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Article
Electrochemical Behavior of Chemical Conversion Coated Aluminum ASA6061in Chromic Acid

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Abstract

The corrosion behavior of bare and chemical conversion coated (through anodizing) aluminum AS4 6061 in stagnant chromic acid solutions. Solutions of 2, 6 & lO wt% Cro3, at 45°C have been investigated using polarization ion technique. The anodizing experiments were conducted under fixed conditions of 35 minute exposure time and 30 volt supplied voltage. The most important feature achieved was the great d(fference in behavior between the anodic polarization curves for bare and anodized aluminum in different concentrations of chromic acid solutions.


Article
Novel method for visualizing of the coated microbubbles using the electron microscopy

Authors: Aladdin Majeed Hasson --- Bassam T. mohammad --- Mazin K. Hamid --- Abdul k. Hussein Dagher
Journal: Mustansiriya Medical Journal مجلة المستنصرية الطبية ISSN: 20701128 22274081 Year: 2016 Volume: 15 Issue: 2 Pages: 75-78
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

The microbubbles have many important acoustics applications, some of these applications are in medical uses such as ultrasound contrast agents and drug delivery. The efficiency and stability of the microbubbles are depending on many factors one of them is the structure of their shells. There is a significant need to visualize this structure to understand and optimize the bubbles behavior. Direct observation such scanning electron microscopy (SEM) and transmission electron microscopy (TEM) pose a big technical challenge because of the vacuum environment required by these devices. In addition, the freeze-fracture technique with TEM is long and expensive. In the present study, a novel modified method was used to overcome these challenges and consider a simple,


Article
Quantitative assessment of Mutans Streptococci adhesion to coated and uncoated orthodontic archwires (In vitro study)

Authors: Aliaa Abdul Rhman Al-Lami علياء عبد الرحمن اللامي --- Iman I. Al-Sheakli ايمان الشيخلي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2014 Volume: 26 Issue: 4 Pages: 156-162
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The development of orthodontic biomaterials that attract less biofilm has been a goal for decades.Adhesion and colonization of cariogenic streptococci are considered to play key roles in the development ofenamel demineralization related to orthodontic materials. The aim of this study was to quantitatively evaluate theMutans streptococci adhesion to coated orthodontic archwires (Epoxy and Teflon) and uncoated archwires(stainless steel and nickel-titanium) with respect to incubation time in the presence and absence of saliva.Material and Method: Six types of archwires stainless steel and nickel titanium with two type of coating (Epoxy, Teflon)were used in this study. Twelve specimens of each archwire were incubated in sterilized unstimulated whole saliva(for the study group) and phosphate-buffered saline (for control group) for 2 hours, then incubated with suspensionof Mutans streptococci allowed to adhere for (5,90,180 minutes). Adhesion was quantitated by a microbial culturetechnique by treating the archwires with adhering bacteria with trypsin and enumerating the colony forming unit(CFU) counts of bacteria recovered after cultivation by using Dentocult SM kit.Results: There was significant difference among the tested archwire types in each time interval with the highestbacterial adhesion on the NiTi archwires in the absence of saliva. In the presence of saliva, the results revealed nonsignificantdifference at 5 min. while there was significant difference at 90 min and highly significant difference at 180min.Conclusion: The adherence of Mutans streptococci was decreased in the presence of saliva on different archwiresand the extended incubation time was significantly related to increase colony forming unit of Mutans Streptococci


Article
Pullout strength behaviour of self-compacted concrete in aggressive solutions

Authors: Maha Sabhan --- Adnan Al-Sibahy
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2019 Volume: 12 Issue: 4 Pages: 260-266
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

The aim of this study was to investigate the pullout strength behaviour of self-compacted concrete under corrosion conditions. Block samples with two configurations were formulated. A total number of twelve block samples in addition to 24 cubes were tested. The hardened concrete samples were either cured in tap water or exposed to salt solution. A suitable epoxy was used for coating part of the formulated samples. The preliminary mechanical properties and the rate of corrosion were firstly measured, the pullout was then carried out. A comparison was also made with the relevant code of practice. The results obtained showed that both compressive strength and density features exhibited a notable increase at an early age when the samples are exposed to salt solution. The adverse effect of such curing condition appeared at the later ages when the corrosion rate became more intensive. The highest decrease in the value of pullout strength was observed for the reinforced concrete block samples containing epoxy coating reaching to 44.5% less than those cured in tap water.


Article
Effect of Multi-Coats of Cutting Tools on Surface Roughness in Machining AISI 1045 Steel
تأثير عدد طبقات الكساء لعدد القطع على الخشونة السطحية عند تشغيل صلب نوع ( 1045 AISI)

Author: Maan Aabid Tawfiq
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2008 Volume: 26 Issue: 12 Pages: 1523-1533
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, orthogonal machining tests in dry turning method are performed on(AISI 1045 St.), in order to examine the influences for the type and number ofcoatings on surface roughness. The cutting tools used are (TiN, TiN/TiC, andTiN/Al2O3/TiC); multiple layers coated cemented carbide inserts. The tests areperformed at five different cutting speeds (80, 112, 155, 220 and 300) m/min,while the feed rates are kept to be (0.08, 0.11, 0.14, 0.16 and 0.2) mm/revrespectively, at constant depth of cut and tool geometry. The results showed that(TiN/TiC) coated cutting tools gave best results for surface finish compared withTiN/Al2O3/TiC, TiN and uncoated tool, for all the selected machining conditions.The experimental results showed that, when the cutting speed is increased from(80-300)m/min and feed rate is reduced by (250%), the values of surface roughnessis decreased by: (20%) for uncoated tool insert ,(27%) for single coated layer insert(TiN), (55%) for double coated layer insert (TiN/TiC) and (49%) for triple coatedlayer insert (TiN/Al2O3/TiC).

يتضمن هذا البحث دراسة لمجموعة تجارب مختبرية تحت ظروف القطع المتعامد عند التشغيلوذلك لغرض معرفة تأثيرنوع وعدد طبقات الكساء لعدة القطع ، ( AISI 1045 St.) الجاف لصلبعلى الخشونة السطحية للمعدن المشغل. تم استخدام ثلاثة أنواع من مواد الكساء للعدة منها: المكسية بكلفي حين كانت العدة الرابعة غير مكسية. .(TiN/Al2O3/TiC و TiN/TiC وTiN) : من المواد التاليةتم اختيار خمس قيم من سرع القطع وهي:112,80 , ) م/دقيقة ، كذلك تم اختيار خمس قيم اخرى للتغذية وهي ( , 0.11 300 ,220, 155)0.140,0.08 ملم/دوره، في حين تم نتبيت قيمة عمق القطع وهندسية عدة القطع. أظهرت , 0.16, 0.2أعطت أقل القيم من حيث الخشونة السطحية (TiN/TiC) النتائج بأن عدة القطع المكسية بطبقتينوتحت حميع ظروف القطع المختارة وذلك بمقارنتها مع النوعين الاخرين وهما العدة ذات الطبقة الواحدةوذات الثلاث طبقات كساء فضلا عن عدة القطع الغير مكسية. حيث وجد عمليا بانه عند زيادة سرعة300 ) م/دقيقة وعند تقليل قيم التغذية بمقدار( 250 %) فان قيم الخشونة السطحية تنخفض - القطع من ( 80،(TiN) بمقدار يصل الى: ( 20 %) لعدة القطع الغير مكسية، ( 27 %) لعدة القطع المكسية يطبقة واحدةو( 49 %) لعدة القطع المكسية بثلاث طبقات ، (TiN/TiC) %55 ) لعدة القطع المكسية بطبقتين من ).(TiN/Al2O3/TiC)


Article
COATED CARBIDE CUTTING TOOLS PERFORMANCE IN HIGH SPEED MACHINING PROCESSES
اداء عدد القطع الكاربيدية المطلية في عمليات التشغيل غند السرع العالية

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Abstract

High-speed machining (HSM) has emerged as a key technology in rapid tooling andmanufacturing applications. The present work studies the effect of cutting parameters (cuttingspeed, feed and depth of cut) in turning process applied on C-60 steel using multi- coated carbidecutting tools at high cutting speeds. The influence of cutting parameters on a cutting forces, toolwear and surface roughness are analyzed. The importance of orthogonal force components tosurface finish and tool wear are explored. The results show that cutting forces has a very strongcorrelation with surface finish and that increased spindle speeds lead to far superior surface finish.Tool wear measurements demonstrated the capability of such coated carbide tools in turning steelwith reasonable low tool wear (i.e. high tool life). Forces measured resulted in relatively low values.The cutting component (Fc) isthe largest of all. For the different cutting conditions studied, the feedrate has the greatest influence on force and tool wear.

ان عمليات التشغيل عند السرع العالية هي تكنولوجيا جديدة تم ادخالها حديثا في العمليات الانتاجية نتيجة للتطور الحاصل في مجال عدد القطع . في هذا البحث تمت دراسة استخدام سرع القطع العالية في عملية الخراطة عند ظروف القطع المختلفة (سرعة القطع , التغذية , عمق القطع) على قوى القطع ,


Article
Removal of Phenol Compounds from Aqueous Solution Using Coated Sand Filter Media

Author: Asrar Al-Obaidy اسرار عبد الله حسن
Journal: Iraqi Journal of Chemical and Petroleum Engineering المجلة العراقية للهندسة الكيمياوية وهندسة النفط ISSN: 19974884/E26180707 Year: 2013 Volume: 14 Issue: 3 Pages: 23-31
Publisher: Baghdad University جامعة بغداد

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Abstract

Coated sand (CS) filter media was investigated to remove phenol and 4-nitrophenol from aqueous solutions in batch experiments. Local sand was subjected to surface modification as impregnated with iron. The influence of process variables represented by solution pH value, contact time, initial concentration and adsorbent dosage on removal efficiency of phenol and 4-nitrophenol onto CS was studied. Batch studies were performed to evaluate the adsorption process, and it was found that the Langmuir isotherm effectively fits the experimental data for the adsorbates better than the Freundlich model with the CS highest adsorption capacity of 0.45 mg/g for 4-nitrophenol and 0.25 mg/g for phenol. The CS was found to adsorb 85% of 4-nitrophenol and 65% for phenol at an initial concentration of 25 mg/ℓ


Article
Experimental and FEM Study of Coated Inserts on Cutting Forces in Orthogonal Cutting
دراسة عملية وتحليلية بطريقة العناصر المحددة لتأثير طبقات كساء عدد القطع على قوى القطع في القطع المتعامد

Authors: Maan A. Tawfiq --- Basim S. Sahib
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2015 Volume: 33 Issue: 3 Part (A) Engineering Pages: 694-702
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this study, an attempt has been made to investigate and simulate the influence of coated layers, on the cutting force components in orthogonal turning process using AISI 1010 steel.A series of experimental and numerical tests have been done with four types of inserts including uncoated, coated tool with (TiN), (TiN /TiCN) and (TiN /Al2O3/ TiCN) using the special FEA code (DEFORM-2D). The turning tests were conducted at five different cutting speeds (45, 65, 97, 145, and 206 m/min.), while feed rate and depth of cut were kept constant at (0.2 mm/rev.) and (1.2 mm) respectively. The results show that the minimum force is achieved when using TiN/TiCN insert compared with other inserts in all cutting conditions. The cutting force components (tangential and feed force) are decreasedby (22% and 69% respectively) when the cutting speedincreases from (45 to 206) m/min. The maximum relative difference between simulated and measured values is less than (17%).

تضمن هذا البحث محاولة لدراسة عملية وتحليلية لمحاكاة تأثير نوع وعدد طبقات كساء عدد القطع و سرعة القطع على مركبات قوى القطع في حالة القطع المتعامد عند تشغيل صلب AISI 1010. تم اجراء مجموعة من التجارب العملية والتحليلية لاربعة انواع من لقم عدد القطع غير المكسية منها والمكسية بطبقة واحدة من (TiN) و طبقتين (TiN/TiCN) وثلاث طبقات كساء (TiN/Al2O3/TiCN). تم اختيار خمسة قيم لسرع القطع متمثلة ب(45,65,97,145 and 206 m/min.) في حين تم تثبيت قيمة معدل التغذية و عمق القطع(0.2 mm/rev.)(1.2mm) على التوالي لجميع التجارب.اظهرت النتائج بأن اقل قيمة لقوى القطع تم استحصالها عند التشغيل باستخدام عدة قطع مكسية بطبقتين (TiN/TiCN) وذلك تحت جميع ظروف القطع المذكورة اعلاه. في حالة زيادة سرعة القطع من (45m/minالى (200m/min.تقل قوة القطع بمركبتيها (المماسية وقوة التغذية) بمقدار (22%،%69) على التوالي . كما اظهرت النتائج النهائية وجود تطابق كبير للقيم العملية مع القيم التحليلية بنسبة خطأ لا تتجاوز (17%) .


Article
An Evaluation of Corrosion Pits in Esthetic Coated Stainless Steel Orthodontic Archwires in Dry and Wet Environment at Different Intervals (An In Vitro Study)

Authors: Shaimaa K. Mohsin شيماء منذر --- Iman I. Al-Sheakli ايمان الشيخلي
Journal: Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد ISSN: 16800087 Year: 2016 Volume: 28 Issue: 1 Pages: 153-157
Publisher: Baghdad University جامعة بغداد

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Abstract

Background: The demand for esthetic orthodontic appliances is increasing; so the esthetic orthodontic archwireswere introduced. Among them, Teflon and Epoxy coated stainless steel archwires. The amount of force availablefrom the archwire depends on the structural properties and susceptibility to corrosion. All metallic alloys are changedduring immersion in artificial saliva, chlorhexidine mouthwash andtoothpaste, but their behaviors differ from one typeto another. They corrode at different rates, which lead to decrease the amount of force applied to the teeth. This invitro study was designed to evaluate the corrosion pits in stainless steel archwires coated with Teflon and with Epoxyin dry and after immersion in artificial saliva, chlorhexidine(0.2%) (Parodontax) and toothpaste media (Sensodyne) for(1, 7 and 28) days intervals. Moreover, this study is intended to compare the corrosion pits for each type of archwiresat these different media among all intervals.Materials and Methods: In this study, two hundred forty pieces of orthodontic wires of Teflon (Hubit) coated Stainlesssteel (120 pieces) and epoxy (Orthotechnology) coated Stainless steel (120 pieces), rectangular in cross section, size(0.019 x 0.025) inch and 15mm in length divided into four groups according to immersion media: (dry environmentgroup, artificial saliva group, chlorhexidine group and toothpaste group). The atomic force microscope was used tomeasure the corrosion pits for all samples at dry and wet conditions and after different immersion periods.Results: Statistical analysis showed that there was a highly significant increase in the corrosion pits of Teflon coatedstainless steel archwires (P ≤ 0.05) in wet environment at 28 days immersion period.The highest corrosion pits werefound in the toothpaste medium for the two archwire types at 28 days immersion period.Conclusion: We can conclude that Epoxy coatedstainless steel archwires are indicated to be used above Tefloncoated stainless steel archwires in terms of corrosion resistance. IfTeflon coated stainless steel archwires should to beused, they should be change in shorter periods than Epoxy coated stainless steel archwires type


Article
Coated Wire and Multiwalled Carbon Nanotube Composite Coated Wire Sensors for Determination of Chlorpromazine Hydrochloride in Pharmaceutical Preparations.

Authors: Riyadh M. Jihad رياض محمد جهاد --- Ismael K. Al-Hitti اسماعيل خليل الهيتي --- Adawiya J. Hayder عدوية جمعة حيدر
Journal: Journal of university of Anbar for Pure science مجلة جامعة الانبار للعلوم الصرفة ISSN: ISSN:PISSN: 19918941/EISSN: 27066703 Year: 2014 Volume: 8 Issue: 3 Pages: 20-27
Publisher: University of Anbar جامعة الانبار

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Abstract

fabrication and performance characteristics of novel potentiometric sensors for the determination of chlorpromazine hydrochloride are described. The proposed sensors include a coated copper wire sensor and a multiwalled carbon nanotube (MWCNT) composite coated copper wire sensor. The sensors are based on the chlorpromazine-phosphotungstate ion associate as electroactive material. The developed sensors exhibited near nernstian slopes of 53.69 and 57.31 mV concentration decade-1 at 25 ◦C, in the concentration range 5.0 x 10-5 – 1.0 x 10-2 mol L-1 chlorpromazine hydrochloride with limits of detection of 4.8 x 10-5 and 4.9 x 10-5 mol L-1 chlorpromazine hydrochloride for coated copper wire sensor and a (MWCNT) composite coated copper wire sensor, respectively. The proposed sensors exhibited good selectivity for chlorpromazine with respect to a large number of inorganic cations, amino acid and sugars. The developed sensor was successfully applied for the potentiometric determination of chlorpromazine hydrochloride in the pharmaceutical preparations and human urine samples.

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