رزونانس

Open Access Article

1 - Infant Brain Image Segmentation using the Convolutional Neural Networks
Iran Sarafraz Hamed Agahi2 Azar Mahmoodzadeh

In this paper, a method based on convolutional neural networks for segmenting neonatal brain images is presented. One of the major challenges in neonatal brain image segmentation is the intensity distribution overlapping between gray matter and white matter tissues, whi More

In this paper, a method based on convolutional neural networks for segmenting neonatal brain images is presented. One of the major challenges in neonatal brain image segmentation is the intensity distribution overlapping between gray matter and white matter tissues, which reduces the segmentation accuracy of these areas. To increase the intensity differentiation between brain tissues, this paper presents a pre-processing method based on convolutional neural networks that effectively increases the segmentation accuracy. To obtain the final segmentation result, another convolutional neural network is proposed which performs segmentation based on T1-T2 images. To evaluate the performance of the proposed method, two databases are used, which include magnetic resonance imaging of infants' brains. The results show the appropriate efficiency of the proposed method in segmenting brain tissues. Manuscript profile

Open Access Article

2 - Designing Competitive Nanobiosensor for Ochratoxin based on FRET using quantum dot
Mozaffari, M., Bayat, M., Mohsenifar, A., Hashemi, S.J. .

In this research, using FRET (fluorescence resonance energy transfer) from Cd/Te quantum dot (anti Ochratoxin A antibody immobilized on the external surface of quantum dot or QDs) to (Ochratoxin A labeled with Rhodamine 123 bound to albumin), a sensitive competitive imm More

In this research, using FRET (fluorescence resonance energy transfer) from Cd/Te quantum dot (anti Ochratoxin A antibody immobilized on the external surface of quantum dot or QDs) to (Ochratoxin A labeled with Rhodamine 123 bound to albumin), a sensitive competitive immunoassay was developed for measuring Ochratoxin A. The highly specific immune-reaction between anti-Ochratoxin A antibody on the QDs and labeled Ochratoxin A brings the Rho fluorophore and the QDs in close spatial proximity, and following photo-excitation of the QDs, causes FRET to occur between the Rho fluorophore (acting as the acceptor) and the QDs (acting as the donor). In the absence of free Ochratoxin A, the immune reaction between labeled Ochratoxin and the anti-Ochratoxin antibody on the QDs induces emission and causes FRET to occur. In the presence of free Ochratoxin A, it competes with the labeled Ochratoxin A-albumin complex for binding to the antibody-QDs conjugate in the Nanobiosensor, leading to reduction in Rhodamine emission after FRET. The reduction in the fluorescence intensity of the Rhodamine acceptor directly correlates with the concentration of free Ochratoxin A in the sample. This method has a detection limit of 220pg per ml. It has also been used to measure Ochratoxin A in human serum samples. A linear relationship is found between the increase in the fluorescence intensity of Rho 123 at580 nm and the concentration of OTA in spiked samples over the 100-800 pg⋅mL−1 concentration range. This highly sensitive homogeneous competitive detection scheme is simple, rapid and efficient. It does not require multiple separation steps and excessive washing. Manuscript profile

Open Access Article

3 - Numerical analysis of energy harvesting from an airfoil under concurrent base and flow excitations with nonlinear modeling
Seyed Mostafa Mirtabaei Ali Kargozarfard

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Open Access Article

4 - A Triple-Buck Converter with Zero-Voltage Transition Base on the Interleaved Inductors
Yasin Bastan Ali Nejati Parviz Amiri

A triple-buck converter with zero voltage transient is presented in this paper. The proposed structure is formed by three parallel buck converter to increase the reliability which is utilized three interleaved inductors for connecting the stages to reduce the losses cau More

A triple-buck converter with zero voltage transient is presented in this paper. The proposed structure is formed by three parallel buck converter to increase the reliability which is utilized three interleaved inductors for connecting the stages to reduce the losses caused by hard switching. The zero voltage transistor is also performed by resonance between the parasitic capacitance of the power switches and the equivalent inductor seen from each capacitor. The proposed circuit analysis has been performed in different operating modes. The proposed Buck converter is simulated in the Matlab/Simulink environment. The simulation results prove that the switching losses as well as the loss of diodes can be reduced by zero voltage switching of the power switches and designed high-performance converter. The simulation results show that the output reaches its final value of 40 V after 0.6 ms and the output voltage variations is 0.5 V the output ripple is achieved 1.25%. Manuscript profile

Open Access Article

5 - Electromagnetic Force Analysis of Transformer on the Ferroresonance due to Consecutive 3–Phase Short–Circuit Faults Using Finite Element Method (FEM)
Ali Ahmadpour SeyedJalal Seyed Shenava Abdolmajid Dejamkhooy Elham Mokaramian

In this paper, Finite Element Method (FEM) is used to study the ferroresonance phenomenon from the perspective of the electromagnetic forces introduced on the transformer windings. In order to simulate this phenomenon, a consecutive 3–phase short–circuit fau More

In this paper, Finite Element Method (FEM) is used to study the ferroresonance phenomenon from the perspective of the electromagnetic forces introduced on the transformer windings. In order to simulate this phenomenon, a consecutive 3–phase short–circuit fault is considered to be on the primary side at a relatively distant from the transformer. Then, due to the capacitance of the line, between the error point and transformer, the single–phase short–circuit faults are generated, one–by–one. Because of the switching, for isolation feeder from the fault point, the ferroresonance appears in power system. Then, voltages and currents of the primary and secondary windings will be changed. The effect of current changes on the forces that transformer coils withstand, when the ferroresonance happens, is an interesting topic to this paper. With modeling of the transformer and feeder switching in the FLUX 12.2 software, the ferroresonance condition is simulated. Due to the dependence of the ferroresonance on the non-linearity of the magnetic characteristic of the transformer core, Jiles–Atherton vector hysteresis model is used to modeling the core hysteresis loops for enhancement the results accurate.  Manuscript profile

Open Access Article

6 - Overview of DC-DC Non-Insulated Boost Converters (Structure and Improvement of Main Parameters)
Omid Sharifiyana Majid Dehghani Ghazanfar Shahgholian Sayyed Mohamad Mehdi Mirtalaee Masoud Jabbari

Abstract: The production of clean electricity is one of the most basic human needs today. Therefore, the use of power plants that use renewable and environmentally friendly fuels (new energy) as their base fuel, has been highly appreciated. However, the output voltage l More

Abstract: The production of clean electricity is one of the most basic human needs today. Therefore, the use of power plants that use renewable and environmentally friendly fuels (new energy) as their base fuel, has been highly appreciated. However, the output voltage level of local power plants based on new energies is as low as the input voltage of the next floors (inverters, etc.). Therefore, researchers have tried to solve this defect by using DC / DC boost converters. The structures related to these converters are different based on the designer's expectations such as voltage gain, output power, efficiency, input voltage specifications, etc. Boost converters are responsible for increasing the DC voltage by switching and storing energy in their inductor. But the same simple structure can be created with the help of new tricks such as using magnetic coupling, adding passive incremental circuits to the converter structure, creating more complete structures by using several active switches and even combining several structures together to the desired point in terms of voltage gain. On the other hand, with soft switching methods (resonance, snubber, etc.), the efficiency of boost converters is in the acceptable range. In this paper, the types of power plants based on new energy and then boost converters, which are the most basic elements of a power plant based on new energy, it is categorized in terms of incremental structures and applied methods for optimizing these converters, especially in terms of reducing losses and increasing efficiency. Manuscript profile

Open Access Article

7 - Modeling of Pulsed Transformer with Nanocrystalline Cores
Amir Baktash Abolfazl Vahedi

Recently tape wound cores, due to their excellent properties, are widely used in transformers for pulsed or high frequency applications. The spiral structure of these cores affects the flux distribution inside the core and causes complication of the magnetic analysis an More

Recently tape wound cores, due to their excellent properties, are widely used in transformers for pulsed or high frequency applications. The spiral structure of these cores affects the flux distribution inside the core and causes complication of the magnetic analysis and consequently the circuit analysis. In this paper, a model based on reluctance networks method is used to analyze the magnetic flux in toroidal wound cores and losses calculation. A Preisach based hysteresis model is included in the model to consider the nonlinear characteristic of the core. Magnetic losses are calculated by having the flux density in different points of the core and using the hysteresis model. A transformer for using in a series resonant converter is modeled and implemented. The modeling results are compared with experimental measurements and FEM results to evaluate the validity of the model. Comparisons show the accuracy of the model besides its simplicity and fast convergence. Manuscript profile

Open Access Article

8 - Design and Implementation of a New Current Fed Converter With Zero Current Switching Conditions
Bahador Fani Majid Delshad

In this paper a new soft switching current-fed converter for high voltage high power applications is presented. This converter utilizes parasitic components of high voltage transformers as resonant elements and employs fixed frequency phase shift PWM control to implemen More

In this paper a new soft switching current-fed converter for high voltage high power applications is presented. This converter utilizes parasitic components of high voltage transformers as resonant elements and employs fixed frequency phase shift PWM control to implement soft switching condition, so the implementation of control circuit is easy and cheap. Every six switches turn on at zero current condition (ZCS) and it has high efficiency. The detailed steady state analysis of the converter is presented by computer simulation and analytical method. Finally the experimental results certificate analysis and simulation results of this converter. Manuscript profile

Open Access Article

9 - Design and Implementation of Half-Bridge LLC Resonant Converter by FHA Technique
Navid Salehi Majid Dehghani

Although in existence for many years, only recently has the LLC resonant converters, in particular in its half-bridge implementation, gained in the popularity it certainly deserve. The advantages such as high efficiency, low level of EMI emissions, and its ability to ac More

Although in existence for many years, only recently has the LLC resonant converters, in particular in its half-bridge implementation, gained in the popularity it certainly deserve. The advantages such as high efficiency, low level of EMI emissions, and its ability to achieve high power density are such features that suited for power supply demand of many modern applications such as ATX PCs and flat panel TVs. One of the major difficulties in concern with designing such converter is complex model and non-linear equations that cannot be easily used into a design procedure. So in this paper, design is based on the assumption that input-to-output power transfer is essentially due to the fundamental Fourier series components of currents and voltages. This technique known as First Harmonic Approximation (FHA) and is a proper method to obtain the voltage gain through solving the equivalent ac circuit of the resonant tank. The design simulated by Pspice and finally the experimental results show design procedure base on FHA technique. Manuscript profile

Open Access Article

10 - Steady State Analysis of LCLC Resonant Converter with Capacitive Output Filter
Navid Shafiyi Hosein Farzanehfard Mehrdad Jafarboland

This paper presents the mathematical analysis and modeling of a 4th order LCLC resonant converter with capacitive output filter in steady-state condition. Due to the nonlinearity of the LCLC resonant circuit with capacitive output filter, the conventional modeling proce More

This paper presents the mathematical analysis and modeling of a 4th order LCLC resonant converter with capacitive output filter in steady-state condition. Due to the nonlinearity of the LCLC resonant circuit with capacitive output filter, the conventional modeling procedure cannot thoroughly describe the behavior of the converter. In this paper, a mathematical model is proposed that can accommodate the absence of the output inductor and predict the converter performance for a wide range of operating conditions. A 2.25KW prototype converter is provided to evaluate the accuracy of the proposed model. Experimental results show that the proposed model can precisely predict the behavior of the converter for a wide range of operating conditions. Manuscript profile

Open Access Article

11 - Biosynthesis and characterization of silver nanoparticles using aqueous extract of walnut (Juglans regia L.) leaf
masoud bayat reza moradi ali bodaghi

10.30495/jacr.2022.691780

Green synthesis of nanoparticles is an environmentally friendly method, in which water solvent are used. In this study, the biosynthesis of silver nanoparticles (Ag-NPs) was performed by using walnut (Juglans regia L.) leaf extract. Walnut leaf contains a variety of che More

Green synthesis of nanoparticles is an environmentally friendly method, in which water solvent are used. In this study, the biosynthesis of silver nanoparticles (Ag-NPs) was performed by using walnut (Juglans regia L.) leaf extract. Walnut leaf contains a variety of chemicals, including tannins, flavonoids, vitamins, plant acids and naphthoquinone. The extract of walnut (Juglans regia L.) leaf as the reducing agent is used for the synthesis of silver nanoparticles. The silver nanoparticles have been characterized by scanning electron microscopy (SEM), Energy dispersive X-ray (EDAX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and UV-Visible spectroscopy. UV-Vis spectrum exhibit an absorption band at around 400-450 nm suggestion the formation of silver nanoparticles. The observed peak at about 425 nm is related to the surface plasmon resonance of silver nanoparticles. The effects of operational parameters in the synthesis of silver nanoparticles such as silver nitrate salt concentration, extract volume, temperature and time was studied. The results showed that silver nitrate concentration 6 mM, extract volume 200 µlit, temperature 90°C and time 40 min was the optimum amounts. Manuscript profile

Open Access Article

12 - بررسی برخی از کمپلکس‌های جدید گازهای نجیب به عنوان اکسنده با نظریه‌ی AIM و NMR
محمدحسین قربانی آرش قورچیان

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Open Access Article

13 - تحلیل ارتعاشات غیرخطی تیر اویلر برنولی بر روی بستر الاستیک غیرخطی تحت تأثیر بار محوری فشاری
احمد مامندی محمدحسین کارگرنوین

در این مقاله، ارتعاشات تیر اویلر- برنولی با در نظر گرفتن بستر الاستیک غیرخطی، بررسی شده است. تیر تحت بارگذاری محوری فشاری بوده و شرایط تکیهگاهی، مفصلی- غلطکی میباشد. تحلیل ارتعاشات بر اساس مدهای نرمال غیرخطی در وضعیت رزونانس داخلی سه به یک (3:1) انجام می‌گیرد. More

در این مقاله، ارتعاشات تیر اویلر- برنولی با در نظر گرفتن بستر الاستیک غیرخطی، بررسی شده است. تیر تحت بارگذاری محوری فشاری بوده و شرایط تکیهگاهی، مفصلی- غلطکی میباشد. تحلیل ارتعاشات بر اساس مدهای نرمال غیرخطی در وضعیت رزونانس داخلی سه به یک (3:1) انجام می‌گیرد. معادلهی دیفرانسیلی غیرخطی حاکم بر ارتعاشات عرضی تیر استخراج شده‌ و به کمک روش چند مقیاس زمانی، تحلیل شده است. در وضعیت رزونانس داخلی 3:1 بر اساس مدهای نرمال غیرخطی در حالت پایا، پایداری پاسخ فرکانسی ارتعاشات غیرخطی تیر مطالعه شده، سپس تأثیر تغییر پارامترهای مختلف بر روی نتایج تحلیل دینامیکی و تحلیل پایداری پاسخ فرکانسی ارتعاشات غیرخطی تیر بررسی شده‌است. Manuscript profile

Open Access Article

14 - Morphic Field Theory in Language Learning
Rozita Zabihi Hasan Ahadi

Abstract: The aim of this study was to investigate the "morphic field", using language skill as a sample of various skills which people try to learn. The research method was casual-comparative. Three hundred female and male students from Islamic Azad University, South T More

Abstract: The aim of this study was to investigate the "morphic field", using language skill as a sample of various skills which people try to learn. The research method was casual-comparative. Three hundred female and male students from Islamic Azad University, South Tehran branch have been selected by cluster sampling method. They were all studying in humanities except foreign languages. By using Power point software twenty correct and twenty incorrect Swahili pair words slides displayed for them about 10 seconds. Participants selected and wrote any word they thought they were correct. Internal consistency of these words by Cranach Alpha was 0.84 and its test-retest reliability was 0.87. The results of "binominal test" indicated that participants in % 50 of cases selected 13 words out of 20 correct words. Also, they selected the correct words in %56.25 of the cases. Furthermore, there is significant difference between selection of correct and incorrect words of Swahili language. In addition, there isn’t any significant difference between female and male in selection of correct and incorrect Swahili words. These findings consist with those studies that study Chinese and Russian languages in other countries. Thus, the "Morphic Field" theory is valuable in facilitating learning among the members of one species. Manuscript profile

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