Search for: surface-active-agents
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    ANFIS modeling of rhamnolipid breakthrough curves on activated carbon

    , Article Chemical Engineering Research and Design ; Volume 126 , 2017 , Pages 67-75 ; 02638762 (ISSN) Baghban, A ; Sasanipour, J ; Haratipour, P ; Alizad, M ; Vafaee Ayouri, M ; Sharif University of Technology
    Institution of Chemical Engineers  2017
    Owning to interesting properties of biosurfactants such as biodegradability and lower toxicity, they have broad application in the food industry, healthy products, and bioremediation as well as for oil recovery. The present study was aimed to develop a GA-ANFIS model for predicting the breakthrough curves for rhamnolipid adsorption over activated carbon. To that end, a set of 296 adsorption data points were utilized to train the proposed FIS structure. Different graphical and statistical methods were also used to evaluate the model's accuracy and reliability. Results were then compared to those of the previously reported Artificial Neural Network (ANN) and Group Method Data Handling (GMDH)... 

    An experimental review on microbubble generation to be used in echo-particle image velocimetry method to determine the pipe flow velocity

    , Article Journal of Fluids Engineering, Transactions of the ASME ; Volume 135, Issue 3 , Feb , 2013 , Paper No: FE-12-1217 ; 00982202 (ISSN) Salari, A ; Shafii, M. B ; Shirani, S ; Sharif University of Technology
    Microbubbles are broadly used as ultrasound contrast agents. In this paper we use a low-cost flow focusing microchannel fabrication method for preparing microbubble contrast agents by using some surface active agents and a viscosity enhancing material to obtain appropriate microbubbles with desired lifetime and stability for any in vitro infusion for velocity measurement. All the five parameters that govern the bubble size extract and some efforts are done to achieve the smallest bubbles by adding suitable surfactant concentrations. By using these microbubbles for the echo-particle image velocimetry method, we experimentally determine the velocity field of steady state and pulsatile pipe... 

    An experimental investigation of surfactant flooding as a good candidate for enhancing oil recovery from fractured reservoirs using one-quarter five spot micromodels: The role of fracture geometrical properties

    , Article Energy Sources, Part A: Recovery, Utilization and Environmental Effects ; Volume 35, Issue 20 , 2013 , Pages 1929-1938 ; 15567036 (ISSN) Kianinejad, A ; Ghazanfari, M. H ; Kharrat, R ; Rashtchian, D ; Sharif University of Technology
    Surfactant flooding is known to lower the interfacial tension and, hence, reduces capillary forces responsible for trapping oil. Despite numerous experimental studies, little is known about the role of fracture geometrical properties on oil recovery efficiency during surfactant floods, especially in five-spot systems. In addition, application of sodium dodecyl sulfate for oil recovery in fractured media is not discussed well. In this study, two types of surfactant solutions have been injected into micromodels, which were initially saturated with crude oil, having different length, orientation, and distribution of fractures under oil-wet conditions. Precise analyses of continuously recorded... 

    An experimental investigation of nanoemulsion enhanced oil recovery: Use of unconsolidated porous systems

    , Article Fuel ; Volume 251 , 2019 , Pages 754-762 ; 00162361 (ISSN) Jalilian, M ; Tabzar, A ; Ghasemi, V ; Mohammadzadeh, O ; Pourafshary, P ; Rezaei, N ; Zendehboudi, S ; Sharif University of Technology
    Elsevier Ltd  2019
    Utilization of nanoparticles in oil and gas industry has attracted considerable attention of engineers and researchers. In this article, the feasibility of nanoemulsion flooding is investigated as a method for Enhanced Oil Recovery (EOR) through coreflooding experiments, using a packed bed and real reservoir fluids. Nine different mixtures of the solvent, surfactant, and nanoparticles in the form of a nanoemulsion phase are generated and used to recover the oil in the context of an EOR process. Various tests are conducted to determine the properties of porous medium and fluids. To study the production performance of this EOR technique, pressure drop across the packed bed are measured, along... 

    An efficient biosurfactant-producing bacterium pseudomonas aeruginosa MR01, isolated from oil excavation areas in south of Iran

    , Article Colloids and Surfaces B: Biointerfaces ; Volume 69, Issue 2 , 2009 , Pages 183-193 ; 09277765 (ISSN) Bagheri Lotfabad, T ; Shourian, M ; Roostaazad, R ; Rouholamini Najafabadi, A ; Adelzadeh, M. R ; Akbari Noghabi, K ; Sharif University of Technology
    A bacterial strain was isolated and cultured from the oil excavation areas in tropical zone in southern Iran. It was affiliated with Pseudomonas. The biochemical characteristics and partial sequenced 16S rRNA gene of isolate, MR01, was identical to those of cultured representatives of the species Pseudomonas aeruginosa. This bacterium was able to produce a type of biosurfactant with excessive foam-forming properties. Compositional analysis revealed that the extracted biosurfactant was composed of high percentages lipid (∼65%, w/w) and carbohydrate (∼30%, w/w) in addition to a minor fraction of protein (∼4%, w/w). The best production of 2.1 g/l was obtained when the cells were grown on... 

    A mechanistic study of emulsion flooding for mobility control in the presence of fatty acids: Effect of chain length

    , Article Fuel ; Volume 276 , 2020 Alizadeh, S ; Suleymani, M ; Sharif University of Technology
    Elsevier Ltd  2020
    Emulsion flooding is a promising method for enhanced oil recovery (EOR). The static and dynamic behavior of the emulsions is greatly influenced by the nature of the applied surfactant. In this work, the effect of fatty acids, as natural surface-active agents, and their chain length on the emulsion behavior was investigated in both bulk and porous media. A panel of the fatty acids with different chain lengths (6 < C < 18) was applied at constant concentration and pH. Upon the static stability tests, emulsion stability at the optimum value of chain length (C14) was increased by two orders of magnitude. Under the optimal condition, the hydrogen bonding between dissociated and undissociated... 

    Adsorption of proteins at the solution/air interface influenced by added nonionic surfactants at very low concentrations for both components. 3. dilational surface rheology

    , Article Journal of Physical Chemistry B ; Volume 119, Issue 9 , January , 2015 , Pages 3768-3775 ; 15206106 (ISSN) Fainerman, V. B ; Aksenenko, E. V ; Lylyk, S. V ; Lotfi, M ; Miller, R ; Sharif University of Technology
    The influence of the addition of the nonionic surfactants C12DMPO, C14DMPO, C10OH, and C10EO5 at concentrations between 10-5 and 10-1 mmol/L to solutions of β-casein (BCS) and β-lactoglobulin (BLG) at a fixed concentration of 10-5 mmol/L on the dilational surface rheology is studied. A maximum in the viscoelasticity modulus |E| occurs at very low surfactant concentrations (10-4 to 10-3 mmol/L) for mixtures of BCS with C12DMPO and C14DMPO and for mixtures of BLG with C10EO5, while for mixture of BCS with C10EO5 the value of |E| only slightly increased. The |E| values... 

    Adsorption of proteins at the solution/air interface influenced by added non-ionic surfactants at very low concentrations for both components. 1. Dodecyl dimethyl phospine oxide

    , Article Colloids and Surfaces A: Physicochemical and Engineering Aspects ; Volume 475, Issue 1 , June , 2015 , Pages 62-68 ; 09277757 (ISSN) Lotfi, M ; Javadi, A ; Lylyk, S. V ; Bastani, D ; Fainerman, V. B ; Miller, R ; Sharif University of Technology
    The adsorption of proteins at liquid interfaces happens at rather low bulk concentrations due to their rather high surface activity. In contrast typical surfactants start to decrease the surface tension at bulk concentration in the range of mmol/l and reach a minimum value at about two or three orders of magnitude higher concentration. The two proteins studied here, β-lactoglobulin and β-casein, adsorb already remarkably at much lower concentrations, i.e. less than 1. μmol/l. When smallest amounts of a non-ionic surfactant are added to low concentrated protein solutions, changes in the surface tension are observed which cannot be explained by the existing theoretical models. An agreement... 

    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
    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... 

    Adaptive neural fuzzy inference (ANFI) modeling technique for production of marine biosurfactant

    , Article Proceedings of the ASME Design Engineering Technical Conference ; Volume 2, Issue PARTS A AND B , 2012 , Pages 47-52 ; 9780791845011 (ISBN) Abbasi, A. A ; Ahmadian, M. T ; Sharif University of Technology
    In this study; a Sugeno type ANFI model which describes the relationship between the bio surfactant concentration as a model output and the critical medium components as its inputs has been constructed. The critical medium components are glucose, urea,SrCl2 and MgSo4 .The experimental data for training and testing capability of the model obtained by a statistical experimental design which have been captured from literatures. Six generalized bell shaped membership function have been selected for each of input variables and based on the training data ANFI model has been trained using the hybrid learning algorithm. The yielded biosurfactant concentration values from the model prediction shows... 

    Acidic heavy oil recovery using a new formulated surfactant accompanying alkali–polymer in high salinity brines

    , Article Journal of Surfactants and Detergents ; Volume 20, Issue 3 , 2017 , Pages 725-733 ; 10973958 (ISSN) Dehghan, A. A ; Jadaly, A ; Ayatollahi, S ; Masihi, M ; Sharif University of Technology
    The strength of a newly formulated surfactant with an alkali and polymer (AS/ASP) to improve an acidic heavy oil recovery was laboratory evaluated by various flooding experiments. The comparative role of the parameters like chemical nature, surface wettability, salinity, temperature and injection scheme were explored at high temperature and pressure on Berea sandstone rocks. According to the results the anionic surfactant is capable of providing proper oil displacement under high salinity conditions around 15 wt%. Continuous monitoring of differential pressure response and effluents’ state clearly represented the formation of an emulsified oil in high saline solutions with both alkali and...