• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2003년도 추계학술대회논문집
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• pp.556-563
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• 2003

This paper presents a method to investigate the characteristics of a hydrodynamic bearing of a HDD spindle motor due to elevated temperature considering the variation of the clearance as well as the lubricant viscosity. Iterative finite element analysis of the heat conduction and the thermal deformation is performed to determine the viscosity and clearance of a hydrodynamic bearing due to elevated temperature until the temperature of the bearing area converges. Proposed method is verified by comparing the calculated temperature with the measured one in elevated surrounding temperature as well as in room temperature. This research shows that elevated temperature changes the clearance as well as the lubricant viscosity of the hydrodynamic bearing of a HDD spindle motor. Once the viscosity and clearance of a hydrodynamic bearing of a HDD spindle motor are determined, finite element analysis of the Reynolds equation is performed to investigate the static and dynamic characteristics of a hydrodynamic bearing of a HDD spindle motor due to elevated temperature. It also shows that the variation of clearance due to elevated temperature is another important design consideration to affect the static and dynamic characteristics of a hydrodynamic bearing of a HDD spindle motor.

• 한국식생활문화학회지
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• 제31권3호
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• pp.243-249
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• 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.

• Geomechanics and Engineering
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• 제29권3호
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• pp.259-267
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• 2022

The rheological and penetration characteristics of sodium alginate and xanthan gum aqueous solutions were analyzed for the development of biopolymer-based injection materials. The results of viscosity measurements for the rheological characteristics analysis show that all aqueous biopolymer solutions exhibit a tendency for shear-thinning, i.e., the apparent viscosity decreases as the shear rate increases. In addition, a regression analysis using several models (Power-law, Casson, Sisko, and Cross) was applied to the shear-thinning fluid analysis results, the highest accuracy was determined by applying the power-law model. The micromodel experiment for the penetration characteristics analysis determined that all biopolymer aqueous solutions show higher pore saturation than water, and that pore saturation tends to increase as the flow rate and concentration increases. When comparing the rheological and penetration characteristics of the biopolymer aqueous solution used in this study, the xanthan gum aqueous solution showed a fully developed shear-thinning tendency, unlike the sodium alginate aqueous solution. This tendency is considered to have the advantage of enhancement injectability and pore saturation.

• 소음진동
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• 제10권1호
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• pp.168-173
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• 2000

This paper deals with the theoretical study on the effect of the viscosity of an adjacent viscous fluid on the characteristics of the torsional vibration of a rod with fixed-free boundary conditions. Expressions for the natural frequency and damping factor have been obtained as functions of the viscosity of the fluid by exact and asymptotic analyses. The results provide quantitative information of the natural frequency reduction and damping rate affected by the fluid viscosity.

• 한국식생활문화학회지
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• 제26권6호
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• pp.709-716
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• 2011

The principal objective of this study was to evaluate the quality characteristics of dried noodles when different concentrations of Loquat (Eriobotyya japonica Lindley) leaf powder (LLP) were added to the wheat flour. The cooking quality, mechanical texture properties, and viscosity were measured, and a sensory evaluation was conducted with the prepared noodles. The gelatinization points of the composite LLP-wheat flours were shown to increase. As measured via amylograph, viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of those samples decreased as the LLP content increased. As increasing amounts of LLP were added, the L and a values were reduced, whereas the b value was increased and the color values, weight, and volume of the cooked noodle increased, as did the turbidity of the soup. With regard to the textural characteristics, the LLP additive increased hardness and cohesiveness, and reduced adhesiveness and springiness. Overall, the noodles prepared with 5% LLP were preferred more than the others, according to the results of our sensory evaluation.

• 한국식품조리과학회지
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• 제22권2호
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• pp.173-180
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• 2006

This study evaluated the quality characteristics of dried noodles made of wheat flour with different concentrations of Dioscorea japonica flour. Cooking quality, mechanical texture properties and viscosity were measured, and sensory evaluation was performed with the prepared noodles. Water binding capacity, solubility and swelling power of the composite Dioscorea japonica flour-wheat flours were higher than those of pure wheat flour. Gelatinization points of the composite Dioscorea japonica flour-wheat flours were increased and initial viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes and maximum viscosity of these composites were decreased, with increasing Dioscorea japonica flour content, as measured by amylograph. With increasing Dioscorea japonica flour content, L and b values were decreased, but a value was increased, for the color values, while weight and volume of the cooked noodles and turbidity of the soup were increased. For the textural characteristics, the addition of Dioscorea japonica flour increased the hardness and decreased the adhesiveness, cohesiveness and springiness. Overall, the noodles made with 10% Dioscorea japonica flour were preferred more than the other noodles, as tested by sensory evaluation.

• 한국식품조리과학회지
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• 제25권3호
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• pp.267-274
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• 2009

The principal objective of this study was to evaluate the quality characteristics of dried wheat flour noodles made with different concentrations of added shrimp powder, for use in elderly foodservice operations. The cooking quality, mechanical textural properties, and viscosity of the noodle samples were measured, and sensory evaluations were conducted with the prepared noodles. As measured by an amylograph, the gelatinization points of the composite shrimp powderwheat flour noodles increased, whereas viscosity at 95$^{\circ}$C, viscosity at 95$^{\circ}$C after 15 minutes, and maximum viscosity values decreased, with increasing shrimp powder content L and b color values were reduced, and the a value increased, with increasing amounts of shrimp powder, Also, greater concentrations of shrimp powder caused increases in the weight and volume of cooked noodles as well as the turbidity of the soup. With regard to the textural characteristics, the shrimp powder additive increased hardness and reduced adhesiveness, cohesiveness, and springiness. Overall, according to the sensory evaluation results, the noodles prepared with 15% shrimp powder were more preferred than the other samples.

• 동아시아식생활학회지
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• 제24권3호
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• pp.375-382
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• 2014

The principal objective of this study was to evaluate the quality characteristics of dried noodles when different concentrations of Boehmeria nivea powder were added to wheat flour. Cooking quality, mechanical textural properties, and viscosity were measured, and sensory evaluation was conducted with the prepared noodles. The gelatinization points of the composite Boehmeria nivea powder-wheat flours increased. The viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of the samples decreased, as the Boehmeria nivea powder content increased as measured via amylography. The L and b values decreased and a value increased with increasing amounts of Boehmeria nivea powder. Further, the color values, weight and volume of the cooked noodles increased, along with the turbidity of the soup with increasing amounts of Boehmeria nivea powder. Regarding textural characteristics, Boehmeria nivea powder additive increased hardness and reduced adhesiveness, cohesiveness, and springiness. Overall, noodles prepared with 15% Boehmeria nivea powder were preferred compared to other noodles, according to the results of our sensory evaluation.

• 한국식품조리과학회지
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• 제24권5호
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• pp.593-600
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• 2008

The principal objective of this study was to evaluate the quality characteristics of dried noodles when different concentrations of Lotus root powder were added to the wheat flour. The cooking quality, mechanical textural properties, and viscosity were measured, and a sensory evaluation was conducted with the prepared noodles. The gelatinization points of the composite Lotus root powder-wheat flours were shown to have increased and the viscosity at $95^{\circ}C$, viscosity at $95^{\circ}C$ after 15 minutes, and maximum viscosity values of those samples were reduced, as the Lotus root powder content was increased as measured via amylography. As increasing amounts of Lotus root powder were added, the L and b values were reduced, and the color values, weight, and volume of the cooked noodles increased, as did the turbidity of the soup. With regard to the textural characteristics, the Lotus root powder additive increased hardness and reduced adhesiveness, cohesiveness, and springiness. Overall, the noodles prepared with 15% Lotus root powder were preferred more than the other noodles, according to the results of our sensory evaluation.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2002년도 proceedings of the second asia international conference on tribology
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• pp.95-96
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• 2002

The operation of proceeding bearing in the conditions of misaligned axis of proceeding and bush leads to the load concentration on the bearing edges causing further mixed lubrication conditions, unstable operation and intensive wear of mating parts. For the design process of proceeding bearing the knowledge of static characteristics determined from the oil film pressure and temperature distribution is very important. For the 3-lobe proceeding bearing, the pressure, temperature and viscosity fields, load capacity, minimum oil film thickness, power loss, oil flow and maximum oil film temperature have been determined by iterative solution of the Reynolds', energy and viscosity equations. The paper introduces the results of theoretical investigations of static characteristics of 3-lobe proceeding bearing operating at misaligned axis of proceeding and bush. An effect of misalignment ratio, length to diameter ratio of the proceeding bearing, the lobe clearance ratio on the static characteristics was investigated. Laminar, adiabatic model of oil film for the solution of Reynolds, energy and viscosity equations was applied.