• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1639-1642
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• 1994

The severe conditions such as rated voltage of 800kV, gas pressure of $5kg/cm^2$ and rated lighting impulse withstand voltage of 2400kV were adopted for the design of spacers in the 800kV GIS to give a sufficient design margin. The design criteria on the maximum electric field strength of the center conductor and the insulator surface were established by considering the insulator surface characteristics, electrode area and surface effects in the unequal electric field strength of the given gap. The design parameters such as inter/outer envelope degree, thickness, inter/outer inserts, triple junction gap were determined by calculating the electric field using FLUX-2D program package and by referring to the published papers. The mechanical stress analysis was conducted on the feasible model spacers that showed good electric field distributions to confirm the sufficient mechanical design margin. The 800kV spacer designed as described above is now in the process of manufacturing.

• Proceedings of the KIEE Conference
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• 2000.07c
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• pp.1608-1610
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• 2000

In this work, the effect of annealing on physical and electrical properties of XLPE cable insulation was investigated. One sample was non-annealed and the other two samples were treated under air circulated oven at 80$^{\circ}C$ for five and ten days. In the DSC patterns of annealed specimen, new peaks appeared at near 80$^{\circ}C$ as a proof of thermal history. The degree of crystallinity increased by annealing effect. In the FT-IR spectrums, the change of absorbances to acetophenone and cumyl alcohol were observated according to the radial direction of cable insulation. They slowly diffused into both semi-conductive layer of the cable in proportion to annealing time and lastly led to near equilibrium state through cable insulation. The AC breakdown strength did not increased but the values were stabilized by effects of crystallinity and diffusion of by-products.

• Tribology and Lubricants
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• v.13 no.3
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• pp.115-123
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• 1997

The electrorheological (ER) behavior of suspensions in silicone oil of silica gel powder (average particle size 49 $\mu$m) absorbed water was investigated at room temperature with electric fields up to 2.4 KV/mm. In this paper, for development of succcessful ER fluids used for wide temperature range later, we would like to know a fundamental understanding of water on ER effect. As a first step, the ER fluids involving water activated silica gel were measured not only the electrical characteristics such as dielectric constant, current density and electrical conductivity but also the rheological properties on the strength of electric field, the quantity of dispersed phase and absorbed water. From the experimental results that water absorbed to the particles directly affects to the surface charge density of electric double layer model proposed by Schwarz and makes dielectric constant and current density of ER fluids increase. The current density and dynamic yield stress $($\tau$_y)$ of water activated silica gel suspensions was in exponential proportion to the strength of electric field, the quantity of dispersed phase and absorbed water. And the optimum water quantity and weight concentration of silica gel for electrorheological effect were 4-5 wt% and 15 wt%, respectively.

• Journal of Sensor Science and Technology
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• v.9 no.2
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• pp.120-126
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• 2000

This paper dealt with the developed portable electric field meter which consisted of planar-type sensor, analog amplifier with gain controller, A/D convertor, and display unit. The principle of the planar-type sensor for detecting time-varying electric field of extremely low frequency (ELF) bandwidth was described, and a calibration system using cylindrical guard electrodes and parallel-plate electrodes was proposed. From the calibration experiment, the frequency bandwidth and the sensitivity of the developed electric field meter was $17[Hz]{\sim}7[kHz]$, and 4.45[mV/V/m], respectively. Also it can measure the electric field strength up to 10[kV/m], and the measured result was displayed on the liquid crystal display in digit. The electric field meter can be widely applied to measure electric field strength radiated from power lines, computers, and home appliances such as hair dryer, heater, etc.

• Restorative Dentistry and Endodontics
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• v.46 no.4
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• pp.55.1-55.9
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• 2021

Objectives: The purpose of this systematic review was to collect and discuss the technique of adhesive systems application on dentin substrate under electric current. Materials and Methods: The first search strategy was based on data available at PubMed, LILACS, Scielo, Scopus, and Cochrane Library, using a combination of descriptors such as "dentin bond agents OR adhesive system AND electric current OR electrobond" or "dentin bonding agents OR dentin bonding agent application OR adhesive system AND electric current OR electrobond", with no limit regarding the publication year. The second search strategy was based on the articles' references found previously. An additional search strategy was applied that concerned the proposed theme in the SBU-UNICAMP (Unicamp's Library System Institutional Repository). Results: Twelve studies published between 2006 and 2020 were found. The analyses of the selected studies showed that the use of electric current during adhesive systems application on dentin, whether conventional or self-conditioning, increases resinous monomer infiltration in the dentin substrate, which improves the hybridization processes and the bond strength of the restorative material to dentin. Conclusions: Despite the favorable results related to the use of this technique, there is still no specific protocol for the application of adhesive systems under electric current.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.33A no.7
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• pp.99-110
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• 1996

In this paper, the analysis o fthe electric field distribution for TEM cell which is matched iwth 50 is performed, and the relations of variables for characteristic impedance are derived. Quasi-static approximations are used to calculate the fiedl strength of the internal field of TEM cell. The results of the improved method for analysis of the electric field is compared with that of R.J. Spigel. and the improved method for characteristic impedance and the results of numerical analysis are shown.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.10a
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• pp.303-306
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• 1997

In this paper, we carried out the fundamental experiments on the resistance of chemical attack of mortar using the electric arc furnace slag as fine aggregate. The mortar specimens made from the electric arc furnace slag (EAF slag) as fine aggregate were immersed in artificial seawater and two sorts of chemical solutions, and measured to investigate the change of compressive strength and weight.

• Proceedings of the KIEE Conference
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• 1997.07d
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• pp.1443-1445
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• 1997

This paper presents an analysing method to find out an optimum metal shape for insulation strength of SCI(Silicone Composite Insulator). Using finite element method, the interested parameters of the configuration such as a aspect of metal/silicone composite and a material properties are investigated and derived a thread of optimum design parameters.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.712-713
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• 2006

We successfully developed Al-Si-Transition Metal (TM) -Rare Earth (RE) Powder Metallurgy (P/M) alloy with fine microstructure, which has high strength at high temperature. This material was compacted rapidly solidified powder and directly consolidated by hot extruding or forging. Before consolidating, rapid heating was performed on powder compaction in order to keep the fine microstructure in powder state. We have also investigated the processing conditions of this new alloy by computing simulations and experiments.

• Journal of the Korean Society for Nondestructive Testing
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• v.17 no.2
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• pp.81-88
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• 1997

Impact behavior of carbon fiber reinforced plastics (CFRP) laminates were evaluated with tension test and compact tension test. A steel ball launched by an air gun collides against CFRP laminates to generate impact damage of relatively low energy. The static tensile and fracture toughness tests were performed to evaluate the residual strength and the AE behavior of impact-damaged laminates. As a results, it was found that the static strength, the fracture toughness and the AE-event count were decreased with increasing of impact velocity and delamination area, and to have a different strength ratio and fracture toughness ratio for each stacking method. And also, it was confirmed that strength and fracture toughness of impact-damaged CFRP laminates could be evaluated and analyzed quantitatively by AE techniques.