Optimization of Extraction Process of Clerodendrum philippinum Schauer var. simplex Mlodenke Total Flavonoids(CPTF) by Central Composite Design-Response Surface Methodology

[Objectives] The research aimed to optimize extraction process of Clerodendrum philippinum Schauer var. simplex Mlodenke total flavonoids( CPTF),and provide reference for its development and utilization. [Methods] Based on single-factor test,ethanol concentration,extraction temperature and extraction time were taken as independent variables,and total flavonoids yield was taken as dependent variable. The test was conducted according to central composite design principle. Multivariate linear regression and binomial equation fitting of the result were conducted,and extraction process of CPTF was optimized by using response surface methodology. [Results]The optimal extraction process of CPTF was as below: ethanol concentration 54. 76%,extraction temperature 83. 92℃,extraction time 102. 64 min,solid-liquid ratio 1:20,extraction for twice. [Conclusions] The extraction process of CPTF by central composite design-response surface methodology was simple and feasible,with reliable prediction result,which was suitable for industrial production.

Optimization of Extraction Process of Total Flavonoids from Akebia trifoliata (Thunb.) Koidz. by Central Composite Design-Response Surface Methodology

[Objectives]To optimize extraction process of total flavonoids from Akebia trifoliata( Thunb.) Koidz.,so as to provide references for development and use of Akebia trifoliata( Thunb.) Koidz. [Methods]The extraction rate of total flavonoids of Akebia trifoliata( Thunb.)Koidz. was taken as observation indicator. On the basis of single factor experiment,central composite design( CCD) was used to evaluate the effects of the extraction temperature,extraction time,and ethanol concentration on the extraction process. Multiple linear regression and binomial fitting were used,and response surface methodology( RSM) was used to select the optimum extraction process. [Results] The optimum extraction process conditions for total flavonoids of Akebia trifoliata( Thunb.) Koidz. was extraction temperature: 83. 92 ℃; extraction time:96. 47 min; ethanol concentration: 63. 92%; extraction times: two times; solid to liquid ratio: 1 ∶ 20; extraction rate of total flavonoids:4. 55%. [Conclusions] The central composite design-response surface methodology( CCD-RSM) is simple,convenient,and feasible for extraction of total flavonoids from Akebia trifoliata( Thunb.) Koidz.,and the prediction results are reliable.

Improvement of xylanase production by Aspergillus niger XY-1 using response surface methodology for optimizing the medium composition

Objective: To study the optimal medium composition for xylanase production by Aspergillus niger XY-1 in solid-state fermentation (SSF). Methods: Statistical methodology including the Plackett-Burman design (PBD) and the central composite design (CCD) was employed to investigate the individual crucial component of the medium that significantly affected the enzyme yield. Results: Firstly, NaNO3, yeast extract, urea, Na2CO3, MgSO4, peptone and (NH4)2SO4 were screened as the significant factors positively affecting the xylanase production by PBD. Secondly, by valuating the nitrogen sources effect, urea was proved to be the most effective and economic nitrogen source for xylanase production and used for further optimization. Finally, the CCD and response surface methodology (RSM) were applied to determine the optimal concentration of each sig-nificant variable, which included urea, Na2CO3 and MgSO4. Subsequently a second-order polynomial was determined by multiple regression analysis. The optimum values of the critical components for maximum xylanase production were obtained as follows: x1 (urea)=0.163 (41.63 g/L), x2 (Na2CO3)=?1.68 (2.64 g/L), x3 (MgSO4)=1.338 (10.68 g/L) and the predicted xylanase value was 14374.6 U/g dry substrate. Using the optimized condition, xylanase production by Aspergillus niger XY-1 after 48 h fermentation reached 14637 U/g dry substrate with wheat bran in the shake flask. Conclusion: By using PBD and CCD, we obtained the optimal composition for xylanase production by Aspergillus niger XY-1 in SSF, and the results of no additional expensive medium and shortened fermentation time for higher xylanase production show the potential for industrial utilization.

Optimization of the Impeller Geometry for an Automotive Torque Converter Using Response Surface Methodology and Desirability Function

Response surface methodology (RSM) based on desirability function approach (DFA) is applied to obtain an optimal design of the impeller geometry for an automotive torque converter. The relative importance of six design parameters including impeller blade number, blade thickness, bias angle, scroll angle, inlet angle and exit angle is investigated using orthogonal design approach. The impeller inlet angle, exit angle and bias angle are found to exert the greatest influence on the overall performance of a torque converter, with two flow area factors being considered, namely 17% and 20%. Then, RSM together with central composite design (CCD) method is used to in-depth evaluate the interaction effect of the three key parameters on converter performance. The results demonstrate that impeller exit angle has the strongest impact on peak efficiency, with larger angles yielding the most favorable results. The stall torque ratio maximization is attainable with the increase of impeller bias angle and inlet angle together with smaller exit angle. In the end, an optimized design for the impeller geometry is obtained with stall torque ratio and peak efficiency increased by 1.62% and 1.1%, respectively. The new optimization method can be used as a reference for performance enhancement in the design process of impeller geometry for an automotive torque converter.

Effect of Variable Selection on Multidisciplinary Design Optimization:a Flight Vehicle Example

Different multidisciplinary design optimization （MDO） problems are formulated and compared. Two MDO formulations are applied to a sounding rocket in order to optimize the performance of the rocket. In the MDO of the referred vehicle, three disciplines have been considered, which are trajectory, propulsion and aerodynamics. A special design structure matrix is developed to assist data exchange between disciplines. This design process uses response surface method （RSM） for multidisciplinary optimization of the rocket. The RSM is applied to the design in two categories： the propulsion model and the system level. In the propulsion model, RSM determines an approximate mathematical model of the engine output parameters as a function of design variables. In the system level, RSM fits a surface of objective function versus design variables. In the first MDO problem formulation, two design variables are selected to form propulsion discipline. In the second one, three new design variables from geometry are added and finally, an optimization method is applied to the response surface in the system level in order to find the best result. Application of the first developed multidisciplinary design optimization procedure increased accessible altitude （performance index） of the referred sounding rocket by twenty five percents and the second one twenty nine.

Improved elastase production by Bacillus sp. EL31410—further optimization and kinetics studies of culture medium for batch fermentation

An efficient culture medium producing a bacterial elastase with high yields was developed further following preliminary studies by means of response surface method. Central composite design (CCD) and response surface methodology were applied to optimize the medium constituents. A central composite design was used to explain the combined effect of three medium constituents, viz, glucose, K2HPO4, MgSO4·7H2O. The strain produced more elastase in the completely optimized medium, as compared with the partially optimized medium. The fitted model of the second model, as per RSM, showed that glucose was 7.4 g/100 ml, casein 1.13 g/100 ml, corn steep flour 0.616 g/100 ml, KEHPO4 0.206 g/100 ml and MgSO4·7H2O 0.034 g/100 ml. The fermentation kinetics of these two culture media in the flask experiments were analyzed. It was found that the highest elastase productivity occurred at 54 hours. Higher glucose concentration had inhibitory effect on elastase production. At the same time, we observed that the glucose consumption rate was slow in the completely optimized medium, which can explain the lag period of the highest elastase production. Some metal ions and surfactant additives also affected elastase production and cell growth.

骨伤跌打康复凝胶贴膏剂处方优选

目的优选骨伤跌打康复凝胶贴膏剂处方。方法以制剂的初黏力、持黏力、综合感官评分的归一化值为评价指标,以聚丙烯酸钠、甘羟铝、聚维酮K90、酒石酸、甘油、中药粉用量为影响因素,采用Plackett-Burman试验和星点设计-响应面法优选制剂处方,并验证。结果该凝胶贴膏剂制备工艺的关键因素为聚丙烯酸钠、甘羟铝、聚维酮K90的用量,最优处方配比为聚丙烯酸钠5.5 g、聚维酮K902.9 g、甘羟铝0.2 g。制得3批制剂的平均归一化值为0.8044,与理论值(0.817)接近(RSD为1.90%)。结论优化处方后的制剂外观均匀,黏性良好,符合凝胶贴膏剂的质量要求。

Media optimization for extracellular amylase production by Pseudomonas balearica vitps19 using response surface methodology

BACKGROUND： In this study, we optimized the process for enhancing amylase production from Pseudomonas balearica VITPS 19 isolated from agricultural lands in Kolathur, India. METHODS： Process optimization for enhancing amylase production from the isolate was carried out by Response Surface Methodology （RSM） with optimized chemical and physical sources using Design expert v.7.0. A central composite design was used to evaluate the interaction between parameters. Interaction between four factors - maltose （C-source）, malt extract （N- source）, pH, and CaCl2 was studied. RESULTS： The factors pH and CaCl2 concentration were found to affect amylase production. Validation of the experiment showed a nearly twofold increase in alpha amylase production. CONCLUSION： Amylase production was thus optimized and increased yield was achieved.

Pseudomonas sp.ZXY-1,a newly isolated and highly efficient atrazine-degrading bacterium,and optimization of biodegradation using response surface methodology

Atrazine, a widely used herbicide, is increasing the agricultural production effectively, while also causing great environmental concern. Efficient atrazine-degrading bacterium is necessary to removal atrazine rapidly to keep a safe environment. In the present study, a new atrazine-degrading strain ZXY-1, identified as Pseudomonas, was isolated. This new isolated strain has a strong ability to biodegrade atrazine with a high efficiency of 9.09 mg/L/hr.Temperature, p H, inoculum size and initial atrazine concentration were examined to further optimize the degradation of atrazine, and the synthetic effect of these factors were investigated by the response surface methodology. With a high quadratic polynomial mathematical model（R^2= 0.9821） being obtained, the highest biodegradation efficiency of 19.03 mg/L/hr was reached compared to previous reports under the optimal conditions（30.71°C, pH 7.14, 4.23%（V/V） inoculum size and 157.1 mg/L initial atrazine concentration）.Overall, this study provided an efficient bacterium and approach that could be potentially useful for the bioremediation of wastewater containing atrazine.

基于AHP-CRITIC混合加权法和星点设计-效应面法的荆防活血乳膏处方优化研究

目的研究并优选荆防活血乳膏剂的制备工艺。方法以荆防活血乳膏剂的离心稳定性、耐热稳定性、涂抹分散性为考察指标,采用层次分析法(AHP)、基于指标相关性的权重确定方法(CRITIC)、AHPCRITIC混合加权法确定各评价指标的权重系数,并结合星点设计(central composite design,CCD)-效应面优化法筛选荆防活血乳膏处方中出对基质质量影响较大的3个因素硬脂酸、甘油、混合乳化剂(平平加、三乙醇胺)的用量,验证优化后的最佳处方。结果按AHP-CRITIC混合加权法得到离心稳定性、耐热稳定性、涂抹分散性的权重系数分别为0.5216,0.3372,0.1412,最佳处方比例为:硬脂酸4.4 g,甘油14.3 g,混合乳化剂4.2 g,单硬脂酸甘油酯2 g,凡士林8.5 g,二甲基硅油10 g,纯化水20 g,冰片1.5 g(2%),苯甲酸钠0.1%,荆防活血方组方药物提取干膏用量7.5 g(每100 g乳膏中含主药量约10 g)。结论优选出的荆防活血乳膏剂制备工艺经验证简单、合理,所得制剂具有良好的外观性状、涂抹分散性和稳定性。

基于响应面法的抑尘剂组分配比优选模型

为解决抑尘剂多功能组分优选过程中存在的非线性问题,提出基于响应面法(RSM)的抑尘剂配比优化模型,在分析影响因素与响应值、各影响因素之间的交互作用特征的基础上,通过分析响应面的变化特征获得抑尘剂的最优配比。采用星点设计法,以润湿、保湿、黏结组分的体积分数为自变量,以粉尘沉降时间、失水率和风蚀率为因变量,在室内试验数据的基础上,开展多元线性方程拟合和方差分析,获得最优配比的预测结果,并进行试验验证。研究结果表明:星点设计—RSM模型的预测值与试验值偏差小于6.0%,优选组相比对照组(水)而言,粉尘沉降时间缩短23倍,失水率和风蚀率分别降低3.00%和2.64%,说明优选组具有优良的润湿、保湿和黏结性能,证明所构建的优化模型对抑尘剂多组分非线性优化问题具有良好的预测性能。

具有调节血糖功效的复合植物酵素的研究

该研究以红参、玉竹、马齿苋、枸杞、柚子、南瓜、生姜、芹菜、山药为原料制备酵素。通过单因素及星点设计-响应面试验确定酵素制备的最优条件,通过α-淀粉酶和α-葡萄糖苷酶抑制试验及大鼠试验探究酵素的血糖调节功能。结果表明,发酵时间为49.5 h,发酵温度为37℃,复合乳酸菌添加量为0.1%(质量分数)时效果最好,低聚果糖添加量对α-淀粉酶抑制率无显著影响(P>0.05)。酵素对α-淀粉酶和α-葡萄糖苷酶的IC_(50)值分别为(16.54±0.40)和(46.54±6.50)mL/L,酵素含量为33.3 mL/L时可完全抑制α-淀粉酶活性。大鼠试验表明酵素能明显改善糖尿病大鼠的空腹血糖。该研究确定了复合植物酵素的最优发酵工艺,通过抑制酶活性和降低大鼠空腹血糖确定酵素有调节血糖作用,为开发具有调节血糖功效的复合植物酵素提供理论依据。

Box-behnken响应面法优选肾风止痒方提取工艺研究

以没食子酸和盐酸小檗碱含量的综合评分为评价指标,在单因素实验基础上,采用Box-Behnken响应面法考察肾风止痒方最佳提取工艺。最佳提取工艺为:75%乙醇为溶媒,液料比12∶1(mL/g),常温浸泡96小时。验证试验综合评分95.02,与优选工艺相对误差为0.19%。本法简单,预测性良好,提取工艺稳定,为肾风止痒方的研究开发奠定基础。

响应面优化复方茶多酚口腔溃疡喷膜剂制备处方

目的:研制一款专治口腔溃疡的喷膜剂,并利用响应面法优化复方茶多酚口腔溃疡喷膜剂处方。方法:以聚乙烯醇(PVA)、嵌段式聚醚F-127(F-127)、聚氧乙烯月桂醚、甘油和乙醇的用量为自变量,以最终成膜效果为因变量,利用单因素实验对各自变量进行分析,选择影响较大的因素进行响应面法优化。同时以茶多酚、芦荟提取物、天冬提取物、金银花提取物的用量为自变量,以复方茶多酚口腔喷膜剂最终效果为因变量,采用响应面分析,得出复方茶多酚口腔溃疡喷膜剂的药材最佳处方。结果:复方茶多酚口腔溃疡喷膜剂的最优处方为PVA 4.00 g、F-127 2.00 g、聚氧乙烯月桂醚1.05 g、甘油3.90 mL、乙醇44.08 mL、茶多酚1.02 g、芦荟提取物1.02 g、天冬提取物1.06 g、金银花提取物1.03 g。结论:制得产品黏度适宜,成膜性能好,药物含量稳定,给药方便,可在口腔溃疡处持续给药,药物疗效较稳定。

响应曲面法在表面粗糙度预测模型及参数优化中的应用

分析了切削速度、进给量和切削深度对表面粗糙度的影响规律,提出了一种车削难加工材料钛合金TC11表面粗糙度的建模方法.采用中心组合设计方法,建立了用于表面粗糙度预测的多元回归模型,运用方差分析检验了该预测模型的拟合度,利用响应曲面法对表面粗糙度建立等值响应曲面,从而可以通过切削参数的优化在保证加工质量的前提下获得更高的材料去除率,实现难加工材料钛合金高效切削.

啤酒花多酚类化合物提取工艺的优化研究

从提取溶剂及提取条件等方面对啤酒花多酚提取工艺进行了优化研究。用单因子试验对提取溶剂进行了筛选,结果表明丙酮和水组成的复合体系是理想的提取溶剂。用析因试验对提取条件进行了分析研究,结果表明丙酮浓度、提取温度、提取时间、料液比都对啤酒花多酚提取产生一定的影响,其中丙酮浓度和提取温度的影响最为显著。通过最陡爬坡试验和中心组合设计试验,优化得到最佳的多酚类化合物提取条件为:丙酮浓度为62%,提取温度为47℃,在此条件下啤酒花中多酚的最大提取量为47.40mg·g-1。

β-甘露聚糖酶发酵液絮凝条件的统计学筛选与响应面优化

采用Plackett-Burman(PB)和中心复合设计(Central Composite Design)对影响地衣芽孢杆菌TJ-101发酵生产β-甘露聚糖酶粗发酵液絮凝操作的8个条件进行筛选优化。PB实验设计与统计学分析表明:加水量、阳离子聚丙烯酰胺(C-PAM)和阴离子聚丙烯酰胺(A-PAM)的体积分数是影响酶活收率的3个关键因素。以酶活收率为响应目标,对3因素进行中心复合设计,并经响应面法优化分析得到影响酶活收率的二阶模型,确定了β-甘露聚糖酶发酵液絮凝实验的最优操作条件为:加水量体积分数240.55%,C-PAM体积分数14.13%,A-PAM体积分数16.97%,絮凝后发酵液的酶活收率达70.42%。

基于响应面法的淤泥质土固化配方优化研究

选择掺入生石膏、生石灰、碳酸钠来消除有机质对水泥固化淤泥质土的不利影响。以生石膏、生石灰和碳酸钠的掺量作为3个影响因子,以固化淤泥质土7 d和90 d的无侧限抗压强度为响应值,采用旋转中心组合设计安排试验。利用响应面法对这3种外加剂的配比进行优化,并通过单因子效应分析和交互作用分析分别考察各影响因子单独变化对强度响应值的影响以及3种添加剂的交互作用效应。结果表明:强度响应对生石膏和生石灰掺量变化的敏感程度随龄期的增大而增大,而对于碳酸钠,情况则相反。7 d时,生石灰与碳酸钠的交互作用显著;而90 d时,则生石膏与碳酸钠的交互作用显著。最终得出在腐植酸掺量6%和水泥掺量15%前提下,3种外加剂在7 d和90 d的最佳配比。在最优配方的掺加下,对于7 d和90 d龄期固化淤泥质土的实际强度可以分别达到623、1 213 kPa。

基于响应面法的消防泵S型叶片改进优化设计

建立基于试验设计理论和响应面近似的S型叶片消防泵优化设计方法。定义最高效率、高效区范围及扬程在小流量区的稳定性为目标函数。以单级单吸离心泵MY56-50为初始模型,使用Bezier参数曲线拟合叶型曲面,得到叶片型线参数化模型。该方法以计算流体力学(Computational fluid dynamics,CFD)的计算结果为基础,对9个叶片型线控制参数,共进行39次试验,即先进行9次单因素试验设计筛选出对目标影响显著的叶片型线控制参数,再由中心复合设计(Central compositedesign,CCD)所得的30次试验及响应面分析确定筛选参数的最优设计点。根据结果构造S型叶片型线控制参数与多目标函数的响应面近似模型,分析参数间的交互效应。对最优设计点的泵进行试验研究,CFD计算值与响应面近似值吻合,且较MY56-50模型泵在性能上有很大提高,扬程的稳定性高,完全达到消防泵的工况标准,表明基于试验设计和响应面的优化设计方法可用于S型叶片消防泵的优化设计。