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alkej-479
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. The pouring temperature that used for all castings is (700)˚C.  The required squeeze pressure, 53 MPa, was then applied for 30 seconds at a delay time of 5. The die temp is (200˚C).  The Y2O3/Al-Si composites and Cr2O3/Al-Si composites produced by squeeze casting have more microstructure refinement, higher hardness and lower wear rate than the unreinforced alloy.

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Publication Date
Mon May 22 2017
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
Study of the Physical and Morphological Properties of Ceramic Insulator
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In this investigation insulator ceramic body was prepared by using iraqi local materials, these are kaolin, silica sand glass, feldspar with weight percentage (45%,25%, 30%)respectively.  After the end of treating drying and milling of raw material mixing with different concentrations of sodium silicate(1%,0.7%,0.5%,0.2%,0.1%) while zinc oxide was added at fixed weight percentage.  A disc samples was prepared after compaction and then fired by sintering temperatures (1250, 1350)oC respectively.A surface morphology was studied by using optical microscope and measurements of apparent density and porosity was under taken to the sintered samples by using Archimedes method.The study showed that the microscopic images for samples sur

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Publication Date
Sat Jan 01 2011
Journal Name
Advances In Condensed Matter Physics
Compositional Dependence of Structural Properties of Prepared Alloys and Films
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Results of a study of alloys and films with various Pb content have been reported and discussed. Films of of thickness 1.5 μm have been deposited on glass substrates by flash thermal evaporation method at room temperature, under vacuum at constant deposition rate. These films were annealed under vacuum around 10−6Torr at different temperatures up to 523 K. The composition of the elements in alloys was determined by standard surfaces techniques such as atomic absorption spectroscopy (AAS) and X-ray fluorescence (XRF), and the results were found of high accuracy and in very good agreement with the theoretical values. The structure for alloys and films is determined by using X-ray

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Publication Date
Tue Dec 31 2019
Journal Name
Journal Of Economics And Administrative Sciences
The Role of personality characteristics of Leader in Business organizations entrepreneurship with strategic flexibility mediated (A Field Research)
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    The personality characteristics of the Leader are considered one of the main elements to reach into business organizations entrepreneurship; and because of the development of the organizations of the continuous transformations as result of huge Competition in private High Education sector, there is a great need for Leaders characterized of certain personality capable of managing their organizations and can positively effect on them. Also these organizations' success to reach into entrepreneurship requires a main significant element that is (strategic flexibility) which is considered one of the important elements for success.

    Accordingly, this research is trying to fin

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Publication Date
Wed Sep 12 2018
Journal Name
Ibn Al-haitham Journal For Pure And Applied Sciences
New Transform Fundamental Properties and Its Applications
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        In this paper, new transform with fundamental properties are presented. The new transform has many interesting properties and applications which make it rival to other transforms.

Furthermore, we generalize all existing differentiation, integration, and convolution theorems in the existing literature. New results and new shifting theorems are introduced. Finally, comprehensive list of this transforms of functions will be providing.

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Publication Date
Tue Jan 01 2013
Journal Name
Al- Mustansiriyah J. Sci.
Synthesis and Characterization of Some Mixed Ligand Complexes of Quinaldic Acid and α-Picoline with Some Metal Salts
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Some metal ions (Mn+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2 and Hg+2) complexes of quinaldic acid (QuinH) and α-picoline (α-Pic) have been synthesized and characterized on the basis of their , FTIR, (U.V-Vis) spectroscopy, conductivity measurements, magnetic susceptibility and atomic absorption. From the results obtained the following general formula has suggested for the prepared complexes [M(Quin)2( α-Pic)2].XH2O where M+2 = (Mn, Co, Ni, Cu, Zn, Cd and Hg), X = 2, X = zero for (Co+2 and Hg+2) complexes, (Quin-) = quinaldate ion, (α-Pic) = α-picoline. The results showed that the deprotonated ligand (QuinH) by using (KOH) coordinated to metal ions as bidentate ligand through the oxygen atom of the carboxylate group (-COO-) and the nitrogen ato

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Publication Date
Mon Jul 29 2013
Journal Name
Al- Mustansiriyah J. Sci.
Synthesis and Characterization of Some Mixed Ligand Complexes of Quinaldic Acid and α-Picoline with Some Metal Salts
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Some metal ions (Mn+2, Co+2, Ni+2, Cu+2, Zn+2, Cd+2 and Hg+2) complexes of quinaldic acid (QuinH) and α-picoline (α-Pic) have been synthesized and characterized on the basis of their , FTIR, (U.V-Vis) spectroscopy, conductivity measurements, magnetic susceptibility and atomic absorption. From the results obtained the following general formula has suggested for the prepared complexes [M(Quin)2( α-Pic)2].XH2O where M+2 = (Mn, Co, Ni, Cu, Zn, Cd and Hg), X = 2, X = zero for (Co+2 and Hg+2) complexes, (Quin-) = quinaldate ion, (α-Pic) = α-picoline. The results showed that the deprotonated ligand (QuinH) by using (KOH) coordinated to metal ions as bidentate ligand through the oxygen atom of the carboxylate group (-COO-) and the nitrogen ato

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Publication Date
Sun Mar 06 2016
Journal Name
Baghdad Science Journal
Synthesis and Characterization of Some New Azo Dyes Derivatives Via Chalcone and Study Some of Their Biological Activity
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This work includes synthesis of new six membered heterocyclic rings with effective amino group using the reaction of benzylideneacetophenone (chalcone) (1) with thiourea or urea in alcoholic basic medium to form: 1,3-thiazen-2-amine (2), and 1,3-oxazin-2-amine (8) respectively. The diazotization reaction was carried out with sodium nitrite in presence of hydrochloric acid to form diazonium salts which suffered coupling reaction with naphthols and phenols in the presence of sodium hydroxide to form colored azo dyes (4-7, and 10-13). o-methylation reaction of compounds (7) and (10) yielded : 1,3-thiazin -2-yl-diazenyl (14), and 1,3-oxazin-2-yl-diazenyl (15) respectively.The new compounds were characterized using vario

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Publication Date
Mon Dec 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
اختبار نسبة الامكان لاجل التساوي للمعلمات المحلية لـ لمجتمعات أسية مبنية على نوع لمراقبة العينات
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  • Epstein, B., and sobel , M. (1954)."Some Thearems Relevant to life Testing from an Exponential population" Annals of Mathematical Statistics, 25, 373 – 381 .
  • Epstein, B., and Tsao, C.K.(1953) "Some Tests Based on Order Observation From Two Exponential Populations" Annals of Mathematical Statistics , 24 , 458 – 466 .
  • Hogg, R.V. and Tonis, E,A. (1963), "An Iterated procedure for Testing the Equality of several Exponential Distributions" Journal of the American Statistical Association, 58 , 435 – 443.
  • Kumar, S. , and patel , H. I. (1971) "ATest for the Comparision of two Exponential Disributions" Technometrics , 13 , 183 – 189 .<
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Publication Date
Wed Dec 13 2017
Journal Name
Al-khwarizmi Engineering Journal
Experimental Investigations Performance for (VCC) Using 2-Way (PFCV) Type (2FRE)
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In modern hydraulic control systems, the trend in hydraulic power applications is to improve efficiency and performance. “Proportional valve” is generally applied to pressure, flow and directional-control valves which continuously convert a variable input signal into a smooth and proportional hydraulic output signal. It creates a variable resistance (orifice) upstream and downstream of a hydraulic actuator, and is meter in/meter out circuit and hence pressure drop, and power losses are inevitable. If velocity (position) feedback is used, flow pattern control is possible. Without aforementioned flow pattern, control is very “loose” and relies on “visual” feed back by the operator. At this point, we should examine how this valv

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Publication Date
Fri Dec 01 2023
Journal Name
مجلة تكريت للعلوم السياسية
نوع المكاسب اثرها في التفاعلات التعاونية الدولية: دراسة في انماط سلوكيات الدول حيال التحديات المناخية
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في هذا البحث، تم استكشاف تأثير نوع المكاسب على التفاعلات التعاونية الدولية لاسيما في مجال مواجهة التحديات المناخية. إذ تبين أن المكاسب النسبية تلعب دورا حاسما في توجيه سلوك الدول فيما يتعلق بالاتفاقيات البيئية الدولية. ويعكس هذا التحليل دروسا مهمة لصياغة السياسات والجهود الدولية في هذا المجال ذاته. ان الدول عندما تتوقع مكاسب نسبية تفوق الخسائر المتوقعة من التعاون، فإنها تكون أكثر عرضة للالتزام بالاتفاقيات

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