• Journal of Plant Biotechnology
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• v.44 no.4
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• pp.454-461
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• 2017

This study was conducted to investigate the optimal conditions for spore germination, prothallus propagation, sporophyte formation, and seedling growth in Polystichum braunii (Spenn.) $F{\acute{e}}e$. The rate of spore germination and early prothalium development was high in Knop (41.2%), which had low mineral content. The optimal medium for prothallus propagation and sexual organ formation was 2MS medium (2% sucrose). Among the various mixtures of cultivation soil (bedding soil, peat moss, perlite, and decomposed granite), a mixture of bedding soil and decomposed granite at a ratio of 2:1 (v:v) had a positive effect on sporophyte formation (276.3 ea/$7.5m^2$). The most efficient conditions for promoting the growth of sporophytes were pots filled with only bedding soil.

• The Korean Journal of Mycology
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• v.12 no.2
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• pp.65-73
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• 1984

Strain IV caused highest reduction of germination and caused abnormal elongation of all part of the plant which finally died. Milyang 23 and Nampungbyeo formed mesocotyl. Samnambyeo and Jinjubyeo did not formed mesocotyl on the soil surface in nursery boxes when they were planted on soil infested with each strain of F. moniliforme. Infected seedlings with mesocotyl recovered after transplanting in the the field. The most frequency of Strain IV was isolated from infected rices and this strain was isolated from all part of rice. When rice seedling infected with Strain IV were transplanted in paddy field, most of rice showed Bakanae symptom. Ear emergence of rice was more delayed when seedlings infected with Strain IV were transplanted than that of healthy plant. Number of panicle per hill and grain yield from rice when infected rice seedling by Strain IV were transplanted were more decreased than that of the healthy plant in paddy field.

• Journal of The Korean Association For Science Education
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• v.20 no.3
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• pp.468-478
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• 2000

In this study, the effects of a teaching strategy based on interactive formative assessment on students' science concept understandings and science-related attitudes were investigated. Students' perceptions toward this teaching strategy were also examined. Eight classes chosen from a co-ed middle school in Seoul. Four classes were assigned to the experimental group and the other four classes were assigned to the control group. After the instructions, tests regarding students' conceptions and science-related attitudes were administered. We also interviewed 24 students randomly chosen from the experimental group to investigate their perceptions toward the teaching strategy used. The results showed that the teaching strategy used was more effective for enhancing students' science concept understandings. However, there was no significant difference in science-related attitudes between the two groups. For the experimental group, no significant differences were found in the gain scores of the conceptions tests between the subgroups by previous achievement or cognitive levels. From interviews, it was found that students thought that the teaching strategy used encouraged much interactions and motivated them to think, and that teacher's appropriate feedbacks were helpful to their understanding scientific concepts.

• Current Research on Agriculture and Life Sciences
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• v.29
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• pp.21-27
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• 2011

This study was carried out to produce multiple shoots and bulblets from flower stalk tissue cultures of Muscari armeniacum LEICHTLIN ex BAKER 'Early Giant', which were cultured in the half strength Murashige & Skoog's (MS) medium supplemented with auxin, NAA in combination with kinetin, BA, and TDZ, alone and/or. In flower stalk tissue culture, upper part explant was the most suitable as a source of culture material. Direct shoot formation was much more favorable in half strength MS medium supplemented with $0.1mg{\cdot}L^{-1}$ NAA and $1.0mg{\cdot}L^{-1}$ TDZ. On the other hand, bulblet formation was increased when cultured in half strength MS medium added with $0.01mg{\cdot}L^{-1}$ NAA and $0.1mg{\cdot}L^{-1}$, $0.2mg{\cdot}L^{-1}$ kinetin. Acclimatized plant flowered during the second year of the growing period without any phenotypic variations and formed average 1.5 bulblets per mother bulb.

• Microbiology and Biotechnology Letters
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• v.31 no.3
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• pp.264-270
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• 2003

A quantitative survey of the protozoa microfauna at bioreactor of advanced sewage treatment plant was carried out during a period of 11 months. In this study, 32 genera were identified, including 17 ciliates. The abundance of the important protozoa were compared with the operating parameters and water quality of the effluent of the plant using statistical procedure. Statistical analysis revealed a relationship between the abundance of some genera and removal rate. In particular, correlation analysis on the quality of effluent and protozoa indicated that Lepadella may be used as the bioindicator of TP removal and Trochilia, Entosiphon, Colepus may be used as the bioindicator of TN removal when water temperature was below $20^{\circ}C$.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2007.05a
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• pp.331-335
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• 2007

본 연구에서는 장기간의 현장관측 수온, 염분자료를 분석하여 동중국해 북부해역에서 계절별 수온, 염분의 변동 특성을 조사하였다. 표층의 경우 춘계 수온상승에는 공간적인 차이가 있다. 또한 서부해역($125^{\circ}E$ 이서)에서는 32 psu 이하의 저염 분포가 나타나고 제주 남서해역에서 33psu 이하의 저염수가 춘계부터 제주 주변해역으로 확장한다. 하계 표층염분은 $28.0{\sim}32.4$ psu로 연중 최저값은 보이며, 전해역 표층 염분이 33psu 이하로 저염의 양자강 희석수가 하계에 동중국해 북부해역 표층 전체에 영향을 미치고 있다. 추계의 표층수온과 염분은 동고서저형의 수평분포를 나타낸다. 수온 하강은 서부해역인 대륙 연안수역이 동부의 대마난류수역에 비해 크고, 서부해역에서 33psu 이하의 설상형 저염분포가 이시기에 남동쪽으로 관입되는 형태로 나타나 동계의 남북방향의 염분전선과 이어지게 된다. 연직해황의 경우 동계 수온과 염분은 활발한 대륙작용에 의해 전수층에서 균일한 분포를 나타내며, 대륙연안수역에서는 저온, 저염($12^{\circ}C$, 33psu 이하)의 분포를, 대마난류수역에서는 고온, 고염($16^{\circ}C$, 34.4psu 이상)분포의 지역적인 특성으로 구별된다. 춘계에는 수온약층이 형성되며, 저층에는 동계에 형성되어 대륙연안수와 외양수 사이에 고립된 $13^{\circ}C$ 이하의 냉수괴가 분포한다. 염분은 표층 저염화가 시작된다. 하계에는 양자강 유출수의 영향으로 전해역 표층에서는 30psu 이하로 전해역에서 저염화 양상이 나타나며, 표층에서 30m 층까지 매우 강한 염분약층이 형성된다. 추계 수온 엽문은 균일한 연직수온분포가 나타나며, 동부해역에서는 수심 $75{\sim}100m$사이에서 수온, 염분약층이 형성된다. 동중국해의 수괴는 뚜렷한 계절 변동을 보이며, 대마난류수역인 동부해역에서는 수괴 계절변동의 요인으로 계절 수온변동이 지배적이고, 수온변동은 춘계와 하계 사이에 가장 크다. 중앙부와 대륙연안역인 서부해역에서는 수괴 계절변동에 수온외에 염분 변화가 주요한 요인으로 작용하며, 염분은 하계와 추계 사이에 가장 변동이 크게 나타난다. 즉, 동중국해의 수괴변동에는 변동요인에 따른 공간적인 차이가 있으며, 수괴변화 특성으로 동중국해는 수온변화가 수괴변동에 직접요인이 되는 동부 대마난류수역과 염분변화가 수괴변동의 직접요인인 서부의 대륙연안수역으로 구분된다.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.252-258
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• 2006

The most effective conditions of In vitro culture and ex vitro sporophyte formation from prothallus were studied for mass propagation of Dyropteris varia. The most effective medium of prothallus proliferation was Murashige and Skoog's basal medium supplemented with 10:50mM of $NH_4^+:NO_3^-$ and 2% sucrose. The optimum pH level was 5.8 and prothallus growth was promoted on medium containing $0.6{\sim}0.8%$ agar. Almost of the tested growth regulators (NAA, IAA, 2,4-D, BAP, kinetin and 2ip) were inhibitory in prothallus proliferation as the concentration of growth regulators became higher. The highest number of sporophytes was obtained by transplanting prothallus on compost only than on any other soil compositions. Sporophyte formation was promoted remarkably by soaking prothallus with $100{\mu}M\;GA_3$ for 3 hours.

• Development and Reproduction
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• v.2 no.1
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• pp.81-87
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• 1998

A scanning electron microscopic study on the glochidial encystment and excystment during the development of Anodonta arcaeformis flavotincta on Carassius auratus, a common natural host fish, was carried out. The glochidia were attached to the fins, buccal cavity and gills of the host fish within 30 minutes. In this study, the fins of host fish infected with the glochidia were examined in a time series. The attachment rates of the glochidia on the pectoral fins, caudal fin and pelvic fins of the host fish were 30%, 22%, and 17%, respectively. The glochidia which attached to the fish became encysted within 27 hrs. The process of encystment progressed slowly. Ti took 24 to 27 hours in the formation of the primary cyst, and after 5 to 6 days, the larvae was covered completely with the epithelial cels of the host tissues. The process of detachment of juvenile clam was observed on the 8th day after host infection. Most of the juvenile clams have sloughed from the cyst of the host within 15 days. No significant size difference was observed in the glochidia and the juvenile which were found before attachment and after detachment from the cyst of the host fish.

• Explosives and Blasting
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• v.14 no.4
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• pp.13-19
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• 1996

Lately, the improtance of smooth blasting is increasing on every construction fields, suchas underground caves, tunnels, and roadconstruction, etc. The main purpose of smooth blasting is to prevent unnecessary cracks from the base rockwhich preserved permanently and is to gain the smooth fracture plane. So, in smooth blashing, explosives with low detonating velocity are generally used. But it is difficult to discuss general theory on the smooth blashing because the mechanical properties of pertienent rocks are difficult regionally. Accordingly basic reserches on the smooth blasting are demended. In this paper, the mechanisms of the smooth blasting on the rocks containing discontinuities were discussd. Firstly, the writer predicted the formation of fracture plane and unevenness using mathematical methodology, the next the model blast tests were conducted in order to simulate the crack propagation modes from the blast holes. Through the research, the following conclusions were obtained l)The blast test results were in reasonally good agreement with the theoretical prediction. 2)The degree of discontinuity has an influence on the fracture morphology.

• 한국지구과학회:학술대회논문집
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• 2010.04a
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• pp.71-71
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• 2010

대학생들의 야외 지질 실습 전과 후에 퇴적층 형성에 대한 이해도 변화를 파악하기 위해 충남대학교 지질환경과학과 3학년 재학생 27명을 대상으로 3일 동안, 참여 학생들에게 매일 실습 전과 후로 나누어 6번의 설문 조사를 실시하였다. 설문 조사 문항은 모두 주관식이며, 3일에 걸쳐 총 68문항을 제공하였다. 제시된 문항은 퇴적층 형성과 관련된 기본개념 31문항과 조사 지역의 노두관찰 37문항으로 분류 된다. 야외 실습 전과 후의 개인별 점수를 각각 비교한 결과 실습에 참여한 모든 학생들의 점수가 향상되었다. 실습 3일에 대한 전체 학생들의 평균점수는 실습 전에 28.3점, 후에 51.6점으로 실습 전보다 후에 34.2% 향상되었다. 또한 전체 학생들의 기본개념 31문항에 대한 평균점수는 실습 전에 19.8점, 후에 26.9점으로 22.9%, 조사 지역 노두관찰 37문항에 대해서는 실습전에 8.5점, 후에 24.7점으로 43.8%가 각각 향상되었다. 퇴적층은 공간적으로 넓은 장소와 시간적으로 오랜 기간 동안에 걸쳐 형성되어 학생들은 광범위한 공간적, 시간적 개념을 이해하는 것이 필요하며 대학의 지질학 교육 과정에서 야외실습은 필수적인 요소이다. 야외 실습은 학습자가 직접 자연과 같은 실제 세계를 관찰하고 조사하는 활동으로 이루어지는 학습 방법으로 교실 밖에서 일어나는 모든 학습을 총칭한다고 할 수 있다. 본 연구 결과는 야외 실습 후에 학생들의 점수가 향상된 것을 보여주었다. 이런 결과는 야외 실습이 야외에서 학습자가 주체가 되어 적극적인 참여로 학습하는 학생 중심 학습이고, 자연 환경을 학습의 장으로 하여 실물을 활용한 직접적인 조사활동과 같은 경험에 의한 체험 학습이기 때문인 것으로 해석된다. 또한 야외 실습에서 그룹 활동은 학생들이 지질조사를 하면서 발견된 문제나 내용에 대해 공유할 수 있는 토론 학습인 동시에 야외 활동에서 교수는 전문가 혹은 학습 촉매자로서 문제에 대한 해결책을 주거나 학생들에게 질문이나 토론의 기회를 주어 학생들의 지적, 정신적 향상에 영향을 미치기 때문인 것으로 보인다. 그러므로 야외 실습은 계획, 실행, 정리 단계가 매우 중요하다. 우선 장소 선정에 있어 강의실에서 토론된 주제 및 개념과 관련된 장소를 선정해야 하며, 야외에서는 학생과 학생, 학생과 교수 간의 그룹 활동, 토의 및 질문 시간을 충분히 가져야 함은 물론 실습 후에는 세미나를 통해 야외 활동에서 새롭게 발견하거나 조사 및 학습한 내용, 해결하지 못한 문제 등을 토론하고 정리하는 과정을 갖는 것이 필요하다고 판단된다.