Science — page 74 of 132

13,110 terms including subtopics (0 terms filed directly here)

Subtopics

Science terms

  1. Mast cell A type of white blood cell.
  2. 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…
  3. Mastic A soft sealing material.
  4. Materials recovery facility (MRF) (MRF) A recycling facility for municipal solid waste.
  5. maternal effect An effect attributable to a genetic contribution of the female parent of the individual being evaluated.
  6. Maternal gene product A product in the male organism of a gene from the X chromosome.
  7. maternal inheritance Inheritance controlled by non-nuclear genes (e.g. mitochrondria, chloroplast ) that are transmitted only through the female line.
  8. matric potential A water potential component, always of negative value, resulting from the presence of solid (often finely divided) surfaces; primarily responsible for…
  9. Matter-Dominated Universe When the density of matter is greater than that of any other component.
  10. maturation The formation of gametes or spores.
  11. Mauna Loa An intermittently active volcano (elevation: 13,680 feet; 4,170 meters) on the island of Hawaii.
  12. Maunder Minimum From 1645 to 1715, scientists believe there was a decrease in the total energy output from the Sun, as indicated by little or no sunspot activity.
  13. MAV AVN MOS Guidance
  14. MAX Maximum
  15. Max Parcel Level (MPL) This signifies the highest attainable level that a convective updraft can reach; therefore, it is a good indication of how tall a thunderstorm may reach.
  16. Maximum Contaminant Level (MCL) (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…
  17. Maximum Contaminant Level Goal (MCLG) The level of a contaminant in drinking water below which there is no known or expected risk to health.
  18. Maximum controllable water surface The highest reservoir water surface elevation at which gravity flows from the reservoir can be completely shut off.
  19. Maximum credible earthquake (MCE) The largest hypothetical earthquake that may be reasonably expected to occur along a given fault or other seismic source could produce under the current…
  20. Maximum demand The greatest of all demands of the load that has occurred within a specified period of time.
  21. Maximum design earthquake (MDE) The earthquake selected for design or evaluation of the structure. This earthquake would generate the most critical ground motions for evaluation of the…
  22. Maximum flood control level The highest elevation of the flood control storage.
  23. Maximum output See Nameplate capacity
  24. Maximum Spillway Discharge Spillway discharge (cfs) when reservoir is at maximum designed water surface elevation.
  25. Maximum Sustained Surface Wind When applied to a particular weather system, refers to the highest one-minute average wind (at an elevation of 10 meters with an unobstructed exposure)…
  26. Maximum Temperature This is the highest temperature recorded during a specified period of time. Common time periods include 6, 12 and 24 hours.
  27. Maximum Unambiguous Range The range from the radar at which an echo can be known unquestionably as being at that range.
  28. Maximum Unambiguous Velocity The highest radial velocity that can be measured unambiguously by a pulsed Doppler radar.
  29. Maximum unit weight The dry unit weight defined by the peak of a compaction curve. See unit weight.
  30. Maximum water surface (maximum pool) The highest acceptable water surface elevation with all factors affecting the safety of the structure considered.
  31. Maximum wave The highest wave in a wave group.
  32. MAXT High temperature for the day. Usually forecast out 7 days in advance.
  33. Mayan Long Count Calendar The basis for the doomsday predictions, which is a nonrepeating calendar with “baktun” cycles of about 400 years -- with the 13th ending, and the 14th…
  34. MB Millibar
  35. MBF One thousand board feet of lumber.
  36. MCC Mesoscale Convective Complex. A large MCS, generally round or oval-shaped, which normally reaches peak intensity at night.
  37. MCDB See moisture content, dry basis.
  38. MCF An abbreviation for one thousand cubic feet of natural gas with a heat content of 1,000,000 Btus, or 10 therms.
  39. MCL See Maximum contaminant level
  40. MCS Abbreviation for multiple cloning site. See: polylinker.
  41. MD Mesoscale Discussion- When conditions actually begin to shape up for severe weather, SPC (Storm Prediction Center) often issues a Mesoscale Discussion…
  42. MDA Abbreviation for multiple drop array. See: microdroplet array.
  43. MDFY Modify
  44. MDLS models
  45. MDNGT midnight
  46. MDT Moderate (or) Mountain Daylight Time
  47. 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.
  48. Mean annual increment The annual average growth rate for a tree, computed over its entire life cycle.
  49. Mean Annual Temperature The average temperature for the entire year at any given location.
  50. Mean Areal Precipitation (abbrev. MAP)- The average rainfall over a given area, generally expressed as an average depth over the area.
  51. Mean Daily Temperature The average of the highest and lowest temperatures during a 24-hour period.
  52. Mean Depth The average depth of water in a stream channel or conduit. It is equal to the cross-sectional area divided by the surface width.
  53. Mean Doppler Velocity Reflectivity-weighted average velocity of targets in a given pulse resolution volume. Usually determined from a large number of successive radar pulses.
  54. Mean Low Water (MLW) - A tidal datum. The average of all the low water heights observed over the National Tidal Datum Epoch.
  55. Mean Lower Low Water (MLLW) - A tidal datum. The average of the lower low water height of each tidal day observed over the National Tidal Datum Epoch.
  56. Mean number The average number.
  57. 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.
  58. Mean Sea Level (MSL) - The arithmetic mean of hourly water elevations observed over a specific 19-year tidal epoch.
  59. Mean sea level (MSL) (MSL) The arithmetic mean of hourly water elevations observed over a specific 19-year tidal epoch.
  60. Mean Wind Speed The arithmetic wind speed over a specified time period and height above the ground (the majority of U.S.
  61. Meander Big bend and loops in a river channel as the river snakes through a flat land area.
  62. Meander Belt The area between lines drawn tangential to the extreme limits of fully developed meanders.
  63. Measured Ceiling A ceiling classification applied when the ceiling value has been determined by an instrument, such as a ceilometer or ceiling light, or by the known…
  64. Mechanical Systems Those elements of building used to control the interior climate.
  65. Mechanism the means by which an effect or change is produced.
  66. Media Any organization in the business of informing the public with news or commentary.
  67. median A statistics term. The middle value in a set of measurements.
  68. 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.
  69. 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.
  70. Median Wind Speed The wind speed with 50 percent probability of occurring.
  71. medium (pl.: media) 1. In plant tissue culture, a term for the liquid or solid formulation upon which plant cells, tissues or organs develop.
  72. Medium Btu Gas Fuel gas with a heating value of between 200 and 300 Btu per cubic foot.
  73. medium formulation In tissue culture, the particular constituents for the culture medium, commonly comprising macro- and micro-elements, vitamins, plant hormones, and a…
  74. Medium Frequency (abbrev. MF)- That portion of the radio frequency spectrum from 0.3 to 3 MHz.
  75. Medium Pressure For valves and fittings, implies that they are suitable for working pressures between 125 to 175 pounds per square inch.
  76. Medium Range In forecasting, (generally) three to seven days in advance.
  77. Medium-height dam A dam between 100 and 300 feet high. See low dam and high dam.
  78. Medium-size water system A water system that serves greater than 3,300 and less than or equal to 50,000 persons.
  79. Medium-thick arch dam An arch dam with a base thickness to structural height ratio between 0.2 and 0.3 (previously defined as between 0.3 and 0.5).
  80. mega A prefix meaning "million".
  81. mega yeast artificial chromosome A yeast artificial chromosome (YAC) which can carry particularly large inserts (up to 1Mbp) - standard YACs typically carry inserts of up to 500kbp.
  82. megabase (Abbreviation: Mb). A length of DNA consisting of 106 bases.
  83. Megabase (Mb) Unit of length for DNA fragments equal to 1 million nucleotides and roughly equal to 1 cM. See also: centimorgan
  84. Megabase cloning The cloning of very large DNA fragments. (See Cloning.)
  85. megaDalton (Abbreviation: MDa). One megaDalton is equal to 106 Dalton.
  86. Megafauna A number of species of presently extinct mammals including mammoths and mastodons.
  87. megagametophyte The female gametophyte; the plant that develops from a megaspore.
  88. megaspore The female gametophyte in heterosporous plants. Synonym: macrospore.
  89. Megawatt One thousand kilowatts, or 1 million watts; standard measure of electric power plant generating capacity.
  90. Megawatt (MW) (MW) A measure of instantaneous electric power consumption or production. Equal to one thousand KW.
  91. Megawatt electrical (MWe) One million watts of electrical energy; a measure of electrical power capacity, use in PEIS is synonymous with MW.
  92. Megawatt-hour One thousand kilowatt-hours or 1 million watt-hours.
  93. Megawatt-hour (MWh) One million watt- hours of electrical energy.
  94. Megawatthour (MWh) (MWh) 1,000 kilowatt-hours or 1 million watt-hours.
  95. MEGG Merging
  96. Meiosis A special form of cell division in which each daughter cell receives half the amount of DNA as the parent cell.
  97. meiotic analysis The use of patterns of chromosome pairing at meiotic prophase and metaphase to detect relationships between chromosomes, from which can be deduced the…
  98. meiotic drive Any mechanism that causes a particular allele or chromosome to be over-represented in a population of gametes.
  99. meiotic product See: gamete.
  100. melanin (MEH-luh-nin) A pigment that gives color to skin and eyes and helps protect it from damage by ultraviolet light.