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Article
Effect of silver nitrate on some mechanical properties of heat polymerizing acrylic resins

Authors: Assiss. Prof. Dr. Sabiha Mahdi د. صبيحة مهدي --- Dr. Firas Abd K. Abstract Aim: د. فراس عبد كاطع
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2017 Volume: 14 Issue: 1 Pages: 110-117
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Aim: The aimed study was to evaluate the influence of silver nitrate on surfacehardness and tensile strength of acrylic resins.Materials and methods: A total of 60 specimens were made from heat polymerizingresins. Two mechanical tests were utilized (surface hardness and tensile strength)and 4 experimental groups according to the concentration of silver nitrate used.The specimens without the use of silver nitrate were considered as control. Fortensile strength, all specimens were subjected to force till fracture. For surfacehardness, the specimens were tested via a durometer hardness tester. Allspecimens data were analyzed via ANOVA and Tukey tests.Results: The addition of silver nitrate to acrylic resins reduced significantly thetensile strength. Statistically, highly significant differences were found among allgroups (P≤0.001). Also, the difference between control and experimental groupswas highly significant (P≤0.001). For surface hardness, the silver nitrate improvedthe surface hardness of acrylics. Highly significant differences were statisticallyobserved between control and 900 ppm group (P≤0.001); and among all groups(P≤0.001)with exception that no significant differences between control and150ppm; and between 150ppm and 900ppm groups(P>0.05).Conclusion: The addition of silver nitrate to acrylics reduced significantly the tensilestrength and improved slightly the surface hardness.


Article
Tensile Strength of Core Build up Material to Glass Fiber Post with Different Surface Treatment

Author: Eman M. Yahya
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2017 Volume: 17 Issue: 1 Pages: 1-11
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: The purpose of this study was to investigate the effects of different surface treatments on the tensile retentive force of fiber reinforced posts (FRPs) to composite core material buildup. Materials and methods: A total of fifty FRPs were randomly divided into five groups (n = 10), the first group was the untreated control group, second group immersion in 24% hydrogen peroxide; third group immersion in 4% hydrofluoric acid gel; fourth group sandblasting with 50um Al2O3 powder, fifth group surface preparation with an Er:YAG laser under power setting (300m), at 2 Hz and 100 uS) for 10 seconds. A cylindrical polyethylene mold was used to surround the treated posts, and the mold was filled with dual cure composite core material buildup. All samples were light cured for 40 seconds through the top of the mold. After 24 hours of storage in water, the post was then grasped with Jacobs chuck attached to the upper member of testing machine and produced tensile loading. Tensile tests were performed at a cross, head speed of 0.5 mm/minute using a universal testing machine. Data were analyzed by One-Way Analysis of Variance followed by Duncan Multiple Range Test at significant difference (p < 0.05). Results: The post core tensile retentive force achieved following pretreatment with hydrogen peroxide and sandblast (Groups 2 and 4) were comparable to each other, and significantly higher than those of other groups in which the post surface had been treated with hydrofluoric acid gel, control group and laser, respectively. Conclusions: surface pretreatment of FRP has significance effect on the tensile retentive force. Sandblasting and hydrogen peroxide are increasing tensile retentive force of FRPs to composite core material buildup greater than those of hydrofluoric acid gel, control and laser group, respectively.


Article
Preparation and Characterization of PMMA-HDPE and HDPE-PMMA Binary Polymer Blends

Authors: S.I. Salih --- A.M. Al.gabban --- A.H. Abdalsalam
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 4 Part (A) Engineering Pages: 311-317
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

A comparison was made on the mechanical characteristics of binary blends polymethylmethacrylate/ high density polyethylene (PMMA-%HDPE) and vice versa. Analysis of morphology by SEM has been also accomplished. Preparation of polymer blends was performed using melt mixing method by an extruder. Tensile results showed that binary polymer blends (PMMA-%HDPE) indicated an increment in ultimate tensile strength, elastic modulus and shore D hardness compared to (HDPE-%PMMA). The blend of 95%PMMA- 5%HDPE shows superior mechanical properties. SEM results indicated that the prepared blends are not fully compatible with some separated phases of the second polymer dispersed in the matrix.


Article
Influence of Using White Cement Kiln Dust as Mineral Filler on Hot Asphalt Concrete Mixture Properties

Authors: Talal H. Fadhil, --- Salah S. Jasim --- Khalil E. Aziz, --- Ahmed S. Ahmed
Journal: Anbar Journal of Engineering Sciences مجلة الأنبار للعلوم الهندسية ISSN: 19979428 Year: 2017 Volume: 7 Issue: 2 Pages: 148-157
Publisher: University of Anbar جامعة الانبار

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Abstract

The White Cement Kiln Dust (WCKD) is a byproduct material, formed in cement factory during the operation of cement production. In highway construction, the WCKD can be used in different ways such as stabilizing the subgrade of highway embankment and as mineral filler in Hot Mix Asphalt (HMA); the latter usage will give clean and healthy environment in addition to more economy. In Iraq, there are two common types of fillers, Portland cement and lime stone powder. In this research, WCKD taken from Fallujah cement plant used as mineral filler in addition to two common types. Various percentages , such as 100%WCKD, 50%WCKD + 50%Cement(C) ,100%C , 50%WCKD+50%Limestone (L), and 100% L, were used to prepare asphaltic concrete mixes. In general, five tests were used to evaluate the performance of these mixes. Standard Marshall Test procedure was applied under three different conditions, two of them at two temperatures at 60 OC and 70 OC and in the third one it was used to test samples immersed in water, at room temperature(24 OC), for four days. Indirect Tensile Strength Test (ITST) was used to evaluate conditioning and un-conditioning samples. All test results, when compared with controlled asphalt concrete sample (Sample contained 100% limestone as filler), were acceptable and within the AASHTO and Iraqi Standard Specifications of Roads & Bridges 2003. Stability values, at standard condition test, of samples containing 100% WCKD, 50%WCKD+50%C, and 50%WCKD+50%L are 11.9kN, 13.2kN, and 14.0kN respectively, while for controlled sample was 9.0kN. The Marshall stiffness values showed similar trends, for samples having 100% WCKD, 50%WCKD+50%C, and 50%WCKD+50%L giving 3.22kN/mm, 3.38kN/mm, 3.5kN/mm respectively but for controlled sample was 2.43 kN/mm. Same trends of results gained in ITST .The results showed the beneficial using of WCKD as filler that will conserve the environment and encourage the HMA producers to use this inexpensive material in their works.


Article
MECHANICAL PROPERTIES FOR ORDINARY CONCRETE CONTAINING WASTE PLASTIC FIBERS
الخصائص الميكانيكية للخرسانة الاعتيادية التي تحتوي على الفضلات البلاستيكية

Authors: Khalil Ibrahim Aziz خليل ابراهيم عزيز --- Huda Al Moqbel kuhair هدى مقبل قهير
Journal: Iraqi Journal of Civil Engineering المجلة العراقية للهندسة المدنية ISSN: 19927428 Year: 2017 Volume: 11 Issue: 2 Pages: 33-44
Publisher: University of Anbar جامعة الانبار

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Abstract

This study program has been conducted to investigate the influence of adding waste plastic fibers (WPF) resulting from manual cutting for bottles used in the conservation gassy beverage on different characteristics of ordinary concrete.Cutting plastic waste by volumetric rates ranging between (0.5%) to (2%) was approved. Reference mix was produced for comparison. Tests were conducted on the models produced from waste plastic fiber concrete like compressive strength, flexural strength and splitting tensile strength. The analysis of the results showed that the use of plastic waste fibers (1%) has led to improve the properties of flexural strength and splitting tensile strength compared with reference concrete .When the( 0.75%)WPF ratio improved the compressive strength as compared with the control specimen . Compressive strength in (28 days) with fiber ratio (0.75%) WPF is higher than equal (5.1%) from compressive strength in (28 days) of reference concrete. Volumetric ratio (1%) WPF can be also observed that each of the flexural strength and splitting tensile strength increases equal (12.5 and 12.5%) respectively, from flexural strength and splitting tensile strength for the reference mix at(28day).

يتضمن هذا البحث دراسة الخصائص الميكانيكية للخرسانة الحاوية على فضلات بلاستيكية الناتجه من التقطيع اليدوي للقناني البلاستيكية المستخدمة في حفظ المشروبات الغازية ولقد تم اعتماد الياف الفضلات البلاستيكيه بنسب حجمية مختلفه تتراوح من(0.5%-2%)حيث ان.0.75% اعطت اعلى مقاومة انضغاط و1% اعطت اعلى مقاومة شد مع انتاج خرسانه اعتياديه مرجعيه لغرض المقارنة. وتم اجراء الفحوصات على النماذج المنتجة من الخرسانة الحاوية على فضلات الالياف البلاستيكية كفحوصات مقاومة الانضغاط ومقاومة الانثناء ومقاومة الشد بلانشطار ولقد اظهر تحليل النتائج ان استخدام الياف الفضلات البلاستيكة بنسبة (0.75%) ادى الى تحسين مقاومة الانضغاط بنسبة (5.1%) مقارنة مع الخلطة المرجعية بعمر 28 يوم.وكذلك يمكن ملاحظة بان كل من مقاومة الانثناء ومقاومة الشد بلانشطار تزداد بمقدار(12.5%)و(12.5%) على التوالي من مقاومة الانثناء والشد بالانشطار للخلطه المرجعية.


Article
Improvement, the Performance of Polyurethane (PUR), Y-290 Resin as Coating of Oil Pipeline by Using Multi-Walled Carbon Nanotubes (MWCNTs)

Authors: S.A. Awad --- E.M. Khalaf
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 8 Part (A) Engineering Pages: 845-848
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, polyurethane epoxy-Y290 (PUR-Y290) as a matrix material was reinforced by 1%MWCNTs. Polyurethane is a thermoset polymer and using for several applications particularly as coatings of gas and oil pipeline. Polyurethane uses as a liquid coating against the corrosion, and that is caused by the direct exposure for long periods of UV irradiation and humidity. The nanocomposites were prepared by adding 1wt% MWCNTs to polyurethane and mixed by using an ultrasound mixer. Polyueethane-1%MWCNTs composite sample was exposed to accelerate weathering (UV irradiation coming from sunlight, moisture, and salt water spray) during the exposure to different durations 6 months, 12 months and 24 months. Exposed and unexposed samples were investigated and evaluated by thermal and mechanical tests.It was found that the incorporation 1.0%wt of MWCNTs filler, enhanced the thermal stability and improved the mechanical properties during the exposure for long-term life to accelerated weathering conditions, compared with polyurethane coating without MWCNTs filler. These results indicated that polyurethane (liquid coating) nanocomposites have a higher resistance to environmental condition and give more protective against corrosion of oil pipelines and applied as coatings by spray method to protect the oil pipeline surfaces from environmental conditions.


Article
Effect of Addition CuO Nanoparticle to Quenching Media on Properties of Medium Carbon Steel

Author: J.H. Mohmmed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 9 Part (A) Engineering Pages: 894-898
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In current work the effect of addition CuO nanoparticles to the polyalkylene glycol (PAG) water solution quenching media on some properties of medium carbon steel was examined. Five cooling media was used to quenching the steel: water, 5 and 10 % water solution of polyalkylene glycol, and 5 and 10 % water solution of polyalkylene glycol with addition of 1% of CuO nanoparticles. In addition, in this study, the cooling curves for these media and the properties of tensile and affect for quenched and unquenched medium carbon steel were studied and evaluated. The results showed that the addition of CuO nanoparticles strongly improve the quenching media features and contribute to reduce water quenched sample defects (such as distortion and cracking), while at the same time still maintaining the desired mechanical property improvements. The experimental observations indicate that samples quenched 5% polyalkylene glycol water solution of with 1% CuO nanoparticles brought the best combination of mechanical properties.


Article
Investigation on Tensile Strength Ratio (TSR) Specimen to Predict Moisture Sensitivity of Asphalt Pavements Mixture and Using Polymer to Reduce Moisture Damage

Author: Mohammed Aziz Hameed Al-Shaybani
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2017 Volume: 25 Issue: 2 Pages: 732-743
Publisher: Babylon University جامعة بابل

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Abstract

Moisture damage of asphalt concrete is defined as losing the strength and Permanence caused by the active presence of moisture.The most common technique to reduce moisture damage is using modifiers with the asphalt binder or the aggregate.The goal of this study was to explore the effect of various modifiers of polymer on the moisture susceptibility mixture of asphaltic concrete pavement. Modifiers included in this research selected two kinds of polymers Crumb Rubber No 50 (CR No 50) and Methyl Methacrylates (MMA(which are available in the local markets in Iraq and have been used in three percentages for each type. These percentages are (5, 10 and 15)% for (CR No 50) and (2.5, 5 and 7.5(% for (MMA).Each type of these polymers is blended with asphalt by wet process at constant blending times for a suitable range of temperatures. The experimental works showed that all polymers modified mixtures have indirect tensile strength higher than control asphalt mixtures, its about (2-15) %, dependent on different type of polymer and polymer concentration under predicted suitable blending time.Test results of indirect tensile strength indicated betterment in modifying the proprieties of mixture, the increased resistance mixture of asphalt concrete pavement versus moisture damage, and reduced the effect of water on asphalt concrete properties. The final result is the addition of (10% CR No 50) and (5% MMA) to asphalt mixtures showed an improved mixture of asphalt concrete properties and produced strong mixtures for road construction.One model is predicted for tensile strength ratio [TSR]to estimate the effects of polymer modification on moisture susceptibility mixture of asphalt concrete.

يعرف الضرر الناتج بسبب الرطوبة في الخرسانة الاسفلتية بفقدان القوة والمتانه بسبب وجود محتوى رطوبي فعال, الاسلوب الاكثر شيوعا للتخفيف والحد من ضرر الرطوبة هو استخدام المعدلات مع الاسفلت او مع الركام. ان الهدف من هذه الدراسة هو دراسة تأثير المعدلات المختلفة من اللدائن (البوليمرات) على تاثروحساسية خلطة الخرسانة الاسفلتية بالرطوبة, وقد تم اختيار المعدلات الواردة في هذه الدراسة هي نوعين من اللدائن (البوليمرات) المطاط الناتج عن سحق الإطارات المستعملة (CR) والاكرلات ((MMA المتوفرين في الأسواق المحلية وتم استخدامها بثلاثة نسب مختلفة لكل نوع هي (5, 10, 15)% من ال (CR)و بنسب (2.5, 5, 7.5)% من ال MMA)), كل نوع من هذه البوليمرات خلط مع الاسفلت بواسطة عملية الخلط الرطبة وبأوقات ثابة محددة سابقا وبدرجات حرارة معينة. واظهرت التجارب المختبرية ان جميع الخلطات المعدلة بالبوليمر تمتلك مقاومة شد غير مباشر اعلى من الخلطات الاسفلتية الاعتيادية الغير معدلة بحوالي من %(2-15) تعتمد على نوع البوليمر وتركيز البوليمر تحت زمن خلط متوقع ومناسب, ان نتائج اختبار مقاومة الشد غير المباشر تبين تحسن خصائص المزيج المعدل وبالتالي زيادة مقاومة الخرسانة الاسفلتية للأضرار الناتجة بسبب الرطوبة وتقليل تأثير الماء على خواص الخرسانة الاسفلتية, وكنتيجة نهائية، إضافة 10٪ ((CR رقم 50 و 5% (MMA) لمخاليط الأسفلت أظهرت تحسين خصائص خلطات الخرسانة الإسفلتية وإنتاج خليط يمتلك ديمومة جيدة عند انشاء الطرق.موديل احصائي واحد متوقع للنسبة المؤية لمقاومة الشد (TSR) لتخمين تأثير التعديل بالبوليمر عل تحسس تأثير الرطوبة على خلطة الخرسانة الاسفلتية.


Article
Effect of Pin Shape and Rotational Speed on the Mechanical Behaviour and Microstructures of Friction Stir Spot Welding of Aa6061 Aluminum Alloy

Authors: Mujtaba A. Fliayyh مجتبى عبد الكاظم فليح --- Sadeq H. Bakhy صادق حسين باخي --- Mohsin N. Hamzah محسن نوري حمزة
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2017 Volume: 20 Issue: 1 Pages: 129-139
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Friction stir spot welding (FSSW) is a modern solid-state joining process able to weld similar and dissimilar overlap joints in different classes of materials and is widely being considered for automotive industry. In this work, the mechanical behavior ) i.e. tensile shear tests, Microhardness(, and microstructure of friction stir spot welded joints were studied for AA6061-T6 aluminum alloy sheets with thickness of 1.6 mm. Series of FSSW experiments were conducted using vertical CNC milling machine type "C-tek". FSSW is carried out at different pin profiles (cylindrical, taper, and triangular) and tool rotational typically speeds, i.e. 800, 1000, 1200 and 1400 rpm. Based on the welding experiments conducted in this study, the results show that sheets welded by triangular pin tool have highest tensile shear load, of 3.2 kN, followed by welds with cylindrical pin, while welds made using taper pin has the tensile shear load 2.1 kN at optimum speed of 1200 rpm. Also the pin shape and rotational speed had an obvious effect on microstructural parameters i.e. hook height and bond width.

اللحام بالخلط الاحتكاكي النقطي من طرق لحام الحالة الصلبة الحديثة قادرة على لحام وصلات التراكب متشابهة والمتباينة في أصناف مختلفة من المواد التي تستخدم بشكل واسع في صناعة السيارات. في هذا العمل,تم دراسة الخصاص المكانيكية (حمل قص الشد, الصلادة الدقيقة( والبنية المجهرية لوصلات صفائح سبيكة الألمنيوم A6061-T6 الملحومة بالخلط الاحتكاكي النقطي ذات سمك(1.6) ملم. تم تنفيذ التجارب بواسطة ماكنة تفريز عامودية نوع C-tek. تم اجراء اللحام الاحتكاكي النقطي لثلاث اشكال مختلفة لراس عدة اللحام مثلث ودائري ومخروطي وعند اربعة سرع دورانية عملية (800 , 1000, 1200 , 1400 دورة بالدقيقة). استنادا إلى التجارب التي أجريت في هذه الدراسة، أظهرت النتائج أن صفائح الملحومة بواسطة راس اداة اللحام ذات مثلثة الشكل لديها أعلى حمل لشد القص (3.2kN) تليها الصفائح المحلحومة بواسطه راس اداة اللحام اسطوانية الشكل,في حين حققت اللحامات باستخدام لراس عدة اللحام مخروطية الشكل ادنى حمل لشد القص(2.1kN) عند السرعة المثلى (1200 دورة في الدقيقة(. كذلك شكل راس اداة اللحام وسرعة الدوران لهما تأثير واضح على ارتفاع الخطاف وعرض الرباط.


Article
The Effects of Long-Term Operation and High Temperature on Material Properties of Austenitic Stainless Steel Type 321H
تأثير العمر التشغيلي لفترات زمنية طويلة على الخصائص لسبيكة الفولاذ المقاوم للصدأ الاوستنايتي من النوع 321H والتي تعمل بدرجات حرارة عالية

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Abstract

Changes in mechanical properties of material as a result of service in different conditions can be provided by mechanical testing to assist the estimation of current internal situation of these materials, or the degree of deterioration may exist in furnaces serviced at high temperature and exceed their design life. Because of the rarity works on austenitic stainless steel material type AISI 321H, in this work, ultimate tensile strength, yield strength, elongation, hardness, and absorbed energy by impact are evaluated based on experimental data obtained from mechanical testing. Samples of tubes are extracted from furnace belong to hydrotreaterunit, also samples from un-used tube material are used to make comparisons between these properties. Tensile properties of stainless steel (AISI 321H) were decreased as temperature increases; the trend of properties decreasing for the samples of un-used tube material is the same for the ex-used material. The trend of stress-strain curve will not change due to elevated temperature exposure for long time of service, except the yield strength will be higher in this diagram. The yield strength increased under these conditions, but the ability of material which is elongated will decrease. Hardness and absorbed energy increased by 11.28 and 14% respectively when the material is aged for long time under effect of high temperature accompanied with creep effect.

التغيرات الحاصلة في الخصائص الميكانيكية للمواد نتيجة للظروف المختلفة في أثناء خدمتها يمكن الحصول عليها عن طريق الاختبارات الميكانيكية، بحيث يمكن الاستعانة بالتغيرات الحاصلة للخصائص في تقدير حالة هذه المواد ودرجة الضرر المتولدة فيها وكمثال للجانب التطبيقية أنابيب الأفران الحرارية التي تعمل بدرجات حرارية عالية ولمدة عمرية تتجاوز العمر التصميمي لها. ولندرة البحوث التي تستخدم سبيكة الفولاذ المقاوم للصدأ الاوستنايتي 321H في دراستها فقد تم دراسة هذه الخصائص مثل متانة الخضوع، متانة الشد، الاستطالة، الصلادة، والطاقة الممتصة أثناء الصدمة بالاعتماد على نتائج الاختبارات العملية. فقد تم تقطيع نماذج من هذه السبيكة مستخدمة في صناعة أنابيب فرن حراري عائد لوحدة هدرجة النفثا في مصفى الدورة للحصول على عينات اختبارية، فضلا عن دراسة نماذج جديدة من نوع السبيكة نفسها لأغراض المقارنة بين النتائج. بزيادة درجة حرارة اختبار الشد لحالتي النماذج الجديدة والمستخدمة سابقا اظهرت نقصان في متانة الشد، وقد اظهرت عينات حالتي المعدن المستخدم وبدرجة الحرارة نفسها الاختبار تصرف متماثل لمنحني الاجهاد-الانفعال مع زيادة في متانة الخضوع لحالة المعدن المستخدم سابقة، مع نقصان في القدرة على الاستطالة نتيجة التحميل في حالة العينات ذات العمر التشغيلي الطويل عنها في العينات الجديدة، وحصول زيادة في كل من الصلادة والطاقة الممتصة من قبل المعدن قبل حدوث الكسر بمقدار (11,28%) و (14%) على التوالي لحالة العينات ذات العمر التشغيلي الطويل مقارنتا مع العينات الجديدة.

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