Previous research has shown that the temperature of underlying permafrost decreases after the ground surface is covered with sand. No significant conclusions have yet been drawn that explain why this happens, because the heat transfer mechanism effects of the sand layer on the underlying permafrost remain unclear. These mechanisms were studied in the present work. We found that the upward short...

In the evolution processes of wind blown sand movement and aeolian geomorphology, it always contains some complex behaviors, for example, the nonlinear character of turbulence and attractors, the stochastic character of wind gust, liftoff and movement of sand, the interaction among wind field, sand movement, electric field in wind blown sand flux and thermal diffusion, multi-scale character fro...

Straw checkerboard barrier (SCB) is the most representative antidesertification measure and plays a significant role in antidesertification projects. Large-eddy simulation and discrete-particle tracing were used to numerically simulate the wind sand movement inside the straw checkerboard barrier (SCB), study the movement characteristics of sand particles, find the transverse velocities of sand ...

We study the evolution of a one-dimensional pile, empty at rst, which receives a grain in its rst stack at each iteration. The nal position of grains is singular: grains are sorted according to their parity. They are sorted on trapezoidal areas alternating on both sides of a diagonal line of slope p 2. This is explained and proved by means of a local study. Each generated pile, encoded in heigh...

hirschsprung's disease, also known as congenital aganglionic megacolon, is a congenital disorder which develops due to an absence of neural ganglia in a segment of large bowel. most commonly, the rectum or rectosigmoid, and rarely other areas or the entire colon are involved. in this disease, all three neural plexi, i.e., the myenteric (auerbach's) plexus, the superficial submucosal (...