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Article
Growth and Characterization of CdTe Nanorods Flower-like shape
تنمية و تشخيص القضبان النانومترية للكادميوم تيلوريد بشكل زهرة

Authors: Fatima A. Hassan فاطمة عامر حسن --- Asama N. Naje اسامة ناطق ناجي --- Rawa K. Ibrahim روى خليل أبراهيم
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2016 Volume: 57 Issue: 2B Pages: 1198-1202
Publisher: Baghdad University جامعة بغداد

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Abstract

CdTe nanorods were prepared by using aqueous chemical synthesis. The influences of reaction time (1-3 hours) on the optical and structural properties were studied. The UV-visible absorption spectrum reflects a wide absorption range in the visible spectrum. The energy gap calculations show decrease in the energy gap with increasing reaction time. The SEM images show that the CdTe appears as flower of nanorods-like.

تم تحضير قضبان الكادميوم تيلوريد النانومترية باستخدام التقنية الكيميائية المائية. تمت دراسة تأثير زمن التفاعل (1-3 ساعات) على الخصائص البصرية و التركيبية. طيف الامتصاص الفوق بنفسجي-المرئي عكس امتصاص واسع ضمن مدى الطيف المرئي. حسابات فجوة الطاقة اظهرت نقصان في فجوة الطاقة بزيادة زمن التفاعل. صور المجهر الألكتروني الماسح اظهرت ان شكل الكادميوم تيلوريد هو زهرة من القضبان النانومترية.


Article
Perovskite Thin Film Preparation and Energy Band-Gap Determination for Solar Cell Applicatiosn

Authors: Thaira Z. Altayyar --- Shubhra Gangopadhyay
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 14 Part (A) Engineering Pages: 2611-2620
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Using Perovskite is a promising approach for upgrading the performance of an established low-bandgap Si photo voltaic (PV) solar technology because Perovskite is a high bandgap polycrystalline semiconductor compared with bulk Si and other semiconductors such as GaAs. In this work, Perovskite-structured methyl ammonium lead triiodide CH3NH3PbI3 uniform one-step planar thin films nanoparticles (NPs) have been developed from the reaction process of methylammonium iodide with PbI2 and deposited on a glass substrate by Aerosol Assisted Chemical Vapor Deposition (AACVD) to minimize the size of the solar cell and to reduce the cost and increase efficiency. This aims at the study and investigation of the energy bandgap (Eg) of nano-architectured solar cells absorber film as light harvesters. The X-ray diffraction (XRD) patterns of a CH3NH3PbI3 film on glass substrates are recorded by X' Pert Ultima IV X-ray diffractometer. Optical band gap of CH3NH3PbI3 is estimated by UV−Vis absorption spectroscopy and extracted from the absorption spectrum of the Tauc plot to be 1.63 eV. The Perovskite deposited on glass appears efficient to absorb most of the light with wavelength below 800 nm with a refractive index (n): 2.75. The film thickness was measured by an optical profile-meter to be about 200 nm, giving small reflectivity of 0.23 and resulting in efficiency enhancement of 15.7 %.


Article
Dynamic Analysis of Absorption Column
التحليل الديناميكي لعمود الامتصاص

Author: Maryam Yousif Ghadhban
Journal: Thi-Qar University Journal for Engineering Sciences مجلة جامعة ذي قار للعلوم الهندسية ISSN: 20759746 Year: 2016 Volume: 7 Issue: 2 Pages: 104-119
Publisher: Thi-Qar University جامعة ذي قار

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Abstract

The absorption column is one of the essential separation processes in industrialoperation, so the need arises to control absorption column by process simulation and also toanalyze system by method called frequency response using MATLAB8. This work dealt withgas-liquid (air-water) absorption packed column which is analyzed by bode plot and frequencyresponse to determine the stability of the system with or without Proportional Controller (P),Proportional Integral Controller (PI) or Proportional Integral Derivatives Controller (PID).Thefrequency response gives the transient response information, by defining such frequencyresponse quantities as gain margin and phase margin. This work presents dynamic analysis ofabsorption column which is single input/single output (SISO) using feedback control (P, PI andPID) with the parameters of Cohen-Coon, Ziegler Nichols and Internal Model control andcompares between them.

عمود الامتصاص هو واحد من عمليات الفصل الاساسية فى الصناعات البتروكيمياوية ،لذلك دعت الحاجة للسيطرةعلى عمود الامتصاص بواسطة عملية المحاكاة وايضا عن طريق تحليل النظام بطريقة تدعى استجابة التردد باستخدام برنامجتم في هذا العمل إستخدام عمود الإمتصاص المحشو ذو نظام غاز-سائل )ماء – هواء( الذي حلل بواسطة .MATLAB8وإستجابة التردد لحساب إستقرارية النظام مع او بدون السيطرة. إستجابة التردد تعطى معلومة الاستجابة )Bode( طريقة الهذا العمل يقدم التحليل .Phase Margin And Gain Margin العابرة بواسطة تعريف بعض كميات استجابة التردد مثل(P,PI, باستخدام سيطرة التغذية الارجاعية (SISO) الديناميكى لعمود الامتصاص والذى هو احادى المدخل احادى المخرجوالمقارنة بينهم. (Ziegler - Nichols, Cohen - Coon And Internal Model Control) مع معاملات and PID)

Keywords

absorption --- control --- gas --- liquid --- column


Article
Heavy Metals Content in Some Chips Products in Iraqi Markets
مــــــــــــــــحتوى المعــــــــــادن الثقيــــــــــلة فـــــي بعض منتـــــجات الجبس فـــــي الاســــــــواق العــــــــــراقية

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Abstract

The recent study was conducted to measure some heavy metal content in potato and corn chips in Baghdad markets. Samples were analyzed by Atomic Absorption Spectrophotometer (AAS). Four metals, Cobalt (Co), Cadmium (Cd), Cupper (Cu) and Lead (Pb) were determined. Two types belonging to two manufacturer resources and two trademarks for each resource were tested in this work. Generally, the study recorded that the potato chips were containing metals less than the corn chips. According to Iraqi criteria, all tested types of potato chips were under the allowed levels. The mean of accumulation trend for both types was: Cu>Co>Pb>Cd. The mean of accumulation trend for the corn types of chips was: Baz>Pufack> Fantasia > Snack. The mean of accumulation trend for Potato chips was: Hlla>Mrsticks>Shepisco>Leez. Only Pufack (Jordan) Baz and Fantasia (Iraq) trademarks were containing levels of Cu exceeded of criteria. The aim of study is to monitor the levels of metals in chips food.

أجريت الدراسة الحالية لقياس محتوى بعض المعادن الثقيلة في رقائق البطاطس والذرة في أسواق بغداد. وتم تحليل العينات بجهاز مطياف الامتصاص الذري (AAS). وقد حددت أربع معادن هي الكوبالت (Co)، الكادميوم (Cd) والنحاس (Cu) والرصاص (Pb) . تم اختبار نوعين ينتميان إلى مصدرين تصنيعيين وتم اختبار علامتان تجاريتان لكل مصدر في هذا العمل. سجلت الدراسة عموما أن رقائق البطاطس تحتوي على معادن أقل من رقائق الذرة. وفقا للمعايير العراقية، كانت جميع الأنواع المختبرة من رقائق البطاطس تحت المستويات المسموح بها. وكان متوسط الترتيب التراكمي لكلا النوعين كالتالي: Cu > Co > Pb >Cd. كان متوسط الترتيب التراكمي لأنواع رقائق الذرة: Baz > Pufack > Fantasia > Snack. وكان متوسط الترتيب التراكمي لرقائق البطاطس في كالتالي: Hlla > Mrsticks > Shepisco > Leez. كانت العلامات التجارية Pufack (الأردن) Baz وFantasia (العراق) فقط تحتوي على مستويات من Cu تجاوزت المعايير. الهدف من الدراسة هو رصد مستويات المعادن في رقائق الغذاء.


Article
Effect of Solvents on the Photophysical Properties of the Polystyrene Solutions

Authors: Esam A. Tawfi --- Mohammed M. Rasheed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 5 Part (B) Scientific Pages: 691-696
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

The aim of this work was to investigate the photophysical behavior of polystyrene solutions under the effect of different solvents at different concentrations .Testband at 262 nm. There was no effect of solvents and concentration on the position of the maximum absorption wavelength. The data show that a strong dependence between absorbance intensity and concentration. Polystyrene in chloroform, cyclohexane and dichloromethane showed fluorescence monomer emission at 296nm. Excimer emissions were recorded for polystyrene in chloroform, cyclohexane, dichloromethane and tetrahydrofuran at 307nm, 325nm, 327nm and 330nm respectively. Solvents have effect on the fluorescence quantum yield magnitude, where highest value of it had been recorded in cyclohexane (55%)


Article
Dopant Effect on The Nonlinear Optical Properties of TiO2- PMMA Nano Composites for Optical Limiter Applications

Authors: Aya H. Makki --- Ali H. AL-Hamadani --- Mohammed Abdulridha Husien
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 5 Part (A) Engineering Pages: 1012-1016
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this paper theeffect of ZnO dopant on the nonlinearoptical behavior of TiO2-PMMA Nano composites films was studied. TiO2-PMMA Nano composites films were prepared using solution casting method then doped with different amounts of ZnO nanoparticles. Z-Scan measurements were performed to obtain the nonlinear optical response of these samples at 1064nm using CW Nd-YAG laser. The addition of ZnO nanoparticle into the Nano composites showed a great enhancement in the nonlinear optical response and decreasing in limiting threshold (10 mW)as the dopants concentration increased.


Article
Effect of Nano Powder on Mechanical and Physical Properties of Glass Fiber Reinforced Epoxy Composite
تأثير المساحيق النانويه على الخواص الميكانيكية والفيزيائية للمواد المركبة المدعمة بالالياف الزجاج

Authors: Tamara Raad Kadhim تماره رعد --- Fadhel Abbas Hashim فاضل عباس هاشم --- Aseel Basim Abdul-Hussein اسيل باسم عبد الحسين
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2016 Volume: 12 Issue: 3 Pages: 72-79
Publisher: Baghdad University جامعة بغداد

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Abstract

Fiber reinforced polymer composite is an important material for structural application. The diversified application of FRP composite has taken center of attraction for interdisciplinary research. However, improvements on mechanical properties of this class of materials are still under research for different applications. In this paper we have modified the epoxy matrix by Al2O3, SiO2 and TiO2 nano particles in glass fiber/epoxy composite to improve the mechanical and physical properties. The composites are fabricated by hand lay-up method. It is observed that mechanical properties like flexural strength, hardness are more in case of SiO2 modified epoxy composite compare to other nano modifiers, were physical properties like density, water absorption are more in case of TiO2 modified epoxy composite. This may be because of smaller particle size of silica compare to others.

تم في هذا البحث تحضير مواد متراكبه بواسطة طريقة القولبة اليدوية ودراسة خصائصها. تتكون المواد المتراكبة من راتنج الايبوكسي كماده اساس و3% كسر حجمي من ألياف الزجاج كمادة تقوية و 2% و4% و 6% لمساحيق نانويه ( اوكسيد الالمنيوم Al2O3, اوكسيد السليكون SiO2 , اوكسيد التيتانيوم TiO2 ). فحص الصلاده ومقاومة الانحناء والكثافه والامتصاصيه للكشف عن قيمها لكل نوع من المواد المتراكبة النانويه. اظهرت النتائج ان الايبوكسي غير المقوى يمتلك خواص اقل من المواد المتراكبة . عند اجراء اختبارات الكثافة فان النتائج اظهرت بان الكثافة تزاد مع زياد الكسر الحجمي وامتصاصية الماء والصلادة ومقاومة الانحناء بانها تزداد مع زيادة الكسر الحجمي مع اصغر حجم حبيبي .


Article
Effect of Micro Powder on Mechanical and Physical Properties of Glass Fiber Reinforced Epoxy Composite

Authors: Aseel Basim Abdul-Hussein --- Fadhel Abbas Hashim --- Tamara Raad Kadhim
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2016 Volume: 34 Issue: 7 Part (A) Engineering Pages: 1402-1414
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In the present study, composites were prepared by Hand lay-up molding. The composites constituents were epoxy resin as the matrix, 3% volume fractions of Glass Fibers (G.F) as re enforcement and 2%, 4%, 6% volume fraction of micro powder (Aluminum Oxide Al2O3, Silicon Oxide SiO2 and Titanium Oxide TiO2) as filler. Studied the, hardness test, flexural strength, density, water absorption measurements and tests were conducted to reveal their values for each type of composite material. The results showed that the non – reinforced epoxy have lower properties than nano composites material. Measured density results had show an incremental increase with volume fraction increase and water absorption, hardness, and flexural strength had show an incremental increase with volume fraction increase and with smaller particle size.


Article
Non Linear Optical Properties of Silver Nanoparticles
الصفات البصرية اللاخطية لجسيمات الفضة النانوية

Author: Zainab Sabeeh Sadeq زينب صبيح صادق
Journal: Iraqi Journal of Science المجلة العراقية للعلوم ISSN: 00672904/23121637 Year: 2016 Volume: 57 Issue: 3C Pages: 2240-2244
Publisher: Baghdad University جامعة بغداد

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Abstract

In the present work, a Z-scan technique was used to study the nonlinear optical properties, represented by the nonlinear refractive index and nonlinear absorption coefficients of the Ag nanoparticles. In this technique, a pulsed second harmonic Nd :YAG laser at wavelength 532 nm was used. The results show that the nonlinear refractive index and nonlinear absorption coefficients of the Ag nanoparticles are found to be dependent on the size these nanoparticles.

في العمل الحالي، استخدمت تقنيه المسح على المحور الثالث لدراسة الخصائص الغير خطية ، والتي تمثل معامل الانكسار اللاخطي ومعامل الامتصاص اللاخطي لجسيمات الفضة النانوية. في هذه التقنية استخدم ليزر النديميوم ياك النبضي عند الطول الموجي 532 نانومتر. اظهرت النتائج ان معامل الانكسار اللاخطي ومعامل الامتصاص اللاخطي لجسيمات الفضة النانوية يعتمد على حجم هذه الجزيئات النانوية.


Article
Theoretical Calculations of the Seasonal and Solar Activity Variations for Ionospheric Collision Frequency and Debye Length over Baghdad City

Author: Ali Hussein Ni'ma
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2016 Volume: 27 Issue: 4 Pages: 88-94
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

In this study, two important ionospheric factors have been calculated, the collision frequency of electron and Deby length for a height range from 80 Km to a height approaching the maximum height of the F2 region of the ionosphere above the Earth's surface. Both above factors have been calculated for two different levels of solar activity and for two seasons (winter and summer). Also, six months were adopted for every level of solar activity and season. The estimation of collision frequency of electron is depends on the contribution of neutral constituents and ions. Three neutral atmospheric gases have been adopted to calculate the collision frequency, Molecular and atomic oxygen O2 and O respectively and molecular nitrogen N2, as well as the singly charged ions were taken into account in calculation

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