Search Results (771)

In view of the problems that the track mode accuracy of the automatic steering gear on survey ships cannot meet the requirements of hydrographic survey accuracy and the workload of manual steering is large, an intelligent auxiliary decision-making algorithm based on LSTM and multiple linear regression is proposed. By learning historical track information, marine environment information, historical steering data, hull state data, etc., it provides the helm with auxiliary operation prompt information, such as the command course and its adjustment timing (time range, area), so as to reduce the number of times the helm steers. The effectiveness of the algorithm is verified through sea trials. The results show that the number of steering times is reduced by 45.5% and the number of effective measuring points is increased by 1.5% through the algorithm in this paper. This result confirms that the algorithm can improve the operational efficiency of offshore survey tasks by optimizing human–computer interaction. Full article

This review paper explores the transformative potential of polymer composites and adhesives in reducing the weight of aircraft landing gear, thereby improving fuel efficiency and lowering emissions. The replacement of conventional metallic materials and mechanical fastenings with advanced thermoset/thermoplastic composites and adhesives can significantly enhance durability and performance in demanding operational environments. Unlike traditional fastening methods, the structural adhesives eliminate the weight penalties associated with mechanical fasteners, offering a lighter and more reliable solution that meets the rigorous demands of modern aerospace engineering. Furthermore, the review highlights a variety of manufacturing techniques and innovative materials, including bio-based polymers, self-healing materials, noobed composites, helicoid composites, and hybrid composites. The use of thermosets and vitrimers in adhesive bonding are presented, illustrating their ability to create robust and durable joints that enhance the structural integrity of landing gear systems. The paper also addresses current challenges, including recycling limitations and high material costs. Sustainability considerations, including the integration of self-healing materials, structural health monitoring systems, and circular economy principles, are discussed as essential for aligning the aerospace sector with global climate goals. Full article

This paper presents a comprehensive design approach for optimizing the pole configuration of a coaxial magnetic gear (CMG) structure with an overhang to enhance torque characteristics. Five CMG models were designed, and their characteristics were analyzed. A three-dimensional finite element method analysis was conducted to account for axial leakage flux. To efficiently explore the design space, we utilized an optimal Latin hypercube sampling method to generate experimental points and constructed a kriging-based metamodel owing to its low root-mean-square error. We analyzed torque characteristics across the design variables to identify characteristic trends and performed a parametric sensitivity analysis to evaluate the influence of each variable on the torque. We derived an optimal solution that satisfied the objective function and constraints using the design variables. The characteristics of the proposed model were validated through electromagnetic field analysis, fast Fourier transform analysis of the air-gap magnetic flux density, and structural analysis. The optimal model achieved an average torque of 61.75 Nm, representing a 21.15% improvement over the initial model, while simultaneously reducing the ripple factor by 0.41%. These findings indicate that the proposed CMG design with an overhang effectively enhances torque characteristics. Full article

Fruits and vegetables are essential for a healthy diet, providing vital nutrients and contributing to global food security. Fungal pathogens that interact with fruits and vegetables reduce their quality and shelf life and lead to economic losses and risks to human health through the production of mycotoxins. Chemical fungicides, used to control postharvest pathogens, are posing serious environmental and health risks, driving interest in safer alternative strategies. Biocontrol methods using antagonistic microbes, such as yeasts, are eco-friendly, sustainable, and the most promising, but they often have limited efficacy and specificity in diverse produce. There is growing interest in the innovative enhancement of biocontrol strategies. The present review shows that inducing, enhancing, co-application, encapsulation, and post-application treatments are common enhancement techniques, while environmental, host, and pathogen characteristics, antagonistic microbial traits, and chemical inputs are the major gearing factors for the best application methods. These methods do not involve genetic modification, which is adequate to reduce the proliferation of GMOs (Genetically Modified Organisms) while optimizing antagonistic microbial performance by promoting growth, inducing host resistance, enhancing antifungal properties, improving adhesion, and boosting stress tolerance. Most enhancers fall under groups of nutritional additives, protective carriers, growth stimulants, and encapsulants. Integrating these enhancers and best methods promises reduced postharvest losses, supports sustainable agriculture, and addresses economic losses and food security challenges. This study highlights the role of organic and natural elicitors, their application methods, their mechanisms in improving BCAs (Biological Control Agents), and their overall efficiency. This review concisely compiles recent strategies, calling for further research to revolutionize fungal pathogen management, reduce food waste, and promote responsible farming practices. Full article

Battery electric vehicles (BEVs) are gaining market share, yet range anxiety and sparse charging still create demand for hybrids with combustion-engine range extenders. Range-extender vehicles face high customer expectations for noise, vibration, and harshness (NVH) due to their direct comparability with fully electric vehicles. Key challenges include the vibrations of the internal combustion engine, especially from vehicle-induced starts, and the discontinuous operating principle. A technological concept to reduce vibrations in the drivetrain and on the engine mounts, called “FEVcom,” relies on rolling moment compensation. In this concept, a counter-rotating electric machine is coupled to the internal combustion engine via a gear stage to minimize external mount forces. However, due to high speed fluctuations of the crankshaft, the gear drive tends to rattle, which is perceived as disturbing and must be avoided. As part of this work, the rolling moment compensation system was examined regarding its vibration excitation, and an extension to prevent gear rattling was simulated and optimized. For the simulation, the extension, based on a chain or belt drive, was set up as a multi-body simulation model in combination with the range extender and examined dynamically at different speeds. Variations of the extended system were simulated, and recommendations for an optimized layout were derived. This work demonstrates the feasibility of successful rattling avoidance in a range-extender drivetrain with full utilization of the rolling moment compensation. It also provides a solid foundation for further detailed investigations and for developing a prototype for experimental validation based on the understanding gained of the system. Full article

This study explores the application of profile shift coefficients as a design strategy to eliminate the need for stepped planet gears in a specific type of planetary gear train, referred to as the AA gear train. By appropriately selecting gear tooth numbers and applying compensating profile shifts to the two central gears, it is possible to equalize their diameters, enabling the use of simple single-step spur gears as planet gears. This significantly simplifies manufacturing, may improve power branching capabilities, and reduces the cost and volume. This paper outlines the geometric and functional limitations of this approach, including the practically allowable range of profile shift values and their impact on the tooth strength, contact ratio, and potential interference. Additionally, the influence of the planet count on assembly conditions and profile shift requirements is examined. The design may offer advantages in compactness and manufacturability (for moderate gear ratios) within a single stage. However, limitations in efficiency, power branching, and self-locking—especially at high ratios—must be considered. While the method provides a viable alternative to conventional stepped planet designs in certain cases, its applicability remains constrained by profile shift limitations and system-specific design compromises. Full article

The red mullet (Mullus barbatus, Linnaeus 1758) is a commercially vital demersal species in the Eastern Aegean Sea, yet it is subjected to high fishing pressure. This study assesses the population dynamics, growth, and exploitation status of M. barbatus based on 64 commercial trawl surveys conducted between 2022 and 2024 in the Lesvos–Ayvalik region. Length-frequency data identified eight age classes, with dominant cohorts at ages 3 (26.4%) and 5 (25%). The von Bertalanffy growth model estimated an asymptotic length (L∞) of 27.9 cm and growth coefficient (k = 0.21 year⁻¹), indicating a slow growth rate. The estimated fishing mortality (F = 0.74) exceeded natural mortality (M = 0.44), producing an exploitation rate (E = 0.63) that indicates overfishing. The length at 50% capture (LC₅₀ = 10.92 cm) was substantially below the optimal biomass length (Le = 16.6 cm), highlighting gear selectivity issues. Net benefit analysis revealed optimal fishing at 50–85 m depth and during December. These findings underscore the urgent need for improved management, including gear modifications, seasonal closures, and reduced effort, to restore sustainability and protect juvenile fish in the Eastern Aegean trawl fishery. Full article

This paper presents a comprehensive analysis of contact patterns in globoid worm gears with rectilinear axial tooth profiles. Two distinct methods are employed: a CAD-based simulation, and experimental techniques including two-sheet pressure measurement films. The CAD-based method for determining the contact pattern can be successfully applied to evaluate the form, size, and position of the contact pattern. Experimental results qualitatively confirm the theoretical predictions, although measured contact areas tend to be smaller due to incomplete filling and fabrication inaccuracies. The developed models offer reliable tools for evaluating tooth contact in worm gear design, potentially reducing prototyping costs. The proposed methods establish a solid foundation for further research and improvement of contact performance in double-enveloping worm gear systems. Full article

Voltage-gated sodium channels (VGSCs) play pivotal roles in cellular function, particularly in the regulation of electrical signaling. Structural defects in these channels cause deleterious effects in a myriad of cell types, leading to various diseases, like epilepsy, cardiac arrythmias, kidney disease, and certain cancers. Over the past decade, significant efforts have been geared toward developing drugs that target the pore domains of these channels, called pore-blocking agents. This approach has seen several setbacks, commonly due to the lack of isoform-specific binding. Alternative targeting strategies are being used to reduce or eliminate the side effects of pore-blocking agents. Transgenic mouse models have proven useful in such studies, and subtype-selective inhibitors were developed. The zebrafish model system was also used to explore neurological, cardiovascular, and metabolic diseases caused by voltage-gated sodium channel dysfunction. Here, we delve into the growing literature on the structure and function of voltage-gated sodium channels, their role in epilepsy and its comorbidities, and the advancement in the use of zebrafish as a model system to explore these channels as therapeutic targets. Full article

Taking a typical carburized alloy steel for heavy-duty gears as the research object, this work regulates carburizing–quenching and tempering processes to conduct a layer-by-layer analysis of gradient-distributed microstructures and mechanical properties in the carburized layer. The effects of tempering temperature on martensite evolution, mechanical properties, and wear resistance were specifically investigated. Results demonstrate that carburizing–quenching followed by cryogenic treatment generates high-carbon martensite at the surface, progressively transitioning to lath martensite towards the core. Low-temperature tempering promotes fine carbide precipitation, while elevated temperatures cause carbide coarsening. Specimens tempered at 175 °C achieve surface hardness of 800 HV and near-surface compressive yield strength of 2940 MPa. These samples exhibit 13% lower wear mass loss compared to 240 °C tempered counterparts, demonstrating superior wear resistance characterized by relatively flat wear surfaces, uniform contact stress distribution, and reduced cross-sectional plastic deformation zones. Key strengthening mechanisms at lower tempering temperatures involve solution strengthening, dislocation strengthening, and partial precipitation strengthening from carbides. Coherent carbides formed under these conditions impede fatigue dislocation motion via shearing mechanisms to suppress plastic deformation and fatigue crack initiation under contact fatigue stress, thereby enhancing wear performance. Full article

This paper presents the design and operating principle of a mechanical device for machining a cylinder liner flange seat in a diesel engine damaged due to cavitation or wear. Mounted on the engine block, the device allows the removal of damaged material and the formation of an undercut for the installation of repair rings. The gear ratios used allow for manual driving of the device. The device allows engine repair without the need for disassembly, which provides significant economic benefits by shortening repair time, reducing repair costs, and extending engine life, which is also important for environmental protection. Full article

Industrial pump systems require real-time fault diagnosis for predictive maintenance, but conventional Chain-of-Thought (COT) reasoning faces computational bottlenecks when processing high-frequency vibration data. This paper proposes Vibration-Aware COT (VA-COT), a novel framework that integrates multi-domain feature fusion (time, frequency, time–frequency) with adaptive reasoning depth control. Key innovations involve expert prior-guided dynamic feature selection to optimize edge-device inputs, complexity-aware reasoning chains reducing computational steps by 40–65% through confidence-based early termination, and lightweight deployment on industrial ARM-based single-board computers (SBCs). Evaluated on a 12-class pump fault dataset (5400 samples from centrifugal/gear pumps), VA-COT achieves 93.2% accuracy surpassing standard COT (89.3%) and CNN–LSTM (Convolutional Neural Network-Long Short-Term Memory network) (91.2%), while cutting latency to <1.1 s and memory usage by 65%. Six-month validation at pump manufacturing facilities demonstrated 35% maintenance cost reduction and 98% faster diagnostics versus manual methods, proving its viability for IIoT (Industrial Internet of Things) deployment. Full article

The combined reducer consisting of spiral bevel gear pair and planetary gear train is widely used in the aerospace field, and its dynamic performance seriously affects the fatigue life of the gears. However, there has been little research on the dynamic performance analysis of the combined gear reducer. In this paper, the coupling multibody dynamic models of spiral bevel gear pair and planetary gear train with and without bearing modules are established based on ADAMS software, respectively, and the influence of bearings on the dynamic performance of the coupling system is studied, and the analysis results are verified by experiments. The results demonstrate that the flexible bearings in the coupled system will induce a pronounced shaft swing that amplifies the combined reducer vibration. Because of the displacement of the sun gear, the meshing force of the planetary gear train fluctuates periodically at low frequency, which increases the maximum dynamic meshing force and is not conducive to its fatigue life. This low-frequency fluctuation can be greatly reduced by introducing additional bearings. In addition, dynamic testing confirms vibration spectral components include obvious shaft rotation frequencies except gear meshing frequencies, verifying the modeling accuracy and analytical methodology. Full article

This paper deals with the design and the robustness analysis of a model predictive control (MPC) for the position tracking of primary flight movables driven by electro-mechanical actuators. This study is, in particular, focused on a rotary electro-mechanical actuator (EMA) by UMBRAGROUP, employing a patented mechanical transmission based on a differential ball-screw mechanism characterized by a huge gear ratio. To obtain a baseline reference, conventional PID regulators were initially optimized by using multi-objective cost functions based on tracking accuracy, load disturbance rejection, and power consumption. The position regulator was then replaced by an MPC regulator, designed to balance performance, computational resources, and safety constraints. A nonlinear physics-based simulation model of the EMA, entirely developed in the Matlab–Simulink environment and validated with experiments, was used to compare the two control strategies. The simulation results in both the time and frequency domains highlight that the MPC solution provides faster and more accurate position tracking, improved dynamic stiffness, and reduced power absorption. Finally, the robustness against model uncertainties of the MPC was addressed by imposing random and combined deviations of model parameters from the nominal values (via Monte Carlo analysis). The results demonstrate that the implementation of MPC control laws could enhance the stability and the reliability of EMAs, thus supporting their application for safety-critical flight control functions. Full article

The electrification of tractors can increase the self-supply of renewable energy produced on the farm and reduce the operating costs of tractors. However, electric tractors face higher upfront costs than their diesel counterparts, as well as limited operating time. A drivetrain that is highly efficient in a wide range of agricultural applications reduces operating costs and enables long operating times. Thus, we propose a method to design electric tractor drivetrain configurations that incorporates longitudinal dynamic simulations to enable the development of such efficient drivetrains. To represent a diverse application profile, we include real-world load cycles recorded from a 104 kW diesel tractor. Our investigation focuses on the axle-individual drivetrain topology (eAxle) and the central motor topology as the configurations that offer the most promising trade-off between efficiency and complexity. The design method includes the top-down design of the topology including its individual components, such as the inverter, motor, and transmission, which are varied based on the load. Our method derives drivetrains with average efficiencies of 83% for an axle-individual topology with two gears. With a 100 kWh battery, such a drivetrain enables operating times of 7.5 h when fertilizing and 2.4 h when seeding. Full article