Flutter is a phenomenon resulting from the interaction between aerodynamic and structural dynamic forces and may lead to a destructive instability. The aerodynamic forces on an oscillating airfoil combination of two independent degrees of freedom have been determined. The problem resolves itself into the solution of certain definite integrals, which have been identified as Theodorsen functions. The theory, being based on potential flow and the Kutta condition, is fundamentally equivalent to the conventional wing-ection theory relating to the steady case. The mechanism of aerodynamic instability has been analyzed in detail. An exact solution, involving potential flow and the adoption of the Kutta condition, has been analyzed in detail. The solution is of a simple form and
is expressed by means of an auxiliary parameter K. The use of finite element modeling technique and unsteady aerodynamic modeling with the V-G method for flutter speed prediction was used on a fixed rectangular and tapered wing to determine the flutter speed boundaries. To build the wing the Ansys 5.4 program was used and the extract values were substituted in the Matlab program which is designed to determine the flutter speed and then predicted the various effects on flutter speed. The program gave us approximately identical results to the results of the referred researches. The following wing design parameters were investigated skin shell thickness, material properties, cross section area for beams, and changing altitude. Results of these calculations indicate that structural mode shape variation plays a significant role in the determination of wing flutter boundary.
Since the beginning of the second decade of the twenty-first century, Saudi Arabia tried to pursue an open foreign policy towards many countries in the Horn of Africa, especially with Ethiopia and Somalia, due to the geostrategic qualities that these two countries possess.Despite the development of Saudi foreign policy towards Ethiopia and Somalia, it was soon affected by the tension after the events that the Gulf states went through, that is, the Qatari crisis with Saudi Arabia,especially after most of the countries of the Horn of Africa adhered to a policy of neutrality towards the Gulf-Gulf crisis.
Thus it is expected that despite the geographical proximity and the historical, economic and political relations between Saudi Ara
... Show MoreAlthough rare, coarctation of aorta is a treatable cause of hypertension, transcatheter dilatation by balloon with or without stent are a well-known treatment strategy
The scientific studies that deal with Herminutia (interpretation) as the art of reading the interpretation practiced by the recipient after his understanding of the literary texts and works of art that he sees or read them so that these readings to make the act of reading and allow him the opportunity to mature and rational reflection of each text or artistic work.
Based on this, the researchers considered the establishment of the problem of their research through the search for the problematic overlap of concepts in the interpretive practices of the literary text?
The second chapter dealt with the definition of the term interpretation as well as interpretation as a theory and concept, and then the indicators reached by t
... Show MoreBackground: Acute myocardial infarction (AMI) is one of the most common diagnoses in hospitalized patients. Increased plasma hemostatic markers were noted in acute myocardial infarction, indicating that the blood coagulation system is highly activated in those patients. Aims of the study: To study the level of intrinsic coagulation factors including (FVIII:C, FIX:C ,FXI:C ,FXII:C ) in patients with acute myocardial infarction. Type of the study: Cross –sectional study. Methods: Thirty patients (their age range is 48-68 years) were included in this study (9 female, 21 male) who were just admitted to the coronary care unit in AL-Yarmouk Teaching Hospital and diagnosed as having acute myocardial infarction patients, blood samples were tak
... Show MoreKE Sharquie, AA Noaimi, AA Zeena, IOSR J Dent Med Sci, 2015 - Cited by 5
A representative sample of a thousand volunteer university students was screened for evidence of thalassemia minor.Complete blood counts using automated blood cell analysers and blood smears were examined. Patients having anemia, abnormal red cell indices or morphological features of thalassemia minor like hypochromia, microcytosis, target cells erythrocytosis and family history of thalassemia were then investigated for determination of HbA2 & HbF levels. Estimation of hemoglobin A2 was performed by micro-column chromatography while HbF was done using alkali denaturation. Seventy seven out of the thousand samples tested positive for thalassemia minor. They all showed a hemoglobin A
The present study include a new developed method of analysis for determination of drug Spironolaction (SP) in some Pharmaceuticals by Spectrofluorometric method. Spironolaction was determined under optimal experimental condition that follows :- The excitation spectrum was (l=351 nm), the emmetion spectrum was (l=518 nm), pH=1, the suitable temperature for reaction 60oC and the optimal time less than (3) minute. The analysis and rang statistical data was:-Linear dynamic rang (1-10) ?g.ml-1, the detection limit (D.L = 0.023 ?g.ml-1), Molar absorptivity (? = 29875 liter mole-1 cm-1), Relative standard deviation (%RSD = 0.78), (%Erel = 3.3) and recovery (Rec = 96.6) percentage. Determination of Spironolactone was accomplished by two methods
... Show MoreThe paper deals with the study of the sciences of the Qur’an according to the interpreter, Ayatollah Sayyid Mahmoud al-Talaqani, a religious jihadist figure from Iran. He is the author of the exegesis (Ishraq from Al-Quran), which consists of six parts, which he wrote inside the prisons of the Shah and in exile. Mr. Al-Talaqani agreed with some of the commentators in his positions on the sciences of the Qur’an, and some of them disagreed with others.