• Title/Summary/Keyword: Silver reduction

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Effects of Scalp Management using SUKI on Heavy Metal Discharge (SUKI(silver tools)를 활용한 두피 관리가 중금속 배출에 미치는 영향)

  • Lee, Jun-Suk;Hong, Seong-Gyun
    • Journal of Convergence for Information Technology
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    • v.10 no.12
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    • pp.208-215
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    • 2020
  • The purpose of this study was to access the effects of detoxification of hair by SUKI(silver tools). The subjects of this study participated 26 persons(EG 13 and CG 13), Experimental group was performed SUKI programs combined with scalp and hair for two times per week, during 8 weeks. The results was of comparison of variations in each groups showed that there was a significant difference(6items) in the experimental group(p<.05). But 2items(Pb, Cs) was not showed it. Among the hazardous heavy metals in research, Al, Ba and Hg showed the greatest reduction rate of difference. Thus, the using of the SUKI tool has been shown to affect some heavy metal emissions (p<.05). In conclusion, it is thought that it can be used as basic data for heavy metal discharge of scalp through continuous research in the future.

Effect of the Processes of Polysilazane Solid Electrolyte Layer and Silver Active Electrode on the Electrical Characteristics of Memristor (폴리실라잔 고체 전해질 층과 은 활성 전극의 공정이 멤리스터의 전기적 특성에 미치는 영향)

  • Hui-Su Yang;Gyeong-seok Oh;Dong-Soo Kim;Jin-Hyuk Kwon;Min-Hoi Kim
    • Journal of IKEEE
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    • v.27 no.1
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    • pp.25-29
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    • 2023
  • Effect of the processes of polysilazane solid electrolyte layer and silver (Ag) active electrode on the electrical characteristics of memristor was investigated. The memristor with the solid electrolyte annealed at higher temperature exhibited the higher set voltage and better memory retention characteristics than that annealed at lower temperature. The increase in the set voltage and the improvement of the memory retention characteristic at high annealing temperature were attributed to a reduction in the void density and an increase in the void uniformity inside the solid electrolyte, respectively. In the case where the polysilazane solution's concentration is high, the memristor exhibited rapid degradation of low resistive state even annealed at high temperature. Lastly, it was shown that the memristor with the solution-processed Ag active electrode showed WORM property unlike that with the vacuum-processed Ag active electrode. The WORM property was possibly due to morphological defects present in the solution-processed Ag active electrode.

Antifungal Activity of Silver Salts of Keggin-Type Heteropolyacids Against Sporothrix spp.

  • Mathias, Luciana Da Silva;Almeida, Joao Carlos De Aquino;Passoni, Luis Cesar;Gossani, Cristiani Miranda David;Taveira, Gabriel Bonan;Gomes, Valdirene Moreira;Vieira-Da-Motta, Olney
    • Journal of Microbiology and Biotechnology
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    • v.30 no.4
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    • pp.540-551
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    • 2020
  • Sporotrichosis is a chronic and subacute mycosis causing epidemiological outbreaks involving sick cats and humans in southeastern Brazil. The systemic disease prevails in cats and in humans, with the symptoms restricted to the skin of immunocompetent individuals. Under these conditions, the prolonged treatment of animals and cases of recurrence justify the discovery of new treatments for sporotrichosis. This work addresses the antifungal activity of silver salts of Keggin-type heteropolyacid salts (Ag-HPA salts) such as Ag3[PW12O40], Ag6[SiW10V2O40], Ag4[SiW12O40] and Ag3[PMo12O40] and interactions with the antifungal drugs itraconazole (ITC), terbinafine (TBF) and amphotericin B (AMB) on the yeast and mycelia forms of Sporothrix spp. Sporothrix spp. yeast cells were susceptible to Ag-HPA salts at minimum inhibitory concentration (MIC) values ranging from 8 to 128 ㎍/ml. Interactions between Ag3[PW12O40] and Ag3[PMo12O40] with itraconazole and amphotericin B resulted in higher antifungal activity with a reduction in growth and melanization. Treated cells showed changes in cell membrane integrity, vacuolization, cytoplasm disorder, and membrane detachment. Promising antifungal activity for treating sporotrichosis was observed for the Ag-HPA salts Ag3[PMo12O40] and Ag3[PW12O40], which have a low cost, high yield and activity at low concentrations. However, further evaluation of in vivo tests is still required.

Removal of Bromate by Iron, Copper and Silver Impregnated Activated Carbon (철, 구리, 은 첨착활성탄을 이용한 브롬산염의 제거)

  • Choi, Seong-Woo;Park, Seung-Cho
    • Journal of Korean Society of Environmental Engineers
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    • v.28 no.2
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    • pp.178-182
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    • 2006
  • The purpose of this research is to remove the bromate that is a disinfection by-poduct of water purification by ozone. I achieved a high rate of removal with iron, copper, or silver impregnated activated carbon by using both the adsorbing power of granular activated carbon and the oxidizing power of metal ions as deoxidizing agents. In the removal test of bromate with the quantity of activated carbon input I injected each activated carbon by 0.1, 0.3, 0.1, and 1.0 g and let them react for 240 minutes. I found the quantity of removed bromate was in proportion to the amount of input. The removal rate of bromate increased about 20% when I used acid treated activated carbon. The metal impregnated activated carbon had a higher removal rate of bromate than that of general activated carbon by about $30{\sim}50%$. Iron impregnated activated carbon showed a 92% removal rate of bromate. Iron, copper, or silver impregnated activated carbon removed about $0.9{\sim}1.5mg\;{BrO_3}^-/g$ while general activated carbon removed about $0.02{\sim}0.45mg\;{BrO_3}^-/g$. In the continuous column reaction, there were breakthrough phenomena at 96, 180, and 252 hours when I tested EBCT by 1, 2 and 3 minutes while I was changing the flux rate of bromate from 15.6 to 46.8 mL/min.

Fabrication of a Ultrathin Ag Film on a Thin Cu Film by Low-Temperature Immersion Plating in an Grycol-Based Solution (글리콜 용매 기반 저온 치환 은도금법으로 형성시킨 동박막 상 극박 두께 Ag 도금층)

  • Kim, Ji Hwan;Cho, Young Hak;Lee, Jong-Hyun
    • Journal of the Microelectronics and Packaging Society
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    • v.21 no.2
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    • pp.79-84
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    • 2014
  • To investigate the plating properties of a diethylene glycol-based Ag immersion plating solution containing citric acid, silver immersion plating was performed in a range from room temperature to $50^{\circ}C$ using sputtered Cu specimens. The used Cu specimens possessed surface structure with large numbers of pinholes which were created with over-acid etching. The Ag immersion plating performed at $40^{\circ}C$ exhibited that the pinholes and copper surface were completely filled with Ag just after 5 min mainly due to galvanic displacement reaction, indicating the best plating properties. Subsequently, the surface morphology of Ag-coated Cu became rougher as the plating time increased to 30 min because of the deposition of silver nanoparticles created by chemical reduction in the solution. The specimen that its overall surface was covered with silver indicated the start of oxidation at temperature higher than around $50^{\circ}C$ in air as compared with pure Cu, indicating enhanced anti-oxidation properties.

Performance Evaluation of Magnesium Bipolar Plate in Lightweight PEM Fuel Cell Stack for UAV (무인기용 경량 PEM 연료전지 스택용 마그네슘 분리판의 성능평가)

  • Park, To-Soon;Oh, Ji-Hyun;Ryu, Tae-Kyu;Kwon, Se-Jin
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.10
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    • pp.788-795
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    • 2013
  • A magnesium bipolar plate whose surface was protected by thinly deposited silver layer was investigated as an alternative to existing graphite bipolar plate of PEM fuel cells. Thin silver layer of $3{\mu}m$ was deposited on a magnesium alloy substrate by physical vapor deposition (PVD) method in an environment of $180^{\circ}C$. A number of tests were conducted on the fabricated magnesium based bipolar plates to determine their suitability for use in PEM fuel cell stacks. The test on corrosion resistance in the same pH condition as in a PEM operation demonstrated the layer protected the magnesium alloy substrate, while unprotected substrate suffered from severe corrosion. The contact resistance of the fabricated bipolar plate was less than $20m{\Omega}-cm^2$ which was superior to the conventional bipolar plates. A single cell was constructed using the fabricated bipolar plates and power output was measured. Due to the enhanced conductivity caused by low contact resistance, slight increase was observed in current density and output voltage. With low density of the magnesium substrate and ease on machining, the weight reduction of the stack of 30~40 % is possible to produce the same power output.

Effect of Uniconazole and Silver Thiosulfate Treatment on Reduction of Ozone Injury in Snap Bean Plants (Uniconazole과 Silver Thiosulfate 처리(處理)가 강남콩의 오존피해(被害) 경감(輕減)에 미치는 효과(效果))

  • Ku, Ja Hyeong;Won, Dong Chan;Cho, Jeong Hee;Shin, Dae Shik
    • Korean Journal of Agricultural Science
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    • v.19 no.2
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    • pp.161-169
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    • 1992
  • Studies were conducted to examine the effects of single or combined treatment of uniconazole [(E)-1-(4-chlorophenyl)-4, 4-dimethyl 2(1, 2,-4-triazol-1-yl)-1-penten-3-ol)] and silver thiosulfate (STS) on reducing ozone injury to snap beans (Phaseolus vulgaris L. 'Strike'). Two weeks after seeding, plants were given a soil drench of uniconazole(XE-1019) solution at concentrations of 0.001, 0.005 and 0.025 mg/pot, and then two days prior to ozone fumigation, 0.3 and 0.6 mM STS containing 0.01% Tween-20 were also sprayed. Uniconazole was effective in providing protection against ozone injury through increase activities of free radical scavengers such as superoxide dismutase (SOD) and peroxidase (POD) as well as the increase of chlorophyll content and stomatal resistance resulted from plant growth retardation. The phytoprotective effects of STS seemed to be related to its properly of blocking the ethylene action and increasing activities of SOD and POD. Even at low concentrations, a combined treatment with uniconazole drench, STS spray significantly reduced ozone injury compared to single application.

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Two Crystal Structures of Dehydrated Ag$^+$ and K$^+$Exchanged Zeolite A, $Ag_{12-x}K_x$-A, x = 1.3 and 2.7

  • Kim, Yang;Song, Seong-Hwan;Park, Jong-Yul;Kim, Un-Sik
    • Bulletin of the Korean Chemical Society
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    • v.9 no.6
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    • pp.338-341
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    • 1988
  • Two crystal structures of fully dehydrated silver and potassium exchanged zeolite A, stoichiometries of $Ag_{9.3}K_{{2.7}^-}A$ (${\alpha}$ = 12.282(2) ${\AA}$) and $Ag_{10.7}K_{{1.3}^-}{\AA}$ (${\alpha}$ = 12.287(2) A) per unit cell, have been determined from 3-dimensional x-ray diffraction data gathered by counter methods. All structures were solved and refined in the cubic space group Pm3m at 21(1)$^{\circ}C$ . The crystals of $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$ were prepared by flow method using exchange solutions in which mole ratios of $AgNO_3$ and $KNO_3$ were 1:10 and 1:5, respectively, with total concentration of 0.05M. The structures of the dehydrated $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$ were refined to yield the final error indices $R_1$ = 0.037 and $R_2$ = 0.040 with 321 reflections, and $R_1$ = 0.042 and $R_2$ = 0.043 with 371 reflections, repectively, for which I > 3${\sigma}$(I). In both structures, eight $Ag^+$ ions are found nearly at 6-ring centers and each $Ag^+$ ion is nearly in the (1 1 1) plane at its O(3) ligands. The 8-ring sites are preferentially occupied by $K^+$ ions in both structures. 1.3 and 1.7 reduced silver atoms per unit cell were found inside of sodalite units of $Ag_{9.3}K_{{2.7}^-}A$ and that of $Ag_{10.7}K_{{1.3}^-}A$, respectively. These reduced silver species were presumably formed from the reduction of $Ag^+$ ions by oxide ions of residual water molecule or of the zeolite framework. These two crystals may be presented as hexasilver cluster in 21.7% and 28.3% of sodalite unit cells for $Ag_{9.3}K_{{2.7}^-}A$ and $Ag_{10.7}K_{{1.3}^-}A$, repectively.

Effect of a Combined Treatment with Uniconazole, Silver Thiosulfate on Reduction of Ozone Injury in Tomato Plant (Uniconazole 과 Silver Thiosulfate 의 복합처리가 토마토의 오존피해경감에 미치는 효과)

  • Ku, Ja-Hyeong;Won, Dong-Chan;Kim, Tae-Il;Krizek, Donld T.;Mirecki, Roman M.
    • Korean Journal of Environmental Agriculture
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    • v.11 no.1
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    • pp.50-58
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    • 1992
  • Studies were conducted to determine the combined effect of uniconazole [(E) -1-(4-chlorophenyl)-4, 4-demethyl 2-(1,2,4 triazol-1-yl)-1-penten-3-ol] and silver thiosulfate $[Ag {(S_2O_3)}^3\;_2-]$ (STS) on reduction of ozone injury in tomato plants(Lycopersicon esculentum Mill. 'Pink Glory'). Plants were given a 50ml soil drench of uniconazole at concentrations of 0, 0.001, 0.01 and 0.1 mg/pot at the stage of emerging 4th leaf. Two days prior to ozone fumigation, STS solution contained 0.05% Tween-20 was also sprayed at concentrations of 0, 0.3 and 0.6 mM. Uniconazole at 0.01 mg/pot and STS at 0.6 mM were effective in providing protection against ozone exposure(20h at 0.2ppm) without severe retardation of plant height and chemical phytotoxicity, respectively. Combined treatment with uniconazole, STS significantly reduced ozone injury at the lower concentration than a single treatment with uniconazole or STS. Uniconazole treatment reduced plant height, stem elongation and transpiration rate on a whole plant level and increased chlorophyll concentration. STS did not give any effect on plant growth and chlorophyll content but increased transpiration rate in non-ozone-fumigated plants. Ethylene production in the leaves of ozone-fumigated plants was decreased by uniconazole and STS pretreatment, but there was no protective effect on epinasty of leaves in uniconazole-treated plants. STS increased ethylene production in non-ozone-fumigated plants, but it significantly reduced the degree of epinasty and defoliation of cotyledons when plants were exposed to ozone. Uniconazole slightly increased superoxide dismutase and peroxidase activities. But STS showed little or no effects on such free radical scavengers. Day of flowering after seeding was shortened and percentages of fruit set were increased by uniconazole treatment. STS was highly effective on protecting reduction of fruit set resulting from ozone fumigation. These results suggest that combined use of uniconazole and STS should provide miximum protection against ozone injury without growth retardation resulting in yield loss.

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Chemical Composition and Antimicrobial Efficiency of Swietenia macrophylla Seed Extract on Clinical Wound Pathogens

  • Gopalan, Hanan Kumar;Md Hanafiah, Nor Faizzah;Ring, Leong Chean;Tan, Wen-Nee;Wahidin, Suzana;Hway, Teo Siew;Yenn, Tong Woei
    • Natural Product Sciences
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    • v.25 no.1
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    • pp.38-43
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    • 2019
  • Microbial wound infection prolonged the hospitalization and increase the cost for wound management. Silver is commonly used as antimicrobial wound dressing. However, it causes several adverse side effects. Hence, this study was aimed to evaluate the antimicrobial efficiency of Swietenia macrophylla seed extract on clinical wound pathogens. Besides, the bioactive constituents of the seed extract were also determined. S. macrophylla seeds were extracted with methanol by maceration method. The seed extract inhibited 5 test bacteria and 1 yeast on disc diffusion assay. The antibacterial activity was broad spectrum, as the extract inhibited both Gram positive and Gram negative bacteria. On kill curve analysis, the antibacterial activity of the seed extract was concentration-dependent, the increase of extract concentration resulted in more reduction of bacterial growth. The extract also caused 99.9% growth reduction of Bacillus subtilis relative to control. A total of 21 compounds were detected in gas chromatography- mass spectrometry analysis. The predominant compounds present in the extract were oleic acid (18.56%) and linoleic acid (17.72%). In conclusion, the methanolic extract of S. macrophylla seeds exhibited significant antimicrobial activity on clinical wound pathogens. Further investigations should be conducted to purify other bioactive compounds from the seeds of S. macrophylla.