• Title/Summary/Keyword: LIF

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A Study on Measurement of NO Concentrations in Laminar Nonpremixed $H_2/N_2$ Flame by LIF (레이저 유도 형광법(LIF)을 이용한 층류 비예혼합 $H_2/N_2$화염에서의 NO 농도측정에 관한 연구)

  • Kim, Sun-Wook;Jin, Seong-Ho;Kim, Gyung-Soo;Park, Kyoung-Suk
    • 한국연소학회:학술대회논문집
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    • 2001.06a
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    • pp.133-138
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    • 2001
  • In this study, quantitative nitric oxide concentration distributions are investigated in the laminar nonpremixed $H_2/N_2$ flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different $N_2$ dilution ratios varying from 20${\sim}$80%, and fuel now rate is fixed as lslpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. We applied same excitation line used in $CH_4$ premixed flame. Overall, NO concentration was rapidly decreased with $N_2$ addition and we could not measure the concentration any longer for $N_2$ dilution above 80%.

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WIND DRIVEN RAIN IMPACT ON A TALL BUILDING FACADE

  • Kim, Jong-Dae;Oh, Jung-Keun;Park, Byong-Keun
    • 한국전산유체공학회:학술대회논문집
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    • 2010.05a
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    • pp.242-246
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    • 2010
  • To determine the trajectories and the impact of rain drops on the facade of a tall building, a particle tracking method is employed form steady state simulation of turbulent flow around the building. The simulation is performed for the upper part of the building comprising a detailed louver system. Rain is trapped at relative high rates on the roof and the penthouse, with Local Intensity Factors (LIF's) of the order of 1. The upper parapets and upper floors get a fair amount of wetting with LIF's of the order of 0.6. The wetting decreases downwards reaching values of 0.2 to 0.25 at the level of the louver system.

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Simultaneous Measurement of Velocity and Concentration Field in a Stirred Mixer Using PIV/LIF Technique (PIV/LIF기법에 의한 교반혼합기 내의 속도장과 농도장 동시 측정)

  • Jeong, Eun-Ho;Yoon, Sang-Youl;Kim, Kyung-Chun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.4
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    • pp.504-510
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    • 2003
  • Simultaneous measurements of turbulent velocity and concentration field in a stirred mixer tank are carried out by using PIV/LIF technique. Instantaneous velocity fields are measured with a 1K$\times$1K CCD camera adopting the frame straddle method while the concentration fields are obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by the second pulse of Nd:Yag laser light. Image distortion due to the camera view-angle is compensated by a mapping function. It is found that the general features of the mixing pattern are quite dependent on the local flow characteristics during the rapid decay of mean concentration. However, the small scale mixing seems to be independent on the local turbulent velocity fluctuation.

Simultaneous Measurement of Velocity and Concentration Field in a Stirred Mixer Using PIV/LIF Techniqueut and POD Analysis (PIV/LIF에 의한 교반혼합기 유동의 난류 속도/농도장 측정 및 POD해석)

  • Jeong Eun-Ho;Yoon Sang-Youl;Kim Kyung-Chun
    • 한국가시화정보학회:학술대회논문집
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    • 2002.11a
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    • pp.101-104
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    • 2002
  • Simultaneous measurement of turbulent velocity and concentration field in a stirred mixer tank is carried out by using PIV/LIF technique. Instantaneous velocity fields are measured by a $1K\times1K$ CCD camera adopting the frame straddle method while the concentration fields are obtained by measuring the fluorescence intensity of Rhodamine B tracer excited by the second pulse of Nd:Yag laser light. Image distortion due to the camera view-angle is compensated by a mapping function. It is found that the general features of the mixing pattern are quite dependent on the local flow characteristics during the rapid decay of mean concentration. However, the small scale mixing seems to be independent on the local turbulent velocity fluctuation.

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The Role of the Endometrium and Embryo in Human Implantation (인간 착상 과정에 자궁내막과 배아의 역할)

  • Jee, Byung-Chul
    • Development and Reproduction
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    • v.13 no.1
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    • pp.1-11
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    • 2009
  • Implantation itself is governed by an array of endocrine, paracrine and autocrine modulators, of embryonic and maternal origin. Window of implantation is the unique temporal and spatial expression of factors allows the embryo to implant via signaling, appositioning, attachment, and invasion in a specific time frame of $2{\sim}4$ days. When the embryo has arrived in the uterine cavity, a preprogrammed sequence of events occurs, which involves the production and secretion of a multitude of biochemical factors such as cytokines, growth factors, and adhesion molecules by the endometrium and the embryo, thus leading to the formation of a receptive endometrium. Cytokines such as LIF, CSF-1, and IL-1 have all been shown to play important roles in the cascade of events that leads to implantation. Integrin, L-selectin ligands, glycodelin, mucin-1, HB-EGF and pinopodes are involved in appositioning and attachment. The embryo also produces cytokines and growth factors (ILs, VEGF) and receptors for endometrial signals such as LIF, CSF-1, IGF and HB-EGF. The immune system and angiogenesis play an important role. The usefulness of these factors to assess endometrial receptivity and to estimate the prognosis for pregnancy in natural and artificial cycles remains to be proven. Integrins, pinopodes, glycodelin and LIF (from biopsies) are promising candidates; from uterine flushings, glycodelin and LIF are also candidates. The ideal serum marker is not available, but VEGF, glycodelin and CSF have some clinical implications. Further evaluation that includes larger groups of infertile women and fertile controls are needed to elucidate whether their presence in plasma, flushing fluid, or endometrial samples can be used as some kind of a screening tool to assess endometrial function and prognosis for pregnancy before and after artificial reproductive therapy. A better understanding of their function in human implantation may lead to therapeutic intervention, thereby improving the success rate in reproduction treatment. New molecular techniques are becoming available for measuring both embryonic and endometrial changes prior to and during implantation. The use of predictive sets of markers may prove to be more reliable than a single marker. Ultimately, the aim is to use these tools to increase implantation in artificial cycles and consequently improve live-birth rates.

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A Study on Spectra of Laser Induced Flourescence in Phantom of N-propyl-N,N-dimethylethanolamine (N-propyl-N,N-dimethylethanolamine의 Phantom에서 Laser Induced Fluorescence의 스펙트라에 관한 연구)

  • Kim, Ki-Jun;Lee, Joo-Ho;Lee, Joo-Youb;Sung, Wan-Mo
    • Journal of the Korean Applied Science and Technology
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    • v.32 no.2
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    • pp.330-338
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    • 2015
  • The influences of fluorescence, scattering, and flocculation in turbid material by light scattering of N-propyl-N,N-dimethylethanolamine, fluorescence agent and absorption agent were interpreted for the scattered fluorescence intensity and wavelength. They have been studied the molecular properties by the spectroscopy of laser induced fluorescence (LIF) and flocculation. 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 values of scattering coefficient ${\mu}_s$ are large by means of the increasing scattering of scatterer, The values have been found that the slope decays exponentially as a function of concentration from laser source to detector by our experimental result. It may also aid in designing the best model for oil chemistry, bio-pharmaceutical, laser medicine and application of medical engineering on LIF and coagulation in particle transport mode.

Soot formation in Counterflow diffusion of ethylene/propane mixtures (에틸렌/프로판 대향류 확산화염에서 매연생성특성에 대한 실험적 연구)

  • Yoon, S.S.;Lee, S.M.;Hwang, J.Y.;Chung, S.H.
    • 한국연소학회:학술대회논문집
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    • 2000.12a
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    • pp.229-235
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    • 2000
  • Soot formation characteristics in counterflow diffusion flames of ethylene/propane/nitrogen mixtures have been studied experimentally to investigate the soot formation mechanism. The effect of HACA reaction on PAH and soot growth has been experimentally investigated by using 2-D planar LII and PAH LIF techniques.

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A Study on the Measurements of Beam Wave Propagation and Fluorescence Spectroscopy in Particles Media (입자매질에서 빔파동전파와 형광분광 측정에 관한 연구)

  • Kim, Ki-Jun;Lee, Jou-Youb;Sung, Wan-Mo
    • Journal of the Korean Applied Science and Technology
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    • v.31 no.2
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    • pp.167-175
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    • 2014
  • The influences of fluorescence, scattering, and flocculation in turbid material 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 in Photodynamic therapy. The interactions of several colloid particles can come into play which have major effect on the flocculation and LIF process. We measured scattering and fluorescence spectra of the sample for in vitro as function of concentration from lase source to detector. The value of scattering coefficient ${\mu}_s$ is large by means of the increasing particles of scatterer. Therefore, Phorphyrin A is larger than Phorphyrin C in scattering intensity ${\mu}_s$, but Phorphyrin A is smaller than Phorphyrin C in penetration depth ${\delta}$.

Modulation of Cellular Immune Response by Inosiplex (Inosiplex에 의한 세포성 면역반응의 변화)

  • Lee, Hern-Ku;Lee, Jeong-Ho;Kim, Hak-Kun;Ha, Tai-You
    • The Journal of the Korean Society for Microbiology
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    • v.21 no.2
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    • pp.251-259
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    • 1986
  • This study was performed to assess the effect of inosiplex(ISP) on the resistance of mice Candida albicans infection, the migration of chicken leukocytes, the production of leukocyte migration inhibitory factor(LIF), and the cell-mediated immunity(CMI) to lepomin in multibacillary lepromatous leprosy patients. The treatment with ISP before or on the time of infection with C. albicans had no or deliterious effect, and treatment with ISP after infection had no effect on the recovery of C. albicans from the kidneys of mice. The migratory ability of chicken leukocytes and the production of LIF from splenocytes of mice were not affected by ISP treatment. However, ISP decreased the migration of chicken leukocytes in vitro, and this decrease was dose-dependent. The therapy of lepromatous leprosy patients with ISP for 10 or 30 days clearly showed the increase of the significant positive rate of Mitsuda skin test to lepromin. The immune recovery as a result of the therapy was found to be the best in the group of patients treated for 30 days. This results suggest that (1) the effect of ISP in renal candidiasis can vary depending on the time of treatment relative to infection, (2) ISP can primarily change the migratory ability of chicken leukocytes but does not affect the production of LIF in mice, and (3) the classical therapy combined with ISP can reinforce or restore the defences of lepromatous leprosy patients against Mycobacterium leprae.

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