• Title, Summary, Keyword: Particle interaction

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Interfacial Electrical Effect of Particle Radius on Detergency of Particulate Soil -Particle Sizes and Dispersion Stability of Particle- (고형오구 입자크기가 고형오구의 세척성에 미치는 계면 전기적 효과 -고형오구의 입자크기와 입자의 분산안정성-)

  • Mun, Mi-Hwa;Kang, In-Sook
    • Textile Science and Engineering
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    • v.46 no.6
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    • pp.334-341
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    • 2009
  • This study was a preliminary examination to investigate the effect of particle sizes on detergency of particulate soil. Monodispersed spherical $\alpha-Fe_2O_3$ particles were prepared by hydrothermal aging of an acidic $FeCl_3$ and HCl solution. The $\zeta$-potential of $\alpha-Fe_2O_3$ particles was measured by microelectrophoresis method, and the potential energy of interaction between particles was calculated by using the heterocoagulation theory. The particle size was reduced with decreasing concentration of $FeCl_3$ and with increasing concentration of HCl. The $\zeta$-potential of $\alpha-Fe_2O_3$ particles and energy of interaction between particles were increased with decreasing particle size and increasing concentration of surfactant. But the dispersion stability of particle increased with decreasing particle size and concentration of surfactant. The dispersion stability of particle was not related to interfacial electrical condition in high concentration of surfactant solution. Such phenomenon entails some sort of interaction between interfacial electrical effect and steric stability by adsorption of surfactant.

Current Trend of Second Phase Particle-grain Boundary Interaction Research using Computer Simulations (컴퓨터 시뮬레이션 기법을 이용한 입계면 - 이상 입자 간 상호작용 모사 연구 동향)

  • Chang, Kunok
    • Journal of Korean Powder Metallurgy Institute
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    • v.27 no.4
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    • pp.339-342
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    • 2020
  • Since the interaction between the second-phase particle and grain boundary was theoretically explained by Zener and Smith in the late 1940s, the interaction of the second-phase particle and grain boundary on the microstructure is commonly referred to as Zener pinning. It is known as one of the main mechanisms that can retard grain growth during heat treatment of metallic and ceramic polycrystalline systems. Computer simulation techniques have been applied to the study of microstructure changes since the 1980s, and accordingly, the second-phase particle-grain boundary interaction has been simulated by various simulation techniques, and further diverse developments have been made for more realistic and accurate simulations. In this study, we explore the existing development patterns and discuss future possible development directions.

Effect of Disk Rotational Speed on Contamination Nano Particles Generated in a Hard Disk Drive (하드 디스크 드라이브 회전수 변화가 드라이브 내 나노 오염 입자 발생에 미치는 영향)

  • Lee, Dae-Young;Hwang, Jung-Ho;Bae, Gwi-Nam
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.8
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    • pp.976-983
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    • 2004
  • In high-density hard disk drives, the slider should be made to fly close to the magnetic recording disk to generate better signal resolution and at an increasingly high velocity to achieve better data rate. The slider disk interaction in CSS (contact-start-stop) mode is an important source of particle generation. Contamination particles in the hard disk drive can cause serious problems including slider crash and thermal asperities. We investigated the number and the sizes of particles generated in the hard disk drive, operating at increasing disk rotational speeds, in the CSS mode. CNC (condensation nucleus counter) and PSS (particle size selector) were used for this investigation. In addition, we examined the particle components by using SEM (scanning electron microscopes), AES (auger electron spectroscopy), and TOF-SIMS (time of flight-secondary ions mass spectrometry). The increasing disk rotational speed directly affected the particle generation by slider disk interaction. The number of particles that were generated increased with the disk rotational speed. The particle generation rate increased rapidly at motor speeds above 8000 rpm. This increase may be due to the increased slider disk interaction. Particle sizes ranged from 14 to 200 nm. The particles generated by slider disk interaction came from the lubricant on the disk, coating layer of the disk, and also slider surface.

Face tracking algorithm for human-computer interactive games using color-based particle filter (인터랙티브 게임을 위한 색상정보 파티클필터 기반 얼굴추적 알고리즘)

  • Truong, Mai Thanh Nhat;Kim, Sang Hoon
    • Journal of the Korean Society for Computer Game
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    • v.30 no.1
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    • pp.57-62
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    • 2017
  • For several years, keyboard and mouse have been used as the main interacting devices between users and computer games, but they are becoming outdated. Gesture-based human-computer interaction systems are becoming more popular owing to the emergence of virtual reality and augmented reality technologies. Therefore research on these systems has attracted a significant attention. The researches focus on designing the interactive interfaces between users and computers. Human-computer interaction is an important factor in computer games because it affects not only the experience of the users, but also the design of the entire game. In this research, we develop an particle filter-based face tracking method using color distributions as features, for the purpose of applying to gesture-based human-computer interaction systems for computer games. The experimental results proved the efficiency of particle filter and color features in face tracking, showing its potential in designing human-computer interactive games.

Interfacial Electrical Studies on Adhesion of Hematite Particle to Polyester Fabric and its Removal from the Fabric(Part I) -The interaction energy between particle and fabric- (Polyester직물에의 Hematite입자의 부착과 제거에 관한 계면전기적 고찰(제1보) -기질과 입자간의 상호작용에너지-)

  • Kang, In-Sook;Kim, Sung-Reon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.17 no.3
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    • pp.380-390
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    • 1993
  • Effect of interfacial electrical conditions on adhesion of ${\alpha}-Fe_2O_3$ particles to PET fabric and the removal of ${\alpha}-Fe_2O_3$ particles from PET fabric, were investigated as functions of pH, electrolyte and ionic strength. The ${\zeta}$ potential of PET fiber and ${\alpha}-Fe_2O_3$ particles in the electrolyte solution were measured by streaming potential and microelectrophoresis methods respectively. The potential energy of interaction between ${\alpha}-Fe_2O_3$ particles and PET fabric were calculated by using the heterocoagulation theory for a sphere-plate model. The negative ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber increased with pH, and then decreased certain pH and isoelectric points of ${\alpha}-Fe_2O_3$ particles and PET fiber were pH 6.5 and pH 3.5, respectively. The negative ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber affected by electrolytes, were relatively high with polyanion electrolytes in solutions and were low with neutral salts. However, at surfactant solution, ${\zeta}$ potential was levelled off. The influence of the ionic strength on the ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle was small but the negative ${\zeta}$ potential of PET fiber increased with the ionic strength. In the presence of anionic surfactant, the ${\zeta}$ potential of ${\alpha}-Fe_2O_3$ particle and PET fiber increased regardless of solution conditions. The interaction energy between ${\alpha}-Fe_2O_3$ particle and PET fabric increased with pH. The interaction energy was relatively high with polyanion electrolytes in solution, and the influence of ionic strength on the interaction energy was small, and the effective thickness of electrical double layer increased with decreasing the ionic strength.

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FREQUENCY SPECTRUM ANALYSIS OF ACOUSTIC EMISSION OF HARD DISK DRIVE HEAD/DISK INTERACTION

  • Chung, K.H.;Oh, J.K.;Moon, J.T.;Kim, D.E.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • pp.273-274
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    • 2002
  • In order to evaluate the flying characteristics of slider, the acoustic emission (AE) as well as friction signals are typically utilized. In this work the frequency spectrum analysis is performed using the AE signal obtained during the head/disk interaction such as load/unload mechanism using ramp, impact situation in the presence of a bump on disk surface and other contact phenomena including particle interaction. It was shown that the influence of impact can be characterized effectively in the AE frequency spectrum. As a result of this work, frequency spectrum analysis will be utilized with better understanding for studying the head/disk interface (HDI) characteristics and monitoring the particle interaction in HDI effectively.

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Effect of Dispersion Stability of Particles on Detergency of Particulate Soil(II) -Effect of Potential Energy of Interaction between two Particles on Dispersion Stability of Particulate Soil- (입자의 분산안정성이 고형오구의 세척성에 미치는 영향(ll) -입자와 입자간의 상호작용에너지가 고형오구의 분산안정성에 미치는 영향-)

  • 강인숙
    • Textile Science and Engineering
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    • v.39 no.1
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    • pp.93-99
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    • 2002
  • This study was designed to investigate the relationship between the interaction energy between two particles and the dispersion stability of particles as functions of pH, ionic strength, and electrolytes using $\alpha$-Fe$_2$O$_3$particle as a model of particulate soil. The ξ-potential of $\alpha$-Fe$_2$O$_3$particles in the surfactant solution was measured to calculate the potential energy of interaction between two particles using Verwey-Overbeek theory and to estimate dispersion stability of particles. Suspending power and particle size were determined by UV-Vis spectrometer and by light scattering using the polarization ratio method, respectively. The interaction energy between two particles decreased with the addition of electrolytes and increased with decreasing ionic strength. The interaction energy was minimum at neutral pH. Although some deviation exist, the general trend of the dispersion stability of particles was similar to that of potential energy of interaction between two particles regardless of solution conditions. Therefore, it appears that the dispersion stability of particles correlates well with the interaction energy of two particles.

ESTIMATION OF CAKE FORMATION ON MICROFILTRATION MEMBRANE SURFACE USING ZETA POTENTIAL

  • Alayemieka, Erewari;Lee, Seock-Heon;Oh, Jeong-Ik
    • Environmental Engineering Research
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    • v.11 no.4
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    • pp.201-207
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    • 2006
  • A simple empirical model with good quantitative prediction of inter-particle and intra-particle distance in a cake layer with respect to ionic strength was developed. The model is an inverse length scale with functions of interaction energy and hydrodynamic factor and it explains that the inter-particle and intra-particle distance in a cake is directly related to the effective size of particles. Particle compressibility with respect to ionic strength was also predicted by the model. The model corroborated very well with experimental results of polystyrene microsphere latex particles microfiltation in a dead end operation. From the results of the model, specific cake resistance could be controlled by the same variables affecting the height of particle energy barrier described by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory.

Dielectric Interaction of Particle in Electrophoresis (전기 영동에서의 입자간의 전기력에 의한 상호 작용)

  • Lee, Ho-Rim;Kang, Kwan-Hyoung
    • 유체기계공업학회:학술대회논문집
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    • pp.171-174
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    • 2006
  • When two particles close to each other are in electrophoretic motion, each particle is under the influence of the non-uniform electric field generated by the other particle. Two particles may attract or repel each other due to the dielectric force depending on their positions in the non-uniform electric field. It is shown analytically that two adjusting rigid particles can form an aggregate due to the dielectric interaction. To verify the validity of the theoretical prediction, an experiment is carried out by using a microchannel. In the experiment, AC electric field is used to eliminate cumbersome electroosmotic flow. The experimental result shows that the particles form a chain-like structure, which is typically observed in electro-rheological fluid, due to the dielectric interaction.

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