ABSTRACTS OF TECHNICAL ARTICLES 507 



elusions which are useful to circuit and device design are reached. The analysis 

 is deemed sufficiently accurate for first-order equiUbrium calculations. 



Transistors having properties specifically intended for pulse service in the cir- 

 cuits described have been developed. Their properties, limitations, and parame- 

 ter characterizations are discussed at some length. 



Mobility of Electrons in Germanium. P. P. Debye^ and Esther M. 

 ConwellI. Letter to the Editor. Phys. Rev., 87, pp. 1131-1132, Sept. 

 15, 1952. 



The Telephone Industry in National Defense. C. A. Armstrong^. Te- 

 lephony, 143, pp. 44-46, 114, Oct. 25, 1952. 



Infrared Absorption in High Purity Germanium. H. B. Briggs^ Letter 

 to the Editor. Jl. Opt. Soc. Am., 42, pp. 686-687, Sept., 1952. 



New Infrared Absorption Bands in p-Type Germanium. H. B. Briggs^ 

 and R. C. Fletcher^ Letter to the Editor. Phys.'Rev., 87, pp. 1130-1131, 

 Sept. 15, 1952. 



Automatic Switching for Nation-Wide Telephone Service. A. B. Clark^ 

 and H. S. Osborne^. A.I.E.E., Trans. Commun. and Electronics Sect., 

 2, pp. 245-248, Sept., 1952. (Monograph 2015). 



Western Electric' s Service with Standards. K. B. Clarke^ Standardi- 

 zation, 23, pp. 332-338, Oct., 1952. 



Properties of Silicon and Germanium. Esther M. Conwell^ I.R.E., 

 Proc, 40, pp. 1327-1337, Nov., 1952. 



This article provides the latest experimental information on those fundamental 

 properties of germanium and silicon which are of device interest, currently or 

 potentially. Electrical properties, especially carrier density and mobility, have 

 been treated in greatest detail. Descriptive material has been provided to the 

 extent necessary to give physical background. 



Effects of Space-Charge Layer Widening in Junction Transistors. J. M. 

 Earlyi. LR.E., Proc, 40, pp. 1401-1406, Nov., 1952. 



Some effects of the dependence of collector barrier (space-charge layer) thick- 

 ness on collector voltage are analyzed. Transistor base thickness is shown to 

 decrease as collector voltage is increased, resulting in an increase of the current- 

 gain factor (a) and a decrease in the emitter potential required to maintain any 



^ Bell Telephone Laboratories. 



2 American Telephone and Telegraph Company. 



^ Western Electric Company. 



