Implementação ferramenta LEAN – TPM - serrote mecânico alternativo

Presentemente, com a economia cada vez mais globalizada e com a grande competitividade do mercado, as empresas de produção procuram cada vez mais ajustar-se às exigências dos clientes. Por esse motivo, o controlo do fluxo produtivo torna-se imprescindível para a resolução de problemas e para a própria melhoria contínua do processo. O sistema “Lean Manufacturing”, é um conjunto de atividades que tem como meta o aumento da capacidade de resposta às mudanças e à minimização dos desperdícios na produção, constituindo-se num verdadeiro empreendimento de gestão inovadora. O TPM – Total Productive Maintenance, é uma ferramenta de melhoria continua cada vez mais utilizada nas empresas com o objetivo de melhorar a eficiência dos seus equipamentos e atingir metas para a redução de desperdícios, incluindo a restauração e manutenção de condições padrão de funcionamento. O presente trabalho visa a implementação da ferramenta TPM num equipamento (Serrote Mecânico Alternativo) instalado no Laboratório das Oficinas Mecânicas do Instituto Superior de Engenharia do Porto. No contexto prático, este trabalho consistiu numa primeira fase por implementar a ferramenta 5S´s no posto de trabalho do equipamento em estudo. Durante esta implementação foi possível detetar algumas anomalias no equipamento, tendo sido sujeitas a uma análise para encontrar as suas causas raiz. Posteriormente foi implementada a ferramenta TPM, de modo, a criar melhores condições de acesso e simplificação das atividades de inspeção, lubrificação e limpeza. Além disso, foi executado e proposto algumas oportunidades de melhoria em alguns elementos, de forma a reduzir tempos de operação e tempos de setup, contribuindo para o aumento da eficiência do equipamento.

Palácio Nacional de Sintra: o restauro de 1996

Dissertação para obtenção do grau de Mestre em Engenharia Civil na Área de especialização de Edificações

On-line self-healing of circuits implemented on reconfigurable FPGAs

To boost logic density and reduce per unit power consumption SRAM-based FPGAs manufacturers adopted nanometric technologies. However, this technology is highly vulnerable to radiation-induced faults, which affect values stored in memory cells, and to manufacturing imperfections. Fault tolerant implementations, based on Triple Modular Redundancy (TMR) infrastructures, help to keep the correct operation of the circuit. However, TMR is not sufficient to guarantee the safe operation of a circuit. Other issues like module placement, the effects of multi- bit upsets (MBU) or fault accumulation, have also to be addressed. In case of a fault occurrence the correct operation of the affected module must be restored and/or the current state of the circuit coherently re-established. A solution that enables the autonomous restoration of the functional definition of the affected module, avoiding fault accumulation, re-establishing the correct circuit state in real-time, while keeping the normal operation of the circuit, is presented in this paper.

A framework for self-healing radiation-tolerant implementations on reconfigurable FPGAs

To increase the amount of logic available in SRAM-based FPGAs manufacturers are using nanometric technologies to boost logic density and reduce prices. However, nanometric scales are highly vulnerable to radiation-induced faults that affect values stored in memory cells. Since the functional definition of FPGAs relies on memory cells, they become highly prone to this type of faults. Fault tolerant implementations, based on triple modular redundancy (TMR) infrastructures, help to keep the correct operation of the circuit. However, TMR is not sufficient to guarantee the safe operation of a circuit. Other issues like the effects of multi-bit upsets (MBU) or fault accumulation, have also to be addressed. Furthermore, in case of a fault occurrence the correct operation of the affected module must be restored and the current state of the circuit coherently re-established. A solution that enables the autonomous correct restoration of the functional definition of the affected module, avoiding fault accumulation, re-establishing the correct circuit state in realtime, while keeping the normal operation of the circuit, is presented in this paper.

Primary bioreceptivity of limestones from the mediterranean basin to phototrophic microorganisms

Dissertação apresentada para a obtenção do grau de Doutor em Conservação e Restauro pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Sobrevivência das redes de transporte da nova geração

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Electrónica e Telecomunicações

Mapping and characterization of a green biofilm inside of Vilar de Frades Church (Portugal)

Vilar de Frades church is integrated in the Vilar de Frades Monastery, located in the North part of Portugal (Barcelos). The monastery, founded in 566, suffered several architectural modifications and restoration works, the most relevant was in the XVI century. The church, in granite, has one nave and six bays,holding ten chapels with vaults of crossed ribbings. Nowadays, the chapels present a severe biological colonization characterised by an intense green biofilm, which becoming apparent in other locations inside the church. In the course of a general survey concerning the conservation state of the church, an accurate campaign was planned in order to assess the main biodeterioration agents, map biological colonization and determine the environmental conditions. Laboratory analyses were accomplished with optical microscopy and spectrofluorometry. This study presents the results of this campaign. Details on conservation or preservation works that need to be implemented are also presented.

Spectroscopy studies on conservation issues in modern and contemporary paintings

Dissertation presented to the Faculty of Sciences and Technology of New University of Lisbon in fulfilment of the requirements for the Master’s degree in Conservation and Restoration Specialization in easel painting

Assessing the balance between biodiversity conservation and coastal and estuarine management of the Sado Estuary Natural Reserve, Portugal, using BIO-SAFE

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia do Ambiente, perfil de Engenharia Ecológica

Study of a 9th century silver earrings set from Mikulčice: corrosion, conservation and maintenance

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Conservação e Restauro

The discovery of three lost ‘Salting’ carpets: science as a tool for revealing their history

Thesis presented at the Faculdade de Ciências e Tecnologia, Universidade Nova de Lisboa, to obtain a Master degree in Conservation and Restoration,Specialization in Textiles

Analysis of early synthetic dyes with HPLC-DAD-MS: an important database for analysis of colorants used in cultural heritage

Presented thesis at Faculdade de Ciências e Tecnologias, Universidade de Lisboa, to obtain the Master Degree in Conservation and Restoration of Textiles

Cochineal, a precious source of red: cochineal dyes characterization by high performance liquid chromatography with diode array detection and principal component analysis

Presented at Faculdade de Ciências e Tecnologias, Universidade de Lisboa, to obtain the Master Degree in Conservation and Restoration of Textiles

Archaeological roman glasses: comparative characterisation by non-destructive analytical techniques

Dissertation presented in fulfilment of the requirements for the Master’s degree in Conservation and Restoration

Morbidity and survival in advanced AIDS in Rio de Janeiro, Brazil

Opportunistic diseases (OD) are the most common cause of death in AIDS patients. To access the incidence of OD and survival in advanced immunodeficiency, we included 79 patients with AIDS treated at Hospital Evandro Chagas (FIOCRUZ) from September 1997 to December 1999 with at least one CD4 count <=100 cells/mm³. The incidence of OD was analyzed by Poisson's regression, and survival by Kaplan Meier and Cox analysis, considering a retrospective (before CD4 <=100 cells/mm³) and a prospective (after CD4 <=100 cells/mm³) period, and controlling for demographic, clinical and laboratory characteristics. The confidence interval estipulated was 95%. Mean follow-up period was 733 days (CI = 683-782). During the study 9 (11.4%) patients died. Survival from AIDS diagnosis was a mean of 2589 days (CI = 2363-2816) and from the date of the CD4 count CD4 <=100 cells/mm³ was a mean of 1376 (CI = 1181-1572) days. Incidence of OD was 0.51 pp/y before CD4 <= 100 cells/mm³ and 0.29 pp/y after CD4 <= 100 cells/mm³. A lower number of ODs before CD4 < 100 cells/mm³ was associated with lower incidence rates after CD4 <= 100 cells/mm³. AIDS diagnosis based on CD4+ counts <= 200 cells/mm³ was associated with lower incidence rates after CD4 <= 100 cells/mm³. Baseline CD4 counts above 50 cells/mm³ (HR = 0.13) and restoration of baseline CD4+ counts above 100 cells/mm³ (HR = 0.16) were associated with a lower risk of death. Controling both variables, only restoration of baseline counts was statistically significant (HR = 0.22, p = 0.04). We found a very low incidence of OD and long survival after CD4 < 100 cells/mm³. Survival was significantly associated with restoration of baseline CD4 counts above 100 cells/mm³.