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Xinyu Lu Saurin Patel Meng Zhang Sang Woo Joo Shizhi Qian Amod Ogale Xiangchun Xuan 《Biomicrofluidics》2014,8(2)
Electrophoresis plays an important role in many applications, which, however, has so far been extensively studied in Newtonian fluids only. This work presents the first experimental investigation of particle electrophoresis in viscoelastic polyethylene oxide (PEO) solutions through a microchannel constriction under pure DC electric fields. An oscillatory particle motion is observed in the constriction region, which is distinctly different from the particle behavior in a polymer-free Newtonian fluid. This stream-wise particle oscillation continues until a sufficient number of particles form a chain to pass through the constriction completely. It is speculated that such an unexpected particle oscillating phenomenon is a consequence of the competition between electrokinetic force and viscoelastic force induced in the constriction. The electric field magnitude, particle size, and PEO concentration are all found to positively affect this viscoelasticity-related particle oscillation due to their respective influences on the two forces. 相似文献
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Modelling of switching systems in bond graphs using the concept of switched power junctions 总被引：1，自引：0，他引：1
Modelling of switching systems using bond graph is a research issue. There have been many proposals in this context. However, there are many issues that need consideration. This paper proposes the concept of switched power junctions that is a generalisation of the conventional junction concept in bond graph modelling. This approach removes most of the difficulties associated with other methodologies. This method ensures that causality remains invariant during mode switching thus keeping the state vector and its dimension time invariant. Further, the switched power junction displays all feasible system modes at the same time on the same graph. This concept is further illustrated through simulation using examples of switching systems in the electrical domain. 相似文献
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Zaytoon Amod Deidré Heafield Joseph Seabi 《International Journal of Disability, Development & Education》2018,65(4):428-441
The search for assessment procedures that are more fair and useful have led to the investigation of alternatives to traditional forms of intellectual assessment. This study explored an alternative which combined a dynamic assessment approach with the Planning, Attention, Simultaneous and Successive Processing (PASS) model of cognitive processing. The aim was to investigate the effectiveness of a planning intervention programme based on Feuerstein’s criteria for Mediated Learning Experience (MLE) with a group of Grade 4 and 5 remedial school learners who presented with a range of barriers to learning. Twenty six learners were assigned to the experimental group and 25 to the control group. The results showed that there was a significant improvement in the experimental group’s Planning Scale score on the Cognitive Assessment System, following the intervention. These results imply that children often have far greater potential than is realised and that intentional mediation can help to enhance cognitive functioning and assist in further developing children’s learning potential. 相似文献
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