Search Results (189)

To address the low efficiency of corn straw collection, this study aims to optimize the design of the straw shredding mechanism of corn straw harvesters. A multi-blade arrangement shredding mechanism was designed, with ANSYS 2022 employed for gas-phase flow field simulation of the pick-up and fan conveying chambers, and a multi-field coupled simulation was conducted to evaluate performance using pick-up rate and qualified cutting length rate as metrics. Field tests were carried out to validate the simulation results. The results show that the DC-type pick-up (symmetrically arranged Y-shaped and hammer claw blades) exhibited optimal performance. At a travel speed of 1.2 m/s and rotational speed of 2100 r/min, the pick-up rate and qualified cutting length rate reached 93.62% and 93.94%, respectively, in field tests (81.34% pick-up rate in simulation); its maximum collection efficiency reached 92.98% under the conditions of fan 1 speed of 2300 r/min, fan 2 speed of 4600 r/min, and single feed rate of 9.4 kg. All pick-up types had maximum forces below the stress limit (348 MPa), meeting operational requirements. This research provides reliable references for the design and optimization of corn straw returning machines and verifies the accuracy of the simulation method. Full article

The whole-stalk harvesting and baling of reeds (Phragmites australis (Cav.) Trin. ex Steud) require a header with high efficiency and low loss rate. Based on an analysis of reed characteristic parameters, this paper proposes a T-shaped layout header design for whole-stalk reed harvesting. The design employs bilateral transverse conveying chains and a longitudinal clamping conveying chain, coordinated with a baler at its end, to achieve integrated harvesting and baling of whole reed stalks, thereby improving efficiency. By analyzing the relationship between key header parameters, such as the height of the lifting lugs on the transverse conveying device, the speeds of the transverse and longitudinal conveying chains, and the forward speed of the header, and the posture of the reeds, the causes of header loss during reed harvesting with the T-shaped header are identified. On this basis, a set of design criteria for the key parameters of the T-shaped whole-stalk reed header is established. A T-shaped reed whole-stalk harvesting header was designed according to these criteria and tested in harvesting experiments with varying preset values for forward speed and lower transverse conveying chain speed. Experimental data show that under optimally matched parameters, the header achieves a low average loss rate (L_h ≤ 2.0%) and a high average harvesting efficiency at the rated forward speed (up to 1.0 hm²/h, including baling), verifying the correctness of the theoretical analysis and the design criteria. The research results provide theoretical and experimental support for the design of conveying systems in headers for tall-stalk crops such as reeds. Full article

Timely adjustment of belt conveyor speed according to the conveyed load is a key approach to achieving energy-efficient operation. Line laser-assisted vision has been widely adopted for load measurement, in which image processing techniques are employed to extract and analyze the outer contour of material piles highlighted by laser stripes. To address issues such as laser stripe thinning and breakpoint handling, the point-by-point interpolation method (PPIM) was previously proposed, enabling column-wise extraction of laser stripe pixels by incorporating the geometric characteristics of material accumulation, thereby improving real-time performance. However, its adaptability remains limited under complex pile geometries and strong reflective interference. In this paper, the pixel traversal strategy is further optimized to achieve efficient and robust extraction of the laser stripe centerline. By performing a single, non-global image traversal, laser stripe thinning, breakpoint identification, interpolation, continuity reconstruction, and cross-sectional area calculation are integrated into a unified processing framework. Experimental results demonstrate that the improved method achieves a 0.3% increase in measurement accuracy compared with the original PPIM, while maintaining excellent real-time performance with a processing speed of up to 94 frames per second (FPS). The proposed approach provides a more reliable load perception basis for intelligent speed regulation of belt conveyors, contributing to energy-efficient and stable operation. Full article

This study investigates how next-generation digital infrastructures—terahertz (THz) communication and AI-driven network orchestration—shape perceived service quality, luxury perception, and loyalty within the context of luxury hospitality. An empirical survey was conducted among 693 guests at Torre Melina Gran Meliá (Barcelona) between June 2024 and June 2025. Using a refined 38-item Likert-scale instrument, a three-factor structure was validated: (F1) Network Performance (speed, stability, coverage, seamless roaming, and multi-device reliability), (F2) Luxury Perception (modernity, innovation, and brand image), and (F3) Service Loyalty (satisfaction, return intentions, recommendations, and willingness to pay a premium). The results reveal that superior network performance functions both practically and symbolically. Functionally, it enables uninterrupted video calls, smooth streaming, low-latency gaming, and reliable multi-device usage—now considered essential utilities for contemporary travelers. Symbolically, high-performing and intelligently managed connectivity conveys technological leadership and exclusivity, thereby enhancing the hotel’s luxury image. Collectively, these effects create a “virtuous cycle” in which technical excellence reinforces perceptions of luxury, which in turn amplifies satisfaction and loyalty behaviors. From a managerial perspective, advanced connectivity should be viewed as a strategic investment and brand differentiator rather than a cost center. THz-ready, AI-orchestrated networks support personalization, dynamic bandwidth allocation (i.e., real-time adjustment of network capacity in response to fluctuating user demand), and monetizable premium service tiers, directly strengthening guest retention and brand equity. Ultimately, next-generation connectivity emerges not as an ancillary amenity but as a defining pillar of luxury hospitality in the emerging 6G era. Full article

Aiming at the reliability of ear picking and the consistency of stalk chopping length in the process of corn ear and stalk harvesting, a new type of corn harvester with both ear and stalk harvesting based on exciting ear picking was developed. Based on the vertical cutting table, the machine realizes the excitation of the ear during the process of stalk transportation by rotating the eight-edged special-shaped pick-up roll, and the stable and orderly transportation of stalks before cutting is realized by the way of clamping and conveying with the rear rollers. By analyzing the configuration and parameter determination methods of the main working parts, the high-efficiency and low-loss harvest of the ear was realized, and the consistency of the cut length of the stalk was guaranteed. A discrete element model (DEM) of ear-bearing maize plants was established using EDEM (version 2024, Altair Engineering, Troy, MI, USA) simulation software, and a five-factor, three-level quadratic orthogonal rotation experiment was conducted based on Response Surface Methodology (RSM). The simulation results indicated that the optimal operational quality was achieved under the following parameters: a header angle of 10°, a snapping roller speed of 942 rpm, a clamping roller speed of 215 rpm, and a moving blade speed of 1450 rpm. Furthermore, multiple sets of field trials were conducted at various forward speeds to validate these findings. The mean values of seed loss rate, ear loss rate, and seed breakage rate are 0.51%, 0.55%, and 0.32%, respectively, for the harvester at operating speeds of 4 km/h, 6 km/h, 8 km/h, and 10 km/h. The σ values are 97%, 98%, 97%, and 98%. The field harvesting performance indexes meet the requirements of technical specifications for evaluating the operation quality of corn combine harvester, and meet the design requirements of low loss, high efficiency, and consistency of stem chopping length. Full article

Most datasets encountered in computer vision and medical applications present symmetries that should be taken into account in classification tasks. A typical example is the symmetry by rotation and/or scaling in object detection. A common way to build neural networks that learn the symmetries is to use data augmentation. In order to avoid data augmentation and build more sustainable algorithms, we present an alternative method to mod out symmetries based on the notion of section of a principal fiber bundle. This framework allows to use simple metrics on the space of objects in order to measure dissimilarities between orbits of objects under the symmetry group. Moreover, the section used can be optimized to maximize separation of classes. We illustrate this methodology on a dataset of contours of objects for the groups of translations, rotations, scalings and reparameterizations. In particular, we present a 2-parameter family of canonical parameterizations of curves, containing the constant-speed parameterization as a special case, which we believe is interesting in its own right. We hope that this simple application will serve to convey the geometric concepts underlying this method, which have a wide range of possible applications. Full article

Current small arch shed machine designs rely on manual pole placements, resulting in low construction efficiency and mechanized levels. These machines were not designed with key components tailored to the agronomic requirements of Xinjiang’s small arch shed cotton cultivation model. An automated rod-feeding mechanism for a small arch shed was designed using SolidWorks 2023 to bridge this gap. Its major components include rod separation and conveying units, enabling the separation and orderly transportation of tunnel rods. A kinematic simulation of the conveyor rod during the transport process using ADAMS 2024.1 software was performed to examine the effects of motor speed, synchronous belt stop block height, and horizontal distance on the conveyor rod. Using MATLAB 2023a to fit the center-of-mass distance curve yields the optimal values for the parameters (motor speed = 17.57 rpm, stop block height = 16.79 mm, and horizontal distance = 103.95 mm). Bench test results confirmed the simulation performance of the device with a motor speed of 17 rpm, a synchronous belt stop block height of 15 mm, and a horizontal distance of 100 mm. The automated rod-feeding device exhibited an 80.8% feeding rate. The prototype operates stably, and this design can serve as a reference for developing automated equipment for small arch sheds. Full article

Monitoring the condition of belt conveyor idlers is critical for ensuring safe and efficient operation of industrial conveying systems. However, existing methods often suffer from limited scalability and delayed fault detection, particularly under variable environmental conditions. In this work, we propose MIRA, a transformer-based framework for monitoring idler roller anomalies, which detects and localizes faults using acoustic and vibration signals collected from low-cost sensors. MIRA employs a masked transformer-based autoencoder trained in an unsupervised manner to reconstruct normal patterns and detect deviations via reconstruction error. MIRA can also infer the fault location, enabling spatially aware anomaly detection without the need for labeled data. We validated the system on a custom-built conveyor belt testbed equipped with sensor units, each measuring sound and two-axis vibration signals. We evaluated MIRA on four types of idler faults across 14 roller locations and 6 belt speeds. The results show that MIRA achieves an anomaly detection accuracy of 98.70% and a fault localization accuracy of 96.09%, demonstrating its robustness and practical applicability in complex operational settings. Full article

An optimized extrusion process is desired for both an environmentally friendly and economically sustainable recycling process. The aim of this study is to simulate the melt conveying zone of a single-screw extruder when using contaminated polymers instead of commonly used pure materials, to optimize a mechanical recycling process, and to reduce the number of measurements needed for rheological input data by using mixing rules. Polypropylene (PP) is blended with a polyamide 12 (PA 12) grade and another PP grade to introduce polymer impurities into the material. The blends are subjected to extrusion experiments in a lab-scale single-screw extruder with pressure and temperature sensors along the barrel. An isothermal analytical simulation model is proposed using representative shear rate values and rheological mixing rules to calculate the pressure distribution along the screw channel throughout the melt conveying zone. The rheological input data for the simulation is taken from high-pressure capillary rheometric measurements, but also substituted with values derived from mixing rules. The results show that the application of the shear viscosity through mixing models yields simulated pressure values similar to those measured in the experiments. With the introduction of representative viscosity into the model, relative deviations of around 5% at certain screw speeds can be achieved. Full article

To address longstanding challenges in sea buckthorn harvesting—such as the absence of effective harvesting principles, inefficient traditional manual and semi-mechanised methods, and rising labour costs—this study developed a self-propelled harvester equipped with a reciprocating cutter. The harvester featured an optimised double-support reciprocating cutter driven by a swing ring mechanism, with its kinematic parameters and cutting speed determined through analytical analysis. A coordinated transport system, consisting of an arc-shaped branch dial wheel, a conveying device, and a hydraulic system, was also designed. Field experiments were conducted employing a three-factor, three-level Box–Behnken design of Response Surface Methodology (RSM), which enabled the establishment of a predictive mathematical model for harvesting performance. Numerical optimisation via the model yielded the optimal operational parameters: harvesting forward speed of 0.6 m·s⁻¹, a cutting speed of 1.2 m·s⁻¹, and a conveyor belt linear speed of 0.8 m·s⁻¹. With this parameter combination, the missed cutting rate was 6.72%, fruit breakage rate 4.06%, and conveyor failure rate 7.79%, all meeting mechanised harvesting standards. This research provides the essential theoretical foundation and technical solutions for harvesting equipment in the sea buckthorn industry, accelerating its mechanisation process. Full article

Shaft sinking in soft, water-rich strata frequently suffers from low cutting efficiency, cycle-time mismatches between excavation and muck removal, and weak system-level coordination. To elucidate the synergistic mechanisms governing excavation–muck removal interactions and to realize end-to-end performance gains, we investigate the East Ventilation Shaft of the Xinjie Taigemiao mining district as a representative artificial ground freezing (AGF) project. First, drawing on the mechanics of frozen ground and field monitoring, we establish a relationship model linking advance rate, drum rotational speed, cutting depth, and muck production, thereby clarifying why lower rotational speeds, moderate cutting depths, and rational traction reduce energy consumption and mitigate disturbances to the frozen wall. Next, for muck handling, we build a full-process discrete element method (DEM) model, integrate design-of-experiments with response-surface optimization to identify key factors, calibrate contact models, and select collection geometries. The results show that a graded-angle collecting structure improves pile concentration and discharge compliance; combined with a tiered chain-bucket–vertical belt–twin-skip configuration, it delivers matched cycle times and stable “gather–convey–hoist” operation. Finally, two-stage full-scale tests jointly validate excavation and muck removal, demonstrating that the proposed synergy model and optimized parameters sustain continuous, efficient performance across operating conditions. The study provides a reusable mechanistic framework and parameterization blueprint for AGF shaft design and construction. Full article

The entry is intended to define the concepts of risk communication and emergency communication. At the same time, it explains the difference not only from a communication point of view but also from a cultural one. Risk and emergency are two sociologically relevant events, and they are culturally constructed. They are events that bring about a socio-cultural change, which, in turn, is triggered by the population’s responses on the basis of the social perception of the events themselves, also conveyed by the different forms of communication. When communicating risk and emergencies, it is essential to educate people about alert and emergency systems. Above all, what they refer to and what kind of message they contain. The “warning communication” must be specific and refer exclusively to the threat to start the first phase of the communication through which it is possible to understand the type of threat and define the communication plan to be implemented later. The use of social media, which is strongly spread in digital society, allows not only rapid dissemination of information but also rapid communication and message selection (speed and content of the message are equally important). Alert and warning systems are very often linked to risk systems, since the risk from natural disasters (eruptions, earthquakes, tsunamis) or technological catastrophes (nuclear power plant explosions) follows emergency phases when the phenomenon occurs. The communication processes, in and emergency, must be able to explain, persuade but also confer an assist the political decision-maker and the decision-making process itself through an alert system (especially in the first phase), followed by continuous dissemination through the media that the digital society offers, as well as through the usual systems adopted by government bodies (for example, bulletins and news), specialized research institutions and institutes with information and communication functions. In risk and emergency management, information and communication are to be considered, respectively, a basic element and a means of dissemination and training to educate the population to perceive a risk, to recognise emergencies and the possible impact of the risk. Differences will be expressed and analysed with reference to international examples. Full article

The loading rate of coal is significantly influenced by the number of vanes on shearer drums. However, in actual production, 1400 mm diameter drums feature two-vane and three-vane designs, while 2240 mm diameter ones have three-vane and four-vane designs, with the vane number corresponding to the optimal coal-loading rate remaining unclear. To reveal the correlation between vane number and coal-loading rate for such drums, parameters were calibrated through multiple physical tests in this study. Supported by field data, simulation analyses were conducted via the discrete element method to investigate the effect of the vane number on the drum coal-loading rate under different moisture contents and traction speeds. The results indicated that particle adhesion initially increases and then decreases with the moisture content, with the peak characteristics influenced by the particle size. Particle movement during drum coal mining is jointly governed by multiple factors. For 1400 mm drums, two or three vanes should be selected depending on moisture fluctuations and coal transportation requirements, whereas for 2240 mm drums, three or four vanes are recommended based on the balance between coal-cutting volume, conveying capacity, and traction speed. Full article

Thermal properties significantly affect extrusion energy efficiency and polymer processing. Relevant parameters include melt temperature, viscosity, and specific heat impact energy consumption, while thermal degradation limits processing temperatures within the screw and barrel. Traditional empirical methods used in polymer extrusion are often hindered by the complex relationship between screw speed and energy efficiency. Numerical simulations, particularly those using ANSYS Polyflow, offer a more precise approach for visualizing temperature, pressure, and shear rate distributions in the molten polymer, enabling better control of extrusion conditions. The screw’s geometric configuration, which includes sections for conveying, compressing, kneading, and mixing, plays a key role in determining flow behavior and performance. Studies on polymers using various screw configurations have revealed that screw designs with lower compression ratios enhance throughput and reduce melt temperature. Additionally, barrier screw designs improve the polymer melting efficiency. In this study, ANSYS Polyflow simulations were applied to analyze the flow behavior of molten PVC in a counter-rotating twin-screw extruder, focusing on the effects of screw speed and inlet flow rate on pressure, temperature, and velocity distributions. The results indicated optimal extrusion conditions for preventing degradation, with an ideal outlet rate of 439 kg/h at a screw rotational speed of 43 rpm. The pumping pressure of molten PVC by a twin-screw approach would be enough for entering the extrusion die. Full article

Typical fertilizer applicators are often restricted in performance due to non-uniformity in distribution, required labor and time intensiveness, high discharge rate, chemical input wastage, and fostering weed proliferation. To address this gap in production agriculture, an automated variable-rate fertilizer applicator was developed for the cotton crop that is based on deep learning-initiated electronic control unit (ECU). The applicator comprises (a) plant recognition unit (PRU) to capture and predict presence (or absence) of cotton plants using the YOLOv7 recognition model deployed on-board Raspberry Pi microprocessor (Wale, UK), and relay decision to a microcontroller; (b) an ECU to control stepper motor of fertilizer metering unit as per received cotton-detection signal from the PRU; and (c) fertilizer metering unit that delivers precisely metered granular fertilizer to the targeted cotton plant when corresponding stepper motor is triggered by the microcontroller. The trials were conducted in the laboratory on a custom testbed using artificial cotton plants, with the camera positioned 0.21 m ahead of the discharge tube and 16 cm above the plants. The system was evaluated at forward speeds ranging from 0.2 to 1.0 km/h under lighting levels of 3000, 5000, and 7000 lux to simulate varying illumination conditions in the field. Precision, recall, F1-score, and mAP of the plant recognition model were determined as 1.00 at 0.669 confidence, 0.97 at 0.000 confidence, 0.87 at 0.151 confidence, and 0.906 at 0.5 confidence, respectively. The mean absolute percent error (MAPE) of 6.15% and 9.1%, and mean absolute deviation (MAD) of 0.81 g/plant and 1.20 g/plant, on application of urea and Diammonium Phosphate (DAP), were observed, respectively. The statistical analysis showed no significant effect of the forward speed of the conveying system on fertilizer application rate (p > 0.05), thereby offering a uniform application throughout, independent of the forward speed. The developed fertilizer applicator enhances precision in site-specific applications, minimizes fertilizer wastage, and reduces labor requirements. Eventually, this fertilizer applicator placed the fertilizer near targeted plants as per the recommended dosage. Full article