Aeolian ripples arise instantaneously from sandy beds subjected to winds sufficient to cause saltation to surface grains. It is now widely believed that the process of ripple formation is a self-organizing phenomenon involving non-linear dynamics in the variation of flux of secondary grains that are ejected through saltation. In addition, the metric entropy and interaction matrix of the system ...

Wind resuspension (or entrainment) provides a source of dust and contaminants for the atmosphere. Conventional wind erosion models parameterize dust resuspension flux with a threshold velocity or with a horizontal abrasion flux; in the absence of abrasion the models assume dust flux is transient only. Our experiments with an uncrusted, fine material at relative humidities exceeding 40% show a l...

Here we address the old question in aeolian particle transport about the role of midair collisions. We find that, surprisingly, these collisions do enhance the overall flux substantially. The effect depends strongly on restitution coefficient and wind speed. We can explain this observation as a consequence of a soft bed of grains which floats above the ground and reflects the highest flying par...

Introduction The volumetric transport rate of sand, or flux, is a fundamental parameter that controls the rate of landscape modification. This process is responsible for the movement of ripples and dunes, as well as the abrasion of rocks and landforms. Measuring sand flux on Mars was previously not possible because of the lack of high spatial and temporal resolution images, and appropriate tech...

The purpose of this study is to summarize current terminology related unconventional warfare. Based on extensive research, and the experience gained over past decades, paper proposes a synthesized definition that consistent with philosophy reinterpreting contemporary military conflicts. War, as part human nature (N. Machiavelli) social phenomenon has been marked by constant development strategi...