• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.475-482
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• 2020

For electronic paper displays using electrophoresis, the response time and reflectivity of the image panel fabricated by filtering are analyzed. For the filtering process, a square wave and ramp wave are applied to white charged particles with a unique q/m value. We divide the sample panels into #1 to #4 according to the applied waveform in the filtering process. Step waves comprising two steps are used to drive the panel; therefore, we divide the driving conditions into D1~D4. The applied voltage at the first stage of the half cycle of the driving waveform moves the charged particles attached via the image force from the electrode, and the applied voltage at the second stage moves the floating charged particles by detaching. As mentioned, four types of driving conditions (D1 to D4) classified according to the half cycle of the driving waveform are applied to the samples #1 to #4), which are classified according to four types of filtering process. When driving condition D1 is applied to the four types of sample panels, the rise time of #1 is 1.59s, #2 is 1.706s, #3 is 1.853s, and #4 is 1.235s, resulting in #4 being relatively faster compared with other sample panels, and showing the same trend in other driving conditions. As a result, we confirm that applying the driving condition D1 causes abrupt movement of the white charged particles injected into the cell. When the same driving waveform (D1) is applied to each sample, reflectivities of 32.1% for #1, 31.4% for #2, 27.9% for #3, and 63.4% for #4 are measured. From the experiment, we confirm that the driving condition D1 (1s of 3.5 V, 9s of 3.0 V) and ramp wave #4 in filtering are desirable for good reflectivity and response time. Our research is expected to contribute to the improvement of the filtering process and optimization of the driving waveform.

• 정보저장시스템학회:학술대회논문집
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• 2005.10a
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• pp.75-80
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• 2005

Study for toner adhesion is known as an important role in electrophotography. In this research, a centrifugal detachment method was used to measure the adhesion force of several hundred particles simultaneously and to determine its sensitivity to particle size. For uncharged toner particles, we estimated the van der Waals force based on the centrifugal farce experiments. Then for charged toner particles, the centrifugal force experiments were carried out. The difference between the results for charged toner particles and the results for uncharged toner particles was compared with the image force calculated from a model which assumed that the toner charge was located at the center of the particle. In the calculations, experimental data obtained by E-SPART (Electrical- Single Particle Aerodynamic Relaxation Time) analyzer were used. The adhesion force of micro-sized toner particles deposited on the DR surface was found to be approximately 1${\~}$3 nN.

• Transactions of the Society of Information Storage Systems
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• v.2 no.2
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• pp.105-110
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• 2006

Study for toner adhesion is 3non as an important role in electrophotography. In this research, a centrifugal detachment method was used to measure the adhesion force of several hundred particles simultaneously and to determine its sensitivity to particle size. For uncharged toner particles, we estimated the van der Waals force based on the centrifugal force experiments. Then for charged toner particles, the centrifugal force experiments were carried out. The difference between the results for charged toner particles and the results for uncharged toner particles was compared with the image force calculated from a model which assumed that the toner charge was located at the center of the particle. In the calculations, experimental data obtained by E-SPART (Electrical-Single Particle Aerodynamic Relaxation Time) analyzer were used. The adhesion force of micro-sized toner particles deposited on the DR surface was found to be approximately $1{\sim}3$ nN.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.1
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• pp.46-52
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• 2013

After an outbreak of viral disease in an aquafarm, release of virus (es) from infected fish into environmental seawater has been suspected. In the present study, we utilized a negatively charged membrane (HA type) as an efficient method for concentration and detection of fish pathogenic viruses, specifically, megalocytivirus and viral hemorrhagic septicemia virus (VHSV) present in field-collected seawater samples or inoculated into seawater artificially. Positively charged viruses adsorbed onto the negatively charged membrane and were eluted with 1 mM NaOH (pH 10.5) following rinsing with 0.5 mM $H_2SO_4$ (pH 3.0). Megalocytivirus and VHSV particles isolated using anegatively charged HA membrane from seawater inoculated with each virus at a concentration of 10 viral particles/mL were of sufficient quantity to show positive results in atwo-step PCR (or RT two-step PCR); however, despite it being negatively charged, a cellulose acetate (CA) membraneshowed negative results. In quantitative PCR, the detection limits of the HA membrane for megalocytivirus and VHSV in seawater were 1.20E+00 viral particles/mL and 1.22E+01 viralparticles/mL, respectively. The calculated mean recovery yields from 1 L seawater spiked with known concentrations of megalocytivirus and VHSV particles were 28.11% and 23.00%, respectively. The concentrate of a 1-L sample of culturing seawater from the aquatank of flounder suffering from VHSV showed clear positive results in PCR when isolated with an HA, but not a CA, membrane. Thus, viral isolation using an HA membrane is a practical and reliable method for detection of fish pathogenic viruses in seawater.

• 한국정보디스플레이학회:학술대회논문집
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• 2004.08a
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• pp.966-970
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• 2004

Electrophoretic display has recently stimulated tremendous interest due to potential commercialization in the filed of information displays including e-books, e-newspapers, and other low-power portable displays. A new transparent soft mold press (TSMP) process developed in this study was found to give a good electrophoretic display panel with prepatterned micropools for the filling of charged particle slurry. It was also found that charged $TiO_2$ particles with 74.09 mV of zeta potential and 3.11 ${\times}$ $10^{-5}$ $cm^2$/Vs of mobility were successfully prepared.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.41 no.2
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• pp.185-191
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• 1992

In this paper, it is attempted to distinguish the charged particles and to judge the polarity by the use of Thermally Stimulated Current(TSC) and Temperature Gradient Thermally Stimulated Surface Potential Measurement(TG-TSSP)with experimental insulation material XLPE-EVA for power cables which is made by blending cross-linked polyethylene(XLPE) and ethylene-vinylacetate copolymer(EVA). In addition, it is performed to investigate the effect of EVA blending. From the experimental results, it is known that for the case of XLPE-EVA blended experimental material, the generation of space charged electric field is not obtained in the high temperature region due to the obatruction of the injection of trapping carrier by the electron and the positive hole.

• 한국정보디스플레이학회:학술대회논문집
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• 2005.07a
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• pp.423-425
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• 2005

Reflective paper-like display (PLD) using two types of particles having different electric polarity has been developed. A positive-charged particle has $TiO_2$, polymer and charge control agent (CCA), while a negative-charged particle consists of carbon black, polymer and CCA. We achieved fast response time (${\sim}0.2$ msec) and passive matrix driving addressing. These methods can easily be adapted to complete a large area display and flexible display.

• Structural Engineering and Mechanics
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• v.42 no.6
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• pp.783-797
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• 2012

A new hybrid meta-heuristic optimization algorithm is presented for design of structures. The algorithm is based on the concepts of the charged system search (CSS) and the particle swarm optimization (PSO) algorithms. The CSS is inspired by the Coulomb and Gauss's laws of electrostatics in physics, the governing laws of motion from the Newtonian mechanics, and the PSO is based on the swarm intelligence and utilizes the information of the best fitness historically achieved by the particles (local best) and by the best among all the particles (global best). In the new hybrid algorithm, each agent is affected by local and global best positions stored in the charged memory considering the governing laws of electrical physics. Three different types of structures are optimized as the numerical examples with the new algorithm. Comparison of the results of the hybrid algorithm with those of other meta-heuristic algorithms proves the robustness of the new algorithm.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.22 no.10
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• pp.844-849
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• 2009

The moving behavior of particle with voltage biasing is studied by analyzing the displacement current generated in electrodes and the drift current by moving particles in cell gap. These currents are ascertained by optical reflectivity on the panel. We obtained the saturated current after a peak in threshold voltage which is coincide with reflectivity of 80%. These saturated optical reflectivity and its drift current offer optimum q/m of particles and driving voltage and can be analytically studied on grey scale methods. Especially regional analysis is useful to aging and driving voltage and the understanding of operating mechanism of charged particle type display.

• Journal of Korean Society for Atmospheric Environment
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• v.21 no.2
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• pp.145-153
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• 2005

An electret fiber with a dipole charge distribution was used to capture charged ultrafine particles in this study. Brownian diffusion and Coulombic force are the dominant collection mechanisms in the electret filtration of charged ultrafine particles. The interaction between Brownian diffusion and Coulombic force for the deposition of ultrafine particles onto a dipolarly charged fiber is studied by solving the convective diffusion equation including Coulombic force as an external force, and the numerical results are compared with the experimental data. As a result, it is shown that there is a negative interaction between Brownian diffusion and Coulombic force, i.e., Coulombic capture efficiency is reduced with decreasing Pe. These results suggest that Brownian diffusion and Coulombic capture efficiency, $\eta$$_{CD}$ is not a simple sum of Brownian diffusion efficiency, $\eta$$_{D}$ and Coulombic capture efficiency, $\eta$$_{C}$.