• Journal of the Korean Society of Visualization
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• v.8 no.4
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• pp.48-53
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• 2010

Water-uptake through roots, is an essential process of the water flow in plants. Its visualization is very useful for understanding sap flow dynamics at whole plant level. In this study, the tips of Arabidopsis' root hairs were excised and exposed to repeated dehydration and rehydration processes. The water-refilling through individual xylem vessels was visualized using the synchrotron X-ray micro-imaging technique. The high temporal resolution ($2\;{\mu}m$) and beam intensity of the X-ray source allowed to acquisition of consecutive X-ray images of the water-refilling process up to 10 frames/sec. Various flow patterns were observed and the ascending speed of the water-air interfaces was analyzed. The relation between the water-rising height and ascending speed was also analyzed. The present results would provide better alternative for investigating sap flows in roots.

• Journal of the Korean Society of Visualization
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• v.22 no.3
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• pp.78-85
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• 2024

This study explores the effect of gas diffusion layer (GDL) degradation on the performance and water management of polymer electrolyte membrane fuel cells (PEMFCs) through in-situ accelerated stress tests involving humidification/dehumidification cycles. Using synchrotron X-ray imaging, the research reveals that GDL degradation increases water retention and alters water transport behavior, leading to flooding and mass transport losses. The aged GDLs show larger pores and reduced hydrophobicity, impairing water drainage and gas transport. This contributes to performance loss, particularly at higher current densities. The findings highlight the importance of enhancing GDL durability to maintain stable PEMFC performance and meet lifespan targets, particularly in automotive applications requiring long-term reliability under fluctuating conditions.

• Journal of Biomedical Engineering Research
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• v.21 no.5
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• pp.527-535
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• 2000

For a reliable patient set-up verification, better portal films are needed to track relevant features. Simulator films are compared with portal films as a reference image in radiotherapy planning. This shows some possibilities of the use of image information of simulator images for enhancement and restorations of portal images which are very poor in quality compared with the simulator images. This paper present an approach that combine an associative memory, a kind of artificial neural networks with fuzzy image enhancement technique using genetic algorithm which determines the fuzzy region of membership function by the use of maximum entropy principles. A higher portal image quality than conventional technique is achieved.