This research investigated the combined effects of addition of Bi and Sb elements on the microstructure,thermal properties,ultimate tensile strength,ductility,and hardness of Sn−0.7Ag−0.5Cu(SAC0705)solder alloys.The r...This research investigated the combined effects of addition of Bi and Sb elements on the microstructure,thermal properties,ultimate tensile strength,ductility,and hardness of Sn−0.7Ag−0.5Cu(SAC0705)solder alloys.The results indicated that the addition of Bi and Sb significantly reduced the undercooling of solders,refined theβ-Sn phase and extended the eutectic areas of the solders.Moreover,the formation of SbSn and Bi phases in the solder matrix affected the mechanical properties of the solder.With the addition of 3 wt.%Bi and 3 wt.%Sb,the ultimate tensile strength and hardness of the SAC0705 base alloy increased from 31.26 MPa and 15.07 HV to 63.15 MPa and 23.68 HV,respectively.Ductility decreased due to grain boundary strengthening,solid solution strengthening,and precipitation strengthening effects,and the change in the fracture mechanism of the solder alloys.展开更多
The upper and lower portions of Musa sapientum pseudo-stem sheaths were exposed in four types of treatments： pectin decomposing bacteria, magnesium oxide （MgO）, both pectin decomposing bacteria and MgO and control....The upper and lower portions of Musa sapientum pseudo-stem sheaths were exposed in four types of treatments： pectin decomposing bacteria, magnesium oxide （MgO）, both pectin decomposing bacteria and MgO and control. The fibre strength properties were tested using SIRIM Standard methods and colour changed using gray scale. The bioaugmentation of pectin decomposing bacteria together with MgO additions were found to enhance retting process and reduced retting periods 52% and yielded better strength on the fibres. The lower portion pseudo-stem sheaths gave the higher strength than upper portion. Colour changed showed that the bioaugmentation of pectin bacteria enhanced the degradation colouring compound in banana fibres.展开更多
In this paper,a reinforced gradient-type iterative learning control pro file is proposed by making use of system matrices and a proper learning step to improve the tracking performance of batch processes disturbed by ...In this paper,a reinforced gradient-type iterative learning control pro file is proposed by making use of system matrices and a proper learning step to improve the tracking performance of batch processes disturbed by external Gaussian white noise.The robustness is analyzed and the range of the step is speci fied by means of statistical technique and matrix theory.Compared with the conventional one,the proposed algorithm is more ef ficient to resist external noise.Numerical simulations of an injection molding process illustrate that the proposed scheme is feasible and effective.展开更多
基金supported by the Division of Physical Science,Faculty of Science,Prince of Songkla University (PSU),Thailand
文摘This research investigated the combined effects of addition of Bi and Sb elements on the microstructure,thermal properties,ultimate tensile strength,ductility,and hardness of Sn−0.7Ag−0.5Cu(SAC0705)solder alloys.The results indicated that the addition of Bi and Sb significantly reduced the undercooling of solders,refined theβ-Sn phase and extended the eutectic areas of the solders.Moreover,the formation of SbSn and Bi phases in the solder matrix affected the mechanical properties of the solder.With the addition of 3 wt.%Bi and 3 wt.%Sb,the ultimate tensile strength and hardness of the SAC0705 base alloy increased from 31.26 MPa and 15.07 HV to 63.15 MPa and 23.68 HV,respectively.Ductility decreased due to grain boundary strengthening,solid solution strengthening,and precipitation strengthening effects,and the change in the fracture mechanism of the solder alloys.
文摘The upper and lower portions of Musa sapientum pseudo-stem sheaths were exposed in four types of treatments： pectin decomposing bacteria, magnesium oxide （MgO）, both pectin decomposing bacteria and MgO and control. The fibre strength properties were tested using SIRIM Standard methods and colour changed using gray scale. The bioaugmentation of pectin decomposing bacteria together with MgO additions were found to enhance retting process and reduced retting periods 52% and yielded better strength on the fibres. The lower portion pseudo-stem sheaths gave the higher strength than upper portion. Colour changed showed that the bioaugmentation of pectin bacteria enhanced the degradation colouring compound in banana fibres.
基金Supported by National Natural Science Foundation of China(F010114-6097414061273135)
文摘In this paper,a reinforced gradient-type iterative learning control pro file is proposed by making use of system matrices and a proper learning step to improve the tracking performance of batch processes disturbed by external Gaussian white noise.The robustness is analyzed and the range of the step is speci fied by means of statistical technique and matrix theory.Compared with the conventional one,the proposed algorithm is more ef ficient to resist external noise.Numerical simulations of an injection molding process illustrate that the proposed scheme is feasible and effective.
