2 resultados para arc welding
em CORA - Cork Open Research Archive - University College Cork - Ireland
Resumo:
This paper compares continuity and change in homelessness policy in Ireland, Scotland and Norway with a particular focus on the period of post-crisis austerity measures (2008-2016). The analytical approach draws on institutional theory and the notion of path dependency, which has rarely been applied to comparative homelessness research. The paper compares welfare and housing systems in the three countries prior to presenting a detailed analysis of the conceptualisation and measurement of homelessness; the institutions which address homelessness; and the evidence of change in the post-2008 period. The analysis demonstrates that challenges remain in comparing the nature of homelessness and policy responses across nation states, even where they have a number of similar characteristics, and despite some EU influence towards homelessness policy convergence. Similarly, national-level homelessness policy change could not be interpreted as entirely a result of the external shock of the 2008 general financial crisis, as existing national policy goals and programmes were also influential. Overall, embedded national frameworks and institutions were resilient, but sufficiently flexible to deliver longer term policy shifts in response to the changing nature of the homelessness problem and national policy goals. Institutionalism and path dependency were found to be useful in developing the comparative analysis of homelessness policy change and could be fruitfully applied in future longitudinal, empirical research across a wider range of countries.
Resumo:
TiSiC-Cr coatings, with Cr and Si as additional elements, were deposited on Si, C 45 and 316 L steel substrates via cathodic arc evaporation. Two series of coatings with thicknesses in the range of 3.6–3.9 μm were produced, using either CH4 or C2H2 as carbon containing gas. For each series, different coatings were prepared by varying the carbon rich gas flow rate between 90 and 130 sccm, while maintaining constant cathode currents (110 and 100 A at TiSi and Cr cathodes, respectively), substrate bias (–200 V) and substrate temperature (∼320 °C). The coatings were analyzed for their mechanical characteristics (hardness, adhesion) and tribological performance (friction, wear), along with their elemental and phase composition, chemical bonds, crystalline structure and cross-sectional morphology. The coatings were found to be formed with nano-scale composite structures consisting of carbide crystallites (grain size of 3.1–8.2 nm) and amorphous hydrogenated carbon. The experimental results showed significant differences between the two coating series, where the films formed from C2H2 exhibited markedly superior characteristics in terms of microstructure, morphology, hardness, friction behaviour and wear resistance. For the coatings prepared using CH4, the measured values of crystallite size, hardness, friction coefficient and wear rate were in the ranges of 7.2–8.2 nm, 26–30 GPa, 0.3–0.4 and 2.1–4.8 × 10−6 mm3 N−1 m−1, respectively, while for the coatings grown in C2H2, the values of these characteristics were found to be in the ranges of 3.1–3.7 nm, 41–45 GPa, 0.1–0.2 and 1.4–3.0 × 10−6 mm3 N−1 m−1, respectively. Among the investigated coatings, the one produced using C2H2 at the highest flow rate (130 sccm) exhibited the highest hardness (45.1 GPa), the lowest friction coefficient (0.10) and the best wear resistance (wear rate of 1.4 × 10−6 mm3 N−1 m−1).