Fractal Conductance Fluctuations of Classical Origin

In mesoscopic systems conductance fluctuations are a sensitive probe of electron dynamics and chaotic phenomena. We show that the conductance of a purely classical chaotic system with either fully chaotic or mixed phase space generically exhibits fractal conductance fluctuations unrelated to quantum interference. This might explain the unexpected dependence of the fractal dimension of the conductance curves on the (quantum) phase breaking length observed in experiments on semiconductor quantum dots.Comment: 5 pages, 4 figures, to appear in PR

Transformação e reutilização de bairros industriais

Entre o século 19 e a primeira metade do século 20, Portugal testemunhou um significativo crescimento do setor industrial com bairros industriais a emergirem dentro e nas proximidades de várias cidades. Contudo, a partir da década de 1960 até ao final do século, devido ao atraso tecnológico dos processos de produção, muitas dessas unidades industriais cessaram a sua atividade deixando os seus edifícios ao abandono, conduzindo à sua progressiva degradação. Edifícios neste tipo de condições, são geralmente indesejados para as áreas urbanas onde se encontram inseridos, levando os habitantes a afastarem-se desses locais e das suas proximidades. O objetivo deste artigo é analisar casos de transformações e reutilizações de sucesso que foram efetuadas na zona e nos edifícios do bairro de Couros, situado na cidade de Guimarães. A implementação dessas estratégias de transformação e reutilização foi muito bem-sucedida e proporcionou diversos benefícios para a cidade e para a sociedade local. Novos investimentos públicos e privados foram realizados no setor dos serviços e, atualmente, o mercado residencial está bastante ativo e com elevada procura. O presente estudo realiza uma análise dos processos de transformação e de reutilização, bem como do projeto inerente aos mesmos. Identifica ainda algumas das politicas públicas locais adotadas, boas práticas e principais barreiras encontradas, que constituem análises de casos fundamentais para a obtenção de dados, refinamento dos resultados e maximização dos esperados impactes do projeto BAMB: Buildings as Material Banks no setor dos edifícios.info:eu-repo/semantics/publishedVersio

Suppression of Anderson localization of light and Brewster anomalies in disordered superlattices containing a dispersive metamaterial

Light propagation through 1D disordered structures composed of alternating layers, with random thicknesses, of air and a dispersive metamaterial is theoretically investigated. Both normal and oblique incidences are considered. By means of numerical simulations and an analytical theory, we have established that Anderson localization of light may be suppressed: (i) in the long wavelength limit, for a finite angle of incidence which depends on the parameters of the dispersive metamaterial; (ii) for isolated frequencies and for specific angles of incidence, corresponding to Brewster anomalies in both positive- and negative-refraction regimes of the dispersive metamaterial. These results suggest that Anderson localization of light could be explored to control and tune light propagation in disordered metamaterials.Comment: 4 two-column pages, 3 figure

application of lean methodologies

Poster presentationHealthcare acquired infections (HAI) are an important cause of morbidity and mortality. Hand hygiene (HH) is one of the most effective measures for preventing HAI. However, stirring healthcare workers to comply with HH remains a challenge. Two common barriers often found are forgetfulness and the lack of time. We hypothesize that the perception of lack of time and forgetfulness stems from the pressure of too much tasks in a short period of time. Therefore, it is rational to search for efficiency and minimize waste. This study aims at exploring the use of LEAN methodologies to improve nurses’ work processes in an ICU ward. A design science research approach was used. A questionnaire was applied to the nurses followed by an observational study of an 8-hour work shift to identify nurses’ activities, processes of care, and to describe HH compliance. Next, a value stream map (VSM) was designed and the analysis performed with the nurses, which helped to identify points of possible improvement in the process of care. After this, weekly LEAN workshops were held with the objective of improving workflow efficiency. From the initial observational study, we found that a nurse may take on average 16% of their work time using the information system, and the overall rate of HH was 63%. The full compliance to HH would amount to 13% of a nurse’s workload. Three processes were identified as the most relevant HH compliance drivers: the reorganization of essential supplies, the optimal provision of medicines and monitoring equipment automatic data collection. The participant nurses defined as objectives to reduce the supplies’ delivering time and establish a stock management system. To achieve it the reorganization of the storage with the ABC method, with the nurses deciding the layout of the storage space, was essential. The use of LEAN methods permitted to detect and address improvement opportunities with significant benefits. Moreover, nurses’ participation in the process enriched the experience, helping to design a customized intervention and heightened their sense of teamwork.publishersversionpublishe