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Nodule (other)
Nodule may refer to: *Nodule (geology), a small rock or mineral cluster *Manganese nodule, a metallic concretion found on the seafloor *Nodule (medicine), a small aggregation of cells *Root nodule Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known a ..., a growth on the roots of legumes * A feature of mollusc sculpture {{disambig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nodule (geology)
In sedimentology and geology, a nodule is a small, irregularly rounded knot, mass, or lump of a mineral or mineral aggregate that typically has a contrasting composition, such as a pyrite nodule in coal, a chert nodule in limestone, or a phosphorite nodule in marine shale, from the enclosing sediment or sedimentary rock. Normally, a nodule has a warty or knobby surface and exists as a discrete mass within the host strata. In general, they lack any internal structure except for the preserved remnants of original bedding or fossils. Nodules are closely related to concretions and sometimes these terms are used interchangeably. Minerals that typically form nodules include calcite, chert, apatite (phosphorite), anhydrite, and pyrite.Neuendorf, KKE, JP Mehl, Jr., and JA Jackson, eds. (2005) ''Glossary of Geology'' (5th ed.). Alexandria, Virginia, American Geological Institute. 779 pp. Boggs S, Jr. (2009) ''Petrology of Sedimentary Rocks.'' Cambridge University Press, Cambridge, Unite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manganese Nodule
Polymetallic nodules, also called manganese nodules, are mineral concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core. As nodules can be found in vast quantities, and contain valuable metals, deposits have been identified as a potential economic interest. Nodules vary in size from tiny particles visible only under a microscope to large pellets more than across. However, most nodules are between in diameter, about the size of hen's eggs or potatoes. Their surface textures vary from smooth to rough. They frequently have botryoidal (mammillated or knobby) texture and vary from spherical in shape to typically oblate (flying saucer), sometimes prolate (Rugby ball), or are otherwise irregular. The bottom surface, buried in sediment, is generally rougher than the top due to a different type of growth. Occurrence Nodules lie on the seabed sediment, often partly or completely buried. They vary greatly in abundance, in some cases ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nodule (medicine)
In medicine, nodules are small firm lumps, usually greater than 1 cm in diameter. If filled with fluid they are referred to as cysts. Smaller (less than 0.5 cm) raised soft tissue bumps may be termed papules. The evaluation of a skin nodule includes a description of its appearance, its location, how it feels to touch and any associated symptoms which may give clues to an underlying medical condition. Nodules in skin include dermatofibroma and pyogenic granuloma. Nodules may form on tendons and muscles in response to injury, and are frequently found on vocal cords. They may occur in organs such as the lung, or thyroid, or be a sign in other medical conditions such as rheumatoid arthritis. Characteristics Nodules are small firm lumps usually greater than 1 cm in diameter, found in skin and other organs. If filled with fluid they are usually softer and referred to as cysts. Smaller (less than 0.5 cm) raised soft tissue bumps may be termed papules. Evaluation The evaluation of a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Root Nodule
Root nodules are found on the roots of plants, primarily legumes, that form a symbiosis with nitrogen-fixing bacteria. Under nitrogen-limiting conditions, capable plants form a symbiotic relationship with a host-specific strain of bacteria known as rhizobia. This process has evolved multiple times within the legumes, as well as in other species found within the Rosid clade. Legume crops include beans, peas, and soybeans. Within legume root nodules, nitrogen gas (N2) from the atmosphere is converted into ammonia (NH3), which is then assimilated into amino acids (the building blocks of proteins), nucleotides (the building blocks of DNA and RNA as well as the important energy molecule ATP), and other cellular constituents such as vitamins, flavones, and hormones. Their ability to fix gaseous nitrogen makes legumes an ideal agricultural organism as their requirement for nitrogen fertilizer is reduced. Indeed, high nitrogen content blocks nodule development as there is no benefit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
