• 제목/요약/키워드: WoS

검색결과 263건 처리시간 0.034초

커뮤니케이션 관점에서 살펴본 '데이터 건축'의 특성 연구 - MVRDV WoZoCo를 중심으로 - (A study on the Characteristics of 'Data Architecture' from the communicational point of view - Focused on WoZoCo by MVRDV -)

  • 김은용;임경란
    • 한국실내디자인학회:학술대회논문집
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    • 한국실내디자인학회 2005년도 춘계학술발표대회 논문집
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    • pp.60-63
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    • 2005
  • After 20th century, Data tend to important in a sphere of architecture. In this study such tendency was christened a Data architecture. And The purpose of the study is to define data architecture and to find out of data architecture's merits from a communicational point of view. Above-mentioned Communication means that exchange all kinds of something between each other.

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50%TiO2/6%WO3 졸 용액에서의 톨루엔 처리에 대한 아세톤의 광활성 증가효과 (Photolysis Improvement of Toluene in 50%TiO2/6%WO3 Sol Solutions Sensitized by Acetone)

  • 신혜승;김재현
    • 한국환경보건학회지
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    • 제38권3호
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    • pp.261-268
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    • 2012
  • Objectives: The photocatalytic degradation of toluene in a batch mode photoreactor for the purpose of the hazardous waste treatment was investigated. Methods: Kinetic experiments using a low pressure mercury lamp (Lambda Scientific Pty Ltd, 50 Watt) emitting both UV and visible light were performed at $31^{\circ}C$ over toluene concentrations ranging from 10 to 50 mg/l in water with $50%TiO_2/6%WO_3$ (TW) concentration of 1 g/l at a pH of 6. Results: Kinetic studies showed that $50%TiO_2/6%WO_3$ (TW) photocatalyst was highly active in toluene degradation; we observed that 99% of the pollutant was degraded after six hours under visible irradiation; furthermore, we observed that adsorption onto TW catalyst was responsible for the decrease of toluene with pseudo-first order kinetics. It was also found that oxygen as a radical source in the sol medium played a significant role in affecting the photodegradation of toluene, especially with a two-fold elevation. This increase was achieved by a more than four-fold elevation of the photodegradation of toluene in the presence of acetone than without, presumably via an energy transfer mechanism. Conclusions: We concluded that photodegradation in acetone and oxygen molecules along with TW was an effective method for the removal of toluene from wastewater.

STM Tip Catalyzed Adsorption of Thiol Molecules and Functional Group-Selective Adsorption of a Bi-Functional Molecule Using This Catalysis

  • 민영환;정순정;윤영상;박은희;김도환;김세훈
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
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    • pp.197-197
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    • 2011
  • In this study, in contrast with cases in which Scanning Tunneling Microscopy (STM) tip-induced reactions were instigated by the tunneling electrons, the local electric field, or the mechanical force between a tip and a surface, we found that the tungsten oxide (WO3) covered tungsten (W) tip of a STM acted as a chemical catalyst for the S-H dissociative adsorption of phenylthiol and 1-octanethiol onto a Ge(100) surface. By varying the distance between the tip and the surface, the degree of the tip-catalyzed adsorption could be controlled. We have found that the thiol head-group is the critical functional group for this catalysis and the catalytic material is the WO3 layer of the tip. After removing the WO3 layer by field emission treatment, the catalytic activity of the tip has been lost. 3-mercapto isobutyric acid is a chiral bi-functional molecule which has two functional groups, carboxylic acid group and thiol group, at each end. 3-Mercapto Isobutyric Acid adsorbs at Ge(100) surface only through carboxylic acid group at room temperature and this adsorption was enhanced by the tunneling electrons between a STM tip and the surface. Using this enhancement, it is possible to make thiol group-terminated surface where we desire. On the other hand, surprisingly, the WO3 covered W tip of STM was found to act as a chemical catalyst to catalyze the adsorption of 3-mercapto isobutyric acid through thiol group at Ge(100) surface. Using this catalysis, it is possible to make carboxylic acid group-terminated surface where we want. This functional group-selective adsorption of bi-functional molecule using the catalysis may be used in positive lithographic methods to produce semiconductor substrate which is terminated by desired functional groups.

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좋은 죽음에 대한 인식, 연명치료 중단 및 안락사에 대한 종합병원 간호사의 태도 (Recognition of Good Death, Attitude towards the Withdrawal of Life-Sustaining Treatment, and Attitude towards Euthanasia in Nurses)

  • 김숙남;김현주
    • Journal of Hospice and Palliative Care
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    • 제19권2호
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    • pp.136-144
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    • 2016
  • 목적: 본 연구는 간호사들을 대상으로 좋은 죽음에 대한 인식, 연명치료 중단과 안락사에 대한 태도수준과 변인 간의 관련성을 확인하여 생명윤리교육의 근거를 마련하는데 실제적인 자료로 활용하고자 이루어졌다. 방법: 연구 대상은 서울, 부산경남, 및 경북지역에 소재한 500병상 이상의 6개 종합병원에서 6개월 이상 근무한 간호사 중 본 연구의 목적을 이해하고 연구 참여를 허락한 자 218명을 대상으로 편의표집 하였다. 연구도구는 좋은 죽음 인식 측정도구(The Concept of Good Death Measure), 연명치료 중단 측정도구와 안락사 측정도구(Attitudes toward Euthanasia)를 사용하였다. 수집된 자료는 SPSS 21 WIN 프로그램을 이용 서술통계, Independent t-test와 one-way ANOVA 및 Pearson's correlation coefficient로 분석하였다. 결과: 간호사의 좋은 죽음에 대한 인식, 연명치료 중단과 안락사에 대한 태도는 보통 수준이었다. 간호사의 일반적 특성에 따른 좋은 죽음에 대한 인식, 연명치료 중단과 안락사에 대한 태도차이는 교육수준, 근무경력 및 신앙의 중요성에서 유의하게 나타났다. 좋은 죽음과 연명치료 중단에 대한 태도는 역 상관관계가 있었고, 연명치료 중단과 안락사에 대한 태도는 순 상관관계가 있었다. 결론: 말기환자를 돌보는 과정에서 발생하는 윤리적 문제를 다루는데 간호사들은 숙련되어야 한다. 좋은 죽음에 대한 간호사의 인식확립과 연명치료 중단과 안락사와 같은 존엄사와 관련된 개념에 대한 이해와 윤리적 갈등 상황에서의 판단과 해결능력에 관한 생명윤리교육의 활성화가 필요하다고 본다.

질소산화물 제거용 상용 $V_2O_5-WO_3/TiO_2$ SCR 폐 촉매의 재생 효과 고찰 (A Study on the Regeneration Effects of Commercial $V_2O_5-WO_3/TiO_2$ SCR Catalyst for the Reduction of NOx)

  • 박해경
    • 대한환경공학회지
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    • 제27권8호
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    • pp.859-869
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    • 2005
  • 소각장 off gas에 장기간 노출이 되어 활성이 저하된 상용 $V_2O_5-WO_3/TiO_2$ aged 촉매를 물리화학적 방법으로 재생 처리를 수행한 후, 재생 처리에 따른 촉매의 물성 변화를 확인하고 이에 따른 촉매 활성변화를 고찰하였다. 촉매의 특성분석은 XRD(x-ray diffractometer), BET, POROSIMETER, EDX(energy dispersive x-ray spectrometer), ICP(inductively coupled plasma), TGA(thermogravimetric Analyze,), SEM(scanning electron microscopy)등을 이용하여 수행하였고 NOx 전환반응실험은 소각장 off gas를 모사하여 $NH_3$에 의한 SCR 반응을 통해 수행하였다. 본 연구에서 수행된 재생처리 방법 중, 열처리 방법으로 재생처리를 수행 할 경우 fresh 촉매환성의 95% 이상을 회복하였으며, 화학적 재생 처리 방법으로는 산성용액의 경우는 pH가 5인 용액으로 재생 처리된 촉매가, 염기성 용액의 경우는 pH가 12인 용액으로 재생 처리된 촉매가 fresh 촉매활성의 90% 이상의 촉매 활성을 회복 하였다. 촉매 특성 분석 결과, 상기와 같은 방법으로 재생 처리된 촉매의 경우 비표면적은 fresh 촉매의 $85{\sim}95%$ 수준으로 회복 되었으며, aged 촉매 표면에 축적되어 있던 촉매 비활성 물질로 잘 알려진 황(S)이나 칼슘(Ca)등은 최대 99%이상 제거 되었다. Aged 촉매 표면상의 인(P), 크롬(Cr), 아연(Zn) 등과 같은 중금속의 경우는 최대 95% 이상 제거 되었으나 납(Pb)의 경우는 제거율이 $10{\sim}30%$ 수준으로 매우 미흡한 것으로 나타났다.

비-휘발성 저항 변화 메모리 응용을 위한 WOx 물질의 전기적 특성 연구 (A Study of the Electrical Characteristics of WOx Material for Non-Volatile Resistive Random Access Memory)

  • 정균호;김경민;송승곤;박윤선;박경완;석중현
    • 한국전기전자재료학회논문지
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    • 제29권5호
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    • pp.268-273
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    • 2016
  • In this study, we observed current-voltage characteristics of the MIM (metal-insulator-metal) structure. The $WO_x$ material was used between metal electrodes as the oxide insulator. The structure of the $Al/WO_x/TiN$ shows bipolar resistive switching and the operating direction of the resistive switching is clockwise, which means set at negative voltage and reset at positive voltage. The set process from HRS (high resistance state) to LRS (low resistance state) occurred at -2.6V. The reset process from LRS to HRS occurred at 2.78V. The on/off current ratio was about 10 and resistive switching was performed for 5 cycles in the endurance characteristics. With consecutive switching cycles, the stable $V_{set}$ and $V_{reset}$ were observed. The electrical transport mechanism of the device was based on the migration of oxygen ions and the current-voltage curve is following (Ohm's Law ${\rightarrow}$ Trap-Controlled Space Charge Limited Current ${\rightarrow}$ Ohm's Law) process in the positive voltage region.

Y2O3-AlN 세라믹스의 생성상 및 물성에 미치는 WO3 및 Ga2O3의 첨가효과 (Effect of WO3 or Ga2O3 Addition on the Phase Evolution and Properties of Y2O3-Doped AlN Ceramics)

  • 신현호;윤상옥;김신;황인준
    • 한국세라믹학회지
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    • 제50권3호
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    • pp.206-211
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    • 2013
  • The effect of a $WO_3$ or $Ga_2O_3$ addition on the densification, phase evolution, optical reflectance, and elastic and dielectric properties of $Y_2O_3$-doped AlN ceramics sintered at $1800^{\circ}C$ for 3 h is investigated. The investigated compositions of the additives are 4.5 wt% $Y_2O_3$ (YA), 3.5 wt% $Y_2O_3$-1.0 wt% $Ga_2O_3$ (YGA), and 3.5 wt% $Y_2O_3$-1.0 wt% $WO_3$ (YWA). $YAlO_3$ and $Y_4Al_2O_9$ form as the secondary phases in all of the investigated compositions, whereas $W_2B$ appears additionally in the YWA. In the YGA, Ga is detected in the AlN grains, indicating that the dissolution of $Ga_2O_3$ into the AlN lattice occurs. The addition of $WO_3$ blackens the specimen more significantly than that of $Ga_2O_3$ does. In all of the investigated specimens, the linear shrinkage and the apparent density are above 20 percent and in the range of 3.34-3.37 $g/cm^3$, respectively. The elastic modulus, Poisson's ratio, the dielectric constant, and the dielectric loss are in the ranges of 335-368 GPa, 0.146-0.237, 8.60-8.63, $2.65-3.95{\times}10^{-3}$, respectively. The sinterability and the properties of $Y_2O_3$-doped AlN ceramics are not much altered by the addition of $WO_3$ or $Ga_2O_3$.

Fabrication of Microcrystalline NaPbLa(WO4)3:Yb3+/Ho3+ Phosphors and Their Upconversion Photoluminescent Characteristics

  • Lim, Chang Sung;Atuchin, Victor V.;Aleksandrovsky, Aleksandr S.;Denisenko, Yuriy G.;Molokeev, Maxim S.;Oreshonkov, Aleksandr S.
    • 한국재료학회지
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    • 제29권12호
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    • pp.741-746
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    • 2019
  • New triple tungstate phosphors NaPbLa(WO4)3:Yb3+/Ho3+ (x = Yb3+/Ho3+ = 7, 8, 9, 10) are successfully fabricated by microwave assisted sol-gel synthesis and their structural and frequency upconversion (UC) characteristics are investigated. The compounds crystallized in the tetragonal space group I41/a and the NaPbLa(WO4)3 host have unit cell parameters a = 5.3927(1) and c = 11.7961(3) Å, V = 343.05(2) Å3, Z = 4. Under excitation at 980 nm, the phosphors have yellowish green emissions, which are derived from the intense 5S2/5F45I8 transitions of Ho3+ ions in the green spectral range and strong 5F55I8 transitions in the red spectral range. The optimal Yb3+:Ho3+ ratio is revealed to be x = 9, which is attributed to the quenching effect of Ho3+ ions, as indicated by the composition dependence. The UC characteristics are evaluated in detail under consideration of the pump power dependence and Commission Internationale de L'Eclairage chromaticity. The spectroscopic features of Raman spectra are discussed in terms of the superposition of Ho3+ luminescence and vibrational lines. The possibility of controlling the spectral distribution of UC luminescence by the chemical content of tungstate hosts is demonstrated.

Electron Reflecting Layer with the WO3-ZnS:Cu.Al-PbO-SiO2 System Concerned in Doming Property of Shadow Mask in CRT

  • 김상문;조윤래
    • 한국세라믹학회지
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    • 제39권12호
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    • pp.1124-1127
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    • 2002
  • In this paper, we studied the effects of the electron reflection on shadow mask on which the electron reflecting materials with $WO_3-ZnS:Cu.Al-PbO-SiO_2$ system were screen-printed and we evaluated the variation of the electron beam mislanding in CRT. As a result, the green emitted spectra on the electron reflecting layer are observed due to the transformation of the electron energy, when the electron impacted on shadow mask. The beam mislanding is reduced about 40% in comperision with that of CRT made by the conventional method.