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Article
The Effect of Area Reduction of Forward Die on the Combined Forward- Backward Extrusion Process
تأثير التخفيض في مساحة القطع للقوالب الأمامية (Forward) في عملية البثق المركب (Forward- Backward

Authors: Ali Hassan Saleh علي حسين صالح --- Muhsin Jabur Jweeg محسن جبر جويج --- Jamal Hussien Muhamed جمال حسين محمد
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2009 Volume: 12 Issue: 2 Pages: 108-121
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

The effect of reduction area for flat and conical dies in forward-backward extrusion process was investigated experimentally using flat punches with three reduction areas (0.305,0.444,0.605), 0.444 with cone angles (60o,90o,120o) and polygonal punches (hexagonal and square).Three reduction areas of dies (0.395, 0.555, 0.691) are used. The results show that the extrusion load is effected with reduction area of flat dies more than conical dies when using cone and flat punches while the reduction area of conical dies affected with square punch more than hexagonal punch and this result was inversed with flat dies. The relative extrusion pressure P/Y ̅ increases when the reduction area of conical and flat dies increases too for all punches, but this result contrasts with the square punch at conical dies.The less value of max. stress was found with cone punch of prism angle 120o among cone punches for conical dies except the die of reduction area (0.555) and the cone punch of 90o prism angle gave less max. stress with all flat dies. Flat punch of reduction area (0.444) among the flat punches gave less value of max. stress with all conical dies and flat die of reduction area (0.691).

تم دراسة تاثير التخفيض في مساحة المقطع للقوالب المسطحة والمخروطية في عملية البثق المركب عمليا باستخدام مكابس مسطحة بنسب تخفيض في مساحة المقطع (0.305,0.444,0.605 (ومكابس مخروطية بثلاث زوايا (60o,90o,120o) ذات نسبة تخفيض ثابتة (0.444) ومكابس مضلعة الشكل (سداسي ، مربع) ذات نسبة تخفيض في مساحة المقطع متساوية (0.444 (.تم استخدام ثلاثة نسب تخفيض في مساحة المقطع للقوالب هى(0.395, 0.555, 0.691) .النتائج اظهرت ان حمل البثق يتأثر بنسبة تخفيض المساحة للقوالب المسطحة اكثر من القوالب المخروطية عند استعمال المكابس المخروطية والمسطحة بينما يتأثر حمل البثق بنسبة تخفيض القوالب المخروطية مع المكبس المربع الشكل اكثر من المكبس السداسي الشكل ، بينما تنعكس هذه النتيجة مع القوالب المسطحة . ان ضغط البثق النسبي (P/Y ̅) يزداد عندما تزداد نسبة التخفيض في مساحة المقطع للقوالب المخروطية الشكل والمسطحة مع كافة المكابس الا ان هذه النتيجة مختلفة في المكبس المربع مع القوالب المخروطية . ان ضغط البثق النسبي يتغير مع نسبة تخفيض المساحة للقوالب المسطحة مع المكابس المضلعة.

Keywords

Extrusion --- Die


Article
Evaluation of Rotation, Tipping and Extrusion During Canine Retraction by Sliding Mechanics Using Different Arch Wires

Authors: Mustafa M Hamed --- Hind T Jarjees --- Khawla M Awni
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 3 Pages: S93-S102
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate the amount of rotation, tipping and extrusion using different wires and to Estimate the difference in the amount of tipping, rotation and extrusion between Stainless steel and Teflon ligature in different wires. Materials and Methods: The standardizing criteria were all Typodont teeth situated in well–aligned, covered and immobilized by the acrylic bite except canine; The available space for canine sliding was (14 mm) measured by digital vernia. Elastic chain exerting 180 gm of force on canine measured carefully by tension gauge. In both vertical and horizontal direction a photographs that were taken for Typodont using digital camera. The angle between bite plane extension bar and Canine extension bar were (90o) measured by protractor directly on the photograph. Preformed band with its attachments, ready made stainless steel, composite coated and TMA arch wires all were (0.018×0.025) with the use of stainless steel and Teflon ligature, Standard titanium spring 11 mm length, Typodont components, within six types of connection the two types of ligation material had been applied to the three different wires then the 1st premolar space tend to be closed by distal canine displacement then the resultant rotation, tipping and extrusion were measured. Statistical Descriptive analysis: One–way and, Two–ways Analysis of Variance were done to detect the variability between methods and which is the best. Results: Three important results showed in the study: First, canine sliding over the composite coated arch wire with the use of stainless steel ligature gave rise to significant decrease in rotation, tipping and extrusion when compared with other methods. Second, stainless steel ligature when compared with Teflon ligature of the same corresponding method gave rise to a significant decrease in the degree of rotation tipping and extrusion. Third, Composite coated arch wires showed lowest degree of rotation then followed by TMA arch wires ordinarily this is due to their rough surface. The largest rotation seen in the stainless steel arch wire this is due to its smooth surface texture, and the same thing for the tipping of the composite coated wires that gave rise to the lowest degree of tipping followed by the stainless steel wires, these result possibly due to their stiffness then higher tipping seen at TMA wires ordinarily a result of their flexibility this sequence were the same for both types of ligations. Conclusions: Best method of space closure is the use of either composite coated arch wire or stainless steel arch wire with stainless steel ligature that give us highest resistance to tipping, lowest extrusion and relatively little rotation when compared with other methods.

Keywords

Rotation --- tipping --- extrusion


Article
Theoretical and Experimental Investigation of the Effect of the Punch Angle on the Backward Extrusion Process

Author: Ethar Mohammed Mahdi
Journal: Journal of University of Babylon مجلة جامعة بابل ISSN: 19920652 23128135 Year: 2012 Volume: 20 Issue: 4 Pages: 1136-1149
Publisher: Babylon University جامعة بابل

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Abstract

The variation of punch angle on the flow metal for the backward extrusion is investigated theoretically and experimentally. Punches with different semi-cone angles varying from 30, 60, 70, 90 ° have been used to study its effect on the pressure required to extrude indirectly for lead. The findings of this experimental study show agreement in trends with the theoretical predictions. From this study it can be concluded that by a little change in the backward reduction in cross- sectional area different types or modes of extrusion process may be obtained and the streamline profile of the punch surface have an important effect in homogeneity of the material flow in the backward direction i.e. that the working pressure decreased when increasing the punch angles, the fact that the redundant strains will be decreased and there will be less restriction on the material flow also due to the complex deformation situation during the backward extrusion and availability of more than one type of velocity field through the process duration, finite element analysis via ANSYS software may be the superior for application.

تم دراسة تغيير زاوية المخرم على جريان المعدن خلال عملية البثق العكسي حيث تمت الدراسة نظريا وعمليا . وقد استخدمت زوايا مختلفة للمخرم هي 30 و 60 و 70 و 90 درجة لدراسة تأثيرها على الضغط اللازم للبثقالغير مباشر لمادة الرصاص . تشير نتائج هذه الدراسة إلى تطابق بين النتائج التجريبية مع التنبؤات النظرية . يمكن أن نستنتج من هذه الدراسة بان تغيير قليل في مساحة انخفاض مقطع البثق العكسي يؤدي الى أنواع مختلفة من اطوار البثق وان انسيابية شكل المخرم له تاثير كبير على جريان المعدن بما معناه ان القوة تقل عند زيادة زاوية المخرم. والحقيقة أنه سيتم خفض الانفعالات الزائدة عن الحاجة وسيكون هناك قيود أقل على تدفق المعدن بسبب الحالة المعقدة للتشوه التي تحصل في عملية البثق العكسي. ان طريقة العناصر المحددة باستخدام برنامج ANSYS تعتبر من افضل الطرق لتحليل عملية البثق.


Article
The Effect of Insertion Rate on The Adaptability of Gutta-Percha and The Apical Extrusion of Thermoplasticized Gutta Percha Obturation Techniques

Author: Samer Aun Thyab Al-Shimari سامر عون ذياب
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2017 Volume: 29 Issue: 4 Pages: 33-36
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: In the Thermafil as a root canal obturation, system little is known about the effect that varying rates of insertion have on the adaptability of thermoplasticized GP and the amount of apical extrusion.Materials and methods: thirty simulated root canals were obturated with thermafil obturators and Apexit Plus sealer at three different insertion rates. The obturated canals were sectioned at three different levels, the sealer average film thickness for each section was calculated and the amount of apical extrusion for each canal was conducted.Results: the higher adaptability was seen with the faster insertion rate while the slower insertion rate showed fewer tendencies to cause apical extrusion.Conclusions: the intermediate insertion rate had the best results between the other two rates for both adaptability and apical extrusion


Article
INVESTIGATION OF SOME PARAMETERS INFLUENCING OF THREE DIMENSIONAL TUBE EXTRUSION PROCESS OF ELLIPSE SECTION THROUGH STREAMLINE DIE
دراسة بعض المتغيرات المؤثرة على عملية بثق ثلاثي الأبعاد لأنبوب بيضوي المقطع خلال قالب انسيابي

Author: Saad Theyyab Faris سعد ذياب فارس
Journal: DIYALA JOURNAL OF ENGINEERING SCIENCES مجلة ديالى للعلوم الهندسية ISSN: 19998716/26166909 Year: 2010 Volume: 3 Issue: 1 Pages: 1-15
Publisher: Diyala University جامعة ديالى

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Abstract

In cold lubricated tube extrusion of ellipse section the material properties and surface quality of the extruded products are influenced by the die profile so in the present analysis the axial velocity component on the intermediate cross-section in the plastically deforming region is expressed as a general function of the coordinates . This allows the description of complete three dimensional distortion of flow rendering more realistic flow patterns .From the derived kinematically admissible velocity field , corresponding upper-pound theory the extrusion pressure is then obtained by optimizing the pressure with respect to the given parameters ..The effective strains are computed in order to study the work hardening pattern of the extruded products ,also (F.E M) by ANSYS (11) software was used in building, loading and solving the extrusion process, the model generation depends on the Billet (AL 2024 fully annealed) have been carried as the working material. In the computation the product shape was ellipse with the effects of area reduction, die length product shape complexity and frictional condition on the extrusion pressure, the metal flow and distribution of the final effective strain have been studied extensively. The simulation using (ANSYS 11 PROGRAM), theoretical predictions both in extrusion load and metal flow are in good agreement with the experimental results.

في عملية البثق على البارد والتزييت لأنبوب بيضوي المقطع ان الخواص والأسطح الكافية للمنتج تتأثر بالشكل الهندسي للقالب لذا في هذه الدراسة تم تحليل مركبات السرعة في منطقة التشوية اللدن وسط المقطع وعبر عنها كدالة عامة لكي يسمح بوصف الأبعاد الثلاثية لتوزيع الانسياب بمرونة أكثر. من خلال الاشتقاق لحقل السرعة الحركية وفق نظرية الحد الأعلى إن ضغط البثق تم الحصول عليه من خلال عملية التماثل وفق المتغيرات المعطاة للمادة والانفعالات المؤثرة تم حسابها من اجل دراسة جزء التصليد الانفعالي لمنتجات البثق وكذلك بطريقة العناصر المحددة (F.E.M) من خلال برنامج Ansys11)) لبناء نموذج القالب والتحميل والحل العددي والنموذج المتولد يعتمد على خامة الألمنيوم (2024) تام اللدونة. في حسابات المنتج بشكل بيضوي المقطع وبتأثير معامل الاحتكاك , التخصر بالمساحة وطول القالب على ضغط البثق إن انسياب المادة وتوزيع الانفعال المؤثر درست بشكل تفصيلي وان المحاكاة باستخدام برنامج ((Ansys11 والإجراءات النظرية لكل من حمل البثق وانسياب المادة كانت متوافقة بشكل جيد مع نتائج مختبرية.


Article
Plane Flow Analysis for a Profile Extrusion Die Using Digital Image processing Technique
تحليل الأنسياب المستوي في قالب بثق بأستخدام تقنية المعالجة الصورية الرقمية

Authors: Salah K. Jawad --- Ali Abbar Khleif --- Mohanad Q. Abbood
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2012 Volume: 30 Issue: 9 Pages: 1562-1581
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This paper investigates the applicability of the proposed digital imagecorrelation (DIC) system instead of traditional method by microscope tomeasure the strains in forward extrusion process, which conducted forrectangular section with plane strain condition by using taper die at angle(2 = 90 ̊) and the proportion of reduction in area is (42.85 %).Commercial pure lead (99.99% Pb) was chosen as a typical pattern tomeasure the strain and strain rate for the forward extrusion process by avisio-plasticity technique and the proposed digital image correlationsystem. The obtained results indicate that the proposed digital imagecorrelation (DIC) system is an accurate and reliable for measuring thestrains using inexpensive equipments

يتناول هذا البحث قابلية تطبيق نظام مطابقة الصور الرقمية المقترح بدلاً من الطريقةالتقليدية بأستخدام المجهر لقياس الأنفعال خلال عملية البثق الأمامي، حيث تم إجراء العملية(2 = لمقاطع مربعة تحت ظروف الأنفعال المستوي بأستخدام قالب مخروطي بزاوية ( 90(% وبنسبة تخصر للمساحة مقدارها ( ٤٢.٨٥ %). تم أختيار الرصاص النقي التجاري ( ٩٩.٩٩كنموذج لأجراء عملية البثق الأمامي ومن ثم قياس الأنفعال ومعدل الأنفعال بأستخدام كل منتقنية اللدونة المرئية ونظام مطابقة الصور الرقمية المقترح في هذا البحث. لقد بينت النتائجالمستحصلة دقة ومعولية النظام المقترح لمطابقة الصور الرقمية في قياس الأنفعال بأستخداممعدات غير مكلفة.


Article
The influence of instrument application frequency on the apical extrusion of debris using rotary ProTaper, hand ProTaper and hybrid technique (An in vitro study)

Authors: Majida K. Al-Hashimi ماجدة الهاشمي --- Zaid K. Al-Doory زيد الدوري
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 4 Pages: 34-39
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Various kinds of hand-held or rotary instruments and techniques are used for mechanical preparationof the canal during root canal treatments. These instruments and techniques may push debris out of the canalswhich may induce inflammation within the periapical area; therefore, instrumentation technique that causes lessextrusion of debris is more desirable. The aim of this study was to compare the effect of instrument applicationfrequency on the amount of apically extruded debris.Materials and Methods: One hundred and twenty extracted human teeth were used in this study; all teeth wereshortened to a length of 15 mm. Each experimented root was mounted on a centrifuge tube that forced through aprecut hole in a rubber stopper of a glass vial. The roots were divided randomly into 3 groups, each group contained40 roots. Group R: prepared by rotary ProTaper, Group H: prepared by hand ProTaper, Group S: prepared by Hybridtechnique. Each group was further subdivided in to five subgroups (A, B, C, D, and E). Debris extruded from apicalforamen was collected in a centrifuge tube containing 0.5 milliliter of distilled water. Each empty centrifuge tube wasweighed before preparation by 0.0001g. sensitive weighing machine. Then at the end of canal preparation, thesecentrifuge tubes were completely dried using an incubator at 68 C° for two days and weighed again. The differencebetween the weights of tubes in two stages represented the weight of debris extruded from apical foramen duringinstrumentation.Results: No significant difference recorded for the mean weight of apically extruded debris regarding the instrumentapplication frequency within the same instrumentation technique; but there was a high significant difference for thesubgroups (A, B, C, and D) and a significant difference for subgroup E, regarding the effect of instrumentationtechniques on amount of apical extrusion of debris among tested groups.Conclusion: The hand ProTaper extruded smaller amounts of apical debris than the rotary ProTaper and largeramounts than Hybrid technique


Article
Effect of Die Angle on Stress Distribution in Extrusion Process of Aluminum Rod

Author: Rafid Jabbar Mohammed
Journal: Basrah Journal for Engineering Science مجلة البصرة للعلوم الهندسية ISSN: Print: 18146120; Online: 23118385 Year: 2014 Volume: 14 Issue: 2 Pages: 43-50
Publisher: Basrah University جامعة البصرة

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Abstract

Type of metal flow and stress distribution in metal extrusion process is a highly complex for the complicated die design. In this work a finite element simulation of Al-1100 rod extrusion was successfully achieved using the commercial finite element code Deform-3D.The results show that the finite element model was successfully simulate the stress distribution in the direct rod extrusion of Al-1100.Besides that the optimum die angle reduces the magnitude of normal, shear, and effective stresses. We can conclude from this studythat maximum stresses occour when the rod is with contact with the die at exit stage.


Article
The legalization of extrusion of employee or equivalents (a comparative study)
إباحة قذف الموظف أو من في حكمه " دراسة مقارنة "

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Abstract

AbstractGiven the seriousness and importance of the work performed by the employee or the equivalents in the community, it has been subjected comparative legislation that works for multiple images of control, including the control of the People, which permits citizens to control the acts of employees or the like and detect defects and shortcomings which riddled and deviations which commit occasion they do their business and that was affecting their honor or considered by the recognition of the right to challenge the work of the employee or the like, or the so-called French jurisprudence (le exception veritatis) . Since the right of appeal in the work of the employee or the like may involve the implications of intervention under the description of the crimes of libel and insult, they admit comparative legislation to legalize the use of the right to appeal if there is objective conditions to be observed by granting the accused the right to validate the facts of defamation through the payment by the fact that lead to the legalization of libel actions against the employee or the equivalents. On the basis of the above, specialized research study to ensure the defence of truth and its impact on the legalization of throwing the employee and the like according to a method analytical comparison, was divided research into two sections, taking the first section of what the right to challenge in the work of the employee or the like, while specialize second topic statement guarantee of the defence of truth, and finally conclude Find a conclusion in which the statement was the most important findings, and some of the proposals that reflect use them in the future.

ملخص البحثنظرا لخطورة وأهمية الأعمال التي يقوم بها الموظف أو من في حكمه في المجتمع ، فقد أخضع التشريع المقارن تلك الأعمال لصور متعددة من الرقابة ومنها الرقابة الشعبية ، حيث أباح للمواطنين الرقابة على أعمال الموظفين أو من في حكمهم وكشف العيوب والنواقص التي تعتريها و الإنحرافات التي يرتكبوها بمناسبة مزاولتهم أعمالهم وإن كانت تمس شرفهم أو إعتبارهم من خلال الإعتراف بحق الطعن في أعمال الموظف أو أعضاء المجالس النيابية أو المكلفين بخدمة عامة ، أو ما يطلق عليه الفقه الفرنسي (الدفع بالحقيقة) .ولما كان حق الطعن في أعمال الموظف أو من في حكمه قد ينطوي على مضامين تدخل تحت وصف جرائم القذف والسب ، فقد أعترف التشريع المقارن بإباحة إستعمال حق الطعن إذا توافرت الشروط الموضوعية الواجب مراعاتها من خلال منح المتهم حق إثبات صحة وقائع القذف من خلال الدفع بالحقيقة مما يؤدي إلى إباحة أفعال القذف بحق الموظف أو من في حكمه .وتأسيسا لما تقدم ، إختص البحث بدراسة ضمان الدفع بالحقيقة وأثره في إباحة قذف الموظف ومن في حكمه وفق منهج تحليلي مقارن ، وتم تقسيم البحث الى مبحثين ، تناول المبحث الأول ماهية حق الطعن في أعمال الموظف أو من في حكمه ، في حين أختص المبحث الثاني ببيان ضمان الدفع بالحقيقة ، وأخيرا أختتم البحث بخاتمة تم من خلالها بيان أهم النتائج التي توصل اليها ، وبعض المقترحات التي نتأمل الاستفادة منها مستقبلا .


Article
Comparative Study of The Amount of Apically Extrusion Of Debris During Root Canal Preparation Using Wave One™, Trushape 3D™, Hyflex™ CM and One Shape™ Instrumentation Systems (An In Vitro Study)

Authors: Ali W. Hadi --- Mohammed R. Hameed محمد رشيد حميد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2017 Volume: 29 Issue: 1 Pages: 1-8
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Many types of instruments and techniques are used in the instrumentation of the root canal system. These instruments and techniques may extrude debris beyond the apical foramen and may cause post-instrumentation complications. The aim of this study was to evaluate the amount of apically extruded debris resulted by using 4 types of nickel-titanium instruments (WaveOne, TRUShape 3D conforming files, Hyflex CM, and One Shape files) during endodontic instrumentation.Materials and methods: Forty freshly extracted human mandibular second premolar with straight canals and a single apex were collected for this study. All teeth were cut to similar lengths. Pre-weighted glass vials were used as collecting containers. Samples were randomly divided into four groups with 10 samples in each group: Group A instrumentation by WaveOne reciprocating file, Group B instrumentation by TRUShape 3D rotating files, Group C instrumentation by Hyflex CM rotating files and Group D instrumentation by One Shape rotating file. A total volume of 7 ml of sodium hypochlorite was used for irrigation in each sample. Apical patency confirmed and maintained by a size #15 K-File. All canals were instrumented up to a size #25. After completion of endodontic instrumentation, vials were then stored in an incubator for 5 days at 68o C for dryness. Then vials are weighted again, and the pre-weight subtracted from the post-weight, the weight difference resembled the amount of apically extruded debris from the apical foramen during root canal instrumentation. Data obtained were statistically analysed by using ANOVA and LSD tests.Results: The results showed that the Hyflex CM Group (C) has statistical significant lowest apically extruded debris as compared to other groups of this study (P ≤0.05), while the TRUShape Group (B) has statistical significant lowest apically extruded debris as compared to One Shape Group (D) and WaveOne Group (A), while the WaveOne Group (A) showed the highest value of apically extruded debris (p ≤0.01). The result showed that all groups resulted in apical extrusion of debris.Significance: Although all systems caused apical extrusion of debris and irrigant, continuous rotary instrumentation was associated with less extrusion as compared with the use of reciprocating file system

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