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    Low Grade Heat Driven Multi-Effect Distillation and Desalination

    , Book Rahimi, Bijan ; Chua, Hui Tong
    Elsevier  2017
    Abstract
    Low Grade Heat Driven Multi-effect Distillation and Desalination describes the development of advanced multi-effect evaporation technologies that are driven by low grade sensible heat, including process waste heat in refineries, heat rejection from diesel generators or microturbines, and solar and geothermal energy. The technologies discussed can be applied to desalination in remote areas, purifying produced water in oil-and-gas industries, and to re-concentrate process liquor in refineries.
    This book is ideal for researchers, engineering scientists, graduate students, and industrial practitioners working in the desalination, petrochemical, and mineral refining sectors, helping them... 

    Generation and collapse of bubbles in lead silicate glass

    , Article Glass Physics and Chemistry ; Volume 41, Issue 3 , May , 2015 , Pages 307-315 ; 10876596 (ISSN) Rahimi, R. A ; Sadrnezhaad, S. K ; Sharif University of Technology
    Maik Nauka Publishing / Springer SBM  2015
    Abstract
    Presence of bubbles affects quality of the lead silicate glass (LSG) samples. This paper presents the most recent results obtained on formation and collapse of bubbles in LSG melts. Main sources of the bubbles are dissolved gases and redox reactions. A foamy layer full of bubbles rapidly forms at top of the molten phase. Effect of viscosity and density of the melt on content and ascension rate of the bubbles are investigated. Number and mean diameter of the bubbles and thickness of the top bubbly layer are calculated from gas volume measurements and image analysis via J software  

    Interfacial control at janus wsse/triazine g-c3n4 heterostructures in developing type-ii and z-scheme photocatalysts

    , Article Journal of Physical Chemistry C ; Volume 127, Issue 34 , 2023 , Pages 16792-16801 ; 19327447 (ISSN) Rahimi, K ; Zaker Moshfegh, A. R ; Sharif University of Technology
    American Chemical Society  2023
    Abstract
    Tailoring band gap energies and band alignment types of heterogeneous photocatalysts is critical for their performance in particular applications. Here, by performing calculations in the framework of density functional theory, we study the role of interface in control and tuning band gap and band alignment characteristics of two-dimensional van der Waals (vdW) heterostructures of monolayers of triazine graphitic carbon nitride (tg-C3N4) and Janus tungsten sulfide selenide (WSSe) by varying either S or Se atomic layers. Then we investigate how the vdW heterostructures (i.e., tg-C3N4/SWSe and tg-C3N4/SeWS) over both tg-C3N4 and WSSe surface sides can serve as an efficient water-splitting... 

    The formation of atomic nanoclusters on graphene sheets

    , Article Nanotechnology ; Volume 20, Issue 13 , 2009 ; 09574484 (ISSN) Neek Amal, M ; Asgari, R ; Rahimi Tabar, M. R ; Sharif University of Technology
    2009
    Abstract
    The formation of atomic nanoclusters on suspended graphene sheets has been investigated by employing a molecular dynamics simulation at finite temperature. Our systematic study is based on temperature-dependent molecular dynamics simulations of some transition and alkali atoms on suspended graphene sheets. We find that the transition atoms aggregate and make various size nanoclusters distributed randomly on graphene surfaces. We also report that most alkali atoms make one atomic layer on graphene sheets. Interestingly, the potassium atoms almost deposit regularly on the surface at low temperature. We expect from this behavior that the electrical conductivity of a suspended graphene doped by... 

    Markov analysis and Kramers-Moyal expansion of the ballistic deposition and restricted solid-on-solid models

    , Article Journal of Statistical Mechanics: Theory and Experiment ; Volume 2008, Issue 2 , 2008 ; 17425468 (ISSN) Kimiagar, S ; Jafari, G. R ; Rahimi Tabar, M. R ; Sharif University of Technology
    2008
    Abstract
    It is well known that the ballistic deposition and the restricted solid-on-solid models belong to the same universality class, having the same roughness and growth exponents. In this paper, we determine some new statistical properties of the two models, such as the Kramers-Moyal coefficients and the Markov length scale, and show them to be distinct for the two models. © 2008 IOP Publishing Ltd  

    Conductance of a disordered graphene superlattice

    , Article Physical Review B - Condensed Matter and Materials Physics ; Volume 79, Issue 16 , 2009 ; 10980121 (ISSN) Abedpour, N ; Esmailpour, A ; Asgari, R ; Rahimi Tabar, M. R ; Sharif University of Technology
    2009
    Abstract
    We study the conductance of disordered graphene superlattices with short-range structural correlations. The system consists of electron- and hole-doped graphenes of various thicknesses, which fluctuate randomly around their mean value. The effect of the randomness on the probability of transmission through the system of various sizes is studied. We show that in a disordered superlattice the quasiparticle that approaches the barrier interface almost perpendicularly transmits through the system. The conductivity of the finite-size system is computed and shown that the conductance vanishes when the sample size becomes very large, whereas for some specific structures the conductance tends to a... 

    Designing gear-shift pattern for an electric vehicle to optimize energy consumption

    , Article ASME International Mechanical Engineering Congress and Exposition, Proceedings (IMECE) ; Vol. 11 , 2010 , pp. 837-846 ; ISBN: 9780791844489 Rahimi, M. A ; Salehi, R ; Alasty, A ; Sharif University of Technology
    2010
    Abstract
    In this paper optimization of energy consumption in an electric vehicle is presented. The main idea of this optimization is based on selecting the best gear level in driving the vehicle. Two algorithms for optimization are introduced which are based on fuzzy rules and fuzzy controllers. In first algorithm, fuzzy controller simulates energy consumption in different gear levels, and chooses the optimum gear level. While in second method, fuzzy controller detects the optimum gear level by measuring the vehicle's average speed and acceleration. To investigate the performance of these controllers, a model of TOSAN vehicle is developed and the controllers outputs are checked in simulation of TOSAN... 

    A generalized total least squares algorithm for RSS-based localization with unknown path-loss model parameters

    , Article 24th Iranian Conference on Electrical Engineering, ICEE 2016, 10 May 2016 through 12 May 2016 ; 2016 , Pages 521-524 ; 9781467387897 (ISBN) Rahimi, G ; Danaee, M. R ; Bayat, S ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2016
    Abstract
    Node localization is of paramount importance to different wireless sensor network (WSN) applications. This paper investigates the received signal strength (RSS) based localization problem with unknown path-loss model parameters. Most works in RSS localization assume the transmit power and path-loss exponent (PLE) are known that is not a realistic assumption in some cases. However this paper, assumes the transmit power and the PLE are both unknown and a novel algorithm for sensor location is proposed. The algorithm is based on the generalized total least-squares (GTLS) method and gives an explicit solution for the localization problem. The performance of the proposed method is compared with... 

    DC partial discharge characteristics for corona, surface and void discharges

    , Article Proceedings of the IEEE International Conference on Properties and Applications of Dielectric Materials, 19 July 2015 through 22 July 2015 ; Volume 2015-October , July , 2015 , Pages 260-263 ; 9781479989034 (ISBN) Rahimi, M. R ; Javadinezhad, R ; Vakilian, M ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2015
    Abstract
    Measurement of partial discharges (PDs) current pulses is found to be one of the most efficient methods to evaluate the high voltage electrical equipment insulation condition. Generators, transformers, cables and transmission lines are especially tested for the presence of PDs. In AC, the solution is well known. Phase-resolved method can be used to detect and determine partial discharge activities. Although phase-resolved method works well under AC voltage; due to lack of a cyclic variation in DC voltage and current this cannot be used when studying partial discharges in DC voltage systems. Therefore, other methods are employed to interpret the partial discharge in DC. For this purpose, the... 

    Detection of thermal infrared (TIR) anomalies related to the M s=5.1 earthquake on Oct. 14, 2004 near Ravar (SE Iran)

    , Article Journal of the Earth and Space Physics ; Volume 35, Issue 4 , 2010 ; 03781046 (ISSN) Askari, Gh ; Hafezi, N ; Rahimi Tabar, M. R ; Ansari, A. R ; Sharif University of Technology
    2010
    Abstract
    Over the last two decades there have been numerous reports from different seismically active regions of the world that thermal infrared (TIR) anomalies can be identified around the epicentral areas before major earthquakes [e.g. (Tronin et al., 2002)]. The TIR anomalies reportedly appear as early as 14 to 7 days before the seismic events and affect areas as large as 1000s to 100,000s km2 in size. Our case study for detection of TIRs using NOAA-AVHRR data(Band 4) is an Ms = 5.1 earthquake that occurred on 14th October 2004 near Ravar in Kerman province located in Loot and Tabas deserts, southeast-central Iran. The area is part of the Golbaf-Sirj seismogenic zone. It includes major faults... 

    Scaling behavior of earthquakes' inter-events time series

    , Article Central European Journal of Physics ; Volume 7, Issue 3 , 2009 , Pages 620-623 ; 18951082 (ISSN) Shadkhoo, S ; Ghanbarnejad, F ; Jafari, G. R ; Rahimi Tabar, M. R ; Sharif University of Technology
    2009
    Abstract
    In this paper, we investigate the statistical and scaling properties of the California earthquakes' inter-events over a period of the recent 40 years. To detect long-term correlations behavior, we apply detrended fluctuation analysis (DFA), which can systematically detect and overcome nonstationarities in the data set at all time scales. We calculate for various earthquakes with magnitudes larger than a given M. The results indicate that the Hurst exponent decreases with increasing M; characterized by a Hurst exponent, which is given by, H = 0:34 + 1:53/M, indicating that for events with very large magnitudes M, the Hurst exponent decreases to 0:50, which is for independent events. © Versita... 

    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... 

    Theoretical analysis of polymeric and crystalline thick films melting with a single gold nanoparticle embedded in a transparent matrix under nanosecond pulsed laser excitation

    , Article Journal of Physics D: Applied Physics ; Volume 45, Issue 47 , 2012 ; 00223727 (ISSN) Rahimi, L ; Bahrampour, A. R ; Pepe, G. P ; Sharif University of Technology
    2012
    Abstract
    Optothermal properties of noble metal nanoparticles can be used in a wide range of applications. This paper presents the results of a theoretical study on the utilization of laser-induced heating of a gold nanoparticle (GNP) to melt a region of a transparent material with sub-wavelength spatial resolution. The considered system consists of a 10 or 15nm diameter GNP fixed inside a silica substrate. The silica surface is covered with a thick film of the transparent polymeric or crystalline material. The heating and melting processes are studied under a 7.5ns pulsed laser illumination. Calculations are conducted under three temperature limits, on the maximum temperature of the free electrons,... 

    Fluctuations, importance of: Complexity in the view of stochastic processes

    , Article Computational Complexity: Theory, Techniques, and Applications ; 2012 , Pages 1131-1154 ; 9781461418009 (ISBN) ; 1461417996 (ISBN) Friedrich, R ; Peinke, J ; Rahimi Tabar, M. R ; Sharif University of Technology
    Springer  2012
    Abstract
    Article Outline: Glossary Definition of the Subject Introduction Stochastic Processes Stochastic Time Series Analysis Applications: Processes in Time Applications: Processes in Scale Future Directions Further Reading Acknowledgment Bibliography  

    Coherent backscattering of electromagnetic waves in random media

    , Article EPL ; Volume 98, Issue 1 , 2012 ; 02955075 (ISSN) Sheikhan, A ; Maass, P ; Rahimi Tabar, M. R ; Sharif University of Technology
    2012
    Abstract
    The single and multiple scattering regimes of electromagnetic waves in a disordered system with fluctuating permittivity are studied by numerical simulations of Maxwell's equations. For an array of emitters and receivers in front of a medium with randomly varying dielectric constant, we calculate the backscattering matrix from the signal responses at all receiver points j to electromagnetic pulses generated at each emitter point i. We show that the statistical properties of the backscattering matrix are in agreement with the recent experimental results for ultrasonic waves (Aubry A. and Derode A., Phys. Rev. Lett., 102 (2009) 084301) and light (Popoff S. M. et al., Phys. Rev. Lett., 104... 

    Sintering of Al2O3-SiC composite from sol-gel method with MgO, TiO2 and Y2O3 addition

    , Article Ceramics International ; Volume 37, Issue 5 , 2011 , Pages 1681-1688 ; 02728842 (ISSN) Mohammad Rahimi, R ; Rezaie, H. R ; Nemati, A ; Sharif University of Technology
    2011
    Abstract
    Al2O3-SiC composite ceramics were prepared by pressureless sintering with and without the addition of MgO, TiO2 and Y2O3 as sintering aids. The effects of these compositional variables on final density and hardness were investigated. In the present article at first α-Al2O3 and β-SiC nano powders have been synthesized by sol-gel method separately by using AlCl 3, TEOS and saccharose as precursors. Pressureless sintering was carried out in nitrogen atmosphere at 1600 °C and 1630 °C. The addition of 5 vol.% SiC to Al2O3 hindered densification. In contrast, the addition of nano MgO and nano TiO2 to Al 2O3-5 vol.% SiC composites improved densification but Y2O3 did not have positive effect on... 

    Packing of nonoverlapping cubic particles: Computational algorithms and microstructural characteristics

    , Article Physical Review E - Statistical, Nonlinear, and Soft Matter Physics ; Volume 94, Issue 6 , 2016 ; 15393755 (ISSN) Malmir, H ; Sahimi, M ; Rahimi Tabar, M. R ; Sharif University of Technology
    American Physical Society  2016
    Abstract
    Packing of cubic particles arises in a variety of problems, ranging from biological materials to colloids and the fabrication of new types of porous materials with controlled morphology. The properties of such packings may also be relevant to problems involving suspensions of cubic zeolites, precipitation of salt crystals during CO2 sequestration in rock, and intrusion of fresh water in aquifers by saline water. Not much is known, however, about the structure and statistical descriptors of such packings. We present a detailed simulation and microstructural characterization of packings of nonoverlapping monodisperse cubic particles, following up on our preliminary results [H. Malmir, Sci.... 

    Microstructural characterization of random packings of cubic particles

    , Article Scientific Reports ; Volume 6 , 2016 ; 20452322 (ISSN) Malmir, H ; Sahimi, M ; Rahimi Tabar, M. R ; Sharif University of Technology
    Nature Publishing Group  2016
    Abstract
    Understanding the properties of random packings of solid objects is of critical importance to a wide variety of fundamental scientific and practical problems. The great majority of the previous works focused, however, on packings of spherical and sphere-like particles. We report the first detailed simulation and characterization of packings of non-overlapping cubic particles. Such packings arise in a variety of problems, ranging from biological materials, to colloids and fabrication of porous scaffolds using salt powders. In addition, packing of cubic salt crystals arise in various problems involving preservation of pavements, paintings, and historical monuments, mineral-fluid interactions,... 

    Tipping Cascades in Complex Networks: Dynamics and Control

    , M.Sc. Thesis Sharif University of Technology Shahrabi, Ali (Author) ; Rahimi Tabar, Mohammad Reza (Supervisor)
    Abstract
    Tipping points occur in diverse systems in various disciplines such as ecology, climate science, economy, sociology, and engineering. Critical thresholds in system parameters or state variables at which a tiny perturbation can lead to a qualitative change in the system exist in many subsystems in complex systems. These thresholds are called tipping points, and these subsystems are called tipping elements. Additionally, many systems with tipping points can be modeled as networks of coupled multistable subsystems. Domino-like tippings are called tipping cascades. Considering that these tipping cascades are primarily unprecedented, it is essential to study the dynamics and control of these... 

    Effect of a gap opening on the conductance of graphene superlattices

    , Article Solid State Communications ; Volume 150, Issue 13-14 , 2010 , Pages 655-659 ; 00381098 (ISSN) Esmailpour, M ; Esmailpour, A ; Asgari, R ; Elahi, M ; Rahimi Tabar, M. R ; Sharif University of Technology
    2010
    Abstract
    The electronic transmission and conductance of a gapped graphene superlattice were calculated by means of the transfer-matrix method. The system that we study consists of a sequence of electron-doped graphene as wells and hole-doped graphene as barriers. We show that the transmission probability approaches unity at some critical value of the gap. We also find that there is a domain around the critical gap value for which the conductance of the system attains its maximum value