Marker


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marker

[′märk·ər]
(immunology)
Any antigen that serves to distinguish cell types.
(ordnance)
A sign or signal for marking a location on land or water; frequently contains pyrotechnics.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Marker

 

a device for guiding a sower or planter to form interrows of a planned width. A marker consists of an extendable bar connected by a hinge to a sower or hitch. On the outer end of the bar is a disk, which is mounted at an angle and rotates freely; as it moves over the field, it leaves a furrow in the un-seeded area. On the next pass of the unit the furrow is used to guide the right front wheel or the inside edge of the right track of a tractor. Sowers and planters usually operate with right and left markers. The overlap (M) of the marker is determined according to the following formulas:

where a is the distance between the front wheels or the inside edges of the tracks, B is the distance between the extreme colters of the sower, and C is the size of the interrow.


Marker

 

an attachment to a single- or double-row sower that ensures parallel rows of seeds in subsequent passes. A marker consists of a beam with a weight on the end; the beam is secured to the front of the tractor. The tractor is steered so that the weight of the marker is above the track left by the planter wheel or marker disk on the preceding pass. Markers are often made reversible so that they can be used on both sides of the tractor.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.

marker

A sign, plaque, or monument that designates a building, site of historic importance, or boundary.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.

marker

markerclick for a larger image
Distance to go markers on the sides of runway.
An object displayed above ground level in order to indicate an obstacle or delineate a boundary (ICAO). Markers should be frangible, and those located near a runway or taxiway should be sufficiently low to ensure clearance for propellers and the engine pods of jet aircraft. The various types of markers are the distance-to-go markers, unpaved runway-edge markers, stop-way-edge markers, taxiway-edge markers, taxiway centerline markers, boundary markers, and unpaved taxiway-edge markers.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
References in periodicals archive ?
While pure gold fiducial markers continue to be profitable, demand for metal-based fiducial markers is also foreseen to scale new heights owing to their ability in providing superior accuracy in target delivery of beam of radiation.
'While many Cultural Properties have historical markers installed, not all places marked with historical markers are designated into one of the particular categories of Cultural Properties.
Delima said KWF hopes to put up markers for all indigenous Filipino languages and will attempt to install 20 markers in 2019.
He said that Marker earned a wide reputation as a suave and skilled envoy who always promoted Pakistan's positive image.
He (Jamsheed Marker) was also a statesman par excellence, who strengthened relations with powerful countries at a new level, he said.
The Prime Minister said Jamsheed Marker was one of the country's most distinguished diplomats who left deep marks in all areas of diplomatic front he worked at.
Cells were stained with lineage specific monoclonal antibodies against cell specific CD markers through lyse wash procedure.
Mr Marker was awarded the Victoria Medal for his military service, along with other decorations.
Marker played role in bringing out resolution of the East Timor conflict and its independence.
Samples were measured for 4 min when triggering on EpCAM-APC, CD61-APC, or generic marker fluorescence and for 1 min when triggering on side scatter (405-nm laser).
Comparative analysis of ISSR marker polymorphism in populations of yak (Bosmutus) and in F1 hybrids between yak and cattle in the Sayan-Altai region.