26 documents found, page 1 of 3
Engineering Pb-free relaxor ferroelectric thin films for low voltage energy sto...
Ribeiro, Duarte J. M.; Nair, Surya Kiran Puravankara; Ravikumar, Jayakrishnan AMpattu; Oliveira, João; Magagnin, Grégoire; Albertini, DavidPulsed power technologies demand dielectric capacitors that possess a high energy storage density and efficiency at low applied electric fields/voltages. In this work, we engineered the morphology of lead-free \( 0.85[0.6\text{Ba}(\text{Zr}_{0.2}\text{Ti}_{0.8})\text{O}_3–0.4(\text{Ba}_{0.7}\text{Ca}_{0.3})\text{TiO}_3]–0.15\text{SrTiO}_3 \) (BZCT–STO) epitaxial thin films, fabricated using the pulsed laser dep...
Development and optical characterisation of agarose-based phantoms mimicking bi...
Fernandes, Filipa Gracinda Silva; Pereira, Mário R.; Soares, Delfim; Fonseca, A. M.; Costa, Daniel; Silva, Filipe Samuel; Sousa, NunoSearching for materials that accurately mimic the optical properties of biological tissues is essential, particularly for transcranial photobiomodulation (PBM) research, where it is necessary to comprehend how light propagates through the head tissues. In this research, we characterised, in the 500-1200 nm range, the transmittance spectra of porcine tissues (skin, muscle, cranium, brain, and cerebellum) and dif...
High Piezoelectric Output Voltage from Blue Fluorescent N,N-Dimethyl-4-nitroani...
Baptista, Rosa Maria Ferreira; Silva, Bruna; Oliveira, João; Bayzi Isfahani, Vahideh; Almeida, Bernardo; Pereira, Mário R.; Cerca, Nuno; Castro, CidáliaN,N-dimethyl-4-nitroaniline is a piezoelectric organic superplastic and superelastic charge transfer molecular crystal that crystallizes in an acentric structure. Organic mechanical flexible crystals are of great importance as they stand between soft matter and inorganic crystals. Highly aligned poly-l-lactic acid polymer microfibers with embedded N,N-dimethyl-4-nitroaniline nanocrystals are fabricated using th...
LiDAR – Tudo na luz é informação
Romanyshyn, Nazar; Duarte, M; Cunha, N. F.; Pereira, Mário R.; Vasilevskiy, MikhailO que têm em comum o caminho da lua no mar e a condução autónoma de veículos? A reflexão difusa da luz em superfícies rugosas e materiais heterogêneos é responsável pela visibilidade de objetos que não conseguiríamos ver de acordo com a lei de Snell. O mesmo fenómeno ótico também está na base do funcionamento de sensores remotos chamados LIDARs (abreviação de Light Detection And Ranging) que surgiram nos anos 6...
Assessment of zirconia fluorescence after treatment with immersion in liquids, ...
Volpato, Claudia A. M.; Carvalho, Óscar Samuel Novais; Volpato, Guilherme M.; Fredel, Márcio C.; Silva, Filipe Samuel; Pereira, Mário R.The aim of this study was to evaluate the fluorescence of white zirconia immersed in coloring and fluorescence liquids subjected to glass infiltration and aging. Sixty zirconia discs were machined and divided into groups. Ten discs received no treated before sintering (NT group), ten discs were immersed in a coloring liquid (A2 group), and ten discs were immersed in a fluorescent liquid (F group). The other thi...
Squaraine dyes as serum albumins probes: synthesis, photophysical experiments a...
Gomes, Vanessa Sofia Dias; Boto, Renato E. F.; Almeida, Paulo; Coutinho, Paulo J. G.; Pereira, Mário R.; Gonçalves, M. Sameiro T.; Reis, Lucinda V.Three barbiturate squaraine dyes derived from indolenine or benzothiazole, with different barbituric acid derivatives were prepared, characterized and photophysically evaluated by standard spectroscopic methods. As expectable for squaraines, these dyes showed narrow and intense absorption and emission bands in the Vis/NIR region. The interaction of synthesized dyes with bovine and human serum albumins (BSA and ...
Materiais para a energia: Apontamentos
Pereira, Mário R.Apontamentos disponibilizados aos alunos de Mestrado em Ciências do Ambiente no âmbito da Unidade Curricular Materiais para a Energia - ramo Energia, lecionada no primeiro ano, segundo semestre do seu plano curricular.
Evaluation of the color and translucency of glass-infiltrated zirconia based on...
Volpato, Claudia Angela Maziero; Carvalho, Oscar Samuel Novais; Pereira, Mário R.; Silva, Filipe SamuelStatement of problem. Infiltrated zirconia has promising mechanical properties. However, information about its optical behavior is scarce.Purpose. The purpose of this in vitro study was to evaluate the color and translucency of zirconia submitted to infiltration and aging.Material and methods. Sixty zirconia disks were machined. Ten disks received no treatment (NT group), 10 disks were immersed in a coloring li...
Translucency, contrast ratio and fluorescence of esthetic materials
Kauling, A. E. C.; Volpato, C. A. M; Carvalho, Óscar Samuel Novais; Pereira, Mário R.; Guth, J. F.This study evaluated the translucency, contrast ratio and fluorescence of resin nanoceramic and zirconia materials employed for manufacturing of the indirect restorations.
Fluorescence of natural teeth and restorative materials, methods for analysis a...
Volpato, Claudia Angela Maziero; Pereira, Mário R.; Silva, Filipe SamuelObjective: This review integrates published scientific information about the fluorescence of natural teeth, dental resins and ceramics, and the main methods of analysis and quantification presented in the literature. Overview: Fluorescence is an emission of light (photons) by a substance that has absorbed light of higher energy. In natural teeth, it is more intense in the dentin than in the enamel and presents ...