• Title/Summary/Keyword: Co/Pd

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Catalytic Oxidation of Toluene over Pd-Activated Alumina Catalysts at Low Temperature (활성알루미나에 담지한 팔라듐 촉매상에서 톨루엔의 저온 연소반응)

  • Lee, Ju-Yeol;Song, Hyung-Jin;Lee, Sang-Bong;Kim, Mi-Hyung;Jo, Young-Min
    • Journal of the Korean Applied Science and Technology
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    • v.29 no.2
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    • pp.339-347
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    • 2012
  • This study focuses on developing catalysts for the removal of toluene produced from paint booth. Toluene is one of the major VOC in painting, coating process. Pd catalysts have been used in hydrogenation oxidation and low temperature combustion reaction for toluene removal. Pd catalysts, even though it is very precious and expensive. Therefore, the prepared catalysts from minimizing the amount of Pd ratio (0.1~1.0wt%) were measured. As a result, 1.0wt% Pd(R) catalyst under all conditions showed the highest activity. These results may suggest that the catalytic activity is related to Pd dispersion according sintering atmosphere and Pd ratio in the manufacturing process through the analysis of SEM, XRD.

Magnetic Circular Dichroism Study of co Thin Films on Pd(111) Surface

  • Kim, Wookje;Kim, Wondong;Kim, Hyunjo;Kim, Jae-Young;Hoon Kho;Park, J.H.;Oh, S.J.
    • Proceedings of the Korean Vacuum Society Conference
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    • 1999.07a
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    • pp.169-169
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    • 1999
  • We studied magnetic properties of co thin films deposited on Pd (111) surface, which attracted much attention recently due to the perpendicular magnetic anisotropy, using magnetic circular dichroism(MCD). Special attention was paid on the effect of Pd capping and interface roughness on the direction of magnetic easy axis, and for that purpose MCD signals for all Co thicknesses were measured with two different ways : in-plane and out-of-plane geometry. In case of bare Co films deposited on smooth Pd(111) surface, no MCD signal was observed under 4$\AA$ co thickness. At 4$\AA$ Co thickness, MCD signal at the out-of-plane geometry was observed, and for thicker Co films, only in-plane MCD signal was measured. This type of magnetic easy axis transition has been reported for other cases like Co/Pt system. The effect of 5$\AA$ Pd capping on these bare Co films made an remarkable change on the transition of magnetic easy axis. Out-of-plane MCD signals exists up to 20$\AA$ Co thickness, and disappears at 24$\AA$ Co thickness. In-plane MCD signals first appears at 10$\AA$ Co thickness and gradually increases up to 24$\AA$ Co thickness. Between 10$\AA$ and 20$\AA$ Co thickness, in-plane and out-of-plane MCD signal coexist. The formation of multi-domain structure or the existence of tilted magnetic easy axis is an possible scenario for such an interesting coexistence. The effect of interface roughness was also tested by measuring MCD signal on Co films deposited on un-annealed Pd(111) surface. Out-of-plane MCD signal was observed up to 8$\AA$ Co thickness and the anisotropy of MCD signal at 4$\AA$ Co thickness was very large with respect to that of Co film deposited on the smooth substrate. Above 8$\AA$ thickness, there exists only in-plane MCD signal. From above results, it was concluded that both Pd capping and interface roughness induce and reenforce the perpendicular magnetic anisotropy. The large perpendicular magnetic anisotropy of Co/Pd multilayer system made by sputtering method can be well understood from our results.

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CO2 Reforming of Methane over Co-Pd/Al2O3 Catalysts

  • Itkulova, Sh. S.;Zhunusova, K.Z.;Zakumbaeva, G.D.
    • Bulletin of the Korean Chemical Society
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    • v.26 no.12
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    • pp.2017-2020
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    • 2005
  • The supported bimetallic Co-containing catalysts promoted by the different amount of noble metal (Pd) have been studied in the dry reforming of methane. The activity, selectivity, stability and resistance to the carbon deposition of Co-Pd/$Al_2O_3$ catalysts depend on both the catalyst composition and process conditions. It has been observed that the Co-Pd/$Al_2O_3$ catalysts produce the various oxygenates from $CO_2$ + $CH_4$ at moderate pressures.

PD-1 Expression in LPS-Induced Raw264.7 Cells Is Regulated via Co-activation of Transcription Factor NF-κB and IRF-1 (Lipopolysaccharide 유도된 Raw264.7 세포주에서 전사조절인자 NF-κB와 IRF-1의 공동작용에 의해 조절되는 PD-1 발현연구)

  • Choi, Eun-Kyoung;Lee, Soo-Woon;Lee, Soo-Woong
    • Korean Journal of Microbiology
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    • v.49 no.4
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    • pp.301-308
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    • 2013
  • Programmed Death-1 (PD-1) is one of the important immune-inhibitory molecules which was expressed in T cells, B cells, NKT cells, and macrophages activated by various immune activating factors. Lipopolysaccharide (LPS), the major component of the outer membrane of Gram-negative bacteria, is one of the crucial immunogens for PD-1 expression. However, there are only a few reports on the expression mechanisms of PD-1 in innate immune cells. In this study, we investigate the expression mechanisms of PD-1 in LPS-stimulated Raw264.7 cell lines by RT-PCR, Western Blot, flow cytometry as well as ChIP assay and co-immunoprecipitation. When Raw264.7 cells were stimulated with LPS, PD-1 expression was greatly up-regulated via PI3K and p38 signaling. Primary macrophages isolated from LPS-injected mice were also shown the increased expression of PD-1. In promoter assay, NF-${\kappa}B$ and IRF-1 binding regions in mouse PD-1 promoter are important for PD-1 expression. We also found that the co-activation of NF-${\kappa}B$ and IRF-1 is indispensable for the maximum PD-1 expression. These results indicate that the modulation of PD-1 expressed in innate immune cells could be a crucial for the disease therapy such as LPS-induced mouse sepsis model.

Magnetic Characteristics of CoNbZr amorphous Films with Pd addition

  • Song, J.S.;Wee, S.B.
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.05d
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    • pp.90-95
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    • 2003
  • The present paper is to investigate the phase stability and soft magnetic properties of amorphous CoNbZr films when Pd is added as a substitution for CoNbZr alloys. The films were prepared by a RF magnetron sputtering method. The CoNbZrPd films deposited on Si wafers exhibited amorphous structures being independent upon the amount of Pd added in the films. On the addition of 4.34% Pd, the excellent soft magnetic characteristics of the films were observed with a coercive force of 0.54 Oe and an anisotropy field of 11 Oe, whereas a coercive force of 1 Oe and an anisotropy field of 3.5 Oe were shown in the film without the addition of Pd. The increased anisotropy field and low coercive force of the films may be attributed to the occupancy of Pd in the preferred sites parallel to the external magnetic field applied on the deposition process. A permeability of about 1100 was kept constant in the operation frequency ranging up to 100 MHz, which can be explained by the Landau-Lifshitz formula.

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Soft Magnetic Properties of CoNbZr amorphous Films with Pd addition

  • Song, J.S,;Wee, S.B,
    • Proceedings of the Korean Society Of Semiconductor Equipment Technology
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    • 2002.11a
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    • pp.54-58
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    • 2002
  • The present paper is to investigate the phase stability and soft magnetic properties of amorphous CoNbZr films when Pd is added as a substitution for CoNbZr alloys. The films were prepared by a RF magnetron sputtering method. The CoNbZrPd films deposited on Si wafers exhibited amorphous structures being independent upon the amount of Pd added in the films. On the addition of 4.34% Pd, the excellent soft magnetic characteristics of the films were observed with a coercive force of 0.54 Oe and an anisotropy field of 11 Oe, whereas a coercive force of 1 Oe and an anisotropy field of 3.5 Oe were shown in the film without the addition of Pd. The increased anisotropy field and low coercive force of the films may be attributed to the occupancy of Pd in the preferred sites parallel to the external magnetic field applied on the deposition process. A permeability of about 1100 was kept constant in the operation frequency ranging up to 100 MHz, which can be explained by the Landau-Lifshitz formula.

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Development of External UHF PD Sensor for the Detection of Partial Discharge in $SF_6$ Gas-insulated Switchgear (가스절연 개폐장치의 PD검출용 UHF 대역 외장형 센서 제작 및 감도 특성)

  • Lee, Chang-R.;Hong, C.Y.;Choi, B.H.;Yoon, J.H.;Nam, G.C.;Jung, J.G.
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1799-1801
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    • 2004
  • We have developed the external-type PD sensors for detecting of the electromagnetic waves up to ultra high frequency (UHF) bands, propagating in various type of GIS. Sufficiently high sensitivity and accuracy for practical use were achieved for the external PD sensor. The experience at the fields and the criteria for the judgment are also discussed in detail.

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Study on Exchange Coupling in Bilayer Systems using Co-Based Multilayer Thin Films (Co계 다층박막을 이용한 이중막에서 Direct Overwriting을 위한 교환결합 연구)

  • 문기석;최석봉;신성철
    • Journal of the Korean Magnetics Society
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    • v.6 no.1
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    • pp.15-20
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    • 1996
  • Co/Pd와 Co/Pd 다층박막으로 구성된 이중막 시스템에서 direct overwriting을 구현하는데 필수적인 교환결합 (exchange coupling)에 대하여 연구하였다. Co/Pd 및 Co/Pd 다층박막을 수직자성을 가지도록 하기 위하여 Co층의 두께를 4- .angs. 이하로 하여 전자빔 증착법으로 제작한 후 x-ray 회절 실험으로 구조 분석을 하였고, Kerr spectrometer, VSM을 사용하여 자기 및 자기광학적 성질을 조사하였다. 기억막과 기준막으로 구성된 이중막에서는 exchange coupling이 커서 자화반전이 두 박막에서 동시에 일어나며, 두 박막사이에 적당한 두께의 비자성 사이막(non-magnetic spacer)이 존재하는 경우에는 두 박막사이의 교환결합의 크기가 줄어들어서 두 박막의 자화반전이 분리되어 계단식 자화곡선이 생겼다. 또 비자성 사이막이 두꺼우면 두 박막사이의 교환결합이 사라짐이 관찰 되었다. 두 박막사이의 교환결합은 자구 기록 실험을 통해서도 그 존재를 확인할 수 있었다.

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Detection of Partial Discharge in $SF_6$ Gas-insulated Switchgear Using External UHF PD sensors (가스절연기기에서 외장형 PD 센서를 이용한 부분방전 검출)

  • Lee, Chang-R.;Hong, C.Y.;Choi, B.H.;Yoon, J.H.;Nam, G.C.;Jung, J.G.
    • Proceedings of the KIEE Conference
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    • 2004.05b
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    • pp.125-127
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    • 2004
  • We have developed the external-type PD sensors for detecting of the ultra high frequency (UHF) signals in various type of GIS. Sufficiently high sensitivity and accuracy for practical use were achieved for the PD sensor. The experience at the fields and the criteria for the judgment are also discussed in detail.

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Development and application of the semi-internal type UHF PD sensor for Gas Insulated Switchgear (초고압 GIS의 CT 단자부를 이용한 Semi-내장형 UHF PD 센서 개발 및 적용)

  • Kang, W.J.;Lee, D.H.;Lee, Y.H.;Shin, Y.S.;Kim, Y.G.;Oh, I.S.
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.2038-2039
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    • 2007
  • In this work, a novel semi-internal type UHF PD sensor has been proposed and related investigations has been performed in order to detect the partial discharges that could be possibly produced at the insulation system of the gas insulated switchgear(GIS). This sensor was designed to mount on the CT terminal hole of GIS using the spiral antenna theory. Therefore this type sensor can be install on GIS during the power apparatus has been operation and better sensitivity compare to the commercial external type UHF PD sensor.

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