Search results
Results from the WOW.Com Content Network
In physics, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average, weighted by mole-fraction abundance figures) of these isotopes is the atomic weight listed for the element in the periodic table. The abundance of an isotope varies from ...
In ecology, local abundance is the relative representation of a species in a particular ecosystem. [1] It is usually measured as the number of individuals found per sample . The ratio of abundance of one species to one or multiple other species living in an ecosystem is referred to as relative species abundances . [ 1 ]
Relative species abundance is a component of biodiversity and is a measure of how common or rare a species is relative to other species in a defined location or community. [1] Relative abundance is the percent composition of an organism of a particular kind relative to the total number of organisms in the area.
The Mean Species Abundance Index (MSA) calculates the trend in population size of a cross section of the species. It does this in line with the CBD 2010 indicator for species abundance. [10] The Biodiversity Intactness Index (BII) measures biodiversity change using abundance data on plants, fungi and animals worldwide.
X-axis: The abundance rank. The most abundant species is given rank 1, the second most abundant is 2 and so on. Y-axis: The relative abundance. Usually measured on a log scale, this is a measure of a species abundance (e.g., the number of individuals) relative to the abundance of other species.
A diversity index is a method of measuring how many different types (e.g. species) there are in a dataset (e.g. a community).Diversity indices are statistical representations of different aspects of biodiversity (e.g. richness, evenness, and dominance), which are useful simplifications for comparing different communities or sites.
Potassium-40 is the largest source of natural radioactivity in animals including humans. A 70 kg human body contains about 140 g of potassium, hence about 140g × 0.0117% ≈ 16.4 mg of 40 K; [ 7 ] whose decay produces about 3850 [ 8 ] to 4300 disintegrations per second ( becquerel ) continuously throughout the life of an adult person (and ...
The difference is whether the relative abundance is with respect to all the nitrogen, i.e. 14 N plus 15 N, or just to 14 N. Since the atmosphere is 99.6337% 14 N and 0.3663% 15 N, a is 0.003663 in the former case and 0.003663/0.996337 = 0.003676 in the latter.