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        검색결과 845

        781.
        2005.10 KCI 등재 서비스 종료(열람 제한)
        아그로박테리움을 이용한 형질전환연구에 기초자료로 활용코자 기내배양중인 땅나리, 하늘나리, 대만나리의 잎절편으로부터 식물체를 유도하였다. 땅나리 잎절편으로부터 다수의 배양체를 얻기 위해서는 MS배지에 0.2 mg·L-1 BA와 0.5 mg·L-1 NAA를 첨가하여 암조건에서 배양하는 것이 효과적이었고, 하늘나리 잎 재분화에는 0.2 mg·L-1 BA와 2.0 mg·L-1 NAA 혼용처리하는 것이 효과적이었으며, 대만나리의 잎 재분화에는 1.0 mg·L-1 BA와 1.0 mg·L-1 NAA 혼용처리가 우수하였다.
        782.
        2005.07 KCI 등재 서비스 종료(열람 제한)
        This study aimed at improving the TiO2 photocatalytic degradation of HA. ·In this study, the Degradation of Humic Acid using Jeju Scoria Coated with WO3/TiO2 in the presence of UV irradiation was investigated as a function of different experimental condition : photocatalyst dosage, Ca2+ and HCO3- addition and pH of the solution. Photodegradation efficiency increased with increasing photocatalyst dosage, the optimum catalyst dosage is 2.5 g/L and Photodegradation efficiency is maximized to WO3/TiO2=3/7. This indicates that WO3 retains a much higher Lewis surface acidity than TiO2, and WO3 has a higher affinity for chemical species having unpaired electrons. The addtion of cation(Ca2+) in water increased the photodegradaion efficiency. But the addtion of HCO3- ion in water decreased a photodegradation efficiency. Photodegradation efficiency increased with decreasing pH. At pH < pzc, the electrostatic repulsion between the HA and the surface of TiO2 decreased.
        783.
        2005.06 KCI 등재 서비스 종료(열람 제한)
        본 조사는 식물상을 밝힘으로서 체계적이고 효율적인 보존관리대책을 마련하데 필요한 정보를 제공하고 우리나라 최남단에 속하는 도서에 있어서 식물자원의 분포특성을 파악하고자 수행하였다. 관속식물은 65과 140속 162종 2변종으로 총 164분류군이었는데 그 중 양치식물은 6과 13속 15종, 나자식물은 1과 1속 1종, 피자식물에 있어서는 쌍자엽식물이 49과 97속 114종 1변종으로 115분류군, 단자엽식물은 10과 29속 32종 1변종으로 33분류군이 출현하여 계 59과 126속 146종 2변종으로 계 148종이었다. 미기록 종은 양치식물 중 점고사리, 쇠고비, 큰족제비고사리, 사다리고사리 등 4종, 단자엽식물 중 강아지풀, 줄, 송이고랭이, 꽃토란, 개구리밥, 부채마 등 6종, 쌍자엽식물 중 큰사방오리, 개모시풀, 애기싱아, 미국자리공, 갯장구채, 새머루, 누리장나무, 보리장나무. 진득찰 등 9종 총 16과 19속 19종이었다. 희귀식물로서는 국내 거문도와 제주도에만 분포하는 것으로 알려진 박달목서가 자생하고 있으며, 바위연꽃의 자생지도 확인되었다. 또한 귀화식물은 총 20과 33속 34종 1변종으로 총 35분류군이었다.
        789.
        2005.04 KCI 등재 서비스 종료(열람 제한)
        Groundwater in Jeju Island, flowing through main stream, is spring water from underground. To set a fixed quantity of groundwater flowing from surface in a hydrological view, 4 downstream (Woedo stream, Gangjung stream, Yeonwoe stream and Ongpo stream) were selected to calculate the characteristic of baseflow and the baseflow discharge through the data on tachometry. There were 11 to 14 level peak caused by runoff, mostly occurred during monsoon season. Also, duration of runoff was 15 to 25 hours, well reflecting the characteristic of inclined, short stream length in Jeju Island and pervious hydrogeographical feature. In case of Gangjung stream, Yeonwoe stream and Ongpo stream, variation of stream water level by baseflow rose above during summer, which was closely linked to the distribution of seasonal precipitation. From autumn to spring, water level fell below while that of Woedo stream remained the same all year round. Data on the water level observed in Woedo stream and Gangjung stream in every single minutes was applied to weir formula(equation of Oki and Govinda Rao) to calculate baseflow discharge. Also, using the data on current and water level calculated in Ongpo stream and Yeonwoe stream, water level-water flow rating was applied to assess baseflow discharge.
        790.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        제주도 알칼리 현무암내에 다양하게 산출되는 단사휘석에 대한 지화학, 조직, 산출상태에 의해 세 종류로 구별되어진다. Ⅰ형의 단사휘석은 상부맨틀을 구성하고 있는 첨정석 페리도타이트의 구성광물로 크롬이 풍부한 투휘석이다. Ⅱ형은 세립의 단사휘석집합체(단사휘석이 거의 85∼90%)로 산출되는 휘석암의 구성광물로서, 모암인 현무암질 마그마의 형성 이전에 상부맨틀에서 형성된 암맥이거나 변성기원의 맨틀물질의 일부가 포획되어진 것으로 Ti함량이 비교적 적은 편이며, Ca, Mg성분이 높은 augite이다. Ⅲ형은 모암인 현무암에서 형성된 큐뮬레이트의 일부이거나 조립의 반정으로 산출되는 휘석이다. 산출상태의 차이에 의해 Ⅲ형은 거정(>1 cm)의 단결정으로 산출되는 단사휘석(Ⅲa), 거정의 사장석 내에 조립의 사방휘석과 함께 오피틱(ophitic)조직을 형성하며 산출되는 단사휘석(Ⅲb), 반정(<1 cm)으로 산출되는 단사휘석(Ⅲc)으로 다시 구분되어진다. Ⅰ형의 단사휘석은 높은 Mg#와 Si, 가장 낮은 Ti 성분을, Ⅱ형은 Ⅰ형과 Ⅲ형의 중간조성을 보이며, 반면에 Ⅲ형의 높은 Ti성분, 낮은 Si와 Mg#를 나타내고 있다. 이는 Ⅰ형에서 Ⅲ형으로 갈수록(Ti+Al<SUP>Ⅵ</SUP>)/Si과 Al<SUP>Ⅵ</SUP>/Al<SUP>Ⅵ</SUP>의 비율이 높아진 것으로, 이 세 종류의 단사휘석은 모두 높은 압력환경 하에서 형성되었으며, Ⅰ형이 가장 높은 압력에서 형성되었고, Ⅲ형이 상대적으로 가장 낮은 압력에서 형성되었음을 의미한다. 모암인 현무암이 고압의 환경에서 분별결정작용을 통해 단사휘석(Ⅲ형)을 정출함으로 SiO₂의 결핍과 상대적인 알칼리성분의 부화를 가져오게 되어 알칼리 현무암의 화학조성을 보이는 특성에 기여한 것으로 해석된다.
        791.
        2004.12 KCI 등재 서비스 종료(열람 제한)
        Atmospheric particulate matters were collected by 8-stage non viable cascade impactor from October 2002 to August at Jeju City. Eight water-soluble ionic components (Na+, NH4+, K+, Ca2+, Mg2+, Cl-, NO3- and SO42-) were analyzed by Ion Chromatography. The concentration of particulate matters and eight water-soluble ionic components were determined to investigate their size distributions. Particulate matters exhibited a tri-modal distribution with peak value around 0.9, 4.0㎛ and 9.5㎛. In summer, the last peak value was lower than other season values likely due to particulate matter scavenged by rain water. Four ionic components (Na+, Ca2+, Mg2+ and Cl-) exhibited a bi-modal distribution in the coarse mode whereas three ionic components (NH4+, K+ and SO42-) in the fine mode, with maximum peak value around 0.9㎛. NO3- was found in both the coarse and the fine mode. The enrichment factor (E.F.) of each ionic components was calculated. Based upon E.F., it is considered that Na+, Cl-, and K+ in coarse paricle mode were delivered form oceanic source, but other components might have other source origins.
        793.
        2004.04 KCI 등재 서비스 종료(열람 제한)
        This study has been performed to clarify the characteristics of temporal and spatial distribution of surface ozone concentration over Jeju Island, one of the cleanest areas in Korea with low emissions of air pollutants. Ozone data are monitored at four sites in Jeju Island. These monitoring sites are located at two urban area(referred to Ido and Donghong), coastal area(Gosan site) and forest site(Chuna site). Ozone data has been routinely collected at these sites for the late four years. The patterns of seasonal cycle of ozone concentrations at all stations show the bimodal with the peaks on spring and autumn and a significant summer minimum. However, the patterns of diurnal variations at rural station, i.e., Gosan and Chuna sites are considerably different to those at urban stations such as Ido and Donghong sites. The patterns of △O3 variations are very similar with those of monthly mean ozone concentrations and △O3 values are exceeded 30 ppb, at urban stations. This may be that urban stations are more influenced by local photochemical reactions rather than rural stations. In order to assess the potential roles of meteorological parameters on ozone formation, the meteorological parameters, such as radiation, temperature, and wind are monitored together with ozone concentrations at all stations. The relationships of meteorological parameters to the corresponding ozone concentration are found to be insignificant in Jeju Island. However, at Gosan and Donghong stations, when the sea breeze blew toward the station, the ozone concentration is considerably increased.
        794.
        2004.03 KCI 등재 서비스 종료(열람 제한)
        To identify the characteristics of wastewater flow generated in treatment basins of Seogwipo-city, we selected 3 stations representing the basin and performed 7 times of field survey including 5 times in dry periods and 2 times in wet periods from Feb. 25 to May 27, 2002 for the selected stations. From the analysis of flow data measured for more than 60 days in the interval of 5 minutes and concentration data obtained from laboratory analysis, we can draw several conclusions. First, in the analysis of diumal variation of wastewater flow for land-use types, we could find the following results: in the residential area, it is observed that wastewater flow rates rise early in the morning for the office-going hour and fall gradually and rise again after the office-leaving hour, showing typical residential wastewater flow pattern, while for the residential and commercial area flow rates rise early in the morning at the office-going hour and move up and down repeatedly within wide range and last till the office-leaving hour, which can be resulted from wastewater that is generated by tourists activated after early in the afternoon, while for the touristy area flow rates rise early in the morning and fall gradually and rise again within wide range. Second, in the analysis of temporal variation of wastewater flow for monthly, it can be observed that in the residential area, in the residential and commercial areas the flow rate of May is higher than that of Feb., March, while for the touristy area flow rate is without monthly because it reflects the movement of population, Third, in wet periods concentration of water-quality item such as SS, BOD, and CODCr is high in the beginning of rainfall by first flush, and falls down gradually to reach the steady state, which is the level of wastewater in dry periods after the cease of storm water due to diluting effect resulting from additional runoff water through storm sewers.
        795.
        2004.03 KCI 등재 서비스 종료(열람 제한)
        This study were conducted to determine the optimum warm casting rate(0, 100, 200, 300, 400, 500㎏/10a) for the yield of food canna in jeju island. The plant height was ranged from 109.4 to 134.7㎝ as organic fertilizer of worm casting increased from 0 to 500㎏/10a, but it was no significance between 400 to 500㎏/10a. Leaf length, leaf width, number of leaves, number of tillers and bulb per plant were shown higher as the amount of worm casting was increased. Stem diameter were the same trend with plant height response. Fresh yield of food canna increased significantly 13.4 to 22.6MT/㏊ as fertilizer rate increased from 0 to 500㎏/10a. Fresh weight of above-ground part and bulb were shown the same trend with fresh yield of food canna.
        796.
        2003.12 KCI 등재 서비스 종료(열람 제한)
        유한요소기법을 이용하여 유동해석의 수치모델을 행하였다 공간을 이산화 할 때에는 Galerkin법을 적용하였으며, 시간의 함수를 이산화 할 때에는 많은 수의 요소와 비정상상태의 문제를 다루는데 있어 장점을 가진 2단계 양해법을 이용하였다. 이동경계조건을 고려한 2차원유통모델을 개발하였고, 직사자형 수조에서 개발된 유동모델을 적용하여 검증하였고, 유용성을 확인하였다. 제주항에 개발된 이동경계기법을 적용하여 계산한 결과, 본 이동경계기법의 좋은 적용성을 보여주었다. 본 연구로부터 이동경계처리 방법이 실해역에서의 유동해석에 있어 유용하고 효율적인 방법이라고 결론지을 수 있다.
        797.
        2003.10 KCI 등재 서비스 종료(열람 제한)
        During the period from April to September 2002, the size distributions of ambient aerosol were measured at the coastal site at Hamduk in Jeju Island. Na+, K+, Mg2+, Ca2+ and Cl- exhibited mostly a bimodal coarse mode size distribution, while ammonium and sulfate were mainly in the fine size range, with maximum at around 0.54㎛. The average molar concentration ratio of ammonium to sulfate for fine particles was equal to 2.0±0.9. Nitrate was evenly found in both the coarse and fine modes. Elements like Al, Fe, Cu, Mg, Na, Ti, Sr and Mn were dominant in coarse particles, with the maximum at around 5.25㎛. S and Pb were mainly in the submicrometer size range. Other elements with a fine and coarse modes were V, Ni, Cu, Ba and Mo. The patterns of the size distributions of trace elements measured at the downtown in Jeju City were very similar to those at the coastal site in Hamduk. However, the amplitude of size fractional concentrations at Jeju City was narrower than that at Hamduk. While the mass median diameters for the chemical species originated from the natural origin such as marine and crust were relatively large, those for ammonium, sulfate, S and Pb were very small.
        798.
        2003.07 KCI 등재 서비스 종료(열람 제한)
        Butyltin compounds (BTs), namely tributyltin (TBT), dibutyltin (DBT) and monobutyltin (MBT), were measured in surface sediments collected in 2001 inside Hallim Harbor where a lot of shipping occurs as one of major harbors of Jeju Island, in order to evaluate their distribution. BTs were detected in surface sediments of all stations and their concentrations were comparable to those in surface sediments of other sites of domestic and foreign countries. The main species among BTs was MBT, although there was a little difference with a survey site. No correlations were obtained between organic matter or particles size of surface sediments and total BTs, indicating that these factors did not affect on the distribution of BTs. It was estimated that more complex factors including BTs loads and surrounding sedimentary environments, affected on the distribution of BTs. The high correlations between BTs indicated that DBT and MBT were mainly degraded from TBT based on antifouling paints of vessel etc. and other sources, such as DBT and MBT, could be ignored. The butyltin degradation indexes ([DBT] + [MBT]/[TBT]) were in the range of 1.5~3.3 (mean 2.5), indicating that the parent compound, TBT, were inflowed into the surface sediments a long years ago and degraded.