Análise e avaliação de riscos na actividade de manutenção de juntas de dilatação em obras de arte rodoviárias

Relatório de Estágio para obtenção do grau de Mestre em Engenharia Civil na Área de Especialização de EdificaçõesO presente relatório é o resultado de um estágio realizado num ambiente real de trabalho, promovido pelo Instituto Superior de Engenharia de Lisboa (ISEL), em consonânciacom a empresa Freyssinet – Terra Armada, Pré-esforço, Estudos e Construções, S.A., no contexto do Mestrado em Engenharia Civil, perfil de Edificações. O estudo em questão compreende a identificação de riscos profissionais e respectiva Análise dos Riscos associada à actividade de manutenção de Juntas de Dilatação em obras de arte rodoviárias, com o objectivo de realizar uma Avaliação de Riscos e posteriormente, apresentar Instruções Técnicas de Segurança que contribuam para melhorar as condições de Segurança na actividade acima referida. A metodologia utilizada para a identificação dos perigos foi o Método das Energias. Os acidentes de trabalho foram classificados com base no EEAT (EUROSTAT 2001), sendo o “contacto – modalidade da lesão” o que define a natureza do risco. A Avaliação dos Riscos e o Nível de Risco foi determinado com base na matriz e nos critérios da norma OHSAS –British Standard 8800:2004. Através desta Avaliação de Riscos foi possível concluir sobre quais os principais riscos inerentes à actividade da manutenção de Juntas de Dilatação, e também entender sobre quais existe maior exposição. Com base neste estudo foram propostas medidas de segurança específicas para a totalidade dos riscos identificados, e posteriormente, foram elaborados procedimentos e instruções de segurança, com o intuito de virem a ser implementados na empresa em trabalhos futuros da mesma natureza.Abstract: The present report is the result of a post-graduate training performed in a real work environment, promoted by the Instituto Superior de Engenharia de Lisboa (ISEL), in consonance with the company Freyssinet – Terra Armada, Pre-stress, Studies and Constructions, S.A., in the context of the Master's degree in Civil Engineering, profile of Edifications This study includes the identification of occupational risks and respective Risk Analysis associated to the maintenance activity of Expansion Joints on road bridges, in order to accomplish a risk assessment and thereafter, the presentation of Technical Safety Instructionswhich contributes to improve the Safety conditions on the activity referred to above. The methodology used for the dangers identification was the Energies Method. The occupational accidents were classified based in the EEAT (EUROSTAT 2001), being the "contact - modality of the injury" what defines the nature of the risk. The Risk Assessment and Risk Level was determined based on the matrix and the criteria of the norm OHSAS –British Standard 8800:2004. Through this Risk Assessment was possible to conclude about which the principal risks inherent to the maintenance activity of Expansion Joints, and also understand about which exists greater exposure. Based on this study were proposed specific security measures for all the risks identified, and thereafter, were developed safety procedures and instructions, with the intention that they will be implemented in the company in future works of the same nature

Luminescence Property of Perovskite Structure

The photoluminescence property (PL) is a desired property for materials and the luminescence of perovskite type compounds have been known for a long time. This property was first identified to crystalline perovskite and it has only been recently identified in structurally disordered perovskite. In this work, we present a study about photoluminescence of structural disordered perovskite-structured compounds. There will be a special focus on the PL emission of titanates and zirconates: the main representants of these materials class. It will be discussed the origin of PL emission in these compounds. In addition, it will be related rare earth ion-doped structural disordered perovskite and PL emission

Different origins of green-light photoluminescence emission in structurally ordered and disordered powders of calcium molybdate

A strong greenish-light photoluminescence (PL) emission was measured at room temperature for disordered and ordered powders of CaMoO4 prepared by the polymeric precursor method. The structural evolution from disordered to ordered powders was accompanied by XRD. Raman spectroscopy, and TEM imagery. High-level quantum mechanical calculations in the density functional framework were used to interpret the formation of the structural defects of disorder powders in terms of band diagram and density of states. Complex cluster vacancies [MoO3 center dot V-O(z)] and [CaO7 center dot V-O(z)] (where V-O(z) = V-O(X), V-O(center dot), V-O(center dot center dot)) were suggested to be responsible to the appearance of new states shallow and deeply inserted in the band gap. These defects give rise to the PL in disordered powders. The natural PL emission of ordered CaMoO4 was attributed to an intrinsic slight distortion of the [MoO4] tetrahedral in the short range