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Studying the Effect of Addition Particles of Alumina (Al2O3) and Zirconia (ZrO2), on Some Mechanical Properties for Matrix Composites (Al-Si-Mg) Alloy
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This study is concerned with the effect of adding two kinds of ceramic materials on the mechanical properties of (Al-7%Si- 0.3%Mg) alloy, which are zirconia with particle size (20μm > P.S ≥ 0.1μm) and alumina with particle size (20μm > P.S ≥ 0.1μm) and adding them to the alloy with weight ratios (0.2, 0.4, 0.6, 0.8 and 1%). Stirring casting method has been used to make composite material by using vortex technique which is used to pull the particles to inside the melted metals and distributed them homogenously.

After that solution treatment was done to the samples at (520ºC) and artificial ageing at (170ºC) in different times, it has been noticed that the values of hardness is increased with the aging time of the original alloy and reached its highest value after (8hr).

Mechanical tests were done to the original alloy and the composite material at the maximum hardness value and represented by tensile, hardness, and wear tests. It was found that the hardness value is increased with increment of the amount of added particles; also the increment in the hardness of the alloy which is reinforced with alumina is more than that reinforced with zirconia.

Regarding the tensile test, results show that the strength and yield resistance of the composite material are more than that in the original alloy and these values are increased with increasing the amount of the added particles and they reached maximum values at (0.6%). Then they are decreased but these values remain at higher values than those in the original alloy. However, the ductility is decreased as compared with the original alloy and this decrement was more obvious with the increasing amount of the added particles. The increment of strength and yield resistance of the alloy reinforced by alumina was higher than that reinforced with zirconia, while the ductility of the alloy reinforced by zirconia was higher than that happened by the addition of alumina. Also zirconia and alumina addition to the original alloy decreased the wear rate, and the decrement would be more with the increased amount of adding particles. In addition the wear resistance of the alloy reinforced with alumina was larger than that reinforced with zirconia. X-rays testing proved that secondary phase (AlFeSi) appeared in both original alloy and the composite material. While heat treatment led to the appearance of phases (Mg2Al) and (Mg2Si) in original alloy. This was led to obvious improvement in the mechanical properties in addition to appearance ceramic particles in the microstructure of the composite material.

This structure somewhat homogenous has fine grains as compared with large grains in the microstructure of the original alloy. .        

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Publication Date
Sun Jul 09 2023
Journal Name
Journal Of Engineering
A study of the Effect of Air Inlet and Exit on Indoor Air Movement
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This work consists of a numerical simulation to predict the velocity and temperature distributions, and an experimental work to visualize the air flow in a room model. The numerical work is based on non-isothermal, incompressible, three dimensional, k turbulence model, and solved using a computational fluid dynamic (CFD) approach, involving finite volume technique to solve continuity, momentum and energy equations, that governs the room’s turbulent flow domain. The experimental study was performed using (1/5) scaled room model of the actual dimensions of the room to simulate room air flow and visualize the flow pattern using smoke generated  from burnt herbs and collected in a smoke generator to delivered through

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Publication Date
Sat Feb 14 2026
Journal Name
Journal Of Baghdad College Of Dentistry
Effect of canal dryness and flaring on the accuracy of two electronic apex locators
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Background: This in vitro study evaluated the effect of canal dryness and flaring on the accuracy of two electronic apex locators for working length (WL) determination. Materials and methods: Sixty extracted teeth were used, after access opening was done, the occlusal surface was flattened to create stable reference point. The teeth were randomly divided into two equal main groups of flared and unflared group each one of 30 teeth. The flaring was done with Gates Glidden drills. The two main groups were further subdivided into two subgroups: dry canal and wet canal using 5.25% sodium hypochlorite groups, Electronic WL of each sample was determined using both Root ZX and i-Root apex locator. Consequently, histologic WL was determined by shav

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Publication Date
Thu Apr 21 2016
Journal Name
Iraqi Journal Of Agricultural Sciences
EFFECT OF SHEEP MANURE EXTRACT ON THE GROWTH AND NUTRIENTS CONTENT OF TOMATO SEEDLINGS
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The experiment was conducted under shading (with the aid of Saran) condition on a nursery managed by the Baghdad Mayoralty during the season of 2014-2015 to study the effect of composed sheep manure extract on the growth and leaf nutrients content of tomato seedlings var. Wijdan. The experiment was composed of 6 treatments included the extract of sheep manure by hot (425C)and lmbient(205C) temperature water .The extract was diluted to the half by water and foliar applied to seedlings (multible application) or to the soil . Treatments also included the application of NPK chemical fertilizers as recommended and a control treatment through applying distilled water as foliar .The experiment was designed according to the randomized compl

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Publication Date
Tue Jan 08 2019
Journal Name
Iraqi Journal Of Physics
Effect of thickness on the structure, morphology and A.C conductivity of Bi2S3 thin films
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Thin films samples of Bismuth sulfide Bi2S3 had deposited on
glass substrate using thermal evaporation method by chemical
method under vacuum of 10-5 Toor. XRD and AFM were used to
check the structure and morphology of the Bi2S3 thin films. The
results showed that the films with law thickness <700 nm were free
from any diffraction peaks refer to amorphous structure while films
with thickness≥700 nm was polycrystalline. The roughness decreases
while average grain size increases with the increase of thickness. The
A.C conductivity as function of frequency had studied in the
frequency range (50 to 5x106 Hz). The dielectric constant,
polarizability showed significant dependence upon the variation of
thic

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Publication Date
Fri Sep 01 2017
Journal Name
International Journal Of Science And Research (ijsr)
Effect of Lepidium sativum Aqueous Crude Extract in Some Fertility Parameters in Mice, IJSR, Call for Papers, Online Journal
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The uses of traditional plant extract in the treatment of various diseases have been flourished. The present study, IJSR, Call for Papers, Online Journal

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Publication Date
Mon Apr 01 2019
Journal Name
Journal Of Educational And Psychological Researches
Teachers and Headmasters’ Perspectives toward the Application of the Organizational Culture in the Intermediate and Secondary Schools in Arar city
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The aim of the current research is to identify the level of organizational culture among the headmasters and teachers of intermediate and secondary schools in Arar city. It also aims to identify the effect of job variables, qualifications, educational stage, and years of experience on the level of organizational culture and its domains. The research sample consisted of 62 participants divided into 7 headmasters and 55 teachers. The researcher used the questionnaire of the organizational culture. The researcher used also statistical methods such as mean, standard deviation, t-test, and One way ANOVA. The results revealed that the level of organizational culture and its four domains were high, and there was no effect of the variables (teac

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Publication Date
Sun Aug 30 2020
Journal Name
Journal Of Economics And Administrative Sciences
Comparison of the performance of some r- (k,d) class estimators with the (PCTP) estimator that used in estimating the general linear regression model in the presence of autocorrelation and multicollinearity problems at the same time "
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In the analysis of multiple linear regression, the problem of multicollinearity and auto-correlation drew the attention of many researchers, and given the appearance of these two problems together and their bad effect on the estimation, some of the researchers found new methods to address these two problems together at the same time. In this research a comparison for the performance of the Principal Components Two Parameter estimator (PCTP) and The (r-k) class estimator and the r-(k,d) class estimator by conducting a simulation study and through the results and under the mean square error (MSE) criterion to find the best way to address the two problems together. The results showed that the r-(k,d) class estimator is the best esti

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Publication Date
Thu Apr 01 2021
Journal Name
Biochem. Cell. Arch
Biological Therapy for Patients With Rheumatoid Arthritis and Its Effect on Periodontal and Immunological Parameters
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Rheumatoid arthritis and periodontitis use analogous effector destructive procedures, in that the inflammatory cells and pro-inflammatory cytokines that drive chronic bone erosion in RA and chronic periodontal destruction in Periodontitis are alike. Periodontitis (PD) has appeared as a hazard factor in a number of health situations as rheumatoid arthritis (RA). To determine the effect of anti-tumor necrosis factor alpha biological treatment (methotrexate and Enbrel or infliximab) on periodontal status of patients having rheumatoid arthritis with periodontitis in comparison to those having periodontitis without rheumatoid arthritis and control healthy subjects and to determine the serum levels of anti-cyclic citrullinated peptide (ACCP) in t

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Publication Date
Sat Dec 01 2012
Journal Name
Journal Of Economics And Administrative Sciences
The Concept of Fairness Accounting and its Role in Reducing Earnings Management Practices
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The aims of research is diagnose and indicate the role of fairness in the work of accounting, which is important in reducing the unacceptable practices to manage earnings by economic units, As well as the interpretation and indicate Ethical inside in the accounting and accountants in particular practices in the area of ​​earnings management to reduce the negative effects of the practice and display the results mentioned acts according to what is supposed to be for the purposes of service users, Researchers have identified that one hypothesis, that "Fairness of accountants in of their work accounting lead to a reduction of earnings management practices". The results suggest that the accounting practices that lead to the manipu

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Publication Date
Mon Mar 01 2021
Journal Name
مجلة العلوم القانونية
أساس انتقال المخاطر في عقود التجارة الدولية
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أساس انتقال المخاطر في عقود التجارة الدولية