• Korean Journal of Medicinal Crop Science
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• v.20 no.4
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• pp.251-258
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• 2012

The management and control of mineral nutrients is one of most important techniques to increase the productivity and the quality of Korean ginseng. The mineral nutrients are measured with different plant tissues and different growth stages of 2-year-old ginseng grown under hydroponic culture with two different temperatures. The content of N, P, Ca, and Mg were higher at low temperature in both leaves and roots than those at high temperature. However, the content of K was high in leaves at low temperature compared to that of high temperature, while it was not significantly different in roots. The uptake amounts of N and K was higher throughout the experimental period at low temperature in both leaves and roots than those at high temperature. However, the uptake amount of P was not clearly different between two different temperatures and among six different growth stages. The uptake amount of N, P, K was generally decreased in leaves from June to August, while it was increased in roots. The relationship between dry weight and mineral nutrients in leaves was appeared positive with N, K, Ca, and Mg, but negative P. In roots, N, K, Ca, and Mg were negative, showing that was positive with only P. Comparing the correlation coefficients among mineral nutrients in leaves, N and K were significantly positive correlation each other. P was significantly positive correlation with Na and Zn. In case of roots, N was highly significant positive correlation with K, Mg, and Mn, but P was negatively correlated with Ca, Cu, Na, Fe, and Zn.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.2
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• pp.187-194
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• 2009

The aim of this study was to investigate the physicochemical characteristics of native Korean Allium wakegi Araki samples, which were grown from seven local seed bulbs(Yesan, Muan, Anmyon-do, Deokjeok-do, Jeju-do, Yecheon, and China) to produce high quality native Korean Allium wakegi Araki. For the proximate composition of samples, moisture contents were in the range of 90.69~92.43%. The crude protein content of the Jeju-do sample was highest compared to the other samples. However, there were no significant differences in total sugar contents between samples. The seed bulb origin did not affect the hardness of the stem part, but was high for the leaves of the Yesan sample compared to the other samples. The results for anti-oxidative activity were as follows: Yesan(2.30 mg/mL) > China(2.51 mg/mL) > Muan (2.56 mg/mL) > Yecheon(2.74 mg/mL) > Jeju-do(2.85 mg/mL) > Anmyon-do(2.87 mg/mL) > Deokjeok-do(3.18 mg/mL). In terms of mineral and amino acid contents, the Yesan sample showed the highest levels, respectively, compared with the other samples. Food values such as contents of total phenolics and pyruvic acid were highest in the Jeju-do sample. These results show that the physicochemical characteristics of Allium wakegi Araki were significantly different according to different seed bulb origins.

• Korean Chemical Engineering Research
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• v.46 no.2
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• pp.330-339
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• 2008

Effect of additives such as NP series nonionic surfactant and cosurfactant on AgCl nanoparticles was investigated where nanoparticles were prepared using two different types of water-in-oil (W/O) microemulsions containing silver nitrate and sodium chloride, respectively. Phase behavior experiments showed that the region of one phase W/O microemulsion was found to be broadened with an increase in the ethylene oxide length of a nonionic surfactant mainly due to an increase in hydrophilic nature of a surfactant. Photomicrographs obtained by transmission electron microscopy indicated that an increase in ethylene oxide length of a nonionic surfactant results in both increases in particle size and size distribution. Phase behavior experiments for the systems containing AOT surfactant, isooctane and aqueous solution of an inorganic salt showed that addition of a cosurfactant caused a shrinkage in phase region of one phase W/O microemulsion, especially water contents contained in W/O microemulsion with an increase in the chain length or the concentration of a cosurfactant used. Photomicrographs obtained by transmission electron microscopy indicated that characteristics of AgCl nanoparticles produced were dependent both on the radius of spontaneous curvature and film rigidity of a microemulsion.

• Journal of Environmental Science International
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• v.15 no.1
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• pp.85-94
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• 2006

The simultaneous analysis of multi-residual pesticides was developed using a gas chromatography (GC) method. In this study, a simple and reliable methodology was improved to detect 154 kinds of pesticides in sinseng extract sample by using a liquid-liquid extraction procedure, open column chromagraphy and chromatographic analysis by CC electron capture detector (ECD) and GC nitrogen-phosphorus detector (NPD). The 154 kinds of pesticides were classified in 4 groups according to the chemical structure. The extraction of pesticides was experimented with $70\%$ acetone and dichloromethane/petroleum ether in order, and cleaned up via open column chromatography $(3\times30cm)$ packed with florisil $(30g,\;130^{\circ}C,\;12hrs)$. The final extract was concentrated in a rotator evaporator at $40^{\circ}C$ until dryness. Then the residue was redissolved to 2ml with acetone, and analyzed by GC-ECD and GC-NPD. The applied concentration of pesticides was over $1\~10{\mu}g/ml$. The recovery tests were ranged from $70.7\%$ to $115.2\%$ with standard deviations between 0.3 and $5.7\%$ of the standard spiked to the ginseng extract sample (Group $I\~IV$). The limit of detection (LOD) ranged from 0.001 to $0.099{\mu}g/ml$ (Group $I\~IV$). The 9 kinds of pesticides were not detected. The developed method was applied satisfactory to the determination of the 154 kinds of pesticides in the ginseng extract with good reproducibility and accuracy.

• Journal of Mushroom
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• v.13 no.3
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• pp.207-211
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• 2015

To investigate the usefulness of Kenaf(Hibiscus cannabinus L.) as mushroom culture media source, we analyze physical condition and contents of nutritional components. The water absorption rate of Kenaf bast was 578% and it was 95% higher than that of poplar sawdust's. This was caused by Kenaf's porous cellular structure. so it could give more moisture and oxygen to cultured mushroom. Total carbon contents of Kenaf was 91.4%, it was quite higher than that of poplar sawdust, wheat bran and rice bran. Total nitrogen content was 1.76% and C/N ratio was 51.9. The content of NFE(Nitrogen free extract) was 46.6% and it was similar with rice bran. Cellulose content was higher than poplar but lignin content was lower. specially hemicellulose and pectin complex which more digestible carbon source to mushroom was 3.7% higher than poplar. Mineral component and amino acid contents were also maintained high compared with poplar. Fe was 4.2 times, P 3.2 times, K 2.2 times more and Ca was higher 16 mg/kg than poplar. The content of amino acid was quite more higher than poplar sawdust but lower than chaff. Consequently Kenaf had a good trait for basic support material in mushroom culture media and also had a good character as nutritional source.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.1
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• pp.56-68
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• 2005

We measured nitrate and other nutrients in sediment pore waters retrieved from three sites at the southern upper-tidal flats of the Ganghwa Island. Denitrification rate is estimated by applying a simple 1-D model to the nitrate profiles. Results from Jangwha and Dongmak sites are $7.8{\sim}9.4{\times}10^{-7}{\mu}mol{\cdot}cm^{-2}{\cdot}sec^{-1}$, and $1.4{\sim}3.6{\times}10^{-7}{\mu}mol{\cdot}cm^{-2}{\cdot}sec^{-1}$, respectively. Rates are comparable to those reported around the world in an order of magnitude. Denitrification was lower in summer. The rates were about 1.5 times higher at site where the surface sediments consist of relatively coarser particles. This implies that particle size would control the reactant supply to the subsurface sediment. One may claim the denitrification as an evidence of the biogeochemical purification function of tidal flat. However, the purification seems not a general attribute of a tidal flat when whole system is scrutinized by a thermodynamic criterion. Currently the term 'tidal flat' is used when describing the diverse coastal wetlands such as salt marshes, sandy tidal flats and muddy tidal flats, which exhibit quite different ecological functions. Thus it is worthy of mentioning that the classification of coastal wetlands on the basis of sedimentological characteristics and biogeochemical functions should facilitate our understanding.

• Korean Journal of Food Science and Technology
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• v.24 no.6
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• pp.528-534
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• 1992

Growth stimulatory material for lactic acid bacteria was extracted from radish and radish green juice and its growth stimulatory effect was tested. Dried methanol-precipitated growth stimulatory material was lightly grayish white powder, Its ash content is 44% and approximately 50% of the ash is sulfur. It has reddish brown color upon solubilization in water. The material had unchanged stimulatory effect when it was treated with proteinase or pectinase, or ashed. The growth stimulatory activity was dialyzable. The material was able to counteract the growth inhibitory effect of EDTA. When selected lactic acid bacteria were grown at $30^{\circ}C$ for 24 hours in peptone(0.5%)-yeast extract(0.5%)-glucose(2%) broth with and without 0.5% growth stimulatory material, the material stimulated the growth of Lactobacillus plantarum, L. fermentum, L. leichmanii, L. sake, L. brevis, L. acidophilus, L. casei, Pediococcus pentosaceus, Leuconostoc mesenteroides, Streptococcus faecalis, S. lactis, S. cremoris and S. thermophilus by 19, 1833, 133, 444, 840, 32, 14, 18, 6, 17, 4, 5 and 4 times, respectively.

• Journal of the Korean Magnetics Society
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• v.3 no.2
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• pp.108-114
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• 1993

This paper presents a study on the effects of silica coating in the production of ${\gamma}-Fe_{2}O_{3}$ powders suitable for magnetic recording media. Emphasis has been put on investigating the relationship between the powder characteristics and the effects of silica coating in the heat-treatment stage of ${\gamma}-Fe_{2}O_{3}$ production. After we prepared non-coated ${\gamma}-Fe_{2}O_{3}$ and silica coated ${\gamma}-Fe_{2}O_{3}$ with coating water glass on the surface of goethite and heattreatment process, we compared and investigated powder characteristics. As silica coated layer played a role of preventing the powders from overreduction to metal iron and rapid oxidation, silica coated ${\gamma}-Fe_{2}O_{3}$ showed superior magnetization value due to inhibiting t!1e adulteration of ${\alpha}-Fe_{2}O_{3}$ into the final product. When silica coated layer acted as a sintering restrainer, silica coated ${\gamma}-Fe_{2}O_{3}$ showed high coercivity and specific sur-face area due to good acicularity.

• Journal of Ginseng Research
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• v.33 no.3
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• pp.234-239
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• 2009

This study aims to establish the directions for the optimal nutrient contents determined by soil and leaf analyses. The study is to be used as a source for basic information in investigating the effects of nutritional environment on ginseng growth at the fields of Ansung region in Gyeonggi province. The physical property of soil porosity is closely related to ginseng growth, with more than 50% of good growth in the field. The optimal range of chemical properties in soil was analyzed as 0.20-0.28% T-N, 500-900 mg/kg Av.P$_2$O$_5$, and 2.3-3.5 cmol$^+$/kg Exch.Ca. The optimal range of inorganic nutrient contents in leaves was also analyzed. P value was less than 0.25%, and Mg was more than 0.22%. Other elements were not found clearly. The ratios of N/P, N/Mg, K/Mg, and Ca/P of leaves with good growth in the field showed 10<, 10-13, <14, 1<, respectively. In addition, the Ca:Mg:K ratio of the Exch.cation (cmol$^+$/kg) may be useful as an indicator in the assessment of plant growth in ginseng.

• Food Science and Preservation
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• v.12 no.2
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• pp.123-129
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• 2005

This study was conducted to investigate the quality characteristics of functional 'sunsik' as the nutritionally balanced diet for the moderns. The major nutrient of nutritionally balanced 'sunsik' was carbohydrate, while contained lower contents of protein and lipid than general 'sunsik'. Sucrose was the major free sugar of nutritionally balanced 'sunsik', and major organic acids were malic, tartaric, oxalic and citric acid. Free amino acids were predominantly serine, arginine, alanine and glutamic acid. Linolenic acid $(12.52\%)$ was contained in the nutritionally balanced 'sunsik'. Ca, Mg, K, Na and Fe were found as major minerals. Antioxidant activity was about $29\%$ compared to BHA and BHT(200 ppm), and about $40\%$ of $\alpha-tocopherol$(400 ppm). Sensory evaluation of nutritional balanced 'sunsik' gained higher sensory score in color, cooked aroma, flavor, chewiness and overall acceptance, compared to the general 'sunsik'.