Programmed sample delivery on a pressurized paper     

Joong Ho Shin  Juhwan Park  Seung Hoon Kim  Je-Kyun Park 《Biomicrofluidics》2014,8(5)

This paper reports a method to control the fluid flow in paper-based microfluidic devices simply by pressing over the channel surface of paper, thereby decreasing the pore size and permeability of a non-woven polypropylene sheet. As a result, fluid resistance is increased in the pressed region and causes flow rate to decrease. We characterize the decrease of flow rate with respect to different amounts of pressure applied, and up to 740% decrease in flow velocity was achieved. In addition, we demonstrate flow rate control in a Y-shaped merging paper and sequential delivery of multiple color dyes in a three-branched paper. Furthermore, sequential delivery of multiple fluid samples is performed to demonstrate its application in multi-step colorimetric immunoassay, which shows a 4.3-fold signal increase via enhancement step.  相似文献   

Optofluidic microvalve-on-a-chip with a surface plasmon-enhanced fiber optic microheater     

Hyun-Tae Kim  Hyungdae Bae  Zhijian Zhang  Abisola Kusimo  Miao Yu 《Biomicrofluidics》2014,8(5)

We present an optofluidic microvalve utilizing an embedded, surface plasmon-enhanced fiber optic microheater. The fiber optic microheater is formed by depositing a titanium thin film on the roughened end-face of a silica optical fiber that serves as a waveguide to deliver laser light to the titanium film. The nanoscale roughness at the titanium-silica interface enables strong light absorption enhancement in the titanium film through excitation of localized surface plasmons as well as facilitates bubble nucleation. Our experimental results show that due to the unique design of the fiber optic heater, the threshold laser power required to generate a bubble is greatly reduced and the bubble growth rate is significantly increased. By using the microvalve, stable vapor bubble generation in the microchannel is demonstrated, which does not require complex optical focusing and alignment. The generated vapor bubble is shown to successfully block a liquid flow channel with a size of 125 μm × 125 μm and a flow rate of ∼10 μl/min at ∼120 mW laser power.  相似文献   

The influence of exercise intensity on frontal electroencephalographic asymmetry and self-reported affect     

Woo M  Kim S  Kim J  Petruzzello SJ  Hatfield BD 《Research quarterly for exercise and sport》2010,81(3):349-359

The "feel better" effect of exercise has been well established, but the optimal intensity needed to elicit a positive affective response is controversial. In addition, the mechanisms underlying such a response are unclear To clarify these issues, female undergraduate students were monitored for electroencephalographic (EEG) and self-reported affective responses during the recovery period following rest, low, moderate, and high intensities of treadmill running, each lasting 30 min. Frontal EEG asymmetry and self-reported vigor scores following exercise at all three intensities were significantly elevated compared to those observed following rest. The results suggest that steady-state aerobic exercise bouts executed at varying intensities induce a similar affective response during the recovery period when assessed at both the behavioral and psychophysiological levels.  相似文献   

Depoliticising Politics: Readings of Theresa Hak Kyung Cha's Dictée     

Hyo Kim 《Changing English: An International Journal of English Teaching》2008,15(4):467-475

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Expert systems: They’re here now     

Kim E. Ruyle 《TechTrends》1989,34(1):41-43

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Reappraisals of the Academy Movement     

Kim Tolley  Nancy Beadie 《History of education quarterly》2001,41(2):216-224

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The Rise of the Academies: Continuity or Change?     

Kim Tolley 《History of education quarterly》2001,41(2):225-239

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Universities and the humanities,then and now     

SunHee Kim Gertz 《Journal of Further & Higher Education》2017,41(6):844-856

Over the centuries, universities have functioned as gatekeepers and treasurers of received knowledge, while concomitantly furthering innovative contributions to society. Yet, when cultivating research ‘silos’, universities encourage scholars to explore in seeming isolation. Out of such tensions, universities have supported, and will continue to pursue, different kinds of, and approaches to, furthering knowledge and creativity. In the past, the humanities had been central to this mission. More recently, however, the efficient and global acceleration of consumer-oriented ‘knowledge production and consumption’ seems to form a critical factor upsetting the centrality of the humanities in university cultures. In this context, exploring the academic communities of the late middle ages proves to be a useful exercise. Forged in strong relationships with ecclesiastical and secular powers, mediaeval universities nonetheless share critical concerns with today’s academic institutions; thus, they too were constrained by the need to attract and exact excellence, to navigate relationships with their immediate environs, and to train professionals, who could ensure continuity in academic communities, the church, and the imperial courts. In other words, mediaeval universities also experienced polarising tensions that reveal consonances between then and now and that can gloss today’s acceleration driving the consumer model of knowledge production and consumption, while also encouraging scholars to form more explicit links to external constituencies.  相似文献   

Vygotsky’s sociocultural theory in the context of globalization     

Simon Marginson  Thi Kim Anh Dang 《Asia Pacific Journal of Education》2017,37(1):116-129

The article reviews the social-educational theorization of the early Soviet psychologist L. S. Vygotsky (1896–1934) in the light of the impact of communicative globalization in educational practice. Vygotsky proposed four “genetic domains” for investigating higher cognitive processes: the phylogenetic (humans undergoing natural evolution), the cultural-historical (social activity of humans), the ontogenetic (individual lifespan), and the microgenetic (immediate events). Vygotskian sociocultural theory is widely used in educational research, especially Vygotsky’s notion of mediated development via tools and signs. Since Vygotsky, communicative globalization has transformed educational potentials. Nevertheless, provided adjustments are made to Vygotsky’s genetic method to incorporate time-space compression, the mutual presence of the genetic domains, and the glonacal heuristic, Vygotskian theory continues to be useful in socially-situated investigations of educational development and transformation, and opens another way into the global, for example investigation of the role of global mediation in learning.  相似文献   

Film scenes in interdisciplinary education: teaching the Internet of Things*     

Young-mee Hwang  Kwang-sun Kim  Tami Im 《Educational Media International》2017,54(2):83-98

The Internet of Things (IoT) is gaining importance in education owing to its rapid development. This study addresses the importance of interdisciplinary education between technology and the humanities. The use of films as a teaching resource is suitable for interdisciplinary education because films represent creative forecasts and predictions on future human society, helping the public realize what could occur in the future. By utilizing films in instruction, students can be trained to understand the three key functions of IoT and acquire the ability to develop creative applications of IoT. An IoT teaching model using the films Minority Report (2002), Big Hero 6 (2014), Iron Man 3 (2013), Her (2013), and Transcendence (2014), all of which depict various applications of IoT that could be helpful in the teaching of the functions and concepts of IoT, is suggested; an interdisciplinary class is carried out for 15 weeks following the model. The effectiveness of the class is measured using quantitative analysis, qualitative analysis, and reflection journals. The findings show that students developed interdisciplinary capacity through education using films.  相似文献