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Abstract With the growing demand for solutions to prevent and resolve faults in gas-insulated substations that affect the operation of the electrical system, a fault simulation laboratory for gas-insulated substations was developed to develop solutions for monitoring and locating these faults. The laboratory is composed of instruments for a fault location system based on traveling wave theory. The laboratory also has computational programs for fault simulation control and signal acquisition, in addition to having tools to analyze the data. The results were obtained through tests carried out that confirmed the laboratory's ability to simulate the operation of faults in gas-insulated substations, which allowed demonstrating the capacity of the fault location system using the theory of traveling waves.

Abstract Shielded substations with SF6 gas insulation (GIS) play a critical role in supplying power to urban areas, and it is crucial to quickly identify and isolate faults to restore system operation and meet supply demands. However, locating faults in such substations can involve extensive and time-consuming procedures, such as opening and closing hermetically sealed compartments containing SF6. This paper presents the development of an acoustic test bench that accurately replicates the dynamic characteristics of SF6 shielded substations. By utilizing the traveling wave technique, partial discharges occurring in high-voltage insulation can be detected and precisely located. The method employs various techniques, including the analysis of the arrival time of traveling waves at different points within the substation and triangulation methods. The use of traveling waves in partial discharge detection offers several advantages, such as precise fault location and non-interference with normal substation operations. Additionally, acoustic methods are highly sensitive to other sources of partial discharges, such as moving particles and fluctuating potential discharges. The results demonstrate that the combination of the acoustic test bench and the disturbance localization technique presents an innovative approach to fault location studies in GIS. The acoustic test bench enables controlled simulation of failure conditions, providing accurate data on the acoustic behavior of substations. Through the disturbance location technique, these data can be analyzed and interpreted to pinpoint the exact fault location. This integrated approach enhances the efficiency of the troubleshooting process and reduces the time required to repair GIS.

Parasitoid larvae consume their hosts to obtain the nutritional resources required for their development. Parasitoid wasps can optimally select the size of their hosts by laying unfertilized and fertilized eggs according to the amount of biomass available for consumption by the larvae. However, parasitoids may eventually experience low host availability within the optimal range of body sizes, affecting the survival of their offspring. In this study, we identified a situation in which all available hosts (Leucauge volupis) were smaller than those previously observed to be parasitized by Hymenoepimecis pinheirensis at the same study site. Therefore, we investigated how these parasitoids can bypass the scarcity of ideal hosts. Female wasps biased their oviposition toward the largest L. volupis females available. In this suboptimal scenario, they did not oviposit only unfertilized eggs, which developed into relatively small offspring (males). In this situation, they lay fertilized eggs mainly on larger spiders. Larval mortality was high, but the larvae attached to the larger spiders were more likely to complete their development. In general, H. pinheirensis females managed to target the best hosts available but could not delay the oviposition of fertilized eggs or avoid offspring mortality. Here, we discuss the potential causes of asynchronies in the life cycles of parasitoid wasps and their hosts, the availability of optimal hosts, and how these factors may affect their populations. [ABSTRACT FROM AUTHOR]

Abstract The continuity of an electrical system's services is linked to its equipment's correct operation. The more correctly they worked, the higher the quality of the services provided. Thus, they must have their functioning scanned closely and that minor defects have their evolution monitored. This fact creates the possibility of making predictions about how long equipment can operate without compromising the system's continuity. This follow-up is proper for predictive maintenance. This paper presents three on-going COPEL Generation and Transmission projects in essential elements of its electrical system: circuit breakers, lightning arresters, and SF6 substation. The central idea of all monitoring projects is to check the early problem in this equipment and facilities.

Species that differ in their social system, and thus in traits such as group size and dispersal timing, may differ in their use of resources along spatial, temporal, or dietary dimensions. The role of sociality in creating differences in habitat use is best explored by studying closely related species or socially polymorphic species that differ in their social system, but share a common environment. Here we investigate whether five sympatric Anelosimus spider species that range from nearly solitary to highly social differ in their use of space and in their phenology as a function of their social system. By studying these species in Serra do Japi, Brazil, we find that the more social species, which form larger, longer-lived colonies, tend to live inside the forest, where sturdier, longer lasting vegetation is likely to offer better support for their nests. The less social species, which form single-family groups, in contrast, tend to occur on the forest edge where the vegetation is less robust. Within these two microhabitats, species with longer-lived colonies tend to occupy the potentially more stable positions closer to the core of the plants, while those with smaller and shorter-lived colonies build their nests towards the branch tips. The species further separate in their use of common habitat due to differences in the timing of their reproductive season. These patterns of habitat use suggest that the degree of sociality can enable otherwise similar species to differ from one another in ways that may facilitate their co-occurrence in a shared environment, a possibility that deserves further consideration.

Individual specialization (IS) in resource use is common within populations of several animal species because some individuals can be more efficient than others in obtaining specific food items. Spiders are usually classified as euryphagous predators, but the broad diet of populations may result from many individuals specializing in capturing different types of prey. Empirical evidence supporting this pattern, however, is still scarce. In this study, we hypothesized that (1) the diet of individuals of Tidarren haemorrhoidale is more restricted than the population's diet and (2) individual diet restrictions are not determined by the spatial distribution of prey types. We collected the prey remains of 74 webs of females in a conservation area of the Atlantic Forest. Our results indicated that T. haemorrhoidale could be considered a euryphagous predator because its diet comprised Opiliones, Diplopoda, and eight orders of insects. However, spiders exhibited moderate and high degrees of IS for prey size and taxa, respectively. There was no modularity for both prey attributes in the food web, but there was a medium nestedness. Most individuals captured ants, but additional prey taxa were of different orders. There was no correlation between the dissimilarity of prey taxa and the distances between the webs, suggesting that IS did not occur based on the spatial distribution of their potential prey. The diversity of prey defensive strategies may induce spiders to perform specific behavioral routines after prey interception. If this occurs, cognitive constraints may limit their ability to use different capture routines efficiently. Our study supports the predictions of individual niche specialization theory for a euryphagous spider species and highlights the potential of spiders as a study model to investigate the underlying mechanisms. [ABSTRACT FROM AUTHOR]

The expressions of parental care can vary in space and time because factors driving offspring mortality depend on variable abiotic and biotic conditions. Manogea porracea is a spider that exhibits biparental care and widespread distribution in the Neotropical region. Parents can protect their offspring against abiotic conditions that may damage their webs, or compromise their egg sacs, and against araneophagic spiders that prey on their eggs. However, the current knowledge of the parental care in the species is restricted to a population located in areas covered by Eucalyptus plantations. This study investigates parental care efficiency in a new ecological context, a protected area of Brazilian savanna. We described the substrates in which M. porracea built webs and the agents of egg mortality. We also performed a parent removal experiment to test the effect of parental care on the integrity of nursery webs, offspring survival, and the presence of egg predators. Spiders built webs at variable heights and many distinct substrates but were mainly associated with the bromeliad Ananas ananassoides. We found two previously reported egg predators, Faiditus caudatus and Argyrodes elevatus (Araneae Theridiidae), and a new one emerging from the egg sacs, the insect Zeugomantispa virescens (Neuroptera Mantispidae). The presence of parents in the webs of M. porracea prevented the webs from collapsing and effectively increased offspring survival. However, the occurrence of egg predators was not reduced by the presence of parents. Overall, parental care increased offspring survival in both populations, but variation in biotic and abiotic factors between areas influenced offspring mortality and the efficiency of parental behaviours. Our results emphasise the importance of investigating multiple populations in behavioural studies of parental care. We investigated the efficiency of parental care of the spider M. porracea in a protected area of Brazilian savanna. Parents were efficient in increasing offspring survival and their presence assured the integrity of most nursery webs. Egg predators were found in webs regardless of the presence of parents and we registered for the first time the insect Zeugomantispa virescens within egg sacs. We discuss the implications of population variation for the ecology and evolution of parental care efficiency in M. porracea. [ABSTRACT FROM AUTHOR]

O objetivo desse trabalho é relatar as experiências do PIBID Biologia (IF Goiano – Câmpus Urutaí), com destaque para as ações realizadas no Subprojeto de Ciências Biológicas; a visão dos supervisores bolsistas acerca da atuação e contribuição do programa na escola conveniada e na formação docente dos licenciandos; bem como a visão dos alunos bolsistas acerca da importância do subprojeto. Para a realização desse trabalho foi utilizada uma metodologia descritiva analítica, por meio da qual as atividades desenvolvidas foram relatadas de forma crítica e reflexiva. O Subprojeto de Ciências Biológicas (PIBID/IF Goiano – Câmpus Urutaí) atualmente conta com 15 alunos bolsistas e 3 professores supervisores do Colégio Estadual Professor Ivan Ferreira (CEPIF), Pires do Rio, GO. De modo geral, pode-se dizer que as atividades desenvolvidas têm atingindo positivamente não apenas os alunos bolsistas, mas também a melhoria de aspectos diversos ligados ao ensino de Biologia na escola conveniada. O PIBID-Biologia tem possibilitado aos seus bolsistas uma aproximação de sua futura atuação profissional.