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Article

Author: Dr. Haroun A.K. Shahad Dr. Samir M. Abdul Haleem
Journal: Iraqi journal of mechanical and material engineering المجلة العراقية للهندسة الميكانيكية وهندسة المواد ISSN: 20761819 Year: 2009 Volume: C Issue: first conf./ eng. coll. Pages: 465-483
Publisher: Babylon University جامعة بابل

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Abstract

The internal combustion engines are generally a major source of air pollution.However the spark ignition engines are recognized by their carbon monoxide andunburned hydrocarbon emission. One of the methods used to reduce the emission ofthese pollutants is the blending of hydrogen with the gasoline fuel, either on a massbasis or on energy replacement basis. The present research study is devoted to concernwith developing a numerical model to predict the effect of hydrogen blending (based on energy replacement) on the emitted concentrate of carbon and nitrogen oxides and the temporal and local variation of cylinder temperature. It is found that hydrogen blending improves combustion process by increasingthe flame propagation speed and hence increasing maximum cylinder temperature. Thetiming of maximum cylinder temperature is also advanced due to hydrogen blending. It is also found that the hydrogen blending reduces CO and CO concentrationsand increases NO concentrations. It is found that when the hydrogen blending ratioexceeds 20% the engine performance is deteriorated. x2


Article
Kinetics and Mechanism of Hydrogen Sorption in Yttrium-Silicon D88- Structure Phases, Part I

Authors: Jabbar S.Hadi --- Tahseen A. Alsalim --- M. Y. Shareef --- I. J. McColm --- et al.
Journal: Iraqi National Journal Of Chemistry المجلة العراقية الوطنية لعلوم الكيمياء ISSN: 22236686 Year: 2009 Issue: 36 Pages: 667-679
Publisher: Babylon University جامعة بابل

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Abstract

AbstractA relationship between the size of the z-axis lattice parameter and the rate of hydrogenation of D88 phases has been established. Materials with c-axis in the range 0.632-0.642 nm are most resistant to hydrogen content increase whilst maintaining a fast sorption capability for 0.9-10 H (fu)-1. From this Y5Si2Ge and Y5Si2GeN0.1 have been prepared and used to establish the hydrogen sorption kinetics at a range of temperatures and pressures of hydrogen. The effect that nitrogen has on the alloy is to increase reaction rates by a factor of approximately 3. Thermogravimetric plots were first analysed by the J-M-A equation as used by Goudy (6). Arrhenius representation of the first and second order equations indicate a significant change in reaction mechanism at 740-745 K. Activation energies are in the range 84-166 kJ (mol)-1 depending on order and temperature.

الخلاصة تم في هذا البحث ايجاد علاقة بين معامل شبكية المحور –Z وسرعة هدرجة اطوار D88 . ان المواد التي تمتلك المحور -C ضمن المدى 0.632-0.642 نانوميتر هي الكثر مقاومة لزيادة محتوى الهيدروجين . وانطلاقا من ذلك تم تحضير كل من Y5Si2Ge و Y5Si2GeN0.1 واستخدمت لتحديد مركبات امدصاص الهيدروجين ضمن مدى من درجات الحرارة وضغوط الهيدروجين . لقد كان تاثير وجود النتروجين في السبيكة هو زيادة معدلات التفاعل بمعدل ثلاث مرات تقريبا . وقد تم تحليل البيانات الثرموكرافية بواسطة معادلة J – M – A المستخدمة من قبل Goudy .


Article
Kinetics and Mechanism of Hydrogen Sorption in Yttrium-Silicon D88- Structure Phases, Part II(Model for Predicting the Kinetics of Hydrogen Reactivity with Y5Si2Ge)

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Abstract

Abstract Due to the limitations of the J-M-A approach as used by Goudy et.al (1) and developed by Hassen et.al (part I of this research (7)), an analysis of fraction reacted against reduced time has been introduced and the shape of the experimental curves were compared to the theoretically predicted shapes for various rate controlling mechanisms. From this pictorial analysis three steps appear to be dominant in different temperature and pressure ranges; (i) nucleation of α-phase in a β-phase matrix or for absorption the reverse, (ii) bulk growth of α or β-phase which is the β to α phase change on desorption or α to β on absorption, (iii) hydrogen diffusion in the bulk with some hydrogen becoming trapped at less labile sites. This approach has given an independent confirmation of the processes involved in hydrogenation of the D88 structure special ceramic materials that has been inferred in several earlier papers (1-6) .

الخلاصة نتيجة القصور في طريقة J – H – M التي استخدمها Goudy وطورها حسن في الجزء الاول من هذا البحث حيث تم استخدام طريقة تتضمن تقدير الكسر مقابل الزمن المختزل وقد تمت مقارنة المنحنيات التجريبية مع الاشكال المستخدمة نظريا لمختلف ميكانيكيات التحكم بالسرعة وقد اظهرت ثلاث خطوات رئيسية في درجات حرارة وضغوط مختلفة .


Article
Study on Association Between o-methoxy-benzylidene-p-aminoaniline with phenols

Authors: A.S.P Azzouz عادل سعيد بيتر عزوز --- S.S Othman --- A.N. Al-Dabagh
Journal: Iraqi National Journal Of Chemistry المجلة العراقية الوطنية لعلوم الكيمياء ISSN: 22236686 Year: 2009 Issue: 36 Pages: 782-792
Publisher: Babylon University جامعة بابل

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Abstract

Abstract The interactions of o-methoxy-benzylidene-p-aminoaniline (MBAA) with phenol, p-methoxyphenol ,and p-chlorophenol in n-hexane are studied by using UV spectroscopy . The study led to the formation of hydrogen bond species of types O – H∙∙∙∙∙O and O – H ∙∙∙∙∙ N between MBAA with phenol and p-methoxyphenol . The last is appeared from the UV spectra record of MBAA with phenols stated at relative concentrations ratio of phenol / MBAA and p-methoxy phenol / MBAA of values 4/1 and 4/1 respectively. Similar result is obtained on using p-chlorophenol at relative concentration ratio of p-chlorophenol / MBAA of a value 4/1 , with additional appearance of two UV protonated bands at a wavelengths of 463 nm and 474 mm . them . The equilibrium constants for hydrogen bond formations of MBAA with phenols stated are included . The interactions of systems under study are confirmed by thermodynamic method . These show that and have a negative signs , as well as their values which support hydrogen bondings . Moreover , the processes of non spontaneous hydrogen bonding as observed and evident from the positive values of are included . These final abnormal results are unexpected and discussed in details .

الخلاصة يتضمن البحث دراسة تداخلات MBAA مع الفينول ، بارا ميثوكسي فينول وبارا كلورو فينول في مذيب الهكسان وبأستعمال مطيافية UV . اكدت الدراسة على تكوين اواصر هيدروجينية بنوعي O – H∙∙∙∙∙O و O – H ∙∙∙∙∙ Nبين MBAA مع الفينول ومشتقاته . الاواصر الهيدروجينة المذكورة تواً ظهرت من اطياف UV المسجلة للمركب MBAA وبنسب تراكيز 4/1 . بارا كلورو فينول اظهر نتائج متشابهة وعند نفس نسبة التركيز المذكورة مع ظهور حزمتي برتنة اضافية عند الاطوال الموجية nm 463 و nm 474 واللتان تعودان الى ايوني النتريليوم والاوكزونيوم . كما تضمن البحث تعيين ثوابت التوازن التداخلات المذكورة بين MBAAوالفينولات والمثبتة بالطريقة الثرموديناميكية . دللت الاخيرة على أن اشارات و هي سالبة بأضافة الى قيمها والمؤكدة للاواصر الهيدروجينية بين الجزيئات المتداخلة . اشتمل البحت على حساب والذي يؤكد ان التفاعل المذكور غير تلقائي . النتيجة الاخيرة كانت غير متوقعة ونوقشت بأسهاب .

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