• Journal of Forest and Environmental Science
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• v.29 no.1
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• pp.81-89
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• 2013

Nowadays, excessive using of fossil fuel contributes to global warming. Also, this phenomenon increases steadily. Therefore forest biomass from logging residues has received attention. The goal of this study was to determine the sustainability and economic feasibility of forest-biomass energy source. Accordingly, forest biomass resource was calculated, and harvesting and transporting machines which can be used in investing area were chosen, when using forest biomass as energy source. And then through these data, the harvesting cost was decided. The forest biomass resource calculated, thinned trees and logging residues, was 37,330.23 $m^3$ and 14,073.60 ton, respectively. When harvesting timber in each sub-compartment, the average thinned trees yield was 120.73 $m^3$, and tree logging residues was 402.80 ton. The use of tower yarder as harvesting and transporting equipments in study area was 85.4% and 66.7%, respectively, in up hill and down hill yarding. The average harvesting cost of biomass in the possibility area of timber yarding operation was expensive as 81,757 won/$m^3$, 85,434 won/m3 and 50,003 won/ton, respectively, in thinned trees and logging residue. If using data from this research analysis, tree could be felled by choosing sub-compartment.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.606-609
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• 2013

To investigate the effect of partial tillage seeding of hairy vetch on green manure biomass and rice yield, on-farm experiment was conducted at eco-friendly hairy vetch cultivation area located in Yesan-gun, Chungcheongnam-do. Seeding methods of hairy vetch consisted of partial tillage seeding (PTS) and broadcasting before rice harvesting (BBRH). Hairy vetch was incorporated into soil on May 18 and rice seedling was transplanted on May 26. The growths of hairy vetch before overwintering were investigated on November 11. Plant height of BBRH plot was longer than that of PTS plot, but somewhat larger number of seedling stand was found in PTS. Biomass and N production of hairy vetch were investigated on May 18. Results of the investigation showed no difference between two seeding methods. Although the seeding time was 21 days late in PTS, the biomass of hairy vetch and rice yield were equivalent to those of BBRH seeding, so we conclude that PTS could improve overwintering survival of hairy vetch in rice cropping system.

• Journal of the Korean Wood Science and Technology
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• v.39 no.2
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• pp.187-195
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• 2011

In this study, dilute acid pretreatment of $Liriodendron$ $tulipifera$ was performed for enzymatic hydrolysis. As the pretreatment temperature was increased, enzymatic hydrolysis and enzyme adsorption yield also increased. The highest enzymatic hydrolysis yield was 57% (g/g) and enzyme adsorption was 44% (g/g). Enzymatic hydrolysis yield was determined with weight loss of pretreated biomass by enzyme, and enzyme adsorption was a percentage of enzyme weight attaching on pretreated biomass compared with input enzyme weight. When $L.$ $tulipifera$ was pretreated with 1% sulfuric acid at $160^{\circ}C$ for 5 min., hemicellulose was significantly removed in pretreatment, but the lignin contents were constant. Other changes in surface morphology were detected on biomass pretreated at $160^{\circ}C$ by a field emission scanning electron microscope (FESEM). A large number of spherical shapes known as lignin droplets were observed over the entire biomass surface after pretreatment. Hemicellulose removal and morphological changes improved enzyme accessibility to cellulose by increasing cellulose exposure to enzyme. It is thus evidence that enzyme adsorption is a significant factor to understand pretreatment effectiveness.

• The Korean Journal of Food & Health Convergence
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• v.6 no.1
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• pp.9-15
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• 2020

Salinity with sodic condition disturbs germination, retards emergence, and slow down seedling development of Lemon Grass (Cymbopogon citratus).Lemongrass is a perennial grass plant widely distributed worldwide and most especially in tropical and subtropical countries. This research experiment was designed to evaluate the influences of (4 dSm^-1+ 13.5 (mmol L^-1)^-1/2, 5 dSm^-1+ 25 (mmol L^-1)^1/2, 5 dSm^-1+ 30 (mmol L^-1)^1/2, 10 dSm^-1+ 25 (mmol L^-1)^1/2 and 10 dSm^-1+ 30 (mmol L^-1)^1/2) on biomass produce of lemon grass against salt tolerance. The uppermost biomass yield (45.53 gpot^-1) was produced by 4 dSm^-1+ 13.5 (mmol L^-1)^1/2 treatment. The increase in the intensity of salts reduced the growth of lemon grass. Lower biomass yield (79.33 gpot^-1) was gained at 10 dSm^-1+ 30 (mmol L^-1)^1/2. 5 dSm^-1+ 25 (mmol L^-1)^1/2 treatment performed enhanced outcome i.e. the least reduction % over control (5.87). Salinity- sodicity showed serious effect on the growth reduction from 5.87% to33.60%. This reduction gap was affected by the negative effect of salinity and sodicity on Linseed growth. Salinity- sodicity showed severe impact on the growth reduction from 5.87% to33.60%. Based on the findings, lemon Grass (Cymbopogon citratus).was capable to grow up the maximum at 4 dSm^-1+ 13.5 (mmol L^-1)^1/2 treatment.

• Journal of Ecology and Environment
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• v.44 no.1
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• pp.8-25
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• 2020

Background: Species of the genera Eucalyptus, Cupressus, and Pinus are the most widely planted tree species in the country in general and in Chilimo dry Afromontane forest in particular. Eucalyptus covers 90% of the total planted forest area in the country. However, only limited information exists in the country regarding aboveground biomass (AGB), belowground biomass (BGB), growth, and yield. This study was conducted to assess the variables on 25 and 30 years of age for three planted species: Cupressus lusitanica, Eucalyptus saligna, and Pinus patula in Chilimo plantation forest, in the Central Highlands of Ethiopia. A two-times inventory was conducted in 2012 and 2017. A total of nine square sampled plots of 400 ㎡ each, three plots under Cupressus lusitanica, 3 Eucalyptus saligna, and 3 Pinus patula were used for data collection. Data on height, diameter, soil, and tree stumps were collected. Percent C, % N, and bulk density was performed following chemical procedure. Results: The aboveground biomass ranged from 125.76 to 228.67 t C ha^-1 and the basal area and number of stems from 3.76 to 25.50 ㎡ ha^-1 and 483 to 1175 N ha^-1, respectively. The mean annual basal area and volume increment were between 0.97 and 1.20 ㎡ ha^-1 year^-1 and 10.79 and 16.22 ㎥ ha^-1 year^-1. Both carbon and nitrogen stock of the planted forest was non-significant among the tree species. Conclusion: The aboveground biomass, growth, and yield significantly varied among the species. Cupressus lusitanica had the highest aboveground biomass, volume, and basal area, while Eucalyptus saligna had the lowest value. To a depth of 1 m, total carbon stored ranged from 130.13 to 234.26 t C ha^-1. The total annual carbon sequestration potential was 12,575.18 t CO₂ eq. Eucalyptus has the highest carbon stock density and growth rate than other species.

• Korean Journal of Environmental Agriculture
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• v.19 no.5
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• pp.375-381
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• 2000

Quantifying the changes of soil microbial biomass and activity of enzymes are important to understand the dynamics of active soil C and N pools. The dynamics of soil microbial biomass C and N and the activity of enzymes over entire growth period of soybean-(Glycine max (L) Merr.)-wheat (Triticum aestivum L.) sequence on a Typic Haplustert as influenced by organic manure and inorganic fertilizer N were investigated in a field experiment. The application of farmyard manure at 4 to 16 $Mg{\cdot}ha^{-1}\;y^{-1}r^{-1}$ along with fertilizer nitrogen at 50 or 180 $kg{\cdot}ha^{-1}$ increased the mean soil microbial biomass from 1.12 to 2.05 fold over unmanured soils under soybean-wheat system. Irrespective of organic and chemical fertilizer N application, the soil microbial biomass was maximum during the first two months at active growing stage of the crops and subsequently declined with crop maturity. The mean annual microbial activity was significantly increased when manure and chemical fertilizer at 8 $Mg{\cdot}ha^{-1}$ and 50/180 N $kg{\cdot}ha^{-1}$, respectively were applied. The C turnover rate decreased by 47 to 72 % when the level of farmyard manure was increased from 4 to 8 and 16 $Mg{\cdot}ha^{-1}$. There were significant correlations between biomass C, available N, dehydrogenase, phosphatase and yield of the crops.

• Asian-Australasian Journal of Animal Sciences
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• v.13 no.7
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• pp.1010-1016
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• 2000

Effect on the bio-mass and nutrient yield of Lemna perpusilla Torry was studied at two nutrient loading frequencies. Six polythene sinks ($6{\times}2{\times}0.5m^{3}$ area) randomly allocated to two treatments having three sinks in each treatment. Each sink containing $6{\times}2{\times}0.35m^{3}$ water body, was changed either daily with 12.6 kg anaerobically fermented cattle manure (effluent) or with 76 kg efluent at six-day interval. Media Kjeldhal-N (40 vs. 36 mg/L; p>0.05) and $NH_3$-N (9 vs 7 mg/L; p<0.05) concentration were higher in daily charged sinks than those charged at six-day interval. However, temperature ($28.48{^{\circ}C}\;vs.\;28.60{^{\circ}C}$) and pH (6.82 vs. 6.84) were sinilar in both groups of sinks. Biomass (93 vs. $80g/m^{2}/d$) and crude protein (1.24 vs. $1.11g/m^{2}/d$) yield were non-significantly (p>0.05) higher in the daily charged than 6-d interval charged ponds. However, dry matter (4.52 vs. 4.15%), organic matter (83 vs. 84%), crude protein (31.4 va. 29.6%) and organic carbon (47 vs. 47%) content were similar in both daily and 6-d interval charged ponds. There were no apparent relationships between the crude protein content of Lemna and the media Kjeldhal-N or $NH_3$-N concentration apparently due to saturated level of nutrient (N in particular). It was concluded that with the level of effluent used for two treatments, nutrient-loading frequency had no significant effect on the biomass and protein yield of Lemna. Technique described here can be used for year-round duckweed production from fermented cattle manure for feeding poultry/fish in smallholder production system.

• The Korean Journal of Malacology
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• v.24 no.3
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• pp.189-197
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• 2008

In order to develop the sustainable ecological management, short-necked clams, Ruditapes philippinarum, were collected from Yoengi coast in Tongyoeng, Korea. The growth of the clam was estimated as: $L_f=68.08{\cdot}(1-e^{-0.145(t+0.324)})$ from ring radius composition of shell. Instantaneous co-efficiency of total mortality and natural mortality were calculated as: 0.991/year and 0.494/year, respectively. The age of the clams from the first capture was estimated to be 3.28. The total biomass was estimated to be 212 MT in the fisheries area (6.4 ha). Applied by these parameters, the annual recruit biomass and the current yield per recruit were calculated to be 649.5 individual/$m^2$ and $0.7\;g/m^2$, respectively. The current fishing intensity was much lower for maximum sustainable yield and acceptable biological catch. Although higher yield per recruit could be achieved by increasing fishing intensity, it is favorable to retain the current fishing intensity because of the unique fishing attitude on Yeongi coast in Tongyoeng, Korea.

• Korean Journal of Microbiology
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• v.21 no.3
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• pp.163-169
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• 1983

Effects of temperature on the gorwth characteristics and the chemical composition of pseudomonas cells grown under glucose-or methanol-utilizing continuous culture were studied. In a glucose-utilizing continuous culture, optimum dilution rate, agitation, pH, and temperature, for the higher biomass yield were $0.45hr^-$, 7000rpm, pH 7.5, and $30^{\circ}C$, respectively. But in a methanol-utilizing continuous culture, they were $0.125hr^-$, 600rpm, pH 8, and $30^{\circ}C$, respectively. In methanol-utilizing continuous culture, the maximum production rate of the cells was 1.48g, dry wt./1/hr at a dilution rate of $0.45hr^-$, and the cell yield was 0.46g. dry wt./g. glucose. In the methanol-utilizaing continuous culture, the maximum production rate of the cells was 0.33 7g. dry wt./1/hr. at a dilution rate of $0.125hr^-$ and the cell yield was 0.44g dry cell/g. methanol. The contents of protein of the cells increase with the increase ingrowing temperature (from 15 to $30^{\circ}C$), more or less, while the contents of RNA nad carbohydrate of the cells decreased. However, DNA contents of cells growth under the various temperature ranges didn't change. As the temeprature of cultivation rises at a constant dilution rate, the efficiency of RNA in protein synthesis was increased, showing the decreases in the ratio of RNA to protein.

• Environmental Engineering Research
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• v.24 no.2
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• pp.354-361
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• 2019

Renewable energy from biomass and biodegradable wastes can significantly supplement the global energy demand if properly harnessed. Pyrolysis is the most profound modern technique that has proved effective and efficient in the energy conversion of biomass to yield various products like bio-oil, biochar, and syngas. This study focuses on optimization of slow pyrolysis of banana peels waste to yield banana peels vinegar, tar and biochar as bio-infrastructure products. Response surface methodology using central composite design was used to determine the optimum conditions for the banana wastes using a batch reactor pyrolysis system. Three factors namely heating temperature ($350-550^{\circ}C$), sample mass (200-800 g) and residence time (45-90 min) were varied with a total of 20 individual experiments. The optimal conditions for wood vinegar yield (48.01%) were $362.6^{\circ}C$, 989.9 g and 104.2 min for peels and biochar yield (30.10%) were $585.9^{\circ}C$, 989.9 g and 104.2 min. The slow pyrolysis showed significant energy conversion efficiencies of about 90% at p-value ${\leq}0.05$. These research findings are of primary importance to Uganda considering the abundant banana wastes amounting to 17.5 million tonnes generated annually, thus using them as pyrolysis feedstock can boost the country's energy status.