Mineral Leasing Act of 1920 (MLA)(MLA)Authorizes the agency to issue rights-of-way grants for oil and gas gathering and distribution pipelines and related facilities not already authorized…
Mineral materialsWidespread deposits of common clay, sand, gravel, or stone which are not subject to disposal under the 1872 Mining Law, as amended.
mineralizationThe conversion of organic compounds into inorganic (mineral) ones. For example, the conversion of ethanol into carbon dioxide and water.
Miners' InchA rate of discharge through an orifice one inch square under a specific head.
mini-prepA small-scale preparation of plasmid or phage DNA. Used to purify cloned DNA from the DNA of the vector.
MinigeneratorA trademark of Union Carbide Corporation that is used to identify radioisotope generator systems for educational use.
Minimal tillage practicesPractices that allow farmers to reduce the tilling of the land to conserve topsoil and its nutrients.
Minimum Discernible SignalIn a receiver, it is the smallest input signal that will a produce a detectable signal at the output.
minimum effective cell densityThe cell density below which reproducible cell growth fails. The minimum density is determined by both the source function of the tissue (species…
Minimum flowNegotiated lowest flow in a regulated stream that will sustain an aquatic population of agreed-upon levels. Flow may vary seasonally.
minimum inoculum sizeThe critical volume of inoculum required to initiate culture growth, due to the diffusive loss of cell materials into the medium.
Minimum operating levelThe lowest level to which the reservoir is drawn down under normal operating conditions.
Minimum TemperatureThis is the lowest temperature recorded during a specified period of time. The time period can be 6, 12 or 24 hours.
MiningUsually removal of soil or rock having value because of its chemical composition.
Mining claimThat portion of the public mineral lands which a miner, for mining purposes, takes and holds in accordance with the mining laws.
Mining water useWater use during quarrying rocks and extracting minerals from the land.
minisatelliteA form of variable number tandem repeats in which the repeat unit size ranges from 10-100 bp. Used for DNA fingerprinting following Southern hybridization.
minituberSmall tubers (5-15 mm in diameter) formed on shoot cultures or cuttings of tuber-forming crops, such as potato.
Minor FloodingA general term indicating minimal or no property damage but possibly some public inconvenience.
Minor Tidal OverflowMinor flooding caused by high tides that results in little if any damage.
Minority CarrierA current carrier, either an electron or a hole, that is in the minority in a specific layer of a semiconductor material; the diffusion of minority…
Minority populationIncludes Hispanic, American Indian, or Alaskan Native; Asian; Native Hawaiian or Other Pacific Islander; Black (not of Hispanic origin) or African…
MioceneAn epoch of the upper Tertiary period, 23 to 5.3 million years ago.
MirrorA reflecting surface of various physical shapes (parabolic, nearly flat, or flat) used to reflect and/or concentrate the sun's energy to specific…
mismatchThe occurrence of a non-complementary pairs of bases in a double helix of DNA, e.g. A:C, G:T.
mismatch repairA DNA repair process that corrects mismatched base pairs.
MisoscaleThe scale of meteorological phenomena that ranges in size from 40 meters to about 4 kilometers. It includes rotation within a thunderstorm.
missense mutationA mutation that changes a codon for one amino acid into a codon specifying another amino acid.
Mission of the Hydrologic Services ProgramTo provide river and flood forecasts and warnings for the protection of life and property and to provide basic hydrologic forecast information for the…
Mission of the National Weather ServiceTo provide weather and flood warnings, public forecasts and advisories for all of the United States, its territories, adjacent waters and ocean areas…
MISTA visible aggregate of minute water particles suspended in the atmosphere that reduces visibility to less than 7 statute miles, but greater than or equal…
mist propagationApplication of fine droplets of water to maintain humidity around plantlets or cuttings, which have not yet developed effective roots.
miteFree-living and parasitic arachnids. Infestation of plant crops reduces yield through the destruction of leaf tissue.
MitigationTerm usually used to refer to various changes or improvements made in a home; for instance, to reduce the average level of radon.
Mitigation (measures)Methods or actions that will reduce adverse impacts from solar facility development.
Mitochondria(MY-toh-KON-dree-uh) Small structures in a cell that are found in the cytoplasm (fluid that surrounds the cell nucleus).
Mitochondrial DNA(Abbreviation: mtDNA). A circular DNA found in mitochondria. In mammals, mtDNA makes up less than 1% of the total DNA, but in plants the amount is…
mitochondrion(pl.: mitochondria) Organelle possessing its own DNA which appear in all eukaryotic cells (and never in prokaryotic cells) and produce adenosine…
mitogenA substance that can cause cells to initiate mitosis.
Mitosis(my-TOH-sis) The process by which a single parent cell divides to make two new daughter cells.
mixed budA bud containing both rudimentary leaves and flowers.
Mixed faceIn tunneling, digging in dirt and rock in the same heading at the same time.
Mixed LayerAn atmospheric layer, usually the layer immediately above the ground, in which pollutants are well mixed by convective or shear-produced turbulence.
Mixed PrecipitationAny of the following combinations of freezing and frozen precipitation: snow and sleet, snow and freezing rain, or sleet alone. Rain may also be present.
Mixed Use DevelopmentDevelopment that is created in response to patterns of separate uses that are typical in suburban areas necessitating reliance on cars.
Mixing DepthVertical distance between the ground and the altitude to which pollutants are mixed by turbulence caused by convective currents or vertical shear in the…
Mixing HeightsThe height to which a parcel of air, or a column of smoke, will rise, mix or disperse. A column of smoke will remain trapped below this height.
Mixing RatioThe ratio of the weight of water vapor in a specified volume (such as an air parcel) to the weight of dry air in that same volume.
Mixing ValveA valve operated by a thermostat that can be installed in solar water heating systems to mix cold water with water from the collector loop to maintain a…
mixoploidGroups of cells with variable (a mix of euploid, aneuploid, polyploid ) chromosome numbers.
MJOMadden-Julian Oscillation- Tropical rainfall exhibits strong variability on time scales shorter than the seasonal El Niño-Southern Oscillation (ENSO).
MLCAPEMean Layer CAPE - CAPE calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb above ground level.
MLLIMean Layer Lifted Index - Lifted Index (LI) calculated using a parcel consisting of Mean Layer values of temperature and moisture from the lowest 100 mb…
MLLW(Mean Lower Low Water) - A tidal datum. The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch.
MLW(Mean Low Water) - A tidal datum. The average of all the low water heights observed over the National Tidal Datum Epoch.
Mobile FacilityThe ARM Mobile Facility (AMF) was first deployed in 2005; it consists of large shipping containers converted into laboratories.
mobilization1. The transfer between bacteria of a non-conjugative plasmid by a conjugative plasmid. 2.
mobilizing functionThe genes on a plasmid that give it the ability to facilitate the transfer of either a non-conjugative or a conjugative plasmid from one bacterium to…
MOBYMarine Optical Buoy. It measures solar radiation to calibrate satellite ocean color instruments.
Modal SplitA term that describes how many people use alternative forms of transportation. Frequently used to describe the percentage of people using private…
modeIn a frequency distribution, the class having the greatest frequency.
Model organismsA laboratory animal or other organism useful for research.
Model Output Statistics(abbrev. MOS) - the Hydrometeorological Center (HPC) produces a short range (6 to 60 hours) MOS (Model Output Statistics) guidance package generated from…
Model yearRefers to the "sales" model year; for example, vehicles sold during the period from October 1 to the next September 31 is considered one model year.
ModelingThe use of statistical analysis, computer analysis, or model organisms to predict outcomes of research.
Moderate FloodingThe inundation of secondary roads; transfer to higher elevation necessary to save property -- some evacuation may be required.
Moderate frequency floodA flood of lesser magnitude than the IDF, used for the service spillway design when supplemented by a separate auxiliary spillway.
modern biotechnologyThe application of: a. In vitro nucleic acid techniques, including recombinant deoxyribonucleic acid (DNA ) and direct injection of nucleic acid into…
ModificationAny change to the terms of a mortgage loan, including changes to the interest rate, loan balance, or loan term.
Modification Decision Analysis (MDA)The process of determining with confidence whether dam safety deficiencies exist for maximum loading conditions.
Modified Degree-Day MethodA method used to estimate building heating loads by assuming that heat loss and gain is proportional to the equivalent heat-loss coefficient for the…
Modified homogeneous earthfill damA homogeneous earthfill dam that uses pervious material specially placed in the embankment to control seepage. See embankment dam.
Modified Mercalli scaleAn earthquake intensity scale which has twelve divisions ranging from I (not felt by people) to XII (nearly total damage).
modifying geneA gene that affects the expression of some other gene.
moduleThe smallest self-contained, environmentally protected structure housing interconnected photovoltaic cells and providing a single dc electrical output…
MOETAbbreviation for multiple ovulation and embryo transfer.
Mohr circleA graphical representation of the stresses acting on the various planes at a given point.
Moist AdiabatThe line on a Skew T-Log P chart that depicts the change in temperature of saturated air as it rises and undergoes cooling due to adiabatic expansion.
Moist Adiabatic Lapse Rate(abbrev. MALR)- The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere.
moist adiabatic lapse rate (MALR)(MALR)The rate at which the temperature of a parcel of saturated air decreases as the parcel is lifted in the atmosphere.
Moist-adiabatic(Also known as saturation-adiabatic process.) An adiabatic process for which the air is saturated and may contain liquid water.
MoistureThe amount of water and other components present in the biomass sample that are volatilized at 105°C. (Source: Ehrman, T.
Moisture ContentThe water content of a substance (a solid fuel) as measured under specified conditions being the: Dry Basis, which equals the weight of the wet sample…
Moisture Content (MC)(MC)The weight of the water contained in wood, usually expressed as a percentage of weight, either oven-dry or as received.
Moisture content (water content)The ratio of the weight of water in a soil sample to the weight of the dry soil, expressed as a percentage. See optimum moisture content.
Moisture content, dry basis (MCDB)(MCDB)Moisture content expressed as a percentage of the weight of oven-dry wood. weight of wet sample - weight of dry sample…
Moisture content, wet basis (MCWB)(MCWB)Moisture content expressed as a percentage of the weight of wood as-received. Expressed as: weight of wet sample - weight of dry sample…