This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.
In this study, the researcher aims to analyze the content of the physics textbook for the 3rd intermediate grade according to the criteria for designing and producing infographics, and the research community consists of the content of the physics textbook for the 3rd intermediate grade intermediate grade for the academic year 2021-2022. The researcher adopted the analysis instruments with a number of the criteria for designing and producing infographics. The results revealed randomness in the percentage of the criteria included in the content of the physics textbook for the 3rd intermediate grade, and they are not compatible with the proposed criteria by the experts also.
The aim of this scientific study is to diagnose the nature of the relationship between academic education in the field of media, communication and media practice. The university offers theoretical and practical lessons to students on the concepts of communication sciences, theories, models, legislations, ethics, and techniques over three years or more. And the diploma in the field of communication and Media Sciences gives students the opportunity to work in the field of journalism and media in the future, this is what many academics and media thinkers in Algeria believe, while another trend sees the exact opposite: The study of information and communication sciences within the university in the form of theoretical lessons cannot contribu
... Show MoreIn the age of information and communication revolution, education as one of life aspects has influenced with that revolution by integrating technology in education, which have become as an important learning tools of the whole educational process . Technology, when used appropriately, can help make science classroom a site of active learning and critical thinking, furthering student inquiry and connections with different materials. It is necessary to develop human rights education programs and materials for discretionary and extracurricular activities as it provide them with the skills and tools so that they are empowered to take action to realize their rights. Human rights education is a critical means of instilling the knowledge، skil
... Show MoreMunicipalities.
Abstract
The purpose of this research is to measure the impact of regulatory flexibility dimensions (formal and authoritarian procedures) to achieve response to the requirements of high performance dimensions (the effective recruitment, intensive training, motivate employees, participation of workers) in the general municipal Directorate as one of the directorates of the Ministry of Municipalities and Public Works. For the purpose of this measure it has been selected sample composed of 88 individuals from the research community represents the levels of assistant general manager of department heads and managers of people and some of the staff to answer the questionnaire prepared for the purpose Hama
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Summary
The book (Fatah al-Rahman reveals what is ambiguous in the Qur’an), which is a book of verbal similarities that tries to touch the Qur’an expression, and the subtle differences between its expressions and expressions. It appeared when it appeared in many chapters, from which I chose to delete in monolithic letters such as Ba and Ta, and to heal and delete in non-monosymbols such as (that) and (may) and (no), so the search came to two chapters The first is for deleting the monolithic letters, and the second is for deleting non-monosyllabic letters, preceded by introductory discussions revolving around the linguistic and idiomatic definition of deletion, a brief translation of the
... Show MorePraise be to God, Lord of the worlds, and peace and blessings be upon our master Muhammad, and upon his family and companions as a whole. Now, the research deals with the grammatical issues mentioned in the Book of Al-Zahir in the meanings of people's words to Abu Bakr Al-Anbari (d. 328 AH). Two parts of the book have more than one edition, it was printed by the Iraqi Ministry of Culture and Information Beirut in 1979 AD, and the Al-Resala Foundation issued the second edition in 1992 AD The third edition was printed in Dar Al-Bashaer in Damascus in the year 2003 AD and it was the reliance on the research and the grammatical issues were arranged on topics that are: interrogation - Deletion, exclusion, marbling, call and Wallace Relief and
... Show MoreTime series is an important statistical method adopted in the analysis of phenomena, practices, and events in all areas during specific time periods and predict future values contribute to give a rough estimate of the status of the study, so the study aimed to adopt the ARIMA models to forecast the volume of cargo handled and achieved in four ports (Umm Qasr Port, Khor Al Zubair Port, Abu Flus Port, and Maqal Port(, Monthly data on the volume of cargo handled for the years (2006-2018) were collected (156) observations. The study found that the most efficient model is ARIMA (1,1,1).
The volume of go
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Background: Osteoporosis is a systemic skeletal disorder that has an impact on general health, dental health and salivary composition. The mineralization of teeth happens simultaneously with that of the skeleton, but if mineral metabolism is disrupted, tooth failures will resemble those that affect bone tissue. Vitamin D plays a key role in bone and tooth mineralization.
Objective: to evaluate the impact of osteoporosis on teeth decay in relation to salivary vitamin D among menopause in Baghdad city.
Subjects and Methods: This study was cross sectional study. The study group consists of
... Show MoreThe research aims at identifying the extent to which the top management in the organization is interested in managing the talents of its employees, through which it can face the competing organizations, as well as the great challenges faced by all organizations in recent years. The task of attracting and maintaining talented human resources is one of the biggest challenges facing Organizations
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