• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.19 no.4
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• pp.313-320
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• 2007

In this paper, the experimental study has been carried out to investigate the reliability lifetime of two bearing units based on the oil temperature. Measurements for the oil temperature as well as the bearing temperature during normal operation were performed to study the effects of oil viscosity and oil submergence percentages in the two bearing units. The optimal lubrication condition to increase the lifetime of the bearing unit A was found that its viscosity and submergence percentage were VG32 and 25%, respectively. For the bearing unit B, when the oil viscosity and submergence percent were VG32 and 75%, the lubrication condition was the most efficient. Finally, the adjusted rating times of both the bearing units were calculated to be over 28,000 h, which is greater than the minimum adjusted rating times of 25,000 h. Therefore, they satisfied the regulated lifetime of API 610.

• Carbon letters
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• v.16 no.2
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• pp.132-134
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• 2015

When manufacturing bulk graphite, pores develop within the bulk during the carbonization process due to the volatile components of the fillers and the binders. As a result, the physical properties of bulk graphite are inferior to the theoretical values. Impregnants are impregnated into the pores generated in the carbonization process through pressurization and/or depressurization. The physical properties of bulk graphite that has undergone impregnation and re-carbonization processes are outstanding. In the present study, a green body was manufactured by molding with natural graphite flakes and phenolic resin at 45 MPa. Bulk graphite was manufactured by carbonizing the green body at 700 and it was subsequently impregnated with impregnants having viscosity of 25.0 cP, 10.3 cP, and 5.1 cP, and the samples were re-carbonized at $700^{\circ}C$. The above process was repeated three times. The open porosity of bulk graphite after the final process was 22.25%, 19.86%, and 18.58% in the cases of using the impregnant with viscosity of 25.0 cP, 10.3 cP, and 5.1 cP, respectively.

• Journal of the Korean Society of Food Culture
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• v.20 no.3
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• pp.299-304
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• 2005

This study investigated the feasibility of the bread making process with the mixture of the functional rice flour. The bread was manufactured with 20, 30 or 40% functional rice flour with increasing and wheat flour. Gelatinization characteristics of the rice starch was examined by differential scanning calorimetry(DSC). Coated with soluble dietary fiber rice showed the highest gelatinization enthalphy among functional rices and other functional rices were similar to normal rice. in the viscosity point of view. generally the viscosity related to the addition ratio. The most viscose case was 30% Sangwhang rice but in fermented with monascus ruber rice case, viscosity was low even with 40% case because of the transformation of the starch granules. In sensory evaluation, the highest sensory scores for the uniformity of pore size and flavor were obtained when sangwhang rice flour content was 20%. The textual study was mainly focused on the hardness, cohesiveness, adhesiveness, springiness, chewiness. Textural characteristics of functional rice bread crumb bakedwith 20% coated with soluble dietary fiber rice, 20% sangwhang was low in hardness, chewiness and gumminess. Therefore, Sangwhang rice flour 20%, Monascous ruber 20% and Coated soluble dietary fiber rice 20% were considered to be the most suitable addition ratio for the rice breads.

• Advances in concrete construction
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• v.13 no.5
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• pp.395-410
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• 2022

This study collected the results of material tests and full-scale pumping tests using 127 types of concrete mixtures with compressive strength ranging from 24 to 200 MPa. The results of 242 material tests showed high correlations between the viscosity of the lubricating layer and concrete, between the slump and the yield stress of concrete, between the water-binder ratio and the viscosity of lubricating layer, and between the time required to reach 500 mm of slump flow and concrete viscosity. Based on these correlations, pumpability was predicted using 101 pumping test conditions, and their accuracy was compared to the actual test results. When the rheological properties of concrete and the lubricating layer were directly measured, the prediction result showed the highest accuracy. A high accuracy can be achieved when the measured viscosity of the lubricating layer, a key determinant of concrete pumpability, is reflected in the prediction of pumpability. When measuring rheological properties is difficult, the slump test can be used to quantitatively predict the pumpability despite the lower accuracy than those of other prediction methods.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.03a
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• pp.299-306
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• 1998

• Tribology and Lubricants
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• v.31 no.1
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• pp.28-34
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• 2015

This paper addresses the problems of using anti-freeze lubricants for different machines that must function at extremely low temperatures during winter operation in the Republic of Sakha (Yakutia). We discuss the possibility of obtaining anti-freeze base oils from Talakan crude oil, an area with major oil and gas deposits of the Republic of Sakha, and also provide the trade and technological classification of Talakan crude oil. We propose two different schemes for processing Talakan crude oil: the fuel scheme (obtaining light and heavy fractions as a fuel oil) and the base oil scheme (obtaining light fractions and base oils). We investigate the influence of pour point depressants on alkyl-methacrylate base on the low-temperature properties of the fractions obtained from Talakan crude oil and Korean base oils, and establish the optimal concentration of pour point depressants. We compare the properties of these fractions with the low-temperature properties of Korean base oils and find that the commercial oil "Ravenol 0W-40" provides optimistic results. We obtain oil with a pour point of minus $50^{\circ}C$ and a viscosity index greater than 100. The Design of Experiment was used to establish the optimum composition of the pour point depressants and the base oil S-8 to obtain lubricant oil with a kinematic viscosity of 17 cSt, viscosity index of 208, and a pour point of minus $64^{\circ}C$.

• Korean journal of food and cookery science
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• v.24 no.5
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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.

• International Journal of Highway Engineering
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• v.16 no.2
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• pp.35-41
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• 2014

PURPOSES : Surface treatment is a favorable method in the pavement preventive maintenance. This study (Part I) aimed to develop the low viscosity filling material for waterproof characteristics and high penetrable and weather resistance, and a series of companion study (Part II) presents the coating characteristics and performance analysis using field and lab tests. METHODS : Hydrophobic characteristics of the advanced surface treatment material are observed and measured the filling depth and the permeability for sand and asphalt pavement specimen using the water absorption test and permeability test, X-RAY CT test. Color difference for the weather resistance using ultraviolet ray accelerated weathering test is compared with asphalt pavement specimens. RESULTS : The developed material shows the decreased water absorption and increased impermeable effect because of the hydrophobic characteristics. It is found that the filling depth is about 6mm and weather resistance is better than asphalt pavement specimen. CONCLUSIONS : The advanced hydrophobic - low viscosity filling treatment material is developed in this study (Part I) to improve the waterproof characteristics and high filling capacity and weather resistance for the pavement preventive maintenance.

• Preventive Nutrition and Food Science
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• v.13 no.1
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• pp.40-44
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• 2008

Response surface methodology (RSM) was used for analyzing the manufacturing process of Prunus mume extract-added vinegared red pepper paste (maesil chokochujang) with respect to sensory quality properties. Experiments were carried out according to a central composite design, selecting the amount of kochujang, amount of maesil extract, and type of sugar in the mixture as independent variables; sensory attributes such as flavor, taste, color, and mouthfeel viscosity as response variables. The polynomial models developed by RSM for sensory color and mouthfeel viscosity were highly effective to describe the relationships between the factors studied and the responses. The estimated response surfaces confirmed that the amount of kochujang had a positive effect on color (p<0.001) whereas the amount of maesil extract had a positive effect on mouthfeel viscosity (p<0.001). Increase in the amount of kochujang led to a sharp increase of the sensory score on color at all the maesil extract and sugar type levels. On the other hand, increase in the amount of maesil extract caused a sharp increase in the mouthfeel viscosity value regardless of kochujang concentration and type of sugar. The differences among samples made with different types of sugar were not significant (p>0.05).

• Journal of applied mathematics & informatics
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• v.26 no.1_2
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• pp.161-176
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• 2008

The effect of variable viscosity on MHD mixed convection Hiemenz flow over a thermally stratified porous wedge plate has been studied in the presence of suction or injection. The wall of the wedge is embedded in a uniform Darcian porous medium in order to allow for possible fluid wall suction or injection and has a power-law variation of the wall temperature. An approximate numerical solution for the steady laminar boundary-layer flow over a wall of the wedge in the presence of thermal diffusion has been obtained by solving the governing equations using numerical technique. The fluid is assumed to be viscous and incompressible. Numerical calculations are carried out for different values of dimensionless parameters and an analysis of the results obtained shows that the flow field is influenced appreciably by the magnetic effect, variable viscosity, thermal stratification and suction / injection at wall surface. Effects of these major parameters on the transport behaviors are investigated methodically and typical results are illustrated to reveal the tendency of the solutions. Comparisons with previously published works are performed and excellent agreement between the results is obtained.