• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.3
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• pp.174-180
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• 1998

In this work, the properties of FRP, which is applied recently in the composite insulating materials, by thermal treatment were investigated. The specimens were epoxy glass laminates fabricated by thermal press method and had the volume content of 46[%] cutted $45^{\circ}C$ in the fiber direction and 1.0[mm] thickness. The experimental results showed that the amount of weight loss, wettability, surface potential, and surface resistivity increased up to 200[$^{\circ}C$] as a function of temperature. Usually, most degradations caused the hydrophilic to decrease the contact angle. But, in this work on thermal-degradated FRP, we can confirm the introduction of hydrophobic properties by cross-linking and the ablation of polar small-molecules rather than chain scission and oxidation. Finally, weight loss and contact angle increased. These phenomena show the existence of hydrophobic surface. With the change to the hydrophobic surface and the electrical potential and resistivity on FRP surface increased. But, the dielectric properties and tensile stength are decreased.

• International Journal of Concrete Structures and Materials
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• v.11 no.1
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• pp.99-113
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• 2017

The effects of different lightweight functional fillers on the properties of cement-based composites are investigated in this study. The fillers include fly ash cenospheres (FACs) and glass micro-spheres (GMS15 and GMS38) in various proportions. The developed composites were tested for compressive, flexural and tensile strengths at 10 and 28-day ages. The results indicated that both FACs and GMS38 are excellent candidates for producing strong lightweight composites. However, incorporation of GMS15 resulted in much lower specific strength values (only up to $13.64kPa/kg\;m^3$) due to its thinner shell thickness and lower isostatic crushing strength value (2.07 MPa). Microstructural analyses further revealed that GMS38 and GMS15 were better suited for thermal insulating applications. However, higher weight fraction of the fillers in composites leads to increased porosity which might be detrimental to their strength development.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2004.05b
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• pp.138-141
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• 2004

In this paper, we Investigated effects on impurities and water of semiconductive shield through a thermal, mechanical, and absorption experiment to estimate performance of insulating materials in power cable. Specimens had been prepared 22[kV], 154[kV] XLPE power cables and then were made of sheet form with XLPE and semiconductive shield with dimension of 0.4[mm] ~1.2[mm] of thickness from power cable. Heat capacity $({\Delta}H)$ and glass trasition temperature (Tg) of XLPE sheet were measured by DSC (Differential Scanning Calorimetry). We could know that thermal stabilities of 154[kV] are more excellent than 22[kV] from this experimental result. The strain of mechanical properties in 22[kV] and 154[kV] XLPE was 486[%], 507[%] and stress was 1.74$[kgf/mm^2]$, 1.80$[kgf/mm^2]$. The absorption contents of existing semiconductive shield were measured 710[ppm] to 1,090[ppm], and semiconductive shield of 22[kV] cable was measured 14,750[ppm] to 24,780[ppm]. We thermal and mechanical properties of 154[kV] could know more excellent than 22[kV] from this experimental result.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.7
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• pp.510-514
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• 2013

In order to prevent heat loss that occurs through the glass, low-emissivity (Low-E) coating methods with good insulating properties and high transmittance were used. InGaZnO/Ag/InGaZnO (IGZO/Ag/IGZO) multilayer thin films have been deposited on XG glass substrate by RF magnetron sputtering. Depending on the different thickness of Ag in multilayer films, the structural and optical properties of Low-E multilayer films were analyzed. By XRD analysis results, the multilayer thin films were observed to be amorphous structure regardless of Ag thickness. According to the AFM results, surface morphology of the multilayer films was observed and compared. Using UV-VIS spectroscopy, low emissivity property has been observed clearly with the transmittance of higher than 85% at visible range and lower than 30% at IR range.

• Land and Housing Review
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• v.10 no.3
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• pp.23-32
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• 2019

Vacuum Insulation Panel(VIP) has the lowest thermal conductivity among present insulations. It is composed of envelope, core material and getter. Aluminum film is usually used as the envelope of VIP, and it is important component to decide the useful life of VIP. In this research, the thermophysical properties of incombustible fiber glass core VIP were investigated with the possibility of its architectural applications. The results of this research can be summarized as follows: 1) The thermal conductivity of 20mm-thick fiber glass core VIP is resulted as 0.00177W/m·K, which means that 20mm-thick VIP can meet all the reinforced insulation guideline and it can be used in any envelope of any region in Korea. 2) As a result of the test of incombustion and gas toxicity, fiber glass core VIP was suitable for incombustible material. 3) As the test result for the long term thermal conductivity, fiber glass core VIP was found out that it would keep above 10 times insulating performance than polystyrene foam and glass fiber. 4) To meet the thermal transmittance of 0.12W/㎡K, limited-combustible insulation of expanded polystyrene foam and phenolic foam should be used respectively as thick as above 280mm and 170mm, incombustible VIP can meet the same insulation level with 20mm thickness. 5) The price competitiveness of incombustible VIP to meet the thermal transmittance of 0.12W/㎡·K was about 1,500won/㎡ higher than that of phenolic foam.

• Journal of the Society of Naval Architects of Korea
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• v.59 no.4
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• pp.207-213
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• 2022

LNG CCS which is a special type of cargo hold operated at -163℃ for transporting liquefied LNG is composed of a primary barrier, plywood, insulation panel, secondary barrier, and mastic. Currently, glass fiber is used to reinforce polyurethane foam. In this paper, we evaluated the possibility of replacing glass fiber-reinforced polyurethane foam with basalt fiber-reinforced polyurethane foam. We conducted a thermal conductivity test to confirm thermal performance at room temperature. To evaluate the mechanical properties between basalt and glass-fiber-reinforced polyurethane foam which is fiber content of 5 wt% and 10 wt%, tensile and an impact test was performed repeatedly. All of the tests were performed at room temperature and cryogenic temperature(-163℃) in consideration of the temperature gradient in the LNG CCS. As a result of the thermal conductivity test, the insulating performance of glass fiber reinforced polyurethane foam and basalt fiber reinforced polyurethane foam presented similar results. The tensile test results represent that the strength of basalt fiber-reinforced polyurethane foam is superior to glass fiber at room temperature, and there is a clear difference. However, the strength is similar to each other at cryogenic temperatures. In the impact test, the strength of PUR-B5 is the highest, but in common, the strength decreases as the weight ratio of the two fibers increases. In conclusion, basalt fiber-reinforced polyurethane foam has sufficient potential to replace glass fiber-reinforced polyurethane foam.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.12
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• pp.1063-1066
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• 2009

In this study, we fabricated pentacene organic thin film trasistors(OTFTs) which used aluminum oxide as the gate insulator. Aluminum oxide for OTFTs was deposited on glass substrate with a different deposition rate by E-beam evaporation. In case of the deposition rate of $0.1\;{\AA}$, the fabricated aluminum oxide gate insulating OTFT showed a threshold voltage of -1.36 V, an on/off current ratio of $1.9{\times}10^3$ and field effect mobility $0.023\;cm^2/V_s$.

• Electrical & Electronic Materials
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• v.8 no.4
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• pp.434-442
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• 1995

To improve dielectric and mechanical properties of insulating composite by plasma surface treatment, new plasma surface treatment process is designed with concentric and hemi-circle electrodes system. the plasma, which is generated between anode and cathode, is induced to the upper side of the electrode system and treats the surface of the insulators. The optimal surface treatment condition is that pressure : 0.5[torr], flux density : 100[gauss], discharge current : 500[mA] and treatment time : 3 minutes. The composite filled with glass cloth surface-treated by plasma shows the improvement in electric and mechanical properties, comparing non- and coupling agent treated samples.

• 한국정보디스플레이학회:학술대회논문집
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• 2008.10a
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• pp.1145-1148
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• 2008

The present status and trend of oxide phosphor thin-film development for thin-film electroluminescent (TFEL) device application are presented in this paper. Recently, several newly developed types of bendable or bendable see-through oxide TFEL lamps have been fabricated using the TFEL technology with a newly developed bendable ceramic sheet, glass sheet or sapphire sheet substrate, which has become available on the market. Stable operation at high temperatures was obtained in double-insulating-layer-type TFEL lamps fabricated with a $Zn_2Si_{0.6}Ge_{0.}4O_4$:Mn thin-film emitting layer forming on translucent or transparent bendable sheet substrates.

• Advanced Composite Materials
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• v.16 no.4
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• pp.377-384
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• 2007

'Green' composites were fabricated from poly lactic acid (PLA) and bamboo fibers by using a conventional hot pressing method. The insulating properties of the PLA-bamboo fiber 'green' composites were evaluated by determination of the thermal conductivity, which was measured using a hot-wire method. The thermal conductivity values were compared with theoretical estimations. It was demonstrated that thermal conductivity of PLA-bamboo fiber 'green' composites is smaller than that of conventional composites, such as glass fiber reinforced plastics (GFRPs) and carbon fiber reinforced plastics (CFRPs). The thermal conductivity of PLA-bamboo fiber 'green' composites was significantly influenced by their density, and was in fair agreement with theoretical predictions based on Russell's model. The PLA-bamboo fiber composites have low thermal conductivity comparable with that of woods.