• 대한소아치과학회지
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• 제32권4호
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• pp.611-619
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• 2005

본 연구의 목적은 초기 우식 병소에서 광원에 따른 형광효과를 비교하는 것으로 정량 분석형 laser/light 형광법(Quantitative laser/light-induced fluorescence, QLF)을 이용하여 아르곤 레이저광, 할로겐광, 발광다이오드광(LED), 플라즈마광의 형광효과를 비교하였다. 발거된 60개의 치아를 선정한 후, 인공우식용액에 노출되지 않을 부분에 nail varnish를 도포하였고 치아는 24, 48, 72시간 동안 인공우식용액에 보관되었다. 건조 후 QLF영상으로 초기 우식 부위의 광밀도 차이에 의한 탈회정도가 기록되었다. 또한 조영제를 이용하여 동일한 방법으로 실험하였고 다음과 같은 결과를 얻었다 염료를 이용하여 같은 방법으로 실험하여 또 다른 결과를 얻었다. 1. 각 군의 평균 광밀도를 볼 때, 플라즈마광이 세 군 모두에서 다른 광원들 보다 높았다(p<0.05). 2. 세 군 사이에서 평균 광밀도를 비교해 볼 때, 플라즈마광과 할로겐광이 차이를 보였다(p<0.05). 3. 조영제를 사용하였을 경우 평균 광밀도를 비교해 볼 때, 플라즈마광이 세 군 모두에서 다른 광원들보다 높았고 (p<0.05), 발광다이오드광(LED)와 아르곤 레이저광을 제외한 모든 광원이 차이를 보였다(p<0.05). 4. 조영제를 사용하지 않은 경우와 사용한 경우 평균 광밀도를 비교해 볼 때, 사용한 경우에 모든 광원의 평균 광밀도 차이가 컸다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.625-626
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• 2008

The magnetic domain-refining techniques such as ball scratching, laser irradiation and plasma have been developed to reduce the domain wall spacing and thus iron losses in Fe-3%Si grain-oriented silicon steels. In view point of magnetic properties, it was supposed that the locally residual stresses change the magnetoelastic energy of the material and thus the spacing between $180^{\circ}$ domain walls decreases in order to reduce the magnetostatic energy. The effect of laser irradiation on iron loss and magnetostriction reduction for Fe-3%Si grain-oriented steel were investigated. Since the local tensile stresses were induced at the surface of Fe-3%Si steel by the laser irradiation, the minimum iron loss caused by reducing eddy current loss was obtained in spiete of the decrease of permeability by hindering eddy current loss was obtained in spite of the decrease of permeability by hindering the domain wall movement around the induced stress field. Furthermore, the laser treated 3%Si steel has lower magnetostriction as compared to non laser-treated steel and is less sensitive to applying pre-stresses due to the volume reduction of $90^{\circ}$ domain in materials.

• 한국조명전기설비학회:학술대회논문집
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• 한국조명전기설비학회 1999년도 학술대회논문집-국제 전기방전 및 플라즈마 심포지엄 Proceedings of 1999 KIIEE Annual Conference-International Symposium of Electrical Discharge and Plasma
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• pp.95-98
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• 1999

This paper describes preliminary discussions on spatial distribution of NO density, which is mostly contained in simulated NOX exhaust, between a wire-cylinder geometry discharge gaps by using Laser Induced Fluorescence(LIF) Spectroscopy. Spatial distribution of NO density will be measured with varying NO concentrations from 166 to 644[ppm] and diameters of central electrode from 6 to 10mm. Pulsed Nd:YAG laser, Optical Parametric Oscillator(OPO), and Frequency Doubler are used to excite NO molecules to their excited state.

• 한국항공우주학회지
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• 제45권6호
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• pp.523-530
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• 2017

높은 에너지의 레이저가 조사되면 레이저 삭마 현상을 일으키고, 결과적으로 플라즈마가 물질에 따라 특정한 파장의 빛을 방출하는 레이저 유도 파괴 분광법(LIBS, Laser-Induced Breakdown Spectroscopy)과 빛은 산란 현상에 대해 분자 간 혹은 분자 내의 회전 및 진동 운동을 측정하는 라만 분광법은 높은 정확도와 실시간 분석이 가능하다는 점, 원거리 검출이 가능하다는 장점들을 기반으로 우주 탐사 기술로써 주목을 받고 있다. 본 연구에서는 레이저 분광법을 활용하여 토양 성분의 변화에 따른 레이저 스펙트럼의 경향성을 파악하고, 이를 기반으로 2차원 화학적 분포도 실험을 진행하였다. 또한 화성(4-7 torr)과 달의 대기(<1 torr) 환경을 레이저 실험 환경 내에 구축하여 인공적인 우주 환경에서 LIBS와 라만 분광법을 활용하여 토양 성분의 변화에 따른 LIBS와 라만 분광법을 통한 계측이 가능함을 증명하였다.

• 전기학회논문지
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• 제58권6호
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• pp.1174-1179
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• 2009

In this paper we develop the characteristic of density on non-uniform plasma in different layer of the semiconductor with optically controlled microwave pulses. The transient response of the microwave pulses in different plasma layer has been evaluated by calculating the variation of the reflection function of dielectric microstrip lines. The lines has used under open-ended termination containing optically induced plasma region, which has illuminated a laser source. The characteristics impedances resulting from the presence of plasma are evaluated by the transmission line model. The analyzes the variation of transient response in a 0.01cm layer near the surface for frequency range from 1GHz to 128GHz. The diffusion length LD is larger than compared to the absorption depth $l/_{\alpha}l$. The variation of characteristic response in plasma layer with microwave pulses which has in deferentially localized has been evaluated analytically.

• 한국정밀공학회지
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• 제29권3호
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• pp.339-345
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• 2012

Electrospun meshed poly-caprolactone PCL was patterned by femtosecond laser with linear grooves. As parametric variables, focus spot size, pulse energy, and scanning speed were varied to determine the affects on groove size and the characteristics of the electrospun fiber at the edges of these grooves. The femtosecond laser was seen to be an effective means for flexibly structuring the surface of ES PCL scaffolds and the width of the ablated grooves was well controlled by laser energy and focus spot size. The ablation threshold was measured to be $14.9J/cm^2$ which is a little higher than other polymers. These affects were attributed to optical multiple reflections inside nano-fibers. By the laser-induced plasma at higher pulse energies, some melting of fibers was observed.

• Rapid Communication in Photoscience
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• 제4권3호
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• pp.50-53
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• 2015

$SnO_2$ thin films were deposited on fused silica substrate by pulsed laser deposition under transverse magnetic field. We have explored the effects of magnetic field and ablation laser wavelength on the optical properties of laser-induced plasma plume and structural characteristics of the deposited $SnO_2$ films. Optical emission from the plume was monitored using an optical fiber to examine the influence of magnetic field on the population of the excited neutral and ionic species and their decay with times after laser ablation. Also, we employed photoluminescence, x-ray diffraction, and UV-Vis absorption to characterize $SnO_2$ films.

• Journal of Welding and Joining
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• 제32권6호
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• pp.70-74
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• 2014

On this study, we researched the in-process monitoring during fiber laser welding as well as on the first paper. On the previous/formal study, we analyzed the change of emission signal on thin plate welding. On this study, however, we analyzed RMS and FFT with emission signals in laser welding on lap joint and butt joint of 8mm-thick 316L stainless steel. As the result, the movement of specific frequency peak was observed according to welding speed changes. Furthermore, frequency peak as a result of FFT on the thick plate welding are much clearer than on the thin plate welding. Therefore, it is expected that the welding parameter changes can be predicted in case of applying FFT to in-process monitoring.

• Medical Lasers
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• 제9권1호
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• pp.12-24
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• 2020

Human fibroblast-derived multi-peptide factors (MPFs) have been used during treatments with energy-delivering modalities to enhance energy-induced tissue reactions. Human fibroblast-derived MPFs, which include a range of growth factors and chemoattractive factors, activate and recruit fibroblasts and endothelial cells, as well as promote extracellular matrix deposition, all of which are crucial to wound repair. Interestingly, fibroblasts from different species or anatomical sites exhibit distinct transcriptional properties with high heterogeneity. In addition, the patterns of MPF secretion can differ under a range of experimental conditions. Therefore, the use of allogeneic fibroblasts and proper cultivation thereof are necessary to obtain MPFs that can enhance the epithelial-mesenchymal interactions during wound repair. Moreover, energy-delivering devices should be selected according to evidence demonstrating their therapeutic efficacy and safety on a pathological skin condition and the major target skin layers. This paper reviewed the histologic patterns of post-treatment tissue reactions elicited by several energy sources, including non-ablative and ablative fractional lasers, intense focused ultrasound, non-invasive and invasive radiofrequency, picosecond-domain lasers, and argon and nitrogen plasma. The possible role of the immediate application of human fibroblast-derived MPFs during wound repair was proposed.

• 한국광학회:학술대회논문집
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• 한국광학회 2001년도 하계학술발표회
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• pp.186-187
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• 2001

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