Search

In recent decades, informal project-based learning (PjBL) for science, technology, engineering, and mathematics (STEM) education has gained immense significance. Though some meta-analytical studies have reported the effectiveness of PjBL models, none of them has been explicit for informal PjBL models executed for school students in STEM education. Therefore, this meta-analytical study sought to investigate the effect of the informal PjBL model on students' learning gains when compared to the traditional classroom setting. The study also intends to explore the effect of potential moderator variables that might impact the effectiveness of the model. For this, a systematic review aligning to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) methodology has been employed, by incorporating 26 peer-reviewed empirical studies, encompassing data from 3202 students from eight countries. The meta-analytical results revealed overall moderate effectiveness (d = 0.248, p < 0.001), indicating that informal PjBL has moderately significant effects on students' gains when compared to the traditional classroom setting. Correspondingly the moderator analysis revealed that the overall effectiveness of informal PjBL was influenced by the teaching model, assessment method, students' group size, and course duration. However, the participants' educational level and study location (country) did not emerge as being significant. This study contributes to the bulk of literature that can help academicians to design, develop and implement effective STEM-based informal PjBL models, with special consideration for influential variables (teaching method, assessment method, grade, location, course duration, group size, and subject area).

High school research experience programs (HSREPs) provide opportunities for true science education and expose students to scientific investigations in laboratory settings. Various HSREPs models have been practiced to shape students' research understandings; however, a systematic comparison of the success, challenges, and opportunities of these HSREPs has not been gauged. This article compares the effectiveness of such science, technology, engineering, and mathematics (STEM) based HSREP models reported in the last two decades. We shortlisted seventeen studies on the most effective HSREPs and identified the characteristics of these reports. Results show that student research experiences vary depending on the structure of the model used and the nature of the laboratory setting to which students are exposed. However, there is a dire need to integrate more collaborative and customized research practices to accommodate more students in HSREPs. Additionally, intensive support, mentoring, and coaching are essential to provide students a comprehensive understanding to excel in their research career pathway. Finally, there is a desperate need for further studies to develop the frameworks that can help the smooth transition of high school students into research-oriented university programs.

The current study provides an insight into the thermal stability of perovskite solar cells (PSCs) and the factors causing their degradation. To this end, a systematic stability study was carried out on n-i-p type perovskite solar cells involving mesoporous TiO2 layer. The samples were subjected to varying moisture and thermal conditions under light soaking while being exposed to long-term indoor (5000 h) and outdoor (75 h) harsh environmental conditions (i.e. 30%-80% RH and 40 °C-70 °C). To identify performance and morphological changes of PSCs after exposure to thermal stress, advanced characterization techniques including impedance spectroscopy, scanning electron microscopy and glow discharge optical emission spectrometry along with I-V characteristics were used. The un-encapsulated samples exposed to high thermal stress (40-70 °C) show degradation in their efficiency more than 40% within the 75 h of thermal stress. In contrast, the samples that were kept at room temperature were found to be very stable over 5000 h. [ABSTRACT FROM AUTHOR]

This research work presents a simple and effective way for preparation of polyaniline (PANI) nanofiber composites mixed with polyvinyl alcohol or polystyrene (PS) and their application for lead (Pb) removal from an aqueous medium. Interestingly, PANI/PS porous nanofibers show excellent performance as a one-step Pb removal technique from aqueous solutions. The efficiency of Pb removal is found to be more than 95%, which is pretty higher than the previously reported values of other nanocomposites, as Pb removal adsorbents. Furthermore, when pure PANI nanofibers cannot remove Pb in an efficient way, this is a straightforward method for separation from the solution. This is attributable to the high surface area of PANI-PS composites. This study also provides a simple and effective way for the development of new environmental cleaning materials. The PANI/PS composite nanofiber could be a good candidate for efficient Pb removal from wastewater and for deep purification of polluted water. The composite materials have been investigated in terms of morphology, chemical structure, thermal behavior, and defect evolution using Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, Differential Scanning Calorimetry, Thermal Gravimetric Analysis, and Positron Annihilation Spectroscopy, respectively. To measure the adsorption capacity and intensity of adsorption, the adsorption data were fitted in Langmuir, and Freundlich models. J. VINYL ADDIT. TECHNOL., 23:E99-E106, 2017. © 2016 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Research-based learning models, particularly interdisciplinary programs, are crucial in promoting STEM skills and fostering positive attitudes among students. This study presents a meta-analysis evaluating the impact of a chemistry-based interdisciplinary research experience program on high school students in Qatar. Over ten cohorts from 2010 to 2020, 230 students participated in multidisciplinary, hands-on research experiences. The study used pre-post questionnaires and t-test analyses, with further meta-analysis conducted using Comprehensive Meta-Analysis (CMA) software to evaluate the program's effectiveness in shaping STEM attitudes. Significant findings emerged, with a notable large effect size (Cohen's d = 0.885), underscoring the program's efficacy in bolstering positive STEM attitudes among students. The study observed that research complexity and gender do influence the outcome of the program, aligning with the tenets of Social Cognitive Theory, which posits that both individual and contextual elements are influential in attitude formation and learning processes. Conclusively, the research substantiates that interdisciplinary, experiential learning significantly heightens student interest in STEM fields. It also points to the potential benefits of further explorations into the nuances of gender disparities and the complexity of research in enhancing the scope and impact of such educational programs., (Copyright © 2024 Elsevier Ltd. All rights reserved.)