Physical Properties of (Basalt-Ni) System by Thermal Spray Flame Technique

       تعاني العديد من السطوح تشققات وتأكل خارجي مثل الريش التوربينية وانابيب النفط ولأجل حل تلك المشاكل يتم استخدام طلاءات ذات متانة عالية وكلفة واطئة. ففي البحث الحالي تم استخدام مسحوق صخور البازلت((Basalt ذات الاكاسيد المتعددة مدعمة بمادة معدنية (Ni)50% تم رش النماذج المجهزة بتقنية الرش الحراري بواسطة اللهب وعند مسافات رش متعددة هيcm  (10,12,14,16,18,20) وبعد اكمال تحضير النماذج المطلية على قاعدة من الفولاذ السبائكي تم اجراء عملية التلبيد للعينات وعند معاملة ((700℃, 900℃,1100℃ وبزمن ساعتين. اما الفحوص الميكانيكية تمثلت ب( قوة التلاصق, المسامية, الصلادة, البلى) وكما تم اجراء فحص بالمجهر الالكتروني الماسح(SEM) للعينات المحضرة قبل وبعد عملية التلبيد. اظهرت نتائج الفحص ان احسن مسافة رش كانت cm 16 وافضل معاملة حرارية هي ( (1100℃ وذلك بالاعتماد على كل من نتائج فحوص قوة التلاصق التي بلغتMPa(24.43) و المسامية التي بلغت %((8.653 وصلادة فيكرز هي (HV 1140) وكما ووجد عند سرعة انزلاقية ثابتة هي (cm/min.12000) وعند زمن خمسة دقائق وحمل ( (20Nالحصول على اوطئ معدل بلى(wear)هو (0.397), اما نتائج فحص المجهر الالكتروني الماسح اوضحت تناسق سطحي واضح بعد اجراء المعاملات الحرارية مع وجود قليل للمسامات وعند افضل معاملة حرارية هي ( (1100℃.Many surfaces suffer cracks and external corrosion such as turbo blades and oil pipes. In order to solve these problems are used coatings of high durability and low cost. In the current research, the power of the basalt with multiple oxides supported by metal (Ni) 50% was sprayed models with thermal spraying by flame and at multiple spraying distances of (10,12,14,16,18,20) cm after the preparation of the models coated on a base of alloy steel, the process of sintering of the samples at (700, 900, 1100) ℃ and within two hours have been done. The mechanical tests were (strength adhesion, porosity, hardness, wear, and tear) (SEM) for prepared samples before and after sintering. The results showed that the best spraying distance was 16 cm and the best heat treatment is ( (1100 ℃), depending on the results of the adhesion strength tests at (24.43 MPa) and (8.653%) porosity, (1140 Hv) and the hardness of the Vickers and at a constant sliding speed (12000 cm/min). The results of the scanning electron microscopy showed clear surface consistency after thermal conductivity with a few pores and treatments the best (1100.)

Performance comparison of different control strategies for the regulation of DC-DC negative output super-lift luo-converter

In last years, dc-dc converters solve the most issues in the industrial application in the area of power electronics, especially renewable energy, military applications and affiliated engineering developments. They are used to convert the DC input that unregulated to regulated output perhaps larger or smaller than input according to the type of converters. This paper presents three primary control method used for negative output Super lift Luo DC-DC converter. These methods include a Voltage mode control (VMC), Current mode control (CMC), and Sliding mode control (SMC). The goal of this article is to study and selected an appropriate and superior control scheme for negative DC-DC converters. The simulation results show the effectiveness of Sliding mode control for enhancing the performance of the negative dc-dc converter. Also, this method can keep the output voltage constant under load conditions. simulation results obtained by the MATLAB/Simulink environment

Sedimentological and diagenetic study of the Early Middle Miocene Jeribe Limestone Formation in selected wells from Iraq northern oilfields (Ajil; Hamrin; Jadid; Khashab)

Five subsurface sections covering the entire length of the Jeribe Limestone Formation (Early Middle Miocene) were studied from four oilfields in northern Iraq. It is hoped to unravel this formation microfacies ; depositional environment; diagenetic attributes and their parental processes; and the relationship between these processes and the observed porosity patterns. The microfacies were found to include mudstone, wackestone, packstone, and grainstone, which have been deposited respectively in open platform, restricted platform, and edge platform which represent the lagoonal environment, while the deposits of the lower parts of the Jeribe formation especially in well Hamrin- 2 reflect a deeper fore slope environment. By using the lithofacies association concepts, the depositional model of the Jeribe Formation was built. From a reservoir point of view, the formation suffered from two groups of diagenetic processes. The first one includes the porosity destructive ones such as cementation; compaction; mechanical degradation; anhydritization; and silicification. The second group include porosity enhancers ones which to include dissolution; and dolomitization

Protection of Galvanized steel from corrosion in salt media using sulfur nanoparticles

تم دراسة خصائص الكبريت النانوي بوساطة  جهاز مجهر القوة الذري. أظهرت قياسات مجهر القوة الذرية الحجم الكلي للكبريت النانوي المحضر بوساطة مزج ثايوسلفات الصوديوم مع مستخلص نبات  اليقطين مساويا 93.62نانومتر .تم دراسة حماية التاكل لمعدن الكلفانك ستيل  في الوسط الملحي وبمختلف درجات الحرارة بوساطة الكبريت النانوي وتم الحصول على افضل نتائج ثرموديناميكية  للمعدن بوجود الكبريت النانوي حيث كفاءة التثبيط ومقاومة لتاكل للمعدن تعطي اعلى قيمة عند اعلى درجة حرارية بوجود المثبط بلمقارنة بغيابة .كذلك سرعة التاكل تقل عند زيادة درجة الحرارة بوجود الكبريت النانوي, القيم الموجة للدالة الحرارية بوجود وبعدم وجود الكبريت النانوي تدل على انه التفاعل ماص للحرارة . لذا يقترح ان الكبريت النانوي مثبط جيد لمعدن الكالفانك ستيل في الوسط الملحي                The characteristics of sulfur nanoparticles were studied by using atomic force microscope (AFM) analysis. The atomic force microscope (AFM) measurements showed that the average size of sulfur nanoparticles synthesized using thiosulfate sodium solution through the extract of cucurbita pepo extra was 93.62 nm. Protecting galvanized steel from corrosion in salt media was achieved by using sulfur nanoparticles in different temperatures. The obtained data of thermodynamic in the presence of sulfur nanoparticles referred to high value as compares to counterpart in the absence of sulfur nanoparticles, the high inhibition efficiency (%IE) and corrosion resistance were at high temperature, the corrosion rate or weight loss decreased with increasing temperature in the presence of sulfur nanoparticles. The positive value of enthalpy ∆H* for galvanized steel with and without sulfur nanoparticles indicates that the reaction was endothermic. Therefore, the sulfur nanoparticles can be suggested as good inhibitor for galvanization in salt media

The Role of Green Intellectual Capital in Strengthening the Elements of the Knowledge Economy: An Analytical Descriptive Study of the Opinions of a Sample of Managers in the Oil Products Distribution Company /Iraq- Nineveh

The current research sought to identify the role of the dimensions of green intellectual capital in strengthening the elements of the knowledge economy, by determining the level of the relationship and the impact between them and applying it on the Oil Products Distribution Company in Nineveh, the sample of study was selected intentionally. It consists of (100) managers, as it relies on collecting data and information on the main research tool (questionnaire form), a number of statistical tools have been adopted, namely (correlation coefficient, linear regression). Where many conclusions were presented, the most important of which is indicating a case of the actual contribution of the dimensions of green intellectual capital in strengthening the elements of the knowledge economy in the researched organization. It also made a set of proposals, including the need for more attention to be paid to employing the possibilities and capabilities of green intellectual capital (human, structural, social) towards strengthening the elements of the knowledge economy in the researched organization, in a way that, it contributes to enhancing efforts in support of knowledge economies and achieving added value in all directions

Performance Analysis of MEMS Based Oscillator for High Frequency Wireless Communication Systems

The frequency oscillator is a basic component found in many electrical, electronic, and communications circuits and systems. Oscillators come in a variety of shapes and sizes, depending on the frequency range employed in a given application. Some applications need oscillators that generate low frequencies and other applications need oscillators that generate extremely high and high frequencies. As a result of the expansion and speed of modern technologies, new oscillators appeared that operating at extremely high frequencies. Most wireless communication systems are constrained in their performance by the accuracy and stability of the reference frequency. Because of its compatibility with silicon, micro-electro-mechanical system (MEMS) is the preferred technology for circuit integration and power reduction. MEMS are a rapidly evolving area of advanced microelectronics. The integration of electrical and mechanical components at the micro size is referred to as a MEMS. MEMS based oscillators have demonstrated tremendous high frequency application potential in recent years. This is owing to their great characteristics such as small size, integration of CMOS IC technology, high frequency-quality factor product, low power consumption, and cheap batch manufacturing cost. This paper's primary objective is to describe the performance of MEMS oscillator technology in high-frequency applications, as well as to discuss the challenges of developing a new MEMS oscillator capable of operating at gigahertz frequencies

Silicon grain boundary passivation for photovoltaics: a novel approach with small polar molecules

Grain boundaries (GBs) play a major role in determining the device performance of in particular polycrystalline thin film solar cells including Si, CdTe and CIGS. Hydrogen passivation has been traditionally applied to passivate the defects at GBs. However, hydrogenated films such as amorphous silicon (a-Si:H) and microcrystalline silicon (c-Si:H) are subject to light-induced degradation effects. In this study on multicrystalline (mc)-Si wafers, we found an excellent correlation between the grain misorientation and the corresponding electrical resistivity across grain boundaries. In particular, the charge transport across GBs was greatly enhanced after the wafers were properly treated in our polar molecule solutions. The results were explained to be due to the more effective charge neutralization and passivation of polar molecules on localized charges at GBs. These findings may help us achieve high-quality materials at low cost for high-efficiency solar cells by improving the carrier transport and minimizing the carrier recombination. We also believe that this study will help us with a deeper understanding on GBs and their behaviors for the applications not only in photovoltaics, but also in other solid-state devices such as thin-film transistors. © 2012 IEEE.published_or_final_versionThe 38th IEEE Photovoltaic Specialists Conference (PVSC), Austin Cenvention Centre, Austin, Texas, USA, 3-8 June 2012. In Conference Record, 2012, p. 001144 - 00114