Search Results (1,130)

This review systematically investigates the developmental trajectory of Gas Metal Arc Welding (GMAW), beginning with its fundamental forms: Metal Inert Gas (MIG) and Metal Active Gas (MAG) welding. In the analysis of high-efficiency GMAW processes, a comparative evaluation was conducted across five major categories of efficiency enhancement strategies: single-wire high-efficiency welding, dual-wire high-efficiency welding, hybrid high-efficiency welding, Narrow-Gap Gas Metal Arc Welding, and Deep Penetration Gas Metal Arc Welding, accompanied by a detailed elaboration on auxiliary high-efficiency measures. This article systematically reviews the arc behavior, droplet transfer behavior, and the influence of residual stress distribution on weld formation and mechanical properties in high-efficiency gas-shielded welding processes utilizing various advanced welding methods. The mechanisms behind typical defects, such as pores, undercutting, and cracks, are elucidated, and corresponding mitigation strategies are summarized. The existing high-efficiency melting electrode gas-shielded welding technology has been widely applied in fields such as automobile manufacturing, shipbuilding, and pipeline welding, resulting in significant economic benefits. In response to the evolving demands of intelligent manufacturing, future research should prioritize the development of real-time monitoring, adaptive control systems, and cost-effective automation solutions for high-efficiency GMAW processes. By constructing high-precision process models, the advancement of efficient welding technology can progress towards greater intelligence and reliability, thereby providing more competitive solutions for industrial manufacturing. Full article

Voice phishing (vishing) causes financial and psychological harm, yet deployed detectors that scan transcripts for scam vocabulary are more fragile than their benchmark scores suggest: their near-perfect accuracy on standard Korean corpora is memorization, collapsing under scammer paraphrase or language-model rewriting. We construct KorMMP, a benchmark keeping real regulator-sourced scam audio and real benign speech but decorrelating transcript from label, and MiLTL, an on-device detector built on affective and neutrosophic channels, including a cross-modal contradiction signal (XM) formulated to weigh lexical warmth against vocal coldness. In the reported evaluation, XM’s measured contribution is confidence banding and escalation routing rather than ranking accuracy. A scoring rule with zero gradient-learned parameters at inference screens every segment, referring ambiguous calls to a small on-device language model; raw audio stays on the device. We measure both stages on a commodity CPU container and smartphone; these budgets cover the detector only and exclude speech recognition, which we expect to dominate a live end-to-end budget. With no training on the hard benchmark, MiLTL achieves an AUROC of 0.965 (recording-level cluster bootstrap 95% CI 0.943–0.984), while every evaluated comparator stays below 0.69: text-only, audio-only, fusion, 7B multimodal. MiLTL scores lower on the saturated corpus, as expected for a detector designed not to rely primarily on lexical shortcuts. KorMMP is a controlled stress test of lexical decorrelation, not a measure of in-the-wild detection; its harmful and benign audio come from different corpora, so the source and label are structurally confounded, and the residual source effects cannot be fully excluded. XM is author-defined, constructed rather than naturally occurring in the synthetic stratum and not yet validated against human perception; this is the principal open limitation of the work. Within that scope, the work provides a reproducible basis for on-device vishing defense and a benchmark for detector robustness under vocabulary shift. Full article

Flexible membrane structures, such as solar sails and membrane reflectors, rely on accurate characterization of in-plane prestress for structural reliability and functional performance. This study proposes a Boundary Virtual Load Method (BVLM) for the semi-analytical prediction of prestress fields in corner-tensioned rectangular membranes. An initial corner-dominated radial stress field is constructed by superposing the stress solutions generated by four corner loads. Residual normal stresses along the nominally free edges are then evaluated, and boundary virtual loads of equal magnitude and opposite direction are introduced to approximate the zero-normal-traction condition. Polynomial representations of these virtual-load distributions are incorporated into the Airy stress-function framework, yielding a boundary-corrected closed-form prestress solution. Comparisons with finite element results for three membrane configurations show that BVLM accurately captures the principal spatial characteristics and aspect-ratio-dependent evolution of the prestress field while requiring substantially lower computational cost for the cases examined. The predicted prestress fields are further incorporated into a free-vibration model that accounts for the added mass of the surrounding air. The resulting natural frequencies generally reproduce the experimentally measured modal-frequency trends, although mode-dependent discrepancies are observed for several modes. The 12 frequency comparisons yield a mean absolute relative error of $8.46\%$, indicating reasonable overall agreement for the approximate analytical formulation. These comparisons provide an indirect dynamic consistency assessment rather than a direct validation of the spatial prestress field. BVLM therefore offers an efficient framework for prestress analysis, preliminary vibration prediction, and parametric design of corner-tensioned membranes. Full article

The mechanical behavior of lunar regolith is crucial for lunar exploration projects, particularly drilling and sampling equipment. However, the extremely limited quantity of returned lunar regolith is insufficient for systematic macroscopic mechanical testing. Lunar regolith simulants are therefore widely used to investigate the macroscopic mechanical behavior of lunar regolith. Most previous studies were conducted under ambient laboratory conditions, with limited consideration of temperature effects. In this study, direct shear tests were conducted on lunar regolith simulant specimens with relative densities $D_{\mathrm{r}}$ of 75%, 90%, and 100% under normal stresses of 50, 100, and 150 kPa and at temperatures of 25, 60, 120 and 180 °C. The effects of relative density, normal stress, and temperature on the shear response were systematically evaluated. The results showed that the peak and residual shear strengths generally increased with normal stress, whereas the effect of temperature on peak strength depended on relative density and normal stress. Three-dimensional laser scanning was used to reconstruct and quantitatively characterize the post-shear surface morphology, and its relationship with the measured shear response was examined. A damage-based phenomenological formulation incorporating a log-logistic function was used to parameterize the shear stress–displacement responses and to examine the fitted shear-stiffness parameter and phenomenological damage variable. The implications of the measured shear behavior for lunar drilling and sampling were also discussed. The study can provide laboratory-scale insights into the shear behavior of lunar regolith simulant relevant to lunar drilling and sampling. Full article

Magnesium alloys are attractive for temporary orthopaedic applications because of their biodegradability and favourable mechanical properties; however, their relatively rapid degradation under physiological conditions remains a challenge. In this study, the microstructural evolution, residual stress and electrochemical corrosion behaviour of WE43, a rare earth-containing magnesium alloy with yttrium, neodymium and zirconium as alloying elements, coated with titanium, were investigated as functions of deposition time using direct-current magnetron sputtering. Titanium coatings were deposited for 1, 1.5, 2 and 3 h, producing coating thicknesses of approximately 500, 650, 1000 and 1400 nm, respectively. Field-emission scanning electron microscopy, atomic force microscopy and grazing-incidence X-ray diffraction revealed progressive changes from fine-grained to dense and, subsequently, coarse-grained morphologies with increasing deposition time. The 2 h coating exhibited the largest crystallite size (27.17 ± 3.42 nm) and a moderate compressive residual stress of 605.3 ± 15.11 MPa. Potentiodynamic polarisation measurements showed that the 2 h coating produced the lowest corrosion current density (0.133 ± 0.026 mA/cm²) and calculated corrosion rate (2.93 ± 0.57 mm/year), representing a 67% reduction relative to independently measured, uncoated WE43 (8.87 ± 1.11 mm/year). The 3 h coating exhibited a higher compressive residual stress of 992.4 ± 21.7 MPa and a higher corrosion rate of 4.81 ± 0.74 mm/year, accompanied by localised microcracking after corrosion testing. Contact-angle measurements performed on the uncoated alloy and the 2 h coating showed an increase from 75.0 ± 2.1° to 83.0 ± 1.8°. Overall, the results indicated that corrosion performance was governed by the combined effects of coating morphology, crystallographic development and residual stress, with the 2 h deposition condition providing the most favourable balance under the present experimental conditions. Full article

In this study, laser powder bed fusion (PBF-LB) 022Cr17Ni12Mo2 steel plates with dimensions of 50 mm × 50 mm × 2 mm were fabricated using a laser power of 206 W, a scanning speed of 900 mm/s, a hatch spacing of 90 μm, a layer thickness of 30 μm, and an interlayer scanning rotation of 67°. The specimens were then subjected to solution treatment at 900–1100 °C for 30 min and at 950 °C for 30–120 min. Unlike previous ultrasonic studies on additively manufactured metals, which mainly focused on defect detection, elastic-constant characterization, or residual stress evaluation, this work investigates whether solution-treatment-induced changes in grain size and dislocation density can be quantitatively reflected by laser-ultrasonic attenuation and further correlated with yield strength. Laser ultrasonic nondestructive testing using a 1064 nm pulsed laser with a pulse width of 8 ns and a pulse energy of 500 mJ was combined with metallographic observation, EBSD characterization, XRD analysis, tensile testing, and microhardness measurement. The results show that the solution-treated samples retained a single-phase γ-austenitic structure, while microstructural recovery, weakening of PBF-LB-induced cellular substructures, and partial annihilation of cell-wall dislocations led to a reduction in KAM-derived dislocation density from 2.04 × 10¹⁴ m⁻² to 1.45 × 10¹⁴ m⁻² and a decrease in yield strength from 466.9 MPa to 407.4 MPa. Within the present dataset, the EBSD-equivalent grain size showed an apparent positive correlation with ultrasonic attenuation, while the KAM-derived dislocation density showed an empirical negative correlation with ultrasonic attenuation. However, ultrasonic attenuation should be interpreted as a combined microstructure-sensitive response rather than as a response controlled only by EBSD-equivalent grain size or dislocation density. Based on the empirical correlations among ultrasonic attenuation, EBSD-equivalent grain size, KAM-derived dislocation density, and yield strength, a preliminary attenuation-based calibration model was established for the present solution-treated samples. The model should be regarded as an in-sample empirical calibration within the present experimental range rather than a general Hall–Petch-based predictive model. The model showed good in-sample fitting performance, with (R²) values higher than 0.85 and a maximum in-sample fitting error of 3.85%. However, because the model was established and assessed using the same eight solution-treatment conditions, it should be regarded as a preliminary calibration model within the present experimental range rather than a general predictive model. This study demonstrates the potential of laser ultrasonic attenuation for non-contact evaluation of microstructural and mechanical-property variations in solution-treated PBF-LB 022Cr17Ni12Mo2 steel. Full article

Residual coal pillars retained in the overlying seam represent an important source of stress disturbance that can intensify mine pressure responses in underlying thick coal seam mining. Taking the downward mining of the Carboniferous–Permian dual-system extra-thick coal seam in the Xiao Coal Mine as the engineering context, this study integrates theoretical modeling and numerical simulation to characterize the disturbance extent of the underlying seam, the stress field redistribution in interlayer rock strata induced by the residual coal pillar, the evolution of advanced abutment pressure, and the variation in surrounding rock stress fields as the working face advances underneath the remaining coal pillar. A mechanical model is developed to describe the stress propagation and superposition induced by the coal pillar. Numerical simulation reveals that the vertical stress peak in the interlayer strata reaches 21.79 MPa near the overlying seam floor and 21.71 MPa at the underlying seam roof, and the peak stress in the coal seam roof beneath the pillar reaches 17.0 MPa, approximately 2.2 times the in situ stress, decreasing to 7.8 MPa at 42.5 m from the pillar. As the working face advances from 70 m to 10 m away from the monitoring section, the vertical stress peak on the goaf side increases from 21.19 MPa to 23.69 MPa, and on the solid coal side from 20.73 MPa to 23.46 MPa; the peak position shifts downward by approximately 0.7 m. The high floor stress from the overlying pillar superimposes strongly with the advanced abutment pressure, and the maximum disturbance width occurs at the peak abutment pressure point. Based on these findings, an optimized working face layout is proposed: an internal offset distance of 42.5 m between the mining roadway and the overlying remaining coal pillar. Following implementation of the optimized support scheme and floor grooving measures, field monitoring indicated reductions of 49.5% in roof subsidence and 60% in floor heave, with the maximum floor deformation limited to 256 mm. These results provide a theoretical basis for roadway layout and ground pressure control in downward mining of extra-thick coal seams under similar conditions. Full article

Type 1 diabetes (T1D) is characterized by autoimmune β-cell destruction, metabolic instability, and long-term susceptibility to vascular and renal complications. Oxidative stress has been widely implicated in these processes, but it is often described as a generalized consequence of hyperglycemia, not as a measurable and heterogeneous biological state. In this review, we propose exploratory redox phenotyping as a framework for characterizing oxidative stress in pediatric and early-stage T1D. This approach integrates biomarkers of antioxidant defense, lipid peroxidation, protein oxidation, DNA oxidation, and inflammation-associated redox activity to explore potentially distinct patterns of redox dysregulation. Key biomarker domains include enzymatic antioxidant systems, lipid-peroxidation products, protein- and DNA-oxidation markers, and inflammatory mediators, which may collectively characterize the intensity, molecular compartment, and possible clinical relevance of redox dysregulation. Across pediatric presymptomatic T1D, newly diagnosed disease, partial remission, and short-duration established T1D, longitudinal redox profiling may help distinguish stage-specific or transient metabolic responses from persistent oxidative dysregulation. These clinical phases are considered separately as they differ in immune activity, residual C-peptide secretion, glycemic exposure, and biological susceptibility. Redox phenotyping may also improve the design of antioxidant, mitochondrial, anti-inflammatory, and NRF2-targeted interventions by enabling biomarker-based patient selection. By defining oxidative stress as a stratifiable biological domain, this framework may advance precision risk assessment and guide more rational, targeted redox-directed therapies for children and individuals with early-stage T1D. At present, these proposed profiles remain hypothetical and require validation in prospective cohorts using standardized assays, reproducible thresholds, and clinically meaningful outcomes. Full article

Psychological distress is associated with problematic online shopping, but the relative and independent associations of depression, anxiety, and stress require careful evaluation without causal interpretation. This study examined their associations with continuous Online Shopping Addiction Scale (OSAS) scores after accounting for sociodemographic characteristics and online shopping frequency. A cross-sectional convenience sample included 438 adults in Türkiye (54.0% female among respondents reporting gender; mean age = 33.79, SD = 10.24); a total of 317 participated online and 121 completed printed questionnaires face to face. Pearson correlations were estimated in the full sample. Hierarchical regressions used a common complete-case sample (n = 375). Because residual diagnostics indicated heteroscedasticity and tail departures, HC3 robust standard errors and 95% confidence intervals were reported. Anxiety, depression, and stress showed statistically significant but modest correlations with OSAS total scores (r = 0.34, 0.32, and 0.27, respectively; all p < 0.001). In separate adjusted models, anxiety (ΔR² = 0.070; β = 0.283), depression (ΔR² = 0.068; β = 0.276), and stress (ΔR² = 0.042; β = 0.217) each increased explained variance (all p < 0.001). In the combined model, the DASS-21 block added ΔR² = 0.091; anxiety (β = 0.206, p = 0.002) and depression (β = 0.200, p = 0.001) had comparable independent associations, whereas stress did not (β = −0.050, p = 0.473). Online shopping frequency had the largest standardized coefficient among concurrent covariates (β = 0.280), but it is conceptually proximal to the OSAS outcome. The combined model explained 31.6% of the variance (adjusted R² = 0.291). Recruitment-mode comparisons were small and nonsignificant after Holm correction. Depression and anxiety were independently associated with higher OSAS scores, while most outcome variance remained unexplained. The findings do not establish temporal prediction, causation, or clinical diagnosis and should be interpreted in light of self-report measurement, construct overlap, residual confounding, and the digitally engaged convenience sample. Full article

According to engineering practice, fatigue failure of machine components is most frequently caused by tensile residual stresses arising at stress concentration zones, which justifies the detailed investigation and development of technologies capable of intentionally generating compressive residual stress. One of these technologies is burnishing, the effects of which are investigated using X-ray diffraction, a physical measurement method whose most significant advantage is the possibility of non-destructive material testing. However, the application of this method to aluminum and its alloys is limited due to their weak diffraction cross-section, which is further distorted by cold plastic deformation. As a possible solution to this problem, finite element modelling is applied, as it has long played an important role in the design and analysis of forming technologies. The planning and execution of the investigations are based on the full factorial experimental design method, using modern machining equipment, measuring devices, and simulation software. The results show that diamond burnishing generates substantial compressive residual stresses in tangential and axial directions, while the numerical simulations predict a compressive stress field extending to a depth of approximately 0.20 mm beneath the surface. The study not only highlights the life-enhancing effect of surface burnishing but also points out the difficulties of accurate evaluation, for which numerical simulation offers an effective solution. Full article

Metabolic syndrome (MetS) is a composite classification defined by heterogeneous combinations of cardiometabolic abnormalities. Several components have been associated with pancreatic cancer (PC), but studies often conflate long-term metabolic exposure, tumor-related prediagnostic metabolic change, and prognosis after diagnosis. This review critically evaluates these three settings. This narrative review searched PubMed, Scopus, and Web of Science through April 2026, prioritizing meta-analyses, prospective cohorts, Mendelian randomization studies, clinical studies, preclinical mechanistic evidence, and guidelines. Evidence was interpreted with attention to reverse causation, residual confounding, outcome definitions, and validation. Meta-analyses report a 25–34% higher PC risk among individuals with MetS, with a stepwise gradient across the number of metabolic components; hyperglycemia showed the strongest association among individual components (RR 1.55, 95% CI 1.42–1.70). However, MetS represents multiple versions of exposure, and the epidemiological and clinical evidence remains predominantly observational. Proposed mechanisms involving insulin signaling, adipokines, oxidative stress, epigenetic regulation, and the microbiome are largely preclinical and are not pancreas-specific. New-onset diabetes, rising HbA1c, and involuntary weight loss may mark occult pancreatic ductal adenocarcinoma, but available risk-enrichment models and biomarkers are insufficiently validated for routine screening. After diagnosis, metabolic status and body-composition measures have been associated with survival and perioperative outcomes, although confounding and cancer-related cachexia complicate interpretation. MetS is consistently associated with PC risk but is neither a single causal exposure nor an established target for PC prevention. MetS alone does not justify pancreatic imaging or biomarker testing. Lifestyle and pharmacologic treatment should follow established cardiometabolic indications; their effects on PC incidence remain unproven. Priorities include component-specific causal studies and prospective validation of risk-enrichment strategies. Full article

Metal additive manufacturing (MAM) enables the fabrication of geometrically complex and high-performance components but is accompanied by steep thermal gradients, repeated thermal cycling, phase transformation, residual stress, and deformation. These effects can reduce dimensional accuracy, manufacturing stability, fatigue resistance, and service reliability. This review systematically examines residual-stress and deformation behavior in MAM from the perspectives of formation mechanisms, influencing factors, measurement and prediction methods, mitigation strategies, and service-related consequences. The temperature gradient, mechanical constraint, and phase transition mechanisms are discussed as quantitatively coupled rather than independent processes. Comparative attention is given to process-specific differences, alloy-dependent thermophysical and metallurgical behavior, multi-track and multi-material interactions, and complex geometries. Destructive and non-destructive measurement techniques are compared in terms of penetration depth, spatial resolution, uncertainty, and cross-validation. Thermo-mechanical finite element, inherent strain, analytical, reduced-order, machine-learning, physics-informed, and digital-twin approaches are evaluated according to accuracy, efficiency, transferability, and applicability. Mitigation strategies are further compared considering residual-stress reduction, deformation control, manufacturing cost, and mechanical-property retention. Finally, challenges associated with uncertainty quantification, service environments, post-machining stress redistribution, and closed-loop control are identified. This review provides an integrated framework for selecting measurement, prediction, and mitigation approaches for reliable and high-precision MAM. Full article

Background: Quality of life (QoL) among university students is an important indicator of overall health and academic success. Although these factors are interrelated, few studies have simultaneously examined their structural associations with QoL among university students in Saudi Arabia. This study investigated the associations among demographic characteristics, lifestyle behaviors, psychological distress, and quality of life using structural equation modeling (SEM). Methods: We conducted a cross-sectional study among undergraduate students enrolled in public universities in Riyadh, Saudi Arabia. The survey included demographic characteristics, the Depression Anxiety Stress Scale-21 (DASS-21), the World Health Organization Quality of Life-BREF (WHOQOL-BREF), and measures of sleep quality, sleep duration, and physical activity. Confirmatory factor analysis was performed to evaluate the measurement model. We fitted SEM to examine associations among demographic characteristics, lifestyle behaviors, health status, and quality of life. Results: A total of 198 undergraduate students were included in the analysis. The measurement model demonstrated satisfactory psychometric properties. The SEM demonstrated acceptable model fit (χ²/df = 2.00, Comparative Fit Index = 0.937, Tucker–Lewis Index = 0.914, Root Mean Square Error of Approximation = 0.071, Standardized Root Mean Square Residual = 0.070). Male students reported poorer sleep quality (β = −0.405, p < 0.001), shorter sleep duration (β = −0.208, p = 0.019), and lower physical activity (β = −0.299, p < 0.001) than female students. Students with a GPA of 4.50 or above reported higher physical activity than those with lower GPAs (β = 0.182, p = 0.027). Better sleep quality (β = 0.169, p = 0.024) and very good or excellent self-rated health (β = 0.492, p < 0.001) were positively associated with quality of life, whereas sleep duration was not significantly associated with quality of life (p = 0.225). Conclusions: Quality of life among undergraduate students was associated with multiple interconnected demographic and lifestyle factors. Our findings highlight the importance of integrated university health-promotion strategies that simultaneously address sleep health, healthy lifestyle behaviors, and psychological well-being to improve students’ overall quality of life. Longitudinal studies should be conducted to clarify the temporal relationships among these factors. Full article

The aim of this work is to investigate the influence of different welding technologies on the mechanical properties and corrosion resistance of welded joints of SGH340D + ZMA steel with a Zn–Mg–Al (ZMA) protective coating. Two different welding technologies were used: the gas metal arc welding(GMAW) process at a welding speed of 0.8 m/min and laser welding at speeds of 2 and 4 m/min. Mechanical properties were determined using tensile testing and hardness testing. Corrosion resistance was estimated using a salt spray test. Residual stresses were determined experimentally using the drill hole method. The highest residual stresses were measured in GMAW-welded joints, while the lowest were measured in laser-welded joints at a speed of 4 m/min. The sample welded by laser at a speed of 4 m/min exhibited hardness values close to the upper acceptable limit, indicating that further increases in welding speed without preheating may lead to excessive hardness. All samples exhibited good corrosion resistance in a salt chamber. According to the results, increased welding speed reduced residual stresses but increased the risk of brittle fracture. Full article

Fms-related receptor tyrosine kinase 3 internal tandem duplication (FLT3-ITD) mutations occur in approximately 20–25% of patients with acute myeloid leukemia (AML) and are associated with increased relapse risk and inferior survival outcomes. Although measurable residual disease (MRD) has become a key prognostic tool for guiding post-remission treatment decisions, FLT3-ITD was historically considered a suboptimal MRD marker because of its subclonal nature, structural heterogeneity and dynamic behavior during disease evolution. In addition, FLT3-ITD has not yet been fully integrated into routine MRD monitoring due to methodological limitations and a lack of standardized workflows. The latest European LeukemiaNet (ELN)-DAVID 2025 recommendations stressed the use of ultra-high sensitivity (UHS) next-generation sequencing (NGS) technologies to detect FLT3-ITD MRD with improved precision, enabling reliable longitudinal tracking of patient-specific clones at very low variant allele frequencies (VAF). Indeed, despite prospective evidence supporting this approach remaining limited, FLT3-ITD-based MRD monitoring is emerging as a clinically relevant prognostic indicator, contributing to the identification of patients at increased risk of relapse and refining risk stratification, while also informing therapeutic decision-making, particularly in the peri-transplant setting. The present review summarizes the biological underpinnings of FLT3-ITD mutated (FLT3-ITD^mut) AML, discusses the methodological challenges of MRD detection, and critically evaluates the evolving role of MRD in refining relapse prediction, supporting post-remission therapy tailoring, and contributing to a harmonized framework for FLT3-ITD^mut AML management. Full article