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   

Acute protease supplementation effects on muscle damage and recovery across consecutive days of cycle racing     

Cecilia M. Shing  Suzzen Chong  Matthew W. Driller  James W. Fell 《European Journal of Sport Science》2016,16(2):206-212

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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   

Historical Evolution of the Field View and Textbook Accounts     

Pocovi  M. Cecilia  Finley  Fred N. 《Science & Education》2003,12(4):387-396

We analyzed how two basic electromagnetism textooks approach the concept of electric field. We limited our study to the reasons given in these textbooks for the introduction of the field representation and to how accurate, coherent, and complete these reasons are. Because many times historical reasons are intertwined with textbooks' explanations of physical phenomena, we used the historical evolution of the field representation to guide our analysis. The analysis shows that one textbook mixes up the historical and pedagogical reasons for the introduction of the concept of field. The other one presents a sketch that might lead students to understand the field and the action-at-a-distance views as supplementing each other.  相似文献   

Explanations of attitudes to change: Colombian mathematics teachers’ conceptions of the crucial determinants of their teaching practices of beginning algebra   总被引：1，自引：0，他引：1  

Cecilia Agudelo-Valderrama  Barbara Clarke  Alan J. Bishop 《Journal of Mathematics Teacher Education》2007,10(2):69-93

This article arises from a study whose overall purpose was to investigate the relationship between Colombian mathematics teachers’ conceptions of beginning algebra and their conceptions of their own teaching practices. The teachers’ understandings of their teaching practices were explored with a view to unravelling their conceptions of change in their teaching. Focusing on the perspectives of teachers afforded opportunities that exposed the powerful role that the teachers’ conceptions of social/institutional factors of teaching played in their conceptions of their practices. The degree to which the teachers attributed these (external) factors as crucial reasons for what they do in their teaching was the basis of a categorisation of their conceptions of the crucial determinants of their teaching practices into three types. The findings are particularly relevant to our understanding of the stability of mathematics teaching approaches in the Colombian context but have likely implications for a range of international education contexts. Specific implications for the development of the research into teachers’ conceptions of mathematics and its teaching, and for teacher education programmes are presented.

Alan J. BishopEmail:

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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   

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   

USING FOCUS GROUPS AS AN EDUCATIONAL METHODOLOGY: DECONSTRUCTING STEREOTYPES AND SOCIAL WORK PRACTICE MISCONCEPTIONS CONCERNING AGING AND OLDER ADULTS     

Harriet L. Cohen  Mark H. Sandel  Cecilia L. Thomas  Thomas R. Barton 《Educational gerontology》2013,39(4):329-346

During the coming years the number of older adults will increase dramatically, which will require a corresponding increase in the number of social workers who have accurate knowledge of this population. This article reports the impact focus groups with older adults and with service providers who work with older adults and their families have on baccalaureate social work (BSW) students. We find that BSW students exposed to focus groups have their negative attitudes about older adults and service providers deconstructed and replaced with more positive and accurate information about older adults. When students' misconceptions about older adults are confronted, they become more interested in choosing geriatric social work as a career option.  相似文献   

Temporal aspects of the VO2 response at the power output associated with VO2peak in well trained cyclists--implications for interval training prescription     

Laursen PB  Shing CM  Jenkins DG 《Research quarterly for exercise and sport》2004,75(4):423-428

The power output achieved at peak oxygen consumption (VO2peak) and the time this power can be maintained (i.e., Tmax) have been used in prescribing high-intensity interval training. In this context, the present study examined temporal aspects of the VO2 response to exercise at the cycling power that output well trained cyclists achieve their VO2peak (i.e., Pmax). Following a progressive exercise test to determine VO2peak, 43 well trained male cyclists (M age = 25 years, SD = 6; M mass = 75 kg, SD = 7; M VO2peak = 64.8 ml x kg(-1) x min(-1), SD = 5.2) performed two Tmax tests 1 week apart. Values expressed for each participant are means and standard deviations of these two tests. Participants achieved a mean VO2peak during the Tmax test after 176 s (SD = 40; M = 74% of Tmax, SD = 12) and maintained it for 66 s (SD = 39; M = 26% of Tmax, SD = 12). Additionally, they obtained mean 95% of VO2peak after 147 s (SD = 31; M = 62% of Tmax, SD = 8) and maintained it for 95 s (SD = 38; M = 38% of Tmax, SD = 8). These results suggest that 60-70% of Tmax is an appropriate exercise duration for a population of well trained cyclists to attain VO2peak during exercise at Pmax. However, due to intraparticipant variability in the temporal aspects of the VO2 response to exercise at Pmax, future research is needed to examine whether individual high-intensity interval training programs for well trained endurance athletes might best be prescribed according to an athlete's individual VO2 response to exercise at Pmax.  相似文献