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Temperature monitoring is an important procedure to control the composting process. Due to cost limitation, temperature monitoring is manual and with daily sampling resolution. The objective of this study was to develop an automatic station with US$ 150 dollars, able to monitor air temperature at two different points in a compost pile, with a 5-min time resolution. In the calibration test, the sensors showed an estimated uncertainty from ± 1 to ± 1.9 ºC. In the field validation test, the station guaranteed secure autonomy for seven days and endured high humidity and extreme temperature (> 70 °C).

Motivated by growing concerns about the environment and the rising price of fossil fuels in recent years, many countries have started to diversify their energy sources, opting for renewables whenever feasible. Brazil, a country with a predominance of hydroelectric generation, has also experienced a greater participation of other renewable sources, such as wind, solar and biomass. However, even though they contribute for a lower dependence on water and fossil fuels for energy generation, their intermittence lead to an increase of operational complexity and may threaten the country’s energy security. As an emerging economy with growing energy needs, the challenge now in Brazil is to identify ways to ensure efficient energy supply, compatible with demand and mindful of environmental issues. In this context, this work presents a compilation of the main studies and surveys related to Pumped Hydroelectric Energy Storage (PHES), while seeking to contribute in finding ways to reduce the unpredictability of renewable sources generation. Furthermore, the aim is to increase energy security in times of drought, especially when the inter-regional, seasonal and multimodal complementarity of energy generation in Brazil fails to avoid energy deficits. The methodology used draws upon a bibliographical review of the current PHES scenarios in Brazil and in the world. Advantages and opportunities of this type of energy storage are assessed at the national level, together with a presentation of the challenges faced by the implementation of this model in Brazil. Finally, we discuss the main challenges and present some suggestions for future work on this subject. A post-publication change was made to this article on 3 Jul 2020 to correct an author name.

This paper proposes a confluence between soft OR and soft computing methods. by means of an application of firzzy logic ideas to robustness analysis. Both methods try to add flexibility to proposed solutions of real world problems, although insofar as their application contexts is concerned, they have been quite apart. So it is only natural to bring them together in what could be called a "jkification" of robustness analysis. A f~rst step in thatdirection is attempted in this paper.

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