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Recent research has been focused on developing high-performance sandwich structures using renewable resources. The adoption of bamboo rings as a core material and bio-based adhesives has emerged as a promising sustainable design solution for panel construction. It is therefore critical to conduct accelerated ageing tests on these materials to evaluate the impact of environmental humidity on their degradation and durability. This study assessed the effects of moisture ageing on the physic-mechanical properties of eco-friendly sandwich panels and their constituents (aluminium skins, bamboo ring core and castor oil bio-adhesive). Mechanical evaluations of sandwich panels with compacted and spaced bamboo ring cores were performed under varying humidity conditions. Bamboo rings exhibited variable bulk density due to swelling and loss of organic material over time. They also demonstrated increased compressive properties after 2 years of natural ageing but reduced performance after 30 days at 100 % relative humidity. The mechanical properties of the bio-based polymer were enhanced through water-ageing exposure. Sandwich panels constructed with compacted bamboo ring cores exhibited higher bending properties than those with spaced ring core architecture, with the latter showing failures characterised by a wrinkling effect on both skins followed by debonding.

Abstract This work investigates the effect of eco-friendly chemical treatments on the mechanical and physical properties of composite laminates based on sisal fibres. A 2231 full-factorial design is conducted to test the influence of chemical solution types, fibre treatment time, and polymer matrix type on the mechanical and morphological characterisation of the composites. Chemical treatments remove impurities from fibre surfaces, and enhance fibre-matrix adhesion. The treatments, especially with sodium carbonate (Na2CO3), also progressively reduce the hemicellulose fibre content. Polyester composites made with sisal fibres treated with Na2CO3 for 96h achieve enhanced strength and stiffness under tensile, compressive and impact loads. The results evidence the feasibility and efficiency of the proposed eco-friendly treatments for natural fibres and the application of renewable fibre laminates in secondary structural applications.

Biosurfactants are amphipathic molecules, biodegradable, with reduced toxicity. They can be synthesized by fermentative processes from oleaginous compounds and agro-industrial by-products. In this context, the present study describes the production and the physical, chemical, and structural characterization of the bioemulsifier secreted by the yeast Scheffersomyces shehatae 16-BR6-2AI in a medium containing hemicellulosic sugarcane bagasse hydrolysate combined with soybean oil. The bioemulsifier was produced in Erlenmeyer flasks and isolated; then, the physicochemical and structural characterization of the formed molecule was carried out. The following fermentation parameters were obtained: YX/S = 0.45, YP/S = 0.083, and productivity of 0.076 g/L/h. The bioemulsifier was found to be a polymer containing 53% of carbohydrates, 40.92% of proteins, and 6.08% of lipids, respectively. The FTIR spectrum confirmed the presence of functional groups such as amides, amines, and carbonyls. The bioemulsifier was stable over a range of temperature (−20 °C to 120 °C), salinity (1–15%), and pH (2–12). It was observed that the biomolecule has a better emulsifying action in organic solvents with a non-polar character. Therefore, this biomolecule is a potential substitute for synthetic surfactants and can be used in different applications.

Este artigo realiza uma discussão inicial acerca das relações de poder e da violência nas áreas de fronteira reocupadas por diferentes grupos sociais, tais como mineradores tradicionais, prostitutas, peões e comerciantes, nos espaços dos garimpos, constituídos a partir das descobertas de jazidas diamantíferas no município de Juína, Noroeste de Mato Grosso, Brasil, entre os anos de 1987 e 1994. O poder é compreendido como relação legítima de comando e obediência, ao passo que violência é pensada como instrumento de dominação e imposição sobre o outro em locais cuja presença do Estado é incipiente. Weber e Arendt são importantes referências para o diálogo da relação entre poder e violência. A fronteira é pensada na lógica das frentes de expansão e pioneirismo de José de Souza Martins. O recurso da história oral foi utilizado para recuperar relatos de violência nesses espaços, em especial no Garimpo do Arroz.

Despite the extensive research on renewable resources (RR) and their potential applications in composite materials and sandwich structures, there remains a significant dearth of life cycle assessment (LCA) studies that comprehensively evaluate the efficacy of RR in mitigating environmental impacts (EI). To bridge this gap, the present study aims to investigate twelve different designs of sandwich panels, specifically referred to as Fibre Metal Laminates (FML). These FML combine aluminium skins (2024-T3 and 1200-H14), polymer matrices (Epoxy, Polyester, and Castor oil Bio-PU), natural fibres (Sisal, Coir, and Cynodon spp.), surface treatments for aluminium skins (sanding, NaOH, and Washprimer), and treatments for natural fibres (Ground, NaOH-treatment and untreated). A cradle-to-gate LCA is conducted, and the inventories are modelled using the OpenLCA 1.6.3 and ecoinvent 3.9 cut-off regionalized database. EI are evaluated in twelve categories, including climate change, fossil and nuclear energy use, freshwater (acidification, ecotoxicity and eutrophication), human toxicity (cancer and non-cancer), mineral resources use, ozone layer depletion, particulate matter formation, photochemical oxidant formation, and terrestrial acidification. Impact World+ method for Latin America version 1.251 is employed to calculate EI. Nine Eco-efficiency indicators and trade-off analyses are evaluated to gain insights into design decision outcomes. Among the various panels considered, FML12, manufactured with aluminium alloy 1200-H14 treated only with sanding, castor oil biopolymer and untreated coir fibres, present the most consistent eco-efficiency indicators. The reference scenario considers the average characteristics of FML (both environmental and mechanical) for trade-off analysis. Despite the fifty percent chance of better performance, FML12 is the only panel that shows higher mechanical performance and lower EI compared to the reference scenario. The importance of this article lies in the novel results obtained using the proposed eco-efficiency indicators, which can be expanded in further studies on the topic.

Effect of hydrodynamic cavitation (HC) processing on pH, °brix, separation index, viscosity and color properties, retention of nutritional bioactive compounds (Vitamin-C, total phenolics, and antioxidant), and inactivation of enzyme pectin methyl esterase (PME) in freshly expressed juice from Brazilian oranges was investigated. HC at 4 bar pressures with a treatment time of 0, 10, 20, 30, 40, 50, 60, and 90 min at low temperatures (42 °C) were studied. There was no significant change in the values of pH, and TSS was noted in HC-treated juices. Further decreased flow behavior index while increased values of flow consistency index were recorded for the juice treated with HC showing a significant physical modification of the juice. Degradation and loss in vitamin C and total phenolics were observed when juices were HC-treated for a longer time. Therefore, it was concluded that HC could be used as a non-thermal method for improving the stability and physicochemical properties of Brazilian orange juice.

Apresentação do Dossiê.

O presente artigo busca fazer uma análise, reflexão e perspectivas sobre a educação física, atividade física, promoção da saúde para benefícios na saúde física e mental. Inicialmente, apresenta fatos preocupantes com relação a vida do ser humano dentro do aspecto da saúde mental e física, agravado pela pandemia da covid-19, logo após destaca-se a importância da educação física. Aborda-se a educação física e suas correlações com o corpo e a mente, trazendo um breve contexto histórico sobre a educação física e a atividade física. A educação física e sua relação com a saúde física. A educação física e sua relação com a saúde mental. A educação física e sua integralidade envolvendo o corpo e a mente. Finaliza-se na perspectiva de melhorias para a educação assim como para o componente curricular educação física.

This study analyzed the impact of LED light on bioemulsifier production by Aureobasidium pullulans LB83 in solid-state fermentation (SSF) using pre-treated sugarcane bagasse (PSB). The biomass was subjected to alkaline pre-treatment and conducted fermentations in Erlenmeyer flasks containing 2 g of PSB that were immersed in a humectant solution with a cell concentration of 108 cells/mL. The screening involved varying LED light wavelengths (green, red, orange, and blue) over a 7-day period at 28 °C. Notably, under the influence of blue light, the process achieved maximum production, yielding an EI24% of 63.9% and 45.1% for soybean oil and kerosene, respectively. Prolonged exposure to blue light for 11 days at 28 °C resulted in maximum bioemulsifier production (75%) and cellulolytic enzyme activity (3.67 IU g−1 for endoglucanase and 0.41 IU g−1 for exoglucanase) with soybean oil and kerosene. Experiments in a bioreactor, with varying light conditions (dark, white light, and blue LED light), demonstrated that the blue LED bioreactor outperformed others, achieving EI24% values of 55.0% and 45.7% for soybean oil and kerosene, respectively. The scanning electron microscopy (SEM) confirmed yeast growth under these conditions after 9 days. Our findings highlight the significant potential of LED light to enhance bioemulsifier production by A. pullulans LB83 from PSB.

O artigo objetiva apresentar um modelo gerencial embasado na literatura científica e aplicável à doutrina castrense, destacando a inclusão de teorias da administração e gestão. Trata-se de um estudo de caso, de abordagem qualitativa e se baseia em pesquisa bibliográfica. Após o exame da produção científica e da descrição do atual modelo corporativo, procedeu-se à eleição do modelo de Forças Armadas Profissionais, tido como compatível ao atual contexto de transformações corporativas. Permitirá a construção de uma nova arquitetura que integre processos e valorize o capital humano em sua estratégia na busca por resultados corporativos e desempenho profissional.

This work focuses on the fabrication and characterisation of epoxy composites reinforced with natural fibre layers extracted from the inner bast (phloem) of the papaya plant (Carica papaya) under tensile and three-point bending loading. The papaya phloem is composed of fibrous laminas that wrap and reinforce the stem of the plant. A set of quasi-periodically arranged holes disrupt the continuity of these layers, through which the branches emerge. The fibres in each layer constitute an anisotropic honeycomb-like structure, whose elongated cells align along a single preferential direction. Papaya-reinforced epoxy composites are fabricated by hand lay-up and evaluated using two full-factorial designs based on the fibre-to-load direction in longitudinal (0°) and transverse (90°) conditions, for configurations without holes and alternating holes. Composites made with randomly-oriented short fibres are also evaluated along with the first experiment. The tensile and flexural properties obtained are compared to other materials in the literature to assess its potential as a structural material. The results show that the papaya bast fibre layers can be a promising reinforcement for polymeric composites.

The integrated approach in biorefinery mainly involves the utilization of various agroindustrial byproducts such as raw materials for the production of several biobased products like biofuels, bioenergy, and other high-value chemicals. Biofuels are the backbone of biorefineries, however, production of value-added biomolecules such as biopigments, biopolymers, biosurfactants, and nutritional yeast has been attracting great attention. The production of these biomolecules using traditional approaches has been extensively studied in the last few years owing to their promising application in different industries such as chemical, food/feed, and pharmaceuticals for the development of novel products for mankind. Moreover, the production of such biomolecules using lignocellulosic, starchy, and some other agroindustrial byproducts is still not fully explored. Hence, there is a huge scope in the development of sustainable biorefining approaches to make the technology cost-effective. The lignocellulosic biomasses usually used in biorefineries are mainly composed of cellulose, hemicellulose, and lignin, whereas starchy materials, besides starch, usually contain, protein, lipids, and some micronutrients. The processing of these biomasses through successive steps like pretreatments, enzymatic hydrolysis, and fermentation is essentially required to obtained final biobased products. Considering certain bottlenecks of above-mentioned conventional biorefineries approaches, new technologies have been proposed for the improved pretreatment of biomass and efficient enzymatic hydrolysis in order to minimize the concentration of toxic inhibitors in resulting hydrolysate. In this review, we highlighted the different agroindustrial byproducts and their applications for the production of valuable biorefinery products.

Fibre metal laminates (FMLs) are lightweight structures with high structural performance and are suitable for many industrial applications. This work describes the impact behaviour of novel sisal fibre-reinforced aluminium laminates (SiRAL) and their dependence upon the orientations of the fibres, the composite core used and the surface treatment of the metal skins. A cold-pressing technique is used to produce SiRALs in six configurations. The FMLs here also have treated or untreated aluminium skins (2024 T3) and three different types of core materials (0°/90° fabric, ±45° fabric and random matt). The ±45° core treated SiRAL provides the highest energy absorption and deflection properties. The pre-treatment of aluminium skins using sandpaper, deep cleaning and primer significantly affects the delamination of the panels under bending impact. The findings reveal that the SiRAL concept is a promising multifunctional FML suitable for different applications that require lightweight, bending and impact performance, together with sustainability characteristics.

RESUMO O presente artigo discute os resultados de pesquisa voltada para o estudo da evasão em cursos a distância com foco nos motivos ligados à instituição de ensino. Fundamentados em Heijmans, Fini e Lüscher, Lobo, Vygotsky e Luria, dentre outros referenciais, a pesquisa foi realizada com alunos de cursos técnicos subsequentes a distância de um Instituto Federal. Foram analisados documentos acadêmicos e aplicado questionário semiaberto e online para um grupo de 39 alunos evadidos. Os resultados mostraram que os motivos de evasão ligados à instituição (38%) são mais concentrados em questões metodológicas do curso a distância e em questões de comunicação interna e externa com a comunidade (divulgação e edital com lacunas). Em torno de 26% dos alunos citaram frustração com o funcionamento pedagógico do curso: o formato da aula online, o modo de atuação do professor, o apoio às atividades do aluno e a conjugação com momentos presenciais. A partir disso, pudemos inferir que as razões para evasão ligadas à metodologia de ensino e à aprendizagem a distância estão centradas numa sensação de frustração com a aprendizagem devido ao acompanhamento pedagógico insuficiente (carência de contato com o professor e o tutor não ser da área da disciplina), a qual desencadeia sentimentos de não pertencimento institucional e de desprezo pela aprendizagem do aluno, sendo que este último leva a um processo de gradativo desinteresse pelo curso culminando em evasão.

The production of biomolecules using agro-industrial by-products as feedstock is a growing trend worldwide. Selenium (Se) is a trace element essential for health, and the Se-enrichment of yeast biomass can enhance its benefits. This study investigated the feasibility of the production of Saccharomyces cerevisiae Se-enriched biomass using a medium composed of corn bran and soybean bran acid hydrolysates as carbon and nitrogen sources in a stirred-tank reactor. After hydrolysis, hydrolysates presented complex composition and high concentrations of sugars, proteins, and minerals. The use of a stirred-tank bioreactor leads to the production of 9 g/L S. cerevisiae biomass enriched with 236.93 μg/g Se, and 99% cell viability. Likewise, the combination of sugarcane molasses and soybean bran hydrolysate was effective for cell growth of a probiotic strain of S. cerevisiae with a 24.08% β-glucan content. The results demonstrated that starchy acid hydrolysates are low-cost and efficient substrates for the production of yeast biomass and derivate products and may contribute to further studies for a sustainable development of biorefinery technologies.

A articulação de diferentes métodos possibilita narrativas que perfazem as interpretações de si nas transições. A construção de explicações de si, nas narrativas, possibilita a identificação de mudanças de posicionamentos dos antepassados às gerações seguintes. Utilizamos como instrumentos as entrevistas: (a) de história de vida; (b) episódica; (c) semiestruturada, mediada por fotografias/objetos. Realizamos as análises temática, pragmática do discurso e a produção de sentidos. Observamos processos de negociação de conflitos de si com os outros, como também de si consigo mesmo. Concluímos que diferentes métodos colaboram para a identificação da produção de sentidos intergeracional.

O objetivo do artigo é entender as narrativas nas cartas de alforria, como dinâmicas de produção de sentidos intergeracionais de pessoas em situações de discriminações étnicas. Questionamos os temas nas cartas de alforria que marcam narrativas de discriminação étnica nas ações e atividades atuais. O método de pesquisa foi uma busca documental nos cartórios da cidade por cartas de alforria e inventários de família com declarações de posse de uma pessoa sobre a outra, de 1872 a 1888. Um outro método se constitui na escolha de 3 homens da mesma família no corte do corpus de narrativas de doze homens, de três gerações, da cidade de Santo Antônio de Jesus, Bahia. Foram realizadas quarenta e oito horas de gravações de áudio e vídeo em entrevistas de história de vida e episódica. Na análise de conteúdo temática da narrativa das cartas de alforria foram encontradas reverberações dos mesmos temas de discriminação, racismo e preconceito étnico nas narrativas dos participantes. Foi escolhida a narrativa de P32 por apresentar vários significados que discriminam as populações negras no interior da comunidade do Quilombo Alto do Morro, como o “trabalho doméstico”; “a minha cor assim”. O foco da narrativa enfatiza o impacto da educação, como prática cultural em detrimento aos processos discriminatórios aos “de minha cor assim”. Conclui-se que a quantidade de leis contra o racismo sinaliza questões intergeracionais importantes, em como a reverberações dos significados, a dinâmica de produção de sentidos intergeracional de negros alforriados paralisa algumas pessoas, seus ancestrais e descendentes. Ao mesmo tempo constituíram-se significados de negações, de esquecimentos dos episódios de pessoas de uma mesma família do tratamento como inferior, com todos os processos cognitivos possíveis. Palavras-Chave: intergeracionalidade, relaçõesvétnicas, produção de sentidos, populações negras.

Biosurfactants are microbial metabolites with possible applications in various industrial sectors that are considered ecofriendly molecules. In recent years, some studies identified these compounds as alternatives for the elimination of vectors of tropical diseases, such as Aedes aegypti. The major bottlenecks of biosurfactant industrial production have been the use of conventional raw materials that increase production costs as well as opportunistic or pathogenic bacteria, which restrict the application of these biomolecules. The present study shows the potential of hemicellulosic sugarcane bagasse hydrolysate as a raw material for the production of a crystalline glycolipidic BS by Scheffersomyces stipitis NRRL Y-7124, which resulted in an emulsifying index (EI24) of 70 ± 3.4% and a superficial tension of 52 ± 2.9 mN.m-1. Additionally, a possible new application of these compounds as biolarvicides, mainly against A. aegypti, was evaluated. At a concentration of 800 mg.L-1, the produced biosurfactant caused destruction to the larval exoskeletons 12 h after application and presented an letal concentration (LC50) of 660 mg.L-1. Thus, a new alternative for biosurfactant production using vegetal biomass as raw material within the concept of biorefineries was proposed, and the potential of the crystalline glycolipidic biosurfactant in larvicidal formulations against neglected tropical disease vectors was demonstrated.

Blends of milk fat and canola oil (MF:CNO) were enzymatically interesterified (EIE) by Rhizopus oryzae lipase immobilized on polysiloxane-polyvinyl alcohol (SiO2-PVA) composite, in a solvent-free system. A central composite design (CCD) was used to optimize the reaction, considering the effects of different mass fractions of binary blends of MF:CNO (50:50, 65:35 and 80:20) and temperatures (45, 55 and 65 °C) on the composition and texture properties of the interesterified products, taking the interesterification degree (ID) and consistency (at 10 °C) as response variables. For the ID variable both mass fraction of milk fat in the blend and temperature were found to be significant, while for the consistency only mass fraction of milk fat was significant. Empiric models for ID and consistency were obtained that allowed establishing the best interesterification conditions: blend with 65 % of milk fat and 35 % of canola oil, and temperature of 45 °C. Under these conditions, the ID was 19.77 % and the consistency at 10 °C was 56 290 Pa. The potential of this eco-friendly process demonstrated that a product could be obtained with the desirable milk fat flavour and better spreadability under refrigerated conditions.

Recent advances for improving physicochemical and nutritional properties of lipids are reviewed, with emphasis on products attaining by biochemical processing of natural fats and oils. Enzymatic interesterification provides an important route to modify physical and nutritional properties of milkfat without generating trans isomers. This process makes use of lipases, a versatile class of enzyme that is able to perform efficiently the target modification in both solvent and solvent free systems. The present review covers important features of lipases, lipase-catalyzed interesterification reactions and their effects on the composition and texture of the resulting product.

Sugarcane bagasse is one of the most abundant residues in Brazil due to the large number of sugaralcohol industries. This biomass contains a high concentration of carbohydrates, which can be converted into products of high economic value, such as xylitol. Xylitol, a polyol with anticariogenic properties, is similar in sweetening power to sucrose, and has high potential for use in the food and pharmaceutical industries. Several studies have been carried out to produce xylitol by biotechnological processes. However, there is little information on the use of immobilized cells in these bioprocesses. The objective of this review was to present a new possibility to produce xylitol by biotechnological processes, using sugarcane bagasse hydrolysate and immobilized cells in PVA-gel.O bagaço de cana-de-açúcar é um dos resíduos mais abundantes no Brasil devido ao grande número de indústrias sucroalcooleiras. Esta biomassa contém elevado teor de carboidratos, podendo ser utilizada na produção de compostos de interesse econômico como o xilitol. O xilitol é um poliol de cinco carbonos que apresenta poder adoçante semelhante ao da sacarose e propriedades anti-cariogênicas, tendo elevado potencial de uso nas indústrias alimentícias e farmacêuticas. Diversos estudos buscando o desenvolvimento de processos de produção de xilitol por via biotecnológica têm sido realizados, entretanto pouco tem sido escrito sobre a utilização de células imobilizadas no bioprocesso. A presente revisão tem como objetivo apresentar uma possibilidade de produção de xilitol a partir de hidrolisado hemicelulósico de bagaço de canade-açúcar, em sistema com células imobilizadas em gel de álcool polivinílico.

O objetivo foi investigar o estilo de vida, as condições e a auto-percepção da saúde e da qualidade de vida entre idosos hipertensos e não hipertensos do município de Patos de Minas (MG). Participaram 364 idosos, sendo 54,7% hipertensos. Utilizaram-se: anamnese (histórico de saúde, engajamento social, estilo de vida e saúde percebida); Escala de Lawton; Mini-Exame do Estado Mental; Escala de Qualidade de Vida de Flanagan. Foram feitas estatísticas descritivas, comparativas de grupos, correlação e regressão linear. Os resultados indicaram que a qualidade de vida foi influenciada pelas atividades física e religiosa, e pela saúde percebida, comparada a contemporâneos. A saúde percebida hoje foi influenciada pelas mesmas variáveis e pela hipertensão arterial. Considerou-se que a continuidade de estudos que investiguem a qualidade de vida e a saúde percebida é necessária para a consolidação de modelos teóricos do desenvolvimento psicossocial de idosos saudáveis ou não.

Summary A food grade lipase from Rhizopus oryzae immobilized on a hybrid polysiloxane-polyvinyl alcohol matrix (SiO2-PVA) was used as the biocatalyst to mediate the interesterification reactions of a blend containing 65% milkfat and 35% soybean oil. All the reactions occurred in an inert nitrogen atmosphere in cylindrical glass reactors (80 mL) with 40 g of the milkfat-soybean oil blend. The influence of the following variables was evaluated: biocatalyst loading (250-1500 activity units per gram of blend), biocatalyst moisture content (5-20%), temperature (45-60 °C) and incubation time (2-48 h). The reactions were monitored by determining the free fatty acid content, triacylglycerol (TAGs) composition in carbon species, and the consistency of the interesterified (IE) products. The reaction conditions were set based on the parameters that provided a high interesterification yield and good consistency of the final product within the ideal range (200 to 800 gf cm-2). Hence the best results were obtained using a biocatalyst loading of 500 U g-1 of blend with 10% moisture content at 45 °C for 4 h. Under these conditions the consistency of the interesterified product was 539.7 ± 38 gf cm-2. The results demonstrated the potential of the immobilized lipase to alter the TAGs profile of the milkfat-soybean oil blend, allowing for the production of structured lipids.