• Title/Summary/Keyword: photodissociation

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FUV Images and Physical Properties of the OES region

  • Jo, Young-Soo;Min, Kyung-Wook;Seon, Kwang-Il
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.1
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    • pp.69.2-69.2
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    • 2010
  • The far-ultraviolet (FUV) H2 and C IV emission images and spectra of Orion Eridanus Superbubble (OES) is hereby presented. The OES seems to consists of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which find a best suitable parameter such as hydrogen density, gas temperature and incident uv intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^4.5 K~10^6 K. Therefore we could get more clear evidence to reveal the structure of OES. Feature of spectra for the each sub region is also presented and discussed. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

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FUV Images and Physical Properties of the Orion-Eridanus Superbubble region

  • Ko, Young-Soo;Min, Kyoung-Wook;Seon, Kwang-Il
    • The Bulletin of The Korean Astronomical Society
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    • v.35 no.2
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    • pp.71.1-71.1
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    • 2010
  • The far-ultraviolet (FUV) C IV and H2 emission spectra of Orion-Eridanus Superbubble (OES) is hereby presented. The OES seems to consist of multiple phase through the detection of highly-ionized gas and pervasive neutral hydrogen. The former is traced by hot gas while the latter is traced by cold medium. A spectral image made with H2 fluorescent emission shows that the spatial distribution of hydrogen molecule is well correlated with the dust map. The model spectra was taken from a photodissociation region (PDR) radiation code which finds a best suitable parameter such as hydrogen density and intensity of the radiation field. C IV emission is caused by intermediate temperature ISM about 10^5 K. Therefore we could get more clear evidence to reveal the morphology of OES. In this process, the hydrogen density and gas temperature were also estimated. The data were obtained with the Far-Ultraviolet Imaging Spectrograph (FIMS) and the whole data handling were followed by previous FIMS analysis.

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Repairing of a Defective Metallic Line using Laser CVD Deposited Tungsten Film in TFT LCD (레이저 CVD 텅스텐막 증착을 통한 TFT LCD 불량배선 수리)

  • Kim, Sukoon-Koon;Son, Jeong-Seok;Lee, Gi-Sun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.17 no.10
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    • pp.1114-1119
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    • 2004
  • The photodepositioned tungsten film by laser CVD has been carried out the taping test with scotch tape over 10 times. As a result, it exhibited strong adhesion to the under-film such as ITO and SiNx patterned on the LCD substrate. However, it was seriously attacked by alkaline solution used for removing polyimide. And a thickness of laser CVD tungsten film had a close relation to a speed of laser scanning. Also we have improved the success rate of a laser CVD repair with making two pairs of contact hole structure and decreasing laser scanning speed.

Photolysis of Tris(trimethylsilyl)methylsilane in the Presence of 2-Propenol

  • Bu, Bong Hyeon;Hong, Seung Gi;Gang, Seong Gwon
    • Bulletin of the Korean Chemical Society
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    • v.16 no.1
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    • pp.30-33
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    • 1995
  • UV photolysis of the titled polysilane (Me3Si)3SiMe (I) in the presence of a trapping agent of 2-propenol has been performed to investigate the interaction of short-lived silicon species formed from the photolysis of I with 2-propenol. Product studies show that the Me(Me3Si)Si: (II) and (Me3Si)3Si${\cdot}$(III) are primarily formed as the major reactive species which saturate their valencies via O-H insertion and H-abstraction, respectively. Some products are unstable toward further secondary reaction such as photodissociation and intermolecular reaction. The PM3 semiempirical calculations are performed to deduce the energetics of the photoinduced chemical reactions of I with the substrate.

Preparation and Characterization of MgO Doped $Fe_2O_3$ Semiconductive Electrodes for Water Photodissociation

  • Kim, Il-Kwang;Somorjai, Gabor A;Kim, Youn-Geun
    • Bulletin of the Korean Chemical Society
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    • v.12 no.1
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    • pp.13-17
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    • 1991
  • The preparation and characterization of semiconductive electrodes of MgO doped $Fe_2O_3$ were investigated. Pellets of MgO doped $Fe_2O_3$ were sintered at high temperatures between 1300$^{\circ}$C and 1400$^{\circ}$C and quenched rapidly in distilled water. The surfaces were analyzed by X-ray diffraction and scanning Auger electron spectroscopy. The surfaces of pellets contained both corundum structure ($Fe_2O_3$) and spinel structure ($Mg_xFe_{3-x}O_4$). Electrodes made of this material gave comparable anodic and cathodic photocurrents under illumination. The cathodic and anodic photocurrent on these photoelectrodes were verified high at 5-10 wt. percent that is critical doping amounts.

Paeparation and Properties of Epoxy Copolymers Containing Oxime-urethane Groups as Photobase Generators

  • Chae, Gyu Ho;Song, Hye Bong;Seon, Ho Yong;Jang, Ji Yeong
    • Bulletin of the Korean Chemical Society
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    • v.21 no.7
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    • pp.690-696
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    • 2000
  • Epoxy copolymers containing oxime urethane groups were prepared by the polymerization of glycidyl methacrylate and N-[5-(benzophenoneoximinocarbonylamino)pentanyl]maleimide (BOPM). Their physical properties were characterized by GPC, DSC and TGA analyses. Photochemical changes of the copolymers were studied by UV, IR spectroscopy, and contact angle measurements. A photoinduced cross-linking reaction in copolymer films was observed by measuring the insoluble fraction. Irradiation of the copolymers at 254 nm UV light leads to the formation of pendant amino groups by photodissociation of the oxime-urethane groups. Treatment of the amino groups with HCl resulted in the formation of ammonium salts, which changed the polymer surface to be hydrophilic. An insoluble fraction of the copolymers increased with irradiation time, heating time, and heating temperature. Cross-linking of the epoxy resin effectively catalyzed by the photogenerated pendant amines upon heating.

Application of Multichannel Quantum Defect Theory to the Triatomic van der Waals Predissociation Process II

  • 이천우
    • Bulletin of the Korean Chemical Society
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    • v.16 no.10
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    • pp.957-968
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    • 1995
  • Generalized Multichannel Quantum Defect theory (MQDT) was implemented to the vibrational predissociation of triatomic van der Waals molecules in the previous paper [Bull. Korean Chem. Soc, 12, 228 (1991)]. Implementation was limited to the calculation of the scattering matrix. It is now extended to the calculation of the predissociation spectra and the final rotational distribution of the photofragment. The comparison of the results with those obtained by other methods, such as Golden-rule type calculation, infinite order sudden approximation (IOS), and close-coupling method, shows that the implementation is successful despite the fact that transition dipole moments show more energy dependence than other quantum defect parameters. Examination of the short-range channel basis functions shows that they resemble angle-like functions and provide the validity of the IOS approximation. Besides the validity of the latter, only a few angles are found to play the major role in photodissociation. In addition to the implementation of MQDT, more progress in MQDT itself is made and reported here.

Predissociation of the $A^2∑^+$ (v'=4) States of OH:Effects of Multichannel Asymptotic Interactions

  • Lee, Seong Ul
    • Bulletin of the Korean Chemical Society
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    • v.21 no.5
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    • pp.497-502
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    • 2000
  • Quantum mechanical analysis is presented for the photodissociation dynamics of the v'=4 levels of the $A^2Σ^+$ state of the OH molecule. We focus on the effects of the multichannel interactions between the asymptotically degenerate states in the recoupling region to see how they affect the dynamics near the predissociating resonances. Both the scalar (total cross section and branching ratios) and the vector properties (angular distributions and alignment parameters) of O($^3P_j, j=0, 1, 2) are treated. The resonances are predicted to be highly Lorentzian, and the branching ratios do not change much across them. Vector properties, however, show very delicate effects of the multichannel interactions and overlapping near the isolated and overlapping resonances. Computed resonance lifetimes agree reasonably well with experimental results.

CHEMICAL DIAGNOSTICS OF THE MASSIVE STAR CLUSTER-FORMING CLOUD G33.92+0.11. III. 13CN AND DCN

  • Minh, Young Chol;Liu, Hauyu Baobab
    • Journal of The Korean Astronomical Society
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    • v.52 no.3
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    • pp.83-88
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    • 2019
  • Using ALMA observations of the $^{13}CN$ and DCN lines in the massive star-forming region G33.92+0.11A, we investigate the CN/HCN abundance ratio, which serves as a tracer of photodissociation chemistry, over the whole observed region. Even considering the uncertainties in calculating the abundance ratio, we find high ratios (${\gg}1$) in large parts of the source, especially in the outer regions of star-forming clumps A1, A2, and A5. Regions with high CN/HCN ratios coincide with the inflows of accreted gas suggested by Liu et al. (2015). We conclude that we found strong evidence for interaction between the dense gas clumps and the accreted ambient gas which may have sequentially triggered the star formation in these clumps.