Investigation of the regulation mechanisms for bioplastics production from industrial residues

Dissertação para obtenção do Grau de Mestre em Biotecnologia

Multipacket reception in LTE femtocell networks

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores

Aumento das taxas moderadoras nas urgências hospitalares : que impacto sobre a procura?

RESUMO - Objetivo: Quantificar a variação da procura ocorrida no Serviço de Urgência Hospitalar (SUH) de um hospital na zona de Lisboa face ao aumento de preço da taxa moderadora da urgência em janeiro de 2012. Metodologia: O presente trabalho recorre à análise de micro dados sobre a utilização do Serviço de Urgência do Hospital Garcia de Orta (HGO) em dois períodos: 1 de janeiro de 2011 a 30 de junho de 2011 e 1 de janeiro de 2012 a 30 de junho de 2012. A amostra é constituída por 156.654 idas ao SUH do HGO. Aferiu-se ainda a elasticidade da procura face ao preço por sexo, escalão etário, proveniência, local e causa da admissão e destino dos utentes. Resultados: Existiram 80.344 episódios de urgência em 2011 e 76.310 em 2012 (-5%).Em relação aos utentes não isentos, houve uma redução de 12% no total de episódios de urgência (26.168 em 2011 e 23.037 em 2012). O preço da urgência aumentou 108% para os indivíduos não isentos (€9,6 para €20). Os valores obtidos para a elasticidade da procura face ao preço são próximos de zero para o total da procura bem como para as restantes variáveis. Conclusões: Conclui-se que a procura de cuidados de urgência é inelástica face ao aumento do preço no hospital analisado. Embora se tenha verificado uma redução dos cuidados procurados (12%), esta foi muito inferior ao aumento ocorrido no preço (108%).

Catastrophic health care expenditures in Portugal between 2000-2010: Assessing impoverishment, determinants and policy implications

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

Modelling of a wastewater treatment plant using GPS-X

Dissertation to obtain the degree of Master in Chemical and Biochemical Engineering

Construction of Lean and Green indexes to measure companies’ performance

The demand for costs and time reductions in companies’ processes, in order to increase efficiency, leads companies to seek innovative management paradigms to support their needs for growth and continuous improvement. The Lean paradigm has great relevance in companies’ need for waste reduction, particularly in manufacturing companies. On the other hand the demand of companies for waste reduction has gained a new dimension not only at the material level, but also at the environmental level with the introduction of the Green paradigm. As such, manufacturing companies have been adopting practices that reduce the impact of their activities on the environment. Although nowadays many manufacturing companies already implement waste reduction practices related to Lean and Green paradigms, many of them are unable to understand specifically if their efforts are enough for the application of these practices to be successful or even if their actual performance in implementing Lean or Green practices reflects the self-assessment that they have of themselves. Thus, besides the study of the development of Lean and Green paradigms in recent years, the present dissertation has the important objective of the construction of two indexes (the Lean Index and the Green Index) enabling the measurement of the performance of Portuguese manufacturing companies relating the implementation of Lean and Green practices. The data used to create the Lean and Green indexes where obtained from the implementation of the European Manufacturing Survey 2012 in Portugal. The survey questions related to the implementation of Lean and Green practices are used as variables in the development of the model for the two indexes. For the construction of representative expressions of Lean Index and Green Index it was applied the Factorial Analysis for assigning the variables weights and aggregation.

(Non) - Demand driven servitization: strategic implications for suppliers from incorporating their customers up front

Double Degree. A Work Project, presented as part of the requirements for the Award of a Master’s Degree in Management from NOVA – School of Business and Economics and a Masters Degree in International Business, Strategy and Innovation from Maastricht University

Hotel industry: An answer to the emerging trends on the global demand side of tourism

This dissertation studies essentially how Millennials are changing the hotel industry, in the sense that new trends are emerging with this generation and hotels need to respond accordingly, in order to survive within their competitive industry. Emphasis is also given to Asian travellers, as the enlargement of these countries’ middle class populations is predicted, therefore making Asian travellers a valuable target for the hotel industry. To successfully target this segment, hoteliers need also to consider the cultural differences and aspirations that come together with the Asian travellers, and appropriately adapt their offer to them. I will then redirect this study to the city of Lisbon, the Portuguese capital, to analyse if Lisbon’s four and five-star hotel managers are aware of the new market trends, and to understand how they are changing their hotels in order to make them more attractive to Millennials and Asian travellers. Using a sample of 12 hotels (four and five-stars ratings), I have concluded that, although there is a notable undergoing process of adaptation to these guests, there is a long way ahead in order for Lisbon’s hotels to entirely please and retain millennial guests.

The economic valuation of noise reduction projects: A cost-benefit analysis approach

The main purpose of this Work Project consists in performing a practical Cost-Benefit Analysis from a social perspective of two noise reduction projects in industrial sites that aim at complying with the existing regulation. By doing so, one may expect a more comprehensive view of the benefits and costs of both projects, as well as relevant insight to the way noise exposure regulation must be optimally defined in Portugal and within the EU area.

Energy efficiency in energy policy: Empirical evidence of direct rebound effect in Portuguese household's demand for electricity

This project the direct rebound effect for the electricity demand in Portugal. While we find evidence of such an effect, the estimations also reflect the institutional arrangement that has characterized the electricity market in the country. Also, issues related to energy efficiency promotion are addressed in general putting into context the case study developed.

Do hospitals react to random demand pressure by early discharges?

This project tries to assess whether hospitals react to random demand pressure by discharging patients earlier than expected. As a matter of fact, combining an unpredictable demand for medical services with limited and, to some extent, fixed medical resources, generates strong incentives to discharge patients earlier than expected when demand is high − increasing the risk of readmission and decreasing the benefit from treatment. This work was conducted as a way to determine whether those incentives actually affect discharging decisions. Analysis of Portuguese hospitals data shows that hospital utilization levels at the time of admission, prior to the admission and post admission do have a negative impact over the length of stay in hospital, although this impact is quantitatively irrelevant. More than that, larger utilization levels have a positive impact over the probability of being discharged at certain days of the week, indicating that an early discharges problem may exist.

Estimating demand for primary health care services

Primary health services exist with the purpose of providing basic health care to every person at a cost they can afford. But is it fully available to everyone? The objective of this work project is to estimate the demand for primary health care services having into account that in some regions the citizens are not using as much health care as they would like due to supply side constraints. Using the number of consultations as proxy for demand, and applying an econometric tool called switching regression, the demand for primary health care services will be estimated.

Implementation of membrane processes for improvement of the detection of food contaminants

The EM3E Master is an Education Programme supported by the European Commission, the European Membrane Society (EMS), the European Membrane House (EMH), and a large international network of industrial companies, research centres and universities (http://www.em3e.eu)

Control in distribution networks with demand side management

The way in which electricity networks operate is going through a period of significant change. Renewable generation technologies are having a growing presence and increasing penetrations of generation that are being connected at distribution level. Unfortunately, a renewable energy source is most of the time intermittent and needs to be forecasted. Current trends in Smart grids foresee the accommodation of a variety of distributed generation sources including intermittent renewable sources. It is also expected that smart grids will include demand management resources, widespread communications and control technologies required to use demand response are needed to help the maintenance in supply-demand balance in electricity systems. Consequently, smart household appliances with controllable loads will be likely a common presence in our homes. Thus, new control techniques are requested to manage the loads and achieve all the potential energy present in intermittent energy sources. This thesis is focused on the development of a demand side management control method in a distributed network, aiming the creation of greater flexibility in demand and better ease the integration of renewable technologies. In particular, this work presents a novel multi-agent model-based predictive control method to manage distributed energy systems from the demand side, in presence of limited energy sources with fluctuating output and with energy storage in house-hold or car batteries. Specifically, here is presented a solution for thermal comfort which manages a limited shared energy resource via a demand side management perspective, using an integrated approach which also involves a power price auction and an appliance loads allocation scheme. The control is applied individually to a set of Thermal Control Areas, demand units, where the objective is to minimize the energy usage and not exceed the limited and shared energy resource, while simultaneously indoor temperatures are maintained within a comfort frame. Thermal Control Areas are overall thermodynamically connected in the distributed environment and also coupled by energy related constraints. The energy split is performed based on a fixed sequential order established from a previous completed auction wherein the bids are made by each Thermal Control Area, acting as demand side management agents, based on the daily energy price. The developed solutions are explained with algorithms and are applied to different scenarios, being the results explanatory of the benefits of the proposed approaches.

Optimization of wastewater quality in the Sines refinery

In order to address and resolve the wastewater contamination problem of the Sines refinery with the main objective of optimizing the quality of this stream and reducing the costs charged to the refinery, a dynamic mass balance was developed nd implemented for ammonia and polar oil and grease (O&G) contamination in the wastewater circuit. The inadequate routing of sour gas from the sour water stripping unit and the kerosene caustic washing unit, were identified respectively as the major source of ammonia and polar substances present in the industrial wastewater effluent. For the O&G content, a predictive model was developed for the kerosene caustic washing unit, following the Projection to Latent Structures (PLS) approach. Comparison between analytical data for ammonia and polar O&G concentrations in refinery wastewater originating from the Dissolved Air Flotation (DAF) effluent and the model predictions of the dynamic mass balance calculations are in a very good agreement and highlights the dominant impact of the identified streams for the wastewater contamination levels. The ammonia contamination problem was solved by rerouting the sour gas through an existing clogged line with ammonia salts due to a non-insulated line section, while for the O&G a dynamic mass balance was implemented as an online tool, which allows for prevision of possible contamination situations and taking the required preventive actions, and can also serve as a basis for establishing relationships between the O&G contamination in the refinery wastewater with the properties of the refined crude oils and the process operating conditions. The PLS model developed could be of great asset in both optimizing the existing and designing new refinery wastewater treatment units or reuse schemes. In order to find a possible treatment solution for the spent caustic problem, an on-site pilot plant experiments for NaOH recovery from the refinery kerosene caustic washing unit effluent using an alkaline-resistant nanofiltration (NF) polymeric membrane were performed in order to evaluate its applicability for treating these highly alkaline and contaminated streams. For a constant operating pressure and temperature and adequate operating conditions, 99.9% of oil and grease rejection and 97.7% of chemical oxygen demand (COD) rejection were observed. No noticeable membrane fouling or flux decrease were registered until a volume concentration factor of 3. These results allow for NF permeate reuse instead of fresh caustic and for significant reduction of the wastewater contamination, which can result in savings of 1.5 M€ per year at the current prices for the largest Portuguese oil refinery. The capital investments needed for implementation of the required NF membrane system are less than 10% of those associated with the traditional wet air oxidation solution of the spent caustic problem. The operating costs are very similar, but can be less than half if reusing the NF concentrate in refinery pH control applications. The payback period was estimated to be 1.1 years. Overall, the pilot plant experimental results obtained and the process economic evaluation data indicate a very competitive solution through the proposed NF treatment process, which represents a highly promising alternative to conventional and existing spent caustic treatment units.