Unlike welding, soldering does not involve melting the work pieces. Soldering is a process in which two or more items are joined together by melting and putting a filler metal (solder) into the joint. Failure in the solder joint may make the system components lose their functions. Electrical wiring and electronic components are joined to devices and printed circuit boards using soldering. Soldering and brazing are both used in the assembly of musical instruments. Lead-tin alloy solder employed in the current investigation which has a diameter of 4 mm and a density of 11.0103 kg/m3 with continuous heat flux heating from the domain's left side and complete insulation on the other side. The melting of PCM was simulated using the ANSYS (Fluent) melting model. Three procedures were followed during the heating stage of the reflow process to perform the melting heat-transfer analysis. The simulation's results were recorded at regular intervals of 15 seconds. The results show melting rate increases as time proceeds. It is almost the same at the initial stages and increases in the middle and the end of the melting process. Heat transfer happens mostly through conduction during the first 0–30 seconds of the melting process, changing to natural convection as the material continues to heat up.
Abstract
This research aims to examine the correlation and the influence of Authentic Leadership on the contextual performance as a dependent variable, in the departments and Division of the iraqi Ministry of Foreign Affairs To try out with a number of recommendations that contribute to raising the level of contextual performance in the Ministry. Starting from the importance of research in public organizations and its Role in society, the researcher adopted the descriptive analytical approach in accomplishing this research, The 99 people responded exclusively comprehensively, based on questionnaire that is include 28-item, using interviews and field observations as
... Show MoreThe treatment of migraine headache targets the neurovascular mechanism and involves the use of serotonin receptor antagonists. Some of these drugs are used for the treatment of acute attacks; while others are effective as prophylactic measures to decrease the duration and frequency of attacks. Pizotifen, a 5-HTA antagonist, is one of the prophylactic drugs for which the clinical use resulted in low outcomes in reducing migraine symptoms. Melatonin, a serotonin derived neurohormone, was reported to exert many functions like sleep induction, anti-inflammatory, neurovascular regulation, cytoprotection and modulation of neurotransmitter release. In the view of the involvement of serotonin in the pathophysiology of migraine a
... Show MoreIn this study, Laser Shock Peening (LSP) effect on the polymeric composite materials has been investigated experimentally. Polymeric composite materials are widely used because they are easy to fabricate and have many attractive features. Unsaturated polyester resin as a matrix was selected and Aluminum powder with micro particles as a reinforcement material was used with different volume fraction (2.5%, 5% and 7.5%). Hand lay-up process was used for preparation the composites. Fatigue test with constant amplitude with stress ratio (R =-1) was carried out before and after LSP process with two levels of energy (1Joule and 2Joule). The result showed an increase in the endurance strength of 25.448% at 7.5% volume fraction when peened is 1J
... Show MoreIn this work, chemical and thermal treatment were used to enhance silica extract on the purity of rice husk and to reduce the impurities associated with the extraction of silica. The thermal degradation of rice husk was studied. The characteristics and thermal degradation behavior of rice husk which investigated using thermogravimetric analyzer (TGA). Hydrochloric acid was used to soak the rice husk and the study of leaching influence is followed by XRF tests for samples before and after the combustion process. Acid treatment and combustion method seem to have a clear effect on silica purity. The pyrolysis processes were carried out at Laboratory temperature up to 650 oC in the presence of nitrogen gas flowing at 150 ml/min. The effect o
... Show MoreThis study aimed to identify the effect of resistance training on the biomechanics and accuracy of serve receiving skills in volleyball. The research community was composed of 26 young volleyball players of Baghdad volleyball clubs. A total of 4 players were selected for the preliminary experiment, while 14 participants were recruited as the main sample for the study. In the present study, a set of resistance exercises were designed by the researchers for the volleyball players of the sample. Exercises were performed by the sample participants during the course of study. The biomechanical variables considered in the present study were: Preparation moment (shoulder joint angle, hip angle, knee joint angle), moment of pr
... Show MoreIrinotecan induced-mucositis is an inflammatory event of intestine caused by an increase in concentration of active metabolite 7ethyl10-hydroxycamptothecin (SN38) in the intestine. Irinotecan must first be converted by a carboxylesterase (CES) to the active metabolite (SN38), which is subsequently glucuronidated by the hepatic enzyme to SN38G. The SN-38G is deconjugated in the intestine to SN-38 via ?-glucuronidase produced by the intestinal bacterial flora, which accounts for SN-38 delayed intestinal mucositis of irinotecan. To study the protective effect of mentha in irinotecan-induced mucositis, intestinal mucositis induced by I.P injection of irinotecan (75mg/Kg/day) for 4 days. Mentha ethanolic extract orally administered to
... Show MoreBackground: Cyclin D1 proto-oncogene is an important regulator of (G1 to S) phase progression in many different cell types. The Aims of this study were to evaluate the immunohistochemical expression of Cyclin D1 in mucoepidermoid and adenoid cystic carcinoma of the salivary glands and to correlate the immunoexpression of this protein with the clinicopathological findings. Materials and methods Retrospectively, twelve of archival formalin fixed paraffin embedded tissue samples of salivary Mucoepidermoid and fourteen blocks of adenoid cystic carcinomas obtained from the archives of the department of oral pathology / college of dentistry / Baghdad university, Al-Shaheed Ghazi hospital, were included in this study. Five micrometer sections o
... Show MoreFluoxetine (FX) is an antidepressant drug administered only orally in humans. Despite the wide use of FX, until now, there is only limited literature concerning the pharmacokinetics (PK) of FX and the effect of food on its PK. Thus, the objective of this investigation was to study the PK of FX in Arabic healthy male adult volunteers under fasting and fed conditions. In the fasting study, FX 20 mg capsules (Prozac®, Eli Lilly, Canada) were administered to 41 volunteers after overnight fasting of 12 hours, followed by blood sampling from each volunteer immediately before dosing (zero time) and then at 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 24, 36, 48, 60, 72, 96, 120, and eventually at 144 hours after FX dosing. The fed study was conduct
... Show MoreBackground: Severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is still a severe threaft for human health currently, and the researches about it is a focus topic worldwide.
Aim of the study: In this study, we will collect some laboratory results of the patients with coronavirus disease (COVID-19) to assess the function of liver, heart, kidney and even pancreas.
Subjects and Methods: Laboratory results of the patients with COVID-19 are collected. The biochemical indices are classified and used to assess the according function of liver, heart, kidney; meantime, and blood glucose is also observed and taken as an index to roughly evaluate pancreas.
Results: There were some in
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