• 한국환경과학회지
• /
• 제29권6호
• /
• pp.579-603
• /
• 2020

In order to provide fundamental information about the floristic composition of the area along with an assessment of the environmental impact, a floristic study of the vascular plants in the Tamjin River estuary in Gangjin-gun was conducted for a total of nine days, in the period from June 2014 to September 2014. We found that the vascular plants in this region comprised 424 taxa belong to 102 families, 281 genera, 390 species, 5 subspecies, 26 varieties, and 3 forma. Five taxa of Korean endemic plants including Weigela subsessilis (Nakai) L.H.Bailey, Lespedeza maximowiczii var. tricolor (Nakai) Nakai, and Clematis trichotoma Nakai were collected. Two least concern (LC) taxa of rare plants (as designated by the Korea Forest Service) were collected: Hydrocharis dubia (Blume) Backer and Platycladus orientalis (L.) Franco. Ten the floristic regional indicator taxa from the third to the fifth grade were identified: two taxa belonged to grade IV, and eight taxa belonged to grade III. Twenty-four taxa of salt-tolerant plants, including Artemisia fukudo Makino, Carex rugulosa Kuk., and Suaeda glauca (Bunge) Bunge, as well as 44 taxa of aquatic plants, including Najas marina L., Nuphar oguraensis Miki, and Nymphoides indica (L.) Kuntze, were investigated in this region. Fifty-nine taxa of naturalized plants were recorded, among which the following six taxa were plants that caused ecosystem disturbance: Ambrosia artemisiifolia L., Humulus scandens (Lour.) Merr., Lactuca scariola L., Rumex acetosella L., Solidago altissima L., and Symphyotrichum pilosum (Willd.) G.L.Nesom.

• Journal of Forest and Environmental Science
• /
• 제7권1호
• /
• pp.23-34
• /
• 1990

산지유역(山地流域)에 있어서의 토석이동(土石移動)은 체류과정(滯留過程)과 이동과정(移動過程)으로 구분되며, 과거로 부터의 변화과정을 반영하고 있는 현재의 지표면의 특성을 분석하기 위하여는 원인과 결과를 분명히 하여야 한다. 여기서 원인이란 단위시간 안에서 유역특성을 구성하는 요인인 지형(地形), 지질(地質), 기후(氣候), 식생(植生), 토지이용(土地利用) 등을 의미하며, 결과란 유역(流域)안에서 발생하고 있는 산사태(山沙汰), 땅밀림, 하상변동(河床變動) 등을 말한다. 본 연구는 조사대상지인 산지급류하천(山地急流河川)에 있어서 상기 원인중 지형(地形)(하천징지형(河川徵地形))과 식생(植生)(동령임분(同齡林分))을 분석하여 결과로서 존재하는 하상변동(河床變動)을 해석하는데 필요한 기초자료를 얻고저 하였다. 그 결과 하상퇴적지(河床堆積地)의 침입수목의 연륜해석(年輪解析)으로부터 하상변동(河床變動)에 대한 공간적(空間的)(퇴적고(堆積高)) 시간적(時間的)(체류기간((滯留期間)) 분포(分布)에 대한 객관적인 자료를 얻을 수 있었다. 따라서 이를 기초로 하여 유역간(流域間) 또는 구간간(區間間)의 지표변동(地表變動)의 특성(特性)을 시(時) 공간적(空間的)으로 해석하므로서 보다 객관적인 방재대책(防災對策)을 수립할 수 있을 것이다.

• 한국물환경학회지
• /
• 제18권4호
• /
• pp.401-409
• /
• 2002

In this study, to evaluate the applicability of ORP and pH as process control parameters for an intermittent aeration process, a 200L/d bench-scale plant was installed and operated for 90 days. It was fed with synthetic wastewater which contained $COD_{Cr}$ : 400mg/L, TN : 40mg/L and TP : 7mg/L. ORP & pH were measured on-line and compared with the variation of nutrient concentrations. As the results, both of the ORP and pH were able to monitor successfully nitrification and denitrification. Bending-points on the ORP curve and peak points on the pH curve corresponded to the termination of nitrification and denitrification. For P uptake and release, pH was the best indicator for performance evaluation. The aerobic pH apex was appeared when P uptake was accomplished and there was a relationship between the P release and pH variation. But the pH curve needed filtering because there were many noises on it. In this study, the shape of the ORP & pH curves were varied as the operating conditions such as aeration rates and organic loads were changed. It allowed the operating states of biological systems to be effectively evaluated. If it is properly managed to show the bending points and peak points clearly, the on-line monitoring of ORP & pH will be a reliable and effective technique for process control of intermittent aeration processes.

• Asian-Australasian Journal of Animal Sciences
• /
• 제22권4호
• /
• pp.520-527
• /
• 2009

Alfalfa (Medicago sativa L) is a high-quality forage for ruminants and the main stem is the dominant morphological component contributing to the forage nutritive value in mature alfalfa forage. Shearing force, a fracturing property of plant stem, is an important indictor of forage value. The objectives of this study were to investigate the effects of morphological characteristic on shearing force, the relationship between shearing force and chemical composition, and the relationship between shearing force and in situ digestibility of alfalfa stem. The results showed that linear density (weight per unit length of stem) was more important than chemical composition in affecting shearing force. There was a positive relationship between lignin content and shearing force (r = 0.78). Correlations were not found between shearing force and other chemical components such as neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose and hemicelluloses. In situ digestibility (of dry matter and NDF) was related to shearing force. A negative correlation was found between shearing force and dry matter (DM) digestibility (r = -0.70), and there was also a negative correlation between shearing force and NDF digestibility (r = -0.87). When shearing force was standardized for stem diameter or stem linear density, the relationship between shearing force and digestibility was consistent regardless of stem diameter and stem linear density. Shearing force was significantly correlated with lignin content and in situ digestibility (of DM and NDF), and was a more direct indicator for estimating forage nutritive value related to animal performance, so it can be used to predict the forage value of alfalfa.

• 한국약용작물학회지
• /
• 제22권1호
• /
• pp.38-45
• /
• 2014

This study was performed to investigate the physiological responses of Oplopanax elatus by water condition. Drought stress was induced by withholding water for 26 days. The results show that $P_{N\;max}$, SPAD, gs, E and Ci were significantly decreased with decreasing of soil moisture contents. However, AQY and WUE were decreased slightly only at 26 day. This implies that photosynthetic rate is reduced due to an inability to regulate water and $CO_2$ exchange through the stomatal. According to JIP analysis, ${\Phi}_{PO}$, ${\Psi}_O$, ${\Phi}_{EO}$ and $PI_{ABS}$ were dramatically decreased at 21 day and 26 day, which reflects the relative reduction state of the photosystem II. On the other hand, the relative activities per reaction center such as ABS/RC, TRo/RC were significantly increased at 26 day. Particularly, Dio/RC and DIo/CS increased substantially under drought stress, indicating that excessive energy was consumed by heat dissipation. These results of chlorophyll a fluorescence show that the sensitivity changes photosystem II activity. Thus, according to the results, O. elatus was exhibited a strong reduction of photosynthetic activity to approximately 10% soil moisture contents, and JIP parameters could be useful indicator to monitor the physiological states of O. elatus under drought stress.

• 한국작물학회지
• /
• 제29권3호
• /
• pp.280-284
• /
• 1984

콩모자이크 바이러스(SMV)에 의한 갈반립의 형성율과 SMV의 종자전염율을 조사하기 위하여 대두품종 Clark, Woodworth, 북해1호를 재료로 SMV 이병정도와 갈반립율 결협절위 및 갈반립형성등의 관계를 조사하고 그 갈반립을 통한 SMV의 종자전염율을 면역이중확산법과 유묘감염률로 조사하였다. 1. 갈반립의 형성율은 식물체의 이병정도와 정비례적인 상관(r=0.796)을 보였다. 2. 이병식물체의 갈반립형성은 결협절립 및 협중종실위치와 유의상관이 없었으며 (r=0.34), 동일절위 및 협내에서도 갈반립과 비갈반립이 함께 형성되었다. 3. 면역이중확산법으로 조사한 SMV의 종자전염율은 4.2 -33.3％로 비교적 낮았으며 품종에 따라 현저한 차이가 있었다. 4. 유묘에 나타난 SMV 증상으로 조사한 종자전염율은 면역이중확산법으로 검정한 종자감염율보다 약관 높게 나타났으며 이는 항혈청의 역가 또는 Virus의 체내증식과 관계가 있는 것으로 보였다. 5. 이병직물의 갈반립은 SMV 종자전염율과 일치하지는 않으나 SMV의 포장이병율 추정에 유용한 지표가 될 수 있으며 파종시 갈반립의 제거는 SMV 전염원의 감소효과를 가져올 수 있을 것으로 보였다.

• 환경영향평가
• /
• 제12권2호
• /
• pp.87-98
• /
• 2003

The main purpose of this study is to propose the integrated assessment model for the rational and effective selection of proposed sites in National Trust (NT) and conserve the ruined natural environment by excessive land development. The results of this study are as follows; 1) The specialists thought that rare and endangered species were very important in plant and animal, in case of landscape and environment, naturality and water quality were too important. 2) In the result of the correlation measure on the indicator of assessment, 'erosion of soil'and 'air pollutant'was highly correlative. Secondly, 'suspended solids' and 'erosion of soil'was high correlation. 3) In the result of forming the factors into the integrated indicators, they were classified into conditional, stable, valuable and potential factors and the purpose of this formation is to evaluate proposed sites in NT objectively and rationally with organic assessment. 4) In the integrated assessment model, the degree of explanation was observed approximately 36.4% and the important factor was the conditional factor, but we have to consider all factors for the effective and objective assessment. Therefore we organically have to apply and use them for the assessment of proposed sites in NT. It turns out to offer raw data on the land conservation and carry out the role of the instrument of measurement. As for future directions, the follow are proposed: 1) adaptation of real proposed site, 2) verification of effect and problem, 3) practical survey for diverse types as mountain, coast and inland.

• 한국구조물진단유지관리공학회 논문집
• /
• 제22권1호
• /
• pp.56-63
• /
• 2018

이 연구에서는 연성중심의 보강을 위하여 벽체의 양단부에서 경계요소를 형성하는 내진 보강공법이 적용된 벽체의 반복 휨 거동을 평가하였다. 벽체 경계요소에서 구속효과를 위한 횡보강은 프리스트레스트 와이어로프를 사용하였다. 주요 변수는 제시된 단면 확대공법의 보강 높이로 하였다. 최소 보강 높이는 보강 벽체와 기존 벽체의 모멘트 분포의 비교로부터 결정하였다. 실험결과, 제시된 보강방법은 벽체의 휨 강성 및 연성향상에 매우 효율적이었는데, 최대내력 시 강성과 최대내력의 80%지점에서 산정한 일손상지수는 무보강 벽체에 비해 각각 평균 46%와 210% 증가하였다. 보강높이가 벽체의 일손상지수 증가에 미치는 영향은 보강높이가 $2.0l_w$ 이상일 때 중요하지 않았다. 보강된 벽체의 휨 내력은 ACI 318-14에서 제안하는 등가응력블록을 통한 예측 값보다 22% 이상 높았다.

• 한국환경생태학회지
• /
• 제34권2호
• /
• pp.115-120
• /
• 2020

본 연구는 생물 다양성의 지표종인 개미류의 시기별 우점종 및 개체군 변동을 살펴보고, 추후 기후변화에 따른 개체군 변화의 기초자료를 확보하고자 수행되었다. 조사 기간은 2013년 6월부터 9월까지 고도별 조사 지점을 선정하고, 함정트랩을 사용하여 정방형조사법(10m×10m)으로 개미의 분포를 조사하였다. 고도별 조사 결과, 총 3아과 11속 14종 15,466개체가 채집되었다. 낮은 고도(700m)에서 13종 4,548개체의 분포가 확인되었으며, 우점종은 일본장다리개미(49.9%)로 나타났고, 중간 고도(900m)에서 8종 9,129개체가 채집되었으며, 우점종으로 극동혹개미(57.7%)의 분포가 확인되었으며, 높은 고도(1,100m)에서 10종 1,789개체가 확인되었으며, 우점종으로 코토쿠뿔개미(43.3%)가 확인되었다. 고도별로 일본장다리개미, 스미스개미, 극동혹개미는 폭넓게 분포하는 것으로 확인되었다.

• 한국토양비료학회지
• /
• 제49권3호
• /
• pp.235-241
• /
• 2016

The soil does not only serve as a medium for plant growth but also for engineering construction purposes. It is very weak in tension, very strong in compression and fails only by shearing. The behaviour of the soil under any form of loading and the interactions of the earth materials during and after any engineering construction work has a major influence on the success, economy and the safety of the work. Soils and their management have therefore become a broad social concern. A limitless variety of soil materials are encountered in both agronomy and engineering problems, varying from hard, dense, large pieces of rock through gravel, sand, silt and clay to organic deposits of soft compressible peat. All these materials may occur over a range of physical properties, such as water contents, texture, bulk density and strength of soils. Therefore, to deal properly with soils and soil materials in any case requires knowledge and understanding of these physical properties. The desired value of bulk density varies with the degree of stability required in construction. Bulk density is also used as an indicator of problems of root penetration,soil aeration and also water infiltration. This property is also used in foundation engineering problems. While not conforming to standard test procedures, this work attempts to add to the basic information on such important soil parameters as water content, bulk density.