Light Emitting Diode
Mostrando 1-12 de 100 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. Light-Assisted Batch Injection Analysis of Glucose Exploiting a p-n-Homojunction Based on Cu2O
This work describes the development of a photoelectrochemical sensor for glucose quantification exploiting a light assisted-batch injection analysis (BIA) cell. A light-emitting diode (LED) lamp was employed to control the incidence of light on the p-Cu2O/n-Cu2O/fluorine-doped tin oxide (FTO) photoactive platform in BIA cell. The p-Cu2O/n-Cu2O/FTO platform w
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Determination of 3,4,5-Trihydroxybenzoic Acid Exploiting a Visible-Light-Driven Photoelectrochemical Platform: Application in Wine and Tea Samples
The present work is based on the development and application of a photoelectrochemical method for the amperometric determination of 3,4,5-trihydroxybenzoic acid in different samples. The method is based on the use of a photoelectrochemical platform based on a glass slide coated with fluorine-doped tin oxide, which has been modified with cadmium sulfide and p
Journal of the Brazilian Chemical Society. Publicado em: 2022
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4. Oxigênio no contexto da COVID-19: o que sabemos sobre a molécula que respiramos e o papel central da química
OXYGEN IN THE COVID-19 CONTEXT: WHAT WE KNOW ABOUT THE MOLECULE WE BREATHE AND THE CENTRAL ROLE OF CHEMISTRY. In this work, the role of chemistry in the coronavirus disease 2019 (COVID-19) pandemic is highlighted through the medical oxygen supply crises in Brazil, as an example of oxygen utility in health. Starting from oxygen chemical characterization, the
Química Nova. Publicado em: 2022
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5. Thermal, structural and optical properties of magnetic BiFeO3 micron-particles synthesized by coprecipitation method: heterogeneous photocatalysis study under white LED irradiation
Abstract Bismuth ferrite, BiFeO3 (BFO) prepared via a coprecipitation method, was used as an effective photocatalyst for the degradation of methylene blue (MB) using a white light-emitting diode (LED-50 W) lamp. The as-prepared material was characterized by TGA, XRD, SEM-EDX, FTIR, and UV-vis-DRS techniques. The effects of experimental key parameters such as
Cerâmica. Publicado em: 2022
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6. PhotoMetrix UVC: A New Smartphone-Based Device for Digital Image Colorimetric Analysis Using PLS Regression
A novel free PhotoMetrix UVC is proposed for both the operation of a universal serial bus video camera (UVC) and multivariate image analysis, allowing a full solution for point-of-use analysis. A UVC was placed in an open-source 3D-printed chamber illuminated by a white light-emitting diode (LED) with controlled intensity of light. The digital images capture
J. Braz. Chem. Soc.. Publicado em: 2021-03
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7. AN EVALUATION OF THE THERMAL AND LUMINOUS ENVIRONMENT OF LAYING HEN AVIARIES EQUIPPED WITH LIGHT-EMITTING DIODE AND COMPACT FLUORESCENT LAMPS AND THEIR EFFECTS ON PRODUCTION AND EGG QUALITY
ABSTRACT The thermal and luminous conditions in aviaries affect the production and quality of eggs. Thus, the aim of the present study was to evaluate the thermal and luminous environment of commercial laying hen aviaries equipped with compact fluorescent (CF) and light-emitting diode (LED) lamps and their influence on egg production and quality. The study w
Eng. Agríc.. Publicado em: 2021-02
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8. A Calix[4]arene-Functionalized Perylene Imide and Its Luminescence Properties
In this study, new perylene-derived molecules were synthesized as perylene-3,4,9,10-tetracarboxylic acid monoanhydride monopotassium carboxylate 1; N-(3-propanol)perylene-3,4,9,10-tetracarboxylic-3,4-(monoimide)anhydride-9,10-acid potassium carboxylate 2; 5,11,17,23-tetra(tert-butyl)-25,27-bis(3’-bromopropoxy)-26,28-(dihydroxy)calix[4]arene 3; 5,11,17,23-t
J. Braz. Chem. Soc.. Publicado em: 2020-11
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9. Errata: Infrared Light-Emitting Diode (LED) Effects on Orthodontic Tooth Movement
Abstract Objective: To examine the current literature behind the evolution of mitral valve surgery techniques and their impact on patient outcomes. Methods: An electronic literature search among major databases was performed (PubMed, Embase, Scopus, Cochrane, and Google scholar). All the relevant articles were screened and identified to be included in th
Braz. Dent. J.. Publicado em: 2020-08
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10. Substituição de lâmpadas fluorescentes por light emitting diode (LED) em uma instituição de ensino: preocupação ambiental, energética e econômica
RESUMO As lâmpadas fluorescentes (LFs) podem causar sérios problemas ambientais e à saúde humana. Tal fato se deve à presença de mercúrio em sua constituição e, quando descartadas inadequadamente, podem ocasionar a contaminação do solo, do ar e da água. Já as lâmpadas light emitting diode (LED), além de mais econômicas e com maior vida útil
Eng. Sanit. Ambient.. Publicado em: 09/09/2019
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11. Estudo das propriedades do Diodo Emissor de Luz (LED) para a determinação da constante de Planck numa maquete automatizada com o auxílio da plataforma Arduíno
Resumo No presente artigo, apresenta-se o método experimental de determinação da constante de Planck, uma das constantes físicas fundamentais, através do estudo das propriedades quânticas e ondulatórias do diodo emissor de luz (LED) numa maquete experimental automatizada, que contém um circuito eletrônico ligado a um computador utilizando o protocol
Rev. Bras. Ensino Fís.. Publicado em: 09/09/2019
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12. BIOPHOTONICS: ACCLIMATION OF PRE-SPROUTED SUGARCANE SEEDLINGS IN PROTECTED ENVIRONMENT
ABSTRACT Sugarcane is considered one of the main alternatives for biofuel production and an important product of Brazilian agriculture, so it is indispensable to adopt new techniques for its cultivation and management. Thus, the present study aimed to evaluate the effect of the quality of supplemental lighting, based on light-emitting diode (LED), on the acc
Eng. Agríc.. Publicado em: 12/08/2019