• Title/Summary/Keyword: the viscosity

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A Study on Selecting Conditions of Rapid Prototype for Controls of Shape of Micro-hole (미세홀 형상제어를 위한 쾌속조형의 조건선정에 관한 연구)

  • Kim T.H.;Park J.D.;Lee S.S.;Seo S.H.;Jeon E.C.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2005.06a
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    • pp.738-742
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    • 2005
  • Rapid Prototype has been used to design and Production of part in a variety of fields ; Car, Electronic products, Aviation, Heavy industry etc. Moreover development of hardware gave rise to use the method of Rapid Prototype more and more at high precision and complicated shapes. Expecially, to be using process of products that shapes of Micro-hole ; Cellular phones, Antennas, Jewels, Semi conductor cases. In case of Micro-shape, precision of the shape turns on various condition ; Laser size, Laminate height, scanning speed, overcure, viscosity of resin, etc. Sometimes breaks out the case that interner hole of shape is blocked by viscosity of resin. The phenomenon has solved easily to reduce viscosity of resin. But, in case of the method brings about the problem that strength goes down in actuality products hardening. This study on verify to change of shape of Micro-hole and makes the semiconductor case which has shape of Micro-hole by using resin of higher viscosity, scanning speed and overcure

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A Study on the Properties of Ethylene-Vinyl Acetate Emulsion Blended with SBR, Urethane and Epoxy Latex (에폭시, 우레탄 및 SBR계 라텍스를 혼합한 에틸렌-비닐아세테이트 에멀젼의 특성에 관한 연구)

  • Choi, Sang-Goo
    • Elastomers and Composites
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    • v.34 no.5
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    • pp.414-422
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    • 1999
  • SBR, polyurethane and epoxy latex were separately blended with ethylene-vinyl acetate(EVA) emulsion In $0{\sim}50%$. EVA emulsion was not reacted with latexes in liquid phase and mixtures had good stroage stability. The viscosity of cement mixtures was elevated to 20,000cps in $0.5{\sim}2.0$ hours by mixing. The mixtures mixed with pigment represented high viscosity and showed higher viscosity as time goes by. Mixtures had higher hardness with mixing SBR than mixing epoxy or urethane. The hardness was suddenly increased over cement content 30%. showed pencil hardness $H{\sim}2H$ in $50{\sim}60%$. The increase of hardness in high solids was depended upon not only the condensation of latexs but also the coagulation and adhesion of cement particle.

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Studies on Rheological Properties of High Solid Coating Colors(Part 2) - Effect of Rheology Modifiers on High-Shear Viscosity and Dynamic Penetration Behavior - (고농도 도공액의 유동특성에 관한 연구(제2보) - 유동성 조절제가 고전단 점도 및 동적 침투특성에 미치는 영향 -)

  • Yoo, Sung-Jong;Cho, Byoung-Uk;Lee, Yong-Kyu
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.43 no.3
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    • pp.121-127
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    • 2011
  • This study used two types of rheology modifiers including an alkali-swellable emulsion (ASE) and an surface-adhesion emulsion (SAE) to elucidate their effects on high shear viscosity and dynamic penetration behavior among the flow properties of high solids coating. Since rheology under high shear and dynamic penetration behavior significantly affect the quality of coated paper in case of high solids coating, it is very important to examine the variations in rheology of high solids coating color by rheology modifier. It was found that the high solids coating color prepared with the SAE type showed superior dynamic penetration behavior and high shear viscosity than that with the ASE type rheology modifier.

An assessment of friction factor and viscosity models for predicting the refrigerant characteristics in adiabatic capillary tubes (마찰 계수와 점성 계수 모델이 단열 모세관 유동에 미치는 영향 평가)

  • Son, Ki-Dong;Park, Sang-Goo;Jeong, Ji-Hwan;Kim, Lyun-Su
    • Proceedings of the SAREK Conference
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    • 2008.11a
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    • pp.47-54
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    • 2008
  • Capillary tubes are widely used as expansion device in small refrigeration systems. The refrigerant flowing in the capillary tube experiences frictional and accelerational head losses, and flashing, simultaneously. In this paper flow characteristics of adiabatic capillary tubes with various friction factor models, two-phase viscosity models, and two-phase frictional multiplier models were simulated. The predicted pressure distribution, mass flow rate are compared with experimental data reported in literature. It is confirmed that the predicting accuracy with homogeneous model can be improved by employing the suitable correlations of friction factor and two-phase viscosity model, and two-phase frictional multiplier.

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Quality Characteristics of Dried Noodles Added with Ligularia fischeri Powder (곰취 분말을 첨가한 국수의 품질특성)

  • Park, Bock Hee;Joo, Ha Mi;Cho, Hee Sook
    • Journal of the Korean Society of Food Culture
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    • v.29 no.2
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    • pp.205-211
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    • 2014
  • This study investigated the quality of noodles containing different amounts of Ligularia fischeri powder (LFP). Noodles were prepared at ratios of 0, 1, 3, 5, and 7% LFP based on flour weight. Cooking quality, mechanical texture properties, and viscosity were measured, and a sensory evaluation was performed with the prepared noodles. Gelatinization points of the composite LFP-wheat flours increased. As measured via amylography, viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of samples decreased, as the LFP content increased. As increasing amounts of LFP were added, the L, a, and b values decreased while color values, weight, and volume of cooked noodles increased, as did the turbidity of the soup. With regard to textural characteristics, LFP additive increased hardness, cohesiveness, and springiness, while decreasing adhesiveness. Sensory evaluation showed that high quality cooked noodles could be produced by inclusion of 3% LFP.

Spray Characteristics according to Fluid Properties and Electric Parameters of Electrospray (정전분무의 유체 물성치와 정전 매개변수 따른 분무특성)

  • Kim, JiYeop;Hong, Jung Goo
    • Journal of ILASS-Korea
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    • v.25 no.2
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    • pp.81-88
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    • 2020
  • Electrospray is used in various industries because it can produce continuous and uniform droplets. However, it is difficult to find optimal spraying condition due to lack of data in various conditions. In this study, various conditions were divided into electric parameters and fluid property. The electric parameters set Nozzle to Substrate(NTS), nozzle diameters and the fluid property set viscosity and conductivity as conditions. In this study, it observes spray patterns, Sauter Mean Diameter(SMD) according to conditions. As a result, fluid properties had a greater effect on the cone-Jet mode than on the nozzle diameter, NTS, and flowrate. All of solutions have Stable cone-jet mode at voltage of 8.5 kV, NTS of 20 mm and nozzle diameter of 0.2 mm. SMD has 27% different depending on viscosity and conductivity. The increased flowrate and viscosity are rising break-up length and thickening jet also jet is thinned by increased conductivity. Experiments have confirmed that the jet is thickened by increased flowrate and viscosity, and that the jet is thinned by conductivity.

Changes in pasting properties and free fatty acids of different brown rice cultivar during storage

  • Choi, Induck;Kwak, Jieun;Yoon, Mi-Ra;Chun, Areum;Choi, Dong-Soo
    • Food Science and Preservation
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    • v.24 no.4
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    • pp.491-496
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    • 2017
  • Paddy rice is typically stored during postharvest until rice grain is processed into brown rice and milled rice by hulling and milling procedure, respectively. Recently, instead of storing paddy rice, storage of brown rice has been in the spotlight because it is more convenient and economically feasible. Different brown rice cultivars with varying amylose contents including waxy rice, medium-waxy rice, and non-glutinous rice were stored in room temperature storage for four months, and the changes in grain qualities of brown rice were evaluated. Amylose content significantly affected pasting properties in which rice cultivar with higher amylose content showed longer pasting time and higher peak viscosity. Storage also affected pasting viscosities, showing an increase in peak viscosity, but a decrease in breakdown viscosity. The changes in pasting viscosity during storage could be an important starch property for aged brown rice utilization. Waxy brown rice showed the weakest aging property in terms of free fatty acids (FFA) accumulation, whereas non-glutinous rice was more substantial grain quality against aging. The FFA values of two months storage were not significantly different from the initial FFA contents, suggesting that brown rice stored in room temperature for two months could be feasible for direct consumption of brown rice.

Quality Characteristics of Dried Noodle containing Capsosiphon fulvescens Powder (매생이 분말을 첨가한 국수의 품질 특성 연구)

  • Park, Bock-Hee;You, Mi-Jin;Cho, Hee-Sook
    • Journal of the East Asian Society of Dietary Life
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    • v.25 no.2
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    • pp.300-308
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    • 2015
  • This study investigated the quality of noodles containing different amounts of Capsosiphon fulvescens powder. Noodles were prepared with C. fulvescens powder at ratios of 0, 1, 2, 3 and 4% based on flour weight. Cooking quality, mechanical texture properties, and viscosity were measured, and a sensory evaluation was performed with the prepared noodles. Gelatinization points of the composite C. fulvescens powder-wheat flours increased. As measured via amylography, viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of samples decreased as C. fulvescens powder content increased. As increasing amounts of C. fulvescens powder were added, L, a and b values decreased, whereas color values, weight, and volume of cooked noodles increased, as did turbidity of the soup. In the texture meter test, hardness, cohesiveness, and springiness increased according to increasing concentrations of C. fulvescens powder. However, adhesiveness of noodles decreased by addition of C. fulvescens powder. Sensory evaluation showed that high quality cooked noodles could be produced by 3% inclusion of C. fulvescens powder.

A Study on Field Applicability Evaluation of the Hydrophobic - Low Viscosity Surface Treatment Material for Pavement Preventive Maintenance (소수성 특성을 이용한 저점도 AP 표면처리재의 현장 적용성 연구)

  • Choi, Jun Seong
    • International Journal of Highway Engineering
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    • v.16 no.1
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    • pp.31-39
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    • 2014
  • PURPOSES : Surface treatment material for pavement preventive maintenance should be inspected field applicability. This study(Part II) aimed to checkup coating characteristics and performance analysis using lab and field tests. The hydrophobic - low viscosity filling material for pavement preventive maintenance is presented in Part I, which is a series of companion study. METHODS : Relative comparison between general asphalt mixtures and surface treatment asphalt mixtures are analyzed and measured for the field application such as indirect tensile strength ratio(TSR), abrasion resistance, crack propagation resistance, temperature resistance, coating thickness, permeability resistance and skid resistance in terms of british pendulum number(BPN). RESULTS : It is found that TSR, crack propagation resistance and permeability resistance is increased as against uncoated asphalt specimen. Abrasion resistance and temperature resistance is secured from the initial coating thickness point of view, which is about 0.2~0.3mm. Skid resistance on the surface treatment pavement is satisfied with the BPN criteria of national highway because of exposed aggregate and crack sill induced pavement deterioration and damage cracks. CONCLUSIONS : The hydrophobic - low viscosity surface treatment material for pavement preventive maintenance is validated on field applicability evaluation based on quantitative analysis of coating thickness and performance analysis using lab and field tests.

Quality Characteristics of Black Sesame Gruel with High-Dietary Fiber Rice 'Goami 2' (고아미 2호를 기반으로 한 흑임자죽의 품질 특성)

  • Lee, Eun-Ju;Seo, Han-Seok;Lee, Seung-Yeon;Kim, Soo-Hee;Hwang, In-Kyeong
    • Korean journal of food and cookery science
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    • v.22 no.6 s.96
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    • pp.940-948
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    • 2006
  • The objective of this study was to develop black sesame gruel with high-dietary fiber rice, 'Goami 2'. Physical and sensory properties of black sesame gruel with various ratios of black sesame by weight (20, 40, 60%) and various water volumes(1100, 1200, 1300 mL) were investigated using colorimeter, consistometer, viscometer, sensory evaluation panel and consumer evaluation. The black sesame content significantly(p<0.001) affected the mechanical characteristics(color, consistency and viscosity), sensory characteristics(blackness, glossy, nutty, astringent taste, bitter taste and viscosity) and sensory acceptance(color acceptance, taste acceptance, viscosity acceptance and overall acceptance). The water content significantly(p<0.05) affected the mechanical characteristics(consistency and viscosity), sensory characteristics(viscosity) and sensory acceptance(taste acceptance, viscosity acceptance and overall acceptance). In the black sesame gruel, as black sesame weight ratio increased, the brightness, redness, yellowness and viscosity were decreased while the consistency, blackness, glossy, nutty, astringent taste and bitter taste were increased. In the sensory evaluation results, the optimal material mixing ratio for gruels was black sesame : Goami 2 = 40(80 g) : 60(120 g), water 1200 mL.