A5008491530- Thermography and Photoacoustic Techniques
- Glass properties and applications
- Luminescence Properties of Advanced Materials
- Rare-earth and actinide compounds
- Photoacoustic and Ultrasonic Imaging
- Solid State Laser Technologies
- Phase-change materials and chalcogenides
- Calibration and Measurement Techniques
- Dental materials and restorations
- Magnetic and transport properties of perovskites and related materials
- Higher Education Teaching and Evaluation
- Iron-based superconductors research
- Optical and Acousto-Optic Technologies
- Magnetic Properties of Alloys
- Advanced Chemical Sensor Technologies
- Educational Practices and Policies
- Laser Material Processing Techniques
- Bone Tissue Engineering Materials
- Solid-state spectroscopy and crystallography
- Essential Oils and Antimicrobial Activity
- Spectroscopy Techniques in Biomedical and Chemical Research
- Transition Metal Oxide Nanomaterials
- Social Sciences and Policies
- Photorefractive and Nonlinear Optics
- Advanced Sensor Technologies Research
Universidade Estadual de Maringá
2015-2024
Abu Dhabi National Oil (United Arab Emirates)
2021-2024
National University of Distance Education
1999-2024
Hospital Regional Universitario de Málaga
2024
Fundación Hospital de Jove
2023
Universidad Politécnica de Madrid
2023
National Research Council Canada
2022
Institute for Learning Innovation
2022
University of Córdoba
2015-2018
Universidad Tecnológica de Panamá
2018
Curcumin was complexed with β-CD using co-precipitation, freeze-drying and solvent evaporation methods. Co-precipitation enabled complex formation, as indicated by the FT-IR FT-Raman techniques via shifts in peaks that were assigned to aromatic rings of curcumin. In addition, photoacoustic spectroscopy X-ray diffraction, disappearance band related rings, Gaussian fitting, modifications spectral lines, respectively, also suggested formation. The possible complexation had an efficiency 74%...
The optical band-gap energy of a nanostructured tungsten trioxide film is determined using the photoacoustic spectroscopy method under continuous light excitation. mechanism signal generation discussed. also computed by other methods. absorption coefficient as well three different crystal structures calculated first-principles Green’s function approach projector augmented wave method. theoretical study indicates that cubic structure shows good agreement with experimental data.
The aim of this study was to investigate the diffusion dynamics 25% hydrogen peroxide (H2O2) through enamel-dentin layers and correlate it with dentin's structural alterations. Micro-Raman Spectroscopy (MRS) Fourier Transform Infrared Photoacoustic (FTIR-PAS) were used measure spectra specimens before during bleaching procedure. H2O2 applied outer surface human enamel for 60 minutes. MRS measurements performed on inner or subsurface dentin. In addition, from dentin, passing dentin-enamel...
In this study the relations among nonbridging oxygen (NBO), optical properties, basicity, and color center formation in CaO–MgO aluminosilicate glasses were studied. Samples containing (in mol %) 35.9–57.5 of CaO, 16–27.7 Al2O3, 7.9–41.6 SiO2, 6.5–6.9 MgO measured by absorption excitation, luminescence, Raman spectroscopy. The results showed that when SiO2 content was increased, edge shifted toward lower wavelengths bonds between O2− ions cations became more covalent. These observations...
In a previous study, natural hydroxyapatite (HAp) from the bones of Brazilian river fish was calcined at 900 °C (4–12 h), and optical characterization using near infrared photoacoustic spectroscopy technique enabled establishment 8 h as best calcination time for nanostructure stabilization when milled in high-energy milling device [T. M. Coelho, E. S. Nogueira, W. R. Weinand, Lima, A. Steimacher, N. Medina, L. Baesso, C. Bento, J. Appl. Phys. 100, 094312 (2006)]. The wastes used were species...
Stability of potassium norbixinate and curcumin by microencapsulation with maltodextrin DE20 freeze-drying was evaluated as a function exposition to light, air, different pH, water solubility, in food applications. The best results were obtained microencapsulated 1:20, which, when vacuum-packed the presence natural showed color retention 78%, while 1:20 71%. Differential scanning calorimetry thermogravimetry provided an indication interaction between colorants maltodextrin. Photoacoustic...
"Calcium aluminosilicate" (CAS) and "low silica calcium (LSCAS) OH− free glasses have demonstrated a good potential for solid-state laser media luminophore hosts due to thermal, optical, mechanical properties. Some examples already been shown with Nd3+, Er3+, Ce3+, Ti3+ luminescent ions. In this work, Yb3+ rare-earth ions introduced into the two series of CAS LSCAS melted at 1600 °C in vacuum furnace optically characterized compared. Special attention has devoted both structural...
To investigate the chemical interactions between a high-viscosity glass ionomer cement (GIC) (KetacTM Molar Easymix, 3M ESPE, Seefeld, Bavaria, Germany) and human dentin. It was also analyzed dynamics of GIC setting mechanism based on time intervals required for mixed with dentin to achieve stability.Each constituent - powder (P) liquid (L) powdered (D), as well associations P+L, D+L, P+L+D in concentrations 29%, 50%, 65%, 78%, 82%, 92% were Fourier transform infrared (FTIR) Raman...
The effects of Nd2O3 doping on the thermal and mechanical properties vacuum melted, low silica, calcium aluminosilicate glasses are presented. For doped glasses, vitrification limit was found to correspond a maximum load 5 wt % Nd2O3. influence rare earth diffusivity, conductivity, Vickers hardness such that all these physical parameters decreased by roughly same amount, namely 8%, between undoped sample. dependence parameters, as function doping, strongly supports idea Nd3+ act network modifiers.
In this study, the characterization of optical properties natural hydroxyapatite (HAp) [Ca10(PO4)6(OH)2] is discussed. first stage experiment, HAp was processed from bones Brazilian river fish such as pintado (Pseudoplatystoma corruscans), jaú (Paulicea lutkeni), and cachara fasciatum). The were calcined at 900°C for different amounts time (4–12h) reduced to powder using two milling times (2 4h) in a high-energy ball mill, order determine best procedure obtaining nanostructured study. second...
We present our recent achievements of a glass able to produce smart white light combining phosphor with emitting diodes (LEDs). The combined emissions Ce3+-doped calcium aluminosilicate and the 405 nm LED using Commission Internationale de l’Éclairage 1931 chromatic diagram showed that this system presents an emission close ideal allows tunability. In addition, blue overlaps spectral range retinal photoreceptors involved in circadian responses. This UV is suitable for lights therefore may...
We report a theoretical model and experimental results for laser-induced local heating in liquids, propose method to detect quantify the contributions of photochemical Soret effects several different situations.The time-dependent thermal mass diffusion equations presence absence laser excitation are solved.The two can produce similar transients laser-on refractive index gradient, but very laser-off behavior.The effect, also called diffusion, reaction photochemically reacting aqueous...