Pipelined analog-to-digital conversion using current-mode reference shifting

Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores

How to increase reach efficiency and effectiveness of Meo's digital marketing campaigns

Field lab: Business project

How to increase reach efficiency and effectiveness of MEO’s digital marketing campaigns?

Field lab: Business project

Dielectric study of triton X100: a glass-forming liquid

Dissertação para obtenção do grau de mestre em Engenharia de Materiais

Al-doped ZnO ceramic sputtering targets based on nanocrystalline powders produced by emulsion detonation synthesis – deposition and application as a transparent conductive oxide material

Transparent conducting oxides (TCOs) have been largely used in the optoelectronic industry due to their singular combination of low electrical resistivity and high optical transmittance. They are usually deposited by magnetron sputtering systems being applied in several devices, specifically thin film solar cells (TFSCs). Sputtering targets are crucial components of the sputtering process, with many of the sputtered films properties dependent on the targets characteristics. The present thesis focuses on the development of high quality conductive Al-doped ZnO (AZO) ceramic sputtering targets based on nanostructured powders produced by emulsion detonation synthesis method (EDSM), and their application as a TCO. In this sense, the influence of several processing parameters was investigated from the targets raw-materials synthesis to the application of sputtered films in optoelectronic devices. The optimized manufactured AZO targets present a final density above 99 % with controlled grain size, an homogeneous microstructure with a well dispersed ZnAl2O4 spinel phase, and electrical resistivities of ~4 × 10-4 Ωcm independently on the Al-doping level among 0.5 and 2.0 wt. % Al2O3. Sintering conditions proved to have a great influence on the properties of the targets and their performance as a sputtering target. It was demonstrated that both deposition process and final properties of the films are related with the targets characteristics, which in turn depends on the initial powder properties. In parallel, the influence of several deposition parameters in the film´s properties sputtered from these targets was investigated. The sputtered AZO TCOs showed electrical properties at room temperature that are superior to simple oxides and comparable to a reference TCO – indium tin oxide (ITO), namely low electrical resistivity of 5.45 × 10-4 Ωcm, high carrier mobility (29.4 cm2V-1s-1), and high charge carrier concentration (3.97 × 1020 cm-3), and also average transmittance in the visible region > 80 %. These superior properties allowed their successful application in different optoelectronic devices.

Vulnerability of mediterranean watersheds to climate change

Desertification is a critical issue for Mediterranean drylands. Climate change is expected to aggravate its extension and severity by reinforcing the biophysical driving forces behind desertification processes: hydrology, vegetation cover and soil erosion. The main objective of this thesis is to assess the vulnerability of Mediterranean watersheds to climate change, by estimating impacts on desertification drivers and the watersheds’ resilience to them. To achieve this objective, a modeling framework capable of analyzing the processes linking climate and the main drivers is developed. The framework couples different models adapted to different spatial and temporal scales. A new model for the event scale is developed, the MEFIDIS model, with a focus on the particular processes governing Mediterranean watersheds. Model results are compared with desertification thresholds to estimate resilience. This methodology is applied to two contrasting study areas: the Guadiana and the Tejo, which currently present a semi-arid and humid climate. The main conclusions taken from this work can be summarized as follows: • hydrological processes show a high sensitivity to climate change, leading to a significant decrease in runoff and an increase in temporal variability; • vegetation processes appear to be less sensitive, with negative impacts for agricultural species and forests, and positive impacts for Mediterranean species; • changes to soil erosion processes appear to depend on the balance between changes to surface runoff and vegetation cover, itself governed by relationship between changes to temperature and rainfall; • as the magnitude of changes to climate increases, desertification thresholds are surpassed in a sequential way, starting with the watersheds’ ability to sustain current water demands and followed by the vegetation support capacity; • the most important thresholds appear to be a temperature increase of +3.5 to +4.5 ºC and a rainfall decrease of -10 to -20 %; • rainfall changes beyond this threshold could lead to severe water stress occurring even if current water uses are moderated, with droughts occurring in 1 out of 4 years; • temperature changes beyond this threshold could lead to a decrease in agricultural yield accompanied by an increase in soil erosion for croplands; • combined changes of temperature and rainfall beyond the thresholds could shift both systems towards a more arid state, leading to severe water stresses and significant changes to the support capacity for current agriculture and natural vegetation in both study areas.

Providing energy efficiency location-based strategies for buildings using linked open data

Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.

Biogenic amines in wine: gene transcription as a tool for selection of Oenococcus oeni starter strains

Dissertation presented to obtain the Ph.D degree in Biology

Hospital Efficiency: Directed internship: Deloitte & NOVA SBE

A Work Project, presented as part of the requirements for the Award of a Masters Degree in Economics from the NOVA – School of Business and Economics

Data-centric concurrency control on the java programming language

Dissertação para obtenção do Grau de Mestre em Engenharia Informática

Carbon monoxide, autophagy and cytoprotection in response to cerebral ischemia

Dissertação para obtenção do Grau de Mestre em Genética Molecular e Biomedicina

Caraterização estatística dos valores percentuais de sangue do grupo AB0 colhido pelo Centro Regional de Sangue de Lisboa e respetivo emparelhamento com a distribuição a nível hospitalar

RESUMO: A Medicina Transfusional está a mudar rapidamente em resposta a um número de diferentes catástrofes, patologias e novas técnicas da ciência. Por detrás de uma transfusão de sangue existe todo um conjunto de procedimentos, técnicas e atuações que salvaguardam o rigor e segurança científicas resultando numa maior eficiência na diminuição da morbilidade/mortalidade humana. Todo o processo de colheita, análise, processamento e distribuição de concentrados de eritrócitos comporta um capital elevado em termos da economia para a saúde e os requisitos básicos de uma gestão de qualidade, na área da saúde em geral e da hemoterapia em particular, tem de compreender, com rigor, estas condições de gestão parceria de forma a evitar um aumento nos custos da saúde. Para identificar as discrepâncias nos pedidos efetuados pelos Hospitais Públicos e Privados ao Centro de Sangue e Transplantação de Lisboa, no que diz respeito ao Sistema AB0 dos concentrados de Eritrócitos, foi feito um estudo quantitativo, com fins descritivos simples, aos 95 984 concentrados de eritrócitos enviados às 32 Instituições de Saúde da abrangência do CST de Lisboa. Tendo em conta o Sistema AB0 RhD, confirma-se que o grupo sanguíneo prevalente, tanto na população portuguesa como nos dadores de sangue que efetuaram a sua dádiva de sangue em 2011, é o grupo A Rh+. Observou-se no entanto que o grupo sanguíneo mais pedido e enviado pertence ao grupo 0 Rh positivo. Assim, apurou-se que existe uma disparidade, mesmo que pouco acentuada, nos pedidos efetuados pelos Hospitais Públicos e Privados ao Centro de Sangue e Transplantação de Lisboa no que configura ao Sistema AB0 dos concentrados de eritrócitos. Os Hospitais Públicos Sem Serviço de Colheita de Sangue e os Hospitais Privados são responsáveis por este desencontro de valores. No que se refere às inutilizações por prazo de validade ressalva-se que os desaproveitamentos de CE’s não são tão acentuados como se esperaria numa primeira fase de estudo. No entanto, e em termos económicos, se existem inutilizações por prazo de validade, existe igualmente despojo financeiro. Por detrás de cada unidade inutilizada existe um alto investimento que será desperdiçado por carência de solicitação. De forma a minimizar gastos e a salvaguardar um Banco de Sangue capaz de suportar qualquer eventualidade de rutura de stock estão patentes propostas de estratégias capazes de impedir constrangimentos diários e futuros no que diz respeito à disponibilidade de sangue e componentes sanguíneos.--------------ABSTRACT: The Transfusion Medicine it is changing fast in response to a number of different catastrophes, disease and new techniques of science. From behind a blood transfusion there is a whole set of procedures, techniques and actions that safeguard the safety and scientific rigor resulting in greater efficiency in reducing morbidity / mortality human. The entire process of procurement, testing, processing and distribution of concentrated erythrocytes involves a high capital in terms of the economy to health and the basic requirements of a quality management in healthcare in general and hemotherapy in particular has to understand with rigor, this partnership in order to avoid an increase in health costs. In order to identify discrepancies in the orders placed by the Government and Private Hospitals Center Blood and Transplant Lisbon regarding the AB0 system of concentrated erythrocytes was made a quantitative study with simple descriptive purposes to 95,984 erythrocytes concentrates sent to 32 Health Institutions of the scope of CST Lisbon. Having regard to the system AB0 blood group RhD prevalent both in the Portuguese population as blood donors, who made his blood donation in 2011, confirms that belong to group A Rh +. It was found that blood group most requested and sent belongs to group 0 Rh positive. Thus, it was found that there is a disparity, even a little sharp, requests made by the Government and Private Hospitals Blood Center and Transplantation in Lisbon that configures the system AB0 erythrocyte concentrates. The Public Hospitals without Blood Harvest and Private Hospitals are responsible for this clash of values. With regard the expiry date by disables proviso that the wastes of CE's are not as sharp as one would expect in a first phase of the study. However, in economic terms, if there is disables by expiry date, there is also financial squandering. Behind every unused unit is a high investment to be wasted by shortage of request. To minimize costs and safeguarding a Blood Bank can support any event of rupture of stock patents are proposed strategies to prevent future and diaries constraints with regard to the availability of blood and blood components.

Study on the valorization routes of ashes from thermoelectric power plants working under mono-and co-combustion regimes

Thesis submitted to obtain the Doctoral degree in Energy and Bioenergy

Separation of azeotropic mixtures using high ionicity ionic liquids

Dissertação para obtenção do Grau de Mestre em Engenharia Química e Bioquímica

Gold nanoparticles for plasmid delivery

Gene therapy presents an ideal strategy for the treatment of genetic as well as acquired diseases, such as cancer and typically involves the insertion of a functioning gene into cells to correct a cellular dysfunction or to provide a new cellular function. Gene delivery vectors are based in two models: viral and non-viral. Viral vectors have high transfection efficiency but their major barrier is immunogenicity. Since the non-viral vectors have no immunogenicity, these have been widely studied. Gold nanoparticles have been proposed as optimal delivery systems of genetic material, due their small size, high surface-to-volume ratio and the ability to be functionalized with multiple molecules. In the present work, an AuNP-based formulation was developed to deliver a plasmid in a colorectal cancer cell line, containing as reporter gene the gene encoding to EGFP. The delivery system resulted from the functionalization of 14 nm AuNP with a PEG layer (4300114 PEG chains/AuNP), which increases stability and biocompatibility of AuNPs; quaternary ammonium groups which provide positive charges that allow electrostatic binding of plasmid, which is considered the therapeutic agent to be transported into cells. The system developed was characterized by UV-vis spectroscopy, DLS, TEM and by electrophoretic mobility, yielding a formulation with 113.5 nm.Transfection efficiency of the formulation developed was evaluated through PCR and through EGFP expression by fluorescence microscopy and fluorescence spectroscopy. The internalization was observed 3h post transfection; however a low level of EGFP expression was achieved. After 24h of incubation, EGFP expression increases just 3 times compared to non-transfected cells. The commercial system (Lipofectamine) expressed EGFP 5 times more than the system developed AuNP@PEG@R4N+@pEGFP. This difference could be related to lower translocation to the nucleus.