• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.6
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• pp.1071-1076
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• 1998

Threetypes of Korean traditional kimchi were prepared using green onion, leek or godulbaegi as raw materials and stored at 5oC and 20oC for 13 days. Changes in salt and ascorbic acid contents, pH and total acidity as well as the relationship of the decomposition of chlorophylls and the production of their derivatives were investigated. For the all kimchi samples tested, salt content was not significantly changed during storage at both temperatures, whereas pH and total acidity were decreased and increased, respectively. Especially their remarkable changes were shown at the third day of storage. Ascorbic acid content was remained at high level in the leek kimchi for the experimental period at both storage temperatures, meanwhile godulbaegi kimchi retained the least amount of ascorbic acid. Chlorophylls were decomposed to pheophytin and pheophorbide during storage at both storage temperatures, and this phenomenon was apparent at the third day of storage. Reduction of chlorophylls and increasements of its decomposed products such as pheophytin and pheophorbide were the least in leek kimchi and the greatest in godulbaegi kimchi during storage at both temperatures. These results indicate that decomposition of chlorophylls in kimchi and increasements of pheophytin and pheophorbide were closely related to the ascorbic acid content in kimchi.

• Journal of the Korean Society of Food Culture
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• v.27 no.6
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• pp.702-709
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• 2012

Seolleongtang, a traditional broth in Korea, is expected to become a hot global item for its unique flavor and healthiness. In this study, the correlations between sensory attributes and physicochemical characteristics were studied for the popular seolleongtang stock products through descriptive analysis, sensory evaluation and analysis of salt, soluble solid, protein, viscosity and color for the quality control. Our results indicate that color, concentration, viscosity, and freshness are important attributes in evaluating the quality of seolleongtang stock. There were significant differences between preference and sensory attributes among the stock products. Significant correlations were found between flavor and texture and overall acceptability, as well as beany odor and aroma. Preference and physicochemical aspects also correlated, and indicate that a range of salt, solubility, and viscosity are applicable as quality control factors in seollengtang stock.

• Journal of Surface Science and Engineering
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• v.25 no.6
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• pp.309-317
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• 1992

Evaluation of electroplated gold has been carried out to obtain the data base for electrical, mechanical and environmental properties for telecommunication component applications. Gold plating was performed to a various thickness of $0.1\mu\textrm{m}$ to 1.$25\mu\textrm{m}$ after Ni plating of $3\mu\textrm{m}$ on C52100 bronze. Electrical properties were evaluated by measuring contact resistance using 4-wire method under static contact and dynamic contact during wear. Reciprocating wear test was performed to study the wear behavior as well as failure of gold contacts. Environmental characteristics were evaluated by using salt spray testing and SO2 test. Hardness of soft gold film was measured to be 53KHN under 5g load. Friction coefficient was initially obtained to be 0.15 and 0.25 under 100g and 200g loads respectively, and then raised up to 0.8 with increasing reciprocating wear cycles. Static contact resistance was 2 to 3m$\Omega$ regardless of gold film thickness while drastic changes of contact resistance were occured upon stripping of the gold film during wear. The lifetime of contact wear showing stable contact resistance increased up to 6 times for $1\mu\textrm{m}$ thickness compared to that of$ 0.1\mu\textrm{m}$ thickness under 100g load. All gold plating appeared to be stable under salt atmosphere while only the gold plating over 1$\mu\textrm{m}$ was stable under SO2 atmosphere.

• Food Science and Preservation
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• v.7 no.2
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• pp.222-227
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• 2000

Antimutagenic activity of crushed kimchi fermented with starter under various conditions such as temperature(5-20$^{\circ}C$), salt concentration(2-10%), addition rate of starter (0-20%) was investigated. The kimchi was fermented with crushed Chinese cabbage without salting, red pepper powder, crushed garlic, crushed ginger, anchovy juice and starter. Well fermented kimchi juice(fermented at 10$^{\circ}C$ for 15 days) and sterilized radish juice was used as a source of lactic acid bacteria and starter medium, respectively. Antimutagenic activity showed the highest in the crushed kimchi fermented at 15$^{\circ}C$ for 15 days, 4% salt concentration, 5% starter added, respectively. The inhibition rate of mutagenic activity of the kimchi against S. typhimurium TA98 induced by NQO and S. typhimurium TA100 induced by MNNG was 56.41% and 60.11%, respectively. And the inhibition rate of the kimchi juice showed 56-60% per 100ul.

• KSBB Journal
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• v.29 no.3
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• pp.205-209
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• 2014

Chromatographic enantiomer resolution of chiral amines was performed on several covalently immobilized and coated chiral stationary phases (CSPs) based on polysaccharide derivatives under the mobile phase conditions containing base or acid or acid/base additive. The chromatographic parameters including separation factors and capacity factors were greatly influenced by the nature of the mobile phase containing base or acid or salt additive as well as the used CSPs. When 0.05% triethylamine/0.05% trifluoroacetic acid as an additive in the mobile phase was used on all CSPs in this study, the greatest enantiomer resolution was observed except for Chiralpak AD. Also, it was shown that the change of base additive into acid or salt in the mobile phase may directly affect chiral recognition mechanisms between the chiral selectors and analytes occurring during enantiomer separation, resulting in the change of elution orders.

• ALGAE
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• v.21 no.1
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• pp.133-139
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• 2006

Outdoor cultivation of cyanobacterium Spirulina platensis was carried out for 40 days in a batch mode. A half concentration of the SOT based on the underground water was used as culture medium. Working volume was 5.7 tons with 0.2 m depth. During cultivation, mean water temperature, DO and light intensity were all in proper conditions for the S. platensis growth. The adjustment of pH to over 10 with Na2CO3 and addition of the 1.5% natural salt were very effective to delete contaminant organisms, Chlamydomonas moewusii and Chlorella minutissima occurred one after the other in the culture. The mean productivity of the biomass based on the dry cell weight from 14 to 25 days, after the contaminants were deleted, was 7.8 g ·m–2· d–1, which was relatively high productivity in that a half concentration of the SOT was used for the culture. Underground water used in the culture minimized contaminants invasion and addition of the 1.5% natural salt was effective to delete contaminants as well as acted as mineral supplement in outdoor cultivation of S. platensis. Harvesting using the floating activity of S. platensis was effective from mass floating in day time after overnight without agitation and illumination.

• Journal of the East Asian Society of Dietary Life
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• v.25 no.1
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• pp.12-19
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• 2015

This study was performed for the purpose of establishing proper dietary behaviors and improving sodium intake status by investigating nutrition knowledge, dietary behaviors, and food intake frequency related to sodium in 398 university students living in Gyeonggi-do and Incheon. Female students showed a higher rate of eating out more than five times a week as well as daily snack intake than male students. Female students showed a higher score for sodium-related nutrition knowledge than male students, whereas male students showed higher sodium intake than female students. Subjects who showed a higher frequency of eating out and snack intake also showed a higher salt intake ratio and sodium-related nutrition knowledge. Subjects with higher scores related to sodium-related nutrition knowledge showed a higher low salt intake ratio and incidence of low sodium food intake. From this research, depending on the level of nutrition knowledge related to sodium university students showed differences in dietary behavior related to sodium intake. This result would be helpful to develop lower sodium training materials specific to low sodium food selection tips, reading nutrition labels, and so on.

• Journal of Surface Science and Engineering
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• v.24 no.1
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• pp.34-34
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• 1991

Corrosion behavior of TiN coated steel was studied in terms of thickness of interlayer Ti and TiN coating TiN was are ion plated to a thickness of 1$\mu\textrm{m}$ and 2$\mu\textrm{m}$ respectively with interlayer coating of Ti of 1$\mu\textrm{m}$, 2$\mu\textrm{m}$ and 3$\mu\textrm{m}$. Corrosion resistance of TiN coated steel was evaluated by anodic palarization test in 1N H2SO4 as well as salt spray test. Porosity of each coating was also tested by using SO2 test method. Corrosion current density decreased with increasing TiN coating thickness and Ti interlayer coating markedly enhanced the corrosion resistance. Ti interlayer coating of 2$\mu\textrm{m}$ and 3$\mu\textrm{m}$ prior to 2$\mu\textrm{m}$ TiN coating decreased the corrosion current density of active range by an order of 4 and that of passive range by an order of 2. This improvement was associated with the retardation of corrosive agent penetration with increasing coating thickness and inherent corrosion resistance of Ti interlayer. Ti interlayer coating was also very effective in improvement of corrosion resistance under salt atmosphere.

• Journal of Surface Science and Engineering
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• v.25 no.1
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• pp.34-39
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• 1992

Corrosion behavior of TiN coated steel was studied in terms of thickness of interlayer Ti and TiN coating. TiN was arc ion plated to a thickness of 1$\mu\textrm{m}$ and 2$\mu\textrm{m}$ respectively with interlayer coating of Ti of 1$\mu\textrm{m}$, $2\mu\textrm{m}$ and $3\mu\textrm{m}$. Corrosion resistance of TiN coated steel was evaluated by anodic palarization test in 1N $H_2$SO$_4$ as well as salt spray test. Porosity of each coating was also tested by using $SO_2$ test method. Corrosion current density decreased with increasing TiN coating thickness and Ti interlayer coating markedly enhanced the corrosion resistance. Ti interlayer coating of $2\mu\textrm{m}$ and $3\mu\textrm{m}$ prior to $2\mu\textrm{m}$ TiN coating decreased the corrosion current density of active range by an order of 4 and that of passive range by an order of 2. This improvement was associated with the retardation of corrosive agent penetration with increasing coating thickness and inherent corrosion resistance of Ti interlayer. Ti interlayer coating was also very effective in improvement of corrosion resistance under salt atmosphere.

• Journal of the Korean Applied Science and Technology
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• v.27 no.4
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• pp.545-551
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• 2010

Hydrophobically monoendcapped poly(sodium acrylate)s formed hydrophobic microdomains in water. This was concluded on poly(sodium acrylate)s with a linear $C_{12}$-alkyl chain attached specifically at the end of the polymer. There was no well defined CMC (critical micelle concentration), but rather a gradual transition from a micelle free solution to a micelle solution. Steady state fluorescence spectroscopy indicates that the micro domains are rather hydrophobic. At pH 5 in the abscence of salt and at pH 9 in the prescence of 1 M sodium citrate the CAC (critical aggregation concentration) was in the range of 0.1 to 2.4 mM. However at pH 5 there was a linear increase in the transition concentration with a head-group size due to an increase in steric and electrostatic repulsions between polymer main chains. At pH 9 in the abscence of salt the transition concentration was in the range of 1 to 80 mM. For the larger polymers there was a effect which consisted of a concentration gradient of sodium counterion toward the hydrophobic domain. The effect was larger for the larger polymers because of the higher total sodium concentration and the less steep counterion concentration gradient.