Propagation VHF
Propagation can refer to: *Chain propagation in a chemical reaction mechanism *Crack propagation, the growth of a crack during the fracture of materials *Propaganda, non-objective information used to further an agenda *Reproduction, and other forms of multiplication or increase **Plant propagation, the production of more plants **Propagation of schema, in artificial reproduction *Software propagation, the distribution of free software *Wave propagation, the motion of a wave **Radio propagation, the application of wave propagation to radio communications ;In music * Propagation (album), ''Propagation'' (album) *"Propagation", a song by Lower Dens from the album ''Nootropics (album), Nootropics'' {{disambiguation ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Chain Propagation
Chain propagation (sometimes referred to as propagation) is a process in which a reactive intermediate is continuously regenerated during the course of a chemical chain reaction. For example, in the chlorination of methane, there is a two-step propagation cycle involving as chain carriers a chlorine atom and a methyl radical IUPAC Gold Book which are regenerated alternately: :•Cl + CH4 → HCl + •CH3 :•CH3 + Cl2 → CH3Cl + •Cl The two steps add to give the equation for the overall chain reaction: :CH4 + Cl2 → CH3Cl + HCl. Polymerization In a chain-growth polymerization ...[...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Crack Propagation
Fracture mechanics is the field of mechanics concerned with the study of the propagation of cracks in materials. It uses methods of analytical solid mechanics to calculate the driving force on a crack and those of experimental solid mechanics to characterize the material's resistance to fracture. Theoretically, the stress ahead of a sharp crack tip becomes infinite and cannot be used to describe the state around a crack. Fracture mechanics is used to characterise the loads on a crack, typically using a single parameter to describe the complete loading state at the crack tip. A number of different parameters have been developed. When the plastic zone at the tip of the crack is small relative to the crack length the stress state at the crack tip is the result of elastic forces within the material and is termed linear elastic fracture mechanics (LEFM) and can be characterised using the stress intensity factor K. Although the load on a crack can be arbitrary, in 1957 G. Irwin found ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Propaganda
Propaganda is communication that is primarily used to influence or persuade an audience to further an agenda, which may not be objective and may be selectively presenting facts to encourage a particular synthesis or perception, or using loaded language to produce an emotional rather than a rational response to the information that is being presented. Propaganda can be found in news and journalism, government, advertising, entertainment, education, and activism and is often associated with material which is prepared by governments as part of war efforts, political campaigns, health campaigns, revolutionaries, big businesses, ultra-religious organizations, the media, and certain individuals such as soapboxers. In the 20th century, the English term ''propaganda'' was often associated with a manipulative approach, but historically, propaganda has been a neutral descriptive term of any material that promotes certain opinions or ideologies. Equivalent non-English terms have also la ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Reproduction
Reproduction (or procreation or breeding) is the biological process by which new individual organisms – "offspring" – are produced from their "parent" or parents. Reproduction is a fundamental feature of all known life; each individual organism exists as the result of reproduction. There are two forms of reproduction: asexual and sexual. In asexual reproduction, an organism can reproduce without the involvement of another organism. Asexual reproduction is not limited to single-celled organisms. The cloning of an organism is a form of asexual reproduction. By asexual reproduction, an organism creates a genetically similar or identical copy of itself. The evolution of sexual reproduction is a major puzzle for biologists. The two-fold cost of sexual reproduction is that only 50% of organisms reproduce and organisms only pass on 50% of their genes.John Maynard Smith ''The Evolution of Sex'' 1978. Sexual reproduction typically requires the sexual interaction of two specializ ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Plant Propagation
Plant propagation is the process by which new plants grow from a variety of sources: seeds, cuttings, and other plant parts. Plant propagation can also refer to the man-made or natural dispersal of seeds. Propagation typically occurs as a step in the overall cycle of plant growth. For seeds, it happens after ripening and dispersal; for vegetative parts, it happens after detachment or pruning; for asexually-reproducing plants, such as strawberry, it happens as the new plant develops from existing parts. Plant propagation can be divided into four basic types: sexual, asexual (vegetative), layering, and grafting. Countless plants are propagated each day in horticulture and agriculture. The materials commonly used for plant propagation are seeds and cuttings. Sexual propagation Seeds and spores can be used for reproduction (e.g. sowing). Seeds are typically produced from sexual reproduction within a species because genetic recombination has occurred. A plant grown from seeds may ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Propagation Of Schema
A schema () is a template in computer science used in the field of genetic algorithms that identifies a subset of strings with similarities at certain string positions. Schemata are a special case of cylinder sets, forming a basis for a product topology on strings. In other words, schemata can be used to generate a topology on a space of strings. Description For example, consider binary strings of length 6. The schema 1**0*1 describes the set of all words of length 6 with 1's at the first and sixth positions and a 0 at the fourth position. The * is a wildcard symbol, which means that positions 2, 3 and 5 can have a value of either 1 or 0. The ''order of a schema'' is defined as the number of fixed positions in the template, while the ''defining length'' \delta(H) is the distance between the first and last specific positions. The order of 1**0*1 is 3 and its defining length is 5. The ''fitness of a schema'' is the average fitness of all strings matching the schema. The fitness o ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Software Propagation
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general use and was originally written by the founder of the Free Software Foundation (FSF), Richard Stallman, for the GNU Project. The license grants the recipients of a computer program the rights of the Free Software Definition. These GPL series are all copyleft licenses, which means that any derivative work must be distributed under the same or equivalent license terms. It is more restrictive than the Lesser General Public License and even further distinct from the more widely used permissive software licenses BSD, MIT, and Apache. Historically, the GPL license family has been one of the most popular software licenses in the free and open-source software domain. Prominent free software programs licensed under the GPL include the Linux ker ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Wave Propagation
Wave propagation is any of the ways in which waves travel. Single wave propagation can be calculated by 2nd order wave equation ( standing wavefield) or 1st order one-way wave equation. With respect to the direction of the oscillation relative to the propagation direction, we can distinguish between longitudinal wave and transverse waves. For electromagnetic waves, propagation may occur in a vacuum as well as in the material medium. Other wave types cannot propagate through a vacuum and need a transmission medium to exist. Reflection of plane waves in a half-space The propagation and reflection of plane waves—e.g. Pressure waves (P-wave) or Shear waves (SH or SV-waves) are phenomena that were first characterized within the field of classical seismology, and are now considered fundamental concepts in modern seismic tomography. The analytical solution to this problem exists and is well known. The frequency domain solution can be obtained by first finding the Helmholtz deco ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Radio Propagation
Radio propagation is the behavior of radio waves as they travel, or are propagated, from one point to another in vacuum, or into various parts of the atmosphere. As a form of electromagnetic radiation, like light waves, radio waves are affected by the phenomena of reflection, refraction, diffraction, absorption, polarization, and scattering. Understanding the effects of varying conditions on radio propagation has many practical applications, from choosing frequencies for amateur radio communications, international shortwave broadcasters, to designing reliable mobile telephone systems, to radio navigation, to operation of radar systems. Several different types of propagation are used in practical radio transmission systems. ''Line-of-sight propagation'' means radio waves which travel in a straight line from the transmitting antenna to the receiving antenna. Line of sight transmission is used for medium-distance radio transmission, such as cell phones, cordless phones, walkie- ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Propagation (album)
''Propagation'' (1994) is an album by the American ambient musician Robert Rich. This album is an expression of Rich’s interest in biology and is a tribute to the proliferation of organic life in all its forms. It features a complex range of world music influences, just tunings and guest performers, similar to ''Rainforest'' (1989). Track listing #”Animus” – 9:29 #”Lifeblood” – 5:31 #”Whispers of Eden” – 7:35 #”Terraced Fields” – 4:24 #”Luminous Horizon” – 9:45 #”Spirit Catcher” – 9:25 #”Guilin” – 11:11 Personnel *Robert Rich – Wavestation, Morpheus, Proteus/3, DX711D, EPS16+, Prophet-5, bamboo and PVC flutes, ocarinas, lap steel guitar, fretless bass, su gzeng, zither, brass and clay dumbeks, tar, udu, talking drums, kendang, Waterphone, windwand and whirlies, key tree, Woodstock chimes, rainstick, shakers, “glurp” *Andy Wiskes – environmental source recordings (“glurp food”) *Lisa Moskow – sarod (track 3) * Forres ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |