• 생물환경조절학회지
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• 제11권4호
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• pp.199-204
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• 2002

한국의 인삼재배시 연작장해로 인한 생산량 감소가 문제가 되고 있다 이를 극복하기 위하여 본 연구에서는 한국인삼 재배를 위하여 양액재배 시스템을 적용하였다. 최적의 양액재배용 배지를 선발하기 위하여 모래, TSK-2 (S＋T), 피트모스 (P), 재활용 암면 (RR)과 입상 암면 (GR)등의 다양한 배지를 단독 및 혼합처리구로 사용하였다. RR배지의 경우 전반적인 물리화학적 특성은 기존에 보고된 인삼배지의 토양특성과 유사하였다. S＋T배지는 가밀도가 인삼용 토양보다 높았다 인삼의 지상부 생체중은 RR배지와 S＋T배지에서 높았다. 인삼 뿌리의 생체중 및 건물중은 RR배지에서 가장 높았다. 인삼의 뿌리의 품질적 측면에서 vitamin C함량은 양액재배로 생육시킨 인삼이 토양에서 생육한 인삼보다 높았으나, crude saponin과 ginsenosides 함량에서는 차이를 나타내지 않았다.

• 한국농공학회지
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• 제44권7호
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• pp.64-73
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• 2002

This study was performed to evaluate effects of physical characteristics of both watershed and reservoir on nutrient-chlorophyll relationship in Korean reservoirs. Simple linear models were developed with published data in Korea including 415 reservoirs and 11 multi-purpose dams, and physico-chemical parameters of reservoirs and characteristics relationship of models were analyzed. Theoretical residence time in Korean reservoirs was strongly correlated with the ratio of TA/ST (drainage area + surface area / storage volume) in the logarithmic function. As a result of monthly nutrients-chlorophyll-a regression analysis, significant Chl-a-TP relationship appeared during May～July. The high Chl-a yields per total phosphorus appeared during this time (R$\^$2/=0.51, p<0.001, N= 1088). Chlorophyll-a demonstrated much stronger relationship with TP. than TN. Seasonal algal-nutrient coupling were closely related with N:P ratio in the reservoir water, and it was, in turn, dependent on the monsoon climatic condition (precipitation). Based on the results of regression analysis and high N:P ratio, a major limiting factor of algal growth appeared to be phosphorus during this time. Unlikely TA/ST ratio, DA/SA ratio (drainage area f surface area) was likely to influence directly on the nutrient-Chl-a relationship, indicating that if storage volume and inflowing water volume were the same, algal biomass could be developed more in reservoirs with large surface area. Thus, DA/SA ratio seemed to be an important factor to affect the development of algal biomass in Korean reservoirs. With low determination coefficient of TP-Chl-a relationship, our findings indicated not only nutrient (phosphorus) but also other physical factors, such as DA/SA ratio, may affect algal biomass development in Korean reservoirs, where actual residence time appears to be more closely related to reservoir surface area rather than storage volume.

• 한국토양비료학회지
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• 제48권6호
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• pp.751-760
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• 2015

Management of renewable organic resources is important in attaining the sustainability of agricultural production. However, nutrient management with organic resources is more complex than fertilization with chemical fertilizer because the composition of the organic input or the environmental condition will influence organic matter decomposition and nutrient release. One of the most effective methods for estimating nutrient release from organic amendment is the use of N mineralization models. The present study aimed at parameterizing N mineralization models for a number of organic amendments being used as a nutrient source for crop production. Laboratory incubation experiment was conducted in aerobic condition. N mineralization was investigated for nineteen organic amendments in sandy soil and clay soil at $20^{\circ}C$, $25^{\circ}C$, and $30^{\circ}C$. N mineralization was facilitated at higher temperature condition. Negative correlation was observed between mineralized N and C:N ratio of organic amendments. N mineralization process was slower in clay soil than in sandy soil and this was mainly due to the delayed nitrification. The single and the double exponential models were used to estimate N mineralization of the organic amendments. N mineralization potential $N_p$ and mineralization rate k were estimated in different temperature and soil conditions. Estimated $N_p$ ranged from 28.8 to 228.1 and k from 0.0066 to 0.6932. The double exponential model showed better prediction of N mineralization compared with the single exponential model, particularly for organic amendments with high C:N ratio. It is expected that the model parameters estimated based on the incubation experiment could be used to design nutrient management planning in environment-friendly agriculture.

• Nutrition Research and Practice
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• 제6권1호
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• pp.21-27
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• 2012

Pumpkins have considerable variation in nutrient contents depending on the cultivation environment, species, or part. In this study, the general chemical compositions and some bioactive components, such as tocopherols, carotenoids, and ${\beta}$-sitosterol, were analyzed in three major species of pumpkin ($Cucurbitaceae$ $pepo$, $C.$ $moschata$, and $C.$ $maxima$) grown in Korea and also in three parts (peel, flesh, and seed) of each pumpkin species. $C.$ $maxima$ had significantly more carbohydrate, protein, fat, and fiber than $C.$ pepo or $C.$ $moschata$ (P<0.05). The moisture content as well as the amino acid and arginine contents in all parts of the pumpkin was highest in $C.$ $pepo$. The major fatty acids in the seeds were palmitic, stearic, oleic, and linoleic acids. $C.$ $pepo$ and $C.$ $moschata$ seeds had significantly more ${\gamma}$-tocopherol than $C.$ $maxima$, whose seeds had the highest ${\beta}$-carotene content. $C.$ $pepo$ seeds had significantly more ${\beta}$-sitosterol than the others. Nutrient compositions differed considerably among the pumpkin species and parts. These results will be useful in updating the nutrient compositions of pumpkin in the Korean food composition database. Additional analyses of various pumpkins grown in different years and in different areas of Korea are needed.

• Journal of Microbiology and Biotechnology
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• 제25권1호
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• pp.109-118
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• 2015

Open raceway ponds are cost-efficient for mass cultivation of microalgae compared with photobioreactors. Although low-cost options like wastewater as nutrient source is studied to overcome the commercialization threshold for biodiesel production from microalgae, a cost analysis on the use of wastewater and other incremental increases in productivity has not been elucidated. We determined the effect of using wastewater and wavelength filters on microalgal productivity. Experimental results were then fitted into a model, and cost analysis was performed in comparison with control raceways. Three different microalgal strains, Chlorella vulgaris AG10032, Chlorella sp. JK2, and Scenedesmus sp. JK10, were tested for nutrient removal under different light wavelengths (blue, green, red, and white) using filters in batch cultivation. Blue wavelength showed an average of 27% higher nutrient removal and at least 42% higher chemical oxygen demand removal compared with white light. Naturally, the specific growth rate of microalgae cultivated under blue wavelength was on average 10.8% higher than white wavelength. Similarly, lipid productivity was highest in blue wavelength, at least 46.8% higher than white wavelength, whereas FAME composition revealed a mild increase in oleic and palmitic acid levels. Cost analysis reveals that raceways treating wastewater and using monochromatic wavelength would decrease costs from 2.71 to 0.73 $/kg biomass. We prove that increasing both biomass and lipid productivity is possible through cost-effective approaches, thereby accelerating the commercialization of low-value products from microalgae, like biodiesel.

• 한국환경과학회지
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• 제13권10호
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• pp.911-919
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• 2004

The purpose of this research was evaluated economical effect to apply alternative external carbon source. Conventional activated sludge process in municipal wastewater treatment plant was adapted and introduced to Biological nutrient removal processes to meet the newly enforced effluent quality standard for nutrient removal in Korea. Low $COD/NH_4^+-N$ ratio and higher nutrient concentration of influent characteristics force to inject external carbon source for denitrifying recycled nitrate. In the most case, methanol was used as external carbon source. But Methanol is expensive and very dangerous in handling. So we could find cheaper and safer external carbon source substituted methanol in last study. This alternative external carbon source is named RCS(recoverd carbon source) and a by-product of fine chemical product at chemical plant. When RCS was applied real municipal wastewater treatment plant, average $55\~65\%$ of T-N removal efficiency, 8.8mg/l of effluent T-N concentration, 11.3mg/l of effleunt COD concentration were obtained without effluent COD increase as against used methanol. To apply RCS in municipal wastewater treatment plant obtain approximately $\74.5%$ expenditure cost reduction in comparison with methanol dosage cost.

• 한국초지조사료학회지
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• 제12권3호
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• pp.185-192
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• 1992

This experiment was conducted to compare the productivity of five silage corn varieties. Corn varieties were Pioneer 3144(P 3144), 3160(P 3160), 3282(P 3282), 3352(P 3352) and Suweon 19(S 19) and were seeded on May 2 and harvested on August 15. Ratios of stalk, leaf and ear, chemical composition and yields of nutrients were investigated in respective corn part. Experimental design was accepted by Latin square arrangement with five replicates and each plot had twenty two plants. The results obtained were as follows: 1. Crude portein, crude ash and nitrogen free extract(NFE) contents of whole plant ranged from 6.32 to 7.18%, 5.16 to 7.43% and 52.62 to 57.90%, respectively, and there were no significant(P>.Ol) differences between varieties. Crude protein and NFE content were the highest in ear between corn parts. 2. Crude fiber conent of whole plant ranged from 18.98 % to 24.01 %, and was the highest in suweon 19 and the lowest in P 3352(P<.01). Crude fiber content was the highest in stem and the lowest in ear, However, crude fat content(2.03-3.66 %) vice versa. 3. Yields of organic matter, crude protein, crude fat, NFE and TDN per 10a were the greatest(P< .01) in P 3282, however crude fiber yield was the highest(P<.Ol) in P 3352. 4. Ratios of different part to total dry matter yield ranged from 12.7 %(P 3352) to 17.8 %(P 3160) for leaf, 44.5(P 3352) to 66.9 %(P 3160) for stem and husks, and 16.9 %(P 3282) to 42.8 %(P 3352) for ear, and there were significant differences between corn varieties(P<.Ol). Consequently, P 3352 has the greatest nutrient yields, particularly by ear, and P 3282 has a great nutrient yield by stem. This result suggested that could be appear a better character of silage corn by hybridization of this two corn varieties.

• 한국유기농업학회지
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• 제13권2호
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• pp.211-221
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• 2005

This experiment was conducted to evaluate the effect of animal slurry on nitrogen uptake of hairy vetch and growth of chinese cabbage in cropping system. Hairy vetch was seeded on September 20 in 2003 . We examined the effect of cover crop(hairy vetch (Vicia villosa Roth) and slurry application(0, l00, 200kg N/ha) on yield and N uptake. Dry matter yield and nitrogen uptake of hairy vetch were measured. The chinese cabbage succeeding cover crop was harvested in 2004. The nitrogen uptake of hairy vetch was 84, 121, 148kg N/ha respectively, when the slurry application was 0, 100 and 200kg N/ha. In addition. N uptake of hairy vetch at the plot of 100kg and 200 kg N/ha slurry were 44% and 76% higher than that of the plot without slurry application respectively. Slurry application of hairy vetch could increase nitrogen uptake by application of green manure at the harvesting time. the content of organic matter and P-content of soil with hairy vetch plot was higher than that of fallow plot due to inhibition of soil erosion. The organic matter levels tend to improve with the addition of hairy vetch. Hairy vetch could improve soil quality by reducing erosion compared with bare fallow. The green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage. The hairy vetch residues decomposed rapidly releasing half of their residues within 40 days after burial. The yield of chinese cabbage was 90% in the plot of manure of hairy vetch compared with chemical fertilizer. The yield in the plot treated with green manure of hairy vetch and 50% of chemical fertilizer was reduced 5% less than that of chemical fertilizer. Therefore, it was estimated that the green manure of hairy vetch-chinese cabbage cropping system could reduce nitrogen chemical fertilizer as much as 84~148kgN/ha. the green manure of hairy vetch with animal slurry maintained soil nutrient and reduced nitrogen fertilizer of chinese cabbage.

• Fisheries and Aquatic Sciences
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• 제6권4호
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• pp.194-202
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• 2003

Budgets for water, nitrogen, and chemical oxygen demand (COD) were determined in two 0.012 ha earthy-bottom ponds stocked with Israeli strain common carp at an initial stocking density of $20\;fish/m^3$. Total ammonia nitrogen (TAN) concentrations increased continuously but later decreased in pond A as a consequence of high nitrification. COD concentrations increased during the experimental period due to the accumulation of feed input. Nutrient budgets showed that feed represented $94-95\%$ of nitrogen input and about 99% of organic matter input. Fish harvest accounted for $40\%$ of nitrogen and organic matter input. Seepage and water exchange removed $15-17\%$ of nitrogen input but only $1-2\%$ of organic matter. Draining of the ponds removed $20-26\%$ of input nitrogen, mostly in inorganic forms, but removed only minus organic matter. Fish and water column respiration accounted for $39\%$ of organic matter input, and benthic respiration accounted for $7-12\%$ of organic matter input. No significant change of nitrogen and organic matter in both pond bottoms were found during the three-month growth period. The unrecovered input nitrogen, about $6.3-13\%$, was lost through denitrification and ammonia volatilization. On a dry matter basis, fish growth removed $31\%$ of total feed input and left $69\%$ as metabolic wastes.

• KSBB Journal
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• 제28권3호
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• pp.151-156
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• 2013

${\beta}$-Glucan type oligomers which have angiotensin I converting enzyme (ACE) inhibitory activity were isolated and characterized from Capsosiphon fulvescens. After C. fulvescens was hydrolysis with Alcalase at $50^{\circ}C$, supernatant was harvested and separated with ultrafiltration membrane (MWCO 2 kDa). Oligomers which were less than 2 kDa of molecular weight were harvested for characterization. The nutrient composition of Alcalase hydrolysate was 89.9% carbohydrate, 4.2% protein and 5.9% sulfate. After ultrafiltration, the nutrient composition of oligomers was changed to 99.88% carbohydrate, 0.07% protein and 0.05% sulfate. The carbohydrate composition of oligomer was glucose (97.2%) and mannose (1.5%). The ACE inhibitory activities of Alcalase hydrolysate and oligomer were 72.1% and 82%, respectively. The molecular weight of oligomer was about 1 kDa. The oligomer was analyzed with FT-IR, $^1H$-NMR and methylation. The oligomers were ${\beta}$-1,3-glucans with ${\beta}$-(1,3)-linked glucose units.