Energy terms starting with M

155 terms

Maar A volcanic crater that is produced by an explosion in an area of low relief, is generally more or less circular, and often contains a lake, pond, or marsh.
Macrophyte (aquatic) An aquatic plant that is large enough to be observed with the naked eye. It grows in or near water.
Mafic (or maphic) A term used to describe an igneous rock that has a large percentage of dark-colored minerals such as amphibole, pyroxene, and olivine.
Magma Molten or partially molten rock at temperatures ranging from 1,260 F to 2,880 F (700 C to 1600 C).
Magnetic Ballast A type of florescent light ballast that uses a magnetic core to regulate the voltage of a florescent lamp.
Maintenance area Any geographic region of the United States previously designated nonattainment pursuant to the CAA Amendments of 1990 and subsequently redesignated to…
Major source A source that emits, or has the potential to emit, a pollutant regulated under the Clean Air Act in excess of a specified rate in a nonattainment area.
Make-Up Air Air brought into a building from outside to replace exhaust air.
Mammals A group of air-breathing animals whose skin is more or less covered with hair or fur and who have mammary glands.
Management activities Planned activities initiated by land managers to meet the desired future condition for an area.
Management area Management areas are specific geographical areas defined by a forest plan. Each management area has a set of objectives and a management prescription…
Management indicator species Species selected as ecological indicators. The welfare of a management indicator species is presumed to be an indicator of the welfare of other species…
Management plan A plan guiding overall management of an area administered by a federal or state agency.
mannan The polymer of mannose with a repeating unit of C6H10O5. Can be hydrolyzed to mannose. (Source: Voet, D.; Voet, J. G. Biochemistry.
mannose A hexose component of many polysaccharides, occasionally used as a carbohydrate source in plant tissue culture media.
Mano A stone with a flat side that was primarily held in one's hand or hands and used to grind edible substances, typically corn, grains, and nut meats.
Mantle The main bulk of the Earth, between the crust and core, ranging from depths of about 40 to 3,480 kilometers.
Mantle hot spot A region of continental or oceanic crust below which a mantle plume causes melting of the overlying crust, resulting in a broad regional topographic swell…
Manual J The standard method for calculating residential cooling loads developed by the Air-Conditioning and Refrigeration Institute (ARI) and the Air Conditioning…
Margin requirement The margin requirement is the minimum amount the Federal Reserve, in Regulation T, requires you to deposit in a margin account before you can trade…
Marginal Cost The cost of producing one additional unit of a product.
Marginal electric generating unit In organized wholesale markets, the price of the marginal source of electricity usually sets the price of the unit providing the next increment or…
Mark-to-market Adjustment of the book value or collateral value of a security – including a security such as a multiyear contract – to reflect current market value…
Market Traditionally, a securities market was a place - such as the New York Stock Exchange (NYSE) - where members met to buy and sell securities.
Market capitalization Value of a corporation as determined by the market price of its issued and outstanding securities.
Market concentration A measure, usually an estimate, of the market share of a participant or groups of participant in the overall market or a submarket (a given region…
Market liquidity The ease, or lack thereof, with which a buyer can buy or a seller can sell at a prevailing price in a marketplace.
Market participant A market buyer or a market seller, or both, that meets reasonable creditworthiness standards established by the market operator.
Market power The ability of any market participant with a large market share to significantly control or affect price by withholding production from the market…
Market structure The rules, mechanisms and processes, under which a market operates to form prices, provide benefits and introduce risks to participants, and ultimately…
Marsh An area of low-lying wetlands dominated by grasslike plants.
mash A mixture of grain and other ingredients with water to prepare wort for brewing operations.
Masonry Material such as brick, rock, or stone.
Masonry Stove A type of heating appliance similar to a fireplace, but much more efficient and clean burning.
Mass Burn Facility A type of municipal solid waste (MSW) incineration facility in which MSW is burned with only minor presorting to remove oversize, hazardous, or explosive…
mass closure (%) The percent by weight of the total samples extracted from the biomass sample compared to the weight of the original sample.
Massachusetts Sustainable Design Roundtable Created by the Executive Office of Energy and Environmental Affairs and the Division of Capital Asset Management the Roundtable explores ways in which the…
MassGIS The Commonwealth's Office of Geographic and Environmental Information, within the Massachusetts Executive Office of Energy and Environmental Affairs…
Master Plan The term has two meanings: 1) a permit type issued to large residential or commercial buildings that sets a building-wide standard for future changes that…
Materials recovery facility (MRF) A recycling facility for municipal solid waste.
Maximum Contaminant Level (MCL) The highest level of a contaminant that is allowed in drinking water. MCLs ensure that drinking water does not pose either a short-term or long-term…
Maximum output See Nameplate capacity
MBF One thousand board feet of lumber.
MCDB See moisture content, dry basis.
MCF An abbreviation for one thousand cubic feet of natural gas with a heat content of 1,000,000 Btus, or 10 therms.
MCL See Maximum contaminant level
Mean A statistics term. The average value in a set of measurements. The mean is the sum of a set of numbers divided by how many numbers are in the set.
Mean annual increment The annual average growth rate for a tree, computed over its entire life cycle.
Mean Power Output (of a Wind Turbine) The average power output of a wind energy conversion system at a given mean wind speed based on a Raleigh frequency distribution.
Mean sea level (MSL) The arithmetic mean of hourly water elevations observed over a specific 19-year tidal epoch.
Mean Wind Speed The arithmetic wind speed over a specified time period and height above the ground (the majority of U.S.
Mechanical Systems Those elements of building used to control the interior climate.
Median household income Divides households into two equal segments, with one-half of households earning less than the median household income and the other half earning more.
Median housing value Divides housing units into two equal segments, one-half of housing units less than median housing value and the other half valued more.
Median Wind Speed The wind speed with 50 percent probability of occurring.
Medium Btu Gas Fuel gas with a heating value of between 200 and 300 Btu per cubic foot.
Medium Pressure For valves and fittings, implies that they are suitable for working pressures between 125 to 175 pounds per square inch.
Megafauna A number of species of presently extinct mammals including mammoths and mastodons.
Megawatt One thousand kilowatts, or 1 million watts; standard measure of electric power plant generating capacity.
Megawatt (MW) A measure of instantaneous electric power consumption or production. Equal to one thousand KW.
Megawatt electrical (MWe) One million watts of electrical energy; a measure of electrical power capacity, use in PEIS is synonymous with MW.
Megawatt-hour One thousand kilowatt-hours or 1 million watt-hours.
Megawatthour (MWh) 1,000 kilowatt-hours or 1 million watt-hours.
Merchant generator A generating plant built with no energy sales contracts in place.
Merchantable Logs from which at least of the volume can be converted into sound grades of lumber ("standard and better" framing lumber).
Mercury Vapor Lamp A high-intensity discharge lamp that uses mercury as the primary light-producing element. Includes clear, phosphor coated, and self-ballasted lamps.
Mesa A broad, flat-topped elevation with one or more steeply-sloping to vertical sides.
Mesic habitat A habitat type characterized by the presence of a moderate amount of moisture or water. Compare: hydric; opposite: xeric.
Mesophilic An optimum temperature for bacterial growth in an enclosed digester (25° to 40°C).
Mesozoic An era of geologic time between the Paleozoic and the Cenozoic, spanning the time between 251 and 65 million years ago.
MET An approximate unit of heat produced by a resting person, equal to about 18.5 Btu per square foot per hour.
metabolism (meh-TA-boh-lih-zum) The total of all chemical changes that take place in a cell or an organism.
Metal Halide Lamp A high-intensity discharge lamp type that uses mercury and several halide additives as light-producing elements.
Metamorphic rock A sedimentary or igneous rock that has been changed by pressure, heat, or chemical action.
Metate A portable stone slab upon which seeds and other grains are milled with a mano using a push-pull, back-and-forth motion. See also Mano
Methane A colorless, odorless, tasteless gas composed of one molecule of Carbon and four of hydrogen, which is highly flammable.
Methanogen A methane-producing organism.
Methanol Methyl alcohol having the chemical formula CH30H. Methanol is usually produced by chemical conversion at high temperatures and pressures. Wood alcohol.
Methanol (CH<sub>3</sub>OH; Methyl alcohol or wood alcohol) A clear, colorless, very mobile liquid that is flammable and poisonous; used as a fuel and fuel additive, and to produce chemicals.
methanol (wood alcohol) (CH3OH) An alcohol formed by catalytically combining carbon monoxide with hydrogen in a 1:2 ratio under high temperature and pressure.
Methyl tertiary butyl ether (MTBE) An ether manufactured by reacting methanol and isobutylene. MTBE has high octane and low volatility. Used as a fuel oxygenate.
Metric Ton (or tonne) 1000 kilograms. 1 metric ton = 2,204.62 lb = 1.023 short tons.
Metric Ton (Tonne) A unit of mass equal to 1,000 kilograms or 2,204.6 pounds.
mg/l Milligrams per liter.
MGD Million gallons per day.
Microalgae Unicellular, photosynthetic aquatic plants.
Microbiotic soil crusts See Biological soil crusts
Microclimate The local climate of specific place or habitat, as influenced by landscape features.
Microgroove A small groove scribed into the surface of a solar photovoltaic cell which is filled with metal for contacts.
Micrometer One millionth of a meter (10-6 m).
Micron One thousandth of a millimeter.
microorganism An organism that can be seen only through a microscope. Microorganisms include bacteria, protozoa, algae, and fungi.
Microphytic soil crusts See Biological soil crusts
Microsite A small area within an environment with unique features, conditions, or characteristics relative to the surrounding area.
Mid seral species Shade intolerant species, primarily Douglas-fir trees and vine maple shrubs. These species typically follow the early seral species in natural succession.
Mid seral treatment A treatment in which a stand of predominately mid seral species will be established.
Migration corridor A route followed by animals such as big game, birds, or fish when traveling between winter and summer habitats.
Migratory Bird Treaty Act (MBTA) The MBTA implements various treaties and conventions between the United States, and Canada, Japan, Mexico, and the former Soviet Union for the protection…
Military Training Route (MTR) A designated corridor of airspace with defined vertical and lateral dimensions established for conducting military flight training at airspeeds in excess…
Mill A common monetary measure equal to one-thousandth of a dollar or a tenth of a cent.