• Korean Journal of Soil Science and Fertilizer
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• v.49 no.2
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• pp.181-193
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• 2016

This experiment was conducted to evaluate the effect of carbonized rice hull (CRH) application on soil carbon storage and $N_2O$ emissions from upland soil. It was used at different rates of 0, 5, 10 and $20Mg\;ha^{-1}$. During the Chinese cabbage cultivation, several soil chemical characteristics such as soil moisture, temperature and soil carbon were observed. Also, $CO_2$ and $N_2O$ emissions were monitored. Soil organic matter contents slightly increased with carbonized rice hull applied in all the treatments. The soil carbon contents with application rate of 0, 5, 10 and $20Mg\;ha^{-1}$ were 0, 1.3, 1.2 and $2.6g\;kg^{-1}$, respectively. It was observed that soil carbon content was higher with increasing CRH application rate. Total nitrogen contents of soil applied with CRH relatively decreased with the course of time. However, $NO_3$-N contents in the soil with CRH application rate of 5, 10 and $20Mg\;ha^{-1}$ were 28.6, 25.7 and $21.5mg\;kg^{-1}$ at the end of experiment, respectively. $CO_2$ emission at the $5Mg\;ha^{-1}$ application of CRH was higher about 18.9% than non-treatment, whereas those of $10Mg\;ha^{-1}$ and $20Mg\;ha^{-1}$ treatment were lower 14.4% and 11.8% compared to non-treatment, respectively. Also, it was shown that $N_2O$ emission reduced by 19.9, 28.3 and 54.0% when CRH was applied at 5, 10 and $5Mg\;ha^{-1}$, respectively.

• The Korean Journal of Food And Nutrition
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• v.15 no.1
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• pp.29-35
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• 2002

N-nitrosamine(NA) contents depending on simulated gastric digestion were analyzed with 12 kinds of diets collected from institutional food service those diets were estimated the total NA amounts including both intake from food directly and its endogenous formation in human body from simulated gastric digestion. NA was determined in dishes of meats, fishes and vegetables before and after simulated gastric digestion. Before digestion, N-nitrosodimethylamine (NDMA) contents ware from not detected(ND) to 4.8$\mu\textrm{g}$/kg in dishes of meats and fishes. After digestion, its contents increased and the highest level was 3.0 $\mu\textrm{g}$/kg in panbroiled dried anchovy. In vegetable dishes, NDMA was detected as ND∼trace before and after digestion. The contents of NDMA in diets collected from institutional food service were 0.20∼0.78$\mu\textrm{g}$/kg 0.43 ∼ 0.80$\mu\textrm{g}$/kg before and after digestion, respectively. The average intake of NA per day to Korean, based on the above data, was 0.60 ∼ 2.34$\mu\textrm{g}$/day/ person. The maximum daily intake of NA was deduced to 5.15$\mu\textrm{g}$/day/person when considering NA amounts formed endogenously by simulated gastric digestion.

• Journal of Marine Bioscience and Biotechnology
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• v.8 no.2
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• pp.45-53
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• 2016

Most of microalgae shift their metabolic pathways toward the fatty acid biosynthesis following nitrogen deprivation. Recent studies on Nannochloropsis species, oleaginous microalgae, have been performed to investigate the regulation of contents and compositions of fatty acids under stressful condition. The objective of this experiment is to identify the effect of nitrogen on cell growth and fatty acids production in Nannochloropsis oculata K-1281 and compare fatty acid composition response to nitrogen deficiency between N. oculata LB2164 and K-1281. The fatty acids content in N. oculata K-1281 was increased up to 210%, while the growth rate was decreased under nitrogen deficient condition. The contents of C16:0 and C16:1 increased dramatically in both N. oculata K-1281 and LB2164, while the contents of C20:4 and C20:5 increased in N. oculata LB2164. The fatty acids content and composition in N. oculata K-1281 returned following addition of nitrogen after nitrogen starvation. These results demonstrated that fatty acid contents and compositions under nitrogen deficiency will provide the understanding of fatty acid synthesis in microalgae.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.51 no.6
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• pp.640-646
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• 2018

To determine whether there are differences in the food component characteristics of the cultured recessive small-sized abalone Haliotis discus hannai (SA; 30-40 each/kg) and middle-sized abalone (MA; 10-15 each/kg), the proximate compositions, fatty acid and total amino acid compositions of these two species were evaluated. Additionally, extraction methods were performed on the SA to asses the quality characteristics of the resulting. In terms of proximate composition, MA had lower moisture and carbohydrate levels and higher crude protein contents than SA. The total amino acid contents of MA and SA were 15,734.4 and 11,379.1 mg/100 g, respectively, the major amino acids were glutamic acid, aspartic acid, serine, glycine, alanine, leucine, arginine and lysine, and the major fatty acids were 16:0, 18:0, 18:1n-9, 18:1n-7, 20:4n-6, 20:5n-3, and 22:5n-3. The pH levels and total nitrogen and amino nitrogen contents of the hot-water extract (WE) and scrap enzyme hydrolysate (SE) samples from the SA were 6.32 and 6.05, 1.36% and 1.52%, and 342.1 and 403.1 mg/100 g, respectively. The extraction yields and free amino acid contents from SA were 1,317 and 440 mL/kg, and 8,721.1 and 9,070.7 mg/100 g, respectively, and the concentrations of major components were as follows: arginine, glycine, glutamic acid, alanine and lysine. Additionally, the complex extract (WE+SE) was superior to the traditional extract (WE) in terms of extraction yield, amino-nitrogen content, and organoleptic qualities but not odor.

• Journal of the Korean Society of Tobacco Science
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• v.9 no.1
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• pp.27-33
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• 1987

This study was carried out to investigate the effect of cultural practices on the nicotine and sugar contents in flue-cured tobacco(NC82), and the relationship between them. Significant reduction I sugar content and ratio of total sugar to nicotine(ratio, S/N) were observed with increased fertilizer, lower topping height, late transplanting and decreased application of male hydrazide(MH). Significant increases were observed in nicotine content with increased fertilizer and lower topping height. A positive correlation was found between total sugar content and plant density. A negative correlation was found between nicotine and total sugar contents for 8-years. An increase of 1.0% nicotine in the cured leaf would result in a 4.8% reduction in total sugar. The most desirable contents were 2.7% for nicotine and 19.0% for total sugar(S/N=7).

• Journal of the Korean Ceramic Society
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• v.24 no.3
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• pp.277-281
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• 1987

The various contents of MgF2 from 0 to 12.5wt% are studied in the AlF3-(Mg＋Sr＋Ba)F2-P2O5 system for the effects of various properties in glasses and the atmosphere of melting was controlled by N2 and Ar gas respectively. Density, refractive index, infrared transmission, thermal conductivity and thermal expansion coefficient of glasses are determined. Density, refractive index and thermal conductivity are decreased, micro-hardness and thermal expansion coefficient are increased according to the increasing of MgF2 contents. Infrared transmittance decreases with increasing the MgF2 contents and it slightly dropped by air than N2 and Ar atmosphere. Other properties are not influenced by atmosphere control.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.1
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• pp.68-72
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• 1994

Six brands of encapsulated fishoil products and five fishes were analyzed for their contents of eicosapentaenoic acid (EPA 20 :5 n-3) , docosahexaenoic acid(DHA 22: 6 n-3) and tocopherols. In both of the fish oil products and the fishes, major fatty acids were palmitic acid, oleic acid, eicosapentaeoic acid and docosahexaenoic acid and fatty acid compositions were also similar pattern each other. EPA showed variable amounts from 19.2 to 50.3% in the oil products whereas DHA were 13.2% to 28.3% inthe fishes. Tocopherols were studied in relation to the oxidative stability of fish products no relation was observed. However the amount of tocopherols in fish oil proudcts were higher than that of fishes. Contents of EPA, DHA and tocopherols in encapsulated fishoil products oil products were variable comparing with manufactures' claimed contents.

• Plant Resources
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• v.4 no.1
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• pp.48-52
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• 2001

Seven genetic lines of Bupleurum falcatum L. from different geographical regions were analysed for saikosaponin contents and chromosomal numbers. The somatic chromosome numbers of B. falcatum originated from Euisong, Iri, Milyang, Sangnam, Taejon, and Youngchon were 2n=20 while Mishimasaiko showed 2n=26. However, chromosome features were different in plants grown in different geographical regions. Generally, Korean lines had higher saikosaponin contents than Mishimasaiko which is Japanese and Sangnam lines had highest saikosaponin contents compared to other tested lines.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.1379-1394
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• 1993

The purpose of this study is to examine the purification efficiency of the septic tank method which has been applied by the most of Korean livestock farms, in terms of anaerobic and aerobic treatment. Except several days in summer, BOD of effluent shows 1,500 -3,000 ppm by anaerobic process. In most cases , it exceeds according to the seasons show an increase by decrease of temperature. The removal effect on T-N is hardly found. The suspended solids contents of effluent are reduced to the level of 50-90%. Although BOD contents of effluent are kept high in the beginning, the removal rate of BOD shows 80 percent in the latter half by the aerobic treatment . The removal efficiency of total nitrogen does not appear through the experimental period, but the contents of T-N are not increased in the aerobic process unlike in the anaerobic process. The total phosphorous contents in effluent keep a constant level of 14 mg/L in average. The removal rate of phosphorous shows 91 percent i the last stage.

• Journal of Plant Biology
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• v.36 no.4
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• pp.363-370
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• 1993

Experiments with non-nodulated alfalfa (Medicago sativa L. cv, Europe) plants grown in hydroponic cuiture, were carried out to estimate the remobiJization of nitrogen (N) reserves and to investigate the transported forms of reduced soluble-N in xylem during regrowth following shoot removal. Endogenous N remobilization were estimated by $^{15}N$ labelling and amino acids in xylem sap were analysed. The, $^{15}N$ contents of ~egr9wing leaves and stems increased as a result of remobilization of N reserves mainly from root ,system, Regrowing leaves were a stronger sink than regrowing stems, with about tWo-thirds of remobilized 15N being recoved in leaves. Endogenous N in lateral roots accounted for about 46% of the total N reserves used for regrowth, while tap roots accounted for 23%, About 72% of total endogenous N remobilized to regrowing shoot, occurred during the first 10 days of regrowth, The outflow of reduced soluble-N (mainly amino acids) was greater than that of protein-N, while the latter was the largest storage pool in tap root and lateral roots. It is suggested that amino acids-N was the most readily avaiable form of N reserves. Asparagine, which repre5ented about 75% of amino acids-N in xylem sap, was the main transported form of reduced N. Its relative contents, during the first 10 days of regrowth, decreased from 75% to 59%. This decline was accompanied by compensatory increase in the relative contents of asparatate and glutamine.