Optimization of Center of Gravity Position and Anti-Wave Plate Angle of Amphibious Unmanned Vehicle Based on Orthogonal Experimental Method

When the amphibious vehicle navigates in water,the angle of the anti-wave plate and the position of the center of gravity greatly influence the navigation characteristics.In the relevant research on reducing the navigation resistance of amphibious vehicles by adjusting the angle of the anti-wave plate,there is a lack of scientific selection of parameters and reasonable research of simulation results by using mathematical methods,and the influence of the center of gravity position on navigation characteristics is not considered at the same time.To study the influence of the combinations of the angle of the anti-wave plate and the position of the center of gravity on the resistance reduction characteristics,a numerical calculation model of the amphibious unmanned vehicle was established by using the theory of computational fluid dynamics,and the experimental data verified the correctness of the numerical model.Based on this numerical model,the navigation characteristics of the amphibious unmanned vehicle were studied when the center of gravity was located at different positions,and the orthogonal experimental design method was used to optimize the parameters of the angle of the anti-wave plate and the position of the center of gravity.The results show that through the parameter optimization analysis based on the orthogonal experimental method,the combination of the optimal angle of the anti-wave plate and the position of the center of gravity is obtained.And the numerical simulation result of resistance is consistent with the predicted optimal solution.Compared with the maximum navigational resistance,the parameter optimization reduces the navigational resistance of the amphibious unmanned vehicle by 24%.

A Spider Monkey Optimization Algorithm Combining Opposition-Based Learning and Orthogonal Experimental Design

As a new bionic algorithm,Spider Monkey Optimization(SMO)has been widely used in various complex optimization problems in recent years.However,the new space exploration power of SMO is limited and the diversity of the population in SMO is not abundant.Thus,this paper focuses on how to reconstruct SMO to improve its performance,and a novel spider monkey optimization algorithm with opposition-based learning and orthogonal experimental design(SMO^(3))is developed.A position updatingmethod based on the historical optimal domain and particle swarmfor Local Leader Phase(LLP)andGlobal Leader Phase(GLP)is presented to improve the diversity of the population of SMO.Moreover,an opposition-based learning strategy based on self-extremum is proposed to avoid suffering from premature convergence and getting stuck at locally optimal values.Also,a local worst individual elimination method based on orthogonal experimental design is used for helping the SMO algorithm eliminate the poor individuals in time.Furthermore,an extended SMO^(3)named CSMO^(3)is investigated to deal with constrained optimization problems.The proposed algorithm is applied to both unconstrained and constrained functions which include the CEC2006 benchmark set and three engineering problems.Experimental results show that the performance of the proposed algorithm is better than three well-known SMO algorithms and other evolutionary algorithms in unconstrained and constrained problems.

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.

Experiment Study of Optimization of Antimony Ore-processed Wastewater Treatment by Bacillus sp.

Antimony ore-rocessed wastewater was treated with the optimized bacterium Bacillus sp.The effects of the evaluation indices,including the amount of inoculation,pH value,processing time,and temperature,on the treatment of antimony ore-rocessed wastewater were studied through orthogonal experiments.The results show that the degrees of effects of the indices on the removal of antimony from wastewater by Bacillus sp.are in the following descending order：the amount of inoculation,pH value,processing time,and temperature.The optimal treatment conditions were attained when the amount of inoculation was 5％,the pH value was 2.5,the processing time was three days,and the temperature was 30 ℃.

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 experiment design of EMI of security monitoring system in coal mines

Security monitoring system of coal mines is indispensable to ensure the safe and efficient production of colliery. Due to the special and narrow underground field of the coal mine, the electromagnetic interference can cause a series of misstatements and false positives on the monitoring system, which will severely hamper the safe production of coal industry. In this paper, first, the frequency characteristics of the interference source on the power line are extracted when equipment runs normally. Then the finite difference time domain method is introduced to analyze the effects of the electromagnetic interference parameters on the security monitoring signal line. And the interference voltage of the two terminal sides on the single line is taken as evaluating indexes. Finally, the electromagnetic interference parameters are optimized by orthogonal experimental design based on the MATLAB simulation on the normal operation of equipment.

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.

Control System Development and Experimental Study on Ultrasonic Vibration Feeding

Ultrasonic vibration feeding（UVF） method which can quantitatively feed and precisely deposit fine powder is a potential technique for micro feeding.The excitation sources transmit vibration to capillary though the third medium for most UVF devices.The vibrator is directly touched with the capillary can transmit mechanical energy on the capillary as much as possible,and the powder feeding can be controlled more precise.However,there are few reports about it.A direct UVF system which integrates the function of micro feeding,process observing,and powder forming was developed in this work.In order to analyze the effect of the system factors on feeding,a group of L9（3^3） orthogonal experiments are selected to confirm the effect of level change of factors.The three factors are capillary nozzle diameter,amplitude and signal.The flow rate was stable for each combined factors,and the optimum combination for the minimum flow rate are choosing small capillary,small amplitude,and triangular wave orderly.The whole process of feeding includes start point,middle stage and stop stage.Starting of feeding was synchronized to vibration when the amplitude of capillary nozzle is larger than critical amplitude.Then,the feeding process enters the middle stage,the feeding state is observed by the CCD,and it is very stable in the middle stage.Overflow of feeding can＇t be eliminated during the stop stage.The features of the deposited powder lines are analyzed; the overflow can be diminished by choosing small capillary and appropriate ratio of the capillary nozzle diameter to the particle size.Chinese characters lattices were deposited to validate the ability of quantitatively feeding and fixed feeding of UVF.Diameters of all powder dots show normal distribution,and more than 60% dots are concentrated from 550 μm to 650 μm,and the average diameter for all the dots is 597 μm.Most dots positions are well approached to their scheduled positions,and the maximum deviation is 0.27 mm.The new direct UVF system is used to implement experiments,which confirms the precise controllable of feeding.According improve the feeding technique,it suits well for rapid prototyping,chemistry,pharmaceutics and many other fields,which require precise measurement and feed minim powder.

Experiment about Drag Reduction of Bionic Non-smooth Surface in Low Speed Wind Tunnel

The body surface of some organisms has non-smooth structure, which is related to drag reduction in moving fluid. To imitate these structures, models with a non-smooth surface were made. In order to find a relationship between drag reduction and the non-smooth surface, an orthogonal design test was employed in a low speed wind tunnel. Six factors likely to influence drag reduction were considered, and each factor tested at three levels. The six factors were the configuration, diameter/bottom width, height/depth, distribution, the arrangement of the rough structures on the experimental model and the wind speed. It was shown that the non-smooth surface causes drag reduction and the distribution of non-smooth structures on the model, and wind speed, are the predominant factors affecting drag reduction. Using analysis of variance, the optimal combination and levels were obtained, which were a wind speed of 44 m/s, distribution of the non-smooth structure on the tail of the experimental model, the configuration of riblets, diameter/bottom width of i mm, height/depth of 0.5 mm, arranged in a rhombic formation. At the optimal combination mentioned above, the 99% confidence interval for drag reduction was 11.13% to 22.30%.

Application of orthogonal experimental design and Tikhonov regularization method for the identification of parameters in the casting solidification process

The inverse heat conduction method is one of methods to identify the casting simulation parameters. A new inverse method was presented according to the Tikhonov regularization theory. One appropriate regularized functional was established, and the functional was solved by the sensitivity coefficient and Newtonaphson iteration method. Moreover, the orthogonal experimental design was used to estimate the appropriate initial value and variation domain of each variable to decrease the number of iteration and improve the identification accuracy and efficiency. It illustrated a detailed case of AlSiTMg sand mold casting and the temperature measurement experiment was done. The physical properties of sand mold and the interracial heat transfer coefficient were identified at the meantime. The results indicated that the new regularization method was efficient in overcoming the ill-posedness of the inverse heat conduction problem and improving the stability and accuracy of the solutions.

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.

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.

EXPERIMENTAL STUDY ON UPGRADING OF A FINE-SCALED GRAPHITE ORE BY FLOTATION

Based on the quality and analysis of the medium carbon product whose grade was 81%-82%, the emphasis of the study was placed on the orthogonal experiments of roughing flotation reagent and single factors, such as abrasive grain, pulp concentration and the rotating speed of flotation machine. The result with improvement in the grade of concentrate to 95% through the routine floatation method was achieved.

Experimental Analysis on the Variable Polarity Plasma Arc Pressure

Arc pressure is one of the key factors for variable polarity plasma arc（VPPA） and welding pool formation. In this paper, VPPA pressure is measured by pressure transducer and U-tube barometer methods, and advantages and disadvantages of the two methods are compared. The effects of welding parameters, including with straight polarity（SP） current, reverse polarity（RP） current, time ratio of SP to RP, plasma gas flow rate, on VPPA pressure are investigated by using an orthogonal design. The experimental results indicate that the influencing degree of the welding parameters are in the order of plasma gas flow rate, SP current, time ratio of SP to RP, RP current. These results are important to researches of VPPA welding process and its mechanism. The physics behavior of VPPA is taken into account when the above influence mechanisms are analyzed. Firstly, according to the mechanism of the cooling compression to the arc, the compression to VPPA is enhanced with the increase of plasma gas flow, so the VPPA pressure would increase obviously. Secondly, although the temperature of VPPA is as a function of the welding current, the radius of VPPA is also enhanced. So the effects of SP current on VPPA pressure are inferior to the effects of plasma gas flow. Thirdly, VPPA pressure increases as a function of time ratio of SP to RP because the frequency of welding current influences the arc pressure to the some degree; Finally, the RP intervals are farther less than the SP intervals, so the influence to the pressure is minimal.

The gangue preparation coagulant （PFASS） experiment research and application

In order to design a new technological process system to take the polymeric ferric aluminum silicate sulfate（PFASS） and to apply it in wastewater processing, the chemical composition analysis was carried on to the Fuxin gangue, adopted the orthogonal experiment method to obtain optimum response condition of with the acid pickling taking the aluminum in the gangue and with alkali extracting taking the silicon in the gangue, The experiments indicate that the sample chemistry content which tests elect completely conform to the preparation inorganic polymer water treatment coagulant request standard. Used the polymeric ferric aluminum silicate sulfate results in which with the system take as the coagulant of treatment wastewater, used the mercerizing degree, the wastewater pH value, the coagulation time, the coagulant throws increment factors and so on to test and verify its influence on the waste water processing. The result indicates that by using this craft production PFASS in waste water processing, after the processed waste water achieves the emission standard, the processing effect is good.

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.

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.

VIRTUAL EXPERIMENTAL ANALYSIS ON CLEANING ELEMENT OF SUGARCANE HARVESTER

The laws of influence of different factors have been analyzed in order to enhance the working efficiency and fatigue life of the cleaning element in brush shape of the sugarcane harvester. Based on the principle of orthogonal experiment design, the virtual-orthogonal-experimental analysis for the cleaning element is carried out on the finite element analysis （FEA） software-ANSYS after analyzing the nonlinear structural behavior in the working procedure. The results are analyzed with the overall balancing method, and then the optimal combination is got, which is made up of different levels of different factors. Also the optimal combination of design parameters of the cleaning element received fiom the virtual experimental analysis is conducted an experiment to confirm that the virtual analysis model and results are right, and the effect of factors on the function of the cleaning element is obtained by more analysis and further optimizing.