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Minimum quantity lubrication (MQL) has achieved excellent results in precision machining. The geometric parameters of the nozzle play a crucial role in determining the performance of MQL. In this study, the orthogonal experimental method was employed to improve and optimize the performance of MQL. Computational fluid dynamics (CFD) simulation using ANSYS Fluent software was conducted, and the simulation data were statistically analyzed. The effects of six influencing factors, namely, the width of the gas-phase narrow flow region, the taper, the output tube length, the length of the gas-phase narrow flow region, the output aperture, and the pressure, on the performance of MQL were investigated. The results revealed that the order of importance for the six influencing factors differed depending on the evaluation criteria used. The parameter that had the greatest impact on the composite index was the absolute gas velocity at a distance of 0.1 m from the outlet. The optimum combination of geometric parameters for the nozzle was an output aperture of 2 mm, a taper of 40°, a length of the gas-phase narrow flow region of 1.5 mm, a width of the gas-phase narrow flow region of 0.3 mm, an output tube length of 15.5 mm, and a pressure of 5 bar. [ABSTRACT FROM AUTHOR]

An improved design was proposed by incorporating helical fins onto the vortex finder, and the impact on the comprehensive performance of the oil‐gas cyclone separator was analyzed based on flow field characteristics. The results revealed that the integration of helical fins led to a slight enhancement in the overall separation efficiency and a significant reduction in pressure drop, thus contributing to the decrease of energy consumption in industrial processes. The orthogonal experimental design (OED) method was utilized for the discussion and optimization of five structural parameters related to the helical fins. This study provides new insights for the design of internal components of oil‐gas separators. [ABSTRACT FROM AUTHOR]

The incorporation of rare earth oxides and nano-silica has been found to significantly enhance the mechanical and tribological characteristics of phenolic-based hybrid nanocomposites. In this work, the impact of these additives was investigated through single-factor experiments. The study revealed that cerium oxide and yttrium oxide were the primary factors influencing changes in the impact strength, shear strength, coefficient of friction, and wear rate. Additionally, the content of nano-silica exerted the most substantial influence on the hardness and compressive strength of the specimens. Furthermore, the material ratios of the phenolic-based hybrid nanocomposites were optimized using an orthogonal experimental design and a fuzzy comprehensive evaluation method. The optimal material ratio for these nanocomposites was determined to be 2% cerium oxide, 2.5% yttrium oxide, and 3% nano-silica, based on their mechanical, frictional, and wear properties. This research provides valuable insights for the development of new brake friction materials with low friction and high wear resistance and contributes to meeting the demand for polymer composites with superior mechanical performance in diverse applications. [ABSTRACT FROM AUTHOR]

Similar materials play an important role in model testing. In order to meet the demand for similar materials in modeling tests, such as those on coal mining, coal system rocky similar materials were formulated using yellow sand as a coarse aggregate, heavy calcium carbonate as a fine aggregate, and cement and gypsum as binders. Based on the orthogonal experimental design method, four influencing factors, namely the aggregate–binder ratio, heavy calcium carbonate content, cement–gypsum ratio, and moisture content, were selected. Each factor was designed at five levels. Through weighing, uniaxial compression, Brazilian splitting, and variable-angle plate shear tests on 225 specimens under 25 different ratios, five physico-mechanical property indicators of the material, including density, compressive strength, tensile strength, cohesion, and internal friction angle, were obtained under different ratios. The test results indicate that the similar materials formulated with the above raw materials had a wide range of mechanical properties, which met the simulation needs of different types of coal rocks, such as main coking coal, anthracite, shale, etc., in the similar model test. Range analysis was adopted to analyze the sensitivities to each factor, which showed that the density and internal friction angle of similar materials are mainly controlled by the aggregate–binder ratio; the cement–gypsum ratio mainly controls the compressive strength, tensile strength, and cohesion of the material. Analysis of variance (ANOVA) was adopted to analyze the sensitivities to each factor, which showed that the aggregate–binder ratio had a highly significant effect on the density of the material, the cement–gypsum ratio had a highly significant effect on the compressive and tensile strength of the material, the cement–gypsum ratio had a significant effect on the cohesion and density of the material, and the moisture content had a significant effect on the compressive strength of the material. The remaining factors did not significantly affect the material parameters. The results of this study can provide some reference for the selection of coal system rocky similar materials in subsequent physical modeling tests. [ABSTRACT FROM AUTHOR]

To study the heat and mass transfer characteristics of an evaporative cooler for cooling high-temperature working fluids, an experimental device of the evaporative cooler was built, and a corresponding test system was constructed. Then, the experimental study was carried out based on an orthogonal experimental design, and the law and extent of the influence of water flow in the tube, the spray water flow rate, the inlet water temperature in the tube, and the air flow rate on the heat dissipation, cooling efficiency, and heat and mass transfer coefficients were obtained. The correlation equations of the heat and mass transfer coefficients were obtained by fitting the orthogonal experimental data, and the validity of the correlation equations was confirmed by the verification experiment. [ABSTRACT FROM AUTHOR]

Objective: To design appropriate orthosis for hallux valgus, a difficult foot condition that affects a quarter of the body's bones, we need to clarify the numerical biomechanical features, which have not been established in previous biomechanical studies. Therefore, we constructed a finite element model of the bunion foot to investigate the orthopaedic force compensation mechanism. Methods: A patient with moderate hallux valgus was recruited. CT imaging data in DICOM format were extracted for three‐dimensional foot model reconstruction. In conjunction with the need for rapid design of bunion orthosis, a metatarsal force application sizing method based on an orthogonal test design was investigated. The orthogonal test design was used to obtain the hallux valgus angle (HVA) and the inter metatarsal angle (IMA) data for different force combinations. Based on the extreme difference analysis and analysis of variance of the test results, the influence of different force combinations on the bunion angle was quickly determined. Results: The results showed that the stress concentration occurred mainly in the first metatarsal bone. The distribution trend was in the medial and lateral middle of the bone and gradually decreased to the dorsal base of the bone body. The greatest stress occurs in the cartilage between the phalanges and metatarsals. In 25 groups of simulation experiments, HVA was reduced from 27.7° to 13°, and IMA was reduced from 12.5° to 7.3°. Conclusion: Applying detailed orthopaedic force collocation to the first metatarsal column can effectively restore the mechanics and kinematics of hallux valgus, and provide a reference for the treatment of bunion valgus and the design of orthopaedic devices. [ABSTRACT FROM AUTHOR]

The main aim of this article is to hybridize orthogonal experimental design (OED) in different population-based metaheuristics to make them more suitable for structural optimization problems. OED is an efficient statistics method that can predict the optimal combination of a multi-level multi-factor problem with far fewer experiments. The motivation of the current study is to design different guidance (transmission) vectors that can efficiently utilize the search information of a couple of candidate solutions and thus balance the exploration/exploitation capabilities of optimization algorithms. Furthermore, by using this method, the convergence speed and accuracy of the final results are enhanced. Four well-known metaheuristics are selected to strengthen their performance by integrating learning strategies based on OED, known as orthogonal learning (OL), in them, and their viability was validated on a set of benchmark structural optimization problems. The performances of the enhanced metaheuristics are compared with each other and their standard versions. The results are discussed based on accuracy, convergence rate, robustness, and diversity index. Furthermore, the Friedman test is utilized to rank different scenarios to investigate the best one. The results demonstrate the effectiveness of the OL to improve the metaheuristics in comparison with their basic versions and show that OL scenarios are an especially useful tool to strengthen the potency of the algorithms for the most complicated structural optimization problems. [ABSTRACT FROM AUTHOR]

A good outdoor wind environment can guarantee the safety and comfort of student activities. It is also conducive to building energy-saving and low-carbon goals. In this study, the high-rise dormitory area of a university was selected as a research object in the cold region. The study used a combination of numerical simulation and orthogonal tests to analyze the weighting of the influencing factors of the wind environment and to recommend the optimal design scheme. The results indicated that the building layout, building length, width, and height all had different degrees of influence on the outdoor wind environment of the dormitory area. For the slab-type high-rise dormitory, the influence weight of the layout was the strongest, followed by the building height, the width, and, finally, the length. The optimal scheme is a staggered layout with a building length of 50 m, width of 18 m, and height of 85.2 m. The wind environment in this situation performed well in winter and summer. For the tower-type high-rise dormitory, the influence weight of the building height was the greatest, followed by the width, the length, and then the layout. The optimal scheme is a staggered layout with a building length of 26 m, width of 24 m, and height of 85.2 m. The wind environment in this situation performed well. Overall, the study scrutinized the coupling relationship between building morphology and wind environment from the meso-level perspective. At the micro level, we constructed the design method for the dormitory building morphology by considering the wind environment performance as the target. It can assist designers in making decisions during the planning and design phases of project construction to facilitate the positive design of buildings. [ABSTRACT FROM AUTHOR]

High-speed circuit boards are created to meet the high-speed signal transmission requirements of 5G communication technology, but the non-polar resins, flat glass fibers, and multiple and hard fillers used for this purpose have posed new challenges to their micro-hole processing. The quality of micro-hole has always been a decisive factor in board performance. Therefore, this paper aims at proposing a new processing method for improving the micro-hole drilling quality of high-speed circuit boards. By establishing an ultrasonic-assisted drilling tool motion model, analyzing the changes in drilling method, material deformation, chip breakage, and chip removal during ultrasonic-assisted drilling of printed circuit boards, the influence mechanism on micro-hole quality during ultrasound-assisted drilling is studied prudently. Besides, an experimental platform for ultrasonic-assisted drilling is designed and built, and single-factor experiments for verification of ultrasonic effects, optimization of drilling parameters, and orthogonal experiments for ultrasonic-assisted drilling of high-speed circuit boards are conducted on this platform. The experimental results show that the loading of ultrasonic vibration has made an obvious improvement on several machining defects including hole wall roughness, entrance burr, and nail head in micro-hole drilling of high-speed circuit boards. In addition, the influence order of each processing parameter and a better combination of them are discovered, which provides a theoretical research basis and instructions for the improvement of micro-hole quality of high-speed circuit boards. [ABSTRACT FROM AUTHOR]

Dendrobium denneanum is an important medicinal and ornamental plant. Its ornamental and medicinal values are affected by its vegetative growth conditions and chemical composition accumulation. This study adopted an orthogonal experimental design to treat D. denneanum with nine different levels of nitrogen (N), potassium (K), and phosphorus (P). The morphological indicators of the plant were positively correlated with the nitrogen concentration. The polysaccharide content was the highest at 1500 mg·L−1 nitrogen and 3000 mg·L−1 phosphorous and was 26.84% greater than the control. The flavonoid content increased by 36.2% at 500 mg·L−1 nitrogen, 2000 mg·L−1 phosphorous, and 300 mg·L−1 potassium. Principal component score analysis showed that nitrogen had the most significant impact on the various indicators of D. denneanum, followed by phosphorus and potassium. The comprehensive score showed that the T9 treatment (N: 1500 mg·L−1, P: 3000 mg·L−1, K: 500 mg·L−1) had the strongest effect on D. denneanum. Transcriptional analysis showed that compared with the control, the T9 treatment led to 2277 differentially expressed genes (1230 upregulated and 1047 downregulated). This includes fifteen genes enriched in the MAPK signaling pathway, five genes in phenylpropanoid biosynthesis, and two genes in flavonoid biosynthesis. These genes may be involved in regulating plant growth and the biosynthesis of polysaccharides and flavonoids. This study provides guidance for the optimal use of N, P, and K in the cultivation of D. denneanum. [ABSTRACT FROM AUTHOR]

At present, the treatment of tailings is mostly carried out in the form of stacking in tailings ponds, resulting in a huge waste of mineral resources and a major threat to the environment and ecology. Using tailings instead of a part of the cement to make cementitious materials is an effective way to reduce the accumulation of tailings. In this paper, lead–zinc tailings-based cementitious materials were prepared by using lead–zinc tailings, fly ash, and ordinary Portland cement, and the effects of four factors on the mechanical properties of lead–zinc tailings, as well as fly ash content, cement content, and water–binder ratio were studied by orthogonal experiments. The corresponding relationship between the factors and the properties of cementitious materials was determined, and the optimization and prediction of the raw material ratio of lead–zinc tailings-based cementitious materials were realized. The test showed the ratio of raw materials to be at the lowest price ratio. Synchronously the ratio that meets the minimum strength requirements was predicted. When the proportion of fly ash:lead and zinc tailings:cement = 30:40:30 and the water–binder ratio was 0.4, the predicted compressive strength of the prepared cementitious material achieved 22.281 MPa, which meets the strength requirements, while the total content of lead–zinc tailings and fly ash was the highest at this time. [ABSTRACT FROM AUTHOR]

The existing heat dissipation research on double disk magnetic couplers ignores the coupling influence of electromagnetic temperature–stress and other multiphysics fields, and the error between the calculation and analysis results and the measured values is large. Therefore, a multi-parameter optimization method for heat dissipation structures of double disk magnetic couplers based on orthogonal experimental design is proposed. Based on the double disk magnetic coupler model, a three-dimensional finite element model based on fluid–solid–heat coupling is established, with the axial air gap length, input motor speed, the thickness of the permanent magnet in the magnetizing direction, the thickness of the copper plate, the number of fins of the heat dissipation plate and the length of the fins of the heat dissipation plate as design variables. Six-factor and three-level simulation experiments are designed with the minimum temperature of the heat dissipation plate as the objective function, and additionally, orthogonal experiments were designed according to the actual working conditions by selecting the optimal combination of parameters and modifying the model to perform physical tests. The results show that the variables that have the most significant impact on heat dissipation performance from high to low are as follows: axial air gap length, input motor speed, the length of the fins of the heat dissipation plate, the thickness of the permanent magnet in the magnetizing direction, the number of fins of the heat dissipation plate and the thickness of the copper plate. The increase in axial air gap length can effectively reduce the temperature rise, and the maximum decrease can reach 9.76%. Under the same conditions, the input motor speeds are set to 300 r/min, 400 r/min, 500 r/min, 600 r/min and 700 r/min, respectively, and the simulation results are in good agreement with the physical test results, with a maximum error of 4.8%. The error between the simulation result and the physical test result is only 1.9% under the optimal combination of parameters obtained by the orthogonal experiment, which verifies the correctness of the optimization model. In conclusion, the study is of reference significance for the parameter optimization of the heat dissipation structure of the double disk magnetic coupler. [ABSTRACT FROM AUTHOR]

Hepatocyte scaffold is an essential part in bioartificial liver device. We have designed a novel hepatocyte scaffold based on porcine liver extracellular matrix (ECM) and chitosan (CTS) fabrics. This CTS-ECM scaffold can improve cell adhesion and proliferation. In the present study, an orthogonal test was designed to optimize the CTS/ECM composite scaffold, in which ECM concentration, EDC concentration and EDC to NHS ratio were taken as factors, proportion of nitrogen element and hydroxyproline content as indicators. The cytocompatibility of the novel scaffold for C3A hepatocytes was analyzed in vitro. The orthogonal test demonstrated that the optimal scaffold should be based on ECM concentration of 5 mg/mL, EDC concentration of 5 mg/mL, and EDC to NHS ratio 1:1. C3A hepatocytes cultured on the optimized CTS-ECM scaffolds showed stronger proliferation and functionality than those on Cytodex3 microcarriers (p < 0.05). The CTS/ECM composite scaffold may be widely used as a promising hepatocyte culture carrier, especially in bioartificial liver support systems. [ABSTRACT FROM AUTHOR]

Shock wave/boundary layer interaction (SWBLI) is a common phenomenon occurring in the supersonic/hypersonic flow fields, and it can constrain the performance of the vehicle. In the current study, a combined control device of a micro vortex generator (MVG) and a secondary recirculation jet is numerically simulated by using three-dimensional Reynolds-averaged Navier-Stokes equations (RANS) coupled with the SST k-ω turbulence model to control the SWBLI flow field at the incoming Mach number being 2.9. From the obtained results, the combination is able to significantly reduce the volume of the separation zone while maintaining little change in the peak heat flux, and the volume of separation bubble is reduced by 87.81%. At the same time, the flow field details and control mechanism are also clearly captured. Six combined models of MVG and secondary recirculation jets are considered, and the design parameters are optimized based on the model with the best control performance. The results of the orthogonal experimental design and the range analysis provide the relationship between the geometric design variables and the performance parameters of the combination. • A combined control device of a micro vortex generator (MVG) and a secondary recirculation jet was proposed. • Six combined models of MVG and secondary recirculation jets were considered. • The optimized configuration of the combined control device was obtained. • The volume of separation bubble was reduced by 87.81% and by 88.96% after optimization. [ABSTRACT FROM AUTHOR]

The flat-joint model, which constructs round particles as polygons, can suppress rotation after breakage between particles and simulate more larger compression and tension ratios than the linear parallel-bond model. The flat-joint contact model was chosen for this study to calibrate the rock for 3D experiments. In the unit experiments, the triaxial unit was loaded with flexible boundaries, and the influence of each microscopic parameter on the significance magnitude of the macroscopic parameters (modulus of elasticity E, Poisson's ratio ν, uniaxial compressive strength UCS, crack initiation strength σci, internal friction angle φ and uniaxial tensile strength TS) was analysed by ANOVA (Analysis of Variance) in an orthogonal experimental design. Among them, Eƒ, kƒ has a significant effect on E; Cƒ and kƒ have a significant effect on ν; Cƒ, σƒ and kƒ have a significant effect on UCS; Cƒ; σƒ and Eƒ have a significant effect on TS; Rsd has a significant effect on σci; and φf, Eƒ, kƒ, μƒ, and σƒ have a significant effect on φ. Regressions were then carried out to establish the equations for calculating the macroscopic parameters of the rock material so that the three-dimensional microscopic parameters of the PFC can be quantitatively analysed and calculated. The correctness of the establishment of the macroscopic equations was verified by comparing the numerical and damage patterns of uniaxial compression, Brazilian splitting, and triaxial experiments with those of numerical simulation units in the chamber. [ABSTRACT FROM AUTHOR]

The synthesis of sodium N-methyl taurine by direct ammonia hydrolysis of sodium hydroxyethyl sulfonate has the advantages of short process and environmental friendliness, but its development is limited by the rapid quantification of its synthetic product. The influence factors of raw materials on the determination of sodium N-methyl taurine were eliminated by the preparation of simulated reaction products, and an optimization method for the determination of sodium N-methyl taurine in synthetic products by acid-base titration was obtained by orthogonal experimental design. The results show that the degree of influence on the titration results of sodium N-methyl taurine is as follows: the amount of formaldehyde added, the amount of water added and the quality of sample, and the amount of formaldehyde added has a significant effect on the titration results. The optimized conditions were as follows: the sampling mass was about 0.5 g, the amount of water was 30 mL, and the amount of formaldehyde was 3 mL. The relative error of the optimized results is less than 0.6%,which provides a basis for the development of analytical methods for this reaction and similar reactions. [ABSTRACT FROM AUTHOR]

Rubber permeable concrete is a kind of environmental friendly concrete. It has good application prospects, but its performance remains to be studied.Five factors including water-binder ratio, rubber particle size, rubber content, VAE-707 emulsion content and target porosity were selected to conduct orthogonal test design for rubber pervious concrete to study the effects of compressive resistance, flexural strength and water permeability. By using matrix analysis and grey decision, the optimal mix ratio of rubber permeable concrete was obtained as follows. Water-cement ratio 0.3, rubber particle size 0.425 mm, rubber particle content 3%, VAE-707 emulsion content 6%, and target porosity rate 16%. Among them, the contribution rate of target porosity to pervious concrete is the largest. The compressive and flexural strength of pervious concrete decreases with the increase of target porosity, while the permeability coefficient shows an opposite rule. The measured porosity of pervious concrete is generally lower than the designed porosity, with the effective porosity accounting for about 80% ～ 90% of the total porosity, and the closed porosity accounting for about 10%～20% of the total porosity. [ABSTRACT FROM AUTHOR]

This paper focuses on researching the various factors that influence the material melting rate during the hot air melting process. To achieve this purpose, the paper proposes a melting model for Acrylonitrile-Butadiene-Styrene (ABS) plastic under hot air heating based on Computational Fluid Dynamics (CFD). Orthogonal experiments were conducted based on the parameter range of each factor obtained in the pre-experiment. The results showed that the outlet distance, hot air velocity, hot air temperature, and their interaction items are important factors that affect the melting rate of ABS materials. Based on the simulation results, a multiple nonlinear regression model was constructed to predict the melting rate under different parameters. Comparing the simulation values with the predicted values of the multiple nonlinear regression model, the error between the two was no >10%, indicating the effectiveness of the prediction model. The research results can help guide the hot air welding melting process for different materials and characteristics, and provide a certain reference value for the development of hot air welding technology. • Welding of airbag labels was performed using hot air welding technology; • Realizes real-time monitoring of melt quality during the material melting process • Using CFD modeling to study the effects of outlet distance, hot air velocity, and hot air temperature on the melting rate. [ABSTRACT FROM AUTHOR]

Hence, a novel hydrophobic intumescent flame-retardant coating is prepared using melamine polyphosphate (MPP), aluminum diethylphosphinate (ADP), and anhydrous transparent powder (ATP) as intumescent flame retardants (IFR), doped with polytetrafluoroethylene emulsion (PTFE) for flame-retarding plywood. The IFR/PTFE coatings are prepared using the sol-gel method. Firstly, the cone results demonstrate a significant enhancement in the flame retardancy of IFR/PTFE coatings. The Total Heat Release (THR) is reduced from 35.71 MJ·m−2 to 16.07 MJ·m2, while the Flame Retardancy Index (FRI) increases from 1 to 32.52. Moreover, according to the 3D Jander model (n = 3), the activation energy (E α) for the coating rises from 209.52 to 253.50 kJ·mol−1 in the range of 327 °C to 430 °C. The coating achieves a maximum water contact angle of 113°. Notably, the optimal formulation of IFR is explored through orthogonal experiments, and the further optimized formulation (MPP: 21.16 wt%, ADP: 5.05 wt%, ATP: 10.17 wt%) is predicted using regression analysis model based on the Design of Experiments (DOE) method. Generally, it explores a strategy for preparing efficient IFR/PTFE hydrophobic coatings with promising prospects. [Display omitted] • MPP/ADP/ATP enhances the flame retardancy of PTFE-based hydrophobic coating. • Orthogonal experiment and regression model are used to optimize the formula of coating. • E α increases from 209.52 to 253.50 kJ·mol−1 at 327 °C ~ 430 °C by 3D Jander method (n = 3). [ABSTRACT FROM AUTHOR]

An intermittent heat charging and discharging strategy is proposed for on-demand thermal utilization in a three-layer latent heat storage unit filled with nanoparticle-enhanced phase change materials. To optimize the utilization ratio of phase change materials, and the stored and released thermal exergy amounts, a multi-objective prediction and optimization methodology combining orthogonal experimental design, range and variance analyses, multi-nonlinear regression models, and non-dominated sorting genetic algorithm-II is introduced while considering the variables of nanoparticle concentration, heat transfer fluid velocity, and intermittent time interval. Results show that the time interval presents the most significant influence. Multi-nonlinear regression models for the above three variables are established with determination factors of 0.9871, 0.9625, and 0.9253, respectively. The ultimate optimal results are 0.8, 57094.03 J, and 43066.73 J, achieved at the three variables of 44.37 min, 0.38 m s−1 and 8.99%, respectively. The maximum verification error of 5.11% indicates the reliability of this methodology. The methodology aims to enhance the overall performance of the three-layer latent heat storage system by mitigating the constraints associated with single-performance optimization. [ABSTRACT FROM AUTHOR]

The lithium-ion battery, widely adopted in electric vehicles, demands precise thermal management to ensure optimal performance, longevity, and safety. This study introduces a novel serpentine flow channel with branch structure (SFCWBS) for practical engineering applications. Employing an orthogonal experimental design, the impact of key branch structure parameters, namely inlet angle, width, and confluence position, on thermal balance performance and power loss is thoroughly assessed. The optimised SFCWBS configuration significantly enhances battery pack temperature uniformity while concurrently reducing pressure drop, as revealed by simulation results. The maximum average temperature difference is reduced from 1.16 °C to 0.38 °C, and the pressure drop is reduced from 98.2 kPa to 92.3 kPa. • A novel Serpentine Flow Channel with Branch Structure is proposed for BTMS. • Inlet angle, width, and confluence position affect heat dissipation and flow effect. • A relatively optimal branch structure is designed with an orthogonal experiment. • Maximum average temperature difference and pressure drop are reduced effectively. [ABSTRACT FROM AUTHOR]

Regarding the creep-fatigue behavior of hydrogen storage bed (HSB) structures under high-temperature loading and internal pressure loading under repeated hydrogen absorption and desorption process, the heat transfer characteristics and creep-fatigue life during a complete service process in HSB were calculated using Ansys Workbench and Ncode software, and the reliability of the life results calculated by finite element method were validated using ASME code. Based on orthogonal experimental design (OED) theory, an orthogonal experimental table with 4 factors and 5 levels was compiled for the four process parameters: diameter of cooling tube, thickness of cylinder wall, spacing between inner and outer layers, and heat transfer coefficient of condensate. Moreover, an optimization method based on OED coupled with BP ANNs was proposed to find the best process parameters. And the importance of each parameter was analyzed based on range analysis and analysis of variance (ANOVA) to divide the process parameters into rough optimized parameters and precise optimized parameters in this method. In order to identify the optimal process parameter combination of HSB, the maximum life and corresponding process parameter combinations were identified based on OED and the combined method, respectively. The maximum life identified by the combined method proposed in this work is increased by 10.23 % than that identified by OED, which shows the superiority of this combined method. • An approach for directly calculating the creep-fatigue life of hydrogen storage bed based on finite element method was established. • An optimization method based on OED coupled with BP ANNs was proposed, overcoming the respective shortcomings of OED and ANN. • The optimal process parameter combination of HSB for the maximum creep-fatigue life based on OED and the combined method was identified. [ABSTRACT FROM AUTHOR]

To obtain the tire–pavement peak adhesion coefficient under different road states, a field measurement and FE simulation were combined to analyze the tire–pavement adhesion characteristics in this study. According to the identified texture information, the power spectral distribution of the road surface was obtained using the MATLAB Program, and a novel tire hydroplaning FE model coupled with a textured pavement model was established in ABAQUS. Experimental results show that here exists an "anti-skid noncontribution area" for the insulation and lubrication of the water film. Driving at the limit speed of 120 km/h, the critical water film thickness for the three typical asphalt pavements during hydroplaning was as follows: AC pavement, 0.56 mm; SMA pavement, 0.76 mm; OGFC pavement, 1.5 mm. The road state could be divided into four parts dry state, wet sate, lubricated state, and ponding state. Under the dry road state, when the slip rate was around 15%, the adhesion coefficient reached the peak value, i.e., around 11.5% for the wet road state. The peak adhesion coefficient for the different asphalt pavements was in the order OGFC > SMA > AC. This study can provide a theoretical reference for explaining the tire–pavement interactions and improving vehicle brake system performance. [ABSTRACT FROM AUTHOR]

Machine-made sand instead of natural sand has become an inevitable choice for the sustainable development of the concrete industry. Orthogonal experiment and grey correlation analysis were used to investigate the performance of machine-made tuff sand concrete. The optimal concrete mix ratio of machine-made sand was obtained by orthogonal test and its working performance was verified. Grey correlation analysis was applied to compare the factors affecting the mechanical properties of the machine-made sand concrete. The test results show that the sand rate has the greatest degree of influence on slump and slump expansion. The mineral admixture has the greatest effect on the 7-day compressive strength of the concrete. Additionally, the water–cement ratio has the greatest influence on the 28-day compressive strength. The mechanical and working properties of the machine-made sand concrete reach the optimum condition when the mineral admixture is 20%, the sand rate is 46%, the stone powder content is 10% and the water–cement ratio is 0.30. Comparing different fine aggregate concretes of similar quality, we conclude that the mechanical and working properties of tuff sand concrete and limestone sand concrete and river sand concrete are similar. The compressive strengths of the mechanism concrete show the greatest correlation with roughness and the least correlation with stone powder content. The stone powder content has almost no effect on the compressive strength of concrete when the stone powder content does not exceed a certain range. The results of the study point out the direction for the quality control of concrete with machine-made sand. [ABSTRACT FROM AUTHOR]

We developed a composite system combining self-targeted carbon dots and thermosensitive in situ hydrogels for ocular drug delivery of diclofenac sodium (DS). DS-CD C-HP nanoparticles were prepared by loading DS on the surface of CD C-HP via electrostatic interactions. An orthogonal experimental design was selected to screen the optimal thermosensitive hydrogel matrices and then DS-CD C-HP nanoparticles were embedded to form the composite system. The physicochemical properties and release behavior of this system were characterized, and in vivo fluorescence imaging was carried out. Corneal penetrability and in vitro cellular studies (cytotoxicity, cell imaging and cell uptake) were performed to test the feasibility and potential of this ocular delivery system. Finally, the optimal gel matrix consisting of Poloxamer 407: Poloxamer 188: HPMC E50 was 21:1:1 (w/v %), and the gelation temperature before adding artificial tear fluid was 26.67°C and 34.29°C, respectively. This system has the characteristics of biphasic drug release. In addition, the corneal penetrability and in vivo fluorescence study indicated that corneal transmittance was enhanced and drug retention time was extended. Cellular studies revealed that the DS-CD C-HP -Gel has good cytocompatibility and CD44 targeting. In summary, this composite system combines carbon dots with hydrogels, offering new potential for ocular drug delivery. [ABSTRACT FROM AUTHOR]

In order to explore the effect of rice straw on the high and low temperature rheological properties of asphalt mortar, orthogonal experiments were used to investigate the effects of different fiber content, length and powder rubber. The dynamic shear rheological test and bending beam rheological test were carried out to evaluate the effect of rice straw on the high and low temperature performance of asphalt mortar. The influence of different factors on its performance changes was analyzed. The results show that each factor has different degrees of influence on the rheological properties of rice straw fiber asphalt mortar. Influence. The powder-to-rubber ratio plays a decisive role in its performance. The increase of the powder-to-rubber ratio significantly enhances the high temperature deformation resistance of the fiber asphalt mortar, but at the same time the stiffness The modulus rises sharply, and the crack resistance at low temperature drops sharply, so the powder-to-rubber ratio is recommended to be 1.0~1.2. The increase of fiber content and length makes the high temperature performance of the glue At present, there is a trend of strengthening first and then weakening. The fiber-asphalt mortar with a content of 4% and a length of 9 mm at -12 and -18 ℃ has the best low-temperature crack resistance. Combined with the analysis of high and low temperature properties of the mortar, it is recommended that the fiber length of 9mm and the content of 4% are the best preparation process. [ABSTRACT FROM AUTHOR]

In order to reduce the noise in the electric vehicle, the sound package is optimized by wrapping the motor with sound absorption and insulation materials. Firstly, the SEA model of electric vehicle is established, and its accuracy is verified. Then the orthogonal experimental design method is used to optimize the wrapping material, thickness and the percentage of coverage, at the same time, the lightweight of automobile is considered in order to control the mass of sound package. After optimization, the sound pressure level of the driver's head is greatly reduced under various frequencies. The motor package can effectively reduce the interior noise of the vehicle, and the orthogonal experimental design method can avoid the blindness of optimization. The combination of the two provides a certain guidance for the optimization of the sound package of the electric vehicle motor. [ABSTRACT FROM AUTHOR]

In order to alleviate the dust pollution in the fully mechanized mining face, the novel negative pressure entrainment dust collector was optimized by the method of orthogonal experimental design and numerical simulation. The influences of nozzle distance, throat diameter and diffusion angle on the atomization efficiency of the proposed dust collector was investigated. The obtained results showed that the optimum ejection dust removal performance of the developed negative pressure entrainment dust collector was obtained for throat diameter 80 mm, throat distance 60 mm and diffusion angle 20 degrees. Under these conditions, air suction rate at the entrance of contraction section was 17.48 m3/min and the average droplet size and mass concentration were 62.99 μm and 0.034 kg/m3, respectively. Here, we have proposed a local closed atomization control dust removal technology for hydraulic support areas based on the optimized negative pressure entrainment dust collector. After the application of the developed system in 2307 fully mechanized mining face in Tangkou Coal Mine, the average total dust of measuring points was decreased from 337.90 to 49.53 mg/m3 and average exhaust dust was decreased from 271.80 to 41.40 mg/m3. The average dust removal rates of total dust and exhaled dust were 85.17% and 84.74% respectively, and dust removal efficiency of the proposed system was obviously confirmed. Unlabelled Image • Negative pressure entrainment dust collector was optimized. • Distribution characteristics of spray field was revealed by numerical simulation. • A local closed control and removal technology based on hydraulic support was proposed. • Local closed atomization control and dust removal technology was proposed. [ABSTRACT FROM AUTHOR]

Based on orthogonal experimental design (OED), the effects of the sintering pressure, sintering temperature and holding time on the mechanical properties of 50 vol% silicon carbide particle (SiCp)/2024Al composites prepared by spark plasma sintering (SPS) were investigated. The sintering pressure had the greatest effect on the density and bending strength of the material among these three factors, followed by sintering temperature and holding time. The optimised process conditions for producing the 50 vol% SiCp/2024Al were sintering at 550 °C for 5 min under 40 MPa, which resulted in a composite material with a density of 99.7% and good interface bonding with a comparatively high bending strength of 766.65 MPa. This work provides a promising method to produce high volume fraction composites that can meet high strength requirements. [ABSTRACT FROM AUTHOR]

• Proposed high-performance concrete and developed a regression model to predict HMRAC's compressive strength. Recycled Coarse Aggregate Concrete (RAC) is a type of concrete that uses recycled coarse aggregate (RCA) instead of natural coarse aggregate (NCA), which helps to reduce the negative environmental impact of construction waste. In order to improve the low compressive strength of RAC and solve the problem of shortage of natural aggregates, this paper develops a high-performance concrete called recycled coarse aggregate concrete with silica fume-slag-fly ash hybrid micro-powders (HMRAC) by replacing part of the cement with a mixture of micronized silica fume (SF), slag (SG) and fly ash (FA) and using RCA of 50% mass instead of NCA. The optimum combination parameters and prediction model for the compressive strength of HMRAC were also proposed by orthogonal experimental design. A constant water-cement ratio of 0.45 and a 50% mass replacement of natural coarse aggregate (NCA) by recycled coarse aggregate (RCA) were adopted in the experiment, and the mass replacement ratios of silica fume (SF), slag (SG), and fly ash (FA) for ordinary Portland cement (OPC) were used as the test variables. In total, 16 combinations were tested, including a control group where 50% of the NCA mass was replaced by RCA. First, we investigated the degree and significance of the effect of the mass substitution ratio of SF, SG, and FA on the compressive strength of HMRAC using analysis of variance (ANOVA) and extreme difference analysis. Then, we determined the optimal combination ratio of SF, SG, and FA. Secondly, multiple regression analysis was used to propose a multiple regression model for predicting the compressive strength of HMRAC. Finally, we computed and analyzed the carbon emissions of HMRAC. The results indicated that the mass substitution rates of FA and SG had a greater effect on the compressive strength, and the mass substitution rate of SF had a lesser effect on the compressive strength. The interaction of SF, SG, and FA can significantly enhance the compressive strength of RAC. The optimal compressive strength performance of HMRAC was observed when the proportions were as follows: SF constituted 10%, SG made up 15%, and FA accounted for 5%. The regression model has reasonable accuracy and a small standard deviation of residuals. It can effectively predict the compressive strength value of HMRAC, aligning well with the experimental results. It exhibits a superior carbon reduction rate of 21.90%, compared to conventional concrete. [ABSTRACT FROM AUTHOR]

The relative shear thickening effect (RSTE) of shear thickening gel (STG) is influenced by nine factors, including the mass ratio of four components and five process parameters. To obtain high RSTE, the constrained uniform mixture design and orthogonal experimental design were implemented to obtain the optimal ratio of each component and optimal process parameter combination, respectively. Then, validation experiments were carried out to verify the accuracy of the obtained results. The optimal mass ratio is m(polydimethylsiloxane, PDMS):m(pyroboric acid, PA):m(anhydrous ethanol, AE):m(benzoyl peroxide, BPO) = 66.42:21.48:10.66:1.45. The impact degrees and optimal process parameter combinations are PDMS viscosity (500 mm2/s)>reaction temperature (240 °C)>curing time (60min)>reaction time (600min)>curing temperature (120min). The RSTE averages obtained from the validation experiments were all above 300000 %, with a maximum of 345843 %. STG with high RSTE can be obtained through experimental analysis, shedding light on improving the subsequent preparation process of STG. • The constrained uniform mixture design was conducted to establish the regression equation. • An IGWO algorithm was used to obtain the optimal ratio of each component. • The response surface method was used to study the interactive effects. • The Orthogonal experiment was designed to study impact degrees and process parameter. [ABSTRACT FROM AUTHOR]

The use of radiotherapy in tumor treatment has become increasingly prominent and has emerged as one of the main tools for treating malignant tumors. Current radiation therapy for glioma employs 125I seeds for brachytherapy, which cannot be combined with radiotherapy and chemotherapy. To address this limitation, this paper proposes a dual-microcavity capsule structure that integrates radiotherapy and chemotherapy. The Monte Carlo simulation method is used to simulate the structure of the dual-microcavity capsule with a 125I liquid radioactive source. Based on the simulation results, two kinds of dual-microcavity capsule structures are optimized, and the optimized dual-microcavity capsule structure is obtained. Finally, the dosimetric parameters of the two optimized dual-microcavity capsule structures are analyzed and compared with those of other 125I seeds. The optimization tests show that the improved dual-capsule dual-microcavity structure is more effective than the single-capsule dual-microcavity structure. At an activity of 5 mCi, the average absorbed dose rate is 71.2 cGy/h in the center of the optimized dual-capsule dual-microcavity structure and 45.8 cGy/h in the center of the optimized single-capsule dual-microcavity structure. Although the radial dose function and anisotropy function exhibite variations from the data of other 125I seeds, they are generally similar. The absorbed dose rate decreases exponentially with increasing distance from the center of the capsule, which can reduce the damage to the surrounding tissues and organs while increasing the dose. The capsule structure has a better irradiation effect than conventional 125I seeds and can accomplish long-term, stable, low-dose continuous irradiation to form local high-dose radiation therapy for glioma. • Development of a novel dual-microcavity capsule structure for integrated radiotherapy and chemotherapy of glioma. • Optimize capsule structure and achieve high dose rates in the tumor center using Monte Carlo simulation. • Orthogonal tests were performed to optimize the capsule design parameters. • Improved dual-capsule dual-microcavity structure shows better efficacy than single-capsule dual-microcavity structure. [ABSTRACT FROM AUTHOR]

Vinyl-tris(2,2,2-trifluoroethoxy)silane (VTTFEOS) has been prepared by the alcoholysis of vinyltrichlorosilane with 2,2,2-trifluoroethanol, and an orthogonal design method has been used to determine the key factors affecting the yield of the product. Results indicate that the yield is significantly influenced by the molar ratio of the feedstocks and the condensation temperature. VTTFEOS was purified by means of vacuum distillation and its structure was characterized by 1H, 13C, and 19F NMR spectrometries, FTIR spectroscopy, and GC-MS. The densities and the refractive indices of VTTFEOS at 20 and 25 °C are reported. [ABSTRACT FROM AUTHOR]

The development of electric vehicles is an important trend in the automotive industry, in which the performance of power batteries is greatly affected by temperature. In recent years, it has been widely concerned that the performance of power batteries at low temperature will lead to the vehicle failure to start because of the bad thermal equilibrium of power battery heating system. This paper studies the thermal equilibrium performance of battery liquid heating system at low temperature. Inlet temperature, heating time, ambient temperature, and their coupling relationship to battery thermal equilibrium performance are studied by orthogonal experimental design method. It is expected that this study can provide reference for the parameter selection of battery heating system. [ABSTRACT FROM AUTHOR]

The aim of this study is to identify ways for controlling forming-induced distortion of a dissimilar Ti6Al4V/AA1050 laminate prepared by a novel non-equal channel lateral co-extrusion process, which is a modified equal-channel angular pressing process (ECAP) and is characterized by stimulant diffusion bonding via a decrease in the activation energy. First, a thermo-mechanical model of non-equal channel lateral co-extrusion based on the DEFORM-3D software was established along with the introduction of modeling technology. Second, the forming-induced distortions of the dissimilar Ti6Al4V/AA1050 laminate were evaluated in terms of all designed extrusion parameters such as the stripping angle, average velocity relative deviation, average temperature relative deviation, and extrusion force. Third, the process optimization for the mitigation of co-extrusion distortions was performed by employing the orthogonal experimental design and signal-to-noise ratio method. Finally, the experimental validation of numerical model was carried out by using the optimal process configuration. The variable analysis of the results indicates that the pre-heating temperature and the ram speed have a considerable effect on forming-induced distortion modes. The influences of process parameters on the average temperature relative deviation are obviously greater than that on the stripping angle and average velocity relative deviation. In addition, the impact of process parameters on the extrusion force is similar to that of the average temperature relative deviation. The experimental forming-induced distortion of the co-extruded laminate is in good agreement with the simulation result. Thus, this work provides an alternative guideline for the manufacture and distortion control of dissimilar bimetal laminates prepared by co-extrusion. [ABSTRACT FROM AUTHOR]

A kind of low cost, high breakage resistance ceramic proppant special for exploitation of the coal‐bed methane is successfully produced. The producing conditions are optimized through orthogonal experimental design method. The breakage resistance results of the orthogonal analyses show the best condition of this kind of ceramic proppant is A4B3C3D2, which means sintering temperature of 1350 °C, manganese mineral powder content of 5 wt.%, weight ratio of 75/25 (second grade bauxite to mujie clay), and holding time of 3 h. The ceramic proppants under this very condition of A4B3C3D2 are then prepared and their phase structure and microstructure are characterized subsequently. X‐ray diffraction pattern exhibits that mullite and corundum are the main crystallographic phases. Scanning electron microscopy illustrates the A4B3C3D2 sample is with non‐porous morphology and small amount of corundum grains and liquid phase, which play the role of improving strength. It reveals the orthogonal experimental design is a feasible optimization method and the ceramic proppant made under the condition of A4B3C3D2 is a promising material for exploiting the coal‐bed methane resources. The conditions for preparation of a kind of low cost, high‐breakage‐resistance ceramic proppant were optimized through orthogonal experimental design method. Nearly all the grains show a uniformly acicular morphology that represents the mullite grains, which intertwine around each other, but apparent pores are also formed. While a small amount of liquid phase can be observed, and few apparent pores can be seen. Both the generation of moderate liquid phase and the increasing corundum phase contribute to the better breakage resistance of the sample A4B3C3D2 than that of A4B3C2D1. [ABSTRACT FROM AUTHOR]

Background: Individualized and accurate implantation of a tibial prosthesis during total knee arthroplasty (TKA) can assist in uniformly distributing the load and reducing the polyethylene wear to obtain a long-term prosthetic survival rate, but individualized and accurate implantation of a tibial prosthesis during TKA remains challenging. The purpose of this study was to optimize and individualize the positioning parameters of a tibial prosthesis to improve its accurate implantation using a new method of finite element analysis in combination with orthogonal experimental design.Methods: Ten finite element models of TKA knee joint were developed to optimize the implantation parameters (varus angle, posterior slope angle, and external rotation angle) of tibial prosthesis to reduce the peak value of the contact pressure on the polyethylene liner according to the method of finite element analysis in combination with orthogonal experimental design. The influence of implantation parameters on the peak value of the contact pressure on the polyethylene liner was evaluated based on a range analysis in orthogonal experimental design.Results: The optimal implantation parameters for tibial prosthesis included 0° varus, 1° posterior slope, and 4° external rotation. Under these conditions, the peak value of the contact pressure on the polyethylene liner remained the smallest (16.37 MPa). Among the three parameters that affect the peak value of the contact pressure, the varus angle had the greatest effect (range = 6.70), followed by the posterior slope angle (range = 2.36), and the external rotation angle (range = 2.15).Conclusions: The optimization method based on finite element analysis and orthogonal experimental design can guide the accurate implantation of the tibial prosthesis, reducing the peak value of the contact pressure on the polyethylene liner. This method provides new insights into the TKA preoperative plan and biomechanical decision-making for accurately implanting TKA prosthesis. [ABSTRACT FROM AUTHOR]

According to the slow convergence speed and low searching precision of traditional backtracking search optimization algorithm, this paper proposed an improved algorithm based on cellular automaton and orthogonal experimental design. Firstly, the algorithm intrcxluced orthogonal experimental design method into the crossover operator to obtain representative high-quality offspring individuals. Then based on the neighbor mcxlel of cellular automaton, it carried out the orthogonal crossover operation of multiple parents in the domain for individuals, which was beneficial to improve the mining capacity and search efficiency of the algorithm. Finally, in order to balance the global searching and local searching ability of the algorithm, it introduced the dynamic proportional weight of excellent individuals into the cross-population to select and update them, with adopted a new dynamic variation equation. The simulation experiments selected 12 standard test functions and compared with 6 other well-behaved algorithms, the results show that the improved algorithm has obvious advantages in convergence speed and optimization accuracy. [ABSTRACT FROM AUTHOR]

Due to the complicated dredging operation of the cutter suction dredger, most scholars at home and abroad have used the working characteristics of the key equipment of the cutter suction dredger to carry out related research and establish its mathematical model. However, from the basic principles, it is inaccurate to establish the input-output model of the cutter suction dredger control system, which is a multi-parameter, non-linear, large time-delay system, and can not meet the needs of the actual control system. In this paper, the data-driven method is used to solve the black box problem between the control variables and the instantaneous output in the cutter suction dredger control system. The experimental results show that the predicted results of RBF neural network are reliable under different working conditions, and the model can provide accurate nonlinear mathematical model for the next model predictive control. [ABSTRACT FROM AUTHOR]

This study aimed to provide a comprehensive investigation into factors influencing the thermal effect in robot assisted osteotomies utilizing a piezoelectric osteotome and to identify an optimal combination of factors that minimize the thermal effect in an orthogonal experimental design. Fresh bovine cortical bone was cut under standardized conditions using a robot arm, a piezoelectric osteotome, and a cooling system. Temperature was monitored and the histological depth of osteocyte thermal necrosis was examined to quantify the thermal effect(s). Eighteen experimental trials were conducted according to the standard L18 (21 × 37) orthogonal design table to explore the roles of 6 factors: power of the piezoelectric osteotome, cutting depth, cutting speed, coolant type, coolant flow velocity, and coolant temperature. Our data showed that coolant flow velocity, coolant temperature and cutting speed significantly influenced temperature (p <.05), while no significant temperature increase was identified relating to cutting depth, power of the piezoelectric osteotome and coolant type. The findings of histological osteocyte thermal necrosis correlated with the results of the temperature change. Coolant flow velocity, coolant temperature and cutting speed were key factors influencing the thermal impact of the piezoelectric osteotome. With proper combination of these 3 factors, a piezoelectric osteotome is safe to use from a thermal perspective. • Robot assisted piezosurgical osteotomy has significant temperature rise. • Depth and percentage of histological osteonecrosis correlates to temperature rise. • Six factors were explored to minimize temperature rise. • Coolant flow velocity, coolant temperature and cutting speed are the key factors. • Thermal necrosis can be minimized to below 47 °C with proper settings. [ABSTRACT FROM AUTHOR]

• The twist angle has the most significant effect on the winglet of VAWTs. • The winglet's influence increases along the blade span towards the tip. • A winglet can weaken the tip vortex and enhance the power coefficient of the VAWT. Vertical axis wind turbines (VAWTs) have been attracting an increasing attention in recent years because of their potential for effectively using wind energy. The tip vortices from the VAWT blades have a negative impact on the power efficiency. Since a winglet has been proved to be effective in decreasing the tip vortex in the aerospace field, this paper numerically studies the aerodynamic effect of appending a winglet on the blade of a VAWT. Based on the theoretical motion pattern of the VAWT blade, this paper simplifies the three-dimensional full-scale rotor simulation to a one-blade oscillating problem in order to reduce the computational cost. The full rotor model simulation is also used in validating the result. The numerical approach has been validated by the experimental data that is available in the open literature. Six parameters are applied in defining the configuration of the winglet. The orthogonal experimental design (OED) approach is adopted in this paper to determine the significance of the design parameters that affect the rotor's power coefficient. The OED results show that the twist angle of the winglet is the most significant factor that affects the winglet's performance. A range analysis of the OED results produces an optimal variable arrangement in the current scope, and the winglet's performance in this variable arrangement is compared with the blade without a winglet. For the single blade study, the comparison result shows that the optimal winglet can decrease the tip vortices and improve the blade's power performance by up to 31% at a tip speed ratio of 2.29. However, for the full VAWT case, the relative enhancement in the power coefficient is about 10.5, 6.7, and 10.0% for TSRs of 1.85, 2.29, and 2.52, respectively. The winglet assists in maintain the pressure difference between the two sides of the blade, thus weakening the tip vortex and improving the aerodynamic efficiency of the surface near the blade tip. [ABSTRACT FROM AUTHOR]

A reasonable choice of the physical and contact parameters directly affects the accuracy of the simulation results, particularly when the discrete element method (DEM) is used to study the particle motion or collision events. To investigate the mixing uniformity of irregular gravel and sand materials in the rotating drum, the physical properties of irregular particles were measured, and various experiments were devised to calibrate the contact parameters of particles. Based on the measured parameters, several typical irregular gravel particle models were established by DEM, and the numerical simulations of the mixing uniformity of gravel and sand materials in the rotating drum were also carried out. Aiming to analyze the significance of each factor, the gravel filling degree, the rotational speed of the drum, the number of lifters and the diameter of the drum were selected as the influencing factors, and three levels were established to carry out orthogonal experimental research on material mixing in the rotating drum. The extent of mixing was quantitatively characterized by the Lacey mixing index. According to orthogonal analysis, the rotational speed was the most significant factor that influenced mixing, with a confidence level of more than 95%, and the diameter of the drum was the least significant. Furthermore, the range analysis showed that the optimal combinations of the experimental conditions were a gravel filling degree of 10%, 40 rpm rotational speed of the drum, 12 lifters and a 200 mm diameter drum. Unlabelled Image • Physical properties of irregular sand and gravel particles were measured. • Several irregular gravel particles models were established by DEM method. • Mixing uniformity was studied according to orthogonal experimental. • The sensitivity degree of each factor on mixing uniformity was investigated. [ABSTRACT FROM AUTHOR]

• Established a full-scale, 3D model of the shield machine. • Experiment result of simulation of the airflow-dust coupling field was analyzed. • Field measurements verify the accuracy of numerical simulation. • The optimization model is obtained by orthogonal experiment. A large amount of dust is mainly generated during the construction of the shield tunneling machine. In order to achieve the optimal dust removal effect, this research took the shield section of Jiaozhou North Station of Qingdao Metro Line No. 8 to Jiaodong Airport Station (China) as a case study. For this purpose, the numerical simulation and orthogonal design were undertaken to optimize the parameters of the ventilation and dust removal system for a shield tunneling machine, and to study the influence of each parameter on the dust removal from three aspects, including the distance of pressure tuyere, the air volume of the pressure tuyere, and the distance of the air inlet. The results of the analysis showed that the distance of the pressure tuyere is the main parameter to control the dust removal, and the two other factors had both less influence on the dust removal. The numerical simulation of the optimal method showed that it outperformed on dust removal than the actual working conditions. This research provided a theoretical basis and direction for optimizing the performance of a ventilation and dust removal system. Image, graphical abstract [ABSTRACT FROM AUTHOR]

In order to study the characteristics of soil of pore pressure under subway moving loads, this paper calculated and analyzed the influence ratio of accumulated pore pressure with confining pressure, dynamic stress amplitude, frequency and vibration frequency by dynamic triaxial tests based on orthogonal experimental design. The results show that the water content of soil is larger, and the accumulated pore pressure is higher. The accumulated pore pressure is greatly influenced by single factor, and the greatest influence is dynamic stress. The second is confining pressure and frequency, and the last is vibration times. The coupling of confining pressure and vibration times, frequency and vibration times can be ignored to accumulated pore pressure, and the others can not be ignored. The coupling of factors is remarkable to accumulated pore pressure than the single factor under certain conditions. For example, the coupling of factors between dynamic stress amplitude and confining pressure is greater than that of vibration frequency on accumulated pore pressure. [ABSTRACT FROM AUTHOR]

Mesoporous bioactive glasses (MBGs) are considered to be outstanding bone-repairing materials. MBGs were prepared by a two-step acid-catalyzed self-assembly (TSACSA) process combined with a hydrothermal reaction. To synthesize the optimized texture organization, an orthogonal experiment was designed under the same conditions (acid concentration, calcination temperature, hydrothermal time and hydrothermal temperature). The MBGs were characterized by N 2 adsorption analysis, SAXS and TEM. The in vitro bioactivity was investigated by XRD and FTIR after soaking in SBF for 3 and 6 h. The results illustrated that the calcination temperature was the key factor affecting pore volume and the specific surface area. The hydrothermal temperature had the greatest impact on pore size. Compared with MBG prior to hydrothermal treatment, MBG after hydrothermal treatment displays more highly ordered mesopores and more uniform cylindrical pores. In the in vitro bioactivity test, synthesized MBG presents hydroxyapatite (HA) mineralization activity within a short time. The optimal conditions of the synthetic process were 1 mol L−1 hydrochloride acid, a hydrothermal reaction temperature of 120 °C for 24 h and a calcination temperature of 500 °C. This resulted in a large pore volume (1.22 ± 0.06 cm3 g−1) and high specific surface (679 ± 32 m2 g−1). • MBGs were prepared by TSACSA process method combined with hydrothermal reaction. • The MBGs showed large pore volume and high specific surface. • Pore size is effectively fine-tuned by adjusting hydrothermal temperature. • After extracting template surface area rises with calcination temperature decreasing. • Acid concentration as a catalyst has weak impact on pore volume and pore size. [ABSTRACT FROM AUTHOR]

Summary: Operating parameters have a huge impact on the output characteristics of a proton exchange membrane fuel cell stack. In this study, to optimize the performance of proton exchange membrane fuel cell stack, 4 sets of operating parameters, which include working temperature, cathode stoichiometric, relative humidity, and backpressure, were optimized by means of the orthogonal experimental design. The experiment was developed with the help of 4‐factor and 3‐level orthogonal table. Nine orthogonal experiments were performed, and the polarization curve, local current density distribution, and electrochemical impedance spectroscopy of each experiment were obtained. It is observed that cathode stoichiometric and working temperature have much stronger effects on the output voltage and output consistency of stack than that of relative humidity and backpressure. Using comprehensive equilibrium method, the optimized combination of each parameter was achieved as follows: the working temperature was 75°C, cathode stoichiometric was 2.5, relative humidity was 50%, and backpressure was 1 bar. The on‐site test result showed that when the cathode stoichiometric was low, and some part of the stack would be in a starvation condition and when the temperature was low, it might cause mass transfer problems. [ABSTRACT FROM AUTHOR]

Organic-sandy soils that contain abundant organic matters are widely encountered in estuarine cities. Due to the existence of organic matters, the strength and stiffness of this type of soil are significantly low. As a result, various geotechnical engineering problems such as difficulties in piling and constructing embankments and a lack of strength in poured concrete may occur in many estuarine sites; ground improvement such as cement treatment to this type of soils is needed. In this study, laboratory tests were perfonned to investigate the compressive strength of organic-sandy soil reinforced with primarily cement, in which the influences of several factors, namely types of cement and additional stabilizing agent, cement content, and watercement ratio, were investigated and the orthogonal experimental design scheme was adopted. Based on the test results, an optimal permutation of these influencing factors is suggested for the reinforcement of organic-sandy soils, which can provide a useful reference for the relevant engineering practice. [ABSTRACT FROM AUTHOR]

Three-dimensional printing (3D printing) technology based on slurry extrusion makes it possible to realize rapid manufacture of personalized, refined and complex ceramic products. The ceramic slurry for extrusion molding which is affected by various factors requires excellent extrusion properties and shape retention capacity. In this paper, the methods of orthogonal experiment design (OED) and back propagation artificial neural networks (BP ANNs) were combined to solve multi-objective and multi-factor problems caused by the preparation of alumina slurry. Through the combined model, the relationship between extrusion parameters and influencing factors of the slurry was obtained. The predicted optimal values were consistent with the experimental results, which proves the validity of the model. Alumina slurry suitable for 3D printing with excellent extrusion and shape retention properties was successfully prepared. The method is also applicable to the study of other multi-objective and multi-factor ceramic materials. [ABSTRACT FROM AUTHOR]

Object-based shadow detection in urban areas is an important topic in very high resolution remote sensing image processing. Multi-resolution segmentation (MRS) is an effective segmentation method, and is used for object-based shadow detection. However, several input parameters within MRS may result in unstable performance for final shadow detection; thus, the evaluation and optimization for the parameters upon the final shadow detection accuracy cannot be overlooked. In this paper, the three parameters in MRS (scales, weight of colourwcolorand weight of compactnesswcompact) upon the final result of a recently proposed method, object-based shadow detection with Dempster–Shafer theory, were evaluated and optimized by sensitivity analysis and Taguchi’s method with three experimental data. Experiments show that scalesis the most sensitive parameter among the three parameters within MRS. More importantly, according to the Taguchi’s method theory, there is a very significant interaction effect betweensandwcolor, which cannot be overlooked. The shadow detection accuracy yielded by the optimum parameter combination in consideration of the interaction effect is higher than that only optimized by covering the main effect of single parameter in most cases. [ABSTRACT FROM AUTHOR]

Oil shale is a kind of potential alternative energy source for petroleum and has attracted the attention of energy researchers all over the world. Borehole hydraulic mining has more prominent advantages than both conventional open-pit mining and underground mining. It is very important to attempt to use the borehole hydraulic mining method to exploit underground oil shale. The nozzle is the key component of borehole hydraulic mining and reasonable mining parameters are also crucial in exploiting underground oil shale efficiently. The straight cone nozzle and the oil shale of Huadian area will be taken as the research objects. The self-developed, multifunctional, experimental device can test both the jet's performance as well as the breaking of oil shale by the high-pressure water jet using the straight cone nozzle and varying structural parameters. Comprehensive analysis of the results of an orthogonal experimental design, including range analysis and variance analysis, demonstrate the optimal structural parameters of a straight cone nozzle as follows: the outlet diameter is 4 mm, the length to diameter ratio is 2.5, and the contraction angle is 60°. In addition, in order to maximize the efficiency of borehole hydraulic mining for Huadian oil shale, the non-submerged jet should be placed parallel to the oil shale bedding. These results can provide scientific and valuable references for borehole hydraulic mining of oil shale. [ABSTRACT FROM AUTHOR]