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        검색결과 656

        604.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to examine the physiological and biochemical responses against UV-B radiation in the seedling of 15 different rice cultivars, having the different physiological sensitivities. Out of 15 rice cultivars tested, moderate and susceptible groups showed significant decreases in biomass and RGR (relative growth rate). Contents of total chlorophyll were reduced remarkedly by irradiation of UV-B. In all rice cultivars tested, the content of chlorophyll a was strongly decreased, while the contents of chlorophyll b were slightly reduced without showing clear different among three groups and 15 cultivars. Carotenoid content was largely reduced by UV-B radiation, whereas polyamine content was moderately increased. The contents of MDA (malondialdehyde) that reflect the level of lipid peroxidation of cell membranes were clearly increased by UV-B stress, showing higher content in susceptible cultivars than moderate and torelant cultivars. The physiological important parameters highly related to visible injury were leaf color, chlorophyll, carotenoid, and lipid peroxidation, whereas biomass and polyamines were not closely correlated. Based on this results, it was concluded that changes of visible injury and the contents of chlorophyll and MDA could be adequately applied and utilized as physiological indicators to UV-B radiation
        605.
        2005.03 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study is to explore the concept of a logistics hub, identify key factors and milestones for its development, and give some recommendations and implications to developing countries. For this the countries competing to be Logistics hub in Northeast Asia (NEA), such as South Korea, japan and China, are taken into consideration These countries have under its priority policies the development of a logistics hub vision to become the central area of the region achieving microeconomic and macroeconomic prosperity. Based on the review of the relevant literature, five factors came up as key determinants for the development of a hub project: 1. Logistics services support and infrastructure. 2. Business environment. 3. Economic determinants. 4. Political support and 5. Access to international markets. These are going to be analyzed together with its different variables, using statistical methods.
        607.
        2004.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In order to vitrify the combustible dry active waste (DAW) generated from Korean Nuclear Power Plants, a glass formulation development based on waste composition was performed. A borosilicate glass, DG-2, was formulated to vitrify the DAW in an induction cold crucible melter (CCM). The processability, product performance, and volume reduction effect of the candidate glass were evaluated using a computer code and were measured experimentally in the laboratory and CCM. The glass viscosity and electrical conductivity as the process parameters were in the desired ranges. Start-up and maintaining glass melt of the candidate glass were favorable in the CCM. The product of the glass product such as chemical durability, phase stability, and density was satisfactory. The vitrification process using the candidate glass was also evaluated assuming that it was operated as economically as possible.
        608.
        2004.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        원자력발전소에서 발생하는 이온교환수지와 가연성잡고체 혼합폐기물을 유리화하기 위하여 유도 가열식 저온용융로를 이용한 실증시험을 수행하였다. 금속 티타늄 고리(Ti-ring)를 이용한 유리의 초기점화에 필요한 에너지는 약 290 kWh로 평가되었다. 혼합폐기물의 투입 중 고주파발생기의 출력은 160∼190 kW로 임피던스는 0.55∼0.65 범위 내에서 안정적으로 유지되었다. 이온교환수지 단독투입 시 보다 가연성잡고체와 혼합 할 경우 CO 발생농도는 1/40 정도로 낮아졌는데, 이는 1.8배 정도 높은 연소에너지를 갖는 가연성잡고체가 혼합폐기물의 완전연소를 유도한 것으로 평가되었다. 혼합폐기물의 공급량에 적당한 최적 산소 버블링에 의해 유리 용탕 내부로의 미연폐기물의 함침은 발생하지 않았으며 유리 용탕은 지속적으로 공정 건전성을 유지하였다. 유리 용탕의 부피가 증가하는 팽창(swelling) 현상 때와 정상 일 때 발생가스를 측정, 비교한 결과 swelling 현상 때는 NO와 같이 환원성 가스의 농도 보다 산화성 기체인 의 농도가 높은 것으로 나타났다. 실증시험에 사용된 이온교환 수지와 가연성잡고체의 각각 투입량은 368kg과 751kg 이었으며, 74 정도의 감용비를 달성하였다.
        609.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        In plants, nitrogen is the major component for growth and development. Leaf growth is based on the division, elongation and maturation of cells, which are used for making of epidermis, mesophyll, bundle sheath, xylem, phloem and so on. Dynamics of these tissues with respect to nitrogen are required for better understanding. This experiment was conducted to evaluate effect of nitrogen on the elongation of epidermal and guard cell of two rice (Oryza sativa L.) varieties, Seoanbyeo and Dasanbyeo on May 2000 at Chungbuk national university in Cheongju. After transplaning the 20-day-old seedlings into a/5000 pots, the main characteristics related with cell elongation were investigated and evaluated. A maximum. leaf length reached at 7 or 8 days after emerging from the collar, and also the leaf elongation rates were greatly affected by the increase of N application rate. The initial and final cell length were about 17~mu~textrmm and 130~mu~textrmm , respectively. Cell divisions occurred within 1.0mm from leaf base. With die higher nitrogen application rate of 22 kg-N 10~textrma-1 , cell division per hour was greater 1.5 to 1.9 and 1.2 to 1.3 fold as compared to the N application rate of 0 and 11 kg-N 10~textrma-1 , respectively. Cell enlargement of epidermal and guard cell under higher N application rate (22kg-N 10~textrma-1 ) was finished within about 20 (Seoanbyeo) and 15 hours (Dasanbyeo), while it took much time, about 30 hours.
        610.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        In order to investigate low molecular antioxidants synthesized by enhanced UV-B radiation, we used the seedlings of two rice varieties. Woonjangbyeo, UV-tolerant, and Hwajoongbyeo, UV-susceptible, were subjected under supplemental UV-B irradiation. When rice seedlings were irradiated with UV light for short period, biosynthesis of total phenolic compound, ascorbate and glutathione were momently reduced. With an increase of UV-B radiation, however, those were slightly synthesized. The content of lipid peroxides in UV-challenged rice leaves was considerably increased after 12 hrs of UV-B treatment. Lipoxygenase activity under supplemental UV-B radiation was differently responded on rice varieties.
        611.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        This paper is aimed to develop a mathematical model for making the forecast information of typhoon's movement such as the estimated movement direction and positions after 24 and 48 hours. The proposed model calculates such kind of information of a typhoon by similar past typhoon's track data which are selected with three similarity criteria among the database of typhoons' tracks for past fifty years. We carried out a simulation forecast with No.14 typhoon formed in 1997, and found that the results of the proposed model were reasonable and it would be suitable for a simulation system for training mariners so that they can take suitable actions to evade the typhoons.
        612.
        2004.06 KCI 등재 서비스 종료(열람 제한)
        This paper tries to draw some implications for Korean seaports in terms of management and development of ports with respect to attracting more transshipment container cargoes. For this the results of the Origin-Destination(O-D) analysis between major Korean ports and top 20 Chinese ports were presented. They also contained the O-D analysis between Chinese major ports and their inland hinterlands.
        617.
        2004.04 KCI 등재 서비스 종료(열람 제한)
        A new light pink colored standard rose (Rosa hybrida Hort.) cultivar “Temperla” was developed at the Jeollanamdo Agricultural Research and Extention Services (JARES) after seedling and line selection in 1999, and its characteristics were examined two time
        618.
        2004.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        원전에서 발생된 중저준위 방사성 폐기물의 경우 처분장으로 이송되기 이전에 드럼에 대한 세부적인 정보 특히 핵종 재고량에 대한 평가가 수행되어야 한다. 그러나 드럼처리된 방사성폐기물의 경우 평가 대상 핵종 농도에 대한 예측이 어려운 것이 일반적이다. 따라서 이를 극복하고자 직접측정이 어려운 경우 척도인자 방법을 활용하고 있다. 국내의 경우 1996년부터 고리원전에서 척도인자 개념이 적용된 핵종분석장치를 운영해오고 있다. 그러나 고리원전에 적용된 척도인자의 경우 많은 개선의 여지가 남겨져 있다. 따라서 현재 척도인자의 향상을 위한 연구가 진행 중에 있다. 본 논문에서는 연구의 범위에 대한 개략적인 소개와 핵종 재고량 평가 방법 중 보다 신뢰할 수 있는 평가 방법을 찾고자 통계적인 척도인자 평가 방법을 비교 평가했으며 이를 통해 고리원전에 사용된 산술평균 방법을 기하평균 방법으로 바꾸는 것이 예측의 정확성을 향상시킬 수 있을 뿐만 아니라 드럼내 핵종 재고량의 과대평가를 막고 합리적인 보수성을 유지할 수 있음을 알수 있었다.
        619.
        2003.12 서비스 종료(열람 제한)
        The shoot tip and young leaf of Rhodiola sachalinensis were cultured to invest the plant growth regulator condition for callus induction, shoot and root regeneration. When the shoot tip was sterilized in 2.0% of NaOCl for 20min., the contamination rate was the lowest. And the survival rate of the culture material was good in carbenicillin 500mg/L treatment group. Callus was obtained from shoot tip and young leaf segments. NAA 0.1-1.0mg/L and 2,4-D 0.1-0.5mg/L alone treatment were shown to have a good response on callus induction from shoot tip culture. In the case of young leaf culture, NAA and 2,4-D 0.1-0.5mg/L alone treatment were good in callus induction. In culturing shoot tip NAA 0.5mg/L and BA 0.5mg/L, NAA1.0mg/L and BA 0.lmg/L combination treatment was good in shoot regeneration. The regenerated shoots were rooted on MS medium supplemented with NAA and BA combination treatment. Especially, NAA 1.0mg/L and BA 0.1mg/L combination treatment was effective for root regeneration.
        620.
        2003.12 서비스 종료(열람 제한)
        American ginseng (Panax quinquefolium) is herbaceous perennial plants indigenous to North American forests. This is highly valued as medicinal herbs with a long history of collection from wild populations since 1716. Wild American ginseng distributed from Quebec in Canada to northern Florida in USA. A heavy concentration is found in the Appalachian mountains, although wild American ginseng is considered endangered. The price paid for field cultivated ginseng has dropped dramatically in the past 10 years, while the price for wild or woods cultivated ginseng has rised significantly. The price curve for ginseng resembles a roller coaster, reflecting not only supply and demand but many other factors. This information will be useful to understand American ginseng compared to Korean ginseng.
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