A single specimen test using the three point single edge notched beam configuration at low temperatures for obtaining hot mix asphalt (HMA) resistance curves is developed.Resistance curves are obtained for mixtures ...A single specimen test using the three point single edge notched beam configuration at low temperatures for obtaining hot mix asphalt (HMA) resistance curves is developed.Resistance curves are obtained for mixtures at six temperature levels of+5,0,-5,-10,-15,and-20 ℃ and three binder contents of 4%,4.5%,and 5%.Crack extension increments during the test are measured by means of an image processing technique using Radon transform and feature extraction.All the specimens exhibit a rising R-curve,indicating ductility and toughening mechanisms in the ductile-quasi brittle fracture of the mixture.It is observed that the reduction of temperature results in a further tendency of the mixture for unstable crack growth and less subcritical crack length.It is also shown that using the binarization process,an automatic index can be developed that can represent the extent of brittleness and extent of the low temperature in which the cracking has occurred.展开更多
Objective: To assess the effect of Danshen 9403 (DS 9403), an effective fraction of Radix Salviae miltiorrhizae (RSM) on healing of bone fracture. Methods: Standardized radial fracture was performed in 120 Wistar ra...Objective: To assess the effect of Danshen 9403 (DS 9403), an effective fraction of Radix Salviae miltiorrhizae (RSM) on healing of bone fracture. Methods: Standardized radial fracture was performed in 120 Wistar rats. The model rats were randomized into four groups: Group A was fed with DS 9403, group B injected with Staphylococcus aureus , group C with normal saline administration, and group D with RSM injection. The treatment began at the first day of fracture. The rats were sacrificed on the day 25, 39 and 50 separately in batches and their intact radii were removed by dissection for detecting load and stress of three point bending test with autograph universal material testing machine (Shimazu, Japan). Results: The parameters of load in DS 9403 treated group on the 39th day and that of stress at 25th, 39th and 50th day were (6.20±1.32)N, (5.71±3.58)N/mm 2, (8.27±2.42)N/mm 2 and (66.25±26.21)N/mm 2 respectively, which were significantly higher than those in other groups, P <0.05. Conclusion: DS 9403 has the action of increasing the strength of fracture broken end.展开更多
文摘A single specimen test using the three point single edge notched beam configuration at low temperatures for obtaining hot mix asphalt (HMA) resistance curves is developed.Resistance curves are obtained for mixtures at six temperature levels of+5,0,-5,-10,-15,and-20 ℃ and three binder contents of 4%,4.5%,and 5%.Crack extension increments during the test are measured by means of an image processing technique using Radon transform and feature extraction.All the specimens exhibit a rising R-curve,indicating ductility and toughening mechanisms in the ductile-quasi brittle fracture of the mixture.It is observed that the reduction of temperature results in a further tendency of the mixture for unstable crack growth and less subcritical crack length.It is also shown that using the binarization process,an automatic index can be developed that can represent the extent of brittleness and extent of the low temperature in which the cracking has occurred.
文摘Objective: To assess the effect of Danshen 9403 (DS 9403), an effective fraction of Radix Salviae miltiorrhizae (RSM) on healing of bone fracture. Methods: Standardized radial fracture was performed in 120 Wistar rats. The model rats were randomized into four groups: Group A was fed with DS 9403, group B injected with Staphylococcus aureus , group C with normal saline administration, and group D with RSM injection. The treatment began at the first day of fracture. The rats were sacrificed on the day 25, 39 and 50 separately in batches and their intact radii were removed by dissection for detecting load and stress of three point bending test with autograph universal material testing machine (Shimazu, Japan). Results: The parameters of load in DS 9403 treated group on the 39th day and that of stress at 25th, 39th and 50th day were (6.20±1.32)N, (5.71±3.58)N/mm 2, (8.27±2.42)N/mm 2 and (66.25±26.21)N/mm 2 respectively, which were significantly higher than those in other groups, P <0.05. Conclusion: DS 9403 has the action of increasing the strength of fracture broken end.