• Nuclear Engineering and Technology
• /
• 제52권8호
• /
• pp.1638-1649
• /
• 2020

In the case of a severe accident in a Light Water Reactor, the issue of late release of fission products, from the primary circuit surfaces is of particular concern due to the direct impact on the source term. CsI is the main iodine compound present in the primary circuit and can be deposited as particles or condensed species. Its chemistry can be affected by the presence of molybdenum, and can lead to the formation of gaseous iodine. The present work studied chemical reactions on the surfaces involving gaseous iodine release. CsI and MoO₃ were used to highlight the effects of carrier gas composition and oxygen partial pressure on the reactions. The results revealed a noticeable effect of the presence of molybdenum on the formation of gaseous iodine, mainly identified as molecular iodine. In addition, the oxygen partial pressure prevailing in the studied conditions was an influential parameter in the reaction.

• Journal of Welding and Joining
• /
• 제15권3호
• /
• pp.47-55
• /
• 1997

Dynamic characteristics of the short circuit mode are investigated using the Volume of Fluid (VOF) method. When the initial molten drop volume, contact area and wire feed rate are given, rate change of the molten bridge profiles, pressure and velocity distributions are predicted. The electromagnetic force with proper boundary conditions are included in the formulation to consider the effects of welding current. It is found that the molten metal is transferred to the weld pool mainly due to the pressure difference caused by the curvatures in the initial stage, and electromagnetic force becomes dominant factor in the final stage of short circuit transfer. Necking occurs at the contact position between the molten drop and weld pool, and the initial molten drop volume and welding current have significant effects on break-up time.

• ETRI Journal
• /
• 제29권1호
• /
• pp.70-78
• /
• 2007

A new low-voltage CMOS interface circuit with digital output for piezo-resistive transducer is proposed. An input current sensing configuration is used to detect change in piezo-resistance due to applied pressure and to allow low-voltage circuit operation. A simple 1-bit first-order delta-sigma modulator is used to produce an output digital bitstream. The proposed interface circuit is realized in a 0.35 ${\mu}m$ CMOS technology and draws less than 200 ${\mu}A$ from a single 1.5 V power supply voltage. Simulation results show that the circuit can achieve an equivalent output resolution of 9.67 bits with less than 0.23% non-linearity error.

• Journal of Electrical Engineering and Technology
• /
• 제11권4호
• /
• pp.969-973
• /
• 2016

Interruption tests were conducted using the same circuit breaker for an initial pressure of SF₆ 0.5 MPa (gauge pressure) and CO₂ mixture 1.0 MPa, 0.8 MPa, and 0.6 MPa. The pressure-rises in the compression and thermal expansion chambers were measured for verifying the computational results using a simplified synthetic test facility. Further, the possibility of the CO₂ mixture substituting SF₆ gas was confirmed. Moreover, in view of the thermal recovery capability, it has also been confirmed that the pressure of the CO₂ mixture can be reduced almost to the same value as that of the SF₆ gas by optimizing the design parameters of the interrupter.

• 한국산업정보학회논문지
• /
• 제19권3호
• /
• pp.41-48
• /
• 2014

This paper proposes a new sensor circuit using a 32 nm carbon nanotube FET (CNFET) technology for artificial skin. For future robotic and prosthetic applications, it is essential to develop a robust and low power artificial skin for detecting the environment through touch. Therefore, a sensor circuit for the artificial skin also has to be developed to detect the sensor signals and convert them into digital bits. The artificial skin sensor is based on a mesh of sensors consisting of a nxn matrix using CNFET, and the sensor outputs are connected to a current monitoring circuit proposed as the sensor circuit. The proposed sensor provides pressure measurements and shape information about pressure distribution.

• 한국산업융합학회 논문집
• /
• 제5권3호
• /
• pp.255-260
• /
• 2002

Recently, the occurrences of electrical fire have been suppressed by an earth leakage breaker(ELB), a no fuse breaker(NFB) and a fuse in case of an earth leakage, a short circuit and an over current. But it is impossible for the ELB to break the circuit in the case of the failure of pressure contacts on connecting points and the momentary short circuit. Therefore, it is require to study the constructive problem of the ELB. In this paper, we have developed the auxiliary control device, electrical fire prevention control device(EFPCD), of the ELB. And we have tested the operation characteristics of the ELB according to the load(R, L) As a result of this experiment, we could prevent the electrical fire due to the spark and the overheat occurring in the failure of pressure contacts on connecting points and the momentary short circuit.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
• /
• 제49권4호
• /
• pp.233-239
• /
• 2000

There are many difficult problems in analyzing the gas flow in puffer type circuit breaker such as complex geometry, moving boundary, shock wave and so on. To predict the interruption performance accurately, these should be considered in the simulation. In this paper, the analysis procedure of the cold gas flow in the circuit breaker is presented. Euler equation is solved by FVFLIC method which is an explicit time difference scheme for an unsteady flow computation. Moving boundaries are treated with a cell elimination-addition technique. The pressure and density in front of piston are calculated from the rate of the cell volume change. The presented method is applied to the real circuit breaker model and the pressure in front of the piston is good agreement with the experimental one.

• 한국정보전자통신기술학회논문지
• /
• 제3권1호
• /
• pp.3-7
• /
• 2010

본 연구에서는 팔뚝 전자혈압계의 코로트코프 음을 디지털로 검출하는 신호검출회로 장치를 개발하였다. 본 연구에서 개발한 혈압계의 코로트코프 음 신호검출회로를 실험하기 위하여 기존의 팔뚝 전자혈압계 (Model: SE-7000, Korea)와 개발한 전자회로의 수축기 혈압과 이완기 혈압을 측정하여 비교 분석하였다. 실험을 위한 장비는 암형 커프, 청진기, 증폭기 및 A/D보드장착 PC 등으로 구성하였다. 본 연구 결과에서 코로트코프 음 신호는 기존의 팔뚝 전자혈압계에서 검출하는 오실로메트릭 신호 검출 패턴과 비슷한 경향을 보였다. 수은 혈압계와 차이에 의한 결과에서 코로트코프 음과 오실로메트릭 신호를 비교하면 수축기 혈압은 $6.75{\pm}2.02mmHg$로 나타났고, 이완기 혈압은 $7.24{\pm}3.40mmHg$ 로 나타났다. 코로트코프 음 신호를 이용한 혈압 측정치가 정밀하게 검출된다면, 기존의 팔뚝 전자혈압계를 정밀하게 검출 가능할 것으로 판단된다.

• 한국전기전자재료학회논문지
• /
• 제33권5호
• /
• pp.350-354
• /
• 2020

In this study, a pressure sensor for each displacement was fabricated based on the silicon-based pressure sensor obtained through simulation results. Wires were bonded to the pressure sensor, and a piezoresistive pressure sensor was inserted into the printed circuit board (PCB) base by directly connecting a micro-electro-mechanical system (MEMS) sensor and a readout integrated circuit (ROIC) for signal processing. In addition, to prevent exposure, a non-conductive liquid silicone was injected into the sensor and the entire ROIC using a pipette. The packaging proceeded to block from the outside. Performing such packaging, comparing simple contact with strong contact, and confirming that the measured pulse wavelength appears accurately.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2002년도 하계학술대회 논문집 D
• /
• pp.2712-2714
• /
• 2002

Recently, the high blood pressure is appeared the most frequent disease of a man's the whole sickness. But, to treat this disease is uncertain and produces an adverse reaction of a medicine therapy. Also, a patients are burden high price for doctor's treatment. Therefore, we studied effectively and financially to execute the treatment of the high blood pressure using the Chinese Medicine Theorem that recently arousing a great interest of the people. The main theories of this paper are Blood Vessel Theory and Acupuncture. The composed circuits are low-frequency generating circuit, charging-discharging circuit. The former will substitute a needle that use in the acupuncture therapy method and the latter will charge and discharge the bioelectric action potential of a patient in Ear Acupuncture Point. Also, all circuits will be controlled a micro-computer circuit.