• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.8
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• pp.1031-1039
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• 1999

Electrospraying comprises the generation of liquid droplets by applying a high voltage to the surface of a liquid. By monitoring the current and the flow rate it was possible to obtain a stable cone jet mode in a given condition. In this work the liquid contained NaCl particles resolved in distilled water. The NaCl particles increased concentration of the ionized solution and thus increased electrical conductivity of the liquid, which was inversely proportional to the flow rate in the cone jet mode. A number of sprayed droplets were sampled and dried enough, and then the size of NaCl particles were measured. The measured droplet diameter was a little larger than two theoretical diameters, Rayleigh diameter and mobility diameter.

• 한국신재생에너지학회:학술대회논문집
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• 2007.06a
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• pp.323-325
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• 2007

$TiO_{2}$ electrode electrospun directly onto the substrate was developed for energy conversion device. To enhance energy conversion efficiency of dye-sensitized solar cell, electrodes should have higher surface area to absorb more dyes and higher conductivity to reduce recombination of generated electrons. $TiO_{2}$ nanofibers with higher surface areas were fabricated by annealing electrospun $TiO_{2}/PVP$ nanofibers at $500^{\circ}C$ for 3 hrs in air. it was revealed that $TiO_{2}$ nanofiber electrodes is hybrid with MWNT showed higher conductivity than $TiO_{2}$ semiconductor electrode possibly due to band gap change.

• Macromolecular Research
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• v.13 no.3
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• pp.194-205
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• 2005

The network structure of Ni-coated carbon black (NCB) composites filled with phenolic resin was investigated by means of using scanning electron microscopy, viscosity, interfacial tension, shrinkability, Flory-Huggins interaction parameters, and swelling index. The electrical properties of the composites have been characterized by measurement of the specific conductivity as a function of temperature. Additionally, the variation of conductivity with temperature for the composites has been reported and analyzed in terms of the dilution volume fraction, relative volume expansion, and barrier heights energy. The thermal stability of phenolic-NCB composites has been also studied by means of the voltage cycle processes. The experimental data of EMI wave shielding were analyzed and compared with theoretical calculations. The mechanical properties such as tensile strength, tensile modulus, hardness and elongation at break (EB) of NCB-phenolic resin composites were also investigated.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1095-1096
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• 2006

When $Y_2O_3$ was added to Ti-excess $BaTiO_3$ ((Ba+Y)/Ti =1), the area occupied by $Y^{3+}$ ion was confirmed by its microstructure development, electrical conductivity behavior and lattice constant. Grain growth inhibition was observed when the content of donor dopant exceeded a critical value ($x{\approx}.0.01$) in $BaTiO_3+x(0.5Y_2O_3+TiO_2)$ system. A donor-doped behavior was observed at various Y contents ($0.2\sim3.0$ mol% Y) when $Y_2O_3$ was added to $TiO_2$-excess $BaTiO_3$. As Y content was increased, (002) and (200) peaks shifted to higher angles and the lattice constant (a and c axis) decreased gradually.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2011.04a
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• pp.113-116
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• 2011

A total of 9 coating specimens were fabricated through 3 different processes to evaluate the availability and performance of a nickel/chrome coating for the protection of the inner wall of a thrust chamber operating on a condition of high temperature and pressure. Thickness and thermal conductivity of the specimens were measured and thermal shock test was conducted.

• Journal of applied mathematics & informatics
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• v.41 no.3
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• pp.487-510
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• 2023

We propose a mathematical model which describes the frictional contact between a piezoelectric body and an electrically conductive foundation. The behavior of the material is described with a linearly electro-viscoelastic constitutive law with long term memory. The mechanical process is dynamic and the electrical conductivity coefficient depends on the total slip rate, the friction is modeled with Tresca's law which the friction bound depends on the total slip rate with taking into account the electrical conductivity of the foundation both. The main results of this paper concern the existence and uniqueness of the weak solution of the model; the proof is based on results for second order evolution variational inequalities with a time-dependent hemivariational inequality in Banach spaces.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.5
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• pp.213-213
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• 2003

We investigated the monolayer behavior at the air-water interface with metal solution, the surface morphologies and the electrical properties such as conductivity, The calculated conductivity values of pure water subphase and its complexes with L $i^{+}$ ions are 5.6$\times$10$^{-l6}$ and 1.9$\times$10$^{-14}$ [S/cm], respectively. And the calculated barrier height D values of pure water subphase and its complexes with Li. ions are 0.70 and 0.66 [eV], respectively. We also attempted to fabricate a crown dendrimer Langmuir-Blodgett (LB) films containing functional end group that could form a complex structure with metal ions. Also, we investigated the surface activity of dendrimer films at air-water interface. In AFM images. the larger domains irregularly shaped structures on the top while the smaller ones were free from such defects. In conclusion, it is demonstrated that the metal ion around dendrimer and polymer included crown function group can contribute to make formation of network structure among crown function group and result in change of electrical properties.s.s.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.52 no.5
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• pp.213-218
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• 2003

We investigated the monolayer behavior at the air-water interface with metal solution, the surface morphologies and the electrical properties such as conductivity, The calculated conductivity values of pure water subphase and its complexes with L $i^{+}$ ions are 5.6$\times$10$^{-l6}$ and 1.9$\times$10$^{-14}$ [S/cm], respectively. And the calculated barrier height D values of pure water subphase and its complexes with Li. ions are 0.70 and 0.66 [eV], respectively. We also attempted to fabricate a crown dendrimer Langmuir-Blodgett (LB) films containing functional end group that could form a complex structure with metal ions. Also, we investigated the surface activity of dendrimer films at air-water interface. In AFM images. the larger domains irregularly shaped structures on the top while the smaller ones were free from such defects. In conclusion, it is demonstrated that the metal ion around dendrimer and polymer included crown function group can contribute to make formation of network structure among crown function group and result in change of electrical properties.s.s.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.14
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• pp.5595-5597
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• 2015

Electrical impedance tomography (EIT) is a new non-invasive, mobile screening method which does not use ionizing radiation to the human breast. It is based on the theory that cancer cells display altered local dielectric properties, thus demonstrating measurably higher conductivity values. This article reviews the utilisation of EIT in breast cancer detection. It could be used as an adjunct to mammography and ultrasonography for breast cancer screening.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2000.11a
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• pp.302-306
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• 2000

In case of applying electrokinetic remediation, magnitude of electric current is one of major factors for estimation of contaminant transport. In practice, electric current provide determination of electric conductivity based on specimen resistance. Electric current variation is produced during Electrokinetic remediation test. Electric current is decreased by expotential function according to time in condition of constant voltage. This can be interpreted as precipitation effect by OH$^{-10}$ generation in a cathode.