• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.15 no.3
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• pp.291-300
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• 2004

Due to the rapid growth of mobile communication services, many studies have been performed on the biological effects of EMF(Electromagnetic field) exposure. However, it is not easy to create the field uniformity in radio frequency. To overcome this difficulty, the electric field and SAR(Specific Absorption Rate) distribution is developed to measure the whole body exposure system. In this paper, we developed the whole body exposure system for in-vivo study utilizing reverberation chamber which has a high possibility of practical use by substituting previous the EMC chamber. The field uniformity in the test area of the designed reverberation chamber was satisfied by the simulation and measurement data. In animal study of the whole body exposure for a mouse, the results of FDTD simulation were compared with those of measurement to confirm SAR under the electromagnetic exposure. We analyze the electric field distribution in the interior of the reverberation chamber and treat these results in statistical manner. In the CDMA frequency band(PCS ＆ Cellular band), an average value of the whole body SAR and local peak value for a experimental mouse were presented for various input power.

• Journal of Ocean Engineering and Technology
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• v.20 no.2 s.69
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• pp.59-65
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• 2006

Steel, as a reinforcing mechanism in concrete, provides the tensile strength that is lacking in concrete, alone, and the high alkaline environment (pH 12.5) in concrete offers satisfactory protection against most corrosion of the steel. However, the corrosion of reinforcing steel in concrete can occur by chloride attack or carbonation, and it can cause a loss of integrity a section and concrete failure through cracking and spalling. In this study, a transient electro magnetic method (TEM) of a nondestructive technique is adapted to study the measuring method of steel corrosion in mortar. The sensor was made of an enameled wire, with a diameter of 0.25mm and anacril. He sensor configuration used was a coincident loop type. The secondary electro motive force (2nd EMF) was measured with SIROTEMIII, which equipped the accelerator. The accelerator allowsthe transmitter to turn off approximately $10\sim15$ times faster than normal. The high-resolution time series, used for very shallow or a high resistivity investigation was selected. After steels were corroded by the salt spray, during 4, 8, 15 and 25 days, they were embedded in mortar. The content results acquired in this study are as follows. The variation of the secondary electro motive force (2nd EMF) was shown by the change of steel surface with different corrosion time steel. It was confirmed that measurement of steel corrosion in mortar by a transient electro-magnetic method (TEM) can be possible.

• Journal of Sensor Science and Technology
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• v.21 no.1
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• pp.75-81
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• 2012

Optimizing the tapping time of a blast furnace is important to a stable operation and life extension. To optimize the tapping time of the blast furnace, the location of Hearth Liquid Level should be recognized. There are several ways to measure the hearth liquid level in the blast furnace, such as Electromotive Force(EMF) measurement, pressure measurement by putting in nitrogen probe and manometry with strain gauge. In this paper, it will be discussed using strain gauge among the three methods. Conventional strain gauge must be revised periodically. Since, internal pressure, temperature of internal refractory material and wind pressure have effect on the strain gauge. However, static pressure value is required to compensate. To solve these problems, this paper suggests finding relationship between Hearth Liquid Level and strain gauge output, adding digital filter in strain gauge. Using the proposed method, it was possible to estimate the hearth liquid level and determine the appropriate tapping time. Usefulness of the proposed method through simulations and experimental results are confirmed.

• Journal of Sensor Science and Technology
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• v.3 no.1
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• pp.61-67
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• 1994

In order to investigate the effects of heat treatment on the thermoelectric motive force (EMF) of type R thermocouples, the changes of EMF in the freezing points of aluminum and silver cells were measured with the immersion depth of themocouples. With the variation of heat treatment methods before use, it was found that the EMF values were different from each other, maximum $17.1{\mu}V$ at $660.323^{\circ}C$ and $18.1{\mu}V$ at $961.78^{\circ}C$. Additionally a thermocouple, which was not heat-treated fully, showed an EMF difference with the immersion depth even though it was located on the region maintained at the constant temperature. The measured differences were about maximum $7.8{\mu}V$ at the Al freezing point and $18.9{\mu}V$ at the Ag freezing point. It was recongnized that a thermocouple for the precise temperature measurement should be heat-treated carefully before service. In this report, the proper heat treatment methods for the type R thermocouple were given on the basis of the obtained experimental results.

• Journal of Radiation Protection and Research
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• v.48 no.3
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• pp.153-161
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• 2023

Background: Fukushima Medical University (FMU) is located 57 km northwest of the Fukushima Daiichi Nuclear Power Plant. Our laboratory has been conducting environmental radiation measurements continuously before and after the nuclear accident. We aimed to report the observed behavior of radiation originating from the released radioactive materials due to the accident, predict future trends, and disseminate the results to the local residents. Materials and Methods: Measurements of the counting rate by a diameter of 76 mm and a length of 76 mm thallium-doped sodium iodide (NaI[Tl]) scintillation detector (S-1211-T; Teledyne Brown Engineering Environmental Services) in the central part of the laboratory, and the dose rate outward at the window by NaI(Tl) scintillation detector and digital processor (EMF211; EMF Japan Co. Ltd.) were conducted. Results and Discussion: Measurements by Teledyne S-1211-T showed that in the early stages, radiation from radioactive isotopes with short half-lives was dominant, while radiation from radioactive isotopes with longer half-lives became dominant as the measurement period became longer. Through nonlinear least squares regression, both short and long half-lives were successfully determined. It was also possible to predict how the radiation dose would decrease. The environmental radiation trends around FMU were measured by the EMF211. Both measurements were affected by rainfall and snow accumulation. Decontamination work on the FMU campus impacted measurements by the EMF211 especially. Conclusion: The results of two types of measurements, one at the center and the other at the window side of the laboratory, were presented. By applying a simplified model, radiation from radioactive isotopes with short and long half-lives was identified. Based on these results, future trends were predicted, and the information was used for public communication with the local residents.

• Korean Journal of Materials Research
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• v.6 no.2
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• pp.228-234
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• 1996

BzCuO2 의 생성 자유에너지를 이중 이온교환된 Ba2+-$\beta$/$\beta$"-AI2O3를 전해질로 사용하여 다음과 같은 생성셀로부터 측정하였다. Au(po2=10-3)/Au+BaCuO2+CuO// Ba2+-$\beta$/$\beta$"-Au이 갈바닉셀에서 BzCuO2 의 임의의 생성식과 생성자유에너지는 다음과 같다. BaO+CuO=BaCuO2 $\Delta$fGo/kJ.mol-1=-77.3-3.3x10-3T/K.3x10-3T/K.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.48 no.7
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• pp.832-838
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• 1999

Recently, there are growing concerns about power frequency electric and magnetic fields coming out from the high voltage transmission lines, because of the wide spread perception of their probable harmful effect on human body. In connection with this trend, this paper describes the electric and magnetic fields measurement result around 154 kV and 345 kV transmission lines, a comparison of measured EMF to calculated one and the correlations between transmission lines currents and measured magnetic fields. Daily maximum and minimum magnetic field quantities under the selected 154 kV and 345 kV transmission lines had been measured for 1 year of 1997 and the average value of magnetic field exposure under the lines were calculated and presented based on the measured data.

• Journal of the Korean Ceramic Society
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• v.32 no.9
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• pp.1040-1046
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• 1995

The formation free energy of Y2Cu2O5 was measured by the partial ion exchanged (Cu2+, Na+)-$\beta$/$\beta$"-Al2O3 as solid state electrolyte. The formation cell was built as follows: Pt(O2)/Y2Cu2O5＋Y2O3//(Cu2+, Na+)-$\beta$/$\beta$"-Al2O3//CuO/(O2)Pt The virtual formation formation formula, and the calculated formation free energy of Y2Cu2O5 as a function of temperature are as follows: 2CuO＋Y2O3=Y2Cu2O5 ΔfG0/kJ.mol-1=13.19-16.25*10-3T/K.5*10-3T/K.

• Proceedings of the KIEE Conference
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• 1997.07a
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• pp.97-99
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• 1997

For two decades and more, a lot of research work on the biological effects of EMF (Electromagnetic Field) on human health have been reported. Electric facilities in a typical substation are the main source of magnetic field. This paper presents the measurement and analysis of magnetic field in 345/154KV outdoor substation. The magnetic field depends on the currents which distributed by electric facilities. The result of this paper will be able to be used as basic informations to reduce the level of EMF from the electric utility facilities.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.24 no.10
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• pp.1008-1016
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• 2013

SAR measurement which was applied only to the mobile phone has been expanded in the Korean radio regulation law to the portable wireless communication equipments within 20 cm from the human body since Jan. 2012. The two-way radio operating at 150 MHz frequency band was newly included following the revised radio regulation in the target equipment of measurement. SAR measurement system at 150 MHz satisfying this regulation is necessary accordingly for SAR conformity assessment. The international SAR measurement standard(IEC 62209-2) includes the evaluation method on frequencies above 300 MHz, and the commercial SAR measurement system can measure SAR above 300 MHz only. The size of the reference dipole antenna(760 mm, return loss: -27.57 dB) and flat phantom ($1,300 mm(L){\times}900 mm(W){\times}200 mm(H)$), targeted SAR values for numerical analysis(1 g: 1.08 W/kg, 10 g: 0.77 W/kg) for SAR validation evaluation at 150 MHz frequency are proposed in this paper. The suggested dipole antenna and flat phantom are assembled and used to verify the conformity assessment of commercial SAR measurement system. The measured SAR values of 1 g and 10 g were obtained respectively to be 1.13 W/kg, 0.81 W/kg, and they satisfied the effective range(within ${\pm}10$ %) of IEC international standard. The standards based on this study are expected to be used for the domestic SAR measurement standard and IEC(International Electrotechnical Commission) international standard.