• 한국안광학회지
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• 제4권1호
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• pp.51-56
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• 1999

금속 안경테의 제조에 가장 많이 사용되는 범용 양백의 표면에 2%Ti-naphthanate toluene solution을 $TiO_2$의 전구체로 하여 sol-gel spin coating을 행하고 $500^{\circ}C$에서 열처리 한 코팅 층의 형성조건 및 표면 구조 그리고 표면색상을 Optical photometer외 색차계 그리고 X-선 회절분석기로 분석한 결과 다음과 같은 결론을 얻었다. $TiO_2$ 박막의 열처리 온도는 $500^{\circ}C$가 적정하였으며 1회 코팅 시의 평균 두께는 $0.24{\mu}m$이었으며 코팅 횟수 증가에 따라 직선적으로 증가하였다. $TiO_2$ 코팅 층의 결정구조는 비정질 상태로 존재하였고 색상은 코팅 횟수에 따라 변화하였으며 2회 코팅한 경우는 적색이 미세하게 출현하였으며 3회 코팅한 경우에는 검붉은 색이 발현되었다. 명도는 55.92(1회)에서 코팅 횟수가 증가함에 따라 점차 저하하였으며 a는 3회 코팅까지는 red계열로 증가하다가 급격히 저하하며, b는 꾸준히 감소하여 blue계열로 변화하는 경향을 보였다. 금 색상의 발현을 위해서는 1회 코팅인 $0.24{\mu}m$ 두께의 $TiO_2$ 비정질 막이 적합하였다.

• Journal of Mechanical Science and Technology
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• 제14권1호
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• pp.113-120
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• 2000

This study has developed a new liquid crystal calibration technique using Neural networks with median filtering and applied this technique to heat transfer measurements. To verify the validity of this new measurement technique, the local Nusselt numbers on a flat plate surface subjected to an axisymmetric impinging jet were measured and compared with the results by the conventional Hue-temperature calibration technique under the same conditions. Because the Neural networks predict the non-linear relations between temperatures and corresponding R, G, B values, Neural networks-median filtering calibration technique can utilize a much wider color band in the experiment than the Hue-temperature calibration technique, resulting in a significant reduction in the experimental time.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 D
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• pp.1803-1805
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• 1999

The thermal expansion coefficient of the titania-fused silica glass$(TiO_2-SiO_2)$ called KLR-1.1 is known to $0{\pm}0.03$ ppm/K, while that of normal fused-silica glasses is about +0.5 ppm/K at room temperature. To analysis the dielectric properties of the KLR-1.1, the sample with diameter of 30 mm and thinkness of 1 mm is covered with gold film. Its relative permittivity and dissipation factor of KLR-1.1 is evaluated to $4.011{\pm}0.012(1\sigma)$ and $(4.86{\pm}0.02){\times}10^{-4}(1{\sigma})$ at 1 kHz respectively. The measurement techniques used and results are more discussed in this paper.

• Bulletin of the Korean Chemical Society
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• 제31권5호
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• pp.1223-1227
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• 2010

In this study, the orientational behavior of thermotropic liquid crystals (LC) supported on a film of protein receptors was examined. Avidin was roller printed and covalently immobilized onto the surface of gold using NHS/EDC chemistry. The orientation of nematic 4-cyano-4'-pentylbiphenyl (5CB) was found to be parallel to the plane of the printed avidin surface before incubation with a solution of biotin. However, protein-receptor complexation induced a random orientation of 5CB, where protein-receptor complexes disturbed the nanoscale topography of the printed protein surface. Atomic force microscopy and ellipsometry was used to confirm printing and the specific interaction of proteins. These results demonstrate that the combination of LC and roller printing can be used to detect specific interactions between biomolecules by manipulating the orientational behavior of LC to the printed protein surfaces.

• Bulletin of the Korean Chemical Society
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• 제34권9호
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• pp.2781-2786
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• 2013

We examined the effect of electrode fingers and gaps of coplanar interdigitated electrode (IDE) structures to characterize the ammonium salt-containing polyelectrolyte film of resistance-based humidity sensors. IDEs designed for this purpose were flexible gold electrodes deposited on a polyimide substrate using a printing process because the geometry presents a potential for tunable sensitivity over other electrode designs. The basic design of the sensors consisted of IDEs with a different number of electrode fingers such as 3, 4, and 5 and gap sizes of 310, 360, 410, and $460{\mu}m$. Details of the AC complex impedance characteristics such as the Nyquist plot, Bode plot, and activation energy based on electrode construction were investigated.

• 대한심미치과학회지
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• 제8권1호
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• pp.76-82
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• 1999

Zinc phosphate cement has long been the material of choice for permanent luting of cast restorations, and through many years of use has been considered effective to retain castings. However, cast restorations cemented with this material have been susceptible to secondary caries. Glass ionomer luting agents become available in the late 1970s. These material s, through release of fluoride, show considerable promise as a means of reducing secondary caries. Other favorable traits include significantly less disintegration in vivo than zinc phosphate cements, a film thickness comparable to that of zinc phosphate cement, and adhesion to tooth structure. Compomer materials were created in 1993 as a filling material for deciduous teeth, cervical lesions, and class III cavities. In the meantime, compomer have been developed as chemical hardening cements for cast gold restorations. The aim of this paper is to review the articles on luting cements to help the choice of dental cements.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 Techno-Fair 및 합동춘계학술대회 논문집 전기물성,응용부문
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• pp.165-166
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• 2008

We investigate characteristics of J-aggregation as take advantage of LB technic. In order to confirm the applications possible for the molecular electronic device, the morphological properties of merocyanine dye were investigated by AFM. $\pi$-A curves investigated the surface pressure of the LB film from a liquid to a solid state ranged between 90 and 100 mN/m. We observed aggregation and it's characteristics by using visible reflection spectroscopy. We have observed morphology of merocyanine dye on gold surface by STM. focuses on results obtained in mercocyanide dye of J-aggregation. When LB films of merocyanine dye are mixed with arachidic acid, J-aggregate formation is exhibited. J-aggregate formation has been serving as typical systems in revealing the physical and structural aspects of nano-sized molecular aggregates constructed as muiltilayers.

• Smart Structures and Systems
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• 제4권5호
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• pp.531-548
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• 2008

Recently, dense sensor instrumentation for structural health monitoring has motivated the need for novel passive wireless sensors that do not require a portable power source, such as batteries. Using a layer-by-layer self-assembly process, nano-structured multifunctional carbon nanotube-based thin film sensors of controlled morphology are fabricated. Through judicious selection of polyelectrolytic constituents, specific sensing transduction mechanisms can be encoded within these homogenous thin films. In this study, the thin films are specifically designed to change electrical properties to strain and pH stimulus. Validation of wireless communications is performed using traditional magnetic coil antennas of various turns for passive RFID (radio frequency identification) applications. Preliminary experimental results shown in this study have identified characteristic frequency and bandwidth changes in tandem with varying strain and pH, respectively. Finally, ongoing research is presented on the use of gold nanocolloids and carbon nanotubes during layer-by-layer assembly to fabricate highly conductive coil antennas for wireless communications.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 하계학술대회 논문집 B
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• pp.760-761
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• 2001

We have studied quench characteristics for current limiting elements of YBCO films in applied fields of 0 - 130 mT. The films were deposited on sapphire substrates and covered by gold top layer. The current limiting element consists of 2 mm wide YBCO stripes connected in series. The electric field - current density (E-J) measurements showed that the presence of applied magnetic fields induces uniform quench distribution for the stripes, otherwise non-uniform quenches were observed. We suggest that suppressing the critical current by increased fields due to fault current effectively forced the stripes of higher Jc(0) to quench, resulting in equalizing quench times.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1998년도 추계학술대회 논문집 학회본부 C
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• pp.1061-1064
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• 1998

To examine the influence of unsteady wake on the flow and heat transfer characteristics, an experiment has been conducted in a four-vane linear cascade. Flow and heat transfer measurements are made for the inlet Reynolds number of 66000(based on chord length and free-stream velocity). Turbulent intensity and stress were measured using hot wire anemometer, and to measure the convective heat transfer coefficients on the blade surfaces liquid crystal/gold film Intrex technique was used. The disturbance by the unsteady wake is characterized by the unresolved unsteadiness. The unsteady wake enhances the turbulent motion of flow in the cascade passage. It also promotes the boundary layer development and transition. The results show that heat transfer coefficients on the suction surface increase with increasing unresolved unsteadiness.