Search Results (33,166)

This study evaluated the technical viability and thermodynamic performance of an open-loop upcycled heat pump dryer, repurposed from a decommissioned window-type air conditioner, for thin-layer red dragon fruit (Selenicereus costaricensis) drying. Experiments were executed at 50 °C under controlled air velocities (0.5, 1.0, and 1.5 m/s), using open-sun drying as a control. Mathematical modeling revealed that the Wang and Singh model best described the drying process ($R^2$: 0.996368–0.999539). Accounting for volumetric shrinkage via equivalent average thickness (L_eq = 0.75 L₀), corrected effective moisture diffusivity (D_eff) ranged from 1.194 × 10⁻⁹ to 3.138 × 10⁻⁹ m²/s, while convective mass transfer coefficients ($h_m$) ranged from 5.241 × 10⁻⁷ to 1.880 × 10⁻⁶ m/s, both peaking at 1.5 m/s due to thinned concentration boundary layers. Thermodynamic assessments showed a maximum COP_hp of 3.41 at 1.0 m/s and a maximum SMER of 0.231 kg/kWh at 1.5 m/s. Individual statistical analysis of L*, a*, and b* parameters confirmed no statistically significant differences (p > 0.05) between heat-pump-dried and fresh samples. Concurrently, a remarkably low descriptive total color difference (ΔE = 1.24) was obtained, compared to open-sun drying (ΔE = 16.22), confirming high color retention. These findings highlight e-waste upcycling as an efficient and sustainable agricultural solution. Full article

Cavitation represents a critical phenomenon affecting the performance, durability, and acoustic signature of high-speed propellers. This study extends a previous non-cavitating analysis of the same propeller by investigating cavitation onset, evolution and performance change for a 140 mm diameter, three-blade fixed-pitch high-speed propeller. The Rayleigh-Plesset cavitation model, implemented in ANSYS CFX 24.2 within a two-phase Eulerian framework coupled with SST turbulence closure, was used to simulate 72 operational combinations spanning six advance velocities (0–10 m/s) and twelve rotational speeds (300–3600 RPM), with nine representative cases analyzed in detail. Results show that onset thresholds are strongly velocity-dependent: at zero advance velocity (bollard-pull condition, v = 0 m/s) cavitation inception occurs between 1800 and 2000 RPM, whereas at high advance velocity (v = 10 m/s) localized tip-vortex cavitation appears at rotational speeds as low as 300 RPM despite a nominally favourable global cavitation number (σ = 1.96), demonstrating that the global cavitation number alone cannot predict the onset of cavitation. Cavitation consistently initiates at blade tip leading edges, evolving from attached sheet cavitation to supercavitation with vapor fractions exceeding 95% at maximum conditions. At the critical design point, propulsive efficiency reaches η = 38.6% (T = 244.04 N, Q = 12.08 Nm). A direct comparison with the non-cavitating baseline reveals that this effect is regime-dependent: cavitation reduces predicted thrust by 7–11% under bollard pull conditions (v = 0 m/s, 1800–3600 RPM), partially attributable to active-blade-area loss; at moderate advance velocities (v = 2–6 m/s) the two predictions nearly coincide, while at high advance ratio (v = 8–10 m/s) cavitating thrust matches or exceeds the non-cavitating prediction, by up to 88% at v = 10 m/s and 3600 RPM. These findings define indicative operational envelopes, identify blade tip protection as essential for erosion mitigation and provide practical design guidance for high-speed propellers in fast vessels, rescue craft and autonomous surface vehicles. Full article

Landslide susceptibility assessment is essential for hazard mitigation and sustainable urban planning, yet many existing approaches rely primarily on static environmental predictors and often neglect active slope deformation. This limitation is particularly relevant in rapidly urbanizing areas, where human activity may destabilize slopes and reactivate dormant landslides. This study develops a process-informed susceptibility framework that integrates LiCSBAS-derived SBAS-InSAR deformation into a MaxEnt model for the urban and peri-urban residential areas of Cluj-Napoca, Romania. Two comparative models were implemented: (i) a baseline model using conventional conditioning factors and (ii) an enhanced model incorporating Sentinel-1 LOS velocity derived from SBAS-InSAR time-series analysis (2020–2023). The study quantitatively evaluates the predictive value of deformation-informed susceptibility modelling under single-orbit InSAR conditions, independently validates velocity data using EGMS observations, and constitutes the first integration of InSAR-derived ground deformation into landslide susceptibility assessment for Cluj-Napoca. Results show moderate-to-strong agreement between SBAS and EGMS deformation data (Pearson correlation ≈ 0.7). Incorporating LOS velocity improved model performance (AUC from 0.809 to 0.833; p < 0.001) and increased the spatial correspondence between mapped landslides and high- and very high-susceptibility zones. The integrated framework enabled the identification of localized active instability zones and provided a practical basis for hazard-informed urban planning and land management. Full article

Accurate binarization of phase-detection probe signals (gas vs. liquid) is necessary for the estimation of local void fraction, interfacial velocity, and bubble statistics in gas–liquid flows, particularly in nuclear thermal–hydraulic experiments. Classical threshold-based methods—single or double level—perform well on clean laboratory signals but degrade under realistic industrial conditions where noise, baseline drift, and clustered (slug-like) events challenge fixed rules. This work investigates whether deep learning (DL) models trained exclusively on synthetic data can deliver robust, generalizable binarization on real probe measurements. We (i) build a parametric generator of realistic time series from bubbly pulse templates, extended to clusters/slug patterns and perturbed with controlled noise, drift, and oscillatory baselines; (ii) train four lightweight DL architectures—one-dimensional U-Net (UNET-1D), Temporal Convolutional Network (TCN), a minimal one-dimensional Convolutional Neural Network (CNN-1D), and a Bidirectional Long-Short Memory network (BiLSTM)—only on synthetic signals; and (iii) evaluate them against classical threshold methods using event-level and sample-level metrics. On synthetic signal evaluation, UNET-1D and TCN achieve near-perfect event detection and sub-millisecond onset errors. On real bubbly and slug flow sensor data, classical threshold-based methods remain highly competitive on clean sensor signals, while DL models retain advantages under non-stationary baselines and clustered events, yielding accurate void and timing with no hand-tuned assumptions. Results support DL as a practical, data-driven complement to fixed algorithms, particularly in noisy or drift-dominated measuring conditions typical of nuclear thermal–hydraulic loops and safety-relevant test facilities. Full article

Failures at large-scale open-pit mines and tailing dams pose critical risks to human life, environmental systems, and economic sustainability. Although Interferometric Synthetic Aperture Radar (InSAR) has proven effective in detecting long-term surface deformation, a scientifically robust early-warning framework has not yet been established because standardized quantitative thresholds that are capable of distinguishing benign consolidation settlement from instability-driven deformation remain unavailable.InSAR has proven effective for detecting long-term surface deformation. However, a scientific early-warning framework has not yet been proposed or developed due to the absence of standardized quantitative thresholds that distinguish benign consolidation settlement from instability-driven deformation. This research proposes a novel InSAR-based Failure-Risk Index (FRI) that integrates displacement, velocity, and, most importantly, deformation acceleration into a single, normalized metric as an early warning system for mining infrastructure instability. The framework that we propose (i) emphasizes acceleration as a leading indicator of change in mechanical regime, (ii) incorporates a statistically guided separation of long-term consolidation settlement from anomalous deformation based on baseline variability, (iii) applies a statistical standardization and change-point detection system. The methodology is validated through a retrospective analysis of the heap leach failure—that occurred in Çöpler Gold Mine in Erzincan, Türkiye, on 13 February 2024—by using a set of Sentinel-1 time-series images collected between 2014 and 2024. The results prove that while displacement and velocity remained within ranges typically interpreted as stable, deformation acceleration exhibited a statistically significant increase that began around 2020, exceeded baseline variability by approximately two orders of magnitude, which is approximately four years before the collapse, and marked the onset of tertiary creep and progressive instability. The proposed FRI framework successfully captures this transition and provides a transferable, meaningful early-warning framework to support proactive risk management and improve the safety of mining infrastructure. Full article

Low-field nuclear magnetic resonance (NMR) is widely used for nondestructive characterization of petroleum-related porous media, including pore-structure evaluation, fluid identification, relaxation analysis, wettability assessment, and displacement monitoring. Conventional NMR signal models usually rely on the quasi-static approximation, in which the detected magnetic field is assumed to respond instantaneously to Bloch-governed nuclear magnetization. However, classical electrodynamics requires electromagnetic fields generated by time-dependent magnetization sources to depend on the source state at a retarded time. In this study, a retarded magnetic-dipole formulation is developed to evaluate finite-propagation-time effects in low-field NMR signal modeling. The analysis shows that the correction appears mainly as a phase shift governed by the dimensionless parameter $\mathsf{ϵ}={\mathsf{\omega }}_0\mathrm{L}/\mathrm{v}$, where ${\mathsf{\omega }}_0$ is the Larmor angular frequency, $\mathrm{L}$ is the characteristic source–receiver distance, and $\mathrm{v}$ is the effective electromagnetic propagation velocity, with $\mathrm{v}=\mathrm{c}$ in free space. Relaxation-induced amplitude corrections are generally smaller. Numerical examples demonstrate that the quasi-static approximation is well justified when $\mathsf{ϵ}\ll 1$, as typically satisfied in laboratory core NMR. For extended-scale configurations, including unilateral, borehole, underground, and surface NMR, larger propagation paths and medium-dependent electromagnetic properties may increase \epsilon and produce systematic phase deviations. This work provides a theoretical criterion for assessing the validity range of the quasi-static approximation in low-field NMR applications for petroleum-related porous media. Full article

A previous investigation on limonene (LM), perillyl alcohol (POH), and carveol (CV), focused on the structure–activity relationship and hydroxyl group, documented that the presence of the hydroxyl group influences the pharmacodynamic potency of these agents, inhibiting smooth muscle contraction with the order of potency: POH > CV > LM. That investigation also suggested a mechanism of action, which importantly included activity on the voltage-dependent calcium channel. Here, we investigated whether this structure–activity relationship also applies to nerve excitability (an activity greatly dependent on sodium channels) using compound action potential (CAP) recordings from mouse sciatic nerves and in silico simulations. POH, CV, and LM inhibited both the positive amplitudes and conduction velocities of the two CAP components in a concentration-dependent manner, with IC₅₀ values of 0.8, 1.0, and 4.3 mM (1st component) and 0.6, 0.6, and 3.0 mM (2nd component) for amplitude, and 2.4, 2.4, and 7.1 mM (1st component) and 1.0, 2.6, and 4.3 mM (2nd component) for conduction velocity. The order of pharmacodynamic potency, thus, was POH = CV > LM. In silico simulation demonstrated that POH and CV penetrate the Nav 1.6 and accommodate in the channel at the interface between the selectivity filter and the central cavity, a position very favorable to block the channel pore. In contrast, LM exhibited a markedly different docking profile, suggesting that LM binding is less likely to directly obstruct sodium permeation. In conclusion, the three substances investigated inhibited nerve excitability, but those with a hydroxyl group demonstrated greater pharmacodynamic potency. Full article

We examine energetic electron distributions in the region of the diffuse aurora using a two-dimensional bi-Maxwellian model, applied to electron flux data at a single geomagnetic equator (L = 6.5). Electron flux is analyzed as a function of energy and pitch angle and transformed into velocity space to reconstruct the distribution function. An unweighted log-space least-squares fit of the bi-Maxwellian model to the reconstructed distribution yields a reduced residual measure of ${\chi }_v^2=1.000053$, a mean absolute residual of $|\Delta {\log }_{10}f|=0.0469$ dex, an anisotropy factor, $A_T=0.9886\pm 0.0016$, and no statistically significant bulk drift. These results show that, at this location, the bi-Maxwellian model reproduces the observed velocity-space structure with good quantitative accuracy and reveals a quasi-isotropic, near-equilibrium electron population. Full article

This study aimed to test the reliability of measurements obtained using different technologies for sprint time and force–velocity profiles during sprint running. Seventeen elite rugby union players completed three experimental sessions, separated by one week. During each session, players completed two 30 m sprints and measurements were performed simultaneously with a linear encoder, a 10 Hz GPS unit, timing gates and video analysis. Split time (5, 10, 15, 20, 25 and 30 m), maximal velocity (V_MAX, m·s⁻¹) and force–velocity variables (maximal power, P_MAX, W·kg⁻¹; theoretical maximal force, F₀, N·kg⁻¹; theoretical maximal velocity, V₀, m·s⁻¹; maximal ratio of force, RF_MAX, percentage) from the best sprint of each session were computed. Statistical significance was set at p < 0.05 for all analyses. Linear encoder and video analysis showed moderate-to-very-high reliability for sprint time (intraclass correlation coefficient (ICC) = 0.68 to 0.94; standard error of measurement (SEM) = 0.95 to 2.59%), while timing gates showed poor-to-high reliability (ICC = 0.23 to 0.85; SEM = 1.80 to 7.23%). Linear encoder showed very-high reliability for maximal velocity (ICC = 0.94) and force–velocity variables for P_MAX (ICC = 0.90), high reliability for V₀ (ICC = 0.88) as well as RF_MAX (ICC = 0.75), and moderate reliability for F₀ (ICC = 0.66). Linear encoder (ICC = 0.66 to 0.94) and video analysis (ICC = 0.50 to 0.94) were the most reliable methods to measure sprint times while linear encoder, due to a higher sampling frequency, was the most reliable to establish the force–velocity profile. Full article

Hard and brittle material components with complex curved surfaces are widely used in critical foundational parts within aerospace, optoelectronics, and other fields. Their machining quality directly determines the performance and reliability of high-end equipment. However, the inherent properties of hard and brittle materials make them prone to surface/subsurface damage during traditional polishing processes, and maintaining the form accuracy of complex curved surfaces is challenging. Although abrasive waterjet polishing enables non-contact flexible processing, its energy efficiency is low. Additionally, although ultrasonic-assisted polishing can improve material removal, its spatial localization is insufficient, limiting energy utilization efficiency. To address these issues, this paper proposes a novel method of focused, ultrasonic, vibration-assisted abrasive waterjet polishing. The influence of the radiation force and cavitation force of the focused ultrasonic field on abrasive particle motion is analyzed, and analytical equations for abrasive particle velocity are established. Subsequently, single-factor and response surface methodologies are employed to systematically evaluate the influence of process parameters on machining quality and efficiency. The material removal process during FUAP involves both plastic shearing/chip formation and localized brittle fracture. Focused ultrasonic assistance promotes micro-cutting and plastic shearing, while localized crushing pits indicate that brittle fracture remains non-negligible. The focused ultrasound superimposes alternating stress onto the impact action, mitigating microscale crushing pit defects during the brittle removal process of monocrystalline silicon. Furthermore, appropriately increasing ultrasonic power, enlarging abrasive particle size, and raising abrasive concentration all contribute to enhanced material removal from monocrystalline silicon. Adjusting the nozzle height to the effective region of the focused ultrasonic energy field promotes material removal via chip formation while avoiding pit defects caused by excessive fracture. These results suggest that focused ultrasonic energy can be effectively integrated into abrasive waterjet polishing to enhance material removal while suppressing brittle surface defects, thereby offering a promising strategy for the ultra-precision finishing of hard and brittle components with complex curved surfaces. Full article

Land subsidence driven by excessive groundwater extraction in the Choushui River alluvial fan of central Taiwan poses a significant threat to the structural integrity of the Taiwan High-Speed Rail (THSR). This study presents an integrated approach combining multi-temporal Interferometric Synthetic Aperture Radar (MT-InSAR), continuous and campaign Global Navigation Satellite System (GNSS) measurements, and precise leveling surveys to characterize both vertical and horizontal surface displacements along the THSR corridor. Sentinel-1 C-band SAR data from ascending (A69) and descending (D105) tracks were processed using the Small Baseline Subset (SBAS) technique over the period of 2015–2021 and decomposed into east–west (EW) and vertical components via 2.5D decomposition. The InSAR-derived EW velocity field was calibrated using GNSS Ordinary Kriging interpolation, improving R² from 0.147 (RMSE = 4.24 mm/yr) to 0.992 (RMSE = 0.24 mm/yr). The vertical velocity field was corrected using a polynomial trend surface fitted to 922 leveling benchmarks and 38 continuous GNSS stations, reducing the RMSE from 6.03 to 4.85 mm/yr (increasing R² from 0.889 to 0.898) and virtually eliminating the systematic bias (a decrease from +3.47 to −0.47 mm/yr). Maximum subsidence exceeding 60 mm/yr was identified in the Yunlin Tuku area, while three secondary subsidence centers were found in Changhua. The horizontal velocity field revealed a convergent pattern directed toward subsidence centers, with magnitudes of 2–10 mm/yr, confirming that aquifer compaction induces significant lateral deformation. Along the THSR corridor, differential EW velocities across the Xizhou and Tuku subsidence zones highlight potential risks to rail alignment and structural safety, with horizontal strain rates reaching approximately 10⁻⁶/yr. GNSS observations additionally provide the north–south velocity component that InSAR cannot detect, enabling a more complete three-dimensional deformation characterization. Full article

This paper presents a distributed counter-UAV early-warning and response-decision support framework for low-altitude UAV defense. Acoustic–visual edge nodes generate local state packets and exchange compact information-filter parameters through Multi-Target Information Consensus (MTIC), avoiding centralized fusion and reducing payload bandwidth. The MTIC naïvety-handling mechanism is extended to heterogeneous acoustic–visual sensing, improving robustness to partial observations, packet loss, and node disconnection. A Fuzzy–Bayesian threat-assessment layer converts fused distance, velocity, and heading cues into interpretable response recommendations with calibrated confidence. Implemented on ROS 2/Fast DDS with tiered QoS, software-assisted IEEE 1588 synchronization, and Preempt-RT scheduling, the framework achieves within about 5% of centralized accuracy while reducing payload bandwidth by up to about 97% relative to the main centralized baseline. Simulation and hardware-in-the-loop tests on three- and five-node mesh topologies show software-assisted sub-millisecond synchronization (200–500 μs offset), bounded latency, gradual AUC degradation under association mismatch, and end-to-end feasibility under controlled packet loss. Overall, the system provides a resilient, deployment-oriented architecture for distributed C-UAV early warning. Full article

Three-dimensional (3D) S-wave velocity field modeling is a critical task in seismic exploration, but balancing modeling accuracy and geological rationality remains challenging due to sparse observation data and inherent limitations of existing methods. To address this issue, we propose an Ordinary Kriging-Thin Plate Spline-Graph Convolutional Network (OTG) fusion model. It dynamically integrates the global trend capture capability of Ordinary Kriging, the local smooth processing ability of Thin Plate Spline, and the nonlinear feature fitting performance of Graph Convolutional Network (GCN) via an adaptive gating fusion mechanism. A multi-dimensional physical constraint loss function is further designed to ensure the geophysical plausibility of interpolation results. Validated on a dataset from 105 seismic stations in Southwest China using spatial cross-validation and random repeated experiments, the full OTG model achieves a root mean square error (RMSE) of 0.1148 km/s, a mean absolute percentage error (MAPE) of 1.9614%, and a Pearson correlation coefficient (PCC) of 0.9801. Compared with the optimal traditional method (OK) and the state-of-the-art hybrid method (DeepKriging), the proposed model reduces the root mean square error (RMSE) by 42.8% and 8.2%, respectively. This study demonstrates that the OTG model realizes the complementary advantages of traditional geoscientific methods and deep learning, providing a reliable engineering solution for high-precision 3D S-wave velocity structure interpolation in seismic exploration. Full article

Regarding heat conduction in sliding contact pairs, this paper investigates the interfacial heat partition problem with conduction heat flux taken into account to address the issue of the heat partition coefficient falling outside its physically reasonable range. The main contributions of this study are as follows. First, conduction heat flux is explicitly introduced, and the governing equation for the heat partition coefficient incorporating conduction heat flux is derived via Green’s function method. Subsequently, to tackle the nonlinearity caused by the time-varying velocity and heat source of the contact pair, least-squares estimation is adopted to solve for the heat partition coefficient and conduction heat flux. The results indicate that under extreme operating conditions with drastic variations in heat source and velocity, traditional heat partition models yield unphysical results where the heat partition coefficient is less than 0 or greater than 1, whereas the modified model effectively resolves this issue. Furthermore, this paper analyzes the effects of material parameters, motion characteristics, and thermal loads on heat partition. The findings of this work provide a reference for interfacial thermal design and thermal management of various sliding contact pairs. Full article

This paper presents a novel cyclone dust removal device and conducts a preliminary investigation into its internal flow field characteristics. The device is equipped with an impeller with Archimedean spiral characteristics and a whip sheath structure arranged in a circle. Using the computational fluid dynamics (CFD) method, the velocity field, pressure field, vortex structure, and fluid trajectory characteristics are studied under the condition of a fixed rotational speed and different inlet velocities. The simulation results demonstrate that, under a fixed rotational speed of 24.5 rps and TSR = 2.0, the downstream vortex system of the impeller is more coherent and structured, developing into a stable configuration with alternating positive and negative vorticity. When the whip sheath structure is added, a larger radial velocity is generated. This study reveals the unique internal flow field evolution law of the device, which provides a theoretical basis for subsequent particle separation research. Full article