• Title/Summary/Keyword: new-silver

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Synthesis of Silver Nanocrystallites by a New Thermal Decomposition Method and Their Characterization

  • Lee, Don-Keun;Kang, Young-Soo
    • ETRI Journal
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    • v.26 no.3
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    • pp.252-256
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    • 2004
  • We formed silver nanocrystallites by the thermal decomposition of a $Ag^{+1}$-oleate complex, which was prepared by a reaction with $AgNO_{3}$ and sodium oleate in a water solution. The resulting monodispersed silver nanocrystallites were produced by controlling the temperature (290$^{\circ}$C). Transmission electron microscopic (TEM) images of the particles showed a 2-dimensional assembly of the particles with a diameter of $9.5{\pm}0.7nm$, demonstrating the uniformity of these nanocrystallites. An energy-dispersive X-ray (EDX) spectrum and X-ray diffraction (XRD) peaks of the nanocrystallites showed the highly crystalline nature of the silver structure. We analyzed the decomposition of the $Ag^{+1}$-oleate complex using a Thermo Gravimetric Analyzer (TGA) and observed the crystallization process using XRD.

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Application of Biosynthesized Silver Nanoparticles Against a Cancer Promoter Cyanobacterium, Microcystis aeruginosa

  • El-Sheekh, Mostafa Mohamed;El-Kassas, Hala Yassin
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.16
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    • pp.6773-6779
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    • 2014
  • Background: Nanotechnology opens new applications in many fields including medicine. Among all metallic nanoparticles, silver nanoparticles (silver NPS) have proved to be the most effective against a large variety of organisms including toxic cyanobacteria. Materials and Methods: Silver NPs were biosynthesized in vivo with different alga species namely, Spirulina piatensis, Chlorella vulgaris and Scenedesmus oh/iquus following two scenarios. First: by suspending a thoroughly washed algae biomass in 1 mM aqueous $AgN0_3$ solution. Second: by culturing them individually in culture media containing the same concentration of $AgN0_3$. Silver NPs were characterized using UV-Vis spectroscopy, transmission electron microscopy (TEM), energy dispersive analysis (EDX) and Fourier transform infra-red (FfIR) spectroscopy. The biosynthesized silver NPs were tested for cytotoxic activity against a cancer promoter cyanobacteruim Microcystis aeruginosa, considering effects on cell viability and chlorophyll content. Results: The surface plasmon band indicated the biosynthesis of silver NPs at ~400 nm. Transmission electron microscopy (TEM) revealed that the silver NPs had a mean average size below 100 nm. Energy-dispersive analysis X-ray (EDX) spectra confirmed the presence of silver element. FfIR spectral analyses suggested that proteins and or polysaccharides may be responsible for the biosynthesis of silver NPs and (-COO-) of carboxylate ions is responsible for stabilizing them. The toxic potentialities ofthe biosynthesized silver NPs against the cancer promoter cyanobacterium, Microcystis aeruginosa showed high reduction in viable cells count and the total chlorophyll content. Conclusions: The potential activity of the biosynthesized silver NPs from the studied algae species against Microcystis aernginosa cells is expected to be mainly mediated by the release of silver ions (Ag+) from the particle surface and bioactive compounds as indicated by FfIR analysis.

A Study on the Composition of Silver Paste for Micro Nozzle Dispensing Method (미세노즐 토출에 적용 가능한 은 전극의 조성에 대한 연구)

  • Kim, Do-Hyung;Shin, Dong-Wook;Ryu, Sung-Soo;Chang, Hyo-Sik;Kim, Hyeong-Jun
    • New & Renewable Energy
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    • v.8 no.1
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    • pp.18-23
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    • 2012
  • The screen printing has been widely used to form silver electrodes in solar cell device due to their simplicity of process. However, the wavy and irregular surface which is believed to be originated from a screen mask mesh and thixotropic characteristics of paste on screen printing process is well-known to give a negative effect on solar cell efficiency. The dispensing method that the silver paste is extruded through micro nozzle under a moderate pressure and coated on substrate can form the silver electrode without any wavy surface. In this study, we optimize the composition of silver paste and develop paste blending condition based on the thixotropic behavior of paste. The optimized paste shows a large thixotropic loop area which is related to an aspect ratio of electrode line and has the viscosity of 40 $Pa{\cdot}s$ at 40 s-1. The electrode line we finally obtainis 67.2 ${\mu}m$ in width and has an aspect ratio of 0.277.

The Effects of Perception of Fun Factors for Participation in Park Golf on Psychological Happiness and Behavioral Intentions : Focusing on the New Silver Generation (파크골프 참여에 대한 재미요인 인지가 심리적 행복감 및 행동 의도에 미치는 영향 : 뉴실버세대를 중심으로)

  • Woo-Sik Kim
    • Journal of the Korean Applied Science and Technology
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    • v.41 no.3
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    • pp.555-564
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    • 2024
  • In this study, a total of 255 New Silver Generations residing in Chungcheong Province were analyzed from September 16 to December 10, 2023 to find out how the fun factors of park golf, which has established itself as a representative silver sport, affect psychological well-being and behavioral intentions. First, it was found that the fun factor had an effect on psychological well-being. Second, it was found that the fun factor influenced the behavioral intention. Finally, it was found that the psychological well-being of park golf participants had a significant effect on the intention of action. In fact, it was found through the results of the study that park golf participants felt psychological well-being according to the fun factor and were also related to future actions. Recognizing that it is the time when it is required to understand the range of New Silver people's behavior and provide customized programs to encourage participation, it is also necessary to devise a plan to activate it as a daily sport.

Preparation of New Polyelectrolyte/ Silver Nanocomposites and Their Humidity-Sensitive Properties

  • Park, Min-Su;Lim, Tae-Ho;Jeon, Young-Min;Kim, Jong-Gyu;Gong, Myoung-Seon;Joo, Sang-Woo
    • Macromolecular Research
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    • v.16 no.4
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    • pp.308-313
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    • 2008
  • A simple strategy was developed based on polyelectrolyte/silver nanocomposite to obtain humidity-sensitive membranes. The major component of a humid membrane is the polyTEAMPS/silver nanocomposite obtained by thermal heating the mixture of a polyelectrolyte and silver isopropylcarbamate complex. Humidity sensors prepared from polyTEAMPS/silver (w/w=100/0 and 100/6) nanocomposites had an average impedance of 292, 8.83 and $0.86\;k{\Omega}$, and 5,327, 140 and $0.93\;k{\Omega}$ at 30,60 and 95% relative humidity (RH), respectively. Hysteresis, temperature dependence and response time were also measured. Activation energies and complex impedance spectroscopy of the various components of the polyelectrolyte/silver nanocomposite films were examined for the humidity-sensing membrane.

Silver Alloying Process for Mokumegane-like Effect for Jewelry Design (장신구 디자인을 위한 모꾸메가네 효과 은 합금 공정)

  • Song Oh-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.7 no.3
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    • pp.506-511
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    • 2006
  • Silver is one of the most appropriate Jewelry materials for Jewelry casting and bench working. The technique known as 'Mokumegane' is good for making silver jewelry with natural patterns, such as wood grain patterns, but the process is not easy for silversmithing because it requires complicated and heavy labour. Instead of using conventional Mokumegane technique, we propose a new modified silver-copper casting process that enables a similar surface effect with good metal bonding strength between silver and copper. Simply pouring the molten silver into pre-aligned copper granules or 0.5 mm to 1.5 mm-thick copper sheets leads to well embedded copper silver ingots. The rolled silver plates from those ingots show excellent bonding interface even after the silver plate rolled ten times. We successfully fabricated prototype rings with copper embedded silver plates. Our result implies that our newly proposed process nay be a simpler way to fabricate silver jewelry with a pseudo-Mokumegane effect.

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Electrospun Antimicrobial Polyurethane Nanofibers Containing Silver Nanoparticles for Biotechnological Applications

  • Sheikh, Faheem A.;Barakat, Nasser A.M.;Kanjwal, Muzafar A.;Chaudhari, Atul A.;Jung, In-Hee;Lee, John-Hwa;Kim, Hak-Yong
    • Macromolecular Research
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    • v.17 no.9
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    • pp.688-696
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    • 2009
  • In this study, a new class of polyurethane (PU) nanofibers containing silver (Ag) nanoparticles (NPs) was synthesized by electrospinning. A simple method that did not depending on additional foreign chemicals was used to self synthesize the silver NPs in/on PU nanofibers. The synthesis of silver NPs was carried out by exploiting the reduction ability of N,N-dimethylformamide (DMF), which is used mainly to decompose silver nitrate to silver NPs. Typically, a sol-gel consisting of $AgNO_3$/PU was electrospun and aged for one week. Silver NPs were created in/on PU nanofibers. SEM confirmed the well oriented nanofibers and good dispersion of pure silver NPs. TEM indicated that the Ag NPs were 5 to 20 nm in diameter. XRD demonstrated the good crystalline features of silver metal. The mechanical properties of the nanofiber mats showed improvement with increasing silver NPs content. The fixedness of the silver NPs obtained on PU nanofibers was examined by harsh successive washing of the as-prepared mats using a large amount of water. The results confirmed the good stability of the synthesized nanofiber mats. Two model organisms, E. coli and S. typhimurium, were used to check the antimicrobial influence of these nanofiber mats. Subsequently, antimicrobial tests indicated that the prepared nanofibers have a high bactericidal effect. Accordingly, these results highlight the potential use of these nanofiber mats as antimicrobial agents.

Role of Physical Therapist in Silver Industry (실버산업에서 물리치료사의 역할)

  • Kim Yang-Hee;Seo Yeon-Soon;Lee Gin-Hee
    • The Journal of Korean Physical Therapy
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    • v.8 no.1
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    • pp.99-108
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    • 1996
  • The purpose of this review are to determine of role of physical therapist in silver industry, and to give the information about elderly person when silver industry will be needed in 21 centry. Current literature so physiological changes that occur in humans owing to aging is reviewed. Also, psychological changes are discussed. There are main important roles in silver industry. One is proper exercise prescription for helth care and the other is effective therapy for the various disease. It will help the elderly person who needs independent ADL.

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Purchasing Behavior of Hairdressing Services on Cognitive Age of Silver Consumers (실버 소비자들의 주관적 연령에 따른 미용 서비스 구매 행동)

  • Kang, Eun-Mi;Park, Eun-Joo
    • The Research Journal of the Costume Culture
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    • v.16 no.4
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    • pp.762-774
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    • 2008
  • Recently, silver consumers were became new consumption market. The purpose of this study were to find out the relationships among cognitive age and variables related to hairdressing purchases in hairdressing shop. Data were obtained from 853 women in the 50's and 60's who living in Busan. Data were analyzed by frequency analysis, descriptive analysis, factor analysis, Cronbach's alpha and, $X^2$-test, t-test using SPSS WIN 12.0. The results of the study were as follows: First, Service quality of hairdressing shop were consisted of Personal Service, Facilities Service, Skill Service, and Policy Service. Second, Silver consumers' cognitive age influenced purchase behavior of hairdressing services. Most of respondents were perceived themselves to be younger than their chronological ages. Repurchasing intention of silvers who were active and self-fidelity or perceived themselves cognitively younger were more likely to be influenced by store service quality and consumer satisfaction. This study provides an insight into silver fashion marketers and retailers for developing market strategies for silver fashion market. Implications are drawn for the information useful to consumer behavior researchers and retailers of the silver fashion market.

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A Study on Brassiere Development for the New Silver Generation Women (뉴실버세대 여성을 위한 브래지어 개발)

  • Park, Ja Young;Jang, Jeong Ah
    • Fashion & Textile Research Journal
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    • v.17 no.3
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    • pp.429-439
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    • 2015
  • This study develops a new brassiere for new silver women. A new brassiere design was developed for the silver generation based on apreliminary survey; subsequently, a wire and no-wire type of brassier were developed after a second fitting evaluation. The results were as follows. First, in terms of brassiere design, the cup shape was designed as mold type full cup, shoulder straps were designed as camisole type with cups, bias tape was designed for body correction in the side line and mash tape was designed for easy movement below the cups. On the other side ofthe cup shape was a pocketdesigned on a support pad forthe wire type and a support panel to serve as a wire in the no-wire type brassiere. Second, brassiere patterns were designed by referencing the educational H pattern. Thetotal length was elongated by 5cmto reduce pressure when wearing a brassiere and the height of the front center increased by 8cm for the stability of the front center of the brassiere. In addition, the side line was moved back by 3cm and the width of the brassiere wings was designed widely at 10.5cm. Third, a wearing test was conducted for the wire type and the no-wire type brassiere with comparison products, using a 7-point Likert scale. Appearance results and movement tests for the wire and no-wire type showed a higher score than comparison products.