• Journal of the Korean Wood Science and Technology
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• v.42 no.6
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• pp.723-731
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• 2014

Nondestructive evaluation (NDE) technique method using a resonance frequency mode was carried out for ceramics made by different carbonizing temperatures (600, 800, 1000, $1200^{\circ}C$) after impregnating the phenol resin with Miscanthus sinensis var. purpurascen particle boards. Dynamic modulus of elasticity increased with increasing carbonizing temperature. There were a close relationship of dynamic modulus of elasticity and static bending modulus of elasticity to modulus of rupture (MOR). However, the result indicated that correlation coefficient was higher in dynamic modulus of elasticity to MOR than that in static modulus of elasticity to MOR. Therefore, the dynamic modulus of elasticity using resonance frequency by free vibration mode is more useful as a nondestructive evaluation method for predicting the MOR of ceramics made by different carbonizing temperature for Miscanthus sinensis var. purpurascens particle boards.

• New & Renewable Energy
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• v.6 no.4
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• pp.6-14
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• 2010

Pretreatment of cellulosic biomass is necessary before enzymatic saccharification and fermentation. Extrusion is a well established process in food industries and it can be used as a physicochemical treatment method for cellulosic biomass. Aqueous ammonia soaking treatment at mild temperatures ranging from 60 to $80^{\circ}C$ for longer reaction times has been used to preserve most of the cellulose and hemicellulose in the biomass. The objective of this study was to evaluate the effect of extrusion treatment on aqueous ammonia soaking method. Extrusion was performed with miscanthus sample conditioned to 2mm of particle size and 20% of moisture content at $200^{\circ}C$ of barrel temperature and 175rpm of screw speed. And then aqueous ammonia soaking was performed with 15%(w/w) ammonia solution at $60^{\circ}C$ for 1, 2, 4, 8, 12 hours on the extruded and raw miscanthus samples respectively. In the combined extrusion-soaking treatment, most compositions removal occurred within 1~2 hours and on a basis of 1 hour soaking treatment values, cellulose was recovered about 85% and other compositions, including hemicellulose, are removed about 50% from extruded miscanthus sample. The combined extrusion-soaking treated and soaking only treated samples were subjected to enzymatic hydrolysis using cellulase and ${\beta}$-glucosidase. The enzymatic digestibility value of combined extrusion-2 hours soaking treated sample was comparable to 12 hours soaking only treated sample. It means that extrusion treatment can shorten the conventional long reaction time of aqueous ammonia soaking. The findings suggest that the combination of extrusion and soaking is a promising pretreatment method to solve both problems for no lignin removal of extrusion and long reaction time of aqueous ammonia soaking.

• Journal of Wetlands Research
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• v.14 no.2
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• pp.199-210
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• 2012

In this study, a pull-out strength increasement of grasses was tested in field and the relationship between a weight of root and pull-out strength was established. The tested grasses were commmon reed, reed and sedge which were cultivated by mat-type like turf and used for revegetation of bank. The shear stress of soil at a section can be discribed as a function of root area and pull-out strength, therefore the result of this study will be used as a foundational data for reinforcing the shear stress of the revegetated bank. The heavier weight of root increased, the stronger shear stress was for all grasses. But the relationship between the weight and the shear stress were different by a kind of grass. The difference between common reed, sedge and reed is due to difference of growth and propagation. A reed propagates by subterranean stem and a root weight and pull-out strength are linearly increased by root and growth of subterranean stem.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.657-661
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• 2007

본 연구에서는 자연형 소하천정비 시범사업 중에서 2003년 하천정비공사가 완료된 후 식생의 침입과 정착하는 과정을 조사함으로서 교란된 하천을 자연형 하천으로 복원하는데 생태학적으로 어떤 공법이 최적의 공법인가를 알아보고자 각 호안공법 별로 식생의 변화특성을 분석한 것으로 결론은 다음과 같다. 이동 소하천에 적용된 다양한 공법(자연석 쌓기, 식생축조블록, 그린리버(환경)블록, 스톤넷, 친환경 돌망태, 식생매트, 환경블록 H형, 반딧불 블록, 지오그린셀, 자연석 3단쌓기 호안)으로 정비된 자연형 하천 복원 후의 식생조성과 목본식물의 침입 및 정착 과정을 조사하였다. 9가지의 공법 중에서 식생 조성과 목본식물의 침입과 정착에 양호하다고 판단된 공법은 자연석 2단 및 3단 쌓기가 가장 좋다고 판단되었고, 그 다음은 지오그린셀 공법, 식생 매트 공법 그리고 그린리버 공법의 순이었다. 친환경 돌망태 공법, 환경블록 공법, 환경 H블록 공법, 식생 축조 블록 공법 및 반딧불 블록 공법은 다른 공법에 비하여 적절하지 못한 공법이었다. 각 공법 간 식생 조성의 유사도 비교에 의하면 시간이 지남에 따라 하천 복원 후 하천 변의 식생이 한 방향으로 서서히 수렴되어 가고 있었다. 하천 공법에 관계없이 봄에 침입하는 식물을 보면 둑의 사면에는 갈퀴나물, 큰김의털, 쑥, 환삼덩굴, 점나도나물 이었고, 수로에는 고마리, 소리쟁이, 미나리, 개구리자리였다. 여름에는 둑 사면에 망초, 억새, 환삼덩굴, 토끼풀이, 수로에는 고마리, 미나리, 미국가막사리, 닭의장풀, 그리고 가을에 많이 침입한 식물은 사면에 파종된 외래식물인 큰김의털, 식재한 억새, 강아지풀 및 환삼덩굴이었음을 알 수 있었다. 처음 침입한 목본은 갯버들, 아카시나무, 내버들 및 버드나무 등 4종이었으나, 1년 후에는 싸리, 산딸기, 쥐똥나무 및 뽕나무가 새로 침입하였다. 이렇게 침입한 목본식물들은 복원된 하천에 다른 물리적인 교란이 심하게 가해지지 않는다면 당분간 계속 생장할 것으로 사료된다.

• The Korean Journal of Ecology
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• v.26 no.4
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• pp.209-214
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• 2003

In order to clarify the successional trend and its characteristics of plant community in abandoned field in Cheju Island, we investigated the seral changes of vegetation height, coverage, growth form, species richness, diversity and dominance index along with the time lapse, and then compared with those of mainland researches. And in order to seek the overall trend of vegetation changes, we used cluster, TWINSPAN and PCA ordination techniques. The succession was characterized by the lower species number, lower vegetation height, longer period of herb dominant and later invasion of tree species. These results may come from that ecological traits of Cheju Island itself, and ecosystem fragmented influences that block a seed (propagule) transport. Sere of the dominant species was shown as follows: Mazus japonicus(0.5∼1 years)→Conyza sumatrensis (2 years)→Artemisia princeps var. orientalis(4 years)→Artemisia princeps var. orientalis, indigofera pseudotinctoria(5 years)→Rosa multiflora, Miscanthus sinensis, etc.(8 years)→Miscanthus sinensis(12 years)→Boehmeria nivea, Pueraria thunbergiana etc.(15 years)→Mallotus japonicus(20 years)→Litsea japonica, Machilus thunbergii (20 years<). Abandoned fields were classified into three groups according to time lapse; earlier stage(0∼1 years), middle stage(2∼8 years) and later stage(8∼20 years).

• Korean Journal of Environmental Agriculture
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• v.32 no.1
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• pp.9-16
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• 2013

BACKGROUND: Eutrophication occurs occasionally in reservoirs around lake in summer and early autumn. Lakeside macrophyte which is one of internal pollutants effects on water quality when it is submerged during rainy season. To improve water quality of water supply source in Boknae reservoir around Juam lake, characteristics of nutrient(N, P) uptake and release by submerged plants were investigated. METHODS AND RESULTS: In order to establish the management plan of submerged plants in Boknae reservoir around Juam lake, water level, rainfall, flooding and non-flooding areas, biomass of dominant plants, contents of nitrogen and phosphorus were investigated during 7 months(August, 2010 through February, 2011). Dominant plants were Miscanthus sacchariflorus(MISSA) and Carex dimorpholepis(CRXDM) in Boknae reservoir. Total plant area of Boknae reservoir in August, 2010 was 987,872 $m^2$. In Boknae reservoir, flooding occurred from August until February caused by rainfall during rainy season. The total amounts of nitrogen and phosphorus uptakes by MISSA were 247 and 22 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus uptakes were 11,340 and 1,231 kg/total reservoir area, respectively. The total amounts of nitrogen and phosphorus residues by MISSA were 34 and 11 kg/total reservoir area, respectively. By CRXDM, the total amounts of nitrogen and phosphorus residues were 491 and 68 kg/total reservoir area, respectively. CONCLUSION(S): Total amounts of nitrogen and phosphorus releases in Boknae reservoir were 12,212 and 1,324 kg/total reservoir area, respectively. The results demonstrate that total nitrogen and total phosphorus in water were strongly influenced by submerged plants. Therefore, management plan for submerged plants during rainy season will be needed to improve water quality of water supply source in Boknae reservoir around Juam lake.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.271-279
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• 1996

This study was conducted to find out the appropriate rates of mixed-seeding of native woody and herb species. It was carried out in greenhouse from 1994 to 1995. The early days germination individuals were $60no./m^2$ in case of woody species for mixed seeding treatment and the treatments were fertilization, soil surface treatment, seeding amount. The investigation factors are the number of individuals of woody and herb species, biomass, height, number of tillers, etc. The mean individuals of Lespedeza bicolor and Amorpha frutzcosa were investigated $1.14no./m^2$, $0.496no./m^2$ in 1995, and Spiraea prunifolia var. simpliciflora and Alnus hirsuta were withering to death. In 1995, the Individuals of Oenothera odorata, Themeda triandra var. japonica, Cymbopogon tortilis var. goeringii, Miscanthus sinensis, Artemisia princeps var. orientalis, Lespedeza cuneata, and Arundinella hirta were investigated $5.06no./m^2$, $1,072no./m^2$, $0no./m^2$, $412.53no./m^2$, $88.6no./m^2$, $8.9no./m^2$, $57.46no./m^2$, respectively, in case of herb species. The height and biomass of Lespedeza bicolor and Amorpha fruticosa showed very fast growth, and those of Themeda triandra var. japonica, Miscanthus sinensis had a similar tendency. For the changes in woody species, according to the seeding amount, there was no significant relationship between species, but It was highly significant in 1995. In case of the herb species, the relationship between the number of individuals and seeding amount was significant for both 1994 and 1995. The most number of tiller was Miscanthus sinensis(21), and showed Themeda triandra var. japonica, Arundinella hirta in descending order. For the mixed seeding of wood and herb species, the number of individuals, height, biomass, tiller of herb species diminished as the seeding amount of herb species increased. It can be concluded that using Lespedeza bicolor and Amorpha fruticosa for woody species and like Arundinella hirta in herb species will be efficient for revegetation measures. It seems, therefore, that the plants of revegetation methods will be used to Lespedeza bicolor, Amorpha fruticosa and Arundinella hirta, and further study is needed on the seeding amount.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.1
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• pp.9-15
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• 2007

The study was conducted to find out the harvesting time, storage duration, cold treatment and sterilization on seed germination of Miscanthus sinensis. The optimum harvesting time of the Miscanthus seed in native to Jeju island was December. And the seed germination passible 3 years after harvesting. When the seeds had cold treatment, seed germination nate was 74% rather than 63% of non-treatment. For seed sterilization treatment, soaking in solution of Benomyl 7% during from 3 hours to 12 hours germinated 9% over. But the non-treatment on 24 hours treatment reduced the seed germination of Miscanthus sinensis.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.54-61
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• 2000

Covering rate, visual rating and sod development were evaluated under three natural fiber materials with Phragmites spp. when over a plastic sheet. The results were as follows. (1) The last covering rate was high on jute net, coir mat and on Miscanthus sacchariflorus, respectively while the early covering rate was high on coir mat and on Miscanthus sinensis+perennial ryegrass. (2) The early growth was good on perennial ryegrass but the covering rate gradually turned poor because of summer drought. (3) Sod was highly developed on Phragmites japonica, Miscanthus sacchariflorus and Miscanthus sinensis compared with other species and mixtures. (4) The covering rate and visual rating were high on natural fiber materials such as coir mat and jute net when compared with on natural fiber materials such as none treatment plots. (5) The natural fibers materials on Phragmites spp. and Miscanthus spp. were effect on sod establishment. Sod coir mat was highly established. (6) The carpet-type sod was best developed on the coir mat.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2004.05a
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• pp.255-257
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• 2004

오염 토양 개선사업이 완료된 밀양시 구운동 광산의 이.화학적 성분을 기초로 하여 비경작지의 일부 야생식물 중 축적된 중금속 함량을 분석한 결과, 토양의 각 지점별 평균 함량은 유기물 13.18g/kg, 유효인산 40.65mg/kg, 석회 5.06, 칼슘 6.85, 고토 1.94cmol/kg으로서 우리나라 밭 토양의 평균보다 낮았고 중금속 함량은 아연(Zn)이 평균 383.1mg/kg, 구리(Cu) 135.2mg/kg, 납(Pb) 105.4mg/kg로 조사되었다. 조사 지점 중 광미의 퇴적으로 인한 오염이 있는 광산 위 st. 3에서 아연(945mg/kg)과 구리(535mg/kg)의 함량이 가장 높았고 다음이 광미가 많이 잔재하고 있는 광구 앞인 st. 4였으며 이곳은 납(289.5mg/kg)의 함량이 가장 높은 지점이었다. 식물체 내의 중금속 함량은 차즈기>쑥>억새>싸리 순이었고 특히 차즈기의 경우는 다량의 중금속이 축적되어 있어 중금속 오염 지역에 대한 내성이 있는 지표종으로 추측되어 이에 대한 중금속 축적 능력 확인 실험이 필요할 것으로 판단된다.