• The Korean Journal of Food And Nutrition
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• v.28 no.3
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• pp.493-498
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• 2015

The aim of this study is to investigate the changes in the quality characteristics of cheonggukjang made with germinated soybeans, which is produced by the addition of a smoking process. The L value of smoked cheonggukjang made with germinated soybeans (SCGS) was higher than that of non-smoked cheonggukjang made with non-germinated soybeans (NCNS) and non-smoked cheonggukjang made with germinated soybeans (NCGS). The a value of NCNS was the highest, followed by NCGS and SCGS. The b and ${\Delta}T$ values had a similar tendency compared with the L value. The amino acids in NCGS were significantly decreased compared with NCNS, whereas no remarkable difference in amino acid content was observed between NCGS and SCGS. The moisture content of NCGS ($61.9{\pm}0.9%$) was increased by more than 8% compared with that of NCNS ($53.3{\pm}0.7%$). The moisture content of SCGS was significantly decreased compared with NCGS, whereas the moisture content of SCGS was higher than that of NCNS. The pH of SCGS was significantly the highest, followed by NCGS and NCNS. The viscous substance content of NCGS was significantly increased compared with that of NCNS. No remarkable difference in viscous substance content was observed between NCGS and SCGS. The number of aerobic bacteria in SCGS was significantly decreased compared with NCGS. The levels of total isoflavone in NCNS, NCGS, and SCGS were $1,573.9{\pm}62.5$, $1,759.1{\pm}65.8$, $1,738.0{\pm}68.1mg%$, respectively.

• The Korean Journal of Food And Nutrition
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• v.29 no.5
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• pp.628-634
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• 2016

The aim of this study was to determine the changes in fatty acid composition and sensory characteristics of cheonggukjang containing walnuts at 0, 10, 20, or 30%. Amino nitrogen content was decreased with increasing content of walnuts. However, cheonggukjang containing 30% of walnuts met the standard of food sanitation act. Volatile basic nitrogen contents of cheonggukjang containing walnuts was lower than that of cheonggukjang containing no walnut. There was no significant difference in total amino acid content for cheonggukjang containing 0%, 10%, or 20% of walnuts. However, total amino acid content in cheonggukjang containing 30% of walnuts was significantly lower than that in cheonggukjang containing 0%, 10%, or 20% of walnuts. The content of essential amino acid in cheonggukjang containing 30% of walnuts was also significantly lower than that in cheonggukjang containing 0%, 10%, or 20% of walnuts. Saturated fatty acid content was decreased significantly from 16.7% to 3.6% when the content of was increased from 0% to 30%. Total unsaturated fatty acid contents was increased with increasing amounts of walnut added to cheonggukjang. Result of sensory evaluation revealed that the taste and overall quality of cheonggukjang made with 10~20% walnuts were significantly higher compared to those of ordinary cheonggukjang. These results suggest that cheonggukjang made with 10~20% walnuts could be developed as a novel fermented food.

• Proceedings of the SCSK Conference
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• 2003.09b
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• pp.241-242
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• 2003

The effects of N-acetylphytospingosine(NAPS), one of the phytospingosine derivatives, on melanogenesis of B 16F 1 0 mouse melanoma cell lines were investigated. We assessed the effect of NAPS on the depigmentation of B16F10 cells. The melanin content of cells was significantly reduced by NAPS. We examined the inhibitory effect of NAPS on tyrosinase activity using L-dopa as a substrate and the results showed that tyrosinase activity was inhibited in a does-dependent manner. The mRNA level of tyrosinase as well as that of tyrosinase related protein-l (TRP-l) and tyrosinase related protein-2 (TRP-2) genes were not affected by NAPS based on a reverse transcription-polymerase chain reaction (RT-PCR) assay. We also performed a Western blotting analysis using anti-tyrosinase antibody. It showed that there is no change in tyrosinase protein level after treatment of NAPS. These results suggest that the depigmenting mechanism of NAPS in B16F10 melanoma cells involves inhibition of melanosomal tyrosinase activity, rather than the mRNA expression or protein level of tyrosinase.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.4
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• pp.28-35
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• 2021

Infrared (IR) stealth technology to protect aircraft from heat-tracking missiles is a very important factor in the development of military aircraft. In this study, the intensities of signal generation were compared by observing the IR signals generated from the plumes of the engine and identifying them for each measurement angle. To simulate a jet engine applied to an actual aircraft, a small turbojet engine was constructed, the infrared signal characteristics for each wavelength were identified according to the measurement angle, and the total infrared radiance was derived by integrating the signal for each wavelength. Through this study, we intend to present basic data for improving the infrared stealth performance of aircraft.

• Journal of Energy Engineering
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• v.4 no.2
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• pp.297-302
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• 1995

Ignition of a reactive solid in a shape of square corner by a hot surface is studied theoretically. Ignition time and the location of ignition point are determined as a function of dimensionless parameters, with the use of the homogeneous model of ignition. The effect of geometry on the ignition of solid fuel results in the local characteristics: the reaction is initiated in a hot point in depth of the substance. It is shown that ignition time is proportional to the dimensionless initial temperature, whereas for the ignition of the semiinfinite body this dependence was quadratic.

• Proceedings of the KSEEG Conference
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• 2007.04a
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• pp.460-462
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• 2007

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• Journal of radiological science and technology
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• v.41 no.5
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• pp.437-444
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• 2018

Whole-Body counters have been used to evaluate the internal contamination of gamma emitting radionuclides. Among the whole-body counters used in domestic nuclear facilities, Fastscan made by CANBERRA contains 2 NaI(Tl) detectors and is generally used to monitor the primary internal exposure. It has the advantage of achieving MDA even with short time measurements. Accuscan is a bed type, and has good energy resolution because it is composed of HPGe detector. Since the Accuscan with better energy resolution than Fastscan has better able to identify radionuclides, it is used to monitor secondary internal exposure. Some nuclear facilities have only Fastscan. We analyzed statistically whether Fastscan is enough to ensure accuracy and precision comparing with Accuscan. To do this, we prepared a CRM created by the Korea Research Institute of Standards and Science. We also obtained the data of 6 Fastscans and 5 Accuscans in domestic nuclear facilities. As a result of the study, although Fastscan compared with Accuscan is not as accurate as the Accuscan, the precision is statistically same. However, accuracy of Fastscan is in compliance with international standards except low energy range. In terms of accuracy and precision except radionuclides emitting low energy, it is possible to measure radioactivity inside workers even in nuclear facilities where only Fastscan is used.

• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.1148-1155
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• 2010

To suggest a modified shallow foundation design method which can be considered the scale effect of foundation on IGM(intermediate geomaterial) soil layer, the weathered soil layer that is uniformly formed up to 8m(2B) with over 50 N-value is selected and 3 times field loading tests are performed on several sized square-shaped shallow foundations with 30, 75, 150, 240 and 400cm in width respectively. Because the soil modulus of elasticity(Es) calculated by soil investigation and 1st field test(PBT) results showed an underestimated tendency, a modified correlation is required for the reasonable estimation of Es on the weathered soil. Also, the N-value was increased with an increasing in depth. However, the N-values around the test foundations showed the different values even though the foundations on the same level because the test site was arranged by excavation. Therefore, the more detail soil investigations are required for the each test foundations respectively. Since Es based on elasticity theory is determined by the stress distribution shape of the foundation and elasticity modulus of the soil, the scale effect considered pressure-settlement curve can be clearly derived from the correlation on stress distribution shape and the variation of soil elasticity modulus with depth. Therefore, the modified correlation will be suggested to estimate a reasonable Es on the weathered soil, and the scale effect considered shallow foundation design method is also developed based on the elastic theory and field tests in this research.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.4
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• pp.401-410
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• 2014

This paper presents a high-efficiency concurrent dual-band Class-E power amplifier(PA) that is based on a multi-harmonic matching network(MHMN). The proposed MHMN controls the impedance at 1.3 GHz, 2.1 GHz, and their second and third harmonics, respectively, by using transmission lines only rather than switches or lumped components. The dual-band Class-E PA is implemented using Avago ATF-50189 GaAs p-HEMT. The PA exhibits a measured output power of 27.1 dBm and 25.7 dBm, a power gain of 6.1 dB and 4.7 dB, and a drain efficiency of 71.2 % and 60.1 % at 1.3 GHz and 2.1 GHz, respectively.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1303-1305
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• 1998

In order to reduce or avoid oxidation problem at operation the interconnects in SOFCs have so far mostly been made of ceramic material. It has high chemical stability both under cathode and anode condition, relatively thermal expansion coefficient that matchs that of electrolyte material YSZ. But this material shown rather weak in the low oxygen atmosphere and thermal shock, and it has lower mechanical strength than alloys. To avoid these problems one may consider to use metals or alloys as materials for interconnects. Metallic interconnects are advantageous because of their high thermal and electronic conductivities. But it has some problems, Those are high thermal expansion and oxidation at high temperature in air. To solve these problems in the interconnection material in this study, $LaCrO_3$-dispersed Cr alloys for metallic interconnector of SOFC have been investigated as a fuction of $LaCrO_3$ content in the range of 5 to 25 vol.%. The Cr alloy were prepared by mixing Cr and $LaCrO_3$ powders in high-energy ball mill for 48h and by sintering under Ar atmosphere with 5vol.% $H_2$ for 10h at $1500^{\circ}C$. The alloys had a relative density of 95% and above. The Cr alloys in composed of two kind of small $LaCrO_3$ and large Cr particles. As the $LaCrO_3$ content increased, the Cr particle size decreased but the $LaCrO_3$ particle size remained contant. Also the oxidation tests show that the $LaCrO_3$-dispersed Cr is very resistant to oxidation in air. These results means that $LaCrO_3$-dispersed Cr is a useful material for metallic interconnect of planar SOFC.