Study of the valorisation of the solid by-products obtained in the co-pyrolysis of different wastes

Dissertação para obtenção do grau de doutor em Energia e Bioenergia

Compact ion-source based on superionic rubidium silver iodide (RbAg4I5) solid electrolyte

Dissertação para obtenção do Grau de Mestre em Engenharia Física

Parameter estimation in the presence of auxiliary information

Dissertação para obtenção do Grau de Doutora em Estatística e Gestão de Risco, Especialidade em Estatística

Implementing the SC-FDMA transmission technique using the GNURadio platform

Dissertação apresentada para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

A built-in self-test technique for high speed analog-to-digital converters

Fundação para a Ciência e a Tecnologia (FCT) - PhD grant (SFRH/BD/62568/2009)

Intervenção educativa junto de um grupo de enfermeiros de um serviço de medicina : impacto na prática da terapêutica inalatória

RESUMO: O presente estudo, enquadra-se, no domínio do exercício profissional dos enfermeiros e na formação em serviço destes profissionais e teve por objectivo avaliar, num grupo de enfermeiros de um serviço de medicina, o impacto de uma intervenção educativa na melhoria dos procedimentos a executar na prática da terapêutica inalatória. A amostra do estudo (amostra por conveniência) foi constituída por oito enfermeiros do serviço de medicina do Hospital Curry Cabral (idades compreendidas entre os 24 a 43 anos de idade), sem anterior formação específica na área da terapêutica inalatória, mas com experiencia profissional prévia com doentes respiratórios. O estudo decorreu em dois momentos de avaliação: avaliação 0 (antes da intervenção educativa) e avaliação 1 (após a intervenção educativa). Entre estes dois momentos, foi ministrada, a todos os enfermeiros, uma acção de formação sobre terapêutica inalatória, com componente teórico-prática. Antes e depois da intervenção educativa foram aplicados dois instrumentos: para avaliação dos conhecimentos teóricos, construi-se e aplicou-se, um questionário de auto-avaliação de conhecimentos sobre terapêutica inalatória ao grupo dos enfermeiros, e para avaliação dos conhecimentos práticos e execução de procedimentos, uma grelha de observação da demonstração da técnica de inalação com três dispositivos inalatórios: MDI, MDI com câmara expansora ACE e DPI turbohaler®. Os resultados do estudo mostraram que o grupo dos enfermeiros da nossa amostra detinha já alguns conhecimentos de carácter teórico, de âmbito geral, sobre a terapêutica inalatória, mas conhecimentos pouco sólidos, nomeadamente no que concerne aos fármacos utilizados por via inalatória. Verificou-se, ainda, um deficiente domínio de conteúdos de carácter mais específico e prático sobre terapêutica inalatória, por exemplo a importância de determinados procedimentos - agitação do inalador, tempo de pausa entre cada inalação, cuidados de manutenção da câmara expansora, higienização da cavidade bucal após a inalação dos corticosteróides. Quanto à observação da técnica de inalação, o grupo dos enfermeiros revelou algumas lacunas, quer relativamente à técnica de inalação com MDI, quer do MDI com câmara expansora, observando-se a execução de passos incorrectos e mesmo omissão de passos por parte dos enfermeiros, antes da intervenção educativa.Não nos foi possível realizar a observação da técnica de inalação com dispositivo de pó seco turbohaler®, dado que nenhum dos enfermeiros da nossa amostra se sentiu capaz de manusear de forma correcta este dispositivo, antes e após a formação. Em termos globais, achamos que a formação dada sobre terapêutica inalatória, mostrou melhorar os conhecimentos teóricos e práticos dos enfermeiros neste âmbito. Esta melhoria ficou claramente demonstrada no aumento do número de respostas correctas dadas pelos enfermeiros no questionário efectuado, após a formação. Do mesmo modo, após a formação, registou-se uma melhoria considerável dos conhecimentos específicos e práticos, no que concerne à importância de determinados procedimentos na prática da terapêutica inalatória - agitação do inalador, tempo de pausa entre cada inalação, cuidados de manutenção da câmara expansora, higienização da cavidade bucal após a inalação dos corticosteróides - observando-se, um maior número de respostas correctas assinaladas no questionário. Em contrapartida, os conhecimentos sobre fármacos administrados por via inalatória, ficaram um pouco aquém das expectativas, pois o número de respostas correctas dadas pelos enfermeiros após a formação não foi significativo. Poderemos mesmo dizer que, a acção de formação com maior grau de especificidade sobre fármacos não se revelou eficaz e gerou até alguma ―confusão‖ neste grupo de enfermeiros, parecendo que os conhecimentos anteriores sobre fármacos por via inalatória não estariam consolidados antes da formação. De igual modo, após a formação, registou-se no grupo dos enfermeiros do estudo uma melhoria na performance da técnica de inalação com o MDI e MDI com a câmara expansora. Os enfermeiros do estudo, não só corrigiram os passos ou itens de avaliação da técnica inalatória, anteriormente executados incorrectamente, mas também, mostraram um melhor conhecimento dos passos ou itens de avaliação da técnica de inalação, com menor número de passos ou itens de avaliação omissos, após a formação. Em contrapartida, a acção de formação, no que diz respeito ao dispositivo de pó seco turbohaler®, não cumpriu o seu objectivo, dado que nenhum dos enfermeiros da amostra foi capaz de demonstrar a técnica de inalação com este dispositivo, antes e após a formação. Poderemos dizer que, não sendo um dispositivo da sua prática clínica, os enfermeiros não sentiram necessidade de adquirir estes conhecimentos. Em síntese, podemos concluir que na sua globalidade, a formação dada (com informação actualizada sobre as orientações mais adequadas neste domínio) e o treino formal dos enfermeiros neste âmbito, foi bastante proveitoso, uma vez que, mostrou melhorar os conhecimentos teóricos e práticos na prática da terapêutica inalatória do grupo de enfermeiros doserviço de medicina. Realça-se, no entanto, a importância de uma formação adequada, sentida como útil pelos enfermeiros, faseada, ligada à prática dos profissionais e alternando com momentos de exercício profissional. Os conhecimentos e os procedimentos dos enfermeiros deverão ainda ser monitorizados e avaliados ao longo do tempo, para a detecção de eventuais desvios que a rotina pode introduzir e para levantamento de novas necessidades de formação.-------------------ABSTRACT: This study fits in the domain of in-service training of professional nurses. It was aimed to assess the impact of an educational intervention and the consequent improvement of the practice of inhalation therapy in a group of nurses from a medical service The study sample (convenience sample) was consituted by eight nurses from the medical service, Hospital Curry Cabral (aged 24-43 years) without previous special training in the field of inhalation therapy, but with prior experience with patients with respiratory diseases. The study ran in two moments of evaluation: evaluation 0 (before the educational intervention) and evaluation 1 (post-intervention). Between these two moments, a training program about therapeutic inhalation was administered to all nurses, with a double component of theory and practice. Before and after the educational intervention two evaluation tools were applied: for the assessment of theoretical knowledge, the nurses had to fill a self-assessment questionnaire and in order to evaluate their knowledge related to procedural skills as well as their performance, they were observed (and their behaviour recorded on a check-list) during a demonstration of three inhalation techniques with devices: metered dose inhaler, metered dose inhaler with a spacer device ACE® and device turbohaler® The study results showed that the group of nurses in our sample had already some knowledge of theoretical nature (general scope of the inhalation therapy) but little solid knowledge, particularly in regard to drugs used in inhalation. In fact, a relatively weaker knowledge was registerd in what concerns specific and practical knowledge about inhalation therapy, for example, the importance of certain procedures - shaking the inhaler, pause between each inhalation, maintenance care of spacer device, mouth cavity hygiene after inhalation of corticosteroids. As for the observation of the inhaler technique, it was found that the group of nurses had a poor inhalation technique, in what concerns inhalation technique with MDI or MDI with spacer device, with a performance with several incorrect steps, or even omission of steps by nurses before the educational intervention. Finally, as the observation technique of the dry powder device turbohaler ®, we were unable to analyze the observation concerning this device, since none of the nurses in our sample, wast able to handlle it correctly, before and after training.In general terms, we found that the training given on inhalation therapy had a positive impact either in the theorical or the pratical knowledge on inhalation therapy (higher number of correct answers after training). Similarly, after training, there was the considerable improvement of specific and practical skills, namely the importance of certain procedures in the practice of inhalation therapy - shaking the inhaler, pause time between each inhalation, maintenance care of spacer device, sanitizing the buccal cavity after inhalation of corticosteroids. In contrast, knowledge about drugs administered by inhalation, were slightly below expectations, showing a lower number of correct answers given by the nurses after training. The training seemed to be a factor of "confusion" for this group of nurses, whose prior knowledge in this domais was not probably very solid to begin with. After training, the group of nurses in the study improved the performance of inhalation technique with MDI and MDI with spacer device. They not only correcty performed the steps or itens for the assessment of inhalation technique, previously performed incorrectly, but also showed a better understanding of the steps or itens for assessing the inhalation technique, with fewer steps missing (after training). In contrast, training with regard to the device turbohaler ® dry powder, was also below expectations, given that none of the nurses in the sample was able to demonstrate inhaler technique with this device before and after training. This was probably due to the fact that, the nurses did not feel the need to acquire this knowledge and the related practice. In summary, we can say that, overall, the training (with updated information on the appropriate policies in this field) showed an improvement in knowledge and performance in the practice of inhalation therapy. It is however crucial to underline the importance of in-service adequate training programmes, perceived as useful by the nurses, developped in different phases, linked to the nurses’ practice and combining with professional practices. The nurses’ knowledge and skills should also be further monitorized and evaluated in order to detect deviations introduced by the rotinization of procedures and to identify new training needs.

Analysis of chromium behaviour and speciation during the electrodialytic process

The interest in chromium (Cr) arises from the widespread use of this heavy metal in various industrial processes that cause its release as liquid, solid and gaseous waste into the environment. The impact of Cr on the environment and living organisms primarily depends on its chemical form, since Cr(III) is an essential micronutrient for humans, other animals and plants, and Cr(VI) is highly toxic and a known human carcinogen. This study aimed to evaluate if the electrodialytic process (ED) is an appropriate treatment for Cr removal, through a critical overview of Cr speciation, before and after the ED experiments, to assess possible Cr(III)-Cr(VI) interconversions during the treatment. ED was the treatment technique applied to two types of matrices containing Cr: chromate copper arsenate (CCA) contaminated soil and municipal solid waste incineration (MSWI) fly ash. In order to study Cr remediation, three EDR set-ups were used: a new set-up, the combined cell (2/3C or 3/2C), with three compartments, alternating current between two anodes and different initial experimental conditions, one set-up with three compartments (3C cell) and the other set-up with two compartments (2C cell). The Cr removal rates obtained in this study were between 10-36% for the soil, and 1-13% for the fly ash. The highest Cr removal rates were achieved in the 26 days experiments: 36% for the soil, 13% for the fly ash. Regarding the 13 days experiments, the highest Cr removal rates were attained with the 2/3C set-up: 24% for the soil, 5% for the fly ash. The analysis of Cr(VI) was performed before and after ED experiments to evaluate eventual changes in Cr speciation during the treatment. This analysis was conducted by two methods: USEPA Method 3060A, for the extraction of Cr(VI); and Hach Company Method 8023, for the detection of Cr(VI). Despite the differences in Cr total concentration, both matrices presented a similar speciation, with Cr(III) being the main species found and Cr(VI) less than 3% of Cr total, before and after the treatment. For fly ash, Cr(VI) was initially below the detection limit of the method and remained that way after the treatment. For soil, Cr(VI) decreased after the treatment. Oxidation of Cr(III) to Cr(VI) did not occur during the ED process since there was no increase in Cr(VI) in the matrices after the treatment. Hence, the results of this study indicate that ED is an appropriate technique to remediate matrices containing Cr because it contributes to Cr removal, without causing Cr(III)-Cr(VI) interconversions.

Ion-beam sources based on superionic solid electrolytes

An ion emitter consisting of a sharp silver tip covered in RbAg4I5 solid electrolyte film has been developed and studied. An accelerating potential is applied and Ag+ ions are emitted from the tip’s apex by field evaporation. The emitted ions are collected by a Faraday cup, producing a current on the pico/nanoampere level which is read by an electrometer. The tips were produced mechanically by sandpaper polishing. The sharpest tip produced had a 2:4 m apex radius. Two deposition methods were studied: thermal vacuum and pulsed laser deposition. The best tip produced a peak current value of 96nA at 180oC, and a quasi-stable 4nA emission current at 160oC, both using an extraction potential of 10kV . The emission dependence on time, temperature and accelerating potential has been studied. Deposited films were characterized by X-ray diffraction (XRD), profilometry, optical and Scanning Electron Microscope (SEM) and Secondary Ion Mass Spectroscopy (SIMS) measurements. Several ion emitters were developed, the latter ones were all able to maintain stable high ion emissions for long periods of time. This investigation was a continuation of an ongoing project backed by the European Space Agency, with the objective of making a proof of concept of this kind of ion emitter with potential application on ion thrusters for orbiting satellites. Going forward, it would be interesting to make a finer analysis of the electrolyte’s conductivity at high temperatures, explore Wien Effect-based emission and to further develop a multi-tip ion emitter prototype.

Coupling organic substrate removal to methane production in a fully biological microbial electrolysis cell

Microbial electrolysis cells (MECs) are an innovative and emerging technique based on the use of solid-state electrodes to stimulate microbial metabolism for wastewater treatment and simultaneous production of value-added compounds (such as methane). This research studied the performance of a two-chamber MEC in terms of organic matter oxidation (at the anode) and methane production (at the cathode). MEC‟s anode had been previously inoculated with an activated sludge, whereas the cathode chamber inoculum was an anaerobic sludge (containing methanogenic microorganisms). During the experimentation, the bioanode was continuously fed with synthetic solutions in anaerobic basal medium, at an organic load rate (OLR) of around 1 g L-1 d-1, referred to the chemical oxygen demand (COD). At the beginning (Run I), the feeding solution contained acetate and subsequently (Run II) it was replaced with a more complex solution containing soluble organic compounds other than acetate. For both conditions, the anode potential was controlled at -0.1 V vs. standard hydrogen electrode, by means of a potentiostat. During Run I, over 80% of the influent acetate was anaerobically oxidized at the anode, and the resulting electric current was recovered as methane at the cathode (with a cathode capture efficiency, CCE, accounting around 115 %). The average energy efficiency of the system (i.e., the energy captured into methane relative to the electrical energy input) under these conditions was over 170%. However, reactor‟s performance decreased over time during this run. Throughout Run II, a substrate oxidation over 60% (on COD basis) was observed. The electric current produced (57% of coulombic efficiency) was also recovered as methane, with a CCE of 90%. For this run the MEC‟s average energy efficiency accounted for almost 170 %. During all the experimentation, a very low biomass growth was observed at the anode whereas ammonium was transferred through the cationic membrane and concentrated at the cathode. Tracer experiments and scanning electron microscopy analyses were also carried out to gain a deeper insight into the reactor performance and also to investigate the possible reasons for partial loss of performance. In conclusion, this research suggests the great potential of MEC to successfully treat low-strength wastewaters, with high energy efficiency and very low sludge production.