Sealing SU-8 microfluidic channels using PDMS

A simple method of irreversibly sealing SU-8 microfluidic channels using PDMS is reported in this paper. The method is based on inducing a chemical reaction between PDMS and SU-8 by first generating amino groups on PDMS surface using N₂ plasma treatment, then allowing the amino groups to react with the residual epoxy groups on SU-8 surface at an elevated temperature. The N₂ plasma treatment of PDMS can be conducted using an ordinary plasma chamber and high purity N₂, while the residual epoxy groups on SU-8 surface can be preserved by post-exposure baking SU-8 at a temperature no higher than 95 °C. The resultant chemical bonding between PDMS and SU-8 using the method create an interface that can withstand a stress that is greater than the bulk strength of PDMS. The bond is permanent and is long-term resistant to water. The method was applied in fabricating SU-8 microfluidi-photonic integrated devices, and the obtained devices were tested to show desirable performance.     

Changing Teachers' Thinking Through Critical Constructivism and Critical Action Research

Abstract

This paper studies attempts to change teachers' thinking towards a construc‐tivist perspective within science education. The contexts surrounding the research are important: ideas of critical constructivism, critical action research and the work of Paulo Freire are brought to bear on teacher education in Recife, northeastern Brazil. A professional development course was designed to explore with secondary science teachers some elements of constructivist thinking, and to shape action research projects within their own classrooms. The course design is described, along with some of the responses of the participants both during and after they undertook their projects within their secondary schools. The responses highlight the tensions of trying to innovate with ‘non‐traditional methods’ within traditional situations, the advantages and drawbacks of ‘freeing up’ classroom discussion and authoritative teaching.     

Appreciating the Complexity of Project Management Execution: Using Simulation in the Classroom

As the popularity and importance of project management increase, so does the need for well‐prepared project managers. This article discusses our experiences using a project management simulation in undergraduate and MBA classes to help students better grasp the complexity of project management. This approach gives students hands‐on experience with many facets in the project management life cycle and provides them with feedback on their performance as project managers. This article provides an overview of the simulation exercises, guidance for classroom integration, and evidence of effectiveness.     

Education and inequality in India: a classroom view

Policy‐makers in the 1980s sought to restructure education on the basis of market principles, and in particular to effect site‐based or devolved school management. The reform of ‘management’, therefore, has become of central importance for policy makers. This paper explores two influences on the contemporary management of education: first, intellectual ideas drawn from postmodernist theory and chaos theory; and second, the culture of postmodernism. It argues that they disrupt and undermine traditional assumptions in educational administration and management. In response, modernist management theorists and policy makers may attempt to refine their legitimatory rhetorics by appealing in a superficial way to these cultural and intellectual changes, thereby seeking to neutralize their disruptive potential. In sum, a modernist makeover may be in the making.

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SOCIAL SCIENCE INFORMATION FINDING FOR SOCIAL POLICY ON AGING AND RELATED COURSES

This article examines the role that content on social science information finding plays in social policy on aging and related courses. First, there is considerable value for students having first‐hand knowledge of and involvement in social science information searching. Second, new developments in information services such as citation indexing and subject area abstracts and indexes in aging and other fields offer new assistance for students. Finally, incorporation of information services content through practical and comprehensive classroom approaches is discussed. Through incorporating information services content in aging policy and related courses students are better equipped to meet the demands of an information age.     

Timing of ball release in overarm throws affects ball speed in unskilled but not skilled individuals

We tested the hypothesis that variability in the timing of ball release in overarm throws affects ball speed. Nine unskilled and six skilled throwers made 30 throws fast and accurately from a sitting and standing position. Angular positions of finger and arm segments were recorded with search-coils at 1000 Hz; ball speed was measured with a radar gun. The time of ball release from the fingertips was measured with respect to seven arm kinematic reference points. Mean timing windows for ball release were 28?ms for unskilled throwers and 7?ms for skilled throwers. Mixed-model analyses of variance showed that a there was a statistically significant relationship between ball speed and the timing of ball release in unskilled throwers, but not in skilled throwers. This was presumably due to the difference in variability of the timing of ball release between the two groups. In contrast, skilled throwers showed a relationship between ball speed and peak forearm angular velocity (one measure of arm speed). We conclude that although variability in the timing of ball release can affect ball speed, this is only a major factor in unskilled throwers. When skilled throwers throw fast, variability in ball speed is due to variability in arm speed.