Search Results (12,068)

In this study, hardfacing and a flux-cored/self-shielded powder wire of the FCAW-S-90G13N4 type was employed to produce and investigate the deposits of high-manganese steel. The effects of high-frequency mechanical impact (HFMI) treatment on the microstructure, hardening, and scratch resistance of the deposits were studied to evaluate and predict the impact wear resistance of the hardfacing deposits under controlled impact load conditions. As observed by XRD, SEM, and nanoindentation, the microstructure of deposited metal comprised a soft austenite matrix, dispersed hard carbides, and an ε phase (~26 vol.%). The wear resistance is thus not controlled by carbides alone but arises from the synergistic action of a hard carbide network within a ductile matrix. HFMI resulted in twinning, an increase in dislocation density, a grown volume fraction of ε (>60%) and α′-martensite. The interaction between twins, martensites, and dislocations provides a double/triple increase in microhardness (from HV_0.2 = 2.78 GPa to HV_0.2 = 6–7.69 GPa). After HFMI, scratch tests showed lower restored depths of scratch tracks and a 36–68% deceleration in the wear rate regarding those of the initial deposit. The underlying wear mechanisms were assessed accounting for the SEM observations of the scratch track morphologies and a ‘counterbody penetration vs. shear stresses ratio’ map. The initial plastic deformation-related mechanism (wedge/pile-up formation) changed by HFMI to ploughing. The obtained results allow one to evaluate and predict the impact wear resistance of the hardfacing deposits under controlled impact load conditions. Full article

Climate change is expected to modify precipitation patterns and increase flood hazard in urban areas, potentially affecting critical infrastructures such as wastewater treatment plants (WWTPs), often located in flood-prone zones. This study assesses the impacts of climate-driven changes in extreme rainfall on flood hazard, pedestrian safety, and tangible physical damage at WWTPs in the Metropolitan Area of Barcelona, Spain. Twenty-four future flood scenarios are defined using CMIP6-based downscaled climate projections (SSP126 and SSP585), two time horizons (2041–2070 and 2071–2100), and different climate model percentiles. Climate Change Coefficients derived from updated Intensity–Duration–Frequency curves are applied to hydrodynamic simulations to evaluate flooded and high-hazard areas for plant workers, as well as direct economic damage at the Montcada i Reixac WWTP, used as a case study. Results indicate limited changes under SSP126, while SSP585 leads to systematic increases in hazard extent and damage, particularly for long-term projections (2071–2100) and extreme percentiles (90th). A large dispersion among climate models is also observed, especially for extraordinary flood events. Finally, a site-specific nature-based adaptation measure targeting frequent floods is proposed, demonstrating the potential of integrated assessments to support sustainable adaptation planning and to reduce the Expected Annual Damage in future climate conditions by 93%. Full article

Background: Diabetic foot ulcers (DFUs) are considered a prevalent complication of diabetes mellitus, frequently accompanied with compromised peripheral circulation, slower healing, as well as high risk of infection in addition to risk of amputation. Additional treatments that enhance microvascular perfusion and lessen plantar pressure may accelerate the healing process. This study was carried out to examine the impact of pulsed electromagnetic field (EMF) therapy as well as customized silicone gel insoles in terms of peripheral circulation in addition to vascular indices in patients with DFUs. Methods: A randomized, controlled clinical trial, including sixty-six adults diagnosed with type II diabetes as well as plantar DFUs (Wagner grade I–II) were divided into three groups (n = 22 each): Group A was given low-frequency electromagnetic field therapy (15–50 Hz, 2–5 mT, 30 min, three times per week for 8 weeks), Group B was given a customized silicone gel insoles produced for ulcer offloading, and Group C (control) was given conventional physiotherapy along with wound care. Peripheral microcirculation as well as tissue perfusion were the primary outcomes, and they were measured using Laser Doppler Flowmetry (LDF), Photoplethysmography (PPG), in addition to the Toe–Brachial Index (TBI). The secondary outcome included the Ankle–Brachial Pressure Index (ABPI). A blinded assessor measured the outcomes at the beginning of the study, after the intervention (week 8), and again after the follow-up (week 16). Results: EMF therapy significantly improved LDF (baseline: 45.2 ± 6.5 PU; week 8: 62.5 ± 7.2 PU), PPG (0.42 ± 0.08 mV to 0.68 ± 0.10 mV), TBI (0.64 ± 0.07 to 0.82 ± 0.08), and ABPI (0.88 ± 0.06 to 0.97 ± 0.05) compared with insoles and controls (p < 0.001, partial η² 0.25–0.37). The insole group exhibited moderate enhancements, whereas the control group demonstrated minor changes. Between-group analyses showed substantial differences in favor of EMF therapy across all measured variables (F = 13.5–19.9, p < 0.001). Improvements continued at the 8-week follow-up. Conclusions: Patients with DFUs who receive EMF therapy experience a significant improvement in their peripheral microcirculation, tissue perfusion, as well as vascular indices. This is more effective than just mechanical offloading, and custom insoles offer extra benefits by redistributing pressure. Combining EMF therapy with regular DFU care may speed up healing and lower the risk of problems. Additional research should investigate the efficacy of combined EMF as well as off-loading interventions and their long-term outcomes. Full article

Suicidal behavior among adolescents and young adults represents a growing public health concern due to its high prevalence and its negative impact on psychological well-being. The aim of this study was to examine the associations between emotional regulation, attachment styles, cyberviolence, and suicidal ideation among Chilean university students. A descriptive cross-sectional design was employed with a sample of 1083 participants, using the Suicidal Ideation Frequency Inventory, the Close Relationship Experience Questionnaire (ECR-R), the Spanish Modified Version of the Trait Meta-Mood Scale (TMMS-24) and the Cyber Dating Violence Instrument for Teens (CyDAV-T). Bivariate analyses and binary logistic regression were conducted to identify significant predictors of suicidal ideation. The results revealed a high prevalence of suicidal ideation, particularly among women (19.06%; p < 0.001). Difficulties in emotion regulation were strongly associated with a higher likelihood of suicidal ideation (p < 0.001), whereas adequate (p < 0.001) or excellent (p < 0.01) regulation functioned as a significant protective factor. In addition, a disorganized attachment style was identified as a risk factor (p < 0.05), especially among women (p < 0.01). In conclusion, emotion regulation emerges as a key protective factor against suicidal ideation, underscoring the importance of implementing socioemotional training programs within university settings. Full article

Background/Objectives: Chronic diseases, such as inflammatory bowel disease (IBD), influence patients’ sexuality. Therefore, the aim of this study was to analyze the sexual functioning (SF) of patients with IBD. Methods: We perform a prospective survey study on male and female individuals with IBD using an anonymous questionnaire including 60 inquiries concerning patients’ intimate relationships and SF. The following statistical tests were used: chi-square test of independence, Spearman’s rank correlation coefficient, and Wilcoxon and Mann–Whitney U tests. A significance level of p = 0.05 was assumed as statistically significant. Results: There were 110 respondents with IBD (41% with Crohn’s disease and 57% with ulcerative colitis): 52 women (47%) and 58 men (53%), with a mean age of between 31 and 40 (45%). In 34% of respondents, the assessment of satisfaction with sex after diagnosis decreased, and the difference was statistically significant (p = 0.007). Statistically significant correlations were found between IBD clinical activity and the impact of the disease on sexual desire (p < 0.001), the need for sex after diagnosis (p < 0.001), satisfaction with sex after diagnosis (p = 0.003), the average frequency of intercourse (p = 0.004), the average duration of intercourse after diagnosis (p = 0.001), feeling guilty in the sexual sphere due to the disease (p = 0.006), assessment of one’s attractiveness since diagnosis (p = 0.032), and change in the partner’s erotic perception after diagnosis (p < 0.001). The more aggressive the course of the disease, the more negative the impact on patients’ sexuality. Conclusions: The diagnosis of IBD has a negative impact on patients’ SF—disease flare leads to a decrease in sexual needs, worse experiences and negative body image. Full article

Global agricultural drought is evolving into a compound crisis threatening food security and ecological stability that is characterized by increased frequency, intensity, duration, and spatial extent. Since 2000, the global number of drought events has increased by 29% compared with the previous two decades, and 82% of drought-related losses in developing countries are concentrated in agriculture. The UNCCD (2022) projects that drought may affect up to three quarters of the world’s population by 2050. Climate change and human activities jointly drive this escalation through higher atmospheric evaporative demand, altered precipitation regimes, land use change, groundwater overexploitation, and pollution emissions. Their interaction forms amplifying feedback loops across ecology-agriculture and climate–agriculture systems, resulting in ecosystem degradation, crop yield loss, and rising socioeconomic inequality. Addressing this crisis requires a three-dimensional framework integrating mitigation, adaptation, and collaborative governance. This review synthesizes coupled driving mechanisms, cross-system impacts, and response pathways, and it also highlights priorities in compound-drought attribution, region-specific technology scaling, cross-scale governance, and resilience building in vulnerable regions. Full article

With the scale of new energy access expanding, the proportion of nonlinear loads in the power grid has increased, leading to frequent impact disturbance events. The types of power quality disturbances (PQDs) are becoming increasingly complex, placing greater demands on the accurate identification of disturbance signals. Therefore, this paper proposes a PQD recognition method based on adaptive KS transform and a Multimodal Feature Fusion Network (MFNet). Firstly, using an improved red-billed blue magpie optimization algorithm, the traditional KS transform window function parameters are adaptively optimized to achieve accurate time–frequency localization of PQD. Secondly, considering the differential characteristics of PQDs in different modes, combined with the proposed adaptive KS transform, a parallel MFNet with three branches in the time domain, frequency domain, and time–frequency domain is constructed; to further enhance feature extraction capability and reduce information loss, residual structures are introduced in the network. Multiple comparative experimental results show that the proposed method achieves an average classification accuracy of 99.52% at 20 dB of noise and demonstrates good noise resistance. Full article

The accelerating frequency of emerging infectious diseases (EIDs) in livestock poses a significant threat to global food security, as well as to animal and public health. While wastewater-based surveillance (WBS) has advanced significantly for human health surveillance, its application to livestock production systems remains fragmented and lacks standardization. This review synthesizes current evidence on livestock wastewater-based surveillance (L-WBS) as an early-warning sentinel for emerging viral pathogens, evaluating their dynamics, economic impacts, biosecurity measures, and One Health implications. Existing studies demonstrate that L-WBS effectively detects emerging viral pathogens in agricultural effluent, swine manure, and municipal wastewater systems serving livestock regions, frequently preceding clinical outbreak recognition. We further conceptualized a multifactorial framework linking environmental drivers such as climate and ecological disruption and agricultural intensification to pathogen emergence dynamics. Economic assessments show substantial direct losses (approximately US$ 950 per H5N1-infected dairy cow and US$ 25.9 billion in African swine fever virus (ASFV)-related damages across China) alongside indirect costs from biosecurity implementation, workforce disruption, and supply-chain instability. We recommend prioritizing methodological standardization through unified sampling and extraction protocols, integration of next-generation sequencing for genomic surveillance, and cross-sectoral policy frameworks to operationalize L-WBS as a global early-warning infrastructure for mitigating zoonotic spillover and livestock-dependent community resilience. Full article

School principals face increasing demands that compete for their time and attention, yet contingency—the unexpected situations that interrupt daily work—remains understudied. This study, conducted in Chile’s highly segregated education system, advances beyond frequency-based measures by proposing a Multidimensional Contingency Index (MCI) that integrates both frequency and intensity of contingencies, enabling distinction between “noise contingencies” (frequent, low-impact disruptions) and “crisis contingencies” (less frequent but high-complexity situations demanding significant cognitive and emotional resources). Using data from a nationally representative survey of 381 principals, four key findings emerge. First, family–school relationships represent the heaviest contingency burden, exceeding other domains by up to 320% when considering intensity. Second, individual characteristics (gender, experience, training) do not explain contingency levels: only structural factors matter. Third, public school principals face contingency levels exceeding 300% of those of their private counterparts in critical domains, suggesting that wicked problems are unequally distributed across the school system. Fourth, high contingency strongly correlates with reduced principal well-being, including insufficient preparation time and elevated stress levels. These findings have implications for leadership standards, principal preparation programs, and equity-oriented policies that must address the systematically unequal burden facing schools serving vulnerable populations. Full article

Because of concentrated connection damage, the impact of sequential hazards on CLT shear wall systems is much more severe than that on traditional concrete and steel structures considering ductile component behaviors. The present paper evaluated the dynamic response of CLT wall structures in wind-only and sequential seismic–wind scenarios and compared the structural dynamic responses and damage levels of different CLT wall systems. The structural models were established separately based on an SOM benchmark structure, a SOFIE project three-story CLT shear wall structure, and a PT CLT wall platform structure from the NHERI Tall Wood project. The equivalent fluctuating wind load was calculated with the ASCE 7 average wind speed, the reference ESDU wind profile, calibrated wind pressure distribution, and simulated fluctuation from the NatHaz Online Wind Simulator. The sequential load was applied to the structural models in the order of seismic excitation, resting time, and then dynamic wind load. The dynamic responses of different CLT wall structures were compared among loading scenarios with increasing seismic and wind intensities. The wind-excited peak story displacement and acceleration for both CLT structures were significantly magnified in the sequential seismic–wind scenarios compared with the wind-only scenarios. The simulation results indicated that the sequential seismic–wind scenarios caused significant acceleration in damaged connections for the conventional CLT shear wall structure. The PT CLT wall structure had minor displacement and acceleration, which were linear to the wind loading factors. For the conventional CLT shear wall structure, the magnification of the acceleration was found to have a strong correlation with the natural frequencies of the damaged structure. This study demonstrated that the wind responses of the PT wall structures were in a safe range after the seismic event, and conventional CLT wall structures need to be re-evaluated under sequential scenarios for structural resilience assessment. Full article

The purpose of this research is to examine the impact of industrial noise levels ranging from 74 to 76 dB—which fall below the legal limit of 80 dB—on complex physiological and psychological stress responses of workers. The study employs a multimodal approach, combining objective acoustic measurements according to the EN ISO 9612:2009 standard with the monitoring of physiological parameters, specifically galvanic skin response (GSR), blood pressure, and heart rate, complemented by subjective assessments through questionnaires. Key findings revealed that the C-weighted noise level L_CEX (r = 0.67) demonstrates a stronger correlation with stress response and heart rate (r = 0.66) than the standard A-weighted filter (L_AEX). Although noise explains only approximately 4% of heart rate variability (R² ≈ 0.04), providing indirect support for the multifactorial nature of stress, subjectively, 71% of workers expressed a need for noise reduction due to accompanying symptoms such as headaches and tinnitus. The highest level of cardiovascular load was consistently recorded at workstation SZ7. The results suggest that industrial noise may represent a contributing factor to psychosocial risk even at levels below regulatory limits. The results provide indirect support for the hypothesis that low-frequency noise (LFN) components play a role in psychosocial stress, suggesting the need for further investigation using detailed spectral analysis in the prevention of industrial psychosocial diseases. Full article

Due to the complex mesostructure of calcareous sand, accurately predicting the mechanical response of Asphalt-Bonded Calcareous Sand (ABCS) is extremely challenging. This study pioneers the development of a mesoscale model for ABCS that explicitly incorporates the Interfacial Transition Zone (ITZ) via a random particle algorithm. To overcome the efficiency bottlenecks of traditional time-domain integration, this study establishes a mesoscale framework coupling a random polygonal aggregate algorithm with direct Steady-State Dynamics (SSD) analysis. A major advantage of this framework is its capacity for large-scale parametric sensitivity analysis; herein, 920 independent mesoscale models were generated and rapidly solved across the broadband frequency domain. The framework was rigorously validated, demonstrating high predictive accuracy for both the baseline calibration and an independent 12% asphalt content mixture (baseline R² = 0.99, MAPE = 6.94%; independent validation R² = 0.96, MAPE = 9.73%). Notably, the SSD approach completes calculations (10⁻³ to 10³ Hz) for 10 massive 300 mm RVEs in just 6.5 min. Leveraging this high-throughput capability, the extensive parametric analysis reveals that variations in maximum aggregate size negligibly impact the dynamic modulus under a constant volume fraction. Conversely, an optimal Interfacial Transition Zone (ITZ) thickness of ~75 µm was identified, representing a physical equilibrium between interfacial reinforcement and bulk binder cohesion. Furthermore, an analytical RVE size criterion of 1.7–5.3 times the maximum aggregate size is proposed to satisfy a 5% engineering error tolerance, providing a highly efficient numerical tool for the virtual mix design of reef pavements. Full article

Carbon fiber-reinforced polymer (CFRP) laminates are widely used in aircraft skins due to their advantages of high strength and lightweight properties. However, their laminate structure and energy-absorbing characteristics result in low-energy impact damage, such as delamination, that is often invisible but can lead to catastrophic failure. Consequently, early detection of delamination in CFRP laminates is necessary. Nonlinear ultrasonic guided waves exhibit high sensitivity to delamination, and second harmonics are widely employed. Compared to second harmonics, one-way mixing of ultrasonic guided waves can excite and receive signals simultaneously at the same location, thereby precisely localizing delamination. This capability has the potential for inspecting buried structures. However, existing literature has not yet fully addressed the generation mechanism of one-way mixing in CFRP laminates nor its interaction with delamination. Based on finite element simulation, this study investigates one-way mixing of A₀ modes and S₀ modes in CFRP laminates. Utilizing pulse-inversion techniques and two-dimensional fast Fourier transforms, the modes and propagation directions of difference-frequency components and sum-frequency components are determined. Furthermore, by utilizing the normalized acoustic nonlinearity parameter χ’ and adjusting the position of the mixing zone through different time delays, delamination in the CFRP laminate is successfully localized. Full article

The problem of power system oscillation stability has become more and more prominent in the context of a high proportion of new energy sources and the gradual increase in power electronic devices. Broadband oscillations pose new challenges to the security and stability of power systems. In recent years, the frequency of power system oscillations around the world, especially those triggered by wind, solar, and power electronic devices such as flexible direct current (DC) transmission, has shown that the geographic and system scale of their impacts continue to expand. Failure to properly control these broadband oscillations can lead to serious consequences such as equipment damage, off-grid renewable energy generation systems, and large-scale blackouts. Two strategies, data-driven and model-driven, have been used for monitoring and controlling broadband oscillations, but each has its limitations. The data-driven approach relies on data quality, while the model-driven approach requires high accuracy of the system model. For this reason, hybrid data-model-driven strategies have emerged. They combine the advantages of both to improve the accuracy and robustness of system analysis. In this paper, we will discuss the principle of hybrid data-model driving and its application to broadband oscillations, classify different frequency oscillations, and introduce risk warning methods, and finally summarize future research challenges such as quantitative analysis, propagation mechanisms and suppression measures of broadband oscillations. Full article

Managing supply chain risks is a core pillar of operational and supply chain resilience building in the global industrial chain system, which is essential for the high-quality and sustainable development of manufacturing firms. Against the backdrop of escalating global economic uncertainties and interconnected supply chain vulnerabilities, mitigating the adverse impact of supply chain risks on firms’ overseas market expansion has become a critical research and practical issue in the field of operational and supply chain risk management. Based on the textual analysis of annual reports of listed firms, this study constructs a systematic supply chain risk measurement indicator system through standardized text preprocessing, multi-dimensional feature keyword lexicon construction, context co-occurrence frequency calculation and so on. We further validate the effectiveness of the indicator system by comparing its trend with the global economic uncertainty index, confirming that it can capture firm-specific supply chain risk information effectively. Employing text analysis, this study constructs a systematic supply chain risk measurement indicator system for A-share manufacturing firms and empirically verifies that elevated supply chain risks significantly constrain their overseas market expansion. Three interrelated operational mechanisms, namely surging operating costs, tightened financing constraints, and slumping R&D investments, drive this inhibitory effect. Notably, firms can effectively offset this negative effect by broadening overseas operational scope and intensifying overseas digital and technological innovation. Heterogeneity analyses further reveal that the inhibitory effect is more pronounced for five types of firms: those with lower overseas revenue, located in less market-oriented regions, operating in upstream value chain sectors, with lower current liabilities, and with a lower degree of digital transformation. Full article