• 대한토목학회논문집
• /
• 제40권5호
• /
• pp.485-496
• /
• 2020

잠제와 인공리프와 같은 수중구조물은 연안역의 침식 등의 대책으로 일반적으로 사용되고 있다. 본 연구에서는 Tetrapod로 제체를 형성한 투과형 수중구조물을 대상으로 파랑의 전달에 대한 2차원 수리실험을 수행하였다. 수리실험은 서로 다른 상대여유수심, 상대여유고, 상대상단폭 및 파형경사 등을 적용하여 수행되었다. 수리실험결과를 이용하여 투과형 수중구조물에 의한 파고전달계수 산정식을 제안하였다. 제안된 경험식은 파고전달계수를 충분한 정도로 예측함을 확인하였으며, 기존 경험식을 개선하였다.

• 한국방재학회 논문집
• /
• 제11권2호
• /
• pp.193-198
• /
• 2011

본 연구에서는 최근 추세에 맞춰 개발사업시 장치형 및 자연형등의 인위적인 비점오염저감시설이 아닌 시설지를 투수성 포장재를 사용할 경우 얻어지는 효과를 분석하여, 설계 및 시공시 투수성 포장재 적용을 위한 기초자료를 제공하고자 한다. 그 방법으로 개발시 대상지의 면적을 불투수성과 투수성 개발로 분리 적용하여 삭감오염부하량 및 설치 공사비의 경제성을 비교 분석하였다. 그 결과 비점오염원의 처리용량 및 삭감부하량은 투수성 및 불투수성 개발에 많은 영향을 받으며, 개발시 비점오염저 감시설을 장치형이나 자연형을 단독으로 설치하기 보다는 처리대상 유역을 투수성 지역으로 개발하는 것이 배출부하량이 적은것으로 나타났다. 이를 토대로 개발시 비점오염의 관리를 위해 불투수율 면적비를 일정수준으로 제한하는 대책을 수립하면 개발에 따른 오염원의 최소화가 가능할 것으로 생각된다.

• Journal of the Korean Society for Industrial and Applied Mathematics
• /
• 제13권2호
• /
• pp.123-140
• /
• 2009

The effect of a solute concentration difference on the osmotic transport of water through the semi-permeable membrane of a simple cell model is investigated. So far, most studies on osmotic phenomena are described by simple diffusion-type equations ignoring all fluid motion or described by Stokes flow. In our work, as the governing equations, we consider the coupled full Navier-Stokes equations which describe the fluid motion and the full transport equation that takes into account of convection and diffusion effects. A two dimensional finite difference model has been developed to simulate the velocity field, concentration field, and semi-permeable membrane movement. It is shown that the cell swells to regions of lower solute concentration due to the uneven water flux through the semi-permeable membrane. The simulation is applied on a red blood cell geometry and the relevant results are presented.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
• /
• pp.130-135
• /
• 2000

The purpose of this study is to examine the physical properties of water-permeable concretes. The water-permeable concrete with cement-aggregate ratios of 1:3.5 to 1:6.0 and two type of coarse aggregate size of 8~13 and 13~18mm used OPC(ordinary portland cement) as a binder and superplasticizer are prepared, and then tested for flexural strength, compressive strength, compressive strength, continuous void percentage and coefficient of water permeability. It is concluded from the test result that the superior flexural and compressive strengths, coefficient of water permeability and continuous void percentage of water-permeable concretes that use OPC were obtained at cement-aggregate ratios of 1:3.2, 1:6.0 respectively, The water-permeable concretes with coarse aggregate of 8~13 and 13~18mm size used OPC as a binder havinga flexural strength of 24.81~45.56kgf/$\textrm{cm}^2$, 21.99~40.62kgf/$\textrm{cm}^2$, a compressive stength of 93.63~ 242kgf/$\textrm{cm}^2$, 114.8~191.7.kgf/$\textrm{cm}^2$, a coefficient of permeability of 0.59~1.85kgf/$\textrm{cm}^2$, 0.73~ 2.25kgf/$\textrm{cm}^2$, and a continuos void percentage of 16.6~26.32%, 13.52~24.35% respectively during 28 curing days.

• 한국생활과학회지
• /
• 제10권4호
• /
• pp.333-347
• /
• 2001

The purpose of this study is to find out the washing methods specified on the care labels of vapor-permeable & water-proofed fabrics and to investigate the consumers' real washing methods in their home and their cognition. In this study, the condition of care labels on 35 products was investigated and consumers' washing methods and cognition were surveyed. The subjects were consisted of majoring clothing textiles' female, female student attending in other major and married-women. Data were analyzed SPSS 10.0. The major results were as follows : 1. The care labels of Vapor-permeable & waterproofed fabric products used in this survey followed the rule of KS K that is stated that care labels must include over 3 instructions. It was the most popular type of care labels to organize with washing methods, bleaching methods, weaving methods, drying methods, ironing methods. 2. Most consumers have vapor-permeable & waterproofed fabric products, but their consciousness of this fabric is low. The rate of consumer confirming the care labels was 76.6% but 67.8% of them answered they take care of textile products with their experiences. 3. Consumers' understanding of care instructions on care labels was investigated that most consumers understand domestic care instruction, but they didn't know almost all international one.

• 한국과학교육학회지
• /
• 제27권2호
• /
• pp.144-152
• /
• 2007

In this study, high school science teachers' and students' various conceptions related to osmosis phenomena were compared with and analyzed in relation to the content of science textbooks used in high school science classrooms and college science courses. The questionnaires developed by the researchers were administered to science teachers and students. Differences can be found between the explanations of science textbooks on osmotic pressure and semi-permeable membranes. Many science teachers and students thought of osmotic pressure as 'membrane pressure occurred by the movement of a solvent'. Moreover, the types of teachers of semi-permeable membranes were similar regardless of their academic majors. Many of the teachers thought of a semi-permeable membrane as a membrane that 'passes small-size particles'; however, many students thought of this type of membrane as being 'selectively permeable'. Also, the salt-pickling cabbage phenomenon seemed to cause significant confusion to science teachers and students. These study results show that teachers and students possess various conceptions related to the osmosis phenomena. These different conceptions related to osmosis phenomena might cause confusion and diverse conceptions including misconceptions among teachers and students.

• 한국습지학회지
• /
• 제22권1호
• /
• pp.1-7
• /
• 2020

비점오염은 수계에 악영향을 끼치며 그 영향은 점차 커지고 있다. 이러한 비점오염을 관리하기 위해 정부에서는 LID(Low Impact Development) 시설의 연구와 다양한 효율평가를 시행하고 있다. 본 연구에서는 다양한 LID 시설 중 실제 설치된 투수 블록 시설의 강우 유출 억제를 위한 유출 저감율, 저류 강우량 분석 및 유출 지연시간 그리고 최대 유입 및 유출의 저감율을 분석했으며, 그 결과를 각 시설 간 비교했다. 불투수블록, 필터형 투수블록, 틈새형 투수블록 순서대로 분석 결과 저감 효율이 높게 나타났으며, 이를 통해 강우강도-유출지연시간간의 관계를 나타낸 그래프를 제시하였다. 이 그래프를 통해 앞으로 설계 시, 본 시설과 유사한 투수블록 시설의 재현 기간에 따른 시설 용량 선정 등의 설계에 도움을 줄 수 있으리라 생각한다.

• 한국입자에어로졸학회지
• /
• 제10권3호
• /
• pp.109-117
• /
• 2014

In Korea, permeable protection clothes for chemical agent is being developed and distributed. But permeable protection clothes are vulnerable for biological agent of particle type. Therefore selective permeable membranes are being developed to protect chemical agent and biological agent simultaneously. In this study, aerosol collection efficiency test was performed to validate the protection performance of permeable clothes and selective permeable membranes. Aerosol collection efficiency test was performed by using the aerosol test equipment that could test aerosol particle diameter from $0.005{\mu}m$ to $3.0{\mu}m$. This study shows the test method and performance test results for collection efficiency by using the aerosol test equipment.

• 한국의류산업학회지
• /
• 제23권1호
• /
• pp.129-141
• /
• 2021

This study investigated fabrics, washing and cares, design, pattern, subsidiary materials, and sewing methods with a focus on the functional outers using moisture-permeable waterproof fabric as a shell; in addition, each element was analyzed for differences depending on fabric type. The characteristics of 34 outers were investigated through labels, online product introductions, visual inspection, observations from two experts with more than 30 years experience and wear tests. Moisture-permeable waterproof fabrics used for the outer were classified into two types; in addition, the shell of the high-density fabric and the 2 & 3-layer fabrics had different characteristics. Various fabrics, detailed designs, and three-dimensional patterns suitable for each part of the human body were used to improve functionality. In addition, various subsidiary materials and sewing methods were used to form an organic relationship. The same washing and cares, patterns and subsidiary materials were used regardless of fabric type; however, the fabric type influenced the detailed design and sewing. The outers with high-density fabric had a loose fit, short placket, e-banded cuffs, lock-stitch, and lock-stitch+binding. However, the outer with 2 & 3 layer fabric had a slim fit, hood width adjustment, zippered pockets, cuffs with tab, seamless adhesive sewing such as laminating, lock-stitch+ seam-sealing, and welding.

• 한국지반신소재학회논문집
• /
• 제16권2호
• /
• pp.149-158
• /
• 2017

저수지 제방의 그라우팅시 가장 이상적인 주입형태는 침투주입이지만 일반적으로 침투와 할렬주입이 복합적으로 시공되어 원지반의 교란이 발생될 가능성이 존재한다. 이와 같은 문제점을 개선하기 위하여 이상적인 침투주입을 가능하게 하는 그라우트 재료를 이용하여 저압주입과 팽창제를 이용한 주입재의 팽창력으로 그라우팅 주입공 주변에 대한 다짐을 실시하고 순차적으로 그라우트재를 주입하는 방법이 유용하다. 본 연구에서는 그라우트 주입공 주변에 대한 침투다짐효과를 얻기 위하여 하이브리드형 주입재와 팽창제를 혼합한 침투다짐 그라우트를 PC(Permeable Compaction)팩커를 이용하여 주입한 그 효과에 대해 고찰하였다, 본 연구결과, PC팩커와 침투다짐 그라우트를 저수지 보수보강 그라우팅 공사에 적용할 경우 저수지 차수 그라우팅의 성능기준에 부합하는 침투다짐효과가 발휘될 수 있음을 확인하였다.