• Title/Summary/Keyword: Electrostatic Probe

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Protein Binding Characteristics of Brazilin and Hematoxylin

  • Moon, Chang-Kiu;Lee, Jong-Hwoa;Ha, Bae-Jin
    • Journal of Food Hygiene and Safety
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    • v.7 no.2
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    • pp.77-82
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    • 1992
  • In order to investigate the protein binding characteristics of braD6n and hematoxy6n to bovine semm albumin (BSA), the fluorescence probe method was adopted. Brazilin and hematoxy6n showed strong binding affinity for BSA. It was also confirmed that hematoxy6n was bound to BSA stronger than braDlin. The association constants were decreased by the elevation of concentrations of brazilin and hematoxylin. It might be due to the complex formation of the probe and both compounds or the interaction between the probe-protein complex and both compounds. The bindings between both compounds and BSA were dependent on pH and ionic strength. It seems that electrostatic force as weD as hydrophobic force is involved in the binding of braD6n and bematoxylin to BSA.

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Electrostatically-Driven Polysilicon Probe Array with High-Aspect-Ratio Tip for an Application to Probe-Based Data Storage (초소형 고밀도 정보저장장치를 위한 고종횡비의 팁을 갖는 정전 구동형 폴리 실리콘 프로브 어레이 개발)

  • Jeon Jong-Up;Lee Chang-Soo;Choi Jae-Joon;Min Dong-Ki;Jeon Dong-Ryeol
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.6 s.183
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    • pp.166-173
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    • 2006
  • In this study, a probe array has been developed for use in a data storage device that is based on scanning probe microscope (SPM) and MEMS technology. When recording data bits by poling the PZT thin layer and reading them by sensing its piezoresponse, commercial probes of which the tip heights are typically shorter than $3{\mu}m$ raise a problem due to the electrostatic forces occurring between the probe body and the bottom electrode of a medium. In order to reduce this undesirable effect, a poly-silicon probe with a high aspect-ratio tip was fabricated using a molding technique. Poly-silicon probes fabricated by the molding technique have several features. The tip can be protected during the subsequent fabrication processes and have a high aspect ratio. The tip radius can be as small as 15 nm because sharpening oxidation process is allowed. To drive the probe, electrostatic actuation mechanism was employed since the fabrication process and driving/sensing circuit is very simple. The natural frequency and DC sensitivity of a fabricated probe were measured to be 18.75 kHz and 16.7 nm/V, respectively. The step response characteristic was investigated as well. Overshoot behavior in the probe movement was hardly observed because of large squeeze film air damping forces. Therefore, the probe fabricated in this study is considered to be very useful in probe-based data storages since it can stably approach toward the medium and be more robust against external shock.

Study on the Structural Design of an Ultra-miniaturized Microcolumn with a Built-in Electrostatic Octupole Stigmator (정전형 8중극 비점수차 보정기가 내장된 극초소형 마이크로컬럼의 구조 설계 연구)

  • Tae Sik Oh
    • Journal of the Semiconductor & Display Technology
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    • v.22 no.3
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    • pp.52-61
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    • 2023
  • We designed a novel ultra-miniaturized microcolumn structure having an stigmator to significantly improve throughput per unit time, which is the biggest disadvantage of microcolumns. We adopted the structure of the stigmator in the form of an electrostatic octupole electrode, and used an electrostatic quadrupole deflector with a relatively simple structure considering the increase in wiring due to the introduction of the stigmator. We have dramatically reduced the effect of astigmatism that occurs when the electron beam probe is scanned to the periphery of the target by introducing the stigmator between the control electrode and the deflector. As our numerical analysis simulation results, the field of view obtained as a result of this study is about 46.3% improved compared to our previous study, and the electron beam probe size of less than 10 nm was achieved in the entire field of view.

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Measurements of the Burning Velocities of Flamelets in a Turbulent Premixed Flame

  • Furukawa, Junichi;Noguchi, Yoshiki;Hirano, Toshisuke;Williams, Forman A.
    • Journal of the Korean Society of Combustion
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    • v.6 no.2
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    • pp.65-70
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    • 2001
  • To investigate statistics of flamelet in a turbulent premixed flame and to obtain components of their burning velocities in a vertical plane above a pipe-flow burner, the local motion of flamelets with respect to gas are measured by specially arranged diagnostics, composed of an electrostatic probe with four identical sensors and a two-color four-beam LDV system. With this technique, the three-dimensional local flame-front-velocity vector is measured by the electrostatic probe for the first time, and simultaneously the axial and radial components of the local gas-velocity vector in a vertical plane above the vertically oriented burner are measured by the LDV system. Two components of burning velocities of planar flamelets can be obtained from these results and are found to be distributed over different directions and to range in magnitude from nearly zero to a few times the planar, unstrained adiabatic laminar burning velocity measured in the unburnt gas. It may be concluded from these results that turbulence exerts measurable influences on flamelets and causes at least some of them to exhibit increased burning velocity.

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Measurements of the Burning Velocities of Flamelets in a Turbulent Premixed Flame

  • Furukawa, Junichi;Noguchi, Yoshiki;Hirano, Toshisuke;Williams, Forman A.
    • Journal of the Korean Society of Combustion
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    • v.7 no.2
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    • pp.62-68
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    • 2002
  • To investigate statistics of flamelet in a turbulent premixed flame and to obtain components of their burning velocities in a vertical plane above a pipe-flow burner, the local motion of flamelets with respect to gas are measured by specially arranged diagnostics, composed of an electrostatic probe with four identical sensors and a two-color four-beam LDV system. With this technique, the three-dimensional local flame- front-velocity vector is measured by the electrostatic probe for the first time, and simultaneously the axial and radial components of the local gas-velocity vector in a vertical plane above the vertically oriented burner are measured by the LDV system. Two components of burning velocities of planar flamelets can be obtained from these results and are found to be distributed over different directions and to range in magnitude from nearly zero to a few times the planar, un strained adiabatic laminar burning velocity measured in the unburnt gas. It may be concluded from these results that turbulence exerts measurable influences on flamelets and causes at least some of them to exhibit increased burning velocity.

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Study of Carbon Nanotubes by Electrostatic Force Microscopy (EFM(electrostatic force microscopy)를 이용한 탄소나노튜브의 연구)

  • Park Hoon;Seo Yu-Suk;Hong Jin-Soo;Chae Hee-Baik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.1
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    • pp.12-16
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    • 2005
  • We used electrostatic force microscopy to probe carbon nanotubes. There is a linear relationship between the phase shift (${\Delta}{\phi}^{-l/2}$) and the inverse tube length ($L^{-1}$) of carbon nanotubes. When the distance(h) between the tip and the carbon nanotubes increase, the phase shift on EFM image decrease by a factor of $1/h^2$

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Application of Optical Receiving Probe in Combustion Field (연소장에서의 광학식 수광프로브의 적용)

  • Yang, Young-Joon
    • Journal of Sensor Science and Technology
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    • v.13 no.5
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    • pp.335-341
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    • 2004
  • A light collecting probe named Multi-colored Integrated Receiving Optics (MICRO) is experimentally examined to verify its performance. For these purposes, the time-series signals of MICRO probe is compared with those of electrostatic probe and light-guided probe by monitoring, for example, such as OH radical chemiluminescence, CH radical band and droplet Mie scattering. In addition, the experiment was conducted by using laminar premixed Bunsen flame, turbulent premixed Bunsen flame and premixed spray flame, respectively. It was confirmed that the performance of MICRO probe was very useful and convenient to obtain the chemiluminescence signals from local regions in turbulent premixed Bunsen flame and premixed spray flame.

Advanced atomic force microscopy-based techniques for nanoscale characterization of switching devices for emerging neuromorphic applications

  • Young-Min Kim;Jihye Lee;Deok-Jin Jeon;Si-Eun Oh;Jong-Souk Yeo
    • Applied Microscopy
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    • v.51
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    • pp.7.1-7.9
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    • 2021
  • Neuromorphic systems require integrated structures with high-density memory and selector devices to avoid interference and recognition errors between neighboring memory cells. To improve the performance of a selector device, it is important to understand the characteristics of the switching process. As changes by switching cycle occur at local nanoscale areas, a high-resolution analysis method is needed to investigate this phenomenon. Atomic force microscopy (AFM) is used to analyze the local changes because it offers nanoscale detection with high-resolution capabilities. This review introduces various types of AFM such as conductive AFM (C-AFM), electrostatic force microscopy (EFM), and Kelvin probe force microscopy (KPFM) to study switching behaviors.