Bentonite functioned by potassium compounds as a solid catalyst for biodiesel production

Abstract Heterogeneous catalysts, especially those produced with functionalized clays, can be used for methyl transesterification at moderate temperatures. The use of bentonite clay functionalized by potassium compounds (KF, KOH, K2CO3, KCl and K2SO4) in the methyl transesterification of cottonseed oil is the object of the present study. The catalysts were produced by contacting aqueous solutions with the clay and subsequent drying. The catalysts were characterized by Hammett indicators to determine alkalinity. The methyl transesterification reactions were made in a flask with stirring and reflux at 70°C for 2 h. The performance evaluation of the reaction was carried out using regression between the absorption band area and the concentration of a biodiesel-oil mixture by infrared spectroscopy. The catalytic activity is directly associated with the alkaline character of the catalysts. The catalysts produced with KCl and K2SO4 did not show conversion in the methyl transesterification reaction, while the catalysts produced with KF, KOH and K2CO3 showed a conversion greater than 90%

Análise Bibliométrica das Pesquisas sobre Biodiesel entre 1984–2021

Interest in the production of biodiesel has been growing widely in recent years, as it can totally or partially replace mineral diesel. Biodiesel is a fuel of renewable origin that contributes to the reduction of CO2 emissions. This study makes a brief bibliometric analysis of scientific publications available in the SCOPUS database on the topic of biodiesel published. The results suggest that the increase in academic interest on the topic is more accentuated from the year 2016 onwards, and keep growing up to the present. The regions with the highest number of publications are China, Brazil, India, the United States of America and Malaysia, and they almost maintain a partnership between their researchers. The regions with the highest rate of publications are also the largest producers and consumers of biodiesel. The term "Biodiesel Production" is the most commonly observed in the titles of articles.El interés por la producción de biodiésel ha aumentado mucho en los últimos años, ya que puede sustituir total o parcialmente al diésel mineral. El biodiésel es un combustible de origen renovable que contribuye a la reducción de las emisiones de CO2. Este estudio realiza un breve análisis bibliometría de las publicaciones científicas disponibles en la base de datos SCOPUS sobre el tema del biodiésel editadas entre los años 1984 a 2021. Los resultados sugieren que el aumento del interés académico por el tema se acentúa más a partir del año 2016, y sigue creciendo hasta el presente. Las regiones con mayor número de publicaciones son China, Brasil, India, Estados Unidos de América y Malasia, y casi mantienen una asociación entre sus investigadores. Las regiones con mayor índice de publicaciones son también las mayores productoras y consumidoras de biodiésel. El término "Producción de Biodiésel" es el más comúnmente observado en los títulos de los artículos.O interesse sobre a produção de biodiesel, vem crescendo amplamente nos últimos anos, visto que este pode substituir total ou parcialmente o diesel mineral. O biodiesel é um combustível de origem renovável que contribui para redução das emissões de CO2. Este estudo faz uma breve análise bibliométrica das publicações científicas disponíveis na base de dados SCOPUS sobre o tema biodiesel. Os resultados sugerem que o aumento pelo interesse acadêmico sobre o tema é mais acentuado a partir do ano de 2016, e se mantêm crescente até o presente. Os países com maior quantidade de publicações são a China, Brasil, Índia, Estados Unidos da América e a Malásia, havendo parceria entre seus pesquisadores e instituições acadêmicas. Os países com maior taxa de publicações, também são as maiores produtoras e consumidoras de biodiesel. A termo "Produção de Biodiesel", é o mais observado nos títulos dos artigos.

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

Materials Research

p. 285-293,Apr/June.Carbon fibers are widely used in many industrial applications due the fact of their excellent properties. Carbonaceous mesophases are liquid crystalline precursor materials that can be spun into high performance carbon fibers using the melt spinning process, which is a flow cascade consisting of pressure driven flow-converging die flow-free surface extensional spinline flow that modifies the precursor molecular orientation structure. Carbon fiber property optimization requires a better understanding of the principles that control the structure development during the fiber formation processes and the rheological processing properties. This paper presents the elastic and continuum theory of liquid crystalsand computer simulations of structure formation for pressure-driven flow of carbonaceous liquid crystalline precursors used in the industrial carbon fiber spinning process. The simulations results capture the formation of characteristic fiber macro-textures and provide new knowledge on the role of viscous and elastic effects in the spinning process

CONCENTRAÇÃO DE MOLIBDENITA POR FLOTAÇÃO: AVALIAÇÃO DE PATENTES

O molibdênio produzido a partir da molibdenita possui uma enorme importância devido às várias aplicações em eletrônica, na indústria química e metalúrgica. O Brasil não detém reservas oficiais de molibdenita, mas existe uma ocorrência promissora desse mineral na Serra de Carnaíba (Bahia). Este estudo apresenta uma descrição das patentes existentes sobre a técnica de flotação de molibdenita, em particular, de granulometria fina. Os resultados mostram que o Brasil não possui patente envolvendo este tema estavam elas concentradas na China, Estados Unidos, e Canadá que possui importantes reservas deste mineral