• Journal of Advanced Marine Engineering and Technology
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• v.15 no.1
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• pp.59-70
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• 1991

Rupture of lubricant film, thermal characteristics, and variation of viscosity are very important factors to evaluate the performance of journal bearing. Variation of external conditions, load or rotational speed, largely influence these facters. For example, if rotational speed increases lubricant bulk temperature increases and viscosity drops. In this paper the effect of rotational speed variation on the characteristics of lubricant film in a journal bearing is investigated by experiment and theoretical analysis. It has been measured number of lubricant film rupture and lubricant bulk temperature form journal bearing which have been established at the various operating speed of shaft. The range of speed variation is from 900rpm to 2100rpm. Theoretical analysis has been carried out for rupture of lubricant film and thermal characteristics, and these results are compared with experimental results.

• Tribology and Lubricants
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• v.3 no.1
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• pp.26-30
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• 1987

The effects of high viscosity polybutene lubricant on the asperity contacts between a flat washer and a ball were tested using three balls/two flat washers rotational apparatus. The asperity contacts were dependent on the ratio of EHD flim thickness (h) and surface roughness($\sigma$). The viscosity-pressure coefficient of lubricant gave a significant effect on the film thickness and thereby on h/$\sigma$ ratio.

• Journal of the Korean Graphic Arts Communication Society
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• v.12 no.1
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• pp.145-157
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• 1994

Litho printing ink vehicles based on rosin modified phenolic are faster drying, have better durability, are harder and glosser and have greater resistance to water than ones based on ester gums. Ink-Water balance and rheological properties are important in litho printing process. These physical properties is concerned with molecular weight of Resin to use vehicle. So this paper was studied about the effects of changing molecular weight of Rosin modified phenolic on surface tension, viscosity, pseudoplasticity and printability of Litho Inks. The results were as follows. 1) The surface tension of model inks depended on the molecular \veight of the resin : Dispersion componnent of ink increase but non dispersion component decrease as molecular weight of Resin increase. 2) Water pick-up of litho ink is more fast balance, using low molecular weight of Resin. 3) Viscosity, Yield value and Newtonian value of model inks increase as molecular weight of Resin increase. 4) The litho ink prepared with the modified phenolic of which molecular weight is about 20000 showed the highest printing density and gloss.

• Membrane and Water Treatment
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• v.9 no.1
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• pp.1-7
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• 2018

The principal objective of this study is to investigate the effect of Polyethylene Glycol (PEG) crosslinking in Polyvinylidene Fluoride (PVDF) in immobilization of Fe and bimetallic Fe/Cu and Cu/Fe zero valent particles on the membrane and its efficiency on removal of nitrate in wastewater. PVDF/PEG polymer solution of three weight compositions was prepared to manipulate the viscosity of the polymer. PEG crosslinking was indirectly controlled by the viscosity of the polymer solution. In this study, PEG was used as a modifier of PVDF membrane as well as a cross-linker for the immobilization of the zero valent particles. The result demonstrates improvement in immobilization of metallic particles with the increase in crosslinking of PEG. Nitrate removal efficiency increases too.

• Computers and Concrete
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• v.20 no.3
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• pp.297-310
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• 2017

A CFD software was used to simulate free surface flow of SCC in the T-Box test. In total, seven simulations were developed to study the effect of rheological parameters on the non-restricted flow performance of SCC in both horizontal and vertical directions. Different suspending fluids having five plastic viscosity values between 10 and 50 Pa.s, three yield stress values between 14 and 75 Pa, one density of $2500kg/m^3$, and one shear elasticity modulus of 100 Pa were considered for suspension of 178 spherical particles of 20-mm diameter and $2500kg/m^3$ density. The results of the simulations are found to correlate well to changes in rheological parameters of the suspending fluid. Plastic viscosity was shown to be the most dominant parameter affecting flowability and dynamic stability compared to the yield stress. A new approach was proposed to evaluate performability of SCC based on a trade-off between flowability and dynamic stability.

• Fibers and Polymers
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• v.5 no.2
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• pp.145-150
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• 2004

Blends of poly(phenylene sulfide) (PPS) and polyethylene, either linear low density polyethylene (LLDPE) or metallocene-catalyzed polyethylene (MPE), that were prepared by melt blending, were investigated. From the rheological properties as determined by capillary rheometry, the melt viscosity of both PPS/LLDPE and PPS/MPE blends was low when PE was in dispersed phase, but high melt viscosity was observed for both blends with PPS in dispersed phase. Significant differences depending on the composition were found in the mechanical properties such as percent elongation at break and notched Izod impact strength. In addition, dispersed phase morphology of the blends was analyzed by a scanning electron microscope (SEM), together with brief discussion about the difference between them.

• Culinary science and hospitality research
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• v.2
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• pp.183-207
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• 1996

This study is to investigate the effect on the quality and properties of bread affected by licorice extract addition. The measurements of the farinograph, extensograph and amylograph on dough are carried out. And the evaluations of volumetric changes during fermentation, shape of bread crumb, sensory test, firmness are obtained. The obtained results are as follows. 1. Proximate compositions of licorice extract are as follows: moisture 73.7%, crude protein 4.1%, crude lipid 2.8%, crude ash 1.4%. 2. Water absoorption, arrival time dough development time mechanical tolerence index and valorimeter value are increased but stability is decreased with the addition of licorice extract. 3. The resistance to extension is increased but extensibility is decreased with the addition of licorice extract. 4. The initial pasting and highest viscosity temperatures are not affected but the highest viscosity is steepy decreased over 1.0% addition of licorice extract. 5. The volume of dough during fermentation and specific volume of bread is decreased with the addition of licorice extract. 6. The grain of bread is to be rough and irregular and the firmness is increased with the addition of licorice extract. 7. The records of sensory test are decreased with the addition of licorice extract.

• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.1104-1110
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• 2003

The present study investigates the hemorheological characteristics of blood flow with applying vibration to a non-aggregating red blood cell suspension. In order to obtain the non-aggregating RBC suspension, blood samples were treated with vibration at a specified condition, which viscosities were taken before and after the treatment, respectively. The viscosity of the blood samples after treatment was higher than before treatment. These treated blood samples were forced to flow through a capillary tube that was vibrated perpendicularly to the direction of the flow. The experimental results showed that vibration caused a reduction of the flow resistance of the non-aggregated blood. The reduction of the flow resistance was strongly dependent on both frequency and amplitude of vibration. These results show potential in treating various diseases in the microcirculation associated with blood cell aggregation.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2000.11a
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• pp.850-853
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• 2000

It is well-known that Electro-rheological(ER) fluid is a material(suspension) which shows the dramatic change of rheological properties under an electric field. Using these properties, the concept that variable apparent viscosity of ER fluid could be applicable to the polishing for micro parts was introduced. It was investigated that how it works for polishing and how it affects ER effect when abrasives were mixed with an ER fluid. Therefore a few structures for polishing using ER fluid was suggested and evaluated by means of experiments. In this paper, fundamental mechanism and experimental results are described.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1394-1397
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• 2003

The first thing in developing injection molding and extrusion with microcellular foaming process is to get a grip on one phase state's rheology of gas and polymer solution. Understanding rheology is essential to design mold or die. and it is so important to control the condition of process. Also, this data is got the utmost out of simulation carrying out. In this paper, we will see the measurement of rheology in one phase that mixed polypropylene which contains talc with carbon dioxide of super critical fluid state, and will compare its result with the simulation result.