• 한국대기환경학회지
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• 제28권6호
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• pp.675-687
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• 2012

Applying an external electric field across air filter media is one of methods to improve the filtration performance. Metal wire meshes have been commonly used as electrodes situated on both sides of a thick filter pad. For a thin filter medium a short circuit, known as the biggest drawback for applying an external electric field to air filter, can occur at the closest point between electrodes. In this study several types of insulated meshes were prepared by coating #50 meshes with a dielectric material, Nylon 66, and the filtration property of air filter was evaluated at the presence of external electric field using those insulated meshes as electrodes and compared with that of filters using bared meshes. The collection efficiency of tested filter was increased from 78% to 95% for singly charged 100 nm particles by application of external electric field. As a result, there was no significant difference in collection efficiency between filters with insulated and bared electrodes. Similar results could be also seen from the tests using polydisperse particles. Finally, through this study, we found that the insulation of mesh electrodes doesn't affect the filtration performance of fibrous air filter under external electric field.

• Smart Structures and Systems
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• 제13권4호
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• pp.547-565
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• 2014

This paper investigates the design of a perfect point load actuator based on flat triangular piezoelectric patches. Applying a difference of electric potential between the electrodes of a triangular patch leads to point loads at the tips and distributed moments along the edges of the electrodes. The previously derived analytical expressions of these forces show that they depend on two factors: the width over height (b/l) ratio of the triangle, and the ratio of the in-plane piezoelectric properties ($e_{31}/e_{32}$) of the active layer of the piezoelectric patch. In this paper, it is shown that by a proper choice of b/l and of the piezoelectric properties, the moments can be cancelled, so that if one side of the triangle is clamped, a perfect point load actuation can be achieved. This requires $e_{31}/e_{32}$ to be negative, which imposes the use of interdigitated electrodes instead of continuous ones. The design of two transducers with interdigitated electrodes for perfect point load actuation on a clamped plate is verified with finite element calculations. The first design is based on a full piezoelectric ceramic patch and shows superior actuation performance than the second design based on a piezocomposite patch with a volume fraction of fibres of 86%. The results show that both designs lead to perfect point load actuation while the use of an isotropic PZT patch with continuous electrodes gives significantly different results.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.278.2-278.2
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• 2014

We have investigated the highly flexible and transparent Si-doped $In_2O_3$(ISO)/Ag/ISO multilayer grown on polyethylene terephthalate (PET) substrates using a roll-to-roll sputtering system. The electrical and optical properties of ISO/Ag/ISO multilayer electrodes depended on the insertion of a nano-size Ag layer. Due to the high conductivity of a nano-size Ag layer, the optimized ISO/Ag/ISO multilayer electrodes showed the lowest resistivity of $3.679{\times}10^{-5}Ohm-cm$, even though the ISO/Ag/ISO multilayer electrodes was sputtered at room temperature. Furthermore, the ISO/Ag/ISO multilayer electrodes exhibited a high transmittance of 86.33%, because of the anti-reflection effect, comparable to Sn-doped $In_2O_3$ (ITO) electrodes. In addition, the ISO/Ag/ISO multilayer electrodes had a very smooth surface morphology without surface defects and showed good flexibility. The flexible OSCs fabricated on ISO(30nm)/Ag(8nm)/ISO(30nm) multilayer electrode showed a power conversion efficiency of 3.272%. This result indicates that the ISO/Ag/ISO multilayer is a promising transparent conducting electrode for flexible OSCs.

• 패션비즈니스
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• 제21권2호
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• pp.78-90
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• 2017

In this study, brassiere prototype was developed for attaching the measuring module of ECG measurement and body movement while sleeping. For ECG measurement, textile electrodes was made of stretch fabric containing polyurethane in consideration of elasticity of brassiere band. It was used as a conductive yarn by silver coating on the warp. The textile electrodes was woven with twisted twill to increase the density of conductive yarns. The pressure of the brassiere band was enough to sensing stably the ECG, and the elastic band of the brassiere was designed to be wider than 3cm to install the textile electrodes inside, so that textile electrodes was close fitting to the skin at a constant pressure without lifting. The textile electrodes coated with silicon on rear was attached to brassiere elastic band, and the module was installed with a snap connector to textile electrodes of brassiere band. The module was suitable to monitering ECG measurement of a typical R peak, pulse rate and body movement while sleeping without interfering.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2011년도 제40회 동계학술대회 초록집
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• pp.65-65
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• 2011

We report the application of conducting metal oxide electrodes for semiconducting metal oxide gas sensors. Pt interdigitated electrodes have been commonly used for metal oxide gas sensor because of the low resistivity, excellent thermal and chemical stability of Pt. However, the high cost of Pt is an obstacle for the wide use of metal oxide gas sensors compared with its counterpart electrochemical gas sensors. Meanwhile, relatively low-cost conducting metal oxides are widely being used for light-emitting diodes, flat panel displays, solar cell and etc. In this work, we have fabricated $WO_3$ and $SnO_2$ thin film gas sensors using interdigitated electrodes of conducting metal oxides. Thin film gas sensors based on conducting metal oxides exhibited superior gas sensing properties than those using Pt interdigitated electrodes. The result was attributed to the low contact resistance between the conducting metal oxide and the sensing material. Consequently, we demonstrated the feasibility of conducting metal oxide interdigitated electrodes for novel gas sensors.

• 분석과학
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• 제8권4호
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• pp.669-674
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• 1995

The preparation and characterization of photosemiconductive electrodes of GaAs and of $Fe_2O_3$ doped with MgO or CaO were investigated. The doped $Fe_2O_3$ photosemiconductive electrodes were prepared from thin films sintered at temperatures from 1,100 to $1,450^{\circ}C$, and rapidly quenched in distilled water. The surfaces of the electrodes containing both corundum structure of $Fe_2O_3$ and spinel structure of $Mg_xFe_{3-x}O_4$ or $Ca_xFe_{3-x}O_4$ were analyzed by X-ray diffraction and scanning electron microscopy. The cathodic and anodic photocurrents on these electrodes indicated a critical doping amount of 5-11 wt. %. The photocurrents were enhanced when GaAs electrodes were treated with methylene violet the anodic photo-currents were temporarial enhanced and changed to the cathodic ptotocurrents after the surface was dryed.

• 공업화학
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• 제31권5호
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• pp.552-559
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• 2020

Activated carbon-nickel (II) oxide (AC-NiO) electrodes were studied as materials for the capacitive deionization (CDI) of aqueous sodium chloride solution. AC-NiO electrodes were fabricated through physical mixing and low-temperature heating of precursor materials. The amount of NiO in the electrodes was varied and its effect on the deionization performance was investigated using a single-pass mode CDI setup. The pure activated carbon electrode showed the highest specific surface area among the electrodes. However, the AC-NiO electrode with approximately 10 and 20% of NiO displayed better deionization performance. The addition of a dielectric material like NiO to the carbon material resulted in the enhancement of the electric field, which eventually led to an improved deionization performance. Among all as-prepared electrodes, the AC-NiO electrode with approximately 10% of NiO gave the highest salt adsorption capacity and charge efficiency, which are equal to 7.46 mg/g and 90.1%, respectively. This finding can be attributed to the optimum enhancement of the physical and chemical characteristics of the electrode brought by the addition of the appropriate amount of NiO.

• Journal of Electrochemical Science and Technology
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• 제8권2호
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• pp.124-132
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• 2017

The performance of electrolytic processes using copper and catalyzed electrodes for enhanced nutrient removal with various catalyzers and combinations of electrodes was evaluated. The catalyzed electrodes removed more ammonia nitrogen than the copper electrode, but higher ammonia removal was achieved using a Pt/Ti anode. On the other hand, electrolysis using the Pt/Cu anode consumed less energy and cost less. During electroreduction, nitrate was better removed by a pair of copper electrodes than by the catalyzed electrodes. During electrolysis of synthetic wastewater, ammonia removal not only increased owing to direct oxidation at the anode, but was also influenced by indirect oxidation at the cathode. Platinum-coated copper and titanium cathodes actively produced oxidizers and thus removed more ammonia than a pure metal cathode. Although phosphorus was removable irrespective of the type of catalyzer, electrocoagulation using the copper electrode achieved complete removal of phosphorus in a period of less than 10 min.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제50권2호
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• pp.79-85
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• 2001

A conventional electrolyzing cell has been made by an ion exchange membrane inbetween parallel plate electrodes. A low dc voltage is applied to the electrodes for electrolyzing and the efficiency is remained in low. in this study, a novel electrolyzing cell with a pair of slit-type third electrodes installed inbetween parallel plate electrodes has been proposed and investigated experimentally. And pulse power wa supplied to between each electrodes. This slit type of third electrodes can concentrate the strong electric fields at the every its edges to accelerate the electrolyzing powers, and to generate oxygen bubble discharges for generating oxidants. And moreover the slits eliminate the space charge limiting action and the temperature of the water by leaking out through the slits from electrolyzing region to outside of the main electrode region. As a result, it was found that a strong electorzed water of pH 2.8 and pH 10.5 and oxidants dissolved water of 1 [ppm] in acidic water were obtained with a tap water fed at the electric current of 2 [A], which however were several times higher oxidant and ion concentration quantity compared with the conventional cell.

• 전기학회논문지
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• 제58권5호
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• pp.1050-1056
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• 2009

Heart Rate Variability(HRV) is a parameter that represents monitoring variability of time intervals between R-peak in electrocardiography. HRV serves to various applications, such as indices of autonomic functions, prediction of cardiac sudden death, assessment of stress and emotional, etc. However, as measuring R-peak in ECG needs at least 3-electrodes, and it is inconvenient for end users. In this paper, we suggested the modified laplacian electrodes for measuring HRV at one-point, which are producted by MEMS fabrication and have the two circular electrodes on the pad. For optimal position and direction, we performed an experiment that compared with pearson correlation coefficient and the amplitude of signals, between standard lead II and proposed electrodes. We analyzed the HRV parameters, such as standard deviation of the NN interval(SDNN), high frequency(HF), low frequency(LF), LF/HF ratio. The result showed that the average correlation coefficient and amplitude are 0.967 and 0.685 mVpp at the position 2. The coeffiecient correlation between the standard HRV and proposed electrode-HRV is 0.999