• Title/Summary/Keyword: $InBO_3$

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Effect of La3+ and Ce3+ Ions on Photoluminescence Behavior of YBO3: Tb Phosphors (YBO3: Tb 형광체의 광특성에 대한 La3+ 및 Ce3+ 이온의 영향)

  • On, Ji-Won;Lee, Jeong-Baek;Kim, You-hyuk
    • Korean Journal of Materials Research
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    • v.13 no.8
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    • pp.509-513
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    • 2003
  • In the present investigation, $La^{3+}$ and $Ce^{V}$ ions were substituted for $Y^{3+}$ in the $YBO_3$: Tb in various concentrations. It has been found that these phosphors form solid solutions within limited concentration ranges Excitation and emission spectra under 254 nm and 147 nm were investigated for these phosphors to evaluate influences of $La^{3+}$ and $Ce^{3+}$ ions on brightness and CIE color coordinates. It has been observed that brightness of $(Y, La)BO_3$: Tb under 254 nm and 147 nm when $La^{3+}$ ions are added show an increase of 2.7 times and 1.25 times, respectively. On the other hand, emission intensities of peaks in $Y_{0.8-x}$ $BO_3$: $Tb_{0.2}$ , $Ce_{x}$ show continuos decrease as $Ce^{3+}$ / content is increased from 0 to 0.4. CIE color coordinates of prepared phosphors show yellowish green which is needed to be improved to be used for display applications.

Effect of Sucrose, Calcium and Boron Added in the Medium on Pollen Germination of Peach(Prunus persica SIEB) (Sucrose, 칼슘, 붕소 첨가가 복숭아 화분 발아에 미치는 영향)

  • Cheon, Beong-Duck;Choi, In-Soo;Kang, Jum-Soon
    • Journal of Life Science
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    • v.16 no.4
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    • pp.561-565
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    • 2006
  • This study was carried out to identify the effect of sucrose, calcium, and boron on the increase of pollen germination frequency in peach $(Prunus\;persica\;_{SIEB})$ under various temperature levels. The highest pollen germination was obtained at $20^{\circ}C$. Pollen germination was completed in 3.5 hrs. after planting of pollen on the basal medium which was composed of 1% agar and 10% sucrose, and conditioned pH 5.5. The optimum concentrations of sucrose and $H_3BO_3$ at $25^{\circ}C$ were 10% and $100\;mg\;{\cdot}\;L^{-1}$, respectively. However, $CaCl_2$ inhibited pollen germination in peach. Eight peach cultivars showed significantly different germinabilities at $10^{\circ}C$ on the basal medium. 'Nagasawa-Hakuho' showed the highest germinability of 26.1%, and 'Baekmijosaeng' showed the lowest germinability of 0.1%. $H_3BO_3$ strongly promoted pollen germination frequency when added to the germination medium at $10^{\circ}C$. Optimum concentration was $100\;mg\;{\cdot}\;L^{-1}$.

Surface Characteristics and Photocatalytic Propertiy of B Doped TiO2 Layer Synthesized by Plasma Electrolytic Oxidation Process (Plasma Electrolytic Oxidation 방식으로 제조된 B Doped TiO2의 표면특성과 광촉매 특성)

  • Lee, Jong-Ho;Lee, Young-Ki;Kim, Young-Jig;Oh, Han-Jun
    • Korean Journal of Materials Research
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    • v.31 no.10
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    • pp.552-561
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    • 2021
  • For the purpose of manufacturing a high efficiency TiO2 photocatalyst, B-doped TiO2 photocatalysts are synthesized using a plasma electrolytic oxidation method in 0.5 M H2SO4 electrolyte with different concentrations of H3BO3 as additive. For the B doped TiO2 layer fabricated from sulfuric electrolyte having a higher concentration of H3BO3 additive, the main XRD peaks of (101) and (200) anatase phase shift gradually toward the lower angle direction, indicating volume expansion of the TiO2 anatase lattice by incorporation of boron, when compared with TiO2 layers formed in sulfuric acid with lower concentration of additive. Moreover, XPS results indicate that the center of the binding energy peak of B1s increases from 191.45 eV to 191.98 eV, which suggests that most of boron atoms are doped interstitially in the TiO2 layer rather than substitutionally. The B doped TiO2 catalyst fabricated in sulfuric electrolyte with 1.0 M H3BO3 exhibits enhanced photocurrent response, and high efficiency and rate constant for dye degradation, which is ascribed to the synergistic effect of the new impurity energy band induced by introducing boron to the interstitial site and the improvement of charge transfer reaction.

The Introduction of the Toi-Maru of 3-Dori type House in the Joseon Dynasty and the Change of the Sang-chun-heon Historic House - Focused on the Comparative Study of the Yang-dong village's Du-gok Historic House (조선시대 3량가 주택의 툇마루 도입과 상춘헌고택의 변화 - 양동마을 두곡고택과의 비교연구를 중심으로 -)

  • Bae, Chang-Hyun
    • Journal of architectural history
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    • v.32 no.3
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    • pp.31-38
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    • 2023
  • Most of the changes found on the toi-maru of the Sang-chun-heon Historic House indicate that the upper structure of the toi-maru of the late Joseon Dynasty houses where toi-bo was installed was not completed in an instant. Toi-maru with stud is especially typical in 3-Dori type Structure, and can be found in many historic houses in Yang-dong Village, where the many 3-Dori type Structure is located. This type can be interpreted as the intermediate type that began at the eaves was settled as a toi-maru with a separate toi-bo. It seems that the toi-maru in front of the on-dol room at the time of the construction of the Sang-chun-heon historic house would not have been the same as it is now. The members dividing the on-dol room, the walls, and the various incomplete appearances seen in the window composition can be construed as traces of the change. The fact that all three types of houses that occurred during the spread of toi-maru after the mid-Joseon Dynasty can be examined can be added to the existing evaluation of cultural property houses in Yang-dong Village.