• Journal of the Korea Convergence Society
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• v.9 no.12
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• pp.99-106
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• 2018

The modifier proposed in this research is for enhancing the affinity of the glass component with the high polymer resin and the molecular weight. The particle packing, tensile strength and shielding performance of the shielding sheet made of the tungsten oxide were evaluated. The best effect can be obtained when 20% of the modifier PMMA used to improve the shielding performance and maintain the affinity and strength with the sealant is mixed. The fusion of the materials presented in this study and the mass production of the shielding sheet through the modifier are possible and will contribute to the production of lightweight shielding sheets in the future.

• Journal of Environmental Science International
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• v.28 no.6
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• pp.553-559
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• 2019

In this study, zeolitic materials at $Na_2CO_3/CFA$ ratio of 0.6 - 1.8 were synthesized from coal fly ash from a thermal power plant using a fusion/hydrothermal method. The zeolitic materials were found to have cubic crystals structure and X-ray diffraction (XRD) peaks of Na-A zeolite by XRD and SEM analysis. When the zeolitic materials were synthesized from the coal fly ash, the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratios of 0.9-1.8 had the same location as the XRD peaks of commercial Na-A zeolite. The XRD peaks of the Na-A zeolite ($Na_{12}Al_{12}Si_{12}O_{48}27.4H_2O$) were confirmed in the $2{\theta}$ in the range of 7.18-34.18. However, it was also confirmed that peaks of $CaCO_3$, an impurity inhibiting synthesis of Na-A zeolite from CaO and $Na_2CO_3$ in the coal fly ash, occurred in the XRD peaks of the zeolitic materials at $Na_2CO_3/CFA$ ratio of 1.5-1.8. The crystallinities of the zeolitic materials tended to increase gradually within the $Na_2CO_3/CFA$ ratio range of 0.6-1.8.

• Journal of the Microelectronics and Packaging Society
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• v.25 no.4
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• pp.25-34
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• 2018

In this paper, we review the latest technical progress and commercialization of stretchable interconnectors, stretchable strain sensors, and stretchable substrates for stretchable electronics. The development of stretchable electronics can pave a way for new applications such as wearable devices, bio-integrated devices, healthcare and monitoring, and soft robotics. The essential components of stretchable electronic devices are stretchable interconnector and stretchable substrate. Stretchable interconnector should have high stretchability and high electrical conductivity as well as stability under severe mechanical deformation. Therefore several nanocomposite-based materials using CNT, graphene, nanowire, and metal flake have been developed. Geometric engineering such as wavy, serpentine, buckled and mesh structure has been well developed. Stretchable substrate should also pose high stretchability and compatibility with stretchable sensing or interconnecting material. We summarize the recent research results of new materials for stretchable interconnector and substrate as well as strain sensors. The Important challenges in development of the stretchable interconnector and substrate are also briefly discussed.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2014.05a
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• pp.150-151
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• 2014

A mold of free-form concrete segment can be used only one time. Thus, the construction duration and cost are increased. The materials of the mold such as wood and metal have limitations due to the implementation and reuse. The review of the material of the mold for free-form concrete segment is needed to reduce duration and production cost. Phase change material can be used both to implement free-shape by heating and to produce mold after cooling. After using Phase change material can be re-used to mold by heating. The scope of this study is many kind of phase change materials for molding. The aim of this study is to analyze the phase change materials for production of changable mold for free-form concrete segment. In this study, the paraffin wax that is melted at 64℃ was selected by considering both the energy efficiency and the weather of Korea.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.6
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• pp.518-525
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• 2006

The present experiments have been performed for obtaining the melting heat transfer characteristics of micro-encapsulated solid-liquid phase-change material and water mixture slurry flow in a circular tube heated with constant wall heat flux. The phase change material having a low melting point was selected for a domestic cooling system in the present study. The governing parameters were found to be latent heat material concentration, heat flux, and the slurry velocity. The experimental results revealed that the increase of tube wall temperature of latent microcapsule slurry was lower than that of water caused by the heat absorption of fusion.

• Journal of Welding and Joining
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• v.31 no.5
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• pp.41-46
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• 2013

Different microstructures in the weld zone of a metal structure such as a fusion zone or heat affected zone are formed as compared to the parent material. Thus, the mechanical properties in the weld zone are different from those in the parent material. As the basic data for reliably understanding the structural characteristics of a welded PCHE specimen to be made of Alloy 617, the mechanical properties in the weld zone and parent material for a Alloy 617 plate are measured using an instrumented indentation technique in this study.

• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.193-198
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• 2005

The present experiments have been performed for obtaining the melting heat transfer characteristics of micro-encapsulated solid-liquid phase change material and water mixed slurry flow in a circular tube heated with constant wall heat flux. The phase change material having a low melting point was selected for a domestic cooling system in the present study. The governing parameters were found to be latent heat material concentration, heat flux, and the slurry velocity. The experimental results revealed that the increase of tube wall temperature of latent microcapsule slurry was lower than that of water caused by the heat absorption of fusion.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.33B no.4
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• pp.41-51
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• 1996

This paper presents a fuzzy data fusion scheme which can analyze the sensor condition, the strength and location of a force applied to a test material. These can be realized by the modelling and fusioning of sensor signals and sensor properties. The technique uses, as the inference variables, relative magnitude of data (RMD), absolute magnitude of data (AMD) initial state (IS), synchronized relational function (SRF) and asynchronized relational function (ARF). To show the usefulness of this scheme, an experiment on the cantilever bar and six strain gages is carried out. The location of the force is inferred from SRF and ARF and the strength from RMD and AMD. In particular, the strength is compared with the measurement data of the force sensor.

• Journal of Welding and Joining
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• v.18 no.3
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• pp.76-82
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• 2000

In this study, three-dimensional heat flow in laser beam welding for deep penetration was analyzed by using F.E.M common code, and then the results were compared with the experimental data. The models for analysis are full penetration welds and are made at three different laser powers (6, 9.9, 4.5 kW) with two different welding speeds (5.8mm/s, 5mm/s). The characteristics of thermal absorption by the workpiece during deep penetration laser welding can be represented by a combination of line heat source through the workpiece and distributed heat source at the top surface due to the plasma plume above the top surface. This gives an insight into the way in which the beam interacts with the material being welded. The analyses performed with the combined heat source models show comparatively good agreement between the experimental and calculated melt temperature isotherm, i.e, the fusion zone boundary. The results are used to explain the "nail head" appearance of fusion zone, which is quite common in laser beam welds.eam welds.

• Journal of Environmental Science International
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• v.26 no.2
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• pp.239-248
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• 2017

Green synthesis of gold nanoparticles(GNPs) considered more ecofriendly and cost effective than other chemical methods use of dangerous reagents and solvents, improved material and energy efficiency and enhanced design of non-toxic products. In this study, we developed a green synthesis method for using Caulis in Taeniam (BCT). BCT were characterized by UV-vis, Zetasizer, TEM, XRD, and FTIR. The antioxidant activity of BCT was determined by DPPH and ABTS radical-scavenging assays, and heme oxygenase-1 induction in RAW 264.7 macrophages. The resulting BCT appeared spherical with an average diameter of 67.171.39 nm The aAntioxidant activity was increased in a dependent manner. To conclude, the green synthesis of BCT-GNPs was successful, and it appers to be useful in the for future applications.