research centers


Search results: Found 68

Listing 1 - 10 of 68 << page
of 7
>>
Sort by

Article
Kinetic and Equilibrium Studies on Removal of Nickel Ions onto Pomegranate Peel

Authors: Safanah A. Farhan --- Rasha M. Dadoosh --- Ayad T. Mahmood
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2013 Volume: 16 Issue: 4 Pages: 11-17
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

In this work, pomegrante peel (PGP) was investigated as adsorbent for removal of nickel ions from aqueous solution. It was found that maximum adsorption occur at PH7. Their equilibrium data were fitted with the Freundich and Langmuir isotherms. The adsorption kinetics data were best fitted with the pseudo–second order

في هذا البحث تم استخدام قشور الرمان كماده امتزاز لازاله ايونات النيكل (II) من محاليل المائيه، ولقد وجد ان أفضل امتزاز يحصل عندpH7) ). قيم التوازن الحراري تتفق مع معادلات فريندلش ولاينكماير، حيث ان دراسه حركيه الامتزاز تتفق مع مرتبه التفاعل الثانيه الكاذبه.


Article
Adsorption and Kinetic Study of Methylene Blue dye on New Surface Derived from Copolymer (Melamine – Formaldehyde – Para- methyl Anisole)
امتزاز ودراسة حركية لصبغة المثلين الزرقاء على سطح جديد مشتق من كوبوليمر(ميلامين – فورمالديهايد – بارا - مثيل انيزول)

Author: Waeel M. Hamud وائل محمد حمود
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2015 Volume: 12 Issue: 1 Pages: 178-187
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

A new copolymer (MFA) was prepared from condensation of melamine (M) with p- methyl – anisole (A) in the presence of condensation agent like 37% (w/v) of formaldehyde. The new copolymer was characterized by elemental, IR and HNMR spectra. The chelating ion-exchange property of this polymer was studied for methylene blue dye in aqueous solution in 100-200ppm concentrations. The adsorption study was carried out over a wide range of pH, shaking time and in media of various kinetic parameters models. Thermal parameters like enthalpy, entropy and Gibbs free energy of adsorption process of methylene blue on surface of MFA resin were determined on the basis of kinetic parameters at different temperatures. To describe the equilibrium of adsorption, the Langmuir, Freundlich and Temkin isotherms were used. The Langmuir isotherm correlation (R2=0.987) was the best fitted for experimental data with maximum adsorption capacity of 200 ppm. A higher correlation value of the kinetic's model was observed close to pseudo first order, second order and Temkin kinetic models values of correlation R2 lie in the range (0.983-0.987) in comparing to other kinetic models.

تم تحضير كوبوليمر جديد MFA)) من تكثيف بارا-ميثوكسي-تولوين والميلامين (( M بوجود الفورمالديهايد (F) في وسط عامل (حامض الهيدروكلوريك (2-Mوبنسبة مولية 2:1:3لمونمرات التفاعل. تم تشخيص الراتنج الجديد بالتحليل الدقيق للعناصر, اطياف الاشعة تحت الحمراء, واطياف الرنين النووي المغناطيسي للبروتون HNMR. اجريت دراسة التبادل الايوني المخلبي للراتنج لصبغة المثيلين الازرق ((MB في المحيط المائي في مدى من التراكيز 100-200 ppm)) كما اجريت دراسة الامتزاز في مدى من الدالة الحامضية , ووقت الرج واجراء عدة دراسات حركية . تم قياس العوامل الثرموديناميكية مثل الانثالبي , الانتروبي و طاقة كبس الحرة لامتزاز صبغة المثيلين الازرق من سطح الراتنج الجديد MFA بعدة درجات حرارية مختلفة . ولوصف الامتزاز عند الاتزان درست ايزوثيرمات لانكماير, فريندلج وتمكن ووجد ان معامل التصحيح R2=0.987 لايزوثيرم لانكماير ليعطي اقصى سعة للامتزاز عند تركيز مثالي ((200 ppm وتشير التصحيحات العالية R2 المدى 0.983-0.987)) بان خضوع عملية الامتزازالى المعادلات الحركية للدرجة الاولى والثانية الكاذبة وتمكن هي اثبات لتاثير عوامل اخرى مثل تركيز الهدرونيوم والدالة الحامضية PH وتاثير كمية الكوبوليمر(سطح) المستخدم في عملية الامتزاز الثرموديناميكي.


Article
Pyrolysis of High-density Polyethylene for the Production of Fuel-like Liquid Hydrocarbon

Authors: Sawsan D. A. Shubar --- Ammar S. Abbas عمار صالح عباس
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2008 Volume: 9 Issue: 1 Pages: 23-29
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Pyrolysis of high density polyethylene (HDPE) was carried out in a 750 cm3 stainless steel autoclave reactor, with temperature ranging from 470 to 495° C and reaction times up to 90 minute. The influence of the operating conditions on the component yields was studied. It was found that the optimum cracking condition for HDPE that maximized the oil yield to 70 wt. % was 480°C and 20 minutes. The results show that for higher cracking temperature, and longer reaction times there was higher production of gas and coke. Furthermore, higher temperature increases the aromatics and produce lighter oil with lower viscosity.


Article
Kinetics Decomposition of Some Substituted Benzendiazonium Salts in HCl Solution.

Loading...
Loading...
Abstract

AbstractThe decomposition rate, rat constant and decomposition activation energy of substituted benzendiazonium salts ( N+ ≡ NCl-) were calculated by folloing the quantity of nitrogen gas produced as a function of time at several temperatures ranging from (35 to 50)oC. The effect of the R group type on the rate of decomposition ,rat constant and activation energy, was studied. The effect of variation of R group position (o, p, m) has been studied as well.

AbstractThe decomposition rate, rat constant and decomposition activation energy of substituted benzendiazonium salts ( N+ ≡ NCl-) were calculated by folloing the quantity of nitrogen gas produced as a function of time at several temperatures ranging from (35 to 50)oC. The effect of the R group type on the rate of decomposition ,rat constant and activation energy, was studied. The effect of variation of R group position (o, p, m) has been studied as well.


Article
Comparison Study between Dubinin-red Ushkevich and Temkin Model for Adsorption of Mercury onto Activated Carbon

Author: Hayder Mohammed Abdul-Hameed
Journal: Journal of Engineering مجلة الهندسة ISSN: 17264073 25203339 Year: 2008 Volume: 14 Issue: 1 Pages: 2331-2336
Publisher: Baghdad University جامعة بغداد

Loading...
Loading...
Abstract

Activated carbon has been used as an adsorbent in this work to remove mercury from aqueous solutions. The aim of the work is to test how best activated carbon can be used as an adsorbent for mercury. Equilibrium isotherms, both, Dubinin-Redushkevich, and Temkin have been test. The batch experiments were conducted at room temperature (30oC) and at the normal pH (7.0±0.1) of the solution. HYBRID fraction error function analysis shows that the best-fit for the adsorption equilibrium data is represented by (D-R) model rather than Temkin model. Its found that the correction factor (R2) for (D-R) is 0.9928 while for Temkin model is 0.942, also the HYBRID fractional error was conducted for the both models and (D-R) model give minimum value of (0.0128) while it was (0.129) for Temkin.

يهدف البحث الى اجراء المقارنة لفاعلية موديلين رياضيين هما موديل Dubinin-Redushkevich وموديل Temkin لوصف عملية امتزاز الزئبق ضمن المحلول المائي باستخدام الكاربون المنشط . وقد تم اجراء التجارب المتقطعة في درجة حرارة 30ْ وقيمة (pH=7) وقد وجد ان معامل التصحيح (R2) للموديل الرياضي الاول يساوي (0.9928) بينما كانت القيمة للموديل الثاني تساوي (0.942) كذلك تم تطبيق معيار (HYBRID) الانحرافي للخطأ ووجد ان قيمته للموديل الاول يساوي (0.0128) بينما للموديل الثاني (0.129)


Article
A Deactivation Correlation for Platinum Y-Zeolite in n-Hexane Isomerization

Author: Haiyam Mohammed A. Al-Raheem
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2011 Volume: 29 Issue: 8 Pages: 1451-1462
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

The objective of the present work is to realize the kinetic modeling regardingdeactivation of Pt-HY zeolite and monitor the isomerization reaction of n-hexane. Thecatalyst has been prepared with o.4% Pt and evaluated during the isomerization reactionof n-hexane. Based on the results of catalytic investigation, a kinetic model was proposedto deactivate the catalyst by coke formation. The present method provides information onapparent overall kinetics as well as deactivation parameters and would seem to provide arapid method for screening of reaction/deactivation behavior. Accordingly thedeactivation order was found to be 3.72. The obtained correlation of deactivation predictsthe activity pattern under the applied reaction conditions, closely mimics those observedexperimentally, and spans those obtained from empirical correlations.


Article
KINETICS AND MECHANISM STUDIES OF OXIDATION OF Α-AMINO ACIDS BY N-BROMOSUCCINIMIDE

Authors: Hassan Hadi --- Ammar J. Mohammed
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2007 Volume: 10 Issue: 2 Pages: 66-72
Publisher: Al-Nahrain University جامعة النهرين

Loading...
Loading...
Abstract

Kinetics and mechanism studies of oxidation of some α-amino acids (Proline, Arginine, Alanine) (AA) by N-Bromosuccinimide (NBS) by using conductivity method was carried out. The kinetic study showed that the reaction was first order with respect to NBS and AA. The effect of addition of HClO4 to the reaction was negative on the rate of reaction. The reaction was carried out at different temperatures in which were calculated. The rate of reaction of AA was as follows: Proline > Arginine > Alanine

تـم دراسة حركيـة وميكانيكية أكسدة بعض الحوامض الفـا-امينية بواسطـة N-Bromosuccinimide بأستخدام التوصيلية. بينت الدراسة الحركية أن التفاعل من المرتبة الاولى لكل من الحوامض الفا-امينية وN-Bromosuccinimide . وجد أن إضافة حامض HClO4 ذات تأثير سلبي على سرعة التفاعل. تم دراسة التفاعل بدرجات حرارة مختلفة وتم حساب الدوال الثرموديناميكية للتفاعل. وجد أن سرعة تفاعل الأكسدة للحوامض الامينية كانت بالترتيب الآتي:Proline > Arginine > Alanine.


Article
Effect of Transformation Temperature on Microstructure andMechanical Properties of Bainite
دراسة تأثير درجة حرارة التحول على البنية المجهرية

Author: Hala Salman Hasan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2012 Volume: 30 Issue: 13 Pages: 2165-2174
Publisher: University of Technology الجامعة التكنولوجية

Loading...
Loading...
Abstract

Fully bainitic microstructure can be obtained by isothermal transformation attemperatures within the range of bainite transformation. Both transformation temperatureand time determine the phase fraction, the scale of the resultant microstructure and thecarbone content of the retained austenite, which in turn determine the mechanicalproperties.In this study, the thermomechanical simulator was used to obtained the fully bainiticmicrostructure for the high carbon alloy steel (0.78%C) at a different bainitetransformation temperatures (200 to 350°C) in order to study the effect of the isothermaltransformation temperature on the resultant mechanical properties.It has been concluded from the detailed analysis of the microstructure, the dilatometricdata and the mechanical properties (hardness and tensile properties) that finer bainite andless retained austenite phase fraction can be obtained by transformation at lowertemperatures, and that leads to exceptional mechanical properties (Hardness ≈ 660 HV,and Tensile strength ≈ 2 Gpa).

يمكن الحصول على بنية مجهرية من البينايت عن طريق التحولات الايزوثيرمية ضمن مدى درجاتحرارة التحولات الطورية الباينايتية، ان درجة حرارة وزمن التحول الطوري يحددان الكسر الحجميودرجة نعومة البنية الناتجة وكذلك المحتوى الكاربوني للاوستنايت المتبقي والذي بدوره يحدد الخواصالميكانيكية الناتجة.تم في هذا البحث استخدام جهاز محاكي للتحولات الحرارية الميكانيكة للوصول الى البنية الباينايتية0.78% ) بدرجات حرارة تحول ايزوثيرمي مختلفة تتراوح من 200 C) للصلب العالي الكربونالى 350 م° وذلك لدراسة تأثير درجة حرارة التحول على الخواص الميكانيكية الناتجة. لقد تم التوصل من خلال التحليل الدقيق للبنية المجهرية الناتجة وبيانات التغيير في الابعاد وكذلك نتائجفحوصات الصلادة ومقاومة الشد الى امكانية الحصول على بينايت ناعم جدا مع انخفاض درجات حرارة2 مقاومة Gpa ≈ التحول الايزوثيرمي مما يقود الى خواص ميكانيكية عالية ( 660 صلادة فيكرز وشد).


Article
Monte Carlo Simulation of Electronic Kinetics in Gas Discharge

Authors: A.B. Kadhem --- B.H. Hamad
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2005 Volume: 1 Issue: 3 Pages: 3-5
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

Loading...
Loading...
Abstract

The phenomenon of electrical gas discharge is present in manyapplications of plasma physics. Calculation of electrons motion tracingin gases are described. The backscattering probability of electrons tothe cathode has been estimated for values of E/P0 ratio from 10 to 200V.cm-1.torr-1 and for emission energies up to the lowest excitationpotential. The primary ionization coefficients and drift velocities wereevaluated for values of E/P0 ratio from 20 to 400 V.cm-1.torr-1. Theequilibrium of swarm with the field was considered in detail. It isshown that for uniform fields, deviations from exponential growth ofcurrent with increasing electrode separation occur if the interelectrodevoltage is not at least three times the mean energy ofelectrons impinging on the anode.


Article
Investigation of Amorphous to Crystalline Transition in Glassy Se80Te20 and Se70Te20M10 (M = Ag, Cd, Sb) Alloys

Authors: N. Mehta --- A. Kumar
Journal: Iraqi Journal of Applied Physics المجلة العراقية للفيزياء التطبيقية ISSN: 18132065 23091673 Year: 2005 Volume: 1 Issue: 3 Pages: 7-13
Publisher: iraqi society for alternative and renewable energy sources and techniques الجمعية العراقية لمصادر وتقنيات الطاقة البديلة والمستجدة

Loading...
Loading...
Abstract

Calorimetric measurements have been performed in binary Se80Te20 and ternary Se70Te20M10 (M=Ag, Cd, Sb) alloys to study the effect of metallic additives (Ag, Cd, Sb) on the crystallization kinetics in Se80Te20 alloy. Three different non-isothermal methods Kissinger’s method, Matusita-Sakka theory and Augis-Bennett approximation method have been used in the present study. Different kinetic parameters such as the activation energy of crystallization (EC), the order parameter(n), the growth morphology parameter (m), the rate constant (K) and its frequency factor (Ko) have been determined. The effect of third element on crystallization temperature of binary Se80Te20 is explained in terms of Arrhenius dependence of rate constant K(T). The increasing sequence of activation energy of crystallization in ternary Se70Te20M10 (M=Ag, Cd, Sb) alloys is explained in terms of their average bond strength.

Listing 1 - 10 of 68 << page
of 7
>>
Sort by
Narrow your search

Resource type

article (68)


Language

English (68)


Year
From To Submit

2019 (4)

2018 (13)

2017 (6)

2016 (10)

2015 (11)

More...