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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.

Abstract Induction skull melting (ISM) technology could melt metals with avoiding contamination from crucible. A long-standing problem of ISM is that the low charge energy utilization and inhomogeneous fields have obstructed its application in many critical metal materials and manufacturing processes. The present work investigated the problem through the structure optimization strategy and established a numerical electromagnetic-field model to evaluate components’ eddy current loss. Based on the model, the effect of crucible and inductor structure on charge energy utilization, etc. was studied. Furtherly, the charge energy utilization was increased from 27.1 to 45.89% by adjusting the system structure. Moreover, structure modifications are proposed for enhancing electromagnetic intensity and uniformity, charge soft contact and uniform heating. The work constructed a basis for framing new solutions to the problem through ISM device structure optimization.

[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]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS 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 magnetic nozzle enhanced magnetoplasmadynamic thruster (ME-MPDT) is proposed as a modification of the conventional applied field magnetoplasmadynamic thruster (AF-MPDT). In contrast to AF-MPDTs, ME-MPDT features a reduced discharge chamber, shifting the energy injection zone from the discharge chamber to the magnetic nozzle. The majority of argon is injected directly into the magnetic nozzle via the cathode, where it undergoes ionization and acceleration. Thrust, specific impulse, total efficiency, and thrust-to-power ratio of ME-MPDT are assessed using an elastic thrust stand. Comparing ME-MPDT to the standard AF-MPDT at a discharge current of 250 A and a magnetic field of 0.15 T, it demonstrates a 20% increase in thrust and a 15% increase in discharge voltage. To understand the reason behind this performance enhancement, both thrusters are simulated using a two-temperature MHD model. The simulation model is solved by the ANSYS FLUENT. The performance boost is attributed to an increase in azimuthal diamagnetic current within the magnetic nozzle, with ME-MPDT exhibiting 25% higher azimuthal diamagnetic current compared to AF-MPDT. Under these experimental conditions, ME-MPDT achieves its best performance at a discharge current of 250 A, power input of 22 kW, and a magnetic field of 0.15 T, resulting in a thrust of 485 mN, a specific impulse of 2356 s, and a thrust efficiency of 28%. • A new structure of applied field magnetoplasmadynamic thruster is proposed. • The energy injection area is changed to the magnetic nozzle. • The performance can be improved by increasing the energy in the magnetic nozzle. • The performance boost in ME-MPDT is from higher diamagnetic current in the magnetic nozzle. [ABSTRACT FROM AUTHOR]

The mechanical vapor compression system (MVC) coupled with the evaporative-cooling condenser is an effective method to improve its high temperature adaptability. However, this hybrid systems typically use an evaporative cooler as a single-stage pre-cooling unit of condenser and is mainly designed for hot–dry climates. In this paper, based on conventional evaporative-cooling condenser configuration, three two-stage evaporative-cooling condenser systems (MVC-TSEC(A), MVC-TSEC(B) and MVC-TSEC(C)) were proposed. The MVC-TSEC(A) consists of one condenser and an indirect/direct evaporative-cooler. The MVC-TSEC(B) and MVC-TSEC(C) have two condensers (in series), which are coupled with a two-stage evaporative cooling system. The refrigerant in the MVC-TSEC(C) forms a counter-flow configuration with the outdoor air, while it is concurrent flow in MVC-TSEC(B). Subsequently, the effects of the ambient parameters and outdoor air flowrate on the three two-stage hybrid systems were analyzed comparatively based on detailed numerical models. Finally, the application potential of these hybrid systems was evaluated comprehensively in hot–humid climates. The results showed that the seasonal COP and energy-saving rate for the MVC-TSEC(C) are reached by 4.2–4.7 and 12.7–21.1 %, respectively. Moreover, the static equipment payback period of the three two-stage hybrid systems are 3.8, 3.3 and 3.0 years, respectively. [ABSTRACT FROM AUTHOR]

As a widely used equipment in continuous casting process, the installation process of ladle rotary table is complicated and requires many installation equipment. According to the practical engineering application, this paper takes the installation device as the research object, and optimizes the original structure of the installation device. SolidWorks software was used to model the overall structure of the installation device, and the established model was imported into Hypermesh for mesh division, and finally into ANSYS for finite element analysis to compare the stress and deformation of the structure before and after optimization. The results show that the stress of the optimized structure is reduced to some extent, and the practical application requirements are met. [ABSTRACT FROM AUTHOR]

The authors of the discussed paper presented an interesting study in which a moat is introduced just downstream of an overflowing levee for reducing the energy of the overflowing water. The authors investigated the effect of the geometric parameter of the moat downstream of the overflowing levee on its hydraulic characteristics and energy reduction. The Reynolds-Averaged Navier-Stokes and Volume of Fluid methods were implemented to simulate and measure water depths and flow structures in order to optimize the geometric parameters of the moat, including dimensionless depths and lengths, and then to explore the effect of downstream slope, upstream slope, levee crest length, and levee height on energy reduction. Following the turbulence model validation and mesh convergence analysis were both satisfactory, an enormous amount of numerical simulations for overflowing levees with a moat under various hydraulic circumstances were conducted. The present discussion paper shows that when the dimensionless overflow depth is less than 0.81, the ideal dimensionless length of the moat is 1.50 and the optimal dimensionless depth is 0.35, which may fulfill energy dissipation requirements while saving construction costs. Moreover, when the dimensionless overflow depth is larger, it can be beneficial to reduce downstream energy by improving the overflow levee structure, which primarily involves steepening the upstream slope, reducing the downstream slope, increasing the levee crest length, and decreasing the levee height. However, when the dimensionless overflow depth decreases, the effect of these factors diminishes gradually. [ABSTRACT FROM AUTHOR]

At present, numerous wall-climbing robots have been developed, and applied in ship manufacturing for weld detection to ensure safe navigation. Limited by rigid mechanical structure and complex detection, mostly existing robots are hardly to complete weld detection by using fluorescent magnetic particles. Based on permanent magnet adsorption, a wheeled wall-climbing robot is developed to realize the stable adsorption and flexible movement on ship wall. A detection mechanism is designed using a series and parallel flexible adaptation structure to keep cross yokes and detection area close for effective detection. A unified mechanical model is established by analyzing the angle between robot attitude and gravity, to solve safe adsorption and flexible movement for different detection conditions. Integrated the multisensor information and collaboration between control component, an automatic detection control workflow conforms to the standard process is proposed. Experiments show that the robot can move on curvature wall flexibly and stably, complete the weld detection with the standard process, and clearly display the shape and depth of the small defects (groove depth ≥ 30 μm) in standard specimen. [ABSTRACT FROM AUTHOR]

Relating the complex structures of electrodes to their charging dynamics is crucial for optimizing supercapacitors, which remains an experimental and theoretical challenge. Here, we construct a pore network model (PNM) that can be downward‐transformed into a well‐known transmission‐line model and a stack‐electrode model to describe the disordered porous structure of carbon‐based electrodes. A mathematical expression is derived using an equivalent circuit model of the PNM to quantify the relaxation times of the potential and concentration. The expression is then verified using numerical solutions based on the simplified Poisson–Nernst–Planck equations and experimental data. The structure of the PNM for experimental verification is directly extracted from a porous electrode reconstructed using a scanning electron microscopic image. A self‐driven optimization framework is proposed by coupling the derived expression with a genetic algorithm to generate an optimal porous structure that can be used to investigate the changing dynamics of the electrode. Our framework provides a general image–structure–performance optimization platform for understanding and accelerating charging dynamics in porous electrodes. [ABSTRACT FROM AUTHOR]

Tilt-duct Unmanned Aerial Vehicles (UAV) combine the high-speed efficiency of fixed-wing aircrafts with vertical takeoff and landing (VTOL) and the hover capabilities of rotary-wing aircrafts while maximizing the advantages of ducted fans in terms of noise reduction, efficiency, and safety, making it a pivotal direction for the future of aviation such as urban air mobility. This paper concentrates on the design and optimization of the primary structures of a laboratory-designed reference tilt-duct UAV. Firstly, the general data of the reference tilt-duct UAV are presented. According to the load conditions, the overall structural layout design for the wing, fuselage, and empennage is carried out, where special attention has been paid to account for the requirements of VTOL/hover and cruise flight modes. Based on the structural layout, finite element models (FEM) are established and static analyses are performed. The results indicate that the design can fulfill the structural requirements during a flight mission. Furthermore, based on the Method of Feasible Directions (MFD) algorithm, we have carried out the optimization of the composite wing box that incorporates manufacturing constraints. Via optimization, the total mass of the wing box is reduced by 38.6%, i.e., from 3.73 kg to 2.29 kg. The results indicate that the combination of composite materials with a tilt-duct configuration holds significant potential for future high-efficiency and environmentally friendly aviation. [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.)

Induction skull melting (ISM) technology could melt metals with avoiding contamination from crucible. A long-standing problem of ISM is that the low charge energy utilization and inhomogeneous fields have obstructed its application in many critical metal materials and manufacturing processes. The present work investigated the problem through the structure optimization strategy and established a numerical electromagnetic-field model to evaluate components' eddy current loss. Based on the model, the effect of crucible and inductor structure on charge energy utilization, etc. was studied. Furtherly, the charge energy utilization was increased from 27.1 to 45.89% by adjusting the system structure. Moreover, structure modifications are proposed for enhancing electromagnetic intensity and uniformity, charge soft contact and uniform heating. The work constructed a basis for framing new solutions to the problem through ISM device structure optimization. [ABSTRACT FROM AUTHOR]

Chronic total occlusion (CTO) is one of the most severe and sophisticated vascular stenosis because of complete blockage, greater operation difficulty, and lower procedural success rate. This study proposes a hydraulic-driven soft robot imitating the earthworm's locomotion to assist doctors or operators in actively opening thrombi in coronary or peripheral artery vessels. Firstly, a three-actuator bionic soft robot is developed based on earthworms' physiological structure. The soft robot's locomotion gait inspired by the earthworm's mechanism is designed. Secondly, the influence of structure parameters on actuator deformation, stress, and strain is explored, which can help us determine the soft actuators' optimal structure parameters. Thirdly, the relationship between hydraulic pressure and actuator deformation is investigated by performing finite element analysis using the bidirectional fluid–structure interaction (FSI) method. The kinematic models of the soft actuators are established to provide a valuable reference for the soft actuators' motion control. [ABSTRACT FROM AUTHOR]

The precision of trajectory tracking and stable operation with sorting merchandise are the main challenges for palletizing manipulators in different working conditions, especially in sorting glass-substrate. To ensure the adaptability of the manipulator under different working conditions, including operational efficiency, motion space, and control accuracy, the structural optimization and the motion control methods of the manipulator should be considered. In this paper, the structure optimization and tracking control of the manipulator for sorting glass substrates are studied. Firstly, considering the optimization factors including stroke speed ratio k, transmission angle γ and the sum of link-rod lengths l of the crank rocker mechanism, a structural optimization method based on genetic algorithm is applied to enhance the flexible maneuverability. Furthermore, a feedforward-feedback iterative learning control (ILC) algorithm is adopted to the high accuracy of position tracking. Finally, experimental results verify the feasibility of structural optimization and tracking control, which can be effective applied in practical engineering. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials 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.)

Microchannel heat exchangers are characterized by high heat transfer efficiency and compact volume. The accuracy of microchannel wall temperature measurement directly affects the measurement result of the heat transfer coefficient. The water bath can control the heat flux in the microchannel heat transfer experiment with good uniformity of heat flux distribution and small heat dissipation. However, there is no suitable enough method to accurately measure the wall temperature of the microchannel under the water bath method and bilateral fluid. This paper uses the CFD method to carry out the fluid–solid coupled heat transfer. The measurement errors of six wall temperature measurement schemes in the Reynolds number range from 2400 to 7200 are investigated. The flow field distribution, pressure drop, and turbulent kinetic energy characteristics of different wall temperature measurement schemes are studied. The method of measuring microchannel flat tube wall surface temperature is optimized to solve the problem under a flowing water bath with a traditional resistance temperature detector. The results show that the measurement error of wall temperature caused by the layout method can be reduced to 0.0137 K. The pressure drop and turbulent specific kinetic energy are smaller using the optimal design. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Mechanical Strength / Jixie Qiangdu is the property of Zhengzhou Research Institute of Mechanical 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.)

A wind turbine comprises multiple components constructed from diverse materials. This complexity introduces challenges in designing the blade structure. In this study, we developed a structural optimization framework for Vertical Axis Wind Turbines (VAWT). This framework integrates a parametric Finite Element Analysis (FEA) model, which simulates the structure's global behavior, with a Genetic Algorithm (GA) optimization technique that navigates the design domain to identify optimal parameters. The goal is to minimize the mass of VAWT structures while adhering to a suite of complex constraints. This framework quantifies the mass reduction impact attributable to material selection and structural designs. The optimization cases indicate that blades made from Carbon Fiber Reinforced Plastics (CFRP) materials are 47.1 % lighter than those made from Glass Fiber Reinforced Plastics (GFRP), while the structural parts are 44.8 % lighter. This work also provides further recommendations regarding the scale and design of the structures. With the materials and structural design established, future studies can expand to include more load cases and detailed designs of specific components.

As a widely used equipment in continuous casting process, the installation process of ladle rotary table is complicated and requires many installation equipment. According to the practical engineering application, this paper takes the installation device as the research object, and optimizes the original structure of the installation device. SolidWorks software was used to model the overall structure of the installation device, and the established model was imported into Hypermesh for mesh division, and finally into ANSYS for finite element analysis to compare the stress and deformation of the structure before and after optimization.The results show that the stress of the optimized structure is reduced to some extent, and the practical application requirements are met.

ObjectiveIn order to determine the strength of the special deck structure of a cruise ship, this study investigates the ultimate bearing capacity of an unconventional stepped deck used in the layout of the cruise theater.MethodsBased on the quasi-static ABAQUS method, the ultimate bearing capacity of a stepped deck is calculated and the weak positions of the structure are determined and compared with conventional deck failure modes. Meanwhile, the influence of the deck, longitudinal frame, girder web and girder panel thickness on the ultimate bearing capacity of the structure are investigated, and two structural optimization ideas are proposed: pillar reinforcement and longitudinal reinforcement.Results The results show that the failure of the stepped deck mainly occurs at the boundary of the layer with the largest height difference; the ultimate bearing capacity of the stepped deck decreases significantly compared with that of a conventional deck; and the corresponding compression displacement and collapse depth increase obviously. The ultimate bearing capacity increases with the thickness of the deck, longitudinal frame, girder web and girder panels, and the improvement effect of girder web thickness is the most significant. The ultimate bearing capacity of the structure can be effectively improved by adding struts or increasing the height of the web in the weak position of the structure.ConclusionThis study has great significance for the design and optimization of special decks for modern cruise ships.

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%.

The charging coil plays an important role in the wireless charging system system. However, there are still some problems in the design of the wireless charging coil, such as the low coupling coefficient. In order to improve the coupling effect, this paper proposes an optimized design scheme for the metal shielding layer structure of DD coil. Firstly, the influence of the structure size of DD coil metal plate on the coupling coefficient is studied by the mathematical modeling analysis. Futhermore, the maxwell simulation is used to study the metal plate coupling coefficients with varying structure sizes, addressing receiving uniformity issues. The optimal size of the shielding layer is designed for optimal magnetic coupling in wireless charging. Finally, this paper validates the feasibility of the improved metal shielding layer through experiments. The research in this paper may have a reference role in the wireless charging system of electric vehicles. [ABSTRACT FROM AUTHOR]

Railway catenary galloping, induced by aerodynamic instability, poses a significant threat by disrupting the electric current connection through sliding contact with the contact wire. This disruption leads to prolonged rail service interruptions and damage to the catenary's suspension components. This paper delves into the exploration of optimizing the catenary system's structure to alleviate galloping responses, addressing crucial parameters such as span length, stagger dropper distribution, and tension levels. Employing a finite element model, the study conducts simulations to analyze the dynamic response of catenary galloping, manipulating structural parameters within specified ranges. To ensure accurate and comprehensive exploration, the Sobol sequence is utilized to generate low-discrepancy, quasi-random, and super-uniform distribution sequences for the high-dimensional parameter inputs. Subsequent to the simulation phase, a genetic algorithm based on neural networks is employed to identify optimal parameter settings for suppressing catenary galloping, taking into account various constraints. The results gleaned from this investigation affirm that adjusting structural parameters can effectively diminish the galloping amplitude of the railway catenary. The most impactful strategy involves augmenting tension and reducing span length. Moreover, even when tension and span length are fixed, adjusting other parameters demonstrates efficacy in reducing galloping amplitudes. The adjustment of messenger-wire tension, dropper distribution, and stagger can achieve a 22.69% reduction in the maximum vertical galloping amplitude. Notably, maintaining a moderate stagger value and a short steady arm–dropper distance is recommended to achieve the minimum galloping amplitude. This research contributes valuable insights into the optimization of railway catenary systems, offering practical solutions to mitigate galloping-related challenges and enhance overall system reliability. [ABSTRACT FROM AUTHOR]

Gradient stiffened plates are widely used in aerospace, automotive, transportation and other fields for their excellent performance. Aiming at the gradient structure of gradient plate which leads to the problem of excessive computation and low efficiency of homogenization and two-scale optimization design, this paper adopts a machine learning method to build an artificial neural network with microstructure deformation parameters as input and equivalent stiffness coefficients as output, to realize the efficient prediction of equivalent stiffness. In the optimization process, this paper introduces unit design variables characterizing the deformation of the single cell to achieve explicit control of the local deformation of the gradient plate, and introduces mapping function node design variables to ensure that the local deformation of the single cell during the optimization process is consistent with the mapping function, which facilitates the decoupling of the twoscale optimization results. Numerical examples verify the effectiveness and correctness of the proposed method. [ABSTRACT FROM AUTHOR]

Enhancement of heat transfer characteristics in helical condenser coils by modifying the coil shape has been reported by many researchers. While the influence of different types of condenser coil designs on the operating performance of refrigeration machines for hot water production unit is available in the literature, there exists no published numerical or experimental analysis of the impact of geometric parameter of immersed helical condenser coil on heat transfer characteristics and water velocity distribution during water heating process, which is the subject of our article. With using CFD methodology, a numerical study was carried out to present the water velocity distribution with varying coil parameters such as pipe diameter, tube pitch, and turns number. After validating the numerical model by the experimental ones, the effect of coil parameters on water velocity distribution was examined. The results confirm that by reducing the coil pitch and increasing the tube diameter, an increase of the water velocity and a higher natural convection is obtained. On the other hand, the results indicate that with reducing the turns number, the water velocity and the heat transfer coefficient is also increasing. Indeed, the average water velocity of condenser coil with N = 11 turns is higher than the other two condenser coil structures, which presents 21.34% and 63.56% higher than that of N = 13 turns and N = 15 turns, respectively. Thus, this investigation could provide some guidance to obtain the optimum condenser coil structure for water heating process. [ABSTRACT FROM AUTHOR]

This study investigates the impacts of industrial and energy consumption structure optimization on green total factor productivity (GTFP) growth across the Beiing-Tianjin-Hebei region. Employing directional distance functions and the global Malmquist index, GTFP is measured incorporating undesired outputs. A dynamic spatial Durbin panel model examines the direct internal and indirect spillover effects of structural optimization factors on GTFP over 1998-2019, constructing metrics for rationalization and advancement. Findings reveal varied region-specific impacts and sensitivities. Industrial structure rationalization demonstrates negative localized effects while energy structure rationalization induces adverse spatial spillovers on neighbors. In contrast, advancement of both structures stimulates strong positive direct and indirect effects. As China transitions towards coordinated development and low-carbon growth, these results hold significant implications for technology strategies and policy design tailored to region-specific conditions. [ABSTRACT FROM AUTHOR]

In this paper, to address the shortcomings of the crossing structure design based on the elastic bending center method and the lack of related research, an optimization method for high-speed turnout crossing structures was proposed based on the actual elastic deformations of point and splice rails. Based on the finite element theory, the actual loading characteristics and spatial variable section characteristics of point and splice rails were fully considered, and a refined simulation analysis model of the switching system of point and splice rails in crossing areas was established. Moreover, the elastic deformation lines of point and splice rails in the nonworking state were obtained for the first time, which were consistent with actual situations. On this basis, system optimization was performed for the connecting parts of the crossing with a movable point in a high-speed turnout. In the crossing structure simulation model, the length adjustment values of the first–sixth spacer blocks between the branch line–wing and point rails and between the mail line–wing splice rails were ≤1 mm. Moreover, the lengths of the seventh–ninth spacer blocks decreased by gradually increasing amounts, and the length of the ninth spacer block decreased the most (∼6 mm). The length of the second spacer block between the point and splice rails slightly increased, but the length of the third spacer block significantly decreased by 6 mm. The length adjustment value of the distance block between the point and splice rails was smallest (0.7 mm). The calculated optimal lengths of the connecting parts of the crossing were found to be close to the empirical values used in actual manufacturing processes, and the dimension optimization patterns were completely consistent with actual situation, which validates the proposed optimization method. Thus, the proposed method can effectively improve the coordination between rails and connecting parts in crossing areas, substantially reduce internal stresses in crossing systems, and improve their assembly performance and service life. Moreover, the proposed optimization parameters can provide valuable references for the research on next-generation high-speed turnouts (400 km/h) and for improving the designs of existing high-speed turnouts. [ABSTRACT FROM AUTHOR]

In this paper, a finite element method is proposed to predict the contact pressure of the metal seal in the subsea pipeline connector with regard of the penetration load on the critical sealing surface. Further, a fast GA-ANN model is proposed on the basis of GA-ANN to optimize the sealing structure of the connector, which uses only 3–6 % of the calculation time compared to the traditional GA-ANN model. The fast GA-ANN is further coupled with NSGA-II in the multiple objective optimization of the sealing structure and the results are compared with that of the response surface methodology (RSM). In terms of the number of valid candidate points and the optimal candidate point, NSGA-II coupled fast GA-ANN model performs much better than RSM. The hydrostatic pressure tests were carried out with the optimal sealing structure by the fast GA-ANN and the results meet the design requirements very well. [ABSTRACT FROM AUTHOR]

At present, the research of soft crawling robot pays more attention to the material manufacturing, but neglects the robot modeling. The high degree of freedom of the soft crawling robot makes it more difficult to establish its motion model and analyzes its motion performance. The centimeter-level wireless driven soft crawling robot has great advantages and application scenarios in narrow space exploration. Therefore, this paper proposed a soft robot driven by magnetism to crawling inchworm. By studying the crawling behavior of inchworm and the characteristics of flexible materials driven by magnetism, the structure of the soft robot was designed and the motion model of inchworm was established. The motion model is analyzed and simulated, the structure size of the robot is optimized, and the effectiveness of the model is verified by experiments. The robot's crawling motion is realized by coupling the structure of the robot's torso and legs with the flexible magnetic film. Driven by the alternating magnetic field, the maximum motion speed of the robot is 28.24 mm/s. At the same time, the robot can also move in narrow space such as pipes, which can satisfy the centimeter-level space detection and ensure the high efficiency, providing a new idea for narrow space detection. [ABSTRACT FROM AUTHOR]

Aiming at the complexity and uncertainty of design variables of automotive front cabin cooling system, Chebyshev uncertainty analysis was applied to optimization design of front cabin cooling flow field to establish a model for reliability optimization for automotive front cabin cooling flow field range. Taking the front cabin cooling system of a car as an example, Chebyshev function was used to optimize the structure design. Selecting the average flow velocity and airflow volume of the cooler and radiator as the target thresholds, this article adopted k- ε turbulence model reliability for finite element analysis and analyzed iteration combined with Chebyshev reliability, to optimize the structure of the front cabin cooling module and improve the performance of the front cabin cooling flow field. The experimental results show that the performance of front cabin cooling flow field can be improved to some extent by increasing the front energy retaining foam section and optimizing the gap between the fan blade and the bracket. [ABSTRACT FROM AUTHOR]

Context: In this work, we designed ten new organic phenothiazine dyes bridged by different πi-spacers (PTZ1-PTZ10) of D-π-A type based on the synthesized dye CC202-III for their efficacy in dye-sensitized solar cells (DSSC) applications. To learn how various π-spacers affect their performance in DSSCs, these isolated dyes and dye-cluster systems have had their geometries, electronic structures, absorption spectra, dipole moments, and molecular electrostatic potential examined and talked about. Additionally, a number of quantization parameters that affect power conversion efficiency (PCE), including light collection efficiency (LHE), reorganization energy (λtotal), vertical dipole moment (μnormal), strength electron injection driving force (ΔGinject), regeneration driving force (ΔGreg), excited state lifetime (τ), and open circuit voltage (VOC), were calculated in order to identify the organic dyes that would be best suited for DSSC applications. Calculated results revealed that the designed dyes PTZ3, PTZ4, PTZ5, and PTZ10 exhibit a lower energy gap among all dyes compared to the corresponding CC202-III. Additionally, PTZ3, PTZ4, PTZ5, PTZ7, PTZ8, PTZ9, and PTZ10 exhibit significant red-shifted absorption spectra compared to the other dyes with a larger oscillator strength, which improves the photocurrent density of the devices. The findings thus imply that bridge modification is a workable tactic to raise DSSC effectiveness. Method: We used density functional theory (DFT) and time-dependent DFT (TD-DFT) methods to study the electronic and photovoltaic properties of the dyes designed (PTZ1–PTZ10) to assess their effectiveness in DSSCs. DFT and TD-DFT simulations are theoretically used to deeply analyze key characteristics of all organic dyes that affect open-circuit voltage (VOC) and short-circuit current (JSC) to identify structure–property relationships. [ABSTRACT FROM AUTHOR]

The air film pressure field (AFPF) of aerostatic thrust bearings significantly determines the working performance of the bearings, and the characteristics of AFPF are closely related to the bearing structure parameters. This study carried out the structure optimization of aerostatic thrust bearing based on the analysis of the AFPF characteristics. The influence law of the number, distribution and the outlet shape of the orifices, as well as the bearing diameter on the static performance of the bearing was investigated. The relationship between bearing structural parameters, AFPF characteristics and bearing static performance was established and effectively used for the structure optimization of aerostatic thrust bearing. The simulation results were verified by the experiment. The results show that the static performance analysis of the aerostatic thrust bearing based on the AFPF characteristics can effectively provide a theoretical basis for the design and optimization of the bearing structure, and improve the bearing performance. [ABSTRACT FROM AUTHOR]

A floatation nozzle can effectively transfer heat and dry without touching the substrate, and serves as a vital component for heat transfer to the substrate. Enhancing the heat transfer performance, and reducing its heat transfer unevenness to the substrate play an important role in improving product quality and reducing thermal stress. In this work, the effects of key structural parameters of the floatation nozzle on the heat transfer mechanism are systematically investigated by means of a numerical simulation of computational fluid dynamics. The findings demonstrate that the secondary vortex structure induced by the floatation nozzle with effusion holes increases heat transfer performance by 254.3% compared with the nozzle without effusion holes. The turbulent kinetic energy and temperature distribution between the jet and the target surface are affected by the jet angle and slit width respectively, which change the heat transfer performance of the float nozzle in different degrees. Furthermore, to improve the comprehensive heat transfer performance of the floatation nozzle structure, taking into account the average heat transfer capability and heat transfer uniformity, the floatation nozzle's design is optimized by the application of the response surface method. The comprehensive heat transfer performance is increased by 26.48% with the optimized design parameters. Our work is of practical value for the design of floatation nozzles with high heat transfer performance to improve product quality in industrial systems. [ABSTRACT FROM AUTHOR]

Due to the excellent film‐forming specific surface area of the disk reactor, its application in the polymer devolatilization process can greatly improve the devolatilization performance of the equipment. In view of this, the fluid volume function method in computational fluid dynamics is used to simulate the film forming performance and surface renewal performance in high viscosity zone of disk reactor. In the disk window area, the liquid film thickness becomes thinner and the surface update frequency becomes faster, indicating that the disk window has a positive effect. The devolatilization performance of five new disk structures under different operating conditions is compared and analyzed. It was found that the influence of liquid level height on film area was greater than that of viscosity and rotation speed, the porous sector disk has excellent surface renewal performance and the baffle can achieve better mass transfer efficiency at a distance of 45–60 mm from the disk. [ABSTRACT FROM AUTHOR]

The refrigerant distributor helps resolve non-uniform flow distribution issues in multi-path evaporators. Using the CFD method, this paper investigates the distribution mechanism of R410A in a centrifugal distributor under air-conditioning conditions and explores the impact of structural factors on its distribution performance. The Taguchi method is employed to identify the optimal combination of structural parameters and optimization direction for achieving distribution uniformity. Furthermore, the flow distribution characteristics of the optimized distributor are investigated under different conditions. The results show that, under the working conditions of an inlet mass flow rate of 50 kg· h −1 and an inlet quality of 0.1, the non-uniformity of the mass flow rate in the outlet branches of the optimized distributor is only 1.07 %, which represents a decrease of 7.64 % compared to the original distributor. Additionally, the non-uniformity of the outlet branch quality also decreased by 9.41 %. These findings indicate that the optimized distributor exhibits superior distribution performance. Nonetheless, the degradation of the optimized centrifugal distributor's uniform distribution performance with increasing refrigerant inlet mass flow rate and quality suggests that it is more suitable for low mass flow rate and quality conditions. [ABSTRACT FROM AUTHOR]

Timber has long been extensively employed within the construction industry as a famous, environmentally friendly, and low-carbon material. Considering that construction constitutes one of the most significant contributors to carbon emissions throughout the entire life-cycle of a building, there is an urgent desire to incorporate timber into this domain. Nevertheless, the use of timber faces inherent challenges stemming from its anisotropic nature, a result of the natural growth of timber fibers, which makes it challenging for it to function as a primary load-bearing material in coping with the various complex stresses inherent in architectural applications. Numerous designers have attempted to address this limitation through over-sized members and reinforcement at joints; however, none have satisfactorily resolved this issue in an economical manner. In this article, we introduce the Strut-and-Tie models (STM) from Graphic Statics (GS) and a topological optimization algorithm. This algorithm has the capability to generate a 'load-minimizing path' STM based on external load support conditions and the maximum structural path span. Regardless of the complexity of the initial external loads, each load transfer path in the optimized STM bears loads in only one direction, representing an optimal solution with minimal internal loads that align seamlessly with the characteristics of timber. Consequently, we endeavor to adopt this optimization algorithm to propose a structural design methodology, with the aspiration of designing structural systems that harness the unique attributes of timber perfectly and applying them to various architectural scenarios. Ultimately, we conclude that structural systems designed based on optimized STM are adaptable to diverse architectural contexts, and when applied to small-scale buildings, this method can save approximately 20% of material consumption compared to conventional timber frame structures, while in the case of mid-rise to high-rise buildings, it can lead to a material savings of approximately 5%. [ABSTRACT FROM AUTHOR]

A frustum of a cone for dimethyl ether (DME) steam reforming hydrogen production was designed, and the numerical model of DME steam reforming hydrogen production reaction system was established. The numerical model was solved by COMSOL software, the numerical results of simulation and experiment were basically consistent. By optimizing the structure of the reforming reactor, higher DME conversion rate was obtained. The influence of the cone change on the reforming reaction, and the influence of reaction conditions on DME conversion and hydrogen production were analyzed. The results showed that higher hydrogen yield and thermal efficiency can be obtained When increasing the taper within a certain range. Through structural optimization, the DME steam reforming reaction system can obtain 92.21% DME conversion and 90.54% hydrogen production rate. The highest thermal efficiency is 74.6%. [ABSTRACT FROM AUTHOR]

Pipeline inspection gauges easily become wedged in offshore and onshore small-diameter pipelines (where the outer diameter, D, of the pipe is less than 150 mm), particularly at the bends. To reveal the relationship between PIG capacity and bend curvature radius, a quantitative study on the passing capacity of PIG was conducted in this paper from three key perspectives of performance: safe application, sealing, and driving. The results demonstrate that the pipeline inspection gauge exhibits better passing capacity as the curvature radius of the bend increases. To improve the poorest passing capacity, in the case of R = 3D, different numbers of grooves are opened in the cup. The results demonstrate that the cup with 24 square grooves has a substantial impact on optimizing the passing capacity of the pipeline inspection gauge. This enhancement results in improvements in safe application performance (40.8%), sealing performance (12.22%), and driving performance (17%). This research aims to expand our understanding of blockages in small-diameter pipelines and provide a basis for optimizing the structure of the pipeline inspection gauge for small-diameter pipelines. [ABSTRACT FROM AUTHOR]