Publicações - ciências exatas e da terra
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Priscila G. Sieben;
WYPYCH, FERNANDO;
Rilton Alves de Freitas
Palavra-chave:
Pickering emulsion;
Kaolinite
Áreas do conhecimento:
Ciências Exatas e da Terra; Engenharia e Ciencia de Materiais; Materiais de Baixa Dimensionalidade Estrutural;
Ciências Exatas e da Terra; Química; Emulsões de Pickering
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VLNIESKA, VITOR;
MUNIZ, ALINE;
ANGELO ROBERTO DOS SANTOS OLIVEIRA;
CÉSAR-OLIVEIRA, MARIA;
KUNKA, DANAYS
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VITOR VLNIESKA;
ALINE SILVA MUNIZ;
ANGELO ROBERTO DOS SANTOS OLIVEIRA;
Maria Aparecida de Oliveira;
Danays Kunka
Palavra-chave:
biodiesel;
oligoesters;
transesterification;
heterogeneous catalysis;
fatty sources;
homogeneous catalysis
Áreas do conhecimento:
Ciências Exatas e da Terra; Química de Polímeros;
Ciências Exatas e da Terra; Química; Síntese Orgânica;
Ciências Exatas e da Terra; Química; Química Orgânica; Síntese Orgânica
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Biodiesel production from first-generation feedstock has shown a strong correlation with the increase in deforestation and the necessity of larger areas for land farming. Recent estimation from the European Federation for Transport and Environment evidenced that since the 2000s decade, an area equal to the Netherlands was deforested to supply global biodiesel demand, mainly originating from first-generation feedstock. Nevertheless, biodiesel is renewable, and it can be a greener source of energy than petroleum. A promising approach to make biodiesel independent from large areas of farming is to shift as much as possible the biodiesel production chain to second and third generations of feedstock. The second generation presents three main advantages, where it does not compete with the food industry, its commercial value is negligible, or none, and its usage as feedstock for biodiesel production reduces the overall waste disposal. In this manuscript, we present an oligomeric catalyst designed to be multi-functional for second-generation feedstock transesterification reactions, mainly focusing our efforts to optimize the conversion of tallow fat and sauteing oil to FAME and FAEE, applying our innovative catalyst. Named as Oligocat, our catalyst acts as a Brønsted-Lowry acid catalyst, providing protons to the reaction medium, and at the same time, with the course of the reaction, it sequesters glycerol molecules from the medium and changes its physical phase during the transesterification reaction. With this set of properties, Oligocat presents a pseudo-homogenous behavior, reducing the purification and separation steps of the biodiesel process production. Reaction conditions were optimized applying a 42 factorial planning. The output parameter evaluated was the conversion rate of triacylglycerol to mono alkyl esters, measured through gel permeation chromatography (GPC). After the optimization studies, a conversion yield of 96.7 (±1.9) wt% was achieved, which allows classifying the obtained mono alkyl esters as biodiesel by ASTM D6751 or EN 14214:2003. After applying the catalyst in three reaction cycles, Oligocat still presented a conversion rate above 96.5 wt% and as well an excellent recovery rate.
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Abraão Jessé Capistrano de Souza;
Abraão Jessé Capistrano de Souza;
COIMBRA-ARAUJO, CARLOS H.;
MARÃO, JOSÉ A. P. F.
GALAXIES ? OPEN ACCESS COSMOLOGY, ASTRONOMY & ASTROPHYSICS JOURNAL,
v. 10,
n. 6,
p. 118
2022
DOI
Home page
Palavra-chave:
Dark energy;
Nash-Greene theorem;
Cosmological perturbations
Áreas do conhecimento:
Ciências Exatas e da Terra; Ciência da Computação; Metodologia e Técnicas da Computação; Engenharia de Software
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Ademir Alves Ribeiro;
Mael Sachine
Palavra-chave:
Convex hull;
Optimal separating hyperplane;
Support vector machines
Áreas do conhecimento:
Ciências Exatas e da Terra; Matemática Aplicada; Otimização
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Marcell Leonard Besser;
Carlos Eduardo de Mesquita Barros;
Eleonora Maria Gouveia Vasconcellos
Palavra-chave:
anfibolitos;
arqueano;
ortognaisses;
Província Transamazonas
Áreas do conhecimento:
Ciências Exatas e da Terra; Geociências; Geologia; Geocronologia;
Ciências Exatas e da Terra; Geociências; Geologia; Petrologia;
Ciências Exatas e da Terra; Geociências; Geologia; Geologia Regional
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Fabíula dos Santos Toso;
Cláudia Silveira Viera;
Ana Tereza Bittencourt Guimaraes
RESEARCH, SOCIETY AND DEVELOPMENT,
v. 11,
n. 3,
p. e16411326322
2022
Palavra-chave:
SAÚDE DO ADOLESCENTE;
Prematuridade
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FRAGA, MALTON CARVALHO;
Cristina Silveira Vega
Palavra-chave:
Echinoderm Lagerstätte;
Devonian;
Ponta Grossa Formation
Áreas do conhecimento:
Ciências Exatas e da Terra; Ciência da Computação; Metodologia e Técnicas da Computação; Engenharia de Software;
Ciências Exatas e da Terra; Geociências; Geologia; Paleontologia Estratigráfica
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SECKLER, DIEGO SECKLER;
DEA, CAMILA MASCARENHAS;
RIOS, ELISE ANE MALUF;
DE GODOI, MARCELO;
RAMPON, DANIEL;
Marcelo Gonçalves Montes D'Oca;
DOCA, CAROLINE
Áreas do conhecimento:
Ciências Exatas e da Terra; Química Orgânica; Síntese Orgânica
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In this work, we describe the use of Water Extract of Rice Straw Ash (WERSA) as an efficient sustainable approach for the Knoevenagel reaction and a reaction medium, in combination with glycerol as a co-solvent, without the employment of any additional catalyst, base, ligand, or promoter. The effect of WERSA as an
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Wanderley Cerniauskas;
SILVA, PAULO L. DATTORI DA;
Alexandre Kirilov
Palavra-chave:
Condition (P);
Characteristic set;
Periodic Solutions
Áreas do conhecimento:
Ciências Exatas e da Terra; Análise; Equações Diferenciais Parciais;
Ciências Exatas e da Terra; Matemática; Análise; Equações Diferenciais Parciais
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