Orthogonal Surface Research Articles

Optimization of Operating Parameters for Straw Returning Machine Based on Vibration Characteristic Analysis

For the mechanized technical mode of total wheat straw returning to field, there are problems such as large vibration during the operation of the straw returning machine that, in turn, affect the effect of stubble breaking. This study took the Tongtian 1-JHY-220 straw returning machine as the research object to conduct field experiments, with wheat stubble height, forward velocity, and PTO speed as experimental parameters. And the vibration characteristics at different positions of the machine and the final stubble breaking rate were used as evaluation indicators. Combined with the orthogonal experiment and response surface analysis method, this article analyzes and discusses the influence of various parameters on vibration characteristics and operational effectiveness. The results show that PTO speed and wheat stubble height were the main factors affecting the vibration and operation quality of the straw returning machine. Low PTO speed and high stubble height can improve the stubble breaking rate of the straw returning machine and reduce its operation vibration. Furthermore, the multi-objective optimization results show that when the forward velocity in the range of 8.5–9 km/h, the PTO speed is 540 r/min, and the stubble height is in the range of 200–250 mm, the stubble breaking rate of the straw returning machine is greater than 86%. At this time, the total vibration of the straw returning machine and tractor rear axle is relatively small. This study can lay a foundation for further studying the impact of the vibration of the straw returning machine on the stubble breaking effect and provide a reference for the preparation of high-quality seedbed under conservation tillage.

Combined fluid and ferrofluid buoyancy force, heat absorption and non linear ferro-viscosity effects on ferro- hydrodynamics fluid flow in orthogonal porous surface

Mixed convection incompressible ferro-hydrodynamic (FHD) boundary layer fluid flow on vertical porous curvilinear orthogonal surfaces is examined in our present study in presence of combined fluid and ferro-fluid buoyancy force, nonlinear ferro-viscosity parameter, and heat absorption/generation effects. Design/Methodology/Approach: Types of Prandtl momentum and thermal boundary layer partial differential equations in a curvilinear system are converted into non-dimensional ordinary nonlinear differential equations (ODE) by introducing dimensionless velocities, temperature functions and similarity variable. Missing initial conditions are found by shooting method and solving the system of nonlinear ODEs by Runge-Kutta integration scheme of order six. With the help of MATLAB, the numerical solutions are graphically displayed in the forms of primary velocity profile, secondary velocity profile, and temperature profile. Three types of magnetic nano-ferrofluid are considered such as water-based ferrofluid (Taiho W-40), Hydrocarbon based ferrofluid (EMG-901) and kerosene-based ferrofluid (C1-20B) whose Prandtl numbers are 44.3, 79.3 and 128 respectively shown in Table 1. For kerosene based ferro-fluid, Table 3 presents the coefficient of skin friction and heat flux. Finding: The effects of combined fluid and ferrofluid buoyancy forces, nonlinear ferro-viscosity parameter, suction/injection, and heat absorption/generation parameters on the velocity and temperature profiles are investigated. Our physical interest is to calculate the local shearing stresses and the local heat flux at the surface. Finally, we have made comparisons of the results which are highlighted the validity of our numerical calculations adopted for the presence study.

Structure optimization for the discharge arm of the self-propelled forage harvester based on CFD-DEM

To optimize the structure of the discharge arm of the self-propelled harvester and improve the harvesting efficiency to reduce the loss, we first established a mathematical model of the gas-solid two-phase of the forage in the unloading process. Next, we revealed the flow characteristics of forage and the influence of key structures of the discharge arm using the CFD-DEM. Then, we optimized the key structural parameters of the discharge arm using the orthogonal test and response surface method. Finally, we carried out the simulation and field experiment on the forage conveying performance of the discharge arm. The experimental results show that the maximum conveying distance of the new discharge arm is more than 27 m, significantly reducing the spraying loss and improving the harvesting efficiency. Our research findings provide a new reference for optimizing the agricultural material conveying machines and exploring the movement characteristics of agricultural materials in different pipelines.

Immunojanus Particles for low-volume and isolation-free unlabeled characterization of small Extracellular Vesicle in biofluids: Characterization of disease type by surface marker profiling.

Small extracellular vesicles (sEVs) are vital for cellular communication and serve as critical biomarker carriers for diseases such as cancer. However, quantifying and profiling sEV surface markers presents significant challenges due to the low concentration of specific sEV-bound proteins and interference by more abundant dispersed proteins. This paper presents Immunojanus Particles (IJPs), a new method that enables the direct detection of sEVs in less than an hour without isolation. The design of IJPs incorporates fluorescent and non-fluorescent halves, utilizing rotational Brownian motion to detect captured sEVs through the change in the blinking rate, without interference from the smaller dispersed proteins. We demonstrate a detection limit of 2E5 sEVs/mL with low sample volumes and the capability to characterize sEVs directly from plasma, serum, cell culture media, and urine. In a small pilot study involving 87 subjects, including individuals with colorectal cancer, pancreatic ductal adenocarcinoma, glioblastoma, Alzheimer's disease, and healthy controls, our method accurately identified the type of disease with high 0.90-0.99 AUC in a blind setting. Compared with an orthogonal ultracentrifugation plus surface plasmon resonance (UC+SPR) method that requires about 24 hours, the sensitivity and dynamic range of IJP are better by 2 logs.

Comparative study of the experimentally observed and GAN-generated 3D microstructures in dual-phase steels

ABSTRACT In a deep-learning-based algorithm, generative adversarial networks can generate images similar to an input. Using this algorithm, an artificial three-dimensional (3D) microstructure can be reproduced from two-dimensional images. Although the generated 3D microstructure has a similar appearance, its reproducibility should be examined for practical applications. This study used an automated serial sectioning technique to compare the 3D microstructures of two dual-phase steels generated from three orthogonal surface images with their corresponding observed 3D microstructures. The mechanical behaviors were examined using the finite element analysis method for the representative volume element, in which finite element models of microstructures were directly constructed from the 3D voxel data using a voxel coarsening approach. The macroscopic material responses of the generated microstructures captured the anisotropy caused by the microscopic morphology. However, these responses did not quantitatively align with those of the observed microstructures owing to inaccuracies in reproducing the volume fraction of the ferrite/martensite phase. Additionally, the generation algorithm struggled to replicate the microscopic morphology, particularly in cases with a low volume fraction of the martensite phase where the martensite connectivity was not discernible from the input images. The results demonstrate the limitations of the generation algorithm and the necessity for 3D observations.

Novel development of laser synthesized double orthogonal PSi surface NH3 gas sensors

Novel development of laser synthesized double orthogonal PSi surface NH3 gas sensors

Process-Induced Crystal Surface Anisotropy and the Impact on the Powder Properties of Odanacatib.

Crystalline active pharmaceutical ingredients with comparable size and surface area can demonstrate surface anisotropy induced during crystallization or downstream unit operations such as milling. To the extent that varying surface properties impacts bulk powder properties, the final drug product performance such as stability, dissolution rates, flowability, and dispersibility can be predicted by understanding surface properties such as surface chemistry, energetics, and wettability. Here, we investigate the surface properties of different batches of Odanacatib prepared through either jet milling or fast precipitation from various solvent systems, all of which meet the particle size specification established to ensure equivalent biopharmaceutical performance. This work highlights the use of orthogonal surface techniques such as Inverse Gas Chromatography (IGC), Brunauer-Emmett-Teller (BET) surface area, contact angle, and X-ray Photoelectron Spectroscopy (XPS) to demonstrate the effect of processing history on particle surface properties to explain differences in bulk powder properties.

Influence Factors of Pressure Swing Adsorption for Oxygen Production by the Orthogonal Method and the Response Surface Method

Adsorption pressure is one of the important factors affecting oxygen production in the process of pressure swing adsorption oxygen production. Three important factors, namely, the adsorption period, pressure equalisation time, and outlet flow rate, determine the variation in the adsorption pressure. In this study, the effects of the adsorption period, pressure equalisation time, and outlet flow rate on oxygen concentration were investigated through orthogonal experiments and response surface analysis. The experiments verified that three factors including the adsorption period, pressure equalisation time, and outlet flow rate have optimal values in the oxygen production process. Response surface analysis showed that the adsorption period had the greatest effect on the oxygen concentration, followed by the equalisation time, and the outlet flow rate had the least effect. The optimum process conditions are an adsorption time of 7.88 s, a pressure equalisation time of 0.9 s, an outlet flow rate of 2.31 L/min, and an oxygen concentration of 96.7%.

Preparation and Experimental Research of Temperature Sensitive Expansion Gel Material for Fire Prevention and Extinguishing in Coal Mines

ABSTRACT In order to solve the problems of high viscosity at room temperature, easy dehydration and shrinkage of phase change gel, and poor plugging effect of traditional mine gel, a new type of temperature-sensitive expansion gel was developed by using hydroxypropyl methyl cellulose, chitosan, guar gum and sodium bicarbonate as raw materials, using orthogonal test and response surface analysis. The structural characterization, characteristics, fire prevention, and extinguishing performance of the temperature-sensitive expansion gel were tested. The experimental results show that the optimal ratio of temperature-sensitive swelling gel is 0.75 wt % chitosan, 0.5 wt % acetic acid, 2.5 wt % hydroxypropyl methyl cellulose, 0.4 wt % sodium bicarbonate, and 0.15 wt % guar gum. The phase transition temperature (LCST) of this ratio is 67°C. After standing at room temperature for 6 h, the gel viscosity is 5852 mpa·s, the expansion ratio is 0.846, and the strength is 319.525 N/m2. During the heating process of the coal sample after adding the temperature-sensitive expansion gel, the gel will undergo phase change and expansion in the high-temperature area of the coal, and the viscosity will increase. It can stay in the high-temperature area, wrap the coal block, and isolate the oxygen from entering, thus effectively inhibiting the coal spontaneous combustion process. In addition, the gel also produces inert gas carbon dioxide, which effectively suffocates the flame. Therefore, compared with the conventional inhibitor solution, the temperature-sensitive expansion gel has better fire extinguishing effect.

Numerical analysis and process optimization of electron beam melting for superalloys

This study aims to determine the optimal parameters for the electron beam melting process by employing a modified transient three-dimensional thermal model. The validity of the thermal model is confirmed through experimental results. Moreover, the proposed method establishes mathematical relationships between the resulting molten pool temperature and process parameters. A broader range of process parameters for a new Ni–Co-based superalloy was achieved by investigating the effects of scanning velocities (10–100 mm/s), scanning radius (20–60 mm), and melting mass (1500–3100 g) on temperature at various electron beam power levels (10–30 kW). Regression models were established between scanning velocities-temperature, and scanning radius-temperature under different electron beam power levels. These models laid the foundation for real-time automatic control of molten pool temperature. Significantly, orthogonal experimental design and response surface method are employed to conduct a multi-objective optimization based on sixteen experiments and three parameters. The results of multi-objective optimization indicate that with a smelting mass of 1.5 kg, an electron beam power of 11 kW, a scanning radius of 60 mm, and a scanning velocity of 75 mm/s, the energy consumption is 34.95 kW h, and the theoretical mass loss of Ni element is 0.002 kg. The desirability is 91.2 %.

Experimental study of penetration of pre-cut free surface rock materials based on orthogonal tests and response surface testing methods

The parameters of the pre-cut kerf as the free surface on rock material have an important influence on the rock-breaking force of the disc cutter of TBM. The rock-breaking force of the disc cutter can be simplified as the normal penetration load of the metal indenter. In order to study the effect of the pre-cut free surface parameters on the penetration load, orthogonal experiments and response surface tests were carried out on sandstone and granite samples, and extreme deviation analysis and analysis of variance (ANOVA) were performed. The results showed that: (1) the order of priority of the factors affecting the penetration load of the disc cutter was Kerf depth > Kerf spacing > Kerf angle. (2) The fitting degree of the regression equation for the predicted values of the penetration loads of the sandstone and granite samples was R2 (Sandstone) = 0.9810 and R2 (Granite) = 0.9995, respectively, indicating that there was a good fit between the measured and predicted values of the penetration load of the two samples.

Compact and Highly Isolated Continuous Scanning Dual-Polarized Holographic Antenna Using a Pillbox Feeding Structure

In this paper, we propose a novel approach to realize a compact and highly isolated dual-polarized holographic antenna using a pillbox feeding structure. The proposed antenna feeds dual orthogonal surface waves with low distortion phase distribution and high isolation through a compact three-layer pillbox feeding structure. This antenna also consists of a shared aperture dual-polarized hologram pattern calculated to radiate the objective wave in the desired direction without increasing the antenna size. As a result, the proposed holographic antennas (HA) have a compact size and support forward-to-backward continuous scanning with minimal gain degradation. The simulated and measured results are in good agreement, validating the efficiency of the proposed antenna design, which has the ability to scan the beam direction from +18° to −25°, passing through the broadside within the frequency range of 21–27 GHz. Finally, the proposed antenna has a broadside gain of 18.5 dBi in each polarization and a gain variation of less than 2 dB within the operating bandwidth.

Characterization of dust emission during ore unloading and analysis of its influencing factors

Dry bulk terminals at ports generate dust in the process of ore loading / unloading and transfer, and these particulate matters disperse to the atmospheric environment causing pollution and endangering human health. This study focuses on the funnel unloading point of a portal crane at a port terminal, and the variation characteristics of dust emission under different mass flow rates, ambient wind speeds, and moisture contents are investigated. The microscopic features of ore powders, i.e., wetting time, contact angle, particle size, specific surface area and pore structure, as well as microscopic morphology, are also determined to explore the intrinsic mechanism between wettability, moisture content, and dust emission. The impact of mass flow rate, ambient wind speed, and moisture content on dust emission is evaluated by employing the orthogonal test range method and response surface method. The experimental data reveals that the dust at the unloading point is dominated by coarse particles of total suspended particulate (TSP), and increasing the moisture content effectively reduced the dust emissions, with a suppression efficiency of TSP > PM10 > PM2.5. The experimental results on the microscopic features of the ore powders indicate that the above difference is attributed to wettability, which weakens with diminishing particle diameter. It is also concluded that the wettability of Australian ore 1 is determined to be superior to bauxite 394. Therefore, Australian ore 1 exhibits an excellent dust suppression effect at a moisture content of 4% ∼ 5%, whereas bauxite 394 requires a moisture content of approximately 5% ∼ 7% to achieve the same dust suppression. By conducting the orthogonal test range method, the three factors on the dust emission, in descending order, are moisture content > ambient wind speed > mass flow rate. According to the response surface method, the optimal parameter combination is determined and the dust emission is minimized as 4.149 μg/s, which corresponds to 0.386 mg TSP/ton, with the conditions of mass flow rate 10.356 kg/s, ambient wind speed 4.289 m/s, moisture content 6.983%.

The Effects of Processing Parameters during the Wire Arc Additive Manufacturing of 308L Stainless Steel on the Formation of a Thin-Walled Structure.

Wire arc additive manufacturing (WAAM) excels in producing medium to large components with a high deposition rate. Process optimization is crucial for uniform, defect-free components. This research employs orthogonal experimental design and response surface methodology (RSM) to control TIG WAAM-ed 308L stainless steel components. Varied parameters, including tungsten electrode angle, welding current, and speed, target weld bead attributes. Analysis of variance (ANOVA) evaluates multi-processing parameter influence on weld bead formation. Comparison with experimental results confirms accurate modeling of the relationship between parameters and bead attributes. The study optimizes process parameters and swing to enhance dimensional accuracy in single-layer and multi-layer components, improving precision, quality, and accuracy in thin-walled structures.

Development of a composite microbial agent beneficial to improve drought and salt tolerance of Glycyrrhiza uralensis Fisch.

Plant growth is enhanced by microbiological agents. In order to develop environment friendly composite microbial agent that can also improve the salt and drought tolerance of plants, the orthogonal experiment and response surface methodology were used to screen nutrients and fermentation conditions of composite microbial agent, and pot experiment was conducted to validate the application effect of optimized and complex microbial agent. Compatibility test showed that G2 (Bacillus cereus) and G5 (Bacillus pumilus) did not show any inhibitory effect on each other’s growth in nutrient agar, moreover, in both the growth promotion characteristics and the seed germination tests, G2+G5 showed a synergistic effect. The process optimization results showed that the optimal carbon and nitrogen sources for the medium nutrients was maltose and yeast extract, and the optimal carbon-nitrogen ratio was 5:1; the optimal fermentation conditions included initial pH at 5.17, inoculation amount of 2.28%, liquid volume of 105.96 mL(250 mL)−1, and incubation temperature at 30.06℃. Pot experiment showed that application with composite microbial agent was able to increase antioxidant enzyme activities, ascorbat, proline content, and reduce reactive oxygen species accumulation and membrane peroxidation of G. uralensis seedlings under salt-drought stress. In conclusion, the composite G2+G5 agent possessed remarkable synergistic effect for improve plant tolerance to drought combined with salt stress, suggesting a noticeble practical potential in agricultural practice, and it can be used to develop newtype environment friendly microbial fertilizer.

Design and Test of Seed–Fertilizer Replenishment Device for Wheat Seeder

In view of existing problems, such as the seed and fertilizer supply link for wheat seeders still relying on manual installation and the lack of practical application equipment, a seed–fertilizer replenishment device based on the three-degree-of-freedom mechanical arm and screw conveying principle is designed using the seed box installation and supply as the operation scenario to replace the manual installation process. Combined with the requirements of the seed box replenishment operation, the key parameters of the replenishment robot arm and the screw conveyor auger are determined. Then, the kinematic model of the replenishment robot arm is established based on the modified D-H method, forward and inverse kinematics calculations are performed, and the workspace is analyzed using the Monte Carlo method. Based on this, the robotic arm task path is designed, the fifth-degree polynomial interpolation method is used to complete the trajectory planning, and MATLAB R2016a software is used to simulate the motion trajectories of each joint, verifying the feasibility of the trajectory planning solution. Finally, a prototype is trial-produced and quadratic regression orthogonal testing and response surface analyses are conducted to obtain the optimal working parameters of the replenishment device. The verification test shows that when the angular velocity of the lumbar joint of the replenishment device is 4°/s, the speed of screw conveyor is 90 r/min, and the angle of the big arm is 12°, the conveying loss rate is 3.98%, and the conveying efficiency is 0.833 kg/s. The relative errors with the theoretical optimal values are 4.2% and 2.4%, respectively, both less than 5%. The supply trajectory is reasonable, and the robot arm runs smoothly. This study can provide reference for the design of seed–fertilizer replenishment device for wheat seeders.

Study of the effect of factors on the wind-hydrogen system energy conversion

The combination of hydrogen and wind power can effectively reduce the waste of wind resources. This study explores a novel method to study the effect of operating conditions on equipment performance and system's the electric-hydrogen-electric conversion efficiency. The effect of the electrolyzer hydrogen production and fuel cell power generation under different operating conditions are studied. Orthogonal tests and Response surface methods are used to explore the influence of various factors on the electric-hydrogen-electric conversion efficiency. The results show that raising the electrolyzer's operating temperature, the system hydrogen production efficiency increases by 1.8 %. Raising the fuel cell's operating temperature, the fuel cell exergy efficiency increases by 2.2 %. The system electric-hydrogen-electric efficiency increased by 1.4 %. Raised gas pressure improves the reactant concentration. The system's electric-hydrogen-electric efficiency increased by 1.78 %. The influence degree of various factors on the system: fuel cell operating pressure > fuel cell operating temperature > electrolyzer operating temperature. This study provides references for improving the equipment working performance and designing high-performance electrolyzers and fuel cells.

离散元法 (EDEM) 仿真与参数优化： 低损高效玉米脱粒装置的设计与试验

Aiming at the problems of low threshing efficiency and high damage rate of current threshing devices. In this study, the operational form of the threshing drum and the structure of the threshing element were innovated, and a new threshing drum with low damage and high efficiency was designed. Using EDEM software, flexible body modeling of corn kernels, cobs and whole ears was carried out. The dynamic analysis of the corn threshing process was completed and the simulation parameters were further optimized. The optimum operating parameters were analyzed by orthogonal rotational tests and response surface method with a speed of 800 r/min for the threshing drum, a clearance of 10 mm for the concave plate and 30 mm for the threshing drum. The radius of the round head of the threshing element was 5 mm. The height of the threshing element was 60 mm. The final threshing efficiency was 98.78% and the damage rate of threshing was 0.62%. The results show that the new threshing device can meet the requirements of low-loss threshing devices for corn combine harvesters and can provide a theoretical basis for the development of the theory and technical system of corn plot combine harvesters in the future.

Design and experiment of a soybean shaftless spiral seed discharge and seed delivery device

When the driven stubble-breaking and anti-blocking no-till planter operates in the Southwest China, the stubble-breaking blades will impact with the ground as they cut through the soil and straw stubble, causing the planter to vibrate. This results in poor performances of the seed discharge by seed discharger and the seed guide by the seed guide tube. Based on the principle of spiral conveying, a soybean shaftless spiral seed discharge and seed delivery device was designed. The optimum seed filling size and speed range of the spiral blade were obtained by analyzing the size, force, and motion of soybean seeds of "ZhongHuang 37". The quadratic regression orthogonal rotation test and response surface method were used to analyze the operating parameters of the shaftless spiral seed discharge and seed delivery device by joint EDEM (Discrete Element Method)-RecurDyn simulation. The optimum parameters were obtained: the spacing of spiral was 11.4 mm, spiral outer radius was 5.5 mm, spiral inner radius was 2.9 mm and rotation speed was 10.4 r·s−1. Based on simulation and optimization results, the device was trialed and its field performance was tested. The results showed that at a surface slope of 16.1°, an average surface flatness of 8.9 cm, an average planter vibration frequency of 75.2 Hz, and an average amplitude of 7.2 mm, the average seeding qualification index, multiple index, missing seeding index, and damage index of the shaftless spiral seed discharge and seed delivery device were 92.6%, 5.03%, 2.4% and 0.92%, respectively, which were in line with the local agronomic requirements. The designed soybean shaftless spiral seed discharge and seed delivery device meets the requirements of the quality of no-till seeding and can provide a reference for the design and improvement of seed discharger and seed guide tube under poor ground leveling and long-distance seed delivery conditions.

Innovative Design and Mechanical Analysis of Low-Resistance Fritilariae Ussuriensis Maxim Excavation Device

Fritilariae ussuriensis maxim can be used as a medicine with little difficulty in its planting, but owing to its fragile characteristics, Fritilariae ussuriensis maxim is mainly collected by manual excavation. In order to solve the problems of the low working efficiency and poor environmental adaptability of the harvesting equipment of Fritilariae ussuriensis maxim, this paper designs a new excavation device, which can effectively reduce the operation resistance and improve the excavation efficiency of Fritilariae ussuriensis maxim. In this paper, the finite element method and discrete element method are used to simulate and analyze the operation performance of the excavation device. Combined with the orthogonal test and single factor test, the factors affecting the operating performance of the excavating device were explored. The excavating experimental platform was designed and built, and the simulation results were verified with experimental excavation data. This study shows that the operating speed, shovel face inclination angle, and digging depth had significant effects on the digging resistance of the shovel body, with the shovel face inclination angle having the highest influencing factor and the operating speed having the lowest influencing factor. Combined with the orthogonal test analysis and response surface design, the optimal operating parameters of the shovel body are: operating speed 0.5 m/s, shovel face inclination angle 25°, and excavation depth 120 mm.