delta

The title of this article is ambiguous. Further meanings are listed under Delta (disambiguation) .

delta
pronunciation
antique	[ d ] ​​
modern	[ ð ] ​​
Equivalents
Latin	D.
Cyrillic	Д
Hebrew	ד
Arabic	د
Phoenician	?
transcription
From the ancient world	d
From the modern	d
Coding Capitals Unicode number U + 0394 Unicode name GREEK CAPITAL LETTER DELTA HTML & # 916; HTML entity Δ Minuscule Unicode number U + 03B4 Unicode name GREEK SMALL LETTER DELTA HTML & # 948; HTML entity δ

The delta ( Greek Δέλτα , capital letter : Δ, lower case letter : δ) is the fourth letter in the Greek alphabet and has the numerical value 4 according to the Milesian system .

origin

The sign comes from the Phoenician letter Daleth .

example

• Diogenes ( Διογένης )

use

In Greek

In the Greek number font lower-case letter represents δ the number 4 and together with subscript number sign as ͵δ the number 4000. Because of the shape of the capital letter Δ is (since Herodotus histories 2.13 and more often) the lying between the Nilarmen part Lower Egypt as Delta designated , as in the German river delta in general. In addition, the comedy writer Aristophanes uses Delta in Lysistrata verse 151 to denote female shame .

The Greek letter delta as such - and derived as a symbol for calculation quantities, parameters and the like - is also used in many different contexts and areas of knowledge .

mathematics

• The large delta (Δ) serves as the difference sign for
  • the difference, see subtraction
  • the difference operator - further parameters are derived from this
  • the symmetrical difference of set theory
  • the Laplace operator (the sum of the second partial derivatives in each spatial direction)
• The small delta (δ) denotes
  • the derivative of variation or virtual displacement
  • Dirac's δ 'function', see delta distribution
  • the Kronecker Delta
  • an infinitesimal (hence a small delta), path-dependent change (not a complete differential) of process variables that only occur when the state changes.

An inverted large delta ∇ is called a nabla . The symbol ( TeX ) that denotes a triangle is not a delta . ${\displaystyle \triangle }$ triangle

Science and Technology

• The large delta (Δ) is used
  • in physics as an identifier for four baryons (Δ ⁺⁺ , Δ ⁺ , Δ ⁰ and Δ ^- ).
  • in molecular biology as a marking of deletions .
  • as a term symbol for the characterization of energy states, for example in the singlet oxygen ¹ Δ _g
• The small delta (δ) denotes
  • generally a small difference in arithmetic or measured variables , e.g. B. of times (mostly δt ) or distances ( δs ), in geodesy of small angle and vector differences , or in geometry and adjustment calculations of coordinate allowances (e.g. δx , δy )
  • in NMR spectroscopy the chemical shift
  • in electrical engineering the so-called loss angle , as well as the equivalent thickness of the conductive layer in the skin effect
  • in chassis or vehicle technology, etc. a. the steering angle
  • in anatomy, in Aδ fiber , a nerve fiber
  • in electroplating the layer thickness
  • a clast type in structural geology (see delta clast )

chemistry

• A large delta (Δ) indicates
  • on a reaction arrow the supply of heat
  • with one or more subsequent superscript locants the position of double bonds in
    • partly hydrogenated cyclic compounds (e.g., Δ ³ -carene , Δ ⁹ -tetrahydrocannabinol , often in the literature for steroids and Indigo used derivatives)
    • unsaturated fatty acids (such as Δ ^9,12,15 -octadecatrienoic acid )
• A small delta (δ) denotes
  • an atomic or molecular partial charge
  • the δ bond , a metal-to-metal quadruple bond that occurs when two parallel d orbitals of two metals overlap
  • as locant the distance of an atom from a reference atom or a linkage point ( e.g. δ-valerolactone )
  • with a preceding locant and the following superscript number the position and number of cumulative double bonds based on an atom, see δ-convention

astronomy

• The small delta (δ) denotes the declination (astronomy) , one of the two equatorial coordinates of stars,
• as well as the third to fifth brightest star of each of the 88 constellations ,
• and the more detailed designation of some meteor streams in order to describe the position of the radiant more precisely in large constellations.

Named sizes and procedures

• Data processing:
  • Delta coding , differential storage, a possibility of data compression
• Economics:
  • in option theory, the first partial derivation of the option price model based on the price of the underlying asset or underlying.
  • an indicator from the valuation of options; see option (economy) #Delta
  • as a small delta (δ) the depreciation rate of a capital stock (compare Solow model ).

Others

In the Canadian syllabary there is one letter that looks like the great delta.

Web links

Wiktionary: Delta  - explanations of meanings, word origins, synonyms, translations

Individual evidence

1. ^ IUPAC rule 1.2 , accessed on April 23, 2017.
2. ↑ G. Löffler, P. Petrides: Biochemie und Pathobiochemie , 7th edition, Springer Verlag, Berlin 2002, ISBN 3-540-42295-1 , p. 35.
3. ↑ IUPAC Rule 1.1.4 , accessed on 23 April 2017th