• Title/Summary/Keyword: Reappearance experiments

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Study of the Tracking Fire Risk by Dust Resistivity of Pens (축사별 먼지 저항률에 따른 트래킹화재 위험성에 관한 연구)

  • Park, Kwang-Muk;Bang, Sun-Bae;Kim, Jae-Hyun;Park, Jin-Yeong
    • Fire Science and Engineering
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    • v.30 no.6
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    • pp.99-104
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    • 2016
  • In animal and plant facilities, dust samples were collected from cattle sheds, pigsties and hen-houses, which have high proportion of electrical fires. The samples were diluted in distilled water and water resistivity was measured. Current measurements and tracking reappearance experiments were conducted using distilled water with dust samples. The analysis results were obtained to track the fire risks according to the dust resistivity. The highest value was the dust from cattle sheds followed in order by the dust of pigsties and hen-houses. In experiments measuring the temperature change and RMS current, the lower resistivity of water showed a significant trend of temperature and high amperage. In the tracking reappearance experiment with the lower resistivity water, the tracking speed was fast and the ignition time was shortened. This study investigated why each dust resistivity shows different results.

A Study on the Characteristics of Smouldering Fire by Cigarette Fires (담뱃불에 의한 훈소화재 특성에 관한 연구)

  • Hwang, T.Y.;Lee, C.W.;Choi, D.M.
    • Journal of Korean Institute of Fire Investigation
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    • v.11 no.1
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    • pp.111-126
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    • 2007
  • In this study, we drew identification techniques of cigarette fires through the cases analyses of the combustion characteristics, the combustion time, the combustion temperature, the combustion test of smoldering materials and the reappearance experiments of cigarette fires. To initiate fires by cigarette fire, the conditions of oxygen supply, combustible materials must be satisfied. On the other hand, fires were not spreaded easily under the insufficient combustion conditions.

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Development of Acid Rain Model Instrument and Its Application in Environmental Education

  • Ma, Chang-Jin;Shin, Eun-Sang
    • Asian Journal of Atmospheric Environment
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    • v.9 no.3
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    • pp.222-227
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    • 2015
  • The environmental education with ideal teaching tools (e.g., a small-scaled experimental kit) is essential for raising the public's, especially student's, awareness of many environmental issues. This study was undertaken to develop a do-it-yourself model instrument of acid rain and estimating its applicability to the environmental education. Our novel model tool consists of a body (17 cm width, 6 cm depth, and 17 cm height), an acid gas injector, acid four rain reservoirs, and a drop supply pump. An alternative model instrument that can be more readily assembled was also suggested. Based on our novel approach, we carried out several model experiments with educatees (i.e., high school and college students, and adults). The results of questionnaires indicated that educatees achieved a very deep understanding of acid rain through an experienced model experiment. A 77 to 89% of educatees experienced the reappearance experiment of acid rain by our model instrument felt that it was very useful as a teaching tool of environmental education.

A Study of the Safe Measure Industrial Explosives (화약산업의 발파안전대책 - 소음진동 및 안전거리 설정을 중심으로 -)

  • Ahn Myung Seok
    • Explosives and Blasting
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    • v.9 no.4
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    • pp.13-21
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    • 1991
  • This study is concerned with the disasters that occure in the field of industrial explosives and analyzed by two side the disaster of the manufacturing factory and that of the field, and is studied about the safety and the countermeasure. The industrial explosives accidents occure just accidentaly and unforeseeable, and reappearance experiments are more difficult. The 3E of J.H. Harvey was applied in this study to establish the counter measure of preventation of accidents, overcoming these restricted factores. As a method of technical safety countermeasures. The blasting vibration formula which had been conformed from the Seoul Subway Construction work during 1980-1984 year, was uilized, and, using the formula $V=Kw^{0.5}D^{-1.5}$ for the gneiss which is widely distributed in Pusan area, an index of the minimum and maximum amount of gun powder, to be used according to safety distance was made, and it helped the gun powder managing technician's practical business. During the fore work discharging, the safety distances of felling were theoretically established based on the writer ${\diagdown}s$ experiences of more than 10 years on this field.

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Study on the Electrical Safety Management Method through the Electrical Characteristic Analysis of LED Lamps (LED 램프의 특성 분석을 통한 전기안전 관리 방안에 관한 연구)

  • Lee, Ki-Yeon;Moon, Hyun-Wook;Kim, Dong-Woo;Lim, Young-Bea;Ryu, In-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.11
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    • pp.1931-1936
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    • 2016
  • In this paper, we analyzed causes of accidents that recently increased in the illegal and defective LED lamps. They were analyzed by the electrical characteristics calculation and reappearance experiments. The causes of the accidents were analyzed from the circuit affected by the variation of voltage, current and power by harmonics. We drew a conclusion for electrical safety in illegal or degraded LED lamps from the analysis result. The management factors for electrical safety in LED lamps were harmonics, reactive power and power factor. It is possible to secure the electrical safety through monitoring of power factor in failure products and available in smart meters or smart distribution boards.

A Study on the Fire Case Analysis of Air Conditioner and Preventive Measures (에어컨 화재사례 분석 및 예방대책에 관한 연구)

  • Kim, Dong-Ook;Lee, Ki-Yeon;Kim, Dong-Woo;Gil, Hyung-Jun;Bang, Sun-Bae;Chung, Young-Sik
    • Fire Science and Engineering
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    • v.27 no.2
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    • pp.40-45
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    • 2013
  • In recent years, many electrical fires have occurred due to complex causes. Therefore, products are required to make with scientific design considering electrical, thermal, mechanical and environmental influences. Disasters can cause losses of life and property with fall in confidence of countries and companies. And demands for safe product have been increased by reason of recent deregulation followed by limitless competition. It is necessary to design safe product in order to improve corporate image and strengthen international competitive power. This paper addresses electrical fire case of air conditioner. The use of air conditioner have recently increased as a result of global warming. The aim of this study is to provide safety design and fire prevention measures of air conditioner through cause analysis and reappearance experiments.

A Study on the Surface Phenomena of Re-creational Gilt Layer by Conditions of Heat Treatment (열처리 조건에 따른 재현 도금층의 표면현상 연구)

  • Yang, Seok-Woo;Kim, Soo-Ki
    • Journal of Conservation Science
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    • v.28 no.1
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    • pp.29-37
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    • 2012
  • This study discusses a mercury amalgam gilding technique and examines how the color, surface and section of the gilt layer changes as the condition of heat treatment with mercury amalgam gilt object is changed. Some previous studies have mentioned reasons for various colors on gilt bronze artifacts depending on gilding manufacture and environment. However, reason for reddish color with gold on the artifacts' surface brought on high temperature corrosion has yet to be discussed and analyzed. A methodology was found in representing the mercury amalgam gilding technique and heat treatment test. According to the result of the heat treatment test, in the conditions of higher temperature and longer time, the oxidized layer on the gilt layer was distributed more widely and in the part when the oxide layer was eliminated, the gilt layer with a reddish color was observed. Moreover, in the surface observation of the specimen on which yellow and reddish colors were agitated, the changing aspects of its surface condition differed by colors. When investigated the section, it was observed that the void density and size became larger. After a test, the surface components changed; the temperature of heat treatment increased, component ratio of Hg and Au decreased gradually but component ratio of Cu increased. In regard to the gilt layer, as the time was longer and the temperature became higher for the heat treatment, the component ratio of Au and Cu by layers tended to change in inverse proportion. It is concluded that gilding techniques and the burial environment can make a difference in the surface color of the gilt layer on the gilt bronze artifacts, the high temperature corrosion that occurs by heat after they are manufactured is also one of the factors that affects their surface color.