• 제목/요약/키워드: O-jang

검색결과 3,474건 처리시간 0.039초

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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    • 제25권6호
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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.

$O_2$ 플라즈마 처리에 따른 ITO 투명전도막의 특성변화

  • 유재혁;공수철;신상배;신익섭;양신혁;장지근;장호정
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2006년도 춘계학술대회
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    • pp.259-264
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    • 2006
  • ITO 투명전도막은 현재 FPD(flat panel display)소자의 전극으로 사용되고 있다. 특히 근래에 많은 연구가 진행되고 있는 유기발광다이오드(organic light emitting diode: OLED) 소자의 제작에 투명전도막으로 많은 응용이 되고 있다. ITO 를 이용한 디스플레이 소자는 ITO 의 계면 상태와 전기적 특성에 따라 그 특성이 크게 변한다. 본 연구에서는 $O_2$ 플라즈마 처리를 통하여 ITO 투명전도막의 전기적 특성 및 표면상태의 변화에 대하여 조사하고, 이러한 특성 변화에 따라 현재 많은 연구가 진행되고 있는 OLED 소자의 제작에 응용하기 위하여 유기용액을 이용한 접촉각 측정을 통하여 $O_2$ 플라즈마 처리에 따른 ITO 투명전도막과 유기용액의 접착력에 대하여 고찰하였다.

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$TiO_2$의 첨가가 ZnO계 세라믹 바리스타에 미치는 전기적인 영향 (Influence of the Conduction Properties on ZnO-Based Ceramic Varistor with $TiO_2$ Additives)

  • 이상석;장경욱;이준웅
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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    • pp.234-238
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    • 1987
  • In this paper, the used specimen composition was added basic additives ($Bi_2O_3\;lmol%$, $Sb_2O_3\;lmol%$, CoO 0.5 mol%, MnO 0.5mol%) to ZnO powder, and $TiO_2$ (1,2,3,4 mol%) to the above basic composition. It appears that there are four regions of conduction current depended upon the strength of the applied electric field ; Ohimic region, Poole-Frenkel region, Schottky region and Tunneling region. Increasing of $TiO_2mol%$, the breakdown voltages of ZnO ceramic varistors are decreased. The decrease of breakdown voltages was explained with the decrease of potential barrier height. Moreover, V-I characteristics with temperature dependence are decreased with increasing of $TiO_2mol%$.

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The Effect of Digital Transformation on SMEs Using O2O Platforms: Focusing on Customer Engagement

  • 신가영;장문경;정재연
    • 한국벤처창업학회:학술대회논문집
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    • 한국벤처창업학회 2022년도 춘계학술대회
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    • pp.129-134
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    • 2022
  • This research investigates the effect of SMEs' digital transformation (DX) efforts in O2O platforms on customer engagement. Among the three DX stages (i.e., digitization, digitalization, and DX), this study focuses on digitalization, a practically viable DX phase for SMEs using O2O platforms. This study categorizes the DX efforts of SMEs into three: information diversity, responsiveness to customers, and the degree of functional use. To analyze the impact of these efforts on customer engagement, we conduct the zero-inflated negative binomial regression using the dataset of Naver Smartplace, one of the representative O2O platforms in South Korea. The analysis result confirms that all three factors have positive impacts on customer engagement. Therefore, this study demonstrates that employing O2O platforms can be an effective strategy for SMEs lacking resources to achieve successful DX.

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The Effect of Digital Transformation on SMEs using O2O Platforms: Focusing on Customer Engagement

  • Kayoung Shin;Jaeyeon Jeong;Moonkyoung Jang
    • Asia pacific journal of information systems
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    • 제32권3호
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    • pp.580-600
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    • 2022
  • The purpose of this study is to investigates the effect of SMEs' digital transformation efforts in O2O platforms on customer engagement. This study focuses on digitalization, which is a practically viable phase for SMEs using O2O platforms among the three digital transformation stages (digitization, digitalization, and digital transformation). This study specifically categorizes digital transformation efforts into three categories: information diversity, responsiveness to customers, and the degree of functional use. To analyze the impact of these efforts on customer engagement, we conducted a zero-inflated negative binomial regression using the dataset provided by Naver SmartPlace, a representative O2O platform in South Korea. The results present that the positive relationship between these aforementioned factors and customer engagement. Thus, this study demonstrates that utilizing O2O platforms can be an effective strategy for SMEs that lack the resources to achieve a successful digital transformation.

The Health Effects of Asian Dust in Korea

  • Kwon Ho-Jang
    • 대한예방의학회:학술대회논문집
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    • 대한예방의학회 2004년도 동계 국제 심포지움
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    • pp.49-64
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    • 2004
  • o The risk of being admitted with respiratory disease is increased by 9% on the Asian dust day o The risk of cardiovascular admission is increased by 5% o During the great dust event in 2002, the counts of respiratory admission seems to be increased, but we couldn't observed the epidemic of respiratory disease o The Asian dust events are weakly associated with daily mortality

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Preparation of Fe3O4/SiO2 Core/Shell Nanoparticles with Ultrathin Silica Layer

  • Jang, Eue-Soon
    • 대한화학회지
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    • 제56권4호
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    • pp.478-483
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    • 2012
  • We successfully synthesized $Fe_3O_4/SiO_2$ nanoparticles with ultrathin silica layer of $1.0{\pm}0.5$ nm that was fine controlled by changing concentration of $Fe_3O_4$. Among various reaction conditions for silica coating, increasing concentration of $Fe_3O_4$ was more effective approach to decrease silica thickness compared to water-to-surfactant ratio control. Moreover, we found that concentration of the 1-octanol is also important factor to produce the homogeneous $Fe_3O_4/SiO_2$ nanoparticles. The present approach could be available to apply on preparation of other core/shell nanoparticles with ultrathin silica layer.