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    Modeling of point and non-point source pollution of nitrate with SWAT in the Jajrood river watershed, Iran

    , Article International Agricultural Engineering Journal ; Volume 19, Issue 2 , 2010 , Pages 23-31 ; 08582114 (ISSN) Jamshidi, M ; Tajrishy, M ; Maghrebi, M ; Sharif University of Technology
    2010
    Abstract
    The Latian dam reservoir is one of the most important drinking water sources for Tehran, Iran. Nitrate is a major water quality problem in this reservoir. The Jajrood River, the most important water source for the reservoir, discharges large amounts of nutrients to it every year including high levels of nitrate, a pollutant of particular concern. This study presents the results obtained from simulating different point source and nonpoint source impacts on the fate and transport of nitrate in the 470 km2 Jajrood watershed using the Soil and Water Assessment Tool (SWAT) model version 2000 (SWAT2000). The SWAT model was calibrated and validated over an extended time period (1997-2005) for this... 

    Assessment of jajrood river watershed microbial pollution: Sources and fates

    , Article Environmental Engineering and Management Journal ; Volume 9, Issue 3 , 2010 , Pages 385-391 ; 15829596 (ISSN) Maghrebi, M ; Tajrishy, M ; Jamshidi, M ; Sharif University of Technology
    2010
    Abstract
    The Jajrood River watershed is on of the main drinking water resurces of Tehran, the capital city of Iran. In addition it provides many recreational usages. However, a variety of microbial pollutions is commonly perecived in the Jajrood River, among them a high concentration of coliform group bacteria that has caused strong concerns. In this article, different aspects of microbial pollution as well as the main microbial pollution sources in the region are discussed. Coliform group bacterial die-off rates have been evaluated as the key parameters that govern bacterial fate in the watershed and were estimated using both laboratory and field data investigations. The high values of the bacterial... 

    Wall stress estimation of human heart under the effect of high accelerations

    , Article ASME 2013 Summer Bioengineering Conference, SBC 2013 ; Volume: 1 , 2013 ; 9780791855614 (ISBN) Jamshidi, M ; Ahmadian, M. T ; Sharif University of Technology
    2013
    Abstract
    Human body is constantly under the influence of acceleration loads in environments such as combat flying. This study investigates the effect of body acceleration on human heart function by using finite element analysis. The nonlinear mechanical behavior of myocardium is modeled by Yeoh hyperelastic model. Stress-strain curves of myocardium are determined based on uniaxial compression tests on bovine heart samples. Nonlinear least square curve fitting is conducted in order to obtain material parameters. Heart geometrical modeling in threedimension is done by segmentation of cardiac MRI images. Obtained material coefficients are assigned to the constructed heart model and appropriate pressure... 

    Investigation of the effect of high +Gz accelerations on human cardiac function

    , Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 27 , 2013 , Pages 54-63 ; 17516161 (ISSN) Jamshidi, M ; Ahmadian, M. T ; Sharif University of Technology
    2013
    Abstract
    This study investigates the effect of body acceleration on human cardiac function. Finite element analysis is conducted to simulate geometrical and mechanical properties of human heart. Heart geometrical modeling in three-dimension is performed by segmentation of cardiac MRI images. The nonlinear mechanical behavior of myocardium is modeled by Mooney-Rivlin, Polynomial, Ogden and Yeoh hyperelastic material models. Stress-strain curves of myocardial tissue are obtained from experimental compression tests on bovine heart samples. The experimental results are employed for the evaluation of material coefficients by the nonlinear least squares method. Among hyperelastic models, the Yeoh model... 

    A new coded cooperation scheme for wireless communications and its performance analysis

    , Article International Journal of Wireless Information Networks ; Volume 15, Issue 1 , 2008 , Pages 43-52 ; 10689605 (ISSN) Jamshidi, A ; Nasiri Kenari, M ; Sharif University of Technology
    2008
    Abstract
    We propose a new coded cooperation scheme for wireless communications to obtain transmit diversity in the scenarios that agents such as mobile handsets, sensor network nodes and etc., due to size, power or other constraints, cannot utilize multiple antennas. New scheme supports more than two cooperative users with a relatively low cooperation level. We evaluate the performance of the proposed scheme in a frequency nonselective slow fading channel. For two cooperative users, we provide the exact analytical analysis. However, for more than two users, as the analytical analysis is very complicated, our performance evaluation is based on computer simulations. Our numerical results show that each... 

    Performance analysis of transmitter-side cooperation-receiver-side-relaying schemes for heterogeneous sensor networks

    , Article IEEE Transactions on Vehicular Technology ; Volume 57, Issue 3 , 2008 , Pages 1548-1563 ; 00189545 (ISSN) Jamshidi, A ; Nasiri Kenari, M ; Sharif University of Technology
    2008
    Abstract
    In this paper, we present two physical layer cooperative protocols for heterogeneous sensor networks. There is one cooperator near the transmitter and a second cooperator (as a relay) near the receiver. Although the focus is on heterogeneous sensor networks, the methods can be applied to homogeneous sensor networks as well. Analytical and simulation results show that, under an additive white Gaussian noise channel assumption for the links between the transmitter and its partner and between the receiver and its partner, the proposed protocols achieve a diversity order of three or four by using the amplify-and-forward cooperation strategy and maximal ratio combining in the receiver. In... 

    A novel equation to calculate primary drainage capillary pressure based on a porous plate model: Theory and application

    , Article Chemical Engineering Research and Design ; Volume 195 , 2023 , Pages 247-259 ; 02638762 (ISSN) Omrani, H ; Hajipour, M ; Jamshidi, S ; Behnood, M ; Sharif University of Technology
    Institution of Chemical Engineers  2023
    Abstract
    This study aims to develop an equation for primary drainage capillary pressure as a function of water saturation based on the porous plate model. Several empirical and semiempirical equations are available to calculate Pc-Sw. The results of the previous equations are not ideal, so this is an attempt to present an accurate equation to calculate Pc-Sw based on governing theoretical physical analysis to describe two-phase immiscible displacement flow in porous media. Volumetric flow rates through the core plug and porous plate are applied to calculate the transport phenomena in porous media. The equation is derived from mass and momentum transfer through a core plug, and Darcy's law is applied... 

    A new method in reservoir rock classification in carbonate and sandstone formations

    , Article Journal of Geophysics and Engineering ; Volume 20, Issue 4 , 2023 , Pages 883-900 ; 17422132 (ISSN) Omrani, H ; Hajipour, M ; Jamshidi, S ; Behnood, M ; Sharif University of Technology
    Oxford University Press  2023
    Abstract
    This study aims to improve rock-type classification by analyzing core data based on the water-oil primary drainage capillary pressure method. A modified empirical equation is proposed using permeability, porosity, and irreducible water saturation to classify rock types based on water-oil primary drainage capillary pressure. We used primary drainage capillary pressure data measured in carbonate and sandstone samples in the Ahvaz Asmari and Mansouri oilfields to evaluate the characterization number (Cn) method. This study consists of two main parts. First, the Cn method is introduced to rock typing, and the permeability is calculated from well log data. In the second part, we present rock-type... 

    Privacy-preserving learning using autoencoder-based structure

    , Article 2023 31st International Conference on Electrical Engineering, ICEE 2023 ; 2023 , Pages 893-898 ; 979-835031256-0 (ISBN) Jamshidi, M. A ; Veisi, H ; Mojahedian, M. M ; Aref, M. R ; Sharif University of Technology
    Institute of Electrical and Electronics Engineers Inc  2023
    Abstract
    The need for privacy makes data centers not provide their datasets to inference centers. On the other hand, inference centers need more data to train learning algorithms and provide suitable and acceptable services. Therefore, the existence of a structure that can keep the data confidential while maintaining its usefulness for utility providers is of great importance. In this paper, by modifying the structure of the auto encoder, a method is presented that manages the trade-off between utility and privacy. Moreover, the performance of the proposed method has been evaluated by simulation. © 2023 IEEE  

    Investigating the permeability–porosity relation of percolation-based porous media using the lattice boltzmann method

    , Article Journal of Porous Media ; Volume 20, Issue 10 , 2017 , Pages 899-919 ; 1091028X (ISSN) Foroughi, S ; Masihi, M ; Jamshidi, S ; Pishvaie, M. R ; Sharif University of Technology
    2017
    Abstract
    The semi-empirical Kozeny–Carman (KC) equation is the widely used equation for determining permeability of porous media. Recent studies have shown that KC coefficient (CKC ) is a function of porous media parameters. In this study, the relation between parameters of randomly generated porous media is investigated to improve permeability prediction. In particular, site percolation theory is applied to construct random porous media. The static parameters of porous media, including porosity and specific surface area, are evaluated from porous media structure, and dynamic parameters, tortuosity and permeability, are derived from the results of Lattice Boltzmann fluid flow simulation.... 

    Molecular mechanism of glycosylated IL-1RII counteraction with IL-1RI in regulation of the immune response

    , Article Molecular Simulation ; Volume 49, Issue 16 , 2023 , Pages 1491-1501 ; 08927022 (ISSN) Jamshidi Khameneh, N ; Azimzadeh Irani, M ; Ejtehadi, M. R ; Sharif University of Technology
    Taylor and Francis Ltd  2023
    Abstract
    Interleukin-1 Receptor Type II (IL-1RII) is the decoy receptor of IL-1 cytokines. It down-regulates the immune signalling pathways. There is a competitive behaviour between the IL-1RII and IL-1RI, which is the signalling receptor of the IL-1Rs family. By adopting similarities in structure and specific shared ligands, the two receptors are competing regulators of the immune response. Conformational changes of IL-1RII is a crucial factor in its ligand binding and activation. In addition, dynamics and functionality of the receptor are known to be regulated by glycosylation. Herein, all-atom Molecular Dynamics (MD) simulations were carried out to investigate the dynamics of the apo and... 

    Numerical investigation of nanofluid mixed-convection flow in the entrance region of a vertical channel partially filled with porous medium

    , Article Heat Transfer - Asian Research ; Vol. 43, issue. 7 , November , 2014 , p. 607-627 Hajipour, M ; Dehkordi, A. M ; Jamshidi, S ; Sharif University of Technology
    2014
    Abstract
    In this article, transient two-dimensional mixed convection of nanofluids in the entrance region of a vertical channel has been studied carefully. The geometry under consideration consisted of a parallel-plate channel partly filled with a porous medium with a constant wall temperature. In the free flow region, the two-dimensional flow field has been governed by the Navier-Stokes equations. The general formulation of the momentum equations accounting for the inertial and the viscous effects in the presence of a porous medium has been used. Viscous dissipation effects have also been incorporated in the thermal energy equation. Effects of Brownian diffusion and thermophoresis have also been... 

    Development of an adaptive surrogate model for production optimization

    , Article Journal of Petroleum Science and Engineering ; Volume 133 , September , 2015 , Pages 677-688 ; 09204105 (ISSN) Golzari, A ; Haghighat Sefat, M ; Jamshidi, S ; Sharif University of Technology
    Elsevier  2015
    Abstract
    Recently production optimization has gained increasing interest in the petroleum industry. The most computationally expensive part of the production optimization process is the evaluation of the objective function performed by a numerical reservoir simulator. Employing surrogate models (a.k.a. proxy models) as a substitute for the reservoir simulator is proposed for alleviating this high computational cost.In this study, a novel approach for constructing adaptive surrogate models with application in production optimization problem is proposed. A dynamic Artificial Neural Networks (ANNs) is employed as the approximation function while the training is performed using an adaptive sampling... 

    Application of Hydrated Basil Seeds (HBS) as the herbal fiber on hole cleaning and filtration control

    , Article Journal of Petroleum Science and Engineering ; Volume 152 , 2017 , Pages 212-228 ; 09204105 (ISSN) Movahedi, H ; Vasheghani Farahani, M ; Jamshidi, S ; Sharif University of Technology
    Elsevier B.V  2017
    Abstract
    Application of the fiber contained fluids has been extensively increased in many industries. In the petroleum industry, fibrous fluids are utilized for different applications. For instance, they have been applied in drilling operations for hole cleaning and cutting removal. In this article, the results of the studies performed on the application of Hydrated Basil Seeds (HBS) as the herbal eco-friendly fiber on hole cleaning and filtration control were presented. In order to investigate the application of HBS on hole cleaning, Polyacrylamide (PA) was added to the pure water to provide the base fluid and HBS at different concentrations were suspended in the base fluid and the effect of HBS on... 

    Outage probability analysis of a coded cooperative OFDM system in multipath Rayleigh fading channels

    , Article 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'07, Athens, 3 September 2007 through 7 September 2007 ; December , 2007 ; 1424411440 (ISBN); 9781424411443 (ISBN) Jamshidi, A ; Nasiri Kenari, M ; Taherpour, A ; Sharif University of Technology
    2007
    Abstract
    This paper considers a cooperative space-frequency (SF) coded OFDM system and evaluates its performance over quasi-static frequency selective Rayleigh fading channels. An expression for exact outage error probability is derived and its tight closed form lower bound is presented. The tightness of the lower bound is demonstrated through the Monte Carlo simulations. The asymptotic analysis indicates that the proposed protocol achieves full spatial and frequency diversities available in the cooperative communication system. The theoretical analysis of the proposed space-frequency coded cooperation protocol is further confirmed by computer simulations. © 2007 IEEE  

    Efficient cooperative spectrum sensing in cognitive radio networks

    , Article 18th Annual IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC'07, Athens, 3 September 2007 through 7 September 2007 ; December , 2007 ; 1424411440 (ISBN); 9781424411443 (ISBN) Taherpour, A ; Nasiri Kenari, M ; Jamshidi, A ; Sharif University of Technology
    2007
    Abstract
    Rcent measurements suggest the possibility of sharing spectrum among different parties subject to interference-protection constraints. In order to enable access to an unused licensed spectrum, a secondary user has to monitor licensed bands and opportunistically transmit whenever no primary signal is detected. In this paper, we study spectrum-sharing between a primary licensee and a group of secondary users. The structure of an asymptotically optimum detector based on the measurements of all secondary users is derived and the effect of the quantization error in such a system is evaluated. The results show the superiority of the proposed detector to other schemes. © 2007 IEEE  

    Optimization of HFDS production from date syrup

    , Article International Journal of Engineering, Transactions B: Applications ; Volume 21, Issue 2 , 2008 , Pages 127-134 ; 1728-144X (ISSN) Jamshidi Mokhber, M ; Alemzadeh, I ; Vossoughi, M ; Sharif University of Technology
    Materials and Energy Research Center  2008
    Abstract
    Fructose is utilized as a common sweetener in many food industries. Today, a large amount of HFCS (high fructose corn syrup, an equilibrium mixture of glucose and fructose) is produced by glucose isomerase, immobilized enzymes from corn starch. There are a lot of date palms in Iran. Date is a favorable source of carbohydrates, and a suitable source for HFDS (high fructose date syrup) production. In this investigation, date syrup properties were first determined and the operational conditions for glucose isomerase application were optimized respectively. Ion exchange chromatography has been utilized for carbohydrate separation. Fructose obtained from chromatographic column reached 90 %... 

    The impact of the double cross-phase diffusion mechanism on oil recovery during co2injection into fractured rocks: a simulation study

    , Article ACS Omega ; Volume 7, Issue 25 , 2022 , Pages 21630-21642 ; 24701343 (ISSN) Sistan, M ; Ghazanfari, M. H ; Jamshidi, S ; Sharif University of Technology
    American Chemical Society  2022
    Abstract
    In this research, a new diffusion mechanism called "double cross-phase diffusion"is introduced and applied to simulate the non-equilibrium gas injection process into fractured rocks. This new mechanism represents additional multicomponent gas diffusion into the crude oil through the water phase, existing in porous media as initial water saturation. Therefore, a lab-scale simulator, by implementing the generalized Fick's law of multicomponent diffusion, is developed and used for predicting the experimental data of oil recovery during CO2 injection in chalk fractured rocks in the presence of initial water saturation. The results revealed a significant difference in the oil recovery predicted... 

    Feasibility of a powered knee joint in providing stance and swing phase knee flexion when using a knee-ankle-foot orthosis

    , Article Journal of Prosthetics and Orthotics ; Volume 29, Issue 4 , 2017 , Pages 177-182 ; 10408800 (ISSN) Rafiaei, M ; Arazpour, M ; Bahramizadeh, M ; Farahmand, F ; Jamshidi, N ; Samadian, M ; Sharif University of Technology
    2017
    Abstract
    Background The aim of this study was to develop a new stance control knee-ankle-foot orthosis (SCKAFO) and determine its efficacy on specific spatiotemporal and kinematic parameters. Method Seven healthy volunteer subjects participated in this study. After orthotic gait training, subjects participated in a four-part data collection session that consisted of gait evaluation with normal walking, SCKAFO with locked knee joint, SCKAFO without initial flexion (IF) mode, and SCKAFO with IF mode. Results Walking with any of the control knee-ankle-foot orthoses (KAFOs) produced a significant reduction in walking speed compared with normal walking. There was no significant difference in walking speed... 

    Application of GA in optimization of pore network models generated by multi-cellular growth algorithms

    , Article Advances in Water Resources ; Volume 32, Issue 10 , 2009 , Pages 1543-1553 ; 03091708 (ISSN) Jamshidi, S ; Bozorgmehry Boozarjomehry, R ; Pishvaie, M. R ; Sharif University of Technology
    2009
    Abstract
    In pore network modeling, the void space of a rock sample is represented at the microscopic scale by a network of pores connected by throats. Construction of a reasonable representation of the geometry and topology of the pore space will lead to a reliable prediction of the properties of porous media. Recently, the theory of multi-cellular growth (or L-systems) has been used as a flexible tool for generation of pore network models which do not require any special information such as 2D SEM or 3D pore space images. In general, the networks generated by this method are irregular pore network models which are inherently closer to the complicated nature of the porous media rather than regular...