• Title/Summary/Keyword: laser intensity

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Comparison between Moxibustion and the Intense Pulsed Light (IPL) and the Clinical Application of Photo-moxa (구법(灸法)과 intense pulsed light(IPL)의 특성 비교 및 광선구(光線灸)의 한방임상(韓方臨床) 활용(活用))

  • Jang, In-Soo;Sun, Seung-Ho;Nam, Dong-Hyun;Kum, Su-Eun;Seo, Hyung-Sik
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.23 no.3
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    • pp.78-83
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    • 2010
  • Objectives : The purpose of this study is to compare the principles between moxibustion and the 'Intense pulsed light (IPL)' and to investigate the clinical application of the photo-moxa for the Korean medicine fields. Methods : The characteristics of moxibustion, IPL, parabolic reflector moxa and the dermatology surgical use of moxibustion were reviewed in the literature. Results : IPL is one type of light treatments that is employed by radiating the short-pulse wave, which is transformed from the light of high intensity. There has been used parabolic reflector in Asia for more than 2,000 years, and this hand-held device used for moxibustion in traditional medicine. Moxibustion is one of the treatment tools in Korean medicine using the heat energy. The fluence or energy density of IPL in clinical circumstances is similar to parabolic reflector moxa of moxibustion. IPL and parabolic reflector moxa shared same treatment principle employing the heat energy. Therefore IPL could apply for many indications in Korean medicine as a moxibustion tool and acupuncture. Conclusions: IPL may be plausible to be a fascinate method in phototherapy of Korean medicine.

Polarization multiplexing of holography memory in photopolymer (포토폴리머에서 편광방식을 이용한 홀로그래픽 메모리의 다중화)

  • Jeong, Hyeon-Seop;Kim, Nam;Sin, Chang-Won;Kim, Eun-Gyeong
    • Proceedings of the Optical Society of Korea Conference
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    • 2007.07a
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    • pp.275-276
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    • 2007
  • A multiplex recording and reading technique in photopolymer are presented In order to record the polarization gratings, polarization-sensitive materials, in which linear birefringence is induced by irradiating the polarized light, are necessary. We checked orthogonal and independence of laser. The value of the photoinduced linear polarization had effect on diffraction properties in the holographic gratings. The grating strengths of two polarization are investigated and the relevant parameters for equal diffraction intensity readout are optimized.

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Verification on Diffusion of Beam Propagation in Randomly Distributed Scattering Medium (무질서하게 분포된 산란매질에서 빔전파의 확산에 관한 검증)

  • Kim, Ki-Jun;Lee, Hoo-Seol
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.4
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    • pp.354-361
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    • 2007
  • The distribution of light in a randomly scattering medium can represent problems found in many area. Particularly, in the clinical application of lasers for Photodynamic therapy(PDT) or in the fluorescence spectroscopy for biological tissue, turbidity plays a very important role. The influences of fluorophor, scatterer, and absorber in turbid material by light scattering were interpreted for the scattered fluorescence intensity and wavelength. The molecular properties have been studied by laser induced fluorescence spectroscopy in scattering medium as tissue. It has been found that the effects of optical properties in scattering media could be investigated by the optical $parameters({\mu}_s$, ${\mu}_a$ ,${\mu}t)$. Experimental and Monte Carlo simulation method for modelling light transport in tissue was applied. The experimental results using a randomly distributed scattering medium were discussed and compared with those obtained through Monte Carlo simulation. It'll be also important in designing the best model for oil chemistry, medicine and application of medical engineering.

Characterization of the internal flow and fuel spray from an impinging flow nozzle (노즐분공내 유체충돌이 있는 디젤노즐의 유동 및 분무특성 연구)

  • Ha, Seong-Eop;Kim, Heung-Yeol;Gu, Ja-Ye;Ryu, Gu-Yeong
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.21 no.12
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    • pp.1635-1646
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    • 1997
  • The nozzle length to diameter ratio of real diesel nozzles is about 2-8 which is not long enough for a fully developed and stabilized flow. The characteristics of the flow such as turbulence at the nozzle exit which affect the development of the spray can be enhanced by impinging the flow inside nozzle. The flow details inside the impinging nozzles have been investigated both experimentally and numerically. The mean velocities, the fluctuating velocities, and discharge coefficients in the impinging inlet nozzles, round inlet nozzle, and sharp inlet nozzle were obtained at various Reynolds number. The developing feature of the external spray were photographed by still camera and the droplet sizes and velocities were also measured by laser Doppler technique. The spray angle was greater and the droplet sizes near the spray axis were smaller with the impinging flow inside nozzle.

Analysis of a wavelength tunable source according to temperature variations in a Mutually Injected F-P LD (상호주입 잠김 F-P LD에서 온도변화에 따른 가변 파장 광원의 특성 분석)

  • Hwang, Ji-hong;Oh, Yeong-guk;Lee, Hyuek-jae;Lee, Chang-hee
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.10a
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    • pp.1009-1011
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    • 2012
  • In this paper, a wavelength tunable light source based on mutually injected locking with two F-P LDs, has been constructed and then analyzed for wavelength shift and RIN (Relative Intensity noise) according to temperature. We have measured maximum about 2 nm for the wavelength shift and minimum -110dB/hz for the RIN. Also, the RIN and beating noise in eye patterns are increased by changing temperature high.

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Flow Cytometric Analysis of Bovine Granulosa Cells : Changes of Cell Cycle During Follicular Maturation (Flow Cytometer를 이용한 소 과립막세포의 분석 : 난포성숙에 따른 세포주기의 변화)

  • 김해정;김동훈;이훈택;정길생
    • Korean Journal of Animal Reproduction
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    • v.17 no.4
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    • pp.279-285
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    • 1994
  • The objective of the present study was to characterize the cell cycles of granulosa cell populations during follicular maturation in cattle by using flow cytometer. Granulosa cells were isolated from bovine preovulatory antral follicles of F1(>10mm), F2(5~20mm), F3(3~4mm) and F4(1~2mm) diameter and fixed and stained with fluorochromes that selectively bine to DNA. Flow cytometer equipped with a laser excitation system was used to analyze the intensity of fluorescence from stained cells. Forward angle light-scatter(FSC) and 90$^{\circ}$light-scatter(SSC) signals were adopted to measure the size and the granularity of granulosa cells. As a results of FSC/SSC analysis, granulosa cell populations(G1 phase of cell cycle) from each follicle were relatively regular in size and granularity, regardless of follicular size. However, their distribution in granularity was greater than that in size. Most of granulosa cell populations collected from each follicle were distributed in G0/G1, S and G2/M phases. As the follicles approached to ovulation the percentage of cells in the proliferative phases of cell cycle (S and G2/M) decreased significantly, but there was a concomitant increase in the percentage of granulosa cells in G1 phase. Therefore, these data indicate the proportion of main populations to cell cycle of granulosa cells may be changed from proliferative phase to G1 phase during follicular maturation in cattle.

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SELF-PULSATION CHARACTERISTICS OF A SWIRL COAXIAL INJECTOR WITH VARIOUS INJECTION AND GEOMETRIC CONDITIONS

  • Im, Ji-Hyuk;Kim, Dong-Jun;Yoon, Young-Bin;Bazarov, V.
    • Journal of ILASS-Korea
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    • v.10 no.3
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    • pp.29-37
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    • 2005
  • The spray and acoustic characteristics of a gas/liquid swirl coaxial injector are studied experimentally. The self-pulsation is defined as a pressure and flow rate oscillations by a time-delayed feedback between liquid and gas phase. Self-pulsation has strong influences on atomization and mixing processes and accompanies painful screams. So. the spray and acoustic characteristics are investigated. Spray patterns are observed by shadow photography technique in order to determine the onset of self-pulsation. And self-pulsation boundary with Injection conditions and recess length is get. To measure the frequency of the spray oscillation. oscillation of the laser intensity which passes through spray is analyzed by Fast Fourier Transform. For acoustic tests, a PULSE System was used. Acoustic characteristics of a swirl coaxial injector are investigated according to the injection conditions. such as the pressure drop or the liquid and gas phase. and injector geometries. such as recess length and gap size between the inner and outer injector. Front the experimental results. the increase of recess length leads to the rapid increase of the sound pressure level. And as the pressure drop of the liquid phase increases. the frequency of the self?pulsation shifts to the higher frequency. The frequency of spray oscillations is the same as that of the acoustic fields by self-pulsation.

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Thermosensitive Block Copolymers Consisting of Poly(N-isopropylacrylamide) and Star Shape Oligo(ethylene oxide)

  • Lee, Seung-Cheol;Chang, Ji-Young
    • Bulletin of the Korean Chemical Society
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    • v.30 no.7
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    • pp.1521-1525
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    • 2009
  • Thermosensitive block copolymers of ethylene oxide and N-isopropylacrylamide (NIPAM) were synthesized. A five armed star shape oligo(ethylene oxide) initiator with a cyclotriphosphazene core was prepared and used for the atom transfer radical polymerization (ATRP) of NIPAM. The lower critical solution temperatures (LCSTs) of the copolymers were 36 to 46 ${^{\circ}C}$, higher than that of PNIPAM (32 ${^{\circ}C}$), depending on their molecular weights. The copolymers were soluble in water below the LCSTs but formed micelles above the LCSTs. The thermosensitive micellization behaviors of the polymers were investigated by fluorescence spectroscopy. With increasing the temperature of an aqueous solution of P2 and pyrene above the LCST, the peak of 333 nm red-shifted to appear around 339 nm and its intensity increased significantly, indicating the micelle formation. The transfer of pyrene into the micelles was also confirmed by a confocal laser scanning microscope. The fluorescence image obtained from P2 in an aqueous pyrene solution exhibited a green emission resulting from the pyrene transferred into the micelles. Salt effects on the solubility of the copolymers in an aqueous solution were investigated. The LCST of P2 decreased sharply as the concentration of sodium chloride increased, while decreased slowly with potassium chloride.

Characteristics of Developing Turbulent Oscillatory Flows in a 180° Curved Duct with a Square Sectional by using a LDV (LDV에 의한 정사각 단면 180° 곡덕트에서 난류진동유동의 유동특성)

  • Yun, Seok-Ju;Lee, Haeng-Nam;Sohn, Hyun-Chull
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.344-353
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    • 2015
  • In the present study the characteristics of turbulent oscillatory flows in a square-sectional $180^{\circ}$curved duct were investigated experimentally. A series of experiments for air flow were conducted to measure axial velocity profiles, secondary flow velocity profiles and pressure distributions. The measurements were made by a Laser Doppler Velocimeter (LDV) system with a data acquisition and processing system which includes Rotating Machinery Resolve (RMR) and PHASE software. The results from the experiment are summarized as follows. (1) The maximum velocity moved toward the outer wall from the region of a bend angle of $30^{\circ}$. The velocity distribution had a positive value extended over the total phase in the region of a bend angle of $150^{\circ}$. (2) Secondary flows were generally proportional to the velocity of the main flow. The intensity of the secondary flow was about 25% as much as that in the axial direction. (3) Pressure distributions were effects of the oscillatory Dean number and respective region.

Flow Characteristics of a Turbulent Pulsating Flow in a Straight Duct Connected to a Curved Duct by using an LDV (LDV에 의한 곡관 후류에 연결된 직관에서 난류맥동유동의 유동특성)

  • 손현철;이행남;박길문
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.3
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    • pp.177-186
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    • 2003
  • In the present study, the flow characteristics of developing turbulent flows are investigated at the exit region of a square cross-sectional 180" curved duct with dimensions of 40mm$\times$40mm$\times$4000mm (height $\times$ width $\times$length). Smoke particles produced from mosquito coils were used as seed particles for the LDV measurement. Experiments were carried out to measure axial velocity profiles, shear stress distributions and entrance lengths by using an LDV system and Rotating Machinery Resolver RMR with PHASE software. Experimental results clearly show that the time-averaged Reynolds number does not affect oscillatory flow characteristics because the turbulent components tend to balance the oscillatory components in the fully developed flow region. Also, the velocity profiles are in good agreement with 1/7power law such as the results of steady turbulent flows. The turbulent intensity linearly increases along the walls and is slightly higher, especially in the period of deceleration. On the other hand, the LDV measurements show that shear stress values in slightly higher in the period of deceleration due to the flow characteristics in the exit region. The entrance length where flows become stable appears at the point that is 40 times the length of hydraulic diameter.eter.