Search Results (666)

Although epsilon-near-zero (ENZ) media have emerged as a promising platform for power dividers, the majority of existing designs are confined to fixed power splitting. In this work, two dynamically tunable power dividers using waveguide ENZ media are proposed by precisely modulating the internal magnetic field and the widths of the output waveguides. The first approach features a mechanically reconfigurable ring-shaped ENZ waveguide. By continuously re-distributing the magnetic field within the ENZ tunneling channels utilizing rotatable copper plates, arbitrary power division among multiple output ports is constructed. The second design integrates a rectangular-loop ENZ cavity into a substrate-integrated waveguide, with four positive–intrinsic–negative diodes embedded to dynamically activate specific output ports. This configuration steers electromagnetic energy toward output ports with varying cross-sectional areas, enabling on-demand control over both the power division and the number of output ports. Both analytical and full-wave simulation results confirm dynamic power division, with transmission efficiencies exceeding 93%. Despite differences in structure and actuation mechanisms, both designs exhibit flexible field control, high reconfigurability, and excellent transmission performance, highlighting their potential in advanced applications such as real-time wireless communications, multi-input–multi-output systems, and reconfigurable antennas. Full article

The pile–soil composite foundation system, highly acclaimed for its remarkable load-bearing capacity and limited deformation characteristics, has emerged as a fundamental element in geotechnical engineering practices. In the applications of adjacent slope engineering, such composite foundations are influenced by intricate loading scenarios. These scenarios involve both active vertical–horizontal combined load and passive soil-displacement forces generated due to the alteration of soil constraints. In this study, a self-designed movable retaining wall model box was employed. By applying different vertical and horizontal loads and controlling the rotation of the retaining wall around its base, a systematic investigation was conducted on the horizontal bearing mechanisms of single-pile and four-pile composite. The experimental data indicate that for every increment of 15 kPa in the vertical load, the horizontal bearing capacity experiences an average growth of approximately 18.9%, and the extreme value of the bending moment shows an average increase of 19.6. The analysis reveals coupled effects in internal force distribution and deformation patterns within load-bearing pile segments under concurrent active–passive loading conditions, while the embedded sections remain unaffected. Among four-pile composite foundations, the horizontal bearing mechanism of the front-row piles is consistent with that of a single-pile system. However, the maximum bending moments of the front-row and rear-row piles, compared to the single-pile system, have reached 0.68 times and 1.74 times, respectively. Notably, the bending moment of the front-row piles under the translational mode of the retaining wall is approximately 2.9 times that under the rotational mode, posing a potential risk of damage to the retaining structure, and necessary intervention is required. The results of this study provide a scientific basis for the force and deformation mechanism of piles at different positions in the composite foundation near foundation pit engineering, as well as their design for bending and shear resistance. Full article

As artificial intelligence (AI) becomes increasingly embedded within service-oriented High-Performance Work Systems (HPWSs), understanding its implications for employee well-being and organizational sustainability is critical. This study examines the relationship between AI service quality and job satisfaction, considering the mediating effect of perceived organizational justice and the moderating influence of supervisor support. Drawing on the ISS model, equity, organizational justice, and Leader–Member Exchange (LMX) theory, data were collected from a diverse sample of service sector employees through a cross-sectional design. The findings indicate that higher AI service quality significantly enhances job satisfaction, particularly in environments with strong supervisor support. Contrary to expectations, perceived organizational justice did not mediate the AI-satisfaction link, suggesting that perceived organizational justice constructs may be less influential in AI-mediated contexts. Instead, supervisor support emerged as a key contextual enabler, strengthening employees’ positive perceptions and emotional responses to AI systems. These results emphasize that technological optimization alone is insufficient for building sustainable service workplaces. Effective leadership and human-centered practices remain essential to fostering trust, satisfaction, and long-term engagement in digitally transforming organizations. This study offers practical and theoretical insights into integrating AI and human resource strategies in support of socially sustainable service systems. Full article

To enhance the structural performance of concrete-filled steel tube (CFST) columns, various strengthening techniques have been proposed, including the use of internal steel stiffeners, external wrapping with carbon fiber-reinforced polymer (CFRP) sheets, and embedded steel elements. However, the behavior of concrete-filled stainless-steel tube (CFSST) columns remains insufficiently explored. This study numerically investigates the axial performance of square CFSST columns internally strengthened with embedded I-section steel profiles under biaxial eccentric loading. Finite element (FE) simulations were conducted using ABAQUS v. 6.2, and the developed models were validated against experimental results from the literature. A comprehensive parametric study was performed to evaluate the effects of several variables, including concrete compressive strength (f_cu), stainless-steel yield strength (f_y), the depth ratio between the stainless-steel tube and the internal I-section (D_st/D_si), biaxial eccentricities (e_x and e_y), and tube thickness (t). The results demonstrated that the axial performance of CFSST columns was most significantly influenced by increasing the D_st/D_si ratio and load eccentricities. In contrast, increasing the concrete strength and steel yield strength had relatively modest effects. Specifically, the ultimate axial capacity increased by 9.97% when the steel yield strength rose from 550 MPa to 650 MPa and by 33.72% when the tube thickness increased from 3.0 mm to 5.0 mm. A strength gain of only 10.23% was observed when the concrete strength increased from 30 MPa to 60 MPa. Moreover, the energy absorption index of the strengthened columns improved in correlation with the enhanced axial capacities. Full article

The study presented in this paper is intended to be a contribution to the practical implementation of the “sustainability” concept, often misunderstood at times and incorrectly applied. The first sections describe a systematic procedure for a rigorous definition of “sustainability” and of “sustainable development” based on thermodynamics. A concept tightly connected with “sustainability” is “resource thriftiness”, i.e., the reduction in the anthropic extraction of irreplaceable supplies of fossil ores and fuels contained in the Earth’ crust and the reduction in the load posed on the environment by discharges, collectively referred to as “environmental conservation”: this is another concept that must be embedded in the definition of sustainability. An environmentally friendly society ought to concentrate on minimising such consumption by implementing an efficient and rational conversion of primary resources to final commodities while maintaining acceptable life standards. A thermodynamics-based approach can help identify the boundaries of the “sustainable region”: if sustainable development depends on a balance between primary input and final consumption, the internal allocation of the latter among citizens becomes a relevant parameter. The study presented in this paper introduces a direct link between demographics and pro capite final exergy use, showing how the age distribution of a society strongly impacts primary consumption. The paper presents some considerations about the quantitative link between the so-called “demographic pyramids” and the exergy budget of a country, with specific examples based on currently available data. Full article

This study explores the potential use of Polyethylene Terephthalate (PET) plastic bottles as void makers in short reinforced concrete columns under pure axial compression. Such a scheme promotes sustainability by decreasing the consumption of concrete and reducing the pollution that comes with the disposal of PET bottles. The experimental component of this study consisted of testing 16 reinforced concrete columns divided into two groups, based on the cross-section dimensions. One group contained eight columns of a length of 900 mm with a net cross-sectional area of about 40,000 mm², while the second group contained eight columns of a length of 1100 mm with a net cross-sectional area of about 62,500 mm². The diameter of the void within the small cross-section group was 100 mm and within the large cross-section group was 265 mm. The experimental program includes pairs of solid and corresponding void specimens with consideration of the size of the longitudinal steel reinforcement, lateral tie spacing, and concrete compressive strength. The tests are conducted using a universal test machine under displacement-controlled loading conditions with the help of strain gauges and Linear Variable differential transformers (LVDTs). The analysis of the test results showed that the columns that were embedded with a small void that occupied about 30% of the core area exhibited reductions of 9% in the ultimate capacity, 14% in initial stiffness, 20% in ductility, and 1% in residual strength. On the other hand, the columns that contained a large void occupying about 60% of the core area demonstrated reductions of 24% in the ultimate capacity, 34% in initial stiffness, and 26% in ductility, although the residual strength was slightly increased by 5%. The reason for the deficiency in the structural response in the latter case is because the void occupied a significant fraction of the concrete core. The theoretical part of this study showed that the ACI 318 code provisions can reasonably predict the uniaxial compressive strength of columns embedded with PET bottles if the void does not occupy more than 30% of the concrete core. This study confirmed that short columns embedded with relatively small voids made from PET bottles and subjected to pure axial compression create a balance between sustainability benefits and a structural performance tradeoff. Full article

In recent years, the increasing complexity of shield tunneling environments has made it critical to control the deformation of adjacent excavation structures and surrounding soils. This study employs numerical simulation using MIDAS GTS/NX to comprehensively analyze the spatial interaction factors between shield tunnels and wall-pile-anchor-supported foundation pits. Structural parameters of the retaining system and tunneling conditions are also evaluated to identify the key factors influencing construction-induced deformation. The results show that the maximum settlement of the adjacent retaining wall occurs when the tunnel burial depth reaches 1.4L, where L is the height of the diaphragm wall. In addition, when the horizontal distance between the tunnel and the excavation is less than 0.75D (D being the tunnel diameter), significant settlement deformation is observed in the nearby support structures. A linear correlation is also identified between the variation in tunnel crown settlement and the excavation depth of the overlying pit during tunnel undercrossing. Furthermore, sensitivity analysis indicates that increasing the embedment depth of the diaphragm wall effectively reduces horizontal displacement at the wall base. Increasing the wall thickness decreases displacement in the upper section of the wall. Similarly, increasing pile diameter and anchor length and diameter, while reducing the inclination angle of anchors, are all effective in minimizing the lateral displacement of the support structure. Full article

The embedded HVDC system is a form of DC power system that enhances regional power grids. This paper innovatively categorizes the typical application scenarios of embedded HVDC into three types: transmission section reinforcement, new energy delivery, and power supply zone interconnection. It further pioneers an exploration of the planning approach by breaking it down into three key aspects: identifying embedded HVDC construction demands, determining capacity, and selecting embedding points. For each scenario, specific planning steps are proposed to advance the practical application in reginal power grids. Finally, the planning methods are applied and verified through a case study in Jiangsu, China. Viable embedded HVDC schemes are obtained and compared with the AC approaches. Full article

Gibberellic acid (GA₃) and forchlorfenuron (CPPU) are widely used plant growth regulators for promoting berry enlargement in grapes. To evaluate the effects of GA₃ and CPPU on fruit quality and peelability of the seedless grape cultivar ‘Wuhe Cuibao’, and to determine the optimal concentration combination under the ecological conditions of Jinzhong, Shanxi Province, grape clusters were treated with varying concentrations of GA₃ and CPPU at full bloom and again 14 days later (young fruit stage), with water treatment as the control (CK). After maturation, the fruits were harvested for subsequent analysis of external morphology and internal quality parameters in both fruit clusters and individual berries. Paraffin embedding and sectioning were performed to conduct histological observations of cuticle thickness and cellular morphology in the treated fruits. The results indicate that GA₃ and CPPU treatments significantly enhanced the external quality of ‘Wuhe Cuibao’ grapes by effectively reducing fruit drop during cultivation. With the exception of T3 treatment, all treatments promoted both cluster elongation and berry enlargement. GA₃ treatment alone was more effective than CPPU treatment, and its effects were positively correlated with concentration. The T2 treatment resulted in the greatest increases in fruit length, berry weight, pedicel thickness, and pedicel tensile strength, surpassing the control (CK) by 35.53%, 43.65%, 88.92%, and 104.76%, respectively. The combined application of GA₃ and CPPU showed a synergistic effect, especially in T8, which led to the highest increases in cluster length (21.94%), cluster weight (41.92%), and berry width (13.49%) compared with the control. In addition, all treatments promoted the color transition of berries from green to yellow-green. Histological analysis showed a significant increase in cuticle thickness and in the size of both epidermal and subepidermal cells after treatment. In addition, all treatments increased fruit firmness and peel adherence in a concentration-dependent manner. GA₃ treatment alone produced the greatest increases in both fruit firmness and peel–flesh adherence, while the addition of CPPU treatment alleviated these effects. All treatments improved internal fruit quality by increasing the content of vitamin C, reducing sugars, soluble sugars, starch, and cellulose. GA₃ treatment alone significantly increased the levels of soluble solids, soluble proteins, and total phenols by 5.67%, 1.49%, and 5.38%, respectively, compared to the control (CK). In contrast, CPPU treatment alone significantly reduced the levels of these compounds. Notably, combined GA₃ and CPPU treatment in T5 led to the highest accumulation of vitamin C and reducing sugars, with increases of 3.78% and 62.36%, respectively, compared to the CK. Additionally, all treatments reduced anthocyanin and titratable acid levels, with a synergistic effect observed under combined treatment in lowering titratable acidity. Comprehensive evaluation revealed that the combined application of 50 mg·L⁻¹ GA₃ and 5.0 mg·L⁻¹ CPPU at full bloom and 14 days thereafter resulted in the greatest overall improvement in grape quality, offering theoretical and practical support for the efficient, high-quality cultivation of this cultivar. Full article

This study develops a vibration model for functionally graded material (FGM) plates with embedded planar cracks. Based on thin plate theory and von Kármán-type geometric nonlinear strain assumptions, the kinetic and potential energies of each region are derived. Displacement field trial functions are constructed according to boundary conditions, and the Ritz method is employed to determine natural frequencies and vibration modes under small deformation conditions. The investigation focuses on how crack parameters and material gradient coefficients affect vibration characteristics in exponentially graded FGM plates. The results show that natural frequencies decrease with increasing crack length, while crack presence alters nodal line patterns and mode symmetry. During free vibration, the upper and lower surfaces of the crack region exhibit relative displacement. Material gradient effects induce thickness–direction asymmetry, causing non-uniform displacements between the plate’s upper and lower sections. Full article

Background/Objectives: Fatigue is a highly prevalent and burdensome symptom among individuals with Marfan syndrome (MFS), yet its heterogeneity and underlying psychosocial and clinical correlates remain underexplored. This study aimed to identify and characterize distinct fatigue-related profiles in MFS patients using a data-driven cluster analysis approach. Methods: A cross-sectional study was conducted involving 127 patients with MFS from a specialized connective tissue disorder center in Italy. Participants completed self-reported measures of fatigue severity (Fatigue Severity Scale, FSS), depressive symptoms (Patient Health Questionnaire-9, PHQ-9), and insomnia (Insomnia Severity Index, ISI). The body mass index (BMI) and clinical data were also collected. A t-distributed stochastic neighbor embedding (t-SNE) analysis was performed to reduce dimensionality, followed by hierarchical clustering (Ward’s method), exploring solutions from k = 2 to k = 10. The optimal cluster solution was identified based on silhouette scores and clinical interpretability. Results: Three distinct clusters emerged: (1) a cluster characterized by low fatigue with minimal psychological and sleep-related symptoms (younger patients, lower PHQ-9 and ISI scores), (2) a cluster characterized by moderate fatigue with moderate psychological and sleep-related symptoms (intermediate age, moderate PHQ-9 and ISI scores), and (3) a cluster characterized by high fatigue with elevated psychological and sleep-related symptoms (older patients, higher PHQ-9, ISI, and FSS scores). Significant differences were observed across clusters in age, BMI, depressive symptoms, insomnia severity, and fatigue levels (all p < 0.05). Conclusions: Our findings highlight the heterogeneity of fatigue experiences in MFS and suggest the importance of profiling patients to guide personalized interventions. This approach may inform precision medicine strategies and enhance the quality of life for individuals with this rare disease. Full article

Background/Objectives: Epstein–Barr virus (EBV) detection patterns in lymphoproliferative disorders (LPDs) show significant geographical variation worldwide. Regional epidemiological data are essential for understanding viral distribution patterns and developing appropriate clinical surveillance strategies. This study aimed to determine EBV detection frequency in LPDs using available molecular and immunohistochemical methods in Western Mexico. Methods: We conducted a cross-sectional study of 200 formalin-fixed paraffin-embedded tissue samples from patients diagnosed with LPDs (2015–2019) at Hospital Civil de Guadalajara. EBV detection combined with real-time PCR targeting the BNTp143 gene and immunohistochemistry for LMP-1 protein. Cases were classified following current WHO criteria. Statistical analysis included multivariate logistic regression, diagnostic concordance assessment, and age-stratified analysis. Results: EBV detection frequency reached 35.5% overall, with marked differences between neoplastic (53.9%) and reactive LPDs (24.2%) (OR: 3.515; 95% CI: 1.859–6.645, p < 0.001). Hodgkin lymphoma showed the highest detection rate (80.6%), significantly exceeding non-Hodgkin lymphoma (39.3%) (OR: 6.43; 95% CI: 2.08–19.41, p = 0.001). Age-stratified analysis revealed predominant adult involvement (49.1% vs. 22.0% in young adults, p = 0.025). We identified three epidemiological categories based on detection probability patterns. Conclusions: This study represents the first comprehensive molecular and immunohistochemical characterization of Epstein–Barr virus in lymphoproliferative disorders from Western Mexico, establishing distinct epidemiological patterns that align with Latin American regional characteristics. The validated methodology provides a reproducible framework for multi-center studies, while the epidemiological data serve as an essential baseline for future longitudinal research and resource optimization in similar healthcare settings. Full article

Background: Dental professionals face high levels of occupational stress, which intensified during the COVID-19 pandemic, contributing to increased burnout, diminished well-being, and signs of accelerated biological aging. This systematic review explores the role of physical activity as a protective factor for mental and physical health, with a focus on promoting resilience and long-term occupational sustainability in a post-pandemic volatile, uncertain, complex, and ambiguous (VUCA) environment. Methods: A systematic review was conducted in accordance with PRISMA 2020 guidelines. Studies published between 2000 and 2024 were identified through PubMed, Scopus, and the Cochrane Library using MeSH terms related to dentistry, physical activity, stress management, and occupational health. Of 850 records screened, 28 studies were included: 24 cross-sectional, 2 systematic reviews, 1 retrospective, and 1 case–control study. Inclusion and quality appraisal followed standardized criteria. Results: The included studies consistently showed that physical activity was associated with reduced burnout, improved psychological well-being, enhanced postural function, and potential markers of slowed biological aging in dental professionals. Several studies reported moderate-to-strong associations, with effect sizes ranging from small improvements in perceived stress scores to substantial reductions in MSD prevalence. Interventions combining exercise with ergonomic education, stress management, and institutional support demonstrated the stronger and more consistent benefits for professional sustainability. Conclusions: Physical activity, when integrated into comprehensive workplace wellness frameworks, significantly enhances the mental and physical resilience of dental professionals. Embedding movement, ergonomics, and psychosocial support into practice environments offers a promising strategy for safeguarding long-term workforce sustainability and improving public health outcomes. Full article

This study examines how Business Intelligence (BI) capabilities influence environmental performance (EP) in manufacturaing supply chains, with a focus on the mediating roles of Green Supply Chain Management (GSCM) and Supply Chain Integration (SCI) and the moderating role of Blockchain Integration (BCI). Addressing a critical research gap in digital sustainability, particularly in emerging markets, this study integrates the Resource-Based View (RBV) theory, Natural Resource-Based View (NRBV) theory, and Dynamic Capabilities View (DCV) theory to develop a theoretically grounded framework. Data were collected via a cross-sectional survey of 231 managers in 65 firms in Jordan and analyzed using Partial Least Squares Structural Equation Modeling (PLS-SEM). Findings reveal that while BI does not directly enhance EP, it significantly improves GSCM and SCI, which in turn mediate its influence on EP. GSCM fully mediates this relationship, while SCI provides partial mediation. BCI did not demonstrate a significant moderating effect. These results suggest that BI must be embedded within green and integrative operational systems to drive sustainability outcomes. This study contributes novel insights into how digital capabilities translate into environmental gains in underrepresented contexts and provides actionable guidance for firms and policymakers aiming to align digital transformation with environmental objectives. Full article

Background/Objectives: Microvascular complications are a major source of disability in type 2 diabetes mellitus (T2DM). We investigated whether body composition indices derived from multifrequency bioelectrical impedance analysis (BIA) independently predict neuropathy, retinopathy, nephropathy, and stroke, and whether they improve risk discrimination beyond the established clinical variables. Methods: In this cross-sectional analytical study (March 2024–February 2025), 124 adults with T2DM ≥ 12 months attending the outpatient diabetes clinic of the Universidad Técnica de Ambato (Ecuador) were enrolled. After an overnight fast and 15 min supine rest, thirteen whole-body BIA metrics including skeletal muscle mass (SMM), intracellular water (ICW), phase angle (PhA), and visceral fat area (VFA) were obtained with a segmental analyzer (InBody S10). Complications were ascertained with standard clinical and laboratory protocols. Principal component analysis (PCA) summarized the correlated BIA measures; multivariable logistic regression (adjusted for age, sex, diabetes duration, HbA1c, BMI, and medication use) generated odds ratios (ORs) per standard deviation (SD). Discrimination was assessed with bootstrapped receiver-operating characteristic curves. Results: The first principal component, driven by SMM, ICW, and PhA, accounted for a median 68% (range 65–72%) of body composition variance across all complications. Each SD increase in SMM lowered the odds of neuropathy (OR 0.54, 95% CI 0.41–0.71) and nephropathy (OR 0.70, 0.53–0.92), whereas VFA raised the risk of neuropathy (OR 1.55, 1.22–1.97) and retinopathy (OR 1.47, 1.14–1.88). PhA protected most strongly against stroke (OR 0.55, 0.37–0.82). Composite models integrating SMM, PhA, and adiposity indices achieved AUCs of 0.79–0.85, outperforming clinical models alone (all ΔAUC ≥ 0.05) and maintaining good calibration (Hosmer–Lemeshow p > 0.20). Optimal probability cut-offs (0.39–0.45) balanced sensitivity (0.74–0.80) and specificity (0.68–0.72). Conclusions: A lean tissue BIA signature (higher SMM, ICW, PhA) confers independent protection against neuropathy, retinopathy, nephropathy, and stroke, whereas visceral adiposity amplifies the risk. Because the assessment is rapid, inexpensive, and operator-independent, routine multifrequency BIA can be embedded into diabetes clinics to triage patients for early specialist referral and to monitor interventions aimed at preserving muscle and reducing visceral fat, thereby enhancing microvascular risk management in T2DM. Full article