• Journal of Radiation Protection and Research
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• v.20 no.2
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• pp.103-115
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• 1995

For the determination of $^{222}Rn$ in water by a very simple and time saving liquid scintillation counting method that does not require any chemical separation, an optimum analytical condition has been investigated. The optimum pulse shape analysis(PSA) level for the measurement of $^{222}Rn$ using LKB 1220 Quantulus liquid scintillation counter was 110 for Optiphase HiSafe3 cocktail and 90 for toluene-based cocktail. The counting efficiencies of $^{222}Rn$ in the window covering u spectra using Optiphase HiSafe3 cocktail were 282.2% for glass vial and 271.6% for Teflon vial, whereas the counting efficiencies in toluene-based cocktail were 262.3% and 247.5% for glass and Teflon vials, respectively. The minimum detectable activity(MDA) in the u window for a 60-min measurement with a Teflon vial using Optiphase HiSafe3 cocktail was $0.30Bq/{\iota}$. The analytical method studied from this work was also applied to the determination of $^{222}Rn$ in some groundwater and hot spring water samples.

• Journal of the Korean GEO-environmental Society
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• v.12 no.11
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• pp.51-57
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• 2011

The calcium hydroxide($Ca(OH)_{2}$) which is flowed into the deteriorated tunnel by groundwater is reacted with carbon dioxide($CO_{2}$) and the vehicle's exhaust gas ($SO_{3}$). So its by-products are precipitated at the drainage pipe and these cause the drainage clogging. Most by-products are composed of $CaCO_{3}$ with calcite from a chemical experiment. The purpose of this study is mainly focused on comparison of attachment on each material of drainage pipe (teflon-coated steel pipe, silicon-Oil coated pipe, acrylic pipe and PVC pipe). The test was progressed to disembogue the CaO aqueous solution and tunnel outflow into each of the pipes. The experimental results show that the most produced scale pipe is PVC material and the followings are Acrylic pipe, Silicon-Oil coating pipe and Teflon coating pipe. But the long-term test results showed that teflon-coated steel pipe had a problem with durability because soil which was contained in the tunnel outflow occurred detachment of coating and corrosion of the steel pipe.

• Journal of Chest Surgery
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• v.17 no.2
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• pp.184-188
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• 1984

As OHS is prevalent on whole world, LV-RA shunts once thought as quite rare congenital heart disease are reported frequently. Two cases of LV-RA shunts were operated at N.M.C. in 1983: One of them combined VSD, the other membranous ventricular septal aneurysm protruding into right atrial chamber. In case 1, which was diagnosed correctly, right atriotomy was enough to close the defect under ECC, but in case 2, which was misdiagnosed as ASD preoperatively, atriotomy was added to ventriculotomy. The LV-RA defects were closed by U-shaped direct suture with Teflon felt pledget. Postoperative course was uneventful in both of them.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.140-142
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• 1977

Total of 52 patients having ventricular septal defect were operated on using extracorporeal circulation in the 8 years period between 1969 and 1977. Of these, the very rare and interesting were the cases of ventricular septal defect seen in twin boys. Their defects were Type II and Type III in each which had been closed with Teflon felt patch in one and with primary suture in the other. Their postoperative courses were uneventful without complications of any.

• Journal of the Korean Institute of Telematics and Electronics
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• v.27 no.5
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• pp.684-689
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• 1990

We design a circular microstrip array antenna using the admittance of circular resonator. We can design the array antenna, considering equivalent radius of circular microstdrip consistant with conductances which are obtained from excitation coefficeients of the array elements. The antenna with 10 array elements are made on teflon substrate from Tshebyscheff method. It's perfermence are the gain 8.9dB, half power beam width 11.3dge, max, side lobe level -19dB, and they are almost in agreement with the theoretical results.

• The Proceeding of the Korean Institute of Electromagnetic Engineering and Science
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• v.2 no.4
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• pp.10-16
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• 1991

A microstrip bandpass filter using stepped impedance resonators and tapped input / output is realized with Teflon substrate, whose center frequency is 3.5 GHz and fractional bandwidth is 20%. In order to realize a wider bandwidth of 30%, the Crystal's design method and the input / output tapping scheme are used. Another microstrip filter designed as mentioned above is realized with Epsilam-10 substrate. This case shows good agreement between the theoretical responses and the measured ones.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2000.11a
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• pp.364-368
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• 2000

In this paper, we present the design and fabrication of a new circularly polarized circular patch antenna. The antenna is realized using a plastic foam sheet, a Teflon substrate and a metal-coated film. The radiating element is a circular patch proximity-fed by a wide microstrip line. Two thins slots are introduced on the circular patch to obtain a circular polarized radiation. The antenna is optimized using a commercial software. The antenna has 18% impedance bandwidth, 4% axial-ratio band width and 9.12dBi gain.

• Proceedings of the Korea Electromagnetic Engineering Society Conference
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• 2002.11a
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• pp.306-310
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• 2002

본 논문에서는 기존의 혼 안테나에 Dielectric rod를 삽입하는 구조를 사용하였다. 입력구조는 Rectangular Waveguide Feed에 Cone을 접목시키는 형태로 구현되었으며 기존의 E-Plane taper구조보다 특성이 양호하며 소형화를 구현해냈다. 제작된 안테나의 중심주파수는 37GHz이며 정재파비 특성 또한 양호하다. 여러 Feeding 구조 중 Bandwidth를 좀더 확장할 수 있는 구조에 초점을 맞추어 대역폭은 13%이상을 구현했으며 시뮬레이션 툴은 Ansoft HFSS V7.0으로 최적화한 후 제작 및 측정하였다. 또한 사용된 Dielectric rod의 제질은 Teflon(ETFE, $\varepsilon$$_{r}$=2.03)을 사용하였다.

• Proceedings of the KSLP Conference
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• 1993.12a
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• pp.19-19
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• 1993

편측 성대마비에 대해서 Teflon 삽입술, 갑상연골성형술, 피열연골내전술 등 여러 술식이 사용되고 있다. 1993년 3월부터 1993년 10월까지 서올대학교병원 이비인후과에서는 여러 가지 원인으로 발생한 8례의 편측 성대마비에 대해서 피열연골 성형술을 시행하여 다음과 같은 결과를 얻었다. 원인으로는 특발성이 3례, 갑상선 수술에 후발한 것이 2례, 경부종괴절제수술에 후발한 것이 2례, 흉부수술에 후발한 것이 1례, 디프테리아가 1례였고, 좌측 성대마비가 5례, 우측 성대마비가 3례였다.(중략)

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.55-58
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• 2002

This paper describes an RF module for 2.4GHz wireless audio/video transmission. The pre-processed baseband input signals are FM-modulated using a VCO and then transmitted through an antenna after RF filtering. The designed circuits are implemented using a Teflon board of which the size is 52mm${\times}$62mm. The measured maximum output signal levels are around -3dBm and the harmonics are less than -450dBc. The manufactured module consumes 130mA from a 8V supply.