Synthesis [edit]. Quaternary ammonium compounds are prepared by the alkylation of tertiary amines with a halocarbon. In older literature this is often called a Menshutkin reaction, however modern chemists usually refer to it simply as quaternization.uaternary ammonium compounds have also been shown to have antimicrobial activity. Certain quaternary ammonium compounds, especially those containing long alkyl chains, are used as antimicrobials and disinfectants.
Answer: XPF files are Uncommon Files primarily associated with XaoS Position File (Jan Hubicka Thomas Marsh Zoltan Kovacs and Others).
The Exif and JFIF standards define the commonly used formats for interchange of JPEG-compressed images. A JPG file consists of a sequence of segments, each beginning with a marker, each of which begins with a 0xFF byte followed by a byte indicating what kind of marker it is. Some markers consist of just those two bytes; others are followed by two bytes indicating the length of marker-specific payload data that follows.