Linkage


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linkage

1. Engineering a system of interconnected levers or rods for transmitting or regulating the motion of a mechanism
2. Electronics the product of the total number of lines of magnetic flux and the number of turns in a coil or circuit through which they pass
3. Genetics the occurrence of two genes close together on the same chromosome so that they are unlikely to be separated during crossing over and tend to be inherited as a single unit
4. the fact of linking separate but related issues in the course of political negotiations

Linkage (genetics)

Failure of two or more genes to recombine at random as a result of their location on the same chromosome pair. Among the haploid products of a cell which has gone through meiosis, two genes located in the same chromosome pair remain in their two original combinations of alleles (“parental”) unless an odd number of exchanges of homologous segments occurred within the interval bounded by their loci. The incidence of exchanges of homologous segments at meiosis is roughly proportional to the length of the chromosome segment between two loci. The percentage of recombinants thus provides an estimate of this length and a basis for constructing gene maps on which linked loci are arranged in linear order and spaced out in proportion to the recombination percentages between them. See Meiosis

Linkage

 

a mechanism consisting of links joined together in lower kinematic pairs. Linkages can be plane or spatial. In plane linkages, the links make contact around a circumference (hinges, turning pairs) or along a line (sliding pairs). In spatial linkages, the links are joined over cylindrical or spherical surfaces (turning pairs) or over planes (sliding pairs). Link gears and slider-crank mechanisms are also considered to be linkages. In technical literature, linkages are often referred to as pin-connected mechanisms.

Linkages are simpler to fabricate, stronger, and more resistant to wear than cam and gear mechanisms. As a result, they are employed to transmit large forces in, for example, presses, forging machines, internal combustion engines, and loaders.


Linkage

 

(in Russian, sharnir), a movable connection between two bodies. In a cylindrical linkage, the relative movement of the two bodies is rotation about an axis; in a spherical linkage, the relative movement is rotation about a point.

A cylindrical linkage in a mechanism is called a rotary kinematic pair. It consists of a journal rotating in either a simple bearing or a rolling-contact bearing.

A spherical linkage in a mechanism is referred to as a spherical kinematic pair. It may be either a ball and socket or a ball bearing. Such a linkage is difficult to manufacture. Therefore, it is often replaced by a universal joint, which consists of two or three cylindrical linkages that are connected in tandem and whose axes of rotation intersect at a single point. Various modifications of the universal joint may be used instead of a spherical linkage; such modifications differ in the number of intermediate links and in the type of kinematic pairs formed by the intermediate links.

A linkage may be exposed or enclosed. An enclosed linkage is protected from dust or sand by a housing and is used in machinery that operates in air with a high dust content.

Linkages are used not only in machine mechanisms but also in building systems, such as trusses. In such systems, linkages are employed to relieve the components of bending stresses and to reduce thermal stresses.

N. I. LEVITSKII

linkage

[′liŋ·kij]
(computer science)
In programming, coding that connects two separately coded routines.
(electromagnetism)
(genetics)
Failure of nonallelic genes to recombine at random in meiosis as a result of their being located within the same chromosome.
(mechanical engineering)
A mechanism that transfers motion in a desired manner by using some combination of bar links, slides, pivots, and rotating members.

Linkage (mechanism)

A set of rigid bodies, called links, joined together at pivots by means of pins or equivalent devices. A body is considered to be rigid if, for practical purposes, the distances between points on the body do not change. Linkages are used to transmit power and information. They may be employed to make a point on the linkage follow a prescribed curve, regardless of the input motions to the linkage. They are also used to produce angular or linear displacement. See Mechanism

If the links are bars the linkage is termed a bar linkage. A common form of bar linkage is one for which the bars are restricted to a given plane, such as a four-bar linkage. A commonly occurring variation of the four-bar linkage is the linkage used in reciprocating engines (see illustration). Slider C is the piston in a cylinder, link 3 is the connecting rod, and link 4 is the crank. (Link 1 is the fixed base, A and D are pivots, R is the length of the crank, L is the length of the connecting rod, and Θ denotes the angle of the crank.) This mechanism transforms a linear into a circular motion, or vice versa. The straight slider in line with the crank center is equivalent to a pivot at the end of an infinitely long link. See Pantograph

References in periodicals archive ?
Differently from existing studies, our work focuses on the application of agglomerative hierarchical clustering algorithm using a novel linkage method, called k-Linkage.
e1], the genome length was estimated by adding 2s (where s is the average space of the linkage map) to the length of each group.
The booklet provides an overview of the electronic linkage strategy and its objectives and priorities.
The electronic linkage project helps update the file of civil and individual data of all UAE population instantly, thereby reducing duplication and repetition of data and enhancing the national and individual security by strengthening the personal identity in the UAE through the interdependent databases of the UAE organizations, notably the ministries of interior, justice, education, higher education, health and labor, these being responsible for such major civil incidents as birth, marriage, divorce, citizenship, residency, death, education, health record, supporting documents etc.
Before your dozer heads off to the paint shop, tape over the throttle linkage where it connects into the mounting bracket.
To design the CCMT, Linkages database, and Linkage referral notice applications, a workgroup was created with participant services employment resource specialists/supervisors, CWS social workers/supervisors, information technology software engineers, staff development program managers and regional managers.
However, margins should stabilize starting 2012 after the overseas market take-up and synergies from Linkage merger begin to materialise.
names and medical record numbers) is the gold standard for linking data-sets, these linkage methods have not been feasible for the ANZICS APD.
He added that the meeting reviewed a host of the outcomes of GCC joint action like approving a special study on tariffs and fees that will be applied by the GCC Interconnection Authority (GCCIA) along with passing the code of GCC electricity linkage network and setting up consultative and organizational committee for GCC that will emanate from signing the electric linkage agreement.
Earlier this year the Supreme Court issued welcome clarification on how the Linkage Regulation applies to formulation patents and their publication in the Linkage Gazette.