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In response to the lack of accurate and reliable parameters in the discrete element simulation analysis of the sugarcane leaf crushing and return device, in this work, the actual and simulated errors of two stacking angles α and β of sugarcane leaves were used as indicators to calibrate the discrete element parameters. The second-order regression models between the important parameters and the indicators were obtained by Plackett-Burman test, steepest climb test, and Box-Behnken optimization test, and the analysis of variance and interaction factors were performed. The response surface method and particle swarm optimization algorithm were used to find the best significance parameters, and the best combination of significance parameters was obtained: the static friction coefficient between sugarcane leaves was 0.306, the rolling friction coefficient between sugarcane leaves was 0.198, and the recovery coefficient of sugarcane leaf-plate collision was 0.102. The relative errors of the simulation results and the physical test stacking angle α and stacking angle β were 0.609% and 1.643%, respectively. The calibration parameters can provide a theoretical reference for the design and research of sugarcane leaf crushing and returning machines, as well as the calibration of discrete element model parameters for leaf crops with high water content.

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Railway Construction Technology is the property of Railway Construction Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This paper focuses on obtaining fundamental data for optimizing the design of intelligent equipment for cutting natural rubber and its key components. It uses natural rubber bark as the research subject and employs specific experimental apparatus to measure the physical properties and contact coefficients of the rubber bark. The discrete element method, along with the Hertz–Mindlin model featuring bonding contacts, are employed to create a discrete element model of natural rubber bark. Parameters are calibrated, and model validation is performed. Subsequently, a one-factor simulation test is conducted to assess various cutting angles of the rubber cutter knife. A secondary Fourier fitting is applied to fit the curve to the average shear force values obtained from the simulation. The results indicate that the lowest average shear force, at 84.345 N, occurs within the range of cutting angles between 25° and 30°. The corresponding optimal cutting angle is 29.294°, suggesting that cutting with low resistance can be achieved at this angle, leading to reduced power consumption. Following a statistical analysis of field rubber-cutting tests conducted in a forest setting, it was found that the average power consumption for rubber-cutting operations under the optimal cutting angle is 0.96 W·h. Additionally, the volume of rubber discharged in the initial 5 min period is 6.53 mL. These findings hold significant importance for guiding the optimization and enhancement of the design of intelligent equipment for cutting natural rubber and its key components. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The compressor plays a significant role in the compressed air energy storage (CAES) system, and its performance directly determines the overall efficiency of the system and the economy of energy storage. Internal flow losses and outlet distortion due to poor design of its radial inlet chamber (RIC) geometry can degrade the performance of downstream components and reduce compressor unit performance. In this article, a multiobjective optimization design is carried out for the RIC of the oblique flow compressor in CAES system, and a parametric optimization design method of the RIC annular convergent channel meridian profile is developed. The optimal Latin hypercube experimental design (opt LHD) method is used to generate the sample library, and the radial basis function neural network (RBFNN) is used to establish the surrogate model of each design parameter and RIC performance. The multiobjective optimization is executed by the second‐generation non‐dominated sorting genetic algorithm (NSGA‐II). After optimization, the area of the annular convergent channel of the RIC is expanded, the transition of the meridian profile is smoother, the distortion coefficient of the RIC is reduced by 0.58%, and the total pressure loss coefficient is reduced by 16.45%. By using the optimized RIC, the performance of oblique flow compressor has been improved. Compared with the original model, the total pressure ratio and isentropic efficiency of the whole machine at the design point have been increased by 0.6% and 0.32%, respectively. [ABSTRACT FROM AUTHOR]

Copyright of China Surfactant Detergent & Cosmetics (2097-2806) is the property of China Surfactant Detergent & Cosmetics Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

At present, various public health emergencies have forced a deeper study of measures to prevent infectious diseases. To prevent the spread of infectious diseases on large cruise ships, the use of negative pressure isolation cabins is an effective method. However, existing cruise ships rarely use negative pressure isolation cabins or use them with shortcomings such as unreasonable layout of air inlets, which do not effectively reduce the risk of infection for medical staff while isolating patients. To solve this problem, first, the method of active air interference and the principle of proximity of the fresh air outlet were examined in this paper, and four groups of optimization schemes were designed. Second, by analyzing the diffusion of droplets in three breathing modes (coughing, sneezing, and talking while wearing or not wearing a mask), the direction of droplets and the efficiency of pollutant discharge under the condition of coughing were compared. Finally, in this paper, the infection risk of contact transmission and aerosol transmission was optimized by using the linear quantitative evaluation method and MSDR method, respectively. The results showed that the auxiliary air intake layout of optimal scheme 2 can effectively reduce the risk of infection for medical personnel in negative pressure isolation cabins. This study provides a useful reference for the design and optimization of negative pressure isolation cabins in future cruise ships. [ABSTRACT FROM AUTHOR]

In a Cassegrain optical system, the surface precision of the primary mirror is an important factor in the quality of the image. The design of a lightweight primary mirror with a high-quality optical surface is crucial. In this thesis, an integrated mirror light engine design optimization process is proposed for an aviation optoelectronic device. It is based on the Kriging surrogate model and nests the topology optimization algorithm, which constructs the mirror RMS value response surface and obtains the dominant relationship between mirror structure and surface accuracy. The optimal surface figure lightweight structure of the mirror is obtained by optimizing the surrogate model with an additive criterion and multi-objective optimization analysis. The root mean square value (RMS) of the corresponding primary mirror is 10.41 nm, which is better than 1/40 λ (λ = 632.8 nm). This meets the optical design specifications. The optimal primary mirror structure is analyzed by using the finite element method, which verifies the precision of the Kriging surrogate model. It has an error of 0.28%. The kinetic analysis of the primary mirror shows that the primary mirror does not yield to plastic deformation or even failure under a three-way 20 g acceleration load. This meets the environmental suitability requirements. [ABSTRACT FROM AUTHOR]

Copyright of Rolling Stock (1002-7602) is the property of Rolling Stock Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas & Oil is the property of Editorial Department of Natural Gas & Oil and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The spatial layout and arrangement of obstacles in the built environment significantly affect its evacuation performance. However, few researchers focus on pedestrian simulation-based design optimization of built environment under emergency evacuation conditions. In this paper, we aim to evaluate the evacuation performance of optimized design solutions for traffic space in the teaching building of a primary school based on a pedestrian simulation approach and to quantify the effect of design parameters on evacuation time. Firstly, the level of traffic space design parameters was determined and optimized design solutions for the traffic space of the school building were generated. Secondly, based on the Anylogic simulation platform, the environment module and pedestrian evacuation behaviour rules of the teaching building were built to realize the evacuation behaviour simulation. Thirdly, the effect of the traffic space design parameters on the evacuation time of the teaching building was evaluated and the most significant design parameters were identified. Finally, the optimal combination of traffic space design parameters was proposed under evacuation performance orientation. The results show that the sensitivity of the traffic space design parameters to evacuation time is 31.85%. The effect of corridor width on evacuation time is 49.06 times greater than the staircase width. The optimal design combination for the traffic space in the teaching building of the primary school is a 3.0 m wide trapezoidal corridor combined with a 3.6 m wide staircase, and a 3.0 m wide fish maw corridor combined with 3.6 m wide staircase, guided by evacuation performance. The framework developed in this paper provides technical support for the development of evacuation performance-oriented design optimization of the built environment, and the results are intended to supplement the building design specifications. [ABSTRACT FROM AUTHOR]

The performance of the centrifugal compressor, which is the main component of the electric supercharger, significantly impacts the engine's dynamics, economy, emissions, and responsiveness. The purpose of this paper is to enhance the aerodynamic performance of the centrifugal compressor of the electric supercharger for the two-stroke engine by optimizing the design of its impeller and diffuser parameters. The paper employs the numerical simulation method and applies the Spalart–Allmaras turbulence model to solve the RANS equations to analyze the impact of impeller-related parameters on the centrifugal compressor's performance. Subsequently, the paper optimizes the initial model parameters based on the simulation results and confirms its performance through an experiment. The findings indicate that enhancing the isentropic efficiency and pressure ratio of the compressor can be achieved by increasing the number of blades on the impeller, selecting an appropriate blade backward angle, and increasing the relative outlet width. After optimization, the compressor's efficiency can achieve 0.842, the pressure ratio can reach 1.49 with a working margin of 22%, and the efficiency is enhanced by 1.4%, while the pressure ratio is increased by 1.8% compared to the pre-optimization state. Moreover, the optimized model is experimentally validated to meet the design requirements. [ABSTRACT FROM AUTHOR]

The accurate analysis of key components of a spherical hinge structure directly affects bridge quality and safety during construction. Considering the key components of a spherical joint structure as the research object, a refined calculation model for the spherical joint is established to examine its stress using finite element analysis. The influence of design parameters on the mechanical characteristics of the spherical hinge structure is systematically analyzed. The response surface method (RSM), devised using a Box–Behnken design, is used to optimize the design of the spherical hinge structure parameters. A response surface model is established to derive the scheme of the optimized spherical hinge structure design. Moreover, by comparing the structural contact stress and rotational traction force before and after optimization, the effectiveness and necessity of the spherical hinge structure optimization are verified. The result comparison shows that the maximum contact stress and rotational traction force in the spherical hinge structure after optimization are reduced by 13.86% and 8.42%, respectively, compared with those before optimization. The relative error between the calculated and predicted values is approximately 3%, indicating that the RSM is feasible for optimizing key components of the spherical hinge structure. Its optimization effect is evident. Based on the identified optimal parameters of the spherical hinge structure, a range of recommended design parameters for the key structure of the rotating spherical hinge at different load carrying capacities is established using the interpolation method, which provides a valuable reference for engineering practice. [ABSTRACT FROM AUTHOR]

Copyright of Lubrication Engineering (0254-0150) is the property of Editorial Office of LUBRICATION ENGINEERING and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Truss robot has strong handling ability, convenient operation and high positioning accuracy, and plays an extremely important role in the manufacturing industry. Aiming at the problems of poor operation stability and material redundancy caused by the self-weight of the truss robot, the structural optimization design was studied. At present, the structure optimization design of truss robots has a large number of finite element simulation calls, large time loss, and low optimization efficiency. In order to solve this problem, after analyzing the relationship between size, load, stress and deformation of truss robot beam components, a structural optimization design method based on Kriging model and PSO particle swarm algorithm was proposed, which can effectively reduce the number of finite, element simulation calls, save time and improve the optimization design efficiency. [ABSTRACT FROM AUTHOR]

Lightweight, high stability, and high-temperature adaptability are the primary considerations when designing the primary mirror of a micro/nano satellite remote sensing camera. In this paper, the optimized design and experimental verification of the large-aperture primary mirror of the space camera with a diameter of Φ610 mm is carried out. First, the design performance index of the primary mirror was determined according to the coaxial tri-reflective optical imaging system. Then, SiC, with excellent comprehensive performance, was selected as the primary mirror material. The initial structural parameters of the primary mirror were obtained using the traditional empirical design method. Due to the improvement of SiC material casting complex structure reflector technology level, the initial structure of the primary mirror was improved by integrating the flange with the primary mirror body design. The support force acts directly on the flange, changing the transmission path of the traditional back plate support force, and has the advantage that the primary mirror surface shape accuracy can be maintained for a long time when subjected to shock, vibration, and temperature changes. Then, a parametric optimization algorithm based on the mathematical method of compromise programming was used to optimize the design of the initial structural parameters of the improved primary mirror and the flexible hinge, and finite element simulation was conducted on the optimally designed primary mirror assembly. Simulation results show that the root mean square (RMS) surface error is less than λ/50 (λ = 632.8 nm) under gravity, 4 °C temperature rise, and 0.01 mm assembly error. The mass of the primary mirror is 8.66 kg. The maximum displacement of the primary mirror assembly is less than 10 μm, and the maximum inclination angle is less than 5″. The fundamental frequency is 203.74 Hz. Finally, after the primary mirror assembly was precision manufactured and assembled, the surface shape accuracy of the primary mirror was tested by ZYGO interferometer, and the test value was 0.02 λ. The vibration test of the primary mirror assembly was conducted at a fundamental frequency of 208.25 Hz. This simulation and experimental results show that the optimized design of the primary mirror assembly meets the design requirements of the space camera. [ABSTRACT FROM AUTHOR]

The EU's energy transition strategy highlights the significance of developing innovative energy models to encourage the utilization of renewable energy sources in urban areas. Utilizing local urban biomasses, including food waste, sewage, and green waste, can contribute to the establishment of energy systems that harness bio-waste for energy generation, thereby promoting circular economy principles and urban metabolisms. This paper proposes using a pre-design tool (based on soft computing approaches) that incorporates an initial analysis of the multidisciplinary feasibility of such systems as an effective strategy and valuable support for preliminary studies. It focuses on validating three "biomass ratio" parameters, integrating urban morphology and district characteristics with the amount of bio-waste in a peri-urban district comprising multifamily buildings. These parameters can be incorporated into a pre-design tool that facilitates multi-criteria decision analyses, aiding the design of innovative models that promote renewable energy sources in urban areas. The findings suggest that synthetic parameters can guide initial considerations, but they may overestimate the energy potential and should be further investigated. Hence, future research should explore complementary strategies for estimating biomass energy potential and extend the application of this methodology to other types of districts. [ABSTRACT FROM AUTHOR]

Copyright of Ordnance Industry Automation is the property of Editorial Board for Ordnance Industry Automation and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to study the deformation characteristics of the retaining structure under the coupled effect of excavation and dewatering in the affected area of fault zones, this paper takes a deep excavation project in the F1322 fault zone influence area in Shenzhen as an example. The research methods of theoretical analysis, numerical simulation and field measurement are used to conduct in-depth research on the deformation of the retaining structure caused by the excavation and dewatering of the foundation pit. The results show that considering the coupled effect of dewatering in the foundation pit, the energy method based on elastic theory is more accurate in solving the deformation of the retaining pile. By comparing and analyzing the theoretical calculation results, numerical analysis results, and field measurement values, we found that the numerical laws of the three are basically the same. Simplified calculations that only consider rotational deformation and ignore the translational deformation of the wall lead to large deviations between the theoretical calculation results and the measured values of the wall bottom deformation. In order to reduce the deviation between numerical results and measured values, the construction of the foundation pit should strictly adopt measures such as "sectional excavation, avoiding peripheral loads, and optimizing construction deployment", strengthen construction monitoring, and reduce the impact on the deformation of the retaining pile. The maximum deformation growth rate k (ΔSmax/Δ) of the retaining pile decreases approximately exponentially with the increase of the structural stiffness parameters (E and I) and the embedment ratio within a certain range. The sensitivity analysis of the lateral displacement of the retaining pile to different geological parameters is conducted, and the sensitivity factors of the geological parameters to the deformation of the retaining structure are obtained, namely the maximum internal friction angle, followed by the cohesion, and the elastic modulus is the smallest. Based on the original design plan, an optimization of the excavation design is proposed by reducing the stiffness of the support structure. Therefore, the research findings in this paper have significant theoretical and practical implications for the engineering design of excavation projects located in fault zones. By optimizing the excavation support system, not only can standardized construction procedures be achieved, but also investment costs can be reduced, and construction time shortened, which fully aligns with the current safety, economic, and sustainable design principles of excavation projects aiming to conserve resources. [ABSTRACT FROM AUTHOR]

In Xinjiang, in the process of whole stalk harvesting of cotton stalks, there is a problem that the cotton stalks are easily pulled off, and there is an urgent need to develop flexible stalk-pulling machines. Through literature, patent summary, and field research, it is found that domestic researchers have designed many kinds of machines for the problem of easy breaking of cotton stalks, but there is no flexible cotton stalk-pulling machine for the time being. In this study, two flexible cotton stalk-pulling machines were intended to address the problem of easy breakage of cotton stalks. On the basis of the first-generation machine, the design of the second-generation machine was improved. In order to further improve the operational performance of the flexible cotton stalks pulling tools, the operational mechanism of the core working parts of the tools was analyzed and a comparative test was done in a large field. Analysis and the comparative tests proved that improving the clamping working stroke s of the stalk-pulling components can effectively reduce the cotton stalks leakage rate. By using a flexible clamping process, a part of the deformation of cotton stalks can be transferred to the flexible material. To a certain extent, the deformation length L of the contact surface between the cotton stalk and the stalk pulling part is reduced, and the deformation displacement Δy is correspondingly lower. The toughness of the cotton stalk is not significantly decreased and the cotton stalk does not break easily. The improved second-generation machine has a 3.67% to 3.79% lower cotton stalks leakage rate and a 5.65% to 6.30% lower cotton stalks breakage rate than the first-generation machine. As the land in Xinjiang is clay soil, soil bonding to cotton stalks pulling force F2 is larger, resulting in cotton stalks being more difficult to be pulled out of the machine at once. The test proved that the improved second-generation implements had a significant improvement in the cotton stalk-pulling effect because of the subsequent pulling interval CD. The test results verify the analysis results and the research results can provide a theoretical basis for the subsequent structural improvement and performance enhancement of the flexible cotton stalk-pulling machine, which is of reference significance for solving the problem that the cotton stalks are easily pulled and broken in Xinjiang, China. [ABSTRACT FROM AUTHOR]

For a peanut-picking device with a feeding rate greater than 5 kg/s, the problem of low picking rate and high damage rate will occur during the picking process. A discrete element model is developed to determine the range of values of the main influencing factors affecting the peanut picking device. A three-factor, three-level orthogonal combination test was carried out with feeding volume, drum speed, and peanut-picking gap as test factors to investigate the effects of the main influencing factors on the quality of peanut picking operation of the peanut-picking device. The results of the field trials showed that the best results were achieved at the optimum combination of drum speed of 508 r/min, peanut-picking gap of 22 mm, and feeding volumes of 6.3 kg/s. At this time, the peanut picking rate was 99.17%, and the peanut breakage rate was 0.91, meeting the standard technical requirements for mechanized peanut harvesting. The study results provide a theoretical basis for further enhancing the development of peanut combine harvesting equipment. [ABSTRACT FROM AUTHOR]

Copyright of Computer Measurement & Control is the property of Magazine Agency of Computer Measurement & Control and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A molding machine of substrate grass seed blanket can take agricultural waste straw and livestock manure as the raw material, in order to fabricate the grass seed blanket after hand-holding and molding, particularly for the green lawn. Among them, aerobic fermentation can be also adopted to add the premixing liquid for complete decomposition. The continuous uninterrupted molding can be realized after drying below 60℃, transportation, and laying. The substrate grass seed blanket can be laid directly or half-buried in the ground for the urban, park, and residential greening. However, the existing molding machine cannot fully meet the large-scale production in the design of the initial size parameters. The weight of the larger support burden can tend to cause the uneven force of substrate at the extrusion outlet during extrusion molding. This study aims to reduce the component force deformation for better molding stability. Structural optimization was implemented with the extrusion outlet at the neck length, neck width, material plate thickness, and bolt hole diameter as the object using ANSYS Workbench 19.2. The maximum deformation was 0.85 mm, and the maximum equivalent force was 191.25 MPa, using parametric modeling. The response surface method (RSM) with multi-objective optimization was used to optimize the design of the squeeze outlet model. The maximum deformation was 0.54 mm, and the maximum equivalent force was 164.85 MPa. The topological optimization of the extrusion port was carried out to remove the unnecessary material dimensions without affecting the static analysis. The total weight of the part was reduced by 36.60%. EDEM software was used to verify the optimized extruded parts as a whole machine. The grass seed blanket molding was analyzed by the discrete element method with a simulation time of 30 s. Furthermore, the data extraction of the test indicators was performed by the post-processing module. The simulation was performed with the molding particle density and extruded particle quality as the indicators, which were 1 383.2 kg·m-3 and 2 685 g, respectively. The test prototype was made to conduct the germination and drying validation tests. The measured density and mass of the formed substrate grass seed blanket were obtained with an error of 6.7% and 2.7%, respectively, compared with the simulation. The validation test was compared with the test before optimization. The density of the formed particles and the mass of the extruded particles were significantly improved by 5.84% and 2.88%, respectively, before optimization. Consequently, the optimized extrusion outlet can be expected to improve the working efficiency of the forming machine. The formed grass blanket was enhanced with the increase of density between the particles of the substrate grass seed blanket. The quality of the blanket can also fully meet the requirements of the production use in the forming machine of substrate grass seed blanket. [ABSTRACT FROM AUTHOR]

Fuel for hydrogen fuel cell vehicles comes from hydrogen refueling stations. During the hydrogen filling process, a high-pressure gradient from 35 MPa (hydrogen storage pressure) to 0.16 MPa (fuel cell pressure) is generated. Such a large pressure gradient posed a challenge to the design of the pressure reducing system. Traditional system is difficult to reduce hydrogen pressure from 35 MPa to 0.16 MPa without accompanying large noise and energy consumption. This work is exploring a new concept to combine the multi-stage continuous resistance perforated components and the Tesla valve to design a two-step high pressure reducing system for hydrogen decompression. To validate the superiority of the developed system, a detailed aerodynamic study on the new system is performed, since aerodynamic performance directly affects the operating flexibility and stability. Finally, the optimized co-design of the system is achieved. Results show that the new system is well-designed for hydrogen decompression with the function of control noise and energy consumption. Larger orifice radius (r 1 /r 0) and orifice ratio (k) contribute the better aerodynamic performance. Angle α = 45° is considered the best for better aerodynamic performance. The descending order of the effects on better aerodynamic performance is angle (α), row (m), sleeve stage (N), orifice radius (r 1 /r 0) and width (t 1 /t 0). This study provides basic support for experts to achieve throttling design of related pressure control systems in hydrogen industry. • A new two-step high pressure reducing system for hydrogen decompression is proposed. • A detailed aerodynamic study on the newly designed system is performed. • The optimized co-design of the system is achieved. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Engineering for Thermal Energy & Power / Reneng Dongli Gongcheng is the property of Journal of Engineering for Thermal Energy & Power and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The torsional guided wave magnetostrictive transducer (MsT) based on the reversed Wiedemann effect has received much attention because of its high energy conversion efficiency and easy implementation of bias magnetic field. However, the coil is wound on the magnetostrictive patch which leads to the reduced coupling efficiency. And the coil winding process for MsT is also time-consuming. This paper proposes a new design of torsional guided wave MsT with circumferential alternating permanent magnet array. The permanent magnets with axial direction magnetization are alternately arranged along the circumference of the pipe. The meander coil is placed between the permanent magnet array and the pipe. On this basis, a magnetic circuit device is applied to increase the amplitude and uniformity of the bias magnetic field, making the transducer to achieve larger energy conversion efficiency. It has been proved experimentally that the designed MsT can generate T (0,1) guided wave with stronger energy. The amplitude of the guided wave signal increases by 2.8 times with the same excitation conditions. Moreover, the transducer has a wide bandwidth. Its center frequency corresponds to the wavelength λ, and the magnetostrictive patch width is about 0.5 λ or 1.5 λ. In conclusion, the proposed transducer has higher energy conversion efficiency and is also easier to design and install, making it more suitable for the health monitoring of large industrial equipment. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ordnance Equipment Engineering is the property of Chongqing University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the application of bone scaffolds becomes more and more widespread, the requirements for the high performance of bone scaffolds are also increasing. The stiffness and porosity of porous structures can be adjusted as needed, making them good candidates for repairing damaged bone tissues. However, the development of porous bone structures is limited by traditional manufacturing methods. Today, the development of additive manufacturing technology has made it very convenient to manufacture bionic porous bone structures as needed. In the present paper, the current state-of-the-art optimization techniques for designing the scaffolds and the settings of different optimization methods are introduced. Additionally, various design methods for bone scaffolds are reviewed. Furthermore, the challenges in designing high performance bone scaffolds and the future developments of bone scaffolds are also presented. [ABSTRACT FROM AUTHOR]

China is a large flax-growing country, with planting area and production ranking among the top three in the world. However, the cultivation range of flax in China is very broad, complex, and diverse, resulting in different planting scales and patterns, making it difficult to apply foreign large combine harvesters, and China lacks a dedicated flax combine harvester. This research improved the design of the 4LZ-4.0 crawler-type flax combine harvester for the regional features and flax cropping patterns in China. First, the structure, technical parameters, and working principles of the machine were introduced; second, the theoretical analysis and optimization of key components were performed; and finally, with the advancing speed of the machine, the speed of the threshing drum, and the speed of the suction fan as independent variables and the rate of removal and the total loss rate as response values, a three-factor, three-level response surface analysis method was used. For each component and response value, a mathematical model was created, and the factors and their interactions were evaluated and confirmed. The results demonstrated that the three parameters impact the threshing drum speed, advancing speed, and centrifugal fan speed in that order of priority, as well as the total loss rate in that order of priority. The machine's optimal operating settings were 1.5 m·s−1 advancing speed, 788.49 r·min−1 threshing drum speed, and 885.34 r·min−1 centrifugal fan speed, and the validation test results indicated that under the typical dryland dense flax cultivation mode, it had a 97.46% threshing rate and 2.99% total loss rate after the test. This demonstrated that optimizing operational parameters may decrease losses in the process of mechanical flax harvesting, enhance harvesting efficiency, and satisfy the marketable flax harvesting standards. [ABSTRACT FROM AUTHOR]

Glass curtain walls (GCWs) have become prevalent in office buildings, owing to their lightweight and modular characteristics. However, their lower thermal resistance, compared to opaque walls, results in increased energy consumption. Incorporating phase-change materials (PCMs) provides a viable solution through which to address the susceptibility of GCWs to external conditions, thus enhancing thermal performance and mitigating energy concerns. This study delves into the influences of the glazing solar heat gain coefficient (SHGC), the glazing heat transfer coefficient (U-value), and PCM thickness on the energy performance of buildings. Using Design Builder (DB) software version 6.1.0.006, a multi-story office building was simulated in different climatic zones in China, covering the climatic characteristics of severe cold, cold, hot summer and warm winter, cold summer and winter, and mild regions. The simulation results quantitatively elucidated the effects of the glazing parameters and the number of PCMs on thermal regulation and energy consumption. A sensitivity analysis identified the glazing SHGC as the most influential factor in energy consumption. Additionally, by employing Response Surface Methodology (RSM), the researchers aimed to achieve a balance between minimal building energy consumption and economic cost, ultimately determining an optimal design solution. The results demonstrated significant energy savings, ranging from 20.16% to 81.18%, accompanied by economic savings, ranging from 15.78% to 79.54%, across distinct climate zones in China.

In order to design an involute spline made of PEEK (polyetheretherketone)-based material with better performance and improve the design rules of involute splines, initially, an involute splines design theory for PEEK (polyetheretherketone)-based materials is presented, which combines international standards (ISO 4156, 1. 2. 3, 2005), American standards (ANSI B92.2M. 1989), and traditional empirical formulas. Second, using the involute splines calibration method in international standards as a guide, we developed the involute splines calibration method for PEEK-based materials by estimating the impact of energy consumption caused by viscoelasticity on temperature field calibration. Next, the contact characteristics of the designed spline were analyzed using ABAQUS2022 software to confirm the accuracy and reliability of the design and calibration methods. Finally, finite element simulation was used to analyze the influence of different pressure angles, moduli, combined lengths, and other parameters on the contact characteristics of the spline in order to realize the optimal design of PEEK-based material involute splines, to offer a theoretical foundation and improved design methodology for cylindrical straight-tooth involute splines.

In recent decades, the development of electronic technology has provided opportunities for the Internet of Things, biomedicine, and energy harvesting. One of the challenges of the Internet of Things in the electrification era is energy supply. Centralized energy supply has been tested over hundreds of years of history, and its advantages such as ideal output power and stable performance are obvious, but it cannot meet the specific needs of the Internet of Things, and distributed energy supply also has a large demand. Since the invention of nanogenerators, another promising solution for fluid energy harvesting has been opened up. The triboelectric nanogenerator is an emerging platform technology for electromechanical energy conversion, which can realize the collection of fluid energy such as wind energy and wave energy. In this paper, we first introduce the fundamentals of triboelectric nanogenerators and their applications in wind and wave energy harvesting devices. We then discuss the methods of device optimization in the next development of TENG and conclude by considering the future prospects and challenges for triboelectric nanogenerator harvesting devices.

In order to improve the safety and reliability of electric vehicle wireless charging, foreign object detection is an indispensable auxiliary function. In this paper, the equivalent model of foreign object detection circuit is firstly established, and then the foreign object detection principle based on active detection coil is analyzed from the angle of the circuit and magnetic circuit. Then the optimization scheme of metal foreign object detection coil is proposed through simulation comparison and analysis. The results show that the design proposed in this paper can increase the maximum value of |Bz| to 3.6 mT, effectively improving the accuracy of metal foreign object detection.

In the paper，we introduce the development history and current situation of gravity survey network in Shandong Province, including the construction of gravity survey network in the 13th five-year plan of Shandong Province. Then we think it is necessary to optimize Shandong gravity network, especially to increase gravity survey points in the western region of Shandong Province. At present, the scope of Shandong gravity network is expanded from the southern Shandong and the Jiaodong region networks to the western Shandong network. It is also connected with Henan and Hebei networks to achieve full coverage in Shandong and its neighboring provinces. The design of Shandong gravity network such as partition and measurement route is elaborated, and the characteristics and accuracy requirements of the network type are explained. Finally, the monitoring capability of Shandong gravity network is evaluated.

• Perovskite solar cell stability was investigated intensively using machine learning techniques. • An extremely randomized trees technique, trained with a dataset containing 1050 perovskite device samples, is used. • The techniques findings are compared with previous experimental results for screening the most optimized combinations for long-term stability. • The proposed ML strategy succeeded in captivating the suitable combination of materials, deposition methods, and storage conditions. • The adopted method unveils the importance of manufacturing techniques in realizing efficient and stable solar cells. This work aims to analyze the stability of Perovskite solar cells PSCs using machine learning (ML) techniques. An extremely randomized trees technique, trained with a dataset containing 1050 perovskite device samples with different materials, deposition methods and storage conditions, is used. Pushing by its non linearity and randomity, this approach is an intriguing choice for decreasing the variance of the total model. The effects of data inputs on the stability of the device are investigated by analysing the Decision Trees (DT) constituent of the Extra Trees (ET) while the feature importance technique was used for feature engineering. The two techniques findings are compared with previous experimental results for screening the most optimized manufacturing materials and storage conditions for long-term stability. For regular cells, TiO 2 /m-TiO 2 as electron transport layer (ETL), (2D-3D) perovskite as active layer, P 3 HT and LiTFSi + TBP as hole transport layer (HTL) and HTL second layer, and Carbon as back contact were found to enhance the device stability with DMF + DMSO as precursor solution and Chlorobenzene as an anti-solvent solution. For inverted cells, BCP and PCBM, MAPBl 3-x Cl x , NiO and DEA, Al back contact were found to improve stability. The obtained results provide evidence of the aptness of the proposed ML strategy in captivating the suitable combination of different layer materials, deposition methods, and storage conditions. Besides, the adopted method unveils the importance of manufacturing techniques in realizing efficient and stable solar cells. [ABSTRACT FROM AUTHOR]

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Copyright of Xinjiang Agricultural Sciences is the property of Xinjiang Agricultural Sciences Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the process of urbanization development, high-rise buildings have been developed rapidly as a unique architectural structure with large floor area ratio and large number of people, at the same time, a higher risk of building fires is brought to the city. Especially with the design and use of the concave facade wall structure, the fire spread characteristics of the building have been significantly affected. FDS numerical simulation technology was used to study the fire temperature and flame front propagation rate under the influence of different concave facade structural factors. The results showed that the chimney effect of vertical fire spread on the concave facade was more obvious. The height of the flame front conforms to the exponential exponential function change relationship with time, when the structure factor of concave facade ∂ = 0. 5, the vertical spread rate of the fire front reached the maximum. Accordingly, the reasonable setting of fireproof eaves was proposed to effectively prevent the spread of fire along the concave facade to adjacent residents at high places. The research results have certain theoretical guiding significance for the optimal fire safety design of concave facade building structure. [ABSTRACT FROM AUTHOR]

Copyright of Guangdong Architecture Civil Engineering is the property of Guangdong Architecture Civil Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)