• Journal of The Korean Society of Grassland and Forage Science
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• v.23 no.1
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• pp.43-48
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• 2003

The effect of rare earth(RE) at three difference levels of nitrogen on the growth and nitrate content of chicory (Cichorium intybus L.) were studied in terms of leaf size, fresh and dry weight increase, and chlorophyll and nitrate content grown in plastic pots within glasshouse. Leaf size was enlarged as the level of nitrogen applied was high, and leaf within, length, and thickness of leaf were increased by RE treatment showing significant difference at high nitrogen(N+1) plot. As the level of nitrogen applied was high, as fresh and dry weight per plant was increased significantly(p<0.05), and sprinkling cabbage with RE increased fresh and dry matter yield to 2∼12, 4∼6.2% more, respectively. Dry matter content of Chinese cabbage was increased by RE sprinkling. At all levels of nitrogen fertilized chlorophyll contents were increased by RE treatment. As the level of nitrogen was high, as the content of chlorophyll was highly increased by RE. Nitrate was accumulated more at high level of nitrogen application, but nitrate was decreased by RE application, 40% decrease at very high nitrogen plot(N+2). RE stimulated the growth of chicory with high chlorophyll content, and showed the possibility producing high quality agricultural products low in nitrate content.

• Journal of The Korean Society of Grassland and Forage Science
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• v.30 no.2
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• pp.127-134
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• 2010

A study was conducted to determine the effects the of cattle manure application on forage yield, quality and soil in orchard grass pasture at the experimental field of Subtropical Animal Experiment Station, National Institute of Animal Science from 2008 to 2009. The experiment was arranged in a randomized complete block design with three replications. The treatment consisted of chemical fertilizer (CF N-200 kg/ha), cattle manure 50% (basis N, CM50%), CM100% (basis N), CM200% (basis N). The dry matter (DM) yield of CM200% was the highest among the other treatments. CF showed the highest average crude protein (CP) content by 12.4% and CM50% showed the lowest content by 11.0%. Average acid detergent fiber (ADF) and neutral detergent fiber (NDF) content were 30.4 and 69.7% respectively. All treatments have narrow range of total digestibility nutrient (TDN) from 64.0% to 69.1%. But there were big difference between treatment in forage nitrate content. Changes of physical and chemical properties of soils for applications of CF 200% and CM 200% was clearly in cattle manure application. Especially, CM application in pasture increased CF application with respect to soil pH, organic matter (OM), and avaliable phosphorous ($P_2O_5$) contents of soils.

• Clean Technology
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• v.3 no.2
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• pp.87-93
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• 1997

A new process has been developed for nitrate and other salts removals from polluted waters. Alumina cement and calcium oxide served as precipitating agents to remove nitrate with stirring at basic pH. Low content of alumina in the commercialized alumina cements resulted in a increasing in nitrate removal yield. It is found that the compositions of aluminium and calcium are the most important factors in successful nitrate insolubilization. In order to remove high concentration of nitrate in polluted water, multi-stage precipitation was found to be very effective. Sulfate, chloride, and phosphate ions as well as nitrate were also removed by the precipitated reaction. After precipitation, post-treatments including Na2CO3 addition and neutralization with acid alleviated the level of aluminium and calcium in the treated water.

• Korean Journal of Materials Research
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• v.5 no.8
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• pp.905-912
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• 1995

Influences of the starting salts on the phase and morphology of the Pb(Zr, T)O$_3$powders prepared by ultrasonic spray pyrolysis were studied. The Phases of the Powders Prepared from the combination of metal nitrate(or oxynitrate), acetate(or oxyacetate), and alkoxide were the Pb(Zr, Ti)O$_3$with or without minor PbTiO$_3$. The pores on the surface of the spherical particles increased with the nitrate content in the starting solution and their formation was thought to result from the decomposition characteristics of metal nitrate. Pb acetate, Zr oxyacetate, Ti oxynitrate, and Ti (isopropoxide+acetylacetonate) was suitable as the starting salts for the preparation of Pb(Zr, Ti)O$_3$powders by ultrasonic spray pyrolysis in the viewpoint of the phase and morphology of the powders.

• Economic and Environmental Geology
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• v.45 no.1
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• pp.23-30
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• 2012

Major ions and nitrogen isotopic analyses were performed to determine the geochemical characters and to identify the source of nitrate of the shallow groundwater around agricultural field in the Youngdong area. The pH value of groundwater ranges from 60. to 8.2 (pH 7.2, mean). The average of EC, Eh and DO is 369 ${\mu}S/cm$ (70~729 ${\mu}S/cm$), 165.6 mV (29~383.2 mV), 4.3 mg/L (1.8~8.0 mg/L) respectively. The ion concentraion of groundwater was in the order of $Ca^{2+}$>$Na^{2+}$>$Mg^{2+}$>$K^{2+}$ and ${HCO_3}^-$>${NO_3}^-$>${SO_4}^{2-}$>$Cl^-$>$F^-$. Most of groundwater is Ca-$HCO_3$ type. The groundwater was affected by water-rock interaction in the shallow depth. Some groundwater is Ca-Cl or Na-$HCO_3$ (2.5%) type that was due to agricultural activities. The $NO_3$_N concetration of grondwater range from 10.2 mg/l to 26.9 mg/l, which show that this area is under nitrate pollution. ${\delta}^{15}N-NO_3$ value of the groundwater is the origins of are a combination of animal wastes and man-made fertilizers.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.27 no.3
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• pp.247-258
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• 1994

A total of 31 commercial dried marine food products, consisting of 14 fishes, 2 shellfishes and 2 seaweeds species were analyzed for their contents of precusors of N-nitrosamine such as dimethylamine(DMA), trimethylamine(TMA), trimethylamine oxide (TMAO), betaine and nitrate and nitrite nitrogen as factors of N-nitrosamine formation. Carcinogenic N-nitrosamines were extracted by a steam distillation apparatus and were analyzed for their components using a gas chromatography-thermal energy analyzer. N-nitrosodimethylamine(NDMA) was confirmed by a gas chromatography-mass spectrometry. The contents of betaine nitrogen in samples were in the range of $5.2{\sim}373.8mg\%$ and were significantly higher than tertiary amines such as TMA and TMAO. DMA nitrogen in those samples was in the range of trace-31.2ppm and was high, in the dried shark(31.2ppm), alaska pollack($22.9{\sim}24.3ppm$) and octopus($17.9{\sim}18.4ppm$). In dried laver and sea mustard, however, amines were not detected at all. The levels of nitrate nitrogen in the dried marine samples ranged from zero to 16.8ppm and were high in the dried stingray(16.8ppm), alaska pollack(16.3ppm) and squid($2.2{\sim}12.4ppm$), but were less than 1.0 ppm in other samples. The levels of nitrite nitrogen were lower than those of nitrate nitrogen and it was not detected in dried sea cucumber, laver and sea mustard. Twenty eight of 31 samples contained NDMA($range=1.2{\sim}86.0ppb$), which was the only volatile N-nitroso compound found. The NDMA levels of dried stingray($2.8{\sim}86.0ppb$), alaska pollack($8.2{\sim}55.5ppb$), squid($3.3{\sim}53.2ppb$), yellow corvenia($45.9ppb$) and plain dried shrimp($15.4{\sim}17.9ppb$) were high. However, it was not detected in dried sea cucumber, laver and sea mustard. Samples, containing high levels of NDMA, also contained high nitrate and nitrite nitrogen. From above results, it can be concluded that nitrate and nitrite were major factors for the formation of NDMA in dried marine food products.

• Applied Biological Chemistry
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• v.45 no.3
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• pp.129-133
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• 2002

Suppression of nitrate accumulation in spinach and lettuce through foliar application of chitosan formula containing micronutrients is related with the increase of the nitrate reductase (NR) activity. If NR in spinach were highly expressed to increase the assimilatory activity, nitrate content could be reduced. For this, NR cDNA was cloned from the isolated mRNAs of spinach using reverse transcriptase-PCR. Nucleotide sequence of cloned spinach NR cDNA showed highly deduced amino acid sequence identity ($71{\sim}82%$) with other known plant NR genes. Only two nucleotide-base differences were observed in the cloned NR cDNA compared with that of the published spinach NR cDNA.

• Culinary science and hospitality research
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• v.10 no.2
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• pp.30-37
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• 2004

국내에서 유통되고 있는 수입어류 8종에 대한 발암성 물질인 N-nitrosamine콰 전구물질들의 함량을 분석하여 위생학적 기초자료를 제공하고자 하였다. 수입어류의 질산염 및 아질산염 함량은 각각 0.4∼12.8 mg/kg 및 N.D∼l6.0 mg/kg 이었다. Dimethylamine 함량은 1.0∼70.6 mg/100g 이었으며, Trimethylarnine 함량은 15.4∼70.6 mg/100g이었다. 수입어류 8종에 대한 발암성 물질인 N-nitrosamine은 N-nitrosodimethylamine (NDMA) 만 검출되었으며, 이들의 NDMA 함량은 2.1∼102.2mg/kg으로 러시아산 가자미에서 가장 높게 검출되었다. 또한 아르헨티나산 냉동새우는 35.3 $\mu\textrm{g}$/kg, 러시아산 냉동대구에서도 30.6 $\mu\textrm{g}$/kg으로 높은 함량을 보였다.

• Journal of Wetlands Research
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• v.12 no.2
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• pp.59-65
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• 2010

Wetlands are a well known ecosystem which have high spatial-temporal heterogeneity of chemical characteristics. This high heterogeneity induces diverse biogeochemical processes, such as aerobic decomposition, denitrification, and plant productivity in wetlands. Understanding the dynamics of dissolved organic carbon (DOC) and inorganic nitrogen in wetlands is important because DOC and inorganic nitrogen are main factors controlling biological processes in wetlands. In this study, we assessed spatial distribution of DOC and inorganic nitrogen with relation to the different hydrology and vegetation in created wetlands. Both DOC and nitrate contents were significantly higher in vegetated areas than open areas. Different water levels also affected DOC contents and their quality. Average DOC contents were $0.37mg{\cdot}g^{-1}$ in deep riparian (DR) and $0.31mg{\cdot}g^{-1}$ in shallow riparian (SR). These results appeared to be related to the interaction between carbon supply by vegetation and microbial decomposition. On the other hand, inorganic nitrogen contents were not affected by water level differences. This result indicates that presence/absence of vegetation could be a more important factor than hydrology in the spatial dynamics of inorganic nitrogen. In conclusion, we observed that vegetation and hydrology differences induced spatial distribution of carbon and nitrogen which are directly related to biogeochemical processes in wetlands.

• Korean Journal of Organic Agriculture
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• v.7 no.1
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• pp.115-127
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• 1998

Under the visual judgement of consumers, to reduce nitrate intake through vegetables, this experimentation analyzed the content of nitrate, in heading leaf vegetables such as chinese cabbage(Brassica campestris L. ssp. perkinensis (Lour.) Rupr), cabbage(Brassica oleracea L. var. capitata) and lettuce(Lactuca sativa L.) by the leaf number. And the result is summarized as follows In the nitrate content change by the leaf number, the nitrate content is increased as it goes by from inner leaf to outer leaf and the nitrate content in leaf midrib is higher than that in leaf blade. In case of chinese cabbage, the nitrate content in the leaf midrib from the most inner leaf to the most outer leaf changed 40-3,177ppm and in the leaf blade it changed 40-2,887ppm. But the nitrate content in the leaf blade of cabbage from the most inner leaf to the most outer leaf changed 89~2,297ppm and in the leaf blade it changed 25~765ppm. In case of lettuce, the nitrate content change of the leaf midrib by the leaf position was 419~4,349ppm, and in the leaf blade it changed 260~2894ppm. It was conclude that the outer leaf of chinese cabbage, cabbage and lettuce should be removed to keep the lower nitrate intake by population before it is consumed.