• 한국식품영양학회지
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• 제30권3호
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• pp.591-598
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• 2017

To prolong the shelf-life of strawberry, samples were treated with gel packs containing slow-released chlorine dioxide($ClO_2$) gas at 3~7 ppm for 6 days at room temperature. The weight loss and decay ratio as well as changes in pH, color and texture properties of the treated samples were investigated. The weight of the control and $ClO_2$ gas treated samples decreased slightly, but the weight of the control changed faster than those of the $ClO_2$ gas treated samples during the storage period. The decay ratio of control was higher than those of the $ClO_2$ gas treatments since 4 days of storage. The pH and acidity in the control and in the $ClO_2$ gas treated samples were no differences during storage period. The lightness of strawberry decreased during storage, but there was no difference in lightness among the treatments even when storage time was extended. The redness and yellowness of the control showed higher change than those of the $ClO_2$ gas treatments during 6 days. The firmness of the control changed more rapidly than those of the $ClO_2$ gas treatments during 6 days. Especially, the samples treated 3 and 5 ppm $ClO_2$ gas were the least changed. And the scores for appearance, firmness and overall acceptance control and 7 ppm $ClO_2$ gas treatment decreased more rapidly than those of 3 and 5 ppm treatment.

• 한국식품저장유통학회지
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• 제2권1호
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• pp.203-207
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• 1995

Spices(Tumeric, Celery-seed, Cumin, Black pepper, Coriander) were irradiated at dose levels of 0, 5, 7 and 9kGy using Co60 source and stored at room temperature. After 12 months of storage following 9kGy irradiated spice, total aerobic bacteria were significantly decreased. When the irradiation dose was 7kGy, microbial levels showed l02-103 levels. However, total lactic acid bacteria and E-coli were shown negative at below 5kGy.

• 설비공학논문집
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• 제14권5호
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• pp.433-440
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• 2002

Simulations were carried out to investigate the characteristics of $CO_2$ emissions for an electric powered air conditioning system. The $CO_2$ emissions were evaluated for various simulation parameters such as a power source distribution rate, power plant efficiency, power supply efficiency and system performance (COP). It was found that the $CO_2$ emissions were remarkably decreased by increasing the COP of the electric powered air conditioning system with storage tank. The $CO_2$emission per unit refrigeration capacity is 0.6 kg/RTh. And also, as the COP increase by 0.1, the $CO_2$ emissions decrease by 7.2%.

• 한국지열·수열에너지학회논문집
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• 제11권3호
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• pp.7-12
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• 2015

Currently water supply system with water storage is generally applied except for small building such as single-family houses, and water supply system on replacing water storage installed system by direct connecting system has been increasing because of sanitary and energy-saving aspects. The purpose of this study is to evaluate energy-saving and environmental efficiency of direct connecting booster pump system in comparison with the water storage installed system. The architectural condition of the evaluation subject is ten-story apartment house in which sixty households live. To calculate the power consumption of the pump, the volume of water supply was determined from existing data and other data, such as head, efficiency of the pump, was the value used for general application in design office. The power consumption of the water supply pump for one day was 8.5 kWh for direct connecting booster pump system, and 22.5 kWh for water storage installed system, and the former system showed energy savings of 62% compared to the latter system. Reduced power consumption also leads to reduction of $CO_2$ emission. According to the criteria presented in the Korea Energy Management Corporation, reducing the 2,410 kg $CO_2$ emission is possible per year.

• 한국가금학회지
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• 제43권1호
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• pp.31-38
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• 2016

Consumers demand fresh and high-quality eggs. Egg quality may be represented by shell color, shell weight, egg weight, shell thickness, shell density, albumen height, yolk color, albumen pH and viscosity. Various factors such as strain, age of hen, storage temperature, humidity, the presence of $CO_2$ and storage time affect egg quality. Therefore, we investigated the effects of storage time and temperature on egg quality to define the freshness of Korean market eggs. A total of 1,800 eggs were used for this experiment and were separated into 45 treatments with 40 eggs in each. The treatments were consisted of 15 storage periods (2 d to 30 d) and 3 storage temperatures ($2^{\circ}C$, $12^{\circ}C$, $25^{\circ}C$). Each egg was weighed and broken, and the height of the thick albumen, Haugh units (HU), egg shell color and yolk color were measured by a QCM+system. We also observed the physiochemical properties of eggs such as yolk pH, albumen pH and albumen viscosity. The egg weight, shell weight, albumen height, HU and albumen viscosity significantly decreased with increasing storage time and temperature. However, the albumen and yolk pH significantly increased with increasing storage period and temperature. The interaction effects between the storage period and temperature were significant for shell weight, shell density, egg weight, albumen height, HU, yolk color, yolk pH, albumen pH and albumen viscosity. In the analysis of the correlation with egg quality, the storage temperature exhibited a higher correlation coefficient than the storage period. In conclusion, storage time and temperature are the major factors affecting egg quality, but the storage temperature is a more sensitive determinant of egg quality deterioration compared with the storage period.

• 한국미생물·생명공학회지
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• 제1권1호
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• pp.25-30
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• 1973

본 연구는 1971년과 1972년 9월 25일에 수확한 흥옥과 동년 10월 25일에 수확한 국광을 시료로하여 이들 사과의 저장에 있어서 환경압력 및 환경기체조성이 사과조직내 기체조성과 호흡 및 ethylene 생성에 미치는 영향을 규명하기 위하여 실험하였던 바 그 결과는 다음과 같다. 1. 과실조직내 기체량은 환경압력에 비례적으로 변화하며, 환경압력이 사과의 조직내 기체조성 및 기체량에 현저하게 영향을 미쳤다. 2. 조직내 $CO_2$발생량의 증가는 조직내 $O_2$ 소비량에 관련되며, 그러므로 내부 $O_2$ 소비의 감소되는 시기와 호흡에 있어서 climacteric rise의 시기와 일치하였다. 3. $CO_2$ 발생량의 증가는 ethylene 생성 후에 나타나며 그리고 상압구의 이와 같은 현상은 감압구에 잇달아 일어난다. 4. 감압저장에 있어서도 저산소농도와 고탄산가스농도의 조절로써 CA효과를 얻을 수 있다.

• 한국식품과학회지
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• 제27권1호
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• pp.112-118
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• 1995

포장김치의 유통과정 중 안전성과 상품성 유지를 위한 팽창 파열방지 포장기법의 개발과 관련하여 포장방법에 따른 김치의 품질특성 변화를 확인하고자 하였다. 상압(AP), 배기(CV), 이중(DP), 진공(VP) 포장 등으로 김치의 포장방법을 각각 달리하여 $10^{\circ}C$ 에서 저장하면서 포장내 기체조성, 포장내 자유용적, pH, 산도, 색상, 젖산균수 및 관능적 품질변화를 측정하였다. 저장기간이 증가함에 따라 AP와 CV의 포장내 $O_2$ 농도는 지수적으로 감소하고 $CO_2$ 농도는 2단계 증가양상을 나타내었으나, DP에서는 $O_2$ 농도가 일정하고 $CO_2$ 농도는 2단계 증가 후 감소하는 양상을 보였으며, VP는 저장말기에 저농도 $O_2$와 고농도 $CO_2$를 일정하게 유지하는 등 각기 다른 경향을 나타내었다. 포장내 자유용적은 AP와 CV에서 sigmoid 곡선형으로 증가하였으나, DP는 거의 일정하였고 VP는 저장말기에 약간의 증가를 나타내었다. 각 포장구의 pH는 유의차 없이 대부분 비슷하였으나, 산도는 DP가 다른 포장구에 비해 상대적으로 높은 값을 유지하였다. 김치 여과액의 색상변화에서 포장구 모두 L, b값은 전반적으로 감소하고 a값은 일정하게 증가하였는데, 색지수(L b/a) 값으로 표시할 경우 지수적으로 감소하다가 일정하게 유지되는 경향을 나타내었다. 색지수의 변화에 있어 DP는 AP, CV 포장구에 비해 높은 값을, VP는 낮은 값을 보였다. 젖산균수의 변화에 있어서도 DP는 다른 포장구에 비해 급격한 증가를 나타내었으나, VP는 비교적 낮은 수준을 유지하였다. 관능검사 결과 신맛은 DP에서 상대적으로 높았고, 조직감은 각 포장구에서 유의차를 볼 수 없었으며, 기호도에서는 VP>AP, CV>DP의 순서를 나타내었다. 결론적으로 본 연구에서는 김치의 팽창 파열방지 포장기법으로서 배기포장이 상압포장과 큰 차이 없었으나 이중포장과 진공포장은 상당히 효과적임을 알 수 있었다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제20권1호
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• pp.41-55
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• 2015

Monitoring of $CO_2$ release through the ground surface is essential to confirm the safety of carbon storage projects. We conducted a feasibility study of the multi-channel surface-soil $CO_2$-concentration monitoring (SCM) system as a soil $CO_2$ monitoring tool with a small scale injection test. The background concentrations showed the distinct diurnal variation. The negative relation of $CO_2$ with temperature and the low $CO_2$ concentrations during the day imply that surface-soil $CO_2$ depends on photosynthesis and respiration. After 4.2 kg of $CO_2$ injection (1 m depth for 29 minutes), surface-soil $CO_2$ concentrations increased in the all five chambers, which were located less than 2.8 m of distance from each other. The $CO_2$ concentrations seem to be recovered to the background around 4 hours after the injection ended. To determine the leakage, the data from Chamber 2 and 5 with low increase rates were used for statistical analyses. Coefficient of variation for 30 minutes ($CV_{30min}$.) is efficient to determine a leakage signal, with reflecting the fast change in $CO_2$ concentrations. Consequently, SCM and $CV_{30min}$ could be applied for an efficient monitoring tool to detect $CO_2$ release through the ground surface. Also, this study provides ideas for establishing action steps after leakage detection.

• 전기화학회지
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• 제18권2호
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• pp.58-67
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• 2015

음극 표면에 solid electrolyte interphase (SEI)를 형성하는 전해질 첨가제인 lithium bis(oxalate) borate (LiBOB), fluoroethylene carbonate (FEC), vinylene carbonate (VC), 2-(triphenylphosphoranylidene) succinic anhydride (TPSA)를 $Li(Ni_{1/3}Co_{1/3}Mn_{1/3})O_2$ (NCM)/graphite 전지에 도입하여 고온 저장 특성을 비교하였다. 각 전지를 50%의 충전상태(stage of charge, SOC)에서, 고온 저장($60^{\circ}C$, 20일) 시킨 이후의 용량 유지율을 확인한 결과, LiBOB 1 wt.%가 가장 우수한 용량 유지 특성(초기 방전용량 대비 86.7%)을 나타내었다. LiBOB 1 wt.%의 경우 고온 저장 전후의 전지 저항 증가 및 SEI 두께 변화가 가장 적었고, 이는 음극 SEI에 포함된 다량의 semi-carbonate 물질과 연관성이 높다고 판단된다. 또한, LiBOB 1 wt.%가 포함된 NCM/graphite 전지의 상온($25^{\circ}C$) 및 고온수명($60^{\circ}C$) 특성도 기준 전해액(1.15 M lithium hexafluorophosphate (LiPF6) in ethylene carbonate/ethyl methyl carbonate (EC/EMC, 3/7 by volume))보다 각각 6%와 9% 향상된 결과를 보여주었다. 따라서, LiBOB이 상온 성능을 동등 이상으로 유지하면서도 고온 특성을 개선할 수 있는 우수한 전해액 첨가제로 판단된다.

• 지질공학
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• 제28권1호
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• pp.35-45
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• 2018

이미징 기술은 매질 자체의 구조특성 뿐만 아니라 유체의 유동특성을 분석하기 위해 공극규모, 코어규모, 그리고 중급규모에서 다양하게 활용되고 있다. 본 기술보고에서는 코어규모에서 유동실험과 이미징기술을 연계하여 균질매질, 균열매질, 그리고 불균질매질에서의 이산화탄소($CO_2$) 유동 특성과 함께 $CO_2$ 주입시 주입관정 주변에서 발생할 수 있는 염침전 현상, 균질매질과 균열매질에서의 모세관압 평가, 그리고 $CO_2$ 주입이 완료된 이후 나타나는 포획메커니즘 평가 등에 대해 살펴보았다. 이미징기술을 통해 코어내에서 시간에 따른 $CO_2$ 플룸을 이미지화 함으로써 유동특성을 분석할 수 있으며, 특히 균열이 포함된 매질과 불균질한 매질에서의 유동 및 저장특성을 평가할 수 있다.