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Preparation of Cobalt and Manganese Salts of Para-amino Benzoic Acid Supported on Graphene Oxide as an Oxidative Nanocatalysts
, M.Sc. Thesis Sharif University of Technology ; Mahmoodi Hashemi, Mohammad (Supervisor)
Abstract
In this thesis, a heterogeneous nanocatalyst based on graphene oxide was synthesized. To improve the graphene oxide, it was reacted with paraaminobenzoic acid and then metal salts (cobalt and manganese) were coated on it. The structure of the catalyst was confirmed by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), quantitative X-ray diffraction (EDS) and infrared (FT-IR) spectroscopy. Finally, the catalytic properties of the catalysts were evaluated in the oxidation reaction of different alcohols in the presence of oxygen. In the presence of benzyl alcohols with lethal electron groups, the oxidation conditions are stricter and the reaction efficiency is lower....
Saltwater Up-coning into Pumping Wells in Coastal Aquifers in Fractured
Soil
,
M.Sc. Thesis
Sharif University of Technology
;
Ataie Ashtiani, Behzad
(Supervisor)
Abstract
The goal of this research is to investigate the phenomenon of saltwater up-coning into pumping wells in fractured porous media. For this aim, two series of regular orthogonal fracture networks and different vertical and horizontal fracture apertures are simulated using an axisymmetric (2D vertical cross-section) model with a sharp interface approach. The effect of changing the pumping rate and the hydraulic conductivity has been examined to recognize other effective characteristics of the aquifer and pumping well on the saltwater up-coning. These simulations have been performed in COMSOL Multiphysics. The results indicate that the saltwater extent under the pumping well can be affected...
Optimization of platinum extraction by Trioctylphosphine oxide in the presence of alkaline-metal salts
, Article Procedia Engineering, 25 August 2012 through 29 August 2012 ; Volume 42 , August , 2012 , Pages 1302-1312 ; 18777058 (ISSN) ; Kazemeini, M ; Sharif University of Technology
2012
Abstract
Effect of alkaline metal salts on the solvent extraction of platinum from leached spent dehydrogenation catalysts (Pt/Al2O3) in aqua-regia by the Trioctylphosphine oxide (TOPO) has been investigated. Best salting out effect was achieved using KCl as the additive salt in which process upto 90% of Platinum extraction achieved. Response Surface methodology utilized in order to design the experiments, model the extraction process for platinum and aluminum as well as; optimize the whole process. It was shown that solvent extraction of platinum by TOPO was kinetically fast and the needed equilibrium time for it was less than 30 seconds. In the present study, proposed models for platinum and...
Platinum extraction from spent catalysts by TOPO utilizing RSM technique
, Article Advanced Materials Research ; Volume 548 , 2012 , Pages 186-192 ; 10226680 (ISSN) ; 9783037854532 (ISBN) ; Kazemeini, M ; Fattahi, M ; Sharif University of Technology
2012
Abstract
In this research, data on liquid-liquid extraction of platinum from commercial spent catalysts by trioctylphosphine oxide (TOPO) in toluene were experimentally obtained. Alkaline metal salts were used to optimize the separation process. Best Salting-out effect was obtained by KCl which extracted up to 90% of platinum utilizing TOPO. Furthermore, extraction percentages of Pt and Al depending upon different factors were investigated. It was observed that the extraction process was kinetically fast and achieving the equilibrium time took less than 30 seconds. Optimized points obtained utilizing response surface methodology (RSM) by the "Design Expert" software in order to minimize the...
Effect of asphaltene and resin on interfacial tension of acidic crude oil/ sulfate aqueous solution: Experimental study
, Article Fluid Phase Equilibria ; Volume 414 , 2016 , Pages 149-155 ; 03783812 (ISSN) ; Ayatollahi, S ; Sharif University of Technology
Elsevier
2016
Abstract
Although the capability of using sulfate anion as a wettability modiffier is well established, no systematic investigation on the effect of sulfate ions and natural surfactants in the crude oil including asphaltene and resin on the interfacial tension (IFT) of acidic crude oil (ACO)/sulfate were performed. In this regards, the fluid/fluid interactions are tested through the IFT measurements for ACO, asphaltene and resin extracted from ACO in the presence of sulfate salts including Na2SO4, MgSO4 and CaSO4 while the concentration of each salt ranges between 0 and 45000 ppm. The obtained results demonstrate that the capability of asphaltene molecules is higher for IFT reduction compared with...
Investigation of Water Salinity Effect on Asphaltene Precipitation Using PC-SAFT EOS
, M.Sc. Thesis Sharif University of Technology ; Jamshidi, Saeed (Supervisor)
Abstract
In this study, for investigation of water salinity effect on asphaltene modeling, PC-SAFT equation of state has been used. All steps of modeling have been done by C sharp programming language software. Nghiem model has been used for modeling of asphalting pure solid. In this model, the heaviest component is split into two precipitating and nonprecipitation parts that their physical properties are the same in each part. Furthermore, to determine the exact mechanism of asphaltene precipitation, an oil model (Asphaltene+heptan+tuloene) in the presence of different water brine such as synthetic brine (with MgCl2, CaCl2, and Na2SO4 salts), seawater) ten and two times diluted), and formation water...
The impacts of aqueous ions on interfacial tension and wettability of an asphaltenic-acidic crude oil reservoir during smart water injection
, Article Journal of Chemical and Engineering Data ; Vol. 59, issue. 11 , 2014 , pp. 3624-3634 ; ISSN: 00219568 ; Ayatollahi, S ; Riazi, M ; Sharif University of Technology
Abstract
The use of adjusted/optimized saline water categorized into two different classes namely smart water (SW) and low salinity (LoSal) water injection has been proposed for more oil recovery from specific types of oil reservoirs. There are possible mechanisms concerning SW flooding that have been proposed in the literature, some of them are still subject to more examination. In this study, an experimental investigation is performed to determine the influence of type and amount of salt to the surface properties including interfacial tension (IFT) and contact angle (CA) of aqueous solution + acidic and asphaltenic crude oil + carbonate rock systems. For this purpose, the concentration of different...
New algorithms for recovering highly corrupted images with impulse noise
, Article Scientia Iranica ; Volume 19, Issue 6 , December , 2012 , Pages 1738-1745 ; 10263098 (ISSN) ; Feghahati, A. H ; Jamzad, M ; Sharif University of Technology
2012
Abstract
In this work, we present a new method of noise removal which is applied on images corrupted by impulse noise. This new algorithm has a good trade-off between quantitative and qualitative properties of the recovered image and the computation time. In this new method, the corrupted pixels are replaced by using a median filter or, they are estimated by their neighbors' values. Our proposed method shows better results especially in very high density noisy images than Standard Median Filter (SMF), Adaptive Median Filter (AMF) and some other well-known filters for removing impulse noise. Experimental results show the superiority of the proposed algorithm in measures of PSNR and SSIM, specifically...
Colourimetric-based method for the diagnosis of spinal muscular atrophy using gold nanoprobes
, Article IET Nanobiotechnology ; Volume 9, Issue 1 , Feb , 2015 , Pages 5-10 ; 17518741 (ISSN) ; Hormozi Nezhad, M. R ; Abadi, A. R ; Sanati, M. H ; Kazemi, B ; Sharif University of Technology
Institution of Engineering and Technology
2015
Abstract
Although numerous molecular methods for spinal muscular atrophy (SMA) detection have been exploited, most of hem are laborious, time consuming and costly. Recently, gold nanoparticles (AuNPs) have attracted attention in the field of colourimetric bioanalysis, because AuNP aggregation can be tracked with the naked eye as well as ultraviolet-visible (UV-vis) peak analysis. Here, based on a non-cross linking platform, a colourimetric-based method was used to evaluate the capability of thiolated oligo-AuNPs (Au nanoprobes) to distinguish between normal individuals, carriers and those with SMA. In this platform, removal of the repulsive force of the Au nanoprobes using high salt concentration...
Partitioning of l-lysine monohydrochloride in aqueous two-phase systems of poly(ethylene glycol) and dipotassium hydrogen phosphate or trisodium citrate 5-hydrate
, Article Journal of Chemical and Engineering Data ; Volume 55, Issue 9 , 2010 , Pages 3005-3009 ; 00219568 (ISSN) ; Pazuki, G ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
2010
Abstract
The partition constants of l-lysine HCl were measured in polymer-salt aqueous two-phase systems. These systems contain poly(ethylene glycol) with a nominal molecular weight of 4000 or 10000 and two different salts (dipotassium hydrogen phosphate or trisodium citrate 5-hydrate). The experimental data were obtained at temperatures of (293.15, 298.15, and 303.15) K. The effects of temperature, pH, polymer and salt concentrations, polymer molecular weight, and salt type on the partitioning of l-lysine HCl were also studied. The results showed that salt concentration has a significant effect on the partition constant while temperature has less effect. The Diamond and Hsu model was used to...
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) ; Sahimi, M ; Rahimi Tabar, M. R ; Sharif University of Technology
American Physical Society
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....
Part load behavior of molten salt cavity receiver solar tower plants under storage mode operational mode
, Article ASME 2016 10th International Conference on Energy Sustainability, ES 2016, collocated with the ASME 2016 Power Conference and the ASME 2016 14th International Conference on Fuel Cell Science, Engineering and Technology, 26 June 2016 through 30 June 2016 ; Volume 1 , 2016 ; 9780791850220 (ISBN) ; Shafiei Ghazani, A ; Taylor, R. A ; Saberi, P ; Sharif University of Technology
American Society of Mechanical Engineers
2016
Abstract
The performance of the tower based concentrated solar thermal (CST-tower) plant is very sensitive to the operation strategy of the plant and the incident heat flux on the receiver. To date, most studies have been examined only the design mode characteristics of the cavity receivers, but this paper significantly expands the literature by considering non-design operating conditions of this important sub-component of the CST-tower plants. A feasible non-design operating conditions of the cavity receivers that was considered in this study is the storage mode of operation. Two practical dynamic control strategies were examined then to find the most efficient approach: fixed solar field mass...
Antipolyelectrolyte superabsorbing nanocomposites: synthesis and properties
, Article Journal of Applied Polymer Science ; Volume 114, Issue 6 , 2009 , Pages 3542-3547 ; 00218995 (ISSN) ; Kheirabadi, M ; Zohuriaan Mehr, M. J ; Kabiri, K ; Sharif University of Technology
Abstract
Novel polyampholytic superabsorbing nanocomposites based on the zwitterionic sulfobetaine monomer [3-(methacrylamido)propyl)]dimethyl(3- sulfopropyl)ammonium hydroxide were synthesized through in situ polymerization in aqueous solution with different contents of an organo-modified clay (OMMT, Cloisite 30B). Structural and thermomechanical properties of hydrogels were characterized by FT-IR, XRD, and DMTA, respectively. Swollen gel strength of hydrogels was determined by a rheological method. Storage modulus of the hydrogels was considerably improved in comparison with its the clay-free counterpart. The nanocomposite hydrogel containing 15% OMMT possessed the highest gel strength. The glass...
Formation of Zn-Ca-Ni tri cation's phosphate coating on steel and study that properties
, Article TMS 2009 - 138th Annual Meeting and Exhibition, San Francisco, CA, 15 February 2009 through 19 February 2009 ; Volume 1 , 2009 , Pages 615-623 ; 9780873397384 (ISBN) ; Afshar, A ; Sharif University of Technology
2009
Abstract
A new Zinc phosphating bath, which produces coatings at relatively lower temperatures within a reasonable time by using of chemical accelerators has been devised. Improvement of the bath performance by the addition of divalent cations like calcium, nickel has been studied. Bath formulation and operating conditions have been optimized by coating weight determinations. Stable samples of phosphating formulations with and without calcium and nickel salts were prepared and the structure and morphology of the phosphate coatings were determined by using X-ray diffraction (XRD) techniques, scanning electron microscopy. ASTMB117 salt spray test and electrochemical impedance spectroscopy (EIS) were...
Electrodeposition of Al, Mn, and Al-Mn alloy on aluminum electrodes from molten salt (AlCl3-NaCl-KCl)
, Article Journal of Applied Electrochemistry ; Volume 39, Issue 8 , 2009 , Pages 1297-1303 ; 0021891X (ISSN) ; Maleki, A ; Danaee, I ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
2009
Abstract
Electrochemical deposition of aluminum and manganese from basic and acidic molten AlCl3-NaCl-KCl mixture on an aluminum electrode at 180 °C was studied by the methods of voltammetry, and potential and current transient. The deposition of aluminum was found to proceed via a nucleation/growth mechanism in basic melt, while the deposition of manganese was found to be diffusion controlled in basic melt. The diffusion coefficient of Mn2+ ions in basic melt, as derived by voltammetry was in agreement with the deductions of transient methods. Analysis of the chronoamperograms indicates that the deposition of manganese on Al was controlled by 3D diffusion controlled nucleation and growth. The...
Electrocrystallization of Pb and Pb assisted Al on aluminum electrode from molten salt (AlCl3-NaCl-KCl)
, Article Journal of Alloys and Compounds ; Volume 478, Issue 1-2 , 2009 , Pages 83-88 ; 09258388 (ISSN) ; Danaee, I ; Maleki, A ; Gobal, F ; Mahjani, M. G ; Sharif University of Technology
2009
Abstract
Electrochemical deposition of aluminum and lead from basic molten AlCl3-NaCl-KCl mixture on an aluminum electrode at 180 °C was studied by the methods of voltammetry, potential and current transient and constant current deposition. The deposition of aluminum was found to proceed via a nucleation/growth mechanism, while the deposition of lead was found to be diffusion controlled. The diffusion coefficient calculated for Pb2+ ions in basic melt by voltammetry was in agreement with the deductions of transient method. The analysis of the chronoamperograms indicates that the deposition process of lead on Al substrates was controlled by 3D diffusion control, nucleation and growth. The processes...
Applications of highly salt and highly temperature resistance terpolymer of acrylamide/styrene/maleic anhydride monomers as a rheological modifier: Rheological and corrosion protection properties studies
, Article Journal of Molecular Liquids ; Volume 294 , 2019 ; 01677322 (ISSN) ; Ramezani Saadat Abadi, A ; Haddadi, A ; Sharif University of Technology
Elsevier B.V
2019
Abstract
Due to the weak performance of commercially affordable natural and synthetic polymeric thickeners in high temperatures and salinity, they fail to use in many applications especially in saline conditions with high temperatures. In this work, a new salt and temperature resistance acrylamide/styrene/maleic anhydride terpolymer (PASM-t) with self-associative properties was synthesized via a one-step inverse emulsion polymerization and its applicability as a rheological modifier and thickener was investigated. The characteristics of synthesized PASM-t (s-PASM-t) and its aqueous solutions were investigated using FT-IR, FE-SEM, GPC and rheometric mechanical spectrometry (RMS) analyses. The...
Enhancing water desalination in graphene-based membranes via an oscillating electric field
, Article Desalination ; Volume 495 , December , 2020 ; Moosavi, A ; Nouri Borujerdi, A ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Water desalination methods on the basis of newly developed graphene-based membrane have been introduced as a more efficient alternative for the conventional water purification technologies such as classical thermal desalination and reverse osmosis (RO). However, the increase of water permeation rate and ion rejection are still the main subjects in this field. In this study, a new method based on using oscillating electric field is proposed to improve the performance of nanoporous graphene. The effects of the amplitude and oscillation frequency of the electric field and the pore size of the membrane on the water permeation and salt rejection are studied by conducting molecular dynamics...
Influence of lakebed sediment deposit on the interaction of hypersaline lake and groundwater: A simplified case of lake Urmia, Iran
, Article Journal of Hydrology ; Volume 588 , 2020 ; Ataie Ashtiani, B ; Safaie, A ; Simmons, C. T ; Sharif University of Technology
Elsevier B.V
2020
Abstract
Lake Urmia, which was once the second-largest saline lake in the world, has been shrinking dramatically. Moreover, Lake Urmia has become supersaturated with total salinity averaging more than 350 g/l. Salt precipitation and dissolved materials brought by inflowing rivers have formed a layer of sediment with low hydraulic conductivity on the lakebed. Considering the flat bathymetry of Lake Urmia, we conducted a series of numerical simulation scenarios to study the groundwater flow pattern in the vicinity of the hypersaline Lake Urmia using COMSOL Multiphysics®. In the first step, we performed the simulations in steady-state conditions. Secondly, we simulated the lake level fall in 10 years at...
Investigation of rock salt layer creep and its effects on casing collapse
, Article International Journal of Mining Science and Technology ; Volume 30, Issue 3 , 2020 , Pages 357-365 ; Pak, A ; Shad, S ; Mehrgini, B ; Razifar, M ; Sharif University of Technology
China University of Mining and Technology
2020
Abstract
Casing collapse is one of the costly incidents in the oil industry. In the oil fields of southwest Iran, most casing collapses have occurred in Gachsaran formation, and the halite rock salt layer in this formation may be the main cause for these incidents because of its peculiar creep behavior. In this research, triaxial creep experiments have been conducted on Gachsaran salt samples under various temperatures and differential stresses. The main purpose was to determine the creep characteristics of Gachsaran rock salt, and to examine the role of creep in several casing collapses that occurred in this formation. Results indicated that the halite rock salt of Gachsaran formation basically...