• 한국환경교육학회지:환경교육
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• 제21권2호
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• pp.89-102
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• 2008

Because of the rapid industrialization and urbanization, urban dwellers are lack of opportunity to contact with nature, and hence alienated from it. In particular, primary school children who are very sensible to nature need more opportunities to learn nature by direct interactions with it. For this purpose, a movement for making and using ecological learning-place in play-ground within primary school. It has been found as a result of research on ecological learning-places in 7 primary schools in Daegu that such places, equipped with several ecological facilities, provide both pupils and local dwellers around schools with a place for ecological learning and for rest. But some of them have been left without care and hence can not be properly used, because of inappropriate site, insufficient facilities, and deficient programme for practical use. In conclusion, the paper reconfirms importance of ecological learning-place within grounds of primary school in terms of its educational, social and ecological effects, and suggests briefly some measures to encourage its construction and practical use.

• Journal of Welding and Joining
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• 제17권2호
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• pp.97-103
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• 1999

The dynamic resistance monitoring in primary circuit is one of the important issues. Because in-process and real time quality assurance of resistance spot weld is needed to increase the product reliability. In this study, new dynamic resistance detecting method is proposed as a practical manner of weld quality assurance using instantaneous current and voltage measured at the primary circuit. and also, various patterns of primary dynamic resistance curve are characterized with the macro photograph and the weldability lobe curve. It is found that the primary dynamic resistance patterns are basically similar to those of the secondary, but there is evident advantage such as no extra devices are needed to obtain the quality information and eventually real time feedback control will be possible.

• Toxicological Research
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• 제9권1호
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• pp.119-123
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• 1993

LBD-007, a newly developed recombinant human interferon ${\alpha}$A, was tested for primary eye and skin irritation in male New Zealand White rabbits. In the primary eye irritation test, 0.1ml of a solution of LBD-007 was instilled into the eye. In rinsing group, the eye was washed with water 30 seconds after instillation. No reaction was observed at the cornea, iris and conjunctivae by LBD-007. In the primary skin irritation test, LBD-007 was applied to the back of rabbits for 24 hours. Primary irritation index was "0" in test and control sites of all animals. Thus LBD-007 was evaluated as a non-irritant on the basis of the criteria of Draize et al.,(1994).

• Bulletin of the Korean Chemical Society
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• 제22권12호
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• pp.1341-1344
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• 2001

Comparison of sulfur dioxide primary standard gases of the Korea Research Institute of Standards and Science (KRISS, Korea) and the National Physical Laboratory (NPL, UK) was performed. 100 ${\times}$10-6 mol/mol and 1,000 ${\times}$10-6 mol /mol primary standard gases (designated NPL S115 and S114, respectively) prepared gravimetrically and validated in NPL were used as transfer standards. Transfer standards were analyzed by NDIR sulfur dioxide analyzer and compared with KRISS PSM 112-03-624 and PSM 112-03-625 prepared gravimetrically. Adsorption corrected relative deviations of the primary standard gases were agreed to within 0.1%, and this agreement is within the expanded uncertainties (k = 2) of the primary standards at the two laboratories.

• 천문학회보
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• 제43권2호
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• pp.40.1-40.1
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• 2018

Among Type I supernovae, which show no evidence for hydrogen lines in spectra, Type Ib/c supernovae lack of strong Si absorption lines and are involved with massive progenitors. While strong helium absorption lines are present in Type Ib supernovae, narrow helium emission lines also can appear in some Type Ib that are often called Type Ibn supernovae (SNe Ibn). We consider helium giant stars as a promising progenitor candidate for SN Ibn and suggest the evolutionary scenario through binary systems using MESA code. In our models the range of primary mass is 11 - 20 solar mass, mass ratio is 0.5 - 0.9, and initial period is 1.5 / 1.7 / 2.0 / 2.5 / 3.0 day. In particular, we find that the evolution of the secondary star can overtake the primary through mass transfer from the secondary to the primary, which is so-called 'reverse case B' mass transfer. In such systems the secondary star may undergo a supernova explosion earlier than the primary star. In this case, the primary star evolves towards a single helium giant to become a SN Ibn progenitor. These cases are more frequent in relatively low initial primary mass.

• International Journal of Computer Science & Network Security
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• 제23권2호
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• pp.152-163
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• 2023

This research aimed at investigating Islamic Studies teachers' attitudes towards utilizing virtual learning environment in distance teaching among primary stage pupils. It also aimed at determining the statistical differences among variables due to sex, educational qualification, number of years of experience, and training sessions. This research adopted the descriptive approach. The sample consisted of male and female primary teachers of Islamic Studies (N=250) in governmental schools in Taif. The questionnaire was used as a main research tool. It included (20) items. Results showed that Islamic Studies teachers' attitudes towards utilizing virtual learning environment in distance teaching among primary stage pupils were ranked to a medium degree. There was a statistically significant difference among primary Islamic Studies teachers' attitudes due to sex variable. It was recommended to adopt more training sessions and seminars for adopting the idea of utilizing virtual learning environments among Islamic Studies teachers at boys' and girls' school in Mecca through emphasizing its significance and benefits in Teaching.

• 한국응용곤충학회지
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• 제33권2호
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• pp.51-55
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• 1994

1987년 5월부터 9월 사이에 대전근교의 콩에 기생하고 있는 콩진딧물에서 진디벌에 기생당한 mu-mmy를 채집하여 진디벌과 중기생벌에 관한 생물학적 연구를 수행하였다. 진딧물의 진디벌에 대한 기생율, 진디벌과 중기생벌의 기주선택, mummy형성수와 형성 비율, 주요 진디벌과 중기생벌 종의 수명 등을 조사한 결과는 아래와 같다. 177개의 채집된 진딧물 mummy 중 진디벌은 27.1%m 중기생벌은 50.3%였다. Aphidius cingulatus, Ephedrus persicae, E. plagiator가 콩진딧물에 기생하고 있는 진디벌의 주요 종으로 나타났다. 그리고 이들 진디벌에 기생하고 있는 중기생벌들 중에 A. vulgaris, A. convexa가 우점으로 나타났다. 이들 중기생벌중 Charios brasicae는 한국 미기록종이었다. E.plagiator가 다른 콩진딧물에 기생하는 진디벌에 비해 중기생벌에 적게 기생되었다. 기생능력은 A. cingulatus 보다 E. plagiator가 더 높은 것으로 나타났다. 진디벌과 중기생벌의 수명은 중기생벌이 3일~29일, 진디벌은 1일~4일로 추정되었다.

• Journal of Welding and Joining
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• 제18권1호
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• pp.59-69
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• 2000

The purpose of the present study was to investigate weld metallurgical phenomena such as primary solidification mode, microstructural evolution and hot cracking susceptibility in nitrogen-bearing austenitic stainless steel GTA welds. Eight experimental heats varying nitrogen content from 0.007 to 0.23 wt.% were used in this study. Autogenous GTA welding was performed on weld coupons and the primary solidification mode and their microstructural characteristics were investigated from the fusion welds. Varestraint test was employed to evaluate the solidification cracking susceptibility of the heats and TCL(Total Crack Length) was used as cracking susceptibility index. The solidification mode shifted from primary ferrite to primary austenite with an increase in nitrogen content. Retained delta ferrite exhibited a variety of morphology as nitrogen content varied. The weld fusion zone exhibited duplex structure(austenite+ferrite) at nitrogen contents less than 0.10 wt.% but fully austenitic structure at nitrogen contents more than 0.20 wt.%. The weld fusion zone in alloys with about 0.15 wt.% nitrogen experienced primary austenite + primary ferrite solidification (mode AF) and contained delta ferrite less than 1% at room temperature. Regarding to solidification cracking susceptibility, the welds with fully austenitic structure exhibited high cracking susceptibility while those with duplex structure low susceptibility. The cracking susceptibility increased slowly with an increase in nitrogen content up to 0.20 wt.% but sharply as nitrogen content exceeded 0.20 wt.%, which was attributed to solidification mode shift fro primary ferrite to primary austenite single phase solidification.

• 약학회지
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• 제39권4호
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• pp.444-449
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• 1995

Primary cultures of rat cortical and chicken embryonic brain cells were employed to establish a reliable screening method for natural products blocldng or enhancing glutamate-induced neurotoxicity. Exposure of primary cultured rat cortical cells or chicken embryonic brain cells to high dose of glutamate resulted in the fragmentation of neutites and consequent neuronal death. The level of cytoplasmic lactate dehydrogenase(LDH), indicator for cell survival in cultures, was significantly reduced at exposure to glutamate. For the practical application of the methods, series of concentrations of plants extracts and positive control were applied prior to the glutamate insult on primary cultures of rat cortical and chicken embryonic, brain cells. Relative LDH level in cells was measured for the estimation of the effect of the test materials on the glutamatergic neurons. The validity of the present screening method for natural products acting on glutamatergic neurons was examined with dextromethorphan, a known glutamatergic antagonist. The treatment of 100 $\mu{M}$ dextromethorphan prevented the reduction of LDH in rat cortical and chicken embryonic brain cells caused by glutamate insult keeping 60% and 90% of LDH level in normal control, respectively. Above results indicate that primary cultures of rat cortical and chicken embryonic brain cells could be proper systems for the screening of potential natural agents acting on glutamatergic, neurons. Between the two types of cultures, primary culture of chicken embryonic brain cells seemed to be a better system for the primary screening, since it is technically easier and economical compared to that of rat cortical cells.

• 환경생물
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• 제20권2호
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• pp.146-151
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• 2002

강진만 해역의 6개 조사정점을 대상으로 1998년 2월부터 1998년 10월까지 계절별로 이화학적 환경요인과 일차생산력을 측정하였다. 일차생산력은 $NaH^{14}CO_3$을 이용한 배양방법을 사용하였고, 조사결과 $2.78mgCm^{-3}hr^{-1}-4.92mgCm^{-3}hr^{-1}$의 범위를 나타났으며, 계절별 일차생산력의 변화는 하계, 동계, 추계, 춘계의 순으로 나타났다. 조사정점별로는 강진만의 상류수역에 해당되는 정점 1과 2에 비해 3, 4 ,5 및 6의 조사결과가 크게 나타났다. Chlorophyll a의 분포는 평균 $5.16-17.90mg\;m^{-3}$를 나타났으며 계절별로는 하계에, 정점별로는 정점 4에서 높게 나타났다. 일차생산력과 chlorophyll a를 비롯한 이화학적 조사결과와의 상관관계를 분석한 결과 chlorophyll a의 분포, 수중광도와는 정상관을, 부유물질과는 역상관을 보였으며 강진만의 일차생산력의 변화는 상류수역인 탐진강으로부터 유입되는 담수에 의해 크게 영향을 받고 있는 것으로 생각된다.