• Journal of the Korea Institute of Building Construction
• /
• v.11 no.6
• /
• pp.634-644
• /
• 2011

Recently, As a part of urban forestation, the introductions of green roofs into public projects has been actively driven. Supported by this policy, the sizes of domestic green roof related markets have been rapidly expanding and many types of root barrier materials developed in Korea or abroad are being commercially distributed. In this study, root barrier tests were conducted over two years with nine types of sheet type waterproof materials that are the most commonly used as root barrier layers in green roof systems. The test conditions prepared considered the climates, natural features and vegetation in Korea and the results and related root barrier performance were verified. From the results of this study, the necessity to improve the joint part of root barrier sheets and forming methods has been identified and a measure to improve domestic root barrier testing methods was proposed.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.20 no.2
• /
• pp.118-123
• /
• 2007

The purpose of this work was to investigate the design and fabrication process effects on electrical properties in high capacitance multilayer ceramic capacitor (MLCC) with nickel electrode. Dielectric breakdown voltage and insulation resistance value were decreased with increasing stack layer number, but dielectric constant and capacitance were increased. With increasing green sheet thickness, dielectric breakdown voltage, C-V and I-V properties were also increased. The major reasons of the effects were thought to be the defects generated extrinsically during fabrication process and interfacial reactions formed between nickel electrode and dielectric layer. These investigations clearly showed the influence of both green sheet thick ness and stack layer number on the electrical properties in fabricating the MLCC.

• Electrical & Electronic Materials
• /
• v.3 no.4
• /
• pp.271-278
• /
• 1990

본 논문에서는 내부전극 Pt를 갖는 적층형 압전액튜에이터의 제조와 적층수에 따른 압전액튜에이터 압전특성에 대해 조사 연구하였다. 먼저, Dr.blade방법을 사용하여 두께 ~220.mu.m의 PZT green sheet를 제작하였다. green sheet의 밀도는 결합제 양과 외부압력에 대해 크게 의존하였으며 소결체의 밀도는 green sheet의 밀도가 커질수록 더 높게 나타났다. 다음에는 적층수에 따른 압전정수의 변화에 대한 것으로써 압전정수(d$_{33}$)는 PZT세라믹스의 적층수가 증가할수록 매우 크게 증가되었으며 압전정수를 도입하여 계산된 변형량(.DELTA.l/l)은 10층 시편에 대해 2*$10^{6}$V/m의 전계에서 3*$10^{-3}$값을 얻었다. 이와같은 결과로써 적층형 압전액튜에이터는 저전압에서도 큰 변위를 나타내며 따라서 제어장치의 미세작동에 충분히 이용 될 수가 있다.다.

• Journal of the Korean Institute of Rural Architecture
• /
• v.17 no.2
• /
• pp.9-16
• /
• 2015

This study comparatively analyzed thermal characteristics of the green color, which is currently used the most, and other various colors of a rooftop urethane water proofing sheet. This study also analyzed the cooling performance by color of the water proofing sheet that fused cooling paints, and presented the effective water proofing sheet color for building energy savings. The experimental results are as follows: (1) The value of L (brightness) diminished, and brilliance also became lower from the white color to the black color, and thus, it was confirmed that relatively more heat was absorbed. In a and b chromaticity, which is the color attribute that ignores brightness, no special relationship was identified. (2) Considering that the cooling performance effect is bigger in summer than winter, due to heat reflection, the white water proofing sheet is more effective in building energy savings than the green water proofing sheet that is currently used the most. (3) The water proofing sheet's color has an impact more on cooling performance than the color of the background side of a structure on which water proofing sheet is installed. The experiment object of gray, of which background side is similar to cement mortar, was lower by $5.7^{\circ}C$ than the white background side.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2006.11a
• /
• pp.71-74
• /
• 2006

The introduction of materials and methods of construction which are appropriated to property of green roofs could be a decisive factor in a long-range durability and economical maintenance cost, moreover, it support to variety construction system and organization. In this paper I focused to assure the basic system for waterproofing materials and root barrier apply to green roof as searching the application of field condition. And I suggest proper waterproofing and root barrier as considering the mutual connection and plant growth. and it can be a standard model to adopt to domestic green roof system.

• Journal of the Korea Institute of Building Construction
• /
• v.18 no.5
• /
• pp.463-469
• /
• 2018

A currently used roof green system with multi layers has a low constructability. Therefore a new integrated waterproof & root barrier sheet and roof green box unit system was developed using steel plate fixture and cone type fixture by electromagnetic induction heating method. This study was proceeded to evaluate adhesion performance of two types of fixtures on Engineering PE, TPO, PVC sheet in a normal condition, repeated heating and cooling condition. As a result, adhesion load on Engineering PE sheet showed the highest value. The adhesion loads of steel plate fixture showed higher value as heating temperature was getting higher. However adhesion loads of cone type fixture showed opposite tendency. Regarding to the test conditions, test results of normal condition, repeated heating and cooling condition showed same value. The cone type fixture using butyl tape showed 7 times lower adhesion load than that of cone type fixture using electromagnetic heating and 28% lower adhesion load in a repeated heating and cooling condition than a usual condition.

• Transactions of Materials Processing
• /
• v.14 no.3 s.75
• /
• pp.277-281
• /
• 2005

LTCC(Low temperature co-fired ceramic) is being recognized as a significant packaging material of electrical devices for the advantages such as relatively low temperature being needed for process, low conductor resistance and high printing resolution. In the process of LTCC electrical devices, the punched via-hole quality is one of the most important factors on the performance of the device. However, its mechanism is very complicated and optimization of the process seems difficult. In this paper, to clarify the process, via-hole punching experiments were carried out and the punched holes were examined in terms of their burr formation. The effects of thickness of PET sheet, ceramic sheet and punch-to- die clearance on via-hole quality were also discussed. Optimum process conditions are proposed and a factor $\kappa$ is introduced to express effect of the process variables.

• Journal of the Microelectronics and Packaging Society
• /
• v.11 no.3 s.32
• /
• pp.77-82
• /
• 2004

In this paper, warpages of heterogeneous LTCC substrates comprised of high K/low K hi-layered structure were investigated. The effect of glass content in high K LTCC layer on the warpage of substrate during co-firing process was examined. Shrinkage and dielectric properties of high K and low K green sheets were measured. In-situ camber observation by hot stage microscopy showed different camber development of heterogeneous LTCC substrates according to glass content in high K green sheet. High K green sheet containing $50\%$ glass was matched to low K green sheet in the shrinkage. Therefore, LTCC substrate of Low K/High K+$50\%$ glass structure showed flat surface after sintering.

• Proceedings of the Korean Ceranic Society Conference
• /
• 2003.10a
• /
• pp.170.1-170
• /
• 2003

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2010.06a
• /
• pp.233-233
• /
• 2010

It is important to form the n+ emitter layer for generating electric potential collecting EHP(Electron-Hole Pair). In this paper the formation on the n+ emitter layer of silicon wafer has been made with respect to uniformity of shallow diffusion from a liquid source. The starting material was crystalline silicon wafers of resistivity $0.5{\sim}3\{Omega}{\cdot}cm$, p-type, thickness $200{\mu}m$, direction[100]. The formation of n+ emitter layer from the liquid $POCl_3$ source was carried out for $890^{\circ}C$ in an ambient of $N_2:O_2$::10:1 by volume. And than each conditions are pre-deposition and drive-in time. It has been made uniformity of at least. so, the average of sheet resistance was about 0.12%. In this study, sheet resistance was measured by 4-point prove.