• Journal of Electrochemical Science and Technology
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• v.9 no.2
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• pp.157-162
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• 2018

In the study, herbaceous biomass waste including giant miscanthus, corn stalk, and wheat stalk were used to prepare commercially valuable activated carbons by KOH activation. The waste biomass predominantly consists of cellulose/hemicellulose and lignin, in which decomposition after carbonization and activation contributed to commercially valuable specific surface areas (>$2000m^2/g$) and specific capacitances (>120 F/g) that exceeded those of commercial activated carbon. The significant electrochemical performance of the herbaceous biomass-derived activated carbons indicated the feasibility of utilizing waste biomass to fabricate energy storage materials. Furthermore, with respect to both economic and environmental perspectives, it is advantageous to obtain activated carbon from herbaceous biomass waste given the ease of handling biomass and the low production cost of activated carbon.

• The Korean Journal of Ecology
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• v.20 no.5
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• pp.329-337
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• 1997

Study of population density and biomass of soil microarthropods in soil, herbaceous leaf litter and wood leaf litter was conducted at 4 sites with different flora in Mt. Jumbong, a nature reserve area, in Korea from Aug. 1994 to May 1996. Total 47, 849 individuals of soil microarthropods in soil were collected and identified into 6 different classes, and 16 orders. The composition, densities, and dominant group of soil microarthropods were different among 4 sampling sites. Collembola was the most abundant group with 50.7% at South-facing slope and 50.6% at the North-facing slope. But Acari was the most abundant group with 49.8% at Altitude 900m site and 47.7% at Altitude 1100m site. Two group ranged 87-95% of total individuals. A/C ratio was less than 1.0 at 4 sampling sites during the all sampling seasons. As a result of biomass evaluation, rato of Acari was decreased but ratio of Diplopoda, coleoptera, Araneae, Diptera and Chilopoda was increased. About 70% of total orders and densities were found in less than 5cm soil depth. The composition, densities, and dominant group of soil microarthropods were different among soil, herbaceous litter and wood litter. Collembola was the most abundant group in herbaceous and wood litter. A/C ratio was less than 1.0 in litter during the sampling seasons. As a result of biomass evaluation in litter, ration of Araneae and Collembola was very high, but ratio of Acari was low.

• Korean Chemical Engineering Research
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• v.56 no.4
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• pp.441-446
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• 2018

Herbaceous biomass is easier at chemical conversion than woody biomass. However, pretreatment must be needed because it has substantially lignin. Organsolv is good at fractionation of enzymatic hydrolysis inhibitors such as lignin and it is reusable by distillation when it has low molecular weight. Flow-through process can prevent recondensation of fractionated components and easily separate liquid from the biomass. In this study, the pretreatment was performed for decreasing additional process by using ethanol without catalyst because this process has a lot of operation expense at bio-alcohol production process. Flow-through pretreatment was performed at $150{\sim}190^{\circ}C$ with 30~99.5 wt% ethanol during 20~60 minutes. Also the phsyco-chemical pretreatment was performed for decreasing reaction time and temperature.

• Journal of Korean Society of Forest Science
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• v.96 no.2
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• pp.151-159
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• 2007

This study was conducted to investigate the effects of thinning on changes in stand characteristics and understory vegetation in a silvopasture practiced Japanese larch plantation in the Research Forest of Kangwon National University, Korea. Three different thinning intensities (64%, 35%, and control) were applied. Before and after thinning, the understory plant species increased its number from 48 (7 tree species, 7 shrubs species, 28 herbaceous species, and 6 woody climbers) to 100 (11 tree species, 15 shrub species, 67 herbaceous species, and 7 woody climbers). Thinning made plants invade easily on the forest floor, and plot A (325 stems/ha) had much higher number of undersory species than those Of plot B (575 stems/ha) and control plot (1,150 stems/ha). In three years after thinning, understory aboveground biomass (kg/ha) of herbs were 523 for control, 1,230 for plot B, and 1,288 for plot A. The canopy coverage had remarkable influence on the understory biomass production, resulting in relatively small amount of herbage production on control plot. The differences were statistically significant between thinned plots and unthinned plot, but there were no significant differences among the thinned plots (p<0.05).

• Journal of the Korean Society of Environmental Restoration Technology
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• v.11 no.4
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• pp.46-56
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• 2008

This study examined the natural restoration of vegetation through monitoring of the development of a vegetation community from 2006 through 2007 after a forest fire. Approximately 5,000 $m^2$ in a forest near Topyeon-ri, Kangnae-myeon, Chungcheongbuk-do with Japanese red pine (Pinus densiflora) forest and its floor vegetation had been completely burned by a fire in April 2005. This area and another nearby Japanese red pine forest were selected as the experiment site and the control site, respectively. Vegetation survey was conducted at the experiment site and the control site. A seed bank experiment was carried out in the greenhouse to examine underground vegetation. Effective microorganism(EM) was applied to the seed bank experiment to estimate its effects on the direction of ecological succession. According to the results, a total of 36 plant species including shrub and herbaceous species were discovered in the experiment site. Quercus serrata, Lespedeza cyrtobotrya, and Castanea crenata, Rubus crataegifolius, Oplismenus undulatifolius, and Carex lanceolata were among the most abundant species. Biomass in the experiment site reached 2.4 times biomass than those in the control site, indicating the productivities of shrub and herbaceous layers are better in the experiment site. According to the result of the soil seed bank experiment of the experiment site, a total of 182 plants of 14 species were recorded. In addition, a total of 13 plants of 2 species were found from soil seed bank of the experiment site applied by EM. If EM is applied to the burned site, it will control the budding of herbaceous plants, creating the gap between herbaceous plants. This loss of competition is expected to help the restoration of trees in the burned area.

• Transactions of the Korean hydrogen and new energy society
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• v.29 no.3
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• pp.280-291
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• 2018

Torrefaction is one of the methods to increase combustion calorific value and hydrophobicity of biomass. In this study, the effects of torrefaction on devolatilization, char reactivity and biomass structure were analyzed. Empty fruit bunch (EFB) and Kenaf biomass were used as fuels to be torrefied in the N2 environment at 200, 250 and $290^{\circ}C$. Devolatilization and char kinetics were analyzed by using TGA and biomass structure was investigated through petrography image. The reactivity showed different trends depending on the torrefaction temperature and biomass structure. The herbaceous biomass, Kenaf, was shown as high reactivity and thin wall structure. On the contrary, the woody biomass, EFB, had relatively low reactivity and thick wall structure.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.6
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• pp.9-20
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• 2015

The demand of renewable energy is expected to grow in the long run in spite of current stable lower oil prices. Energy consumption for heating in horticulture greenhouse is large and affects the profits of the farms. This study analyzed the availability of biomass in rural area and proposed the strategies for utilizing the biomass for greenhouse heating. Data reveal the annual average fuel consumption in greenhouses is about 78 TOE/ha. Considering biomass resource in rural areas, agricultural residues are not sufficient to meet the biomass demand from greenhouses. Therefore it is recommended to secure further biomass including wild herbaceous biomass and woody biomass from forest. Based on the conditions of biomass gasification equipment investment and fuel prices, maximum allowable price of biomass turned out about 100,000 KRW/t to be competitive to kerosine. Biomass supply chain should be established for facilitating biomass trading between biomass consumers and biomass producers such as farmers who provide crop residues. An online trading system is an example of the system where consumers who utilize biomass make payments to suppliers and get the information about the biomass. Intermediate collection storages are required to store biomass from distributed sources. Operation of biomass heating systems in demonstration greenhouses is necessary to get information to refine and further develop commercial biomass heating systems. Relatively large greenhouses are desirable to have biomass heating systems for economic viability. The location of the greenhouse farms should be selected within the area where enough biomass resources are available for feeding the biomass facility.

• Journal of Soil and Groundwater Environment
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• v.16 no.1
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• pp.51-61
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• 2011

Germination tests were conducted to determine the practical concentration levels at which plants can reproduce naturally during the phytoremediation of soils contaminated with a high concentration of petroleum hydrocarbons and heavy metals. The effects of humic acids on plant growth and soil physicochemical properties were also investigated. The results show that phytoremediation can be applied in soils contaminated by multiple contaminants at the former soil contamination potential level of Korean soil quality standards considering successful natural reproduction. It was observed that germination rates of Helianthus annuus and Festuca arundinacea were high after all treatments, and transplantation was more appropriate for Phragmites communis in phytoremediation. Humic acids had a positive effect on the growth of both aboveground and belowground biomass of herbaceous plants. Growth inhibition by multiple contaminants is more severe in the case of aboveground biomass. Germination and growth tests suggest that Helianthus annuus is a suitable phytoremediation plant for soils contaminated with a high concentration of petroleum hydrocarbons and heavy metals. The addition of humic acids also caused changes in the physicochemical properties of contaminated soils. An increase in the carbon and nitrogen content due to the addition of humic acids and a correlation between cation exchange capacity(CEC) and the organic matter content were observed.

• Journal of The Korean Society of Agricultural Engineers
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• v.61 no.3
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• pp.89-99
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• 2019

The project to utilize kenaf as thermal power plant fuel has a positive effect on the unused energy utilization, greenhouse gas reduction, and farm income. However, it is analyzed that it is difficult to secure economical efficiency because the fuel cost of kenaf is higher than that of power by thermal power plant and Renewable Energy Certification (REC). The project of power generation using kenaf is meet the government's major policies, while government support is essential for securing economical efficiency. As a result of the sensitivity analysis on the ratio of the government subsidies, to secure economical efficiency, the power generation prices using kenaf through the direct financial support of the government indicate that 47% and 76% of kenaf fuel cost are supported by government in case of the Saemangeum reclamation and Gangneung-si, respectively. In the case of the government indirect policy support, if kenaf is included as a renewable energy source of Renewable Energy Portfolio Standard and REC is granted, the economic efficiency of Saemangeum reclamation and Gangneung-si is obtained when REC secured at 1.05 or more and 2.43 or more, respectively. The results of this study are meaningful in that the direct and indirect effects of the government on the development of the herbaceous energy crop, kenaf, were evaluated economically. These results are to suggest the need for demonstration study, but economics analyze and evaluate are necessary based on operational data through the demonstration phase in the future.

• 한국연소학회:학술대회논문집
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• 2014.11a
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• pp.375-378
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• 2014

In this study, we carried out torrefaction experiment using PKS(Palm Kernel Shell), and Bagasse as a raw material of oversee of herbaceous biomass and using waste wood and logging residue as a raw material of domestic of woody biomass. And then, by analyzing the physical & chemical properties, we investigated the characteristics as a fuel. By using the result of thermo gravimetric analysis, the biomass residue was torrefied for 30 minutes at a temperature range of $250-350^{\circ}C$ in anaerobic condition. As a result, torrefied materials of moisture content are lower than raw, but of fixed carbon, calorific value and ash are higher than raw.