A new analytical study on stresses around a post-tensioned anchor in rocks with two perpendicular joint sets is presented. The assumptions of orthotropic elastic rock with plane strain conditions are made in derivatio...A new analytical study on stresses around a post-tensioned anchor in rocks with two perpendicular joint sets is presented. The assumptions of orthotropic elastic rock with plane strain conditions are made in derivation of the formulations. A tri-linear bond-slip constitutive law is used for modeling the tendon-grout interface behavior and debonding of this interface. The bearing plate width is also considered in the analysis. The obtained solutions are in the integral forms and numerical techniques that have been used for evaluation. In the illustrative example given, the major principal stress is compressive in the anchor free zone and compressive stress concentrations of 815 k Pa and 727 k Pa(for the anchor load of 300 k N) are observed under the bearing plate and the bond length proximal end, respectively. However, large values of tensile stresses with the maximum of-434 k Pa are formed at the bond length distal end. The results obtained using the proposed solution are compared very those of numerical method(FEM).展开更多
Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2...Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2+ concentrations as the variables. Meanwhile, fed-batch fermentation experiments were conducted. The results show that the three variables are closely related to rhamnolipid production. The optimal cultivation conditions are of 6.4 g/L NaNO3 , 3.1 g/L MgSO4 at 32 ℃, with the maximum rhamnolipid production of 6.6 g/L. The results of fed-batch fermentation experiments show that feeding the oil in two batches can enhance rhamnolipid production. The best time interval is 72 h with the maximum rhamnolipid production of 8.5 g/L. The data are potentially useful for mass production of rhamnolipid on oil waste with this bacterium.展开更多
文摘A new analytical study on stresses around a post-tensioned anchor in rocks with two perpendicular joint sets is presented. The assumptions of orthotropic elastic rock with plane strain conditions are made in derivation of the formulations. A tri-linear bond-slip constitutive law is used for modeling the tendon-grout interface behavior and debonding of this interface. The bearing plate width is also considered in the analysis. The obtained solutions are in the integral forms and numerical techniques that have been used for evaluation. In the illustrative example given, the major principal stress is compressive in the anchor free zone and compressive stress concentrations of 815 k Pa and 727 k Pa(for the anchor load of 300 k N) are observed under the bearing plate and the bond length proximal end, respectively. However, large values of tensile stresses with the maximum of-434 k Pa are formed at the bond length distal end. The results obtained using the proposed solution are compared very those of numerical method(FEM).
基金Project(108100) supported by the Key Program for Science and Technology Research of Ministry of Education of ChinaProjects(50978087, 50908081) supported by the National Natural Science Foundation of China+1 种基金Project(531107011019) supported by the Hunan University Graduate Education Innovation Program, ChinaProject(CX2010B157) supported by the Hunan Provincial Innovation Foundation for Postgraduate students, China
文摘Rhamnolipid production by Pseudomonas aeruginosa ATCC 9027 with waste frying oil as sole carbon source was studied using response surface method. Cultures were incubated in shaking flask with temperature, NO3- and Mg2+ concentrations as the variables. Meanwhile, fed-batch fermentation experiments were conducted. The results show that the three variables are closely related to rhamnolipid production. The optimal cultivation conditions are of 6.4 g/L NaNO3 , 3.1 g/L MgSO4 at 32 ℃, with the maximum rhamnolipid production of 6.6 g/L. The results of fed-batch fermentation experiments show that feeding the oil in two batches can enhance rhamnolipid production. The best time interval is 72 h with the maximum rhamnolipid production of 8.5 g/L. The data are potentially useful for mass production of rhamnolipid on oil waste with this bacterium.
