Cell separation and transportation between two miscible fluid streams using ultrasound     

Liu Y  Hartono D  Lim KM 《Biomicrofluidics》2012,6(1):12802-1280214

This paper presents a two-stream microfluidic system for transporting cells or micro-sized particles from one fluid stream to another by acoustophoresis. The two fluid streams, one being the original suspension and the other being the destination fluid, flow parallel to each other in a microchannel. Using a half-wave acoustic standing wave across the channel width, cells or particles with positive acoustic contrast factors are moved to the destination fluid where the pressure nodal line lies. By controlling the relative flow rate of the two fluid streams, the pressure nodal line can be maintained at a specific offset from the fluid interface within the destination fluid. Using this transportation method, particles or cells of different sizes and mechanical properties can be separated. The cells experiencing a larger acoustic radiation force are separated and transported from the original suspension to the destination fluid stream. The other particles or cells experiencing a smaller acoustic radiation force continue flowing in the original solution. Experiments were conducted to demonstrate the effective separation of polystyrene microbeads of different sizes (3 μm and 10 μm) and waterborne parasites (Giardia lamblia and Cryptosporidium parvum). Diffusion occurs between the two miscible fluids, but it was found to have little effects on the transport and separation process, even when the two fluids have different density and speed of sound.  相似文献   

Exploring the Usefulness of Kelly's Personal Construct Theory in Assessing Student Learning in Science Courses     

Carolin Kreber  Heather Castleden  Nina Erfani  Joan Lim  Tarah Wright 《Teaching in Higher Education》2013,18(3):431-445

We explore the utility of George Kelly's Personal Construct Theory, specifically his repertory grid technique, to the assessment of student learning in undergraduate science courses. We provide an in-depth review of the assumptions underlying Personal Construct Theory and how these were reflected in the repertory grid technique Kelly developed. We explain how an adapted version of the repertory grid, sharing some yet not all of Kelly's assumptions, was utilised as a research tool in a recent study involving science instructors and their students. We argue that as well as having applicability as an innovative research tool, an adapted version of Kelly's repertory grid is a useful heuristic for university teachers when used as a classroom assessment technique (CAT) and indicate several features it shares with the more widely-known conceptual mapping technique, which has been used in the study of science teaching and learning for many years. We conclude by highlighting several advantages the use of repertory grids has for both students and instructors.  相似文献   

Making learning visible in initial teacher education: a pedagogical characterisation scheme     

Peter G. Taylor  Ee Ling Low  Kam Ming Lim  Chenri Hui 《Educational Research for Policy and Practice》2013,12(3):193-209

This paper reports the development of a scheme of characterising pedagogical practices in initial teacher education classes. The scheme is intended to provide baseline data on classroom pedagogical practices in Singapore’s sole provider of initial teacher education (ITE). This study is original in that the research team has found no reports of independent research to characterise, through video analysis of classroom practices, the pedagogical practices experienced during ITE. By characterising the pedagogical practices of a purposive sample of ITE lessons run at the National Institute of Education Singapore, this study contributes an initial scheme to produce detailed and layered representations of pedagogical practices through video recordings, which opens a new approach to research on teacher education. The implications with regard to teacher education policy and practice will be discussed.  相似文献   

Formation control and collision avoidance for a class of multi-agent systems     

Yutong Liu  Hongjun Yu  Peng Shi  Cheng-Chew Lim 《Journal of The Franklin Institute》2019,356(10):5395-5420

In this paper, a control scheme is proposed for a group of elliptical agents to achieve a predefined formation. The agents are assumed to have the same dynamics, and communication among the agents are limited. The desired formation is realized based on the reference formation and the mapping decision. In the control design, searching algorithms for both cases of minimum distance and tangents are established for each agent and its neighbors. In order to avoid collision, an optimal path planning algorithm based on collision angles, and a self-center-based rotation algorithm are also proposed. Moreover, randomized method is used to provide the optimal mapping decision for the underlying system. Two examples and analyses are presented to demonstrate the effectiveness and potential of the new control scheme.  相似文献   

ATP translocation and chloroplast biology     

Chia P Voon  Boon L Lim 《国家科学评论(英文版)》2019,6(6):1073

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Impact of combining data from multiple instruments on performance of patient-based real-time quality control     

Qianqian Zhou  Tze Ping Loh  Tony Badrick  Chun Yee Lim 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2021,31(2)

IntroductionIt is unclear what is the best strategy for applying patient-based real-time quality control (PBRTQC) algorithm in the presence of multiple instruments. This simulation study compared the error detection capability of applying PBRTQC algorithms for instruments individually and in combination using serum sodium as an example.Materials and methodsFour sets of random serum sodium measurements were generated with differing means and standard deviations to represent four simulated instruments. Moving median with winsorization was selected as the PBRTQC algorithm. The PBRTQC parameters (block size and control limits) were optimized and applied to the four simulated laboratory data sets individually and in combination.ResultsWhen the PBRTQC algorithm were individually optimized and applied to the data of the individual simulated instruments, it was able to detect bias several folds faster than when they were combined. Similarly, the individually applied algorithms had perfect error detection rates across different magnitudes of bias, whereas the error detection rates of the algorithm applied on the combined data missed smaller biases. The performance of the individually applied PBRTQC algorithm performed more consistently among the simulated instruments compared to when the data were combined.DiscussionWhile combining data from different instruments can increase the data stream and hence, increase the speed of error detection, it may widen the control limits and compromising the probability of error detection. The presence of multiple instruments in the data stream may dilute the effect of the error when it only affects a selected instrument.  相似文献   

Jon Lauglo, Peter Lang, Frankfurt, Se-Yung Lim, Klaus Schaack (Eds.), Education, Training and Contexts Studies and Essays, ISBN 3-631-39547-7, US edn 0-8204-5981-X, 2002 (433pp.)..     

Jon Lauglo  Peter Lang  Frankfurt  Se-Yung Lim  Klaus Schaack  Education  Training  Contexts Studies  Essays  ISBN ---  US edn ---X  . 《International Journal of Educational Development》2005,25(6):669-670

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提心吊胆的华尔街     

Paul  J.Lim  周仲林 《海外英语》2004,(8):14-15

The war in Iraq, terrorism, rising oil prices-and now the threat of higher interest rates-are all preying on the market. There comes a point in virtually every bull market when  相似文献   

从孟、荀看战国儒家政治文化之演进     

林孝宣 《天津师范大学学报(社会科学版)》2002,(5):6-9

孟子与荀子的政治观从表面上看大多是对立的，但在实际上并不矛盾，他们往往说的不是一个层面上的问题。就其政治大思路而言，二者是一致的，都倡导人治，都是道德主义的，有其“同归而殊途”的内在逻辑。  相似文献   

Examining Teachers' Use of iPads: Comfort Level,Perception, and Use     

Min Liu  Cesar C. Navarrete  Robert Scordino  Jina Kang  Yujung Ko  Mihyun Lim 《Journal of Research on Technology in Education》2016,48(3):159-180

While there is evidence of the growing popularity of iPads and other tablets in K–12 education, little is understood about how teachers use these devices in their instruction. This study examines 342 teachers' comfort level with and perception toward iPad use and any changes that occurred over the implementation year. Using a mixed-methods design, this study found significant differences in comfort level by years of teaching and school levels. Female teachers, teachers with 20 years or less of teaching experience, and elementary school teachers were more positive about their perception toward iPad use than the other groups. High school teachers' perception was the lowest overall. Analyses of teacher interviews revealed affordances, challenges, and diverse ways of how teachers used iPads in their instruction. Implications for practice and research are discussed.  相似文献