Spectral
Mostrando 1-12 de 2608 artigos, teses e dissertações.
-
1. Impact of fuel quantity on luminescence properties of Sr3Al2O6:Eu by combustion synthesis
Abstract The photoluminescent behavior of Eu-doped Sr3Al2O6 obtained by highly efficient solution combustion synthesis is reported. In order to understand the influence of the fuel on the synthesis, the stoichiometric quantity and an excess of fuel were evaluated. By adjusting the amount of fuel, different luminescence responses were obtained, allowing europ
Cerâmica. Publicado em: 2023
-
2. 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
-
3. Characterization of Commercially Available Turmeric for Use in Pharmaceutical Products and Food Supplements
We addressed some physicochemical and biological differences in commercial turmeric, acquired from both handling pharmacies and stores selling natural products for quality assessment. For this, it was determined the melting point, antioxidant activity by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), antimicrobial activity via the agar disk-diffusion assay,
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
4. A Spectral Clustering Approach for the Evolution of the COVID-19 Pandemic in the State of Rio Grande do Sul, Brazil
ABSTRACT The aim of this paper is to analyse the evolution of the COVID-19 pandemic in Rio Grande do Sul by applying graph-theoretical tools, particularly spectral clustering techniques, on weighted graphs defined on the set of 167 municipalities in the state with population 10,000 or more, which are based on data provided by government agencies and other so
Trends in Computational and Applied Mathematics. Publicado em: 2022
-
5. Diffusive Metrics Induced by Random Affinities on Graphs. An Application to the Transport Systems Related to the COVID-19 Setting for Buenos Aires (AMBA)
ABSTRACT The aim of this paper is to apply the diffusive metric technique defined by the spectral analysis of graph Laplacians to the set of the 41 cities belonging to AMBA, the largest urban concentration in Argentina, based on public transport and neighborhood. It could be expected that the propagation of any epidemic desease would follow the paths determi
Trends in Computational and Applied Mathematics. Publicado em: 2022
-
6. Multimodal Neuromonitoring During Pediatric Cardiac Surgery
Abstract Introduction: Neuromonitoring (electroencephalogram [EEG] and cerebral oximetry) is essential for appropriate anesthesia and neuroprotection assessment during pediatric cardiac surgery. Methods: We describe the intraoperative pediatric multimodal and multiparametric neuromonitoring pattern of the software system Neuron-Spectrum (Kandel®) that con
Brazilian Journal of Cardiovascular Surgery. Publicado em: 2022
-
7. Rapid Recognizing the Producing Area of a Tobacco Leaf Using Near-Infrared Technology and a Multi-Layer Extreme Learning Machine Algorithm
A novel recognition method was put forward to identify the producing areas of the flue-cured tobacco leaves rapidly and non-destructively by using a near-infrared (NIR) spectrometer and a multi-layer-extreme learning machine (ML-ELM) algorithm. In contrast to traditional linear discriminant analysis (LDA) and extreme learning machine (ELM) algorithms, the ac
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
8. DESENVOLVIMENTO DE ACESSÓRIO PORTÁTIL DE CONTROLE DE TEMPERATURA PARA MEDIDAS ESPECTROSCÓPICAS
Temperature is a natural phenomenon that may modify the structure of chemical compounds and hence their properties. We aimed to develop a simple portable system based on the Peltier principle for spectral characterization of compounds with temperature-dependent structure. The device was constructed and adapted to three pieces of equipment: X-ray diffractomet
Química Nova. Publicado em: 2022
-
9. Friedelane Triterpenes with Cytotoxic Activity from the Leaves of Maytenus quadrangulata (Celastraceae)
Three new triterpenes, 3,4-seco-3,11β-epoxyfriedel-4(23)-en-3β-ol (1), friedelan-3α,11β diol (2), 7β,26-epoxyfriedelan-3a,7a-diol (3), a mixture of two new triterpenes 3α-hydroxyfriedelan-29-yl palmitate (4) and 3α-hydroxyfriedelan-29-yl stearate (5) and eleven known compounds were obtained from the hexane extract of Maytenus quadrangulata leaves. The
Journal of the Brazilian Chemical Society. Publicado em: 2022
-
10. Characterization and mechanical properties of one-part geopolymer based on a pure metakaolin
Abstract Geopolymers are amorphous silicate polymers that have been extensively studied due to their applications, scientific and technical relevance, and their potential as cement in substitution to Portland. Much of the focus has been in the use of precursors and aggregates that are rarely pure and homogeneous with the use of tailings being very common. Th
REM - International Engineering Journal. Publicado em: 2022
-
11. Impact of Air Pollutant on Heart Rate Variability in Healthy Young Adults
Abstract Background: Air pollution and sex independently affect cardiac autonomic control, which can be assessed by heart rate variability (HRV). The research hypothesis is that individuals exposed to low concentrations of pollution have higher cardiac autonomic modulation compared to those exposed to high concentrations and that women have better cardiac a
International Journal of Cardiovascular Sciences. Publicado em: 2022
-
12. PREDICTIVE MODELS OF CHLOROPHYLL CONTENT IN SUGARCANE SEEDLINGS USING SPECTRAL IMAGES
ABSTRACT Chlorophyll content is a widely used parameter for nutritional status diagnosis in sugarcane. This study aimed to develop a predictive model of chlorophyll content in sugarcane seedlings using spectral imagery analysis within the electromagnetic spectrum visible range. The experiment was carried out in a split-plot design, with two fertilization rat
Eng. Agríc.. Publicado em: 2021-08