Can virtual tourism aid in the recovery of tourism industry in the COVID-19 pandemic?

The COVID-19 pandemic has imposed tremendous impacts on the tourism industry worldwide. The tourism sector can take advantage of the new technology (e.g., virtual tourism), to respond to the challenges. This study aims to explore how virtual tourism can aid the recovery of tourism industry. We explore this through a mixed-method approach. Our results show that the use of virtual tourism can be partially explained by the theory of planned behavior. Virtual tourism has a strong influence on people’s onsite destination choices and can be used as an effective marketing tool. Virtual tourism can be an entertainment activity to bring immersed experience without being actually in the destinations, and thus reinforce stay-at-home order. Even after the pandemic is over, people still show willingness to use virtual tourism for diverse purposes. Virtual tourism can also help promote sustainable tourism by reducing unnecessary greenhouse gas emissions and enhance “virtual accessibility” especially for the elderly and disabled with limited mobility

The νR\nu_{R}-philic scalar dark matter

Right-handed neutrinos ($\nu_{R}$) offer an intriguing portal to new physics in hidden sectors where dark matter (DM) may reside. In this work, we delve into the simplest hidden sector involving only a real scalar exclusively coupled to $\nu_{R}$, referred to as the $\nu_{R}$-philic scalar. We investigate the viability of the $\nu_{R}$-philic scalar to serve as a DM candidate, under the constraint that the coupling of $\nu_{R}$ to the standard model is determined by the seesaw relation and is responsible for the observed DM abundance. By analyzing the DM decay channels and solving Boltzmann equations, we identify the viable parameter space. In particular, our study reveals a lower bound ($\sim10^{4}$ GeV) on the mass of $\nu_{R}$ for the $\nu_{R}$-philic scalar to be DM. The DM mass may vary from sub-keV to sub-GeV. Within the viable parameter space, monochromatic neutrino lines from DM decay can be an important signal for DM indirect detection.Comment: 21 pages, 5 figure

Improved micro-continuum approach for capillary-dominated multiphase flow with reduced spurious velocity

A diverse range of multiphase flow and transport occurs in multiscale porous media. The multiphase micro-continuum Darcy-Brinkmann-Stokes (DBS) model has been developed to simulate the multiphase flow at both the pore and continuum scales via single-field equations. However, the unacceptable spurious velocities produced by the conventional micro-continuum DBS model present challenges to the modeling of capillary-dominated flow dynamics. This study improves the micro-continuum DBS model to mitigate these spurious velocities at the gas-liquid interface and contact-line regions. A hybrid interpolation scheme is proposed to improve the computational accuracy of the interface curvature and reduce the spurious velocity around the gas-liquid interface by 1-2 orders of magnitude. At the porous boundary, the normal to the gas-liquid interface is corrected, and the normal to the solid-fluid interface is smoothed to guarantee the prescribed wettability condition and decrease the spurious velocities at the contact-line region by an order of magnitude. A series of static and dynamic benchmark cases are investigated to demonstrate that the improved DBS model can simulate capillary-dominated multiphase flows with negligible spurious velocities at capillary numbers as low as 10-4 in both simple and complex geometries. The improved DBS model can combine X-ray computed micro-tomography images to perform multiscale simulations of capillary-dominated multiphase flow and understand the effect of sub-resolution porosity on fluid dynamics in naturally multiscale rocks