• Journal of Ecology and Environment
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• v.37 no.4
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• pp.177-184
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• 2014

This study was conducted to develop allometric equations and to determine the stem density and biomass expansion factor (BEF) for the estimation of the aboveground and belowground biomass of Cryptomeria japonica in Jeju Island, Korea. A total of 18 trees were harvested from the 40-year-old C. japonica stands in Hannam experimental forest, Jeju Island. The mean biomass of the C. japonica was $50.4Mg\;ha^{-1}$ in stem wood, $23.1Mg\;ha^{-1}$ in root, $9.6Mg\;ha^{-1}$ in branch, $4.6Mg\;ha^{-1}$ in needle and $4.3Mg\;ha^{-1}$ in stem bark. The diameter at breast height (DBH) was selected as independent variable for the development of allometric equations. To evaluate the performance of these equations, coefficient of determination ($R^2$) and root mean square error (RMSE) were used and results of the evaluation showed that $R^2$ ranged from 71% (root biomass equation) to 96% (aboveground biomass equation) and the RMSE ranged from 0.10 (aboveground biomass equation) to 0.33 (root biomass equation). The mean stem density of C. japonica was $0.37g\;cm^{-3}$ and the mean aboveground BEF was $1.28g\;g^{-1}$. Furthermore, the ratio of the root biomass to aboveground biomass was 0.32.

• Journal of Korea Foresty Energy
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• v.17 no.1
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• pp.23-29
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• 1998

This study was carried out to develop the regression model for estimating biomass of natural Pinus densiflora forests by stand density in northeast Chinese area of Mt. Paekdu. Four allometric regression models(W=aD$^b$, W=a(D$^2$H)$^b$. logW=a+b$\cdot$ logD+cD and logW=a+b$\cdot$log(D$^2$H)+c(D$^2$H)) were used to estimate biomass for each of the tree components. The suitable regression model for estimating biomass of stem, bark and whole tree above ground was logW=a+b$\cdot$log(D$^2$H)+c(D$^2$H), and that for biomass of branch, needle and needle area, logW=a+b$\cdot$logD+cD for all of the stand density classes.

• Korean Journal of Environmental Agriculture
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• v.30 no.3
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• pp.234-242
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• 2011

BACKGROUND: Cultivation of winter cover crops is strongly recommended to increase land utilization efficiency, animal feeding material self-production, and to improve soil and environmental quality. METHODS AND RESULTS: Four major winter crops (barley, Chinese milk vetch, hairy vetch, and rye) having different C/N ratio were seeded in silt loam paddy soil in the November 2007 and the aboveground biomass was harvested on the late May 2008 to evaluate its effectiveness as green manure, and root biomass distribution was characterized at the different depth (0-60 cm) to study its effect on physical properties and carbon sequestration in soil. During this experiment, the naturally growing weed in the rice paddy soil in Korea, short awn foxtail (Alopecurus aequalis Sobol), was considered as control treatment. Above-ground biomass of all cover crops selected was significantly higher than that of the control treatment (2.8 Mg/ha). Comparatively higher above-ground biomass productivity of rye and barley (15.8 and 13.5 Mg/ha, respectively) suggested that these cover crops possibly had the highest potential as a green manure and animal feeding material. Root biomass production of different cover crops followed the same trend as that for their above ground biomass. Rye (Secale cereal) might have the highest potential for soil C accumulation (7893 C kg/ha) by root biomass development, and then followed by barley (6985 C kg/ha), hairy vetch (6467 C kg/ha), Chinese milk vetch (6671 C kg/ha), and control (5791 C kg/ha). CONCLUSION(s): Cover crops like rye and barley having high biomass productivity might be the most effective winter cover crops to increase organic carbon distribution in different soil aggregates which might be beneficial to improve soil structure, aeration etc. and C sequestration.

• Biotechnology and Bioprocess Engineering:BBE
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• v.7 no.4
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• pp.221-224
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• 2002

Biomass of non-viable and dried brown marine algae Ecklonia radiata Turn. was used to examine Its cadmium uptake capability. Twelve different pretreatments on the algal biomass were prepared. Among these pretreatments, the algal biomass, which treated with 0.1 M NaOH and kept in water. bath (100$\^{C}$, 18 h) followed by washing with distilled water and squeezing, showed the highest amount of cadmium uptake as 1634 $\pm$ 195 mg/g dry biomass at pH 4.0 and 50$\^{C}$. Adsorption temperatures and pH levels played some Important role In cadmium uptake. However, cadmium uptake decreased dramatically at a lower pH than 4.0. Freundlich adsorption isotherm showed potent cadmium uptake capacity of the non-viable biomass. Pretreatments on the non-viable algal biomass shown in this study nay enhance the Eadmium removal in the industrial wastewater.

• Journal of Korea Foresty Energy
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• v.18 no.2
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• pp.92-99
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• 1999

This study was carried out to understand the primary production of biomass, vertical biomass distribution in the stand and the difference of biomass production for part of the trees by stand density for natural Pinus densiflora forest at Mt. Baekdoo located in northeastern China. The primary production of biomass was estimated by the layers of trees, shrubs, herbs for five density classes. For the biomass estimation of the Pinus densiflora trees in stern, stembark and the above-ground tree, the regression model of logW = a + blog(D$^2$H) + c(D$^2$H) was adapted for all of the density classes where W is dry weight, D$_1$ diameter at breast height, and H, tree height. For the biomass estimation in branch and needle, and the needle area, the regression model of logW=a+blogD+cD was adapted for all of the density classes. With increasing stand density the biomass of trees increased but that of shrubs and herbs decreased. Net primary production of biomass in parts of the tree also increased with increasing stand density. However the percentage of the needle biomass among the total biomass in the above-ground tree decreased with increasing stand density. Consequently, primary production rate of biomass in the above-ground tree increased. The primary production of biomass for each part of the trees in natural Pinus densiflora natural forests showed in descending order : stern, needle, branch, and stembark regardless of stand density.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.6
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• pp.683-690
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• 2017

Wood pellet (WP), empty fruit bunch (EFB) and palm kernel shell (PKS) which are biomass fuels for power generation are selected to study the characteristics of torrefaction process. These biomass fuels are torrefied at $220^{\circ}C$, $250^{\circ}C$, and $280^{\circ}C$. The heating value of biomass fuels is increased depending on the torrefaction temperature. However, due to energy yield decline, it is not always desirable to torrefy biomass at higher temperature. Considering the mass yield and energy yield after torrefaction, the most proper temperature conditions for torrefaction of WP is $250-280^{\circ}C$ and for EFB, PKS are $220-250^{\circ}C$. Additionally, to investigate the phenomenons of chlorine release during torrefaction process, Ion Chromatography (IC) method was used. In the case of EFB and PKS torrefied at $300^{\circ}C$, the chlorine component has been reduced by 97.5% and 95.3% compared to the raw biomass, respectively. In conclusion, torrefied biomass can be used as alternative fuels in replacement of coals for both aspects of heating value and chlorine corrosion problems.

• Journal of Ecology and Environment
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• v.38 no.1
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• pp.75-84
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• 2015

Tropical forests play a critical role in mitigating climate change, and therefore, an accurate and precise estimation of tropical forest carbon (C) is needed. However, there are many uncertainties associated with C stock estimation in a tropical forest, mainly due to its large variations in biomass. Hence, we quantified C stocks in an intact lowland mixed dipterocarp forest (MDF) in Brunei, and investigated variations in biomass and topography. Tree, deadwood, and soil C stocks were estimated by using the allometric equation method, the line intersect method, and the sampling method, respectively. Understory vegetation and litter were also sampled. We then analyzed spatial variations in tree and deadwood biomass in relation to topography. The total C stock was 321.4 Mg C $ha^{-1}$, and living biomass, dead organic matter, and soil C stocks accounted for 67%, 11%, and 23%, respectively, of the total. The results reveal that there was a relatively high C stock, even compared to other tropical forests, and that there was no significant relationship between biomass and topography. Our results provide useful reference data and a greater understanding of biomass variations in lowland MDFs, which could be used for greenhouse gas emission-reduction projects.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.159-165
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• 2016

BACKGROUND: Carbonized biomass is increasingly used as a tool of soil carbon sequestration. The objective of this study was to evaluate soil carbon storage to application of carbonized biomass derived from pear tree pruning.METHODS AND RESULTS: The carbonized biomass was a mobile pyrolyzer with field scale, which a reactor was operated about 400~500℃ for 5 hours. The treatments were consisted of a control without input of carbonized biomass and two levels of carbonized biomass inputs as 6.06 Mg/ha, C-1 and 12.12 Mg/ha, C-2. It was shown that the soil carbon pools were 49.3 Mg/ha for C-1, 57.8 Mg/ha for C-2 and 40.1 Mg/ha for the control after experimental periods. The contents of accumulated soil carbon pool were significantly (P < 0.001) increased with enhancing the carbonized biomass input amount. The slopes (1.496) of the regression equations are suggested that carbon storage from the soil was increased about 0.1496 Mg/ha with every 100 kg/ha of carbonized biomass input amount.CONCLUSION: Our results suggest that application of carbonized biomass would be increased the soil carbon contents due to a highly stable C-matrix of carbonized biomass. More long-term studies are needed to be proved how long does carbon stay in orchard soils.

• KSBB Journal
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• v.9 no.4
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• pp.365-371
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• 1994

The effects of ratios of initial concentration of carbon source to the initial concentration of nitrogen source in the fermentation media on both the yields of PHB fermentation variables and the accumulation of poly-${\beta}$-hydroxybutyric acid(PHB) were investigated. The fermentation media were composed of the combination of varing glucose concentrations, 10, 20, 25, 30, 40, $50g/\ell$ and the NH4Cl concentrations 0.33, 0.4, 0.5, 1.5, 3, $5g/\ell$. The yield of biomass on glucos, Yx/s, decreased very slowly according to the increase of the ratio of C to N. And the yield became constant at 0.35(g biomass/g glucose) with the ratio higher than 70. The yield of residual biomass, Yx/s, also decreased with the ratio of C to N and finally showed a constant value of 0.065(g residual biomass/g glucose) when the ratio was higher than 65. In accordance with the augmentation of the ratio, the yield of PHB, YPHB/S, however, increased and showed the maximum value of 0.35 (g PHB/g glucose) between 40 and 60 of the ratio. The maximum yield of PHB to the change of biomass, YPHB/S, was 0.87(g PHB/g biomass), and the yie1d YPHB/RX, was 4.2(g PHB/g residual biomass). The maximum accumulation percent of PHB to the final biomass was 81% when the ratio was higher than 67.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.216-219
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• 2000

Pyrolysis products of woody biomass were consistedofvarious linear hydrocarbon, aromatics or condensed cyclic compounds. In order to obtain biomass pyrolysis products, more equipments and time were needed. But solvolysis of woody biomass with acetone easily obtained decomposition products and enhanced conversion rate(18.72%, max.) from woody biomass than pyrolysis of woody biomass. Beacause solvolysis with acetone improved conversion rate (26.64%, max.) of lignin. the whole conversion rate was improved. But above $300^{\circ}C$, lignin showed lower conversion rate, so the whole conversion rate decreased. Solvolysis products of woody biomass with acetone were same as pyrolysis products. Above $400^{\circ}C$, methoxy phenols were completely disappeared.