• International Journal of Highway Engineering
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• v.1 no.2
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• pp.121-133
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• 1999

This study was based on the evaluation of 9 asphalts that were produced in five major Korean refineries. The study was concentrated to identify the problems of the current asphalt specification (KS M 2201) and to determine the ranges of visco-elastic asphalt behavior. As a conventional asphalt property. asphalt penetration, ring and ball(R&B) softening point, asphalt viscosity, and flash point of asphalt were measured. Also Dynamic Shear Rheometer (DSR) were used to evaluate visco-elastic properties of asphalts in the $-20^{\circ}C$ through $30^{\circ}C$ temperature range. These properties before and after the short-term (RTFO) and long-term (PAV) aging were compared and analyzed to achieve the research objectives. The conclusion from this study can be summarized by the followings. The low temperature rheological behavior of all the straight asphalt from five major Korean refineries is similar regardless of asphalt grade. In the mean while, the rheological behavior at high and intermediate temperature of Korean straight asphalt varies depending on asphalt grade.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.608-615
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• 2017

The objective of this study was to evaluate the physicochemical, structural, and rheological properties of new domestic potato cultivars ('Goun', 'Sebong', and 'Jinsun') against the foreign potato cultivar 'Atlantic'. Based on the results obtained from scanning electron micrograph, X-ray, and Fourier transform infrared spectrum analyses, the structural properties of all potato flours were not considerably different. Rapid visco analyzer analyses showed that the setback viscosities of 'Goun', 'Sebong', and 'Jinsun' were significantly lower than that of 'Atlantic'. For steady shear rheological properties, potato flour dispersions showed shear-thinning behaviors (n=0.45~0.49) at $25^{\circ}C$. Apparent viscosity and consistency index of 'Atlantic' were similar to those of 'Sebong' and 'Jinsun'. For dynamic shear rheological properties, storage modulus (G′) and loss modulus increased, whereas complex viscosity (${\eta}^*$) was reduced with increasing frequency from 0.63 to 62.8 rad/s. G′ and ${\eta}^*$ values of 'Jinsun' were significantly higher than those of the other potato cultivars.