• 한국양식학회지
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• 제14권2호
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• pp.81-87
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• 2001

Antimicrobial activity of the essential oil extracted from plants Artemisia princeps var. orientalis, Thuja orientalis and Chamaecyparis obtusa were tested against selected pathogenic bacteria and fungi of fish. At the concentrations above 500ppm, ingibitory effect of the oil of A. princeps var. orientalis was at its peak against Aeromonas hydrophila ATCC 14715, A. hydrophila CF-2, A. salmonicida ATCC 14174 and A. salmonicida EL-1 but the bacteria Edwardsiella tarda KBF-1, Vibrio anguillarum ATCC19264, V. ordalii ATCC33509 and Streptococcus sp. were insensitive. Likewise, the oil extract of T. orientalis showed the highest inhibitory activity against V. ordalii ATCC33509, E. tarda ECK-1, and E. tarda KBF-1 at 300ppm; however the activity was highest at 500ppm or A. hydrophila ATCC14715, A. hydrophila CF-2, A. salomonicida ATCC14174, A. salmonicida EL-1 and Streptococcus sp. SF-1. With increasing dose of C. obtusa oil, the inhibitory activity became more and more effective against A. hydrophila CF-2, A. salomonicida ATCC14174, E. tarda ECK-1 and Streptococcus sp. SF-1, but A. hydrophila ATCC14174, A. salmonicida EL-1, E. tarda KBF-1, V. anguillarum ATCC19264, V. ardalii ATCC33509 and gram positive bacteria (Streptococcus sp.) were somewhat resistant. A. princeps var. orientalis, T. orientalis and C. obtusa were also tested against Saprolegnia sp. at the oil concentrations of 10, 100, 500, 1,000, 1,500 and 2,000ppm. The inhibitory effect of the oil on the inhibit the mycelial growth of Saprolegnia sp. at 10ppm and completely inhibited at over 500ppm.

• Nuclear Engineering and Technology
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• 제45권1호
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• pp.1-12
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• 2013

This paper describes the radiation doses to human and non-human biota in the Republic of Korea, as a result of the Fukushima nuclear accident. By using the measured airborne activity and ground deposition, the effective and thyroid doses of five human age groups (infant, 5 years, 10 years, 15 years and adult) were estimated by the ECOSYS code, and the whole body absorbed dose rate of the eight Korean reference animals and plants (RAPs) was estimated by the K-BIOTA (the Korean computer code to assess the risk of radioactivity to wildlife). The first-year effective and thyroid human doses ranged from 5.7E-5 mSv in the infant group to 2.0E-4 mSv in the 5 years group, and from 5.0E-4 mSv in the infant group to 3.4E-3 mSv in the 5 years group, respectively. The life-time (70 years) effective and thyroid human doses ranged from 1.5E-4 mSv in the infant group to 3.0E-4 mSv in the 5 years group, and from 6.0E-4 mSv in the infant group to 3.5E-3 mSv in the 5 years group, respectively. The estimated maximum whole body absorbed dose rate to the Korean RAPs was 6.7E-7 mGy/d for a snake living in soil (terrestrial biota), and 2.0E-5 mGy/d for freshwater fish (aquatic biota), both of which were far less than the generic dose criteria to protect biota from ionizing radiation. Also, the screening level assessment for ERICA's (Environmental Risks from Ionizing Contaminants: Assessments and management) limiting organisms showed that the risk quotient (RQ) for the estimated maximum soil and water activity was significantly less than unity for both the terrestrial and freshwater organisms. Conclusively, the radiological risk of the radioactivity released into the environment by the Fukushima nuclear accident to the public and the non-human biota in the republic of Korea is considered negligible.

• 한국물환경학회지
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• 제32권5호
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• pp.465-474
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• 2016

Since Gyungan stream is included in the protected zone of the water supply source of the Metropolitan area in Korea, the water quality needs to be continuously managed. Therefore, a measure is required that can inhibit the flow of water pollutant into the water body and facilitate the ecological restoration of riparian vegetation. A field survey was conducted on the hydrological characteristics of the landscape elements established on the downstream catchment of the Gyungan stream, the result of which showed that the paddy field and urbanized area can be regarded as point pollution sources. The upland field can be regarded as a non-point pollution source. In order to improve the water quality in the Paldang lake, we first recommended creating a riparian vegetation belt. We also suggested introducing a treatment wetland and an artificial plant island to places in which the creation of a riparian vegetation belt is not ensured. We recommend creating a treatment wetland equipped with diverse functional groups. For creating the plant island, we recommend Zizania latifolia and Typha orientalis, which showed the highest productivity among aquatic plants. The former could be introduced around the outlet of a paddy field and the estuary of tributaries, while the latter could be introduced to a water body directly sourced from mountainous land.

• 한국환경과학회지
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• 제8권1호
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• pp.115-123
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• 1999

수영하수처리장 방류수의 해중방류법과 3차 처리 시설 설치의 비용분석을 한 결과는 다음과 같다. 1) 해안에서 4km 거리와 관경을 2m의 해중방류법을 이용한 수용만의 수질을 개선시키는데 소요되는 해중방류관 건설비용은 383억 원이 소요되는 것으로 산출되었다. 2) 수영하수처리장의 유출수를 해중방류관을 통해서 방류할 경우 방류수심을 32m, Diffuser의 길이를 200m로 할 경우의 초기희석배율은 유속에 따라서 56.4∼399.2으로 계산되었다. 3) 질소를 제거하기 위한 순환법의 경우의 20년 동안의 총 비용은 1,364억 원, 인을 제거하기 위한 응집제 첨가 활성슬러지법은 1,010억 원, 해중방류법은 383억 원으로 해중방류법이 3차 처리시설을 설치하는 비용보다 약 2.6∼3.5배 비용을 적게 소요하는 것으로 산출되었다. 4) 해중방류법을 이용할 경우의 수영만의 수질영향을 예측하기 위해서 물질순환모델을 이용하여 예측한 결과 수영만의 수질이 COD, 용존무기질소(DIN)와 용존무기인(DIP)의 전 항목에서 해역환경 II등급을 만족하는 것으로 예측되었다.

• Journal of Ecology and Environment
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• 제43권4호
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• pp.461-468
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• 2019

Background: This study aimed to identify NO₃^--N sources using the stable isotope δ¹⁵N in Chydorus sphaericus (OF Müller), to investigate hydrological characteristics and nutrient states in artificial wetlands near the Nakdong River. Chydorus sphaericus is dominant in wetlands where aquatic plants are abundant, occurring in high density, and is sensitive to wetland water pollution, making it suitable for identification of NO₃^--N sources. Results: NO₃^--N sources for each wetland were strongly dependent on hydrological characteristics. Wetlands with sewage or rainfall/groundwater as their main sources had high levels of NO₃^--N, whereas wetlands with surface water as their main input had comparatively lower levels. Since wetlands with sewage and rainfall/groundwater as their main water sources were mostly detention ponds, their inputs from tributaries or the main river stream were limited and nutrients such as NO₃^--N easily become concentrated. Changes in NO₃^--N levels at each wetland were closely associated with δ¹⁵N of C. sphaericus. Interestingly, regression analysis also showed positive correlation between δ¹⁵N of C. sphaericus and NO₃^--N level. Conclusions: We conclude that the nitrate stable isotope (δ¹⁵N) of C. sphaericus can be used to elucidate the hydrological characteristics of riverine wetlands. This information is important for maintenance and conservation of artificial wetlands at the Nakdong River.

• 한국자원식물학회지
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• 제24권4호
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• pp.395-403
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• 2011

본 연구는 제주고사리삼 자생지의 입지환경과 식생 특성을 파악하기 위하여 이루어졌다. 각 자생지들은 자생지의 깊이, 암석 노출 비율, 우점 수종, 주변식생 등에 따라 2가지 유형으로 구분되었으며, 이에 따라 자생지의 식생이 다르게 나타났다. 암석이 노출된 유형의 자생지는 인접 지역과의 지형적인 경계가 뚜렷하고, 대부분 습한 환경에 자라는 수목으로 구성되어 있다. 이에 비해 토양이 풍부한 유형의 자생지는 깊이가 얕고, 토양이 발달되어 있으며 주변에서 이입된 수목이 분포하였다. 하지만, 초본층은 대부분 수생식물이 우점하며 이는 자생지가 습지의 특성을 갖는다는 것을 보여준다. 따라서 제주고사리삼 자생지는 소택지와 매우 유사한 특성을 가지며, 제주고사리삼의 보존을 위해서는 자생지가 이러한 습지의 특성을 유지하도록 하는 것이 매우 중요할 것이다.

• 한국환경보건학회지
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• 제23권4호
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• pp.115-120
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• 1997

The purpose of thesis was to investigate the removal efficiency of surfactants and commercial detergents by Oenanthe javanica that is one of aquatic plants in Korea. The experiment is concerned with measuring the concentrations of surfactants and commercial detergents in different media: 1) in pure water, 2) in water containing Oenanthe javanica, 3) in water containing Oenanthe javanica and commercial nutrients. The surfactants used in this research include linear alkylbenzene sulfonates (LAS), $\alpha$-sulfo fatty acid methyl esters(MES), and alkylbenzene sulfonates(ABS). Two commercial detergents designated as A and B were in the forms of power and liquid. The results showed that LAS and MES were more effectively removed by Oenanthe javanica probably because these have a chain of linear carbon than on ABS with a branched carbon structure. In the case of commercial detergents, when the except was performed on the basis of surfactants proportion, the removal trends were similar to LAS and MES. The 5-day cultivating test with initial concentration of 0.5-1.0 ppm surfactants showed that less than 10% was removed if no nutrients an Oenanthe javanica were added. When Oenanthe javanica was added into the sample solution containing surfactants, the removal efficiency was increased 100% for the solution containing 0.5-1.0 ppm 60-70% for 5-10 ppm. In addition, chlorisis on Oenanthe javanica was observed due to surfactants and commercial detergents for all three cases. To test the dependence of population density on nutrients, the initial population density was made 300 g/0.4 m$^2$. Throughout the 5-day experiment, the on Oenanthe javanica grew 20-25% with 0.5-1.0 ppm without the synthetic nutrients but by 5% with a high concentrations of 5-10 ppm. The population density was appeared to be independent of synthetic nutrients. The leaves were to be grown with synthetic nutrients, while roots were grown without synthetic nutrients. Based on this research, the fundamental data concerning cultivation and an adequate adjustment of the water condition can provide for the utilization of Oenanthe javanica in real water treatment system.

• Ecology and Resilient Infrastructure
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• 제2권2호
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• pp.154-160
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• 2015

본 연구에서는 현지조사를 통해 식생의 하안 퇴적과 침식 경감을 판단하였다. 달뿌리풀은 임계유속 1.0 m/s-1.2 m/s을 기준으로 0.2 m 정도의 하안 퇴적과 0.3 m-0.4 m의 침식 경감 기능을 발휘하였다. 갈대는 임계유속 0.6 m/s-0.7 m/s을 기준으로 0.1 m-0.4 m의 하안 퇴적과 0.2 m-0.3 m의 침식 경감 기능을 발휘하였다. 갯버들은 임계유속 1.2 m/s-1.4 m/s을 기준으로 0.1 m-0.2 m의 하안 퇴적과 0.4 m-0.5 m의 침식 경감 기능을 발휘하였다. 물억새는 임계유속 0.6 m/s-0.7 m/s을 기준으로 0.1 m-0.4 m의 하안 퇴적과 0.1 m-0.2 m의 침식 경감 기능을 나타내었다. 조사 대상 식생 중 갯버들이 가장 높은 하안 침식 경감 기능을, 물억새가 가장 낮은 침식 경감 기능을 발휘하였다. 그러나 현지조사 결과 대상 식물종 모두 하안 퇴적 및 침식 경감 기능을 발휘함으로써 안정하도 형성에 기여함을 알 수 있었다.

• Journal of Crop Science and Biotechnology
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• 제10권2호
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• pp.57-63
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• 2007

Due to the strong influence of nitrogen(N) on plant productivity, a vast amount of N fertilizers is used to maximize crop yield. Over-use of N fertilizers leads to severe pollution of the environment, especially the aquatic ecosystem, as well as reducing farmer's income. Growing of N-efficient cultivars is an important prerequisite for integrated nutrient management strategies in both low- and high-input agriculture. Taking maize as a sample crop, this paper reviews the response of plants to low N stress, the physiological processes which may control N-use efficiency in low-N input conditions, and the genetic and molecular biological aspects of N-use efficiency. Since the harvest index(HI) of modern cultivars is quite high, further improvement of these cultivars to adapt to low N soils should aim to increase their capacity to accumulate N at low N levels. To achieve this goal, establishment and maintenance of a large root system during the growth period may be essential. To reduce the cost of N and carbon for root growth, a strong response of lateral root growth to nitrate-rich patches may be desired. Furthermore, a large proportion of N accumulated in roots at early growth stages should be remobilized for grain growth in the late filling stage to increase N-utilization efficiency. Some QTLs and genes related to maize yield as well as root traits have been identified. However, their significance in improving maize NUE at low N inputs in the field need to be elucidated.

• 대한환경공학회지
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• 제39권2호
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• pp.59-65
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• 2017

본 연구에서는 식품과 화장품 재료로 다양하게 이용되는 천연다당류의 특성인 분자구조, 분자량, 점성, 친수성, 팽윤 및 습윤/보습 등을 이용하여 $PM_{10}$에 대한 먼지 억제제를 제조하였고 Lab과 Field Test를 통하여 다양한 먼지 제어 효과를 확인하였으며 대조군인 물에 의한 단순 살수와 합성 PVA보다 우수한 결과를 도출하였다. 또한, 수분 증발 비교, 배추씨 발아와 배추 생장 비교실험(Pot Test), 물고기와 수생식물에 대한 영향 및 허브 식물 성장에 대한 영향 등의 토양 및 수질 시험 등을 통하여 토양과 수질에서의 안전성 등을 연구하여 Polysaccharides를 이용한 $PM_{10}$ 먼지 억제제의 이용 가능성을 확인할 수 있었다.