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ijp-965
The Confinement Profile Effect on the Optical Properties in Different Inverse-shaped Single InGaN/GaN Quantum Wells
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In this work, the effects of size, and temperature on the linear and nonlinear optical properties in InGaN/GaN inverse parabolic and triangular quantum wells (IPQW and ITQW) for different concentrations at the well center were theoretically investigated. The indium concentrations at the barriers were fixed to be always xmax = 0.2. The energy levels and their associated wave functions are computed within the effective mass approximation. The expressions of optical properties are obtained analytically by using the compact density-matrix approach. The linear, nonlinear, and total absorption coefficients depending on the In concentrations at the well center are investigated as a function of the incident photon energy for different values of temperature and quantum wells size. The results show that the In concentrations, size and temperature have a significant effect on these optical properties. The positions of the resonance peaks of the absorption coefficients were blue-shifted under increasing indium compositions in the quantum wells (InGaN) and temperature while they were red-shifted with the increase in the thickness of the wells. Moreover, the amplitudes of the resonance peaks were enhanced under the increase of the In composition, the temperature, and the thickness of the quantum wells. The optical absorption in ITQW structure is slightly greater than that in IPQW one.

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Publication Date
Thu Feb 01 2018
Journal Name
Applied Energy
Solidification enhancement of PCM in a triplex-tube thermal energy storage system with nanoparticles and fins
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Publication Date
Tue Dec 11 2018
Journal Name
Iraqi Journal Of Physics
Spectroscopic and structural studies of cadmium oxide thin films prepared by D.C magnetron sputtering
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Cadmium oxide thin films were prepared by D.C magnetron plasma sputtering using different voltages (700, 800, 900, 1000, 1100 and 1200) Volt. The Cadmium oxide structural properties using XRD analysis for just a voltage of 1200 volt at room temperature after annealing in different temperatures (523 and 623) K were studied .The results show that the films prepared at room temperature have some peaks belong to cadmium element along the directions (002), (100), (102) and (103) while the other peaks along the directions of (111), (200) and (222) belong to cadmium oxide. Annealed samples display only cadmium oxide peaks. Also, the spectroscopic properties of plasma diagnostic for CdO thin films were determined and the results show that the el

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Publication Date
Thu Apr 01 2021
Journal Name
Basra Journal Of Science
Preparation and Characterization of Polyvinylpyrrolidone/Multi-walled Carbon Nanotubes Nanocomposite hybrid with Graphene
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In this work, polyvinylpyrrolidone (PVP), Multi-walled carbon nanotubes (MWCNTs) nanocomposite was prepared and hybrid with Graphene (Gr) by casting method. The morphological and optical properties were investigated. Fourier Transformer-Infrared (FT-IR) indicates the presence of primary distinctive peaks belonging to vibration groups that describe the prepared samples. Scanning Electron Microscopy (SEM) images showed a uniform dispersion of graphene within the PVP-MWCNT nanocomposite. The results of the optical study show decrease in the energy gap with increasing MWCNT and graphene concentration. The absorption coefficient spectra indicate the presence of two absorption peaks at 282 and 287 nm attributed to the π-π* electronic tr

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Publication Date
Sun Jun 20 2021
Journal Name
Baghdad Science Journal
Comparison of Some of Estimation methods of Stress-Strength Model: R = P(Y < X < Z)
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In this study, the stress-strength model R = P(Y < X < Z)  is discussed as an important parts of reliability system by assuming that the random variables follow Invers Rayleigh Distribution. Some traditional estimation methods are used    to estimate the parameters  namely; Maximum Likelihood, Moment method, and Uniformly Minimum Variance Unbiased estimator and Shrinkage estimator using three types of shrinkage weight factors. As well as, Monte Carlo simulation are used to compare the estimation methods based on mean squared error criteria.  

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Publication Date
Wed Feb 11 2026
Journal Name
Kufa Journal Physical Education Sciences
اثر تدريبات بأسلوب التدريب الدائري لبناء التحمل في تطوير بعض القدرات الحركية لأشبال لكرة القدم بأعمار (13- 15) سنة
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اهمية البحث هي مرحلة نمو وبناء اجهزة الجسم للاعبين الاشبال واعداد تدريبات بأسلوب التدريب الدائري لبناء التحمل لتطوير بعض القدرات الحركية والمهارية لدى اللاعبين الاشبال بكرة القدم , حيث لاحظت الباحثة ضعف في مستوى الاداء الحركي ارتأت اعداداً بدنيا ومهارياً منذ مرحلة البناء الأولى للاعب الفئات العمرية , واستخدم الباحث المنهج التجريبي بالاختبار القبلي والبعدي للمجموعتين التجريبية والضابطة لملائمته لطبيعة ال

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Publication Date
Mon Dec 01 2008
Journal Name
Journal Of Economics And Administrative Sciences
خطة الصيانة الوقائية ومحاكاتها على وفق معايير هندسة المعولية دراسة حالة في الشركة العامة للصناعات الجلدية - معمل رقم 7-
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This research is an attempt to study and evaluate the maintenance function at Factory 7 - The State General Company for Leather Industries, and to design a computerized preventive maintenance system to design and to analyze preventive  maintenance.  To accomplish the objectives of this research, data were gathered and analyzed according to the reliability engineering criteria for the period 2/1– 30/6/2005, then a preventive maintenance plan was designed for each machine of the sample study using the computerized system designed in this research. A Monte Carlo Simulation methodology was used for the purpose of evaluating the performance of the preventive maintenance plan of each machine for one year. The simulation res

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Publication Date
Tue Feb 02 2021
Journal Name
جامعة واسط مجلة كلية التربية
استعمال الانموذج اللوجستي ثنائي المعلم في بناء وتدريج مقياس الشخصية الافتراضية المتعدد الابعاد لطلبة الجامعة وفقا لنظرية الاستجابة للفقرة
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تهدف الدراسة الحالية الى استعمال الانموذج اللوجستي ثنائي المعلم في تدريج مقياس الشخصية الافتراضية المتعدد الابعاد لطلبة الجامعة وفقا لنظرية الاستجابة للفقرة، والخروج بتعميم لنتائج البحث والوقوف على الاجراءات العلمية المناسبة وتوفير تطبيق عملي علمي صحيح لاعتمادها من قبل الباحثين. وقد اتبعث الباحثة الاسلوب العلمي من خطوات واجراءات في عملية بناء المقياس حيث حدت ابعاد الشخصية الافتراضية المتمثلة بسبع ابعا

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Publication Date
Fri Feb 28 2025
Journal Name
مجلة علوم التربية الرياضية - جامعة بابل
تأثير تدريبات الثبات المحوري بالانقباض المتحرك في التوازن المتحرك والقوة المميزة بالسرعة للرجلين والمناولة المتوسطة للاعبين الشباب بكرة القدم
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هدف البحث إلى إعداد تدريبات الثبات المحوري باالنقباض المتحرك لالعبين الشباب بكرة القدم، والتعرف على تأثير تدريبات الثبات المحوري باالنقباض في التوازن المتحرك والقوة المميزة بالسرعة للرجلين والمناولة المتوسطة لالعبين الشباب بكرة القدم، واعتمد المنهج التجريبي بتصميم المجموعتين ً التجريبية والضابطة على عينة بلغت )24 ( العبا بأسلوب ً من فئة الشباب بكرة القدم اختيرت عمديا الحصر الشامل وبنسبة )100 %( من نادي الشرط

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Publication Date
Thu Nov 02 2023
Journal Name
الدراسات اللغوية والترجمية
استراتيجية التثاقف في الترجمة الادبية بين الحفاظ على الموروث الحضاري والاندماج المجتمعي رواية فرايم ... فرايم للقاص شالوم درويش (انموذجا)
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الملاخص كامل

Publication Date
Sun Jul 06 2014
Journal Name
Journal Of Educational And Psychological Researches
أصول التربية : تضارب المحتوى وإشكالية الإعداد دراسة نقدية لكتب ومقررات أصول التربية في الجامعات العربية ووضع تصور منهاجي بديل
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Research questions  start from the fact that what the Arab origins of education  indicted . First question are :

- To what extent the subject of assets acquired a specific meaning in the Arabic books and educational subjects ? Is these selections are reflected on the classification of assets and their types ?
- What’s the nature of the content ? .Is there a consistency between the meaning and content ?

- What entrances handling and curriculum approach and tactics are in those books ?

- Is the assets subject introduced within  the grade  best suited ?

         &nb

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