• KSBB Journal
• /
• 제22권1호
• /
• pp.48-52
• /
• 2007

본 연구에서는 sonificator를 장착하여 세포막을 파쇄하고 현장에서 형광을 이용하여 조작이 간편하고 단시간에 DNA와 단백질을 동시에 측정할 수 있는 자동화된 형광기를 개발하기 위하여 단백질을 측정하는데 최적의 파쇄조건을 확립하고자 하였다. 용액 중에 녹아 있는 공기 중의 oxygen은 collisional quenching을 일으키는데 sonification이나 가열처리를 시키면 oxygen이 제거되어 quenching 효과가 크게 감소되어 높은 형광값을 나타내었다. 0.7 X 이상의 형광시약 농도에서는 반응시작 후 1분 이내에 측정해야 하며, 0.3 X 이하의 형광시약 농도에서는 반응시작 후 2$\sim$3분 사이에 반응을 시킨 후 측정하는 것이 바람직한 것으로 나타났다. $100{\mu}g/m{\ell}$ 이상의 BSA 농도에서는 형광시약이 포화되었으며, 시료를 sonification시키면 단백질이 변성되어 눈에 보일 정도로 불투명해져서 시료 용액의 불투명도로 인해 형광 값이 감소되는 경향을 나타내었으며, $1{\mu}g/m{\ell}$ 이하의 BSA 시료에서는 sonification을 시키지 않은 시료보다 sonification을 시켰을 때 $0.125{\mu}g/m{\ell}$의 BSA를 훨씬 더 구분이 잘 되어 낮은 단백질 농도에서는 sonification시키는 것이 훨씬 유리한 것으로 나타났다.

• Journal of Photoscience
• /
• 제4권3호
• /
• pp.97-103
• /
• 1997

The effect of temperature on the fluorescence quenching of 2-(4-Methoxyphenyl)-5-(1-naphthyl)-1,3,4-oxadiazole (MPNO1), 2-(4-Methoxyphenyl)-5-(2-naphthyl)-1,3,4-oxadiazote(MPNO2), by aniline, and 2-Phenylindole (2-PI) by CCk, in toluene by steady state method and in benzene by time-resolved method have been carried out in the temperature range 30 - 70$\circ$C. The Stem-Volmer (S-V) plots, I$_0$/I against quencher concentration [Q] at different temperanares show positive deviations. The fluorescence lifetimes determined at different temperatures show no systematic variations and the variations being within the experimental error, the average values of lifetimes $ $\tau$ (t) are taken for further calculations. Rate constants such as Stem-Volmer quenching constants K$_sv}$, quenching rate parameters k$_q$ and k'$_q$, static quenching constant V and kinetic distance r are determined using the modified Stem-Volmer equation and sphere of action static quenching model. In order to see whether the reactions are diffusion limited, equations k$_q$ = e$^{-Eq/RT}$ and k'$_q$ = e$^{-Eq/RT}$ are used to determine the values of E$_q$ and E'$_q$, the activation energies for collisional quenching and the values of E$_q$ are 14.53. 17.28 and 16.20 kJ mole$^{-1}$ for MPNO1, MPNO2 and 2-PI respectively and the values of E'$_q$ are 14.62 and 17.73 for MPNO1 and MPNO2 respectively. From the magnitudes of various quantities it has been concluded that the reactions are diffusion limited and the observed positive deviations in the S-V plot are due to static and dynamic quenching.

• 한국염색가공학회지
• /
• 제13권6호
• /
• pp.33-33
• /
• 2001

The physical properties and the dyeability of the easily dyeable polyester yarn(EDY) were investigated and compared with those of regular polyester (REG-PET). The EDY, copolymerized with small amount of polyethylene glycol(PEG), showed higher intensity of aliphatic CH peak in IR spectrum, lower density and lower compactness than those of the REG-PET from the analysis of IR, density gradient column and XRD respectively. In the physical properties, the EDY has lowers $T_g,\;T_m$, specific stress and initial modulus, and also has higher strain than that of the REG-PET. The EDY can be dyed under atmospheric pressure and its dyeing rate was faster than REG-PET due to low $T_d$, and this seems to be caused by the increased flexibility of Polymer chain in amorphous region of the EDY due to the copolymerization of PEG.ns being within the experimental error, the average values of lifetim.
$\tau$(t) are taken for further calculations. Rate constants such as Stern-Volmer quenching constants K$_{sv}$, quenching rate parameters k$_q$ and k''$_q$, static quenching constant V and kinetic distance r are determined using the modified Stern-Volmer eq.
tion and sphere of action static quenching model. In order to see whether the reactions are diffusion limited, equations k$_q$ = e$^{-Eq/RT}$ and k''$_q$ = e$^{-Eq/RT}$ are used to determine the values of E$_q$ and E''$_q$, the activati.
energies for collisional quenching and the values of E$_q$ are 14.53, 17.28 and 16.20 kJ mole$^{-1}$ for MPNO1, MPNO2 and 2-PI respectively and the values of E''$_q$ are 14.62 and 17.73 for MPNO1 and MPNO2 respectively. From the magnitudes of various quantities it has.
een concluded that the reactions are diffusion limited and the observed positive deviations in the S-V plot are due to static and dynamic quenching.

• 대한기계학회논문집B
• /
• 제20권12호
• /
• pp.4044-4052
• /
• 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 $O_{2}$.

• Bulletin of the Korean Chemical Society
• /
• 제17권1호
• /
• pp.56-60
• /
• 1996

The pressure saturation effect on the phosphorescence decay rates of the $^3B_1$ State of $SO_2$ has been reinvestigated by the laser induced phosphorescence method in pure $SO_2$. We have attempted to fit the pressure dependence of the phosphorescence decay rates using the radiationless transition model by introducing different coupling constants for each vibrational level ofthe 3B1 state. The experimental decay rates can be fitted well, when the coupling constants for the (0,0,0), (0,1,0) and (0,2,0) levels of the $^3B_1$ state are $7.2\;{\times}\;10^{-4}$, $2.2\;{\times}\;10^{-3}$ and $5.9\;{\times}\;10^{-3}\;cm^{-1}$, respectively.

• 한국자동차공학회논문집
• /
• 제2권4호
• /
• pp.91-99
• /
• 1994

Tunable KrF Excimer Laser is used here for measuring OH and $O_2$ density distribustion in an open $H_2$/air premixed flame and in a combustion bomb. Laser Rayleigh Scattering(LRS) and Planar Laser Induced Predissociative Fluorescence(PLIPF) methods are used to obtain two-dimensional images of total and specific densities. Laser Excitation wavelengths are calibrated via flame images and combustion bomb images show good qualitative a greement with theoretical calculation. Furthermore images in a combustion bomb can be developed to study real Spark-Ignition engine combustions. Our experimental images show that there are no more collisional quenching problem at high pressure environment(including atmospheric pressure) using predissociative fluorescence technique. Further development to obtain two-dimensional temperature dustribution is ready to use eventhough it is not reported in this paper.

• 한국재료학회지
• /
• 제21권10호
• /
• pp.532-541
• /
• 2011

The Xe plasma flat lamp, considered to be a new eco-friendly LCD backlight, requires a further improvement of its luminance and luminous efficiency. To improve the performance of this type of lamp, it is necessary to understand the effects of the discharge variables on the luminous characteristics of the lamp. In this study, the luminous characteristics of a coplanartype Xe plasma flat lamp with a teeth-type electrode pattern were analyzed while varying the gas composition, gas pressure and input voltage. The effects of the phosphor layer on the discharge and the luminous characteristics of the lamp were also studied. The luminous efficiency of the coplanar-type Xe plasma flat lamp improved as the Xe input ratio and gas pressure increased. Higher luminous efficiency was also obtained when helium (He) was used as a buffer gas and when a phosphor layer was fabricated on the electrode region. In contrast, the luminous efficiency was reduced with increasing the input voltage. It was found that the infrared emissions from the lamp were affected by the Xe excitation rate in the plasma, the Xe gas density, the collisional quenching of excited Xe species by gas molecules, and the recombination rate between the Xe ions and electrons.

• Bulletin of the Korean Chemical Society
• /
• 제25권2호
• /
• pp.226-232
• /
• 2004

Ground and low-lying electronic states of Cr atoms in the gas phase were generated from photolysis of $Cr(CO)_6$ vapor in He or Ar using an unfocussed weak UV laser pulse and their reactions with $O_2$ and $N_2O$ were studied. When 0.5-1.0 Torr of $Cr(CO)_6$ /$O_2$ /He or Ar mixtures were photolyzed using 295-300 nm laser pulses, broadband chemiluminescence peaked at ~420 and ~500 nm, respectively, was observed in addition to the atomic emissions from $z^7P^{\circ}$, $z^5P^{\circ}$, and $y^7P^{\circ}$ states of Cr atoms. When $N_2O$ was used instead of $O_2$, no chemiluminescence was observed. The chemiluminescence intensities as well as the LIF intensities for those three low-lying electronic states ($a^7S_3,\;a^5S_2\;and\;a^5D_J$) showed second-order dependence on the photolysis laser power. Also, the chemiluminescence intensities were first-order in $O_2$ pressure, but the presence of excess Ar showed a strong inhibition effect on them. Based on the experimental results, the chemiluminecent species in this work is attributed to $CrO_2^*$ generated from hot ground state Cr atoms with $O_2$. The apparent radiative lifetimes of the chemiluminescent species and collisional quenching rate constants by $O_2$ and Ar also were investigated.

• 한국수소및신에너지학회논문집
• /
• 제13권3호
• /
• pp.169-180
• /
• 2002

Rayleigh scattering and laser induced predissociative fluorescence are used to obtain two-dimensional images of temperature and species concentration in a laminar non-premixed flame of a diluted hydrogen jet. Rayleigh scattering cross-sections are experimentally obtained at 248nm. Planar images of OH and $O_2$ with tunable KrF excimer laser which has a) $0.5cm^{-1}$ linewidth, b) 0.5nm tuning range, c) 150mJ pulse energy, and d) 20ns pulse width are obtained to determine spatial distributions of OH and $O_2$. The technique is based on planar laser induced predissociative fluorescence (PLIPF) in which collisional quenching is almost avoided because of the fast predissociation. 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) and $Q_1$(11) line of the $A^2{\Sigma}^{+}({\nu}^{'}=3)-X^{2}{\Pi}({\nu}^{''}=o)$ band and R(17) line of the Schumann-Runge band $B^{3}{\Sigma}_{u}{^-}(\nu^{'}=0)-X^{3}{\Sigma}_{g}{^-}({\nu}^{''}=6)$, respectively. Fluorescence spectra of OH and Hot $O_2$ are captured and two-dimensional images of the hydrogen flame field are successfully visualized.