• Proceedings of the Korean Fiber Society Conference
• /
• 2003.04a
• /
• pp.223-226
• /
• 2003

Due to the potential application to ultra-high strength fibers and excellent properties such as high mechanical properties, excellent thermal endurance and chemical stability, thermotropic liquid crystal polymers (TLCPS) are attractive in recent years [1, 2]. Furthermore, the melt blends of TLCPS and conventional thermoplastics have been extensively investigated because of their easy processing and high performance [3-6]. Since high performance polymers generally has high melt viscosity, introduction of the relatively low viscosity components may be one of the more effective techniques to improve processability through the decrement of melt viscosity in melt processing. (omitted)

• Journal of the Korean Society of Food Culture
• /
• v.31 no.3
• /
• pp.243-249
• /
• 2016

The purpose of this study was to investigate the effects of Capsosiphon fulvescens powder on the functional and sensory characteristics of dumpling shell. Various dumpling shell samples were prepared with wheat flour along with the addition of different amounts of Capsosiphon fulvescens powder, and then instrumental characteristics and sensory evaluations were investigated. According to amylograph data, the composite Capsosiphon fulvescens powder-wheat flour samples had increased gelatinization temperatures with increasing Capsosiphon fulvescens powder content; whereas initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15minutes, and maximum viscosity were reduced. In terms of Hunter's color values, L, a and b values decreased with increasing Capsosiphon fulvescens powder content. Besides cooked weight, cooked volume and turbidity of dumpling shell increased as the addition level of Capsosiphon fulvescens powder increase. In terms of textural characteristics, addition of Capsosiphon fulvescens powder increased springiness, chewiness, brittleness, pringiness and adhesiveness. Based on sensory evaluations, the overall preference of dumpling shell with 3% added Capsosiphon fulvescens powder, was more effective than control.

• Journal of Korea Water Resources Association
• /
• v.30 no.3
• /
• pp.201-210
• /
• 1997

To analyze the flow through open-channel constrictions using $\kappa$-$\varepsilon$ turbulence mode, a numerical model is developed. The simulated results agree well with existing experimental data which attributes to the adequate input of turbulent eddy-viscosity by turbulence model. A stream function and velocity distributions enable the analysis of flow characteristics at the downstream of constriction. Turbulent eddy viscosities over channel are spatially varied with stream pattern. For the evaluation of rapidly varied flow, the eddy-viscosity input by turbulence model is required instead of the empirical effective viscosity to solve a shallow water equation.

• The Korean Journal of Food And Nutrition
• /
• v.20 no.4
• /
• pp.427-432
• /
• 2007

The texture and descriptive sensory characteristics of a Korean rice cake(Karedduk) with added emulsifier were investigated after 2 and 24 hrs of storage at $5^{\circ}C$. The emulsifier, SP, was added at 0, 0.1, 0.5 and 1% levels to the dry rice flour. In the amylogram, the peak viscosity(P), hot paste viscosity(H) and cold paste viscosity(C) of the rice flour with added emulsifier were higher than those of the control. The texture property analysis by a Texture Analyzer revealed that the springiness, cohesiveness and adhesiveness of the Korean rice cake(Karedduk) with added emulsifier were similar to those of the control, while chewiness, gumminess and hardness were lower compared to the control. Also, the hardness by sensory characteristics was significantly different as compared to the control. Lastly, adding emulsifier to the Korean rice cake(Karedduk) was effective at retarding retrogradation.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1997.10a
• /
• pp.86-92
• /
• 1997

When Lubricants is used under severe running condition, tribological characteristics is very important. I have studied the lubricating oil viscosity, kinds of additives and lubricating oil temperatures were changed. In order to study the effect of oil temperature on the wear of the surface, the temperature of the oil was changed for the same sample. Moreover, the temperatures of three kinds of oils which have very different viscosities at room temperature, were varied while the oil viscosity was unchanged. It was shown from the test results that wear is not greatly affected by the amount of ZnDTP antiwear agent, but E-P additives are less effective against wear than ZnDTP additives. The viscosity of lubricating oil and its tempea-ature greatly affect the wear of the surface. Combining all the wear data with those of the surface strength, it was observed that the higher the load, the lower the scratch of wear, and also in the case of the same running load, the lower the wear, the longer the life of the surface strength.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.27 no.9
• /
• pp.1327-1334
• /
• 2003

Flow characteristics of the fluid laden with many particles in the two-dimensional channel are investigated using the Navier-Stokes equations coupled with the equation of motion of particles by direct numerical simulation. A four-step fractional step method with Crank-Nicolson scheme and ALE technique is used for P2P1 mixed finite element method. The motion and distribution of particles in the fluid is virtually described as a result of direct numerical simulation and the increase of viscosity is compared with theoretical equations. The effect of channel height on the relative viscosity and the tubular pinch effect are discussed.

• Journal of Fashion Business
• /
• v.22 no.3
• /
• pp.30-38
• /
• 2018

Glycolic acid(GA) is well known the most effective cosmetic ingredient on the epidermal remodeling, accelerated desquamation and inhibitory effect on melanin synthesis. The various cosmetic formulations containing GA have not been reported in terms of stability. This study was to investigate the stability of three formulations(gel, cream, and ointment). The stability of obtained formulations was tested chemical and physical characteristics including the composition stability, hot-cool cycling, the variation of pH and viscosity, and the observation of color and odor. The experimental results showed that the gel and cream containing 5% GA, both formulations have proper stability in the centrifugal test, hot-cool cycling test, viscosity, pH stability and the observation of color and odor. On the other hand, the 5% GA ointment did not have stability. We concluded that the formulations of gel and cream are more suitable than ointment to use GA ingredient for developing cosmetic in terms of stability.

• Transactions of the Korean Society of Mechanical Engineers B
• /
• v.23 no.7
• /
• pp.820-830
• /
• 1999

The coupled turbulent flow and solidification is considered in a typical slab continuous easting process using commercial program FIDAP. Standard $k-{\varepsilon}$ turbulence model is modified to decay turbulent viscosity in the mushy zone and laminar viscosity is set to a sufficiently large value at the solid region. This coupled turbulent flow and solidification model also contains thermal contact resistance due to the mold powder and air gap between the strand and mold using an effective thermal conductivity. From the computed flow pattern, the trajectory of inclusion particles was calculated. The comparison between the predicted and experimental solidified shell thickness shows a good agreement.

• Tribology and Lubricants
• /
• v.17 no.4
• /
• pp.335-340
• /
• 2001

It was reviewed that the kinds of lubricating oil, viscosity, temperature and strength of materials affected the wear of the surface heat treatment. When lubricants is used under severe running conditions, their tribological characteristics are very important. We have studied the lubricating oil viscosity, kinds of additives and their amounts, and lubricating oil temperatures were changed. In order to study the effect of oil temperature on the wear of the surface, the temperature of the oil was changed for the same sample. It was shown from the test results that wear is not greatly affected by the amount of ZnDTP (Zinc dialkyl dithio phosphate) antiwear agent, but EP (Extreme pressure) additives are less effective against wear than ZnDTP additives. The viscosity of lubricating oil and its temperature greatly affect the wear of the surface. Combining all the wear data with those of the surface strength, it was observed that the higher the load, the lower the scratch of wear, and also in the case of the same running load, the lower the wear, the longer the life of the surface strength.

• Geomechanics and Engineering
• /
• v.33 no.2
• /
• pp.211-219
• /
• 2023

This study analyzes the changes in the physical properties of grout by irradiating it with ultrasonic energy and assesses the injectability of the grout into deep rock fractures. The materials used in the research are OPC (Ordinary Portland Cement) and MC (Micro Cement), and are irradiated depending on the water/cement ratio. After irradiating the grout with ultrasonic energy, viscosity, compressive strength, and particle size are analyzed, and the results of the particle size analysis were applied to Nick Barton's theory to evaluate the injectability of the grout into deep rock fractures under those conditions. It was found that the viscosity of the grout decreased after ultrasonic wave irradiation, and the rate of viscosity reduction tended to decrease as the water/cement ratio increased. Additionally, an increase in compressive strength and a decrease in particle size were observed, indicating that the grout irradiated with ultrasonic energy was more effective for injection into rock fractures.