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        검색결과 2,298

        2241.
        1999.10 KCI 등재 서비스 종료(열람 제한)
        In order to determine the changes of sediment facies and metal levels in surface sediments after the construction of Shiwha Lake, surface sediments were sampled at 8 sites located on the main channel monthly from June, 1995 to August, 1996 and analysed for 12 metals (Al, Fe, Mn, V, Cr, Co, Ni, Cu, Zn, Cd, As and Pb) by ICP/AES and ICP/MS. Two groups of sampling sites (the inner lake with 3 sites and the outer lake with 5 sites) are subdivided by the surface morphology; the inner lake is a shallow channel area with a gentle slope, while the outer lake is relatively deep and wide channel with a steep slope which has many small distributaries. After the construction of dam, fine terrestrial materials were deposited near the outer lake, which resulted in the change of major sediment facies from sandy silt to mud. With the deposition of fine sediments in the outer lake, anoxic water column induced the formation of sulfide compounds with Cu, Cd, Zn and part of Pb. Metal (Cr, Ni, Cu, Zn and Cd) contents in sediments increased up to twice within 2 years after the construction of dam. This is due to the direct input of industrial and municipal wastes into the lake and the accumulation of metals within the lake. In addition, frequent resuspension of contaminated sediments in a shallow part of the lake may make metal-enriched materials transport near the outer lake with fine terrestrial materials. As the enrichment of Cu, Zn, Cd and part of Pb in the Shiwha Lake may be related to the formation of unstable sulfide compounds by sulfate reduction in anoxic water or sediment column, the effect of mixing with open coastal seawater is discussed.
        2242.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        An experiment was carried out to find out the changes in morphology, sugars, and α -amylase activity during the priming of rice seeds (Oryza sativa L. cv. 'Ilpumbyeo'). For priming, seeds were soaked in -0.6 MPa PEG solution at 15~circC for 4 days (properly primed) and at 25~circC for 4 and 10 days (over-primed) and dried at room temperature. The size of coleoptile and differentiated leaves of properly primed seeds were bigger and coleoptile was separated from the other part of embryo compared with non-primed and over-primed seeds. As priming of seeds advanced, compound starch grains in the endosperm disintegrated into tiny starch granules, and small holes were found in the tiny starch granules and a cavities developed between embryo and endosperm. The radicle and plumule of properly primed germinating seeds developed faster than non-primed and overprimed germinating seeds. Sucrose, maltose, and raffinose contents of properly primed seeds decreased, while content of glucose and fructose and α -amylase activity increased. However, sugar content and α -amylase activity of over-primed seeds were lower compared with non-primed seeds or properly primed seeds.
        2243.
        1999.06 서비스 종료(열람 제한)
        The construction of the coastal structures and reclamation work causes the circulation reduced in the semi-closed inner water area and the unbalanced sediment budget of beach results in an alteration of beach topography. Among the various fluid motions in the nearshore zone water particle motion due to wave and wave-induced currents are the most responsible for sediment movement. Therefore it is needed to predict the effect of the environmental change because of development and so the prediction of wave transformation dose. The purpose of this study is to introduce the relation between waves wave-induced currents and sediment movement. In this study we will show numerical method using energy conservation equation involving reflection diffraction and reflection and the surfzone energy dissipation term due to wave breaking is included in the basic equation. For the wave-induced current the momentum equation was combined with radiation stresses lateral mixing and friction Various information is required in the prediction of wave-induced current depending on the prediction tool. We can predict changes in wave-induced current from the distribution of wave especially near the wave breaking zone. To evaluate these quantities we have to know the local condition of waves mean sea level and so on. The results from the wave field and wave-induced current field deformation models are used as input data of the sediment transport and bottom change model. Numerical model were established by a finite difference method then were applied to the development plan of the eastern Pusan coastal zone Yeonhwa-ri and Daebyun fishing port. We represented the result with 2-D graphics and made comparison between before and after development.
        2244.
        1999.06 서비스 종료(열람 제한)
        A Numerical model is developed in order to predict cross-shore beach profile change. In this model it is assumed that sediment transport is generated by waves(bed load transport suspended load transport) and undertow which is defined as offshore directional steady flow in the surf zone. In addition wave tank experiments which reproduce storm-surge were performed. By comparing resulting profile of calculation with experiments, the applicability of this method is verified.
        2245.
        1999.06 서비스 종료(열람 제한)
        Mokpo coastal area is connected to the adjacent a long river and two large basins. It is essential for port planning coastal zone management and environmental impact study to analyze the data related to the ship operation and variation of current and water quality due to the development of water area including dredging reclamation and estuary barrage. The Yongsan river estuary weir and Yongam-Kumho basins discharge much of water through water gates for the purpose of flood control and prohibit salt intrusion at the inland fresh water area. To meet this purpose discharge through the gates have been done at the period of maximum water level difference between inner river and sea level. This discharged water may cause the changes of current pattern and other environmental influences in the vicinity and inner area of semi-closed Mokpo harbor. In this study ADI method is applied to the governing equation for the analysis of the changes on current pattern due to discharged water. As the results of this study it is known that the discharging operation causes many changes including the increase of current velocity at the front water area at piers approaching passage and anchorages. Discussion made on the point of problems such as restricted maneuverability and the safety of morred vessels at pier and anchorage. To minimize this influence the linked gate operation discharging warning system and laternative mooring system are recommended.
        2246.
        1999.06 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 탱자의 미성숙배로부터 캘러스 유도와 재분화에 관하여 연구하였다. 탱자 배발생 캘러스들은 3% sucrose와 44.4 μm BA로 처리된 ½MS배지에서 광조사(2,000 1x, 16h)시에 미성숙종자의 배로부터 유도되었으며 식물체 재분화는 MS배지에 5.0 μm BA를 첨가하였을 때 가장 양호하였다. 탱자는 배양2~3주경에 담황색의 캘러스가 유도되었으며 배양5~6주경부터는 딱딱한 녹색의 캘러스로 변하였다. 기내 재분화는 3% sucrose와 5.0 μm BA가 첨가된 MS배지에서 배발생 캘러스로부터 직접 유도되었다. 또한 배양 12주 후에 Multishoot가 재분화되었으며, 배양 16주 후에 뿌리가 형성되었다. 또한 뿌리가 형성된 식물체들은 토양으로 옮겨져 완전한 식물체로 잘 자랐다. 광학 현미경 관찰시 탱자에서는 배양4주경에 하얀색의 조밀한 배양된 세포들이 나타났다. 배양6주경부터는 세포들이 신장되면서 배발생 돌기가 나타났으며 주변의 세포들은 액포화 되었다. 또한 배양12주경에는 미성숙 잎에서 발달된 유낭과 전형성층을 관찰하였다.
        2247.
        1998.12 서비스 종료(열람 제한)
        It is necessary to quantitatively asses the influence of tidal currents to analysis the coastal current patterns before or after constructing offshore structures like as breakwaters. This assesment can be made through the use of simulation models designed to reproduce the water movements of the area. And it is very important to predict a phenomenon of pollutant dispersion in the area. In this study, in order to predict the changes of sea water quality for the port development plan, Ilgwang harbour, located at the east coast of Pusan, the numerical computations were carried out. The flow patterns were investigated before and after the development of the harbour bay and coastal area connected on it. The computational models are an extension of earlier work on the flow which used the ADI Method (Alternating Direction Implicit Method) in appling to Osaka Bay by KANEKO et al. The transport of pollutant constituents depends upon the currental characteristics of the water-transporting medium. In the currental flow model, water velocities and water levels are computed throughout the regions of it. These value are then used in the mass-balance equation to obtain the pollutant-constituent transport. As a result of this research, the present water quality of Ilgwang harbour and the coastal areas connected on it was proved out some good condition. The changes of sea water quality due to the port development plan of the Ilgwang habour bay and the coastal area were not large compared with the present condition, but it will be likely able to get worse by increasing the semi-enclosed areas in the harbour bay. In order to improve the water quality of the area after development, the method to activate tidal exchange in the area can be needed, as a mitigation technique.
        2249.
        1998.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        마늘퓨레를 제조하였을 때 원료로 사용된 마늘의 저장온도와 퓨레의 pH 및 온도가 변색에 미치는 영향을 알아보고 그 원인을 구명하기 위하여 본 실험이 수행되었다. 마늘퓨레의 변색은 저온저장했던 마늘로 퓨레제조시 심하게 나타났으며 pH 4.0, 2와 조건에서 청변이 가장 심하였다. 변색의 양상은 녹변, 청변, 그리고 갈변의 세가지 형태로 나타났으며 산화적 갈변을 제외한 녹변과 청변은 변색정도의 차이일 뿐 같은 기작에 의한 것으로 생각되었다. 변색색
        2250.
        1998.08 KCI 등재 서비스 종료(열람 제한)
        본 연구는 기후 변화가 수자원 시스템에 미치는 영향에 대한 최근의 연구 동향을 살펴보고, 그 중의 한 기법을 미국의 Skagit 시스템에 실례로 적용해 보았다. 적용된 기법에서는, 기후변화로 인하여 Skagit 시스템의 월별 유입량의 평균과 분산이 5% 증가한다고 가정하였다. 평균과 분산이 변화한 각각의 경우에 대하여 월별 운영률을 추계학적 동적 계획법으로 구하고 기후 변화가 없다고 가정한 경우의 운영률과 비교하였다. 그 결과 Skagit 시스템의 월별
        2251.
        1998.06 KCI 등재 서비스 종료(열람 제한)
        The characteristics of the basic statistics and steadiness of wind and the monthly normality test of surface wind distribution are investigated by using the observed wind data compiled from 10m meteorological observation tower at Seocheon district, where is located in the western coastal region of Korea, during the period from Feb. 7, 1996 to Feb. 7 1997. The northerly is appeared to be even in August and Sepember due to the influences of local circulation such as land and sea breeze. The correlation coefficients(γuv) between two wind components are seemed to be positive during the in the period of from June to September and negative from October to April, respectively. The constancy of wind is high in winter and low in summer. It is evident that the modal values of S decrease and their maximum values shifts to lower values with increasing sampling time. It is found from monthly normality test based on the skewness and the excess of kurtosis coefficients that the distribution of zonal wind component is normal in spring and meridional one is normal in late summer and early autumn.
        2252.
        1998.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        This study was conducted to blow the effect of postharvest physiological changes on garlic quality according to its ecotypes and storage temperatures. The changes of water, total soluble solids, crude stein, md total fructans were measured and the rates of respiration and sprouting were analyzed during storage at 20 and 30. The decrease of water content and the increase of total soluble solids were reversely appeared during garlic storage. The crude protein content was gradually increased during storage but total fructan content was decrased. The respiration late was maximized at 60days after storage and the spouting rate was gradually increased. In the aspect of ecotypic characteristics, the water content, fructan content and sprouting rate were higher in 'Namdo' cultivar than those of southern type. The high storage temperature (30) controlled spouting and loss of fructan, and it was effective to maintain the garlic quality.
        2254.
        1998.04 KCI 등재 서비스 종료(열람 제한)
        In this research, two stochastic models are considered to detect and estimate the effect of air temperature change due to industrialization in Ulsan area. Using the monthly mean minimum air temperature anomalies, the data are divided into pre-industrialization part and industrialization one for analysis. The ARMA(autoregressive moving-average) model and intervention model have been applied to the data for the analysis. The results show that the variability of minimum temperature anomalies are very significant in 1989, and also significant in 1971 when the industrialization have started. Therefore, it is stochastically possible to estimate the time when the affection of increase of the temperature concerning industrialization to climate change in Ulsan area has happened.
        2255.
        1998.02 KCI 등재 서비스 종료(열람 제한)
        This paper aims to estimate the change point of the precipitation in Pusan area using the several statistical approaches. The data concerning rainfall are extracted from the annual climatological report and monthly weather report issued by the Korean Meteorological Administration. The average annual precipitation at Pusan is 1471.6 ㎜, with a standard deviation of 406.0 ㎜, less than the normal(1486.0 ㎜). The trend of the annual precipitation is continuously decreasing after 1991 as a change point. And the statistical tests such as t-test and Wilcoxon rank sum test reveals that the average annual precipitation of after 1991 is less than that of before 1991 at 10% significance level. And the mean annual precipitation in Kyongnam districts is also continuously decreasing after 1991 same as Pusan.
        2256.
        1997.12 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 주암호 건설에 따른 기후 요소의 변이에 따른 벼 생산성에서의 변이를 밝히기 위해 주암호 주변 6개 지역에 AWS를 설치하고 그 인근 지역에서 벼를 재배하고 생육 및 수량을 조사하였다. 조사항목은 주요 기상요소로서 일최고기온, 일최저기온, 일평균기온, 일평균상대습도, 일평균풍속, 일평균지온, 일적산일사량 그리고 일적산강우량이었고, 생육형질로는 일주일 간격으로 8~10회에 걸쳐 초장, 분얼수, 엽면적, 엽건물중, 경건물증, 그리고 수량 및 수량구성요소를 조사하였다. 기상요소의 변이와 벼 생산성의 변이간의 관계는 SIMRIW의 모수추정을 통해서 이루어졌으며 호수 생성 전과 생성 후의 기상을 30년간 시뮬레이션을 통해 추정한 다음 이 결과를 모형에 입력하여 30년간의 모형에 의한 수량을 추정하고 그 평균을 통해 호수생성에 따른 벼 생산성 변이를 추정하였다. '94년도 5개 지역 그리고 '95년도 3개 지역, 그리고 '96년도 4개 지역의 관측된 시험 성적과 SIMRIW에서 추정한 지상부 건물중, 엽면적지수 그리고 수량을 비교해 보았을 때 SIMRIW의 결과가 대체적으로 각 관측치의 평균값에 접근함을 알 수 있어 이 모형이 비교적 양호하게 기상환경의 변이에 따른 수량을 예측함을 알 수 있었다. 30년간의 simulation을 통해 얻은 담수 전과 담수 후의 기상자료를 비교해 보면 일최고기온은 담수 전이 약간 높았으나 일최저기온은 담수 후가 약간 높아서 일평균기온은 담수 후가 오히려 높은 경향을 보였고, 일적산일사량은 담수 후에 대략 0.9 MJ d1 정도 낮아졌다. 이들 자료를 SIMRIW에 입력하여 수량을 예측해 본 결과 주 암호의 생성에 따라 복다-동촌-승주지역에서 5.2%, 오봉 4.9%, 이읍 9.1%, 금성 5.5%, 유정 4.8%, 다산 3.3% 정도 수량이 감소된 것으로 나타났다. 전지역을 평균하여 볼 때 담수 전이 6.82MT/ha, 담수 후가 6.44MT/ha로 전체적으로 5.6% 정도 감수한 것으로 나타났다.
        2257.
        1997.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Texture is an important quality factor of processed chestnut products, which changes depending on the conditions of boiling process. The conventional boiling process consists of three stage(1st : 70 minutes at 60; 2nd : 20minutes at 70; 3rd : 80minutes at 98). To improve the conventional boiling process of processed chestnut products, we investigated the changes of texture at different stages of boiling process and undertook the optimization of boiling process by response surface method on heating times of 2nd and 3rd heating, and amount of softening agent. The initial hardness and cohesiveness, the most important textural characteristics of chestnut, were 7.876kg and 0.189, respectively. In the third boiling stage, hardness decreased to 0.313kg and cohesiveness increased to 0.310. Using response surface method the minimum point of hardness and maximum point of cohesiveness was examined and model equations for predicting the changes of hardness and cohesiveness in the optional boiling condition were developed.
        2258.
        1997.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The effect of drying temperature (30, 40, 50, 60) on chemical components of Shiitake mushroom(Lentinus edodss) was investigate. When compared proximate composition on pileus and stipe of raw and dried materials, all of them were found to be higher in the stipe part than in the pileus part. The major components of organic acid were oxalic, citric, malic, malonic and pyroglutaric acid. The contents of free and total amino acids in pileus and stipe were 3458.4, 7640.2mg% for pilueus; 2298.0, 6171.5mg% for stipe on dry basis, respectively. On the other hand, there was no significant difference in the changes of crude ash and organic acids content of Shiitake mushroom among drying temperatures. But the amount of crude fats was increased and that of reducing sugars was decreased with increase of drying temperature. The contents of crude proteins of pileus part of dried materials were increased with increased drying temperature, but those of stile part were gradually decreased. The contents of free amino acids decreased with increase in drying temperature, but those of total amino acids were gradually increased.
        2259.
        1997.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Drying of Shiitake mushroom was investigated to see the effect of temperature, relative humidity of drying air and diameter of the pileus on its rates. The drying rate was increased with the increase of the air temperature and the decrease of the relative humidity. The external color was dark brown at higher drying temperature and higher relative humidity. Exponential and Thompson nodel were found to describe well the raying process of the Shiitake mushroom.