Chemometric
Mostrando 1-12 de 178 artigos, teses e dissertações.
-
1. Encoding of Luminescent Ink Markers Using Low-Level Data Fusion and Chemometrics
The identification and analysis of documentary fraud is always a challenge for forensic science. Document analysis has proven to be an important branch of forensics in elucidating the authenticity of documents. The development and incorporation of luminescent inks in authentic documents have proved to be an excellent security feature. This paper purposes the
Journal of the Brazilian Chemical Society. Publicado em: 2023
-
2. Use of a Portable Microscope Combined with a Smartphone to Determine the Authenticity of Brazilian Banknotes and National Driver’s Licenses
This study proposed using a portable microscope combined with a smartphone and application (PhotoMetrix® application) to evaluate the authenticity of Brazilian banknotes (R$50 and R$100) and national driver’s licenses (NDL) through image acquisition (Samsung S7) and chemometric treatment (principal component analysis (PCA)). Six regions of the banknote we
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
3. Effects of Citrus Sudden Death Disease on Fatty Acid Profile of Orange Tree Bark
Citrus sudden death (CSD) is a disease that has affected millions of orange trees in Brazil, leading to economic losses in the order of billions of US dollars. This article examines the effects of CSD on the fatty acid composition of triacylglycerides (TAG) extracted from rootstock and scion bark. The fatty acid profile determined by gas chromatography showe
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
4. Chemometric Evaluation of Poly(3-hexylthiophene) Electrochemical Aging Path as a Function of Electrochemical Synthesis Variables
Conductive polymers are versatile materials that can be applied in many different technology fields, especially green energy. They have several advantages, such as easy synthesis, low density, and cost. However, its electric conduction property is also related to material aging with great loss of their characteristics, limiting their applicability. The in-de
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
5. Spectroscopic techniques combined with chemometrics to study organic matter in tropical soils with different degrees of pedogenetic evolution
Understanding of the organomineral interactions in soil can elucidate the humic substances (HS) formation and the humification process. This study aimed to structurally characterize the humic acids (HA) formed in tropical soils with different pedogenesis degrees. The HA fraction was extracted from soil samples in the superficial horizons of an Inceptisol and
Química Nova. Publicado em: 2022
-
6. INTERDISCIPLINARY EDUCATION THROUGH THE DEVELOPMENT OF A COST-EFFECTIVE PHOTOMETRIC PH METER SENSOR USING NATURAL PIGMENTS
There is a trend of development of analytical methodologies and technologies that allow in situ analysis, producing accurate information in real time, at low cost, using homemade experiments and devices to increase interest in scientific knowledge with a constructive approach in an interdisciplinary perspective in Chemistry Education. In this context, a phot
Química Nova. Publicado em: 2022
-
7. Volatile Metabolomics from Cashew Leaves: Assessment of Resistance Biomarkers Associated with Black Mold (Pilgeriella anacardii Arx & Müller)
Black mold, a disease caused by the fungus Pilgeriella anacardii Arx & Müller, affects cashews (Anacardium occidentale). Some cashew clones are more resistant to the pathogen; however, little is known about the chemical profile responsible for this trait. The investigation of volatile organic compounds (VOCs) from leaves of dwarf cashew clones resistant (BR
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
8. Integrated UPLC-HRMS, Chemometric Tools, and Metabolomic Analysis of Forage Palm (Opuntia spp. and Nopalea spp.) to Define Biomarkers Associated with Non-Susceptibility to Carmine Cochineal (Dactylopius opuntiae)
Metabolomics, together with analytical methods and chemometric tools, point to new paths for selecting species that are resistant to pests and diseases. In this work, the forage palm species' metabolomic profile was investigated, and the relation between the chemical composition and resistance to Dactylopius opuntiae (carmine cochineal). The study was perfor
J. Braz. Chem. Soc.. Publicado em: 2021-08
-
9. Development of Analytical Method for Determination of Inorganic Constituents in Powder Refreshment Using Dilute Mineral Acids and Detection by ICP OES
An analytical method for multi-elementary determination in powder refreshment, based on sample digestion using dilute mineral acids and detection by inductively plasma coupled optical emission spectrometry (ICP OES) is proposed. Chemometric tools, such as fractional factorial design and principal component analysis (PCA) and hierarchical cluster analysis (HC
J. Braz. Chem. Soc.. Publicado em: 2021-07
-
10. FATTY ACIDS ANALYSIS AND CHEMOTAXONOMIC CONSIDERATIONS OF MALVOIDEAE (MALVACEAE) SPECIES
Previous researches showed that fatty acids analysis might be a useful tool to support the taxonomic investigation. In this approach the fatty acids content of ten Malvoideae species was analyzed and its chemotaxonomic significance has been investigated. The aerial parts of the species were collected in the Northeast of Brazil and their fatty acid methyl est
Quím. Nova. Publicado em: 2021-02
-
11. Evaluation of Brazilian Monovarietal Extra Virgin Olive Oils Using Digital Images and Independent Component Analysis
Digital images associated with chemometric tools, in a non-destructive approach, have been applied for the evaluation of the Brazilian monovarietal extra virgin olive oil. Independent component analysis (ICA) was employed in the image data evaluation of olive oils produced from distinctive olive varieties, and it was successful in highlighting the natural gr
J. Braz. Chem. Soc.. Publicado em: 2020-09
-
12. A multivariate approach to differentiate yerba mate (Ilex paraguariensis) commercialized in the southern Brazil on the basis of phenolics, methylxanthines and in vitro antioxidant activity
Abstract The consumption of yerba mate beverages is related to several health benefits. These desirable properties are mainly due to the bioactive compounds. However, the levels of those compounds are directly affected by factors such as geographical origin. This study aimed to use chemometrics to evaluate the antioxidant compounds of yerba mate (consumed as
Food Sci. Technol. Publicado em: 2020-09