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Article
The effect of SOLO and sodium hypochlorite disinfectant on some properties of different types of dental stone

Authors: Aseel M. Al-khafaji اسيل الخفاجي --- Shorouq M. Abass شروق عباس --- Bayan S. Khalaf بيان خلف
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2013 Volume: 25 Issue: 2 Pages: 8-17
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Dental casts come into direct contact with impression materials and other items that are contaminatedby saliva and blood from a patient's mouth, leaving the casts susceptible to cross-contamination. The disinfectantsolutions of the impression materials cause various adverse reactions. Therefore, disinfection of dental casts may beeffective in preventing cross infection. This study was carried out to evaluate the surface hardness, dimensionalaccuracy, reproduction of details and surface porosity of type III, type IV and type IV extra hard dental stone afterimmersion in and spray by using SOLO and Sodium hypochlorite disinfectant solutions.Materials and methods: 240 Stone samples were prepared in rubber rings, A total of 60 test block were prepared foreach test (surface hardness, dimensional accuracy, reproduction of details and surface porosity).the samples weredivided into three groups (20 for each type of stone) type (III, IV, IV extra hard); SOLO and Sodium hypochloritedisinfectant by 2 methods (immersion and spray) were used in each test.Results: the results of dimensional accuracy, reproduction of details, surface hardness and surface porosity revealedno significant difference for all types of tested stone samples after immersion or spraying in SOLO and NaOCl exceptthe surface hardness of type IV extra hard showed significant difference after spray with SOLO and the surfaceporosity of type IV extra hard showed significant difference after immersed in both SOLO and NaOCl solutions.Conclusions: Based on the results of this study immersion in and spray by using SOLO and NaOCl disinfectant solutionsproduced no adverse effect on dimensional accuracy, reproduction of details, surface hardness and surfaceporosity for type III, type IV dental stone and for type IV extra hard dental stone except for the surface hardness fortype IV extra hard when sprayed with SOLO and the surface porosity when type IV extra hard stone immersed in theSOLO and NaOCl solutions


Article
Effect of the Electrode Angle on the Optical Properties of Electrostatic Immersion Lens
تأثير زاوية القطب على الخواص البصرية للعدسة الكهروستاتيكية المغمورة

Author: Rana W. Al-Hialey رنا وليد الحيالي
Journal: Rafidain journal of science مجلة علوم الرافدين ISSN: 16089391 Year: 2013 Volume: 24 Issue: 6A Pages: 134-146
Publisher: Mosul University جامعة الموصل

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Abstract

Two models of an electrostatic immersion lenses of double electrodes have been designed of equal diameter and pole thickness, at different distances between their electrodes for the upper and lower parts. Each model includes two lenses according to its electrode angle that varied. The effect of variation of the single electrode angle was studied for each lens on the optical properties at a constant voltage ratio. An optimum electrode angle has been chosen for the lenses one with a lowest spherical and chromatic aberration coefficients in order to compared its optical properties at different voltages ratio at zero magnification condition. It was found that the lenses E1and E3 are better than E2 and E4 in the two models. Moreover, it was found that E3 has an optimum optical performance within the two models. The results of the optical properties of the electrostatic lenses in the present work have been compared with those of the published results. A great improvement in the optical performance of the considered lenses has been found

تم تصميم نموذجين من العدسات الكهروستاتيكية المغمورة ثنائية القطب ذات قيم متساوية من أقطار وأسماك أقطابها وتختلف في المسافة بين قطبيها للجزئين العلوي والسفلي. ويشمل كل نموذج عدستين طبقاً لموقع القطب الذي تتغير فيه قيمة زاوية القطب. ودُرِس تأثير تغيير زاوية قطب منفرد لكل عدسة من هذه العدسات الأربعة على خواصها البصرية عند نسبة جهد ثابتة. واختيرت أفضل زاوية قطب التي حققت أوطأ معاملات زيوغ كروية ولونية لكل من العدسات الأربعة لمقارنة الخواص البصرية في حالة التكبير الصفري لهذه العدسات عند نسب جهود مختلفة، ووجد في النموذجين أن العدستين E1 و E2 أفضل من كلا العدستين E3 و E4، وتبيّن ان العدسة E3 هي الفضلى للنموذجين والتي حققت أوطأ قيم للتغير النسبي لكلا الزيغين الكروي واللوني نسبة إلى البعد البؤري. وتمت مقارنة نتائج الخواص البصرية للعدسات الكهروستاتيكية للبحث الجاري مع نظيراتها للبحوث المنشورة، ووجد أن هنالك تحسناً واضحاً في الأداء البصري للعدسات المقترحة.


Article
The Effect of Bore Diameters in Two Electrodes Electrostatic Immersion Lens Design
تأثير أقطار فتحة القطبين على تصميم العدسات الكهروستاتيكية ثنائية القطب المغمورة

Authors: Muna A. Al-Khashab منى عبد الكريم الخشاب --- Abdullah E. Al-Abdullah عبد الله ادريس عبد الله
Journal: Rafidain journal of science مجلة علوم الرافدين ISSN: 16089391 Year: 2013 Volume: 24 Issue: 2E Pages: 82-91
Publisher: Mosul University جامعة الموصل

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Abstract

The paper handles a new method that is utilized in determining the best bore diameter of two electrodes of the electrostatic lens design. However, the bore diameter is considered the most important geometrical parameter in any electron optical device. Accordingly, the immersion electrostatic lens have been designed and its electron optical properties were calculated for different bore diameters of the two electrodes to determine their optimum value. Also the study is concerned with the equal values of the bore diameter for the two electrodes, and the ratios of their first to the second bore diameters found including the calculated value of the optimum bore diameter. It was found that the best electron optical properties were obtained when the ratio of the bore diameters for the electrostatic lens is approximately equal (0.66).

يتناول هذا البحث طريقة جديدة لإيجاد افضل قيمة لقطر فتحة القطبين في تصميم العدسة الكهروستاتيكية. ويعد قطر فتحة القطبين اهم عامل هندسي لأية أداة بصرية الكترونية. ووفقا لذلك صُمّمت عدسة الكتروستاتيكية مغمورة، وتم احتساب خواصها البصرية الالكترونية لقيم مختلفة من اقطار فتحة القطبين لإيجاد القيمة المثلى. شملت الدراسة قيما متساوية من اقطار فتحة القطبين، ووجدت نسبة قطر فتحات قطبها الاول الى قطبها الثاني بالاعتماد على القيمة المثلى لقطر فتحة القطبين المحسوبة. تبين ان افضل خواص بصرية الكترونية تم الحصول عليها عند نسبة قطر فتحة قطبي العدسة الكهروستاتيكية تساوي تقريبا (0.66).

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