• Journal of the Korean Chemical Society
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• v.30 no.6
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• pp.516-520
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• 1986

This study is related to reactivity of dioxygen bridged palladium complexes having ${\pi}$-allyl ligands. In this case, new dioxygen bridged palladium complexes were prepared using superoxide ion$(O_2^-)$ as an oxygen source. Reactions of the dioxygen palladium complexes prepared in the study were examined in order to clarify the nature of the coordinated dioxygen. Treatments of a solution of the dioxygen bridged palladium complexes in benzene by water, methanol and acetic acid gave hydrogen peroxide $(H_2O_2)$ as hydroxy-, methoxy-, and acetoxybridged palladium complexes, respectively. The dioxygen bridged palladium complexes reacted also with substitution phenols of salicylaldehyde, 8-hydroxyquinoline and active methylenes of acetylacetone, dimethyl malonate to afford mononuclear complexes of palladium and hydrogen peroxide. The results suggest that dioxygen is coordinated as peroxo $(O_2^{2-})$ in the complexes and behaves as a strong base.

• Proceedings of the Korean Society for Emotion and Sensibility Conference
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• 2003.05a
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• pp.55-64
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• 2003

본 연구에서는 노인의 신체 특성에 적합한 고기능성 구두를 개발하기 위하여 한국인에 적합한 리스트를 근간으로 하여 발에 편안한 착화감을 줄 수 있는 노인화를 개발하였다. 본 연구의 핵심 연구분야인 제화 족형 설계·제작은 제화공정에서 가장 중요한 부분으로 본 연구진에 의해 수년간에 걸친 인체 족 측정 및 체계적인 족형설계 과정을 거쳐 제작된 족형을 통한 수차례의 착화시험에 의해 마련된 표준 족형을 근간으로 최종 제작되었다. 이러한 결과를 바탕으로 새로 개발된 노인용 구두는 소비자의 요구에 조금 더 부합하게 하였고, 향후 보다 편리하고 기능성이 향상된 노인용 구두를 제시하기 위한 최적의 라스트를 제작하고 건강기능성 부자재를 선정할 수 있는 기반을 마련하였다.

• Fire Science and Engineering
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• v.34 no.3
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• pp.141-149
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• 2020

The Korea Industrial Standards (KS) stipulates methods and test procedures for measuring the horizontal combustibility of cellular plastics exposed to small flames (KS M ISO 9772:2018) and recommendations regarding the magnetic digestion of extruded polystyrene insulation (XPS) for measurement results (KS M 3808:2020). Although products that are certified to conform to KS standards must have burning characteristics (self-extinguishing), they are incinerated and spread by welds at construction sites, causing significant human and property damages. In this study, XPS produced by five companies, certified by KS, and sold in the market were purchased and tested for ignition and diffusion caused by a weld bullion at a construction site. The results showed that the five products had differences in performance. Three out of the five products were found to be self-saturated, but the other two were easily ignited and diffused, making it difficult for them to be self-extinguishing. Based on the result of this experimental investigation in line with the KS regulations, all the three types of products, including two types of products that were incinerated through weld defects, were found to be non-self-extinguishing, as specified in KS M 3808.

• Aerospace Engineering and Technology
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• v.13 no.2
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• pp.167-176
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• 2014

The pyrovalves are widely used in aerospace industry for the opening and closing of flow channel due to the light-weight, high reliability and zero-leakage. In the United States, the loss of some spacecrafts using hydrazine as the propellent were proven by the blowby. Blowby is defined as the leakage of pyrovalve ignition combustion gas to the flow channel. Since then, the interference fit was applied for the sealing of piston to prevent the blowby. In this study, literature survey on pyrovalve technology is summarized mainly for AIAA papers. Common problems, improvement method, and performance comparisons of pyrovalves are also presented.

• Transactions of the Korean Society of Automotive Engineers
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• v.11 no.1
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• pp.64-71
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• 2003

In order to analyze the effect of the chemical structure and the cetane number of reformed diesel fuels by ultrasonic energy irradiation, proton nuclear magnetic resonance spectrometer$(^1H-NMR)$ was used. From the study, following conclusive remarks can be made. 1) Branch Index(BI), aromatics percentages, and alpha methyl radical$(H_{\alpha})$ of the reformed diesel fuels by ultrasonic energy irradiation decreased more than the conventional ones. 2) All the cetane numbers which were calculated from carbon type structure and hydrogen type distribution of the reformed diesel fuels increased more than the conventional ones. 3) It is more reasonable to predict cetane number equation from carbon type structure than from hydrogen type distribution. 4) BI, aromatics percentages, and $H_{\alpha}$ on both for conventional fuel and reformed diesel fuels by ultrasonic energy irradiation are inversely proportional to cetane number fur these fuels.

• Journal of the Korean Chemical Society
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• v.26 no.3
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• pp.142-147
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• 1982

Substituent effects on the fluorescence of 2-(substituted anilino) nicotinic acids and their aluminum chelate compounds were examined, and satisfactory linear relationships between Hammett substituent constant, ${\sigma}$, and the lowest excited singlet energy levels were obtained. Effects of solvent on the native and aluminum chelate compounds were also investigated.

• Proceedings of the KIEE Conference
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• 2015.07a
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• pp.1531-1532
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• 2015

본 논문에서는 태양광 발전설비 보급에 따라 증가하고 있는 태양광 접속함의 화재 사례를 분석하고 착화재현실험을 통하여 전기화재 위험성을 분석하였다. 전압 및 전류에 따른 태양광 접속함의 온도변화 특성을 분석하였으며, 특히 태양광 접속함의 트래킹에 의한 착화실험과정 통하여 전기적 특이점을 분석하고 트래킹에 의한 전기화재 예방대책을 제시하였다.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.1
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• pp.359-368
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• 1996

For fuel economy and pollutant reduction, the interests in lean burn has increased recently. The purpose of this research is to develop a High Frequency Ignition System (HIS) that can make powerful ignition. We studied relations between performance of HIS and probability of inflammation under various ignition conditions. It is concluded that the portion of capacitance energy to the total energy is comparatively larger and that the optimum spark interval and spark duration are dependent upon conditions of Constant Volume Combustion Chamber.

• Journal of the Korean Society of Propulsion Engineers
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• v.19 no.5
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• pp.15-21
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• 2015

The thermal decomposition characteristics of the ZPP(Zirconium/Potassium perchlorate), widely used as a primary charge of initiators, were investigated by differential scanning calorimetry(DSC). The DSC results with different heating rates were elaborated with AKTS-Thermokinetics software for the determination of the kinetic parameters of the thermal decomposition of ZPP. There was good agreement between the experimental and the simulation curves, based on the determined kinetic parameters, which indicates the validity of the kinetic description of the thermal decomposition process of ZPP.

• Journal of the Society of Disaster Information
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• v.17 no.3
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• pp.617-626
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• 2021

Purpose: The purpose of this study is to evaluate the fire srpead risk of building exterior and roofing materials due to the firebrand of forest fire occurring in the urban areas. Method: In order to achieve this research purpose, by selecting building materials used for exterior and roofing materials of buildings, the time to ignition, total heat release, and heat release rate were investigated, and a forest fire firebrand system was established to the possibility of fire spread was confirmed. Result: As a result of the cone calorimeter test, the roofing material had a similar or faster ignition time due to radiant heat compared to the exterior material with the steel plate exposed to the outside, and showed a higher heat release rate and total heat release than the exterior material. Although it was affected by the flammable material, it was confirmed that it did not spread easily due to the limited amount of combustible material, and carbonization marks appeared inside. Conclusion: The cone calorimeter test method has been shown to be useful in understanding the combustion characteristics of building materials by radiant heat, but the fire spread due to a firebrand in a forest fire is directly affected by the flame due to the ignition of surrounding combustibles, so finding a direct correlation with the cone calorimeter method is difficult. It is judged that the roof material may be more vulnerable to the spread of fire due to the fire than the exterior material.