• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2010.04a
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• pp.366-370
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• 2010

허니컴 코아 구조는 강성과 강도가 뛰어나 건축물의 내장재 등 많은 분야에서 활용되고 있다. 특히 허니컴 종이는 생산 단가가 낮으며 재활용이 가능하여 환경오염을 일으키지 않는다. 그러나, 종이 재료의 특성상 화재에 취약하여 난연화 할 필요가 있다. 본 연구에서는 방화문 내장재 및 포장재에 보편적으로 사용되는 허니컴 중이의 난연 처리 방법에 따른 난연 성능을 평가하였다. 연구 대상으로는 난연종이로 제작된 허니컴과 실험실에서 제작된 방염 필름을 부착한 허니컴, 난연제 함침을 통해 제작된 허니컴, 난연제 함침 후 방염 필름을 부착한 허니컴을 포함해 총 4종에 관한 난연 성능을 비교하였다. 그 결과, 난연제를 함침한 허니컴 종이가 가장 낮은 열방출률을 보여주었으며, 방염 필름 부착은 착화 시간 지연에는 효과가 있었으나 열방출률에 부정적인 영향을 미치는 것으로 확인되었다.

• Fire Science and Engineering
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• v.25 no.6
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• pp.190-195
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• 2011

Effects of ethylene-propylene diene monomer (EPDM)/polypropylene (PP), zinc oxide, stearic acid, and clay on the combustive properties based on EPDM/PP were investigated. The EPDM/PP/clay nanocomposites was compounded to prepare specimen for combustive analysis by cone calorimeter (ISO 5660-1). It was found that the combustive properties in the nanocomposites decreased due to the fire resistance compared with unfilld EDPM/PP. The nanocomposites showed the lower peak heat release rate (PHRR) than that of virgin EPDM/PP, while stearic acid for softening ruber increased the mean heat release rate (MHRR) by itself, combustible.

• 대한방사선방어학회:학술대회논문집
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• 2009.11a
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• pp.136-137
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• 2009

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2002.11a
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• pp.132-138
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• 2002

• Journal of the Korean Vacuum Society
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• v.10 no.2
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• pp.164-172
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• 2001

We measured the pumpdown curves of an A5083 vacuum chamber and analyzed the outgassing in terms of desorption energies of water. The outgassing curves follow a ~$t^{-1.15}$ behavior before bakeout, which can be described by the first-order desorption of water molecules in the oxide layer. Analysis of the curves reveals that there exist several adsorption sites on the surface for water in the pressure range of ~$10^{-5}\;-\;10^{ -8}$Torr. Measurements utilizing the throughput method show that the room temperature outgassing rate is ~1{\times}10^{-13}$ Torr $\ell$/s $\textrm{cm}^2$ after 24 - h bakeout at $100^{\circ}C$.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.24 no.11
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• pp.1519-1527
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• 2020

AGeneral radiation measuring devices have been developed in the form of spatial dose rate detection devices that measure dose rates to radioactive contaminant and 2D or 3D imaging devices for radioactive contamination information. Each of these radiation detection techniques has advantages. The advantages of both detection devices are necessary to minimize personal injury and rapid decontamination in the area of a radioactive accident. In this paper, we proposed a technique that can measure the dose rate and direction information about the radioactive pollutant source in real time using a detection sensor, a rotating body, and a directional shield for radioactive pollutant detection. The rotational-based detection device is configured to check the dose rate and direction using the location information of the rotator and measurement value. We proposed a measurement technique for vertical and horizontal directions through multiple holes. It was confirmed that the measurement error for direction information was less than 1% when detected in the horizontal direction.

• Journal of the Korean Society for Railway
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• v.13 no.5
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• pp.481-487
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• 2010

A room scale fire test was done for interior materials from a subway vehicle installed within an ISO 9705 fire test room. The interior materials are the old ones which were made before the new fire safety guideline of subway vehicles. The output of ignition burner was increased in controlled steps to CEN/TS 45545-1. The objectives of this interior fire test are to assess the fire performance in terms of ignition and flame spread on interior lining materials and to provide data on an enclosure fires involving subway vehicle interior materials that grow to flashover. Temperatures, heat flux and heat release rate variations verse time of the test are measured. Heat release rate is compared with that of calculated by modified flaming area based summation method. These test results will be used for verification of CFD fire simulation of full subway vehicle.

• Fire Science and Engineering
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• v.25 no.3
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• pp.57-62
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• 2011

The combustion characteristic was evaluated for Pinus densiflora, used as a building material in Hanok, which were treated with two different flame retardant method. The specimen was brushed with flame retardant liquid two or three times and then let the specimen dehydrated during 24 h for spreaded treating. And the other specimen was soaked in the liquid for 72 h. The test methods were inflammability test using meker burner and heat release rate test using cone calorimeter. As a result for the tests, flame retardant treated specimens met the requirements of the inflammability and the spreaded treated method was more efficient than immersed method. The spreaded treated specimen had lower combustive properties than immersed specimen in TTI (time to ignition), PHRR (peak heat release rate), MLR (mass loss rate) and THR (total heat release).

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• v.y2005m4
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• pp.259-264
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• 2005

Measurements of heat release are very important for controling combustion instabilities, which are closely connected with combustion instabilities. $OH^{\ast}$ images were acquired through a ICCD in this study, which were in use as indicating index of the reacting region, global and local heat release rate in the lean premixed combustion. The objectives of this study are to see the effect of equivalence ratio on global heat release rate and local Rayleigh index distribution. The local Rayleigh index distribution was acquired by information from central section of flame. This information was from the line-of-sight images which were inverted by the Abel de-convolution. In each condition, the mean value of heat release increased exponentially with equivalence for a periodic time. Local Rayleigh index distribution cleary showed the region of amplifying or damping the combustion instability as the equivalence ratio increased. This could provide an insight on the region of combustion instability and the structure of flames on the equivalence ratio.

• Korean Journal of Veterinary Research
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• v.6 no.1
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• pp.24-30
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• 1966

In order to observe the effect of the injected radioactive iodine-$I^{131}$ on the uptake in thyroid of normal male guinea pigs and P.B.$I^{131}$ conversion ratio of $I^{131}$ in serum, 24 matured male guinea pigs were divided in 4 groups and $35{\mu}c$, $70{\mu}c$, $140{\mu}c$ and $280{\mu}c$ per kg of body weight respectively were injected subcutaneously. 1. The uptake rates of radioactveiodine-$I^{131}$ by external counts of thyroidal uptake reached the maximum level of uptake in 24 hours after injection. 2. As the injected amount increases, the uptake rates of maximum levels and release rate were increased. 3. Uptake rate in the removed thyroid have shown no statistical in the $35{\mu}c$ and $70{\mu}c$ groups of injected guinea pigs. 4. There was no statistical significance in $140{\mu}c$ and $280{\mu}c$ groups of injected guinea pigs. 5. P.B.$I^{131}$ conversion ratio of $I^{131}$ in serum was not in proportion to injected amounts: 61.0%(35), 70.2%(70), 75.3%(140) and 64.8%(280).