Electric Fields
Mostrando 1-12 de 219 artigos, teses e dissertações.
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1. SUPERCRITICAL EXTRACTION OF LYOPHILIZED STRAWBERRY ANTHOCYANINS WITH PULSED ELECTRIC FIELDS PRETREATMENT
The lyophilized strawberry anthocyanins were extracted using a supercritical extraction (SE) process. The effect of pulsed electric fields (PEF) as pretreatment and the influence of the addition of ethanol as a cosolvent on the percentage of extraction yield (EY) and the total anthocyanin concentration (TAC) were analyzed. The effect of PEF was evaluated at
Química Nova. Publicado em: 2022
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2. Electromagnetic Transients in Multiconductor Transmission Lines
Abstract The theory of multiconductor transmission lines is based on the principle of superposition. According to this principle, any electric or magnetic field can be represented as the sum of individual electric or magnetic fields. This theory is used to analyze and design electrical systems involving multiple conductors. In this work, the procedures for a
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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3. A Finite-Difference Time-Domain Formulation for Modeling Air Ionization Breakdown Streamers
Abstract A numerical model based on the finite-difference time-domain (FDTD) method is developed for calculating discharge currents and fields produced due air ionization between two electrodes. Electric conductivity σ of the ionized channel between two electrodes is calculated using non-linear equations, i.e., σ is obtained using functions of time. The fu
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2022
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4. Chemometric Evaluation of Poly(3-hexylthiophene) Electrochemical Aging Path as a Function of Electrochemical Synthesis Variables
Conductive polymers are versatile materials that can be applied in many different technology fields, especially green energy. They have several advantages, such as easy synthesis, low density, and cost. However, its electric conduction property is also related to material aging with great loss of their characteristics, limiting their applicability. The in-de
Journal of the Brazilian Chemical Society. Publicado em: 2022
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5. Comentário do Artigo “Sobre a Dinâmica de Partículas Carregadas em Campos Elétrico e Magnético Estáticos”
Resumo Neste trabalho ajustes são realizados em algumas equações do artigo “Sobre a Dinâmica de Partículas Carregadas em Campos Elétrico e Magnético Estáticos”, publicado nesta revista em 2017 [1]. Nossos cálculos mostram que (i) no caso particular 1, a trajetória circular da partícula carregada acontece em um quadrante diferente; (ii) no caso
Rev. Bras. Ensino Fís.. Publicado em: 22/08/2019
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6. Caracterización del proceso de fabricación de macroporos sobre sustrato de silicio por método electroquímico
ABSTRACT In the present work, the fabrication process of a set of micropores on crystalline silicon wafers manufactured through wet etching technique was studied. The influence of different control factors such as voltage, temperature and braking agent on the specific characteristics of formation was evaluated. An exhaustive analysis of the evolution of elec
Matéria (Rio J.). Publicado em: 19/07/2018
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7. A Hybrid Approach for Assessments of Equivalent Emission Sources and Electromagnetic Environments
Abstract This paper presents a method for equivalent emission source determination by application of LLAs (Large Loop Antennas). A review of different types of LLAs is carried out and their characteristics regarding emission source evaluation are emphasized. A hybrid technic is applied for obtaining the electric fields based on previous measurement of magnet
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2018-03
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8. FOTOELETROCATÁLISE EM SEMICONDUTORES: DOS PRINCÍPIOS BÁSICOS ATÉ SUA CONFORMAÇÃO À NANOESCALA
The science of semiconductors, essential in electronics, is pivotal also for the most active research fields of environmental science and engineering today - the development of solar energy conversions and advanced oxidation processes, exemplified by the harvesting of sun daylight to produce electric energy, environmentally friendly fuels and to clean up wat
Quím. Nova. Publicado em: 2018-03
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9. Emociones que emergen durante el análisis del conocimiento didáctico del contenido sobre el campo eléctrico
Abstract This study deals with the affective domain integrated with the personal and social history of teachers, and their beliefs and cognitive representations. This defines the shape of pedagogical content knowledge (PCK) when teachers teach and plan a concept. Our study analyzes the emotions declared by two high school teachers in a qualitative study on t
Ciênc. educ. (Bauru). Publicado em: 2018-01
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10. PREPARO DE AMOSTRAS ASSISTIDO POR CAMPO ELÉTRICO: FUNDAMENTOS, AVANÇOS, APLICAÇÕES E TENDÊNCIAS
Sample preparation is commonly considered a key step to achieve selective, sensitive, and reliable chemical analyses, particularly those involving complex matrices. Although the application of electric fields to improve the speed and efficiency of sample preparation methods has been proven, this approach is still considered to be state-of-the-art; hence, fur
Quím. Nova. Publicado em: 2015-09
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11. Semi-analytical formulation for a Unified Time and Frequency Antenna Characterization
AbstractThe definition of parameters that characterize the radiation of electric and magnetic fields for antennas in the time and frequency domain on an unified representation is proposed. The formulation uses a straightforward semi-analytical formulation that can be subsequently applied on the analysis of excited antennas for an arbitrary source with tempor
J. Microw. Optoelectron. Electromagn. Appl.. Publicado em: 2015-06
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12. Finite element modeling for buckling analysis of hybrid piezoelectric beam under electromechanical loads
A one-dimensional finite element model for buckling analysis of hybrid piezoelectric beams under electromechanical load is presented in this work. The coupled zigzag theory is used for making the model. The inplane displacement is approximated as a combination of a global third order variation across the thickness with an additional layer wise linear variati
Lat. Am. j. solids struct.. Publicado em: 2014-10