Thermal mixing of two miscible fluids in a T-shaped microchannel     

Xu B  Wong TN  Nguyen NT  Che Z  Chai JC 《Biomicrofluidics》2010,4(4):44102

In this paper, thermal mixing characteristics of two miscible fluids in a T-shaped microchannel are investigated theoretically, experimentally, and numerically. Thermal mixing processes in a T-shaped microchannel are divided into two zones, consisting of a T-junction and a mixing channel. An analytical two-dimensional model was first built to describe the heat transfer processes in the mixing channel. In the experiments, de-ionized water was employed as the working fluid. Laser induced fluorescence method was used to measure the fluid temperature field in the microchannel. Different combinations of flow rate ratios were studied to investigate the thermal mixing characteristics in the microchannel. At the T-junction, thermal diffusion is found to be dominant in this area due to the striation in the temperature contours. In the mixing channel, heat transfer processes are found to be controlled by thermal diffusion and convection. Measured temperature profiles at the T-junction and mixing channel are compared with analytical model and numerical simulation, respectively.  相似文献   

Maintaining teachers’ face in the context of change: results from a study of Vietnamese college lecturers’ perceptions of face     

Thi Quynh Trang Nguyen 《Teachers and Teaching》2017,23(1):78-90

Gaining and saving face are very important in Vietnam as a mechanism of social control, including the professional behaviour of teachers. Interviews with 15 lecturers (aged 24–37) at a teacher training college in a Central Coast province of Vietnam illustrated the relationship between their concepts of face and their beliefs about good teaching. Most were still strongly influenced by traditional Confucian beliefs about the role and position of teachers, the nature of teachers’ knowledge and the relationship between teachers and students. On the other hand, some teachers also were aware of, and to a limited extent open to, more modern ideas that seemed to be related to broad social changes and reforms in approaches to teaching and learning in recent decades in Vietnam. The findings suggest that some teacher educators are uncertain about the value of traditional professional wisdom in the context of critical changes in society and in education. The research also suggests that the concepts of face and saving face are important for teachers’ sense of agency, and that Vietnamese educational authorities could increase the effectiveness of innovations in teacher education by paying attention to the influence of concepts of face on the teachers’ beliefs and behaviours.  相似文献   

Socio-scientific reasoning and environmental literacy in a field-based ecology class     

Andrew T. Kinslow  Troy D. Sadler  Hai T. Nguyen 《Environmental Education Research》2019,25(3):388-410

The complex environmental challenges humanity faces require citizens who are scientifically and environmentally literate. Many environmental education programs are situated in the field where students are immersed in their learning. These field-based activities are engaging but may lack opportunities for students to develop critical thinking and reasoning skills necessary to be environmentally literate. We suggest a socio-scientific issue (SSI) based teaching approach can increase epistemic engagement and lead to student gains in scientific and environmental literacy. This study describes how we modified an existing field-based ecology course, framing the learning around a local environmental socio-scientific issue. We used a convergent parallel mixed-methods approach to examine the changes in socio-scientific reasoning (SSR) over time for high school students in this course as a measure of scientific and environmental literacy. Results indicate that a focused SSI field-based environmental education curriculum can support development of socio-scientific reasoning and environmental literacy competencies among high school students.  相似文献   

Research Trends in Science Education from 2003 to 2007: A content analysis of publications in selected journals     

Min‐Hsien Lee  Ying‐Tien Wu 《International Journal of Science Education》2013,35(15):1999-2020

The present study was a follow‐up to Tsai and Wen’s (2005) earlier research, in which 802 articles published in the International Journal of Science Education, Science Education, and the Journal of Research in Science Teaching from 1998 to 2002 were analysed in terms of author’s nationality, research type, and research topic. In the present study a total of 869 papers published in the three journals from 2003 to 2007 were analysed, and the results were compared with those of Tsai and Wen. Moreover, this study also identified 31 highly‐cited papers published during 1998–2002 and 20 highly‐cited papers published during 2003–2007. The results showed that authors from countries other than the four major English‐speaking countries (i.e., the USA, the UK, Australia, and Canada) published an increasing number of articles in the past decade. During these five years (2003–2007), science educators showed relatively more interest in research topics involving the context of student learning. Besides, science educators have changed some of their research interests during 1998–2007, with a shift in the research topics from student conception learning and conceptual change (1998–2002) to student learning contexts (2003–2007). Moreover, the investigation of highly‐cited papers in the past decade revealed that studies on argumentation have gained significant attention among science educators.  相似文献   

Internet‐based Science Learning: A review of journal publications     

Silvia Wen‐Yu Lee  Ying‐Tien Wu  Meng‐Jung Tsai  Tzu‐Chien Liu  Fu‐Kwun Hwang 《International Journal of Science Education》2013,35(14):1893-1925

Internet‐based science learning has been advocated by many science educators for more than a decade. This review examines relevant research on this topic. Sixty‐five papers are included in the review. The review consists of the following two major categories: (1) the role of demographics and learners' characteristics in Internet‐based science learning, such as demographic background, prior knowledge, and self‐efficacy; and (2) the learning outcomes derived from Internet‐based science learning, such as attitude, motivation, conceptual understanding, and conceptual change. Some important conclusions are drawn from the review. For example, Internet‐based science learning is equally favorable, or in some cases more so, to learning for female students compared to male students. The learner's control is essential for enhancing students' attitudes and motivation toward learning in Internet‐based science learning environments. Nevertheless, appropriate guidance from teachers, moderators, or the Internet‐based learning environment itself is still quite crucial in Internet‐based science learning. Recommendations for future research related to the effects of Internet‐based science learning on students' metacognitive reflections, epistemological development, and worldviews are suggested.  相似文献   

Competition as cooperation     

C. Thi Nguyen 《体育哲学杂志》2017,44(1):123-137

Games have a complex, and seemingly paradoxical structure: they are both competitive and cooperative, and the competitive element is required for the cooperative element to work out. They are mechanisms for transforming competition into cooperation. Several contemporary philosophers of sport have located the primary mechanism of conversion in the mental attitudes of the players. I argue that these views cannot capture the phenomenological complexity of game-play, nor the difficulty and moral complexity of achieving cooperation through game-play. In this paper, I present a different account of the relationship between competition and cooperation. My view is a distributed view of the conversion: success depends on a large number of features. First, the players must achieve the right motivational state: playing for the sake of the struggle, rather than to win. Second, successful transformation depends on a large number of extra-mental features, including good game design, and social and institutional features.  相似文献   

Micro-optofluidic Lenses: A review   总被引：2，自引：0，他引：2  

Nam-Trung Nguyen 《Biomicrofluidics》2010,4(3)

This review presents a systematic perspective on the development of micro-optofluidic lenses. The progress on the development of micro-optofluidic lenses are illustrated by example from recent literature. The advantage of micro-optofluidic lenses over solid lens systems is their tunability without the use of large actuators such as servo motors. Depending on the relative orientation of light path and the substrate surface, micro-optofluidic lenses can be categorized as in-plane or out-of-plane lenses. However, this review will focus on the tunability of the lenses and categorizes them according to the concept of tunability. Micro-optofluidic lenses can be either tuned by the liquid in use or by the shape of the lens. Micro-optofluidic lenses with tunable shape are categorized according to the actuation schemes. Typical parameters of micro-optofluidic lenses reported recently are compared and discussed. Finally, perspectives are given for future works in this field.  相似文献   

Relationship of blood cholesterol to body composition, physical fitness, and dietary intake measures in third-grade children and their parents     

Hopper CA  Gruber MB  Munoz KD  MacConnie SE  Pfingston YM  Nguyen K 《Research quarterly for exercise and sport》2001,72(2):182-188

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Proteolysis of Sardine (Sardina pilchardus) and Anchovy (Stolephorus commersonii) by Commercial Enzymes in?Saline Solutions     

Chau Minh Le  Claire Donnay-Moreno  Sandrine Bruzac  Régis Baron  Huong Thi My Nguyen  Jean Pascal Bergé 《Food Technology and Biotechnology》2015,53(1):87-90

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Instructional leadership practices in Singapore   总被引：1，自引：0，他引：1  

Foo Seong David Ng  Thanh Dong Nguyen  Koon Siak Benjamin Wong  Kim Weng William Choy 《School Leadership & Management》2015,35(4):388-407

This paper presents a review of the literature on principal instructional leadership in Singapore. The authors investigated the dimensions of instructional leadership in the practices of Singapore principals and highlighted the strategies these leaders adopt to enact their instructional roles. Singapore principals were found to play an active role in defining the school vision and promoting the school climate. However, in the areas of curriculum implementation and classroom instruction, the middle management team in the school played more active roles as compared to principals. Five broad conclusions were discussed to provide perspectives on instructional leadership practices in Singapore. This paper also highlighted limitations on current instructional leadership research in Singapore and pointed to areas of future research.  相似文献