• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2005.11a
• /
• pp.333-335
• /
• 2005

The simulation of electric field distribution of discharge tube with globular $ZrO_2$ and the removal characteristic of Escherichia coli by the discharge tube with globular $ZrO_2$ were estimated. The removal characteristic of Escherichia coli was related to the input voltage because the electric field is increased according to input voltage. As the particle size of $ZrO_2$ beads increased, the removal time of Escherichia coli was shortened due to the dielectric polarization of $ZrO_2$ beads.

• Journal of radiological science and technology
• /
• v.20 no.1
• /
• pp.55-59
• /
• 1997

The quality of continuous X-ray beam depends upon the half value layer which varies according to the geometric conditions, filtration thickness, and tube voltage. We compared the inverter type X-ray equipment with the conventional single phase 2 peak and the three phase 12 peak for the quality obtained by changes of the added filter thickness and the tube voltage. The quality of single phase 2 peak X-ray generator showed increase for the added filter and the tube volt-age. The half value layer is Increased the thicker the filter and the higher the kVp. The quality of the Inverter type and the three phase 12 peak in comparison with the single phase 2 peak X-ray generator is increased.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.18 no.11
• /
• pp.3008-3020
• /
• 1994

Condensation heat transfer on a single horizontal tube with electric fields (Electro-Hydro-Dynamics, (EHD)) has been studied experimentally. Results are presented for EHD enhanced condensation of R-113 on a single horizontal tube using several electrode geometries. Especially, its attention was focused on the effects of electrode geometry, electric field strength and the gap of the electrode. In this study, single wire, helical, ring and mesh electrode were used. The range of the imposed voltage was 0~20 kV. As the voltage was increased the surface of liquid became an unstable wave, stream jet, liquid column and then liquid extraction in sequence. Among the various kinds of electrodes, the single wire electrode is suitable for practical application.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2004.05a
• /
• pp.285-289
• /
• 2004

In this research, we used discharge tube without dielectric bead or with dielectric beads$(SiO_2,\;Al_2O_3,\;or\;ZrO_2)$ for removal of Escherichia coli. At the result of experiments, the removal characteristics of Escherichia coli appeared relation ratio to input voltage. Because, the electric field of discharge tube is increased when input voltage is increased. And, discharge tube used dielectric $bead(ZrO_2)$, the removal characteristics of Escherichia coli was better than cases of else.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2004.05b
• /
• pp.38-42
• /
• 2004

In this research, we used discharge tube without dielectric bead or with dielectric beads($SiO_2$, $Al_2O_3$, or $ZrO_2$), and discharge in water for removal of Escherichia coli. At the result of experiments, the removal characteristics of Escherichia coli appeared relation ratio to input voltage. Because, the electric field of discharge tube is increased when input voltage is increased. And, discharge tube used dielectric bead($ZrO_2$), the removal characteristics of Escherichia coli was better than cases of else.

• Journal of radiological science and technology
• /
• v.3 no.1
• /
• pp.43-48
• /
• 1980

An experimental study was carried out to make a comparison between tube voltage and density of barium sulphate in the stomach radiography. The results were summarized as follows: 1. The percentage of density on concentrations of barium sulphate as contrast media could not show in differences with changes of voltages applied X-ray tube. 2. The changes of density visualized on X-ray film mainly depend upon with thickness of stomach filled barium sulphate than the ratio of barium sulphite and plain water volume. 3. The lesions positioned in upper part within stomach exhibited their best discrimination performanance with depth in the low tube voltage, followed in order by the middle part and lower part. However, the discrimination performanance at the high tension radiography uniformly visualized over X-ray film without density in change.

• Journal of the Korean Society of Radiology
• /
• v.5 no.5
• /
• pp.261-265
• /
• 2011

The purpose of this study is to calculate correction factors for energy dependence of a nanoDotdosimeter to measure patient's skin dose in diagnostic radiography. The correction factors were calculated by using the values of mean energy for the RQR standard radiation qualities of IEC publicated by Rosado et al. and the energy response graph of dosimeter relative X-ray on phantom calibration provided by landaur corporation. Results showed the correction factors of 1-1.33 over the tube voltage range of 40-50 kVp. Acquired correction factors are considered to be useful in the clinics for the measurement of accurate skin dose at each tube voltage.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.20 no.7
• /
• pp.2298-2314
• /
• 1996

Electric field effect on boiling of refrigerants R11, R113, and FC72 has been investigated experimentally. One purpose of the experimental investigation is to determine the effects of the electrode arrangements on electrohydrodynamic boiling of the above mentioned liquids. The test equipment employed in the experiment consists of a shell and tube heat exchanger with six or six and twelve rows of electrode wires around the tube. It has been found that the applied voltage promotes the boiling heat transfer coefficient except FC72. Boiling heat transfer enhancement obtained is about 230% for R11, 280% for R113. It has also been observed that bubbles detached from the tube aggregate at the place where the electrical gradient force balances with the buoyancy one. These aggregated bubbles force to decrease the boiling heat transfer coefficient as well as to reduce the voltage needed to the dielectric breakdown.

• Applied Chemistry for Engineering
• /
• v.21 no.2
• /
• pp.205-210
• /
• 2010

In this study, a brass electrode gas discharge tube (GDT) was prepared to investigate its discharge characterization, which affects surge protection efficiency and lifetime of GDT. Discharge characterization of GDT using a brass electrode was investigated by changing applied voltage gradient and nitrogen gas pressure inside the GDT. As applied voltage gradient in GDT increased, electrical breakdown voltage and threshold energy largely increased and electrical breakdown time delay decreased. It was found that electrical breakdown voltage, electrical breakdown time delay, and threshold energy were largely decreased with decreasing the nitrogen gas pressure in GDT. As a result, electrical breakdown voltage, electrical breakdown time delay, threshold energy needed to be decreased to increase surge protection efficiency and lifetime. It was also found that the nitrogen gas pressure of GDT influenced strongly the performances as well as life span of it.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.18 no.5
• /
• pp.156-161
• /
• 2004

In this research, we used discharge tube without dielectric bead or with dielectric beads(SiO$_2$, $Al_2$O$_3$, or ZrO$_2$), and discharge in water at High-voltage pulse$.$DC power supply for removal of Escherichia coli. At the result of experiments, the removal characteristics of Escherichia coli appeared relation ratio to input voltage. Because, the electric field of discharge tube is increased when input voltage is increased. And, discharge tube used dielectric bead(ZrO$_2$), the removal characteristics of Escherichia coli was better than cases of else. And discharge used DC Power, the removal characteristics of Escherichia coli was better than AC Pulse Power.