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Nowadays, magnetic bearing has been used in more and more fields. Displacement sensor is one of the most important functional components of a magnetic bearing system and have attracted more and more attentions. Inductance displacement sensor, which shows merits in maintainability, lifetime, sensitivity, environmental interference ability, and cost, is a potential displacement sensor for magnetic bearing systems. While, usually, for a certain application, installation space of displacement is limited, increasing the difficulty of sensitivity improvement by stator structure optimization. This paper presents a novel approach for axial inductance displacement sensor to improve sensitivity by decreasing the armature depth. In the experiment part, three armature with different depth have been fabricated and their performance are tested. The results show that sensitivity is improved from 2.34 mV/µm to 3.15 mV/µm when the depth of armature decreases from 24 mm to 18 mm, validating the feasibility of sensitivity improvement by decreasing the armature depth. With the improvement of sensitivity, resolution also improves from 5.1 µm to 3.8 µm. Negative effect of this approach is that measuring range is decreased when the armature depth is reduced. [ABSTRACT FROM AUTHOR]

Enhancing the activity of oxygen evolution reaction (OER) is crucial for improving the efficiency of electrochemical water splitting (EWS). The highly adjustable electronic structure and potential high conductivity of transition metal sulfides (TMSs) make them promising candidates for OER electrocatalysts. Herein, we have synthesized trimetallic sulfides Fe 2 Ni 1 Zn 1 –S(II) based on layered double hydroxides (LDHs) precursor employing a facile and efficient two-step solvothermal approach. Benefitting from the multi-metallic synergistic effect and the distinctive interfacial structure, Fe 2 Ni 1 Zn 1 –S(II) shows excellent electrocatalytic OER performance (η 10 = 252 mV, Tafel slope = 64.2 mV∙dec−1). Meanwhile, it has outstanding stability (50 h) in 1 M KOH, which is better than RuO 2 and many other metal sulfide electrocatalysts. Furthermore, it was found that the structure of the catalyst was still retained after OER test, which further verified its catalytic stability. This work supplies an effective route for the preparation of LDHs derived multi-metallic sulfides. [Display omitted] • Modulation of the surface electronic structure of catalysts through multi-metal synergistic effect. • Layered double hydroxides offer a unique layered structure and high electrochemical activity. • Transition metal sulfides provide high electrical conductivity. • This study provides an effective way to further optimize the structure of transition metal sulfides. [ABSTRACT FROM AUTHOR]

Zinc‐based batteries are emerging as the most promising candidates for large‐scale energy storage devices due to their low cost, high safety, and long‐term storage. However, zinc‐based batteries encounter challenges stemming from undesirable side reactions and zinc dendrites on the anode, as well as dissolution on the cathode. Owing to their extremely small size, substantial surface functional groups, and adjustable structure, carbon dots (CDs) present considerable benefits in augmenting coulombic efficiency, expanding cycle life, and enhancing the rate functionality of zinc‐based batteries. Herein, this review delves into the surface modification and morphological regulation of batteries elements by CDs, CDs composites, and CDs derivatives. Moreover, it systematically encapsulates the application of CDs in zinc‐based batteries, underscoring the pivotal role of CDs in the advancement of electrode technology. Finally, the review highlights the impediments and proposes potential avenues for utilizing CDs in zinc‐based batteries. This review aims to facilitate the development of superior solutions and provide scientific insights into energy storage technologies. [ABSTRACT FROM AUTHOR]

Accurate measurement of the pretightening stress for bolts has great significance for improving the assembly quality and safety, especially in severe environments. In this study, AlN thin film transducers were deposited on GH4169 nickel base alloy bolts using the RF magnetron sputtering, enabling a systematic investigation into the correlation between structures and the intensity of ultrasonic echo signals. Employing the finite element method resulted in consistency with the experimental data, enabling further exploration of the enhancement mechanism. With the increasing thickness of both the piezoelectric layer and the electrode layer, the intensity of the ultrasonic echo signals saw a great enhancement. The maximum-intensity observed increase is 14.7 times greater than that of the thinnest layers. Specifically, the thicker piezoelectric layer improves its mechanical displacement, while the increased thickness of the electrode layer contributes to better densification. An electrode diameter of nearly 4 mm is optimal for an AlN thin film transducer of M8 bolts. For pretightening the stress measurement, the sample with a strong and stable echo signal shows a low measurement error of pretightening below ±2.50%. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chongqing University of Technology (Natural Science) 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 Drainage & Irrigation Machinery Engineering / Paiguan Jixie Gongcheng Xuebao is the property of Editorial Department of Drainage & Irrigation Machinery 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.)

The development of novel nitride-based phosphors is always a significant work, especially for AlON system because of their rigid crystal structure, which is similar to the promising host material of β-SiAlON. In this work, Mg2+ ion was introduced into AlON-related phase Al 5 O 3 N 3 along with co-doped Si4+ ion used to keep charge neutrality, and thus a novel Mg-based nitroaluminosilicate MgAl 3 SiO 3 N 3 (MASON) was successfully synthesized under a mild preparation condition due to the high reactivity of MgO. Benefiting from its special crystal structure optimized by the introduction of Mg2+ ion, Eu2+-activated MASON performs significant photoluminescence (PL) and cathodoluminescence (CL) properties. In contrast to most Eu2+-activated AlON related phosphors that commonly emit high-energy blue light, the as-prepared sample emits a high-bright green light along with good thermal stability. Moreover, its broad emission band with the full width at half maximum (FWHM) of 134 nm well compensates the "cyan cavity", which leads to a full spectrum light-emitting diode. The structure-property relation of Eu2+ in MASON was established in this work, which confirms the significant role of the introduced Mg2+ ion in the structure optimization of AlON system. The result may pave an efficient way to explore more promising AlON-based phosphors. High-brightness green light emission was achieved in Eu2+-activated nitroaluminosilicate MgAl 3 SiO 3 N 3. [Display omitted] [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.)

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.)

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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 study introduces an integrated structural optimization design method based on a BP neural network and NSGA-II multi-objective genetic algorithm. Initially, a two-dimensional axisymmetric finite element model of the Giant Magnetostrictive Actuator (GMA) was established, and the coupling simulation of the electromagnetic field, structural field, and temperature field was conducted to obtain the GMA's performance parameters. Subsequently, the structural parameters of the GMA magnetic circuit, including the magnetic conducting ring, magnetic conducting sidewall, magnetic conducting body, and coil, were used as inputs, and the axial magnetic induction intensity, uniformity of axial magnetic induction intensity, and coil loss on the Giant Magnetostrictive Material (GMM) rod were used as outputs to establish a back propagation (BP) neural network model. This model delineated the nonlinear relationship between structural parameters and performance parameters. Then, the BP-NSGA-II algorithm was applied to perform multi-objective optimization on the actuator's structural parameters, resulting in a set of Pareto optimal non-dominated solutions, from which a set of optimal solutions was obtained using the entropy weight method. Finally, simulation analysis of this optimal solution was conducted, indicating that under a 5 A power supply excitation, the maximum axial magnetic induction intensity on the optimized GMM rod increased from 0.87 T to 1.12 T; the uniformity of axial magnetic induction intensity improved from 93.1% to 96.5%; and the coil loss decreased from 7.79 × 104 W/m3 to 4.97 × 104 W/m3. Based on the optimization results, a prototype actuator was produced, and the test results of the prototype's output characteristics proved the feasibility of this optimization design method. [ABSTRACT FROM AUTHOR]

Numerous efforts in the additive manufacturing literature have been made toward in-situ defect prediction for process control and optimization. However, the current work in the literature is limited by the need for multi-sensory data in appropriate resolution and scale to capture defects reliably and the need for systematic experimental and data-driven modeling validation to prove utility. For the first time in literature, we propose a data-driven neural network framework capable of in-situ micro-porosity localization for laser powder bed fusion via exclusively within hatch strip of sensory data, as opposed to a three-dimensional neighborhood of sensory data. We further propose using prior-guided neural networks to utilize the often-abundant nominal data in the form of a prior loss, enabling the machine learning structure to comply more with process physics. The proposed methods are validated via rigorous experimental data sets of high-strength aluminum A205 parts, repeated k-fold cross-validation, and prior-guided validation. Using exclusively within hatch stripe data, we detect and localize porosity with a spherical equivalent diameter (SED) smaller than 50.00 μ m with a classification accuracy of 73.13 ± 1.57 % This is the first work in the literature demonstrating in-situ localization of porosities as small as 38.12 μ m SED and is more than a five-fold improvement on the smallest SED porosity localization via spectral emissions sensory data in the literature. In-situ localizing micro-porosity using exclusively within hatch-stripe data is a significant step towards within-layer defect mitigation, advanced process feedback control, and compliance with the reliability certification requirements of industries such as the aerospace industry. [ABSTRACT FROM AUTHOR]

The high-power laser diode (HPLD) has witnessed increasing application in space, as the aerospace industry is developing rapidly. To cope with the space environment, optimizing the heat-dissipation structure and improving the heat-dissipation ability via heat conduction have become key to researching the thermal reliability of the HPLD in space environments. Based on a theoretical analysis of the HPLD, a simulation model of the HPLD was constructed for numerical simulation, and it was found that the maximum temperature and thermal resistance of lasers were efficaciously decreased by changing the packaging position of laser bars. The packaging position of the bars and the cutting angle of the microchannel heat sink (MCHS) were determined based on the light-emitting angle of the light-emitting unit and the internal structure of the MCHS. The internal structure of the MCHS was optimized through a single-factor experiment, an orthogonal experiment, and the combination of neural networks and genetic algorithms (GAs), using three key structural parameters, namely the MCHS ridge width, W1, the channel width, W2, and the channel length, L1. After optimization, the performance of the MCHS was obviously improved. Finally, an analysis was carried out on the applicability of the optimized MCHS to bars with a higher power. [ABSTRACT FROM AUTHOR]

The cutterhead is one of the core components of the shield machine, and reasonable cutterhead structural design is the foundation for safe and efficient excavation. In order to quickly and efficiently establish the finite element model of the cutterhead and then analyze its mechanical properties, a parameterized modeling method based on the ANSYS parametric design language (APDL) command flow was adopted to establish a digital model of a certain type of composite shield machine cutterhead. By applying the ultimate thrust and torque to the cutterhead, the stress and deformation distributions were obtained through a finite element analysis, and the positions where experience maximum stress and displacement were identified. In doing so, the strength and stiffness conditions were validated as well. In addition, a parameterized modeling based optimization method for cutterheads was established by incorporating with the overall mass of the cutterhead as the optimization objective and the strength and stiffness of as constraints, and the corresponding optimization process was proposed. The optimization parameters of the cutterhead were determined through parameter sensitivity analysis, and the influence of relevant parameters on the strength and stiffness of the cutterhead was explored. The key parameters of the composite shield machine cutterhead studied were optimized. After optimization, the maximum stress of the cutterhead, the maximum deformation and the total weight were reduced by 12%, 20%, and 119 kg, respectively. As a result, the proposed optimization method based on parameterized modeling can improve the strength and stiffness of the cutterhead while reducing the quality of the cutterhead. The research results can shed light on the optimization of multi-objective cutterhead structure. [ABSTRACT FROM AUTHOR]

An optimization design was carried out based on a back propagation (BP) neural network and a genetic algorithm (GA) to improve the stiffness and accuracy of the self-developed MGK6030 five-axis tool grinding machine. First, finite element analysis was carried out on the whole grinding machine based on ANSYS Workbench, and the key parts were found to be the grinding wheel headstock, B axle box body, and column. Sensitivity analysis was carried out after the model parameterization, and ten parameters, which affect the quality, maximum deformation, and first-order mode, were obtained. These parameters were used as input variables. A total of 235 sets of sample data were obtained by using the optimal overall performance of the grinder for the target (large first-order natural frequency, small deformation, and mass). The BP neural network was then used to fit the nonlinear coupling relationship between the input and the output. Thereafter, the optimization function of the GA was used to perform multi-objective optimization in the specified range. Finally, the parameters are verified by software simulation and prototype test. Results showed that the maximum deformation of the optimized machine tool is reduced by 21%, and the first four order natural frequencies are increased by 6.36%, 9%, 6.4%, and 2.84%. The positioning accuracies of the linear axis and rotary axis are increased by 22% and 21%, respectively, which demonstrates the effectiveness of the optimization scheme and provides theoretical and technical support for similar optimization problems. [ABSTRACT FROM AUTHOR]

Additive manufacturing has emerged as a promising technique in energy device research, owing to its ability to fabricate programmable geometries. Nevertheless, it remains a significant challenge to prepare three-dimensional electrode structures with finely resolved features. Herein, we propose a vat photopolymerization (VP) 3D printing process for Nickel Oxide-Yttria Stabilized Zirconia (NiO-YSZ) anode structure of solid oxide fuel cell (SOFC). A photosensitive NiO-YSZ slurry was prepared with appropriate curing properties, low viscosity, and stability. Optimal debinding processes, determined through thermo-gravimetric analysis, were employed to prevent green part cracking and deformation. Microstructural analysis demonstrated a uniform and finely distributed pore structure in the anode. Remarkably, cells featuring the VP-printed NiO-YSZ anode demonstrated notable performance with peak power densities of 239 mW·cm−2, 364 mW·cm−2, and 536 mW·cm−2 at 750 °C, 800 °C, and 850 °C, respectively. This novel method opens avenues for enhancing the performance of SOFCs through the optimization of anode structure. [ABSTRACT FROM AUTHOR]

The cylinder mass affects the ball mill's operation and economy. To reduce the mass of the current cylinder, this paper utilized a response surface optimization module and a multi-objective genetic algorithm to optimize the cylinder structure. First, the optimal parts of the cylinder were determined by static analysis. Subsequently, the mathematical model was established with the goal of achieving structural lightweight. Then, the size of the cylinder was optimized based on the response surface optimization module and multi-objective genetic algorithm. Finally, the static analysis and modal analysis results before and after optimization were compared to verify the stress and resonance of the structure, and the optimization effect was evaluated. The optimized cylinder had a mass reduction of 15.624 % without compromising the strength and deformation. The optimization design can save materials and costs, and provide a theoretical reference for the lightweight research of the ball mill's cylinder. [ABSTRACT FROM AUTHOR]

Compartment dryers for fruits and vegetables involve problems including dead zones and nonuniform drying. To address these problems, experimental and numerical analyses are carried out in this study using an airflow control equation and the k-omega SST model to optimize the structural parameters of the drying section in the compartment dryer. The dryer was numerically simulated using Fluent software, and the dryer structural parameters (i.e., numbers of hot-air inlets and outlets, aperture size, and tilt angle) were optimized using response surface analysis. Subsequently, the airflow distribution within the dryer was determined by using Fluent software; the temperature nonuniformity coefficient (Mt), the velocity nonuniformity coefficient (Mv), the temperature deviation ratio (Et), and the velocity deviation ratio (Ev) served as evaluation metrics for airflow uniformity in the dryer. The results revealed that Mt, Mv, Et, and Ev decreased by 25.47%, 30.49%, 28.41%, and 14.74%, respectively, enhancing the airflow uniformity in the dryer. [ABSTRACT FROM AUTHOR]

Copyright of Tunnel Construction / Suidao Jianshe (Zhong-Yingwen Ban) is the property of Tunnel Construction 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 Automobile Technology & Material is the property of Automobile Technology & Material 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.)

To address the problem of undesirable prediction accuracy of a deep echo state network caused by redundant structures in the reservoirs, a pruning algorithm for the deep echo state network based on detrended multiple cross-correlation was proposed. Firstly, according to the detrended covariance function and the detrended variance function, the detrended cross-correlation coefficient between each two neurons in the selected reservoirs in turn was calculated, and the detrended cross-correlation matrix was constructed. Based on this matrix, the detrended multiple cross-correlation between a selected neuron and all remaining neurons in this reservoir could be evaluated. Subsequently, the connections from the highly correlated neurons in each reservoir to the output layer were pruned sequentially, thus removing redundant components in the network. Finally, the network after pruning was retrained by least squares regression to obtain the optimal deep echo state network topology. Simulation results showed that the prediction accuracy and memory capacity of the deep echo state network optimized by the proposed algorithm on Mackey-Glass time series were improved by 89. 80% and 30. 93%, respectively, and on Call time series by 14.34% and 0.10%, respectively. [ABSTRACT FROM AUTHOR]

This paper designs a kind of air suspension mechanical-vibration-reduction wheel for mining engineering vehicles; the research work on topology analysis and the structural optimization of the inner and outer rims are carried out with this wheel as the research object. Using Workbench finite-element analysis software, taking the results of static analysis and modal analysis of the two as constraints, a variety of structural improvement styles are obtained through a topology analysis method and compared and verified, and a more reasonable improvement result is selected and assembled into a whole wheel for final analysis and verification. The results show that the optimization results of the wheel still meet the design's load-bearing requirements, and the weight is lighter; the topology analysis results are ideal. [ABSTRACT FROM AUTHOR]

Engineers pay more and more attention to the economic benefits of foundation pit engineering. At present, the optimal design of the foundation pit supporting structure mainly focuses on strength and functional design, and there is no mature theoretical design method for deformation control. In this paper, a method for calculating the overall deformation of a foundation pit supporting structure based on the principle of minimum potential energy is proposed. Based on this method, the optimal design of the foundation pit of Guangzhou Baiyun District Comprehensive Transportation Hub Metro Station is realized. The deformation calculation results and optimization design scheme are validated by finite element numerical simulation and field monitoring data. The results show that the proposed theoretical algorithm predicts the pile deformation curves better than the finite element method, suggesting the proposed theoretical method is reasonable and the optimization scheme of the retaining pile is feasible. In the optimized design, the deformation of the foundation pit retaining pile is controlled by its push-back effect. The proposed deformation calculation method can realize the overall deformation calculation of the foundation pit supporting structure. [ABSTRACT FROM AUTHOR]

With the increasing resistance of Acinetobacter baumannii (A. baumannii) to antibiotics, researchers have turned their attention to the development of new antimicrobial agents. Among them, coumarin-based heterocycles have attracted much attention due to their unique biological activities, especially in the field of antibacterial infection. In this study, a series of coumarin derivatives were synthesized and screened for their bactericidal activities (Ren et al. 2018; Salehian et al. 2021). The inhibitory activities of these compounds on bacterial strains were evaluated, and the related mechanism of the new compounds was explored. Firstly, the MIC values and bacterial growth curves were measured after compound treatment to evaluate the antibacterial activity in vitro. Then, the in vivo antibacterial activities of the new compounds were assessed on A. baumannii-infected mice by determining the mice survival rates, counting bacterial CFU numbers, measuring inflammatory cytokine levels, and histopathology analysis. In addition, the ROS levels in the bacterial cells were measured with DCFH-DA detection kit. Furthermore, the potential target and detailed mechanism of the new compounds during infection disease therapy were predicted and evidenced with molecular docking. After that, ADMET characteristic prediction was completed, and novel, synthesizable, drug-effective molecules were optimized with reinforcement learning study based on the probed compound as a training template. The interaction between the selected structures and target proteins was further evidenced with molecular docking. This series of innovative studies provides important theoretical and experimental data for the development of new anti-A. baumannii infection drugs. [ABSTRACT FROM AUTHOR]

AbstractThe wet desulfurization yields slurry with a moderate temperature and stable supply and thus holds promise for waste heat utilization. However, the corrosive nature and solid particle content of desulfurization slurry from the wet desulfurization process pose potential erosion challenges in waste heat utilization heat exchangers, which is an aspect scarcely explored in the existing literature. The present study aimed to investigate the erosion characteristics in desulfurization slurry heat exchangers using numerical simulation approaches, which can offer crucial insights for practical application in low-grade energy recovery. The result identified slurry mass flow rate and composition as essential factors of erosion distribution. Higher mass flow rates enhance heat transfer efficiency. Still, paradoxically, lower flow rates lead to more pronounced erosion, with a slurry mass flow rate of 35 kg/s resulting in nearly double the erosion compared to the benchmark condition of 56 kg/s. This phenomenon is ascribed to lower fluid velocities in the heat tubes, where the influence of changed velocity diminishes, but slurry exhibits more stable flow at higher mass flow rates. Furthermore, it is also observed that both elevated solids content and particle size lead to an increase in erosion rates. The difference in erosion caused by solid particles with particle sizes in the range of 200–350 µm is marginal. The heat exchanger structure and arrangement also impact fluid flow and erosion. While the difference in fluid flow between vertically and horizontally arranged heat exchangers is negligible, the erosion was significantly reduced to 1/10 in the vertical arrangement. The no-tube-in-window heat exchangers, designed to minimize vibration, exhibit reduced heat transfer capacity alongside diminished and more uniform erosion. The augmentation of tube passes reduces overall erosion but focalizes severe erosion at the slurry inlet, which presents a potential design solution. [ABSTRACT FROM AUTHOR]

This study intends to theoretically analyze the effects of different shapes of corrugated electrolytes on cell performance. On the basis of the mesoscale electrode–electrolyte interface modification theory, corrugated electrolytes with different shapes are applied to conventional anode-supported planar solid oxide fuel cells (SOFCs). Three-dimensional models of solid oxide fuel cells with electrolytes corrugated in different shapes were developed. For the purpose of further understanding the influence mechanism of the corrugated electrolyte on the cell, we analyze the influence of the corrugated electrolyte on the overall performance of the cell. Furthermore, the local gas distribution, concentration polarization, activation polarization, exchange current density and electron current density are discussed. Results indicate that the corrugated electrolyte structure reduces the local exchange current density, while the extension of the activation reaction zone results in an increase in the overall charge transfer, which leads to the improvement of cell performance. And for different corrugated shapes, the area expansion degree of corrugated electrolyte is proportional to the degree of cell performance improvement. Under the operating voltage of 0.7 V, the average current density improvement percentage of the rectangular corrugated electrolyte with a spreading factor of 1.47 is 38.01%. [ABSTRACT FROM AUTHOR]

Leaf vein drip irrigation emitter is a new type of drip irrigation emitter. The flow channel achieves energy dissipation through flow diversion, turning, and sudden contraction. In this study, three design schemes (B1, B2, and B3) were proposed by optimizing the flow channel structure to improve the hydraulic performance, and the feasibility of the schemes was verified by combining them with experiments. The results show that the flow index of the three structural optimization designs were 0.52, 0.51, and 0.50, with errors of less than 5% compared to the measured results. Compared to the original structure A1 (with a flow index of 0.53), the hydraulic performance was improved by 0.4%, 3.2%, and 5.7%. Compared with A1 and B1, the turbulence kinetic energy of the main flow region of the B2 and B3 structures was significantly increased, and the proportion of low turbulence kinetic energy area had decreased. The increase in turbulent kinetic energy drove the liquid to remain turbulent, increasing the ability of particulate matter to flow out of the flow channel. The irregular changes in the velocity field in the high-speed zone result in a large velocity gradient, which maximizes the turbulent kinetic energy and entropy generation in the area. Among the four flow channel structures, the region with the highest turbulence dissipation was located in the upper part of the internal structure of the flow channel. There were apparent vortex regions in flow channels A1, B1, and B3 for energy dissipation, with energy dissipation coefficients being 6.07–8.51. However, the average flow velocity in this region was only about 0.2 m/s, and particulate matter was easily trapped. When the particle diameter increased, compared with the other three design structures, B2 had the best particle passage ability. Combined with the muddy water experiment, the optimized flow channel B2 anti-clogging performance improved by 30.8%. This study can provide a reference for further improving the hydraulic performance of drip irrigation emitters. [ABSTRACT FROM AUTHOR]

To achieve energy conservation and improve ship maneuverability, a new type of collaborative spoiled rudder (CSR) is proposed by absorbing the advantages of existing ship rudders. This study investigates the non-stationary characteristics of the hydrodynamic forces of CSR section in depth, and carries out structural optimization based on numerical simulations. First, the effects of rudder angle and spoiler open angles on the non-stationary characteristics of the hydrodynamic forces of the CSR, and the appropriate maximum value of the spoiler open angle is determined. The results show that the unsteady pulsation amplitude of the hydrodynamic forces of the CSR is directly proportional to the spoiler open angle and inversely proportional to the rudder angle, and the upper limit of the spoiler open angle is set to 30°. Then, the hydrodynamic characteristics of the CSR with different spoiler widths are investigated in further. The maximum lift of the CSR increases as the spoiler width increases. The target lift method is used for efficiency evaluation. The ranges of the favorable rudder angle and the favorable spoiler open angle for different CSR configurations are determined, and the optimal spoiler width is further determined based on the non-stationary characteristics of the hydrodynamic forces. [ABSTRACT FROM AUTHOR]

The use of mulch has brought great convenience to agricultural development, but at the same time, it can cause extremely serious white pollution, and there is a lack of relevant degradation treatment research. Low-temperature plasma degradation is a highly efficient and green treatment technology that degrades pollutants by generating high-energy electrons and active substances in the reaction space. Firstly, a high frequency alternating current needle plate corona discharge structure was used to optimize the design for the electrode structure. Then, the plastic film was treated by corona plasma degradation technology, and finally the effects of different discharge power, air humidity, needle film spacing and discharge spacing on the degradation of plastic film were compared. Then, the plastic film was treated by corona plasma degradation technology, and finally the effects of different discharge power, air humidity, needle film spacing and discharge spacing on the degradation of plastic film were compared. The results show that the shape and distance of the needle tip will affect the electron density and electric field intensity to different degrees, and when the slope of the needle tip is 3. 33 and the spacing between the needles is 12 mm, the electron density and electric field intensity are the largest, which are 1. 55 × 10 13m - 3 and 1. 2 × 10 6 V/ m, respectively. The increase of the discharge power will lead to the increase of the energy density in the space, thus increasing the energetic particles in the space When the input power is 64 W, the degradation efficiency is up to 0. 96 %, but the energy efficiency will increase first and then decrease with the increase of input power. When the input power is 56 W, the optimal energy efficiency is 34. 29 μg / (W·h). The increase of the air humidity not only leads to the change of the discharge form and the appearance of stable micro-discharge, but also affects the content of the active material, leading to the degradation of the film. The distance between the ground film and the tip of the needle will also lead to stable micro-discharge, which will increase the degradation efficiency from 0. 43% to 1. 02% . In addition, the distance between the electrodes of the needle plate will also have an impact on the degradation efficiency, when the distance between the discharge is 15 mm can meet both the radiation range and radiation intensity of the plasma, the degradation efficiency and energy efficiency will reach the maximum, which are 2. 3% and 68. 18 μg / (W·h), respectively. [ABSTRACT FROM AUTHOR]

An efficient, robust, and versatile optimization method (DSM-MCC-HA) is proposed for transcendental eigenvalue problems by combing the advantages of the dynamic stiffness method (DSM), mode count constraint (MCC), and heuristic algorithm (HA). The DSM is used to model free vibration, or buckling or wave propagation eigen problems exactly with very few DoFs leading to efficient computation; moreover, material and geometry are parameters in the analytical DSM models. The monotonically increasing integer-valued mode count based on the Wittrick–Williams algorithm is directly used as the constraint, and there is no need to compute the eigenvalues through dichotomy, which significantly reduces the computational time and meanwhile guarantees the robustness. Heuristic algorithms are adopted as the optimization algorithm resulting in global optima, where the differentiability of the mode count constraint is not required. The proposed method is sufficient general to be applied to different eigenvalue optimization problems, such as lightweight optimization with eigenvalue constraints, band gap constraints or specified eigenvalue(s), maximization of eigenvalue or band gaps with mass constraint, etc.. Difficulties of repeated frequencies, localized modes, and eigenmode switching are not involved. Beam (plane frame) and plate (corrugated sandwich panel) built-up structures are adopted as examples to demonstrate the efficiency, robustness, and versatility of the proposed method. [ABSTRACT FROM AUTHOR]

In order to improve the operation efficiency of low-head tubular pump, this paper studies the influence of shaft type in the shaft tubular pump on the flow characteristics and energy characteristics of the pump. To optimize the shaft structure of shaft tubular pumping systems and realize the efficient use of energy, numerical simulation and model test was employed to study the optimization of the entire pumping system. In this paper, the CFD method was used to numerically simulate the whole pumping system, and the effect of changing the shaft length, shaft head profile, and shaft tail profile on the internal flow and entropy production characteristics of the inlet passage and impeller position were analyzed. It is found that the tapered tail profile can make the inlet passage overflow area change more smoothly and thus make the flow pattern more favorable. The wall entropy production dissipation at the inlet passage position dominates the total entropy production, and the high-value area of mainstream entropy production at this position is distributed periodically. The mainstream entropy production dissipation at the impeller section accounts for a relatively large proportion. After the entropy production dissipation analysis, it is believed that the tapered can reduce the entropy production dissipation of the pumping systems. The change of the shaft tail profile will make the entropy production dissipation change more noticeable compared with other optimization factors. Therefore, the tapered tail profile with better transition in the actual project is recommended. [ABSTRACT FROM AUTHOR]

Copyright of Chemical Engineering (China) / Huaxue Gongcheng is the property of Hualu Engineering Science & Technology Co Ltd. 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.)

[Objective] To study the effects of structure optimization on the contents of total phenols, total flavonoids, carotenoids and aroma components in different parts of tobacco leaves, and to seek a tobacco planting optimization technology that can effectively improve tobacco quality, so as to provide certain theoretical and technical basis for improving tobacco aroma quality and cigarette quality. [Method] Tobacco leaf was used as material in the planting base for structural optimization treatment (the bottom 3 pieces and the top 3 pieces of tobacco were removed), and the effects of structural optimization treatment on the contents of total phenols, total flavonoids, carotenoids and aroma components in different parts of tobacco leaf were analyzed and evaluated. [Result] Structural optimization treatment increased the total phenolic and flavonoid contents in tobacco leaves. After structural optimization treatment, the total phenolic content in tobacco leaves at 6,8,12 and 14 positions was increased by 30.00%, 21.70%, 13.10% and 5.00%, respectively, compared with the control, and the total flavonoid content in tobacco leaves at 4,10 and 12 positions was also significantly higher than that of the control. A total of 22 main volatile substances were detected by SPME-GC-MS, and the structure optimization treatment effectively increased the carotenoid content in tobacco leaves. The contents of aroma substances synthesized from carotenoids as precursors were all affected by the structure optimization treatment. And the influence degree of different leaf position is different. [Conclusion] Structure optimization treatment can effectively increase the contents of total phenol, total flavone and carotenoid in cured tobacco leaves of different leaf positions, improve the quality of tobacco leaves, and significantly increase the content of aroma components, which provides a certain theoretical and technical basis for improving the aroma quality of tobacco and cigarette quality. [ABSTRACT FROM AUTHOR]

In this paper, a multi-patch weakly singular isogeometric boundary element method (WSIGABEM) for two-dimensional elastostatics is proposed. Since the method is based on the weakly singular boundary integral equation, quadrature techniques, dedicated to the weakly singular and regular integrals, are applied in the method. A new formula for the generation of collocation points is suggested to take full advantage of the multi-patch technique. The generated collocation points are essentially inside the patches without any correction. If the boundary conditions are assumed to be continuous in every patch, no collocation point lies on the discontinuous boundaries, thus simplifying the implementation. The multi-patch WSIGABEM is verified by simple examples with analytical solutions. The features of the present multi-patch WSIGABEM are investigated by comparison with the traditional IGABEM. Furthermore, the combination of the present multi-patch WSIGABEM and the particle swarm optimization algorithm results in a shape optimization method in two-dimensional elastostatics. By changing some specific control points and their weights, the shape optimizations of the fillet corner, the spanner, and the arch bridge are verified to be effective. [ABSTRACT FROM AUTHOR]

The human voltage-gated sodium channel Nav1.7 is a widely proven target for analgesic drug studies. ProTx2, a 30-residue polypeptide from Peruvian green tarantula venom, shows high specificity to activity against human Nav1.7, suggesting its potential to become a non-addictive analgesic. However, its high sensitivity to human Nav1.4 raises concerns about muscle side effects. Here, we engineered three mutants (R13A, R13D, and K27Y) of ProTx2 to evaluate their pharmacological activities toward Nav1.7 and Nav1.4. It is demonstrated that the mutant R13D maintained the analgesic effect in mice while dramatically reducing its muscle toxicity compared with ProTx2. The main reason is the formation of a strong electrostatic interaction between R13D and the negatively charged amino acid residues in DII/S3-S4 of Nav1.7, which is absent in Nav1.4. This study advances our understanding and insights on peptide toxins, paving the way for safer, effective non-addictive analgesic development. [ABSTRACT FROM AUTHOR]

The holding pole is a special lifting device for the construction of transmission towers. The optimization design model for the holding pole was established. The minimum mass was set as the optimization objective. The cross-section sizes of members, the connection modes of auxiliary members and the coordinates of the rocker joint were set the optimization variables. The allowable stress, displacement and buckling coefficient were taken as the constraining conditions. An improved sine cosine algorithm (ISCA) was proposed to carry out the size, shape and topology optimization designs of the holding pole. For the ISCA, the Lévy flight was introduced to enhance the global search ability, elite guidance strategy was applied to enhance the local search ability, and the greedy selection strategy was used to update the optimal solution. The example shows that, the ISCA can effectively solve the optimization design problems of spatial truss structures. [ABSTRACT FROM AUTHOR]

Bismuth telluride-based materials are well known for their excellent thermoelectric (TE) properties within the near-room temperature range. However, the poor thermoelectric performance of their n-type counterparts has posed a major hindrance to the application of bismuth telluride-based thermoelectric generator (TEG). In this study, a dual optimization approach was implemented. Specifically, 2D ceramic nano-sized hexagonal boron nitride (h-BN) was introduced into n-type Bi 2 Te 2.7 Se 0.3 (BTS) to enhance its performance, aligning it with p-type materials. It is indicated that ceramic h-BN decoration leads to the emergence of a high density of dislocations, which boosts the phonon scattering and reduces lattice thermal conductivity significantly. Meanwhile, a high carrier mobility is maintained to ensure an improved power factor. With the addition of moderate ceramic h-BN, the composite material achieved a ZT value of 1.1 at 400 K. The geometric configuration of TEG was optimized using finite element methods to strike the optimal balance between output power (P o u t ) and efficiency (η). Based on the structure optimization results, the predicted P o u t and η increased by 48 % and 36 %, respectively. The fabricated TEG demonstrated to achieve an efficiency of 6.4 %. This work allows the evolution from bismuth telluride-based prototype to a functional TEG advanced in room-temperature heat recovery. [ABSTRACT FROM AUTHOR]

The improvement of aero-engine performance still strongly relies on the innovation design of the single crystal turbine blades. As the single crystal blades evolve from the solid type to the double-wall film cooling structure, the cooling efficiency has been greatly improved, leading to undertake much higher inlet temperatures. However, due to the complex structures of the next-generation turbine blade, both the strength design and life assessment become much more difficult. Meanwhile, the mechanical properties at localised regions are inevitably different from those of the separately cast standard test specimens, which may seriously affect the accurate mechanical performance evaluation. In order to fill this gap, this paper presents several challenges for the industrial applications of the next-generation single crystal turbine blades, and introduces the recent progress in the fields of structural optimisation, strength life assessment, and intrinsic mechanical performance testing, which would be helpful to the development of the next-generation component. [ABSTRACT FROM AUTHOR]

Slot die coating is a common method of manufacturing electrodes for lithium‐ion batteries. In this paper, a multi‐objective optimization research on the geometry of dual‐cavity die is investigated based on the numerical simulation of lithium battery anode slurry flow combined with the surface response optimization method. First, we use the Plackett–Burman test method to screen the geometric parameters significantly affecting the optimization objective. Then, based on the Box–Behnken response surface analysis method, we determine the optimal combination of parameters. The results show that the inner cavity radius and slot gap are the main structural variables affecting exit‐velocity uniformity and die deformation. The slot gap and slot length mainly affect the inlet pressure. The coefficient of deviation of exit velocity uniformity and average inlet pressure of the optimized die structure decreased by 51.3% and 7.6%, respectively. This research provides theoretical guidance for the design of slot coating dies. Highlights: Screening significant geometric parameters using Plackett–Burman test methodology.Box–Behnken response surface analysis to determine optimal parameters.Velocity uniformity and inlet pressure increased by 51.3% and 7.6%, respectively. [ABSTRACT FROM AUTHOR]

Cam-lobe radial-piston hydraulic motors are widely used in large heavy-duty machinery as direct-drive components of hydraulic systems. Due to their extremely high output torque and power density, the wet brake equipped with the hydraulic motors are necessary to achieve ultra-high braking torque in a compact space. However, due to a large number of internal friction pairs and small fit clearance between multiple friction pairs in wet brake, the rotation of the friction pairs in non-braking state will cause large friction torque loss and obvious temperature rise, thereby leading to the thermal failure of wet brake. How to optimize the structure of friction pairs to reduce the temperature rise of wet brake in non-braking state is a persistent challenge. Existing structure optimization design approaches of friction pairs in brakes mainly focus on the structure of each friction pair, which ignore the effect of fit clearance between the friction pairs on the temperature rise of brakes. Nevertheless, the fit clearance between friction pairs is an important factor that affect the temperature rise. For that, this study proposes a two-step structure optimization design approach of friction pairs for low-temperature rise wet brake in hydraculic motor, which simultaneously considers the fit clearance between the friction pairs and the structure of each friction pair. In this approach, the design process could be divided into two steps: firstly, the influence of fit clearance between multiple friction pairs on the temperature rise of wet brake in non-braking state is analyzed and optimized by the temperature rise theoretical model; secondly, in order to further reduce the temperature rise of wet brake, the oil groove structure of each friction plate are introduced and optimized by fluid-solid-thermal coupling simulation method. By this approach, the low-temperature rise structure of friction pairs with the optimized fit clearance between multiple friction pairs and oil grooves of each friction plate. Finally, a series of experiments are conducted to verify the effectiveness of the design approach. The result show that the temperature rise of wet brake could be effectively reduced 12 % by optimizing the structure of wet brake, demonstrating that the structure optimization design approach could provide a theoretical guidance to design low-temperature rise wet brake for large torque hydraulic motors.

The possibilities of combining known techniques for optimizing the securities portfolio (SP) structure were studied. A method was introduced that enables the simultaneous use of both passive and active approaches to managing the SP structure. The combined application of these methods is based on techniques for SP diversification and searching for an SP structure that mirrors the SP structure of an index fund. The objective function was modified in order to optimize the SP structure according to the traditional “return–risk” approach. The proposed objective function, along with the security risk, describes the degree to which the desired distribution of SP shares coincides with the distribution generated using an index fund. It was established that the main properties of optimal SPs obtained with the “return–risk” approach also occur in the case under consideration.