ABSTRACT During experiment planning, determining the number of replicates for tested treatments is important because it directly affects the accuracy of the obtained results. This study was conducted to determine the number of measurements (repetitions) necessary to evaluate the yield traits and soluble solids in Cantaloupe and Gália melon hybrid trials. The study comprised twenty-one experiments, nine for evaluating eight Cantaloupe melon hybrids, and twelve for evaluating nine Galia melon hybrids, conducted in a randomized complete block design with three replicates each. Analysis of variance was performed, and repeatability and genotypic determination coefficients were estimated for each experiment. The use of three repetitions allowed identification of superior genotypes with 83.6 and 80.7% predictions of the real values for the yield and soluble solids, respectively, for Cantaloupe melons. Evaluating the trials with Galia melon using three repetitions allowed prediction of the true value of the genotypes with 86.1 and 98.6% accuracy for fruit yield and soluble solids, respectively. Therefore, the use of three replicates was determined to be sufficient for detecting superior genotypes both for fruit yield and soluble solid content, with more than 80% certainty for their true values. planning results (repetitions twentyone twenty one experiments hybrids performed 836 83 6 83. 807 80 7 80.7 respectively melons 861 86 1 86. 986 98 98.6 Therefore content 8 80. 9 98.

ABSTRACT Although lung cancer (LC) is one of the most common and lethal tumors, only 15% of patients are diagnosed at an early stage. Smoking is still responsible for more than 85% of cases. Lung cancer screening (LCS) with low-dose CT (LDCT) reduces LC-related mortality by 20%, and that reduction reaches 38% when LCS by LDCT is combined with smoking cessation. In the last decade, a number of countries have adopted population-based LCS as a public health recommendation. Albeit still incipient, discussion on this topic in Brazil is becoming increasingly broad and necessary. With the aim of increasing knowledge and stimulating debate on LCS, the Brazilian Society of Thoracic Surgery, the Brazilian Thoracic Association, and the Brazilian College of Radiology and Diagnostic Imaging convened a panel of experts to prepare recommendations for LCS in Brazil. The recommendations presented here were based on a narrative review of the literature, with an emphasis on large population-based studies, systematic reviews, and the recommendations of international guidelines, and were developed after extensive discussion by the panel of experts. The following topics were reviewed: reasons for screening; general considerations about smoking; epidemiology of LC; eligibility criteria; incidental findings; granulomatous lesions; probabilistic models; minimum requirements for LDCT; volumetric acquisition; risks of screening; minimum structure and role of the multidisciplinary team; practice according to the Lung CT Screening Reporting and Data System; costs versus benefits of screening; and future perspectives for LCS. LC (LC tumors 15 stage 85 cases (LCS lowdose low dose (LDCT LCrelated related 20 20% 38 cessation decade populationbased population recommendation incipient necessary Surgery Association literature studies reviews guidelines reviewed criteria findings lesions models acquisition team System 1 8 2 3

RESUMO O câncer de pulmão (CP) é uma das neoplasias mais comuns e letais no Brasil, e apenas 15% dos pacientes são diagnosticados nos estágios iniciais. O tabagismo persiste como o responsável por mais de 85% de todos os casos. O rastreamento do CP (RCP) por meio da TC de baixa dosagem de radiação (TCBD) reduz a mortalidade do CP em 20%, e, quando combinado com a cessação do tabagismo, essa redução chega a 38%. Na última década, diversos países adotaram o RCP como recomendação de saúde populacional. No Brasil, embora ainda incipiente, a discussão sobre o tema é cada vez mais ampla e necessária. Com o intuito de aumentar o conhecimento e estimular o debate sobre o RCP, a Sociedade Brasileira de Cirurgia Torácica, a Sociedade Brasileira de Pneumologia e Tisiologia e o Colégio Brasileiro de Radiologia e Diagnóstico por Imagem constituíram um painel de especialistas para elaborar as recomendações para o RCP. As recomendações aqui apresentadas foram baseadas em revisão narrativa da literatura, com ênfase em grandes estudos populacionais, em revisões sistemáticas e em recomendações de diretrizes internacionais, sendo construídas após ampla discussão pelo grupo de especialistas. Os temas revisados foram os seguintes: porque rastrear, considerações gerais sobre tabagismo, epidemiologia do CP, critérios de elegibilidade, achados incidentais, lesões granulomatosas, modelos probabilísticos, requisitos mínimos da TCBD, aquisições volumétricas, riscos do rastreamento, estrutura mínima e papel da equipe multidisciplinar, conduta segundo o Lung CT Screening Reporting and Data System (Lung-RADS), custos vs. benefícios e perspectivas do rastreamento. (CP Brasil 15 iniciais 85 casos (RCP TCBD (TCBD 20 20% 38 38% década populacional incipiente necessária Torácica literatura populacionais internacionais seguintes rastrear elegibilidade incidentais granulomatosas probabilísticos volumétricas multidisciplinar LungRADS, LungRADS RADS , (Lung-RADS) vs 1 8 2 3 (Lung-RADS

ABSTRACT. Determining the number of replicates required to produce statistically testable results based on previously conducted tests is important to minimize labor costs via the use of existing information. The objective of this work was to determine the number of repetitions necessary to evaluate the characters of productivity and soluble solids in hybrids of two types of Inodorus melons. The study consisted of 20 experiments: 12 evaluated 10 hybrids of honeydew melons and 8 evaluated 13 hybrids of yellow melons. The experimental design consisted of randomized blocks with three replicates. Analysis of variance was performed to estimate the repeatability and genotypic determination coefficients. Variability in accurately predicting the genotype was observed for different number of repetitions between the evaluated characters and melon types. In the yellow melon, experiments with three repetitions allowed the accurate identification of superior genotypes with 81.1 and 61.9% certainty for productivity and soluble solids, respectively. In the honeydew melon, 62.4 and 71.2% accuracy was obtained for productivity and soluble solids, respectively. ABSTRACT information 2 1 coefficients 811 81 81. 619 61 9 61.9 respectively 624 62 4 62. 712 71 71.2 6 61. 7 71.

SUMMARY OBJECTIVE: Intraoperative complications of hysteroscopy, such as the creation of a false passage, cervix dilatation failure, and uterine perforation, may require suspension of the procedure. Some patients refuse a new procedure, which delays the diagnosis of a possible serious uterine pathology. For this reason, it is essential to develop strategies to increase the success rate of hysteroscopy. Some authors suggest preoperative use of topical estrogen for postmenopausal patients. This strategy is common in clinical practice, but studies demonstrating its effectiveness are scarce. The aim of this study was to evaluate the effect of cervical preparation with promestriene on the incidence of complications in postmenopausal women undergoing surgical hysteroscopy. METHODS: This is a double-blind clinical trial involving 37 postmenopausal patients undergoing surgical hysteroscopy. Participants used promestriene or placebo vaginally daily for 2 weeks and then twice a week for another 2 weeks until surgery. RESULTS: There were 2 out of 14 (14.3%) participants with complications in the promestriene group and 4 out of 23 (17.4%) participants in the placebo group (p=0.593). The complications were difficult cervical dilation, cervical laceration, and vaginal laceration. CONCLUSION: Cervical preparation with promestriene did not reduce intraoperative complications in postmenopausal patients undergoing surgical hysteroscopy. OBJECTIVE hysteroscopy passage failure perforation procedure pathology reason practice scarce METHODS doubleblind double blind 3 surgery RESULTS 1 14.3% 143 (14.3% 17.4% 174 17 (17.4% p=0.593. p0593 p p=0.593 . 0 593 (p=0.593) dilation laceration CONCLUSION 14.3 (14.3 17.4 (17.4 p059 p=0.59 59 (p=0.593 14. (14. 17. (17. p05 p=0.5 5 (p=0.59 (14 (17 p0 p=0. (p=0.5 (1 p=0 (p=0. ( p= (p=0 (p= (p

Abstract Few long-term studies assess the discoloration induced by hydraulic calcium silicate-based cement on dental structures. In addition, as far as we know, no long-term study has assessed the discoloration induced by these cement on composite resin. Objective This in vitro study aimed to assess, during a period of two years, the discoloration potential of different hydraulic calcium silicate-based cements (hCSCs) on the enamel/dentin structure and composite resin restoration. Methodology A total of 40 enamel/dentin discs were obtained from bovine incisors, and 40 composite resin discs (10 mm in diameter × 2 mm thick) were fabricated. A 0.8 mm-deep cavity was made in the center of each disc and filled with the following hCSCs (n=10): Original MTA (Angelus); MTA Repair HP (Angelus); NeoMTA Plus (Avalon); and Biodentine (Septodont). An initial color measurement was performed (T0 - baseline). After 7, 15, 30, 45, 90, 300 days, and two years, new color measurements were performed to determine the color (ΔE00), lightness (ΔL’), chroma (ΔC’), hue differences (ΔH’), and whiteness index (WID). Results For enamel/dentin, the ΔE00 was significant among groups and periods (p<0.05). NeoMTA Plus had the greatest ΔE00. The NeoMTA Plus group had the greatest ΔE00 after two years for composite resin. Significant reduction in lightness was observed for all groups after two years (p<0.05). The most significant WID values were observed after 30 days for Biodentine (enamel/dentin) and MTA Repair HP groups (composite resin) (p<0.05). Conclusions The hCSCs changed the colorimetric behavior of both substrates, leading to greater darkening over time. The Bi2O3 in the Original MTA seems relevant in the short periods of color change assessment. longterm long term silicatebased silicate based structures addition know (hCSCs enameldentin enamel dentin restoration 4 incisors 10 (1 thick fabricated 08 0 8 0. mmdeep deep n=10 n10 n (n=10) Angelus (Angelus) Avalon (Avalon) Septodont. Septodont . (Septodont) T0 T (T baseline. baseline baseline) 7 15 45 90 ΔE00, ΔE , (ΔE00) ΔL, ΔL (ΔL’) ΔC, ΔC (ΔC’) ΔH, ΔH (ΔH’) WID. (WID) ΔE0 p<0.05. p005 p p<0.05 05 (p<0.05) 3 (enamel/dentin substrates time BiO Bi O Bi2O assessment 1 ( n=1 n1 (n=10 (Angelus (Avalon (Septodont 9 (ΔE00 (ΔL’ (ΔC’ (ΔH’ (WID p00 p<0.0 (p<0.05 n= (n=1 (ΔE0 (ΔL (ΔC (ΔH p0 p<0. (p<0.0 (n= (ΔE p<0 (p<0. (n p< (p<0 (p< (p

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.

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.

RESUMO Objetivo: Avaliar fatores de risco relacionados à evolução clínica e à desdiferenciação do osteossarcoma justacortical (parosteal, paraosteal) em osteossarcoma de alto grau. Métodos: Estudo de coorte retrospectiva realizado num período de 25 anos. Foram utilizados dados de prontuários de pacientes com diagnóstico de osteossarcoma parosteal que, em seguida, foram submetidos à análise estatística pelo Teste Exato de Fisher e pelo Teste t de Student. Resultados: Foram tratados 326 pacientes com diagnóstico de osteossarcoma, dos quais 17 (5,21%) receberam diagnóstico de osteossarcoma parosteal, 4 (1,22%) foram diagnosticados com osteossarcoma convencional e 4 (1,22%) não tinham dados mínimos necessários para análise, sendo excluídos do estudo. Dos 9 (2,76%) pacientes estudados, 3 (0,92%) evoluíram com desdiferenciação do tumor para osteossarcoma de alto grau. Dois (0,84%) pacientes apresentaram recidiva local e 2 (0,84%%) apresentaram metástases. Conclusão: Os fatores idade, sexo e volume do tumor não estão diretamente relacionados com a desdiferenciação do osteossarcoma parosteal para osteossarcoma de alto grau. Apesar de a evolução clínica mais agressiva - presença de recidivas locais e metástase - no osteossarcoma parosteal ter ocorrido nos tumores com desdiferenciação, não é possível estabelecer uma relação de causa e efeito, apenas considerá-las como fatores relacionados. Nível de Evidência IV, Série de Casos.

ABSTRACT Objective: Evaluate risk factors related to clinical evolution and dedifferentiation of parosteal (juxtacortical) osteosarcoma to high-grade osteosarcoma. Methods: Retrospective cohort study performed over a period of 25 years, using data from medical records of patients diagnosed with parosteal osteosarcoma. The data were submitted to statistical analysis by Fisher’s exact test and Student’s t-test. Results: Of the 326 patients treated for osteosarcoma, we identified 17 patients diagnosed with parosteal osteosarcoma. Of these, 4 (23.5%) were not actually diagnosed with parosteal osteosarcoma and 4 did not have the minimum data required for analysis, being excluded from the study. Of the 9 patients studied, we observed that 3 (33.3%) evolved with tumor dedifferentiation to high-grade osteosarcoma. Moreover, 2 (66.7%) had local recurrence and 2 (66.7%) metastases. Conclusion: Age, sex, and the tumor size were not directly related to the dedifferentiation from parosteal osteosarcoma to high-grade osteosarcoma. The most aggressive clinical evolution - presence of local recurrences and metastasis - in parosteal osteosarcoma occurred in tumors with dedifferentiation, however, we cannot associate each other as cause and effect, but as related factors. Level of Evidence IV, Case Series.

Resumo Introdução Este estudo relata o caso de um carcinoma adenoide cístico (CAC) de glândula de Bartholin com transformação de alto grau. O CAC de glândula de Bartholin é um tumor raro, e sua transformação de alto grau é relatada somente em tumores de cabeça e pescoço. Relato de caso Paciente de 77 anos de idade, do sexo feminino, com lesão vulvar não ulcerada na topografia da glândula de Bartholin direita. A paciente foi submetida a ressecção do tumor e realização de retalho em V-Y, seguidas de radioterapia adjuvante. O exame histopatológico revelou CAC primário de glândula de Bartholin, com áreas de transformação de alto grau e invasão perineural. O estudo imunohistoquímico com p53 mostrou reação positiva difusa e intensa em áreas com transformação de alto grau. Após 24 meses de seguimento, a paciente apresentou metástases à distância e faleceu, apesar de ter sido submetida a quimioterapia. Conclusão Pelo que sabemos, este caso é a primeira descrição na literatura de transformação de alto grau em CAC de glândula de Bartholin, e a transformação de alto grau parece estar associada à agressividade do tumor.

Abstract Introduction In the present study, we report a case of primary adenoid cystic carcinoma (ACC) of the Bartholin gland with high-grade transformation (HGT). Adenoid cystic carcinoma of the Bartholin gland is a rare tumor and HGT has only been reported in head and neck tumors. Case Report A 77-year-old woman with a non-ulcerated vulvar lesion on the topography of the right Bartholin gland. The patient was submitted to tumor resection followed by V–Y island flap and adjuvant radiotherapy. The histopathological examination revealed primary ACC of the Bartholin gland, with areas of HGT and extensive perineural invasion. The immunohistochemical study with p53 showed a diffuse and strong positive reaction in areas with HGT. After 24 months of follow-up, the patient presented distant metastases and died, despite having undergone to chemotherapy. Conclusion As far as we know, this case is the first description in the literature of HGT in ACC of the Bartholin gland, and HGT appears to be associated with tumor aggressiveness.

RESUMO Objetivo: O objetivo deste trabalho é fornecer evidências para a relação entre suspeita e diagnostico de casos de maus tratos e fraturas infantis, dado que, na literatura nacional, os estudos ainda são escassos sobre o tema. Métodos: Estudo retrospectivo envolvendo prontuário eletrônico de um hospital público de referência, em um município do estado de São Paulo, num período de 8 anos (2010 a 2018). Foram selecionados casos envolvendo crianças de até 12 anos notificados como maus tratos e apresentando fraturas, sendo os dados submetidos análise estatística. Resultados: Dentre 83 casos de maus tratos, um total de 19 pacientes (20.5%) apresentaram 23 fraturas diferentes. As vítimas em 68,42% eram meninos com média de 5 anos de idade que sofreram agressão física (79%). A maioria não teve agressor identificado (52%), sendo 21% relacionado a mãe. Os padrões de fratura encontrados envolveram em sua maioria fraturas de crânio (43,48%) e fraturas diafisárias (34,78%). Sete pacientes (30,43%) tiveram outras lesões associadas e quatro pacientes vieram a óbito (21%). Conclusão: Apesar do número de casos, foi possível identificar características e padrões relevantes. Tais dados apontam que o diagnóstico é subestimado e mostram pequenas diferenças epidemiológicas comparativas a literatura internacional. Nível de Evidência II, Estudo retrospectivo.

ABSTRACT Objective: The aim of this work is to provide evidence for the relationship between suspicion and diagnosis of cases of child abuse and fractures, since, in national literature, studies are still scarce on the subject. Methods: Retrospective study involving electronic medical records of a public reference hospital, in a city of the state of São Paulo, in a 8-year period (2010 to 2018). Cases involving children up to 12 years of age were selected when notified as abuse and presenting fractures; data were statistically analyzed. Results: Among 83 cases of abuse, 19 patients (20.5%) had 23 different fractures. The victims were mainly boys (68.42%) with a mean age of 5 years old, who suffered physical aggression (79%). The majority had no identified aggressor (52%) and 21% were related to the mother. The fracture patterns found involved, mostly, skull fractures (43.48%) and diaphysary fractures (34.78%). Seven patients (30.43%) had other associated lesions and four patients died (21%). Conclusion: Despite the number of cases, it was possible to identify relevant characteristics and patterns. These data indicate that the diagnosis is underestimated and show small epidemiological differences compared with international literature. Level of Evidence II, Retrospective study.

Resumo O fatalismo refere-se à atitude de tratar situações negativas como inerentes ao destino ou como produtos da vontade divina. Considerando suas consequências para a ação transformadora e tendo Martin-Baró como referencial teórico, no presente artigo foram analisadas as nuances do fatalismo nas narrativas de trabalhadores industriais que relataram as repercussões em suas vidas, dos acidentes de trabalho que sofreram. Do acervo de uma pesquisa qualitativa anterior, realizada por meio de entrevistas abertas e em profundidade, foram selecionadas três entrevistas cujas narrativas representavam diferentes facetas do fatalismo. As informações acessadas foram analisadas e categorizadas, momento no qual foram destacados os elementos das vivências que garantiam a manutenção do fatalismo e os movimentos da consciência que, também a partir da experiência, desafiavam o conformismo e indicavam uma potencial ruptura com o fatalismo.

Abstract Fatalism refers to the attitude of treating negative situations as inherent to destiny or as outcome of divine will. Considering the fatalism consequences impact in the transformative action and having elected Martin-Baró as theoretical reference, the present article reviewed the nuances of fatalism in the narratives of industrial workers, who reported on the repercussions of work accidents on their lives. From the data of a previous qualitative investigation, conducted through open and in-depth interviews, three interviews were selected whose narratives represented different facets of fatalism. The information accessed was analyzed and categorized, at which time the elements of the experiences that ensured the maintenance of fatalism and the movements of consciousness that, also from experience, challenged conformism and indicated a potential rupture with fatalism were highlighted.

Abstract Spondyloarthritis (SpA) is a group of chronic inflammatory systemic diseases characterized by axial and/or peripheral joints inflammation, as well as extra-articular manifestations. Over some decades, nonsteroidal anti-inflammatory drugs (NSAIDs) have been the basis for the pharmacological treatment of patients with axial spondyloarthritis (axSpA). However, the emergence of the immunobiologic agents brought up the discussion about the role of NSAIDs in the management of these patients. The objective of this guideline is to provide recommendations for the use of NSAIDs for the treatment of axSpA. A panel of experts from the Brazilian Society of Rheumatology conducted a systematic review and meta-analysis of randomized clinical trials for 15 predefined questions. The Grading of Recommendations, Assessment, Development and Evaluation methodology to assess the quality of evidence and formulate recommendations were used, and at least 70% agreement of the voting panel was needed. Fourteen recommendations for the use of NSAIDs in the treatment of patients with axSpA were elaborated. The purpose of these recommendations is to support clinicians’ decision making, without taking out his/her autonomy when prescribing for an individual patient.

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.

ABSTRACT Objectives: Candida spp. has been reported as one of the common agents of nosocomial bloodstream infections and is associated with a high mortality. Therefore, this study evaluated the clinical findings, local epidemiology, and microbiological aspects of candidemia in eight tertiary medical centers in the state of Parana, South of Brazil. Methods: In this study, we reported 100 episodes of candidemia in patients admitted to eight different hospitals in five cities of the state of Parana, Brazil, using data collected locally (2016 and 2017) and tabulated online. Results: The incidence was found to be 2.7 / 1000 patients / day and 1.2 / 1000 admissions. C. albicans was responsible for 49% of all candidemia episodes. Cancer and surgery were the two most common underlying conditions associated with candidemia. The mortality rate within 30 days was 48%, and removal of the central venous catheter (p = 0.029) as well as empirical or prophylactic exposure to antifungals were both related to improved survival (p = 0.033). Conclusions: This study highlights the high burden and mortality rates of candidemia in hospitals from Parana as well as the need to enhance antifungal stewardship program in the enrolled medical centers.

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.