Stepwise multiple regressions application in liposome orthogonal experiments

Aim New statistical method was applied in data analysis of orthogonal experiments to optimize the preparation of liposome. Method Particle size, zeta potential, encapsulation efficiency and physical stability of liposomes were selected by orthogonal design as evaluating indicators. Through three statistical methods （direct observation, variance analysis and stepwise multiple regression）, the optimized preparing conditions were acquired and validated by experiment. Results All of the four indicators were different by these analyses. The validation experiments indicated that the optimized conditions by stepwise multiple regressions were better than that by traditional analysis. Conclusion Experiment results suggested that multiple regressions could avoid the weakness of direct observation and variance analysis, but more work should be done in preparing liposomes.

Treatment performance of integrated biological aerated filter by orthogonal experiments

Biological aerated filters have many advantages such as small volume and high treatment efficiency. This research focused on sewage treatment performance of integrated biological aerated filter (IBAF) under different conditions such as aeration, hydraulic retention time and the height of fillers layer, to identify the turn of marked affecting factor of removal performance through orthogonal experiments, optimize the function parameter of IBAF, reveal the regularity of sewage treatment of IBAF under different conditions, and adopt suitable measures to guarantee excess water quality of IBAF.

Orthogonal Experiments for Controlling the Formation of DBPs During Preozonation of Bromide-Containing Raw Water

Orthogonal method was adopted to optimize the preozonation process and to minimize the bromate formation. Factors such as contact time, pH and ammonia concentration were investigated by orthogonal experiments to understand the interaction of various operation conditions on the formation of bromate and other disinfection byproducts(DBPs). Results showed that pH had the most significant influence on the minimization of bromate formation. The factors influencing the formation of bromate were in order of pH > contact time > ammonia concentration. For the formation of trihalomethanes(THMs) and haloacetic acids(HAAs), however, contact time significantly influenced their formation potential. In the practical preozonation process of waterworks, it is appropriate to set preozonation contact time to be 20 min. In order to minimize the formation of bromate, pH value of the raw water should be adjusted to 6. 0, and a certain concentration of ammonia could be added into the water to strengthen the minimization effect when the concentration of bromide in the raw water is higher than that in the experimental water.

Global optimization of process parameters for low-temperature SiN_(x) based on orthogonal experiments

Low-temperature silicon nitride(SiNx)films deposited by plasma-enhanced chemical vapor deposition(PECVD)have huge application potential in the flexible display.However,the applicability of SiNx largely depends on the film’s general properties,including flexibility,deposition rate,residual stress,elastic modulus,fracture strain,dielectric constant,refraction index,etc.Process optimization towards specific application by conventional experiment design needs lots of work due to the interaction of muti quality and process parameters.Therefore,an efficient global optimization approach for the process technology was proposed based on the Taguchi orthogonal experiment method considering muti-factor muti-responses.First of all,the Taguchi orthogonal experiment design and analysis was used to rank the influences of main process parameters on the quality characteristics,including radio frequency(RF)power,pressure,silane flow rate,ammonia flow rate and nitrogen flow rate.Then,the global optimization approach was carried out utilizing the multi-response optimizer considering the combination target of film formation rate,residual stress,dielectric constant,elastic modulus,fracture strain,refractive index.Finally,the optimal solution of the SiNx film was finally obtained and verified.

Application of fuzzy analytical method in the optimization of liposome preparation by orthogonal experiments

A new statistical method, the fuzzy analytical method, was introduced in the optimization processes of liposome preparation. It took the full advantage of the information from orthogonal experiments to obtain the optimal liposome preparation conditions by considering all the evaluation indexes. Liposomes were made by the modified reverse-phase evaporation method and the properties of liposomes including size, encapsulation efficiency and physical stability were selected as the evaluation indexes to indicate the quality of liposomes. The experimental data of these properties were analyzed by three different methods including direct observation, variance analysis and fuzzy analytical method. The optimal preparation conditions obtained from these methods were validated with further experiments. The results of all possible combinations of levels for all factors in orthogonal experiments were acquired by the fuzzy analytical method. All evaluation indexes were taken into account and the optimal preparation condition was obtained. The optimal preparation conditions from direct observation and fuzzy analytical method were different and further validation studies indicated that the optimal conditions obtained from the fuzzy analytical method were in agreement with that from traditional statistical analysis. Fuzzy analytical method avoided the problem resulted from the traditional method, in which different levels of the same factor were obtained when considering different evaluation indexes. More information could be obtained from the fuzzy analytical method and the blind area within the experimental range was eliminated. As a result, fuzzy analytical method can be applied in the optimization processes of liposome preparation.

Orthogonal Experiments on Direct Reduction of Carbon-bearing Pellets of Bayer Red Mud

To recycle residual iron efficiently in Bayer red mud, three-factor three-level orthogonal experiments on carbon-bearing pellets of Bayer red mud were conducted on the basis of their characteristics. The influences of CaO dosage, temperature and roast- ing time on total iron content and iron recovery of reduced iron powder were studied. Results showed that these factors slightly influenced iron recovery, but significantly influenced total iron content. The principal factor influencing total iron content was CaO dosage, followed by temperature and roasting time. An increase in CaO dosage could decrease total iron content, whereas an increase in temperature and an extension of roasting time could improve total iron content. The reduced iron powder with total iron content of 88.4 l% and iron recovery rate of 97.97% can be obtained under the optimal conditions of temperature of 1 275 ℃, roasting time of 60 min and CaO dosage of 7.5%. The X-ray diffraction （XRD） and scanning electron microscopy （SEM） analyses of the reduced pellets showed that iron minerals in red mud were almost completely reduced to metallic iron. The principal factor influencing the total iron content of reduced iron powder was the grain size of metallic iron particles. An increase in CaO dosage hindered the growth of metallic iron particles, whereas an increase in temperature and an extension of roasting time could neutralise the effect of CaO dosage. Therefore, CaO dosage should be decreased when iron minerals in red mud can be adequately reduced into metallic iron.

Optimization of extraction of polyphenols from pomegranate peel by orthogonal experiment design and antioxidant activity

The aim of this study was to investigate the extraction process and antioxidant activity of polyphenols from Yunnan Mengzi pomegranate peel.Single factor and orthogonal test were used as optimize the extract rate(ER)of polyphenols from pomegranate peel(PGP).The polyphenols antioxidant activity was evaluated by DPPH·,·OH and total reducing ability,and compared with that of Vc.The optimum extraction conditions of polyphenols were as follows:ethanol concentration of 50%,liquid-solid ratio of 50:1,extraction temperature of 90°C,extraction for 4 h.Under these conditions,the ER of polyphenols from GPG was 8.15%.The results showed that the scavenging effects of polyphenols and Vc on DPPH·,·OH increased with increasing concentration,and the scavenging effect of polyphenols on DPPH·was higher than Vc in rang of 0.1-1.6µg/mL.When the concentration is greater than 0.6µg/mL,the scavenging effects of plyphenols on·OH is higher than Vc.The total reducing ability of polyphenols from PGP improved with the increase of concentration,and when the concentration was 8µg/mL,the total reducing ability was 114 U/mL.

Optimization of Extraction Process for Total Flavonoids from Penthorum chinense Pursh and Comparison of Their Contents from Different Parts

[Objectives]This study was conducted to optimize the extraction process of total flavonoids from Penthorum chinense Pursh and compare their contents from different parts.[Methods]Single factor and orthogonal experiments were designed to optimize the extraction process of total flavonoids from P.chinense Pursh with the volume fraction of ethanol,the ratio of material to liquid,heating reflux extraction time and extraction times as factors,and the content of total flavonoids as the index.A verification test was carried out.The optimized extraction process was adopted to compare the contents of total flavonoids from different parts of P.chinense Pursh.[Results]The best extraction process was extracting the powder of P.chinense Pursh for 2.0 h with 20 times of 55%ethanol by reflux twice.Under this condition,the contents of total flavonoids were 3.63%,8.90%,11.28%,and 4.36%from stems,leaves,flowers and whole grass of P.chinense Pursh,respectively.[Conclusions]The process is reasonable,feasible and stable,and can effectively extract total flavonoids from P.chinense Pursh.The contents of total flavonoids from different parts of P.chinense Pursh were quite different,and the value was higher in the leaves and flowers,so the proportions of leaves and flowers should be paid attention to in the industrial processing of P.chinense Pursh.

Study on Extraction of Oolong Tea Assisted by Ultrasonic Wave and 4C Technique and Its Application

[Objectives]The extraction conditions of formula oolong tea were investigated by an orthogonal experiment.[Methods]The technical conditions were optimized by the 4C method,and the application of formula oolong tea extract in cigarettes was studied.[Results]①In the experimental range,the best sensory evaluation effect of formula oolong tea extract was obtained with extraction conditions of 70%ethanol as extraction solvent,extraction time h,extraction temperature 25℃,and ultrasonic frequency 80 kHz,and follow-up low-temperature concentration,low-temperature sedimentation and low-temperature centrifugation.②The effects of different centrifugal speeds on the quality of formula oolong tea extract were explored.The formula oolong tea extract obtained under the conditions of 3000 r/min and centrifugal time of 10 min showed the best evaluation effect with soft and delicate smoke,rich smoke fragrance,good comfort and refreshing mouthfeel.③The effective aroma components in the formula oolong tea extract were qualitatively analyzed by GC-MS.[Conclusions]This study provides high-quality raw materials and a theoretical basis for the research of independent flavor blending in cigarette industry enterprises.

An Orthogonal Experiment of Papain-Assisted Extraction of Polysaccharides from Agrocybe aegirit

[Objective] This study aimed to explore optimum conditions for papain-as- sisted extraction of polysaccharides from Agrocybe aegirit. [Method] Because enzyme is capable of destroying organizational structure of cells, papain was selected to cat- alyze cells to let polysaccharides out. An orthogonal experiment was carried out to investigate the effects of hydrolysis temperature, hydrolysis time, enzyme concentra- tion and solid to liquid ratio on extraction of polysaccharides from A. aegirit. [Result] Through the orthogonal experiment, the optimum papain-assisted extraction conditions were obtained： hydrolysis temperature, 45 ℃; hydrolysis time, 2 h; enzyme concen- tration 2%; solid to liquid ratio, 1：80. [Conclusion] This study will provide a reference for extraction of polysaccharides from A. aegirit.

Orthogonal Test Design for Optimization of the Extraction of Flavonid from the Fructus Gardeniae

Objective It is imperative to provide some consistent experimental results for the extraction of flavonid from Fructus Gardeniae. Methods The key extraction parameters that influenced the yield of flavonid from Fructus Gardeniae were optimized by employing an orthogonal experiment [L9（3）4], including the ratio of buffer solution （Na2B4O7· 10H2O） to raw material, concentration of Fructus Gardeniae in extracting solution, extraction time and pH of buffer solution. An UV/Vis detector was used to perform the qualitative and quantitative analyses of the extracted flavonid with the using of the standard sample. Results The maximum extraction yield of the crude extract was 5.0533 （mg/g） after 20 min when the mass ratio of Na2B4O7 · 10H2O to raw material was 0.4%, the concentration of Fructus Gardeniae in the extraction solution was 1/12 （g/mL）, and pH of buffer solution was 4.5. The positive reactions to the Molish and HCI-Mg tests suggested that the extracted compound was flavonoid, and FTIR measurements also identified the presence of flavonoid in the extracts. Conclusion This work is expected to provide a basis for further research, development, and utilization of Fructus gardenia in flavonid extraction.

Solution for integer linear bilevel programming problems using orthogonal genetic algorithm

An integer linear bilevel programming problem is firstly transformed into a binary linear bilevel programming problem, and then converted into a single-level binary implicit programming. An orthogonal genetic algorithm is developed for solving the binary linear implicit programming problem based on the orthogonal design. The orthogonal design with the factor analysis, an experimental design method is applied to the genetic algorithm to make the algorithm more robust, statistical y sound and quickly convergent. A crossover operator formed by the orthogonal array and the factor analysis is presented. First, this crossover operator can generate a smal but representative sample of points as offspring. After al of the better genes of these offspring are selected, a best combination among these offspring is then generated. The simulation results show the effectiveness of the proposed algorithm.

Cavitation Optimization for a Centrifugal Pump Impeller by Using Orthogonal Design of Experiment

Cavitation is one of the most important performance of centrifugal pumps. However, the current optimization works of centrifugal pump are mostly focusing on hydraulic efficiency only, which may result in poor cavitation performance. Therefore, it is necessary to find an appropriate solution to improve cavitation performance with acceptable efficiency. In this paper, to improve the cavitation performance of a centrifugal pump with a vaned diffuser, the influence of impeller geometric parameters on the cavitation of the pump is investigated using the orthogonal design of experiment （DOE） based on computational fluid dynamics. The impeller inlet diameter D1, inlet incidence angle Aft, and blade wrap angle ~0 are selected as the main impeller geometric parameters and the orthogonal experiment of L9（3＂3） is performed. Three-dimensional steady simulations for cavitation are conducted by using constant gas mass fraction model with second-order upwind, and the predicated cavitation performance is validated by laboratory experiment. The optimization results are obtained by the range analysis method to improve cavitation performance without obvious decreasing the efficiency of the centrifugal pump. The internal flow of the pump is analyzed in order to identify the flow behavior that can affect cavitation performance. The results show that D1 has the greatest influence on the pump cavitation and the final optimized impeller provides better flow distribution at blade leading edge. The final optimized impeller accomplishes better cavitation and hydraulic performance and the NPSHR decreases by 0.63m compared with the original one. The presented work supplies a feasible route in engineering practice to optimize a centrifugal pump impeller for better cavitation performance.

Determination of Total Flavonoids in Leaves of Paliurus ramosissimus and Orthogonal Experiment Optimization Process

[Objectives] To screen the optimal extraction conditions of flavonoids from leaves of Paliurus ramosissimus( Lour.) Poir.,measure the content of flavonoids in leaves of P. ramosissimus. using the Microplate Reader,and provide experimental basis for the development of medicinal resources of P. ramosissimus. [Methods] The ultrasonic extraction method was adopted and orthogonal design was carried out to study the effects of ethanol concentration( A),ultrasonic time( B),the solid-to-liquid ratio( C) on the extraction of flavonoids from leaves of P. ramosissimus. The Microplate Reader was used to measure the content of flavonoids in leaves of P. ramosissimus. in different extraction conditions,P. ramosissimus. and the optimal extraction conditions were used to measure the content of flavonoids from leaves of P. ramosissimus.[Results]Effects of the ultrasonic extraction method on the extraction rate of flavonoids from leaves of P. ramosissimus: extraction times >ethanol concentration > Ultrasound time > solid-liquid ratio. The screened optimal extraction process was: ethanol concentration of 65%,the solid-to-liquid ratio of 1∶ 25,ultrasonic time of 2 h and extraction times Under this condition,the extraction rate of total flavonoids in leaves of P. ramosissimus. was 2. 56%. [Conclusions] This method is simple and feasibility,reliable,and suitable for rapid measurement with large samples.

Characterization of the adsorption behavior of aqueous cadmium on nanozero-valent iron based on orthogonal experiment and surface complexation modeling

Polyvinylpyrrolidone K-30(PVP) was introduced into the preparation of nanozero-valent iron(n ZVI) and the traditional liquid-phase reduction was improved. The introduction of PVP simplified the traditional method.The n ZVI prepared with this new approach showed excellent surface characters and high performance on the removal of cadmium. TEM results showed that the aggregates of n ZVI can reach to several micrometers in length but less than 100 nm in diameter. The iron particles that were enclosed by a layer of oxide film that is less than10 nm, demonstrated that the n ZVI possesses a core–shell structure. BET results indicate that the specific surface area of the n ZVI was 20.3159 m^2g^(-1). A three factor and three level orthogonal experiment was employed to find out the dominant factor that affects the removal rate of cadmium by n ZVI. Based on the range values, the prominence order of each factor was: initial p H of the solution N initial concentration of cadmium N dosage of n ZVI, the range was 96.453, 3.294 and 1.747, respectively. A simulation was performed under the same condition and a same conclusion was derived, this consistence confirmed the validity of the conclusion that p H is the most significant factor that affects the adsorption efficiency.

CVD Method for Carbon Nanotubes Preparation Based on Orthogonal Experiment Using C_3H_6

Carbon nanotubes (CNTs) have potential applications in many fields, chemical vapor deposition (CVD) is an effective method for CNTs preparation. By CVD, the catalytic pyrolysis temperature, pyrolysis time and the size of the raw gas flow have a great influence on yield rate of CNTs and their form. In this paper, the orthogonal experiment analysis method is used for studying the influence factors of yield rate of CNTs. Research results show that, in the suitable temperature range of preparing CNTs, there is relatively more CNTs with excellent morphology, otherwise, if the temperature is too low, the growth of CNTs will not be sufficient; if the temperature is too high, then CNTs will be generated with excessive defects; with longer growth time of suitable pyrolysis of CNTs, higher yield of CNTs will be obtained; CNTs morphology with reaction time is not proportional; too low or too high raw gas flow rate is not conducive to the growth of CNTs. We have found the optimum conditions for the CNTs preparation: pyrolysis temperature 68 degrees C, pyrolysis time 35 min, propylene flow rate of 180 mL/min. The results have a reference value for the preparation of CNTS and their composites.

Orthogonal design of experiment and analysis of abrasive water jet cutting on carbon fiber reinforced composites

The carbon fiber reinforced composite is a new type of composite material with an excellent property in strength and elastic modulus,and has found extensive applications in aerospace,energy,automotive industry and so on.However,this composite has a strict requirement on processing techniques,for example,brittle damage or delamination often exists in conventional processing techniques.Abrasive water jet machining technology is a new type of green machining technique with distinct advantages such as high-energy and thermal distortion free.The use of abrasive water jet technique to process carbon fiber composite materials has become a popular trend since it can significantly improve the processing accuracy and surface quality of carbon fiber composite materials.However,there are too many parameters that affect the quality of an abrasive water jet machining.At present,few studies are carried out on the parameter optimization of such a machining process,which leads to the unstable quality of surface processing.In this paper,orthogonal design of experiment and regression analysis were employed to establish the empirical model between cutting surface roughness and machining process parameters.Then a verified model was used to optimize the machining process parameters for abrasive water jet cutting carbon fiber reinforced composites.

Application of Orthogonal Experiment in EDM Using the Suspended Powder Fluid

To solve the problems of EDM when using the ordinary fluid and mold manufacturing,this paper provides the orthogonal experiment in the suspended powder fluid,which can optimize the main process parameters.And it also achieves the technology of EDM in the suspended powder fluid primarily.

Parameters optimization for direct contact membrane distillation based on orthogonal experiment

Parameter optimization integrating operation parameters and structure parameters for the purpose of high permeate flux,high productivity and low exergy consumption of direct contact membrane distillation (DCMD) process was conducted based on Taguchi experimental design. L16(45) orthogonal experiments were carried out with feed inlet temperature,permeate stream inlet temperature,flow rate,module packing density and length-diameter ratio as optimization parameters and with permeate flux,water productivity per unit volume of module and water production per unit exergy loss separately as optimization objectives. By using range analysis method,the dominance degree of the various influencing factors for the three objectives was analyzed and the optimum condition was obtained for the three objectives separately. Furthermore,the multi-objectives optimization was performed based on a weight grade method. The combined optimum conditions are feed inlet temperature 75℃,packing density 30% ,length-diameter ratio 10,permeate stream inlet temperature 30 ℃ and flow rate 25 L/h,which is in order of their dominance degree,and the validity of the optimization scheme was confirmed.

Optimization of in vitro Regeneration System of Benihoppe Strawberry (Fragaria × ananassa Duch.) with Orthogonal Experiment Design

[Objective] This study aimed to optimize the in vitro regeneration system of Benihoppe strawberry. [Method] Based on orthogonal experiment, the effects of different medium types, plant growth regulator types and concentrations on the regeneration of adventitious shoots of Benihoppe strawberry leaves were in- vestigated. [Result] IBA is an important factor affecting the multiplication of adventitious shoots of Benihoppe strawberry leaves; the optimal induction medium is MS ＋ 2.0 mg/L TDZ ＋ 0.2 mg/L IBA, with an induction rate of 90.00% ; the optimal differentiation medium is MS ＋ 2.0 mg/L 6-BA ＋ 0.2 mg/L IBA, with a differentiation rate of 8.1% ; the optimal multiplication medium is MS ＋ 1.0 mg/L 6-BA ＋ 0.2 mg/L IBA, with an average multiplication rate of each adventi- tious shoot of 7.67 ; the optimal subculture medium is MS ＋ 0.5 mg/L 6-BA ＋ 0. 1 mg/L 2, 4-D, with an average seeding height in each treatment of 5.98 cm; the optimal rooting medium is 1/2MS ＋ O. 5 mg/L 6-BA ＋ 0. 1 mg/L 2, 4-D, with an average number of roots in each treatment of 4.5. [ Conclusion] This stud- y laid the foundation for further investigating the genetic transformation of strawberry and improving the quality of strawberry at the genetic level.