Biocatalysis/Biodegradation Database - University of Minnesota Biocatalysis/Biodegradation Database lists microbial biocatalytic reactions and biodegradation pathways primarily for xenobiotic, chemical compounds.
Engineering Power Tools - Engineering software solves many common engineering problems quickly and efficiently. Includes unit converter, and many frequently- used data tables such as physical constants, properties of materials, screw threads, and piping pressure drop. Free downloads. Win3.x/95/98/NT.
EquationSheet.com - Searchable directory, arranged by field, of equations, constants, symbols and SI units. Also features LaTEX utilities, software links.
Fundamental Physical Constants from NIST - CODATA Internationally recommended values for a wide range of physical parameters (speed of light, Avogadro's constant, masses of elementary particles, Planck constant, and acceleration of gravity).
GrayLIT Network - Provides a full-text search across the gray literature of multiple government agencies within a science portal of technical reports.
RefScout - A weekly, scientific reference mailing service. Screens databases covering life and medical sciences for the key words or the combination of key words specified and will automatically update with any abstract that has come up during the last seven days. Free service.