Design and Implement of the Ion Implanter’s Ion Gun Power Supplies by Using the Resonant Converters

, Ph.D. Dissertation Sharif University of Technology Beiranvand, Reza (Author) ; Rashidian, Bizhan (Supervisor) ; Zolghadri, Mohammad Reza (Supervisor) ; Alavi, Mohammad Hossein (Co-Advisor)

Abstract

In the Ion Implanter system a controled current through a tungesten filament, supplies the heat which causes the thermoionic emmition to ionize the gas molecules. Then the negativly charged electrones that are boiled off the filament, and also the ones that are removed from the outer ring of the gas molecules during the ionization process, are attracted by an adjustable voltage source. In this thesis, two resonant converter topologies are proposed to designe and to implement the adjustable current and voltage sources for ion implantation system. Unlike the PWM converters soft switching techniques, used auxiliary circuits to reduce the switching losses and EMI noises, in the proposed resonant...

Numerical simulation of surfactant flooding in darcy scale flow

, Article Petroleum Science and Technology ; Vol. 32, Issue. 11 , 2014 , Pages 1365-1374 ; ISSN: 10916466 Morshedi, S ; Foroughi, S ; Beiranvand, M. S ; Sharif University of Technology

2014

Abstract

One of the methods that is used nowadays in enhanced oil recovery is surfactant flooding. The main mechanisms of surfactant flooding in reservoir consist of reduction of interfacial tension between water and oil and modification of rock wettability. In this study, the authors simulate the surfactant injection process in Darcy scale and in one-dimensional, multicomponent, multiphase state, and effects of physical phenomena such as adsorption, dispersion, convection, and exchange between fluids and solids are considered. Wettability alteration of reservoir rock due to presence of surfactant in injected fluid is detected in relative permeability and capillary pressure curves. First, the authors...

A novel zero-voltage-transition bridgeless PFC with reduced conduction losses

, Article 2011 2nd Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2011, 16 February 2011 through 17 February 2011 ; February , 2011 , Pages 587-592 ; 9781612844213 (ISBN) Haghi, R ; Zolghadri, M. R ; Beiranvand, R ; Sharif University of Technology

2011

Abstract

In this paper, a new zero-voltage-switching high power-factor (PF) rectifier with Line-Modulated Fixed-Off-Time current control is introduced, that off time is a function of the instantaneous line voltage. The auxiliary circuit provides soft switching for all semiconductor devices, without any extra current and voltage stress on the main switches. The proposed converter is bridgeless, and all semiconductor devices are soft switched. In addition, there is no extra stress on the switches. Thus, the conduction and switching losses are reduced and maximum efficiency is achieved. A 250W, with an input ac voltage of 90265 Vrms and an output voltage 400 Vdc, 100 kHz is designed and simulated to...

Novel zero-voltage-switching bridgeless PFC converter

, Article Journal of Power Electronics ; Volume 13, Issue 1 , 2013 , Pages 40-50 ; 15982092 (ISSN) Haghi, R ; Zolghadri, M. R ; Beiranvand, R ; Sharif University of Technology

2013

Abstract

In this paper, a new zero-voltage-switching, high power-factor, bridgeless rectifier is introduced. In this topology, an auxiliary circuit provides soft switching for all of the power semiconductor devices. Thus the switching losses are reduced and the highest efficiency can be achieved. The proposed converter has been analyzed and a design procedure has been introduced. The control circuit for the converter has also been developed. Based on the given approach, a 250 W, 400 Vdc prototype converters has been designed at 100 kHz for universal input voltage (90-264 Vrms) applications. A maximum efficiency of 94.6% and a power factor correction over 0.99 has been achieved. The simulation and...

Carbon nanotubes in cancer therapy: A more precise look at the role of carbon nanotube-polymer interactions

, Article Chemical Society Reviews ; Volume 42, Issue 12 , Feb , 2013 , Pages 5231-5256 ; 03060012 (ISSN) Adeli, M ; Soleyman, R ; Beiranvand, Z ; Madani, F ; Sharif University of Technology

2013

Abstract

Despite the great potential of carbon nanotubes (CNTs) in various areas of biomedicine, concerns regarding their carcinogenicity, inefficient dispersion in aqueous solutions and biological activity in vivo still remain. One important and feasible route to overcome these barriers is modification of CNTs with polymers, which are widely studied and play a vital role in biological and biomedical fields, especially in drug delivery. This comprehensive review focuses on the achievements of our and other groups in currently used methods to functionalize the surface of CNTs with polymers to produce anticancer drug delivery systems. We have intensively studied covalent and noncovalent interactions...

Effect of laser additive manufacturing parameters on hardness and geometry of Inconel 625 parts manufactured by direct laser metal deposition

, Article Optik ; Volume 249 , 2022 ; 00304026 (ISSN) Nankali, M ; Akbari, J ; Moradi, M ; Malekshahi Beiranvand, Z ; Sharif University of Technology

Elsevier GmbH 2022

Abstract

This research investigates the effect of process parameters on the geometry and properties of In625 parts, manufactured by the direct laser metal deposition (DLMD) process. For this purpose, eight parts, consisting of 5 layers on top of each other, were manufactured, and the effect of laser power, laser focal plane position, and scanning speed on the height, width, and surface smoothness of each of them was investigated using design of experiment (DOE). The experimental results showed that the height of the parts manufactured by 800 W/mm and 200 W/mm of energy density is 3.69 mm and 6.12 mm, respectively. The thickness of the parts manufactured by 80 W/mm and 200 W/mm of energy density is...

Design of a gas lift system to increase oil production from an Iranian offshore well with high water cut

, Article Australian Journal of Basic and Applied Sciences ; Volume 5, Issue 11 , 2011 , Pages 1561-1565 ; 19918178 (ISSN) Beiranvand, M. S ; Morshedi, S ; Sedaghat, M. H ; Aghahoseini, S ; Sharif University of Technology

2011

Abstract

One of the most important production issues in oil fields is high water production which may lead to wells killing and reduction in an economical production period. With the increment of water production or decrease of reservoir pressure, reservoir drawdown pressure reduces which causes reduction in oil production rate. To preserve the reservoir production, we should apply one of the proposed methods; namely, increasing the reservoir pressure, preventing water source invasion or using artificial lift technique. To compensate this reduction, continuous gas injection into the wells can be used. The injected gas combines with fluid in tubing and the density of the fluid decreases, thereby...

Wide adjustable range LLC resonant converter's maximum switching frequency for realizing the ZVS operation

, Article Proceedings - 2010 18th Iranian Conference on Electrical Engineering, ICEE 2010, 11 May 2010 through 13 May 2010 ; 2010 , Pages 745-752 ; 9781424467600 (ISBN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, M. H ; Sharif University of Technology

2010

Abstract

In this paper, the FHA and a simple TDA approaches have been used to derive the normalized maximum switching frequency of wide adjustable range LLC resonant converter for realizing the ZVS operation even under the worst-case conditions. By accounting the resonant current higher harmonics, more accurate expressions are derived. These analyses demonstrate that the normalized maximum switching frequency depends on the dead-time and the converter inductance ratio. It also depends on the ratio of the converter resonant capacitor and the effective capacitance appeared in parallel with the power MOSFETs drain-sources. The simulated and experimental results are in good agreement with the derived...

Optimizing the normalized dead-time and maximum switching frequency of a wide-adjustable-range LLC resonant converter

, Article IEEE Transactions on Power Electronics ; Volume 26, Issue 2 , August , 2011 , Pages 462-472 ; 08858993 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2011

Abstract

LLC resonant converter has been widely used in dcdc converters. In this paper, optimum dead-time and maximum switching frequency of a wide-adjustable-range LLC resonant converter are investigated for realizing the zero voltage switching (ZVS) operation even under the worst-case conditions. Analyses demonstrate that these parameters depend on the converter inductance ratio and ratio of the converter resonant capacitor and the effective capacitance appeared in parallel with the drainsources of the power MOSFETs. The necessary dead time for realizing the ZVS operation can be minimized by choosing the normalized maximum switching frequency, properly. Using the dead-time optimum value, soft...

Optimizing the LLC-LC resonant converter topology for wide-output-voltage and wide-output-load applications

, Article IEEE Transactions on Power Electronics ; Volume 26, Issue 11 , 2011 , Pages 3192-3204 ; 08858993 (ISSN) Beiranvand, R ; Zolghadri, M. R ; Rashidian, B ; Alavi, S. M. H ; Sharif University of Technology

2011

Abstract

LLC-LC resonant converter is a suitable circuit topology to design switched-mode power supplies for wide-output-voltage and wide-output-load applications. In this paper, a design procedure is introduced to optimize this converter. Unlike soft switching techniques for pulse width modulated converters, which usually apply an active auxiliary circuit to reduce switching losses and EMI, in the proposed converter, not only such circuits are not used, but also all of the parasitic elements are merged to the converters main components. Zero-voltage switching (ZVS) operation is realized for all power devices under all operating conditions. Thus, this converter is a suitable choice for...

A design procedure for optimizing the LLC resonant converter as a wide output range voltage source

, Article IEEE Transactions on Power Electronics ; Volume 27, Issue 8 , 2012 , Pages 3749-3763 ; 08858993 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2012

Abstract

LLC resonant converter is one of the most suitable circuit topologies that have been introduced for designing constant output voltage switched-mode power supplies. In this paper, a design procedure is introduced for using this converter as a wide output range voltage source. Unlike constant output voltage applications which need small converter inductance ratio and narrow switching frequency variations, for wide output range applications, large values of these parameters are needed simultaneously and should be optimized. Instead of minimizing the components stresses, leading to a great value of the inductance ratio, proper choice of the converter parameters resulting in a smaller inductance...

Using LLC resonant converter for designing wide-range voltage source

, Article IEEE Transactions on Industrial Electronics ; Volume 58, Issue 5 , 2011 , Pages 1746-1756 ; 02780046 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2011

Abstract

LLC resonant converter with significant resonant inductance is proposed for designing an adjustable wide-range regulated voltage source. Large resonant inductance increases output voltage adjustment range and conversion efficiency, particularly at light loads. Soft switching is achieved for all power devices under all operating conditions by choosing the dead time and maximum switching frequency properly and operating in the converter's inductive region. Using a power-factor-correction (PFC) converter reduces the resonant converter's output voltage dependence to the variations of the main ac input voltage. Thus, the compensation of the load variations and the wide-range adjustment of the...

Designing an adjustable wide range regulated current source

, Article IEEE Transactions on Power Electronics ; Volume 25, Issue 1 , 2010 , Pages 197-208 ; 08858993 (ISSN) Beiranvand, R ; Rashidian, B ; Zolghadri, M. R ; Alavi, S. M. H ; Sharif University of Technology

2010

Abstract

LLC resonant converter has been used widely as dc-dc converter for achieving constant dc voltage. In this paper, an LLC resonant converter, by adding an inductance to its conventional topology and considering the rectifying stage stray inductances, is proposed for an adjustable wide range regulated current source (20-200 A dc) for using as ion implanter's filament power supply. The additional inductor increases output current adjustment range and efficiency, especially at light loads. Transformer's leakage inductances and rectifying stage stray inductances have been considered. Because of these inductances, the rectifier stage always works in continuous conduction mode, and its conduction...

Selection of excitation signal waveform for improved performance of wound-rotor resolver*

, Article 10th International Power Electronics, Drive Systems and Technologies Conference, PEDSTC 2019, 12 February 2019 through 14 February 2019 ; 2019 , Pages 160-165 ; 9781538692547 (ISBN) Farhadi Beiranvand, A ; Alipour Sarabi, R ; Nasiri Gheidari, Z ; Tootoonchian, F ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2019

Abstract

Wound-Rotor (WR) resolvers are similar to two-phase synchronous generators. Their difference is related to the excitation signal. While DC voltage is used for exciting synchronous generator, high frequency AC voltage is employed for that of resolver. The common waveform for excitation signal of resolver is sinusoidal voltage. However, preparing the high frequency sinusoidal voltage in the resolver to digital converter (RDC) is always a challenge. Therefore, in this paper different high frequency AC waveforms are applied as the excitation signal of the resolver and the estimated position, resulted from RDC, is discussed. The aim of this work is to find an appropriate excitation waveform that...

A mechanistic understanding of the water-in-heavy oil emulsion viscosity variation: effect of asphaltene and wax migration

, Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 608 , 2021 ; 09277757 (ISSN) Piroozian, A ; Hemmati, M ; Safari, M ; Rahimi, A ; Rahmani, O ; Aminpour, S. M ; Beiranvand Pour, A ; Sharif University of Technology

Elsevier B.V 2021

Abstract

The role of emulsions as a prevalent phenomenon is broadly investigated in the petroleum industry since forming the emulsion has many severe harmful implications. Heavy components of crude oil such as wax and asphaltene make the water-in-oil (w/o) emulsion more stable, while the role of these components on the emulsion viscosity has not been fully understood. In this regard, to find a proper demulsifier to break these emulsions, it is necessary to know the mechanisms of emulsion formation by heavy oil components. In this study, the effects of waxy-oil and asphaltenic-oil on w/o emulsion were investigated by measuring volume and viscosity of the formed emulsion after an elapsed time, followed...

A misbehavior‐tolerant multipath routing protocol for wireless Ad hoc networks [electronic resource]

, Article International Journal of Research in Wireless Systems (IJRWS) ; Vol. 2, Issue 9, pp. , Sep. 2013 Sedghi, H. (Haniyeh) ; Pakravan, Mohammad Reza ; Aref, Mohammad Reza ; Sharif University of Technology

Abstract

Secure routing is a major key to service maintenance in ad hoc networks. Ad hoc nature exposes the network to several types of node misbehavior or attacks. As a result of the resource limitations in such networks nodes may have a tendency to behave selfishly. Selfish behavior can have drastic impacts on network performance. We have proposed a Misbehavior-Tolerant Multipath Routing protocol (MTMR) which detects and punishes all types of misbehavior such as selfish behavior, wormhole, sinkhole and grey-hole attacks. The protocol utilizes a proactive approach to enforce cooperation. In addition, it uses a novel data redirection method to mitigate the impact of node misbehavior on network...

Analysis and data-based reconstruction of complex nonlinear dynamical systems : using the methods of stochastic processes

, Book Rahimi Tabar, M. Reza

Springer International Publishing 2019

Abstract

This book focuses on a central question in the field of complex systems: Given a fluctuating (in time or space), uni- or multi-variant sequentially measured set of experimental data (even noisy data), how should one analyse non-parametrically the data, assess underlying trends, uncover characteristics of the fluctuations (including diffusion and jump contributions), and construct a stochastic evolution equation?
Here, the term "non-parametrically" exemplifies that all the functions and parameters of the constructed stochastic evolution equation can be determined directly from the measured data.
The book provides an overview of methods that have been developed for the analysis of...

Fabrication and Study of Mechanical Behavior of in Situ Microfibrillar- Reinforced Composites of Polypropylene/Recycled Poly (Ethylene Terephthalate)Toughened with Rubber Particles

, M.Sc. Thesis Sharif University of Technology Motahari, Tayebeh (Author) ; Bagheri, Reza (Supervisor) ; Alizadeh, Reza (Supervisor)

Abstract

The use of polymers is increasing day by day due to low density, reasonable price and ability to produce different products. On the other hand, the accumulation of polymer wastes in nature is one of the environmental concerns in today's world, which is mainly due to the widespread use of polymers in the packaging industry and disposable applications. In order to solve this problem, recycling is recommended as the most appropriate and economical solution. Because in addition to consuming polymer waste, it also saves energy and reduces carbon footprint.Polyethylene terephthalate (PET) is one of the polymeric materials which; It has a special place in the packaging industry and is widely used...

Characterization of Mechanical Properties of Polymer Nanocomposites with Spherical Inhomogeneities

, M.Sc. Thesis Sharif University of Technology Goudarzi, Taha (Author) ; Naghdabadi, Reza (Supervisor) ; Bagheri, Reza (Supervisor)

Abstract

The improved properties of nanocomposites are not achievable with conventional composites. Scale effect is one the most important parameters in the physical and mechanical properties of polymeric nanocomposites. One of the physical phenomena, which can be related to the scale effect, is the very large interface between the nanoparticles and the polymeric matrices. Motional behavior and conformation of polymeric chains change near the nanoparticles surfaces. Due to high interface of the nanoparticles with the polymeric matrices the amount of these types of changes in the polymeric chains are so large that can change the physical and mechanical properties of polymeric nanocomposites. In this...

On small uniquely vertex-colourable graphs and Xu's conjecture [electronic resource]

, Article Discrete Mathematics ; Volume 223, Issues 1–3, 28 August 2000, Pages 93–108 Daneshgar, A. (Amir) ; Naserasr, Reza ; Sharif University of Technology

Abstract

Consider the parameter Λ(G) = |E(G)| - |V(G)|(k - 1) + (k2) for a k-chromatic graph G, on the set of vertices V(G) and with the set of edges E(G). It is known that Λ(G)≥0 for any k-chromatic uniquely vertex-colourable graph G (k-UCG), and, S.J. Xu has conjectured that for any k-UCG, G, Λ(G) = 0 implies that cl(G) = k; in which cl(G) is the clique number of G. In this paper, first, we introduce the concept of the core of a k-UCG as an induced subgraph without any colour-class of size one, and without any vertex of degree k - 1. Considering (k, n)-cores as k-UCGs on n vertices, we show that edge-minimal (k, 2k)-cores do not exist when k ≥ 3, which shows that for any edge-minimal k-UCG on 2k...