• Journal of Conservation Science
• /
• v.2 no.2 s.2
• /
• pp.25-30
• /
• 1993

Materials (refractory, stone) of iron making furnace excavated from Kalcheon were investigated by the scanning electron microscopy(SEM) with an energy dispersive X-ray analysis (EDAX), X-ray fluorescence(XRF), and X-ray diffraction(XRD). Chemical composition of the refractory materials were $SiO_2(68.74\%),\;Al_2O_3(18.40\%),\;CaO(0.42\%),\;MgO(1.04\%)\;and\;K_2O(2.26\%)$ in weight ratio, which were the typical components presented in common clay. The results of chemical analysis for the stone and the glaze coated, alkali ion(K, Na, Ca) components of the glaze contained high concentration than that the stone. It was suggested that this change had a close relationship with the kinds of fuels used.

• Proceedings of the Korea Association of Crystal Growth Conference
• /
• 1998.06a
• /
• pp.45-48
• /
• 1998

For the single crystal growth of silicon, a global analysis of heat transfer in a CZ furnace was carried out using the finite element method, where the radiative heat transfer between the surfaces that possess both specular and/or diffuse reflectance components was taken into account, and then the effect of the specular reflection of the crystal and/or melt on the CZ crystal growth was numerically investigated.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2004.10a
• /
• pp.245-253
• /
• 2004

There has been recent demand for extending the life of age-degraded structures and equipment by such techniques as diagnosis, maintenance, safety assessment, and estimating residual life on iron-making plants and hydraulic, thermal, and nuclear power plants. These techniques take into account comprehensive scenarios that may cause malfunction and structural damage and allow an assessment of risk based on the likely scenarios. In particular the safety assessment and residual life estimation of age-degraded ships and equipment facilities require consideration of various factors such as mechanical and thermal stresses, corrosion, hardness, load variation due to changes of operating condition, crack generation and strength reduction of material by fatigue. In this study, a detail thermal stress analysis, one of useful techniques of safety assessment and maintenance, is performed on a blast furnace by using general FEM code (MSC/NASTRAN).

• Proceedings of the Korea Concrete Institute Conference
• /
• 2000.10b
• /
• pp.945-950
• /
• 2000

Coastal concrete structure is harmed by physical and chemical action of sea water, impact load, meteorological effect and etc. especially, premature reinforcement corrosion in concrete exposed to sea water has an important problem. In this study, the behavior of chloride ions penetrated through the coastal concrete structure with ordinary portland cement or ground granulated blast furnace slag(GGBFS) was modeled. The physicochemical processes including the diffusion of chloride and the chemical reaction of chloride ion with calcium silicate hydrate and the other constituents of hardened cement paste such as$C_3A$ and $C_4AF$were analyzed by using the Finite Element Method. From analysis result, the corrosion of concrete structure with GGBFS begins 1.69~1.76 times later than that of concrete structure with ordinary portland cement.

• Magazine of RCR
• /
• v.10 no.1
• /
• pp.33-38
• /
• 2015

• Proceedings of the Korean Ceranic Society Conference
• /
• 2000.10a
• /
• pp.119.1-119
• /
• 2000

• Proceedings of the Korean Vacuum Society Conference
• /
• 2012.08a
• /
• pp.357-357
• /
• 2012

The doping process of the solar cell has been used by furnace or laser. But these equipment are so expensive as well as those need high maintenance costs and production costs. The atmospheric pressure plasma doping process can enable to the cost reduction. Moreover the atmospheric pressure plasma can do the selective doping, this means is that the atmospheric pressure plasma regulates the junction depth and doping concentration. In this study, we analysis the atmospheric pressure plasma doping compared to the conventional furnace doping. the single crystal silicon wafer doped with dopant forms a P-N junction by using the atmospheric pressure plasma. We use a P type wafer and it is doped by controlling the plasma process time and concentration of dopant and plasma intensity. We measure the wafer's doping concentration and depth by using Secondary Ion Mass Spectrometry (SIMS), and we use the Hall measurement because of investigating the carrier concentration and sheet resistance. We also analysis the composed element of the surface structure by using X-ray photoelectron spectroscopy (XPS), and we confirm the structure of the doped section by using Scanning electron microscope (SEM), we also generally grasp the carrier life time through using microwave detected photoconductive decay (u-PCD). As the result of experiment, we confirm that the electrical character of the atmospheric pressure plasma doping is similar with the electrical character of the conventional furnace doping.

• Journal of the Korea Institute of Building Construction
• /
• v.4 no.4
• /
• pp.95-101
• /
• 2004

The purpose of this paper is to compare free-chloride content with water-soluble chloride in blast furnace cement(BSC) paste. The content of free-chloride in cement paste measured by pore solution analysis and water-soluble chloride measured by ASTM. The result of this study are as follows: 1. The concentration of chloride ion in pore solution of BSC-solidified matrix is almost as low as 43-71% compared to that of OPC-solidified matrix containing the same chloride content in cement paste. 2. The binding capacity of specimens, OPC Pl-P5, are 93.5-77%, but the binding capacity of specimens, BSC Pl-P5 are 97.1-86.1%, which is to be as high as 2-9.1% compared to OPC containing the same chloride content. 3. In terms of water-soluble chloride content in BSC paste are 15-31.7 percent of chloride addition but free-chloride content in pore solution are 2.9-13.9 percent of chloride addition. The free-chloride content in pore solution is 19.3-43.8 percent lower for the water-soluble chloride content in cement paste.

• 한국신재생에너지학회:학술대회논문집
• /
• 2010.11a
• /
• pp.43.2-43.2
• /
• 2010

In this study, metallurgical grade (MG) silicon with 99% purity produced by arc furnace process was systematically investigated for slag refining. The most problematic impurities to remove from MG silicon are boron (B) and phosphorus (P). To remove B and P from MG-silicon, we used synthetic slag in the molten state. MG-silicon with synthetic slag of CaO, $SiO_2$, and $CaF_2$ was melted using by high-frequency induction furnace with electrical output of 50kW. Specimens prepared by various refining process conditions(holding time, mixture ratio) were inspected by combined analysis of ICP-MS and XRF. With this approach, B has been reduced to <5ppm, P to <1ppm and other impurities to 0.1~0.2% except for Calcium. Calcium has been increased from 17ppm to 1500ppm. Problem of calcium contamination will be resolved by additional refining processes.

• Proceedings of the KIEE Conference
• /
• 2015.07a
• /
• pp.1112-1113
• /
• 2015

In the end of 2014, Changwon National University and TECHSTEEL Co., Ltd. had initiated a project on the development of a 300 kW-class HTS DC Induction Furnace(HTS DC IF) for preheating non-ferrous metal billets funded by the Korea Institute of Energy Technology Evaluation and Planning for 3 years. This is the one of the most realistic commercial machines applying the coated conductors. In this paper, the development progress of a 300 kW-class HTS DC IF was introduced. The major characteristics of the furnace including its capacity, structure and operation scheme were presented. For ensuring the successful design, a pre-validation study was performed through the electromagnetic, heat transfer and solid mechanical analysis using a multi-physics FEM tool. The aluminum billet was heated up to $540^{\circ}C$ under 1 T of the magnetic flux density at the center of the billet, and the simulation results were described in detail.