• Title/Summary/Keyword: Barrier design

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Effects of Healing Agent on Crack Propagation Behavior in Thermal Barrier Coatings

  • Jeon, Soo-Hyeok;Jung, Sung-Hoon;Jung, Yeon-Gil
    • Journal of the Korean Ceramic Society
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    • v.54 no.6
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    • pp.492-498
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    • 2017
  • A thermal barrier coating (TBC) with self-healing property for cracks was proposed to improve reliability during gas turbine operation, including structural design. Effect of healing agent on crack propagation behavior in TBCs with and without buffer layer was investigated through furnace cyclic test (FCT). Molybdenum disilicide ($MoSi_2$) was used as the healing agent; it was encapsulated using a mixture of tetraethyl orthosilicate and sodium methoxide. Buffer layers with composition ratios of 90 : 10 and 80 : 20 wt%, using yttria stabilized zirconia and $MoSi_2$, respectively, were prepared by air plasma spray process. After generating artificial cracks in TBC samples by using Vickers indentation, FCTs were conducted at $1100^{\circ}C$ for a dwell time of 40 min., followed by natural air cooling for 20 min. at room temperature. The cracks were healed in the buffer layer with the healing agent of $MoSi_2$, and it was found that the thermal reliability of TBC can be enhanced by introducing the buffer layer with healing agent in the top coat.

A Study on the Analysis of the Current and the Demand of the House for the Blind (시각장애인 주택의 실태 및 요구도 분석에 관한연구)

  • Kim, Sang-Woon;Kang, Byoung-Keun;Soong, Ki-Chang;Park, Kwang-Jae;Yun, Young-Sam;Jung, Eun-Young
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.15 no.1
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    • pp.41-52
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    • 2009
  • Increasing the old and the senile disability, it is increased that the demand of barrier-free house for the disabled, the senior, the pregnant and the young is strongly increasing recently. In this reason, this study focuses the problems of the house which is used by the Blind through the investigation of current status and tries to find out the differences between disability's demand and current design of their house. As well, through the research and analysis some cases of the residential alterations this study verifies what the demand is on each room and their need is committed correctly during the residential alterations. It is the purposes of this study finding the problems through these research and analysis. Thus this study investigates houses of the Blind and finds out their house type, scale and daily life through the statistical data and documentary survey and also, investigates current status of their house. The basic standard for the current status and the demand analysis is researched by the barrier factors which are deducted from the former study.

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Fabrication of Paper-based Biosensor Chip Using Polydimethylsiloxane Blade Coating Method (PDMS 블레이드 코팅법을 이용한 종이-기반 바이오센서칩 제작)

  • Jeong, Heon-Ho;Park, Chami
    • Korean Chemical Engineering Research
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    • v.59 no.1
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    • pp.100-105
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    • 2021
  • This paper proposes the polydimethylsiloxane (PDMS) blade coating method for fabrication of paper-based analytical device (PAD) that is able to monitor the disease diagnosis and progress without special analytical equipment. The mold that has PAD design is easily modified by using laser cutting technique. And the fabricated mold is used for hydrophobic barrier formation by blade coating. We have optimized the stable formation of PDMS hydrophobic barrier as blade coating condition, which is established by analyzing the structure of the PDMS hydrophobic barrier and change of hydrophilic channel size as thickness of the ink and contact time with the chromatography paper. Based on optimal condition, we demonstrate that PAD as biosensor can apply to detect protein, glucose, and metal ion without special analysis equipment.

A Study on Universal Design Guideline of the Urban Railway Station: Platform (도시철도 역사 승강장의 유니버설 디자인 기준에 관한 연구)

  • Kang, Byoung Keun;Kim, Sang Woon;Shin, Dong Hong;Lee, Joo Hyung;Lee, Ju Yeon
    • Journal of The Korea Institute of Healthcare Architecture
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    • v.21 no.2
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    • pp.35-43
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    • 2015
  • Purpose: A large number of the mobility impaired have increasingly used the railway station, so the application of UD(Universal Design) on urban railway station has been interested. However, the current criteria used in domestic areas have concerned about the effective administration of railway station facilities rather than the needs of he mobility impaired. Of diverse facilities in railway station, the platform is considered as an important space due to many transportation users' riding or transfer in railway stations. Therefore, this study aims to explore the detailed criteria in adapting ideas from UD to platform within railway station. Methods: This study explores the criteria by evaluating findings from previous studies. First, all criteria related to platform in domestic and foreign areas are taken together and analyzed, and appropriate criteria first are established. Based on these, the current situation of platform facilities in railway station is evaluated. Then, the detailed criteria applicable to railway station platform are concluded, by reviewing types of the mobility impaired and principles of UD. Result: Findings from this study are as follows. First, the current criteria applied to railway station platforms lack ideas of UD, while the criteria used in foreign countries adequately reflect the ideas of UD on railway station platforms; therefore, the better criteria applicable to platform facilities in domestic railway station are necessary. Second, standard criteria used in domestic areas with newly additional criteria suggest that platform facilities should be established according to those criteria. Taken together, the better platform facilities should be provided to railway users through the application of UD to railway station platforms. Implications: For the future users in railway station platforms, the additional research on criteria of UD as well as diverse types of spaces within railway stations should have been continued.

A Study on Improvement of Crash Discrimination Performance for Offset and Angular Crash Events Using Electronic X-Y 2-Axis Accelerometer (전자식 X-Y 이축 가속도 센서를 이용한 오프셋 및 경사 충돌에 대한 충돌 판별 성능 개선에 관한 연구)

  • 박서욱;전만철
    • Transactions of the Korean Society of Automotive Engineers
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    • v.11 no.1
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    • pp.128-136
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    • 2003
  • In today's design trend of vehicle structure, crush zone is fiequently reinforced by adding a box-shaped sub-frame in order to avoid an excessive deformation against a high-speed offset barrier such as EU Directive 96/97 EC, IIHS offset test. That kind of vehicle structure design results in a relatively monotonic crash pulse for airbag ECU(Electronic Control Unit) located at non-crush zone. As for an angular crash event, the measured crash signal using a single-axis accelerometer in a longitudinal direction is usually weaker than that of frontal barrier crash. Therefore, it is not so easy task to achieve a satisfactory crash discrimination performance for offset and angular crash events. In this paper, we introduce a new crash discrimination algorithm using an electronic X-Y 2-axis accelerometer in order to improve crash discrimination performance especially for those crash events. The proposed method uses a crash signal in lateral direction(Y-axis) as well as in longitudinal direction(X-axis). A crash severity measure obtained from Y-axis acceleration is used to improve the discrimination between fire and no-fire events. The result obtained by the proposed measure is logically ORed with an existing algorithm block using X-axis crash signal. Simulation and pulse injection test have been conducted to verify the performance of proposed algorithm by using real crash data of a 2,000cc passenger vehicle.

A Basic Study on the Application of Text-Maining Method for Qualitative Evaluation through Barrier Free Certification in School Facilities (학교시설의 장애물 없는 생활환경(Barrier Free) 인증 사례를 통한 정성평가 텍스트마이닝 기법 적용에 관한 기초연구)

  • Yun, Pyeong-Se;Lee, Jong-Kuk
    • The Journal of Sustainable Design and Educational Environment Research
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    • v.19 no.1
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    • pp.25-35
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    • 2020
  • Since the introduction and operation of BF certification, a total of 6,432 certificates has been issued until February 2020, of which educational research facilities make 1,091 cases (754 preliminary certification, 337 main certification) out of 6,237 buildings, acquiring BF certification of about 20%. Qualitative evaluation is conducted with focus on the three items of BF-certified building evaluation index, which are medium facilities, internal facilities, and sanitary facilities, and major keywords are the deducted through the Text Mining analysis of the derived results. As a result, problems with access paths occurred in the case of the facilities, and assessment indicators for users were found to be necessary among the assessment of the steps of the internal facilities. Finally, we could see that sanitation facilities needed to improve toilets installed in residential development facilities. Based on the results obtained, the study seeks to suggest directions for improving the evaluation index required for BF-certified school facilities.

Development of Multi Dielectric Barrier Discharge Plasma Reactor for Water Treatment (수처리용 다중 유전체 방벽 방전 플라즈마 반응기 개발)

  • Kim, Dong-Seog;Park, Young-Seek
    • Journal of Environmental Science International
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    • v.22 no.7
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    • pp.863-871
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    • 2013
  • Dielectric discharges are an emerging technique in environmental pollutant degradation, which that are characterized by the production of hydroxyl radicals as the primary degradation species. For practical application of the plasma reactor, reactor that can handle large amounts of water are needed. Plasma research to date has focused on small-scale water treatment. This study was carried out basic study for scale-up of a single DBD (dielectric barrier discharge) plasma reactor. The degradation of N, N-Dimethyl-4-nitrosoaniline (RNO, indicator of the generation of OH radical) was used as a performance indicator of multi-plasma reactor. The experiments is divided into two parts: design parameters [effect of distance of single plasma module (1~14 cm), arrangement of ground electrode (single and multi), rector number (1~5) and power number (1~5)]; operation parameter [effect of applied voltage (60~220 V), air flow rate (1~5 L/min), electric conductivity of solution ($1.4{\mu}S/cm$, deionized water)~18.8 mS/cm (addition of NaCl 10 g/L) and pH (5~9)]. Considering the electric stability of the plasma reactor, optimum spacing between the single plasma module was 2 cm. Multi discharge electrodes - single ground electrode array was selected. Combination of power 3-plasma module 5 was the optimal combination for maximum RNO degradation. The optimum 1st voltage and air flow rate for RNO degradation were 180 V and 4 L/min, respectively. The pH and conductivity of the solution was not influencing the RNO degradation.

Study on Landscape Preference of Debris Barriers Types (사방댐의 유형별 경관선호 분석)

  • Lee, Sang-Won;Kang, Mi-Hee;Lee, Heon-Ho
    • Journal of Korean Society of Forest Science
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    • v.100 no.2
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    • pp.283-291
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    • 2011
  • The purpose of this study was to identify the public's preferences of different types of debris barriers and the impacts of construction materials, design, size, and planting on landscape preferences. On-site survey was carried out in Mt. Palgong during on December, 2009 and a total 122 visitors' data were analyzed. A total of 82 students Yeungnam and Donga University were also questioned in the classes during on December, 2009. Survey results showed that the debris barrier constructed with natural materials such as stone were more preferred and the level of planting around the debris barrier impacted most on the landscape preferences. The results imply that the importance of eco-friendly construction materials and methods has been increased in term of not only environmental conservation but also people's preferences. Therefore, the factors for enhancing landscape of debris barrier should be considered synthetically in terms of construction material, design, size, and planting level.