Maddock

T. J. McGieehan andj. T. Maddock, M Studj of Flame Retardantsfor Textiles, Report No. PB 251-441/AS, National Information Service, Springfield, Va., 1976. 

FIG. 18-48 Mixing enhancers for single-screw extruders a) Maddock (straight), (h) Maddock (tapered), (c) pineapple, (d) gear, (e) pin,... 

As the parent of actinium in this series it was named protoactinium, shortened in 1949 to protactinium. Because of its low natural abundance its chemistry was obscure until 1960 when A. G. Maddock and co-workers at the UK Atomic Energy Authority worked up about 130g from 60 tons of sludge which had accumulated during the extraction of uranium from UO2 ores. It is from this sample, distributed to numerous laboratories throughout the world, that the bulk of our knowledge of the element s chemistry was gleaned. 

Studies of metal alkyls and aryls deal largely with arsenic, germanium and antimony, although some work has also been done on tellurium, mercury, thallium, bismuth and lead. The major contributions can be neatly divided into four periods early studies by Maddock, Sutin and H 1155).56).57) studies by the Polish >- >- and the Strasbourg >- 2).79) groups, work by Riedel and and most recently a series... 

An isotope effect seen in Sb03 by Maddock and Sutin was studied by Hall and Sutin , whose results are shown in Table 3. Again, phenyl radicals were cited as the likely means of reforming the bonds. It was pointed out that owing to the occurrence of isomeric transitions in both of these antimony isotopes, differences in the conversion coefficients could lead to the isotopic differences. 

Fig. 1. Annealing curves (45 °C) for several products in neutron irradiated triphenylarsine. Note particularly the initial rise and subsequent fall of diphenylarsine derivatives (Redrawn from Maddock and Sutin )...

Not many organometallic systems have been subjected to extensive thermal annealing studies— the most thorough work has been done on the phenylarsenic compounds. The earliest such study was that of Maddock and Sutin on triphenylarsine. The results are in part given in Fig. 1, from which it was concluded that the reformation progresses in the stepwise fashion ... 

Maddock, S.W. Semple, J.T. (1986). Field assessment of somaclonal variation in wheat. Journal of Experimental Botany, 37, 1114-28. 

Maddock and Sutin (56) observed the formation of numerous oxygenated products in neutron-irradiated AsPhj which, they argued, must have come from reaction of AsPh radicals with oxygen or water during the separation. The annealing effect of heating at 45° led to increased yields of AsPhj, while AsPhj products first increased and then decreased. This was interpreted as showing the involvement of phenyl radicals in a series of consecutive reactions ... 

Maddock, J.E.L. and Tomlinson, E.J., The clarification of effluent from an activated sludge plant using dissolved air flotation, Water Pollution Control, 85 (1), 114-127, 1980. 

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