The rheological properties of most liquid in nature are between liquids and solids, including both elastic changes and viscosity changes, that is socalled ＂viscoelastic＂. Dynamic oscillatory test was used to quantit...The rheological properties of most liquid in nature are between liquids and solids, including both elastic changes and viscosity changes, that is socalled ＂viscoelastic＂. Dynamic oscillatory test was used to quantitatively study the distinct viscoelastic behaviors of debris flow slurry in the shear stress conditions for the first time in this study. The debris flow slurry samples were from Jiangjiagou Ravine, Yunnan Province, China. The experimental results were found that at the low and middle stages of shearing, when the angular velocity 09〈72.46 s-1, the loss modulus （G was greater than the storage modulus （G3, i.e. G＂〉G＇. At the late stage of shearing, when the angular velocity co-72.46 s-x, the storage modulus was greater than or equal to the loss G = G, tan -〈 1 （where phase-shift modulus, i.e. ＇ 〉 ＂ angle 5=G＂,/G3, and the debris flow slurry was in a gel state. Therefore, the progress of this experimental study further reveals the mechanism of hyperconcentrated debris flows with a high velocity on low-gradient ravines.展开更多
Stribeck curves have long been used for understanding the lubricating behaviour of oils and greases,and inthe recent years for applications ranging from ball point inks to synovial fluids.In the current work,an attemp...Stribeck curves have long been used for understanding the lubricating behaviour of oils and greases,and inthe recent years for applications ranging from ball point inks to synovial fluids.In the current work,an attempt is madeto show as to what one can read from Stribeck curves of food samples such as chocolate spread,sauce etc.Additionally,the effect of saliva-human and artificial-on the frictional behaviour has also been studied.Thetests were carried out on an MCR Tribometer with a ball-on-three-pin configuration.Polydimethylsiloxane and glasswere used to simulate soft contact conditions that exist in the human mouth.Results from the tribological testsare plotted in the form of extended Stribeck curves,wherein,the friction coefficient is plotted as a function of rotationalspeed.Since the tribometer is capable of speeds as low as a few nanometres per second,it is also possible toobserve the build-up of static friction and its transition into the kinetic regime of friction.Results indicate that certainaspects of the Stribeck curve can offer an insight into the correlation between the frictional behaviour of food to theirsensory feel.展开更多
基金supported by the Youth Talent Team Program of Institute of Mountain Hazards and Environment,CASthe National Natural Science Foundation of China (Grant No.406710260)
文摘The rheological properties of most liquid in nature are between liquids and solids, including both elastic changes and viscosity changes, that is socalled ＂viscoelastic＂. Dynamic oscillatory test was used to quantitatively study the distinct viscoelastic behaviors of debris flow slurry in the shear stress conditions for the first time in this study. The debris flow slurry samples were from Jiangjiagou Ravine, Yunnan Province, China. The experimental results were found that at the low and middle stages of shearing, when the angular velocity 09〈72.46 s-1, the loss modulus （G was greater than the storage modulus （G3, i.e. G＂〉G＇. At the late stage of shearing, when the angular velocity co-72.46 s-x, the storage modulus was greater than or equal to the loss G = G, tan -〈 1 （where phase-shift modulus, i.e. ＇ 〉 ＂ angle 5=G＂,/G3, and the debris flow slurry was in a gel state. Therefore, the progress of this experimental study further reveals the mechanism of hyperconcentrated debris flows with a high velocity on low-gradient ravines.
文摘Stribeck curves have long been used for understanding the lubricating behaviour of oils and greases,and inthe recent years for applications ranging from ball point inks to synovial fluids.In the current work,an attempt is madeto show as to what one can read from Stribeck curves of food samples such as chocolate spread,sauce etc.Additionally,the effect of saliva-human and artificial-on the frictional behaviour has also been studied.Thetests were carried out on an MCR Tribometer with a ball-on-three-pin configuration.Polydimethylsiloxane and glasswere used to simulate soft contact conditions that exist in the human mouth.Results from the tribological testsare plotted in the form of extended Stribeck curves,wherein,the friction coefficient is plotted as a function of rotationalspeed.Since the tribometer is capable of speeds as low as a few nanometres per second,it is also possible toobserve the build-up of static friction and its transition into the kinetic regime of friction.Results indicate that certainaspects of the Stribeck curve can offer an insight into the correlation between the frictional behaviour of food to theirsensory feel.
