Science terms starting with V

227 terms

viable Capable of normal completion of life cycle.
Vibrating screen A screen which is vibrated to separate and move pieces resting on it.
vibrio Comma-shaped bacterium.
View duration Length of time a proposed action is in view. Impacts that are viewed for a long period of time are generally judged to be more severe than those viewed…
Viewer distance The distance from a viewpoint to a seen object or landscape element.
Viewpoint A point from which a landscape view is analyzed and/or evaluated.
Viewshed The total landscape seen or potentially seen from all or a logical part of a travel route, use area, or water body.
VIL Vertically-Integrated Liquid water. A property computed by RADAP II and WSR-88D units that takes into account the three-dimensional reflectivity of an…
Villi Projections from the surface, especially of a mucous membrane. If the projection is minute, as in a cell surface, it is called a microvillus.
Vimentin The major polypeptide that joins with other subunits to form the intermediate filament cytoskeleton of mesenchymal cells.
VIP this is another name for a high roller and stands for a Very Important Person.
vir genes A set of genes on a Ti plasmid that prepare the T-DNA segment for transfer into a plant cell.
viral coat protein A protein present in the layer surrounding the nucleic acid core of a virus.
Viral oncogene A viral gene that contributes to malig- nancies in vertebrate hosts. (See Oncogene.)
viral pathogen A disease-causing virus.
viral vaccine Vaccine consisting of live viruses, genetically engineered to avoid causing the disease itself.
Virga Streaks or wisps of precipitation falling from a cloud but evaporating before reaching the ground.
Virgin compression Compression corresponding to stresses greater than the preconsolidation stress.
Virgin compression curve The portion of the compression curve corresponding to virgin compression.
Virgin compression line Straight line approximating the virgin compression curve.
virion A complete infectious virus particle.
Viroid A plant pathogen that consists of a naked RNA molecule of approximately 250-350 nucleotides, whose extensive base pairing results in a nearly correct…
Virtual bidding In two-settlement electricity markets, financial transactions that allow participants to hedge against the risk that real-time and day-ahead prices will…
Virtual Potential Temperature The virtual potential temperature is the temperature a parcel at a specific pressure level and virtual temperature would have if it were lowered or raised…
Virtual Temperature The virtual temperature is the temperature a parcel which contains no moisture would have to equal the density of a parcel at a specific temperature and…
virulence The ability of a microorganism to cause damage to its host.
virulent phage A phage that destroys its host bacterium.
viruliferous A vector (usually insect) organism that carries virions and spreads the virus from host to host by mechanical means.
Virus (VY-rus) In medicine, a very simple microorganism that infects cells and may cause disease.
virus-free Plant, animal, cell, tissue or meristem which exhibits no viral symptoms or contains no identifiable virus particles.
virus-tested Description of a organism or a cell stock certified as being free of certain specified virus es following recognized procedures of virus diagnosis.
VIS 1. Visible satellite imagery 2. Visibile or Visibility
Viscosity The resistance of a fluid to flow. A liquid with a high viscosity rating will resist flow more readily than will a liquid with a low viscosity.
Visibility The distance at which a given standard object can be seen and identified with the unaided eye
Visibility factors Conditions or other phenomena that affect the visibility or appearance of an object or a landscape.
Visibility Protection Program The program specified by the Clean Air Act to achieve a national goal of remedying existing impairments to visibility and preventing future visibility…
Visible Light Electromagnetic radiation from about 400 to 700 nm, which is detectable by the human eye.
Visible Light Transmittance The amount of visible light that passes through the glazing material of a window, expressed as a percentage.
Visible Mass Mass that gives off electromagnetic radiation, so that it can be detected. It is ordinary (baryonic) matter.
Visible Radiation The visible portion of the electromagnetic spectrum with wavelengths from 0.4 to 0.76 microns
Visible Satellite Imagery This type of satellite imagery uses reflected sunlight (this is actually reflected solar radiation) to see things in the atmosphere and on the Earth's…
Visible Universe The part of the entire universe from which light would have had time to reach us in the age of the universe.
Visitor day Twelve visitor hours which may be aggregated by one or more persons in single or multiple visits.
Visitor use Visitor use of recreation and wilderness resource for inspiration, stimulation, solitude, relaxation, education, pleasure, or satisfaction.
Visual absorption capability The physical capacity of a landscape to accept human alterations without loss of its inherent visual character or scenic quality.
Visual attention Noticing and focusing of vision on a particular object or landscape element.
Visual clutter The complex visual interplay of numerous disharmonious landscape characteristics and features resulting in a displeasing view.
Visual contrast Opposition or unlikeness of different forms, lines, colors, or textures in a landscape.
Visual disharmony A state of disagreement, incongruity, or disproportionate arrangement of forms, lines, colors, and textures in the visual elements of a seen landscape.
Visual feature An element, such as a land or water form, vegetation, or structure in the seen landscape.
Visual harmony A pleasing array of visual elements in a landscape, usually as a result of a sense of visual order, compatibility, and completeness between and among the…
Visual impact Any modification in land forms, water bodies, or vegetation, or any introduction of structures, which negatively or positively affect the visual character…
Visual intrusion Any human-caused change in the land form, water form, vegetation, or the addition of a structure which creates a visual contrast in the basic elements…
Visual mitigation Actions taken to avoid, eliminate, or reduce potential adverse impacts on scenic resources.
Visual quality See Scenic quality
Visual Resource Inventory (VRI) Consists of a scenic quality evaluation, sensitivity level analysis, and a delineation of distance zones.
Visual Resource Inventory (VRI) Classes VRI Classes are assigned to public lands based upon the results from the Visual Resource Inventory.
Visual Resource Management (VRM) Class Designations Class I objective is to preserve the existing character of the landscape. The level of change to the characteristic landscape should be very low and must…
Visual Resource Management (VRM) Classes Categories assigned to BLM lands, utilizing the Visual Resource Inventory Classes in the RMP process, with an objective which prescribes the amount of…
Visual Resource Management (VRM) System BLM's system for minimizing the visual impacts of surface-disturbing activities and maintaining scenic values for the future.
Visual resources Refers to all objects (man-made and natural, moving and stationary) and features such as landforms and water bodies that are visible on a landscape.
Visual sensitivity Public concern for the maintenance of scenic quality in a particular landscape setting.
Visual Spectrum The portion of the electromagnetic spectrum to which the eye is sensitive, i.e., light with wavelengths between 0.4 and 0.7 micrometers.
visual stratigraphy process of identifying different layers in ice, rock, sediment, or other deposit, based on visually apparent distinctions such as color or other…
Visual unity The quality or state of appearing to be united in principles and relationships or to be logically and aesthetically connected because of the visual…
Visual value See Scenic value
vitamin A key nutrient that the body needs in small amounts to grow and stay strong. Examples are vitamins A, C, and E.
Vitamins Various substances that are essential in minute quantities to the nutrition of animals and plants.
vitrified Cultured tissue having leaves and sometimes stems with a glassy, transparent or wet and often swollen appearance.
viviparous (adj.) See: vivipary.
vivipary 1. A form of reproduction in animals in which the developing embryo obtains its nourishment directly from the mother via a placenta or by other means. 2.
VLCTY Velocity
VLY Valley
Vmax The maximal rate of an enzyme-catalysed reaction. Vmax is the product of Eo (the total amount of enzyme ) and Kcat (the catalytic rate constant).
VMD Volume median diameter. A statistical measure of the average droplet size in a spray cloud, such that fifty percent of the volume of sprayed material is…
VNTR Abbreviation for variable number tandem repeat.
Voice broker A trading intermediary matching buyers and sellers using traditional telephone confirmation.
Void Invalid; a void agreement is one for which there is no remedy.
Void ratio The ratio of the volume of void space to the volume of solid particles in a given soil mass.
volatile A solid or liquid material that easily vaporizes.
volatile matter Those products, exclusive of moisture, given off by a material as a gas or vapor, determined by definite prescribed methods that may vary according to the…
Volatile organic compound (VOC) Any organic compound that participates in atmospheric photochemical reactions except those designated by the EPA as having negligible photochemical…
Volatile organic compounds (VOC) Non-methane hydrocarbon gases. Released during combustion or evaporation of fuel.
Volatile organic compounds (VOCs) Organic compounds that evaporate readily into the atmosphere at normal temperatures.
Volatiles Substances that are readily vaporized.
Volatility The term volatility indicates how much and how quickly the value of an investment, market, or market sector changes.
volatilization The conversion of a solid or liquid into a gas or vapour.
Volcanic Ash Consists of rock, mineral, and volcanic glass fragments smaller than 2 millimeters (mm) (0.
Volcanic chain A linear sequence of volcanoes that occurs within a tectonic plate. As the plate moves over a stationary hot spot, new volcanoes are created.
Volcanic cone A landform built by the material ejected from a volcanic vent and piled up around the vent in the shape of a cone with a central crater.
Volcanic rock Rock that forms from the solidification of molten rock or magma at the earth's surface (extrusive igneous rock).
Volcanic vent The opening at the Earth's surface through which volcanic materials issue forth.
Volcanic-rock aquifer See Aquifer-volcanic rock
Volcanism The process by which magma and associated gases rise to the Earth's crust and are extruded, or expelled, onto the surface and into the atmosphere.
Volcano A vent (opening) in the surface of the Earth through which magma erupts. It is also the landform that is constructed by the erupted material.
Volcanoclastic rock Sedimentary rocks such as sandstones formed by the aggregation of rock fragments (clasts) of volcanic origin.
Volt A unit of electrical force equal to that amount of electromotive force that will cause a steady current of one ampere to flow through a resistance of one…
Volt (V) The unit of measurement of electromotive force. It is equivalent to the force required to produce a current of 1 ampere through a resistance of 1 ohm.
Volt-Ampere A unit of electrical measurement equal to the product of a volt and an ampere.
Volt-ampere (VA) A unit of apparent power in an ac circuit containing reactance. It is equal to the potential in volts multiplied by the current in amperes, without taking…