Orthogonal Test Design Research Articles

The optimum proportion of hygroscopic properties of modified soil composites based on orthogonal test method

Most published works have considered the influence of a single factor on the thermal or hygroscopic properties of the modified soil materials, but few studies have focused on the influence of multi-factor. Therefore, an L9 (34) orthogonal array test design was adopted in this study to investigate the effects of cement, lime, fly ash, and moisture on the hygroscopic properties of modified soil composites. They were chosen as chemical additives because they are the most common and widely used industrial building materials in the construction of modern buildings. Based on results from range analysis and mean square deviation analysis, the important order of the four factors on the hygroscopic properties was achieved, then the optimum proportion is found. The results show that cement has the most obvious effect on the equilibrium moisture content in 52.89% relative humidity (RH) among the four factors, and fly ash flow is second, moisture content has a minimal effect. By optimizing the parameters, when the cement content was 7%, lime content was 5%, fly ash content was 4% and the moisture content was 10%, the highest average equilibrium moisture content of 1.625% was obtained. The optimized modified soil composites have excellent hygroscopic properties and compressive strength meets the corresponding safety requirements, so it has potential for application and development in the field of soil architecture.

An experimental investigation of abrasive suspension flow machining of injector nozzle based on orthogonal test design

The application of abrasive suspension flow machining (ASFM) to grind a diesel engine injector nozzle is discussed in this paper. The purpose is to remove the sharp corners of the spray holes and improve the fuel flow through the injector nozzle. The proposed method adopts one-way flow to grind the spray holes for high-efficiency production. Compared with traditional reciprocating flow grinding methods using abrasive pastes, the viscosity of slurry and abrasive concentration of ASFM are lower, better for more smooth flow. To achieve a good grinding performance, it is important to determine proper viscosity and concentration. For this purpose, a design of experiments (DoE) method is adopted. In this paper, an orthogonal test method is combined with a non-linear regression method to optimize the process parameters. Through a range analysis on experiment results, the optimal process conditions in terms of the grinding efficiency and the grinding quality are determined. Experiment verifications show that the optimized process parameters can significantly improve the ASFM grinding efficiency and grinding quality.

Orthogonal Test Design for Optimization of the Extraction of Polysaccharides from Inonotus cuticularis and Their Antioxidant Activities.

Medical fungi polysaccharides belong to a very important species of biological macromolecules, which are the basic substances that effectively maintain and ensure the normal operation of biological life activities. However, research on extraction and biological activity of Inonotus cuticularis polysaccharides has never been reported. In this study, the optimum yield of Inonotus cuticularis polysaccharides was determined by the orthogonal experimental design. The highest yield of 3.10±0.06 % was obtained with extraction temperature of 80 °C, extraction time of 150 min, and water to raw material ratio of 30 mL/g and repeated twice. After deproteinization for 5 times, the protein removal rate reached 70.10±1.75 %, and the content of polysaccharides and protein were 46.64 and 0.42 %. Infrared spectrometer indicated that Inonotus cuticularis polysaccharides are typical β-pyranose with characteristic peaks of polysaccharides. Subsequently, the activities of scavenging free radicals for the deproteinated polysaccharides were studied. When the concentration of Inonotus cuticularis polysaccharides was 0.3 mg/mL, the scavenging activities of the sample on DPPH. , . OH, ABTS.+ and O2 .- reached 83.67±0.27, 65.21±4.82, 43.45±1.36 and 80.28±2.30 %, respectively, and the reducing power reached 0.46±0.01. The IC50 values scavenging DPPH. , . OH, ABTS.+ and O2 .- were 0.139±0.13, 0.162±0.14, 0.317±0.30 and 0.121±0.10 mg/mL, respectively. Results showed that Inonotus cuticularis polysaccharides present potential stronger antioxidant activities, especially .OH scavenging activity and reducing power. Experimental results could provide research basis of Inonotus cuticularis polysaccharides for further exploitation and utilization.

Prediction of compression and deformation behaviours of gangue backfill materials under multi-factor coupling effects for strata control and pollution reduction.

Coal mining causes serious ecological and environmental damage. The crushed gangue is backfilled into underground goaf, which not only inhibits mining-induced subsidence but also reduces accumulation of waste on the ground: however, the effects of backfilling with gangue backfill materials in goaf are affected by a combination of multiple factors. To predict compression-induced deformation (CID) of gangue backfill materials, key factors influencing compression and deformation characteristics of gangue backfill materials in an underground confined space (lithology, particle size distribution, lateral stress and lateral loading times) were determined. Moreover, two key factors, namely, lithology and particle size distribution of gangue backfill materials, were quantified. Based on orthogonal test design, the compression characteristics of gangue backfill materials were measured under different stress levels and coupling effects of the four key factors by utilising a self-made bidirectional loading test system for bulk materials. Furthermore, through regression, the relationships of the four key factors and axial strain were determined as well as undetermined parameters in axial stress-axial strain equations and axial stress. Based on this, an equation for predicting stress-strain relationship during compression-induced deformation of gangue backfill materials under multi-factor coupling effects was established. Comparison with the orthogonal test results shows that this equation can predict compression-induced deformation of gangue backfill materials in goaf. This is beneficial to providing a basis for predicting strata movement and surface subsidence and guidance for designing backfilling process, thus protecting the surface environment.

Effects of surface microstructure and molding parameters on injection bonding strength of polyphenylenesulphide-aluminum alloy

The direct injection molding process of PPS-aluminum alloy composite parts under vacuum condition was conducted and the processing parameters were optimized through the numerical simulation and orthogonal test design. The effect of surface microstructure of the aluminum alloy splines and injection molding processing parameters on the bonding strength of the composite parts were discussed. The results show that the bonding strength of the composite parts increases with not only the increase in the diameter and quantity of the microscopic pores and also the surface roughness of the aluminum alloy splines. The bonding strength can also been improved under a higher vacuum. The bonding strength is highly correlated to the micromechanical interlocking structure formed by the PPS embedding into the rough surface of the aluminum alloy splines.

Economic analysis of expressway building envelope in cold area based on RSM

The DeST-c energy consumption simulation software was used to build the building model based on the toll station and service area building in expressway of Zhangjiakou in the cold area, simulates and calculates the impact of single factor on energy consumption, and carries out economic analysis based on life cycle theory to determine the level of influencing factors. Finally, the BBD test design method and the orthogonal test design method were used to design the test scheme respectively and the economic analysis of the comprehensive thermal performance of the envelope structure, and the optimal energy saving scheme of the comprehensive thermal performance of the building envelope in the cold area was obtained.

Lightweight Design of Automotive Front End Material-Structure Based on Frontal Collision

<div class="section abstract"><div class="htmlview paragraph">The front end structure is an important role in protecting the vehicle and passengers from harm during the collision. Increasing its protective capacity can be achieved by increasing the thickness or replacing high-strength materials. Most of the current research is analyzed separately from these two aspects. This paper proposes a multi-objective optimization method based on weighting factor analysis, which combines material and thickness selection. Firstly, the optimized components are determined based on the 100% frontal collision simulation results. Secondly, six thicknesses and two materials of the front part of the vehicle body are selected as design variables to construct an orthogonal test design. In this paper, a weight-based multi-factor optimization method is used to numerically analyze the response results obtained by orthogonal experiments. Analyze the impact of each factor on the optimization goal to select the most reliable optimization. This optimization method can select the best material and component thickness combination scheme. The results show that the mass of the selected parts are reduced by 16.5%; the total energy absorption is increased by 5.2%; the intrusion in the dash is reduced by 8.9%; and the peak acceleration of the B-pillar is reduced by 39.2%.The material-structure integration optimization method is an effective method to solve the contradiction between lightweight and crashworthiness.</div></div>

Preparation of a new low-cost substrate prepared from drinking water treatment sludge (DWTS)/bentonite/zeolite/fly ash for rapid phosphorus removal in constructed wetlands

With the increase of tap water demand and treatment volume, the by-product of the water supply plant-drinking water treatment sludge (DWTS) is increasing, and its final disposal urgently needs to be reasonably resolved. Therefore, the reuse of DWTS can not only solve the “waste” problem but also generate favorable economic benefits. This is the first study to use DWTS to prepare a regular, industrialized and efficient DWTS composite substrate (DWTSCS) for phosphorus removal in constructed wetlands by using DWTS as the main material and bentonite, zeolite and fly ash as the additive. The optimal weight ratio of DWTSCS was determined by combining orthogonal test and mixture design experiments: cement = 22.32%, DWTS = 51.62%, bentonite = 13.03%, zeolite = 4.34%, fly ash = 8.69%. The microstructure and phase analysis were performed using SEM and XRD. The static adsorption experiments showed that the adsorption behavior of DWTSCS to phosphorus conforms to a quasi-second-order kinetic model and the adsorption process can be simulated using Langmuir and Freundlich models. The maximum adsorption capacity of phosphorus by DWTSCS was calculated as 40 mg/g, and the adsorption of phosphorus with the DWTSCS was a spontaneous exothermic process. Under acidic conditions, it was favorable for DWTSCS to adsorbed phosphorus. The concentration of adsorbed phosphorus with the DWTSCS ranged from 0.5 mg/L to 0.2 mg/L. This research provides a basis for the application of DWTSCSs in constructed wetlands.

Seismic Stability Analysis of Loess Landslide Based on Orthogonal Test

A numerical model of a loess landslide is established by using numerical simulation method to simulate the stability of the loess landslide under earthquake load. The results show that the loess landslide is stable before the earthquake and instable under the earthquake. The horizontal displacement and shear strain increment of the front part of the sliding slope increase obviously under the earthquake. At the same time, the sensitivity analysis of the seismic stability of the loess landslide is carried out by using the orthogonal test design method. The results show that the seismic action is the second factor to the internal friction angle of the sliding zone soil. With the increase of the seismic intensity, the decrease trend of the stability coefficient increases.

Random-interval hybrid reliability analysis for fan performance in the presence of epistemic uncertainty

With the aim of reducing fan performance failure, an effective method of fan reliability analysis based on a hybrid uncertainty model was investigated using a combination of orthogonal test design, an approximation model, and computational fluid dynamics (CFD) simulation and analysis technology. By introducing interval uncertainty, this method can effectively solve the problem of quantifying model uncertainty owing to the lack of experimental samples and can greatly expand the applicability of reliability analysis technology in fluid machinery research. Random and interval uncertainty parameters were introduced to describe the fan system and a mixed random-interval reliability analysis model of fan performance was established based on the traditional first-order reliability analysis method. Using CFD analysis of the renormalization group (RNG) model, the flow, pressure, shaft power, efficiency, and other fan performance parameters were calculated, and the performance function was obtained. Owing to the low efficiency of the CFD calculation, the effective iterative algorithm of response surface to solve hybrid reliability model was studied, and the failure probability interval of fan performance was calculated. The method was used to study the fan performance of a rail transit train, and the failure probability, reliability index, and performance parameter sensitivity and uncertainty were analyzed. The influence of parameter uncertainty on system reliability was determined, and the engineering measures necessary to improve the fan’s performance reliability were proposed.

Numerical Simulation of the Influence of Geometric Configurations on Pressure Difference in the Intraventricular Tunnel.

ObjectiveThe geometric configuration of the intraventricular tunnel is related to the re-intervention of left ventricular outflow tract stenosis after double outlet right ventricle (DORV) correction. Hemodynamic simulation was performed in order to study the influence of the geometric configuration of the IVT on the pressure difference.MethodsCT images of DORV were processed to reconstruct 3D models of left and right ventricular flow chambers and aortic valve orifice, and then the size and relative position of the aortic valve orifice and ventricular septal defect were determined. Twenty five groups of the idealized models were established according to orthogonal test design and computational fluid dynamics method was applied to simulate hemodynamics. Three factors of geometric configuration were considered for the study of their influences on the pressure difference. The first factor is the distance between the ventricular septal defect and the plane of the aortic valve (DSA), the second factor is the ejection angle of blood from left ventricle flowing into the IVT (ALT), and the third factor is the turning radius of the IVT (RTT). SPSS software was employed to perform the orthogonal analysis. Additionally, twelve models with different turning radii were established for hemodynamic analysis, with the turning radii increasing from 0 mm with an interval of 1 mm, so as to study the influence of turning radius on pressure difference of IVT.ResultsThe analysis of variance showed that only the change of RTT had a significant effect on the pressure difference (P = 0 < 0.05), while the change of DSA and ALT had no significant effect on the pressure difference (P = 0.459 > 0.05, P = 0.263 > 0.05). The pressure difference decreases with the increase of RTT. When RTT reaches 6 mm, the pressure difference gradually remains unchanged with the increase of RTT, and the rate of change is less than 5%.ConclusionRTT in the IVT is the main factor affecting the pressure difference. A small RTT will lead to a large pressure difference in the IVT. When RTT increases to 6 mm, the pressure difference in the IVT remains nearly unchanged. When performing the right ventricular double outlet correction; the turning radius of the IVT should be about 6 mm to ensure relatively small pressure difference.

Strength properties of dredged soil at high water content treated with soda residue, carbide slag, and ground granulated blast furnace slag

In this study, three industry by-products, soda residue (SR), carbide slag (CS), and ground granulated blast furnace slag (GGBS), were used to stabilize dredged soil at high water content. Based on the orthogonal test design, unconfined compressive tests were conducted to analyze the strength of stabilized soil cured for 3, 7, and 28 days. The drying–wetting durability of the stabilized soil was also investigated. The results indicate that the increase in GGBS dosage can increase the unconfined compressive strength (UCS) of samples with an initial water content of 110%, and the optimum dosages of SR and CS were 35% and 6%, respectively. The order of effect of the factors for the 3-day UCS was SR > GGBS > CS, which changed to GGBS > CS > SR for the 7-day and 28-day UCS. The results of X-ray diffraction (XRD) and scanning electron microscopy (SEM) show that the main products of hydration in stabilized soil were ettringite, calcium chloroaluminate hydrates (Fs), and gismondite. The reaction involving SR, CS, GGBS, and soil minerals produced the above hydration products, which had the filling-in and cementation effects. In general, 5 cycles of drying–wetting had no adverse effect on the USC for dredged soil stabilized with SR-CS-GGBS mixtures. The results provide a theoretical basis and data support for the resource utilization of SR, CS, and GGBS as stabilizer for dredged soil at high water content.

Determination of delamination in drilling of carbon fiber reinforced carbon matrix composites/Al 6013-T651 stacks

Delamination at the hole entrance and exit during drilling of the FRPs composites adversely affects the hole surface quality and engineering properties of this material. In this study, delamination occurrence in hole entrance and exit during drilling of carbon fiber reinforced carbon matrix composite material (C/C) as stacked on aluminium plate was investigated. According to Taguchi L9(33) orthogonal array test design experiments were conducted for each of with 90°-118° and 135° point angle uncoated, TiN and TiAlN coated HSS drills. Three different cutting speeds (100-125-150 m/min) and feed rate (0.1-0.2-0.3 mm/rev) values were used as cutting parameters. The study showed that uncoated drills caused less delamination than TiN and TiAlN coated HSS drills and optimum cutting parameters were determined as the high cutting speed, low feed rate and drill point angle combination (V:150 m/min, f: 0.1 mm/rev, θ: 90°). With ANOVA (Analysis of variance), the most effective parameter on hole entrance and exit delamination of the composite material was determined as the feed rate. First degree mathematical models were developed for entrance and exit delamination factors of each cutting tool using regression analysis. According to the obtained data, optimization, mathematical models and experimental test results were found very coherent.

Penetration of the blood-brain barrier and the anti-tumour effect of a novel PLGA-lysoGM1/DOX micelle drug delivery system.

Effective treatment of glioma and other central nervous system (CNS) diseases is hindered by the presence of the blood-brain barrier (BBB). A novel nano-delivery vehicle system composed of PLGA-lysoGM1/DOX micelles was developed to cross the BBB for CNS treatment. We have shown that doxorubicin (DOX) as a model drug encapsulated in PLGA-lysoGM1 micelles can achieve up to 3.8% loading efficiency and 61.6% encapsulation efficiency by the orthogonal test design. Our in vitro experiments demonstrated that PLGA-lysoGM1/DOX micelles had a slow and sustainable drug release under physiological conditions and exhibited a high cellular uptake through the macropinocytosis and the autophagy/lysosomal pathways. In vivo experimental studies in zebrafish and mice confirmed that PLGA-lysoGM1/DOX micelles could cross the BBB and be specifically accumulated in the brain. Moreover, an excellent anti-glioma effect was observed in intracranial glioma-bearing rats. Therefore, PLGA-lysoGM1/DOX micelles not only effectively can cross the BBB, but our results also suggest that they have great potential for anti-glioma therapy and other central nervous system diseases.

Multi-Objective Topological Optimization of an Electric Truck Frame Based on Orthogonal Design and Analytic Hierarchy Process

The electric truck frame as a vital load-bearing component has aroused growing attentions due to its enormous potential in lightweight. However, few systematic studies have been performed on the multi-objective topological design of the frame attributable to its complexity on loading and conflicting objectives. This paper aims to develop a multi-objective topology optimization strategy of the electric truck frame based on the hybrid decision making method combining orthogonal test design (OTD) and analytic hierarchy process (AHP). The hybrid strategy is performed to obtain a new set of weight ratio combination from objective data and subjective judgment. The topological results show that the overall performance of the optimal frame is better than any of the methods applied alone. By comparing, it is found that the strength and stiffness of the optimal frame is higher than that of the original frame from the perspective of static conditions, and the low-order natural frequency of the optimal frame is significantly improved. It demonstrates that the proposed approach could be as an effective tool for multi-objective topology optimization of the electric truck frame in seeking lightweight and comprehensive mechanical performance. The hybrid strategy might be expected to provide some guidance for more complicated engineering problems.

PERFORMANCE OPTIMIZATION OF PARALLEL CONNECTED RANQUE-HILSCH VORTEX TUBES WITH CARBON DIOXIDE AND AIR USING THE TAGUCHI METHOD

In this study, the influence of the parameters affecting the vortex tube performance was investigated using the Taguchi method for a system of parallel connected Ranque-Hilsch vortex tubes (RHVT) comprising two counterflow vortex tubes. The RHVT performance parameter is the temperature difference (ΔT) between the hot flow outlet and the cold flow outlet of the RHVT. For this study, the parameters called control factors are four as vortex tube inlet pressure, working fluid type, number of nozzles, and nozzle material. Two and six nozzles made of polyamide and brass were used and CO2 and air were used as a working fluid. The quantity ΔT was optimized according to the Taguchi L16 orthogonal array test design for eight levels of RHVT system inlet pressure in the range of 150-500 kPa with the specified parameters and levels. Control experiments were performed, and optimization results were obtained. The most important control factor affecting the performance of parallel connected RHVT system was determined as a working fluid inlet pressure according to the Taguchi method, and the percentage effect of it was calculated as 74.85%. The effectiveness of nozzle number, nozzle material, and working fluid type parameters are the factors following the inlet pressure, respectively.

ECT Sensor Simulation and Fuzzy Optimization Design Based on Multi Index Orthogonal Experiment

Electrical Capacitance Tomography (ECT) is a non-destructive visual measurement technology, which is mainly used in the detection of two-phase flow and multi-phase flow. In this paper, according to the characteristics of the non-uniform sensitive field and the low sensitivity of the central area of the capacitance sensor, the finite element simulation analysis in COMSOL and the orthogonal test design method are introduced to optimize the structural parameters of the capacitance sensor, including the geometric size of the electrode plate, the height of the shield, the thickness of the pipe wall and its relative permittivity. In view of the analytical relationship between the structural parameters and the performance optimization indexes of the capacitance sensor, and there are many parameters need to be optimized, this paper proposes a fuzzy comprehensive satisfaction index (FCSI) as the evaluation standard, and on this basis carries out the optimization design of the structural parameters of the capacitance sensor. The simulation results show that the fuzzy optimization design based on multi index orthogonal experiment makes the capacitance sensor meet the requirements of uniform sensitive field distribution and high reconstruction image quality at the same time.

Preparation of Sustained-Release Agent of Long-acting Chlorine Dioxide

In order to develop a sustained-release solid chlorine dioxide preservative with controlled concentration and effective sterilization time,the effects of different kinds of activators,gels and chloride salts on the concentration and slow release period of chlorine dioxide gas were investigated. The formulation was optimized by L9(34)orthogonal test design method. The optimized preservative by scanning electron microscopy was observed. The results showed that the use of EDTA as an activator made effective sterilize time over 20%. When sodium carboxymethyl cellulose(CMC)was used as the gel,the sustained-release rate of chlorine dioxide gas was the smallest and the effective sterilization time was longer. The using of NaCl as a chloride salt provided a micro-electric field environment while passivating the reactants. When the mass ratio of CMC,EDTA and NaCl was 14:1:5,the effective sterilization time(concentration of 1~50 mg/kg)of the sustained-release preservative reached 28 d. The internal structure of the preservative agent was observed under the electron microscope. After the formulation optimization,the internal structure of the sustained-release agent was a dense microporous network structure with a tight arrangement of particles and certain rules. The chlorine dioxide gas generated by the reaction was stored in the microporous structure of the sustained-release agent and released slowly.

THE INFLUENCE OF BRAIN TISSUE MATERIAL PARAMETERS ON THE RESPONSE OF DYNAMIC CHARACTERISTICS BASED ON FINITE ELEMENT MODEL

Aiming at the uncertainty of material parameters of human brain tissue, the influence of tissue material performance sensitivity on frequency and mode shape under free vibration is studied. In this paper, the 50th percentile finite element (FE) model of human head and neck with detailed anatomical characteristics has been chosen as the research object, the parameters of skull, cerebrospinal fluid (CSF) and brain tissue materials with high sensitivity are analyzed by orthogonal test design and variance analysis. The results show that the natural frequencies of Group 7, Group 8 and Group 9 are all around 230[Formula: see text]Hz, which are basically consistent with the initial parameter of 229.18[Formula: see text]Hz, and the intracranial displacements of the three groups are also concentrated on the lateral nasal cartilage. The main reason is that the Young’s modulus of the skull used in three groups of experiments is 9780[Formula: see text]Mpa, which is close to the initial parameter of 8000[Formula: see text]Mpa. It indicates that the material parameter of the skull has the greatest influence on the dynamic characteristics of human head and neck, followed by the CSF and brain tissue. This study provides an effective method for vehicle safety and head and neck injury protection, and supplies a reference for FE analysis of head collision damage.

Production of biochar from waste sludge/leaf for fast and efficient removal of diclofenac

Sludge and leaf are two kinds of typical solid wastes with huge production. How to effectively treat sludge/leaf thus becomes a hot issue and needs to be solved at present. This study aims to develop the resource recycling technology in converting waste sludge/leaf to biochar material for diclofenac (DFC) removal. Through the orthogonal test design, the effects of pyrolysis temperature, sludge/leaf ratio, and pyrolysis time were systematically investigated. Under the conditions of pyrolysis temperature 200 °C, sludge/leaf ratio 1:3, and pyrolysis time 1 h, the optimized biochar was simply produced where the key indicators iodine value and biochar yield reached 287.81 mg/g and 85.15%, respectively. Adsorption results revealed that DFC was rapidly and efficiently adsorbed by the recycled sludge/leaf biochar at the conditions of 25 °C, initial DFC concentration of 10 mg/L, solution volume of 8 mL, and biochar dosage of 0.005 g. With the maximum adsorption capacity of 877 mg/g, the DFC adsorption process was described well by pseudo-second order kinetics and Temkin isotherm model. Furthermore, after activation by 9% HCl solution, the specific surface area of the biochar increased from 3.30 to 4.17 m2/g, indicating that activated biochar had more sites for DFC adsorption. That was also confirmed by SEM images which showed more porous and rough characteristics on the surface structure of biochar. The data displayed a green environmental technique in converting waste sludge/leaf to useful biochar adsorbent for rapid and efficient DFC removal.