• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 1997.11a
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• pp.130-137
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• 1997

Intumescent inorganic and organic coatings which dintr one from the other by the type of gas formers and the mechanisms of foam formation have been obtained and investigated. Inorganic intumescent coatings are the compositions based on water glass and mineral additives with different dispersity. Mineral additives contain adsorbed and absorbed water and carbonates which are destructed with the carbon dioxide and water evolution during the flame action on coating. The decreasing of mineral additives particle sizes under the mechanical milling with the fraction precipitation promotes the foam coke formation with less defects. Here the main structure of comparing compositions does not change. In organic coatings based on epoxy-polymers the polyammonium phosphate additive is used. It is the cabonization catalyst and the foam agent. The polyammonium phosphate of various dispersity employed is uniformly distributed on the polymeric matrix. The decreasing of the particle sizes leads to the increasing of the fire resistant properties of the intumescent coa-ting. The fire resistant analysis of the coating during more than an hour: the coating back side the temperature on plastic or wooden materials does not exceed 423K, and on metal-573K.

• Journal of Bio-Environment Control
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• v.11 no.1
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• pp.29-34
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• 2002

An experiment was conducted to evaluate shattered industrial polyurethane (PUR) and cellular glass foam (CGF) as growth medium components. Pot chrysanthemum 'Pink Pixie Time 'was cuttured in media containing various volume ratios of PUR, CGF, peatmoss, coir, and perlite. Before plant culture, pH and EC of media were determined. Container capacity (%) was low in perlite and CGF-containing media, but it increased when incorporation ratio of peatmoss or coir was increased. pH was stable between 5.0 and 6.3, but was high in coir-contaning media as compared to other media tested. EC was very high in coir-containing media. Hight at 34 days after planting was the greatest in media containing CGF, and number. of leaves was similar among treatments. Growth in PUR-containinly media was poorer than that in the other media, with some leaf edge burning. Trends in growth measured at 97 days after planting was similar to that measured at 34 days after planting.

• Resources Recycling
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• v.24 no.1
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• pp.58-65
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• 2015

Although Korea is a top market sharing and world leading producer and developer of flat panel display devices, relevant recycling technology is not up to her prestigious status. Besides, most of the waste glass arising from flat panel displays is currently land-filled. The present paper mainly reviews on development of recycling systems for waste TFT-LCD glass from end-of-life LCD TVs and monitors and TFT-LCD process waste of crushed glass particles with target end uses of raw material for high strength concrete pile and glass fibers, respectively. Waste LCD glass was recycled to fabricate ingredients for high strength concrete piles with enhanced physical properties and spherical foam products. The waste LCD glass recycling technology is already developed to fabricate long and short fibers at commercial level. In view of these, future R & D on waste LCD glass materials is to be directed toward implementation of commercial materials recycling system therefrom.

• Journal of Bio-Environment Control
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• v.11 no.3
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• pp.108-114
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• 2002

Cellular glass foam (CGE), the reprocessed glass, has a possibility as a component of vegetative propagation media of floricultural crops due to the its excellent air and water permeability, similar to that of perlite. An experiment was conducted to evaluate the rooting and growth thereafter of Kalanchoe blossfeldiana ‘Gold Strike’in media containing various volume ratios of granular rockwool, peat-moss, CGF and perlite. The particle size of CGF and perlite was 2.0~4.0mm and 1.2~4.0mm, respectively. Cuttings were rooted in a fog tunnel with a mean temperature of 18.2$^{\circ}C$ and RH of 66.7％ under a long day regime (14 h per day light period). Height, length of the longest root, stem diameter, no. of leaves, leaf area, percentage of rooted cuttings, shoot and root fresh weights, shoot and root dry weights, total chlorophyll concentration and physicochemical properties were measured. Cuttings rooted 100% in all treatments. Physicochemical properties in CGF and perlite-containing media showed little differences. The growth of rooted plants in the CGF-containing media was similar or rather superior to that in perlite-containing media. Consequently, CGF has a possibility as a vegetative propagation medium of Kalanchoe. To make wider commercial use of CGF, more demonstrative experiments and analyses are necessary.

• Structural Engineering and Mechanics
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• v.41 no.2
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• pp.231-242
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• 2012

This research work aims to develop an optimal design using Finite Element (FE) and Genetic Algorithm (GA) methods to replace the traditional concrete and timber material by a Synthetic Polyurethane fibre glass composite material in railway sleepers. The conventional timber railway sleeper technology is associated with several technical problems related to its durability and ability to resist cutting and abrading action of the bearing plate. The use of pre-stress concrete sleeper in railway industry has many disadvantages related to the concrete material behaviour to resist dynamic stress that may lead to a significant mechanical damage with feasible fissures and cracks. Scientific researchers have recently developed a new composite material such as Glass Fibre Reinforced Polyurethane (GFRP) foam to replace the conventional one. The mechanical properties of these materials are reliable enough to help solving structural problems such as durability, light weight, long life span (50-60 years), less water absorption, provide electric insulation, excellent resistance of fatigue and ability to recycle. This paper suggests appropriate sleeper design to reduce the volume of the material. The design optimization shows that the sleeper length is more sensitive to the loading type than the other parameters.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.22 no.3
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• pp.414-420
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• 2013

Research on decreasing the weight of composite sandwich panels is in progress. This paper reports the experimental results for the mechanical behavior of a composite sandwich panel. The skins of sandwich panels were made of glass fiber sheets and plywood matrix composites. Their interior layers consisted of glass fiber pultrusion pipes and gold foam. Experimental tests were performed to obtain the mechanical properties and complex mechanical behavior. Before fatigue tests, tensile tests and 3-point bending tests were carried out to obtain the optimal design and determine their strength and failure mechanisms in the flat-wise position. After the static test, a fatigue test were conducted at a load frequency of 5 Hz, stress ratio (R) of 0.1, and endurance limit for the S-N curve. It showed that the failure modes were related to both the core design and skin failure.

• Korean Journal of Materials Research
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• v.12 no.6
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• pp.458-463
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• 2002

Carbon nanotubes were synthesized at various conditions using Ni-catalytic thermal chemical vapor deposition method and their characteristic properties were investigated by SEM, TEM and Raman spectroscopy. Carbon nanotubes were formed on very fine Ni-catalytic particles. The carbon nanotubes synthesized by thermal decomposition of acetylene at $700^{\circ}C$ had a coiled shape, while those synthesized at $850^{\circ}C$ showed a curved and Y-shape having a bamboo-like morphology. It was found that the carbon nanotube was also made on the fine Ni-catalytic particles formed on the surface of 100~400nm sized large ones after pretreatment with $NH_3$.ber composites show the high dielectric constant and large conduction loss which is increased with anisotropy of fiber arrangement. It is, therefore, proposed that the glass and carbon fiber composites can be used as the impedance transformer (surface layer) and microwave reflector, respectively. By inserting the foam core or honeycomb core (which can be treated as an air layer) between glass and carbon fiber composites, microwave absorption above 10 dB (90% absorbance) in 4-12 GHz can be obtained. The proposed fiber composites laminates with sandwitch structure have high potential as lightweight and high strength microwave absorbers.

• Journal of the Society of Naval Architects of Korea
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• v.30 no.1
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• pp.134-144
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• 1993

Sandwich plate is consisted of equal two isotropic, thin, stiff and strong sheets of dense material separated symmetrically by an isotropic thick layer which may be much less stiff and strong. This study analyzed the dependency of the natural frequencies and mode shapes of sandwich plates on material properties, thicknesses of faces and cores, and various boundary conditions using Rayleigh-Ritz method. E-glass Woven Roving and another two kinds of materials were selected as a face, P.V.C. and another kinds of materials were selected as a core. Natural frequencies and mode shapes obtained by Rayleigh-Ritz method were compared with F.E.M. solutions using ADINA program.

• Proceedings of the KSME Conference
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• 2003.11a
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• pp.1280-1285
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• 2003

In the developement of LNG cargo, the current concern focuses on the slim design of insulation layer to increase the LNG carrying capacity. Not only thermal stability with BOR(Boil-Off Rate) but structual stability against the LNG weight and the sloshing phenomenon must be also considered. In this paper, we applied the stitched sandwitch composite called the 3X-Board which is stitched through the core thickness direction using glass fiber to the LNG cargo. We evaluated the thermal and structural characteristics of 3X-Board by changing the core thickness and the material, in order to explore a validity for the slim design through the finite element analysis.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.422-422
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• 2009

This paper describes the structural design of small wind turbine blade by using design of experiments. Blade structure consists of skin, spar and foam. The materials for skin and spar are a kind of Glass/Epoxy and form is polyurethane. It has 7 lay-ups with different ply angle. A factorial design is applied to design the ply angles considering manufacturing constraints and to investigate the safety factor which is calculated by structural analysis. In order to perform the structural analysis, the commercial software ABAQUS is used. Tsai-Wu failure criterion is chosen to compute safety factor. The determination of the significance of effects in the experiments is made through the analysis of variance. The results show that ply angle at skin affects the safety factor of wind turbine blade. And from this result, optimal ply angles of composite blade are achieved.