Estratégias e internacionalização na manutenção e produção

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Molecular epidemiology of Aspergillus collected from cystic fibrosis patients

Background - Aspergillus respiratory infection is a common complication in cystic fibrosis (CF) and is associated with loss of pulmonary function and allergic disease. Methods - Fifty-three Aspergillus isolates recovered from CF patients were identified to species by Internal Transcribed Spacer Region (ITS), β-tubulin, and calmodulin sequencing. Results - Three species complexes (Terrei, Nigri, and Fumigati) were found. Identification to species level gave a single Aspergillus terreus sensu stricto, one Aspergillus niger sensu stricto and 51 Aspergillus fumigatus sensu stricto isolates. No cryptic species were found. Conclusions - To our knowledge, this is the first prospective study of Aspergillus species in CF using molecular methods. The paucity of non-A. fumigatus and of cryptic species of A. fumigatus suggests a special association of A. fumigatus sensu stricto with CF airways, indicating it likely displays unique characteristics making it suitable for chronic residence in that milieu. These findings could refine an epidemiologic and therapeutic approach geared to this pathogen.

Task-based occupational exposure assessment and particle number concentration: two important data resources to perform risk assessment for occupational exposure to particles

Environment monitoring has an important role in occupational exposure assessment. However, due to several factors is done with insufficient frequency and normally don´t give the necessary information to choose the most adequate safety measures to avoid or control exposure. Identifying all the tasks developed in each workplace and conducting a task-based exposure assessment help to refine the exposure characterization and reduce assessment errors. A task-based assessment can provide also a better evaluation of exposure variability, instead of assessing personal exposures using continuous 8-hour time weighted average measurements. Health effects related with exposure to particles have mainly been investigated with mass-measuring instruments or gravimetric analysis. However, more recently, there are some studies that support that size distribution and particle number concentration may have advantages over particle mass concentration for assessing the health effects of airborne particles. Several exposure assessments were performed in different occupational settings (bakery, grill house, cork industry and horse stable) and were applied these two resources: task-based exposure assessment and particle number concentration by size. The results showed interesting results: task-based approach applied permitted to identify the tasks with higher exposure to the smaller particles (0.3 μm) in the different occupational settings. The data obtained allow more concrete and effective risk assessment and the identification of priorities for safety investments.

Beach sand and the potential for infectious disease transmission: observations and recommendations

Recent studies suggest that sand can serve as a vehicle for exposure of humans to pathogens at beach sites, resulting in increased health risks. Sampling for microorganisms in sand should therefore be considered for inclusion in regulatory programmes aimed at protecting recreational beach users from infectious disease. Here, we review the literature on pathogen levels in beach sand, and their potential for affecting human health. In an effort to provide specific recommendations for sand sampling programmes, we outline published guidelines for beach monitoring programmes, which are currently focused exclusively on measuring microbial levels in water. We also provide background on spatial distribution and temporal characteristics of microbes in sand, as these factors influence sampling programmes. First steps toward establishing a sand sampling programme include identifying appropriate beach sites and use of initial sanitary assessments to refine site selection. A tiered approach is recommended for monitoring. This approach would include the analysis of samples from many sites for faecal indicator organisms and other conventional analytes, while testing for specific pathogens and unconventional indicators is reserved for high-risk sites. Given the diversity of microbes found in sand, studies are urgently needed to identify the most significant aetiological agent of disease and to relate microbial measurements in sand to human health risk.

Integrating early aspects with goal-oriented requirements engineering

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

Internal consistency of the self-reporting questionnaire-20 in occupational groups

ABSTRACT OBJECTIVE To assess the internal consistency of the measurements of the Self-Reporting Questionnaire (SRQ-20) in different occupational groups. METHODS A validation study was conducted with data from four surveys with groups of workers, using similar methods. A total of 9,959 workers were studied. In all surveys, the common mental disorders were assessed via SRQ-20. The internal consistency considered the items belonging to dimensions extracted by tetrachoric factor analysis for each study. Item homogeneity assessment compared estimates of Cronbach’s alpha (KD-20), the alpha applied to a tetrachoric correlation matrix and stratified Cronbach’s alpha. RESULTS The SRQ-20 dimensions showed adequate values, considering the reference parameters. The internal consistency of the instrument items, assessed by stratified Cronbach’s alpha, was high (> 0.80) in the four studies. CONCLUSIONS The SRQ-20 showed good internal consistency in the professional categories evaluated. However, there is still a need for studies using alternative methods and additional information able to refine the accuracy of latent variable measurement instruments, as in the case of common mental disorders.

Optimising the energy consumption on pultrusion process

This study is based on a previous experimental work in which embedded cylindrical heaters were applied to a pultrusion machine die, and resultant energetic performance compared with that achieved with the former heating system based on planar resistances. The previous work allowed to conclude that the use of embedded resistances enhances significantly the energetic performance of pultrusion process, leading to 57% decrease of energy consumption. However, the aforementioned study was developed with basis on an existing pultrusion die, which only allowed a single relative position for the heaters. In the present work, new relative positions for the heaters were investigated in order to optimise heat distribution process and energy consumption. Finite Elements Analysis was applied as an efficient tool to identify the best relative position of the heaters into the die, taking into account the usual parameters involved in the process and the control system already tested in the previous study. The analysis was firstly developed based on eight cylindrical heaters located in four different location plans. In a second phase, in order to refine the results, a new approach was adopted using sixteen heaters with the same total power. Final results allow to conclude that the correct positioning of the heaters can contribute to about 10% of energy consumption reduction, decreasing the production costs and leading to a better eco-efficiency of pultrusion process.

Contributos maternos para a auto-regulação do bebé na situação experimental face-to-face still-face

Dissertação apresentada na Escola Superior de Educação de Lisboa para obtenção do grau de Mestre em Intervenção Precoce

Optimizing the embedded heaters position in the pultrusion process using finite element analysis

This study is based on a previous experimental work in which embedded cylindrical heaters were applied to a pultrusion machine die, and resultant energetic performance compared with that achieved with the former heating system based on planar resistances. The previous work allowed to conclude that the use of embedded resistances enhances significantly the energetic performance of pultrusion process, leading to 57% decrease of energy consumption. However, the aforementioned study was developed with basis on an existing pultrusion die, which only allowed a single relative position for the heaters. In the present work, new relative positions for the heaters were investigated in order to optimize heat distribution process and energy consumption. Finite Elements Analysis was applied as an efficient tool to identify the best relative position of the heaters into the die, taking into account the usual parameters involved in the process and the control system already tested in the previous study. The analysis was firstly developed with basis on eight cylindrical heaters located in four different location plans. In a second phase, in order to refine the results, a new approach was adopted using sixteen heaters with the same total power. Final results allow to conclude that the correct positioning of the heaters can contribute to about 10% of energy consumption reduction, decreasing the production costs and leading to a better eco-efficiency of pultrusion process.

Estudo de Caso: Processos de orçamentação de obras

O relatório inserido na Unidade Curricular de DIPRE do Mestrado em Engenharia Civil do ISEP e desenvolvido no âmbito do estágio curricular realizado na HESPOR – Construções Lda, tem como objetivo caraterizar o mercado nacional da construção civil, os procedimentos da orçamentação, analisando os seus processos no âmbito dos concursos públicos em Portugal. Deste modo, o relatório tem por base a importância da orçamentação na construção civil e a caraterização do mercado da construção na atual situação financeira que o País se depara. Em seguida foi realizado um estudo da arte sobre os temas de custos e orçamentos, e ainda uma abordagem aos custos associados à construção civil. Depois de analisada toda a metodologia inerente à orçamentação, são caraterizados os processos das empresas do grupo para o ato de orçamentação. Foi abordado um estudo de caso para demonstrar como é elaborado o ato de orçamentação e foi realizada uma análise em função das propostas apresentadas com o intuito de afinar o processo de orçamentação de forma a tornar a proposta competitiva mas salvaguardando sempre a viabilidade, que é a estratégia adotada pela empresa.

Environmental/Regatta Buoy: Telemetry and Configuration

A monitorização ambiental é essencial para a tomada de decisões tanto na ciência como na indústria. Em particular, uma vez que a água é essencial à vida e a superfície da Terra é composta principalmente por água, a monitorização do clima e dos parâmetros relacionados com a água em ecossistemas sensíveis, tais como oceanos, lagoas, rios e lagos, é de extrema importância. Um dos métodos mais comuns para monitorar a água é implantar bóias. O presente trabalho está integrado num projeto mais amplo, com o objetivo de projectar e desenvolver uma bóia autónoma para a investigação científica com dois modos de funcionamento: (i) monitorização ambiental ; e (ii) baliza ativa de regata. Assim, a bóia tem duas aplicações principais: a coleta e armazenamento de dados e a assistência a regatas de veleiros autónomos. O projeto arrancou há dois anos com um grupo de quatro estudantes internacionais. Eles projetaram e construíram a estrutura física, compraram e montaram o sistema de ancoragem da bóia e escolherem a maioria dos componentes electrónicos para o sistema geral de controlo e medição. Este ano, durante o primeiro semestre, dois estudantes belgas - Jeroen Vervenne e Hendrick Verschelde – trabalharam nos subsistemas de recolha e armazenamento de dados (unidade de controlo escrava) e de telemetria e configuração (unidade de controlo mestre) assim como definiram o protocolo de comunicação da aplicação. O trabalho desta tese continua o desenvolvimento do subsistema de telemetria e configuração. Este subsistema _e responsável pela configuração do modo de funcionamento e dos sensores assim como pela comunicação com a estacão de base (controlo ambiental), barcos (baliza ativa de regata) e com o subsistema de recolha e armazenamento de dados. O desenvolvimento do subsistema de recolha e armazenamento de dados, que coleta e armazena num cartão SD os dados dos sensores selecionados, prossegue com outro estudante belga - Mathias van Flieberge. O objetivo desta tese é, por um lado, implementar o subsistema de telemetria e de configuração na unidade de controle mestre e, por outro lado, refinar e implementar, conjuntamente com Mathias van Flieberge, o protocolo de nível de aplicação projetado. Em particular, a unidade de controlo mestre deve processar e atribuir prioridades às mensagens recebidas da estacão base, solicitar dados à unidade de controlo escrava e difundir mensagens com informação de posição e condições de vento e água no modo de regata. Enquanto que a comunicação entre a unidade de controlo mestre e a estacão base e a unidade de controlo mestre e os barcos é sem fios, a unidade de controlo mestre e a unidade de controlo escrava comunicam através de uma ligação série. A bóia tem atualmente duas limitações: (i) a carga máxima é de 40 kg; e (ii) apenas pode ser utilizada em rios ou próximo da costa dada à limitação de distância imposta pela técnica de comunicação sem fios escolhida.

Geomecânica aplicada à estabilidade de explorações mineiras bench and fill: o caso do jazigo de Feitais, Minas de Aljustrel

Este trabalho pretende abordar a importância de um estudo geomecânico no apoio à otimização e estabilidade de explorações subterrâneas por subníveis, com criação de bancadas e posterior enchimento. O presente envolveu um estudo geológico-geotécnico em quinze galerias situadas a muro, teto e corpo da mineralização com o levantamento das características mais relevantes do maciço rochoso para aplicação das classificações geomecânicas, englobando uma amostragem de mais de 1780 descontinuidades, obtendo um modelo cartográfico subterrâneo com um panorama geral da qualidade do maciço rochoso intercetado pelas escavações nas diferentes zonas. Os dados dos levantamentos de campo levaram à criação de uma base de dados com a aplicação das classificações geomecânicas Q-System, RMR e GSI, por galeria e, em seguida, por zona, com proposta de classe de sustimento a aplicar em cada local, pelo ábaco de Barton, em conjunto com a determinação de parâmetros geomecânicos fundamentais ao refinamento do conhecimento geológico-geotécnico das unidades litológicas em estudo. Na parte final, focando a localização da massa mineralizada de Feitais é efetuada uma abordagem relativa à estabilidade das cavidades geradas pelo desmonte em bancada entre subníveis, com respetivo dimensionamento das larguras admissíveis, em condições de segurança, através da relação entre o número de estabilidade e raio hidráulico, pelo método do gráfico de estabilidade. Com esta metodologia de caracterização geológico geotécnica, é pretendido efetuar um ponto de partida à criação de um modelo geomecânico comportamental do jazigo de Feitais, Mina de Aljustrel, contando com um processo inicial de apoio ao planeamento mineiro aplicado ao método de desmonte em bancada e posterior enchimento por subníveis, atuando nos parâmetros de estabilidade e apoio à extração, favorecendo assim a segurança das operações de trabalho em conjunto com um apoio de otimização da extração.

Competitive paths for methanol decomposition on ruthenium: a DFT study

Methanol decomposition is one of the key reactions in direct methanol fuel cell (DMFC) state-of-the-art technology, research, and development. However, its mechanism still presents many uncertainties, which, if answered, would permit us to refine the manufacture of DMFCs. The mechanism of methanol decomposition on ruthenium surfaces was investigated using density functional theory and a periodic supercell approach. The possible pathways, involving either initial C−H, C−O or O−H scission, were defined from experimental evidence regarding the methanol decomposition on ruthenium and other metallic surfaces. The study yielded the O−H scission pathway as having both the most favorable energetics and kinetics. The computational data, which present a remarkable closeness with the experimental results, also indicate methanol adsorption, the starting point in all possible pathways, to be of weak nature, implying a considerable rate of methanol desorption from the ruthenium, compromising the reaction.

Spleen cell proliferation during and after skin myiasis by human bot fly Dermatobia hominis

Spleen cells from mice were examined at 5, 10, 15, 20 and 25 days post-infection (dpi) with Dermatobia hominis larva and at 5, 10, 15, 30 and 60 days post-larval emergence (dple). Cell proliferation in vitro assays were carried out with RPMI-1640 medium and larval secretory product (LSP) of D. hominis at 5, 10, 15, 20 and 25 days. When each group of mice was tested against each medium, significance was only seen for 25 dpi, with increasing order: LSP-10 d, -25 d, -5 d, -20 d, -15 d and RPMI. Significant results were also observed when each medium was tested against mice at each dpi or dple. Each dple group vs. each medium produced significant results only for 10 dple, with increasing order: LSP-5 d, -20 d, -25 d, -10 d, -15 d and RPMI. Comparative tests were also carried out between groups to refine certain observations. The LSPs were also analyzed using SDS-PAGE. The results prove that myiasis caused depletion of spleen cells, particularly under the effect of the LSP-10 and -15, but the cells tended to increase up to 60 dple. This in vitro assay may represent the real systemic immune response in the relationship LSP-D. hominis-host.

Blood Donation in the Hospital de S. José. A 11-Year Retrospective Analysis of Deferrals and Exclusions

Background: Approximately 5% of the population donates blood each year in developed countries. Recruiting and maintaining a pool of altruistic and healthy blood donors is a challenging task. Blood donation as a dynamic process must naturally co-exist with the arguably essential deferrals. Aims: To analyse a 11-year cohort of donors and blood donations in order to determine the profile of the average donor and the typical donation. Characterize the donor’s population in terms of gender, age, number of donations, most common causes for deferral and exclusion and the possible relationships between them. Establish the tendency flow of donations per year. Methods: Analysis of 95861 blood donations from 31550 donors collected between 2000 and 2010 (11 years) in the Immunohemotherapy Department of the ‘‘Centro Hospitalar Lisboa Central - Hospital de Sa˜o Jose´’’ (Lisboa, Portugal). Prior to blood donation, donors were required to fill out a form of informed consent, a questionnaire of 21 ‘‘yes or no’’ questions and were submitted to a clinical assessment and physical examination including: measurement of weight, blood pressure, pulse and capillary hemoglobin levels. Post-donation, the collected blood was tested for ALT elevation and blood-borne viral agents (HBV, HCV, HIV 1 and 2 and HTLV 1 and 2) and other infections (Treponema pallidum). Blood donors and donations were registered in a database and statistically studied in terms of: gender and age distribution, number of donations, most common causes for deferral and exclusion. The frequency of blood donations throughout the period of observation was analyzed and statistically significant relationships between the collected variables were investigated. Results: From the population of 31550 donors 61% were male and a mean age of 41.5 years (± 12.5 years) was found. From the total of 95682 blood donations collected 78% were successful while the most common causes for deferral were: donation incompatible hemoglobin levels (5% of the blood donations and 22% of deferrals), ALT elevation (3% and 14%), positive blood screening test for Treponema pallidum (1% and 6%), medication (1% and 4%), positive serological blood markers for HBV (1% and 4%), endoscopy in the previous 12 months (1% and 3%), arterial hypertension (1% and 3%), infectious conditions (1% and 3%), influenza or influenza-like symptoms (1% and 2%) and positive serological blood markers for HCV (1% and 2%). Summary/Conclusions: Several factors may have contributed to a limited number of new regular donors in the population, namely: ageing population, the alienation of the individual from the community induced by modern lifestyles and job precariousness. It is of the utmost importance to refine our blood donation campaigns according to the existing population of donors. The optimization of the blood donation potential of a population of donors must be achieved through the development of reliable and consistent screening methods. In order to appeal to new donors it is important to promote blood donations considering the profile of the regular and healthy blood donor of the existing population.