Evaluation of kaolin and bauxite from the Amazonian region addition on mechanical-, physical-, chemical properties and microstructural characterization of red ceramic industry clay of Manaus metropolitan region

The present work investigated properties of red ceramic from the Amazonian region after the addition of kaolinand bauxite mixture with 0, 10, 20 and 30%wt. in red ceramic industry clay. Assessed mechanical propertieswere flexural strength and Young's modulus. The assessed physical properties were density and porosity.The microstructural images were assessed with SEM and OM microscopies. The fired samples XRD, the rawmaterials XRF and the XRD were made for chemical composition and present phases assessments. Sampleswere manufactured by uniaxial compaction and fired at 1200°C and 1250°C. Samples without the mixture ofkaolin/bauxite presented higher assessed properties, with approximately 32 MPa of flexural strength and 12%of porosity with 2.3 g/cm³ density. Although the initial idea of this work was to add the mixture of kaolin/bauxite in the red ceramic industry clay for improving assessed properties of red ceramic fired parts, thered ceramic industry clay without addition presented better properties. Such properties were attributed to thehigh aluminous materials content in the raw material. This behaviour is correlated to the fact that bauxitefrom this region presents 55%wt. of iron oxide content with aluminium oxide content lower than 25%wt.Additionally, the assessed properties of the ceramic industry parts fired at 1250°C presented this material aspromising material for ceramic products with a better added value.Keywords: Red Ceramic Industry, Red Ceramic Raw Materials, Characterization

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As particularidades clínicas da otite média: Clinical features of otitis media

A otite média é um processo inflamatório de evolução abrupta, acompanhado pelo quadro clínico típico de inflamação na orelha média, sendo sua incidência prevalente em crianças, culminando em leves repercussões clínicas, mas que deve ser adequadamente diagnosticada e tratada. Este evento clínico pode ser agudo, subagudo ou crônico com aparições típicas, evolução e manejo clínico diferenciados. O seguinte artigo é uma revisão narrativa de literatura que visa analisar a respeito das principais particularidades clínicas da Otite Média. Diante das informações coletadas, pode se elucidar que a otite média é o fator causal para implicações negativas e antibioticoterapia em crianças, logo é essencial medidas para diagnose precoce para evitar repercussões na saúde destes

Catálogo Taxonômico da Fauna do Brasil: setting the baseline knowledge on the animal diversity in Brazil

The limited temporal completeness and taxonomic accuracy of species lists, made available in a traditional manner in scientific publications, has always represented a problem. These lists are invariably limited to a few taxonomic groups and do not represent up-to-date knowledge of all species and classifications. In this context, the Brazilian megadiverse fauna is no exception, and the Catálogo Taxonômico da Fauna do Brasil (CTFB) (http://fauna.jbrj.gov.br/), made public in 2015, represents a database on biodiversity anchored on a list of valid and expertly recognized scientific names of animals in Brazil. The CTFB is updated in near real time by a team of more than 800 specialists. By January 1, 2024, the CTFB compiled 133,691 nominal species, with 125,138 that were considered valid. Most of the valid species were arthropods (82.3%, with more than 102,000 species) and chordates (7.69%, with over 11,000 species). These taxa were followed by a cluster composed of Mollusca (3,567 species), Platyhelminthes (2,292 species), Annelida (1,833 species), and Nematoda (1,447 species). All remaining groups had less than 1,000 species reported in Brazil, with Cnidaria (831 species), Porifera (628 species), Rotifera (606 species), and Bryozoa (520 species) representing those with more than 500 species. Analysis of the CTFB database can facilitate and direct efforts towards the discovery of new species in Brazil, but it is also fundamental in providing the best available list of valid nominal species to users, including those in science, health, conservation efforts, and any initiative involving animals. The importance of the CTFB is evidenced by the elevated number of citations in the scientific literature in diverse areas of biology, law, anthropology, education, forensic science, and veterinary science, among others

Evaluation of the potential use of ash from Sargassum spp. as a mineral addition in Portland cement composites

A alta demanda da indústria da construção civil por utilizar recursos naturais, na forma de gerar novos produtos e de melhorar suas qualidades e eficiências, criam novas oportunidade para a economia circular. Nesse trabalho, utilizou-se as algas do gênero do Sargassum spp. (S. natans e S. fluitans), da classe da Phaeophyceae, encontrada em regiões tropicais e temperadas, presente em maior quantidade na região determinada como grande cinturão do Mar dos Sargaços. Essas algas causam sérios impactos ambientais, econômicos e sociais decorrentes de suas arribadas. Além de causar efeitos nocivos à saúde humana devido as emissões de gases de metano, sulfeto de hidrogênio e amônia durante sua decomposição. Além disso, as algas apresentam importantes aplicações para agroindústria e bens pecuários, industrias farmacêutica e alimentícias, bioenergia, materiais avançados e compósitos. Apesar do destaque de várias aplicações com o uso das algas de sargaço, poucos estudos foram realizados na parte da construção civil com a incorporação da alga de sargaço em compósitos de cimento Portland. Neste contexto, o trabalho tem o objetivo de avaliar o potencial de uso da cinza de Sargassum spp. como adição mineral, em substituição parcial do agregado miúdo, em argamassas de cimento Portland. As amostras das algas de sargaço foram coletadas na Praia de São Pedro, no estado do Maranhão. As algas, na forma seca, foram ensacadas e transportadas até o destino final no Laboratório de Construções Rurais e Ambiência. Utilizou-se forno resistivo na temperatura de 500ºC, por duas horas e taxa de aquecimento de 10°C/min, para obtenção das cinzas de sargaço. As cinzas foram analisadas em pastas cimentícias de 0%, 10%, 20% e 30% de adição e avaliou seus resultados por difração de raios X e termogravimetria. As cinzas de sargaço foram usadas nas moldagens das argamassas em substituição do agregado miúdo, em teores de 0%, 5%, 10% e 20%. Avaliou-se o desempenho das argamassas nos ensaios de compressão após 7, 28 e 63 dias de cura e as suas características físicas. Além disso, analisou-se a cinza de sargaço por fluorescência de raios X, perda ao fogo, distribuição granulométrica, difração de raios X, microscopia eletrônica de varredura e a área superficial específica. Determinou-se a densidade real das matérias-primas por picnometria de gás hélio e a distribuição granulométrica. Os resultados de difração de raios X e a derivada da termogravimetria das pastas cimentícias confirmaram a formação de hidróxido de cálcio e carbonato de cálcio e a cinza de 20% que obteve maior perda de massa. A resistência à compressão das argamassa diminuiu com o aumento de 20% da cinza de sargaço. Com a ANOVA e o Teste de Tukey foi possível fazer a comparação entre as médias e obteve que a substituição de até 10% é aceitável nas argamassas. Comparando as caracterizações físicas, a argamassa de 20% teve maiores resultados de absorção de água, índices de vazios e massa específica real. Quanto maior teor de cinzas, maior será a porosidade encontrada nas argamassas. Assim, a utilização das algas de sargaço podem promover benefícios produtivos na economia circular.The high demand of the construction industry for using natural resources, in the form of generating new products and improving their qualities and efficiencies, creates new opportunities for the circular economy. In this work, algae of the genus Sargassum spp. (S. natans and S. fluitans), of the Phaeophyceae class, found in tropical and temperate regions, present in greater quantity in the region determined as the large belt of the Sargasso Sea. These algae cause serious environmental, economic and social impacts resulting from their arrivals. In addition to causing harmful effects to human health due to the emissions of methane, hydrogen sulfide and ammonia gases during its decomposition. In addition, algae have important applications for agro-industry and livestock, pharmaceutical and food industries, bioenergy, advanced materials and composites. Despite the highlight of several applications with the use of sargassum algae, few studies have been carried out in the civil construction area with the incorporation of sargassum algae in Portland cement composites. In this context, the work aims to evaluate the potential use of ash from Sargassum spp. as a mineral addition, in partial replacement of the fine aggregate, in Portland cement mortars. The sargassum algae samples were collected at Praia de São Pedro, in the state of Maranhão. The algae, in dry form, were bagged and transported to the final destination at the Rural Construction and Ambience Laboratory. A resistive oven was used at a temperature of 500°C for two hours and a heating rate of 10°C/min to obtain the sargassum ash. The ash was analyzed in cementitious pastes with 0%, 10%, 20% and 30% addition and the results were evaluated by X-ray diffraction and thermogravimetry. The sargassum ash was used in the molding of the mortars to replace the fine aggregate, in levels of 0%, 5%, 10% and 20%. The performance of the mortars in the compression tests after 7, 28 and 63 days of curing and their physical characteristics were evaluated. In addition, sargassum ash was analyzed by X-ray fluorescence, loss on fire, granulometric distribution, X-ray diffraction, scanning electron microscopy and specific surface area. The actual density of the raw materials was determined by helium gas pycnometrics and the granulometric distribution. The results of X-ray diffraction and the thermogravimetry derivative of the cement pastes confirmed the formation of calcium hydroxide and calcium carbonate and the ash of 20% had the highest mass loss. The compressive strength of the mortar decreased with the increase of 20% of the sargassum ash. With ANOVA and Tukey\'s Test, it was possible to compare the averages and found that the replacement of up to 10% is acceptable in mortars. Comparing the physical characterizations, the 20% mortar had better results in terms of water absorption, void rates and real specific mass. The higher the ash content, the greater the porosity found in the mortars. Thus, the use of sargassum algae can promote productive benefits in the circular economy