German term (edited): Schaumkennzaghl SKZ

For all who will consult this page in future:

Foam Index test is a rapid method to determine the relative levels of Air Entraining Agent (AEA) needed during concrete mixing, with or without mineral additives like combustion fly ash, that control air void volumes within cured concrete.[1][2]
https://en.wikipedia.org/wiki/Foam_Index

A Foam Index is calculated using foam and flat beer values during the first. 5 minutes and the "break" time.
https://www.google.de/search?biw=1306&bih=954&ei=za7TX9yTG4a...

Earlier studies3 on espresso coffee prepared by using arabica/robusta (40:60) blend reported the foam volume, measured in a graduated beaker immediately after percolation, as a function of water content of the ground roasted coffee, of compaction in the filter holder and of coffee portion.
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Illy and Viani34 defined as “foam index” the ratio between foam and liquid volumes. A “foam index” of at least 10% is expected for a correct preparation.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3140933/

Brewhouse | Lauter tun | Omnium
Foam Index | 113 FI | 122 FI
https://www.vlb-berlin.org/sites/default/files/2019-06/MO07-...

A process for determining at least one foam degradation rating number for foam on a liquid, in particular beer, has the following steps: foaming the liquid, filling a measurement vessel with the foamed liquid, then measuring the amount of liquid formed in the measurement vessel from the foam as a function of time.
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It proves advantageous to define a foam index S K :
https://patents.google.com/patent/DE4237807A1/en

Es erweist sich als günstig, eine Schaumkennzahl SK zu definieren:
https://patents.google.com/patent/DE4237807A1/de
(Note: German patent)

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Note added at 18 hrs (2020-12-12 11:09:07 GMT)
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Exists another acronym in English?

One of the widely used empirical methods of assessing the dosage rate of AEAs in mixtures containing fly ash has been the Foam Index (FI) test—a subjective test with a very high degree of variability depending on the operator’s experience and the device used.
https://www.fhwa.dot.gov/publications/research/infrastructur...

The Foam Index (FI) test measures the dosage of AEA (Air Entraining Agent) to obtain stable foam on top of a slurry, indicating the stability of air entrainment in concrete, particularly when using fly ash with variable carbon content.
https://core.ac.uk/download/pdf/52125938.pdf

Foams or emulsions (hereinafter collectively referred to as “foams”) are ubiquitous in various processing operations. Foam sometimes creates or provides certain desirable product characteristics, such as a specific consistency of food or taste in a beverage (e.g., beer), and is thus considered advantageous.
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Experimental testing has confirmed that the foam index (FI) of mineral admixtures used in concrete could be measured using acoustic emission techniques.
https://patents.justia.com/patent/7770455

4.2 Understanding of foam in a general context
Foams can be found in a wide variety of contexts. They occur in the form of soap froth, fire-fighting foam, the head on a glass of beer, the froth in a washing-up bowl, and many more.
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4.6Foam Decay and Foam Index (FI)
4.6.1Characteristics of foamed bitumen decay
https://www.nottingham.ac.uk/research/groups/ntec/documents/...

5).Based on experimental work on a number of slag systems at high temperature, Fruehan and co-workers derived an empirical equation on the basis of dimensional analysis that predicts the Foam Index as a function of the physical properties of the slags …
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For example, if the sizes of bubbles are small, such as those encountered in beer or milk foams, their corresponding average rise velocity is aIso very small.
https://www.google.de/url?sa=t&rct=j&q=&esrc=s&source=web&cd...

Conclusion: foaming index is a generic term for all foam types and is abbreviated ‚FI‘ in English.