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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
Wed Sep 30 2020
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
The effect of Auditing Quality on the Earnings Quality: (An applied research in a sample of private joint stock companies listed on the Iraq Stock Exchange)
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The research aims to measure the impact of the quality of the audit on the Earnings Quality, for a sample of private joint stock companies listed on the Iraq Stock Exchange, as the research sample included (14) private and listed joint stock companies in issuing their financial statements for the period from (2010-2018), as well as companies The audit offices in charge of auditing these companies, which number (18) companies or an audit office, and the research relied on two main models for measurement, as the first model reflects the assumed relationship between independent variables represented in the characteristics of external audit quality and measuring the extent of its impact on the dependent variable represented in the Ea

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Publication Date
Mon Feb 04 2019
Journal Name
Journal Of The College Of Education For Women
THE EFFECT OF AGE ON DEVEOPMENT OF CONCEPT OF MIND
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Educational of the mind is a weapon to a different knowledges which
benefit in ife and developed the mind in many field and practice him in a
regular form in a right thinking and practice sense on exactly recognizing and
conception things which is senses and regulating the memory and providing
with benefit information which fit to minded of person,the present research
aimed at answering the following two questions:
1-Does the concept of mind differ with age?
2-Does the recognition on function of mind developed with development of
age?
The research population consisted of the children in the primary schools
of Baghdad/center,and the students of the Education for woman
college/Baghdad university for the age

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Publication Date
Thu May 31 2012
Journal Name
Al-khwarizmi Engineering Journal
An Experimental Study on the Effect of Shape and Location of Vortex Generators Ahead of a Heat Exchanger
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An experimental study is carried out on the effect of vortex generators (Circular and square) on the flow and heat transfer at variable locations at (X = 0.5, 1.5, 2.5 cm) ahead of a heat exchanger with Reynolds number ranging from 62000< Re < 125000 and heat flux from 3000 ≤ q ≤ 8000 W/m2 .

In the experimental investigation, an apparatus is set up to measure the velocity and temperatures around the heat exchanger.                     

The results show that there is an effect for using vortex generators on heat transfer. Also, heat transfer depends on the shape and location. The circular is found t

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Publication Date
Thu Sep 08 2022
Journal Name
Al-khwarizmi Engineering Journal
Performance Prediction in EDM Process for Al 6061 Alloy Using Response Surface Methodology and Genetic Algorithm
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The Electric Discharge (EDM) method is a novel thermoelectric manufacturing technique in which materials are removed by a controlled spark erosion process between two electrodes immersed in a dielectric medium. Because of the difficulties of EDM, determining the optimum cutting parameters to improve cutting performance is extremely tough. As a result, optimizing operating parameters is a critical processing step, particularly for non-traditional machining process like EDM. Adequate selection of processing parameters for the EDM process does not provide ideal conditions, due to the unpredictable processing time required for a given function. Models of Multiple Regression and Genetic Algorithm are considered as effective methods for determ

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Publication Date
Mon May 31 2021
Journal Name
Iraqi Geological Journal
Effect of Shatt Al-Arab Salinity on the Groundwater of Al-Fao and Al-Siba in Southern Iraq
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This study was conducted to estimate the extent of damage to the population in Basra, southern Iraq, specifically the areas adjacent to the Shatt al-Arab and the Arabian Gulf, which are the Al-Fao district and the Al-Siba region. They are affected by the progression of saline water resulting from the lack of water imports and the Karun River interruption, which led to high concentrations of salts in the Shatt Al-Arabs. Consequently, its effect on lands and all life types in these areas requires correcting a map of the study area to drop the groundwater sites as well as calculate the total dissolved salts, electrical conductivity and pH. This study concluded that the groundwater contains very high percentages of total dissolved solid

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Publication Date
Wed May 01 2019
Journal Name
Solid State Phenomena
Preparation and Study of the Mechanical Properties of Unsaturated Polyester Resin/Graphene Nanocomposite
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Nanocomposite was prepared using unsaturated polyester (UP) resin as a matrix and graphene nanoparticles as a reinforcement material in six percentage weights (0, 0.1, 0.2, 0.3, 1 and 1.5%). Mechanical, calorimetric and thermal studies were performed on the (UP) resin/graphene nanocomposite. All tests showed a clear improvement of all mechanical properties examined (hardness, flexural strength (F.S), impact strength (I.S) and tensile strength (T.S)) with increasing graphene percentage. In addition, the temperature of glass transition and thermal conductivity of this composite increased with increasing graphene content.

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Publication Date
Fri Mar 31 2017
Journal Name
Al-khwarizmi Engineering Journal
Design of Nonlinear PID Neural Controller for the Speed Control of a Permanent Magnet DC Motor Model based on Optimization Algorithm
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In this paper, the speed control of the real DC motor is experimentally investigated using nonlinear PID neural network controller. As a simple and fast tuning algorithm, two optimization techniques are used; trial and error method and particle swarm optimization PSO algorithm in order to tune the nonlinear PID neural controller's parameters and to find best speed response of the DC motor. To save time in the real system, a Matlab simulation package is used to carry out these algorithms to tune and find the best values of the nonlinear PID parameters. Then these parameters are used in the designed real time nonlinear PID controller system based on LabVIEW package. Simulation and experimental results are compared with each other and showe

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Publication Date
Fri Sep 30 2011
Journal Name
Al-khwarizmi Engineering Journal
Charge Stratification and Fuel/Air Ratio Effect on the Efficiency of (ICADE) I. C. Engine Cycle
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The Isolated Combustion and Diluted Expansion (ICADE) internal combustion engine cycle combines the advantages of constant volume combustion of the Otto cycle with the high compression ratio of the Diesel cycle.   This work studies the effect of isolated air mass (charge stratification) on the efficiency of the cycle; the analysis shows that the decrease of isolated air mass will increase the efficiency of the cycle and the large dilution air mass will quench all NOx forming reactions and reduce unburned hydrocarbons. Furthermore, the effect of Fuel / Air ratio on the efficiency shows that the increase of Fuel / Air ratio will increase efficiency of the cycle.

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Publication Date
Mon Jun 01 2015
Journal Name
Journal Of The College Of Languages (jcl)
THE PARTICLES OF GRAMATICAL IN The Semitic Languages THE FARM (WAW)
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The Semitic Languages have    her its  Articulatory   That  what  we  attend  to  discuss  In  this  Research  to  Represent the  Relation  Between  them  and  the Light  Of  Semitics   a Comparative Studies  where  ever  It's  Exists   The Semitic languages by comparing the words whish most Semitic languages share with each other. We call such Words the Semitic denominator. We have adopted a comparative framework in our Research, which is based on comparing an Arabic word with its Semitic counterpart in Order to identify the forms that control grammatical  change in both language

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Publication Date
Tue Sep 01 2009
Journal Name
Journal Of Economics And Administrative Sciences
Impact of budget on the basis of activities in the implementation of competitive strategiesApplied Study in the General Company for Electrical Industries - Tammuz Laboratory
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The Contemporary Business Environment is Surrounded by many quick and continues variable and changes which has an effect on the economic units. These variables and changes like the high competition which need many tools to help them to continue and achieve The critical success. So to achieve this they have many competitive strategies like cost leadership strategy, differentiation strategy and focus strategy.

Budget is regarded one of main tools to execute objectives polices and programs of the economic units, beside show how the economic units had execute the available economic resources.

Activity based on budgeting is regarded one of the modern technique in the m

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