• Title/Summary/Keyword: Viscosity Effect

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Characteristics of Shear-Thinning Fluid Viscosity under Traversal Vibration (진동장에서의 전단박화 유체 점도의 특성 연구)

  • Ku Yun-Hee;Lee Ji-Hyung;Shin Sehyun
    • Proceedings of the KSME Conference
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    • 2002.08a
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    • pp.317-320
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    • 2002
  • The effect of vibration on the viscosity of a shear-thinning fluid was investigated with a newly designed pressure-scanning capillary viscometer. The viscometer was designed to measure non-Newtonian viscosity continuously over a range of shear rates at a time. Low frequency vibration was applied perpendicularly to the direction of the flow. The effect of the transversal vibration was investigated for both Newtonian fluids and non-Newtonian fluids. The experimental results showed that the vibration had no effect on the viscosity of the Newtonian fluids. However, the vibration caused a significant reduction of the shear-thinning fluid viscosity. The viscosity reduction was strongly dependent on both vibration frequency and shear rate. In addition, the viscosity reduction was affected by the amplitude of vibration, and, the bigger amplitude applied, the more viscosity reduction occurred.

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Performance Analysis of Cement Paste Including Generic and Low-viscosity Type High Range Water Reducer (저점도형 감수제 및 고성능 감수제의 사용에 따른 시멘트 페이스트 성능 분석)

  • Son, Bae-Geun;Han, Dong-Yeop
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2017.11a
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    • pp.32-33
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    • 2017
  • In order to improve the flow performance of high performance concrete, use of high performance water reducing agent and low viscosity type water reducing agent is a study of suitable range of use due to side effects. in this study, we aimed at reducing viscosity and yield value using high performance water reducing agent and low viscosity type water reducing agent, and this was evaluated using a rheometer. as a result of analysis of viscosity and yield value, it was found that the high performance water reducing agent has higher reduction effect than the low viscosity type water reducing agent. however, the larger the viscosity lowering effect is, the lower the usable range is, compared to general high performance water reducing agents, and it was found that sufficient consideration for this judgment of appropriate quantity is necessary.

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Effects of boundary layer and liquid viscosity and compressible air on sloshing characteristics

  • Zou, Chang-Fang;Wang, De-Yu;Cai, Zhong-Hua
    • International Journal of Naval Architecture and Ocean Engineering
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    • v.7 no.4
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    • pp.670-690
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    • 2015
  • In this paper, numerical investigations for tank sloshing, based on commercial CFD package FLUENT, are performed to study effects of boundary layer grid, liquid viscosity and compressible air on sloshing pressure, wave height and rising time of impact pressure. Also, sloshing experiments for liquids of different viscosity are carried out to validate the numerical results. Through comparison of numerical and experimental results, a computational model including boundary layer grid can predict the sloshing pressure more accurately. Energy dissipation due to viscous friction leads to reduction of sloshing pressure and wave elevation. Sloshing pressure is also reduced because of cushion effect of compressible air. Due to high viscosity damping effect and compressible air effect, the rising time of impact pressure becomes longer. It is also found that liquid viscosity and compressible air influence distribution of dynamic pressure along the vertical tank wall.

Effect of liquid viscosity on the degree of uniformity of drops from swirl spray nozzles (와류 분무 노즐에 의해 형성되는 액적들의 균일도에 액체의 점도가 미치는 영향)

  • 이상용;김인구;조한권
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.3
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    • pp.538-546
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    • 1989
  • Effect of liquid viscosity was studied experimentally on the drop size distributions of the liquid sprays from swirl atomizers. Glycerine-Water mixtures were used as test fluids for the experiments. Drop sizes of the liquid sprays were measured with the light scattering method. The concept of the standard deviation was introduced to represent the degree of uniformity of the drop size distributions. Experimental results show that the spray drops become coarser and less uniform with the liquid of higher viscosity. The effect of viscosity on the Sauter mean diameter and the standard deviation appeared to be more significant with the lower injection pressure. It was also confirmed that the Sauter mean diameter increases with the increase of the liquid viscosity and with the decrease of the injection pressure.

Influence of Unit Water and Viscosity Agents Contents on the Bleeding of Concrete (단위수량 및 증점제량이 콘크리트의 블리딩에 미치는 영향)

  • 김은호;심보길;황인성;전충근;한천구
    • Proceedings of the Korea Concrete Institute Conference
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    • 2001.11a
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    • pp.232-328
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    • 2001
  • This paper investigates the influences of water content and viscosity agent on the bleeding of concrete. According to test results, fluidity shows decline tendency as water content decreases, and dosage of viscosity agent increases. PEO viscosity agent does not affect the air contents while, MC viscosity agent causes air loss. As for bleeding, bleeding decreases with decrease of water content. As dosage of viscosity agent increase, bleeding decreases, regardless of viscosity kinds. It is thought that viscosity agents have the favorable effect of reducing bleeding, if fluidity and air loss are improved.

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Experimental Study on the Effect of the Amount of Acrylic Viscosity Agent on the Physical Properties of High-Fluidity Concrete using Low-Binder (아크릴계 증점제 사용량이 저분체 고유동 콘크리트의 물리적 특성에 미치는 영향에 관한 실험적 연구)

  • Ko, Hye-Bin;Kong, Tae-Woong;Cho, In-Sung;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.05a
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    • pp.72-73
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    • 2021
  • For the development of high-fluidity concrete using low-binder, The effect of the use of the developed acrylic viscosity agent on the physical properties of concrete evaluated. The amount acrylic viscosity agent used was 1.5%, 1.7%, and 2.0% based on the binder amount of 400kg/m3, and slump flow test, slump flow 500mm arrival time measurement, air volume measurement, and U-Box passing test were conducted to determine the effect of the physical properties of concrete. it was judged that 1.5% of the acrylic viscosity agent used in high-fluidity concrete using low-binder was most suitable.

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Experimental Study on the Effect of the Amount of Cellulose type Viscosity Agent on the Physical Properties of High-Fluidity Concrete Using Low-Binder (셀룰로스계 증점제의 첨가량이 고유동 저분체 콘크리트의 물리적 특성에 미치는 영향에 관한 실험적 연구)

  • Ko, Hye-Bin;Cho, In-Sung;Lee, Han-Seung
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2021.11a
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    • pp.129-130
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    • 2021
  • For the development of high-fluidity concrete using low-binder, The effect of the use of the developed acrylic viscosity agent on the physical properties of concrete evaluated. The amount acrylic viscosity agent used was 0.28%, 0.29% and 0.30% based on the binder amount of 350kg/m3, and slump flow test, air volume measurement, U-Box passing test and strength compressive were conducted to determine the effect of the physical properties of concrete. it was judged that 0.29% of the cellulose type viscosity agent used in high-fluidity concrete using low-binder was most suitable.

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The Effect of Pressure on Viscosity in Grooved Hydraulic Spool Valves (압력에 따른 점도변화가 그루브를 한 유압 스푸울 밸브에 미치는 영향)

  • Park, Tae-Jo
    • Tribology and Lubricants
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    • v.22 no.6
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    • pp.307-313
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    • 2006
  • In this paper, a theoretical analysis is carried out to study the effect of viscosity variation with pressure in multiply grooved moving hydraulic spool valves. Analytical expressions for pressure distribution in the clearance and leakage flowrate are obtained solving one-dimensional Reynolds. For constant viscosity, an analytical expression for lateral force is also presented. The results showed that variation of viscosity with pressure affect highly on pressure distribution, leakage flowrate and lateral forces in hydraulic spool valves. Therefore additional intensive studies, including numerical analysis for two-dimensional Reynolds, should be required to investigate detailed lubrication characteristics of spool valves for high pressure.

Analytical Quantification and Effect of Microstructure Development in Thick Film Resistor Processing

  • Lee, Byung Soo
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.4
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    • pp.33-37
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    • 2012
  • Microstructure developments of $RuO_2$ based thick film resistors during firing as a function of glass viscosity were analytically quantified and its effect on the electrical property was investigated. The microstructure development was retarded as the viscosity of glass was increased. It was found that the viscosity range for each stage of microstructure development are as follows ; $7500-10^5Pa{\cdot}s$ for the glass sintering, $2000-7500Pa{\cdot}s$ for the glass island formation, $700-2000Pa{\cdot}s$ for the glass spreading, and $50-700Pa{\cdot}s$ for the infiltration. The sheet resistivity decreased as the viscosity of glass in the resistor film increased due to the higher chance of sintering for the conductive particles with the higher viscosity of the glass.

Effect of Matrix Viscosity on Clay Dispersion in Preparation of Polymer/Organoclay Nanocomposites

  • Ko, Moon-Bae;Jho, Jae-Young;Jo, Won-Ho;Lee, Moo-Sung
    • Fibers and Polymers
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    • v.3 no.3
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    • pp.103-108
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    • 2002
  • The viscosity effect of matrix polymer on melt exfoliation behavior of an organoclay in poly($\varepsilon$-caprolactone) (PCL) was investigated. The viscosity of matrix polymer was controlled by changing the molecular weight of poly($\varepsilon$-eaprolactone), the processing temperature, and the rotor speed of a mini-molder. Applied shear stress facilitates the diffusion of polymer chains into the gallery of silicate layers by breaking silicate agglomerates down into smaller primary particles. When the viscosity of PCL is lower, silicate agglomerates are not perfectly broken into smaller primary particles. At higher viscosity, all of silicate agglomerates are broken down into primary particles, and finally into smaller nano-scale building blocks. It was also found that the degree of exfoliation of silicate layers is dependent upon not only the viscosity of matrix but thermodynamic variables.