• Journal of Adhesion and Interface
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• v.3 no.3
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• pp.22-29
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• 2002

UV curable coating system described here consists of double layers, namely under layer and top laser coatings. The former consists of organic-inorganic conductive materials and the latter consists of multifunctional acrylates. Transparent double layer coatings were prepared on the transparent substrates i.e. PMMA, PC, PET etc. by the wet and wet coating procedure. Their surface resistances and film properties were measured as a function of the top layer thickness and relative humidity. As the thickness of the top layer was less than $10{\mu}m$, the surface resistance in the range of $10^8{\sim}10^{10}{\Omega}/cm^2$ was obtained. The surface properties of the two-layer coating were remarkably improved compared with the single layer coating. The effects of migration of conducting materials on the film properties of multilayer coating were investigated by using contact angle and Fourier transform infrared/attenuated total reflection(FT-IR/ATR). It was found that the migration of dopant(dodecyl benzenesulfonic acid, DBSA) molecules were occurred from film-substrate interface to film-air interface in the organic conductive coating system but not in the inorganic one.

• The Journal of Korean Society for Radiation Therapy
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• v.34
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• pp.51-60
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• 2022

Objectives: The purpose is to evaluate dosimetric performance and delivery efficiency of VMAT with Halcyon LINAC for double target spine SBRT Materials and Methods: 12 patients with spine oligometastases were retrospectively studied. Single-isocenter spine SBRT plans was established using Halcyon® with Dual Layer MLC and Truebeam® with High Definition MLC. All patients' plans were created in Eclipse TPS through the identical conditions and optimization. C.I, H.I, G.I (Gradient Index), maximal and volumetric doses to spinal cord and low dose area were evaluated for comparison of both plans. Also, total MU and BOT(Beam On Time) were evaluated. Results: Halcyon plans was no Statistical differences in C.I and H.I. However, the average of G.I was 4.64 for Halcyon, which decreased to 5.5% compared to Truebeam (P<0.001). Halcyon plans demonstrated statistically significant reduced G.I. The average of 50% and 25% isodose volume was 487.56 cc (-3.82%, P<0.001), 1859.45 cc (-4.75%, P<0.001) in Halcyon, respectively. Significantly reduced low dose spill were observed in Halcyon plans. In the evaluation of the spinal cord, the average of Dmean and V10 of Halcyon plans in the sample group with an overlap volume of less than 1 cc was 6.802 Gy (-3.504%, P=0.067), 5.766±1.683 cc (-8.199%, P=0.002), respectively. Halcyon plans demonstrated statistically significant reduced D_mean and V10. For delivery efficiency, MU and BOT(maximum dose rate for each machine), on average, increased in Halcyon plans. However, the average of BOT(800MU/min for each machine) was 648.33 sec for Halcyon (-1.74%, P<0.001). Conclusion: Halcyon plan for double-target spine SBRT demonstrated advantages in the low dose area with a steep dose gradient, while having dosimetrically equivalent target dose distribution and spinal cord protective effect. As a result, Halcyon LINAC produced a dosimetrically improved plan for double-target spine SBRT.

• Korean Journal of Materials Research
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• v.19 no.5
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• pp.240-244
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• 2009

Simple and high efficiency green phosphorescent devices using an intermixed double host of 4, 4', 4"-tris(N-carbazolyl) triphenylamine [TCTA], 1, 3, 5-tris (N-phenylbenzimiazole-2-yl) benzene [TPBI], phosphorescent dye of tris(2-phenylpyridine)iridium(III) [$Ir(ppy)_3$], and selective doping in the TPBI region were fabricated, and their electro luminescent characteristics were evaluated. In the device fabrication, layers of $70{\AA}$-TCTA/$90{\AA}$-$TCTA_[0.5}TPBI_{0.5}$/$90{\AA}$-TPBI doped with $Ir(ppy)_3$ of 8% and an undoped layer of $50{\AA}$-TPBI were successively deposited to form an emission region, and SFC137 [proprietary electron transporting material] with three different thicknesses of $300{\AA}$, $500{\AA}$, and $700{\AA}$ were used as an electron transport layer. The device with $500{\AA}$-SFC137 showed the luminance of $48,300\;cd/m^2$ at an applied voltage of 10 V, and a maximum current efficiency of 57 cd/A under a luminance of $230\;cd/m^2$. The peak wavelength in the electroluminescent spectral and color coordinates on the Commission Internationale de I'Eclairage [CIE] chart were 512 nm and (0.31, 0.62), respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1996.11a
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• pp.242-244
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• 1996

The effects of $Co_{67}$C $r_{33}$ underlayer on the crystallographec and magnetic characteristics of the Co-Cr-Ta layer deposited on the underlayer was investigated. The diffraction intensity $I_{p(002)}$ of Co-Cr-Ta layers on the $Co_{67}$C $r_{33}$ layer was stronger than that of single layer and Co-Cr-Ta/Ti double layer. Therefore, the crystallinity of Co-Cr-Ta layer was improved by the $Co_{67}$C $r_{33}$ underlayers rather than Ti ones. However, the coercivity $H_{c}$ of Co-Cr-Ta layers deposited on $Co_{67}$C $r_{33}$ underlayer was as low as 250 Oe even at substrate temperature of 22$0^{\circ}C$. This $H_{c}$ decrease seems to be attributed to the effect of the $Co_{67}$C $r_{33}$ underlayer as well as interval time between deposition of the underlayer and the Co-Cr-Ta layer.yer.layer.yer.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.32A no.7
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• pp.69-76
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• 1995

A new device structure has been developed for p-i-n switches. In this structure, the phosphorus-diffused n$^{+}$ layter adjacent to the boron-doped anode is used to short the p$^{+}$ anode-channel(i-region). This change in the anode electrode structure results in a significant improvement in the threshold voltage-to-holding voltage($V_{Th}/V_{h}$) ratio, which is due to the suppression of the hold injection from the anode by the n$^{+}$ layer. The shorted anode p-i-n devices of a 100 .mu.m channel length show an extremely high threshold voltage in the 250~300 V range and a low holding voltage in the 5~9 V range. These features of the device are expected to acdelerate their practical application to power switching circuits.

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.847-850
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• 1996

The bi-layered films composed of Co-Cr-Ta layers and paramagnetic $Co_{67}Cr_{33}$ underlayer were deposited by suing Facing Targets Sputtering(FTS). The effects of $Co_{67}Cr_{33}$ underlayer on the crystallographic and magnetic characteristics of the Co-Cr-Ta layer deposited on the underlayer was investigated. The diffraction intensity $I_{p(002)}$ of Co-Cr-Ta layers on the $Co_{67}Cr_{33}$ layer was stronger than that of single layer and Co-Cr-Ta/Ti double layer. Therefore, the crystallinity of Co-Cr-Ta layer was imporved by the $Co_{67}Cr_{33}$ underlayer rather than Ti ones. However, te coercivity H$_{c\bot}$ of Co-Cr-Ta layers deposited on $Co_{67}Cr_{33}$ underlayer was as low as 250 Oe even at substrate temperature of $220^{\circ}C$. This H$_{c\bot}$ decrease seems to be attributed to the effect of the $Co_{67}Cr_{33}$ underlayer as well as interval time between deposition of the underlayer and the Co-Cr-Ta layer.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.239-246
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• 2009

The Mode I interlaminar fracture toughness of woven fabric carbon/epoxy and glass/epoxy composites for a train carbody was measured and FEM analysis was conducted. The woven fabric epoxy composite manufactured by hand lay-up, has high stiffness and strength, good resistance for impact, fatigue, corrosion and in-plane failure. The DCB(Double Cantilever Beam) specimen made of woven fabric epoxy composite had the size of 180mm $\times$ 25mm $\times$ 5mm and the insert of 65mm. The Mode I interlaminar toughness of specimen was measured according to ASTM 5528-01. The crack propagation behavior of the DCB specimen was simulated using FEA with cohesive elements that model the adhesive layer between woven fabric plies.

• Korean Journal of Materials Research
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• v.15 no.1
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• pp.1-5
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• 2005

Copper-based leadframe sheets were immersed in two kinds of hot alkaline solutions to form brown-oxide or black-oxide layer on the surface. The oxide-coated leadframe sheets were molded with epoxy molding compound (EMC). After post mold curing, the oxide-coated EMC-leadframe joints were machined to form sandwiched double-cantilever beam (SDCB) specimens. The SDCB specimens were used to measure the fracture toughness of the EMC/leadframe interfaces under quasi-Mode I loading conditions. Fracture surfaces were analyzed by various equipment to investigate failure path. The present paper deals with the failure path, and the cause of the failure path formation with an adhesion model will be treated in the succeeding paper.

• Journal of Sensor Science and Technology
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• v.11 no.3
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• pp.155-162
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• 2002

The sensing properties of carbon monooxide were investigated as a function of mixing ratio and the lamination structure of 3mol% ZnO-doped $SnO_2$ and 3mol% $SnO_2$-doped ZnO. The lamination structures were fabricared monolayer, double layer, and hetero layer of $SnO_2$, Zno, and theirs mixture composition using thick film process. There was no second phase by the reaction of $SnO_2$ and ZnO. The conductance was decreased by the addition of ZnO in $SnO_2$, but it was increased with the addition of $SnO_2$ in ZnO. The conductance was increased with temperature and the inlet of CO. There was no improvement of sensitivity in the structure of mono- and double-layer. The hetero-layer structure, however, of $SnO_2$ 3ZnO-ZnO $3SnO_2$ showed the higher resistivity and the highest sensitivity. Ohmic characteristics was confirmed by the linear properties for I-V measurements.

• Electrical & Electronic Materials
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• v.9 no.7
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• pp.680-689
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• 1996

SrCaCuO와 BiPbCuO 화합물로 이루어진 이중층시료가 만들어 졌으며, 소결과정에서 나타나는 확산과 입자간의 상호작용으로 108K의 임계온도를 나타내었다. 이 시료는 820.deg. C에서 0-210 시간동안 소결되었다. 초전도체의 생성, 성장메카니즘과 임계온도의 관계가 연구되었으며, 최적조건은 820.deg. C에서 210시간 소결하고 SrCaCuO와 BiPbCuO의 도포비가 1:0.6인 시편에서 나타났다. 또한 이중층시료에서 가장 좋은 조성비는 S $r_{2}$C $a_{2}$C $u_{2}$ $O_{x}$와 B $i_{1.9}$P $b_{0.5}$C $u_{3}$ $O_{y}$ 이었다.다.