• Title, Summary, Keyword: Electric probe

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Low-ε Static Probe Development for 15N-1H Solid-state NMR Study of Membrane Proteins for an 800 MHz NB Magnet

  • Park, Tae-Joon;Choi, Sung-Sub;Jung, Ji-Ho;Park, Yu-Geun;Kim, Yongae
    • Bulletin of the Korean Chemical Society
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    • v.34 no.3
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    • pp.823-826
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    • 2013
  • A low-${\varepsilon}$ solid-state NMR(Nuclear Magnetic Resonance) probe was developed for the spectroscopic analysis of two-dimensional $^{15}N-^1H$ heteronuclear dipolar coupling in dilute membrane proteins oriented in hydrated and dielectrically lossy lipid environments. The system employed a 800 MHz narrow-bore magnet. A solenoid coil strip shield was used to reduce deleterious RF sample heating by minimizing the conservative electric fields generated by the double-tuned resonator at high magnetic fields. The probe's design, construction, and performance in solid-state NMR experiments at high magnetic fields are described here. Such high-resolution solid-state NMR spectroscopic analysis of static oriented samples in hydrated phospholipid bilayers or bicelles could aid the structural analysis of dilute biological membrane proteins.

Development of New DNA Chip and Genome Detection Using an Indicator-free Target DNA (비수식화 DNA를 이용한 유전자 검출 및 새로운 DNA칩의 개발)

  • Park, Yong-Sung;Park, Dae-Hee;Kwon, Young-Soo;Tomoji Kawai
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.52 no.8
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    • pp.365-370
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    • 2003
  • This research aims to develop an indicator-free DNA chip using micro-fabrication technology. At first, we fabricated a DNA microarray by lithography technology. Several probe DNAs consisting of thiol group at their 5-end were immobilized on the gold electrodes. Then indicator-free target DNA was hybridized by an electrical force and measured electrochemically in potassium ferricyanide solution. Redox peak of cyclic-voltammogram showed a difference between target DNA and mismatched DNA in an anodic peak current. Therefore, it is able to detect various genes electrochemically after immobilization of various probe DNAs and hybridization of indicator-free DNA on the electrodes simultaneously It suggested that this DNA chip could recognize the sequence specific genes.

Fabrication of High Aspect Ratio Micro Structure for fine pitch probe production (Fine pitch probe 제작을 위한 고세장비 마이크로 구조물 제작)

  • Lee, S.I.;Kim, W.K.;Pyo, C.R.;Kim, D.Y.;Yang, S.J.;Ko, K.H.;Kim, H.J.;Jeon, B.H.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • pp.356-359
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    • 2007
  • Continuing improvements in integrated circuit chip density and functionality have mostly contributed toward a very large-scale integrated circuit(VLSI) and display device. In order to test (pass or fail) all of the high integrated semiconductor chip and display device, fine pitch probes are used. Fine pitch probes are manufactured by electroforming process of a Ni alloy in an electrolytic bath. In this paper, we expect that the electric field in bath with the Finite Element Method and applying the FEM result. So, we can obtained the probes that have high aspect ratio of 10 : 1

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CONDUCTIVITIES OF SEA-BOTTOM SEDIMENTS

  • HoWoongShon
    • Journal of the Korean Geophysical Society
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    • v.6 no.2
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    • pp.79-87
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    • 2003
  • An in-situ four-electrode contact resistivity probe system was designed, and field-tested in submarine sediments. Seismic survey was also performed to support and compare the results of electric survey. The probe was designed to be driven to selected depths below the seafloor using a Vibracore system. The four insulated electrodes were, spaced equidistant across the wedge, were extended beyond the probe tip to minimize effects of sediment disturbance by the wedge insertion. In-situ measurements of resistivity were recorded on board by precision electronic equipment consisting of signal generators and processors, and by temperature- monitoring systems. Overall limits of uncertainty at respective depths below the seafloor are up to ±10% of the measured values. Best estimates of conductivity are considered to be ±3 percent of the reported values. Resistivity measurements were made at six sites in carbonate sediments to a maximum depth of penetration of about 5 m. Average values of conductivity range between 0.88 and 1.21 mho/m. The results show the seabed is composed of alternating layers of relatively high-conductivity material (0.8 to 1.4 mho/m) in thicknesses of more or less one meter and layers about 30 cm thick having relatively low conductivities (0.4 to 0.8 mho/m).

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Write Characteristics of Silicon Resistive Probe

  • Jung, Young-Ho;Kim, Jun-Soo;Shin, Hyung-Cheol
    • Proceedings of the IEEK Conference
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    • pp.821-824
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    • 2005
  • Probe storage is one of the strong candidates for future mobile storage device since it has potential of recording density over I $Tb/in^2$ with r/w speed over 100 Mbps. It also uses silicon-processing technology that suits the purpose of small form factor. In this paper, write characteristics of resistive probe that can rotate the field direction of PZT by field-induced resistance changes in a small resistive region at the apex of the tip will be presented. Also, the relationship between the size of tip and the available write width is investigated for different source bias conditions. For this study, two-dimensional computer simulation ($SILVACO^{TM}$) was performed. With optimum design, the width of the writing electric field can be smaller than 50nm

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Polarization State of Scattered Light in Apertureless Reflection-mode Scanning Near-Field Optical Microscopy

  • Cai, Yongfu;Aoyagi, Mitsuharu;Emoto, Akira;Shioda, Tatsutoshi;Ishibashi, Takayuki
    • Journal of Magnetics
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    • v.18 no.3
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    • pp.317-320
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    • 2013
  • We studied the polarization state in an apertureless scanning near-field microscopy (a-SNOM) operating in reflection mode by using three-dimensional Finite-difference Time-domain (FDTD) method. As a result, the electric field around tip apex in the near-field region enhanced four times stronger than the incident light for ppolarization when the tip-sample separation was 10 nm. We find that the p- and s-polarization state is maintained for the scattered light when the probe is perpendicular to the sample. When the probe is not perpendicular to the sample, the polarization state of scattered light will rotate an angle that equals to the inclination angle of probe with p-polarization illumination. On the other hand, the polarization state will not rotate with s-polarization illumination.

Development of 600-MHz 19F-7Li Solid-State NMR Probe for In-Situ Analysis of Lithium Ion Batteries

  • Jeong, Ji-Ho;Park, Yu-Geun;Choi, Sung-Sub;Kim, Yongae
    • Bulletin of the Korean Chemical Society
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    • v.34 no.11
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    • pp.3253-3256
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    • 2013
  • Lithium is a highly attractive material for high-energy-concentration batteries, since it has low weight and high potential. Rechargeable lithium-ion batteries (LIBs), which have the extremely high gravimetric and volumetric energy densities, are currently the most preferable power sources for future electric vehicles and various portable electronic devices. In order to improve the efficiency and lifetime, new electrode compounds for lithium intercalation or insertion have been investigated for rechargeable batteries. Solid-state nuclear magnetic resonance (NMR) is a very useful tool to investigate the structural changes in electrode materials in actual working lithium-ion batteries. To detect the in-situ microstructural changes of electrode and electrolyte materials, $^7Li-^{19}F$ double-resonance solid-state NMR probe with a static solenoidal coil for a 600-MHz narrow-bore magnet was designed, constructed, and tested successfully.

Corrosion Monitoring for Offshore Wind Farm's Substructures by using Electrochemical Noise Sensors

  • Soh, Joon-Young;Lee, Min-Woo;Kim, Su-Kyung;Kim, Do Hyung
    • KEPCO Journal on Electric Power and Energy
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    • v.2 no.4
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    • pp.615-618
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    • 2016
  • Electrochemical noise(EN) has been used to analyze the deterioration of coating films of offshore wind substructures. In this study, prototype sensors using EN have been developed to detect the corrosion rate. To verify the reliability of sensors, experiments were conducted both in the laboratory and offshore using probe and standard samples. New analysis and data processing techniques show that the sensor can provide useful information about the corrosion rate.

Performance Evaluation of Non-contact Atomic Force Microscopy Due to Vibration Characteristics of Cantilever (비접촉 원자간력 현미경의 탐침 외팔보 진동특성에 따른 성능 평가)

  • 박준기;권현규;홍성욱
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.263-268
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    • 2003
  • This paper presents a result of performance evaluation fur non-contact scanning probe microscopy with respect to the vibration characteristics of cantilevers with tips. One of the current issues of the scanning probe microscopy technology is to increase the measurement speed, which is closely tied with the dynamic characteristics of cantilevers. The primary concern in this research is to investigate the relation between the maximum possible speed of non-contact scanning probe microscopy and the dynamic characteristics of cantilevers. First, the finite element analysis is made fur the vibration characteristics of various cantilevers in use. The computed natural frequencies of the cantilevers are in good agreement with measured ones. Then, each cantilever is tested with topographic measurement for a standard sample with the scanning speed changed. The performances of cantilevers are analyzed along with the natural frequencies of cantilevers. Experiments are also performed to test the effects of how to attach cantilevers in the piezo-electric actuator. Finally, measurement sensitivity has been analyzed to enhance the performance of scanning probe microscopy.

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Vibration Characteristics and Performance of Cantilever for Non-contact Atomic Force Microscopy (비접촉 원자간력 현미경의 탐침 캔틸레버 진동 특성 및 측정 성능 평가)

  • 박준기;권현규;홍성욱
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.6
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    • pp.495-502
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    • 2004
  • This paper presents the vibration analysis and the performance evaluation of cantilevers with probing tips for non-contact scanning probe microscopy. One of the current issues of the scanning probe microscopy technology is to increase the measurement speed, which is closely tied with the dynamic characteristics of cantilevers. The primary concern in this research is to investigate the relation between the maximum possible speed of non-contact scanning probe microscopy and the dynamic characteristics of cantilevers. First, the finite element analysis is made for the vibration characteristics of various cantilevers in use. The computed natural frequencies of the cantilevers are in good agreement with measured ones. Then, each cantilever is tested with topographic measurement for a standard sample with the scanning speed changed. The performances of cantilevers are analyzed along with the natural frequencies of cantilevers. Experiments are also performed to test the effects of how to attach cantilevers in the piezo-electric actuator. Finally, measurement sensitivity has been analyzed to enhance the performance of scanning probe microscopy.