Tribute to Professor José Simões Redinha on the occasion of his 80th birthday

http://www.sciencedirect.com/science/article/B6WHM-4NCSGV5-1/1/9b3f5b78e88f167357ada24023ebb66

Acquired-Transient Factor X Deficiency in a Teenager with Extensive Burns

Acquired factor X deficiency is an extremely rare situation. It has shown to be associated with systemic amyloidosis, respiratory mycoplasma infection, factor X inhibitors, antiphospholipid antibodies, vitamin K defi ciency/liver disease as well as the use of certain medications (meropenem, valproic acid). The pathogenesis and transient nature of this deficit remain poorly understood. The authors describe the case of a teenager hospitalised for extensive burns that developed active bleeding after removal of central venous catheter. He was diagnosed with transient factor X deficiency. Normalisation of coagulation status and factor X levels occurred spontaneously 10 days after the bleeding episode

O Impacto do Derby de Futebol Lisboeta no Perfil de Admissões a um Serviço de Urgência

BACKGROUND: Variations in emergency department admissions have been reported to happen as a result of major sports events. The work presented assessed changes in volume and urgency level of visits to a major Emergency Department in Lisbon during and after the city's football derby. MATERIAL AND METHODS: Volume of attendances and patient urgency level, according to the Manchester Triage System, were retrospectively analyzed for the 2008-2011 period. Data regarding 24-hour periods starting 45 minutes before kick-off was collected, along with data from similar periods on the corresponding weekdays in the previous years, to be used as controls. Data samples were organized according to time frame (during and after the match), urgency level, and paired accordingly. RESULTS: A total of 14 relevant periods (7 match and 7 non-match) were analyzed, corresponding to a total of 5861 admissions. During the match time frame, a 20.6% reduction (p = 0.06) in the total number of attendances was found when compared to non-match days. MTS urgency level sub-analysis only showed a statistically significant reduction (26.5%; p = 0.05) in less urgent admissions (triage levels green-blue). Compared to controls, post-match time frames showed a global increase in admissions (5.6%; p = 0.45), significant only when considering less urgent ones (18.9%; p = 0.05). DISCUSSION: A decrease in the total number of emergency department attendances occurred during the matches, followed by a subsequent increase in the following hours. These variations only reached significance among visits triaged green-blue. CONCLUSION: During major sports events an overall decrease in emergency department admissions seems to take place, especially due to a drop in visits associated with less severe conditions

Estimating maintenance costs of a wind turbine pitch control system

Wind turbines are nowadays the principal source of wind energy production. However, the technical information publicly known about these machines is still very scarce. Indeed, information related to failure modes, unavailability and maintenance costs of these systems remains confidential and only is held by manufacturers. To be able to optimize the efficiency, to guarantee the security and to negotiate better warranty and maintenance contracts, it is necessary to know more information about the operation and maintenance and replacement costs of subsystems of a wind turbine. To this end, this paper presents a short literature review of what has been published so far about this issue, and, based on two years of operation, analyses an active power control system of 21 identical wind turbines, installed in a wind farm in Portugal. The emphasis of this study is on the operation, availability and maintenance, and replacement costs of the active pitch control device, which automatically manages the position and operation of blades according to wind direction and speed, thus maximizing the electrical power gathered from the natural forces. Moreover, the paper provides an estimation for the total maintenance cost of this device, one of the most important components of the wind turbine, thus allowing wind farm companies to carry out financial and economic analysis of maintenance contracts that probably will be the rationale for better contract negotiations with manufactures. The result and the analyses that have been reported may also contribute for further studies on the reliability and maintenance policies of wind turbines.This work was financed with FEDER Funds by Programa Operacional Fatores de Competitividade – COMPETE and by National Funds by FCT – Fundação para a Ciência e Tecnologia, Project: FCOMP-01-0124-FEDER-022674.info:eu-repo/semantics/publishedVersio

PHM overview on battery models approaches

The Battery Management Systems (BMS) brought a new impetus to the battery energy management which lead to an increase in battery life. But the BMS fails when the State of Charge (SoC), State of Health (SoH), State of Life (SoL) or Remaining Useful Life (RUL) prognostics systems do not provide the required accuracy. Despite the increase of complexity and accuracy of battery models, the poor performance with floating temperature and load profiles persists. With the development of innovative products on wide-ranging applications, the battery materials, technologies, reliability and safety are being pressed to their limits. Therefore, a huge amount of work is still necessary, not only on the development of new battery technologies but also on the BMS, battery models and metrics accuracy improvements. The paper gives a comprehensive overview of the applicability, accuracy, weaknesses and advantages of the most recent battery models. The paper will also discuss how the Prognostics Health Management (PHM) can support a technologic impetus on battery affairs with battery models and metrics accuracy improvements.info:eu-repo/semantics/publishedVersio

Risk Analysis and Behavior of Electricity Portfolio Aggregator

The scope of this paper is to adapt the standard mean-variance model of Henry Markowitz theory, creating a simulation tool to find the optimal configuration of the portfolio aggregator, calculate its profitability and risk. Currently, there is a deep discussion going on among the power system society about the structure and architecture of the future electric system. In this environment, policy makers and electric utilities find new approaches to access the electricity market; this configures new challenging positions in order to find innovative strategies and methodologies. Decentralized power generation is gaining relevance in liberalized markets, and small and medium size electricity consumers are also become producers (“prosumers”). In this scenario an electric aggregator is an entity that joins a group of electric clients, customers, producers, “prosumers” together as a single purchasing unit to negotiate the purchase and sale of electricity. The aggregator conducts research on electricity prices, contract terms and conditions in order to promote better energy prices for their clients and allows small and medium customers to benefit improved market prices

Solvation of alkane and alcohol molecules. Energy contributions

In this work we conduct a systematic ab initio study of the solvation of small alkane, monoalcohol and diol molecules, in polar solvents with different properties. A choice of basis set suitable for the type of compounds under study is presented. The various components of the solvent–solute interaction and the cavitation energy are treated individually and their variation with chain length and introduction of hydroxy groups assessed. The use of solute molecules in which controlled changes are imposed allows for an estimation of the relative contributions, thus eliminating accidental error cancellation.Fundacão para a Ciência e Tecnologia SAPIENS POCTI/35415/QUI/200

Commercial agents portfolio optimization in electricity markets

As it is well known, competitive electricity markets require new computing tools for power companies that operate in retail markets in order to enhance the management of its energy resources. During the last years there has been an increase of the renewable penetration into the micro-generation which begins to co-exist with the other existing power generation, giving rise to a new type of consumers. This paper develops a methodology to be applied to the management of the all the aggregators. The aggregator establishes bilateral contracts with its clients where the energy purchased and selling conditions are negotiated not only in terms of prices but also for other conditions that allow more flexibility in the way generation and consumption is addressed. The aggregator agent needs a tool to support the decision making in order to compose and select its customers' portfolio in an optimal way, for a given level of profitability and risk

Commercial agentes portfolio optimization in electricity markets

As it is well known, competitive electricity markets require new computing tools for power companies that operate in retail markets in order to enhance the management of its energy resources. During the last years there has been an increase of the renewable penetration into the micro-generation which begins to co-exist with the other existing power generation, giving rise to a new type of consumers. This paper develops a methodology to be applied to the management of the all the aggregators. The aggregator establishes bilateral contracts with its clients where the energy purchased and selling conditions are negotiated not only in terms of prices but also for other conditions that allow more flexibility in the way generation and consumption is addressed. The aggregator agent needs a tool to support the decision making in order to compose and select its customers' portfolio in an optimal way, for a given level of profitability and risk

Molecular structure and polymorphism of a cyclohexanediol: trans-1,4-cyclohexanedimethanol

This study aims to investigate the molecular structure and polymorphism of trans-1,4-cyclohexanedimethanol, including the bi-axial/bi-equatorial equilibrium and the nature of the intermolecular H-bond networks in condensed phases created by the hydroxyl group torsions. The full conformational space of the single molecule was explored by MP2 calculations, showing that the optimized bi-equatorial conformers have similar stability and the bi-axial ones have much higher energies. The hydroxymethyl substituents have preference for gauche/anti or gauche+/gauche− conformations. Polymorphic forms were generated by crystallization from solutions and by cooling the melt, which were characterized by a combination of techniques: DSC, PLTM and XRD. Two polymorphs were isolated and their crystal structures were solved by direct methods based on single-crystal X-ray analysis. Both were found to contain two of the most stable conformers found in the computational calculations. The influence of H-bonding in the polymorphic structures was verified by analysis of the structural differences between the geometries present in the polymorphs determined by XRD and their single molecule counterparts resulting from the theoretical calculations. The bi-axial conformations are destabilized over the bi-equatorial ones in isolated and crystalline forms of trans-1,4-cyclohexanedimethanol