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.
This research reveals the treatment mechanisms followed in the media for covering the topic of displacement and captivity of Yazidi in the Iraqi press, through studying all the publishing in one of the Iraqi newspapers concerning the research subject. The research problem is in the following questions:
- What are the journalistic arts that are tackled by the newspaper concerning the subject of the Yazidi women?
- What are the editing forms for the model of the press subjects that have been employed about the event and what are its sources?
- What are the highlighting means used in presenting the subjects within the journalistic arts?
- What are the i
This study was carried out in epidemically field with common reed (Phragmites communis Trin.) plants in the Nassiriah cityThiQur governorate ,during 2009/2010 to investigate the influence of plant growth regulator gibberellin (GA3)and cytokinin (CK) in increasing the efficacy of glyphosate and Fluazifop-butyl in common reed control . Factorial experiment in RCBD was used with three replications in tow Factors . Glyphosate 3500mg .l־¹ gave the higher mean of injury score of common reed and lower mean of common reed shoots , shoots dry weight and rhizome dry weight(3.59,22.01 shoot /0.5m² ,0.57Kg / 0.5m² and 250.50gm /0,5m² ),respectively. All plant growth regulators gaves the higher means of common reed shoots and rhizome dry weight com
... Show MoreComparative Study Between Glimepiride and Glibenclamide in the Treatment of Type 2 Diabetic Patients in Al-Yarmouk Hospital
Modern American elegy reveals a change in the attitude of mourning from the traditional lamenting approach to some antielegiac attitudes towards the mourned figure. Many American poets have lamented the pass away of the stately figure of the father. However, some poets attack their dead father, and ridiculed him in a poem that is intended to be an elegy, instead of showing passion, homage and love to him. In this regard, two poetic attitudes to the father can be traced in modern American poetry. The first one takes the form of tributes and praise, offering great admiration, compassion, and love for the father. For these poets, a father is an inspiration. The second voice develops some anger and contempt against the patriarchal authority emb
... Show MoreThe research aims to shed light on the role of artificial intelligence in achieving Ambidexterity performance, as banks work to take advantage of modern technologies, artificial intelligence is an innovation that is expected to have a long-term impact, as well as banks can improve the quality of their services and analyze data to ensure that customers' future needs are understood. . The Bank of Baghdad and the Middle East Bank were chosen as a community for the study because they had a role in the economic development of the country as well as their active role in the banking market. A sample of department managers was highlighted in collecting data and extracting results based on the checklist, which is the main tool for the stu
... Show MorePoisoning with toxic substances accidently or deliberately can be life threatening and especially in some countries that lack the essential tests and facilities to identify the types and causes of these toxic substances. In Iraq, as many other countries, poisoning is one of the chronic public health problems. However, very little literature about the pattern of poisoning cases, types and age is available in Duhok Governorate. Therefore, this study was conducted to determine the most common patterns of poisoning and the related age and gender in Duhok Governorate from 2016-2018, which would possibly contribute to the early diagnosis and treatment of poisoning. The present study was conducted for three years, started from 1st of
... Show MoreBackground: Mitral regurgitation (MR) is the most commonly encountered valve lesion in modern clinical practice. Severe mitral regurgitation may cause systolic dysfunction. Left ventricular ejection fraction may not be an accurate measurement of LV function in patients with mitral insufficiency. Myocardial performance index (MPI) is a simple non invasive measure of myocardial function. Methods: The study involved 50 patients with valvular mitral regurgitation and 50 healthy subjects as a control group. Transthoracic echocardiography was carried out for all patients and control group. The echocardiographic measurements included left ventricular end diastolic and end systolic dimensions, left atrial diameter, ejection fraction (EF), and myoca
... Show MoreMost studies indicated that the values of atmospheric variables have changed from their general rates due to pollution or global warming etc. Hence, the research indicates the changes of direct solar radiation values over a whole century i.e. from 1900 to 2000 depending on registered data for four cities, namely (Mosul - Baghdad - Rutba - Basra. Moreover, attemptsto correlate the direct solar radiation with the temperature values have been recorded over that period. The results showed that there is a decreasing pattern of radiation quantities over time throughout the study period, where the value of direct radiation over the city of Baghdad 5550 w/m2 was recorded in the year 1900, but this ratio decreased cle
... Show MoreThe experiments were conducted in laboratory conditions of a temperature of 25± 2C and relative moisture of 40± 5 % to evaluate the effectiveness of the cinnamon, lavender and clove essential oils on some biological life aspects of cowpea beetle, C. maculates. Results of the obligative experiment for the effect of the oils on insect adult killing showed that the concentration of 5% caused a mortality percentage averaged 13.33% of the insect males. The mortality percentage of the insect females was 11.3% for the cinnamon and lavender oils. The lavender oil had the lowest effect on adult killing, not exceeding 0. For the effect of the oils on egg laying, clove oil affected the number of eggs highly at the concentration of 5%, result
... Show MoreThe investment decision, a critical decision for each investor as it involves risks and uncertain returns, so investors should avoid cases of uncertainty associated with the final decisions they are involved, and the problem of research in individual differences and differences in the behavior of individual investors and reflect the impact of this investment decision in the Iraqi market for securities. Therefore, the research aims to understand and analyze the impact of determinants of investor behavior as an independent variable in investment decision-making as a dependent variable in the Iraqi market for securities, and the research started from two main hypotheses to explore the influence and correlation between research varia
... Show More