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Temperature and Stress Evaluation during Three Different Phases of Friction Stir Welding of AA 7075-T651 Alloy
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The current study performs an explicit nonlinear finite element simulation to predict temperature distribution and consequent stresses during the friction stir welding (FSW) of AA 7075-T651 alloy. The ABAQUS® finite element software was used to model and analyze the process steps that involve plunging, dwelling, and traverse stages. Techniques such as Arbitrary Lagrangian–Eulerian (ALE) formulation, adaptive meshing, and computational feature of mass scaling were utilized to simulate sequence events during the friction stir welding process. The contact between the welding tool and workpiece was modelled through applying Coulomb’s friction model with a nonlinear friction coefficient value. Also, the model considered the effect of nonlinear material properties as well as heat transfer conditions such as heat losses due to convection and thermal contact conductance between the workpiece and the backing plate interface on the thermal history. To validate the computational model results, an experimental procedure was carried out to measure temperature history on both sides of the specimen as well as the plunging force throughout the whole process time. The results obtained showed that symmetrical temperature distribution throughout the workpiece width was distinguished, implying that the tool rotation has a minor effect on the final temperature distribution. In addition, asymptotic V shape with high gradient temperature value in the weld nugget region after the full plunging was distinguished. Mechanical stresses and related plastic deformations generated, while achieving the FSW samples were evaluated in addition to the tool reaction force and heat generated to protect against tool failure.

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Publication Date
Sun Feb 03 2019
Journal Name
Journal Of The College Of Education For Women
Reading of teacher s role and position in Ibn -Al - Kateeb s book , acquaintance
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Publication Date
Fri Dec 30 2022
Journal Name
Iraqi Journal Of Chemical And Petroleum Engineering
Comparison of Estimation Sonic Shear Wave Time Using Empirical Correlations and Artificial Neural Network
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Wellbore instability and sand production onset modeling are very affected by Sonic Shear Wave Time (SSW). In any field, SSW is not available for all wells due to the high cost of measuring. Many authors developed empirical correlations using information from selected worldwide fields for SSW prediction. Recently, researchers have used different Artificial Intelligence methods for estimating SSW. Three existing empirical correlations of Carroll, Freund, and Brocher are used to estimate SSW in this paper, while a fourth new empirical correlation is established. For comparing with the empirical correlation results, another study's Artificial Neural Network (ANN) was used. The same data t

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Publication Date
Wed Oct 01 2008
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Effect of aging on growth hormone-leptin axis in normal and obese healthy subjects
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Background: Growth hormone is a hormone responsible for the normal body growth and development by stimulation protein production in muscle cells and
energy release for breakdown of fat. On the other hand leptin is a newly discovered hormone that is mainly synthesized in adipose tissues it decreases food intake by
causing satiety and promoting energy combustion . Both aging and obesity are associated with a reduction in growth hormone secretion. In the mean time obese
humans have increased circulating leptin.
Objective: The aim of this paper is to shed light on the contribution of these two hormones in the mechanism of aging process in an attempt of improving this
process for a better life at old ages.&n

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Publication Date
Mon Mar 08 2021
Journal Name
Baghdad Science Journal
The Effect of Heat Treatment on the Magnetic and Mechanical properties offe - Ni alloys.
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The aim of this work is studying the binary system ??'??? Ni?)with two ratios (y=36,80) by using casting method for preparing the samples.Magnetic and Mechanical properties have been studidt different httrea^nttem^rature.All the alloys were found a ferromagnetic behavior and sensitive to the heat treatment. Best properties were found at the heat treatment 1100 C°.A significant different results were found above 1100C° for lower magnetic and mechanical values. This is possibly due to the change on the degree of magnetic moment orders, in which most of the moments are started to remove from coupled ferromagnetically.?

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Publication Date
Wed Jan 01 2020
Journal Name
Journal Of Clinical And Experimental Dentistry
The effect of osseodensification on implant stability and bone density: A prospective observational study
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Background: The aims of this study were to evaluate the effect of implant site preparation in low-density bone using osseodensification method in terms of implant stability changes during the osseous healing period and peri-implant bone density using CBCT. Material and methods: This prospective observational clinical study included 24 patients who received 46 dental implants that were installed in low-density bone using the osseodensification method. CBCT was used to measure the bone density pre- and postoperatively and implant stability was measured using Periotest® immediately after implant insertion and then after 6 weeks and 12 weeks postoperatively. The data were analyzed using paired t-test and the probability value <0.05 was conside

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Publication Date
Tue Apr 01 2014
Journal Name
Journal Of The Faculty Of Medicine Baghdad
Comparative Study of Allopurinol and Uralyt-4 in patients with Hyperuricemia in Diyala Governorate.
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Background: Hyperuricemia represents a major public health problem; approximately most population has hyperuricemia, serum uric acid ≥6.5 mg/dL in women and ≥7.0 mg/dL in men.
Allopurinol has been approved for the treatment of hyperuricemia patients. Epidemiological and experimental studies suggest a linkage between hyperuricemia and type of treatment.
Objective: To assess the effect of allopurinol and uralyt- 4 and mixture of two drugs (allopurinol and uralyt-4) in hyperuricemia patients
Methods: A total of 60 serum patients with history of hyperuricemia, obtained from Baladrus Hospital in Diyala governorate, were included in this study. In addition, ten normal uric acid level persons used as contro

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Publication Date
Thu Jul 01 2021
Journal Name
Iraqi Journal Of Science
Alterations of Obestatin, Cardiac Markers and Lipid Profile Levels in Type 2 Diabetes Mellitus
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The current investigation aimed to test the alterations of the levels of obestatin hormone, lipid profile and cardiac function markers in relation to hyperglycemia in patients with non-insulin diabetes mellitus. The study included 118 diabetic subjects (56 males, 62 females) and 60 healthy non-diabetic subjects (30 males, 30 females). Diabetic and healthy subjects were age-matched. Serum levels of obestatin, lipid profile markers including total cholesterol (STC), triglycerides (STG), low and high density lipoproteins (LDL-C and HDL-C), as well as cardiac function markers including, creatine kinase and lactate dehydrogenase enzymes were determined in all subjects. The findings revealed a remarkable decrease in the level of serum obestati

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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Pathogenicity of Carbapenems and Third Generation Cephalosporins Resistant K. pneumoniae in Murine Urinary System
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One hundred and nine clinical lactose fermenter isolates were collected from different samples (urine, stool, wound swab, blood, and sputum) , in a period from February 2014 till May 2014. All samples gathered from Alyarmok laboratories, Alkadimiya laboratories, and Baghdad teaching laboratories which are situated at Baghdad city. Fifty three (48,62%) isolates were identified as Klebsiella pneumoniae depending on microscopic characterization , conventional biochemical tests and then the identification confirmed with API 20E system . The rest of 56(51, 38%) isolates represented other bacteria.Susceptibility test was achieved to all fifty-three K. pneumoniae isolates using five antibiotic disks (Ceftazidime, Ceftriaxone, Cefotaxime, Imipen

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Publication Date
Tue Dec 13 2022
Journal Name
Mathematical Modelling Of Engineering Problems
Dynamic Response and Reliability Analysis of Stochastic Multi-Story Frame Structures under Random Excitation
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In earthquake engineering problems, uncertainty exists not only in the seismic excitations but also in the structure's parameters. This study investigates the influence of structural geometry, elastic modulus, mass density, and section dimension uncertainty on the stochastic earthquake response of a multi-story moment resisting frame subjected to random ground motion. The North-south component of the Ali Gharbi earthquake in 2012, Iraq, is selected as ground excitation. Using the power spectral density function (PSD), the two-dimensional finite element model of the moment resisting frame's base motion is modified to account for random ground motion. The probabilistic study of the moment resisting frame structure using stochastic fin

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Publication Date
Thu May 25 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Purification, Characterization and Antifungal Activity of Chitinase from Serratia marcescens Isolated from Fresh Vegetables
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  Seven [35%] and five [25%] Serratia marcescens  isolates were obtained out of 20 samples of lettuce and 20 samples of spinach, respectively, taken from different locations in a farm in Baghdad city. The isolate that produced chitinase in higher level was chosen to purify chitinase through several stages of purification including: ammonium sulfate precipitation, DEAE- sephadex ion exchange chromatograpgy and sephadex G-200 gel filtration with 89.5- fold purification and 30% recovery.       The purified chitinase was characterized and the molecular weight of enzyme was 59000 daltons by using gel filtration chromatography. The optimum pH and temperature of the purified chitinase were 6.0 and 50°

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