Search Results (327)

A brief review of various existing mathematical formulations of the uncertainty relations in quantum mechanics, containing variances of two or more non-commuting operators, is given. In particular, inequalities for the products of higher-order moments of a coordinate and a momentum are considered, as well as inequalities making the uncertainty relations more accurate when additional information about a quantum system is available (for example, the correlation coefficient or the degree of mixing of a quantum state characterized by the trace of the squared statistical operator). The special cases of two, three, and four operators are discussed in detail. Full article

Research concerning green marketing has predominantly focused on consumer behavior. However, aspects such as the extent to which Small and Medium Enterprises (SMEs) embrace green marketing values, their ability to implement the green marketing mix, and the integration of green marketing into their business culture are critically important. This research aims to provide the 4P (product, price, place, and promotion)-focused green marketing literature with a measurement tool to assess how SMEs implement green marketing practices. The study employed a descriptive design and possesses an exploratory nature. Scale development involved two stages: First, analyses were conducted on a pre-test sample of 159 individuals, revealing the initial scale structure. Second, these analyses were repeated on a larger group of 387 participants. The scale was finalized by confirming the consistency of results across both analyses. Statistical Package for the Social Sciences (SPSS) version 24 and Analysis of Moment Structures (AMOS) version 24 were utilized for descriptive statistics and the scale development process. The final validated 12-item scale demonstrates a robust three-factor structure (“Environmental Promotion”, ”Green Packaging”, and ”Green Distribution”), explaining 62.6% of the total variance. The scale exhibits excellent psychometric properties, including high internal consistency (Cronbach’s α = 0.912), strong model fit from Confirmatory Factor Analysis (CFA), and both convergent and discriminant validity, as indicated by an Average Variance Extracted (AVE) value of 0.605. The scale is deemed applicable to larger populations. Full article

Preserving heritage sites is a complex challenge that requires multidisciplinary approaches, combining scientific accuracy with cultural and historical sensitivity. In alignment with UNESCO’s conservation guidelines, this study investigated the airflow dynamics and wind-induced structural effects within ancient architecture using advanced computational fluid dynamics (CFD). The study site was the Na Phra Meru Historical Temple in Ayutthaya, Thailand, where the shear stress transport $k-\omega$ turbulence model was applied to analyze distinctive airflow patterns. A high-precision 3D computational domain was developed using Faro focus laser scanning technology, with the CFD results being validated based on onsite experimental data. The findings provided critical insights into the temple’s ventilation behavior, revealing strong correlations between turbulence characteristics, wind speed, temperature, and relative humidity. Notably, the small slit windows generated complex flow mixing, producing a large internal recirculation zone spanning approximately 70% of the central interior space. In addition to airflow distribution, the study evaluated the aerodynamic forces and rotational moments acting on the structure based on five prevailing wind directions. Based on these results, winds from the east and northeast generated the highest aerodynamic loads and rotational stresses, particularly in the lateral and vertical directions. Overall, the findings highlighted the critical role of airflow and wind-induced forces in the deterioration and long-term stability of heritage buildings. The study demonstrated the value of integrating CFD, environmental data, and structural analysis to bridge the gap between conservation science and engineering practice. Future work will explore further the interactions between wall moisture and the multi-layered pigments in mural paintings to inform preservation practices. Full article

This study aims to analyze the determinants of bank profitability in Angola by employing panel data econometric models, specifically, the Generalized Method of Moments (GMM), to assess the impact of internal and external factors on the financial indicators ROE, ROA, and NIM for the period 2016 to 2023. The results reveal that credit risk, operational efficiency, and liquidity are critical determinants of banking performance. Effective credit risk management and cost optimization are essential for the sector’s stability. Banking concentration presents mixed effects, enhancing net interest income while potentially undermining efficiency. Economic growth supports profitability, whereas inflation exerts a negative influence. The COVID-19 pandemic worsened asset quality, increased credit risk, and led to a rise in non-performing loans and provisions. Reforms implemented by the National Bank of Angola have contributed to strengthening the banking system’s resilience through restructuring and regulatory improvements. The rise of digitalization and fintech presents opportunities to enhance financial inclusion and efficiency, although their success relies on advancing financial literacy. This study contributes to the literature by providing updated empirical evidence on the factors influencing bank profitability within an emerging economy’s distinctive institutional and economic context. Full article

The relationship between ESG and firm performance is complex and tends to yield mixed results globally. In South Africa, ESG implementation is still in its infancy stage due to economic and developmental challenges. Despite these challenges, the JSE introduced sustainability disclosure guidelines in 2022 to enhance ESG adoption in South Africa. Thus, the study seeks to understand the impact of ESG and firm size on the financial performance of JSE-listed firms in South Africa. The study utilised the JSE Top 40 firms for the period from 2002 to 2022. Furthermore, the study employed a two-step System Generalised Method of Moments, to estimate the impact of total ESG and individual dimensions of ESG on firm financial performance. Additionally, the study examined the moderating effects of firm size on the relationship between financial performance and ESG. The results revealed a positive and significant relationship between total ESG and firm financial performance. However, the findings regarding individual ESG dimensions and firm performance are mixed. Firm size has a moderating effect on the relationship between ESG and firm financial performance. The implication of these findings for South Africa is increased foreign direct investment from green investors and listed firms seriously considering ESG in their operations. Full article

Composite rotors, attributing to their leveraging characteristics of the light weight, high strength, high rigidity, corrosion resistance, and low noise, can significantly reduce the moment of inertia and enhance equipment operational efficiency. Using carbon fiber/glass fiber hybrid-reinforced resin–matrix composites as the rotor base material, the radial stability of a rotor can be effectively increased by regulating the fiber volume content. Meanwhile, the introduction of glass fiber not only enables the transition between the metal hub and composite rim but also optimizes the cost structure of the composite system, overcoming the economic bottleneck of single carbon fiber-reinforced resin–matrix composite rotors. This paper employs the finite element method to analyze a three-dimensional model of a composite rotor, investigating the performance of its metal hub and hybrid-reinforced resin–matrix composite rim. According to the radial stress distribution of the composite rotor during operation, the mixing ratio of carbon fiber/glass fiber is adjusted. The high-speed rotation condition of the composite rotor at 18,000 revolutions per minute is simulated to verify its safety and reliability. Full article

To study the coupling mechanism between droplet evaporation characteristics and flame propagation, in this paper, the ignition process in a single dome lean direct injection combustor is simulated by the Large Eddy Simulation (LES) method. A new concept, i.e., available droplet, and a new parameter, i.e., available equivalence ratio, are innovatively introduced to accurately quantify fuel–air mixing characteristics and reveal flame propagation mechanisms. Simulation results show that the temporal variations in the locally available equivalence ratio during the ignition process can serve as a reliable indicator to identify the flame propagation direction. Moreover, the results show that during the ignition process, available droplets are mainly distributed in the regions where temperatures range from 650 K to 1200 K. The number percentage of available droplets in the combustor increases approximately exponentially to about 2.5% after 40 ms from the ignition. Additionally, the temperature fields and distributions of the available equivalence ratio at different moments during the ignition are also computed and analyzed. The results show that the volume percentage of flammable regions gradually increases from the ignition and eventually stabilizes at about 10% after 8 ms from the ignition. This result shows that during the ignition, the increase in regions whose available equivalence ratios fit flammability is a critical factor for ensuring stable flame development. The available droplet and available equivalence ratio can bridge the gap between droplet-scale evaporation and combustor-scale ignition dynamics, offering an analytical tool for optimizing ignition criteria in aero engine combustors. By analyzing the distributions and evolutions of available fuel rather than fuel vapor, this work can be utilized in design strategies for reliable ignition in extreme conditions. Full article

In coastal regions with thick, soft soil deposits, bridge pile foundations are susceptible to lateral displacements induced by the construction of adjacent seawalls. This study employs a three-dimensional nonlinear finite element framework to investigate the lateral deformation mechanisms of rock-socketed bridge piles under seawall surcharge loading in soft soils, considering the effects of both immediate construction and long-term consolidation. A parametric analysis is performed to evaluate the effectiveness of deep cement mixing (DCM) piles in mitigating pile displacements, focusing on key design parameters, including DCM pile length, area replacement ratio, and elastic modulus. The results reveal that horizontal pile displacements peak at the pile head post-construction (25 days: 25 mm) and progressively decrease during consolidation, shifting the critical displacement zone to mid-pile depths (20 years: 12 mm). Bending moment analysis identifies persistent positive moments at the rock-socketed interface. Increasing pile stiffness marginally reduces displacements (a < 1 mm reduction for a 22% diameter increase), while expanding the seawall–pile distance to 110 m decreases displacements by 72–84%. DCM pile implementation significantly mitigates short-term (48% reduction) and long-term (54% reduction) displacements, with optimal thresholds at a 30% area replacement ratio and a 40.5 MPa elastic modulus. This study provides critical insights into time-dependent soil–pile interaction mechanisms and practical guidelines for optimizing coastal infrastructure design to minimize surcharge-induced impacts on adjacent pile foundations. Full article

Background: Gait decline in older adults is closely linked to reduced ankle propulsion and a compensatory reliance on proximal joints. This randomized trial investigated whether dynamic stability training using water inertia can improve gait mechanics and redistribute lower-limb joint moments in older women. Hypotheses: (1) The training would improve gait speed, stride length, and cadence. (2) The ankle plantar flexor moment and positive mechanical work would increase, while hip extension moment would decrease. Method: Twenty-four women aged 65 years and older were randomly assigned to either an experimental or control group. The experimental group wore a water-filled aquavest, and the control group wore a weighted vest. Both groups performed the same training program twice weekly for 12 weeks. Outcome measures included gait speed, stride length, cadence, ankle plantar flexion moment, hip extension moment, and positive mechanical work during terminal stance. A two-way mixed (between–within) analysis of variance (ANOVA) evaluated the group × time interaction effects. Results: Significant group × time interactions were found for gait speed (p < 0.001), stride length (p < 0.001), ankle moment (p = 0.017), and positive work (p < 0.001). Cadence increased in both groups over time (p < 0.05), with no interaction. The hip moment declined slightly in the experimental group. Conclusions: Water inertia load training enhanced propulsion and promoted an ankle-dominant gait, supporting its use to improve gait function and reduce proximal compensation in older women. Full article

In this study, we propose the study of an innovative precipitation prototype designed by ResourSEAs, guided by a CFD-PBM (Computational Fluid Dynamics and Population Balance Model) approach, aiming to understand the influence of reactant concentration and nozzle orientation on precipitation processes. The first part of the study examines the effect of reactant concentration on supersaturation and the zeroth-order moment ($m_0$) within a controlled flow and turbulence fields. Three different concentrations of ${\mathrm{Mg}}^{2+}$ (0.1, 0.3, and 0.6 M) and ${\mathrm{OH}}^{-}$ (0.005, 0.01, and 0.02 M) were tested, resulting in varying supersaturation profiles and $m_0$ fields. Our results show that, under equal turbulence conditions, increasing the concentration of reactants beyond a certain point actually slows down mixing, which in turn hinders the generation of supersaturation. As a result, supersaturation profiles become nearly identical to those of lower concentrations, despite having consumed more reactants. The second part of this study focuses on the effect of nozzle orientation and positioning along the prototype axis on reactant mixing and particle formation. The simulations reveal that nozzle orientation has a significant impact on the formation of primary particles, especially when positioned in low-velocity regions, leading to slower mixing and greater particle growth. Conversely, high-velocity regions promote faster mixing and more intense aggregation. These findings highlight the interplay between concentration, nozzle orientation, and flow conditions in determining precipitation efficiency, offering insights for optimizing reactor design in industrial applications. Full article

Background: Previous studies have tested the association between the COL5A1 rs12722 polymorphism and the risk of anterior cruciate ligament (ACL) injury. Overall, their results are contradictory because most studies used relatively small samples and data from ACL ruptures during sport activities have been mixed with ruptures suffered in non-sporting contexts. Objective: To examine the association between the COL5A1 rs12722 polymorphism and the prevalence of ACL rupture in a homogeneous sample of professional male football players. Methods: A total of 268 professional male football players participated in this study. The COL5A1 rs12722 genotype (CC, CT and TT) was obtained from each player using genomic DNA samples obtained from a buccal swab and measured with PCR RFLP. Players with history of ACL rupture during their professional career were identified by the medical staff of each team. Only ACL injuries obtained during football exposure were considered for this investigation. In this process, we identified 49 ACL ruptures pertaining to 43 players suffered between 2013 and 2024. The situational pattern (i.e., attacking or defending, type of football action, moment of the season, match/training exposure, etc.) was also obtained for each injury. A sub-analysis of non-contact ACL ruptures was conducted, as these injuries are more likely to be influenced by genetic factors. Results: The distribution of genotypes was similar in players with history of ACL rupture (n = 43; CC/CT/TT, 24.4/48.9/26.7%) and with no history of ACL rupture (n = 225; 25.3/49.8/24.9%; p = 0.973). Overall, the prevalence of players with history of ACL injury was 16.2% for the whole group of CC players (11 out of 68 players), 16.4% for whole group of CT (22 out of 135 players) and 15.2% for the group of TT players (10 out of 66 players; p = 0.973). However, the COL5A1 rs12722 genotype affected the dominance of the injured leg (p = 0.012), the type of action that originated the injury (p = 0.047), and the distribution of non-contact ACL injuries depending on the time of the match (p = 0.020). Specifically, CC players suffered ruptures predominantly in the dominant leg, when landing or reaching (offensive actions) and in the last 15 min of the match (all p < 0.050). On the contrary, TT players had ACL ruptures predominantly in their non-dominant leg, when pressing the opponent (defensive actions) and in the first 15 min of the match (all p < 0.050). Conclusion: There was no association between any of the COL5A1 rs12722 genotypes and the overall prevalence of ACL rupture in professional football players. However, the COL5A1 rs12722 polymorphism appeared to influence specific characteristics of the injury, such as the type of action leading to the rupture and the timing within the match, suggesting a potential genetic contribution to injury susceptibility. Full article

Approach sequencing is important for multiple unmanned electric vertical take-off and landing (eVTOL) vehicles landing in vertiport. In this study, the additional intermediate transition ring (AIR) approach procedure in a balanced traffic flow scenario, the single ring movement-allowed (SRMA) approach procedure in an imbalanced traffic flow scenario, and the additional ring and allowing of movement (ARAM) approach procedure in a mixed scenario are proposed and designed to improve the efficiency of approach sequencing. Furthermore, a priority loss classification method is proposed to consider the unmanned eVTOL flight priority difference. Finally, a multi-objective optimization model is constructed with the constraints of inflow, outflow, moment continuity, flow balance, and conflict avoidance. The objectives are minimizing the power consumption, total operation time, and priority loss. Comparison experiments are conducted, and the final results demonstrate that the ARAM approach procedure can reduce the average holding time by 8.4% and 7.6% less than the branch-queuing approach (BQA) and AIR in a balanced traffic flow scenario, respectively. The ARAM approach procedure can reduce the average holding time by 6.5% less than BQA in an imbalanced traffic flow scenario. Full article

Background/Objectives: A 43-year-old male presented with neurological symptoms and asymptomatic cardiac dysfunction, left ventricular hypertrophy, and impaired global longitudinal strain with apical sparing, associated with elevated NT-proBNP. Methods: Multimodality imaging (bone scintigraphy and cardiac magnetic resonance) revealed cardiac amyloid deposition. Genetic testing confirmed variant transthyretin amyloidosis (ATTR) with mixed phenotype. Results: Treatment with tafamidis 20 mg for stage I polyneuropathy, available at that moment, was initiated with good neurological outcome. Three years later, cardiac function deteriorated, following a moderate COVID-19 infection, with heart failure symptoms and reduced ventricular and atrial functions. For progressive ATTR cardiomyopathy, we intensified therapy to tafamidis free acid 61 mg, associated with SGLT2 inhibitor, spironolactone, and furosemide with subsequent improvements of symptoms and stabilization of imaging findings. Conclusions: This case emphasizes the importance of multimodal imaging in early detection, monitoring, and guiding individualized management in ATTR cardiomyopathy. Full article

Background: Somatic symptoms of stress are a major concern among the general population, given their severity and overall burden. Objectives: This pilot randomized controlled study (RCT) aimed to assess the effectiveness of frequency-specific microcurrent (FSM) therapy alone (experimental group 1 [EG1]) and combined with a relaxation intervention (experimental group 2 [EG2]), compared to a relaxation intervention alone (active control group [ACG]) and combined with placebo (passive control group [PCG]), to determine the need for a future definitive RCT. Methods: Participants with clinically significant levels of stress were recruited and assessed at three moments (i.e., baseline assessment [T0], at the end of six sessions [T1], and at the end of 12 sessions [T2]) on somatic symptoms and satisfaction with life (primary outcomes), perceived stress, emotional distress, emotional states, and emotion regulation (secondary outcomes). A total of 85 participants completed T0, of whom 58 were randomized into four groups. Results: Using linear mixed models, differences between groups revealed that the participants receiving FSM therapy reported fewer somatic symptoms and negative emotions than those who received relaxation, at T1. Within-group analysis showed that somatic symptoms and satisfaction with life significantly improved after six or twelve sessions of FSM therapy as well as after relaxation. There were also significant improvements in perceived stress, emotional distress, emotion regulation, and emotional states (negative emotions, self-efficacy, and serenity), after six and/or 12 sessions of FSM therapy or relaxation. Conclusions: The results suggest that FSM may be a promising treatment for addressing somatic complaints and negative emotional states, supporting the implementation of a definitive RCT. Full article

The study examined the influence of foreign aid on foreign direct investment (FDI) in upper-middle-income economies using panel data (2011–2021) analysis methods such as two-stage least squares (2SLS) and system GMM (generalized methods of moments). The study also explored if human capital development enhanced foreign aid’s influence on FDI in upper-middle-income economies during the same timeframe. The conflicting, divergent, and mixed results and views on the relationship between foreign aid, human capital development, and foreign direct investment (FDI) motivated the undertaking of this study to fill in the existing gaps. Apart from FDI enhanced by its own lag, foreign aid significantly improved FDI (under system GMM). FDI was also improved significantly by human capital development across all two panel methods. Under 2SLS and system GMM, foreign aid significantly improved FDI through the human capital development channel. To promote FDI inflows, upper-middle-income economies should develop and implement policies aimed at attracting foreign aid and enhancing the development of human capital. The study suggests that further research on threshold regression analysis on foreign aid–FDI nexus in upper-middle-income economies could better help develop an FDI policy that is beneficial toward economic growth. Full article