• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2008.11a
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• pp.6-7
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• 2008

Composite nanoparticles of silica-polyaniline were synthesized and tested as an electrochromic material. For the optical application, the size of the nanoparticle was intended to be less than 100 nm in diameter. The synthesis was done by using a microemulsion synthesis method where the silica-polyaniline composite nanoparticle was obtained by dispersing two acidic aqueous phases containing aniline and polymerization agent, respectively. Microstructure analysis such as TEM and BET surface area measurement showed the possibility that polyaniline is incorporated in porous silica structure. The composite structure of the particle was proved to enhance chemical stability of the prepared electrochromic film.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.366-367
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• 2006

Carbon nanotubes (CNTs) have attracted remarkable attention as reinforcement for composites owing to their outstanding mechanical properties. The CNT/Cu nanocomposite is fabricated by a novel fabrication process named molecular level process. The novel process for fabricating CNT/Cu composite powders involves suspending CNTs in a solvent by surface functionalization, mixing Cu ions with CNT suspension, drying, calcination and reduction. The molecular level process produces CNT/Cu composite powders whereby the CNTs are homogeneously implanted within Cu powders. The mechanical properties of CNT/Cu nanocomposite, consolidated by spark plasma sintering of CNT/Cu composite powders, shows about 3 times higher strength and 2 times higher Young's modulus than those of Cu matrix.

• Nuclear Engineering and Technology
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• v.52 no.5
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• pp.1093-1097
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• 2020

A composite iodine sorbent was obtained in the form of porous polymer matrix with activated carbon particles impregnated with triethylenediamine deposited on its surface. A comparative assessment of the radioactive methyliodide capturing efficiency by the composite sorbent and a sample of industrial charcoal sorbent was conducted. It was shown that under the selected testing conditions, the hydraulic resistance of the composite sorbent is lower, and the sorption capacity is higher than that of the industrial charcoal sorbent. A method for comparing the effectiveness of iodine sorbents, based on the calculation of the ratio of the sorption capacity index to the minimum capacity index, needed for the required purification degree was proposed.

• Steel and Composite Structures
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• v.31 no.2
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• pp.125-131
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• 2019

This paper presents the results of an experimental study to investigate the mechanical behavior of partially encased composite columns confined by CFRP under axial compression. The results show that the failure of the partially encased composite columns confined by CFRP occurred due to rupture of the CFRP followed by local buckling of the steel flanges. External wrapping of CFRP effectively delayed the local buckling of the steel flanges. The load carrying capacity of the column increased with the application of CFRP sheet. And the enhancement effect of the column was increased with the number of CFRP layer.

• Elastomers and Composites
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• v.57 no.4
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• pp.129-137
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• 2022

Low molecular weight liquid butadiene rubber (LqBR) is a processing aid that can resolve the migration problem of tire tread compounds. Various studies are being conducted to replace the petroleum-based processing oil with LqBR. However, the effect of the loading time of LqBR in the compounding process on silica dispersion and vulcanizate properties is not well known. In this study, we analyzed silica dispersion, vulcanizate properties, and viscoelastic properties of silica-filled tire tread compound according to the processing aid type (TDAE oil, non-functional LqBR) and, silane terminated LqBR) and input timing. In the non-functional LqBR compounds, the 'with TESPT' mixing procedure showed excellent dynamic viscoelastic properties while silane-terminated LqBR compounds showed that the 'after TESPT' mixing procedure was good for 300% modulus and abrasion resistance.

• Earthquakes and Structures
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• v.23 no.5
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• pp.445-462
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• 2022

To investigate and evaluate the seismic damage behaviors of steel reinforced recycled concrete (SRRC) filled circular steel tube composite columns, in this study, the cyclic loading tests of 11 composite columns was carried out by using the load-displacement joint control method. The seismic damage process, hysteretic curves and performance indexes of composite columns were observed and obtained. The effects of replacement rates of recycled coarse aggregate (RCA), diameter thickness ratio, axial compression ratio, profile steel ratio and section form of profile steel on the seismic damage behaviors of composite columns were also analyzed in detail. The results show that the failure model of columns is a typical bending failure under the combined action of horizontal loads and vertical loads, and the columns have good energy dissipation capacity and ductility. In addition, the replacement rates of RCA have a certain adverse effect on the seismic bearing capacity, energy consumption and ductility of columns. The seismic damage characteristics of composite columns are revealed according to the failure modes and hysteretic curves. A modified Park-Ang seismic damage model based on the maximum displacement and cumulative energy consumption was proposed, which can consider the adverse effect of RAC on the seismic damage of columns. On this basis, the performance levels of composite columns are divided into five categories, The interlayer displacement angle and damage index are used as the damage quantitative indicators of composite columns, and the displacement angle limits of composite columns at different performance levels under 80% assurance rate are calculated as 1/105, 1/85, 1/65, 1/28, and 1/25 respectively. On this basis, the damage index limits corresponding to each performance level are calculated as 0.045, 0.1, 0.48, 0.8, and 1.0 respectively. Finally, the corresponding relations among the performance levels, damage degrees, interlayer displacement angles and damage indexes of composite columns are established. The conclusions can provide reference for the seismic design of SRRC filled circular steel tube composite columns, it fills the vacancy in the research on seismic damage of steel reinforced recycled concrete (SRRC) filled circular steel tube composite columns.

• The magazine of the Korean Society for Advanced Composite Structures
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• v.1 no.1
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• pp.56-61
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• 2010

• Polymer Science and Technology
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• v.10 no.1
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• pp.20-34
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• 1999

• Journal of Korea Technology Innovation Society
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• v.8 no.2
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• pp.583-604
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• 2005

The future will see all industries become technology-driven in the competitive global market place. Firms with deep technological roots and innovation strategies have some advantages. In this situation widely used scoring approach is not enough to evaluate technology's relative competitiveness and to assign relative ranking category. Therefore, a more useful and comprehensive approach, which is called technology composite index, is needed to complement and enhance the existing scoring approach. In this research, factor analysis is applied to determine the common factors and to estimate associated weights. And technology composite index is used to measure the technology's relative strength and also to assign its ranking category instead of technology scoring.

• Bulletin of the Korean Chemical Society
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• v.29 no.1
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• pp.29-30
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• 2008