Nanyang Technological University

About: Nanyang Technological University is a education organization based out in Singapore, Singapore. It is known for research contribution in the topics: Computer science & Catalysis. The organization has 48003 authors who have published 112815 publications receiving 3294199 citations. The organization is also known as: NTU & Universiti Teknologi Nanyang.

Facilitating preservice teachers' development of technological, pedagogical, and content knowledge (TPACK)

Abstract: Preparing preservice teachers for ICT integration in the classrooms is a key focus for many teacher education institutes. This paper examines the perceived development of preservice teachers in terms of their technological knowledge, pedagogical knowledge, content knowledge and the synthesis of such knowledge, i.e., the technological, pedagogical, and content knowledge (TPACK). A questionnaire adapted from Schmidt, Baran, Thompson, Mishra, Koehler, and Shin (2009) was validated using factor analyses and the preservice teachers' TPACK perceptions before and after their ICT course were examined. The results reveal statistical significant gains with good effect sizes. Regression analysis further reveals that technological knowledge, pedagogical knowledge and content knowledge are all significant predictors of preservice teachers' TPACK, with pedagogical knowledge having the largest impact. Implications for designing the ICT instruction of preservice teachers are discussed.

Band gap engineering and layer-by-layer mapping of selenium-doped molybdenum disulfide.

Abstract: Ternary two-dimensional dichalcogenide alloys exhibit compositionally modulated electronic structure, and hence, control of dopant concentration within each individual layer of these compounds provides a powerful tool to efficiently modify their physical and chemical properties. The main challenge arises when quantifying and locating the dopant atoms within each layer in order to better understand and fine-tune the desired properties. Here we report the synthesis of molybdenum disulfide substitutionally doped with a broad range of selenium concentrations, resulting in over 10% optical band gap modulations in atomic layers. Chemical analysis using Z-contrast imaging provides direct maps of the dopant atom distribution in individual MoS2 layers and hence a measure of the local optical band gaps. Furthermore, in a bilayer structure, the dopant distribution is imaged layer-by-layer. This work demonstrates that each layer in the bilayer system contains similar local Se concentrations, randomly distributed, pro...

Internet‐based interventions for smoking cessation

Abstract: BACKGROUND: The Internet is now an indispensable part of daily life for the majority of people in many parts of the world. It offers an additional means of effecting changes to behaviour such as smoking. OBJECTIVES: To determine the effectiveness of Internet-based interventions for smoking cessation. SEARCH METHODS: We searched the Cochrane Tobacco Addiction Group Specialized Register. There were no restrictions placed on language of publication or publication date. The most recent search was conducted in April 2013. SELECTION CRITERIA: We included randomized and quasi-randomized trials. Participants were people who smoked, with no exclusions based on age, gender, ethnicity, language or health status. Any type of Internet intervention was eligible. The comparison condition could be a no-intervention control, a different Internet intervention, or a non-Internet intervention. DATA COLLECTION AND ANALYSIS: Two authors independently assessed and extracted data. Methodological and study quality details were extracted using a standardized form. We extracted smoking cessation outcomes of six months follow-up or more, reporting short-term outcomes where longer-term outcomes were not available. We reported study effects as a risk ratio (RR) with a 95% confidence interval (CI). Clinical and statistical heterogeneity limited our ability to pool studies. MAIN RESULTS: This updated review includes a total of 28 studies with over 45,000 participants. Some Internet programmes were intensive and included multiple outreach contacts with participants, whilst others relied on participants to initiate and maintain use.Fifteen trials compared an Internet intervention to a non-Internet-based smoking cessation intervention or to a no-intervention control. Ten of these recruited adults, one recruited young adult university students and two recruited adolescents. Seven of the trials in adults had follow-up at six months or longer and compared an Internet intervention to usual care or printed self help. In a post hoc subgroup analysis, pooled results from three trials that compared interactive and individually tailored interventions to usual care or written self help detected a statistically significant effect in favour of the intervention (RR 1.48, 95% CI 1.11 to 2.78). However all three trials were judged to be at high risk of bias in one domain and high statistical heterogeneity was detected (I² = 53%), with no obvious clinical explanation. Pooled results from two studies of an interactive, tailored intervention involving the Internet and automated phone contacts also detected a significant effect (RR 2.05, 95% CI 1.42 to 2.97, I² = 42%). Results from a sixth study comparing an interactive but non-tailored intervention to control did not detect a significant effect, nor did the seventh study, which compared a non-interactive, non-tailored intervention to control. Three trials comparing Internet interventions to face-to-face or phone counselling also did not detect evidence of an effect, nor did two trials evaluating Internet interventions as adjuncts to other behavioural interventions. A trial in college students increased point prevalence abstinence after 30 weeks but had no effect on sustained abstinence. Two small trials in adolescents did not detect an effect on cessation compared to control.Fourteen trials, all in adult populations, compared different Internet sites or programmes. Pooled estimates from three trials that compared tailored and/or interactive Internet programmes with non-tailored, non-interactive Internet programmes did not detect evidence of an effect (RR 1.12, 95% CI 0.95 to 1.32, I² = 0%). One trial detected evidence of a benefit from a tailored email compared to a non-tailored one, whereas a second trial comparing tailored messages to a non-tailored message did not detect evidence of an effect. Trials failed to detect a benefit of including a mood management component (three trials), or an asynchronous bulletin board. AUTHORS' CONCLUSIONS: Results suggest that some Internet-based interventions can assist smoking cessation at six months or longer, particularly those which are interactive and tailored to individuals. However, the trials that compared Internet interventions with usual care or self help did not show consistent effects and were at risk of bias. Further research is needed despite 28 studies on the subject. Future studies should carefully consider optimising the interventions which promise most effect such as tailoring and interactivity.

Structure-designed synthesis of FeS2@C yolk–shell nanoboxes as a high-performance anode for sodium-ion batteries

Abstract: Pyrite (FeS2) is an attractive anode material for sodium-ion batteries (SIBs) with a high theoretical capacity of 894 mAh g−1. However, its practical application is greatly hindered by the rapid capacity fading caused by the large volume expansion upon sodiation. Tuning the morphology and structure at nanoscale and applying a higher cut-off voltage are essential to address this issue. Here, a facile etching method coupled with a novel sulfidation-in-nanobox strategy is developed to synthesize unique FeS2@C yolk–shell nanoboxes. The as-obtained FeS2@C nanoboxes reveal excellent sodium storage performance. The remarkable electrochemical properties are attributed to the elaborate yolk–shell nanoarchitecture. In particular, it delivers a high specific capacity of 511 mAh g−1 at 100 mA g−1 after 100 cycles. Furthermore, a high specific capacity of 403 mAh g−1 even at 5 A g−1 is delivered. Most impressively, a stable capacity of 330 mAh g−1 can still be retained at 2 A g−1 even after 800 cycles.

Peer-to-Peer Energy Trading in a Prosumer-Based Community Microgrid: A Game-Theoretic Model

Abstract: This paper proposes a novel game-theoretic model for peer-to-peer (P2P) energy trading among the prosumers in a community. The buyers can adjust the energy consumption behavior based on the price and quantity of the energy offered by the sellers. There exist two separate competitions during the trading process: 1) price competition among the sellers; and 2) seller selection competition among the buyers. The price competition among the sellers is modeled as a noncooperative game. The evolutionary game theory is used to model the dynamics of the buyers for selecting sellers. Moreover, an M-leader and N-follower Stackelberg game approach is used to model the interaction between buyers and sellers. Two iterative algorithms are proposed for the implementation of the games such that an equilibrium state exists in each of the games. The proposed method is applied to a small community microgrid with photo-voltaic and energy storage systems. Simulation results show the convergence of the algorithms and the effectiveness of the proposed model to handle P2P energy trading. The results also show that P2P energy trading provides significant financial and technical benefits to the community, and it is emerging as an alternative to cost-intensive energy storage systems.