We consider the finite-time blow-up of solutions for the following two kinds of nonlinear wave equation in de Sitter spacetime:This proof is based on a new blow-up criterion, which generalizes that by Sideris. Furthermore, we give the lifespan estimate of solutions for the problems.
The stress and strain on the surfaces of a rolling bearing has an important significance in bearing lifespan estimate, fault analysis, and stiffness calculation. Aimed at the contact problem of a deep groove ball bearing based on ANSYS, this paper mainly discusses three technologies, viz., parameterized modeling technology, division technology, and meshing technology, to provide a new method for setting the contact parameters in the process of finite-element analysis. The result shows that the method proposed in this paper is practicable, only with a small error relative to the Hertzian theory.
<p class="MsoNormal" style="text-align: justify; margin: 0in 0.5in 0pt;"><span style="font-size: 10pt;"><span style="font-family: Times New Roman;">Older individuals are generally assumed to be less risk tolerant compared to others. The purpose of this research was to test how accurately working adults at different ages in the lifespan estimate their risk-taking propensity. Differential predictions, using ANOVA and regression analyses, were assessed. Findings suggest that younger working adults tend to over-estimate their risk tolerance compared to older working adults. Although those in middle-age were shown to under-estimate their risk tolerance compared to the youngest working adults, the results were not significant. A discussion of findings is presented with the proposition that over- and under-estimation of risk tolerance might help explain the types of risk-taking behaviors engaged in by individuals over time. </span></span></p>
Blow-up and lifespan estimate for the generalized Tricomi equation with mixed nonlinearities