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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
Mon Apr 24 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Synthesis Of Nanostructured TiO2 Thin Films By Pulsed Laser Deposition (PLD) And The Effect Of Annealing Temperature On Structural And Morphological Properties
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  In this work, nanostructured TiO2 thin films were grown by pulsed laser deposition (PLD) technique on glass substrates. TiO2 thin films then were annealed at 400-600 °C in air for a period of 2 hours. Effect of annealing on the structural and morphological were studied. Many growth parameters have been considered to specify the optimum conditions, namely substrate temperature (300 °C), oxygen pressure (10-2 Torr), laser fluence energy density (0.4 J/cm2), using double frequency Q-switching Nd:YAG laser beam (wavelength 532nm), repetition rate  (1-6 Hz) and the pulse duration of 10 ns. The results of the X-ray test show that all nanostructures tetragonal are polycrystalline. These results show that grain size increase fr

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Environmental and Climate Changes and Cultural Response During Mid to Late Holocene at Babylon City- Iraq
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The study deals with palaeoecology and paleoclimates of Holocene sediments of historical Babylon area on palynological evidence which located at Euphrates river, (100) Km south of Baghdad. Links between environmental and socio- cultural changes are explored in archaeological and palaeoenvironmental data. The increased social and cultural developments as a response of enhanced aridity, driven by population accumulation in environments characterized by the presence of surface water resource. Three palaeoecological zones PZ1, PZ2, and PZ3 are deduced from the pollen diagram which reflect the climatic and ecologic changes throughout parts of the Holocene (5500-7500; 5500- 4000 and 4000-Present yr BP).
Cereal grasses appear at the beginnin

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Publication Date
Fri Jan 31 2025
Journal Name
Journal Of Baghdad College Of Dentistry
The effect of curvature angle and rotational speed on the cyclic fatigue of three types of rotary instrument (In vitro): comparative study
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Background: The fracture of instruments within root canal during endodontic treatment is a common incidence, fracture because of fatigue through flexure occurs due to metal fatigue, this study aimed to assess the effect of curvature angle and rotational speed on the cyclic fatigue of different type of Endodontic NiTi Rotary Instruments and compare among them. Materials and method: Three types of rotary instruments with tip size 0.25: ProTaPer F2 (Densply, Malifier) Revo-S SU( 0.06 taper, MicroMega) and RaCe system (0.06 taper, FKG, Dentaire), Forty file of each instrument were used within two canals with angle of curvature (40 &60 )at two speed (250&400)RPM, twelve group were formed for all instruments(total number=120),ten file fo

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Publication Date
Thu May 28 2020
Journal Name
Iraqi Journal Of Science
Morphological and Molecular Identification of Three Genera of the Family Heptageniidae (Ephemeroptera) from Ava Sheen Branch/ Greater Zab Tributary, North of Iraq
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The aquatic Heptageniidae family of Ava-sheen branch (Greater Zab Tributary) in Duhok Governorate/ Iraq was studied. Samples were collected using Surber stream sampler to study their diagnostic morphological characteristics and molecular phylogenetic profile using a nuclear gene 16s ribosomal RNA. The morphological and molecular identification supported that the three species, Epeorus longimanus, Heptagenia elegantula and Ephemerella cornutus belong to Heptageniidae family, while the molecular results also confirmed the monophyletic origin of these three genera.

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Publication Date
Sun Apr 30 2023
Journal Name
Iraqi Journal Of Science
Effect of Plant Growth Regulators (IBA, BA, and CCC) on Some Vegetative Characters of Three Hybrid Lily Cultivars of (Lilium spp. L.)
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The present study was conducted in the nursery of Floriculture Unit, University of
Baghdad in Iraq during September to December of 2013. Vernalized bulbs of hybrid lily
cultivars were imported from the Netherlands. The experiments were included some
hybrid lily cultivars which represent the main groups of lily (longiflorum hybrids,
Asiatic hybrid and trumpet hybrids). The three lily cultivars named as Tiger (Oriental),
Brunello (Asiatic) and White Heaven (Longiflorum) were sprayed two times, at five
weeks after planting and at eight weeks after planting with a solution of Cycocel (100
mg /l), solution of Indole butyric acid (50 mg/l) and Benzyl adenine (50 mg /l). The
results indicated that foliar spray with IBA l

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Publication Date
Sat Dec 30 2023
Journal Name
Iraqi Journal Of Science
Effect of Electric Shock on Morphological Traits, Yield, Yield Components and Protein Content of Three Varieties of Faba Beans (Vicia faba L.)
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To investigate the effect of electric shock (ES) on morphological variations of faba bean traits, seeds of three varieties of the crop were germinated. When radical was 2-5 mm, seedling were soaked in a 1% NaCl solution for 3h, then transferred to glass container with same solution. Wire with two polar were connected to the container solution and AC current 220 V was switched on for 3,6 and 9 minutes. Seedling then washed and planted at the field in winter 2010-2011,. Factorial Experiment was arranged in randomized Complete Block Design (RCBD) with three replicates were used. Seeds were collected first season of treatments, including the treatment comparison and then planted in the winter season of 2011-2012.The results obtained in the f

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Publication Date
Wed Feb 08 2023
Journal Name
Iraqi Journal Of Science
Effect of Plant Growth Regulators (IBA, BA, and CCC) on Some Flowering Characters of Three Hybrid Lily Cultivars of (Lilium spp. L.)
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The present study was conducted in the nursery of Floriculture Unit, University of Baghdad in Iraq during September to December of 2013. Vernalized bulbs of hybrid lily cultivars were imported from the Netherlands. The experiments were included some hybrid lily cultivars which represent the main groups of lily (longiflorum hybrids, Asiatic hybrid and trumpet hybrids). The three lily cultivars named as Tiger (Oriental), Brunello (Asiatic) and White Heaven (Longiflorum) were sprayed two times, at five weeks after planting and at eight weeks after planting with a solution of Cycocel (100 mg /l), solution of Indole butyric acid (50 mg/l) and Benzyl adenine (50 mg /l). The results indicated that foliar spray with IBA lead to decrease in flowe

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Publication Date
Sat Sep 03 2022
Journal Name
International Journal Of Health Sciences
Correlation between oxidative stress and clopidogrel drug in Iraqi patients with coronary artery disease
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Background: Coronary Artery Disease (CAD) is one of the largest causes of mortality worldwide. Clopidogrel, antiplatelet drug, has been widely used for management of CAD. The current study aimed to investigate the effect of clopidogrel on the oxidative stress in CAD patients. Methods: One hundred CAD patients, who were followed-up for 5 days after receiving clopidogrel, and 50 healthy volunteers were included in this study. Parameters include catalase (CAT), total antioxidant capacity (TAC), total oxidant capacity (TOC), total protein, albumin, and globulins were determined before and after treatment with clopidogrel. Results: CAT, TAC, and Tp were significantly decreased (P<0.0001) in CAD patients compared to healthy control and

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Publication Date
Fri Jan 31 2025
Journal Name
Journal Of Baghdad College Of Dentistry
Evaluation of nano surface modification on CPTi dental implant using chemical method: mechanical and histological evaluation
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Background The application of nanotechnology to biomedical surfaces is explained by the ability of cells to interact with nanometric features. The aim of this study was to consider the role of nanoscale topographic modification of CPTi dental implant using chemical etching method for the purpose of improving osseointegration. Materials and methods: Commercial pure titanium rod was machined into 20 dental implants. Each implant was machined in diameter about 3mm, length of 8mm (5mm was threaded part and 3mm was flat part). Implants were prepared and divided into 2 groups according to the types of surface modification method used: 1st group (10 implant) remained without nano surface modification (control), 2nd group include (10 implant) etche

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Publication Date
Sat Jun 01 2019
Journal Name
Agricultural Engineering
Comparing Nozzles with Different Wear Rate and Working with the Same Application Rate of Different Plant Protection Products in Aspect of Plants Condition
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Abstract<p>Three different types of nozzles (different wear rate) were used in this study. They are classified depending on the severity of their wear to three groups: new, worn and damaged nozzles. Those nozzles were spraying with the same application rate (303 l/ha) on two-year field trials; this was achieved by changing the spraying pressure for each group of nozzles in order to get the same application rate. This practice is usually done by operators of sprayers, who calibrate the sprayers on the same application rate every year without changing the nozzles, so they tend to reduce the spraying pressure in order to compensate the flow rate increase due to the nozzles yearly wear. Two types of</p> ... Show More
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