• Journal of Korean Society of Environmental Engineers
• /
• v.36 no.11
• /
• pp.753-757
• /
• 2014

Anode electrode in a microbial fuel cell (MFC) should transfer the receiving electron as well as provide large surface area that can be immobilized microorganisms. Microorganisms' population is one of important factors to improve the current generation and to treat the livestock wastewater by biological treatment. These studies were attempted to investigate if stainless-steel wire skein (SSWS) could be used as anode electrode replacement a graphite felt electrode in microbial fuel cell. For these studies, pretreated livestock wastewater was used diluted to 500 mg/L as COD before use. At this time, the current showed a little difference of about 5% when using each of a SSW and graphite felt (control). There was no significant difference in the current value. The organic removal rate in the microbial fuel cells used graphite felt and SSWS was 82.4% and 88.3%, respectively. The COD removal in the MFC used the SSWS was higher than that of graphite felt. Ammonium nitrogen was showed similar trend in two case all. These results about current generation and organic matter reduction seem possible that SSWS was used to anode electrode. When SSWS is used, the initial investment for system construction is expected to be able to reduce by approximately 1/50.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2003.10a
• /
• pp.118-118
• /
• 2003

In a rolling wire probe, a key component of an inspection apparatus for PDP electrode patterns, the electric performance of it is known to be strongly dependent on the surface condition of a collet pin, a needle pin, and a wire. However, the collet and needle pins rotate very rapidly in contact with each other, which results in the degradation of the surface by the heat and friction and finally the formation of black wear marks on the surface after a several hundred hours test. Once the black wear marks appear on the surface, the electric resistance of the probe increases sharply and so the integrity of the probe is severely damaged. In this experiment, TiN coating, which has excellent electric conductances and good wear-resistance, has been applied on the surface of collect and needle pins for preventing the surface damages. In order to achieve the homogeneous coating with a good adhesion property, special coating substrate stages and jigs were designed and applied during coating. TiN has been deposited using 99.999% Titanium target by a DC reactive sputtering method. According to the components and jigs, processing parameters, such as DC power, RF bias and the flow rate ratio of Ar and N$_2$ used as reactive gases, has been controlled to obtain good TiN films. Detailed problems and solutions for applying the new substrate stages and jigs will be discussed.

• Journal of Electrical Engineering and Technology
• /
• v.6 no.4
• /
• pp.556-562
• /
• 2011

In the present study, a simple corona-wire charger for unipolar diffusion charging of aerosol particles is designed, constructed, and characterized. Experimental characterizations of the electrostatic discharge in terms of current-voltage relationships of positive and negative coronas of the corona-wire charger are also presented and discussed. The charging current and ion concentration in the charging zone increased monotonically with corona voltage. The negative corona showed higher current than the positive corona. At the same corona voltages, the current in the discharge zone is about 600 times larger than the charging current. The ion number concentrations ranged within approximately $5.0{\times}10^{10}$ to $1.24{\times}10^{16}$ and $4.5{\times}10^{12}$ to $2{\times}10^{16}$ ions/$m^3$ in the discharge and charging zones, respectively. A numerical model is used to predict the behavior of the electric potential lines. Numerical results of ion penetration through the inner electrode are in good agreement with the experimental results.

• Proceedings of the KIEE Conference
• /
• 1999.07e
• /
• pp.2182-2185
• /
• 1999

In this experimental study we propose the double dielectric barrier discharge(DDBD) reactor to produce as high an electric field as possible. DDBD reactor is designed to remove $NO_x$ at atmospheric pressures from the moving pollution source such as diesel automobile DDBD reactor consisted of two cylinder glass tubes arranged so that the gas flow was directed between the two tubes. Inside of the inner tube was filled with small metal beads and outside of the inner tube was wounded with stainless wire to form the electrode. The outer tube was surrounded by an aluminum foil In this reactor there are three electrodes, i.e. metal bead(C), helical wire(I) and aluminum foil(0). By using DDBD reactor we will report some interesting results of treatment of the gas which is the dilute mixtures of NO in N2. And then we compared thee results with the results of cylinder-wire(CW) which is one of popularly used reactor in non-thermal plasma applications.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.12 no.11
• /
• pp.963-971
• /
• 2000

In order to investigate the effects of an electric field on EHD(Electro-hydrodynamic) nucleate boiling hat transfer characteristics in a nonuniform electric field under saturated pool boiling, the basic study has been performed experimentally. In the present study, the working fluid is R-113 and the plate-wire electrode system is used to generate a steep electric field gradient. Boiling parameters are investigated by using a high speed camera. The electric field distribution around a wire is obtained to understand the effect of an electric field on bubble departure/movement. The experimental results show EHD effects are much more considerable when the applied voltage increases. Bubbles depart away from the heated wire in radial direction. It is confirmed that the mechanisms of EHD nucleate boiling are closely connected with the dynamic behavior of bubbles. The boiling parameters are significantly changed by the electric field strength. With increasing applied voltages, the bubble size decreases and the nucleation site density, bubble velocity and bubble frequency increase.

• The Journal of Korean Physical Therapy
• /
• v.7 no.1
• /
• pp.61-67
• /
• 1995

The silver cation has broad-spectrum antibiotic activity toward Gram-positive, Gram-negative, fungal. aerobic and anerobic micro-organisms. Silver has been used to care of infected wound. pyogenic arthritis, and chronic osteomyelitis. The purpose of this study was to determine whether pure silver wire iontophoresis using milliamperage direct current has an inhibitory effect on growth in vitro of 3 different species of bacteria-Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Using agarose based media, silver iontophoresis performed at 0, 1, 2, 4, 8 mA for 15 minutes. All experiments were performed in triplicate. Following iontophoresis, inhibition zone width of bacterial growth was measured with calliper. The inhibition of bacterial growth occured at the anodal silver electrode. Inhibition zone width of bacterial growth was significantly increased in all three bacterial species (p<0.05). Between bacterial species, inhibition zone width was not significantly different. Inhibition gone and amperage showed a highly significant positive linear relationship (p<0.001). The result of this study showed that pure silver wire iontophoresis with milliamperage direct current, as well as microamperage direct current, can inhibit bacterial growth in vivo.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2002.10a
• /
• pp.218-222
• /
• 2002

Micro-EDM is generally used far machining micro holes, pockets, and 3-D structures. For micro-EDM, first of all, micro-electrode fabrication is needed and WEDC system is proposed for tool electrode fabrication method. When tool electrode is fabricated using WEDG system, its characteristics are under the control of many EDM parameters. Also relations between the parameters affect electrode fabrication. In this study, experiments are carried out to analyze effects of EDM parameters about electrode surface integrity on micro-electrode fabrication. Experimental method and analysis are used to experimental design method. Factors used in experiments are composed of capacitance, resistance, pause time, wire feed rate, spindle rotating speed. As a result of experiments, capacitance and resistance affect electrode surface.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.6 no.4
• /
• pp.130-137
• /
• 1997

The demand for wire-cut EDM is increasing rapidly in the die and tool making industry. In this study machining characteristics such as machining rate, surface roughness, hand drum form and hardness of machined material are investigated experimentally under the conditions varing pulse on time, pulse off time, peak voltage, wire tension after fixing other conditions in SKD 11 and brass and brass workpiece. It was found that various operating conditions had significant influences on machining characteristics. But the hardness of workpiece was uneffected by operating conditions. Also it was obtained experimentally that brass workpeice had better machinability than SKD 11 one.dition according to the current(Ip) in an electric spark machine : 1) Electrode is utilized Cu and Graphite. 2) Work piece is used the material of carbon steel. The condition of experiment is : 1) Current is varied 0.7(A) to 50(A) and the time of electric discharging to work piece in each time is 30(min) to 60(min). 2) After the upper side of work piece was measured in radius(5$\mu$m) of stylus analyzed the surface roughness to ade the table and graph of Rmax by yielding data. 3) Electro wear ratio is : \circled1Cooper was measured ex-machining and post-machining by the electronic balance. \circled2The ex-machining of graphite measured by it, the post-machining was found the data from volume $\times$specific gravity and analyzed to made its table and graph on ground the data. 4) In order to keep the accuracy of voltage affected to the work piece was equipped with the A.V. R and the memory scope was sticked to the electric spark machine. 5) In order to preserve the precision of current, to get rid of the noise occured by internal resistance of electric spark machine and to force injecting for the discharge fluid , it made the fixed table for a work piece to minimize the work error by means of one's failure during the electric discharging.

• Proceedings of the KIEE Conference
• /
• 2007.04b
• /
• pp.85-87
• /
• 2007

This paper summarize about the auxiliary electrode measured a ground resistance The method to measure a ground resistance is the fall-of-potential method to using an auxiliary electrode. And an auxiliary electrode must be set up on the ground. Today it is so difficult to set up the auxiliary electrode on the ground because of many concrete building and many paved roads. So this paper is regarding of the ground resistance measurement by the substitute auxiliary electrode. It substituted a iron structure around the building, a wire net for auxiliary electrode. This information is confirmed by compared with the measurement value.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.9
• /
• pp.57-63
• /
• 2007

The occurrence of a corona is that electrical discharge due to the heterogeneity that occurs when an electrical field is concentrated in an electrode due to a cusp formed on said electrode. Wire treatment at the end of a 154[kV] dead end clamp for end users accelerates the occurrence of corona, which in turn leads to power loss and noise. In this study, the characteristics of the corona which occurs between porcelain insulators and support clamps of overhead lines used in 154[kV] power receiving facilities for end users were investigated. The corona, which cannot be identified by one common method, was measured utilizing a UV image camera. A risk assessment for fire damage and its status was suggested. The stress distribution of the electrical field by length of bare wire was suggested by means of the finite element method(FEMLAB). As a result, it was found to affect a porcelain insulators. These results can be utilized for the enhancement of clamp installation and safety in power facilities.