• Archives of Pharmacal Research
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• v.7 no.2
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• pp.95-99
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• 1984

Binding of sulfaethidole to bovine serum albumin (BSA) was studied by circular dichroism. The effects of pH and ionic strength on the binding of sulfaethidole to BSA were investigated. It was found that one primary binding site on the BSAM was capable of inducing optical activity in the presence of sulfaethidole. Enhancement of the induced ellipticity of sulfaethidole upon addition to BSA was not much affected by the change of pH and ionic strength. Taking the effects of pH and ionic strength into consideration, it seems that the binding of sulfaethidole to BSA was not much affected by electrostatic and ionic interactions. Therefore, it might be assumed that the binding was mainly due to the hydrophobic interactions. Sulfaethidole seems to be a reasonable CD probe for the study of hydrophobic drug interactions.

• Transactions of the Korean Society of Automotive Engineers
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• v.3 no.6
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• pp.78-86
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• 1995

The structure of premixed turbulent flames in a constant-volume vessel was investigated using a microprobe method. The flame potential signal having one to eight peaks was detected in the case of turbulent flames, each of them being regarded as a flamelet existing in the flame zone. Based on this consideration, the flame propagation speed, the thickness of the flame zone, the number of flamelets and the separation distance between adjacent flamelets in the flame zone were measured. The experimental resuits of this work suggest the existence of "reactant islands" behind the flame front when the turbulence was intensified to some extent. The critical(lowest) ratio of turbulence intensity to the laminar burning velocity being found to be about 0.7 for the formation of reactant islands in this experiment.

• Journal of Sensor Science and Technology
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• v.20 no.1
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• pp.40-45
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• 2011

Microcantilevers have been actively used in probe-based microscopy and gravimetric sensing for biological or chemical analytes. To integrate actuation or detection schemes in the structure, typical fabrication processes include several photolithographic steps along with conventional MEMS fabrication. In this paper, a simple and straightforward way to fabricate and operate silicon microcantilever mass sensors is presented. The fabricated microcantilever sensors which can be electrostatically actuated require only two photolithographic steps. Resonant characteristics of fabricated microcantilevers are measured with a custom optical-lever and results show size-dependent quality factors. Using a $40\;{\mu}m$ long, $7\;{\mu}m$ wide, and $3\;{\mu}m$ thick cantilever, we achieved subfemtogram mass resolution in a 1 Hz bandwidth.

• Journal of the Korean institute of surface engineering
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• v.32 no.4
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• pp.513-520
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• 1999

In this study, we investigated the effects of variously configured magnets on the characteristics of the plasmas to enhance plasma uniformity and density of an inductively coupled plasma source. As the magnets, Helmholtz type axial electromagnets and various multi-dipole magnets types around the chamber wall were used. To characterize the plasma as a function of the combination of the magnets and magnetic field strengths, ion density, electron temperature, and plasma potential were measured using an electrostatic probe along the chamber diameter for Ar plasmas. The measured maximum ion densities were $8$\times$10^{ 11}$$cm^{-3}$ with 600W inductive power and at 5mTorr of operational pressure and the uniformity of ion density was less than 5.9% at 2mTorr of operational pressure. The combination of an optimized multi-dipole magnet type and an axial electromagnet showed the lowest electron temperature (3eV) and plasma potential ($34V{p}$ )

• Bulletin of the Korean Chemical Society
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• v.7 no.5
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• pp.399-402
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• 1986

The critical micelle concentration (CMC) of sodium deoxycholate (NaDC) and the effects of amides on the micellization processes have been studied by fluorometric technique using pyrene as a probe. The addition of amides as cosolvent destabilized the NaDC micelle and increased the CMC. The order of effectiveness for the perturbation of NaDC micelle was N-methylacetamide ${\ge}$ DMF > acetamide > formamide, which is the order of hydrophobicity of the amines. This indicated that the effect of amides on the micellization processes of NaDC arises from diminution of the hydrophobic effect. The electrostatic repulsion between ionic head groups in the NaDC micelle appeared to be much less than that in aliphatic ionic micelle. This was also revealed in the weaker dependence of the CMC on ionic strength. The premicellar association of NaDC was not significantly involved in the micellization processes of the bile salt.

• Applied Microscopy
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• v.51
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• pp.8.1-8.7
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• 2021

Growing demands for comprehending complicated nano-scale phenomena in atomic resolution has attracted in-situ transmission electron microscopy (TEM) techniques for understanding their dynamics. However, simple to safe TEM sample preparation for in-situ observation has been limited. Here, we suggested the optical microscopy based micro-manipulating system for transferring TEM samples. By adopting our manipulator system, several types of samples from nano-wires to plate-like thin samples were transferred on micro-electro mechanical systems (MEMS) chip in a single step. Furthermore, the control of electrostatic force between the sample and the probe tip is found to be a key role in transferring process.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.2
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• pp.180-187
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• 2005

This paper is focused on the development of the flexible electrode for disc-type polymer actuators using Segmented Polyurethane(SPU). This paper consists of two parts. The one is about the mechanical property such as elastic modulus. these parameters mainly affect behaviors of polymer actuators and the other is about the electro-chemical property such as the surface resistance of the composite electrode affects the strength of electrostatic force, results in the deformation of polymer actuators. The Young's modulus was measured by UTM. As result, by increasing the modulus of a body of polymer actuators, the maximum displacement of polymer actuators are decreased. The surface resistance of the electrode was measured by 4 point probe system. Compared with the conductive silver grease, the displacement of polymer actuators using carbon black(CB) composite electrodes is comparably small but CB composite electrode should be the practical approach for the improvement of the performance of all-solid actuators, compared with another types of electrode materials.

• 한국정보디스플레이학회:학술대회논문집
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• 2000.01a
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• pp.85-87
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• 2000

In this study, high-density plasma etching characteristics of ITO(indium tin oxide) films used for transparent electrodes in display devices have been investigated. The etch characteristics of ITO as a function of $Ar/CH_4$ gas mixtures were analyzed using QMS(quadrupole mass spectrometry), OES(optical emission spectroscopy), and ESP(electrostatic probe). ITO etch rates were increased with the addition of moderate amount of $CH_4$ to Ar due to the increased chemical reaction between $CH_3$ or H and ITO in addition to the physical sputtering of ITO by Ar ion bombardment. However, the addition of excess amount of $CH_4$ decreased the ITO etch rates possibly due to the increased polymer formation on the ITO surface. Also, the measurement data obtained by QMS and OES suggested that $CH_3$ radicals are more activity involved in the etching of ITO compared to H radicals.

• Proceedings of the KIEE Conference
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• 1994.07b
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• pp.1589-1592
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• 1994

We developed the ion plating system, consisted of the Facing Target Magnetron Sputtering System and the r.f, electrode of the coil type, which was available to control the reactive and the adhesion between thin film and substrate, and studied about the discharge characteristics and the optimum condition in order to form the high quality thin film. The characteristics of discharge and plasma was measured as Double Probe and Electrostatic Retarding Grid Analyzer. The incident ion energy on the substrate was increased as the increasing r.f power, bias voltage. By the r.f electrode, the ionization rate of the sputtered particles was about 75%, and the mean incident ion energy depend on the value which was difference between the plasma potential and biased substrate potential.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2004.03a
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• pp.327-334
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• 2004

Spectroscopic and electrostatic probe measurements were made to examine plasma characteristics with or without a metal plate for a 10-㎾-class direct-current arcjet Heat fluxes into the plate from the plasma were also evaluated with a Nickel slug and thermocouple arrangement. Ammonia and mixtures of nitrogen and hydrogen were used. The NH$_3$ and $N_2$+3H$_2$ plasmas in the nozzle and in the downstream plume without a plate were in thermodynamical nonequilibrium states. As a result, the H-atom electronic excitation temperature and the $N_2$ molecule-rotational excitation temperature intensively decreased downstream in the nozzle although the NH molecule-rotational excitation temperature did not show an axial decrease. Each temperature was kept in a small range in the plume without a plate except for the NH rotational temperature for NH$_3$ gas. On the other hand, as approaching the plate, the thermodynamical nonequilibrium plasma came to be a temperature-equilibrium one because the plasma flow tended to stagnate in front of the plate. The electron temperature had a small radial variation near the plate. Both the electron number density and the heat flux decreased radially outward, and an increase in H$_2$ mole fraction raised them at a constant radial position. In cases with NH$_3$ and $N_2$+3H$_2$ a large number of NH radical with a radially wide distribution was considered to cause a large amount of energy loss, i.e., frozen flow loss, for arcjet thrusters.