651 research outputs found

    Sorption of lead (Pb2+) from aqueous solutions using chars obtained in the pyrolysis of forestry pine, rubber tires and plastics

    Get PDF
    Carbonaceous solid products resulting from thermochemical processes (pyrolysis, gasification), commonly known as chars, are emerging as low-cost sorbents of metallic contaminants, being their effectiveness already demonstrated in several studies (Inyang et al., 2012; Fuente-Cuesta et al., 2012; Ko³odyñska et al., 2012; Quek and Balasubramanian, 2009; Devecia and Kar, 2013). Given the fact that the commercial viability of pyrolysis and gasification plants for the treatment and valorisation of waste streams are increasingly being demonstrated, it is expected that large amounts of solid chars will be available in a near future, as by-products or as main products (pyrolysis-carbonization). Chars may possess several characteristics which turn them effective as heavy metals sorbents: aromatic carbon matrix with relatively porous structures, the presence of functional groups or inorganic inclusions in the surface providing active sites to interact with metallic species (Inyang et al., 2012; Fuente-Cuesta et al., 2012; Ko³odyñska et al., 2012; Quek and Balasubramanian, 2009; Devecia and Kar, 2013; Lu et al., 2012). Lead (Pb2+) is considered as a priority substance in the field of European water policy (EU, 2000; EU, 2008) which means that measures shall be taken by the Member States to eliminate or reduce the water pollution caused by this pollutant in order to fulfill the emission/discharge limits legislated for this compound

    Leaching behaviour and ecotoxicity evaluation of chars from the pyrolysis of forestry biomass and polymeric materials

    Get PDF
    The main objective of this study was to assess the environmental risk of chars derived from the pyrolysis of mixtures of pine, plastics, and scrap tires, by studying their leaching potential and ecotoxicity. Relationships between chemical composition and ecotoxicity were established to identify contaminants responsible for toxicity. Since metallic contaminants were the focus of the present study, an EDTA washing step was applied to the chars to selectively remove metals that can be responsible for the observed toxicity. The results indicated that the introduction of biomass to the pyrolysis feedstock enhanced the acidity of chars and promote the mobilisation of inorganic compounds. Chars resulting from the pyrolysis of blends of pine and plastics did not produce ecotoxic eluates. A relationship between zinc concentrations in eluates and their ecotoxicity was found for chars obtained from mixtures with tires. A significant reduction in ecotoxicity was found when the chars were treated with EDTA, which was due to a significant reduction in zinc in chars after EDTA washing

    Probable Person-to-Person Transmission of Legionnaires’ Disease

    Get PDF
    Correspondence to the Editor.Legionnaires’ disease is an often severe form of pneumonia that is typically acquired by susceptible persons (e.g., elderly persons and smokers) through inhalation of aerosols that contain legionella species.1-4 A cluster of cases of this disease occurred in Vila Franca de Xira, Portugal, in 2014

    Análise de Eventos de Vírgula do Buraco de Ozônio no Hemisfério sul e Interação com a Troposfera pelos Dados de Reanálise do ERA Interim

    Get PDF
    A formação do ozônio (O3) ocorre na baixa estratosfera, camada essa acima da troposfera, o mesmo possui uma grande concentração de energia, o que interfere no perfil de temperatura em praticamente toda estratosfera. A partir da década de 80, foram identificados valores muito baixos de ozônio estratosférico sobre o Continente Antártico, principalmente nos meses de setembro e outubro. Essa diminuição foi denominada de “buraco de ozônio Antártico”, que estava diretamente ligado a ação dos cloro-fluor-carbonetos (CFCs), que quebram as ligações de ozônio. Desta forma, este trabalho tem como finalidade estudar a presença desta anomalia na concentração de ozônio estratosférico, quando o “buraco” se estende até a América do Sul (AS) e possui um formato de “vírgula”, bem como sua implicação nas condições troposféricas. Utilizamos 38 anos de dados entre os meses de agosto e novembro, onde identificamos 122 eventos de baixo ozônio sobre o sul da América do Sul, sendo que, tais eventos apresentavam um formato de “vírgula” sobre a AS. A temperatura em 100 hPa (ainda dentro da troposfera) mostrou uma diminuição durante os eventos de “vírgula”, assim como os campos de vento zonal em 100 hPa. Observou-se através do vento zonal em 200 hPa que o Jato Subtropical sofre um enfraquecimento durante os eventos, que refletem em maiores amplitudes das ondas de Rossby. A vorticidade potencial apresenta um dipolo sobre o Atlântico, na região das quebras de onda de Rossby, levando a concluir que os eventos de vírgula tem relação direta com as trocas estratosfera-troposfera, pois ocorre a ruptura da tropopausa

    Narrative change in emotion-focused psychotherapy: a study on the evolution of reflection and protest innovative moments

    Get PDF
    Innovative moments (IMs) are exceptions to a client’s problematic self-narrative in the therapeutic dialogue. The innovative moments coding system is a tool which tracks five different types of IMs*action, reflection, protest, reconceptualization and performing change. An in-depth qualitative analysis of six therapeutic cases of emotion-focused therapy (EFT) investigated the role of two of the most common IMs*reflection and protest*in both good and poor outcome cases. Through this analysis two subtypes (I and II) of reflection and protest IMs were identified, revealing different evolution patterns. Subtype II of both reflection and protest IMs is significantly higher in the good outcome group, while subtype I of both IMs types does not present statistically significant differences between groups. The evolution from subtype I to subtype II across the therapeutic process seems to reflect a relevant developmental progression in the change process

    Reduction in hospitalised COPD exacerbations during COVID-19: A systematic review and meta-analysis

    Get PDF
    Coronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Malaltia pulmonar obstructiva crònica; Factors de risc mèdicsCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Enfermedad pulmonar obstructiva crónica; Factores de riesgo médicosCoronavirus SARS-CoV-2; COVID-19; 2019-nCoV; Chronic obstructive pulmonary disease; Medical risk factorsBackground Reports have suggested a reduction in exacerbations of chronic obstructive pulmonary disease (COPD) during the coronavirus disease 2019 (COVID-19) pandemic, particularly hospital admissions for severe exacerbations. However, the magnitude of this reduction varies between studies. Method Electronic databases were searched from January 2020 to May 2021. Two independent reviewers screened titles and abstracts and, when necessary, full text to determine if studies met inclusion criteria. A modified version of the Newcastle-Ottawa Scale was used to assess study quality. A narrative summary of eligible studies was synthesised, and meta-analysis was conducted using a random effect model to pool the rate ratio and 95% confidence intervals (95% CI) for hospital admissions. Exacerbation reduction was compared against the COVID-19 Containment and Health Index. Results A total of 13 of 745 studies met the inclusion criteria and were included in this review, with data from nine countries. Nine studies could be included in the meta-analysis. The pooled rate ratio of hospital admissions for COPD exacerbations during the pandemic period was 0.50 (95% CI 0.44–0.57). Findings on the rate of community-treated exacerbations were inconclusive. Three studies reported a significant decrease in the incidence of respiratory viral infections compared with the pre-pandemic period. There was not a significant relationship between exacerbation reduction and the COVID-19 Containment and Health Index (rho = 0.20, p = 0.53). Conclusion There was a 50% reduction in admissions for COPD exacerbations during the COVID-19 pandemic period compared to pre-pandemic times, likely associated with a reduction in respiratory viral infections that trigger exacerbations. Future guidelines should consider including recommendations on respiratory virus infection control measures to reduce the burden of COPD exacerbations beyond the pandemic period.The author(s) received no specific funding for this work

    Programa multidisciplinar de monitorização de curto termo para apoio ao planeamento e gestão da zona costeira

    Get PDF
    A zona costeira do noroeste de Portugal tem vindo a sofrer processos erosivos de modo progressivo que têm preocupado os responsáveis políticos e os cidadãos em geral. Esta realidade é especialmente notória nas zonas costeiras com altas pressões de ocupação. A zona costeira de Vila Nova de Gaia apresenta ocupação intensa, tendo vários segmentos que evidenciam elevada vulnerabilidade à erosão costeira. Com o objectivo de avaliar os segmentos mais vulneráveis foi implementado um programa global de monitorização iniciado em 2007. Pretende-se avaliar as tendências de evolução morfodinâmica do sistema costeiro, incluindo prépraia, praia e dunas. Este programa compreendeu a realização de duas campanhas anuais, durante dois anos, utilizando um conjunto de metodologias de monitorização inovadoras: observações de campo, fotografias aéreas, levantamentos topográficos com um sistema móvel com DGPS e câmaras de vídeo; levantamentos batimétricos utilizando uma embarcação autónoma flutuante; recolha de amostras de sedimentos e realização de perfis de praia. A informação produzida foi processada para utilização na avaliação da vulnerabilidade à erosão e produção das cartas de risco associadas, as quais estão em fase de elaboração. Todos os dados são processados e analisados em ambiente SIG. Neste artigo são apresentados resultados obtidos nas quatro campanhas de monitorização, incluindo aspectos da morfodinâmica local com base na análise dos Modelos Digitais de Terreno e as principais mudanças morfológicas e sedimentares verificadas no período de monitorização
    corecore