Search Results (10,831)

A bolt loosening detection method based on the summation coefficient of the absolute spectrum ratio technique is proposed to address the prevalent issue of bolt loosening in mechanical connections. This proposed method involves initially collecting vibration and rotation speed signals of the motor bolt connection structure, acquiring the baseline spectrum curve of a healthy structure and the spectrum curves of non-healthy structures under different degrees of bolt looseness through chirp Fourier transform (CFT). Subsequently, the spectrum ratio curves between healthy and non-healthy structures are calculated for different degrees of bolt loosening, and then the Summation Coefficient of Absolute Spectrum Ratio (SCASR) is defined to indicate the looseness. In the mathematical model, a linear relationship is observed between the SCASR and the frequency shift of the resonance peak. To standardize the results of bolt loosening detection, the SCASR could be divided by the number of points in the fixed frequency band to obtain the average of SCASR as the detection index for bolt loosening. Finally, a linear fitting equation is established between the bolt torque and the average of SCASR, so that the change in the average value can be used to determine whether the bolt is loose and evaluate the severity of bolt looseness. The detection performance of this proposed method has been effectively validated through both simulation and experiments. Experimental results indicate that the proposed method can effectively detect bolt loosening, particularly in its early stages, using low-frequency band data in three axes. Full article

The primary objective of this study is to validate the Sustainability Consciousness Questionnaire (SCQ) for the Portuguese population, ensuring its reliability and applicability across the dimensions of knowledge, attitudes, and behaviours related to sustainability. This validation is crucial for ensuring the SCQ captures local cultural nuances and provides reliable data to inform educational and policy strategies for promoting sustainability. To achieve this goal, a quantitative methodology was adopted, involving the translation and cultural adaptation of the SCQ into Portuguese. Data were collected from a convenience sample of 630 participants, aged 17 to 83, using an online platform. Ethical procedures were rigorously followed, including obtaining informed consent from all participants and ensuring data confidentiality. The factor structure of the SCQ was analysed using structural equation modelling (SEM). The analysis confirmed a three-dimensional factor structure aligned with the environmental, social, and economic pillars of sustainability, as well as significant correlations between these dimensions and real-world sustainable practices such as recycling and energy conservation. The results confirmed the construct validity of the SCQ, demonstrating robust reliability indicators across its scales and acceptable model fit indices (CFI = 0.860; TLI = 0.851; RMSEA = 0.045). These findings highlight the questionnaire’s utility as a measurement tool for sustainable consciousness in the Portuguese context. The SCQ provides a valuable resource for educators, policymakers, and researchers. For instance, educators can use the SCQ to identify gaps in students’ sustainability knowledge, policymakers can prioritise areas for intervention based on public attitudes, and researchers can explore relationships between awareness and sustainable behaviours to design effective programs. Furthermore, this study contributes to Sustainable Development Goal 4 (Quality Education) by enabling data-driven strategies to integrate sustainability education into curricula, fostering a deeper understanding of sustainable practices and behaviours essential for achieving global education goals. Full article

To establish a finite element model that accurately represents the dynamic characteristics of actual super high-rise building and improve the accuracy of the finite element simulation results, a finite element model updating method for super high-rise building is proposed based on the response surface method (RSM). Taking a 120 m super high-rise building as the research object, a refined initial finite element model is firstly established, and the elastic modulus and density of the main concrete and steel components in the model are set as the parameters to be updated. A significance analysis was conducted on 16 parameters to be updated including E1–E8, D1–D8, and the first 10 natural frequencies of the structure, and 6 updating parameters are ultimately selected. A sample set of updating parameters was generated using central composite design (CCD) and then applied to the finite element model for calculation. The response surface equations for the first ten natural frequencies were obtained through quadratic polynomial fitting, and the optimal solution of the objective function was determined using a genetic algorithm. The results of the engineering case study indicate that the errors in the first ten natural frequencies of the updated finite element model are all within 5%. The updated model accurately reflects the current situation of the super high-rise building and provides a basis for super high-rise building health monitoring, damage detection, and reliability assessment. Full article

In recent years, businesses have faced growing pressures from stakeholders, including investors, customers, and regulators, to adopt sustainable practices. These pressures stem from the global focus on environmental, social, and governance (ESG) criteria and their association with risk management and corporate resilience. As a result, understanding the connection between sustainability and performance indicators, such as return on equity (ROE) and return on assets (ROA), is crucial to determine whether sustainable practices positively influence financial outcomes or primarily serve to address external expectations. This study seeks to bridge the gap between theoretical frameworks and empirical evidence by employing a rigorous methodological approach—Structural Equation Modeling (SEM)—to assess the impact of sustainability practices on key performance measures. The inclusion of a diverse range of industries from the US and Europe enhances the relevance of the findings, as it facilitates their generalization across developed economies where sustainability initiatives are highly prioritized. Our results are consistent with prior research demonstrating a positive relationship between sustainability and financial performance, particularly in high-development contexts over a medium-term period. These findings carry important implications for managers and policymakers, emphasizing that sustainability is not a compromise but a catalyst for economic and financial profitability. This study contributes to the literature by illustrating how sustainability can simultaneously advance ethical objectives and enhance financial performance, establishing it as a critical area of focus for both academics and practitioners. Full article

Introduction: Social media addiction (SMA) and internet addiction (IA) are increasingly prevalent, impacting mental health (MH) globally. This study investigates the mediating roles of mindfulness and social capital (SC) in the relationship between SMA, IA, and MH among Ethiopian high school and university students, contributing to the Sustainable Development Goal (SDG) 3 of good health and well-being. Methods: A cross-sectional study was conducted with 1160 university and 1473 high school students in Dessie, Ethiopia. Participants completed validated questionnaires assessing SMA, IA, mindfulness, SC, and MH. Structural Equation Modeling (SEM) with a multi- mediation Model (SMM) was used to examine the hypothesized relationships. Results: SEM revealed that both SMA and IA had a direct negative effect on mindfulness, SC, and MH in in both high school and university students. Notably, mindfulness and SC significantly and positively predicted MH, indicating their protective role against the negative effects of SMA and IA. Furthermore, both mindfulness or SC fully or partially mediated the relationship between SMA, IA, and MH, highlighting their crucial role in explaining the association. Conclusions: This study provides evidence for the crucial roles of mindfulness and SC in buffering the negative effects of SMA and IA on MH among Ethiopian students. The findings highlight the need for educational and health interventions that foster mindfulness and SC to enhance student mental health and promote a healthy digital environment. These results offer valuable insights for educators, health professionals, and policymakers in Ethiopia and other developing countries facing similar challenges. Full article

Understanding the influence of heat transfer on the pyrolysis process is crucial for optimizing industrial biofuel production processes. While numerous scientific studies focus on experimental investigations of pyrolysis using laboratory-scale devices, many neglect the essential role of thermal energy in initiating and controlling thermal decomposition processes. This study presents a transient two-dimensional numerical model of biomass single-particle pyrolysis, which includes the energy balance, mass conservation equations and pyrolysis gas pressure and velocity equations. The model employs explicit numerical methods to manage the high computational demands of 2D transient simulations, but is successfully validated with the use of experimental data found in the literature. The model reflects the heterogeneous structure of wood by using different thermal conductivity coefficients depending on the wooden fibers’ orientation. The results demonstrate the impact of fiber orientation on the heat transfer and thermal decomposition processes. The anisotropic properties of wood led to varied temperature fields and pyrolysis decomposition stages, aligning well with experimental data, thus validating the model’s accuracy. The proposed approach can provide a better understanding and lead to improvement in biofuel production processes, enabling more efficient and controlled conversion of biomass into fuel. By optimizing the pyrolysis process, it contributes to the development of sustainable energy preservation and regeneration methods, supporting a shift towards more sustainable fuel production patterns using renewable biomass resources like wood. Full article

In recent years, sustainable entrepreneurship has emerged as a dynamic field, driving innovative solutions to environmental, social, and financial issues, as evidenced by the improvement of income systems. The purpose of this study is to explore the impact of the forward-looking strategy on enterprise performance so as to ensure that enterprises can maintain the ability of sustainable development. Foresight can promote the enhancement of sustainable development. Therefore, the current research mainly determines that forward-looking strategies will ultimately affect the performance of enterprises through the impact on their own dynamic capabilities. Through the empirical investigation of 125 enterprises, the corresponding research data are obtained. The results show that the forward-looking strategy has a positive impact on enterprise performance, while enterprise dynamic capability, as an intermediary variable, has a positive impact between the forward-looking strategy and enterprise performance. This research introduces market dynamic capability as a moderating variable to explore whether forward-looking strategies can adapt to changes in the external market environment. Structural equation modeling (SEM) is used to examine the complex relationships between multiple independent and dependent variables of forward-looking strategies and dynamic capabilities, including the impact of latent variables. Under the background of digital economy, digital technology gradually infiltrates the operation of enterprises and plays a vital role in enterprise performance. Digital transformation has become a realistic need for enterprises to respond to changes in the market environment and seek development. The forward-looking strategy has brought new opportunities to solve this problem. The core of the forward-looking strategy lies in “forward thinking” and “pioneering intention”. It not only emphasizes the ability to predict and identify potential opportunity windows in uncertain environments but also pays attention to the cultivation of enterprise resilience and openness to maintaining sustainable competitive advantage. Its foresight can build dynamic capabilities and ensure the sustainable development ability of enterprises through continuous insight into market information and technology resources, such as opportunity recognition perception, knowledge absorption and transformation, resource replacement and innovation, organizational change, and reconstruction. Full article

This study investigates the impact and mechanisms of achievement goal orientation on online learning engagement among undergraduates, using a sample of 461 students enrolled in online courses from four universities of varying levels in Shanghai, China. Self-efficacy is introduced as a mediating variable, and structural equation modeling is employed to assess the effects. The findings reveal that different types of achievement goals have varying natures and intensities in their associations with undergraduate online learning engagement. Self-efficacy partially mediates the effect of mastery-approach goals on online learning engagement, but does not mediate the effects of mastery-avoidance, performance-approach, or performance-avoidance goals. The study recommends leveraging the guiding role of mastery-approach achievement goals to help students set scientific and reasonable goals, and stimulating students’ self-efficacy through the dual influences of external support and internal motivation. With the support of these strategies, significant improvements in undergraduate online learning engagement can be achieved. Full article

In order to examine the relationship between cyber-ostracism and social anxiety among undergraduates, as well as to investigate the mechanisms underlying the effects of cyber-ostracism, rejection sensitivity, and rumination on social anxiety, this study recruited 864 undergraduate students from Jiangsu and Guangdong Provinces in China using a cluster sampling method. The participants completed the Cyber-Ostracism Questionnaire, the Chinese version of the Interaction Anxiousness Scale, the Chinese version of the Rejection Sensitivity Questionnaire, and the Chinese version of the Ruminative Responses Scale. Furthermore, the mediating effects were examined using the structural equation modeling (SEM) method. The results showed that (1) cyber-ostracism was positively related to social anxiety among undergraduates, and (2) rejection sensitivity and rumination played a chain mediating role in the relationship between cyber-ostracism and social anxiety. Full article

A numerical hydrodynamic model for a moored interconnected floating large structure under the action of regular waves is presented to analyze the effect of current and wind. The floating structure consists of 20 hinged plates that are linked together and secured with mooring lines along its edges. A brief discussion is provided on the multi-body hydrodynamics equations related to the numerical model definitions in both the frequency and time domains. Conversely, a concise overview of the experiment is given. The numerical model outcomes of vertical displacements and wave quantities are compared against the results obtained from model test data sets and numerical and analytical models in a recent publication. A high degree of accuracy has been noted in reflection and transmission coefficients with a certain value of current velocity. The numerical model simulating interconnected structures of 10 and 16 hinged plates is analyzed, and the resulting vertical displacements under the influence of current are compared to those of a 20-hinged structure. The impact of currents and winds on the hydrodynamic response of the structure is examined by studying various results, using stiffness values for both mooring and hinges. Further, the effect of wavelengths on the wave transmission on every side of the interconnected structure through contour diagrams, hydrodynamic diffraction for different incident angles, and wave quantities on current speed are analyzed. It is observed that as the current speed rises, the structural displacement also escalates; meanwhile, no impact of the wind on the floating interconnected structure is noted. It has been observed that as the wave direction shifts from 0° to 60°, the interconnected floating structure experiences a slight reduction in wave motion throughout the entire system. Full article

Critical listening, critical reading, and critical thinking are three closely related cognitive skills that aim to evaluate information with an analytical and questioning approach. Critical listening and critical reading, which are receptive language skills, represent the application of critical thinking in different contexts. Critical thinking, which is a productive language skill, provides a framework for these two receptive language skills and enables the evaluation of the accuracy of information accessed through critical listening and critical reading, analyzing different perspectives and making inferences to reach correct conclusions. These two skills support the development of critical thinking skills and contribute to individuals gaining deeper understanding based on the perspective of knowledge. This study aims to determine the relationships between critical listening, critical reading, and critical thinking, the effects of these variables on each other, and the explanation ratios. The study group of this study was determined through simple random sampling, one of the random sampling methods. The participants consisted of 201 teacher candidates studying in the Department of Turkish Language Teaching at a university in the north of Türkiye. The Critical Listening Scale, Critical Thinking Attitude Scale, Critical Reading Self-Efficacy Perception Scale, and a personal information form were used to collect research data. The data collected in the research were analyzed using structural equation modeling via AMOS 22.0. As a result of the research, it was determined that all hypothesis models established based on the relevant literature were valid. Two of the three hypotheses regarding the theoretical model were supported by the data, and one hypothesis was rejected. Critical listening has a direct high level effect on critical thinking and predicts it at a significant level. Critical listening has a direct high-level effect on critical reading and predicts it at a significant level, while explaining 65% of the total variance related to critical reading. The effect of critical reading on critical thinking is insignificant and does not predict critical thinking at a significant level. In the theoretical model created the effect of critical reading on critical thinking is insignificant, but these two variables explain 85% of the variance related to critical thinking. As a result of the research, it can be said that the main predictor of critical thinking is critical listening, and that critical reading and critical thinking develop depending on the development of critical listening. Full article

In the Spring of 2020, Coronavirus 2019 (COVID-19) was officially declared a global pandemic, which prompted an unprecedented number of changes to societal functioning. Amongst those who experienced significant life alterations were collegiate athletes within the United States (US). The purpose of this study was to examine the relationship between US athletes’ perceptions of their team motivational climate, perceived support from coaches and teammates, and their optimistic thoughts during the COVID-19 pandemic. US collegiate athletes (N = 756; 56.3% female; Mage = 20.07 years, SDage = 1.57 years) across a variety of levels (e.g., Division I) and sports (e.g., basketball) were invited to participate in this study. Structural equation modeling analyses revealed significant positive associations between a caring and task-involving climate, athletes’ feeling supported by their coaches and teammates, and athletes’ optimistic thoughts during the COVID-19 pandemic. In addition, an ego-involving climate was significantly negatively associated with athletes’ feeling supported by their coaches and teammates. The final results suggest that the supportive actions of coaches and teammates during difficult times can mediate the positive connection between perceptions of a caring-task-involving climate on athletic teams and an athlete’s ability to stay optimistic during difficult life stressors. Full article

With the deep integration and development of both the digital economy and the ecological economy, governments, media, researchers and others have begun paying great attention to green digital issues. Yet whether and how digital resources shape corporate social responsibility (CSR) remains unclear. This paper examines the relationship between digital resources, CSR, and environmental performance during a period of rapid technological development, with a focus on Chinese manufacturing enterprises. We draw on structural equation modeling (SEM) to verify how digitalization contributes to more environmentally friendly and sustainable economic development. Our dataset comprises survey data from 174 Chinese manufacturing companies, providing a theoretical basis and empirical support for the deep integration of digitalization with green and low-carbon transformation. The results demonstrate that digital resources significantly promote CSR, which in turn facilitates the improvement of environmental performance. We thus find that CSR plays a mediating role in the digital resources–environmental performance relationship. Consequently, companies can consider greening their innovations through CSR practices as part of the digital transformation environment. Finally, digital resources and CSR contribute to greening innovation in different ways. This study highlights the critical role of robust CSR in driving green performance during digital transformation. It addresses a significant research gap by exploring the synergistic relationship between digitalization and green innovation, emphasizing the strategic importance of integrating CSR to achieve mutually beneficial outcomes for both society and businesses. Additionally, the study identifies deficiencies in existing research regarding the interplay between digital transformation and CSR and investigates how enterprises can directly enhance environmental performance by leveraging digital resources within the context of the digital economy. Full article

Studies have shown that the school atmosphere perceived by students can play a key role in promoting their well-being and success in school. No study to date has analyzed whether the students’ perceived school atmosphere might contribute to school refusal (SR), which in turn might reduce students’ engagement and promote underachievement. A cross-sectional study was conducted with 528 Italian high school students (M_age = 16.08, SD = 1.38; 50.8% males, 47% females, and 2.3% not declared), with the aim of assessing the role of the mediation of SR (Anxious Anticipation, Difficult Transition, Interpersonal Discomfort, and School Avoidance) in the association between students’ perceived school atmosphere (Student Relations, Student–Teacher Relations, Educational Climate, Sense of Belonging, and Interpersonal Justice) and school engagement and underachievement. Data were collected using validated instruments, including the SChool REfusal EvaluatioN for school refusal, the Multidimensional School Climate Questionnaire for school atmosphere, and the Utrecht Work Engagement Scale for school engagement. To evaluate the association between variables, we performed structural equation modeling with latent variables. Mediation analysis indicated that Difficult Transition fully mediates the association between Sense of Belonging and school engagement (β = 0.20, p ≤ 0.05). This study extends the knowledge of school refusal behavior. Full article

To reasonably divide the types of flow units along the latticework subchannel, one must prepare for the establishment of a one-dimensional fluid network model of the latticework in the middle region of the turbine blade. The characteristics of the flow structure along the latticework subchannel were studied by numerical simulation. The effects of rib angle (15–45°), the ratio of rib width to rib spacing (0.3–1.0), and inlet Reynolds umber (21,000–80,000) on the flow structure along the subchannel are summarized. The results indicated that the ratio of rib width to rib spacing and inlet Reynolds number had no effect on the distribution position of each flow unit in the subchannel. The change of rib angle did not change the flow structure type along the subchannel. The longitudinal vortex was mainly formed by one turning vortex and two detached vortices. The narrowing of the turning channel will cause the turning vortex to induce a secondary longitudinal vortex. There were five kinds of flow structures along the subchannel: transverse vortex zone (entrance of the inlet section), uniform flow zone (inlet section), longitudinal vortex generation zone (turning channel section), longitudinal vortex zone (turning channel section), and longitudinal vortex free development zone (outlet section). This finding provides support for the selection of empirical formulas for each module in the one-dimensional modeling of subchannels. Finally, the boundary prediction equations of each flow structure in the subchannel were established, and the average prediction error was less than 10%. The rationality of the flow structure division along the latticework subchannel was improved, and the modeling efficiency of the latticework one-dimensional model was optimized. Full article