The reactions of carbon dioxide with complexes

The studies described in this thesis are concerned with the reaction of carbon dioxide and transition metal complexes of Co, Ir, Rh, Ru. Due to the important role of group VIII transition metals in homogeneous catalytic reactions, the work is mainly concerned with complexes of ruthenium.

Chemical reactions at nuclear fuel-clad interfaces

This thesis presents a study of the chemical reactions that may occur at the fuel- clad interfaces of fuel elements used in advanced gas-coooled reactors (A.G.R.) The initial investigation involved a study of the inner surfaces of irradiated stainless steel clad and evidence was obtained to show that fission products, in particular tellerium, were associated with reaction products on these surfaces. An accelerated rate of oxidation was observed on the inner surfaces of a failed A.G.R. fuel pin. It is believed that fission product caesium was responsible for this enhancement. A fundamental study of the reaction between 20%Cr/25%Ni/niobium stabilised stainless steel and tellerium was then undertaken over the range 350 - 850 degrees C. Reaction occurred with increasing rapidity over this range and long term exposure at ≤ 750 degrees resulted in intergranular attack of the stainless steel and chromium depletion. The reaction on unoxidised steel surfaces involved the formation of an initial iron-nickel-tellerium layer which subsequently transformed to a chromium telluride product during continued exposure. The thermodynamic stabilities of the steel tellurides were determined to be chromium telluride > nickel telluride > iron telluride. Oxidation of the stainless steel surface prior to tellerium exposure inhibited the reaction. However reaction did occur in regions where the oxide layer had either cracked or spalled.

Air traffic controller reactions to computer assistance

The research was instigated by the Civil Aviation Authority (CAA) to examine the implications for air traffic controllers' (ATCO) job satisfaction of the possible introduction of systems incorporating computer-assisted decision making. Additional research objectives were to assess the possible costs of reductions in ATCO job satisfaction, and to recommend appropriate task allocation between ATCOs and computer for future systems design (Chapter 1). Following a review of the literature (Chapter 2) it is argued that existing approaches to systems and job design do not allow for a sufficiently early consideration of employee needs and satisfactions in the design of complex systems. The present research develops a methodology for assessing affective reactions to an existing system as a basis for making reommendations for future systems design (Chapter 3). The method required analysis of job content using two techniques: (a) task analysis (Chapter 4.1) and (b) the Job Diagnostic Survey (JDS). ATCOs' affective reactions to the several operational positions on which they work were investigated at three levels of detail: (a) Reactions to positions, obtained by ranking techniques (Chapter 4.2); (b) Reactions to job characteristics, obtained by use of JDS (Chapter 4.3); and (c) Reactions to tasks, obtained by use of Repertory Grid technique (Chapter 4.4). The conclusion is drawn that ATCOs' motivation and satisfaction is greatly dependent on the presence of challenge, often through tasks requiring the use of decision making and other cognitive skills. Results suggest that the introduction of systems incorporating computer-assisted decision making might result in financial penalties for the CAA and significant reductions in job satisfaction for ATCOs. General recommendations are made for allocation of tasks in future systems design (Chapter 5).