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Article
Artificial saliva sorption for three different types of dental composite resin (An in vitro study)

Authors: Rajaa T. Sulieman --- Amer A Taqa
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2011 Volume: 11 Issue: SpIss Pages: S296-S302
Publisher: Mosul University جامعة الموصل

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Abstract

Aims: To evaluate the artificial saliva sorption for three different types of light activated composite resin. Materials and Method: A total of thirty six specimens (bars) (3x8x15)mm were prepared from three different types of light activated composite resin. (Tetric N-ceram, Iv o clar-vivadent-Liechtenstein. Arabesk – voco – Germany. Soltaire–2, Heraeus, kulzer, Germany). Twelve specimens were prepared from each type of composite resin. Complete fabrication of composite resin specimens, polished and kept in three different types of artificial saliva medium, three specimens from each type of composite resin as interactive specimens kept in type of artificial saliva and the last three specimens kept in Deionized water as control medium. The weight of each specimens was measured at an analytic balance before and after different time intervals of storage (1,2,7,21,35,60) days to measure the amount of absorption of artificial Saliva (gaining and loss of weight). The study showed a significant difference (P< 0.05) in artificial saliva sorption among the three different types of composite resin at different time intervals when kept in different artificial saliva medium. Tetric N-ceram (nano composite) has more affect with three different types of artificial saliva medium (gaining and loss weight) followed by Arabesk, Soltaire-2 composite resin for different types of artificial saliva at different time intervals. Conclusion: Dental composites are sensitive to artificial salive medium (gain and loss of weight) Tetric N ceram (nano – composite) interact actively followed by Arabesk and Soltaire-2 for three different artificial saliva medium at different time intervals


Article
Treatment of Low– And Intermediate– Level Radioactive Liquid Waste from Altwatha Site Using Iraqi Zeolite

Authors: Yasamen A.Aziz --- Adnan H. Afaj --- Maysoon Jawdat Zaiter
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2007 Volume: 13 Issue: 1 Pages: 1237-1250
Publisher: Baghdad University جامعة بغداد

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Abstract

Ion exchange material used in this study is synthetic inorganic resin. It is Iraqi synthetic zeolite type Na-A, which was prepared from Iraqi kaolinite. The prepared zeolite pellets were solidified by heat treatment at 600 °C for 3 hours.Nine radiochemical experiments were carried out on real (radioactive) samples. Five of these experiments were to study the uptake rate (sorption rate) of cobalt-60. The measured value for equilibrium time was one hour. The other experiments were carried out to obtain sorption isotherm using batch test. The product cobalt concentration was fitted to Langmuir and Freundlich isotherms as followed respectively: x/m = 1.25 Ce / (1+6*10^4 Ce) x/m = 8*10^-4 Ce^0.4Gamma spectrometry analysis system of Sodium Iodide (NaI) detector coupled with a multichannel analyzer, was used for the measurements of radioactivity of the samples pre- and after treatment with zeolite. In general the experimental results have shown an efficient performance of the Iraqi zeolite to remove different cobalt concentration from low- and intermediate- level radioactive liquid waste.

مادة المبادل الايوني المستخدمة في هذا البحث هو نوع صناعي لا عضوي, زيولايت نوع Na-A المحضر من الكاؤلين العراقي. حبيبات الزيولات تم تصليبها بالتسخين لدرجة 600°م ولمدة ثلاث ساعات. تسعة تجارب أجريت على نفايات سائلة مشعة مأخوذة من موقع التويثة. قسم من هذه التجارب (خمسة ) لدراسة معدل الامتزاز (Sorption rate), وتبين أن الفترة الزمنية اللازمة للوصول إلى حالة التوازن هي ساعة واحدة. التجارب الباقية ( أربعة) فقد أجربت لدراسة علاقة التوازن بثبوت الحرارة (Sorption Isotherm). ووجد أن العلاقة مطابقة لمعادلتي لانكمير (Langmuir) وفرندلش (Friendliest) وحسب ما يلي:- (x/m = 1.25 Ce / (1+6*10^4 Ce x/m = 8*10^-4 Ce^0.4 التحليل للنماذج أعلاه تم باستخدام جهاز قياس أطياف أشعة كاما المعتمد على الكاشف الوميضي أيود يد الصوديوم (NaI) المرتبط بمحلل متعدد القنوات (Multichannel Analyzer). النتائج أظهرت كفاءة الزيولايت العراقي نوع Na-A في إزالة النظير المشع Cobalt-60 من النفايات السائلة ذات النشاط الإشعاعي الواطئ والمتوسط


Article
Measurement of water sorption of five different composite resin materials

Author: Waleed M. Khalil وليد خليل
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2005 Volume: 17 Issue: 3 Pages: 37-41
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Water sorption may affect composite resin materials by reducing their mechanical properties and wear resistance .The aim of this study is to measure the water sorption of five different composite resin materials, for different time intervals.Materials and methods: A stainless steel mold of 4 mm width, 8 mm length and 4 mm depth was constructed to form composite blocks. Seven blocks were made of each test resin composite material. All specimens were placed in a silica-gel desiccator for 48 hours. The samples were then weighed thrice using calibrated electronic microbalance, the average reading was recorded to the nearest 0.0001g. The specimens were kept in individual containers in deionized distilled water at 37 ºC.All specimens were periodically weighed. The weight measurements were taken at 2, 8, 14, 28,42,56,70,100,150 and 240 days intervals.Results: The statistical analysis of the results showed that all composite resin specimens continued to gain weight for a period of 28 days. After that period, the weight gain continued, although at a reduced rate. The changes after the 28 days period were small for the Herculite XRV, Tetric ceram and Tetric composite resins, and greater for the Filtek P60 and Composan LCM composite resins.Conclusion: In this study water absorption increased steadily for all materials. The percentage weight change showed a tendency to increase with the time of water storage. This study concludes that over a period of 8 months, the differences in water sorption capacity of the five composite resin materials are related to the differences in the amount of filler loading in the composite resin matrix. With one exception, the composite resin materials with the largest quantity of fillers had the least water sorption capacity after eight months of storage in water


Article
Water sorption of three types of composite resins

Authors: Dr. Samar Abdul Hamed Yasin. B.D.S, M.Sc د. سمر عبد الحميد --- Dr. Linz Ali Shalan. B.D.S, M.Sc.. د. لنز علي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2011 Volume: 8 Issue: 3 Pages: 242-247
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Silorane low shrink composite resin material introduced with a non-methacrylateresin matrix to realize a fundamental improvement in cure shrinkage, clinical andphysical properties. The aim of this study is to measure the water sorption of threetype of composite material: Filtek P90, Filtek P60, IPS Empress composites afterimmersion in deionized distilled water as a function of time.Thirty disk shape plastic molds (4 mm diameter and 2mm thickness) wereconstructed to form composite blocks. Teen blocks were made from Filtek P 90(Silorane) GI, Filtek P 60 (packable) GII and IPS Empress (Nanohybrid) GIII. Allspecimens were placed in a silica-gel desiccator for 48 hours. The samples were thenweighed three times using calibrated electronic microbalance and the average readingwas recorded to the nearest 0. 0001g then specimens were kept in individualcontainers in deionized distilled water at 37 oC. All specimens were periodicallyweighed. The weight measurements were taken from the second day after incubationand continue as one measurement every week for 6 weeks. Data were subjected tostatistical analysis using descriptive analysis, ANOVA and least significantdifferences LSD test.Statistical analysis of the results showed that all the specimens continued to gainweight for a period of 4 weeks. After that period the weight gain continued, althoughat reduced rate. Filtek P90 (Silorane) GI has highly significant less water sorptionvalue ( p < 0.01) than the other groups after 6 weeks, while there was no significantdifferences ( p > 0.٠٥) between IPS Empress (Nanohybrid ) GIII and Filtek P60 (Packable ) GII in their water sorption value with higher value for GIII.Silorane which based on siloxane and oxirane resin matrix has less value after 6weeks followed by Packable composite while IPS Empress has higher value for watersorption. This study concluded that the differences in water sorption capacity of thethree composite resin materials are related to the differences in the type of resinmatrix, the amount of filler loading and filler particle size.


Article
Water sorption of light–cured composites

Author: Ammar Kh Al–Nori
Journal: Al-Rafidain Dental Journal مجلة الرافدين لطب الأسنان ISSN: 18121217 Year: 2005 Volume: 5 Issue: 5 Pages: 1-5
Publisher: Mosul University جامعة الموصل

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Abstract

The aim of the present research was to study the percentagewater sorption and solubility of Esthet compositeresin based on an ethoxylated bisphenol A glycol dimethacrylate(Bis–EMA) and Heliomolar composite resin basedon bisphenol A glycol dimethacrylate (Bis–GMA). Six specimenswere prepared for each material using aluminum disc 15mm in diameter and 1 mm in thickness between two glassslides; then they were light cured for 80 seconds on each side.Percentage water sorption and solubility were measured afterone week and one month. The results showed that water sorptionafter 1 week for Esthet composite and Heliomolar compositewere 0.433 and 1.12, respectively and solubility were0.074 and 1.066, respectively; while water sorption after 1month were 0.517 and 2.57, respectively and solubility were0.176 and 2.689, respectively.It could be concluded that the percentage sorption andsolubility of composite based on Bis–EMA were significantlylower than that based on Bis–GMA.


Article
Sorption Study of Methyl Orange on the Iraqi Kaolinite Clay

Author: Ali A. Al-Ma'amar
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2012 Volume: 15 Issue: 4 Pages: 98-103
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

The sorption of methyl orange on the kaolinite clay was studied thermodynamically and kinetically, the sorption was of Freundlich type and the multi-layers were formed, and the sorption was a combination of adsorption and absorption, but in some cases the desorption was occurred. The Freundlich constants were calculated to specify the sorption capacity, and sorption intensity. The calculation of thermodynamic parameters revealed that the process was exothermic, ordered, and non-spontaneous at the temperature range(298-328K). Three kinetic models were exploited to calculate the rate constant, diffusion constant, rate of adsorption, and desorption parameter.

تمت دراسة امتزاز المثيل البرتقالي على طين الكاؤلين دراسة حركية وثرموديناميكية, ولقد كان الامتزاز من نوع فرويندلش وتكونت عدة طبقات للامتزاز على سطح المادة المازة, وقد كانت العملية عبارة عن خليط بين الامتزاز والامتصاص, ولكن في بعض الحالات حصلت عملية الابتزاز. تم حساب ثوابت فرويندلش لغرض تحديد سعة الامتزاز وشدتة على السطح, وايضا تم حساب المعاملات الثرموديناميكية وقد بينت ان عملية الامتزاز كانت باعثة للحرارة, ومنظمة, وغير تلقائية ضمن المدى الحراري (298-328 كلفن). تم استخدام ثلاث اشكال حركية لغرض حساب ثابت سرعة العملية, وثابت الانتشار, معدل عملية الامتزاز, ومعامل الابتزاز.


Article
An evaluation of water absorption of Giomer in comparison to other resin-based restorative materials

Authors: Shatha Abdul Kareem شذى عبد الكريم --- Rasha H. Jehad رشا جهاد
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 3 Pages: 25-28
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: Polymeric composites have been widely used as dental restorative materials. A fundamentalknowledge and understanding of the behavior of these materials in the oral cavity is essential to improve theirproperties and performance. The goal of this study was to measure water sorption of four composite resinscontaining different filler and resin matrix contents.Materials and method: Resin composite specimens giomer (Beautifil II) Filtek™ P90, Filtek™ Z350 XT, and Tetric NCeramwere prepared in a cylindrical mould of 3mm thickness and 6mm diameter (n=10) and light cured . Allspecimens placed in silica-gel desiccators at 37˚C for seven days, a constant weight was obtained. All samples wereimmersed in deionized distilled water at 37˚C and weighed at suitable time interval once a week for 30 days. Watersorption was calculated based on ISO 4049. Data were subjected to student t- test.Results: Silorane and Giomer composites showed the lowest values of water sorption, while Z350 and Tetric N-Ceramdisplayed the highest values at a period of 4 weeks.Conclusion: Each resin- matrix composite varied in water sorption which may affect clinical service. The attainedwater sorption values are mainly influenced by the generic type of material and variations occurring betweenmaterials of the same type may result from differences in resin matrix compositions


Article
Treatment of radioactive liquid waste using Iraqi geological raw materials and zeolite
معالجة النفايات السائلة المشعة باستخدام مواد جيولوجية خام عراقية و الزيولايت

Authors: Abbas H. Sulaymon عباس حميد سليمون --- Adnan H. Afaj عدنان حسن عفج --- Haidar M. Rasheed حيدر محسن رشيد
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2013 Volume: 16 Issue: 1 Pages: 58-66
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

A radioactive liquid waste contaminated with cesium-137 was found underneath a destructed radioactive waste treatment station in Tuwaytha site 25 km south of Baghdad - Iraq. The appropriate sorbent materials found for the removal of radio cesium-137 were bentonite and modified bentonite with corresponding removal efficiencies of 85% and 91.8% respectively. The favorable batch experimental conditions were found to be 800 rpm stirring speed, 200 mg sorbent mass, 45µm sorbent particle size, and solution temperature of 30 oC for an initial radio cesium concentration of 0.44 mg/l.The BET isotherm model was found to represent the experimental results very well.

هنالك نفايات سائلة مشعة تحتوي على السيزيوم - 137 وجدت تحت انقاض محطة معالجة النفايات المشعة المدمرة في موقع التويثة والذي يبعد 25 كم جنوب بغداد في العراق.ان البنتونايت و البنتونايت المحور هو من انسب المواد المازه والتي تقوم بإزالة السيزيوم المشع بكفاءة إزالة 85% و 91.8% على التوالي.ان الظروف التجريبية المفضلة هي 800 دوره في الدقيقة كسرعة خلط, 200 ملغم من المادة المازه, 45 مايكرومتر للحجم الحبيبي للمادة المازه, درجة حرارة المحلول 30 مئوي لتركيز أولي للسيزيوم المشع 0.44 ملغم لكل لتر.يعتبر نموذج (BET) من افضل النماذج التي تمثل النتائج التجريبية بشكل جيد.


Article
Treatment of radioactive liquid waste using Iraqi geological raw materials and zeolite
معالجة النفايات السائلة المشعة باستخدام مواد جيولوجية خام عراقية و الزيولايت

Authors: Abbas H. Sulaymon عباس حميد سليمون --- Adnan H. Afaj عدنان حسن عفج --- Haidar M. Rasheed حيدر محسن رشيد
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2013 Volume: 16 Issue: 1 Pages: 58-66
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

A radioactive liquid waste contaminated with cesium-137 was found underneath a destructed radioactive waste treatment station in Tuwaytha site 25 km south of Baghdad - Iraq. The appropriate sorbent materials found for the removal of radio cesium-137 were bentonite and modified bentonite with corresponding removal efficiencies of 85% and 91.8% respectively. The favorable batch experimental conditions were found to be 800 rpm stirring speed, 200 mg sorbent mass, 45µm sorbent particle size, and solution temperature of 30 oC for an initial radio cesium concentration of 0.44 mg/l.The BET isotherm model was found to represent the experimental results very well.

هنالك نفايات سائلة مشعة تحتوي على السيزيوم - 137 وجدت تحت انقاض محطة معالجة النفايات المشعة المدمرة في موقع التويثة والذي يبعد 25 كم جنوب بغداد في العراق.ان البنتونايت و البنتونايت المحور هو من انسب المواد المازه والتي تقوم بإزالة السيزيوم المشع بكفاءة إزالة 85% و 91.8% على التوالي.ان الظروف التجريبية المفضلة هي 800 دوره في الدقيقة كسرعة خلط, 200 ملغم من المادة المازه, 45 مايكرومتر للحجم الحبيبي للمادة المازه, درجة حرارة المحلول 30 مئوي لتركيز أولي للسيزيوم المشع 0.44 ملغم لكل لتر.يعتبر نموذج (BET) من افضل النماذج التي تمثل النتائج التجريبية بشكل جيد.


Article
KINETICS OF HYDROGEN SEPARATION FROM REFINERY OFF-GAS

Authors: Abbas Khalaf MOHAMMAD --- Nawras Shareef SABEEH
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2018 Volume: 11 Issue: 3 Pages: 396-409
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

Adsorption and desorption kinetic curves for equimolar hydrogen – methane mixture on molecular sieve type 5A were experimentally obtained for pressure range 0.122 – 3.546 MPa.The linear driving force rate expression model was used to simulate the dynamic of adsorption and desorption in adiabatic fixed bed adsorber. The model takes into account the interference effects for non-linear isotherms and non-isothermal system. The equations were solved by backward finite difference method with a fixed gridding technique. The individual mass transfer parameters were obtained by matching the theoretical with the experimental data and found to be equal to 8.510 s-1 and 0.783 s-1 for hydrogen and methane, respectively.The predicted effluent histories were shown to be in close agreement with the experimental data for the system. The lowest relative capacity of the bed for methane was almost approximately 95% of that predicted equilibrium capacity. The predicted temperature profiles tracked the experimental temperature data points, but with higher values. Furthermore, the maximum temperature increasing was observed for the adsorption of methane onto 5A molecular sieve at 35 atmospheres and was recorded as 44 K.

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