Search Results (6,541)

Mechanized harvesting in the industrial tomato sector is currently bottlenecked by excessive mechanical injuries and elevated levels of foreign materials generated during electro-mechanical combine harvesting operations. To combat these limitations, this comprehensive review explores recent breakthroughs in harvester-mounted smart grading systems engineered specifically for complex, open-field conditions. Rather than relying solely on conventional optical inspection, the study examines the transition toward advanced, heterogeneous edge-computing frameworks—incorporating FPGAs and embedded GPUs—deployed within electro-mechanical harvesting platforms. This architectural evolution plays a crucial role in mitigating unpredictable processing delays caused by intense operational vibrations, although achieving absolute real-time stability under extreme field conditions remains an ongoing challenge. To minimize bruising and physical deterioration, our analysis synthesizes findings from multi-scale explicit dynamic finite element simulations, unpacking the underlying microstructural failure modes of the crop. We illustrate how regulating applied forces via soft robotic effectors can help approach a ‘damage-free’ handling threshold, though empirical results vary depending on fruit maturity and dynamic operational speeds. Furthermore, coupling multi-modal sensor fusion with Convolutional Neural Networks (CNNs) shows promising potential for non-destructive internal property evaluation under the vibration, dust, and throughput constraints of electro-mechanical harvesters, pending broader validation across diverse field datasets. Ultimately, by projecting future trends in onboard electro-mechanical harvester separation and advocating for a closer synergy between agronomic practices and machine engineering, this paper delivers a comprehensive blueprint for building next-generation, highly resilient, and gentle sorting machinery. Full article

The Antarctic stratospheric ozone plays a crucial role in the polar climate system and is strongly influenced by energetic particle precipitation. Among these processes, medium-energy electron (MEE) precipitation enhances the production of odd nitrogen (NOx) in the polar mesosphere and stratosphere, thereby driving ozone depletion through catalytic reactions. However, quantifying its atmospheric impact remains challenging, largely because the spatial and temporal variability of MEE is poorly constrained, and most current global chemistry–climate models lack a realistic MEE forcing. This study employs the Whole Atmosphere Community Climate Model coupled with Sodankylä Ion Chemistry (WACCM–SIC) to investigate the influence of MEE precipitation during 2013–2014, when moderate geomagnetic storms were more frequent in the winter of 2013. A control simulation (Case1) and two sensitivity experiments (Case 2 and Case 3) were conducted to isolate MEE-driven effects. Model-simulated NO_x (NO + NO₂) and ozone concentrations agree well with satellite observations, indicating that WACCM–SIC captures the key photochemical and dynamical processes. The results further suggest that the direct impact of MEE precipitation on the middle and lower atmosphere during winter is relatively weak. Nevertheless, MEE-generated NO_x can be efficiently transported downward within the polar vortex, reaching altitudes below 15 km. In these regions, MEE-related NO_x enhancement can reach up to 5%, with values during the winter of 2013 approximately twice those in 2014. Sensitivity experiments further reveal that enhanced NO_x leads to pronounced ozone depletion in the lower stratosphere, with ozone losses reaching up to 25%. A clear negative relationship between NO_x and ozone is therefore evident, highlighting the importance of accurately representing MEE precipitation in chemistry–climate models. Full article

Flanged connections are a critical joining method in modern industrial production, making the detection of bolt loosening in flanges a vital step to ensure industrial safety. Current research on bolt loosening detection in flanges mainly focuses on flat-face flanges without gaskets, while studies on bolted pipe flanges containing gaskets are relatively limited. To achieve bolt loosening detection in such gasketed pipe flanges, this paper analyzes the influence of bolt loosening on wave propagation in the gasket based on the stress wave principle and finite element simulation, and employs the hammer impact method to realize the detection of bolt loosening degree in pipeline flanges. The optimal knock force and hammer head material for the bolt loosening detection experiments were determined experimentally. Through comparative experiments, the Support Vector Machine—Recursive Feature Elimination (SVM-RFE) model was identified as being more accurate and efficient in assessing the degree of bolt loosening. Furthermore, the model was optimized by incorporating feature enhancement and cost-sensitive learning, thereby providing a reliable methodological solution for the rapid identification of bolt loosening severity in pipeline flanges. Full article

The advent of robotic surgery has revolutionized multiple medical fields, notably in urology, gynecology, and both general and cardiovascular surgery. This article aims to explore the journey of robotic-assisted surgery (multi/single-port) in abdomen and pelvic surgeries, tracing its historical roots, examining its current landscape, and considering the potential future impact. A comprehensive review of the literature was conducted through PubMed/MEDLINE, utilizing keywords such as “robotic surgical systems,” “robotic surgery devices,” and “robotics AND urology.” Reference lists from selected articles were also explored to ensure a broad scope of understanding. The focus was on robotic systems designed for laparoscopic urological surgeries, all of which have been granted regulatory approval for clinical use. The historical trajectory of robotic surgery is traced back to the late 1980s with early systems like the Probot^®, preceding the transformative introduction of the daVinci^® system in the early 2000s. In addition to daVinci^®, the article introduces newer robotic platforms, including Senhance^®, Revo-I^®, Versius^®, Avatera^®, Hinotori^®, Edge^®, Shurui and HugoTM RAS, which are emerging as serious competitors. While daVinci^® has been the dominant force in robotic surgery for over a decade, these new systems are making significant strides with innovative designs, enhanced precision, and improved cost-efficiency. The growing competition among these platforms promises to expand their potential applications, increase accessibility, and optimize surgical outcomes across various specialties. Furthermore, as new technologies continue to evolve, there is a clear need for more extensive clinical trials and real-world data to assess their long-term impact on surgical practices, healthcare delivery, and patient outcomes. It remains to be seen how these advanced systems will integrate into healthcare infrastructures and their ultimate role in shaping the future of minimally invasive surgery. Full article

Proton exchange membranes (PEMs) are essential for PEM fuel cells, with proton conductivity arising from the hydration-induced ionic channel network. PEM performance can be enhanced through pretreatments, such as annealing, which reconstruct the ionic channels. This study investigates the ionic channel network variation in Nafion 212 under continuous annealing at 90 °C using current-sensing atomic force microscopy (CSAFM). A nanoscale PEM fuel cell was formed with a Pt-coated CSAFM tip and Pt-coated Nafion surface. Topography and surface roughness analyses revealed geometrical changes from annealing. Current-sensing images and histograms qualitatively assessed local conductance and ionic channel distribution. The ionic channel network density was quantitatively evaluated using the number of protons moving through the ionic channel network (NPMI), derived from CSAFM and electrodynamics principles. NPMI directly reflects ionic channel density. From the unannealed state to 60 h, NPMI increased linearly at 1 × 10⁴ h⁻¹, indicating enhanced channel formation. Beyond 60 h, NPMI decreased linearly at 1.9 × 10⁵ h⁻¹, reflecting progressive network degradation. As the ionic channel network increases, the number of protons reaching the membrane surface also increases, whereas in the opposite case it decreases. Thus, NPMI becomes evaluation criterion for ionic channel network density. These findings systematically link nanoscale structural changes to ionic channel reconstruction and proton transport in Nafion 212, providing insight into PEM performance evolution under thermal treatment. Full article

Urban trees are increasingly exposed to persistent anthropogenic drivers that extend beyond climatic forcing and fundamentally alter the conditions of secondary growth. While climatic controls of cambial phenology and xylogenesis are well established, the mechanisms by which non-climatic drivers regulate cambial activity and wood formation remain fragmented and are often inferred only indirectly. Here, we develop a cambium-centred framework to synthesise current evidence on how anthropogenic drivers shape wood formation in urban and peri-urban trees. To our knowledge, this is among the first syntheses explicitly linking anthropogenic drivers to distinct stages of xylogenesis. Anthropogenic drivers are typically chronic, spatially heterogeneous, and temporally decoupled from seasonal climatic rhythms, and may alter cambial kinetics and generate anatomical signatures not captured by ring width alone. We evaluate major driver domains, including root-zone constraints, altered hydrology, urban microclimate, pollution, salinity, and mechanical disturbance, while also considering emerging drivers such as artificial light at night and microplastics. Evidence is stratified into three levels: direct observations, indirect physiological evidence, and mechanistic plausibility. Across driver classes, three recurrent anatomical patterns emerge: reduced conduit size under hydraulic or osmotic stress; anomalies in wall deposition under carbon limitation or oxidative stress; and pronounced circumferential heterogeneity under spatially localised forcing. Integrative approaches combining xylogenesis monitoring, quantitative wood anatomy, dendrometer observations and spatially explicit sampling are essential to disentangle anthropogenic from climatic effects and improve assessment of tree resilience. Full article

Solid–liquid transport pumps are widely used in slurry conveying, deep-sea mining, and sediment-laden water delivery, where suspended particles substantially modify internal flow behavior, energy transfer, and operational stability. This review systematically summarizes recent progress on flow evolution and stability issues in centrifugal pumps and related particle-laden pump systems. The fundamental mechanisms of particle dynamics are first discussed, including single-particle transport and force response, particle collision and agglomeration, turbulence modulation by particle assemblies, and wake-induced local disturbances. On this basis, the review further examines particle-induced changes in global flow topology, local separation and backflow, leakage shear layers, and the evolution of representative vortex structures, with particular attention to the enhancement of flow unsteadiness. In addition, the influences of particle size, concentration, density, and shape on hydraulic performance, wear failure, and operational reliability are summarized, together with recent advances in stability evaluation and fault diagnosis. Although substantial progress has been achieved, current studies still show limitations in cross-scale correlation, unified mechanism interpretation, and life-cycle coupled analysis. This review provides a useful reference for understanding solid–liquid two-phase flow mechanisms and for improving anti-wear design and stable operation control of transport pumps. Full article

The Yellow River Delta, a young alluvial plain in China, is experiencing severe land subsidence that threatens its ecological security and sustainable development. However, the driving mechanisms of this subsidence exhibit strong spatial heterogeneity, which traditional global models fail to capture. This study integrates high-precision subsidence measurements from Sentinel-1A imagery and SBAS-InSAR technology (2017–2023) with multi-source environmental factors (topography, geology, land use, precipitation) to propose a Spatially Adaptive Ensemble Learning Model with feature selection (SA-GSE). The model concatenates predictions from base learners (CatBoost, XGBoost, Random Forest) with spatial features (e.g., distance to salt pans, local topographic variance) to form meta-features, which are then input into a multilayer perceptron meta-learner. Through 5-fold spatial cross-validation, SA-GSE learns spatially dynamic base-model weights, implicitly adapting to regional variations in subsidence drivers. The model achieves an R² of 0.7810 and RMSE of 40.55 mm/yr on the test set, outperforming individual base models and ordinary stacking. Residual spatial autocorrelation is substantially reduced, with SA-GSE yielding the lowest Moran’s I (0.0334, p = 0.206) among all evaluated models, confirming effective capture of spatial heterogeneity. Driving force analysis reveals that distance to salt pans is the most important predictor (permutation importance: 0.4456), underscoring the dominant role of brine extraction-induced aquifer compaction. Lagged precipitation importance (0.3191) exceeds that of current precipitation (0.2453), indicating a recharge lag effect. SHAP interaction analysis uncovers a nonlinear “precipitation decoupling” mechanism in salt pan areas, where high precipitation paradoxically exacerbates subsidence. The resultant map of predicted subsidence rates highlights elevated rate zones in the northern salt pans and along the Guangli River. While the map does not represent a full risk assessment—as it does not include exposure or vulnerability—it provides a spatially explicit estimate of hazard likelihood. This ensemble framework yields novel perspectives on subsidence drivers in heterogeneous regions and can support land subsidence prevention and groundwater management planning. Full article

Semi-prefabricated and prefabricated concrete construction is today widely accepted as the standard method for industrial facilities, warehouse halls, and similar structures. In addition to such buildings, increasing attention has recently been given to prefabricated construction of residential buildings using load-bearing prefabricated walls. System simplicity, rapid construction, efficient site organization, and robust load transfer have stimulated the development of multiple systems and technologies, mainly differing in panel infill and connection type. In all these systems, panel connections represent the key structural detail. The connections must transfer all foreseeable forces, but their number and complexity must not be excessive, so as not to compromise the fundamental advantages of this construction method. This paper presents a review of the current state of knowledge on the behavior of prefabricated concrete wall panels and their connections by analyzing the results of numerical and experimental investigations. Current codes and guidelines relevant to prefabricated wall systems are reviewed in the context of design and construction practice in Europe and worldwide, showing that they are largely based on general recommendations rather than explicit design provisions. Key disadvantages of existing models and areas requiring additional experimental validation and numerical model calibration are identified. Finally, the study contributes to a better understanding of the factors that affect the reliability and cost-effectiveness of prefabricated wall panels in the building industry. Full article

Nanobubbles (NBs) are emerging as a promising area of research across multiple scientific and industrial domains due to their unique physicochemical characteristics. NBs exhibit distinctive properties compared to normal bubbles, including high internal pressure, a large specific surface area, high interfacial activity, and long-term stability in liquids. Therefore, NBs have gained increasing attention as a novel enhanced oil recovery (EOR) technique, offering potential advantages over traditional gas flooding and chemical flooding. CO₂-NB specifically represents a particularly promising approach as an intersection of EOR and carbon capture, utilization, and storage (CCUS), as CO₂-NB enables hydrocarbon recovery and in situ CO₂ utilization and storage at reservoir conditions. This paper presents a structured comparative discussion of currently identified experimental EOR studies that employ CO₂-NBs. Based on the observations of these experiments, this paper discusses the proposed mechanisms in those experiments or other studies that could scientifically play a role in achieving incremental recovery. The main mechanisms discussed include interfacial tension reduction, wettability alteration, CO₂ transfer from NBs into the oil liquid phase, and suppression of gravity segregation. Other possible contributors discussed in the literature include buoyancy-assisted mobilization, induced shock waves, and drag force reduction. These mechanisms are examined in relation to the distinctive properties of CO₂-NBs, showing how these properties contribute to the occurrence of the proposed mechanisms, showcasing the potential of CO₂-NBs as an emergent EOR–CCUS technology. A preliminary probabilistic assessment was performed to estimate CO₂ storage potential during CO₂-NBs EOR injection. The results suggest that the majority of the injected CO₂ is dissolved in the saturated liquid phase, while the amount of free NBs is negligible, indicating that CO₂-NB injection may provide secure storage through solubility trapping, but with lower storage capacity compared to conventional geological sequestration in saline aquifers. Full article

Plunger pumps are widely used in high-pressure and high-flow applications and exhibit strong adaptability to different fluid media. In addition to the interaction between the valve and the fluid, a potential coupling effect may exist between the flow characteristics of the pump and the electromagnetic characteristics of the motor. To investigate the electromagnetic–mechanical–hydraulic coupling effect in a motor–pump system, a transient coupled dynamics model integrating electromagnetic fields (EMF), multi-body dynamics (MBD), and computational fluid dynamics (CFD) is developed. The motion of the valve is incorporated into the model through dynamic mesh and user-defined function (UDF) techniques. The different physical models are coupled through torque, speed, force, and displacement. Based on the proposed model, the coupling characteristics of the system are analyzed. The results show that pulsating components associated with the reciprocating frequency appear in both the rotational speed and torque of the motor, resulting in fluctuations of approximately 2.11% in speed and 29.57% in torque. These pulsations are also reflected in the stator current spectrum. In addition, the valve motion at different crank angles and the flow patterns in the pump chamber are analyzed. The electromagnetic characteristics of the motor have a limited influence on the internal flow behavior of the pump. Full article

CH₃NH₃PbBr₃ (MAPbBr₃) single crystals have shown great potential in X/γ-ray detection. However, stable electrodes for MAPbBr₃ single crystals still remain challenging. In this work, multi-layer electrodes including Au, Au/Ti and Au/Pt/Ti are investigated. Through I-V characterization, Au/Pt/Ti shows Ohmic contact behavior and the lowest dark current. The potential contact is also confirmed by the Kelvin force probe. Based on these low-noise electrodes, 59.5 keV monochromatic X-ray photon-counting detection and imaging is demonstrated. This work provides useful information for electrode design in lead halide perovskite-based optoelectronic devices. Full article

Under ideal trapezoidal back electromotive force (EMF) conditions, a brushless direct current (BLDC) motor can produce constant instantaneous electromagnetic torque when supplied with ideal three-phase square-wave currents. However, this operating mode may result in relatively high copper loss. In practical applications, where both the back-EMF and the current waveforms deviate from their ideal shapes, significant torque ripple is introduced. To address these issues, this paper proposes a maximum torque per ampere (MTPA) control strategy for BLDC motors based on zero-sequence current injection. An improved Park (3s–3r) is employed to develop the mathematical model, in which the synthesized non-zero-sequence components are mapped exclusively onto the q-axis. By properly regulating the d-axis and 0-axis reference currents, the proposed strategy achieves minimum copper loss operation. Based on this framework, a torque control system incorporating zero-sequence current injection is established to further enhance performance. The feasibility and effectiveness of the proposed control strategy are validated through digital signal processing (DSP)-based experimental results. Full article

Injection operations are critical in subsurface energy engineering, where wellbores endure complex thermo-hydro-mechanical (THM) coupling under high-temperature and high-pressure conditions, impacting tubing string stability and wellbore long-term safety. Current tubing string THM research relies on simplified assumptions, focusing on single/dual-field coupling without full-scale modeling, failing to accurately characterize comprehensive multi-field behaviors or actual structural stress distributions. This paper presents a full-scale THM coupled numerical model for actual injection conditions, taking real wellbore structures as the object to realize unified modeling of tubing, packer, casing, cement sheath and formation, covering the entire well section and synergistically describing fluid flow, heat conduction and structural mechanical response. It considers fluid pressure/temperature effects on tubing axial load, thermal stress and deformation, as well as nonlinear boundary conditions like packer-casing contact and friction. The governing equations are discretized via the finite element method and solved by Newton iteration. Benchmark verification shows the maximum relative errors of casing inner/outer wall Mises stress vs. analytical solutions are 2.43% and 4.98%, confirming high accuracy. Systematic analysis of displacement, axial force, stress and temperature responses under typical conditions is conducted, providing reliable theoretical and technical support for wellbore structure optimization, injection parameter regulation and long-term wellbore integrity evaluation. Full article

Multijunction solar cells employing a GaInP/GaAs/Ge triple-junction configuration are the dominant technology for space photovoltaic applications. The choice of an efficient electrode is crucial in solar cells, as it enables effective charge carrier collection and transport while allowing maximum light to reach the active layer. Indium tin oxide (ITO)/graphene hybrid electrodes have emerged as smart transparent conductors offering significant advantages over conventional brittle ITO films. Graphene electrodes were prepared by cold-wall chemical vapor deposition and ITO electrodes were commercially obtained and used as a base for hybrid ITO/graphene electrodes. Raman spectroscopy confirmed the successful integration and characteristic G and 2D bands on the ITO surface. Nanoscale current mapping via Tunneling Atomic Force Microscopy (TUNA-AFM) verified continuous conductive pathways throughout the film with ~60% increase in nanoscale tunneling current at graphene/ITO interfaces, indicating improved local charge transport pathways. These results demonstrate the suitability of ITO/graphene hybrid electrodes a promising material for multijunction solar cells and other aerospace technologies. Full article