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91.
92.
The purpose of this paper is to compute the Hankel transform Fn(y) of order n of a function f(x) and its inverse transform using rationalized Haar wavelets. The integrand is replaced by its wavelet decomposition. Thus representing Fn(y) as a Fourier-Bessel series with coefficients depending strongly on the local behavior of the function , thereby getting an efficient algorithm for their numerical evaluation. Numerical evaluations of test functions with known analytical Hankel transforms illustrate the proposed algorithm. 相似文献
93.
Gergely Simon Caroline Busch Marco A. B. Andrade Julien Reboud Jonathan M. Cooper Marc P. Y. Desmulliez Mathis O. Riehle Anne L. Bernassau 《Biomicrofluidics》2021,15(1)
Separation and sorting of biological entities (viruses, bacteria, and cells) is a critical step in any microfluidic lab-on-a-chip device. Acoustofluidics platforms have demonstrated their ability to use physical characteristics of cells to perform label-free separation. Bandpass-type sorting methods of medium-sized entities from a mixture have been presented using acoustic techniques; however, they require multiple transducers, lack support for various target populations, can be sensitive to flow variations, or have not been verified for continuous flow sorting of biological cells. To our knowledge, this paper presents the first acoustic bandpass method that overcomes all these limitations and presents an inherently reconfigurable technique with a single transducer pair for stable continuous flow sorting of blood cells. The sorting method is first demonstrated for polystyrene particles of sizes 6, 10, and 14.5 μm in diameter with measured purity and efficiency coefficients above 75 ± 6% and 85 ± 9%, respectively. The sorting strategy was further validated in the separation of red blood cells from white blood cells and 1 μm polystyrene particles with 78 ± 8% efficiency and 74 ± 6% purity, respectively, at a flow rate of at least 1 μl/min, enabling to process finger prick blood samples within minutes. 相似文献
94.
Size-dependent trajectories of DNA macromolecules due to insulative dielectrophoresis in submicrometer-deep fluidic channels 总被引:1,自引:0,他引:1
Gea O. F. Parikesit Anton P. Markesteijn Oana M. Piciu Andre Bossche Jerry Westerweel Ian T. Young Yuval Garini 《Biomicrofluidics》2008,2(2)
In this paper, we demonstrate for the first time that insulative dielectrophoresis can induce size-dependent trajectories of DNA macromolecules. We experimentally use λ (48.5 kbp) and T4GT7 (165.6 kbp) DNA molecules flowing continuously around a sharp corner inside fluidic channels with a depth of 0.4 μm. Numerical simulation of the electrokinetic force distribution inside the channels is in qualitative agreement with our experimentally observed trajectories. We discuss a possible physical mechanism for the DNA polarization and dielectrophoresis inside confining channels, based on the observed dielectrophoresis responses due to different DNA sizes and various electric fields applied between the inlet and the outlet. The proposed physical mechanism indicates that further extensive investigations, both theoretically and experimentally, would be very useful to better elucidate the forces involved at DNA dielectrophoresis. When applied for size-based sorting of DNA molecules, our sorting method offers two major advantages compared to earlier attempts with insulative dielectrophoresis: Its continuous operation allows for high-throughput analysis, and it only requires electric field strengths as low as ∼10 V∕cm. 相似文献
95.
Morgan Chitiyo Plaxedes Makweche‐Chitiyo Meungguk Park Lawrence K Ametepee Jonathan Chitiyo 《Journal of Research in Special Educational Needs》2011,11(3):171-177
Students who engage in challenging behaviour compromise the fundamental ability of schools to educate children. Consequently, teachers face the daunting task of designing effective strategies to promote positive educational outcomes for their students. Since the 1997 Individuals with Disabilities Education Act amendments, the use of positive behaviour supports (PBS) to address the behavioural needs of children challenged by disabilities has expanded. There is evidence to support the utility of PBS in reducing challenging behaviour among students. However, successful schools are also gauged by the academic achievement of their students. Hence, it is important to examine the extent to which behavioural outcomes are related to academic outcomes. The purpose of this paper is to examine the extent to which PBS interventions aimed at reducing challenging behaviour result in corresponding improvement in academic achievement. A meta‐analysis of extant research indicated a positive correlation of 0.40 between improvement in problem behaviour and academic achievement. A video abstract of this article can be viewed at: http://youtu.be/c9OUU0GkGrw . 相似文献
96.
Research shows teacher collaborative learning to be a powerful vehicle to mobilise teacher instructional change and pedagogical
practices, and to improve student achievement. For such undertakings to have positive impact, understanding the visible features
of collaborative structures may not be sufficient to ensure sustainable practice. Instead, there is a need to identify underlying
pathways that provide for successful instructional improvement. The purpose of this qualitative study is to obtain deeper
insights into teacher outcomes arising from this practice and to identify aspects of the lesson study structure and processes
that afford such opportunities. Three subject groups consisting of ten teachers from a Singapore high school participated
in this study. Implications on staff development programs will be discussed in the light of these findings. 相似文献
97.
This study used eye-tracking methodology to assess audiovisual speech perception in 26 children ranging in age from 5 to 15 years, half with autism spectrum disorders (ASD) and half with typical development. Given the characteristic reduction in gaze to the faces of others in children with ASD, it was hypothesized that they would show reduced influence of visual information on heard speech. Responses were compared on a set of auditory, visual, and audiovisual speech perception tasks. Even when fixated on the face of the speaker, children with ASD were less visually influenced than typical development controls. This indicates fundamental differences in the processing of audiovisual speech in children with ASD, which may contribute to their language and communication impairments. 相似文献
98.
Richard O. Welsh 《Journal of Education for Students Placed at Risk》2018,23(1-2):70-92
ABSTRACTMobile students and absent students are important subsets of at-risk students in schools and districts nationwide. As such, student mobility and school absenteeism are two challenges in K-12 education with significant policy and equity implications. Although both issues are at the nexus of schooling and society and there is an apparent overlap in the attributes of these student subgroups, school absenteeism and student mobility are often discussed in separate conversations. This article connects the two disparate literatures in hopes of forging stronger ties that may benefit policymakers, researchers, educators, and students. The limited empirical evidence is mixed but suggests that school absenteeism and student mobility are correlated and absenteeism plays a small mediating role in the relationship between student mobility and student outcomes. The reasons underlying student mobility and student absenteeism are interrelated but not all reasons are common. The overlapping causes of student mobility and chronic absenteeism indicate that economic and social circumstances are important underlying factors. In particular, poverty is a key shared reason for missing or switching schools. Although both phenomena contribute to disparities in educational opportunities, experiences, and outcomes, this study posits that changing schools and missing school provide instructive examples of how inequality in society may be reproduced in districts and schools. Recommendations to address both phenomena and directions for future research are discussed. 相似文献
99.
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