• Title/Summary/Keyword: DCCA

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Vegetation and Soil Properties of Scrophularia takesimensis Population in Ulleung Island (울릉도 섬현삼(Scrophularia takesimensis Nakai) 개체군의 식생과 토양특성)

  • Han, Kyeong-Suk;Kim, Mu-Yeol;Suh, Gang-Uk;Kwon, Hye-Jin;Song, Ho-Kyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.1
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    • pp.24-31
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    • 2010
  • This study was carried out to analyze vegetation and soil characteristic, and ordination of Scrophularia takesimensis population, Ulleung Island. The Scrophularia takesimensis population was classified into Aster spathulifolius for. oharai dominant population, Vitis amurensis dominant population and Scrophularia takesimensis typical population. The Scrophularia takesimensis population was located in elevation of 1m to 6m, in Ulleung Island. In the study sites, soil organic matter, nitrogen, available phosphorous, exchangeable potassium, exchangeable calcium, exchangeable magnesium and exchangeable sodium concentration, and cation exchange capacity, and soil pH were 9.1~19.1%, 0.19~0.52%, 87.1~196.7mg/kg, 2.0~2.8cmol+/kg, 5.4~5.9cmol+/kg, 5.9~8.8cmol+/kg, 4.4~4.8cmol+/kg, 20.3~26.7cmol+/kg, and 6.8~8.0, respectively. The Vitis amurensis dominant population was mainly found in the high percentage of total nitrogen, organic matter, CEC in comparison with Aster spathulifolius for. oharai dominant population.

The Synthesis of Silica Aerogel in the Macroporous Ceramic Structure by Sono-gel Process and Supercritical Drying Process (초음파 겔화 공정과 초임계 건조 공정을 이용한 다공성 세라믹스 구조체 내부에 실리카 에어로겔 합성)

  • Hong, Sun-Wook;Song, In-Hyuck;Park, Young-Jo;Yun, Hui-Suk;Hwang, Ki-Young;Rhee, Young-Woo
    • Journal of the Korean Ceramic Society
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    • v.47 no.6
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    • pp.553-559
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    • 2010
  • The synthesis behavior of nanoporous silica aerogel in the macroporous ceramic structure was observed using TEOS as a source material and glycerol as a DCCA(dry control chemical additive). Silica aerogel in the macroporous ceramic structure were synthesized through a sono-gel process. The wet gel in the macroporous ceramic structure were aged in ethanol for 72 h at $50^{\circ}C$. The aged wet gel was dried under supercritical drying condition. The addition of glycerol has a role of giving the uniform pore size distribution. The reproducibility of aerogel in the macroporous ceramic was improved in the glycerol(0.05 mol%) added to the silica sol and TEOS : $H_2O$=1 : 12.

The Synthesis of Hydrophobic Silica Aerogel in the Macroporous Ceramic Structure by Ambient Drying Process (상압 건조 공정을 이용한 다공성 세라믹스 구조체 내부에 소수성 실리카 에어로겔의 합성)

  • Hong, Sun-Wook;Song, In-Hyuck;Park, Young-Jo;Yun, Hui-Suk;Hahn, Yoo-Dong;Hwang, Ki-Young;Rhee, Young-Woo
    • Journal of Powder Materials
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    • v.18 no.3
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    • pp.269-276
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    • 2011
  • The synthesis behavior of nanoporous silica aerogel in the macroporous ceramic structure was observed using TEOS as a source material and glycerol as a dry control chemical additive (DCCA). Silica aerogel in the macroporous ceramic structure was synthesized via sono-gel process using hexamethyldiazane (HMDS) as a modification agent and n-hexane as a main solvent. The wet gel with a modified surface was dried at $105^{\circ}C$ under ambient pressure. The addition of glycerol appears to give the wet gel a more homogeneous microstructure. However, glycerol also retarded the rate of surface modification and solvent exchange. Silica aerogel completely filled the macroporous ceramic structure without defect in the condition of surface modification (20% HMDS/nhexane at 36hr).

A Study on the Forest Vegetation of Jirisan National Park (지리산국립공원의 산림식생에 관한 연구)

  • Gwon, Jae-Hwan;Sin, Min-Kyung;Kwon, Hye Jin;Song, Ho-Kyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.5
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    • pp.93-118
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    • 2013
  • In this study, the forest vegetation of Jirisan National Park were classified into 20 communities, 3 subcommunities by the Z-M method. In the analysis of environmental factors, the organic matter and total nitrogen had the highest correlation on the subalpine forests. among them Picea jezoensis community showed the highest, Betula ermanii community, Taxus cuspidata community, Pinus koraiensis community, Abies nephrolepis community and Abies koreana community were represented in order. the K, Mg, Ca had correlation on th montane forests; Quercus mongolica community, Quercus serrata community, Stewartia pseudocamellia community, Pinus densiflora community, Quercus variabilis community were in order. the total nitrogen, electrical conductivity and organic matter had the highest correlation of the montane ravine forests; Fraxinus mandshurica community, Abies holophylla community, Betula costata community, Cornus controversa community and Carpinus laxiflora community were in order.

Vegetation Structure and Ecological Properties of Eleutherococcus senticosus Population (가시오갈피(Eleutherococcus senticosus)개체군의 식생구조와 생태특성)

  • Jung, Jiyoung;Gwon, Jaehwan;Song, Hokyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.16 no.5
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    • pp.27-38
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    • 2013
  • This study was conducted to analyze the correlation between vegetation, environmental factors, and soil characteristic of an endangered species, Eleutherococcus senticosus. Eighteen quadrats in population zones of Seoraksan, Odaesan, Chiaksna, Duckhangsan, Sobaeksan, Juwangsan, and, Jirisan were set up and ordination was analyzed. In the study sites, soil pH, available phosphorous, organic matter and nitrogen were ranged from 5.06~5.43, 24.63~57.77mg/kg, 14.01~18.37%, and 0.63~0.75%, respectively. Eleutherococcus senticosus is classified into Morus bombycis dominant population, Cornus controversa dominant population, and Eleutherococcus senticosus typical population. The importance value of Acer pictum subsp. mono, Morus bombycis, Magnolia sieboldii, Cornus controversa, Tilia taquetii, and Ulmus laciniata in Eleutherococcus senticosus population were 23.76%, 23.61%, 18.06%, 17.82, 15.31%, and 13.57%, respectively. The correlation between vegetation and environmental factors of Eleutherococcus senticosus vegetation distribution were shown to be affected by altitude, slope, and direction.

Effect of Solution Properties on Luminance Characteristics of YAG:Ce Phosphors Prepared by Spray Pyrolysis (분무열분해법으로 YAG:Ce 제조시 용액 조건이 발광특성에 미치는 영향)

  • Lee, You-Mi;Kang, Tae-Won;Jung, Kyeong-Youl
    • Journal of Powder Materials
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    • v.19 no.3
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    • pp.220-225
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    • 2012
  • YAG:Ce yellow phosphor particles were synthesized by spray pyrolysis with changing the solution properties and their luminous properties, crystal structure, and morphological changes were studied by using PL measurement, XRD, and SEM analysis. It was clear that the solution properties significantly affected the crystal phase, crystallite size, the PL intensity, and the morphology of YAG:Ce particles. At low calcination temperature, the addition of urea only to the spray solution was helpful to form a pure YAG phase without any impurity phases, as the result, the highest luminescence intensity was achieved at the calcination temperature of $900^{\circ}C$. When the calcination temperatures were larger than $1300^{\circ}C$, however, the YAG particles prepared without any additive showed the highest luminescent intensity. Regardless of the solution conditions, the emission intensity of YAG:Ce particles prepared by spray pyrolysis showed a linear relation with the crystallite size. In terms of the morphology of YAG:Ce particles, the addition of both DCCA and $NH_4OH$ to the spray solution was effective to prepare a spherical and dense structured YAG particles.

Native Plants Selection for Ecological Replantation in Forest Road Slope - In case study on forest road of Gangwon-do - (임도사면의 생태적 녹화를 위한 자생식물 선정 - 강원도지역 임도를 중심으로 -)

  • Lee, Mijeong;Lee, Joonwoo;Jeon, Kwonseok;Kim, Hyojeong;Choi, Yeonho;Jung, Dohyun;Song, Hokyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.6 no.4
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    • pp.24-32
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    • 2003
  • This study was carried out to select proper species for early stage replantation of forest road cut-slope. From one to fourteen year elapsed forest roads in Gangwon-do, sample plots were selected, and their vegetations and environmental factors were investigated. Invaded species with high frequency ordered Lespedeza cyrtobotrya, Lysimachia clethroides, Rubus crataegifolius, Patrinia villosa, Spodiopogon sibiricus, Pueraria thunbergiana, Youngia denticulata, Dactylis glomerata, Rhus chinensis, and Pinus densiflora. North cut-slope have the highest value of invaded species number and plant coverage, and so, north aspect could be best for plant invasion. According to ordination, distribution of species were influenced by elapsed year, cut-slope aspect, and cut-slope. Lespedeza bicolor, Lespedeza cyrtobotrya, Artemisia stolonifera, Miscanthus sinensis, Rubus crataegifolius, Rhus chinensis, Lindera obtusiloba, and Pinus densiflora were considered with proper species for replantation at south slope. Also, Lespedeza bicolor, Lespedeza cyrtobotrya, Arundinella hirta, Artemisia keiskeana, Astilbe chinensis var. davidii, Rubus crataegifolius, Weigela subsessilis, Stephanandra incisa, and Rhododendron mucronulatum were considered with proper species as replantation at north slope.

A Study on Vegetation Structure and Soil condition of Leontice microrhyncha Population (한계령풀(Leontice microrhyncha) 개체군의 식생과 토양특성)

  • Gwon, Jae-Hwan;Kwon, Hye-Jin;Song, Ho-Kyung
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.13 no.3
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    • pp.84-93
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    • 2010
  • This study was carried out to analyze the vegetation properties, soil characteristics and ordination of Leontice microrhyncha population in South Korea. The Leontice microrhyncha population was classified into Quercus mongolica dominant population, Morus bombycis dominant population, Fraxinus mandshurica population and Leontice microrhyncha typical dominant. The Leontice microrhyncha population was located at an elevation of 633m to 1,336m in Korea. In the study sites, soil organic matter, total nitrogen, available phosphate, exchangeable potassium, exchangeable calcium, exchangeable magnesium, cation exchange capacity and soil pH were 8.40~10.58%, 0.42~0.61%, 14.15~25.07mg/kg, 0.44~0.59cmol$^+$/kg, 2.35~6.33cmol$^+$/kg, 0.35~0.98cmol$^+$/kg, 26.04~33.48cmol$^+$/kg and 4.69~5.32 respectively. Morus bombycis dominant population was found in the low elevation and gentle sloped area that has high percentage of phosphoric acid and less percentage of total nitrogen, exchangeable calcium, exchangeable magnesium than other dominant population. Fraxinus mandshurica dominant population and Leontice microrhyncha typical population were found in the comparatively high elevation area that has low percentage of phosphoric acid and high percentage of total nitrogen, exchangeable calcium, exchangeable magnesium. Quercus mongolica dominant population was found in the medium elevation area that has medium percentage of total nitrogen, exchangeable calcium, exchangeable magnesium.

Forest Vegetation Analysis of Gabhasan and Woosanbong in Daejeon, Korea (대전 갑하산과 우산봉의 산림식생 분석)

  • 김효정;이미정;지윤의;강병선;이규석;송호경
    • The Korean Journal of Ecology
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    • v.25 no.5
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    • pp.297-303
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    • 2002
  • This study was carried out to analyze forest vegetation of Gabhasan and Woosanbong in Daejeon, Employing the releve method of TWINSPAN, 62 plots were sampled from June 2001 to September 2001. Field survey carried out to examine importance value, to do diameter of breast height(DBH) measurement, and to analyze the Ordination. The Forest vegetation was classified into four communities: Quercus mongolica community, Pinus densiflora community, Quercus variabilis community, Quercus acutissima community. The importance value of Pinus densiflora, Quercus variabilis, Quercus mongolica, Quercus serrata and Styrax japonica were high. According to DBH analysis, Pinus densiflora and Quercus variabilis dominate currently, however, importance value of Quercus mongolica, Quercus serrata, Prunus sargentii would increase in the future. The result of ordination analysis, showed that Quercus mongolica community was located in high altitude and steep area, Pinus densiflora community was located in comparatively high altitude and medium slope area, Quercus variabilis community was located in low altitude and gentle slope area and Quercus acutissima community was located in the lowest altitude and relatively gentle slope area.

Vegetation and Soil Properties of Wasabia japonica Population (고추냉이(Wasabia japonica (Miq.) Matsum.) 개체군의 식생과 토양특성)

  • Kim, Mu-Yeol;So, Soon-Ku;Han, Kyeong-Suk;Lee, Ji-Hye;Park, Gwan-Soo;Song, Ho-Kyung
    • Korean Journal of Environment and Ecology
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    • v.22 no.5
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    • pp.530-535
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    • 2008
  • This study was carried out to analyze the vegetation and soil characteristic, and ordination of Wasabia japonica population at Ulleung-Do. The Wasabia japonica population is distributed in altitudes of 440m to 570m at Seo-Myon and also in altitudes of 340m near Nari-valley. In the study sites, soil organic matter, nitrogen, available phosphorous, exchangeable potassium, exchangeable calcium, exchangeable magnesium concentration, cation exchange capacity, and soil pH were 15.01%, 0.48%, 44.19ppm, 2.00(me/100g), 7.19(me/100g), 4.44(me/100g), 22.55(me/100g), and 6.17, respectively. The Rumohra standishii dominant population was mainly found in high in soil nitrogen, organic matter, CEC, and exchangeable calcium concentration in comparison with Boehmeria spicata dominant population. The Boehmeria spicata dominant population was mainly found in high in soil pH.