An oligotroph is an organism that can live in an environment that offers very low levels of nutrients. They may be contrasted with copiotrophs, which prefer nutritionally rich environments. Oligotrophs are characterized by slow growth, low rates of metabolism, and generally low population density. Oligotrophic environments are those that offer little to sustain life. These environments include deep oceanic sediments, caves,
Permeability in fluid mechanics and the Earth sciences (commonly symbolized as k) is a measure of the ability of a porous material (often, a rock or an unconsolidated material) to allow fluids to pass through it. Symbol used to represent in situ permeability tests in geotechnical drawings Contents 1Permeability 2Units 3Applications 4Description 4.1Relation to hydraulic conductivity 4.2Anisotropic permeability 5Determination 5.1Permeability model based on conduit flow 6Absolute
Plastic pollution is the accumulation of plastic objects and particles (e.g. plastic bottles, bags and microbeads) in the Earth’s environment that adversely affects humans, wildlife and their habitat. Plastics that act as pollutants are categorized by size into micro-, meso-, or macro debris. Plastics are inexpensive and durable, making them very adaptable for different uses; as a result, manufacturers choose to
Plastics are a wide range of synthetic or semi-synthetic materials that use polymers as a main ingredient. Their plasticity makes it possible for plastics to be moulded, extruded or pressed into solid objects of various shapes. This adaptability, plus a wide range of other properties, such as being lightweight, durable, flexible, and inexpensive to produce, has led to its widespread use. Plastics typically are made through human
Plecoptera is an order of insects, commonly known as stoneflies. Some 3,500 species are described worldwide, with new species still being discovered. Stoneflies are found worldwide, except Antarctica. Stoneflies are believed to be one of the most primitive groups of Neoptera, with close relatives identified from the Carboniferous and Lower Permian geological periods, while true stoneflies are known from fossils only a bit younger. Their modern diversity,
A plunge pool (or plunge basin or waterfall lake) is a deep depression in a stream bed at the base of a waterfall or shut-in. It is created by the erosional forces of cascading water on the rocks at formation’s base where the water impacts. The term may refer to the water occupying the depression, or the depression itself. Contents 1Formation 2See also 3References 4External
The ocean (also the sea or the world ocean) is the body of salt water that covers approximately 70.8% of the surface of Earth and contains 97% of Earth’s water. An ocean can also refer to any of the large bodies of water into which the world ocean is conventionally divided. Separate names are used to identify five different areas of the ocean: Pacific (the largest), Atlantic, Indian, Southern (Antarctic), and Arctic (the smallest). Seawater covers approximately
Ol’ Man River is a show tune from the 1927 musical Show Boat with music by Jerome Kern and lyrics by Oscar Hammerstein II. The song contrasts the struggles and hardships of African Americans with the endless, uncaring flow of the Mississippi River. It is sung from the point of view of a black stevedore on a showboat, and is the most famous song from the show. The song is
Northumberland (/nɔːrˈθʌmbərlənd/) is a county in Northern England, one of two counties in England which border with Scotland. Notable landmarks in the county include Alnwick Castle, Bamburgh Castle, Hadrian’s Wall and Hexham Abbey. It is bordered by land on three sides; by the Scottish Borders region to the north, County Durham and Tyne and Wear to the south, and Cumbria to the west. The fourth side is the North Sea, with a 103-kilometre (64 mi)
The Nerodime (Albanian: Nerodimja or Nerodime; Serbian Cyrillic: Неродимка) is a river in the Nerodime region of Kosovo, a 41 km-long left tributary to the Lepenc river. It represents Europe’s only instance of a river bifurcation flowing into two seas, dividing into two irreversible branches. The left branch flows into the Black Sea, and the right branch flows into the Aegean Sea. For other cases see List of unusual drainage