• Title/Summary/Keyword: 총 이온화 선량

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Test-bed of Total Ionizing Dose (TID) Test by Cosmic Rays for Metal Oxide Semiconductor Field Effect Transistor (MOSFET) (금속-산화막 반도체 전계효과 트랜지스터의 우주방사선에 의한 총이온화선량 시험을 위한 테스트 베드)

  • Sin, Gu-Hwan;Yu, Gwang-Seon;Gang, Gyeong-In;Kim, Hyeong-Myeong;Jeong, Seong-In
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.11
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    • pp.84-91
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    • 2006
  • Recently, all the electrical parts for satellite application are required more strong against cosmic rays, because spacecraft's life time and function are depending on the their conditions. Also, a TID effect test was undertaken with units and/or subsystems which are already assembled on the PCB in past time. However, it is very hard to know and analyze that some abnormal states are appeared after launch. Moreover, it is necessary to perform a test of TID effects based on the parts level for preparing preliminary data in cosmic rays. Therefore, this paper presents a test-bed to perform a TID effect test of Metal-Oxide Semiconductor Field Effect Transistor (MOSFET) which is a fundamental element for electronics.

Preparation of Fibrous Adsorbent Modified with Iminodiacetic Acid and Its Co2+, Fe2+, and Pb2+ Adsorption Characteristics (이미노디아세트산을 함유한 섬유상 흡착제 제조 및 코발트, 철, 납 이온 흡착특성)

  • Yang, Hyun-Soo;Choi, Jun-Kyu;Nho, Young Chang
    • Applied Chemistry for Engineering
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    • v.10 no.3
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    • pp.477-485
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    • 1999
  • The grafting of 2,3-epoxypropylmethacrylate (GMA) onto polypropylene fabric was carried out by the $\gamma$-ray preirradiation grafting technique. Subsequently, the GMA-grafted polypropylene fabric was reacted with iminodiacetic acid (IDA) in different mixed solvents to prepare the fibrous metal adsorbent. The grafting extent was found to be dependent on the reaction time, temperature, preirradiation dose and dose rate. The effects of various mixed solvents on the IDA amination onto GMA-grafted polypropylene fabric were investigated. Compared with other mixed solvents, the extent of amination was highest in the dimethylsulfoxide (DMSO)/water, but the reaction did not occur in the water. The adsorption characteristics of various metal ions by the prepared adsorbent were examined when it was immersed in the 100 ppm metal ion solution. The amount of adsorption followed the order:$Pb^{2+}>Co^{2+}>Fe^{2+}$.

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Synthesis of High Affinity Anion Exchanger Using Ultrafine Fibrous PPmb Nonwoven Fabric by Co60 Irradiation Method (방사선 조사에 의한 초극세 폴리프로필렌 섬유부직포를 이용한 고효율 음이온교환체의 합성)

  • Choi, Kuk-Jong;Lee, Choul-Ho;Hwang, Taek-Sung
    • Polymer(Korea)
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    • v.32 no.6
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    • pp.509-515
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    • 2008
  • The aminated polypropylene melt blown ion exchange fibers were synthesized with acrylic acid monomer onto polypropylene melt blown fibers by radiation-induced polymerization and subsequent amination. Degree of grafting was increased with increasing the acrylic acid monomer concentration and total dose. The highest degree of grafting was obtained 140% at a monomer concentration of 20 v/v% acrylic acid and total dose of 4 kGy. Optimum condition of Mohr's salt was 5.0 $\times10^{-3}$ M. Degree of amination was increased with increasing degree of grafting. Water content was about 1.5 times higher than that of trunk polymer. The maximum ion-exchange capacity was 7.3 meq/g which was 2$\sim$3 times higher than a commercial ion exchange fiber. The average pore size was decreased and BET surface area was increased in order of PPmb, PPmb- g- AAc and APPmb- g- AAc. The average pore size and BET surface area of synthesised fibers were $366.1\;{\AA},\;3.71m^2/g,\;143.3\;{\AA},\;4.94m^2/g,\;40.97\;{\AA},\;8.98m^2/g$, respectively.

Synthesis of High Functionalized Anion Exchange Fibers Using Hybrid Polyolefine by $\gamma-Ray$ Mutual Radiation (방사선 동시조사법을 이용한 고관능성 Hybrid Polyolefine 음이온교환섬유의 합성)

  • Cho In-Hee;Kwak Noh-Seok;Kang Phil-Hyun;Nho Young-Chang;Hwang Taek-Sung
    • Polymer(Korea)
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    • v.30 no.3
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    • pp.217-223
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    • 2006
  • Ion exchange fibers, high functionalized onto hybrid polyolefine fiber's surface, were synthesized by $\gamma-ray$ mutual radiation. Degree of grafting (DG) of copolymer increased with increasing GMA monomer concentration and the maximum rate of DG was 355% at 50 GMA. The graft reaction occurred in polar solvent and DG was 190% maximum value in $1.0\times10^{-3}$ Mohr's salt and 0.1 M sulfuric acid, respectively. The amination for graft copolymers varied depending on amine reagents, and the reactivity for copolymers was highest for methylamine, and that of triethylamine lowest. It was shown that water uptake and ion exchange capacities increased with increase in the rate of amination while surface area decreased rapidly as proceeding for graft reaction and amination.

Corrective Control of Asynchronous Sequential Circuits with Faults from Total Ionizing Dose Effects in Space (총이온화선량에 의한 고장이 존재하는 비동기 순차 회로의 교정 제어)

  • Yang, Jung-Min;Kwak, Seong-Woo
    • Journal of Institute of Control, Robotics and Systems
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    • v.17 no.11
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    • pp.1125-1131
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    • 2011
  • This paper presents a control theoretic approach to realizing fault tolerance in asynchronous sequential circuits. The considered asynchronous circuit is assumed to work in space environment and is subject to faults caused by total ionizing dose (TID) effects. In our setting, TID effects cause permanent changes in state transition characteristics of the asynchronous circuit. Under a certain condition of reachability redundancy, it is possible to design a corrective controller so that the closed-loop system can maintain the normal behavior despite occurrences of TID faults. As a case study, the proposed control scheme is applied to an asynchronous arbiter implemented in FPGA.

Development of the S-band receiver for LEO satellite (저궤도 위성용 S대역 수신기의 개발)

  • Park, In-Yong;Jin, Hyun-Peel;Lee, Soon-Cheon;Sirl, Young-wook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.44 no.3
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    • pp.212-217
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    • 2016
  • The S-band receiver for Low Earth Orbit satellite is designed and fabricated as engineering model. Demodulator is implemented by using FPGA for extension of demodulator method. The receiver consists of RF Block, Digital demodulator and Power stage and has a Doppler tracking function to compensate a frequency shift that occur on the operation. The measured results of fabricated receiver show BER of less than $1.0{\times}10^{-6}$ at -110dBm RF input power and equipped a frequency tracking of ${\pm}100KHz$ relative to the center frequency. TID test was satisfied with the results of the test criterion is 10krad.

Simulation of Characteristics Analysis by Total Ionizing Dose Effects in Partial Isolation Buried Channel Array Transistor (부분분리 매립 채널 어레이 트랜지스터의 총 이온화 선량 영향에 따른 특성 해석 시뮬레이션)

  • Je-won Park;Myoung-Jin Lee
    • Journal of IKEEE
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    • v.27 no.3
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    • pp.303-307
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    • 2023
  • In this paper, the creation of an Electron-Hole Pair due to Total Ionizing Dose (TID) effects inside the oxide of a Buried Channel Array Transistor (BCAT) device is induced, resulting in an increase in leakage current and threshold due to an increase in hole trap charge at the oxide interface. By comparing and simulating changes in voltage with the previously proposed Partial Isolation Buried Channel Array Transistor (Pi-BCAT) structure, the characteristics in leakage current and threshold voltage changed regardless of the increased oxide area of the Pi-BCAT device, compared to the asymmetrically doped BCAT structure. It shows superiority.

Synthesis of Electroactive PAAc/PVA/PEG Hydrogel Soft Actuator by Radiation Processing and Their Dynamic Characteristics (방사선을 이용한 전기 활성 PAAc/PVA/PEG 하이드로겔 소프트 액추에이터의 제조 및 구동 특성 분석)

  • Shin, Yerin;Kim, So Yeon
    • Applied Chemistry for Engineering
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    • v.30 no.6
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    • pp.698-706
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    • 2019
  • Over the last few decades, there have been a lot of efforts to develop soft actuators, which can be external stimuli-responsive and applied to the human body. In order to fabricate medical soft actuators with a dynamic precision control, the 3D crosslinked poly(acrylic acid) (PAAc)/poly(vinyl alcohol) (PVA)/poly(ethylene glycol) (PEG) hydrogels were synthesized in this study by using a radiation technique without noxious chemical additives or initiators. After irradiation, all hydrogels showed high gel fraction over 75% and the ATR-FTIR spectra indicated that PAAc/PVA/PEG hydrogels were successfully synthesized. In addition, the gel fraction, equilibrium water content, and compressive strength were measured to determine the change in physical properties of PAAc/PVA/PEG hydrogels according to the irradiation dose and content ratio of constituents. As the irradiation dose and amount of poly(ethylene glycol) diacrylate (PEGDA) increased, the PAAc/PVA/PEG hydrogels showed a high crosslinking density and mechanical strength. It was also confirmed that PAAc/PVA/PEG hydrogels responded to electrical stimulation even at a low voltage of 3 V. The bending behavior of hydrogels under an electric field can be controlled by changing the crosslinking density, ionic group content, applied voltage, and ionic strength of swelling solution.

Expression profile of defense-related genes in response to gamma radiation stress (방사선 스트레스 반응 방어 유전자의 탐색 및 발현 분석)

  • Park, Nuri;Ha, Hye-Jeong;Subburaj, Saminathan;Choi, Seo-Hee;Jeon, Yongsam;Jin, Yong-Tae;Tu, Luhua;Kumari, Shipra;Lee, Geung-Joo
    • Journal of Plant Biotechnology
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    • v.43 no.3
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    • pp.359-366
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    • 2016
  • Tradescantia is a perennial plant in the family of Commelinaceae. It is known to be sensitive to radiation. In this study, Tradescantia BNL 4430 was irradiated with gamma radiation at doses of 50 to 1,000 mGy in a phytotron equipped with a $^{60}Co$ radiation source at Korea Atomic Energy Research Institute, Korea. At 13 days after irradiation, we extracted RNA from irradiated floral tissues for RNA-seq. Transcriptome assembly produced a total of 77, 326 unique transcripts. In plantlets exposed to 50, 250, 500, and 1000 mGy, the numbers of up-regulated genes with more than 2-fold of expression compared that in the control were 116, 222, 246, and 308, respectively. Most of the up-regulated genes induced by 50 mGy were heat shock proteins (HSPs) such as HSP 70, indicating that protein misfolding, aggregation, and translocation might have occurred during radiation stress. Similarly, highly up-regulated transcripts of the IQ-domain 6 were induced by 250 mGy, KAR-UP oxidoreductase 1 was induced by 500 mGy, and zinc transporter 1 precursor was induced by 1000 mGy. Reverse transcriptase (RT) PCR and quantitative real time PCR (qRT-PCR) further validated the increased mRNA expression levels of selected genes, consistent with DEG analysis results. However, 2.3 to 97- fold higher expression activities were induced by different doses of radiation based on qRT-PCR results. Results on the transcriptome of Tradescantia in response to radiation might provide unique identifiers to develop in situ monitoring kit for measuring radiation exposure around radiation facilities.

A design of radiation hardened common signal processing module for sensors in NPP (내방사선 원전센서 공통 신호처리 모듈 설계)

  • Lee, Nam-ho;Hwang, Young-gwan;Kim, Jong-yeol;Lee, Seung-min
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.19 no.6
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    • pp.1405-1410
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    • 2015
  • In this study we designed the radiation-hardened sensor signal processing modules that can be commonly used for a variety of sensors during normal operation and even in high-radiation environments caused by an accident. First development module was designed to receive the change of the R and C value from the sensors and to process the signal as a PWM modulation scheme. This module was assessed to have ± 10% error to the Full-Scale in the radiation test in the range of 12 kGy TID. The main cause of the error was analyzed as the annealing of the common circuit in the switching element and the consequent increase in the duty ratio of the pulse width modulation circuit according to the radiation dose increasement. The redesigned module for higher radiation resistivity with Stub transistor circuit was found to have less than 5% error to the Full-scale from the radiation test results for 20.7 kGy TID range.