ViroidA plant pathogen that consists of a naked RNA molecule of approximately 250-350 nucleotides, whose extensive base pairing results in a nearly correct…
Virtual biddingIn two-settlement electricity markets, financial transactions that allow participants to hedge against the risk that real-time and day-ahead prices will…
Virtual Potential TemperatureThe 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 TemperatureThe 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…
virulenceThe ability of a microorganism to cause damage to its host.
viruliferousA 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-freePlant, animal, cell, tissue or meristem which exhibits no viral symptoms or contains no identifiable virus particles.
virus-testedDescription of a organism or a cell stock certified as being free of certain specified virus es following recognized procedures of virus diagnosis.
VIS1. Visible satellite imagery 2. Visibile or Visibility
ViscosityThe 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.
VisibilityThe distance at which a given standard object can be seen and identified with the unaided eye
Visibility factorsConditions or other phenomena that affect the visibility or appearance of an object or a landscape.
Visibility Protection ProgramThe program specified by the Clean Air Act to achieve a national goal of remedying existing impairments to visibility and preventing future visibility…
Visible LightElectromagnetic radiation from about 400 to 700 nm, which is detectable by the human eye.
Visible Light TransmittanceThe amount of visible light that passes through the glazing material of a window, expressed as a percentage.
Visible MassMass that gives off electromagnetic radiation, so that it can be detected. It is ordinary (baryonic) matter.
Visible RadiationThe visible portion of the electromagnetic spectrum with wavelengths from 0.4 to 0.76 microns
Visible Satellite ImageryThis 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 UniverseThe part of the entire universe from which light would have had time to reach us in the age of the universe.
Visitor dayTwelve visitor hours which may be aggregated by one or more persons in single or multiple visits.
Visitor useVisitor use of recreation and wilderness resource for inspiration, stimulation, solitude, relaxation, education, pleasure, or satisfaction.
Visual absorption capabilityThe physical capacity of a landscape to accept human alterations without loss of its inherent visual character or scenic quality.
Visual attentionNoticing and focusing of vision on a particular object or landscape element.
Visual clutterThe complex visual interplay of numerous disharmonious landscape characteristics and features resulting in a displeasing view.
Visual contrastOpposition or unlikeness of different forms, lines, colors, or textures in a landscape.
Visual disharmonyA state of disagreement, incongruity, or disproportionate arrangement of forms, lines, colors, and textures in the visual elements of a seen landscape.
Visual featureAn element, such as a land or water form, vegetation, or structure in the seen landscape.
Visual harmonyA 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 impactAny modification in land forms, water bodies, or vegetation, or any introduction of structures, which negatively or positively affect the visual character…
Visual intrusionAny 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 mitigationActions taken to avoid, eliminate, or reduce potential adverse impacts on scenic resources.
Visual Resource Management (VRM) Class Designations(VRM)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(VRM)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(VRM)BLM's system for minimizing the visual impacts of surface-disturbing activities and maintaining scenic values for the future.
Visual resourcesRefers 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 sensitivityPublic concern for the maintenance of scenic quality in a particular landscape setting.
Visual SpectrumThe portion of the electromagnetic spectrum to which the eye is sensitive, i.e., light with wavelengths between 0.4 and 0.7 micrometers.
visual stratigraphyprocess of identifying different layers in ice, rock, sediment, or other deposit, based on visually apparent distinctions such as color or other…
Visual unityThe quality or state of appearing to be united in principles and relationships or to be logically and aesthetically connected because of the visual…
vivipary1. 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.
VmaxThe maximal rate of an enzyme-catalysed reaction. Vmax is the product of Eo (the total amount of enzyme ) and Kcat (the catalytic rate constant).
VMDVolume 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…
VNTRAbbreviation for variable number tandem repeat.
Voice brokerA trading intermediary matching buyers and sellers using traditional telephone confirmation.
VoidInvalid; a void agreement is one for which there is no remedy.
Void ratioThe ratio of the volume of void space to the volume of solid particles in a given soil mass.
volatileA solid or liquid material that easily vaporizes.
volatile matterThose 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)(VOC)Any organic compound that participates in atmospheric photochemical reactions except those designated by the EPA as having negligible photochemical…
VolatilityThe term volatility indicates how much and how quickly the value of an investment, market, or market sector changes.
volatilizationThe conversion of a solid or liquid into a gas or vapour.
Volcanic AshConsists of rock, mineral, and volcanic glass fragments smaller than 2 millimeters (mm) (0.
Volcanic chainA linear sequence of volcanoes that occurs within a tectonic plate. As the plate moves over a stationary hot spot, new volcanoes are created.
Volcanic coneA 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 rockRock that forms from the solidification of molten rock or magma at the earth's surface (extrusive igneous rock).
Volcanic ventThe opening at the Earth's surface through which volcanic materials issue forth.
VolcanismThe 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.
VolcanoA 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 rockSedimentary rocks such as sandstones formed by the aggregation of rock fragments (clasts) of volcanic origin.
VoltA 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-AmpereA 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…
VoltageThe amount of electromotive force, measured in volts, that exists between two points.
Voltage (E)Electrical pressure, i.e. the force which causes current to flow through an electrical conductor.
Voltage reductionAny intentional reduction of system voltage by 3 percent or greater for reasons of maintaining the continuity of service of the bulk electric power supply…
Volume of ConcreteThe total space occupied by concrete forming the dam structure computed between abutments and from the top to the bottom of the dam.
Volume of damThe total space occupied by the materials forming the dam structure computed between abutments and from the top to the bottom of the dam.
Volume ScanA radar scanning strategy in which sweeps are made at successive antenna elevations (i.e.
Volume Velocity ProcessingA way to guess the large-scale 2-dimensional winds, divergence and fall speeds from one-dimensional radial velocity data.
Volumetric riskThe effect on revenue of fluctuations in demand for a product or service.