4D printing of bio-composite tailored for NIR-light responsivity using liquid crystal display technique and its recovery modeling using central composite design

Central Composite experimental design applied to removal of lead and nickel from sand

The aim of this study was to apply central composite experimental design in the thia-Michael addition reaction between chalcone derivatives and mercaptans catalyzed by doped Fluorapatite catalyst (KF/FAP). Central composite design was used to create an experimental program to provide data to model the effects of various factors on reaction yield of thia-Michael addition (Y). The variables chosen were reaction time (X1), solvent volume (X2), catalyst weight (X3) and impregnation ratio (X4). The mathematical relationship between reaction yield and four significant independent variables can be approximated by a second-order quadratic model. Response surface methodology was used to describe the individual and interactive effects of four variables at five levels, combined according to a central composite design. This study has shown that central composite design can be applied to the catalytic carbon-sulfur bond formation in mild reaction condition with high yield, and it is an economical way of obtaining the maximum amount of information with the fewest experiments.

Hybrid designs were created to achieve the same degree of orthogonality as central composite or regular polyhedral designs, to be near-minimum-point, and to be near-rotatable. They resemble central composite designs which have been augmented with at extra variable column. Eight designs are presented covering 3, 4, and 6 variables. All of these are at or within one point of minimum. Characteristics relevant to choice of design are discussed. Efliciencies are compared to central composite or polyhedral designs on n-spheres. A 46 point 7 variable design is also presented which, although it is not near-minimum, is an economical alternative to a 79 point central composite design.

A central composite rotatable design (CCRD) methodology was used to analyze the effect of some operating variables on gas-liquid two phase mixing time in an agitated tank driven by dual 6-blade Rushton turbines. The variables chosen were the impellers rotational speed (x1), gas flow rate (x2), probe location (x3) and tracer injection point (x4). The mathematical relationship of mixing time on the four significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with the experimental values (R-sq of 95.9 percent and R-Sq (Adj) of 95.7 percent for response Y). This study has shown that central composite design could efficiently be applied for the modeling of mixing time, and it is an economical way of obtaining the maximum amount of information with the fewest number of experiments.

A central composite rotatable design (CCRD) methodology was used to analyze the effect of some operating variables on gas-liquid two phase mixing time in an agitated tank driven by dual 6-blade Rushton turbines. The variables chosen were the impellers rotational speed (x1), gas flow rate (x2), probe location (x3) and tracer injection point (x4). The mathematical relationship of mixing time on the four significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with the experimental values (R-sq of 95.9 percent and R-Sq (Adj) of 95.7 percent for response Y). This study has shown that central composite design could efficiently be applied for the modeling of mixing time, and it is an economical way of obtaining the maximum amount of information with the fewest number of experiments.

Hybrid designs were created to achieve the same degree of orthogonality as central composite or regular polyhedral designs, to be near-minimum-point, and to be near-rotatable. They resemble central composite designs which have been augmented with at extra variable column. Eight designs are presented covering 3, 4, and 6 variables. All of these are at or within one point of minimum. Characteristics relevant to choice of design are discussed. Efliciencies are compared to central composite or polyhedral designs on n-spheres. A 46 point 7 variable design is also presented which, although it is not near-minimum, is an economical alternative to a 79 point central composite design.

<a href="/public/journals/52/Dr.Tripathi.jpg"><strong><img src="/public/site/images/mmoslemi/Dr._Tripathi-S_.jpg" alt="" /></strong></a> <strong>Background and Objective:</strong> In the present study, Bacillus polymyxa NCIM No. 2539 was selected to utilize agro-industrial byproduct (orange peel) for amylase production under submerged<br />fermentation conditions.<br /><strong>Material and Methods:</strong> Different agro-industrial byproducts like cane molasses, wheat bran, rice bran and orange peel were screened for maximum amylase production. Amylase activitiy of Bacillus polymyxa was studied using starch-agar plate method. MINITAB software Version 17 and central composite design were applied to evaluate effect of supplementation of substrate with different sulphur containing amino acids (cysteine, methionine and cystine) and vitamin thiamine on enzyme activity. Further optimization of the parameters viz. amount of substrate, concentration of amino acid and vitamin for maximum amylase production was studied by central composite rotatable design.<br /><strong>Results and Conclusion:</strong> Among 4 different agro-industrial substrates applied, orange peel showed maximum enzyme production (activity: 492.31 IU g-1 sample). Supplementation of the production media with cysteine showed maximum amylase<br />production (515.38 IU g-1 sample) among all three amino acids and control. Supplementation with thiamine also showed more amylase production (469.23 IU g-1 sample) as compared to control (415.38 IU g-1). Cysteine and thiamine proved to increase<br />amylase production significantly. Maximum amylase production was obtained at 7.7 g orange peel, 37.29 mg cysteine and 34.23 mg per 10 ml thiamine.<br /><strong>Conflict of interest:</strong> The authors declare no conflict of interest.

The aim of this study was to apply experimental design in the optimization of the thia-Michael addition reaction between chalcone derivatives and mercaptans catalyzed by Fluorapatite catalyst (FAP). The central composite design was used to design an experimental program to provide data to model the effects of various factors on reaction yield (Y). The variables chosen were catalyst weight (X1), reaction time (X2) and solvent volume (X3). The mathematical relationship of reaction yield on the three significant independent variables can be approximated by a nonlinear polynomial model. Predicted values were found to be in good agreement with experimental values. The optimum reaction conditions (x1= 350 mg, x2= 30 min and x3= 2 mL) for reaction model (chalcone and thiophenol) obtained by response surface were applied to other substrates. This study has shown that central composite design could efficiently be applied for the modeling of catalytic carbon-sulfur bond formation by FAP catalyst under mild reaction condition with high yield, and it is an economical way of obtaining the maximum amount of information with the fewest number of experiments.

Optimization of β-carotene production from agro-industrial by-products by Serratia marcescens ATCC 27117 using Plackett–Burman design and central composite design

Response surface methods provide a powerful tool for constructing approximations to complex response functions. Statistical design of experiments is usually used to select optimal points that minimize the error in the resulting response surface approximation. Traditionally, data points are selected using minimum-variance designs, for example the D-optimal design, which may result in large bias errors for low-order approximation. Minimum-bias criteria have been developed for selecting data points to minimize the bias error of a response surface approximation. The present work developed a minimum-bias counterpart to the popular minimum-variance central composite designs. In addition, a new formulation of the minimum-bias design that assigns unequal weights to the design points, based on Gauss quadrature, is explored. Example problems are evaluated and the results obtained from D-optimal, the traditional minimum-bias, and the new Gauss-quadrature-based minimum-bias designs are compared. It is shown that the Gauss-quadrature-based minimum-bias design criterion results in the most accurate approximations and provides analytical solutions to a wider range of approximation domains than the traditional minimum-bias design. Response surface approximations based on minimum-bias central composite designs are more accurate than those constructed from traditional central composite design. Moreover, it is shown that using weights in regression has little influence on the accuracy of the response surface approximation in Gauss-quadrature minimum-bias designs.

The current aims to design and develop the optimized gel formulation containing the extracts of three leaf drugs Tamarindus indica, Nyctanthus arborstris, Memecylon malabaricum employing Carbopol 940 and HPMC as a gelling agent. The polyherbal gel formulations were optimized for desired viscosity and spreadability using central composite design by selecting the concentration of Carbopol 940 and HPMC as independent variables. A central composite design with two factors at three levels of different concentration of Carbopol 940 and HPMC K4M(1-1.5% and 1-2%), respectively, were used. Viscosity and spreadability were chosen as dependent variables. The pH and drug content were also determined for the prepared formulations. The in vitro drug release of optimized formulation through dialysis membrane was conducted for 8hrs using Franz diffusion cell apparatus to find out the amount of release of phenolic content during the period of study. Polyherbal gel formulation with Carbopol 940 and HPMC (1:1 w/w) was found to be the optimized formulation with desired viscosity and high spreadability of 3620cps and 18.61g cm/sec respectively, with required skin pH of and drug content of 97.05%. Invitrorelease of phenolic content was found to be more than 88.02±1.5% after 8hrs. Optimized poly herbal hydrogel formulation with high polyphenolic content is suitable for topical application. Further, this formulation has the potential to be used topically for disorders that require antioxidant therapy.

The most popular designs for fitting the second-order polynomial model are the central composite designs of Box and Wilson [2] and the designs of Box and Behnken [1]. For k = 2, 4, 6 and 8, the uniform shell designs of Doehlert [4] require fewer experimental runs than the central composite or Box-Behnken designs. In analytic chemistry the Doehlert designs are widely used. The uniform shell designs are based on a regular simplex, this is the geometric figure formed by k + 1 equally spaced points in a k -dimensional space; an equilateral triangle is a two-dimensional regular simplex. The shell designs are used for fitting a response surface to k independent factors over a spherical region. Doehlert (1930 - 1999) proposed in 1970 the design for k = 2 factors starting from an equilateral triangle with sides of length 1, to construct a regular hexagon with a centre point at (0, 0). The n = 7 experimental points are (1, 0), (0.5, 0.866), (0, 0), (-0.5, 0.866), (-1, 0), (-0.5, -0.866) and (0.5, -0.866).The 6 outer points lie on a circle with a radius 1 and centre (0, 0). This Doehlert design has an equally spaced distribution of points over the experimental region, a so-called uniform space filler, where the distances between neighboring experiments are equal. Response surface designs are usually applied by scaling the coded factor ranges to the ranges of the experimental factors. The first factor covers the interval [-1, + 1], the second factor covers the interval [-0.866, + 0.866]. Doehlert design for four factors needs only 21 trials. Doehlert and Klee [5] show how to rotate the uniform shell designs to minimize the number of levels of the factors. Most of the rotated uniform shell designs have no more than five levels of any factor; the central composite design has five levels of every factor. The D-Optimality determinant criterion of the variance matrix of Doehlert designs will be compared with central composite designs and Box-Behnken designs, see Rasch et al. [6].

Central composite experimental design applied to the catalytic aromatization of isophorone to 3,5-xylenol

醬油中香味成分之生成，一部份乃來自於醬醪的酵母菌發酵，為使能釀成具有特殊風味及香氣之醬油產品，近年的醬油釀造工業中，多採額外添加風味酵母菌進行發酵，而Zygosaccharomyces rouxii則是醬油釀造中，後期風味形成的重要菌株之一。本研究首先進行Z. rouxii BCRC 22499生長狀況瞭解，得知菌體對數生長期，並決定後續單因子試驗之取樣時間。透過單因子試驗，以菌體乾重為指標，研究碳源、氮源、pH值對Z. rouxii生長的影響。最終則以中心混成實驗設計，來獲得最適培養基組合。 實驗結果顯示Z. rouxii菌體的生長趨勢，於36小時進入對數生長期前段，故以此為取樣時間，進行發酵培養基組成優化實驗。單因子實驗中探討分別以碳源種類(葡萄糖、半乳糖、果糖、高果糖糖漿、麥芽糖、乳糖、砂糖)，碳源濃度(%,w/v)1、3、5、7、9，氮源種類(生醬油、尿素、蛋白腖、酵母抽出物、胰蛋白腖、casitone、硫酸銨、硝酸銨、氯化銨)，氮源濃度(%,v/v) 48、40、32、24、16、12、8、4，pH 值(4.0、4.5、5.0、5.5、6.0)對Z. rouxii生長的影響。單因子實驗結果顯示:以添加碳源高果糖糖漿（HFCS）3.0 (%,w/v)、氮源生醬油8.0 (%,v/v)、培養基質起始pH 5.0之條件為較佳。而中心混成設計結果顯示最適化培養條件為添加碳源HFCS 9.8 (%,w/v)、氮源生醬油8.42 (%,v/v)，實際培養獲得菌體乾重為0.0493 g/ml，與未最適化培養基相比較，其菌體乾重增加13倍。

In this study, application of the Response Surface Methodology and the Central Composite Design (CCD) technique for modeling and optimization the influence of some operating variables on gold and silver recovery in a cyanidation process were investigated. Three main cyanidation parameters, namely grinding time, sodium cyanide concentration, and alkalinity of solution, were changed during the concentration tests based on CCD. The range of values of the cyanidation process variables used in the design was as follows: grinding time, 32.61–44.39 min, sodium cyanide concentration, 1989–4511 ppm, and pH, 9.32–12.68. A total of 20 cyanidation tests were designed and carried out in the CCD method according to software-based designed matrix. According to the results, i.e., gold and silver recoveries with these three parameters, empirical model equations, were developed. Second-order equations of responses at the base of parameters were achieved by using statistical software. The model equations were then individually optimized by using quadratic programming to maximize both gold and silver recoveries within the experimental range. The optimum conditions were found to be 41.89 min for grinding time, 3665.28 ppm for cyanide concentration, and pH 9.32, for achieving the maximum gold recovery (96.23%). Similarly, the conditions for maximum silver recovery were 65.62% at 44.39 min for grinding time, 4511.34 ppm for cyanide concentration, and pH 12.68. The predicted values for gold and silver recoveries were found to be in a good agreement with the experimental values, with R 2 as correlation factor being 0.91 and 0.94, respectively.