• 생태와환경
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• 제46권1호
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• pp.10-17
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• 2013

History of Instream Flow Incremental Methodology (IFIM) Following the large reservoir and water development era of the mid-twentieth century in North America, resource agencies became concerned over the loss of many miles of riverine fish and wildlife resources in the arid western United States. Consequently, several western states began issuing rules for protecting existing stream resources from future depletions caused by accelerated water development. Many assessment methods appeared during the 1960's and early 1970's. These techniques were based on hydrologic analysis of the water supply and hydraulic considerations of critical stream channel segments, coupled with empirical observations of habitat quality and an understanding of riverine fish ecology. Following enactment of the National Environmental Policy Act (NEPA) of 1970, attention was shifted from minimum flows to the evaluation of alternative designs and operations of federally funded water projects. Methods capable of quantifying the effect of incremental changes in stream flow to evaluate a series of possible alternative development schemes were needed. This need led to the development of habitat versus discharge functions developed from life stage-specific relations for selected species, that is, fish passage, spawning, and rearing habitat versus flow for trout or salmon. During the late 1970's and early 1980's, an era of small hydropower development began. Hundreds of proposed hydropower sites in the Pacific Northwest and New England regions of the United States came under intensive examination by state and federal fishery management interests. During this transition period from evaluating large federal reservoirs to evaluating license applications for small hydropower, the Instream Flow Incremental Methodology (IFIM) was developed under the guidance of the U.S. Fish and Wildlife Service (USFWS).

• 한국지반신소재학회논문집
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• 제9권3호
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• pp.77-85
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• 2010

저수지의 수위변화는 저수지 주변 강기슭 사면파괴의 주요 요인이다. 중국의 삼협댐 저수위는 홍수량 조절을 위해 145m와 175m사이에서 변화한다. 삼협댐 저수위의 정상적 운영상태에서 저수위 변동속도는 0.67m~3.0m의 범위에 있다. 마지아고 사면은 자시강의 2.1km 상류 좌측기슭에 위치한다. 자시강은 삼협지역내에 있는 양츠강의 지류이다. 2003년 저수위가 95m에서 135m로 상승한 직후, 마지아고 사면의 후면부에서 길이 20m, 폭 3~10의 균열이 발생하였다. 지금은 균열 보수 후 특별한 징후는 보이지 않고는 있으나, 이 큰 균열은 마지아고 사면의 산사태 가능성을 암시하고 있었다. 이 연구에서는 저수위 변화와 관련하여 사면내에서 간극수압의 변화를 모의하기 위해 불포화 및 포화 침투해석이 수행되었다. 얻어진 간극수압은 저수위에 따른 안전율 변화를 평가하기 위해 사용되었다. 연구결과 침윤선은 저수위 변화보다 상당히 지연된 반응을 보였고, 저수위의 상승-하강과정에서 침윤선은 각각 요면과 철면의 형상을 나타내었다. 또한 저수위의 변동은 사면의 전면부에만 영향을 미치고 있었고 후면부에는 영향을 미치지 않았다.

• 한국안전학회지
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• 제33권3호
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• pp.46-51
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• 2018

A basic sprinkler system is a fire extinguishing system that can be easily installed in a fire-vulnerable place such as a publicly used establishments. However, the publicly used establishments are not only complicated in structure, but also have a large amount of flammable interior materials, and the users are not normally in a normal state, which is a very dangerous fire-fighting object. Therefore, due to the low fire extinguishing performance of the basic sprinkler system installed in the publicly used establishments, the fire suppression control can not be performed quickly in case of fire, which may increase the life and property damage. In this study, the cases of quantitative changes of extinguishing water used in basic sprinkler system and the cases of addition of additives such as wetting agents, reinforced agents to improve extinguishing performance were compared. Experimental results showed that the extinguishing performance was improved as the quantity of extinguishing water increase and the reinforced agents showed similar performance to that of 60% increase in the amount of extinguishing water. The cooling time to $200^{\circ}C$ and oxygen concentration were improved up to 14.3% and 34.5%, respectively. In the case of using the wetting agent, the cooling time to $200^{\circ}C$ and oxygen concentration did not show any significant improvement, but showed the effect of preventing deep seated fire. In order to prevent loss of life and property, it is necessary to improve the performance of the basic sprinkler system by increasing amount of extinguishing water or using additives like reinforced agents.

• Wind and Structures
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• 제27권4호
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• pp.213-221
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• 2018

In the desert and Gobi regions with strong wind and large sediment discharge, sand transporting engineering is more effective than sand blocking and sand fixing measures in sand prevention. This study uses the discrete phase model of 3D numerical simulation to study the motion trail, motion state and distribution rule of sand particles with different grain diameters when the included angle between the main shaft of the feather-row lateral transportation sand barrier and the wind direction changes, and conducts a comparison in combination with the wind tunnel test and the flow field rule of common sand barrier. According to the comparison, when wind-sand incoming flow passes through a feather-row sand barrier, sand particles slow down and deposit within the deceleration area under the resistance of the feather-row sand barrier, move along the transportation area formed by the transportation force, and accumulate as a ridge at the tail of the engineering. With increasing wind speed, the eolian erosion of the sand particles to the ground and the feather-row sand barrier is enhanced, and the sand transporting quantity and throw-over quantity of the feather-row sand barrier are both increased. When sand particles with different grain diameters bypass the feather-row sand barrier, the particle size of the infiltrating sands will increase with the included angle between the main shaft of the feather-row sand barrier and the wind direction. The obtained result demonstrates that, at a constant wind speed, the flow field formed is most suitable for the lateral transportation of the wind-drift flow when the included angle between the main shaft of the feather-row sand barrier lateral transportation engineering and the wind speed is less than or equal to $30^{\circ}$.

• 대한본초학회지
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• 제35권1호
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• pp.27-33
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• 2020

Objectives : In previous studies, I presented various effects of Seosiokyongsan (SSOOS) cp soap on facial skin. However, in the case of skin clinical trials, various factors such as lifestyle, alcohol, tobacco, and stress could not be excluded. The purpose of this study was to investigate the effect of face wash using SSOOS cp soap on the skin without environmental factors. Methods : The same water and towel were used at the same place in order to examine the skin change state immediately before and after washing face with SSOOS cp soap. The skin test was performed before washing the face and after 10 minutes washing the face to compare the changes. As a control group, the case of washing with water without using cleanser and the case of washing with S-K cleanser, which is a popular commercial product, were set. Three cases were compared and analyzed. Results : In the case of water washing, the decrease in moisture was similar to that of the S-K cleanser and the amount of oil and pores decreased, but it was weaker than that of the S-K cleanser. The SSOOS cp soap showed a decrease in oil, pores, and pigments, but it was not significant, the moisture showed a significant decrease, but it was mild compared to S-K cleanser and water wash. Conclusion : In the case of SSOOS cp soap, the stimulation caused by facial cleansing was the least, showing a gentle change.

• 한국방재학회 논문집
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• 제8권2호
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• pp.59-63
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• 2008

지표수 흐름은 육지 물수지 계산에 중요한 요소중에 하나이다. 그러나, 기상변화의 예측과 그로 인한 방재대책수립을 위한 대규모의 기상모형과 연계되는 육지수문모형(Land Surface Model, LSM)들은 지표수 흐름을 토양수분수지로부터 간단하게 산정하고 있다. 침투계산에서 지표수 흐름깊이를 무시하는 것은 지표면 및 지표하 물흐름 모두에 계산상 오류를 초래할 수 있다. 그러므로, 육지수문모형에서 종합적인 물과 에너지 순환 예측을 하기 위해, 지표수 흐름을 위한 1차원 확산모형과 지표하 물흐름을 위한 계산망 체적평균 토양수분이송(Volume Averaged Soil-moisture Transport Model, VAST)모형을 연계하는 대규모 지표면 및 지표하 연계 물흐름 모형이 개발되었다. 이 논문에서는, 최첨단 육지수문모형중 하나인 CLM(Common Land Model)내의 지표수리수문 모의를 위한 주요부분을 비롯하여, 지형특성에 따른 지표수 흐름과 공간적 토양수분 분포의 예측개선을 위한 새로운 지표면 및 지표하 연계 물흐름 모형에 대해 기술하였다.

• 한국해양생명과학회지
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• 제2권2호
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• pp.49-55
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• 2017

Four chemical treatments with hydrogen peroxide (H₂O₂), copper sulfate (CuSO₄), potassium permanganate (KMnO₄) and chlorine (Cl₂) were applied to the effluent pond water of a hybrid striped bass saltwater recirculating aquaculture system to compare their oxidation power. Four chemicals were applied at concentrations of 0 (control), 1, 5, 10 and 20 mg/l. An additional concentration of 40 mg/l was included in the chlorine treatment. Water samples from four hybrid striped bass ponds were tested with KMnO₄ and Cl₂. H₂O₂ did not reduce any of BOD, COD and chlorophyll-a, and copper sulfate was only effective on chlorophyll-a for the effluent pond. Removal efficiencies for chlorophyll-a by copper sulfate were 19.2%, 37.5%, 54.2% and 74.1% dose-dependently. Potassium permanganate effectively removed the BOD, COD and chlorophyll-a. The COD removal rates in four fish ponds varied from 15.9% to 31.6% at the concentration of 10 mg/l. Interestingly, Cl₂ did not reduce the BOD and COD at all, but the BOD and COD instead increased drastically with increasing the Cl₂ concentration. The pond water with the highest initial BOD and COD values among the fish ponds tested increased by 350% in the BOD and 150% in the COD at 20 mg/l. Furthermore, Cl₂ did not significantly reduce any types of solid matter in this study, while KMnO₄ seemed to reduce some extent volatile dissolved solid in the fish pond.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1199-1203
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• 2010

Second-order rate constants ($k_N$) have been measured spectrophotometrically for Michael-type reactions of 1-(X-substituted phenyl)-2-propyn-1-ones (2a-f) with a series of alicyclic secondary amines in MeCN at $25.0{\pm}0.1^{\circ}C$. The $k_N$ value increases as the incoming amine becomes more basic and the substituent X changes form an electron-donating group (EDG) to an electron-withdrawing group (EWG). The Br${\o}$nsted-type plots are linear with ${\beta}_{nuc}$ = 0.48 - 0.51. The Hammett plots for the reactions of 2a-f exhibit poor correlations but the corresponding Yukawa-Tsuno plots result in much better linear correlations with ${\rho}$ = 1.57 and r = 0.46 for the reactions with piperidine while ${\rho}$ = 1.72 and r = 0.39 for those with morpholine. The amines employed in this study are less reactive in MeCN than in water for reactions with substrates possessing an EDG, although they are ca. 8 pKa units more basic in the aprotic solvent. This indicates that the transition state (TS) is significantly more destabilized than the ground state (GS) in the aprotic solvent. It has been concluded that the reactions proceed through a stepwise mechanism with a partially charged TS, since such TS would be destabilized in the aprotic solvent due to the electronic repulsion between the negative-dipole end of MeCN and the negative charge of the TS. The fact that primary deuterium kinetic effect is absent supports a stepwise mechanism in which proton transfer occurs after the rate-determining step.

• 한국식품과학회지
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• 제26권4호
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• pp.428-435
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• 1994

쌀전분의 다각적 이용을 위하여 고순도의 멥쌀전분과 찹쌀전분을 Alkali 침지법에 의해 제조하여 각각 드럼 건조기와 압출성형기로 변성전분을 제조한 후 특성을 검토하였다. 청값은 찹쌀전분이 가장 낮았으며 변성 후 L값이 감소하였다. 수분용해지수는 압출성형기로 제조한 변성전분들이 높은 값을 나타내었으며 수분흡수지수는 드럼건조기로 제조한 변성전분들이 높았다. Cold-Water-Solubility는 측정에서는 드럼건조기를 이용한 멥쌀변성전분이 가장 높았다. 각 시료들의 광투과도는 온도 증가에 따라 일정한 양상을 보이지 않았다. 드럼건조기로 제조한 멥쌀변성전분은 전단속도의 증가에 따라 점조성지수가 급격히 증가하였으며 항복응력도 가장 높은 값을 나타내었다. Gel Permeation Chromatography에 의하면 전분을 변성시킴에 따라 분자길이의 절단과 아밀로오스 분해가 일어남을 알 수 있었으며 X-선 간섭도형측정(XRI)에 의한 간섭도형은 피크를 상실한 V도형의 X-선 회절양상을 보임으로서 결정구조가 무정형으로 변화 된 것을 알 수 있었다.

• 한국미생물·생명공학회지
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• 제20권4호
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• pp.422-429
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• 1992

Maltosy-$\beta$-cyclodextrin는 $\beta$-cyclodextrin에 maltose가 $\Alpha$-1,6 glycosidic bond로 결합된 분지환상결합체로서 pullulanase의 역반응(축합반응)을 이용하여 $\beta$-cyclodextrin과 maltose로부터 합성된다. Maltosyl-$\beta$-cycloextrin의 합성수율을 증가시키기 위하여 각종 water activity depressor인 각종 polyol, sugar 그리고 polyethylene glycol(PEG)등의 첨가의 영향을 검토하였다. 가장 적절한 water activity depressor는 PEG 6000로서, 첨가량 10%(w/w)의 경우 maltosyl-$\beta$-cyclodextrin 생성량과 합성수율은 크게 증가하여 3.02g/100ml 와 55.9%(w/w)로서, 첨가하지 않았을 경우보다 약 1.3배 증가하였다. Water activity는 PEG 6000을 20%(w/w) 첨가할 때 원래의 0.966에서 0.914로 감소하였으며, maltosyl-$\beta$-cyclodextrin 합성수율은 water activity에 반비례하여 증가하였다. Pullulanase의 역반응을 이용한 maltosyl-$\beta$-cyclodextrin 합성반응의 각종 열역학적 상수를 평가하였으며, $\Delta$H는 36.788kJ/mol, $\Delta$S는 0.067kJ/moleK, 그리고 $\Delta$G는 14.433kJ/mole이였다. PEG 6000의 분리회수에 적절한 ultrafiltration membrane의 pore size는 3K dalton이었으며, 여과액과 농축액의 적정 분획비는 1.0 : 9.0였다. Maltosyl-$\beta$-cyclodextrin 합성수율의 증가는 첨가한 PEG가 water activity를 감소시켜 합성된 maltosyl-$\beta$-cyclodextrin이 재분해되는 pullulanase이 정반응인 hydrolysis reaction을 억제하여 equilbrium state에 변화를 주기 때문인 것으로 유추된다.