The Experts below are selected from a list of 21165 Experts worldwide ranked by ideXlab platform
Milivoj K. Burn - One of the best experts on this subject based on the ideXlab platform.
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measurement of fiber matrix Interfacial Shear stress at elevated temperatures
Journal of the American Ceramic Society, 1992Co-Authors: Milivoj K. BurnAbstract:An apparatus for measurement of the fiber/matrix Interfacial Shear stress at temperatures up to 1100° is described. Equipment was used to measure Interfacial properties as a function of temperature in two ceramic-matrix composites and one metal-matrix composite. In the composites where the thermal expansion of the matrix was higher than that of the fiber, the Interfacial Shear stress decreased with temperature. The opposite trend was observed in a system with low matrix thermal expansion. The change of the Interfacial Shear stress with temperature of all the composites studied can be fully explained by considering the fiber/matrix expansion differences.
Y. Bian - One of the best experts on this subject based on the ideXlab platform.
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Interfacial Shear stress concentration in FRP-strengthened beams
Composite Structures, 2001Co-Authors: Mohamed Maalej, Y. BianAbstract:Abstract This paper reports the results of an experimental programme designed to study the Interfacial Shear stress concentration at the plate curtailment of reinforced concrete (RC) beams strengthened in flexure with externally bonded carbon fibre-reinforced polymer (CFRP). Specifically, the study looks at the relationship between the CFRP plate thickness and the Interfacial Shear stress concentration at the plate curtailment, the failure modes of the CFRP-strengthened beams as well as the efficiency of the CFRP external reinforcing system. Comparing the experimental results with existing models' predictions is another objective of this study. The experimental programme included five RC beams 115 mm ×150 mm in cross-section and 1500 mm in length. Four of the RC beams were reinforced externally with CFRP plates of different thicknesses. Tests in this study showed that the thickness of CFRP plate affects not only the load-carrying and deflection capacities of the strengthened beam, but also the Shear stress concentration at the CFRP/concrete interface and the beam failure mode.
Gerald G Fuller - One of the best experts on this subject based on the ideXlab platform.
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interaction of human whole saliva and astringent dietary compounds investigated by Interfacial Shear rheology
Food Hydrocolloids, 2008Co-Authors: D Rossetti, Gleb E Yakubov, Jason R Stokes, Annmarie Williamson, Gerald G FullerAbstract:Human whole saliva (HWS) is a complex physiological secretion that performs a number of essential functions such as protection of oral health, lubrication of mouth tissues, as well as predigestion of food. In addition, saliva forms the perireceptor environment of the oral cavity and, by its interactions with food and beverages, influences the transduction of aroma, taste and tactile (mouthfeel) perceptions. We investigate and report the impact of addition of compounds commonly found in oral health and beverage products (sodium dodecyl sulphate (SDS), citric acid and tea polyphenols: epigallocatechin gallate (EGCG), epicatechin (EC), rutin) on the Interfacial Shear elasticity of HWS obtained from a single subject. The aim of this work is to probe the relationship between surface Shear elasticity of saliva and the astringent (puckering-like) mouthfeel arising from the consumption of products containing the investigated ingredients. Saliva proteins are extremely surface active and adsorb to the air-liquid interface to form a high-elastic "solid-like" surface film. Our findings show that the Interfacial Shear elasticity G of saliva is significantly reduced when mixed with citric acid, SDS or a tea polyphenol containing a galloyl ring in the molecule (EGCG). These results support the hypothesis that astringency arises from aggregation of salivary proteins, thereby reducing lubrication of oral tissues. Minor or no effect is observed from the interaction of saliva with EC or rutin. Furthermore, we investigate the possibility of using mucins as a simple model for saliva. Two selected mucins, tested at different concentrations and ionic strength, failed to mimic the elastic Interfacial behaviour shown by saliva. (C) 2007 Elsevier Ltd. All rights reserved.
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interaction of human whole saliva and astringent dietary compounds investigated by Interfacial Shear rheology
Food Hydrocolloids, 2008Co-Authors: D Rossetti, Gleb E Yakubov, Jason R Stokes, Annmarie Williamson, Gerald G FullerAbstract:Human whole saliva (HWS) is a complex physiological secretion that performs a number of essential functions such as protection of oral health, lubrication of mouth tissues, as well as predigestion of food. In addition, saliva forms the perireceptor environment of the oral cavity and, by its interactions with food and beverages, influences the transduction of aroma, taste and tactile (mouthfeel) perceptions. We investigate and report the impact of addition of compounds commonly found in oral health and beverage products (sodium dodecyl sulphate (SDS), citric acid and tea polyphenols: epigallocatechin gallate (EGCG), epicatechin (EC), rutin) on the Interfacial Shear elasticity of HWS obtained from a single subject. The aim of this work is to probe the relationship between surface Shear elasticity of saliva and the astringent (puckering-like) mouthfeel arising from the consumption of products containing the investigated ingredients. Saliva proteins are extremely surface active and adsorb to the air-liquid interface to form a high-elastic "solid-like" surface film. Our findings show that the Interfacial Shear elasticity G of saliva is significantly reduced when mixed with citric acid, SDS or a tea polyphenol containing a galloyl ring in the molecule (EGCG). These results support the hypothesis that astringency arises from aggregation of salivary proteins, thereby reducing lubrication of oral tissues. Minor or no effect is observed from the interaction of saliva with EC or rutin. Furthermore, we investigate the possibility of using mucins as a simple model for saliva. Two selected mucins, tested at different concentrations and ionic strength, failed to mimic the elastic Interfacial behaviour shown by saliva. (C) 2007 Elsevier Ltd. All rights reserved.
K S Leong - One of the best experts on this subject based on the ideXlab platform.
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effect of beam size and frp thickness on Interfacial Shear stress concentration and failure mode of frp strengthened beams
Composites Science and Technology, 2005Co-Authors: Marwa Maalej, K S LeongAbstract:Abstract This paper presents the results of an experimental research program designed to study the Interfacial Shear stress concentration at FRP cut-off points and the failure modes of RC beams strengthened in flexural with externally bonded carbon fibre reinforced polymer (CFRP) sheets. The test variables include the RC beam size and the CFRP thickness. The objectives are to investigate the effects of reduced scaling and the influence of the FRP thickness on the Interfacial Shear stresses and the failure modes of the FRP-strengthened beams as well as to confirm the validity of proposed analytical models for the prediction of intermediate crack-induced Interfacial debonding and Interfacial Shear stresses at FRP cut-off points. The experimental works involve flexural testing of 17 FRP-strengthened beams under third-point loading. Three different effective beam depths and two CFRP thicknesses are considered. Two main conclusions are drawn from this study. First, the increase in beam size and/or FRP thickness is found to increase the Interfacial Shear stresses in the FRP curtailment region. In the present study, however, the peak Shear stresses are not high enough to cause a change in the failure mode of the beams. Second, the size of the beam does not seem to affect the extent (measured in term of a strengthening ratio, SR) to which a reinforced concrete beam can be strengthened.
L.m. Portela - One of the best experts on this subject based on the ideXlab platform.
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Prediction of the Interfacial Shear-stress in vertical annular flow
International Journal of Multiphase Flow, 2009Co-Authors: R.j. Belt, J.m.c. Van’t Westende, L.m. PortelaAbstract:Many improvements of the Wallis correlation for the Interfacial friction in annular flow have been proposed in the literature. These improvements give in general a better fit to data, however, their physical basis is not always justified. In this work, we present a physical approach to predict the Interfacial Shear-stress, based on the theory on roughness in single-phase turbulent pipe flows. Using measured Interfacial Shear-stress data and measured data on roll waves, which provide most of the contribution to the liquid film roughness, we show that the Interfacial Shear-stress in vertical annular flow is in very close agreement with the theory. We show that the sand-grain roughness of the liquid film is not equal to four times the mean film thickness, as it is assumed in the Wallis correlation. Instead, the sand-grain roughness is proportional to the wave height, and the proportionality constant can be predicted accurately using the roughness density (or solidity). Furthermore, we show that our annular flow, which is in similar conditions to others in the literature, is fully rough. Hence, the bulk Reynolds number should not appear in the prediction of the Interfacial friction coefficient, as is often done in the improvements of the Wallis correlation proposed in the literature.
