1,377 research outputs found
The trimer-based spin liquid candidate Ba4NbIr3O12
Ba4NbIr3O12, a previously unreported material with a triangular planar
geometry of Ir3O12 trimers, is described. Magnetic susceptibility measurements
show no magnetic ordering down to 1.8 K despite the Curie-Weiss temperature of
-13 K. The material has a very low effective magnetic moment of 0.80
{\mu}B/f.u. To look at the lower temperature behavior, the specific heat (Cp)
was measured down to 0.35 K; it shows no indication of magnetic ordering and
fitting a power law to Cp vs. T below 2 K yields the power {\alpha} = 3/4.
Comparison to the previously unreported trimer compound made with the 4d
element Rh in place of the 5d element Ir, Ba4NbRh3O12, is presented. The
analysis suggests that Ba4NbIr3O12 is a candidate spin liquid material.Comment: 19 pages, 7 main figures, 2 SI figure
New Method of Nickel Oxide as Hole Transport Layer and Characteristics of Nickel Oxide Based Perovskite Solar Cell
For perovskite solar cells, poly (2,3-dihydrothieno-1, 4-dioxin)-poly (styrenesulfonate) (PEDOT:PSS) is a common hole transport layer. However, PEDOT:PSS has a lot of drawbacks, such as irregular quality from distributors, poor electron blocker, and hygroscopic nature. On the other hand, NiOx has been reported that it can provide good stability and carrier mobility. From literature, NiOx was used to replace PEDOT:PSS as a hole transport layer with positive results since it is transparent as a thin film and also possesses compatible work function in perovskite solar cell bandgap alignment. In depositing NiOx as a thin film, many approaches have been developed. However, those approaches required the use of acute toxic chemicals, lengthy processing time, complicated chemical requirement, and/ or expensive equipment. In order to obtain NiOx thin film as a hole transport layer, we have developed a facile method to obtain a thin film of NiOx by simply mixing NiOx powder and HCl solution. This process only needs less than 5 minutes of chemical mixing time and the precursor can be immediately spin-coated on top of substrate. In addition, the equipment needed to obtain thin film NiOx is a spin coater and a hot plate.
With our quick, simple and inexpensive approach to get NiOx thin film for perovskite solar cells with inverted p-i-n structure, it is found that inverted perovskite solar cell with NiOx as a hole transport layer demonstrated higher open circuit voltage than perovskite solar cell fabricated with PEDOT:PSS, which enhanced solar cell power conversion efficiency. Our experiment has shown that NiOx thin film obtained by newly developed technique, exhibited promising material characteristics such as long lifetime decay. In our experiment, we also optimized the processing conditions of NiOx thin films to remove the light soaking effect caused by defects in NiOx layer. Hence, it is found that a quick, simple and inexpensive method enabled deposition of NiOx thin film as a promising hole transport layer for inverted p-i-n structure of perovskite solar cell
VIETNAMESE HIGH-SCHOOL TEACHERSâ PERCEPTIONS OF TPACK IN TEACHING ENGLISH AS A FOREIGN LANGUAGE
Technology-driven changes have led to the needs for knowledge and skills to integrate information and communication technology into instructional activities. This competence, described as the TPACK (technology, pedagogy and content knowledge), attracts relatively extensive scholarship in education. Further research, however, remains essential to develop further insights into teachersâ TPACK for foreign language education. Against such a backdrop, this study was conducted to examine Vietnamese teachersâ perceptions of TPACK in an EFL context. A 34-item survey adapted from BostancıoÄlu and Handley (2018) was used to collect data from 120 English teachers of 33 high schools in two Mekong Deltaâs provinces of Vietnam. Quantitative analysis showed that the teachers had a high level of basic computer and office technologies, and pedagogical content knowledge, but they rated their ability to integrate technologies with pedagogical content knowledge just above the average level. No significant differences in their TPACK were observed in terms of their teaching experience, technology training, and gender, except for technology use frequency. The findings confirm that trainers and educators should pay closer attention to supporting teachers both pre-service and in-service to develop TPACK as an integrated ability, instead of knowledge of technology per se. Besides, teachersâ TPACK levels interact with the use frequency, so it is crucial for teachers to use technology frequently to increase their TPACK self-efficacy.
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Dynamic conceptions of input, output and interaction: Vietnamese EFL lecturers learning second language acquisition theory
Although research into language teacher learning and cognition and teaching innovations oriented to communicative tasks has been abundant, little has addressed EFL teachersâ learning and conceiving of SLA principles underlying task-based language teaching. The study reported in the present thesis aims to fill this gap, specifically investigating teachersâ learning and conceiving of the notions of rich comprehensible language input, and authentic output and interaction, referred to as âSLA facilitating conditionsâ. The study explores three issues: teachersâ conceptions of the SLA facilitating conditions based on their practices in the tertiary English classroom; teachersâ perceptions of implementing the conditions, including factors affecting the implementation; and teachersâ perceived learning or change as a result of the process. Data for the study were obtained from six Vietnamese EFL lecturers who voluntarily participated in two short professional development workshops focusing on language input, and output and interaction. The data collection process was cumulative, beginning with pre-workshop interviews, followed by collection of lesson plans, lesson-based interviews, reflective writing, observation of lesson recordings, and a questionnaire. Analysis and interpretation followed a process of triangulation, and drew on the authorâs knowledge of the context and the teachersâ backgrounds. The results showed that the six teachers held contextualised conceptions of language input, and output and interaction. Although they believed that these conditions are important for language learning, their conceptions based on their implementation of the conditions reflected a synthetic product-oriented view of language learning and teaching. The teachers demonstrated an accommodation of the notion of comprehensible input into their existing pedagogical understanding, and revealed a conception of language output oriented to accuracy and fluency of specific target language items. Tasks and activities for interaction were mainly to provide students with contexts to use the target language items meaningfully rather than to communicate meaning. Most teachers delayed communicative tasks until their students were acquainted with the language content of the day. Such conceptions and practices had a connection with both conceptual/experiential and contextual factors, namely their prior training and experience, time limitations, syllabus, and studentsâ characteristics. The study also showed that although the teachersâ perceptions of the feasibility of promoting rich language input and authentic output and interaction were neutral, they thought promoting these conditions was relevant to studentsâ learning, congruent with their pre-existing beliefs about teaching English, and this granted them a sense of agency. The teachers also reported they became more aware of input, and output and interaction in teaching, confident, and purposeful in actions, and some reported a widened view of English language teaching. The study confirms that teacher learning and cognition is conceptually and contextually conditioned (Borg, 2006). In terms of this, it provides a model of how EFL teachersâ learning SLA is constrained by prior pedagogical beliefs and contextual conditions. In conjunction with previous research, the study provided evidence to suggest that communicative and task-based language teaching would appear to run counter to existing beliefs about teaching and practical conditions in Asian EFL situations. This lends support to a more flexible organic approach to employing tasks, perhaps considering the extent to which and in what ways communicative tasks are pedagogically useful to the EFL classroom. An implication is that for any new approaches like task-based language teaching to be incorporated into teachersâ existing repertoire, teachersâ conceptions of language input and interaction, and the conceptual and practical constraints influencing their thinking and practice should be considered and addressed. In a broader sense, approaches to teacher education and development should take a constructivist perspective on teacher learning, taking into account the local context of teaching and teachersâ existing cognition
MOODLE QUIZ TO SUPPORT VOCABULARY RETENTION IN EFL TEACHING AND LEARNING
This paper reports on a quasi-experimental study on the effect of vocabulary practice using the Moodle Quiz module on studentsâ vocabulary learning. Two intact classes including 73 tenth graders were randomly assigned as the experimental group and the control group. Both groups received formal face-to-face English instruction based on an English textbook for tenth Graders. The difference is that the control group did the usual paper-based vocabulary quizzes, whereas the experimental group worked on the same quizzes which were manipulated by Moodle Quiz. Vocabulary achievement tests were administered to measure the vocabulary retention of the participants before the intervention, at the end, and after a delayed period. The results showed that the experimental group had better vocabulary retention than the control group. Cohenâs effect size test further indicated that the effect on vocabulary retention was of a large degree. Further exploration showed that the participants were engaged and motivated to practice vocabulary on Moodle. Findings of the study and confirm the effectiveness of blended learning in EFL instruction, and lend support to the use of technology to compensate limited classroom instruction, and create enhanced practice opportunities for EFL learners. Article visualizations
EMI in Vietnam: What High School Teachers Think and Do
The current case study was driven by a recent policy on using English as a medium of instruction (EMI) in the mainstream school system in Vietnam. It aimed to explore what science teachers believed and reported doing about EMI in teaching science subjects in the high school context. Nine EMI teachers of different science subjects at a specialized high school in the Mekong Delta of Vietnam participated in a semi-structured interview. Thematic analysis revealed the perceived positive impacts on teachersâ and studentsâ English proficiency, and negative influences on science content coverage. In practice, the teachers reported a focus on simple contents, explaining specialized terminologies and key concepts as the input. They mainly employed a lecture style and teacher initiation-student response interaction, switching between English and Vietnamese during their lessons. These results imply that EMI across the curriculum has the potential to improve English proficiency of students, but the EMI policy needs to consider its transparency in goals and communication to stakeholders especially teachers and school managers.  
INFLUENCE OF MOTIVATION, SOCIAL SUPPORT AND BASIC NEED SATISFACTION ON BURNOUT AMONG FOOTBALL PLAYERS IN BANGLADESH
Football is ruminated in the guise of the most foremost and modish sports in Bangladesh reminiscent of other countries of the world, as sports are frolicked under prodigious coercion, young football athletes perpetually stumble into divergent circumstances which incorporate affirmative and apathetic scenarios confiding in athleteâs concurrent whereabouts & prospect dispatch which narrates to burnout. The perusal maneuvered motivation as an independent variable, basic need satisfaction which exerted as mediator variable and social support plied as moderator variable that governed young playerâs burnout to ebb or to surge. The purpose of the study was to interrogate the relationship among burnout and motivation, social support, basic need satisfaction. The paper pursued quantitative technique to amass accessible data in which five hundred and twelve adolescent football players were surveyed in Bangladesh and their age ranged between 15 to 25 years. The survey questionnaire was in four tranches encompassing Athlete burnout questionnaire, Basic Need Satisfaction scale, Motivation questionnaire & SARASON Social Support scale; furthermore, the study wielded Pearson Correlation analysis, Moderated regression analysis and Process in the course of score reckoning. The study instituted that motivation and social support unconstructively associated with burnout and basic need satisfaction allied moderately with the burnout, when burnout escalates, motivation, social support, and basic need satisfaction went down or when burnout dwindles all of the independent variables augment. The research formed factors relationship with each other and comprehended coping tactic how athletes could trounce their melancholy, fatigue and mental grievance to burgeon their sports recital and would scrutinize players commotion towards their contented & constructive precinct as well
INFLUENCE OF MOTIVATION, SOCIAL SUPPORT AND BASIC NEED SATISFACTION ON BURNOUT AMONG FOOTBALL PLAYERS IN BANGLADESH
Football is ruminated in the guise of the most foremost and modish sports in Bangladesh reminiscent of other countries of the world, as sports are frolicked under prodigious coercion, young football athletes perpetually stumble into divergent circumstances which incorporate affirmative and apathetic scenarios confiding in athleteâs concurrent whereabouts & prospect dispatch which narrates to burnout. The perusal maneuvered motivation as an independent variable, basic need satisfaction which exerted as mediator variable and social support plied as moderator variable that governed young playerâs burnout to ebb or to surge. The purpose of the study was to interrogate the relationship among burnout and motivation, social support, basic need satisfaction. The paper pursued quantitative technique to amass accessible data in which five hundred and twelve adolescent football players were surveyed in Bangladesh and their age ranged between 15 to 25 years. The survey questionnaire was in four tranches encompassing Athlete burnout questionnaire, Basic Need Satisfaction scale, Motivation questionnaire & SARASON Social Support scale; furthermore, the study wielded Pearson Correlation analysis, Moderated regression analysis and Process in the course of score reckoning. The study instituted that motivation and social support unconstructively associated with burnout and basic need satisfaction allied moderately with the burnout, when burnout escalates, motivation, social support, and basic need satisfaction went down or when burnout dwindles all of the independent variables augment. The research formed factors relationship with each other and comprehended coping tactic how athletes could trounce their melancholy, fatigue and mental grievance to burgeon their sports recital and would scrutinize players commotion towards their contented & constructive precinct as well. Article visualizations
TASK-BASED LANGUAGE TEACHING IN VIETNAM: RESEARCH TRENDS, FINDINGS, AND IMPLICATIONS
It is widely assumed that task-based language teaching (TBLT) has been effectively applied in EFL contexts. In Vietnam, abundant research has been implemented to examine its effects on English proficiency as well as to identify perceptions and attitudes of both teachers and learners towards using this approach in classroom contexts. This paper aims to synthesize trends in research on task-based language teaching in the context by reviewing results extracted from a corpus of 60 studies. Key aspects like effects, challenges, teacher/learner perceptions and attitudes were selected for analysis and synthesis. The results revealed that the research tended to focus more on production skills than receptive skills, and that the implementation of TBLT was reported to cause challenges for teachers, while learners tended to hold positive attitudes toward the approach. Based on the research findings, some lessons were drawn for pedagogy and future research. For successful TBLT implementation, it is suggested that teachers are informed of the effects, engaged in reflections and that exams should be shifted towards communicative competence assessment. Future research could increase sample size and treatment duration, and especially address the challenges teachers, as the main agent, encounter in implementation. Article visualizations
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