Comparative Study on Design of Experiment in Frequency-Based Response Surface Methodology for Damage Detection

2015 ◽  
Vol 735 ◽  
pp. 168-173 ◽  
Author(s):  
Sarehati Umar ◽  
Norhisham Bakhary ◽  
Airil Yasreen Mohd Yassin

This paper investigates the performance of design of experiment (DOE) in response surface methodology (RSM) for vibration-based damage detection. The ability of three major types of DOE, namely central composite design (CCD), Box-Behnken (BBD) and D-optimal (Dopt) for damage detection based on modal frequency are investigated and compared. A procedure comprising three main stages—sampling, response surface (RS) modelling and model updating—are employed for damage localisation and quantification. By considering Young’s modulus and modal frequency as respective input and output, a set of samples is generated from each DOE. Full quadratic functions are considered in RS modelling while model updating is performed for damage detection. The performances of DOE are compared based on damage detectability. A numerical simply supported beam is used as case study by considering several single damage cases. The results show that CCD provides better prediction compared to other DOEs.

Author(s):  
K. Boujounoui ◽  
A. Abidi ◽  
A. Baçaoui ◽  
K. El Amari ◽  
A. Yaacoubi

SYNOPSIS Response surface methodology (RSM), central composite design (CCD), and desirability functions were used for modelling and optimization of the operating factors in chlorite and talc (collectively termed 'mica') flotation. The influence of pulp pH, cyanide (NaCN) consumption, and particle size was studied with the aim of optimizing ssilicate flotation while minimizing recoveries of galena, chalcopyrite, and sphalerite. Flotation tests were carried out on a representative sample of a complex sulphide ore from Draa Sfar mine (Morocco). The model predictions for the flotation of each of the minerals concerned were found to be in good agreement with experimental values, with R2 values of 0.91, 0.98, 0.99, and 0.90 for mica, galena, chalcopyrite, and sphalerite recoveries, respectively. RSM combined with desirability functions and CCD was successfully applied for the modelling of mica flotation, considering simultaneously the four flotation responses to achieve the maximum recovery of mica and minimal loss of Pb, Cu, and Zn to the flotation concentrate. Keywords: chlorite, talc, flotation, response surface methodology, central composite design, optimization.


2018 ◽  
Vol 17 (4) ◽  
pp. 349-354
Author(s):  
Qadir Rahman ◽  
Anwar Farooq ◽  
Amjad Gilani Mazhar ◽  
Nadeem Yaqoob Muhammad ◽  
Ahmad Mukhtar

This study investigates the effect of enzyme formulations (Zympex-014, Kemzyme dry-plus and Natuzyme) on recovery of phenolics from Peganum hermala (harmal) leaves, under optimized conditions using response surface methodology. As compared to the other enzyme complexes, the yield (34 g/100g) obtained through Zympex-014-assisted extraction was higher under optimized conditions such as time (75 min), temperature (70°C), pH (6.5) and enzyme concentration (5 g/100 g) using central composite design (CCD). Effectiveness of Zympex-014 towards hydrolysis of P. hermala leaves cell wall was examined by analyzing the control and enzyme-treated leave residues using scanning electron microscope (SEM). GC/MS characterization authenticated the presence of quercetin (1.44), gallic acid (0.23), caffeic acid (0.04), cinnamic acid (0.05), m-coumaric acid (0.23) and p-coumaric acid (0.37 μg/g) as the potent phenolics in Zympex-014 based extract. It can be concluded from the findings of the current work that pre-treatment of P. hermala leaves with Zympex-014 significantly enhanced the recovery of phenolics that supports its potential uses in the nutra-pharamaceutical industry.


2019 ◽  
Vol 09 ◽  
Author(s):  
Hossein Zaeri ◽  
Bahareh Kamyab Moghadas ◽  
Bijan Honarvar ◽  
Ali Shokuhi Rad

: In this research, the extraction of essential oil from Calotropis Procera with the family name of Asclepiadaceae, by supercritical carbon dioxide (CO2) solvent has been investigated in detail, and the yield and chemical profile of the extracts achieved by this method were compared with those resulted by the conventional Hydro distillation method. To optimize the process parameters of CO2 supercritical extraction (SCE) of the Calotropis Procera, the Response Surface Methodology (RSM) with central composite design (CCD) was employed. The effects of temperature, pressure, and extraction time on the oil yield are considered for investigation. Results showed that the data were sufficiently fitted into the second-order polynomial model. The extraction conditions, including pressure, temperature, and extraction time, were studied between 150-200 bar, 40-50 ºC, and 50-100 min, respectively. The optimal conditions are achieved as the temperature of 47.19ºC, the pressure of 172.2 bar, and time of 86 minutes with the retrieval rate of 31.39%.


2021 ◽  
Vol 13 (4) ◽  
pp. 2216
Author(s):  
Najeeha Mohd Apandi ◽  
Mimi Suliza Muhamad ◽  
Radin Maya Saphira Radin Mohamed ◽  
Norshuhaila Mohamed Sunar ◽  
Adel Al-Gheethi ◽  
...  

The present study aimed to optimize the production of Scenedesmus sp. biomass during the phycoremediation process. The biomass productivity was optimized using face centred central composite design (FCCCD) in response surface methodology (RSM) as a function of two independent variables that included wet market wastewater concentrations (A) with a range of 10% to 75% and aeration rate (B) with a range of 0.02 to 4.0 L/min. The results revealed that the highest biomass productivity (73 mg/L/d) and maximum growth rate (1.19 day−1) was achieved with the 64.26% of (A) and 3.08 L/min of (B). The GC-MS composition analysis of the biomass yield extract revealed that the major compounds are hexadecane (25%), glaucine (16.2%), and phytol (8.33%). The presence of these compounds suggests that WMW has the potential to be used as a production medium for Scenedesmus sp. Biomass, which has several applications in the pharmaceutical and chemical industry.


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