A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters

Monfared, Mohammad,Golestan, Saeed,Guerrero, Josep M. The Korean Institute of Power Electronics 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.4

This paper discusses the design of a novel synchronous reference frame (SRF) method that can extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous SRF studies, the proposed method has an innovative feature that does not require a fictitious current signal. Other key features of the proposed strategy include frequency-independent operation, accurate reference current extraction, and relatively fast transient response. The effectiveness of the proposed method is investigated by conducting a detailed mathematical analysis. Results of the analysis confirm the superior performance of the suggested approach. Theoretical evaluations are confirmed by the experimental results.

A Review Study for Creep in Different Nanocomposites

Vahid Monfared,Hamid Reza Bakhsheshi‑Rad,Mahmood Razzaghi,D. Toghraie,Maboud Hekmatifar,Filippo Berto 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.9

This article presents a brief review regarding the creep behavior (CB) of the nanocomposites (NCs)-based materials in recentyears. The creep (C) in solids under high stress (HS) and temperature (T) is one of the processes of interest to researchersin the industry. Investigating the time-dependent plastic deformation (PD) of NCs is vital in modern sciences. The C studywould be crucial for elevated T and high stresses applications. (e.g., turbine blades, spaceships, shuttles, and nozzle guidevanes). In addition, a comparatively detailed review of the C of metal-based NCs, particularly magnesium (Mg) based ones,has been presented. Mg and its alloys have recently fascinated much interest in replacing existing structural materials invarious applications because of their outstanding properties like good damping capability, high specific strength, and goodmachinability. However, their use is limited because of their low Creep resistance at high Ts. Encapsulation of nanoparticles(NPs) is one efficient way to better the creep resistance of Mg-based NCs. Movement of dislocation can be hindered by NPs,which act as barriers to dislocations.

Development of carboxymethyl cellulose/chitosan double-layer hydrogel combining myrtle essential oil and thyme honey to enhance antibacterial and mechanical properties

Reza Monfared-Hajishirkiaee,Hamide Ehtesabi,Ali Rezaei,Shima Najafinobar 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.126 No.-

Bacterial infection and oxidative stress are still mentioned as critical problems for wound treatmentbecause they often cause delays in wound healing. Creating a suitable environment in the wound bedcan speed up its regeneration process. The aim of this study was to fabricate and characterize doublelayerhydrogels based on the biopolymers carboxymethyl cellulose (CMC) as the first layer and chitosanas the second layer for use as wound dressings. In the second layer of this hydrogel, thyme honey as acarbohydrate compound and myrtle essential oil (MEO) as an herbal combination were added in orderto create antimicrobial and mechanical properties. The creation of a double-layer hydrogel and the presenceof thyme honey and MEO were confirmed by microscopy. An analysis of the structure of the hydrogelshowed its flexibility and excellent mechanical strength. The effects of the MEO and honeycomponents in the double-layer hydrogel resulted in the development of enhanced antibacterial activityand potent antioxidant characteristics. Also, these double-layer hydrogels were evaluated in terms of thein vivo healing process and showed excellent therapeutic performance. In general, these valuable propertiesof double-layer hydrogels make them a promising candidate for wound dressing application.

Novel mathematical approaches for analyzing time dependent creep deformations in reinforced metals

Vahid Monfared,Mehdi Mondali,Ali Abedian 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.11

The objective of this paper is to present some novel insights for solving a second stage creep problem in metal matrix composites. First, a new analytical approach is developed for obtaining some unknowns in second stage creep of short fiber composites under an applied axial load. The unknowns are the radial, circumferential, axial, shear and equivalent stresses, which are determined by approximation of creep constitutive equations and using proper assumed displacement rates. A nonlinear differential equation is solved employing suitable and correct approximate assumptions. Then, the difference of the stress components utilizing creep constitutive equations and assumed displacement rates is determined. Finally, the axial stress behavior in matrix is predicted by linear and nonlinear boundary value approaches, as well as displacement rates in matrix. For the purpose of the analysis, the steady state creep behavior of matrix material is described by an exponential law. As an important application, factor of safety n will be determined for fibers in order to have a good composite design. Based on the results, the aforementioned methods such as general boundary value approaches can be used to simply determine the approximate behavior of unknowns. These analytical results are then verified by the results of FEM simulation and other available research works. Interestingly, good compatibilities are found among the original mathematical approaches, numerical modeling and also previous available results.

Science and Technology of Additive Manufacturing Progress: Processes, Materials, and Applications

Vahid Monfared,Seeram Ramakrishna,Navid Nasajpour‑Esfahani,Davood Toghraie,Maboud Hekmatifar,Sadegh Rahmati 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.12

As a special review article, several significant and applied results in 3D printing and additive manufacturing (AM) scienceand technology are reviewed and studied. Which, the reviewed research works were published in 2020. Then, we wouldhave another review article for 2021 and 2022. The main purpose is to collect new and applied research results as a usefulpackage for researchers. Nowadays, AM is an extremely discussed topic and subject in scientific and industrial societies, aswell as a new vision of the unknown modern world. Also, the future of AM materials is toward fundamental changes. Which,AM would be an ongoing new industrial revolution in the digital world. With parallel methods and similar technologies,considerable developments have been made in 4D in recent years. AM as a tool is related to the 4th industrial revolution. So,AM and 3D printing are moving towards the fifth industrial revolution. In addition, a study on AM is vital for generating thenext developments, which are beneficial for human beings and life. Thus, this article presents the brief, updated, and appliedmethods and results published in 2020.

A New Synchronous Reference Frame-Based Method for Single-Phase Shunt Active Power Filters

Mohammad Monfared,Saeed Golestan,Josep M. Guerrero 전력전자학회 2013 JOURNAL OF POWER ELECTRONICS Vol.13 No.4

This paper discusses the design of a novel synchronous reference frame (SRF) method that can extract the reference compensating current for single-phase shunt active power filters (APFs). Unlike previous SRF studies, the proposed method has an innovative feature that does not require a fictitious current signal. Other key features of the proposed strategy include frequency-independent operation, accurate reference current extraction, and relatively fast transient response. The effectiveness of the proposed method is investigated by conducting a detailed mathematical analysis. Results of the analysis confirm the superior performance of the suggested approach. Theoretical evaluations are confirmed by the experimental results.

Effects of Sowing Date and Chitosan on Some Characters of Canola (Brassica napus L.) Genotypes

Banafsheh Beheshti Monfared,Ghorban Noormohamadi,Amir Hossein Shirani Rad,Eslam Majidi Hervan 한국작물학회 2020 Journal of crop science and biotechnology Vol.23 No.1

Changes in the environment that are associated with different sowing dates can be expected to alter canola (Brassica napus L.) growth and development. The objective of this work was to study the effect of sowing date and chitosan on some characters of canola genotypes. Five genotypes (RGS003, Sarigol, Zafar, Dalgan, and Julius) were sown in three sowing dates (October 7, 17, and 27), for two years (2014-2015 and 2015-2016). A factorial split-plot experiment was conducted in a complete randomized blocks design with three replications, where the sowing dates and the two levels of chitosan (0 [control] and 0.2% concentrations) were allotted to main plots and the genotypes were allotted to subplots. The ANOVA revealed that the main effects of sowing date, chitosan and genotype were significant for almost all measured characters. In addition, the interaction effect of sowing date and genotype was significant for plant height, number of silique in shoots, number of seeds per main silique, 1000-seed weight and oil yield. The seed and oil yields in the third sowing date were reduced by 0.46 and 0.49%, respectively, compared to the first sowing date. The results of the present study indicated that early sowing date and chitosan application had positive effects on the measured characters. Cluster analysis divided the cultivars into two groups. Also, the PCA revealed that the three first PC confirmed about 98% of the total variance among the studied genotypes.

Mode III SIFs for interface cracks in an FGM coating-substrate system

Mojtaba Mahmoudi Monfared 국제구조공학회 2017 Structural Engineering and Mechanics, An Int'l Jou Vol.64 No.1

In this study, interaction of several interface cracks located between a functionally graded material (FGM) layer and an elastic layer under anti-plane deformation based on the distributed dislocation technique (DDT) is analyzed. The variation of the shear modulus of the functionally graded coating is modeled by an exponential and linear function along the thickness of the layer. The complex Fourier transform is applied to governing equation to derive a system of singular integral equations with Cauchy type kernel. These equations are solved by a numerical method to obtain the stress intensity factors (SIFs) at the crack tips. The effects of non-homogeneity parameters for exponentially and linearly form of shear modulus, the thickness of the layers and the length of crack on the SIFs for several interface cracks are investigated. The results reveal that the magnitude of SIFs decrease with increasing of FG parameter and thickness of FGM layer. The values of SIFs for FGM layer with exponential form is less than the linear form.

Transient analysis of several cracks in an orthotropic material under impact load

M. M. Monfared,M. Ayatollahi 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.8

In this paper, the dynamic response of an orthotropic plane with multiple cracks is analyzed analytically. The anti-plane impact loading condition is considered. The dislocation solution is utilized to derive integral equations for multiple interacting cracks with any location and orientation in an orthotropic plane. These equations are solved numerically thereby obtaining the dislocation density function on the crack faces and stress intensity factors of cracks. Numerical results are presented to illustrate the influences of parameters such as cracks geometry and orientation on the dynamic stress intensity factors.

Multiple unequal cracks between an FGM orthotropic layer and an orthotropic substrate under mixed mode concentrated loads

M. Hassani,M.M. Monfared,A. Salarvand 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.86 No.4

In the present paper, multiple interface cracks between a functionally graded orthotropic coating and an orthotropic half-plane substrate under concentrated loading are considered by means of the distribution dislocation technique (DDT). With the use of integration of Fourier transform the problem is reduced to a system of Cauchy-type singular integral equations which are solved numerically to compute the dislocation density on the surfaces of the cracks. The distribution dislocation is a powerful method to calculate accurate solutions to plane crack problems, especially this method is very good to find SIFs for multiple unequal cracks located at the interface. Hence this technique allows considering any number of interface cracks. The primary objective of this paper is to investigate the effects of the interaction of multiple interface cracks, load location, material orthotropy, nonhomogeneity parameters and geometry parameters on the modes I and II SIFs. Numerical results show that modes I/II SIFs decrease with increasing the nonhomogeneity parameter and the highest magnitude of SIF occurs where distances between the load location and crack tips are minimal.