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.
Cancer is one of the critical health concerns. Health authorities around the world have devoted great attention to cancer and cancer causing factors to achieve control against the increasing rate of cancer. Carcinogens are the most salient factors that are accused of causing a considerable rate of cancer cases. Scientists, in different fields of knowledge, keep warning people of the imminent attack of carcinogens which are surrounding people in the environment and may launch their attack at any moment. The present paper aims to investigate the linguistic construction of the imminent carcinogen attack in English and Arabic scientific discourse. Such an investigation contributes to enhancing the scientists’ awareness of the linguistic co
... Show MoreAlthough many technological improvements are occurring in power production worldwide, power plants in third world countries are still using old technologies that are causing thermal pollution to the water bodies. Power facilities that dump hot water into water bodies are damaging aquatic life. In the study, the impact of the Al Dora thermal power plant on a nearby stretch of Tigris River in Baghdad city was assessed by measuring the temperature of the disposed of hot water in various cross-sections of the selected stretch of Tigris River, including measuring the thermal mixing length. The measurements were conducted in winter, spring, and summer. For field measurements, it was found that the impact of recovery distances
... Show Moreيرمي الكتاب الى التعرّف على خصائص البحوث المنشورة في مجلة الأستاذ وبيان السمات والمكونات الأساسية للمجلة واعداد كشافات تراكمية متنوعة لها . وجاء الكتاب في خمسة مباحث تناول المبحث الاول الاطار العام للبحث ،وضمَّ مشكلة البحث وأهميته وأهدافه واجراءاته والدراسات السابقة ،وتناول المبحث الثاني الدراسة النظرية وضم التعريف بـكشافات الدوريات ،وبيان أهميتها والتعريف بـ كلية التربية /ابن رشد وبيان أهدافها ،ومن ثم ا
... Show Moreعلى الرغم من تحقق ثورة هائلة وطفرة نوعية في مجال تكنلوجيا الاتصالات في دول العالم الا ان بلدنا كان محروما من التمتع بهذه التقنيات الحديثة في ظل النظام السابق, وبعد سقوط النظام ووجود بحبوحة من الحرية، دخلت الكثير من هذه التقنيات الى العراق ومنها الموبايل والانترنيت وغيرها من وسائل الاتصال المتطورة.
ويقول (Smith & Fletcher, 2001) في كتابهما Inside Information
... Show MoreAddressed the problem of the research is marked (experimentation in caves fee) concept and its role in experimentation deviate Display Num formal charges caves. The search came in four sections: general framework for research and identified the research problem and the need for him. With an indication of the importance of his presence. Then specify the search for the goals of (revealed the nature and role of experimentation in determining the nature of Manifesting fee documented on the walls of caves), followed by the establishment of the three search limits (objectivity, the temporal and spatial) were then determine the terms related to the title. Then provide the theoretical framework and indicators that resulted from academic theorizi
... Show Moreسوسيولوجية "ثوارت" "الربيع العربي (دراسة تحليلية لفعل الثورات العربية)
God bestowed upon the Imams of the Ahl al-Bayt (peace be upon them) knowledge and wisdom, in addition to give them virtue as long as it was not given to anyone from the worlds. knowledge have been enriched from them that cause pride.
1-Objective:- Polyphenols are biochemical compounds with antioxidant activity against differences diseases related to Lipid peroxidation such as diabetes mellitus. Polyphenols distributed widely in medical plants, the aim of the study is to extract and analyze some polyphenolic compounds from grape seeds and examine their effects on (STZ) induced diabetic mice. 2-Methods:- In the present study , a group of polyphenols has been extracted from Iraq
... Show MoreIn this study, the effect of construction joints on the performance of reinforced concrete beams was experimentally investigated. Seven beam specimens, with dimensions of 200×100×1000 mm, were fabricated. The variables were considered including; the location and configuration of the joints. One beam was cast without a joint (Reference specimen), two specimens were fabricated with a one horizontal joint located either at tension, or compression zone. The fourth
beam had two horizontal joints placed at tension, and compression area. The remaining specimens were with one or two inclined joints positioned at the shear span or beam’s mid-span. The specimens were subjected to a monotonic central concentrated loading until the failure. T
Micro metal forming has an application potential in different industrial fields. Flexible tool-assisted sheet metal forming at micro scale is among the forming techniques that have increasingly attracted wide attention of researchers. This forming process is a suitable technique for producing micro components because of its inexpensive process, high quality products and relatively high production rate. This study presents a novel micro deep drawing technique through using floating ring as an assistant die with flexible pad as a main die. The floating ring designed with specified geometry is located between the process workpiece and the rubber pad. The function of the floating ring in this work is to produce SS304 micro cups with profile
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