Search Results (2,369)

Coastal and offshore steel infrastructures such as transmission towers and wind turbine towers are prone to coating degradation after long-term exposure to salt fog, high humidity, and ultraviolet radiation. The subsequent uniform corrosion significantly reduces the cross-sectional load-carrying capacity and threatens structural safety. This paper presents a numerical parametric analysis on the compression behavior of circular steel tube (CST) members subjected to uniform corrosion induced by coating failure, based on 18 accelerated corrosion tests. The effectiveness of the wall thickness reduction method for simulating uniform corrosion after coating degradation is verified, and the influence of key parameters on load-carrying capacity degradation is systematically investigated. A simplified formula for elastic local buckling of corroded CSTs is derived, and a direct strength method (DSM) calculation framework considering both global buckling and local–global interactive buckling is established. The results show that the uniform corrosion ratio is the dominant factor affecting load-carrying capacity degradation, while sectional dimension, slenderness ratio, and eccentricity have negligible influence. The proposed DSM method achieves a prediction error within 5% compared with test and numerical results. It is primarily applicable to uniformly corroded steel tubes represented by equivalent wall thickness loss, and its applicability to scenarios with localized corrosion, pitting corrosion, weld-zone corrosion, or non-uniform wall thickness reduction requires further validation. This method provides a rapid and accurate tool for residual load-carrying capacity assessment and life cycle management of coastal steel infrastructures after coating failure. Full article

Low-cost air temperature and relative humidity sensors are increasingly deployed in dense urban monitoring networks for the characterization of urban heat islands and heat exposure. However, measurement accuracy strongly depends on the performance of the radiation shield protecting the sensor from solar heating. This study evaluates five low-cost radiation shield designs, including naturally ventilated, forced-ventilated, spherical, and chimney-type configurations, under tropical outdoor conditions on Reunion Island. Five calibrated SHT31 sensors were deployed simultaneously alongside a reference meteorological station over a five-week measurement campaign. Shield performance was assessed using standard metrological indicators, daytime–nighttime analyses, error distributions, and two-dimensional irradiance–wind diagnostics. Temperature RMSE values ranged from 0.68 to 1.18 °C, while relative humidity RMSE ranged from 2.65 to 7.39%. The forced-ventilated shield provided the best overall temperature performance, whereas the chimney-type design exhibited the largest errors. Combined irradiance–wind analyses showed that measurement errors were primarily governed by the balance between radiative forcing and convective cooling, with maximum temperature biases exceeding 2.5 °C under high-irradiance and low-wind-speed conditions. Based on these findings, several correction approaches were evaluated. A physically interpretable semi-empirical model reduced RMSE by 50%, while a Random Forest model achieved reductions of up to 66%. These results suggest that low-cost meteorological measurements can be substantially improved through appropriate shield design and meteorologically informed calibration procedures, particularly under tropical conditions characterized by strong solar radiation and limited precipitation. Full article

Background/Objectives: The safety of hypofractionated postmastectomy radiotherapy (HF-PMRT) in patients undergoing implant-based breast reconstruction remains uncertain because of concerns regarding radiation-related reconstructive complications. We conducted a systematic review and meta-analysis to compare reconstruction-related complications following HF-PMRT versus conventionally fractionated (CF) PMRT. Methods: PubMed, Cochrane Library, and EMBASE databases were searched through August 2025 following PRISMA guidelines. Studies comparing HF-PMRT with CF-PMRT in patients undergoing implant-based breast reconstruction were included. Outcomes were capsular contracture, implant or tissue expander removal, infection, and wound dehiscence. Risk of bias was assessed using RoB 2 and ROBINS-I tools. Odds ratios (ORs) with 95% confidence intervals (CIs) were pooled using the Mantel–Haenszel method. Subgroup analyses were performed by reconstruction stage (tissue expander vs. permanent implant). Results: Seven studies (n = 2200 patients; 1153 HF, 1047 CF) were analyzed, comprising two randomized controlled trials and five retrospective cohort studies. HF-PMRT was associated with a significantly lower risk of capsular contracture (OR 0.65, 95% CI 0.47–0.92) and wound dehiscence (OR 0.39, 95% CI 0.16–0.94) than CF-PMRT. Implant or tissue expander removal (OR 0.90, 95% CI 0.67–1.22) or infection (OR 0.98, 95% CI 0.67–1.44) did not differ. In subgroup analyses, reduction in capsular contracture was most evident when PMRT was delivered during the tissue expansion phase. Conclusions: These findings suggest that moderate hypofractionation is a reasonable fractionation option for implant-based breast reconstruction, with no evidence of increased reconstructive complications, although the certainty of evidence was limited, and prospective validation is warranted. Full article

Quantifying dust aerosol radiative impacts on crop growth in arid regions is challenging due to sparse ground observation networks for photosynthetically active radiation (PAR). Conventional meteorological stations only provide regional-averaged solar radiation and fail to capture fine spatial heterogeneity and instantaneous attenuation caused by dust storms. To address this gap, this study developed a coupled framework integrating WRF-Chem, LibRadtran, multi-source remote sensing, and interpretable machine learning. We combined field sampling data, remote sensing products, and atmospheric simulations to explore how dust aerosol direct radiative forcing alters cotton gross primary productivity (GPP) and yield across the Weigan River Basin, Xinjiang, China. Results revealed significant PAR reduction induced by dust in 87% of cotton fields (p < 0.05). Dust presented a dual effect: it reduced photosynthetic productivity via radiation attenuation, while alleviating heat stress above 35 °C. SHAP analysis demonstrated that cotton GPP and yield declined nonlinearly when daily PAR loss exceeded 20 W·m⁻², with the flowering-to-boll stage (July–August) identified as the most sensitive phenological window. This study verifies the necessity of combining atmospheric models and remote sensing for fine-scale assessment of dust radiative effects in data-scarce regions. The identified threshold provides practical references for targeted field management in arid cotton areas. Full article

Drainage solution reuse in soilless strawberry production can reduce nutrient-rich discharge, but adoption requires microbial control, hydraulic reliability, and manageable energy demand. This field study evaluated a photovoltaic (PV) assisted ultraviolet-C (UV-C) treatment loop for substrate derived drainage solution in a 132 m² three-tier natural light greenhouse producing ‘Solhyang’ strawberry in Sokcho-si, Republic of Korea. The system used an 11.25 kWp vertical windbreak-type PV facility and a 650 W treatment loop comprising a 250 W low-pressure mercury UV-C reactor, a 350 W pump, and a 50 W controller. The loop operated for 2.5 h day⁻¹, processed 3.25 m³ day⁻¹ as cumulative reactor throughput, and consumed 1.625 kWh day⁻¹, equal to 4.22% of the measured daily PV alternating current (AC) output (38.5 kWh day⁻¹). The drainage solution had low ultraviolet transmittance at 254 nm (UVT₂₅₄; 25–50%) and moderate turbidity (5–30 NTU), conditions that can attenuate UV radiation and shield microorganisms. Across six post fruit set sampling events, the mean log₁₀ reductions were 1.15 ± 0.09 for culturable molds/fungal propagules and 1.64 ± 0.09 for culturable aerobic bacteria; paired tests on log₁₀ transformed counts were significant (p < 0.001). Total coliform bacteria were not detected after treatment, corresponding to a detection limit-based lower-bound reduction of ≥2.69 ± 0.17 log₁₀. Apparent fluence values were treated as engineering estimates rather than validated delivered dose. The results support UV-C sanitation as a preliminary enabling step for drainage solution reuse, while biodosimetry, untreated circulation controls, multi-stage seasonal sampling, full-season recirculation, and crop response validation remain necessary. Full article

The rapid evolution of fifth-generation (5G) and emerging sixth-generation (6G) wireless communication systems has considerably intensified the need for high data rates, ultra-low latency, massive connectivity, and intelligent network integration. To satisfy these requirements, millimeter-wave (mmWave) bands offer large available bandwidths; however, their severe propagation losses and integration constraints necessitate advanced antenna solutions. In this context, compact multi-port Multiple-Input–Multiple-Output (MIMO) antennas are a key solution for high-capacity and reliable mmWave communications. This review presents a comprehensive overview of recent antenna system technologies for 5G/6G applications, focusing on small mmWave MIMO antenna designs, performance improvement methods, advanced materials, and smart integration methods. Several antenna structures, such as microstrip patch, dielectric resonator, slot-based, and metamaterial-inspired designs, are critically discussed and compared. In addition, this review analyzes key design challenges involving miniaturization, mutual coupling reduction, bandwidth enhancement, gain improvement, radiation efficiency, and integration complexity, along with their impact on key performance metrics. The importance of advanced materials, artificial-intelligence-assisted optimization, hybrid antenna architectures, and smart integration strategies in future 5G/6G systems is also emphasized. Finally, we identified current challenges, emerging trends, and future research directions to provide useful design guidelines for researchers and engineers developing next-generation high-performance antenna systems for intelligent wireless communications. Full article

Floating tidal platforms provide a flexible solution for offshore tidal–stream energy exploitation, but their wave-induced motions may affect platform stability, turbine operation and power performance. Integrating wave energy converters (WECs) with a floating tidal platform provides a potential approach to absorb wave energy and modify platform motions. However, the dynamic role of a WEC array attached to a floating tidal platform remains insufficiently understood, especially with respect to array layouts, power take-off (PTO)-induced coupling and absorbed power. This study investigates the effects of WEC array layout on the motion response and absorbed power of a catamaran-type floating tidal platform under irregular wave excitation. Three representative WEC array layouts, namely longitudinal, transverse and hybrid arrangements, were compared with a baseline platform without WECs. A coupled numerical model was established by combining frequency-domain radiation-diffraction analysis and time-domain simulations of mooring system and PTO dynamics based on ANSYS AQWA 2023R2. The hydrodynamic model was verified through code-to-code comparisons with OrcaWave 11.6, and the PTO power model was checked against published numerical results. The results show that the WEC array layout has a significant influence on both platform response and power absorption. Among the investigated layouts, the transverse array provides the most effective overall motion suppression, with average reductions of 36.83% in heave responses and 52.62% in pitch responses compared with the baseline platform. Frequency-domain results indicate that pure multi-body hydrodynamic interaction has a limited influence on the platform response amplitude operators (RAOs) and wave-excited forces, whereas time-domain results reveal much stronger layout-dependent responses once PTO coupling was included. The WECs’ absorbed power was strongly affected by the geometric relationship between the PTO rotation plane and the dominant platform motion plane. When these two planes were aligned in coplanarity, platform motion enhances the relative PTO rotation and increases output power. These findings indicate that, for floating tidal platforms with relatively small displacement, WEC arrays should be treated as distributed dynamic subsystems rather than only as energy-harvesting add-ons. The results can provide useful guidance for the layout design and coupled dynamic assessment of floating hybrid tidal–wave energy converters (HTWEC). Full article

Shading nets are increasingly used in warm-climate vineyards to mitigate excessive cluster exposure. However, relatively few studies have evaluated their effects on fruit-zone microclimate and berry composition. This single-season field study evaluated the effects of conventional and photoselective shading nets in Cabernet Sauvignon on cluster-zone radiation, thermal conditions, bunch sunburn and powdery mildew percentage, berry maturity, and free amino acid content. Shading treatments significantly modified incident photosynthetically active radiation in the bunch zone, while air-temperature-derived thermal indices were not significantly affected. The conventional black Raschel net produced the greatest reduction in incident radiation, but this reduction was not associated with a decrease in sunburn or powdery mildew severity in bunches. The gray–pearl photoselective net maintained intermediate radiation levels and showed a lower severity of sunburn and powdery mildew, together with higher must pH and lower berry arginine content. The black–white photoselective net reduced berry soluble solids, while the conventional Raschel net increased berry histidine content, indicating that berry maturity and amino acid responses were treatment-dependent. These results provided preliminary field evidence on the effects of shading nets on Cabernet Sauvignon bunch sanitary and berry composition. Therefore, further multi-season and multi-site studies are needed before broader recommendations on shading-net use in warm-climate vineyards. Full article

This case study numerically investigates PCM integration into attic constructions to mitigate summer overheating and improve indoor thermal stability. Attic spaces are vulnerable to overheating due to lightweight construction and intense solar radiation on the roof envelope. Simulations were performed in DesignBuilder using the EnergyPlus engine on a model validated against in situ measurements. Three variants of an organic paraffin PCM composite with aluminum encapsulation were defined: ceiling, sloping roof, and floor under the roof window, at thicknesses of 20 and 40 mm with a melting temperature of 28 °C (Rubitherm RT28HC) based on measured temperatures. Results demonstrated that the integration position is the dominant factor governing effectiveness. Floor integration yielded the most favorable results due to direct solar radiation exposure, reducing time exceeding 30 °C by 63% at 20 mm thickness. Increasing thickness to 40 mm brought substantial improvement for the floor variant (up to 4.85 °C reduction in maximum operative temperature), while ceiling and roof variants were marginal. These findings confirm that targeted floor-level PCM placement effectively reduces peak summer overheating, though mild overheating duration above 26 °C increases as thermal exposure is redistributed from extreme peaks to a milder band. Full article

Small unmanned aerial vehicles (UAVs) are widely used in civil and military fields, and their noise problem has always been the industry’s focus. Compared with a traditional propeller fan, a ducted fan offers higher aerodynamic efficiency, lower aerodynamic noise, and greater safety. It has become the key power component of small UAVs. However, due to the rigid restriction on tip clearance, the traditional integral ducted fan is prone to generating a tip leakage vortex, which produces high-intensity aerodynamic noise and significantly reduces propulsion efficiency. To address the above key problem restricting the quiet flight of small UAVs, this paper designs a segmented ducted fan (SDF). It preliminarily explores the influence of the segmented clearance on the fan’s flow field structure and acoustic radiation characteristics. Specifically, the k-ω SST (shear stress transport) turbulence model and the broadband noise source model were used to establish a computational fluid dynamics model, and the effects of fan speed (20,000–40,000 rpm) and duct spacing (0–20 mm) on its aeroacoustic characteristics were systematically studied. The results showed that the SDF’s acoustic power level maximum (APL_max) was significantly higher than that of the traditional integral structure, especially at high speed. At 40,000 rpm, increasing the duct spacing to 20 mm resulted in a sudden increase in APL_max to 194.5 dB, 61.3 dB higher than that of the integral type. Its essence was derived from the three-stage chain amplification mechanism: (1) strong tip leakage vortex induced by geometric clearance; (2) broadband noise caused by vortex impacting the duct wall; (3) resonant coupling of leakage vortex harmonic frequency and duct cavity standing wave. Based on this, a collaborative noise reduction path was proposed: compressing the spacing to ≤10 mm to suppress the intensity of leakage vortex, designing the periodicity of failure vortex combined with the serrated blade tip/inner wall rubber strip, and blocking the acoustic cavity resonance with non-uniform wall stiffness or 8–10 kHz Helmholtz resonator, providing a solution for the low-noise design of UAV propulsion system. Unfortunately, our study cannot currently resolve transient characteristics; only time-averaged velocity/pressure flow-field contours and total acoustic power distribution are obtained for qualitative analysis of macroscopic noise variation laws and flow-sound correlation. Full article

Mediterranean grasslands are highly sensitive to climate variability because their productivity is strongly constrained by water availability. Understanding how future climate change may affect forage production across hydroclimatic gradients is essential for the adaptation of extensive grazing systems. This study evaluated the response of Mediterranean grassland productivity to future climate scenarios along a climatic gradient in central Spain using the ecohydrological model SIMPAST driven by an ensemble mean of six CMIP6 global climate models under four Shared Socioeconomic Pathways (SSPs). Three representative grassland systems located in mountain, foothill, and semi-arid flatland environments were characterized according to vegetation composition, soil properties, and historical biomass production. The model was calibrated using productivity data from 2016 to 2023 and independently validated with biomass observations from 2024 to 2025. Calibration focused on radiation use efficiency and water use efficiency parameters, achieving high agreement between simulated and observed biomass (R² = 0.90) with calibration absolute errors below 20 kg DM ha⁻¹ across the three study sites. Independent validation using biomass observations from 2024 to 2025 resulted in RMSE values ranging from 506 to 771 kg DM ha⁻¹. Simulations revealed clear spatial differences in future productivity responses. Mountain grasslands exhibited stable productivity throughout most of the century, with projected biomass reductions of approximately 4% and increases in interannual variability of 14% under SSP5–8.5 relative to the historical period. In contrast, foothill grasslands showed moderate productivity declines (25%) and higher variability (37%), while semi-arid flatland systems revealed the strongest reductions in biomass production (33%) together with the largest increase in interannual variability (72%). These results indicate that arid environments are considerably more vulnerable to future climatic stress due to stronger water limitations. Simulations also suggested increasingly variable and less predictable forage availability under future climate conditions, particularly under higher-emission scenarios. Overall, the findings highlight the central role of water availability in regulating Mediterranean grassland productivity and demonstrate the usefulness of ecohydrological models for supporting adaptive grazing management and climate change adaptation in Mediterranean livestock systems. Full article

The decentralized deployment of photovoltaic (PV) systems in urbanized polluted mountainous basins faces unique challenges due to complex topography, persistent cloud cover and winter smog conditions. This study quantifies the atmospheric impact of localized winter haze/smog and Saharan dust intrusions on PV performance in the intermontane basin of Ioannina, NW Greece. By integrating a Digital Twin (DT) methodology with real energy production data, two PV plants were evaluated, a ground-based and a rooftop installation, to isolate the energy deficits caused by aerosol attenuation. The DT model demonstrated high accuracy (R² = 0.847) against actual power generation data for Koutselio and R² = 0.865 for Mpafra PV plants, while MBE was near zero for both sites (−0.008 kWh and −0.139 kWh, respectively). Error analysis revealed that the highest modeling discrepancies occurred during scattered clouds and intense winter haze conditions, primarily due to low spatial resolution of CAMS that fails to adequately capture localized biomass burning (BB) events. Despite the reduction in direct sunlight during extreme winter BB events, results indicate that the overall energy loss is mild. This operational stability is primarily due to the ability of c-Si modules to effectively utilize near-infrared radiation, which penetrates the low-level haze layer, alongside the thermal efficiency gains provided by low early-morning temperatures. Crucially, the installation geometry may influence system vulnerability. Direct comparisons revealed a minor power deviation of −4.8% for the ground-based Koutselio plant, while for the Mpafra site, there was a +3.2% production surplus likely linked to the high sky-view factor the rooftop installation has, which manages to capture isotropic diffuse irradiance. However, the low CAMS resolution may misclassify the haze events within the basin, further contributing to these discrepancies. On the contrary, Saharan dust intrusions caused broadband light attenuation, dropping the power production significantly on both installations. Ultimately, this research provides critical insights into the resilience of solar systems under strong air pollution events within polluted valleys in Southern Balkans, highlighting the connection between panel design and atmospheric attenuation. Full article

The growing demand for polymer recycling requires effective approaches to improve the performance of recycled materials and expand their practical applications. In this study, electron-beam irradiation was investigated as a method for modifying recycled polyethylene obtained from façade-fastening elements. Virgin PE-80 polyethylene was used as a reference material for comparison. Irradiation was carried out using an ILU-10 electron accelerator (5 MeV) at doses of 95–125 kGy. Structural, morphological, elemental, thermal, crosslinking, and mechanical characteristics were evaluated using FTIR spectroscopy, SEM/EDS analysis, differential scanning calorimetry (DSC), gel fraction determination, and tensile testing according to ISO 527. The results showed that irradiation promotes the formation of a crosslinked network structure in both materials, as confirmed by the increase in gel fraction with increasing dose. For recycled polyethylene, gel fraction values increased from 46.7 to 56.2%, indicating effective radiation-induced crosslinking despite the structural heterogeneity of the material. FTIR analysis revealed the formation of oxygen-containing functional groups associated with radiation-induced oxidation, which was more pronounced in recycled polyethylene due to the presence of pre-existing defects and degradation products. SEM observations revealed increased surface roughness and localized fibrillar features after irradiation, while DSC analysis indicated a decrease in the crystallinity of recycled polyethylene associated with radiation-induced crosslinking and restricted molecular chain rearrangement. Mechanical testing showed an increase in tensile strength and elastic modulus accompanied by a reduction in elongation at break. Among the investigated irradiation doses, 110 kGy provided the most favorable balance between crosslinking efficiency and preservation of structural integrity. These findings demonstrate that electron-beam irradiation is an effective strategy for upgrading recycled polyethylene by improving its mechanical performance while maintaining structural integrity, thereby expanding its potential for reuse in circular economy applications. Full article

Background: The increasing utilization of diagnostic imaging has raised concerns regarding imaging overuse, unnecessary radiation exposure, and downstream diagnostic cascades. Because primary care physicians serve as the first point of contact for most patients, diagnostic decisions made in primary care may substantially influence healthcare resource utilization at the system level. This study aimed to develop and evaluate a conceptual diagnostic stewardship framework for primary care using a simulation-based modeling approach. Methods: A synthetic dataset consisting of 100 common primary care conditions was developed across ten clinical domains. Model parameters, imaging utilization probabilities, and diagnostic pathway assumptions were derived from literature-informed estimates and multidisciplinary expert judgment. Each condition was assigned diagnostic attributes including World Health Organization age group classification, commonly requested laboratory tests, preferred imaging modality, and imaging necessity classification (Class A: imaging usually unnecessary; Class B: conditional imaging; Class C: imaging usually required). Using this dataset, a simulation model representing one million hypothetical primary care visits was constructed. Imaging utilization, modality distribution, radiation burden index, incidental diagnostic cascades, and a relative diagnostic resource utilization index were estimated under a baseline diagnostic scenario and a framework-guided diagnostic stewardship scenario. Results: In the baseline scenario, the model generated 412,000 imaging examinations across one million simulated visits (41.2% imaging rate). Within the simulation model, application of the framework was associated with an estimated reduction in imaging examinations to 258,000, corresponding to a 37% reduction in imaging utilization. The estimated population-level radiation burden index decreased from 285,000 to 179,000 units, representing a 37% reduction in radiation exposure. The number of incidental diagnostic cascades decreased from 48,200 to 29,700 events, while the relative diagnostic resource utilization index decreased from 2,480,000 to 1,690,000 units. Sensitivity analyses confirmed the robustness of these findings across alternative model assumptions. Conclusions: Within the assumptions of this simulation model, the proposed diagnostic stewardship framework generated modeled reductions in imaging utilization, radiation burden, and downstream diagnostic consequences. These findings illustrate the potential impact of structured diagnostic stewardship strategies and provide a hypothesis-generating basis for future validation using real-world clinical data. Full article

Accurate large-scale crop mapping is fundamental to agricultural management. However, in Liaoning Province, undulating terrain and fragmented fields make fine crop classification challenging. In particular, corn and soybean have overlapping phenologies, which can lead to spectral and structural confusion in conventional optical–SAR feature spaces and limit mapping accuracy. This study proposes a fine crop mapping framework integrating optical phenotypic, microwave structural, and meteorological time-series features. To overcome the curse of dimensionality caused by high-dimensional heterogeneous data, an adaptive feature truncation mechanism based on the transition pattern of the marginal-gain curve was designed. Additionally, a pyramid multi-scale sliding window algorithm was constructed to optimize meteorological features, achieving dimensionality reduction and precise identification of phenologically sensitive windows. The results indicate that: (1) The multi-scale feature selection strategy effectively eliminates redundant variables and maximizes the inter-class discriminability of core features, significantly improving computational efficiency and classification performance. (2) High-frequency meteorological features provide key physiological constraints. Specifically, mid-May shortwave radiation, early October precipitation, and early August growing degree days constitute the core environmental–physiological features for distinguishing confused crops, helping to mitigate the spectral confusion of dryland crops. (3) Driven by the multi-source features, the Support Vector Machine (SVM) exhibits the optimal generalization robustness for processing high-dimensional structured data, yielding an overall classification accuracy of 91.80% and a Kappa coefficient of 0.8905. This framework provides a reliable methodological reference for high-precision crop monitoring in large-scale complex planting areas. Full article