• Journal of the Korean Ceramic Society
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• v.35 no.7
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• pp.757-763
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• 1998

The effect of {{{{ {Ga }^{3+ } }} addition on the photoluminescence and cathodoluminescence of {{{{ {SrTiO}_{3 } }}:{{{{ { Pr}^{3+ } }} was stu-died by performing the excitation emission and decay time measurements. Addition of {{{{ {Ga }^{3+ } }} in {{{{ {SrTiO}_{3 } }}:{{{{ { Pr}^{3+ } }} resulted in a considerable enhancement of {{{{ { Pr}^{3+ } }} emission intensity. From the analysis of the experimental results the following mechanism is proposed. Excitation in the {{{{ {SrTiO}_{3 } }} host lattice leads to the formation of electrons in the conduction band and holes in the valence band. The electrons in the conduction band re-combine radiatively with the holes trapped at {{{{ { Ga}^{3+ } }} and the energy is transferred to {{{{ { Pr}^{3+ } }} ion which give its own characteristic red emission.

• Bulletin of the Korean Chemical Society
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• v.17 no.7
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• pp.637-642
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• 1996

Preparation and properties of potential CVD (Chemical Vapor Deposition) precursors for the TiO2, a major component of the perovskite materials such as PT, PLT, PZT, and PLZT were investigated. Reactions between β-diketones and TiMe3, formed in situ failed to produce stable Ti(β-diketonate)3 complexes but a stable purple solid, characterized as (OTi(BPP)2)2 (BPP=1,3-biphenyl-1,3-propanedione) was obtained when BPP was used. Several new Ti(Oi-Pr)2(β-diketonate)2 complexes with aromatic or ring substituents were synthesized by the substitution reaction of Ti(OiPr)4by β-diketones and characterized with 1H NMR, IR, ICP, and TGA. Solid complexes such as Ti(Oi-Pr)2(BAC)2 (BAC=1.-phenyl-2,4-pentanedione), Ti(Oi-Pr)2(BPP)2, Ti(Oi-Pr)2(1-HAN)2 (1-HAN=2-hydroxy-1-acetonaphthone), Ti(Oi-Pr)2(2-HAN)2 (2-HAN=1-hydroxy-2-acetonaphthone), Ti(Oi-Pr)2(ACCP)2 (ACCP=2-acetylcyclopentanone), and Ti(Oi-Pr)2(HBP)2 (HBP=2-hydroxybenzophenone) were found to be stable toward moisture and air. Ti(Oi-Pr)2(ACCP)2 and Ti(Oi-Pr)2(HBP)2 were proved to have lower melting points and higher decomposition temperatures. However, these complexes are thermally stable and pyrolysis under an inert atmosphere resulted in incomplete decomposition. Ti(Oi-Pr)2(DPM)2 (DPM=dipivaloylmethane) and Ti(Oi-Pr)2(HFAA)2 (HFAA=hexafluoroacetylacetone) were sublimed substantially during the thermal decomposition. Pyrolysis mechanism of these complexes are dependent on type of β-diketone but removal of Oi-Pr ligands occurs before the decomposition of β-diketonate ligands.

• Journal of the Korean Ceramic Society
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• v.39 no.11
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• pp.1023-1027
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• 2002

In this paper, we have prepared phase-pure $SrTiO_3:\;Pr^{3+}$ phosphor powder by Supercritical Fluid Mixing using $Sr(OH)_2{\cdot}8H_2O$ and $TiO_2$ powders as starting materials. Its luminescent properties were investigated in comparison with $SrTiO_3:\;Pr^{3+}$ powders prepared by solid-state method with conventional mixing. $SrTiO_3:\;Pr^{3+}$ phosphor powders by Supercritical Fluid Mixing have spherical shapes and narrow particle size distribution. We have investigated the luminescent properties of $SrTiO_3:\;Pr^{3+}$ phosphor using $Al^{3+}$ and $Ga^{3+}$ as sensitizer.

• Journal of Korea Water Resources Association
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• v.36 no.4
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• pp.647-659
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• 2003

The purpose of this study is to evaluate hydrological applicability of spatially observed rainfall distribution data by the TRMM/PR (Tropical Rainfall Measuring Mission / Precipitation Radar). For this study, firstly, TRMM/PR data (Y) of the Yongdam-Dam Watershed (930.38$km^2$) was extracted and secondly, TRMM/PR data and the rainfall data (X) by AWS (Automatic Weather Station) were compared by executing a correlation analysis. As a result, the regression equations were deduced as two parts (under 60mm/day : Y = 18.55X-0.53, over 60mm/day : Y = 3.11X+51.16). SCS runoff analysis was conducted using 7 rainfall events in 1999 for Yongdam-Dam watershed and the Cheon-Cheon subwatershed for the revised TRMM/PR data. TRMM/PR data showed relative errors ranging from 19.6％ ti 45.6％, and from 11.3％ to 38.9％ for Cheon-Cheon subwatershed and Yongdam-Dam watershed, respectively, AWS data showed relative errors ranging from 0.5％ to 12.8％, and from -1.6％ to -10.3％, for Cheon-Cheon subwatershed and Yongdam-Dam watershed, respectively. Futher researches are necessary to evaluate the relationship between TRMM/PR data and AWS data for practical hydrological applications.

• Journal of Acupuncture Research
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• v.22 no.6
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• pp.1-15
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• 2005

Objectives : The aim of this study was to investigate the effect of Peucedani Radix herbal acupuncture(PR-HA) at St36(joksamni) on ovalbumin-induced asthma in mice. Methods : C57BL/6 mice were sensitized and challenged with OVA(ovalbumin) for 12 weeks(once a week) C57BL/6 mice were injected, inhaled and sprayed with OVA for 12 weeks (3times a week). One of the two experimental groups was just treated with needle-prick on St36 and the other group was treated with 1% concentrations of PR-HAS at St36, for the later 8 weeks (3times /week). Results : 1. The weight and total cells of lung of the mice group treated with PR-HA decreased significantly compared with those of control group. 2. Total Leukocytes and Eosinophils in BALF of the mice group treated with PR-HA decreased significantly compared with those of control group. 3. Eosinophils in BALF of the mice group treated with PR-HA in Photomicrographs decreased significantly compared with those of control group. 4. According to Histological analysis of lung sections, it decreased significantly adhension of collagen in PR-HA than those of control group 5. The concentration of IgE, IL-4, IL-5, in BALF and IL-4, IL-5, Il-13 in serum of the mice group treated with PR-HA decreased significantly compared with that of control group. 6. The number of Gr-1+/CD11b+, CD11b+, CD3-/CCR3+, CD4+, CD3e+/CD69+ , CD23+B220+ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. 7. The cytokine's manifestation of mRNA of the mice group treated with PR-HA with RT-PCR decreased significantly compared with that of control group. Conclusion : We conclude that PR-HA is effective on OVA-induced asthma of C57BL/6 mouse.

• Journal of the Korean Ceramic Society
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• v.29 no.11
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• pp.851-854
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• 1992

It was grown ZrO2:10 mol% Y2O3 single crystals doped with 1 wt% of rare earth metal ion (Ce, Pr, Nd, Er, Eu) by Skull Method. Grown crystals showed Ce:orange-red, Pr:golden-yellow, Nd:lilac, Er:pink, Eu:light pink due to dopant effect. It was examined color centers in light absorption pattern of visible region (λ= 300~700 nm); in as grown samples, absorption by Ce4+, (Pr4+, Pr3+), Nd3+, Er3+, Eu3+ ions were important, and in samples after vacuum annealing, decrease of absorption by Pr4+ ion and increase of absorption by Pr3+ ion was important, and absorption by Ce3+, Eu2+ was important due to reduction of activator.

• Analytical Science and Technology
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• v.8 no.2
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• pp.125-129
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• 1995

The energy transfer is observed in double-activator-doped LaOCl:Pr, Tb and LaOCl:Pr, Eu system. From laser excitation and fluorescence spectra, a peculiar process for energy transfer between the activators is found. The energy absorbed by $Tb^{3+}$ is directly transferred to $Pr^{3+}$ ion. A cascade relaxation of an excited $Pr^{3+}$ level to lower level, $^1D_2$ is induced by $Eu^{3+}$, $Tb^{3+}$, which has $^7F_J$ ground levels like $Eu^{3+}$ ion, does not affect the cascade relaxation. The result represents that the quantum state of ion is not absolute condition for the energy transfer and that the energy transfer is competitive between levels of activator when the activator ions are closely located.

• Journal of Acupuncture Research
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• v.22 no.6
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• pp.61-74
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• 2005

Objectives : The aim of this study was to investigate the effect of Asthma-depression and Immunoregulation with PR-HAS(Herbal-acupuncture with Platycodi Radix infusion solution) injection at Joksamni(St36) on ovalbumin-induced asthma in mice. Methods : C57BL/6 mice were sensitized and challenged with OVA(ovalbumin) for 12 weeks(once a week). The experimental group(OVA-PR-HA) wase treated with concentrations(1%) of PR-HAS at Joksamni(St36) for the later 8 weeks(3times/week). The second experimental group(OVA-Needle prick) was treated with Needle-Prick at Joksamni(St36) for the later 8 weeks(3times/week). Results : 1. The weight and total cells in the mice lung treated with PR-HA decreased significantly compared with that of control group. 2. Total leukocytes and eosinophils in BALF of the mice group treated with PR-HA decreased remarkably compared with those of control group. 3. The sticking of collagen on histological analysis of lung sections, the mice group treated with PR-HA decreased significantly compared with those of control group. 4. The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with PR-HA decreased significantly compared with those of control group. 5. The number of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with that of control group. 6. The numbers of $CCR3^+\;cells,\;CD4^+\;cells\;and\;CD8^+\;cells$ in the lungs, and $CD3e^+/CD69^+$ in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. 7. The mRNA expression of ${\beta}-actin,\;TNF-{\alpha}$, IL-4, IL-5,IL-13 in the mice group treated with PR-HA with RT-PCR decreased significantly compared with those of control group. Conclusion : The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with PR-HA decreased significantly compared with those of control group. The number of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with that of control group. The numbers of $CCR3^+\;cells,\;CD4^+\;cells\;and\;CD8^+\;cells$ in the lungs, and $CD3e^+/CD69^+$ in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. The mRNA expression of ${\beta}-actin,\;TNF-{\alpha}$, IL-4, IL-5, IL-13 in the mice group treated with PR-HA with RT-PCR decreased significantly compared with those of control group. These result suggests that Platycodi Radix Herbal-acupuncture at Joksamni(St36) in C57BL/6mice may be an effictive part to OVA-induced asthma in C57BL/6 mice.

• The Plant Pathology Journal
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• v.21 no.3
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• pp.195-206
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• 2005

Spatial and temporal expression of pathogenesis-related (PR) gene and proteins has been recognized as inducible defense response in pepper plants. Gene expression and/or protein accumulation of PR-1, $\beta-1,3-glucanase$ and chitinase was predominantly found in pepper plants during the inoculations by Xanthomonas campestris pv. vesicatoria, Phytophthora capsici and Colletotrichum coccodes. PR-1 and chitinase genes were also induced in pepper plants in response to environmental stresses, such as high salinity and drought. PR-1 and chitinase gene expressions by biotic and abiotic stresses were regulated by their own promoter regions containing several stress-related cis-acting elements. Overexpression of pepper PR-1 or chitinase genes in heterogeneous transgenic plants showed enhanced disease resistance as well as environmental stress tolerances. In this review, we focused on the putative function of pepper PR-1, $\beta-1,3-glucanase$ and chitinase proteins and/or genes at the biochemical, molecular and cytological aspects.

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.90-96
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• 2004

The conformations of dicyclopropyl, isopropyl cyclopropyl, and diisopropylcarbenes were optimized using density functional theory (B3LYP/6-31G(d)). We showed that the optimized geometries of carbenes with cyclopropyl groups are fully in accord with those expected for bisected W-shaped conformations, in which the effective hyperconjugation of a cyclopropyl group with singlet carbene can occur. The stabilization energies were evaluated at the B3LYP/6-311+G(3df, 2p)//B3LYP/6-31G(d) + ZPE level using an isodesmic equation. The relative stability of carbenes is in the order $(c-Pr)_2$C: > (i-Pr)(c-Pr)C: > $(i-Pr)_2$C:, and a cyclopropyl group stabilizes carbene more than an isopropyl group by nearly 9 kcal/mol. Energies for the decomposition of diazo compounds to carbenes increase in the order $(c-Pr)_2$ < (i-Pr)(c-Pr) < $(i-Pr)_2$ by ~9 kcal/mol each. From a singlettriplet energy gap ($E_{ST}$) calculation, the singlet level is lower than the triplet level and the $E_{ST}$ shows a trend similar to the stabilization energy calculations. For comparison, the optimized geometries and stabilization energies for the corresponding carbocations were also studied at the same level of calculation. The greater changes in geometries and the higher stabilization energies for carbocations compared to carbenes can explain the greater hyperconjugation effect.