Inhibitor

Inhibitor or inhibition may refer to:

In biology

In chemistry

In psychology and neurology

Reaction inhibitor

A reaction inhibitor is a substance that decreases the rate of, or prevents, a chemical reaction. A catalyst, in contrast, is a substance that increases the rate of a chemical reaction.

Examples

2H
2O
2 → 2H
2O + O
2, which is catalyzed by heat, light, and impurities.

Inhibition of a catalyst

An inhibitor can reduce the effectiveness of a catalyst in a catalysed reaction (either a non-biological catalyst or an enzyme). E.g., if a compound is so similar to (one of) the reactants that it can bind to the active site of a catalyst but does not undergo a catalytic reaction then that catalyst molecule cannot perform its job because the active site is occupied. When the inhibitor is released, the catalyst is again available for reaction.

Inhibition and catalyst poisoning

Inhibition should be distinguished from catalyst poisoning. An inhibitor only hinders the working of a catalyst without changing it, whilst in catalyst poisoning the catalyst undergoes a chemical reaction that is irreversible in the environment in question (the active catalyst may only be regained by a separate process).

Rasā

Rasa (rásā रसा) means "moisture, humidity" in Vedic Sanskrit, and appears as the name of a western tributary of the Indus in the Rigveda (verse 5.53.9).

In RV 9.41.6, RV 10.108 and in the Nirukta of Yaska, it is the name of a mythical stream supposed to flow round the earth and the atmosphere (compare Oceanus), also referring to the underworld in the Mahabharata and the Puranas (compare Styx).

The corresponding term in Avestan is Ranha. In the Vendidad, Ranha is mentioned just after Hapta-Həṇdu, and may possibly refer to the ocean (Sethna 1992).

References

Sun Raster

Sun Raster was a raster graphics file format used on SunOS by Sun Microsystems. The format has no MIME type, it is specified in @(#)rasterfile.h 1.11 89/08/21 SMI. The format was used for some research papers.

ACDSee, FFmpeg, GIMP, ImageMagick, IrfanView, LibreOffice, Netpbm, PaintShop Pro, and XnView among others support Sun Raster image files. In version 2.13 XnView supported the file extensions .ras and .sun for this graphics file format. In version 2.1.4 FFmpeg could encode and decode Sun Raster pixel formats bgr24, pal8, gray, and monow. The format does not support transparency.

The plain text Sun icon format specified in @(#)icon_load.h 10.5 89/09/05 SMI is unrelated to the Sun Raster format.

References

RAS

RAS or Ras may refer to:

People and titles

Locations

Societies and groups