Government of France

The Callovo-Oxfordian (COx) claystone is investigated as host rock in the French project Cigeo for geological disposal of radioactive waste. Temperature rise due to heat emitted by radioactive waste is an important process to be considered. It is crucial to characterize effects of temperature change on the mechanical behavior of host rock. Despite previous studies, the issue is still open. This work presents a complementary study by performing a new series of triaxial compression tests. Six different values of temperature are considered ranging from 20 degrees C to 90 degrees C. The tests are performed under three different confining pressures. Elastic properties upon unloading-reloading paths and peak deviatoric stresses are evaluated for each test. It is found that the peak deviatoric stress of COx claystone is more affected by the temperature rise than the elastic properties. Scatters of experimental data are also investigated by comparing several tests performed under the same loading conditions. Finally, the thermal effects on the failure strength are evaluated by using a micromechanics-based criterion.

The quality of teachers’ instructional practices is a core indicator of effective teaching and a direct driver of student achievement, so identifying what helps teachers adapt and improve instructional practices is essential. In this study, relationship between school leadership and teachers’ instructional practices was investigated by examining the mediating role of collective teacher culture and the moderating role of trust in school leader within the framework of Social Exchange Theory. We tested our hypotheses using data from 79 schools (≥ 10 teachers each); results showed that school leadership had an impact on instructional practices through collective teacher culture. However, direct impact of school leadership was not significant. We also found that trust in school leader has a moderating role in the indirect effect of school leadership on instructional practices, that is, as trust in school leader increases, this indirect effect also increases. We offer theoretical guidance and practical implications for improving teaching quality. School leadership positively influences teacher instructional practices through collective teacher culture as a mediating mechanism. Trust in school leaders significantly moderates both the leadership- Collective culture relationship and the indirect effects on instructional practices. Collective teacher culture emerges as a critical pathway through which leadership improvements translate into classroom-level instructional quality.

Video gaming is a widespread practice among young adults, and it is becoming increasingly social. Analog games are affected by this trend as well; social platforms like Reddit host many communities about these playing practices. However, while the impact of online digital gaming on players’ mental health is well explored, this relationship has been overlooked in the context of analog play. This article addresses this gap by validating through a Rasch analysis the Internet Gaming Disorder Scale-Short Form (IGDS9-SF) with N = 481 analog gamers from related communities on Reddit. In addition, simple mediation analyses were performed to examine the role of gamer identification as a mediator on the relationship between gaming community attractiveness and problematic gaming behaviors in analog play. The results show that IGDS9-SF is a robust instrument to shed light on problematic analog gaming, while gamer identification partially mediates the relationship between problematic gaming symptoms and community attractiveness.

This study examines the impact of combining Realistic Mathematics Education (RME) with creative learning methodologies—specifically, student-created short films—on secondary school students’ mathematics achievement, attitudes, and self-efficacy. The participants consisted of 52 sixth-grade students from a public middle school located in a socioeconomically disadvantaged region of southern Türkiye, comprising refugee, immigrant, and internally migrated families. The study employed a quasi-experimental pretest–posttest control group design over a four-month intervention period. Students in the experimental group collaboratively developed real-life mathematical scenarios and transformed them into three short films, while the control group received traditional instruction. Data were analyzed using t-tests. The findings revealed statistically significant improvements in the experimental group across all three variables. Moreover, large effect sizes were observed (e.g., d = 1.19 for mathematics achievement, d = 2.61 for attitudes), indicating a strong educational impact. These results suggest that integrating RME with student-driven multimedia production can be a powerful pedagogical strategy, particularly for disadvantaged and culturally diverse student populations. The study recommends broader implementation of this approach to promote mathematical engagement and equity in education.

This study aimed to investigate the effect of number talks on the number sense of fourth-grade primary school students using a mixed-method design, with particular attention to students with varying levels of initial number sense and perceptions from teachers and students. A quasi-experimental design with a pretest-posttest control group was employed in this research. Additionally, both quantitative and qualitative research methods were utilized. The “Fourth-Grade Number Sense Test” was employed to collect quantitative data, while “Interview Forms” were used to gather qualitative data. The study sample comprised 219 fourth-grade students from three primary schools. Before the experimental process, all participants were administered the “Number Sense Scale for 4th Graders” as a pretest, which was subsequently re-administered as a posttest upon completion of the intervention. Data analysis was conducted using t-tests for both dependent and independent samples. To complement the quantitative data, in-depth interviews were conducted with teachers from the experimental group and twenty-two students from the experimental group. The qualitative data obtained were analyzed using descriptive and content analysis techniques. The findings revealed a significant difference in number sense between students in the experimental group, where number talks were implemented, and those in the control group, where they were not, based on pretest and posttest measurements. Moreover, while number talks had no significant impact on students with a high level of number sense, they were found to be effective in improving the number sense of students with lower initial levels. These findings suggest that number talks are an effective and inclusive strategy to enhance number sense development, particularly for lower-performing students, and should be integrated into mathematics instruction and teacher training. Additionally, both teachers and students perceived number talks as distinctive, engaging, instructive, stimulating, and enjoyable.