Local electronic structure of Mn dopants in ZnO probed by resonant inelastic x-ray scattering

Chang, G S,Kurmaev, E Z,Jung, S W,Kim, H-J,Yi, G-C,Lee, S-I,Yablonskikh, M V,Pedersen, T M,Moewes, A,Finkelstein, L D IOP Pub 2007 Journal of physics, an Institute of Physics journa Vol.19 No.27

<P>The electronic structure of Mn dopants in ZnO epitaxial thin films synthesized at different temperatures has been investigated using resonant inelastic x-ray scattering. The resulting Mn L<SUB>2,3</SUB> x-ray emission spectra of Zn<SUB>0.8</SUB>Mn<SUB>0.2</SUB>O (resonantly excited at L<SUB>2</SUB> and L<SUB>3</SUB> absorption edges) reveal different spectral features depending on the growth temperature of the films. The relative integral intensity ratio of Mn L<SUB>2</SUB> to Mn L<SUB>3</SUB> emission lines is greatly suppressed in the case of nonmagnetic Zn<SUB>0.8</SUB>Mn<SUB>0.2</SUB>O grown at 700 °C due to L<SUB>2</SUB>L<SUB>3</SUB>M<SUB>4,5</SUB> Coster–Kronig transitions. The ferromagnetic sample grown at 600 °C exhibits a normal oxide structure. The results suggest that a high growth temperature causes direct Mn–Mn bonds from the segregation of Mn atoms in ZnO. Therefore the disappearance of ferromagnetism in Mn-doped ZnO can be attributed to antiferromagnetic Mn–Mn exchange interactions due to the inhomogeneous local environment around the Mn impurities.</P>

Distribution of stress state in the Nankai subduction zone, southwest Japan and a comparison with Japan Trench

Lin, W.,Byrne, T.B.,Kinoshita, M.,McNeill, L.C.,Chang, C.,Lewis, J.C.,Yamamoto, Y.,Saffer, D.M.,Casey Moore, J.,Wu, H.Y.,Tsuji, T.,Yamada, Y.,Conin, M.,Saito, S.,Ito, T.,Tobin, H.J.,Kimura, G.,Kanagaw Elsevier Scientific Publishing Co 2016 Tectonophysics Vol.692 No.2

<P>To better understand the distribution of three dimensional stress states in the Nankai subduction zone, southwest Japan, we review various stress-related investigations carried out in the first and second stage expeditions of the Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) by the Integrated Ocean Drilling Program (IODP) and compile the stress data. Overall, the maximum principal stress sigma(l) in the shallower levels (<similar to 1 km) is vertical from near the center of forearc basin to near the trench and; the maximum horizontal stress S-Hmax (interpreted to be the intermediate principal stress sigma(2)) is generally parallel to the plate convergence vector. The exception to this generalization occurs along the shelf edge of the Nankai margin where S-Hmax, is along strike rather than parallel to the plate convergence vector. Reorientation of the principal stresses at deeper levels (e.g., >similar to 1 km below seafloor or in underlying accretionary prism) with sigma(1) becoming horizontal is also suggested at all deeper drilling sites. We also make a comparison of the stress state in the hanging wall of the frontal plate-interface between Site C0066 in the Nankai and Site C0019 in the Japan Trench subduction zone drilled after the 2011 Mw 9.0 Tohoku-Oki earthquake. In the Japan Trench, a comparison between stress state before and after the 2011 mega-earthquake shows that the stress changed from compression before the earthquake to extension after the earthquake. As a result of the comparison between the Nankai Trough and Japan Trench, a similar current stress state with trench parallel extension was recognized at both C0006 and C0019 sites. Hypothetically, this may indicate that in Nankai Trough it is still in an early stage of the interseismic cycle of a great earthquake which occurs on the decollement and propagates to the toe (around site C0006). (C) 2015 Elsevier B.V. All rights reserved.</P>

THE<i>SPITZER</i>c2d SURVEY OF NEARBY DENSE CORES. V. DISCOVERY OF A VeLLO IN THE “STARLESS” DENSE CORE L328

Lee, Chang Won,Bourke, Tyler L.,Myers, Philip C.,Dunham, Mike,Evans, Neal,Lee, Youngung,Huard, Tracy,Wu, Jingwen,Gutermuth, Robert,Kim, Mi-Ryang,Kang, Hyun Woo IOP Publishing 2009 The Astrophysical journal Vol.693 No.2

서울시 지하철 구내의 공기중 분진 농도에 관한 연구

백남원(N.W. Paik),박두용(D.Y. Park),장익선(I.S. Chang),신용철(Y.C. Shin),이정인(J. l. Lee) 한국환경보건학회 1988 한국환경보건학회지 Vol.14 No.2

Airborne dust and asbestos fiber concentrations were determined in subway stations located in Seoul area. Two stations, such as Eulchiro 4.Ka Station of Une #2, constructed during a period of 1980-1984 and Hyehwa Station of Une #4, opened in 1985, were selected. The results of the study are as follows. 1. Daily tirne.weighted average (1W A) concentrations of airborne dusts from 07:00 to 20:00 hours in Line #2 and μne #4 were 0.43:t0.08 mg/m3 and 0.37:t0.12 mg/m3 , respectively. Thus, the dust levels in Líne #2 were significant1y higher than the levels in Line #4( p < 0.05). 2. Dust levels in the morning (07:00-11:00 hours), noon (1 1:00-16:00 hours) and in the evening (1 6:00-20:00 hours) in Líne #2 were 0.47:t0.17 mgjm3 , 0.37:t0.08 mg/m3 , and 0.46土0.07 mg/m3 respectively. Thus, dust levels in the morning and evening (i.e., during rush hours) were significantly higher than levels in the noon ( p < 0.02). However, there was no such difference in dust levels by time in Líne #4. 3. Airborne total dust concentrations were well below the occupational health standard of 10 mg/m3 , however, the levels were exceeding the ambient air standard recommended by the Korean Environment Administration. 4. All of airborne asbestos fiber concentrations were equal to or below 0.005 fibers/cc. The levels are within both occupational health standards and U .S. EPA criterìa. 5. A consideration should be given to the improvements of c1eaning methods (such as use of vacuum c1eaning instead of brushing) and the existing ventilation (such as more aìr change and filtration of supply air) for a reduction of dust levels. 6. It is recommended that routine monitoring of aìrborne dusts and asbestos fibers be conducted because more dusts and asbestos fibers can be produced in the aìr due to the deterioration of facilities by age and water damage in future.

Anti-nuclear antibody reactivity in lupus may be partly hard-wired into the primary B-cell repertoire

Chang, S.,Yang, L.,Moon, Y.M.,Cho, Y.G.,Min, S.Y.,Kim, T.J.,Kim, Y.J.,Patrick, W.,Kim, H.Y.,Mohan, C. Pergamon Press 2009 Molecular immunology Vol.46 No.16

When monoclonal ANAs and non-ANAs generated from a genetically simplified mouse model of lupus, B6.Sle1, were recently compared, the ANAs exhibited three sequence motifs in their immunoglobulin heavy chains, including increased cationicity in CDR3 (''motif A''), reduced anionicity in CDR2 (''motif B'') and increased aspartate at H50 (''motif C''). The present study was designed to elucidate the extent to which these ANA-associated sequence motifs might be hard-wired into the primary B-cell repertoire in lupus. The immunoglobulin heavy chain sequence of total splenic B-cells, follicular B-cells and marginal zone B-cells from B6.Sle1 congenic mice and C57BL/6 controls were amplified by single-cell PCR and compared. Analysis of the primary immunoglobulin heavy chain repertoire indicated that the first two sequence motifs ''A'' and ''B'' were already encoded in the naive repertoire of B6.Sle1<SUP>z</SUP> mice, whereas the third motif ''C'' was introduced in part by somatic mutation. Site-directed mutagenesis confirmed that non-anionic CDR2 and cationic CDR3 residues in the immunoglobulin heavy chain facilitated nuclear antigen binding in concert, whereas aspartate at H50 strongly vetoed DNA-binding, while preserving nucleosome reactivity. Hence, anti-nuclear antibodies appear to arise as a consequence of two distinct processes-genetically programmed selection of specific CDR charge motifs into the primary immunoglobulin repertoire, with secondary contribution from somatic mutation. Polymorphisms in the lupus susceptibility gene Ly108 that impair central B-cell tolerance may be mechanistically responsible for these early repertoire differences in lupus.

The X-Pt(X=Ge, Cr) Underlayer Thickness Effect on Magnetic Properties of L1₀ FePt Films

J. L. Tsai,Y. C. Lin,C. J. Hsu,C. W. Hsu,S. K. Chen,W. C. Chang 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Assessment of transboundary ozone contribution toward South Korea using multiple source-receptor modeling techniques

Choi, K.C.,Lee, J.J.,Bae, C.H.,Kim, C.H.,Kim, S.,Chang, L.S.,Ban, S.J.,Lee, S.J.,Kim, J.,Woo, J.H. Pergamon Press ; Elsevier [distribution] 2014 Atmospheric environment Vol.92 No.-

Ozone concentrations in East Asia were simulated using the Community Multi-scale Air Quality (CMAQ) model, and its source contributions were estimated by multiple source-receptor modeling techniques. To study relationships between ozone concentrations and precursor emission sources, three approaches were applied to four months (January, April, July, and October 2009) to represent seasonal characteristics and compare results, with a particular focus on South Korea. Brute force (BF) is a traditional sensitivity analysis method used to estimate model output response to an input change. The high-order decoupled direct method (HDDM), a computational method, is an efficient and accurate alternative to the BF method for sensitivity. The Ozone and Particulate Precursor Tagging Methodology (OPTM) provides contribution information quantified by tracking emissions from selected sources throughout the simulation period. The approaches generally show that most of the receptor regions were substantially influenced by emissions from central China, which is the largest anthropogenic emissions source region in East Asia. Local emissions were still major contributors, especially South Korea and Japan during July 2009. On the other hand, a case study of maximum 8-h ozone concentrations derived from CMAQ-OPTM on April 9 in South Korea shows that the NO<SUB>x</SUB> and VOCs emissions from China contributed approximately 82% and 91%, respectively, to maximum 8-h ozone in Region 4 (South Korea) without boundary inflow, which indicates that Chinese emissions are the dominant contributor in this episode. A comparison study of the three approaches shows that HDDM tends to estimate biogenic source contributions lower than that from OPTM in China but similar to OPTM in South Korea and Japan. When comparing the BF method and HDDM, the sensitivity results show a reasonably good agreement during a given period. The location- and time-dependent maximum 8-h ozone isopleths over South Korea as a receptor region created by HDDM suggest that most ozone was being transported from central China, whereas almost no ozone was formed locally during April 2009, and local conditions were heavily VOC limited. On the other hand, local emissions were the dominant contributor during July 2009, and every source region showed a NO<SUB>x</SUB>-limited regime, which indicates that ozone concentrations in South Korea strongly depend on NO<SUB>x</SUB> emissions during this month.

Magnetic Properties and Microstructure of Nano-grain L1₀ FePt(200) Films

An-Cheng Sun,F.T. Yuan,H.W. Chang,P.C. Kuo,S.C. Chen,C.T. Lee,Jen-Hwa Hsu,H. L. Huang 한국자기학회 2007 한국자기학회 학술연구발표회 논문개요집 Vol.- No.-

Multiple model approach to evaluation of accelerated carbonation for steelmaking slag in a slurry reactor

Pan, S.Y.,Liu, H.L.,Chang, E.E.,Kim, H.,Chen, Y.H.,Chiang, P.C. Pergamon Press 2016 CHEMOSPHERE - Vol.154 No.-

Basic oxygen furnace slag (BOFS) exhibits highly alkaline properties due to its high calcium content, which is beneficial to carbonation reaction. In this study, accelerated carbonation of BOFS was evaluated under different reaction times, temperatures, and liquid-to-solid (L/S) ratios in a slurry reactor. CO<SUB>2</SUB> mass balance within the slurry reactor was carried out to validate the technical feasibility of fixing gaseous CO<SUB>2</SUB> into solid precipitates. After that, a multiple model approach, i.e., theoretical kinetics and empirical surface model, for carbonation reaction was presented to determine the maximal carbonation conversion of BOFS in a slurry reactor. On one hand, the reaction kinetics of BOFS carbonation was evaluated by the shrinking core model (SCM). Calcite (CaCO<SUB>3</SUB>) was identified as a reaction product through the scanning electronic microscopy and X-ray diffraction analyses, which provided the rationale of applying the SCM in this study. The rate-limiting step of carbonation was found to be ash-diffusion controlled, and the effective diffusivity for carbonation of BOFS in a slurry reactor were determined accordingly. On the other hand, the carbonation conversion of BOFS was predicted by the response surface methodology (RSM) via a nonlinear mathematical programming. According to the experimental data, the highest carbonation conversion of BOFS achieved was 57% under an L/S ratio of 20 mL g<SUP>-1</SUP>, a CO<SUB>2</SUB> flow rate of 0.1 L min<SUP>-1</SUP>, and a pressure of 101.3 kPa at 50 <SUP>o</SUP>C for 120 min. Furthermore, the applications and limitations of SCM and RSM were examined and exemplified by the carbonation of steelmaking slags.

씻지 않는 쌀의 가공 공정 개발(Ⅰ) : 질량수지 분석 Mass Balance Analysis

장동일,한우석,김동칠,이상효 한국농업기계학회 1999 바이오시스템공학 Vol.24 No.4