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 Surge arresters are at the forefront of protection against voltage surges. The loss of the protective effect of surge arresters imposes accidents and unplanned shutdowns on the power system. It directly affects the interruption of power supplies and imposes fines on service providers. Monitoring and diagnostics in the lightning rod field require studies and work that present the degradation behaviour of surge arresters to help develop and improve existing techniques. This paper presents the development of a laboratory with a low-energy, mobile current waveform impulse generator. It allows for conducting aging tests by applying discharges to low-voltage zinc oxide surge arresters used in the energy distribution sector. Samples of surge arresters were subjected to the discharges produced by the developed generator, and they exhibited degradation, thus showing asymmetry between the positive and negative half-cycles of leakage current.

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.

Abstract The presented development is an intelligent diagnostic system for transformers that studied machine learning techniques to determine the operational status of these transformers. The study of these techniques is initiated by observing the quantities that define the operational behavior of large transformers, aiming to identify anomalies in their operation from data from sensors that equipment it in the functioning environment. This large power transformer has a theoretical service life of above 20 years and a low failure rate. Thus, obtaining failure values, which have their evolution monitored for large transformers, is almost nil. Therefore, a supervised machine training methodology to diagnose these cases is practically unfeasible. The study carried out with several traditional intelligent techniques can verify this. Several supervised methods (Closest Neighbor K-th Neighbor, Support Vector Machine, Radial Base Function, Decision Trees, Random Forest, Neural Network, AdaBoost, Gaussian Naive Bayes, and Quadratic Discriminant Analysis) were studied.

Abstract As high-voltage circuit breakers (HVCBs) are responsible for switching off the load in the event of anomalies, they suffer various wear and tear, both on their main contacts and on the other actuation mechanisms. Not only load maneuvers but also weather conditions can bring factors that contribute to deterioration and, consequently, contribute to failures of this component that is so important for energy supply. Both failures and maintenance shutdowns generate costs for substations, something that could be minimized if there was monitoring of the condition of the HVCBs. This paper shows a methodology to analyze the vibration signal of HVCB in order to identify and quantify contact failures. The proposed methodology is verified through an experimental setup. The results show that it is possible not only to identify the fault but also to assess its intensity using vibration analysis.

Abstract: Background and Aims: Ricciocarpos natans is one of the few species of truly aquatic hepatics. It has a subcosmopolitan distribution and appears to be more common in temperate areas. The species has been considered to be very rare in Central America where it was known only from Panama. The objective of this study is to report the presence of this species in Costa Rica and to survey its current distribution in Latin America. Methods: We provide an overview of the distribution of the floating aquatic liverwort Ricciocarpos natans in Latin America based on literature, herbarium specimens and unequivocal photographic records across the region, as well as field work in Costa Rica. Key results: Ricciocarpos natans is reported as new for Costa Rica. We provide the most complete survey to date of the geographic distribution of the species in Latin America. Conclusions: Our survey shows that Ricciocarpos natans appears to be more common and widely distributed in the Neotropics than previously assumed. Its assumed rarity seems to be the result of insufficient collection efforts.

Resumen: Antecedentes y Objetivos: Ricciocarpos natans es una de las pocas especies de hepáticas verdaderamente acuáticas. Tiene una distribución subcosmopolita y parece ser más común en áreas templadas. La especie ha sido considerada muy rara en América Central, donde solo se conocía de Panamá. El objetivo de este estudio es reportar la presencia de esta especie en Costa Rica y revisar su distribución en América Latina. Métodos: Brindamos una descripción general de la distribución de la hepática acuática flotante Ricciocarpos natans en América Latina con base en la literatura, especímenes de herbario y registros fotográficos inequívocos en toda la región, así como trabajo de campo en Costa Rica. Resultados clave: Ricciocarpos natans se reporta como nueva para Costa Rica. Brindamos el estudio más completo hasta la fecha de la distribución geográfica de la especie en América Latina. Conclusiones: Nuestro estudio muestra que Ricciocarpos natans parece ser más común y más ampliamente distribuida en el Neotrópico de lo que se suponía anteriormente. Su supuesta rareza parece ser el resultado de esfuerzos de recolección insuficientes.

Abstract Objective: To evaluate idiopathic musculoskeletal pain, musculoskeletal pain syndromes, and use of electronic devices in adolescents with asthma and healthy controls. Methods: Cross-sectional study was conducted on 150 asthmatic adolescents and 300 controls. Adolescents completed a self-administered questionnaire regarding painful symptoms, use of electronic devices, and physical activity. Seven musculoskeletal pain syndromes were evaluated, and Asthma Control Test (ACT) was assessed. Results: Musculoskeletal pain (42% vs. 61%, p = 0.0002) and musculoskeletal pain syndromes (2.7% vs. 15.7%, p = 0.0006) were significantly lower in asthmatic adolescents than in controls. The frequency of pain in the hands and wrists was reduced in asthmatic than in controls (12.6% vs. 31.1%, p = 0.004), in addition to cell phone use (80% vs. 93%, p < 0.0001), simultaneous use of at least two electronic media (47% vs. 91%, p < 0.0001), myofascial syndrome (0% vs. 7.1%, p = 0.043), and tendinitis (0% vs. 9.2%, p = 0.008). Logistic regression analysis, including asthma with musculoskeletal pain as the dependent variable, and female sex, ACT > 20, simultaneous use of at least two electronic devices, cell phone use, and weekends and weekdays of cell phone use, as independent variables, showed that female sex (odds ratio [OR], 2.06; 95% confidence interval [CI], 1.929–6.316; p = 0.0009) and ACT ≥ 20 (OR, 0.194; 95% CI, 0.039–0.967; p = 0.045) were associated with asthma and musculoskeletal pain (Nagelkerke R2 = 0.206). Conclusion: Musculoskeletal pain and musculoskeletal pain syndromes were lower in adolescents with asthma. Female sex was associated with musculoskeletal pain in asthmatic, whereas patients with asthma symptoms and well-controlled disease reported a lower prevalence of musculoskeletal pain.

Resumo: Introdução: Os parâmetros espinopélvicos relacionados ao equilíbrio sagital vêm ganhando cada vez mais importância devido a sua correlação com as taxas de satisfação dos pacientes. Objetivo: O objetivo do estudo foi avaliar as alterações no equilíbrio sagital após cirurgia da coluna lombar com a técnica PLIF, fusão intersomática lombar posterior. Métodos: A população do estudo foi composta por pacientes adultos com doença degenerativa da coluna submetidos a artrodese da coluna lombar por via posterior. Foram incluídos pacientes com idade entre 18 e 70 anos, submetidos àcirurgia no período de 2015 a 2017, divididos em grupo de artrodese curta (1 nível) e grupo de artrodese longa (2 a 4 níveis). Foi realizada análise radiográfica dos parâmetros espinopélvicos, medidos antes e após a artrodese lombar, utilizando o softwareSURGIMAP. Em seguida, a variação entre as medidas pré e pós-operatórias foi avaliada e foram realizadas análises de correlação e regressão linear entre os parâmetros. Resultados: A amostra foi composta por 80 pacientes (48 homens). A média de idade dos pacientes do grupo artrodese curta foi inferior à do grupo artrodese longa (52,67 ± 9,66 anos versus 59,37 ± 9,30, respectivamente; p<0,0025). Foram identificadas variações significativas na lordose lombar, inclinação pélvica, eixo vertical sagital, ângulo pélvico T1 e incidência pélvica menos lordose lombar tanto no grupo de artrodese curta e como de artrodese longa. A variação foi significativamente maior no grupo de artrodese longa do que no grupo de artrodese curta. Conclusão: Em adultos com doença degenerativa da coluna lombar, a artrodese curta e longa usando atécnica PLIF permite a correção dos parâmetros espinopélvicos. Nível de evidência III; Estudo retrospectivo comparativo.

ABSTRACT Introduction: Spinopelvic parameters related to sagittal balance have become increasinglyimportantamong spine surgeons due to their correlation with patient satisfaction rates. Objective: The goal of this study was to evaluate changes in spinal sagittal balance after lumbar spine surgery using PLIF, the posterior lumbar interbody fusion technique. Methods: The sample consisted of adult patients with degenerative spinal disease submitted to posterior lumbar arthrodesis. Patients between 18 and 70 years of agewho underwent surgeryfrom 2015 to 2017 were included in the study and divided into short (1 level) and long arthrodesis (2 to 4 levels) groups. Radiographic analysis of the spinopelvic parameters, measured before and after lumbar arthrodesis, was conducted using the SURGIMAP software. Then we evaluated the variation between pre- and postoperative measurements and performed correlation and linear regression analyses between the parameters. Results: The sample was composed of 80 patients (48 men). The mean age was lower in the short arthrodesis group than in the long arthrodesis group (52.67 ± 9.66 years versus 59.37 ± 9.30 years, respectively; p<0.0025). Significant variations in lumbar lordosis, pelvic tilt, sagittal vertical axis, T1 pelvic angle, and pelvic incidence minus lumbar lordosis were found in both short and long arthrodesis groups. The variation was significantly larger in the long than in the short arthrodesis group. Conclusion: In adult degenerative spine disease, short and long arthrodesis of the lumbar spine by PLIF allows correction of the spinopelvic parameters. Level of evidence III; Retrospective, comparative study.

Resumen: Introducción: Los parámetros espinopélvicos relacionados con el equilibrio sagital han ido ganando cada vez más importancia debido a su correlación con los índices de satisfacción de los pacientes. Objetivo: El objetivo del estudio fue evaluar los cambios en el equilibrio sagital después de la cirugía de columna lumbar con la técnica PLIF, fusión intersomática lumbar posterior. Métodos: La población de estudio fue compuesta por pacientes adultos con enfermedad degenerativa de la columna sometidos a artrodesis de columna lumbar por vía posterior. Se incluyeron pacientes entre 18 y 70 años, sometidos a cirugíaentre 2015 y 2017, divididos en grupos de artrodesis corta (1 nivel) y grupo de artrodesis larga (2 a 4 niveles). El análisis radiográfico de los parámetros espinopélvicos, medidos antes y después de la artrodesis lumbar,se realizó utilizando el software SURGIMAP. A continuación, se evaluó la variación entre las mediciones pre y postoperatorias y se realizaron análisis de correlación y regresión entre los parámetros. Resultados: La muestra estabacompuesta por 80 pacientes (48 hombres). La edad media de los pacientes del grupo de artrodesis corta era inferior a la del grupo de artrodesis larga (52,67 ± 9,66 años frente a 59,37 ± 9,30, respectivamente; p<0,0025). Se identificaron variaciones significativas en cuanto a lordosis lumbar, inclinación pélvica, eje vertical sagital, ángulo pélvico T1 e incidencia pélvica menos lordosis lumbar en los grupos de artrodesis corta y larga. La variación fue significativamente mayor en el grupo de artrodesis larga que en el de artrodesis corta.. Conclusión: En adultos con enfermedad degenerativa de la columna lumbar, la artrodesis corta y larga mediante la técnica PLIF permite corregir los parámetros espinopélvicos. Nivel de evidencia III; Estudio retrospectivo comparativo.

RESUMO O artigo propõe uma explicação para as variações das taxas de homicídios no Brasil nas duas últimas décadas. A partir da comparação de experiências etnográficas vividas no universo faccional de quatro capitais (São Paulo, Porto Alegre, São Luís e Maceió), propomos duas estratégias analíticas: 1) a desagregação de séries quantitativas de taxas de homicídios por perfis de vítimas e 2) a construção de sinopses históricas dos conflitos faccionais locais. Demonstramos como as taxas de homicídio, em perfis sociodemográficos específicos, oscilam a partir das mudanças nos conflitos faccionais locais e puxam as variações das taxas agregadas.

ABSTRACT The paper proposes an explanation for the variations in homicide rates in Brazil in the past two decades. Based on the comparison of ethnographic experiences lived in the criminal universe of four capital cities (São Paulo, Porto Alegre, São Luís and Maceió), we propose two analytical strategies: 1) the breakdown of quantitative homicide rate data by victim profile, and 2) the construction of historical synopses of conflicts between factions at the local level. We demonstrate how homicide rates, in specific socio-demographic profiles, oscillate based on changes in conflicts between factions at the local level conflicts, and influence variations in the aggregate rates.

ABSTRACT Background: The objective of the present work was to investigate the influence of a pre-treatment of microbial-rich digestate (liquid mesophilic anaerobic digestate - AD-supernatant) on the morphology, crystallinity, and thermal stability of cellulose pulp fiber. Results: The six most abundant bacteria in the AD-supernatant were determined by 16S analysis. The bacteria population was comprised mostly of Bacteroides graminisolvens (66%) and Parabacteroides chartae (28%). Enzymatic activity from the bacteria partially removed the amorphous components and increased the crystallinity and crystallite size of the cellulose substrate. The fiber pulp was incubated in AD-supernatant for 5, 10, and 20 days. The X-ray diffraction data provided evidence that the amorphous portion of the cellulose was more readily and quickly hydrolyzed than the crystalline portion. The longest incubation times (20 days) resulted in substantial deconstruction of the cellulose fiber structure and decreased the thermal degradation temperature. Conclusion: The anaerobic digestate is inexpensive and could be used to effectively aid in the pre-treatment of cellulose on large scale transformation processes, e.g. for making biofuels, cellulose micro/nanofiber production or engineered fiber-based materials.

ABSTRACT The present work evaluates the effect of pyraclostrobin fungicide on the nutritional quality of mulberry leaves, silkworm cocoon production and silk fiber mechanical performance. The evaluation was performed in two consecutive years. In Spring 2015, mulberry plants were treated twice with 4 doses of pyraclostrobin (0, 100, 200, and 300 g.ha-1), 30 and 15 days before pruning of the branches. In Spring 2016, the same plants received the same doses of pyraclostrobin only 30 days before pruning of the branches. Fifth instar caterpillars were fed on treated mulberry leaves. The mineral content of mulberry leaves was determined on pruning day of the branches and 30 days before. The consumption of mulberry leaves and the mortality rate of the caterpillars fed with the treated leaves was verified, and the cocoons obtained were classified and weighed. Silk fibers were submitted to mechanical evaluation by tensile test. Morphological and physical modification were evaluated by Scanning Electron Microscope (SEM) and X-ray diffraction (XRD). In 2015, the mortality of caterpillars fed on leaves treated with pyraclostrobin was at least 26.7% higher than the control. At 2016 even with a single application the weight of the cocoons was lower. The main variation in the mineral content was observed in Mn and Fe nutrients. Mineral intake had a noticeable effect in both crystallinity and tensile strength. Results show that the use of pyraclostrobin may reduce the mechanical behavior of silk thread up to 70%, indicating that its use is not indicated for mulberry planting aiming silk feeding.

Abstract The multicriteria decision-making process is still an open problem, especially when the decision criteria are not numerical or fully outlined. Several numerical, intelligent, or hybrid techniques have been developed, creating contributions to this problem's solution. This paper is another step in this direction. Based on the Modified Analytic Hierarchy Process (MAHP), a methodology for diagnosis and performance analysis is presented for the dispatch ranking of generating units in a thermoelectric plant. The problem is complex because it covers a power plant, where 99 generating units may be dispatched, according to 10 possible evaluation criteria, which should be used together. This article also presents details of the implementation of the sensors necessary to add to the supervisory system existing in the Palmeiras de Goias Thermal Power Plant.

ABSTRACT The objective of this study was to verify the influence of spraying nozzles on the selectivity of herbicides in eucalyptus seedlings. XR 110.02 and TTI 110.02 spraying nozzles were used for the application of the herbicides: control treatment; oxyfluorfen (150 g ha–1) and saflufenacil (98 g ha–1). The experimental arrangement was a 2 × 3 factorial one (two spraying nozzles × 3 herbicides), using a randomized complete block design with four replications. The application was performed 15 days after transplanting the seedlings. Plant height (PH), stem diameter (SD), number of leaves (NL), total dry matter (DM), leaf area (LA), visual phytotoxicity (P), quantum efficiency of photosystem II - Fv/Fm, electron transport rate (ETR) and SPAD (S) index were evaluated. The XR 110.02 and TTI 110.02 nozzles did not change the selectivity of oxyfluorfen and saflufenacil.

RESUMO O trabalho apresenta um estudo sobre os efeitos decorrentes da modificação da mesogeometria de uma broca helicoidal de metal-duro com revestimento de TiAlN sobre o acabamento superficial do aço de alta resistência e baixa liga DIN S700MC utilizando diferentes condições de aplicação de fluidos lubrirrefrigerantes (em abundância, em mínima quantidade e a seco). Para tanto, foram consideradas como variáveis de resposta a rugosidade do furo, o dimensional da rebarba gerada e a camada afetada pelo calor. Os resultados mostram que a utilização da broca com mesogeometria alterada gerou uma redução dos valores de rugosidade, maior valor dimensional da rebarba gerada e maiores valores de modificação microestrutural pelo calor. Com relação aos meios lubrirrefrigerantes, os resultados de rugosidade não foram influenciados pelas diferentes condições de aplicação; o fluido em abundância, juntamente com a broca sem modificação, apresentou os menores valores de rebarba; não houve variações expressivas entre a aplicação do fluido em abundância e em mínima quantidade na análise da camada afetada pelo calor.

ABSTRACT This paper presents an investigation on the behavior and effect of the machining process by drilling through a DIN S700MC steel alloy, correlating the preparation of cutting-edge geometry with different coolinglubrication conditions, and focusing on the surface finishing of the machined part. In this context, experimental tests were performed with different cooling-lubrication systems (abundance, MQL, and dry) using solid carbide twist drills, coated with titanium aluminum nitride, with or without meso-geometry preparation (roundings). As response variables were assessed the texture (roughness), the layer affected by heat throughout the hole and burr dimensional profiles. The results indicate a significant reduction of roughness values when using the rounding drill flank, face and guides. Statistically, this result was not influenced by the different cooling-lubrication systems. Regarding burr dimension generated by the process, the tool with no meso-geometry preparation presented the same values along with the application of fluid in abundance (emulsion). In the analysis of the layer affected by heat, the tool with meso-geometry preparation presented lower values of the affected layer (microstructure change) and, statistically, there were no significant variations between the application of fluid in abundance and with MQL.

Resumo Objetivo: Avaliar o uso de televisão e dispositivos eletrônicos em adolescentes com dor e síndromes musculoesqueléticas. Métodos: Foi feito um estudo transversal com 299 adolescentes saudáveis de uma escola particular. Todos os alunos responderam a um questionário autoaplicável, que incluiu perguntas sobre: dados demográficos, prática de atividade física, sintomas de dor musculoesquelética e o uso de televisão/dispositivos eletrônicos (computador, internet, jogos eletrônicos e celular). Sete síndromes musculoesqueléticas foram avaliadas: fibromialgia juvenil, síndrome de hipermobilidade articular benigna, síndrome miofascial, tendinite, bursite, epicondilite e síndrome de dor regional complexa. Resultados: A concordância entre o pré-teste e reteste foi de 0,83. Dor musculoesquelética e síndromes musculoesqueléticas foram encontradas em 183/299 (61%) e 60/183 (33%), respectivamente. As medianas de idade [15 (10-18) versus 14 (10-18) anos, p = 0,032] e de anos de escolaridade [10 (5-12) vs. 9 (5-12) anos, p = 0,010] foram significantemente maiores em adolescentes com dor musculoesquelética em comparação com aqueles sem essa condição. As frequências do sexo feminino (59% versus 47% p = 0,019), uso do telefone celular (93% contra 81%, p = 0,003) e do uso simultâneo de pelo menos dois dispositivos eletrônicos (80% vs. 67%, p = 0,011) foram significantemente maiores no grupo de adolescentes com dor musculoesquelética. Comparações adicionais entre os adolescentes com e sem síndromes musculoesqueléticas revelaram que a frequência do sexo feminino foi significantemente maior no primeiro grupo (75% versus 25%, p = 0,002) e com mediana significantemente reduzida de horas de jogos eletrônicos nos fins de semana e feriados [1,5 (0-10) vs. 3 (0-17) horas/dia, p = 0,006]. Conclusões: Uma alta prevalência de dor/síndromes musculoesqueléticas foi observada em adolescentes do sexo feminino. A dor musculoesquelética foi predominantemente relatada entre alunos com mediana de idade de 15 anos e que usavam pelo menos dois dispositivos eletrônicos simultaneamente. O uso reduzido de jogos eletrônicos foi associado à presença de síndromes musculoesqueléticas.

Abstract Objective: To evaluate television and simultaneous electronic devices use in adolescents with musculoskeletal pain and musculoskeletal pain syndromes. Methods: A cross-sectional study was performed in 299 healthy adolescents of a private school. All students completed a self-administered questionnaire, including: demographic data, physical activities, musculoskeletal pain symptoms, and use of simultaneous television/electronic devices (computer, internet, electronic games, and cell phones). Seven musculoskeletal pain syndromes were also evaluated: juvenile fibromyalgia, benign joint hypermobility syndrome, myofascial syndrome, tendinitis, bursitis, epicondylitis, and complex regional pain syndrome. Results: Inter-rater agreement between pretest and retest was 0.83. Musculoskeletal pain and musculoskeletal pain syndrome were found in 183/299 (61%) and 60/183 (33%), respectively. The median age (15 [10-18] vs. 14 [10-18] years, p = 0.032) and years of education (10 [5-12] vs. 9 [5-12] years, p = 0.011) were significantly higher in adolescents with musculoskeletal pain when compared with those without this condition. The frequencies of female gender (59% vs. 47%, p = 0.019), cell phone use (93% vs. 81%, p = 0.003), and simultaneous use of at least two electronic devices (80% vs. 67%, p = 0.011) were significantly higher in the former group. Further comparisons between adolescents with and without musculoskeletal pain syndromes revealed that the frequency of female gender was significantly higher in the former group (75% vs. 25%, p = 0.002), and with a significantly reduced median of weekends/holidays electronic games use (1.5 [0-10] vs. 3 [0-17] h/day, p = 0.006). Conclusions: A high prevalence of musculoskeletal pain/syndromes was observed in female adolescents. Musculoskeletal pain was mostly reported at a median age of 15 years, and students used at least two electronic devices. Reduced use of electronic games was associated with musculoskeletal pain syndromes.