Cutting fluids of various types are usually employed to control the heat generated in machining. The continued application of conventional petroleum based metal working fluids is being challenged by the need to reduce overall volume of fluids, minimize health risks and bio-contamination. Bio-oils assisted machining is an environmental bio-compatible technology for desirable control of temperature. This paper investigates the effect of some vegetable based oils on cutting force during cylindrical machining of mild steel, aluminium and copper. The results indicated that bio oils are suitable for metal working fluids but the effects of the bio-oils on cutting force are material dependent. Groundnut oil exhibited the highest reduction in cutting force when aluminium was being turned at a speed of 8.25m/min and feeds of 0.10, 0.15 and 0.20mm/rev, respectively. Palm kernel oil had the best result when copper was turned at feeds lower than 0.15 mm/rev. However, at higher feeds, groundnut oil had the best result for copper. Coconut oil recorded the highest cutting force in all the three materials machined followed by shear butter and as such are very mild in reducing cutting force during cylindrical machining. It is concluded that groundnut and palm kernel oils are effective in reducing cutting force during cylindrical turning. Though, the lubricating and cooling action is material dependent, groundnut oil is the best among the four bio-oils investigated.

Este artigo utiliza o método descritivo para analisar as origens e o caráter aparentemente intratável, mas evitável, dos fatores ancilares que implicaram a derrocada da Costa do Marfim, que já foi uma ilha de estabilidade política, uma vitrine de prosperidade econômica e de sucesso em uma África Ocidental mergulhada em guerras civis. O artigo investiga as políticas dos Estados colonial e pós-colonial até a morte do presidente Félix Houphouët-Boigny, a era pós-Houphouët e suas crises política e socioeconômica, e a má administração do legado de Boigny, que levaram ao conflito interno. As conseqüências da disputa interna também são investigadas nos níveis nacional e sub-regional, assim como as resoluções dos conflitos por meio das ineficientes iniciativas de paz de Accra que, inexoravelmente, levariam às conversas de paz de Lina-Marcoussis. Os resultados das negociações, a participação de poderes não africanos e o futuro da democracia na Costa do Marfim também são investigados.

This paper uses descriptive method to analyse the origin and the seemingly intractable but avoidable ancillary factors that plunged Côte d'Ivoire, which was once the island of political stability, the showcase of economic prosperity and success in West Africa in the fangs of civil war. The paper surveys the policies of the colonial and postcolonial state till the death of President Félix Houphouët-Boigny, the post-Houphouët era and its lot of political and socio-economic upheavals and the mismanagement of the legacies of Boigny that led to the internal conflict. The consequences of the civil strife are also surveyed at the national and sub-regional levels as well as the resolutions of the conflict through the botched Accra peace initiatives that inexorably led to the Lina-Marcoussis peace talks. The aftermath of the negotiations and the involvement of extra-African powers and the future of democracy in Côte d'Ivoire are also looked into.