대호 간척기 토양의 염농도별 밭작물의 염해 평가

이승헌,류순호,설수일,안열,정영상,이상모 江原大學校 附設 環境硏究所 2001 環境硏究 Vol.18 No.-

This study was carried out to obtain the basic data for selecting the applicable crops in reclaimed land during desalinization period. A pot experiment was conducted with 5 different electrical conductivities of the saturated extracts (ECe 1, 3, 9, 14, and 16 dS·m^(-1)) of soils taken from the Dae-Ho reclaimed tidal lands. Eight crops (Chinese cabbage, radish, tomato, red pepper, buckwheat, soybean, sesame, and green perilla) were grown for 37days. Plant height and number of leaves were surveyed on 2 and 4 weeks after seeding, and on harvest time (5 weeks). After harvest, dry weights of harvested crops were measured and soil chemical properties were analyzed. Emergence rates of crops were comparatively high except sesame. For sesame, there was no emergence at ECe over 3 dS·m^(-1). Growth and dry weight decreased significantly as increasing ECe. The ECe which decreased 50% of dry weight index were 14.2 dS·m^(-1) for radish, 11.4 dS·m^(-1) for Chinese cabbage, 10.2 dS·m^(-1) for tomato for red pepper, 8.9 dS·m^(-1) for buckwheat and green perilla, 8.6 dS·m^(-1) for soybean, and 8.9 dS·m^(-1) for tomato. At higher ECe that start the growth inhibition, increasing 1 dS·m^(-1) in ECe, 7.7, 6.5, 5.9, 5.6, 5.2, and 4.9% of dry weight decreased for buckwheat, green perilla, Chinese cabbage, radish, soybean, and tomato (red pepper), respectively. The critical value of ECe for crop survival except sesame was 15.4~23.1 dS·m^(-1).

4개 간척 지구에 분포하는 식생과 토양 염류농도

이승헌,지광재,안열,노희명 한국환경농학회 2003 한국환경농학회지 Vol.22 No.2

토양 제염이 토양 화학성 변화와 식물 분포에 미치는 영향을 분석하여 간척농경지의 효율적인 관리방안에 대한 기초자료를 확보하고자 본 연구를 실시하였다. 방조제 체절전후 자연식생이 존재하는 9개 지점에서 식생분포 특징을 조사하고 2개 지점에 대해서는 토양과 식생가의 관계를 검토하였다. 9개 조사지점에서 11목, 14과, 46속, 49종, 8변종, 1품종등 총 58종류의 식생분포가 관찰되었고 자연상태를 잘 유지한 대호 식생보전구와 석문 국가공단 예정 부지에서의 출현종수가 다양하게 분포하였으며 해수를 유통시키고 있는 홍보지구나 만경강, 동진강 하구의 식생은 10 정도로 단순하였다. 9개 조사지점에서 가장 빈도가 높게 출현한 종은 벼과, 명아주과, 국화과에 속하는 나문재(Suaeda asparagoides (Miq.) Maakino), 객개미취(Aster tripolium L.), 갈대(Phragmites australis Trin.), 해홍나물(Suaeda maritima Dum.), 칠면초(Suaeda japonica Dum.), 천일사초(Carex scabrifolia Steud.) 토양에서 염류(Saline)토양으로 그리고 최종적으로 일반 토양으로 변화하였다. 명아주과의 식생은 염도(ECe)가 30 dS/m 전후인 토양에서 출현하여 10 dS/m까지 지속되고, 20dS/m전후에서 객개미취, 산조풀, 사데풀 등이 출현하였으며 10 dS/m 이하에서는 일반육상에서 볼 수 있는 식생종들이 출현하였다. 그러나 토양제염과 동시에 식생의 천이가 일어나는 것은 아니며, 외부에서 종자 등의 식물이 유입될 확률이 있어야하므로, 초기간척지의 식생을 조기에 정착하기 위해서는 토양검정을 통해 적정 염도에서 정착할 수 있는 식생의 인공식재 내지 종자 산파를 통해 촉진시키는 것이 효과적일 것으로 판단된다. This research was conducted to present reference data to be used as newly reclaimed tidal land management. We investigated vegetation succession at 4 reclaimed/reclaiming project areas and discussed relationship with soil and vegetation through investigation and analysis soil chemical characteristics at 2 areas. 14 families 58 kinds were investigated. Vegetation were various at Dea-Ho conservation plot and Seok-Mun National Industrial Area which are maintaining naturally. Vegetation were simple at Hong-Bo and Dongjin and ManKyong river areas which effected sea water. Common species that were investigated at 9 sites were Suaeda asparagoides, Aster tripolium, Phragmites australis, Suaeda maritima, Suaeda japonica, Carex scabrifolia. As soil desalinization progressing, soil classified at first saline-sodic soil, the next saline soil and then normal soil. Chenopodiaceae revealed at about 30 dS/m of soil W e and existed to 10 dS/m of soil ECe. At about 20 dS/m of soil ECe, Aster tripolium, Chlamagotis epigeios, and Sonchus brachyotus revealed and then non halophytes and commom plants at inland revealed at low soil ECe of about 10 dS/m However it was not to progress vegetation succession and soil desalinization at the same time, owing to input of seeds or plants etc from out-ecosystern So for promotion of vegetation at newly reclaimed tidal land, we proposed that it was very effective to plant artificially halophytes or suitable species through soil test.

시효처리와 마모체가 치과용 콤포짓트 레진의 마모에 주는 영향

김승헌,임범순,문현정,이용근,김철위 大韓齒科器材學會 2001 대한치과재료학회지 Vol.28 No.4

Over the last decade, the use of posterior resin composites has grown considerably. Wear resistance of restorative materials is important for clinical longevity, esthetics, and resistance to dental plaque. The purpose of this study was to evaluate the effect of artificial saliva and 75% ethanol solution on the wear resistance of composite resins by measuring the amounts of wear, and compare the effect of antagonistic materials on the wear resistance of composite resins. Four universal composite resins (Z100, Aelitefil, Spectrum, and Unifill F) and two condensable composite resins (Surefil and Synergy Compact) were measured. Cylinder type specimens were light-cured for 40 sec on the wear surface, and 20 sec on each side surface. The surface for wear testing was polished by 600 grit SiC paper. Three different antagonistic materials (600 grit SiC paper, amalgam, and procelain) were used as an antagonist for 2-body wear test. After speciments were aged in 37℃, artificial saliva and 75% ethanol solution for specific periods (1 day, 1 month and 2 month), 2-body wear testing was performed by the FRP-2000 friction tester with applying 500 g load (80 kPa) to the specimen. The wear test was performed for 10 min and 30㎖ distilled water was used as lubricant. Amount of wear was measured by microscopic measuring device of Micro Hardness Tester in 0.1㎛ scale. There was significant difference in wear resistance of composite resins (p<0.05). Composite resins with filler content below 59 vol.% showed higher wear resistance that composite resins those with filler content above 62 vol.%. In composite resins from 1 day to 1 months (p<0.05). On the contray, the wear amounts of groups which filler fraction were above 62 vol.% did not show any significant differences with increasing aging period (p>0.05). In 1 day aged groups, the wear amounts of the groups aged in 75% ethanol solution were more than those of the groups aged for 1 month (p=0.045) and Spectrum group aged for 2 month (p=0.006). Amounts of wear were significantly decreased with changing antagonist from 600 grit SiC paper to amalgam or porcelain (p<0.05).

오염기름 제염에 있어 초임계 이산화탄소의 사용 타당성 연구

박승현,박광헌 慶熙大學校 材料科學技術硏究所 1998 材料科學技術硏究論集 Vol.11 No.-

The main object of this study is a possible use of supercritical fluid in decontamination of contaminated mechanical parts and dresses used in nuclear power plants. Supercritical CO_(2) is a good solvent for cleaning these materials, since it has a powerful ability of penetration to unreachable places and high solubility of oils. And the solubility changes dramatically according to the pressure change, so contaminants can be collected without making any secondary waste. In this study, solubility and removal efficiency of pure oil, gear oil, and grease were measured using supercritical CO_(2) dry cleaning method. The solubility of several oils was shown to increase with pressure ranging from 80 to 200 bars. The removal efficiencies of oil in cleaning mothods using water and that using perclorethylene were compared to dry cleaning with supercritical CO_(2). Oils were removed over 99% in supercritical CO_(2) and in percloroethylene ; however, most of oil was remained in the case of water washing at 60℃. In nuclear power plants, main components of radioactive wastes to be removed are Cs and I. Cs and I were completely removed when we used the water washing method, while percloroethylene and supercritical dry cleaning method couldn't remove Cs and I. To eliminate these components, we used modifier, i.e., a mixture of ethanol and pure water. The results show that removal efficiency of Cs and I in supercritical CO_(2) greatly increases with addition of ethanol and pure water. If this technique becomes materialized, there will be no or less secondary waste for decontamination of contaminated parts and dresses, resulting in more environmentally clean nuclear power plants.

건축에서 지역성의 탈은폐 : 하이데거의 “열린 터”(the Open)와 “틈새내기”(Rift-design) 사유를 바탕으로 Based on the Thought of Heidegger's “the Open” & “Rift-design”

이승헌,이동언 대한건축학회 2003 대한건축학회논문집 Vol.19 No.12

In contemporary architecture, the expression of regionality has been continuously interested and experimented. But there were few theoretical approaches on the meaning of regionality and few authentic explorations for the expression of it. Thus this paper draws out a theoretical frame for regionality from Heidegger's two main thoughts , "the Open" and "Rift-design" and suggests ‘disclosure montage’ as a technique of the practical expression of them in architecture. The ‘creative opening’ of regionality is possible through "Rift-design." And "Gestalt", in other words, disclosure montage, can be created in the "rift" by "the conflict between lighting and concealing in the opposition of the world and earth". An architecturally reactivated images of a region are revealed through the technique of ‘disclosure montage’ as a useful expression strategy of "the Open" and "Rift-design." Finally, in order to verify the above mentioned theory, Steven Hall's works are made into a scrutiny.

청양 지역에 분포하는 트라이아스기 후기의 조계리층에서 산출된 규화목 화석

김종헌,백승덕,이원국 공주대학교 과학교육연구소 2003 과학교육연구 Vol.34 No.-

충남 청양 지역에 분포하는 트라이아스기 후기의 조계리층에서 규화목 화석이 발견되었다. 규화목 화석의 산출은 남한에 분포하는 하부중생계 지층에서 최초의 기록이다. 분류학적 연구결과, 구과류에 속하는 Xenoxylon sp.와 Dadoxylon sp.의 2속 2종이 식별되었다. 본 논문에서 구과류 화석의 특징과 비교 및 그 의미에 대해서 고찰하였다. Petrified wood fossils are discovered from the Upper Triassic Jogyeri Formation distributed in the Cheongyang area. The occurrence of petrified fossils is the first record in the Lower Mesozoic strata distributed in South Korea. As a result of anatomical study of wood fossils, two specie belonging to two genera of Xenoxylon sp. and Dadoxylon sp. which belong to conifers, are recognized. This paper deals with the characteristics, comparison and significance of conifer wood fossils.

제주도 연안 갈치, Trichiurus lepturus 채낚기 어구의 생력화 : 3. 집어등의 수중조도

오승훈,서익조,김병엽,이창헌,정용진,서두옥,김동근 제주대학교 해양연구소 2001 해양자원연구소연구보고 Vol.25 No.-

노인정신의학 연구의 발전 방향 : 알쯔하이머병을 중심으로 Research on Alzheimer's Disease

김승현,이헌정 大韓神經精神醫學會 2002 신경정신의학 Vol.41 No.5

알쯔하이머병(AD)은 전반적인 인지기능의 저하를 보이는 진행성 치매이며, 병리학적으로는 amyloid plaque와 neurofibrillary tangle이 특징적이다. 최근 십여 년 동안 AD의 병태생리에 대한 연구에 있어 중요한 진전이 있었으며, 그로 인하여 질병 발생의 근원적 과정을 직접적으로 차단할 수 있는 새로운 치료적 시도들이 점차 가능해지고 있다. AD의 병인은 아직 확실하게 규명되지 않았지만 일반적으로 질병의 최종 공통경로로서 '아밀로이드 가설'이 가장 유력한 원인 가설로 인정받고 있다. AD를 치료하기 위한 새로운 전략들은 β-amyloid protein(Aβ)의 생산을 중단시키고, Aβ의 제거를 촉진하거나, Aβ의 응집과 침전을 방해하는 시도들이다. 저자들은 본고에서 AD에 대한 현재까지의 연구성과를 요약하고 최근 새롭게 주목받고 있는 치료적 접근 방법에 대해 간략하게 설명하려고 한다. Alzheimer's disease(AD) is a progressive dementia characterized by global cognitive decline and is defined pathologically by amyloid plaques and neurofibrillary tangles. In the past 10 years, important progress has been made in the understanding of the pathogenic mechanism of AD, and new therapeutic targets have become available that should allow the underlying disease process to be tackled directly. In this respect, the 'amyloid hypothesis' has been become the dominant theory in the cause of AD. New strategies for conquering the AD include attempts to stop the production of β-amyloid protein(Aβ), increasing Aβ clearance, or interfere with Aβ aggregation and precipitation into fibril or plaques. This review summarizes recent advances in research on AD and inspects the perspective of research in potential therapies of AD.

알코올의 수분함량과 몰비 변화에 따른 실리콘알콕사이드(TEOS·TMOS)의 수율

노재성,조헌영,홍성수,조태웅 忠南大學校 産業技術硏究所 1993 산업기술연구논문집 Vol.8 No.1

Silicon alkoxides(TEOS:tetraethylorthosilicate and TMOS:tetramethylorthosilicate) were synthesized from silicon tetrachloride and ethanol or methanol with the variation of the mole ratio (alcohol/SiCl_4) and the water contents in the alcohol. The optimum mole ratios of alcohol/SiCl_4 were measured to be betweem 4 and 5 and the reactions completed within one hour. The yield of TEOS decreased from 70% to 48% as the water contents increased from 0.1% to 1.0% in ethanol.

Benzoate에서 배양된 Acinetobacter baumannii로부터 Catechol 1,2-dixoygenase의 정제와 촉매적 성질

송승열,오계헌 순천향대학교 기초과학연구소 2001 순천향자연과학연구 논문집 Vol.7 No.2

The purpose of this work was to perform the catalytic properties and sequence analysis of catechol 1,2-dioxygenase (C1,2O) purified from Acinetobacter baumannii which was grown on benzoate as a carbon source. C1,20 demonstrated its enzyme activity to other substrates, catechol and 4-methylcatechol. The optimum temperature of C1,20 was 35℃, and the optimal pH was in the range from pH 7.5 to 9. Ag^+, Hg^+, and Cu^+2 showed inhibitory effect on the activity of C1,20. Molecular weight of the enzyme was determined to approximately 36 kDa by SDS-PAGE. N-terminal amino acid sequence of C1,20 was analysed as ^1MNYQQIDALVKQMNVDTAKG^20 and exhibited 95% sequence homology with that of C1,20 from Acinetobacter radioresistens. For internal sequencing analysis, trypsin digestion and peptide mapping were performed. Molecular weights of three digested peptide fragments were analyzed as 966.3 dalton, 1933.8 dalton and 2081.7 dalton by MALDI-TOF, which were matched with internal sequences (^1SQSDFNLRR^9, ^1TIEGPLYVAGAPESVGFAR^19, ^1HGNRPSHVHYFVSAPGYR^18)of Acinetobacter radioresistens.