• Transactions on Electrical and Electronic Materials
• /
• v.18 no.4
• /
• pp.217-220
• /
• 2017

We deposited transparent conductive ZTO/Ag/ZTO trilayer thin films on glass substrates through magnetron sputtering, and then conducted intense electron beam irradiation on their surfaces to investigate the effects of electron irradiation on the structural, optical, and electrical properties of these films. After deposition, we electron irradiated the ZTO/Ag/ZTO films for 10 min at electron energies of 300, 500, and 700 eV. The films that were electron irradiated at 700 eV showed a higher optical transmittance (84.2%) in the visible wavelength region and a lower resistivity ($7.2{\times}10^{-5}{\Omega}cm$) compared with the other films. The figure of merit revealed that the ZTO/Ag/ZTO films that were electron irradiated at 700 eV had a higher optical and electrical performance than the other films prepared in this study.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.46 no.4
• /
• pp.28-36
• /
• 2014

We studied the green synthesis and antibacterial activity of paper coated with chitosan-silver (Ag) green nanocomposites for packaging applications. Green synthesis of Ag nanoparticles (AgNPs) was achieved by a chemical reaction involving a mixture of chitosan-silver nitrate ($AgNO_3$) in an autoclave at 15 psi, $121^{\circ}C$, for 30 min. AgNPs and their formation in chitosan was confirmed by UV-Vis spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering (DLS). As-prepared chitosan-AgNPs composite materials were coated on manila paper using Meyer rod. Surface morphology and Ag contents in coating layer were characterized by field emission scanning electron microscopy (FESEM) and energy dispersive spectroscopy (EDS). The mechanical properties such as tensile strength and elongation were significantly affected by coating with chitosan-AgNPs. The antibacterial test of coated paper was performed qualitatively and quantitatively against Escherichia coli (E. coli). It was shown to be effective in suppressing the growth of E. coli with increasing Ag contents on the surface of coated paper and more than 95 R (%) of antimicrobial rate was obtained at chitosan-AgNPs coated papers.

• Analytical Science and Technology
• /
• v.11 no.4
• /
• pp.248-253
• /
• 1998

The adsorption and separation behaviors of alkali, alkaline earth and transition metal ions using a poly-dibenzo-18-crown-6 were investigated in aqueous solution. The adsorption degree(E) and distribution ratio(D) of alkali, alkaline earth metal ions were Li(I)$t_R$) of metal ions were affected by the adsorption degree(E) and distribution ratio(D). This results showed good separation efficiency of K(I), Sr(II), Ag(I) and Pb(II) from the mixed metal solution.

• Journal of the Korean Magnetics Society
• /
• v.15 no.4
• /
• pp.217-220
• /
• 2005

The electronic structure and magnetism of Fe chain along the [110] direction on Ag(001) were investigated by using the all-electron full-potential linearized augmented plane wave (FLAPW) method within generalized gradient approximation (GGA). The magnetic moment of Fe atom in Fe chain is calculated to be $3.02\;{\mu}_B$, which is slightly larger than that ($2.99\;{\mu}_B$) of the Fe[110] chain on Cu(001). The reduced coordination number for the Fe chain induced the Fe-d band narrowing and exchange-splitting enhancement, which are responsible for the large magnetic moment of the Fe chain. The calculated band width of the Fe-d band and the exchange-splitting are 1.7 eV and 3.2 eV, respectively.

• Korean Journal of Materials Research
• /
• v.12 no.7
• /
• pp.587-590
• /
• 2002

A silver indium sulfide ($AgInS_2$) epilayer was grown by the hot wall epitaxy method, which has not been reported in the literature. The grown $AgInS_2$ epilayer has found to be a chalcopyrite structure and evaluated to be high quality crystal. From the photocurrent measurement in the temperature range from 30 K to 300 K, the two peaks of A and B were only observed, whereas the three peaks of A, B, and C were seen in the PC spectrum of 10 K. These peaks are ascribed to the band-to-band transition. The valence band splitting of $AgInS_2$ was investigated by means of the photocurrent measurement. The crystal field splitting, $\Delta_{cr}$ , and the spin orbit splitting, $\Delta_{so}$ , have been obtained to be 0.150 eV and 0.009 eV at 10 K, respectively. And, the energy band gap at room temperature has been determined to be 1.868 eV. Also, the temperature dependence of the energy band gap, $E_{g}$(T), was determined.d.

• Applied Chemistry for Engineering
• /
• v.18 no.4
• /
• pp.396-399
• /
• 2007

In present work, the anti-bacterial effect of silver/activated carbon (Ag/C) composites prepared by the ${\gamma}$-irradiation of $AgNO_3$ solution on Escherichia coli (E. coli) has been studied. Characteristics of the Ag/C composites were identified by scanning electron microscopy (SEM), X-ray diffraction (XRD) and atomic absorption spectroscopy (AAS). The inhibitory concentration of E. coli was found to be 0.387 ppm and the sterilizing concentration for the tested organism was 1.017 ppm. These results support the evidence that Ag/C composites have strong antibacterial activity to E. coli.

• Proceedings of the KIEE Conference
• /
• 1998.07a
• /
• pp.349-352
• /
• 1998

In future superconducting electrical machines and device. AC loss in the superconducting windings are one of the most impotent design paramenters. This paper descriptions a series of Characteristic of a high-Tc superconducting Bi-Pb-Sr-Ca-Cu-O Ag-sheathed filament. In the case simulation and design to reduce ac loss is considered the filament number, twitch pith number and diameter of filament. A filament sample with Tc of 78K is made by $835^{\circ}C$ sintering for 50h and $0.33^{\circ}C$/min heating rate in an atmosphere. The experiment observations are compared with self-field loss and AC losses of Bi-Pb-Sr-Ca-Cu-O filament at 77K in following environments ; (i)AC external parallel magnetic field in different frequencies. And an analytical expression of the loss the derivation of transposition from an optimum condition was derived for the external AC magnetic field, theoretical predictions were found to coincide with the experimental observations.

• Applied Chemistry for Engineering
• /
• v.23 no.3
• /
• pp.293-296
• /
• 2012

Nanocomposites were fabricated as titanium dioxide ($TiO_2$) doped with nanometals (Au, Ag) by sonochemical reduction method and sol-gel method in order to investigate their antimicrobial activities. Then, the antimicrobial activity of the resulting samples was compared by the measurement of colony numbers survived on the agar plate incubated for 24 h after the loading E. coli on the solid-state media with the nanocomposites. The initial antimicrobial activity of the metal (Au, Ag)-doped $TiO_2$ was higher than that of the pristine $TiO_2$. Afterwards the nanocomposite samples were kept at $4^{\circ}C$ for a long time and the aged samples exhibited the different antimicrobial activity. With the elapse of aging times, Ag-doped $TiO_2$ with $TiO_2$ coating ($Ag-TiO_2$@$TiO_x$) exhibited the higher antimicrobial activity than those of $Ag-TiO_2$and $Au-TiO_2$. The $TiO_2$ coating on the $Ag-TiO_2$ may prevent the oxidation of Ag nanometals and stabilize colloidal nanocomposites.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2013.02a
• /
• pp.351-351
• /
• 2013

한국 전체 에너지 사용량 중약 24%의 에너지가 건축물 부분에 소비되고 있다. 건축물의 벽체나 유리창 등을 통해서 에너지 손실이 이루어지는데 유리창은 벽체에 비해 약 10배 이상 낮은 단열 특성을 가지고 있기 때문에 유리창을 통한 열손실량은 더 크다. 이러한 유리창 부분의 열손실 문제를 해결할 수 있는 방안으로 좋은 단열 특성 및 낮은 방사율을 가지고 있는 Low-e coating 방법을 사용하였다. 본 실험에서는 XG glass 기판 위에 IGZO/Ag/IGZO OMO 구조의 다층 박막을 증착하였다. RF magnetron sputtering방법을 이용하여 OMO 구조의 상부와 하부의 Oxide layer로 IGZO 박막을 증착하였다. 사용된 IGZO 타겟은 $In_2O_3$ (99.99%), $Ga_2O_3$ (99.99%), ZnO (99.99%)의 분말을 각각 1:1:1 mol% 조성비로 혼합하여 소결하여 제작하였다. Thermal Evaporator 장비를 이용하여 OMO 구조의 Metal layer로 Ag (99.999%)를 증착하였다. 실험 기판은 크기 $30{\times}30mm$의 0.7T XG glass를 사용하였다. OMO 구조의 산화층 IGZO 박막은 상/하층 동일 조건으로 기판 온도는 실온으로 고정하였으며, 초기 압력 $3.0{\times}10^{-6}$ Torr, 증착 압력 $3.0{\times}10^{-2}$ Torr, RF 파워 50W, Ar 유량 50 sccm로 고정시키고 증착 시간이 변화하면서 박막을 증착하였다. OMO 구조의 Metal layer로 Ag 증착 조건은 초기 진공도가 약 $6.0{\times}10^{-6}$ Torr 이하로 유지하고 기판을 2 Rpm의 속도로 회전시켰다. 이후 0.3 V로 Ag를 10분간 가열하여 충분히 녹인 후 Film Thickness Monitor로 두께를 확인하였다. OMO 다층 박막의 산화물층 변화에 따라 로이다층 박막의 구조적, 광학적 및 전기적 특성을 분석하였다. XRD 분석결과에 의하여 Bragg's 법칙을 만족하는 피크가 나타나지 않는 비정질 구조임을 확인할 수 있으며, AFM 분석결과에 통해서 최소 1.3 nm의 Roughness를 나타내었다. UV-Visible-NIR 분광광도계를 이용하여 다층 박막은 가시광선 영역에서 평균 80%의 광 투과성을 보여 IR 영역에서 평균 30% 투과하고 좋은 차단 특성을 나왔다. Low-e 특성을 갖는 유리창을 통해서 에너지 절약을 이룰 수 있는 것을 확인할 수 있었다.

• KSBB Journal
• /
• v.17 no.1
• /
• pp.63-67
• /
• 2002

Silver-alginate and copper-alginate were prepared with Na-alginate extracted from marine brown algae(Sargassum fluitans). The antibacterial effect of Ag-alginate or Cu-alginate against Staphylococcus aureus and Escherichia coli was carried out by measuring optical density of liquid culture at 600 nm. The cell growth of Staphylococcus aureus and Escherichia coli was very active at pH 7, and was inhibited by adding Ag-alginate with more than 0.006 wt.% of silver content. The antibacterial effect of Ag-alginate against S. aureus and E. coli was better than that of Cu-alginate at the same metal concentration. The cell growth of S. aureus was less inhibitory than E. coli at the same concentration of Ag-alginate. The cell growth of S. aureus and E. coli was also influenced by the characteristics of counter ion of silver.