• Journal of the Korean GEO-environmental Society
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• v.13 no.3
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• pp.59-70
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• 2012

In this study, to select the best stabilizer for the heavy metals-contaminated soil from a smelter area during phytoremediation, a plant uptake experiment and a soil stabilization were simultaneously applied using Pteris multifida Poir. and five pre-screened stabilizers(zeolite, Mn dioxide, slag, Ca oxide, and magnetite). The extracted heavy metal was measured and compared using a 3 step sequential extraction for the soil samples. The growth rate of the plant was also evaluated. The stabilizers stabilized heavy metals in soil and reduced the extraction rate. Magnetite and calcium oxide showed better results than other stabilizers. The stabilizers enhanced the growth of the plant. All the heavy metals except for arsenic were concentrated in roots while arsenic was concentrated in leaves of the plant. It is concluded that the stabilizers can minimize the heavy metal release from the contaminated soil during phytoremediation and stimulated the growth of plant. These effects of stabilizers could compensate for some weak points of phytoremediation such as reaching of heavy metals by rainwater.

• The Journal of Korean Association of Computer Education
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• v.7 no.5
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• pp.1-8
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• 2004

This study investigated the effect of visual learning preference levels in computer assisted instruction (CAI) using static graphics and animations on students' conceptual understandings, application abilities and learning motivations. Fifty-nine seventh graders were selected from a middle school in seoul, and they were taught about the motion of molecule for 4 class hours. Two-way ANCOVA results revealed that the scores of the conception test of the animations group, regardless of student's visual learning preference levels, were significantly higher than those of the static graphics group. However, there were no differences between the two groups in the scores of application test and learning motivation test.

• Journal of The Korean Association For Science Education
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• v.29 no.2
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• pp.156-167
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• 2009

This study investigated the effects of dynamic visual on students' field independence-dependence on connecting errors and conceptual understanding in learning chemistry concepts with multiple representations. Seventh graders (N=123) at a co-ed middle school were assigned to a static visual (SV) group learning with text and static visual, and a dynamic visual (DV) group learning with text and dynamic visual. The students then learned 'Boyle's Law' and 'Charles's Law' for two class periods. Results revealed that the percentages of the DV group were lower than those of the SV group on connecting errors. However, the percentages of the students' connecting errors were still high regardless of their field independence-dependence. There was a little different tendency in the percentages of connecting errors between the two groups by students' field independence-dependence according to the types of connecting errors. The scores of the DV group were significantly higher than those of the SV group in a test on conceptual understanding. However, there was no significant interaction between the instruction and the students' field independence-dependence. Educational implications of these findings are discussed.

• Journal of The Korean Association For Science Education
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• v.26 no.3
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• pp.367-375
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• 2006

This study investigated the effects of varying visuals in drawing and writing as methods to assist students in connecting and integrating multiple external representations provided in learning the particulate nature of matter. Seventh graders (N=233) at a coed middle school were assigned to control, static drawing (SO), dynamic drawing (DD), static writing (SW), and dynamic writing (DW) groups. The students were taught about "Boyle's Law" and "Charles's Law" for two class periods. Two-way ANCOVA results revealed that the scores of a conception test for the two drawing (SD, DD) groups and the two writing (SW, DW) groups were significantly higher than those for the control group. Within the writing groups, students of lower spatial visualization ability in the DW group scored significantly higher than those in the SW group. However, no significant differences were found in the scores of the conception test for the two drawing (SD, DD) groups regardless of students' visualization ability. Researchers also found that most students in both DD and DW groups had respectively positive perceptions of dynamic visuals in drawing or writing.

• Journal of the Korean Vacuum Society
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• v.4 no.4
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• pp.386-393
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• 1995

이온주입된 실리콘 시료들의 열처리 조건에 따른 재결정화를 분광 타원해석법(Spectroscopic Ellipsometry, SE)을 사용하여 연구하였다. 열처리 후에도 잔류하는 결함들의 양과 분포를 구하기 위한 시료의 층구조 분석에 있어서 손상층의 유효굴절율은 Bruggeman 유효매질이론을 이용하여 구하였으며 기준 비정질실리콘 데이터로서는 완화된 비정질실리콘의 광학상수와 이온주입에 의해서 만들어진 비정질 실리콘의 광학상수를 함께 사용하였다. 조사된 대부분의 열처리 조건하에서 고체상 적층성장(solid-phase epitaxial growth)과정에 따라 비정질층이 재결정화되는 것이 관측되었다.

• 월간 기계설비
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• s.241
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• pp.55-62
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• 2010

건설업체가 불법 부당 행위로 법을 위반할 경우 행정처벌이 무겁고 엄격하다. 때문에 건설 실무자들은 반드시 건설업 벌칙규정을 명확하게 숙지하고 있어야 한다. 본지는 이번호부터 일선 현장 및 사업 영위에 필요한 건설업 벌칙규정을 알기 쉽게 편집해 소개한다. 이번 호에 게재되는 하도급거래공정화에 관한 벌칙중 $\blacksquare$부분은 새로 개정된 것으로, 회원사의 건설 실무에 많은 참고 바란다.

• 월간 기계설비
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• s.242
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• pp.56-60
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• 2010

건설업체가 불법 부당 행위로 법을 위반할 경우 행정처벌이 무겁고 엄격하다. 때문에 건설 실무자들은 반드시 건설업 벌칙규정을 명확하게 숙지하고 있어야 한다. 본지는 지난 6월호부터 일선 현장 및 사업 영위에 필요한 건설업 벌칙규정을 소개하고 있다. 이번 호에 게재되는 하도급거래공정화에 관한 벌칙 중 $\blacksquare$ 부분은 새로 개정된 것이다. 회원사의 건설 실무에 많은 참고 바란다.

• 월간 기계설비
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• s.66
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• pp.80-85
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• 1996

• FLOWER RESEARCH JOURNAL
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• v.17 no.1
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• pp.52-61
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• 2009

This study was conducted, to understand floras and circumstances of Korean swamp inland. The floras of 7 swamp inland were 32 families, 49 genus and 69 species. They are accounted for 23% with 16 species of Cyteraceae, one group of annual herbaceous plants, and 6 groups of perennial herbaceous plants (Scirpus tabernaemontani, Phramites communis, Zizania latifolia, Persicaria thunvergiicsiebold, Typha latifolia, Juncus krameri, and Juncus effusus). The plants of Scirpus tabernaemontani, Phramites communis, Zizania latifolia, Persicaria thunvergiicsiebold, Typha latifolia, Juncus krameri, and Potagometon distinctus turnes out a dominant species.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.31 no.6
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• pp.19-23
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• 2002

최근 사회는 첨단산업화 속에서 국민생활의 질적 향상과 인구의 도시 집중화 현상에 따라 많은 사람들이 직장 및 작업현장에서 건강에 영향을 미치고 작업능력의 저하를 유발하는 각종 유해물질이 점차 증가하고 있다. 또한 장기간에 걸쳐 호흡기질환을 일으키는 도시의 대기오염은 매우 심각한 사회적문제로서 관심의 대상임에도 불구하고 이에대한 대책이 미흡한 실정이다. 특히 작업장과 실내생활공간은 실내에서 발생되는 오염물질과 외기에서 유입되는 대기오염물질의 영향으로 실내공기의 질은 급속도로 악화되고 있다. 따라서 실내공기질을 쾌적하게 하기 위해서 환기장치의 설치와 지속적인 유지관리는 대단히 중요하다고 할 수 있다. 환기장치설비에서 공기정화장치는 유해 물질을 처리하기 위한 핵심 장치이며 입자상.가스상 물질에 따라 그 종류와 기능이 서로 다르다. 특히 공기정화장치 설비에 보펀적으로 가장 많이 사용되 는 것이 여과기(filter) 이며 사용목적에 알맞는 에어 필터(air filter)의 선정은 전체환기시스템에 막대한 영향을 미치게 된다. 따라서 본 고에서는 산업환기시스템에 사용되고 있는 대표적인 에어필터의 종류와 각각의 특성 및 환기장치 설계상의 에어필터에 관한 이론과 적용기술 등을 설명하고자 한다.