• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.128-128
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• 2017

Copper (Cu) is very toxic to plant cells due to its inhibitory effects on many physiological and biochemical processes. In spite of its potential physiological and economic significance, molecular characterization after Cu stress has so far been grossly overlooked in sorghum. To explore the molecular alterations that occur in response to copper stress, the present study was executed in ten-day-old Cu-exposed leaves of sorghum seedlings. The growth of shoots was markedly reduced, and ionic alterations were prominently observed in the leaves when the seedlings were exposed to different concentrations (0, 100, and $150{\mu}M$) of $CuSO_4$. Using two-dimensional gels with silver staining, 643 differentially expressed protein spots (${\geq}1.5-fold$) were identified as either significantly increased or reduced in abundance. Of these spots, a total of 24 protein spots (${\geq}1.5-fold$) from Cu-exposed sorghum leaves were successfully analyzed by MALDI-TOF-TOF mass spectrometry. Of the 24 differentially expressed proteins from Cu-exposed sorghum leaves, a total of 13 proteins were up-regulated, and 11 proteins were down-regulated. The abundance of most identified protein species, which function in carbohydrate metabolism, stress defense, and protein translation, was significantly enhanced, while that of another protein species involved in energy metabolism, photosynthesis and growth and development were severely reduced. The resulting differences in protein expression patterns together with related morpho-physiological processes suggested that these results could help to elucidate plant adaptation to Cu stress and provide insights into the molecular mechanisms of Cu responses in $C_4$ plants. The over-expression of GAPDH plays a significant role in assisting Sorghum bicolor to attenuate the adverse effects of oxidative stress caused by Cu, and the proteins involved in resistance to stress helped the sorghum plants to tolerate high levels of Cu.

• The Plant Pathology Journal
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• v.29 no.4
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• pp.374-385
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• 2013

Environmental stresses induce several plant pathogenic bacteria into a viable but nonculturable (VBNC) state, but the basis for VBNC is largely uncharacterized. We investigated the physiology and morphology of the copper-induced VBNC state in the plant pathogen Ralstonia solanacearum in liquid microcosm. Supplementation of $200{\mu}M$ copper sulfate to the liquid microcosm completely suppressed bacterial colony formation on culture media; however, LIVE/DEAD BacLight bacterial viability staining showed that the bacterial cells maintained viability, and that the viable cells contain higher level of DNA. Based on electron microscopic observations, the bacterial cells in the VBNC state were unchanged in size, but heavily aggregated and surrounded by an unknown extracellular material. Cellular ribosome contents, however, were less, resulting in a reduction of the total RNA in VBNC cells. Proteome comparison and reverse transcription PCR analysis showed that the Dps protein production was up-regulated at the transcriptional level and that 2 catalases/peroxidases were present at lower level in VBNC cells. Cell aggregation and elevated levels of Dps protein are typical oxidative stress responses. $H_2O_2$ levels also increased in VBNC cells, which could result if catalase/peroxidase levels are reduced. Some of phenotypic changes in VBNC cells of R. solanacearum could be an oxidative stress response due to $H_2O_2$ accumulation. This report is the first of the distinct phenotypic changes in cells of R. solanacearum in the VBNC state.

• Journal of Environmental Science International
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• v.25 no.1
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• pp.173-179
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• 2016

Leaf water and osmotic potential, chlorophyll content, photosynthetic rate, and electrolyte leakage were measured to evaluate tolerance to water stress in wild-type (WT) and transgenic tobacco plants (TR) expressing copper/zink superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts. Leaf water potential of both WT and TR plants decreased similarly under water stress condition. However, leaf osmotic potential of TR plants more negatively decreased in the process of dehydration, compared with WT plants, suggesting osmotic adjustment. Stomatal conductance (Gs) in WT plants markedly decreased from the Day 4 after withholding water, while that in TR plants retained relatively high values. Relatively low chlorophyll content and photosynthetic rate under water stress were shown in WT plants since $4^{th}$ day after treatment. In particular, damage indicated by electrolyte leakage during water stress was higher in WT plants than in TR plants. On the other hand, SOD and APX activity was remarkably higher in TR plants. These results indicate that transgenic tobacco plants expressing copper/zink superoxide dismutase (CuZnSOD) and ascorbate peroxidase (APX) in chloroplasts improve tolerance to water stress.

• Journal of the Microelectronics and Packaging Society
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• v.13 no.2 s.39
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• pp.9-13
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• 2006

The copper lines in COF are usually fabricated by subtractive method. As the width of lines are smaller, the subtractive method has a lateral etching problems. In semi-additive method, copper lines are fabricated by lithographic technique followed by electroplating method. Fine line patterns of $10-40{\mu}m$ were used for this study. Two different types of thick photoresist, AZ4620 and PMER900, were employed for PR mold. Copper lines were fabricated by electroplating method. The crack were found in fine copper lines due to high residual stress when normal copper electroplating bath were used. The via filling copper electroplating bath were replaced the normal electroplating bath and then cracks were not found in the fine copper lines. During substrate etching, the lateral etching of copper lines were not occurred.

• Transactions of Materials Processing
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• v.4 no.2
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• pp.123-130
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• 1995

The present study is concerned with the hydrostatic extrusion process for the copper-clad aluminum rod through metallurgical joining. The rigid viscoplastic finite element analyses are performed for the steady state extrusion process of the bimetal rod. An algorithm for finding the interface profile of the bimetal rod by tracking a particle path in Eulerian domain is presented. The distributions of the effective strain rate, equivalent stress and hardness are examined for the several extrusion ratios. Experiments are also carried out for the copper-clad aluminum rod at room temperature. It is found out that the finite element predictions are generally in good agreement with the experimental observations. The detail comparisons of the extrusion loads predicted by the element method with those by experiments are given.

• Journal of the Korean Society of Marine Environment & Safety
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• v.5 no.2
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• pp.27-33
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• 1999

The present study is concerned with the hydrostatic extrusion process of copper-clad aluminum rod through metallurgical joining. In this study, the rigid plastic finite element program, HICKORY, is used to analyze the steady state extrusion process of the bimetal rod. Simulations are performed for copper-clad aluminum rod with several extrusion ratio to give the distributions of effective strain rate, equivalent stress and hardness. Experiments are also carried out for aluminum-inserted copper rod at room temperature. It is found out that finite element predictions are generally in good agreement with the experimental observations. The detail comparison of the extrusion loads by the finite element method with those by experiments are given.

• Advances in Traditional Medicine
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• v.4 no.3
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• pp.211-214
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• 2004

The inhibitory effect of dl-puerol A as but-2-enolide isolated from Sophora japonica was investigated on copper ion-induced protein oxidative modification in vitro. It inhibited copper-induced protein oxidative modification. However, its inhibitory effect was a little weaker than that of $dl-{\alpha}-tocopherol$ as an antioxidant. The results demonstrated that dl-puerol A, one of but-2-enolides, might be of use in the oxidative stress.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1059-1062
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• 2003

Micro-tensile testing system has been developed and micro-tensile tests for copper foil have been carried out. The system consisted of a micro tensile loading system and a micro-ESPI system for measuring strain. The loading system has a maximum loading capacity of 50N and a stroke resolution of 4.5nm. Stress-strain curves for the electro-deposited copper foil with the thickness of 18$\mu\textrm{m}$ were obtained, and tensile properties, including elastic modulus, yielding strength and tensile strength, were determined. The tensile properties obtained under three different conditions of testing speed showed a dependency on the speed.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.40 no.10
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• pp.1-8
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• 2003

Copper thin films were deposited on a Cu/Ta/Si substrate using the electroplating technique. Deposition rate was about 200 nm/min in proportion to current density and in inverse proportion to flow rate. Resistivity of copper thin film was approximately 2.1 ${\mu}$Ωcm and Int$\sub$(111)//Int$\sub$(200)/ ratio of copper film was 5.4 and no significant impurities were detected. After the deposition, electroplating copper films were annealed at various temperatures in a background pressure of 10$\^$-3/ torr. The resistivity of copper thin films were improved by ∼17 % and texture was improved by ∼40 % after annealing at 170$^{\circ}C$. The stress in films was not reduced much after annealing below 170$^{\circ}C$.

• Journal of the Korean Ceramic Society
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• v.43 no.9 s.292
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• pp.544-551
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• 2006

The sealing technique between a glass tube and a copper heat pipe in an evacuated tube solar collector is studied. In this study two different sealing techniques, such as flame method and furnace firing, are examined. After the sealing of a copper to a glass, the oxidation state of the copper and its bonding morphology were examined by SEM and XRD. Its oxidation was retarded by coating of borate solution on the copper, and $Cu_2O(cuprite)$ turned into CuO(tenorite) with increase in a firing temperature and firing time. Porous structure was found in the oxide layer when CuO formed. The best sealing morphology was observed when the thickness of the oxidation layer was less than $20{\mu}m$. The sealing technique performed in a furnace was promising and the satisfactory result was obtained when the sample was fired at $950^{\circ}C$ for 5 min under $N_2$ atmosphere. Annealing procedure is recommended to remove the stress left at the bonding zone.