• Journal of the Korean Magnetics Society
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• v.21 no.1
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• pp.10-14
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• 2011

We have measured the ferromagnetic resonance (FMR) signal in as deposited and $400^{\circ}C$ annealed CoFeB/MgO thin film to investigate the annealing effect on magnetic anisotropies and FMR linewidth (${\Delta}H_{PP}$). The uniaxial anisotropy field ($H_{K1}$) was only observed in the as deposited sample. Whereas, in the $400^{\circ}C$ annealed sample, the biaxial anisotropy field ($H_{K2}$) was additionally observed in accompany with uniaxial anisotropy field ($H_{K1}$). The appearance of biaxial anisotropy fields was originated from the crystalline growth of bcc CoFeB(001) from the MgO(001) interface and by the B diffusion during thermal annealing. Also, the ${\Delta}H_{PP}$ of $400^{\circ}C$ annealed sample was increased compared with that of as deposited sample, which was due to the broad distribution of the magnetization axis by the biaxial anisotropy.

• Journal of the Korean Magnetics Society
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• v.23 no.5
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• pp.154-158
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• 2013

We have analyzed the magnetization curves measures by using VSM and MOKE in synthetic antiferromagnetic coupled CoB/Ru/CoB thin film. The measured results were compared with calculated ones by Stoner-Wohlfarth model based on the magnetization behavior of two ferromagnetic layers ($M_1$, $M_2$). The calculated total magnetization ($M_{tot}=M_1+M_2$) and single layer magnetization($M_1$) behaviors were compared with measured results by using VSM and MOKE, respectively. The total magnetization curve ($M_{tot}=M_1+M_2$) showed reversible magnetization behavior with flopping field of about 50 Oe. While single layer magnetization ($M_1$) behaviors showed irreversible magnetization behavior in the field range of $H_F$ < H < $H_F$. These magnetization behaviors were explained by the angle difference between magnetization directions of two ferromagnetic layers in SAF sample.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.5
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• pp.765-769
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• 2001

Starches of flavored glutinous rice were analyzed by using scanning electron microscope (SEM) and differential scanning calorimetry (DSC) and tested on the starch granule susceptibility to 15% H$_2$SO$_4$, glucoamylase and $\alpha$-amylase. The shape of starch granules form flavored glutinous rice varieties was polygonal and the size was 4~6 $\mu$m in diameter. According to DSC, glutinous rice starch showed onset temperature (T$_{o}$) range 59.8~62.5$^{\circ}C$ and KR92021-B-B-42-3-B and KR92021-B-B-165-1-B showed higher enthalpy ($\Delta$H) on gelatinization than others. The starches from KR92021-B-B-5-2-B and KR92021-B-B-42-3-B showed lower hydrolysis rate using 15% H$_2$SO$_4$ than KR92021-B-B-165-1-B. KR92021-B-B-5-2-B showed higher degree of hydrolysis of glucoamylase and $\alpha$-amylase than the others.

• Journal of the Korean Magnetics Society
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• v.21 no.3
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• pp.83-87
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• 2011

We have analyzed the torque signals measured in synthetic antiferromagnetic (SAF) coupled CoFeB/Ru/CoFeB thin film, which signals were drastically changed at flopping field ($H_F$) and saturation field ($H_s$). The minimum value of negative uniaxial anisotropy constant ($-\;K_1$) was appeared at HF. The $-\;K_1$ was due to the zero net magnetization by the antiferromagnetic coupling between two ferromagnetic layers. Whereas, the biaxial anisotropy constant (K2) was induced in the field range of $H_F$ < H < $H_s$. The induced $K_2$ was originated from deviation angles between magnetization directions of two ferromagnetic layers. And at H > $H_s$, intrinsic uniaxial anisotropy constant of CoFeB layer was observed. These change of the anisotropy constant with magnetic field was explained by the magnetization process of two ferromagnetic layers based on Stoner-Wohlfarth model calculation for SAF thin film.

• Journal of the Korean Magnetics Society
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• v.7 no.6
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• pp.327-333
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• 1997

We designed and constructed the high frequency magnetic characteristics measurement system to measure core loss, B-H curve, permeability of toroidal ferrite core, amorphous core and various materials for high frequency application. The system consists of universal equipments such as digitizing oscilloscope, signal generator, power amplifier, PC in order to make upgrade easily. The power source is composed of waveform synthesizer and power amplifier ranging from DC to 20 MHz, and output signal H and B from sample core are digitized by oscilloscope with sampling rate 1 GS/ s per channel. Computer controls power source and oscilloscope, reads data from oscilloscope, displays analyzed waveform and saves data with file. The entire procedures finishes within few seconds.

• KSBB Journal
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• v.19 no.4
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• pp.250-256
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• 2004

In this work we have cultivated several B. cereus strains in a complex LB medium in order to study the production of phospholipase C (PLC), and among them B. cereus 318 showed the highest productivity of PLC. Some components, i.e., 5 g/L glucose, 5 g/L yeast extract, 5 g/L peptone, 0.5∼1.0 g/L K$_2$HPO$_4$, 0.02∼0.04 g/L ZnSO$_4$$.$7H$_2$O and 3 g/L NaHCO$_3$ were found to be optimal for the high production of PLC by B. cereus 318. Optimal culture temperature and pH were found to be 30$^{\circ}C$ and pH 7.5 for the PLC production, respectively. Optimum reaction temperature and pH of the PLC produced by B. cereus 11 and 318 were 45$^{\circ}C$ and pH 4.0, while they were 50$^{\circ}C$ and pH 7.0 for the PLC by B. cereus 559. The PLC produced by B. cereus was activated by Mn$\^$2+/, Co$\^$2+/ and dimethyl sulfoxide (DMSO), but its activity was inhibited by Cu$\^$2+/ and partially by glycerol, isopropanol and sodium dodecyl sulfate (SDS).

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.243-247
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• 2015

The characteristics of the fluid force reduction of a square prism having a small triangular prism at the upstream side was investigated by measuring of lift and drag on the square prism The experimental parameters were the width ratios (H/B=0.2~0.6) of triangular prisms to the prism width and the gap ratios (G/B=0~3) between the square prism and the triangular prism. The drag reduction rate of the square prism was increased and then decreased with G/B in case of the same H/B, and was increased with H/B in case of the same G/B. The maximum drag reduction rate was represented by 78.5% at H/B=0.6 and G/B=1.5. The lift reduction rate of the square prism was hardly not affected by the width and gaps ratios, the average value was about 52.4%.

• Proceedings of the Korean Magnestics Society Conference
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• 2000.09a
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• pp.480-481
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• 2000

• Korean Journal of Food Science and Technology
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• v.20 no.1
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• pp.85-89
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• 1988

This work was carried out to get the basic data about packaged meat by investigating the characteristics of growth of B. thermosphacta. For this purpose. B. thermosphacta and Lactic acid bacteria were isolated from the vacuum-packaged beef and the effect of various conditions such as pH of beef, packaging method, and Lactobacilli on the growth of B. thermosphacta was investigated. In aerobic packaged beef, the pH did not affected the growth of the B. thermosphacta, while it did affected critically in vacuum packaged beef. The lowest pH for the growth of B. thermosphacta in aerobic-packaged beef was 5.3-5.4 and 5.4-5.5 in vacuum-packaged beef. The growth of B. thermosphacta was completely stopped when the beef with pH 5.7-6.0 was packaged in 100% $CO_2$, but it was not affected significantly when the beef was packaged in a mixture of $CO_2$(20%) and $N_2$(80% ). The inhibitory effect of lactic acid bacteria on the growth of B. thermosphacta was observed faintly in aerobic-packaged beef, but in vacuum-packaged beef, the lower the pH , the more significant its inhibitory effect. The growth of B. thermosphacta was almost stopped in a beef with pH 5.5-5.6.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.852-853
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• 2011

통상적으로 전기기기에 사용되는 전기강판의 자기특성은 B-H 자기특성 곡선을 이용하여 표현되어졌고, 이를 이용하여 전기기기의 자계 분포 해석 및 특성 해석이 이루어져 왔다. 그러나 실제로 전기기기의 전기강판은 인가 자계의 방향에 따라 자기특성이 다르게 나타나고, 자속밀도와 자계세기의 방향이 다르게 나타나는 벡터 자기특성을 가지기 때문에, B-H 곡선과 같은 스칼라 자기 특성으로 전기강판의 자기 특성을 정확히 표현하는 것이 불가능하다. 따라서 전기기기의 정확한 자계 해석 및 특성 해석을 위해서는 전기강판의 벡터 자기특성이 반드시 고려되어야 한다. 본 논문에서는 전기강판의 벡터 자기특성이 전기기기의 자계 분포 해석에 미치는 영향을 알아보고자 하며, 전기강판의 벡터 자기특성의 고려를 위해 ($B_m,\theta_B$)법을 이용하였으며 간단한 형태의 단상 변압기 모델에 유한요소 해석을 적용하였다.