Direction dependence of displacement time for two-fluid electroosmotic flow

Electroosmotic flow that involves one fluid displacing another fluid is commonly encountered in various microfludic applications and experiments, for example, current monitoring technique to determine zeta potential of microchannel. There is experimentally observed anomaly in such flow, namely, the displacement time is flow direction dependent, i.e., it depends if it is a high concentration fluid displacing a low concentration fluid, or vice versa. Thus, this investigation focuses on the displacement flow of two fluids with various concentration differences. The displacement time was determined experimentally with current monitoring method. It is concluded that the time required for a high concentration solution to displace a low concentration solution is smaller than the time required for a low concentration solution to displace a high concentration solution. The percentage displacement time difference increases with increasing concentration difference and independent of the length or width of the channel and the voltage applied. Hitherto, no theoretical analysis or numerical simulation has been conducted to explain this phenomenon. A numerical model based on finite element method was developed to explain the experimental observations. Simulations showed that the velocity profile and ion distribution deviate significantly from a single fluid electroosmotic flow. The distortion of ion distribution near the electrical double layer is responsible for the displacement time difference for the two different flow directions. The trends obtained from simulations agree with the experimental findings.     

基于大学生成功学习的美国本科新生体验计划

美国新生体验计划不是一个单独的项目、活动或课程,而是新生们在本科第一年中的经验总和。新生这些体验大都来自于大学为他们设计的课程以及课外活动,最终是为了让学生们更好地适应大学学习和生活并获得成功。     

Power,Penalty, and Critical Praxis: Employing Intersectionality in Educator Practices to Achieve School Equity

Intersectionality describes the ways interlocking systems of oppression, evidenced in various identity facets (e.g., race, class, gender, sexuality, religion, ability, and language), frame individuals' social worlds. An awareness of intersectionality can ensure PreK–12 school policies and practices meet the needs of a student population diversifying rapidly along multiple lines. We situate intersectionality within examples of common schooling dilemmas and pose suggestions for educators to employ intersectional thinking in their practice.     

Evolution of the nature-nurture controversy: Response to J. Philippe Rushton

The nature-nurture controversy is reviewed from the nineteenth century to the present. This review indicates that the nature-nuture issue has been highly controversial in psychology and education for long, mainly because of the oversimplified, either-or polarism of partisan views. In recent times, however, the old issue appears increasingly archaic. Expanding, interdisciplinary theory and research reveal complex interrelationships and evolutionary cognitive adaptations, etc. that can finally put the nature-nurture controversy to rest. This review provides background for a response to Rushton's critique of Yee (1992) in this issue.     

Self-Evaluations and Intergroup Attitudes in Children Aged Three to Nine

The effects of individual and group performance on children's evaluations of themselves and in- and out-group were examined. 128 girls and boys aged 3, 5, 7, and 9 years were randomly assigned to alleged "fast" or "slow" teams and asked to make various self, interpersonal, and intergroup evaluations. These showed strong developmental changes. Intergroup comparisons were made as early as 3 years, and this age group was sensitive to the relative standing of their team. However, the 5-year-old children showed markedly high self-evaluations, very strong in group bias in their evaluations of the 2 teams, and a high level of group cohesion irrespective of their own team's alleged performance. Gender differences were observed in self-evaluations after team assignment (boys responding more than girls to their team's alleged performance). The implications of these findings for recent work based on cognitive-developmental and social identity theories are discussed.     

Evaluation by medical students of the educational value of multi‐material and multi‐colored three‐dimensional printed models of the upper limb for anatomical education

For centuries, cadaveric material has been the cornerstone of anatomical education. For reasons of changes in curriculum emphasis, cost, availability, expertise, and ethical concerns, several medical schools have replaced wet cadaveric specimens with plastinated prosections, plastic models, imaging, and digital models. Discussions about the qualities and limitations of these alternative teaching resources are on‐going. We hypothesize that three‐dimensional printed (3DP) models can replace or indeed enhance existing resources for anatomical education. A novel multi‐colored and multi‐material 3DP model of the upper limb was developed based on a plastinated upper limb prosection, capturing muscles, nerves, arteries and bones with a spatial resolution of ～1 mm. This study aims to examine the educational value of the 3DP model from the learner's point of view. Students (n = 15) compared the developed 3DP models with the plastinated prosections, and provided their views on their learning experience using 3DP models using a survey and focus group discussion. Anatomical features in 3DP models were rated as accurate by all students. Several positive aspects of 3DP models were highlighted, such as the color coding by tissue type, flexibility and that less care was needed in the handling and examination of the specimen than plastinated specimens which facilitated the appreciation of relations between the anatomical structures. However, students reported that anatomical features in 3DP models are less realistic compared to the plastinated specimens. Multi‐colored, multi‐material 3DP models are a valuable resource for anatomical education and an excellent adjunct to wet cadaveric or plastinated prosections. Anat Sci Educ 11: 54–64. © 2017 American Association of Anatomists.     

Students’ beliefs and experiences of interdisciplinary learning

This study explored senior secondary students’ beliefs and experiences of learning an interdisciplinary curriculum, Liberal Studies, in Hong Kong. Through the analysis of focus-group interviews with 168 students, most of the students were found to enjoy or at least not resist interdisciplinary learning, and preferred to study real-world contemporary issues. More than half of the students, however, expressed their relative lack of confidence in interdisciplinary learning because of the difficulties they encountered in Independent Enquiry Studies and the public examination. The students were also found to have undertaken examination-oriented activities when the public examination approached. The study sheds light on the realization of interdisciplinary learning in secondary education in contexts where teacher-centred pedagogy and an accountability agenda remain influential.