• Title/Summary/Keyword: mesh filter

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Thickening of Excess Sludge using Mesh Filter (메쉬 여과모듈을 이용한 잉여슬러지 농축)

  • Jung, Yong-Jun;Kiso, Yoshiaki;Min, Kyung-Sok
    • Journal of Korean Society on Water Environment
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    • v.20 no.4
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    • pp.346-351
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    • 2004
  • Because of being produced a great deal of excess sludges from biological wastewater treatment process, the subject regarding treatment and disposal of them has been significantly handled in real plants. It should be considered the alternative treatment with easy operating and cost effective process in rural areas. For the thickening of wasted activated sludge from small scale wastewater treatment facilities, thus, the provisional sludge thickening system was developed by the application of mesh filter module. Three meshes with different pore size(100, 150, $200{\mu}m$) were prepared for filter modules that were used to withdraw effluent from thickening system. A filter module with $100{\mu}m$ mesh was chosen as the most effective thickening material in the viewpoint of volume reduction and effluent quality: the volume reductions of initially injected sludge with 3,600 mg/L and 9,100 mg/L were 95% and 85%, respectively, and the filtered effluents were enough good to be shown below 1.0 mg/L of SS and 1.0 NTU of turbidity. Since the filtration of thickening was influenced by the cake layer formed on mesh filter module and this system was operated in the combination of sludge thickening with gravity settling, the filter modules with smaller pore size and the larger floc size were required for long term operation safely.

Research and development of new magnetic filter for high gradient magnetic separation

  • Shigehiro Nishijima;Naoki Nomura;Fumihito Mishima
    • Progress in Superconductivity and Cryogenics
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    • v.25 no.3
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    • pp.1-6
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    • 2023
  • We have been developing a new magnetic filter so that small sized paramagnetic substances can be separated even in a low magnetic field (lower than 2T). The developed filter is a packed ferromagnetic filament with a triangular cross section. The filament has a diameter of 120 ㎛ and a length of 3 mm, and is mechanically packed with a volume ratio of 17.6%. Using this filter, a magnetic separation experiment of hematite was carried out using a superconducting magnet at the field of 2T. Similarly, magnetic separation was performed using a conventional magnetic filter. It became clear that the separation efficiency of newly developed filter is high as that of conventional mesh filter. The smaller sized hematite (<3 ㎛) could be separated though conventional mesh filter could not separate.

Shielding Effectiveness of Mesh Screen Filter of Plasma Display Panel

  • Lim, Heon-Yong;Kim, Min-Seok;Lee, Jeong-Hae
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.568-570
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    • 2004
  • A shielding effectiveness of mesh screen filter of plasma display panel (PDP) has been calculated in this paper. Since the screen filter is located near the radiation source, the near field wave impedance of the radiation source, i.e., the PDP electrodes, has been considered to calculate the shielding effectiveness. The near field shielding effectiveness of screen filter at 30${\sim}$300 MHz has been estimated to be more than 65${\sim}$80 dB. The measured shielding effectiveness of screen filter is 10${\sim}$50 dB at 30${\sim}$300 MHz[1]. The resulting discrepancy indicates that there are other EMI emission sources such as emission from PCB and cable besides the PDP electrodes.

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Classification of Nanoparticles by Inertial/Diffusion Filter (관성/확산필터를 이용한 나노입자의 분류기술 연구)

  • Kim, Yonggu;Lee, Sangyul;Kim, Hannah;Noh, Hakjae;Bong, Choonkeun;Kim, Daesung
    • Particle and aerosol research
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    • v.11 no.2
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    • pp.29-36
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    • 2015
  • The purpose of this research is to find out the collection property of nanoparticle in diffusion filter to know particle size dispersion of nanomaterial using inertial force and principle of Brownian diffusion motion. We used inertial filters which are two different type and diffusion filters made by various kinds of Wiremesh and the different pieces of filter to compare with particle size distribution using NaCl particles. Finally, We made a conclusion as follows : (1) the bigger available charging volume is and the larger specific surface area of inertial filter is, the better collection efficiency is. (2) The higher wire-mesh number of filter is, the more collection efficiency of small particle is increasing because the wire of the higher Wiremesh number filter is thinner and denser. (3) The more pieces of wire-mesh filter, the more collection efficiency is increasing because it makes the residence time longer.

An effective filtering for noise smoothing using the area information of 3D mesh (3차원 메쉬의 면적 정보를 이용한 효과적인 잡음 제거)

  • Hyeon, Dae-Hwan;Choi, Jong-Soo
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.44 no.2 s.314
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    • pp.55-62
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    • 2007
  • This paper proposes method to get exquisite third dimension data removing included noise by error that occur in third dimension reconstruction through camera auto-calibration. Though reconstructing third dimension data by previous noise removing method, mesh that area is wide is happened problem by noise. Because mesh's area is important, the proposed algorithm need preprocessing that remove unnecessary triangle meshes of acquired third dimension data. The research analyzes the characteristics of noise using the area information of 3-dimensional meshes, separates a peek noise and a Gauss noise by its characteristics and removes the noise effectively. We give a quantitative evaluation of the proposed preprocessing filter and compare with the mesh smoothing procedures. We demonstrate that our effective preprocessing filter outperform the mesh smoothing procedures in terms of accuracy and resistance to over-smoothing.

Measurements and Analysis of Electromagnetic Shielding Effectiveness of PDP TV Screen Filters (PDP TV Screen Filter의 Shielding Effectiveness 측정 및 분석)

  • Park, Gyu-Bok;Kim, Yoon-Jung;Kim, Young-Soo
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2003.11a
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    • pp.47-53
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    • 2003
  • Screen filter of PDP TV plays an important role in satisfying the EMI/EMC specifications. Two types of filters, the mesh type and the sputter type, are used in PDP TVs, and this paper presents measurement results of the shielding effectiveness (SE) in the frequency range from 50MHz to 1GHz. Two methods were used for the measurement, one using network analyzer (NA) in an open area test site(OATS), and the other using the screen room. The overall conclusion is that the shielding effectiveness of the screen filter is related to the surface resistance of the screen filter. The mesh type screen filters are superior to the sputter types in the shielding effectiveness, which is varying with the frequency.

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Noise reduction for mesh smoothing of 3D mesh data

  • Hyeon, Dae-Hwan;WhangBo, Taeg-Keun
    • International Journal of Contents
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    • v.5 no.4
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    • pp.1-6
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    • 2009
  • In this paper, we propose a mesh smoothing method for mesh models with noise. The proposed method enables not only the removal of noise from the vertexes but the preservation and smoothing of shape recognized as edges and comers. The magnitude ratio of 2D area and 3D volume in mesh data is adopted for the smoothing of noise. Comparing with previous smoothing methods, this method does not need many iteration of the smoothing process and could preserve the shape of original model. Experimental results demonstrate improved performance of the proposed approach in 3D mesh smoothing.

The Effect of Filter in the Static Charge Elimination Methodes for Streaming-Electrification Insulating Oil. (유동대전된 절연유의 제전방식중 필터에 의한 영향)

  • 정광현;김용운;신재화;김보열;이덕출
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1995.11a
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    • pp.361-364
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    • 1995
  • The static charges are generated by streaming electrification phenomena when insulating oil flowing by force for the purpose of cooling at the internal of Ultra-high power transformer. In this thesis, their elimination method was studied. The falter represents a greet much electrification characteristics because falter has large interfaces with liquid. In this paper, the streaming-electrification phenomena of insulating oil by metal filter were measured by mesh number, oil flow rate, oil temperature and a kind of mesh and The effect of charge elimination by metal filter generated minus ion was measured.

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A Subgrid scale model with a 3 -dimensional explicit filtering (3차원 외재적 필터링 을 이용한 SGS 모델)

  • Lee, Kyung-Seh;Baek, Je-Hyun
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.634-637
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    • 2008
  • A large eddy simulation with an explicit filter on unstructured mesh is presented. The flow filed is semi-implicitly marched by a fractional step method. Spatial discretization of the solver is designed to guarantee the second order accuracy. An isotropic explicit filter is adopted for measuring the level of subgrid scale velocity fluctuation. The filter is linearity-preserving and has second order commutation error. The developed subgrid scale model is basically eddy viscosity model which depends on the explicitly filtered fields and needs no additional ad hoc wall treatment, such as van Driest damping function. For the validation, the flows in a channel and a pipe are calculated and compared to experimental data and numerical results in the literature.

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