research centers


Search results: Found 6

Listing 1 - 6 of 6
Sort by

Article
Fractal Nanotechnology (Invited Paper)

Authors: G. Ceroflini --- D. Narduci --- P. Amato --- E. Romano
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2008 Volume: 4 Issue: 4 Pages: 25-29
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

Loading...
Loading...
Abstract

Self-similar patterns are frequently observed in Nature. Their reproduction is possible on a length scale 102–105 nm with lithographic methods, but seems impossible on the nanometer length scale. It is shown that this goal may be achieved via a multiplicative variant of the multi-spacer patterning technology, in this way permitting the controlled preparation of fractal surfaces.


Article
ELECTROLYTIC PREPARATION OF COPPER POWDERWITH PARTICLE SIZE LESS THAN 63µm
التحضير الكهروكيميائي لمسحوق النحاس بحجم حبيببي اقل من(63µm )

Author: Ali H. Abbar
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2008 Volume: 1 Issue: 1 Pages: 32-45
Publisher: Al-Qadisiyah University جامعة القادسية

Loading...
Loading...
Abstract

An electrochemical cell consisting of two electrodes (Lead-6%antimony alloy cathode and copper anode, (99.9%)) was used to study the electrolytic preparation of copper powder with particle size less than (63µm) directly as powdery form. Copper sulphate dissolved in sulfuric acid solution was used as electrolyte. The produced powder was thoroughly washed with an acidified distilled water and absolute ethanol, then dried under an inert atmosphere at 80oC, and classified by screening. Samples of prepared powder were taken to determine their purity by atomic absorption. The effects of current density, metal ion concentration, sulfuric acid concentration, and electrolysis time on the weight percent of copper powder less than (63µm), yield and current efficiency were studied.
It was found that copper powder with particle size less than (63µm) can be prepared at a weight percent (79.7% ) and current efficiency( 75%) using cathode current density (0.16 A/cm2),copper ion concentration(5gm/l),sulfuric acid concentration(100gm/l)temperature(25-30oC)and electrolysis time equal to(2hr). The prepared powder having an apparent density (2.24 gm/cm3) and specific surface area (421 X 103 cm2/gm). Its average particle size was (42 µm) and its purity was (99.7%)

تم استخدام خليه كهروكيميائيه مؤلفه من قطبين احداهما كاثودي مصنوع من سبيكه رصاص-6%انتيمون والأخر انودي مصنوع من النحاس ذو نقاوة (99.9%) .تم استخدام الكتروليت من كبريتات النحاس مذابه في حامض الكبريتيك.المسحوق الناتج تم غسله جيدا بماء محمض ومقطر ومن ثم بالأيثانول ثم تجفيفه تحت جو خامل بدرجة حراره (80oC)تبع ذلك تصنيفه حسب الحجم الحبيبي .تم اخذ نماذج من المسحوق المحضر وحددت نقاوته باستخدام تقنية الأمتصاص الذري .تم دراسة تاثير كل من كثافة التيار,تركيز ايون النحاس ,تركيز حامض الكبريتيك وزمن التحلل الكهربائي على النسبه الوزنيه للمسحوق الناتج ذو الحجم الحبيبي الأقل من (63µm ),الأنتاجيه,وكفائة التيار وجد انه بالأمكان تحضير مسحوق النحاس ذو الحجم الحبيبي الأقل من(63µm) بنسبه وزنيه لاتقل عن(79.7%) وكفائة تيار (75% )عند استخدام كثافة تيار (0.16 A/cm2 )وتركيز ايونات النحاس(gm/l 5) مذابه في حامض الكبريتيك ذو تركيز (l 100gm/ ) وإجراء عملية التحلل اكهربائي بدرجة حراره(25-30oC) بزمن تحلل (2hr. ).المسحوق المحضر عند هذه الظروف كانت كثافته الظاهريه (2.24 gm/cm3 ) و ذو مساحه سطحيه نوعيه (421 X 103 cm2/gm ) ومعدل حجم حبيبي (42 µm )ونقاوه (99.7% ) .


Article
Microleakage after root canal preparation with rotary and hand ProTaper system (in vitro study)

Authors: Dr. Iman M. Al-Zaka. د.ايمان محمد --- Dr. Hikmet A.Sh. Al-GharrawI د.حكمت عبد الرحيم --- Dr. Jamal A. Mehdi. د. جمال عزيز مهدي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2008 Volume: 5 Issue: 2 Pages: 121-126
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

Seventy canals from 35 mesial roots of extracted human mandibular molars were selected and divided into 2 groups. The group I was prepared mechanically with ProTaper system. And group II was prepared with hand ProTaper files. All canals were obturated with Thermafil technique and Topseal sealer. Apical microleakage and the time for preparation were recorded in each sub group. Five molars were used as control teeth. All specimens were stored in 100% humidity, and were suspended in methylene blue dye for 72h. Linear dye leakage was statistically different (T-test), while time preparation between two groups was not statistically different.


Article
The effect of dowel space preparation on the apical seal of Resilon & Gutta-percha obturation materials. (An in vitro comparative study)

Authors: Prof. Dr. Abdul Karim J. Al-Azzawi, B.D.S., M.Sc. Abstract د. عبد الكريم العزاوي --- Dr.Saleh M. F. Al-Kasaki B.D.S د.صلاح القيسي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2008 Volume: 5 Issue: 4 Pages: 327-334
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

Aim: The aim of this in vitro study was to compare the effect of immediate versus delayed dowel space preparation using peeso reamers on the apical seal of roots filled by Gutta-percha with two types of resin based-sealers (AH26 and AH Plus) and by Epiphany obturation system.Methodology: Sixty freshly extracted human teeth with single and straight canals were used in this study. The roots were instrumented using the step-back technique, instrumentation was accomplished by using the Gates-Glidden drills with copious irrigation of 2.5% sodium hypochlorite and 17% solution of aqueous EDTA to remove smear layer. The roots were randomly divided into 3 main groups according to the type of obturation materials using lateral condensation technique (20 teeth for each group):Group A: Gutta-percha + AH26 root canal sealer.Group B: Gutta-percha + AH Plus sealer.Group C: Resilon+ Epiphany sealer+ prime. (Epiphany obturation system)Then each group divided into two subgroups according to the time of dowel space preparation either immediately after obturation or after one week. The external surfaces of all roots were coated by two layers of sticky wax except for the apical 2 mm and were then submerged in 2% methylene blue dye for 3 days at 37ºC. After that, all roots were longitudinally sectioned for linear measurement of dye penetration through the apical foramen using a stereomicroscope. The data obtained were analyzed statistically using ANOVA and Student t-tests.Results: Significantly less apical leakage in roots filled by gutta-percha with AH Plus than those filled by gutta-percha with AH26 and those filled by Epiphany obturation system for delayed dowel space preparation (P< 0.05) and there was a significantly less apical leakage in roots filled by Epiphany obturation system that prepared immediately after obturation than those received delayed preparation (P< 0.05).Conclusion: All the groups had apical leakage what ever the type of obturation material or time of dowel space preparation.


Article
The effect of immediate versus delayed dowel space preparation on the apical seal of Resilon/Epiphany obturation system

Author: Prof. Dr. Abdul Karim J. Al-Azzawi, B.D.S., M.Sc. عبد الكريم العزاوي
Journal: MUSTANSIRIA DENTAL JOURNAL مجلة المستنصرية لطب الاسنان ISSN: 18138500 Year: 2008 Volume: 5 Issue: 4 Pages: 335-340
Publisher: Al-Mustansyriah University الجامعة المستنصرية

Loading...
Loading...
Abstract

Aim: The aim of this in vitro study was to compare the effect of immediate versus delayed dowel space preparation using two techniques (peeso reamers and hot pluggers) on the apical seal of Resilon/ Epiphany obturation system.Methodology: Fifty freshly extracted human teeth with single and straight canals were used in this study. The roots were instrumented using the step-back technique, K-files with circumferential filing action and copious irrigation of 2.5% sodium hypochlorite and 17% solution of aqueous EDTA to remove smear layer. The canal obturation of all roots was performed with lateral condensation technique using Resilon/Epiphany Obturation system. Then the obturated roots were randomly distributed into 5 experimental groups (10 teeth for each group); one control group, and 4 experimental groups according to the technique of dowel space preparation (peeso reamers and hot pluggers) either immediately after obturation or after one week later. After this period, the external surfaces of all roots were coated by two layers of sticky wax except for the apical 2 mm and were submerged in 2% methylene blue dye for 3 days at 37ºC. Then all roots were longitudinally sectioned for linear measurement of dye penetration through the apical foramen using a stereomicroscope. The data obtained were analyzed statistically using ANOVA and Student t-tests.Results: Significantly more apical leakage (P<0.05) in groups that received delayed dowel space preparation using either peeso reamers or hot pluggers compared with control group and no significant differences (P>0.05) between immediate and delayed dowel space preparation using either technique.Conclusion: Resilon/ Epiphany obturation system can received immediate and delayed preparation using conventional methods of dowel space preparation, however immediate preparation was preferred according to the results of this experiment.


Article
Some Applications of High Performance Liquied Chromatography -Determination of Trimethoprim
بعض تطبيقات تقنية كروماتوغرافيا السائل ذو الكفاءة العالية تقدير التراي ميثوبريم

Author: Hana Sh. Mahmood هناء شكر محمود
Journal: Rafidain journal of science مجلة علوم الرافدين ISSN: 16089391 Year: 2008 Volume: 19 Issue: 3 E Pages: 1-9
Publisher: Mosul University جامعة الموصل

Loading...
Loading...
Abstract

A simple, fast and precise high performance liquid chromatographic method for the assay of trimethoprim in the presence of sulphamethoxazole has been developed. The procedure is based on using acetonitril: water: acetic acid in the ratio of 30:69.9:0.1 (v : v : v) as a mobile phase, flow rate (1ml/min.) and uv detector (254nm.).Each analysis required no longer than 10 minutes. the detector responses were linear in the range of 0.05-120µg/ml for trimethoprim with a relative standard deviation of 0.49-0.971% and a relative error of 1-2.5% . The proposed method was also applied satisfactorily to the pharmaceutical preparation.

تم تطوير طريقه سهله وسريعة وذات توافق عالي لتقدير الترايميثوبريم في مستحضره الصيدلاني باستخدام كروماتوغرافيا السائل ذو الكفاءة العالية والمزود بكشاف ضوئي. استخدم مذيب الاسيتونتريل:الماء: حامض الخليك بنسبه 30 : 69.9 : 0.1 (v : v : v) كطور متحرك وبمعدل جريان 1مل/دقيقة وتم القياس عند طول موجي 254 نانوميتر وكانت العلاقة خطية تتبع قانون بير لحدود تقدير بين (0.05 و 120) مايكروغرام/مل بالنسبة للترايميثوبريم مع انحراف قياسي نسبي يتراوح بين 0.49 و 0.97% وخطأ نسبي يتراوح بين 1 و 2.5 % .تم تطبيق الطريقة بنجاح لتقدير الترايميثوبريم في مستحضره الصيدلاني (الاقراص الدوائية).

Listing 1 - 6 of 6
Sort by
Narrow your search

Resource type

article (6)


Language

English (6)


Year
From To Submit

2008 (6)