• Journal of Environmental Science International
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• v.21 no.8
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• pp.901-907
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• 2012

The objective of this study was to evaluate bacteria removal ability of the metallic silver which was baked silver ion impregnated ceramic filter at heating condition. Silver leaking from baked ceramic filter was tested to sustain bacteria removal for a long time. Silver impregnated ceramic filter could remove E. coli completely at $10^{12}$ MPN/100ml to $10^{13}$ MPN/100ml of influent. However, ceramic filter without silver did not remove E. coli completely under the same condition. After baking, the silver impregnated ceramic filter almost didn't leak out the silver ion from filter. Photo of TEM (Transmission Electron Microscopy) showed that absorbed silver ions remained in ceramic filter after baking process and most of silver were less than 10 nm. According to the increase in the amount of silver in the ceramic filter, removal efficiencies of E. coli were increased but turbidity removal was decreased. It can be accounted that increased removal efficiency of E. coli was from disinfection of silver that is in the ceramic filter. Simulated concentrations of bacteria agree well with the observed experimental effluent concentration data. Moreover, first-order decay coefficients increased to 0.0034/min after silver was added in the ceramic filter. Increase of first-order decay coefficient proves that silver-added ceramic filter can remove bacteria easily.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11a
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• pp.418-421
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• 2001

The ceramic filters were developed using technology similar to that of quartz crystal and electro- mechanical filter. However, the key to this development involved the theoretical analysis of vibration modes and material improvements of piezoelectric ceramics. The primary application of ceramic filters has been for consumer-market use. Accordingly, a major emphasis has involved mass production technology, leading to low-priced devices. A typical ceramic filter includes monolithic resonators and capacitors packaged in unique configurations. Nakazawa developed a double-mode resonator as two acoustically coupled single resonators. And he developed 10.7MHz crystal filters using multi-energy trapping mode of thickness shear vibration. He succeeded in realizing a two-pole band pass filter response without external inductance by splitting a dot electrode to creak coupled symmetric and anti- symmetric vibration modes. Accordingly, the simulation for ceramic (inter were important. So that, this paper were investigated the pass frequency of filter on the electrode length and thickness of ceramic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1994.11a
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• pp.139-142
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• 1994

Ceramic filter using energy trapping pheonomenon is used bandpass filter at high frequency. In this paper, we analyzed theoretically ceramic filter characteristics of TS vibrational mode and also investigated experimentally it. The ceramic plate is PZT-4 poled in the thickness direction of Valpey Fisher Co. and electroded with two pairs. We analyzed the characteristics in appling to the all constant of ceramic and electrode material each other and vibrational mode. We also measured resonant frequency and bandpass width of the ceramic filter changing the thickness of ceramic plate and electrode spacing. Comparing of falter characteristics, theoretical value nearly corresponded with experimental value. So we saw that we can expect filter characteristics changing the thickness of ceramic plate and electrode spacing.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.3
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• pp.297-306
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• 2003

Works were focused on back pressure characteristics of ceramic fiber filter on DPF (Diesel Particulate Filter) system and experiments were performed to select appropriate filter which can filter particulates. Filters were installed on metal -support tube which has openings for exhaust gas flow. Ceramic fiber filters with high specific surface area and adequate high temperature strength are commercially available for filtration of diesel particulates and in -situ hot regeneration. Thus, ceramic blanket and ceramic board which are used as insulating media were applied to filter and filtration apparatus was installed on exhaust gas line connected to 2.0 L diesel engine. Alternating filter structure to adapt DPF system, collection efficiency test of diesel particulates was measured. In case of ceramic blanket, pressure drop was low, caused by the destruction of soft structures. Also, particulate collection efficiency was decreased depending on loading time. In case of ceramic board, structure design was altered to reduce back pressure on DPF system. Structure design was altered to induce Z-flow by making 10 mm and 5 mm holes on the surface of media. Alteration of 5 mm hole showed that media have low back pressure but particulate collection efficiency was 77%, while 10 mm hole showed that of 90%.

• Electrical & Electronic Materials
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• v.8 no.2
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• pp.144-150
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• 1995

Ceramic filter using energy trapping effect is used bandpass filter at high frequency. In this paper, the resonant points of the symmetrical modes and antisymmetrical modes were theoretically analyed and synthesized these modes in order to know the filter characteristics. We simulated them using the computer and also fabricated the ceramic filter using PZT-4 piezoelectric plate made by Valpey Fisher Co., The 1.5[.mu.m] - thick platinum electrode were deposited on the ceramic plates with the various masks. The characteristics of the fabricated filters were measured using the spectrum analyzer. Experimental data were compared with the theoretical results. The maximum-pass frequencies coinsided exactly. The bandwidths of the fabricated filters were slightly different between theoretical and experimental results. We found that these phenomenon were caused by the stray capacitance between the two neighbor electrodes..

• Journal of Korean Society for Atmospheric Environment
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• v.20 no.2
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• pp.185-193
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• 2004

A catalyst with CuO ceramic filter for simultaneous treatment of dust and HAP was prepared and characterized. Catalytic ceramic filter can not only potentially achieve the substantial savings in energy but provide with effective optimization and integration of process for simultaneous removal of SO$_2$, NO$_{x}$ and particulates from flue gases. Catalytic ceramic filters remove simultaneously particulates on exterior surface of filters and reduce NO to $N_2$ and $H_2O$ by SCR (Selective Catalytic Reduction) process. Preparation of catalyst impregnated ceramic filter with disk shape (Ψ 50) follow the processing of alumino-silicate ceramic filter, support impregnation and catalyst impregnation (copper oxide). Preparation routes of alumino-silicate catalyst carrier suitable for production of catalytic filters practically were studied and developed using the sol-gel and colloidal processing, homogeneous precipitation and impregnation method. Characterization of the catalyst, catalyst carrier catalytic filter materials have been performed the using various techniques such as BET, XRD, TGA, SEM. Combination of the sol-gel and colloidal processing and impregnation method is recommended to prepare catalyst carriers economically for catalytic filter applications.s.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.07b
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• pp.613-617
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• 2002

The ceramic filters were developed using technology similar to that of quartz crystal and electromechanical filter. However, the key to this development involved the theoretical analysis of vibration modes and material improvements of piezoelectric ceramics. The primary application of ceramic filters has been for consumer-market use. Accordingly, a major emhpasis has involved mass production technology, leading to low-priced devices. A typical ceramic filter includes monolithic resonators and capacitors packaged in unique configurations. Nakazawa developed a double-mode resonator as two acoustically coupled single resonators. And he developed 10.7MHz crystal filters using multi-energy trapping mode of thickness shear vibration. He succeeded in realizing a two-pole band pass filter response without external inductance by splitting a dot electrode to creat coupled symmetric and antisymmetric vibration modes. Accordingly, the simulation for ceramic filter were important. So that, this paper were investigated the pass frequency of filter on the electrode length and thickness of ceramic.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2001.11b
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• pp.418-421
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• 2001

The ceramic filters were developed using technology similar to that of quartz crystal and electromechanical filter. However, the key to this development involved the theoretical analysis of vibration modes and material improvements of piezoelectric ceramics. The primary application of ceramic filters has been for consumer-market use. Accordingly, a major emhpasis has involved mass production technology, leading to low-priced devices. A typical ceramic filter includes monolithic resonators and capacitors packaged in unique configurations. Nakazawa developed a double-mode resonator as two acoustically coupled single resonators. And he developed 10.7MHz crystal filters using multi-energy trapping mode of thickness shear vibration. He succeeded in realizing a two-pole band pass filter response without external inductance by splitting a dot electrode to creat coupled symmetric and antisymmetric vibration modes. Accordingly, the simulation for ceramic filter were important. So that, this paper were investigated the pass frequency of filter on the electrode length and thickness of ceramic.

• Proceedings of the KWS Conference
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• 2010.05a
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• pp.32-38
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• 2010

Hybrid material(ceramic+metal) processes were developed for micro filter using ceramics coating at metal filter surface by thermal spray method, micro hole drilling at ceramic coated filter surface by femtosecond laser, and fiber laser direct welding of ceramic and metal (SUS304, SM45C) by capillary effect. Thermal spray process was used for ceramic powders and metal filters. The used ceramic powders were $Al_2O_3+40TiO_2$(Metco 131VF) powder of maximum particle size $5{\mu}m$ and ${Al_2O_3}99+$(Metco 54NS) power of maximum particle size 45m. Ceramic coated filters using thermal spray method had a great influence on powder material, particle size and coating thickness but had a fine performance as a micro filter. CW fiber laser was used to drill the top ceramic layer and melt the bottom metal layer for joining applications.

• Environmental Engineering Research
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• v.10 no.5
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• pp.239-246
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• 2005

The effect of Pt addition over $V_2O_5-WO_3/TiO_2$ catalyst supported on PRO-66 was investigated for NO reduction in order to develop the catalytic filter working at low temperature. Catalytic filters, $Pt-V_2O_5-WO_3/TiO_2/PRD$, were prepared by co-impregnation of Pt, V, and W precursors on $TiO_2$-coated ceramic filter named PRD (PRD-66). Titania was coated onto the pore surface of the ceramic filter using a vacuum aided-dip coating method. The Pt-loaded catalytic filter shifted the optimum working temperature from $260-320^{\circ}C$(for the catalytic filter without Pt addition) to $190-240^{\circ}C$, reducing 700 ppm NO to achieve the $N_x$ slip concentration($N_x\;=\;NO+N_2O+NO_2+NH_3$) less than 20 ppm at the face velocity of 2 cm/s. $Pt-V_2O_5-WO_3/TiO_2$ supported on PRD showed the similar catalytic activity for NO reduction with that supported on SiC filter as reported in a previous study, which implies the ceramic filter itself has no considerable interaction for the catalytic activity.