Search for: central-composite-designs
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    Application of face-centered central composite design (FCCCD) in optimization of enzymatic decolorization of two azo dyes: A modeling vs. empirical comparison

    , Article Progress in Color, Colorants and Coatings ; Volume 12, Issue 3 , 2019 , Pages 179-190 ; 20082134 (ISSN) Kashefi, S ; Borghei, S. M ; Mahmoodi, N. M ; Sharif University of Technology
    Institute for Color Science and Technology  2019
    Biological treatment, especially enzymatic methods, can be employed for effective and environmental- friendly treatment of dye effluents. Laccase, belonging to the blue multi-copper oxidases category, can oxidize a wide variety of substrates, especially synthetic dyes. In this study, laccase was used to biodegrade two azo dyes, i.e., Direct Red 23 and Acid Blue 92. Before conducting the experiments, the laccase used in this study was enzymatically characterized. Face-centered central composite design (FCCCD) was used to optimize the main parameters of the decolorization process. The optimum conditions to maximize the bio-decolorization process of AB92 were X1=11.85 mg L-1, X2=5.10, and... 

    Use of response surface methodology analysis for xanthan biopolymer production by xanthomonas campestris: focus on agitation rate, carbon source, and temperature

    , Article Iranian Journal of Chemistry and Chemical Engineering ; Volume 36, Issue 1 , 2017 , Pages 173-183 ; 10219986 (ISSN) Zakeri, A ; Pazouki, M ; Vossoughi, M ; Sharif University of Technology
    Jihad Danishgahi  2017
    The current study is an attempt to contribute for efficient and cost-effective substrates for xanthan gum production. In this context, the sugar cane molasses wastes can be used as a cheap substrate for xanthan gum production. Xanthan biopolymer production by a novel Xanthomonas campestris strain IBRC-M 10644 was optimized with statistical approaches. Based on the results of Response Surface Methodology (RSM) with Central Composite Design (CCD) technique, a second-order polynomial model was developed and evaluated the effects of variables on the maximum xanthan production. Agitation rate (X1: 200-500 rpm), sugar cane molasses concentration (X2: 30-90 g/L) and operation temperature (X3: 25-35... 

    Electrodeposition of the Ni-Cr Alloy by Pulse Plating

    , M.Sc. Thesis Sharif University of Technology Imanieh, Iman (Author) ; Dolati, Abolghasem (Supervisor) ; Mohammadi, Mohammad Reza (Supervisor)
    In this thesis, the hardness of Ni-Cr alloys is optimized by design of experiment (DOE) method (Central Composite Design) in pulse electrodeposition performed in chloride solution. Various parameters were evaluated for finding significant factors in pulse electrodeposition of Ni-Cr alloy. Frequency, duty cycle, current density and temperature were selected as effective factors. 30 experiments were designed by the central composite design method. Analyses of Variance (ANOVA) were performed on the results of these 30 experiments. The best models which can predict the hardness, Cr content, deposition rate, thickness and cathode efficiency of Ni-Cr alloy electrodeposits were found and... 

    Minimizing CO2 formation in Ir-catalyzed methanol carbonylation process

    , Article 20th International Congress of Chemical and Process Engineering, CHISA 2012, Prague, 25 August 2012 through 29 August 2012 ; 2012 , Pages 1179-1188 ; 18777058 (ISSN) Kazemeini, M ; Hosseinpour, V ; Sharif University of Technology
    Acetic acid is one of the most important petrochemical products. Carbonylation of methanol in homogenous phase is one of the major routes for production of acetic acid. Amongst group VIII metal catalysts used in this process iridium has displayed the best capabilities. To investigate effect of operating parameters like: temperature, pressure, methyl iodide, methyl acetate, iridium, ruthenium, and water concentrations on the carbon dioxide formation, experimental design for this system based upon central composite design (CCD) was utilized. Statistical carbon dioxide formation equation developed by this method contained individual, interactions and curvature effects of parameters on the... 

    Optimization of particle size and specific surface area of pellet feed in dry ball mill using central composite design

    , Article Indian Journal of Science and Technology ; Volume 9, Issue 44 , 2016 ; 09746846 (ISSN) Abazarpoor, A ; Halali, M ; Sharif University of Technology
    Indian Society for Education and Environment  2016
    Objective: The dimensional properties of iron ore pellet feed including specific surface area and particle size distribution in the ball mill was studied using response surface area method. Methods/Statistical analysis: The effect of the operational parameters of dry ball mill including ball charge (20-40%), grinding time (30-50 min) and balling distribution (Small, Mixed and Large) on dimensional properties of pellet feed was meticulously examined and optimized using response surface methodology based on Central Composite Design (CCD). Responses were 80% passing size (D80) and Blaine (BL). A total of 30 grinding experiments were designed and carried out in the CCD method. Regression models... 

    Recovery of Rhenium From Produced Leaching Solution of Sarcheshmeh Molybdenite Concentrate

    , M.Sc. Thesis Sharif University of Technology Khosravi, Mohammad Hadi (Author) ; Yoozbashizadeh, Hossein (Supervisor)
    In this study, molybdenum and rhenium extraction from alkaline solution of electro-oxidation leachinng of Sarcheshmeh molybdenite concentrate by solvent extraction using organophosphorous organic solvents, under different conditions has been investigated. The studied variables were organic solvent concentration, ratio of organic phase to aqueous phase and pH. Design Expert software and Central Composite Design method was performed to evaluate the effect of parameters and optimize recovery conditions. Molybdenum was extracted via Di-2-EthyHexyl Phosphoric Acid (D2EHPA) organic solvent diluted in kerosene initially, in order to reduce molybdenum ions interruptions during extraction of rhenium.... 

    Biofuel Alcohol Production from Agricultural Residues in a Slurry Bioreactor

    , M.Sc. Thesis Sharif University of Technology Sattari, Behzad (Author) ; Vossoughi, Manoochehr (Supervisor) ; Alemzadeh, Iran (Supervisor)
    Nowadays bioethanol is one of the main factors in the fuel market. It is currently produced from sugars and starchy materials, but lignocelluloses can be expected to be major feedstocks for ethanol production in the future. Agricultural residues such as wheat straw are being considered a potential lignocellulose raw material for fuel-ethanol production as an alternative to starch or sugar-containing feedstock. In order to produce bioethanol, it is necessary to decompose the wheat straw into soluble sugars. But lignocellulosic materias needs pretreatment before hydrolysis and fermentation. The main goal of pretreatment is to increase the enzyme accessibility improving digestibility of... 

    Recovery of Gallium from Sodium Aluminate Solution in Bayer Process

    , M.Sc. Thesis Sharif University of Technology Habibi, Amir (Author) ; Yoozbashi Zadeh, Hossein (Supervisor)
    Gallium is a rare and precious metal that is of particular importance in the electronics industry due to its use in semiconductors. This metal is partially present in bauxite ore. Around 70% of gallium go into sodium aluminate solution during the leaching of bauxite in the Bayer process. Gallium can be extracted from this solution, which is also called bayer solution, by several methods. Solvent extraction is one of the most common methods for recovery of gallium from Bayer's solution. Capabilities of this method for metals separation and concentrating of polymetallic solution, makes it suitable for many commercial and operational application. In present work, different substances used to... 

    Evaluation of viscosity and thermal conductivity of graphene nanoplatelets nanofluids through a combined experimental–statistical approach using respond surface methodology method

    , Article International Communications in Heat and Mass Transfer ; Volume 79 , 2016 , Pages 74-80 ; 07351933 (ISSN) Iranmanesh, S ; Mehrali, M ; Sadeghinezhad, E ; Ang, B. C ; Ong, H. C ; Esmaeilzadeh, A ; Sharif University of Technology
    Elsevier Ltd 
    In the present study, three influential parameters including concentration, temperature and specific surface area of graphene nanosheets were investigated, which are the effective parameters on the viscosity and thermal conductivity of aqueous graphene nanosheets (GNP) nanofluids. A mathematical model developed by respond surface methodology (RSM) based on a central composite design (CCD). Also, the significance of the models was tested using the analysis of variance (ANOVA). The optimum results of aqueous GNP nanofluid showed that the concentration has a direct effect on the relative viscosity and thermal conductivity. Furthermore, predicted responses proposed by the Design Expert software... 

    Geometric optimization of a double pipe heat exchanger with combined vortex generator and twisted tape: A CFD and response surface methodology (RSM) study

    , Article Thermal Science and Engineering Progress ; Volume 18 , 2020 Arjmandi, H ; Amiri, P ; Saffari Pour, M ; Sharif University of Technology
    Elsevier Ltd  2020
    In this research, a numerical investigation is done on the effect of employing the new combined vortex generators, the twisted tape turbulator and Al2O3-H2O nanofluid as the involved base fluid. Such study is carried out on the behavior of the heat transfer rate and the pressure drop of a double pipe heat exchanger. Accordingly, the response surface methodology (RSM) grounded on the central composite design (CCD) is used for acquiring the optimized geometry of the combined vortex generator and twisted tape turbulator. In order to have the maximum Nusselt number and minimum friction factor, twenty cases with different pitches ratio Pil=0.09-0.18, angles (θ=0-30°) and Reynolds numbers (Re =... 

    Design of a pseudo stir bar sorptive extraction using graphenized pencil lead as the base of the molecularly imprinted polymer for extraction of nabumetone

    , Article Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy ; Volume 238 , 2020 Afsharipour, R ; Dadfarnia, S ; Haji Shabani, A. M ; Kazemi, E ; Sharif University of Technology
    Elsevier B.V  2020
    Molecularly imprinted polymer (MIP) was synthesized through the coprecipitation method on the graphene oxide anchored pencil lead as a substrate for the first time and applied as an efficient sorbent for pseudo stir bar sorptive extraction of nabumetone. The extracted analyte was determined by a novel spectrophotometric method based on the aggregation of silicate sol-gel stabilized silver nanoparticles in the presence of the analyte. The synthesized polymer was characterized using Fourier transform infrared spectroscopy and field emission scanning electron microscopy. Optimization of important parameters affecting the extraction efficiency was done using central composite design whereas the... 

    Vancomycin removal using TiO2–clinoptilolite/UV in aqueous media and optimisation using response surface methodology

    , Article International Journal of Environmental Analytical Chemistry ; 2022 ; 03067319 (ISSN) Dehghani, F ; Yousefinejad, S ; Dehghani, M ; Borghei, S. M ; Javid, A. H ; Sharif University of Technology
    Taylor and Francis Ltd  2022
    Investigations have shown the traces of antibiotics in surface water, groundwater, wastewater treatment plants, and drinking water. However, conventional wastewater treatment is not entirely effective for vancomycin degradation. Advanced oxidation is one of the most widespread methods of antibiotic degradation in aqueous media. Vancomycin was quantified by high-performance liquid chromatography. The Response Surface Methodology (RSM) based on Central Composite Design (CCD) was used to explore and optimise the effect of the independent variables on vancomycin degradation. Independent variables were as follows: pH (3–11), vancomycin concentration (15–75 mg/L), TiO2–clinoptilolite (25–125 mg in... 

    Evaluation of Aspergillus niger and Penicillium simplicissimum for their ability to leach Zn–Ni–Cu from waste mobile phone printed circuit boards

    , Article Journal of Material Cycles and Waste Management ; Volume 24, Issue 1 , 2022 , Pages 83-96 ; 14384957 (ISSN) Arshadi, M ; Esmaeili, A ; Yaghmaei, S ; Arab, B ; Sharif University of Technology
    Springer Japan  2022
    In this research, Zn, Ni, and Cu recovery from mobile phone printed circuit boards was investigated. The initial pH and pulp density using Aspergillus niger or Penicillium simplicissimum fungi were optimized to improve the recovery of Zn, Ni, and Cu using a central composite design. Fungi were able to recover 97% of Cu. Often for Ni recovery, A. niger was more effective, but in low pulp densities and low pH, P. simplicissimum was preferred. For recovery of Zn, A. niger is more appropriate at pH lower than 6, but P. simplicissimum outperforms at pH higher than 6. Under the optimum conditions (pulp density of 4 gL−1 and initial pH 10), the respective recovery of Cu, Ni, and Zn was determined... 

    Magnetic Nanocomposites Based on Bio-Degradable Polylactic Acid

    , M.Sc. Thesis Sharif University of Technology Shamshiri, Soodeh (Author) ; Frounchi, Masoud (Supervisor)
    In this work, magnetite (Fe3O4) nanoparticles with an average siz21.9nm
    modified by oleic acid were prepared by the coprecipitation method, which can linked well with organic molecules because of the presence of C-O-C on their surface. Then magnetic poly(lactic acid) (PLA)/ poly(ethylene glycol) (PEG) microspheres were prepared by the single emulsion solvent evaporation technology. The incorporation of magnetit nanoparticles and dox into the PLA matrix was confirmed by FTIR. XRD and VSM confirmed the existence of MNPs in the microspheres which maintained superparamagnetic behavior with a saturation magnetization of 50.69 emu/g.Electron microscopy SEM showed that the magnetic microspheres... 

    Application of Gold Nanoparticles for Simultaneous Determination of Polycyclic Aromatic Hydrocarbons in Water Samples with the Aid of Multivariate Chemometric Methods

    , M.Sc. Thesis Sharif University of Technology Rezaiyan, Mahsa (Author) ; Parastar Shahri, Hadi (Supervisor) ; Hormozi Nezhad, Mohammad Reza (Supervisor)
    In this study, a multivariate-based strategy was developed for simultaneous determination of thirteen carcinogenic polycyclic aromatic hydrocarbons (PAHs) in water samples using gold nanoparticles (AuNPs) as solid-phase extraction (SPE) sorbent combined with gas chromatography-flame ionization detector (GC-FID). The extraction technique is based on the strong affinity between citrate capped AuNPs and PAHs. Furthermore, characterization of AuNPs was performed by UV-Vis and TEM techniques. A rotatable central composite design (CCD) combined with multiple linear regression (MLR) was used for designing the extraction procedure and developing models using the GC peak areas of 13 PAHs. Also,... 

    Development and Application of Multivariate Calibration Methods Combined with Gas Chromatography for Simultaneous Determination of Organophosphorous Pesticides in Complex Matrices

    , M.Sc. Thesis Sharif University of Technology Balsini, Parvaneh (Author) ; Parastar Shahri, Hadi (Supervisor)
    In this study, a new strategy based on chemometrics and extraction method of Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) combined with dispersive liquid–liquid micro-extraction (DLLME) in addition gas chromatography-flame ion detector (GC-FID) has been developed for the determination of ten pesticides in complex samples (such as tap water and milk).In this regard, experiments were designed, modeled and optimum condition was achieved by using central composite design (CCD), backward multiple linear regression (MLR) and Nelder-Mead simplex optimization. On this matter, 36 experiments for 5 extraction factors in 5 levels were generated. Also, multi-response optimization using... 

    Kinetic Study of Carbonylation of Methanol Using Homogenous Iridium Catalyst

    , M.Sc. Thesis Sharif University of Technology Hosseinpour, Vahid (Author) ; Kazemeini, Mohammad (Supervisor) ; Mhammad Rezaee, Alireza (Supervisor)
    Homogenous carbonylation of methanol is a major way to acetic acid. In this study central composite design (CCD) at five level (-1.63, -1, 0, +1, +1.63) combined with response surface methodology (RSM) have been applied to optimize carbonylation of methanol using ruthenium promoted iridium catalyst in homogenous phase. The effect of seven process variables including; temperature, pressure, iridium, ruthenium, methyl iodide, methyl acetate and water concentrations as well as, their interactions were modeled. The determined R2 values greater than 0.9 for the rate, methane, carbon dioxide and hydrogen formation data, confirmed quadratic equation properly fitted obtained experimental data. The... 

    Kinetic Evaluations, Economical and Scale-up Studies of the Co-Mo/Ɣ-Al2O3Catalyst for Hydrodesulfurization (HDS) Process

    , M.Sc. Thesis Sharif University of Technology Oghabi Sajjadi, Mohammad Hossein (Author) ; Kazemeini, Mohammad (Supervisor) ; Khorashe, Farhad (Supervisor)
    Sulfur compounds are very undesirable and result in Corrosion in metal equipment, air pollutions and poisoning of refinery Catalysts such as reforming Catalyst. Therefore, application of Hydrodesulfurization (HDS) process in order to decrease the amount of sulfur in petroleum cuts has a great importance. HDS process is the most usual and efficientmethod for sulfur removal. In this method sulfur compounds at vigorous operating conditions such as high temperature and pressure in the presence of catalyst react with hydrogen and produce hydrogen disulfide and hydrocarbon. Sulfided Co–Mo catalysts are widely used in this process.
    The aim of this study is to prepare and improve CoMo/γ-Al2O3... 

    Investigation of the Effect of Asphaltene on the Stability of Water-oil Emulsion

    , M.Sc. Thesis Sharif University of Technology Hosseini, Amir (Author) ; Taghikhani, Vahid (Supervisor) ; Baghban Salehi, Mahsa (Supervisor) ; Masihi, Mohsen (Supervisor)
    During the production of crude oil from reservoirs, the production of quantities of formation water along with this oil, causes the crude oil does not have the necessary indicators for transportation, refining and ultimately export. The presence of water and salt along with crude oil causes corrosion of refinery and transmission equipment and makes oil unfavorable in terms of economic efficiency (both for domestic use and for export). water and salt produce stable emulsion with oil that can be stable for a long time and can not be easily separated from crude oil. Therefore, separation of water and salt from crude oil is one of the most important issues in the oil industry. Breaking this... 

    Optimization of biodiesel production by alkali-catalyzed transesterification of used frying oil

    , Article Process Safety and Environmental Protection ; Vol. 92, issue. 2 , 2014 , pp. 179-185 ; ISSN: 09575820 Atapour, M ; Kariminia, H. R ; Moslehabadi, P. M ; Sharif University of Technology
    Biodiesel as an alternative fuel for fossil diesel has many benefits such as reducing regulated air pollutants emissions, reducing greenhouse gases emissions, being renewable, biodegradable and non-toxic. In this study, used frying oil was applied as a low cost feedstock for biodiesel production by alkali-catalyzed transesterification. The design of experiments was performed using a double 5-level-4-factor central composite design coupled with response surface methodology in order to study the effect of factors on the yield of biodiesel and optimizing the reaction conditions. The factors studied were: reaction temperature, molar ratio of methanol to oil, catalyst concentration, reaction time...