Reflectometer
Mostrando 1-9 de 9 artigos, teses e dissertações.
-
1. A Low-Cost Video-Based Reflectometer for Selective Detection of Cu2+ Using Paper-Based Colorimetric Sensors
This paper presents a low-cost reflectometer for selective detection of Cu2+. The reflectometer is based on an emission light source using five light-emitting diodes at different wavelengths and a detector using a webcam. The samples were prepared using a filter paper-based colorimetric sensor with ascorbic acid-based quinoxaline derivative. Video analysis u
J. Braz. Chem. Soc.. Publicado em: 2017-12
-
2. Spatial and temporal patterns of soil water content in an agroecological production system
ABSTRACT: Spatial and temporal patterns of soil water content (SWC) can not only improve the understanding of soil water processes but also the water management in the field. The spatial distribution of SWC depends on the spatial variability of soil attributes, vegetation and landscape features. The aim of this study was to evaluate: i) the spatial and tempo
Sci. agric. (Piracicaba, Braz.). Publicado em: 2017-10
-
3. Excitação de ondas de helicon e de Alfvén em tokamak TCABR / Excitation of Helicon and Alfvén waves in tokamak TCABR
The objective of this work is to investigate the excitation of waves in a plasma using an antenna and to analyse the Alfvén resonances found. The Alfvén antenna heating system of the TCABR tokamak was designed to heat the plasma due to resonances. As the diodes of the toroidal field had burned down we used cleaning discharges, with low toroidal magnetic fi
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 04/04/2011
-
4. Experimental and numeric analysis of infiltration trenches in unsaturated zone / Análise experimental e numérica de trincheiras de infiltração em meio não saturado
This work assessed the hydraulic behavior of a experimental infiltration trench built at the EESC/USP and proposed a new sizing methodology for infiltration trench, for simulated events. In order to evaluate the hydraulic behavior experimental tests were taken to determine the infiltrated volume. The infiltrated volume was calculated through the difference b
Publicado em: 2009
-
5. ReflectÃmetro controlado por computador e sua aplicaÃÃo na detecÃÃo de hidrogÃnio com filmes finos de palÃdio e ouro/palÃdio
This work reports the development and implementation of a computer controlled optical reflectometer and use of the system for characterization of gold, palladium and gold-palladium thin films, with the latter two structures used as transducers for hydrogen detection. The system is designed with several parts actuated by stepper motors with an electronic inte
Publicado em: 2008
-
6. Projeto e construção de refletômetro seis portas alternativo - análise de desempenho / Design and construction of on alternative six port reflectometer - analysis of performance
Um circuito de seis-portas foi projetado aqui e foi construído para medir o coeficiente de reflexão complexo, de dispositivos de microondas. Foi construído com guia de ondas WR- 90 que operam na faixa de 8,2 - 12,4 GHz. Uma das vantagens deste seis-portas com respeito a outros sistemas que medem a mesma quantidade complexa é sua estrutura muito simples.
Publicado em: 2006
-
7. Identification of the Alfvén wave resonances in the TCABR tokamak by the microwave reflectometry
The experimental results on the Alfvén mode structure identification by the microwave reflectometry in TCABR tokamak are presented. The knowledge of the spatial spectrum of the excited waves is crucial for optimization of Alfvén wave plasma heating and noninductive current drive scenarios in tokamak plasmas. No less important is the possibility to use the
Brazilian Journal of Physics. Publicado em: 2004-12
-
8. Results of localized Alfvén wave heating in TCABR
Using two dimensional numerical codes, we show that the direct electron heating found with electron cyclotron emission (ECE) radiometry is related to local Alfvén wave resonances in Tokamak Chauffage Alfvén Brésilean (TCABR) plasmas. The m/N =1/2, 0/2 and 0/3 modes are dominant in the observed wave heating, due to Alfvén wave continuum absorption. In par
Brazilian Journal of Physics. Publicado em: 2004-12
-
9. Desempenho do reflectômetro no domínio do tempo na detecção de variações de umidade do solo. / Performance of a time domain reflectometer in the detection of soil moisture variations.
O objetivo do trabalho foi avaliar o desempenho do reflectômetro no domínio do tempo (TDR) comparativamente ao tensiômetro com manômetro de mercúrio (considerado como instrumento padrão), dando-se ênfase na sensibilidade de detecção de variações na umidade do solo sob condições de molhamento e secagem. Foi instalado um experimento em um solo cla
Publicado em: 2003