• Journal of the Korean Society for Geothermal and Hydrothermal Energy
• /
• v.12 no.3
• /
• pp.1-8
• /
• 2016

In this study, we evaluated the flow characteristics of various types of waveguide-below-cutoff (WBC) arrays and their shielding effectiveness (SE) of electromagnetic pulses (EMP) based on computational fluid dynamics (CFD). Three types of waveguides were selected for analysis: (1) grid type, (2) honeycomb type, and (3) multi-layer types (2-ply, 4-ply, 6-ply, and 8-ply). To analyze the air flow characteristics, the flow velocities in the longitudinal center of the WBC and the differential pressures between the WBC array inlet and outlet were evaluated. Consequently, we derive the following conclusions: (1) despite an increase in the inlet velocity, the pressure drop of the 6-ply multi-layer type did not significantly increase as compared to that of other types of waveguides (waveguide thickness of 0.1 mm, SE of 100 dB); (2) the grid and honeycomb type had the fastest flow rate of 17.5 m/s, which is approximately 2.5 m/s faster than that at the inlet (waveguide thickness of 1 mm, module size of 30 mm); and (3) the average pressure drop of the grid type waveguide is the lowest in the overall model, whereas that of the 8-ply is the highest (waveguide thickness of 1 mm, module size of 30 mm, and SE of 80, 100 dB).

• Journal of Environmental Health Sciences
• /
• v.45 no.2
• /
• pp.154-163
• /
• 2019

Objectives: The hazardous heavy metal contents of cosmetics were investigated and the resulting values were compared by type of cosmetics: skin care preparations (SCP), hair preparations (HP), makeup preparations (MP), and eye makeup preparations (EMP). Methods: The hazardous heavy metal contents (Pb, As, Cd, Sb, Ni and Hg) were analyzed for 358 cosmetics products (187 SCP, 82 HP, 56 MP, and 33 EMP). Hg was measured by the amalgamation method, and other hazardous heavy metals were measured by inductively coupled plasma optical emission spectrometer (ICP-OES) after decomposition using the microwave method. Results: The mean contents of Pb, As, Cd, Sb, Ni, and Hg in cosmetics were 0.424, 0.068, 0.024, 0.398, $0.567{\mu}/g$, and Not Detected, respectively. All of the hazardous heavy metals were detected in most products, but below the recommended maximums of the Ministry of Food and Drug Safety. The level of Cd was the lowest at 14.8%, and Sb was the highest at 41.2%. Pb, Sb and Ni showed the highest mean value and detection rate in EMP. As, Cd, and Hg showed the highest in SCP, HP, and MP, respectively. Conclusion: Hazardous heavy metals were detected in most products. In particular, Pb, Sb, and Ni were broadly detected in EMP, meaning more stringent quality control is required.

• Asian-Australasian Journal of Animal Sciences
• /
• v.20 no.9
• /
• pp.1402-1406
• /
• 2007

Thirty pregnant heifers (Jersey, Holstein Friesian and Hariana) were divided into three groups (10 animals/group) according to their stage of pregnancy viz. seven-month (181-210 days) pregnancy (SMP), eight-month (211-240 days) pregnancy (EMP) and nine-month (241-280 days) pregnancy (NMP) group. Time spent in various feeding activities (eating fodder, eating concentrate, standing rumination, sitting rumination and drinking) by each animal in the three pregnant groups was recorded in four different sessions (each session of 24 h per week). The time spent eating concentrate, eating fodder, standing rumination, sitting rumination and drinking was 61.4, 271.3, 84.6, 367.6 and 10.6 min/day, respectively in the SMP group; 52.7, 289.5, 103.3, 345.8 and 9.2 min/day, respectively in the EMP group and 65.0, 277.7, 138.1, 291.0 and 9.8 min/day, respectively in the NMP group. The animals in the EMP group spent significantly (p<0.01) more time on eating fodder and concentrate compared to the animals in SMP and NMP groups. The pregnant heifers preferred rumination in standing posture in comparison to sitting posture. The time spent on standing rumination was significantly higher in the NMP group whereas the time spent on sitting rumination was significantly lower in this group. Except for the sitting rumination activity, all the other activities were predominant in daytime compared to night time; the diurnal variation was significant (p<0.01) for all the activities.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.22 no.7
• /
• pp.584-588
• /
• 2009

Layered ZnS/$CaF_2$/ZnS/Cu film was deposited on glass substrate by using evaporation method. ZnS and $CaF_2$ were chosen as high and low refractive materials. Cu was used as mid-reflective layer. Reflectance with different optical thickness of $CaF_2$ ranging from $0.25{\lambda}\;to\;0.5{\lambda}$ were systematically investigated by using spectrophotometer. In order to expect the experimental results, the simulation program, the Essential Macleod Program(EMP) was adopted and compared with the experimental data. Based on the results taken by spectrophotometer, the ZnS/$CaF_2$/ZnS/Cu multi-layered thin film show the maximum reflectance of 80% at 625nm $(0.25{\lambda}\;in\;CaF_2)$ and 42% at 660nm $(0.5{\lambda}\;in\;CaF_2)$ respectively. As compared with the experimental results and simulation data, it was confirmed the experimental data is well matched with the EMP data.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2008.11a
• /
• pp.322-323
• /
• 2008

Multi layered thin films with ZnS/$Na_3AlF_6$/ZnS were deposited on glass substrate by thermal evaporator precess and simulated by using EMP(Essential Macleod Program). EMP is a comprehensive software package to design and analyse the optical characteristics of multi-layered thin film. ZnS and $Na_3AlF_6$ were selected as a high refractive index and low refractive index material respectively. Additionally Cu was chosen as mid reflective material. Optical properties including color effect were systematically studied. in terms of different optical thickness of low refractive index material. The optical thickness of $Na_3AlF_6$ was changed as 0.25, 0.5, 0.75 and $1.0\lambda$. The film with 0.25, 0.5, 0.75 and $1.0\lambda$. of optical thickness showed mixed color range between bluish green and red purple, yellowish green and bluish green, purple and mixed color range of green and purple respectively.

• Journal of Life Science
• /
• v.26 no.1
• /
• pp.59-67
• /
• 2016

Platycodon grandiflorum A. De Candolle (Korean name, ‘Doraji’) is a perennial plant containing various triterpenoid saponins. The roots of this plant have traditionally been used as a food material in Korea. Here, we prepared a fermented P. grandiflorum extract (PG). Although it was previously reported that P. grandiflorum A. extract has a variety of physiological functionalities, including anti-inflammatory and anti-oxidant activities, little is known about its vascular functions. In this study, we executed a series of experiments to identify the effect of PG on endothelial cells. PG at a high concentration (100 μg/ml) was found to induce cell detachment, whereas PG at a low concentration (0.1 μg/ml) appeared to promote cell proliferation and migration in bovine aortic endothelial cells. The cell detachment induced by the high concentration was not associated with cell death, such as apoptosis, necrosis, and autophagy. In addition, we found that PG at the high concentration formed a small vesicular structure called an endothelial microparticle (EMP). The EMP was prepared by centrifugal fractionation and determined with flow cytometry and a microscope. Interestingly, PG-induced cell detachment was found to be mediated by EMP. We furthermore determined that PG at the low concentration activated Akt, a crucial cell-signaling molecule, and then controlled cell proliferation and migration. Overall, our findings suggest that PG at low doses maintains vascular stability by promoting endothelial cell proliferation, and enhances the efficacy of wound healing by cell proliferation and migration activity.

• Journal of Periodontal and Implant Science
• /
• v.35 no.2
• /
• pp.345-357
• /
• 2005

Prostaglandin plays a significant role in the local control of bone metabolism associated with periodontal disease. ${\Delta}^{12}-PGJ_2$ is a natural $PGD_2$ metabolite that is formed in vivo in the presence of plasma. It is known for ${\Delta}^{12}-PGJ_2$ to stimulate calcification in osteoblastic cells. Bone morphogenetic protein(BMP) stimulated osteoblastic differentiation in various types of cells and greatly enhanced healing of bony defects. The purpose of this study was to evaluate the effect of rhEMP-2 on ${\Delta}^{12}-PGJ_2$ induced osteoblastic differentiation and mineralization in vitro. A human osteosarcoma cells line Saos-2 were cultured. In the test groups, 10-7M of ${\Delta}^{12}-PGJ_2$ or mixture of 10-8M of ${\Delta}^{12}-PGJ_2$ and 100ng/ml of rhBMP-2 or 100ng/ml of rhEMP-2 were added to culture media. After 1 day, 2 days and 4 days of culture period, the cell number was measured. Alkaline phosphatase activity was measure at 3 days. Reverse transcription polymerase chain reaction(RT-PCR) was performed to determine the expression of mRNA of bone matrix protein at 8 hours, 1 day and 7 days. The ability to produce mineralized nodules in rat osteoblasts(MC3T3-E1) was evaluated at 21 days. The results were as follows : 1. rhEMP-2 or mixture of rhBMP-2 and ${\Delta}^{12}-PGJ_2$ inhibited cell proliferation of human osteosarcoma cells. 2. rhEMP-2 or mixture of rhBMP-2 and ${\Delta}^{12}-PGJ_2$ stimulated alkaline phosphatase activity significantly higher than ${\Delta}^{12}-PGJ_2$ alone. 3. rhBMP-2 or mixture of rhEMP-2 and ${\Delta}^{12}-PGJ_2$ stimulated mineralization compared to ${\Delta}^{12}-PGJ_2$ alone. 4. mRNA of alkaline phosphatase, BMP-2, cbfa 1, Type I collagen were detected in the group treated with ${\Delta}^{12}-PGJ_2$/rhBMP-2, rhBMP-2 alone, ${\Delta}^{12}-PGJ_2$ alone. These results show that mixture of ${\Delta}^{12}-PGJ_2$ and rhBMP-2 causes more bone formation than ${\Delta}^{12}-PGJ_2$ alone while the bone formation effects of mixture of ${\Delta}^{12}-PGJ_2$ and rhBMP-2 are less than those of rhBMP-2 alone. Further researches would be necessary to clarify the interactions of these agents.

• The Monthly Technology and Standards
• /
• s.114
• /
• pp.15-15
• /
• 2011

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
• /
• v.25 no.3
• /
• pp.48-57
• /
• 2014

• Proceedings of the Korean Institute of Communication Sciences Conference
• /
• 1987.10a
• /
• pp.114-117
• /
• 1987