• Fire Science and Engineering
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• v.29 no.1
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• pp.12-18
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• 2015

This study has conducted an experiment of comparing the flame resistant performance and combustion characteristics according to flame resistant treatment using the Cypress Luba and particle board that is commonly used for interior decoration and furniture. As a result of testing the flame resistant performance of Cypress Luba, the Cypress Luba injected with flame resistant resin using the vacuum pressure treatment has shown to have better performances (carbonized area 9.55% and carbonized length 22.91%) than the Cypress Luba treated with flame resistant coating having rubberized plastic components on its surface. For particle board, the specimen attached with fireproof film was identified to be better (carbonized area 40.10% and carbonized length 43.40%) than the specimen with non-fireproof film. For the results of combustion characteristics using the Cone Calorimeter, the specimen treated with flame resistant coating on the surface had faster ignition than the Cypress Luba injected with fire resistant resin using vacuum pressure treatment, and in the total release of calories, the Cypress Luba injected with fire resistant resin using vacuum pressure had $68.2MJ/m^2$, and the specimen treated with fire resistant coating on the surface had $111.52MJ/m^2$. For the particle board, the ignition time had a little difference but in the total release of calories, the specimen attached with fireproof film had $90.1MJ/m^2$ and the specimen with non-fireproof film had $107.6MJ/m^2$.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1727-1736
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• 1991

본 연구에서는 자체 제작된 헬름홀쯔형 맥동 연소기를 이용하여 작동원리와 연소특성을 조사함으로써 맥동연소현상을 물리적으로 이해하는 것이다. 주기적 화염 의 직접가시화, 연소장의 시간평균 온도 및 농도분포, 변동압력의 크기와 공기흡입량 을 조사함으로써 맥동에 영향을 미치는 요인이 무엇인지 그리고 이것이 어떠한 변화를 야기시키는가를 살펴보고자 한다. 이렇게 얻어진 결과의 종합을 통해 장치의 형상이 결정된 일반적인 맥동연소기가 자발적인 상태에서 작동될 때 작동결정인자가 무엇인가 를 알수가 있을 것으로 사료된다.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.1
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• pp.132-137
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• 2002

Recently, impinging spray is used for atomization of diesel engine, but it bring on adhesion of fuel. Therefore, we studied about droplet behavior on high temperature plate changing the size of droplet, surface temperatures, and surface roughness of plate. In this study, We studied to confirm experimentally about mechanism of evaporation and ignition process of single fuel droplet. We observed evaporation time, evaporation appearance and ignition delay time by the photopraphs of 8mm video camera. Experimental results are summarized as follows: 1. The boiling point of fuel affect a evaporation and ignition process. 2. The surface roughness affect a evaporation time. 3. The ignition delay time relate to evaporation characteristic.

• Journal of the korean Society of Automotive Engineers
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• v.17 no.5
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• pp.1-8
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• 1995

전산유체 해법의 내연기관 3차원 해석에 대한 최근 연구 동향에 대해 소개하였다. 난류유동 해석은 아직 정확성과 신뢰도 면에서 많은 연구가 필요하지만 현재의 상태에서도 직관, 경험, 실험 측정에 의해 파악하기 어렵거나 많은 비용과 시간이 요구되는 부분을 보완해 줄 수 있는 도구로서 인정받고 있다. 연소해석 부분은 현상 자체가 유동, 연소, 분무, 열전달등이 복합적으로 작용하는 어려운 문제로서 공학계산의 가장 첨단 분야 중의 하나라 할 수 있다. 현재 관련 모델로서 스파크 점화기관의 점화 및 화염전파, 배기가스 생성 과정과 디젤기관의 압축착화, 예혼합 및 확산 연소, 매연 등의 생성과정에 대한 모델 개발과 검증이 활발히 이루어지고 있다. 일부 발표된 논문 결과들은 이와 같은 방법이 엔진의 주요 연소 특성을 재현하는데에 성공적으로 활용될 수 있음을 보여주고 있다.

• 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.

• Journal of the Korean Chemical Society
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• v.39 no.1
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• pp.23-28
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• 1995

Differential-pulse cathodic stripping voltammetry was applied to the Sn(II)-cupferron complex in 0.1 M acetate buffer solution (pH 4.20). Effects of solution pH, ligand concentration, accumulation potential, and accumulation time on the reduction peak current for the adsorptive complex of Sn(II)-cupferron were investigated. Interferences by other metal cations that affected on reduction peak current were also discussed. The detection limit was 3.1${\times}$10-9 M (0.37 ppb) of Sn(II) with 60 seconds accumulation time. The relative standard deviation (n=8) for 5${\times}$10-8 M Sn(II) was 3.0%.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.5
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• pp.524-533
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• 2008

Industrial wastewater generated in the electroplating and metal finishing industries typically contain toxic free and complex metal cyanide with various heavy metals. Alkaline chlorination, the normal treatment method destroys only free cyanide, not complex metal cyanide. A novel treatment method has been developed which destroys both free and complex metal cyanide as compared with Practical Plant(I). Prior to the removal of complex metal cyanide by Fe/Zn coprecipitation and removal of others(Cu, Ni), Chromium is reduced from the hexavalent to the trivalent form by Sodium bisulfite(NaHSO$_3$), followed by alkaline-chlorination for the cyanide destruction. The maximum removal efficiency of chromium by reduction was found to be 99.92% under pH 2.0, ORP 250 mV for 0.5 hours. The removal efficiency of complex metal cyanide was max. 98.24%(residual CN: 4.50 mg/L) in pH 9.5, 240 rpm with 3.0 $\times$ 10$^{-4}$ mol of FeSO$_4$/ZnCl$_2$ for 0.5 hours. The removal efficiency of Cu, Ni using both hydroxide and sulfide precipitation was found to be max. 99.9% as Cu in 3.0 mol of Na$_2$S and 93.86% as Ni in 4.0 mol of Na$_2$S under pH 9.0$\sim$10.0, 240 rpm for 0.5 hours. The concentration of residual CN by alkaline-chlorination was 0.21 mg/L(removal efficiencies: 95.33%) under the following conditions; 1st Oxidation : pH 10.0, ORP 350 mV, reaction time 0.5 hours, 2nd Oxidation : pH 8.0, ORP 650 mV, reaction time 0.5 hours. It is important to note that the removal of free and complex metal cyanide from the electroplating wastewater should be employed by chromium reduction, Fe/Zn coprecipitation and, sulfide precipitation, followed by alkaline-chlorination for the Korean permissible limit of wastewater discharge, where the better results could be found as compared to the preceding paper as indicated in practical treatment(I).

• Applied Chemistry for Engineering
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• v.25 no.5
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• pp.481-486
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• 2014

This study was performed to test combustive properties of medium density fibreboard (MDF) plates treated with piperazinomethyl-bis-phosphonic acid (PIPEABP), methylpiperazinomethyl-bis-phosphonic acid (MPIPEABP), and N,N-dimethylethylenediaminomethyl-bis-phosphonic acid (MDEDAP). MDF specimens were painted three times with 15 wt% solution of the alkylenediaminoalkyl-bis-phosphonic acids at room temperature. After drying specimen treated with chemicals, combustive properties were examined using the cone calorimeter (ISO 5660-1). As a result, combustion-retardation properties increased due to the treatment of bare MDF with alkylenediaminoalkyl-bis-phosphonic acid solution. Especially, the specimens treated with chemicals showed the ignition (TTI) (148 s~116 s) was retarded and the flameout (Tf) (633 s~529 s) time increased, while the total heat release rate (THRR) (61.1~67.0) $MJ/m^2$ was lowered than those of using virgin plate by reducing the burnig rate. Compared with virgin MDF plate, the specimens treated with the alkylenediaminoalkyl-bis-phosphonic acids showed low combustive properties. However the specimens treated with bis-(dimethylaminomethyl) phosphinic acid (DMDP) showed the higher peak heat release rate (PHRR) ($185.08kW/m^2$) than that of the virgin plate.

• Fire Science and Engineering
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• v.27 no.6
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• pp.70-76
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• 2013

Four kinds of new piperazinomethyl-bis-phosphonic acid $M^{n+}$ ($PIPEABPM^{n+}$) were synthesized and their combustive properties of Pinus rigida plates treated with $PIPEABPM^{n+}$ were tested. Pinus rigida specimens were painted in three times with 15 wt% $PIPEABPM^{n+}$solutions at the room temperature. After drying specimen treated with chemicals, com-bustive properties were examined by the cone calorimeter (ISO 5660-1). As a result, the combustion-retardation proper-ties were increased by due to the treated $PIPEABPM^{n+}$ solutions in the virgin pinus rigida. Especially, the specimens treated with $PIPEABPM^{n+}$ showed both the lower peak heat release rate ($HRR_{peak}$) (162.02~145.36) s and total heat release rate (THRR) (73.0~67.4) $MJ/m^2$ than those of virgin piperazinomethyl-bis-phosphonic acid (PIPEABP)-plate. Compared with virgin PIPEABP-plate, the specimens treated with the $PIPEABPM^{n+}$ showed low combustive properties. However the specimens treated with $PIPEABPM^{n+}$ showed both the shorter time to ignition (TTI) (67~23) s and the time to flameout (Tf) (472~433) s than those of virgin PIPEABP-plate by increasing the thermal conductivity.

• Elastomers and Composites
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• v.49 no.1
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• pp.59-65
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• 2014

In this study, in order to complete curing reaction of the molding compound comprising an epoxy/anhydride at $71^{\circ}C$ for 40 hours, metal coordination complexes such as cobalt (II) acetylacetonate, potassium acetylacetonate, iron (III) acetylacetonate and chromium (III) octoate as a catalyst were applied to the epoxy/anhydride compounds respectively. The weight ratio of an epoxy part/an anhydride part was adjusted to improve the mechanical properties of the molding compound. According to the experimental results, an epoxy/anhydride compound containing chromium (III) octoate showed a high conversion at $71^{\circ}C$ for 40 hours as well as a proper processability at room temperature among the several metal coordination complexes. For the mechanical properties of the cured epoxy/anhydride compound, the compounds containing weight ratio from 0.9/1 to 0.5/1 of the epoxy part/anhydride part with chromium (III) octoate showed the high flexural strength, and higher compressive strength was shown with increasing of the hardener part.