Avaliação de fragmentos de lenhos carbonizados de Araucariaceae por meio de análise por termogravimetria e infravermelho associado à análise multivariada

Abstract

The aim of the study is to evaluate the physical and chemical changes that occur on wood fragments submitted to different temperatures, verifying their influence on significant chemical characteristics in the forming process. Carbonization process in muffle associated to the techniques of Thermogravimetry, Fourier Transform Infrared Spectroscopy (FTIR) and multivariate analysis. The analyses were performed on 3 replicates for each burn temperature. The temperature of the thermal muffle process was in every 50 °C, from 200 °C to 600 °C. TGA were performed under nitrogen atmosphere, using a heating ramp from 25 °C min-1 to 995 °C. A range between 1900 to 650 cm-1 was used, with a resolution of 4 cm-1 and 64 scans. The PCA showed that it is possible to describe 95.73% of the data, grouping the samples into three main clusters. These clusters were used to build a SIMCA (Soft Independent Modeling of Class Analogy) model, enabling to predict with 100%. Results showed that technical associations, such as TGA, FTIR and multivariate analysis may help to characterize the natural carbonization process and, in future works, contribute to significant (paleo)environmental inferences.

Changes of wood anatomical characters of selected species of Araucaria- during artificial charring - implications for palaeontology

“…April-June 2018 analysed, as weight loss still increased with higher charring temperatures. Not surprisingly Lara et al (2017) observed similar weight losses for the three taxa investigated here, by means of thermogravimetric analysis. In many cases the qualitative features of the original wood remain intact, whereas quantitative parameters such as cell size and wall thickness change.…”

Avaliação dos lenhos carbonizados de araucariaceae em diferentes concentrações de oxigênio por meio de termogravimetria e microscopia eletrônica de varredura

“…In Figure 2 it is observed that the thermodegradation in different atmospheres present similar burning patterns. In these first moments of the transformation there are morphological changes in the structure of the samples, as well as loss of mass, with fragmentation and rounding of the materials, and their darkening (BRAADBAART; POOLE, 2008;LARA et al, 2017a;SCOTT, 2010).…”

Mapeamento De Focos De Calor No Município De Juara/Mt Nos Anos De 2016 E 2017: Construção De Banco De Dados Para Análises Ambientais Regionais

“…Nas últimas décadas os estudos sobre o fogo tiveram vários focos de pesquisa interdisciplinar com a proposta de compreender sua função biológica, ecológica e histórica (SCOTT et al, 2014). Estudos exemplificam a importância do ciclo do fogo na evolução (AVITABILE et al, 2013) e sua participação onipresente nos distúrbios dos ecossistemas (LARA et al, 2017). É possível identificar diversas espécies que criam e mantém seus habitats em função do fogo, entretanto, a interferência do homem altera sua intensidade, causando ameaças a algumas espécies (AVITABILE et al, 2013).…”