• فهرست مقالات MSM

      • دسترسی آزاد مقاله

        1 - Impact of p-type semiconductor substrate on the transient response of metal-semiconductor-metal photodetector
        Ali Barkhordari Hamid Mashayekhi Şemsettin Altındal Süleyman Özçelik Yashar Azizian-Kalandaragh
        10.57647/j.jtap.2023.1701.08
        In this paper, using finite difference method, the effect of adding a p-layer at the back of a metal-semiconductor-metal (MSM) photodetector (PD) on the spatial electric charge distribution and the transient response of the device is numerically studied. To this aim, th چکیده کامل
        In this paper, using finite difference method, the effect of adding a p-layer at the back of a metal-semiconductor-metal (MSM) photodetector (PD) on the spatial electric charge distribution and the transient response of the device is numerically studied. To this aim, the fundamental equations of the semiconductor device, i.e., two current continuity time-dependent equations have been considered coupled with Poisson's equation. The I-V curve of the MSM photodetector is obtained as the main characteristics of each semiconductor device. Moreover, the variations of electrostatic potential, electron and hole concentrations are determined in the MSM photodetector with a p-layer at the back of the active layer. It is observed that the peak transient response of an MSM device is improved by back-gating the device as more electrons are injected to the semiconductor layer and the slower charge carriers (the holes) to be removed from the top circuit. پرونده مقاله
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        2 - Effect of doped Zn–PbI2 nanostructures on structural and electrical properties of photodetector applications
        Safaa Idan Mohammed Haider Mohammed Shanshool Khalil Ibraheem Imhan
        10.1007/s40094-019-00344-6
        AbstractThe present study focuses on the structural and electrical properties of doped zinc–lead iodide (Zn–PbI2) as-deposited film. Lead iodide (PbI2) nanostructure was successfully prepared by thermal evaporation method on a glass substrate at room temperature. The an چکیده کامل
        AbstractThe present study focuses on the structural and electrical properties of doped zinc–lead iodide (Zn–PbI2) as-deposited film. Lead iodide (PbI2) nanostructure was successfully prepared by thermal evaporation method on a glass substrate at room temperature. The analysis, characterization, and structural properties of PbI2 were achieved using X-ray diffraction (XRD) and scanning electron microscopy. The PbI2 was polycrystalline and had a hexagonal structure as proved using XRD. The measured values are in agreement with other experimental and theoretical data. Furthermore, the present research studied the effect of doping on the physical properties of lead iodide with zinc dopants at different weights (0.02, 0.04, 0.06, and 0.08) mg. The electrical properties of the fabricated metal–semiconductor–metal photodetector based on PbI2 and Pb1−xZnxI2 layers prepared on glass substrates by thermal evaporation method were investigated. The obtained results of Schottky barrier heights for Pb0.98Zn0.02I2 were significant. The current–voltage characteristics of the Pb0.98Zn0.02I2 thin film have acted as a Schottky contact in dark and under white light, 460-nm light. The light responsivity has shown a peak at 460-nm chopped light. At a bias voltage of 1, 3, and 5 V, the photocurrent rise and decay times were investigated. The device has shown faster response times for 460-nm light. This fast response was attributed to the high quality of polycrystalline and showed a high quantum efficiency of 9.19 × 102% when it was illuminated by 460-nm light under the bias of 3 V. پرونده مقاله
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        3 - بررسی تاثیر مشخصات لایه آلومینیومی بر عملکرد آشکارساز نوری MSM سیلیکنی
        مریم زارع پور حامد دهدشتی جهرمی
        آشکارساز نوری فلز-نیمه‌هادی-فلز از دو پیوند شاتکی و روزنه‌هایی برای جذب فوتون تشکیل شده و جریان تاریک کمی دارد. در این مقاله، به بررسی تاثیر مشخصات اتصال آلومینیومی بر جریان‌های تاریک و نوری و پاسخ نوری آشکارساز فلز- نیمه هادی-فلز (MSM) سیلیکنی پرداخته شده است. با توجه چکیده کامل
        آشکارساز نوری فلز-نیمه‌هادی-فلز از دو پیوند شاتکی و روزنه‌هایی برای جذب فوتون تشکیل شده و جریان تاریک کمی دارد. در این مقاله، به بررسی تاثیر مشخصات اتصال آلومینیومی بر جریان‌های تاریک و نوری و پاسخ نوری آشکارساز فلز- نیمه هادی-فلز (MSM) سیلیکنی پرداخته شده است. با توجه به روش رشد لایه فلزی، تابع کار یک فلز می‌تواند در یک بازه محدود تغییر کند. تاثیر تغییرات تابع کار آلومنیوم بر عملکرد آشکارساز مذکور مطالعه شده است. پس از تعیین تابع کار بهینه لایه فلزی، تاثیر ضخامت لایه آلومینیومی بر عملکرد آشکارساز بررسی شده است. نتایج به دست آمده نشان می‌دهد تابع کار و ضخامت لایه آلومینیوم تاثیر مستقیمی بر جریان تاریک، جریان نوری و پاسخ نوری قطعه دارد. تاثیر این دو مولفه بر پارامترهای آشکارساز نوری مذکور به نحوی است که می‌تواند ساختار را از حالت آشکارسازی خارج کرده و تبدیل به یک مقاومت الکتریکی نماید. بنابراین لازم است برای ساخت، با انتخاب روش لایه نشانی مناسب و ضخامت لایه فلزی مناسب، پارامترهای مذکور بهینه شوند. در این تحقیق برای یک آشکارساز نوری MSM با ساختار متقارن، تابع کار بهینه برابر با 26/4 الکترون ولت به دست آمد. توابع کار کمتر از این مقدار منجر به ایجاد اتصال اهمی بین لایه آلومینیومی و لایه سیلیکنی و توابع کار بیشتر از این مقدار منجر به ایجاد یک پیوند شاتکی با ولتاژ شکست بسیار کم در ناحیه بایاس معکوس می شود. همچنین بهترین ضخامت لایه آلومینیومی برابر با 1/1 میکرو-متر به دست آمد. این ضخامت منجر به بیشترین مقدار پاسخ نوری در آشکارساز مورد مطالعه می شود. پرونده مقاله
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        4 - Inter-Turn Fault Detection of PMSM Based on Fuzzy Logic and Discrete Wavelet Transform Using Unsupervised Clustering
        Vahid Khodashenas Limouni S.Asghar Gholamian Mehran Taghipour Gorjikolaie
        The idea of this paper is designing an automatic fault detection system based on fuzzy logic, therefore two signals of PMSM in fault condition are analyzed for inter turn fault detection: current and torque. In this fault type there is some distortion in these signals, چکیده کامل
        The idea of this paper is designing an automatic fault detection system based on fuzzy logic, therefore two signals of PMSM in fault condition are analyzed for inter turn fault detection: current and torque. In this fault type there is some distortion in these signals, but it is not good enough to detecting with fuzzy logic solely, so with combination of wavelet transform and FCM a new method for fault detection is introduced. In this method one detail signal of wavelet transform is chosen and then with FCM it is divided into 6 clusters, these clusters describe the situation of signal truly. Using FCM has two advantages: first in some clusters there had been fault therefore fault was detected, and second it is used for fuzzy logic system to deciding amount and intensity of fault of PMSM. By applying combination of wavelet transform and FCM, designing of fuzzy logic has been more effective, the MFs are directly come from output of FCM, therefore fuzzy logic system have more accurate answer. The output of fuzzy logic that is showed in surface view is based on tree situation that is defined in output MF, and describes whole conditions of PMSM and shows the amount of inter turn fault. پرونده مقاله
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        5 - Beyond The Covid-19 Global Pandemic: An Assessment of Agri-Food Related Micro, Small and Medium Enterprises’ Uptake of Insurance Covers
        Adeyemi Ayinde-Olawale Idowu Ogunyemi
        This study examined the impact of the global pandemic on level of production income and the uptake of insurance covers among agri-food related MSMEs’ in South West Nigeria. The study adopted treatment effects model, the logistic regression model, Pearson’s a چکیده کامل
        This study examined the impact of the global pandemic on level of production income and the uptake of insurance covers among agri-food related MSMEs’ in South West Nigeria. The study adopted treatment effects model, the logistic regression model, Pearson’s and Cramer’s V correlation coefficient to analyse the data for the study. Sampled households were selected through a snowballing sampling technique using the online survey method to arrive at 192 MSMEs from Urban South West region of Nigeria comprising of 132 controls and 60 treated MSME operators. The treatment variable for this study is the uptake of insurance cover. Analysis of the sample for the study showed that the uptake of insurance cover MSMEs’ in the study area stand at 31.25%.The result showed that MSMEs’ who were affected by the global pandemic are more likely to take up insurance cover to mitigate future risks than those who were not seriously affected. The result of the treatment effect models further revealed that the production income and MSMEs’ willingness to take insurance cover were both significantly impacted by the global pandemic. It was therefore recommended that insurance companies come up with tailor-made insurance products for MSMEs. Also, that flexible payments methods be allowed so that more micro enterprises can get cover which will in turn boost their confidence that in the event of an adverse market condition they will not be worse off. پرونده مقاله
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        6 - Optimal Design of an Axial Flux PMSM for Hybrid Vehicle Use
        Hamed Farnaghizad hamid lesani
        Increase of energy consumption and air pollution are big crises in recent two decades. Due to these crises and also increase of energy costs, utilization of hybrid electric vehicles becomes conventional and vehicle companies are increasing their investment in these kind چکیده کامل
        Increase of energy consumption and air pollution are big crises in recent two decades. Due to these crises and also increase of energy costs, utilization of hybrid electric vehicles becomes conventional and vehicle companies are increasing their investment in these kinds of vehicles. The main issue for these vehicles, besides energy storage system, is efficiency of electric motor and its weight and cost. Axial Flux Permanent Magnet Synchronous Motors (AFPMSM) have become popular for hybrid vehicles as they have better efficiency and less weight. In this paper an AFPMSM, which would be used in hybrid electric vehicles, is designed to get less weight and cost and more efficiency. PSO and GA algorithms have been applied in this design. Inner and outer diameter of axial flux permanent magnet motor and air gap flux density are taken as variables in the mentioned design. پرونده مقاله
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        7 - A NOVEL PM SHAPE for Reducing Cogging Torque in AFPMSM
        Hamed Farnaghizad Hamid Lesani
        Torque ripple in electrical machines is an important issue which may cause several problems in use. In permanent magnet machines and machines with DC excitation, main part of torque ripple is because of cogging torque. There are several ways to reduce this torque and in چکیده کامل
        Torque ripple in electrical machines is an important issue which may cause several problems in use. In permanent magnet machines and machines with DC excitation, main part of torque ripple is because of cogging torque. There are several ways to reduce this torque and in permanent magnet machines, optimized shape of permanent magnets is one of them. In this paper, a novel shape of permanent magnet in an Axial Flux Permanent Magnet Synchronous Machine (AFPMSM) is proposed which reduces the motor cogging torque and hence over come the torque ripple. First, reference motor is designed with conventional PM shape and then novel PM shaped AFPMSM is designed. These two machines are analyzed by MAXWELL software and then their torque ripples are computed. Results show 35 percent reduction of cogging torque. پرونده مقاله
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        8 - بررسی بازده در شرکت سرمایه‌گذاری با سه روش مارکو سویچینگ، بازده متقارن و نامتقارن
        فاطمه صمدی فریدون رهنمای رودپشتی هاشم نیکومرام
        برای بیش از چند دهه تئوری مالی مدرن به عنوان تنها واصلی ترین دیدگاه در بازار سرمایه مبنای اکثر تحقیقات قرار داشته است.ولی وجود بحران های ایجاد شده در دهه های گذشته در اکثر کشورها وهمچنین تحقیقات انجام شده به نظر می رسدکه بسیاری شکست هادر بازارهای مالی ناشی از همین تئوری چکیده کامل
        برای بیش از چند دهه تئوری مالی مدرن به عنوان تنها واصلی ترین دیدگاه در بازار سرمایه مبنای اکثر تحقیقات قرار داشته است.ولی وجود بحران های ایجاد شده در دهه های گذشته در اکثر کشورها وهمچنین تحقیقات انجام شده به نظر می رسدکه بسیاری شکست هادر بازارهای مالی ناشی از همین تئوری های مدرن وفرضیات سنتی دربازارها می باشد.بنابراین نیاز به بازنگری دراین تئوری هاوفرضیات به شدت احساس می شود. این دیدگاه نوین که با توجه به تئوری آشوب و علم فر کتال،ایده های نئوکلاسیک را دگرگون گرده وروش ها وواژه های کافی برای توصیف بازار های سرمایه به ما می دهند.در این تحقیق به دنبال بررسی بازده با روش های بازار متقارن ؛نامتقارن ومارکوسویچینگ می باشیم. پرونده مقاله

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