• Title/Summary/Keyword: foreign materials

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Analysis of the Actual Conditions of the Asphalt Regulations by Fire Service Organizations and Explosion Cases (아스팔트에 대한 소방기관의 규제 실태와 폭발사례의 분석)

  • Lee, Eui-Pyeong
    • Fire Science and Engineering
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    • v.31 no.3
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    • pp.97-105
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    • 2017
  • Because asphalt is a solid at normal temperature and is not a hazardous material as stipulated in the Safety Management Act on Hazardous Materials, it is often recognized as having no risk of fire or explosion. On the other hand, it is as dangerous as flammable liquid because it is heated to $170-180^{\circ}C$ and stored in a storage tank. This study analyzed the risk of fire and explosion during the storage and handling of asphalt and the actual conditions of asphalt regulations by fire service organizations. Moreover, this study analyzed the domestic case of explosions in the production process of asphalt concrete (ASCON) and domestic and foreign cases of asphalt storage tank explosions. The analysis suggested that unlike Japan, Korea has no asphalt regulations in fire service organizations. Explosions can occur when ignition is delayed after fuel is sprayed on the dryer drum burner of the aggregates during the production of ASCON. A physical explosion can occur in the storage tank when environmental purification facilities suddenly work strongly to remove air pollutants or bad smells during the heating of asphalt in an asphalt storage tank. In addition, explosions can occur when fires such as welding is performed in the asphalt storage tank.

A Study on User Needs for Public Access to the Supreme Court Library of Korea (법원도서관의 대국민서비스 개방에 따른 이용자요구 분석연구)

  • Kwak, Seung-Jin;Noh, Younghee
    • Journal of the Korean Society for Library and Information Science
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    • v.52 no.3
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    • pp.215-246
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    • 2018
  • As a law library representing the Department of Justice, the Supreme Court Library of Korea collects various domestic and foreign legal information and aims to become more publicly accessible. In 2018, after its relocation to Goyang, Korea, the library has initiated check-out services to citizens and is currently developing a plan to provide services in the legal field. In this study, we have assessed the current situation at the Supreme Court Library as well as public libraries in Goyang. Furthermore, we have surveyed future users and legal experts to formulate a proposal for optimal literary composition and spatial composition, as well as library arrangement. Survey participants expected extensive provision of legal information regarding legal professions and the general public. There was a significant difference in opinion between legal experts and users with respect to resources for the public; general citizens desire more materials related to general topics whereas legal experts expect more law-specific resources such as information regarding judicial precedents and court decisions, research articles. Furthermore, 80% of users expressed interest in utilizing the library; therefore, active efforts to improve its facilities will lead to successful operations of the library.

Comparative Evaluation of Washing Methods of Chinese Cabbages for Eliminating the Parasite Eggs in the Preparing Kimchi (김치 제조시 기생충란 제거를 위한 배추 세척방법의 비교평가)

  • Choi, In-Uk;Youn, Young-Nam;Yu, Yong-Man;Choi, Min-Ho;Lee, Young-Ha
    • Journal of Food Hygiene and Safety
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    • v.22 no.3
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    • pp.192-198
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    • 2007
  • Kimchi is one of the representative traditional foods in Korea, which is recognized as a kind of wellbeing foodstuffs. However, as increasing foreign-made Kimchi, its safety as food is at the forefront of public health concerns. We analyzed the washing methods of Chinese cabbages, which are the main materials in Kimchi, to prevent parasite contamination during preparing it. To decontaminate parasite eggs from Chinese cabbages, discard the discolored outer leaves from cabbages, spread the space of leaves with fingers and rinse more than 3 separate water tanks with streaming water (velocity more than 0.8m/sec). At each tank, Chinese cabbages were rinsed with more than 3 strokes upward and downward within the streaming water followed by moving back and forth more than 3 times, with 20cm in height and 30cm in width, respectively. Decontamination efficiency increased higher in parallel with streaming velocity of water, and with adding the vegetable detergent to the tank water.

Statistical Properties of Material Strength of Concrete, Re-Bar and Strand Used in Domestic Construction Site (국내 현장의 콘크리트, 철근 및 강연선 재료 강도에 대한 통계 특성 분석)

  • Paik, In-Yeol;Shim, Chang-Su;Chung, Young-Soo;Sang, Hee-Jung
    • Journal of the Korea Concrete Institute
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    • v.23 no.4
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    • pp.421-430
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    • 2011
  • As a fundamental study to introduce the reliability-based design code, a statistical study is conducted for the material strength data collected from domestic construction sites. In order to develop a rational design code based on statistics and reliability theory, it is essential to obtain the statistical properties of material strength. Material strength data for concrete, reinforcing bars, and prestressing strands which are used in domestic construction sites are collected and statistically analyzed. Then, the statistical properties are compared with those used in the process of the reliability-based calibration of internationally leading design codes. The statistical properties of the domestic data are such that the bias factor is relatively uniform between 1.13 and 1.20 and the coefficient of variation is below 0.10. Reinforcing bar data show difference among different manufacturers but there is not much difference among re-bar diameters. In the case of tendons, which are high strength materials, both of the domestic and foreign data show smaller values of the bias factor and the coefficient of variation than those of concrete and re-bar. Statistical distribution of all the material strength can be properly assumed as normal, log-normal, or Gumbel distribution after analyzing the classified data by individual construction site and manufacturer rather than the mixed data obtained from different sources in order to express the individual distribution of each structure.

Regional Structure and Locational Characteristics of Najin-Seonbong Economic and Trade Zone (나진-선봉 경제 무역 지대의 입지특성과 지역구조)

  • Lee, Ki-Suk;Lee, Ock-Hee;Choe, Han-Sung;Ahn, Jae-Seob;Nan, Ying
    • Journal of the Korean Geographical Society
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    • v.37 no.4
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    • pp.293-316
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    • 2002
  • This study aims to identify changes that have occurred in the regional structure and locational characteristics of the Najin-Seonbong Economic and Trade Zone established in North Korea in 1991. In order to analyze land use patterns as variables of change in the regional structure, an field trip data, satellite imagery and other materials about the region are examined. In terms of its location as a major regional transit hub, the Najin-seonbong Economic and Trade Zone has not been supported by the required infrastructural developments and the establishment of the export processing zones has exposed the lack of vital links with local networks and industry. Thus, despite the fact that the local government has made a lot of effort in attracting foreign investment over the past decade, little progress has been made and the region has not changed. By and large, its operational efficiency and potential for development as a major export processing zone has been relatively limited. In the long w, prospects for the region's emergence as a major economic player will depend on the North Korean Govemment's policy in tackling the various infrastructural deficiencies.

Burial Age and Flooding-origin Characteristics of Coastal Deposits at Gwangseungri, Gochanggun, Korea (고창군 광승리 연안 퇴적층의 퇴적 시기와 범람 기원 특성)

  • Kim, Jong Yeon;Yang, Dong Yoon;Shin, Won Jeong
    • Journal of the Korean earth science society
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    • v.36 no.3
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    • pp.222-235
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    • 2015
  • Samples were collected from both places including the coastal area within the height of 5 m above the mean sea level (msl) (DH) and the top of the coastal terrace of 10-15 m msl (KS) high in Gwangseungri, Gochanggun, Korea. To find the origin of the deposit in the coastal area, granulometric analysis and geochemical analysis were performed. The result showed that the DH samples were originated from the reddish soils overlaying weathered bedrock which presented gradual change of chemical composition from the bottom toward the top. Clay minerals were found from the DH samples. These results concluded that the DH samples were found as in-situ weathered materials. The KS samples were originated from the soil layer covering gravel layer at the foot slope of the hill along the coast. The KS samples contained different chemical compositions from the DH. It is inferred that some of this layer was disturbed or experienced the influx of foreign material. The particle size of the KS samples was different from those found on the beach. The particle size of lower parts of KS site was finer than that on the beach, but the particle size of middle part of the site was coarser than that on the beach. The sorting of the KS site was poorer than that on the beach. Thus, it is inferred that some parts of the layer were formed by short-lived high energy event rather than sustained and continuous action of tidal currents and/or waves. Analysis using an optically stimulated luminescence (OSL) method showed that the burial age of samples from KS site were found 0.65-0.71 ka. Though the characteristics of the sediment layer and forming event in this area should be further studied, it can be inferred that this sedimentary layer formed by coastal flooding with storm.

Development and application of Technology.Home Economics Teaching-Learning Lesson Plan on Clothing Lifes to Raise youth's awareness of traditional clothing culture (청소년의 전통 의생활 문화 인식 고취를 위한 가정과 교수.학습 과정안 개발 및 적용 -고등학교 1학년 '가정생활 문화의 변화' 단원을 중심으로-)

  • Ban, Youn-Ja;Kim, Nam-Eun;Lee, Hye-Ja
    • Journal of Korean Home Economics Education Association
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    • v.23 no.4
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    • pp.1-17
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    • 2011
  • We investigated youth's awareness of traditional clothing culture in order to promote it, and we developed and applied the Teaching-Learning process related to clothing life chapters. We analyzed 12 types of high school freshman textbooks under the revised $7^{th}$ national curriculum and selected 5 major subjects of learning 'traditional culture', 'History of Han-bok', 'colors of Han-bok', 'pattern & material of Han-bok', 'globalization of Han-bok' related to 'change of home life & culture' chapter. Also we developed 5-period Teaching-Learning Lesson Plan and 48-teaching materials(22 for students, 22 - for classes, 4 for teachers) and applied it to usual classes. The mean score of youth's awareness of traditional clothing culture in the post-test was significantly higher than in the pre-test. We concluded it was highly efficient in the youth's awareness of traditional clothing culture as right awareness about traditional clothing life culture, acceptance of foreign culture, positive attitude in traditional culture. Awareness about traditional clothing culture education was improved significantly, so we recognized importance of traditional culture education through it. We suggest that various themes on traditional culture should be developed and more reinforced. Also we need various traditional culture succession research as field of food life, house life and study Korea's cultural heritage.

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A Study on Flame Retardant Performance of Vertical Blind and Roll Screen (버티칼 브라인드와 롤 스크린의 방염성능 유지에 관한 연구)

  • Jeong, Hyun Gyu;Cho, Woncheol;Lee, Tae Sik
    • Journal of Korean Society of societal Security
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    • v.3 no.2
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    • pp.41-46
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    • 2010
  • This study focuses on two points. First, I have examined the difference on combustion between flame-retardant and non flame-retardant products including vertical blinds and roll screens that are widely used as a substitute for fabric curtains. The second point is to see how long flame-retardant goods can be durable, that is, flame retardant durability after washing in liquid. the experiment on the flame-retardant ability before and after washing of vertical blinds and roll screens that have been used for a long time in fire protection construct. Comparing and analyzing domestic and foreign laws on flame-retardant after the experiment on durability of these products. I aim to draw necessity for increased application of internal laws and regulations on flame-retardant and show how to improve the point at issue. According to the result, clear differences in performance and safety were observed between flame-retardant and non flame-retardant products. flame-retardant materials can prevent things from fire spread without igniting but melting when they've met flame and burnt, In contrast, non flame-retardant material for experiment which size is 120cm long takes less than 3 minutes only to be completely destroyed by fire. However, it was expected for flame-retardant durability of flame-retardant blinds which are not washable to decrease flame-retardant durability after being washed with water, there was no sharp difference. so it is demonstrated that flame-retardant blinds can keep flame-retardant durability. accordingly through the strict course of product we are concerned about keeping durability.

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An Experimental Study on the Automobile Engine Room Fire Using the Extinguishing Agents (소화약제를 이용한 자동차 엔진룸 화재 실험에 관한 연구)

  • Han, Yong-Taek;Kim, Dong-Ho;Kwon, Sung-Pil
    • Fire Science and Engineering
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    • v.28 no.4
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    • pp.1-7
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    • 2014
  • Several complex devices and equipments are installed in the car's engine room, including various kind of oils or other flammable materials. So re-ignition is very likely to take place in it. In addition, it is restrictive for the driver or the occupant to open the bonnet and to spray the fire extinguisher in the engine room due to the high possibility of explosion. Therefore, a fire extinguishing system, which can detect a fire and inject the fire extinguishing agent to extinguish it, and fire extinguishing agents including HFC-227ea, which can stand the high temperature within the engine room and hold the viscosity sufficient to keep it in the kind of foam, were developed and tested. And the suffocation effect and the cooling effect come from the fire extinguishing principle of the foam fire extinguishing agent and the inhibiter catalyst effect come from the one of HFC-227ea was led simultaneously, and fire extinguishing agents without the secondary damage caused by residuals after the fire extinguishment like a case of the powder fire extinguishing agent, were developed. And experiments using a vehicle collision after the discharge is complete, foreign material can be removed without extinguishing the advantage that experimental results obtained.

Measurement of Crack Width of Pavements Using Image Processing (이미지프로세싱을 이용한 도로포장의 균열폭 측정에 관한 연구)

  • Ko, Ji-Hoon;Suh, Young-Chan
    • International Journal of Highway Engineering
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    • v.4 no.2 s.12
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    • pp.33-42
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    • 2002
  • The cracks in the pavements result from drying shrinkage, temperature change, repeated traffic loadings and so on. The reduction of soil support, spatting and many local failures are caused by water and incompressible foreign materials infiltrated into the cracks. In order to reduce this kind of problems the crack width must be controlled and managed by the accurate measurement. The current method is a visual survey using a microscope, which requires traffic blocking. The purpose of this study is to find the best condition to measure accurate crack width using automated pavement condition survey equipment running at the similar speed as other vehicles. In this study pavement surfaces are filmed on an enlarged scale by the camera with a zoom lens, and then the proper focal distance is determined according to the crack width through a pilot survey. The conditions for measurement of the accurate crack width using the image processing technique are suggested by comparing crack widths surveyed using a microscope in the field with those computed by various factors in the image processing program, STADI-2. In conclusion, the camera with a focal distance of 75m could detect crack range of 0.5mm$\sim$1.2mm In width with an accuracy of 80% for CRCP. The camera with a focal distance of 12.5mm could detect crack range of 1.8mm$\sim$3.3mm in width with an accuracy of 90% for asphalt pavement.

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