Search for: All records

Abstract Nitrogen (N) doped graphene materials have been synthesized using the sole precursor adenine on the Ir(111) and Ru(0001) surfaces. X-ray photoelectron spectroscopy and scanning tunneling microscopy (STM) have been used to characterize the obtained N-doped graphene materials. Several graphitic and pyridinic N dopants have been identified on the atomic scale by combining STM measurements and STM simulations based on density functional theory calculations. 

The study systematically compared the N2O-reducing functional performances and the genomic features of two N2O-reducing isolates, aimed to screen out effective N2O-reducing bacteria with strong environmental adaption, and explore the possible regulation.

Two N2O reducers, namely, Pseudomonas veronii DM15 (DM15) and Pseudomonas frederiksbergensis DM22 (DM22), isolated from paddy soil were selected. Their N2O-reducing abilities, and nosZ gene transcript abundance were determined under different temperatures (20°C, 30°C, 40°C) and oxygen concentrations (0%, 10%, 21%), and the whole genomes were sequenced by Illumina sequencing. The results showed that both DM15 and DM22 exhibited the strongest N2O reducing activity at 30°C and under anaerobic conditions. In comparison, DM15 generally exhibited significantly higher N2O reducing abilities and nosZ gene expression than DM22 under all tested conditions. In addition, DM15 possessed obviously higher expression potentials (codon adaptation index (CAI) value) of nos genes than DM22, and the nos cluster of the former contained a transcriptional regulator gene of dnr, while the latter did not.

The results indicate that DM15 showed obviously stronger N2O-reducing abilities than DM22 under various conditions, which might be closely associated with its dnr transcriptional regulator, and thus promoting the higher transcriptional activities of nos genes. Although anaerobic conditions were the optimal conditions for N2O reduction in both strains, DM15 still reduced a certain amount of N2O even under aerobic conditions.

 

There is a cohesive body of research on the effectiveness of problem-based learning (PBL) for a wide range of learner groups across different disciplines in engineering education. On the other hand, there is a growing interest in using immersive technologies such as virtual reality (VR) in engineering education. While there are many literature review articles on each of these subjects separately, there is a lack of review articles on the application of combined PBL-VR learning environments in engineering education. This paper provides an assessment of the applications and potential of implementing immersive technologies in a PBL setting to utilize the advantages of both paradigms. More specifically, this paper aims to provide insights related to two main questions: (1) where (in what disciplines/subjects) PBL and VR have been used together in engineering education? And, (2) how are VR and PBL integrated and used in engineering education? The first question is investigated by performing a bibliometric analysis of relevant papers published in the proceedings of previous ASEE annual conferences. The second question is explored by performing a literature review and classification of ASEE papers that discuss the use of VR in conjunction with PBL. Our findings reveal a gap between the application of integrated PBL and VR across different disciplines in engineering education. We also analyze the trends related to PBL and VR application in engineering education over time. Finally, we identify and propose future opportunities related to the combination of PBL and immersive technologies, including but not limited to immersive simulation-based learning (ISBL) and incorporating artificial intelligence (AI) into immersive virtual/simulated learning environments used in engineering education.