The semiconductor ZnO is one of II – VI compound group, it is prepare as thin films by using chemical spray pyrolysis technique; the films are deposited onto glass substrate at 450 °C by using aqueous zinc chloride as a spray solution of molar concentration 0.1 M/L. Sample of the prepared film is irradiating by Gamma ray using CS 137, other sample is annealed at 550°C. The structure of the irradiated and annealed films are analyzed with X-ray diffraction, the results show that the films are polycrystalline in nature with preferred (002) orientation. The general morphology of ZnO films are imaged by using the Atomic Force Microscope (AFM), it constructed from nanostructure with dimensions in order of 77 nm.
The optical properties of the prepared films are studied by using measurement from UV-VIS-NIR spectrophotometer at wavelength within the range (300-900) nm. The optical results show that the absorption of the prepared films are decreases after annealing and increases after irradiation. The optical constants such as the refractive index and the photoconductivity are calculated before and after annealing as a function of the photon energy. Also the values of the optical energy gap are calculated, it is 3.3 eV and 3.1 eV for the direct and indirect allowed transition respectively; these values are reduced after annealing.
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Background: The demand for better esthetic during orthodontic treatment has increased nowadays, so orthodontists starting using esthetic arch wires, brackets and ligatures.Tooth colored brackets were introduced in different types of materials. Sapphire ceramic brackets are one type of esthetic brackets and their color stability remains the main concern for the clinicians and patients at the same time. The present study design to evaluate the effect of three different staining materials (pepsi, black tea and cigarette smoke) on the stainability of sapphire ceramic brackets bonded with three types of light cure orthodontic adhesives which include: Resilience, Enlight and Transbond. Materials and Methods: The sample consisted of three hundre
... Show MoreThe study aims to investigate the degree of student teachers at Sultan Qaboos University acquired skills in teaching Arabic via a virtual micro-teaching lab, as well as to reveal the difficulties they faced and their development proposals. To do this, the researchers developed a questionnaire divided into four dimensions: planning, implementation, evaluation, and
ethical values for the teaching profession, in addition to two open-ended questions to identify difficulties and suggestions. It was administered to (30) student teachers. The results revealed that the average degree of student-teacher acquisition of skills was high in its four dimensions. It ranged between (39.2) to (82.2), while the overall average was (56.2).
... Show MoreThe present research included sampling and analysis of 41 soil samples , the samples cover various areas of Nasiriyah city (industrial,commercial,residential and agricultural ) to estimate pollution levels of lead element and determine the correlation between lead concentration and natural factors in soil which represent sedimentary organic matter content, granular gradient, clay minerals and non-clay minerals . The results of the current study showed that the average concentration of lead in the soil samples was 61.12 ppm , it was noticed an increase in the concentration of lead in environmental components in the area of this study especially in residential , industrial and commercial location and the impact of natural factors of the so
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The condition of Islam and Muslims and what their political, social, cultural and educational status, and even religious and faith status, has led to whoever feels his belonging to this great religion and that middle nation, to try as much as he can to fix what has been corrupted as much as he can, and perhaps in diagnosing illness and illness as It was said half the way to treatment, and from this standpoint I liked to occupy thought, work consideration and harness part of the youth’s life in order to reach what contributes to reforming the situation and the safety of generations, and this is only in seeking knowledge and learning it by following the guidance of the Messenger (r) and his companions ( y) Therefore, the subject of my re
... Show MoreLanguages were not found in our life in a way utter coincidence , and it’s not flounce on people’s tongue randomly ‚ but laws are the controlling in languages‚ these laws could be lift to the same level of natural laws‚ phonetics form the main part in producing those languages‚ the Arabic language is one of those languages ‚ it’s largest dialects in Arabian Peninsula according to speakers number ‚ Arabic language link with these dialects through properties and phenomena sound and grammar‚ from this point my topic search is came Similar and different between Arabic and Arabian peninsula Accents balance linguistic–study voice of the Seine typically ) . and Similar and different of the ph
... Show MoreIn the Rumaila oilfields in southern Iraq, the Zubair Formation was deposited in a shallow environment as three main facies, delta plain, backshore, and delta front depositional conditions indicating a transition from delta front and delta plain to a highstand level due to the finning upward mode. The facies of the Zubair clasts show well-sorted quartz arenite sandstone, poorly sorted quartz arenite sandstone, clayey sandstone that has not been properly sorted, sandy shale, and shale lithofacies. The minor lithofacies were identified using well-logging methods (gamma ray, spontaneous potential and sonic logs) and petrography. The Zubair clasts are of transition environment that appears to be transported from freshwater and deposited
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لقد كان حرص المؤلف على إصدار هذا الكتاب نابعا ً من قناعة تامة بأن مجال التقويم والقياس بحاجة إلى كتاب علمي حديث يتناول عرض أدوات الاختبار والقياس والمتمثلة بالصدق والثبات ويتسم بالوضوح في التعبير عن المفاهيم والمصطلحات والأنواع لكل منها ليكون وسيلة مبسطة بأيدي الأساتذة والباحثين وطلبتي الدراسات العليا الماجستير والدكتوراه لإستخراج صدق وثبات الاختبارات والمقاييس بطرق إحصائية متقدمة من خلال إستخدام البرنا
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