U-u

Threshold. Minimum value of the intensity of a stimulus from which the response occurs.
Environmental unit: Homogeneous unit both in its physical characteristics and in its behavior or response to certain actions or stimuli.
Conservation unit: Equivalent to a protected natural area.
Dobson unit. Unit of measurement for the thickness of the ozonosphere or ozone layer. Abreviatura Db.
Uranium. chemical element of group VIII of the periodic table, actinide family. Atomic number 92 and atomic mass 238.03. It is a very dense metal, bright white and soft. The U 238 decays with a half-life of 4.500 millions of years. It is found in nature combined in minerals such as uranite and pitchblende.. It has applications in the nuclear industry. U symbol.
Multiple use: Use of a common set of resources for the simultaneous production of a number of goods and services, minimizing damage to basic resources and other environmental factors.
Sustainable use: Use of natural resources through minimal alteration of ecosystems and maintaining maximum biodiversity. It is the way to take advantage of them in such a way that they do not run out and serve to continue producing sustainably in perpetuity.. The main premise to respect is that the extraction of products is not greater than the rate of their natural replacement. (replacement rate).