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Article
Current-Voltage Characteristics of DC Plasma Discharges Employed in Sputtering Techniques
خصائص تيار-جهد لتفريغ البلازما المستمر المستخدم في تقنيات الترذيذ

Authors: Mohammed K. Khalaf --- Oday A. Hammadi --- Firas J. Kadhim
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 3 Pages: 11-16
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, the current-voltage characteristics of dc plasma discharges were studied. The current-voltage characteristics of argon gas discharge at different inter-electrode distances and working pressure of 0.7mbar without magnetrons were introduced. Then the variation of discharge current with inter-electrode distance at certain discharge voltages without using magnetron was determined. The current-voltage characteristics of discharge plasma at inter-electrode distance of 4cm without magnetron, with only one magnetron and with dual magnetrons were also determined. The variation of discharge current with inter-electrode distance at certain discharge voltage (400V) for the cases without magnetron, using one magnetron and dual magnetrons were studied. Finally, the discharge current-voltage characteristics for different argon/nitrogen mixtures at total gas pressure of 0.7mbar and inter-electrode distance of 4cm were presented.


Article
Analysis of Boltzmann Equation for SF6 and Some Gas-Mixture Discharges at Critical Field Condition

Authors: Abdulrida S. Hasaani --- Mukhlis M. Ismail
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 1 Pages: 31-34
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

The energy electron distribution function at a particular reduced electric field E/p (where E is the electric field and p is the gas pressure) for SF6+He and SF6+Ar mixtures has been studied. The distribution function has been calculated as a function of percentage mixture ratio (k) ranging from zero (pure SF6) to 100% (for He or Ar) at (E/p)crt. On the other stage, these distribution functions are also studied as a function of (k) at a particular (E/p)crt. under which the breakdown occurs for the same gas mixtures. The (E/p)crt calculation is adopted to explain the discrepancy of the distribution function for gas mixtures. It is also found that the distribution function for gas mixtures at (E/p)crt. and for any value of (k) are identical.


Article
Silver Nanoparticles Prepared by Electrical Arc Discharge Method in DIW

Author: Halah H. Rashed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 2 Part (B) Scientific Pages: 295-301
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, Silvernanoparticles prepared by arc discharge method in deionized water byapplying stablized direct current between two silver rods which are submerged in deionized waterat room temperature without any heat exchanger,vacuum equipment and gas handling equipment. During electrical discharge the temperature between electrodes can reach several thousand Celsius degrees. This leads to etch of silver electrodes in deionized water, silver vapor condensed in water creats a stable silver aqueous suspension. The silver nanoparticles were characterized by UV-Visiblephotometer, X-Ray Diffraction (XRD), and Atomic Force MicroscopeAFM. The optical absorption measurement showsthat the spectrum exhibits a Plasmon absorption band at ~ 400 nm which is the characteristic of silver nanoparticles.X-Ray Diffraction of the resulting NPs indicated that the particles had a crystalline structureand the average particle size determined from AFM, is about 78.75 nm.


Article
Langmuir Probe Diagnostics of Low-Pressure Glow Discharge Plasma Using Argon-Nitrogen Mixtures
التشخيص باستخدام مجس لانجمور لبلازما التفريغ ذي الضغط الواطئ باستخدام خلائط غازي الاركون والنتروجين

Authors: Bahaa T. Chiad --- Oday A. Hammadi --- Firas J. Kadhim --- Mohammed K. Khalaf
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 3 Pages: 17-26
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, experimental results on Langmuir probe diagnostics of low-pressure glow discharge plasma using argon-nitrogen mixtures are presented. The effect of variation in working pressure on the current-voltage characteristics of Langmuir probe diagnostics in unmagnetized glow-discharge plasma was introduced. The current-voltage characteristics of Langmuir probe diagnostics in glow-discharge plasma were studied at working pressure of 0.7mbar and three different cases (no magnetron, using one magnetron at the cathode, and using dual magnetrons). Similarly, the current-voltage characteristics of Langmuir probe in glow-discharge plasma at three different positions of the Langmuir probe inside plasma volume were presented. The variation of electron temperature and density in plasma with working gas pressure at the center point between the electrodes when dual magnetrons were used was determined. As well, the effect of mixing nitrogen with argon on the Langmuir probe characteristics at total working pressure of 0.7mbar and inter-electrode distance of 4cm was studied.


Article
Magnetic Field Distribution of Closed-Field Unbalanced Dual Magnetrons Employed in Plasma Sputtering Systems
توزيع المجال المغناطيسي لمجمع الماكنترون المزدوج غير المستقر ذي المجال المغلق والمستخدم في منظومات الترذيذ بالبلازما

Authors: Wisam A. Altun --- Mohammed A. Saleh --- Waleed N. Raja --- Oday A. Hammadi
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 3 Pages: 35-42
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this work, the spatial distribution of the magnetic field between two magnetrons in a closed-field unbalanced dual magnetron system was studied. The magnetic field was measured as a function of the position along the circumference of the circular surface of one magnetron. As well, the variation of magnetic field intensity along the vertical distance separating the two magnetrons was determined. A strategy was proposed for the measurement of the variation of magnetic field intensity at 4 cm away from the electrode surface along four axes. The spatial distribution of the magnetic field intensity over the magnetron surface at 4cm was determined and analyzed.


Article
Employment of Magnetron to Enhance Langmuir Probe Characteristics of Argon Glow Discharge Plasma in Sputtering System

Authors: Oday A. Hammadi --- Waleed N. Raja --- Mohammed A. Saleh --- Wisam A. Altun
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2016 Volume: 12 Issue: 4 Pages: 19-28
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

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Abstract

In this study, the parameters affecting the Langmuir characteristics of a closed-field unbalanced magnetron plasma sputtering system were studied. These parameters include the effect of variation in working pressure on the current-voltage characteristics of Langmuir probe diagnostics in unmagnetized glow-discharge plasma. Also, the current-voltage characteristics of Langmuir probe diagnostics in glow-discharge plasma at working pressure of 0.7mbar and three different cases (no magnetron, using one magnetron at the cathode, and using dual magnetrons) were introduced. The current-voltage characteristics of Langmuir probe in glow-discharge plasma at three different positions of the Langmuir probe inside plasma volume were determined. The variation of electron temperature and density in plasma with working gas pressure was determined at the center point between the electrodes when dual magnetrons were used. Finally, the effect of mixing nitrogen with argon on the Langmuir probe characteristics at total working pressure of 0.7mbar and inter-electrode distance of 4cm was introduced.


Article
Temperature Effect on the Effective Secondary Emission Coefficient for He and Ne Gases
ﺛﺆﻤﻟا يﻮﻧﺎﺜﻟا ثﺎﻌﺒﻧﻻا ﻞﻣﺎﻋ ﻰﻠﻋ ةراﺮﺤﻟا ﺔﺟرد ﺮﯿﺛﺄﺗ نﻮﯿﻨﻟاو مﻮﯿﻠﯿﮭﻟا يزﺎﻐﻟ

Author: Salman Hamza Hussein ﻦﯿﺴﺣ ةﺰﻤﺣ نﺎﻤﻠﺳ
Journal: journal of al-qadisiyah for pure science(quarterly) مجلة القادسية للعلوم الصرفة (فصلية). ISSN: 19972490 Year: 2016 Volume: 1 Issue: 21 Pages: 77-89
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

The relation between the effective secondary emission coefficient (ESEC)  andtemperature has been studied for He and Ne atoms. So we are studied the variation of withreduced electric field to the gas pressureE p between electrodes at different temperature (T ) for each gas.It has beenfound that the ESEC increase with ( E p ) at constant (T ) anddecreases with temperature at constant ( E ).

م دراسة العلاقة بین عامل الانبعاث الثانوي المؤثر  ودرجة الحرارة لغازي الھیلیوم والنیون. كذلك تم دراسة تغیر  مع النسبة بین الجھد المسلط بین قطبین وضغط الغاز p E عند درجات حرارة مختلفة لكل غاز. وجد بان عامل الانبعاث الثانوي المؤثریزداد مع النسبة p E عند ثبوت درجة الحرارة T ویتناقص مع زیادة درجة الحرارة عند ثبوت المجال الكھربائي المسلط ().ﻦﯿﺒﻄﻘﻟا ﻦﯿﺑ


Article
Evaluation of the Hydraulic Performance Indicators for Al- Ibrahim Irrigation Canal in the South of Iraq
تحليل مؤشرات الأداء لقناة شط آل أبراهيم الأروائية جنوب العراق

Authors: Jaafar S. Maatooq --- Ghazwan A. Kadhim
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 3 Part (A) Engineering Pages: 623-635
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

This study was concerned for steady flow in open canals of different flow conditions that may exist in irrigation system. To achieve this objective, AL-Ibrahim Canal Located South of Iraq has been selected from numerous irrigation systems having deficiencies between demand requirements and actual supply, due to a problematic of distribution and management. The field works consists the measurements of stages at outlets,at upstream, and at downstream head regulators .The study adopted nineteen actual cases of discharge along six months, two or more measurements at each month during the study period,between November 2013 to April 2014.The main objectives of the present study are; analysis the actual operation of irrigation canal and evaluated indicators then the HEC-RAS model was applied to achieve these objectives. Themax. stage and discharges measurements at head regulator during the study period was4.415 m3/sec at Jan.2014,where it less than a target discharge , so the outlets along canal should not be operated at the same time especially if the gate of the outlets are fully opened , because for entire operation numerous outlets will take discharge higher than the target.The study has shown that it doesn'toperatethe channel and access to the standard of performance but several scenarios have been prepared depending on the discharge at head regulator.

تهتم هذه الدراسة بالجريان الثابت في القنوات المفتوحة وحسب الشروط المختلفة للجريان في منظومات الري.ولتحقيق هذا الهدف تم اختيار قناة ري ال إبراهيم في جنوب العراق من بين العديد من منظومات الري والتي تعاني عجزا في متطلبات الري مقارنة مع المجهز الفعلي وذلك بسبب مشاكل التوزيع والإدارة للمياه. تمت الأعمال الحقلية بأجراء تسعة عشر حالة قياس فعلية لمناسيب المياه والتصريف في ناظم الصدر والمنافذ الحقلية وعلى مدار ستة أشهر ولمواسم زراعية مختلفة للفترة من شهر تشرين الثاني لعام 2013 ولغاية شهر نيسان من العام 2014 وبمعدل حالتين أو أكثر لكل شهر.الأهداف الرئيسية لهذه الدراسة هي تحليل التشغيل الفعلي للقناة وتقييم مؤشرات الأداء وتطبيق نموذج هيدروليكي باستخدام برنامج (HEC-RAS).وبينت الدراسة أن أعلى تصريف مسجل لناظم الصدر خلال فترة الدراسة كان بمقدار 4.415 م3/ثانية في شهر كانون الثاني من العام 2014. وهو اقل من التصريف المطلوب، لذلك فان المنافذ الحقلية الموزعة على طول القناة لايمكن تشغيلها في وقت واحد إذا كانت بواباتها مفتوحة بالكامل لان بعض المنافذ الحقلية سوف تأخذ تصريف أكثر مما هو مطلوب .بينت الدراسة انه لايمكن تشغيل القناة والوصول إلى الموشرات القياسية للأداءألامن خلال سيناريوهات محددة تم إعدادها اعتمادا على التصريف عند ناظم الصدر.


Article
Experimental Study of Heat Transfer Parameters of Impingement Heating System Represented by Conductive Target Plate of Resistive film

Authors: Assim H. Yousif --- Amer M. Al Dabagh --- Salah H. Abid Aun
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 8 Part (A) Engineering Pages: 1588-1604
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The current experimental study focuses on the heat transfer characteristics and pressure losses for impingement systemwhich is used in cooling the liner of gas turbine combustor. Recent experiment method of conductive heat transfer technique with resistive film in the back side target plate is introduced. The present experimental model measured both the heat transfer coefficient for inner target surface and the wall cooling effectiveness for outer target surface. To physically explain the phenomena associated with interaction flow area, a computational fluid dynamic code (Fluent 14) is employed. The continuity, momentum and energy equations arecomputationally solved to analyze the flow field in the jet impingement area. The tests models of the impingement plate are made from round jet holes of inline and staggered arrays arrangement with jet to jet spacing of four-hole diameter. Jet Reynolds numbers of 4200 to 15000 and jet height to diameter ratio of 1.5, 2.0, and 3.0 are maintained. The inline array, as expected enhanced the wall cooling effectiveness over that of the staggered array by10.3%andboth jet spacing and Reynolds number have an evident effect on the discharge coefficient. Empirical correlations are obtained for both arrays arrangement to predict the area-averaged Nusselt number as a function of jet governing parameters.


Article
Effect of Electrodes Separation in DC Plasma Sputtering on Morphology of Silver Coated Samples

Authors: Khalid A. Yahya --- Ban F. Rasheed
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2016 Volume: 19 Issue: 4 Pages: 78-85
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

In this work, the effect of the electrodes separation on plasma parameters and morphology properties for coated glass samples by silver metal using low voltage DC discharge plasma sputtering source. At fixed argon gas pressure 0.2 mbar and discharge currents Id(20,30,40,50 and 60)mA, for different electrodes separation d (3,4,4.5,5,6)cm was studied. The plasma sputtering source consists of a cylindrical chamber including two circular electrodes made from stainless steel. The cathode electrode is carrying the silver metal as a target and permanent magnet, while a glass sample coater is placed on the anode electrode. The plasma parameters: temperature of electron(Te) and ion density(ni) were determined by using cylindrical single Langmuir probe. Also, the surface morphology for the coater samples were studied by atomic force microscope (AFM). The results of this work shown that a linear increases in ions density and an exponential decreasing in electron temperature for different electrodes separation. Furthermore, the relationship between the average grain diameter and average grain height as a function of electrodes separation are nonlinear. The minimum average grain diameter is (90 nm) at d=4 cm for Id=40 mA and minimum average grain height is (5.5 nm) at the same electrodes separation and discharge current. When the temperature of electron increased, the values of average grain diameter increased while the values of average grain height decreased.

تم في هذا العمل, د ا رسة تأثير المسافة بين القطبين علىمعلمات البلازما وخصائص اشكال سطح النموذج المطليبالفضة باستعمال مصدر للترذيذ البلازمي للتفريغ عندالفولتيات الواطئة المستمرة في الترذيذ البلازمي بضغط غازالاركون الثابت ) 0.2 ( ملي بار لتيا ا رت التفريغ( 20,30,40,50,60 ( ملي امبير لعدة مسافات بين القطبين( 3,4,4.5,5,6 ( سم.يتكون مصدر الترذيذ البلازمي من حجرة اسطوانية تحتويعلى قطبين دائرين مصنوعين من مادة الستنلس ستيل. قطبالكاثود يحمل مادة الهدف والمغناطيس الثابت بينما يوضعالنموذج الزجاجي لطلائه على قطب الانود.عوامل البلازما, درجة ح ا ررة الالكترون وكثافة الايونات تمتحديد باستعمال مجس لانكمور الاسطواني المنفرد وايضادرست خصائص اشكال سطوح النماذج المطلية بواسطةمجهر القوة الذرية.أوضحت نتائج هذا البحث زيادة خطية في كثافة الايوناتونقصان بدالة أسية في درجة ح ا ررة الالكترون بزيادة المسافةبين القطبين. كما ان العلاقة بين معدل قطر الحبيبةوارتفاعها كدالة غير خطية للمسافة بين القطبين. اقل معدلقطر الحبيبة وارتفاعها هو ) 90 ( نانومتر عند المسافة (4) سموبتيار تفريغ ) 40 ( ملي امبير, واقل معدل ارتفاع الحبيبة هو( (5.5 نانومتر بنفس المسافة بين القطبين وتيار التفريغ.عند زيادة درجة ح ا ررة الالكترون فان قيم معدل قطرالحبيبة يزداد ويقل ارتفاعها.

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