Excitation
Mostrando 1-12 de 1841 artigos, teses e dissertações.
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1. Carbon Dots from Pilosocereus gounellei for Fluorimetric Determination of Tannin in Tea Using a Flow-Batch System
In this study, xiquexique (Pilosocereus gounellei) native endemic cactus from the Brazilian semiarid was used for the first time as a natural carbon source (“green precursor”) for the synthesis of highly fluorescent carbon dots (CDs). These CDs were successfully used to develop a fast, low-cost, eco-friendly fluorescence method for the determination of t
Journal of the Brazilian Chemical Society. Publicado em: 2023
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2. Spectrofluorimetric Determination of Hydrochlorothiazide by a Carbon Dots-Based Probe via Inner Filtering Effect and Resonance Rayleigh Scattering
Synthesis of carbon dots (CDs) from natural resources not only enables green synthesis and production of environmentally friendly materials, but also provides a cost-effective probe as a fluorescence nanosensor. The proposed sensor introduces a unique one-pot hydrothermal CDs synthesis from alfalfa leaves, which is promising for sensing hydrochlorothiazide (
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. A High-Selectivity Bandpass Filter Using Dual-Mode Coupling Resonator
Abstract In this work, a new model of high selectivity dual-mode bandpass filter is presented. The proposed filter consists of a set of coupled lines with a dual-mode adjustable response in its design process. An improvement in selectivity is presented by combining the dual-mode element with a classic band rejection structure, thus making it possible to intr
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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4. Single Port Multimode Reconfigurable UWB-NB Antenna for Cognitive Radio Applications
Abstract In this paper, a compact, single port, multimode reconfigurable UWB-NB antenna with a novel feeding network is presented. The proposed antenna consists of a pentagonal-shaped monopole radiator, a beveled-shaped partial defected ground plane with a rectangular slot, and a reconfigurable bypass feeding network. The antenna realizes a wideband frequenc
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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5. A novel fluorescence sensor for the detection of chloride ion in artificial sweat and environmental water with nitrogen-doped graphene quantum dots
A new fluorescent detection route for chloride ion was designed with Nitrogen-doped graphene quantum dots (N-GQDs), which were prepared by a traditional hydrothermal method with citric acid as carbon source and urea as nitrogen source. The prepared N-GQDs solution was light yellow, and the freeze-dried solid was black. It emitted blue light under ultraviolet
Química Nova. Publicado em: 2022
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6. Incorporation of Fluorescent Dyes in Electrospun Chitosan/Poly(ethylene oxide)
Polymeric films have been increasingly investigated due to the ease of miniaturization and integration in several sensor devices. Films obtained from the electrospinning technique have a controlled diameter and homogeneity, and substances can be incorporated into the polymeric network. Electrospinning fiber of chitosan (Ch) and poly(ethylene oxide) (PEO) was
J. Braz. Chem. Soc.. Publicado em: 2021-05
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7. Impact of Continuing Education on the Quality of Blood Pressure Measurement
The properties of lanthanides allow them to be used as contrast agents for magnetic resonance imaging, thereby helping to differentiate between tissues, organs, and pathologies more efficiently. Lanthanides contain thermosensitive energy levels that aid identification of cancer and healthy cells. This work investigates the GdVO4 matrix obtained by the non-hy
Int. J. Cardiovasc. Sci.. Publicado em: 2021-02
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8. Er3+/Yb3+-Doped GdVO4 Obtained by the Non-Hydrolytic Sol-Gel Route and Potential Application as Up-Conversion Thermometer
The properties of lanthanides allow them to be used as contrast agents for magnetic resonance imaging, thereby helping to differentiate between tissues, organs, and pathologies more efficiently. Lanthanides contain thermosensitive energy levels that aid identification of cancer and healthy cells. This work investigates the GdVO4 matrix obtained by the non-hy
J. Braz. Chem. Soc.. Publicado em: 2021-02
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9. Blue Glow Sticks: Cinnamic Acids and Arylacrylonitriles with Liquid-Crystalline Properties and Highly Fluorescent
Five new π-conjugated chromophores derived from acrylic acid and acrylonitrile were synthesized and their thermal and photophysical behaviors were analyzed. They were designed and synthesized through Knoevenagel condensations between arylacetylenebenzaldehydes and a methylene group activated from cyanoacetic and malonic acids. The characterization of the ta
J. Braz. Chem. Soc.. Publicado em: 2021-01
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10. Synthesis of Sparse Arrays Based On CIGA (Convex Improved Genetic Algorithm)
Abstract In this paper, a novel hybrid algorithm on beam pattern synthesis of sparse arrays is proposed, which aims at minimizing the peak sidelobe level (PSLL). Sparse arrays can provide higher spatial resolution and relatively lower sidelobe than general arrays, but it is necessary to solve the multi-constraint problem of nonconvex nonlinear. Thus, we prop
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-12
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11. NANOMATERIAIS PLASMÔNICOS: PARTE I. FUNDAMENTOS DA ESPECTROSCOPIA DE NANOPARTÍCULAS E SUA RELAÇÃO COM O EFEITO SERS
We perform an analysis of plasmonic nanomaterials in a two part review, the first of which constitutes the present work. Here, attention is given to the fundamentals of metal nanoparticle optical properties. It is discussed the principles regarding the excitation of localized surface plasmon modes in nanostructures of different sizes, shapes and surrounding
Quím. Nova. Publicado em: 2020-12
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12. Metamaterial-Fractal-Defected Ground Structure Concepts Combining for Highly Miniaturized Triple-Band Antenna Design
Abstract In this paper, a novel method is proposed to increase the gain and radiation efficiency of a compact patch antenna. By employing a combination of three efficient techniques, we have developed a multi-resonance L-DGS antenna with a high gain of 5 dB and an efficiency of 99.6%. Furthermore, a novel compact Double Negative metamaterial unit cell and it
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2020-12