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Article
Fabrication and Characterization of Cu2S /Si Heterojunction Photodetector Based on Spray Pyrolysis of Cu2S on Si
تصنيع ودراسة خصائص كاشف المفرق الهجين Cu2S/Si بطريقة الرش الكيميائي الحراري

Authors: Khaled Z. Yahiya --- Yasmeen, Z. Daood --- Saria D. Ahmed
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2007 Volume: 25 Issue: 2 Pages: 176-182
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In the present work fabrication and characterization of Cu2S/Siheterojunction photodiodes made by spray pyrolysis method using aqueoussolution of CuCl2.2H2O onto n-type silicon substrates made. The externalquantum efficiency of heterojunction was ٣7% at wavelength of 850nm. Theexperimental results show peak relative responsivity around 100mA/w , andmaximum value of detectivity D* (2*1011cm.Hz1/2.w-1).

المصنع Cu2S/Si في هذا البحث جرى تصنيع ودراسة خصائص كاشف المفرق الهجينبطريقة الرش الكيميائي الحراري , وبكفاءة كمية قصوى تصل إلى ٣٧ % عند الطول الموجي850 . تم دراسة الاستجابة الطيفية كدالة للطول الموجي عند درجة حرارة الغر فة . لقد nm850 والتي تصل إلى nm أوضحت النتائج إن قمة الاستجابة الطيفية كانت عند الطول الموجي.(D*=2*1011cm.Hz1/2.w- 100 وأعلى قيمة للكشفية حوالي ( 1 mA/w


Article
P-Cu2S/n-Si Anisotype Heterojunction Solar Cell
تصنيع خلية شمسية ذات المفرق الهجين P-Cu2S/n-Si

Authors: Ali H. Al-Hamdani --- Khaled Z. Yahiya
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2005 Volume: 24 Issue: 7 Pages: 891-897
Publisher: University of Technology الجامعة التكنولوجية

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Abstract


Article
A Small Design of Ultra-Wideband Printed Antenna with Notched and Raked Planar Patch

Author: R.A. Fayadh
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 5 Part (A) Engineering Pages: 456-464
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this research, patch was printed on a rectangular radiating substrate Taconic material. The Taconic material used is TLY-5 of 30 x 30 mm2 dimensions and 1.575 mm thickness. Its Relative dielectric constant (εr) of 2.2 was taken in this research. The rectangular radiator of the proposed design was notched with two-step notches. These notches were cut at the bottom of the slotted patch with three similar dimensions slots. A transmission line feeder feeds the patch with a gap between the printed ground plane and the radiated patch. The proposed antenna design has been simulated and tested using CST microwave studio software and a network analyzer with anechoic chamber respectively. The measured and simulated results demonstrated that the proposed shape of antenna design achieved a very wide of operating impedance bandwidth starting from 3.5 GHz up to 12 GHz at return loss (S11) bellow -10 dB at 0.25 mm size of feed gap. The effects of three feed gap different values and the step notches are illustrated in this paper. The radiation measured and simulated patterns were obtained for omni-directional radiation to be suitable for several users.


Article
Designing and Constructing the Strain Sensor Using Microbend Multimode Fiber
تصميم وبناء متحسس الإجهاد باستخدام خلية الانحناءات الدقيقة للألياف البصرية متعددة الأنماط

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Abstract

The microbend sensor is designed to experience a light loss when force is applied to the sensor. The periodic microbends cause propagating light to couple into higher order modes, the existing higher order modes become unguided modes. Three models of deform cells are fabricated at (3, 5, 8) mm pitchand tested by using MMF and laser source at 850 nm. The maximum output power of (8, 5, 3)mm model is (3, 2.7, 2.55)nW respectively at applied force 5N and the minimum value is (1.9, 1.65, 1.5)nW respectively at 60N.The strain is calculated at different microbend cells ,and the best sensitivity of this sensor for cell 8mm is equal to 0.6nW/N.

تم تصميم متحسس الانحناءات المايكروية لاحتساب خسارة الضوء عند تسليط قوة على متحسس..حيث تسببت الانحناءات المتكررة انتشار الضوء الى الأنماط أعلى. الأنماط الحالية تصبح انماط غير مرشدة .صنعت ثلاث نماذج من الخلايا الانحناءات المايكروية بدرجات تسنن 3,5,8)mm) وأختبرت بأستخدام ليف متعددة النمط ومصدر ليزربطول موجي (850 nm).حيث اعظم قدرة للخلايا (3,5,8mm)هي nW((2.55, 2.7, 3على التوالي عند تسليط قوة مقدارها 5N واقل قدرة تكون 1.9, 1.65, 1.5)nW)على التوالي عند تسليط قوة مقدارها60N . الاستطالة من مختلف خلاياالانحناءات المايكروية تم حسابها, أن أفضل تحسسيه للخلية 8mm تساوي 0.6nW/N.


Article
Effect of tempering on thermal analysis of Al-Ti-Si alloy and its composites
تأثير المراجعة على التحلل الحراري لسبيكة المنيوم – تيتانيوم – سليكون والمواد المتراكبة العائدة لها

Authors: Rana Afif Anaee رنــا عفيف مجيد --- Wafaa Mahdi Salih وفــاء مهدي صالح --- Ban Farhan Dawood بان فرحان داود
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2016 Volume: 14 Issue: 31 Pages: 89-98
Publisher: Baghdad University جامعة بغداد

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Abstract

The investigation of the effect of tempering on thermal analysis of Al-Ti-Si alloy and its composites with MgO and SiC particles was performed. Thermal analysis was performed before and after tempering by DSC scan. Optical microscopy was used to identify the phases and precipitations that may be formed in base alloy and composites. X-ray diffraction test indicated that the Al3Ti is the main phase in Al-Ti-Si alloy in addition to form Al5Ti7Si12 phase. Some chemical reactions can be occurred between reinforcements and matrix such as MgO.Al2O3 in Al-Ti/MgO, and Al4C3 and Al(OH)3 in Al-Ti/SiC composite. X-ray florescence technique is used to investigate the chemical composition of the fabricated specimens. Heat treatment (Tempering) changes the microstructure of base alloy and its composites which was assessed by DSC scan. Generally, three main peaks appeared in DSC represented by GP zone, S phase (precipitations) and dissolution of phases or precipitations. After tempering, composite with SiC particles showed better results than base alloy and composite with MgO. Since the optical microscopy revealed reforming the stable phase Al3Ti with evaporation some gases from composite. DSC analysis showed the stability ofcomposite with SiCwas up to 270oC.DSC, Al-Ti-Si alloy, Composite, SiC, MgO, Al3Ti phase, Al5Ti7Si12.

لقد تم الكشف عن تأثير المراجعة على التحليل الحراري لسبيكة المنيوم – تيتانيوم – سليكون مع مواده المتراكبة المدعمة باوكسيد المغنيسيوم وكاربيد السليكون بنسبة وزنية 1% من خلال فحص المسعر التفاضلي الحراري. اجري فحص البنية بالمجهر البصري لتشخيص الاطوار المتكونة في السبيكة الاساس والمواد المتراكبة المدعمة وقد اثبت فحص الحيود بالاشعة السينية تكون الطور الرئيسي Al3Ti بالاضافة الى تكوين الطور Al5Ti7Si12 بالاضافة الى اطور اخرى تتكون ضمن المواد المتراكبة مثل MgO.Al2O3و Al4C3 و Al(OH)3واطوار اخرى. ان المعاملة الحرارية تغير من تفاعلات التبلور والانصهار الظاهرة في فحص التحلل الحراري باستخدام المسعر الماسح التفاضلي. ان قمم التبلور الرئيسية الظاهرة في فحص التحلل الحراري هي ظهور طبقة GP وقمة الطور البيني S وقمة الاطوار غير المتماسكة. ان المادة المتراكبة المدعمة بدقائق كاربيد السليكون تظهر من خلال الفحص بالمسعر الماسح التفاضلي استقراراً حرارياً واظحاً الى حد 270 درجة مئوية.


Article
The effect of aging on tensile strength of two maxillofacial silicone materials before and after pigmentation

Authors: Afeiaa Lateef Jassim --- Mohammed Abdul Hussain
Journal: Journal of Oral and Dental Research مجلة طب الفم والاسنان ISSN: 23106417 Year: 2019 Volume: 6 Issue: 1 Pages: 40-50
Publisher: Iraqi Association for Oral Research الجمعية العراقية لبحوث طب الفم

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Abstract

Background The approximate life span of a silicone maxillofacial prosthesis is as short as after 4-14 months of usage, then a new prosthesis should be fabricated. But now many researchers have been directed toward improvement of properties silicone elastomeric materials. The objective of this study is to evaluate the effect of aging on tensile strength of two types of silicone materials used in the maxillofacial prostheses (VST-30 and VST-06) after artificial weathering for 100, 200 and 300 hours, and then comparing between the two selected materials in terms of selected artificial weatheringperiods. Material and methods a sample of 160 specimens were prepared anddivided into two main groups according to the types of elastomeric silicone (VST-30 and VST-06). Then each group subdivided into 8 divisions, (n=10). Two groups, one for clear and one pigmented as control groups before experimental weathering .While the experimental groups divided into clear and pigmented groups treated with artificialweathering for 100, 200 and 300 h. Results after different weathering cycles theresults show that there was no significant difference in the tensile strength for VST-30 silicone material pigment before and after weathering. While there was a highly significantdifference in the tensile strength for VST-06 pigmented silicone before and after weathering. Both VST-30 and VST-06 non-pigmented groups showed a highly significant change in the tensile strength after different weathering cycles. Conclusionsthe superior type for mechanical properties after difference cycles weathering was for VST-30 and incorporation of rayon flocking prevents the silicone materials from rapid degradation under artificial weathering and this may lead to increase in the service life of silicone prosthesis.

Keywords

Background The approximate life span of a silicone maxillofacial prosthesis is as short as after 4-14 months of usage --- then a new prosthesis should be fabricated. But now many researchers have been directed toward improvement of properties silicone elastomeric materials. The objective of this study is to evaluate the effect of aging on tensile strength of two types of silicone materials used in the maxillofacial prostheses --- VST-30 and VST-06 after artificial weathering for 100 --- 200 and 300 hours --- and then comparing between the two selected materials in terms of selected artificial weathering periods. Material and methods a sample of 160 specimens were prepared and divided into two main groups according to the types of elastomeric silicone --- VST-30 and VST-06. Then each group subdivided into 8 divisions --- n=10. Two groups --- one for clear and one pigmented as control groups before experimental weathering .While the experimental groups divided into clear and pigmented groups treated with artificial weathering for 100 --- 200 and 300 h. Results after different weathering cycles the results show that there was no significant difference in the tensile strength for VST-30 silicone material pigment before and after weathering. While there was a highly significant difference in the tensile strength for VST-06 pigmented silicone before and after weathering. Both VST-30 and VST-06 non-pigmented groups showed a highly significant change in the tensile strength after different weathering cycles. Conclusions the superior type for mechanical properties after difference cycles weathering was for VST-30 and incorporation of rayon flocking prevents the silicone materials from rapid degradation under artificial weathering and this may lead to increase in the service life of silicone prosthesis.

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