• 제목/요약/키워드: LIF

검색결과 224건 처리시간 0.034초

The analysis of neutral particle in Mercury discharge lamp

  • Yang, Jong-Kyung;Lee, Jong-Chan;Choi, Yong-Sung;Park, Dae-Hee
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 C
    • /
    • pp.2421-2423
    • /
    • 2005
  • In this paper, we introduced a LIF measurement method and summarized the theoretical side. When an altered wavelength of laser and electric power, lamp applied electric power, we measured the relative density of the metastable state in mercury after observing a laser induced fluorescence signal of 404.8nm and 546.2nm, and confirmed the horizontal distribution of plasma density in the discharge lamp. The results confirmed the resonance phenomenon regarding the energy level of atoms along a wavelength change, and also confirmed that the largest fluorescent signal in 436nm, and that the density of atoms in 546.2nm $(6^3S_1{\rightarrow }6^3P_2)$ were larger than 404.8nm $(6^3S_1{\rightarrow}6^3P_1)$. According to the increase of lamp applied electric power, plasma density increased, too. When increased with laser electric power, the LIF signal reached a saturation state in more than 2.6mJ. When partial plasma density distribution along a horizontal axis was measured using the laser induced fluorescence method, the density decreased by recombination away from the center.

  • PDF

The optical analysis of discharge lamp by Laser

  • Yang, Jong-Kyung;Lee, Jong-Chan;Choi, Yong-Sung;Park, Dae-Hee
    • 한국전기전자재료학회:학술대회논문집
    • /
    • 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
    • /
    • pp.570-571
    • /
    • 2005
  • In this paper, we introduced a LIF measurement method and summarized the theoretical side. When an altered wavelength of laser and electric power, lamp applied electric power, we measured the relative density of the metastable state in mercury after observing a laser induced fluorescence signal of 404.8nm and 546.2nm, and confirmed the horizontal distribution of plasma density in the discharge lamp. The results confirmed the resonance phenomenon regarding the energy level of atoms along a wavelength change, and also confirmed that the largest fluorescent signal in 436nm, and that the density of atoms in 546.2nm ($6^3S_1\rightarrow6^3P_2$) were larger than 404.8nm ($6^3S_1\rightarrow6^3P_1$). According to the increase of lamp applied electric power, plasma density increased, too. When increased with laser electric power, the L1F signal reached a saturation state in more than 2.6mJ. When partial plasma density distribution along a horizontal axis was measured using the laser induced fluorescence method, the density decreased by recombination away from the center.

  • PDF

Depletion Kinetics of Ground State FeO Molecules by $O_2, N_2O, and \;N_2$

  • Son, H. S.
    • Bulletin of the Korean Chemical Society
    • /
    • 제21권6호
    • /
    • pp.583-587
    • /
    • 2000
  • Depletion kinetics of ground state FeO molecules by $0_2$, $N_2O$ and $N_2$ has been studied at room temperature. The ground state FeO molecules were generated by photolysis of a $Fe$(CO)_5$/M(O_2$, $N_2O)/He$ mixture using an unfocused weak UV laser beam. The formation of ground state FeO molecules was identified by a laser-induced fluorescence (LIF) method. The intensity distribution of those undisturbed rotational lines suggests that the rotational temperature of the ground state FeO molecules is lower than room temperature. The LIF intensities of FeO molecules at different partial pressures of $0_2$, $N_2O$ and $N_2$ were monitored as a function of the time delay between the photolysis and probe laser pulses to obtain the depletion rate constants for the ground state FeO. They were 1.7+ 0.2x $10^{-12}$, 4.8 $\pm0.4$ x $10^{-12}$, and $1.4\pm$ 0.2x $10^{-12}cm^3$molecule^{-1}s^{-1}$$ by $0_2$, $N_20$, and $N_2$, respectively.

목단피에 의한 임신 저해의 분자적 기전에 대한 연구 (Mechanism Study on Inhibition of Pregnancy by Root Barks of Paeonia suffruticosa)

  • 최희정;김은영;최희진;박미주;정태욱;박성하;김소연;하기태
    • 동의생리병리학회지
    • /
    • 제28권5호
    • /
    • pp.530-536
    • /
    • 2014
  • Root barks of Paeonia suffruticosa Andrews (PS) was reported as contraindicated drugs of pregnancy by many Korean medical classics. Recently, a major ingredient component of PS, paeonol was reported that has contraceptive effect on early pregnancy in rats. However, the accurate molecular mechanism is not clear. In this study, we showed that PS decreased the expression of receptor for leukemia inhibitory factor (LIFR) in human endometrial Ishikawa cells at non-toxic dose, although the expression of leukemia inhibitory factor (LIF) was increased by PS. In addition, PS inhibited the adhesion of human trophoblastic JAR cells onto Ishikawa cells. Given importance of LIF-LIFR signaling pathway in the process of embryo implantation, the decreased LIFR expression by PS will be a good explanation on the PS- or its ingredient compounds-induced contraception.

난포자극호르몬이 인간의 자궁 기질세포의 유전자 발현 양상에 미치는 영향 (Alteration of Gene Expressions in Human Endometrial Stromal Cells by Exogeneous FSH Treatments)

  • 최혜원;전진현;이형송;홍인선;강경선;궁미경
    • Clinical and Experimental Reproductive Medicine
    • /
    • 제31권4호
    • /
    • pp.217-223
    • /
    • 2004
  • Objective: To evaluate the effects of recombinant FSH (rFSH) and urinary FSH (uFSH) on the gene expressions of human endometrial stromal cells in vitro. Methods: Endometrial tissue was obtained from a pre-menopausal women undergoing hysterectomy. Primary endometrial stromal cells were isolated and in vitro cultured with FBS-free DMEM/F-12 containing 0, 10, 100, and 1, 000 mIU/ml of rFSH and uFSH for 48 hours, respectively. Total RNA was extracted from the cultured cells and subjected to real time RT-PCR for the quantitative analysis of progesterone receptor (PR), estrogen receptor $\alpha/\beta$ (ER-$\alpha/\beta$), cyclooxygenase 2 (Cox-2), leukemia inhibitory factor (LIF), homeobox A10-1 and -2 (HoxA10-1/-2). Results: Both hormone treatments slightly increased (< 3 folds) the expressions of PR, ER-$\beta$ and HoxA10-1/-2 gene. However, ER-$\alpha$ expression was increased up to five folds by treatments of both FSH for 48 hours. The LIF expression by the 10 mIU/ml of uFSH for 12 hours was significantly higher than that of rFSH (p<0.01). After 24 hours treatment of two kinds of hormones, the expression patterns of LIF were similar. The 100 and 1, 000 mIU/ml of rFSH induced significantly higher amount of Cox-2 expression than those of uFSH, respectively (p<0.05). Conclusion: This study represents no adversely effect of exogeneous gonadotropins, rFSH and uFSH, on the expression of implantation related genes. We suggest that rFSH is applicable for the assisted reproductive technology without any concern on the endometrial receptivity.

BCF1 생쥐 배반포기 유래 배아간세포 작성에 관한 연구 (Maintenance and Differentiation of Pluripotential Embryonic Cell Lines from Mouse Blastocysts)

  • 이재원;이훈택;정길생
    • 한국가축번식학회지
    • /
    • 제18권4호
    • /
    • pp.235-244
    • /
    • 1995
  • 생쥐 배반포기 내부세포괴를 체외에서 분리 배양하여 분화가 억제된 내부세포괴 유래 증식세포를 미분화 상태에서 무한히 증식할 수 있는 전능성을 지닌 배아간세포(embryonic stem cell : ES cell)로 확립하고자 본 연구를 실시하였다. BCF1 생쥐 배반포를 10% FCS, 0.1mM nonessential amino acid, 0.1mM sodium pyruvate, 0.1mM 2-mercaptoethanol과 1,000U/ml LIF(세포분확억제인자)가 첨가된 DMEM 기초배양액에 mitomycin-C를 처리한 STO 단층배양세포에서 배양하여 분화가 억제된 내부세포괴 유래의 배아간세포를 분리하였다. 배반포를 STO 단층배양세포에서 4일간 배양하여 내부세포괴세포를 신선한 STO 단층배양세포에서 약 5일 간격으로 반복하여 계대배양을 실시하였다. 5차 계대배양후 뚜렷한 분화 양상없이 배양된 미분화 세포군에 대한 alkaline phosphatase (AP)염색과 체외분화능 검색을 실시한 결과 적색의 미분화 AP 양성반응이 확인되었으며 체외에서 배분화 형성이 유도됨에 따라 배양된 배아간세포주의 다능성 배아간세포 특성을 확인할 수 있었다.

  • PDF

Laser-Induced Fluorescence spectroscopy을 이용한 환경 중 PAHs 화합물의 실시간 현지 모니터링 (In-situ Monitoring of PAHs in the Environment Using Laser-Induced Fluorescence Spectroscopy)

  • 이철규;;김영준
    • 한국대기환경학회:학술대회논문집
    • /
    • 한국대기환경학회 2001년도 추계학술대회 논문집
    • /
    • pp.358-359
    • /
    • 2001
  • PAHs는 불완전연소 과정과 주유소나 타르 생산공장 주변에서 발생하는데 돌연변이와 발암의 잠재력으로 인하여 특별한 관심이 요구되는 것들이고 US-EPA에서도 우선 오염물질로 선정되었다. PAHs를 검출하는 훌륭한 기술들이 존재하나, 이러한 기술들은 연속적인 모니터링이 요구되거나 많은 수의 샘플을 분석해야할 경우에 상당한 양의 비용과 시간이 요구된다. 그러나 분광학 기술을 바탕으로 한 Laser-Induced Fluorescence(LIF) spectroscopy를 이용한 방법은 실시간으로 연속적인 측정을 가능하게 할 뿐 아니라 여러 가지 PAHs, 유류오염물질 등의 물질을 동시에 측정할 수 있다. (중략)

  • PDF

레이저 진단기법을 이용한 연소 가시화 기술 (Visualization of Combustion by Using Laser Diagnostic Techniques)

  • 정석호;원상희
    • 한국가시화정보학회지
    • /
    • 제2권1호
    • /
    • pp.52-56
    • /
    • 2004
  • Several visualization techniques of laser diagnostics are presented for combustion phenomena, including Mie scattering for flow, Rayleigh and Raman scattering spectroscopy for major species, laser-induced fluorescence for minor species, and laser-induced incandescence for soot. These techniques have been applied to understand the various combustion phenomena more clearly, including buoyancy-dominant flow system, diffusion flam oscillation, laminar and turbulent lifted flames, flame propagation along a vortex ring, and soot zone characteristics. The usefulness of laser diagnostics on a better understanding of physical mechanism is demonstrated.

  • PDF