Valorization of agroindustrial waste

The main objective of this work is the valorization of residues from agro-industry giving them an added value. The valorization was performed by using a "green" and sustainable solvent - supercritical fluid, in this case carbon dioxide. Two residues and one biomass were used to produce two different final products, thereby emphasizing the versatility of the waste recovery - spent coffee grounds and microalgae Chlorella protothecoides to produce biodiesel, and tomato pomace to extract carotenoids. In the first part of this work it was demonstrated the possibility to obtain a conversion of coffee spent grounds oil into biodiesel, through an enzymatic transesterification reaction, of 98.01% with the following operating conditions: molar ratio oil:methanol 1:24, residence time 0.8 min, pressure 25 MPa, temperature 313,15K. In this first phase, it was also used the microalgae Chlorella protothecoides, a biomass, to produce biodiesel and favorable results were obtained with this green process compared with a traditional process - basic catalysis / acid. In the second part of this work, by an extraction with supercritical CO2 it was obtained 3.38% oil from tomato pomace under the following conditions: pressure 35.1 MPa, temperature 313,15K. It was found that this oil contains various carotenoids: β-carotene, lutein and lycopene. The latter is present in larger amount.

Sustainable urban planning: parameters to the operational process

In modern society, energy consumption and respect for the environment have become essential aspects of urban planning. The rising demand for alternative sources of energy, coupled with the decline in the construction sector and material usage, gives the idea that the thinking on modern cities, where attention is given to reduced energy consumption, savings, waste recycling and respect for the surrounding environment, is being put into practice. If we examine development of the city over recent centuries, by means of the theories of the most famous and influential urban planners, it is possible to identify the major problems caused by this type of planning. For this reason, in recent urban planning the use of systems of indicators that evaluate and certify land environmentally and energetically guides the master plan toward a more efficient city model. In addition the indicators are targeted on key factors determined by the commissioner or the opportunities the territory itself provides. Due the complexity of the environmental mechanics, the process of design and urban planning has become a challenging issue. The introduction of the indicators system has made it possible to register the life of the process, with a spiral route that allows the design itself to be refined. The aim of this study, built around the creation of a system of urban sustainability indicators that will evaluate highly eco-friendly cities, is to develop a certification system for cities or portions of them. The system will be upgradeable and objective, will employ real data and will be concerned with energy production and consumption.

Social tariffs for water and waste services in mainland Portugal: An impact analysis

This paper proposes to quantify the effect of social tariffs (ST) in the Portuguese water and waste sector (WWS). It calculates the amount of subsidy implicit in ST schemes, characterising the existing tariffs in 2011 and producing a synthetic tariff scene where the regulator’s recommendation is respected. This is the first time such an exercise is undertaken and it is very relevant in a context of deep economic crisis. Results suggest that there are fewer beneficiaries than what income eligibility criteria would imply and that putting the regulator’s recommendation in practice would considerably raise subsidy amounts, potentially leading to a severe increase in non-subsidised user tariffs to allow for break-even.

Questionário de satisfação do utente e do profissional : impacto num laboratório de análises clínicas

RESUMO: Temos assistido a uma evolução impressionante nos laboratórios de análises clínicas, os quais precisam de prestar um serviço de excelência a custos cada vez mais competitivos. Nos laboratórios os sistemas de gestão da qualidade têm uma importância significativa nesta evolução, fundamentalmente pela procura da melhoria continua, que ocorre não só ao nível de processos e técnicas, mas também na qualificação dos diferentes intervenientes. Um dos problemas fundamentais da gestão e um laboratório é a eliminação de desperdícios e erros criando benefícios, conceito base na filosofia LeanThinking isto é “pensamento magro”, pelo que é essencial conseguir monitorizar funções críticas sistematicamente. Esta monitorização, num laboratório cada vez mais focalizado no utente, pode ser efetuada através de sistemas e tecnologias de informação, sendo possível contabilizar número de utentes, horas de maior afluência, tempo médio de permanência na sala de espera, tempo médio para entrega de análises, resultados entregues fora da data prevista, entre outros dados de apoio à decisão. Devem igualmente ser analisadas as reclamações, bem como a satisfação dos utentes quer através do feedback que é transmitido aos funcionários, quer através de questionários de satisfação. Usou-se principalmente dois modelos: um proposto pelo Índice Europeu de Satisfação do Consumidor (ECSI) e o outro de Estrutura Comum de Avaliação (CAF). Introduziram-se igualmente dois questionários: um apresentado em formato digital num posto de colheitas, através de um quiosque eletrónico, e um outro na página da internet do laboratório, ambos como alternativa ao questionário em papel já existente, tendo-se analisado os dados, e retirado as devidas conclusões. Propôs-se e desenvolveu-se um questionário para colaboradores cuja intenção foi a de fornecer dados úteis de apoio à decisão, face à importância dos funcionários na interação com os clientes e na garantia da qualidade ao longo de todo o processo. Avaliaram-se globalmente os resultados sem que tenha sido possível apresentá-los por política interna da empresa, bem como se comentou de forma empírica alguns benefícios deste questionário. Os principais objetivos deste trabalho foram, implementar questionários de satisfação eletrónicos e analisar os resultados obtidos, comparando-os com o estudo ECSI, de forma a acentuar a importância da análise em simultâneo de dois fatores: a motivação profissional e a satisfação do cliente, com o intuito de melhorar os sistemas de apoio à decisão. ------------------------ ABSTRACT: We have witnessed an impressive development in clinical analysis laboratories, which have to provide excellent service at increasingly competitive costs, quality management systems have a significant importance in this evolution, mainly by demanding continuous improvement, which does not occur only in terms of processes and techniques, but also in the qualification of the various stakeholders. One key problem of managing a laboratory is the elimination of waste and errors, creating benefits, concept based on Lean Thinking philosophy, therefore it is essential be able to monitor critical tasks systematically. This monitoring, in an increasingly focused on the user laboratory can be accomplished through information systems and technologies, through which it is possible to account the number of clients, peak times, average length of waiting room stay, average time for delivery analysis, delivered results out of the expected date, among other data that contribute to support decisions, however it is also decisive to analyzed complaint sand satisfaction of users through employees feedback but mainly through satisfaction questionnaires that provides accurate results. We use mainly two models one proposed by the European Index of Consumer Satisfaction (ECSI), directed to the client, and the Common Assessment Framework (CAF), used both in the client as the employees surveys. Introduced two questionnaires in a digital format, one in the central laboratory collect center, through an electronic kiosk and another on the laboratory web page, both as an alternative to survey paper currently used, we analyzed the results, and withdrew the conclusions. It was proposed and developed a questionnaire for employees whose intention would be to provide useful data to decision support, given the importance of employees in customer interaction and quality assurance throughout the whole clinical process, it was evaluated in a general way because it was not possible to show the results, however commented an empirical way some benefits of this questionnaire. The main goals of this study were to implement electronic questionnaires and analyze the results, comparing them with the ECSI, in order to emphasize the importance of analyzing simultaneously professional motivation with customer satisfaction, in order to improve decision support systems.

Light harvesting in solar cells using natural pigments from red fruits adsorbed to mesoporous TiO2

Nature has developed strategies to present us with a wide variety of colours, from the green of leaves to the bright colours seen in flowers. Anthocyanins are between these natural pigments that are responsible for the great diversity of colours seen in flowers and fruits. Anthocyanins have been used to sensitize titanium dioxide (TiO2) in Dye-Sensitized Solar Cells (DSSCs). DSSCs have become one of the most popular research topic in photovoltaic cells due to their low production costs when compared to other alternatives. DSSCs are inspired in what happens in nature during photosynthesis. A primary charge separation is achieved by means of a photoexcited dye capable of performing the electron injection into the conduction band of a wide band-gap semiconductor, usually TiO2. With this work we aimed to synthesize a novel mesoporous TiO2 structure as the semiconductor in order to increase the dye loading. We used natural occurring dyes such as anthocyanins and their synthetic flavylium relatives, as an alternative to the widely used metal complexes of Ru(II) which are expensive and are environmentally unsafe. This offers not only the chance to use safer dyes for DSSCs, but also to take profit of waste biological products, such as wine and olive oil production residues that are heavily loaded with anthocyanin dyes. We also performed a photodegradation study using TiO2 as the catalyst to degrade dye contaminants, such as those from the wine production waste, by photo-irradiation of the system in the visible region of the light spectrum. We were able to succeed in the synthesis of mesoporous TiO2 both powder and thin film, with a high capacity to load a large amount of dye. We proved the concept of photodegradation using TiO2 as catalyst. And finally, we show that wine production waste is a possible dye source to DSSCs application.

Consumer satisfaction with water, wastewater and waste services in Portugal

While the concept of consumer satisfaction is a central topic in modern marketing theory and practice, citizens' satisfaction with public services, and especially water and waste services, is a eld that still remains empirically rather unexplored. The following study aims to contribute to this area by analysing the determinants of user satisfaction in the water, wastewater and waste sector in Portugal, using a unique survey of 1070 consumers undertaken by the Portuguese Water and Waste Regulator ERSAR. I perform an analysis of the relation between overall service satisfaction and attributespeci c service satisfaction with an ordered logit model. I then explore if subjective consumer satisfaction can be re ected by ERSAR's technical performance indicators. The results suggest that overall consumer satisfaction is driven by consumer's satisfaction with speci c service aspects but unrelated to socioeconomic and demographic characteristics. Furthermore, I show that there is no monotonic association between ERSAR's technical performance indicators and consumers' levels of satisfaction.

Engineering bio-based polymers using alternative solvents and processes

The work presented in this thesis explores novel routes for the processing of bio-based polymers, developing a sustainable approach based on the use of alternative solvents such as supercritical carbon dioxide (scCO2), ionic liquids (ILs) and deep eutectic solvents (DES). The feasibility to produce polymeric foams via supercritical fluid (SCF) foaming, combined with these solvents was assessed, in order to replace conventional foaming techniques that use toxic and harmful solvents. A polymer processing methodology is presented, based on SCF foaming and using scCO2 as a foaming agent. The SCF foaming of different starch based polymeric blends was performed, namely starch/poly(lactic acid) (SPLA) and starch/poly(ε-caprolactone) (SPCL). The foaming process is based on the fact that CO2 molecules can dissolve in the polymer, changing their mechanical properties and after suitable depressurization, are able to create a foamed (porous) material. In these polymer blends, CO2 presents limited solubility and in order to enhance the foaming effect, two different imidazolium based ILs (IBILs) were combined with this process, by doping the blends with IL. The use of ILs proved useful and improved the foaming effect in these starch-based polymer blends. Infrared spectroscopy (FTIR-ATR) proved the existence of interactions between the polymer blend SPLA and ILs, which in turn diminish the forces that hold the polymeric structure. This is directly related with the ability of ILs to dissolve more CO2. This is also clear from the sorption experiments results, where the obtained apparent sorption coefficients in presence of IL are higher compared to the ones of the blend SPLA without IL. The doping of SPCL with ILs was also performed. The foaming of the blend was achieved and resulted in porous materials with conductivity values close to the ones of pure ILs. This can open doors to applications as self-supported conductive materials. A different type of solvents were also used in the previously presented processing method. If different applications of the bio-based polymers are envisaged, replacing ILs must be considered, especially due to the poor sustainability of some ILs and the fact that there is not a well-established toxicity profile. In this work natural DES – NADES – were the solvents of choice. They present some advantages relatively to ILs since they are easy to produce, cheaper, biodegradable and often biocompatible, mainly due to the fact that they are composed of primary metabolites such as sugars, carboxylic acids and amino-acids. NADES were prepared and their physicochemical properties were assessed, namely the thermal behavior, conductivity, density, viscosity and polarity. With this study, it became clear that these properties can vary with the composition of NADES, as well as with their initial water content. The use of NADES in the SCF foaming of SPCL, acting as foaming agent, was also performed and proved successful. The SPCL structure obtained after SCF foaming presented enhanced characteristics (such as porosity) when compared with the ones obtained using ILs as foaming enhancers. DES constituted by therapeutic compounds (THEDES) were also prepared. The combination of choline chloride-mandelic acid, and menthol-ibuprofen, resulted in THEDES with thermal behavior very distinct from the one of their components. The foaming of SPCL with THEDES was successful, and the impregnation of THEDES in SPCL matrices via SCF foaming was successful, and a controlled release system was obtained in the case of menthol-ibuprofen THEDES.