• Journal of Chitin and Chitosan
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• v.23 no.4
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• pp.234-243
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• 2018

In this study, the physicochemical properties of freeze dried (FD) and spray dried powders (SD-MD10, SD-MD20, SD-CD10, SD-CD20) from green coffee bean extract were investigated. Yields were 91.46% for FD powder and 71.63~87.98% for SD powders, respectively. The moisture content of SD powders (1.39~1.86%) was lower than that of FD powder (3.19%). L, a and b value of SD powders were higher than of FD powder. The particle size of the FD powder ($147.67{\mu}m$) was higher than that of the SD powders ($54.23{\sim}66.07{\mu}m$). The water absorption index of the SD powders (0.51-0.59) were lower than that of the FD powder (0.72). The water solubility index of the SD powders, 77.26-90.07%, was higher than that of the FD powder (70.07%). The total phenolic and flavonoid contents of SD-CD10 were 20.67 g/100 g and 8.92 g/100 g, respectively. The chlorogenic acid content of SD-CD10 (12.04 g/100 g) was higher than other SD powders. The DPPH and superoxide radical scavenging activities of SD-CD10 at $1,000{\mu}g/mL$ were 88.02% and 86.89%, respectively. The SD-CD10 was better than other SD powders on protective effects against oxidative stress in L-132 cells (87.33%). In conclusion, we provided experimental evidence that spray-dried powder of green coffee bean extracts have potential as functional food materials.

• Journal of the Korean Wood Science and Technology
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• v.45 no.3
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• pp.288-296
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• 2017

In this study, the effect of spray-drying conditions and surfactant addition on the spray-drying yield, morphological characterization, size distribution and re-dispersity in water of spray-dried lignocellulose nanofibril (LCNF) were investigated. The freeze-dried LCNF after solvent exchange had linear fiber morphology with a diameter of 70-300 nm, and the spray-dried LCNF showed rod-like particle morphology. The spray-drying yield and particle size of spary-dried LCNF at $140^{\circ}C$ was highest and smallest, respectively. As LCNF concentration and blowing rate decreased and increased, respectively, the spray-drying yield and particle size were increased. The highest spray-drying yield was found at distearyl dimethyl ammonium chloride (DDAC) addition of 10 phr at $140^{\circ}C$. As the particle size decreased and the DDAC content increased, filtration time of spray-dried LCNF in water was decreased and increased, respectively.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.05a
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• pp.217-220
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• 2002

할론 등 CFC 계통의 소화약제는 환경오염물질을 내포하며, 지구온난화지수와 오존파괴지수 등이 높아 전세계적으로 그 사용이 중단되고 있다 또한, IMO의 SOLAS Chapter II-2에서는 소화설비에 대한 규정으로 할론소화장치의 새로운 설치를 금지하고 있으며, 2002년 7월 1일 이전에 건조된 2,000톤 이상의 현존 여객선은 기관실 전체를 방호하는 고정식 수계국소방출소화설비를 설치하여야 한다고 규정하고 있다. 이에 대체소화기술의 하나로 관심을 끌며 연구되기 시작한 소화방법이 미세물분무노즐을 이용한 소화설비이다.(중략)

• Journal of Korean Institute of Fire Science & Engineering
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• v.1 no.2
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• pp.6-19
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• 2000

• Fire Protection Technology
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• s.20
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• pp.33-41
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• 1996

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.11-14
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• 2009

The implementation of gelled propellants systems offers high performance, thrust-control, energy management of propulsion, storability, and high density impulse of solid propulsion. Present study focused on the spray behavior of liquid sheets formed by impinging jets of non-Newtonian liquids which are mixed by Carbopol 941 0.5%wt. The results are then compared with experiments conducted on spray images formed by impinging jets concerning with air-blast effect at center orifice. When gel propellants are injected by doublet impinging jets at low pressure, closed rim pattern shape appeared. As increasing air mass flow rate(decreasing GLR), spray breakup and atomization phenomenon better improved and spray structure instabilities for the effect of air-blast are also increased.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.57-60
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• 2011

The spray characteristics according to the recess length of the GCSC injector and the change of momentum flux ratio(MFR) of the gas and the liquid have been examined through high pressure cold flow test using a high pressure chamber. The liquid in this experiment was water, and the gas was nitrogen. The spray images were taken by a back-lit strobe imaging technique. Results showed that the spray was a wide hollow cone at the lower MFR(liquid velocity was fixed) and the spray became a narrow solid cone as the MFR was increased. And the injector with short recess length produced a narrow solid cone at the higher MFR.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.27 no.3
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• pp.367-373
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• 2003

The present study investigates the fire suppression characteristics using a water mist fire suppression system. The fire extinguishing times are measured for various fire sources, fuel types, and different total flooding rates of water mist. Pool fire with hydrocabon fuel is successfully extinguished within a minute under the operating conditions of the water mist system. Two different regimes of the smoke layer cooling are observed, such as rapid and slow cooling processes. The regimes are divided by threshold time which is calculated with auto-correlation function. The threshold time for the initial cooling decreases with increasing water flow-rates and fire sources. These initial cooling effects play an important role in preventing the occurance of flashover fire by the initial fire suppression.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.34 no.11
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• pp.999-1004
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• 2010

Recently, many technologies have been developed in order to satisfy stringent emission regulations. However, in the case of diesel engines, the stringent emission regulations with respect to NOx and PM have not yet been satisfied. A dramatic reduction in the NOx and PM emissions could be achieved by using after-treatment systems such as lean NOx trap (LNT) and urea-SCR systems. However, the high temperature in the exhaust pipe affects the spray behavior of the secondary injector, which is used for supplying the Urea-SCR. Because of this high temperature, it is difficult to achieve uniform distribution of the reducing agent in the manifold. In this paper, the characteristics of a urea-SCR injector used for injecting in the exhaust pipe are presented. The purpose of this study was to investigate the spray characteristics of the injector, such as the spray angle, injection quantity, and SMD. In addition, laser diagnostics and high-speed-camera images were used to analyze the injector spray characteristics and to present a distribution of reduction in the transparent manifold.

• Food Science and Preservation
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• v.23 no.5
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• pp.654-659
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• 2016

This study was designed to compare the quality characteristics of spray-dried (SD) and freeze-dried (FD) Pueraria thunbergiana extracts powder hot water extracts. Quality characteristics of the SD and FD powder including moisture content, color value, water absorption index, water solubility index, dynamic angle and antioxidant activities were evaluated. The moisture content of SD powder (1.50%) was lower than that of FD powder (2.92%). $L^*$ and $b^*$ values of SD powder was lower than of FD powder. The water absorption index was higher in FD powder (1.40) and water solubility index in SD powder (94.10%) was higher than that FD powder (90.69%). Dynamic angle of SD powder ($36.46^{\circ}$) was higher than that of FD powder ($33.30^{\circ}$). The DPPH radical scavenging activities of 5 mg/mL solution of SD powder and FD powder were 85.38 mg/mL, 59.38 mg/mL, respectively. And, the same trend was observed for the ABTS radical scavenging activities of the drying powder as that observed for their DPPH radical scavenging activities. There were relatively higher contents of phenolic compounds in SD powders than in FD powders. In conclusion, spray-dried Pueraria thunbergiana extracts showed the high WSI, polyphenol, DPPH and ABTS radical scavenging activities and low moisture content and dynamic angle than freeze dried powder.