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Article
Evaluation of compressive strength for refractory casts made from different investment materials

Author: Ahmed A Al–Ali
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2007 Volume: 7 Issue: 14 Pages: 166-172
Publisher: Mosul University جامعة الموصل

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Aims: To compare the compressive strength of refractory casts made from investments for cobalt–chromium and investment for titanium and to study the effect of mixing fluid on compressive strength.Materials and Methods: Three types of investments were used, one for titanium and two for cobalt–chromium, each one is mixed with three types of mixing fluids; tap water, distilled water and special liquid,to produce refractory casts. Compressive strength test was carried out using compression testing machine.Results: Showed significant differences in compressive strength between the types of investments, withtitanium investment mixed with special liquid showed the highest value. There were significant differencesbetween subgroups of the same type by changing mixing fluid type. Conclusions: Refractory casts madefrom titanium investment showed significantly higher compressive strength than refractory casts madefrom Co–Cr investments, and there was a difference between the two special liquids used, and tap water inwhich it produced casts with higher compressive strength than distilled water in two out of the threeinvestment materials tested.


Article
Performance Evaluation of the Investment Projects during the Implementation Phase (Najaf province as a case study)
تقييم الاداء المشاريع الاستثمارية خلال مرحلة التنفيذ (محافظة النجف حالة دراسية)

Authors: Dhefaf Madlool Aljanabei ضفاف مدلول الجنابي --- Kadhim Raheem Erzaij كاظم رحيم رزيج
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2016 Volume: 22 Issue: 8 Pages: 54-74
Publisher: Baghdad University جامعة بغداد

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The construction project is a very complicated work by its nature and requires specialized knowledge to lead it to success. The construction project is complicated socially, technically and economically in its planning, management and implementation aspects due to the fact that it has many variables and multiple stakeholders in addition to being affected by the surrounding environment. Successful projects depend on three fundamental points which are cost-time, performance and specifications. The project stakeholder's objective to achieve best specifications and the cost-time frame stipulated in the contract.The question is, was the optimum implementation accomplished? The provision for the success of the project is how are the daily activities managed by the three stakeholders of the project (contractor, owner, and consultant) and their technical and practical capability to attain the balance of the project fundamental points (cost, time and quality) taking into account the project objectives that were set by the owner. Despite the way, logical framework management and project’s major steps there is a group of elements which become major measures to determine the success or failure of the project, the research interested in these elements by a thorough study of references related to the success of a constructional project. To reinforce the theoretical study a field assessment of the housing project; this led to the recognition of the major elements that caused breaches of the evaluation criteria. The closed questionnaire and the regular forms based on the data and information collected through the theoretical review and the closed questionnaire to conclude and examine some concepts related by assessing the quality of building materials used in residential investment projects through the stages (planning - design-implementation)Through the research a lot of deductions were made, the most important is that there cannot be an evaluation system without having a holistic monitoring system in Iraq. It was also deduced that the most important source of project failure is not allocating enough time to the planning phase. Some other recommendations and suggestions for future studies were made also.

إن المشروع الإنشائي بطبيعته هو عمل معقّد جداً، ويتطلب معرفة متخصصة لتقوده نحو النجاح. فالمشروع الإنشائي معقّد إجتماعياً وتقنياً وإقتصادياً في التخطيط والإدارة والتنفيذ وذلك لكثرة المتغيرات وتعدد الأطراف فضلا عن تأثره بشكل مباشر بالبيئة المحيطة به.تعتمد المشاريع الناجحة على ثلاثة مرتكزات أساسية هي الكلفة والوقت وتحقيق المواصفات. تهدف أطراف المشروع الى تحقيق المواصفات والأداء الوظيفي الأفضل ضمن الوقت والكلفة المتعاقد عليها ولكن يبقى السؤال القائم، هل تم التوصل الى الحالة المثالية لتنفيذ المشروع ؟ إن نجاح المشروع يبقى رهينة بالعمل اليومي ضمن نشاطات المشروع وبكيفية إدارة هذه النشاطات من الأطراف الثلاثة المشتركة (المقاول، صاحب العمل، الإستشاري) ومقدرتهم العلمية والعملية في الوصول الى توازن مرتكزاته الثلاثة (الكلفة والوقت والنوعية)، مع الأخذ بنظر الإعتبار الأهداف الرئيسة التي وضعها صاحب العمل للمشروع. بغض النظر عن الطريقة أو إطار العمل وإدارته وبغض النظر عن عدد الخطوات الرئيسية ، إن نجاح اي مشروع أو فشله يعتمد على مجموعة مشتركة من العوامل التي تمثل معايير رئيسية لذا إهتم البحث بدراسة هذه المعايير وذلك من خلال دراسة شاملة للأدبيات ذات الصلة بمعايير نجاح المشروع الإنشائي. ولغرض دعم الدراسة النظرية تم إجراء دراسة ميدانيه تمثلت من خلال مسح ميداني لـ مشروع سكني والتعرف على اهم العوامل التي تسببت في حدوث التجاوزات على أهداف التقييم، القيام باستبيان مغلق وتحليل ثم تصميم استمارة الاستبيان المغلق النظامية بالاعتماد على ما جمع من بيانات ومعلومات من خلال الدارسة النظرية ،للتعرف والتحقق من بعض الامور المتعلقة بواقع تقييم نوعية مواد البناء المستخدمة في المشاريع الاستثمارية السكنية خلال مراحل (التخطيط - التصميم-التنفيذ). من خلال البحث تم التوصل الى العديد من الإستنتاجات أهمها: إنه لايمكن إن يكون هنالك نظام للتقييم دون وجود نظام متابعة متكامل. كما واستنتج البحث الى إن أهم مصادر فشل المشروع هو عدم منح العملية التخطيطية الوقت الكافي ، فضلا عن مجموعة من التوصيات والمقترحات لدراسات وبحوث مستقبلية.


Article
Effect of Wax Burn-Out Heating Temperature on The Compressive Strength of Casting Dental Alloy Investment

Author: Lamia T Rejab
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2008 Volume: 8 Issue: 16 Pages: 197-204
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate the effect of the burn-out heating on the compressive strength of investment materials.Materials and Methods: Three commercial investment materials were used in this study. Seventy two cylindrical shape specimens were prepared to evaluate the compressive strength of the investment materials at room temperature (cold strength) and at two different burn-out heating temperatures : 700 oC and 1000 oC (hot strength). Three groups were prepared according to tested investment materials, The specimens were then subdivided into three subgroups according to burn-out heating temperatures,eight specimens for each subgroup. The compressive strength (kg /cm2) was evaluated by using Instron testing machine. Mean values were compared statistically with one way analysis of variance (ANOVA),Duncan , s multiple range test and t-test to determine the significant difference among the tested groups at (p<0.05) level of significance .Results: The results showed that there is a significant difference of the means value of the compressive strength among the three tested investment materials. The compressivestrength value significantly decreased with increasing burn-out heating temperature. Conclusion:The result of this study showed that the increase of burn-out heating had a significant decrease the compressive strength of the investment materials, and cold compressive strength gives an indicationof the hot strength .


Article
Effect of Different Dental Materials on the Surface Roughness of Acrylic Resin ( A comparative in vitro study )

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Article
Evaluation of the effects of an Iraqi phosphate bonded investment and two commercial types on the marginal fitness of porcelain- fused- to- metal copings .

Authors: Ma'an Rasheed Zakaria, B.D.S, M.Sc د. معن رشيد --- Ahmed Gazi Subhy, B.D.S, M.Sc *. د. ا حمدغازي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2005 Volume: 2 Issue: 2 Pages: 183-193
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The effect of different phosphate- bonded investments on the marginal fitnessof porcelain- fused—to-metal copings cast by one type of noble alloy and one type ofbase metal alloy was studied. Three types of phosphate—bonded investments (Castorit -Super C, Norvest, and Iraqivest) were used for investing the thirty copings of eachgroup. The marginal fitness of each coping was determined by measuring the verticalmarginal discrepancies between the gingival margin of the coping and the margin ofthe preparation at four reference points on the labial, mesial, palatal and distal aspectsof the die by the aid of light traveling microscope .The statistical analysis of the results showed that there were significantdifferences in marginal fitness among different investments for both Pd- Ag& Ni-Cralloys. The Castorit- Super C and Norvest investments produced comparable resultswith both alloys, while the Iraqivest appeared less compatible with Pd-Ag alloy thanthe other two investments and it had comparable compatibility to Norvest investmentwhen used with Ni- Cr alloy. The Ni- Cr alloy (Heraenium NA) copings revealedsignificantly greater marginal discrepancy than the Pd-Ag alloy (QD) eopingsspecially when using Castorit- Super C and Norvest investments .


Article
The Effects of Different Investment Materials on Dimensional Accuracy and Surface Roughness of Thermosens Maxillary Complete Dentures

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Background: Limited data are available on the dimensional stability and surface roughness of ThermoSens, which is a material used in denture processing. This study aimed to measure the vertical teeth changes and surface roughness of ThermoSens dentures prepared using three different investment materials.Materials and methods: For the dimensional changes test, 30 complete maxillary dentures were prepared using different investment methods: group I, dental stone; group II, silicone putty; and group III, a mixture of dental stone and plaster (ratio, 1:1; n = 10 for each group). Four screws were attached to the dentures: two were attached to the buccal surface of the canine and first molar, and the other two were attached in the flange areas of the canine and first molar in line with the previously mentioned screws. Measurements were made using a micrometer microscope in the wax stage before flasking and in the deflasking stage. The above investment techniques were also used to prepare samples for a surface roughness test (n = 10 per group). These samples were prepared according to the specifications of the American Dental Association. Data were examined using analysis of variance (ANOVA) and the least significant difference (LSD) test.Results: One-way ANOVA and LSD revealed that dimensional changes significantly differed among all groups, except that the vertical teeth changes on the left side did not differ between groups I and II for both the canine and molar regions. Surface roughness was significantly higher in group I than in group II, and in group III than in group II.Conclusion: The use of putty silicone for investing ThermoSens complete dentures reduced dimensional changes and resulted in dentures with a better fit. Surface roughness could be reduced by the addition of a putty silicone layer over the denture before the addition of the second investment layer during denture processing


Article
The effect of additives on the linear thermal expansion of Phosphate-bonded investment

Authors: Dr. Mohammed K. Gholam, B.D.S., M.Sc.** د.محمد قيس --- Dr. Ammar A. Alsa'ady, B. D.S., M.Sc., Ph. D.* د. عامر السعدي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2008 Volume: 5 Issue: 1 Pages: 7-13
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

One of the main considerations of the investment materials is there adequacy to expand thermally and by setting expansion to compensate for casting shrinkage, and any investment having zero setting expansion and adequate thermal expansion, by the use chemical additives and water instead of colloidal silica suspension would eliminate all inaccuracies arises from distortion of the wax pattern due to setting expansion.Thus the aim of this study was to evaluate the influence of two alkaline metals as additives K2SiO3 and Na2SiO3, to enhance the thermal expansion of phosphate – bonded investment without the use of colloidal silica suspension.Three mixtures (45 samples) were prepared, mixture I of 15 samples contains Na2SiO3, Mixture II of 15 samples contains K2SiO3 in percentages of (0.5, 1.0, 1.5, 2.0, and 2.5) for each three samples of both (mixture I & II), and mixture III of fifteen samples as a control group without additives. The thermal expansion measured by vitreous silica dilatometer from 100 – 950 ºC.The results showed that the highest mean of thermal expansion was in samples that contain Na2SiO3, and the lowest mean of thermal expansion was in the control group samples.


Article
Economic analysis of the most important factors influencing investment allocations for agricultural reclamation in Iraq . (2010 - for the period (1990
تحليل اقتصادي لأهم العوامل المؤثرة في التخصيصات الاستثمارية للاستصلاح الزراعي في العراق . (2010- للمدة ( 1990

Authors: Ali Salah Shokr علي صلاح شكر --- Iskandar Ali Hussein اسكندر حسين علي
Journal: Diyala Journal of Agricultural Sciences مجلة ديالى للعلوم الزراعية ISSN: 20739524 Year: 2013 Volume: 5 Issue: 2 Pages: 264-274
Publisher: Diyala University جامعة ديالى

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Abstract

Investment business positive economic consequent increase in fixed capitaland operating the basis of considering the problem of salinity is one of the mostimportant problems facing Iraqi agriculture, which leads to low productivity perunit area, which in turn led to the lower contribution of agricultural output ofGNP as was the reason for exit area wide range of land-scale agriculture,economic, so the aim of research is to conduct an economic analysis ofinvestment in land reclamation in Iraq for the period (2010 -1990), and reviewthe reality of reclamation within this period show that the average areasreclaimed amounted to 275214.6 donum and the largest area reclaimed was in2002, and through the annual growth rates show that the rate of growth duringthe period( 1990 - 2010)) which is half the duration of the study was positive,but the second period was the growth rate which is negative due to thecontinuing decline in allocations to invest in this area, as it turns out that thehighest percentage contribution to the output of the agricultural of GDP was26.9% during 1991 either lower the contribution rate in 2010 was at 7.2%. Inorder to identify the most important factors affecting the investment allocationsfor reclamation projects agriculture was estimated function of investment thatshow the relationship between investment allocations as the dependent variableand all of the GDP at constant prices and agricultural output in constant pricesand area reclaimed donums explanatory variables and using the method of leastsquares OLS found that the linear function was the appropriate functions to beused expression of the relationship to overcome the of economic and statisticaland econometrical tests standard and GDP was the most influence anddetermine the amounts allocated for investment as the change by one unit of theinvestment allocations will change by 147.9 with the survival of other factorsconstant at averages, and was able to variables explanatory explain 67% of thefluctuations in the depended v. F-test also showed significant model as all.

الاستثمار عمل اقتصادي ايجابي يترتب عليه زيادة رؤوس الأموال الثابتة والعاملة وانطلاقا مناعتبار إن مشكلة الملوحة واحدة من أهم المشاآل التي تواجه الزراعة العراقية والتي تؤدي إلى انخفاضإنتاجية وحدة المساحة التي أدت بدورها إلى انخفاض مساهمة الناتج الزراعي من الناتج القومي الإجماليآما آانت سبب في خروج مساحات واسعة من الأراضي على نطاق الزراعة الاقتصادية ، لذلك هدفالبحث إلى إجراء تحليل اقتصادي للاستثمار في استصلاح الأراضي الزراعية في العراق للمدة (- 20101990 ) ، وباستعراض واقع الاستصلاح ضمن هذه الفترة تبين أن متوسط المساحات المستصلحة بلغ275214.6 دونم وان اآبر مساحة مستصلحة آانت في عام 2002 ,ومن خلال معدلات النمو السنوي2000 وهي نصف مدة الدراسة آان موجبا أما الفترة الثانية آان - تبين أن معدل النمو خلال الفترة 1990معدل النمو فيها سالبا بسبب الانخفاض المستمر في تخصيصات الاستثمار في هذا المجال ، آما اتضح أنأعلى نسبة إسهام للناتج الزراعي من الناتج المحلي الإجمالي آانت 26.9 % خلال عام 1991 إما اقلنسبة إسهام آانت عام 2010 إذ بلغت 7.2 % . بغية التعرف على أهم العوامل المؤثرة على التخصيصاتالاستثمارية لمشاريع الاستصلاح الزراعي تم تقدير دالة الاستثمار التي توضح العلاقة بين التخصيصاتالاستثمارية آمتغير تابع وآل من الناتج المحلي الإجمالي بالأسعار الثابتة والناتج الزراعي بالأسعارOLS الثابتة والمساحات المستصلحة بالدونم آمتغيرات توضيحية وباستعمال طريقة المربعات الصغرىوجد إن الصيغة الخطية هي أفضل الصيغ تعبيرا عن العلاقة لاجتيازها الاختبارات الاقتصاديةوالإحصائية والقياسية وآان الناتج المحلي الإجمالي الأآثر تأثير وتحديد للمبالغ المخصصة للاستثمارحيث إن تغير بمقدار وحدة واحدة فأن التخصيصات الاستثمارية ستتغير بمقدار 147.9 مع بقاء العواملالأخرى ثابتة عند المتوسطات ,واستطاعت المتغيرات التوضيحية تفسير 67 % من التقلبات في العاملمعنوية الأنموذج آكل .


Article
Teeth Displacement and Palatal Adaptation of Autoclave Cured acrylic resin with Various Palates and Investments

Authors: Abdalbasit A Fatihallah عبد الباسط احمد عبد الفتاح --- Rola W.A رولا وليد --- Ali N.A علي نعة
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 1 Pages: 1-10
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The denture base inaccuracies during processing negatively influence the retention and stability offinished complete denture. The aims of this study were to evaluate teeth movement and palatal adaptation ofautoclave cured denture bases and their relationship with palatal depths and investments.Materials and methods: A nightly maxillary complete dentures prepared, processed and organized to be tested asfollows: 1. Processing methods: water bath and autoclave with both fast and slow cycles. 2. Palatal depth: shallow,medium and deep. 3. Investing medium: stone and silicone. For every finished denture, two measurements weredone: first: teeth movement by attaching metallic reference screws on the right and left centrals, first premolars andsecond molars. Second: palatal adaptation by sectioning the posterior part of the denture and measuring thedistances between five selected points which were on the right and left: ridge crest, center of the vestibule andmiddle of the palate. Then two measurements were done before and after curing by using travelling microscope of0.001% of accuracy. The collected data organized statistically by three ways analysis of variance for curing methods,investments and palatal depth. Also, least significant test and t test for detection of difference.Results: High significant improvements in dimensional stability shows when autoclave was used compared with thewater bath. Results show that autoclave curing reduces the amount of teeth movements and improves palataladaptation with silicone investment compared with stone.Conclusions: resin curing by autoclave is a better alternative to water bath. The dimensional stability were improvedespecially when silicone were used instead of stone


Article
THE SHARIAH LIMITATIONS TO INVEST ZAKAT FUNDS IN DEVELOPMENT PROJECTS
محددات الشريعة لاستثمار أموال الزكاة في المشاريع التنموية

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This research clarified the limitations of the Islamic law in investment the Zakat money in the development projects, and also showed the role that Zakat plays in the development of the Islamic society in general. The focus was on the economical part by discussing the following issues: Firstly: the role of the Zakat in financing the poor and the needy professionals by the required machines and tools. Secondly: the role of the Zakat in helping the affected businessmen from the financial crises. Thirdly: the role of the Zakat in financing productive projects and titled to the beneficiaries.

أوضح هذا البحث محدودية الشريعة الإسلامية في استثمار أموال الزكاة في مشاريع التنمية، وأظهر أيضا الدور الذي تلعبه الزكاة في تنمية المجتمع الإسلامي بشكل عام. وكان التركيز على الجزء الاقتصادي من خلال مناقشة القضايا التالية: أولاً: دور الزكاة في تمويل الفقراء والمحتاجين من المهنيين بالآلات والأدوات المطلوبة. ثانياً: دور الزكاة في مساعدة رجال الأعمال المتضررين من الأزمات المالية. ثالثاً: دور الزکاة في تمویل المشاریع الإنتاجية تحت عنوان المستفیدین.

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