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Article
INVESTIGATION OF LOAD EFFECTS AND TEMPERATURES ON RATE OF WEAR USING BRASS AND CARBON STEEL MATERIALS.

Author: Dr. Ahmed A. Al.kafaji & Talib H. Rashid
Journal: Iraqi journal of mechanical and material engineering المجلة العراقية للهندسة الميكانيكية وهندسة المواد ISSN: 20761819 Year: 2013 Volume: 13 Issue: 3 Pages: 458-466
Publisher: Babylon University جامعة بابل

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Abstract

The study was done to predict rates of wear which occurred as a result of friction process between a brass material and a carbon steel disc was rotated with speed equal to 675 r.p.m. The wear rates were calculated for a dwell time equal to 30 minutes for each case of applied loads of 250g, 750g and 1250g. This research investigated the effects of loads applications on the variation in temperatures which were taken place due to rubbing action at contact area that may play role in specifying the wear rates. These results have indicated the style of wear rates expressed by volume and by weight that may be a guide for the designers when using those materials at similar friction conditions

تمت الدراسة للتنبؤ بمعدلات البلى نتيجة احتكاك مادة البراص و قرص الفولاذ الكار بوني الذي يدور بسرعة 675 دورة/دقيقة . تم حساب معدلات البلى لفترة 30 دقيقة لكل حالة بعد تسليط اثقال مختلفة ( 250غم, 750 غم, 1250غم ). في هذا البحث تم التحقيق في تاثيرات الاحمال على التغير في درجات الحرارة الحاصل نتيجة الاحتكاك والذي قد يكون لها دور في تحديد معدلات البلى. و قد أشارت النتائج إلى انماط لمعدلات البلى وقد تم التعبير عنها بدلالة الحجم وكذلك بدلالة الوزن. ان هذه المؤشرات تشكل دليلا يساعد المصممين عند اختيار هذه المواد في ظروف احتكاك مشابهة.


Article
Dental Wear Its Prevalence and Patterns in Class I Malocclusion (A Comparative Study)

Author: Kasem Ahmed Abeas
Journal: Medical Journal of Babylon مجلة بابل الطبية ISSN: 1812156X 23126760 Year: 2015 Volume: 12 Issue: 3 Pages: 828-835
Publisher: Babylon University جامعة بابل

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Abstract

Dental wear is a physiological process that occurs normally through a variety of mechanisms and age progression. It is aloss of tooth structure during masticatory forces. The study aimed to investigate patterns of tooth wear in adult with class I malocclusion (crowding) then the normal occlusion is compared with them. Our study sample consisted of 2 groups with an age range “18-25” years.The 1rstgroupwas (30 subject) with normal occlusion and the 2nd was (30 subject) with class I crowding. A modified version of the tooth wear index (TWI) was used to assess the amount of tooth wear.Tooth wear was greater statistically in incisal surfaces of central incisors of the upper arch and lateral incisors of both arches in class I malocclusion group than was in group of normal occlusion. While significant tooth loss was found in the buccal surfaces of the lower 1rst molar and the incisal surfaces of upper canines in normal occlusion than it was in crowding group. It was concluded that the irregularity of the dentition in class I malocclusion subjects lead to the differences in the pattern of tooth wear in both the normal and malocclusion groups.


Article
Tooth attrition patterns in a group of Iraqi adults sample with different classes of malocclusion (A comparative study)

Authors: Issam M. Abdullah عصام عبد الله --- Ausama A. Al- Mulla اسامة احمد الملا
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 2 Pages: 114-119
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Tooth attrition is wearing away of tooth structure during mastication. This study investigated tooth wearpatterns in adults with different classes of malocclusion and compared them with normal occlusion.Materials and methods: The sample consisted of 363 subjects that were divided into 5 groups with an age range “18-25” years: 85 normal occlusion, 128 class I with crowding, 90 class II division 1, 30 class II division 2 and 30 class III.Dental wear was assessed by using a modified version of the tooth wear index.Results:1. The class I malocclusion group had statistically greater tooth wear in incisal surfaces of maxillary central and lateralincisors, and mandibular lateral incisors than did the normal occlusion.2. The class II division 1 group had statistically greater tooth wear in the occlusal surfaces of maxillary secondpremolars, mandibular first and second premolars. Buccal surfaces of mandibular canines, mandibular secondpremolars and mandibular first molars than did the normal occlusion.3. The class II division 2 malocclusion group had statistically greater tooth wear in labial surfaces of mandibularcentral and lateral incisors. Buccal surfaces of mandibular second premolars, mandibular first molars. Occlusalsurfaces of maxillary first and second premolars and mandibular second premolars than did normal occlusion.4. The class III malocclusion group had statistically greater tooth wear in the occlusal surfaces of maxillary first andsecond premolars than did normal occlusion.Conclusion: In conclusion subjects with normal occlusion and those with different classes of malocclusions havedifferent tooth wear patterns


Article
Automated Visual Inspection of Cutting Tool Wear
الفحص المرئي المؤتمت لبلى عدد القطع

Authors: Ali Abbar Khleif --- Ali Kareem Alwan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2015 Volume: 33 Issue: 6 Part (A) Engineering Pages: 1442-1449
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Nowadays, CNC machines have high importance in manufacturing factories and workshops due to its high accuracy and flexibility. Unfortunately it still cannot ensure the quality of machined products. The trend towards automation in machining has been driven by the need to maintain high product quality with improving production rate. These improvements can be possible by monitoring and control of machining process, in this research a new algorithm is introduced for the direct measurement of cutting tool wear by vision system on the basis of edge detection and morphological operations for the captured images. The results showed the efficiency of the proposed method for online monitoring of the tool condition.

في الوقت الحاضر , تحظى مكائن القطع المبرمجة باهمية كبيرة في المعامل والورش التصنيعية بسبب دقتها العالية ومرونتها لكن لسوء الحظ لا تزال هذه المكائن غير قادرة على التاكد من جودة السطوح المنتجة . الاتجاه نحو اتمتة عمليات القطع سُير للحاجة الملحة للحصول على جودة عالية للمنتجات وتحسين معدل الانتاج . هذه التحسينات تصبح ممكنة عند المراقبة والسيطرة على عملية التشغيل . في هذا البحث تم اقتراح خوارزمية جديدة للقياس المباشر لبلى عدة القطع بواسطة نظام رؤية على اساس تقنية ايجاد الحواف وعمليات المعالجة المورفولوجية للصور الرقمية الملتقطة . اضهرت النتائج المستحصلة كفاءة الخوارزمية المقترحة لمراقبة بلى العدة اثناء العمل.


Article
Computer Aided Flank Wear Measurement in End Milling Cutting Tool

Authors: Ali Abbar Khleif --- Mostafa Adel Abdullah
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 5 Part (A) Engineering Pages: 959-972
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Flank wear width is generally recognized as the key indicator for tool life.In the experiments of this study, nine tools made of HSS and stainless steel 316L as work piecewiththreespindlespeeds(550,930 and 1100)rpm and three redial depth of cut (1.5,2 and 2.25)mm were used. The cutting tool wear was measured using optical microscope and vision system based on a proposed algorithm.Maximum and minimum percentage errors in the flank wear width were (8.250% and 0.645 %) respectively. The numerical method used was by a multiple linear and polynomial regression model and developed a polynomial model, especially to predict the flank wear using MATLAB software.Maximum and minimum percentage errors werefound (14% and 0.322 %) respectively.


Article
Investigation of the Tribological Behavior of Eutectic Al-Si Casting Alloy

Author: Riyadh Azzawi Badr
Journal: Tikrit Journal of Engineering Sciences مجلة تكريت للعلوم الهندسية ISSN: 1813162X 23127589 Year: 2017 Volume: 24 Issue: 3 Pages: 42-46
Publisher: Tikrit University جامعة تكريت

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Abstract

The effect of roughness of Al-Si alloy on the wear is investigated. Roughness average (Ra) was verified via different polishing, also was using a pin–on-disc of different loads (5, 10, 15) N, different speeds (100, 200, 300) rpm and relative humidity 74%. Different values of Ra are obtained with (3, 5 and 7) µm. Worn surface were characterized using SEM / EDX. The results show that the wear rate of Al-Si eutectic alloys increases with the roughness increase. It was noticed that the specific and wear decreases as roughness decreases. Severe wear was observed at all loads.


Article
Effect of Heat Treatments on Sliding Wear Behavior of Medium Carbon Steel
تاثير المعاملات الحرارية على سلوك البلى الانزلاقي لفولاذ متوسط الكاربون

Author: Ahlam Abdalamir Mohamed احلام عبدالامير محمد علي
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2012 Volume: 30 Issue: 13 Pages: 318-328
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The aim of this work is to study the effect of heat treatments on the wear rate ofthe medium carbon steel which included normalizing and different quenchingmedia (air, oil, salt solution at concentration %25). Quenching Include heating toa temperature of 870Co and then rapid cooling. A Pin -on-Disc technique was usedto measure the wear rate under dry sliding conditions with applied and differentsliding times with constant sliding speed of disc (641 r.p.m) and hardness of thesteel disc (48 HRC).The results show that the wear rate increases with applied loads, and withincreasing sliding time for all heat treated specimens it was found that the hardnessvalues of the quench specimens at salt solution is higher than that of normalizedspecimens and quenched specimens in the oil.

تضمن هذا البحث دراسة تاثير المعاملات الحرارية على معدل البلى الانزلاقي لفولاذمتوسط الكاربون وهي المعادلة والتقسية باوساط تقسية مختلفة (الزيت، محلول ملحيبتركيز 25 %). وتضمنت التقسية التسخين عند درجة حرارة ( 870 ) م° ثم التبريد السريع لكللقياس معدل البلى (Pin – on Disc) العينات المقساة ، وقد استخدمت تقنية المسمار على القرصتحت ظروف الانزلاق الجاف وعند تسليط احمال مختلفة وتثبيت زمن الانزلاق ، وفترات انزلاقHRC ) مختلفة مع تثبيت سرعة الدورانية للقرص( 641 ) دورة/دقيقة وصلادة القرص الفولاذي48 ). وقد اظهرت النتائج ان معدل البلى يزداد بزيادة الحمل المسلط والفترة الزمنية للانزلاقلجميع العينات المعاملة حراريا واظهرت النتائج ان قيم الصلادة للعينات المقساة بالمحلول الملحياعلى من العينات المقساة بالزيت والعينات المعاملة بالمعادلة.


Article
Distribution of tooth wear among institutionalized residents (50-89 years old) in Baghdad city Iraq (Cross-sectional study)

Authors: Mohammed G. Al-Azawi محمد العزاوي --- Sulafa K. El-Samarrai سلافة خالد السامرائي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 1 Pages: 180-183
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Tooth wear is one of the most common problems in the older dentate population which results from theinteraction of three processes (attrition, abrasion and erosion) and it affects all societies, different age groups, and allcultures. This study was achieved to evaluate the prevalence and distribution of tooth wear among institutionalizedresidents in Baghdad city Iraq.Subjects and Methods: This survey was accomplished on four private and one governmental institution in Baghdadcity. One-hundred twenty three (61 males, 62 females) aged 50-89 years were participated in this study. The diagnosisand recording of tooth wear were according to criteria of Smith and Knight.Results: The prevalence of tooth wear was 100% with a mean (30.79± 19.39) and median (28). The highest grade oftooth wear recorded was grade 2 (56.9%), followed by grade 3 (26%), grade 4 (17.1%). There was no statisticallysignificant difference of total tooth wear among age groups (P>0.05), astatistically significantdifference was seenregarding the severity of tooth wear among different age groups; for grade 2 and grade 4 (P <0.05), while astatistically highly significant difference recorded for both grade 1 and grade 3. A statistically highly significantdifference of the total tooth wear was recorded between the total males and females (P <0.01).Conclusion: The occurrence of tooth wear among those subjects was high thus they need oral health policy makersfor promotion, prevention and restorative care


Article
BIT DULLNESS EVALUATION FOR THREE DRILLED WELLS IN ZUBAIR FIELD BY USING DIMENSIONLESS PARAMETERS
استخدام المعاملات عديمة الوحدات لتقييم استهلاك الحافرة لثلاثة ابار محفورة في حقل الزبير

Author: Rafid Kadhem Abbas رافد كاظم عباس
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2009 Volume: 2 Issue: 2 Pages: 439-458
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

The present paper deals with using a useful method to monitor the wear of the teeth of milled tooth bits during drilling. This approach is done by using two dimensionless parameters TD (dimensionless torque) and RD (dimensionless rate of penetration) . By plotting TD vs. RD , The constants a1 and a2 could be determined and both used to calculate the two other dimensionless parameters ED (bit efficiency) and FD (bit dullness) as a bit dullness evaluation indicators , which could be used rather than other traditional techniques. This approach applied on three wells , Zubair #166 , Zubair #162 and Zubair #174 in Zubair field Southern Iraq .The obtained results could be useful to detect bit wear and according to that, the decision of pulling and using new bits could be determined easily and therefore drilling operations will be actively done with lowest costs and efforts. .

البحث المقّدم يتعامل مع استعمال طريقة مفيدة لمراقبة استهلاك أسنان الحافرات أثناء الحفر . هذه الطريقة تتم بواسطة استخدام حّدين عديمي الوحدات هما TD (العزم المدور) و RD (معدل الاختراق) و بواسطة رسمهما مع بعض ، يتم تحديد قيم الثابتين a1 و a2 و اللذان كلاهما يستخدمان لحساب الحدّين عديمي الوحدات الآخرين و هما ED (كفاءة الحافرة) و FD (مدى استهلاك الحافرة) كمؤشرين لتقييم استهلاكية الحافرة أكثر من الطرق التقليدية الأخرى. هذه الطريقة طُبقّت لثلاث آبار : زبير رقم 166 و زبير رقم 162 و زبير رقم 174 في حقل الزبير جنوبي العراق. النتائج المُستحصلة يمكن أن تكون مفيدة لاكتشاف استهلاكية الحافرة و وفقاً لذلك فأن قرار سحب و استعمال حافرات جديدة يمكن تحديدهُ بسهولة و بذلك فأن عمليات الحفر يمكن أن تتم بفعالية و بأقل تكاليف و جهد.


Article
Effect of Sodium Modifier on the Microstructure and Wear Rate of Al-14 Wt%Si Alloy
تأثیر التعدیل بالصودیوم على البنیة المجھریة ومعدل البلى لسبیكة الالمنیوم- 14 % سلیكون

Authors: Haitham Rzouqi Saleh --- Mahdi Muter Hanoon --- Adnan Ibrahim Mohammed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2010 Volume: 28 Issue: 22 Pages: 6615-6622
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, a demonstration of the effect of Na addition to themicrostructure and wear rate of hypereutectic Al-14 wt% Si alloy was carried out. It isfound that the addition of Na has an important effect on shifting the eutecticcomposition of Al-Si alloys from approximately 12 wt% to 14 wt% Si; shifting theunmodified alloy from hypereutectic to eutectic alloys for the modified alloys. Themodified alloys have a eutectic composition with fine needle at lower Na content(0.05 wt%). Increasing the percentage of Na to 0.12 wt% resulted in producing alamellar Si structure compared with acicular structure for unmodified alloy. The wearrate of modified alloys is lower than the hypereutectic alloy. Wear rates observedwere in the range of 10-9 to 10-11 which is fully identified in the mild wear rate regime.

في ھذه الدراسة تم توضیح تأثیر إضافة الصودیوم على البنیة المجھریة ومعدل البلى لسبیكة الألمنیوم-سلیكون فوق الایوتكتیكیة ذات نسبة سلیكون 14 %. لقد وجد بان إضافة الصودیوم لھ تأثیر كبیر بإزاحة نقطةالایوتكتیك لسبائك الألمنیوم-سلیكون من ما یقارب 12 % إلى 14 % سلیكون بعد التعدیل لذلك السبیكة الفوقایوتكتیكیة قبل التعدیل تم تحولھا إلى سبائك ایوتكتكیة بعد التعدیل. امتازت ألسبائك المعدلة بتركیب ایوتكتیكىذات تركیب أبرى ناعم عند محتوى الصودیوم 0.05 %. أدت زیادة نسبة الصودیوم المضافة إلى 0.12 % إلىالحصول على تركیب طبقي للسلیكون مقارنة مع شكل السلیكون العدسى للسبیكة الغیر معدلة. معدل البلى01 سم 3/سم - 10 إلى 11 - للسبائك المعدلة اقل من السبیكة قبل التعدیل. وان معدل البلى للسبائك بقع ضمن المدى 9والذي یقع بصورة كاملة ضمن مدى معدل البلى الواطئ

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