Experiences from the international frontlines: An exploration of the perceptions of airport employees during the COVID-19 pandemic

The aviation industry is one of the sectors that has been heavily impacted by the pandemic. While the major body of literature has focused on passenger experience and behaviour, this study focuses on airport employees instead—their experiences, perceptions, and preferences following the emergence of COVID-19. More than 1000 participants from...

Erosion Behavior of Sand-Silt Mixtures: Revisiting the Erosion Threshold

The erosion threshold, beyond which bed sediments start to move, is a key parameter describing sediment transport processes. For silt-dominated mixtures, in which the grain size is between sand and clay, existing experimental studies exhibit contradictory observations. That is, the erosion was either sand-like or clay-like, suggesting...

Seismic Slip-Pulse Experiments Simulate Induced Earthquake Rupture in the Groningen Gas Field

Rock materials show dramatic dynamic weakening in large-displacement (m), high-velocity (∼1 m/s) friction experiments, providing a mechanism for the generation of large, natural earthquakes. However, whether such weakening occurs during induced M3-4 earthquakes (dm displacements) is unknown. We performed rotary-shear experiments on simulated...

Microphysical Model Predictions of Fault Restrengthening Under Room-Humidity and Hydrothermal Conditions: From Logarithmic to Power-Law Healing

The maximum fault strength and rate of interseismic fault strengthening (“healing”) are of great interest to earthquake hazard assessment studies, as they directly relate to event magnitude and recurrence time. Previous laboratory studies have revealed two distinct frictional healing behaviors, referred to as Dieterich-type and non-Dieterich...

Non-Repeatability, Scale- and Model Effects in Laboratory Measurement of Impact Loads Induced by an Overtopped Bore on a Dike Mounted Wall

Overtopping bore impact forces on a dike mounted vertical wall were measured in similar large-scale (Froude length scale factor 1-to-4.3) and small-scale (Froude length scale factor 1-to-25) models. The differences due to scale effects were studied, by comparing the up-scaled force measurements from both models in prototype. It was noted that if...

Deriving vegetation drag coefficients in combined wave-current flows by calibration and direct measurement methods

Coastal vegetation is efficient in damping incident waves even in storm events, thus providing valuable protections to coastal communities. However, large uncertainties lie in determining vegetation drag coefficients (C_D), which are directly related to the wave damping capacity of a certain vegetated area. One major uncertainty is...

Effects of task complexity and time pressure on activity-travel choices: Heteroscedastic logit model and activity-travel simulator experiment

This paper derives, estimates and applies a discrete choice model of activity-travel behaviour that accommodates potential effects of task complexity and time pressure on decision-making. To the best of our knowledge, this is the first time that both factors (task complexity and time pressure) are jointly captured in a discrete choice model....

Task Complexity and Time Pressure: Impacts on Activity-Travel Choices

Task complexity and time pressure may have impacts on travellers’ choices in the context of highly synchronised mobility networks. However, it is unclear at the moment how these two aspects should be properly modelled simultaneously and what these impacts of the two aspects really are on travellers’ choices. Consequently, this research aims to...

Wave reduction by S-Catamaran at supercritical speeds