Finite element modeling of transient temperature distribution is used to understand physical phenomena occurring during the dwell (penetration) phase and moving of welding tool in friction stir welding (FSW) of 5mm plate made of 7020-T53 aluminum alloy at 1400rpm and 40mm/min.
Thermocouples are used in locations near to the pin and under shoulder surface to study the welding tool penetration in the workpiece in advance and retreate sides along welding line in three positions (penetrate (start welding) , mid, pullout (end welding)).
Numerical results of ANSYS 12.0 package are compared to experimental data including axial load measurements at different tool rotational speeds (710rpm.900rpm.1120rpm and 1400rpm) Based on the experimental records of transient temperature at several specific locations of thermocouples during the friction stir welding process the temperatures are higher on the advancing side (629.2 oK) than the retreating side (605 oK) along welding line and temperature in the top of workpiece under tool shoulder is higher(645 oK) than bottom (635.79oK). The results of the simulation are in good agreement with that of experimental results. The peak temperature obtained was 70% of the melting point of parent metal.
Abstract
The aim of the research is to clarify the requirements of the qualification of the external auditor in Iraq and the extent of their impact on the quality of the professional performance of the audit process. The research was based on analyzing the results of the questionnaire prepared for the impact of qualifications on the quality of professional performance. The researcher has reached a number of conclusions, the most important of which is that a highly qualified and unethical auditor has a greater negative impact on the quality of professional performance than those with low qualifications. The most important recommendations of the research were the need to pay
... Show MoreThrough an experimental program of eighteen specimens presented in this paper, the bond strength between reinforcing bar and rubberized concrete was produced by adding waste tire rubber instead of natural aggregate. The fine and coarse aggregate was replaced in 0%, 25%, and 50% with the small pieces of a waste tire. Natural aggregate replacement ratio, rebar size, embedded rebar length, the rebar yield stress of rebar, cover, and concrete compressive strength were studied in this investigation. Ultimate bond stress, bond stress-slip response, and failure modes were presented. The experimental results reported that a reduction of 19% in bond strength was noticed in 50% replaced rubberized concrete compared with convention
... Show MoreIt is not long time since globalization has started along with knowledge economy and, communication media and technical information control on the world. As a result serious events appeared like failure in businesses, financial corruption and shortage of administration and control.
In spite of the great efforts held by international organizations and foundations to find organizational frames that adopt independence, que
... Show MoreThe 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 MoreThe current study aimed to identify the morphological description and branches of the bronchial tree and lung for the weasel
Cluster analysis (clustering) is mainly concerned with dividing a number of data elements into clusters. The paper applies this method to create a gathering of symmetrical government agencies with the aim to classify them and understand how far they are close to each other in terms of administrative and financial corruption by means of five variables representing the prevalent administrative and financial corruption in the state institutions. Cluster analysis has been applied to each of these variables to understand the extent to which these agencies are close to other in each of the cases related to the administrative and financial corruption.
ABSTRACT Background: Neuropilin 1(NRP1) is considered a novel non - tyrosine kinase co- receptor for the vascular endothelial growth factors (VEGF). First discovered on migrating neurons. NRP1is suggested to be up-regulated in cells of different types of cancer and implicated with advanced disease. The aim of this study was to investigate the variation in expression of NRP1 in oral, laryngeal and skin squamous cell carcinoma. Materials and methods: Tissue sections from 120 formalin fixed- paraffin embedded blocks histopathologically diagnosed as oral, laryngeal and skin SCC (40 blocks for each),immunohistohemically stained in immunoperoxidase method with monoclonal antibodies to NRP1, the localization of expression was examined and the res
... Show MoreThe main problem established by a discovery of a thyroid nodule is to discriminate between a benign and malignant lesion. Differential diagnosis between follicular thyroid cancer (FTC) and benign follicular thyroid adenoma (FTA) is a great challenge for even an experienced pathologist and requires special effort. A developing number of some encouraging IHC markers for the differential diagnosis of thyroid lesions have emerged, including, Hector Battifora mesothelial (HBME-1) and galectin-3 (Gal-3). There was significant positive correlation between Galectin-3 and HBME-1 in follicular carcinoma and follicular variant of papillary carcinoma (r= 0.380, P= 0.041) and (r= 0.315, P=0.047) respectively. There was no significant correlation between
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