• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.6
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• pp.289-294
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• 2010

Ni-YSZ (Yttria Stabilized Zirconia) composite powders for SOFC were fabricated by glycine nitrate process. $ZrO(NO_3)_2{\cdot}2H_2O$, $Y(NO_3)_3{\cdot}6H_2O$, $Ni(NO_3)_2{\cdot}6H_2O$ and glycine were chosen as the starting materials. The structural properties of the sintered Ni-YSZ cermets have been investigated with respect to the volume contents of Ni. A porous microstructure consisting of homogeneously distributed Ni and YSZ phases together with well-connected grains was observed. The sintered Ni-YSZ cermets showed a porous microstructure consists of homogeneously distributed Ni and YSZ phases and the grains were well-connected. It was found that the open porosity is sensitive to the volume content of Ni. The Ni-YSZ cermet containing 35 vol% Ni seems to be suitable for the electrode material of SOFC since it provides sufficient open porosity higher than 30%.

• Journal of Korean Society on Water Environment
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• v.18 no.2
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• pp.123-130
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• 2002

Bench scale experiments were carried out with two biological nutrient removal(BNR) units, A/O and $A^2O$ processes, to investigate the behavior of phosphorus in the system and to compare the characteristics of phosphorus removal in two BNR processes. To achieve this goal, COD/T-P and COD/TKN ratios of the influent was varied in the range of 23~64 and 5~24, respectively. In A/O process, influent COD/T-P ratio should be kept higher than 44mg/L to meet the final effluent T-P concentration lower than 1mg/L and in $A^2/O$ process, influent COD/T-P and COD/TKN ratios higher than 56 and 10, respectively, were required for good phosphorus release and uptake with no influence of nitrate nitrogen in return sludge. At this conditions, the rate of phosphorus release in the anaerobic basin should be kept higher than 0.1 kg S-P/kg MLVSS d In A/O process, the phosphorus content of anaerobic and aerobic sludges was increased as SRT of total system was becoming longer resulting in decreasing the difference of phosphorus content between two sludges while phosphorus release in anaerobic basin and phosphorus uptake in aerobic basin was not incident. In $A^2/O$ process, the phosphorus content of anaerobic and aerobic sludges were not increased with higher SRT of total system due to the relatively high nitrate concentration in return sludge. However, the difference of phosphorus content between anaerobic and aerobic sludges was incident when phosphorus release and uptake was observed.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.09a
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• pp.395-398
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• 2003

Geosynthetic Clay Liners(GCLs) have been widely used as hydraulic barrier in landfills and remediation projects of contaminated sites. The aim of this research is to modify GCLs for effective removal of contaminants. We perform the free swell test, hydraulic conductivity test, and contaminants (TCE, hexavalent chromium, and nitrate) removal test on the bentonite-ZVI mixture with various ZVI content. As the ZVI content increased, contaminants removal efficiencies and swell volume increased, and hydraulic conductivity decreased.

• 한국해양학회지
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• v.5 no.1
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• pp.30-36
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• 1970

The water quality of the laver bed at Yongwon Ri, Changwon Gun was investigated during the spring and neap tide in March 1970. The effect of tide on the contents of various chemical constituents was irregular and the variation ranges of the contents were narrow. The pH value during flood and ebb tide was a constant of 8.2. The chlorosity range varied from 19.15 to 19.33g/l, the difference of 0.18g/l being comparatively small for coastal waters. The nutrient salts contents varied irregulary with the change in tide, but nitrite and soluble iron were not detected. In local distribution, chlorosity and silicate- silicon contents were found to be more at Sts. 1, 2 and 3 in the eastern area than at Sts. 4, 5 and 6 in the western area, wheras nitrate and ammonia contents were found to be more at Sts. 4, 5 and 6. The nitrate content was especially high, being twice as much as that at Sts. 1, 2 and 3 in the eastern area. In the spring tide, chlorosity was found, on the average, to be as much as 0.06g/l higher than in the neap tide, but the contents of nutrient salts were higher in the neap tide, especially the nitrate content was twice as much. When compared with other selected local laver beds, i.e., the tidal flats of the Nackdong and Somjin rivers, and of Wan Do Gun, the chlorosity level was highest but the nutrient salts contents level was, in general, slightly lower and the variation ranges narrow in the laver bed at Yongwon ri. The nitrate content, in particular was one tenth smaller than the others.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.3
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• pp.312-317
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• 1985

Growth response and nutrients uptake of tobacco grown on mulched and non mulched plots were investigated during the growing period. 1. The whole growing time was about 25 days shorter and relative growth rate was faster in the mulched plot than in the non mulched plot. 2. Nitrate content of leaf in the latter stage of tobacco grown on the non mulched plot was more continuously increased compared with mulched plot. As a result in the latter stage of tobacco leaf nitrate form of nitrogen level was much higher on non mulched plot than on mulched plot. 3. Reducing sugar content in cured leaves of tobacco grown on the non mulched plot was lower that of the mulched plot. This difference in reducing sugar content was remarkable in the bottom leaves that nitrate content was highest. 4. Tobacco growing on nonmulched soil may cause to be low quality owing to increasing of nitrogen compound and decreasing of reducing sugar content in cured leaves. 5. As distributions of nitrate and potassium content in leaves at different stalk position was similar each other, nitrate and potassium ion considered to be counter ion in absorption and translocation through the tobacco plant.

• Journal of Food Hygiene and Safety
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• v.19 no.4
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• pp.203-208
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• 2004

The shells of Anadarac tegillarca granosa, Crassostrea gigas, Crassostrea nippona, and Patinopecten yessoensis were used for preparation of calcium carbonate with high purity. Calcium content in ash of shell was the highest $64.9\%$ in Anadarac tegillarca granosa ashed for 5 hr at $900^{\circ}C$, and followed as Patinopecten yessoensis $62.5\%$, Crassostrea gigas $62.4\%$, and Crassostrea nippona $61.5\%$. Whiteness of ash was the highest 81.6-85.8 in Patinopecten yessoensis shell. Calcium contents in calcium carbonates made with shells of Anadarac tegillarca granosa by using ammonium chloride process (ACP) and ammonium nitrate process (ANP) were higher $40.03-40.04\%$ than $39.92\%$ in Anadarac tegillarca granosa ash. Calcium content was the highest $40.04\%$ in pH adjusted calcium carbonate prepared by using ANP. Whiteness of calcium carbonate prepared by using ACP and ANP was the level of 101.0-101.5. Therefore, we estimated that the calcium carbonate made by using ACP and ANP could be used potentiality as a food additive for calcium supplement.

• The Korea Journal of Herbology
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• v.30 no.1
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• pp.19-24
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• 2015

Objectives : This study was carried out to know the necessity of freezing and boiling process of Gastrodiae Rhizoma. Also we need to evaluate Gastrodia elata floral axis as a product ingridients. Methods : Frozen Gastrodiae Rhizoma (GF1, GF2) and Gastrodia elata floral axis (GFA) were prepared. They were divided into samples (GF1 : frozen at the freezer, GF2; frozen and boiled for 10 hours, GFA; dried at 7 $0^{\circ}C$ for 120 hours) for experiment. They were extracted using water, freeze dried and powdered. And we analyzed proximate compositions, free sugars, gastrodin, p-hydroxybenzyl alcohol and p-hydroxybenzyl aldehyde content, phenolic and flavonoid, electron donating ability and nitrate scavenging activity and antioxidant activity. Results : In moisture, crude ash, fructose, glucose, sucrose, p-Hydroxybenzyl alcohol GF2 showed lower level than GF1. But GF2 showed higher content than GF1, in crude fat (0.8% > 0.19%), gastrodin ($8.84{\pm}0.58%$ > $4.18{\pm}0.73%$), and p-hydroxybenzyl aldehyde ($2.45{\pm}0.26%$ > $2.07{\pm}0.16%$) content, phenolic ($9.98{\pm}0.07%$ > $3.35{\pm}0.03%$) and flavonoid ($3.01{\pm}0.06%$ > $1.09{\pm}0.04%$) content, electro donating ability ($15.21{\pm}6.51%$ > $10.44{\pm}4.78%$), nitrate scavening activity ($20.43{\pm}5.30%$ > $13.62{\pm}5.78%$). GFA has a relatively lower key indicators component, but has a enough impact on antioxidant effect in phenolic ($11.85{\pm}0.08%$) and flavonoid content ($1.45{\pm}0.03%$), electron donating ability ($18.58{\pm}9.06%$) and nitrate scavenging activity ($19.41{\pm}9.90%$). Conclusions : In the view of proximate compositions, free sugars, functional component and antioxidant activity, the results indicated that boiling process is effective for the frozen Gastrodiae Rhizoma. And Gastrodia elata floral axis has a significantly functional components and antioxidant activity.

• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.254-262
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• 2005

This experiment was carried out to select the desirable welsh onion (Allium fistulosum L.) varieties for the year-round cultivation in water culture. Ten varieties were tested, of which five were Korean's and the other five were Japanese's. The germination percentage and germinative energy of most varieties we.e more than 90 percent. The fastest germination speed were 'Geumjanguedaepa', 'Gujopa' and 'Fuyune'. The best growth of the varieties were 'Geumjanguedaepa' and 'Tokyokuro' in spring, 'Geumjanguedaepa', 'Gujopa', 'Saesaeksisilpa' and 'Tokyokuro' in summer, 'Geumjanguedaepa', 'Gujopa' and 'Tokyokuro' in fall, and 'Geumjanguedaepa', 'Midorigawa' and 'Tokyokuro' in winter cultivation. Suitable varieties of growth fur all seasons were 'Geurnjanguedaepa' and 'Tokyokuro', though 'Gujopa' was good in summer and fall. In the view of nutritional content, nitrate content was significantly lower in 'Geumjanguedaepa', 'Tokyokuro' and 'Fuyune' than that in'Saesaeksisilpa' and 'Starziam'. Vitamin C content was higher in 'Aqua Green', 'Midorigawa' and 'Seoulbaekpa' than that of the others. Pyruvic acid content was the highest in 'Geumjanguedaepa' and 'Suckchanguedaepa'. Based on the above results, 'Geumjanguedaepa', 'Gujopa' and 'Tokyokuro' were selected as the most desirable young welsh onion varieties for the year-round water culture.

• Korean Journal of Environmental Agriculture
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• v.26 no.3
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• pp.223-227
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• 2007

This study was carried out to establish the reasonable level of nitrogen (N) fertilization based on soil nitrate nitrogen $(NO_3-N)$ content for cucumber (Cucumis sativus L.) under plastic film house. Cucumber plants were cultivated with standard and free N fertilization in eight soils which had various amount of $NO_3-N$ ranging from 67 to 343 mg/kg. The yield of cucumber was in the range of 1006 to 2369 g/plant depending on the nitrogen supplying capability of soils. The amount of $NO_3-N$ in the soil was negatively correlated with agronomic efficiency (AE) and N use efficiency (NUE). The critical level of soil $NO_3-N$ content for cucumber in N free fertilization was found to be about 260 mg/kg in Cate-Nelson analysis of variance between soil $NO_3-N$ and AE or NUE. Also the same critical soil $NO_3-N$ content was found in the yield and amount of N uptake of cucumber under N free fertilization. A standard N fertilization was required when soil $NO_3-N$ content was below 70 mg/kg. The optimal application rate of N fertilizer for cucumber in the soils containing $NO_3-N$ between 260-70 mg/kg could be recommended by the equation Y=-1.032X+269.2 (Y: N fertilization rate, kg/ha; X : soil $NO_3-N$ content mg/kg).

• Journal of Food Hygiene and Safety
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• v.12 no.4
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• pp.333-339
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• 1997

The effects of kind of vegetables and of the kind and amounts of fermented fish sauce on the formation of nitrosamine (NA) during kimchi fermentation were investigated. Kimchies made of Chinese cabbage, cucumber, and radish with fermented shrimp, anchovy and liquid sauces were fermented at 4$^{\circ}C$ for 6 weeks and the changes in the content of nitrate, nitrite, trimethylamine (TMA), dimethylamine (DMA) and NA were studied. Nitrate content in kimchies made of Chinese cabbage, cucumber, and radish increased at the initial period of fermentation, but it decreased at the later period. Nitrite was not detected at the later period of kimchi fermentation. Overall, there have not been great changes in the contents of nitrite and nitrate. However, there have been considrable changes in the contents of TMA and DMA as fermentation progressed. Only nitrosodimethylamine (NDMA) at the level of 0.5~10.3 $\mu\textrm{g}$/kg was formed in three kinds of kimchies. More NDMA was formed in radish and cucumber kimchies than in Chinese cabbage kimchi. The pH was lowered faster in radish and cucumber kimchies than in Chinese cabbage kimchi. More NDMA was formed in Chinese cabbage kimchi made with fermented shrimp sauce than those with anchovy or liquid sauces. Shrimp sauce contained higher amount of DAM than anchovy and liquid sauces. The contents of NDMA tended to increase as the amount of shrimp sauce increased. The kind and amount of fermented fish sauce used for kimchi preparation may be an important factor affecting the formation of NDMA.