Small, balanced, efficient and near rotatable central composite designs

Angelopoulos, Panagiotis; Evangelaras, H.; Koukouvinos, Christos

doi:10.1016/j.jspi.2008.09.001

Cited by 26 publications

(17 citation statements)

References 12 publications

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“…where y(x i ) represents the response variable, x i is the independent variable (medium components), b o is the interception coefficient, b i the coefficient of the linear effect and e is the random error [23]. Afterwards a CC design 2 2?star with 2 center points was employed with glucose and MgSO 4Á 7H 2 O as study factors.…”

Section: Medium Optimizationmentioning

confidence: 99%

Effect of medium components and culture conditions in Bacillus subtilis EA-CB0575 spore production

Posada-Uribe

Romero-Tabarez

Villegas-Escobar

2015

Bioprocess Biosyst Eng

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Bacillus subtilis spores have important biotechnological applications; however, achieving both, high spore cell densities and sporulation efficiencies in fermentation, is poorly reported. In this study, medium components and culture conditions were optimized with different statistical methods to increase spore production of the plant growth promoting rhizobacteria B. subtilis EA-CB0575. Key medium components were determined with Plackett-Burman (PB) design, and the optimum concentration levels of two components (glucose, MgSO4·7H2O) were optimized with a full factorial and central composite design, achieving 1.37 × 10(9) CFU/mL of spore cell density and 93.5 % of sporulation efficiency in shake flask. The optimized medium was used to determine the effect of culture conditions on spore production at bioreactor level, finding that maintaining pH control did not affect significantly spore production, while the interaction of agitation and aeration rates had a significant effect on spore cell density. The overall optimization generated a 17.2-fold increase in spore cell density (8.78 × 10(9) CFU/mL) and 1.9-fold increase in sporulation efficiency (94.2 %) compared to that of PB design. These results indicate the potential of B. subtilis EA-CB0575 to produce both, high spore cell densities and sporulation efficiencies, with very low nutrient requirements and short incubation period which can represent savings of process production.

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Section: Medium Optimizationmentioning

confidence: 99%

Effect of medium components and culture conditions in Bacillus subtilis EA-CB0575 spore production

Posada-Uribe

Romero-Tabarez

Villegas-Escobar

2015

Bioprocess Biosyst Eng

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“…The CCD is the most accepted second-order regression model in the RSM, which was introduced by Box and Wilson in 1951 (Angelopoulos et al 2009). In a CCD, the No.…”

Section: Central Composite Designmentioning

confidence: 99%

Optimization of sample preparation method of total sulphur measurement in mine tailings

Khan

Shang

Alam

2013

Int. J. Environ. Sci. Technol.

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A sample preparation method of total sulphur measurement of reactive mine tailings was optimized. The total sulphur was measured by inductively coupled plasma optical emission spectroscopy, and ultrasound technique was used for sample digestion. The optimization process was adopted by a combined approach of experimental design and response surface methodology. The digestion time, temperature and acid-oxidant combination (i.e. effect of H 2 O 2 with a fixed amount of acid mixture) were investigated. A two-level and three-factor (2 3 ) full factorial design of experiment was applied to identify the most significant factors, and a central composite design was used to optimize the digestion procedure. KZK-1, a sericite schist, was selected as the certified reference material. The optimum methodology at 95 % confidence level (P \ 0.05) was identified to be 10 min of digestion at 77°C, with a solution of 1 ml HNO 3 :1 ml HCl:1.35 ml H 2 O 2 . This combination resulted in 100 % sulphur recovery. The investigated method was verified by X-ray diffraction analysis. The optimum digestion level was applied to a reactive mine tailings, which achieved satisfactory results with a percentage relative standard deviation \ 3 %.

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“…Downloaded by [University of Southern Queensland] at 20:11 09 October 2014 Designs in Table 4.1 are available at http://designcomputing.net/SCD/. The SCDs for k = 7, 8, and 9 of Draper and Lin (1990) have also been improved by Angelopoulos, Evangelaras and Koukouvinos (2009) using complete search. Complete search seems only feasible for seven or less factors.…”

Section: Designs For Sequential Experimentationmentioning

confidence: 99%

“…For more than seven factors, we have to resort to heuristic methods. Angelopoulos, Evangelaras and Koukouvinos (2009) have discussed the maximization of the rotatability index Q * (see Draper and Pukelsheim, 1990) by varying the α values in the axial runs.…”

Section: Designs For Sequential Experimentationmentioning

confidence: 99%

A Note on Small Composite Designs for Sequential Experimentation

Nguyen

Lin

2011

Journal of Statistical Theory and Practice

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The recommended approach to experiments using the response surface methodology is sequential, i.e., experiments should be conducted iteratively. At the first stage, a first-order design, usually an orthogonal two-level design (with a few center points) is used to find out whether the current region is appropriate and to allow the estimation of main effects (and possibly some interactions). The design at the first stage is then augmented with more runs in the second stage. The combined design allows the estimation of the remaining interaction and quadratic effects. Some well-known classes of designs which allow such a sequential experimentation are the central composite designs, the small composite designs and the augmented-pair designs. This paper reviews these designs and introduces a new algorithm which is able to augment any first order design with additional design points to form a good design for a second-order model.

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Small, balanced, efficient and near rotatable central composite designs

Cited by 26 publications

References 12 publications

Effect of medium components and culture conditions in Bacillus subtilis EA-CB0575 spore production

Effect of medium components and culture conditions in Bacillus subtilis EA-CB0575 spore production

Optimization of sample preparation method of total sulphur measurement in mine tailings

A Note on Small Composite Designs for Sequential Experimentation

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