The electrochemistry of lead in sulphuric acid

PhD ThesisThis project was initiated in order to investigate the basic electrochemistry of Pb/PbSO 4 in sulphuric acid. Very little has appeared in the literature on this subjectt workers have been concerned with the PbSO4 /PbO 2 region, as can be seen from the literature survey in Chapter 5. However, in the last few years interest has increased in the lead acid battery and I hope this thesis will help further technical advance. The first four chapters review basic background material against which the measurements were made. The following chapters then describe the experimental work and finally some attempt is made to link the basic electrochemistry to the working of a battery

Giant mud crab (Scylla serrata): relative efficiencies of common baited traps and impacts on discards

This study was initiated in response to a scarcity of data on the efficiency, selectivity and discard mortality of baited traps to target Scylla serrata. Five replicates of four traps, including “hoop nets”, rigid “wire pots”, and collapsible “round” and “rectangular” pots were deployed for 3, 6 and 24 h in two Australian estuaries. Trapped S. serrata were “discarded” into cages and monitored with controls over 3 d. All S. serrata were assessed for damage, while subsets of immediately caught and monitored individuals had haemolymph constituents quantified as stress indices. All traps retained similar-sized (8.1–19.1 cm carapace width) S. serrata, with catches positively correlated to deployment duration. Round pots were the most efficient for S. serrata and fish—mostly Acanthopagrus australis (3% mortality). Hoop nets were the least efficient and were often damaged. No S. serrata died, but 18% were wounded (biased towards hoop nets), typically involving a missing swimmeret. Physiological responses were mild and mostly affected by biological factors. The results validate discarding unwanted S. serrata for controlling exploitation, but larger mesh sizes or escape vents in pots and restrictions on hoop nets would minimise unnecessary catches, pollution and ghost fishing