Search Results (378)

Solid propellant grain, as a typical polymer, are the thrust generation devices and core load-bearing components of solid rocket motor (SRM) and are also known as SRM grain. They are constantly exposed to extreme service environments such as high temperatures, high pressures, and dynamic shocks, and have a relatively high failure rate in the field use of SRM. Its life and reliability are the shortcomings that restrict the improvement of weapons and equipment capability in China at present. This paper summarizes the typical fault types of SRM grain at present, and compares and analyzes the research progress of reliability design and analysis technology, reliability optimization technology, life test technology and reliability evaluation technology of SRM grain at home and abroad; This paper analyzes the deficiencies and reasons in the research and application of SRM grain reliability technology in China, and points out the technical difficulties and challenges faced by the integrated design of performance and reliability of SRM independent innovation design according to the needs of the forward research and development system of SRM. Based on the existing design level and industrial foundation in China, the basic research suggestions that should be carried out to consolidate the design ability of SRM grain in China are given. Full article

Background: The longitudinal RisCoin study investigated risk factors for COVID-19 vaccination failure among healthcare workers (HCWs) and patients with inflammatory bowel disease (IBD) at a University Hospital in Germany. Since the hospital served as the study sponsor and employer of the HCW, we implemented a custom mobile application. We aimed to evaluate the implementation, adherence, benefits, and limitations of this study’s app. Methods: The app allowed secure data collection through questionnaires, disseminated serological results, and managed bidirectional communication. Access was double-pseudonymized and irreversibly anonymized six months after enrollment. Download frequency, login events, and questionnaire submissions between October 2021 and December 2022 were analyzed. Multivariable logistic regression identified factors associated with app adherence. Results: Of the 3979 participants with app access, 3622 (91%) used the app; out of these, 1016 (28%) were “adherent users” (≥12 submitted questionnaires). App adherence significantly increased with age. Among HCW, adherent users were more likely to be non-smokers (p < 0.001), working as administrators or nursing staff vs. physicians (p < 0.001), vaccinated against influenza (p < 0.001), and had not travelled abroad in the past year (p < 0.001). IBD patients exposed to SARS-CoV-2 (p = 0.0133) and those with adverse events following the second COVID-19 vaccination (p = 0.0171) were more likely adherent app users. Despite technical issues causing dropout or non-adherence, the app served as a secure solution for cohort management and longitudinal data collection. Discussion: App-based cohort management enabled continuous data acquisition and individualized care while providing flexibility and anonymity for the study team and participants. App usability, technical issues, and cohort characteristics need to be thoroughly considered prior to implementation to optimize usage and adherence in clinical research. Full article

Background/Objectives: Sports tourism, particularly international running events such as half marathons and marathons, has rapidly grown due to rising health consciousness and active lifestyles. Runners competing abroad face unique nutritional challenges that extend beyond physiological needs, including adaptation to local food cultures and psychosocial factors. This study aims to explore the nutritional difficulties encountered by international runners during competitions abroad, using participants of the Poznan Half Marathon 2025 as a case example. Methods: A qualitative research design was employed, involving semi-structured in-depth interviews with 12 international runners from the United Kingdom, Germany, and Ukraine. Participants had at least two years of experience competing internationally. Results: Four primary categories of nutritional challenges emerged: (1) quality and availability of food, (2) adaptation to local eating habits and physiological impacts, (3) hydration and access to appropriate fluids, and (4) logistical factors and the interactions between psychological stress, physical well-being, and nutritional choices. These factors influenced runners’ preparation, race-day performance, and recovery, highlighting the complexity of managing nutrition in unfamiliar environments. Conclusions: Nutritional challenges for international runners are multidimensional, requiring flexible and culturally sensitive nutritional strategies. Although these findings offer useful insights, they are based on a small, specific sample and should be generalized with caution. Further research is necessary to explore the broader applicability of the findings and their relevance to diverse athletic populations and contexts. Full article

This research aims to investigate the Italian architectural heritage in Brazil through the analysis of the ‘Santa Casa de Misericórdia’ hospital in São Carlos, in the state of São Paulo. As part of the KNOW.IT national project, the work aims to recover and digitally enhance Italian heritage abroad from the 19th and 20th centuries. The buildings analysed were either designed or built by Italian architects who emigrated to South America or constructed using materials and techniques typical of Italian architecture of those years. The hospital, designed by the Italian architect Samuele Malfatti in 1891, was chosen for its historical value and its role in the urban context of the city of São Carlos, which, moreover, continues to perform its function even today. The study aims to create a digital archive with 3D models and two-dimensional graphical drawings. The methodology includes historical analysis, photogrammetric survey, and digital modelling using Agisoft Metashape and 3DF Zephyr software. A total of 636 images were processed, with the maximum resolution achieved in the models being 3526 × 2097 pixels. The results highlight the influence of Italian architecture on late 19th-century São Carlos and promote its virtual accessibility and wide-ranging knowledge. Full article

With the increasing prominence of the energy crisis and environmental problems, microgrid technology has received widespread attention as an important technical means to improve the stability and reliability of new energy access. Focusing on the latest development of microgrid operation control technology, this paper combs and summarizes the related research at home and abroad, including the key technologies of microgrid optimization operation, power prediction and virtual synchronous active support control technology, and points out their advantages and limitations. First, this review describes the concept and structure of microgrids, including components such as distributed power sources, energy storage devices, energy conversion devices and loads. Then, the microgrid optimization operation technologies are analyzed in detail, including energy management optimization algorithms for efficient use of energy and cost reduction. Focusing on microgrid power forecasting techniques, including wind energy and PV power forecasting and load forecasting, the contributions and impacts of different power forecasting methods are summarized. Furthermore, the inverter control strategies and the stability mechanism of the virtual synchronous generator (VSG) active support control technology are investigated. Finally, synthesizing domestic and international microgrid development experience, this review summarizes the current state-of-the-art technologies, analyzes the advantages and limitations of these key technologies (including optimization scheduling, power prediction and VSG-based active support control) and highlights the necessity of their continuous improvement to provide a solid foundation for promoting the widespread application and sustainable development of microgrid technology. Full article

Return migration is frequently associated with failure, particularly in the context of women returnees from the global south. This research challenges this notion, focusing on women returnees from Italy to North Africa. It aims to analyze return migration by focusing on women who returned to Morocco and Tunisia in the last 15 years, and the aftermath of the Arab uprisings, emphasizing the transformative potential of migration experiences for themselves and the local community. Women returnees not only redefine their roles in society but also foster socio-economic development, community building, and political changes in the countries of return. The study employs thematic analysis to examine 25 semi-structured interviews conducted with returnees aged 25–60, where women shared insights into their migration, re-adaptation experiences, and challenges upon return. Returnees utilized skills gained abroad to achieve economic empowerment, often starting businesses or finding new jobs. However, they faced cultural challenges, particularly societal expectations of traditional gender roles. Nonetheless, migration empowered many returnees to question these policies and norms, and contribute to societal change. Full article

This qualitative study investigates how short-term international mobility—specifically Erasmus staff exchange—nurtures educational leadership in an increasingly globalized landscape. Drawing on in-depth interviews with 55 educators from European and non-European countries, the research traces the ways mobility experiences reshape professional practice, career trajectories and institutional engagement. Findings show that time abroad enhances intercultural competence, global awareness, and pedagogical innovation—capabilities central to educators who must lead learning in diverse, rapidly evolving contexts. Participants described a renewed sense of purpose and an expanded leadership identity on reentry, positioning mobility as both a personal and systemic catalyst. Nonetheless, persistent barriers—including financial constraints, language proficiency gaps, and uneven institutional support—continue to restrict mobility access. Addressing these inequities is imperative if Erasmus and similar programs are to serve as genuine engines of educational transformation rather than isolated opportunities for the already advantaged. By mapping the link between mobility, leadership growth, and institutional change, this article offers actionable insights for policy-makers and university leaders seeking to embed inclusive, innovation-oriented practices across local and international education systems. Full article

Ecological restoration and brownfield reuse are important issues in the current field of urban sustainable development and environmental protection. This paper adopts bibliometric and network analysis methods, using more than 600 literature from Web of Science (WOS) and China National Knowledge Infrastructure (CNKI) databases as research objects, to analyze the research trends, main researchers, contributions of different disciplines, and research hotspots in ecological restoration and brownfield reuse. Based on the results of quantitative analysis, this paper reviews the main research theories, methods, and technologies of ecological restoration and brownfield reuse at home and abroad, as well as response strategies in different regions and future prospects under challenges. Among the top 10 disciplines in terms of disciplinary contribution, the discipline with the highest relevance in the research articles of CNKI is “Environmental Science and Technology”, accounting for approximately 47.24%. The discipline with the highest relevance in the research articles of WOS is “Building Science and Engineering”, accounting for approximately 61.21%. In terms of research theories and methods, emphasis is placed on the application of ecological engineering, landscape ecology, land economics, and sustainable development methods. At the same time, adaptive management methods are emphasized, aiming to achieve a balance between ecological protection and urban development. In terms of response strategies for different regions, the main strategies for ecological restoration and brownfield reuse are proposed from five main aspects: reducing soil erosion and controlling water pollution, restoring ecological communities and enhancing biodiversity, landscape reshaping and spatial transformation, tourism development, and leisure space design. Based on the current challenges in technology, law, funding, management, and society, research prospects for strengthening interdisciplinary integration, digital drive, interdisciplinary collaboration, and multi-party cooperation in the future are proposed. It can be seen that research in this field is no longer just a simple ecological issue, but a comprehensive social problem. Full article

Over the past 20 years, researchers have shown increasing interest in social network analysis to understand second language acquisition (SLA), especially in a study abroad (SA) context. To date, few longitudinal studies have examined the joint evolution of the learners’ sociolinguistic competence and socialisation during the SA. By shifting the focus from a global view of the study abroad context to a deep analysis of the composition and structure of each learner’ social networks in the host country, we aim to provide a better understanding of the development of sociolinguistic competence in SLA (Gautier & Chevrot, 2015). We apply the sociological concept of a social network to sociolinguistics. To explore the sociolinguistic competence of 29 learners, we focus on two well-described sociolinguistic variables in French: the optional liaison and the negative ne. We also gathered data on their social networks and provided a deep analysis of each participant’s network. We implemented a quantitative approach to analyse and depict the social networks of the learners. Statistically significant relationships were found between changes in the learners’ personal network and their use of the two sociolinguistic variables. The development of L2-oriented social networks (in terms of size, speaking time, and frequency) over nine months of the SA helps learners to reduce their use of standard variants. Conversely, the development of L1-oriented social networks during the SA is associated with greater use of standard variants. Full article

This study examines the role of Christian missionary interpreters from the Open Port Period to the Japanese colonial era, highlighting their historical significance and influence. During the Open Port Period, missionaries relied on Korean language teachers to serve as interpreters, translators, evangelists, and preachers. Although their English proficiency was often limited, they played a crucial role in early Christian missions. In the Japanese colonial era, elite intellectuals who had studied abroad increasingly assumed interpretation roles, actively contributing to theological education and social reform. This study analyzes historical records, newspaper articles, and existing research to reconstruct the evolving role and broader impact of Christian interpreters. The findings suggest that missionary interpreters were not merely linguistic mediators but key figures in evangelism and social transformation. Furthermore, the study highlights the historical transition from consecutive interpretation to simultaneous interpretation in Korean churches and underscores the need for systematic training programs. Given the growing linguistic diversity in Korean congregations, churches must recognize the importance of trained interpreters in ensuring effective multilingual worship and uphold the legacy of missionary interpretation. Full article

In recent years, domestic research on the ion substitution behavior and chromaticity of the mineral composition of “Ya’an Green” remains insufficient, while there is almost no relevant research on “Ya’an Green” abroad. In this study, X-ray powder diffraction (XRD), electron probe microanalysis (EPMA), infrared spectroscopy (IR), ultraviolet–visible spectroscopy (UV-Vis), and colorimetry were employed. The results indicate that the green and yellow matrices of “Ya’an Green” are primarily composed of muscovite, with rutile also present in the yellow matrix. In contrast, the white–green samples are mainly composed of quartz, with muscovite as a secondary mineral. Additionally, it was observed that the (004) crystal plane of muscovite exhibits a peak shift to lower 2θ angles, attributed to the substitution of Al³⁺ by ions with larger radii, such as Ba²⁺, Cr³⁺, and Fe²⁺, leading to an increase in unit cell parameters and a consequent shift in the peak to lower wavenumbers. The main elements of “Ya’an Green” are Al, Si, and K, with minor elements including Na, Fe, and Cr. Furthermore, Mg²⁺, Ca²⁺, Ti⁴⁺, Cr³⁺, and Fe²⁺ in the samples can substitute for Al³⁺ through isomorphic substitution. The infrared spectrum of muscovite in the ‘Ya’an Green’ sample shows three typical absorption peaks, 422 cm⁻¹ and 513 cm⁻¹ caused by Si-O bending vibration, 697 cm⁻¹ and 837 cm⁻¹ caused by Si-O-Al vibration, 948 cm⁻¹ caused by O-H bending vibration, and 3647 cm⁻¹ caused by O-H stretching vibration. The peak at 837 cm⁻¹ exhibits varying degrees of shift due to the substitution of Al³⁺ by ions with larger radii. The ultraviolet–visible spectra display two broad absorption bands at 422 nm and 615 nm, which are caused by Cr³⁺ transition, indicating that Cr is the chromogenic element responsible for the green color. A correlation was observed between the Cr³⁺ content and the hue angle h in “Ya’an Green” samples: the higher the Cr³⁺ content, the closer the hue angle is to 136^°, resulting in a darker green color, while lower Cr³⁺ content leads to a deviation from the dark green hue. This study establishes for the first time the correlation between the mineral composition of ‘Ya’an Green’ and its chromatic parameters and explores the linear relationship between its color and the number of color-causing elements and elemental substitution, which provide data support and theoretical models for the study of the color of seal stones. Full article

Studying abroad has been emphasised to increase the cultural influence of sending countries and promote international understanding. This study re-examines study abroad as part of the internationalisation of higher education, using concepts of soft power, knowledge diplomacy, public diplomacy, and cultural diplomacy. Specifically, the study highlights the limitations of the conceptual frameworks of ‘nation’ and ‘formal educational opportunities’ in studying abroad, and discusses a perspective on learning that goes beyond the physical space of the university and the formal educational opportunity. Furthermore, this study considers cultural studies and a public pedagogy perspective to examine where and how studying abroad and international learning can occur. Therefore, this research aims to provide a more interdisciplinary perspective on higher education research surrounding the phenomenon of studying abroad, and to examine the academic boundaries that define the field of research on the internationalisation of higher education. The paper concludes that studying abroad and international education should be reconsidered as a ‘medium’ that promotes cross-border learning by understanding culture and social structure. Full article

Due to the promotion of sustainable development goals and rapid economic development, the problem of rural sewage treatment is becoming increasingly severe. In order to understand the research hotspots, progress, and trends of ecological treatment technology for rural sewage at home and abroad, this article analyzes relevant literature published between 2000 and 2023 based on the core collection databases of China National Knowledge Infrastructure (CNKI) and Web of Science (WOS) using VOSviewer and CiteSpace visualization software. The research results indicate a continuous increase in attention to ecological treatment technologies for rural sewage, both domestically and internationally. Although China started relatively late in this field, it has developed rapidly. “China Water & Wastewater” has had a significant impact in related fields domestically, and a top-tier journal has not yet been founded by China internationally. The collaboration between research authors and institutions is evident, with CNKI focusing on exploring specific governance technologies, while WOS pays more attention to the overall governance framework and critical technologies. The research hotspots of ecological treatment technology for future village and town sewage include specific treatment technologies, treatment efficiency, overall treatment strategies, and environmental impact assessments. At the same time, cross-regional and cross-border cooperation should be strengthened, interdisciplinary collaboration should be promoted, open cooperation platforms should be established, diversified publishing channels should be supported, and research on microbial communities and non-point source pollution should be deepened. Full article

With the rapid development of China’s economic construction and the increasing scale of the project, more and more complex engineering geological problems have put forward higher requirements for engineering geological researchers. As the core link of engineering geological research, engineering geological evaluation provides a key scientific basis for solving engineering geological problems. The engineering geological evaluation model is a good tool and means to support the realization of the evaluation method. Therefore, it is urgent to study three-dimensional engineering geological evaluation modeling systematically. In view of the current situation that the construction methods of the three-dimensional engineering geological evaluation model in the field of infrastructure construction at home and abroad are not uniform, this paper briefly summarizes the research progress of the three-dimensional engineering geological evaluation model. It focuses on three-dimensional geological modeling and the three-dimensional engineering geological space evaluation index system. This study discusses the main methods for comprehensive engineering geological evaluation and the construction of a three-dimensional geological model. At the same time, in response to the low accuracy of current three-dimensional engineering geological evaluation models and their insufficient integration with numerical simulations, this paper proposes improvement suggestions and outlines the development trends of such models. The purpose of this paper is to deepen the engineering geological evaluation work, promote its sustainable development, and lay the foundation for the study of a three-dimensional engineering geological evaluation model so as to cope with more complex engineering geological challenges in the future. Full article

In the context of intensifying climate and environmental changes, the high resilience of irrigation district infrastructure is of crucial importance for sustainable agriculture and water security. This paper proposes a resilience assessment indicator system for irrigation district infrastructure, comprising 23 indicators from the four dimensions of foresight capacity, absorption capacity, restoration capacity, and adaptive and learning capacity. This system is constructed by combining the research status quo at home and abroad with the change process of the resilience function. The model was constructed using the DEMATEL-ANP-Cloud method, and the Zhaokou Irrigation District in China was used as a case study to demonstrate the model’s application. The resilience analysis was conducted, and targeted strategies for enhancing resilience were proposed. The resilience assessment model constructed in this study provides a scientific basis for the resilience assessment of irrigation district infrastructure and a reference point for similar projects in terms of risk reduction and system resilience improvement. This is of great significance for guaranteeing sustainable agriculture and water security. Full article