• 한국해양학회지
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• v.27 no.3
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• pp.250-258
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• 1992

The oxygen isotope composition of surface waters in the Bransfield Strait was determined as one extra state variable in order to characterize water masses in the region, since salinity is significantly modified due to the freezing and ice-melting in the polar region. The salinity, temperature, and $\delta$/SUP 18/O values vary from 34.0 to 34.5$\textperthousand$, -.05 to 2.1$^{\circ}C$ and -0.50 t -0.26$\textperthousand$, respectively. The combined effects of evaporation, precipitation, freezing, ice-melting are reflected in the widely scattered data. Although it is small, the distribution of $\delta$/SUP 18/O of the Bransfield Strait is strongly affected by the freezing-ice melting rather than the evaporation-precipitation. The ice melted fresh water which has higher temperature, depleted salinity and nutrients may be injected to the Bransfield Strait from the north. The concentrations of nutrients are decreasing gradually from the north to the south. The waters were characterized by two groups of higher (about 19.4) and lower N/P ratio (about 16.7). The lower N/P ratio is found in the northern part where ice-melted fresh water is injected. and the higher N/P ratio is found in the southern part of the Bransfield Strait. Although more precise work is needed, the deference of N/P ratio can be an evidence of the ice melted water injection to the Bransfield Strait. Chlorophyll a concentrations, in general, increase from northwest (Waddell Sea) to the southeast (Smith and Hosseason Islands). Probably the injection of nutrient depleted fresh water from the ice melting reduce the chlorophyll a concentration.

• Korean Journal of Food Science and Technology
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• v.15 no.1
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• pp.56-61
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• 1983

Direct production of biomass from starch using amylolytic yeast, Sporobolomyces holsaticus FRI Y-5 was studied with varying the ratios between carbon and other nutrient sources in the medium. It was investigated under condition of constant C/P and C/S ratio to influence the initial concentration of starch $(S_o)$ and C/N ratio on its growth which is described as the specific growth rate $({\mu})$, cell yield (Y), the maximum concentration of cell $(X_m)$, and productivity (P). They were very dependent on both $S_o$ and C/N ratio. The form of the relationship between and ${\mu}$ and $S_o$ was observed to be similar to saturation kinetics at C/N = 100 but presented substrate inhibition at other C/N ratios. As $S_o$ was changed from 22.5 to 90 g/l, Y was observed to vary with C/N ratios but seemed to decrease as a wholes. $X_m$ was linearly related to $S_o$ at more than C/N = 50 but at less than C/N = 10 substrate inhibition was presented. P increased suddenly to $S_o$ = 45 g/l and then changed decreasingly at less than C/N = 50, but at more than C/N = 100 it changed increasingly. The effect of C/P ratio and C/S ratio on the yeast growth was also investigated at constant $S_o$ and C/N ratio. ${\mu}$ was dependent on C/P and C/S ratios, but Y, independent on them. But $X_m$ was reliant upon C/P ratio but not upon C/S ratio.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.4
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• pp.199-205
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• 2015

Nitrogen and phosphorus are the limiting elements for growth of phytoplankton, which is a major primary producer of marine ecosystem. Incidentally the stoichiometry of N/P of ocean waters, measured by the (nitrate + nitrite)/phosphate ratio converges to a constant of 16. This characteristic ratio has been used widely for the understanding the ecosystem dynamics and biogeochemical cycles in the ocean. In the East Sea, several key papers were issued in recent years regarding the climate change and its impact on ecosystem dynamic and biogeochemical cycles using N/P ratio because the East Sea is a "miniature ocean" having her own meridional overturning circulation with the appropriate responding time and excellent accessibility. However, cited N/P values are different by authors that we tried to propose a single representative value by reanalyzing the historical nutrient data. We present N/P of the East Sea as $12.7{\pm}0.1$ for the year 2000. The ratio reveals a remarkable consistency for waters exceeding 300m depth (below the seasonal thermocline). We recommend to use this value in the future studies and hope to minimize confusion for understanding ecosystem response and biogeochemical cycles in relation to future climate change until new N/P value is established from future studies.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.163-173
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• 2001

This study describes the characteristics of concentrations of pollutants such as total nitrogen(T-N), total phosphorous(T-P), and chemical oxygen demand(COD) at paddy areas during 2-year irrigation periods. The most common order in average concentrations of T-P and COD is podded water > irrigation(or drainage) water > percolated water. Most of pollutants concentrations in drainage water are lower than those in irrigation water after early July due to large uptake of pollutants by rice crop and denitrification. The exponential L (load)-Q(discharge) equations for classified irrigation periods are significant at 0.001 level for irrigation and drainage waters. For drainage water, the concentrations of T-N and COD slightly decrease with discharge, while the T-P concentrations slightly increase with discharge.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.2
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• pp.105-112
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• 2008

The surface and bottom water were sampling in ten stations of the coastal area of Chagwi-Do, Jeju Island, which was repeated 6 times in several different months(September, November, 2004 and March, May, August, and November 2005) in order to examine the physico-chemical characteristics of water. The temperature varied by approximately $16^{\circ}C$, ranging somewhere between 1$12.2^{\circ}C$ and $28.9^{\circ}C$. Specifically, the temperature of bottom water was $13^{\circ}C$, implying the emergence of low temperature water. The salinity ranged from 30.2 to 34.9%o, and the lowest salinity in August may be attributable to the effect of land-based water. N/P ratio, the growth factor of phytoplankton, ranged from 5 to 76, which varied depending on the season and station. The ratio, however, was over 22 on the average, suggesting that phosphate phosphorus is an factor that restricts the growth of phytoplankton. TOC in the concentration of organic carbon ranged between $92.5{\mu}M$ and $438.3{\mu}M$, and the mean was $217{\mu}M$. DOC ranged from $82.5{\mu}M$ to $299.2{\mu}M$, and the mean was $130{\mu}M$. The ratio of DOC/POC was 60% with abundant dissolved organic carbon.

• Food Science of Animal Resources
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• v.22 no.1
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• pp.55-58
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• 2002

The economical producing method of casein phosphopeptide (CPP) and the physicochemical properties related to the solubilization of calcium were studied. Firstly, The compositions of the purified CPP-III were 13.1% of nitrogen, 2.3∼2.4% of phosphate and the ratio of N/P was 5.4∼5.6. In consideration of economic aspects, the preparation method of the CPP- I and II which were lower purity than the CPP-III was established. The physico-chemical property of the CPP was compared with the enzymically dephosphorylated CPP. CPP and polyglutamate effectively inhibited the formation of insoluble calcium phosphates at physiological pH.

• Journal of the Korean Society of Food Science and Nutrition
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• v.15 no.3
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• pp.243-248
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• 1986

This study was examined the contents of calcium, phosphorus, magnesium, sodium, potassium, total nitrogen (total N) and free amino acid in shank bone stock as results of boiling for eight, twelve, sixteen and twenty hours. The results were as follows. 1) Contents of calium, sodium and potassium were increased according to boiling time, Content of calcium was more than two times after boiling for twenty hours as compared with eight hours. The contents of potassium and sodium were increased slightly but that of magnesium was constant in the course of boiling. The content of phosphorus was showed maximum value after toiling for eight hours and was decreased after boiling for twelve hours. 2) The content of total N was increased according to boiling time and showed moximum value after boiling for twenty hours. Total N was extracted more than two times after boiling for twenty hours as compared with eight hours. The content of free amino acid was little at various boiling time. The contents of glycine, glutamic acid and serine were increased according to boiling time. Glycine was the most abundant free amino acid and was followed in order of glutamic acid. alanine and serine.

• The Science & Technology
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• v.11 no.1 s.104
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• pp.8-20
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• 1978

제4차 경제개발 5개년계획 1차년도 과학기술 분야를 회고해 보고 80년대를 향한 과학기술계를 내다보면서 새로운 진로와 방향을 정립해 보는 신년좌담회가 지난13일 과학기술회관에서 있었다. 「전국민의 과학화」를 캣치프레이즈로 내걸고 과학기술풍토 조성사업을 꾸준히 추진해온 과학기술계는 지난 한해동안 경제성장과 함께 수출100억불 달성에 일익을 담당하는 괄목할 만한 수준에 이르렀다. 또한 한국 과학재단, 창원 기능대학 ,9개 연구소의 설립등 과학기술의 장기적인 포석을 마련하는 활발한 움직임을 보여왔다. 하지만 과학기술연구인력의 부족 ,아직은 G.N.P비 0.5%수준인 연구개발 투자를 1%선 이상으로 끌어올려야 하는 등 아직도 과학기술계가 풀어나가야 할 많은 현안문제들이 남아있어. 1980년대 과학한국 기술자립이라는 과제를 부여받은 우리 과학기술계의 임무는 과연 무엇이며 기술자립의 기반은 어떻게 다져나가야 할지 좌담회에 참석한 과학기술인에게 직접 들어본다.

• Korean Journal of Environment and Ecology
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• v.26 no.1
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• pp.74-81
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• 2012

Decay rate and nutrient dynamics during leaf litter decomposition of deciduous Quercus acutissima and evergreen Quercus mysinaefolia were studied for 24 months from December 2008 to December 2010 in Gongju, Chungnam Province, Korea. Percent remaining weight of Q. acutissima and Q. mysinaefolia leaf litter after 24 months elapsed was $46.3{\pm}5.4%$ and $37.8{\pm}2.5%$, respectively. Decomposition of evergreen Q. mysinaefolia leaf litter was significantly faster than that of deciduous Quercus acutissima leaf litter. Decay constant(k) of Q. acutissima and Q. mysinaefolia leaf litter after 24 months elapsed was 0.38 and 0.49, respectively. Initial C/N and C/P ratio of Q. mysinaefolia leaf litter was significantly lower than those of Q. acutissima leaf litter. Initial C/N and C/P ratio of Q. acutissima leaf litter was 46.8 and 270.9, respectively. After 24 months elapsed, C/N and C/P ratio of decomposing Q. acutissima leaf litter decreased to 22.5 and 104.2, respectively. Initial C/N and C/P ratio of Q. mysinaefolia leaf litter was 22.4 and 41.7, respectively. After 24 months elapsed, C/N and C/P ratio of decomposing Q. mysinaefolia leaf litter decreased to 16.7 and 89.7, respectively. Initial concentration of N, P, K, Ca and Mg in leaf litter was 8.31, 0.44, 4.18, 9.38, 1.37 mg/g in Q. acutissima, and 19.88, 2.73, 7.06, 8.24, 2.61 mg/g in Q. mysinaefolia, respectively. Initial concentration of N and P in Q. mysinaefolia leaf litter was significantly higher than those in Q. acutissima. After 24 month elapsed, remaining N, P, K, Ca and Mg were 100.91, 114.75, 32.99, 50.63, 15.51% in Q. acutissima, and 43.22, 11.35, 12.98, 82.22, 44.23% in Q. mysinaefolia, respectively. N and P in decomposing leaf litter was immobilized in Q. acutissima, and mineralized in Q. mysinaefolia.

• Korean Journal of Environment and Ecology
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• v.28 no.5
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• pp.566-573
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• 2014

Decay rate and nutrient dynamics during leaf litter decomposition of deciduous broad leaf Quercus mongolica and evergreen needle leaf Pinus densiflora were investigated for 69 months from December 2005 to September 2011 in Mt. Worak National Park as a part of National Long-Term Ecological Research Program in Korea. Percent remaining weight of Q. mongolica and P. densiflora leaf litter after 69 months elapsed was $35.4{\pm}2.3%$ and $16.1{\pm}1.3%$, respectively. Decomposition of P. densiflora leaf litter was significantly faster than that of Q. mongolica leaf litter. Decay constant (k) of Q. mongolica and P. densiflora leaf litter after 69 months elapsed was 5.97 and 10.50, respectively. Initial C/N and C/P ratio of Q. mongolica leaf litter was 43.1 and 543.9 respectively. After 69 months elapsed, C/N and C/P ratio of decomposing Q. mongolica leaf litter decreased to 8.7 and 141.2, respectively. Initial C/N and C/P ratio of P. densiflora leaf litter was 151.2 and 391.4, respectively. After 69 months elapsed, C/N and C/P ratio of decomposing P. densiflora leaf litter decreased to 22.9. and 136.5. respectively. Initial concentration of N, P, K, Ca and Mg in leaf litter was 9.30, 0.23, 2.36, 3.14, 1.11 mg/g in Q. mongolica, and 3.02, 0.09, 1.00, 3.84, 0.62 mg/g in P. densiflora, respectively. Initial concentration of N and P in Q. mongolica leaf litter was significantly higher than those in P. densiflora. After 69 months elapsed, remaining N, P, K, Ca and Mg in decomposing leaf litter were 73.8, 60.9, 17.2, 20.3, 35.1 % in Q. mongolica, and 69.5, 75.3, 12.3, 10.9, 10.8 % in P. densiflora, respectively.