• Journal of the Optical Society of Korea
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• v.14 no.3
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• pp.282-285
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• 2010

We printed a one-dimensional array of metallic wires and a two-dimensional array of metallic split ring resonators on a photo-paper by using a high-dots-per-inch resolution printer and an ink with silver nano-particles. The printed sample sizes are $1.0{\times}1.0cm^2$. The transmission measured by a terahertz time domain spectroscopy system shows that the arrays of wires and split ring resonators could act as polarizers and band-stop filters, respectively, in a terahertz frequency region.

• Journal of Fashion Business
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• v.12 no.3
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• pp.54-61
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• 2008

The glitter of lame fabrics containing the metallic yarns may further be altered by $Na_2CO_3$ aqueous solution at an elevated temperature. In this study, the effect of the corrosion treatment on the yarn luster was evaluated using image analysis. The alkaline solution treatment was found to be more effective on the aluminum-based specimens than on the silver-based specimens. It was found that corrosion percentage measurement based on the transmission analysis may provide reasonable quantitative index, even if the measurement relies on an indirect method. Based on the quantitative results, the alkaline treatment condition for the specific specimen would be optimized for a desired glitter modification.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.249-249
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• 2015

Silver films have been of considerable interest for years due to their better performance relative to other metal films for engineering applications. A series of multi-layer silver coatings with different thickness (i.e. 0.3 um to 1.5 um) were prepared on Aluminium substrate containing copper undercoat by direct current (DC) magnetron sputtering method. For the comparative purpose, similar thickness silver coatings were prepared by electrolytic deposition method. Microstructural, morphological, and mechanical characteristics of the silver coatings were evaluated by means of scanning electron microscope (SEM), X-ray diffraction (XRD), Surface roughness test, microhardness test and nano-scratch test. From the results, it has been elucidated that the silver films prepared by DC magnetron sputtering method has superior properties in comparison to the wet coating method. On the other hand, DC magnetron sputtering method is relatively easier, faster, eco-friendly and more productive than the electrolytic deposition method that uses several kinds of hazardous chemicals for bath formulation. Therefore, a New Work Item Proposal (NWIP) for the test methods standardization of DC magnetron sputtered silver coatings has recently been proposed via KATS, Korea and a NP ballot is being progressed within a technical committee "ISO/TC107-metallic and other inorganic coating".

• Toxicological Research
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• v.28 no.1
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• pp.25-31
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• 2012

The purpose of this study was to determine the acute pulmonary toxicity of metallic silver nanoparticles (MSNPs, 20.30 nm in diameter). Acute pulmonary toxicity and body distribution of inhaled MSNPs in mice were evaluated using a nose-only exposure chamber (NOEC) system. Bronchoalveolar lavage (BAL) fluid analysis, Western blotting, histopathological changes, and silver burdens in various organs were determined in mice. Mice were exposed to MSNPs for 6 hrs. The mean concentration, total surface area, volume and mass concentrations in the NOEC were maintained at $1.93{\times}10^7$ particles/$cm^3$, $1.09{\times}10^{10}\;nm^2/cm^3$, $2.72{\times}10^{11}\;nm^3/cm^3$, and 2854.62 ${\mu}g/m^3$, respectively. Inhalation of MSPNs caused mild pulmonary toxicity with distribution of silver in various organs but the silver burdens decreased rapidly at 24-hrs post-exposure in the lung. Furthermore, inhaled MSNPs induced activation of mitogen-activated protein kinase (MAPK) signaling in the lung. In summary, single inhaled MSNPs caused mild pulmonary toxicity, which was associated with activated MAPK signaling. Taken together, our results suggest that the inhalation toxicity of MSNPs should be carefully considered at the molecular level.

• Resources Recycling
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• v.26 no.2
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• pp.39-45
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• 2017

In order to exclude the effect of uneven distribution of gold in anode slime, the dissolution of gold and silver from the metal mixture was investigated in different systems, such as the mixture of hydrochloric acid and oxidizing reagents ($H_2O_2$, NaClO and $HNO_3$), thiosulfate and thiourea. In the mixture of HCl and either $HNO_3$ or $H_2O_2$, Au was completely dissolved but the leaching percentage of Ag was around 1%. In both thiosulfate and thiourea solution, gold was not dissolved at all. The presence of ferric ion in acidic thiourea solution showed a favorable effect on the leaching of silver but further study is necessary to elucidate the combined effect of ferric ion and sulfuric acid.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.225-225
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• 2013

Nanostructured noble metals have been attractive for their unusual optical properties and are widely utilized for various purposes. The optical properties mainly originating from collective electron oscillation can assist direct energy conversion via surface plasmon resonances. Here, we investigated the effect of surface plasmons of silver nanowires on the generation of hot electrons. It is reported that the surface plasmons of silver nanowires exhibit longitudinal and transverse modes, depending on the aspect ratio of the nanowires. In order to measure the hot electron flow through the metallic nanowires, chemically modified Au/TiO2 Schottky diodes were employed as the electric contact. The silver nanowires were deposited on a Au metal layer via the spray method to control uniformity and the amount of silver nanowire deposited. We measured the hot electron flow generated by photon absorption on the silver nanowires deposited on the Au/TiO2 Schottky diodes. The incident photon-to-current efficiency was measured a function of the photon energy, revealing two polarization modes of siliver nanowires: transverse and longitudinal modes. UV-Vis spectra exhibited two polarization modes, which are also consistent with the photocurrent measurements. Good correlation between the IPCE and UV-vis measurements suggests that hot electron measurement on nanowires on nanodiodes is a useful way to reveal the intrinsic properties of surface plasmons of nanowires.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.6039-6046
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• 2015

Aims: To investigate effect of metallic nanoparticles, silver (AgNPs) and gold nanoparticles (AuNPs) as antitumor treatment in vitro against human breast cancer cells (MCF-7) and their associated mechanisms. This could provide new class of engineered nanoparticles with desired physicochemical properties and may present newer approaches for therapeutic modalities to breast cancer in women. Materials and Methods: A human breast cancer cell line (MCF-7) was used as a model of cells. Metallic nanoparticles were characterized using UV-visible spectra and transmission electron microscopy (TEM). Cytotoxic effects of metallic nanoparticles on MCF-7 cells were followed by colorimetric SRB cell viability assays, microscopy, and cellular uptake. Nature of cell death was further investigated by DNA analysis and flow cytometry. Results: Treatment of MCF-7 with different concentrations of 5-10nm diameter of AgNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $6.28{\mu}M$, whereas treatment of MCF-7 with different concentrations of 13-15nm diameter of AuNPs inhibited cell viability in a dose-dependent manner, with IC50 value of $14.48{\mu}M$. Treatment of cells with a IC50 concentration of AgNPs generated progressive accumulation of cells in the S phase of the cell cycle and prevented entry into the M phase. The treatment of cells with IC50 concentrations of AuNPs similarly generated progressive accumulation of cells in sub-G1 and S phase, and inhibited the entrance of cells into the M phase of the cell cycle. DNA fragmentation, as demonstrated by electrophoresis, indicated induction of apoptosis. Conclusions: Our engineered silver nanoparticles effectively inhibit the proliferation of human breast carcinoma cell line MCF-7 in vitro at high concentration ($1000{\mu}M$) through apoptotic mechanisms, and may be a beneficial agent against human carcinoma but further detailed study is still needed.

• Journal of the Korean Graphic Arts Communication Society
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• v.16 no.1
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• pp.25-38
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• 1998

The developing agent is the materials which first acts on silver grain and make it into metallic silver by reducing reaction. There are several types in developing agent, and according to Lumiere-Andresen principle, substitution product which has amino or hydroxyl group in benzen nucleus has a developing power, but all reduing substances are not in used. In the developing effect, not only the role of developing agent but also that of assistant materials are important. But in this work, we have studied effect, change by lith developing agent which require high contrast image. We made an developing experiment after having manufactured developing solution used hydroquinone and another developing agents like chlorohydroquinone, pyrocatechol and pyrogallol as developing agent. And we added that did in addition of diethanolamine and ascorbic acid, and then we examined the possibility of use.

• Proceedings of the Korean Fiber Society Conference
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• 2003.10b
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• pp.173-174
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• 2003

Activated carbons (ACs) are widely used in adsorption for the removal of gaseous and aqueous pollutants[1,2]. The microbicidal property of ACs is also very important, in order to decrease the risk of water and air contamination with microorganisms. For this purpose, ACs have impregnated with silver or with metallic oxides[2]. However, in the case of Ag supported ACs prepared by impregnation, there are some problem, such as, heat-treatment, highly decrease in specific surface area and pore volume by deposited Ag, and rapidly elution of Ag at the initial stage of usage[3]. (omitted)

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.727-732
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• 1998

Ag-deposited graphite powder was prepared by a chemical reduction method of metal particles onto graphite powder. X-ray diffraction observation of Ag-deposited graphite powder revealed that silver existed in a metallic state, but not in an oxidized one. From SEM measurement, ultrafine silver particles were highly dispersed on the surface of graphite particles. Cylindrical lithium ion secondary battery was manufactured using Ag-deposited graphite anodes and $LiCoO_2$ cathodes. The cycleability of lithium ion secondary battery using Ag-deposited graphite anodes was superior to that of original graphite powder. The improved cycleability may be due to both the reduction of electric resistance between electrodes and the highly durable Ag-graphite anode.