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.
After the fall of the Soviet Union, a number of Eastern Bloc countries and Soviet republics have witnessed political transition. However, Turkmenistan, as one of the former Soviet republics, succeeded to preserve the authoritarian nature of the former Soviet regime. This study seeks to answer a number of research questions, the most prominent of which are: How were the political elite in Turkmenistan able to preserve the legacy of the Soviet policy based on centralization of power and individual rule?. The study reaches a set of conclusions, the most important of which are:
1-The roots of the tyranny in Turkmenistan are du to internal and external structural factors. The most important of which are: the former Soviet policies of m
... Show MoreThe US invasion of Iraq in 2003 unleashed the repressed national aspirations of the Kurdish people. After the colonial powers, especially Britain, failed to establish a homeland of scattered Kurds in Iraq, Turkey, Syria and Iran, Iraq's Kurds managed to establish a semi-independent state in the north of the country Which lasted decades against the central authority in Baghdad in protest against what they call the forced integration of Kurds in the Iraqi state, and to obtain more rights and privileges as partners in this country. The federal region in the Kurdistan region of Iraq has become a reality, and it is eager not to strengthen its authority in return for the authority of the central government, but to annex other areas inhabited b
... Show MoreSpace is considered as an important element in constructing artwork, it can be a dominant and fulfilled part that adds new existence to the content. Each artwork must have a space artistically or analytically. The internal and eternal space of artwork have associated with each other in order to be ann important connected unit that establishes the work epressions and helps the audience to understand it. Such kind of works can be represented by the works of the potter (Sheinyor Abdu Allah) which have uarious expressions of space which this study is based on.The study aims at finding out the treatment of apace in the ceramic sculpture works of the potter (Sheinyar Abdu Allah).The second chapter has many sections. T
... Show MoreBusiness Ethics play a major role in explaining the behavior of those interested in the management of tourism enterprises in the field of management gains, which sometimes turn to manipulation in the specification of the service of tourism and influence in the technical characteristics at the expense of the brand and market share, as well as misleading beneficiaries about the fact that the performance of the service of tourism, may depend activities tourist dramatically when submitting and sharing various services on the types of mutual relations the framework for moral distinct, in interaction or direct contact between producers of tourism services and tourists or their beneficiaries, in order to provide comfort and recreation a
... Show MoreIncreased the need to promote the profession of auditing, and improving the performance of the audit process, which comes through the effective implementation of its tasks, where the auditor collects the necessary data about the nature of client activity, and any other information it deems necessary to carry out the planning and development of the strategy for how to determine the procedures for implementing the audit process and the scope and timing for evidence clues in order to form an opinion technician neutral about the fairness of the financial statements, as required by the standards of the field work of the planning and supervision of the internal control and evidence to prove, but the failure of the auditor whether in th
... Show MoreEcosystems provide humans with services that include benefits from food, fresh water, climate regulation, and socio-economic assets. The Mesopotamian marshlands are among the largest wetlands in the Middle East and they provide various benefits. However, ecosystem services of the Marshlands are consistently undervalued in national economic analysis and decision making. This study focusses on the Central Marshes, the first National Park in Iraq, and is the first attempt at valuing a series of ecosystem services from a valuable natural ecosystem in Iraq. We adopted the Toolkit for Ecosystem Services Site-Based Assessment (TESSA) for the determination of biophysical and economic values of services at the site level. Data on key ecosystem se
... Show MoreBackground: Post-extraction alveolar ridge resorption is unavoidable phenomenon ending with insufficient ridge width. Measuring the physical dimensions of the available bone before implant surgery is an important aspect of diagnosis and treatment planning. Bone height can be calculated from radiographs, while bucco-lingual ridge width can be measured by conventional tomography, CT scanning and ridge mapping.
Radiographic techniques have certain disadvantages. Therefore the ridge mapping technique was used as an option for determining alveolar ridge width.
The purpose of this study was to compare the validity of alveolar ridge width measurements obtained with ridge mapping technique before surgical flap reflection against
... Show Morehe research specifies important subjects which contribute in improvement of productive performance in industrial companies through study and analysis of relationships and effect between dimensions of physical work environment and industrial operations flexibility in the leathers industries company. To reach these goals the information are collected is questionnaire prepared for this purpose as a tool to analyze the practical results and are recorded for a sample of 118 persons from employees. The research uses the statistical methods and analyzes the information by using SPSS system. The research reached to many conclusions; the important one is the weakness of the company to make in to account the physical envir
... Show More The integration of AI technologies is revolutionizing various aspects of the apparel and textile industry, from design and manufacturing to customer experience and sustainability. Through the use of artificial intelligence algorithms, workers in the apparel and textile industry can take advantage of a wealth of opportunities for innovation, efficiency and creativity.
The research aims to display the enormous potential of artificial intelligence in the clothing and textile industry through published articles related to the title of the research using the Google Scholar search engine. The research contributes to the development of the cultural thought of researchers, designers, merchants and the consumer with the importance of integ
The present study aims to test a range of hypotheses about the effectiveness of each of the theory of transactional leadership, and the theory of transformational leadership in the Egyptian environment, and to identify any of them are better able to predict the effectiveness of leadership. And after the effect will be to identify the quality of the relationship between the leader and the subordinate in leadership , and what is the role of transformational leadership dimensions influencing the effectiveness of leadership. The field study was conducted on a sample of companies' public and private sector and the government in Egypt. The results of the study resulted in experimental that transacti
... Show More