• Asian Journal of Turfgrass Science
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• v.9 no.1
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• pp.53-74
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• 1995

This study was made on the relationships among production structures, biomass and Soil proper-ties of grassland types in Chejudo. The results of this investigation were obtained as foolows. The annual productions of the grasslands of Zoysio, Imperata, Themede, Miscanthus and Pteridium types were 40.36~144.00, 168.28~272.44, 58.24~138.44, 156.12 ~714. 12 and 157. 18~398.40g /m$^2$, respectively. The production structures of those grassland types were different from one another. The water contents, organic matter, total nitrogen and available phosphorus were different levels between grasslands had a simple correlation at 5% level and the organic matter contents were a higher significant at the partial correlation. Key words: Production Structure, Biomass, Soil properity, Chejudo.

• Journal of Microbiology and Biotechnology
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• v.10 no.2
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• pp.201-207
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• 2000

The freshwater green alga Chlorococcum sp. grew on NH_4^{+},{\;}NO_3^{-}$, urea, yeast extract, and peptone as the nitrogen source showing similar pattens of growth and secondary carotenoid (SC) production. However, the most suitable nitrogen source for the induction fo SC was urea. The dffects of nutrient levels (urea, phosphate, sulfate, ferrous iron, and salt) on growth and SC production were stydied by varying the concentration of each nutrient in batch cultures. High biomass production was achieved in cultures containing 20-28 mM urea, 4.8-10 mM phosphate, 1.6 mM sulfate, 70 mM phosphate, 1.6 mM sulfate, 170 mM NACl, and $50{\;}\mu\textrm{M}$ iron. The optimum concentrations of nutrients for biomass and for the SC accumulation in biomass were evaluated and the two media for achieving high biomass production and SC production were thus developed. The extent to which each parameter to stimulate the formation of SC in the alga were varied and the potentially improned SC prodution by manipulating the nutrient levels in the modified media were descussed.

• Journal of Korean Society of Forest Science
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• v.90 no.6
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• pp.692-698
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• 2001

This study has been carried out to estimate aboveground biomass and net primary production(NPP) in an average 41-years-old Quercus variabilis stand of Gongju area, 45-years-old Quercus variabilis stand of Pohang area, and 54-years-old Quercus variabilis stand of Yangyang area. Ten sample trees were cut in each forest and soil samples were collected in July to August, 2000. Estimation for aboveground biomass and net primary production were made by the equation model $Wt=aD^b$ where Wt is oven dry weight in kg and D is DBH in cm. Total aboveground biomass was 91.31ton/ha in Gongju area, 207.6ton/ha in Pohang area, and 71.39ton/ha in Yangyang area. The aboveground biomass 207.6ton/ha in Pohang area is the highest biomass production among the amount of biomass in Quercus variabils stands reported in Korea. The proportion of each tree component to total aboveground biomass was high in order of bolewood, bolebark, branches and leaves in the three forests. Aboveground total net primary production was estimated at 7.8ton/ha in Gongju area, 11.5ton/ha in Pohang area, and 6.40ton/ha in Yangyang area. There were at least 2 times higher total aboveground biomass in Pohang area than in the Gongju and Yangyang areas because of climate difference among the study areas.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.21-22
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• 2019

In order to prevent global warming according to fossil fuel use, countries around the world are making efforts through the Kyoto Protocol and the Paris Climate Change Convention. In addition, in order to prepare for high oil prices, researches such as the development of various renewable energy are being conducted. At present, the domestic production rate of energy sources in Korea is low at 18.1%, and power plants using forest biomass are being constructed to meet the domestic situation where 63% of the land is a forest. In 2015, the global production of wood pellets, a raw material for wood-based biomass power generation, was 28 million tons, up 7.7% from 2014, and has increased tenfold over the last decade. This is a result of increased demand for biomass. Korea is also increasing every year. However, biomass fly ash, an industrial by-product generated by biomass energy generation, is now being disposed of entirely, and there is little research to utilize it. Therefore, this paper will use biomass fly ash, an industrial by-product, which is currently being discarded due to a lack of separate treatment methods, as an admixture concept to contribute to solving environmental problems, developing new admixtures, improving quality, and seeking recycling plans.

• Microbiology and Biotechnology Letters
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• v.46 no.4
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• pp.377-389
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• 2018

In this study, a novel microalgal strain, Desmodesmus sp. KAERI-NJ5, was isolated, identified, and evaluated as a candidate for biodiesel feedstock. In a preliminary study, the effects of four general microalgal growth factors, including temperature, pH, light intensity, and concentration of nitrogen source ($KNO_3$), on the microalgal photoautotrophic growth were evaluated. With the exception of light intensity, the growth factors needed to be optimized for the microalgal biomass production. Optimization was done using response surface methodology. The optimal conditions for biomass production were pH 6.54, $27.66^{\circ}C$, and 0.52 g/l $KNO_3$. The biomass production at the optimal conditions was 1.55 g/l, which correlated well with the predicted value of 1.5 g/l. The total lipid and fatty acid methyl ester contents of the cells grown at the optimal conditions were 49% and 21.2% of cell dry weight, respectively. To increase the lipid content of the biomass, microalgae were challenged by nitrogen starvation. Enhancement of total lipid and fatty acid content up to 52.02% and 49%, respectively, were observed. Lipid analysis of the nitrogen-starved cells revealed that C16 and C18 species accounted for 95.9% of the total fatty acids. Among them, palmitic acid (46.17%) and oleic acid (39.43%) dominantly constituted the algal fatty acids. These results suggest Desmodesmus sp. KAERI-NJ5 as a promising feedstock for biodiesel production.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.7
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• pp.956-959
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• 2001

Three perennial grasses, Napier (Pennisetum purpureum), Andropogan (Andropogan gayanus) and Para (Brachiria mutica), were grown at different hill heights dividing the hill slope into three regions (top, middle and bottom). The first two grasses gave the highest biomass yields (29.9 and 37.6 tonnes/ha/harvest, respectively) followed by Para (20.5 t/ha). No significant (p>0.05) changes in biomass yields of the grasses were found due to differences in hill heights. The grasses were harvested three times in the first year of cultivation. Maize and cowpea as sole crops or their intercrops were cultivated in the plain land and the intercrop gave the highest biomass yield (46.7 t/ha, p<0.05). The biomass produced was successfully ensiled in the underground pits at the hill tops.

• Journal of The Korean Society of Agricultural Engineers
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• v.64 no.5
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• pp.1-8
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• 2022

Hydrogen can be produced by gasification of biomass and other combustible fuels. Depending on oxydant agents, syngas or producer gas compositions become quite different. Since biomass has limited amount of hydrogen including moisture in it, the hydrogen concentration in the syngas is about 15% when air is supplied for oxidant agent. Experiments were conducted to investigate the channges in hydrogen concentrations in syngas with different oxidant agent conditions, fuel conditions, and external heat supply. Allothermal reaction resulted in higher concentrations of hydrogen with the supply of steam over air, reaching over 60%. Hydrogen is produced by water-gas and water-gas shift reactions. These reactions are endothermic and require enough heat. Autothermal reaction occurred in the downdraft gasifier used in the experiment did not provide enough heat in the reactions for hydrogen production. Steam seems a more desirable oxidant agent in producing the syngas with higher concentrations of hydrogen from biomass gasifications since nitrogen is included in syngas when air is used.

• Applied Chemistry for Engineering
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• v.33 no.2
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• pp.145-150
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• 2022

Microalgae are attracting attention as a resource for the production of biofuels, food nutrients, biochemicals, and bioplastics. Among a wide range of sources of the biomass, microalgae have been highlighted due to relatively easy cultivation, ability to eliminate carbon dioxide, and low culturing cost. Despite the great potential of microalgal biomass as a biological material, the complexity and relatively expensive downstream processes have inhibited the commercial use of microalgae. In this study, we reviewed recent techniques for microalgal drying for the production of microalgal based products. As drying processes comprise the largest portion of microalgae processing cost, an efficient drying technique is key to the utilization of microalgal biomass.

• Journal of environmental and Sanitary engineering
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• v.14 no.3
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• pp.123-129
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• 1999

The utilization methods of algae biomass have been studied constantly in whole world. These are $\circled1$the wastewater treatment if waste stabilization pond and oxidation ditch etc. and $\circled2$the biosorption of heavy metals and recovery of strategic' precious metals and $\circled3$the single-celled protein production and the production of chemicals like coloring agent and $\circled4$the production of electric energy through methane gasification. The culture system also has been developed constantly in relation with such utilization method developments. In the result of experimental operation under continuous and cyclic irradiation of light, using high rate algae biomass culture pond(HRABCP), which had been made so as to be an association system with the various items which had been managed to have high efficiency for algae culture, the algae production of the 12 hours-irradiance pond was 41.48 Chlorophyll-a ${\mu}g/L$ only in spite of having the more chance of $CO_2$ synthesis to algae cell than the 24 hours-irradiance pond. This means that the energy supply required for dark-reaction of photosynthesis is very important like this. The difference of algae production between continuous and cyclc irradiation explains that the dark-reaction of photosynthesis acts on algae production as the biggest primary factor. The continuous irradiance on HRABCP made the good algae-production($1403.97{\;}{\mu}g$ Chlorophyll-a/mg) and the good oxygen-production(5.8 mg $O_2/L$) and the good solid-liquid seperation. especially, DO concentration through the oxygen-production was enough to fishes' survival.

• Journal of Korean Society of Forest Science
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• v.65 no.1
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• pp.54-59
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• 1984

Research was conducted in a minirotation plantation with four different planting densities at Tatae-ri, Chongwoon-myon, Yangpyong-gun, Kyonggi-do, to investigate the relation between volume and biomass production. Nine-year-old Alnus hirsuta var. sibirica analyzed to determine volume yield and weight equations for aboveground parts. The results suggest that the most suitable harvesting or thinning period at highly dense plots, more than 6,000 trees per hectare, is five years after planting, and the most fitted regression equation model for estimating aboveground biomass or total tree biomass is $logY=b_0+b_1logd^2h$.