The first studies on shocks and vibrations were carried out at the beginning of the 1930s to improve the behavior of buildings during earthquakes. Vibration tests on aircraft were developed from 1940 to verify the resistance of parts and equipments prior to their first use. Flutter is a well-known example of dynamic aero elasticity, where when oscillation of structure interacted with unsteady aerodynamic forces the flutter will occur. Vibration on any structure without damping means that self-harmonic oscillation will occur, and in most cases the oscillation may start to increase until structural failure. This behavior is very similar to resonance phenomena if only the oscillation is being studied as a vibration case. In vibration suppression, the active vibration control is one of the more effective technique which is used for attenuating bad effects of disturbances on structure. In this work, two different composite wings have been used; one of them is made of Glass-fiber random matt and the other is made of woven ({0/90} Glass-fiber). The proportional-integral-derivative (PID) control is employed here for studying the suppression of active vibration wing affected by wind velocity flow through wind tunnel in the laboratory of mechanical engineering department at the university of Baghdad. Piezoelectric (PZT (transducers are used as sensors and actuators in vibration control systems. The attack angle was 10 degrees and three different velocities (15, 20, 35 m/s) have been taken to show their effect on the wings vibrations suppression. Is noticed that the suppression of the wing amplitude is reduced when the wind velocity increases for both woven and random composite wing matt. This is happened due to the vortex which has became more violent increase in wind velocity. It is concluded that the composite woven wing has high resistance more than the composite random wing. Also, the maximum control amplitude of woven matt is 1.9 cm and the damping is about 33% at 25 m/s wind velocity while the amplitude is 2.22 cm and the damping is about 53% at 10 m/s wind velocity for random wing.
Fetal growth restriction is a significant contributor to fetal morbidity and mortality. In addition, there are heightened maternal risks associated with surgical operations and their accompanying dangers. Monitoring fetal development is a crucial objective of prenatal care and effective methods for early diagnosis of Fetal growth restriction, allowing prompt management and timely intervention to improve the outcomes. Screening for Fetal growth restriction can be achieved via many modalities; it can be medical, biochemical, or radiological. Some recommended combining more than one for better outcomes. Currently, there is inconsistency about the best method of Fetal growth restriction screening. In this review, a comprehensive
... Show MoreDensity functional theory (DFT) calculations were used to evaluate the capability of Glutamine (Gln) and its derivative chemicals as inhibitors for the anti-corrosive behavior of iron. The current work is devoted to scrutinizing reactivity descriptors (both local and global) of Gln, two states of neutral and protonated. Also, the change of Gln upon the incorporation into dipeptides was investigated. Since the number of reaction centers has increased, an enhancement in dipeptides’ inhibitory effect was observed. Thus, the adsorption of small-scale peptides and glutamine amino acids on Fe surfaces (1 1 1) was performed, and characteristics such as adsorption energies and the configuration with the highest stability and lowest energy were ca
... Show MoreAutorías: Nuha Mohsin Dhahi, Muhammad Hamza Shihab. Localización: Revista iberoamericana de psicología del ejercicio y el deporte. Nº. 6, 2022. Artículo de Revista en Dialnet.
The research deals with the concept of rationalization of consumption, which is legitimately legitimized, by indicating the permissibility of consumption and its limits in Islam, the legitimate aspects of spending and its controls, and the concept of development in the Islamic economy. The researcher followed the descriptive method by presenting the legal texts and jurisprudential opinions and linking them to contemporary economic problems.The research has reached several conclusions, the most important of which is that the goal of Islam in relation to consumption is to inform the Muslim of the amount of economic maturity, and the truth of alms is good in money and religion. It is necessary for achieving maturity that both means
... Show MoreTwo molecular imprinted polymer (MIP) membranes for Levofloxacin (LEV) were prepared based on PVC matrix. The imprinted polymers were prepared by polymerization of styrene (STY) as monomer, N,N methylene di acrylamide as a cross linker ,benzoyl peroxide (BPO) as an initiator and levofloxacin as a template. Di methyl adepate (DMA) and acetophenone (AOPH) were used as plasticizers , the molecular imprinted membranes and the non molecular imprinted membranes were prepared. The slopes and detection limits of the liquid electrodes ranged from -21.96 – -19.38 mV/decade and 2×10-4M- 4×10-4M, and Its response time was around 1 minute, respectively. The liquid electrodes were packed with 0.1 M standar
... Show More،يريغت وأ ةلكشم وأ ةثداح ةجيتن ،ةعمالجا وأ درفلا هذختي فقوم هرهوج في ماعلا يأرلا دعي ةيوبرت تماكارتو ،ةيرثك تانوكم لىع هسسأ في موقي وهف اذل ،ةشاعلما ةايلحا تاقايس في لصيح فيو ،عمتمج يلأ يعماتجلاا لعفلا ةيصوصخ تاقايس بسحب يرسي ايرطف نوكي ام اهنم ،ةيفاقثو يعولا ةلاح تيبثت ديرت تاهج نم ةلعتفمو ةعنطصم تايطعمب اهيريست وأ اهذحش متي ىرخأ نايحأ ليكشت ةيلمع تنترقا ذل ،ةثدالحا كلت مهف ةأطو ليلقت وأ يريغت وأ فرح وأ ي
... Show MoreThe Internet, networks and the means of communication in the world of communication and information have greatly influenced all aspects of the information cycle until things have been turned upside down, and it has even been said that today the world can be separated into two worlds: the world of pre-internet and post-Internet.
Perhaps one of the most important data of the Internet in the world of information and journalism is electronic publishing, which comes blogging as one of its forms. Blogs, which have begun slowly in the form of personal diaries, developed and spread on the Internet very quickly and started to have its own universe, the world of blogging. It has begun to make its way in the world of journali
... Show Moreيتمثل الهدف الأساسي من الرقابة علىٰ تركز الشركات في منع آثارها المحتملة غير التنافسية الضارة بالهيكل التنافسي للسوق المعنية، وذلك لحماية حرية المنافسة فيها. وفي إطار ذلك لا بد من التحقق من أن تلك العمليات ليس من شأنها إعاقة المنافسة الفعّالة أو الحد منها بشكل كبير علىٰ نحو يترتب عليه التأثير علىٰ السوق المعنية بجعلها أقل قدرة علىٰ المنافسة مما كانت عليه، أي ضرورة التنبوء بكافة الآثار المحتملة التي ستترتب عل
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