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Article
Synthesis and Spectroscopic Studies of Metal Complexes with Schiff Bases Derived from 2-[5-(Pyridin-2-Ylmethylene)-Amino] 1,3,4-Thiadiazol-2-Yl-Phenol

Authors: Ali A. Ali --- Dina Adil --- Evon Akram --- Naser Shaalan
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2018 Volume: 00 Issue: 1 Pages: 37-42
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

Herein, we show the preparation and the characterization of new metal complexes by using a Schiff base ligand 2-[5-(Pyridin-2-ylmethylene)-amino] 1,3,4-thiadiazol-2-yl-phenol (L) with the metals Co(II), Ni(II), Cu(II) and Zn(II). This Schiff base ligand was synthesized via condensing [2-pyridine carboxaldehyde] with [2-amino-5-phenyl-1,3,4-thiadiazol] in an alcoholic solution. For preparing complexes, two tetradentate Schiff bases ligand were employed with two metal ions of Co2+, Ni2+, Cu2+ and Zn2+ as dinuclear formula M2L2. The synthesized ligand and its metal complexes were well characterized using FTIR, UV-Vis absorption, elemental analysis, thermal analysis, 1H-NMR, and mass spectroscopy. Based on these characterizations, the chemical structures of the ligand and the metal complexes were confirmed. Furthermore, the electronic and magnetic properties of the prepared metal complexes were clearly understood.


Article
Studying the Factors Affecting the Drag Coefficient in Non-Newtonian Fluids

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Abstract

The aim of this research is to study the factors affecting drag coefficient (C ) in non-Newtonian fluids which are the rheological properties ,concentrations of non-Newtonian fluids, particle shape, size and the density difference between particle and fluid .Also this study shows drag coefficient (C ) and particle Reynolds' number (Re ) relationship and the effect of rheological properties on this relationship. An experimental apparatus was designed and built, which consists of Perspex pipe of length of 160 cm. and inside diameter of 7.8 cm. to calculate the settling velocity, also electronic circuit was designed to calculate the falling time of particles through fluid. Two types of solid particles were used; glass spheres and crushed rocks as irregularly shaped particles with different diameters and compared with each other. The concept of equivalent spherical diameter (D ) was used to calculate the diameters of irregularly shaped particles. The flow behavior for Non-Newtonian fluids was represented by Power-Law model. Two types of polymers were used, Carboxy Methyl Cellulose CMC with concentrations of (3.71, 5, 15 and 17.5) g/l and polyacrylamide with concentrations of (2, 4 and 6) g/l. The results showed that the drag coefficient decreased with increasing settling velocity and particle diameters and sizes; and increased as fluid become far from Newtonian behavior and concentrations and the density difference between particle and fluid. The results also showed that the rheological properties of Non-Newtonian fluids have a great effect on the drag coefficient and particle Reynolds number relationship, especially in laminar-slip regime and decreases or vanishes at transition and turbulent-slip regimes. New correlations were obtained which relates drag coefficient with concentrations of polymers and with flow behavior indices for spherical and irregular shaped particles in Carboxy Methyl Cellulose CMC and polyacrylamide solutions.

Keywords

Fluid flow --- Drag --- Settling


Article
Studying the Factors Affecting the Settling Velocity of Solid Particles in Non-Newtonian Fluids
دراسة العوامل المؤثرة على سرعة الاستقرار بأستخدام الموائع غیر نیوتونیة

Authors: Dina Adil Elia Halagy دينا عادل ايليا --- Muhanned A.R. Mohammed مهند عبد الرزاق محمد
Journal: AL-NAHRAIN JOURNAL FOR ENGINEERING SCIENCES مجلة النهرين للعلوم الهندسية ISSN: 25219154 / eISSN 25219162 Year: 2013 Volume: 16 Issue: 1 Pages: 41-50
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

The aim of this research is to study the factorsaffecting the settling velocity (V S ) in Non-Newtonian fluids which are the rheologicalproperties, concentrations of non-Newtonian fluids,particle shape and size.An experimental apparatus was designedand built, which consists of Perspex pipe of length of160 cm. and inside diameter of 7.8 cm. to calculatethe settling velocity, also electronic circuit wasdesigned to calculate the falling time of particlesthrough fluid.Two types of solid particles were used;glass spheres and crushed rocks as irregularly shapedparticles with different diameters and compared witheach other. The concept of equivalent sphericaldiameter (D S ) was used to calculate the diameters ofirregularly shaped particles.The settling velocity was calculated forNon-Newtonian fluids which represented by Power-Law fluid. Two types of polymers were used,Carboxy Methyl Cellulose with concentrations of(3.71, 5, 15 and 17.5) g/l and polyacrylamide withconcentrations of (2, 4 and 6) g/l.The results showed that the settling velocitydecreased when fluid becomes far from Newtonianbehavior (flow index n decreased) and also whenconcentrations of polymer solutions increased, also,the settling velocity increased with particle diameteror volume.Three sets of equations were concluded; thefirst relates settling velocity with flow index (n), thesecond relates settling velocity with concentrations,and the third relates settling velocity with particlediameter

إن ھدف ھذا البحث ھو دراسة العوامل المؤثرة على سرعة الاستقرار الجسیمات الصلبة بأستخدام الموائع الغیرنیوتونیة مثل الخواص الریولوجیة, تركیز الموائع غیرالنیوتونیة, حجم و شكل الجسیمات الصلبة .تم تصمیم و بناء جھاز مختبري لقیاس سرعة استقرار الجسیمات الصلبة یحتوي على أنبوب بیرسبكس بطول١٦٠ سم و قطر داخلي ٧٫٨ سم, كذلك تم تصمیم دائرة الالكترونیة لقیاس زمن سقوط الجسیمات في السائل.تم استخدام نوعان من الجسیمات الصلبة؛ كرات زجاجیة وصخور غیر منتظمة الشكل ذات أقطار مختلفة لكل منھما وقدتم استخدام نظریة القطر الكروي المكافئ لحساب قطر الجسیمات غیر منتظمة الشكل.تم تطبیق القانون الاسي لتمثیل السوائل غیرالنیوتونیة وقد قیست سرعة استقرار الجسیمات الصلبة . تم استعمالنوعان من البولیمرات ھما كاربوكسي مثیل سیلیلوز بتراكیز( ١٧٫٥،١٥،٥ ،٣٫٧١ )غم/لتر و بولي اكرالاماید بتراكیز ( ٢٦ ،٤ ) غم/لتر . ،و كذلك عندما ( (n) بینت النتائج ان سرعة الاستقرار تقل عند ابتعاد المائع عن السلوك النیوتوني (عندما تقل قیمةیزداد تركیز الموائع غیرالنیوتونیة (المحالیل البولیمریة). كما تزداد سرعة الاستقرار بزیادة قطر و حجم الجسیماتالصلبة.( n) تم استنتاج ثلاث مجامیع من معادلات جدیدة الاولى , تربط سرعة الاستقرار مع دلیل سلوك جریان الموائعوالثانیة تربط سرعة الاستقرار مع التركیز والثالثة تربط سرعة الاستقرار مع قطر الجسیمات الصلبة

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