Science — page 2 of 132

Science terms

101. acetyl co-enzyme A (Abbreviation: acetyl CoA) A compound formed in the mitochondria when an acetyl group (CH3CO-) - derived from breakdown of fats, protein s, or…
102. acetyl CoA Abbreviation for acetyl co-enzyme A.
103. ACGIH American Conference of Government Industrial Hygienists.
104. ACHP Advisory Council on Historic Preservation.
105. ACID A solution that has an excess of hydrogen ions (H+).
106. Acid deposition A comprehensive term for the various ways acidic compounds precipitate from the atmosphere and deposit onto surfaces.
107. acid detergent fiber (ADF) (ADF) Organic matter that is not solubilized after one hour of refluxing in an acid detergent of cetyltrimethylammonium bromide in 1N sulfuric acid.
108. Acid hydrolysis A chemical process in which acid is used to convert cellulose or starch to sugar.
109. acid insoluble lignin Lignin is mostly insoluble in mineral acids, and therefore can be analyzed gravimetrically after hydrolyzing the cellulose and hemicellulose fractions of…
110. Acid Precipitation Precipitation, such as rain, snow or sleet, containing relatively high concentrations of acid-forming chemicals that have been released into the…
111. Acid Rain A term used to describe precipitation that has become acidic (low pH) due to the emission of sulfur oxides from fossil fuel burning power plants.
112. acid soluble lignin A small fraction of the lignin in a biomass sample is solubilized during the hydrolysis process of the acid insoluble lignin method.
113. Acid Solution Any water solution that has more hydrogen ions (H+) than hydroxide ions (OH-); any water solution with a pH less than 7. See basic solution.
114. Acidic The condition of water or soil which contains a sufficient amount of acid substances to lower the pH below 7.0.
115. Acidified The addition of an acid (usually nitric or sulfuric) to a sample to lower the pH below 2.0.
116. ACLD Above Cloud Level
117. ACP Abbreviation for acyl carrier protein.
118. ACPY Accompany
119. acquired Developed in response to the environment, not inherited, such as a character trait (acquired characteristic) resulting from environmental effect(s).
120. Acquired genetic mutation See: somatic cell genetic mutation
121. ACR alkali-carbonate reaction.
122. Acre (ac) Unit for measuring land, equal to 43,560 sq. ft., 4840 sq. yds., or 160 sq. rds.
123. Acre-foot One surface acre of water 1 foot deep or 43,560 cubic feet of water. The total acre-feet of water in a pond is determined by multiplying the number of…
124. Acre-foot (ac-ft) (ac-ft) A term used in measuring the volume or amount of water needed to cover 1 acre (43,560 square feet) 1 foot deep (325,851 gallons or 1,233.5 cubic meters).
125. acridine dyes A class of positively charged polycyclic molecules that intercalate into DNA and induce frameshift mutations.
126. ACRM Assistant Commissioner-Resources Management.
127. acrocentric A chromosome that has its centromere near the end.
128. acropetal Arising or developing in a longitudinal sequence beginning at the base and proceeding towards the apex. Opposite: basipetal.
129. ACRS Across
130. Action Stage The stage which, when reached by a rising stream, represents the level where the NWS or a partner/user needs to take some type of mitigation action in…
131. Activated carbon See activated charcoal.
132. activated charcoal Charcoal that has been treated to remove hydrocarbons and to increase its adsorptive properties.
133. Activated sludge process A biological wastewater treatment process in which a mixture of waste water and activated sludge is agitated and aerated.
134. Active (abbrev. ACTV). In solar-terrestrial terms, solar activity levels with at least one geophysical event or several larger radio events (10cm) per day (Class…
135. Active (Usable) Storage Capacity The total amount of reservoir capacity normally available for release from a reservoir below the maximum storage level.
136. Active capacity The reservoir capacity normally usable for storage and regulation of reservoir inflows to meet established reservoir operating requirements.
137. Active conservation capacity (active storage) The reservoir capacity assigned to regulate reservoir inflow for irrigation, power, municipal and industrial use, fish and wildlife, navigation…
138. Active Conservation Storage The portion of water stored in a reservoir that can be released for all useful purposes such as municipal water supply, power, irrigation, recreation…
139. Active Cooling The use of mechanical heat pipes or pumps to transport heat by circulating heat transfer fluids.
140. Active Dark Filament (ADF) In solar-terrestrial terms, an Active Prominence seen on the Disk.
141. Active earth pressure The minimum value of earth pressure. This condition exists when a soil mass is permitted to yield sufficiently to cause its internal shearing resistance…
142. Active fault A fault which, because of its present tectonic setting, can undergo movement from time to time in the immediate geologic future.
143. Active Longitude In solar-terrestrial terms, the approximate center of a range of heliographic longitudes in which Active Regions are more numerous and more flare-active…
144. Active Management Area (AMA) (AMA) Active Management Areas were established in Arizona to provide long-term management and conservation of limited groundwater supplies.
145. Active Power The power (in Watts) used by a device to produce useful work. Also called input power.
146. Active Prominence In solar-terrestrial terms, a prominence displaying material motion and changes in appearance over a few minutes of time.
147. Active Prominence Region (APR) In solar-terrestrial terms, a portion of the solar limb displaying active prominences.
148. Active Region (AR) In solar-terrestrial terms, a localized, transient volume of the solar atmosphere in which plages, sunspots, faculae, flares, etc. may be observed.
149. Active Solar Heater A solar water or space-heating system that use pumps or fans to circulate the fluid (water or heat-transfer fluid like diluted antifreeze) from the solar…
150. Active Storage Capacity In hydrologic terms, the total amount of reservoir capacity normally available for release from a reservoir below the maximum storage level.
151. Active Surge Region (ASR) In solar-terrestrial terms, an Active Region that exhibits a group or series of spike-like surges that rise above the limb.
152. Active traders Market participants who trade frequently, often many times a day, and therefore are attune to the ebbs and flows, the rumors, breaking news, activities of…
153. Active transport The movement of a molecule or groups of molecules across a cell membrane, which requires the expenditure of cellular energy, because the direction of…
154. Active volcano A volcano that is erupting. Also, a volcano that is not presently erupting, but that has erupted within an historical time and is considered likely to…
155. activity The number of transformations that take place each second in a given amount of radioactive material.
156. ACTS Action Correspondence Tracking System.
157. Actual cubic feet per minute (ACFM) (ACFM) The actual cubic feet per minute of gas flowing in a process at the temperature and pressure of the process at that point.
158. actual evapotranspiration The rate of water lost from vegetation and soil, ordinarily at a slower rate than the potential rate.
159. ACTV Active. In solar-terrestrial terms, solar activity levels with at least one geophysical event or several larger radio events (10cm) per day (Class M…
160. Acute (uh-KYOOT) Symptoms or signs that begin and worsen quickly; not chronic.
161. Acute exposure A single exposure to a toxic substance which results in severe biological harm or death.
162. Acute toxicity The ability of a substance to cause poisonous effects resulting in severe biological harm or death soon after a single exposure or dose.
163. acute transfection Short-term transfection.
164. ACWA Association of California Water Agencies.
165. ACYC Anticyclone - A large-scale circulation of winds around a central region of high atmospheric pressure, clockwise in the Northern Hemisphere…
166. acyl carrier protein (Abbreviation: ACP). A class of molecules that bind acyl intermediates during the formation of long-chain fatty acids.
167. Adaptation Adjustment of a population to changes in environment over generations, associated (at least in part) with genetic changes resulting from selection imposed…
168. ADAPTATION (ADAPTABLE) PARAMETER Generally, data related to a specific WSR-88D unit. These data may consist of meteorological or hydrological parameters or of geographic boundaries…
169. Adaptive management A continuing process of action-based planning, monitoring, researching, evaluating, and adjusting with the objective of improving implementation and…
170. Adaptive Management Area (AMA) (AMA) Landscape units designated for development and testing of technical and social approaches to achieving desired ecological, economic, and other social…
171. Adaptive radiation The evolution of new species or sub- species to fill unoccupied ecological niches.
172. ADAS Automated Data Acquisition System
173. Additive Data A group of coded remarks that includes pressure tendency, amount of precipitation, and maximum/minimum temperature during specified periods of time
174. Additive effect Combined effect of two or more chemicals equal to the sum of their individual effects.
175. additive genes Genes whose net effect is the sum of their individual allelic effects, i.e. they show neither dominance nor epistasis.
176. Additive genetic effects When the combined effects of alleles at different loci are equal to the sum of their individual effects. See also: anticipation, complex trait
177. additive genetic variance The net effect of the expresson of additive genes, and thus the chief cause of the resemblance between relatives.
178. ADDS Aviation Digital Data Service
179. adenine (Abbreviation: A). One the base s found in DNA and RNA. See: adenosine.
180. Adenine (A) A nitrogenous base, one member of the base pair AT (adenine-thymine). See also: base pair, nucleotide
181. adenosine The (ribo)nucleoside resulting from the combination of the base adenine (A) and the sugar D-ribose.
182. adenosine deaminase deficiency (ADA) A severe immunodeficiency disease that results from a lack of the enzyme adenosine deaminase.
183. adenosine diphosphate (adenosine 5'-diphosphate) (Abbreviation: ADP). See: adenosine triphosphate.
184. adenosine monophosphate (adenosine 5'-monophosphate) (Abbreviation: AMP). See: adenylic acid, adenosine triphosphate.
185. adenosine triphosphate (adenosine 5'-triphosphate) (Abbreviation: ATP). A nucleotide of fundamental importance as the major carrier of chemical energy in all living organisms.
186. adenovirus (A-den-oh-VY-rus) A group of viruses that cause respiratory tract and eye infections.
187. adenylic acid Synonym for adenosine monophosphate, a (ribo)nucleotide containing the nucleoside adenosine.
188. Adequate Public Facilities Adequate public facilities ordinances prevent new construction until municipal services, including water, sewer, roads, and schools, are available to…
189. Adequate Water Supply Program The Arizona Adequate Water Supply Program requires anyone who offers subdivided land outside of an Active Management Area for sale or lease to obtain a…
190. Adhesion The "stick" between two touching objects. Adhesion implies a static condition, while traction implies a moving condition.
191. ADI acceptable daily intake.
192. Adiabat A line on a thermodynamic chart relating the pressure and temperature of a substance (such as air) that is undergoing a transformation in which no heat is…
193. Adiabatic Without loss or gain of heat to a system. An adiabatic change is a change in volume and pressure of a parcel of gas without an exchange of heat between…
194. Adiabatic Lapse Rate The rate of decrease of temperature experienced by a parcel of air when it is lifted in the atmosphere under the restriction that it cannot exchange heat…
195. Adiabatic Process A process which occurs with no exchange of heat between a system and its environment.
196. Adipocyte Fat cell.
197. Adipose tissue A type of connective tissue that stores fat.
198. Adirondack Type Snow Sampling Set A snow sampler consisting of a 5-foot fiberglass tube, 3 inches in diameter, with a serrated-edge steel cutter at one end and a twisting handle at the…
199. Adit A nearly horizontal underground excavation in an abutment having an opening in only one end.
200. ADJ Adjacent