• 제목/요약/키워드: $O_2$ sensor

검색결과 1,271건 처리시간 0.028초

Spinel Nanoparticles ZnCo2O4 as High Performance Electrocatalyst for Electrochemical Sensing Antibiotic Chloramphenicol

  • Van-Cuong Nguyen;HyunChul Kim
    • Journal of Electrochemical Science and Technology
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    • 제15권1호
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    • pp.152-160
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    • 2024
  • In this study, ZnCo2O4 nanoparticles were synthesized via the coprecipitation method using different annealing temperatures from 200℃ to 800℃. By varying the treatment temperature, the morphology changed from amorphous to tetragonal, and finally to polygonal particles. As temperature increased, the sizes of the nanoparticles also changed from 5 nm at 200℃ to approximately 500 nm at 800℃. The fabricated material was used to modify the working electrode of a screen-printed carbon electrode (SPE), which was subsequently used to survey the detection performance of the antibiotic, chloramphenicol (CAP). The electrochemical results revealed that the material exhibits a good response to CAP. Further, the sample that annealed at 600℃ displayed the best performance, with a linear range of 1-300 μM, and a limit of detection (LOD) of 0.15 μM. The sensor modified with ZnCo2O4 also exhibited the potential for utilitarian application when the recovery in a real sample was above 97%.

소성 조건에 따른 WO$_3$계 후막센서소자의 제조 및 응답특성 (Fabrication and Gas Sensing Properties of WO$_3$Thick Film Gas Sensor Dependent on Heat-Treatment Condition)

  • 정용근;엄우식;이희수;최성철
    • 마이크로전자및패키징학회지
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    • 제6권2호
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    • pp.63-68
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    • 1999
  • 가스 감지막의 미세구조와 비화학량론 구조의 변화에 따른 응답특성의 거동을 고찰하기 위하여 소성 조건을 변화시키면서 $WO_3$후막형 가스센서를 제조하였다. 소자는 감지물질인 $WO_3$분말과 유기 용제를 균일하게 혼합한 페이스트를 Au전극과 $RuO_2$발열체가 입혀진 알루미나 기판 위에 스크린 프린팅 방법으로 제조하였다. 소성 조건을 변화시키기 위하여 600-$800^{\circ}C$ 온도범위하에서 1시간 동안 열처리 하였고, Ar과 $O_2$가스의 비율을 변화시키면서 $700^{\circ}C$에서 1시간 재열처리하였다. 열처리 결과, 소성 온도 $700^{\circ}C$에서 제조된 $WO_3$가스센서 소자가 가스감도 210, 응답속도 2초로 가장 좋은 특성을 보였으며 Ar과 $O_2$가스의 비율이 40-50%의 소성 분위기에서 가스 감도가 가장 높게 나타났다.

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센서-구조 일체형 복합재료 구조물 제작 방법 (Manufacturing Method for Sensor-Structure Integrated Composite Structure)

  • 한대현;강래형
    • Composites Research
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    • 제28권4호
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    • pp.155-161
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    • 2015
  • 본 연구는 복합재료 구조물에 전기-기계 변환 기능을 융합한 센서-구조 일체형 복합재료 구조물 제작 방법에 관한 것으로 복합재료 구조물 자체가 센서 역할을 수행할 수 있도록 하여 구조 스스로 충격이나 진동 신호를 감지하고 손상 위치 또는 손상 정도를 실시간으로 모니터링 할 수 있는 다기능 복합 구조물에 관한 연구이다. 복합재 구조물에 전기-기계 변환 기능을 부여하기 위해 복합재 제작에 사용되는 에폭시 수지 대신 전기-기계 변환기능을 갖는 $Pb(Ni_{1/3}Nb_{2/3})O_3-Pb(Zr,\;Ti)O_2$ (PNN-PZT) 분말과 에폭시 수지를 1:30 wt% 혼합하여 제작된 스마트 수지를 사용하였다. Hand Lay-up 공법과, VARTM(Vacuum Assisted Resin Transfer Molding) 성형 방법을 이용하여 유리섬유에 스마트 수지를 함침시켜 센서-구조 일체형 복합재료 구조물을 제작하였다. 구조물을 센서로 사용하기위해 시편의 윗면과 아랫면에 전도성 도료를 사용하여 전극을 제작하였고, 고전압 앰프를 이용하여 상온에서 30분간 4kV/mm의 전계로 분극 처리를 수행하였다. 이후 충격망치를 사용하여 시편에 충격을 가했을 때 출력되는 전기 신호와 충격망치 신호를 비교하여 충격 신호 감응 및 감도를 측정하고 그 결과를 기술하였다.

전기방사방법에 의해 합성된 ZnO 중공 나노섬유의 trimethylamine 가스 감응 특성 (Trimethylamine Sensing Characteristics of Molybdenum doped ZnO Hollow Nanofibers Prepared by Electrospinning)

  • 김보영;윤지욱;이철순;박준식;이종흔
    • 센서학회지
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    • 제24권6호
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    • pp.419-422
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    • 2015
  • Pure and Mo-doped ZnO hollow nanofibers were prepared by single capillary electrospinning and their gas sensing characteristics toward 5 ppm ethanol, trimethylamine (TMA), CO and $H_2$ were investigated. The gas responses and responding kinetics were dependent upon sensing temperature and Mo doping. Mo-doped ZnO hollow nanofibers showed high response to 5 ppm TMA ($R_a/R_g=111.7$, $R_a$: resistance in air, $R_g$: resistance in gas) at $400^{\circ}C$, while the responses of pure ZnO hollow nanofibers was low ($R_a/R_g=47.1$). In addition, the doping of Mo enhanced selectivity toward TMA. The enhancement of gas response and selectivity to TMA by Mo doping to ZnO nanofibers was discussed in relation to the interaction between basic analyte gas and acidic additive materials.

나노 SnO2:CNT를 이용한 가스센서의 제작 및 특성연구 (Characteristics and Preparation of Gas Sensors Using Nano SnO2:CNT)

  • 유일
    • 한국재료학회지
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    • 제26권9호
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    • pp.468-471
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    • 2016
  • $SnO_2:CNT$ thick films for gas sensors were fabricated by screen printing method on alumina substrates and were annealed at $300^{\circ}C$ in air. The nano $SnO_2$ powders were prepared by solution reduction method using tin chloride ($SnCl_2.2H_2O$), hydrazine ($N_2H_4$) and NaOH. Nano $SnO_2:CNT$ sensing materials were prepared by ball-milling for 24h. The weight range of CNT addition on the $SnO_2$ surface was from 0 to 10 %. The structural and morphological properties of these sensing material were investigated using X-ray diffraction and scanning electron microscopy and transmission electron microscope. The structural properties of the $SnO_2:CNT$ sensing materials showed a tetragonal phase with (110), (101), and (211) dominant orientations. No XRD peaks corresponding to CNT were observed in the $SnO_2:CNT$ powders. The particle size of the $SnO_2:CNT$ sensing materials was about 5~10 nm. The sensing characteristics of the $SnO_2:CNT$ thick films for 5 ppm $H_2S$ gas were investigated by comparing the electrical resistance in air with that in the target gases of each sensor in a test box. The results showed that the maximum sensitivity of the $SnO_2:CNT$ gas sensors at room temperature was observed when the CNT concentration was 8wt%.

Selective acetate detection using functional carbon nanotube fiber

  • Choi Seung-Ho;Lee, Joon-Seok;Choi, Won-Jun;Lee, Sungju;Jeong, Hyeon Su;Choi, Seon-Jin
    • 센서학회지
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    • 제30권6호
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    • pp.357-363
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    • 2021
  • We developed a chemiresistive anion sensor using highly conductive carbon nanotube fibers (CNTFs) functionalized with anion receptors. Mechanically robust CNTFs were prepared via wet-spinning utilizing the nematic liquid crystal properties of CNTs in chlorosulfonic acid (CSA). For anion detection, polymeric receptors composed of dual-hydrogen bond donors, including thiourea 1, squaramide 2, and croconamide 3, were prepared and bonded non-covalently on the surface of the CNTFs. The binding affinities of the anion receptors were studied using UV-vis titrations. The results revealed that squaramide 2 exhibited the highest binding affinity toward AcO-, followed by thiourea 1 and croconamide 3. This trend was consistent with the chemiresistive sensing responses toward AcO- using functional CNTFs. Selective anion sensing properties were observed that CNTFs functionalized with squaramide 2 exhibited a response of 1.08% toward 33.33 mM AcO-, while negligible responses (<0.1%) were observed for other anions such as Cl-, Br-, and NO3-. The improved response was attributed to the internal charge transfer of dual-hydrogen bond donors owing to the deprotonation of the receptor upon the addition of AcO-.

YBaCuO계 초전도소결체 자기소자 (Preparation of Magnetic Field Sensor with YBaCuO Superconducting Ceramics)

  • 이상헌
    • 한국초전도저온공학회:학술대회논문집
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    • 한국초전도저온공학회 2000년도 KIASC Conference 2000 / 2000년도 학술대회 논문집
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    • pp.109-111
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    • 2000
  • A magnetic field sensor is fabricated with superconducting ceramics of Y-Ba-Cu-O system. The prepared material shows the superconductivity at about 95K. The sensor at liquid nitrogen temperature shows the increase in electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor is changed from zero to a value more than 100$\mu$V by the applied magnetic field. The change in electrical resistance depends on magnetic field. The sensitivity of this sensor is 2.9 ohm/T. The sensing limit is about $1.5\times$$10^{-5}$ (=1.5$\times$$10^{-1}$ G). The increase in electrical resistance by the magnetic field is ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material.

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Blind Signal Processing for Wireless Sensor Networks

  • Kim, Namyong;Byun, Hyung-Gi
    • 센서학회지
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    • 제23권3호
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    • pp.158-164
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    • 2014
  • In indoor sensor networks equalization algorithms based on the minimization of Euclidean distance (MED) for the distributions of constant modulus error (CME) have yielded superior performance in compensating for signal distortions induced from optical fiber links, wireless-links and for impulsive noise problems. One main drawback of MED-CME algorithms is a heavy computational burden hindering its implementation. In this paper, a recursive gradient estimation for weight updates of the MED-CME algorithm is proposed for reducing the operations $O(N^2)$ of the conventional MED-CME to O(N) at each iteration time for N data-block size. From the simulation results of the proposed recursive method producing exactly the same results as the conventional method, the proposed estimation method can be considered to be a reliable candidate for implementation of efficient receivers in indoor sensor networks.

BPSCCO 자기 효과 (Magnetic Characteristics of BiPbSrCaCuO Oxide Superconductor)

  • 이상헌;이성갑;이영희
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 추계학술대회 논문집 Vol.16
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    • pp.252-254
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    • 2003
  • A magnetic field sensor is fabricated with superconducting ceramics system. The sensor at liquid nitrogen temperature shows the increase in electrical resistance by applying magnetic field. Actually, the voltage drop across the sensor is changed from zero to a value more than $100{\mu}V$ by the applied magnetic field. The change in electrical resistance depends on magnetic field. The sensitivity of this sensor is 2.9 ohm/T. The increase in electrical resistance by the magnetic field is ascribed to a modification of the Josephson junctions due to the penetrating magnetic flux into the superconducting material.

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