• Title/Summary/Keyword: separation techniques

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Synthesis and characterization of poly(vinyl-alcohol)-poly(β-cyclodextrin) copolymer membranes for aniline extraction

  • Oughlis-Hammache, F.;Skiba, M.;Hallouard, F.;Moulahcene, L.;Kebiche-Senhadji, O.;Benamor, M.;Lahiani-Skiba, M.
    • Membrane and Water Treatment
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    • v.7 no.3
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    • pp.223-240
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    • 2016
  • In this study, poly(vinyl-alcohol) and water insoluble ${\beta}$-cyclodextrin polymer (${\beta}$-CDP) cross-linked with citric acid, have been used as macrocyclic carrier in the preparation of polymer inclusion membranes (PIMs) for aniline (as molecule model) extraction from aqueous media. The obtained membranes were firstly characterized by X-ray diffraction, Fourier transform infrared and water swelling test. The transport of aniline was studied in a two-compartment transport cell under various experimental conditions, such as carrier content in the membranes, stirring rate and initial aniline concentration. The kinetic study was performed and the kinetic parameters were calculated as rate constant (k), permeability coefficient (P) and flux (J). These first results demonstrated the utility of such polymeric membranes for environmental decontamination of toxic organic molecules like aniline. Predictive modeling of transport flux through these materials was then studied using design of experiments; the design chosen was a two level full factorial design $2^k$. An empirical correlation between aniline transport flux and independent variables (Poly ${\beta}$-CD membrane content, agitation speed and initial aniline concentration) was successfully obtained. Statistical analysis showed that initial aniline concentration of the solution was the most important parameter in the study domain. The model revealed the existence of a strong interaction between the Poly ${\beta}$-CD membrane content and the stirring speed of the source solution. The good agreement between the model and the experimental transport data confirms the model's validity.

Separation and Identification of Antimicrobial Compounds from Korean Leek (Allium tuberosum) (부추의 항균활성 물질의 분리)

  • Hong, Jeong-Hwa;Lee, Mi-Hyung;Kang, Min-Chul;Hur, Sung-Ho
    • Journal of Food Hygiene and Safety
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    • v.15 no.3
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    • pp.235-240
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    • 2000
  • Various separation techniques of antimicrobial compounds from food materials have proven to be ineffective, involving liquid-liquid extraction and chromatography. We established efficient separation procedure for partially purifying antimicrobial compounds from Korean leek. Separation procedures consisted of ultrafiltration, liquid-liquid extraction, TLC and HPLC. Molecular weight of antimicrobial compounds were less than 5,000 dalton. Major compounds were propenyl methyl disulfide, S-methyl methylthiosulphonate and dimethyl disulfide.

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Development of dielectrophoresis chips and an electrode passivation technique for isolation/separation of nanoparticles (나노 입자 분리/분류를 위한 유전영동 칩 및 전극 패시베이션 기술 개발)

  • Park, Minsu;Noh, Hyowoong;Kang, Jaewoon;Lee, Junyeong;Park, Hongsik
    • Journal of Sensor Science and Technology
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    • v.30 no.2
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    • pp.119-124
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    • 2021
  • Isolation and separation of biological nanoparticles, such as cells and extracellular vesicles, are important techniques for their characterization. Dielectrophoresis (DEP) based on microfluidic chips is an effective method to isolate and separate the nanoparticles. However, the electrodes of the DEP chips are electrolyzed by the electrical signals applied to the nanoparticles. Thus, the isolation/separation efficiency of the nanoparticles is reduced considerably. Through this study, we developed a microfluidic DEP chip for reliable isolation/ separation of nanoparticles and developed a passivation technique for the protection of the DEP chip electrodes. The electrode passivation process was designed using a hydrogel and the stability of the hydrogel passivation layer was verified. The fabricated DEP chip and the proposed passivation technique were used for the collection and dispersion of the fluorescent polystyrene nanoparticles. The proposed chip and the technique for isolation and separation of nanoparticles can be leveraged in various bioelectronic applications.

An Efficient Shaking Correction Techniques for Image Stabilization of Moving Vehicles (이동차량 영상 안정화를 위한 효율적인 흔들림 보정 기법)

  • Hong, Sung-Il;Lin, Chi-Ho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.14 no.3
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    • pp.155-162
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    • 2014
  • In this paper, we propose an efficient shaking correction techniques for a moving vehicle image stabilization. The proposed shaking correction techniques was calculated cumulative histogram for the conversion and the separating information via color separation of video image frame of the input received. And it were to matching the histogram for match the color information as compensation result of the shaking vehicle video imaging. In this paper, the proposed the shaking correction techniques was obtained to the restoration result when compared to the existing shaking correction techniques that the smallest noise and better the naturalness of image through stabilization of luminance level and color level. Also, the imaging stabilization method was demonstrated the efficiency compared to other methods through to the real-time processing without the use of the memory.

The Development of Electrostatic Separation Technique for Recycling of Life Circles Waste Plastic (생활계 폐플라스틱 재활용을 위한 정전선별 기술개발)

  • Jeon Ho-Seok;Park Chul-Hyun;Kim Byoung-Gon;Park Jai-Koo
    • Resources Recycling
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    • v.15 no.1 s.69
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    • pp.28-36
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    • 2006
  • The development of material separation technique for waste plastic recycling are the necessary situation restricted by law the reclamation and incineration of waste plastic after 2004, with enforcement of EPR (Extended Producer Responsibility) system. As the this study is the research on the development of electrostatic separation techniques for recycling of life circles waste plastic by development of charging material and charger, the separation efficiency can be improved. Therefore, we developed the charger and electrostatic separator to increase charging efficiency and material separation per object plastics, rising these equipments, we removed PVC up to $99\%$ from two kinds of mixed plastics. And in case of restricting PVC content such as PET, we developed the separation technique that can remove PVC up to $99.99\%$ from PET with PET recovery about $80\%$. Also, as we separated over $98\%$ for three kinds of mixed plastics, and then established material separation technique to increase recycling of plastic.

The Development of Electrostatic Separation Technique for Recycling of Life Circles Waste Plastic (생활계 폐플라스틱 재활용을 위한 정전선별 기술개발)

  • Jeon, Ho-Seok;Park, Chul-Hyun;Kim, Byoung-Gon;Park, Jai-Koo
    • Proceedings of the Korean Institute of Resources Recycling Conference
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    • 2005.10a
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    • pp.23-33
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    • 2005
  • The development of material separation technique for waste plastic recycling are the necessary situation according to restrict by law the reclamation and incineration of waste plastic after 2004 year, pith enforcement of EPR (Extended Producer Responsibility) system. As the this study is the research on the development of electrostatic separation techniques for recycling of life circles waste plastic, it can improve separation efficiency according to development of charging material and charger. Therefore, we developed the charger and electrostatic separator to increase charging efficiency and material separation per object plastics, using these equipments, we removed PVC up to 99% from two kinds of mixed plastics. And in case of restricting PVC content such as PET, we developed the separation technique that can remove PVC up to 99.99% from PET with PET recovery about 80%. Also, as we separated over 98% for three kinds of mixed plastics, and then established material separation technique to increase recycling of plastic.

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Solution NMR spectroscopy for investigation of liquid-liquid phase separation

  • Saio, Tomohide;Okumura, Masaki;Lee, Young-Ho
    • Journal of the Korean Magnetic Resonance Society
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    • v.24 no.2
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    • pp.47-52
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    • 2020
  • Liquid-liquid phase separation (LLPS) of biomolecules, a newly-found phase behavior of molecules in the liquid phase, has shown to its relationship to various biological function and misfolding diseases. Extensive studies have increasingly revealed a general mechanism of LLPS and characterized the liquid droplet; ho wever, intermolecular interactions of proteins and structural states of LLPS-inducing proteins inside of the droplet remain largely unknown. Solution NMR spectroscopy has emerged as a powerful approach as it provides invaluable information on protein intermolecular interactions and structures at the atomic and residue level. We herein comprehensively address useful techniques of solution NMR including the effect of paramagnetic relaxation enhancement for the study on the LLPS and droplet based on recent studies.

Lightweight Intrusion Detection of Rootkit with VMI-Based Driver Separation Mechanism

  • Cui, Chaoyuan;Wu, Yun;Li, Yonggang;Sun, Bingyu
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.3
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    • pp.1722-1741
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    • 2017
  • Intrusion detection techniques based on virtual machine introspection (VMI) provide high temper-resistance in comparison with traditional in-host anti-virus tools. However, the presence of semantic gap also leads to the performance and compatibility problems. In order to map raw bits of hardware to meaningful information of virtual machine, detailed knowledge of different guest OS is required. In this work, we present VDSM, a lightweight and general approach based on driver separation mechanism: divide semantic view reconstruction into online driver of view generation and offline driver of semantics extraction. We have developed a prototype of VDSM and used it to do intrusion detection on 13 operation systems. The evaluation results show VDSM is effective and practical with a small performance overhead.

Blind Source Separation for OFDM with Filtering Colored Noise and Jamming Signal

  • Sriyananda, M.G.S.;Joutsensalo, Jyrki;Hamalainen, Timo
    • Journal of Communications and Networks
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    • v.14 no.4
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    • pp.410-417
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    • 2012
  • One of the premier mechanisms used in extracting unobserved signals from observed mixtures in signal processing is employing a blind source separation (BSS) algorithm. Orthogonal frequency division multiplexing (OFDM) techniques are playing a prominent role in the sphere of multicarrier communication. A set of remedial solutions taken to mitigate deteriorative effects caused within the air interface of OFDM transmission with aid of BSS schemes is presented. Four energy functions are used in deriving the filter coefficients. Energy criterion functions to be optimized and the performance is justified. These functions together with iterative fixed point rule for receive signal are used in determining the filter coefficients. Time correlation properties of the channel are taken advantage for BSS. It is tried to remove colored noise and jamming components from themixture at the receiver. Themethod is tested in a slow fading channel with a receiver containing equal gain combining to treat the channel state information values. The importance is that, these are quite low computational complexity mechanisms.

Nano-scale Shell in Phase Separating Gd-Ti-Al-Co Metallic Glass

  • Chang, Hye Jung;Park, Eun Soo;Kim, Do Hyang
    • Applied Microscopy
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    • v.43 no.2
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    • pp.98-101
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    • 2013
  • In the present study, formation of yard and shell has been investigated in as-melt-spun $Gd_{30}Ti_{25}Al_{25}Co_{20}$ alloy using a variety of transmission electron microscopy techniques. The phase separation during cooling leads to the formation of the microstructure consisting of amorphous droplets with different size scales embedded in the amorphous matrix. Due to the interdiffusion at the interface after the first-step phase separation, ~50 nm-thick yard develops on the surface of the primary droplet particle. Due to the critical wetting phenomenon, ~5 nm thickness shell enveloping the droplet forms. The sell is enriched in Co and Ti, implying that the composition is close to that of the droplet.