• Journal of Magnetics
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• v.16 no.3
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• pp.318-321
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• 2011

A new Fe-based amorphous compound powder was prepared from Fe-Si-B amorphous powder by crushing amorphous ribbons as the first magnetic component and Fe-Cr-Mo metallic glassy powder by water atomization as the second magnetic component. Subsequently by adding organic and inorganic binders to the compound powder and cold pressing, the new Fe-based amorphous compound powder cores were fabricated. This new Fe-based amorphous compound powder cores combine the superior DC-Bias properties and the excellent core loss. The core loss of 500 kW/$m^3$ at $B_m$ = 0.1T and f = 100 kHz was obtained When the mass ratio of FeSiB/FeCrMo equals 3:2, and meanwhile the DC-bias properties of the new Fe-based amorphous compound powder cores just decreased by 10% compared with that of the FeSiB powder cores. In addition, with the increasing of the content of the FeCrMo metallic glassy powder, the core loss tends to decrease.

• Journal of the Korean Ceramic Society
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• v.37 no.9
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• pp.915-920
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• 2000

합성과 동시에 소결이 이루어지는 HPCS법을 이용하여 TiB$_2$-W 복합체를 텅스텐의 함량 변화에 다라 제조하여 이 복합체의 미세구조 및 기계적 물성에 대하여 연구하였다. 이 연구 결과, 텅스텐의 함량증가에 따라 삼성분 붕화 화합물인 TiWB$_2$의 상이 증가하였으며, 이 상의 증가에 따라 기계적 물성이 향상되었다. 60 MPa의 압력과 130$0^{\circ}C$, 3000 A에서 소결한 TiB$_2$-30vol% W 복합체에서 상대밀도, 강도, 경도 값은 각각 97.2%, 411.5 MPa, 22.36 GPa로 가장 우수한 물성을 얻을 수 있었다.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.511-512
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• 2010

• Proceedings of the Korean Magnestics Society Conference
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• 2011.12a
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• pp.144-145
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• 2011

• Korean Journal of Crystallography
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• v.12 no.3
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• pp.141-144
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• 2001

From the reaction of Na[Ga(N₃)₄] with PPh₃, an ionic compound [Ph₃P(OH)]/sup +/[N₃]/sup -/ (1) was isolated. Compound 1 was characterized by spectroscopy (¹H-NMR, /sup 13C{¹H}-NMR, and IR) and X-ray diffraction. Crystallographic data for 1 : orthorhombic space group P2₁2₁2₁, a = 10.491 (4) Å, b=11.603(5)Å, c=13.149(5)Å, Z=4, R(wR₂)=0.0547(0.0978).

• Korean Journal of Food Science and Technology
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• v.36 no.1
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• pp.19-24
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• 2004

Effect of polyphenolic compounds from green tea leaves and surfactant micelles on lipid oxidation in corn oil-in-water emulsion (O/W) wag determined. Concentrations of polyphenolic compound and surfactant in continuous phase of O/W were measured. Particle size of O/W with 17 mM Brij 700 and 5% corn oil increased with increasing concentration of polyphenolic compound (100-200 ppm). Concentration of surfactant in the continuous phase was lower than that of control. Lipid oxidation rates, as determined by the formation of lipid hydroperoxides and headspace hexanal, in O/W emulsions containing polyphenolic compounds decreased with increasing concentration of polyphenolic compounds (100-200 ppm). Inhibition of hydroperoxide and headspace hexanal produced via lipid oxidation by polyphenolic compounds in O/W was BHT>procyanidin B3-3-O-gallate>(+)-gallocatechin >(+)-catechin.

• Korean Journal of Materials Research
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• v.24 no.5
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• pp.249-254
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• 2014

Due to their unique properties, tungsten borides are good candidates for the industrial applications where certain features such as high hardness, chemical inertness, resistance to high temperatures, thermal shock and corrosion. In this study, conditions were investigated for producing tungsten boride powder from tungsten oxide($WO_3$) by self-propagating high-temperature synthesis (SHS) followed by HCl leaching techniques. In the first stage of the study, the exothermicity of the $WO_3$-Mg reaction was investigated by computer simulation. Based on the simulation experimental study was conducted and the SHS products consisting of borides and other compounds were obtained starting with different initial molar ratios of $WO_3$, Mg and $B_2O_3$. It was found that $WO_3$, Mg and $B_2O_3$ reaction system produced high combustion temperature and radical reaction so that diffusion between W and B was not properly occurred. Addition of NaCl and replacement of $B_2O_3$ with B successfully solved the diffusion problem. From the optimum condition tungsten boride($W_2B$ and WB) powders which has 0.1~0.9 um particle size were synthesized.

• Journal of the Korean Society for Heat Treatment
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• v.12 no.2
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• pp.136-144
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• 1999

The study on the wear characteristics of compound layers formed during gaseous nitrocarburising in the medium carbon boron steels and the plain carbon steel has been carried out by using a pin-on-disc type wear test machine under the oil lubricating condition at room temperature and by varying applied loads, sliding speeds and wear distances. Values of friction coefficient measured at the sliding speed of 0.4m/sec under the oil lubricating condition have been shown to decrease considerably with increasing applied load and become gradually a constant value as load is increased to a higher value, showing that the transition load for friction coefficient appears at an applied load of 247.2N. The length and volume wear rates of compound layer have been revealed to relatively constantly increase, also showing that the wear life per unit thickness of compound layer turns out to be superior as porous layer has a denser and thinner appearance. As the sliding speed increases during wear test performed by varying sliding speed at a load of 63.2N under the oil lubricating condition for medium carbon boron steel nitrocarburised in gas atmosphere, the wear rate has been found to increase, the friction coefficient to decrease and the wear life per unit thickness of compound layer to decrease considerably.

• Korean Journal of Crystallography
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• v.12 no.1
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• pp.10-13
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• 2001

Compound PdCl₂(PhCN)₂(1) reacted with tert-butylamine(t-BuNH₂) to give trans-[PdCl₂(t-BuNH₂)₂] (2) Compound 2 was characterized by spectroscopy (¹H-NMR, /sup 13/C{¹H}-NMR, and IR) and X-ray diffraction. Crystallographic data for f2: monoclinic space group p2₁/c, a=6.298(1)Å, b=20.740(2)Å, c=10.731(1)Å, β=92.58(1)°, Z=4, R(wR₂)=0.0207(0.0543).

• Journal of the Korean Magnetics Society
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• v.3 no.4
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• pp.284-288
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• 1993

Low temperature magnetic properties and crystal structures of melt-spun $Sm_{2}Co_{7}B_{3}$ compound were characterized. The magnetic measurements in the temperature range 77 K~450 K indicated that a spin-reorientation took place at about 150~160 K. A large anisotropy was observed(Ha=135 kOe at 300 K, 725 kOe at 77 K) for $Sm_{2}Co_{7}B_{3}$ although the magnetic moment is rather low. The crystal structure of the $Sm_{2}Co_{7}B_{3}$ compound was analyzed in detail by Rietveld analysis of powder diffraction pattern, and it was revealed that B(4h) atoms are not placed in the Sm(2e) layer but in between the Sm(2e) and Co($6i_{1}$) layers.