• Journal of the Korean Society of Safety
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• v.3 no.1
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• pp.37-45
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• 1988

This research investigated the condition for plant design on reclamation of waste plastic by heat decomposition. The results were summarized as follows 1. The highest of oil product by heat decomposition is about 54.7％. 2. The optimum reaction temperature is about 300­40$0^{\circ}C$. 3. The optimum reaction time is 2­3 hours. 4. When the flow rate of 8­16 cm/sec in column reactor the yield is maximum. 5. Waste plastics yielded of carbon black product by heat decomposition at the optimum condition is about 23.5%. 6. Calorific values 0：1 were 9820 Kcal/kg.

• Bulletin of the Korean Chemical Society
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• v.17 no.9
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• pp.798-802
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• 1996

The photochemical decomposition of aqueous ammonia in the absence (saturated with argon) and the presence of O2 (saturated with air or oxygen) has been investigated using 184.9 nm UV light. The decomposition of ammonia depended on the concentration of oxygen in the solution. With increasing the concentration of oxygen, the decomposition of ammonia diminishes. Hydrazine is found the major product from the irradiation. In the presence of oxygen, hydrogenperoxide was also produced. The product yields depended also on the concentration of oxygen in the solution. The initial quantum yield of the products and of the ammonia decomposed were determined. Probable reaction mechanisms for the reaction were presented from the products analysis.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.2
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• pp.375-382
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• 1996

In this paper, aneffective method for computing source to terminal reliability of network by decomposition is described. A graph is modeled after a network, and decomposed into two subgraphs. A logic product term of one subgraph is computed, and a graph of the other subgraphs is made according to the event representing the logic product term, and it's logic product term is compted. By multiplying the logic product term of one subgraph by that of the other subgraphs, a method for computing the source to terminal reliability is proposed. the time complexity for computing all the logic product terms of one subgraph is the product of copies of the number of edges in the subgraph of 2, and that of the other subgraph is the number of edges multiplied by the number of logic product terms. This method requires less computation time than that not by decomposition.

• Journal of the Korean Chemical Society
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• v.16 no.3
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• pp.157-165
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• 1972

Thermal decomposition of ammonium metavanadate has been investigated by using the quartz spring balance and differential thermal analysis. It showed that the decomposition of ammonium metavanadate is proceeded at two stages which correspond to $180^{\circ}C-220^{\circ}C$ and $310^{\circ}C-330^{\circ}C$ decomposition temperatures, respectively. Evolved ammonia gas in thermal decomposition has been analyzed quantitatively by titration. And the constituents of gases evolved have been evaluated by gas chromatography and omegatron spectrometer. From these results, it was concluded that the gases evolved in the first step decomposition were $NH_3$ and $H_2O$ with 2:1 ratio and the second step decomposition corresponded to the formation of $NH_3$, $H_2O$ and $N_2O$ which was produced in oxidation of $NH_3$ by $V_2O_5$. The decomposition products were identified by means of X-ray diffraction method. The decomposition product in air was V_2O_5 and the product in vacuum $V_3O_7.$ The kinetics of the thermal decomposition was studied, giving the values of the activation energy of 41.4 kcal/mole and 64.4 (kcal/mole) respectively.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.15 no.6
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• pp.543-550
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• 2002

In this paper, the $CF_4$ decomposition rate and by-product were investigated for two simulated plasma reactors which are metal particle reactor and spiral wire reactors as a function of mixed gases. The $CF_4$ decomposition rate by plasma reactor with metal particle electrode had a gain of 20~25% over that by plasma reactor with spiral wire electrode. The $CF_4$ decomposition efficiency increases with increasing applied voltage up to the critical voltage for spark formation. The $CF_4$ decomposition efficiency of metal particle reactor was about 80% at AC 24kV. The $CF_4$ decomposition rate used Ar-$N_2$ as base gas was the highest among three base gases of $N_2$, $Ar-N_2$, air. The by-products of the $N_2$, $N_2Ar$ base as were similar, but in case of air base they were different.

• Journal of the Korean Society of Safety
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• v.21 no.6 s.78
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• pp.38-45
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• 2006

Polymeric floorings mainly consisted of PVC are easily decomposed by many kinds of hot environmental factors, then generate hazardous asphyxiate gases and/or toxic gases etc. Therefore the mechanism of decomposition and quantitative toxic indices of products are very important for preventing safety and health disasters, especially in case of confined area. So we have investigated decomposition kinetics, numbers of process involved, toxicity indices of product and so on, using DSC, TGA, FT-IR and Pyrolyzer-GC/MS. The thermal decomposition process of polymeric floorings can be mainly divided by dehydrochlorinated reaction and polyene decomposition step, and activation energies of those are approximately $53.93{\sim}62.42kcal/mol$. Especially lethal concentration($LC_{50}$), fractional effective dose (FED) are calculated by measuring the amount of decomposition product. The values on $LC_{50}$ of sample G are ranged $2,003{\sim}2,019(mg/m^{3})$ in case of sample K and H are $1,877,\;1,998(g/m^{3})$ respectively. Even if the results are estimated by calculation method without animal test and/or clinical demonstration, these values could be very useful data for occupational health, hygiene and safety control.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.85-88
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• 2006

A fluidized bed reactor made of quartz with 0.055m I.D. and 1.0m in height was employed for the thermocatalytic decomposition of propane to produce $CO_2$-free hydrogen. The fluidized bed was proposed for the continuous withdraw of product carbons from the reactor. The propane decomposition rate used carbon black N33O as a catalyst. The propane decomposition reaction was carried out at the temperature range of $600{\sim}800^{\circ}C$, paropane gas velocity of $1.0 U_{mf}\;3.0U_{mf}$ and the operating pressure of 1.0 atm. Effect of operating parameters such as reaction temperature, gas velocity on the reaction rates was investigated. The carbon which was by-product of methane decomposition reaction was deposited on the catalyst surface that was observed by SEM. Resulting production in our experiment were not only hydrogen but also several by products such as methane, ethylene, ethane, and propylene.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.28 no.6
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• pp.52-59
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• 2014

This paper deals with the effect of decomposition products which occur in breakdown of mineral oil, on the insulation characteristics of its oil. Breakdown tests in the oil were conducted by the proposed experimental methods under a quasi-uniform field and AC HV (60Hz). The breakdown voltage in the oil shows characteristics of dispersion from successive breakdowns and, it is found that there are three patterns of the decomposition products behavior at the process of breakdown progress in the oil. Finally, the breakdown voltage dispersion in the oil can be described in detail based on the behavior patterns of the decomposition products and its diffusion time.

• Korean Journal of Computational Design and Engineering
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• v.5 no.4
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• pp.359-372
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• 2000

Current CAD systems are good enough to be used as a tool to manipulate three-dimensional shapes. This is a very important capability to be owned by a design tool because a major portion of designers'activities is spent on the shape manipulation in the design detailing process. However, the whole design process involves a lot more than the, shape manipulation. Currently, these remaining tasks, mostly logical reasoning process for the function realization together with structure decomposition in the top-down manner, are processed in the designer's brain. To support the top-down functional design process of a mechanical product, a system integrating the functional, structural and geometrical aspects of a product design in a unified environment is presented. Using this system, a designer can perform function decomposition, structure decomposition, and geometry detailing, and function verification activities in parallel and the whole design process it modeled resultantly. Once the whole design process is modeled, any redesign task can be automatically performed with the verification of the desired functions.

• IE interfaces
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• v.1 no.1
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• pp.1-7
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• 1988

This paper discusses the applicability of the decomposition principle to an LP (Linear Programming) problem. Through a case study on product mix problems in a chemical process of Korean Steel Chemical Co., Ltd., the decomposition algorithm, LP Simplex method and a modified method are compared and evaluated in computation time and number of iterations.