• Journal of the Korean Physical Society
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• v.73 no.11
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• pp.1703-1707
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• 2018

Ferromagnetic ${\tau}-phase$ $Mn_{54}Al_{46}C_{2.44}$ particles were synthesized, and its composites with commercial $Sm_2Fe_{17}N_3$ and synthesized $Fe_{65}Co_{35}$ powders were fabricated. Smaller grain size than the single domain size of the $Mn_{54}Al_{46}C_{2.44}$ without obvious grain boundaries and secondary phases is the origin for the low intrinsic coercivity. It was confirmed that the magnetic properties of the $Mn_{54}Al_{46}C_{2.44}$ can be enhanced by magnetic exchange coupling with the hard magnetic $Sm_2Fe_{17}N_3$ and soft magnetic $Fe_{65}Co_{35}$. The high degrees of the exchange coupling were verified by calculating first derivative curves. Thermo-magnetic stabilities of the composites from 100 to 400 K were measured and compared. It was demonstrated that the $Mn_{54}Al_{46}C_{2.44}$ based composites containing $Sm_2Fe_{17}N_3$ and $Fe_{65}Co_{35}$ could be promising candidates for future permanent magnetic materials with the proper control of purity, magnetic properties, etc.

• Journal of the East Asian Society of Dietary Life
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• v.19 no.1
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• pp.62-70
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• 2009

The principal objective of this study was to determine the optimal dilution magnification for Omi-Galsu. The pH of Omi-Galsu generated by varying the temperature of 200cc of water ($4^{\circ}C$ and $80^{\circ}C$) and quantity of Omi-Galsu concentrate (36 g, 45 g, 54 g) was $3.24{\sim}3.33$ and the sugar content of the solution was $6.60{\sim}9.50$, higher than the tea beverages on the market and slightly lower than fruit juice beverages. The Omi-Galsu had a caloric content of $30.65{\sim}38.70\;kcal$, and a protein content of $0.45{\sim}0.65%$. As a result of the sensory evaluations conducted during the summer season, it was determined that the Omi-Galsu produced by mixing 54 g of Omi-Galsu concentrate into 200cc water at $4^{\circ}C$ or $80^{\circ}C$ was the most preferred; however, during the winter months, the "gusto" of the Omi-Galsu produced by mixing 54g concentrate into 200cc water at $4^{\circ}C$ or 45 g of concentrate into 200cc water of $80^{\circ}C$ was preferred most strongly. All in all, the optimal dilution magnification for Omi-Galsu was found to be $4.7{\sim}5.4$.

• Parasites, Hosts and Diseases
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• v.35 no.1
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• pp.31-38
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• 1997

The skin ulcer in Leishmcnio mcior infection is known to be variable according to the inoculation sites even in a susceptible host. The present study traced the immunoblot patterns by the site of inoculation and duration of infection in BALB/c mice. L. mqior were subcutaneously inoculated on the nose, footpad, and back of the mice, in a dose of 3 × 106 promastigotes. Sera of the mice were collected every 10 days after inoculation. SDS-PAGE separated soluble protein bands of the promastigotes and immunoblot was carried out with the infection sera. The skin ulcer first appeared on the nose at 15 days, and on the footpad at 17 days after inoculation. The ulcer on the back appeared after 90 days. In the mice with ulcer on the nose or footpad, serum IgG antibody reacted to 202, 139, 98, 83, 81, 67, 65, 62, 59, 54, 52, 42, 26, and 23 kDa bands at 20 days after inoculation. In mice inoculated on the back, however, the immunoblot showed visible reactions with 202, 83, 81 74, 67, 65, 62, 59, 54, 52,20 and 17 kDa bands at 90 days after inoculation. The present result showed that the antigenic protein bands of L. mqior promastigotes were differed by the inoculation site and duration of infection. Since the skin ulcer and the serum antibodies to antigenic bands between 67-52 kDa appeared simultaneously, it is suggested that the serum IgG antibodies may play a role in formation of the skin ulcer in BALB/c mice.

• Journal of Magnetics
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• v.19 no.1
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• pp.55-58
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• 2014

We have synthesized ferromagnetic ${\tau}$-phase $Mn_{54}Al_{46}/{\alpha}$-phase $Fe_{65}Co_{35}$ composite by annealing a mixture of paramagnetic ${\varepsilon}$-phase $Mn_{54}Al_{46}$ and ferromagnetic ${\alpha}$-phase $Fe_{65}Co_{35}$ particles at $650^{\circ}C$. The volume fraction ($f_h$) of hard ${\tau}$-phase $Mn_{54}Al_{46}$ of the composite was varied from 0 to 1. During the annealing, magnetic phase transformation occurred from paramagnetic ${\varepsilon}$-phase to ferromagnetic ${\tau}$-phase $Mn_{54}Al_{46}$. The magnetization and coercivity of the composite monotonically decreased and increased, respectively, as the $f_h$ increased. These results are in good agreement with our proposed composition dependent coercivity and modified magnetization equations.

• Journal of the Korean Society for Heat Treatment
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• v.12 no.1
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• pp.55-65
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• 1999

Graphitization of cementite in high carbon steels at subcritical temperature is reported. We have studied about the effects of Ni in these steels on graphitization. The chemical compositions of the specimens were Fe-(0.54, 0.7)%-C-1.0%Si-0.1%Mn-(0.2~1.0)%Ni. After annealing at $650^{\circ}C$, $680^{\circ}C$ and $700^{\circ}C$ during various time the microstructures and hardness change were observed. In order to recover the initial hardness of high carbon steel, dissolution treatment of graphite was performed at $870^{\circ}C$. In case of 0.7%C steel, graphitization was accelerated rather 1.0%Ni addition steel than 0.2% and 0.54%Ni addition steels but the graphite is coarser. In case of 0.54%C-0.2%Ni steel, graphite particles were distributed relatively homogeniously and finely. Nickel addition promotes graphitization of these steels but makes graphite blocky.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.242-248
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• 2015

This study was performed to investigate the microbiological contamination on toothbrushes, toothbrush caps, and tooth cleaning cups in the child care centers and to evaluate the toxin genes, toxin production ability and antibiotic resistance of food-borne pathogens. The average number of total aerobic bacteria and fungi were 5.3 log CFU and 3.2 log CFU. Coliform bacteria were detected in 41 (54.7%) of 75 toothbrushes, 13 (44.8%) of 29 toothbrush caps, and 29 (44.6%) of 65 tooth cleaning cups. Salmonella spp. was not detected in all of samples but Bacillus cereus was isolated from 1 (1.3%) of 75 toothbrushes and 2 (3.1%) of 65 tooth cleaning cups. Staphylococcus aureus was detected in 1 (1.5%) of 65 tooth cleaning cups. The nheA, nheB, nheC, hblC, hblD, hblA and entFM toxin genes were possessed in B. cereus isolated from toothbrush which also produce NHE and HBL enterotoxins. S. aureus was resistant to ampicillin and penicillin, while B. cereus was resistant to ${\beta}-lactam$ antibiotics. These results indicated that the sanitary conditions of toothbrushes and tooth cleaning cups in the child care centers should be improved promptly. The UV sterilization after drying and then storage in dried condition is required to improve the sanitary condition of toothbrushes and tooth cleaning cups in the child care center.

• Journal of the Korean Institute of Gas
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• v.16 no.3
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• pp.54-64
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• 2012

DWTT (Drop Weigh Tearing Test) is one critical method that can exhibit the fracture properties of line pipe steel, since it estimates the properties with real pipe steel. In this study, the ductile portion, inverse fracture ratio and absorbed energy of API X65 and X70 line pipe steels were estimated with temperature variation. Both steels showed that the ratio of ductile area and absorbed energy were decreased with respect to decreasing the test temperature. However, while the ductile fracture behavior exhibited until $-40^{\circ}C$ for the X70 steel, but it showed until $-30^{\circ}C$ for the X65 steel. The fracture properties were discussed with respect to test temperatures.

• Journal of IKEEE
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• v.25 no.1
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• pp.15-24
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• 2021

In this paper, 1700 V EPDT (Extended P+ shielding floating gate Double Trench) MOSFET structure, which has a smaller switching time and loss than CDT (Conventional Double Trench) MOSFET, is proposed. The proposed EPDT MOSFET structure extended the P+ shielding area of the source trench in the CDT MOSFET structure and divided the gate into N+ and floating P- polysilicon gate. By comparing the two structures through Sentaurus TCAD simulation, the on-resistance was almost unchanged, but Crss (Gate-Drain Capacitance) decreased by 32.54 % and 65.5 %, when 0 V and 7 V was applied to the gate respectively. Therefore, the switching time and loss were reduced by 45 %, 32.6 % respectively, which shows that switching performance was greatly improved.

• Journal of applied mathematics & informatics
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• v.2 no.1
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• pp.17-24
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• 1995

In this paper we shall prove a new fuzzy continuous selec-tion theorem in a compact convex set and next a fixed point theorem for fuzzy mappings is established.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.5
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• pp.1087-1091
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• 1999

Microwave extraction system equipped with closed vessels, which is known to rapidly extract target compounds from natural products, was applied to monitor the changes in phenolic compounds, browning color intensity and electron donating ability by using response surface methodology(RSM). Maximum content of phenolic compound was 21.65mg/100ml in 67.88% of ethanol concentration, 145oC of extraction temperature, and 6.24min of extraction time. The phenolic compounds in extracts are dependent on the increase of the extraction temperature and the ethanol concentration. Browning color intensity, which was maximized in 67.21%, 147oC, and 6.02min, was proportional to the increase of the extraction temperature. Maximum value of electron donating ability was 24.50units in 54.33%, 147oC, and 6.11 min. The electron donating ability of extracts was dependent on the increase of extraction temperature and maximized in the range from 50 to 65% of ethanol concentration.