17 resultados para wave pocket method
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Proceedings of the International Conference on Computational Intelligence in Medicine Healthcare, CIMED 2005, Costa da Caparica, June 29 - July 1, 2005
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Void formation during the injection phase of the liquid composite molding process can be explained as a consequence of the non-uniformity of the flow front progression. This is due to the dual porosity within the fiber perform (spacing between the fiber tows is much larger than between the fibers within in a tow) and therefore the best explanation can be provided by a mesolevel analysis, where the characteristic dimension is given by the fiber tow diameter of the order of millimeters. In mesolevel analysis, liquid impregnation along two different scales; inside fiber tows and within the open spaces between the fiber tows must be considered and the coupling between the flow regimes must be addressed. In such cases, it is extremely important to account correctly for the surface tension effects, which can be modeled as capillary pressure applied at the flow front. Numerical implementation of such boundary conditions leads to illposing of the problem, in terms of the weak classical as well as stabilized formulation. As a consequence, there is an error in mass conservation accumulated especially along the free flow front. A numerical procedure was formulated and is implemented in an existing Free Boundary Program to reduce this error significantly.
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Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Mecânica
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Sustainable Construction, Materials and Practice, p. 426-432
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RESUMO: A presente dissertação para tese de doutoramento apresenta o desenvolvimento e a validação de um método simples e original para o diagnóstico de calcificações vasculares em doentes em diálise, utilizando um score semiquantitativo criado por nós e obtido em RX simples da bacia e das mãos, denominado score de calcifi cação vascular simples. Demonstramos que este score vascular simples é preditor de risco cardiovascular nos doentes em diálise. O score de calcificação vascular simples associou-se ainda à baixa densidade mineral óssea avaliada por dual energy X -ray absortiometry (DXA) no colo do fémur. Verifi camos igualmente que, em doentes em diálise, as calcifi cações coronárias quantifi cadas pelo score de Agatston e o score de calcifi cação vascular simples se associaram a um menor volume ósseo avaliado em biopsias ósseas. Estes trabalhos corroboram a hipótese da existência de um elo de ligação entre a doença óssea e a doença vascular nos doentes em diálise, e um dos elementos que contribuem para este elo de ligação podem ser as calcificações vasculares. Este score de calcificação vascular simples avalia calcifi cações em artérias de grande, médio e pequeno calibre, e inclui os dois padrões radiológicos de calcificação: calcificação linear, associada à calcifi cação da camada média da parede arterial, e calcificação irregular, associada à calcifi cação da camada íntima arterial1. Nos diferentes trabalhos por nós publicados demonstramos que as calcificações vasculares avaliadas por este método simples e barato permitem a identificação de indivíduos com elevado risco cardiovascular. Este score vascular associa -se a maior risco de mortalidade cardiovascular2, de mortalidade de causa global3, de internamentos cardiovasculares2, de doença ardiovascular2, de doença arterial periférica2,4,de calcifi cações valvulares5 e de rigidez arterial3. As guidelines KDIGO (Kidney disease: improving global outcomes), publicadas em 2009,sugerem que os doentes renais crónicos nos estadios 3 a 5, com calcificações vasculares e valvulares, devem ser considerados como apresentando o mais elevado risco cardiovascular6. A elevada mortalidade dos doentes renais crónicos não é totalmente explicada pelos fatores de risco tradicionais7. A organização KDIGO defende, desde 2006, a hipótese da existência de um elo de ligação entre a doença óssea e a doença vascular8. Esta ligação pode ser explicada pelas alterações do metabolismo mineral e ósseo e pela sua interação com as calcificações vasculares. Verificamos, nos nossos trabalhos, uma associação entre calcifi cações vasculares e doença óssea. O baixo volume ósseo diagnosticado por análise histomorfométrica de biopsias ósseas foi preditor de maior risco de calcificações vasculares avaliadas pelo score de calcifi cação vascular simples (dados apresentados nesta dissertação, no capítulo 6) e pelo score coronário de Agatston num grupo de doentes em diálise9. A contribuição original deste artigo9 foi considerada merecedora de um editorial feito pelo Dr. Gérard London10, investigador líder na área da calcificação vascular dos doentes renais crónicos e actual Presidente da EDTA (European Dialysis and Transplantation Association). Fomos também os primeiros a descrever uma associação independente e inversa entre a densidade mineral avaliada no colo do fémur por DXA (dual energy X -ray absortiometry) com calcificações vasculares avaliadas pelo score de calcificação vascular simples, com rigidez arterial avaliada por velocidade de onda de pulsocarotidofemoral e com doença arterial periférica diagnosticada por critérios clínicos11. Fomos igualmente os primeiros a mostrar uma correlação signifi cativa entre a densidade mineral óssea avaliada por DXA no colo do fémur, mas não na coluna lombar, com a espessura cortical avaliada por análise histomorfométrica em biopsia óssea12. O nosso estudo atribui pela primeira vez à DXA um papel no diagnóstico de porosidade cortical nos doentes em diálise. A utilidade da avaliação diferencial da densidade mineral óssea cortical e trabecular necessita ainda de ser confirmada em estudos prospectivos. Este achado inovador do nosso estudo foi mencionado pela ERBP (European Renal Best Practice) no comentário feito à posição da KDIGO que considera ser reduzida a utilidade da densidade mineral óssea nos doentes em diálise13. Dois dos trabalhos incluídos nesta dissertação foram referenciados nas guidelines KDIGO 2009 para avaliar a prevalência das calcificações vasculares (KDIGO 2009: Tabela suplementar 10, Fig. 3.6) e para validar a associação entre calcificações vasculares e mortalidade cardiovascular (KDIGO 2009: Tabela suplementar 12, Fig. 3.7)6. A inclusão destes nossos dois estudos nas referências destas guidelines, que utilizaram o exigente sistema GRADE (Grades of recommendation, assessment, development, and evaluation) na classificação e selecção dos estudos, valida o interesse científico dos nossos trabalhos. O diagnóstico de calcificações vasculares tem um interesse prático para os doentes renais crónicos. A presença de calcifi cações vasculares é um sinal de alerta para a existência de um elevado risco cardiovascular, e esta informação pode ser utilizada para modificar a terapêutica nestes doentes6. Diferentes métodos podem ser usados para diagnosticar calcificações vasculares nos doentes em diálise14,15. O score de calcificação vascular simples tem a vantagem da simplicidade e de poder ser facilmente interpretado pelo nefrologista, sem necessidade de um radiologista. A reprodutibilidade deste score já foi demonstrada por diferentes grupos em estudos nacionais e internacionais16-24. Nestes estudos foi demonstrado que as calcifi cações vasculares avaliadas pelo método criado por nós são preditoras de maior risco de eventos cardiovasculares16, de amputações dos membros inferiores17, de velocidade de onda de pulso18,19, de calcificações corneanas e conjuntivais20 e de calcifi cações coronárias21. Também foi demonstrada uma associação inversa entre o score de calcificação vascular simples com os níveis séricos de PTH21, com os níveis de 25(OH)vitamina D 22,23 e com os níveis de fetuína A19,24. Todos estes estudos, realizados por diferentes grupos, que utilizaram o score de calcificação vascular simples na sua metodologia, comprovam a facilidade de utilização deste score e a concordância de resultados atestam a sua reprodutibilidade e a utilidade na avaliação dos doentes renais crónicos. ---------------------------ABSTRACT: This thesis presents the development and validation of a simple and original method to identify vascular calcifications in dialysis patients, using a semi -quantitative score that we have created and that is obtained in plain X -ray of pelvis and hands. This score was named in different publications as “simple vascular calcifi cation score”. We have demonstrated that this score is a predictor of higher cardiovascular risk in dialysis patients. The simple vascular calcification score was also associated with lower mineral bone density evaluated by DXA in femoral neck. In hemodialysis patients coronary calcifications evaluated by the coronary Agatston score and by the simple vascular calcification score were associated with lower bone volume analysed in bone biopsies. These studies corroborate the hypothesis of the existence of a link between bone disease and vascular disease in dialysis patients and one of the elements of this link may be vascular calcifications. This simple vascular calcification score identifi es calcifications in large, medium and small calibre arteries and includes the two radiological patterns of arterial calcifi cation: linear calcification which has been associated with the calcifi cation of the media layer of the arterial wall and irregular and patchy calcification which has been associated with the calcifi cation of the intima layer of the arterial wall1. In the several studies that we have published we have demonstrated that vascular calcifications evaluated by this simple and inexpensive method allow the identification of patients with high cardiovascular risk. This simple vascular calcification score is an independent predictor of cardiovascular mortality2, all -cause mortality3, cardiovascular hospitalizations2, cardiovascular disease2, peripheral artery disease2,4, valvular calcifi cations5 and arterial stiffness3.KDIGO (Kidney Disease: Improving Global Outcomes) guidelines published in 2009 suggest that chronic kidney disease patients in stages 3 to 5, with vascular and valvular calcifications should be considered to be at the highest cardiovascular risk6. The high mortality of chronic kidney disease patients is not completely explained by the traditional risk factors7 and KDIGO group supports, since 2006, the hypothesis of the existence of a link between bone disease and vascular disease8.This link may be explained by the alterations of the bone and mineral metabolism and their interaction with development and progression of vascular calcifications. We have also verifi ed in our studies the existence of an association between vascular calcifications and bone disease. Low bone volume diagnosed by histomorphometric analysis of bone biopsies, in a group of dialysis patients, was independently associated with the simple vascular calcification score (data presented in this thesis,chapter 6) and with coronary calcifications evaluated by the Agatston score9. The original contribution of this article published in CJASN9 deserved a commentary in an Editorial written by Prof. Gérard London10 leader investigator in this area and current EDTA (European Dialysis and Transplantation Association) President. We were also the fi rst group to describe an independent and inverse association between bone mineral density evaluated in the femoral neck by DXA (dual energy X -ray absortiometry) with vascular calcifications evaluated by the simple vascular calcification score, with arterial stiffness evaluated by carotid-femoral pulse wave velocity and with peripheral artery disease diagnosed by clinical criteria11. We were also the first group to demonstrate a significant correlation between bone mineral density evaluated by DXA in femoral neck but not in lumbar spine, with cortical thickness evaluated by histomorphometric analysis of bone biopsy12. Our study has attributed to DXA, for the first time, a role in the diagnosis of cortical porosity in dialysis patients. The clinical utility of the differential evaluation of bone mineral density in cortical or trabecular bone needs, however, to be confi rmed in prospective studies. This original fi nding of our study was mentioned by ERBP (European Renal Best Practice) commenting the KDIGO position in relation with the reduced utility of bone mineral density evaluation in dialysis patients13. Two of the studies included in this thesis have been integrated in a group of studies selected as references by the KDIGO guidelines published in 2009 to evaluate the prevalence of vascular calcifications in CKD patients (KDIGO 2009: Supplementary Table 10, Fig. 3.6) and to corroborate the association between vascular calcifications and cardiovascular mortality (KDIGO 2009: Supplementary Table 12, Fig. 3.7)6. The inclusion of both studies as references in the KDIGO guidelines that have used the exigent GRADE system (Grades of Recommendation, Assessment, Development, and Evaluation) in the classifi cation and selection of studies, validates the scientifi c value of our studies. The diagnosis of vascular calcifi cations has a practical interest for chronic kidney disease patients. The presence of vascular calcifications is an alert sign to the existence of a high cardiovascular risk and this information may be used to modify the treatment of these patients6. Different methods may be used to detect the presence of vascular calcifications in dialysis patients14,15. The simple vascular calcifi cation score has the advantage of being simple, inexpensive and easily evaluated by the Nephrologist without the need for a Radiologist interpretation. The reproducibility of this method has already been demonstrated by other groups in national and international studies16 -24. It was demonstrated in those studies that vascular calcifi cations evaluated by the method created by us, predict higher risk of cardiovascular events16, higher risk of lower limbs amputations17, higher pulse wave velocity18,19, corneal and conjuntival calcifi cations 20 and coronary calcifi cations21. A negative association between the simple vascular calcification score and PTH levels21, 25(OH) vitamin D levels22,23 and Fetuin A levels19,24 has also been demonstrated. All these studies performed by different groups that have used the simple vascular calcifi cation score in their methods demonstrate that this score is simple, useful and reproducible in the evaluation of chronic kidney disease patients simple, useful and reproducible in the evaluation of chronic kidney disease patients.
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ABSTRACT: Financing is a critical factor in ensuring the optimal development and delivery of a mental health system. The primary method of financing worldwide is tax-based. However many low income countries depend on out-of-pocket payments. There is a report on Irish Health Care funding but none that deals exclusively with mental health care. This paper analyses the various financial models that exist globally with respect to financing the mental health sector, examines the impact of various models on service users, especially in terms of relative ‘financial burden’ and provides a more detailed examination of the current mental health funding situation in Ireland After extensive internet and hardcopy research on the above topics, the findings were analysed and a number of recommendations were reached. Mental health service should be free at the point of delivery to achieve universal coverage. Government tax-based funding or mandatory social insurance with government top-ups, as required, appears the optimal option, although there is no one funding system applicable everywhere. Out-of-pocket funding can create a crippling financial burden for service users. It is important to employ improved revenue collection systems, eliminate waste, provide equitable resource distribution, ring fence mental health funding and cap the number of visits, where necessary. Political, economic, social and cultural factors play a role in funding decisions and this can be clearly seen in the context of the current economic recession in Ireland. Only 33% of the Irish population has access to free public health care and the number health insurance policy holders has dramatically declined, resulting in increased out-of-pocket payments. This approach risks negatively impacting on the social determinants of health, increasing health inequalities and negatively affecting economic productivity. It is therefore important the Irish government examines other options to provide funding for mental health services.
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Project work presented as a partial requirement to obtain a Master Degree in Information Management
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Dissertation to obtain the Master Degree in Biotechnology
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Finance from the NOVA – School of Business and Economics
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A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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Dissertation presented to obtain the Ph.D degree in Chemistry.
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This thesis evaluates a start-up company (Jogos Almirante Lda) whose single asset is a board game named Almirante. It aims to conclude whether it makes sense to create a company or just earn copyrights. The thesis analyzes the board game’s market, as part of the general toy’s market, from which some data exists: European countries as well as the USA. In this work it is analyzed the several ways to finance a start-up company and then present an overview of the valuation of the Jogos Almirante based on three different methods: Discounted Cash Flow, Venture Capital Method and Real Options.
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The recent massive inflow of refugees to the European Union (EU) raises a number of unanswered questions on the economic impact of this phenomenon. To examine these questions, we constructed an overlapping-generations model that describes the evolution of the skill premium and of the welfare benefit level in relevant European countries, in the aftermath of an inflow of asylum-seekers. In our simulation, relative wages of skilled workers increase between 8% and 11% in the period of the inflow; their subsequent time path is dependent on the initial skill premium. The entry of migrants creates a fiscal surplus of about 8%, which can finance higher welfare benefits in the subsequent periods. These effects are weaker in a scenario where refugees do not fully integrate into the labor market.