• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.1
• /
• pp.43-48
• /
• 2015

Silver nanowire (AgNW) is a material that is increasingly being used for transparent electrodes, as a substitute for indium tin oxide (ITO), owing to its flexibility, high transmittance to sheet resistance ratio, and simple production process. This study involves manufacturing large-area organic photovoltaic cells (OPVs) deposited on AgNW electrodes. We compared the efficiency of OPVs with ITO and AgNW electrodes. The results verified that an OPV with an AgNW electrode performed better than that with an ITO electrode. Furthermore, by using the knife coating method, we successfully fabricated large-area OPVs without the loss of efficiency. Use of AgNW instead of ITO demonstrated that an OPV could be produced on various substrates by the solution process method, dropping the productions costs significantly. Additionally, by using the knife coating method, the process time and amount of wasted solution are reduced. This leads to an increase in the efficient fabrication of the OPV.

• Korean Journal of Animal Reproduction
• /
• v.14 no.2
• /
• pp.147-154
• /
• 1990

To study effects of intratesticular injection of AgNO3 and latic acid solution(ALS) on castration, 50 heads of crossbred(Large Yorkshire$\times$Landrace) pigs were used. ALS(1% or 5% in concentration) was injected(0.2ml or 0.5ml in amout) to testes of pigs(weighing 7.7kg) unilaterally or bilaterally and changes of scrotum size, residual concentration of Ag, and steroid concentration in the blood were measured. The results obtained are summarized as follows : 1. The size of testis became swollen significantly(p<0.01) on the 3rd day after the treatment and then reduced to the same size before the treatment on the 26th day. 2. The residual concentration of Ag in the bilaterally treated pigs was similar to that of the control pigs, while it was lower in the unilaterally treated pigs than in the control pigs except the 1%-0.2ml treated pigs whose concentration was similar to that of the control pigs. 3. In 92 days after the bilateral injection, the testosterone concentration was higher significantly(p<0.01) in the 5%-0.5ml treated pigs than in the control pigs. However, in 120 days it was lower significantly(p<0.05) in the treated pigs than in the control pigs. 4. In 92 days after the bilateral treatment, the androstenedione concentration was lower significantly(p<0.01) in the 1%-0.5ml treated pigs than in the control pigs and it was also lower significantly(p<0.05) in the 1% or 5% treated pigs than in the control pigs on the 120th day after the treatment.

• Journal of the Korean Ceramic Society
• /
• v.38 no.11
• /
• pp.1055-1059
• /
• 2001

Porous glass ceramics composed of Li$_2$O.-Ti $O_2$-P$_2$ $O_{5}$ -CaO were prepared by melting and 2 step heat treatment for nucleation at 61$0^{\circ}C$ and crystallization at 78$0^{\circ}C$. subsequently $\beta$-Ca$_3$(P $O_4$)$_2$crystal phase was selectively leached out in 1N-HC1 solution for 3 days, leaving Li $Ti_2$(P $O_4$)$_3$crystal phases. prepared porous glass ceramics were immersed in 1M AgN $O_3$solution for ion exchange. Staphylococcus aureus and salmonella typhi were used in this study. It was found taht the resultant porous glas ceramics show excellent bacteriostatic properties.

• Korean Journal of Metals and Materials
• /
• v.48 no.12
• /
• pp.1097-1102
• /
• 2010

Silver coated copper powders were prepared by a chemical reduction method with controlling the deposition process variables such as the feeding rate of the silver ionic solution and concentration of the reductants at room temperature. The characteristics of the products were evaluated by scanning electron microscope (SEM), X-ray diffractometer (XRD), atomic absorption spectrophotometer (AA) and a 4 probe resistivity measurement system. The optimum condition of the preparation of Ag coated Cu powders was at 0.05 M of potassium sodium tartrate and 2 ml/min of the feeding rate of the silver ionic solution. Our method successfully produced dense, uniform, and well-dispersed Ag coated Cu powder of $2{\sim}2.5{\mu}m$ witha silver layer of 100~200 nm. Additionally, we found that thespecific resistivity of the 30 wt.% Ag coated Cu powder was similar to that of pure silver, so that the composite powder could be used as an alternative electromagnetic shielding material for silver.

• Journal of the Korean GEO-environmental Society
• /
• v.17 no.2
• /
• pp.5-11
• /
• 2016

$MWCNT-TiO_2$ nano composites and $Ag-MWCNT-TiO_2$ nano composites were prepared from Multi-Walled Carbon NanoTube (MWCNT), titanium (IV) butoxide (TNB) solution and silver nitrate ($AgNO_3$) by the sol-gel method. The dispersion and structure of Ag in the synthesized composites was observed by Scanning Electron Microscopy (SEM) and Field Emission Transmission Electron Microscopy (FE-TEM). X-Ray Diffraction (XRD) patterns of the composites showed that the composites contained an anatase phase. The Energy Dispersive X-ray spectroscopy (EDX) showed the presence of C, O, Ti and Ag peaks. The $TiO_2$ particles were distributed uniformly in the MWCNT network, and Ag particles were virtually fixed on the surface of the tubes. Also decomposition of the methylene blue was investigated according to UV radiation times for study photocatalytic activity. $Ag-MWCNT-TiO_2$ nano composites show high photodegradation than $MWCNT-TiO_2$ nano composites. The results indicate that the high conductivity of Ag improved the photoactivity of the $MWCNT-TiO_2$ composite.

• Journal of Pharmaceutical Investigation
• /
• v.31 no.4
• /
• pp.273-279
• /
• 2001

The purpose of this study is to characterize the iontophoretic transport of growth hormone releasing peptides (GHRP-6) through hairless mouse skin from aqueous solution. The effect of various factors, such as pH, poloarity, current profile, current density, current duration, ionic strength, drug concentration, and enhancer application was studied to obtain basic knowledge on the transport. We have also studied the stability of GHRP-6 in solution with/without current. The donor chamber was filled with phosphate buffer solution containing GHRP-6 and the receptor chamber was filled with phosphate buffer solution (pH 7.4). Ag/AgCl electrode was used for their stability and reversibility. At a predetermined time interval, sampling was made and the concentration of drug was analysed using HPLC system. The results showed that, compared to passive flux, the total amount of drug transported increased markedly by the application of anodal current. Cathodal flux was similar to passive flux. Flux increased with the current density, the duration of current application and drug concentration. The effect of enhancers on the flux was studied using hydrophilic (5% N-methyl pyrrolidone) and hydrophobic (5% propylene glycol monolaurate, 5% oleic acid) enhancers. Application of enhancer also increased the flux.

• Journal of the Korean institute of surface engineering
• /
• v.29 no.2
• /
• pp.140-145
• /
• 1996

Silver deposits formed on copper substrates by replacement reactions show poor adhesion, and a silver film plated on such a deposit does not adhere. Silver ion makes a highly stable complex with cyanide ion, so that in a silver cyanide solution, the activity of silver ion is very small. This is one of the reasons for the universal use of cyanide baths in the industrial silver plating. However, the consideration of the difference between the values of the stability constants for bath the silver-iodide complex and the copper-iodide complex suggest that the rate of replacement deposition of silver on the copper substrate in si]ver-potassium iodide solution, could be comparatively low. To confirm this, the rate of replacement deposition of silver in both a silver-potassium iodide solution ($AgNO_3$0.10 mol/L, KI 2.00 mol/L ) and a strike silver plating bath (AgCN 0.028 mol/L, KCN 1.15 mol/L ) was estimated from the current density corresponding to the point of intersection of the anodic and the cathodic polarization curves. These estimated values were almost the same, and it is suggested that the silver-potassium iodide solution is not only a cyanide free silver plating bath capable of employing a copper substrate but a silver plating bath which requires no strike plating.

• Journal of Korean Ophthalmic Optics Society
• /
• v.3 no.1
• /
• pp.217-222
• /
• 1998

Coating films of $SiO_2-TiO_2-AgO$ have been prepared on soda-lime-silica slide glasses and single crystal silicon wafer by the sol-gel method using a spin-coating technique. Commercially available tetraethyl orthosilicate, titanium trichloride, and silver-nitrates were used as starting materials. The heat treatment temperature of this coating films was $500^{\circ}C$ properly, obtained from TG-DTA result. The films with thickness of 310 nm were prepared by 5 times coating. In the case of l0 mol% AgO, the film showed a crack-free and smooth surface, but the higher Ago content exhibited the more pin hole and the segregated cluster of AgO. The IR absorbance of the films decreased in the range of 400 nm to 700 nm with the increase of annealing temperature. And the reflectance of the coating films decreased and the color was changed light yellow to white yellow with the increase of Ago content.

• Journal of Microbiology and Biotechnology
• /
• v.26 no.11
• /
• pp.1933-1942
• /
• 2016

A novel ${\alpha}-glucoside$ hydrolase (named PspAG97A) from glycoside hydrolase family 97 (GH97) was cloned from the deep-sea bacterium Pseudoalteromonas sp. K8, which was screened from the sediment of Kongsfjorden. Sequence analysis showed that PspAG97A belonged to GH97, and shared 41% sequence identity with the characterized ${\alpha}-glucoside$ BtGH97a. PspAG97A possessed three key catalytically related glutamate residues. Mutation of the glutamate residues indicated that PspAG97A belonged to the inverting subfamily of GH97. PspAG97A showed significant reversibility against changes in salt concentration. It exhibited halophilic ability and improved thermostability in NaCl solution, with maximal activity at 1.0 M NaCl/KCl, and retained more than 80% activity at NaCl concentrations ranging from 0.8 to 2.0 M for over 50 h. Furthermore, PspAG97A hydrolyzed not only ${\alpha}-1,4-glucosidic$ linkage, but also ${\alpha}-1,6-$ and ${\alpha}-1,2-glucosidic$ linkages. Interestingly, PspAG97A possessed high catalytic efficiency for long-chain substrates with ${\alpha}-1,6-linkage$. These characteristics are clearly different from other known ${\alpha}-glucoside$ hydrolases in GH97, implying that PspAG97A is a unique ${\alpha}-glucoside$ hydrolase of GH97.

• Analytical Science and Technology
• /
• v.11 no.2
• /
• pp.125-129
• /
• 1998

The purpose of this study was to give a quantitative analysis for assessing the tarnish resistance of alloys at the artificial saliva, 0.9% NaCI solution and Ringer's solution. In light of development in low-nobility alloys, it is important that tarnish test is standardized to analyse the tarnish properties of the compositions. There are concerns with the long term chemical stability of these alloys and the resistance to tarnish. Chemical stability is a complex problem involving alloy composition, nobility, microstructure and environment.