• 제목/요약/키워드: excimer fluorescence

검색결과 53건 처리시간 0.024초

레이저 유도 형광법(LIF)을 이용한 층류 메탄 예혼합 화염내 NO 농도측정에 관한 연구 (A Study on Measurement of NO Concentrations in Laminar Premxied $CH_4/O_2/N_2$ Flames by LIF)

  • 김성욱;진성호;김경수;박경석
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 추계학술대회논문집B
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    • pp.156-161
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    • 2000
  • In this study, quantitative nitric oxide concentration distributions are investigated in the post-flame zone of laminar premixed $CH_4/O_2/N_2$, flames by laser-induced fluorescence (LIF). The measurements are taken in flames for different equivalence ratios varying from $0.8{\sim}1.4$, and flow rate is fixed as 5slpm. The NO A-X (0,0) vibrational band around 226 nm is excited using a XeCl excimer-pumped dye laser. Selecting an appropriate NO transition minimizes interferences from Rayleigh scattering and $O_2$ fluorescence. NO concentration is rised when equivalence ratios increase at different vertical distances form nozzle tip. In any case, the maximum NO concentration reaches the maximum in reaction zone.

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레이저 유도 선해리 형광법(LIPE)을 이용한 화염내 OH 및 $O_{2}$ 분자의 2차원 농도 분포 측정 (Planar measurements of OH and $O_{2}$ number density in premixed $C_{3}$H$_{8}$O$_{2}$ flame using laser induced pre-dissociative fluorescence)

  • 진성호;남기중;김회산;장래각;박승환;김웅;박경석;심경훈;김경수
    • 대한기계학회논문집B
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    • 제20권12호
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    • pp.4044-4052
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    • 1996
  • Planar images of OH and $O_{2}$ with tunable KrF excimer laser which has a) 0.5 $cm^{-1}$ / linewidth, b) 0.5 nm tuning range, c) 150 mJ pulse energy, and d) 20 ns pulse width are obtained to determine spatial distributions of OH and $O_{2}$ in premixed $C_{3}$H$_{8}$ /O$_{2}$ flame. The technique is based on planar laser induced pre-dissociative fluorescence(PLIPF) in which collisional quenching is almost avoided because of the fast pre-dissociation. Dispersed LIPF spectra of OH and $O_{2}$ are also measured in a flame in order to confirm the excitation of single vibronic state of OH and $O_{2}$, OH and $O_{2}$ are excited on the P$_{2}$(8) line of the $A^{2}$.SIGMA.$^{+}$(v'= 3)-X$^{2}$.PI.(v'||'||'&'||'||'quot;= 0) band and R(17) line of the Schumann-Runge band B$^{3}$.SIGMA.$_{u}$ $^{[-10]}$ (v'= 0)- X$^{3}$.SIGMA.$_{g}$ $^{[-10]}$ (v'||'||'&'||'||'quot;= 6), respectively. Dispersed OH and $O_{2}$ spectra show an excellent agreement with simulated spectrum and previous works done by other group respectively. It is confirmed that OH widely distributed around flame front area than $O_{2}$.

The Effect of Ethanol on the Physical Properties of Neuronal Membranes

  • Bae, Moon-Kyoung;Jeong, Dong-Keun;Park, No-Soo;Lee, Cheol-Ho;Cho, Bong-Hye;Jang, Hye-Ock;Yun, Il
    • Molecules and Cells
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    • 제19권3호
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    • pp.356-364
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    • 2005
  • Intramolecular excimer formation of 1,3-di(1-pyrenyl) propane(Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to evaluate the effect of ethanol on the rate and range of lateral and rotational mobilities of bulk bilayer structures of synaptosomal plasma membrane vesicles (SPMVs) from the bovine cerebral cortex. Ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMVs. Selective quenching of both DPH and Py-3-Py by trinitrophenyl groups was used to examine the range of transbilayer asymmetric rotational mobility and the rate and range of transbilayer asymmetric lateral mobility of SPMVs. Ethanol increased the rotational and lateral mobility of the outer monolayer more than of the inner one. Thus ethanol has a selective fluidizing effect within the transbilayer domains of the SPMVs. Radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py was used to examine both the effect of ethanol on annular lipid fluidity and protein distribution in the SPMVs. Ethanol increased annular lipid fluidity and also caused membrane proteins to cluster. These effects on neuronal membranes may be responsible for some, though not all, of the general anesthetic actions of ethanol.

국소마취제가 Synaptosomal Plasma Membrane Vesicles의 유동성에 미치는 영향 (Effects of Local Anesthetics on the Fluidity of Synaptosomal Plasma Membrane Vesicles Isolated from Bovine Brain)

  • 윤일;한석규;백승완;김남홍;강정숙;정준기;이은주
    • 대한약리학회지
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    • 제24권1호
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    • pp.43-52
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    • 1988
  • 국소마취제의 약리학적 작용기전을 탐구키 위하여 소의 신선한 대뇌피질로부터 synaptosomal plasma membrane vesicles(SPMV)를 분리한 후 그 소수성 중심부의 microviscosity에 미치는 국소마취제의 영향을 pyrene 형광 probe법으로 측정한 결과 lidocaine HCI과 procaine HCI이 microviscosity를 낮춘다는 것을 알았고 그 정도는 procaine HCI에 비하여 tidocaine.HCI이 더욱 컸다. 또 국소마취 제 가 dimyristoylphosphatidylcholine (DMPC) multilamellar liposomes의 상전 이온도를 낮추며 cooperative unit크기를 감소시킨다는 것도 시차 열량분석법으로 알게 되었다. 상전이온도와 cooperative unit 크기의 감소 정도는 dibucaine HCI>tetracaine HCI>lidocaine HCI > procaine HCI의 순이었다.

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직접 분사식 연료 분무에서의 기.액상 분리 계측에 관한 연구 (An Experimental Study on the Analysis of Liquid/Vapor Phase in GDI Spray)

  • 장석형;김정호;박경석;진성호;김경수
    • 한국분무공학회지
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    • 제5권4호
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    • pp.57-65
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    • 2000
  • For this research an extension of the LIF technique that the LIEF(Laser Induced Exciplex Fluorescence) technique has been used LIEF technique is the unique method to allows the visualization of fuel vapor phase and liquid phase individually by capturing each signals of them. In this work performed that the basic procedure for advanced LIEF technique using TEA and benzene as dopants md high power KrF excimer laser to excite the dopants. Iso-octane is used as the fuel because it does not absorb light at the laser wavelength. The boiling point of benzene and TEA are $81^{\circ}C\;and89^{\circ}C$, respectively, in comparison to $99^{\circ}C$ for iso-octane. It is observed that the behavior and distribution of high pressed fuel injection from various test condition. The injection pressure is set as 3MPa. and 5MPa. And the ambient pressure of test chamber is atmospheric pressure and 1MPa, the ambient temperature of chamber is room temperature, $300^{\circ}C\;and\;500^{\circ}C$ to imitate the condition of GDI engine cylinder.

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나프탈이미도프로필 아크릴레이트와 GMA 공중합체의 합성과 물성 (Synthesis of Naphthalimidopropyl Acrylate and GMA Copolymers and Their Physical Properties)

  • 임덕점;오승민;김부윤;박재경;강인규;서관호;오대희
    • 폴리머
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    • 제38권4호
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    • pp.535-543
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    • 2014
  • 이 논문은 napthalimidopropylacrylate(NIPA)와 glycidylmethacrylate(GMA) 공중합체의 합성과 물성에 관한 연구로서 공중합체의 조성, 단량체 반응성비, 공명효과(Q)와 극성효과(e), 나프탈렌발색단을 가진 물질의 형광특성 등을 조사하였다. Azobisisobutyronitronitryl(AIBN) 개시제와 dimethylformamide(DMF) 용매를 $60^{\circ}C$에서 공중합하였다. 단량체의 반응성비는 Fineman-Ross(F-R), Kelen-$T{\ddot{u}}d{\ddot{o}}s$(K-T) 법으로 단량체 반응성비를 구한바, $r_1$$r_2$보다 크게 나타났다. NIPA이 GMA보다 공중합의 형성이 더 많음을 알 수 있다. 단량체 반응성비의 곱($r_1{\cdot}r_2$)이 1보다 적어서 불규칙한 교대공중합체가 형성되었고 다른 단량체끼리 결합하게 된 교호공중합체를 형성된 것으로 간주된다. 380 nm에서 약한 분자 형광띠와 460 nm에서 강한 중합체 엑시머 형광띠가 나타났다. NIPA 단량체의 형광수명은 실온에서 UV 355 nm 파장에서 형광붕괴커브를 나타냈으며 $5.1449{\times}10^{-7}s$로 나타났다. GMA 공단량체를 아크릴계에 공중합시켜 우수한 내열성 열경화성 접착제나 코팅제에 응용될 것으로 사료된다.

스월형 GDI 엔진의 연소실내 현상에 관한 연구 (A Study on In-cylinder Phenomena in a Swirl Type GDI Engine)

  • 김기성;박상규
    • Journal of Advanced Marine Engineering and Technology
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    • 제26권3호
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    • pp.362-374
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    • 2002
  • For the purpose of development of a GDI engine, the in-cylinder phenomena, such as the spray behaviors, fuel distributions, unburned fuel, and flame characteristics were investigated in a single cylinder GDI engine. The GDI engine was equipped with a swirl type electronic injector and SCV(Swirl Control Valve). PLIF(Planar Laser Induced Fluorescence) system with KrF Excimer laser was used far the measurements of fuel distributions. The effects of the injector specifications, such as the spray cone angle and the offset angle on the in-cylinder phenomena were investigated. As a result, it was found that the injected fuel collided with the bottom of the bowl and moved upward along the exhaust side wall of piston bowl. This fuel vapor played an important role in the instance of spark ignition. The unburned fuel and flame characteristics were greatly influenced by the injector specifications.

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

  • 김성욱;진성호;김경수;박경석
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2001년도 제22회 KOSCI SYMPOSIUM 논문집
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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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스월형 GDI 엔진의 연료분포특성 연구 (Fuel Distribution Characteristics in a Swirl Type GDI Engine)

  • 김기성;박상규
    • 한국마린엔지니어링학회:학술대회논문집
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    • 한국마린엔지니어링학회 2002년도 춘계학술대회논문집
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    • pp.49-59
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    • 2002
  • For the purpose of helping development of a GDI(Gasoline Direct Injection) engine, the spray behaviors and fuel distributions were investigated in a single cylinder GDI engine. The experimental engine is a swirl type GBI engine with a SCV(Swirl Control Valve). PLIF(Planar Laser Induced Fluorescence) system with KrF Excimer laser was used for the measurement of the fuel distributions. The effects of SCV opening angle and the Injector specifications, such as the spray cone angle and the offset an91e on the fuel distributions characteristics were investigated. As a result, it was found that the SCV opening angle had a great effect on the fuel distributions in the late stage of compression process by changing flow fields in the combustion chamber.

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Effect of Drug Substances on the Microviscosity of Lipid Bilayer of Liposomal Membrane

  • Han, Suk-Kyu;Kim, Jin-Suk;Lee, Yong-Soo;Kim, Min
    • Archives of Pharmacal Research
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    • 제13권2호
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    • pp.192-197
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    • 1990
  • The microviscosites of the lipid bilayers of liposomal membranes of phospholipids were measured by the intermolecular excimer, formation method employing pyrene as a fluorescence probe, and the effects of n-alkanols and other local anesthetics on the microviscosity were investigated. The results showed that the n-alkanols and the ohter local anesthetics effectively lowered the microviscosity of the lipid bilayer of the dipalmitoyl phosphatidycholine liposomal membrane in proportion to the concentration of the additives. Moreover, there was a fairly good correlation between the ocal anesthetic activities and the microviscosity-lowering activities of these drugs. This results suggests that the nerve blocking activity of local anesthetics might have some relation with their activity fluidizing the lipid bilayer of biomembrane.

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