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Article
EFFECT OF BURNING CYCLES ON THE PHYSICAL PROPERTIES OF CLAY

Authors: Safa Hussain Abid Awn --- Waad Abdul Sattar Hussain --- Hassan Obaid Abbas
Journal: Journal of Engineering and Sustainable Development مجلة الهندسة والتنمية المستدامة ISSN: 25200917 Year: 2019 Volume: 23 Issue: 2 Pages: 79-92
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Natural soil is exposed, like other elements of the construction, to significant changes in temperatures are sources of forest fires or volcanic eruptions or natural bulky. Usually, accompanied by significant changes in temperatures of up to more than 300 degrees centigrade. Therefore, the need arises to study the effect of burning clayey soils, on the grain distribution and distribution of particleboard intricacies and atterbering limit and soil classification, in addition to the direct impact on the variables for the design of foundations such as the cohesion of the soil. The soil used was naturally clayey soil brought from Diyala province with (Liquid limit=56%, Plastic limit=51%, Specific gravity=2.59, the soil is classified as OH (Organic clays of medium to high plasticity). The soil was burned at different temperatures (75- 150- 300- 600 ° C) using special oven for burning at high temperature, the study was directed to investigate the effect of repeat arson for each grade and study changes in soil properties and distribution particleboard and suitability of the construction. The study showed basic change in the particle distribution and Atterbering limits which means changing the engineering properties for the design of foundations construction which indicates the importance of this types of research and potential development to expand in this area and develop ways to put construction solutions for such cases. A reduction percent in plastic limit was 20% and 26% at the end of the fourth cycle at 300oC and 150oC respectively. Author Discoverd that the soil type changed from OH to MH after the first burning cycle at 75oC. With the repetitive burning cycle, more changes on soil properties and type accrue. The soil is Ml after the fourth burning cycle at 75oC.


Article
Effect of Substrate Temperature on Structural and Optical Properties of Cadmium Sulfide Thin Films Prepared by Evaporation Thermal Deposition

Authors: Nadheer Jassim Mohammed --- Hassan Abdullah Mahdi --- Safaa Farhood Madlul --- Adnan Kh. Hasan
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2019 Volume: 30 Issue: 1 Pages: 205-209
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

In this research, we study the effect of substrate temperature (423K and 473K) on structural and optical properties for thin films of cadmium sulfide (CdS) by evaporation thermal dep-osition method on glass substrates and the thickness was about (390nm).XRD analysis showed that CdS thin films prepared at (423K and 473K) are single crystal and have pre-ferred orientation along (002). The grain size was found to be increased with increasing sub-strate temperature, in addition, the atomic force microscopy (AFM) an increase in root mean square (RMS) with an increase in substrate temperature. The absorbance and trans-mittance spectra have been recorded in the range off wave length(400-800nm), and it was found that the transmittance decreases with increasing substrate temperature, while the op-tical band gap decreases from (2.4-2.2ev) for allowed direct transition. CdS thin films should further investigated for application towards the fabrication of solar cells.

في هذا البحث ، قمنا بدراسة تأثير درجة حرارة الركيزة (423 و 473 كلفن) على الخواص التركيبية والبصرية للأغشية الرقيقة لكبريتيد الكادميوم (CdS) بواسطة طريقة الترسيب بالتبخير الحراري على ركائز الزجاج حيث كان سمك الغشاء حوالي 390 نانومتر . أظهر تحليل حيود الاشعة السينية XRD أن أغشية كبريتيد الكادميوم CdS الرقيقة التي تم إعدادها في درجة حرارة (423 و 473 كلفن) هي ذات بلورة منفردة ولها اتجاه مفضل على طول (002). وجد بان الحجم الحبيبي يزداد مع زيادة درجة حرارة الركيزة ، بالإضافة إلى ذلك ، فإن مجهر القوة الذرية (AFM) اضهر زيادة في معدل مربع الجذر التربيعي (RMS) عند زيادة درجة حرارة الركيزة. تم تسجيل اطياف الامتصاصية والنفاذية في مدى نطاق الموجة (400-800) نانومتر، وتبين أن النفاذية تقل مع زيادة درجة حرارة الركيزة ، في حين تنخفض فجوة الطاقة


Article
Effects of Discharge Current and Target Thickness in Dc-Magnetron Sputtering on Grain Size of Copper Deposited Samples
تأثير تيار التفريغ وسمك الهدف في الترذيذ المغناطيسي المستمر على حجم حبيبات النحاس في النماذج المرسبة

Authors: Khalid A. Yahya خالد عباس يحيى --- Ban F. Rasheed بان فيصل رشيد
Journal: Baghdad Science Journal مجلة بغداد للعلوم ISSN: 20788665 24117986 Year: 2019 Volume: 16 Issue: 1 Pages: 84-87
Publisher: Baghdad University جامعة بغداد

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Abstract

A study of the effects of the discharge (sputtering) currents (60-75 mA) and the thickness of copper target (0.037, 0.055 and 0.085 mm) on the prepared samples was performed. These samples were deposited with pure copper on a glass substrate using dc magnetron sputtering with a magnetic flux density of 150 gauss at the center. The effects of these two parameters were studied on the height, diameter, and size of the deposition copper grains as well as the roughness of surface samples using atomic force microscopy (AFM).The results of this study showed that it is possible to control the specifications of copper grains by changing the discharge currents and the thickness of the target material. The increase in discharge current values led to a decrease in height copper grain's values of 20% at a current of 75 mA and target thickness of 0.085 mm. Furthermore, the increasing in the current caused a decrease in the diameter and size values of deposition copper grains. Finally, the surface roughness of the samples was reduced by a 15% by changing the current and target material thickness at 75 mA and 0.085mm respectively.

ان تأثير تيار التفريغ (الترذيذ) (60-75 ) ملي امبير وسمك النحاس الهدف (0.037, 0.055, 0.085) ملم على النماذج الزجاجية المحضرة والمرسب عليها النحاس النقي بواسطة منظومة الترذيذ بالماكنترون المستمر قد تمت دراستها في هذا البحث. درس تأثير هذين العاملين على ارتفاع وقطر وحجم حبيبات النحاس المرسبة وكذلك تمت دراسة الخشونة لسطح النماذج المحضرة بأستخدام مجهر القوة الذرية (AFM). تبين من النتائج انه بالامكان السيطرة على خصائص حبيبات النحاس المرسية عن طريق تغيير تيار التفريغ وسمك مادة النحاس الهدف. ان زيادة تيار التفريغ ادى الى تقليل ارتفاع حبيبات النحاس بنسبة 20% عند تيار 75 ملي امبير وسمك هدف 0.085 ملم.اضافة الى ذلك ان زيادة تيار التفريغ ادى الى تقليل قطر وحجم الحبيبات, وكذلك فان خشونة السطح قلت بنسبة 15% بتغيير التيار الى 75 ملي امبير عند سمك هدف 0.085 ملم.

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