A Quantitative Exploration of Continuous Vaccination of the COVID-19 Vaccine: an Empirical Study From China

Background: Vaccination for the novel coronavirus disease 2019 (COVID-19) provides an effective approach for the general improvement of social safety and individual health. However, to date, few studies have analyzed the continuous vaccination for COVID-19 vaccine and its impact process. This research explores factors that theoretically affect the public’s continuous vaccination for COVID-19 vaccine at every stage and constructs a theoretical model to analyze the entire impact process of continuous vaccination based on the Health Action Process Approach (HAPA) Model, the Expectation Confirmation Model (ECM) and the vaccine hesitancy (VH) theory.Methods: The respondents in this study were individuals in China who have been vaccinated. In addition, structural equation modeling technology was used to analyze the influence of factors on the continuous vaccination for COVID-19 vaccine and the whole impact process.Results: First, perceived efficacy has a positive significant impact on vaccination intention, but the positive effects of outcome expectancy and risk perception on vaccination intention are not significant. Second, social positive cues have a positive significant influence on vaccination intention. Third, VH has a negative significant influence on vaccination intention. Four, vaccination behavior produces a positive significant effect on perceived usefulness and satisfaction, respectively. Five, perceived usefulness exerted a positive significant impact on satisfaction and continuous vaccination, respectively. Six, satisfaction has no positive significant influence on continuous vaccination.Conclusions: Our theoretical model, which is the main contribution of this research, indicates that individual continuous vaccination is a process from motivation to intention, and from intention to behavior, and then from behavior to continuous behavior.

A Numerical Study of Rockslide-Structure Interactions in a Dip Slope Disaster by 3D Discrete Element Modeling

<p>The past decade has witnessed increasing case studies on the application of 3D discrete element modeling to assess potential rockslide disasters. The assessment is usually based only on the influence area related to kinematic process and final deposition by the simulation. Currently, the hazard of the rockslide-structure interaction is not well defined, and only a few studies have quantality this behavior with a parametric analysis. A dip slope disaster case history on 18 August 1997 in Taiwan was simulated in this study using discrete element method (DEM). The landslide intensely damaged a five-floor building complex of the Lincoln community and caused 28 death. This study first gathered historical aerial images, geology maps of 1:50,000 scale, post-disaster investigation reports, and in-situ photos to clarify the geological and geometry conditions of the dip slope and its spatial relationship to the Lincoln community. Most importantly, a 3D geomechanical model was developed for the numerical study. With the advantage of DEM analysis on large deformation problems, the entire impact process of the dip slope failure was simulated, starting from rock mass sliding to collision and breaking during movement, impacting on the structural buildings and progressive failure of the structures. The simulated results agree well with the field observation after the incident in 1997. The parametric results show that the configuration of the geological discontinuity dominates the magnitude of the potential sliding block, and the rockslide-structure interactions are affected by the relative location between rock slope and buildings and the strengths of rock mass and structure elements. Overall, the 3D DEM-based simulation provides qualitative information on the impact process of the rockslide and the damage states of the building complex. This validated numerical approach can be a valuable tool for assessing the building vulnerability to rockslide with scenario study.</p>

A numerical analysis of compressive residual stresses in cold gas dynamic spray (CGDS) deposition method

This study presents a finite element approach of a numerical model to investigate the profile of the deformed sprayed particles and the compressive residual stresses analysis at the interfacial zone of particle and substrate impact using cold gas dynamic spray (CGDS). The Lagrangian approach was used to analyze, in details, the material deformation behavior during impact, contact problems of single-particle impact process and the outputs of equivalent plastic strain and temperature to achieve a qualitative understanding of cold gas dynamic spray contact process of cold sprayed particle on the substrate. The evolution of residual compressive stresses during impact was also analyzed for multiple-particles impact process using the Lagrangian approach. It can be observed that the compressive residual stresses increase by increasing the preheating temperature and particle initial impact velocity.