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.
This study measured and analyzed job satisfaction among faculty members at the university of Irbid College in relation to gender social status, years of experience, academic rank , qualification, the population consisted of 110 full-time Jordanian factually members. A total of 72. (61%) factually, members participated in this study. The research instrument which was developed by the researcher consisted of tow parts: personal information and the job Satisfaction Questionnaire Frequencies, percentages, means and one-way analyses of variance were employed to analyze the data. The level of significance was set at 0.05. A Secheffe method of multiple comparisons was used for follow-up investigation.
... Show MoreThe use of silicon carbide is increasing significantly in the fields of research and technology. Topological indices enable data gathering on algebraic graphs and provide a mathematical framework for analyzing the chemical structural characteristics. In this paper, well-known degree-based topological indices are used to analyze the chemical structures of silicon carbides. To evaluate the features of various chemical or non-chemical networks, a variety of topological indices are defined. In this paper, a new concept related to the degree of the graph called "bi-distance" is introduced, which is used to calculate all the additive as well as multiplicative degree-based indices for the isomer of silicon carbide, Si2
... Show MoreThe audio-visual arts are considered modern arts compared to theater, plastic arts, and music. It proved its distinguished presences among other arts. It was capable of forming a huge audience and took television from cinema, literature, theater, type of narration, and narrative instructor. Also, it took symbolism and metaphorical repetition from literature. As for the importance of the functions that repetition has the research concentrated on the importance of function of repetition in deeping the esthetic meaning in television drama. The research was limited by:1.Objective limit: functions of repetition in deeping the esthetic meaning in series of (Harem Al-Sultan).2.Place where it was showed: series of (Harem Al-Sultan) part four on
... Show MorePlace is considered one of the important artistic elements in the movie through which the events occur in different arts and literatures and with its absence there isn’t any that can initiate events. Place is important for the things that we recognize, and the first fact in cinema is the place which can't be dispensed with on the level of the film or scene or cinematic shot that can't be emptied from its spatial content. The characters are always there in a place occupying some space of it, despite that it is not merely a container for the event cinematically. The researcher views the importance of discovering and observing them in this research which is divided into four chapters as follows: (theoretical framework) which includes the
... Show MoreObjective: Determine the effectiveness of the Nutrition Education Program upon the pregnant mothers'
nutritional knowledge.
Methodology: ٨ quazi-experimental study was carried out to determine the effectiveness of the nutrition
education program upon the pregnant mother's nutritional knowledge. A non-probability "purposive sample" of
(60) pregnant mother was selected from Al-bayaa' Primary Health Care Center in Baghdad City. These mothers
were divided into two equal groups; study group and control group. A questionnaire was developed as a tool of
data collection for the purpose of the study. A pilot study and follow-up was carried out to test the reliability and
validity of the questionnaire for the period of Octobe
The aim of the research is a techno-economic analysis of the use of concentrated solar energy technologies in the Iraqi city, considering the concentrated solar energy technology is a renewable energy technology that derives its resources from the sun and is replenished at a rate that exceeds its use. It is also inexhaustible and environmentally friendly energy from its environmental footprint, unlike traditional fossil energy which produces greenhouse gases and a major cause of global warming.
This research measures the costs of concentrated solar energy technology to Reduce the effects caused by other energies and work to fill part of the shortfall in the total electricity production, even at a specific percentage, in preparati
... Show MoreThe problem of the research is indicated by answering the following questions: 1) what are the attitudes of the Arabic language teachers towards homework?
2) Do the Arabic language teachers differ in their attitudes towards homework according to their specialization? 3) Do the Arabic language teachers differ in their attitudes towards homework according to their gender (male and female)? According to the three questions asked above, we may state the following hypotheses. There is no statistically significant difference between the average of the marks of Arabic language teachers in the real practice of the scale of the attitudes towards their homework and their average in the hypothetical practice of the
... Show Morethe present study is designed to evaluate the effect of low level laser irradiation on the immume system when administere intravenoisly
The comedian scenes which Shakespeare has entered in some of his tragedies(Hamlet, King Lear, and Macbeth), constantly the wrath of conservative critics and theorists of Western Drama, as big violation to Aristotle’s rules of tragedy that is forbidden to insert comedian scene in tragedy. Chapter one deals with the research problem, and its significance, purpose,Boarders and the definition of Comic Relieve. Chapter two comprises the theoretical framework which has displayed Arist-Otle’s conception about the imitation way of heroes characters between tragedy and comedy, the different function of catharsis in each one. Then the research has exposed the economical and theatrical activities in London during Elizabethan age which was looke
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