A novel solvent emulsification-displacement method for obtaining polystyrene nanoparticles is reported. This process has an added value and can be an alternative for the recycling of expanded polystyrene.
The higher order discontinuous asymptotic fields which are similar to the Williams’ solutions of homogenous material are obtained by the displacement method and asymptotic analysis for a plane crack at the physical weak-discontinuous interface in non-homogeneous materials. The results provide a theoretical basis for the numerical analysis, experimental investigation and the engineering application of physical weak-discontinuous fracture.
This paper presents the dynamic analytical solution of a piezoelectric stack utilized in an actuator and a generator based on the linear piezo-elasticity theory. The solutions for two different kinds of piezoelectric stacks under external load were obtained using the displacement method. The effects of load frequency and load amplitude on the dynamic characteristics of the stacks were discussed. The analytical solutions were validated using the available experimental results in special cases. The proposed model is able not only to predict the output properties of the devices, but also to reflect the inner electrical and mechanical components, which is helpful for designing piezoelectric actuators and generators in a comprehensive manner.
Statically indeterminate frame, composed of beams and columns, is a widely used structure form in civil engineering. The frame carrying capacity under various actions is related to the absolute stiffness of frame components and relative beam-column line stiffness ratio. The matrix displacement method and programming based on MATLAB were employed in this study to calculate the internal forces and displacements of a 2-bay 2-story frame structure under the action of horizontal loads. The influence of the beam-column line stiffness ratio on the frame load capacity was discussed based on the calculated result. Furthermore some advises were provided about the reasonable beam-column line stiffness ratio for engineering design.
Implementation of the emulsification-diffusion method by solvent displacement for polystyrene nanoparticles prepared from recycled material