Preferred Language
Articles
/
XBc2CpEBVTCNdQwCWZL7
Temperature and Stress Evaluation during Three Different Phases of Friction Stir Welding of AA 7075-T651 Alloy
...Show More Authors

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.

Scopus Clarivate Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Fri Dec 24 2021
Journal Name
Iraqi Journal Of Science
A Model of Sky Temperature Estimation at 1.42 GHz using University of Baghdad’s Radio Telescope
...Show More Authors

 The objective of this study is to select a suitable observing region at Baghdad location (44o 22' 48", 33o 16' 30") with low interference that may affect frequency of 1.42 GHz. Baghdad University Radio Telescope (BURT) is used in this study to determine a convenient region for observation in Baghdad sky. Different azimuths and elevations were chosen at different observations time. The results of this study showed that the best observations regions were located at azimuth (120o-160o) and (210o-260o). These regions included less sky temperature and estimated to be (42.8 to 163) K. The sky temperature model could be represente

... Show More
View Publication Preview PDF
Scopus (2)
Crossref (2)
Scopus Crossref
Publication Date
Mon Sep 01 2014
Journal Name
Al-khwarizmi Engineering Journal
Numerical Investigation of Transient Heat Conduction through a Thermal Insulation of Temperature Dependant Thermal Properties
...Show More Authors

The two-dimensional transient heat conduction through a thermal insulation of temperature dependent thermal properties is investigated numerically using the FVM. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner surface with a step change in temperature and subjected at its outer surface with a natural convection boundary condition associated with a periodic change in ambient temperature and heat flux of solar radiation. Two thermal insulation materials were selected. The fully implicit time scheme is selected to represent the time discretization. The arithmetic mean thermal conductivity is chosen to be the value of the approximated thermal conductivity at the i

... Show More
View Publication Preview PDF
Publication Date
Fri Mar 31 2017
Journal Name
Iraqi Journal Of Pharmaceutical Sciences ( P-issn 1683 - 3597 E-issn 2521 - 3512)
The Effects of Melatonin On The Oxidative Stress , Protein Glycation , Microalbuminuria and Lipid Profile In Type II Diabetes Mellitus
...Show More Authors

Previous studies indicated that supplementation with antioxidants has a protective effects against oxidative stress–induced damage in type 2 diabetes. In this study we evaluated the antioxidant effects of melatonin on the oxidative stress parameters and microalbuminuria in type 2 DM patients. 30 patients with type 2 DM were treated with 3mg/day melatonin for 90 days. Erythrocytes and plasma MDA and glutathione, fasting plasma glucose, %HbAIC, microalbuminuria, total plasma protein and lipid profile were measured each 30 days and compared with those obtained from 20 healthy controls.

A decrease in MDA levels associated with the elevation in GSH levels were observed, compared with the pre–treatment levels.

... Show More
View Publication Preview PDF
Crossref
Publication Date
Fri Oct 30 2020
Journal Name
International Journal Of Agronomy
Molybdenum Induces Growth, Yield, and Defence System Mechanisms of the Mung Bean (Vigna radiata L.) under Water Stress Conditions
...Show More Authors

Water stress has a negative impact on the yield and growth of crops worldwide and consequently has a global impact on food security. Many biochemical changes occur in plants as a response to water stress, such as activation of antioxidant systems. Molybdenum (Mo) plays an important part in activating the expression of many enzymes, such as CAT, POD, and SOD, as well as increasing the proline content. Mo therefore supports the defence system in plants and plays an important role in the defence system of mung bean plants growing under water stress conditions. Four concentrations of Mo (0, 15, 30, and 45 mg·L−1) were applied to plants, using two approaches: (a) seed soaking and (b) foliar application. Mung bean plants were subject

... Show More
View Publication
Scopus (12)
Crossref (9)
Scopus Clarivate Crossref
Publication Date
Tue Jan 30 2024
Journal Name
Iraqi Journal Of Science
Comparison Study Between Crude and Purified L-Asparaginase From Bacillus Spp. for Reduction of Acrylamide Level During Fries Processing
...Show More Authors

     Acrylamide is a toxic chemical that is created when foods are heated; it is also available in foods containing different additives. The purpose of the study was to determine whether Bacillus spp. isolates could reduce the concentration of acrylamide in food, as well as to compare the different treatments of crude and pure L-asparaginase produced from the same bacteria in acrylamide reduction in potato slices. Our findings reveal that this bacterium could degrade acrylamide and reduce its concentration. Furthermore, the acrylamide content of potato slices reduced dramatically with increasing enzymatic treatment time, reaching the under detection limit (UDL) after 30 minutes of treatment with 84 U/ml of crude and purified

... Show More
View Publication Preview PDF
Scopus Crossref
Publication Date
Thu Jun 30 2016
Journal Name
Al-kindy College Medical Journal
The natural courses of keratometric, pachymetric and visual acuity outcomes during 1year follow up after corneal collagen cross-linking
...Show More Authors

Background: As photochemical reaction that can stiffen the cornea, CXL is the only promising method of preventing progression of keratectasia such as KC and secondary ectasia following refractive surgery. The aim of CXL is to stabilize the underlying condition with a small chance of visual improvement. Objective: To show the sequences of changes in visual acuity and topographic outcomes during 1 year post CXL for patients with progressive Keratoconus.Type of the study: Cross sectional studyMethods: CXL procedure was done for 45 eyes with progressive KC. The following parameters had been monitored pre operatively, 1, 3, 6 and 12 months postoperatively: K apex, K2, corneal thickness at thinnest location, anterior and posterior elevation po

... Show More
View Publication Preview PDF
Publication Date
Sun Jan 01 2023
Journal Name
Aip Conference Proceedings
Examining the seasonal correlation between SSN, T-Isndex, and F10.7 parameters during solar cycles 23 and 24
...Show More Authors

View Publication
Scopus (1)
Scopus Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Journal Of Engineering
Serviceability of Post-fire RC Rafters with Openings of Different Sizes and Shapes
...Show More Authors

This study deals with the serviceability of reinforced concrete solid and perforated rafters with openings of different shapes and sizes based on an experimental study that includes 12 post-fire non-prismatic reinforced concrete beams (solid and perforated). Three groups were formed based on heating temperature (room temperature, 400 °C, and 700 °C), each group consisting of four rafters (solid, rafters with 6 and 8 trapezoidal openings, and rafter with eight circular openings) under static loading. A developed unified calculation technique for deflection and crack widths under static loading at the service stage has been provided, which comprises non-prismatic beams with or without opening exposed to flexure concentra

... Show More
View Publication Preview PDF
Crossref (7)
Crossref
Publication Date
Fri Dec 01 2023
Journal Name
Baghdad Science Journal
Simultaneous Determination of Binary Mixture of Estradiol and Progesterone Using Different Spectrophotometric Methods
...Show More Authors

Four rapid, accurate and very simple derivative spectrophotometric techniques were developed for the quantitative determination of binary mixtures of estradiol (E2) and progesterone (PRG) formulated as a capsule. Method I is the first derivative zero-crossing technique, derivative amplitudes were detected at the zero-crossing wavelength of 239.27 and 292.51 nm for the quantification of estradiol and 249.19 nm for Progesterone. Method II is ratio subtraction, progesterone was determined at λmax 240 nm after subtraction of interference exerted by estradiol. Method III is modified amplitude subtraction, which was established using derivative spectroscopy and mathematical manipulations. Method IIII is the absorbance ratio technique, absorba

... Show More
View Publication Preview PDF
Crossref
Publication Date
Thu Dec 01 2011
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
ISOLATION AND IDENTIFICATION OF INTESTINAL PARASITES FROM VEGETABLES FROM DIFFERENT MARKETS OF IRAQ.
...Show More Authors

This investigation was designed to determine the occurrence of intestinal parasites in fresh
vegetables(Apium graveolense, Lepidium aucheri and Allium porrum), from different markets
as a primary effort in Iraq. Eight genera and species of intestinal parasites appear in
vegetables, they were as follow: Echinococcus sp. 50%,Oxyuris equi 45%,Habronema sp.
45%,Parascaris equroum 31.6%,Strongyloides westrei 30%,Toxocara sp. 18.3%,Ascaris
lumbricoides 11.6% and Hymenolepis sp. 8.3% .The scarcity of fresh water has meant that
urban gardeners are increasingly irrigating their plots with wastewater. This poses a threat to
public health in addition of roaming dogs in open farms. All studied areas showed high rates
of eggs

... Show More
View Publication Preview PDF