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The impact of surfactants on wettability change and level of water imbibition in relation to EOR in carbonate reservoirs
, Article Petroleum Science and Technology ; Volume 31, Issue 20 , 2013 , Pages 2098-2109 ; 10916466 (ISSN) ; Bastani, D ; Badakhshan, A ; Sharif University of Technology
2013
Experimental study of the chemical stimulation of Iranian fractured carbonate reservoir rocks as an EOR potential, the impact on spontaneous imbibition and capillary pressure
, Article Scientia Iranica ; Volume 17, Issue 1 C , 2010 , Pages 37-45 ; 10263098 (ISSN) ; Bastani, D ; Badakhshan, A ; Sharif University of Technology
2010
Abstract
Beside their worldwide abundance, oil recovery from fractured carbonate reservoirs is commonly low. Such reservoirs are usually oil-wet, thus, waterflooding leads into early breakthrough and low recovery due to the high conductivity of the fracture network, negative capillary pressure of the matrix and, consequently, the poor spontaneous imbibitions of water from fractures into the matrix during the course of waterflooding. In such problematic reservoirs, changing the wettability of the matrix toward water-wetness can improve spontaneous imbibition by changing the sign and, thus, the direction of capillary forces, resulting in an improvement of waterflood efficiency and, consequently, oil...
Selecting a Surfactant for Wettability Alteration In Iranian Carbonate Reservoirs
, M.Sc. Thesis Sharif University of Technology ; Bastani, Daruoosh (Supervisor) ; Badakhshan, Amir (Supervisor)
Abstract
Fractured carbonate reservoirs are mostly oil-wet to intermediate-wet. Due to the negative capillary pressure of the matrix poor spontaneous imbibition of reservoir brine occurs in such reservoirs, and water flooding leads into early break through due to the high conductivity of the fracture network. Some surfactants have the ability to change the wettability of rock matrix toward water-wet state by adsorbing onto the rock surface. The phenomenon can result in spontaneous imbibition improvement and thereby increasing water flooding efficiency and recovery from fractured carbonate reservoirs. In this thesis the effect of some surfactants on the wettability of Iranian carbonate reservoir rocks...
Significant enhancement in the efficiency of photoconductive antennas using a hybrid graphene molybdenum disulphide structure
, Article Journal of Nanophotonics ; Volume 10, Issue 3 , 2016 ; 19342608 (ISSN) ; Safian, R ; Sharif University of Technology
SPIE
2016
Abstract
We propose a hybrid graphene molybdenum disulphide-based photoconductive antenna to overcome the restrictions of metallic photoconductive antennas and graphene-based photoconductive antennas, simultaneously. The structure is composed of a hybrid graphene-MoS2 strip as the antenna deposited on a low-temperature gallium arsenide substrate. A full-wave electromagnetic solver, namely, high frequency structural simulator (HFSS) is used to analyze the whole structure. It is shown that the proposed photoconductive antenna provides us with not only high input impedance and reconfigurability but also high values of matching efficiency and radiation efficiency. The impact of increasing MoS2 layers on...
A graphene-based THz ring resonator for label-free sensing
, Article IEEE Sensors Journal ; Volume 16, Issue 11 , 2016 , Pages 4338-4344 ; 1530437X (ISSN) ; Safian, R ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
In this paper, we report on a novel resonant THz sensor for label-free analysis. The structure consists of a silicon nitride dielectric ring resonator vertically coupled to a thin layer of graphene strip ring resonator on top. The cladding is assumed to be porous alumina on the top of the graphene strip, which enhances the interaction of the surface plasmon wave and the target molecules. Finite difference time domain analysis is used to systematically design the structure and to investigate the performance of the sensor. Our simulations show that the proposed structure has larger refractive index sensitivity and lower intrinsic quality factor with respect to the similar optical structure. It...
Kinetics of oxygen adsorption on ZnS nanoparticles synthesized by precipitation process
, Article Materials Science- Poland ; Volume 34, Issue 2 , 2016 , Pages 260-265 ; 20831331 (ISSN) ; Sadrnezhad, S. K ; Namivandi Zangeneh, R ; Oghabian, M. A ; Sharif University of Technology
Walter de Gruyter GmbH
2016
Abstract
ZnS nanoparticles were synthesized through a one-step precipitation process. Effect of time and temperature on the formation reaction was investigated. The synthesized samples were characterized by X-ray diffraction (XRD), ultraviolet (UV) visible absorption and photoluminescence (PL) spectrophotometry. Based on XRD and UV-Vis data, the particles produced at 70 °C had a mean particle size of about 5 nm. Increasing time and temperature of the synthesis reaction resulted in photoluminescence intensification. PL spectroscopy helped understanding the adsorption kinetics of oxygen on ZnS nanoparticles during the precipitation synthesis process. Fabrication of ZnS structures with appropriate...
Spatial integration by a dielectric slab and its planar graphene-based counterpart
, Article Optics Letters ; Volume 42, Issue 10 , 2017 , Pages 1954-1957 ; 01469592 (ISSN) ; Khavasi, A ; Sharif University of Technology
2017
Abstract
In this contribution a new approach to perform spatial integration is presented using a dielectric slab. Our approach is indeed based on the fact that the transmission coefficient of a simple dielectric slab at its mode excitation angle matches the Fourier-Green's function of first-order integration. Inspired by the mentioned dielectric-based integrator, we further demonstrate its graphene-based counterpart. The latter is not only reconfigurable but also highly miniaturized in contrast to the previously reported designs [Opt. Commun. 338, 457 (2015)]. Such integrators have the potential to be used in ultrafast analog computation and signal processing. © 2017 Optical Society of America
Synthesizing and staining manganese oxide nanoparticles for cytotoxicity and cellular uptake investigation
, Article Biochimica et Biophysica Acta - General Subjects ; Vol. 1840, Issue. 1 , 2014 , pp. 428-433 ; ISSN: 03044165 ; Oghabian, M. A ; Ahmadi, R ; Shahbazi, N ; Hosseini, H. R. M ; Shanehsazzadeh, S ; Zangeneh, R. N ; Sharif University of Technology
2014
Abstract
Background For decades, contrast agents have been used to reduce longitudinal (T1) or transverse (T2) relaxation times. High toxicity of gadolinium-based contrast agents leads researchers to new T1 contrast agents. Manganese oxide (MnO) nanoparticle (NP) with the lower peril and good enough signal change ability has been offered as a new possibility for magnetic resonance imaging (MRI). Methods The synthesized NPs were investigated for physicochemical and biological properties by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscope, dynamic light scattering (DLS), inductively coupled plasma, enzyme-linked immunosorbent assay, and 3 T magnetic resonance...
Comparative Study on Enhanced Photocatalytic Activity of Visible Light-Active Nanostructures for Degradation of Oxytetracycline and COD Removal of Licorice Extraction Plant Wastewater
, Article Water (Switzerland) ; Volume 15, Issue 2 , 2023 ; 20734441 (ISSN) ; Mousavi, A ; Eskandari, P ; Amarloo, E ; Farghelitiyan, J ; Zamani, M. R ; Sharif University of Technology
MDPI
2023
Abstract
This study evaluates the effects of carbon, nitrogen, and sulfur dopants on the photocatalytic activity of TiO2 for degradation of oxytetracycline (OTC) and chemical oxygen demand (COD) removal from licorice extraction plant wastewater (LEPW). Three novel visible-light-responsive nanostructures, including L-Histidine-TiO2, L-Methionine-TiO2 and L-Asparagine-TiO2, were successfully synthesized. The results showed that the modification of TiO2 with these three amino acids made the catalyst active in the visible light region and reduced the recombination rate of e−/h+ pairs according to PL analysis. The photodegradation efficiency of L-Histidine (2 wt.%)-TiO2 was 100% and 94% for OTC and COD,...
Analog optical computing by half-wavelength slabs
, Article Optics Communications ; Volume 407 , 2018 , Pages 338-343 ; 00304018 (ISSN) ; Khavasi, A ; Rejaei, B ; Sharif University of Technology
Elsevier B.V
2018
Abstract
A new approach to perform analog optical differentiation is presented using half-wavelength slabs. First, a half-wavelength dielectric slab is used to design a first order differentiator. The latter works properly for both major polarizations, in contrast to our previously design based on Brewster effect (Youssefi et al., 2016). Inspired by the proposed dielectric differentiator, and by exploiting the unique features of graphene, we further design and demonstrate a reconfigurable and highly miniaturized differentiator using a half-wavelength plasmonic graphene film. To the best of our knowledge, our proposed graphene-based differentiator is even smaller than the most compact differentiator...
Using super element and p-approximation for free vibration analysis of composite plates
, Article 2004 ASME International Mechanical Engineering Congress and Exposition, IMECE, Anaheim, CA, 13 November 2004 through 19 November 2004 ; Volume 255 , 2004 , Pages 81-84 ; 01608835 (ISSN) ; Ahmadian, M. T ; Ghoreishi, S. R ; Sharif University of Technology
American Society of Mechanical Engineers (ASME)
2004
Abstract
Effective and efficient methods in computational mechanics have been of interest for the designers and engineers in the last decade. A 3D super elements is developed and implemented for the free vibration analysis of the composite plates. These new elements have been constructed by a 2D super elements in the plane direction and p-version finite element in the thickness direction. Results of 2D super elements are comparable to SHELL 63 and results of 3D super elements with cubic polynomial are comparable to SHELL 93. In the thin plates, 2D super element (or SHELL 63) and 3D super elements (or SHELL 93) have same results, but in the thick plates results change drastically. Natural frequencies...
A Petrov-Galerkin finite element method using polyfractonomials to solve stochastic fractional differential equations
, Article Applied Numerical Mathematics ; Volume 169 , 2021 , Pages 64-86 ; 01689274 (ISSN) ; Foroush Bastani, A ; Zohouri Zangeneh, B ; Sharif University of Technology
Elsevier B.V
2021
Abstract
In this paper, we are concerned with existence, uniqueness and numerical approximation of the solution process to an initial value problem for stochastic fractional differential equation of Riemann-Liouville type. We propose and analyze a Petrov-Galerkin finite element method based on fractional (non-polynomial) Jacobi polyfractonomials as basis and test functions. Error estimates in L2 norm are derived and numerical experiments are provided to validate the theoretical results. As an illustrative application, we generate sample paths of the Riemann-Liouville fractional Brownian motion which is of importance in many applications ranging from geophysics to traffic flow in telecommunication...
A Petrov-Galerkin finite element method using polyfractonomials to solve stochastic fractional differential equations
, Article Applied Numerical Mathematics ; Volume 169 , 2021 , Pages 64-86 ; 01689274 (ISSN) ; Foroush Bastani, A ; Zohouri Zangeneh, B ; Sharif University of Technology
Elsevier B.V
2021
Abstract
In this paper, we are concerned with existence, uniqueness and numerical approximation of the solution process to an initial value problem for stochastic fractional differential equation of Riemann-Liouville type. We propose and analyze a Petrov-Galerkin finite element method based on fractional (non-polynomial) Jacobi polyfractonomials as basis and test functions. Error estimates in L2 norm are derived and numerical experiments are provided to validate the theoretical results. As an illustrative application, we generate sample paths of the Riemann-Liouville fractional Brownian motion which is of importance in many applications ranging from geophysics to traffic flow in telecommunication...
Beam focusing using two-dimensional graphene-based meta-reflect-array
, Article 24th Iranian Conference on Electrical Engineering, ICEE 2016, 10 May 2016 through 12 May 2016 ; 2016 , Pages 613-616 ; 9781467387897 (ISBN) ; Abdollahramezani, S ; Arik, K ; Khavasi, A ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2016
Abstract
A highly efficient two-dimensional meta-reflect-array manipulating the phase and amplitude of far-infrared electromagnetic wave is proposed. The reflect array consists of patterned graphene nano-disks resides on a subwavelenght thick optical cavity to enhance the interaction of electromagnetic wave. It is shown that the reflected wave from each unit cell can almost cover the 2π range phase shift by changing the radius of the graphene nano-disks while at the same time maximizes its amplitude. Proposing a transmission line model for the proposed structure, we realize a meta lens as a flat optics functionality. © 2016 IEEE
Stationarity of the Solution for the Semilinear Stochastic Integral Equation on the Whole Real Line
, Article Springer Proceedings in Mathematics and Statistics ; Volume 34 , 2013 , Pages 315-331 ; 21941009 (ISSN) ; 9781461459057 (ISBN) ; Sharif University of Technology
Springer New York LLC
2013
Abstract
In this article we prove the stationarity of the solution of the H-valued integral equation, where H is a real separable Hilbert space. In this equation, U(t) is a semigroup generated by a strictly negative definite, self-adjoint unbounded operator A, such that A-1 is compact and f is of monotone type and is bounded by a polynomial and V (t) is a cadlag adapted stationary process
Effects of COVID-19-related psychological distress and anxiety on quality of sleep and life in healthcare workers in Iran and three European countries
, Article Frontiers in Public Health ; Volume 10 , 2022 ; 22962565 (ISSN) ; Tahvilian, P ; Koohestani, S ; Maghooli, K ; Jafarnia Dabanloo, N ; Sarhangi Kadijani, M ; Jahantigh, S ; Zangeneh Soroush, M ; Saliani, A ; Sharif University of Technology
Frontiers Media S.A
2022
Abstract
Introduction: The COVID-19 pandemic has considerably affected human beings most of whom are healthcare workers (HCWs) combating the disease in the front line. Methods: This cross-sectional study aims to explore the effects of stress and anxiety caused by COVID-19 on the quality of sleep and life in HCWs, including physicians, nurses, and other healthcare staff. In this global study, we asked 1,210 HCWs (620 and 590 volunteers from Iran and European countries, including Germany, the Netherlands, and Italy, respectively), who age 21–70, to participate in the test. Several measures of COVID-related stress, anxiety, sleep, and life quality, including the 12-item General Health Questionnaire...
Effects of Lateral Spreading on Two 2×2 Pile Groups (with and Without Lumped Mass) Using Shaking Table and Laminar Shear Box
, M.Sc. Thesis Sharif University of Technology ; Haeri, Mohsen (Supervisor)
Abstract
Lateral spreading is the downstream movement of mild slopes or free fronts occurring due to soil liquefaction during a dynamic loading such as an earthquake. The magnitude of this movement can be from a few centimeters to tens of meters depending on parameters such as slope length, soil type, cyclic loading intensity, etc. Large displacements caused by this phenomenon can cause severe damage to some structures and infrastructures located in the direction of their movement. Numerous articles and reports of damage caused by the lateral spreading of soil have been presented during several earthquakes. Understanding this phenomenon and observing and testing its effective parameters can help...
A hybrid machine learning and optimization model to minimize the total cost of BRT brake components
, Article Journal of Advanced Transportation ; Volume 2021 , 2021 ; 01976729 (ISSN) ; Shams Gharneh, N ; Arjomandi Nezhad, A ; Hassannayebi, E ; Sharif University of Technology
Hindawi Limited
2021
Abstract
Public transport is amongst critical infrastructures in modern cities, especially megacities, home to millions of people. The reliability of these systems is highly crucial for both citizens and service providers. If service providers overlook system reliability, a considerable amount of expenses will be wasted. Several factors such as vehicle failure, accident, lack of budget weather factors, and traffic congestion cause unreliability, among which vehicle failure plays a prominent role. The brake system is the most vulnerable and vital component of a public transportation bus. Brake reliability depends on driver's expertise, component quality, passenger loading, line situation, etc....
Existence and measureability of the solution of the stochastic differential equations driven by fractional brownian motion
, Article Bulletin of the Iranian Mathematical Society ; Volume 35, Issue 2 , 2009 , Pages 47-68 ; 10186301 (ISSN) ; Zohori Zangeneh, B ; Sharif University of Technology
2009
Abstract
Here, the existence and measurability of solutions for stochastic differential equations driven by fractional Brownian noise with Hurst parameter greater than 1 2 is proved. Our method is based on approximating the main equation by delayed equations as in Peano's method in ODEs. This method makes the proofs easier and needs weaker assumptions for the existence part, compared with the previous works as in [25]. In addition the constructive nature of the proofs helps to develop some numerical methods for solving such SDEs. © 2009 Iranian Mathematical Society
Scheduling and operation of virtual power plants: technical challenges and electricity markets
, Article Scheduling and Operation of Virtual Power Plants: Technical Challenges and Electricity Markets ; 2022 , Pages 1-425 ; 9780323852685 (ISBN); 9780323852678 (ISBN) ; Moeini Aghtaie, M ; Sharif University of Technology
Elsevier
2022
Abstract
Scheduling and Operation of Virtual Power Plants: Technical Challenges and Electricity Markets provides a multidisciplinary perspective on recent advances in VPPs, ranging from required infrastructures and planning to operation and control. The work details the required components in a virtual power plant, including smartness of power system, instrument and information and communication technologies (ICTs), measurement units, and distributed energy sources. Contributors assess the proposed benefits of virtual power plant in solving problems of distributed energy sources in integrating the small, distributed and intermittent output of these units. In addition, they investigate the likely...