• 한국초등과학교육학회지:초등과학교육
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• 제22권2호
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• pp.138-148
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• 2003

This study was to analyze how elementary school science textbooks explain dissolution and to examine the patterns of elementary school teachers' conceptions on dissolution and the teaching practices on dissolution of elementary school teachers. According to the result of the textbook analysis, the textbooks based on the 7th curriculum didn't explain dissolution very differently from those based on the 6th curriculum. The contents dealing with dissolution in the textbooks of 7th curriculum became difficult gradually as the year went up, but the connected organization of the contents made students learn it easily. For example, in order to learn dissolution introduced first in the 3rd year 2nd semester textbook, students would tell soluble substance in water from insoluble substance in water as they put powdered substance in water. In the 5th year 1st semester textbook students were supposed to acquire the knowledge related to dissolution through the designed activities such as comparing solubility produced by different solvents and defining a solvent, a solute, dissolution, and a solution. In addition, teachers' guide for 5th year 1st semester textbook elucidated the principle of dissolution using attraction concept that was scientific. The result of the survey on teachers showed that 90% of elementary school teachers understood the dissolution of salt in water just as millet particles' filling the space between bean particles and they responded that they demonstrated millet particles' filling the space between been particles when they taught the dissolution of salt in water. When it comes to teachers who had the right idea on dissolution as the attraction conception, understanding was one thing and teaching was another, because they often instructed dissolution as the space conception in the real teaching.

• Journal of Forest and Environmental Science
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• 제30권2호
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• pp.243-252
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• 2014

Forest tree species usually takes for long periods to be harvested and cultivated but spearmints are a good model system for woody plant because of reducing and shortening cultivation time. Spearmints are good model plants (Mentha species) for research about terpenoids production and industrial essential oil manufacture. Isopentenyl pyrophosphate isomerase (Iso) and limonene synthase (Limo) are the key enzymes of terpenoid biosynthesis pathway. Transgenic and wild spearmints (Mentha spicata, MS) were cultured in vitro and assessed for the essential oil contents. The content of essential oil of transgenic spearmint also was enhanced slightly depending on the target terpenoid genes. In an attempt to increase productivity of terpenoids further, salt and fungal elicitation strategy was adopted on transgenic Mentha spicata. The salt (800 mM NaCl) as abiotic and two fungi (Botrytis cinerea and Glomerella cingulata) as biotic were used for elicitors. In the absence of salt stress four terpenoids were detected from the spearmint extracts, all of them being monoterpenes. On the other hand, the transgenic (MSIso) extracts contained eleven terpenoids (10 monoterpenes and 1 phenylpropene) while transgenic (MSLimo) extracts contained seven monoterpenes. After 3 days of fungal infection, the resistance indices further increased to 4.38, 3.89 and 2.04 for wild type, MSIso and MSLimo, respectively. The salt and fungal elicitators proved beneficial towards modifying both the terpenoids profile and improvement in the composition of essential oil. These results have important applications for the large-scale production of essential oils and forest biotechnology with respect to spearmint.

• The Korean Journal of Ecology
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• 제24권2호
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• pp.101-109
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• 2001

We created an environmental forest on the basis of ecological design around the incineration plant of Jindo Engineering and Construction Co., Ltd., which is located in Jeongwang-dong, Siheung-si, Kyunggi-do. To get ecological information of this site, physico-chemical properties of soil on salt marsh, which is located close to the syudy site and of forest soil transported from other sites for ecological restoration were analyzed. Texture of salt marsh and transported soils were loam and sandy loam, respectively. pH, organic matter, T-N, available P, and exchangeable K and Na contents of salt marsh and transported forest soils were 6.7 and 5.4, 4.1 and 0.4%, 1.0 and 0.3mg/g, 46.7 and 6.8ppm, 521 and 207ppm, and 3.8 and 0.5mg/g, respectively. Introduced plants were selected among the dominant species of forests and the species composing the potential natural vegetation around the present study site. Those plants were selected again by considering the tolerances to air pollution and to salt, and their availability. Selected trees were Pinus thunbergii, Sophora japonica, Celtis sinensis, Quercus aliena, Q. serrata, Q. dentata, and Q. acutissima. Selected sub-trees were Albizzia julibrissin, Koelreuteria poniculata, and Styrax japonica and shrubs were Rhododendron yedoense var. poukhanense, R. mucronulatum, Callicarpa japonica, Euonymus alatus, E. japonica, and R. schlippenbachii. On the other hand, introduction of herbs was not considered except for Liriope platyphylla, which was ornamentally planted in one site. Planting bed of mound type was adopted to provide the fine drainage system. Mound was designed to furnish litter, A, B, and C layers simuating the profile of forest soil. Slope of mound was mulched by rice straw of 2cm in thickness to prevent for sliding of litter and soil in cases of strong wind or heavy rain. Height of mound was designed to secure more than 1 m by combining A and B layers. Narrow zones, in which mound with stable slope degree cannot be prepared, was designed to equip the standard soil depth with the introduction of stone for supporting. On the other hand, plants with shallow root system were arranged in some zones, in which satisfactory soil depth cannot be ensured. Plants were arranged in the order of tree, sub-tree, and shrub from center to edge on the mound to make a mature forest of a dome shape in the future. Dispersion of plants was designed to be random pattern rather than clumped one. Problems on creation of the environmental forest by such ecological design were found to be management or inspection by non-specialized project operators and inspecting officers, and regulations for construction without ecological background. Alternative plans to solve such problems were suggested.

• 한국식품과학회지
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• 제34권1호
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• pp.1-7
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• 2002

여름무 품종별 무의 절임 특성을 알아보기 위해, 절임 염수(소금 농도: 15%) $(2{\times}2{\times}2\;cm)$로 절단한 3 품종('백봉', '관동', '92343')의 여름 무를 2배의 절임 염수에 넣어 $15^{\circ}C$에서 절이면서 절임 중 깍두기 무의 염도, 중량, 수분함량, 가용성 고형물 함량 및 경도(TPA)를 알아보았다. 3 품종의 깍뚜기 무 모두 절임 시간이 경과 될수록 염도, 가용성 고형물 함량은 증가하였으며, 중량 및 수분함량은 감소하는 경향을 나타내었고, texture analyser에 의한 경도는 감소하는 경향을 나타내었다. 깍두기 무의 소금 농도가 3%에 달할 때까지의 절임 염수의 소금 농도에 따른 최적 절임 시간은 '백봉'은 3시간, '관동' 및 '92343'은 4시간이 적당하였다. 절이는 동안 중량 감소율은 '백봉'이 약간 컸고, '관동' 및 '92343'은 비슷하였다. '관동'과 '92343'은 '백봉'에 비해 수분함량이 적었고, 가용성 고형물 함량이 많았으며 경도가 높았으며 '백봉'은 수분함량이 많고 가용성 고형물 함량이 적었고 경도가 낮았다. 한편, 절임무의 계절별 특성을 알아보고자 '백봉' 및 '백관' 2 품종에 대해 10% 또는 15%의 절임 염수에서 절이는 동안의 깍두기 무중의 염도가 3%에 달하였을때의 절임무 특성을 계절별로 알아본 결과, '백봉'은 염침투 속도, 중량 감소정도, 가용성 고형물 함량 및 경도가, '백광'은 염침투 속도, 중량 감소정도 및 경도가 가을이 봄 및 여름에 비해 높게 나타났으며, 수분 함량은 두 품종 모두 봄 및 여름이 가을에 비해 높게 나타났다.

• 생물환경조절학회지
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• 제10권2호
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• pp.88-94
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• 2001

Ash ball 배지의 이화학적특성과 사용배지의 염류집적 및 제거효과를 펄라이트 및 입상암면과 비교하였다. ash ball의 가비중, 진비중, 공극율은 각각 0.93 g.$cm^{-3}$, 2.29 g.$cm^{-3}$, 40.6%, 59.4%로서 그중 가비중은 펄라이트 및 입상암면에 비해 현저히 높았고 가공율은 낮았다. 배지의 포화수분함량(saturation moisture capacity)은 ash ball이 52%, 펄라이트가 71%, 입상암면이 90%로 나타났고, 배수 1시간 후 수분율은 ahs ball이가 21%, 펄라이트가 27%, 입상암면이 80%로 낮아졌다. Ash ball의 입도별 수분율은 소립(3~5 mm)이 대립 (7~15mm)에 비해 5% 정도 높았다. Ash ball의 배드내 수분율은 수직 및 수평방향의 분포가 균일하여 수분확산성이 좋은 것으로 나타났다. ash ball의 pH는 7.6으로 약염기성을 나타내었다. 배지를 침지한 배양액의 pH는 7.6으로 약염기성을 나타내었다. 배지를 침지한 배양액의 pH는 다소 증가하는 경향을 보였으며 EC는 거의 변호가 없었으며, 배지내 무기이온의 흡착은 ash ball과 입상암면은 인산의 흡착이 비교적 많았다. 토마토 재배에 사용된 ash ball의 염류집적은 펄라이트와 비슷하였고 8회 정도의 침수처리로 배지표면에 흡착된 무기염을 대부분 제거할 수 있었다. 위의 결과로부터, ash ball 배지는 보수력은 다소 낮지만 통기성 및 수분확산성이 우수하여 배지내의 수분조절이 용이한 배지임을 알 수 있었다.

• 방사성폐기물학회지
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• 제16권1호
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• pp.59-64
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• 2018

사용후핵연료을 건식처리하는 파이로프로세싱 중 전해정련 및 제련공정 후 발생되는 우라늄과 초우라늄 및 희토류 등의 염화물을 함유한 LiCl-KCl 공융염에는 특히 희토류 함량이 높기 때문에 유효자원으로 활용이 가능한 형태의 우라늄과 초우라늄의 분리/회수가 쉽지 않다. 이러한 문제점을 해결하기 위해 본 연구에서는 $LiCl-KCl-UCl_3-NdCl_3$ 시스템에서 산화제($K_2CO_3$)를 이용하여 $UCl_3$를 산화물 형태로 전환한 후 전기화학적 방법을 이용하여 $NdCl_3$를 금속형태로 분리하는 실험을 실시하였다. 실험에 앞서, 이론적 평형계산을 수행하여 우라늄 염화물을 산화물로 전환하기 위한 실험조건을 결정하였다. 상기의 실험에서 LiCl-KCl 내 $UCl_3$는 첨가제의 주입량이 이론적 반응당량에 근접하였을 때 거의 대부분이 염내에서 염화물 형태로 존재하지 않는 것으로 나타났다. 이후 액체금속음극을 이용하여 $NdCl_3$를 금속형태로 전착시켰으며, 전착실험 후 투명한 용융상의 LiCl-KCl 공융염과 갈색의 우라늄 산화침전물이 존재함이 확인되었다. 이러한 결과들을 통해 $LiCl-KCl-UCl_3-NdCl_3$ 시스템에서 우라늄 및 희토류를 각각 분리할 수 있는 방안을 수립할 수 있을 것으로 판단된다.

• 한국수산과학회지
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• 제16권2호
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• pp.140-146
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• 1983

젖산, 솔비톨 및 에틸알코올을 첨가하여 식염농도를 낮춘 정어리젓 숙성중의 정미성분을 규명하기 위하여 핵산관련물질, 유리아미노산, betaine, TMAO, TMA, 총 creatinine 정량 및 omission test를 행하였으며, 지방산패 정도를 알기위하여 TBA값을 측정 한 결과는 다음과 같다. 1. 젖산 $0.5\%$, 솔비톨 $6\%$, 에틸알코올 $6\%$를 첨가하여 담금한 저염정어리젓은 숙성 60일경에 맛이 가장 양호하였으며, VBN은 숙성 100일 이후에도 70mg/100g미만이었고, 아미노질소는 숙성 60일경에 가장 높았다. 2. BHA를 $0.02\%$ 첨가한 결과, TBA 값은 숙성50일까지 서서히 증가하다가 그 후는 서서히 감소하였으며 식염농도가 높을수록 TBA값은 낮았다. 3. 원료육의 유리아미노산 조성은 histidine, taurine이 전유리아미노산의 $93.3\%$를 차지하였고 arginine, valine, tyrosine, phenylanine은 흔적에 불과 하였으나, 숙성 60일째의 정어리젓의 유리아미노산 조성은 lysine, leucine, histidine, glutamic acid, arginine, alanine의 6종이 식염농도에 따라 약간의 차이는 있으나 전체의 약 $58\%$를 차지하였고, 다음으로 valine, isoleucine 등의 순이었으며, taurine은 흔적에 불과하였다. 4. 숙성 60일째의 정어리젓 핵산관련물질함량은 엑스분질소화합물의 $0.1\%$였고, betaine은 숙성중 약간 증가하였으며 총 creatinine은 감소하였다. 또한 TMAO는 감소한 반면 TMA는 증가하였다. 5. 정어리젓의 정미성분으로서는 유리아미노산이 주된 구실을 하며 핵산관련물질도 중요한 구설을 한다는 것을 알 수 있었다. 그리고 betaine 총creatinine, TMAO등도 보조체인 구실을 할 것으로 추정된다.

• 농업과학연구
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• 제38권4호
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• pp.631-639
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• 2011

This research was conducted to investigate potential use of New Zealand spinach (Tetragonia tetragonoides) as a new vegetable crop which will be cultivating in salt-affected soils including reclaimed land. Traditionally New Zealand spinach has been studied to explore functional compound or salt removing potential. To cultivate the crop species in the salt-affected soil widely, it is essential to obtain salt and soil texture responses under the controlled environment. Fifty nine New Zealand spinach ecotypes native to Korean peninsula first collected over seashore areas, and primitive habitat soil environment was evaluated by analyzing soil chemical properties from 32 locations. Different textures of sandy, silt loam, and sandy loam soils were prepared from nearby sources of sea shore, upland and paddy soils, respectively. Target salinity levels of 16.0 dS/m, 27.5 dS/m, 39.9 dS/m, and 52.4 dS/m in electrical conductivity (ECw) were achieved by diluting of 25, 50, 75, 100% (v/v) sea water to tap water (control, 0.6 dS/m), respectively. Various measurements responding to soil texture and irrigation salinity included plant height, root length, fresh weight (FW), dry weight (DW), leaf parameters (leaf number, leaf length, leaf width), lateral branching, and inorganic ion content. was found to adapt to diverse habitats ranging various soil chemical properties including soil pH, organic matter, exchangeable bases, EC, and cation exchange capacity (CEC) in Korea. Responding to soil texture, New Zealand spinach grew better in silt loam and sandy loam soil than in sandy soil. Higher yield (FW and DW) seemed to be associated with branch number (r=0.99 and 0.99, respectively), followed by plant height (r=0.94 and 0.97, respectively) and leaf number (r=0.89 and 0.84, respectively). Plant height, FW, and DW of the New Zealand spinach accessions were decreased with increasing irrigation salinity, while root length was not significantly different compared to control. Based on previous report, more narrow spectrum of salinity range (up to 16 dS/m) needs to be further studied in order to obtain more accurate salinity responses of the plant. As expected, leaf Na content was increased significantly with increasing salinity, while K and Ca contents decreased. Growth responses to soil texture and irrigation salinity implied the potential use of New Zealand spinach as a leafy vegetable in salt-affected soil constructed with silt loam or sandy loam soils.

• Journal of Plant Biotechnology
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• 제35권4호
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• pp.329-335
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• 2008

Tocopherols are essential lipophilic antioxidant in human cells, while little is known about its function in plant tissues. To study the impact of composition and content of tocopherols on stress tolerance, tobacco (Nicotiana tabacum) was transformed with a construct containing a cDNA insert encoding $\gamma$-tocopherol methyltransferase ($\gamma$-TMT/VTE4) from perilla under the control of the cauliflower mosaic virus (CaMV) 35S promoter. The transgenic tobacco was confirmed by PCR and RT-PCR. The total content and composition of tocopherols in the transgenic lines were similar with wild type controls. However, chlorophyll-a and carotenoid content in the transgenic lines were increased by up to 45% (P<0.01) and 39% (P<0.02), respectively. Also, the over-expression of $\gamma$-TMT increased the salt stress tolerance in tobacco plants. These results demonstrate that over-expression of $\gamma$-TMT gene in tocopherol bio-synthetic pathway can increase salt stress tolerance and contents of chlorophyll-a and carotenoid in transgenic tobacco plants.

• 생물환경조절학회지
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• 제20권3호
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• pp.216-220
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• 2011

해안지대에 서식하는 염생식물인 퉁퉁마디의 염처리와 인공토양에 따른 생육반응을 조사하여 시설 내 인공재배상에 적합한 토양을 선발하고자 본 연구를 실시하였다. 토양은 가볍고 인공재배상에서 이용이 간편한 난석, 버미큘라이트, 펄라이트 및 혼용처리로 하였으며 염처리는 NaCl 농도를 200mM로 처리하였으며 복합비료를 시비하여 4개월간 재배하였다. 초장, 생체중, 건물중에 있어서 식물 생육은 다공성 난석과 펄라이트를 혼합한 토양에서 생육이 좋았으며 NaCl 처리 시 생육과 엽록소 함량은 토양종류에 관계없이 감소하였다. 프롤린 함량은 보습성이 낮은 난석과 펄라이트의 경우 대조구 값이 염처리에 비해 높은 것으로 나타났다. 항산화활력은 처리별 그 차이가 거의 없었고 퉁퉁 마디의 경우 염처리가 항산화물질의 증가에 영향을 미치지는 않는 것으로 나타났다.