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Pulsed Er,Cr:YSGG Laser For Surface Modification of Dental Zerconia Ceramic
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Background: Surface treatment of machined dental zirconia for enhancement of the adhesion to resin cement, using Er,Cr:YSGG  Laser. Materials and Methods: Total number of 42 zirconia disc specimens (9 mm diameter, and 2 mm height) was sintered according to the manufacturer instruction. They are divided into six groups, each group of seven samples. Laser groups (Experiment parameters) were depend on laser total irradiation time, pulse duration, and power. Group (A): 20 sec., 60 µs pulse duration. Group (B): 30 sec., 60 µs pulse duration. Group (C): 40 sec., 60 µs pulse duration. Group (D): 20 sec., 700 µs pulse duration. Group (E): 30 sec., 700 µs pulse duration, with different powers used (1, 1.50, 2, 2.50, 3, 3.50, 4) W. And finally group (N): untreated samples representing the control group. Luting cement was applied to laser treated zirconia sample’s surfaces and cured by light for 40 s. Then all sample surfaces were examined under a stereo microscope, for determining the depth mean values of the created pulse holes, for each specimen. The bond between the laser treated zirconia surfaces and the applied resin cement, were examined for all samples by using a universal testing machine, for determination of the shear bond strength values. Six additional specimens: one untreated sample and five other samples that were laser irradiated with the parameters that exhibited the highest shear bond strength values in each treated group, were examined for their average surface roughness by using an atomic force microscope. Another similar six specimens were also examined for their surface morphology, by using a scanning electron microscope. Both surface examination methods were performed by specialized operators. The bond failure modes were also examined by an optical microscope. Results obtained from shear bond strength test and laser pulse depth examination were statistically analyzed. Results: There was significant differences in the shear bond strength values, indicating a clear increase in zirconia-resin cement bonding, especially in group B (30 s, 60 µs, 4W), reaching  (8.63 Mpa). Whereas, the control group had (4.49 Mpa), and an enhanced zirconia surface average roughness, that group E (30 s, 700 µs, 3.5 W) specimen had the highest value (14.5nm), among the six examined specimens. While the control specimen had the least value examined which is (3.05nm). Conclusion: A relation between the cement bonding efficiency and the laser treated zirconia surface roughness, laser pulse depths was detected. The Er,Cr:YSGG laser pulse duration and  power is  crucial parameters in the surface roughness enhancement of the zirconia ceramic.

 

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Publication Date
Wed Mar 20 2024
Journal Name
Journal Of Petroleum Research And Studies
Advanced Machine Learning application for Permeability Prediction for (M) Formation in an Iraqi Oil Field
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Permeability estimation is a vital step in reservoir engineering due to its effect on reservoir's characterization, planning for perforations, and economic efficiency of the reservoirs. The core and well-logging data are the main sources of permeability measuring and calculating respectively. There are multiple methods to predict permeability such as classic, empirical, and geostatistical methods. In this research, two statistical approaches have been applied and compared for permeability prediction: Multiple Linear Regression and Random Forest, given the (M) reservoir interval in the (BH) Oil Field in the northern part of Iraq. The dataset was separated into two subsets: Training and Testing in order to cross-validate the accuracy

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Publication Date
Sat Dec 30 2023
Journal Name
Nasaq
Quantum computers are opening new horizons for an advanced and changing future for the world
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This study addresses quantum computers as one of the most significant contemporary technological transformations that promise to reshape the future of global computing. It aims to clarify the conceptual foundations of quantum computing and to identify the fundamental differences between quantum and classical computers in terms of processing mechanisms, computational speed, and the ability to solve highly complex problems. The study focuses on key concepts such as the qubit, superposition, and entanglement, highlighting their role in enabling computational capabilities that exceed the limits of classical computing. It also discusses the future applications of quantum computers in areas such as cryptography, artificial intelligence, big data

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Publication Date
Mon Mar 15 2004
Journal Name
Sciences Journal Of Physical Education
Setting standards for some offensive skill abilities according to basketball playing positions for Iraqi youth
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لا يزال المهتمون بلعبة كرة السلة يبحثون عن إيجاد الوسائل الأكثر أهمية وصولاً إلى ما تطمح إليه الدول لتحقيق افضل المستويات في نواحي اللعبة كافة من خلال التغلب على المعوقات التي تحول دون تقدمها إلى الأمام بالدراسة والبحث. ومن هذا المنطلق انصب البحث في ضرورة معالجة القصور الناتج عن عدم وجود المعايير ذات العلاقة باختبارات قدرات اللاعبين وعلى وفق مراكز اللعب ولا سيما المهارية الهجومية مما شكل ذلك ضعفاً في أعداد و

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Publication Date
Sun Jan 01 2017
Journal Name
البحوث التربويةوالنفسية
Preparing a teacher’s guide for computer books for the intermediate stage according to learning styles
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Publication Date
Sun Oct 27 2024
Journal Name
Thi-qar University Journal Of Physical Education Sciences
Arab participation and achievements for men in the Summer Paralympics for the period (2004-2012)
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This research addresses the necessity due to the scarcity of historical studies in the field of sports, especially those indicating the activities and achievements of Arab countries in the Paralympic movement. This study aims to document the participation of Arab countries in the Paralympic Games, explore the prominent sports in which Arab athletes with disabilities participated, and analyze their achievements during the Paralympic Games from 2004 to 2012. The research methodology adopted an analytical, historical approach, collecting and analyzing data objectively through the official website of the International Paralympic Committee, in addition to scientific and historical sources from research papers, journals, and websites. The key fi

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Publication Date
Tue Nov 03 2020
Journal Name
Modern Sport
Effect of using flat hierarchical method on some aspects of muscular strength and straight serve skill for nascent tennis players
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The researcher focused on the importance of the physical abilities of the tennis game, as this game is one of the games that are characterized by its specificity in performance as this game is characterized by continuous movement and dealing with different elements, so this game requires the development of muscle strength, which plays an important role in Performance skills in the game of tennis. There are several methods to develop strength, including flat hierarchical technique, which is one of the most common forms of training in the development of muscle strength.     As for the research problem, the researcher found a method that has an effect on the development of force. Therefore, the researcher tried to diversify a

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Publication Date
Sun Sep 26 2021
Journal Name
Modern Sport
The effect of special exercises in developing the strength endurance of the arms of the national team players with the goal ball for the blind
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The importance of the research lies in preparing an experimental curriculum according to a scientific method that will contribute to the development of the special strength(endurance the strength of arms) in order to contribute to the attempt to develop the basic skills of the national team players ‏with the goal ball for the blind ‏As for the research problem, it lies in the weakness of the strength endurance of the national team players with the goal ball for the blind, as the research problem is clearly evident in the last minutes of the match, as well as the former studies in the field of goal ball game for the blind at the country level ‏The research aims to prepare special exercises for endurance of strength as well as t

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Publication Date
Mon Sep 01 2025
Journal Name
Environmental Engineering Research
Green polymer nanocomposite membranes for treating oily wastewater: A comprehensive review
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This review highlights recent advances in the development and use of eco-friendly polymeric membranes made from polymer blends for treating oily wastewater, a major source of environmental pollution. Among treatment options, membrane separation stands out because of its high efficiency and ability to selectively remove oil from water using semi-permeable barriers. The focus of this review is on polymeric membranes derived from polymer blends, which show improved mechanical strength, thermal stability, and resistance to fouling. Additionally, the role of nanomaterials such as titanium dioxide, graphene oxide, and iron nanoparticles is discussed for their ability to boost membrane porosity, permeability, and oil separation efficiency.

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Publication Date
Wed Mar 30 2022
Journal Name
Journal Of Educational And Psychological Researches
The Degree of Availability of Moral Values in the Arabic Language Textbook (Al-Mu’nes) For Grades Eleven and Twelve For Post-Basic Education in The Sultanate of Oman
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          The current study aimed to reveal the moral values available in the Arabic language textbook (Al-Mu’nes) for   grades eleven and twelve for post-basic education in the Sultanate of Oman. The researcher adopted the descriptive approach using the sentence as measuring unit in the analysis process. The five fields of moral values and their subcategories values represented the categories of the analysis. Iterations of values and the percentages of iteration were calculated in those textbooks. Moreover and the analysis and stability of the process were confirmed.

         After referring to previous studies, it was possible to de

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Publication Date
Wed Dec 25 2019
Journal Name
Separation Science And Technology
Green synthesis of graphene-coated sand (GCS) using low-grade dates for evaluation and modeling of the pH-dependent permeable barrier for remediation of groundwater contaminated with copper
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