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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 Dec 30 2012
Journal Name
Al-kindy College Medical Journal
Comparison Between Different DNA and Conventional
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Background: The discriminative power of the classical WHO parameters in relation to male fertility is quite low, because they only address few aspects of sperm quality and function. This has led investigators to focus their attention on the male gamete and in particular its genome.Objective: To explore which of the sperm DNA damage parameters measured by comet assay are more reliable, and their relations with the standard semen parameters.Methods: Study was done on 40 infertile men selected from couples attending the Institute of Embryo Reasearch and Infertility Treatment at Al-Kadhimiya City/ Baghdad in the period between February 2009 and May 2009, with a history of infertility of ≥1 years; and 15 healthy volunteers of proven fertili

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Publication Date
Sun Jul 01 2012
Journal Name
Journal Of Techniques مجلة التقني
A STUDY OF SOME TECHNICAL AND ECONOMICAL PARAMETERS FOR MACHINERY UNIT (NEW HOLLAND &DISC PLOW) BY USING THREE DIFFERENT TILT ANGLES دراسة بعض المؤشرات الفنية والأقتصادية للوحدة الميكنية (الجرار نيوهولاند مع المحراث القرصي الثلاثي القلاب) بأستخدام زوايا ميل مختلفة للأقراص
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Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
North and north-eastern wind and its impact on the racial temperature and humidity in Iraq
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The study area is witnessing divergence where I am North wind North East wind as we find that the north wind is getting replicated as we move from the south, The reason can be attributed to the nature of the surface of the region, with at least repeat this wind the northern region to the presence of mountain ranges, while we find that energizes the surface in the center and south helped to increase repeat this wind gusts, It also finds that the North wind East prevail in the northern region and least replicated as we move from the north to the south and to the fact that North stations are within blowing this wind sites for the circles near the display of high pressure located centers to the north-east, north and distancing itself from pa

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Publication Date
Wed Apr 20 2022
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Optical Properties of Organic Beetroot Dye and its Different Applications
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    Extraction and preparation of red organic dye from beetroot plant in different concentrations by using the solvent extraction process. Ethanol was the solvent used to prepare five different concentrations at the ratio of (Dye: Ethanol) abbreviated (D: E) 5:0,4:1, 3:2, 2:3,1:4. The optical, structural, and morphological properties are studied for the samples. The results appeared using the UV-Vis spectroscope the maximum peak of absorption (A) spectrum at wavelength Aλmax=480 nm when the transmittance (T) at the same wavelength 25% and the reflectivity 0.8%. Florescent (F) spectrum of beetroot dye is measured at wavelength Fλmax=535nm achieved to redshift about Δλ=55 nm. Also, measured the energy band gap

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Publication Date
Sun Jul 01 2001
Journal Name
Bulletin Of The Iraq Natural History Museum (p-issn: 1017-8678 , E-issn: 2311-9799)
A COMPARATIVE STUDY OF ECOLOGICAL AND GENETICAL ADAPTATION OF THREE IRAQI FRESH WATER SNAILS IN RESPECT TO HEAVY METAL POLLUTION
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A comparative study was carried out on ecological and genetical adaptation of three Iraqi
freshwater snails, Physa acuta, Melanopsis buccinoidea and Melanoides tuberculata, in
respect to acute toxicity of heavy metals (Zn, Cd and Hg). Longevity are used as poisoning
tolerance criterion. LT 50 and LT 100 were determined for the studied snails at (0.5, 1, 5, and
10 ppm), for the three metals. Results indicated that Physa acuta had a higher tolerance than
Melanopsis buccinoidea and Melanoides tuberculata, which was the lower one. Previous
exposure to heavy metals in the original habitat was affecting on experimental tolerance and
no relationships of physical and chemical factors (total hardness, temperature, D. O. and

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Publication Date
Fri Jan 31 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Comparison of regional bond strength among different types of posts luted with different types of cement
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Background: This in vitro study was carried out to investigate the effect of post space regions (coronal, middle and apical), the effect of post types ( Manually Milled Zirconia post, Prefabricated Fiber post, prefabricated Zirconia post) and the type of cement used (GIC, self-adhesive resin cement) on the bond strength between the posts and root dentin by using push-out test. Material and methods: Forty eight mandibular premolars extracted for orthodontic reasons (single rooted) were instrumented with ProTaper system (hand use) and obturated with gutta percha for ProTaper using AH26® root canal sealer following the manufacturer instructions. After 24 hours, post space was prepared using Zirix and Glassix drills no.3 creating 8 mm dept

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Publication Date
Thu Apr 01 2021
Journal Name
Biochemical & Cellular Archives
Impacts of Starvation Stress on Biofilm Formation and expression of Virulence Genes in Mono-and Mixed-species cultures of Pseudomonas Aeruginosa and Staphylococcus aureus
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Staphylococcus aureus and Pseudomonas aeruginosa are the major globally distributed pathogens, which causes chronic and recalcitrant infections due to their capacity to produce biofilms in large part. Biofilm production represents a survival strategy in these species, allowing them to endure environmental stress by altering their gene expression to match their own survival needs. In this study, we co-cultured different clinical isolates of S. aureus and P. aeruginosa as mono- and mixed-species biofilms in a full-strength Brain Heart Infusion Broth (BHI) and in a 1000-fold diluted Brain Heart Infusion Broth (BHI/1000) using Microtiter plate assay and determination of colony-forming units. Furthermore, the effect of starvation stress on the e

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Publication Date
Fri Dec 29 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Temperature Effects on Intensity Distribution at Emage Plane
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To evaluate the effects of the thermal analysis and temperature of the atmospheric heat on the optical system. it varying the thermal expansion  (positive  or  Negative  Values)  of  the  material  and  then changes the characteri of the optical system properties such as radius of curvetur of the surfaces, size of the aperture stop     ect.

This paper  had calculated the accepted ratio of the temperature variable   on the optical system during analyzing the effect of thermal analysis on the Radial Energy Distribution for +20C0 and +50C0  â€¢

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Publication Date
Sat Aug 10 2019
Journal Name
Engineering, Technology & Applied Science Research
Performance of Segmental Post-Τensioned Concrete Beams Exposed to High Fire Temperature
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The present study illustrates observations, record accurate description and discussion about the behavior of twelve tested, simply supported, precast, prestressed, segmental, concrete beams with different segment numbers exposed to high fire temperatures of 300°C, 500°C, and 700°C. The test program included thermal tests by using a furnace manufactured for this purpose to expose to high burning temperature (fire flame) nine beams which were loaded with sustaining dead load throughout the burning process. The beams were divided into three groups depending on the precast segments number. All had an identical total length of 3150mm but each had different segment number (9, 7, and 5 segments), in other words, different segment length

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Publication Date
Wed May 15 2024
Journal Name
Chalcogenide Letters
Influence of annealing temperature on nano crystalline description for CuZnS thin films
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Copper Zinc Sulphide (Cu0.5Zn0.5S) alloy and thin films were fabricated in a vacuum. Nano crystallized (CZS) film with thick 450±20 nm was deposit at substrates glasses using thermal evaporation technique below ~ 2 × 10− 5 mbar vacuum to investigated the films structural, morphological and optical properties depended on annealing temperatures ( as-deposited, 423, 523 and 623) K for one hour. The influences annealed temperature on structurally besides morphologically characteristics on these films were investigated using XRD and AFM respectively. XRD confirms the formation a mixed hexagonal phase of CuS-ZnS in (102) direction with polycrystalline in nature having very fine crystallites size varying from (5.5-13.09) nm. AFM analys

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