Search results

The purpose of this study is to evaluate the efficiency of a Brazilian steelmaking company’s reheating process of the hot rolling mill.

The research method is a quantitative modeling. The main research techniques are data envelopment analysis, TOBIT regression and simulation supported by artificial neural networks. The model’s input and output variables consist of the average billet weight, number of billets processed in a batch, gas consumption, thermal efficiency, backlog and production yield within a specific period. The analysis spans 20 months.

The key findings include an average current efficiency of 81%, identification of influential variables (average billet weight, billet count and gas consumption) and simulated analysis. Among the simulated scenarios, the most promising achieved an average efficiency of 95% through increased equipment availability and billet size.

Additional favorable simulated scenarios entail the utilization of higher pre-reheating temperatures for cold billets, representing a large amount of savings in gas consumption and a reduction in CO2 emissions.

This study’s primary innovation lies in providing steelmaking practitioners with a systematic approach to evaluating and enhancing the efficiency of reheating processes.

Brazilian federalism was important in the political game of combating the pandemic for three reasons. First, Brazil's public health system depends heavily on intergovernmental relations between Union, states, and municipalities because there is a policy portfolio based on federative cooperation. Second, the subnational governments' autonomy to act against COVID-19 was constantly questioned by the Federal Government – the conflict between the President and governors was a key piece in all health policy. Finally, states and local governments were primarily responsible for policies to fight against pandemic, but the absence and/or wrong measures taken by the Federal Government (such as the delay in purchasing vaccines) generated intergovernmental incoordination, increased territorial inequality, and reduced the effectiveness of subnational public policies, especially those linked to social isolation. In this context, Brazilian federalism played a dual role in the pandemic. On the one hand, the federative structure partially succeeded in averting an even worse scenario, mitigating the impact of mistaken presidential decisions. The role of subnational governments, especially of the states, was critical as a counterweight to federal decisions. On the other hand, the President actively acted against governors and mayors and, above all, sought to weaken intergovernmental articulations within the Unified Health System (SUS), the federative model designed three decades ago. One could say that the federative actors, such as the Supreme Court (Supremo Tribunal Federal – STF) and subnational governments, were the main obstacles for the Bolsonarist antiscientific agenda. The success of this reaction to President Bolsonaro's negationist populism was partial, but the results of the fight against COVID-19 would have been much worse without these federalist barriers.