• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1123-1127
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• 2010

We report a simple and quick route for the preparation of high-quality, nearly monodisperse $Bi_2Te_3$, $Sb_2Te_3$, and $Bi_xSb_{2-x}-Te_3$ nanocrystallites. The reactions of bismuth acetate or antimony acetate with Te in oleic acid result in pure phase of $Bi_2Te_3$ or $Sb_2Te_3$ nanoparticles, respectively. Also, ternary $Bi_xSb_{2-x}Te_3$ nanoparticles were successfully synthesized using the same method. The size and morphology of the nanoparticles were controlled by varying the stabilizing agents. The as-prepared nanoparticles are characterized by X-ray diffraction, scanning electron microscope, and high-resolution transmission electron microscope using an energy dispersive spectroscopy.

• Journal of Magnetics
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• 제21권3호
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• pp.315-321
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• 2016

M-Zn (M = Sb, V, Nb) substituted M-type strontium hexaferrites were prepared by a ceramic method. The phase composition, morphology and magnetic properties were studied by x-ray diffractometry, scanning electron microscopy and vibrating sample magnetometry. Saturation magnetization increases with a substitution up to 75.0 emu/g (2.5 % higher compared to unsubstituted hexaferrite) and then decreases with a further substitution. A coercive field of substituted hexaferrite powders with highest saturation magnetization is more than 3 kOe. Substituted strontium hexaferrite powders prepared in this work are a rare example of high $M_S$ compositions without doping rare-earth elements and would be a promising candidate for a permanent magnet application.

• Tribology and Lubricants
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• 제26권4호
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• pp.246-253
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• 2010

Friction characteristics of the brake friction materials without environmentally regulated ingredients were examined to find their role in the brake performance. Five friction materials were produced based on a nearcommercial formulation by changing the relative amount of potentially hazardous ingredients to health and environment, such as $Sb_2S_3$, potassium titanate, and brass fiber. Tribological properties of the friction materials were obtained using a scale dynamometer and Krauss type tribometer. Results showed that the excluded three ingredients played important synergetic effects on tribological properties in terms of fade resistance, wear resistance and friction effectiveness. In particular, brass fibers played important roles in the friction stability by providing excellent thermal diffusivity at the friction interface. Potassium titanate whiskers showed excellent fade resistance and wear resistance compared to the substituted barite. Antimony trisulfide, on the other hand, showed little effect on the high temperature fade resistance and wear resistance, while it increased friction effectiveness at moderate temperatures. The friction materials without the three ingredients showed severe fade, indicating antisynergy effects.

• 한국전기전자재료학회논문지
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• 제24권2호
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• pp.156-161
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• 2011

The present study introduces a novel wet etching technique for nanostructure fabrications which usually requires low surface roughness. Using the current method, acquired profiles were smooth even in the nanoscale, which cannot be easily achieved with conventional wet or dry etching methods. As one of the most popular single crystal silicon etchant, potassium hydroxide (KOH) solution was used as a base solvent and two additives, antimony trioxide (Sb2O3) and ethyl alcohol were employed in. Four experimental parameters, concentrations of KOH, Sb2O3, and ethyl alcohol and temperature were optimized at 60 wt.%, 0.003 wt.%, 10 v/v%, and $23^{\circ}C$, respectively. Effects of additives in KOH solution were investigated on the profiles in both (110) and (111) planes of single crystal silicon wafer. The preliminary results show that additives play a critical role to decrease etch rate significantly down to ~2 nm/min resulting in smooth side wall profiles on (111) plane and enhanced surface roughness.

• 한국응용과학기술학회지
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• 제30권3호
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• pp.451-460
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• 2013

NOx from the thermal power plants are NO and $NO_2$. This work investigated the chemical/physical characteristics and SCR efficiency of newly prepared catalysts including tungsten ($WO_3$), molybdenum ($MoO_3$) and antimony ($SbO_3$) based on vanadia($V_2O_5$) over titania($TiO_2$). As a result of the examination, the surface area of the catalysts promoted with additional metals was larger and the de-NOx efficiency also was enhanced with temperature. The most efficient catalytst was $V_2O_5/TiO_2-WO_3$(10%) at $200^{\circ}C$. Such a high efficiency could contribute to reduce the ammonia slip.

• 한국주조공학회지
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• 제32권2호
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• pp.91-97
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• 2012

The effects of Bi and Sb additions on the microstructures and casting properties in lead-free Cu-Zn-Sn broze were investigated. (1) When only Bi was added to the bronze, Bi was precipitated on the ${\delta}$ phase of ${\alpha}$ dendrite cell boundary. When Bi and Sb were added together, Bi was precipitated on the ${\delta}_A$ which was the Sb-rich area in the ${\delta}$ phase. (2) The addition of Sb accelerated the formation of ${\delta}$ phase, and when Sb, Bi and Pb were added, Bi and Pb were precipitated as mixed solution in the ${\delta}_A$ phase. (3) The combined addition of Sb and Bi resulted in the suppression of shrinkage due to the complementary effects of the mass feeding of ${\alpha}$-dendrite cluster covered with ${\delta}$ phase and sealing of micro-shrinkage in the ${\delta}$ phase by solidification expansion of Bi.

• Journal of Microbiology and Biotechnology
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• 제12권1호
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• pp.31-38
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• 2002

Bacteria have evolved various types of resistance mechanism to toxic heavy metals, such as arsenic and antimony. An arsenical and antimonial resistant bacterium was isolated from a shallow creek draining a coal-mining area near Taebaek City, in Kangwon-Do, Korea. The isolated bacterium was identified and named as Pseudomonas sp. KM20 after biochemical and physiological studies were conducted. A plasmid was identified and its function was studied. Original cells harboring the plasmid were able to grow in the presence of 15 mM sodium arsenite, while the plasmid-cured (plasmidless) strain was sensitive to as little as 0.5 mM sodium arsenate. These results indicated that the plasmid of Pseudomonas sp. KM20 does indeed encode the arsenic resistance determinant. In growth experiments, prior exposure to 0.1 mM arsenate allowed immediate growth when they were challenged with 5 mM arsenate, 5 mM arsenite, or 0.1 mM antimonite. These results suggested that the arsenate, arsenite, and antimonite resistance determinants of Pseudomonas sp. KM20 plasmid were indeed inducible. When induced, plasmid-bearing resistance cells showed a decreased accumulation $of\;73^As$ and showed an enhanced efflux $of\;^73As$. These results suggested that plasmid encoded a transport system that extruded the toxic metalloids, resulting in the lowering of the intracellular concentration of toxic oxyanion. In a Southern blot study, hybridization with an E. coli R773 arsA-specific probe strongly suggested the absence of an arsA cistron in the plasmid-associated arsenical and antimonial resistance determinant of Pseudomonas sp. KM20.

• The Korean Journal of Ceramics
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• 제2권1호
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• pp.1-10
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• 1996

Transparent conducting $SnO_2$-based thin films have been coated on float substrates such as fused quartz, and ceramic fiber cloths such as the Nexel and E-glass cloth from tin alkoxides by the sol-gel technique. Also, thin films of alternating layers of $SnO_2$ and $SiO_2$ have been fabricated by dip coating. The sheet resistance and average visible transmittance of the films were investigated in the aspect of the applications as transparent electrodes such as liquid crystal displays, photo-detectors and solar cells. The Nextel and E-glass cloths coated with antimony-doped tin oxide (ATO) had sheet resistance of as low as $20 \;ohm/{\Box}$ and $120ohm/\;{\Box}$, respectively. The promotion effects of additives as $La_2O_3$ and Pt on the ethanol gas sensing properties of the films were investigated in the aspects of the applications as an alcohol sensor and a breath alcohol checker. Possible evidence of quantum well effects in the oxide multilayers of $SnO_2$ and $SiO_2$ was investigated.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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• pp.307-310
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• 2000

Antimony doped tin oxide (ATO) thin films were deposited at room temperature by ion-beam sputter deposition (IBSD) technique in oxidizing atmosphere utilizing Sb and Sn metal targets. Effect of Sb doping concentration, film thickness and heat treatment on electrical and optical properties was investigated. The thickness of as-deposited films was controlled approximately to $1500{\AA}$ or $2000{\AA}$, and Sb concentration to 10.8 and 14.9 wt%, as determined by SEM and XPS analyses. Heat treatment was performed at the temperature from $400^{\circ}C$ to $600^{\circ}C$ in flowing $O_2$ or forming gas. The resulting ATO films showed widely changing electrical resistivity and optical transmittance values in the visible spectrum depending on the composition, thickness and firing condition.

• 한국의상디자인학회지
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• 제7권1호
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• pp.77-84
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• 2005

The purpose of this study is to know on the changes characteristics of eye brow forms of the wester women. A facial image which people recognize contents on changes of image according to various eye brow changes on the face. Various changes of image were seen by length, angle and thickness of eye brow types. The ancient Egyptians used antimony powder to blacken their brows huge black lines. In medieval times, women shaved both their eye brows and their hairlines to give a pure look. The early nineteenth century, brows were untweezed and natural. In the 1920s, when women started paying attention to their faces and their freedom, brows were tweezed, narrowed. In the 1930s, the idealized faces of Jean Harlow, Marlene Dietrich and Greta Garbo - narrow tracery of drawn on brows. The eyebrows is filled various shape of the 1950s. In the 1970s, the Disco Decade of Dreadful tastes, women were at their tweezers again, manicuring their brows. Brooke Shields's natural-looking brow would be an example of the 1980s. In the 1990s, the eyebrow designed by superstar makeup artists who determined the look of fashion model and screen star.