• Proceedings of the Korean Society of Life Science Conference
• /
• 2006.09a
• /
• pp.33.2-33.2
• /
• 2006

• Advances in aircraft and spacecraft science
• /
• v.4 no.6
• /
• pp.729-744
• /
• 2017

This investigation highlights rationale of electrically conductive nano adhesives for its essential application for Electromagnetic Interference (EMI) Shielding in satellites and Lightning Strike Protection in aircrafts. Carbon Nano Fibres (CNF) were functionalized by electroless process using Tollen's reagent and by Plasma Enhanced Chemical Vapour Deposition (PECVD) process by depositing silver on CNF. Different weight percentage of CNF and silver coated CNF were reinforced into the epoxy resin hardener system. Scanning Electron Microscopy (SEM) micrographs clearly show the presence of CNF in the epoxy matrix, thus giving enough evidence to show that dispersion is uniform. Transmission Electron Microscopy (TEM) studies reveal that there is uniform deposition of silver on CNF resulting in significant improvement in interfacial adhesion with epoxy matrix. There is a considerable increase in thermal stability of the conductive nano adhesive demonstrated by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA). Four probe conductivity meters clearly shows a substantial increase in the electrical conductivity of silver coated CNF-epoxy composite compared to non-coated CNF-epoxy composite. Tensile test results clearly show that there is a significant increase in the tensile strength of silver coated CNF-composites compared to non-coated CNF-epoxy composites. Consequently, this technology is highly desirable for satellites and EMI Shielding and will open a new dimension in space research.

• The Korean Journal of Food And Nutrition
• /
• v.22 no.2
• /
• pp.215-222
• /
• 2009

The principal objective of this study was to assess the demands and satisfactions of silver welfare professionals for elderly individuals residing in the Northern Gyeonggi-do area. To this end, a survey was conducted to investigate elderly individuals and employees related with them in terms of their recognition, interest, and involvement in a labor training program. The sources of health information the subjects received included mass media(50%) and health professionals(41%), and they tended to trust the information they received from health professionals(64%) and the mass media(26%). In the case of health professionals working at silver care facilities, the sources of health information to which they had access were: mass media (51%), health professionals(20%), internet(14%), reliable health professionals(56%), mass media(22%), and books related to health(18%). Elderly subjects' reasons for satisfaction with the facilities were as follows: access to meals(32%), elderly communities(24%), and good facilities(22%), whereas the reason subjects reported dissatisfaction with social difficulties(68%), bad facilities(20%), and programs(12%). The degrees of satisfaction of the respondents with the facility's employees were reported as follows: life manager(28%), nurse(16%), and social worker(15%), whereas the subjects reported some degree of dissatisfaction with: nurses(29%), care helpers(17%), and facilities officers(13%). The priorities of the elderly welfare-related information were: disease and health(49%), daily life support(17%), nursing(11%), welfare facilities(8%), and the principal issues they reported as being relevant to elderly individuals were: palsy(16%), arthritis(14%), diabetes (12%), hypertension(10%), dementia(6%). They reported that the most important personnel for elderly in the future would be care managers(44%) and care helpers(21%). Via this developmental program of silver health care professionals, a variety of new job opportunities may be provided in the future, and a program related to the silver service industry must be established as soon as possible.

• Journal of the Korean Ceramic Society
• /
• v.41 no.4
• /
• pp.313-322
• /
• 2004

Thick film photolithography is a new technology in that the lithography process such as exposure and development is applied to the conventional thick film process including screen-printing. In this research, low-temperature cofireable silver paste, which enabled the formation of thick film fine-line using photolithographic technology, was developed. The optimum composition for fine-line forming was studied by adjusting the amounts of silver powder, polymer and monomer, and the additional amount of photoinitiator, and then the effect of processing parameter such as exposing dose on the formation of fine-line was also tested. As the result, it was found that the ratio of polymer to monomer, silver powder loading, and the amount of photoinitiator were the main factors affecting the resolution of fine-line. The developed photosensitive silver paste was printed on low-temperature cofireable green sheet, then dried, exposed, developed in aqueous process, laminated, and fired. Results showed that the thick film fine-line under 20$\mu\textrm{m}$ width could be obtained after cofiring.

• Journal of Korean Foot and Ankle Society
• /
• v.10 no.2
• /
• pp.250-254
• /
• 2006

Purpose: The treatment of diabetic foot ulcers with total contact cast has been reported to be associated with numerous undesirable complications. This study shows that our technique of total contact casting that incorporates high concentration silver coated foam dressing. Materials and Methods: Forty-four diabetic foot ulcers were treated with total contact cast along with high concentration silver coated foam dressing. Complication and healing rates were evaluated. Results: Eighty five percent of the ulcers healed within 6 weeks with an overall complication rate of 7%. There were only two cases (5%) of infection and no recurrent ulceration and no another site new pressure ulcer in our study. Conclusion: Total contact casting incorporates high concentration silver coated foam dressing resulted in fewer complications rate and healing rate that is comparable to other studies.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.5
• /
• pp.805-810
• /
• 2006

Defects in the conventional casting process of silver jewelry can result in famished products of mediocre hardness. To overcome the shortcomings of conventional methods, we proposed new press forming process, which involves applying uniaxial pressure on casting 92.5%Ag-6.5%Cu-1%Zn ring elements and shaping with a lath. We investigated Vickers hardness, density, and microstructure evolution by changing the applied uniaxial pressure. We report that our newly proposed process can increase the hardness up to 2.3 times and decrease average grain size by 50%. Our method leads to drastic mechanical property enhancements, and is thus suitable for casting tension-style jewelry.

• Journal of Korean Society of Environmental Engineers
• /
• v.32 no.10
• /
• pp.936-941
• /
• 2010

This study was conducted to investigate formaldehyde removals by silver nano-particles attached on the surface of granular activated carbon (Ag-AC) and to compare the results to those obtained with ordinary activated carbon (AC). The BET analysis showed that the overall surface area and the fraction of micropores (less than $20{\AA}$ diameter) of the Ag-AC were significantly decreased because the silver particles blocked the small pores on the surface of the Ag-AC. The formaldehyde removal capacity of the Ag-AC determined using the Freundlich isotherm was higher than that of AC. Despite the decreased BET surface area and micropore volume, the Ag-AC had the increased removal capacity for formaldehyde, presumably due to catalytic oxidation by silver nano-particles. In contrast, the adsorption intensity of the Ag-AC, estimated by 1/n in the Freundlich isotherm equation, was similar to that of the ordinary AC, indicating that the surface modification using silver nano-particles did not affect the adsorption characteristics of AC. In a column experiment, the Ag-AC also showed a longer breakthrough time than that of the AC. Simulation results using the homogeneous surface diffusion model (HSDM) were well fitted to the breakthrough curve of formaldehyde for the ordinary AC, but the predictions showed substantial deviations from the experimental data for the Ag-AC. The discrepancy was due to the catalytic oxidation of silver nano-particles that was not incorporated in the HSDM. Consequently, a new numerical model that takes the catalytic oxidation into accounts needs to be developed to predict the combined oxidation and adsorption process more accurately.

• Journal of the Korean School Mathematics Society
• /
• v.10 no.2
• /
• pp.173-185
• /
• 2007

It is the importance of Lifelong Education that is gradually more and more increased and publicly mentioned as the population of current society is aging even very rapidly. Especially the vivid activity of human being's brain is emphasized rather than before for the protection of senile dementia as people consider the sound life worth. This paper suggests mathematical education that is applicable and suitable for the emotional and cognitive level of the aged as the way of new method. I suggest the 'silver math' that may strengthen memory, thinking power and logical power of the aged, further cause the interest through games with mathematics, finally uplift the self-perception and pride. Thus, several basic elements are proposed here in this paper, that can be the foundation for the systematic and specific research of 'silver math'.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.12
• /
• pp.1022-1026
• /
• 2007

We have demonstrated new functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of silver via photo-induced diffusion in thin chalcogenide films is considered. The influence of silver on the properties of the newly formed materials is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Silver saturated chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in programmable metallization cell (PMC) devices. In this paper, we investigated electrical and optical properties of Ag-doped chalcogenide thin film on changed thickness of Ag and chalcogenide thin films, which is concerned at Ag-doping effect of PMC cell. As a result, when thickness of Ag and chalcogenide thin film was 30 nm and 50 nm respectively, device have excellent characteristics.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2007.06a
• /
• pp.24-24
• /
• 2007

We have demonstrated new functionalities of Ag doped chalcogenide glasses based on their capabilities as solid electrolytes. Formation of such amorphous systems by the introduction of silver via photo-induced diffusion in thin chalcogenide films is considered. The influence of silver on the properties of the newly formed materials is regarded in terms of diffusion kinetics and Ag saturation is related to the composition of the hosting material. Silver saturated chalcogenide glasses have been used in the formation of solid electrolyte which is the active medium in programmable metallization cell (PMC) devices. In this paper, we investigated electrical and optical properties of Ag-doped chalcogenide thin film on changed thickness of Ag and chalcogenide thin films, which is concerned at Ag-doping effect of PMC cell. As a result, when thickness of Ag and chalcogenide thin film was 30nm and 50nm respectively, device have excellent characteristics.