Projeto e implementação de um nodo sensor para aquisição de sinais de extensômetros em redes de sensores sem fio aplicado ao monitoramento de deformações em estruturas

Esta dissertação tem como objetivo principal propor um nodo (ou nó) sensor sem fio para ser utilizado em redes de sensores sem fio, em sistemas de aquisição de dados de extensômetros. O sistema de aquisição para os extensômetros é baseado na ponte de Wheatstone e de modo a permitir várias configurações de extensômetros. O processamento e a comunicação sem fio é realizada pelo ATmega128RFA1, composto por um microcontrolador e um transceiver Rádio-Frequência com o padrão Zigbee. O nodo foi projetado para garantir confiabilidade na aquisição de dados e ser totalmente controlado remotamente. Entre os parâmetros controláveis estão: o ganho do sinal e a taxa de amostragem. Além disso, o nodo possui recursos para efetuar o equilíbrio da ponte de Wheatstone automaticamente. A escolha de seus componentes, baseou-se em critérios relacionados ao consumo de energia do mesmo e ao custo. Foi concebida uma placa de circuito impresso (PCI) para o nodo, e sobre ela foram realizadas estimativas sobre o consumo de energia e valor agregado do protótipo, com o objetivo de analisar a sua viabilidade. Além do projeto do nodo sensor, o trabalho apresenta a proposta de integração do mesmo em uma rede de sensores sem fio (RSSF), incluindo a sugestão do hardware complementar e desenvolvimentos dos softwares. Para os testes do nodo sensor, foi construido experimentalmente um transdutor de força.

Analysis of modified bowtie nanoantennas in the excitation and emission regimes

In this work, we analyze modified bowtie nanoantennas with polynomial sides in the excitation and emission regimes. In the excitation regime, the antennas are illuminated by an incident plane wave, and in the emission regime, the excitation is fulfilled by infinitesimal electric dipole positioned in the gap of the nanoantennas. Several antennas with different sizes and polynomial order were numerically analyzed by method of moments. The results show that these novel antennas possess a controllable resonance by the polynomial order and good characteristics of near field enhancement and confinement for applications in enhancement of spontaneous emission of a single molecule.

Síntese de cerâmicas nanoestruturadas híbridas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Formação e crescimento de nanopartículas de óxido de zinco via sol-gel

Pós-graduação em Química - IQ

Nanopartículas magnéticas de 'FE''CO'@'AU': preparação, caracterização e funcionalização com complexo de 'RU'(II) luminescente

Pós-graduação em Química - IQ

Estudo de mecanismos de transporte em nanofios de óxido de índio dopado com estanho

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Effect of a Polymeric Protective Coating on Optical and Electrical Properties of Poly(p-phenylene vinylene) Derivatives

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

First principles investigations on the electronic structure of anchor groups on ZnO nanowires and surfaces

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

PT-symmetry management in oligomer systems

We study the effects of management of the PT-symmetric part of the potential within the setting of Schrodinger dimer and trimer oligomer systems. This is done by rapidly modulating in time the gain/loss profile. This gives rise to a number of interesting properties of the system, which are explored at the level of an averaged equation approach. Remarkably, this rapid modulation provides for a controllable expansion of the region of exact PT-symmetry, depending on the strength and frequency of the imposed modulation. The resulting averaged models are analysed theoretically and their exact stationary solutions are translated into time-periodic solutions through the averaging reduction. These are, in turn, compared with the exact periodic solutions of the full non-autonomous PT-symmetry managed problem and very good agreement is found between the two.

A Silsesquioxane Organically Modified with 4-Amino-5-(4-pyridyl)-4H-1,2,4-triazole-3-thiol: Thermal Behavior and Its Electrochemical Detection of Sulfhydryl Compounds

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of a Silver Nanoparticles Solution on Staphylococcus aureus and Candida spp.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Silver Molybdate and Silver Tungstate Nanocomposites with Enhanced Photoluminescence

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Proposta de uma automação residencial para um anteprojeto de uma instalação eletrica

The human social organization has undergone major changes in recent years. The technological and digital revolutions accelerated the process of dissemination and evolution of the knowledge in all sciences, from social studies to nanotechnology. This process led to many advances that have enabled the emergence of new markets. Among these new markets, residential automation shows to be a market of great potential, seeking to meet the needs of residents, in order to make their daily practice and as fast as the rhythm of present life requests. To perform this task the residence stops being a passive place and becomes an active and controllable system, where actions may occur without the need for direct human interaction. The aim of this work is designing the electrical installation of a residence seeking better use of energy and show the technology diversity involving intelligent houses

Nanoregulação: Avaliação dos cenários internacional e brasileiro

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Tailoring the refractive index of Ge-S based glass for 3D embedded waveguides operating in the mid-IR region

The photosensitivity of GeSx binary glasses in response to irradiation to femtosecond pulses at 800 nm is investigated. Samples with three different molecular compositions were irradiated under different exposure conditions. The material response to laser exposure was characterized by both refractometry and micro-Raman spectroscopy. It is shown that the relative content of sulfur in the glass matrix influences the photo-induced refractive index modification. At low sulfur content, both positive and negative index changes can be obtained while at high sulfur content, only a positive index change can be reached. These changes were correlated with variations in the Raman response of exposed glass which were interpreted in terms of structural modifications of the glass network. Under optimized exposure conditions, waveguides with positive index changes of up to 7.8x10−3 and a controllable diameter from 14 to 25 μm can be obtained. Direct inscription of low insertion losses (IL = 3.1 – 3.9 dB) waveguides is demonstrated in a sample characterized by a S/Ge ratio of 4. The current results open a pathway towards the use of Ge-S binary glasses for the fabrication of integrated mid-infrared photonic components.