Electrons Emission
Mostrando 1-12 de 45 artigos, teses e dissertações.
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1. A Sensitive Voltammetric Determination of Anti-Parkinson Drug Pramipexole Using Titanium Dioxide Nanoparticles Modified Carbon Paste Electrode
In this study, a facile sensor based on TiO2 nanoparticles modified carbon paste electrode was developed for voltammetric determination of pramipexole in pharmaceutical formulations and biological samples. Surface of the fabricated electrode have been characterized using field emission scanning electron microscopy. Under the optimized experimental conditions
J. Braz. Chem. Soc.. Publicado em: 2017-04
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2. Efeito de interface nas propriedades ópticas de pontos quânticos de InP/GaAs / Interface effect on the optical properties of InP/GaAs quantum dots
We studied the effect of different interface conditions on the optical properties of InP/GaAs self-assembled quantum dots grown by chemical beam epitaxy in the Stranskii-Krastanov mode. InP/GaAs quantum dots is expected to present type II band alignment, and only electrons are confined, whereas the holes are localized in the GaAs layers around the quantum do
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/08/2012
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3. Desenvolvimento de um sistema de aquisição de dados e de controle para a realização de ensaios de emissão eletrônica na câmara de ultra alto vácuo / Development of a data acquisition and control system for electron emission tests in an ultra high vacuum chamber
Foi projetado e desenvolvido um sistema de aquisição de dados e controle para viabilizar, de forma automatizada, a caracterização de emissividade eletrônica em catodos frios, por meio da utilização da câmara de ultra alto vácuo do Departamento de Semicondutores, Instrumentação e Fotônica - DSIF, da Faculdade de Engenharia Elétrica e Computação
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 02/07/2012
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4. Uncooled detectors of continuum terahertz radiation
THz continuum spectral photometry has new and unique applications in different civil and military areas presenting a number of distinctive advantages on the well known microwaves or mid- to near-infrared technologies. THz sensing is essential to investigate the emission mechanisms by high energy particle acceleration processes. Technical challenges appear to
Journal of Microwaves, Optoelectronics and Electromagnetic Applications. Publicado em: 2011-06
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5. Coherent and incoherent radiation from free-electron lasers with an axial guide field
The spontaneous and induced emission from a free-electron laser is treated for the case in which an axial magnetic field is imposed in addition to the helical, axially periodic wiggler magnetic field. The classes of possible single-particle trajectories in this configuration are discussed, and the results are applied to a calculation of the incoherent radiat
Publicado em: 2011
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6. Optimizing the e-beam profile of a single carbon nanotube field emission device for electric propulsion systems
Abstract: Preliminary studies on field emission (FE) arrays comprised of carbon nanotubes (CNT) as an electron source for electric propulsion system show remarkably promising results. Design parameters for a carbon nanotube (CNT) field-emission device operating on triode configuration were numerically simulated and optimized in order to enhance the e-beam fo
J. Aerosp. Technol. Manag.. Publicado em: 2010-04
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7. Investigação da Difusão de Portadores em Pontos Quânticos Sob Campo Elétrico Externo Por Meio da Varredura da Microluminescência
In this work, we present the study of energy transfer processes between self-assembled quantum dots (QDs) of InAs in GaAs layers within an intrinsic region of a p-i-n device. These p-i-n structures are assembled with electrical contacts providing the application of an electrical potential. The three samples used have diferent layer spacing and barrier size b
Publicado em: 2009
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8. Ordem-desordem: uma avaliação estrutural do Ba(ZrxTi1-x)O3 / Order-disorder: an evaluation structural of Ba(ZrxTi1x)O3
This work have as aim, the synthesis of ceramic powders of Ba(ZrxTi1x)O3 (x = 0, 0.25, 0.50, 0.75 and 1) by the polymeric precursor method and investigate the degree of structural order-disorder of these systems by different characterization techniques, such as: thermogravimetric analysis (TA), differential thermal analysis (DTA), X-ray diffraction (XRD), Ra
Publicado em: 2009
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9. Contribuição para a sintese de diamante nanocristalino com dopagem de boro / Contribution towards the synthesis of boron doped nanocrystalline diamonds
This thesis presents a study of the growth and characterization of nano crystalline diamonds produced by the hot-filament chemical vapor deposition (CVD) with the introduction of boron during the growth process. Our objective was to produce samples with good electrical properties for field induced emission of electrons (FEE) to the vacuum. Characterization o
Publicado em: 2008
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10. Study of the phenomenon of electron emission by electric field from carbon nanotubes / Estudo do fenomeno de emissão de eletrons por campo eletrico em nanotubos de carbono
Materiais emissores de elétrons são extremamente importantes no ramo da micro e nano eletrônica, como por exemplo, em displays, microscópios eletrônicos, sensores de pressão. Para essas aplicações, podem ser usados catodos frios, ou seja, materiais que não necessitam ser aquecidos para emitirem elétrons. Através da aplicação de um campo elétric
Publicado em: 2008
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11. Partial caracterization of dipyridamole electrooxidation products in acetonitrile and acid aqueous medium / Caracterização parcial dos produtos de eletrooxidação do dipiridamol em acetonitrila e em meio aquoso ácido
In this work the products obtained in the eletrooxidation reactions of 2,6- bis(diethanolamino)-4,8-dipiperidinopyrimido-[5,4-d] pyrimidine (Dipyridamole) were studied. Dipyridamole is a drug that induce the coronary vasodilatation mostly used in Nuclear Cardiology in different techniques based on acquisition and image processing ( perfusion heart cintilogra
Publicado em: 2008
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12. Computational Modeling of field emission tips / Modelamento computacional de ponteiras de emissão de campo
This work aims to study the electrical behavior of a field emission tip, shaped in the form hemisphere on a post, through computational resources (simulations). We chose the Ansys commercial software that uses the finite element methods in the analyses of the physical phenomena to obtain the electric field in the surface of the tip. After that, a computation
Publicado em: 2007