Modelling the Rheological Properties of Epoxy Asphalt Concrete

This paper presents an investigation into modelling the rheological properties of epoxy asphalt concrete( EAC) by using the Huet-Sayegh model. Complex modulus tests were conducted on EAC specimens at various temperature and loading frequency conditions. Dynamic modulus and phase angles obtained from the complex modulus tests were used in the construction of the Huet-Sayegh model. The dynamic modulus master curve was developed by the Huet-Sayegh model as well as the Burgers model for comparison purpose. The results showed that EAC exhibits typical rheological behavior whose dynamic modulus decreases with the increase of temperature while increases with the increase of frequency,and phase angles increase with the decrease of frequencies and the increase of temperatures. The Huet-Sayegh model predicts the dynamic modulus master curve of EAC very well and much better than the Burgers model over a wide range of frequencies.

A novel technology to reduce astringency of tea polyphenols extract and its mechanism

Objective:Tea polyphenols are natural extracts used widely throughout the world.However,the severe astringency of tea polyphenols has reduced patient compliance.Based on the analysis of the formation mechanism of astringency,this paper hopes to propose a new method to control the astringency of tea polyphenols and improve patient compliance without changing its effect.Methods:Artificial saliva was used to prepare the tea polyphenols solution with different p H,using bcasein to imitate salivary protein,and preparing 1.2 mg/m L b-casein solution.A fluorescence quenching test was used to study the interaction between tea polyphenols and b-casein,combined with the stability test results of the compound,we can choose the p H with weak binding but good stability as the best p H for masking astringency.The taste-masking tablets were prepared under the best p H conditions,and the Xinnaojian Original Tablets were prepared according to the conventional preparation method.The disintegration time limit and solubility were tested respectively.The astringency of Xinnaojian original tablets and taste-masking tablets was evaluated by visual analogue scale(VAS).Results:The result of the fluorescence quenching test prompted that the combination force was the weakest when the p H was 4.9.Further synchronous fluorescence analysis showed that an increase in p H resulted in a decrease of the binding sites between tea polyphenols and b-casein,and this decrease was closely related to changes in tryptophan residues in b-casein.Both original and taste-masking Xinnaojian Tablets were prepared.Volunteers’VAS scores illustrated that the astringency improved significantly with the masking tablets(P<0.05).Conclusion:This p H-adjusting masking treatment had little effect on the recovery of polyphenols from the tablets or the dissolution of the tablets.This study provides a novel and feasible astringency masking technology for tea polyphenols and its preparation.