impurity


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Related to impurity: impurity band, dissensions

impurity

Electronics a small quantity of an element added to a pure semiconductor crystal to control its electrical conductivity

impurity

[im′pyu̇r·əd·ē]
(science and technology)
An undesirable foreign material in a pure substance.
(solid-state physics)
A substance that, when diffused into semiconductor metal in small amounts, either provides free electrons to the metal or accepts electrons from it.
References in periodicals archive ?
For example, we plan to adjust inspections of API sites to include enhanced evaluation of impurity controls, particularly when the manufacturing process may lead to the formation of a nitrosamine or when recycled raw materials can create unacceptable contamination.
The recalled blood pressure medication has trace amounts of an unexpected impurity, N-Nitroso-N-methyl-4-aminobutyric acid (NMBA), above the limits allowed by the U.S.
At that time, the Prime Minister had hit out at the Opposition parties which are making efforts to forge an anti-BJP coalition for Lok Sabha elections, terming it as aACoemaha milawat (grand impurity)" which will "never" come to power.
Cruz Manila showed that the impurity patterns are of high similarities.
A DRAP official's statement that 'it was not unusual for an impurity to be found in a medicine and the pharmacopoeia deals with such issues,' is not only unscientific but ridiculous.
However, if the impurity is of some special type, which do not change the dielectric constant of the fuel, that will not be detected.
Applying CAD to impurity detection could help overcome some of the obstacles met with UV/Vis detection, since CAD response does not require a chromophore for detection and can provide a uniform response independent of chemical structure.
However, if the final product is shown to have elemental impurities, it may be difficult to identify the source of the impurity.
M2 PHARMA-March 7, 2018-Sagent Pharmaceuticals Recalls Methylprednisolone Sodium Succinate for Injection, USP, 40mg, 125mg, and 1g Due to High Level of Impurity
Simvastatin CRS (purity 99.7% "as is"), Simvastatin impurity E (Lovastatin), and Simvastatin for peak identification were provided by European Directorate for the Quality of Medicines and Health Care Council of Europe (EDQM-Strasbourg, France).
Differences in diffusion coefficients lead to formation of the so-called "tails" in the impurity distribution depthwise, which significantly reduces quality of the p-n junctions fabricated by means of thermal diffusion.
The performance of a radiation semiconductor detector depends on several factors related to the crystal quality, such as the carrier lifetime, mobility, crystallographic imperfections, and the impurity concentrations present in the crystal.