Search for: response-surface-methodology
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    Design and fabrication of conductive nanofibrous scaffolds for neural tissue engineering: Process modeling via response surface methodology

    , Article Journal of biomaterials applications ; Volume 33, Issue 5 , 2018 , Pages 619-629 ; 15308022 (ISSN) Soleimani, M ; Mashayekhan, S ; Baniasadi, H ; Ramazani, A ; Ansarizadeh, M ; Sharif University of Technology
    NLM (Medline)  2018
    Peripheral nervous system in contrary to central one has the potential for regeneration, but its regrowth requires proper environmental conditions and supporting growth factors. The aim of this study is to design and fabricate a conductive polyaniline/graphene nanoparticles incorporated gelatin nanofibrous scaffolds suitable for peripheral nervous system regeneration. The scaffolds were fabricated with electrospinning and the fabrication process was designed with Design-Expert software via response surface methodology. The effect of process parameters including applied voltage (kV), syringe pump flow rate (cm3/h), and PAG concentration (wt%), on the scaffold conductivity, nanofibers diameter,... 

    Suppressed acrylamide formation during baking in yeast-leavened bread based on added asparaginase, baking time and temperature using response surface methodology

    , Article Applied Food Biotechnology ; Volume 5, Issue 1 , 2018 , Pages 29-36 ; 23455357 (ISSN) Matouri, M ; Alemzadeh, I ; Sharif University of Technology
    National Nutrition and Food Technology Research Institute  2018
    Background and Objective: Acrylamide as a toxic substance for human beings is produced by Maillard reaction at high temperatures. In this research, this reaction can be inhibited based on using aspariganse enzyme, controlling the cooking time and temperature during baking in yeast-leavened bread. Materials and Methods: In this study, a response surface methodology 5-level-3-factor central composite design was applied to study the effects of asparaginase (300-900 U Kg-1 of flour), baking temperature (230-280°C) and baking time (13-16 min) on acrylamide formation in yeast-leavened wheat bread. Results and Conclusion: Added asparaginase showed a reducing effect on acrylamide formation... 

    Adsorption and oxidation of dye and tetracycline over hydrothermally synthesized polyresorcinol – Ferrite nanoparticles

    , Article Desalination and Water Treatment ; Volume 212 , 2021 , Pages 376-389 ; 19443994 (ISSN) Kaveh, R ; Alijani, H ; Hossein Beyki, M ; Jafari Pirouz, M ; Sharif University of Technology
    Desalination Publications  2021
    This study focuses on developing an efficient material that integrates high adsorption performances of dye and antibiotics as well as effective oxidation activity of it. Herein, we report a facile method to synthesize polyresorcinol@CoFe2 O4 via a one-step hydrothermally route. The prepared composite possesses multifunctional performance for methylene blue (MB) and tetracycline (TC) removal with appropriate magnetic separation operation and significant removal ability with an adsorption capacity of 51.48 and 28.16 mg g–1, respectively. Meanwhile, the aforementioned composite exhibits a high oxidation activity toward MB and TC molecules where the adsorption capacity increases to 1,723 and 120... 

    Biodegradation of cyanide by a new isolated strain under alkaline conditions and optimization by response surface methodology (RSM)

    , Article Journal of Environmental Health Science and Engineering ; Vol. 12, issue. 1 , 2014 Mirizadeh, S ; Yaghmaei, S ; Nejad, Z. G ; Sharif University of Technology
    Background: Biodegradation of free cyanide from industrial wastewaters has been proven as a viable and robust method for treatment of wastewaters containing cyanide. Results: Cyanide degrading bacteria were isolated from a wastewater treatment plant for coke-oven-gas condensate by enrichment culture technique. Five strains were able to use cyanide as the sole nitrogen source under alkaline conditions and among them; one strain (C2) was selected for further studies on the basis of the higher efficiency of cyanide degradation. The bacterium was able to tolerate free cyanide at concentrations of up to 500 ppm which makes it a good potentially candidate for the biological treatment of cyanide... 

    Comparative photodecolorization of red dye by anatase, rutile (TiO 2), and wurtzite (ZnO) using response surface methodology

    , Article Turkish Journal of Chemistry ; Volume 36, Issue 1 , 2012 , Pages 121-135 ; 13000527 (ISSN) Asl, S. K ; Sadrnezhaad, S. K ; Rad, M. K ; Üner, D ; Sharif University of Technology
    Treatment of dye pollution containing C.I. Acid Red 14 (AR14) by a coupled photocatalytic process was studied. Titanium dioxide, in the form of anatase and rutile, and zinc oxide, were used as photocatalysts. The investigated photocatalysts were Aldrich-produced nanopowders with crystallites of a mean size of 20-30 nm and a specific surface area of about 50 m 2/g. A comparison of TiO 2(anatase), TiO 2(rutile), TiO 2(a,r), and ZnO for the decolorization of the AR14 solution was performed. Results showed that color removal followed the decreasing order of TiO 2(a,r), ZnO > TiO 2(a,r) > TiO 2(a), ZnO > TiO 2(r), ZnO >TiO 2(a,r) > TiO 2(a) > ZnO > TiO 2(r). Response surface methodology (RSM) was... 

    Optimization of catalytic activity of sulfated titania for efficient synthesis of isoamyl acetate by response surface methodology

    , Article Monatshefte fur Chemie ; Volume 146, Issue 12 , December , 2015 , Pages 1949-1957 ; 00269247 (ISSN) Afshar, S ; Sadehvand, M ; Azad, A ; Dekamin, M. G ; Jalali Heravi, M ; Mollahosseini, A ; Amani, M ; Tadjarodi, A ; Sharif University of Technology
    Springer-Verlag Wien  2015
    TiO2 nanoparticles were synthesized by sol-gel method using titanium tetraisopropoxide. Sulfate ions were introduced on the titania by impregnation method using sulfuric acid as precursor of sulfate ions. Fourier transform infrared and energy-dispersive X-ray spectroscopy, X-ray fluorescence as well as X-ray diffraction, scanning electron microscopy, and BET methods were used for the characterization of the obtained nanoparticles. The esterification of isoamyl alcohol with acetic acid was investigated to prove the catalytic activity of the TiO2 nanoparticles under solvent-free conditions. Response surface methodology was applied to optimize the effect of some parameters such as the molar... 

    Process optimization and modeling of anaerobic digestion of cow manure for enhanced biogas yield in a mixed plug-flow reactor using response surface methodology

    , Article Biosciences Biotechnology Research Asia ; Volume 12, Issue 3 , 2015 , Pages 2333-2344 ; 09731245 (ISSN) Rasouli, M ; Ajabshirchi, Y ; Mousavi, S. M ; Nosrati, M ; Yaghmaei, S ; Sharif University of Technology
    Oriental Scientific Publishing Company  2015
    Pilot scale experiments were performed on the digestion of dairy cow manure in a semi-continuous process using a mixed plug flow reactor (MPFR) to determine the effects of organic loading rate (OLR), temperature and mixing levels on production biogas and methane yield. Response surface methodology (RSM) was applied for the design and analysis of experiments with the optimization of OLR, temperature and mixing level during the biogas production process. Experiments were designed as per the central composite design technique. Four cubic mathematical models were derived for prediction of the responses. The optimization study has been carried out to identify the highest yields achievable when... 

    High flux electrospun nanofiberous membrane: Preparation by statistical approach, characterization, and microfiltration assessment

    , Article Revista Mexicana de Urologia ; Volume 76, Issue 1 , 2016 , Pages 474-483 ; 01854542 (ISSN) Seyed Shahabadi, S. M ; Mousavi, S. A ; Bastani, D ; Sharif University of Technology
    Elsevier Doyma Mexico  2016
    Preparation, characterization and evaluation of new generation of micro-filters based on polyacrylonitrile electrospun nanofiberous membrane (ENM) were thoroughly investigated. First, quantitative relationships between average diameter, bead area density of nano-fibers and certain electrospinning parameters, i.e., concentration, voltage, spinning distance, and feed rate, were established by empirical modeling based on a central composite design. The analysis revealed that concentration, voltage and distance are the significant parameters. Also, adequacy checking indicated the appropriateness of fit for the models. Afterwards, bead-free ENMs with diameter of 100-500 nm were prepared and... 

    Humic acid removal from water using a novel fabricated antifouling carbon nanotube bucky - paper membrane and effect of operating parameters

    , Article Global Nest Journal ; Volume 19, Issue 2 , 2017 , Pages 217-224 ; 17907632 (ISSN) Jafari, A ; Nasseri, S ; Nabizadeh, R ; Mousavi, S. A ; Rezaee, R ; Mahvi, A. H ; Sharif University of Technology
    Global NEST  2017
    In present work, a novel supported bucky paper (BP) membrane was fabricated and evaluated for humic acid (HA) removal from water. For better understanding the effect of operating variables, response surface methodology (RSM) was also applied. Three independent parameters namely TOC concentration (5, 10 and 15 mg l-1), operating time (10, 20 and 30 min) and transmembrane pressure (TMP) (1, 2 and 3 bar) were selected for TOC removal (%) and permeate flux analysis. The results revealed that the membrane could effectively remove HA primarily through electrostatic repulsion and then adsorption mechanisms. The study also showed that about 65% and 35% of the removed HA were through repulsion and... 

    Superparamagnetic enzyme-graphene oxide magnetic nanocomposite as an environmentally friendly biocatalyst: Synthesis and biodegradation of dye using response surface methodology

    , Article Microchemical Journal ; Volume 145 , 2019 , Pages 547-558 ; 0026265X (ISSN) Kashefi, S ; Borghei, S. M ; Mahmoodi, N. M ; Sharif University of Technology
    Elsevier Inc  2019
    The unique properties of graphene oxide (GO) nanosheets were integrated with the superparamagnetic characteristics of the CuFe2O4 nanoparticles to synthesize the magnetic graphene oxide (MGO), which was chemically modified with 3-amino propyl trimethoxy silane (APTMS) to functionalize the amine group on MGO (MGO-NH2). Afterward, MGO-NH2 was activated with glutaraldehyde (GLU) as a crosslinking agent to synthesize the functionalized MGO (fMGO) and its capability toward covalent Laccase immobilization was investigated. The comprehensive structural analysis using various characterization techniques, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), vibrating... 

    L-sorbose production by gluconobacter oxydans using submerged fermentation in a bench scale fermenter

    , Article Applied Food Biotechnology ; Volume 7, Issue 1 , 2020 , Pages 41-48 Alizad Derakhshi Azar, S ; Alemzadeh, I ; Sharif University of Technology
    National Nutrition and Food Technology Research Institute  2020
    Background and objective: L-Sorbose, as a precursor of ascorbic acid, can be biologically produced using Gluconobacter oxydans. The aim of this study was to optimize production of L-Sorbose by controlling concentration of the substrates and starter cultures. Material and methods: In this study, effects of three various fermentation parameters on the concentration of L-sorbose were assessed using fermenter (28°C, 1.4 vvm) and response surface methodology. These parameters included quantities of D-sorbitol (120-180 g lDw-1) (Deionized water) and yeast extract (6-18 g lDw-1) and inoculum/substrate ratios (5-10%). Results and conclusion: Results showed that the fitted model with high values of... 

    Biodegradation of 4-chlorobenzoic acid by lysinibacillus macrolides DSM54T and determination of optimal conditions

    , Article International Journal of Environmental Research ; Volume 14, Issue 2 , 2020 , Pages 145-154 Samadi, A ; Sharifi, H ; Ghobadi Nejad, Z ; Hasan Zadeh, A ; Yaghmaei, S ; Sharif University of Technology
    Springer  2020
    Chlorobenzoic acids (CBAs) are recalcitrant and toxic materials which enter the environment directly using pesticides and herbicides, or indirectly through the biodegradation of polychlorinated biphenyl (PCB) compounds. In the conducted study, biodegradation of 4-chlrobenzoic acid was investigated by Lysinibacillus macrolides DSM54T, which had previously been isolated from PCB-polluted soils. Environmental factors including pH, temperature, 4-CBA concentration and inoculation percentage were optimized using response surface methodology (RSM). 58 experiments were designed according to Historical Data, because of the arbitrary selection of experiments, and the combined effects of the... 

    A robust multi-objective optimization model for project scheduling considering risk and sustainable development criteria

    , Article Environment, Development and Sustainability ; Volume 23, Issue 8 , 2021 , Pages 11494-11524 ; 1387585X (ISSN) Askarifard, M ; Abbasianjahromi, H. R ; Sepehri, M ; Zeighami, E ; Sharif University of Technology
    Springer Science and Business Media B.V  2021
    There is limited research that considers the sustainability aspect of the projects’ schedule. The present study proposes a model to cover this gap by considering sustainable development criteria. A multi-objective model with four objective functions, including minimizing cost, risk, and socio-environmental impacts, has been presented to decrease the project’s delay. Since some of the parameters are considered under conditions of uncertainty for the proximity of problems to real projects, the robust programming method is used to deal with the uncertainty, and the epsilon-constraint method was applied to solve the multi-objective model. Several scenarios are also defined to analyze the... 

    Synthesis of Ni-Co-CNT nanocomposite and evaluation of its photocatalytic dye (Reactive red 120) degradation ability using response surface methodology

    , Article Desalination and Water Treatment ; Volume 216 , 2021 , Pages 389-400 ; 19443994 (ISSN) Shokrgozar, A ; Seifpanahi Shabani, K ; Mahmoodi, B ; Mahmoodi, N. M ; Khorasheh, F ; Baghalha, M ; Sharif University of Technology
    Desalination Publications  2021
    Herein, NiO and Co2 O3, NiCo2 O4, and NiCo2 O4 /multi-walled carbon nanotubes nanocomposite were synthesized by the hydrothermal method and characterized by scanning electron micros-copy, energy dispersive spectroscopy, and X-ray diffraction. The photocatalytic activity of the synthesized materials was evaluated by Reactive Red 120 dye degradation. The photocatalytic activity of NiO and Co3 O4 was enhanced not only by the formation of NiCo2 O4, but also by its interaction with the functionalized multiwall carbon nanotubes support. The response surface methodology (RSM) was used to obtain the optimum parameters, including catalyst dosage, initial dye concen-tration, and pH on the dye... 

    Robust parameter design using the weighted metric method-the case of 'the smaller the better'

    , Article International Journal of Applied Mathematics and Computer Science ; Volume 19, Issue 1 , 2009 , Pages 59-68 ; 1641876X (ISSN) Kamali Ardakani, M ; Noorossana, R ; Akhavan Niaki, T ; Lahijanian, H ; Sharif University of Technology
    In process robustness studies, it is desirable to minimize the influence of noise factors on the system and simultaneously determine the levels of controllable factors optimizing the overall response or outcome. In the cases when a random effects model is applicable and a fixed effects model is assumed instead, an increase in the variance of the coefficient vector should be expected. In this paper, the impacts of this assumption on the results of the experiment in the context of robust parameter design are investigated. Furthermore, two criteria are considered to determine the optimum settings for the control factors. In order to better understand the proposed method and to evaluate its... 

    An efficient economic-statistical design of simple linear profiles using a hybrid approach of data envelopment analysis, Taguchi loss function, and MOPSO

    , Article Journal of Optimization in Industrial Engineering ; Volume 13, Issue 1 , 2020 , Pages 99-112 Fazeli Moghadam, M ; Ershadi, M. J ; Akhavan Niaki, S. T ; Sharif University of Technology
    Qazvin Islamic Azad University  2020
    Statistically constrained economic design for profiles usually refers to the selection of some parameters such as the sample size, sampling interval, smoothing constant, and control limit for minimizing the total implementation cost while the designed profiles demonstrate a proper statistical performance. In this paper, the Lorenzen-Vance function is first used to model the implementation costs. Then, this function is extended by the Taguchi loss function to involve intangible costs. Next, a multi-objective particle swarm optimization (MOPSO) method is employed to optimize the extended model. The parameters of the MOPSO are tuned using response surface methodology (RSM). In addition, data... 

    Uranium Bioleaching from a Low Grade Ore

    , Ph.D. Dissertation Sharif University of Technology Rashidi, Abbas (Author) ; Roosta Azad, Reza (Supervisor) ; Safdari, Jaber (Supervisor)
    In this work, bioleaching was used to extract valuable uranium from a low grade ore. Bioleaching experiments were carried out in batch cultures using a native strain of Acidithiobacillus ferrooxidans. Experiments were conducted to investigate the effects of rotation speed, initial redox potential, initially added Fe concentration, particle size, pH, temperature, pulp density, and culture type. In the shake flask systems, over 99% of the uranium was bioleached in 48 hours at some conditions. Uninoculated flasks gave only around 25% leaching. At each study, uranium and iron concentrations, solution oxidation– reduction potential and pH were measured. The results showed that 150 rpm, d80=100 ... 

    Preparing a Coated Tablet of Vitamin C

    , M.Sc. Thesis Sharif University of Technology Rastegar, Mehrnoush (Author) ; Alemzadeh, Iran (Supervisor)
    Vitamin C is one of the essential ingredients for the survival of human beings, animals and plants. This vitamin is an ester that in its structure there is a cyclic ester, an alkene Factor (C = C) and four hydroxyl factor (OH). This vitamin is a white solid, water-soluble and non-toxic that exists in many fruits, especially citrus. Its presence in the diet of human resistance them against infections increases. The main factor causing acidic property in vitamin C is the presence of OH groups attached to the alkene. Various forms of vitamin C exists in pharmaceutical collection of European countries. Since the tablet form because of the many advantages including being economical compared with... 

    Production of biodiesel from waste frying oil using whole cell biocatalysts: Optimization of effective factors

    , Article Waste and Biomass Valorization ; Vol. 5, issue. 6 , 2014 , pp. 947-954 ; ISSN: 18772641 Ghaderinezhad, F ; Kariminia, H. R ; Yaghmaei, S ; Sharif University of Technology
    Using whole cell as a catalyst of enzymatic transesterification is a method to produce biodiesel with fewer drawbacks and at a lower cost. In the present study, biodiesel was produced by the reaction of waste frying oil with methanol in the presence of Rhizopus oryzae PTCC 5174 in both immobilized and free forms. Effect of four influencing factors including temperature, methanol to oil molar ratio, amount of biomass, and shaking speed was investigated. Response surface methodology was used to find the optimum conditions of the transesterification reaction. Each factor was set at three levels and the yield of the biodiesel was considered as the response. A quadratic equation was well-fitted... 

    An efficient approach to cathode operational parameters optimization for microbial fuel cell using response surface methodology

    , Article Journal of Environmental Health Science and Engineering ; Vol. 12, issue. 1 , 2014 Hosseinpour, M ; Vossoughi, M ; Alemzadeh, I ; Sharif University of Technology
    Background: In the recent study, optimum operational conditions of cathode compartment of microbial fuel cell were determined by using Response Surface Methodology (RSM) with a central composite design to maximize power density and COD removal. Methods: The interactive effects of parameters such as, pH, buffer concentration and ionic strength on power density and COD removal were evaluated in two-chamber microbial batch-mode fuel cell. Results: Power density and COD removal for optimal conditions (pH of 6.75, buffer concentration of 0.177 M and ionic strength of cathode chamber of 4.69 mM) improve by 17 and 5%, respectively, in comparison with normal conditions (pH of 7, buffer concentration...