• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.11a
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• pp.153-162
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• 2005

In this Paper, sets of engineering analyses were conducted to renew the overall dimensions and configurations of a disposal container proposed as a prototype in the previous study. Such efforts and calculation results can provide new design variables such as the inner basket array type and thickness of the outer shell and the lid & bottom of a spent nuclear fuel disposal container. These efforts include radiation shielding and nuclear criticality analyses to check to see whether the dimensions of the container proposed from the mechanical structural analyses can provide a nuclear safety or not. According to the results of the structural analysis of a PWR disposal container by varying the diameter of the container insert, the Maximum Von Mises stress from the 102 cm container meets the safety factor of 2.0 for both extreme and normal load conditions. This container also satisfies the nuclear criticality and radiation safety limits. This decrease in the diameter results in a weight loss of a container by ${\~}$20 tons.

• Journal of the Earthquake Engineering Society of Korea
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• v.16 no.2
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• pp.47-60
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• 2012

Based on the Korean Building Standard Law, a building less than 3-stories and $1000m^2$ in area is defined as a small-level building and, as a result, this type of building has been excluded from the requirement to comply with seismic design. In order to prevent the loss of life and property under earthquake loadings, the small-scale building should satisfy the seismic performance specified in the current code through a seismic retrofit. In this study, a seismic retrofit scheme of a Buckling-Restrained Knee Brace (BRKB) was developed for non-seismic 2-story steel buildings, including small-scale buildings, using a fragility contour method. In order to develop an effective retrofit scheme of the BRKB for the building, a total of 75 BRKB analytical models were used to achieve the desired performance levels and analyzed using the fragility contour method. The seismic performance of the retrofitted building was evaluated in terms of the weight of the developed BRKB systems. This study shows that the fragility contour method can be used for rapid evaluation and is an effective tool for structural engineers.

• Journal of the Korean Society of Food Science and Nutrition
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• v.37 no.3
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• pp.309-316
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• 2008

This study was carried out to examine the effects of vitamin E on chronic gastric ulcer induced by alcohol treatment in rats. Chronic gastric ulcer model was established by oral administration of 70% ethanol at one time and supply of 15% ethanol for additional 7 days. Male Sprague-Dawley rats, approximately 200 g, were fasted for 24 hours and orally gavaged with 1 mL of 70% ethanol for the induction of acute ulcer. A supply of 15% ethanol dissolved in distilled water for 7 days were followed to maintain chronic gastric ulcer. Acute ulcer group was sacrificed at 3 hours after oral administration of 1 mL of 70% ethanol. Chronic groups were divided into three groups according to vitamin E levels; low-vitamin E (LVE, 0 mg/mL oil/day), normalvitamin E (NVE, 1 mg/mL oil/day) and high-vitamin E (HVE, 10 mg/mL oil/day). These groups were fed vitamin E free diets which were made of vitamin E free vitamin mix followed AIN-93M pattern for 7 days. Histological findings of congestion, hemorrhage and necrosis in gastric tissue were shown severely in acute ulcer group and LVE group of chronic ulcer groups. The concentration of gastrin in serum was significantly higher in LVE group. The content of histamine in stomach was lower in acute ulcer group but there was no significant difference among the chronic groups regardless of vitamin E levels. Content of malondialdehyde (MDA) in gastric tissue was higher in HVE group and activities of antioxidant enzyme, glutathione peroxidase (GPx) and catalase, were lower in HVE group. Myeloperoxidase (MPO) activities as a marker of neutrophils infiltration was significantly higher in LVE group. These results suggested that vitamin E supplementation has positive effects on healing of alcohol-induced chronic gastric ulcer through alleviation of gastric tissue injuries and reduction of the MPO activity in gastric tissue and gastrin in serum.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.25 no.6
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• pp.487-495
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• 2012

In order to prevent the high velocity bullet from penetration, aluminum alloy and RHA(Rolled Homogeneous Armour) steel, which have a high tensile and compressive strength, are usually used as the bullet-proof armor material. Although these materials have a good bullet proof performance, but not an area density which is a weight increasing factor of bullet-proof armor. Therefore, Mg(magnesium) alloy is a promising substitute for the traditional bullet-proof armor material due to the relatively low areal density. The spatial efficiency of Mg alloy, however, is inferior to the traditional material's, which is a volume(thickness) increasing factor of bullet-proof armor. In this study, we select the multi-layered hybrid armor which consist of Ceramic, with a high strength; Mg alloy, with a low areal density; Kevlar, with a high tensile strength-to-weight ratio; in order to make up for the poor spatial efficiency of Mg alloy. By predicting V50 of the multi-layered armor against 9mm FMJ(Full Metal Jarket). we show that the multi-layered armor have the capability in improving bullet-proof performance in the respect of the areal density, but also the spatial efficiency.

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.8
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• pp.1114-1120
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• 2015

; This study investigated the improvement effects of artificial rice containing Curcuma longa L. on lipid parameters in 3T3-L1 cells and C57BL/6J mice. Mice were divided into four groups, normal diet group (ND), high-fat diet group (HD), 20% artificial group (A20), and 20% Curcuma longa L. artificial rice group (C20), for 14 weeks. Adipogenesis was significantly suppressed compared with non-treated control at a concentration of $20{\mu}g/mL$. After the animal experiment, food efficiency ratio was elevated in the experimental group due to high-fat diet, whereas it was reduced in the A20 group and significantly reduced in the C20 group. Epididymal fat pad weight was significantly diminished in the C20 group. In addition, serum triglycerides were significantly reduced in the A20 and C20 groups compared to the HD group. Moreover, serum cholesterol level tended to decrease in the A20 group and significantly decreased in the C20 group compared with the HD group. According to these results, we can know that Curcuma longa L.-containing artificial rice has an improvement effect on lipid metabolism.

• Composites Research
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• v.30 no.2
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• pp.158-164
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• 2017

The fiber metal laminate is a type of hybrid materials laminated thin metallic sheets with fiber reinforced plastic sheets. The laminate has been researched or applied in automotive and aerospace industries due to their outstanding impact absorbing performance in view of light weight aspect. Specially, the replacement of side-impact beam as the fiber reinforced plastic has been researched actively. The objective of this paper is the primitive investigation in the development of side-door impact beam using the fiber metal laminate. First, the three-point bending simulations were conducted to decide the shape of impact beam using the numerical analysis. Next, two cases impact beam (pure DP 980 and fiber metal laminate) were installed in the side-door, and then the bending tests (according to FMVSS 214S) were simulated using the numerical analysis. It is noted that the side-door impact beam can be replaced with the fiber metal laminate sufficiently based on the numerical analysis results.

• Journal of Korean Society of Environmental Engineers
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• v.27 no.11
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• pp.1146-1152
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• 2005

Graft copolymers were synthesized from methylcellulose(MC) and acrylic acid(AA) with active carboxyl groups in the presence of potassium persulfate($K_2S_2O_8$) initiator to enhance adsorption capacity of toxic heavy metal such as $Pb^{2+}$ and $Cu^{2+}$ from wastewater. The resulting grafted copolymers(MC-g-AA/PAA) were mixture of the graft copolymers from MC and AA(MC-g-AA) and polyacrylic acid homopolymers(PAA). The degree of palling was increased with rising concentration of monomer and initiator under the reaction conditions at $60^{\circ}C$, 3 hrs. The water insoluble property of MC-g-AA showed more than 19.7% degree of grafting. So that it could be an adsorbent of heavy metals. Adsorption characteristics of the MC-g-AA were evaluated depending on the degree of grading, pH of wastewater, adsorption time, dosage of MC-g-AA and concentration of heavy metals in the different conditions. Degree of grafting, and initial concentration of heavy metal ions increased, the adsorption amount of $Pb^{2+}$ and $Cu^{2+}$ increased, but added MC-g-AA increased, the adsorption amount per unit weight of $Pb^{2+}$ and $Cu^{2+}$ decreased. The MC-g-AA showed the high $Pb^{2+}$ and $Cu^{2+}$ adsorption amount in the range pH $4{\sim}6$. Also all of $Pb^{2+}$ and $Cu^{2+}$ ions reached in adsorption equilibrium in neighborhood 4 hours. The adsorption of heavy metals described by Freundlich isotherm, it was determined the value of l/n of $Pb^{2+}$ and $Cu^{2+}$ that 0.4294 and 0.3453, respectively.

• Journal of Nutrition and Health
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• v.51 no.3
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• pp.201-207
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• 2018

Purpose: Obesity, a worldwide epidemic, is associated with insulin resistance, hyperlipidemia, hypertension, cardiovascular disease, and certain cancers. Many strategies, including natural alternative anti-obesity agents, are used widely to prevent obesity. This study examined the effects of silkworm hemolymph on the weight control of C57BL/6N mice fed with a high-fat diet. Methods: The mice were divided into five groups: normal group (N), high-fat diet group (HFC), high-fat diet and silkworm hemolymph (at dose of 1 mL/kg BW (HFS-1), 5 mL/kg BW (HFS-5) and 10 mL/kg (HFS-10) for 12 weeks. Results: After 12 weeks treatment, the administration of silkworm hemolymph decreased the final body weight significantly along with a decrease in the weights of epididymal fat and total fat. The plasma LDL-cholesterol concentration was significantly lower in the HFS-1, HFS-5, and HFS-10 groups than in the HFC group. In addition, the leptin level of the HFS groups was significantly lower than those of the HFC group without a change in the plasma insulin concentration. Conclusion: These findings suggest that the silkworm hemolymph may have the potential to prevent obesity.

• Journal of the Korean GEO-environmental Society
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• v.10 no.1
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• pp.49-54
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• 2009

The seismic slope stability is most often evaluated by the pseudo-static limit analysis, in which the earthquake loading is simplified as static inertial loads acting in horizontal and/or vertical directions. The transient loading is represented by constant acceleration via the pseudostatic coefficients. The result of a pseudostatic analysis is governed by the selection of the value of the pseudostatic coefficient. However, selection of the value is very difficult and often done in an ad hoc manner without a sound physical reasoning. In addition, the maximum acceleration is commonly estimated from the design guideline, which cannot accurately estimate the dynamic response of a slope. There is a need to perform a 2D dynamic analysis to properly define the dynamic response characteristics. This paper develops a new hybrid pseudostatic method that links the modified one-dimensional seismic site response analysis and the pseudostatic algorithm. The modified site response analysis adjusts the density of the layers to simulate the change in mass and weight of the layers of the slope with depth. Multiple analyses were performed at various locations within the slope to estimate the change in seismic response of the slope. The calculated peak acceleration profiles with depth from the developed procedure were compared to those by the two-dimensional analyses. Comparisons show that the two methods result in remarkable match. The calculated profiles are used to perform pseudostatic analysis. The results show that use of peak or a fraction of acceleration at the surface can seriously underestimate or overestimate the factor of safety, and that the proposed procedure significantly enhances the reliability of a standard procedure.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.810-814
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• 2004

This research was conducted to evaluate the safety of the herbicide-resistant rice, a genetically modified organism (GMO) developed by the Rural Development Administration by exposing it to 12 months old Sprague-Dawley rats for 8 weeks. The composition of herbicide-resistant brown rice with/without heating treatment was compared with those of conventional Ilpum brown rice with/without heating treatment to assess composition equivalence. Compositional analysis was performed to measure proximates, fiber, and minerals. The nutritional components of herbicide-resistant rice were similar to those of the nontransgenic control or were within the normal range of nontransgenic rice. Four groups of experimental male rats were fed one of the following diets for eight weeks: Ilpum brown rice (I) and its heated rice (IH) as non-GMO, and herbicide-resistant brown rice (G) and its heated rice (GH) as GMO- We checked clinical symptoms (anorexia, salivation, diarrhea, polyuria, anuria, fecal change), food intake, and water consumption every day, change of body weight once a week, and serum biochemistry and organ weights after 8 weeks of experimental feeding We did not find any significant differences in the above-mentioned items. These results suggested that genetically modified herbicide-resistant rice was compositionally equivalent to conventional Ilpum rice, and nutritional characteristics and safety of herbicide-resistant rice in old male rats treated for 8 weeks were not different from those of Ilpum rice, non-GMO.