• Title/Summary/Keyword: particle suspension

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Analytical Study on the Gas-Solid Suspension Flows through Sonic and Supersonic Nozzles (음속 및 초음속 노즐을 통한 Gas-Solid Suspension 유동에 대한 해석적 연구)

  • Sun, JianGuo;Rajesh, G.;Kim, Heuydong
    • Journal of the Korean Society of Propulsion Engineers
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    • v.17 no.1
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    • pp.9-17
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    • 2013
  • A considerable deal of work has been carried out to get an insight into the gas-solid suspension flows and to specify the particle motion and its influence on the gas flow field. In this paper an attempt is made to develop an analytical model to study the effect of nozzle inlet/exit pressure ratio, particle/gas loading and the particle diameter effect on gas-solid suspension flow. The effect of the particle/gas loading on the mass flow, Mach number, thrust coefficient and static pressure variation through the nozzle is analyzed. The results obtained show that the presence of particles seems to reduce the strength of the shock wave. It is also found that smaller the particle diameter is, bigger will be the velocity as bigger particle will have larger slip velocity. The suspension flow of smaller diameter particles has almost same trend as that of single phase flow with ideal gas as working fluid. Depending on the ambient pressure, the thrust coefficient is found to be higher for larger particle/gas loading or back pressure ratio.

The Preparation of D-Phenylalanine Imprinted Microbeads by a Novel Method of Modified Suspension Polymerization

  • Khan, Hamayun;Park, Joong-Kon
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.6
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    • pp.503-509
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    • 2006
  • Molecularly imprinted polymeric microbeads (MIPMs) were prepared by the suspension and modified suspension polymerization methods using D-phenylalanine as the template, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, toluene as the porogen, polyvinyl alcohol as the stabilizer, and sodium dodecyl sulfate as the surfactant. The addition of a surfactant to the conventional suspension polymerization mixture decreased the mean particle size of the MIPMs and increased the adsorption selectivity. For the modified suspension polymerization method, the mean particle size of the MIPMs was smaller than the particle size of MIPMs prepared via conventional suspension polymerization. Moreover, the adsorption selectivity improved considerably compared to the adsorption selectivities of MIPs reported previously.

Effect of Fluid Viscosity on the Suspension of a Single Particle in Channel Flow (채널 유동에서 점성이 단일 입자 혼합 유동의 suspension에 미치는 영향)

  • Choi, Hyoung-Gwon
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.33 no.3
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    • pp.194-200
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    • 2009
  • Suspension of a single solid particle in a channel flow with a constant pressure gradient is studied numerically. The interaction of a circular particle with a surrounding Newtonian fluid is formulated using a combined formulation. Numerical results are presented using two dimensionless variables: the sedimentation Reynolds number and the generalized Froude number. From the present results, it has been shown that a solid particle is suspended at a smaller generalized Froude number as the viscosity of the surrounding fluid increases. The time taken for equilibrium position is found to be smaller as fluid viscosity increases when both : the sedimentation Reynolds number and the generalized Froude number are the same while, at the same situation, the dimensionless time taken for equilibrium position is to be nearly the same regardless of fluid viscosity when a dimensionless time variable is introduced

Use of 1,064-nm Q-switched Neodymium:Yttrium-aluminum-garnet Laser Therapy Assisted with Diamond Particle Suspension and Gold Microparticle Application for Acne Vulgaris and Enlarged Facial Pores

  • Park, Hee Ung;Cho, Hangrae;Lee, Sang Ju;Cho, Han Kyoung
    • Medical Lasers
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    • v.10 no.4
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    • pp.242-245
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    • 2021
  • Acne vulgaris is a common inflammatory skin disease of the pilose-baceous unit. It appears as lesions consisting of comedones, papules, pustules, and nodules of varying shapes and severity. In general, the first-line treatment for acne vulgaris includes topical and oral medication. Recently, various physical modalities have also been investigated. The use of laser therapy is steadily increasing because of its fewer side effects, short procedure time, and rapid results. In particular, laser therapy assisted with carbon suspension application is effective for acne vulgaris but may sometimes result in discomfort due to odor and dust formation during the procedure. Herein, we report that acne vulgaris and enlarged facial pores can be safely and effectively treated with laser therapy assisted with diamond particle suspension and gold microparticle application, which can address the discomfort caused by the carbon suspension application.

Rheological Characteristics of Magnetic $\gamma$-$Fe_{2}O_{3}$ and $CrO_2$ Particle Suspension (자성 $\gamma$-$Fe_{2}O_{3}$$CrO_2$ 입자 분산액의 유변특성 연구)

  • 김철암;이준석;최형진
    • The Korean Journal of Rheology
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    • v.11 no.2
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    • pp.128-134
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    • 1999
  • Rheological characterization was examined for two different types of magenetic particle (rod-like $\gamma$-$Fe_{2}O_{3}$, $CrO_2$ )suspension in this study. The measured suspension viscosity (viscosity vs. concentration or shear rate) is used to obtain the dependence of viscous energy dissipation on the microstructural states of magnetic particle dispersions as well as the microstructural shape effects which are related to magnetic particle orientation. The empirical formulas from mean field theory and the Mooney equation are used to relate suspension viscosity to particle concentration. Intrinsic viscosities of these two different types of rod-like magnetic particle suspensions are found to exceed the prediction of hydrodynamic theory for dilute suspensions and support the existence of flocs containing significant amounts of immobilized suspending medium due to native attraction forces among particles in the microstructures.

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Rheological Modeling of Nanoparticles in a Suspension with Shear Flow (전단 흐름을 갖는 서스펜션 내부 나노 입자의 유변학적 특성 연구)

  • Kim, Gu;Fukai, Jun;Hironaka, Shuji
    • Applied Chemistry for Engineering
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    • v.30 no.4
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    • pp.445-452
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    • 2019
  • Shear thickening is an intriguing phenomenon in the fields of chemical engineering and rheology because it originates from complex situations with experimental and numerical measurements. This paper presents results from the numerical modeling of the particle-fluid dynamics of a two-dimensional mixture of colloidal particles immersed in a fluid. Our results reveal the characteristic particle behavior with an application of a shear force to the upper part of the fluid domain. By combining the lattice Boltzmann and discrete element methods with the calculation of the lubrication forces when particles approach or recede from each other, this study aims to reveal the behavior of the suspension, specifically shear thickening. The results show that the calculated suspension viscosity is in good agreement with the experimental results. Results describing the particle deviation, diffusivity, concentration, and contact numbers are also demonstrated.

A Study on Characteristic of Filter Processing Using Kozeny-Carman Model and Measuring of PCS (PCS측정 기술과 Kozeny-Carman 모델을 이용한 여과공정 특성연구)

  • Ha, Sang An;Kim, Seung Ho;Yun, Tae Gyeong
    • Journal of Environmental Science International
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    • v.13 no.9
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    • pp.799-806
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    • 2004
  • The filtration tests were made in cell with a low concentrated suspension. The suspension with a concentration of $C_{M}$=1.14~2.67$\cdot$$10^{-3}$ g/g consists of paper paint and water. The particles in the suspension have a particle size x<1${\mu}m$. The used depth filters consists of glass fibres, which are coated by polymer. The filtration in depth filters accorded in different mechanism, which were explained by physical models. The model which would be allows to make a promise of the filtration reaction. This filter media allows to get a high filtration time and a good separation rate. The Particle distribution is measured by a photon correlation spectroscopy(PCS). PCS measures particle sizes 0.03 ${\mu}m$${\mu}m$ in the suspension. The filtered suspension has a very low concentration Co{\le}5{\times}10_{-4}$ g/g of solid in sample. The PCS also informs us about the number of the particles in the suspension. The makes it possible to calculate the concentration of the in sample.

Study on size distribution and characteristics of particulate matter suspension in indoor space depending on relative humidity (상대습도에 따른 비산 미세먼지의 크기 분포 및 특성 분석)

  • Minjeong Kim;Jiwon Park
    • Particle and aerosol research
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    • v.20 no.2
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    • pp.25-33
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    • 2024
  • Suspension of particulate matter (PM) in indoor spaces, which increases risk of negative impact on occupants' health from exposure to PM, is influenced by humidity level in the indoor environment. The goal of this study is to investigate the property of size-resolved PM suspension in accordance with the relative humidity through simulation chamber experiments which reflect the indoor environmental characteristics. The relative humidity of simulation chamber is adjusted to 35%, 55% and 75% by placing it inside a real-size environmental chamber which allows artificial control of climatic conditions (e.g., temperature, humidity). At the respective humidity conditions, PM suspension concentration caused by occupant walking is analyzed by particle size (0.5-0.8, 0.8-1.0, 1.0-2.5, 2.5-3.5, 3.5-4.5, 4.5-5.5, 5.5-8.0, and 8.0-10 ㎛). Irrespective of the particle size, the suspension concentration reveals a decreasing tendency as the relative humidity increases. Furthermore, a one-way analysis of variance (one-way ANOVA) test statistically verifies that the suspension concentration has a significant difference depending on the indoor relative humidity level. In addition, as the relative humidity increases, a proportion of the suspended particles with 0.5-2.5 ㎛ diameter decreases, while that with 2.5-3.5 ㎛ diameter increases. The reason is considered that the humidity has an effect on adhesion and coagulation forces of the particles.

The role of polymers in dispersion stability and film formation of silica/PVA suspension

  • Kim, Seon-Hyeong;Seong, Jun-Hui;An, Gyeong-Hyeon;Lee, Seung-Jong
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2010.05a
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    • pp.23.2-23.2
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    • 2010
  • Researches on the drying of particle/polymer suspensions receive attentions in technical applications such as manufacturing display and batteries. In this study, the effect of polymers on drying behavior of silica/poly(vinyl alcohol) suspension was investigated in terms of suspension stability and stress development during drying. The effect of polymer adsorption was studied by changing pH. More strongly flocculated suspension with lower pH became more dispersed and close-packed film after drying. Evaluation of potential energy allows us to suggest that the adsorbed polymers which bridge the particles introduce steric repulsion and lead flocculated suspension to dispersed film. When the effect of adsorption kinetics was studied by changing the mixing time, the adsorption amount, characteristic stress and dried film density showed a similar behavior in the form of with a single characteristic time. It implies that the drying process can be determined by simple characteristic equation with a single time constant.

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Study on Mechanism of Mechanical Damping System Based on The Colloidal Suspension of Nano-Porous Particles (나노 다공성 입자의 콜로이드 서스펜션을 이용한 기계적 감쇠기구에 대한 연구)

  • W.J, Song;Kim, J.;B.Y. Moon;B.S. Kang
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2003.10a
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    • pp.359-362
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    • 2003
  • Damping systems have been widely used to various industrial structures and are mainly hydraulic and pneumatic devices nowadays. In this work, a novel damping system based on the colloidal suspension in the field of nanotechnology is investigated. The colloidal suspension consists of Iyophobic working fluid and hydrophobic-coated porous particle. The mechanism of mechanical energy dissipation in damping system based on the colloidal suspension with nano-porous particles is different from that of the existing hydraulic damping system. The absorbed energy of the damping system using colloidal suspension can be calculated through the mechanical equilibrium condition by the superficial tensions of liquid-gas Interface in the hydrophobic surface in nano-porous particles. The results from an analytic approach have a reasonable agreement with experimental results.

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