Per Scholas programs. Per Scholas brings more than 20 years of experience in recovering, handling and processing retired IT equipment. Per Scholas was featured in WIRED magazine in November 2014. Four Per Scholas graduates were featured in the New York Times in the winter of 2014. In 2012, Per Scholas was named one of America's top-performing nonprofit organizations by the Social Impact Exchange S&100 Index for its impressive outcomes and results-driven work. Per Scholas received a Heroes Award from the Robin Hood Foundation in 2011. The Per Scholas board of directors includes several prominent professionals in the IT field. Current Chairman Lewis
Parts-per notation Since it is usually not stated which quantity is used, it is better to write the unit as kg/kg, mol/mol or m/m (even though they are all dimensionless). The difference is quite significant when dealing with gases and it is very important to specify which quantity is being used. For example, the conversion factor between a mass fraction of 1 ppb and a mole fraction of 1 ppb is about 4.7 for the greenhouse gas CFC-11 in air. For volume fraction, the suffix "V" or "v" is sometimes appended to the parts-per notation (e.g., ppmV, ppbv, pptv). Unfortunately, ppbv and