The great technological advancement in wireless communication systems and devices generated the problem of electromagnetic pollution. Developing lightweight, sustainable, and low-cost materials is necessary to minimize electromagnetic pollution. A sustainable porous carbon (PC) absorber material was obtained from the crude black liquor by a simple and low-cost synthesis, and combined with carbon nanotube (CNT), presenting excellent microwave attenuation results. The PC absorber at 20 wt.% filling ratio exhibited an intense reflection loss of ‑35.7 dB at 15.5 GHz, and bandwidth of 1.15 GHz for a thickness of 5.90 mm. By adding 0.2 wt.% of CNT, the reflection loss was -34.6 dB at 17.9 GHz, and a bandwidth of 1.54 GHz for 4.90 mm. The study reveals that the combination of PC and CNT improves the attenuation capacity, allows adjustment in the frequency range of the attenuation peak, and promotes thickness reduction. The results obtained allow us to advance studies in developing high-performance, sustainable, and low-cost microwave-absorbing materials.

Abstract Carbonaceous porous materials are strong candidates for producing low-cost, lightweight, and sustainable electromagnetic (EM) absorbing materials. This work investigates the production of radar-absorbing materials (RAM) by a simple method. Sustainable carbon xerogel (CX) was synthesized from tannin, a biosourced molecule. CX and commercial carbon nanotube (CNT) were embedded in a silicone matrix at proportions of 10 and 15 wt.% of CX and 0.1 wt.% of CNT to produce flexible composites. The morphology and structure of the carbonaceous materials were evaluated by field-emission scanning electron microscopy (FEG-SEM), Raman spectroscopy, X-ray diffraction (XRD), textural properties by N2 adsorption-desorption isotherms, and mercury porosimetry. The electromagnetic characterization of the composites was analyzed by a vector network analyzer (VNA) in the Ku-band. The results demonstrated that an increased concentration of CX in the composite improved reflection loss reaching -43.19 dB at 13.79 GHz.

ABSTRACT Radar absorbing materials (RAMs) are composites made with a polymeric matrix and an electromagnetic absorbing filler, such as carbon black (CB), silicon carbide (SiC) or manganese zinc ferrite (MnZn). To enhance their performances to attenuate an incident wave through reflection loss (RL), RAMs can be produced in multilayer structures. Usually, the RL analysis is done theoretically and experimentally validated with free space analysis. Here, it was demonstrated that multilayer structure can be designed and easily validated using rectangular waveguide, using a simpler setup and small samples. Three composites were produced using 2 wt% of CB (CB2), 40 wt% of SiC (SiC40) and 60 wt% of MnZn (MnZn60). They were characterized over the Ku-band and used to validate the multilayer structures, that were prepared by simply stacking each material inside the waveguide sample holder. One of the best results was obtained with structure SiC40+CB2 with 5.85 mm thickness, that presented a calculated RL of -21 dB at 17.8 GHz and a measured RL of -36 dB at the same frequency. In conclusion, using rectangular waveguide has been proven to be an easy, cheap, precise and fast approach to validate multilayer structures designs.

RESUMO Este trabalho apresenta as propriedades eletromagnéticas de um Material Absorvedor de Radiação Eletromagnética (MARE) feito a partir de Carbeto de Silício (SiC) e Negro de Fumo (NF) como aditivos. O compósito SiC/NF foi produzido utilizando 70 %(m/m) de matriz de silicone, e variando as concentrações do aditivo em 3 %(m/m), 2 %(m/m) e 1 %(m/m) de NF com 27 %(m/m), 28 %(m/m) e 29 %(m/m) de SiC, respectivamente. A estrutura química e a morfologia das partículas de SiC e NF foram analisadas através de espectroscopia Raman e Microscopia Eletrônica de Varredura (MEV). As propriedades dielétricas dos MAREs foram obtidas por meio do analisador de rede vetorial na faixa de frequência de 12,4 a 18,0 GHz. Os resultados de refletividade mostraram que o compósito SiC/NF com 1 %(m/m) de NF apresentou a melhor absorção de radiação eletromagnética, chegando a -47,9 dB em 16,8 GHz com uma amostra de aproximadamente 5,5 mm de espessura.

ABSTRACT Este trabalho apresenta as propriedades eletromagnéticas de um Material Absorvedor de Radiação Eletromagnética (MARE) feito a partir de Carbeto de Silício (SiC) e Negro de Fumo (NF) como aditivos. O compósito SiC/NF foi produzido utilizando 70 %(m/m) de matriz de silicone, e variando as concentrações do aditivo em 3 %(m/m), 2 %(m/m) e 1 %(m/m) de NF com 27 %(m/m), 28 %(m/m) e 29 %(m/m) de SiC, respectivamente. A estrutura química e a morfologia das partículas de SiC e NF foram analisadas através de espectroscopia Raman e Microscopia Eletrônica de Varredura (MEV). As propriedades dielétricas dos MAREs foram obtidas por meio do analisador de rede vetorial na faixa de frequência de 12,4 a 18,0 GHz. Os resultados de refletividade mostraram que o compósito SiC/NF com 1 %(m/m) de NF apresentou a melhor absorção de radiação eletromagnética, chegando a -47,9 dB em 16,8 GHz com uma amostra de aproximadamente 5,5 mm de espessura.

Resumo Objetivos: Propor uma metodologia de construção de cenários e casos simulados para aprimorar o raciocínio diagnóstico de enfermagem. Métodos: Estudo metodológico com bases teóricas e conceituais da Teoria do Duplo Processamento para construir casos e cenários de simulação clínica para o raciocínio diagnóstico de enfermagem pelo uso adequado dos raciocínios analítico e não analítico. Resultados e discussão: São apresentados e discutidos aspectos do referencial teórico e elementos operacionais, como: estrutura dos cenários, preparação da simulação, briefing, debriefing e modelagem, incorporando conteúdos necessários. A metodologia articula o conteúdo compatível com raciocínios analíticos, estudos não analíticos e medidas de acurácia diagnóstica de estudos de validação clínica. Conclusão: Entende-se ter demonstrado a exequibilidade da modelagem de casos simulados que integram o duplo processamento ao raciocínio diagnóstico de enfermagem. Implicações: Contribuição para o aprendizado em ambiente simulado mais seguro; adotando base teórica de estudos de raciocínio humano.

Abstract Objectives: Propose a methodology for the construction of simulated scenarios and cases to improve diagnostic reasoning in nursing. Method: A methodological study was conducted using theories and concepts from the dual processing theory to develop cases and scenarios of clinical simulation for diagnostic reasoning in nursing through proper use of analytical and non-analytical reasoning. Results and discussion: This study presents and discusses issues of the theoretical framework and operational elements: structure of scenarios, preparation of simulation, briefing, debriefing, and modeling, incorporating any required content. The methodology articulates content that is compatible with analytical reasoning, non-analytical studies and diagnostic accuracy measurements of clinical validation studies. Conclusion: This study demonstrated the feasibility of modeling simulated cases that combine dual processing with diagnostic reasoning in nursing. Implications: Contribution to learning in a safer simulated environment, adopting theoretical bases from studies on human reasoning.

Resumen Objetivos: Proponer una metodología de construcción de escenarios y casos simulados para mejorar el razonamiento diagnóstico de enfermería. Métodos: Estudio metodológico con bases teóricas y metodológicas de la Teoría del Doble Proceso para construir casos y escenarios de simulación clínica para el razonamiento diagnóstico de enfermería utilizando correctamente los razonamientos analítico y no analítico. Resultados y discusión: Fueron presentados y discutidos aspectos del referencial teórico y elementos operativos: estructura de los escenarios, preparación de la simulación, briefing, debriefing y construcción, incorporando contenidos necesarios. La metodología articula contenido compatible con razonamientos analíticos, no analíticos y mediciones de precisión diagnóstica de estudios de validación clínica. Conclusión: Se entiende haber demostrado la factibilidad para construir casos simulados necesarios para el doble proceso del razonamiento diagnóstico de enfermería. Implicaciones: Contribución al aprendizaje en ambiente más seguro; adoptando base teórica de estudios de razonamiento humano.

Abstract Objectives: Propose a methodology for the construction of simulated scenarios and cases to improve diagnostic reasoning in nursing. Method: A methodological study was conducted using theories and concepts from the dual processing theory to develop cases and scenarios of clinical simulation for diagnostic reasoning in nursing through proper use of analytical and non-analytical reasoning. Results and discussion: This study presents and discusses issues of the theoretical framework and operational elements: structure of scenarios, preparation of simulation, briefing, debriefing, and modeling, incorporating any required content. The methodology articulates content that is compatible with analytical reasoning, non-analytical studies and diagnostic accuracy measurements of clinical validation studies. Conclusion: This study demonstrated the feasibility of modeling simulated cases that combine dual processing with diagnostic reasoning in nursing. Implications: Contribution to learning in a safer simulated environment, adopting theoretical bases from studies on human reasoning.

Resumen Objetivos: Proponer una metodología de construcción de escenarios y casos simulados para mejorar el razonamiento diagnóstico de enfermería. Métodos: Estudio metodológico con bases teóricas y metodológicas de la Teoría del Doble Proceso para construir casos y escenarios de simulación clínica para el razonamiento diagnóstico de enfermería utilizando correctamente los razonamientos analítico y no analítico. Resultados y discusión: Fueron presentados y discutidos aspectos del referencial teórico y elementos operativos: estructura de los escenarios, preparación de la simulación, briefing, debriefing y construcción, incorporando contenidos necesarios. La metodología articula contenido compatible con razonamientos analíticos, no analíticos y mediciones de precisión diagnóstica de estudios de validación clínica. Conclusión: Se entiende haber demostrado la factibilidad para construir casos simulados necesarios para el doble proceso del razonamiento diagnóstico de enfermería. Implicaciones: Contribución al aprendizaje en ambiente más seguro; adoptando base teórica de estudios de razonamiento humano.

Resumo Objetivos: Propor uma metodologia de construção de cenários e casos simulados para aprimorar o raciocínio diagnóstico de enfermagem. Métodos: Estudo metodológico com bases teóricas e conceituais da Teoria do Duplo Processamento para construir casos e cenários de simulação clínica para o raciocínio diagnóstico de enfermagem pelo uso adequado dos raciocínios analítico e não analítico. Resultados e discussão: São apresentados e discutidos aspectos do referencial teórico e elementos operacionais, como: estrutura dos cenários, preparação da simulação, briefing, debriefing e modelagem, incorporando conteúdos necessários. A metodologia articula o conteúdo compatível com raciocínios analíticos, estudos não analíticos e medidas de acurácia diagnóstica de estudos de validação clínica. Conclusão: Entende-se ter demonstrado a exequibilidade da modelagem de casos simulados que integram o duplo processamento ao raciocínio diagnóstico de enfermagem. Implicações: Contribuição para o aprendizado em ambiente simulado mais seguro; adotando base teórica de estudos de raciocínio humano.

ABSTRACT Seed predation is a natural phenomenon that can occur either before or after dispersal and can significantly reduce the economic value and reproductive potential of plants. The babassu palm (Attalea vitrivir, Arecaceae) is important to rural communities that extract oil from its fruits for a wide variety of uses. We evaluated the predation and germination of A. vitrivirseeds in Pandeiros River Environmental Protection Area (EPA-Pandeiros) in Minas Gerais State, Brazil. Sixty individual plants were evaluated to determine their fruiting patterns. Seed predation and germination were evaluated in the natural environment for eight months for fruits divided into two treatments: scarified and intact. Germination of fruits submitted to these same treatments was also evaluated under greenhouse conditions. Our results indicated that fruiting is continuous in this species and that fruit morphology does not influence either germination or predation. Likewise, fruit scarification did not influence seed germination. Pachymerus cardo (Coleoptera: Chrysomelidae) preferentially oviposited on scarified fruits, but only after their dispersal. The predation rate in the natural environment was 14.6%. Germination was not observed under natural conditions, but reached 33.05% under greenhouse conditions.

The plant population dynamic is affected by ecological and evolutionary processes that operate at all stages of the plant life cycle. The aim of this study was to characterize the seed and seedling performance of Copaifera langsdorffii by testing four hypotheses: the resource concentration hypothesis; the relationship between seed size and germinability hypothesis; the relationship between seed size and seedling vigor hypothesis; and the intraspecific seedling competition hypothesis. All seeds used in the experiments were collected from 35 C. langsdorffii plants located in a fragment of the Brazilian cerrado (savanna). The number of fruits per plant negatively affected Rhinochenus brevicollis attacks on C. langsdorffii seeds. Therefore, this result does not support the resource concentration hypothesis, and predator satiation was used in order to explain the observed result. In general, seed germinability (percentage and time to emergence) was not influenced by seed size. The homogeneity of the experimental design, together with an abundant water supply, may have masked the effects of seed size on germinability. Seed size positively affected seedling development, corroborating the expected relationship between seed size and seedling vigor. The number of seedling per plastic bags negatively affected the growth of C. langsdorffii. The nutrient-limited soil probably promoted the below-ground competition for nutrients among seedlings. Finally, the role of evolutionary and ecological factors on C. langsdorffii population dynamics is discussed.

O beneficiamento é componente fundamental em qualquer programa organizado de produção de sementes e visa aprimorar características do lote. Objetivou-se neste trabalho estabelecer um fluxograma de beneficiamento para sementes de feijão-mungo-verde (Vigna radiata L.). Utilizaram-se sementes dois lotes. O primeiro lote foi proveniente de colheita parcelada das vagens, em três épocas, e o segundo de colheita de toda a planta, com a maioria das vagens secas. Foram testados 13 fluxogramas de beneficiamento, com a utilização da máquina de ventilador e peneiras, separador pneumático, mesa de gravidade e classificador de peneiras. As sementes foram avaliadas quanto a sua qualidade física, fisiológica e sanitária. O fluxograma de beneficiamento ideal para lotes de sementes de feijão-mungo-verde provenientes de colheita parcelada das vagens é composto pela máquina de ventilador e peneiras, seguida da mesa de gravidade. Quando os lotes de sementes forem provenientes de colheita única das vagens o ideal é o uso da máquina de ventilador e peneiras, seguida do separador pneumático e da mesa de gravidade.

Seed processing is a key part of any organized seed production program and serves to improve seed lot quality. The objective of this study was to establish a processing flowchart for mung bean seeds (Vigna radiata L.). Two seed lots were used: the first with seeds harvested at three different times and the second from a single harvest, with mostly mature pods. We tested 13 seed processing flowcharts, using a fan machine and sieves, a pneumatic separator, a gravity table and a sieve classifier. The seeds were evaluated for their physical, physiological and sanitary qualities. The ideal processing flowchart for mung bean seeds harvested at different times was the use of a fan machine and sieves followed by the gravity table. On the other hand, for seed lots from a single harvest, the ideal seed processing was a fan machine and sieves followed by a pneumatic separator and the gravity table.

A manutenção ou a elevação dos níveis de tecnologia no cultivo da soja no Cerrado é fundamental à produtividade econômica, a qual tem se revelado superior à obtida na Região Sul do Brasil. Entre as contribuições da pesquisa ao desempenho destacado da cultura da soja no Cerrado estão as novas cultivares, que representam papel fundamental para a estabilidade produtiva. A cultivar de soja BRS Celeste é uma opção para atender à demanda dos produtores. Apresenta ciclo semelhante ao da BR/EMGOPA 314 (Garça Branca), porém com produtividade superior, e com resistência às principais doenças, em especial ao cancro-da-haste (Diaporthe phaseolorum f. sp. meridionalis).

Maintenance or improvement of technology to soybean cultivation is necessary to reach economical productivity in the Brazilian Savannah, where it has shown to be superior to that obtained in the South of Brazil. New cultivars are among the contributions of research to high crop performance and yield stability. The soybean cv. BRS Celeste is an alternative to suit growers demand. It belongs to the same maturity group of cv. BR/EMGOPA 314 (Garça Branca), although it has higher yielding and shows resistance to the main diseases, especially stem canker (Diaporthe phaseolorum f. sp. meridionalis).