Optimization and Characterization of Cellulose Extraction from Grevillea robusta (Silky Oak) Leaves by Soda-Anthraquinone Pulping Using Response Surface Methodology

Response surface methodology (RSM) using the central composite design (CCD) was applied to examine the impact of soda-anthraquinone pulping conditions on Grevillea robusta fall leaves. The pulping factors studied were: NaOH charge 5% to 20% w/v, pulping time 30 to 180 minutes, and the anthraquinone charge 0.1 to 0.5% w/w based on the oven-dried leaves. The responses evaluated were the pulp yield, cellulose content, and the degree of delignification. Various regression models were used to evaluate the effects of varying the pulping conditions. The optimum conditions attained were;NaOH charge of 14.63%, 0.1% anthraquinone, and a pulping period of 154 minutes, corresponding to 20.68% pulp yield, 80.56% cellulose content, and 70.34% lignin removal. Analysis of variance (ANOVA), was used to determine the most important variables that improve the extraction process of cellulose. The experiment outcomes matched those predicted by the model (Predicted R2 = 0.9980, Adjusted R2 = 0.9994), demonstrating the adequacy of the model used. FTIR analysis confirmed the elimination of the non-cellulosic fiber constituents. The lignin and hemicellulose-related bands (around 1514 cm−1, 1604 cm−1, 1239 cm−1, and 1734 cm−1) decreased with chemical treatment, indicating effective cellulose extraction by the soda-anthraquinone method. Similar results were obtained by XRD, SEM and thermogravimetric analysis of the extracted cellulose. Therefore, Grevillea robusta fall leaves are suitable renewable, cost-effective, and environmentally friendly non-wood biomass for cellulose extraction.

Optimization of Preparation of Oregano Oil Microspheres by Box-Behnken Response Surface Methodology

[Objectives]To optimize the formulation and preparation of oregano oil microspheres by Box-Behnken response surface methodology.[Methods]Chitosan was used as the carrier material to prepare oregano oil microspheres by emulsion crosslinking method.The encapsulation efficiency,drug loading and ID 50 were used as the evaluation indicators,and the comprehensive score(OD)obtained by"coefficient of variation-AHP comprehensive weighting method"was used as the final evaluation indicator.The formulation design and preparation process were optimized by single factor experiment and Box-Behnken response surface methodology,and the optimal process parameters were determined.[Results]The optimal formulation and preparation process parameters of oregano oil microspheres were as follows:the ratio of oregano oil to chitosan was 2∶1,the emulsifying speed of double emulsion was 200 r/min,the amount of emulsifier in the colostrum was 4%,and the volume of curing agent was 1.0 mL.The average encapsulation efficiency was 45.33%±1.32%,the average drug loading was 30.59%±2.45%,and the median diameter(ID 50)was 52.596μm±0.023%.[Conclusions]The encapsulation efficiency,drug loading and ID 50 of oregano oil chitosan microspheres prepared by emulsion crosslinking method met the requirements.The drug-loaded microsphere not only can be used as a preparation finished product for direct application,but also be used as a product intermediate to lay a foundation for the research and development of subsequent dosage forms.

Optimization of Enzymatic Extraction Process of Polysaccharides from Pseudostellaria heterophylla Fibrous Roots by Response Surface Methodology and Its Pilot Application

[Objectives]To study and optimize the process conditions of enzymatic hydrolysis technology for extracting polysaccharides from Pseudostellaria heterophylla fibrous roots and its application in workshop pilot tests.[Methods]P.heterophylla fibrous roots were taken as the matrix material,and Box Behnken design was used to analyze the extraction time,composite enzyme addition amount,and liquid-solid ratio for response surface optimization experiments,and then applied to the pilot extraction of P.heterophylla fibrous roots.[Results]Response surface analysis showed that all factors had a significant impact on the experimental indicators.The optimal extraction process conditions for polysaccharides from P.heterophylla fibrous roots were extraction time of 2.7 h,compound enzyme addition of 2.5%,and liquid-solid ratio of 32.The yield of polysaccharides from P.heterophylla fibrous roots was 4.83%.The water extraction process of P.heterophylla fibrous roots extraction pilot was used as the control group for response surface optimization of the pilot experiment.The optimization results showed that the extraction time was 3 h,the amount of composite enzyme added was 2.5%,and the liquid-solid ratio was 28.The polysaccharide yield was 4.75%,an increase of 4.63%compared to the control group.[Conclusions]This paper could provide feasibility for the innovation of enzy-matic hydrolysis technology for P.heterophylla fibrous roots and its workshop pilot practice application,as well as a reference for the industrial application of its medicinal resources.

Optimization of Methylene Blue Dye Adsorption onto Coconut Husk Cellulose Using Response Surface Methodology: Adsorption Kinetics, Isotherms and Reusability Studies

In this study, coconut husk cellulose was employed as a cost-effective and environmentally friendly adsorbent to eliminate methylene blue (MB) dye from aqueous solutions. The successful development of response surface methodology paired with a central composite design (RSM-CCD) enabled the optimization and modelling of the adsorption process. The study investigated the individual and combined effects of three variables (pH, contact time, and initial MB dye concentration) on the adsorption of MB dye onto coconut husk cellulose. The developed RSM-CCD model exhibited a remarkable degree of precision in predicting the removal efficiency of MB dye within the specified experimental parameters. This was demonstrated by the strong regression parameters, with an R2 value of 99.79% and an adjusted R2 value of 99.6%. The study depicted that the optimal parameters for attaining a 98.8827% removal of MB dye using coconut husk cellulose were as follows: an initial MB dye concentration of 30 mg∙L−1, contact time of 120 minutes, and pH 7 at a fixed adsorbent dose of 0.5 g. The Freundlich isotherm model provided the most satisfactory description of the equilibrium adsorption isotherms, suggesting that MB dye adsorption onto coconut husk cellulose occurs on a heterogeneous surface. The experimental results demonstrated a strong agreement with the pseudo-second-order kinetics model, indicating that the number of active sites present on the cellulose adsorbent predominantly influences the adsorption process of MB dye. Additionally, the adsorbent made from coconut husk cellulose exhibited the potential to be reused, as it retained its efficiency for a maximum of three cycles of adsorption of MB dye. The results of this study show that coconut husk cellulose has the potential to be an effective and sustainable adsorbent for removing MB dye from aqueous solutions.

Optimization of Cellulose Nanocrystal Isolation from Ayous Sawdust Using Response Surface Methodology

This study focuses on the extraction of cellulose nanocrystals (CNC), from microcrystalline cellulose (MCC), derived from Ayous sawdust. The process involves multiple steps and a large amount of chemical products. The objective of this research was to determine the effects of factors that impact the isolation process and to identify the optimal conditions for CNC isolation by using the response surface methodology. The factors that varied during the process were the quantity of MCC, the concentration of sulfuric acid, the hydrolysis time and temperature, and the ultrasonic treatment time. The response measured was the yield. The study found that with 5.80 g of microcrystalline cellulose, a sulfuric acid concentration of 63.50% (w/w), a hydrolysis time of 53 minutes, a hydrolysis temperature of 69˚C, and a sonication time of 19 minutes are the ideal conditions for isolation. The experimental yield achieved was (37.84 ± 0.99) %. The main factors influencing the process were the sulfuric acid concentration, hydrolysis time and temperature, with a significant influence (p < 0.05). Infrared characterization results showed that nanocrystals were indeed isolated. With a crystallinity of 35.23 and 79.74, respectively, for Ayous wood fiber and nanocrystalline cellulose were observed by X-ray diffraction, with the formation of type II cellulose, thermodynamically more stable than native cellulose type I.

INTEGRATION SHAPE AND SIZING OPTIMIZATION OF COMPOSITE WING STRUCTURE BASED ON RESPONSE SURFACE METHOD

An effective optimization method for the shape/sizing design of composite wing structures is presented with satisfying weight-cutting results. After decoupling, a kind of two-layer cycled optimization strategy suitable for these integrated shape/sizing optimization is obtained. The uniform design method is used to provide sample points, and approximation models for shape design variables. And the results of sizing optimization are construct- ed with the quadratic response surface method （QRSM）. The complex method based on QRSM is used to opti- mize the shape design variables and the criteria method is adopted to optimize the sizing design variables. Compared with the conventional method, the proposed algorithm is more effective and feasible for solving complex composite optimization problems and has good efficiency in weight cutting.

Response surface optimization of process parameters for reduction roasting of low-grade pyrolusite by bagasse

The reduction roasting processes for low-grade pyrolusite using bagasse as the reducing agent was statistically analyzed. The central composite rotatable design （CCD） was used to optimize this reduction roasting processes. The three process parameters studied were the mass ratio of bagasse to ore, the roasting temperature and the roasting time. Analysis of variance （ANOVA） was used to analyze the experimental results. The interactions between the process parameters were done by using the linear and quadratic model. The results revealed that the linear and quadratic effects as well as the interaction are statistically significant for the mass ratio and roasting temperature but insignificant for the roasting time. The optimal conditions of 0.9：10 of mass ratio, the roasting temperature of 450 ~C, the roasting time of 30 min were obtained. Under these conditions, the predicted leaching recovery rate for manganese was 98.1%. And the satisfied experimental result of 98.2% confirmed the validity of the model.

Optimization of preparing V_2O_5 by calcination from ammonium metavanadate using response surface methodology

Parameters of technique to prepare vanadium pentoxide by calcination from ammonium metavanadate were optimized using central composite design of response surface methodology. A quadratic equation model for decomposition rate was built and effects of main factors and their corresponding relationships were obtained. The results of the statistical analysis show that the decomposition rate of ammonium metavanadate is significantly affected by calcination temperature and calcination time. The optimized calcination conditions are as follows： calcination temperature 669.71 K, calcination time 35.9 min and sample mass 4.25 g. The decomposition rate of ammonium metavanadate is 99.71%,which coincides well with experimental value of 99.27% under the optimized conditions, suggesting that regressive equation fits the decomposition rates perfectly. XRD reveals that it is feasible to prepare the V2O5 by calcination from ammonium metavanadate using response surface methodology.

Response surface optimization of process parameters for removal of F and Cl from zinc oxide fume by microwave roasting

Microwave was applied to roasting the zinc oxide fume obtained from fuming furnace for the removal of F and Cl. The effects of important parameters, such as roasting temperature, holding time and stirring speed, were investigated and the process conditions were optimized using response surface methodology (RSM). The results show that the effects of roasting temperature and holding time on the removal rate of F and Cl are the most significant, and the effect of stirring speed is the second. The defluorination rate reaches 92.6% while the dechlorination rate reaches 90.2%, under the process conditions of roasting temperature of 700 °C, holding time of 80 min and stirring speed of 120 r/min. The results indicate that the removal of F and Cl from fuming furnace production of zinc oxide fumes using microwave roasting process is feasible and reliable.

Optimization of Supercritical Carbon dioxide Extraction of Ginger Essential Oil by Response Surface Method

[Objective] Ginger essential oil （GEO） is widely used in food production and medical field in recent years due to its prominent biological functions, and this study was conducted to obtain high-quality and high-purity ginger essential oil from the fresh ginger. [Method] GEO was extracted from ginger roots by supercritical fluid extraction （SFE） method. The effects of flow rate of CO2, mesh size of ginger powder and volume of entrainer were investigated by single-factor experiments and response surface method. The content and extraction rate of 6-gingerol represented the extraction index of GEO. [Result] The conditions were optimized as follows： flow rate of CO2 at 25 L/h, mesh size of ginger power of 80 mesh, and volume of anhydrous ethanol as entrainer of 92.46 ml. The optimal extraction rate of 6-gingerol was 3.21%, which was predicted by RSM. [Conclusion] The optimal process of supercritical carbon dioxide extraction of ginger essential oil was identified by singlefactor experiments and response surface method. The present study provides a satisfactory method for purifying GEO from ginger for industrial purpose.

SCRAMJET INLET MULTI-OBJECTIVE OPTIMIZATION BASED ON RESPONSE SURFACE METHODOLOGY

The uniform design and response surface methodology （RSM） are applied to the multi-objective optimization of a 2-D mixed compression scramjet inlet. The set of experimental design points on the design space is selected by the uniform design, and the inlet performance is analyzed by computational fluid dynamics （CFD）. Then complete quadratic polynomial response surface approximation models are constructed based on the performance analysis results and then used to replace theoriginal complex inlet performance model. The optimization is conducted using a multi-objective genetic algorithm NSGA-Ⅱ, and the Pareto optimal solution set is obtained. Results show that the uniform design and RSM can reduce the computational complexity of numerical simulation and improve the optimization efficiency.

Optimization of the biphasic release of indomethacin from HPMC/pectin/calcium chloride matrix tablet by response surface methodology

We studied the effect of two independent variables, the pectin/calcium chloride weight ratio and the overall matrix weight in HPMC/pectin/calcium matrix tablet, on the release of indomethacin. A two-factor 5-level central composite experimental design was employed. Responses of the Peppas correlation parameters n and K and the 10% release time （T0.1） were optimized by response surface methodology. Significant effect of the independent variables on the biphasic release parameters, n and K, was observed. N, K and T0.1 were well fitted with the second-order quadratic equations rather than linear equations. Moreover, the mathematic fitting and the response surfaces showed significant cross-interaction between the pectin/calcium chloride ratio and the overall matrix weight. The optimal formulation with larger n, longer T0.1 and smaller K consisted of medium pectin/calcium chloride ratio around 1.0 and medium matrix weight around 200 mg. Validation studies on the optimal formulations showed good predictability of the n, K and T0.1 values with biases within the range of-7.33% and 6.26%. Our results support that central composite design can be used to optimize drug release from HPMC/pectin/calcium matrix tablet with high predictability.

Optimization of the Fermentation Conditions of Sweet Oats by Response Surface Methodology

Objective] The purpose of this study was to evaluate the effects of five variables （steaming time, moisture content before inoculation, inoculation amount, fer-mentation temperature, fermentation time） on the sweetness of sweet oats, obtained the best fermentation conditions. [Method] Plackett-Burman （PB） was to evaluate the effects of five variables, and selected significant factors. The steepest ascent was used to approach the optimal response surface experimental area. The optimal fer-mentation condition was obtained by central composite design and response surface analysis. [Results] It was indicated that moisture content, inoculation amount and fer-mentation temperature had significant influences on the content of the reducing sugars. The optimal conditions of moisture content, inoculation amount and temper-ature were 45.26%, 0.014%（g/g） and 28 ℃, respectively. The predicted value of the reducing sugar content was 13.16 mg/g. [Conclusion] Under the optimal conditions, the content of the reducing sugars in the sweet oats could be up to 12.91 mg/g, which was on the whole consistent with the predictive maximum value.

Optimization of Microwave Extraction of Flavonoids from Water Chestnut Skin Dregs with Response Surface Method

[Objective] In order to take full advantage of processing by-product of water chestnut, the microwave extraction method of flavonoids from water chestnut skin dregs was optimized. The extracted flavonoids had a relatively high yield. [Method] The Box-Behnken design-based response surface method was adopted to optimize the microwave extraction of flavonoids from water chestnut skin dregs, a by-product of water chestnut starch. The mathematical relationships between various influencing factors and flavonoids yield were established. [Result] The optimum extraction conditions of flavonoids from water chestnut skin dregs were as follows： ethanol concentration of 55.4%, solid/liquid ratio of 1：30 g/ml, microwave power of 320 W, microwave time of 3 min and microwave time of 2 times. Under the optimum extraction conditions, the theoretical flavonoids yield was 2.376%. However, the actual flavonoids yield under the optimum extraction conditions was 2.365%. The relative error between actual values and theoretically predicted values was 0.461%. [Conclusion] The results showed the optimized extraction method is reliable, and it can provide a reference for the comprehensive and highly efficient utilization of water chestnut processing wastes.

Cooperative User-Scheduling and Resource Allocation Optimization for Intelligent Reflecting Surface Enhanced LEO Satellite Communication

Lower Earth Orbit(LEO) satellite becomes an important part of complementing terrestrial communication due to its lower orbital altitude and smaller propagation delay than Geostationary satellite. However, the LEO satellite communication system cannot meet the requirements of users when the satellite-terrestrial link is blocked by obstacles. To solve this problem, we introduce Intelligent reflect surface(IRS) for improving the achievable rate of terrestrial users in LEO satellite communication. We investigated joint IRS scheduling, user scheduling, power and bandwidth allocation(JIRPB) optimization algorithm for improving LEO satellite system throughput.The optimization problem of joint user scheduling and resource allocation is formulated as a non-convex optimization problem. To cope with this problem, the nonconvex optimization problem is divided into resource allocation optimization sub-problem and scheduling optimization sub-problem firstly. Second, we optimize the resource allocation sub-problem via alternating direction multiplier method(ADMM) and scheduling sub-problem via Lagrangian dual method repeatedly.Third, we prove that the proposed resource allocation algorithm based ADMM approaches sublinear convergence theoretically. Finally, we demonstrate that the proposed JIRPB optimization algorithm improves the LEO satellite communication system throughput.

Composite Structural Optimization by Genetic Algorithm and Neural Network Response Surface Modeling

Neural-Network Response Surfaces （NNRS） is applied to replace the actual expensive finite element analysis during the composite structural optimization process. The Orthotropic Experiment Method （OEM） is used to select the most appropriate design samples for network training. The trained response surfaces can either be objective function or constraint conditions. Together with other conven- tional constraints, an optimization model is then set up and can be solved by Genetic Algorithm （GA）. This allows the separation between design analysis modeling and optimization searching. Through an example of a hat-stiffened composite plate design, the weight response surface is constructed to be objective function, and strength and buckling response surfaces as constraints; and all of them are trained through NASTRAN finite element analysis. The results of optimization study illustrate that the cycles of structural analysis ean be remarkably reduced or even eliminated during the optimization, thus greatly raising the efficiency of optimization process. It also observed that NNRS approximation can achieve equal or even better accuracy than conventional functional response surfaces.

Optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum, using response surface methodology

The optimization of process parameters for the bioconversion of activated sludge by Penicillium corylophilum was investigated using response surface methodology （RSM）. The three parameters namely temperature of 33℃, agitation of 150 r/min, and pH of 5 were chosen as center point from the previous study of fungal treatment. The experimental data on chemical oxygen demand （COD） removal （%） were fitted into a quadratic polynomial model using multiple regression analysis. The optimum process conditions were determined by analyzing response surface three-dimensional surface plot and contour plot and by solving the regression model equation with Design Expert software. Box-Behnken design technique under RSM was used to optimize their interactions, which showed that an incubation temperature of 32.5℃, agitation of 105 r/min, and pH of 5.5 were the best conditions. Under these conditions, the maximum predicted yield of COD removal was 98.43%. These optimum conditions were used to evaluate the trail experiment, and the maximum yield of COD removal was recorded as 98.5%.

SIX SIGMA OPTIMIZATION IN SHEET METAL FORMING BASED ON DUAL RESPONSE SURFACE MODEL

Iterations in optimization and numerical simulation for the sheet metal forming process may lead to extensive computation. In addition, uncertainties in materials or processing parameters may have great influence on the design quality. A six sigma optimization method is proposed, by combining the dual response surface method （DRSM） and six sigma philosophy, to save computation cost and improve reliability and robustness of parts. Using this method, statistical technology, including the design of experiment and analysis of variance, approximate model and six sigma philosophy are integrated together to achieve improved quality. Two sheet metal forming processes are provided as examples to illustrate the proposed method.

Optimization of Steam Explosion Process Condition for Extracting Polysaccharides from Pseudostellaria heterophylla by Response Surface Methodology

【Objective】To optimize the steam explosion process condition for extracting polysaccharides from Pseudostellaria heterophylla.【Method】The effects of steam pressure,pressure-maintaining time and material moisture content on the extraction of polysaccharides from Pseudostellaria heterophylla were studied by response surface methodology based on Box-Behnken design.【Result】The findings showed that each factor could significantly affect the test index,and the optimum condition was as follows:steam pressure 1.50 Mpa,pressuremaintaining time 46 s and material moisture content 46%.Under this condition,the verified experimental value of polysaccharides from Pseudostellaria heterophylla was 39.32%,indicating a relative standard deviation of 2.73%from the predictive value.Meanwhile,scanning electron microcopy(SEM)images showed that the surface physical structure of Pseudostellaria heterophylla was irregularly broken and cracked,which means the physical structure of Pseudostellaria heterophylla was changed and destroyed at the cellular level.【Conclusion】This experiment provides a new approach for the extraction of polysaccharides from Pseudostellaria heterophylla,as well as a reference for the resource utilization of Pseudostellaria heterophylla.

Optimization of Formula of Matsutake Highland Barley Biscuit by Response Surface Methodology

Taking refined flour,matsutake powder,and highland barley powder as main raw materials,this experiment studied the optimal formula of matsutake highland barley biscuit. Besides,single factor experiment was carried out for the amount of highland barley powder,white granulated sugar,and shortening. Then,the response surface optimization analysis was made on crispness and sensory score of the biscuit. The experiment indicates that taking the refined flour as the base 100 g( 100%),the formula of 20% highland barley powder,25% white granulated sugar,and 26% shortening can bake crisp biscuit with complete shape,pure flavor and high quality.