Effect of Arc-anode Attachment on Thermal Plasma Jet
An interaction of plasma flow with an arc-anode attachment in a dc arc plasma torch was investigated. Statistical processing of the photographic images of plasma jet was used for analysis of an effect of the anode attachment on structure and stability of plasma flow. Deflection, flattening and flutter of the plasma jet was found to be caused by disturbing effect of the arc-anode attachment.
Arc instabilities in a plasma spray torch
The control over coating quality in plasma spraying is partly dependent on the arc and jet instabilities of the plasma torch. Different forms of instabilities have been observed with different effects on the coating quality. We report on an investigation of these instabilities based on high-speed end-on observation of the arc. The framing rate of 40,500 frames per second has allowed the visualization of the anode attachment movement and the determination of the thickness of the cold-gas boundary layer surrounding the arc. The images have been synchronized with voltage traces. Data have been obtained for a range of arc currents, and mass flow rates for different gas injectors and for anodes displaying different amounts of wear. The analysis of the data has led to quantitative correlations between the cold-gas boundary layer thickness and the instability mode for the range of operating parameters. The arc instabilities can be seen to enhance the plasma jet instabilities and the cold-gas entrainment. These results are particularly useful for guiding plasma torch design and operation in minimizing the influence of plasma jet instabilities on coating properties.
Socially responsible enterprise in Cuba: a positive role model for Corporate Social Responsibility?’
This article examines the unique institutional environment of socialist Cuba, where currently a process of controlled marketization and expansion of private enterprise is taking place. The article investigates business behaviour in Cuba with particular reference to implicit assumptions relating to socially responsible enterprise, or Corporate Social Responsibility (CSR) as the term is understood in Western Liberal Democracies. It draws upon a series of interviews with business practitioners and business commentators (both Cuban and non-Cuban residents on the island). The interviews focused on the participants’ awareness of business ethics and socially responsible enterprise, and the cultural differences in assumptions and expectations relating to the concept of CSR between the Cuban and non-Cuban interviewees. We find that Cuba at this early stage of tentative marketization presents a positive role model of socially responsible enterprise. Both the highly regulated State economy and the embedded norms and values of social equity that have emerged as a consequence of Cuba’s socialist revolution facilitate business social responsibility. The relevance of this research to current debates in relation to CSR is discussed and it is argued that capitalist economies may similarly benefit from tighter regulatory control and by cultivating more pro-social business norms that prioritise ethical over economic concerns.