• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.618-621
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• 2006

This paper is to investigate temperature history of cold weather concrete depending on insulation curing sheet kinds. Insulating effect according to curing sheet is shown in order of 5 layer bubble sheet, combination of PE form and 3 layer bubble sheet and 3 layer bubble sheet. It maintained above $10^{\circ}C$ of minimum temperature until the completion of initial curing period when bubble curing sheet was supplied regardless of curing sheet kinds. Five layer bubble curing sheet secure higher curing temperature than any other curing sheet applied in this experiment by as much as $2{\sim}3^{\circ}C$, which performed remarkable insulation effect. Concrete applied with curing sheet secured above $65^{\circ}D{\cdot}D$ of maturity, at which concrete had 5MPa of compressive strength at 3 days.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.53 no.6
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• pp.312-315
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• 2004

The monolayer of oxygen atoms sandwiched between the adjacent nanocrystalline silicon layers was formed by ultra high vacuum-chemical vapor deposition (UHV-CVD). This multilayer Si-O structure forms a new type of superlattice, semiconductor-atomic superlattice (SAS). According to the experimental results, high-resolution cross-sectional transmission electron microscopy (HRTEM) shows epitaxial system. Also, the current-voltage (Ⅰ-Ⅴ) measurement results show the stable and good insulating behavior with high breakdown voltage. It is apparent that the system may form an epitaxially grown insulating layer as possible replacement of silicon-on-insulator (SOI), a scheme investigated as future generation of high efficient and high density CMOS on SOI.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.52-56
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• 2001

Experiments of 2 type on insulating compounds accomplished to change PVC using in URD(Underground) power cable jacketing. one was DB(Dielectric Breakdown) test on the pure base resins and the others were WVT(Water Vapor Transmission) test on the compounds which contained C/B(Carbon Black), anti-oxidant to base resin. a kind of specimens made by pressing to resin of pellet or lump form was HDPE(High Density Polyethylene), MDPE(Medium Density Polyehylene), LDPE(Low Density Polyethylene), LLDPE(Linear Low Density Polyethylene), PVC(Polyvinyl Chloride). As a results of AC DB and WVT test, we saw that strength of Insulation was HDPE> LLDPE = MDP E> LDPE and WVT ratio was HDPE

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.232-233
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• 2005

The Surface of semi-conductive silicone rubber was treated by oxygen plasma to improve adhesion and electric performance in joints between insulating and semi-conductive silicone materials. Surface characterizations were assessed using contact angle measurement and Fourier transform infrared spectroscope (FTIR). Adhesion level was understood from T-peel tests between plasma treated semi-conductive and insulating material. Electrical breakdown strength was measured to understand the charge of electrical performance. From the results, the oxygen plasma treatment produces a significant increase in function group of containing oxygen which can be mainly ascribed to the creation of carbonyl groups on the silicone surface from the strength were improved. Therefore it is concluded then plasma treatment leads to decrease voids originating form poor adhesive, and the improve the adhesion in silicone interface. So we could obtain higher electrical design level of silicone material used for electrical apparatus using oxygen plasma treatment.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.63-67
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• 1990

Many characteristics of space charge in insulating materials which is the cause of insulation break down was measured quantita-tively. It was confirmed that injection charge of the electrode was trapped to form mainly space charge. In the present paper, collecting potential was determined by TSSP and mean depths of space distribution was investigated by measuring variation quantity of space charge under the different bias time, voltage and temperature. Experimental resuts was in good agreement with model analysis on a stedy state.

• Journal of the Korean Ceramic Society
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• v.27 no.7
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• pp.891-898
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• 1990

This study deals with the porous sintered body which is obtained by blending solid naphthalene with fine particles of Hwasun flint clay. Apparent porosity is increased, and bulk density, thermal conductivity, strength and thermal expansion are decreased according to the additiion of naphthalene. Pore shape of sintered body showed elliptical form and median size and capilary percentage are increased by adding more naphthalene.

• KIEAE Journal
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• v.7 no.1
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• pp.95-100
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• 2007

In apartment houses, said to be similar to a typical housing form, every household share the walls and floors. Many problems inevitably accompany such as an arrangement, as noise and vibration are shared among households. When investigating the percentage of apartment resident's dissatisfaction with housing environments, discontent due to noise ranks the highest. Among many different kinds of noises, noise such as floor crashing sounds show the highest indication rate in the residents' comparison of discontent. Therefore, it is the practice of insulating against noises such as floor crashing sounds that improves the apartment house environments. The factors influencing the floor impact sound insulation include floor finishing materials, shock absorbing floors (slabs included), and ceiling structures. The ceilings of the apartment houses, currently built in Korea, are set up with lower parts of slabs and paper finishing, or with double floors for protecting against floor impact sounds in order to improve the sound insulating performance. The most common the method of ceiling structure construction consists of 'wood boarded frames +Gypsum boards + ceiling papers', which is called the wood boarded frame method. This study aimed to measures and evaluates floor impact sound insulation by which the ceiling space are widened according to suppression system is added in apartment house ceiling structure.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.52-56
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• 2001

Experiments of 2 type on insulating compounds accomplished to change PVC using in URD(Underground) power cable jacketing. one was DB (Dielectric Breakdown) test on the pure base resins and the others were WVT(Water Vapor Transmission) test on the compounds which contained C/B(Carbon Black), anti-oxidant to base resin. a kind of specimens made by pressing to resin of pellet or lump form was HDPE(High Density Polyethylene), MDPE(Medium Density Polyehylene), LDPE(Low Density Polyethylene), LLDPE(Linear Low Density Polyethylene), PVC (Polyvinyl Chloride). As a results of AC DB and WVT test, we saw that strength of Insulation was HDPE > LLDPE ≒ MDPE > LDPE and WVT ratio was HDPE < LLDPE < MDPE < LLDPE ≒ LDPE${\ll}$PVC. WVT of PVC using for jacket showed characteristic 15 times more than MDPE or LLDPE. Therefore, to development of watertightness cable, our works present need of Changing in insulating materials

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.11a
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• pp.37-38
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• 2017

In Infrared rays, which are 50% of sunlight, act as heat rays to heat buildings. Solar heat paint is widely used to protect buildings from sunlight. Solar heat coatings are used to block buildings form sunlight. Solar heat paints are classified as heat-reflective paints and heat-insulating paints according to the differential thermal mechanism. In this study, we study the thermal differential mechanism by analyzing the temperature change of the coated steel plate and the solar reflection spectrum on the surface. In this experiment, exposed steel plate, heat-reflective coated steel plate, heat-insulating coated steel plate, and general paint coated steel plate were used. As a result, when the infrared rays of 780nm ~ 1400nm were irradiated, the heat reflective paint had a temperature lower by 10 degrees than other paints. Analysis of the reflection spectrum of the paint shows that the heat paint is lower in heat than other paints because it has higher reflectance of light and absorbs much of the infrared rays.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.11a
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• pp.180-183
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• 2003

The monolayer of oxygen atoms sandwitched between the adjacent nanocrystalline silicon layers was formed by ultra high vacuum-chemical vapor deposition (UHV-CVD). This multi-layer Si-O structure forms a new type of superlattice, semiconductor-atomic superattice (SAS). According to the experimental results, high-resolution cross-sectional transmission electron microscopy (HRTEM) shows epitaxial system. Also, the current-voltage (I-V) measurement results show the stable and good insulating behavior with high breakdown voltage. It is apparent that the system may form an epitaxially grown insulating layer as possible replacement of silicon-on-insulator (SOI), a scheme investigated as future generation of high efficient and high density CMOS on SOI.