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.
It is well known that sonography is not the first choice in detecting early breast tumors. Improving the resolution of breast sonographic image is the goal of many workers to make sonography a first choice examination as it is safe and easy procedure as well as cost effective. In this study, infrared light exposure of breast prior to ultrasound examination was implemented to see its effect on resolution of sonographic image. Results showed that significant improvement was obtained in 60% of cases.
This paper presents the results of experimental investigations to predict the bearing capacity of square footing on geogrid-reinforced loose sand by performing model tests. The effects of several parameters were studied in order to study the general behavior of improving the soil by using the geogrid. These parameters include the eccentricity value, depth of first layer of reinforcement, and vertical spacing of reinforcement layers. The results of the experimental work indicated that there was an optimum reinforcement embedment depth at which the bearing capacity was the highest when single-layer reinforcement was used. The increase of (z/B) (vertical spacing of reinforcement layer/width of footing) above 1.5 has no effect on the re
... Show MoreGiven the importance of increasing economic openness transport companies’ face various issues arising at present time, this required importing different types of goods with different means of transport. Therefore, these companies pay great attention to reducing total costs of transporting commodities by using numbers means of transport methods from their sources to the destinations. The majority of private companies do not acquire the knowledge of using operations research methods, especially transport models, through which the total costs can be reduced, resulting in the importance and need to solve such a problem. This research presents a proposed method for the sum of Total Costs (Tc) of rows and columns, in order to arrive at the init
... Show MoreBackground: Hemorrhoids are one of the most
common surgical conditions .Conventional
haemorrhoidectomy was the traditional operation for
the treatment of hemorrhoids. Other modalities of
treatment had been used as an alternative operations
including CO2 laser haemorrhoidectomy.
Objectives: To determine the outcome of treatment
of hemorrhoids by using CO2 laser
haemorrhoidectomy and its advantages over
conventional surgery
Methods: This is a retrospective comparative
interventional study of 1024 case of third degree
haemorhoids selected out of 1300 case of
hemorrhoids of different degrees, admitted to
ALKINDY, ALYERMOUK teaching hospitals and
ABD ALMAGEED private hospital, from May 1998
to J
It is well- known that the distinguished scholastic journal is a crucial cornerstone, which contributes to the scientific integrity of a particular academic institution. The establishment of the Al-Kindy College of Medicine (AKCM), University of Baghdad, in 1998 urged the need to issue Al-Kindy College Medical Journal (KCMJ).
In this study, two correlations are developed to calculate absolute rocks permeability from core samples tested by Gas Permeameter Apparatus. The first correlation can be applied if K g≤100, the second correlation can be applied if Kg>100. Sixty core samples having different permeabilities to give a wide range of values that necessary to achieve a correlation.
The developed correlation is easily applied and a quick method to avoid repeating the test at different pressure values. Only one pressure test is required to reach absolu
... Show MoreThe goal of this study is to build an application that can be used in difficult cases and sudden circumstances during the pandemic and post-disaster state, which can be the development of digital risk management and mitigating the difficult impact of the epidemic through the improvement of IT and IoT that can be fine by finding initial solutions and make the world like a digital city that could be managed by the network. We provide this study to gain an overview of reasons for delayed and exceeded costs in a select of thirty Iraqi case projects by controlling the time and cost. The drivers of delay have been investigated in multiple countries/contexts. however, there is little country data available under the conditions that have ch
... Show MoreIn order to activate theatrical discourse aware of the changes imposed by the nature of the contemporary child in terms of stimulating the social skills that achieve a technical and aesthetic convergence between him and theatrical presentation by investing the fact of the existence of the child and its potential in the weaving of stories, and folk in the imagination, and simulation of what corresponds with the characters and icons interact with them through technologies In the light of this research came the following address: (ways to stimulate the skills of the child through a contemporary theatrical speech) where the researcher seeks to delineate the importance involved in the discourse of theater through ways to reach the pillars con
... Show MoreThe research aims to identify the effect of applying administrative decentralization to an educational performance by assessing educational performance before and after the process of transferring powers from the federal government (the Iraqi Ministry of Education) to local governments (governorates) as well as identifying the appropriate central or decentralized administrative system to advance the educational reality and performance. To achieve the goal of the research, educational data was collected and analyzed, as well as the measurement of educational performance indicators and analysis during two phases, the first represents the stage of applying the central system and spanned between the academic year (2011-2012) and the
... Show MoreThe issue of freedom is the most prominent and distinctive issue of Western thought, which it reached after a long struggle. The English thinker John Stuart Mill is considered the most prominent Western thinker who elaborated on the issue of freedom, until his ideas on the issue of freedom became the semi-final formula for issues of freedom in Western thought, which revolve in their entirety on The individual has complete freedom as long as it does not harm others, and this freedom is controlled by law.
And if the freedoms he offered were not considered an achievement in Western thought; Freedom in Islam is a central and fundamental issue, and the details of freedoms in Islam have not been accomplished by anyone, but rather came
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