Reconstruir as fronteiras do mercado através de uma estratégia híbrida sustentável

Mestrado em Gestão e Empreendedorismo

Fast screening procedure for antibiotics in wastewaters by direct HPLC-DAD analysis

Growing concern about the contamination of wastewaters by antibiotics demands fast but sensitive analytical methodologies, for the screening of a large number of samples. The purpose of this work was to develop a simple methodology, using direct injection of the samples, by HPLC with diode array detection (DAD), for a multiresidue analysis of five antibiotics of different classes. Wastewater from an urban water treatment plant was selected as a model to study possible coelution of interfering compounds. The linearity interval ranged from 40 to 400 µg/L for amoxicillin (Amox), metronidazole (Metro), cefazolin (Cefa), and chloramphenicol (Chloram) and from 20 to 200 µg/L for sulfamethoxazole (Sulfa), with LODs lower than 14 µg/L. Repeatability, expressed by the CV of six repeated injections, ranged from 1 to 8%, while the intermediate precision varied between 2 and 11%. The recovery ranged from 90 to 109%. This method enables the fast screening of a large number of samples, with an expanded uncertainty in the 1–22% range. The advantage of the proposed method is to significantly reduce the number of samples to be analyzed by more complex methods.

Transformations induced in bulk amorphous silica by ultrafast laser direct writingTransformations induced in bulk amorphous silica by ultrafast laser direct writing

Agências Financiadoras: Fundação para a Ciência e a Tecnologia - PTDC/FIS/102127/2008 e PTDC/FIS/102127/2008 e SFRH/BPD/78871/2011; Spanish Ministerio de Ciencia e Innovacion - FUNCOAT-CSD2008-00023-CONSOLIDER; Instituto Superior Técnico;

Direct electroanalytical determination of fluvastatin in a pharmaceutical dosage form: batch and flow analysis

The reduction of luvastatin (FLV) at a hanging mercury-drop electrode (HMDE) was studied by square-wave adsorptive-stripping voltammetry (SWAdSV). FLV can be accumulated and reduced at the electrode, with a maximum peak current intensity at a potential of approximately 1.26V vs. AgCl=Ag, in an aqueous electrolyte solution of pH 5.25. The method shows linearity between peak current intensity and FLV concentration between 1.0 10 8 and 2.7 10 6 mol L 1. Limits of detection (LOD) and quantification (LOQ) were found to be 9.9 10 9 mol L 1 and 3.3 10 8 mol L 1, respectively. Furthermore, FLV oxidation at a glassy carbon electrode surface was used for its hydrodynamic monitoring by amperometric detection in a flow-injection system. The amperometric signal was linear with FLV concentration over the range 1.0 10 6 to 1.0 10 5 mol L 1, with an LOD of 2.4 10 7 mol L 1 and an LOQ of 8.0 10 7 mol L 1. A sample rate of 50 injections per hour was achieved. Both methods were validated and showed to be precise and accurate, being satisfactorily applied to the determination of FLV in a commercial pharmaceutical.

Natural waste materials containing chitin as adsorbents for textile dyestuffs: batch and continuous studies

In this work three natural waste materials containing chitin were used as adsorbents for textile dyestuffs, namely the Anodonta (Anodonta cygnea) shell, the Sepia (Sepia officinalis) and the Squid (Loligo vulgaris) pens. The selected dyestuffs were the Cibacron green T3G-E (CI reactive green 12), and the Solophenyl green BLE 155% (CI direct green 26), both from CIBA, commonly used in cellulosic fibres dyeing, the most used fibres in the textile industry. Batch equilibrium studies showed that the materials’ adsorption capacities increase after a simple and inexpensive chemical treatment, which increases their porosity and chitin relative content. Kinetic studies suggested the existence of a high internal resistance in both systems. Fixed bed column experiments performed showed an improvement in adsorbents’ behaviour after chemical treatment. However, in the column experiments, the biodegradation was the main mechanism of dyestuff removal, allowing the materials’ bioregeneration. The adsorption was strongly reduced by the pore clogging effect of the biomass. The deproteinised Squid pen (grain size 0.500–1.41 mm) is the adsorbent with highest adsorption capacity (0.27 and 0.037 g/g, respectively, for the reactive and direct dyestuffs, at 20ºC), followed by the demineralised Sepia pen and Anodonta shell, behaving like pure chitin in all experiments, but showing inferior performances than the granular activated carbon tested in the column experiments.

Análise de tecnologias de impermeabilização e isolamento em reabilitação da envolvente de edifícios

Neste trabalho é abordado o estágio efectuado por um período de sete meses na E.A. (Engenheiros Associados) e um estudo de caso sobre as tecnologias aplicadas no isolamento térmico de paredes exteriores. Na primeira parte deste relatório é efectuada uma breve caracterização da empresa e da sua actividade no mercado. A Engenheiros e Associados tem a sua estrutura assente nos seguintes sectores: Técnico-Comercial, de Aprovisionamento e de Gestão Administrativa; da qual foi efectuada uma descrição do trabalho desenvolvido em cada um desses sectores, nomeadamente a permanência na obra e as visitas e diligências às obras. A segunda parte deste relatório, que é a parte fulcral do trabalho desenvolvido, assenta sobre o sistema de ETICS (External Thermal Insulation Composite System), ou seja, o sistema de reboco delgado armado sobre isolamento térmico. Foi utilizado o sistema Cappotto na Obra de Requalificação da Urbanização de Vila d’Este – 1ª Fase. Após uma breve apresentação e evolução da história do ETICS ao longo do tempo, é exposta a caracterização da obra onde vai ser aplicado o sistema, que recai sobre a tipologia dos edifícios. Refira-se que, neste relatório, os edifícios por serem de construção túnel se dividem em três tipos: tipo plana ou corrente, tipo ângulo e tipo topo. Na Analise de Patologias efectuada evidenciam-se as fissuras e a humidade presentes em quase toda a extensão dos referidos edifícios antes do tratamento, tornando-as assim as principais anomalias destes edifícios. Foram elemento de foco as anomalias existentes nos edifícios, como: Deterioração do fibrocimento; Insuficiência das caleiras; Deficiências das impermeabilizações; Ausência de rufos; Deficiência das ligações; Degradação do revestimento e pintura; Fissuração do reboco; Degradação dos forros exteriores; Deterioração das padieiras; Deterioração dos peitoris; Deterioração das juntas de dilatação; Infiltrações e condensações; Ruptura das canalizações; Deslocamentos; Deficiências de ventilação; Deficiências de estanqueidade; Inexistência de Sistema de combate a incêndios. Para estas patologias são apresentadas as propostas de solução de forma a eliminar as mesmas. Sendo o ETICS escolhido por ser o sistema que elimina a maior parte destas patologias, tendo em conta uma relação de qualidade/preço, é abordada de uma forma detalhada e extensiva da aplicação do sistema antes, durante e depois da obra em si. Assim como, é feita uma descrição pormenorizada do material utilizado para a implementação do sistema. A análise dos pontos críticos refere-se a zonas sensíveis onde há a necessidade de reforço do sistema com vista a eliminar o aparecimento posterior de patologias, como por exemplo as características de suporte. Após a aplicação do sistema podem aparecer algumas patologias das quais se destaca o facto dos produtos serem preparados em obra, o erro humano nas dosagens do fabricante e no acrescento de água sem necessidade e a par das condições climatéricas, são as causas mais comuns do aparecimento de anomalias no sistema de ETICS, provocando fissurações e infiltrações, que são descritas neste relatório. É também abordada a manutenção e reparação do sistema, onde a manutenção refere-se à lavagem e à remoção de microorganismos das paredes e posterior pintura. A reparação dos danos divide-se em dois tipos, áreas até 2 cm2 e áreas maiores que 2 cm2. Por fim, são apresentados alguns rendimentos, que foram possíveis obter ao longo do desenvolvimento do trabalho, dos materiais e da mão-de-obra, dando origem aos custos directos. Sendo também abordadas as vantagens e desvantagens do sistema desde o seu início até à sua conclusão.

Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1±4.3 % to 264.7±3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3±1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5±2.0 % to 118.8±1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect.

Fracture toughness determination of adhesive and co-cured joints in natural fibre composites

Adhesive bonding has become more efficient in the last few decades due to the adhesives developments, granting higher strength and ductility. On the other hand, natural fibre composites have recently gained interest due to the low cost and density. It is therefore essential to predict the fracture behavior of joints between these materials, to assess the feasibility of joining or repairing with adhesives. In this work, the tensile fracture toughness (Gc n) of adhesive joints between natural fibre composites is studied, by bonding with a ductile adhesive and co-curing. Conventional methods to obtain Gc n are used for the co-cured specimens, while for the adhesive within the bonded joint, the J-integral is considered. For the J-integral calculation, an optical measurement method is developed for the evaluation of the crack tip opening and adherends rotation at the crack tip during the test, supported by a Matlab sub-routine for the automated extraction of these quantities. As output of this work, an optical method that allows an easier and quicker extraction of the parameters to obtain Gc n than the available methods is proposed (by the J-integral technique), and the fracture behaviour in tension of bonded and co-cured joints in jute-reinforced natural fibre composites is also provided for the subsequent strength prediction. Additionally, for the adhesively- bonded joints, the tensile cohesive law of the adhesive is derived by the direct method.

Análise do sistema de tratamento de efluentes gasosos de uma central de valorização energética de resíduos sólidos urbanos

Trabalho Final de Mestrado para obtenção do grau de Mestre Em Engenharia Química e Biológica Ramo de processos Químicos

Fusão de hospitais em centros hospitalares : impacto no seu desempenho operacional e financeiro

Mestrado em Contabilidade e Análise Financeira

Sistemas de arrefecimento de instalações frigoríficas utilizando três agentes frigoríficos

Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia Mecânica

Direct electrochemistry of the Desulfovibrio gigas aldehyde oxidoreductase

Eur. J. Biochem. 271, 1329–1338 (2004)

Regional governance: strategies and disputes in health region management

OBJECTIVE To analyze the regional governance of the health systemin relation to management strategies and disputes.METHODOLOGICAL PROCEDURES A qualitative study with health managers from 19 municipalities in the health region of Bahia, Northeastern Brazil. Data were drawn from 17 semi-structured interviews of state, regional, and municipal health policymakers and managers; a focus group; observations of the regional interagency committee; and documents in 2012. The political-institutional and the organizational components were analyzed in the light of dialectical hermeneutics.RESULTS The regional interagency committee is the chief regional governance strategy/component and functions as a strategic tool for strengthening governance. It brings together a diversity of members responsible for decision making in the healthcare territories, who need to negotiate the allocation of funding and the distribution of facilities for common use in the region. The high turnover of health secretaries, their lack of autonomy from the local executive decisions, inadequate technical training to exercise their function, and the influence of party politics on decision making stand as obstacles to the regional interagency committee’s permeability to social demands. Funding is insufficient to enable the fulfillment of the officially integrated agreed-upon program or to boost public supply by the system, requiring that public managers procure services from the private market at values higher than the national health service price schedule (Brazilian Unified Health System Table). The study determined that “facilitators” under contract to health departments accelerated access to specialized (diagnostic, therapeutic and/or surgical) services in other municipalities by direct payment to physicians for procedure costs already covered by the Brazilian Unified Health System.CONCLUSIONS The characteristics identified a regionalized system with a conflictive pattern of governance and intermediate institutionalism. The regional interagency committee’s managerial routine needs to incorporate more democratic devices for connecting with educational institutions, devices that are more permeable to social demands relating to regional policy making.

A lightweight indoor localization model based on motley-keenan and COST

This paper presents a novel approach to WLAN propagation models for use in indoor localization. The major goal of this work is to eliminate the need for in situ data collection to generate the Fingerprinting map, instead, it is generated by using analytical propagation models such as: COST Multi-Wall, COST 231 average wall and Motley- Keenan. As Location Estimation Algorithms kNN (K-Nearest Neighbour) and WkNN (Weighted K-Nearest Neighbour) were used to determine the accuracy of the proposed technique. This work is based on analytical and measurement tools to determine which path loss propagation models are better for location estimation applications, based on Receive Signal Strength Indicator (RSSI).This study presents different proposals for choosing the most appropriate values for the models parameters, like obstacles attenuation and coefficients. Some adjustments to these models, particularly to Motley-Keenan, considering the thickness of walls, are proposed. The best found solution is based on the adjusted Motley-Keenan and COST models that allows to obtain the propagation loss estimation for several environments.Results obtained from two testing scenarios showed the reliability of the adjustments, providing smaller errors in the measured values values in comparison with the predicted values.

Filters method in direct search optimization, new measures to admissibility

Constrained nonlinear optimization problems are usually solved using penalty or barrier methods combined with unconstrained optimization methods. Another alternative used to solve constrained nonlinear optimization problems is the lters method. Filters method, introduced by Fletcher and Ley er in 2002, have been widely used in several areas of constrained nonlinear optimization. These methods treat optimization problem as bi-objective attempts to minimize the objective function and a continuous function that aggregates the constraint violation functions. Audet and Dennis have presented the rst lters method for derivative-free nonlinear programming, based on pattern search methods. Motivated by this work we have de- veloped a new direct search method, based on simplex methods, for general constrained optimization, that combines the features of the simplex method and lters method. This work presents a new variant of these methods which combines the lters method with other direct search methods and are proposed some alternatives to aggregate the constraint violation functions.