• 산업기술연구
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• 제21권B호
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• pp.149-153
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• 2001

A study on the particle growth in $TEOS/O_2$ plasma was performed, and particle size and its distribution was measured by the electrical aerosol analyzer (EAA), light scattering particle size analyzer and the particle size was also determined by SEM. The effects of process variables such as total gas flow rate, reactor pressure, supplied power and initial reactant concentration on the particle growth were investigated. From the EAA results, the particle size distribution is divided into three groups of the cluster size and the small and large size particles. The particle size distribution measured by the light scattering particle size analyzer becomes bimodal, because the cluster size particles smaller than 20 nm in diameter cannot be detected by the light scattering particle size analyzer. The size of particles measured by the light scattering particle size analyzer is in good agreements with those by the SEM. Also we could understand that the particle formation is very sensitive to the changes of reactor pressure and reactant concentration. As the total gas flow rate increases, the particle size decreases because of the shorter residence time. As the reactor pressure, or the reactant concentration increases, the particle concentration increases and the particles grow more quickly by the faster coagulation between particles.

• 한국응용과학기술학회지
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• 제23권4호
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• pp.340-346
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• 2006

The influences of fluorescence, scattering, and flocculation in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength, it has been studied the molecular properties by the spectroscopy of laser induced fluorescence (LIF). The effects of optical properties in scattering media have been found by the optical $parameters({\mu}_s,\;{\mu}_a,\;{\mu}_t)$. Flocculation is an important step in many solid-liquid separation processes and is widely used. When two particles approach each other, interactions of several colloid particles can come into play which may have major effect on the flocculation and LIF process, The value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of scatterer it has been found that the slope decays exponentially as a function of distance from laser source to detector. It may also aid in designing the best model for oil chemistry, biopharmaceutical products, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

• Transactions on Electrical and Electronic Materials
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• 제5권3호
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• pp.104-108
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• 2004

Problems of overlap errors and side-lobe printing by the design rule reduction in the lithography process using attenuated phase-shifting masks(attPSM) have been serious. Overlap errors and side-lobes can be simultaneously solved by the rule-based correction using scattering bars with the rules extracted from test patterns. Process parameters affecting the attPSM lithography simulation have been determined by the fitting method to the process data. Overlap errors have been solved applying the correction rules to the metal patterns overlapped with contact/via. Moreover, the optimal insertion rule of the scattering bars has made it possible to suppress the side-lobes and to get additional pattern fidelity at the same time.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2004년도 춘계학술대회 발표 논문집
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• pp.159-162
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• 2004

Problems of overlap errors and sidelobe printing by the design rule reduction in the lithography process using attenuated phase-shifting masks(attPSM) have been serious. Overlap errors and sidelobes can be simultaneously solved by the rule-based correction using scattering bars with the rules extracted from test patterns. Process parameters affecting the attPSM lithography simulation have been determined by the fitting method to the process data. Overlap errors have been solved applying the correction rules to the metal patterns overlapped with contact/via. Moreover, the optimal insertion rule of the scattering bars has made it possible to suppress the sidelobes and to get additional pattern fidelity at the same time.

• 한국음향학회지
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• 제25권7호
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• pp.339-345
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• 2006

본 논문에서는 다중 산란 현상을 해석할 수 있는 2차원 양방향 포물선 방정식 알고리즘을 제안했다. 본 논문에서 제안한 방법은 단일 산란 근사의 연속적인 적용에 바탕을 두고 있다. 각각의 거리 독립 구역의 수직 경계에 연속 조건을 적용하여 단일 산란 근사와 Split-Step Pade 법으로 거리 방향으로 전진해 가며 외향파를 계산하고 내향파 성분은 저장한다. 이어서 저장된 내향파 성분을 역 거리 방향으로 역 전파 시키고 경계에서 외향파 성분을 저장한다. 이러한 과정을 전진 방향을 바꾸어 가며 해가 수렴할 때까지 반복하여 완전 해를 계산한다. 본 논문에서 제안된 방법은 기존의 방법 [J. F. Lingevitch et al., 5. Accost. Soc. Am. 112(2), 476-480 (2002)] 에 비해 수치적으로 구현하기 간단하며 전산자원 소모가 적다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.5-5
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• 2011

Raman spectroscopy has become one of the most widely used tools in graphene research. The resonant Raman scattering process that gives rise to the observed strong Raman signal carries information regarding the electronic structure as well as the structural properties. When polarization of the incident excitation laser light or the scattered signal is carefully controlled, more information on the electronic and structural properties becomes available. In this tutorial, the basics of polarized Raman scattering experiments will be introduced first. Then several examples from real research will be highlighted to illustrate the application of polarized Raman spectroscopy in graphene research.

• 한국기계가공학회지
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• 제18권2호
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• pp.91-95
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• 2019

A new experimental approach is proposed to detect a specific polymer dissolved in a liquid. Distinctive optical properties were found using a laser scattering technique when there is a polymer compound with almost no difference in optical properties (index of refraction) in a liquid phase. The index of refraction, which determines the refraction of light, is obtained by dissolving PCL and PLA. The used samples are biodegradable materials with similar properties and dissolved in a mixture of Chloroform 7: Methanol 3. To predict the optical properties, a 632-nm diode laser was used as the light source of the device, and an integrating sphere was used as the light receiver. Although PCL and PLA had a similar index of refraction of 1.46-1.48, the dissolved PCL showed a relative transmittance of 43%, and the dissolved PLA had a relative transmittance of 34%. The difference in optical properties of the pure polymer compound in the solid state or liquid state is not significantly different, and the difference in the dissolved state in the specific solvent is remarkable because the solubility differs in a specific solution and is randomly distributed.

• 한국연소학회:학술대회논문집
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• 한국연소학회 1997년도 제15회 KOSCO SYMPOSIUM 논문집
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• pp.103-112
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• 1997

In the combustion of the pulverized coal compared with that of liquid fuel or gaseous fuel, serious pollutants such as ash, $NO_x$ and $SO_x$ are released to surroundings. The objective of this study is the reduction of such pollutants in the combustion process. The modeling of cyclone combustor which uses the method of two stage combustion was carried out. The main burner length, scattering angle and air/fuel ratio were considered as parameters. The results show that the shorter the main burner length is, the less the amounts of coals which exit the combustor directly are, but the scattered input of coal is required anyway in order to collect all ashes. It is recommended that the shorter the main burner length is, the less the scattering angle is. And in the case of the scattered input compared with no scattering, the temperature in the combustor is more uniform and the amount of volatile is more reduced.

• Journal of Pharmaceutical Investigation
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• 제17권1호
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• pp.41-46
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• 1987

Oil in water microemulsion containing soybean oil and egg phosphatide was prepared by vacuum high shear mixing and high pressure homogenizing. The laser particle sizer, Coulter counter and photomicroscope were used to determine the particle size distribution at each cycle of homogenizing. Particularly, the laser particle sizer(dynamic light scattering method) was applied to the study of particle size distribution behavior below $1\;{\mu}m$. It was found that the particle size distribution below $1\;{\mu}m$ was shifted to lower size range as the number of passing cycle was increased. Beyond the 7th cycle, however, the particle size distribution was not varied.

• 한국분무공학회지
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• 제7권3호
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• pp.18-23
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• 2002

An evaporating diesel spray of a common rail lnjector was visualized by LIEF technique. This technique makes it possible to separate the vapor and liquid phase images. The experiment was conducted in a constant volume vessel to make a high temperature and high pressure condition. Three images(vapor and liquid phase images from LIEF and a liquid phase image from Mie scattering) were taken simultaneously in one spray event. The major experimental parameters are the injection pressure and the ambient gas pressure. Also, a relative SMD distribution in a liquid phase was obtained by the ratio of the intensities of the fluorescence and the Mie scattering. The results show that the injection pressure and the ambient gas pressure have a close relation with the spray development and air-fuel muting process.