The original ground electrode of the Madeira River HVDC transmission system, bipole 2, was discarded due to the risk of saturation of the transformers in the Converter Substation of Porto Velho, located 15 km away, during the monopolar operation with ground return. After an extensive geophysical survey, a new site was selected, 40 km from the converter substation. For the confirmation of the new site, it was built in the central area of the site, a single-well 47 m deep test electrode, interconnected to the original 15 km electrode line by an additional 40 km long temporary line. A new electrode was then designed. This paper summarizes the test electrode procedure and the activities developed for the new electrode commissioning after its construction, which can be divided into two phases–pre-commissioning and commissioning. The electrode pre-commissioning was performed before its energization for the evaluation of the integrity of its components. The commissioning tests started with electrode energization, employing the electrode line, and an unbalanced bipole operation, which allowed the evaluation of its electrical performance. However, the main objective of the paper is the evaluation of the electrode resistance, which is an essential HVDC electrode parameter.

The Anthropocene is a proposed geological epoch, generally defined by the significant impacts of human activities on the Earth system. It provides a conceptual framework that traces historical causes, possible futures, and fundamental questions of human responsibility, values and purpose in a changing world. Here, we examine how natural history museums are engaging with the Anthropocene using two novel exhibits as a case study. First, we argue that the museum context, as a social space for learning through a range of embodied sensory experiences, is a valuable medium within which to experience the Anthropocene and communicate about it with a wide audience. Second, we observe that the Anthropocene has conceptual and practical implications for these museums. Thus, we suggest the Anthropocene is an especially productive lens of engagement for natural history museums, catalyzing both development in the science and representation, and also in public comprehension of global change.

The Anthropocene is a multi-faceted concept, which integrates a temporal perspective, highlighting socionatural relationships of the present through the prism of geological time. In so doing, it makes it possible to review the classic perspective of an existential separation between nature and culture. This viewpoint is specific to modern Western societies, and with it the sharing and production of knowledge according to whether it relates to nature (natural sciences) or culture (human and social sciences). By intersecting human and geological time, the Anthropocene brings into play the concept of time taken in a broad sense, where two historical sciences, that of historians and of geologists, come together. The idea of creating a world by distinguishing between time period counted in generations must be reconsidered because geological time includes phenomena whose duration is measured on extremely variable scales and which are always active. Geological time can no longer be simply relegated to a deep time that constitutes a «bedrock» world conceived of as permanent. Rather, it should be considered as consubstantial with a systemic vision, where interrelationships are deployed not only in space – as it is in its common representation – but also in time, in a perpetual contingent movement in which human activities are now inscribed.

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