• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2018.06a
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• pp.30-30
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• 2018

스마트 도금공장을 구축하기 위해서는 도금액 내부의 화학 물질 농도 변화를 측정할 수 있는 화학 센서 기술이 필수적으로 요구된다. 와트욕은 대표적인 고속 니켈 도금액 중 하나로 기본적으로 황산니켈, 염화니켈, 보릭산의 염과 함께 케리어(type-1 광택제), 광택제(type 2-광택제), 응력 제어제 등의 유기 첨가제로 구성되어 있다. 이러한 유기 첨가제는 전차된 니켈층의 두께 균일도, 조도, 미세 구조, 내부 응력 등 다양한 특성을 제어하며, 정밀한 농도 관리가 필수적으로 요구되나, 분석 기술의 부재로 인하여 지금까지도 대부분의 액관리는 할셀법이나 작업자의 경험에 의존하고 있다. Cyclic voltammetry stripping(CVS) 방법은 전기화학 분석 과정에서 나타나는 첨가제의 가속, 감속 특성 등과 여기에 수반되는 stripping peak의 변화를 이용하여 개별 첨가제의 농도를 측정하는 방법이며, 지금까지 인쇄회로기판의 비아필 공정, 전해 동박 제조, 반도체 배선 등 구리도금 산업 전반에 걸쳐 첨가제 관리에 효과적으로 적용되고 있다. 그러나 수소 발생으로 인한 stripping 효율 문제로 인하여 니켈, 주석, 아연 등 표준 환원 전위가 높은 금속 도금액 내부 첨가제 농도 측정은 아직 어려운 상황이다. 본 연구에서는 이 문제를 극복하기 위해 염소를 과량 첨가한 구리 도금액을 CVS 분석의 base 용액으로 이용하여 니켈 도금액 내부 여러 광택제 (polyetylene glycol(PEG) 계열, thiourea 계열, 2-butyne-1,4-diol 등) 농도를 측정하는 법을 제시하였다. 제시된 방법은 CVS 분석 과정에서 구리-염소 사이의 상호 작용으로 인해 생성되는 3가지 stripping peak의 상대적인 크기 변화가 첨가제 농도에 따라 영향을 받는다는 사실에 기반하였다. 본 연구에서는 여기에 관한 원인에 대해 고찰하였으며, 제시된 방법을 통해 광택제 계열 첨가제 농도 측정을 선택적으로 할 수 있다는 것을 증명하였다.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.1
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• pp.13-21
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• 2008

This study conducted water quality projection of year 2010 in Miho stream of the Geum river basin by using GIS. Pollutant load data of corresponding tributary of the Miho stream is estimated based on the pollutant load of TMDL zone to simulate water quality of the Miho stream for BOD, TN, and TP. The pollutant load of the urban area such as Bochung and Musim stream basin is relatively high and the wastewater treatment plant of Chunju city directly affects the entire water quality of the target area. As a result, simulation result reveals that water treatment facility needs more refined treatment process for efficient water quality management. Also, to meet the target water quality of the Miho stream water quality simulation estimates the additional dilution flow by increasing irrigation water supplied from the Daechung dam through the Musim stream.

• Fire Science and Engineering
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• v.17 no.3
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• pp.1-6
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• 2003

In this study, it reviewed about evacuation performance of a specified Office Building. assessment tools is FAST 3.1.7 (Estimation of Flash Over, Estimation of Layer Height Down Flow Time), SIMULEX 32-bit (Estimation of Evacuation Time), JASMINE 3.25d. (Smoke Flow Assessment of a specified time) Result from Fire Scenario # 1, Flash Over is not generated in Compartment. Evacuation Time is estimated 25.2 sec by SIMULEX 32-bit. layer height until this time (25.2 sec) was estimated 2.4 m by FAST 3.1.7. After ignition until this time (25.2 sec), smoke was not release to the a corridor. In consequence, We concluded that people in building are completing the safe evacuation without the damage of smoke. Result from Fire Scenario # 1, Flash Over generated 6 min 33.2 sec in Compartment. Evacuation Time is estimated 1 min 25.5 sec by SIMULEX 32-bit. layer height down flow time is 1 min 40.8 sec by FAST 3.1.7 and 5 min 23 sec by theoretical calculation. Also, total building evacuation time was estimated 2 min 26.6 sec. After ignition until this time (2 min 26.6 sec), smoke released to the a corridor but it amount was few little. Therefore, generated smoke in compartment not effected to the people in buildings.

• Korean Journal of Food Science and Technology
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• v.33 no.3
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• pp.353-360
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• 2001

Physicochemical characteristics of kochujang prepared with addition of garlic and onion, were investigated for 22 weeks of fermentation to obtain information on improving the quality of traditional kochujang. Moisture contents of kochujang increased during fermentation, but total nitrogen contents decreased slightly. The pH and titratable acidity of kochujang changed a little by addition of garlic or onion. Total sugar contents of kochujang decreased rapidly after 4 weeks, but reducing sugar contents increased until 2 weeks of fermentation. As the ratio of garlic increased, reducing sugar contents decreased. Ethanol contents increased during fermentation as mixing ratio of onion increased. Amino nitrogen contents of kochujang increased as mixing ratio of garlic or onion increased, but ammonia nitrogen contents decreased. Water activities of kochujang decreased slightly during fermentation, but consistency increased until 18 weeks. The color values of garlic or onion added kochujang were low in the L-values, but a- and b-values increased. Results of sensory evaluation showed garlic added$(2{\sim}4%)$ kochujang were more acceptable than onion added kochujang due to more favorable taste and flavor.

• Korean Journal of Food Science and Technology
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• v.16 no.1
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• pp.1-6
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• 1984

The three kinds of Kochujang were prepared with liquid koji equivalent to 30%, 50%, and 70% of brewing water. The qualities of the Kochujangs during aging at $25^{\circ}C$ for 4 months were compared with those of the control group which was made from solid koji. There were no significant differences in the contents of moisture, crude protein, crude fat, NaCl and ethyl alcohol between test groups. The contents of amino nitrogen, soluble nitrogen, reducing sugar and pH of each test group during Kochujang aging were high in the order of control group. 70% liquid koji group, 50% liquid koji group and 30% liquid koji group. The pH of control group was over 5.0 during aging period. The titratable acidity of Kochujang was high in the 50% liquid koji group and the 30% liquid koji group.

• Korean Journal of Food Science and Technology
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• v.22 no.3
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• pp.357-362
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• 1990

Soy yoghurt was prepared from 19 soybean cultivars with the use of L. acidophilus KCTC 2182. Various characteristics of fermented soymilk and the ratio of product recovery in soy yoghurt were investigated The mean crude protein content of the soy yoghurt was 2.74% with a range of 2.58-2.91% and the mean crude fat content was 1.49% with a range of 1.34-1.85%. Total solids recovered from original soybean in soy yoghurt ranged 52.14-61.54% with a mean value of 56.17%. Crude protein recovery in soy yoghurt ranged 59.22-67.5% with a mean value of 63.32%, Crude fat ranged 65.8-86.02% with a mean value of 72.57%. Titratable acidity of soy yoghurt ranged 0.20-0.41%. Viable cell count of soy yoghurt ranged $3.83{\times}10^8-3.22{\times}10^9/ml$ and the amount of separated whey ranged 1.4-8.2ml per 100ml of soymilk.

• Journal of the Korean Electrochemical Society
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• v.23 no.3
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• pp.73-80
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• 2020

Fenton oxidation method using hydrogen peroxide is an eco-friendly oxidation method used in water treatment and soil restoration. When removing pollutants by this method, it is quite important to properly regulate the concentration of hydrogen peroxide according to the concentration of the contaminants. In this study, electrochemical biosensors using HRP (horseradish peroxidase) enzymes were manufactured and studies were conducted on the activity of enzymes and the detection characteristics of hydrogen peroxide. HRP were electro deposited with chitosan and AuNP on the working electrode surface of the SPCE (Screen Printed Carbon Electrode). Then, the fixation of enzymes was confirmed using the cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The activity of HRP enzymes was also identified from chronoamperometry (CA) and UV spectroscopy. After immersing the biosensor in PBS solution the current generated from electrodes by titrating hydrogen peroxide was measured from CA analysis. The generated current increased linearly for the concentration of hydrogen peroxide, and a calibration curve was derived that could predict the concentration of hydrogen peroxide from the current.

• Food Science and Preservation
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• v.22 no.3
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• pp.322-327
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• 2015

Bamboo sprout powder was added to Jeonbyeong dough for improving its quality and functional properties. Crude protein and ash content increased as the amount of bamboo sprout powder increased, while the crude fat content was decreased. As the content of bamboo sprout powder increased, total amino acid content also increased. As bamboo sprout powder content increased, Hunter's L, a and b values decreased whereas sugar-free content increased. The addition of bamboo sprout powder to Jeonbyeong increased its dietary fiber contents. The sensory score of Jeonbyeong containing 300 g of bamboo sprout powder showed the highest score among all other tested Jeonbyeong. Based on the results, the addition of bamboo sprout powder could improve the quality and sensory characteristics of Jeonbyeong.

• Food Science and Preservation
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• v.9 no.1
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• pp.51-55
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• 2002

Changes in food components of oyster mushroom Kimchi were investigated during storage at 20$^{\circ}C$. The pH of raw oyster mushroom Kimchi (ROMK) was higher than that of Chinese cabbage Kimchi (control) at initial stage, but it was lower than that of control after 1 day of storage. pH of blanched oyster mushroom Kimchi (BOMK) was slightly higher than that of controls The titratable acidity of oyster mushroom Kimchi was in inverse state to the pH. Amino acid nitrogen content of Kimchi tended to increase during storage, the content of ROMK was higher than that of control, the content of BOMK was not different from that of control. The reducing sugar content of Kimchi decreased significantly during storage, the content of ROMK was higher than that of controls the content of BOMK was slightly lower. The bacterial number of control increased rapidly at 2 days fermantation and reached plateau afterward. The number of ROMK tended to he alike that of control during storages the number of BOMK was fewer than that of control. On the taste panel of Kimchi after 1 day of storages ROMK obtained higher score than BOMK but the score was lower than control.

• Food Science and Preservation
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• v.9 no.2
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• pp.200-204
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• 2002

This study was carried out to investigate the effect of safflower powder on the characteristics of kimchi. Quality indexes were pH, titratable acidity, reducing sugar content, microbial counts, and sensory evaluation. Safflower powder enhanced the decrease in pH and increase in titratable acidity during fermentation at l0$^{\circ}C$, and the changes were more conspicuous until 15 days. Stabilized levels in pH was attained, but steady increase in titratable acidity was shown after that time. Microbial loads of total and lactic acid bacteria showed a faster stationary phase for kimchi samples with safflower powder than control. Control was better scores in sensory evaluation, but there were no significant differences in aroma and taste except sample with 3% safflower powder.