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    Probabilistic worth assessment of distributed static series compensators

    , Article IEEE Transactions on Power Delivery ; Vol. 26, issue. 3 , 2011 , p. 1734-1743 ; ISSN: 08858977 Dorostkar-Ghamsari, M ; Fotuhi-Firuzabad, M ; Aminifar, F ; Sharif University of Technology
    2011
    Abstract
    The deployment of flexible ac transmission system (FACTS) devices, despite miscellaneous benefits and applications, has been restricted mainly due to their large investment costs. Accordingly, the notion of distributed FACTS (D-FACTS) was recently proposed. Distributed static series compensators (DSSCs), as a new member of D-FACTS, are directly clamped to conductors of transmission lines. The possibility of controlling the compensation rate of DSSCs from the control center affords the active control of network power flow. This paper presents a comprehensive reliability model for the DSSC. The model is then reduced and a state-space representation is extracted for a transmission line with a... 

    Probabilistic worth assessment of distributed static series compensators

    , Article IEEE Transactions on Power Delivery ; Volume 26, Issue 3 , July , 2011 , Pages 1734-1743 ; 08858977 (ISSN) Dorostkar Ghamsari, M ; Fotuhi Firuzabad, M ; Aminifar, F ; Sharif University of Technology
    2011
    Abstract
    The deployment of flexible ac transmission system (FACTS) devices, despite miscellaneous benefits and applications, has been restricted mainly due to their large investment costs. Accordingly, the notion of distributed FACTS (D-FACTS) was recently proposed. Distributed static series compensators (DSSCs), as a new member of D-FACTS, are directly clamped to conductors of transmission lines. The possibility of controlling the compensation rate of DSSCs from the control center affords the active control of network power flow. This paper presents a comprehensive reliability model for the DSSC. The model is then reduced and a state-space representation is extracted for a transmission line with a... 

    A unit commitment for electricity market participation of wind farms

    , Article 2017 IEEE Power and Energy Society Innovative Smart Grid Technologies Conference, ISGT 2017, 23 April 2017 through 26 April 2017 ; 2017 ; 9781538628904 (ISBN) Abbasi, E ; Hosseini, S. H ; Dorostkar Ghamsari, M ; Sharif University of Technology
    2017
    Abstract
    In this paper a reliability, emission, and network security constrained unit commitment (UC) with the focus on wind power integration is formulated. It is shown that clearing both energy and spinning reserve markets taking into account network constraints provides a reliable and economic solution for day-ahead operation planning of a power system with a significant amount of thermal and wind power in the generation portfolio. The developed UC is formulated and implemented in MATLAB. The IEEE 24-Bus Reliability Test System (RTS) is used to verify the UC method by simulation. © 2017 IEEE  

    Value of distribution network reconfiguration in presence of renewable energy resources

    , Article IEEE Transactions on Power Systems ; Volume 31, Issue 3 , 2016 , Pages 1879-1888 ; 08858950 (ISSN) Dorostkar Ghamsari, M. R ; Fotuhi Firuzabad, M ; Lehtonen, M ; Safdarian, A ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    Proliferation of renewable energy resources in distribution networks has captured distribution companies' attention towards more active management tools. Thanks to the smart grid paradigm, hourly network reconfiguration, which is still among immature ideas, can bring the activeness required to handle fluctuating output of renewable resources. The aim of this study is to analyze the worthiness of the hourly reconfiguration in the presence of renewable energy resources. For doing so, a mathematical model is devised to minimize daily network losses via applying hourly reconfigurations. The model is a mixed integer second-order cone programming problem and is solved via MOSEK solver. The... 

    Optimal distributed static series compensator placement for enhancing power system loadability and reliability

    , Article IET Generation, Transmission and Distribution ; Volume 9, Issue 11 , 2015 , Pages 1043-1050 ; 17518687 (ISSN) Dorostkar Ghamsari, M ; Fotuhi Firuzabad, M ; Aminifar, F ; Safdarian, A ; Lehtonen, M ; Sharif University of Technology
    Institution of Engineering and Technology  2015
    Abstract
    Distributed static series compensator (DSSC) is a member of the family of distributed flexible AC transmission system devices that can be attached directly to conductors of transmission lines. DSSCs are able to compensate for and adjust the line reactance; thus, they could be widely used in stability-limited transmission systems. Owing to economic matters, the optimal placement of DSSCs is of a great interest from practical viewpoints. This study presents an approach to find the optimal locations of DSSCs to enhance the system loadability and reliability using the DC load flow model. The optimisation problem is solved using the mixed-integer linear programming. A compromise between improving... 

    Improve capacity utilization of substation transformers via distribution network reconfiguraion and load transfer

    , Article EEEIC 2016 - International Conference on Environment and Electrical Engineering, 7 June 2016 through 10 June 2016 ; 2016 ; 9781509023196 (ISBN) Dorostkar Ghamsari, M. R ; Fotuhi Firuzabad, M ; Safdarian, A ; Hoshyarzade, A. S ; Lehtonen, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    Nowadays, the essentiality of asset management in power systems and higher utilization of resources have become more critical to keep pace with the radically growing demand of today's networks. Power transformers are amongst the most important equipments installed in power distribution systems. Therefore, this paper presents a novel methodology to improve the utilization of substation transformers. In this methodology, the transformer utilization of a two-transformer substation is increased via reconfiguration considering the single contingency policy (SCP). The online reconfiguration helps to maximize the amount of load transferred from a substation with a failed transformer to its... 

    Stochastic operation framework for distribution networks hosting High wind penetrations

    , Article IEEE Transactions on Sustainable Energy ; 2017 ; 19493029 (ISSN) Dorostkar Ghamsari, M. R ; Fotuhi Firuzabad, M ; Lehtonen, M ; Safdarian, A ; Hoshyarzadeh, A. S ; Sharif University of Technology
    2017
    Abstract
    In this paper, a stochastic framework including two hierarchical stages is presented for the operation of distribution systems with high penetrations of wind power. In the first stage, termed Day Ahead Market Stage (DAMS), power purchases from day-ahead (DA) market and commitment of distributed generations (DGs) are determined. The DAMS model is formulated as a mixed integer linear programming (MILP) optimization problem. The uncertainty in predictions of wind generation, real time prices, and load profile are included in the optimization problem according to a scenario-based stochastic programming approach. The risk encountered due to the uncertainties is also taken into account. The... 

    The Effect of Reconfiguration on the Operation of Smart Distribution Systems with Distributed Generations

    , Ph.D. Dissertation Sharif University of Technology Dorostkar Ghamsari, Mohammad Reza (Author) ; Fotuhi-Firuzabad, Mahmud (Supervisor)
    Abstract
    In this dissertation, the value of distribution network reconfiguration in presence of distributed generation is investigated. In the first step, a mathematical optimization model is devised to minimize daily network losses via applying hourly reconfigurations. The results show that the hourly reconfiguration reduces the losses. Then, sensitivity analyses on the renewable penetration, wind and load correlation, switching cost and wind power prediction are conducted and discussed. The switching cost analysis revealed that a great amount of loss reduction could be attained with a small number of switching operations. The worthiness of reconfiguration becomes more in systems with high... 

    Reliability Assessment of DSSC devices and Optimal Placement of them with the aim of Enhancing Power System Loadability and Reliability

    , M.Sc. Thesis Sharif University of Technology Dorostkar Ghamsari, Mohammad Reza (Author) ; Fotuhi-Firuzabad, Mahmoud (Supervisor)
    Abstract
    One of the important problems in fulfilling the consumers' power demand that has been especially intensified after restructuring is transmission line congestion. To solve this problem, either new transmission lines should be constructed or the existing transmission lines should be better utilized. Construction of new transmission lines is both expensive and time consuming. Therefore, it is usually better to enhance the utilization of the existing transmission assets. FACTS devices have been introduced over the past decades to enhance power systems operation. However, wide scale deployment of them has not occurred yet due to their high initial investment cost and some other problems. In order... 

    Fast and facile etching of gold nanorods by n-halosuccinimides: toward multicolorimetric identification and quantification of 20 natural amino acids

    , Article Analytical Chemistry ; Volume 95, Issue 43 , 2023 , Pages 15985-15993 ; 00032700 (ISSN) Ghamsari, M ; Orouji, A ; Hormozi Nezhad, M. R ; Sharif University of Technology
    American Chemical Society  2023
    Abstract
    Gold nanorods (AuNRs) have recently become fascinating chromophores in the field of colorimetric sensing because of their eye-catching rainbow colors along with the high dimensionality of their optical profile. The etching of AuNRs using an analyte-sensitive oxidizing agent is particularly an attractive tool not only for adjusting their plasmonic behavior through altering their aspect ratio but also for correlating the observed signal with the identity and concentration of the analyte. However, the deployment of this strategy in the field of sensing has been seriously hindered by various factors ranging from slow etching kinetics and the need for nonambient temperatures to low degrees of... 

    Nanoplasmonic decoration of sacrificial bacteria: directing interparticle coupling toward multiplex analysis of antiseptic alcohols

    , Article ACS Applied Materials and Interfaces ; Volume 15, Issue 21 , 2023 , Pages 26081-26092 ; 19448244 (ISSN) Ghamsari, M ; Fahimi Kashani, N ; Hormozi Nezhad, M. R ; Sharif University of Technology
    American Chemical Society  2023
    Abstract
    Engineering interparticle plasmon coupling through controlling the assembly of plasmonic NPs onto the surface of sacrificial substrates is quite promising for establishing inherently absent selectivity or sensitivity toward a particular analyte. Herein, we introduce a robust sensor array strategy based upon the assembly of gold nanoparticles (AuNPs) on the cysteamine-modified surface of two Gram-positive probiotic bacteria, i.e., Lactobacillus reuteri (LBR) and Bifidobacterium lactis (BFL), as potential sacrificial substrates, for discrimination and quantification of antiseptic alcohols (AAs) comprising methanol, ethanol, and isopropanol. In fact, the damage of the bacterial membrane upon... 

    The role of reactants and droplet interfaces on nucleation and growth of ZnO nanorods synthesized by vapor-liquid-solid (VLS) mechanism

    , Article Journal of Alloys and Compounds ; Volume 455, Issue 1-2 , 2008 , Pages 353-357 ; 09258388 (ISSN) Hejazi, S. R ; Madaah Hossein, H. R ; Ghamsari, M. S ; Sharif University of Technology
    2008
    Abstract
    Short ZnO nanorods and long ZnO nanowires have been produced on SiO2 and Si substrates by VLS and VS mechanisms via a double tube chemical vapor transport and condensation (CVTC) process. The role of reactants and droplet interfaces on the nucleation and growth of ZnO nanorods have been investigated. A conceptual model for nucleation of ZnO nanorods has been proposed by describing the half-oxidation and reduction reactions at the growth front. The importance of Zn vapor in the nucleation phenomena has been studied by changing starting materials. Atomic force microscopy (AFM), scanning electron microscopy (SEM), and EDX analysis have been used to characterize ZnO nanorods and investigate the... 

    Preparation and characterization of ZnO nanoparticles by a novel sol-gel route

    , Article Materials Letters ; Volume 61, Issue 14-15 , 2007 , Pages 3265-3268 ; 0167577X (ISSN) Vafaee, M ; Sasani Ghamsari, M ; Sharif University of Technology
    2007
    Abstract
    In this study, ZnO nanoparticles with 3 to 4 nm size and spherical shape have been prepared. For the first time, TEA (triethanolamine) as a surfactant has been used for the preparation of ZnO nanoparticles. The best concentration of each component was adjusted through comparison between different sol absorption spectra. The best sol regarding its optical property was subjected to analysis by photoluminescence spectroscopy. TEM micrograph and electron diffraction pattern of these particles were obtained to represent the morphology and crystalline phase of the particles, respectively. Experimental results have shown that the prepared zinc oxide nanoparticles by this method have higher... 

    Effect of brookite presence on nanocrystalline anatase - Rutile phase transformation

    , Article International Journal of Nanotechnology ; Volume 6, Issue 10-11 , 2009 , Pages 961-972 ; 14757435 (ISSN) Mahshid, S ; Askari, M ; Sasani Ghamsari, M ; Sharif University of Technology
    2009
    Abstract
    TiO2nanocrystals were prepared by hydrolysis and peptisation of titanium isopropoxide under different pH values. The as-prepared powder of very fine anatase crystallites ranges from 8 nm in acidic solution of pH 3 to 10 nm in basic solution of pH 8. Heat treatment of the powders leads to grain growth and anatase - rutile transformation. Experimental results have shown that the anatase to rutile phase transformation in the heat-treated powders depend not only on primary crystallite size but also the presence of brookite phase. It is observed that in the powders with the same size the presence brookite phase would accelerate the anatase to rutile transformation. Furthermore it has been found... 

    Plasmonic noble metal (Ag and Au) nanoparticles: from basics to colorimetric sensing applications

    , Article Gold and Silver Nanoparticles: Synthesis and Applications ; 2023 , Pages 1-58 ; 978-032399454-5 (ISBN) Fahimi Kashani, N ; Orouji, A ; Ghamsari, M ; Sahoo, S. K ; Hormozi Nezhad, M. R ; Sharif University of Technology
    Elsevier  2023
    Abstract
    The unique optical properties of plasmonic gold (Au) and silver Ag) nanoparticles (NPs) due to localized surface plasmon resonance (LSPR), surface modifications of Au and Ag NPs through non-covalent/covalent conjugations, and their applications in colorimetric detection of various ionic and neutral analytes are discussed in this chapter. The chapter begin with the basics of LSPR phenomenon, and then the effects like surrounding medium, composition, size, shape, structural configuration and interparticle coupling that influenced the LSPR of Au and Ag NPs are discussed. The different design principles for colorimetric assays using plasmonic Au and Ag NPs, such as analyte-induced aggregation... 

    Crack-free nanostructured BaTiO3 thin films prepared by sol-gel dip-coating technique

    , Article Ceramics International ; Vol. 40, issue. 6 , 2014 , pp. 8613-8619 Ashiri, R ; Nemati, A ; Sasani Ghamsari, M ; Sharif University of Technology
    2014
    Abstract
    In this report, crack-free nanostructured barium titanate thin films are prepared by a sol-gel processing method. Glacial acetic acid, barium acetate, titanium tetraisopropyl alkoxide, 2-propanol and deionized water are used as precursors for preparing stable precursor solution. Then very thin films (thickness=26 nm) are deposited on fused silica substrates. In order to prepare crack-free thin films of BaTiO3, much attention is given to solvent evaporation process and a controlled pre-drying process is developed. It is found that the control of the process, especially in the initial stage of drying process is crucial and important for preparation of the crack-free ultrathin nanostructured... 

    Sol stabilization in sol-gel process

    , Article The Sol-Gel Process: Uniformity, Polymers and Applications ; 2011 , Pages 787-818 ; 9781617613210 (ISBN) Ghamsari, M. S ; Mehranpour, H ; Radiman, S ; Sharif University of Technology
    Nova Science Publishers, Inc  2011
    Abstract
    The sol-gel process as a chemical route is widely used in the fields of materials science and engineering. Historically, the sol-gel techniques have been developed during the past 40 years as an alternative process for glasses and ceramics production [1]. It is reported that the sol-gel process had been introduced by Ebelman [2], who had prepared a transparent SiO2 thin film from slow hydrolysis of an ester of silicic acid in 1845. In comparison with other techniques such as CVD or sintering, the sol-gel technique is a very simple process with considerable advantages. This process is low cost, has high controllability and potential application for preparation of different materials and... 

    Nanothickness films, nanostructured films, and nanocrystals of barium titanate obtained directly by a newly developed sol–gel synthesis pathway

    , Article Journal of Materials Science: Materials in Electronics ; Vol. 25, issue. 12 , 2014 , p. 5345-5355 Ashiri, R ; Nemati, A ; Sasani Ghamsari, M ; Dastgahi, M. M ; Sharif University of Technology
    2014
    Abstract
    This work aims to develop a chemically modified sol–gel synthesis pathway for obtaining various barium titanate nanostructures. The method is able to prepare different BaTiO3 nanostructures such as highly stable nanoparticle embedded colloids, highly transparent amorphous nanolayers, nanocrystalline BaTiO3 powders and ultrathin BaTiO3 nanostructured films directly from a precursor solution. All the products have been prepared at a lower temperature and in a more cost-effective way in contrast to other established sol–gel methods. The results show that the optical transparency of the thin films has been significantly improved in contrast to the similar researches. The deposited thin film is... 

    Application of sugimoto model on particle size prediction of colloidal TiO2 nanoparticles

    , Article Nanotechnology 2010: Advanced Materials, CNTs, Particles, Films and Composites - Technical Proceedings of the 2010 NSTI Nanotechnology Conference and Expo, NSTI-Nanotech 2010, 21 June 2010 through 24 June 2010 ; Volume 1 , 2010 , Pages 436-439 ; 9781439834015 (ISBN) Mehranpour, H ; Askari, M ; Sasani Ghamsari, M ; Farzalibeik, H ; Sharif University of Technology
    2010
    Abstract
    In this paper, Sugimoto model has been employed to study the nucleation and the growth of TiO2 nanoparticles. On the base of this model some parameters of the nucleation and the growth of nanoparticles such as supply rate of the solute (Q0), molar volume of the solid (Vm), and mean volumic growth rate of the stable nuclei during the nucleation period (v) were determined. For this approach, TiO2 nanoparticles were synthesized in two stages in an aqueous solution by using HNO3 and TTIP and TIPO as starting materials. In this experiment, it was obviously observed that the changing of Ti+4concentrations was followed with LaMer diagram. Typical obtained results were v=2.93×102 nm3.s -1 and... 

    Design and optimization of Gregorian-based reflector systems for thz imaging system optics

    , Article 4th West Asian Symposium on Optical and Millimeter-Wave Wireless Communications, WASOWC 2022, 12 May 2022 through 13 May 2022 ; 2022 ; 9781665409131 (ISBN) Koohi Ghamsari, M. H ; Ahmadi Boroujeni, M ; Babanejad, S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2022
    Abstract
    The application of reflector antenna configurations in designing the optical section of terahertz imaging systems has attracted great attention in recent years. The advantages of reflective optics in comparison with refractive optics is one of the main reasons for this trend. Specular reflection in a broad spectral range, no or little reflection and transmission loss, no chromatic aberration, and high reliability in high power applications configuration are just some of these advantages. In this paper, the optical performance of a modified off-axis aberrations-free Gregorian-based reflector antenna system is studied as an optical section of a terahertz imaging system. By applying a precise...