• 대한의용생체공학회:의공학회지
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• 제34권2호
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• pp.73-79
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• 2013

Purpose: The purposes of this study were to measure the dose distribution of Photodynamic therapy(PDT) laser with 635 nm wavelength using GafChromic film. Method & Result: We made each output 300 J by changing mW and sec using the laser beam radiation mode such as C.W(Continuous Wave) mode, Pulse mode and Burst Pulse mode and measured the does at 0 mm and 5 mm of distance from optic fiber catheter end to the film, and at 5 mm distance by changing the angle of the end of the optic fiber catheter as $0^{\circ}$ and $0.5^{\circ}$. The radiated film was scanned and OD(Optical Density) was compared. And two-dimensional isodose curves were obtained and the consistency of shapes was compared. It was confirmed that there was consistency between optic density and the dose radiated on the film when we radiated GafChromic film by changing distance and angle of 300 J output in each radiation mode coordinating mW and sec. Conclusion: In this study, we could identify the stability according to changes in laser beam modes, changes in output according to distance, changes in uniformity according to angle, and beam profiles using GafChromic film, and we could also get two-dimensional isodose curve. It was found that small change in the distance and angle that is made when optic fiber catheter was contacted on the treatment area did not make big effects on the output of beam and the uniformity of dose, and it was also found that GafChromic film could be utilized for the purpose of QA of PDT laser beam.

• 한국정밀공학회지
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• 제16권3호통권96호
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• pp.62-71
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• 1999

Integrating micro-machined sensors and actuators on the conventional devices with the copper power lines was incompatible to fabricate the mass produced micro electromechanical system (MEMS) devices. To achieve the compatibility of the wiring method between MEMS parts and devices, we developed the three-dimensional sputter-evaporation system that coats micropatterned thin copper films on the surface of the MEMS element. The system consists of a process chamber, two branch chambers, the substrate holder, and a linear-rotary motion feedthrough. Thin copper film was sputtered and evaporated on the biocompatible polymer, Pellethane$^{circed{R}}$ and silicone, catheter that is 2 mm in diameter and 700 mm in length. The metal film coating technique with three-dimensional thin film sputter-evaporation system was developed to apply the power and signal lines on the micro active endoscope. In this paper, we developed the three-dimensional metal film sputter-evaporation system operated on the low temperature for the biopolymeric substrates used in the medical MEMS devices.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.120-123
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• 2002

In this study it had an excellent optical characteristic, it followed in the creation rate and the refractive index regulation to the ease. Chalcogenide produced the $As_{45}Se_{45}Te_{10}$ thin film and the $MgF_{2}$ thin film. It measured thin film plan simulation, and the thin film has a 1 -dimensional photonic band gap. The chalcogenide $As_{45}Se_{45}Te_{10}$ thin film was measured with the fact that it has a high refractive index (2.6~2.9). The $As_{45}Se_{45}Te_{10}$ and $MgF_{2}$ thin film, have a high refractive index and a low refractive index, it used a simulation and planed period 5-pairs structure, the result was from 500nm to 800nm. It will be able to confirm the characteristic which most of the incidence light reflects, the He-Ne (632.8nm) laser was irradiated in the thin film which stabilized the thin film. $As_{45}Se_{45}Te_{10}$ (high refractive index layer: H) and $MgF_{2}$ (low refractive index layer: L) results which plans the thin film with glass/LHLHLLHLHL/air structure, 632.8nm against transmitance, increased a lot. An application possibility with the filter against a specific wave length was confirmed.

• Tribology and Lubricants
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• 제17권3호
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• pp.228-235
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• 2001

EHL analysis of connecting rod bearing is proposed which includes effects of temperature variation in lubrication film. Lubrication film temperature is treated as a time-dependent, two-dimensional variable which is averaged over the film thickness, while connecting rod big end temperature is assumed to be time-independent and three-dimensional. It is assumed that a portion of the heat generated by viscous dissipation in the lubrication film is absorbed by the film itself, and the remainder flows into the bearing surface. Mass-conserving cavitation algorithm is applied and the effect of variable viscosity is included to solve the Reynolds equation. Simulation results of the connecting rod bearing in internal combustion engine are presented. It is shown that the temperature variation has remarkable effects on the bearing performance. It is concluded that the EHL analysis considering effects of the temperature variation is strongly recommended to predict the connecting rod bearing performance in internal combustion engine.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.95-98
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• 2000

Film bulk acoustic resonator used in microwave region can be analyzed by one-dimension Mason's model and one-dimensional numerical method, but it had several constraints to analyze effects of area variation, electrode-area variation, electrode-shape variation and spurious characteristics. To overcome these constraints film bulk acoustic resonator must be analysed by three dimensional numerical method. So, in this paper three dimensional finite element method was used to analyze several moles of resonance and was compared with the one dimension Mason's model analysis and analytic solution.

• Nano
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• 제13권10호
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• pp.1850120.1-1850120.9
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• 2018

Two-dimensional poly(dimethylsiloxane) (PDMS) films with wavy patterns were studied in order to investigate reversible and irreversible wetting effects. Pre-strained, surface oxidized layers of PDMS were used to form relieved wavy geometries, on which hydrophobic functionalization was carried out in order to produce irreversible wetting effects. Wavy-patterned PDMS films showed time-dependent reversible wetting effects. The degree of surface wettability could be tuned by the choice of wavy groove geometries. And the groove geometries were controlled via $O_2$ plasma treatment and mechanical pre-straining. The pre-strained, buckled PDMS films were applied to the fabrication of hydrophobic polystyrene nano-patterns using colloidal self-assembly, where the colloids were arrayed in two-dimensional way. The wavy polystyrene films were found to be more hydrophobic relative to flat polystyrene films. The grooving methodology used in this study could be applied to enhancing the hydrophobicity of other types of polymeric thin films, eliminating the need for chemical treatment.

• Composites Research
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• 제29권4호
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• pp.151-155
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• 2016

그래핀은 저차원 구조에서 기인하는 우수한 특성으로 인해 슈퍼커패시터의 전극소재로 응용이 가능한 소재이다. 본 연구에서는 2차원 구조인 그래핀의 비 표면적 향상을 위해 다공성 니켈 나노구조체 표면에 열 화학기상증착법과 마이크로웨이브 플라즈마 화학기상증착법을 이용하여 3차원의 그래핀을 합성하였다. 주사전자현미경, 라만 분광법, X-선 광전자 분광법을 통해 합성된 그래핀의 구조적, 화학적 특성을 분석한 결과, 3차원 구조의 우수한 결정성을 지니는 다중층 그래핀이 다양한 기판 위에 합성된 것을 확인할 수 있었다.

• 폴리머
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• 제34권6호
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• pp.560-564
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• 2010

LCD에 사용되는 편광판 제조 시, 치수안정성 및 내습성 향상을 위한 트리아세틸셀룰로오스(TAC) 필름 접착에 적용되는 폴리(비닐 알코올)(PVA) 접착제의 가수화도 및 분자량이 편광판 치수안정성에 미치는 영향을 살펴보았다. TAC 필름과 PVA 편광판의 접착력은 접착제의 탈아세틸화가 70%에서 최대가 되며 PVA 분자량은 가수화도가 70% 이하에서는 접착력에 영향을 미치지 않는 반면 70% 이상에서는 아세틸화에 의한 분자량 감소가 접착력에 영향을 줌을 알 수 있다. 편광판의 치수안정성은 분자량이 낮은 접착제를 사용할 경우 안정적이며 필름과 편광판의 접착력보다는 접착제의 가수화도에 더 의존적임을 확인할 수 있었다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.448-451
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• 2007

DuPont Teijin $Films^{TM}$ (DTF) have developed engineered substrates specifically for the flexible electronics market. $Teonex^{(R)}$ Q65, $Melinex^{(R)}$ ST506 and ST504 are biaxially oriented crystalline polyesters with the option of planarised surfaces. These films are emerging as competitive materials for the base substrate in OLED displays and active matrix backplanes. Given the demanding dimensional reproducibility requirements in the display applications, it is critical to control the several factors that can influence the film distortion in order to achieve the ultimate performance. This paper will discuss the impact of thermal stress, mechanical stress and the processing environment on dimensional reproducibility of polyester film and give examples of how this impacts on the film in device manufacture.

• Journal of Mechanical Science and Technology
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• 제16권9호
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• pp.1121-1136
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• 2002

The flow characteristics of film coolant issuing into turbulent boundary layer developing on a convex surface have been investigated by means of flow visualization and three-dimensional velocity measurement. The Schlieren optical system with a spark light source was adopted to visualize the jet trajectory injected at 35° and 90° inclination angles. A five-hole directional pressure probe was used to measure three-dimensional mean velocity components at the injection angle of 35°. Flow visualization shows that at the 90° injection, the jet flow is greatly changed near the jet exit due to strong interaction with the crossflow. On the other hand, the balance between radial pressure gradient and centrifugal force plays an important role to govern the jet flow at the 35° injection. The velocity measurement shows that at a velocity ratio of 0.5, the curvature stabilizes downstream flow, which results in weakening of the bound vortex structure. However, the injectant flow is separated from the convex wall gradually, and the bound vortex maintains its structure far downstream at a velocity ratio of 1.98 with two pairs of counter rotating vortices.