• Journal of Energy Engineering
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• v.13 no.4
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• pp.235-241
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• 2004

This experiment was undertaken to investigate the atomization characteristics of the high viscosity biodiesel blended fuel and ultrasonic energy irradiation one. Test fuels were conventional diesel fuel and biodiesel one. We compared to the characteristics of viscosity and surface tension, SMD between high viscosity biodiesel blended fuel and ultrasonic energy irradiation one. Sauter mean diameter was measured under the variation of the spray distance. Viscosity and surface tension were measured under the variation of the time trace. To measure the droplet size, we used the Malvern system 2600c. Droplet size distribution was analyzed from the result data of Malvern system. Through this experiment, we found that the condition of the ultrasonic energy irradiation situation had smaller Sauter mean diameter of droplet, viscosity and surface tension than those of the conventional situation.

• Korean journal of food and cookery science
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• v.19 no.6
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• pp.723-728
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• 2003

The sensory characteristics of cream soup containing 0, 25, 50, 75 and 100％ rice flour were investigated in order to develop a new processed food using rice. The Hunter L(lightness) value increased with the amount of rice flour, while the a(redness) value and b(yellowness) value decreased, significantly. The viscosity of rice cream soup significantly decreased with the increasing amount of rice flour. Based on the sensory evaluation, the cream soup samples with larger rice flour component showed a higher clean taste score, while those with the least rice flour resulted in higher darkness, viscosity, greasy taste, md softness. The overall acceptance was the highest in the cream soup with 75％ and 100％ rice flour. In terms of the color and viscosity, good correlations were observed between the sensory evaluation and the objective analysis. The overall acceptance showed a significant positive correlation with a clean taste, while there was a negative correlation with a greasy taste and the viscosity measured by a viscometer.

• The Korean Journal of Food And Nutrition
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• v.7 no.4
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• pp.353-360
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• 1994

Effect of pH, calcium, sucrose, heating and mixing ratio of soy and cow milk was studied on the viscosity and the sensory characteristics of cow-soy milk. The viscosity of soymilk was significantly affected by pH with showing maximum at 6.0 and the pH effect was decreased as the ratio of cow talk increased. A addition of sucrose or calcium affected little on the viscosity and a negative linear relationship was found be tween viscosity and an increase in cow milk ratio. Sensory characteristics of grassy and beany odor and taste of soymilk were rapidly decreased and nutty flavor and total acceptability were increased during initial 30 min of boiling. A further increase in boiling affected little on tastes and odors of soymilk. The beany odor and taste linearly decreased and milk flavor Increased as the ratio of cow milk increased. The total acceptability of 50 : 50 was found to be maximum for cow and soy mixed milks.

• Journal of the Korean Society of Food Culture
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• v.24 no.4
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• pp.419-425
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• 2009

This study examined the effects of added amounts of shrimp powder on the physical and sensory properties of Jook for elderly foodservice operation. According to the amylograph data, the composite shrimp flour-wheat flour samples increased the gelatinization temperature, with increasing shrimp-flour content; moreover, initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity were reduced. As the level of shrimp powder in samples increased, L-values decreased, and a-values and b-values increased. In addition, the Jook had higher viscosity and lower spreadability values as the amount of shrimp powder increased. Sensory characteristics, such as nutty taste, color, viscosity, and overall preference increased significantly with the addition of shrimp powder. In conclusion, to enhance the quality of Jook, a 3% addition of shrimp powder would be the most beneficial.

• Tribology and Lubricants
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• v.30 no.3
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• pp.189-198
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• 2014

This paper presents the results of an experimental investigation of the correlation between the lubrication characteristics of an engine and its fuel economy. Improving the lubrication characteristics of the engine oil is one of the most efficient ways to improve a car's fuel economy. The methods to accomplish this include lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver. In addition, it is necessary to use different methods to reduce the friction to individual lubrication areas, because different lubrication regimes are used for different engine parts. The experimental investigation in this study is based on design of experiments ; this paper presents the results of a modified Sequence VID test, which is an ASTM standard test used to measure the effects of automotive engine oils on the fuel economy of passenger cars. The results demonstrate the effects of the following lubrication factors on the fuel economy : the low temperature cranking viscosity, high-temperature high shear (HTHS) viscosity, friction modifier, polymer type and shear stability index of the viscosity index improver. Moreover, this study involves an analysis of variance based on design of experiments. The test results show that the HTHS viscosity, friction modifier and shear stability index of the viscosity index improver are more effective than the other factors. Therefore, lowering the viscosity, adding a friction modifier and optimizing the shear stability index of a viscosity index improver should be considered to improve fuel economy.

• Tribology and Lubricants
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• v.25 no.4
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• pp.236-242
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• 2009

Oil viscosity is one of the important parameters for machinery condition monitoring. Basically, it is expressed as kinematic viscosity measured by capillary flow and dynamic or absolute viscosity measured by rotary shear viscometry. Recently, acoustic wave techniques appear in the market, measuring viscosity as the product of dynamic viscosity and density. For Newtonian fluids, knowledge of density allows conversion from one viscosity parameter to the other at a specific shear rate and temperature. In this work, oil samples with different chain lengths of viscosity index (VI) improvers and concentrations were examined by different viscometric techniques. Results showed that acoustic viscosity measurements give misleading results for oil samples with high molecular weight VI improvers and at low temperatures ${\leq}40^{\circ}C$.

• Tribology and Lubricants
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• v.15 no.4
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• pp.343-353
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• 1999

The role of viscosity index improver's(Ⅶ) additives for modem engine lubrication is complex. Under the condition of atmosphere or low shear rate, the characteristics of Ⅶ added lubricant is verified and quoted frequently for mathematical model of lubricant behavior. However, recent research shows that added lubricant has the characteristics of shear thinning at high shear rate condition although it performs well enough over the whole range of working temperature. At high shear rate, they show significant decrease of apparent viscosity irrespective of temperature. Many experimental researches verify that Ⅶ added lubricant shows boundary film layer formation on the solid surface as well as shear thinning effect by its polymeric molecular characteristics. The intend of our research is to verify the effects of Ⅶ from the viewpoint of continuum mechanics, because conventional Reynolds'equation with only pressure-viscosity relation cannot fully predict the lubricant behavior under the Ⅶ added condition. In these aspects, Reynolds'equation of Newtonian fluid model lacks the reflection of real fluid behavior and there is no way to explain the non-linear characteristics of Ⅶ added lubricant. In this research, we mathematically modeled the Ⅶ added lubricant behaviors which are the characteristics of non-Newtonian fluid behavior at high shear rate and boundary film formation on the solid surface. The consideration of elastic deformation in the contact region is also included in our computation and finally the converged film pressure and the film thickness with elastic deformation are obtained. The results are compared with those of Newtonian fluid model.

• Tribology and Lubricants
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• v.36 no.6
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• pp.365-370
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• 2020

Recently, additive manufacturing (AM) technology has been applied to various industries such as automotive, aviation, medical, and electronics. Most prior studies are limited to the mechanical properties of printed materials, and few studies are being conducted on their tribological characteristics. However, the friction and wear characteristics of the material should be studied in order to utilize the components manufactured using AM technology as mechanical parts. In this study, the friction and wear characteristics of acrylonitrile-butadiene-styrene (ABS)-like resin printed with stereo lithography apparatus (SLA) 3D printing are evaluated according to the viscosity of silicon oil lubricant using a ball-on-disk experiment. Lubricants with a viscosity of 500, 1000, and 2000 cSt are prepared for the experiment. If silicon oil lubricants are used during the ball-on-disk test, the coefficient of friction (COF) and wear rates are significantly reduced, and the higher the viscosity of the lubricant, the lower will be the COF and wear rates. It is also verified that the temperature of the specimen owing to friction also decreases according to the viscosity of the lubricant. This is because of the silicon oil film thickness, and the higher the viscosity of the lubricant, the thicker will be the oil film. More studies on the tribological characteristics of 3D printing materials and suitable lubricants will be required to use 3D printed parts as mechanical elements.

• Nuclear Engineering and Technology
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• v.55 no.2
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• pp.566-574
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• 2023

Investigating the seepage characteristics of the leaching solution in the ore-bearing layer during the in situ leaching process can be useful for designing the process parameters for the uranium mining well. We prepared leaching solutions of four different viscosities and conducted experiments using a self-developed multifunctional uranium ore seepage test device. The effects of different viscosities of leaching solutions on the seepage characteristics of uranium-bearing sandstones were examined using seepage mechanics, physicochemical seepage theory, and dissolution erosion mechanism. Results indicated that while the seepage characteristics of various viscosities of leaching solutions were the same in rock samples with similar internal pore architectures, there were regular differences between the saturated and the unsaturated stages. In addition, the time required for the specimen to reach saturation varied with the viscosity of the leaching solution. The higher the viscosity of the solution, the slower the seepage flow from the unsaturated stage to the saturated stage. Furthermore, during the saturation stage, the seepage pressure of a leaching solution with a high viscosity was greater than that of a leaching solution with a low viscosity. However, the permeability coefficient of the high viscosity leaching solution was less than that of a low viscosity leaching solution.

• Korean journal of food and cookery science
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• v.24 no.6
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• pp.882-890
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• 2008

The present study investigated the influence of different volumes of red hot pepper juice on the quality characteristics of fresh Pasta noodle. Supplementation with 0% (control), 2.5%, 5%, 7.5%, or 10% red hot pepper juice produced similar gelatinization characteristics of peak viscosity, temperature at peak viscosity, hot paste viscosity and numerical value of breakdown. However, increasing concentrations of red hot pepper juice produced progressively and significantly low cold paste viscosity and setback. The chromaticity of wet and cooked noodles was significantly lower in L value and significantly higher in +a and +b values with increasing volumes of red hot pepper juice. The texture of fresh noodles displayed no significant differences in hardness, adhesiveness and chewiness. The springiness and cohesiveness were lower and higher with the increase of added red hot pepper juice, respectively, but the differences just attained significance. For cooked noodles, adhesiveness, springiness, cohesiveness and chewiness tended to be higher with increasing volumes of red hot pepper juice, but again the differences just attained significance. Cooking characteristics of weight, volume, moisture absorptive power and turbidity decreased with increasing volumes of red hot pepper juice. Sensory characteristics of acceptability including appearance, color, flavor, taste, texture and overall-acceptability improved with increasing red hot pepper juice volume, in particular with 5% and 7.5%. Amylograph characteristics for initial paste temperature positively correlated with the texture characteristics for chewiness (p<0.05). Negatively correlated amylograph parameters included texture for springiness with for peak viscosity (p<0.01), texture for adhesiveness with hot paste viscosity (p<0.01) and breakdown with texture for adhesiveness, cohesiveness and chewiness (p<0.05).