• Journal of Bio-Environment Control
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• v.21 no.4
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• pp.336-342
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• 2012

Inorganic materials were commonly used as container media in domestic plant factories. Objective of this research was to secure the information in soil physical and chemical properties of inorganic materials such as vermiculites and perlites. To achieve this, 12 gold and silver vermiculites from China, Zimbabwe, and South Africa and 5 perlites from China were collected based on the marketing grades (MG) in particle sizes and analyzed for determination of their characteristics. The percentage of particles larger than $710{\mu}m$, in China perlite MG 3~5 mm, China silver vermiculites MG > 8 mm and MG 3~8 mm were 99.9%, 99.8%, and 99.7%, respectively, which were much higher than 28.4% in China gold vermiculite MG 0.3~1.0 mm, 14.0% in perlite MG < 1.0 mm, and 12.6% of Zimbabwe silver vermiculite MG < 1.0 mm. The container capacities of perlite MG < 1.0 mm and South Africa silver vermiculite MG 0.25~1.0 mm were 72.0% and 71.1%, respectively. The air space in China silver vermiculite MG 3~8 mm was 49.3% which was higher than other materials tested. However, the China gold and silver vermiculites MG 0.3~1 mm had 3.5% and 2.4% in air space indicating that possible problems could occur in soil aeration when they are used for container media. The percentage of easily available and buffering water of China gold vermiculite MG 0.3~1 mm and perlite MG < 1.0 mm were the highest among test materials. The ranges of pH and electrical conductivity were 6.36 to 10.7 and 0.032 to $0.393dS{\cdot}m^{-1}$ in vermiculites and 7.78 to 8.62 and 0.030 to $0.041dS{\cdot}m^{-1}$ in perlite, respectively. The cation exchange capacity of China silver vermiculite MG 0.3~1 mm were $14.7cmol{\cdot}kg^{-1}$ that was 10 times as high as $0.34cmol{\cdot}kg^{-1}$ in perlite MG 1~2.5 mm. The vermiculites had the higher contents of exchangeable cations such as Ca, K, and Na, than those of perlites.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.3
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• pp.93-97
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• 2015

To synthesis of high purity micro silver particle, we extracted the silver from the waste by liquid-liquid extraction and used the rapid firing-liquid phase precursor (RF-LPP) method. The silver micro particle was synthesized at $500^{\circ}C$ for 3 hr in air atmosphere by RF-LPP method. As a result of the research, micro silver particle is measured X-ray diffraction (XRD), the main peak is nearly corresponded to the same as JCPDS card (No.87-0719). With using the RF-LPP method, the fine Ag micro particle indicated due to the control of nucleation site and the oxygen contents was decreased by reducing treatment. We expect this research contribute to advance in field of the recycling technology.

• Journal of Veterinary Clinics
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• v.28 no.6
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• pp.576-580
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• 2011

Silver has potent antibacterial activity against a variety of bacteria while maintaining low toxicity in mammalian cells. This study was conducted to investigate the possible mechanism underlying the bactericidal effects of silver ions against bovine mastitis pathogens using electron microscopy. We used two different bacterial strains, Escherichia coli and Staphylococcus aureus, which are primarily responsible for the majority of bovine mastitis cases. Interaction between the bacteria and silver ions (50 ${\mu}g/mL$, 2 hours) were studied using energy-filtering transmission electron microscopy (EFTEM). EFTEM images showed that E. coli and S. aureus cells treated with the silver ions had distorted plasma membranes, silver ions attached to the outer membranes, scattered electron-light material, and leakage of cell contents from disrupted cell membranes.

• Proceedings of the Korea Contents Association Conference
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• 2014.11a
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• pp.137-138
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• 2014

노인은 대부분의 활동을 주거 공간 중심으로 보내게 되므로, 노화에 따른 만성적 지병과 신체활동의 기능저하로 말미암아 주거와 의료 서비스의 결합은 노인의 생활에 있어서 핵심적인 요소가 아닐 수 없다. 따라서 주거와 의료서비스를 결합한 노인의료주거단지에 있어 노인의 라이프스타일을 반영한 다양한 형태의 주거생활공간에 대한 연구와 대안모색이 필요하다. 참여와 공동창작으로 이루어지는 유니버설서비스디자인의 프로세스를 본 연구에 도입함으로써 주체적이고 활동적인 서비스의 소비자로서의 노인에 대한 적극적인 대안이 될 것이다.

• Proceedings of the Korea Contents Association Conference
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• 2017.05a
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• pp.459-460
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• 2017

The research proposes theoretical recommendations for Smart City that targets elderly citizens. The elderly citizens in question are people currently in their mid-50s to early 60s, in order to adequately employ futuristic technologies into four major sectors: healthcare, post-retirement employment, community-based governance, and environment-friendly infrastructure. The research concludes that the technical application of welfare to the elderlies through constructing a purposeful Smart City is desirable, environmental consideration should come in prior concern as a sustainable foundation.

• Journal of the Korean School Mathematics Society
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• v.13 no.3
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• pp.459-483
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• 2010

This study aims to develop materials related to math education for the aged and to identify the effects of application as part of active measures to the aging society with its growing elderly population which is one of the greatest changes in our society. In this purpose, the necessity and objectives for development of materials of 'Silver Math' as education for the aged are explained. Developing and disseminating materials with a role as a program for intelligent needs and physical and spiritual health of the aged presents standards for development of more systemic and meaningful educational materials at this point of time when the importance of education of the aged increases to help the old enjoy qualitatively successful lives in later years in the perspective of lifelong education. Also it aims to present standards of contents and requirements in learning that are adequate and meaningful to old learners at the actual learning sites where education takes place only in terms of making good use of spare time while at the same time suggesting plans of teaching and learning as well as conditions for learning environment. Next, the effectiveness of 'Silver Math' are explored by applying developed materials to the aged. materials of 'Silver Math' for the aged with contents that are appropriate to the definitive and cognitive level of the aged are presented. The developed materials for mathematical activities are divided into 'computation of basic numbers' for those wishing to learn calculation and concepts of numbers, 'active math' that corresponds to definitive factors of old learners, facilitates leisure time through mathematical activities, and Improves communication abilities through cooperative learning among learners, and 'math with thinking power' to solve simple calculation problems by applying to various actual situations.

• Proceedings of the Zoological Society Korea Conference
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• 2000.10a
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• pp.145.1-145
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• 2000

No Abstract, See Full Text

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

• Journal of the Korean Ceramic Society
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• v.44 no.4 s.299
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• pp.208-213
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• 2007

Alumina/silver ($Al_2O_3/Ag$) nanocomposites with Ag content up to 9 vol% were prepared from nanopowder by soaking method using ${\gamma}-Al_2O_3$ of needle type and spark plasma sintering (SPS). The mechanical properties of specimens were investigated three-point flexural strength and toughness as a function of the Ag contents. The maximum flexural strength of the alumina/silver nanocomposite was 850 MPa for the 1 vol% composite, and also higher than monolith alumina as about 800 MPa at 3, 5, and 7 vol% Ag contents. Fracture toughness by single edged V-notch beam (SEVNB) was $4.05MPa{\cdot}m^{1/2}$ for the 3 vol% composite and maintained about $4.00MPa{\cdot}m^{1/2}$ at 5, and 7 vol% Ag content. Microstructure of fracture surface for each fracture specimens was observed. Due to the inhibition effect of alumina grain growth, the average grain size of nanocomposites depends on the content of Ag nano particles. The fracture morphology of nanocomposite with dislocation (sub-grain boundary) by silver nano-particles of second phases in the alumina matrix also showed transgranular fracture-mode compare with intergranular of monolith alumina. Thermal conductivity of specimens at room temperature was about 40 W/mK for the 1 vol% Ag content.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.46 no.2
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• pp.8-15
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• 2014

A novel antibacterial paper coated with chitosan-based silver (Ag) nanocomposite prepared by green synthesis has been investigated for a wide range of application in food, agricultural and medical packaging. Green synthesis of Ag nanoparticles (AgNPs) was carried out by a chemical reaction involving a mixture of chitosan-silver nitrate (AgNO3) in an autoclave at 15 psi, $121^{\circ}C$, for 15-120 sec. AgNPs and their formation in chitosan were confirmed by both UV-Vis spectroscopy and transmission electron microscope (TEM). Fourier transform infrared spectroscopy (FTIR) study showed that free amino groups in chitosan act as an effective reductant and AgNPs stabilizer. Antibacterial test of coated paper with as-prepared chitosan-AgNPs was performed qualitatively against E. coli based on the formation of halo zones around coated papers and it was shown to be effective in suppressing the growth of E. coli with increasing Ag contents in coating layer.