Applied financial improvement planning in local governments: The case of Kitwe City Council, Zambia

The trend toward decentralisation continues, albeit unevenly, in most developing countries. Increasing decentralisation places considerable pressure on local government to manage a wider range of functions and services and to manage larger budgets, while continuing urbanisation increases both geographic and demographic service areas of local governments. In this context, sound financial management by local governments is becoming increasingly important. It is likely that the need to undertake financial improvement planning in local governments will grow both for those local governments wishing to generally improve or ‘fine-tune’ their financial performance, and especially for those local governments facing more serious financial difficulties. Several approaches have been developed for undertaking financial improvement planning in local governments

The development of aluminium-zinc-magnesium alloys for superior stress corrosion resistance

Thesis (M.Sc.(Engineering))--University of the Witwatersrand, Faculty of Engineering, Department of Metallurgy, 1983.A thorough literature survey has been undertaken to provide the necessary understanding of: i) the general metallurgy and microstructure of Al-Zn-Mg alloys, ii) the stress corrosion cracking (SCC) of Al-Zn-Mg alloys (including accelerated SCC test methods), and iii) the influence of composition, microstructure and heat treatment on SCC properties. Three accelerated SCC test methods were evaluated using existing commercial alloys in different temper conditions. These were the notched rod load relaxation, the electrochemical acceleration and the slow strain rate SCC tests. The slow strain rate method gave the most reliable and reproducible results. This was therefore chosen for all subsequent testing. Baseline SCC test data was obtained from existing alloys in order to facilitate comparison of new alloy compositions * The microstructure of a representative Al-Zn-Mg alloy was examined using optical, scanning and transmission electron microscopy. The effects of quench rate from solution heat treatment, and ageing time and temperature on both the microstructure and SCC properties were investigated. Decreasing quench rate produced a moderate increase in resistance to SCC. The characteristic increase in resistance to SCC found by overageing was, however, associated with an unacceptable loss of mechanical properties, ABSTRACT A thorough literature survey has been undertaken to provide the necessary understanding of: i) the general metallurgy and microstructure of Al-Zn-Mg alloys, ii) the stress corrosion cracking (SCC) of Al-Zn-Mg alloys (including accelerated SCC test methods), and iii) the influence of composition, raicrostructure and heat treatment on SCC properties. Three accelerated SCC test methods were evaluated using existing commercial alloys in different temper conditions. These were the notched rod load relaxation, the electrochemical acceleration and the slow strain rate SCC tests. The slow strain rate method gave the most reliable and reproducible results. This was therefore chosen for all subsequent testing. Baseline SCC test data was obtained from existing alloys in order to facilitate comparison of new alloy compositions.. The raicrostructure of a representative Al-Zn-Mg alloy was examined using optical, scanning and transmission electron microscopy. The effects of quench rate from solution heat treatment, and ageing time and temperature on both the raicrostructure and SCC properties were investigated. Decreasing quench rate produced a moderate increase in resistance to SCC. The characteristic increase in resistance to SCC found by overageing was, however, associated with an unacceptable loss of mechanical properties. Melting, casting and hot working techniques were developed in order to fabricate defect-free small scale experimental alloy compositions. Seven experimental casts were made to cover a wide compositional variation {2n:4~6 wt*t, and Mg:0.8-2.5 wt.%). Slow strain rate SCC testing revealed the beneficial effects of having a zn:Mg ratio of 3:1 (wt.%)

Asymmetric Silver to Oxide Adhesion in Multilayers Deposited on Glass by Sputtering

We have developed a wedge-loaded double-cantilever beam adhesion measurement set-up for thin films deposited on glass by sputtering. The test is described in details. Results on the Glass/sublayer/Ag/ZnO multilayer provide evidence that \SnOd or \TiOd perform better than ZnO as a sublayer. Then however, rupture within the multilayer shifts to the upper Ag/ZnO interface. The latter is shown to be tougher than the lower ZnO/Ag interface, an asymmetry due to non-equilibrium interfacial structures

A catalytic alloy approach for graphene on epitaxial SiC on silicon wafers

© Materials Research Society 2015. We introduce a novel approach to the synthesis of high-quality and highly uniform few-layer graphene on silicon wafers, based on solid source growth from epitaxial 3C-SiC films. Using a Ni/Cu catalytic alloy, we obtain a transfer-free bilayer graphene directly on Si(100) wafers, at temperatures potentially compatible with conventional semiconductor processing. The graphene covers uniformly a 2″ silicon wafer, with a Raman ID/IG band ratio as low as 0.5, indicative of a low defectivity material. The sheet resistance of the graphene is as low as 25 Ω/square, and its adhesion energy to the underlying substrate is substantially higher than transferred graphene. This work opens the avenue for the true wafer-level fabrication of microdevices comprising graphene functional layers. Specifically, we suggest that exceptional conduction qualifies this graphene as a metal replacement for MEMS and advanced on-chip interconnects with ultimate scalability

Cyclic fatigue effect in particulate ceramic composites

A new model is presented that provides an improved understanding of the time dependent fatigue behavior of two phase brittle particulate ceramic composites under static and cyclic loading conditions. The proposed model takes into consideration cyclic fatigue effects, which are responsible for the accelerated fatigue crack propagation in the cyclic loading as compared to the static loading. It also takes into account the effect of both thermal residual stresses and bridging stresses acting in the composite during time dependent crack propagation. Experimental results for the fatigue behavior of ZrB2–45 vol%SiC ceramic composite were used as a case study to valid the proposed model. The model gives insight both into the time dependent mechanical behavior of ceramic composites and, at the same time, allows determination of important structural parameter, such as, size of the bridging zone in the material under cycling loading

Size Effect in Fracture: Roughening of Crack Surfaces and Asymptotic Analysis

Recently the scaling laws describing the roughness development of fracture surfaces was proposed to be related to the macroscopic elastic energy released during crack propagation [Mor00]. On this basis, an energy-based asymptotic analysis allows to extend the link to the nominal strength of structures. We show that a Family-Vicsek scaling leads to the classical size effect of linear elastic fracture mechanics. On the contrary, in the case of an anomalous scaling, there is a smooth transition from the case of no size effect, for small structure sizes, to a power law size effect which appears weaker than the linear elastic fracture mechanics one, in the case of large sizes. This prediction is confirmed by fracture experiments on wood.Comment: 9 pages, 6 figures, accepted for publication in Physical Review

Fatigue of Yttria-Stabilized Zirconia: II, Crack Propagation, Fatigue Striations, and Short-Crack Behavior

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65604/1/j.1151-2916.1991.tb04089.x.pd