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Photocatalytic activity enhancement of TiO2 with adding Zn particles

  • Seo, Hyeon Jin;Boo, Jang Heon;Jang, Hyun Woo;Kim, Mi Jeong;Boo, Jin-Hyo
    • Applied Science and Convergence Technology
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    • v.25 no.6
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    • pp.162-165
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    • 2016
  • APhotocatalysis process uses ambient oxygen from air and irradiation, fundamentally UV light, to generate oxidation and reduction which can degrade almost all harmful organic and inorganic compounds to nontoxic substances. This study was focused on enhancement of photocatalytic activity which improves the photocatlytic efficiency with $TiO_2$ particle by mixing of certain amounts of Zn particles. We analyzed degradation of organic pollutant materials such as toluene and phenol with the mixed photocatalysis by using UV-visible spectrophotometer and obtained a result that photocatalytic activity is increased with increasing amount of Zn particle. Especially, in the case of $TiO_2$ (1 mmol) and Zn (0.1 mmol) mixture photocatalyst, we obtained at least 2 times higher photocatalytic activity compared with the commercially available $TiO_2$ photocatalyst (Degussa P-25), indicating that our mixed photocatalyts (Zn-doped $TiO_2$) is very effective of removing both organic dye and pollutants and the conversion rate of toluene is much faster than that of phenol.

Determination of Longitude and Latitude of Kongju National University Observatory (공주대학교 천문대의 경 ${\cdot}$ 위도 결정)

  • Kim, Hee-Soo
    • Journal of the Korean earth science society
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    • v.21 no.4
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    • pp.389-397
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    • 2000
  • The longitude and latitude of the Kongju National University Observatory was determined by using TM-1A theodolite and GPS(model: 4000SSI, GPS 45). In the observation using theodolite TM-1A observed the meridian transit time(KST) and meridian altitude of the 2 stars, ${\alpha}$ Aur and ${\alpha}$ Boo. In the observation using GPS measured the longitude and latitude by receiving data of 6 GPS satellites. The longitude and latitude of the Kongju National University Observatory was determined to 127$^{\circ}$8'33'.16 and 36$^{\circ}$28'14'.20, respectively.

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접촉쌍성 VW Bootis의 BVRI 측광과 분석

  • U, Su-Wan;Jeong, Min-Ji;Choe, Cheol-Hui;Kim, Dong-Bin;Song, Mi-Hwa;Kim, Cheon-Hwi
    • The Bulletin of The Korean Astronomical Society
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    • v.37 no.2
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    • pp.143.2-143.2
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    • 2012
  • 2012년 3월 7일부터 5월 9일까지, 총 8일간 소백산 천문대의 61cm 반사망원경에 부착된 PIXIS 2K CCD와 Johnson-Cousins의 표준필터 BVRI 4색 필터를 이용하여 접촉쌍성 VW Boo의 전 위상에 걸친 광도곡선을 획득하였다. 이 관측으로부터 7개의 극심시각(주식: 4개, 부식: 3개)을 결정하였다. 우리의 극심시각을 포함하여 여러 문헌에서 수집한 총 201개의 극심시각을 이용하여 주기분석을 수행하였다. VW Boo의 주기는 약 74년에 걸쳐 영년주기감소와 규칙적인 변화를 겪은 것으로 나타났다. 영년 주기감소율은 년간 $-1.595{\times}10^{-7}$일이며, 규칙적인 변화의 주기와 반진폭은 각각 약 29.8년과 0.00667일로 산출되었다. 영년주기감소를 질량이 큰 주성에서 반성으로의 질량이동에 의한 것으로 가정하였을 때, 그 질량이동율은 년간 $-1.26{\times}10^{-7}M_{\odot}/yr$이다. 규칙적인 변화를 제3천체에 의한 광시간 효과로 가정하여 구한 3천체의 최소 질량은 $0.19M_{\odot}$이다. Wilson-Devinney 쌍성 모형을 이용하여 우리의 BVRI 광도곡선을 분석하였다. 이 때, 광도곡선에 나타난 역 O'Connell 효과를 설명하기 위하여 흑점모형을 도입하였고, W형과 A형의 두 가지 경우를 상정하여 광도곡선 해를 산출하였다. 그 결과의 천체물리학적 의미를 논의한다.

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Genetic discontinuity of Digenea (Rhodomelaceae, Rhodophyta) from Mexico supports recognition of two new species, D. mexicana and D. rafaelii

  • Boo, Ga Hun;Robledo, Daniel;Andrade-Sorcia, Gabriella;Boo, Sung Min
    • ALGAE
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    • v.33 no.3
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    • pp.231-241
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    • 2018
  • Genetic continuity of Digenea simplex outside the Atlantic waters remains less studied, despite its long exposure to oriental folk medicine and wide distribution in tropical waters. Mitochondrial COI-5P and plastid rbcL sequences and morphology were investigated for plants from Mexico and additional specimens from Japan. Two new species, Digenea mexicana and Digenea rafaelii, are described for plants that would previously have been recognized as D. simplex in Mexico. D. mexicana grows to 10.5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, simple to branched determinate branchlets with eight pericentral cells, and tetrasporangia on inflated upper parts of determinate branchlets. It occurs intertidally in Quintana Roo, Yucatan Peninsula. D. rafaelii grows to 5 cm tall and has cylindrical axes, irregular or di-, trichotomous branches, and simple determinate branchlets with ten pericentral cells. It occurs intertidally in the Gulf of California. Both COI-5P and rbcL sequences revealed the genetic discontinuity between D. mexicana and D. rafaelii.

Shape Optimal Design of an Automotive Pedal Arm Using the Taguchi Method (다구찌 기법을 이용한 자동차 페달 암의 형상 최적설계)

  • Lee, Boo-Youn;Lee, Hyun-Woo
    • Journal of the Korean Society for Precision Engineering
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    • v.24 no.3 s.192
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    • pp.76-83
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    • 2007
  • The Taguchi method is applied to obtain the optimal design of an automotive pedal arm in consideration of the stiffness test specification. Design parameters are defined to describe shape of the pedal arm. Volume, maximum Von-Mises stress and maximum displacement of the pedal arm are established as the smaller-the-better characteristics. Optimal parameters are determined on the basis of the analyzed level averages of the characteristics.

Studies on the Hematology and Blood Chemistry of Swine (Piglets) from Birth to Weaning (돼지(자돈)의 성장에 따른 혈액학치 및 혈액화학치에 관한 연구)

  • Park Moo-Hyen;Kang Chung-Boo;Lee Ho-Jong
    • Journal of the korean veterinary medical association
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    • v.20 no.12
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    • pp.756-761
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    • 1984
  • This experiment was conducted to investigate the levels of hematological and blood chemical components in piglets from birth to weaning. Animals used were 8 newborne healthy piglets with about 1.3kg body weight. The number of RBC, Hb concentration, PCV(

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Studies on distribution of calcium and electromyogram in experimental hypocalcemia (재래산양의 Hypocalcemia에 있어서의 Ca의 동태 및 근전도학적인 연구)

  • Park Moo Hyen;Kang Chung Boo
    • Journal of the korean veterinary medical association
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    • v.17 no.2
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    • pp.63-71
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    • 1981
  • Experimental hypocalcemia was induced in normal goats by intravenous administration with various concentration of $Na_2-EDTA$ solution. Tile results are summarized as follows: 1. Progressive depression of reflexes and body temperature, paresis,

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