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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
The Surface Hardness Measurement of Stone and Improved Die Stone After the Addition of a Mixture of Chemical Additives with Different Proportion

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Abstract

Background: Incorporation of chemical additives has long been a technique used to improve properties of the gypsum products. The purpose of this work was to study the effects of adding a combination of gum Arabic and calcium hydroxide to a type III dental stone and type IV improved die stone with different proportion. The effect on water/powder ratio, and surface hardness was determined.Material and method: Both material stone and die stone were blended with two proportion of additives so that each material was mixed twice but with different proportion of gum Arabic (0.1% and 0.2%) and calcium hydroxide (0.5 % and 0.3%). Data for hardness were subjected to two-way analysis of variance.Results: The results revealed that the chemical additives were reduced the water requirements of gypsum products so that the reduction of water lead to increase the density of mixture that sets harder. For type III dental stone the additives significantly improved the surface hardness, while for type IV improved die stone the surface hardness was not enhanced except it was designed to be mixed at low water/powder ratio, and in some instances a reduction in hardness was observed, especially at the most reduced water / powder ratio (0.18)


Article
CONTROLLING THE WORKING AREA IN FLEXIBLE SHEET FORMING DIES

Author: Wissam K. Hamdan
Journal: Iraqi journal of mechanical and material engineering المجلة العراقية للهندسة الميكانيكية وهندسة المواد ISSN: 20761819 Year: 2009 Volume: 9 Issue: 3 Pages: 360-368
Publisher: Babylon University جامعة بابل

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Abstract

Design and fabrication of a die, in the case of sheet metal forming, is an experimentally iterative process. So, the hard sheet metal forming dies are generally dispensed with flexible dies. This paper presents a simple approach to control the motion of the die pins and estimation of blank working area. The proposed method is directed to control any free form shapes such as Bezier surfaces. The results of the study are simulated in suitable programming code (MATLAB and IronCAD) to show the effect of proposed method.

من الطرق التي تحتاج إلى عمليات تكرار متعددة هي عملية تصميم أو بناء قوالب التشكيل وخصوصا قوالب تشكيل الصفائح المعدنية. ولهذا فان القوالب الصلدة تم استبدالها بقوالب مرنة لتقليل الكلف. يهدف البحث إلى عرض طريقة مبسطة للسيطرة على حركة المسامير المكونة لهذه القوالب وتخمين المساحة العاملة للغفل. تختص الدراسة بنمذجة الأسطح الحرة مثل سطح بيزير. تمت محاكاة نتائج الطريقة المقترحة باستعمال بعض البرامج الحاسوبية المعروفة مثل MATLAB و IronCAD لعرض نتائج البحث وبيان أهمية الطريقة المعتمدة.


Article
Re-design punch and die of the laboratory pharmaceutical tablet press machine
اعادة تصميم الخرامة والقالب لماكنة مختبرية صيدلانية تستخدم لاغراض كبس الحبوب

Author: Ramiz Saeed Matty Samarjy رامز سعيد سمرجي
Journal: AL Rafdain Engineering Journal مجلة هندسة الرافدين ISSN: 18130526 Year: 2010 Volume: 18 Issue: 5 Pages: 123-136
Publisher: Mosul University جامعة الموصل

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Abstract

AbstractThis research represents an attempt to solve a problem introduced by Ninevah drug factory to increase the out put of one of its laboratory machine located in research sector . First of all, thinking was for selection a suitable material of punches and die compatible with the surrounding environments of different drug powders as they represents corrosive agents to the metal that in touch .Beside that this material primarly must be capable of being machined to manufacture the required design, Also it is capable to be heat treated after manufacturing . Second ,we should redesign the punch and die with the same surrounding spans limitation but with increasing the number of used punches and redistributing them in a suitable manner in its restricted die, and manufacturing punches with a different sizes (7, 9, 7.9,10.3,12.53 )mm in diameter as the factory demand taking into account the concave and convex of pair of punches to create the mirror shape of tablet after pressing is completed . All that will be done must give the standardized weight , size and optimum compressibility according to the certificate of the quality control unit. Keywords: punch , die , tablet , powder.

الخلاصةهذا البحث يمثل محاولة من اجل تطوير ماكنة مختبرية تستخدم لاغراض كبس الحبوب الصيدلانية او الدوائية عائدة للشركة العامة للصناعات الدوائية في نينوى / قسم البحث والتطوير .بادى الامر كان التفكير باختيار المعدن المناسب لكل من الخرامة والقالب والذي يتلائم مع البيئة المحيطة من انواع المساحيق الدوائية المختلفة باعتبارها عوامل تساعد على التاكل للمعدن الذي سوف يكون باتصال اواحتكاك معها، اضافة الى ان المعدن المختار يمكن تشغيلة بسهولة من اجل تحقيق التصميم المطلوب وكذلك يمكن اجراء المعاملات الحرارية اللازمة له بعد التصنيع. المحور الثاني ينصب على اعادة تصميم الخرامة والقالب ضمن الابعاد المحددة للماكنة نفسها ولكن بزيادة عدد الخرامات واعادة توزيعها بالشكل المناسب ضمن شكل القالب الاصلي للماكنة، ومن ثم تصنيع خرامات بابعاد قطرية (7،9،7.9،10.3 و12.53 ملم) حسب متطلبات الشركة اخذين بنظر الاعتبار التحدب والتقعر لكلا زوجي الخرامة العلوي والسفلي لاعطاء هذا التشكيل للحبة بعد اكمال كبسها وفي النهاية فان المنتج يجب ان يحقق المواصفة المطلوبة من حيث الوزن والانضغاطية المناسبة والذي يمثل اهم جزء من محاور هذة الدراسةالكلمات الدالة ( خرامة ، قالب ، حبة ، مسحوق)

Keywords

Keywords: punch --- die --- tablet --- powder.


Article
Evaluation of Some Physical Properties of Die Stone Made From Local Raw Gypsum Material

Authors: Lamia T Rejab --- Salwan F Al-Hamdani --- Mohammed Y
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2012 Volume: 12 Issue: 20 Pages: 309-315
Publisher: Mosul University جامعة الموصل

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Abstract

Aim: The aim of this study was to prepare die stone material by dehydration of the local natural raw gypsum in boiling with 30% calcium chloride solution , and then evaluated some physical properties of this prepared die stone. Materials and methods : The values of some physical properties of the pre-pared die stone in boiling with 30% calcium chloride solution which are water/powder ratio, setting time, and compressive strength were compared with that of three types of gypsum products commer-cial die stone, Elite type III dental stone and Iraqi plaster. The data were collected , mean and standard deviation were determined. Statistically, (ANOVA) and Dunnett Pairwise Multiple Comparison test were carried out to determine the significant differences at p≤ 0.05 Results: Results showed that there were no significant differences between the locally prepared die stone and the commercial one at p≤ 0.05 in water/powder ratio and setting time values, but it was significant difference in compressive strength. But there are a significant difference between the physical properties of the locally prepared die stone and Elite type III dental stone and Iraqi plaster. Conclusions: The results showed the physical properties of the locally prepared die stone approach the physical properties of the commercial product according to the recommendation of ADA for gypsum products.


Article
Compressive strength and surface roughness of die stone cast after repeated disinfection with sodium hypochlorite solution

Authors: Sunus Al-Azzawi --- Amer M Khamas عامر خماس --- Jwad Michael جواد مايكل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2010 Volume: 22 Issue: 3 Pages: 27-33
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The transmission of oral pathogen to impression and subsequently on to gypsum cast has beendemonstrated, and dental stone cast have to be disinfected to prevent the transmission of infectous disease, thisinfection process may affect some physical or mechanical properties of the cast. The aim of the study was toevaluate the compressive strength and surface roughness of type IV dental stone cast after repeated immertion inand sprying using (0.5%) sodium hypochlorite disinfectant solution.Materials and methods: A total of (42test blocks) were prepared and divided to (3) three groups (14each) (controlspray and immersion) for the surface roughness test. These were subdivided into (2) groups (7) each to be testedafter (24 and 48 hours) the same distribution of the test block were followed for the compressive strength test. Foreach test 1/3 of the test black immersed in the disinfectant solution for 30 minutes then allowed 24 hours for be eachdrying this was repeated 5times before being tested, 1/3 of the specimens were sprayed with the disinfectant 5 timesin an interval of 24 hours for bench drying the last 1/3 blokes were the control.Results: Immersing or spraying with hypochlorite solution significantly decreased the compressive strength after 24hours and increased after 48 hours. As for the surface roughness the results showed that both spraying and immersionsignificantly increased the value of the roughness, with immersion as a higher value. Spraying with (0.5%) sodiumhypochlorite solution provide smoother dental stone casts surfaces and adequate compressive strength whenallowed for (48hours) compared to immersion group bench drying.Conclusion: Dental stone casts disinfected by immersion method showed a higher surface roughness than thosedisinfected by spraying.


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
Histopathology of grapevine inoculated with Lasiodiplodia theobromae
التغيرات المرضية النسيجية لنبات العنب الملقحة بالفطر Lasiodiplodia theobromae

Author: Abdullah H. Al-Saadoon عبد الله حمود عبدالله
Journal: Basrah Journal of Agricultural Sciences مجلة البصرة للعلوم الزراعية ISSN: 18175868 Year: 2012 Volume: 25 Issue: 1 Pages: 1-12
Publisher: Basrah University جامعة البصرة

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Abstract

Histopathological changes of 2-years old grapevine cv. Abbassi inoculated with Lasiodiplodia theobromae (syn. Botryodiplodia theobromae) were studied. Samples were taken at 7 and 25 days after artificial inoculation. At 7 days, cross and longitudinal sections revealed the presence of disorganized cells, degenerated areas and vascular bundles. The intra and intercellular invasion of the inoculated tissues by the fungus were evident with dark brown color. At 25 days, the fungus caused necrosis in xylem parenchyma and xylem vessels, the hyphae colonized the tissues. Dark deposits appeared in vessels and other tissues as well as abundant production of tyloses. L. theobromae has also been found to produce pycnidia on the shoots and petioles of grapevine which yielded 2-celled dark pycindiospores. After more than 4-weeks, the inoculated grapevine seedlings look flaccid, brown in color and wilting symptoms began to appear and finally the seedlings were dead.

درست التغيرات المرضية النسيجية لنبات العنب (صنف عباسي), بعمر سنتين والملقح بالفطر Lasiodiplodia theobromae. اخذت العينات بعد سبعة و25 يوم من الإصابة الاصطناعية بعد سبعة أيام من الإصابة, أظهرت المقاطع الطولية والعرضية عدم انتظام الخلايا وتحلل الحزم الوعائية. واثبت غزو الفطر داخل خلوي وبين خلوي للانسجة المصابة مع تلون الأنسجة باللون البني الداكن. في اليوم 25 من الإصابة, سبب الفطر تنخر برنكيما واوعية الخشب واستعمار الخيوط الفطرية للانسجة. وشوهدت ترسبات داكنة في الأوعية والأنسجة الاخرى مع كثرة تكوين التايلوزات. ولوحظت بكنيديا الفطر L. theobromae على الأغصان وحوامل الاوراق, وقد كونت ابواغا بكنيدية داكنة ثنائية الخلايا. بعد اكثر من أربعة اسابيع, بدت نباتات العنب (صنف عباسي) مترهلة,بنية اللون, وظهرت عليها اعراض الذبول, وفي النهاية موت النباتات.


Article
Comparison of Applied Pressure Effect on ImprovingDensity, Hardness, and Microstructure by Both SqueezeCasting Process and Pressure Die Casting Process for 380-Al Alloy

Author: Dr. Najeeb S. Abtan Dr. Kadhim H. Ghlaim
Journal: Iraqi journal of mechanical and material engineering المجلة العراقية للهندسة الميكانيكية وهندسة المواد ISSN: 20761819 Year: 2012 Volume: 12 Issue: 2 Pages: 334-344
Publisher: Babylon University جامعة بابل

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Abstract

The present study includes the effect of applied pressure on elimination theporosities that formed during both squeeze casting process and pressure die casting.For pressure die casting the pressure was applied on the full liquid molten alloy (750oC) where the pressure was applied on molten alloy at (650oC) i.e. the molten was fifty liquid fifty solid (mushy zone). The tests and measurements of density, hardness, and microstructure show theimprovement in density and hardness for the samples of both techniques but theincreasing in hardness and density values in squeeze casting were higher than thevalues of pressure die casting samples also the test of microstructure shows thedecreasing in (DAS) for the squeeze sample more than the (DAS) of pressure castingsamples.The above improvement in microstructure, hardness, density belongs to the behaviorof applied pressure in both cases which means that the mushy zone of molten alloyrepresents the optimum region to improve the mechanical properties by appliedpressure


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.

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