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 method-ology 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, MgSO47H2O. 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, K2HPO4 0.206 g/100 ml and MgSO47H2O 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.

Interactive Optimization of Impressive Parameters Middling in Biological Leaching

In this study, single and interactive effect of three parameters, pH, ferrous and pulp concentration has been investigated by a 2^3 full factorial CCRD （central composite rotatable design） composed of eight factorial points, six central and six axial points. Initially, ＂none＂ mode from transformation subsection was chosen as the default choice for both responses, i.e. %recovery and gram of recovered zinc. Box-Cox plots give the best Lambda for each response （y^Lambda= f （A, B, C .....）） which occur at 1.91 and 2.16 for %recovey and gram of recovered zinc, respectively. A linear （y^1.91 = f （linear）） and a quadratic （y^2. 16= f （quadratic）） equation were suggested by software as the model for %recovery and gram of recovered zinc, respectively. Analysis of variance （ANOVA） for both models shows a high coefficient of determination （R^2）. In order to optimize and find the best conditions under which three parameters occur appropriately, optimization was done numerically. Desirability plots indicate properly that the best conditions occur at pH = 1.46, ferrous = 6.67 g/L, %pulp = 7.1 （%w/v）, %recovery = 86.5, gram of recovered zinc = 0.63 g and desirability = 0.777. Finally, PRP （progressive route of the process） analysis donates us a proper insight of what is happening during these 30 days. PRP analysis categorizes flasks in two parts, 1- flasks worth economically, 2- flasks with one-time-usable feed materials.

Optimization and characterization of nimesulide bilayer tablets by response surface methodology

The objectives of this present investigation were to develop and formulate nimesulide bilayer tablets by using different polymer combinations and fillers, to optimize the formulations for different drug release variables by orthogonal design and central composite design-surface methodology and to evaluate drug release pattern of the optimized product. The bilayer tablet containing a fast release layer（FRL） and a sustained release layer（SRL） provided an initial burst release of nimesulide, followed by the sustained release for a period of time. The optimal formulation obtained was as follows：（I） the formulation of FRL： nimesulide, 50 mg; lactose, 92 mg; starch, 22 mg; CCMC-Na, 14 mg; PVP K30, 1 mg; micronized silica gel, 1 mg; magnesium stearate, 0.9 mg; and iron oxide red, 0.1 mg; and（II） the formulation of SRL： nimesulide, 150 mg; HPMC K100LV, 26 mg; HPMC K4M, 33 mg; lactose, 54 mg; PVP K30, 1 mg; micronized silica gel, 1 mg; and magnesium stearate, 0.9 mg. According to the optimal formulation, the biphasic type of release was identified. The in vitro drug dissolution from the bilayer tablets was sustained for about 16 h after releasing 15% of drug in the first 10 min. The developed nimesulide bilayer tablets with improved efficacy can perform therapeutically better than the conventional tablets.

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。

基于温度场仿真的塑料感应焊接工艺参数优化

特种热塑性工程塑料的应用对高端制造领域的轻量化、高性能化和环保化起着极其重要的作用。为了研究塑料与金属的感应焊接过程,更好地理解该过程中不同工艺参数对焊接金属表面温度的影响,并探索最适合的塑料感应焊接工艺参数,利用有限元仿真软件ANSYS Maxwell进行电磁场模拟,采用中心复合设计方法完成塑料感应焊接工艺参数方案设计,再通过该有限元仿真软件求解出相应的金属表面温度。基于多元非线性理论,建立了电流强度、电流频率、焊接间隙与金属表面平均温度之间的多元非线性回归模型。采用逐步回归的迭代策略,分析了各工艺参数以及各工艺参数交互作用对金属表面平均温度的影响程度。结果表明:二次拟合模型具有最佳的拟合度,决定系数R^(2)=0.956;电流强度是对金属表面平均温度影响最大的主效应,电流强度与焊接间隙的交互作用是影响金属表面平均温度的主要交互效应;基于该二次拟合模型,在该有限元仿真软件上进行了工艺参数优化并预测了多组最佳工艺参数组合,其仿真试验结果与回归分析结果误差在7%以内,说明该二次拟合模型预测结果准确可靠。相关理论和方法可为塑料在汽车、船舶、航空、航天等高端制造领域的应用提供参考。

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.

Modelling and process optimisation of antimony removal from a complex copper concentrate

The modelling and optimization for the alkaline sulphide leaching of a complex copper concentrate containing 1.69% Sb and 0.14% Sn were studied.Response surface methodology,in combination with central composite face-centred design（RSM-CCF）,was used to optimise the operating parameters.The leaching temperature,sulphide ion concentration and solid concentration were chosen as the variables,and the response parameters were antimony and tin recovery,and the time required to achieve 90% Sb dissolution.It was confirmed that the leaching process was strongly dependent on the reaction temperature as well as the sulphide ion concentration without any significant dependence on the solid concentration.Furthermore,a mathematical model was constructed to characterise the leaching behaviour.The results from the model allow identification of the most favourable leaching conditions.The model was validated experimentally,and the results show that the model is reliable and accurate in predicting the leaching process.

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。