To satisfy the mechanical and biological requirement of porous bone substitutes, porous Ti with two different pore sizes designed in advance was fabricated by the space-holder sintering process. Mechanical properties ...To satisfy the mechanical and biological requirement of porous bone substitutes, porous Ti with two different pore sizes designed in advance was fabricated by the space-holder sintering process. Mechanical properties of the porous Ti were explored via room temperature compressive tests. The pore sizes and shapes are uniform throughout the specimens with porosities ranging from 36% to 63%. The compression strength and the elastic modulus are in the range from 94.05 to 468.57 MPa and 2.662 to 18 GPa, respectively. It is worth noting that the relationship between the compressive strength and the porosities is completely linear relation beyond the effect of pore size distributions on the mechanical properties. The value of the constant C achieved from the Gibson-Ashby model suggests that the pore sizes affect the yield strength of the porous Ti and the values of density exponent （n） for porous Ti with two different pore sizes are higher than 2, which suggests that the deformation mode of the porous Ti with a porosity ranging from 36% to 63% is mainly buckling of the cell struts.展开更多
The paper considers the main causes of the difficulties of zootechnics in Friulian mountains （Italy）, evaluating different approaches. From the methodological point of view, there were analyzed the different aspects...The paper considers the main causes of the difficulties of zootechnics in Friulian mountains （Italy）, evaluating different approaches. From the methodological point of view, there were analyzed the different aspects that causes the present crisis in this territorial contest and that, contextually, at the same time, prevent its recovery. The procedural pathway followed these steps： analysis, synthesis, comparison, deduction and induction. The results showed that there are technical, social, environmental, political and infra-structural aspects that cause this stated economical emergency for the compartment. A ＂new rural paradigm＂, in particular, the multi-functionality of the farm seems to be the road to the progress of mountain regions. Unfortunately, there are no definitive universal answers, hut individual solutions that should be investigated and calibrated for specific local resources.展开更多
基金Project （2012CB619100） supported by the National Basic Research Program of China
文摘To satisfy the mechanical and biological requirement of porous bone substitutes, porous Ti with two different pore sizes designed in advance was fabricated by the space-holder sintering process. Mechanical properties of the porous Ti were explored via room temperature compressive tests. The pore sizes and shapes are uniform throughout the specimens with porosities ranging from 36% to 63%. The compression strength and the elastic modulus are in the range from 94.05 to 468.57 MPa and 2.662 to 18 GPa, respectively. It is worth noting that the relationship between the compressive strength and the porosities is completely linear relation beyond the effect of pore size distributions on the mechanical properties. The value of the constant C achieved from the Gibson-Ashby model suggests that the pore sizes affect the yield strength of the porous Ti and the values of density exponent （n） for porous Ti with two different pore sizes are higher than 2, which suggests that the deformation mode of the porous Ti with a porosity ranging from 36% to 63% is mainly buckling of the cell struts.
文摘The paper considers the main causes of the difficulties of zootechnics in Friulian mountains （Italy）, evaluating different approaches. From the methodological point of view, there were analyzed the different aspects that causes the present crisis in this territorial contest and that, contextually, at the same time, prevent its recovery. The procedural pathway followed these steps： analysis, synthesis, comparison, deduction and induction. The results showed that there are technical, social, environmental, political and infra-structural aspects that cause this stated economical emergency for the compartment. A ＂new rural paradigm＂, in particular, the multi-functionality of the farm seems to be the road to the progress of mountain regions. Unfortunately, there are no definitive universal answers, hut individual solutions that should be investigated and calibrated for specific local resources.
