Transparent conducting oxides for active hybrid metamaterial devices

We present here a study of the combined nonlinear response of plasmonic antenna—transparent conducting oxide hybrids for activation of metamaterial devices. Nanoantenna layers consisting of randomly positioned gold nanodisk dimers are fabricated using hole-mask lithography. The nanoantenna layers are covered with a 20 nm thin layer of transparent conducting oxide (TCO). We investigate the response of atomic layer deposited aluminum-doped zinc oxide (AZO) next to indium–tin oxide (ITO) produced using sputter coating. We show that our results are in agreement with the hypothesis of fast electron-mediated cooling, facilitated by the Ohmic interface between the gold nanodisks and the TCO substrate, which appears a universal mechanism for providing a new hybrid functionality to active metamaterial device

Bounded and unbounded polynomials and multilinear forms: Characterizing continuity

In this paper we prove a characterization of continuity for polynomials on a normed space. Namely, we prove that a polynomial is continuous if and only if it maps compact sets into compact sets. We also provide a partial answer to the question as to whether a polynomial is continuous if and only if it transforms connected sets into connected sets. These results motivate the natural question as to how many non-continuous polynomials there are on an infinite dimensional normed space. A problem on the \emph{lineability} of the sets of non-continuous polynomials and multilinear mappings on infinite dimensional normed spaces is answered.Comment: 8 page

Developing an automated system for shoe sole halogenation

This paper describes a project developed in the Department of Industrial Electronics for a shoe wear manufacturer. It envisaged the study and automation of a human operated position of a shoe production line. A trade of investment and operational costs, technical feasibility and environmental benefits pointed to the selection of the shoe’s sole halogenation position. This operation, manually performed, is done before glue application. Its purpose is the preparation of the shoe sole to receive, in good conditions, the glue. The chemical material used is toxic and harmful to operators. The developed system integrates a manipulator and an artificial vision system. The results that emerged from the experimental tests demonstrated that the proposed automated system works as desired. The system exhibits the additional advantage of performing the halogenation procedure in almost half of the time required by a human operator. The image processing algorithms included in the system software are fast enough to enable image acquisition and processing as well as the transmission of the path to the robot controller, on line

Compensador de tensão do tipo activo série controlado por computador pessoal

Os filtros activos do tipo série são equipamentos de electrónica de potência capazes de compensar alguns dos problemas de qualidade de energia dos sistemas eléctricos, nomeadamente: interrupções, sobretensões e subtensões momentâneas, distorção da tensão causada por harmónicos, desequilíbrio de tensões em sistemas trifásicos, flutuação de tensão (flicker), sobretensões e subtensões momentâneas, e podem também realizar a correcção dinámica do factor de potência. O objectivo principal deste trabalho consistiu no estudo, simulação, desenvolvimento, e teste de um filtro activo série com sistema de controlo implementado num computador pessoal (PC) munido de uma placa de aquisição de dados genérica para o barramento PCI. Esta opção justifica-se devido ao seu baixo custo, elevada capacidade de processamento e versatilidade. Neste artigo apresenta-se o esquema eléctrico do compensador activo série desenvolvido, o seu algoritmo de controlo e resultados experimentais obtidos