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alkej-449
Effect of Laser Shock Peening on the Fatigue Behavior and Mechanical Properties of Composite Materials
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In this study, Laser Shock Peening (LSP) effect on the polymeric composite materials has been investigated experimentally. Polymeric composite materials are widely used because they are easy to fabricate and have many attractive features. Unsaturated polyester resin as a matrix was selected and Aluminum powder with micro particles as a reinforcement material was used with different volume fraction (2.5%, 5% and 7.5%). Hand lay-up process was used for preparation the composites. Fatigue test with constant amplitude with stress ratio (R =-1) was carried out before and after LSP process with two levels of energy (1Joule and 2Joule). The result showed an increase in the endurance strength of 25.448% at 7.5% volume fraction when peened is 1J laser energy. Also, the ultimate strength and Young’s modulus were increased by 6.474% and 10.588% respectively after LSP with the same laser energy.  On the other hand, composites with (2.5% and 5%) volume fraction manifested a reduction in the mechanical and fatigue strength especially when treated by 2J laser energy.

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Publication Date
Wed Jan 01 2020
Journal Name
Biochemical And Cellular Archives
EVALUATION OF WATER STRESS EFFECT ON SOME CHEMICAL PROPERTIES OF SEVERAL SUNFLOWER VARIETIES CALLUS TREATED WITH ULTRAVIOLET
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The study was carried out in plant tissue culture laboratory, University of Baghdad during the period 2017-2019, as factorial experiment in complete randomized design, to study the effect of PEG at (0, 2, 4, 6 and 8%) on physiological and chemical changes in callus of three sunflower (Ishaqi 1, Aqmar and Al-haga) induced by the cultivation of the young stem in vitro under water stress. The content of callus cells of SOD, POD, CAT and APX enzymes as well as content of hydrogen peroxide were determined as indicators to determine the effect of PEG in callus tissue cells cultivated on medium equipped with the PEG concentrations. The results showed that cultivars were differs significantly and Al-hajavariety was superior in increasing SOD to 24.

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Publication Date
Fri Jan 01 2021
Journal Name
E3s Web Of Conferences 318, 03002 (2021)
A Comparative Study on Behavior of RC Columns Strengthened by CFRP and Steel Jacket
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This paper studies the behavior of axially loaded RC columns which are confined with carbon fiber reinforced polymers’ sheet (CFRP) and steel jackets (SJ). The study is based on twelve axially loaded RC columns tested up to failure. It is divided into three schemes based on its strengthening type; each scheme has four columns. The main parameters in this study were the compressive strength of the concrete and steel reinforcement ratio. Furthermore, the results of the experimental test showed a substantial enhancement in the column's load-carrying capacity. When compared to the original columns, the CFRP sheet had a significant effect on improving the ductility of the column by increasing the axial deformation by about 59.2 to 95.7

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Publication Date
Thu Aug 01 2024
Journal Name
Iop Conference Series: Earth And Environmental Science
Study on Strength Behavior of Expansive Soil Stabilized with Dune Sand and Sodium Silicate
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Abstract<p>When designing structures constructed on soil that undergoes volumetric changes due to variations in its moisture content, the upward pressure exerted by the soil poses a risk to the safety of the facilities. A significant number of researchers are looking into solutions to either treat these soils or lessen the detrimental consequences they have. One treatment option involves stabilizing these soils by adding low-expansion soil or materials, which can impact their swell characteristics. This study aimed to investigate the effect that the addition of dune sand and sodium silicate material would have on the swellability and strength behaviour of swellable bentonite soil. Soil samples w</p> ... Show More
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Publication Date
Sun Aug 01 2021
Journal Name
International Journal Of Mechanical Engineering And Robotics Research
International Journal of Mechanical Engineering and Robotics Research
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This paper proposes feedback linearization control (FBLC) based on function approximation technique (FAT) to regulate the vibrational motion of a smart thin plate considering the effect of axial stretching. The FBLC includes designing a nonlinear control law for the stabilization of the target dynamic system while the closed-loop dynamics are linear with ensured stability. The objective of the FAT is to estimate the cubic nonlinear restoring force vector using the linear parameterization of weighting and orthogonal basis function matrices. Orthogonal Chebyshev polynomials are used as strong approximators for adaptive schemes. The proposed control architecture is applied to a thin plate with a large deflection that stimulates the axial loadi

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Publication Date
Sun Sep 06 2009
Journal Name
Baghdad Science Journal
Influence of Immersion Period on the Corrosion Behavior of Heat Treated Biomedical Alloy Ti -5Al - 2.5Fe
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Heat treatment by solid solution method in the ?+? phase region was used at 970°C for Ti-5Al-2.5Fe alloy. The specimens cooled under different cooling media [water quenched (WQ), air cooled (AC) and furnace cooled (FC)], and subsequently aged at 550°C for 4 hours. Five specimens from each treatment were immersed in simulated body fluid SBF for a period of time (3 months). The dependence of corrosion rate on compositional variation in the phases resulted from various type of cooling rates are discussed based on immersion tests. The EDXA results show the precipitation of phosphate and calcium compounds on the alloy after 3 months of immersion in blood plasma solution forming a bone-like apatite, which enhanced the alloy biocompatibility ma

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Publication Date
Tue Aug 01 2023
Journal Name
International Journal Of Intelligent Systems And Applications In Engineering
Impact of Zinc Oxide on the Structural and Dielectric Properties of NiO/ZnO Composites
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The a.c conductivity and dielectric properties of the prepared composites NiO:ZnO composites samples with various mixing ratios (100:0,80:20,60:40,40:60,20:80 and 0:100) wt. % were carried out . The structure phase, the crystallite size and purity of the fabricated NiO:ZnO composites were confirmed using x-ray diffraction pattern. The results declared that the diffraction spectrum of composites samples were compatible with cubic and hexagonal structures phases for 100%NiOand ZnO respectively while the spectrum were compatible with both phases for the residual composites samples. The crystallite size of the most pronounced plane (101) for crystal growth was changed from 23 nm to 49 .4 nm by

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Scopus
Publication Date
Thu Dec 01 2011
Journal Name
Journal Of Engineering
THE STATIC ANALYSIS OF COMPOSITE AIRCRAFT WINGBOX STRUCTURE
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In this paper, the static analysis for finding the best location of boxes inside the composite wing-box structure has been performed. A software ANSYS (ver.11) was used to analyses the Aluminum wing to find the maximum stresses reached in. These results are used as a base for the composite wingbox to find the numbers of layers and location of the box beam and its dimensions so that the composite wingbox may carry the same loading conditions in the Aluminum wing. Analysis showed that a composite wingbox having two boxes is better than the single or triple boxes wing based on stress to weight ratio. Mass saving of (40%) had been achieved when composite wing-box is used instead of Aluminum wing.

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Publication Date
Sat Sep 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
Studying and analysis effect level of the Government expenditure and Gross Domestic product in size of the expenditure on the higher education in Iraq (1995 – 2009)
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The education, especially higher education, is an essentially factor in the progress of any society, if we consider the higher education, represents the top  of  the education`s  pyramid which take part in developing the human  resources and provide the human staff to raise the productive efficiency, and improve the social , economic level                                  

In order to face the increasing importance of higher education, great capabilities and expenditures must be available in a continous way, such expe

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Publication Date
Fri Oct 09 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Aging effect of different types of composite resin restoration on shear bond strength to different orthodontic adhesives with sapphire bracket (In vitro comparative study)
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Background: This study was performed to determine the effect of aging of different types of composite material restorations on: Shear bond strength (SBS) to light cure and no mix chemical cure orthodontic adhesives with sapphire bracket and the debonding failure sites. Materials and methods: One hundred forty four composite disks were made from three different composite resin materials which are: 3M Filtek Z250, 3M filtek Z350 and 3M Valux plus, each group with (48) disks each, then according to the duration of storage each group was subdivided into two equal groups one of them stored for one day and the other was stored for one month, then each group was further subdivided into two equal subgroups with (12) disks each one bonded with ligh

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Publication Date
Mon Jun 19 2023
Journal Name
Journal Of Engineering
Some Properties of Superplasticized and Retarding Concrete Under Effect of Accelerated Curing Methods
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In recent decades, tremendous success has been achieved in the advancement of chemical admixtures for Portland cement concrete. Most efforts have concentrated on improving the properties of concrete and studying the factors that influence on these properties. Since the compressive strength is considered a valuable property and is invariably a vital element of the structural design, especially high early strength development which can be provide more benefits in concrete production, such as reducing construction time and labor and saving the formwork and energy. As a matter of fact, it is influenced as a most properties of concrete by several factors including water-cement ratio, cement type and curing methods employed.
Because of acce

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