• 한국도로학회:학술대회논문집
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• 2010.09a
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• pp.115-120
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• 2010

• 한국도로학회:학술대회논문집
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• 2010.09a
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• pp.109-114
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• 2010

• 한국도로학회:학술대회논문집
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• 2003.10a
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• pp.189-192
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• 2003

• International Journal of Highway Engineering
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• v.7 no.1 s.23
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• pp.11-20
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• 2005

This study examined the correlation between mechanical properties and LMS(Large molecular size) of binders in hot-recycled asphalt mixtures. Hot-recycled asphalt mixtures were manufactured by various mixing methods. Laboratory tests including indirect tensile strength, wheel tracking test and Kim test were performed for each recycled mixture. Gel-permeation chromatography (GPC) analysis was performed for the binders coated on virgin and old (RAP) aggregates separately. For the purpose of binder aging analysis, a round-shaped virgin coarse aggregates (13mm gravel) were introduced in recycled mixtures. This makes possible to distinguish the virgin aggregates from RAP aggregates in recycled mixtures for GPC sampling. Results of GPC showed that there was significant difference in aging level between the binder coated on RAP and that of virgin aggregates in the same recycled mixture. Regression analysis was performed to correlate mechanical properties to LMS ratio. Results showed that most of the mechanical properties had relatively good correlation with LMS. This trend agree with LMS increase up to some degree, but fails for further LMS increase.

• Polymer Science and Technology
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• v.5 no.1
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• pp.47-55
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• 1994

• Polymer Science and Technology
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• v.5 no.2
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• pp.154-163
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• 1994

• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.9
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• pp.1399-1406
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• 2015

The purpose of this study was to investigate the antioxidant activity of Korean traditional soy sauce and its relationship with physicochemical properties. Seventeen samples of soy sauce prepared by using a Korean traditional method were obtained from six provinces of Korea. The most powerful antioxidant activity of soy sauce was ranging from 8.96 to 63.39% for 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, from 0.12 to 2.41 AE mg/mL for ferric reducing antioxidant power (FRAP) value, and from 8.42 to 115.69 TE mg/mL for oxygen radical absorbance capacity (ORAC). Protease activity and total polyphenol contents were highly correlated with antioxidant activities such as DPPH radical scavenging activity and FRAP value (R=0.97). The contents of amino nitrogen were also correlated with DPPH radical scavenging activity (R=0.92), FRAP (R=0.93), and ORAC values (R=0.80). Based on these results, antioxidant activities were highly influenced by protease activity, contents of total polyphenols, and amino nitrogen.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.737-741
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• 2014

Background: In recent years a wide variety of flavonoids or polyphenolic substances have been reported to possess substantial anti-carcinogenic and antimutagenic activities. Grape proanthocyanidins (GPC) are considered as good examples for which there is evidence of potential roles as anti-carcinogenic agents. Methods: A xenograft model was established using H22 cells subcutaneously injected into mice and used to assess different concentrations of grape proanthocyanidins (GPC) and Endostar. Treatments were maintained for 10 days, then levels of vascular endothelial growth factor (VEGF) and microvessel density (MVD) were examined by immunohistochemistry, while VEGF mRNA was determined by real-time PCR in tumor tissue. Results: The expression of MVD and VEGF decreased gradually as the concentration of GPC increased.There was a significant positive correlation between MVD and VEGF. Conclusions: These results suggest that GPC restrains the growth of tumor, possibly by inhibiting tumour angiogenesis.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.111-112
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• 2006

A new MR cylinder with built-in valves using Magneto - Rheological fluid (MR valve) is proposed for fluid power control systems. The MR fluid is a newly developed functional fluid whose obvious viscosity is controlled by the applied magnetic field intensity. This MR cylinder, which is composed of cylinder with small clearance and piston with electromagnet, has the characteristics of simple, compact and reliable structure. This paper presents a method to control the pressure of MR cylinder by using Generalized Predictive Control (GPC) algorithm. The differential pressure is controlled by applying magnetic field intensity to MR fluid. The use of GPC controller is to generate a control sequence by minimizing a cost function in such a way that the future system output is driven close to reference over finite prediction horizons. Experimental results from real time control using GPC method compared with conventional PID control method are also shown in this paper.

• Advances in concrete construction
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• v.12 no.6
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• pp.499-505
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• 2021

Geopolymer binders fascinate the attention of researchers as a replacement to cement binder in conventional concrete. One-ton production of cement releases one ton of carbon-dioxide in the atmosphere. In the replacement of cement by geopolymer material, there are two advantages: one is the reduction of CO₂ in the atmosphere, second is the utilization of Fly ash and Ground granulated blast furnace slag (GGBFS) are by-products from coal and steel industries. This paper focuses on the mechanical properties of steel fiber reinforced geopolymer concrete. The framework considered in this research work is geopolymer source (Fly ash, GGBFS and crimped steel fibre) and alkaline activator which consists of NaOH and Na₂SiO₃ of molarity 8M. Here the Na₂SiO₃ / NaOH ratio was taken as 2.5. The variables considered in this experimental work include Binder content (360,420 and 450 kg/m³), the proportion of Fly ash and GGBS (70-30, 60-40 and 50-50) for three different grades of Geopolymer concrete (GPC) GPC 20, GPC 40 and GPC 60. The percentage of crimped steel fibres was varied as 0.1%, 0.2%, 0.3%, 0.4% and 0.5%. Generally, the inclusion of steel fibres increases the flexural and split tensile strength of Geopolymer concrete. The optimum dosage of steel fibres was found to be 0.4% (by volume fraction).