J R Curves
Mostrando 1-12 de 128 artigos, teses e dissertações.
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1. Strong Stability Preserving Runge-Kutta Methods Applied to Water Hammer Problem
ABSTRACT The characteristic method of lines is the most used numerical method applied to the water hammer problem. It transforms a system of partial differential equations involving the independent variables time and space in two ordinary differential equations along the characteristics curves and then solve it numerically. This approach, although showing gr
Trends in Computational and Applied Mathematics. Publicado em: 2022
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2. Atomic Absorption Spectrometry as an Alternative to Determine the Presence of Gold Nanoparticles on or in Silica Matrix
Two different gold-silica-based nanomaterials were prepared: (i) silica-supported gold nanoparticles (AuNP/SiO2); and (ii) gold-silica core-shell nanoparticles (AuNP@SiO2). Three strategies for sample treatment (S), consisting in acid treatments, were employed: (S1) HNO3; (S2) HNO3 + HCl; and (S3) HF + HNO3 + HCl, applying microwave oven digestion for S2 and
Journal of the Brazilian Chemical Society. Publicado em: 2022
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3. Universal Approximators: New Approach for the Curve Fit of the COVID-19 Infected Population
ABSTRACT Fuzzy systems that include Takagi-Sugeno inference method with linear outputs, are widely known to have the ability to uniformly approximate any polynomial with high precision and, as a consequence, any continuous function, by applying the approximation theorem of Weierstrass. There is one more advantage for these methods which is to obtain an expli
Trends in Computational and Applied Mathematics. Publicado em: 2022
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4. Profiling the Cymbopogon nardus Ethanol Extract and Its Antifungal Potential against Candida Species with Different Patterns of Resistance
The essential oil of Cymbopogon nardus, citronella, has been extensively studied. However, the chemical and biological properties of the ethanolic extract (EE) of C. nardus have not been evaluated. The aim of this study was to characterize the chemical composition of the EE of C. nardus and its active fraction (FrD). Moreover, the cytotoxic and antifungal pr
J. Braz. Chem. Soc.. Publicado em: 2020-09
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5. Modeling and thermodynamic properties of ‘bacaba’ pulp drying
RESUMO Objetivou-se secar a polpa de bacaba em diferentes condições térmicas, ajustar diferentes modelos matemáticos às curvas de desidratação e calcular os coeficientes de difusão, a energia de ativação e as propriedades termodinâmicas do processo. Frutas da bacabeira foram despolpadas para a obtenção da polpa que foi secada nas temperaturas de
Rev. bras. eng. agríc. ambient.. Publicado em: 12/08/2019
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6. Açai juice as contrast agent in MRCP exams: qualitative and quantitative image evaluation
Abstract This works aims to assess images obtained with administration of açai juice as compared to a manufactured standard iron oxide-based contrast employed as negative oral agents in Magnetic Resonance Cholangiopancreatography (MRCP), employing qualitative and quantitative evaluation. The research was developed with 64 patients submitted to MRCP exams (o
Braz. arch. biol. technol.. Publicado em: 13/05/2019
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7. 99mTc-DTPA Diuretic Renography with 3 hours late output fraction in the evaluation of hydronephrosis in children
ABSTRACT Objective: Dynamic renal scintigraphy complemented by late gravity assisted postvoid images to 60 minutes is a frequently used diagnostic test in the evaluation of hydrone- phrosis. The objective of this study is to evaluate the effectiveness in acquiring images at 180 minutes to calculate the late output fraction (LOF) of 99mTc-DTPA in the diagno-
Int. braz j urol.. Publicado em: 2018-06
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8. AVALIAÇÃO DA ADSORÇÃO E ESTUDO ELETROQUÍMICO DE CÉLULAS SOLARES PRODUZIDAS COM TiO2 E CORANTE EXTRAÍDO DO HIBISCUS
Dye-sensitized solar cells using natural dyes have lower cost when compared to ruthenium-based dyes. This paper aims to evaluate, electrochemically, solar cells composed of TiO2 with dye extracted from the Hibiscus(var. Sabdariffa) and propose an adsorption model capable of predicting the adsorption mechanism of the dye on the semiconductor surface. The char
Quím. Nova. Publicado em: 2018-05
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9. Development and Validation of a Rapid and Reliable RP-HPLC-PDA Method for the Quantification of Six Diterpenes in Copaifera duckei, Copaifera reticulata and Copaifera multijuga Oleoresins
Oleoresins from Copaifera species are extensively used in folk medicine in Brazil, which are employed mainly in the production of cosmetic formulations in Brazil, North America and Europe. Considering the lack of validated analytical methods for the analyses of diterpenes in Copaifera oleoresins, it was developed a validated and reliable reversed-phase high-
J. Braz. Chem. Soc.. Publicado em: 2018-04
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10. DETERMINAÇÃO DE FOSFATO EM REFRIGERANTES UTILIZANDO UM SCANNER DE MESA E ANÁLISE AUTOMATIZADA DE DADOS: UM EXEMPLO DIDÁTICO PARA ENSINO DE QUÍMICA
We propose here the quantification of the phosphorus content in cola drinks by molybdenum blue method. Molybdenum blue method was carried out in the wells of a microplate, where method miniaturization represents reduction in reagents required, improved safety, reduced waste stream, and increased sample throughput. The phosphate concentration was determinate
Quím. Nova. Publicado em: 2017-08
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11. Acute but not chronic metabolic acidosis potentiates the acetylcholine-induced reduction in blood pressure: an endothelium-dependent effect
Metabolic acidosis has profound effects on vascular tone. This study investigated the in vivo effects of acute metabolic acidosis (AMA) and chronic metabolic acidosis (CMA) on hemodynamic parameters and endothelial function. CMA was induced by ad libitum intake of 1% NH4Cl for 7 days, and AMA was induced by a 3-h infusion of 6 M NH4Cl (1 mL/kg, diluted 1:10)
Braz J Med Biol Res. Publicado em: 04/12/2015
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12. CURRENT-VOLTAGE CURVES FOR TREATING EFFLUENT CONTAINING HEDP: DETERMINATION OF THE LIMITING CURRENT
Abstract Membrane separation techniques have been explored for treating industrial effluents to allow water reuse and component recovery. In an electrodialysis system, concentration polarization causes undesirable alterations in the ionic transportation mechanism. The graphic construction of the current voltage curve is proposed for establishing the value of
Braz. J. Chem. Eng.. Publicado em: 2015-12