• Title/Summary/Keyword: saline water

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Critical Saline Concentration of Soil and Water for Rice Cultivation on a Reclaimed Saline Soil (간척지 벼 재배시 토양 및 관개수 염의 안전 한계농도)

  • 최원영;이규성;고종철;최송열;최돈향
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.48 no.3
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    • pp.238-242
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    • 2003
  • Reclaimed tidal areas for rice cultivation are irrigated with salt mixed water when there is severe drought. Therefore, we identified the critical concentration of saline water for rice growth on a reclaimed saline soil in Korea. The experiment was conducted at the Kyehwado substation of the National Honam Agricultural Experiment Station (NHAES) during 2001-2002. Two experimental fields with 0.1-0.2% for low soil salinity and 0.3-0.4% for medium soil salinity levels were used. The experiment involved four levels of salt solution mixed with sea water (at 0.1, 0.3, 0.5, 0.7%) compared with a control using tap water in a split-plot design with three replicates. Saline solution was applied only two times at seedling stage (10 DAT and 25 DAT) for 5 days. Gyehwabyeo and dongjinbyeo, japonica rice varieties, were used in this experiment. Plant height and number of tillers sharply decreased in the 0.5% saline water in low soil salinity level and 0.1% in medium soil salinity level. For yield components, panicle number per unit area and percentage of ripened grain dramatically decreased in the 0.5% saline water in low soil salinity and 0.1% in medium soil salinity level. But 1,000-grain weight of brown rice decreased sharply in the 0.5% saline water in low soil salinity and 0.3% in medium soil salinity, indicating that this component was not much affected unlike other yield components. Milled rice yield decreased significantly with saline water level in both low and medium soil salinity. In the 0.7% low saline soil, the yield index was only 36% compared with the control. In medium soil salinity, even the control plot showed only 62% yield index compared with the control in the low soil salinity treatment. Results indicated that the critical concentration of saline water for rice growth in terms of economical income of rice production was 0.5% in low soil salinity and tap water in medium soil salinity.

Nanoparticle Effect on Durability of Carbon fiber/Epoxy Composites in Saline Water Environment (염수환경에서 탄소섬유/에폭시 복합재료의 내구성에 미치는 나노입자의 영향)

  • Kim, Bu-Ahn;Moon, Chang-Kwon
    • Journal of Ocean Engineering and Technology
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    • v.28 no.1
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    • pp.64-68
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    • 2014
  • This study was conducted to investigate the durability of carbon fiber/epoxy composites (CFRP) in a saline water environment. The carbon fiber/epoxy composites were modified to use nanoparticles such as carbon nanotubes and titanum oxide. These hybrid composites were exposed to a saline water environment for a certain period. The weight gain according to the immersion time, a quasi-static tensile test, and micro-graphic characterization were used to investigate the samples exposed to the saline water environment. The weight gains increased with increasing immersion time. The weight gains of the hybrid composites were lower than that for pure CFRP throughout the entire immersion time. The tensile strengths decreased with increasing immersion time. The tensile strengths of the hybrid composites were higher than that of the pure CFRP throughout the entire immersion time. The pure CFRP was observed to be more degraded than the hybrid composites in the saline water environment. Therefore, it was concluded that the addition of nanoparticles to CFRP could lead to improved durability in a saline water environment.

Optimum Water Management Practices for Direct Seeding on Paddy Surface of Saline in Soils in Reclaimed Tidelands (서남부 간척지에서 토양염농도별 벼 담수표면직파 파종전.후 물관리방법)

  • Back, Nam-Hyun;Ko, Jong-Cheol;Nam, Jeong-Kwon;Kim, Bo-Kyeong;Park, Hong-Kyu;Kim, Sang-Su;Kim, Chung-Kon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.52 no.2
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    • pp.204-207
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    • 2007
  • This study was conducted to suggest proper water management practices after and before broadcasting of rice seed on flooded paddy surface at reclaimed saline soil with two different saline levels in Gyehwado Substation of Honam Agricultural Research Institute (HARI) NICS, RDA for two years from 2004 to 2005. The stable seedling stand in low saline soil of 0.1% salinity was obtained by one time of water exchange after soil rotary Whereas in medium saline soilof 0.3% salinity, three times of water exchange was required for the stable seedling stand. Milled rice yield was not affected by frequency of water exchange in low saline soil, while it decreased sharply in one and two times of water exchange compared with three times of water exchange in medium saline soil. Irrigation water immediately after direct seeding increased the number of seeding stand in low saline soil. With the increase in the interval of water exchange after direct seeding, the milled rice yield decreased. Although the continuous water flowing showed the most number of seedling stand and was increased milled rice yield compared with the others interval of water exchange in medium saline soil, the number of seedling stand and milled rice wasn't significantly different up to exchange of two days interval compared with the continuous water flowing.

Temporal and Spatial Variations of water Quality of the Coastal Saline Groundwaters in Jeju Island (제주도 염지하수 수질의 시공간적 변화)

  • 김성수;김대권;손팔원;이창훈;하동수
    • Journal of Aquaculture
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    • v.16 no.1
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    • pp.15-23
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    • 2003
  • We have investigated water quality of the coastal saline groundwaters utilized for fish farms in Jeju Island. The water quality investigation included the spatial observations for 75 fish farms during March-May, 1994 and the hi-monthly observations for both coastal saline groundwaters and seawaters at four fish farms from August 1994 to December 1995. Water temperature of the saline groundwaters ranged from 16 to 18$^{\circ}C$ over the study period. Salinity of the saline groundwaters varied between 20.60 ppt and 34.02 ppt, slightly lower than that of the coastal seawaters(26.47~34.53 ppt). This salinity variation must be associated with local precipitation conditions in Jeju Island. The oxygen saturation for most saline groundwater samples was lower than 80%, ranging from 24.7 to 89.8%. The COD and pH values for the saline groundwaters were similar to those for the coastal seawaters. The concentrations of DIP for the saline groundwaters varied between 0.021 mg/L and 0.121 mg/ L, and seasonal variation of DIP in the saline groundwater ranged from 0.014 to 0.077 mg/L, which were higher than that of the coastal seawaters(0.000~0.015 mg/L). Nitrate in the saline groundwaters accounted for more than 90% of the DIM. The maximum concentrations of ammonia, nitrite, nitrate and DIN in the saline groundwaters were 0.085, 0.012, 2.294 and 2.309 mg/L, respectively. These concentrations of the saline groundwaters were considerably lower than those affected culture organisms. Overall, the saline groundwaters utilized for fish farms in Jeju Island appear to maintain good waterquality for fish farms.

Influence of Panax Ginseng upon Water and Food Intake in Rats (인삼이 흰쥐의 물 및 먹이 섭취에 미치는 영향)

  • Chung, Hyung-Keun;Choi, Soo-Hyun;Suh, Chung-Min
    • The Korean Journal of Physiology
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    • v.7 no.2
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    • pp.21-23
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    • 1973
  • To see if the Panax Ginseng has any influence upon the amount of water and food intake, an experiment was carried out using 30 male rats. The animals were divided equally into the ginseng and the saline groups. For 5 days, animals belonging to the ginseng group received every day 0.5 ml/100g body weight of ginseng extract (4 mg of ginseng alcohol extract in 1 ml of saline), while animals belonging to the saline group received the same amount of saline. After the last medication on the 5th day, each animal was accommodated in a cage which was provided with a food well and a water supplier made of glass tube bent $30^{\circ}$ at the tip. The amounts of water and food consumed in the daytime (from 6 a.m. to 6 p.m.) and at night (from 6 p.m. to 6 a.m. next morning) were measured for 2 days. The ginseng group tended to consume water and food slightly more than the saline group did. However, the difference between the 2 group was far from reaching significancy. The influence of Panax Ginseng upon water and food intake was not evident.

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제주도 동부해안 한동리지역의 수문지질학적 연구

  • 김기표;윤정수;박원배
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2002.09a
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    • pp.9-12
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    • 2002
  • The purpose of this study is to understand the high saline water phenomenon of Handong-ri area in the eastern coast of Jeju Island, were investigate the tidal effect of groundwater level, variation of electric conductivity and temperature, geological logging on the monitoring wells, chemical water quality, and ratios of oxygen istope of groundwater and seawater Results in investigating variation of interface zone of freshwater and saline water represented that the hyaloclastites formed at below groundwater table is developing toward the coast; this area consisted of stratum of good permeability. Hyaloclastites is presumed the main path of the high salinity water There are a lot of movement by the tide at upper layer. Salinity of lower layer spreads to upper up step in proportion to tidal energy. Because of hydrogeological characteristics, Interface zone of freshwater and saline water is made, High salinity of groundwater occur in east coastal area of Jeju Island. Therefore, I think that high saline groundwater phenomenon is natural condition by simple mixing.

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Effects of Saline Irrigation Water on Lettuce and Carrot Growth in Protected Cultivation (관개용수 염도수준에 따른 시설 상추 및 당근의 생육 영향 분석)

  • Jeon, Jihye;Jeong, Hanseok;Kim, Hakkwan
    • Journal of The Korean Society of Agricultural Engineers
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    • v.57 no.4
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    • pp.113-120
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    • 2015
  • The objectives of this study were to monitor and assess the effects of saline irrigation water on lettuce and carrot growth in protected cultivation. One control and 4 treatments with three replications, which were differentiated according to the level of salinity in irrigated water, were employed for each vegetable to assess the effects of the irrigation with saline water. Monitoring results showed that the use of irrigation water containing above a certain level of salinity was found to cause excessive accumulation of salts in the soil as saline irrigation water increased electrical conductivity (EC) and sodium ($Na^+$) content in both lettuce and carrot soil samples, while tap water irrigation used as control decreased the salinity in the samples. The salinity higher than the threshold level of irrigation water was found to reduce the yields of lettuce and carrot, while in less than the threshold level the higher the salinity of the irrigation water increased the yields. The salinity of the irrigation water also appeared to increase the internal salinity of the plant as the $Na^+$ content in plant increased as the salinity of irrigation water increase. Increased $Na^+$ content was analyzed to be able to increase the sugar content in carrot. This study could contribute to suggest water quality criteria for safe use of saline water in protected cultivation, although long-term monitoring is needed to get more representative results.

A Numerical Study on Behavior of Fresh Water Body between Injection and Production Wells with Variation of Fresh Water Injection Rate in a Saline Aquifer (염수 대수층 내 담수 주입양 변화에 따른 주입정과 양수정 사이의 담수체 거동에 관한 수치적 연구)

  • Jeong, Woochang
    • Journal of Korea Water Resources Association
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    • v.48 no.1
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    • pp.23-35
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    • 2015
  • In this study, the behavior of fresh water body between the injection and production wells with the fresh water injection rate in a saline aquifer is numerically analyzed by using a three-dimensional numerical model. 8 injection wells are arranged at equidistant intervals on a concentric circle and one production well is located at the center of this circle. In the case that the fresh water injection rate is relatively small, the fresh water body around a injection well screen is not mixed with neighboring ones and is independently distributed. However, when the injection rate is increased, the size of the fresh water body is continuously increased, and the areas, where saline and fresh water among injection wells are mixed, are appeared. The mixed degree is increased as the injection rate is increased. This phenomenon is identically generated around the production well. Moreover, when the injection rate is increased, the ratio of saline water in and around the production well is decreased.

Hydrogeochemical Characteristics and Occurrences of High-Saline Ground Water at Seocheon Area, Korea (서천 길산천 소유역의 고염분 지하수 수질과 산출 특성)

  • Moon, Sang-Ho;Lee, Bong-Joo;Park, Kwon-Gyu;Ko, Kyung-Seok
    • Economic and Environmental Geology
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    • v.42 no.3
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    • pp.235-246
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    • 2009
  • High-saline ground water, whose eclectrical conductivity value ranges from 12,000 to 21,000 $\mu$S/cm, occurs at the small catchment of Gilsan stream near Geum-river estuary dike. These high-saline ground water comes form three different aquifers consisting of two horizons of sand sediments and one weathered zone with top part of unconformity. For these three aquifers showing mutual independence in terms of hydrogeological and hydrogeochemical connection, we examined characteristics of aqifer occurrences and their water chemistry, and observed and analyzed the fluctuations of the ground water level and electrical conductivity. Our study results indicate that the high-saline characteristics of ground water in this study area should not come from dynamic recent seawater intrusion, but might be due to the fossil saline water included and isolated within the paleo-sediments or weathered zone and their upper unconformity part. This high-saline water seems to be now partially mixed and affected by freshwater in the higher inland reach of Gilsan stream.

The Immuno-modulatory Effect of Root of Asarum sieboldii Miq. Water Extract on OVA-induced Asthma (세신 전탕액 경구투여가 천식 억제 및 면역조절에 미치는 영향)

  • Jo, Seoung Eun;Kang, Jae Hui;Lee, Hyun
    • Journal of Acupuncture Research
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    • v.33 no.1
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    • pp.23-36
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    • 2016
  • Objectives : The aim of this study was to investigate the asthma-suppressive and immuno-regulatory effect of AHCR-HA (Root of Asarum sieboldii Miq. water extract) on OVA (ovalbumin)-induced asthma in mice. Methods : All C57BL/6 mice experimental groups, except the Normal and N-AHCR groups, were sensitized with OVA. The mice in the N-AHCR group and the OVA-AHCR group were treated with water extract of AHCR (1 %) by an oral administration, and the OVA-Saline group were treated with saline solution. Oral dosesof AHCR water extract and saline were administered for 8 weeks, three times a week. Results & Conclusion : The lung weight and total cells in the lungs of the OVA-AHCR group decreased significantly compared with those of the OVA-Saline group. Total leukocytes and eosinophils in BALF and photomicrographs of the OVA-AHCR group decreased significantly compared with those of the OVA-Saline group. The collagen accumulation in the lung sections of the OVA-AHCR group decreased significantly compared with those of the OVA-Saline group. The concentrations of IL-4, IL-5, IL-13 and IgE in BALF and the serum of the OVA-AHCR group decreased significantly compared with those of the OVA-Saline group. The mRNA expressions of $TNF-{\alpha}$, $IL-1{\beta}$, IL-4, IL-5 and IL-13 in the lungs of the OVA-AHCR group decreased significantly compared with those of the OVA-Saline group.