• Journal of the Korean Applied Science and Technology
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• v.29 no.1
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• pp.141-148
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• 2012

In this study, the composite coating materials with improved thermal insulation property were prepared by incorporating the hydrophobic silica aerogel. The surface modification of silica aerogel was performed to obtain UV curable urethane acrylate hybrid coating sols with good compatibility by using surfactant(Brij 56). The polycarbonate substrates were coated by the prepared composites and cured under UV radiation. The incorporation of aerogel with only 10 vol% of content resulted in remarkable improvement by about 28% in the thermal insulation property of the coated film, as compared with substrate. In addition, increasing aerogel content was found to give minor effect on the variation of optical transparency, adhesion, and surface hardness of the coated film.

• Journal of Environmental Science International
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• v.6 no.2
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• pp.95-106
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• 1997

The characteristics on the transtion probabilities and periodicity for the daily precipitation occurrence in Korean peninsula are investigated by applying the Markov chain properties to daily precipitation occurrence. In order to examine the responses of Markov Chain properties to the applied period and their magnitudes, three cases (Case A: 1956~ 1985 at 14 stations, Case B: 1965~ 1994 at 14 stations, and Case C: 1985~ 1994 at 63 stations) are considered In this study. The transition probabilities from wet day to wet day for all cases are about 0.50 and in summer, especially July, are higher. In addition, considering them in each station we can find that they are the highest at Ullung-do and lowest at Inchon for all cases. The annual equilibrium probabilities of a wet day appear 0.31 In Case A, 0.30 Case B, and 0. 29 Case C, respectively. This may explain that as the data-period used becomes shorter, the higher the equilibrium probability is. The seasonal distributions of equilibrium probabilities are appeared the lowest(0.23~0.28) in winter and the highest(more than 0.39) in spring and monthly in .truly and in October, repectively. The annual mean wet duration for all cases is 2.04 days in Case A, 1.99 Case B, and 1.89 Case C, repectively. The weather cycle obtained from the annual mean wet and dry duration is 6.54~6.59 days, which are closely associated with the movement of synoptic systems. And the statistical tests show that the transitions of daily precipitation occurrence for all cases may have two-state first Markov chain property, being the stationarity in time and heterogeneity in space.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.2
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• pp.99-105
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• 2022

As the chip size gets smaller, the width of the electrode line is also fine, and the density of interconnections is increasing. As a result, RC delay is becoming a problem due to the difference in resistance between the capacitor layer and the electrical conductivity layer. To solve this problem, the development of electrodes with high electrical conductivity and dielectric materials with low dielectric constant is required. In this study, we developed low dielectric ink by mixing commercial PSR which protect PCB's circuits from external factors and PI with excellent thermal property and low-k characteristics. As a result, the ink mixture of PSR and PI 10:3 showed the best results, with a dielectric constant of about 2.6 and 2.37 at 20 GHz and 28 GHz, respectively, and dielectric dissipation was measured at about 0.022 and 0.016. In order to verify the applicability of future applications, various line-width transmission lines produced on Teflon were evaluated, and as a result, the loss of transmission lines using low dielectric ink mixed with PI was 0.12 dB less on average in S21 than when only PSR was used.

• Journal of Mushroom
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• v.15 no.4
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• pp.190-194
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• 2017

Oyster mushrooms are one of the most popular edible mushrooms in Korea. The 'Santari' cultivar bred in this study, which belongs to the species Pleurotus pulmonarius, is a new oyster mushroom cultivar for bottle culture. It was bred by mating monokaryons isolated from 'GMPO20404' and 'Hosan'. The optimum temperature for 'Santari' mycelial growth was $26-29^{\circ}C$ on PDA medium, and the temperatures for primordium formation and for growth of the fruit body on sawdust medium were $22^{\circ}C$ and $20^{\circ}C$, respectively. It took 34 days to complete the spawn run, 3 days to form primordia, and 3 days to finish fruit body growth in the bottle culture. The fruit body pilei were round in shape and brownish, whereas the stipes were long, thick, and white. The yield per bottle of 'Santari' was 172 g/1,100 mL, which was 43% higher than that of the reference cultivar ('Hosan'). The springiness, cohesiveness, gumminess, and brittleness of the stipe tissue were 87%, 82%, 193 g, and 16 kg, respectively. These physical property values of 'Santari' were lower than those of the control cultivar, except for the cohesiveness.

• Journal of the Korean Applied Science and Technology
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• v.36 no.4
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• pp.1096-1107
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• 2019

This study on the physicochemical property of physiological activity substance in mung bean (Phaseolus aureus L.) was performed for the use as an functional food materialization. The proximate composition in the vacuum freeze dried mung bean was carbohydrate 57.20±0.29%, crude protein 26.40±0.69%, moisture 9.90±0.16%, crude ash 3.54±0.43%, and crude fat 2.96±0.26%, respectively. The vitamin content of mung bean was vitamin B₅ 0.62±0.013 mg/100 g, vitamin E 0.17±0.001 mg/100 g, vitamin B₁ 0.13±0.016 mg/100 g, and β-carotene 87.37±0.754 ㎍ RE/100 g, respectively. The mineral content of mung bean was potassium (K) 12,428.55±147.55 mg kg^-1, magnesium (Mg) 2,053.32±14.13 mg kg^-1, calcium (Ca) 1,966.40±14.53 mg kg^-1, sodium (Na) 1,063.99±7.75 mg kg^-1, iron (Fe) 63.77±0.98 mg kg^-1, and manganese (Mn) 14.67±0.22 mg kg^-1. The compositions of fatty acid were saturated fatty acid 29.23±0.03%, monoenes 20.30±0.04%, and polyenes 50.46±0.06%. Protein bound amino acid content of mung bean was 21.75±0.24 g%. And major amino acids were glutamic acid 3.93±0.03 g%, aspartic acid 2.68±0.03 g%, respectively. The composition of free amino acid of mung bean was 336.77±8.66 mg%, and major free amino acids were arginine, glutamic acid, asparagine, and aspartic acid. As a results of these experiment, Mung bean could be used a natural resouce and functional biohealth food substance.

• Korean journal of food and cookery science
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• v.29 no.5
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• pp.479-488
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• 2013

This study is to examine nutrients in the persimmon peel develop processed products and analyze their quality properties. The persimmon peel powder was rich in nutrients with 4.35% of moisture, 3.01% of protein, 1.02% of lipid, 2.02% of ash and $5.7^{\circ}Brix$ of Sugar concentration as well as 82.5 mg% of total carotenoid. As far as quality properties of Sulgidduk were concerned when the 5% addition persimmon peel resulted in the highest level of watery content and the more colors were added the lower the L value became and the higher a and b values. As the result of measurements using a texture analyzer, hardness, adhesiveness, cohesiveness, springiness and chewiness property decreased flexibility increased. The sensory test results revealed that the 3% added persimmon peel Sulgidduk was the best.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.1
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• pp.38-43
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• 2013

In this study we aims to examine the effects of $Co_3O_4$ and NiO doping on the defects and electrical properties in ZnO-$Bi_2O_3-Sb_2O_3$ (Sb/Bi=0.5) varistors. It seemed to form ${Zn_i}^{{\cdot}{\cdot}}$(0.20 eV) and ${V_o}^{\cdot}$(0.33 eV) as dominant defects in Co and Ni co-doped ZBS system, however only ${V_o}^{\cdot}$ appeared in Co- or Ni-doped ZBS. Even though the same defects it was different in capacitance (1.5~4.5 nF) and resistance ($0.3{\sim}9.5k{\Omega}$). The varistor characteristics were improved with Co and Co+Ni doping (non-linear coefficient, ${\alpha}$= 36 and 29, relatively) in ZBS. The various parameters ($N_d=1.43{\sim}2.33{\times}10^{17}cm^{-3}$, $N_t=1.40{\sim}2.28{\times}10^{12}cm^{-2}$, ${\Phi}b$=1.76~2.37 V, W= 98~118 nm) calculated from the C-V characteristics in our systems did not depend greatly on the type of dopant, which were in the range of a typical ZnO varistors. It should be derived a improved C-V equation carefully for more reliable parameters because the variation of the varistor capacitance as a function of the applied dc voltage is depend on the defect, frequency, and temperature.