Electronic Transport
Mostrando 25-36 de 125 artigos, teses e dissertações.
-
25. Efeitos da modulação de interferência quântica nas propriedades de transporte eletrônico em nanofitas armchair de Grafeno: Pseudo-spintrônica e análogo relativístico de Klein / Modulation effects of quantum interference in the electronic transport properties of armchair graphene nanoribbons: Pseudo-spintronics and Kleins similar relativistic
No presente trabalho, temos estudado o transporte eletrônico quântico em fitas de grafeno com bordas tipo armchair (FGA). Estas fitas são caracterizadas por apresentar um comportamento semicondutor ou metálico segum a largura que adote. A presença de uma barreira de potencial na FGA gera um deslocamento da estrutura de banda na região do potencial, pos
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/11/2009
-
26. Transporte eletrônico em super-redes semicondutoras: fingerprints de acoplamento, confinamento e assimetria em curvas de densidade de corrente / Electronic transport in semiconductor super-networks: fingerprints of engagement, containment and asymmetry in the current density curves
Neste trabalho fazemos um estudo sistemático do transporte eletrônico coerente em curvas de J(Vex) no regime balístico, de Super-Redes semicondutoras (SRs) baseadas em Heteroestruturas de GaAs/AlGaAs. Nosso objetivo principal é identicar os Fingerprints de connamento e acoplamento em curvas de corrente-voltagem, induzidos pela assimetria do sistema quand
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 05/06/2009
-
27. Ruido no transporte eletronico em sistemas mesoscopicos / Noise in the electronic transport in mesoscopic systems
This dissertation describes the fundamental caracteristics of mesoscopic conductors, and the origins and properties of the sources of noise in conductors. Firstly, we describe the noise through different methods and emphasize the properties of each kind of noise. In the following, we present the scattering approach for coherent phase conductors, which allows
Publicado em: 2009
-
28. Study of oxygen reduction reaction in acidic media on platinum and palladium electrocatalysts supported on carbon / Estudo da reação de redução de oxigênio em meio ácido em eletrocatalisadores de platina e paládio dispersos em carbono
Oxygen reduction reaction (ORR) on platinum-palladium electrocatalysts supported on carbon was studied in H2SO4 electrolyte. The structure of the catalysts was characterized by XRD (X-ray diffractometry) and the composition was determined by EDX (Energy dispersive X-ray spectroscopy). The electronic properties were investigated by in situ XAS (X-ray absorpti
Publicado em: 2009
-
29. ANÁLISE DE MÉTODOS PARA SELEÇÃO DE TRANSPORTADORES: UM ESTUDO DE CASO NA AMÉRICA CENTRAL / THE APPLICATION OF SIMPLIFIED AHP METHOD IN A MASSIVE REDUCTION OF CARRIERS: A CASE OF STUDY IN CENTRAL AMERICA
In the last decade it was possible to observe a strong pressure from public opinion to reduce the accidents with environmental consequences and road collisions. Several multinational companies, Non Governmental Organizations, as well as Governments have invested great amount of resources for this aim. Alpha, an oil company, with large operation in Central Am
Publicado em: 2009
-
30. Nanotubos de titanatos aplicados como sensores de gás
In this work, the application of titanate nanotubes (TNTs) as gas sensors is investigated. TNTs were synthesized by refluxing a TiO2 (anatase) suspension in an aqueous NaOH (10 M) solution for 24hr, followed by washing with water until neutralization. Characterization by X-ray diffraction and scanning and transmission electron microscopies revealed that the
Publicado em: 2009
-
31. Filmes automontados de óxidos metálicos: eletrocromismo e armazenamento de energia / Self-Assembled films composed of transition metal oxides for electrochromism and charge storage
Thin films of titanium dioxide (TiO2), poly(vinyl sulfonic acid) (PVS) and tungsten oxo-hydroxy (WOxHy) were prepared using the Layer-by-Layer (LbL) method, allowing for strict control of its thickness and nanoarchitecture. The properties of these films concerning lithium ion transport and storage were investigated, so that these materials can be applied in
Publicado em: 2009
-
32. Metodologia para a implantação dos processos da cadeia logística segura. / Methodology for implementing secure process in supply chain.
The development of the Methodology for the Implantation of the Processes of the Safe Logistic Chain aims at to establish parameters and methodology for application of the diverse concepts and programs of security for the foreign commerce being aimed at the load control that come being implemented for agencies of government and international organisms. These
Publicado em: 2009
-
33. Análise fotocondutiva de estruturas fotovoltaicas baseadas em TiO2 e poli(3-hexiltiofeno) / Photoconductivity analysis of photovoltaic structures based on TiO2 and poly(3-hexylthiophene)
In this work we investigated electronic transport phenomena in an ITO/TiO2/RRP3HT/Al structure using photoconductivity spectral response when devices were illuminated either by the ITO electrode or by the aluminum. RRP3HT is the regioregular poly(3-hexylthiophene), a polymer that exhibits a relatively strong photovoltaic activity. RRP3HT were dissolved in a
Publicado em: 2009
-
34. Evaluation of the viability of fungi encapsulated and stored at different temperatures / AVALIAÃÃO DA VIABILIDADE DE FUNGOS ENCAPSULADOS E ARMAZENADOS EM DIFERENTES TEMPERATURAS
Cellular immobilization represents an alternative for the bioprocess conduction, where the cells are kept in a matrix and can be used over long periods. This work was conducted with the objective to test a fungi immobilization methodology with reduced cost, to evaluate the viability of these fungi when submitted to the new encapsulation method, and to determ
Publicado em: 2009
-
35. Síntese e caracterização de NiO-CGO para anodo e eletrólitos sólidos e base de Céria para SOFC
The direct use of natural gas makes the Solid Oxide Fuel Cell (SOFC) potentially more competitive with the current energy conversions technologies. The Intermediate Temperature SOFC (IT-SOFC) offer several advantages over the High Temperature SOFC (HT-SOFC), which includes better thermal compatibility among components, fast start with lower energy consumptio
Publicado em: 2009
-
36. Study of the influence of structural defects in the properties of carbon nanotube / Estudo da influência de defeitos estruturais nas propriedades de nanotubos de carbono
We have investigated the influence of defects on structural, electronic and mechanical properties of single-walled carbon nanotubes (SWCNT), bundles of nanotubes and multi-walled carbon nanotubes (MWCNT). All our results were obtained with the first principles theory of total energy - Density Functional theory (DFT). We have investigated the structural prope
Publicado em: 2009