research centers


Search results: Found 10

Listing 1 - 10 of 10
Sort by

Article
The Effect of Pure Aluminum Weight Percent on Different Properties of a New Cermet Material Made of Al-Machinable Glass Ceramic

Author: Bayda,a Abdul-Hassan Khalaf
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 4 Pages: 805-813
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

In this research high pure aluminum metal with the following weight percent(1,2,3,4,5) has been added to machinable glass-ceramic, after the preparation of thesamples by pressing then firing the effect of this addition on the density, hardness,young modulus, and polishing and grinding time of the machinable glass-ceramichave been studied. It has been found that the increasing in aluminum percent lead toslightly increase in density while the hardness, young modulus, and polishing andgrinding time decreased.


Article
Studying and Modeling The Effects of Quartz Addition and Heat Treatment on Corrosion Properties of Ceramic Coating

Authors: Ali H. Ataiwi --- Ibtihal A. Mahmood --- Jabbar H. mohmmed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 12 Pages: 2564-2579
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

In this work, a new glass-ceramic coating has been developed and applied, as a single coat without prior chemical treatment of the surface, by using the dipping technique on metal substrate. the coating are designed for application on varies grades of low alloy steel, the selected substrate was low carbon low alloyed steel with (0.2)%C. Various heat treatments at temperatures ( 500,550, and 600˚C ) at different times (60 & 120)min and with quartz addition in the range (0-15)% were used to obtain a glass-ceramics that have the optimum coating properties. These coating have been characterized by x-ray diffraction analyses and the results showed presence of a number of microcrystalline phases which are formed during the heat treatments. The results of corrosion resistance tests indicated that the acid resistance was greatly improved by addition of quartz into enamel frit but at same times decreased the alkali corrosion resistance, while the heat treatments improved both acid and alkali resistance for all cases, this is attributed to the formation of complex network from crystalline phases. The results also indicated that the heat treatment at 600˚C for 120min with 15% quartz addition brought the optimum values for acid resistance property which are improved by 86.66%, while the optimum values for alkali resistance property was brought with free quartz added samples which were treated at 600˚C for 120min. Mathematical modeling is implemented and regression equations are obtained by using ( SPSS ) software to predict the experimental data for acid and alkali corrosion rate. Comparing the predicted and measured values gives high prediction accuracy. The accuracy of prediction has been (82.58%, and 96.7%) for acid and alkali resistance properties respectively.


Article
Neural Networks For Estimating The Ceramic Productivity Of Walls

Authors: Ali Sabri Tofan --- Sawsan Rasheed Mohammed
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2011 Volume: 17 Issue: 2 Pages: 200-217
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Productivity estimating of a construction operation is an essential tool for the successful completion of the construction process. Productivity of a construction operation is defined as output of the system per unit of time.In this research Artificial Neural Networks approaches are presented. The main reason for using neural networks for construction productivity estimation is the requirement of performing complex mapping of environment and management factors to productivity.A generic description of the artificial neural networks model is provided, followed by summarized factors that affect ceramic labor productivity, then neural-network model are developed for Estimating ceramic walls productivity, the input data for the model based on experienced superintendents employed by a leading construction general contractor, test results show that the ANN approach can produce a sufficiently accurate estimate with a limited data-collection effort, and thus has the potential to provide an efficient tool for construction productivity estimation.

تخمين الإنتاجية لعملية البناء هي وسيلة أساسية من أجل النجاح في إتمام عملية البناء و تعرف إنتاجية البناء على انها ناتج النظام لكل وحدة من الوقت. في هذا البحث استخدمت الشبكات العصبية الاصطناعية. السبب الرئيسي لاستخدام الشبكات العصبية لتقدير انتاجية البناء هو متطلبات رسم الخرائط المعقدة للبيئة و عوامل ادارة الانتاجية.وضع وصف عام لنموذج الشبكات العصبية الاصطناعية ، يليها تلخيص العوامل التي تؤثر على إنتاجية عمال السيراميك ، ثم طور نموذج من الشبكات العصبية المتقدمة لتخمين انتاجية السيراميك للجدران ، والبيانات المدخلة للنموذج اعتمدت على المراقبين ذوي الخبرة و الموظفين من قبل المقاول العام للانشاء ، تشير نتائج الاختبار الى أن الشبكات العصبية الاصطناعية يمكن ان تؤدي إلى تخمينات دقيقة بما فيه الكفاية مع جهود جمع بيانات محدودة ، وبالتالي فأن الاختبار لديه القدرة على توفير أداة فعالة لتخمين إنتاجية البناء.

Keywords

NEURAL --- NETWORKS --- ESTIMATING --- CERAMIC --- PRODUCTIVITY --- WALLS


Article
Effect of etchant type and the use of silane on the shearbond strength of composite resin to porcelain.

Author: Abdulla MWAl-Shamma عبد الله محمد وجيه الشماع
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2011 Volume: 23 Issue: 4 Pages: 1-6
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Background: This study was formulated to compare the effect of 5%hydrofluoric acid in comparison to37%phosphoric acid with and without the application of silane on bond strength of composite to porcelain.Materials and Methods: Specimen preparation was divided in to two phases, metal-disks fabrication (8mm-diameterand 4mm-thickness) and ceramic veneering. Thirty two specimens were prepared, sandblasted with 50 μm aluminumoxide, and divided into four groups of eight samples. Groups I and III were etched with 37%phosphoric acid whilegroups II and IV were etched with 5%hydrofluoric acid; and groups I and II were silaneted while groups III and IV werenot. Heliobond, and resin composite were applied to each specimen using a plastic transparent split mold (4mmdiameterand 4mm-height). Specimens were stored in distilled water for 24 hours then thermocycled for 100 cycles.Shear bond strength was determined by a Zwick universal machine at a cross-head speed 5 mm/minute.Results: Mean shear bond strength values were 21.02(group I), 23.31(group II), 4.00(group III), and 18.60(group IV).Paired-t revealed that specimens treated with 5%hydrofluoric acid were significantly higher than those treated with37%phosphoric acid regardless the use of silane. The use of silane dramatically enhanced the bond strength ofcomposite resin to porcelain for both acids. All specimens treated with 37%phosphoric acid without silane showedadhesive failure, while those treated with 5%hydrofluoric acid showed mostly cohesive failure within ceramic.Conclusion: Silane improved the shear bond strength of composite to ceramic, and hydrofluoric acid performedgreater bond strength compared to phosphoric acid.


Article
Studying The Effect of Zircon Dioxide on The Corrosion Resistance of Porcelain Enamel
دراسة تأثير أوكسيد الزركونيوم على مقاومة تأكل الطلاء البورسليني

Author: Nagham Salman Hassan نغم سلمان حسن
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2011 Volume: 14 Issue: 2 Pages: 189-198
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

Among various coating systems for industrial and engineering applications, glass–ceramic coatings have advantages of chemical inertness, high temperature stability and superior mechanical properties such as abrasion, impact etc as compared to other coating materials. Besides imparting required functional properties such as heat, abrasion and corrosion resistance to suit particular end use requirements, the glass–ceramic coatings in general also provide good adherence, defect free surface and refractoriness. This research tends to produce a cheep and effective glass- ceramic coating from glass cullet and different percent of crystallization agents ZrO2, and study the final corrosion resistance properties of them. After several set of acid resistance testing at temperatures range (25, 50, 75,100,125 oC) it has been found that porcelain enamel with (4 wt %) ZrO2 has the best acid corrosion resistance.

من ضمن انظمة الطلاء المختلفة للتطبيقات الهندسية والصناعية, طلاءات الزجاج السيراميكي لها ميزة المقاومة الكيميائية, والاستقرارية في درجات الحرارة العالية والخواص الكيميائية المدهشة مثل القشط, والصدمة الى اخره مقارنة مع مواد الطلاء الاخرى. اضافة الى باقي الخواص الضرورية للاغراض التطبيقية مثل الحرارة , مقاومة القشط , والتاكل لتلائم متطلبات التطبيق النهائية, طلاءات الزجاج السيراميكي بصورة عامة توفر التصاقية جيدة وسطح خالي من العيوب وعازل حراريا. هذا البحث يهدف الى انتاج طلاء من الزجاج السيراميكي يكون فعالا ومنتج من مخلفات الزجاج ونسب مختلفة من عامل التبلور ZrO2, ودراسة خواص مقاومة التاكل النهائية. بعد سلسلة متعددة من اختبارات مقاومة الحامض في درجات حرارية تتراوح بين (25, 50, 75,100,125 oC) وجد ان الطلاء ذو (4% نسبة وزنية) من ZrO2 له احسن مقاومة تاكل.


Article
The Effect of (á-Al2O3) Volume Fraction on The Mechanical Properties of (Al-Alumina) Metal Matrix Composite

Authors: Fawziea M. Hussien --- Baydaa Abdul-Hassan Khalaf
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 13 Pages: 2765-2772
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

This research tends to study the effect of change in volume fraction of alpha phase alumina on mechanical properties of a metal matrix composite specimens contain (Al- áAl2O3). Specimens were prepared with the following volume fractions (10, 15, 20, 25, 30, 35, 40, and 45). Then effectof this change on hardness, maximum stress and strain,Young’s modulus, impactand wear resistance has been studied. Results of testing showed that while hardness, maximum stress, Young’s modulus, and impact strength increased markedly with volume fraction of alumina, wear rate, and maximum strain decreased with increasing of volume fraction.


Article
Study the Mechanical Properties of Epoxy Resin Reinforced With silica (quartz) and Alumina Particles
دراسة الخواص الميكانيكية للايبوكسي المدعم بدقائق سليكا (كوارتز) والالومينا

Loading...
Loading...
Abstract

AbstractIn this work the mechanical properties of polymer composites reinforced with ceramicparticulates are investigated. The epoxy resin used as a Matrix material is Ep-10 and thereinforcement particulate materials are silica with particle size (53-63)μm and alumina withparticle size (106-150)μm ,and having weight fraction of 20%, 30% and 40% respectively.Specimens of the matrix material and the six types of composite materials were subjected totensile, compression, bending, impact and hardness tests. Experimental tests results indicatethat the composite materials have significantly higher modulus of elasticity than the matrixmaterial. It was found that the enhancement in modulus of elasticity is directly proportional tothe weight fraction of reinforcement material and that alumina composites have higher modulusof elasticity than silica composites with equivalent weight fraction .The highest modulus ofelasticity is that of the composite with 40 % alumina, which is 182% higher than that of thematrix material. The tensile and bending strength of the matrix material were found to besignificantly higher than those of the composite material while composites with 30% and 40%weight fraction reinforcement martial have marginally higher compressive strength than thematrix material. Test results also indicate that material toughness, fracture toughness andhardness of the composite materials are significantly higher than those of the matrix material.The enhancements in these properties are found to be directly proportional to the weightfraction of reinforcement materials. These properties of composites reinforced with alumina aresignificantly higher than that of composites reinforced with equitant silica(quartz) content. Thehighest material toughness, fracture toughness and hardness are that of the composite with 40%alumina.

س I>? اg>K LMA@P YVHg? اد @SA Y>I>ZSA اص ا @A ا YK درا jSF<=>?@AB 53-63 ) وا )μm m>PVo Qp_P JUA ا T ھ Q>ROeJA Y?OeUSA اد ا @SA وا Ep- ع 10 @Z TUH@VWB ا@ ھس R 20 . %- 30%- اره % 40 Ot? TZ وز gUIP 150-106 ) و )μm m>PVo Qp_Pرات SeF YVH اgeSA اد ا @SA ت ان ا g€ أظ Y>JSiA ا‚??@AB ا LMROeA ا YAo <=>?@A ٠40% ا YVU=


Article
Effect of SiC particles and water absorption on thermal conductivity of epoxy reinforcement by (bi-directional) glass fiber
تأثير دقائق كاربيد السليكون وامتصاص الماء على التوصيلية الحرارية للايبوكسي المدعم بالياف الزجاج المتعامدة الاتجاه

Authors: A. A. Kareem أسيل عبد الأمير كريم --- H. I. Jaafar حارث ابراهيم جعفر
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2011 Volume: 9 Issue: 14 Pages: 13-17
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

In this study the thermal conductivity of the epoxy composites were characterized as function of volume fraction, particle size of fillers and the time of immersion(30,60,90)days in water .Composites plates were prepared by incorporating (bi-directional) (0º-90º) glass fiber and silicon carbide (SiC) particles of (0.1,0.5,1)mm as particle size at (10%,20%,30%,40%) percent volume in epoxy matrix. The composites shows slightly increase of the thermal conductivity with increasing volume fraction, particle size and increase with increasing the days of immersion in water. The maximum thermal conductivity (0.51W/m.K) was obtained before the immersion in water at 90 days for epoxy reinforcement by bi-directional glass fiber and SiC particles with volume fraction 40% and particle size 1mm .

في هذا البحث تمت دراسة التوصيلية الحرارية لمتراكب الايبوكسي واعتمادها على كل من الكسر الحجمي, الحجم الحبيبي لمواد التدعيم. كما تم دراسة تأثير الغمر بالماء لفترات ( (30,60,90يوم على التوصيلية الحرارية.حضرت الواح المتراكب باضافة الياف الزجاج المتعامدة التجاه ( (0º-90ºودقائق SiC ذات الحجم الحبيبي (0.1,0.5,1) mm والكسر ألحجمي (10%,20%,30%,40%) كمواد تدعيم والايبوكسي كمادة اساس.اظهرت النتائج ان التوصيلية الحرارية تزداد بزيادة كل من الكسر الحجمي والحجم الحبيبي لمواد التدعيم كما تزداد عند تنقيعها بالماء لفترات اطول .وان اعظم توصيلية حرارية كانت لمتراكب الايبوكسي المدعم بالياف الزجاج المتعامدة وبدقائق كاربيد السيلكون ذات الكسر الحجمي ( (40%والحجم الحبيبي ) (1mmوالمغمورة في الماء لفترة 90 يوم.


Article
Fatigue Behavior of Al – 4wt%Cu / SiCP and Al - 4wt%Cu/ Al2O3P Composites
Al2O3 و SiC مدعمة بحبيبات ( Al + 4wt%Cu) سلوك الكلل للمواد المتراكبة ذات اساس من سبيكة

Author: Salim Aziz Kako سالم عزيز كاكو
Journal: AL Rafdain Engineering Journal مجلة هندسة الرافدين ISSN: 18130526 Year: 2011 Volume: 19 Issue: 6 Pages: 54-61
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

AbstractAluminum – copper ( Al – 4wt%Cu ) alloy metal matrix composites MMCs reinforced with 0.5 ,1.0 ,1.5 % wt of both SiC and Al2O3 particles were fabricated by stir-casting .The effects of SiC and Al2O3 particles content on the fatigue behavior of the Al – 4wt%Cu unreinforced base alloy and the resulted composites were investigated. The results show that fatigue strengths of base alloy increased with increasing weight fractions of ceramic particles and the fatigue strength of MMCs reinforced with SiC particles is higher than that of reinforced with Al2O3 particles

الخلاصةيهدف البحث الحالى الى دراسة سلوك الكلل لسبيكة ( Al + 4wt%Cu ) المقواة بدقائق كاربيد السليكون SiC و دقائق الالومينا Al2O3 و بنسب وزنية مختلفة ( 0.5 , 1.0 , 1.5 )% . استخدمت طريقة السباكة بالمزج stir –casting، لتصنيع المواد المتراكبة . بعد ذلك اجريت فحص الكلل على العينات القياسية لكل من سبيكة الاساس و المواد المتراكبة . اظهرت نتائج فحص الكلل ان المادة المتراكبة تمتلك قيم مقاومة الكلال اعلى مقارنة بالسبيكة الاساس و تزداد هذه القيم مع زيادة نسب دقائق السيراميكية المضافة . اما تأثير نوعية المادة السيراميكية على تلك الخاصية فقد لوحظ زيادة ملحوظة في قيم مقاومة الكلل للمادة المتراكبة المقواة بدقائق كاربيد السليكون مقارنة مع المادة المتراكبة المقواة بدقائق الالومينا .


Article
The Effect Of Temperature On The Dielectric Strength Of BaTiO3 Ceramic
تأثير درجة الحرارة على متانة العزل لمادة الباريوم تيتانيت BaTiO3

Author: Dr. Jassim Mohammed Yaseen د. جاسم محمد ياسين
Journal: College Of Basic Education Researches Journal مجلة ابحاث كلية التربية الاساسية ISSN: 19927452 Year: 2011 Volume: 10 Issue: 3 Pages: 604-614
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

In this work , barium titanate ( BaTiO3) ceramic was prepared using two systems (BaO- TiO2) , (Ba acetate-TiO2) by solid state reaction method . X-ray diffraction patterns showed that the ( BaO- TiO2) prepared BaTiO3 ceramic was a good growth when it calcimine at 1200 C for 2 hr . But (Ba acetate –TiO2) prepared BaTiO3 was a bad growth at 1200 C ,hence it requires calcimine temperature above 1200 C Using optical microscopy, the particle size and shape for each powder has been noted . The results of dielectric strength measurements showed that the dielectric strength strongly depend on the temperature , in which the dielectric strength decrease as temperature increase with more significant above 120 C .

في هذا العمل تم تحضير مادة الباريوم تيتانيت BaTiO3 باستخدام النظامين(BaO-TiO2) و (Ba acetate-TiO2) وباستخدام طريقة الحالة الصلبة. فحوصات حيود الاشعة السينية XRD اظهرت ان مادةBaTiO3 المحضرة باستخدام النظام (BaO-TiO2) لها درجة نمو جيدة عند حرقها بدرجة حرارة 1200 C لمدة ساعتين بينما لم يكتمل نمو مادة BaTiO3 المحضرة باستخدام النظام( ( Ba acetate-TiO2 . عند حرقها بدرجة حرارةC 1200 .نتائج قياسات متانة العزل اظهرت ان متانة العزل تعتمد بشكل كبير على درجة الحرارة ، حيث ان متانة العزل تنخفض بزيادة درجة الحرارة ويزداد معدل الانخفاض في درجات الحرارة فوق C 120 .

Listing 1 - 10 of 10
Sort by
Narrow your search

Resource type

article (10)


Language

English (9)

Arabic and English (1)


Year
From To Submit

2011 (10)