21 resultados para Transport Resilience
Resumo:
The initial goal of this work was the development of a supported liquid membrane (SLM) bioreactor for the remediation of vaccine production effluents contaminated with a highly toxic organomercurial – thiomersal. Therefore, two main aspects were focused on: 1) the development of a stable supported liquid membrane – using room temperature ionic liquids (RTILs) – for the selective transport of thiomersal from the wastewater to a biological compartment, 2) study of the biodegradation kinetics of thiomersal to metallic mercury by a Pseudomonas putida strain. The first part of the work focused on the evaluation of the physicochemical properties of ionic liquids and on the SLMs’ operational stability. The results obtained showed that, although it is possible to obtain a SLM with a high stability, water possesses nonnegligible solubility in the RTILs studied. The formation of water clusters inside the hydrophobic ionic liquid was identified and found to regulate the transport of water and small ions. In practical terms, this meant that, although it was possible to transport thiomersal from the vaccine effluent to the biological compartment, complete isolation of the microbial culture could not be guaranteed and the membrane might ultimately be permeable to other species present in the aqueous vaccine wastewater. It was therefore decided not to operate the initially targeted integrated system but, instead, the biological system by itself. Additionally, attention was given to the development of a thorough understanding of the transport mechanisms involved in the solubilisation and transport of water through supported liquid membranes with RTILs as well as to the evaluation of the effect of water uptake by the SLM in the transport mechanisms of water-soluble solutes and its effect on SLM performance. The results obtained highlighted the determinant role played by water – solubilised inside the ionic liquids – on the transport mechanism. It became clear that the transport mechanism of water and water-soluble solutes through SLMs with [CnMIM][PF6] RTILs was regulated by the dynamics of water clusters inside the RTIL, rather than by molecular diffusion through the bulk of the ionic liquid. Although the stability tests vi performed showed that there were no significant losses of organic phase from the membrane pores, the formation of water clusters inside the ionic liquid, which constitute new, non-selective environments for solute transport, leads to a clear deterioration of SLM performance and selectivity. Nevertheless, electrical impedance spectroscopy characterisation of the SLMs showed that the formation of water clusters did not seem to have a detrimental effect on the SLMs’ electrical characteristics and highlighted the potential of using this type of membranes in electrochemical applications with low resistance requirements. The second part of the work studied the kinetics of thiomersal degradation by a pure culture of P. putida spi3 strain, in batch culture and using a synthe tic wastewater. A continuous ly stirred tank reactor fed with the synthetic wastewater was also operated and the bioreactor’s performance and robustness, when exposed to thiomersal shock loads, were evaluated. Finally, a bioreactor for the biological treatment of a real va ccine production effluent was set up and operated at different dilution rates. Thus it was possible to treat a real thiomersal-contaminated effluent, lowering the outlet mercury concentration to values below the European limit for mercury effluent discharges.
Resumo:
FEMS Yeast Research, Vol. 9, nº 4
Resumo:
River Flow 2010
Resumo:
Dissertação para a obtenção de grau de doutor em Bioquímica pelo Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa
Resumo:
Baseado no relatório realizado para a unidade lectiva “Métodos de Análise Prospectiva” do Programa Doutoral em Avaliação de Tecnologia, 2011
Resumo:
Based on a poster submitted to CONCORD 2011 - Conference on Corporate R&D: The dynamics of Europe's industrial structure and the growth of innovative firms, Sevilla, IPTS, 6 Out. 2011, Seville, http://www.eventisimo.com/concord2011/recibido.html
Resumo:
Canadian Journal of Civil Engineering 36(10) 1605–16
Resumo:
Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies.
Resumo:
Dissertação para obtenção do Grau de Doutor em Engenharia Industrial
Resumo:
Dissertação para obtenção do Grau de Mestre em Engenharia Civil – Perfil de Estruturas
Watershed-scale runoff routing and solute transport in a spatially aggregated hydrological framework
Resumo:
Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies
Resumo:
Complex problems of globalized society challenge its adaptive capacity. However, it is precisely the nature of these human induced problems that provide enough evidence to show that adaptability may not be on a resilient path. This thesis explores the ambiguity of the idea of adaptation (and its practice) and illustrates the ways in which adaptability contributes to resilience of social ecological systems. The thesis combines a case study and grounded theory approach and develops an analytical framework to study adaptability in resource users’ organizations: from what it depends on and what the key challenges are for resource management and system resilience. It does so for the specific case of fish producers’ organizations (POs) in Portugal. The findings suggest that while ecological and market context, including the type of crisis, may influence the character of fishers’ adaptation within POs (i.e. anticipatory, maladaptive and reactively adaptive), it does not determine it. Instead, it makes agency even more crucial (i.e. leadership, trust and agent’s perceptions in terms of their impact on fishers’ motivation to learn from each other). In sum, it was found that internal adaptation can improve POs’ contribution to fishery management and resilience, but it is not a panacea and may, in some cases, increase system vulnerability to change. Continuous maladaptation of some Portuguese POs points at a basic institutional problem (fish market regime), which clearly reduces fisheries resilience as it promotes overfishing. However, structural change may not be sufficient to address other barriers to Portuguese fishers’ (PO members) adaptability, such as history (collective memory) and associated problematic self-perceptions. The agency (people involved in structures and practices) also needs to change. What and how institutional change and agency change build on one another (e.g. comparison of fisheries governance in Portugal and other EU countries) is a topic to be explored in further research.
Resumo:
The purpose of this thesis is to study the impact of a port strike on companies that perform as logistic service providers in a supply chain (SC), here denominated 3PL (third-party logistic providers). These companies are highly dependent on ports to perform their activity, since they provide international services. Consequently, a disruption in a port can seriously impair their business. A stevedores’ strike is one of the possible disruptions that can affect ports. This study aims to analyze the negative effects caused by this disruption, and what strategies 3PLs may implement in order to keep their performance levels stable and have a quick recovery time. Within this objective, the first step will be to establish a theoretical context about the maritime port’s sector and 3PLs in a SC context, to then expand the concept of a resilient SC, and finally to develop a theoretical framework in order to better contextualize the case study. Subsequently, the impact of a port strike will be quantified by using a case study comprising three companies, covering the areas of land and sea distribution and port operations. Information from primary sources was assembled in two phases: first via e-mail and, in a second phase, through a personal interview. The information from secondary sources was obtained through television news, internet and conferences, enabling its cross-analysis. Finally, by analyzing the collected data, it will be possible to draw conclusions about the measures carried out by each company to minimize the negative effects of the strike, thus contributing to a more resilient SC. As a conclusion, a stevedores’ strike will create a snow-ball of negative effects in the SC, degrading all relevant KPIs (key performance indicators) of the 3PLs under study. No mitigation and contingency strategies available proved really effective to reduce the negative effects of a port strike disruption.
Resumo:
Fundação para a Ciência e Tecnologia - EXPL/BBB-BEP/0274/2012
Resumo:
The concept of organizational resilience has become popular in Organizational Studies during the last decades - yet researchers have not been able to find one commonly accepted definition for what exactly it is. What are the drivers of resilience in organizations? Are there certain cultural factors and national differences regarding the perception of the concept? This paper aims to answer these questions from a perspective of within institutions. A group of managers from different corporations in Portugal and Germany has been interviewed in order to understand how managers experience and characterize organizational resilience. Based on qualitative inductive research the results show that organizational resilience is built on four main drivers: a sense of proximity, a sense of openness, a sense of challenge and a sense for structure.