• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.2
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• pp.280-286
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• 2020

Cards made from PVC and PET materials do not oxidize or decompose readily, so they are generally incinerated or landfilled after use and cause pollution problems, such as environmental hormones and combustion gases during incineration. In addition, there is a problem of environmental pollution because they are discarded as semi-permanent refuse without being decomposed at landfill. This study attempted to solve this problem using polylactic acid (PLA), which is a representative biodegradable material as a substitute material that can solve the issues with these cards. On the other hand, when the thin card core sheet is made from only PLA material, the physical properties of the material are insufficient, such as the low temperature impact strength, high temperature stability, and poor bending properties, so its use is limited. To solve this problem, the compositional ratio of PLA was reviewed, and the optimal biodegradable compound composition was determined through an examination of the compositions, such as crystallization nucleating agents, additives, and nano compound technology. The high functionalization as a biodegradable card was verified through a laminating process using annealing technology.

• Journal of the Korean Society of Propulsion Engineers
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• v.12 no.2
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• pp.74-80
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• 2008

The feasibility study into the development of turbine spinners, which start up the turbo-pump, has been carried out and the design requirements and parameters ranges have been presented. Turbine spinners use the solid propellant as such composite propellant based AN compound with high energy plasticizers, coolants, and phase stabilizer which relieves a sensible volume change due to the phase transformation of AN near room temperature. Propellants which have a homing rate of $0.2{\sim}0.3\;mm/s$ and pressure exponent ranged from 0.3 to 0.6, showed stable burn-out in the standard motor tests. Both the magnitude of ignition energy and its thermal transfer mechanism have been proved to have a tangible effect on the ignition of the pyre starter, and the results of this study showed that a flame temperature of 1400K would be quite adequate to get a stable ignition for the AN composite propellant.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.36 no.2
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• pp.197-204
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• 2012

We explore the evolution of metal plasma generated by high laser irradiances and its effect on the surrounding air by using shadowgraph images after laser pulse termination and X-ray diffraction (XRD) of aluminum plasma ablated by a high-power laser pulse (>1000 mJ/pulse) and oxygen from air. Hence, the formation of laser-supported detonation and combustion processes has been investigated. The essence of this paper is in observing the initiation of chemical reaction between the ablated aluminum plasma and oxygen from air by the high-power laser pulse (>1000 mJ/pulse) and in conducting a quantitative comparison of the chemically reactive laser-initiated waves with the classical detonation of an exploding aluminum (dust) cloud in air. The findings in this work may lead to a new method of initiating detonation from a metal sample in its bulk form without any need to mix nanoparticles with oxygen for initiation.

• Applied Chemistry for Engineering
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• v.28 no.2
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• pp.171-176
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• 2017

The nitrogen plasma thermal decomposition and recovery processes for $CHClF_2$ (Chlorodifluoromethane) refringent were investigated. The steam generator was employed to provide superheated steam reactor, supporting the decomposition reaction of refringent. Even though over 94% of R-22 was decomposed on the condition of 60 A and 9.0 kW, a higher power and specific energy density were required to achieve the complete combustion of carbon materials. In the operating condition of 60 A and 12.6 kW, $O_2$/R-22 ratio in reactants gases are a key factor to obtain much higher decomposition ratio during process. It should be noticed that injecting the mixture of $O_2$ and air was much more effective than injecting the air consisting equivalent $O_2$ amount.

• Fire Science and Engineering
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• v.12 no.2
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• pp.3-15
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• 1998

The consequence analysis for jet and flash fire accidents by the continuous release of butane vapor was performed and effects of process variables on consequences were analyzed in standard conditions. For the continuous release (87.8 kg/s) of butane vapor at 8m elevated height in the debutanizing process of the naphtha cracking plant operating at 877 kPa, 346.75 K, we found that for the jet fire accident, shape and size of the flame could be predicted and thermal radiation estimated by API model at 200m distance from release point was 1.5kW/$m^2$, and that for the flash fire accident, effect range was 11.2~120.2m. Also, simulation results showed that effects of operating pressures on consequences were larger than those of operating temperatures and results of accidents were increased with increasing operating pressures. At this time, effects of operating pressures on XUFL were smaller(about 1/10) than those on XLFL for the flash fire accident.

• Journal of the Korean Applied Science and Technology
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• v.30 no.1
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• pp.183-196
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• 2013

The purpose of this study is to process a seaweed resources that is easy to find in Korea and has outstanding phlogistone and high yield seaweed vinegar solution through mass-production and facility development for utilization. The compound uses wasted seaweeds, such as brown seaweed, kelp, seaweed fusiform, and laver, and carbonizes them in high temperature by drying in poly step trap to extract them. In also involves the development of a process that separates and refines the extracts to create a high value-added anti-bacterial bio solution that can replace chemicals in agriculture and industries and even chemical food additives. so, studied separation and refining of seaweed extracts to analyze the compounds. and processed and compared to seaweed vinegar extracts to prove superiority.

• Resources Recycling
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• v.7 no.2
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• pp.16-22
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• 1998

Recently, the new technology for the recycling of waste plastics as an alternative he1 of blast furnace ha been developed. In this shldy, the test of plastics injection into a tuyere af the foundry blast furnace were carried out. The injection rate of plastics far this tcst facility war expressed as follows, ${W}_{s}=0.265\frac{{delta}PA}{U}_{g}$, where. Ws, AP, A and Ug are plastic conveying ratc (kgisec), pressure drop between feed hopper and blaqt pressure (alm), cross sectional area of conveying pipe (mi) and superficial velocity of transport air (mhzc) respcctiuely. From the results of semi-continuous test operation during 96 hours, the replacement raho mned out to be 1.38 according to the injection rate of 6. 4 kg-plasticsit-p. With increasing the rate of plaslics injcchon, the content of hydrogen in top gas became increased and the brick temperahlre at bzlly was also increased due to Lhe changes ot the combustion zone shape.

• Fire Science and Engineering
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• v.31 no.6
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• pp.1-7
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• 2017

Currently, flammable liquids account for more than 87 wt% of the hazardous materials in circulation in Korea, and paint products are the most commonly used mixed hazardous materials. Therefore, one of the most urgent and important issues is that we have to secure the safety for manufacturing, storage and transport of paint products. In this study we investigated and analyzed the domestic hazardous materials safety management method, the international GHS test method and so forth. We tested risks for a variety of oil paints and found a relation between the results. Furthermore, the risk test method and criteria adapted for domestic situation was presented. Paints were classified as hazardous or non-hazardous according to the results of the flash point test, the amount of flammable liquid or the UN-combustion persistence test. It was revealed from the test results of 6 kind of oil-based paints using different resins that they were hazardous materials with very high risks and belonged to the Category 1 or the Category 2.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.4
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• pp.32-37
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• 1999

The superposing effect of SPCP(Surfoce Induced Plasma Chemical Process) and corona discharge has been studied for rerroval of NOx from industrial flue gases. NOx rermval rates by SPCP, corona discharge and superposing discharge were monitored and compared. Parameters were the concentration and the flow rate of gas, frequency and the type of discharge. Experirrental results showed that NOx removal rate by sUIffPOSing discharge was 10-15[%] higher than that by the other two modes. The higher NOx. rermval rate was observed with the lower frequency of upper electrode in the combined reactor and with the higher frequency of lower electrode. 'The maximum obtainable NOx. rerroval rate by SPCP (18 [W]) and corona discharge (8.5 [W]) was 80[%] and 10[%], respectively. With the combination of the two modes, however, 90[%] of NOx removal rate was observed with the discharge power of 14 [W].14 [W].

• Journal of the Korean Institute of Gas
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• v.21 no.1
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• pp.80-86
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• 2017

In this paper, it is proposed to solve the problem of the harmful exhaust gas reduction device DPF. The exhaust gas is effectively guided through the control of the exhaust gas flow path which is separated in both directions. Through cross control of two DPF units, it helps to improve the purification and regeneration combustion characteristics of harmful emissions. It is possible to prevent an increase in internal pressure caused by deposition of particulate matter in the DPF. It is also an object of the present invention to provide an automobile harmful exhaust gas reduction device capable of solving the problem of lowering the output and lowering the fuel consumption.