Hope you guys don't mind my two cents but I hope you're assuming something here which I don't see. The units for the Gas Constant used in the Arrhenius' equation is
R (gas constant) = J/mol*K or cal/mol*K That means Ea (activation energy) must be in units J/mol, or cal/mol. If the units of eV's are being used, then all the constants must have their corresponding units changed also to eV's so that R = eV/mol*K and Ea = eV/mol To say that H is simply the units of calories is a little misleading. It's units are cal/mol. Very different concept than simple cals. Regards, Doug Richard Haynes wrote: > > Paul, > Thank you for your suggestion. I hope these comments will be useful. > Richard Haynes > > Applications of the Arrhenius type equation include chemical and > electrochemical reactions and many other systems such as bipolar and MOS > infant mortality. Both temperature and voltage are accelerating factors(D. > Cook, "Method of Determining Reliability Screens for Time Dependent > Dielectric Breakdown ," Proceedings of the International Reliability Physics > Symposium, IEEE, 1979, p. 1.). > When using the Arrhenius type equation several variations of representations > of the energy of activation are being used, such at E( energy of activation > with eV units), H and F( heat and free energy of activation, both in cals or > kcals-kilocals, 1,000 cals). Each means the same measure of energy, that is, > the energy necessary to be supplied so the system can reach the final state. > -----Original Message----- > From: Parker, Thomas P (Paul) <[email protected]> > To: 'Richard Haynes' <[email protected]> > Date: Friday, July 24, 1998 8:54 AM > Subject: RE: AST Tutorial on the Use of Tempature to increase Acceleration > Factor > > Richard - Most people are used to seeing Ea for activation engery in > electron volts, vs H in the Arrhenius equation. I would suggest explaining > that. > > Many failure modes do not necessarily follow Arrhenius, especially > workmanship defects and other mechanical defects. Can you be discuss the > types of failure modes that this equation applies to as well as what it does > not apply to. Actual experimental examples would be great. > > Paul > > > ---------- > > From: Richard Haynes[SMTP:[email protected]] > > Sent: Friday, July 24, 1998 3:02 AM > > To: emc-pstc; accelerated-stress-testing > > Subject: AST Tutorial on the Use of Tempature to increase > > Acceleration Factor > > > > <<File: Temparrt.doc>> > > Greeting Groups, > > I hope this tutorial will clear up some aspects of using the temperature > > to increase the acceleration Factory. > > Please let me know if this was helpful so I can tell my boss. > > Thanks and have a good day. > > Richard Haynes > > > > PS The attached file is in Word 6.0 > >
