Full article
Petroleum and Reservoir Engineering
P. Shahsavarzadeh-Jangi; S. A. Shojaosadati; S. Hashemi-Najafabadi; S. M. Mousavi
Volume 12, Issue 1 , Winter 2015, Pages 3-12
Abstract
orption ofcontaminants in soil and sequestration in soil particles is a process, the mechanisms of which are not well understood as yet. The aim of this study was to investigate sequestration and bioavailability of crude oil as a contaminant in three different soils. For this purpose, three different ...
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orption ofcontaminants in soil and sequestration in soil particles is a process, the mechanisms of which are not well understood as yet. The aim of this study was to investigate sequestration and bioavailability of crude oil as a contaminant in three different soils. For this purpose, three different soil samples with different textures (loamy sand, loam, and clay loam) but with the same organic carbon were collected. After sterilization, the soils were spiked with crude oil. Each soil sample was contaminated as aged and fresh, and inoculated with a consortium ofthree bacterial isolates. Respiration was analyzed on days 0, 30, 60, and 90 after inoculation. Bacterial population was also assessed at the beginning and at the end ofthe bioremediation and residual contaminant at the end ofthe bioremediation process. The results showed that in soils with the same organic carbon, texture is an important parameter in aging and sequestration of the contaminant. In addition, it was observed that the best degradation was accomplished in the loam soil, due to more bioavailability as compared to the clay loam soil and less inhibitory effect of the contaminant on microbial growth, resulting from lower bioavailability, as compared to the loamy sand soil.
Full article
Separation Technology,
S. Shirazian; S. N. Ashrafizadeh
Volume 12, Issue 1 , Winter 2015, Pages 13-21
Abstract
ine"> Chabazite zeolite membranes were synthesized for their potential application in dehydration of natural gas. The membranes were prepared using secondary growth method on porous ·-alumina substrates. Hydrothermal treatment was applied for the synthesis of chabazite seeds. The membranes ...
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ine"> Chabazite zeolite membranes were synthesized for their potential application in dehydration of natural gas. The membranes were prepared using secondary growth method on porous ·-alumina substrates. Hydrothermal treatment was applied for the synthesis of chabazite seeds. The membranes were synthesized at four temperatures of 100, 120, 140, and 160°C; and duration of 20 h. Separation performance of assynthesized membranes was evaluated through permeation ofwater vapor and methane as single gas. Moreover, the structure and morphology ofas-synthesized chabazite zeolite membranes as well as seeds were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and dynamic light scattering (DLS). The results revealed that the optimum temperature for the synthesis ofchabazite membranes is 140°C while at lower and higher temperatures, lower separation performances were observed. At the optimum synthesis temperature, an ideal selectivity of 23 was obtained for water vapor/methane, while a thin and integrated chabazite zeolite layer of about 5 m in thickness was synthesized over the surface ofalumina substrate.
Full article
Biomedical and Biotechnology,
M. Azizi; H. Ghourchian; F. Yazdian; F. Dashtestani
Volume 12, Issue 1 , Winter 2015, Pages 22-29
Abstract
"> There has been considerable interest in developing albumin nanoparticles as drug delivery devices. Albumin is an important endogenous antioxidant due to its potential of acting as reactive oxygen species scavenger. On the other hand, toxicity of silver nanoparticles had been demonstrated on cancer ...
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"> There has been considerable interest in developing albumin nanoparticles as drug delivery devices. Albumin is an important endogenous antioxidant due to its potential of acting as reactive oxygen species scavenger. On the other hand, toxicity of silver nanoparticles had been demonstrated on cancer cell lines. In the present study, Ag NPs coated with BSA NPs were synthesized by silver nanoparticles which were coated with bovine serum albumin (BSA) via desolvation technique. The Ag NPs coated with BSA NPs formation was confirmed by UV-Vis spectroscopy and #_>ADF;;==@ Dynamic Light Scattering (DLS). Human breast cancer cells (MCF7 cells) were then cultured in the presence of the nanoparticles to evaluate the cytotoxicity of Ag NPs coated with BSA NPs by the MTT colorimetric technique. The antioxidant activities ofAg NPs coated with BSA NPs were evaluated in terms of their inhibition of autoxidation rate of pyrogallol as superoxide. The effect ofAg NPs coated with BSA NPs on MCF7 exhibit a dose-dependent toxicity for the cell tested and the viability of MCF-7 decreased to 50% (LD50) at the concentration of5 Ïg/mL. The IC50 value ofantioxidant activities ofAg NPs coated with BSA NPs were 8 µg/mL which demonstrated that Ag NPs coated with BSA NPs were good superoxide scavengers. In conclusion, our data show that Ag NPs coated with BSA NPs had antioxidant and anticancer activities in MCF-7 cells.
Full article
Transport Phenomena,
S. Abbasi; S. M. Zebarjad; S. H. NoieBaghban; A. Youssef; M. S. Ekrami-Kakhki
Volume 12, Issue 1 , Winter 2015, Pages 30-40
Abstract
In this paper, we report for the first time, thermal conductivity behavior of nanofluids containing decorated MWCNTs with different amount of TiO2 nanoparticles. TEM image confirmed that the outer surface of MWCNTs successfully decorated with TiO2 nanoparticles. The results of thermal conductivity behavior ...
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In this paper, we report for the first time, thermal conductivity behavior of nanofluids containing decorated MWCNTs with different amount of TiO2 nanoparticles. TEM image confirmed that the outer surface of MWCNTs successfully decorated with TiO2 nanoparticles. The results of thermal conductivity behavior of nanofluids revealed that the thermal conductivity and enhancement ratio of thermal conductivity of MWCNTsTiO2 at different amount of TiO2 nanoparticles are higher than those of TiO2 and MWCNTs nanofluids. Temperature and weight fraction dependence study also shows that the thermal conductivity of all nanofluids increases with temperature and weight fraction. However, the influence of temperature is more significant than that of weight fraction. We also found that decreasing amount ofTiO2 nanoparticles which introduce the outer surface of MWCNTs leads to the augmentation of thermal conductivity of nanofluids containing MWCNTs-TiO2.
Full article
Transport Phenomena,
A. R. Bahramian
Volume 12, Issue 1 , Winter 2015, Pages 42-59
Abstract
> The hydrodynamic characteristics of dense conical fluidized bed were investigated experimentally and numerically. Experimental studies have been carried out in a bed containing TiO2 particles belonging to A/C boundary of Geldart's classification with a wide particle size distribution. Pressure measurements ...
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> The hydrodynamic characteristics of dense conical fluidized bed were investigated experimentally and numerically. Experimental studies have been carried out in a bed containing TiO2 particles belonging to A/C boundary of Geldart's classification with a wide particle size distribution. Pressure measurements and an optical fiber technique allowed determining the effect ofhigh bed particles loading on the minimum fluidization velocity, local solid volume fraction and solid velocity. Two-fluid model approach with three different drag models and boundary conditions (BCs) consisting ofno-slip, partialslip and free-slip BC is presented for the numerical predictions. In this paper, we show the Gidaspow drag function with k-Â turbulent model by applying the partial-slip BC can improve the numerical results at high particle loading.
Research note
Modeling and Simulation
R. Rahimi; M. H. Soodmand; M. Zivdar; A. Alborzi; M. Rahmanian
Volume 12, Issue 1 , Winter 2015, Pages 60-67
Abstract
The distillation process remains as the most common method ofseparation in chemical process industries. The energy used from this process accounts for an estimated 3% of the world energy consumption. The Dividing-Wall Column (DWC) for separation of multi-component mixtures has recently become a major ...
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The distillation process remains as the most common method ofseparation in chemical process industries. The energy used from this process accounts for an estimated 3% of the world energy consumption. The Dividing-Wall Column (DWC) for separation of multi-component mixtures has recently become a major concern ofindustries. The design ofDWC is based on Thermally Coupled Distillation System (TCDS) eliminating some of the operational equipment. This paper presents the results of simulation of a DWC by using 3-simple sequence column model based on shortcut method by a commercial chemical Engineering software for purification of1,3 butadiene unit. From the results, it is shown, by using a DWC instead of two conventional sequential column, the heat duties ofboth the condenser and the reboiler are reduced about 28.5% and also desirable purity ofthe key-components for the case ofstudy have been achieved.
Research note
Separation Technology,
M. Shokouhi; M. Hosseini-Jenab; A. Mehdizadeh; A. Naser Ahmadi; A. H. Jalili
Volume 12, Issue 1 , Winter 2015, Pages 68-77
Abstract
In this paper, the experimental investigation ofsolubility and initial absorption rate of CO2 gas in methanol and 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4] solution of amine-functionalized imidazolium based ionic liquids, namely 1-(3- aminopropyl)-3-methylimidazolium, [apmim], with tetrafluoroborate, ...
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In this paper, the experimental investigation ofsolubility and initial absorption rate of CO2 gas in methanol and 1-ethyl-3-methylimidazolium ethylsulfate, [emim][EtSO4] solution of amine-functionalized imidazolium based ionic liquids, namely 1-(3- aminopropyl)-3-methylimidazolium, [apmim], with tetrafluoroborate, [BF4], hexafluorophosphate, [PF6] and trifluoromethanesulfonate [OTf] anions are presented. All ionic liquids in this work are synthesized according to literature procedure and all experimental trials were carried out at T=303.15 K and pressure from atmospheric to 40 bar.