• Analytical Science and Technology
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• v.7 no.4
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• pp.427-434
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• 1994

For the analysis of the relatively volatile lead in blood by GFAAS(graphite furnace atomic absorption spectrophotometer), one can not raise the ashing temperature beyond certain degree due to the elevation of the baseline. Previous investigations showed that background is stabilized when the ashing temperature is raised to $700^{\circ}C$ using a matrix modifier. In this study, same result was obtained at the ashing temperature of around $550^{\circ}C$ even when the matrix modifier is not used and only Triton X-100 is used as a diluent, on an instrument which is equipped with both temperature and current controller(Shimadzu, AA-6501S) and thus the temperature control is fast and accurate. Background correction methods of $D_2$ arc and SR(self reversal) were reviewed. The results show that the absorbance is higher for the $D_2$ arc method, but the background correction is higher for the SR method.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.20 no.9
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• pp.54-60
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• 2006

Large steel industries have time-varying nonlinear loads such as electric arc furnaces. These nonlinear loads generate harmonic currents and create distortions on the sinusoidal voltage of the power system. The main objective of the static var compensator is to maintain the rms voltage at the point of common coupling within the limit. In this research, harmonic mitigation studies were conducted with and without the SVC, and time-varying harmonics were evaluated according to the international harmonic standards (IEC 61000-3-6 and IEEE Std. 519) using a cumulative probabilistic approach.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.05a
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• pp.401-406
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• 2005

In this paper, both effect of TiN-coating and effect of temperature in TiN-coating by arc ion plating on surface characteristics of TiN coated SKH51 steel are investigated by experiments. Hardness, surface roughness, TiN coating thickness and adsorption force are measured in order to evaluate the effects. For evaluation of the experimental data, the two-way ANOVA method is used. It is concluded that the furnace temperature in the rang of $400^{\circ}C\~500^{\circ}C$ in AIP processing has very little influence on the TiN coating of the SKH51 steels.

• Proceedings of the KIEE Conference
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• summer
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• pp.82-84
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• 2004

This paper has calculated DSM's latent capacity through a survey investigating electric arc furnaces in over 2,000 toe companies and related organizations. The latent capacity of DSM calculated with the same time load factor is considered in this paper. The time load factor depends on the probability of each electric arc furnace of the value to work and the consideration of experts and technician's experience. Also, this paper verifies the reliability and application of unposed capacity which compared the old latent capacity of Load Management with KEMCO and KEPCO's Direct Load Control gathering capacity.

• Proceedings of the IEEK Conference
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• 2001.10a
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• pp.404-408
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• 2001

This paper focuses on the pilot-scale investigation of direct recycling of electric arc furnace (EAF) stainless steelmaking dust. The direct recycling of EAF dust is to make pellets with the mixture of the dust and the reducing agent carbon, then introduce the pellets to the EAF. The valuable metals in the dust are reduced and get into the steel as the alloying elements. Experiments simulating direct recycling in an EAF were performed using an induction furnace. But it seems difficult to reduce all metal oxides in the dust so that some metal reducing agents added in the late stage of reduction process. The valuable metals in the dust were reduced partly by carbon and partly by metal reducing agent for the economical concern. The recovery of iron, chromium and nickel from the flue dust and the amount of metal oxides in the slag were measured. The results showed that the direct recycling of EAF stainless steelmaking dust is practicable. It wes also found that direct recycling of flue EAF stainless steelmaking dusts does not affect the chemistry and quality of stainless steel produced in the EAF. It is benefit not only for the environmental protection but also for the recovery of valuable metal resources in this way.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.566-569
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• 1996

Steel making using EAF (Electric Arc Furnace) consists of three major processes: molten steel making, slab casting and hot rolling. Orders from customers, which includes their requirements such as composition, order quantity with allowable range, width, thichness, and unit weight of coils etc, are grouped as charges for EAF to enhance the productivity of the furnace. This paper develops an efficient grouping algorithm for charges in the EAF by exploiting the order characteristics: the allowable ranges of furnace capacity, order quantity, and unit weight of coils. Numerical test shows that the proposed heuristic works very efficiently and the results are quite satisfactory.

• Journal of the Korean Recycled Construction Resources Institute
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• v.7 no.2
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• pp.93-100
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• 2019

In this study, the mechanical properties of early-age concrete were evaluated by mixing the electric arc furnace oxidizing slag fine aggregate with 30% and 50% replacement ratio. Slump test, air content test and unit volume weight test were performed for fresh concrete, and compressive strength test and chloride penetration experiments were carried out in hardened concrete. The compressive strength increased up to 7 days of curing age with increasing replacement ratio of the electric furnace oxidizing slag, but the strength decreased to 90% level of OPC concrete at 28 days of age. Regarding the result of chloride penetration test, no significant differences from OPC concrete were evaluated, which shows a feasibility of application to concrete aggregate.

• JOURNAL OF ELECTRICAL WORLD
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• no.6 s.102
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• pp.10-13
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• 1985

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2005.06a
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• pp.19-20
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• 2005

• Journal of the Korean Society of Propulsion Engineers
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• v.11 no.6
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• pp.1-8
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• 2007

The objective of the present work is to characterize design parameters of solid propellant ignitor for composite, double base, and nitramine propellants using arc image furnace. Arc image furnace and fiber optics surface reflectometer were used to measure ignition delay time and reflected optical energy of several compositions of composite, double base and nitramine base rocket propellant at different pressure levels each other. The order of ignitability was double base > composite> nitramine propellants at initial pressure of over 75 psia. The highest ignition energy was needed to ignite nitramine propellant, however, the ignition delay time decreased abruptly as the pressure increased up to the range of $75{\sim}400$ psia. The absorbtion of radiation energy could be increased by the addition of small amount of opacifiers as carbon black, ZrC, WC and burning catalyst.