Relationships between the quality of blended learning experience, self-regulated learning, and academic achievement of medical students: a path analysis

Salah Eldin Kassab,1 Ahmad I Al-Shafei,2 Abdel Halim Salem,3 Sameer Otoom4 1Department of Medical Education, Faculty of Medicine, Suez Canal University, Ismailia, Egypt; 2Department of Physiology, College of Medicine, King Saud University, Riyadh, Kingdom of Saudi Arabia; 3Department of Anatomy, College of Medicine and Medical Sciences, Arabian Gulf University, Manama, Bahrain; 4Royal College of Surgeons in Ireland, Medical University of Bahrain (RCSI Bahrain), Busaiteen, Bahrain Purpose: This study examined the relationships between the different aspects of students' course experience, self-regulated learning, and academic achievement of medical students in a blended learning curriculum.Methods: Perceptions of medical students (n=171) from the Royal College of Surgeons in Ireland, Medical University of Bahrain (RCSI Bahrain), on the blended learning experience were measured using the Student Course Experience Questionnaire (SCEQ), with an added e-Learning scale. In addition, self-regulated learning was measured using the Motivated Strategies for Learning Questionnaire (MSLQ). Academic achievement was measured by the scores of the students at the end of the course. A path analysis was created to test the relationships between the different study variables. Results: Path analysis indicated that the perceived quality of the face-to-face component of the blended experience directly affected the motivation of students. The SCEQ scale "quality of teaching" directly affected two aspects of motivation: control of learning and intrinsic goal orientation. Furthermore, appropriate course workload directly affected the self-efficacy of students. Moreover, the e-Learning scale directly affected students' peer learning and critical thinking but indirectly affected metacognitive regulation. The resource management regulation strategies, time and study environment, and effort regulation directly affected students' examination scores (17% of the variance explained). However, there were no significant direct relationships between the SCEQ scales and cognitive learning strategies or examination scores.Conclusion: The results of this study will have important implications for designing blended learning courses in medical schools. Keywords: student course experience, examination scores, structural equation modelin

Pyrolysis kinetics of tetrabromobisphenol a (TBBPA) and electric arc furnace dust mixtures

This work assesses the decomposition kinetics and the overall pyrolysis behavior of Tetrabromobisphynol A (TBBPA) mixed with Electric Arc Furnace Dust (EAFD) using experimental data from thermogravimetric analysis (TGA). Mixtures of both materials with varying EAFD:TBBPA ratios (1:1, 1:2, 1:3 and 1:4) were pyrolyzed in an inert atmosphere under dynamic heating conditions at different heating rates (5, 10, 30 and 50 °C/min). The pyrolysis of pure TBBPA proceeded through two decomposition steps: debromination and volatilization of debromination products. This is followed by char formation that also involves release of volatile organic matter. However, the pyrolysis of EAFD:TBBPA mixture proves to be more complex in nature due to the occurrence of parallel solid-liquid reactions that result in the release of HBr and other volatile organic compounds (VOC) coupled with bromination of metal oxides. Subsequent chemical events encompass evaporation of metal bromides and finally reduction of the remaining metal oxides, most notably iron oxide, into their metallic form by the char. Three models, namely, Kissinger, Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS), were deployed to derive kinetics parameters. Generally, it was found that the presence of EAFD has led to an increase in the apparent activation energy for the first stage of TBBPA decomposition due to the reduced evaporation of TBBPA

Thermal analysis on the pyrolysis of tetrabromobisphenol A and electric arc furnace dust mixtures

The pyrolysis of Tetrabromobisphenol A (TBBPA) mixed with electric arc furnace dust (EAFD) was studied using thermogravimetric analysis (TGA) and theoretically analyzed using thermodynamic equilibrium calculations. Mixtures of both materials with varying TBBPA loads (1:1 and 1:3) were prepared and pyrolyzed in a nitrogen atmosphere under dynamic heating conditions at heating rates of 5 and 10 °C/min. The mixtures degraded through several steps, including decomposition of TBBPA yielding mainly HBr, bromination of metal oxides, followed by their evaporation in the sequence of CuBr3, ZnBr2, PbBr2, FeBr2, MnBr2, KBr, NaBr, CaBr2, and MgBr2, and finally reduction of the remaining metal oxides by the char formed from decomposition of TBBPA. Thermodynamic calculations suggest the possibility of selective bromination of zinc and lead followed by their evaporation, leaving iron in its oxide form, while the char formed may serve as a reduction agent for iron oxides into metallic iron. However, at higher TBBPA volumes, iron bromide forms, which can also be evaporated at a temperature higher than those of ZnBr2 and PbBr2. Results from this work provide practical insight into selective recovery of valuable metals from EAFD while at the same time recycling the hazardous bromine content in TBBPA

Treatments of electric arc furnace dust and halogenated plastic wastes: A review

This paper reviews the latest research findings on the combined treatment of both electric arc furnace dust (EAFD) and halogenated plastic wastes, mainly polyvinyl chloride (PVC) and brominated flame-retardants (BFRs). EAFD contains heavy metals (Zn, Pb, Fe, Cd, etc.); its disposal using the traditional landfilling method threatens the environment. On the other hand, halogenated plastic wastes accumulate annually at an alarming rate due to their excessive production, consumption, and disposal. PVC, for example, does not decompose naturally; it remains one of the most dangerous plastics, as it contains high proportions of chlorine that is responsible for hazardous emissions of chlorinated organic compounds (dioxins) and hydrochloric acid vapour. Recent research have focused on the combined treatment of PVC/BFRs and EAFD. HCl/HBr acids produced from the pyrolysis of PVC/BFRs can react with the metal oxides in the EAFD to convert them into readily separable metal halides. Alternatively, several researches illustrated the advantages of using additives such as metal oxides during the incineration treatment of waste PVC/BFRs to fix gaseous HCl/HBr, and consequently, EAFD would be considered an excellent and cheap candidate for PVC dechlorination, as well as dehalogenation of other halogenated plastics during thermal recycling processes. In this review we critically discuss literature findings on thermal treatment of PVC/BFR materials under oxidative and pyrolytic environments, typically at temperatures of 200–900 °C in presence of metal oxides or EAFD. We also discuss the treatment/disposal routes for both waste materials (EAFD and halogenated plastic wastes) and the environmental impact of these disposal options. The review, finally, proposes the research necessary to minimize the hazards of these waste materials; Several future research areas were identified including the need to study the behaviour of real EAFD-plastic waste mixtures under oxidative thermal conditions with focus on both the selective recovery of metals and identification, quantification, and minimization of halogenated organic compounds released during the combined thermal treatment