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Article
Preparation and Characterization Study of Porous Silicon Doped with Cu and Ag

Authors: U. M. Nayef --- A.M. Abdul Hussein --- A. J. Kata
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 1 Part (B) Scientific Pages: 8-12
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this paper, porous silicon was prepared by using electrochemical etching technique of p-type silicon acceptor, with a resistivity of 1.5-4Ohm.cm, using hydrochloric acid with concentration of 24%. The etching current density effect 4, 12, 20mA/cm2 was carried out at constant etching time of 15min. The structural characteristics of the porous silicon and the doped porous silicon were studied and found an expansion in the spectrum of the X-rays and a simple shift in the diffraction angles while maintaining the surface direction (111). The morphological properties were studied using the atomic force microscope which showed pores formation and gives the pore diameter within the range of 19.08 to 44.73nm for the prepared samples. It was also noted that the rate of pore diameter and the thickness of the porous silicon layer increased with increasing etching current density. Electrical characteristics of the nanoscale porous silicon layer and the doped porous silicon with silver and copper showed that Current-Voltage (I-V) characteristics of the prepared samples to be a rectifying behavior. An improvement in the electrical characteristics of the doped porous silicon samples was observed


Article
Study of the Influence of Incorporation of Gold Nanoparticles on the Modified Porous Silicon Sensor for Petroleum Gas Detection

Authors: A.M. Alwan --- A.B. Dheyab --- A.J. Allaa
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 8 Part (A) Engineering Pages: 811-815
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, the influence of alloying the porous surface with uniform distributed gold nanoparticles on the characteristic porous silicon gas sensors for petroleum gas detection has been fabricated and studied extensively. Well-controlled gold nanoparticles were prepared by employing the simple dipping process of the macro porous silicon surface in diluted concentrations of HAuCl4 salt aqueous solution. The sensing properties of the prepared porous silicon-based sensors, sensitivity response and recovery times at room temperature operating in CO gas were studied. The sensitivity of alloyed porous silicon increased from 38% to about 82% incorporation of gold nanoparticles. The lowest gas pressure detection process of CO molecules was improved from 1 mbar to 0.5 mbar. The surface alloying with rounded gold nanoparticles improved the integrated specific surface area of the alloyed porous silicon/gold nanoparticles structure, so efficient gas developed with the low-cost process.


Article
A study of kidney Parameters Induced by Porous Silicon Nanoparticles

Authors: K. H. Jwaid --- M. S. Jabir --- U. M. Nayef
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 2 Part (B) Scientific Pages: 150-153
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

Nanoparticles are a special group of materials with unique features and extensive application in diverse fields .The present work demonstrates the toxicity effect of porous silicon nanoparticalse on kidney parameter which is prepared by electrochemical etching method. We conformed the synthesis of porous silicon nanoparticles by using structures and optical properties from through scanning electron microscope techniques and measuring absorbance of color. The study of toxicity effect of these nanoparticles on the kidney parameters in laboratory animals by used five groups was studied. Injected of porous silicon nanoparticles in the intraperitoneal at concentration of 1mgkg. The results of biochemical assay (urea and creatinine) compared with the control groups, for a period of four weeks was confirmed with Histology section of kidney. Our results showed that no significant differences in levels (urea and creatinine) between the test groups when compared with controls groups. This Results indicates no toxic effect of porous silicon nanoparticles in kidney parameters


Article
Synthesis and Study of Modified Nanostructure Porous Silicon Layers for Chemical Gas Sensing

Authors: A.D.Thamir --- A. L. Abed --- F. Q. Mohammed --- A. S. Hasan
Journal: Engineering and Technology Journal مجلة الهندسة والتكنولوجيا ISSN: 16816900 24120758 Year: 2017 Volume: 35 Issue: 10 Part (A) Engineering Pages: 970-974
Publisher: University of Technology الجامعة التكنولوجية

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Abstract

In this work, We prepared a modified nanostructure porous silicon (PS) layers for effective chemical gas sensing. Nanopore covered microporous silicon gas sensor has been fabricated using electrochemical etching in an HF acid and ethanol solution. A porous silicon (PS) surface has been modified using selective depositions formed from metal to enhance the response to Sensing of CO2. (PS) has been interest for gas sensing because of the exceptional gathering of importent features. By setting the process parameters,the porosity, pore size, and the morphology can be modifid and practically controlled. The modified porous silicon layers were characterized using different techniques such as scanning electron microscopy(SEM)and a series of electrical characterizations to study the structures in the contact of the carbon dioxide was achieved.


Article
Toxicity of Porous Silicon Nanoparticles on Liver of Mice

Author: Kareem H. Jwaid1
Journal: Al-Mustansiriyah Journal of Science مجلة علوم المستنصرية ISSN: 1814635X Year: 2017 Volume: 28 Issue: 3 Pages: 209-213
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Nanoparticles are a special group of materials with unique features and extensive application in diverse fields. The present work demonstrates the toxicity impact of porous silicon nanoparticles (PSNPs) on kidney parameter which is prepared by electrochemical etching method. the synthesis of porous silicon nanoparticles are conformed by using structural and optical properties from through scanning electron microscope and atomic force microscopy techniques. The effect of toxicity of these nanoparticles on the liver parameters in laboratory animals use four groups each groups involve three duplicities was studied. Injected of porous silicon nanoparticles in the intraperitoneal at concentration of 1mg/kg. The results of biochemical assay Aspartate Amino-Transferase (GOT), Alanine Amino-Transferase (GPT), Alkaline Phosphatase (ALP) were compared with the control groups, for four weeks and then confirm a result was made with Histological study for section of liver. Results show no significant differences in levels (GOT, GPT, ALT) among the test groups via comparison with controls groups. This Result indicates no toxic effect of porous silicon nanoparticles' on kidney parameters


Article
Synthesis of Al/OPS/PS/Si/Al by RTO and its detection properties

Journal: Journal of College of Education مجلة كلية التربية ISSN: 18120380 Year: 2017 Issue: 1 Pages: 129-138
Publisher: Al-Mustansyriah University الجامعة المستنصرية

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Abstract

Porous silicon oxide (PSO) was prepared by rapid-thermal oxidization (RTO) of porous silicon that was formed on silicon substrate with optimum conditions. The porosity was approximately (65%) and layer thickness was (8μm). Photoluminescence (PL) observed a broad peak of porous silicon (PS) at 690 nm (1.79eV) with full width at half maximum (FWHM) of about 130 nm while the photoluminescence value of PSO located at 670 nm (1.85eV) with FWHM value of 140 nm. The lower values of resistances are 95.8 kΩ and 18kΩ of PSO and PS respectively. Response time of porous silicon detector about (9) second and the recovery time is about (6.5) second. The response time of UV detector for porous silicon oxide is (4) second and the recovery time about (8) second.The (PSO) sample exhibited high detection for incident ultra-violet (UV) light with and without bios

تم تحضير السليكون المسامي المؤكسد بطريقة التأكسد الحراري السريع للسليكون المسامي الذي حضرعلى شريحة من السليكون بشروط منتخبة. المسامية كانت تقريبا 65% وسمك الطبقة 8 مايكرومتر. التألق الضوئي للسليكون المسامي بين بأن له قمة عريضة عند 690 نانومتر (1.79 الكترون فولت ) مع اعلى شدة عند منتصف القمة 130 نانومتر بينما قياسات التألق الضوئي بالنسبة الى السليكون المسامي المؤكسد فبينت قمة عند 670 نانومتر (1.85 الكترون فولت ) مع اعلى شدة عند منتصف القمة 140 نانومتر. قياسات المقاومية للسليكون المسامي المؤكسد وللسليكون المسامي هي 95.8 و18 كيلو اوم على التعاقب. زمن الاستجابة لكاشف السليكون المسامي هو 9 ثانية وزمن الرجوع 6.5 ثانية بينما زمن الاستجابة لكاشف السليكون المسامي المؤكسد هو 4 ثانية وزمن الرجوع 8 ثانية. كاشف السليكون المسامي المؤكسد اظهر كشفية عالية للاشعة فوق البنفسجية مع او بدون انحياز.


Article
Porous silicon prepared by photo electrochemical etching assisted by laser
تحضير السليكون المسامي بالتنميش الكهروكيمياوي بمساعدة الليزر

Authors: Falah A-H Mutlak فلاح عبد الحسن مطلك --- Ahmed B. Taha احمد باسم طه
Journal: Iraqi Journal of Physics المجلة العراقية للفيزياء ISSN: 20704003 Year: 2017 Volume: 15 Issue: 32 Pages: 122-129
Publisher: Baghdad University جامعة بغداد

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Abstract

Porous silicon (PS) layers are prepared by anodization for different etching current densities. The samples are then characterized the nanocrystalline porous silicon layer by X-Ray Diffraction (XRD), Atomic Force Microscopy (AFM), Fourier Transform Infrared (FTIR). PS layers were formed on n-type Si wafer. Anodized electrically with a 20, 30, 40, 50 and 60 mA/cm2 current density for fixed 10 min etching times. XRD confirms the formation of porous silicon, the crystal size is reduced toward nanometric scale of the face centered cubic structure, and peak becomes a broader with increasing the current density. The AFM investigation shows the sponge like structure of PS at the lower current density porous begin to form on the crystalline silicon, when the current density increases, pores with maximum diameter are formed as observed all over the surface. FTIR spectroscopy shows a high density of silicon bonds, it is very sensitive to the surrounding ambient air, and it is possible to oxidation spontaneously.

في ھﺬا اﻟﺒﺤﺚ تم تحضير طبقات السيليكون المسامي التركيب بطريقة التنميش بالليزر لكثافات تيار مختلفة، ﺷﺨﺼﺖ ﺧﺼﺎﺋﺺ العينات المحضرة ﺑﻮاﺳﻄﺔ ﻓﺤﺺ ﺣﯿﻮد اﻷﺷﻌﺔ اﻟﺴﯿﻨﯿﺔ، ﻣﺠﮭﺮ اﻟﻘﻮة اﻟﺬرﯾﺔ، ﺗﺤﻮﯾﻞ ﻓﻮرﯾﺮ للأﺷﻌﺔ ﺗﺤﺖ اﻟﺤﻤﺮاء حيث ان طبقات السيليكون المسامي تتكون على السطح حيث يتم تأينها بتيارات مختلفة (20, 30, 40, 50, 60 mA/cm2) لزمن تنميش .10 min من خلال فحص حيود الاشعة السينية يؤكد تكوين السيليكون المسامي وان الحجم البلوري يقل باتجاه الاحجام النانوية، ولوحظ ان القمة تزداد في العرض بزيادة تيار التنميش. من خلال مجهر القوة الذرية تبين ان عند التيارات الواطئة تبدأ طبقات السيليكون المسامي بالتكون وعند زيادة تيار التنميش سنحصل على اعرض قطر مسامي على السطح. من خلال تحويل فورير للأشعة تحت الحمراء تبين وجود أواصر كثيفة خاصة بالسيليكون حيث ان هذه الاواصر تكون قابلة للتأثر بالبيئة والهواء المحيط ويمكن ان تتأكسد باستمرار.


Article
Synthesis and Characterization of Au:CuO Nanocomposite by Laser Soldering on Porous Silicon for Photodetector

Authors: Juhaina Moatasemballah --- Halah H. Rashed
Journal: Al-Nahrain Journal of Science مجلة النهرين للعلوم ISSN: (print)26635453,(online)26635461 Year: 2017 Volume: 20 Issue: 2 Pages: 49-59
Publisher: Al-Nahrain University جامعة النهرين

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Abstract

This work aimed to the synthesize of composite Au:CuO (NPs) by pulsed laser soldering process. The optical properties, stability, structural properties and surface morphology of Au:CuO nanocomposite were characterized by UV–VIS spectrophotometer, Zeta potential measurement, X-Ray Diffraction pattern and Atomic Force Microscope respectively. The band gap of Au doped CuO is about 1.95 eV. The amount of zeta potential is -54 mV, its indicating that the negatively charged of Au: CuO nanocomposite in deionized water and the colloid is good stability against aggregation. Surface morphology of Au:CuO nanocomposite show a large number of particles have diameter about 55nm. Au: CuO nanocomposite deposited on porous silicon by drop casting technique for preparation of silicon photodetector, the electrical properties prove that band gap alignment between Au: CuO nanocomposite and PS facilitates the electron transfer and further increases the photoresponsitivity and Quantum efficiency.


Article
THE EFFECT OF POROSITY ON THE YIELD OF CARBON NANOTUBES

Authors: ahmad flayyih hussein --- aqeel ali al-attar
Journal: Al-Qadisiyah Journal for Engineering Sciences مجلة القادسية للعلوم الهندسية ISSN: 19984456 Year: 2017 Volume: 10 Issue: 2 Pages: 203-213
Publisher: Al-Qadisiyah University جامعة القادسية

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Abstract

In this work, the porous Magnesium alloy (AZ91 ) was prepared by Space holder technique to deposit carbon nanotubes, Novalac powder was used as space holding and fugitive materials with different particle size (≥20 µm, ≥500 µm) and amount (50, 52, 54, 56, 58, 60%wt.). Impact of Novalac powder (particle size and additive percent) on density and porosity of porous AZ91 alloy was studied. Fine Novalac powder (≥20 µm) not recommended in the porous AZ91 alloy preparation, concurrently coarse Novalac powder (≥500 µm) was suitable for that purpose. It was found that the density of AZ91 alloy decreased with increasing Novalac concentration. Carbon nanotubes were deposited on the porous AZ91 alloy by catalytic chemical vapor deposition whereas NiSO4.6H2O used as catalyst, acetylene gas as a carbon source and argon gas as a carrier gas with flow rate percent 1:1, at 575°C process temperature for 30 min. Multiwall carbon nanotubes were obtained and characterized by X-ray diffraction and scanning electron microscopy techniques. The average diameter of the multi wall carbon nanotubes was (46 nm). Although the porosity percent of AZ91 alloy was not majorly effect proportionally by the increasing of an additive Novalac percent, the yield (quantity) of Multiwall carbon nanotubes was enhancing due to increase the porous AZ91 alloy surface area.


Article
Analysis the Surface Morphology of the Porous Media by using Atomic Force Microscope technique
أستقصاء مورفولوجيا السطوح المسامية بوساطة استخدام مجهر القوة الذري

Author: Bashir Y. Sherhan Al-Zaidi بشير يوسف شرهان
Journal: Al-Khwarizmi Engineering Journal مجلة الخوارزمي الهندسية ISSN: 18181171 23120789 Year: 2017 Volume: 13 Issue: 4 Pages: 98-110
Publisher: Baghdad University جامعة بغداد

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Abstract

An atomic force microscope (AFM) technique is utilized to investigate the polystyrene (PS) impact upon the morphological properties of the outer as well as inner surface of poly vinyl chloride (PVC) porous fibers. Noticeable a new shape of the nodules at the outer and inner surfaces, namely "Crater nodules", has been observed. The fibers surface images have seen to be regular nodular texture at the skin of the inner and outer surfaces at low PS content. At PS content of 6 wt.%, the nodules structure was varied from Crater shape to stripe. While with increasing of PS content, the pore density reduces as a result of increasing the size of the pore at the fiber surface. Moreover, the test of 3D-AFM images shows that the roughness of both surfaces of fibers seems to be decreased with PS content. Alternatively, the fibers pure water permeability (PWP) has been declined with decreasing of fiber roughness.

يتعلق البحث بدراسة سطوح المواد المسامية وفحصها والتي تحتوي فتحات على سطحها تقود الى شبكة ذات ابعاد احادية او ثنائية او ثلاثية في داخل البناء الهيكلي لها وذلك باستخدام تقنية مجهر القوى الذري (AFM-technique). ان هذه التقنية تم استخدامها في البحث لدراسة تاثير محتوى البولي ستايرين على خواص السطوح الخارجية والداخلية لالياف البولي فنيل كلورايد المسامية عن طريق تغير مورفولوجيا السطح المسامي. وتم ملاحظة شكلاً لعقد مميز على السطوح الخارجية والداخلية عرفت علميا باسم: "Crater nodules". حيث ان صور الالياف المستنبطة من خلال مجهر القوة الذري اوضحت ان تركيب العقد على السطوح الداخلية والخارجية كان منتظما عند استخدام محتوى قليل من البولي ستايرين. وعند تركيز 6% من مادة البولي ستايرين تم ملاحظة تغير الشكل الهيكلي للعقد من "Crater" الى ."Stripe" ان زيادة محتوى البولي ستايرين ادى ايضا الى نقصان كثافة المسامات مع زيادة حجمهاعلى سطوح الالياف. الصور ثلاثية الابعاد لمجهر القوى الذري دلت كذلك على ان زيادة محتوى البولي ستايرين ادى الى نقصان خشونة السطوح الداخلية والخارجية لذلك فمعدل نفاذية الماء عبر الالياف قل مع نقصان خشونة السطوح.

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