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.
Background: All diseases concerning bone destruction such as osteoporosis and periodontal diseases share common pattern in which the osteoclast cells are absolutely responsible for bone resorption that occurred when osteoclast activity exceeds osteoblast activity. Osteoprotegrin (OPG) considered as novel soluble decoy receptor known as “bone protector†since it prevents extreme bone resorption through inhibition of differentiation and activity of osteoclast by competing for binding site. It binds to receptor activator of nuclear factor kappa-B ligand (RANKL) and prevent its interaction with receptor activator of nuclear factor kappa-B (RANK), thus inhibits osteoclast formation. TNF-α is a pro-inflammatory cytokines having
... Show MoreApical periodontitis (AP) is the most prevalent chronic inflammatory disease of the teeth. Bone resorption dynamics in symptomatic and asymptomatic AP are still unrecognized. This study examined different inflammatory markers within gingival crevicular fluid, including matrix metalloproteinases 8 (MMP8), tissue inhibitors of metalloproteinases 1 (TIMP1), receptor activator of nuclear factor κB (RANK), its ligand (RANKL), and osteoprotegerin (OPG), to be used in comparing symptomatic apical periodontitis (SAP) and asymptomatic apical periodontitis (AAP) versus healthy teeth. Subjects with SAP, AAP, and a control group were recruited and GCF samples were collected by Periopaper strips. Clinical and radiographical measures were used f
... Show MoreBackground: Coronary artery disease (CAD) is a major contributor to morbidity and mortality worldwide. Early-onset CAD, also known as PCAD, is a severe form of CAD associated with high mortality and a poor prognosis. Early diagnosis is crucial to reducing complications. While hsCRP is an established biomarker for CAD, kalirin is a potential novel biomarker due to its role in promoting smooth muscle proliferation and endothelial dysfunction. Objective: To evaluate the relationship between serum kalirin and hsCRP levels with the presence and severity of PCAD and to compare the diagnostic value of both biomarkers. Method: The study recruited 92 participants into two groups: the PCAD group (46) included patients with confirmed CAD by an
... Show MoreThe pharmacokinetics and bioequivalence of a newly developed extended-released (ER) tablet containing 400 mg pentoxifylline as a test product was compared with the reference brand product Trental® 400 mg ER tablet produced by Sanofi-Aventis. Two separate studies were conducted simultaneously. The first study was conducted under fasting condition, whereas, the second study was conducted under fed condition; using the same batches of the test and reference products in both studies. In each study, both products were administered to 32 healthy male adult volunteers applying a single-dose, two-treatment, two-period, two-sequence, randomized crossover design with one-week washout period between dosing. Twenty two blood samples we
... Show MoreThe current study aims to investigate the effect of the interaction between the use of the improve strategy in teaching mathematics and the level of academic achievement on the acquisition of algebraic concepts and habits of mind among tenth-grade students in Oman. The study adopted the experimental method, based on a quasi-experimental design with two groups: experimental and control groups and pre-post-measurement. The study sample consisted of (28) 10th-grade students as an experimental group and 26 of 10th-grade students as a control group in Al-Tufail bin Amr School in South Al Batinah. The differences in the pretest and posttest gains were analyzed using mean, standard deviation, ANCOVA, t-test, effect size (eta-square), and two-wa
... Show MoreThis study research to Showing The impact of the integration process on the quality of Insurance service and analyze the impact financially to determine whether there is any impact on the quality of the insurance service, in addition to identifying the obstacles that impede the merger between the insurance companies, insurance and the appropriate proposals for its' application and benefit from the benefits achieved.
The importance of The study lies in the fact that it is an important and vital spotlight that is becoming increasingly important in the world to confront the various difficulties and crises that have occurred recently in light of the liberalization of international trade, globalization a
... Show MoreAphid Aphis spp (Hemiptera:Aphididae) and Thrips Thrips spp (Thysanoptera: Thripidae) an economically important pests on several crops in the world and Iraq, that transfer many viruses diseases to it. Field studies were conducted to assessment the population density of these insects and susceptibility of six varieties (Barin, Revera, Divela, Rudlph, Alazata and Pleny) to infestation during 2013 spring season. The results were showed that all Potato varieties were infested by Aphis and Thrips on spring plantation but with different percentage. The Divela variety was higher percentage of infestation and high population density of aphid which averaged 1.47 insect/ leaf while in Alazata was the lower population density which averaged 1.02 in
... Show MoreBackground: The timing of eruption of permanent teeth is of considerable importance to the dental health planning for diagnostic, preventive and therapeutic measures for children and teenagers. The purposes of this study were to determine timing of maxillary and mandibular permanent teeth emergence (except third molars) and to evaluate the effect nutritional status by anthropometric measures on the eruption time of permanent teeth, investigations had been done according to jaw and gender variations. Materials and Methods: This study was conducted among four to fifteen years old children and teenagers from kindergarten and schools in Basrah city in the south region of Iraq. The total sample composed of 1807 children and teenagers that were
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