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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,...
A horizontally oriented setup for liquid-liquid-liquid microextraction of estrogens
, Article Analytical Methods ; Volume 5, Issue 22 , 2013 , Pages 6517-6522 ; 17599660 (ISSN) ; Maleki, H ; Es'Haghi, A ; Sharif University of Technology
2013
Abstract
A horizontally oriented liquid-liquid-liquid microextraction (HOLLLME) setup was developed and applied for the isolation of two major estrogens from aquatic media. In contrast to the conventional procedure, in this setup the extracting microdrop was suspended from a horizontally positioned needle in order to provide much higher stability to the extracting phase. The developed HOLLLME approach was applied to isolate two major selected estrogens from aquatic media followed by high performance liquid chromatography-ultraviolet (HPLC-UV) determination. Estrogens were, initially, extracted from water samples into hexane and subsequently, the back extraction stage was performed with 6 μL of sodium...
Simulation analysis of the effects of fractures' geometrical properties on the performance of vapour extraction process
, Article Journal of Canadian Petroleum Technology ; Volume 49, Issue 7 , 2010 , Pages 47-59 ; 00219487 (ISSN) ; Bahonar, M ; Sharif University of Technology
2010
Abstract
Vapour extraction (VAPEX), a newly developed heavy oil recoveiy (HOR) method, has been extensively studied, both theoretically and experimentally, in conventional sandstone models. However, the applicability of this process to naturally fractured reservoirs has not yet been addressed. The objective of this work is to evaluate the effects of fractures' geometrical properties, such as orientation, length of extension, discontinuity in both the upper well region (UWR) and the far well region (FWR) and vertical fracture location on VAPEX performance. Additionally, the effects of horizontal and vertical fracture dispersion in various density, dispersion scheme and networking on the performance of...
Determining proper strategies for health, safety, security and environmental (HSSE) management system
, Article Work ; Volume 45, Issue 3 , 2013 , Pages 399-406 ; 10519815 (ISSN) ; Nasiri, P ; Taghdisi, M ; Abbaspour, M ; Arjmandi, R ; Kalatipor, O ; Sharif University of Technology
2013
Abstract
Today, managing an organization is concerned with many problems. Adopting proper strategies can promote an organization's survival. This study aimed at developing an appropriate HSSE Strategy for regional operation associated companies of Iran National Gas Company (INGS) using SWOT analysis. The analysis of the strengths, weaknesses, opportunities, and threats of HSSE was carried out and according to the results suitable strategies were recommended. In this regard, senior and junior managers, supervisors, and experts active in regional operation associated companies of Iran National Gas Company participated in SWOT analysis from HSSE angle. Then, they selected the most applicable SWOT...
DNE: A method for extracting cascaded diffusion networks from social networks
, Article Proceedings - 2011 IEEE International Conference on Privacy, Security, Risk and Trust and IEEE International Conference on Social Computing, PASSAT/SocialCom 2011, 9 October 2011 through 11 October 2011 ; October , 2011 , Pages 41-48 ; 9780769545783 (ISBN) ; Rabiee, H. R ; Salehi, M ; Sharif University of Technology
2011
Abstract
The spread of information cascades over social networks forms the diffusion networks. The latent structure of diffusion networks makes the problem of extracting diffusion links difficult. As observing the sources of information is not usually possible, the only available prior knowledge is the infection times of individuals. We confront these challenges by proposing a new method called DNE to extract the diffusion networks by using the time-series data. We model the diffusion process on information networks as a Markov random walk process and develop an algorithm to discover the most probable diffusion links. We validate our model on both synthetic and real data and show the low dependency...
Robust image watermarking using independent component analysis
, Article Proceedings - 3rd International Symposium on Information Processing, ISIP 2010, 12 November 2010 through 14 November 2010, Qingdao ; 2010 , Pages 363-367 ; 9780769542614 (ISBN) ; Ghaemmaghami, S ; Sharif University of Technology
2010
Abstract
This paper proposes an image watermarking scheme for copyright protection based on Independent Component Analysis (ICA). In the suggested scheme, we divide the original image into blocks and use the ICA to project the image into a basis with its components as statistically independent as possible. The data embedding is carried out in cumulative form in the ICA basis and also the ICA is used for watermark extraction. The extraction process could be either non-blind, through a straightforward procedure, or blind, via a tricky method we propose. Experimental results show that the new method outperforms some well-known image watermarking methods [1], [2], [3] in spatial or frequency domain and...
The impingement of liquid boiling droplet onto a molten phase change material as a direct-contact solidification method
, Article Thermal Science and Engineering Progress ; Volume 23 , 2021 ; 24519049 (ISSN) ; Mohammadi, O ; Hosseininaveh, H ; Shafii, M. B ; Sharif University of Technology
Elsevier Ltd
2021
Abstract
The boiling of a fluid dripping on the surface of molten phase-change materials provides an efficient means for heat exchange or cooling of the melt. For the first time, in this study, the impact of acetone drops onto molten paraffin as a direct-contact solidification method is experimentally investigated to get a better insight into the interaction between the drop boiling and the heat extraction process from the phase change materials during impact. As the acetone drop impacts the molten paraffin surface, acetone starts to boil, and a portion of molten paraffin is solidified. Four impact Weber numbers (corresponding to heights of 10, 20, 30, and 40 cm) for the acetone drop and six surface...
Efficient scale estimation methods using lightweight deep convolutional neural networks for visual tracking
, Article Neural Computing and Applications ; 2021 ; 09410643 (ISSN) ; Ghanei Yakhdan, H ; Kasaei, S ; Sharif University of Technology
Springer Science and Business Media Deutschland GmbH
2021
Abstract
In recent years, visual tracking methods that are based on discriminative correlation filters (DCFs) have been very promising. However, most of these methods suffer from a lack of robust scale estimation skills. Although a wide range of recent DCF-based methods exploit the features that are extracted from deep convolutional neural networks (CNNs) in their translation model, the scale of the visual target is still estimated by hand-crafted features. Whereas the exploitation of CNNs imposes a high computational burden, this paper exploits pre-trained lightweight CNNs models to propose two efficient scale estimation methods, which not only improve the visual tracking performance but also...
Kinetic modeling and simulation study for a sequential electrochemical extractive crude diesel desulfurization
, Article Separation and Purification Technology ; Volume 278 , 2022 ; 13835866 (ISSN) ; Farhadi, F ; Shahrokhi, M ; Sharif University of Technology
Elsevier B.V
2022
Abstract
To reduce the sulfur content of crude diesel, several sets of experiments have been conducted using electrochemical oxidative desulfurization technique using electrolyte of NaOH at different applied voltages. Due to impacts of operating parameters on desulfurization, kinetic study is pursued and it is found that the kinetic follows a second order reaction rate with a high accuracy. The reaction of desulfurization was modeled using COMSOL and followed by coupled electrochemical oxidation-extraction, while the extraction process was particularly performed using process simulator. The effects of different solvents on extraction performance were studied and dimethyl sulfoxide was selected for...
Assessment of vapor extraction (VAPEX) process performance in naturally fractured reservoirs
, Article Journal of Petroleum Science and Engineering ; Volume 75, Issue 3-4 , January , 2011 , Pages 260-273 ; 09204105 (ISSN) ; Kharrat, R ; Sharif University of Technology
Abstract
The Vapour Assisted Petroleum Extraction (VAPEX) process, a newly developed Enhanced Heavy Oil Recovery process, is a promising EOR method for certain conventional non-fractured heavy oil sandstone reservoirs such as those in Canada, but its applicability on low permeable Naturally Fractured Reservoirs (NFR) such as those in the Middle East and Persian Gulf still remained as a question. Previous studies show that the foremost concern for VAPEX application in the case of NFR is the low non-economical production rates. The aim of the present work is to study the effect of fractures geometrical properties such as orientation (vertical or horizontal), density, spacing, location and networking on...
Investigation the effect of super hydrophobic titania nanoparticles on the mass transfer performance of single drop liquid-liquid extraction process
, Article Separation and Purification Technology ; Volume 176 , 2017 , Pages 107-119 ; 13835866 (ISSN) ; Bastani, D ; Najafi, F ; Sharif University of Technology
Abstract
Hydrophobic titania nanoparticles were synthesized by a novel in situ sol-gel method and applied in a single drop liquid-liquid extraction column to enhance the overall dispersed-phase mass transfer coefficient (Kod). The chemical system of toluene, acetic acid and water was used, and the direction of solute (acetic acid) mass transfer was from dispersed phase, including: toluene and acetic acid to the continuous phase of water. For such system, much of the mass transfer resistance exists in the dispersed phase, which is nonpolar organic liquid. Hence, modified titania nanoparticles (MTNP's), prepared by sol-gel route, in five different concentrations of 0.001–0.005 wt.% were added in the...
Mass transfer evaluation in a multi-impeller extractor for reactive Mo (VI) extraction from aqueous Sulphate solution by utilizing coupling of acid and solvating Extractants
, Article Heat and Mass Transfer/Waerme- und Stoffuebertragung ; Volume 56, Issue 6 , 2020 , Pages 1995-2006 ; Torab Mostaedi, M ; Outokesh, M ; Asadollahzadeh, M ; Sharif University of Technology
Springer
2020
Abstract
In this study, mass transfer experimental data from the present column with 70 cm active column length and 11.3 cm internal diameter were interpreted for molybdenum extraction with a mixture of D2EHPA and TBP in terms of the axial diffusion model. The influence of extractants concentration and the initial aqueous pH have studied in the bench-scale experiments. The experimental finding demonstrated that the synergistic solvent extraction increases the constancy of the extracted complexes for transfer into the organic phase. The effect of operating parameters, including agitation speed and inlet phase velocities on the overall mass transfer coefficients under the chemical reaction system, is...
Combined model of mass-transfer coefficients for clean and contaminated liquid-liquid systems
, Article Industrial and Engineering Chemistry Research ; Volume 50, Issue 8 , 2011 , Pages 4608-4617 ; 08885885 (ISSN) ; Dehkordi, A. M ; Darbandi, M ; Shahalami, M ; Saien, J ; Sharif University of Technology
Abstract
Mass-transfer rates to and from drops in liquid-liquid extraction processes are often reduced by the presence of contaminants. To design an industrial extractor, it is essential to consider this contamination effect in a quantitative manner. To achieve this goal, an experimental investigation was conducted on the mass transfer into single drops for n-butanol-succinic acid-water, as the recommended test system by the European Federation of Chemical Engineering (EFCE). The effects of anionic (sodium dodecyl sulfate, SDS), cationic (dodecyl trimethyl ammonium chloride, DTMAC), and nonionic (octylphenol decaethylene glycol ether, Triton X-100) surfactants on the hydrodynamic and mass-transfer...
Retarding effect of contaminants on the performance of a two-impinging-jets liquid-liquid extraction contactor
, Article Chemical Engineering and Technology ; Volume 33, Issue 6 , June , 2010 , Pages 1003-1010 ; 09307516 (ISSN) ; Doghahe, S. A. O ; Dehkordi, A. M ; Sharif University of Technology
2010
Abstract
In industrial liquid-liquid extraction processes, the feed is not clean liquid but there are various kinds of contaminants in the feed entering the extractors. In this regard, a two-impinging-jets contacting device (TIJCD) was tested through the standard test system recommended by the European Federation of Chemical Engineering (EFCE), namely toluene-acetone-water, in the presence and absence of various types of surface-active agents (SAAs). The influences of anionic, cationic, and nonionic SAAs such as sodium dodecyl sulfate (SDS), dodecyl trimethyl ammonium chloride (DTMAC), and octylphenol decaethylene glycol ether (Triton X-100), respectively, on the extraction efficiency and overall...
Liquid-liquid-liquid microextraction followed by HPLC with UV detection for quantitation of ephedrine in urine
, Article Journal of Separation Science ; Volume 31, Issue 18 , 2008 , Pages 3212-3217 ; 16159306 (ISSN) ; Khalilian, F ; Ahangar, L. E ; Sharif University of Technology
2008
Abstract
Liquid-liquid-liquid microextraction (LLLME) in combination with HPLC and UV detection has been used as a sensitive method for the determination of ephedrine in urine samples. Extraction process was performed in a homemade total glass vial without using a Teflon ring, usually employed. Ephedrine was first extracted from 3.5 mL of urine sample (pH 12) into a microfilm of toluene/benzene (50:50). The analyte was subsequently back extracted into an acidic microdrop solution (pH 2) suspended in the organic phase. The extract was then injected into the HPLC system directly. An enrichment factor of 137 along with a good sample clean-up was obtained under the optimized conditions. The calibration...
New approach in the prediction of RDC liquid-liquid extraction column parameters
, Article Chemical Engineering and Technology ; Volume 31, Issue 7 , 2008 , Pages 971-977 ; 09307516 (ISSN) ; Shahalami, S. M ; Sharif University of Technology
2008
Abstract
The liquid-liquid extraction process is well-known for its complexity and often entails intensive modeling and computational efforts to simulate its dynamic behavior. This paper presents a new application of the Genetic Algorithm (GA) to predict the modeling parameters of a chemical pilot plant involving a rotating disc liquid-liquid extraction contactor (RDC). In this process, the droplet behavior of the dispersed phase has a strong influence on the mass transfer performance of the column. The mass transfer mechanism inside the drops of the dispersed phase was modeled by the Handlos-Baron circulating drop model with consideration of the effect of forward mixing. Using the Genetic Algorithm...
Aniline-silica nanocomposite as a novel solid phase microextraction fiber coating
, Article Journal of Chromatography A ; Volume 1238 , May , 2012 , Pages 22-29 ; 00219673 (ISSN) ; Roostaie, A ; Sharif University of Technology
2012
Abstract
A new unbreakable solid phase microextraction (SPME) fiber coating based on aniline-silica nanocomposite was electrodeposited on a stainless steel wire. The electropolymerization process was carried out at a constant deposition potential, applied to the corresponding aqueous electrolyte containing aniline and silica nanoparticles. The scanning electron microscopy (SEM) images showed the non-smooth and the porous surface structure of the prepared nanocomposite. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some environmentally important polycyclic aromatic hydrocarbons (PAHs), as model compounds, from aqueous samples....
Novel polyamide-based nanofibers prepared by electrospinning technique for headspace solid-phase microextraction of phenol and chlorophenols from environmental samples
, Article Analytica Chimica Acta ; Volume 716 , 2012 , Pages 34-39 ; 00032670 (ISSN) ; Aghakhani, A ; Baghernejad, M ; Akbarinejad, A ; Sharif University of Technology
2012
Abstract
A novel solid phase microextraction (SPME) fiber was fabricated by electrospinning method in which a polymeric solution was converted to nanofibers using high voltages. A thin stainless steel wire was coated by the network of polymeric nanofibers. The polymeric nanofiber coating on the wire was mechanically stable due to the fine and continuous nanofibers formation around the wire with a three dimensional structure. Polyamide (nylon 6), due to its suitable characteristics was used to prepare the unbreakable SPME nanofiber. The scanning electron microscopy (SEM) images of this new coating showed a diameter range of 100-200nm for polyamide nanofibers with a homogeneous and porous surface...
A novel needle trap sorbent based on carbon nanotube-sol-gel for microextraction of polycyclic aromatic hydrocarbons from aquatic media
, Article Analytica Chimica Acta ; Volume 683, Issue 2 , January , 2011 , Pages 212-220 ; 00032670 (ISSN) ; Ayazi, Z ; Aghakhani, A ; Sharif University of Technology
2011
Abstract
A new type of composite material based on carbon nanotubes (CNTs) and sol-gel chemistry was prepared and used as sorbent for needle trap device (NTD). The synthesized composite was prepared in a way to disperse CNTs molecules in a sol-gel polymeric network. CNT/silica composites with different CNT doping levels were successfully prepared, and the extraction capability of each composite was evaluated. Effects of surfactant and the oxidation duration of CNTs on the extraction efficiency of synthesized composites were also investigated. The applicability of the synthesized sorbent was examined by developing a method based on needle trap extraction (NTE) and gas chromatography mass spectrometry...