No description available.

No description available.

No description available.

No description available.

The present work represents an attempt to study the inhibition of corrosion of mild steel in acid media by seventeen furan derivatives, at 17 to 30 different inhibitor concentrations, from 0 up to 20 mMole per liter. / One of the techniques used to correlate the inhibitive action of organic compounds is based on the Linear Free Energy Relationship (LFER). The relationship is used to elucidate the mechanism of inhibition, by studying the effects of physico-chemical characteristics of the inhibitor molecules, such as functional group, polar function electron density, steric effects, and (pi)-orbital character of the donating electrons on the corrosion inhibition of mild steel in acid solution. / The results show that furfuryl alcohol, 2,5-furan dimethanol, and 2-furonitrile act as excellent inhibitors over the entire concentration range covered in this study, whereas the remaining investigated compounds exhibit substantial fluctuations in the inhibitive action with concentration. Frequent maxima and minima of inhibitive action have been observed. This behaviour can be explained on the basis of the different reaction mechanisms of the absorbed intermediate inhibitor complex at the metal surface. / The results of the study suggest that the inhibitive action of ortho-substituted compounds is influenced by steric effect. Although LFER is a valuable tool for comparing inhibitive actions of various compounds, other criteria should be considered. These criterion or special effects include polymerization, (pi)-orbital electrondelocalization, and mesomeric effects. Such effects could cause a compound to act as a good inhibitor, irrespective of considerations relating to electron affinity.

The effect of acetylene (C(,2)H(,2)) on nitrifying microorganisms and the production of nitrous oxide (N(,2)O) by the ammonia-oxidizing chemoautotroph Nitrosomonas europaea was measured in culture medium and in sterilized soil. / Acetylene strongly inhibited (K(,i) 0.66 Pa) the oxidation of NH(,4)('+) to hydroxylamine (NH(,2)OH) but not of NH(,2)OH to nitrite (NO(,2)('-)) by N. europaea. The oxidation of NH(,4)('+) to NH(,2)OH and NO(,3)('-) by the heterotrophic nitrifier, Arthrobacter sp. was not affected by C(,2)H(,2) (10 kPa). / Observed patterns of N(,2)O production by N. europaea in the presence of various combinations of NH(,4)('+), NO(,2)('-), C(,2)H(,2) and oxygen (O(,2)) supported earlier published suggestions that N(,2)O may be formed via an oxidative route from NH(,4)('+) and (or) NH(,2)OH, or via a reductive route from NO(,2)('-). The former process was O(,2)-dependent and inhibited by C(,2)H(,2), while the latter process was inhibited by O(,2) but not by C(,2)H(,2). / Sodium chlorate (NaClO(,3), 10 mM) inhibited the oxidation of both NH(,4)('+) and NO(,2)('-) in dual axenic suspensions of N. europaea and Nitrobacter winogradskyi. N. winogradskyi reduced ClO(,3)('-) to ClO(,2)('-) under both aerobic and anaerobic conditions. Evidence is presented which suggests that NH(,4)('+) oxidation is inhibited by the ClO(,2)('-) so produced.

Typescript (photocopy) / iv, 201 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Organic Chemistry, University of Adelaide, 1981

Thesis (Ph.D.) Dept. of Organic Chemistry, University of Adelaide, 1981. / Typescript (photocopy).

Thesis (Ph.D.)--Baylor University, 2008. / Includes bibliographical references (p. 361-367).

Thesis (Ph.D.)--Baylor University, 2008. / In abstract the '50' in IC50 is subscript. Includes bibliographical references (p. 349-357).