• Journal of the Korea Convergence Society
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• v.9 no.4
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• pp.75-84
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• 2018

This study investigated the pollution status of polycyclic aromatic hydrocarbons (PAHs) such as benzopyran, which is a harmful substance, in convergence herbal pills distributed in Seoul. During 2010 ~ 2013, 31 items and 93 samples were collected from the herbal medicines vendors in Seoul, and the samples were extracted, filtered, concentrated, and then spun out with SPE (Sep-pak florisil) and concentrated again and analyzed by liquid chromatography. The results of the analysis showed that the average contents of PAHs were below $10{\mu}g/kg$, and the PAHs were lower than those of daily life exposure, and MOEs was evaluated as safe to a negligible level. In the future, comparative fusion studies on the harmful substances of medicinal pills and food pills are needed.

• Journal of Nutrition and Health
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• v.37 no.1
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• pp.38-44
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• 2004

Food irradiation has been steadily increased in many countries concomitantly with increasing international trades and concerns about naturally occurring harmful contaminants of food. Although, irradiation provides an excellent safeguard for the consumer by destroying harmful bacteria, it would be necessary to investigate nutritional adequacy of irradiated foods with a special emphasis on such foods as red pepper powders, cold-water fishes (mackerel), sesame seeds that are widely consumed in Korea. These food items are of special concern due to the fact that most of them are imported and that several nutrients contained in them are sensitively reacting to irradiation. We observed changes in the antioxidant nutrients contents, such as vitamin A, $\beta$-carotene, vitamin C and total phenol, and also vitamin B$_1$ in the foods that were irradiated at different dose levels. The nutrients contents in red pepper were respectively 98.6% and 92.3％ for total phenol, and 97.8% and 94.5% for $\beta$-carotene, right after irradiation at the dose of 10 and 20 kGy. The vitamin C contents decreased with irradiation doses up to 76.4% (10 kGy) and 68.5% (20 kGy) and B$_1$ contents decreased to 54.9% and 80.7% of non irradiated red pepper. When the mackerel was irradiated at the applied dose of 3 and 7 kGy, total phenol concentration of the irradiated fish was respectively 91.3% and 94.2% of non irradiated fish. The amounts of vitamin A were 82.6% (3 kGy) and 78.0% (7 kGy) of unirradiated sample and vitamin B$_1$ contents reduced to 30.5% and 51.5%. $\alpha$-Tocopherol content was 33.9% of the non-irradiated one when it was irradiated at 7 kGy. Vitamin A and ${\gamma}$-tocopherol contents in sesame seeds linearly decreased with the applied doses (5 and 10 kGy) Vitamin A contents decreased up to 87.8% (5 kGy) and 82.9% (10 kGy) and that of ${\gamma}$-tocopherol were 72.4% and 66.5% of the unirradiated sample.

• The Korean Journal of Food And Nutrition
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• v.36 no.3
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• pp.193-201
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• 2023

Prebiotics are known as components of intestinal microbiota that can improve and maintain human health status by stimulating the growth and activity of the intestinal tract as a method of controlling the intestinal environment. In this study, we examined whether 2'-fucosyllactose (FL) could affect intestinal microbial population and bowel activity. Water content and frequency of mouse feces were increased in the 2'-FL treated group at a high concentration (1,000 mg/kg), with brightness of the color enhanced and physical properties diluted. In addition, intestinal microbial analysis showed that harmful bacteria Clostridium and Staphylococcus strains were decreased and beneficial bacteria such as Lactobacillus strains were markedly increased in the group treated with a high concentration of 2'-FL compared to those in the control group. These findings suggest that administration of 2'-FL can maintain healthy bowel activity by reducing harmful bacteria population and improving diluted physical properties.

• Journal of Korea Foundry Society
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• v.14 no.6
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• pp.520-529
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• 1994

This study describes the influence of the trace amount of sulphur on the nucleation behavior of graphite crystals in high purity Fe-C-Si alloys prepared by levitation melting method. Detailed microstructural analyses of high purity(HP) and sulphur added(HP＋S) samples showed that the nucleation of graphite crystals was prevented by sulphur. With decreasing the sulphur content, the shape of graphite crystals tended to spherulitic, and below 2ppm S, that of graphite crystals was only nodular. The critical cooling rate for the nucleation of griphite crystals was calculated as $1.5{\times}10^3k/s$. It is obvious from this work that residual C-C clusters act as an effective nucleation site for graphite crystals and one of the important role of nodularizing elements is to act as scavenger which removes harmful impurities from the solution.

• Journal of Welding and Joining
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• v.13 no.3
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• pp.125-133
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• 1995

Rene80 superalloy was liquid phase diffusion bonded by using pure boron (B) as an insert material. As a basic study for the possibility of practical application of this bonding method, hardness and high temperature tensile strength of the bonded joint and metallurgical analysis were investigated. As experimental results, hardness of the bonded joint was homogenized after bonding and the tensile strength at 1144K was obtained to 90% of that of base metal. But there were some problems to be improved also, that means the joint was hardened after bonding due to increase of B content and elongation was much lower than that of base metal. Flat area and (Mo, Cr, W) boride, which should be harmful for bonding strength, were observed on the fractured surface of the tensile tested specimen.

• Journal of Technologic Dentistry
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• v.23 no.1
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• pp.21-30
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• 2001

For biomedical applications. Ti-X%Zr-Y%Pd(X: $10{\sim}20$, Y:0.2 or 0.4) based alloys not containing harmful Al and V were newly designed, and polarization curves for their alloys were measured at $37^{\circ}C$ in 5% HCl solution in order to understand effects of Zr on the corrosion. From the results of anodic polarization behavior, it was found that the corrosion resistance increased with increasing Zr content. The results show their potential to develope Ti-based alloys for biomedical materials. The Ti-20%Zr-0.2%Pd alloy shows excellent corrosion resistance and was superior to those of the Ti. Ti-6%Al-4%V ELI alloy, Co-30%Cr-6%Mo alloy and STS 316L stainless steel.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.11a
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• pp.36-37
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• 2014

Construction work in island areas requires the materials to be transported by ship and plane, and it causes an increase in the construction costs. In addition, the construction work near marine zones may produce the marine pollution due to the harmful substances in the cement. Recently, nature-friendly construction materials are increasingly used, and there is a need to select and develop appropriate construction materials. In this study, the compressive strength, tensile strength, flow and chloride content of the mortar mixed with cement and muddy tidal flat were measured to reduce the amount of cement by applying the natural materials, muddy tidal flat and marine sand, and the results were provided as the basic construction material data.

• YAKHAK HOEJI
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• v.45 no.5
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• pp.448-454
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• 2001

The contents of heavy metals in boiled Sibjeonaebotang with those in its herbal ingredients are compared. The herbal medicines of Sibjeonaebotang were bought at 10 defferent markets. The contents of 14 heavy metals (Ag, As, Ba, Cd, Cr Cu, Fe, Hg, Mn, Ni, Pb, Sb, Sn, Zn) were analysed using ICP It was found out that 5 heavy metals (Pb, As, Ba, Fe, Sb) were detected in only one boiled Sibjeonaebotang But they were detectable in all Sibjeonaebotang and its herbal before boiling. For example the content of Hg in one pack of Sibjeonaebotang before boiling was 0.064$\pm$0.016 me and Hg in boiled one was 0.002$\pm$0.005mg. These results suggest that boiled Sibjeonaebotang which we take is less harmful than herbal medicine itself by heavy metals.

• The Korean Journal of Food And Nutrition
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• v.24 no.4
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• pp.817-832
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• 2011

It is said that the reason Bulgarians enjoy longevity is that they have a lot of yogurt, whose $Lactobacillus$ controls intestinal poison-producing germs. In young individuals, the number of bifidobacteria exceeds 10 billion per 1 g of intestinal content, but this number decreases for older or senile individuals, who have a larger number of harmful microorganisms such as $Clostridium$. In addition, it is well known that artificially increasing intestinal bifidobacteria can help control harmful microorganisms and thus facilitate a healthier and longer life. The microorganisms used for artificial spawn are referred to as probiotic microorganisms, and in general, lactic acid bacteria(LAB) are used. Unlike antibiotics, which kill harmful microorganisms, probiotic microorganisms coexist with and control them, while improving the health of the individual, that is, they can improve and invigorate host cells. Because probiotic microorganisms and its products based on LAB are known to help prevent and treat constipation, diarrhea, intestinal inflammation, and blood cholesterol and generally improve health through the purification of intestines, its market has been continuously expanding. Korea imports approximately 90% of spawn and uses them. It is likely that they are not appropriate for Korean's physical condition. Thus, considering this problem into account, Entecbio, a biotech firm in Korea, has produced various products by using its proprietary microorganisms. In this paper, the effects, characteristics, and kinds of products from based on proprietary microorganisms, with its prospect for market, etc., are generally examined.

• Korean Journal of Environmental Biology
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• v.18 no.4
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• pp.395-401
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• 2000

Growth and biochemical composition were analyzed in Gymnodinium sanguineum and Skeletonema costatum grown in media containing various nitrate and phosphate concentrations. Concentrations of nitrate and phosphate in the growth media were 0, 0.3, 0.6, 0.9, 1.2mM and 0, 15, 30, 45, 60 $\mu$M, respectively. Growth of G. sanguineum was suppressed in the low concentration of nitrate and phosphate (below N = 0.3 mM and P = 15 $\mu$M), whereas growth of S. costatum did not changed. At the low concentrations of nitrate and phosphate, amount of intracellular protein and carbohydrate in G. sanguineum cells were largely decreased, whereas content of carbohydrate in S. costatum cells was increased little. Amount of neutral lipid and phospholipid in G. sanguineum didn't changed, but concentration of glycolipid was largely decreased in the medium containing low concentrations of nitrate and phosphate. However the levels of TAG, glycolipid, and phospholipid did not changed in S. costatum cells. These results show that S. costatum is more adaptable than G. sanguineum in the low concentration of nitrate and phosphate.