• Title/Summary/Keyword: Zinc Chloride

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Effects of post anneal for the INZO films prepared by ultrasonic spray pyrolysis

  • Lan, Wen-How;Li, Yue-Lin;Chung, Yu-Chieh;Yu, Cheng-Chang;Chou, Yi-Chun;Wu, Yi-Da;Huang, Kai-Feng;Chen, Lung-Chien
    • Advances in nano research
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    • v.2 no.4
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    • pp.179-186
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    • 2014
  • Indium-nitrogen co-doped zinc oxide thin films (INZO) were prepared on glass substrates in the atmosphere by ultrasonic spray pyrolysis. The aqueous solution of zinc acetate, ammonium acetate and different indium sources: indium (III) chloride and indium (III) nitrate were used as the precursors. After film deposition, different anneal temperature treatment as 350, 450, $550^{\circ}C$ were applied. Electrical properties as concentration and mobility were characterized by Hall measurement. The surface morphology and crystalline quality were characterized by SEM and XRD. With the activation energy analysis for both films, the concentration variation of the films at different heat treatment temperature was realized. Donors correspond to zinc related states dominate the conduction mechanism for these INZO films after $550^{\circ}C$ high temperature heat treatment process.

Respondence Between Electrochemicl Fluctuations and Phenomenon for Localized Corrosion of Less-Noble Metals

  • Itoi, Yasuhiko;Take, Seisho;Tsuru, Tooru
    • Corrosion Science and Technology
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    • v.7 no.1
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    • pp.35-39
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    • 2008
  • We have been studying application of electrochemical noise (Fluctuation) analysis for localized corrosion. Foils of Zinc, Aluminum and Magnesium were used as specimens for electrochemical cell simulating localized corrosion. These specimens were dipped in sodium chloride solutions adjusted to each exponent of Hydrogen ion concentration (pH) condition of 5.5, 10, 12 respectively. Time variations of potential and current were measured in those solutions, and simultaneously the surfaces of specimens were observed using microscope with television monitor. Two types of electrochemical cells were arranged for experiments simulated localized corrosion. The fluctuations on trendy component of short-circuited potential and short-circuited current were appeared in synchronization. It was seemed that these fluctuations result from hydrogen evolution on the aluminum active site in the crevice from the microscopic observation. In the case of zinc and magnesium, fluctuations appeared on the trendy component of the corrosion potential. Two types fluctuation were detected. First one is the fluctuation varied periodically. The second one is the random fluctuation. It was seemed that these fluctuations result from generation of corrosion products and hydrogen evolution on the active site in the crevice of zinc and magnesium from the microscopic observation.

Corrosion Mechanism and Bond-Strength Study on Galvanized Steel in Concrete Environment

  • Kouril, M.;Pokorny, P.;Stoulil, J.
    • Corrosion Science and Technology
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    • v.16 no.2
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    • pp.69-75
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    • 2017
  • Zinc coating on carbon steels give the higher corrosion resistance in chloride containing environments and in carbonated concrete. However, hydrogen evolution accompanies the corrosion of zinc in the initial activity in fresh concrete, which can lead to the formation of a porous structure at the reinforcement -concrete interface, which can potentially reduce the bond-strength of the reinforcement with concrete. The present study examines the mechanism of the corrosion of hot-dip galvanized steel in detail, as in the model pore solutions and real concrete. Calcium ion plays an important role in the corrosion mechanism, as it prevents the formation of passive layers on zinc at an elevated alkalinity. The corrosion rate of galvanized steel decreases in accordance with the exposure time; however, the reason for this is not the zinc transition into passivity, but the consumption of the less corrosion-resistant phases of hot-dip galvanizing in the concrete environment. The results on the electrochemical tests have been confirmed by the bond-strength test for the reinforcement of concrete and by evaluating the porosity of the cement adjacent to the reinforcement.

Crystal Structure of the Metallo-Endoribonuclease YbeY from Staphylococcus aureus

  • Jinwook Lee;Inseong Jo;Ae-Ran Kwon;Nam-Chul Ha
    • Journal of Microbiology and Biotechnology
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    • v.33 no.1
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    • pp.28-34
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    • 2023
  • Endoribonuclease YbeY is specific to the single-stranded RNA of ribosomal RNAs and small RNAs. This enzyme is essential for the maturation and quality control of ribosomal RNA in a wide range of bacteria and for virulence in some pathogenic bacteria. In this study, we determined the crystal structure of YbeY from Staphylococcus aureus at a resolution of 1.9 Å in the presence of zinc chloride. The structure showed a zinc ion at the active site and two molecules of tricarboxylic acid citrate, which were also derived from the crystallization conditions. Our structure showed the zinc ionbound local environment at the molecular level for the first time. Molecular comparisons were performed between the carboxylic moieties of citrate and the phosphate moiety of the RNA backbone, and a model of YbeY in complex with a single strand of RNA was subsequently constructed. Our findings provide molecular insights into how the YbeY enzyme recognizes singlestranded RNA in bacteria.

Ecology of yeasts (효모의 생태학)

  • 조덕현
    • Korean Journal of Microbiology
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    • v.8 no.1
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    • pp.41-51
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    • 1970
  • In previous paper, it was reported that antibiotic substance such as tetracycline and streptomycin were produced by S'. albus subsp. and S'. globosus. And increase of mycelial growth of two strains, antibiotic production, and changes of pH range are extended to approximately 110-130 hrs in fermenting medium, there-after they decreased with culture period exception of pH range. Two Streptomyces spp. required commonly 4-5% starch as carbon sources and 1.5-2.0% soybean meal as nitrogen sources. However, 0.005-0.01M potassium phosphate dibasic, calcium carbonate (6mg/ml in S.albus subsp. and 2mg/ml in S. globosus), 0.01-0.03M, magnesium sulgate and 0.01M ferric chloride showed as optimal concentration for the growth of 2 strains. Mineral compoments such as zinc, manganese, cobalt, sodium and copper at the level of 10$^{-4}$ -10$^{-6}$ M were observed. Especially, zinc ion showed toxicity to the growth of 2 strains at 0.005M. In relation with pH, there is a little difference in mycelial growth with cultural initial pH.

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Studies on Zinc deficiency in paddy soil -I. Zinc deficiency of the rice plant in Korea and Philippine soils (답토양(畓土壤)에서의 아연결핍(亞鉛缺乏)에 관(關)한 연구(硏究) -I. 수도(水稻)에 있어서 아연결핍(亞鉛缺乏)에 관(關)한 한국(韓國)과 비율빈 답토양(畓土壤)에 대(對)한 비교연구)

  • Ahn, Jong Sung
    • Korean Journal of Soil Science and Fertilizer
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    • v.5 no.1
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    • pp.41-47
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    • 1972
  • An experiment was conducted to study the zinc deficiency of rice plant grown on Boeun soil of Korea and on Batangas soil of the philippines. The results obtained are summarized as follows: 1. Batangas soil was deficient in zinc because of the high pH, high organic matter and high calcium. Zinc content of the rice plant grown on Batangas soil was l6ppm. On the other hand, Boeun soil had low organic matter. Zinc content of the rice plant grown on Boeun soil was 33ppm. 2. The top leaf had higher zinc content than any other leaves. Zinc deficiency apparently occured when the zinc content of the rice plant was below 18ppm. 3. The physiologically acid fertilizer such as ammonium sulfate was more advantageous in improving zinc up take than the urea. 4. The zine deficiency was promoted when the Mn/Zn ratio is high, and zinc and manganess interact antagonistically in the growth of rice plant. 5. The zinc deficiency could be overcome by applying zinc chloride and fritted Trace elements to the Batangas soil, and the yield was significantly increased than conrtol.

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Purification and Characterization of a Fibrinolytic Enzyme from Snake Venom of Macrovipera lebetina turanica

  • Kwon, Ki-Rok;Park, Do-Il;Lee, Seung-Bae;Choi, Suk-Ho
    • Journal of Pharmacopuncture
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    • v.14 no.2
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    • pp.5-14
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    • 2011
  • Objectives: Fibrinolytic enzyme preparations were isolated from the snake venom of Macrovipera lebetica turanica in this study. Methods: The purity of the preparations was determined using SDS-PAGE and the enzymic characteristics of the purified fibrinolytic enzyme were determined. Results: 1. All of the two preparations with fibrinolytic activity obtained from the snake venom of M. l. turanicat contained the major polypeptide with the molecular weight of 27,500. One of the preparation showed purified fibrinolytic enzyme. 2. The purified fibrinolytic enzyme hydrolyzed ${\alpha}$-chain of fibrinogen faster than ${\beta}$-chain but not ${\gamma}$-chain. 3. The fibrinolytic activity was inhibited completely by EDTA, EGTA, 1,10-phenanthroline, and dithiothreitol. 4. The fibrinolytic activity was inhibited completely by calcium chloride, iron(III) chloride, mercuric chloride, and cobalt (II) chloride. 5. The fibrinolysis zone formed after addition of zinc sulfate was smaller but clearer than the control. Conclusions: These results suggested that the fibrinolytic enzyme purifed from the snake venom of M. l turanica was a metalloprotease containing dithiol group.

Effect of Dietary Cadmium Levels on Nutrient Digestibility and Retention of Iron, Copper and Zinc in Tissues of Growing Pigs

  • Han, X.Y.;Xu, Z.R.;Wang, Y.Z.;Tao , X.;Li, W.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.7
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    • pp.1007-1013
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    • 2004
  • This experiment was conducted to investigate the effect of cadmium levels on weight gain, nutrient digestibility and the retention of iron, copper and zinc in tissues of growing pigs. A total of one hundred and ninety-two crossbred pigs (barrows, Duroc$\times$Landrace$\times$Yorkshine, 27.67$\pm$1.33 kg of average initial body weight) were randomly allotted to four treatments. Each treatment had three replicates with 16 pigs per pen. The corn-soybean basal diets were supplemented with 0, 0.5, 5.0, 10.0 mg/kg cadmium respectively, and the feeding experiment lasted for eight-three days. Cadmium chloride was used as cadmium source. The results showed that pigs fed the diet containing 10.0 mg/kg cadmium had lower ADG and FCR than any other treatments (p<0.05). Apparent digestibility of protein in 10.0 mg/kg cadmium-treated group was lower than that of other groups (p<0.05). There was lower iron retention in some tissues of 5.0 mg/kg and 10.0 mg/kg cadmium treatments (p<0.05). However, pigs fed the diet 10.0 mg/kg cadmium had higher copper content in most tissues than that of any other groups (p<0.05). There was a significantly increase of zinc retention in kidney of 10.0 mg/kg cadmium additional group (p<0.05) and zinc concentrations in lymphaden, pancreas and heart of 10.0 mg/kg cadmium treatment were lower than those of the control (p<0.05). This study indicated that relatively high cadmium level (10.0 mg/kg) could decrease pig growth performance and change the retention of iron, copper and zinc in most tissues during extended cadmium exposure period.

Electrochemical Destruction of Cyanide Ions and Recovery of Zinc Ions from Electroplating Wastewater (도금폐수 중의 시안착이온의 전기화학적 분해 및 아연 회수에 관한 연구)

  • Niu, Lin;Ro, Byung-Ho;Jung, Cheul;Lee, Yong-Ill
    • Analytical Science and Technology
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    • v.13 no.6
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    • pp.699-704
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    • 2000
  • A study has been made for the electrochemical destruction of cyanide ions and removal of zinc ions from a simulated electroplating wastewater by the use of a platinum platized-titanium anode and a stainless steel cathode. Several experimental parameters, including electrolysis time, cell current, additives, and chloride concentration, have been investigated and used for efficient destruction of cyanide waste and removal of zinc ions from aqueous solutions. It was found that cell current and type of additives gave great effects on the destruction of cyanide ions and removal of zinc ions. The optimized conditions (electrolysis time: 1hr, current: 12A, additive: 0.5 M NaCl) have been defined to destroy cyanide ions and remove zinc ions with high efficiency and low operation cost. The proper reaction mechanism leading to the destruction of cyanide on the anode has also been discussed.

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Color Stability of Chlorophyll in Young Barley Leaf (새싹보리 클로로필의 색 안정화)

  • No, Junhee;Yoon, Huina;Park, Sara;Yoo, Seung Jin;Shin, Malshick
    • Journal of the East Asian Society of Dietary Life
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    • v.26 no.4
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    • pp.314-324
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    • 2016
  • To improve the color stability of chlorophyll in young barley leaf used as functional green biomaterial, the absorption spectrum, color values, and antioxidative activities of young barley leaf (YBL) treated with zinc ion solutions were investigated. The small pieces of fresh YBL in aqueous solution mixtures were autoclaved twice at $110^{\circ}C$ for 30 min (pH 5). Distilled water (BLA), 0.01% zinc chloride (BLAZ), 0.01% zinc citrate (BLAC), and 0.01% zinc lactate (BLAL) solutions were used. Treated YBL powders were extracted with 80% EtOH for 4 h. Chlorophyll a and b contents differed with different treatments. BLA decreased chlorophyll a and b contents, whereas others were maintained. Absorbance spectrums of chlorophyll at 400~700 nm showed different maximum peak wavelengths. After heating in acidic and neutral solutions (pH 3, 5, and 7), the colors of YBL and BLA changed from green to olive green, whereas BLAZ, BLAC, and BLAL remained green color. The antioxidative activities showed higher values in YBL extract than in treated extracts. From the above results, autoclaved YBL in zinc solution would increase the color stability and maintain green color regardless of acid and heat treatments.