• Applied Chemistry for Engineering
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• v.26 no.4
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• pp.421-426
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• 2015

Arthrospira platensis (A. platensis) has been used in various fields including dietary supplements as it contains a high protein content and large amounts of unsaturated fatty acids. In addition, it has some pigments such as phycocyanin, myxoxanthophyll and zeaxanthin and thus has been used as a food additive and antioxidant substance. Nano-bubble hydrogen is to dissolve more than the saturation solubility in water by injecting the hydrogen gas in the nano-bubble hydrogen water. The nano-bubbles are known to possess higher antioxidant properties in addition to anticancer effects. In this paper, Arthrospira platensis was cultured in both a normal medium with distilled water and nano-bubble hydrogen water medium and their properties were compared. The cell growth and the content of chlorophyll and carotenoid in the nano-bubble hydrogen water was 15% higher than that of the control. The level of phycocyanin in nano-bubble hydrogen water was also 7% higher than that of the control. However, there were little differences in the lipid content between the nano-bubble and control. To determine the content of the antioxidants, the level of flavonoid and polyphenol were measured. The level of flavonoid in nano-bubble hydrogen water was found to be more than 70% increased when comparing to that of the control, while the level of polyphenol was similar to each other.

• Journal of the Korea Convergence Society
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• v.8 no.12
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• pp.1-7
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• 2017

This study was conducted to investigate changes in ginsenoside by continuously treating fine bubble, which are mainly used for environmental purification, in 2-year-old ginseng. The ginsenoside content and composition of ginseng leaves and roots were analyzed for 4 months (120 days) after application of Fine bubble. As a result of treatment with common water in leaves, only Re of protopanaxatriol was significantly higher and As a result of treatment with fine buble, it was confirmed that protopanaxadiol Rb1, RC, Rb2 and Rd components were also increased. Especially, the increase of Re and Rb1 resulted in an increase of total ginsenoside. The ratio of PD / PT to ginseng was 0.811 in finebubble treated leaves and 1.28 in root. The fine bubble treatment induced the synthesis of ginsenoside from the roots and resulted in a PD / PT ratio of close to 1. Therefore, this study suggests a method of cultivating high quality ginseng using fine bubble water and suggests possibility of using it as a functional food material which can be used with leaves as well as roots.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.35 no.10
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• pp.1089-1095
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• 2011

Numerical simulation is performed for nucleate boiling on a micro-finned surface, which has been widely used to enhance heat transfer, by solving the equations governing the conservation of mass, momentum, and energy in the liquid and vapor phases. The bubble motion is determined by a sharp-interface level-set method, which is modified to include the effect of phase change and to treat the no-slip and contact-angle conditions, as well as the evaporative heat flux from the liquid microlayer on immersed solid surfaces such as micro fins and cavities. The numerical results for bubble formation, growth, and departure on a microstructured surface including fins and cavities show that the bubble behavior during nucleate boiling is significantly influenced by the fin-cavity arrangement and the fin-fin spacing.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.9
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• pp.1239-1246
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• 2000

The objective of this work is to measure space and time resolved wall heat fluxes during nucleate pool boiling of R113/R11 mixtures using a microscale heater array in conjunction with a high speed CCD. The microscale heater array is constructed using VLSI techniques, and consists of 96 serpentine platinum resistance heaters on a transparent quartz substrate. Electronic feedback circuits are used to keep the temperature of each heater at a specified temperature and the variation in heating power required to keep the temperature constant is measured. Heat flux data around an isolated bubble are obtained with triggered CCD images. CCD images are obtained at a rate of 1000frames/second. The heat transfer variation vs. time on the heaters directly around the nucleation site is plotted and correlated with images of the bubble obtainedby using the high speed CCD. For both of the mixture(R11/R113) and pure system(pure R11, pure R113), the wall heat fluxes are presented and compared to find out the qualitative difference between pure and binary mixture nucleate boiling.

• Proceedings of the KSME Conference
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• 2003.04a
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• pp.1491-1498
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• 2003

Droplet evaporation can be used to transfer large amounts of energy since heat is transferred across a thin liquid film. Spreading the drop over a larger area can enhance this heat transfer. One method of accomplishing this is to dissolve gas into the liquid. When the drop strikes the surface, a gas bubble nucleates and can grow and merge within the liquid, resulting in an increase in the droplet diameter. In this study, time and space resolved heat transfer characteristics for a single droplet striking a heated surface were experimentally investigated. The local wall heat flux and temperature measurements were provided by a novel experimental technique in which 96 individually controlled heaters were used to map the heat transfer coefficient contour on the surface. A high-speed digital video camera was used to simultaneously record images of the drop from below. The measurements to date indicate that significantly smaller droplet evaporation times can be achieved. The splat diameter was observed to increase with time just after the initial transient dies out due to the growth of the bubble, in contrast to a monotonically decreasing splat diameter for the case of no bubbles. Bursting of the bubble corresponded to a sudden decrease in droplet heat transfer.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.298-300
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• 2001

Haematococcus pluvialis was cultured autotrophically and mixotrophically for astaxanthin production in bubble column photobioreactors with $CO_2$ and/or acetate supplements. Four different schemes were tested using 5% $CO_2$ balanced with 95% $N_2$ at the aeration rate of 0.1 vvm and supplementation of acetate (l g/L) to the basal medium, MBBM. Average specific growth rates based on cell total volume of each case were 0.138 $day^{-1}$ in control (without $CO_2$ and acetate supplements), 0.125 $day^{-1}$ with only acetate supplementation, 0.315 $day^{-1}$ with only $CO_2$ supplement, 0.304 $day^{-1}$with both $CO_2$ and acetate. The growth rate under $CO_2$ supply was much higher than that without $CO_2$ supply. DCO and DO seemed to be a possible limitation factor. Another interesting observation was the growth rate under $CO_2$ supplement (without acetate) was higher than that under both $CO_2$ and acetate supply. This result is the opposite of the previously reported works. From the result, the existence of acetate may suppress the dark reaction of $CO_2$ fixation or photosynthesis. Conclusively, the growth of H. pluvialis under photoautotrophic condition found to be higher than that under mixotrophic condition.

• Nuclear Engineering and Technology
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• v.38 no.2
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• pp.175-184
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• 2006

Boiling and flashing are driven by the same physics for nucleation, bubble growth, departure etc. An adequate model of boiling has to describe the flashing too. The subject of this paper is to prove this uniqueness of the elementary physics driving the both processes.

• Proceedings of the Korean Society of Life Science Conference
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• 2006.09a
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• pp.111.2-111.2
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• 2006

• Proceedings of the Korean Nuclear Society Conference
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• 1999.05a
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• pp.110-110
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• 1999

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.3
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• pp.419-423
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• 1998

The internal defects in $(CaF_2)$ single crystal were characterized by the observation of optical microscopy, the element analysis and the transmittance analysis. In bubble and negative crystal which are composed to crystal plane of (100) and (111), the spread negative crystal in $(CaF_2)$ crystal gave an effect of low transmittance. The precipitates formed in bubble as internal cavities were analyzed by using WDX. Violet colored-crystal had higher a dislocation density than non-colored crystal, and the atomic ratio between Ca and F changed by poor F ion. In this result, we could determine indirectly that violet color was occurred by poor F ion.