدرسي التربية الرياضية لأهمية المناخ التنظيمي لما يمثله من الخصائص والسلوكيات التي يتأثر بها العاملون التي قد تتباين من مكان لآخر والبيئة الجغرافية وثقافتها النوعية وذلك باستخدام المنهج الوصفي ولتتحقق من خلال الدراسة الميدانية, يتمثل مجتمع البحث الحالي من مدرسي التربية الرياضية في مدارس محافظة بغداد وال
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درست بعض خصائص عامل الالتصاق (تلزن) بكتريا Enterococcus faecalis EM1 مع خميرةSaccharomyces cerevisiae , اذ تم تعريض خلايا البكتريا لظروف مختلفة تضمنت درجات حرارة وارقام هيدروجينية وتراكيز من كلوريد الصديوم ومضادات حياة مختلفة.
The movement and broadening of foreign and European words into Persian is a topic within historical linguistics. Such changes are semantic, phonological
Since many of these European loanwords into Persian took a remarkable space within Persian dictionaries, and became an indispensible part of the language, a study of the original languages of these loanwords may identify the enormous effect of those languages upon Persian, being a receptor language, and may refer to the liveliness.
Among the important factors which helped the movement of various loanwords into Persian are:
- Geographical: this is seen via contact between Persian people and those neighboring people, specifically those speaking Ara
Constitutional Review of 1992 and 1996 and the role of the Party of Progress and Socialism
Iraq is Suffering nowadays from the criminal triad represented by the fiscal and administrative corruption, money laundering and terrorism, which are intertwined in a very related relations, as each of them support the other . Since the over growth has been one of its characteristics leaving behind a very dangerous negative effects whether it was social , economic or even political impacts . As a result , this trial is now represents a high risk that threatens the present and the future of Iraq . On the political , economic and social level , it is well to mention that the poor direct investment , the increasing rates of poverty , unemployment , inflation as well as the smuggling of goreign currency an
... Show MoreMS Elias, RGM AL-helfy, Plant Archives, 2019
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Aluminum oxide (ALO) was grafted by acrylic acid monomer (AlO-AM) and then, it was polymerized to produce alumina grafted poly(acrylic acid) (AlO-AP). The prepared AlO-AM and AlO-AP were characterized by Fourier-transform infrared, differential scanning calorimetry , thermogravemetric analyzer and particle size distribution. Adsorption equilibrium isotherms, adsorption kinetics and thermodynamic studies of the batch adsorption process were used to examine the fundamental adsorption properties of phenol (P) and p-chlorophenol (PCP). The experimental equilibrium adsorption data were analyzed by three widely used two-parameters Langmuir, Freundlich and DubininRadushkevich isotherms. The maximum P and PCP adsorption capacities based on t
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In this work, the preparation of some new oxazolidine and thiazolidine derivatives has been conducted. This was done over two steps; the first step included the synthesis of Schiff bases A1-A5 in 72-88% yields by the condensation of isonicotinic acid hydrazide and aldehydes. The second step includes the cyclization of derivatives A1-A5 with glycolic acid and thioglycolic acid to obtain the desired products, oxazolidine derivatives B1-B5 (44-60% yields) and thiazolidine derivatives C1-C5 (41-61% yields), respectively. The structure of the prepared compounds was characterized using FT-IR, 1H NMR, and 13C NMR spectroscopy. Some of the produced compounds were tested for antioxidant properties.