• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.3
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• pp.215-220
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• 2001

Biochemical responses of rice to the flooding stress with different water turbidities and flooding time were evaluated. About 20% decrease of soluble protein was occurred with flooding stress. The decreasing rate was higher as flooding time and higher turbidity increased. Especially, dramatic decrease of soluble protein content was observed after 36 hrs of flooding. No protein subunit change was found before and after flooding. However, subunit product of 53 Kd increased from the beginning of flooding and subunit of 28 Kd was increased 48 hrs and 54 hrs after flooding. Lipid peroxidation increased about 150% by flooding. There was no significant difference in lipid peroxidation between clear and sub-muddy water, However, the lipid peroxidation was increased up to 180% at 60hrs of flooding. The malondialdehyde content (MDA) was higher in muddy water at the beginning of flooding and increased about 190-200% 36 hrs after flooding. Catalase activity increased with increasing turbidity and flooding time. Forty eight hours of flooding time provided a criteria for dramatic increase of catalase activity. In general, increase of saturated fatty acids and decrease of unsaturated fatty acids occurred with flooding treatment. Among unsaturated fatty acids, monounsaturated increased and polyunsaturated decreased. Double bond index(DBI) decreased as flooding time was extended and turbidity increased.

• Culinary science and hospitality research
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• v.18 no.4
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• pp.209-221
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• 2012

The purpose of this study is to apply molecular gastronomy and its spherification methodology to persimmon desserts. We prepared persimmon calcium alginate beads and investigated physical and sensory characteristics of beads according to the different concentration of calcium chloride(0.5, 0.75, 1.0%) and reaction time(2, 4, 6, 8, 10 min). Lightness and yellowness were decreased significantly as both calcium chloride concentration and reaction time increased. However, redness was increased significantly as the concentration of calcium chloride and reaction time increased. Hardness, springiness, chewiness, cohesiveness, and resilience except for adhesiveness tended to increase as the concentration of calcium chloride and reaction time increased. The thickness of beads also increased as the concentration of calcium chloride and reaction time increased. Quantitative descriptive analysis showed that voluminosity, springiness, hardness, chewiness, and residue tended to increase as the concentration of calcium chloride increased. Overall acceptability reached a peak at the persimmon bead containing 0.5% calcium chloride. The result of this study showed that the concentration of calcium chloride and reaction time influenced the overall characteristics of calcium alginate beads.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.155-156
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• 2007

AISI316L강에 저온 프라즈마 침탄과 저온 프라즈마 질화를 연속적으로 실시하여 표면경도와 내식성을 동시에 증가시키는 처리법에서 질화처리 시 처리시간 및 온도에 따른 표면특성변화를 조사하였다. 모든 시편의 표면에 N에 의해 확장된 오스테나이트(${\gamma}_N$)가 형성되었으며, 형성된 ${\gamma}_N$로 인하여 표면경도가 약 $3{\sim}4$배 증가하였다. 처리시간과 온도가 증가함에 따라 ${\gamma}_N$층의 두께와 표면의 N농도가 증가 하였다. 표면처리한 모든 시편은 표면의 N의 영향으로 내식성이 증가 하였다.

• Journal of the Korean GEO-environmental Society
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• v.15 no.8
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• pp.39-44
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• 2014

Effects of operating parameters on the breakthrough properties of Pb(II) by $Mn_3O_4$ coated activated carbon prepared by supercritical technique were investigated through fixed-bed column experiments. The mass transfer zone and equilibrium adsorption capacity were enhanced about 2.8 times for Pb(II) by $Mn_3O_4$ coating onto activated carbon. Increase of bed height enhanced the residence time of Pb(II) in adsorption zone, giving the higher breakthrough time, mass transfer zone and equilibrium adsorption capacity. Increase of flow rate reduced the residence time and diffusion of Pb(II) in adsorption zone, therefore decreased the equilibrium adsorption capacity. The higher inlet concentration of Pb(II) decreased the breakthrough time and mass transfer zone through the promotion of Pb(II) transfer onto adsorbent.

• Korean journal of food and cookery science
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• v.16 no.2
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• pp.128-134
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• 2000

Cysteine, a thiol group-containing reducing agent which is known to relax the strain and increase the viscosity of dough, was added to Korean and imported wheat flour noodles to investigate the effect on the properties of raw, dried, and cooked noodles and to determine the optimum cooking time and amount to improve the color of noodles. Addition of cysteine up to 1% of flour (8.25 mmole/100 g flour) was not effective in increasing the brightness of raw and dried noodles and in changing the water activity of dried noodle. However, cysteine improved the brightness of cooked noodle made of both Korean and imported wheat flours. Also, there were notable differences in cooking and sensory properties of cysteine-added cooked noodles such as less firm and stickier texture due to the extraction of organic compounds into broth. When the noodles were cooked for their optimum cooking time, no difference was noticed in the texture and overall preference regardless of the addition of cysteine. Overall, the addition of 1 % cysteine increased the brightness of cooked noodles and reduced the cooking time.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.332-332
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• 2012

분자선 에피탁시(molecular beam epitaxy)를 이용하여 GaAs 기판에 성장한 InAs 양자점(QDs: quantum dots)은 성장 온도, 압력, As/In의 공급비 등의 성장 조건에 따라 다른 변수(parameter)를 갖는다. 따라서 성장변수에 따라 양자점의 모양과 크기, 밀도가 달라져 균일한 양자점 형성에 어려움이 있어 많은 연구가 진행되고 있다. 예를 들면 In-interruption 법으로 성장한 양자점의 특성이 S-K mode (Stranski-Krastanov mode)로 성장한 양자점에 비해 광학적 특성이 향상되었다. 본 연구에서는 In pre-deposition (IPD) 법으로 성장한 InAs/GaAs 양자점의 광학적 특성을 PL(photoluminescence)와 TRPL (time-resolved PL)을 이용하여 분석하였다. InAs QDs 시료들은 In과 As 공급시간을 각각 1초와 19초 (QD1), 2초와 18초 (QD2), 3초와 17초 (QD3)로 조절하여 성장하였으며, In이 공급되는 시간 동안 As shutter를 차단하여 As 공급을 중단하였다. In과 As의 차단 없이 S-K mode로 성장한 시료를 기준시료로 사용하였다 (QD0). AFM (atomic force microscope) 측정결과, In 공급시간이 1초에서 2초로 증가할 때, 양자점의 밀도와 종횡비(aspect ratio)가 증가하였고, 양자점의 균일도가 증가하였다. 그러나 QD3 시료는 QD1 시료에 비해 밀도와 종횡비, 균일도가 감소하였다. 10 K에서 PL 피크는 In 공급 시간이 증가할 때, 970 nm에서 1020 nm로 적색편이 하였고 반치폭 (FWHM: full width at half maximum)은 75 meV에서 85 meV로 증가하였다. QD2 시료의 PL 피크 에너지가 가장 낮았고, 가장 강한 PL 세기를 보였다. IPD 시간이 증가함에 따라 PL 피크에서 측정한 PL 소멸은 점차 빨라졌다. IPD 기법으로 성장한 양자점의 빠른 PL 소멸은 양자점 밀도와 종횡비 향상에 의한 파동함수 중첩의 증가와 구속 에너지 증가에 의한 것으로 설명된다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.591-595
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• 1998

Browning chracteristics were investigated for Chicory roots(Cichorium intybus L.) when roasted at different conditions of 120 to $180^{\circ}C$ in temperature and 10 to 40min in time. The soluble solid of water extracts obtained from roasted Chicory roots increased slowly with increasing roasting temperature and time, but it decreased above $160^{\circ}C$. The contents of reducing sugar and amino-type nitrogen in aqueous extracts obtained from roasted Chicory roots decreased rapidly with increasing the roasting time and temperature. Browning color intensity in aqueous extracts of roasted Chicory roots increased with increasing the roasting temperature and time, Hunter's color L and b values of Chicory powder decreased with increasing the roasting temperature and time, while Hunter's color a and ${\Delta}E$ values continuously increased with increasing the roasting temperature and time.

• Korean Journal of Food Science and Technology
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• v.34 no.6
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• pp.1013-1017
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• 2002

Functional activities of Flammulina velutipes extract including electron donating ability, nitrite-scavenging effect, and tyrosinase inhibition activity was examined. Extraction were carried out by microwave-assisted extraction (MAE) under different conditions including solvent and microwave power. Tyrosinase inhibition activity and nitrite-scavenging effect increased as microwave power increased during extraction. Total phenol content and electron-donating ability reached maximum at the microwave power of 90 W. Total polyphenol content and electron-donating ability increased as extraction time extended up to 15 min, with the highest tyrosinase inhibition obtained after 5 min extraction. Significantly higher tyrosinase inhibition activity was found in 99% ethanol extract, whereas greater nitrite-scavenging effect was observed in the water extract. The maximum nitrite-scavenging effect was found at pH 1.2 and decreased as pH increased.

• Journal of Korea Foundry Society
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• v.41 no.4
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• pp.331-341
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• 2021

The effects of austempering temperature, austenitizing temperature and time, added copper content and prior heat-treatment on the processing window of 3.6wt%C-2.5wt%Si ductile cast iron during austempering. The maximum processing window was obtained at 350℃ of austempering temperature. The processing window was increased with increased austenitizing temperature from 850 to 900℃; however, it decreased at 950℃. The processing window was increased with increased austenitizing time from 0.5 to 2 hours and rather decreased for 4 hours. The optimum condition of austenitizing was obained at 900℃ for 2 hours. The processing window was increased with copper content added in the range of 0.0~0.8wt%. The processing window was increased by prior normalizing heat-treatment and decreased by prior annealing in comparison with that for the as-cast state,

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.355-372
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• 2004

In vitro experiments were conducted to determine the formation of fatty acid soaps (FAS) and neutral detergent fiber (NDF) disappearance rate. The substrates were a basal alfalfa hay containing 1) no oil, 2) 10% soybean oil, 3) 10% com oil, on a weight basis. All the substrates were incubated in triplicate for 0, 3, 6, 12, 24 and 48h in each experiment. After the incubation in the first experiment serum bottles (6oml) were analyzed for nonesterified, esterifed and fatty acid soaps contents. The serum bottles (120mI) from the second experiment were analyzed for pH, $NH_3-N$ and VFA concentration, and dry matter and NDF disappearance rate. pH decreased and the concentration of NH3-N increased significantly with longer incubation time (P<0.0001). The disappearance rates of dry matter and NDF significantly varied with feed, incubation time and oils (P<0.05). The molar concentration of total VFA increased and proportion of acetate significantly decreased with incubation time (P<0.0001), but the proportion of propionate significantly increased with longer incubation time (P<0.0001). Addition of oils to diet lowered the ratio of acetate:propionate (P<0.05). The esterified fatty acids (EFA) decreased with increasing incubation time (P<0.0001), and nonesterified fatty acids (NEFA) increased due to lipolysis of EFA, NEFA then reacted with cations to increase formation of FAS. The formation of FAS increased significantly at 48h of incubation time (P<0.0001). Especially, formation of stearic acid soaps was 27.5 and 32.5 folds with soybean oil and com oil supplements, respectively, by 48h of incubation time (P<0.0001). Alfalfa hay had higher cation contents, particularly Ca, which react with NEFA and FAS can be formed with longer incubation time. Saturated fatty acids had a higher proportion of FAS than did unsaturated fatty acids, suggesting that the former may react more extensively with cations. FAS contents increased with increasing chain length of the fatty acids. Since added vegetable oils fonned FAS, it might decrease negative effects on in vitro fermentation characteristics and NDF disappearance rate.