Thermodynamics,
Volume 5, Issue 4 , October 2008, , Pages 39-48
Abstract
The UNIQUAC activity coefficient model is extended to predict solid-liquid equilibrium of isotactic crystalline poly (1-butene), iPBu-1, in different organic solvents. The UNIQUAC activity coefficient model used in this work is based on the concept of group contribution and consists of combinatorial, ...
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The UNIQUAC activity coefficient model is extended to predict solid-liquid equilibrium of isotactic crystalline poly (1-butene), iPBu-1, in different organic solvents. The UNIQUAC activity coefficient model used in this work is based on the concept of group contribution and consists of combinatorial, residual and free volume terms. To account for branching of atom groups in the monomer structure of the polymer, a correction factor has been applied to the surface parameter of combinatorial and residual terms. Use of this correction factor has significantly improved the accuracy of the model and shows that the proposed activity coefficient model is a proper model for solid-liquid equilibrium calculation in polymer solutions.
Separation Technology,
Volume 1, Issue 2 , July 2004, , Pages 39-44
Abstract
Recently, use of naturally-occurring low-cost and harmless material for removal of trace contaminants from colored wastewater has attracted extensive attention. In this study, silkworm pupa has been used as a basic dye adsorbent. Adsorption capacity and isotherms have been assessed. Results show that ...
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Recently, use of naturally-occurring low-cost and harmless material for removal of trace contaminants from colored wastewater has attracted extensive attention. In this study, silkworm pupa has been used as a basic dye adsorbent. Adsorption capacity and isotherms have been assessed. Results show that adsorption isotherms can be expressed well by Langmuir equation. The effects of parameters such as pH, temperature, agitation time and speed on the adsorption efficiency were investigated. It was found that among those factors the pH is the most pronounced one. Also the adsorption capacity of pupa towards the various cationic dyes is changed as follows: basic blue >basic yellow >basic red.
Separation Technology,
Volume 11, Issue 4 , October 2014, , Pages 40-49
Petroleum and Reservoir Engineering
Volume 9, Issue 1 , January 2012, , Pages 40-49
Modeling and Simulation
Volume 7, Issue 4 , October 2010, , Pages 42-49
Transport Phenomena,
A. R. Bahramian
Volume 12, Issue 1 , January 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.
Modeling and Simulation
Volume 9, Issue 2 , April 2012, , Pages 43-53
Transport Phenomena,
Volume 8, Issue 4 , October 2011, , Pages 43-49
Biomedical and Biotechnology,
Volume 4, Issue 1 , January 2007, , Pages 43-53
Abstract
This investigation was designed to evaluate the effects of bioaugmentation on maintaining the system stability under shock loading conditions, standardizing the effluent, and improving the sludge settlement. In this study, phenol was chosen as a model of mono-aromatic compounds which are found commonly ...
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This investigation was designed to evaluate the effects of bioaugmentation on maintaining the system stability under shock loading conditions, standardizing the effluent, and improving the sludge settlement. In this study, phenol was chosen as a model of mono-aromatic compounds which are found commonly in many industrial wastewaters, especially petroleum refineries and the petrochemical industry in Iran. Impacts of bioaugmentation with the best isolated microorganism on the system performance facing sudden toxic shock were investigated after acclimatizing the system with phenol, isolating the phenol degrading microorganisms, and selecting the best phenol degrading strain. Results indicated that this method was improved the efficiency of the system under shock loading from 30% to 94% and SVI from 333 ml/g to 80 ml/g. The effluent was standardized after bioaugmentation at a minimum HRTs of 10, 10, 12 and 24 h, respectively, and at influent COD of 800, 1000, 1500 and 2000 mg/l. The system efficiency and SVI were located in an average range of 99.4-99.9% and 50-71 ml/g, respectively, and the sludge growth was good, even under high organic loading rates after bioaugmentation. In conclusion, bioaugmentation could be used as an effective and efficient method to improve a CAS process facing sudden toxic pollutant shock loading.
Transport Phenomena,
Volume 6, Issue 4 , October 2009, , Pages 44-61
Abstract
A numerical investigation was carried out to solve the flow dimensionless partial differential equations through rectangular microchannels. A purely viscous power law model was used to characterize the flow behavior of non-Newtonian fluids. The flow was assumed to be steady and laminar, and slip conditions ...
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A numerical investigation was carried out to solve the flow dimensionless partial differential equations through rectangular microchannels. A purely viscous power law model was used to characterize the flow behavior of non-Newtonian fluids. The flow was assumed to be steady and laminar, and slip conditions were used as boundary conditions at the walls. The problem was solved for different power law indices as well as for various rectangular aspect ratios. Results showed that the effects ofslip velocity on dilatant fluids are more pronounced than that for pseudoplastic fluids. An increase in the power law index enhances the product of the friction factor and the Reynolds number, as well as the dimensionless incremental pressure drop and the dimensionless maximum velocity, while the hydrodynamic entrance length decreases. Results emphasize the significant effects of channel aspect ratio on the hydrodynamic flow behavior through microchannels.
Modeling and Simulation
Volume 3, Issue 4 , October 2006, , Pages 44-59
Abstract
"> Accurate prediction of the minimum miscibility pressure (MMP) in a gas injection process is crucial to optimizing the management of gas injection projects. Because the experimental determination of MMP is very expensive and time-consuming, searching for a fast and robust mathematical determination ...
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"> Accurate prediction of the minimum miscibility pressure (MMP) in a gas injection process is crucial to optimizing the management of gas injection projects. Because the experimental determination of MMP is very expensive and time-consuming, searching for a fast and robust mathematical determination of CO2-oil MMP is usually requested. This paper presents a new model based on a hybrid neural-genetic algorithm for predicting pure and impure CO2-oil MMP. The CO2-oil MMP of a reservoir fluid was correlated with the reservoir temperature, the composition of the oil, and that of the solution gas. The developed model is able to reflect the impacts on the CO2–oil MMP of the molecular weight of the C5+ fraction, reservoir temperature, and solution gas in the oil. The validity of this new model was successfully approved by comparing the model results to the calculated results for the common pure and impure CO2-oil MMP correlations. The new model yielded the accurate prediction of the experimental slim-tube CO2-oil MMP with the lowest mean absolute percentage error (MAPE), the standard deviation of error (SD), the root mean square error (RMSE), and the highest correlation coefficient among tested impure and pure CO2-oil MMP correlations. The results demonstrate that the hybrid neural-genetic model can be applied successfully and provide high accuracy and reliability for MMP forecasting.
Polymer Engineering and Technology,
Volume 11, Issue 3 , July 2014, , Pages 45-58
Biomedical and Biotechnology,
Volume 1, Issue 1 , April 2004, , Pages 47-56
Process Control and Engineering, Process Safety, HSE
Volume 9, Issue 3 , July 2012, , Pages 48-54
Reaction Engineering, Kinetics and Catalysts,
Volume 8, Issue 3 , July 2011, , Pages 48-54
Modeling and Simulation
Volume 9, Issue 4 , October 2012, , Pages 49-53
Separation Technology,
Volume 2, Issue 2 , April 2005, , Pages 49-55
Abstract
An efficient microbial technique for decolorizing distillery wastewater was achieved using irradiated spores of Aspergillus fumigatus. The fungus was isolated from soil samples taken from the local distillery processing unit. By using the irradiated spores, wastewater decolorization increased by 14.3% ...
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An efficient microbial technique for decolorizing distillery wastewater was achieved using irradiated spores of Aspergillus fumigatus. The fungus was isolated from soil samples taken from the local distillery processing unit. By using the irradiated spores, wastewater decolorization increased by 14.3% as compared to that of the control treatment (68.8% vs. 54.5%). In the presence of sodium nitrate and maltose, as optimum sources of nitrogen and carbon, in the microbe's growth medium, the decolorization rose to 70%.
Modeling and Simulation
Volume 6, Issue 1 , January 2009, , Pages 50-65
Process Control and Engineering, Process Safety, HSE
Volume 6, Issue 2 , April 2009, , Pages 50-62
Biomedical and Biotechnology,
F. Ghavipanjeh*; M. Pazouki; Z. Ziaei Rad; A. Hosseinnia
Volume 12, Issue 2 , April 2015, , Pages 50-58
Abstract
"> Long-chain alkanes are a major constituent of crude oils and their conversions into other compounds are of interest depending on the specific application. Here, five native microbial consortia obtained from petroleum polluted sites were examined for biological conversion of n-octadecane as a representative ...
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"> Long-chain alkanes are a major constituent of crude oils and their conversions into other compounds are of interest depending on the specific application. Here, five native microbial consortia obtained from petroleum polluted sites were examined for biological conversion of n-octadecane as a representative of long chain alkanes. The experiments were implemented in 250 mL flasks containing 0.5 g n-octadecane in 40 mL culture media kept on a shaker at 160 rpm and 30C for one week. A pure culture of Psedumonas putida was inoculated at the same condition for comparison. Amongst the consortia, ABN52 imposed more obvious changes on n-octadecane. The GC-MS analysis of daily samples showed the appearance of lighter branched compounds at the first and second days of incubation but disappeared in the following days. At the end of incubation time up to 20 (w/w%) of the initial substrate was turned into polyhydroxyalkanoates (PHAs). It also suggested higher activity of the consortia compared to the pure culture of Psedumonas putida. Keywords: Bioconversion, Aalkanes, Polyhydroxyalkanoate, PHA, Pseudomonas Putida
Materials synthesize and production
Volume 10, Issue 3 , July 2013, , Pages 51-59
Reaction Engineering, Kinetics and Catalysts,
Volume 7, Issue 2 , April 2010, , Pages 51-57
Separation Technology,
Volume 5, Issue 1 , January 2008, , Pages 51-64
Abstract
> In this paper a chemical method applied to synthesize exfoliated graphite (EG) is presented. In this method graphite intercalation compound (GIC) was firstly synthesized by chemical treatment of graphite flakes using a mixture of sulfuric and nitric acids followed by thermal shock of GIC at 1000°C ...
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> In this paper a chemical method applied to synthesize exfoliated graphite (EG) is presented. In this method graphite intercalation compound (GIC) was firstly synthesized by chemical treatment of graphite flakes using a mixture of sulfuric and nitric acids followed by thermal shock of GIC at 1000°C to produce EG. The bulk density of synthesized EG was found to be as low as 4.5 kg/m3. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were used for identification and characterization of different materials. According to the XRD observations, the GIC was identified as graphite bisulfate with stage 2, and residue GIC and EG had nearly the same diffraction pattern, but with distinctly lower intensity. In accordance with SEM results the residue graphite bisulfate was swelled in comparison with the graphite flake. The oil sorption capacity of synthesized EG in this work was studied by common static and dynamic tests and compared with other sorbents. The results show the superior capability of EG for oil spill cleanup.
Modeling and Simulation
Volume 3, Issue 3 , July 2006, , Pages 51-64
Abstract
In this research, Fischer Tropsch synthesis (FTS) has been modeled in the fixed bed chromatographic reactor for the first time by applying a rather complex dispersed plug flow model for fluid phase and linear driving force (LDF) model for adsorbent. Model equations are dynamic, multi-component, non-linear ...
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In this research, Fischer Tropsch synthesis (FTS) has been modeled in the fixed bed chromatographic reactor for the first time by applying a rather complex dispersed plug flow model for fluid phase and linear driving force (LDF) model for adsorbent. Model equations are dynamic, multi-component, non-linear and heterogeneous including reaction and adsorption simultaneously Complex kinetics for FTS and water-gas shift (WGS) reaction and the multicomponent Langmuir adsorption isotherm is used in the model. A set of partial differential and ordinary differential equations with algebraic equations have been converted into a set of ordinary differential equations by using the orthogonal collocation technique. Then this set of equations has been solved by multi-step methods of Numerical Differentiation Formulae (NDF) or Backward Dif-ferentiation Formulae (BDF) Known as the Gear’s method. Consequently, results for dynamic model and effects of modeling parameters have been analyzed. Through this fixed bed chromatographic reactor model, one may develop a suitable configuration of simulated moving bed chromatographic reactors.
Thermodynamics,
Volume 5, Issue 3 , July 2008, , Pages 52-61
Abstract
Lennard-Jones-Devonshire equation of state is an old but theoretical based EOS. The concept of the nearest neighboring molecules or coordination number is proposed to be a function of temperature and volume, whereas it is a constant in the original. The dilute gas and hard sphere limits of molecules ...
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Lennard-Jones-Devonshire equation of state is an old but theoretical based EOS. The concept of the nearest neighboring molecules or coordination number is proposed to be a function of temperature and volume, whereas it is a constant in the original. The dilute gas and hard sphere limits of molecules are employed to determine this function. Improvement of this modification is demonstrated by property calculations for Lennard-Jones fluid. Results of the modified LJD equation of state offer senior accord with simulation data of Lennard-Jones fluid than those of the original version.