Privatization and Firm Performance: Evidence from Iran`s Privatization Experience

, M.Sc. Thesis Sharif University of Technology Bidhendi, Reza (Author) ; Ebrahimnejad, Ali (Supervisor)

Abstract

Privatization in Iran was primarily driven by the 2004 amendment to the Article 44 of the Iranian Constitution. Improving firms' efficiency is cited as the key goal of the privatization program. The two prominent characteristics of the privatization program in Iran are complex ownership structure and transferring ownership from the government to government-affiliated institutions and organizations. For these reasons, the consequences of privatization in Iran may differ from those of other countries. Therefore, this study explores the relation between privatization and firm performance, as measured by firm efficiency, labor efficiency, investment, and the number of employees. As a significant...

A Carbonate Reservoir Characterization Using AVO Analysis on 3D Seismic Data

, Ph.D. Dissertation Sharif University of Technology Hassanzadeh Azar, Javid (Author) ; Pishvaie, Mahmoud Reza (Supervisor) ; Javaherian, Abdolrahim (Supervisor) ; Nabi Bidhendi, Majid (Co-Advisor)

Abstract

In this project, some issues facing the application of AVO in carbonate reservoirs were studied,reviewed and discussed: physical relationships between elastic and reservoir rock properties to estimate compressional and shear wave velocities both on core measurements and well logging data, sensitivity analysis for Gassmann‐Biot and Kuster‐Toksoz rock physics models on the representative carbonate samples, lithology discrimination and reservoir characterization in carbonate intervals using AVO seismic attributes and specifically LambdaRho‐MuRho approach.The studied area (Azadegan Oil Field) is an area about 1174 km2 of 3D seismic data and was containing of six wells in the time of study. In...

On the capacity region of asymmetric gaussian two-way line channel

, Article IEEE Transactions on Communications ; Volume 64, Issue 9 , 2016 , Pages 3669-3682 ; 00906778 (ISSN) Ghasemi Goojani, S ; Karimi Bidhendi, S ; Behroozi, H ; Sharif University of Technology

Institute of Electrical and Electronics Engineers Inc 2016

Abstract

Lattice codes are known to outperform random codes for certain networks, especially in the Gaussian two-way relay channels (GTWRCs) where lattice codes are able to exploit their linearity. As an extension of the GTWRC, in this paper, we consider the asymmetric Gaussian two-way line network where two nodes exchange their messages through multiple relays. We first investigate the capacity region of the full-duplex two-way two-relay line network. The results can be extended to an arbitrary number of relays and to half-duplex scenarios. This channel consists of four nodes: 1 ↔ 2 ↔ 3 ↔ 4, where nodes 1 and 4 with the help of two full-duplex relays, i.e., nodes 2 and 3, exchange their messages...

QSRR study of psychiatric drugs using classification and regression trees combined with adaptive neuro-fuzzy inference system

, Article QSAR and Combinatorial Science ; Volume 27, Issue 6 , 2008 , Pages 729-739 ; 1611020X (ISSN) Jalali Heravi, M ; Shahbazikhah, P ; Ghadiri Bidhendi, A ; Sharif University of Technology

2008

Abstract

A new Quantitative Structure-Retention Relationship (QSRR) approach was carried out for prediction of gas-liquid retention times of 124 psychiatric drugs in whole blood on fused-silica capillary column coated with crosslinked methylsilicone with nitrogen-phosphorus detection. After screening the descriptors, a total of 699 topological, geometric, and electronic descriptors (zero-to three-dimensional) representing various structural characteristics were calculated for each molecule in the dataset. Combined method of Classification and Regression Tree (CART) as a feature selection method for the extraction of four relevant descriptors and Adaptive Neuro-Fuzzy Inference System (ANFIS) as a...

Introducing a method for calculating water saturation in a carbonate gas reservoir

, Article Journal of Natural Gas Science and Engineering ; Volume 70 , 2019 ; 18755100 (ISSN) Movahhed, A ; Nabi Bidhendi, M ; Masihi, M ; Emamzadeh, A ; Sharif University of Technology

Elsevier B.V 2019

Abstract

Cementation factor greatly affects water saturation estimation. Factors such as depositional environment, diagenesis and depositional architecture make the estimation of water saturation a big challenge in carbonate reservoirs. The current study is introduced a method for calculating cementation factor in Archie formula. First, (MRGC) technique was applied on the (NMR) logging parameters along with (NDS) data to obtain the optimum number of clustering. After that, fuzzy logic method was applied on conventional log parameters obtained from the wells without any NMR log data. In the third part of the study, a novel crossplot introduced including compressional to shear-wave velocity ratio...

An optimal integrated power and water supply planning model considering Water-Energy-Emission nexus

, Article Energy Conversion and Management ; Volume 277 , 2023 ; 01968904 (ISSN) Afsari Mamaghani, F ; Omidvar, B ; Avami, A ; Nabi Bidhendi, G ; Sharif University of Technology

Elsevier Ltd 2023

Abstract

Water and energy are the major factors in the new United Nations Sustainable Development Goals. Sustainable conversion and management in the secure supply of increasing demand for water and electricity is a challenging concern. It is recently complicated due to economic development, population growth, resource depletion, and climate change, which requires a simultaneous progressive planning. Since energy and water systems are instinctively interdependent and mutually interacted (known as nexus), this paper employed an integrated solution-based method. A bottom-up optimization model is developed considering Water-Energy-Emission Nexus approach for both power and water sectors. The model...

Integrated seismic attributes to characterize a widely distributed carbonate clastic deposit system in khuzestan province, SW Iran

, Article Journal of Geophysics and Engineering ; Volume 6, Issue 2 , 2009 , Pages 162-171 ; 17422132 (ISSN) Hassanzadeh Azar, J ; Nabi Bidhendi, M ; Javaherian, A ; Pishvaie, M. R ; Sharif University of Technology

2009

Abstract

Integrated seismic attributes, coherency, acoustic impedance (AI), lambda-rho (λρ) and mu-rho (μρ), were used to delineate and to characterize a complex regional channel deposition system in a carbonate reservoir interval in the upper part of the Sarvak Formation. The study area incorporates three adjacent oil fields in SW Iran (Khuzestan Province) covered by three individual 3D seismic surveys having a total area of about 2800 km 2. We generated a regional horizon-based coherency cube using these three seismic surveys. This revealed a carbonate clastic deposition channelling system over the entire study area. We characterized this channel deposition system in agreement with regional...

An approach to defining tortuosity and cementation factor in carbonate reservoir rocks

, Article Journal of Petroleum Science and Engineering ; Volume 60, Issue 2 , 2008 , Pages 125-131 ; 09204105 (ISSN) Hassanzadeh Azar, J ; Javaherian, A ; Pishvaie, M. R ; Nabi Bidhendi, M ; Sharif University of Technology

2008

Abstract

Tortuosity and cementation factor are two critical parameters that significantly affect estimates of reservoir properties. Tortuosity factor can be used to estimate permeability using the Carman-Kozeny equation and is an important parameter for formation resistivity factor calculation using a modified version of Archie's formula. It is also used to predict water saturation of reservoir rocks. Tortuosity as an input parameter in Biot's equation can be used to estimate velocity dispersion. In this work, based on the Generalized Archie Equation Curve Fitting (GAECF), tortuosity and cementation factor are determined for selected intervals in a carbonate reservoir. Formation resistivity factor...

Quantitative Structure - Retention Relationship study of benzodiazepines using adaptive neuro fuzzy inference system as feature selection method

, Article QSAR and Combinatorial Science ; Volume 27, Issue 4 , 2008 , Pages 407-416 ; 1611020X (ISSN) Jalali Heravi, M ; Kyani, A ; Afsari Mamaghani, S ; Ghadiri Bidhendi, A ; Sharif University of Technology

2008

Abstract

A Quantitative Structure-Retention Relationship (QSRR) study of 32 benzodiazepines is performed in this work. Two feature selection methods of Adaptive Neuro Fuzzy Inference System (ANFIS) and a stepwise regression approach adopted for the Multiple Linear Regressions (MLR) were used to predict the Liquid Chromatography-Mass Spectrometry (LC-MS) Retention Time (RT) of these compounds on a Xterra MS C-18 stationary phase. ANFIS and MLR methods were used as variable selection tools and a neural network was employed for predicting the RTs. Tbree descriptors of 3D-MoRSE-signal 06/weighted by atomic polarizabilities (Mor06p), Radial Distribution Function-1.0/weighted by atomic van der Waals...

Synthesis of TiO2/ZnO electrospun nanofibers coated-sewage sludge carbon for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters

, Article Journal of Dispersion Science and Technology ; Volume 42, Issue 6 , January , 2020 , Pages 802-812 Khosravi, M ; Maddah, A. S ; Mehrdadi, N ; Bidhendi, G. N ; Baghdadi, M ; Sharif University of Technology

Taylor and Francis Inc 2020

Abstract

The nanofibers prepared by electrospinning process have high potential for the removal of toxic matters from wastewaters. In the present study, the titanium dioxide and titanium dioxide/zinc oxide (TiO2/ZnO) nanofibers prepared by electrospinning technique were coated on the sewage sludge carbon (SSC) surface for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters of Iran. The synthesized adsorbents were characterized using XRD, SEM and EDX analysis. The effect of adsorbent type, pH, adsorbent dosage, contact time and initial concentrations of Ni(II), Cu(II) and COD on the adsorption capacity of synthesized SSC/TiO2 and SSC/TiO2/ZnO nanofibrous adsorbents...

Synthesis of TiO2/ZnO electrospun nanofibers coated-sewage sludge carbon for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters

, Article Journal of Dispersion Science and Technology ; Volume 42, Issue 6 , 2021 , Pages 802-812 ; 01932691 (ISSN) Khosravi, M ; Maddah, A. S ; Mehrdadi, N ; Bidhendi, G. N ; Baghdadi, M ; Sharif University of Technology

Bellwether Publishing, Ltd 2021

Abstract

The nanofibers prepared by electrospinning process have high potential for the removal of toxic matters from wastewaters. In the present study, the titanium dioxide and titanium dioxide/zinc oxide (TiO2/ZnO) nanofibers prepared by electrospinning technique were coated on the sewage sludge carbon (SSC) surface for adsorption of Ni(II), Cu(II), and COD from aqueous solutions and industrial wastewaters of Iran. The synthesized adsorbents were characterized using XRD, SEM and EDX analysis. The effect of adsorbent type, pH, adsorbent dosage, contact time and initial concentrations of Ni(II), Cu(II) and COD on the adsorption capacity of synthesized SSC/TiO2 and SSC/TiO2/ZnO nanofibrous adsorbents...

Enhancing acid fracture design in carbonate formation using a dynamic up-scaling procedure to convert discrete fracture network to dual continuum

, Article Petroleum Science and Technology ; Volume 40, Issue 18 , 2022 , Pages 2284-2304 ; 10916466 (ISSN) Kasiri Bidhendi, M. R ; Khorsand Movaghar, M. R ; Humand, M ; Bazargan, M ; Sharif University of Technology

Taylor and Francis Ltd 2022

Abstract

For a low-permeability carbonate formation, the acid fracture process is simulated through coupling a commercial acid fracture simulator (GOHFER) to a finite volume reservoir simulator (IMEX). Unlike LGR (Local grid refinement) approach that suffers from severe convergence problems, a dynamic up-scaling procedure is employed to convert the discrete fracture network (DFN) model into a dual continuum model for our simulation. In this paper, multiple simulations are used to optimize the acid fracture schedule parameters, such as fluid volume, flow rate, perforation location, number of injection steps, and acid type, in order to maximize the effective fracture length. For four points perforation...

Simulation of the Effect of Acid Fracturing on the Production of a Well in a Gas Condensate Reservoir

, M.Sc. Thesis Sharif University of Technology Kasiri Bidhendi, Mohammad Reza (Author) ; Masihi, Mohsen (Supervisor) ; Bazargan, Mohammad (Supervisor)

Abstract

Many of gas condensate reservoirs, including rich gas and lean gas, face with fast well productivity decline. The origin of this problem is condense accumulation around the well bore which known as condensate blockage. There are different condensate blockage mitigation methods, one of which is acid fracturing that is suitable for tight carbonate reservoirs with low KH. Acid fracturing simulation is high difficult and have not been undertaken a study that can adopt with experimental and field test results, so researchers usually use practical method and many developed software in this area use correlation form laboratory data. However, the literature show that experimental results can just...

Adsorption of petroleum monoaromatics from aqueous solutions using granulated surface modified natural nanozeolites: Systematic study of equilibrium isotherms

, Article Water, Air, and Soil Pollution ; Volume 217, Issue 1-4 , 2011 , Pages 611-625 ; 00496979 (ISSN) Seifi, L ; Torabian, A ; Kazemian, H ; Bidhendi, G. N ; Azimi, A. A ; Charkhi, A ; Sharif University of Technology

2011

Abstract

Petroleum monoaromatics including benzene, toluene, ethylbenzene, and xylenes (BTEX) are among the notorious volatile organic compounds that contaminate water and soil. In this study, a surfactant- modified natural zeolite and its relevant granulated nanozeolites were evaluated as potential adsorbents for removal of petroleum monoaromatics from aqueous solutions. All experiments performed in batch mode at constant temperature of 20°C and pH of 6.8 for 48 h. The results revealed that the amount of BTEX uptake on granulated zeolites nanoparticles were remarkably higher than the parent micron size natural zeolite (in the order of four times). The isotherms data were analyzed using five models...

Selection of wastewater treatment process based on the analytical hierarchy process and fuzzy analytical hierarchy process methods

, Article International Journal of Environmental Science and Technology ; Volume 8, Issue 2 , March , 2011 , Pages 267-280 ; 17351472 (ISSN) Karimi, A. R ; Mehrdadi, N ; Hashemian, S. J ; Nabi Bidhendi, G. R ; Tavakkoli Moghaddam, R ; Sharif University of Technology

2011

Abstract

This paper presents an application of the analytical hierarchy process and fuzzy analytical hierarchy process methods for selecting the best wastewater treatment process. The analytical hierarchy process is one of the best ways for deciding among the complex criteria structure in different levels, and the fuzzy analytical hierarchy process is a synthetic extension of the classical method when the fuzziness of the decision makers are considered. After reviewing aerobic treatment processes operated in Iran's industrial estates and determining the main criteria used for treatment process evaluation, they are arranged in a hierarchy structure. Selection of the best wastewater treatment process...

Selection of wastewater treatment process based on the analytical hierarchy process and fuzzy analytical hierarchy process methods

, Article Iranian Journal of Environmental Health Science and Engineering ; Volume 8, Issue 2 , 2011 , Pages 267-280 ; 17351979 (ISSN) Karimi, A. R ; Mehrdadi, N ; Hashemian, S. J ; Nabi Bidhendi, G. R ; Moghaddam, R. T ; Sharif University of Technology

2011

Abstract

This paper presents an application of the analytical hierarchy process and fuzzy analytical hierarchy process methods for selecting the best wastewater treatment process. The analytical hierarchy process is one of the best ways for deciding among the complex criteria structure in different levels, and the fuzzy analytical hierarchy process is a synthetic extension of the classical method when the fuzziness of the decision makers are considered. After reviewing aerobic treatment processes operated in Iran's industrial estates and determining the main criteria used for treatment process evaluation, they are arranged in a hierarchy structure. Selection of the best wastewater treatment process...

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...