• 한국도로학회논문집
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• 제15권4호
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• pp.53-63
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• 2013

PURPOSES: The purpose of this study was to investigate the disintegration mechanism of concrete due to the infiltration of the moisture to the milling overlay pavement and to come up with a method to minimize the disintegration as well as verifying the effectiveness of the edge sealing and Fogseal method. METHODS : This study investigated the distress mechanism due to the infiltrated moisture remaining in the milling overlay pavement through chloride freezing test and verified the effectiveness of the sealing of the milling edge and fog seal methods, which have been devised to minimize the moisture infiltration, through laboratory water permeability test. Additionally, long-term pavement performance was compared for the effectiveness of the proposed method through under loading test, and field water permeability test was carried out to verify the field applicability of the proposed method. RESULTS: The result of the research confirmed that chloride deteriorates the concrete surface through disintegration and lowers its strength and that the laboratory moisture infiltration test verified the effectiveness of the milling edge sealing and fog seal methods in the deterrence of moisture infiltration to the overlay pavement with excellent long-term performance of the pavement treated with the proposed method. Although the field water permeability test revealed some deterrence of moisture infiltration of the milling edge sealing and fog seal methods to a certain extent, the difference was a little. CONCLUSIONS: The milling edge sealing and fog seal methods are limited in their effectiveness for the cases of improvident compaction management or mixture with large void, and it is believed that installation of subsurface drainage is more effective in these cases.

• 한국주조공학회지
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• 제21권3호
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• pp.163-178
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• 2001

The squeeze infiltration process is potentially of considerable industrial importance. The performance enhancements resulting from incorporation of short alumina fiber into aluminum are well documented. These are particularly significant for certain automobile components. Aluminum matrix composite automotive parts, such as diesel engine pistons or engine blocks are produced using squeeze casting apparatus or pressure die-casting apparatus. But the solidification process gets complicated with manufacturing parameters and the factors for porosity formation have not fully understood yet. In this study the formation of porosity during squeeze infiltration has been studied experimentally to achieve an improved understanding of the squeeze infiltration process for manufacture of short-fiber-reinforced components, particularly the mechanism of porosity formation. Al-based MMCs produced under a range of conditions were examined metallographically and the porosity characterised;a kind of matrix, an initial temperature of melt, and a volume fraction of reinforcement. The densimetry and the microscopic image analysis were done to measure the amount of porosity. A correlation between manufacturing parameters and defects was investigated through these.

• 한국수자원학회논문집
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• 제35권5호
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• pp.611-618
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• 2002

본 연구에서는 우수유출저감시설 중 침투형 집수정의 효과를 규명하기 위하여 성남, 오산, 청주지역에 설치된 시범시설에서 실시간으로 현장계측을 수행하고 이들 자료를 분석하여 그 효과를 정량화하였다. 현장 강우자료와 수위 자료를 토대로 자 지점에 설치된 일반집수정과 침투집수정에서의 강우량에 따른 유출량을 비교하여 유출저감율과 첨두유량저감율을 총강우량, 평균10분강우강도, 최대10분강우강도에 따라서 각각 비교 분석하였다. 각 지점의 현장자료를 통하여 침투집수정의 강우량에 따른 유출량을 일반집수정과 비교한 결과 1개의 침투집수정이 평균 70%의 총유출량저감율과 40∼70%의 첨두유량 저감효과를 나타내었다.

• 한국추진공학회지
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• 제23권2호
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• pp.68-77
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• 2019

고체 및 액체 로켓 추진 기관 내열부품으로 사용하기 위하여 C/SiC 복합 재료를 LSI(Liquid Silicon Infiltration) 공법으로 개발하였다. 조성비에 따른 내열 특성은 아크 플라즈마, 초음속 토치 시험으로 평가하였으며 $H_2O$ 및 $CO_2$ 산화에 의한 유효 삭마식을 제시하였다. 연소시험을 통하여 고체 및 액체 추진기관용 노즐목 삽입재, 확대부 내열재 및 연소실 내열부품 등 다양한 형상으로 제작이 가능함을 확인하였으며 높은 내삭마 성능과 열구조 성능이 입증되었다.

• 한국지반공학회논문집
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• 제32권2호
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• pp.31-41
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• 2016

강우유출수 비점오염 침투처리시설에 사용되는 모래와 제올라이트 필터에서 여재 파쇄가 침투에 미치는 영향을 분석하였다. 여재 파쇄의 원인으로 다짐에너지와 침투력의 영향을 검토하였다. 여재 파쇄가 침투에 미치는 영향을 조사하기 위해 비다짐 및 다짐 침투층에 대한 일차원 컬럼 침투시험을 수행하였다. 시험결과로부터 다음 결론을 얻었다. 1) 침투력에 의한 여재 파쇄량은 상대적으로 적은 것으로 분석되었다. 2) 다짐여재와 비교하여 비다짐여재는 파쇄량이 적고 침투에 따른 투수성 변화도 작다. 3) 부유오염물을 함유하지 않는 침투수가 침투하는 경우에도 파쇄된 여재의 재배열, 재이동이 원인으로 추정되는 투수성 감소가 발생하였다. 4) 여재 파쇄의 영향만을 고려한다면 필터 재료로서 모래의 적용성이 제올라이트 보다 양호함을 확인했다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
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• pp.184-188
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• 2001

The squeeze infiltration process is potentially of considerable industrial importance. The performance enhancements resulting from incorporation of short alumina fiber into aluminum are well documented. These are particularly significant for certain automobile components. But the solidification process gets complicated with manufacturing parameters and factors for porosity formation do not fully understand yet. In this study porosity defects were observed under several infiltrating conditions ; a kind of matrix, an initial temperature of melt, and a volume fraction of reinforcement. The desimetry and the microscopic image analysis were done to measure the amount of porosity. A correlation between manufacturing parameters and defects was investigated through these.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.229-230
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• 2011

We could see that, the thinner the retaining wall is, the more advantageous Premixed Agent Type Waterproof method is in the aspect of economic efficiency. The reason is because, in the case of Premixed Agent Type Waterproof method, the thicker the retaining wall is, the higher the construction cost increases due to increase in the material quantity required which increases in proportion to the area in the case of Premixed Agent Type Waterproof method. We could see that, the thinner the retaining wall is, the more inferior the economic efficiency of Infiltration Type Waterproof method is to that of Premixed Agent Type Waterproof method, as, in the case of Infiltration Type Waterproof method, the quantity of material required is fixed in proportion to the area. Consequently, we concluded that Premixed Agent Type Waterproof method is economically advantageous up to the wall thickness of 700 mm and Infiltration Type Waterproof from 800 mm.

• 대한토목학회논문집
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• 제31권1D호
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• pp.83-90
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• 2011

도로하부 혹은 성토부를 구성하는 다져진 지반재료들은 불포화상태로 존재하는 관계로 재료의 침투 혹은 배수에 대한 평가시 불포화지반의 특성이 반영하는 것이 필요하다. 이에 본 연구에서는 강우강도와 시간조건에서 도로하부 재료에서 어떠한 영향이 있는지를 파악하고자 수치해석적인 연구를 수행하였다. 기존의 실험을 통해 획득한 불포화 함수특성 자료를 활용하였으며 SWCC를 통하여 투수계수를 추정하였다. 제안된 방법을 통하여 시간 변화에 대한 침투 및 배수성능을 평가하였다. 연구결과 침투 및 배수 과정에서 초기흡수력의 여부와 함수특성곡선의 경로에 따라서 많은 영향을 받고 있음을 알 수 있다.

• Journal of Electrochemical Science and Technology
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• 제11권4호
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• pp.399-405
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• 2020

Hollow copper oxide/multi-walled carbon nanotubes (CuO/MWCNT) composites were fabricated via an optimized infiltration-reduction-oxidation method, which is more facile and easy to control. The crystalline structure and morphology were characterized by X-ray diffraction (XRD), and transmission electron microscopy (TEM). The as-prepared CuO/MWCNT composites deliver an initial capacity of 612.3 mAh·g^-1 and with 80% capacity retention (488.2 mAh·g^-1) after 100 cycles at a current rate of 0.2 A·g^-1. The enhanced electrochemical performance is ascribed to the better electrical conductivity of MWCNT, the hollow structure of CuO particles, and the flexible structure of the CuO/MWCNT composites.

• KIEAE Journal
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• 제13권2호
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• pp.13-20
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• 2013

Today, the world energy consumption in buildings occupies more than 30%. In our country, the energy consumption in buildings also occupies 25% of the entire national energy consumption. With the increasing demand of energy saving in architectural fields, there is a more interest in low-energy construction. For these low-energy housings, our country is planning to apply the energy-saving design standards at the level of passive houses in 2017. However, there is still a limitation in energy saving only with the standards on the performance of envelope in buildings. This means that unless a building is airtight even though it was well-insulated, cooling and heating energy consumption will increase due to the infiltration and leakage. Therefore, this study aims to make a comparative analysis of airtight performance by conducting a blower door test on the housings applied with passive designs, analyze the reasons why most houses fall short of the airtightness standards, and complement the airtightness problems in the inadequate parts of the buildings in order to save building energy.