• Korean Journal of Hydrosciences
• /
• 제8권
• /
• pp.57-68
• /
• 1997

The daily soil water contents were obtained from the time domain reflectometry(TDR) method and energy balance-water budget approach with eddy correlation at the two small semiarid watersheds of Lucky Hills and Kendall during the summer rainy period. There was a comaprison of daily soil water content measured and estimated from these two different approaches. The comparison is valuable to evaluate the accuracy of current soil water content measuring system using TDR and energy balance-water budget approach using eddy correlation method at a small watershed scale. The degree of simiarity between the regressions of these two methods of measuring soil water content was explained by determining the correlations between these methods. Simple linear regression analyses showed that soil water content measured from TDR method was responsible for 58% and 63% of the variations estimated from energy balance-water budget approach with edy correlation at Lucky Hills and Kendall, respectively. The scatter plots and the regression analyses revealed that two different approaches for soil water content measurement at a small watershed scale have no significant difference.

• 한국토양비료학회지
• /
• 제29권3호
• /
• pp.226-235
• /
• 1996

논토양에 무연탄회와 유연탄회를 각각 0%, 15%, 30%씩 시용하고 수도를 유리온실 하에서 pot 재배하면서 투수중의 용탈 성분을 경시적으로 분석한 결과는 다음과 같다. 용탈수중의 pH는 재배구에 비해 무재배구의 pH가 높으며 석탄회 처리구에서 대조구보다 pH가 높았고, 재배구에서는 재배에 따라 서서히 감소되는 경향을 보였다. 침투수중 $NH{_4}^+-N$, $NO{_3}^--N$, K의 용탈은 7월 이후 급격히 감소되며 재배구에서는 거의 용탈되지 않는다. 인산의 용탈은 재배기간 동안 양이 아주 낮으며 규산의 용탈은 재배구에서는 6월이후 급격히 감소되었다. Na는 6월 중순에 가장 용탈량이 높고 그 이후는 서서히 감소되었다. 석회의 용탈량은 재배구가 무재배구보다 용탈량이 많으며 재배에 따라 용탈량이 감소되나 재배후기에도 비교적 높았다. Mg은 7월 중순 이후로 용탈량이 감소되나 재배후기에도 계속 용탈이 일어났다. 용탈수중의 EC는 6월 중순에 가장 높고 그 이후 감소되는 경향이며 석탄회 처리구의 EC가 대조구보다 높았다. 석탄회 처리로 침투수중의 용탈 성분은 크게 증가하지 않았으며 유연탄회와 무연탄회 사이의 차도 뚜렷하지 않았다. 석탄회 처리로 수도의 초기 신장과 분얼이 억제되었으나 후기에는 무효분얼의 억제효과가 기대된다. 석탄회 시용으로 토양의 pH가 상승되었으며 인산 성분이 축적되었다. 그러므로 산성토양의 교정효과는 기대되나 인산 시비의 문제가 있다고 판단된다. 따라서 석탄회 처리는 이식 직전에 시용하는 것보다는 전년도 수확후에 시용하여 우수에 의하여 용탈을 유도한 후라면 크게 염려를 하지에 않아도 좋을 것이며, 용출수에 함유된 무기성분의 양이 무처리와 큰 차를 보이지 않는 것으로 보아 석탄회의 토양시용은 수질오염에 꼭 영향을 주지 않을 것으로 판단된다.

• 한국농공학회:학술대회논문집
• /
• 한국농공학회 1999년도 Proceedings of the 1999 Annual Conference The Korean Society of Agricutural Engineers
• /
• pp.651-656
• /
• 1999

This study was carried out to investigate the paddy soil and water quality in Boryung freshwater reservoir watershed during the non-cropping season. Soil pH of the Boryung freshwater reservoir watershed were 5.39∼5.78. Total-N and P contents were high by the accumulation of chemical fertilizer partly. Heavy metal content of paddy soils were natural background level. Water pH of the Boryung freshwater reservoir watershed ranged from 6.82 to 8.64. Total-N content affected by a livestock wastes and sewage water were the higher than that of others and total-P content showed below 0.1mg/L. Nitrate nitrogen contents was very high according to the influence a livestock waste and sewage water partly. Heavy metal contents of wateers were natural background level.

• Environmental Analysis Health and Toxicology
• /
• 제11권3_4호
• /
• pp.23-32
• /
• 1996

In this study, we investgated the uptake capacity of several water plants for heavy metals (lead and cadmium) in soil of rivers where are adjacent to a industrial complex in Chun-An city and in A-San city. We also examined the deposition pattern of heavy metal in plants. The results are as follows: 1. The soil of river in Chun-An city was polluted more serious than that of A-San city. In Chun-An city, mean values of lead and cadmium contents in soil were 26.224 $\pm$ 28.037 $\mu$g/g, and 0.854 $\pm$ 1. 127 $\mu$g/g, respectively. 2. Water plants examined in this study were Slum suave KITAGAWA, Persicaria thunbergii H. GROSS, Phragmiles japonica STEUD, Echinochloa crus-galli var. frumentacea WIGHT and Persicaria hydropiper SPACH. Both metal contents of several water plants distributed in Chun-An city were higher than those in A-San city. In these plants, Slum suave showed the highest uptake capacity for lead and cadmium. The mean values of lead and cadmium contents in Slum suave were 40.957 $\pm$ 29.577 $\mu$g/g and 1. 930 $\pm$ 1. 076 $\mu$g/g, respectively. Persicaria thunbergii also showed a relatively high uptake capacity for both metal. 3. Correlation between metal contents in soil and water plants was high. In both cases of Sium suave and Persicaria thunbergii correlation coefficients were 0.605 and 0.549, respectively. 4. We analyzed lead and cadmium contents in root, stem and leaf of several water plants. Both metals were mostly deposited in root. Much of both metals were also deposited in leaf. From the results, we suggest that Slum suave KITAGAWA and Persicaria thunbegii H. GROSS can be used to reduce heavy metals from industrial waste water.

• 한국환경교육학회지:환경교육
• /
• 제21권4호
• /
• pp.25-39
• /
• 2008

The purpose of this study is to realize the teaching material, which develops the Model of Watershed Water Environment Education(EE) Textbook, by seeking for a method of the Inquiry with the Perspective of EE and by questing for the contents of watershed water environment necessary for Water EE with the Perspective of EE. First, the value of watershed EE was reilluminated through the literature analysis on the watershed. And 'Inquiry with the Perspective of EE' methodology was newly presented that quests for the contents necessary and proper for EE from the viewpoint of EE. Also, with suggesting it as concept and methodology of 'Inquiry with the Perspective of Watershed EE' by considering the value of EE in Water EE, it presented the content approach direction in the inquiry and the contents of the specific inquiry. Second, through the Inquiry with the Perspective of EE into water environment of the watershed Musim cheon (stream), which is a case region, it allowed the watershed water environment to be able to be synthetically understood. As for a sphere of the inquiry, 5 spheres were sought by taking into account a relation to a human being, as well as the water environment itself of the watershed Musim cheon (stream). Third, Based on the contents of the Inquiry with the Perspective of EE into the watershed Mlisim cheon (stream), 'the Model of Watershed Water EE Textbook' for middle-school students was developed. This model of textbook was selected largely four parts, and was organized with 10 learning objectives and 11 activities.

• Geomechanics and Engineering
• /
• 제18권2호
• /
• pp.189-203
• /
• 2019

Brine leakage is a common phenomenon during construction facilitated by artificial freezing technique, threatening the stability of frozen wall due to the continual thawing of already frozen domain. This paper takes the frequently encountered soft clay in Wujiang District as the study object, and remolded specimens were prepared by mixing calcium chloride solutions at five levels of concentration. Both the deformation and pore water pressure of frozen specimens during thawing were investigated by two-stage loading tests. Three sections were noted from the changes in the strain rate of specimens during thawing at the first-stage load, i.e., instantaneous, attenuated, and quasi-stable sections. During the second-stage loading, the deformation of post-thawed soils is closely correlated with the dissipation of pore water pressure. Two characteristic indexes were obtained including thaw-settlement coefficient and critical water content. The critical water content increases positively with salt content. The higher water content of soil leads to a larger thaw-settlement coefficient, especially at higher salt contents, based on which an empirical equation was proposed and verified. The normalized pore water pressure during thawing was found to dissipate slower at higher salt contents, with a longer duration to stabilize. Three physical indexes were experimentally determined such as freezing point, heat conductivity and water permeability. The freezing point decreases at higher salt contents, especially as more water is involved, like the changes in heat conductivity. The water permeability maintains within the same order at the considered range of salt contents, like the development of the coefficient of consolidation. The variation of the pore volume distribution also accounts for this.

• 한국지반공학회논문집
• /
• 제20권4호
• /
• pp.5-13
• /
• 2004

본 논문에서는 경량기포혼합토의 압축성과 강도 특성에 대해 실험을 통하여 연구하였다. 경량기포혼합토는 재료의 경량화와 압축강도의 증가를 위해 해양준설토에 시멘트와 기포로 구성되어 있다. 이러한 목적을 위하여 초기 함수비, 시멘트 함유율, 실트질 준설토의 혼합을, 구속압조건 등의 다양한 조건에서 준비된 공시체로 일축압축시험 및 삼축압축시험을 수행하였다. 경량기포혼합토의 실험결과, 응력-변형거동과 압축강도는 준설토의 초기 함수비보다 시멘트 함유율에 더 큰 영향을 받는 것으로 나타났다. 또한, 본 연구에서는 초기 함수비, 시멘트 함유율, 기포 함유율을 고려한 정규화계수를 제시하였으며 경량기포혼합토의 압축강도와 정규화 계수와의 유용한 관계를 얻을 수 있었다.

• 한국식품과학회지
• /
• 제10권2호
• /
• pp.105-108
• /
• 1978

This experiment was designed to observe some influence on the serum components in rats by feeding basal diet (Protein contents: 20.0%; lipid contents: 3.5%) with soft water (Water, Carbonated cider, Cola and Fanta). Fourty male Albino rats were used as the experimental animals and the subjects were devided into four feeding group and each group was fed on the corresponding diet for six weeks. The contents of protein, lipid and cholesterol were determined in their serum. The obtained results are summarized as follows. 1) The protein contents in the serum was decreased by the feeding of the Carbonated cider, Cola and Fanta compared with Water experimental group. 2) The lipid contents in the serum was similar to each feeding experimental group. 3) The total cholesterol and ester form cholesterol in the serum were decreased by the feeding of the Carbonated cider compared with Water, but were similar to the feeding of the Cola and Fanta.

• 한국식품영양과학회지
• /
• 제25권3호
• /
• pp.367-373
• /
• 1996

The effects of pine needle extracts on serum and liver lipid contents were evaluated in rats. Thirty male Sprague-Dawley rats weighing 329$\pm$4 were divided into five groups and fed high fat diets for four weeks. Each group was administered with following pine needle extract: control, water ; WE-3, hot water extract(3% PN) ; WE-6, hot water extract(6% PN) ; AE-3, acetone extract(3% PN) ; AE-6, acetone extract(6% PN). Weight gains were significantly lower in WE-6 group than other groups. But there was no significant difference among other three groups. Intakes of diet and water containing the extract and the weights of liver, kidney, heart and spleen were not significantly different among the groups. The contents of serum and liver triglyceride in the WE-3 group were lower than those of control group. The contents of HDL-cholesterol in serum of the WE-3 group was significantly higher than other groups. The value of risk factor index(RFI) was determined to be low especially in case of WE-3 group. Due to pine needle extract administration, concentration of liver total lipid in WE-3 group was significantly lower than that of the control group. These results suggest that the WE-3 may reduce elevated levels of serum and liver lipid contents in rat fed high fat diet.

• 한국수자원학회:학술대회논문집
• /
• 한국수자원학회 1996년도 학술발표회 논문집
• /
• pp.309-317
• /
• 1996