ABSTRACTS OF TEC H NIC A L ARTICLES 901 



Plating on Aluminum} R. A. Ehrhardt* and J. M. Guthrie. This 

 article describes tests made to develop a satisfactory process for producing 

 adherent electrodeposits on aluminum alloys using a zincate immersion pre- 

 treatment. 



Since the major interest was the fabrication of aluminum structures by the 

 use of lead-tin solders the adherence of the deposit was determined by meas- 

 uring the strength of soldered joints. 



Excellent results were obtained with commercially pure aluminum and 

 copper bearing alloys and satisfactory results with magnesium and silicon 

 bearing alloys. 



Corrective Networks.^ F. L. Hopper. A type of fully compensated con- 

 stant resistance network is described which provides a larger family of 

 equalization characteristics particularly suited to corrective use in rerecord- 

 ing as determined by aural monitoring. 



Speclrochemical Analysis of Ceramics and Other Non-Metallic Materials.^ 

 Edwin K. Jaycox. The procedure described is applicable to the quanti- 

 tative spectrochemical analysis of ceramics, ashes, ores, paints, and other 

 non-metallic materials for the determination of most of the common metals 

 and their oxides. These include: aluminum, boron, barium, beryllium, cal- 

 cium, copper, chromium, iron, lithium, magnesium, manganese, sodium, 

 lead, silicon, titanium, zinc, and zirconium, in the general range of 0.30-70.0 

 per cent. Samples in the form of a fine powder are mixed one part of sample 

 to 10-100 parts of a suitable metal oxide which serves as a bufiFer, diluent, 

 and internal control. Carbon dust is added to this mixture for its additional 

 buffering effect. Spectra are obtained of the samples and of an appropriate 

 series of standards. Determinations of the amount of element sought are 

 made, in most cases by the well known internal standard technique, in others 

 by the simple comparison standard procedure. 



The Spectrochemical Analysis of Nickel Alloys."^ Edwin K. Jaycox. A 

 procedure is described for the analysis of nickel alloys for copper, iron, lead, 

 magnesium, manganese, silicon, titanium, and zinc in the range 0.005-0.30 

 per cent and for boron in the range 0.0003-0.03 per cent. Samples are taken 

 into solution with dilute nitric acid, evaporated to dryness, and baked at 

 400°C. The resulting dry nitrate-oxide powder is mixed with pure carbon 

 dust which acts as a buffer and diluent. Aliquots of each sample and of a 



^ The Monthly Review, American Electroplaters Society, April 1947. 



* Of Bell Tel. Labs. 



^Jour. Soc. Motion Pic. Engrs., March 1947. 



^ J our. Optical Soc. Amer., March 1947. 



''Jour. Optical Soc. Amer., March 1947. 



