Hub 자동용접시스템 개발

김인환,허남수,양상국 진주산업대학교 산업과학기술연구소 2004 산업과학기술연구소보 Vol.- No.11

It is very important to development of Auto-Welding system in manufacturing industry because of some difficult conditions. In this thesis, the manufacturing process of the Hub welding system was analyzed schematically. The overall assembling process was programmed the design procedure using the Master-k language. The effectiveness of the proposed auto-welding system is assured through experiment.

A band-gap-graded CZTSSe solar cell with 12.3% efficiency

Yang, K. J.,Son, D. H.,Sung, S. J.,Sim, J. H.,Kim, Y. I.,Park, S. N.,Jeon, D. H.,Kim, J.,Hwang, D. K.,Jeon, C. W. Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.26

<P>Although Cu2ZnSn(S,Se)(4) (CZTSSe) has attracted attention as an alternative to CuInGaSe2 (CIGS) as an absorber material in solar cells, its low efficiency is a serious shortcoming preventing its commercialization. To realize a high-efficiency CZTSSe solar cell, improved grain crystallinity, inhibited secondary-phase formation, controlled defect generation, adequate Na content, and band gap grading are required in the absorber layer. Few studies have focused specifically on band gap grading. In this study, a method of using SeS2, a new potential chalcogenization source material, to control the S and Se contents in a CZTSSe absorber and its effects were investigated. Using an appropriate SeS2/Se weight ratio, band gap grading was realized within the depletion region. By increasing the value of V-OC through band gap grading in the depletion region, a record V-OC deficit of 0.576 V was achieved. Furthermore, the possibility of enhancing JSC through the formation of a type-inverted n-type phase at the absorber surface in response to an appropriate alignment of the conduction-band minimum energy level and the Fermi energy pinning level is discussed. By introducing the chalcogenization source material SeS2 during the annealing process, CZTSSe solar cells with a maximum efficiency of 12.3% were obtained.</P>

Photoluminescence Investigation of Thick GaN Films Grown on Si Substrates by Hydride Vapor Phase Epitaxy

M.Yang,H.S.Ahn,J.H.Chang,S.N.Yi,K.H.Kim,H.Kim,김석환 한국물리학회 2003 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.43 No.6

The optical properties of thick GaN lms grown by hydried vapor phase epitaxy (HVPE) using a low-temperature intermediate GaN buer layer grown on a (111) Si substrate with a ZnO thin lm were investigated by using photoluminescence (PL) measurement at 300 K and 77 K. The strong donor bound exciton (DBE) at 357 nm with a full width at half maximum (FWHM) of 15 meV was observed at 77 K. The value of 15 meV is extremely narrow for GaN grown on Si substrate by HVPE. An impurity-related peak was also observed at 367 nm. The origin of impurity was investigated using Auger spectroscopy.

낮은 접촉저항을 갖는 Ni/Si/Ni n형 4H-SiC의 오옴성 접합

金昌敎(C. K. Kim),梁性俊(S. J. Yang),趙南仁(N. I. Cho),兪弘鎭(H. J. Yoo) 대한전기학회 2004 전기학회논문지C Vol.53 No.10

Mammalian Systems Biotechnology Reveals Global Cellular Adaptations in a Recombinant CHO Cell Line

Yusufi, F.N.K.,Lakshmanan, M.,Ho, Y.S.,Loo, B.L.W.,Ariyaratne, P.,Yang, Y.,Ng, S.K.,Tan, T.R.M.,Yeo, H.C.,Lim, H.L.,Ng, S.W.,Hiu, A.P.,Chow, C.P.,Wan, C.,Chen, S.,Teo, G.,Song, G.,Chin, J.X.,Ruan, X. Cell Press 2017 Cell systems Vol.4 No.5

Effective development of host cells for therapeutic protein production is hampered by the poor characterization of cellular transfection. Here, we employed a multi-omics-based systems biotechnology approach to elucidate the genotypic and phenotypic differences between a wild-type and recombinant antibody-producing Chinese hamster ovary (CHO) cell line. At the genomic level, we observed extensive rearrangements in specific targeted loci linked to transgene integration sites. Transcriptional re-wiring of DNA damage repair and cellular metabolism in the antibody producer, via changes in gene copy numbers, was also detected. Subsequent integration of transcriptomic data with a genome-scale metabolic model showed a substantial increase in energy metabolism in the antibody producer. Metabolomics, lipidomics, and glycomics analyses revealed an elevation in long-chain lipid species, potentially associated with protein transport and secretion requirements, and a surprising stability of N-glycosylation profiles between both cell lines. Overall, the proposed knowledge-based systems biotechnology framework can further accelerate mammalian cell-line engineering in a targeted manner.

Growth of Epitaxial MgB₂ Thick Films with Columnar Structures by Using HPCVD

Seong, W. K.,Huh, J. Y.,Kang, W. N.,Kim, J.-W.,Kwon, Y.-S.,Yang, N.-K.,Park, J.-G. Wiley - VCH 2007 CHEMICAL VAPOR DEPOSITION -WEINHEIM- Vol.13 No.12

<P>Epitaxial MgB<SUB>2</SUB> thick films are grown on Al<SUB>2</SUB>O<SUB>3</SUB> substrates at 600 °C by using the hybrid physical (HP)CVD technique. In order to obtain a high magnesium vapor pressure around the substrates, we use a special susceptor having a susceptor cap and achieve a very high growth rate of 0.17 &mgr;m min<SUP>–1</SUP>. Hexagonal-shaped columnar structures are observed by cross-sectional and planar-view transmission electron microscope (TEM) images. For the 1.7 &mgr;m thick film, the T<SUB>c</SUB> is observed to be 40.5 K with a J<SUB>c</SUB> of 1.5 × 10<SUP>6</SUP> A cm<SUP>–2</SUP> at 30 K. The vortex pinning mechanism by intercolumnar boundaries will be discussed.</P> <B>Graphic Abstract</B> <P>By using novel HPCVD technique with a special susceptor and a susceptor cap, epitaxial MgB<SUB>2</SUB> thick films with columnar structures are successfully fabricated at low temperatures (below 600 °C). The susceptor cap significantly enhances the local magnesium vapor pressure around the substrates so that a very high growth rate of 0.17 &mgr;m/min could be achieved. For the 1.7-&mgr;m-thick film, the T<SUB>c</SUB> was observed to be 40.5 K.</P>

Crystal structure of Rv2258c from Mycobacterium tuberculosis H37Rv, an S-adenosyl-l-methionine-dependent methyltransferase

Im, H.N.,Kim, H.S.,An, D.R.,Jang, J.Y.,Kim, J.,Yoon, H.J.,Yang, J.K.,Suh, S.W. Academic Press 2016 Journal of structural biology Vol.193 No.3

<P>The Mycobacterium tuberculosis Rv2258c protein is an S-adenosyl-L-methionine (SAM)-dependent methyltransferase (MTase). Here, we have determined its crystal structure in three forms: a ligand-unbound form, a binary complex with sinefungin (SFG), and a binary complex with S-adenosyl-L-homocysteine (SAH). The monomer structure of Rv2258c consists of two domains which are linked by a long alpha-helix. The N-terminal domain is essential for dimerization and the C-terminal domain has the Class I MTase fold. Rv2258c forms a homodimer in the crystal, with the N-terminal domains facing each other. It also exists as a homodimer in solution. A DALI structural similarity search with Rv2258c reveals that the overall structure of Rv2258c is very similar to small-molecule SAM -dependent MTases. Rv2258c interacts with the bound SFG (or SAH) in an extended conformation maintained by a network of hydrogen bonds and stacking interactions. Rv2258c has a relatively large hydrophobic cavity for binding of the methyl-accepting substrate, suggesting that bulky nonpolar molecules with aromatic rings might be targeted for methylation by Rv2258c in M. tuberculosis. However, the ligand-binding specificity and the biological role of Rv2258c remain to be elucidated due to high variability of the amino acid residues defining the substrate-binding site. (C) 2016 Elsevier Inc. All rights reserved.</P>

Effect of BSO addition on Cu-O bond of GdBa₂Cu₃O_7-x films with varying thickness probed by extended x-ray absorption fine structure

Jeon, H.K.,Lee, J.K.,Yang, D.S.,Kang, W.N.,Kang, B. The Korea Institute of Applied Superconductivity a 2016 한국초전도저온공학회논문지 Vol.18 No.4

We investigated the relation between the Cu-O bond length and the superconducting properties of $BaSnO_3$ (BSO)-added $GdBa_2Cu_3O_{7-x}$ (GdBCO) thin films by using extended x-ray absorption fine structure (EXAFS) spectroscopy. 4 wt.% $BaSnO_3$ (BSO) added $GdBa_2Cu_3O_{7-x}$ (GdBCO) thin films with varying thickness from $0.2{\mu}m$ to $1.0{\mu}m$ were fabricated by using pulsed laser deposition (PLD) method. The transition temperature ($T_c$) and the residual resistance ratio (RRR) of the GdBCO films increased with increasing thickness up to $0.8{\mu}m$, where the crystalline BSO has the highest peak intensity, and then decreased. This uncommon behaviors of $T_c$ and RRR are likely to be created by the addition of BSO, which may change the ordering of GdBCO atomic bonds. Analysis from the Cu K-edge EXAFS spectroscopy showed an interesting thickness dependence of ordering behavior of BSO-added GdBCO films. It is noticeable that the ordering of Cu-O bond and the transition temperature are found to show opposite behaviors in the thickness dependence. Based on these results, the growth of BSO seemingly have evident effect on the alteration of the local structure of GdBCO film.

Microwave losses of undoped n-type silicon and undoped 4H-SiC single crystals at cryogenic temperatures

Jung, H. S.,Yang, W. I.,Cho, M. S.,Joo, K. N.,Lee, S. Y. SPRINGER SCIENCE AND BUSINESS MEDIA 2014 ELECTRONIC MATERIALS LETTERS Vol.10 No.3

We investigated microwave losses of single-crystalline Si and 4H-SiC at cryogenic temperatures at 8.6-24 GHz using a method involving a dielectric resonator with high-T (c) superconductor YBa2Cu3O7-delta films used to improve the measurement sensitivity. The loss tangent of our undoped n-type Si appeared to be extremely low at temperatures below 20 K with a value of 1 x 10(-6) at 24 GHz at 10 K, which is more than 100 times lower than the value of 2 x 10(-4) at 6.8 GHz at 10 K reported by Krupka et al. [IEEE Trans. Microw. Theory Tech. 54, 3995 (2006)] for undoped p-type Si. Meanwhile, the loss tangent of pristine 4H-SiC appeared to be very high with a value of 0.01 at 10 K at 8.6 GHz, which is 4000 times higher than that of our undoped Si. When the pristine 4H-SiC was irradiated with thermal neutrons, the loss tangent was enhanced by seven times due to the significantly reduced electrical resistivity. Our results show that, at temperatures below 20 K, the loss tangent of undoped n-type Si is low enough for various cryogenic applications and that thermal neutron irradiation could provide a useful means of reducing the electrical resistivity of SiC possibly by means of neutron transmutation doping.

원발성 간암에서 PIVKA-II 및 Lens Culinaris Agglutinin-A 반응성 Alpha-fetoprotein(AFP-L3)의 임상적 유용성

배시현,박두호,양진모,박영민,차상복,최종영,성광용,조세현,정규원,선희식,김부성,최상욱,변병훈,한남익 대한간학회 2000 Clinical and Molecular Hepatology(대한간학회지) Vol.6 No.2

Background/Aims: Des-γ-carboxy prothrombin(DCP), a protein induced by vitamin K absence or antagonist-II(PIVKA-II), and Lens culinaris agglutinin-A reactive AFP-L3 have been reported to be useful markers for the diagnosis of hepatocellular carcinoma (HCC). In the present study, both the PIVKA-II and AFP-L3 were analyzed and compared with a conventional AFP to determine its usefulness, specificity and sensitivity in the diagnosis of HCC. Methods: Sera were collected from 108 patients consisting of 17 patients with chronic hepatitis, 22 patients with liver cirrhosis and 69 patients with HCC. The AFP-L3 was determined by an lectin affinity electrophoresis coupled with an antibody-affinity blotting. Level of DCP was measured by an enzyme immunoassay with an anti-DCP monoclonal antibody. Results: The sensitivity and specificity of PIVKA-II and AFP L3 were 49.3% and 89.5%, and 32.5% and 85.7%, respectively. No significant correlation was found between the PIVKA-II or AFP L3 and serum AFP. No correlation was found etween the PIVKA-II or AFP L3 and the characteristics of HCC. Conclusion: The determination of plasma DCP and AFP L3 levels combined with AFP levels may be useful especially for the differential diagnosis between HCC and chronic liver diseases without HCC.(Korean J HepatoBackground/Aims: Des-γ-carboxy prothrombin(DCP), a protein induced by vitamin K absence or antagonist-II(PIVKA-II), and Lens culinaris agglutinin-A reactive AFP-L3 have been reported to be useful markers for the diagnosis of hepatocellular carcinoma (HCC). In the present study, both the PIVKA-II and AFP-L3 were analyzed and compared with a conventional AFP to determine its usefulness, specificity and sensitivity in the diagnosis of HCC. Methods: Sera were collected from 108 patients consisting of 17 patients with chronic hepatitis, 22 patients with liver cirrhosis and 69 patients with HCC. The AFP-L3 was determined by an lectin affinity electrophoresis coupled with an antibody-affinity blotting. Level of DCP was measured by an enzyme immunoassay with an anti-DCP monoclonal antibody. Results: The sensitivity and specificity of PIVKA-II and AFP-L3 were 49.3% and 89.5%, and 32.5% and 85.7%, respectively. No significant correlation was found between the PIVKA-II or AFP-L3 and serum AFP. No correlation was found etween the PIVKA-II or AFP L3 and the characteristics of HCC. Conclusion: The determination of plasma DCP and AFP-L3 levels combined with AFP levels may be useful especially for the differential diagnosis between HCC and chronic liver diseases without HCC.(Korean J Hepatol 2000;6:205-214)l 2000;6:205-214)