• Title/Summary/Keyword: waterproof characteristics

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Plan for the Development of a Standardized Dummy for Persons in Need of Rescue in a Confined Space (밀폐공간 구조 요구자를 위한 더미 표준화 개발 방안)

  • Choi, Seo-Yeon;Rie, Dong-Ho;Kim, Hyung-Jun
    • Journal of the Korea Safety Management & Science
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    • v.18 no.4
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    • pp.99-105
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    • 2016
  • This study was conducted to develop a dummy in an environment similar to the human body, to prepare a standard for evaluation and to present the process of the production in order to evaluate the performance of the robot that can detect the persons needing rescue in a confined space, who are difficult for fire-fighting officials to rescue in case of fire and disaster. As a result, a standard for evaluation was developed and standardized into four parts 'Normal,' 'Risk Stage 1,' 'Risk Stage 2' and 'Risk Stage 3'based on the number of breath cycles, carbon dioxide concentration, core temperature and criteria for hearing to recognize the voice. In addition, in order to produce a dummy, fever, breathing capacity and voice output function were compared and analyzed. This study has significance that it built up basic data of the method of producing the actual dummy, by presenting characteristics and controlling methods using the waterproof insulation heating coil for the function, solenoid valve for the consecutive output of breathing capacity and USB program sound board for voice output.

Analysis of the change in appearance according to the hardening method of leather (가죽의 경화방법에 따른 외형변화 분석)

  • Youshin, Park
    • Journal of Fashion Business
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    • v.26 no.5
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    • pp.122-134
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    • 2022
  • This study is conducted on hardening leather with improved firmness and stability of shape, based on research on types and thickness of leather. The purpose of this study is to test the physical properties of the leather for molding to prepare the foundation for leather molding based on the test results using four methods by thickness of Vegetable and Split. The tests were conducted using a total of five leather types, including three types of vegetable leathers and two types of split, by thickness. Based on the testing method for leathers in KS M 6882, the tests were performed at 27℃ with relative humidity of 65±20%. The samples were prepared with cowhide, size 9cm× 2cm. The measurement parameters are length and width. thickness, volume, mass, density. Regarding the hardening treatment method, changes in appearance and major physical characteristics of leather were reviewed by soaking in hot water, dry heating, hammering, waxing, and olive oil coating. The study results are as follows. In planar works, it is judged that hardening work using a hammer is more suitable for stiffness or density in order to prevent easy breakage with adult muscle density, rather than boiling water or baking. In conclusion, there is no curling, soot, or breaking phenomenon, and the densest curing method is 50℃ for 20 sec of V2 and 75℃ for 60 sec of V2 in boiling water. The combination of paraffin treatment improve waterproof and quality.

Analysis of underground post-tensioned precast concrete box utility tunnel under normal fault displacement

  • Wu, Xiangguo;Nie, Chenhang;Qiu, Faqiang;Zhang, Xuesen;Hong, Li;Lee, Jong-Sub;Kang, Thomas H.K.
    • Computers and Concrete
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    • v.29 no.2
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    • pp.69-79
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    • 2022
  • For long underground box utility tunnels, post-tensioned precast concrete is often used. Between precast tunnel segments, sealed waterproof flexible joints are often specified. Fault displacement can lead to excessive deformation of the joints, which can lead to reduction in waterproofing due to diminished contact pressure between the sealant strip and the tunnel segment. This paper authenticates utilization of a finite element model for a prefabricated tunnel fault-crossing founded on ABAQUS software. In addition, material parameter selection, contact setting and boundary condition are reviewed. Analyzed under normal fault action are: the influence of fault displacement; buried depth; soil friction coefficient, and angle of crossing at the fault plane. In addition, distribution characteristics of the utility tunnel structure for vertical and longitudinal/horizontal relative displacement at segmented interface for the top and bottom slab are analyzed. It is found that the effect of increase in fault displacement on the splice joint deformation is significant, whereas the effects of changes in burial depth, pipe-soil friction coefficient and fault-crossing angle on the overall tunnel and joint deformations were not so significant.

Study on Cause Analysis of Capsizing Accident in Fishing Boat No. 66 Poongsung (어선 제66풍성호 전복사고 원인분석에 대한 연구)

  • Lee, Li-Na;Lee, Chang-Hyun;Ohn, Sung-Wook
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.6
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    • pp.955-964
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    • 2022
  • According to the statistics of maritime accidents statistics that have occurred in Korea over the past five years, maritime accidents caused by fishing boats have increased every year from 1,646 in 2016 to 2,100 in 2020. In particular, of the 378 capsizing accidents that have occurred in the past five years, 252 capsizing accidents of fishing boats account for a high proportion of 66.7%, therefore, it is urgent to come up with countermeasures. In this study, to determine the cause of the capsizing accident of fishing boat No. 66 poongsung, data such as stability and seawater inflow routes were collected, and the effects of waterproof, additional wood decks, and windbreakers on stability on were quantitatively analyzed. Additional decks, windbreakers, and waterproof installed in No. 66 poongsung cause initial list, deteriorate stability, and fail to meet fishing boat structural standards. In addition, it was analyzed that the stability was weakened due to the characteristics of the hull shape of No. 66 poongsung. To estimate the stability at the time of the accident, the stability at the time of the working in the fishing ground condition, amount of seawater inflow according to the change in sea conditions, hull oscillation situation, and change in stability due to the hull factor were calculated. As a result, the minimum GoM was satisfied at the time of working in the fishing ground, but it could not be restored at the maximum wave height of 4 m, and the minimum GoM was not satisfied at the maximum wave height of 4 m owing to the influence of seawater inflow and oscillation due to the hull list. However, the minimum GoM was satisfied if additional decks and windbreakers installation was excluded among the factors affecting the stability of No. 66 poongsung.

A Study on the Cutoff time and the Malfunction Current Characteristics of RCDs (누전차단기 동작시간 및 부동작 전류 특성)

  • Han, Woon-Ki;Shong, Gil-Mok;Kim, Yong-Seok;Kim, Dong-Wook;Choi, Chung-Seog;Lee, Bok-Yong;Park, Sang-Tae
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • 2005.05a
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    • pp.61-65
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    • 2005
  • This paper describes the cut off time and the current characteristics of virgin RCDs and deteriorated ones in the seashore. The RCDs(Residual Current Protective Devices) are used for protecting the human body from electrical shock and for preventing facility accidents. According to the Korean standards, the RCDs are installed in panel boards. When RCDs are installed outside, they must be enclosed inside waterproof cases. In the case that RCDs are employed at temporary power sites and electrical facilities on the road they are exposed to the external environment. As a result, the RCDs deteriorated in the seashore for 3 months showed high failure rate, while the virgin RCDs all complied with Korean Standard. Considering that the RCDs are used under exposed condition outside, the reliance of RCDs must be ensured by modifying the related regulations and codes and by developing improved advanced in their performance.

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Characteristics of Housing Condition for Physically Challenged Persons in Rural Area from the Viewpoint of Planning Customized Housing for the Disabled (장애인 맞춤형 주택 계획 관점에서 본 농촌지역 지체장애인 주거특성 연구)

  • Lee, Yeun-Sook;Park, Ji-Young;Lee, Dong-Joo
    • Korean Institute of Interior Design Journal
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    • v.24 no.6
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    • pp.154-162
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    • 2015
  • As there is no case study with current status, measurements or description on the state of actual site of rural area only, the delivery of actual conditions about such an area is significantly limited. The purpose of this study is to pinpoint issues with housing conditions of low-income family with disabled members in the rural area. For such a purpose, 25 households of disabled people have been visited for interview, on-site research and survey, of which results are summed up in this paper as following: First, average monthly income of such family turned out to be KRW 480,000, most of which is from the government subsidy. High ratio of such families has resided in a house with average size of approximately 56m2 for about 24 years. Secondly the most needed maintenance work with top priority was for the toilet, and many of the interviewees expressed their discomfort about small size of their bathrooms and inconvenient facilities therein. Thirdly, most of such houses had too high thresholds that posed danger and inconvenience. Such thresholds had average height of 13cm, which can be considered as completely inconsiderate of disabled users. Fourth issue was that these people needed safety handle that will enable them to stand up or to be in the standing posture in the living room and bedroom where they spend most of their time. Fifthly, they wanted finishing materials with waterproof functionality as well as replacement of finishing materials and wallpaper which were too old and caused hygiene issues. As these issues represent, current housing for disabled people in the rural area turned out to be poor and risky space rather than the place where difficulty of individual situation can be resolved or their disability can be complemented. Thus it can be determined that now is the time to arrange the solutions for such housing difficulties and to establish customized housing plan to ensure safety and convenience.

Time-dependent characteristics of viscous fluid for rock grouting (암반 그라우팅을 위한 점성유체의 시간의존 특성 분석)

  • Lee, Jong-Won;Kim, Ji-Yeong;Weon, Jo-Hyun;Oh, Tae-Min
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.24 no.6
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    • pp.465-481
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    • 2022
  • Rock grouting is important to improve the waterproof efficiency and mechanical strength of rock medium with joint for utilizing the underground rock space such as tunnel. The grouting materials typically has been used the cement materials, which represent Bingham fluid model. This model can express the relationship of viscosity and yield strength. In addition, it is dependent with elapsed time. The grouting injection performance can be deteriorated with an increase of viscosity and yield strength in the grouting process if the time dependence is ignored. Therefore, in this study, the characteristics of viscosity and yield strength were investigated according to water-cement ratio and time dependence in the laboratory test. Numerical simulation was carried out to investigate the grouting performance according to the time dependence of characteristics in terms of the viscosity model. Given the results, the grouting injected distance and cumulative grout volume were significantly decreased when the time dependence of grouting material was considered. This study, considering the characteristics according to the time dependence of viscosity and yield strength, will be meaningful to the design of grouting injection in field applications.

A Study on Emission Properties of Green House Gas on Duration Combustion of Constructive Wood Materials (건축용 목재의 연소시 지구온난화 가스의 배출특성에 관한 연구)

  • An, Hyung-Hwan
    • Journal of the Korean Institute of Gas
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    • v.22 no.6
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    • pp.123-128
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    • 2018
  • MDF was treated on the surface of MDF with fire retardant lacquer, water-soluble flame retardant coat and water-soluble wood cover on the MDF wood, and the pyrolysis characteristics and the atmospheric noxious gas generation characteristics were investigated by using the large capacity thermal analyzer. As a result of investigating pyrolysis and combustion gas generation characteristics after treatment of 0.11 / 11.55 g in terms of mass ratio, it was found that combustion starting time was slightly longer than that of pure MDF in the case of treatment with fire retardant lacquer. The combustion temperature was increased from $340^{\circ}C$ to $450^{\circ}C$. The pyrolysis and combustion gas generation characteristics of the MDF wood treated with the aqueous flame retardant coat showed the changes in combustion starting time and temperature from $260^{\circ}C$ to $542^{\circ}C$ for about 26 minutes at the mass ratio of 0.13 / 11g. Also, when the commercially available waterproof wood cover was treated with 0.13 / 11.55 g of MDF, the sudden weight change tended to increase from $300^{\circ}C$ to $370^{\circ}C$ and showed a second change at approximately $500^{\circ}C$.

Examination of Development State of Smart Fiber in Korean Textile Industry - Focused on Companies in Daegu/North Gyeongsang Province - (한국 섬유기업의 스마트섬유 개발 동향 - 대구경북지역 업체를 대상으로 -)

  • Yoo, Hwa-Sook;Park, Kwang-Hee
    • Journal of the Korean Society of Clothing and Textiles
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    • v.31 no.8
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    • pp.1262-1272
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    • 2007
  • The purpose of this study was to examine the development trend of smart fiber by textile companies in Daegu/North Gyeongsang Province. This examination includes the development fields of smart fiber, investment size, information sources and the use degree of those, research-related infrastructure, relationship between companies' characteristics and their interests in smart fiber. Research data were collected by a survey. The definition and classification(4 areas and 12 development products) of smart fiber followed ones of Smart Fiber Technology Roadmap by the Ministry of Commerce, Industry and Energy. Data were analyzed using SPSS 11.0 program for frequency, means, t-test, and $X^2$-test. Among respondents, the numbers of dying and finish companies and export traders were the highest. It revealed that 19.6% of companies were developing smart fibers. Within 12 development products, vapor permeable/waterproof fiber showed to be most being developed, while medical fiber for human has not been developed and wasn't made an investment plan for developing. It was discovered that the biggest problem of smart fiber development was the lack of experts and the best outcome of smart fiber development was preoccupation of future market. It showed that companies got information from textile fairs but didn't often use information sources. The companies appeared to have a weak intention about research of smart fiber. The more important a company considered functionality of textile products and the more innovative and stabler the company was, the higher interest in smart fiber companies had. It was concluded that textile companies in Daegu/North Gyeongsang Province were aware of the importance of smart fiber development but they were not strongly interested in it and not enthusiastic in taking action on it.

Development of Perfluoroalkyl Derivative for $Cr^{3+}$ Adsorbent Promotion Process (3가 크롬 흡착 증진용 과불소 알킬유도체 제조 및 적용공정 개발)

  • Shin, Jong-Sub;Kum, Chang-Hun;Yun, Jong-Kuk;Park, Il-Kyu
    • Clean Technology
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    • v.14 no.3
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    • pp.193-203
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    • 2008
  • A surfactant is used to assist the effect of cleaning, dispersibility and adhesion during leather manufacturing process. Existing surfactant for that process includes many hydrophilic groups that may cause problem such as stain, bad water resistance and poor durability, etc. It is potential problem to make high-performance property for future leather market. In this study, we have synthesized the fluorinated surfactant of which property decreases surface tension, increases dispersion, cleaning effect and the better chrome absorption by the high bond energy of C-F to complement weakness that the present alkyl derivative surfactants have. Using fluorinated surfactant, we can confirm that dispersion is increased, chrome absorption ratio is augmented with high osmosis and coherence, chrome content in the tanning waste water is reduced, BOD and COD contents are diminished and physical characteristics are improved.

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