• Title/Summary/Keyword: preferred temperature

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The Effects of Pulse Current on the Surface Appearance of Chromium Plating (크롬 전착층의 표면광택에 미치는 펄스도금의 영향)

  • 한성호;권식철;여운관
    • Journal of Surface Science and Engineering
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    • v.14 no.4
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    • pp.215-220
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    • 1981
  • The surface appearance of chromium electrodeposit was studied by employing a pulse curr-ent plating in self-regulating high speed (SRHS) bath containing 20 g/$\ell$, K2SiF6 7.5 g/$\ell$ SrSO4 and 250 g/$\ell$ CrO3. As the pulse frequency increased, the surface appearance changed suddenly from bright a-ppearance in a direct current plating condition to gray one in the range of pulse frequency less than about 20KHz. However the bright appearance is recovered as the pulse frequen-cy exceeded 20 KHz. This phenomena seemed to be related with the preferred orientation of electrodeposits, considering the relationship between the preferred orientation of elect-rodeposits and surface appearance in a SRHS bath. Direct current plating was also applied to both Sargent and SRHS bath and investigat-ion on surface appearance was extended to the high current density of 400 A/dm2. In a Sa-rgent bath, the increase in bath temperature was necessary for bright appearance as the current density was increased within 150 A/dm2, but bright region was shown in the cons-tant temperature of 70-75$^{\circ}C$ above the current density of 150A/dm2. On the other hand, two regions of surface brightness was found in a SRHS bath. One is region in the low temperature less than 25$^{\circ}C$ and the other in the moderate temperature range from 55$^{\circ}C$ to 65$^{\circ}C$.

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Color Temperature Conversion of Uncalibrated Video Signal Based on Color Compensation in POP-TV

  • Do, Hyun-Chul;Chien, Sung-Il;Tae, Heung-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.718-721
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    • 2003
  • It is often desirable that manufacturers and users can convert the reference white of display into the preferred color temperature by controlling the color temperature that is one of representative color characteristics of a light source. Accordingly, this paper proposes an efficient method of color compensation for displaying the uncalibrated video signal in PDP-TV and is also shown to be successfully coupled with flexible color temperature conversion based on the signal processing technique.

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Study on the Spheroidization of Cementite by Controlled-Rolling and Martensitic Nucleation and its Growth during Cooling in Ultra High Carbon Steel (초고탄소강의 제어압연에 의한 세멘타이트의 구상화와 냉각중 마르텐사이트의 핵발생과 성장의 현상론적 고찰)

  • Choi, C.S.;Yoon, J.K.
    • Journal of the Korean Society for Heat Treatment
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    • v.6 no.2
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    • pp.98-106
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    • 1993
  • Ultra high carbon steel (Fe-1.4%C) was prepared by means of a high frequency induction furnace. The preferred nucleation site of martensite was observed. The changes of hardness and impact thoughness due to tempering temperatures, and the spheroidization of cementite by controlled -rolling were also studied for the steel. The preferred nucleation site of martensite in the ultra high carbon steel is prior austenite grain boundary. The hardness of the steel is slightly increased up to about $300^{\circ}C$, and then decreased with further tempering temperature. However, the impact energy keeps a almost constant value, independent of the tempering temperature. The spheroidization of cementite is accelerated as the reduction in thickness per rolling pass is increased and the number of the rolling passes becomes greater.

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The Dyeability and Antibacterial Activity of Wool Fabric Dyed with Cochineal

  • Bae, Jung-Sook;Huh, Man-Woo
    • Textile Coloration and Finishing
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    • v.18 no.5 s.90
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    • pp.22-29
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    • 2006
  • The purpose of this study was to investigate the dyeability and antibacterial activity on wool fabric dyed with cochineal at variable dyeing conditions. Al, Cr, Fe, Cu and Sn were used as mordants and adsorption was compared with different mordanting methods. The optimum dyeing conditions of wool fabrics were dyeing concentration 2.0%(o.w.s), dyeing temperature $60^{\circ}C$, pH 3 and dyeing time 30 minutes. The pre-mordanting method was preferred for Al and Cr, and the post-mordanting one was preferred for Cu, Sn and Fe to achieve better dyeing. The optimum mordanting conditions of wool fabrics dyed with cochineal were mordanting concentration of 1%(o.w.s), mordanting temperature $60^{\circ}C$, and dyeing time 30 minutes. Wool fabrics dyed with cochineal showed a little antibacterial activity, but it was increased by Cu and Sn mordanting. The light fastness and perspiration fastness of wool fabric treated with cochineal were improved by mordanting.

Studies on Film Growth and Mechanical Properties of TiN by Chemical Vapor Deposition (화학증착에 의한 TiN 박막의 제조 및 기계적 성질에 관한 연구)

  • 김시범;김광호;천성순
    • Journal of the Korean Ceramic Society
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    • v.26 no.1
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    • pp.21-30
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    • 1989
  • Titanium Nitride (TiN) was deposited onto the SKH9 tool steels by chemical vapor deposition (CVD) using a gaseous mixture of TiCl4, N2, and H2. The effects of the deposition temperature and input gas composition on the deposition rate, microstructure, preferred orientation, microhardness and wear resistance of TiN deposits were studied. The experimental results showed that the TiN deposition is thermally activated process with an apparent activation energy of about 27Kcal/mole in the temperature range between 1200$^{\circ}$K and 1400$^{\circ}$K. As H2/N2 gas input ratio increased, the deposition rate increased, showed maximum at H2/N2 gas input ratio of 1.5 and then decreased. Mechanical properties such as microhardness and wear resistance have close relation with the microstructure and preferred orientation of TiN deposits. It is suggested that the equiaxed structure with random orientation increases the microhardness and wear resistance of TiN deposits.

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Schottky diode characteristics of a sol-gel driven ZnO (졸-겔 방법으로 제조한 ZnO 쇼트키 다이오드의 특성 연구)

  • Han, Kwang-Joon;Kang, Kwang-Sun;Kim, Jae-Hwan
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1733-1736
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    • 2008
  • ZnO thin films with preferred orientation along the (0 0 2) plane were fabricated by a sol-gel method. The effects of the annealing temperature, time, and thickness were studied by investigating UV-visible spectra, FT-IR spectra, and XRD of ZnO films. The films were dried and annealed ed at $100^{\circ}C,\;200^{\circ}C$, and $300^{\circ}C$ for 1hr, 2hrs, and 3hrs, respectively. The film showed the preferred (0 0 2) orientation and high transmittance near 90% in the visible range. Also, SEM images of the films exhibited very smooth surfaces without holes and cracks. Schottky diodes were fabricated by using ZnO sol-gel material. Au and Al were used as electrodes to make Ohmic and Schottky contacts, respectively. The annealing temperature, time and the thickness dependent I-V characteristics were presented in this article.

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Effects of Formulation Variables and Drinking Temperature on Acceptability of Jujube Tea Products (배합비와 음용 온도가 대추차의 기호도에 미치는 영향)

  • 최광수;임무혁;최종동
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.5
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    • pp.827-830
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    • 1997
  • Sensory evaluation method was used to develop a type jujube tea the organoleptic properties were evaluated with regard to the optimum sugar content, clarity, drinking temperature and fruit pulp content of the jujube tea. Clarified jujube tea extracted from 25% by weight of dry jujube fruits and 75% water was preferred to those from 15%, 20% and 30% jujube fruites although those from 20% and 30% were not significantly different at 5%level. In spite of the average acceptability score of cloudy jujube tea with 5% of added fruit pulp was not significantly different from that of clarified one, the more fruit pulp in the tea products the worse its acceptability. Cold jujube tea was preferred to warm and hot ones, but these were not significantly different.

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Characterization of $RuO_2$ Thin Films by Hot-wall Metal Organic Chemical Vapor Deposition (Hot-wall MOCVD에 의한 $RuO_2$ 박막의 특성)

  • 신웅철;윤순길
    • Journal of the Korean Ceramic Society
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    • v.33 no.9
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    • pp.969-976
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    • 1996
  • RuO2 thin films were deposited on SiO2(1000 $\AA$)/Si by hot-wall Metal Organic Chemical Vapor Depositon. The crystallinity of RuO2 thin films increased with increasing deposition temperature and the preferred orienta-tion of RuO2 films converted (200) plane to (101) plane with increasing film thicknesses. Such a change in preferred orientation was influenced on the crystallographic structure and the residual stress of RuO2 thin films. The resistivity of the 2700$\AA$-thick RuO2 thin films deposted at 30$0^{\circ}C$ was 52.7$\mu$$\Omega$-cm and they could be applicable to bottom electrodes of high dielectric materials. However the resistivity of RuO2 thin films increased with decreasing film thicknesses. The grain size and the resistivity of RuO2 thin films were densified with increasing the annealing temperature and showed the decrease of resistivity.

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Microstructure of Zinc electrodeposit in Cyanide Solution (시안화아연욕을 사랑한 아연 전착층의 조직특성)

  • Ye G.C;Cho E.H.
    • Journal of Surface Science and Engineering
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    • v.17 no.2
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    • pp.41-58
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    • 1984
  • Zinc was electrodeposited from cyanide solutions at temperature from 20$^{\circ}C\;to\;40^{\circ}C$ in the range of current density from 0.5 to 8A/$dm^2$. The preferred orientation changed from (10.3)+(11.0) to (11.0) texture with increasing cathode overpotential in the additive free solution, while the (11.0) preferred orientation developed at lower overpotentials (800-1270 mV) and the (11.0)+(10.0) preferred orientation was formed at higher overpotential (1300-1400mV) in the solution with brightner. Mossy type of morphology developed mostly in the additive free deposits and the microstructure of the cross section of the above deposits changed from columar structure to granular structure with increasing overpotential. The surface appearance of the deposits with additive having (11.0) texture was the smooth deposit of very small crystallite, while that of the deposits having (11.0)+(10.0) texture was fine crystalline deposit. The microstructure of the cross section of them was the fine field oriented type of structure.

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Orientation Characteristics of AIN Thin Film using RF Magnetron Sputtering wish Incident Angle (입사각을 가진 RF 마그네트론 스퍼터링법으로 증착한 AIN 박막의 배향 특성)

  • 박영순;김덕규;송민종;박춘배
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.395-398
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    • 2000
  • Reactive radio frequency (RF)magnetron sputter with incident angle has been used to deposit AlN thin film on a crystalline Si substrate. (002)Preferred orientation of AlN thin film has been obtained at low sputtering pressure. Also it has been shown that depostion rate of AIN thin film is affected by fraction Ar and $N_2$ partial pressure. But substrate temperature didn't affect depostion rate of AIN thin film . As sputtering pressure increased preferred orientation degraded. The internal stress changed from tensile stress to compressive stress as fraction of $N_2$ partial pressure increased. At low nitrogen partial pressure cermet$^{[1]}$ AIN thin film is obtained.

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