In this research the natural frequency of a cracked simple supported beam (the crack is in many places and in different depths) is investigated analytically, experimentally and numerically by ANSYS program, and the results are compared. The beam is made of iron with dimensions of L*W*H= (0.84*0.02* 0.02m), and density = 7680kg/m3, E=200Gpa. A comparison made between analytical results from ANSYS with experimental results, where the biggest error percentage is about (7.2 %) in crack position (42 cm) and (6 mm) depth. Between Rayleigh method with experimental results the biggest error percentage is about (6.4 %) for the same crack position and depth. From the error percentages it could be concluded that the Rayleigh method gives close results to experimental than ANSYS. Also it is found that the frequency of beam when the crack is in the middle position is less than the frequency with crack near the end position.
The objective of the research is to find the best method to estimate rice crop through out evaluating the applied methods of stratified random sampling .By using different sorts of sampling estimators, a comparison was held among the variances of the mean for simple random sampling, stratified random sampling(var()) and separate regression estimator. The results indicate that the separate regression estimator give best estimations. The approximate cum.f4/5 method was used to determine the optimum stratum boundaries, new strata was put and then var () was calculated .In comparison with strata used nowadays in central statistical organization, the new strata led to obvious decrease in the variance. The stratified mean wa
... Show More
Every era characterizes with its thought and life philosophy , where Muslims left behind them educational and intellectual heritage we should proud of it because it reflects the image of past and lights the way of present and future path where we should make use of it to fit with our statuesque and contemporary issues because we don’t know about it but little as result of ignorance or imitation of the western culture.
It’s wrong to regard heritage from the past but aphasia of Islamic and Arab genies that its roots tracing back to past and extending to future .
Islamic Arab educational thought regards one of the ric
... Show Moreيعد التأمين أحد المؤسسات المالية ذات التأثير على برامج التنمية ، وما زال قطاع التأمين يعاني من العديد من المشاكل منها الوعي أو التشريع أو كيفية توظيفه كمورد اقتصادي واجتماعي خدمة للمجتمع والمؤسسات والافراد. وحيث أن التأمين يقدم خدمة تستوجب التزامها بمواصفات محددة ، لذا أصبح من الضروري دراسة آليات تحسين جودة الخدمة التأمينية وكذلك دراسة واقع العملية التسويقية للخدمة التأمينية وما ينالها من تحديات داخلية أ
... Show MoreConsiders births illegal for children (illegitimate) phenomenon of negative social phenomena in our society where it's dangerous and the superiority of gravity on other social phenomena Calanhrav, homelessness and other due to poor drainage energies and sexual dysfunction in the value system among its actors and is characterized by the absence of social conscience and a lack of morality and the weakness of the system human-reliance among others.
The morality is the obvious difference between humans and animals. Wade this to say social scientists, while human social animal they said no that he has morals and values do not exist in other organisms so well that births
... Show Morethe boot of honesty in the dictionary the term linguistic and religious
heritage, literary and Islamic Sufi thought, and concept in the literature of Imam
Ali, peace is upon him. And studied the summary first concerns its presence in the
literature and implications and directions, either the second part, has cared for the
analytical study has found research that safe weight was the counterpart of the
personality of the Imam accompanied the character most prominent in his
character, namely, (courage), it has struggled to deliver a impact of humanity in his
time and after the word and deed, It was based on the imagination in the formation
of images sensual and intellectual, to his persuasion of the evidence and argu
Quran orders and commandments and principles, has avenged children, their status and dearest, and saved their lives, which reached ill before Islam, and filled the hearts of the fathers and mothers for their love, but to make them embellish life.