• Geomechanics and Engineering
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• 제31권5호
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• pp.519-527
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• 2022

Shear failure in soil is the primary cause of most geotechnical structure failures or instability. Soil water content is a significant factor affecting soil shear strength. In this study, the shear strength of samples with different water contents was tested. The shear strength, cohesion, and internal friction angle decreased with increasing water content. Based on the variation of cohesion and internal friction angle, the water content zone was divided into a high-water content zone and low-water content zone with a threshold water content of 15.05%. Cohesion and internal friction angle have a good linear relationship with water content in both zones. Environmental Scanning Electron Microscopy (ESEM) test presented that the aggregates size of the compacted loess gradually increases with increasing water content. Meanwhile, the clay in the compacted loess forms a matric that envelops around the surface of the aggregates and fills the inter-aggregates pores. A quantitative analysis of bound water and free water under different water contents using a nuclear magnetic resonance (NMR) test was carried out. The threshold water content between bound water and free water was slightly below the plastic limit, which is consistent with the results of shear strength parameters. Combined with the T2 distributions obtained by NMR, one can define a T2 relaxation time of 1.58 ms as the boundary point for bound water distribution without free water. Finally, the effects of bound water and free water on shear strength parameters were analyzed using linear regression analysis.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2008년도 춘계학술대회 논문집 센서 박막재료연구회 및 광주 전남지부
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• pp.82-85
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• 2008

Polyimide is widely used as a high-temperature insulating material. Space charge distributions in polyimide (PI) films strongly depend upon electric field, temperature, water content and so on. We observed space charge distributions in PI films with various water contents. When a dc field was applied to as-received PI films or water-treated PI films, positive and negative homo space charges were observed near the respective electrodes at 333 K. In dried PI films, the homo space charges were much reduced, and positive and negative hetero space charges in the bulk were clearly observed. The space charge amounts in water-treated PI films were smaller than in as-received ones, while the current density in water-treated PI film was larger than that in as-received one by two or more orders of magnitude. These suggest not only that the charge injection from the electrode is enhanced by absorbed water but also that absorbed water makes carriers mobile. The decay of space charge was also faster in water-treated PI than in as-received or dried one. This also supports the enhancement of apparent mobilities of carriers in PI by absorbed water.

• 한국환경보건학회지
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• 제13권1호
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• pp.7-16
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• 1987

A study was carried out to determine the adequacy of springs as drinking water in summer and in winter separately. In this study, environmental sanitation, physio-chemical examination, bacteriologic contamination and the content of heavy metal were included. For this study, samples were collected from 8 springs which were located in the suburbs of Chunchon city. The following results were obtained. 1. There was the covering system in 1 out of 8 springs. 6 out of 8 springs showed contaminating source within lorn. 2. In physio-chemical test, six out of 8 springs were found to be unsafe for the legitimate standard of safty water. 3. Bateriologic examination clone during summer showed the evidence of coilform group at 7 out of 8 springs and during winter showed positivity at 3 out of 8 springs. 4. In the study for heavy metal content, all places showed high iron level beyond the standard level of salty water, and 4 places showed high contents of fluorine, mangan and lead.

• 생물환경조절학회지
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• 제23권3호
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• pp.199-204
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• 2014

본 실험은 토마토 플러그묘의 접목활착율과 묘소질 향상을 위한 적정 상토 내 수분함량을 구명하기 위하여 수행되었다. 시험구는 접수와 대목의 상토내 수분함량을 각각 3처리구(고, 중 저)씩, 총 9개의 조합을 설계하여 각 처리구별로 접목활착율과 묘의 생육을 조사하였다. 접수의 상토내 수분 함량의 차이는 접목 활착율에 통계적 유의차는 나타나지 않았으나, 대목의 수분함량은 접목활착율에 영향을 미쳐 수분함량이 낮아질수록 활착율도 저하하는 경향을 보였다. 수분 함량에 따른 묘소질도 접목활착율과 유사한 경향을 보여 접수의 수분함량차이는 생육지표에 큰 영향을 미치지 않았으나, 대목에서는 잎(엽수, 엽장, 엽폭)을 제외한 초장, SPAD함량, 경경은 수분함량의 차이에 따라 유의적 차이를 나타냈다. 묘의 충실도는 상토내 수분 함량이 접수는 중간, 대목은 높은 조합에서 가장 좋게 나타났다. 근권부의 생육에서도 대목의 수분함량이 주로 영향을 미쳐, 수분함량이 저하될수록 전 뿌리 표면적, 전 근장, root tip수 모두가 감소되는 것으로 나타났다.

• Journal of Nutrition and Health
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• 제44권4호
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• pp.284-291
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• 2011

The purpose of the present study was to examine the effects of water extracts from red pepper seeds powder on antioxidative enzyme activities and oxidative damage in groups of rrats fed high-fat and high-cholesterol diets group (HFC). The Rrats were divided into the following five experimental groups which are : composed of a normal diet group, a high fat high cholesterol diet group, and a high fat high cholesterol diet group supplemented with different amounts contents (1%, 2% and 4%) of red pepper seeds powder water extracts supplemented groups (HFCW1, HFCW2 and HFCW4, respectively). Body weight gains and food intake were lower ofin the red pepper seed water extracts groups were lower than those inof the HFC group. Hepartic xanthine oxidase (XOD) activity was decreased in the HFCW2 and HFCW4 groups compared to the HFC group. Hepartic glutathione peroxidase (GSH-px) activitiyactivity was increased in the HFCW4 group compared to the HFC group. Hepatic superoxide radicals within the mitochondria and microsomes of cells were significantly reduced in the HFCW2 and HFCW4 groups compared to the HFC group. Hepartic hydrogen peroxide in the cytosol was significantly reduced in the HFCW3 and HFCW4 groups compared to the HFC group. Hepatic carbonyl values in the microsomes and mitochondria were significantly reduced in the HFCW4 group compared to the HFC group. Hepartic thiobarbituric acid reaction substance (TBARS) activity was decreased in the HFCW2 group compared to the HFC group. These results suggest that water extracts of red pepper seeds powder may reduce oxidative damage by activation of antioxidative defense systems in rats fed high fat-high cholesterol diets.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 제38회 하계학술대회
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• pp.1984-1985
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• 2007

Polyimide is widely used as a high-temperature insulating material. Space charge distributions in polyimide (PI) films strongly depend upon electric field, temperature, water content and so on. We observed space charge distributions in PI films with various water contents. When a dc field was applied to as-received PI films or water-treated PI films, positive and negative homo space charges were observed near the respective electrodes at 333 K. In dried PI films, the homo space charges were much reduced, and positive and negative hetero space charges in the bulk were clearly observed. The space charge amounts in water-treated PI films were smaller than in as-received ones, while the current density in water-treated PI film was larger than that in as-received one by two or more orders of magnitude. These suggest not only that the charge injection from the electrode is enhanced by absorbed water but also that absorbed water makes carriers mobile. The decay of space charge was also faster in water-treated PI than in as-received or dried one. This also supports the enhancement of apparent mobilities of carriers in PI by absorbed water.

• 지구물리와물리탐사
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• 제7권3호
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• pp.184-190
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• 2004

불포화대 토양특성 분석을 목적으로 토양단면의 고해상도 영상을 얻을 수 있는 전기비저항 토모그래피를 적용하였다. 전극설치 지점에서 심도별로 채취한 토양시료를 대상으로 토양 공극수의 전기전도도, 수분함량, 이온함량을 측정한 결과, 토양특성과 전기비저항 토모그래피 결과의 상관성이 토성별로 선형적인 관계가 나타남에 따라 전기비저항 토모그래피 결과를 보다 효과적으로 해석할 수 있었다. 따라서 불포화 토양층을 대상으로 한 전기비저항 토모그래피를 이용하여 시추공 사이의 토양특성을 파악할 수 있으며, 토양의 산도, 유기물 함량 등의 간접적 평가가 가능할 것으로 판단된다.

• 한국농공학회지
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• 제42권5호
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• pp.84-93
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• 2000

To provide the basic information for the water improvement and control of water resource in Boryung fresh water reservoir watershed, the characteristics of stream sediments and water quality of the watershed were investigated through 16 times totally, form November in 1998 to March in 2000. The COD values of stream water quality of the Boryung fresh-water reservoir watershed ranged from 0.75 to 6.38. Total -N concentration affected by the livestock wastes and agricultural activity ranged from 0.45 to 21.80mg/L and which was almost over the quality standard of agricultural water(1.0mg/L). Total-P concentration ranged from 0~0.176 mg/L and average value 0.031 mg/L . The contents of heavy metals from 138.4 to 3,457.3mg/kg and total-P were from 210.0 to 468.3 mg/kg. These were very high according to the influence by the livestock waste and sewage water partly.

• 상하수도학회지
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• 제25권1호
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• pp.7-14
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• 2011

This study was motivated by the purpose of improving the O-Index, currently used to quantify water tasty. The authors first develop the M-Index after normalizing Ca, K, and $SiO_{2}$ concentrations in the spring water, in that the concentrations are subject to their log-normal distributions. The M-Index is then compared with the O-Index based on the results of sensory tests, revealing that sensory tests are correlated with the M-Index much more than the O-Index. Furthermore, the developed index is applied to evaluate water sampled from 53 springs in Korea. It is concluded that water, sampled from five most famous springs, has high values in M-Index. In addition, water, collected from springs that are relatively accessible, contains low values, and thus is expected not to tasty good.

• 한국식생활문화학회지
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• 제37권6호
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• pp.510-518
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• 2022

This study compares the quality characteristics of Jeung-pyun prepared by supplementing with rice mash of various cultivars. Results showed high contents of crude protein and crude ash in Saeilmi. The highest and lowest amylose contents were obtained in Goami4 and Baekjinju, respectively. Saeilmi had the highest water absorption index (WAI) of rice flour, whereas the highest water-soluble index (WSI) was obtained in Baekokchal. Maximum viscosity, minimum viscosity, and breakdown were high in Baekjinju, and high cooling viscosity and setback levels were determined in Goami4. The sugar content, total free sugar, and pH of the rice mash were highest in Baekjinju. The highest volume of Jeung-pyun was obtained with Saeilmi supplementation, whereas the specific volume was highest in Baekokchal. Evaluation of L, a, and b color values of Jeung-pyun revealed the maximum L value in Saeilmi, a value in Goami4, and b value in Baekjinju. The physical properties of Jeung-pyun were lower in all supplemented groups compared to the control group for hardness, adhesiveness, and chewiness. The lowest chewiness was obtained in Baekokchal-supplemented Jeung-pyun. We conclude that supplementation with different varieties of rice affects the quality characteristics of Jeung-pyun, which are important factors for manufacturing processed foods.