magma is molten rock that is found beneath the surface of the Earth. Geologically magma is a complex high-temperature silicate containing fluid substance, containing suspended crystals and gas bubbles. Magma, as liquid, preferentially forms in high temperature, low pressure environments within several kilometers of the Earth's surface. It has variable density, temperature and viscosity. Magma often collects in a magma chamber inside a volcano. When magma cools and solidifies beneath the Earth's surface, it forms what are known as intrusive igneous rocks. When it reaches the Earth's surface, it flows out as lava and forms (volcanic) rocks. Magma compositions may evolve after formation by fractional crystallization, contamination, and magma mixing. Fractional crystallization is one of the most important geochemical and physical processes operating within the Earth's crust and mantle. Fractional crystallization in silicate melts (magmas) is a very complex process compared to chemical systems in the laboratory because it is affected by a wide variety of phenomena. Prime amongst these is the composition, temperature and pressure of a magma during its cooling. According to the SiO2 composition the magma types are as follows: 1) Ultramafic (picric) SiO2 < 45%; 2) Mafic (basaltic) SiO2 < 50%; 3) Intermediate (andesitic) SiO2 ~ 60%; 4) Felsic (rhyolitic) SiO2 > 70%. Viscosity is a key melt property in understanding the behaviour of magmas. More silica-rich melts are more viscous. Dissolution of water drastically reduces melt viscosity. Higher-temperature melts are less viscous. More mafic magmas, such as those that form basalt, are hotter and less viscous than more silica-rich magmas, such as those that form rhyolite. Low viscosity leads to gentler, less explosive eruptions. Solidification of magma results igneous rock. In terms of modes of occurrence, iigneous rocks can be either intrusive (plutonic igneous rocks), extrusive (volcanic) or hypabyssal (subvolcanic).
in tropical and subtropical latitudes, mangrove forests occur along sandy and silty coasts. Mangroves are trees with odd roots, some of which curve upward like snorkels to attain oxygen lacking in the mud, and some of which curve downward, serving as silts to support the tree in changing water levels. Fish, shelfish, crabs, snakes, and other organisms thrive among the root network, and bird feed and nest in the foliage of these coastal forests. Mangroves protect coastlines; studies after the 2004 South Asian tsunami indicated that coasts with intact mangrove forests suffered less damage than deforested coasts.
see Earth mantle
The information required regarding manufacture and use of a substance is defined in Annex VI, 3, of REACH. It includes:
- Estimated total quantity manufactured, used in articles (subject to registration), and/or imported in tonnes/year (per registrant) in the calendar year of registration;
- Brief description of the process used in manufacture or production of articles (where relevant);
- Tonnage used for registrant’s own use;
- Form (substance, preparation or article) and/or physical state in which the substance is provided to downstream users, including,
- Concentration (range) in preparations;
- Quantities in articles;
- General description of identified uses;
- Information on waste quantities and composition form manufacture, use in articles and other identified uses.
- Uses advised against.
a map is a visual representation of an area, a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes. Most commonly used to depict geography, maps may represent any space, real or imagined, without regard to context or scale; e.g. space mapping, body mapping, brain mapping, DNA mapping, etc.
Many maps are static two-dimensional, geometrically accurate (or approximately accurate) representations of three-dimensional space, while others are dynamic or interactive, even three-dimensional.
Maps of the world or large areas are often either "political" or "physical". The most important purpose of the political map is to show territorial borders; the purpose of the physical is to show features of geography such as mountains, soil type or land use. Geological maps show not only the physical surface, but characteristics of the underlying rock, fault lines, and subsurface structures.
You can read more on: http://en.wikipedia.org/wiki/Map
You can find maps on the following website: http://www.sitesatlas.com/Maps/index.htm
heavy residual oil also called mazout, bunker C, bunker C fuel oil, or bunker oil used earlier for heating in industry. Typical soil contaminant. Earlier it was usually stored in soil basins. In winter it solidified and for dilution before pumping, transferring organic solvents and or diesel oil or fuil oil were used. These hydrocarbons applied as solvents contributed to the spreading of mazout in the environment. Not easily biodegradable, but the light components can be biodegraded using proper technology. Highly toxic due to high PAH content. The unbiodegraded neutral, non-dissolving residue can be stabilized in the soil. It can cause decreased eggs production and hatchability as well as reduced viability of birds (e.g. Japanese quails).
Medium Chain Chlorinated Paraffin
in the interests of clarity and rationality, the relevant EU Directives should be codified by assembling them in a single text.
The essential aim of any rules governing the production, distribution and use of medicinal products must be to safeguard public health. However, this objective must be attained by means which will not hinder the development of the pharmaceutical industry or trade in medicinal products within the Community.
mega-sites are large scale contaminated sites, which pose a large potential or an actual risk of deterioration to groundwater, sediment, soil and surface-water quality. These expensive sites such as mine sites and asbestos sites, require complicated and costly remediation. They are extremely complicated cleanups that are resource intensive, have different sources, and can take years to remediate. (Source: EUGRIS)
the process of two consecutive cell divisions in the diploid progenitors of sex cells. Meiosis results in four rather than two daughter cells, each with a haploid set of chromosomes.
also known as quicksilver or hydrargyrum watery or runny. Mercury is a chemical element with the symbol Hg and atomic number 80. Mercury is the only metal that is liquid at standard conditions for temperature and pressure. its freezing point is −38.83 °C, boiling point 356.73 °C.
Mercury occurs in deposits throughout the world mostly as cinnabar mercuric sulfide, which is the source of the red pigment vermilion, and is mostly obtained by reduction from cinnabar. Cinnabar is highly toxic by ingestion or inhalation of the dust. Mercury poisoning can also result from exposure to soluble forms of mercury such as mercuric chloride or methylmercury, inhalation of mercury vapor, or eating seafood contaminated with mercury.
Mercury is used in thermometers, barometers, manometers, sphygmomanometers, float valves, some electrical switches, and other scientific apparatus, though concerns about the element's toxicity have led to mercury thermometers and sphygmomanometers being largely phased out in clinical environments in favor of alcohol-filled, digital, or thermistor-based instruments. It remains in use in a number of other ways in scientific and scientific research applications, and in amalgam material for dental restoration. It is used in lighting: electricity passed through mercury vapor in a phosphor tube produces short-wave ultraviolet light which then causes the phosphor to fluoresce, making visible light.
Mercury in the environment is easily methylated by microorganisms. Methyl-mercury is highly toxic and volatile.
Fish and shellfish have a natural tendency to concentrate mercury in their bodies, often in the form of methylmercury. Species of fish that are high on the food chain, such as shark, swordfish, king mackerel, albacore tuna, and tilefish contain higher concentrations of mercury than others. As mercury and methylmercury are fat soluble, they primarily accumulate in the viscera, although they are also found throughout the muscle tissue. When this fish is consumed by a predator, the mercury level is accumulated. Since fish are less efficient at depurating than accumulating methylmercury, fish-tissue concentrations increase over time. Thus species that are high on the food chain amass body burdens of mercury that can be ten times higher than the species they consume. This process is called biomagnification. Mercury poisoning happened this way in Minamata, Japan, now called Minamata disease. High fish consumption, mainly the consumption of predator-fishes, poses high risk to human.
It has low mobility and bioavailability under reductive conditions, such as in wetlands and bed-sediments of surface waters.
The metamorphic rock is the result of the transformation of an existing rock type in a process called metamorphism, which means "change in form". The metamorphic rock is any rock derived from pre-existing rocks by mineralogical, chemical, and/or structural changes, essentially in the solid state, in response to marked changes in temperature, pressure, shearing stress, and chemical environment .The metamorphic rocks can be derived from sedimentary, igneous or another older metamorphic rock after having been subjected to heat and pressure (temperatures greater than 150 to 200 °C and pressures of 1500 bars) causing profound physical and/or chemical change. Metamorphic rocks make up a large part of the Earth's crust and are classified and named by texture, by chemical and mineral assemblage and by the characteristics of the preexisting rock. The mineral compositition of the metamorphic rocks depends on the composition of the preexisting rock, according to which the metamorphic rocks are grouped as: ultramafic, mafic, pellitic (clayee), carbonate bearing, quartz and quartz-feldspar containing rocks. Most metamorphic rocks are named based on their texture and structural features, and their mineralogy. The first step in naming a metamorphic rock is to always identify whether the rock is foliated or non-foliated. Among the foliated textures, metamorphic rocks are further classified based on how the minerals within the parent rock are affected by the changes in temperature and pressure. In general terms, increases in temperature and pressure result in different, more complex textures, and different foliated metamorphic rocks: foliated (slate, phyllite, schist, gneiss) and non-foliated. Non-foliated metamorphic rocks are usually named exclusively on the basis of mineral composition (hornfels, amphibolite, quartite). A close examination of the non-foliated rock will reveal the dominant one or two minerals within the rock. In some cases one may choose some prefix-type modifiers to attach to names to stress some important or unusual textural or mineralogical aspects. For example an “ortho”- prefix indicates an igneous parent, and a “para”- prefix indicates a sedimentary parent (orthogneiss, paragneiss). Metamorphic rocks are characterised by typical mineral assemblages according to the preexisting rock and the intensity of metamorphism. The intensity of metamorphism and the relevant metamorphic rocks are shown below:
- Very low intensity metamorphism (shale, metabasalt). Typical minerals: clay minerals, laumontite (zeolit), prehnite (zeolit).
- Low intensity metamorphism (serpentinite, chlorite shale, sericite shale). Typical minerals: sericit, pyrophyllite, chlorite.
- Medium intensity metamorphism (mica schist, marble). Typical minerals: mica, quartz, plagioclase, garnite, andalusite.
- High intensity metamorphism (eclogite, gneiss). Typical minerals: quartz, muscovite, biotite, plagioclase, kaliumfeldspar, sillimanite, staurolite.
in the geological terminology metamorphism means solid state changes in sedimentary, igneous and even metamorphic rocks. It takes place within the crust and in response to the agents of metamorphism: heat, pressure, chemically active fluids. The types of metamorphism are: 1. dynamic metamorphism that occurs along faults zones in response to pressure; 2. contact metamorphism resulting alteration of rocks at or near the contact of a cooling pluton; regional metamorphism occuring over a very large area in response to increased temperature and pressure.
metre or meter (m) is the base unit of length in the International System of Units (SI). Originally intended to be one ten-millionth of the distance from the Earth's equator to the North Pole, its definition has been periodically refined to reflect growing knowledge of metrology. Since 1983, it is defined as the distance travelled by light in a complete vacuum in 1⁄299,792,458 of a second.
Conversion of metre to other length units:
|meters||feet||3.280 839 895|
|meters||statute miles||0.000 621 371|
|meters||yards||1.093 613 298|
|meters, cubic||bushels||28.377 59|
|meters, cubic||cubic feet||35.314 666 7|
|meters, cubic||cubic inches||61,023.744|
|meters, cubic||cubic yards||1.307 950 619|
|meters, cubic||gallons||264.172 05|
|meters, cubic||pecks||113.510 4|
|meters, square||acres||0.000 247 105 38|
|meters, square||hectares||0.000 1|
|meters, square||square centimeters||10,000|
|meters, square||square feet||10.763 910 4|
|meters, square||square inches||1,550.003 1|
|meters, square||square yards||1.195 990 046|
colorless, odorless gas with a wide distribution in nature. Chemical formula: CH4. It is the principal component of natural gas, a mixture containing about 75% CH4, 15% ethane (C2H6), and 5% other hydrocarbons, such as propane (C3H8) and butane (C4H10). The "firedamp" of coal mines is chiefly methane. anaerobic bacterial decomposition of plant and animal matter, such as occurs under water, produces marsh gas, which is also methane. At room temperature, methane is a gas less dense than air. It melts at -183°C and boils at -164°C. It is not very soluble in water. methane is combustible, and mixtures of about 5 to 15 percent in air are explosive. methane is not toxic when inhaled, but it can produce suffocation by reducing the concentration of oxygen inhaled.
methyl tert-butyl ether, also known as methyl tertiary butyl ether and MTBE, is a chemical compound with molecular formula C5H12O. MTBE is a volatile, flammable and colorless liquid that is immiscible with water. MTBE is a gasoline additive (1-2%), used as an oxygenate to reduce carbon monoxide emission and to raise the octane number. MTBE quickly evaporates from open containers and surface water, so it is commonly found as a vapor in the air. It is much more soluble in water (5-7%) than the hydrocarbons. It has been found to easily pollute large quantities of groundwater e.g. around gas stations. MTBE may stick to particles in water, which will cause it to eventually settle to the bottom sediment. MTBE may be broken down quickly in the air by sunlight. It does not accumulates significantly in plants and animals. Breathing small amounts of MTBE for short periods may cause nose and throat irritation. Some people exposed to MTBE while pumping gasoline, driving their cars, or working in gas stations may have headaches, nausea, dizziness, and mental confusion. There is no evidence that MTBE causes cancer in humans. The EPA has issued guidelines recommending that drinking water levels of MTBE not exceed 3 mg/L. The American Conference of Governmental Industrial Hygienists (ACGIH) has recommended an exposure limit of 40 parts of MTBE per million parts of air (40 ppm) for an 8-hour workday, 40-hour workweek. (Source: Agency for Toxic Substances and Deseas Registry, ATSDR, www.atsdr.cdc.gov).
microbially induced corrosion
microbial corrosion, also called microbially induced corrosion (MIC) is corrosion caused or promoted by microorganisms, usually chemoautotroph bacteria. It can apply to both metals and non-metallic materials.
alternatíve respiration of microorganisms under low or negative redoxpotential. The chlorine of the organochlorine compounds is used as an electron-acceptor during the respiration of the anaerobic soil microorganisms. The product of the chlorine-respiration is HCl, hydrochloric acid.
microbicides are chemical substances whose purpose is to kill microbes (such as bacteria, fungi or protozoa) or reduce their activity.
Microbocides can be antibiotics, bactericides, fungicides.
Antibiotics are antimicrobial compounds, used to treat infections caused by microorganisms, including bacteria, fungi and protozoa. It kills, or inhibits the growth of the microbes.
In the natural environment antibiotics are produced by microorganisms which are antagonistic to the growth of other microorganisms. This natural inhibitory effect of antibiotics is copied by the synthetic antibiotics.
A bactericide is a substance that kills bacteria and, ideally, nothing else. Bactericides are either disinfectants, antiseptics or antibiotics.
Fungicides are chemical compounds or biological organisms used to kill or inhibit fungi or fungal spores. Fungicides are used both in agriculture and to fight fungal infections in animals and human.
microbiology is the study of microorganisms, which are unicellular or cell-cluster microscopic organisms. This includes eukaryotes such as fungi and protists, and prokaryotes. Viruses, though not strictly classed as living organisms, are also studied by microbiology. Microbiology refers to the study of life and organisms that are too small to be seen with the naked eye.
Microbiology typically includes the study of the immune system, or Immunology. Generally, immune systems interact with pathogenic microbes; these two disciplines often intersect which is why many colleges offer a paired degree such as "Microbiology and Immunology".
Microbiology is a broad term which includes virology, mycology, parasitology, bacteriology and other branches. A microbiologist is a specialist in microbiology and these other topics.
Microbiology is researched actively, and the field is advancing continually. It is estimated only about one percent of all of the microbe species on Earth have been studied. Although microbes were directly observed over three hundred years ago, the field of microbiology can be said to be in its infancy relative to older biological disciplines such as zoology and botany.
microinjection is a technique for introducing a solution of DNA into a cell using a fine microcapillary pipet.
basic unit of length, one millionth meter: 1 micrometre = 0, 000,001 metre.
The symbol of micrometre is μm.
It is also called micron.