Simulations of undrained tests were performed in a periodic cell using three dimensional(3D) discrete element method(DEM) program TRUBAL.The effective undrained stress paths are shown to be qualitatively similar to pu...Simulations of undrained tests were performed in a periodic cell using three dimensional(3D) discrete element method(DEM) program TRUBAL.The effective undrained stress paths are shown to be qualitatively similar to published physical experimental results of cohesionless media such as sand.Liquefaction and temporary liquefaction are observed for very loose samples and medium loose samples,respectively.A new micromechanical parameter is proposed to identify whether liquefaction or temporary liquefaction occurs in terms of a redundancy factor.The relationship of redundancy factor and average coordination number is derived theoretically.It is demonstrated that the phase transition dividing the solid-like behaviour and liquid-like behaviour is associated with a redundancy factor of 1,which corresponds to an average coordination number slightly above 4.展开更多
Fourteen yearling standardbred horses were used to test the hypothesis that hay and grain fed as a complete total mixed ration （TMR） cube diet （C） would result in greater average daily gain （ADG）, feed efficien...Fourteen yearling standardbred horses were used to test the hypothesis that hay and grain fed as a complete total mixed ration （TMR） cube diet （C） would result in greater average daily gain （ADG）, feed efficiency （gain to feed ratio, G/F） and apparent digestibility in horses on the TMR diet compared to horses fed the same weight and proportion of hay cubes and grain fed separately （diet HG）. Both diets consisted of 75% forage and 25% ground oats. The forage in both the plain hay cubes and the complete cubes was 80% alfalfa and 20% endophyte-free tall rescue. An additional hypothesis that stomach ulceration would not differ between horses fed either of the two diet treatments was also tested by comparing upper gastric endoscopies before and after 70 days of feeding the experimental diets. Horses fed diet C had greater ADG （P 〈 0.046） while G/F between the two treatments was not significantly different （P 〉 0.065） but showed a trend to be higher in the horses consuming diet C. Apparent digestibility of dry matter and crude protein was not different between the diet treatments, and no major gastric ulceration was found in horses consuming either diet treatment. The results of this study found that a complete cubed diet of 75% hay and 25% oats did not cause stomach ulceration while achieving an acceptable growth rate in yearling horses.展开更多
基金Project(GR/R91588) supported by the Engineering and Physical Sciences Research Council,UK
文摘Simulations of undrained tests were performed in a periodic cell using three dimensional(3D) discrete element method(DEM) program TRUBAL.The effective undrained stress paths are shown to be qualitatively similar to published physical experimental results of cohesionless media such as sand.Liquefaction and temporary liquefaction are observed for very loose samples and medium loose samples,respectively.A new micromechanical parameter is proposed to identify whether liquefaction or temporary liquefaction occurs in terms of a redundancy factor.The relationship of redundancy factor and average coordination number is derived theoretically.It is demonstrated that the phase transition dividing the solid-like behaviour and liquid-like behaviour is associated with a redundancy factor of 1,which corresponds to an average coordination number slightly above 4.
文摘Fourteen yearling standardbred horses were used to test the hypothesis that hay and grain fed as a complete total mixed ration （TMR） cube diet （C） would result in greater average daily gain （ADG）, feed efficiency （gain to feed ratio, G/F） and apparent digestibility in horses on the TMR diet compared to horses fed the same weight and proportion of hay cubes and grain fed separately （diet HG）. Both diets consisted of 75% forage and 25% ground oats. The forage in both the plain hay cubes and the complete cubes was 80% alfalfa and 20% endophyte-free tall rescue. An additional hypothesis that stomach ulceration would not differ between horses fed either of the two diet treatments was also tested by comparing upper gastric endoscopies before and after 70 days of feeding the experimental diets. Horses fed diet C had greater ADG （P 〈 0.046） while G/F between the two treatments was not significantly different （P 〉 0.065） but showed a trend to be higher in the horses consuming diet C. Apparent digestibility of dry matter and crude protein was not different between the diet treatments, and no major gastric ulceration was found in horses consuming either diet treatment. The results of this study found that a complete cubed diet of 75% hay and 25% oats did not cause stomach ulceration while achieving an acceptable growth rate in yearling horses.
