• The Journal of Engineering Geology
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• v.21 no.4
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• pp.323-336
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• 2011

The hydro-mechanical behavior of the Earth's crust is strongly dependent on the fractional volume and geometrical structure of effective pore spaces. This study aims to understand the characteristics of pores using electrical impedance. We measured the electric impedance of core samples (diameter, 38-50 mm; length, 70-100 mm) of three types of granite (Hwangdeung, Pocheon, and Yangsan) and two types of sandstone (Boryung and Berea) with different porosities and pore structures, after saturation with saline water of varying salinities. The results show that resistance decreases but capacitance increases with increasing salinity of the pore fluid. For a given salinity, the resistivity and formation factor are reduced with increasing porosity of the rocks, and the capacitance increases. Berea sandstone shows anisotropy in resistance, tortuosity, and cementation factor, with these factors being highest normal to bedding planes. This result indicates that the connectivity of pores is weakest normal to bedding. In conclusion, the electrical characteristics of the tested samples are related not only to their porosity but also to the pore geometry.

• Journal of Wetlands Research
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• v.16 no.3
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• pp.315-325
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• 2014

Valuation of ecosystem services through organic carbon distribution and cycling in the Quercus mongolica forest at Mt. Worak national park were investigated from May 2012 through April 2013. The amount of carbon allocated to above and below ground biomass was 81.94 and 20.53 ton C/ha. Amount of organic carbon in litter layer was 6.49 ton C/ha. Amount of organic carbon within 50 soil depth was 141.23 ton C $ha^{-1}$ $50cm-depth^{-1}$. Total amount of organic carbon in this Quercus mongolica forest was estimated to 250.19 ton C $ha^{-1}$. The estimated amount of won in this Quercus mongolica forest in terms of total organic carbon was about 5.27 million won $ha^{-1}$. The amount of carbon evolved through soil respiration was 7.31 ton C $ha^{-1}yr^{-1}$. The amount of carbon evolved through microbial respiration and root respiration was 3.58 and 3.73 ton C $ha^{-1}yr^{-1}$, respectively. The amount of organic carbon absorbed from the atmosphere of this Quercus mongolica forest was 1.61 ton C $ha^{-1}yr^{-1}$ when estimated from the difference between net primary production and microbial respiration. This amount will come to about 33,000 won $ha^{-1}yr^{-1}$ in Korean currency.

• Environmental and Resource Economics Review
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• v.19 no.3
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• pp.597-632
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• 2010

There is general agreement that global warming is occurring and that the main contributor to this probably is the buildup of green house gasses, GHG, in the atmosphere. Two main contributors are the utilization of fossil fuels and the deforestation of many regions of the world. The burning of fossil fuels increases atmospheric carbon while the burning of fuel-wood reducing fossil fuel consumption along with its forest source maintain an atmospheric carbon level. The standing timber in the forests is a carbon sink, as are wood buildings and structures, and fossil fuel in the ground. This paper is designed to examine a number of current issues related to mitigating the global warming problem through forestry. For this purpose, we develop a modeling approach by integrating timber market, fossil fuel market and carbon cycling model. We use discrete time optimal control theory to identify optimal time paths, the laws of motion, and stationary stats solutions of endogenous variables in the model. On the basis of these results, we identify the optimal amounts of subsidies to be provided or taxes to be imposed by the regulatory agency to mitigate atmospheric carbon accumulation. We also present a numerical example to help illustrate the characteristics of variables in the model when the social cost for atmospheric carbon incrementally shifts upward. A surprising result is that the social cost function for atmospheric carbon has a very smaller impact on the optimal rotation period than previous literature suggested.

• Journal of the Korean GEO-environmental Society
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• v.15 no.5
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• pp.31-37
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• 2014

In situ investigations and laboratory tests using elastic wave have become popular in geotechnical and geoenvironmental engineering. Propagation velocity of elastic wave is the key index to evaluate the ground characteristics. To evaluate this, various methods were used in both time domain and frequency domain. In time domain, the travel time can be found from the two points that have the same phase such as peaks or first rises. Cross-correlation can also be used in time domain by evaluating the time shift amount that makes the product of signals of input and received waveforms maximum. In frequency domain, wave propagation velocity can be evaluated by computing the phase differences between the source and received waves. In this study, wave propagation velocity evaluated by the methods listed above were compared. Bender element tests were conducted on the specimens cut from the undisturbed hand-cut block samples obtained from Block 37 excavation site in Chicago, IL, US. The evaluation methods in time domain provides relatively wide range of wave propagation velocities due to the noise in signals and the sampling frequency of data logger. Frequency domain approach provides relatively accurate wave propagation velocities and is irrelevant to the sampling frequency of data logger.

• Journal of Wetlands Research
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• v.17 no.4
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• pp.332-338
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• 2015

Valuation of ecosystem services through organic carbon distribution and cycling in the Pinus densiflora forest at Mt. Worak National Park were investigated from January 2013 through December 2013. The amount of carbon allocated to above and below ground biomass was 32.17 and 8.04 ton C $ha^{-1}$. Amount of organic carbon in litter layer was 5.55 ton C $ha^{-1}$. Amount of organic carbon within 50cm soil depth was 58.62 ton C $ha^{-1}$ 50cm-$depth^{-1}$. Total amount of organic carbon in this Pinus densiflora forest was estimated to 104.38 ton C $ha^{-1}$. The estimated amount of won in this Pinus densiflora forest in terms of total organic carbon was about 10.44 million won $ha^{-1}$. The amount of carbon evolved through soil respiration was 4.44 ton C $ha^{-1}yr^{-1}$. The amount of carbon evolved through microbial respiration and root respiration was 2.18 and 2.27 ton C $ha^{-1}yr^{-1}$, respectively. The amount of organic carbon absorbed from the atmosphere of this Pinus densiflora forest was 0.44 ton C $ha^{-1}yr^{-1}$ when estimated from the difference between net primary production and microbial respiration. This amount will come to about 44,000 won $ha^{-1}$ in Korean currency.

• Journal of the Korean Institute of Gas
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• v.7 no.1 s.18
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• pp.1-9
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• 2003

A Multi-distinction Equipment Screening Algorithm (MESA) is proposed. It selectively integrates Dow's F&EI as its process hazard index technique and ESA (Equipment Screening Algorithm) as qualitative hazard classification technique, and retrieves a detailed list of hazardous equipments with the total hazard indices of those equipments. The inherent expert system, which includes the accident scenarios of the equipments and processes and experts' views of them, narrows further down the list of hazardous equipments and recommends only the most notable candidates. Through the case study of distinguishing the hazardous ranking of the equipments of the LPG underground storage process, using the expert system or not, the applicability of MESA has been validated. Taking the characteristics of the process equipments with hazardous ranking in the point of process intrinsic safety, this proposed algorithm would contribute to providing engineers or managers with information on constructing safely devices and mitigation devices and on scheduling emergency response planning.

• Proceedings of the Korea Water Resources Association Conference
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• 2012.05a
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• pp.278-278
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• 2012

최근 녹색도시를 지향하면서 도시 내에서의 물의 순환에 대한 관심이 높아지고 있으며 도시계획 단계에서부터 물의 순환을 고려하려는 시도가 이루어지고 있다. 국토해양부, 환경부, 소방방재청 및 지방자치단체들은 법령, 기준, 지침 및 조례 등을 제정하여 물순환을 도시개발 이전의 상태가 될 수 있도록 시설 설치를 유도하고 있다. 그러나, 개별시설들의 조합이 유역규모의 물순환에 미치는 영향 평가는 이루어지고 있지 못한 실정이다. 종래에는 홍수저감을 목적으로 홍수저류지와 침투시설에 대하여 설계하고 시공을 하였으나 장기적인 관점에서 LID 시설의 효과를 평가하여 도시 계획 단계에서 반영하지는 못하였다. 그리고 이들 개별 LID 시설(침투, 저류 등)에 대한 단위 시설의 규모 설계에 그치고 있어 개선 시설이 다중으로 조합되어 분산 계획되었을 경우, 유역 규모에서 물순환의 긍정적인 변화를 판단하기는 어려운 형편이다. 도시지역에서의 LID(Low Impact Development) 효과 분석과 연계된 유역 물순환 해석을 위하여 독일, 호주 및 미국에서는 STORM, Urban Developer, SUSTAIN(System for Urban Stromwater Treatment, and Analysis INtegratration) 및 SWMM LID(Storm Wastewater Management Model LID) 등의 모형을 출시하고 실무에 적용하고 있다. 그러나, 해외에서 개발된 기술은 국내의 유역 환경을 충분히 반영하기 어렵다. 저수지 혹은 하천에서의 취수 등과 같이 국내의 복잡한 물순환 형태를 반영하는데 한계가 있으며, 기존의 물순환 해석모형에 의한 LID 시설을 계획하는 방법은 홍수저감에 국한되어 있고, 하천 유량이나 지하수위 측정 자료가 부족한 대상지역에 대한 장기적인 유역 물순환 및 도시 개발과 같은 토지이용 변화가 물순환에 미치는 영향을 해석하는데 있어 제한이 있고, 개별적으로 설치된 LID 시설들이 유역의 물순환을 개선하는 효과를 종합적, 정량적으로 구현하는데 한계가 있다. 본 연구에서는 도시 개발 지역의 장기간에 걸친 물순환의 변화를 예측하고 물순환을 개선시키는 대안 시설의 효과를 사전에 평가하는 것을 목표로 김현준 등(한국건설기술연구원, 2011)이 개발한 유역 물순환 해석 모형인 CAT(Catchment hydrologic cycle Assessment Tool)을 이용하였다. 특히, CAT은 사용자의 목적에 맞는 다양한 물순환 개선시설(침투시설, 저류지, 습지, 빗물저장 시설, 리사이클 및 외부급수 등)의 구현 및 모의가 가능하도록 개발되었다. 대상유역으로는 경기도 Y지구를 선정하였으며 도시개발 시나리오(전원도시 및 산업도시 등)에 따른 LID 효과 분석을 실시하였다. 대상지역에 대한 도시유형별 개발계획에 따른 개발 전 후 물순환 변화량 분석 및 LID 시설 계획에 의한 물순환 개선효과를 살펴보면 1998년부터 2007년까지의 평균 강우량을 1,271mm라고 할 때 산업도시의 경우 도시 개발 전의 증발산, 직접유출 및 기저유출은 각각 53%, 29%, 19%로 나타났으며 도시 개발 후 35%, 54%, 12%로 직접유출이 개발 전에 비해 86%나 증가하여 개발에 따른 영향이 큰 것으로 나타났다. 따라서, 이러한 개발에 따른 영향을 최소화하기 위하여 LID 시설을 계획하여 효과를 분석한 결과 증발산, 직접유출, 기저유출이 44%, 34%, 13%로 나타나 도시 개발 후의 왜곡된 물순환 체계가 개발전의 수준과 근접하게 나타나 LID 시설의 긍정적인 효과를 검토할 수 있었다. 이상에서와 같이 CAT 모형을 사용하여 도시유역의 물순환 체계를 진단하고, LID 시설의 효과를 평가할 수 있게 됨으로써 향후 도시유역에 대한 물순환 정상화를 실현하기 위한 정책 수립에 기초자료를 제공하고, 설계 실무에 활용될 수 있을 것이다.

• Food Science of Animal Resources
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• v.29 no.3
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• pp.356-363
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• 2009

This study was carried out to investigate the effect of hot boning and curing condition on the quality characteristics of ground chicken breast. Treatments were cured by four conditions follows; control (general curing method), T1 (after hot-boning and then immediately cured), T2 (after hot-boning and immediately cured, then frozen), and T3 (after hot-boning, immediately frozen, refrigerated and then cured). The pH of chicken breast in the state of pre-rigor was 6.22. The pH of cold storage or freezing chicken breast meat respectively were 5.70 or 5.61. The pH of T1 and T2 treatments were significantly higher than those of control and T3 treatment (p<0.05). After stored for 1 wk, the pH value of T1 treatment had a higher value than those of other treatments. T1 treatment had the highest water holding capacity and the lowest cooking loss among all treatments, regardless of the cooking methods. The reduction in diameter for T1 and T2 treatments was lower than those of control and T3 treatment (p<0.05). T1 treatment had the lowest fat loss and moisture loss among all treatments, and the emulsifying capacity of T1 treatment was the highest. The protein solubility of T1 treatment was significantly lower than that of T3 treatment.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.48-48
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• 2019

Amorphophallus paeoniifolius (Dennst.) Nicolson는 영명으로 Elephant yam 또는 Whitespot giant arum 으로 불리는 천남성과(Araceae) 식물로 동아시아, 뉴기니, 오세아니아, 마다가스카르 등지에서 자생하고 있으며 숲의 가장자리 또는 2차림에서 발견 된다. 다년생 식물로 덩이줄기는 어두운 갈색의 둥근모양으로 직경 20~25 cm로 자라고 수염뿌리가 사방으로 달린다. IUCN 적색목록(Red List)에 관심대상 종(LC: Least Concern)에 속하는 식물이다. 현지인들은 마(Dioscorea Polystachya Turcz.)처럼 채소로 먹기도 하며 약용으로 쓰이기도 하는데 복부장애, 소화불량, 천식, 기관지염, 빈혈 등에 약효가 있다. Amorphophallus paeoniifolius은 $25^{\circ}C{\sim}35^{\circ}C$, 연강수량 1,000~1,500 mm에서 잘 자란다. 가운데 눈이 올라오면서 생장을 시작하고 며칠이 지나서야 잎 또는 꽃으로 자라는지 알 수 있다. 잎의 생육주기는 잎눈이 생장을 시작하면 잎자루 끝에 소엽과 소잎자루가 접힌 채로 올라온다. 소엽들이 펴지면서 완전한 모습을 갖추는데 30일 이상의 생장기간을 갖는다. 잎의 형태는 우상복엽(pinnate compound leaf)으로 우산처럼 보이는 잎 하나로 광합성을 한다. 잎은 최대 높이 2.5~3 m, 너비 3 m까지 자라며, 잎자루의 색은 녹색과 청색으로 얼룩덜룩한 무늬가 있다. 인공환경 조건에서 Amorphophallus paeoniifolius 생활사 중 잎의 주기를 연구하기 위해서 광, 온도 등의 지상부 환경은 열대 및 아열대 식물의 자생지와 유사하게 조성하였고, 지하부 환경은 인공 배합토를 사용하여 조성하였다. 평균온도는 $25{\sim}28^{\circ}C$, 겨울철 최저 $16^{\circ}C$, 여름철 최고 $33^{\circ}C$를 유지 관리 하였다. 자동 환경제어시스템으로 온도 및 환기를 유지 관리하고 필요에 따라 수동제어 관리를 병행하여 조절하였다. Amorphophallus paeoniifolius는 잎을 먼저 생성하고 광합성으로 생산된 영양물질을 덩이뿌리에 저장을 하고 그 영양물질을 이용하여 꽃을 피우는 생육 특성을 지닌다. 실험에 사용된 공시 식물은 2018년 12월 미얀마에서 생체(덩이줄기) 형태로 도입되었다. 화분에 식재 후 약 5개월이 지난 시점에서 잎의 생장이 시작되었다. 2019년 7월 29일 기준으로 높이 80 cm, 너비 60 cm의 크기로 성장하였으며, 생육환경에 따라 3~5개월 뒤 잎이 지고 나면 다시 덩이줄기로 되돌아갈 것으로 판단된다. 하지만 지금까지 이 식물에 알려진 정보는 인공환경에서의 연구가 아닌 자연환경에서의 연구결과이기 때문에 인공적인 온실 환경에서 자란 Amorphophallus paeoniifolius는 잎의 주기는 더 오래 갈 수도 있으며 꽃의 주기 또한 느리거나 빠를 수 있다. 잎의 생장주기(Leaf Cycle)시 잎자루가 낮과 밤의 방향을 달리 하여 자라는 것이 관찰되었다. 이는 광합성을 위해서 잎자루의 방향을 햇빛 방향으로 돌리는 것으로 판단된다. Amorphophallus paeoniifolius를 실내 조경 식물 또는 식 약용의 소재식물로 활용하기 위해서는 꽃의 생장주기 등 추가적인 모니터링과 연구가 필요하다.

• Tunnel and Underground Space
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• v.31 no.1
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• pp.52-65
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• 2021

In this study, authors analyzed the vapor cloud explosion induced by propane leak at the PEMIX Terminal, which is the propane storage facility outside of Mexico City. TNT equivalence mass for the leaked 4750 kg propane was estimated to be 9398 kg. Blast parameters such as peak overpressure, positive phase duration, and impact at 40-400 (m) away from the center of the explosion were calculated by applying TNT Equivalency Method and Multi-Energy Method. The probability of damage due to lung damage, eardrum rupture, head impact, and whole-body displacement impact by applying the probit function obtained using blast parameters was evaluated. The peak overpressure obtained using Multi-Energy Method was found to be greater than the peak overpressure obtained by applying the TNT Equivalency Method at all distances considered, but it was evaluated that there was no significant difference from the points above 200 m. The peak overpressure obtained by Multi-Energy Method was computed to assess the extent of damage to the structure, and it was shown that structures within 100 m of the explosion center would collapse completely, and that the glasses of the structures 400 m away would be almost broken. The probability of death due to lung damage was shown to vary depending on a human body's position located in the propagating direction of shock wave, and if there is a reflecting surface in the immediate surroundings of a human body, the probability of death was estimated to be the greatest. The impact of shock wave on lung damage, eardrum rupture, head impact, and whole-body displacement impact was evaluated and found to affect whole-body impact < lung damage < eardrum rupture