• Title/Summary/Keyword: Effect of Cu addition

Search Result 506, Processing Time 0.032 seconds

The flux pinning properties of BaSnO3-added GdBa2Cu3O7-δ films with varying growth conditions

  • Lee, J.K.;Oh, J.Y.;Lee, J.M.;Kang, W.N.;Kang, B.
    • Progress in Superconductivity and Cryogenics
    • /
    • v.19 no.3
    • /
    • pp.18-22
    • /
    • 2017
  • Addition of $BaSnO_3$ (BSO) to $GdBa_2Cu_3O_{7-{\delta}}$ (GdBCO) is reported to enhance the flux pinning property of GdBCO thick films. To investigate the effect of growth condition on the pinning properties, 700 nm-thick BSO-added GdBCO films deposited with varying temperatures and growth rates were prepared by using a pulsed laser deposition method. As the deposition temperature increases, the critical current density and the pinning force density show an improved field dependence up to $750^{\circ}C$ due to the increase in the formation of the a-axis growth and the BSO nanostructures. The films deposited at higher temperatures show degraded surfaces and as a result, degraded pinning behaviors. For the change in growth rate, the critical current density and the pinning force increase as the repetition rate increase at low magnetic fields, but this behavior is reversed in high magnetic fields. These results indicate that the film growth conditions significantly affect the formation of BSO nanostructures and the pinning properties of BSO-added GdBCO films.

A Study on the Ball-off of Via Balls Bonded by Solder Paste (Solder Paste로 접합된 비아볼의 Ball-off에 관한 연구)

  • Kim, Kyoung-Su;Kim, Jin-Young
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.17 no.6
    • /
    • pp.575-579
    • /
    • 2004
  • Package reliability test was conducted to investigate the effect of solder paste composition at BGA Package. It was found that the shape and size of the phase form are affected by the processing parameters. The material have used to fill in the via was Sn/36Pb/2Ag and Sn/0.75Cu type solder paste. Sn/36Pb/2Ag and Sn/0.75Cu paste were fabricated on Tape-BGA substrates by screen printing process, and via ball mount data were characterized with variations of dwell time of 85 seconds at reflow peak temperature at 22$0^{\circ}C$ or 24$0^{\circ}C$. The test condition was MRT 30 $^{\circ}C$/60 %RH/96 HR. Failures formed of a ball-off in solder paste process were observed by using a Optical Microscope and SEM(Scanning Electron Microscope). It was concluded that intermetallic layer growth played important roles in increasing solder fatigue strength for addition of Ag composition. The degradation of shear strength of solder composition is discussed.

The effect of L-Ascorbic Acid on the Oxidative Reaction of Lysine in Collagen. (Collagen 분자 중의 lysine 산화반응에 미치는 비타민 C의 영향)

  • 김미향
    • Journal of Life Science
    • /
    • v.14 no.3
    • /
    • pp.478-483
    • /
    • 2004
  • In a model reaction using lysyl oxidase purified partilally from bovine aorta, effect of L-ascorbic acid AsA on the oxidative reaction of lysine in collagen was investigated. Addition of Ash to the reaction mixture under aerobic conditions resulted in the decrease of enzymatic activity. In order to examine the specificity of AsA in the oxidative reaction of lysine, other reductants including A derivatives instead of AsA were added to the reaction mixture. Thiol such as glutathione had no effect on the activities of lysyl oxidase. on the other hand, it was observed that erythorbic acid, which was a stereoisomer of AsA, had the same inhibitory effect on this oxidative reaction as AsA. Moreover, by the addition of 3,4-dihydroxybenzoate, which was structural analog of AsA, the activities decreased in a similar manner to that of AsA. These results indicate that the regulatory effect of AsA on lysyl oxidase is attributed to characteristics of the structure. From the determination of Ash remained in the reaction mixture, it is shown that AsA concentration remarkably decreased by lysyl oxidase of the reaction mixture. It is hypothesized that endiol groups reduces the enzyme-bound $Cu^{+2}$ required for further progress of the reaction, and suggests that AsA regulates specifically the reduction of $Cu^{+2}$ required to oxidize lysyl oxidase. This findings support that AsA has an important regulatory role on the oxidative reaction of lysine and on changes of collagen cross-links with aging.

Effect of Heavy Metals on Mycelial Growth of Color Mutants at Pleurotus ostreatus (중금속이 느타리버섯 자실체 색변이체의 균사생장에 미치는 영향)

  • Lee, Kang-Hyo;Seok, Soon-Ja;Weon, Hang-Yeon;Kim, Seung-Hwan;Kim, Wan-Gyu;Sung, Jae-Mo
    • The Korean Journal of Mycology
    • /
    • v.36 no.2
    • /
    • pp.172-177
    • /
    • 2008
  • Mycelial growth of Pleurotus ostreatus isolates was examined on PDA media added with heavy metals to reveal effects of heavy metals on mycelial growth of the fungus. Cd and Cu strongly inhibited mycelial growth of three isolates of fungus tested. However, addition of $2{\sim}10\;mM$ Pb to growing media of white color mutant of fungus resulted in increase of the fungal growth rate. Addition of 2 mM Cr to the media resulted in increase of growth rate of the white color mutant and the dark color mutant of fungus. Mycelial growth rate of the white color mutant was relatively better than the other isolates on media added with Cr, Pb, Cu, or Mn, respectly. Tolerance of the white color mutans to heavy metals was higher than that of the black color mutant. It is suggested that tolerance of the white color mutant to heavy metals was not controled by color-related substance of the fungus.

Studies on Heat Sensitivity of Egg Albumen II. Effects of pH and/or the Addition of Metal ions on Heat Sensitivity of Egg Albumen (난백의 숙감수성에 관한 연구 II. 금속염의 첨가와 pH가 난백의 열감수성에 미치는 영향)

  • 유익종;이성기;김영붕
    • Korean Journal of Poultry Science
    • /
    • v.16 no.1
    • /
    • pp.17-22
    • /
    • 1989
  • In order to dull heat sensitivity of egg albumen, metal ions (aluminium, ferric, ferrous, copper) were added and functional properties or egg albumen were determined before and after heat treatment at $60^{\circ}C$ for 5 minutes. Effect of pH on heat sensitivity of aluminium salt added egg albumen was also determined. Addition of metal ions increased turbidity of egg albumen before and after the heat treatment. Changes of the turbidity were minimized by addition of aluminium salt. The foaming power was markedly increased by addition of ferric salt before the heat treatment and increased by addition of aluminium, ferric and copper salt after the heat treatment. Before the heat treatment the foam was stable by addition of ferric and ferrous salt but after the heat treatment it was stable by addition of aluminium and ferric salt. The turbidity and foaming property of the egg albumen with aluminium salt were not largely changed after the heat treatment at pH range 7 to 8.5. Over pH 9 the turbidity and foaming power were not decreased, but the foam stability was increased before and after the heat treatment. Salmonella typhimurium ATCC 14028 (10$^{6}$ cells/$m\ell$) inoculated in egg albumen at pH range 7 to 8.5 was destructed by the heat treatment.

  • PDF

Effect of Additives on the Conidial Viability of Aspergillus sp. PS-104 (Aspergillus sp. PS-104의 분생포자 생활력에 미치는 첨가제 효과)

  • Kang, Sun-Chul;Kim, Eun-Lyang
    • Korean Journal of Environmental Agriculture
    • /
    • v.26 no.1
    • /
    • pp.77-84
    • /
    • 2007
  • A fungus, Aspergillus sp. PS-104, with the high phosphate-solubilizing activities was isolated from Korean upland soil and formulated into a solid powder type with various additives. For the long-time preservation of conidia, some additives (Tween 80, SDS, Triton X-100, glucose, glycerol, corn oil, bio-ceramic, PEG 200, $Cu^{++}$, $Mo^{+++}$, $Fe^{++}$, $Ca^{++}$ and $Zn^{++}$) were supplemented in the rice-cooked hard medium with various concentrations (0, 0.001, 0.01, 0.1, 1.0 and 5.0%). In case of surfactants. the highest relative viability of the Aspergillus sp. PS-104 conidia was recorded nearly to 80% by the addition of 0.01 to 0.1% Tween 80, while 50% in control. The number of conidia were found to be about 100 times higher when treated at 0.01 to 0.1% Tween 80 as compared to control. Relative viability of the conidia was decreased in order of Tween 80 $\geq$ SDS > Triton X-100 during the storage at $25^{\circ}C$. As regards the organic additives, the relative viability of Aspergillus sp. PS-104 conidia was also recorded nearly to 80% by the addition of 1.0% bio-ceramic, and 5.0% glucose and sucrose during the storage at $25^{\circ}C$. In case of metal ions, the relative viability of Aspergillus sp. PS-104 conidia was decreased in order of $Cu^{2+}>Ca^{2+}>Mo^{3+}>Zn^{2+}>Fe^{2+}$ during the storage at $25^{\circ}C$.

The Effects of Different Copper (Inorganic and Organic) and Energy (Tallow and Glycerol) Sources on Growth Performance, Nutrient Digestibility, and Fecal Excretion Profiles in Growing Pigs

  • Huang, Y.;Yoo, J.S.;Kim, H.J.;Wang, Y.;Chen, Y.J.;Cho, J.H.;Kim, I.H.
    • Asian-Australasian Journal of Animal Sciences
    • /
    • v.23 no.5
    • /
    • pp.573-579
    • /
    • 2010
  • This study was conducted to determine the effects of different copper (inorganic and organic) and energy (tallow and glycerol) sources on growth performance, nutrient digestibility, gas emission, diarrhea incidence, and fecal copper concentration in growing pigs by using a 2${\times}$2 factorial design. In this trial, 96 pigs (63 d of age) were employed, with an average initial weight of 28.36${\pm}$1.14 kg. The dietary treatments were i) basal diet with 134 ppm copper (Korea recommendation) as $CuSO_4$+tallow; ii) basal diet with 134 ppm Cu as $CuSO_4$+glycerol; iii) basal diet with 134 ppm copper as CuMet+tallow; and iv) basal diet with 134 ppm copper as CuMet+ glycerol. Throughout the entire experimental period, no differences were noted among treatment groups with regard to the magnitude of improvement in ADG (average daily gain), ADFI (average daily feed intake) and G/F (gain:feed) ratios. The nitrogen (N) digestibility of pigs fed on diets containing organic copper was improved as compared with that observed in pigs fed on diets containing inorganic copper (p<0.05). An interaction of copper${\times}$energy was observed in the context of both nitrogen (p<0.05) and energy (p<0.01) digestibility. Ammonia emissions were significantly lower in the organic copper-added treatment groups than in the inorganic copperadded treatment groups (p<0.05). Mercaptan and hydrogen sulfide emissions were reduced via the addition of glycerol (p<0.05). No significant effects of copper or energy source, or their interaction, were observed in reference to diarrhea appearance and incidence throughout the entirety of the experimental period. The copper concentration in the feces was significantly lower in the organic copper source treatment group than was observed in the inorganic copper source treatment group (p<0.05). The results of this experiment show that organic copper substituted for inorganic copper in the diet results in a decreased fecal copper excretion, but exerts no effect on performance. The different energy (tallow and glycerol) sources interact with different copper sources and thus influence nutrient digestibility. Glycerol supplementation may reduce the concentrations of odorous sulfuric compounds with different Cu sources.

Numerical Analysis of Thermo-mechanical Stress and Cu Protrusion of Through-Silicon Via Structure (수치해석에 의한 TSV 구조의 열응력 및 구리 Protrusion 연구)

  • Jung, Hoon Sun;Lee, Mi Kyoung;Choa, Sung-Hoon
    • Journal of the Microelectronics and Packaging Society
    • /
    • v.20 no.2
    • /
    • pp.65-74
    • /
    • 2013
  • The through-silicon via (TSV) technology is essential for 3-dimensional integrated packaging. TSV technology, however, is still facing several reliability issues including interfacial delamination, crack generation and Cu protrusion. These reliability issues are attributed to themo-mechanical stress mainly caused by a large CTE mismatch between Cu via and surrounding Si. In this study, the thermo-mechanical reliability of copper TSV technology is investigated using numerical analysis. Finite element analysis (FEA) was conducted to analyze three dimensional distribution of the thermal stress and strain near the TSV and the silicon wafer. Several parametric studies were conducted, including the effect of via diameter, via-to-via spacing, and via density on TSV stress. In addition, effects of annealing temperature and via size on Cu protrusion were analyzed. To improve the reliability of the Cu TSV, small diameter via and less via density with proper via-to-via spacing were desirable. To reduce Cu protrusion, smaller via and lower fabrication temperature were recommended. These simulation results will help to understand the thermo-mechanical reliability issues, and provide the design guideline of TSV structure.

Effect of Phosphorus Addition on Microstructure and Mechanical Properties of Sintered Low Alloy Steel (저합금강 소결체의 미세조직 및 기계적 특성에 미치는 인(P) 첨가의 영향)

  • Kim, Yoo-Young;Cho, Kwon-Koo
    • Journal of Powder Materials
    • /
    • v.27 no.1
    • /
    • pp.31-36
    • /
    • 2020
  • Phosphorus is an element that plays many important roles in powder metallurgy as an alloy element. The purpose of this study is to investigate the influence of phosphorus addition on the microstructures and mechanical properties of sintered low-alloy steel. The sintered low-alloy steels Fe-0.6%C-3.89%Ni-1.95%Cu-1.40%Mo-xP (x=0, 0.05, 0.10, 0.15, 0.20%) were manufactured by compacting at 700 MPa, sintering in H2-N2 at 1260 ℃, rapid cooling, and low-temperature tempering in Ar at 160 ℃. The microstructure, pore, density, hardness, and transverse rupture strength (TRS) of the sintered low-alloy steels were evaluated. The hardness increased as the phosphorus content increased, whereas the density and TRS showed maximum values when the content of P was 0.05%. Based on microstructure observation, the phase of the microstructure changed from bainite to martensite as the content of phosphorus is increased. Hence, the most appropriate addition of phosphorus in this study was 0.05%.

Crystallographic and Magnetic Properties of Cu0.1Fe0.9Cr2S4 (Cu0.1Fe0.9Cr2S4의 결정학적 및 자기적 성질에 관한 연구)

  • Son, Bae-Soon;Kim, Sam-Jin;Kim, Chul-Sung
    • Journal of the Korean Magnetics Society
    • /
    • v.14 no.1
    • /
    • pp.33-37
    • /
    • 2004
  • Cu$_{0.1}$Fe$_{0.9}$Cr$_2$S$_4$ has been studied with Mossbauer spectroscopy, x-ray diffraction, vibrating sample magnetometer (VSM), and magnetoresistance (MR) measurement. The crystal structure was determined to be a cubic spinel with lattice parameter a$_{0}$=9.9880 $\AA$. The MR measurements show a semiconductor behavior below 110 K and metal behaved above 100 K. The temperature dependence of magnetization of Cu$_{0.1}$Fe$_{0.9}$Cr$_2$S$_4$ was reported. In addition to a large irreversibility between the zero-field-cooling (ZFC) and the field-cooling (FC) magnetization at applied field H=100 Oe, a cusp-like anomaly was observed in both the FC and ZFC curves. It shifted toward the lower temperature region with increasing magnetic field, and then showed convex type maximum at 110 K, under the applied field of 5 kOe. The Mossbauer spectra were measured from 15 K to room temperature. The asymmetric line broadening was observed for the sample Cu$_{0.1}$Fe$_{0.9}$Cr$_2$S$_4$, and it was considered to be dynamic Jahn-Teller relaxation. The charge state of Fe ions was ferrous in character. The unusual reduction of magnetic hyperfine field below 110 K was interpreted in terms of cancellation effect between the mutually opposite orbital current field (H$_{L}$) and Fermi contact field (H$_{C}$).