Fluidization behaviors of different types of multi-walled carbon nanotubes in gas-solid fluidized beds

Jeong, S.W.,Lee, J.H.,Kim, J.,Lee, D.H. Korean Society of Industrial and Engineering Chemi 2016 Journal of industrial and engineering chemistry Vol.35 No.-

<P>The fluidization behaviors of different types of multi-walled carbon nanotubes (MWCNTs) were investigated in a fluidized bed with a 0.14 m-ID x 2.4 m-height Plexiglas column. Four types of MWCNTs were used as the bed materials: (i) N refers to the NC7000 (TM) prepared by Nanocyl (R), (ii) S-f refers to the agglomerate by which fine entangled MWCNTs were agglomerated by strong cohesive force such as van der Waals force, (iii) S-c refers to the coarse entangled MWCNTs with a shape such as a single particle, (iv) S-mix refers to the binary mixture of Se and S-c physically mixed in a 1:1 volumetric ratio. For N and S-f, the fluidization behavior with superficial gas velocity is similar to that of Geldart's group A particles. In the bubbling fluidization of N and S-f no bubbles were observed. The minimum fluidizing gas velocity and bed expansion ratio of S-f was higher than those of N. The fluidization behavior of S-c was similar to that shown by the results from Geldart's group B with a wide size distribution. For the binary mixture, S-f and S-c are the flotsam and jetsam, respectively. The fluidization behavior of Smix was divided into four regions with decreasing superficial gas velocity. S-c and S-f were not mixed sufficiently at high velocity due to the high bed expansion ratio of S-f. As the superficial gas velocity was decreased, S-c gradually became defluidized. When S-c, had a fixed bed at the bottom, S-f showed particulate fluidization at the top. At this point, S-c and S-f were completely segregated. The variation in the pressure drop across the beds at the superficial gas velocity was similar to that for the S-c; however, the bed expansion was similar to that for the S-f. (C) 2015 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.</P>

<i>S100A9</i> and <i>EGFR</i> gene signatures predict disease progression in muscle invasive bladder cancer patients after chemotherapy

Kim, W. T.,Kim, J.,Yan, C.,Jeong, P.,Choi, S. Y.,Lee, O. J.,Chae, Y. B.,Yun, S. J.,Lee, S. C.,Kim, W. J. Oxford University Press 2014 Annals of Oncology Vol.25 No.5

<P>In our previous gene expression profile analysis, IL1B, S100A8, S100A9, and EGFR were shown to be important mediators of muscle invasive bladder cancer (MIBC) progression. The aim of the present study was to investigate the ability of these gene signatures to predict disease progression after chemotherapy in patients with locally recurrent or metastatic MIBC. Patients with locally advanced MIBC who received chemotherapy were enrolled. The expression signatures of four genes were measured and carried out further functional analysis to confirm our findings. Two of the four genes, S100A9 and EGFR, were determined to significantly influence disease progression (P = 0.023, 0.045, respectively). Based on a receiver operating characteristic curve, a cut-off value for disease progression was determined. Patients with the good-prognostic signature group had a significantly longer time to progression and cancer-specific survival time than those with the poor-prognostic signature group (P < 0.001, 0.042, respectively). In the multivariate Cox regression analysis, gene signature was the only factor that significantly influenced disease progression [hazard ratio: 4.726, confidence interval: 1.623-13.763, P = 0.004]. In immunohistochemical analysis, S100A9 and EGFR positivity were associated with disease progression after chemotherapy. Protein expression of S100A9/EGFR showed modest correlation with gene expression of S100A9/EGFR (r = 0.395, P = 0.014 and r = 0.453, P = 0.004). Our functional analysis provided the evidence demonstrating that expression of S100A9 and EGFR closely associated chemoresistance, and that inhibition of S100A9 and EGFR may sensitize bladder tumor cells to the cisplatin-based chemotherapy. The S100A9/EGFR level is a novel prognostic marker to predict the chemoresponsiveness of patients with locally recurrent or metastatic MIBC.</P>

대두박 수준을 달리한 사료내 미생물 PHYTASE 의 첨가가 잉어의 성장 및 인 배설량에 미치는 영향

김광석(K . S . Kim),김정대(J . D . Kim),송재성(J . S . Song),정관식(K . S . Jeong),우영배(Y . B . Woo) 한국영양사료학회 1996 韓國營養飼料學會誌 Vol.20 No.5

세관 양광주 방전에서 플라즈마 확산의 완전 해

김동준,정종문,김정현,황하청,정재윤,조윤희,임현교,구제환,최은하,조광섭,Jin, D.J.,Jeong, J.M.,Kim, J.H.,Hwang, H.C.,Chung, J.Y.,Cho, Y.H.,Lim, H.K.,Koo, J.H.,Choi, E.H.,Cho, G.S. 한국진공학회 2010 Applied Science and Convergence Technology Vol.19 No.1

관경이 수 mm인 세관 램프 내부에서 플라즈마의 확산을 조사하기 위하여 이극성(ambipolar) 확산방정식을 해하였다. 반경 방향의 확산에 의한 유리관 벽에서의 플라즈마 소멸 특성시간은 $\tau_r\;=\;(r_0/2.4)^2/D_a$로 주어진다. 반경 $r_0{\sim}1\;mm$이고 이극성 확산계수 $D_a{\sim}0.01\;m^2/s$ 이면, $\tau_r{\sim}17\;{\mu}s$이다. 이는 램프의 교류전원 구동에서 플라즈마를 유지하기 위한 구동 최소 주파수 ~30 kHz에 해당한다. 고전압이 인가되는 전극부에 발생한 고밀도의 플라즈마가 양광주로 확산되는 특성시간은 $\tau_z{\sim}0.1\;s$이다. 고밀도 플라즈마 경계에서의 시간에 대한 확산속도는 $t{\sim}10^{-6}\;s$일 때 $u_D{\sim}10^2\;m/s$이고, $t{\sim}10^{-3}\;s$이면 그 속도는 $u_D{\sim}1\;m/s$로 느려진다. 따라서 램프 길이 ~1 m에 대하여 전극부에서 생성된 고밀도 플라즈마가 양광주 전체로 확산되는 시간은 수 초가 걸린다. The ambipolar diffusion equation has been solved in a fine-tube lamp of a few mm in diameter. In the diffusion of radial direction, the plasma diffuses and vanishes away at the glass wall by recombination with the characteristic time of plasma loss is given by $\tau_r\;=\;(r_0/2.4)^2/D_a$. With the radius $r_0{\sim}1\;mm$ and the ambipolar diffusion coefficient $D_a{\sim}0.01\;m^2/s$, the vanishing time is calculated $\tau_r{\sim}10\;{\mu}s$ which corresponds to the least value of frequency 30 kHz for the sustaining the plasma in the operation of high voltage AC-power. In the diffusion of longitudinal z-direction, a high density plasma generated at the area of a high voltage electrode, diffuses into the positive column with the characteristic time $\tau_z{\sim}0.1\;s$. The plasma diffusion velocity at the boundary of high density plasma is $u_D{\sim}10^2\;m/s$ at the time $t{\sim}10^{-6}$ s and the diffusion velocity becomes slow as $u_D{\sim}1\;m/s$ at $t{\sim}10^{-3}\;s$. Therefore, for the long lamp of 1 m, it takes about several seconds for the high density plasma at the area of electrode to diffuse through the whole positive column space.

Associations between CYP2A6 polymorphisms and outcomes of adjuvant S-1 chemotherapy in patients with curatively resected gastric cancer

Jeong, J. H.,Park, S. R.,Ahn, Y.,Ryu, M. H.,Ryoo, B. Y.,Kong, S. Y.,Yook, J. H.,Yoo, M. W.,Kim, B. S.,Kim, B. S. Springer Science + Business Media 2017 GASTRIC CANCER Vol.20 No.1

<P>CYP2A6 polymorphisms are not associated with toxicity of S-1 chemotherapy, but correlate with the efficacy of S-1 in the adjuvant setting for gastric cancer.</P>

A colloidal system of polythiophene-grafted edge-gold-coated silver nanoprisms with enhanced optical properties and stability

Jeong, S.,Lee, D.,Kim, J.,Jang, D. J. Royal Society of Chemistry 2017 NEW JOURNAL OF CHEMISTRY Vol.41 No.1

<P>Silver nanoprisms (Ag-PRs) have been epitaxially edge-coated with gold and subsequently covered fully with P3HT chains to fabricate poly(3-hexylthiophene)-grafted edge-gold-coated silver nanoprisms (P3HT@AuAg-PRs) which are miscible with organic solvents; each AuAg-PR with a typical edge length of 122 nm is surrounded by 4.4 x 10(3) P3HT chains. Both absorption and emission spectra have indicated that aggregated P3HT chains are bound on the surfaces of noble-metal nanoprisms. Picosecond emission kinetic profiles have suggested that the S-1 relaxation time of P3HT in P3HT@AuAg-PRs is reduced due to energy transfer to AuAg-PRs. From nanosecond transient-absorption kinetic profiles, the reduced amplitude and the increased decay time of T-1 excitons in P3HT@AuAg-PRs have been measured, indicating that neither the intersystem crossing of S-1 into T-1 nor the intersystem crossing of T-1 into S-0 occurs effectively in P3HT@AuAg-PRs owing to the stretched and rigid conformations of P3HT chains bound on the surfaces of AuAg-PRs. The surface-enhanced Raman scattering effect of P3HT@AuAg-PRs is as high as 4.6 because the sharp tips of AuAg-PRs which are maintained via gold coating serve as 'hot spots''. The morphology deformation time of P3HT@AuAg-PRs in H2O2(aq) has been extended 48 times longer than that of Ag-PRs. Overall, our fabricated nanocomposites of P3HT@AuAg-PRs not only have feasible-process ability but also possess enhanced optical properties and high stability against oxidizing agents, extending the use of noble-metal nanoprisms for various optical applications.</P>

Directly drawn ZnO semiconductors and MWCNT/PSS electrodes via electrohydrodynamic jet printing for use in thin-film transistors: The ideal combination for reliable device performances

Jeong, Y.J.,Bae, J.,Nam, S.,Lim, S.,Jang, J.,Kim, S.H.,Park, C.E. Elsevier Science 2016 ORGANIC ELECTRONICS Vol.39 No.-

Solution-processed deposition of conducting and semiconducting materials enables the fabrication of large-area and low-cost electronic devices without the use of high-vacuum equipment. To obtain the possibility of commercializing solution-processed devices such as thin-film transistors (TFTs), easy and simple patterning process of each component become an important issue. In this study, we prepare directly patterned semiconductors and electrodes with the electrohydrodynamic (EHD) printing technique and utilize them in reliable n-type TFTs. By utilizing EHD printing technique, straight lines of zinc oxide (ZnO) semiconductor are successfully drawn from the highly soluble precursor, zinc acrylate (ZnA), and used as the active layers of TFTs. The resulting devices exhibit good TFT characteristics, and doping with a small amount of indium can enhance their performances. Furthermore, we print three different conducting materials on pre-patterned ZnO substrates for the realization of ZnO TFT arrays consisting of directly-drawn semiconductors and source/drain (S/D) electrodes. Multiwall carbon nanotube/polystyrene sulfonate (MWCNT/PSS) electrodes are found to form stable lines and their solution-processed TFTs display reliable operation with negligible hysteresis.

Gentamicin-intercalated smectite as a new therapeutic option for Helicobacter pylori eradication

Jeong, S. J.,Kim, J. H.,Jung, D. H.,Lee, K. H.,Park, S. Y.,Song, Y.,Kang, I. M.,Song, Y. G. Oxford University Press 2018 The Journal of antimicrobial chemotherapy Vol.73 No.5

<P>Conclusions: These results suggest that S-GEN is a promising and effective therapeutic agent for the treatment of H. pylori infection.</P>

Relationship Between Sulfide Capacity and Structure of MnO-SiO2-Al2O3-Ce2O3 System

Jeong, S. J.,Kim, T. S.,Park, J. H. Minerals, Metals & Materials Society 2017 Metallurgical and materials transactions. B, Proce Vol.48 No.1

<P>Sulfide capacity of the MnO-SiO2-Al2O3-Ce2O3 system was measured at 1873 K (1600 A degrees C), and the structural analysis was carried out using micro-Raman spectroscopy to understand the role of Ce2O3 in the sulfur dissolution behavior. Sulfide capacity of the basic melts (MnO/SiO2 = 2.2(+/- 0.14)) decreased with increasing content of Ce2O3 to approx. 4 mol pct, beyond which it increased. Sulfide capacity continuously decreased in the less basic system (MnO/SiO2 = 1.0(+/- 0.15)), whereas it was hardly affected by Ce2O3 in the relatively acidic composition (MnO/SiO2 = 0.3(+/- 0.05)). There was a significant increase in the intensity of Raman band at 600 cm(-1) by Ce2O3 addition in high MnO/SiO2 (=2.2) system, which originated from the transition from [(Al,Mn-0.5)O-4]-tetrahedron to [(Al,Ce)O-6]-octahedron due to strong attraction between Al2O3 and Ce2O3. Combining thermodynamic and structural information, the effect of Ce2O3 on the sulfide capacity of Mn-aluminosilicate melts can be explained by the following factors: (1) Activity of MnO in the melts decreased by addition of Ce2O3; (2) Free oxygen was consumed in the structure modification from [(Al,Mn-0.5)O-4] to [(Al,Ce)O-6] unit by addition of Ce2O3; and 3) When the Ce3+ content was greater than critical value (approx. 4 mol pct) in high MnO/SiO2 (=2.54) melts, excess Ce3+ and Mn2+ ions competitively reacted with S2- ions, resulting in an increase of sulfide capacity. (C) The Minerals, Metals & Materials Society and ASM International 2016</P>

Plastic influence functions for calculating J-integral of complex-cracks in pipe

Jeong, J.U.,Choi, J.B.,Kim, M.K.,Huh, N.S.,Kim, Y.J. Applied Science Publishers ; Elsevier Science Ltd 2016 The International journal of pressure vessels and Vol.146 No.-

<P>this study, the plastic influence functions, h(1), for estimates off-integral of a pipe with a complex crack were newly proposed based on the systematic 3-dimensional (3-D) elastic-plastic finite element (FE) analyses by using Ramberg-Osgood (R-O) relation, in which global bending moment, axial tension and internal pressure were considered as loading conditions. Based on the present plastic influence functions, the GE/EPRI-type J-estimation scheme for complex-cracked pipes was suggested, and the results from the proposed pestimation were compared with the FE results using both R-O fit parameters and actual tensile data of SA376 TP304 stainless steel. The comparison results demonstrate that although the proposed scheme provided sensitive J estimations according to fitting ranges of R-O parameters, it showed overall good agreements with the FE results using R-O relation. Thus, the proposed engineering.] prediction method can be utilized to assess instability of a complex crack in pipes for R-O material. (C) 2016 Elsevier Ltd. All rights reserved.</P>