Spin Diffusion
Mostrando 1-12 de 76 artigos, teses e dissertações.
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1. Analysis of thin bifacial silicon solar cells with locally diffused and selective back surface field
The aim of this work is to present the development and comparison of thin n+pp+ industrial bifacial silicon solar cells produced with the local screen-printed Al back surface field (BSF) to those with the selective BSF doped with aluminum-boron. To produce solar cells with selective BSF, the boron diffusion based on spin-on dopant was introduced in the proce
Mat. Res.. Publicado em: 09/09/2014
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2. Molecular dynamics and formation of domains in block copolymers studied by high and low resolution NMR / Dinâmica molecular e formação de domínios em copolímeros em bloco estudados por RMN de alta e baixa resolução
The main objective of this dissertation is the use of NMR methods to characterize the phase separation and, to some extent, the dynamics of the molecular segments in block copolymers. In the first part, NMR Spin Diffusion methods were explored in order to evaluate their performance as well as the main experimental difficulties. For that, a reference tri-bloc
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 09/04/2012
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3. Otimização e comparação de processos para formação do campo retrodifusor com boro em células solares
The aim of this thesis was to develop and compare methods for the formation of the back surface field and emitter with boron using n-type and p-type solar-grade Si-Cz wafers as well as analyze and optimize a manufacturing process of solar cells with structure n+pp+ and back surface field formed by boron. The highly doped p+ region was formed by spin-on depos
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 27/03/2012
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4. Efeitos de terpenos nas membranas de estrato córneo estudados por ressonância paramagnética eletrônica / Effects of terpenes on the stratum corneum membranes studied by electron paramagnetic resonance
The interaction of the skin penetration enhancers DL-menthol, -terpineol, 1,8-cineole and (+)-limonene with membranes of the uppermost skin layer, the stratum corneum (SC) and with multilamellar vesicles from 1,2-dipalmitoyl-sn-glycero-3-phosphaticylcholine (DPPC)is investigated by electron paramagnetic resonance (EPR) spectroscopy using spin-labeled
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 18/02/2008
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5. Effect of polysaccharide capsule of the microalgae Staurastrum iversenii var. americanum on diffusion of charged and uncharged molecules, using EPR technique
The existence of a mucilaginous envelope, sheath or capsule is usual in many desmids, but few data concerning its function are available. Previous studies of the transport function and permeation of molecules through the algae capsules were done using the algae Spondylosium panduriforme and Nephrocytium lunatum, the Electron Paramagnetic Resonance (EPR) tech
Brazilian Journal of Physics. Publicado em: 2006-03
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6. Analysis of nuclear relaxation in granular systems
The longitudinal nuclear magnetic relaxation time, T1, of powdered samples was analyzed following the theory proposed by Browstein and Tarr to explain the T1 reduction of water confined in biological cells and the proposed by Rabbani and Edmonds where the molecular diffusion in liquids is substituted by spin diffusion to interpret the T1 behavior in solid pa
Brazilian Journal of Physics. Publicado em: 2006-03
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7. Interações entre bicamadas lipídicas e interfaces hidrofóbicas / Interactions between lipid bilayers and hydrophobic interfaces
Determinations of surface tension (γ) at the air--water interface, contact angles (Θ), and in and ex-situ ellipsometric mean thickness (d) were used to study the interaction between dioctadecyldimethylammonium bromide (DODAB) small vesicles and spin-coated polystyrene sulfate (PSS) films on silicon wafers. Upon the adition of NaCl (50 mM final conc
Publicado em: 2003
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8. Aplicação da espectroscopia de ressonância magnética nuclear para estudos de difusão molecular em líquidos: a técnica DOSY
Diffusion coefficients provide uniquely detailed and easily interpreted information on molecular organization and phase structure. They are quite sensitive to structural changes, and to binding and association phenomena, in particular for liquid colloidal or macromolecular systems. This paper describes the principles of diffusion measurements in liquids by p
Química Nova. Publicado em: 2002-11
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9. Um estudo da interação entre ions aromaticos e micelas, em cristais liquidos liotropicos nematicos e em soluções isotropicas, por ressonancia magnetica nuclear
The interaction between ions and the electric double layer of micelles and biological membranes depends on a balance between the electrostatic torces and the hydrophobic effect. In this work, the interaction of the ions anilinium, benzoate, p-toluenesulfonate and benzenesulfonate with micelles was studied in nematic Iyotropic liquid crystals and isotropic so
Publicado em: 2001
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10. Propriedades Ópticas de Semicondutores Orgânicos à Base de Polímeros Emissores de Luz / Optical proprieties of organic semiconductors based on light emitting polymers.
In this work, we studied the optical proprieties of absorption and emission of luminescent conjugated polymers based on poly(p-phenylene vinylene) (PPV). This material was processed in thin films by casting, spin-coating, self-assembled (SA) e Langmuir-Blodgett (LB) techniques, available in the Grupo de Polímeros Bernhard Gross, where the samples were chara
Publicado em: 2001
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11. Simulação da cinetica do crescimento de pontos quanticos semicondutores em vidros
The growth kinetics of pontos quânticos (QD) in a vitreous matrix is important because its linear and non linear optical properties depends on their sizes and dispersion. QD s are fabricated by melting the semiconductors elements together with the vitreous matrix. After melting, the glass is submitted to a thermal treatment to lower temperatures, (500- 600�
Publicado em: 2000
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12. Nuclear magnetic resonance study of proton conductor HPb2Nb3O10. nH2O. / Estudo por Ressonância Magnética Nuclear do Condutor Protônico HPb2Nb3O10. nH2O.
The protonic conductor HPb2Nb3O10. nH2O , was studied by pulsed Nuclear Magnetic Resonance (NMR) of ANTPOT.1H. The temperature dependence of the spin-lattice relaxation rate (1/T IND.1) and line width, reflect the mobility of the protonic species present in this material. The onset of ionic and molecular motions produces a strong narrowing of the line at tem
Publicado em: 1998