• Composites Research
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• v.29 no.3
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• pp.111-116
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• 2016

The tilting pad journal bearing for the turbo compressor application has a role to support high speed and heavy loading rotor. White metal has been widely used for the bearing material but the conventional bearing is immediately suspended and induces serious serious damage to the rotor under the unexpected oil cut situation or the insufficient oil film formation. The carbon fiber reinforced composite having high specific stiffness, specific strength and excellent tribological characteristics can solve these seizure problems. In this work, the study on the durability of high thermal resistance carbon fiber/epoxy composite tilting pad journal bearing under oil cut situation was conducted. The material properties of the composite materials including tensile, compressive and interlaminar properties were measured at room and high temperature of oil cut situation. To investigate the possibility of failure of composite tilting pad journal bearing under oil cut situation, the stress distribution of the composite bearing was analyzed via finite element analysis and the Tsai-Wu Failure index was calculated. To verify the failure analysis results, the oil cut tests for the composite tilting pad journal bearing were conducted using industrial test bench.

• The Journal of the Korean dental association
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• v.49 no.4
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• pp.203-210
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• 2011

The aims of this study were to evaluate the adequate thickness of opaque resins for situations such as an oral black cavity and discolored tooth structure, as well as the translucency of each opaque material at various thicknesses. Six opaque-shade composite resins (Z-350 OA3, Amelogen Universal A2O, Esthet-X A2O, Esthet-X A4O, Charmfil UO and Aelite Universal OA3) were prepared in metal molds with a hole of 8 mm in diameter and various thicknesses (0.5mm, 1.0mm, 1.5mm, 2.0mm, 2.5mm, 3.0 mm and 4.0mm). Four backgrounds (white tile, black tile, C4 shade porcelain and opaque resin itself) were used to determine the translucency parameter (between black and white backgrounds). and to mimic a black oral cavity (between black and opaque resin backgrounds) and a discolored tooth structure (between C4 and opaque resin backgrounds). Color measurements were made by a colorimeter to determine the CIELAB values of each specimen with each background and to calculate the translucency parameter and ${\Delta}E^*$ value difference among the specimens on the backgrounds. The translucency parameter and ${\Delta}E^*$ obtained between black and opaque resin backgrounds decreased in similar pattern as thickness increased. A C4 background was masked by resin thicknesses of 0.5-1.0mm, while a black background required thicknesses of 1.0-2.0mm. Adequate knowledge about differences in the optical character like translucency of the materials used is essential, together with the accumulated experience of the individual clinician.

• Journal of the Korean Society of Costume
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• v.34
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• pp.195-208
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• 1997

1) The color of JOGORI and CHIMA was such gorgeous and those garments were put on during the events of GAM-EUNG-CHUNG-BAI HO-GU-GEO-RI JO-SANG-GEO-RI DEWT-JUN and CHAN-BOO-GEO-RI. 2)BULSA-JANG-SAM(JE-SUK-GEO-RI) was white colored and had wide sleeves putting on a pink priestrobe and a pink belt on it 3) they put on HONG-CHUL-NIK(GU-REUNG) and CHONG-CHUL-NIK(DAE-GEO-RI). 4)They put on GOO-GUN-BOK(JUN-RIP JUN-BOK(BYUL-SUNG-GEO-RI) DONG-DA-RI(Expel the demon) 5) MONG-DOO-RI(MAN-SIN-MAL-BYUNG) put on the garment constructed with the color and from of a white straight collar a wide sleeve and a pink belt 6) A long robe was colored with green (GAM-EUNG-CHUNG-BAI) and was used not as a headdress but as a man's overcoat. 7) CHANG-EUI was a green colored small CHAHG-EUI(SUNG-JO-GEO-RI). As observed above the Shaman apprel during Chosun Dynasty is a part of the traditional clothing originated from THE THEORY OF THE COSMIC DUAL FORCES and THEORY OF THE COSMIC DUAL FORCES and the FIVE ELEMENTS (i.e. metal wood water fire and earth) It's basic form and wearing method were not so different from the traditional clothing silmilar to the official uniform during Chosun Dynasty and the official uniform was the symbol of authority(almost almighty) at that time of period and to that the Shaman apparel was constructed with the more gorgeous colors to emphasize the sanctity or the descent of the Divine Being from heaven. We realized that a Shaman had put on the symbolic garment suitable for the grade and nature of the Divine Body at every events to enter into " The World of Gods"Gods."

• Journal of the Korean Society of Costume
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• v.61 no.9
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• pp.84-96
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• 2011

This paper investigates the formative features and the historical meaning of the Korean dress collection held in the Museum of Archaeology and Anthropology in Cambridge. The Museum holds a total of eleven items of koran dresses that were donated by two anthropologists in the first half of the twentieth century. Male dresses consist of a white cotton jacket (Jeogori), a under-vest (Deungbaeja) made of light wisteria rings, a headband (Manggeon) made of horsehair, a broad brimmed top hat (Gat) made of black horsehair gauze, an oilskin cover (Galmo) drawn over the hat in wet weather, and a hemispherical hat box (Gatjib). Female dresses comprise a pink silk jacket (Jeogori), a blue silk skirt (Chima) with pleats, a pair of woman's white cotton trousers (Sokgot), a black silk cap (Jobawi) decorated with pink tassels and imitation pearls, and a pair of green and magenta silk shoes (Danghye) with leather soles and metal rivets. Theses Korean dresses show what the western anthropologists had interests in. When collectors collect the folk objects, they thought much of the specificity of shape and material, the esthetic appreciation, and the representation of daily life. In terms of the value as the historical materials in the history of Korean dress, the under-vest of wisteria, the hat box, and the female dresses are worth paying attention to. The under-vest is one that was produced in earlier time among the remaining under-vests. The hat box represents that the hat belonged to the merchant classes. The female dress items show daily dresses worn by women of higher classes of the society in the 1920s.

• Journal of Ginseng Research
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• v.34 no.2
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• pp.132-137
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• 2010

Lead (Pb) is a metal that is generally considered to be toxic to the cardiovascular system. Pb-exposed animals display the evidence of increased oxidative stress and hypertension. The current study was designed to examine whether Korean red ginseng (KRG) has protective effects against Pb-induced hypertension and oxidative stress in Pb-exposed rats. Male Sprague-Dawley rats were randomly assigned to Pb exposure or control groups. KRG was administered in drinking water at a concentration of 100 mg/kg/day; the control group received plain drinking water. Animals in the Pb-exposed groups were provided with drinking water containing 100 ppm Pb acetate for 12 weeks. Blood pressure, plasma glutathione, blood Pb concentration, and hematologic data, such as red blood cell quantity, were determined. Pb poisoning was assessed by measuring the blood Pb concentration. Pb exposure (100 ppm) for 12 weeks resulted in a marked rise in systolic blood pressure and blood Pb concentration, as well as a significant reduction in plasma glutathione levels and red blood cell quantity. Other measurements, such as heart rate, body weight, and white blood cell quantity, were unchanged. Treatment with KRG significantly lowered blood pressure, raised plasma glutathione and increased red blood cell numbers in Pb-exposed animals; it also had no effect on heart rate, body weight, or white blood cell quantity. However, the elevated blood Pb concentration was not reduced by treatment with KRG (100 mg/kg). Taken together, these data indicate that treatment with KRG in Pb-exposed animals can reduce oxidative stress and lower blood pressure, suggesting that KRG might be protective against Pb-exposed hypertension and oxidative stress.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.04a
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• pp.181-184
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• 2003

GaN계 청색 여기용 광원으로 최적인 $Y_{3}AI_{5}O_{12}:Ce$계 phosphor를 고상반응으로 제조하여 white LED용 yellow 형광체로 신뢰성을 검토하였다. 출발시료는 metal hydrous oxide로 합성한 분말에 활성제로서 $Ce^{3+}$ 이온의 농도를 변화시키면서 로내의 온도와 시간을 변수로 하여 형광체를 제조하였다. 그 결과 $1650^{\circ}C$에서 2시간 소성시킨 분말의 경우, 입자 크기가 $3{\mu}m$이하인 순수 YAG 형광체를 얻을 수 있었으며 $Ce^{3+}$이온농도를 변화시킨 결과 0.03~0.05mol% 일 때가 가장 우수하여 해외제품수준을 능가하는 우수한 발광특성을 나타내었다. 이때 CIE1931 색좌표 값은 x=0.385, y=0.433으로서 green yellow 색을 나타내었다.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.849-856
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• 2012

Chip on board type white light emitting diode on metal core printed circuit board with high thixotropy silicone is fabricated by vacuum printing encapsulation system. Encapsulant is chosen by taking into account experimental results from differential scanning calorimeter, shearing strength, and optical transmittance. We have observed that radiant flux and package efficacy are increased from 336 mW to 450 mW and from 11.9 lm/W to 36.2 lm/W as single dome diameter is varied from 2.2 mm to 2.8 mm, respectively. Double encapsulation structure with 2.8 mm of dome diameter shows further significant enhancement of radiant flux and package efficacy to 667 mW and 52.4 lm/W, which are 417 mW and 34.8 lm/W at single encapsulation structure, respectively.

• Journal of Welding and Joining
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• v.18 no.2
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• pp.86-94
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• 2000

This study was performed to investigate types and formation mechanism of cracks in two Al alloy welds, A5083 and A7N01 spot-welded by pulse Nd : YAG laser, using SEM, EPMA and Micro-XRD. In the weld zone, three types of crack were observed : center line crack({TEX}$C_{C}${/TEX}), diagonal crack({TEX}$C_{D}${/TEX}), and U shape crack({TEX}$C_{U}${/TEX}). Also, HAZ crack({TEX}$C_{H}${/TEX}) was observed in the HAZ region, furthermore, mixing crack({TEX}$C_{M}${/TEX}) consisting of diagonal crack and HAZ crack was observed. White film was formed at th hot crack region in the fractured surface after it was immersed to 10% NaOH water. In the case of A5083 alloy, white films in {TEX}$C_{C}${/TEX} crack and {TEX}$C_{D}${/TEX} crack region were composed of low melting phases, {TEX}$Fe_{2}SiAl_{8}${/TEX} and eutectic phases, $Mg_2$Al$_3$ and $Mg_2$Si. Such films observed $CuAl_2$, {TEX}$Mg_{32}(Al,Zn)_{3}${/TEX}, MgZn$_2$, $Al_2$CuMg and $Mg_2$Si were observed in the whitely etched films near {TEX}$C_{C}${/TEX} crack and {TEX}$C_{D}${/TEX} crack regions. The formation of liquid films was due to the segregation of Mg, Si, Fe in the case of A5083 alloy and Zn, Mg, Cu, Sim in the case of A7N01 alloy, respectively. The {TEX}$C_{C}${/TEX} and {TEX}$C_{D}${/TEX} cracks were regarded as a result of the occurrence of tensile strain during the welding process. The formation of {TEX}$C_{M}${/TEX} crack is likely to be due to the presence of liquid film at the grain boundary near the fusion line in the base metal as well as in the weld fusion zone during solidification. The {TEX}$C_{U}${/TEX} crack is considered a result of the collapsed keyhole through incomplete closure during rapid solidification.

• The Journal of Art Theory & Practice
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• no.3
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• pp.9-34
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• 2005

Contemporary Korean art in the 1960s and the 1970s reflects the social and political contexts in Korea from the 5 16 revolution through the Yoo Shin period. This paper investigates whether art has been free from power or not. It examines the power embedded in contemporary Korean art in the 1960s and the 1970s. This paper examines the historical moments of the Korean Art Exhibition, focusing on the complications between the abstract and figurative artworks of the 1960s. One of the significant art exhibitions since the 8 15 liberation of Korea, the Korean Art Exhibition witnessed conflict among Korean artists who wanted to have power in the art world of Korea. Institutional contradiction based on factionalism and conservatism prevailed in the Korean Art Exhibition was attacked by the avant-garde young artists in the 1960s. With the contact of Abstract Expressionism, young artists' generation participated in the The Wall Exhibition. This exhibition challenged and established moral principles and visualized individual expression and creation similar to the Informal movement in the West. In the world of the traditional painting of Korea, the Mook Lim Exhibition of 1960, organized by young artists of traditional painting, advocated the modernization of Soo Mook paintings. Additionally, abstract sculptures in metal engraving were the new trends in the Korean Art Exhibition. In the 1970s, the economic development and establishment of a dictatorial government made the society stiffen. Abstract expression died out and monochrome painting was the most influential in the 1970s. After the exhibition of Five Korean Artists, Five White Colors in the Tokyo Central Art Museum in 1976, monochrome paintings were formally discussed in Korea. 'Flatness' 'physicality of material' 'action' 'post-image' 'post-subjectivity' and 'oriental spirituality' were the critical terms in mentioning the monochrome paintings of the 1970s. 'Korean beauty' was discussed, focusing on the beauty of white which was addressed by not only Yanagi Muneyoshi but also the policy of national rehabilitation under the Yoo Shin government. At this time, the monochrome paintings of the 1970s in Korea, addressing art for art's sake, cutting of communication with the masses, and elitism, came to be authorized.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.196-208
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• 1998

To improve the quality of environmental measurements and evaluation of the workplace air in the pigment manufacturing industries, we analyzed metal(chromium, cadmium, lead, iron, cobalt, manganese, antimony, titanium, arsenic, and selenium) concentrations by ICP-AES in sixty seven samples of inorganic bulk pigments which are produced and/or used in Korea. We also collected MSDS which has to be supplied by manufacturer and/or supplier and posted in the workplace according to the Hazard Communication Standards, and compared the number of metals listed in each MSDS with the number of metals determined by ICP-AES. Results were as followed; 1. Among seventeen yellowish-colored samples, chromium(2~19%) and lead(0.1~61%) were the two major metals. In thirteen reddish-colored samples, iron was the major component with 37~81%. Cobalt and manganese were detected in blue-colored samples with less than 1%, while antimony and titanium were the major two metals in white-colored pigments with 178~300 ppm and with 36~65%, respectively. 2. In area samples collected in workplace air(one pigments producing factory and five retailer stores), iron and manganese were detected but the concentrations not exceeded the TLVs(1 and $5mg/m^3$, respectively). In three of fifteen samples, the concentrations of lead exceeded the TLV ($0.05mg/m^3$). 3. Two out of seven companies provided MSDS, and the average provision rate was 22.4%. And the coincidence rate of the number of metals referenced in MSDS and determined by ICP-AES mostly accorded, but in one sample, different metal was detected from MSDS. In summary, metals have to be concerned in evaluation of the workplace air dealing with compounds of inorganic pigments dust are cobalt, chromium, iron, manganese, lead and antimony, and these are simultaneously determined by ICP-AES. Taking this opportunity, it is needed to reinforce that the personnel is to be concerned about prevention of workers' ill health regarding to provision of MSDS.