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alkej-307
Study the Effect of Different Reinforcements on the Damping Properties of the Polymer Matrix Composite
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In this research, damping properties for composite materials were evaluated using logarithmic decrement method to study the effect of reinforcements on the damping ratio of the epoxy matrix. Three stages of composites were prepared in this research. The first stage included preparing binary blends of epoxy (EP) and different weight percentages of polysulfide rubber (PSR) (0%, 2.5%, 5%, 7.5% and 10%). It was found that the weight percentage 5% of polysulfide was the best percentage, which gives the best mechanical properties for the blend matrix. The advantage of this blend matrix is that; it mediates between the brittle properties of epoxy and the flexible properties of a blend matrix with the highest percentage of PSR. The second stage included reinforcing the best blend matrix of epoxy-polysulfide (the blend matrix with the best percentage of polysulfide resulted from the previous stage), by different volume percentages of short fibers (Carbon& Glass) separately and randomly. The volume percentages of fibers were (2.5%, 5%, 7.5%, and 10%). The third stage included reinforcing the blend composites with highest percentages of carbon and glass fiber, by different weight percentages of nano-particles (Red mud& Fly ash) separately. The weight percentages of particles were (0.5%, 1%, 1.5%, and 2%). The experimental results showed that blending polysulfide rubber with epoxy increased the damping ratio. As for reinforcement materials, they decreased the damping ratio, where glass fiber composites have significantly higher damping ratio than other composites.

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Publication Date
Mon Jun 05 2023
Journal Name
Journal Of Economics And Administrative Sciences
The Effect of Knowledge Upgrading on Business Continuity:A Field Research in Private Colleges and Universities in Baghdad
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The research aims to study the effect of knowledge upgrade on business continuity in private colleges and universities in Baghdad. The research problem is summarized in the main question (were the academic leaders able to employ knowledge upgrading to enhance business continuity). The most important of this sector were the universities and the private college in the city of Baghdad as a field for this research, the researchers conducted a field visit to (10) universities or private colleges, the research sample consisted of (177) individuals from the deans of colleges and their assistants, as well as heads of scientific and administrative departments. The data was analyzed and the hypotheses were tested using the appropriate statistical

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Publication Date
Sat Feb 01 2020
Journal Name
Journal Of Economics And Administrative Sciences
Effect of Job Burnout on Employee Performance: Field Research in the General Company for Vegetable Oil Industry
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Abstract

      This research aims to know the effect of job burnout in the worker’s performance. The researcher presented a theoretical basis for job burnout and the worker's performance. In order to achieve the objectives of the research, a hypothesis was drawn up that determines the nature of the relationship between the independent variable of job burnout and its dimensions (reduced personal accomplishment, depersonalization, Emotional Exhaustion) and variable dependent performance of workers dimensions (productivity, job satisfaction, organizational commitment, creativity), And to represent the volume of this community according to (de Morgan, D. Morgan) glo

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Publication Date
Mon Mar 01 2010
Journal Name
Al-khwarizmi Engineering Journal
Microstructure and Some Properties of Aluminum-Silicon Matrix Composites Reinforced by Alumina or Chromia
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In this work, yttrium oxide particles (powder) reinforced AL-Si matrix composites (Y2O3/Al-Si) and Chromium oxide particles reinforced AL-Si matrix composites (Cr2O3/AL-Si) were prepared by direct squeeze casting. The volume percentages of yttrium oxide used are (4, 8.1, 12.1, 16.1 vol %) and the volume percentages of the chromium oxide particles used are (3.1, 6.3, 9.4, 12.5 vol. %). The parameters affecting the preparation of Y2O3/Al-Si and Cr2O3/AL-Si composites by direct squeeze casting process were studied. The molten Al-Si alloy with yttrium oxide particles or with chromium oxide particles was stirred again using an electrical stirrer at speed 500 rpm  and the molten alloy was  poured  into the squeeze die cavity. Th

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Publication Date
Sun Dec 01 2013
Journal Name
Journal Of Accounting And Financial Studies ( Jafs )
Multi-pages structure for Six Sigma performance matrix based on the technical characteristics of balanced performance and methodology Al-Sigma for measuring corporate performance: Suggestion vision
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Accelerates operating managements in the facilities contemporary business environment toward redefining processes and strategies that you need to perform tasks of guaranteeing them continue in an environment performance dominated by economic globalization and the circumstances of uncertainty attempt the creation of a new structure through multiple pages seek to improve profitability and sustainable growth in performance in a climatefocuses on the development of institutional processes, reduce costs and achieve customer satisfaction to meet their demands and expectations are constantly changing. The research was presented structural matrix performance combines methodology Alsigma in order to improve customer satisfaction significantly bet

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Publication Date
Sun Oct 25 2020
Journal Name
International Journal Of Psychosocial Rehabilitation
EFFECT OF EXERCISES USING DIFFERENT RESISTORS IN THE DEVELOPMENT OF THE SPECIAL STRENGTH OF THE ARMS AND THE COMPLETION OF JAVELIN FOR THE ATHLETES OF THE SCHOOL SPECIALIZED ATHLETICS
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Athletics are different from other games as a competition between individuals to show their competence and physical ability to achieve new record numbers in the various activities and various between the boards, jumping and throwing and each type of these activities in particular performance so found the researcher to find the method of training resistors in the development of special power and achievement In the effectiveness of javelin, where the researchers chose the sample of the athletes from the specialized school of athletics to effectively throw the spear at the ages of 15-17 years and carried out the tests of the research, which includes the strength of the speed of the arms and explosive power and The various resistance exercise

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Publication Date
Sun May 01 2016
Journal Name
Journal Of Engineering
Temperature Effect on Power Drop of Different Photovoltaic Modules
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Solar module operating temperature is the second major factor affects the performance of solar photovoltaic panels after the amount of solar radiation. This paper presents a performance comparison of mono-crystalline Silicon (mc-Si), poly-crystalline Silicon (pc-Si), amorphous Silicon (a-Si) and Cupper Indium Gallium di-selenide (CIGS) photovoltaic technologies under Climate Conditions of Baghdad city. Temperature influence on the solar modules electric output parameters was investigated experimentally and their temperature coefficients was calculated. These temperature coefficients are important for all systems design and sizing. The experimental results revealed that the pc-Si module showed a decrease in open circuit v

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Publication Date
Tue Jan 06 2026
Journal Name
Frontiers In Mechanical Engineering
Effect of different wing geometries on their vibration characteristics
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Understanding how wing geometry and internal structural configuration influence vibration behavior is essential for ensuring the aeroelastic stability and structural integrity of modern aircraft. This study presents a comprehensive numerical investigation of the modal and deflection characteristics of aircraft wings with different geometries (symmetric tapered planform and swept-back) and spar configurations (box and I-section) using the finite element method (FEM) in ANSYS Mechanical APDL R.15. Six NACA airfoil profiles (0024, 2411, 2416, 2424, 4412, and 4421) with angle of attack 9° under 50 m/s speed and 1,100 kg pay load were analyzed under identical aerodynamic and material conditions using linear elasti

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Publication Date
Thu Jun 30 2022
Journal Name
Journal Of Economics And Administrative Sciences
The Impact of Governance Mechanisms on the Accounting Disclosure of the Sustainable Development of Iraqi Economic Units
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The research aims to demonstrate the impact of governance mechanisms on the quality of financial reports in the light of the accounting disclosure for sustainable development represented in (accounting disclosure for economic development, accounting disclosure for environmental development, and accounting disclosure for social development) in a sample of banks listed in the Iraq Stock Exchange.

Governance mechanisms were measured by evaluating and analyzing the mechanisms in banks for the research sample consisting of (15) banks, based on the governance guide issued by the Central Bank, as well as the banks’ financial reports for the years 2016 -2018, and the dimensions of accounting disclosure for sust

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Publication Date
Wed Feb 01 2017
Journal Name
Journal Of Economics And Administrative Sciences
The development of ethics management system to enhance the social responsibility of government institutions in Iraqi society An analytical study on a sample of top leadership and the presidency of
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Abstract

The objective of this research is to identify the analysis of the ethics of the administration in the development of the social responsibility of one government organizations, and to achieve the objectives of the research was the use of a questionnaire developed for the purpose of data collection and distribution to the research sample, was chosen as a total sample population (50) individuals were relying on statistical package to do a statistical analysis for this research, user, ANSI (SPSS) simple regression analysis, standard deviation, Pearson correlation coefficient.

Research findings show the role of social responsibility in achieving the university's strategy,

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Publication Date
Wed Mar 18 2020
Journal Name
Baghdad Science Journal
The A Comparative Study of the Adsorption of Crystal Violet Dye from Aqueous Solution on Rice Husk and Charcoal
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            In this work, the adsorption of crystal violet dye from aqueous solution on charcoal and rice husk has been investigated, where the impact of variable factors (contact time; the dosage of adsorbent, pH, temperature, and ionic strength) have been studied. It has been found that charcoal and rice husk have an appropriate adsorption limit with regards to the expulsion of crystal violet dye from fluid arrangements. The harmony adsorption is for all intents and purposes accomplished in 45 min for charcoal and 60 min for rice husk. The amount of crystal violet dye adsorbed (0.4 g of charcoal and 0.5 g of rice husk) increased with an increasing pH and the value of 11 is the best

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