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Analysis of Creep Behavior and Stability of Underground Fuel Storage in Rock Salt
, M.Sc. Thesis Sharif University of Technology ; Sadaghiani, Mohammadhosein (Supervisor)
Abstract
The purpose of this study is to analyze the stability and creeping behavior of rock salt in underground gas and oil reservoirs. Preparation of natural salt caverns and operating them can manipulate the initial state of previously existed stress and to produce deviatoric stresses around the cavern. New state of stress and with creeping behavior of rock salt, causes a significant decrease in cavern’s volume and damages the surrounding area. Reduction of internal minimum pressure of cavern, increases the intensity of mentioned problems. Geometrical characteristics of cavern can also be significantly effective in the magnitude of damages around the reservoir. For instance, Deflection of cavern...
Investigation of the Reaction of Dithiocarbamic Acid Salts with Carbonyl Compounds (Ketones and Aldehydes), Epoxides and Ortho Esters
, M.Sc. Thesis Sharif University of Technology ; Mahmoodi Hashemi, Mohammed (Supervisor) ; Ziyaei Halimehjani, Azim (Co-Advisor)
Abstract
In the first section, for the first time, a reaction of dithiocarbamic acid salts with carbonyl compounds has been investigated in the presence of BF3.OEt2. The reaction is temperature dependent meaning that the reaction gives two different products at low and high temperatures. At 15-20 0C, the 2-iminium-1,3-dithietane is the main product.As the reaction temperature goes up, formation of gem-bis(dithiocarbamates) is dominant.In addition, deprotection of gem-bis(dithiocarbamates) was investigated by using of nitric acid as the only deprotecting agent. The structure of a 2-iminium-1,3-dithietane was confirmed by X-ray crystallographic analysis.
In the second and third sections, in our aim...
In the second and third sections, in our aim...
Theoretical Analysis of the Electrochemistry and Power Generation in Thermally Activated Batteries
, M.Sc. Thesis Sharif University of Technology ; Gobal, Fereydoun (Supervisor)
Abstract
Study the potential and internal resistance of the electrochemical cells in different states of charge are important for practical and usage. Measurement of these parameters in an electrochemical cell is inseparably bound to the electrochemical resistance, temperature and also geometric states of different parts of the cell. In This project we focus on power and resistance of one kind of batteries called thermally activated batteries. These batteries are active after receiving heat and they are inactive at room temperature. Two of the most important models of these batteries that are discussed in this project are LiSi/ LiCl- KCl / FeS2 battery ( with liquid - molten salt electrolyte ) and...
Efficient imidazolium salts for palladium-catalyzed Mizoroki-Heck and Suzuki-Miyaura cross-coupling reactions
, Article Chinese Chemical Letters ; Volume 24, Issue 5 , 2013 , Pages 433-436 ; 10018417 (ISSN) ; Bagherzadeh, M ; Rostamnia, S ; Sharif University of Technology
2013
Abstract
The system, Pd(OAc)2/imidazolium salts (L2), was found as an efficient catalyst in the Heck coupling reaction of olefins with aryl halides and Suzuki reactions of various aryl halides with aryl boronic acids under aerobic condition. This catalytic system demonstrates great tolerance to a wide range of groups on all substrates of aryl halides, alkenes and aryl boronic acids
Denaturation of Drew-Dickerson DNA in a high salt concentration medium: Molecular dynamics simulations
, Article Journal of Computational Chemistry ; Volume 32, Issue 16 , September , 2011 , Pages 3354-3361 ; 01928651 (ISSN) ; Parsafar, G. A ; Abroshan, H ; Akbarzadeh, H ; Sharif University of Technology
2011
Abstract
We have performed molecular dynamics simulation on B-DNA duplex (CGCGAATTGCGC) at different temperatures. The DNA was immerged in a salt-water medium with 1 M NaCl concentration to investigate salt effect on the denaturation process. At each temperature, configurational entropy is estimated using the covariance matrix of atom-positional fluctuations, from which the melting temperature (T m) was found to be 349 K. The calculated configuration entropy for different bases shows that the melting process involves more peeling (including fraying from the ends) conformations, and therefore the untwisting of the duplex and peeling states form the transition state of the denaturation process. There...
Effect of road salts on the hydro-mechanical behavior of unsaturated collapsible soils
, Article Transportation Geotechnics ; Volume 17 , 2018 , Pages 77-90 ; 22143912 (ISSN) ; Haeri, S. M ; Yazdani Cherati, D ; Ahmadi Givi, F ; Kabiri Tadi, M ; Hashemi, A. H ; Chiti, N ; Qahremani, F ; Sharif University of Technology
Elsevier Ltd
2018
Abstract
Hydro-mechanical behavior of unsaturated collapsible soils can be drastically affected by saline infiltrations. Saline infiltrations into the underlain soil layers of the urban transportation and lifelines due to deicing or existence of traffic pollutants has been a common issue of concern for years in many countries. Additionally, many reports have been published so far, indicating the construction of roads and railways on unsaturated collapsible soils. In this research, hydro-mechanical characteristics of an unsaturated collapsible loessial soil diluted with saturated solutions of three different salts that are frequently involved in transportation infrastructure (namely NaCl, CaCl2 and...
Casing failure in salt rock: numerical investigation of its causes
, Article Rock Mechanics and Rock Engineering ; Volume 53, Issue 9 , 2020 , Pages 3903-3918 ; Pak, A ; Sharif University of Technology
Springer
2020
Abstract
Numerous cases of casing failure have been reported worldwide. Depletion-induced compaction is one of the main factors that may cause casing failure. Stress perturbation in salt layers may accommodate rock flow which endangers the stability of cased wells. Besides, poor cementing jobs are recognized as one of the wellbore instability causes. These factors need to be considered to determine the mechanism behind the casing failure. In this study, the creep behavior of the caprock salt layer in the southwest Iranian oil fields is experimentally studied through a number of creep tests under conditions of elevated temperature and pressure. Then, a three-dimensional finite element analysis is...
De novo RNA sequencing analysis of Aeluropus littoralis halophyte plant under salinity stress
, Article Scientific Reports ; Volume 10, Issue 1 , 4 June , 2020 ; Nematzadeh, G. A ; Pakdin Parizi, A ; Bakhtiarizadeh, M. R ; Motahari, S. A ; Sharif University of Technology
Nature Research
2020
Abstract
The study of salt tolerance mechanisms in halophyte plants can provide valuable information for crop breeding and plant engineering programs. The aim of the present study was to investigate whole transcriptome analysis of Aeluropus littoralis in response to salinity stress (200 and 400 mM NaCl) by de novo RNA-sequencing. To assemble the transcriptome, Trinity v2.4.0 and Bridger tools, were comparatively used with two k-mer sizes (25 and 32 bp). The de novo assembled transcriptome by Bridger (k-mer 32) was chosen as final assembly for subsequent analysis. In general, 103290 transcripts were obtained. The differential expression analysis (log2 FC > 1 and FDR < 0.01) showed that 1861...
Electrodeposition of aluminum from molten AlCl3-NaCl-KCl mixture
, Article Journal of Applied Electrochemistry ; Volume 36, Issue 10 , 2006 , Pages 1169-1173 ; 0021891X (ISSN) ; Mahjani, M.G ; Gobal, F ; Danaee, I ; Sharif University of Technology
2006
Abstract
Electrochemical deposition of aluminum from basic and acidic molten NaCl-KCl-AlCl3 mixture on a graphite electrode at 140 °C was studied by voltammetry, chronopotentiometry and constant current deposition. The deposition of aluminum was found to proceed via a nucleation/growth mechanism in basic melt, while it was found to be diffusion controlled in acidic melt. The diffusion coefficient calculated for Al2Cl- 7 ions in acidic melt by voltammetry was in agreement with the deductions of voltammetry. The morphology of the aluminum deposits was examined using a metallographic microscope and by SEM. It was shown that, depending on the current density (c.d.) and AlCl3 concentration (acidic or...
Salting-out effect of NaCl and KCl on the ternary LLE data for the systems of (water + propionic acid + isopropyl methyl ketone) and of (water + propionic acid + isobutyl methyl ketone)
, Article Journal of Chemical Thermodynamics ; Volume 36, Issue 4 , 2004 , Pages 341-348 ; 00219614 (ISSN) ; Mohsen Nia, M ; Taghikhani, V ; Behpoor, M ; Aghahosseini, M ; Sharif University of Technology
Academic Press
2004
Abstract
(Liquid + liquid) equilibrium (LLE) data were obtained for the ternary systems of {water + propionic acid (PA) + isopropyl methyl ketone (IPMK.)} and of {water + PA + isobutyl methyl ketone (IBMK)} at atmospheric pressure and temperatures (303.15, 313,15 and 323.15) K, respectively. The effect of electrolytes on the LLE data for the ternary systems was also investigated. The results obtained from the experiments showed that the electrolytes studied in this work, i.e., NaCl and KCl significantly affect the solubility of PA in the organic solvents used in the experiments. The results also showed that the distribution coefficients for PA and the selectivity of the solvents in extracting PA,...
, Ph.D. Dissertation Sharif University of Technology ; Matloubi Moghaddam, Firouz (Supervisor)
Abstract
We have reported a new and efficient synthesis of a broad spectrum of heterotetracyclic benzoxazocines via unique tandem 1,3-dinucleophilic addition of different bifunctional nucleophiles to quinolinium and isoquinolinium salts. The reaction generally involves the initial addition of nucleophiles to quinolinium salts to form enamine intermediate which can be trapped by intramolecular O/S-alkylation of nucleophiles. In the third part, as continues, we have reported another method which consists of Anthocyanidins and Thioindoles by using water and acetic acid as the solvent. This protocol is a very mild and simple method for construction of eight-membered ring in fused heterocycles in a...
Fourier series solution for an anisotropic and layered configuration of the dispersive Henry Problem
, Article 25th Salt Water Intrusion Meeting, SWIM 2018, 17 June 2018 through 22 June 2018 ; Volume 54 , 2018 ; 22671242 (ISSN) ; Fahs, M ; Belfort, B ; Ataie Ashtiani, B ; Simmons, C. T ; Sharif University of Technology
EDP Sciences
2018
Abstract
Henry Problem (HP) still plays an important role in benchmarking numerical models of seawater intrusion (SWI) as well as being applied to practical and managerial purposes. The popularity of this problem is due to having a closed-form semi-analytical (SA) solution. The early SA solutions obtained for HP were limited to extensive assumptions that restrict its application in practical works. Several further studies expended the generality of the solution by assuming lower diffusion coefficients or including velocity-dependent dispersion in the results. However, all these studies are limited to homogeneous and isotropic domains. The present work made an attempt to improve the reality of the SA...
A fast iterative method for removing sparse noise from sparse signals
, Article 7th IEEE Global Conference on Signal and Information Processing, GlobalSIP 2019, 11 November 2019 through 14 November 2019 ; 2019 ; 9781728127231 (ISBN) ; Zarmehi, N ; Marvasti, F ; Gazor, S ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2019
Abstract
Reconstructing a signal corrupted by impulsive noise is of high importance in several applications, including impulsive noise removal from images, audios and videos, and separating texts from images. Investigating this problem, in this paper we propose a new method to reconstruct a noise-corrupted signal where both signal and noise are sparse but in different domains. We apply our algorithm for impulsive noise (Salt- and-Pepper Noise (SPN) and Random-Valued Impulsive Noise (RVIN) removal from images and compare our results with other notable algorithms in the literature. Simulation indicates show that our algorithm is not only simple and fast, but also it outperforms the other...
Experimental investigation of dynamic asphaltene adsorption on calcite packs: The impact of single and mixed-salt brine films
, Article Canadian Journal of Chemical Engineering ; Volume 97, Issue 7 , 2019 , Pages 2028-2038 ; 00084034 (ISSN) ; Ghotbi, C ; Jafari Behbahani, T ; Bakhshi, P ; Sharif University of Technology
Wiley-Liss Inc
2019
Abstract
In this study, the dynamic adsorption of asphaltene on a calcite surface is investigated. This study investigates the effect of mixed-salt brines on asphaltene adsorption. The results of this work can facilitate the understanding of the complex wettability behaviour of carbonate reservoirs. All experiments were performed in porous media, which were sand-packs filled with calcite powder, to study the influence of the type and concentration of salt on adsorption. The experiments were conducted with asphaltene concentration of 500 mg/L for brines of NaCl, Na2SO4, and a mixture of the two at various ionic strengths. In addition, two tests were performed with an asphaltene concentration of 2000...
Theoretical and industrial aspects of amine reclaiming unit to separate heat stable salts
, Article Separation and Purification Technology ; Volume 237 , 2020 ; Moradi, M ; Rostami, A ; Azizpour, H ; Sharif University of Technology
Elsevier B.V
2020
Abstract
In this study, a thermal vacuum distillation amine reclaimer unit was industrially and theoretically investigated to remove HSS from a salty amine stream. The presence of ions in the salty amine solution limits application of computer simulation tools to study the process. A thermodynamic equivalent scheme was used for thermal vacuum distillation amine reclaimer, for first time and the simulation results were totally conformed to experimental and industrial data. The effect of critical parameters namely reclaimer vacuum pressure, re-circulation flow rate and HSS amount on performance of thermal amine reclaiming was investigated based on increasing amine solution quality, amine recovery,...
A fast iterative method for removing impulsive noise from sparse signals
, Article IEEE Transactions on Circuits and Systems for Video Technology ; Volume 31, Issue 1 , 2021 , Pages 38-48 ; 10518215 (ISSN) ; Zarmehi, N ; Kangarshahi, E. A ; Abin, H ; Marvasti, F ; Sharif University of Technology
Institute of Electrical and Electronics Engineers Inc
2021
Abstract
In this paper, we propose a new method to reconstruct a signal corrupted by noise where both signal and noise are sparse but in different domains. The main contribution of our algorithm is its low complexity; it has much lower run-time than most other algorithms. The reconstruction quality of our algorithm is both objectively (in terms of PSNR and SSIM) and subjectively better or comparable to other state-of-the-art algorithms. We provide a cost function for our problem, present an iterative method to find its local minimum, and provide the analysis of the algorithm. As an application of this problem, we apply our algorithm for Salt-and-Pepper noise (SPN) and Random-Valued Impulsive Noise...
Stimuli-responsive polyelectrolyte brushes for regulating streaming current magnetic field and energy conversion efficiency in soft nanopores
, Article Physics of Fluids ; Volume 34, Issue 8 , 2022 ; 10706631 (ISSN) ; Saidi, M. H ; Kröger, M ; Tagliazucchi, M ; Sharif University of Technology
American Institute of Physics Inc
2022
Abstract
The electrokinetic energy conversion, electroviscous effect, and induced internal and external magnetic fields in a smart polyelectrolyte grafted "soft"nanopore with pH responsiveness are studied here using an efficient molecular theory approach. The analysis is based on writing the total free energy of the system, including the conformational entropy of the flexible, self-avoiding polymer chains and the translational entropy of the mobile species, the electrostatic interactions, and the free energy due to chemical equilibrium reactions. Then, the free energy is minimized, while satisfying the necessary constraints to find the equilibrium state of the system. The predictions of the model are...
Water desalination by charged multilayer graphene membrane: A molecular dynamics simulation
, Article Journal of Molecular Liquids ; Volume 355 , 2022 ; 01677322 (ISSN) ; Moosavi, A ; Nouri Borujerdi, A ; Sharif University of Technology
Elsevier B.V
2022
Abstract
Graphene, due to its unique excellent properties, is proposed as a developing method with high efficiency compared to classical water desalination methods. In this regard, charging the membrane is considered a promising and effective approach to enhance the performance of the graphene membrane. In this research, by using molecular dynamics simulations, the water desalination by charged multilayer graphene is evaluated and the influence of electric charge amount and geometric parameters, including the pore diameter and the interlayer distance, are investigated. According to the results, the multilayer nanoporous graphene with 16.35 Å pore diameter, in which the electric charge is distributed...
Application of Diazonium Salts for Grafting the Sol-gel Based Sorbents: A New Approach Towards Unbreakable SPME
, M.Sc. Thesis Sharif University of Technology ; Bagheri, Habib (Supervisor)
Abstract
A novel application of diazonium salts for grafting the sol-gel based sorbents was sucessfully introduced. Preparation of unbrekable sorbents has been on highly demand and sough after by many researches for several years. However, there are a few achivements in this regard, but it still remains as a big challenge.Regarding to this issue, diazonium salts were sucessfully applied for functionalizing the different substrates, in which there is no limitation in selection of substrates. Different substrates, metallic and non metallic, such as copper, brass, stailess steel and PTFE were chosen to be functionalized by chemical or electrochemical reduction of 4-Amino phenyl acetic acid. Then,...
Synthesis, Characterization and Voltametric Study of Single Molecule Magnet Hybrid Salts [Mn3O(O2CMe)6(Pyr)3][Keggin-Polyoxometalates]Type
,
M.Sc. Thesis
Sharif University of Technology
;
Mohammadi Boghaei, Davar
(Supervisor)
Abstract
Molecular nanomagnets, also known as Single Molecule Magnets (SMMs) are a class of molecules that at low temperature exhibit magnetic hysteresis of pure molecular origin and not related to a cooperative effect. In the past fifteen years they have attracted great interest for their potentiality to act as magnetic memory units and for the many quantum effects in the dynamics of their magnetization. Organization of SMM on surfaces is the first step in order to address the magnetic state of a single molecule or to connect the molecule to a conducting substrate. The complex nature of SMMs and the peculiar origin of their magnetic bistability have been representing for half a decade an obstacle to...