Aluminium 100% efficiency

The ester and catalj st are usually employed in equimoleciilar amounts. With R =CjHs (phenyl propionate), the products are o- and p-propiophenol with R = CH3 (phenyl acetate), o- and p-hydroxyacetophenone are formed. The nature of the product is influenced by the structure of the ester, by the temperature, the solvent and the amount of aluminium chloride used generally, low reaction temperatures favour the formation of p-hydroxy ketones. It is usually possible to separate the two hydroxy ketones by fractional distillation under diminished pressure through an efficient fractionating column or by steam distillation the ortho compounds, being chelated, are more volatile in steam It may be mentioned that Clemmensen reduction (compare Section IV,6) of the hj droxy ketones affords an excellent route to the substituted phenols. 

Presented approach enables an efficient approach to the choice of the proper calibration cur ve, having two terms. Method was tested on big amount of standar ds of brass, bronze and aluminium alloys. 

Experimental values for tire sputtering efficiency tend to show lower values of a for elements, such as aluminium and mngsten which form stable oxides, compared with the metals such as gold and platinum which do not under normal experimental conditions. This is probably due to the presence of a surface oxide, since industrial sources of argon, which are used as a source of ions for example, usually contain at least 1 ppm of oxygen, which is more than enough to oxidize aluminium and tungsten. 

Several high-efficiency hard chromium plating baths are now available commercially. A solution which does not contain fluoride, and does not therefore attack steel or aluminium, has been described by Schwartz . At 50 A/dm and 53°C the cathode efficiency is about 25%, enabling deposition to be carried out at the rate of I m/min, with a consequent substantial saving in power and time. The deposit is bright, and has a hardness of about 1 050 Hy. 

J. P. Boudot, Relative efficiency of complexed aluminium, non-crystalline A1 hy-droxyde, allophane and imogolite in retarding the biodegradation of citric acid. Geoderma 52 29 (1992). 

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