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A Comparison between cooking tea-waste and commercial activated carbon for removal of chromium from artificial wastewater
المقارنة بين استخدام مخلفات الشاي المطبوخ و الكاربون المنشط التجاري في إزالة الكروم السداسي من المياه المتخلفة المصنعة

Author: Hadi Ghali Attia هادي غالي عطية
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2012 Volume: 16 Issue: 1 Pages: 307-325
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The compare Cr (VI) adsorption characteristics removing from artificial wastewater by using decolorized cooking tea waste (CTW) and commercial activated carbon (AC) were examined. Adsorption experiments were carried out in a batch process and various experimental Parameters such as effect of pH, rpm, temperature, adsorbent dosage, contact time, and initial chromium ion concentration on percentage removal have been studied. Adsorption process was found for two adsorbents to be highly pH dependent. The maximum removal took place at the pH 2. A significant fraction of the total Cr (VI) uptake was achieved within 180 min and initial concentration of 50 mg/L. The maximum efficiency of chromium removal was 99.5% and 99.4% for CTW and AC, respectively and maximum adsorption capacity of chromium ion by using AC and CTW were 42.42, 42.46 mg/g respectively. Studies showed that the Freundlich adsorption model better fitted with the results than Langmuir with R2 equal 0.991 and 0.974 for AC and CTW, respectively. The chromium uptake by the CTW and AC was best described by pseudo-second order rate model. This investigation verifies the possibility of using CTW as a low cost material for the removal of chromium from aqueous solution comparing with AC.

يهدف البحث الى المقارنة في خواص الامتزاز بين استخدام مخلفات اوراق الشاي المطبوخ والكاربون المنشط. حيث عملية الامتزاز اجريت في منظومة دفعية وتم فيها دراسة المعاملات التالية مثل الرقم الهيدروجيني, سرعة الخلط, درجة الحرارة, وزن المادة المازة, زمن الخلط و تركيز الاكروم الاولي على نسبة الازالة. حيث اثبتت عملية الامتزاز اعتماد كبير على الرقم الهيدروجيني حيث كانت اعلى نسبة امتزاز عند الرقم الهيدروجيني يساوي (2). وكان زمن الاتزان بالنسبة الى تركيز الاكروم السداسي البالغ (50) ملغرام/لتر هي 180 دقيقة. وكانت النسبة العظمى لإزالة الكروم باستخدام مخلفات أوراق الشاي المطبوخ هي 99.5% وبالنسبة الى الكاربون المنشط كانت 99.4% إما بالنسبة إلى قيمة الامتزاز العظمى لايون الكرم باستخدام الكاربون المنشط ومخلفات أوراق الشاي المطبوخ هي 42.42 و 42.46 ملغرام/غرام على التوالي. بينت الدراسة ان النتائج اكثر انطباقا مع موديل فريندلش منه مع موديل لانكماير. وكذلك انطباق البيانات مع الموديل من الدرجة الثانية من الناحية الكينماتيكية منه مع الموديل من الدرجة الاولى. ومن هذا البحث يتبين انه بامكان استخدام مخلفات الشاي المطبوخ كمادة رخيصة الثمن في عملية ازالة الكروم مقارنة مع الكاربون المنشط التجاري.


Article
Chromium and Vanadium level in children with Type 1 diabetes

Authors: Walaa A. A. Al-Jedda --- Abdul kareem Y. J. Al-Samarraie
Journal: Mustansiriya Medical Journal مجلة المستنصرية الطبية ISSN: 20701128 22274081 Year: 2012 Volume: 11 Issue: 1 Pages: 63-68
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Aims: To measure the level of Chromium and Vanadium in the serum of Iraqi children with Type 1 diabetes in an effort to evaluate the status of these elements. Patients and Methods: Thirty – five children with type 1 diabetes were involved in the study. They were all out- patients attending the National Diabetes Center. Thirty seven non- diabetic apparently healthy children were included in the study to compare these controls for age and sex with the diabetics patients. Plasma glucose was measured using PAP – Enzymatic method. HbA1c was estimated by using non–ion exchange High Performance Liquid Chromatography. Trace elements including chromium and vanadium were determined by flameless atomic absorption. Results: All diabetics showed a significantly decrease in both element (Cr and V.) studied as compared with their controls matched for age and sex. [(17.35 ± 1.81 ng/ml) (18.76 ± 2.9 ng/ml) and (43.47 ± 0.26 ng/ml) (26.20 ± 0.97 ng/ml) (P< 0.0001)] respectively. In addition to that, there was a significant positive correlation between age and both plasma glucose and HbA1c levels for those patients with type 1 diabetes (r=0.37, 0.33) (p<0.05) respectively, while there was a significant negative correlation between age and both serum Cr and V levels (r= 0.45, 0.52) (p<0.05) respectively. Results from controls, showed a significant positive correlation between both plasma glucose and HbA1c with serum Cr level (r= 0.39, r= 0.35) (p<0.05) respectively, while there was a significant negative correlation between age and serum Cr level (r= 0.40) (p<0.05). Conclusions: Due to deficiency of these trace elements, supplementation is indicated to diabetics especially to those with diabetic complications. Things such as eating a better daily diet, in which elements content is optimal, is .considered few of the major controllable areas of our lives.


Article
Comparison of certain mechanical properties including deflection fatigue resistance of Cobalt Chromium alloy & Nylon tooth colored clasping materials

Authors: Azhar I.M. Al-Awady ازهر العوادي --- Widad Abdul-Hadi Al-Nakkash وداد النقاش
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2012 Volume: 24 Issue: 2 Pages: 6-10
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: This study was conducted to test & compare the mechanical properties including the ultimate tensilestrength, yield strength, modulus of elasticity, ductility & deflection fatigue resistance of Cobalt Chromium alloysamples, Flexite Supreme samples & commercially available Nylon samples, thus evaluating efficiency & life timeexpectancy of these materials.Materials and methods: A reproduction mold was made from addition silicon reproduction material to produce waxpatterns of standardized measures, these sacrificial patterns were used to produce fifty samples of each of the threematerials (a total of 150 samples). These specimens were tested by tensile testing machine and deflection fatigueresistance machine.Results: The tested materials expressed differences in their mechanical properties that were highly significant in allcomparisons.Conclusions: Cobalt Chromium alloy, aside from its poor aesthetic, performs better in shallow deflection and have areasonable life expectancy. Flexile supreme is more aesthetically acceptable, with better performance and longerlife expectancy. Commercial nylon is with poor quality rendering it unusable

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