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.
The research aimed to identify the effectiveness of instructional design according to whole brain theory of Herman in the achievement of chemistry at the fifth scientific students at a secondary school of the General Directorate for Educational in Diyala / Baladruz in Iraq. The research sample Consisted of (57 student, (29) students as experimental group studied according to instructional design strategies for whole brain theory of Herrmann and (28) a student as a control group studied by the usual way for two semesters, a prepared achievement test as article and objective type of multiple choice, the coefficient stability of alpha-Cronbach equation reached (0.86). The research Results showed the presence of a statistically significant d
... Show MoreThe dependence of the energy losses or the stopping power for the energies and the related penetrating factor are arrive by using a theoretical approximation models. in this work we reach a compatible agreement between our results and the corresponding experimental results.
Vulvovaginal candidiasis (VVC) is caused by Candida albicans affects a significant number of women during their reproductive ages. Th17 cells play a major role in coordinating the host defense in oropharyngeal candidiasis. In this study we investigated the involvement of the Th17 response in an animal model of vulvovaginal candidiasis (VVC). The present study aimed to shed light on detect concentration of the IL-17 of infected animal and control . A direct Enzyme Linked Immunosorbent Assay (ELISA) was used to quantify IL-17 concentrations in 30 infected animal with VVC and 10 control group. Rats were intravaginally inoculated with C.albicans, and vaginal lavage fluids, serum were evaluated for proinflammatory cytokine IL-17 The data
... Show MoreBackground: Nutrition and diet can affect the development and integrity of the oral cavity including the development and eruption of primary teeth. Aims of the study: The study was carried out to determine the effect of weight status of the child and gender on the number of deciduous teeth erupted in the oral cavity. Material and method: A children from the age 12 months -35 months attending Specialist Health Center and children of Nursery in Al-Khadraa, and nursery in Al- Aadamyia and Hay-Heteen. The number of teeth erupted, gender and body mass index were recorded. Results: The results showed that eruption of primary dentition was quicker in children who were overweight than those with normal weight and underweight and faster in girls
... Show MoreBackground: Iraqis were exposed to wars, widespread violence and civil war. Post-traumatic stress disorder develops after exposure to trauma and violence. It has a negative effect on academic achievement of the students.
Objective: This report was carried out to study the effect of exposure to violence on academic achievement of youths in Iraq.
Methods: A total of 319 university students from Baghdad were included in the study. Their age ranged between 18 and 24 years with male to female ratio of 0.6:1. A questionnaire was filled for each participant. Requested data were demographic information, data on school achievement and Harvard Trauma questionnaire (exposure to war trauma, posttraumatic stress disorder “PTSD”). Chi square
Drag reduction (DR) techniques are used to improve the flow by spare the flow energy. The applications of DR are conduits in oil pipelines, oil well operations and flood water disposal, many techniques for drag reduction are used. One of these techniques is microbubbles. In this work, reduce of drag percent occurs by using a small bubbles of air pumped in the fluid transported. Gasoil is used as liquid transporting in the pipelines and air pumped as microbubbles. This study shows that the maximum value of drag reduction is 25.11%.
Research summary
Muslim scholars have established fundamental rules for deriving rulings to be a methodology for every mujtahid who wants to extract rulings from his reliable sources, and one of the most prominent fundamental rules on which many rulings are built is the permissible and the many rulings related to it.
Leaving what is permissible on its own terms sometimes causes embarrassment and distress in some cases, so we need something that restricts it. In our Islamic law, many legal rulings are embodied in which the restriction of what is permissible is in the public interest, or to relieve embarrassment in public.
Because of the importance of this fundamentalist rule, and the difference in some
... Show MoreConstructal theory plays a major role in the conceptual design stage of the structural system in architecture. It provides a conceptual framework for predicting the form depending on natural systems to model those systems geometrically according to the constructal law that works in two directions: the first is towards predicting the general form of the structural system, and the second is the physical application of the law in the process of detailed design of the parts of the system. The aim of this paper is to determine the mechanism adopted in the structural design according to the constructal theory, assuming that the structural design according to the constructal theory achieves
QJ Rashid, IH Abdul-Abbas, MR Younus, PalArch's Journal of Archaeology of Egypt/Egyptology, 2021 - Cited by 4
The aim of this study is to achieve the best distinguishing function of the variables which have common characteristics to distinguish between the groups in order to identify the situation of the governorates that suffer from the problem of deprivation. This allows the parties concerned and the regulatory authorities to intervene to take corrective measures. The main indicators of the deprivation index included (education, health, infrastructure, housing, protection) were based on 2010 data available in the Central Bureau of Statistics