Causes. Dry skin (xerosis) often has an environmental cause. Certain diseases also can significantly affect your skin. Potential causes of dry skin include: Weather. Skin tends to be driest in winter, when temperatures and humidity levels plummet. But the season may not matter as much if you live in desert regions. Heat.
Brownian movement. n. The random movement of microscopic particles suspended in a liquid or gas, caused by collisions with molecules of the surrounding medium.Also called Brownian motion, molecular movement, pedesis.he random movement of microscopic particles suspended in a liquid or gas, caused by collisions with molecules of the surrounding medium.
In a solution or gas that has an area of high numbers of particles and an area of lower numbers of particles, the particles will diffuse, or move, from the area of higher to the area of lower concentration. This is known as simple diffusion, or passive diffusion.Simple diffusion does not require energy.Instead, it happens by random motion. Random motion is defined as movement that occurs by chance because there is no order or regular system by which the movements of the particles shift in a solution or gas.his is known as simple diffusion, or passive diffusion. Simple diffusion does not require energy. Instead, it happens by random motion. Random motion is defined as movement that occurs by chance because there is no order or regular system by which the movements of the particles shift in a solution or gas.