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.
(Redirected from Brown alga). The Phaeophyceae or brown algae (singular: alga), is a large group of mostly marine multicellular algae, including many seaweeds of colder Northern Hemisphere waters.They play an important role in marine environments, both as food and for the habitats they form.rowth in most brown algae occurs at the tips of structures as a result of divisions in a single apical cell or in a row of such cells. As this apical cell divides, the new cells that it produces develop into all the tissues of the alga.