Zn ion의 영향에 따른 $(Y,\;Zn)_2O_3$:$Eu^{3+}$ 적색 형광체의 발광특성

송영현,문지욱,박우정,윤대호,Song, Y.H.,Moon, J.W.,Park, W.J.,Yoon, D.H. 한국결정성장학회 2008 한국결정성장학회지 Vol.18 No.6

본 연구에서는 자외선 영역에서 발광하는 우수한 특성의 적색 형광체를 얻기 위하여 고상 반응법으로 air 분위기에서 $1200^{\circ}C$에서 6시간 동안 열처리하여 $(Y,\;Zn)_2O_3$:$Eu^{3+}$를 Zn 이온의 농도 변화에 따라 실험하였다. $(Y,\;Zn)_2O_3$:$Eu^{3+}$를 XRD에 의해 비교 분석한 결과 주요 peak들이 JCPDS card(No. 41-1105)와 거의 일치하는 것을 확인하였다. 그러나 Zn 이온치 농도가 5 mol% 이상일 때 XRD에서 ZnO의 peak이 관찰되는 것을 확인 하였다. 이로 인하여 Zn 이온의 농도가 5 mol% 이하일 때 불순물 상 없이 $Y_2O_3$ 구조에 잘 고용되는 것을 확인하였다. $(Y,\;Zn)_2O_3$:$Eu^{3+}$의 발광 peak은 여기 흡수 영역인 ${\lambda}ex=254\;nm$를 기준으로 612 nm 영역에서 $Eu^{3+}$ 이온의 $^5D_0{\rightarrow}^7F_2$에 전형적인 에너지 천이에 의해 가장 강한 발광 peak을 나타내는 것을 확인하였으나 Zn 이온의 농도가 10 mo1% 이상일 때 갑자기 발광 peak이 현저히 감소하는 것을 확인하였고 최대의 발광 peak을 가질 때 형광체의 조성은 $(Y_{0.95},\;Zn_{0.05})_2O_3$:$Eu^{3+}_{0.075}$이였고 입자 size는 $0.4{\sim}3{\mu}m$로 확인되었다. To enhance the luminescence properties, the red phosphor composed of $(Y,\;Zn)_2O_3$:$Eu^{3+}$ as doping concentration of Zn ion is synthesized at $1200^{\circ}C$ for 6 hrs in air atmosphere by conventional solid reaction method. As a result of the red phosphor $(Y,\;Zn)_2O_3$:$Eu^{3+}$ is measured X-ray diffraction (XRD), The main peak is nearly corresponded to the same as JCPDS card (No. 41-1105). When the doping concentration of Zn ion is more than 5 mol%, However, the ZnO peak is showed by XRD analysis. Therefore, when the doping concentration of Zn ion is less than 5 mol%, the Zn ion is well mixed in $Y_2O_3$ structure without the impurity phases. The photoluminescence (PL) properties is shown as this phosphor is excited in 254 nm region and the highest emission spectra of $(Y,\;Zn)_2O_3$:$Eu^{3+}$ has shown in 612 nm region because of a typical energy transition ($^5D_0{\rightarrow}^7F_2$) of $Eu^{3+}$ ion. As the doping concentration of Zn ion is more than 10 mol%, the emission peak is suddenly decreased. when the highest emission peak as doping concentration of Zn ion is shown, the composition of this phosphor is $(Y_{0.95},\;Zn_{0.05})_2O_3$:$Eu^{3+}_{0.075}$ and the particle size analyzed by FE-SEM is confirmed from 0.4 to $3{\mu}m$.

Separation dynamics of hydrogen isotope gas in mesoporous and microporous adsorbent beds at 77 K: SBA-15 and zeolites 5A, Y, 10X

Chu, X.Z.,Cheng, Z.P.,Xiang, X.X.,Xu, J.M.,Zhao, Y.J.,Zhang, W.G.,Lv, J.S.,Zhou, Y.P.,Zhou, L.,Moon, D.K.,Lee, C.H. Pergamon Press ; Elsevier Science Ltd 2014 International journal of hydrogen energy Vol.39 No.9

The separation of a hydrogen isotope mixture on porous materials was studied using equilibrium and breakthrough experiments. The adsorption equilibria of H<SUB>2</SUB> and D<SUB>2</SUB> on SBA-15 with mesopores and molecular sieves 5A, Y, and 10X with micropores were measured at 77 K using the volumetric method. The breakthrough experiments of a H<SUB>2</SUB> and D<SUB>2</SUB> mixture in each adsorbent bed were carried out at various conditions of flow rate and pressure. The equilibrium ratio of D<SUB>2</SUB> to H<SUB>2</SUB> on mesoporous molecular sieves was larger than the ratio on microporous molecular sieves (SBA-15 > 10X > Y > 5A), but the difference among the adsorbents decreased with increases in pressure. On the other hand, the order of breakthrough separation factor showed the opposite result (SBA-15 < 10X < Y < 5A). The breakthrough separation factors for zeolite 10X was approximately equal to the equilibrium ratio of D<SUB>2</SUB> to H<SUB>2</SUB> at the corresponding partial pressures, whereas zeolites 5A and Y showed higher breakthrough separation factors than their equilibrium ratios. In SBA-15, the separation factors from breakthrough results were even smaller than the corresponding equilibrium ratio. In the microporous adsorbent with a limited pore size (zeolite 5A in the study), the diffusion mechanism contributed to the separation of hydrogen isotope gases as one of key factors.

식물성 기름 , 물 및 Carrageenan 의 첨가가 저지방 소세지의 물리적 특성에 미치는 영향

문점동,박구부,진상근,김영직,신택순,김영환,송또준,김용곤 경상대학교 축산진흥연구소 1996 畜産振興硏究所報 Vol.23 No.1

Vitamin D-binding protein interacts with Aβ and suppresses Aβ-mediated pathology

Moon, M,Song, H,Hong, H J,Nam, D W,Cha, M-Y,Oh, M S,Yu, J,Ryu, H,Mook-Jung, I Macmillan Publishers Limited 2013 CELL DEATH AND DIFFERENTIATION Vol.20 No.4

The level of vitamin D-binding protein (DBP) is increased in the cerebrospinal fluid of patients with Alzheimer’s disease (AD), suggesting a relationship with its pathogenesis. In this study, we investigated whether and how DBP is related to AD using several different approaches. A pull-down assay and a surface plasmon resonance binding assay indicated direct interactions between purified DBP and amyloid beta (Aβ), which was confirmed in the brain of AD patients and transgenic AD model mice by immunoprecipitation assay and immunohistochemical double-staining method. Moreover, atomic force microscopic examination revealed that DBP reduced Aβ aggregation in vitro. DBP also prevented Aβ-mediated death in cultured mouse hippocampal HT22 cell line. Finally, DBP decreased Aβ-induced synaptic loss in the hippocampus and rescued memory deficits in mice after injection of Aβ into the lateral ventricle. These results provide converging evidence that DBP attenuates the harmful effects of Aβ by a direct interaction, and suggest that DBP is a promising therapeutic agent for the treatment of AD.

플랜지가 있는 제품에서 부분패드의 영향에 관한 연구

고관영,허주환,문정효,장재석,김동윤,정민섭,김주찬,박기용,이강연,조명우,이권진,조영호,이효걸,김주호,이경희 울산과학대학 2000 연구논문집 Vol.27 No.1

본 논문에서는 기존의 Motion-JPEG 기반 감시시스템에서 낮은 동영상 압축성능 문제를 해결하기 위한 새로운 동영상 압축기법을 제안하였다. 제안된 방법에서는 현재 프레임의 JPEG 데이터 중 변화된 압축 데이터만이 실시간으로 추출하고 저장된다. 제안된 방법에 의해 저장된 데이터는 기존의 JPEG과는 다른 고유의 포맷을 가지기 때문에, 동영상 데이터는 더욱 안전하게 유지될 수 있다. 실험을 통해, 제안된 동영상 압축기법의 압축률이 기존의 Motion-JPEG 기반 감시시스템에 비해 3배정도 높다는 것을 확인할 수 있었다.

기존 교류선로의 직류변환 송전방식에 있어서 선정기법에 관한 연구

김동준(D.J. Kim),문영환(Y.H. Moon),이동일(D.I. Lee),윤재영(J.Y. Yoon),양광호(K.H. Yang) 대한전기학회 2002 대한전기학회 학술대회 논문집 Vol.2002 No.11

Synthesis and photovoltaic characterization of D/A structure compound based on N-substituted phenothiazine and benzothiadiazole

Yun, D.H.,Yoo, H.S.,Heo, S.W.,Song, H.J.,Moon, D.K.,Woo, J.W.,Park, Y.S. Korean Society of Industrial and Engineering Chemi 2013 Journal of industrial and engineering chemistry Vol.19 No.2

In this study, poly [(N-10'-dodecyl-phenothizin-3,7-ylene)-alt-(2,2'-bithiophen-5-yl)] (P1) and poly [(N-10'-dodecyl-phenothiazin-3,7-ylene)-alt-(5',6'-dioctyloxy-benzothiadiazole-bithiophene)] (P2) were synthesized by Suzuki coupling reaction. Optical and electrochemical characteristics of the synthesized polymers, P1 and P2, were then analyzed, indicating that their wavelength of maximum absorption was 453nm and 533nm, respectively, and their band-gap was 1.93eV and 1.74eV, respectively. The maximum power conversion efficiency (PCE) of organic photovoltaic cells created by using P1 and P2 were 0.74% (P1:PC<SUB>71</SUB>BM=1:4,w/w) and 1.00% (P2:PC<SUB>71</SUB>BM=1:3,w/w), respectively, and the short circuit current density (J<SUB>SC</SUB>), fill factor (FF), and open circuit voltage (V<SUB>OC</SUB>) of the device were 3.5mA/cm<SUP>2</SUP>, 31.8%, and 0.68V, respectively, for P1 and 3.9mA/cm<SUP>2</SUP>, 32.7%, and 0.78V, respectively, for P2.

Development of the new KSTAR helium distribution box

Lee, Y.J.,Kwag, S.W.,Song, N.H.,Park, D.S.,Chang, Y.B.,Moon, K.M.,Kim, N.W.,Joo, J.J.,Lee, C.H.,Kim, K.P.,Song, J.I.,Park, S.H.,Kim, H.T.,Ahn, H.J.,Kim, Y.S. Elsevier 2017 Fusion engineering and design Vol.123 No.-

<P><B>Abstract</B></P> <P>KSTAR project has required the new helium distribution box named upgraded distribution box (DBU) for the operation of the cryogenic components such as in-vessel cryo-pump (CPI), super-sonic molecular beam injector (SMBI), and deuterium pellet injection system (PIS). Two CPIs are inserted into the tokamak vacuum vessel and these components shall be operated at 90K for the liquid nitrogen thermal shields and 4.5K for the hydrogen cryo-panel. One hydrogen PIS was newly mounted on the tokamak for the 2016 KSTAR campaign. Liquid nitrogen shall be supplied to the one SMBI. For the operation of above mentioned 3 kinds of cryogenic components, a helium refrigerator, which had been used for the R&D in the KSTAR facility construction phase (2002–2013), was moved and inserted into the KSTAR 9kW helium facility room. The cooling capacity of the refrigerator at 4.5K is 1kW and it was manufactured from the Linde Kryotechnik before 2002. After some maintenances in warm compressor, electrical power supply, oil-filter, and so on, commissioning of the refrigerator up to 4.5K was accomplished successfully. From the beginning of 2015, design and fabrication of the DBU was started. It shall control the liquid nitrogen for the SMBI and CPI thermal shields whereas liquid helium for the CPI cryo-panel and PIS. To minimize the temperature of the liquid nitrogen to be supplied to SMBI and CPI, a thermal damper tank was inserted into the distribution box. Nitrogen return gases are to be warmed up to room temperature at the heater in the distribution box. A 1000l of liquid helium vessel is located nearby the PIS to supply cold gas helium (∼5K). Because the CPI cryo-panel requires regeneration up to 90K, complex regeneration and re-cool down scenario was developed and applied to the DBU. Including operational results, details of the DBU progresses will be reported in this paper.</P> <P><B>Highlights</B></P> <P> <UL> <LI> There has been progresses in the construction and 1st operation of DBU in 2016 KSTAR plasma experiments. </LI> <LI> Two in-vessel cryopumps (CPIs) cool-down to 4.5K and observed pumping speed was 3.0E4l/s. </LI> <LI> Manual CPI regeneration tests were accomplished regarding future automatic control. </LI> <LI> Production of the D<SUB>2</SUB> pellets were successful and there has been lots of injection tests. </LI> </UL> </P>

Enhanced magnetic coercivity and maximum energy product in double-perovskite Y₂CoMnO₆single crystals

Choi, H. Y.,Oh, S. H.,Moon, J. Y.,Kim, M. K.,Oh, D. G.,Lee, N.,Choi, Y. J. Wiley (John WileySons) 2015 Physica Status Solidi. Rapid Research Letters Vol.9 No.11

DRUM impactor를 이용한 대기 입자상 물질 중 원소성분의 입경분포 특성 : 제주도 고산지역의 2002년 봄철(3.29 ~ 5.30) 측정 연구 Measurements in Springtime 2002

한진석,문광주,류성윤,안준영,공부주,홍유덕,김영준 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.4

Size-segregated measurements of aerosol composition using X-stage DRUM impactor are used to determine the transport of natural and anthropogenic aerosols at Gosan site from 29 March to 30 May in 2002. Separation of ambient aerosols by DRUM impactor offers many advantages over other standard filtration techniques. Some of the most important advantages are the ability to segregate into details by particle size, to better preserve chemical integrity since the air stream doesn't pass through the deposit, to collect samples as a function of time, and to have a wide variety of impaction surfaces available to match analytical needs. Although the transport of Yellow sand is a well-known phenomenon in springtime, the result of measurement shows that not only soil dust but also anthropogenic aerosols, including sulfur, enriched trace metals such as Pb, Ni, Zn, Cu, Cr, As, Se, Hr, are transported to Gosan in springtime. This study combines the size- and time- resolved aerosol composition measurements with isentropic, backward air-mass trajectories in order to identify some potential source regions of anthropogenic aerosols. As a result, during the NYS period, the average concentration of PM_(10) was 46 ㎍/㎥. Si, Al, S, Fe, Cl, K, Ca were higher than 1,000 ㎍/㎥ and Ti was about 100 ㎍/㎥. The concentrations of Zn, Mn, Cu, Pb, Br, Rb, V, Cr, Ni, As, Se ranged between 1 and 70 ㎍/㎥. More than 50% of typical soil elements, such as Al, Si, Fe, Ca, Ti, Cr, Cu, Br, were distributed in a coarse particle range (5.0 ∼ 12μm). In other hand, anthropogenic pollutants, such as S, N, Vi, were mainly distributed in a fine particle range (0.09 ∼ 0.56μm). During the YS period, PM_(10) increased about 8 times than NYS period, and main soil elements, such as Al, Si, S, K, V, Mn, Fe also doubled in coarse particle range (1.15 ∼ 12μm). But Zn, As, Pb, Cu and Se, which distributed in the fine aerosols (0.09 ∼0.56μm), were on the same level with or decreased than NYS period. Finally, except the YS period, coarse particles (2.5 ∼ 12μm) arc inferred to be influenced by soil, coal combustion, waste incineration, ferrous and nonferrous sources through similar pathways with Yellow Sand. But line particles have different sources, such as coal combustion, gasoline vehicle, biomass burning, oil or coal combustion, nonferrous and ferrous metal sources, which are transported from China, Korea peninsula and local sources.