• Proceedings of the Korean Reliability Society Conference
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• 2006.05a
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• pp.371-379
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• 2006

자동차용 필라멘트 전구는 모든 차량의 전조등, 안개등, 후진등에 사용 되며, 특히 H1, H3, H4 제품은 가장 대중적이고 차량의 적용율이 높은 제품으로 적은 체적에서 높은 광속 효과를 얻을 수 있어 차량용 조명등에 적용되고 있다 본 글에서는 안정성 및 신뢰성이 확보되지 않은 국내 자동차용 전구 및 저가의 중국산 제품에 대해 품질이 우수한 선진제품과의 신뢰성 수명 비교 평가를 통하여 현재 국산제품의 신뢰수준을 확인하고 평가결과를 제조업체에 Feed Back 하여 자동차용 필라멘트 전구의 신뢰성향상에 기여하고자 한다.

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.854-856
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• 2002

필라멘트의 트위스트피치가 Bi-2223테이프의 통전손실에 미치는 영향에 대해 실험적으로 조사하였으며, 그 주요 결과는 Bi-2223테이프의 자기자계손실은 필라멘트의 트위스트피치에 의해서는 그다지 영향을 받지 않는 반면 외부교류자장 하에서 Bi-2223테이프에 발생되는 통전손실은 트위스트피치에 영향을 비교적 크게 받으며, 필라멘트의 트위스트피치가 작을수록 통전손실도 작아진다.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.111.2-111.2
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• 2016

주사전자현미경은 시료표면에 전자빔을 주사하여 시료와 전자빔간의 상호작용으로 발생하는 이차전자(SE)와 후방산란전자(BSE)를 이용하여 시료표면을 관찰하는 장비이다. 일반적으로 텅스텐필라멘트를 사용하며, 10E-5 mbar이하 압력의 고진공에서 시료관찰이 이루어진다. 고진공 시료관찰시 도체 시료는 표면 코팅 없이 관찰이 가능하지만, 부도체 시료의 경우 전자빔에 의한 대전(Charging)현상이 발생하여 이미지가 왜곡되며, 이를 방지하기 위해 금, 백금 등의 금속을 표면에 코팅하여야 한다. 하지만 10E-1 mbar 이상 압력의 저진공에서는 부도체 시료도 전자빔에 의한 대전(Charging)현상이 발생하지 않아 생물시료 등의 부도체 시료를 표면코팅 없이 관찰할 수 있다. 본 발표에서는 현재 개발 중인 CeB6 필라멘트를 탑재한 저진공 주사전자현미경의 차동배기구조를 보여준다. 차동배기에 의해 가동 압력 10E-1 mbar이상의 저진공을 유지하는 시료실과 CeB6 필라멘트를 사용하기 위한 10E-6 mbar이하의 고진공을 유지하는 전자총실의 진공 배기특성을 보고한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.07a
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• pp.522-525
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• 2003

기존 애자형 피뢰기의 문제점인 폭발 및 비산으로부터 보다 안전하여 최근 각광을 받고 있는 폴리머 피뢰기에서 필라멘트 와인딩을 망사형 구조로 제작하고 제작된 필라멘트에 실리콘 하우징을 단일 사출 성형한 구조로 시료를 제작하여 기밀특성 및 방압특성에 대해 검증하였다. 시험결과로 제시된 자료는 추후, 제품의 양산 및 현장 적용에 많은 도움을 줄 것으로 사료된다.

• Electrical & Electronic Materials
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• v.17 no.9
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• pp.16-22
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• 2004

오늘날 반도체 기술의 획기적인 발전에 의해서 마침내 에디슨의 탄소 필라멘트 백열전구를 대체할 수 있는 "반도체 필라멘트"라 불리는 고출력 백색 LED(lighting emitting diode)가 차세대 조명광원으로 급부상하고 있다.(중략)

• Journal of the Korean Vacuum Society
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• v.18 no.6
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• pp.481-487
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• 2009

To control the diameter size of the carbon nanofilaments (CNFs), SF6 was incorporated in the source gases ($C_2H_2/H_2$) during the initial deposition stage. The source gases and $SF_6$ were manipulated as the cyclic on/off modulation of $C_2H_2/H_2/SF_6$ flow in a thermal chemical vapor deposition system. The characteristics of the CNFs formation on the substrate were investigated according to the different cyclic modulation processes and the substrate temperatures. By $SF_6\;+\;H_2$ flow injection during the cycling etching interval time, the diameter size of CNFs was extremely decreased. The cause for the decrease in the diameter size of the individual CNFs by the cyclic on/off modulation process of $C_2H_2/H_2/SF_6$ flow was discussed in association with the slightly enhanced etching ability by the incorporation of $SF_6$.

• Journal of the Korean Society of Radiology
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• v.15 no.2
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• pp.181-189
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• 2021

This study is a prior research to manufacture a thermoplastic mask, which is a fixture used in radiation therapy, by 3D printing. It proceeded to analyze the filament material that can replace the thermoplastic. Among the commercially available filament materials, a material having similar characteristics to that of a thermoplastic mask was selected and the radiation dose was compared and analyzed. The experiment used Monte Carlo simulation. The shape in which the mask fixed the head was simulated for the ICRU sphere. The photon fluence was calculated at the skin Hp (0.07), the lens Hp (3), and the whole body Hp (10) by applying a thermoplastic plastic material and a filament material. As a result, when looking at the relative dose based on the thermoplastic plastic material, the difference was approximated within 4%. The material showing the most similar dose was PA-nylon. In selecting an appropriate filament material, it should be selected by comprehensively considering various conditions such as economical efficiency and radiation effects. It is thought that the results of this study can be used as basic data.

• Analytical Science and Technology
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• v.21 no.6
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• pp.487-494
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• 2008

An experiment was performed for zone refined Re-filament and normal (nonzone refined) Re-filament to reduce the background effect on the measurement of low level uranium samples. From both filaments, the signals which seemed to come from a cluster of light alkali elements, $(^{39}K_6)^+$, $(^{39}K_5+^{41}K)^+$ and $PbO_2$ were identified as the isobaric effect of the uranium isotopes. The isobaric effect signal was completely disappeared by heating the filament about $2000^{\circ}C$ at < $10^{-7}$ torr of vacuum for more than 1.5 hour in zone refined Refilaments, while that from the normal Re-filaments was not disappeared completely and was still remained as 3 pg. of uranium as the impurities after the degassing treatment was performed for more than 5 hours at the same condition of zone refined filaments. A threshold condition eliminating impurities were proved to be at 5 A and 30 minutes of degassing time. The uranium content as an impurity in rhenium filament was checked with a filament degassing treatment using the U-233 spike by isotope dilution mass spectrometry. A 0.31 ng of U was detected in rhenium filament without degassing, while only 3 pg of U was detected with baking treatment at a current of 5.5 A for 1 hr. Using normal Re-filaments for the ultra trace of uranium sample analysis had something problem because uranium remains to be 3 pg on the filament even though degassed for long hours. If the 1 ng uranium were measured, 0.3% error occurred basically. It was also conformed that ionization filament current was recommended not to be increased over 5.5 A to reduce the background. Finally, the contents of uranium isotopes in uranium standard materials (KRISS standard material and NIST standard materials, U-005 and U-030) were measured and compared with certified values. The differences between them showed 0.04% for U-235, 2% for U-234 and 2% for U-236, respectively.

• Journal of the Korean Society of Radiology
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• v.16 no.3
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• pp.233-240
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• 2022

Research on the presence or absence of radiation shielding for FDM-type filaments has recently begun to be studied, but filaments with shielding capabilities are not sold in Korea, and not studies yet. Therefore, in this research, we will use HDPE (High Density Polyethylene) as a base material, select bismuth as a reinforcing material to manufacture a composite filament, evaluate the shielding ability, and provide basic data for the development of a radiation shielding composite material using 3D printing.A filament is produced by mixing Bismuth with an effective atomic number 83 with HDPE of PE series and adjusting the content of Bismuth to 20% wt, 30% wt, 40% wt. Compounded filaments were evaluated for their physical properties and shielding capabilities by ASTM evaluation methods. As the bismuth content increases, the density, weight, and tensile strength increase, and the shielding capacity is confirmed to be excellent. As a result of the radiation shielding capacity evaluation, it was confirmed that HDPE (80%) + Bi (20%) showed a shielding rate of 82% at 60 kV and a shielding rate of up to 94% or more at 40% bismuth content. In this study, we confirmed that it was possible to produce a radiation shield that is lighter than the metal particle-containing filaments. Furthermore, that have been shield radiation by using HDPE + Bi filaments, and radiation in the medical and radiation industries. The possibility of using it as a shielding complex was confirmed.

• Progress in Medical Physics
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• v.25 no.4
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• pp.248-254
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• 2014

The purpose of this study is to develope a control system for a small X-ray tube generator and investigate control methods for the X-ray generator. The small X-ray tube was developed for electronic brachytherapy, and thus, the new control method should be investigated, if the small X-ray tube is used for the imaging system. The Axxent S700 X-ray tube and the XF060NZZ485 high voltage generator were used to compose a X-ray imaging system and control board was developed by using AT90CAN128 MCU. The two control methods were investigated after tube voltage was set to 50 kV, one was filament current control method and the other was beam current control method. The former was subdivided into two methods according to the filament heating time, the 5 and the 10 seconds respectively. In the filament current method, the beam current did not rise up to the desired value, if the filament current had not been maintained for at least 10 seconds. The onset filament currents to generate beam current were varied from 1,300 to 1,350 mA and over 5 seconds were needed in order to reach the desired tube current value after beam current was generated. However, in the tube current control method, the beam current reached to the desired value without any time delay with the filament current of 1,500 mA. In this study, we found that the beam current control method was appropriate for the use of small X-ray tube developed for brachytherapy in the X-ray imaging system.