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        검색결과 14

        1.
        2019.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        원자력발전소를 운영하게 되면 사용후핵연료와 같은 고준위방사성폐기물이 필연적으로 발생한다. 이러한 고준위방사성폐 기물을 처분하기 위해 심층처분방식이 가장 적합한 대안으로 알려져 있으며 고준위방사성폐기물은 공학적방벽과 천연방벽에 둘러 쌓여 지하 500~1,000 m 깊이의 심지층에 처분된다. 이 중 압축 벤토나이트 완충재는 공학적방벽의 가장 중요한 구성요소이다. 완충재는 처분용기와 자연 암반 사이에 위치해 있기에 주변 지하수 흐름으로부터 처분용기를 보호하고 처분 용기로부터 핵종이 유출되는 것을 저지하는 역할을 한다. 주변 지하수 흐름으로 인한 완충재의 불포화 함수특성 규명은 전체 공학적방벽의 성능을 평가하는데 있어 매우 중요하다고 할 수 있다. 따라서 본 연구에서는 실내 시험을 수행하여 국내 압축 벤토나이트 완충재의 건조밀도, 구속조건 여부, 그리고 건조 및 포화 이력에 따른 압축 벤토나이트 완충재의 함수특성곡선을 도출하여 분석하였다. 구속 조건하에서 건조밀도에 따른 함수특성곡선은 큰 차이를 보이지 않았다. 또한 비구속 조건이 구 속 조건에 비해 보다 큰 수분흡입력을 나타냈으며, 아울러 포화 과정보다 건조 과정에서 보다 큰 수분흡인력이 측정되었다.
        4,000원
        2.
        2014.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Sediment basin that is typical facility installed for development business to prevent soil erosion has low removal efficiency and therefore, it causes complaints from the residents and has a bad effect on ecosystem.Thus there is a limit to control soil erosion using the existing design methods of sediment basin, so the purposes of this study is providing suitable design factors for sediment basin with regarding soil characteristic of development areas and analysing sedimentation characteristic by inflow concentration changes.The results, for analyzing the sedimentation characteristic by soil concentrations within approximately 2,000 ~ 20,000 mg/L of initial SS concentration, indicated similar sedimentation trends for same soil in the supernatant regardless of initial concentrations. However, for different soil characteristic (percent finer), there are different results in sedimentation rate and concentrations of the supernatant.Thus it is recommended that sediment basin to prevent soil erosion during construction should be designed based on retention time derived from soil sedimentation experiments regardless of inlet concentration. In addition, installing the soil erosion prevention facility at the back to satisfy effluent water quality should be considered to minimize soil erosion effectively.
        4,000원
        7.
        2019.08 KCI 등재 서비스 종료(열람 제한)
        This research aims to identify the possibility of developing A horizon resources that can be used for construction and civil engineering work. As such, the utility of A horizon resources was examined by establishing planting ground through a mixture of soil layers and by analyzing the growth and development of Pinus densiflora. The physicochemical and physical properties of the soil were as follows: the A horizon was sandy clay loam, B horizon was sandy loam, and the mixture of two layers appeared as sandy loam, which was identical to the B horizon. The experimental groups did not show any significant difference in their physical properties of porosity and degree of water-stable aggregates. With regards to chemical properties, the A horizon as well as the mixture of A and B horizon showed acidity while the B horizon showed alkalinity. The figures of organic matter, total nitrogen, available phosphate, and replaceable potassium were greater as the A horizon content increased, whereas the figures of replaceable calcium, replaceable magnesium, and conductivity increased as the A horizon content decreased. As a result of the growth and development of Pinus densiflora in each planting ground, the final survival rates were all above 100%. However, the tree height and the rate of growth for the diameter of root were higher in the order of A horizon > A horizon + B horizon > B horizon,indicating that the increased A horizon content is related to the growth and development of Pinus densiflora. The treatment of soil with improvement agents, used to recover the functions of in-situ soil showing poor growth and development, did not have a clear impact on the soil texture and porosity. However, the degree of water-stable aggregates increased significantly when using O horizon as the soil improvement agent among the types of in-situ soil. In contrast, all items related to the chemical properties showed significant differences following the treatment by soil improvement agents. The survival rate according to the treatment of soil improvement agents for the growth and development of Pinus densiflora was higher in the order of organic horizon = no treatment > compound fertilizer > organic fertilizer + compound fertilizer > organic fertilizer; this result was statistically significant with a marginal significance value of the log-rank test(p < 0.05).
        8.
        2018.10 서비스 종료(열람 제한)
        Background : Wild-simulated ginseng (WSG, panax ginseng C. A. Meyer) is known to be grown in high altitudes with a climate of cool, well ventilated and fertile humid forests. In this study, the effects of altitude and soil characteristics on the growth of WSG were investigated. Methods and Results : The seeds were planted on designated line, and the altitude was set at 600 highland and 300 highland. At each highland soil characteristics and forest condition were investigated also Hobo (HOBO U30 Werther station) was set up to measure the microclimate in the site. Experiments were conducted in each highland to determine the difference in the growth of WSG according to the soil condition. Growth characteristics of undergrowth, such as root thickness and length also upper growth such as stem length and thickness were measured. As a result of the soil characteristics survey, the value of available phosphorus was found to be 256.7 ㎎/㎏ at 300 highlands. On the other hand, in 600 highland, available phosphorus was 29.59 ㎎/㎏, which showed big difference. Conclusion : Overall, the cation exchange capacity was higher than the 600 highland at 300 highland. The weight, stem length, root length and leaflet size of the wild-simulated ginseng were higher than those of 600 highland at 300 highland.
        9.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study on the variations of bioactive compounds in ginseng according to the cultivation of soil and the applied fertilizer types (or amount). Therefore, this study aims to examine the variations of 37 fatty acids (FA) and 8 vitamin E (Vit-E) vitamers in 6-year-old ginseng root cultivated in different soil types with different fertilizers regimes. Methods and Results : The profiling of 37 FAs and 8 Vit-E vitamers in 6-year-old ginseng roots was measured by gas chromatography coupled with a flame ionization detector, and then these results were statistically analyzed with chemometrics. The FA and Vit-E content in ginseng roots varied significantly with respect to soil cultivation conditions due to organic fertilizer types and amounts used. Unsaturated FA in ginseng is approximately 2.7 fold higher than the saturated FA. Linoleic, palmitic, and oleic acids were the most abundant FAs found in the ginseng roots. Also, the major Vit-E vitamer found in ginseng root is α -tocopherol. In particular, the application of rice straw compost or food waste fertilizer was increased to create nutritionally-desirable FAs and bioactive Vit-E in ginseng root. In addition, phytonutrient profiling coupled with chemometrics can be used to discriminate the cultivation conditions of ginseng. Conclusion : This preliminary study extends our understanding about the variations of FA and Vit-E in ginseng root depending on cultivation conditions. Hence, these results can be useful as basic information for reliable ginseng production containing high amounts of phytonutrients in a paddy-converted field.
        10.
        2016.05 서비스 종료(열람 제한)
        Background : The Ginseng has been one of the crops that represents Korea, and the main export items in the 1960s, Now it occupies the first exports of agricultural products. The Eco-friendly cultivation of Ginseng was difficult for various reasons. But the cultivation in Green House can be suppressed disease occurrence, when utilizing an environmentally friendly materials has the advantage that can dramatically increase the income by possible organic production. For other crops, it made up a lot of studies on water management, But the studies on water management of ginseng is somewhat lacking. Therefore, this study was conducted to establish appropriate soil- moisture-management-systems within the house of ginseng cultivation. Methods and Results : The type of house is a double steel structure. The first layer was PE film, the second layer was the blue shading net and 75% black shading net. The Soil texture was silt loam and the Soil Series was YEONGOK Series. Install the house on the adjacent paddy soil and upland soil, and planting on April 30, 2011 which was cultivated by the straw mulching. The irrigation start point was the 40, 30, 20kpa, and the end point was treated with 15, 10kpa. Soil moisture measurements were determined by tension meter(Jet Fill) depth 20cm in soil. Growth and Yield Survey was conducted in accordance with the Rural Development Administration (RDA) standard research. Statistical analysis of the results were analyzed using the Microsoft's Excel 2003. Conclusion : In a survey due to differences in soil traits and Irrigation point, from 2 years to 4years of root weight and yield of Ginseng were heavier in the upland, especially 30kpa irrigation point treatment was heaviest than the other treatments. From 5year to 6 Years of ginseng has showed heavier in paddy soil, the most treatment was 30kpa- 15kpa irrigation point. This trend was the same in upland soil. Soil moisture management in the case of silt loam, the humid-state-control was more advantageous than dry-state control in upland and paddy soil.
        11.
        2012.11 KCI 등재 서비스 종료(열람 제한)
        The purpose of this paper is to provide information on planting construction for healthy plant growth. To achieve this purpose, this study analyzed the planting type, planting density, withering rate, soil characteristics, and cambium electrical resistance (CER) of withered trees in an apartment complex with a high withering rate. The major plant groups examined consisted of native broad-leaved tree species (39.3%), native narrow-leaved tree species (24.2%), and native broad-leaved– exotic narrow-leaved tree species (16.4%). The planting density of the green area, where trees were planted from 0.0 to 0.3 trees per unit area, was measured as 98.4%. Withered trees were found in 19 of the 20 planted species, and the withering rate was 41.8% (610 withered/1,461 planted). Withering rates for tree species were measured as follows: Sophora japonica and Salix babylonica (100.0%), Magmolia denudata (84.3%), Lindera obtusiloba (74.7%), cornus kousa (69.3%), acer triflorum (69.2%), diospyros kaki (66.7%), Prunus yedoensis (62.8%), Acer palmatum (52.6%), Prunus armeniaca (51.1%), Chaenomeles sinensis (43.7%), Ginkgo biloba (40.9%), Zelkova serrata (31.0%), Cornus officinalis (28.6%), Taxus cuspidata (25.6%), Pinus densiflora (21.4%), Pinus parviflora (15.2%), Pinus strobus (14.6%), and Abies holophylla (10.3%). Soil chemical analyses for 18 samples revealed that as the withering rate increased, the following occurred: (a) the ratio of silt and clay in soil increased; (b) the soil pH, organic matter rate, nitrogen, available phosphorus, and cation exchange capacity (CEC) in samples were graded as “inadequate,” based on the plant grading evaluation; and (c) the NaCl and cation exchange capacity were evaluated as “somewhat satisfactory.” The measurement of CER for withering rate shows electrical resistance for higher withering rate are higher, which could predict that a tree will not grow well.
        12.
        2012.02 서비스 종료(열람 제한)
        본 연구에서는 정수처리 과정에서 발생하는 정수슬러지를 재활용하기 위하여 우리나라 대표지질인 화강풍화토와 다양한 비율로 혼합하여 다양한 실내시험을 통한 친환경 지반을 개발하고자 하였다. 또한 해양오염 및 해양사고의 원인인 폐어망을 지반보강재로 활용하고자 그 보강효과를 알아보았다. 다짐시험, 삼축압축시험, 투수시험 및 용출시험과 같은 다양한 실내시험이 수행되었다. 시험 결과 정수슬러지의 함량은 혼합토의 단위중량, 최적함수비, 전단강도정수, 투수계수 및 중금속 용출 특성에 중요한 영향을 미치는 인자로 평가되었다. 또한 폐어망의 보강으로 인해 혼합토의 점착력 및 내부마찰각은 증가하는 것으로 나타났다.
        13.
        2011.02 서비스 종료(열람 제한)
        유사정적해석에서 토사비탈면에 작용하는 지진관성력을 유사정적하중으로 대체하기 위해 지진계수가 적용되고 있다. 대부분의 지진계수에 관련된 선행 연구는 지진관성력의 작용방향을(수평, 수직)제한하여 지진계수 크기를 산정하는 데 목적을 두고 제안되었다. 또한, 비탈면 안정해석 프로그램의 입력방법에 따라 지진관성력의 방향을 수직·수평방향으로 구분하여 제한적으로 적용되고 있는 실정이다. 일반적으로, 지진시 토사비탈면의 안정해석에는 위험측면 안정해석을 목적으로 수평방향의 지진관성력만을 고려한다. 그러나 수직방향의 지진관성력과 동시에 적용하는 경우에는 비탈면의 형상(β, H), 지반강도정수(c, Φ), 흙의 단위중량(γ)에 따라 수직방향의 지진관성력 작용방향(상향, 하향)이 비탈면을 안정 또는 불안정하게 만든다. 그리고 비탈면 안정해석에 의해 산정된 안전율에 따라 파괴면의 크기와 유형(사면파괴, 지반파괴)이 달라지기 때문에 위험측면의 지진관성력의 방향 또한 달라진다. 따라서, 수직방향의 지진관성력을 고려할 경우에는 위험측면의 비탈면 안정해석을 하기 위해서 지진관성력 방향을 결정하는 예비해석을 수행하고 비탈면 안정성 평가를 해야 한다. 본 연구는 한계상태 지진관성력의 방향을 결정하기 위해서 수평·수직방향의 지진관성력을 구분하지 않고 합력으로 표현되는 복합지진계수를 이용하여 복합지진관성력의 방향각을 산정할 수 있는 하계해석 프로그램을 수정·개발하였다. 그 결과를 지반범용 해석프로그램(Slope/W)을 이용하여 한계평형해석법(Ordinary법, Bishop법, Spencer법)에 따른 복합항복지진계수의 크기와 방향을 비교·검증하였다. 또한, 한계상태 복합항복지진계수와 방향각을 도출하기 위해서 비탈면의 기울기(β), 안정수(Nc), 마찰계수(tanΦ)와 복합지진계수의 방향각(α)을 매개변수로 하는 한계상태 복합항복지진계수 산정도표를 제안하였다.
        14.
        2003.02 KCI 등재 서비스 종료(열람 제한)
        This paper investigates preliminarily spatial distribution soil organic matter (SOM), nitrogen (N) and phosphorus (P) and its environmental influence in wetland soil of different vegetation landscape in the Yellow River Mouth. The result shows the SOM and total nitrogen (TN), efficient N, efficient P in top layer soils of different vegetation district have significantly different content, The SOM is shown as Calamagrostis epigeios wetlands > Phragmites cmmunis wetlands > Tamarix chinensi wetlands above tidal > Suaeda salsa wetlands in high tidal > Tamarix chinensi wetlands in high tidal > tidal flats, the arrange of the TN and efficient N content is the same except that the content in Suaeda salsa wetlands in high tidal is heavier than Tamarix chinensi wetlands in high tidal. In different vegetation landscape wetland types the vertical change of soil nutrients are obvious except for P, gradually decrease from the upper to the lower. This case reflects the function of the vegetation on the wetland development of soil, and proves the wetland soil has the characteristic of new born and bad degree of development. SOM, TN, efficient N and efficient P content in wetland soils have significantly positive correlation, but TP have no correlation with them but efficient P. The contents of TN in wetland soils range from 58~1480 mg/kg, total average content 408 mg/kg, average content of above 30 cm is 625 mg/kg. The range of TP content in the soil is 372~1042 mg/kg, total average is 569 mg/kg, average content of above 20 cm is 611 mg/kg. According the P it occurs mainly as calcium phosphates, and the validity is lower, therefore, N and P in the new born wetlands cannot produce serious impact on the environments at present.