Análise de sistemas híbridos com células a combustível de oxido sólido e microturbinas a gás

The following work presents a study of the simulation of high Fuel Cells temperature, SOFC, and the operation integrated with gas microturbines into combined cycle. The principal aim is to reach high fuel utilization efficiencies cycles. Three mathematical models are developed for the SOFC study and a commercial program of simulation is used for simulation of the microturbina integrated in to SOFC using and supplying the exit and entrance data of SOFC, respectively. It is made an evaluation of the influences of the temperature and pressure in the SOFC operation, alone and integrated with the micro turbine. Two different configurations are evaluated: pressurized and atmospheric pressure operating. It is also made an evaluation of these two systems operating in partial loads.O seguinte trabalho apresenta uma analise de células a combustível de alta temperatura, SOFC, e sua operação integrada com microturbinas a gás em ciclo combinado. Para isto são desenvolvidos diferentes modelos de simulação, se partido de uma célula simples até uma planta integrada. O objetivo principal é avaliar ciclos com elevada eficiência de utilização do combustível. São desenvolvidos três modelos matemáticos para o estudo da SOFC e se utiliza um programa de simulação comercial para simulação da microturbina integrada à SOFC utilizando e fornecendo os dados de saída e entrada da SOFC respectivamente. Com os modelos desenvolvidos é feita uma avaliação da influencia da temperatura e pressão na operação da SOFC isolada e integrada com a microturbina a gás. São utilizadas configurações diferentes: SOFC pressurizada pela própria turbina gás e operando a pressão atmosférica. Também é feita uma avaliação destes dois sistemas operando em cargas variáveis

Balance embólico-hemorrágico en el paciente anciano con fibrilación auricular

El envejecimiento progresivo de la población está condicionando un aumento en la prevalencia de enfermedades crónicas como la fibrilación auricular (FA). En la práctica clínica, establecer el balance embólico-hemorrágico del paciente anciano con FA supone un gran reto que dificulta la toma de decisiones, especialmente en lo que respecta al inicio o continuación del tratamiento anticoagulante. El objetivo de la presente tesis es analizar el riesgo embólico, hemorrágico y la mortalidad de una cohorte nacional de pacientes ancianos con FA . Por otro lado, prentendemos evaluar el impacto de la edad extrema, del estado nutricional o del deterioro cognitivo en el balance embólico-hemorrágico. En nuestro trabajo observamos que, en pacientes ancianos con FA, la anticoagulación oral (ACO) se asocia de forma significativa con una menor mortalidad y un menor número de eventos embólicos, así como con un aumento del riesgo de sangrado. Hemos observado un beneficio de la ACO en pacientes nonagerios, especialmente en aquellos tratados con un anticoagulante de acción directa (ACOD) Sin embargo, el balance embólico-hemorrágico resultó neutro o negativo (predominio de eventos hemorrágicos mayores) en pacientes ancianos con algún grado de malnutrición o con demencia de grado al menos moderado. Por todo ello, concluimos que se debería realizar una aproximación individualizada al balance embólico-hemorrágico en todo paciente anciano con FA mediante una valoración geriátrica integral que incluya el estado nutricional y el grado de demencia

Functional consequences of microbial shifts in the human gastrointestinal tract linked to antibiotic treatment and obesity

The microbiomes in the gastrointestinal tract (GIT) of individuals receiving antibiotics and those in obese subjects undergo compositional shifts, the metabolic effects and linkages of which are not clearly understood. Herein, we set to gain insight into these effects, particularly with regard to carbohydrate metabolism, and to contribute to unravel the underlying mechanisms and consequences for health conditions. We measured the activity level of GIT carbohydrate-active enzymes toward 23 distinct sugars in adults patients (n = 2) receiving 14-d β-lactam therapy and in obese (n = 7) and lean (n = 5) adolescents. We observed that both 14 d antibiotic-treated and obese subjects showed higher and less balanced sugar anabolic capacities, with 40% carbohydrates being preferentially processed as compared with non-treated and lean patients. Metaproteome-wide metabolic reconstructions confirmed that the impaired utilization of sugars propagated throughout the pentose phosphate metabolism, which had adverse consequences for the metabolic status of the GIT microbiota. The results point to an age-independent positive association between GIT glycosidase activity and the body mass index, fasting blood glucose and insulin resistance (r2 ≥ 0.95). Moreover, antibiotics altered the active fraction of enzymes controlling the thickness, composition and consistency of the mucin glycans. Our data and analyses provide biochemical insights into the effects of antibiotic usage on the dynamics of the GIT microbiota and pin-point presumptive links to obesity. The knowledge and the hypotheses generated herein lay a foundation for subsequent, systematic research that will be paramount for the design of “smart” dietary and therapeutic interventions to modulate host-microbe metabolic co-regulation in intestinal homeostasis

Analysis of labour market needs for engineers with enhanced knowledge in renewable energy in some European and Latin-American Countries

One of the main challenges related to the renewable energy labour market is that of human capital and as a consequence the educational profile of future employees is of paramount importance. Unfortunately, the skill level gained at University does not always fit with the practical needs of industry thus reducing the benefit-cost ratio of new employees and slowing down the transition to a green economy. Within this context, ‘The Crux’ project co-funded by EU under the framework of the Erasmus + programme aims at improving the renewable energy engineering curriculum at different university levels in several Universities of Latin America and Europe. In order to better appreciate the potential impact of the project, a survey on the labour market need for specialists with enhanced knowledge and skills in renewable and sustainable energy technologies has been conducted in the related EU and Latin America countries. More precisely, 60 organizations have been interviewed and almost 70% of them are interested in employing engineers with enhanced knowledge on renewable energy in the next three years. The analysis has shown significant discrepancies between EU and Latin American organizations. In fact, while future employees in EU countries will be mainly related to solar energy and management, the former together with wind and biomass will represent the main renewable energy working sector in Latin American countries. Moreover, MSc level will be the most demanded in EU while bachelor education seems to satisfy the future industry requirements in Latin America. Despite each country having its own needs, the research carried out under this EU project confirms the potential of renewable energy education on the global labour market in the near future

Legacy and emerging pollutants in marine bivalves from the Galician coast (NW Spain)

The presence of pollutants in estuary and oceanic systems is a global problem and a serious concern to human and environmental health. Usually, environmental monitoring studies consider classical persistent organic pollutants (POPs). However, the lists of POPs keep continuously growing and new POPs and other emerging pollutants should be considered in new monitoring programs. So, this study aimed to investigate the distribution and profile of classical POPs (polychlorinated biphenyl (PCBs), organochlorine pesticides (OCPs), and polycyclic aromatic hydrocarbons (PAHs)), new POPs and emerging pollutants (polybrominated diphenyl ethers (PBDEs), perfluorinated compounds (PFCs), novel halogenated flame retardants (NFRs) and UV filters) in bivalve mollusc samples (both raft-cultivated and wild mussel, Mytilus galloprovincialis; cockle, Cerestoderma edule; and clam, Ruditapes descussatus) collected in nine Galician Rias during the period February 2012 to February 2013. A predominance of PAHs (6.8–317 ng/g dry weight (dw)) followed by PCBs (0.47–261 ng/g dw), UV filters (1.4–157 ng/g dw), PFCs (0.53–62 ng/g dw), OCPs (0.07–29 ng/g dw), PBDEs (0.31–6.6 ng/g dw) and NFRs (0.07–3.2 ng/g dw) was found in the studied bivalves, being the UV filter octocrylene the compound found at the highest concentration (141 ng/g dw in a cockle sample), while the PAHs chrysene and benzo(b)fluoranthene were the compounds with the highest average concentration (20 and 14 ng/g dw, respectively). Inter-species, temporal and geographical variations on pollutants concentration were assessed by multifactorial analysis of variance. Statistically significant differences among the type of mollusc were observed for levels of organochlorinated and organobrominated pollutants considered (PCBs, OCPs and PBDEs), which were detected at higher concentrations in wild mussel. On the other hand, the main PFCs and UV filters showed a higher detection frequency in cockle samples. Location played significant role for PAHs, PCBs and the main PBDEs, being the most polluted rias those more industrialized and populated, i.e. A Coruña, Ferrol and/or Vigo. Finally, sampling timepoint was also a significant factor for most of the families considered but with different profiles. Thus, PAHs and PCBs showed higher concentrations in both February 2012 and 2013 and lower in August 2012, while the main PBDEs were measured at higher concentrations in November 2012 and lower in February 2012; and the main NFRs, PFCs and UV filters were present at lower levels in February 2013The authors acknowledge the financial support provided by Galician Government (Conselleria de Economía e Industria, Xunta de Galicia) in the framework of Projects 10MDS700006PR and ED431C2017/36 and by the Spanish Government through the Research Projects CTM2014-56628-C3-2-R, CTM2017-84763-C3-2-R and FEDER fundsS

Evaluation of energy forecasting mechanisms with renewable sources for maximizing the brazilian energy matrix using machine learning

The present study focuses on the Brazilian energy scenario and highlights the progressive increase in the use of renewable sources in the country's electricity matrix. The main objective of this study is to contribute to the search for solutions and to stimulate debates and reflections on the future actions necessary for energy planning. To achieve this, the research employs computational tools based on machine learning and data mining, using government and energy market data sources. The research methodology encompasses the use of computational tools to project the forecast of the electricity market in the country. The methodology employed includes the execution of forecasting models, highlighting the behavior of the energy market over time, using methods such as Multilayer Perceptron Neural Networks (MLP), Gaussian Process Regression (GPR), and Linear Regression to project electricity generation by source in Brazil. The results indicate a considerable growth of renewable sources in the national energy market by the year 2030, approaching the goal of the Ten-Year Energy Expansion Plan to achieve 90% renewability, covering sources such as hydroelectric, biomass, wind, and solar. The Linear Regression method achieved 86% renewability, while the GPR method reached 90%, and the MLP method reached 88%. The projection of the electricity market forecast allowed for the identification of market behavior patterns, enabling the anticipation of trends and changes in the market. These forecasts aim to provide information to support the development of actions in the energy planning process, contributing to the transition to more sustainable and renewable energy sources in Brazil.O presente estudo concentra-se no cenário energético brasileiro e destaca o aumento progressivo do uso de fontes renováveis na matriz de energia elétrica do país. O principal objetivo deste trabalho é contribuir para a busca de soluções e impulsionar debates e reflexões sobre as ações futuras necessárias para o planejamento energético. Para isso, a pesquisa emprega ferramentas computacionais baseadas em machine learning e mineração de dados, utilizando fontes de dados governamentais e de mercado de energia. A metodologia abrange a utilização de ferramentas computacionais para projetar a previsão do mercado de energia elétrica no país, inclui a execução de modelos de previsão, destacando o comportamento do mercado energético ao longo do tempo, a partir dos métodos Redes Neurais Multilayer Perceptron (MLP), Regressão do Processo Gaussiano (GPR) e Regressão Linear para projetar a geração elétrica por fonte no Brasil. Os resultados indicam um crescimento considerável das fontes renováveis no mercado energético nacional até o ano de 2030, aproximando-se do objetivo do Plano Decenal de Expansão de Energia de atingir 90% de renovabilidade, abrangendo fontes como hidrelétrica, biomassa, eólica e solar. O método de Regressão Linear alcançou 86% de renovabilidade, enquanto o método de GPR atingiu 90%, e o método das MLP chegou a 88%. A projeção da previsão do mercado de energia elétrica, possibilitou a identificação dos padrões de comportamento mercadológico, permitindo antecipar as tendências e mudanças no mercado. Essas previsões têm o propósito de fornecer informações para apoiar o desenvolvimento de ações no processo de planejamento energético, contribuindo para a transição para fontes mais sustentáveis e renováveis de energia no Brasil

Identificación y comportamiento de la fauna entomológica asociada a la vegetación existente en dos fincas suburbanas en Santiago de Cuba, Cuba

Resumen. La fauna entomológica es un componente importante en los sistemas agrícolas. Sin embargo no siempre se le ha dado el valor que merece. El trabajo tuvo como objetivo identificar y evaluar el comportamiento de la fauna entomológica asociada a la vegetación existente en dos fincas de la agricultura suburbana en Santiago de Cuba, Cuba. Se realizaron muestreos directos, los insectos recolectados fueron conservados en etanol al 70% y luego se procedió a su identificación. Se contabilizaron aquellas especies que pertenecieron a una misma categoría taxonómica evaluándose la composición insectil. Se calculó la Riqueza de Margalef (DMg), Dominancia de Simpson (DSp), Índice de Berger-Parker (d) y Diversidad general (Shannon H´) como indicadores de diversidad alfa. Como medida de similitud (diversidad beta) se utilizaron los índices de Jaccard (Ij), Morisita-Horn (I) y Subordinación Ecológica (SE). Fueron recolectados 1.592 individuos, pertenecientes a cinco órdenes, 20 familias, 30 géneros y 31 especies. Los órdenes más representados fueron Coleoptera, Hemiptera e Hymenoptera, y los gremios tróficos con mayor presencia en ambos períodos fueron los fitófagos y los controladores biológicos (depredadores y parasitoides). La diversidad alfa disminuyó del período poco lluvioso al lluvioso, con valores de diversidad general dentro del rango establecido solo en la temporada poco lluviosa de la finca La Caballería. Existe una baja similitud entre las fincas que se compararon, evidenciando la presencia de pocas especies comunes, siendo la mayoría exclusivas de cada finca ya que se encuentran adaptadas a las condiciones ambientales del lugar. M-

Photochemical solution processing of films of metastable phases for flexible devices: the beta-Bi2O3 polymorph

The potential of UV-light for the photochemical synthesis and stabilization of non-equilibrium crystalline phases in thin films is demonstrated for the beta-Bi2O3 polymorph. The pure beta-Bi2O3 phase is thermodynamically stable at high temperature (450-667 degrees C), which limits its applications in devices. Here, a tailored UV-absorbing bismuth(III)-N-methyldiethanolamine complex is selected as an ideal precursor for this phase, in order to induce under UV-light the formation of a -Bi-O-Bi- continuous network in the deposited layers and the further conversion into the beta-Bi2O3 polymorph at a temperature as low as 250 degrees C. The stabilization of the beta-Bi2O3 films is confirmed by their conductivity behavior and a thorough characterization of their crystal structure. This is also supported by their remarkable photocatalytic activity. Besides, this processing method has allowed us for the first time the preparation of beta-Bi2O3 films on flexible plastic substrates, which opens new opportunities for using these materials in potential applications not available until now (e.g., flexible photocatalytic reactors, self-cleaning surfaces or wearable antimicrobial fabrics). Therefore, photochemical solution deposition (PCSD) demonstrates to be not only an efficient approach for the low temperature processing of oxide films, but also an excellent alternative for the stabilization of metastable phases